1 /* 2 * Copyright © 2009 Keith Packard 3 * 4 * Permission to use, copy, modify, distribute, and sell this software and its 5 * documentation for any purpose is hereby granted without fee, provided that 6 * the above copyright notice appear in all copies and that both that copyright 7 * notice and this permission notice appear in supporting documentation, and 8 * that the name of the copyright holders not be used in advertising or 9 * publicity pertaining to distribution of the software without specific, 10 * written prior permission. The copyright holders make no representations 11 * about the suitability of this software for any purpose. It is provided "as 12 * is" without express or implied warranty. 13 * 14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 20 * OF THIS SOFTWARE. 21 */ 22 23 #include <linux/backlight.h> 24 #include <linux/delay.h> 25 #include <linux/dynamic_debug.h> 26 #include <linux/errno.h> 27 #include <linux/export.h> 28 #include <linux/i2c.h> 29 #include <linux/init.h> 30 #include <linux/iopoll.h> 31 #include <linux/kernel.h> 32 #include <linux/minmax.h> 33 #include <linux/module.h> 34 #include <linux/sched.h> 35 #include <linux/seq_file.h> 36 #include <linux/string_helpers.h> 37 38 #include <drm/display/drm_dp_helper.h> 39 #include <drm/display/drm_dp_mst_helper.h> 40 #include <drm/drm_edid.h> 41 #include <drm/drm_fixed.h> 42 #include <drm/drm_print.h> 43 #include <drm/drm_vblank.h> 44 #include <drm/drm_panel.h> 45 46 #include "drm_dp_helper_internal.h" 47 48 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0, 49 "DRM_UT_CORE", 50 "DRM_UT_DRIVER", 51 "DRM_UT_KMS", 52 "DRM_UT_PRIME", 53 "DRM_UT_ATOMIC", 54 "DRM_UT_VBL", 55 "DRM_UT_STATE", 56 "DRM_UT_LEASE", 57 "DRM_UT_DP", 58 "DRM_UT_DRMRES"); 59 60 struct dp_aux_backlight { 61 struct backlight_device *base; 62 struct drm_dp_aux *aux; 63 struct drm_edp_backlight_info info; 64 bool enabled; 65 }; 66 67 /** 68 * DOC: dp helpers 69 * 70 * These functions contain some common logic and helpers at various abstraction 71 * levels to deal with Display Port sink devices and related things like DP aux 72 * channel transfers, EDID reading over DP aux channels, decoding certain DPCD 73 * blocks, ... 74 */ 75 76 /* Helpers for DP link training */ 77 static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) 78 { 79 return link_status[r - DP_LANE0_1_STATUS]; 80 } 81 82 static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], 83 int lane) 84 { 85 int i = DP_LANE0_1_STATUS + (lane >> 1); 86 int s = (lane & 1) * 4; 87 u8 l = dp_link_status(link_status, i); 88 89 return (l >> s) & 0xf; 90 } 91 92 bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], 93 int lane_count) 94 { 95 u8 lane_align; 96 u8 lane_status; 97 int lane; 98 99 lane_align = dp_link_status(link_status, 100 DP_LANE_ALIGN_STATUS_UPDATED); 101 if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) 102 return false; 103 for (lane = 0; lane < lane_count; lane++) { 104 lane_status = dp_get_lane_status(link_status, lane); 105 if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) 106 return false; 107 } 108 return true; 109 } 110 EXPORT_SYMBOL(drm_dp_channel_eq_ok); 111 112 bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], 113 int lane_count) 114 { 115 int lane; 116 u8 lane_status; 117 118 for (lane = 0; lane < lane_count; lane++) { 119 lane_status = dp_get_lane_status(link_status, lane); 120 if ((lane_status & DP_LANE_CR_DONE) == 0) 121 return false; 122 } 123 return true; 124 } 125 EXPORT_SYMBOL(drm_dp_clock_recovery_ok); 126 127 bool drm_dp_post_lt_adj_req_in_progress(const u8 link_status[DP_LINK_STATUS_SIZE]) 128 { 129 u8 lane_align = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 130 131 return lane_align & DP_POST_LT_ADJ_REQ_IN_PROGRESS; 132 } 133 EXPORT_SYMBOL(drm_dp_post_lt_adj_req_in_progress); 134 135 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], 136 int lane) 137 { 138 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); 139 int s = ((lane & 1) ? 140 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : 141 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); 142 u8 l = dp_link_status(link_status, i); 143 144 return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; 145 } 146 EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage); 147 148 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], 149 int lane) 150 { 151 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); 152 int s = ((lane & 1) ? 153 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : 154 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); 155 u8 l = dp_link_status(link_status, i); 156 157 return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; 158 } 159 EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); 160 161 /* DP 2.0 128b/132b */ 162 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE], 163 int lane) 164 { 165 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); 166 int s = ((lane & 1) ? 167 DP_ADJUST_TX_FFE_PRESET_LANE1_SHIFT : 168 DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT); 169 u8 l = dp_link_status(link_status, i); 170 171 return (l >> s) & 0xf; 172 } 173 EXPORT_SYMBOL(drm_dp_get_adjust_tx_ffe_preset); 174 175 /* DP 2.0 errata for 128b/132b */ 176 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE], 177 int lane_count) 178 { 179 u8 lane_align, lane_status; 180 int lane; 181 182 lane_align = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 183 if (!(lane_align & DP_INTERLANE_ALIGN_DONE)) 184 return false; 185 186 for (lane = 0; lane < lane_count; lane++) { 187 lane_status = dp_get_lane_status(link_status, lane); 188 if (!(lane_status & DP_LANE_CHANNEL_EQ_DONE)) 189 return false; 190 } 191 return true; 192 } 193 EXPORT_SYMBOL(drm_dp_128b132b_lane_channel_eq_done); 194 195 /* DP 2.0 errata for 128b/132b */ 196 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE], 197 int lane_count) 198 { 199 u8 lane_status; 200 int lane; 201 202 for (lane = 0; lane < lane_count; lane++) { 203 lane_status = dp_get_lane_status(link_status, lane); 204 if (!(lane_status & DP_LANE_SYMBOL_LOCKED)) 205 return false; 206 } 207 return true; 208 } 209 EXPORT_SYMBOL(drm_dp_128b132b_lane_symbol_locked); 210 211 /* DP 2.0 errata for 128b/132b */ 212 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]) 213 { 214 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 215 216 return status & DP_128B132B_DPRX_EQ_INTERLANE_ALIGN_DONE; 217 } 218 EXPORT_SYMBOL(drm_dp_128b132b_eq_interlane_align_done); 219 220 /* DP 2.0 errata for 128b/132b */ 221 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]) 222 { 223 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 224 225 return status & DP_128B132B_DPRX_CDS_INTERLANE_ALIGN_DONE; 226 } 227 EXPORT_SYMBOL(drm_dp_128b132b_cds_interlane_align_done); 228 229 /* DP 2.0 errata for 128b/132b */ 230 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]) 231 { 232 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 233 234 return status & DP_128B132B_LT_FAILED; 235 } 236 EXPORT_SYMBOL(drm_dp_128b132b_link_training_failed); 237 238 static int __8b10b_clock_recovery_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) 239 { 240 if (rd_interval > 4) 241 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", 242 aux->name, rd_interval); 243 244 if (rd_interval == 0) 245 return 100; 246 247 return rd_interval * 4 * USEC_PER_MSEC; 248 } 249 250 static int __8b10b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) 251 { 252 if (rd_interval > 4) 253 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", 254 aux->name, rd_interval); 255 256 if (rd_interval == 0) 257 return 400; 258 259 return rd_interval * 4 * USEC_PER_MSEC; 260 } 261 262 static int __128b132b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) 263 { 264 switch (rd_interval) { 265 default: 266 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x\n", 267 aux->name, rd_interval); 268 fallthrough; 269 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_400_US: 270 return 400; 271 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_4_MS: 272 return 4000; 273 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_8_MS: 274 return 8000; 275 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_12_MS: 276 return 12000; 277 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_16_MS: 278 return 16000; 279 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_32_MS: 280 return 32000; 281 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_64_MS: 282 return 64000; 283 } 284 } 285 286 /* 287 * The link training delays are different for: 288 * 289 * - Clock recovery vs. channel equalization 290 * - DPRX vs. LTTPR 291 * - 128b/132b vs. 8b/10b 292 * - DPCD rev 1.3 vs. later 293 * 294 * Get the correct delay in us, reading DPCD if necessary. 295 */ 296 static int __read_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 297 enum drm_dp_phy dp_phy, bool uhbr, bool cr) 298 { 299 int (*parse)(const struct drm_dp_aux *aux, u8 rd_interval); 300 unsigned int offset; 301 u8 rd_interval, mask; 302 303 if (dp_phy == DP_PHY_DPRX) { 304 if (uhbr) { 305 if (cr) 306 return 100; 307 308 offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL; 309 mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 310 parse = __128b132b_channel_eq_delay_us; 311 } else { 312 if (cr && dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) 313 return 100; 314 315 offset = DP_TRAINING_AUX_RD_INTERVAL; 316 mask = DP_TRAINING_AUX_RD_MASK; 317 if (cr) 318 parse = __8b10b_clock_recovery_delay_us; 319 else 320 parse = __8b10b_channel_eq_delay_us; 321 } 322 } else { 323 if (uhbr) { 324 offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); 325 mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 326 parse = __128b132b_channel_eq_delay_us; 327 } else { 328 if (cr) 329 return 100; 330 331 offset = DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); 332 mask = DP_TRAINING_AUX_RD_MASK; 333 parse = __8b10b_channel_eq_delay_us; 334 } 335 } 336 337 if (offset < DP_RECEIVER_CAP_SIZE) { 338 rd_interval = dpcd[offset]; 339 } else { 340 if (drm_dp_dpcd_read_byte(aux, offset, &rd_interval) < 0) { 341 drm_dbg_kms(aux->drm_dev, "%s: failed rd interval read\n", 342 aux->name); 343 /* arbitrary default delay */ 344 return 400; 345 } 346 } 347 348 return parse(aux, rd_interval & mask); 349 } 350 351 int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 352 enum drm_dp_phy dp_phy, bool uhbr) 353 { 354 return __read_delay(aux, dpcd, dp_phy, uhbr, true); 355 } 356 EXPORT_SYMBOL(drm_dp_read_clock_recovery_delay); 357 358 int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 359 enum drm_dp_phy dp_phy, bool uhbr) 360 { 361 return __read_delay(aux, dpcd, dp_phy, uhbr, false); 362 } 363 EXPORT_SYMBOL(drm_dp_read_channel_eq_delay); 364 365 /* Per DP 2.0 Errata */ 366 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux) 367 { 368 int unit; 369 u8 val; 370 371 if (drm_dp_dpcd_read_byte(aux, DP_128B132B_TRAINING_AUX_RD_INTERVAL, &val) < 0) { 372 drm_err(aux->drm_dev, "%s: failed rd interval read\n", 373 aux->name); 374 /* default to max */ 375 val = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 376 } 377 378 unit = (val & DP_128B132B_TRAINING_AUX_RD_INTERVAL_1MS_UNIT) ? 1 : 2; 379 val &= DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 380 381 return (val + 1) * unit * 1000; 382 } 383 EXPORT_SYMBOL(drm_dp_128b132b_read_aux_rd_interval); 384 385 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux, 386 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 387 { 388 u8 rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & 389 DP_TRAINING_AUX_RD_MASK; 390 int delay_us; 391 392 if (dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) 393 delay_us = 100; 394 else 395 delay_us = __8b10b_clock_recovery_delay_us(aux, rd_interval); 396 397 usleep_range(delay_us, delay_us * 2); 398 } 399 EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); 400 401 static void __drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 402 u8 rd_interval) 403 { 404 int delay_us = __8b10b_channel_eq_delay_us(aux, rd_interval); 405 406 usleep_range(delay_us, delay_us * 2); 407 } 408 409 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 410 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 411 { 412 __drm_dp_link_train_channel_eq_delay(aux, 413 dpcd[DP_TRAINING_AUX_RD_INTERVAL] & 414 DP_TRAINING_AUX_RD_MASK); 415 } 416 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); 417 418 /** 419 * drm_dp_phy_name() - Get the name of the given DP PHY 420 * @dp_phy: The DP PHY identifier 421 * 422 * Given the @dp_phy, get a user friendly name of the DP PHY, either "DPRX" or 423 * "LTTPR <N>", or "<INVALID DP PHY>" on errors. The returned string is always 424 * non-NULL and valid. 425 * 426 * Returns: Name of the DP PHY. 427 */ 428 const char *drm_dp_phy_name(enum drm_dp_phy dp_phy) 429 { 430 static const char * const phy_names[] = { 431 [DP_PHY_DPRX] = "DPRX", 432 [DP_PHY_LTTPR1] = "LTTPR 1", 433 [DP_PHY_LTTPR2] = "LTTPR 2", 434 [DP_PHY_LTTPR3] = "LTTPR 3", 435 [DP_PHY_LTTPR4] = "LTTPR 4", 436 [DP_PHY_LTTPR5] = "LTTPR 5", 437 [DP_PHY_LTTPR6] = "LTTPR 6", 438 [DP_PHY_LTTPR7] = "LTTPR 7", 439 [DP_PHY_LTTPR8] = "LTTPR 8", 440 }; 441 442 if (dp_phy < 0 || dp_phy >= ARRAY_SIZE(phy_names) || 443 WARN_ON(!phy_names[dp_phy])) 444 return "<INVALID DP PHY>"; 445 446 return phy_names[dp_phy]; 447 } 448 EXPORT_SYMBOL(drm_dp_phy_name); 449 450 void drm_dp_lttpr_link_train_clock_recovery_delay(void) 451 { 452 usleep_range(100, 200); 453 } 454 EXPORT_SYMBOL(drm_dp_lttpr_link_train_clock_recovery_delay); 455 456 static u8 dp_lttpr_phy_cap(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE], int r) 457 { 458 return phy_cap[r - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1]; 459 } 460 461 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 462 const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE]) 463 { 464 u8 interval = dp_lttpr_phy_cap(phy_cap, 465 DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) & 466 DP_TRAINING_AUX_RD_MASK; 467 468 __drm_dp_link_train_channel_eq_delay(aux, interval); 469 } 470 EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); 471 472 /** 473 * drm_dp_lttpr_wake_timeout_setup() - Grant extended time for sink to wake up 474 * @aux: The DP AUX channel to use 475 * @transparent_mode: This is true if lttpr is in transparent mode 476 * 477 * This function checks if the sink needs any extended wake time, if it does 478 * it grants this request. Post this setup the source device can keep trying 479 * the Aux transaction till the granted wake timeout. 480 * If this function is not called all Aux transactions are expected to take 481 * a default of 1ms before they throw an error. 482 */ 483 void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode) 484 { 485 u8 val = 1; 486 int ret; 487 488 if (transparent_mode) { 489 static const u8 timeout_mapping[] = { 490 [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_1_MS] = 1, 491 [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_20_MS] = 20, 492 [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_40_MS] = 40, 493 [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_60_MS] = 60, 494 [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_80_MS] = 80, 495 [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_100_MS] = 100, 496 }; 497 498 ret = drm_dp_dpcd_readb(aux, DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_REQUEST, &val); 499 if (ret != 1) { 500 drm_dbg_kms(aux->drm_dev, 501 "Failed to read Extended sleep wake timeout request\n"); 502 return; 503 } 504 505 val = (val < sizeof(timeout_mapping) && timeout_mapping[val]) ? 506 timeout_mapping[val] : 1; 507 508 if (val > 1) 509 drm_dp_dpcd_writeb(aux, 510 DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_GRANT, 511 DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_GRANTED); 512 } else { 513 ret = drm_dp_dpcd_readb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, &val); 514 if (ret != 1) { 515 drm_dbg_kms(aux->drm_dev, 516 "Failed to read Extended sleep wake timeout request\n"); 517 return; 518 } 519 520 val = (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) ? 521 (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) * 10 : 1; 522 523 if (val > 1) 524 drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, 525 DP_EXTENDED_WAKE_TIMEOUT_GRANT); 526 } 527 } 528 EXPORT_SYMBOL(drm_dp_lttpr_wake_timeout_setup); 529 530 u8 drm_dp_link_rate_to_bw_code(int link_rate) 531 { 532 switch (link_rate) { 533 case 1000000: 534 return DP_LINK_BW_10; 535 case 1350000: 536 return DP_LINK_BW_13_5; 537 case 2000000: 538 return DP_LINK_BW_20; 539 default: 540 /* Spec says link_bw = link_rate / 0.27Gbps */ 541 return link_rate / 27000; 542 } 543 } 544 EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); 545 546 int drm_dp_bw_code_to_link_rate(u8 link_bw) 547 { 548 switch (link_bw) { 549 case DP_LINK_BW_10: 550 return 1000000; 551 case DP_LINK_BW_13_5: 552 return 1350000; 553 case DP_LINK_BW_20: 554 return 2000000; 555 default: 556 /* Spec says link_rate = link_bw * 0.27Gbps */ 557 return link_bw * 27000; 558 } 559 } 560 EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); 561 562 #define AUX_RETRY_INTERVAL 500 /* us */ 563 564 static inline void 565 drm_dp_dump_access(const struct drm_dp_aux *aux, 566 u8 request, uint offset, void *buffer, int ret) 567 { 568 const char *arrow = request == DP_AUX_NATIVE_READ ? "->" : "<-"; 569 570 if (ret > 0) 571 drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d) %*ph\n", 572 aux->name, offset, arrow, ret, min(ret, 20), buffer); 573 else 574 drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d)\n", 575 aux->name, offset, arrow, ret); 576 } 577 578 /** 579 * DOC: dp helpers 580 * 581 * The DisplayPort AUX channel is an abstraction to allow generic, driver- 582 * independent access to AUX functionality. Drivers can take advantage of 583 * this by filling in the fields of the drm_dp_aux structure. 584 * 585 * Transactions are described using a hardware-independent drm_dp_aux_msg 586 * structure, which is passed into a driver's .transfer() implementation. 587 * Both native and I2C-over-AUX transactions are supported. 588 */ 589 590 static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, 591 unsigned int offset, void *buffer, size_t size) 592 { 593 struct drm_dp_aux_msg msg; 594 unsigned int retry, native_reply; 595 int err = 0, ret = 0; 596 597 memset(&msg, 0, sizeof(msg)); 598 msg.address = offset; 599 msg.request = request; 600 msg.buffer = buffer; 601 msg.size = size; 602 603 mutex_lock(&aux->hw_mutex); 604 605 /* 606 * If the device attached to the aux bus is powered down then there's 607 * no reason to attempt a transfer. Error out immediately. 608 */ 609 if (aux->powered_down) { 610 ret = -EBUSY; 611 goto unlock; 612 } 613 614 /* 615 * The specification doesn't give any recommendation on how often to 616 * retry native transactions. We used to retry 7 times like for 617 * aux i2c transactions but real world devices this wasn't 618 * sufficient, bump to 32 which makes Dell 4k monitors happier. 