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/errno.h> 26 #include <linux/i2c.h> 27 #include <linux/init.h> 28 #include <linux/kernel.h> 29 #include <linux/module.h> 30 #include <linux/sched.h> 31 #include <linux/seq_file.h> 32 #include <linux/string_helpers.h> 33 #include <linux/dynamic_debug.h> 34 35 #include <drm/display/drm_dp_helper.h> 36 #include <drm/display/drm_dp_mst_helper.h> 37 #include <drm/drm_edid.h> 38 #include <drm/drm_print.h> 39 #include <drm/drm_vblank.h> 40 #include <drm/drm_panel.h> 41 42 #include "drm_dp_helper_internal.h" 43 44 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0, 45 "DRM_UT_CORE", 46 "DRM_UT_DRIVER", 47 "DRM_UT_KMS", 48 "DRM_UT_PRIME", 49 "DRM_UT_ATOMIC", 50 "DRM_UT_VBL", 51 "DRM_UT_STATE", 52 "DRM_UT_LEASE", 53 "DRM_UT_DP", 54 "DRM_UT_DRMRES"); 55 56 struct dp_aux_backlight { 57 struct backlight_device *base; 58 struct drm_dp_aux *aux; 59 struct drm_edp_backlight_info info; 60 bool enabled; 61 }; 62 63 /** 64 * DOC: dp helpers 65 * 66 * These functions contain some common logic and helpers at various abstraction 67 * levels to deal with Display Port sink devices and related things like DP aux 68 * channel transfers, EDID reading over DP aux channels, decoding certain DPCD 69 * blocks, ... 70 */ 71 72 /* Helpers for DP link training */ 73 static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) 74 { 75 return link_status[r - DP_LANE0_1_STATUS]; 76 } 77 78 static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], 79 int lane) 80 { 81 int i = DP_LANE0_1_STATUS + (lane >> 1); 82 int s = (lane & 1) * 4; 83 u8 l = dp_link_status(link_status, i); 84 85 return (l >> s) & 0xf; 86 } 87 88 bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], 89 int lane_count) 90 { 91 u8 lane_align; 92 u8 lane_status; 93 int lane; 94 95 lane_align = dp_link_status(link_status, 96 DP_LANE_ALIGN_STATUS_UPDATED); 97 if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) 98 return false; 99 for (lane = 0; lane < lane_count; lane++) { 100 lane_status = dp_get_lane_status(link_status, lane); 101 if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) 102 return false; 103 } 104 return true; 105 } 106 EXPORT_SYMBOL(drm_dp_channel_eq_ok); 107 108 bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], 109 int lane_count) 110 { 111 int lane; 112 u8 lane_status; 113 114 for (lane = 0; lane < lane_count; lane++) { 115 lane_status = dp_get_lane_status(link_status, lane); 116 if ((lane_status & DP_LANE_CR_DONE) == 0) 117 return false; 118 } 119 return true; 120 } 121 EXPORT_SYMBOL(drm_dp_clock_recovery_ok); 122 123 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], 124 int lane) 125 { 126 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); 127 int s = ((lane & 1) ? 128 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : 129 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); 130 u8 l = dp_link_status(link_status, i); 131 132 return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; 133 } 134 EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage); 135 136 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], 137 int lane) 138 { 139 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); 140 int s = ((lane & 1) ? 141 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : 142 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); 143 u8 l = dp_link_status(link_status, i); 144 145 return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; 146 } 147 EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); 148 149 /* DP 2.0 128b/132b */ 150 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE], 151 int lane) 152 { 153 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); 154 int s = ((lane & 1) ? 155 DP_ADJUST_TX_FFE_PRESET_LANE1_SHIFT : 156 DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT); 157 u8 l = dp_link_status(link_status, i); 158 159 return (l >> s) & 0xf; 160 } 161 EXPORT_SYMBOL(drm_dp_get_adjust_tx_ffe_preset); 162 163 /* DP 2.0 errata for 128b/132b */ 164 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE], 165 int lane_count) 166 { 167 u8 lane_align, lane_status; 168 int lane; 169 170 lane_align = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 171 if (!(lane_align & DP_INTERLANE_ALIGN_DONE)) 172 return false; 173 174 for (lane = 0; lane < lane_count; lane++) { 175 lane_status = dp_get_lane_status(link_status, lane); 176 if (!(lane_status & DP_LANE_CHANNEL_EQ_DONE)) 177 return false; 178 } 179 return true; 180 } 181 EXPORT_SYMBOL(drm_dp_128b132b_lane_channel_eq_done); 182 183 /* DP 2.0 errata for 128b/132b */ 184 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE], 185 int lane_count) 186 { 187 u8 lane_status; 188 int lane; 189 190 for (lane = 0; lane < lane_count; lane++) { 191 lane_status = dp_get_lane_status(link_status, lane); 192 if (!