619 */ 620 for (retry = 0; retry < 32; retry++) { 621 if (ret != 0 && ret != -ETIMEDOUT) { 622 usleep_range(AUX_RETRY_INTERVAL, 623 AUX_RETRY_INTERVAL + 100); 624 } 625 626 ret = aux->transfer(aux, &msg); 627 if (ret >= 0) { 628 native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK; 629 if (native_reply == DP_AUX_NATIVE_REPLY_ACK) { 630 if (ret == size) 631 goto unlock; 632 633 ret = -EPROTO; 634 } else 635 ret = -EIO; 636 } 637 638 /* 639 * We want the error we return to be the error we received on 640 * the first transaction, since we may get a different error the 641 * next time we retry 642 */ 643 if (!err) 644 err = ret; 645 } 646 647 drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up. First error: %d\n", 648 aux->name, err); 649 ret = err; 650 651 unlock: 652 mutex_unlock(&aux->hw_mutex); 653 return ret; 654 } 655 656 /** 657 * drm_dp_dpcd_probe() - probe a given DPCD address with a 1-byte read access 658 * @aux: DisplayPort AUX channel (SST) 659 * @offset: address of the register to probe 660 * 661 * Probe the provided DPCD address by reading 1 byte from it. The function can 662 * be used to trigger some side-effect the read access has, like waking up the 663 * sink, without the need for the read-out value. 664 * 665 * Returns 0 if the read access suceeded, or a negative error code on failure. 666 */ 667 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset) 668 { 669 u8 buffer; 670 int ret; 671 672 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, 1); 673 WARN_ON(ret == 0); 674 675 drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, ret); 676 677 return ret < 0 ? ret : 0; 678 } 679 EXPORT_SYMBOL(drm_dp_dpcd_probe); 680 681 /** 682 * drm_dp_dpcd_set_powered() - Set whether the DP device is powered 683 * @aux: DisplayPort AUX channel; for convenience it's OK to pass NULL here 684 * and the function will be a no-op. 685 * @powered: true if powered; false if not 686 * 687 * If the endpoint device on the DP AUX bus is known to be powered down 688 * then this function can be called to make future transfers fail immediately 689 * instead of needing to time out. 690 * 691 * If this function is never called then a device defaults to being powered. 692 */ 693 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered) 694 { 695 if (!aux) 696 return; 697 698 mutex_lock(&aux->hw_mutex); 699 aux->powered_down = !powered; 700 mutex_unlock(&aux->hw_mutex); 701 } 702 EXPORT_SYMBOL(drm_dp_dpcd_set_powered); 703 704 /** 705 * drm_dp_dpcd_set_probe() - Set whether a probing before DPCD access is done 706 * @aux: DisplayPort AUX channel 707 * @enable: Enable the probing if required 708 */ 709 void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable) 710 { 711 WRITE_ONCE(aux->dpcd_probe_disabled, !enable); 712 } 713 EXPORT_SYMBOL(drm_dp_dpcd_set_probe); 714 715 static bool dpcd_access_needs_probe(struct drm_dp_aux *aux) 716 { 717 /* 718 * HP ZR24w corrupts the first DPCD access after entering power save 719 * mode. Eg. on a read, the entire buffer will be filled with the same 720 * byte. Do a throw away read to avoid corrupting anything we care 721 * about. Afterwards things will work correctly until the monitor 722 * gets woken up and subsequently re-enters power save mode. 723 * 724 * The user pressing any button on the monitor is enough to wake it 725 * up, so there is no particularly good place to do the workaround. 726 * We just have to do it before any DPCD access and hope that the 727 * monitor doesn't power down exactly after the throw away read. 728 */ 729 return !aux->is_remote && !READ_ONCE(aux->dpcd_probe_disabled); 730 } 731 732 /** 733 * drm_dp_dpcd_read() - read a series of bytes from the DPCD 734 * @aux: DisplayPort AUX channel (SST or MST) 735 * @offset: address of the (first) register to read 736 * @buffer: buffer to store the register values 737 * @size: number of bytes in @buffer 738 * 739 * Returns the number of bytes transferred on success, or a negative error 740 * code on failure. -EIO is returned if the request was NAKed by the sink or 741 * if the retry count was exceeded. If not all bytes were transferred, this 742 * function returns -EPROTO. Errors from the underlying AUX channel transfer 743 * function, with the exception of -EBUSY (which causes the transaction to 744 * be retried), are propagated to the caller. 745 * 746 * In most of the cases you want to use drm_dp_dpcd_read_data() instead. 747 */ 748 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, 749 void *buffer, size_t size) 750 { 751 int ret; 752 753 if (dpcd_access_needs_probe(aux)) { 754 ret = drm_dp_dpcd_probe(aux, DP_TRAINING_PATTERN_SET); 755 if (ret < 0) 756 return ret; 757 } 758 759 if (aux->is_remote) 760 ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size); 761 else 762 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, 763 buffer, size); 764 765 drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret); 766 return ret; 767 } 768 EXPORT_SYMBOL(drm_dp_dpcd_read); 769 770 /** 771 * drm_dp_dpcd_write() - write a series of bytes to the DPCD 772 * @aux: DisplayPort AUX channel (SST or MST) 773 * @offset: address of the (first) register to write 774 * @buffer: buffer containing the values to write 775 * @size: number of bytes in @buffer 776 * 777 * Returns the number of bytes transferred on success, or a negative error 778 * code on failure. -EIO is returned if the request was NAKed by the sink or 779 * if the retry count was exceeded. If not all bytes were transferred, this 780 * function returns -EPROTO. Errors from the underlying AUX channel transfer 781 * function, with the exception of -EBUSY (which causes the transaction to 782 * be retried), are propagated to the caller. 783 * 784 * In most of the cases you want to use drm_dp_dpcd_write_data() instead. 785 */ 786 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, 787 void *buffer, size_t size) 788 { 789 int ret; 790 791 if (aux->is_remote) 792 ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size); 793 else 794 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, 795 buffer, size); 796 797 drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret); 798 return ret; 799 } 800 EXPORT_SYMBOL(drm_dp_dpcd_write); 801 802 /** 803 * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) 804 * @aux: DisplayPort AUX channel 805 * @status: buffer to store the link status in (must be at least 6 bytes) 806 * 807 * Returns a negative error code on failure or 0 on success. 808 */ 809 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, 810 u8 status[DP_LINK_STATUS_SIZE]) 811 { 812 return drm_dp_dpcd_read_data(aux, DP_LANE0_1_STATUS, status, 813 DP_LINK_STATUS_SIZE); 814 } 815 EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); 816 817 /** 818 * drm_dp_dpcd_read_phy_link_status - get the link status information for a DP PHY 819 * @aux: DisplayPort AUX channel 820 * @dp_phy: the DP PHY to get the link status for 821 * @link_status: buffer to return the status in 822 * 823 * Fetch the AUX DPCD registers for the DPRX or an LTTPR PHY link status. The 824 * layout of the returned @link_status matches the DPCD register layout of the 825 * DPRX PHY link status. 826 * 827 * Returns 0 if the information was read successfully or a negative error code 828 * on failure. 829 */ 830 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, 831 enum drm_dp_phy dp_phy, 832 u8 link_status[DP_LINK_STATUS_SIZE]) 833 { 834 int ret; 835 836 if (dp_phy == DP_PHY_DPRX) 837 return drm_dp_dpcd_read_data(aux, 838 DP_LANE0_1_STATUS, 839 link_status, 840 DP_LINK_STATUS_SIZE); 841 842 ret = drm_dp_dpcd_read_data(aux, 843 DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy), 844 link_status, 845 DP_LINK_STATUS_SIZE - 1); 846 847 if (ret < 0) 848 return ret; 849 850 /* Convert the LTTPR to the sink PHY link status layout */ 851 memmove(&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS + 1], 852 &link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS], 853 DP_LINK_STATUS_SIZE - (DP_SINK_STATUS - DP_LANE0_1_STATUS) - 1); 854 link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS] = 0; 855 856 return 0; 857 } 858 EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); 859 860 /** 861 * drm_dp_link_power_up() - power up a DisplayPort link 862 * @aux: DisplayPort AUX channel 863 * @revision: DPCD revision supported on the link 864 * 865 * Returns 0 on success or a negative error code on failure. 866 */ 867 int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision) 868 { 869 u8 value; 870 int err; 871 872 /* DP_SET_POWER register is only available on DPCD v1.1 and later */ 873 if (revision < DP_DPCD_REV_11) 874 return 0; 875 876 err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); 877 if (err < 0) 878 return err; 879 880 value &= ~DP_SET_POWER_MASK; 881 value |= DP_SET_POWER_D0; 882 883 err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); 884 if (err < 0) 885 return err; 886 887 /* 888 * According to the DP 1.1 specification, a "Sink Device must exit the 889 * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink 890 * Control Field" (register 0x600). 891 */ 892 usleep_range(1000, 2000); 893 894 return 0; 895 } 896 EXPORT_SYMBOL(drm_dp_link_power_up); 897 898 /** 899 * drm_dp_link_power_down() - power down a DisplayPort link 900 * @aux: DisplayPort AUX channel 901 * @revision: DPCD revision supported on the link 902 * 903 * Returns 0 on success or a negative error code on failure. 904 */ 905 int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision) 906 { 907 u8 value; 908 int err; 909 910 /* DP_SET_POWER register is only available on DPCD v1.1 and later */ 911 if (revision < DP_DPCD_REV_11) 912 return 0; 913 914 err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); 915 if (err < 0) 916 return err; 917 918 value &= ~DP_SET_POWER_MASK; 919 value |= DP_SET_POWER_D3; 920 921 err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); 922 if (err < 0) 923 return err; 924 925 return 0; 926 } 927 EXPORT_SYMBOL(drm_dp_link_power_down); 928 929 static int read_payload_update_status(struct drm_dp_aux *aux) 930 { 931 int ret; 932 u8 status; 933 934 ret = drm_dp_dpcd_read_byte(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 935 if (ret < 0) 936 return ret; 937 938 return status; 939 } 940 941 /** 942 * drm_dp_dpcd_write_payload() - Write Virtual Channel information to payload table 943 * @aux: DisplayPort AUX channel 944 * @vcpid: Virtual Channel Payload ID 945 * @start_time_slot: Starting time slot 946 * @time_slot_count: Time slot count 947 * 948 * Write the Virtual Channel payload allocation table, checking the payload 949 * update status and retrying as necessary. 950 * 951 * Returns: 952 * 0 on success, negative error otherwise 953 */ 954 int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux, 955 int vcpid, u8 start_time_slot, u8 time_slot_count) 956 { 957 u8 payload_alloc[3], status; 958 int ret; 959 int retries = 0; 960 961 drm_dp_dpcd_write_byte(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 962 DP_PAYLOAD_TABLE_UPDATED); 963 964 payload_alloc[0] = vcpid; 965 payload_alloc[1] = start_time_slot; 966 payload_alloc[2] = time_slot_count; 967 968 ret = drm_dp_dpcd_write_data(aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 969 if (ret < 0) { 970 drm_dbg_kms(aux->drm_dev, "failed to write payload allocation %d\n", ret); 971 goto fail; 972 } 973 974 retry: 975 ret = drm_dp_dpcd_read_byte(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 976 if (ret < 0) { 977 drm_dbg_kms(aux->drm_dev, "failed to read payload table status %d\n", ret); 978 goto fail; 979 } 980 981 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 982 retries++; 983 if (retries < 20) { 984 usleep_range(10000, 20000); 985 goto retry; 986 } 987 drm_dbg_kms(aux->drm_dev, "status not set after read payload table status %d\n", 988 status); 989 ret = -EINVAL; 990 goto fail; 991 } 992 ret = 0; 993 fail: 994 return ret; 995 } 996 EXPORT_SYMBOL(drm_dp_dpcd_write_payload); 997 998 /** 999 * drm_dp_dpcd_clear_payload() - Clear the entire VC Payload ID table 1000 * @aux: DisplayPort AUX channel 1001 * 1002 * Clear the entire VC Payload ID table. 1003 * 1004 * Returns: 0 on success, negative error code on errors. 1005 */ 1006 int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux) 1007 { 1008 return drm_dp_dpcd_write_payload(aux, 0, 0, 0x3f); 1009 } 1010 EXPORT_SYMBOL(drm_dp_dpcd_clear_payload); 1011 1012 /** 1013 * drm_dp_dpcd_poll_act_handled() - Poll for ACT handled status 1014 * @aux: DisplayPort AUX channel 1015 * @timeout_ms: Timeout in ms 1016 * 1017 * Try waiting for the sink to finish updating its payload table by polling for 1018 * the ACT handled bit of DP_PAYLOAD_TABLE_UPDATE_STATUS for up to @timeout_ms 1019 * milliseconds, defaulting to 3000 ms if 0. 1020 * 1021 * Returns: 1022 * 0 if the ACT was handled in time, negative error code on failure. 1023 */ 1024 int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms) 1025 { 1026 int ret, status; 1027 1028 /* default to 3 seconds, this is arbitrary */ 1029 timeout_ms = timeout_ms ?: 3000; 1030 1031 ret = readx_poll_timeout(read_payload_update_status, aux, status, 1032 status & DP_PAYLOAD_ACT_HANDLED || status < 0, 1033 200, timeout_ms * USEC_PER_MSEC); 1034 if (ret < 0 && status >= 0) { 1035 drm_err(aux->drm_dev, "Failed to get ACT after %d ms, last status: %02x\n", 1036 timeout_ms, status); 1037 return -EINVAL; 1038 } else if (status < 0) { 1039 /* 1040 * Failure here isn't unexpected - the hub may have 1041 * just been unplugged 1042 */ 1043 drm_dbg_kms(aux->drm_dev, "Failed to read payload table status: %d\n", status); 1044 return status; 1045 } 1046 1047 return 0; 1048 } 1049 EXPORT_SYMBOL(drm_dp_dpcd_poll_act_handled); 1050 1051 static bool is_edid_digital_input_dp(const struct drm_edid *drm_edid) 1052 { 1053 /* FIXME: get rid of drm_edid_raw() */ 1054 const struct edid *edid = drm_edid_raw(drm_edid); 1055 1056 return edid && edid->revision >= 4 && 1057 edid->input & DRM_EDID_INPUT_DIGITAL && 1058 (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP; 1059 } 1060 1061 /** 1062 * drm_dp_downstream_is_type() - is the downstream facing port of certain type? 1063 * @dpcd: DisplayPort configuration data 1064 * @port_cap: port capabilities 1065 * @type: port type to be checked. Can be: 1066 * %DP_DS_PORT_TYPE_DP, %DP_DS_PORT_TYPE_VGA, %DP_DS_PORT_TYPE_DVI, 1067 * %DP_DS_PORT_TYPE_HDMI, %DP_DS_PORT_TYPE_NON_EDID, 1068 * %DP_DS_PORT_TYPE_DP_DUALMODE or %DP_DS_PORT_TYPE_WIRELESS. 1069 * 1070 * Caveat: Only works with DPCD 1.1+ port caps. 1071 * 1072 * Returns: whether the downstream facing port matches the type. 1073 */ 1074 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1075 const u8 port_cap[4], u8 type) 1076 { 1077 return drm_dp_is_branch(dpcd) && 1078 dpcd[DP_DPCD_REV] >= 0x11 && 1079 (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type; 1080 } 1081 EXPORT_SYMBOL(drm_dp_downstream_is_type); 1082 1083 /** 1084 * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS? 1085 * @dpcd: DisplayPort configuration data 1086 * @port_cap: port capabilities 1087 * @drm_edid: EDID 1088 * 1089 * Returns: whether the downstream facing port is TMDS (HDMI/DVI). 1090 */ 1091 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1092 const u8 port_cap[4], 1093 const struct drm_edid *drm_edid) 1094 { 1095 if (dpcd[DP_DPCD_REV] < 0x11) { 1096 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1097 case DP_DWN_STRM_PORT_TYPE_TMDS: 1098 return true; 1099 default: 1100 return false; 1101 } 1102 } 1103 1104 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1105 case DP_DS_PORT_TYPE_DP_DUALMODE: 1106 if (is_edid_digital_input_dp(drm_edid)) 1107 return false; 1108 fallthrough; 1109 case DP_DS_PORT_TYPE_DVI: 1110 case DP_DS_PORT_TYPE_HDMI: 1111 return true; 1112 default: 1113 return false; 1114 } 1115 } 1116 EXPORT_SYMBOL(drm_dp_downstream_is_tmds); 1117 1118 /** 1119 * drm_dp_send_real_edid_checksum() - send back real edid checksum value 1120 * @aux: DisplayPort AUX channel 1121 * @real_edid_checksum: real edid checksum for the last block 1122 * 1123 * Returns: 1124 * True on success 1125 */ 1126 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, 1127 u8 real_edid_checksum) 1128 { 1129 u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0; 1130 1131 if (drm_dp_dpcd_read_byte(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, 1132 &auto_test_req) < 0) { 1133 drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n", 1134 aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); 1135 return false; 1136 } 1137 auto_test_req &= DP_AUTOMATED_TEST_REQUEST; 1138 1139 if (drm_dp_dpcd_read_byte(aux, DP_TEST_REQUEST, &link_edid_read) < 0) { 1140 drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n", 1141 aux->name, DP_TEST_REQUEST); 1142 return false; 1143 } 1144 link_edid_read &= DP_TEST_LINK_EDID_READ; 1145 1146 if (!auto_test_req || !link_edid_read) { 1147 drm_dbg_kms(aux->drm_dev, "%s: Source DUT does not support TEST_EDID_READ\n", 1148 aux->name); 1149 return false; 1150 } 1151 1152 if (drm_dp_dpcd_write_byte(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, 1153 auto_test_req) < 0) { 1154 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", 1155 aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); 1156 return false; 1157 } 1158 1159 /* send back checksum for the last edid extension block data */ 1160 if (drm_dp_dpcd_write_byte(aux, DP_TEST_EDID_CHECKSUM, 1161 real_edid_checksum) < 0) { 1162 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", 1163 aux->name, DP_TEST_EDID_CHECKSUM); 1164 return false; 1165 } 1166 1167 test_resp |= DP_TEST_EDID_CHECKSUM_WRITE; 1168 if (drm_dp_dpcd_write_byte(aux, DP_TEST_RESPONSE, test_resp) < 0) { 1169 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", 1170 aux->name, DP_TEST_RESPONSE); 1171 return false; 1172 } 1173 1174 return true; 1175 } 1176 EXPORT_SYMBOL(drm_dp_send_real_edid_checksum); 1177 1178 static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 1179 { 1180 u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK; 1181 1182 if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4) 1183 port_count = 4; 1184 1185 return port_count; 1186 } 1187 1188 static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, 1189 u8 dpcd[DP_RECEIVER_CAP_SIZE]) 1190 { 1191 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 1192 int ret; 1193 1194 /* 1195 * Prior to DP1.3 the bit represented by 1196 * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. 1197 * If it is set DP_DPCD_REV at 0000h could be at a value less than 1198 * the true capability of the panel. The only way to check is to 1199 * then compare 0000h and 2200h. 1200 */ 1201 if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & 1202 DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) 1203 return 0; 1204 1205 ret = drm_dp_dpcd_read_data(aux, DP_DP13_DPCD_REV, &dpcd_ext, 1206 sizeof(dpcd_ext)); 1207 if (ret < 0) 1208 return ret; 1209 1210 if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { 1211 drm_dbg_kms(aux->drm_dev, 1212 "%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n", 1213 aux->name, dpcd[DP_DPCD_REV], dpcd_ext[DP_DPCD_REV]); 1214 return 0; 1215 } 1216 1217 if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext))) 1218 return 0; 1219 1220 drm_dbg_kms(aux->drm_dev, "%s: Base DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd); 1221 1222 memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext)); 1223 1224 return 0; 1225 } 1226 1227 /** 1228 * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if 1229 * available 1230 * @aux: DisplayPort AUX channel 1231 * @dpcd: Buffer to store the resulting DPCD in 1232 * 1233 * Attempts to read the base DPCD caps for @aux. Additionally, this function 1234 * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if 1235 * present. 1236 * 1237 * Returns: %0 if the DPCD was read successfully, negative error code 1238 * otherwise. 1239 */ 1240 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, 1241 u8 dpcd[DP_RECEIVER_CAP_SIZE]) 1242 { 1243 int ret; 1244 1245 ret = drm_dp_dpcd_read_data(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); 1246 if (ret < 0) 1247 return ret; 1248 if (dpcd[DP_DPCD_REV] == 0) 1249 return -EIO; 1250 1251 ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); 1252 if (ret < 0) 1253 return ret; 1254 1255 drm_dbg_kms(aux->drm_dev, "%s: DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd); 1256 1257 return ret; 1258 } 1259 EXPORT_SYMBOL(drm_dp_read_dpcd_caps); 1260 1261 /** 1262 * drm_dp_read_downstream_info() - read DPCD downstream port info if available 1263 * @aux: DisplayPort AUX channel 1264 * @dpcd: A cached copy of the port's DPCD 1265 * @downstream_ports: buffer to store the downstream port info in 1266 * 1267 * See also: 1268 * drm_dp_downstream_max_clock() 1269 * drm_dp_downstream_max_bpc() 1270 * 1271 * Returns: 0 if either the downstream port info was read successfully or 1272 * there was no downstream info to read, or a negative error code otherwise. 1273 */ 1274 int drm_dp_read_downstream_info(struct drm_dp_aux *aux, 1275 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1276 u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]) 1277 { 1278 int ret; 1279 u8 len; 1280 1281 memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS); 1282 1283 /* No downstream info to read */ 1284 if (!drm_dp_is_branch(dpcd) || dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) 1285 return 0; 1286 1287 /* Some branches advertise having 0 downstream ports, despite also advertising they have a 1288 * downstream port present. The DP spec isn't clear on if this is allowed or not, but since 1289 * some branches do it we need to handle it regardless. 1290 */ 1291 len = drm_dp_downstream_port_count(dpcd); 1292 if (!len) 1293 return 0; 1294 1295 if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) 1296 len *= 4; 1297 1298 ret = drm_dp_dpcd_read_data(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); 1299 if (ret < 0) 1300 return ret; 1301 1302 drm_dbg_kms(aux->drm_dev, "%s: DPCD DFP: %*ph\n", aux->name, len, downstream_ports); 1303 1304 return 0; 1305 } 1306 EXPORT_SYMBOL(drm_dp_read_downstream_info); 1307 1308 /** 1309 * drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock 1310 * @dpcd: DisplayPort configuration data 1311 * @port_cap: port capabilities 1312 * 1313 * Returns: Downstream facing port max dot clock in kHz on success, 1314 * or 0 if max clock not defined 1315 */ 1316 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1317 const u8 port_cap[4]) 1318 { 1319 if (!drm_dp_is_branch(dpcd)) 1320 return 0; 1321 1322 if (dpcd[DP_DPCD_REV] < 0x11) 1323 return 0; 1324 1325 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1326 case DP_DS_PORT_TYPE_VGA: 1327 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1328 return 0; 1329 return port_cap[1] * 8000; 1330 default: 1331 return 0; 1332 } 1333 } 1334 EXPORT_SYMBOL(drm_dp_downstream_max_dotclock); 1335 1336 /** 1337 * drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock 1338 * @dpcd: DisplayPort configuration data 1339 * @port_cap: port capabilities 1340 * @drm_edid: EDID 1341 * 1342 * Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success, 1343 * or 0 if max TMDS clock not defined 1344 */ 1345 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1346 const u8 port_cap[4], 1347 const struct drm_edid *drm_edid) 1348 { 1349 if (!drm_dp_is_branch(dpcd)) 1350 return 0; 1351 1352 if (dpcd[DP_DPCD_REV] < 0x11) { 1353 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1354 case DP_DWN_STRM_PORT_TYPE_TMDS: 1355 return 165000; 1356 default: 1357 return 0; 1358 } 1359 } 1360 1361 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1362 case DP_DS_PORT_TYPE_DP_DUALMODE: 1363 if (is_edid_digital_input_dp(drm_edid)) 1364 return 0; 1365 /* 1366 * It's left up to the driver to check the 1367 * DP dual mode adapter's max TMDS clock. 1368 * 1369 * Unfortunately it looks like branch devices 1370 * may not fordward that the DP dual mode i2c 1371 * access so we just usually get i2c nak :( 1372 */ 1373 fallthrough; 1374 case DP_DS_PORT_TYPE_HDMI: 1375 /* 1376 * We should perhaps assume 165 MHz when detailed cap 1377 * info is not available. But looks like many typical 1378 * branch devices fall into that category and so we'd 1379 * probably end up with users complaining that they can't 1380 * get high resolution modes with their favorite dongle. 1381 * 1382 * So let's limit to 300 MHz instead since DPCD 1.4 1383 * HDMI 2.0 DFPs are required to have the detailed cap 1384 * info. So it's more likely we're dealing with a HDMI 1.4 1385 * compatible* device here. 1386 */ 1387 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1388 return 300000; 1389 return port_cap[1] * 2500; 1390 case DP_DS_PORT_TYPE_DVI: 1391 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1392 return 165000; 1393 /* FIXME what to do about DVI dual link? */ 1394 return port_cap[1] * 2500; 1395 default: 1396 return 0; 1397 } 1398 } 1399 EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock); 1400 1401 /** 1402 * drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock 1403 * @dpcd: DisplayPort configuration data 1404 * @port_cap: port capabilities 1405 * @drm_edid: EDID 1406 * 1407 * Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success, 1408 * or 0 if max TMDS clock not defined 1409 */ 1410 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1411 const u8 port_cap[4], 1412 const struct drm_edid *drm_edid) 1413 { 1414 if (!drm_dp_is_branch(dpcd)) 1415 return 0; 1416 1417 if (dpcd[DP_DPCD_REV] < 0x11) { 1418 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1419 case DP_DWN_STRM_PORT_TYPE_TMDS: 1420 return 25000; 1421 default: 1422 return 0; 1423 } 1424 } 1425 1426 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1427 case DP_DS_PORT_TYPE_DP_DUALMODE: 1428 if (is_edid_digital_input_dp(drm_edid)) 1429 return 0; 1430 fallthrough; 1431 case DP_DS_PORT_TYPE_DVI: 1432 case DP_DS_PORT_TYPE_HDMI: 1433 /* 1434 * Unclear whether the protocol converter could 1435 * utilize pixel replication. Assume it won't. 1436 */ 1437 return 25000; 1438 default: 1439 return 0; 1440 } 1441 } 1442 EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock); 1443 1444 /** 1445 * drm_dp_downstream_max_bpc() - extract downstream facing port max 1446 * bits per component 1447 * @dpcd: DisplayPort configuration data 1448 * @port_cap: downstream facing port capabilities 1449 * @drm_edid: EDID 1450 * 1451 * Returns: Max bpc on success or 0 if max bpc not defined 1452 */ 1453 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1454 const u8 port_cap[4], 1455 const struct drm_edid *drm_edid) 1456 { 1457 if (!drm_dp_is_branch(dpcd)) 1458 return 0; 1459 1460 if (dpcd[DP_DPCD_REV] < 0x11) { 1461 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1462 case DP_DWN_STRM_PORT_TYPE_DP: 1463 return 0; 1464 default: 1465 return 8; 1466 } 1467 } 1468 1469 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1470 case DP_DS_PORT_TYPE_DP: 1471 return 0; 1472 case DP_DS_PORT_TYPE_DP_DUALMODE: 1473 if (is_edid_digital_input_dp(drm_edid)) 1474 return 0; 1475 fallthrough; 1476 case DP_DS_PORT_TYPE_HDMI: 1477 case DP_DS_PORT_TYPE_DVI: 1478 case DP_DS_PORT_TYPE_VGA: 1479 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1480 return 8; 1481 1482 switch (port_cap[2] & DP_DS_MAX_BPC_MASK) { 1483 case DP_DS_8BPC: 1484 return 8; 1485 case DP_DS_10BPC: 1486 return 10; 1487 case DP_DS_12BPC: 1488 return 12; 1489 case DP_DS_16BPC: 1490 return 16; 1491 default: 1492 return 8; 1493 } 1494 break; 1495 default: 1496 return 8; 1497 } 1498 } 1499 EXPORT_SYMBOL(drm_dp_downstream_max_bpc); 1500 1501 /** 1502 * drm_dp_downstream_420_passthrough() - determine downstream facing port 1503 * YCbCr 4:2:0 pass-through capability 1504 * @dpcd: DisplayPort configuration data 1505 * @port_cap: downstream facing port capabilities 1506 * 1507 * Returns: whether the downstream facing port can pass through YCbCr 4:2:0 1508 */ 1509 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1510 const u8 port_cap[4]) 1511 { 1512 if (!drm_dp_is_branch(dpcd)) 1513 return false; 1514 1515 if (dpcd[DP_DPCD_REV] < 0x13) 1516 return false; 1517 1518 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1519 case DP_DS_PORT_TYPE_DP: 1520 return true; 1521 case DP_DS_PORT_TYPE_HDMI: 1522 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1523 return false; 1524 1525 return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH; 1526 default: 1527 return false; 1528 } 1529 } 1530 EXPORT_SYMBOL(drm_dp_downstream_420_passthrough); 1531 1532 /** 1533 * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port 1534 * YCbCr 4:4:4->4:2:0 conversion capability 1535 * @dpcd: DisplayPort configuration data 1536 * @port_cap: downstream facing port capabilities 1537 * 1538 * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0 1539 */ 1540 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1541 const u8 port_cap[4]) 1542 { 1543 if (!drm_dp_is_branch(dpcd)) 1544 return false; 1545 1546 if (dpcd[DP_DPCD_REV] < 0x13) 1547 return false; 1548 1549 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1550 case DP_DS_PORT_TYPE_HDMI: 1551 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1552 return false; 1553 1554 return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV; 1555 default: 1556 return false; 1557 } 1558 } 1559 EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); 1560 1561 /** 1562 * drm_dp_downstream_rgb_to_ycbcr_conversion() - determine downstream facing port 1563 * RGB->YCbCr conversion capability 1564 * @dpcd: DisplayPort configuration data 1565 * @port_cap: downstream facing port capabilities 1566 * @color_spc: Colorspace for which conversion cap is sought 1567 * 1568 * Returns: whether the downstream facing port can convert RGB->YCbCr for a given 1569 * colorspace. 1570 */ 1571 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1572 const u8 port_cap[4], 1573 u8 color_spc) 1574 { 1575 if (!drm_dp_is_branch(dpcd)) 1576 return false; 1577 1578 if (dpcd[DP_DPCD_REV] < 0x13) 1579 return false; 1580 1581 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1582 case DP_DS_PORT_TYPE_HDMI: 1583 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1584 return false; 1585 1586 return port_cap[3] & color_spc; 1587 default: 1588 return false; 1589 } 1590 } 1591 EXPORT_SYMBOL(drm_dp_downstream_rgb_to_ycbcr_conversion); 1592 1593 /** 1594 * drm_dp_downstream_mode() - return a mode for downstream facing port 1595 * @dev: DRM device 1596 * @dpcd: DisplayPort configuration data 1597 * @port_cap: port capabilities 1598 * 1599 * Provides a suitable mode for downstream facing ports without EDID. 1600 * 1601 * Returns: A new drm_display_mode on success or NULL on failure 1602 */ 1603 struct drm_display_mode * 1604 drm_dp_downstream_mode(struct drm_device *dev, 1605 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1606 const u8 port_cap[4]) 1607 1608 { 1609 u8 vic; 1610 1611 if (!drm_dp_is_branch(dpcd)) 1612 return NULL; 1613 1614 if (dpcd[DP_DPCD_REV] < 0x11) 1615 return NULL; 1616 1617 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1618 case DP_DS_PORT_TYPE_NON_EDID: 1619 switch (port_cap[0] & DP_DS_NON_EDID_MASK) { 1620 case DP_DS_NON_EDID_720x480i_60: 1621 vic = 6; 1622 break; 1623 case DP_DS_NON_EDID_720x480i_50: 1624 vic = 21; 1625 break; 1626 case DP_DS_NON_EDID_1920x1080i_60: 1627 vic = 5; 1628 break; 1629 case DP_DS_NON_EDID_1920x1080i_50: 1630 vic = 20; 1631 break; 1632 case DP_DS_NON_EDID_1280x720_60: 1633 vic = 4; 1634 break; 1635 case DP_DS_NON_EDID_1280x720_50: 1636 vic = 19; 1637 break; 1638 default: 1639 return NULL; 1640 } 1641 return drm_display_mode_from_cea_vic(dev, vic); 1642 default: 1643 return NULL; 1644 } 1645 } 1646 EXPORT_SYMBOL(drm_dp_downstream_mode); 1647 1648 /** 1649 * drm_dp_downstream_id() - identify branch device 1650 * @aux: DisplayPort AUX channel 1651 * @id: DisplayPort branch device id 1652 * 1653 * Returns branch device id on success or NULL on failure 1654 */ 1655 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]) 1656 { 1657 return drm_dp_dpcd_read_data(aux, DP_BRANCH_ID, id, 6); 1658 } 1659 EXPORT_SYMBOL(drm_dp_downstream_id); 1660 1661 /** 1662 * drm_dp_downstream_debug() - debug DP branch devices 1663 * @m: pointer for debugfs file 1664 * @dpcd: DisplayPort configuration data 1665 * @port_cap: port capabilities 1666 * @drm_edid: EDID 1667 * @aux: DisplayPort AUX channel 1668 * 1669 */ 1670 void drm_dp_downstream_debug(struct seq_file *m, 1671 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1672 const u8 port_cap[4], 1673 const struct drm_edid *drm_edid, 1674 struct drm_dp_aux *aux) 1675 { 1676 bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & 1677 DP_DETAILED_CAP_INFO_AVAILABLE; 1678 int clk; 1679 int bpc; 1680 char id[7]; 1681 int len; 1682 uint8_t rev[2]; 1683 int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; 1684 bool branch_device = drm_dp_is_branch(dpcd); 1685 1686 seq_printf(m, "\tDP branch device present: %s\n", 1687 str_yes_no(branch_device)); 1688 1689 if (!branch_device) 1690 return; 1691 1692 switch (type) { 1693 case DP_DS_PORT_TYPE_DP: 1694 seq_puts(m, "\t\tType: DisplayPort\n"); 1695 break; 1696 case DP_DS_PORT_TYPE_VGA: 1697 seq_puts(m, "\t\tType: VGA\n"); 1698 break; 1699 case DP_DS_PORT_TYPE_DVI: 1700 seq_puts(m, "\t\tType: DVI\n"); 1701 break; 1702 case DP_DS_PORT_TYPE_HDMI: 1703 seq_puts(m, "\t\tType: HDMI\n"); 1704 break; 1705 case DP_DS_PORT_TYPE_NON_EDID: 1706 seq_puts(m, "\t\tType: others without EDID support\n"); 1707 break; 1708 case DP_DS_PORT_TYPE_DP_DUALMODE: 1709 seq_puts(m, "\t\tType: DP++\n"); 1710 break; 1711 case DP_DS_PORT_TYPE_WIRELESS: 1712 seq_puts(m, "\t\tType: Wireless\n"); 1713 break; 1714 default: 1715 seq_puts(m, "\t\tType: N/A\n"); 1716 } 1717 1718 memset(id, 0, sizeof(id)); 1719 drm_dp_downstream_id(aux, id); 1720 seq_printf(m, "\t\tID: %s\n", id); 1721 1722 len = drm_dp_dpcd_read_data(aux, DP_BRANCH_HW_REV, &rev[0], 1); 1723 if (!len) 1724 seq_printf(m, "\t\tHW: %d.%d\n", 1725 (rev[0] & 0xf0) >> 4, rev[0] & 0xf); 1726 1727 len = drm_dp_dpcd_read_data(aux, DP_BRANCH_SW_REV, rev, 2); 1728 if (!len) 1729 seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]); 1730 1731 if (detailed_cap_info) { 1732 clk = drm_dp_downstream_max_dotclock(dpcd, port_cap); 1733 if (clk > 0) 1734 seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); 1735 1736 clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, drm_edid); 1737 if (clk > 0) 1738 seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); 1739 1740 clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, drm_edid); 1741 if (clk > 0) 1742 seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk); 1743 1744 bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, drm_edid); 1745 1746 if (bpc > 0) 1747 seq_printf(m, "\t\tMax bpc: %d\n", bpc); 1748 } 1749 } 1750 EXPORT_SYMBOL(drm_dp_downstream_debug); 1751 1752 /** 1753 * drm_dp_subconnector_type() - get DP branch device type 1754 * @dpcd: DisplayPort configuration data 1755 * @port_cap: port capabilities 1756 */ 1757 enum drm_mode_subconnector 1758 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1759 const u8 port_cap[4]) 1760 { 1761 int type; 1762 if (!drm_dp_is_branch(dpcd)) 1763 return DRM_MODE_SUBCONNECTOR_Native; 1764 /* DP 1.0 approach */ 1765 if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) { 1766 type = dpcd[DP_DOWNSTREAMPORT_PRESENT] & 1767 DP_DWN_STRM_PORT_TYPE_MASK; 1768 1769 switch (type) { 1770 case DP_DWN_STRM_PORT_TYPE_TMDS: 1771 /* Can be HDMI or DVI-D, DVI-D is a safer option */ 1772 return DRM_MODE_SUBCONNECTOR_DVID; 1773 case DP_DWN_STRM_PORT_TYPE_ANALOG: 1774 /* Can be VGA or DVI-A, VGA is more popular */ 1775 return DRM_MODE_SUBCONNECTOR_VGA; 1776 case DP_DWN_STRM_PORT_TYPE_DP: 1777 return DRM_MODE_SUBCONNECTOR_DisplayPort; 1778 case DP_DWN_STRM_PORT_TYPE_OTHER: 1779 default: 1780 return DRM_MODE_SUBCONNECTOR_Unknown; 1781 } 1782 } 1783 type = port_cap[0] & DP_DS_PORT_TYPE_MASK; 1784 1785 switch (type) { 1786 case DP_DS_PORT_TYPE_DP: 1787 case DP_DS_PORT_TYPE_DP_DUALMODE: 1788 return DRM_MODE_SUBCONNECTOR_DisplayPort; 1789 case DP_DS_PORT_TYPE_VGA: 1790 return DRM_MODE_SUBCONNECTOR_VGA; 1791 case DP_DS_PORT_TYPE_DVI: 1792 return DRM_MODE_SUBCONNECTOR_DVID; 1793 case DP_DS_PORT_TYPE_HDMI: 1794 return DRM_MODE_SUBCONNECTOR_HDMIA; 1795 case DP_DS_PORT_TYPE_WIRELESS: 1796 return DRM_MODE_SUBCONNECTOR_Wireless; 1797 case DP_DS_PORT_TYPE_NON_EDID: 1798 default: 1799 return DRM_MODE_SUBCONNECTOR_Unknown; 1800 } 1801 } 1802 EXPORT_SYMBOL(drm_dp_subconnector_type); 1803 1804 /** 1805 * drm_dp_set_subconnector_property - set subconnector for DP connector 1806 * @connector: connector to set property on 1807 * @status: connector status 1808 * @dpcd: DisplayPort configuration data 1809 * @port_cap: port capabilities 1810 * 1811 * Called by a driver on every detect event. 1812 */ 1813 void drm_dp_set_subconnector_property(struct drm_connector *connector, 1814 enum drm_connector_status status, 1815 const u8 *dpcd, 1816 const u8 port_cap[4]) 1817 { 1818 enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown; 1819 1820 if (status == connector_status_connected) 1821 subconnector = drm_dp_subconnector_type(dpcd, port_cap); 1822 drm_object_property_set_value(&connector->base, 1823 connector->dev->mode_config.dp_subconnector_property, 1824 subconnector); 1825 } 1826 EXPORT_SYMBOL(drm_dp_set_subconnector_property); 1827 1828 /** 1829 * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink 1830 * count 1831 * @connector: The DRM connector to check 1832 * @dpcd: A cached copy of the connector's DPCD RX capabilities 1833 * @desc: A cached copy of the connector's DP descriptor 1834 * 1835 * See also: drm_dp_read_sink_count() 1836 * 1837 * Returns: %True if the (e)DP connector has a valid sink count that should 1838 * be probed, %false otherwise. 1839 */ 1840 bool drm_dp_read_sink_count_cap(struct drm_connector *connector, 1841 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1842 const struct drm_dp_desc *desc) 1843 { 1844 /* Some eDP panels don't set a valid value for the sink count */ 1845 return connector->connector_type != DRM_MODE_CONNECTOR_eDP && 1846 dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 && 1847 dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT && 1848 !drm_dp_has_quirk(desc, DP_DPCD_QUIRK_NO_SINK_COUNT); 1849 } 1850 EXPORT_SYMBOL(drm_dp_read_sink_count_cap); 1851 1852 /** 1853 * drm_dp_read_sink_count() - Retrieve the sink count for a given sink 1854 * @aux: The DP AUX channel to use 1855 * 1856 * See also: drm_dp_read_sink_count_cap() 1857 * 1858 * Returns: The current sink count reported by @aux, or a negative error code 1859 * otherwise. 1860 */ 1861 int drm_dp_read_sink_count(struct drm_dp_aux *aux) 1862 { 1863 u8 count; 1864 int ret; 1865 1866 ret = drm_dp_dpcd_read_byte(aux, DP_SINK_COUNT, &count); 1867 if (ret < 0) 1868 return ret; 1869 1870 return DP_GET_SINK_COUNT(count); 1871 } 1872 EXPORT_SYMBOL(drm_dp_read_sink_count); 1873 1874 /* 1875 * I2C-over-AUX implementation 1876 */ 1877 1878 static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) 1879 { 1880 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 1881 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 1882 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 1883 I2C_FUNC_10BIT_ADDR; 1884 } 1885 1886 static void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg) 1887 { 1888 /* 1889 * In case of i2c defer or short i2c ack reply to a write, 1890 * we need to switch to WRITE_STATUS_UPDATE to drain the 1891 * rest of the message 1892 */ 1893 if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) { 1894 msg->request &= DP_AUX_I2C_MOT; 1895 msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE; 1896 } 1897 } 1898 1899 #define AUX_PRECHARGE_LEN 10 /* 10 to 16 */ 1900 #define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */ 1901 #define AUX_STOP_LEN 4 1902 #define AUX_CMD_LEN 4 1903 #define AUX_ADDRESS_LEN 20 1904 #define AUX_REPLY_PAD_LEN 4 1905 #define AUX_LENGTH_LEN 8 1906 1907 /* 1908 * Calculate the duration of the AUX request/reply in usec. Gives the 1909 * "best" case estimate, ie. successful while as short as possible. 1910 */ 1911 static int drm_dp_aux_req_duration(const struct drm_dp_aux_msg *msg) 1912 { 1913 int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + 1914 AUX_CMD_LEN + AUX_ADDRESS_LEN + AUX_LENGTH_LEN; 1915 1916 if ((msg->request & DP_AUX_I2C_READ) == 0) 1917 len += msg->size * 8; 1918 1919 return len; 1920 } 1921 1922 static int drm_dp_aux_reply_duration(const struct drm_dp_aux_msg *msg) 1923 { 1924 int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + 1925 AUX_CMD_LEN + AUX_REPLY_PAD_LEN; 1926 1927 /* 1928 * For read we expect what was asked. For writes there will 1929 * be 0 or 1 data bytes. Assume 0 for the "best" case. 1930 */ 1931 if (msg->request & DP_AUX_I2C_READ) 1932 len += msg->size * 8; 1933 1934 return len; 1935 } 1936 1937 #define I2C_START_LEN 1 1938 #define I2C_STOP_LEN 1 1939 #define I2C_ADDR_LEN 9 /* ADDRESS + R/W + ACK/NACK */ 1940 #define I2C_DATA_LEN 9 /* DATA + ACK/NACK */ 1941 1942 /* 1943 * Calculate the length of the i2c transfer in usec, assuming 1944 * the i2c bus speed is as specified. Gives the "worst" 1945 * case estimate, ie. successful while as long as possible. 1946 * Doesn't account the "MOT" bit, and instead assumes each 1947 * message includes a START, ADDRESS and STOP. Neither does it 1948 * account for additional random variables such as clock stretching. 1949 */ 1950 static int drm_dp_i2c_msg_duration(const struct drm_dp_aux_msg *msg, 1951 int i2c_speed_khz) 1952 { 1953 /* AUX bitrate is 1MHz, i2c bitrate as specified */ 1954 return DIV_ROUND_UP((I2C_START_LEN + I2C_ADDR_LEN + 1955 msg->size * I2C_DATA_LEN + 1956 I2C_STOP_LEN) * 1000, i2c_speed_khz); 1957 } 1958 1959 /* 1960 * Determine how many retries should be attempted to successfully transfer 1961 * the specified message, based on the estimated durations of the 1962 * i2c and AUX transfers. 1963 */ 1964 static int drm_dp_i2c_retry_count(const struct drm_dp_aux_msg *msg, 1965 int i2c_speed_khz) 1966 { 1967 int aux_time_us = drm_dp_aux_req_duration(msg) + 1968 drm_dp_aux_reply_duration(msg); 1969 int i2c_time_us = drm_dp_i2c_msg_duration(msg, i2c_speed_khz); 1970 1971 return DIV_ROUND_UP(i2c_time_us, aux_time_us + AUX_RETRY_INTERVAL); 1972 } 1973 1974 /* 1975 * FIXME currently assumes 10 kHz as some real world devices seem 1976 * to require it. We should query/set the speed via DPCD if supported. 1977 */ 1978 static int dp_aux_i2c_speed_khz __read_mostly = 10; 1979 module_param_unsafe(dp_aux_i2c_speed_khz, int, 0644); 1980 MODULE_PARM_DESC(dp_aux_i2c_speed_khz, 1981 "Assumed speed of the i2c bus in kHz, (1-400, default 10)"); 1982 1983 /* 1984 * Transfer a single I2C-over-AUX message and handle various error conditions, 1985 * retrying the transaction as appropriate. It is assumed that the 1986 * &drm_dp_aux.transfer function does not modify anything in the msg other than the 1987 * reply field. 1988 * 1989 * Returns bytes transferred on success, or a negative error code on failure. 1990 */ 1991 static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) 1992 { 1993 unsigned int retry, defer_i2c; 1994 int ret; 1995 /* 1996 * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device 1997 * is required to retry at least seven times upon receiving AUX_DEFER 1998 * before giving up the AUX transaction. 1999 * 2000 * We also try to account for the i2c bus speed. 2001 */ 2002 int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz)); 2003 2004 for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { 2005 ret = aux->transfer(aux, msg); 2006 if (ret < 0) { 2007 if (ret == -EBUSY) 2008 continue; 2009 2010 /* 2011 * While timeouts can be errors, they're usually normal 2012 * behavior (for instance, when a driver tries to 2013 * communicate with a non-existent DisplayPort device). 2014 * Avoid spamming the kernel log with timeout errors. 2015 */ 2016 if (ret == -ETIMEDOUT) 2017 drm_dbg_kms_ratelimited(aux->drm_dev, "%s: transaction timed out\n", 2018 aux->name); 2019 else 2020 drm_dbg_kms(aux->drm_dev, "%s: transaction failed: %d\n", 2021 aux->name, ret); 2022 return ret; 2023 } 2024 2025 2026 switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { 2027 case DP_AUX_NATIVE_REPLY_ACK: 2028 /* 2029 * For I2C-over-AUX transactions this isn't enough, we 2030 * need to check for the I2C ACK reply. 2031 */ 2032 break; 2033 2034 case DP_AUX_NATIVE_REPLY_NACK: 2035 drm_dbg_kms(aux->drm_dev, "%s: native nack (result=%d, size=%zu)\n", 2036 aux->name, ret, msg->size); 2037 return -EREMOTEIO; 2038 2039 case DP_AUX_NATIVE_REPLY_DEFER: 2040 drm_dbg_kms(aux->drm_dev, "%s: native defer\n", aux->name); 2041 /* 2042 * We could check for I2C bit rate capabilities and if 2043 * available adjust this interval. We could also be 2044 * more careful with DP-to-legacy adapters where a 2045 * long legacy cable may force very low I2C bit rates. 2046 * 2047 * For now just defer for long enough to hopefully be 2048 * safe for all use-cases. 2049 */ 2050 usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); 2051 continue; 2052 2053 default: 2054 drm_err(aux->drm_dev, "%s: invalid native reply %#04x\n", 2055 aux->name, msg->reply); 2056 return -EREMOTEIO; 2057 } 2058 2059 switch (msg->reply & DP_AUX_I2C_REPLY_MASK) { 2060 case DP_AUX_I2C_REPLY_ACK: 2061 /* 2062 * Both native ACK and I2C ACK replies received. We 2063 * can assume the transfer was successful. 2064 */ 2065 if (ret != msg->size) 2066 drm_dp_i2c_msg_write_status_update(msg); 2067 return ret; 2068 2069 case DP_AUX_I2C_REPLY_NACK: 2070 drm_dbg_kms(aux->drm_dev, "%s: I2C nack (result=%d, size=%zu)\n", 2071 aux->name, ret, msg->size); 2072 aux->i2c_nack_count++; 2073 return -EREMOTEIO; 2074 2075 case DP_AUX_I2C_REPLY_DEFER: 2076 drm_dbg_kms(aux->drm_dev, "%s: I2C defer\n", aux->name); 2077 /* DP Compliance Test 4.2.2.5 Requirement: 2078 * Must have at least 7 retries for I2C defers on the 2079 * transaction to pass this test 2080 */ 2081 aux->i2c_defer_count++; 2082 if (defer_i2c < 7) 2083 defer_i2c++; 2084 usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); 2085 drm_dp_i2c_msg_write_status_update(msg); 2086 2087 continue; 2088 2089 default: 2090 drm_err(aux->drm_dev, "%s: invalid I2C reply %#04x\n", 2091 aux->name, msg->reply); 2092 return -EREMOTEIO; 2093 } 2094 } 2095 2096 drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up\n", aux->name); 2097 return -EREMOTEIO; 2098 } 2099 2100 static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg, 2101 const struct i2c_msg *i2c_msg) 2102 { 2103 msg->request = (i2c_msg->flags & I2C_M_RD) ? 2104 DP_AUX_I2C_READ : DP_AUX_I2C_WRITE; 2105 if (!(i2c_msg->flags & I2C_M_STOP)) 2106 msg->request |= DP_AUX_I2C_MOT; 2107 } 2108 2109 /* 2110 * Keep retrying drm_dp_i2c_do_msg until all data has been transferred. 2111 * 2112 * Returns an error code on failure, or a recommended transfer size on success. 2113 */ 2114 static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg) 2115 { 2116 int err, ret = orig_msg->size; 2117 struct drm_dp_aux_msg msg = *orig_msg; 2118 2119 while (msg.size > 0) { 2120 err = drm_dp_i2c_do_msg(aux, &msg); 2121 if (err <= 0) 2122 return err == 0 ? -EPROTO : err; 2123 2124 if (err < msg.size && err < ret) { 2125 drm_dbg_kms(aux->drm_dev, 2126 "%s: Partial I2C reply: requested %zu bytes got %d bytes\n", 2127 aux->name, msg.size, err); 2128 ret = err; 2129 } 2130 2131 msg.size -= err; 2132 msg.buffer += err; 2133 } 2134 2135 return ret; 2136 } 2137 2138 /* 2139 * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX 2140 * packets to be as large as possible. If not, the I2C transactions never 2141 * succeed. Hence the default is maximum. 2142 */ 2143 static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES; 2144 module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644); 2145 MODULE_PARM_DESC(dp_aux_i2c_transfer_size, 2146 "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)"); 2147 2148 static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, 2149 int num) 2150 { 2151 struct drm_dp_aux *aux = adapter->algo_data; 2152 unsigned int i, j; 2153 unsigned transfer_size; 2154 struct drm_dp_aux_msg msg; 2155 int err = 0; 2156 2157 if (aux->powered_down) 2158 return -EBUSY; 2159 2160 dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES); 2161 2162 memset(&msg, 0, sizeof(msg)); 2163 2164 for (i = 0; i < num; i++) { 2165 msg.address = msgs[i].addr; 2166 2167 if (!aux->no_zero_sized) { 2168 drm_dp_i2c_msg_set_request(&msg, &msgs[i]); 2169 /* Send a bare address packet to start the transaction. 2170 * Zero sized messages specify an address only (bare 2171 * address) transaction. 2172 */ 2173 msg.buffer = NULL; 2174 msg.size = 0; 2175 err = drm_dp_i2c_do_msg(aux, &msg); 2176 } 2177 2178 /* 2179 * Reset msg.request in case in case it got 2180 * changed into a WRITE_STATUS_UPDATE. 2181 */ 2182 drm_dp_i2c_msg_set_request(&msg, &msgs[i]); 2183 2184 if (err < 0) 2185 break; 2186 /* We want each transaction to be as large as possible, but 2187 * we'll go to smaller sizes if the hardware gives us a 2188 * short reply. 2189 */ 2190 transfer_size = dp_aux_i2c_transfer_size; 2191 for (j = 0; j < msgs[i].len; j += msg.size) { 2192 msg.buffer = msgs[i].buf + j; 2193 msg.size = min(transfer_size, msgs[i].len - j); 2194 2195 if (j + msg.size == msgs[i].len && aux->no_zero_sized) 2196 msg.request &= ~DP_AUX_I2C_MOT; 2197 err = drm_dp_i2c_drain_msg(aux, &msg); 2198 2199 /* 2200 * Reset msg.request in case in case it got 2201 * changed into a WRITE_STATUS_UPDATE. 2202 */ 2203 drm_dp_i2c_msg_set_request(&msg, &msgs[i]); 2204 2205 if (err < 0) 2206 break; 2207 transfer_size = err; 2208 } 2209 if (err < 0) 2210 break; 2211 } 2212 if (err >= 0) 2213 err = num; 2214 2215 if (!aux->no_zero_sized) { 2216 /* Send a bare address packet to close out the transaction. 2217 * Zero sized messages specify an address only (bare 2218 * address) transaction. 2219 */ 2220 msg.request &= ~DP_AUX_I2C_MOT; 2221 msg.buffer = NULL; 2222 msg.size = 0; 2223 (void)drm_dp_i2c_do_msg(aux, &msg); 2224 } 2225 return err; 2226 } 2227 2228 static const struct i2c_algorithm drm_dp_i2c_algo = { 2229 .functionality = drm_dp_i2c_functionality, 2230 .master_xfer = drm_dp_i2c_xfer, 2231 }; 2232 2233 static struct drm_dp_aux *i2c_to_aux(struct i2c_adapter *i2c) 2234 { 2235 return container_of(i2c, struct drm_dp_aux, ddc); 2236 } 2237 2238 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags) 2239 { 2240 mutex_lock(&i2c_to_aux(i2c)->hw_mutex); 2241 } 2242 2243 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags) 2244 { 2245 return mutex_trylock(&i2c_to_aux(i2c)->hw_mutex); 2246 } 2247 2248 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) 2249 { 2250 mutex_unlock(&i2c_to_aux(i2c)->hw_mutex); 2251 } 2252 2253 static const struct i2c_lock_operations drm_dp_i2c_lock_ops = { 2254 .lock_bus = lock_bus, 2255 .trylock_bus = trylock_bus, 2256 .unlock_bus = unlock_bus, 2257 }; 2258 2259 static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc) 2260 { 2261 u8 buf, count; 2262 int ret; 2263 2264 ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); 2265 if (ret < 0) 2266 return ret; 2267 2268 WARN_ON(!(buf & DP_TEST_SINK_START)); 2269 2270 ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK_MISC, &buf); 2271 if (ret < 0) 2272 return ret; 2273 2274 count = buf & DP_TEST_COUNT_MASK; 2275 if (count == aux->crc_count) 2276 return -EAGAIN; /* No CRC yet */ 2277 2278 aux->crc_count = count; 2279 2280 /* 2281 * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes 2282 * per component (RGB or CrYCb). 2283 */ 2284 return drm_dp_dpcd_read_data(aux, DP_TEST_CRC_R_CR, crc, 6); 2285 } 2286 2287 static void drm_dp_aux_crc_work(struct work_struct *work) 2288 { 2289 struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux, 2290 crc_work); 2291 struct drm_crtc *crtc; 2292 u8 crc_bytes[6]; 2293 uint32_t crcs[3]; 2294 int ret; 2295 2296 if (WARN_ON(!aux->crtc)) 2297 return; 2298 2299 crtc = aux->crtc; 2300 while (crtc->crc.opened) { 2301 drm_crtc_wait_one_vblank(crtc); 2302 if (!crtc->crc.opened) 2303 break; 2304 2305 ret = drm_dp_aux_get_crc(aux, crc_bytes); 2306 if (ret == -EAGAIN) { 2307 usleep_range(1000, 2000); 2308 ret = drm_dp_aux_get_crc(aux, crc_bytes); 2309 } 2310 2311 if (ret == -EAGAIN) { 2312 drm_dbg_kms(aux->drm_dev, "%s: Get CRC failed after retrying: %d\n", 2313 aux->name, ret); 2314 continue; 2315 } else if (ret) { 2316 drm_dbg_kms(aux->drm_dev, "%s: Failed to get a CRC: %d\n", aux->name, ret); 2317 continue; 2318 } 2319 2320 crcs[0] = crc_bytes[0] | crc_bytes[1] << 8; 2321 crcs[1] = crc_bytes[2] | crc_bytes[3] << 8; 2322 crcs[2] = crc_bytes[4] | crc_bytes[5] << 8; 2323 drm_crtc_add_crc_entry(crtc, false, 0, crcs); 2324 } 2325 } 2326 2327 /** 2328 * drm_dp_remote_aux_init() - minimally initialise a remote aux channel 2329 * @aux: DisplayPort AUX channel 2330 * 2331 * Used for remote aux channel in general. Merely initialize the crc work 2332 * struct. 2333 */ 2334 void drm_dp_remote_aux_init(struct drm_dp_aux *aux) 2335 { 2336 INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); 2337 } 2338 EXPORT_SYMBOL(drm_dp_remote_aux_init); 2339 2340 /** 2341 * drm_dp_aux_init() - minimally initialise an aux channel 2342 * @aux: DisplayPort AUX channel 2343 * 2344 * If you need to use the drm_dp_aux's i2c adapter prior to registering it with 2345 * the outside world, call drm_dp_aux_init() first. For drivers which are 2346 * grandparents to their AUX adapters (e.g. the AUX adapter is parented by a 2347 * &drm_connector), you must still call drm_dp_aux_register() once the connector 2348 * has been registered to allow userspace access to the auxiliary DP channel. 2349 * Likewise, for such drivers you should also assign &drm_dp_aux.drm_dev as 2350 * early as possible so that the &drm_device that corresponds to the AUX adapter 2351 * may be mentioned in debugging output from the DRM DP helpers. 2352 * 2353 * For devices which use a separate platform device for their AUX adapters, this 2354 * may be called as early as required by the driver. 2355 * 2356 */ 2357 void drm_dp_aux_init(struct drm_dp_aux *aux) 2358 { 2359 mutex_init(&aux->hw_mutex); 2360 mutex_init(&aux->cec.lock); 2361 INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); 2362 2363 aux->ddc.algo = &drm_dp_i2c_algo; 2364 aux->ddc.algo_data = aux; 2365 aux->ddc.retries = 3; 2366 2367 aux->ddc.lock_ops = &drm_dp_i2c_lock_ops; 2368 } 2369 EXPORT_SYMBOL(drm_dp_aux_init); 2370 2371 /** 2372 * drm_dp_aux_register() - initialise and register aux channel 2373 * @aux: DisplayPort AUX channel 2374 * 2375 * Automatically calls drm_dp_aux_init() if this hasn't been done yet. This 2376 * should only be called once the parent of @aux, &drm_dp_aux.dev, is 2377 * initialized. For devices which are grandparents of their AUX channels, 2378 * &drm_dp_aux.dev will typically be the &drm_connector &device which 2379 * corresponds to @aux. For these devices, it's advised to call 2380 * drm_dp_aux_register() in &drm_connector_funcs.late_register, and likewise to 2381 * call drm_dp_aux_unregister() in &drm_connector_funcs.early_unregister. 2382 * Functions which don't follow this will likely Oops when 2383 * %CONFIG_DRM_DISPLAY_DP_AUX_CHARDEV is enabled. 2384 * 2385 * For devices where the AUX channel is a device that exists independently of 2386 * the &drm_device that uses it, such as SoCs and bridge devices, it is 2387 * recommended to call drm_dp_aux_register() after a &drm_device has been 2388 * assigned to &drm_dp_aux.drm_dev, and likewise to call 2389 * drm_dp_aux_unregister() once the &drm_device should no longer be associated 2390 * with the AUX channel (e.g. on bridge detach). 2391 * 2392 * Drivers which need to use the aux channel before either of the two points 2393 * mentioned above need to call drm_dp_aux_init() in order to use the AUX 2394 * channel before registration. 2395 * 2396 * Returns 0 on success or a negative error code on failure. 2397 */ 2398 int drm_dp_aux_register(struct drm_dp_aux *aux) 2399 { 2400 int ret; 2401 2402 WARN_ON_ONCE(!aux->drm_dev); 2403 2404 if (!aux->ddc.algo) 2405 drm_dp_aux_init(aux); 2406 2407 aux->ddc.owner = THIS_MODULE; 2408 aux->ddc.dev.parent = aux->dev; 2409 2410 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), 2411 sizeof(aux->ddc.name)); 2412 2413 ret = drm_dp_aux_register_devnode(aux); 2414 if (ret) 2415 return ret; 2416 2417 ret = i2c_add_adapter(&aux->ddc); 2418 if (ret) { 2419 drm_dp_aux_unregister_devnode(aux); 2420 return ret; 2421 } 2422 2423 return 0; 2424 } 2425 EXPORT_SYMBOL(drm_dp_aux_register); 2426 2427 /** 2428 * drm_dp_aux_unregister() - unregister an AUX adapter 2429 * @aux: DisplayPort AUX channel 2430 */ 2431 void drm_dp_aux_unregister(struct drm_dp_aux *aux) 2432 { 2433 drm_dp_aux_unregister_devnode(aux); 2434 i2c_del_adapter(&aux->ddc); 2435 } 2436 EXPORT_SYMBOL(drm_dp_aux_unregister); 2437 2438 #define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x) 2439 2440 /** 2441 * drm_dp_psr_setup_time() - PSR setup in time usec 2442 * @psr_cap: PSR capabilities from DPCD 2443 * 2444 * Returns: 2445 * PSR setup time for the panel in microseconds, negative 2446 * error code on failure. 2447 */ 2448 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]) 2449 { 2450 static const u16 psr_setup_time_us[] = { 2451 PSR_SETUP_TIME(330), 2452 PSR_SETUP_TIME(275), 2453 PSR_SETUP_TIME(220), 2454 PSR_SETUP_TIME(165), 2455 PSR_SETUP_TIME(110), 2456 PSR_SETUP_TIME(55), 2457 PSR_SETUP_TIME(0), 2458 }; 2459 int i; 2460 2461 i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT; 2462 if (i >= ARRAY_SIZE(psr_setup_time_us)) 2463 return -EINVAL; 2464 2465 return psr_setup_time_us[i]; 2466 } 2467 EXPORT_SYMBOL(drm_dp_psr_setup_time); 2468 2469 #undef PSR_SETUP_TIME 2470 2471 /** 2472 * drm_dp_start_crc() - start capture of frame CRCs 2473 * @aux: DisplayPort AUX channel 2474 * @crtc: CRTC displaying the frames whose CRCs are to be captured 2475 * 2476 * Returns 0 on success or a negative error code on failure. 2477 */ 2478 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc) 2479 { 2480 u8 buf; 2481 int ret; 2482 2483 ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); 2484 if (ret < 0) 2485 return ret; 2486 2487 ret = drm_dp_dpcd_write_byte(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START); 2488 if (ret < 0) 2489 return ret; 2490 2491 aux->crc_count = 0; 2492 aux->crtc = crtc; 2493 schedule_work(&aux->crc_work); 2494 2495 return 0; 2496 } 2497 EXPORT_SYMBOL(drm_dp_start_crc); 2498 2499 /** 2500 * drm_dp_stop_crc() - stop capture of frame CRCs 2501 * @aux: DisplayPort AUX channel 2502 * 2503 * Returns 0 on success or a negative error code on failure. 2504 */ 2505 int drm_dp_stop_crc(struct drm_dp_aux *aux) 2506 { 2507 u8 buf; 2508 int ret; 2509 2510 ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); 2511 if (ret < 0) 2512 return ret; 2513 2514 ret = drm_dp_dpcd_write_byte(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START); 2515 if (ret < 0) 2516 return ret; 2517 2518 flush_work(&aux->crc_work); 2519 aux->crtc = NULL; 2520 2521 return 0; 2522 } 2523 EXPORT_SYMBOL(drm_dp_stop_crc); 2524 2525 struct dpcd_quirk { 2526 u8 oui[3]; 2527 u8 device_id[6]; 2528 bool is_branch; 2529 u32 quirks; 2530 }; 2531 2532 #define OUI(first, second, third) { (first), (second), (third) } 2533 #define DEVICE_ID(first, second, third, fourth, fifth, sixth) \ 2534 { (first), (second), (third), (fourth), (fifth), (sixth) } 2535 2536 #define DEVICE_ID_ANY DEVICE_ID(0, 0, 0, 0, 0, 0) 2537 2538 static const struct dpcd_quirk dpcd_quirk_list[] = { 2539 /* Analogix 7737 needs reduced M and N at HBR2 link rates */ 2540 { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, 2541 /* LG LP140WF6-SPM1 eDP panel */ 2542 { OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, 2543 /* Apple panels need some additional handling to support PSR */ 2544 { OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) }, 2545 /* CH7511 seems to leave SINK_COUNT zeroed */ 2546 { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) }, 2547 /* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */ 2548 { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) }, 2549 /* Synaptics DP1.4 MST hubs require DSC for some modes on which it applies HBLANK expansion. */ 2550 { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC) }, 2551 /* MediaTek panels (at least in U3224KBA) require DSC for modes with a short HBLANK on UHBR links. */ 2552 { OUI(0x00, 0x0C, 0xE7), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC) }, 2553 /* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */ 2554 { OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) }, 2555 /* Synaptics Panamera supports only a compressed bpp of 12 above 50% of its max DSC pixel throughput */ 2556 { OUI(0x90, 0xCC, 0x24), DEVICE_ID('S', 'Y', 'N', 'A', 0x53, 0x22), true, BIT(DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT) }, 2557 { OUI(0x90, 0xCC, 0x24), DEVICE_ID('S', 'Y', 'N', 'A', 0x53, 0x31), true, BIT(DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT) }, 2558 { OUI(0x90, 0xCC, 0x24), DEVICE_ID('S', 'Y', 'N', 'A', 0x53, 0x33), true, BIT(DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT) }, 2559 }; 2560 2561 #undef OUI 2562 2563 /* 2564 * Get a bit mask of DPCD quirks for the sink/branch device identified by 2565 * ident. The quirk data is shared but it's up to the drivers to act on the 2566 * data. 2567 * 2568 * For now, only the OUI (first three bytes) is used, but this may be extended 2569 * to device identification string and hardware/firmware revisions later. 2570 */ 2571 static u32 2572 drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) 2573 { 2574 const struct dpcd_quirk *quirk; 2575 u32 quirks = 0; 2576 int i; 2577 u8 any_device[] = DEVICE_ID_ANY; 2578 2579 for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { 2580 quirk = &dpcd_quirk_list[i]; 2581 2582 if (quirk->is_branch != is_branch) 2583 continue; 2584 2585 if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) 2586 continue; 2587 2588 if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 && 2589 memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0) 2590 continue; 2591 2592 quirks |= quirk->quirks; 2593 } 2594 2595 return quirks; 2596 } 2597 2598 #undef DEVICE_ID_ANY 2599 #undef DEVICE_ID 2600 2601 static int drm_dp_read_ident(struct drm_dp_aux *aux, unsigned int offset, 2602 struct drm_dp_dpcd_ident *ident) 2603 { 2604 return drm_dp_dpcd_read_data(aux, offset, ident, sizeof(*ident)); 2605 } 2606 2607 static void drm_dp_dump_desc(struct drm_dp_aux *aux, 2608 const char *device_name, const struct drm_dp_desc *desc) 2609 { 2610 const struct drm_dp_dpcd_ident *ident = &desc->ident; 2611 2612 drm_dbg_kms(aux->drm_dev, 2613 "%s: %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", 2614 aux->name, device_name, 2615 (int)sizeof(ident->oui), ident->oui, 2616 (int)strnlen(ident->device_id, sizeof(ident->device_id)), ident->device_id, 2617 ident->hw_rev >> 4, ident->hw_rev & 0xf, 2618 ident->sw_major_rev, ident->sw_minor_rev, 2619 desc->quirks); 2620 } 2621 2622 /** 2623 * drm_dp_read_desc - read sink/branch descriptor from DPCD 2624 * @aux: DisplayPort AUX channel 2625 * @desc: Device descriptor to fill from DPCD 2626 * @is_branch: true for branch devices, false for sink devices 2627 * 2628 * Read DPCD 0x400 (sink) or 0x500 (branch) into @desc. Also debug log the 2629 * identification. 2630 * 2631 * Returns 0 on success or a negative error code on failure. 2632 */ 2633 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, 2634 bool is_branch) 2635 { 2636 struct drm_dp_dpcd_ident *ident = &desc->ident; 2637 unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI; 2638 int ret; 2639 2640 ret = drm_dp_read_ident(aux, offset, ident); 2641 if (ret < 0) 2642 return ret; 2643 2644 desc->quirks = drm_dp_get_quirks(ident, is_branch); 2645 2646 drm_dp_dump_desc(aux, is_branch ? "DP branch" : "DP sink", desc); 2647 2648 return 0; 2649 } 2650 EXPORT_SYMBOL(drm_dp_read_desc); 2651 2652 /** 2653 * drm_dp_dump_lttpr_desc - read and dump the DPCD descriptor for an LTTPR PHY 2654 * @aux: DisplayPort AUX channel 2655 * @dp_phy: LTTPR PHY instance 2656 * 2657 * Read the DPCD LTTPR PHY descriptor for @dp_phy and print a debug message 2658 * with its details to dmesg. 2659 * 2660 * Returns 0 on success or a negative error code on failure. 2661 */ 2662 int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy) 2663 { 2664 struct drm_dp_desc desc = {}; 2665 int ret; 2666 2667 if (drm_WARN_ON(aux->drm_dev, dp_phy < DP_PHY_LTTPR1 || dp_phy > DP_MAX_LTTPR_COUNT)) 2668 return -EINVAL; 2669 2670 ret = drm_dp_read_ident(aux, DP_OUI_PHY_REPEATER(dp_phy), &desc.ident); 2671 if (ret < 0) 2672 return ret; 2673 2674 drm_dp_dump_desc(aux, drm_dp_phy_name(dp_phy), &desc); 2675 2676 return 0; 2677 } 2678 EXPORT_SYMBOL(drm_dp_dump_lttpr_desc); 2679 2680 /** 2681 * drm_dp_dsc_sink_bpp_incr() - Get bits per pixel increment 2682 * @dsc_dpcd: DSC capabilities from DPCD 2683 * 2684 * Returns the bpp precision supported by the DP sink. 2685 */ 2686 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 2687 { 2688 u8 bpp_increment_dpcd = dsc_dpcd[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT]; 2689 2690 switch (bpp_increment_dpcd & DP_DSC_BITS_PER_PIXEL_MASK) { 2691 case DP_DSC_BITS_PER_PIXEL_1_16: 2692 return 16; 2693 case DP_DSC_BITS_PER_PIXEL_1_8: 2694 return 8; 2695 case DP_DSC_BITS_PER_PIXEL_1_4: 2696 return 4; 2697 case DP_DSC_BITS_PER_PIXEL_1_2: 2698 return 2; 2699 case DP_DSC_BITS_PER_PIXEL_1_1: 2700 return 1; 2701 } 2702 2703 return 0; 2704 } 2705 EXPORT_SYMBOL(drm_dp_dsc_sink_bpp_incr); 2706 2707 /** 2708 * drm_dp_dsc_sink_max_slice_count() - Get the max slice count 2709 * supported by the DSC sink. 2710 * @dsc_dpcd: DSC capabilities from DPCD 2711 * @is_edp: true if its eDP, false for DP 2712 * 2713 * Read the slice capabilities DPCD register from DSC sink to get 2714 * the maximum slice count supported. This is used to populate 2715 * the DSC parameters in the &struct drm_dsc_config by the driver. 2716 * Driver creates an infoframe using these parameters to populate 2717 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2718 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2719 * 2720 * Returns: 2721 * Maximum slice count supported by DSC sink or 0 its invalid 2722 */ 2723 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 2724 bool is_edp) 2725 { 2726 u8 slice_cap1 = dsc_dpcd[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT]; 2727 2728 if (is_edp) { 2729 /* For eDP, register DSC_SLICE_CAPABILITIES_1 gives slice count */ 2730 if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) 2731 return 4; 2732 if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) 2733 return 2; 2734 if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) 2735 return 1; 2736 } else { 2737 /* For DP, use values from DSC_SLICE_CAP_1 and DSC_SLICE_CAP2 */ 2738 u8 slice_cap2 = dsc_dpcd[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT]; 2739 2740 if (slice_cap2 & DP_DSC_24_PER_DP_DSC_SINK) 2741 return 24; 2742 if (slice_cap2 & DP_DSC_20_PER_DP_DSC_SINK) 2743 return 20; 2744 if (slice_cap2 & DP_DSC_16_PER_DP_DSC_SINK) 2745 return 16; 2746 if (slice_cap1 & DP_DSC_12_PER_DP_DSC_SINK) 2747 return 12; 2748 if (slice_cap1 & DP_DSC_10_PER_DP_DSC_SINK) 2749 return 10; 2750 if (slice_cap1 & DP_DSC_8_PER_DP_DSC_SINK) 2751 return 8; 2752 if (slice_cap1 & DP_DSC_6_PER_DP_DSC_SINK) 2753 return 6; 2754 if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) 2755 return 4; 2756 if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) 2757 return 2; 2758 if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) 2759 return 1; 2760 } 2761 2762 return 0; 2763 } 2764 EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count); 2765 2766 /** 2767 * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits 2768 * @dsc_dpcd: DSC capabilities from DPCD 2769 * 2770 * Read the DSC DPCD register to parse the line buffer depth in bits which is 2771 * number of bits of precision within the decoder line buffer supported by 2772 * the DSC sink. This is used to populate the DSC parameters in the 2773 * &struct drm_dsc_config by the driver. 2774 * Driver creates an infoframe using these parameters to populate 2775 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2776 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2777 * 2778 * Returns: 2779 * Line buffer depth supported by DSC panel or 0 its invalid 2780 */ 2781 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 2782 { 2783 u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT]; 2784 2785 switch (line_buf_depth & DP_DSC_LINE_BUF_BIT_DEPTH_MASK) { 2786 case DP_DSC_LINE_BUF_BIT_DEPTH_9: 2787 return 9; 2788 case DP_DSC_LINE_BUF_BIT_DEPTH_10: 2789 return 10; 2790 case DP_DSC_LINE_BUF_BIT_DEPTH_11: 2791 return 11; 2792 case DP_DSC_LINE_BUF_BIT_DEPTH_12: 2793 return 12; 2794 case DP_DSC_LINE_BUF_BIT_DEPTH_13: 2795 return 13; 2796 case DP_DSC_LINE_BUF_BIT_DEPTH_14: 2797 return 14; 2798 case DP_DSC_LINE_BUF_BIT_DEPTH_15: 2799 return 15; 2800 case DP_DSC_LINE_BUF_BIT_DEPTH_16: 2801 return 16; 2802 case DP_DSC_LINE_BUF_BIT_DEPTH_8: 2803 return 8; 2804 } 2805 2806 return 0; 2807 } 2808 EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth); 2809 2810 /** 2811 * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component 2812 * values supported by the DSC sink. 2813 * @dsc_dpcd: DSC capabilities from DPCD 2814 * @dsc_bpc: An array to be filled by this helper with supported 2815 * input bpcs. 2816 * 2817 * Read the DSC DPCD from the sink device to parse the supported bits per 2818 * component values. This is used to populate the DSC parameters 2819 * in the &struct drm_dsc_config by the driver. 2820 * Driver creates an infoframe using these parameters to populate 2821 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2822 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2823 * 2824 * Returns: 2825 * Number of input BPC values parsed from the DPCD 2826 */ 2827 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 2828 u8 dsc_bpc[3]) 2829 { 2830 int num_bpc = 0; 2831 u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT]; 2832 2833 if (!drm_dp_sink_supports_dsc(dsc_dpcd)) 2834 return 0; 2835 2836 if (color_depth & DP_DSC_12_BPC) 2837 dsc_bpc[num_bpc++] = 12; 2838 if (color_depth & DP_DSC_10_BPC) 2839 dsc_bpc[num_bpc++] = 10; 2840 2841 /* A DP DSC Sink device shall support 8 bpc. */ 2842 dsc_bpc[num_bpc++] = 8; 2843 2844 return num_bpc; 2845 } 2846 EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); 2847 2848 /* 2849 * See DP Standard v2.1a 2.8.4 Minimum Slices/Display, Table 2-159 and 2850 * Appendix L.1 Derivation of Slice Count Requirements. 2851 */ 2852 static int dsc_sink_min_slice_throughput(int peak_pixel_rate) 2853 { 2854 if (peak_pixel_rate >= 4800000) 2855 return 600000; 2856 else if (peak_pixel_rate >= 2700000) 2857 return 400000; 2858 else 2859 return 340000; 2860 } 2861 2862 /** 2863 * drm_dp_dsc_sink_max_slice_throughput() - Get a DSC sink's maximum pixel throughput per slice 2864 * @dsc_dpcd: DSC sink's capabilities from DPCD 2865 * @peak_pixel_rate: Cumulative peak pixel rate in kHz 2866 * @is_rgb_yuv444: The mode is either RGB or YUV444 2867 * 2868 * Return the DSC sink device's maximum pixel throughput per slice, based on 2869 * the device's @dsc_dpcd capabilities, the @peak_pixel_rate of the transferred 2870 * stream(s) and whether the output format @is_rgb_yuv444 or yuv422/yuv420. 2871 * 2872 * Note that @peak_pixel_rate is the total pixel rate transferred to the same 2873 * DSC/display sink. For instance to calculate a tile's slice count of an MST 2874 * multi-tiled display sink (not considering here the required 2875 * rounding/alignment of slice count):: 2876 * 2877 * @peak_pixel_rate = tile_pixel_rate * tile_count 2878 * total_slice_count = @peak_pixel_rate / drm_dp_dsc_sink_max_slice_throughput(@peak_pixel_rate) 2879 * tile_slice_count = total_slice_count / tile_count 2880 * 2881 * Returns: 2882 * The maximum pixel throughput per slice supported by the DSC sink device 2883 * in kPixels/sec. 2884 */ 2885 int drm_dp_dsc_sink_max_slice_throughput(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 2886 int peak_pixel_rate, bool is_rgb_yuv444) 2887 { 2888 int throughput; 2889 int delta = 0; 2890 int base; 2891 2892 throughput = dsc_dpcd[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT]; 2893 2894 if (is_rgb_yuv444) { 2895 throughput = (throughput & DP_DSC_THROUGHPUT_MODE_0_MASK) >> 2896 DP_DSC_THROUGHPUT_MODE_0_SHIFT; 2897 2898 delta = ((dsc_dpcd[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT]) & 2899 DP_DSC_THROUGHPUT_MODE_0_DELTA_MASK) >> 2900 DP_DSC_THROUGHPUT_MODE_0_DELTA_SHIFT; /* in units of 2 MPixels/sec */ 2901 delta *= 2000; 2902 } else { 2903 throughput = (throughput & DP_DSC_THROUGHPUT_MODE_1_MASK) >> 2904 DP_DSC_THROUGHPUT_MODE_1_SHIFT; 2905 } 2906 2907 switch (throughput) { 2908 case 0: 2909 return dsc_sink_min_slice_throughput(peak_pixel_rate); 2910 case 1: 2911 base = 340000; 2912 break; 2913 case 2 ... 14: 2914 base = 400000 + 50000 * (throughput - 2); 2915 break; 2916 case 15: 2917 base = 170000; 2918 break; 2919 } 2920 2921 return base + delta; 2922 } 2923 EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_throughput); 2924 2925 static u8 dsc_branch_dpcd_cap(const u8 dpcd[DP_DSC_BRANCH_CAP_SIZE], int reg) 2926 { 2927 return dpcd[reg - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0]; 2928 } 2929 2930 /** 2931 * drm_dp_dsc_branch_max_overall_throughput() - Branch device's max overall DSC pixel throughput 2932 * @dsc_branch_dpcd: DSC branch capabilities from DPCD 2933 * @is_rgb_yuv444: The mode is either RGB or YUV444 2934 * 2935 * Return the branch device's maximum overall DSC pixel throughput, based on 2936 * the device's DPCD DSC branch capabilities, and whether the output 2937 * format @is_rgb_yuv444 or yuv422/yuv420. 2938 * 2939 * Returns: 2940 * - 0: The maximum overall throughput capability is not indicated by 2941 * the device separately and it must be determined from the per-slice 2942 * max throughput (see @drm_dp_dsc_branch_slice_max_throughput()) 2943 * and the maximum slice count supported by the device. 2944 * - > 0: The maximum overall DSC pixel throughput supported by the branch 2945 * device in kPixels/sec. 2946 */ 2947 int drm_dp_dsc_branch_max_overall_throughput(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE], 2948 bool is_rgb_yuv444) 2949 { 2950 int throughput; 2951 2952 if (is_rgb_yuv444) 2953 throughput = dsc_branch_dpcd_cap(dsc_branch_dpcd, 2954 DP_DSC_BRANCH_OVERALL_THROUGHPUT_0); 2955 else 2956 throughput = dsc_branch_dpcd_cap(dsc_branch_dpcd, 2957 DP_DSC_BRANCH_OVERALL_THROUGHPUT_1); 2958 2959 switch (throughput) { 2960 case 0: 2961 return 0; 2962 case 1: 2963 return 680000; 2964 default: 2965 return 600000 + 50000 * throughput; 2966 } 2967 } 2968 EXPORT_SYMBOL(drm_dp_dsc_branch_max_overall_throughput); 2969 2970 /** 2971 * drm_dp_dsc_branch_max_line_width() - Branch device's max DSC line width 2972 * @dsc_branch_dpcd: DSC branch capabilities from DPCD 2973 * 2974 * Return the branch device's maximum overall DSC line width, based on 2975 * the device's @dsc_branch_dpcd capabilities. 2976 * 2977 * Returns: 2978 * - 0: The maximum line width is not indicated by the device 2979 * separately and it must be determined from the maximum 2980 * slice count and slice-width supported by the device. 2981 * - %-EINVAL: The device indicates an invalid maximum line width 2982 * (< 5120 pixels). 2983 * - >= 5120: The maximum line width in pixels. 2984 */ 2985 int drm_dp_dsc_branch_max_line_width(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE]) 2986 { 2987 int line_width = dsc_branch_dpcd_cap(dsc_branch_dpcd, DP_DSC_BRANCH_MAX_LINE_WIDTH); 2988 2989 switch (line_width) { 2990 case 0: 2991 return 0; 2992 case 1 ... 15: 2993 return -EINVAL; 2994 default: 2995 return line_width * 320; 2996 } 2997 } 2998 EXPORT_SYMBOL(drm_dp_dsc_branch_max_line_width); 2999 3000 static int drm_dp_read_lttpr_regs(struct drm_dp_aux *aux, 3001 const u8 dpcd[DP_RECEIVER_CAP_SIZE], int address, 3002 u8 *buf, int buf_size) 3003 { 3004 /* 3005 * At least the DELL P2715Q monitor with a DPCD_REV < 0x14 returns 3006 * corrupted values when reading from the 0xF0000- range with a block 3007 * size bigger than 1. 3008 */ 3009 int block_size = dpcd[DP_DPCD_REV] < 0x14 ? 1 : buf_size; 3010 int offset; 3011 int ret; 3012 3013 for (offset = 0; offset < buf_size; offset += block_size) { 3014 ret = drm_dp_dpcd_read_data(aux, 3015 address + offset, 3016 &buf[offset], block_size); 3017 if (ret < 0) 3018 return ret; 3019 } 3020 3021 return 0; 3022 } 3023 3024 /** 3025 * drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities 3026 * @aux: DisplayPort AUX channel 3027 * @dpcd: DisplayPort configuration data 3028 * @caps: buffer to return the capability info in 3029 * 3030 * Read capabilities common to all LTTPRs. 3031 * 3032 * Returns 0 on success or a negative error code on failure. 3033 */ 3034 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, 3035 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 3036 u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 3037 { 3038 return drm_dp_read_lttpr_regs(aux, dpcd, 3039 DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, 3040 caps, DP_LTTPR_COMMON_CAP_SIZE); 3041 } 3042 EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps); 3043 3044 /** 3045 * drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY 3046 * @aux: DisplayPort AUX channel 3047 * @dpcd: DisplayPort configuration data 3048 * @dp_phy: LTTPR PHY to read the capabilities for 3049 * @caps: buffer to return the capability info in 3050 * 3051 * Read the capabilities for the given LTTPR PHY. 3052 * 3053 * Returns 0 on success or a negative error code on failure. 3054 */ 3055 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux, 3056 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 3057 enum drm_dp_phy dp_phy, 3058 u8 caps[DP_LTTPR_PHY_CAP_SIZE]) 3059 { 3060 return drm_dp_read_lttpr_regs(aux, dpcd, 3061 DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy), 3062 caps, DP_LTTPR_PHY_CAP_SIZE); 3063 } 3064 EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps); 3065 3066 static u8 dp_lttpr_common_cap(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE], int r) 3067 { 3068 return caps[r - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV]; 3069 } 3070 3071 /** 3072 * drm_dp_lttpr_count - get the number of detected LTTPRs 3073 * @caps: LTTPR common capabilities 3074 * 3075 * Get the number of detected LTTPRs from the LTTPR common capabilities info. 3076 * 3077 * Returns: 3078 * -ERANGE if more than supported number (8) of LTTPRs are detected 3079 * -EINVAL if the DP_PHY_REPEATER_CNT register contains an invalid value 3080 * otherwise the number of detected LTTPRs 3081 */ 3082 int drm_dp_lttpr_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 3083 { 3084 u8 count = dp_lttpr_common_cap(caps, DP_PHY_REPEATER_CNT); 3085 3086 switch (hweight8(count)) { 3087 case 0: 3088 return 0; 3089 case 1: 3090 return 8 - ilog2(count); 3091 case 8: 3092 return -ERANGE; 3093 default: 3094 return -EINVAL; 3095 } 3096 } 3097 EXPORT_SYMBOL(drm_dp_lttpr_count); 3098 3099 /** 3100 * drm_dp_lttpr_max_link_rate - get the maximum link rate supported by all LTTPRs 3101 * @caps: LTTPR common capabilities 3102 * 3103 * Returns the maximum link rate supported by all detected LTTPRs. 3104 */ 3105 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 3106 { 3107 u8 rate = dp_lttpr_common_cap(caps, DP_MAX_LINK_RATE_PHY_REPEATER); 3108 3109 return drm_dp_bw_code_to_link_rate(rate); 3110 } 3111 EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate); 3112 3113 /** 3114 * drm_dp_lttpr_set_transparent_mode() - set the LTTPR in transparent mode 3115 * @aux: DisplayPort AUX channel 3116 * @enable: Enable or disable transparent mode 3117 * 3118 * Returns: 0 on success or a negative error code on failure. 3119 */ 3120 int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable) 3121 { 3122 u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : 3123 DP_PHY_REPEATER_MODE_NON_TRANSPARENT; 3124 int ret = drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE, val); 3125 3126 if (ret < 0) 3127 return ret; 3128 3129 return (ret == 1) ? 0 : -EIO; 3130 } 3131 EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); 3132 3133 /** 3134 * drm_dp_lttpr_init() - init LTTPR transparency mode according to DP standard 3135 * @aux: DisplayPort AUX channel 3136 * @lttpr_count: Number of LTTPRs. Between 0 and 8, according to DP standard. 3137 * Negative error code for any non-valid number. 3138 * See drm_dp_lttpr_count(). 3139 * 3140 * Returns: 0 on success or a negative error code on failure. 3141 */ 3142 int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count) 3143 { 3144 int ret; 3145 3146 if (!lttpr_count) 3147 return 0; 3148 3149 /* 3150 * See DP Standard v2.0 3.6.6.1 about the explicit disabling of 3151 * non-transparent mode and the disable->enable non-transparent mode 3152 * sequence. 3153 */ 3154 ret = drm_dp_lttpr_set_transparent_mode(aux, true); 3155 if (ret) 3156 return ret; 3157 3158 if (lttpr_count < 0) 3159 return -ENODEV; 3160 3161 if (drm_dp_lttpr_set_transparent_mode(aux, false)) { 3162 /* 3163 * Roll-back to transparent mode if setting non-transparent 3164 * mode has failed 3165 */ 3166 drm_dp_lttpr_set_transparent_mode(aux, true); 3167 return -EINVAL; 3168 } 3169 3170 return 0; 3171 } 3172 EXPORT_SYMBOL(drm_dp_lttpr_init); 3173 3174 /** 3175 * drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs 3176 * @caps: LTTPR common capabilities 3177 * 3178 * Returns the maximum lane count supported by all detected LTTPRs. 3179 */ 3180 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 3181 { 3182 u8 max_lanes = dp_lttpr_common_cap(caps, DP_MAX_LANE_COUNT_PHY_REPEATER); 3183 3184 return max_lanes & DP_MAX_LANE_COUNT_MASK; 3185 } 3186 EXPORT_SYMBOL(drm_dp_lttpr_max_lane_count); 3187 3188 /** 3189 * drm_dp_lttpr_voltage_swing_level_3_supported - check for LTTPR vswing3 support 3190 * @caps: LTTPR PHY capabilities 3191 * 3192 * Returns true if the @caps for an LTTPR TX PHY indicate support for 3193 * voltage swing level 3. 3194 */ 3195 bool 3196 drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) 3197 { 3198 u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); 3199 3200 return txcap & DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED; 3201 } 3202 EXPORT_SYMBOL(drm_dp_lttpr_voltage_swing_level_3_supported); 3203 3204 /** 3205 * drm_dp_lttpr_pre_emphasis_level_3_supported - check for LTTPR preemph3 support 3206 * @caps: LTTPR PHY capabilities 3207 * 3208 * Returns true if the @caps for an LTTPR TX PHY indicate support for 3209 * pre-emphasis level 3. 3210 */ 3211 bool 3212 drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) 3213 { 3214 u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); 3215 3216 return txcap & DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED; 3217 } 3218 EXPORT_SYMBOL(drm_dp_lttpr_pre_emphasis_level_3_supported); 3219 3220 /** 3221 * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink. 3222 * @aux: DisplayPort AUX channel 3223 * @data: DP phy compliance test parameters. 3224 * 3225 * Returns 0 on success or a negative error code on failure. 3226 */ 3227 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, 3228 struct drm_dp_phy_test_params *data) 3229 { 3230 int err; 3231 u8 rate, lanes; 3232 3233 err = drm_dp_dpcd_read_byte(aux, DP_TEST_LINK_RATE, &rate); 3234 if (err < 0) 3235 return err; 3236 data->link_rate = drm_dp_bw_code_to_link_rate(rate); 3237 3238 err = drm_dp_dpcd_read_byte(aux, DP_TEST_LANE_COUNT, &lanes); 3239 if (err < 0) 3240 return err; 3241 data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK; 3242 3243 if (lanes & DP_ENHANCED_FRAME_CAP) 3244 data->enhanced_frame_cap = true; 3245 3246 err = drm_dp_dpcd_read_byte(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern); 3247 if (err < 0) 3248 return err; 3249 3250 switch (data->phy_pattern) { 3251 case DP_PHY_TEST_PATTERN_80BIT_CUSTOM: 3252 err = drm_dp_dpcd_read_data(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0, 3253 &data->custom80, sizeof(data->custom80)); 3254 if (err < 0) 3255 return err; 3256 3257 break; 3258 case DP_PHY_TEST_PATTERN_CP2520: 3259 err = drm_dp_dpcd_read_data(aux, DP_TEST_HBR2_SCRAMBLER_RESET, 3260 &data->hbr2_reset, 3261 sizeof(data->hbr2_reset)); 3262 if (err < 0) 3263 return err; 3264 } 3265 3266 return 0; 3267 } 3268 EXPORT_SYMBOL(drm_dp_get_phy_test_pattern); 3269 3270 /** 3271 * drm_dp_set_phy_test_pattern() - set the pattern to the sink. 3272 * @aux: DisplayPort AUX channel 3273 * @data: DP phy compliance test parameters. 3274 * @dp_rev: DP revision to use for compliance testing 3275 * 3276 * Returns 0 on success or a negative error code on failure. 3277 */ 3278 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, 3279 struct drm_dp_phy_test_params *data, u8 dp_rev) 3280 { 3281 int err, i; 3282 u8 test_pattern; 3283 3284 test_pattern = data->phy_pattern; 3285 if (dp_rev < 0x12) { 3286 test_pattern = (test_pattern << 2) & 3287 DP_LINK_QUAL_PATTERN_11_MASK; 3288 err = drm_dp_dpcd_write_byte(aux, DP_TRAINING_PATTERN_SET, 3289 test_pattern); 3290 if (err < 0) 3291 return err; 3292 } else { 3293 for (i = 0; i < data->num_lanes; i++) { 3294 err = drm_dp_dpcd_write_byte(aux, 3295 DP_LINK_QUAL_LANE0_SET + i, 3296 test_pattern); 3297 if (err < 0) 3298 return err; 3299 } 3300 } 3301 3302 return 0; 3303 } 3304 EXPORT_SYMBOL(drm_dp_set_phy_test_pattern); 3305 3306 static const char *dp_pixelformat_get_name(enum dp_pixelformat pixelformat) 3307 { 3308 if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) 3309 return "Invalid"; 3310 3311 switch (pixelformat) { 3312 case DP_PIXELFORMAT_RGB: 3313 return "RGB"; 3314 case DP_PIXELFORMAT_YUV444: 3315 return "YUV444"; 3316 case DP_PIXELFORMAT_YUV422: 3317 return "YUV422"; 3318 case DP_PIXELFORMAT_YUV420: 3319 return "YUV420"; 3320 case DP_PIXELFORMAT_Y_ONLY: 3321 return "Y_ONLY"; 3322 case DP_PIXELFORMAT_RAW: 3323 return "RAW"; 3324 default: 3325 return "Reserved"; 3326 } 3327 } 3328 3329 static const char *dp_colorimetry_get_name(enum dp_pixelformat pixelformat, 3330 enum dp_colorimetry colorimetry) 3331 { 3332 if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) 3333 return "Invalid"; 3334 3335 switch (colorimetry) { 3336 case DP_COLORIMETRY_DEFAULT: 3337 switch (pixelformat) { 3338 case DP_PIXELFORMAT_RGB: 3339 return "sRGB"; 3340 case DP_PIXELFORMAT_YUV444: 3341 case DP_PIXELFORMAT_YUV422: 3342 case DP_PIXELFORMAT_YUV420: 3343 return "BT.601"; 3344 case DP_PIXELFORMAT_Y_ONLY: 3345 return "DICOM PS3.14"; 3346 case DP_PIXELFORMAT_RAW: 3347 return "Custom Color Profile"; 3348 default: 3349 return "Reserved"; 3350 } 3351 case DP_COLORIMETRY_RGB_WIDE_FIXED: /* and DP_COLORIMETRY_BT709_YCC */ 3352 switch (pixelformat) { 3353 case DP_PIXELFORMAT_RGB: 3354 return "Wide Fixed"; 3355 case DP_PIXELFORMAT_YUV444: 3356 case DP_PIXELFORMAT_YUV422: 3357 case DP_PIXELFORMAT_YUV420: 3358 return "BT.709"; 3359 default: 3360 return "Reserved"; 3361 } 3362 case DP_COLORIMETRY_RGB_WIDE_FLOAT: /* and DP_COLORIMETRY_XVYCC_601 */ 3363 switch (pixelformat) { 3364 case DP_PIXELFORMAT_RGB: 3365 return "Wide Float"; 3366 case DP_PIXELFORMAT_YUV444: 3367 case DP_PIXELFORMAT_YUV422: 3368 case DP_PIXELFORMAT_YUV420: 3369 return "xvYCC 601"; 3370 default: 3371 return "Reserved"; 3372 } 3373 case DP_COLORIMETRY_OPRGB: /* and DP_COLORIMETRY_XVYCC_709 */ 3374 switch (pixelformat) { 3375 case DP_PIXELFORMAT_RGB: 3376 return "OpRGB"; 3377 case DP_PIXELFORMAT_YUV444: 3378 case DP_PIXELFORMAT_YUV422: 3379 case DP_PIXELFORMAT_YUV420: 3380 return "xvYCC 709"; 3381 default: 3382 return "Reserved"; 3383 } 3384 case DP_COLORIMETRY_DCI_P3_RGB: /* and DP_COLORIMETRY_SYCC_601 */ 3385 switch (pixelformat) { 3386 case DP_PIXELFORMAT_RGB: 3387 return "DCI-P3"; 3388 case DP_PIXELFORMAT_YUV444: 3389 case DP_PIXELFORMAT_YUV422: 3390 case DP_PIXELFORMAT_YUV420: 3391 return "sYCC 601"; 3392 default: 3393 return "Reserved"; 3394 } 3395 case DP_COLORIMETRY_RGB_CUSTOM: /* and DP_COLORIMETRY_OPYCC_601 */ 3396 switch (pixelformat) { 3397 case DP_PIXELFORMAT_RGB: 3398 return "Custom Profile"; 3399 case DP_PIXELFORMAT_YUV444: 3400 case DP_PIXELFORMAT_YUV422: 3401 case DP_PIXELFORMAT_YUV420: 3402 return "OpYCC 601"; 3403 default: 3404 return "Reserved"; 3405 } 3406 case DP_COLORIMETRY_BT2020_RGB: /* and DP_COLORIMETRY_BT2020_CYCC */ 3407 switch (pixelformat) { 3408 case DP_PIXELFORMAT_RGB: 3409 return "BT.2020 RGB"; 3410 case DP_PIXELFORMAT_YUV444: 3411 case DP_PIXELFORMAT_YUV422: 3412 case DP_PIXELFORMAT_YUV420: 3413 return "BT.2020 CYCC"; 3414 default: 3415 return "Reserved"; 3416 } 3417 case DP_COLORIMETRY_BT2020_YCC: 3418 switch (pixelformat) { 3419 case DP_PIXELFORMAT_YUV444: 3420 case DP_PIXELFORMAT_YUV422: 3421 case DP_PIXELFORMAT_YUV420: 3422 return "BT.2020 YCC"; 3423 default: 3424 return "Reserved"; 3425 } 3426 default: 3427 return "Invalid"; 3428 } 3429 } 3430 3431 static const char *dp_dynamic_range_get_name(enum dp_dynamic_range dynamic_range) 3432 { 3433 switch (dynamic_range) { 3434 case DP_DYNAMIC_RANGE_VESA: 3435 return "VESA range"; 3436 case DP_DYNAMIC_RANGE_CTA: 3437 return "CTA range"; 3438 default: 3439 return "Invalid"; 3440 } 3441 } 3442 3443 static const char *dp_content_type_get_name(enum dp_content_type content_type) 3444 { 3445 switch (content_type) { 3446 case DP_CONTENT_TYPE_NOT_DEFINED: 3447 return "Not defined"; 3448 case DP_CONTENT_TYPE_GRAPHICS: 3449 return "Graphics"; 3450 case DP_CONTENT_TYPE_PHOTO: 3451 return "Photo"; 3452 case DP_CONTENT_TYPE_VIDEO: 3453 return "Video"; 3454 case DP_CONTENT_TYPE_GAME: 3455 return "Game"; 3456 default: 3457 return "Reserved"; 3458 } 3459 } 3460 3461 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc) 3462 { 3463 drm_printf(p, "DP SDP: VSC, revision %u, length %u\n", 3464 vsc->revision, vsc->length); 3465 drm_printf(p, " pixelformat: %s\n", 3466 dp_pixelformat_get_name(vsc->pixelformat)); 3467 drm_printf(p, " colorimetry: %s\n", 3468 dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry)); 3469 drm_printf(p, " bpc: %u\n", vsc->bpc); 3470 drm_printf(p, " dynamic range: %s\n", 3471 dp_dynamic_range_get_name(vsc->dynamic_range)); 3472 drm_printf(p, " content type: %s\n", 3473 dp_content_type_get_name(vsc->content_type)); 3474 } 3475 EXPORT_SYMBOL(drm_dp_vsc_sdp_log); 3476 3477 void drm_dp_as_sdp_log(struct drm_printer *p, const struct drm_dp_as_sdp *as_sdp) 3478 { 3479 drm_printf(p, "DP SDP: AS_SDP, revision %u, length %u\n", 3480 as_sdp->revision, as_sdp->length); 3481 drm_printf(p, " vtotal: %d\n", as_sdp->vtotal); 3482 drm_printf(p, " target_rr: %d\n", as_sdp->target_rr); 3483 drm_printf(p, " duration_incr_ms: %d\n", as_sdp->duration_incr_ms); 3484 drm_printf(p, " duration_decr_ms: %d\n", as_sdp->duration_decr_ms); 3485 drm_printf(p, " operation_mode: %d\n", as_sdp->mode); 3486 } 3487 EXPORT_SYMBOL(drm_dp_as_sdp_log); 3488 3489 /** 3490 * drm_dp_as_sdp_supported() - check if adaptive sync sdp is supported 3491 * @aux: DisplayPort AUX channel 3492 * @dpcd: DisplayPort configuration data 3493 * 3494 * Returns true if adaptive sync sdp is supported, else returns false 3495 */ 3496 bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 3497 { 3498 u8 rx_feature; 3499 3500 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_13) 3501 return false; 3502 3503 if (drm_dp_dpcd_read_byte(aux, DP_DPRX_FEATURE_ENUMERATION_LIST_CONT_1, 3504 &rx_feature) < 0) { 3505 drm_dbg_dp(aux->drm_dev, 3506 "Failed to read DP_DPRX_FEATURE_ENUMERATION_LIST_CONT_1\n"); 3507 return false; 3508 } 3509 3510 return (rx_feature & DP_ADAPTIVE_SYNC_SDP_SUPPORTED); 3511 } 3512 EXPORT_SYMBOL(drm_dp_as_sdp_supported); 3513 3514 /** 3515 * drm_dp_vsc_sdp_supported() - check if vsc sdp is supported 3516 * @aux: DisplayPort AUX channel 3517 * @dpcd: DisplayPort configuration data 3518 * 3519 * Returns true if vsc sdp is supported, else returns false 3520 */ 3521 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 3522 { 3523 u8 rx_feature; 3524 3525 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_13) 3526 return false; 3527 3528 if (drm_dp_dpcd_read_byte(aux, DP_DPRX_FEATURE_ENUMERATION_LIST, &rx_feature) < 0) { 3529 drm_dbg_dp(aux->drm_dev, "failed to read DP_DPRX_FEATURE_ENUMERATION_LIST\n"); 3530 return false; 3531 } 3532 3533 return (rx_feature & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED); 3534 } 3535 EXPORT_SYMBOL(drm_dp_vsc_sdp_supported); 3536 3537 /** 3538 * drm_dp_vsc_sdp_pack() - pack a given vsc sdp into generic dp_sdp 3539 * @vsc: vsc sdp initialized according to its purpose as defined in 3540 * table 2-118 - table 2-120 in DP 1.4a specification 3541 * @sdp: valid handle to the generic dp_sdp which will be packed 3542 * 3543 * Returns length of sdp on success and error code on failure 3544 */ 3545 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, 3546 struct dp_sdp *sdp) 3547 { 3548 size_t length = sizeof(struct dp_sdp); 3549 3550 memset(sdp, 0, sizeof(struct dp_sdp)); 3551 3552 /* 3553 * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119 3554 * VSC SDP Header Bytes 3555 */ 3556 sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */ 3557 sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */ 3558 sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */ 3559 sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */ 3560 3561 if (vsc->revision == 0x6) { 3562 sdp->db[0] = 1; 3563 sdp->db[3] = 1; 3564 } 3565 3566 /* 3567 * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry 3568 * Format as per DP 1.4a spec and DP 2.0 respectively. 3569 */ 3570 if (!(vsc->revision == 0x5 || vsc->revision == 0x7)) 3571 goto out; 3572 3573 /* VSC SDP Payload for DB16 through DB18 */ 3574 /* Pixel Encoding and Colorimetry Formats */ 3575 sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */ 3576 sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */ 3577 3578 switch (vsc->bpc) { 3579 case 6: 3580 /* 6bpc: 0x0 */ 3581 break; 3582 case 8: 3583 sdp->db[17] = 0x1; /* DB17[3:0] */ 3584 break; 3585 case 10: 3586 sdp->db[17] = 0x2; 3587 break; 3588 case 12: 3589 sdp->db[17] = 0x3; 3590 break; 3591 case 16: 3592 sdp->db[17] = 0x4; 3593 break; 3594 default: 3595 WARN(1, "Missing case %d\n", vsc->bpc); 3596 return -EINVAL; 3597 } 3598 3599 /* Dynamic Range and Component Bit Depth */ 3600 if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA) 3601 sdp->db[17] |= 0x80; /* DB17[7] */ 3602 3603 /* Content Type */ 3604 sdp->db[18] = vsc->content_type & 0x7; 3605 3606 out: 3607 return length; 3608 } 3609 EXPORT_SYMBOL(drm_dp_vsc_sdp_pack); 3610 3611 /** 3612 * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON 3613 * @dpcd: DisplayPort configuration data 3614 * @port_cap: port capabilities 3615 * 3616 * Returns maximum frl bandwidth supported by PCON in GBPS, 3617 * returns 0 if not supported. 3618 */ 3619 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 3620 const u8 port_cap[4]) 3621 { 3622 int bw; 3623 u8 buf; 3624 3625 buf = port_cap[2]; 3626 bw = buf & DP_PCON_MAX_FRL_BW; 3627 3628 switch (bw) { 3629 case DP_PCON_MAX_9GBPS: 3630 return 9; 3631 case DP_PCON_MAX_18GBPS: 3632 return 18; 3633 case DP_PCON_MAX_24GBPS: 3634 return 24; 3635 case DP_PCON_MAX_32GBPS: 3636 return 32; 3637 case DP_PCON_MAX_40GBPS: 3638 return 40; 3639 case DP_PCON_MAX_48GBPS: 3640 return 48; 3641 case DP_PCON_MAX_0GBPS: 3642 default: 3643 return 0; 3644 } 3645 3646 return 0; 3647 } 3648 EXPORT_SYMBOL(drm_dp_get_pcon_max_frl_bw); 3649 3650 /** 3651 * drm_dp_pcon_frl_prepare() - Prepare PCON for FRL. 3652 * @aux: DisplayPort AUX channel 3653 * @enable_frl_ready_hpd: Configure DP_PCON_ENABLE_HPD_READY. 3654 * 3655 * Returns 0 if success, else returns negative error code. 3656 */ 3657 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd) 3658 { 3659 u8 buf = DP_PCON_ENABLE_SOURCE_CTL_MODE | 3660 DP_PCON_ENABLE_LINK_FRL_MODE; 3661 3662 if (enable_frl_ready_hpd) 3663 buf |= DP_PCON_ENABLE_HPD_READY; 3664 3665 return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); 3666 } 3667 EXPORT_SYMBOL(drm_dp_pcon_frl_prepare); 3668 3669 /** 3670 * drm_dp_pcon_is_frl_ready() - Is PCON ready for FRL 3671 * @aux: DisplayPort AUX channel 3672 * 3673 * Returns true if success, else returns false. 3674 */ 3675 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux) 3676 { 3677 int ret; 3678 u8 buf; 3679 3680 ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); 3681 if (ret < 0) 3682 return false; 3683 3684 if (buf & DP_PCON_FRL_READY) 3685 return true; 3686 3687 return false; 3688 } 3689 EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready); 3690 3691 /** 3692 * drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1 3693 * @aux: DisplayPort AUX channel 3694 * @max_frl_gbps: maximum frl bw to be configured between PCON and HDMI sink 3695 * @frl_mode: FRL Training mode, it can be either Concurrent or Sequential. 3696 * In Concurrent Mode, the FRL link bring up can be done along with 3697 * DP Link training. In Sequential mode, the FRL link bring up is done prior to 3698 * the DP Link training. 3699 * 3700 * Returns 0 if success, else returns negative error code. 3701 */ 3702 3703 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps, 3704 u8 frl_mode) 3705 { 3706 int ret; 3707 u8 buf; 3708 3709 ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); 3710 if (ret < 0) 3711 return ret; 3712 3713 if (frl_mode == DP_PCON_ENABLE_CONCURRENT_LINK) 3714 buf |= DP_PCON_ENABLE_CONCURRENT_LINK; 3715 else 3716 buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK; 3717 3718 switch (max_frl_gbps) { 3719 case 9: 3720 buf |= DP_PCON_ENABLE_MAX_BW_9GBPS; 3721 break; 3722 case 18: 3723 buf |= DP_PCON_ENABLE_MAX_BW_18GBPS; 3724 break; 3725 case 24: 3726 buf |= DP_PCON_ENABLE_MAX_BW_24GBPS; 3727 break; 3728 case 32: 3729 buf |= DP_PCON_ENABLE_MAX_BW_32GBPS; 3730 break; 3731 case 40: 3732 buf |= DP_PCON_ENABLE_MAX_BW_40GBPS; 3733 break; 3734 case 48: 3735 buf |= DP_PCON_ENABLE_MAX_BW_48GBPS; 3736 break; 3737 case 0: 3738 buf |= DP_PCON_ENABLE_MAX_BW_0GBPS; 3739 break; 3740 default: 3741 return -EINVAL; 3742 } 3743 3744 return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); 3745 } 3746 EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1); 3747 3748 /** 3749 * drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2 3750 * @aux: DisplayPort AUX channel 3751 * @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink 3752 * @frl_type : FRL training type, can be Extended, or Normal. 3753 * In Normal FRL training, the PCON tries each frl bw from the max_frl_mask 3754 * starting from min, and stops when link training is successful. In Extended 3755 * FRL training, all frl bw selected in the mask are trained by the PCON. 3756 * 3757 * Returns 0 if success, else returns negative error code. 3758 */ 3759 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask, 3760 u8 frl_type) 3761 { 3762 int ret; 3763 u8 buf = max_frl_mask; 3764 3765 if (frl_type == DP_PCON_FRL_LINK_TRAIN_EXTENDED) 3766 buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED; 3767 else 3768 buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED; 3769 3770 return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf); 3771 if (ret < 0) 3772 return ret; 3773 3774 return 0; 3775 } 3776 EXPORT_SYMBOL(drm_dp_pcon_frl_configure_2); 3777 3778 /** 3779 * drm_dp_pcon_reset_frl_config() - Re-Set HDMI Link configuration. 3780 * @aux: DisplayPort AUX channel 3781 * 3782 * Returns 0 if success, else returns negative error code. 3783 */ 3784 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux) 3785 { 3786 return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0); 3787 } 3788 EXPORT_SYMBOL(drm_dp_pcon_reset_frl_config); 3789 3790 /** 3791 * drm_dp_pcon_frl_enable() - Enable HDMI link through FRL 3792 * @aux: DisplayPort AUX channel 3793 * 3794 * Returns 0 if success, else returns negative error code. 3795 */ 3796 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux) 3797 { 3798 int ret; 3799 u8 buf = 0; 3800 3801 ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); 3802 if (ret < 0) 3803 return ret; 3804 if (!(buf & DP_PCON_ENABLE_SOURCE_CTL_MODE)) { 3805 drm_dbg_kms(aux->drm_dev, "%s: PCON in Autonomous mode, can't enable FRL\n", 3806 aux->name); 3807 return -EINVAL; 3808 } 3809 buf |= DP_PCON_ENABLE_HDMI_LINK; 3810 return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); 3811 } 3812 EXPORT_SYMBOL(drm_dp_pcon_frl_enable); 3813 3814 /** 3815 * drm_dp_pcon_hdmi_link_active() - check if the PCON HDMI LINK status is active. 3816 * @aux: DisplayPort AUX channel 3817 * 3818 * Returns true if link is active else returns false. 3819 */ 3820 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux) 3821 { 3822 u8 buf; 3823 int ret; 3824 3825 ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); 3826 if (ret < 0) 3827 return false; 3828 3829 return buf & DP_PCON_HDMI_TX_LINK_ACTIVE; 3830 } 3831 EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_active); 3832 3833 /** 3834 * drm_dp_pcon_hdmi_link_mode() - get the PCON HDMI LINK MODE 3835 * @aux: DisplayPort AUX channel 3836 * @frl_trained_mask: pointer to store bitmask of the trained bw configuration. 3837 * Valid only if the MODE returned is FRL. For Normal Link training mode 3838 * only 1 of the bits will be set, but in case of Extended mode, more than 3839 * one bits can be set. 3840 * 3841 * Returns the link mode : TMDS or FRL on success, else returns negative error 3842 * code. 3843 */ 3844 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask) 3845 { 3846 u8 buf; 3847 int mode; 3848 int ret; 3849 3850 ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_POST_FRL_STATUS, &buf); 3851 if (ret < 0) 3852 return ret; 3853 3854 mode = buf & DP_PCON_HDMI_LINK_MODE; 3855 3856 if (frl_trained_mask && DP_PCON_HDMI_MODE_FRL == mode) 3857 *frl_trained_mask = (buf & DP_PCON_HDMI_FRL_TRAINED_BW) >> 1; 3858 3859 return mode; 3860 } 3861 EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_mode); 3862 3863 /** 3864 * drm_dp_pcon_hdmi_frl_link_error_count() - print the error count per lane 3865 * during link failure between PCON and HDMI sink 3866 * @aux: DisplayPort AUX channel 3867 * @connector: DRM connector 3868 * code. 3869 **/ 3870 3871 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux, 3872 struct drm_connector *connector) 3873 { 3874 u8 buf, error_count; 3875 int i, num_error; 3876 struct drm_hdmi_info *hdmi = &connector->display_info.hdmi; 3877 3878 for (i = 0; i < hdmi->max_lanes; i++) { 3879 if (drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_ERROR_STATUS_LN0 + i, &buf) < 0) 3880 return; 3881 3882 error_count = buf & DP_PCON_HDMI_ERROR_COUNT_MASK; 3883 switch (error_count) { 3884 case DP_PCON_HDMI_ERROR_COUNT_HUNDRED_PLUS: 3885 num_error = 100; 3886 break; 3887 case DP_PCON_HDMI_ERROR_COUNT_TEN_PLUS: 3888 num_error = 10; 3889 break; 3890 case DP_PCON_HDMI_ERROR_COUNT_THREE_PLUS: 3891 num_error = 3; 3892 break; 3893 default: 3894 num_error = 0; 3895 } 3896 3897 drm_err(aux->drm_dev, "%s: More than %d errors since the last read for lane %d", 3898 aux->name, num_error, i); 3899 } 3900 } 3901 EXPORT_SYMBOL(drm_dp_pcon_hdmi_frl_link_error_count); 3902 3903 /* 3904 * drm_dp_pcon_enc_is_dsc_1_2 - Does PCON Encoder supports DSC 1.2 3905 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3906 * 3907 * Returns true is PCON encoder is DSC 1.2 else returns false. 3908 */ 3909 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3910 { 3911 u8 buf; 3912 u8 major_v, minor_v; 3913 3914 buf = pcon_dsc_dpcd[DP_PCON_DSC_VERSION - DP_PCON_DSC_ENCODER]; 3915 major_v = (buf & DP_PCON_DSC_MAJOR_MASK) >> DP_PCON_DSC_MAJOR_SHIFT; 3916 minor_v = (buf & DP_PCON_DSC_MINOR_MASK) >> DP_PCON_DSC_MINOR_SHIFT; 3917 3918 if (major_v == 1 && minor_v == 2) 3919 return true; 3920 3921 return false; 3922 } 3923 EXPORT_SYMBOL(drm_dp_pcon_enc_is_dsc_1_2); 3924 3925 /* 3926 * drm_dp_pcon_dsc_max_slices - Get max slices supported by PCON DSC Encoder 3927 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3928 * 3929 * Returns maximum no. of slices supported by the PCON DSC Encoder. 3930 */ 3931 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3932 { 3933 u8 slice_cap1, slice_cap2; 3934 3935 slice_cap1 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_1 - DP_PCON_DSC_ENCODER]; 3936 slice_cap2 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_2 - DP_PCON_DSC_ENCODER]; 3937 3938 if (slice_cap2 & DP_PCON_DSC_24_PER_DSC_ENC) 3939 return 24; 3940 if (slice_cap2 & DP_PCON_DSC_20_PER_DSC_ENC) 3941 return 20; 3942 if (slice_cap2 & DP_PCON_DSC_16_PER_DSC_ENC) 3943 return 16; 3944 if (slice_cap1 & DP_PCON_DSC_12_PER_DSC_ENC) 3945 return 12; 3946 if (slice_cap1 & DP_PCON_DSC_10_PER_DSC_ENC) 3947 return 10; 3948 if (slice_cap1 & DP_PCON_DSC_8_PER_DSC_ENC) 3949 return 8; 3950 if (slice_cap1 & DP_PCON_DSC_6_PER_DSC_ENC) 3951 return 6; 3952 if (slice_cap1 & DP_PCON_DSC_4_PER_DSC_ENC) 3953 return 4; 3954 if (slice_cap1 & DP_PCON_DSC_2_PER_DSC_ENC) 3955 return 2; 3956 if (slice_cap1 & DP_PCON_DSC_1_PER_DSC_ENC) 3957 return 1; 3958 3959 return 0; 3960 } 3961 EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slices); 3962 3963 /* 3964 * drm_dp_pcon_dsc_max_slice_width() - Get max slice width for Pcon DSC encoder 3965 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3966 * 3967 * Returns maximum width of the slices in pixel width i.e. no. of pixels x 320. 3968 */ 3969 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3970 { 3971 u8 buf; 3972 3973 buf = pcon_dsc_dpcd[DP_PCON_DSC_MAX_SLICE_WIDTH - DP_PCON_DSC_ENCODER]; 3974 3975 return buf * DP_DSC_SLICE_WIDTH_MULTIPLIER; 3976 } 3977 EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slice_width); 3978 3979 /* 3980 * drm_dp_pcon_dsc_bpp_incr() - Get bits per pixel increment for PCON DSC encoder 3981 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3982 * 3983 * Returns the bpp precision supported by the PCON encoder. 3984 */ 3985 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3986 { 3987 u8 buf; 3988 3989 buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER]; 3990 3991 switch (buf & DP_PCON_DSC_BPP_INCR_MASK) { 3992 case DP_PCON_DSC_ONE_16TH_BPP: 3993 return 16; 3994 case DP_PCON_DSC_ONE_8TH_BPP: 3995 return 8; 3996 case DP_PCON_DSC_ONE_4TH_BPP: 3997 return 4; 3998 case DP_PCON_DSC_ONE_HALF_BPP: 3999 return 2; 4000 case DP_PCON_DSC_ONE_BPP: 4001 return 1; 4002 } 4003 4004 return 0; 4005 } 4006 EXPORT_SYMBOL(drm_dp_pcon_dsc_bpp_incr); 4007 4008 static 4009 int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config) 4010 { 4011 u8 buf; 4012 int ret; 4013 4014 ret = drm_dp_dpcd_read_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); 4015 if (ret < 0) 4016 return ret; 4017 4018 buf |= DP_PCON_ENABLE_DSC_ENCODER; 4019 4020 if (pps_buf_config <= DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER) { 4021 buf &= ~DP_PCON_ENCODER_PPS_OVERRIDE_MASK; 4022 buf |= pps_buf_config << 2; 4023 } 4024 4025 return drm_dp_dpcd_write_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); 4026 } 4027 4028 /** 4029 * drm_dp_pcon_pps_default() - Let PCON fill the default pps parameters 4030 * for DSC1.2 between PCON & HDMI2.1 sink 4031 * @aux: DisplayPort AUX channel 4032 * 4033 * Returns 0 on success, else returns negative error code. 4034 */ 4035 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux) 4036 { 4037 return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_DISABLED); 4038 } 4039 EXPORT_SYMBOL(drm_dp_pcon_pps_default); 4040 4041 /** 4042 * drm_dp_pcon_pps_override_buf() - Configure PPS encoder override buffer for 4043 * HDMI sink 4044 * @aux: DisplayPort AUX channel 4045 * @pps_buf: 128 bytes to be written into PPS buffer for HDMI sink by PCON. 4046 * 4047 * Returns 0 on success, else returns negative error code. 4048 */ 4049 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]) 4050 { 4051 int ret; 4052 4053 ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVERRIDE_BASE, &pps_buf, 128); 4054 if (ret < 0) 4055 return ret; 4056 4057 return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); 4058 } 4059 EXPORT_SYMBOL(drm_dp_pcon_pps_override_buf); 4060 4061 /* 4062 * drm_dp_pcon_pps_override_param() - Write PPS parameters to DSC encoder 4063 * override registers 4064 * @aux: DisplayPort AUX channel 4065 * @pps_param: 3 Parameters (2 Bytes each) : Slice Width, Slice Height, 4066 * bits_per_pixel. 4067 * 4068 * Returns 0 on success, else returns negative error code. 4069 */ 4070 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]) 4071 { 4072 int ret; 4073 4074 ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_HEIGHT, &pps_param[0], 2); 4075 if (ret < 0) 4076 return ret; 4077 ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_WIDTH, &pps_param[2], 2); 4078 if (ret < 0) 4079 return ret; 4080 ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_BPP, &pps_param[4], 2); 4081 if (ret < 0) 4082 return ret; 4083 4084 return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); 4085 } 4086 EXPORT_SYMBOL(drm_dp_pcon_pps_override_param); 4087 4088 /* 4089 * drm_dp_pcon_convert_rgb_to_ycbcr() - Configure the PCon to convert RGB to Ycbcr 4090 * @aux: displayPort AUX channel 4091 * @color_spc: Color-space/s for which conversion is to be enabled, 0 for disable. 4092 * 4093 * Returns 0 on success, else returns negative error code. 4094 */ 4095 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc) 4096 { 4097 int ret; 4098 u8 buf; 4099 4100 ret = drm_dp_dpcd_read_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); 4101 if (ret < 0) 4102 return ret; 4103 4104 if (color_spc & DP_CONVERSION_RGB_YCBCR_MASK) 4105 buf |= (color_spc & DP_CONVERSION_RGB_YCBCR_MASK); 4106 else 4107 buf &= ~DP_CONVERSION_RGB_YCBCR_MASK; 4108 4109 return drm_dp_dpcd_write_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); 4110 } 4111 EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr); 4112 4113 /** 4114 * drm_edp_backlight_set_level() - Set the backlight level of an eDP panel via AUX 4115 * @aux: The DP AUX channel to use 4116 * @bl: Backlight capability info from drm_edp_backlight_init() 4117 * @level: The brightness level to set 4118 * 4119 * Sets the brightness level of an eDP panel's backlight. Note that the panel's backlight must 4120 * already have been enabled by the driver by calling drm_edp_backlight_enable(). 4121 * 4122 * Returns: %0 on success, negative error code on failure 4123 */ 4124 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 4125 u32 level) 4126 { 4127 int ret; 4128 unsigned int offset = DP_EDP_BACKLIGHT_BRIGHTNESS_MSB; 4129 u8 buf[3] = { 0 }; 4130 size_t len = 2; 4131 4132 /* The panel uses the PWM for controlling brightness levels */ 4133 if (!(bl->aux_set || bl->luminance_set)) 4134 return 0; 4135 4136 if (bl->luminance_set) { 4137 level = level * 1000; 4138 level &= 0xffffff; 4139 buf[0] = (level & 0x0000ff); 4140 buf[1] = (level & 0x00ff00) >> 8; 4141 buf[2] = (level & 0xff0000) >> 16; 4142 offset = DP_EDP_PANEL_TARGET_LUMINANCE_VALUE; 4143 len = 3; 4144 } else if (bl->lsb_reg_used) { 4145 buf[0] = (level & 0xff00) >> 8; 4146 buf[1] = (level & 0x00ff); 4147 } else { 4148 buf[0] = level; 4149 } 4150 4151 ret = drm_dp_dpcd_write_data(aux, offset, buf, len); 4152 if (ret < 0) { 4153 drm_err(aux->drm_dev, 4154 "%s: Failed to write aux backlight level: %d\n", 4155 aux->name, ret); 4156 return ret; 4157 } 4158 4159 return 0; 4160 } 4161 EXPORT_SYMBOL(drm_edp_backlight_set_level); 4162 4163 static int 4164 drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 4165 bool enable) 4166 { 4167 int ret; 4168 u8 buf; 4169 4170 /* This panel uses the EDP_BL_PWR GPIO for enablement */ 4171 if (!bl->aux_enable) 4172 return 0; 4173 4174 ret = drm_dp_dpcd_read_byte(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &buf); 4175 if (ret < 0) { 4176 drm_err(aux->drm_dev, "%s: Failed to read eDP display control register: %d\n", 4177 aux->name, ret); 4178 return ret; 4179 } 4180 if (enable) 4181 buf |= DP_EDP_BACKLIGHT_ENABLE; 4182 else 4183 buf &= ~DP_EDP_BACKLIGHT_ENABLE; 4184 4185 ret = drm_dp_dpcd_write_byte(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, buf); 4186 if (ret < 0) { 4187 drm_err(aux->drm_dev, "%s: Failed to write eDP display control register: %d\n", 4188 aux->name, ret); 4189 return ret; 4190 } 4191 4192 return 0; 4193 } 4194 4195 /** 4196 * drm_edp_backlight_enable() - Enable an eDP panel's backlight using DPCD 4197 * @aux: The DP AUX channel to use 4198 * @bl: Backlight capability info from drm_edp_backlight_init() 4199 * @level: The initial backlight level to set via AUX, if there is one 4200 * 4201 * This function handles enabling DPCD backlight controls on a panel over DPCD, while additionally 4202 * restoring any important backlight state such as the given backlight level, the brightness byte 4203 * count, backlight frequency, etc. 4204 * 4205 * Note that certain panels do not support being enabled or disabled via DPCD, but instead require 4206 * that the driver handle enabling/disabling the panel through implementation-specific means using 4207 * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false, 4208 * this function becomes a no-op, and the driver is expected to handle powering the panel on using 4209 * the EDP_BL_PWR GPIO. 4210 * 4211 * Returns: %0 on success, negative error code on failure. 4212 */ 4213 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 4214 const u32 level) 4215 { 4216 int ret; 4217 u8 dpcd_buf; 4218 4219 if (bl->aux_set) 4220 dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; 4221 else 4222 dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_PWM; 4223 4224 if (bl->luminance_set) 4225 dpcd_buf |= DP_EDP_PANEL_LUMINANCE_CONTROL_ENABLE; 4226 4227 if (bl->pwmgen_bit_count) { 4228 ret = drm_dp_dpcd_write_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count); 4229 if (ret < 0) 4230 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n", 4231 aux->name, ret); 4232 } 4233 4234 if (bl->pwm_freq_pre_divider) { 4235 ret = drm_dp_dpcd_write_byte(aux, DP_EDP_BACKLIGHT_FREQ_SET, 4236 bl->pwm_freq_pre_divider); 4237 if (ret < 0) 4238 drm_dbg_kms(aux->drm_dev, 4239 "%s: Failed to write aux backlight frequency: %d\n", 4240 aux->name, ret); 4241 else 4242 dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; 4243 } 4244 4245 ret = drm_dp_dpcd_write_byte(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf); 4246 if (ret < 0) { 4247 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux backlight mode: %d\n", 4248 aux->name, ret); 4249 return ret < 0 ? ret : -EIO; 4250 } 4251 4252 ret = drm_edp_backlight_set_level(aux, bl, level); 4253 if (ret < 0) 4254 return ret; 4255 ret = drm_edp_backlight_set_enable(aux, bl, true); 4256 if (ret < 0) 4257 return ret; 4258 4259 return 0; 4260 } 4261 EXPORT_SYMBOL(drm_edp_backlight_enable); 4262 4263 /** 4264 * drm_edp_backlight_disable() - Disable an eDP backlight using DPCD, if supported 4265 * @aux: The DP AUX channel to use 4266 * @bl: Backlight capability info from drm_edp_backlight_init() 4267 * 4268 * This function handles disabling DPCD backlight controls on a panel over AUX. 4269 * 4270 * Note that certain panels do not support being enabled or disabled via DPCD, but instead require 4271 * that the driver handle enabling/disabling the panel through implementation-specific means using 4272 * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false, 4273 * this function becomes a no-op, and the driver is expected to handle powering the panel off using 4274 * the EDP_BL_PWR GPIO. 4275 * 4276 * Returns: %0 on success or no-op, negative error code on failure. 4277 */ 4278 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl) 4279 { 4280 int ret; 4281 4282 ret = drm_edp_backlight_set_enable(aux, bl, false); 4283 if (ret < 0) 4284 return ret; 4285 4286 return 0; 4287 } 4288 EXPORT_SYMBOL(drm_edp_backlight_disable); 4289 4290 static inline int 4291 drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 4292 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) 4293 { 4294 int fxp, fxp_min, fxp_max, fxp_actual, f = 1; 4295 int ret; 4296 u8 pn, pn_min, pn_max, bit_count; 4297 4298 if (!bl->aux_set) 4299 return 0; 4300 4301 ret = drm_dp_dpcd_read_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, &bit_count); 4302 if (ret < 0) { 4303 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap: %d\n", 4304 aux->name, ret); 4305 return -ENODEV; 4306 } 4307 4308 bit_count &= DP_EDP_PWMGEN_BIT_COUNT_MASK; 4309 4310 ret = drm_dp_dpcd_read_byte(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min); 4311 if (ret < 0) { 4312 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap min: %d\n", 4313 aux->name, ret); 4314 return -ENODEV; 4315 } 4316 pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; 4317 4318 ret = drm_dp_dpcd_read_byte(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max); 4319 if (ret < 0) { 4320 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap max: %d\n", 4321 aux->name, ret); 4322 return -ENODEV; 4323 } 4324 pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; 4325 4326 if (unlikely(pn_min > pn_max)) { 4327 drm_dbg_kms(aux->drm_dev, "%s: Invalid pwmgen bit count cap min/max returned: %d %d\n", 4328 aux->name, pn_min, pn_max); 4329 return -EINVAL; 4330 } 4331 4332 /* 4333 * Per VESA eDP Spec v1.4b, section 3.3.10.2: 4334 * If DP_EDP_PWMGEN_BIT_COUNT is less than DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, 4335 * the sink must use the MIN value as the effective PWM bit count. 4336 * Clamp the reported value to the [MIN, MAX] capability range to ensure 4337 * correct brightness scaling on compliant eDP panels. 4338 * Only enable this logic if the [MIN, MAX] range is valid in regard to Spec. 4339 */ 4340 pn = bit_count; 4341 if (bit_count < pn_min) 4342 pn = clamp(bit_count, pn_min, pn_max); 4343 4344 bl->max = (1 << pn) - 1; 4345 if (!driver_pwm_freq_hz) { 4346 if (pn != bit_count) 4347 goto bit_count_write_back; 4348 4349 return 0; 4350 } 4351 4352 /* 4353 * Set PWM Frequency divider to match desired frequency provided by the driver. 4354 * The PWM Frequency is calculated as 27Mhz / (F x P). 4355 * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the 4356 * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) 4357 * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the 4358 * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) 4359 */ 4360 4361 /* Find desired value of (F x P) 4362 * Note that, if F x P is out of supported range, the maximum value or minimum value will 4363 * applied automatically. So no need to check that. 4364 */ 4365 fxp = DIV_ROUND_CLOSEST(1000 * DP_EDP_BACKLIGHT_FREQ_BASE_KHZ, driver_pwm_freq_hz); 4366 4367 /* Use highest possible value of Pn for more granularity of brightness adjustment while 4368 * satisfying the conditions below. 4369 * - Pn is in the range of Pn_min and Pn_max 4370 * - F is in the range of 1 and 255 4371 * - FxP is within 25% of desired value. 4372 * Note: 25% is arbitrary value and may need some tweak. 4373 */ 4374 /* Ensure frequency is within 25% of desired value */ 4375 fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); 4376 fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); 4377 if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { 4378 drm_dbg_kms(aux->drm_dev, 4379 "%s: Driver defined backlight frequency (%d) out of range\n", 4380 aux->name, driver_pwm_freq_hz); 4381 return 0; 4382 } 4383 4384 for (pn = pn_max; pn >= pn_min; pn--) { 4385 f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); 4386 fxp_actual = f << pn; 4387 if (fxp_min <= fxp_actual && fxp_actual <= fxp_max) 4388 break; 4389 } 4390 4391 bit_count_write_back: 4392 ret = drm_dp_dpcd_write_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, pn); 4393 if (ret < 0) { 4394 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n", 4395 aux->name, ret); 4396 return 0; 4397 } 4398 4399 if (!driver_pwm_freq_hz) 4400 return 0; 4401 4402 bl->pwmgen_bit_count = pn; 4403 bl->max = (1 << pn) - 1; 4404 4405 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) { 4406 bl->pwm_freq_pre_divider = f; 4407 drm_dbg_kms(aux->drm_dev, "%s: Using backlight frequency from driver (%dHz)\n", 4408 aux->name, driver_pwm_freq_hz); 4409 } 4410 4411 return 0; 4412 } 4413 4414 static inline int 4415 drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 4416 u8 *current_mode) 4417 { 4418 int ret; 4419 u8 buf[3]; 4420 u8 mode_reg; 4421 4422 ret = drm_dp_dpcd_read_byte(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg); 4423 if (ret < 0) { 4424 drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight mode: %d\n", 4425 aux->name, ret); 4426 return ret < 0 ? ret : -EIO; 4427 } 4428 4429 *current_mode = (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK); 4430 if (!bl->aux_set) 4431 return 0; 4432 4433 if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { 4434 int size = 1 + bl->lsb_reg_used; 4435 4436 if (bl->luminance_set) { 4437 ret = drm_dp_dpcd_read_data(aux, DP_EDP_PANEL_TARGET_LUMINANCE_VALUE, 4438 buf, sizeof(buf)); 4439 if (ret < 0) { 4440 drm_dbg_kms(aux->drm_dev, 4441 "%s: Failed to read backlight level: %d\n", 4442 aux->name, ret); 4443 return ret; 4444 } 4445 4446 /* 4447 * Incase luminance is set we want to send the value back in nits but 4448 * since DP_EDP_PANEL_TARGET_LUMINANCE stores values in millinits we 4449 * need to divide by 1000. 4450 */ 4451 return (buf[0] | buf[1] << 8 | buf[2] << 16) / 1000; 4452 } else { 4453 ret = drm_dp_dpcd_read_data(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, 4454 buf, size); 4455 if (ret < 0) { 4456 drm_dbg_kms(aux->drm_dev, 4457 "%s: Failed to read backlight level: %d\n", 4458 aux->name, ret); 4459 return ret; 4460 } 4461 4462 if (bl->lsb_reg_used) 4463 return (buf[0] << 8) | buf[1]; 4464 else 4465 return buf[0]; 4466 } 4467 } 4468 4469 /* 4470 * If we're not in DPCD control mode yet, the programmed brightness value is meaningless and 4471 * the driver should assume max brightness 4472 */ 4473 return bl->max; 4474 } 4475 4476 /** 4477 * drm_edp_backlight_init() - Probe a display panel's TCON using the standard VESA eDP backlight 4478 * interface. 4479 * @aux: The DP aux device to use for probing 4480 * @bl: The &drm_edp_backlight_info struct to fill out with information on the backlight 4481 * @max_luminance: max luminance when need luminance is set as true 4482 * @driver_pwm_freq_hz: Optional PWM frequency from the driver in hz 4483 * @edp_dpcd: A cached copy of the eDP DPCD 4484 * @current_level: Where to store the probed brightness level, if any 4485 * @current_mode: Where to store the currently set backlight control mode 4486 * @need_luminance: Tells us if a we want to manipulate backlight using luminance values 4487 * 4488 * Initializes a &drm_edp_backlight_info struct by probing @aux for it's backlight capabilities, 4489 * along with also probing the current and maximum supported brightness levels. 4490 * 4491 * If @driver_pwm_freq_hz is non-zero, this will be used as the backlight frequency. Otherwise, the 4492 * default frequency from the panel is used. 4493 * 4494 * Returns: %0 on success, negative error code on failure. 4495 */ 4496 int 4497 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 4498 u32 max_luminance, 4499 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE], 4500 u32 *current_level, u8 *current_mode, bool need_luminance) 4501 { 4502 int ret; 4503 4504 if (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) 4505 bl->aux_enable = true; 4506 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) 4507 bl->aux_set = true; 4508 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) 4509 bl->lsb_reg_used = true; 4510 if ((edp_dpcd[0] & DP_EDP_15) && edp_dpcd[3] & 4511 (DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE) && need_luminance) 4512 bl->luminance_set = true; 4513 4514 /* Sanity check caps */ 4515 if (!bl->aux_set && !(edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP) && 4516 !bl->luminance_set) { 4517 drm_dbg_kms(aux->drm_dev, 4518 "%s: Panel does not support AUX, PWM or luminance-based brightness control. Aborting\n", 4519 aux->name); 4520 return -EINVAL; 4521 } 4522 4523 if (bl->luminance_set) { 4524 bl->max = max_luminance; 4525 } else { 4526 ret = drm_edp_backlight_probe_max(aux, bl, driver_pwm_freq_hz, edp_dpcd); 4527 if (ret < 0) 4528 return ret; 4529 } 4530 4531 ret = drm_edp_backlight_probe_state(aux, bl, current_mode); 4532 if (ret < 0) 4533 return ret; 4534 *current_level = ret; 4535 4536 drm_dbg_kms(aux->drm_dev, 4537 "%s: Found backlight: aux_set=%d aux_enable=%d mode=%d\n", 4538 aux->name, bl->aux_set, bl->aux_enable, *current_mode); 4539 if (bl->aux_set) { 4540 drm_dbg_kms(aux->drm_dev, 4541 "%s: Backlight caps: level=%d/%d pwm_freq_pre_divider=%d lsb_reg_used=%d\n", 4542 aux->name, *current_level, bl->max, bl->pwm_freq_pre_divider, 4543 bl->lsb_reg_used); 4544 } 4545 4546 return 0; 4547 } 4548 EXPORT_SYMBOL(drm_edp_backlight_init); 4549 4550 #if IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \ 4551 (IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)) 4552 4553 static int dp_aux_backlight_update_status(struct backlight_device *bd) 4554 { 4555 struct dp_aux_backlight *bl = bl_get_data(bd); 4556 u16 brightness = backlight_get_brightness(bd); 4557 int ret = 0; 4558 4559 if (!backlight_is_blank(bd)) { 4560 if (!bl->enabled) { 4561 drm_edp_backlight_enable(bl->aux, &bl->info, brightness); 4562 bl->enabled = true; 4563 return 0; 4564 } 4565 ret = drm_edp_backlight_set_level(bl->aux, &bl->info, brightness); 4566 } else { 4567 if (bl->enabled) { 4568 drm_edp_backlight_disable(bl->aux, &bl->info); 4569 bl->enabled = false; 4570 } 4571 } 4572 4573 return ret; 4574 } 4575 4576 static const struct backlight_ops dp_aux_bl_ops = { 4577 .update_status = dp_aux_backlight_update_status, 4578 }; 4579 4580 /** 4581 * drm_panel_dp_aux_backlight - create and use DP AUX backlight 4582 * @panel: DRM panel 4583 * @aux: The DP AUX channel to use 4584 * 4585 * Use this function to create and handle backlight if your panel 4586 * supports backlight control over DP AUX channel using DPCD 4587 * registers as per VESA's standard backlight control interface. 4588 * 4589 * When the panel is enabled backlight will be enabled after a 4590 * successful call to &drm_panel_funcs.enable() 4591 * 4592 * When the panel is disabled backlight will be disabled before the 4593 * call to &drm_panel_funcs.disable(). 4594 * 4595 * A typical implementation for a panel driver supporting backlight 4596 * control over DP AUX will call this function at probe time. 4597 * Backlight will then be handled transparently without requiring 4598 * any intervention from the driver. 4599 * 4600 * drm_panel_dp_aux_backlight() must be called after the call to drm_panel_init(). 4601 * 4602 * Return: 0 on success or a negative error code on failure. 4603 */ 4604 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux) 4605 { 4606 struct dp_aux_backlight *bl; 4607 struct backlight_properties props = { 0 }; 4608 u32 current_level; 4609 u8 current_mode; 4610 u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; 4611 int ret; 4612 4613 if (!panel || !panel->dev || !aux) 4614 return -EINVAL; 4615 4616 ret = drm_dp_dpcd_read_data(aux, DP_EDP_DPCD_REV, edp_dpcd, 4617 EDP_DISPLAY_CTL_CAP_SIZE); 4618 if (ret < 0) 4619 return ret; 4620 4621 if (!drm_edp_backlight_supported(edp_dpcd)) { 4622 DRM_DEV_INFO(panel->dev, "DP AUX backlight is not supported\n"); 4623 return 0; 4624 } 4625 4626 bl = devm_kzalloc(panel->dev, sizeof(*bl), GFP_KERNEL); 4627 if (!bl) 4628 return -ENOMEM; 4629 4630 bl->aux = aux; 4631 4632 ret = drm_edp_backlight_init(aux, &bl->info, 0, 0, edp_dpcd, 4633 ¤t_level, ¤t_mode, false); 4634 if (ret < 0) 4635 return ret; 4636 4637 props.type = BACKLIGHT_RAW; 4638 props.brightness = current_level; 4639 props.max_brightness = bl->info.max; 4640 4641 bl->base = devm_backlight_device_register(panel->dev, "dp_aux_backlight", 4642 panel->dev, bl, 4643 &dp_aux_bl_ops, &props); 4644 if (IS_ERR(bl->base)) 4645 return PTR_ERR(bl->base); 4646 4647 backlight_disable(bl->base); 4648 4649 panel->backlight = bl->base; 4650 4651 return 0; 4652 } 4653 EXPORT_SYMBOL(drm_panel_dp_aux_backlight); 4654 4655 #endif 4656 4657 /* See DP Standard v2.1 2.6.4.4.1.1, 2.8.4.4, 2.8.7 */ 4658 static int drm_dp_link_data_symbol_cycles(int lane_count, int pixels, 4659 int bpp_x16, int symbol_size, 4660 bool is_mst) 4661 { 4662 int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); 4663 int align = is_mst ? 4 / lane_count : 1; 4664 4665 return ALIGN(cycles, align); 4666 } 4667 4668 /** 4669 * drm_dp_link_symbol_cycles - calculate the link symbol count with/without dsc 4670 * @lane_count: DP link lane count 4671 * @pixels: number of pixels in a scanline 4672 * @dsc_slice_count: number of slices for DSC or '0' for non-DSC 4673 * @bpp_x16: bits per pixel in .4 binary fixed format 4674 * @symbol_size: DP symbol size 4675 * @is_mst: %true for MST and %false for SST 4676 * 4677 * Calculate the link symbol cycles for both DSC (@dsc_slice_count !=0) and 4678 * non-DSC case (@dsc_slice_count == 0) and return the count. 4679 */ 4680 int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count, 4681 int bpp_x16, int symbol_size, bool is_mst) 4682 { 4683 int slice_count = dsc_slice_count ? : 1; 4684 int slice_pixels = DIV_ROUND_UP(pixels, slice_count); 4685 int slice_data_cycles = drm_dp_link_data_symbol_cycles(lane_count, 4686 slice_pixels, 4687 bpp_x16, 4688 symbol_size, 4689 is_mst); 4690 int slice_eoc_cycles = 0; 4691 4692 if (dsc_slice_count) 4693 slice_eoc_cycles = is_mst ? 4 / lane_count : 1; 4694 4695 return slice_count * (slice_data_cycles + slice_eoc_cycles); 4696 } 4697 EXPORT_SYMBOL(drm_dp_link_symbol_cycles); 4698 4699 /** 4700 * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream 4701 * @lane_count: DP link lane count 4702 * @hactive: pixel count of the active period in one scanline of the stream 4703 * @dsc_slice_count: number of slices for DSC or '0' for non-DSC 4704 * @bpp_x16: bits per pixel in .4 binary fixed point 4705 * @flags: DRM_DP_OVERHEAD_x flags 4706 * 4707 * Calculate the BW allocation overhead of a DP link stream, depending 4708 * on the link's 4709 * - @lane_count 4710 * - SST/MST mode (@flags / %DRM_DP_OVERHEAD_MST) 4711 * - symbol size (@flags / %DRM_DP_OVERHEAD_UHBR) 4712 * - FEC mode (@flags / %DRM_DP_OVERHEAD_FEC) 4713 * - SSC/REF_CLK mode (@flags / %DRM_DP_OVERHEAD_SSC_REF_CLK) 4714 * as well as the stream's 4715 * - @hactive timing 4716 * - @bpp_x16 color depth 4717 * - compression mode (@dsc_slice_count != 0) 4718 * Note that this overhead doesn't account for the 8b/10b, 128b/132b 4719 * channel coding efficiency, for that see 4720 * @drm_dp_link_bw_channel_coding_efficiency(). 4721 * 4722 * Returns the overhead as 100% + overhead% in 1ppm units. 4723 */ 4724 int drm_dp_bw_overhead(int lane_count, int hactive, 4725 int dsc_slice_count, 4726 int bpp_x16, unsigned long flags) 4727 { 4728 int symbol_size = flags & DRM_DP_BW_OVERHEAD_UHBR ? 32 : 8; 4729 bool is_mst = flags & DRM_DP_BW_OVERHEAD_MST; 4730 u32 overhead = 1000000; 4731 int symbol_cycles; 4732 4733 if (lane_count == 0 || hactive == 0 || bpp_x16 == 0) { 4734 DRM_DEBUG_KMS("Invalid BW overhead params: lane_count %d, hactive %d, bpp_x16 " FXP_Q4_FMT "\n", 4735 lane_count, hactive, 4736 FXP_Q4_ARGS(bpp_x16)); 4737 return 0; 4738 } 4739 4740 /* 4741 * DP Standard v2.1 2.6.4.1 4742 * SSC downspread and ref clock variation margin: 4743 * 5300ppm + 300ppm ~ 0.6% 4744 */ 4745 if (flags & DRM_DP_BW_OVERHEAD_SSC_REF_CLK) 4746 overhead += 6000; 4747 4748 /* 4749 * DP Standard v2.1 2.6.4.1.1, 3.5.1.5.4: 4750 * FEC symbol insertions for 8b/10b channel coding: 4751 * After each 250 data symbols on 2-4 lanes: 4752 * 250 LL + 5 FEC_PARITY_PH + 1 CD_ADJ (256 byte FEC block) 4753 * After each 2 x 250 data symbols on 1 lane: 4754 * 2 * 250 LL + 11 FEC_PARITY_PH + 1 CD_ADJ (512 byte FEC block) 4755 * After 256 (2-4 lanes) or 128 (1 lane) FEC blocks: 4756 * 256 * 256 bytes + 1 FEC_PM 4757 * or 4758 * 128 * 512 bytes + 1 FEC_PM 4759 * (256 * 6 + 1) / (256 * 250) = 2.4015625 % 4760 */ 4761 if (flags & DRM_DP_BW_OVERHEAD_FEC) 4762 overhead += 24016; 4763 4764 /* 4765 * DP Standard v2.1 2.7.9, 5.9.7 4766 * The FEC overhead for UHBR is accounted for in its 96.71% channel 4767 * coding efficiency. 4768 */ 4769 WARN_ON((flags & DRM_DP_BW_OVERHEAD_UHBR) && 4770 (flags & DRM_DP_BW_OVERHEAD_FEC)); 4771 4772 symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, 4773 dsc_slice_count, 4774 bpp_x16, symbol_size, 4775 is_mst); 4776 4777 return DIV_ROUND_UP_ULL(mul_u32_u32(symbol_cycles * symbol_size * lane_count, 4778 overhead * 16), 4779 hactive * bpp_x16); 4780 } 4781 EXPORT_SYMBOL(drm_dp_bw_overhead); 4782 4783 /** 4784 * drm_dp_bw_channel_coding_efficiency - Get a DP link's channel coding efficiency 4785 * @is_uhbr: Whether the link has a 128b/132b channel coding 4786 * 4787 * Return the channel coding efficiency of the given DP link type, which is 4788 * either 8b/10b or 128b/132b (aka UHBR). The corresponding overhead includes 4789 * the 8b -> 10b, 128b -> 132b pixel data to link symbol conversion overhead 4790 * and for 128b/132b any link or PHY level control symbol insertion overhead 4791 * (LLCP, FEC, PHY sync, see DP Standard v2.1 3.5.2.18). For 8b/10b the 4792 * corresponding FEC overhead is BW allocation specific, included in the value 4793 * returned by drm_dp_bw_overhead(). 4794 * 4795 * Returns the efficiency in the 100%/coding-overhead% ratio in 4796 * 1ppm units. 4797 */ 4798 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr) 4799 { 4800 if (is_uhbr) 4801 return 967100; 4802 else 4803 /* 4804 * Note that on 8b/10b MST the efficiency is only 4805 * 78.75% due to the 1 out of 64 MTPH packet overhead, 4806 * not accounted for here. 4807 */ 4808 return 800000; 4809 } 4810 EXPORT_SYMBOL(drm_dp_bw_channel_coding_efficiency); 4811 4812 /** 4813 * drm_dp_max_dprx_data_rate - Get the max data bandwidth of a DPRX sink 4814 * @max_link_rate: max DPRX link rate in 10kbps units 4815 * @max_lanes: max DPRX lane count 4816 * 4817 * Given a link rate and lanes, get the data bandwidth. 4818 * 4819 * Data bandwidth is the actual payload rate, which depends on the data 4820 * bandwidth efficiency and the link rate. 4821 * 4822 * Note that protocol layers above the DPRX link level considered here can 4823 * further limit the maximum data rate. Such layers are the MST topology (with 4824 * limits on the link between the source and first branch device as well as on 4825 * the whole MST path until the DPRX link) and (Thunderbolt) DP tunnels - 4826 * which in turn can encapsulate an MST link with its own limit - with each 4827 * SST or MST encapsulated tunnel sharing the BW of a tunnel group. 4828 * 4829 * Returns the maximum data rate in kBps units. 4830 */ 4831 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes) 4832 { 4833 int ch_coding_efficiency = 4834 drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(max_link_rate)); 4835 4836 return DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate * 10 * max_lanes, 4837 ch_coding_efficiency), 4838 1000000 * 8); 4839 } 4840 EXPORT_SYMBOL(drm_dp_max_dprx_data_rate); 4841