(lane_status & DP_LANE_SYMBOL_LOCKED)) 193 return false; 194 } 195 return true; 196 } 197 EXPORT_SYMBOL(drm_dp_128b132b_lane_symbol_locked); 198 199 /* DP 2.0 errata for 128b/132b */ 200 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]) 201 { 202 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 203 204 return status & DP_128B132B_DPRX_EQ_INTERLANE_ALIGN_DONE; 205 } 206 EXPORT_SYMBOL(drm_dp_128b132b_eq_interlane_align_done); 207 208 /* DP 2.0 errata for 128b/132b */ 209 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]) 210 { 211 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 212 213 return status & DP_128B132B_DPRX_CDS_INTERLANE_ALIGN_DONE; 214 } 215 EXPORT_SYMBOL(drm_dp_128b132b_cds_interlane_align_done); 216 217 /* DP 2.0 errata for 128b/132b */ 218 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]) 219 { 220 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); 221 222 return status & DP_128B132B_LT_FAILED; 223 } 224 EXPORT_SYMBOL(drm_dp_128b132b_link_training_failed); 225 226 static int __8b10b_clock_recovery_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) 227 { 228 if (rd_interval > 4) 229 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", 230 aux->name, rd_interval); 231 232 if (rd_interval == 0) 233 return 100; 234 235 return rd_interval * 4 * USEC_PER_MSEC; 236 } 237 238 static int __8b10b_channel_eq_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 400; 246 247 return rd_interval * 4 * USEC_PER_MSEC; 248 } 249 250 static int __128b132b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) 251 { 252 switch (rd_interval) { 253 default: 254 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x\n", 255 aux->name, rd_interval); 256 fallthrough; 257 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_400_US: 258 return 400; 259 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_4_MS: 260 return 4000; 261 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_8_MS: 262 return 8000; 263 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_12_MS: 264 return 12000; 265 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_16_MS: 266 return 16000; 267 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_32_MS: 268 return 32000; 269 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_64_MS: 270 return 64000; 271 } 272 } 273 274 /* 275 * The link training delays are different for: 276 * 277 * - Clock recovery vs. channel equalization 278 * - DPRX vs. LTTPR 279 * - 128b/132b vs. 8b/10b 280 * - DPCD rev 1.3 vs. later 281 * 282 * Get the correct delay in us, reading DPCD if necessary. 283 */ 284 static int __read_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 285 enum drm_dp_phy dp_phy, bool uhbr, bool cr) 286 { 287 int (*parse)(const struct drm_dp_aux *aux, u8 rd_interval); 288 unsigned int offset; 289 u8 rd_interval, mask; 290 291 if (dp_phy == DP_PHY_DPRX) { 292 if (uhbr) { 293 if (cr) 294 return 100; 295 296 offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL; 297 mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 298 parse = __128b132b_channel_eq_delay_us; 299 } else { 300 if (cr && dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) 301 return 100; 302 303 offset = DP_TRAINING_AUX_RD_INTERVAL; 304 mask = DP_TRAINING_AUX_RD_MASK; 305 if (cr) 306 parse = __8b10b_clock_recovery_delay_us; 307 else 308 parse = __8b10b_channel_eq_delay_us; 309 } 310 } else { 311 if (uhbr) { 312 offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); 313 mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 314 parse = __128b132b_channel_eq_delay_us; 315 } else { 316 if (cr) 317 return 100; 318 319 offset = DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); 320 mask = DP_TRAINING_AUX_RD_MASK; 321 parse = __8b10b_channel_eq_delay_us; 322 } 323 } 324 325 if (offset < DP_RECEIVER_CAP_SIZE) { 326 rd_interval = dpcd[offset]; 327 } else { 328 if (drm_dp_dpcd_readb(aux, offset, &rd_interval) != 1) { 329 drm_dbg_kms(aux->drm_dev, "%s: failed rd interval read\n", 330 aux->name); 331 /* arbitrary default delay */ 332 return 400; 333 } 334 } 335 336 return parse(aux, rd_interval & mask); 337 } 338 339 int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 340 enum drm_dp_phy dp_phy, bool uhbr) 341 { 342 return __read_delay(aux, dpcd, dp_phy, uhbr, true); 343 } 344 EXPORT_SYMBOL(drm_dp_read_clock_recovery_delay); 345 346 int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 347 enum drm_dp_phy dp_phy, bool uhbr) 348 { 349 return __read_delay(aux, dpcd, dp_phy, uhbr, false); 350 } 351 EXPORT_SYMBOL(drm_dp_read_channel_eq_delay); 352 353 /* Per DP 2.0 Errata */ 354 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux) 355 { 356 int unit; 357 u8 val; 358 359 if (drm_dp_dpcd_readb(aux, DP_128B132B_TRAINING_AUX_RD_INTERVAL, &val) != 1) { 360 drm_err(aux->drm_dev, "%s: failed rd interval read\n", 361 aux->name); 362 /* default to max */ 363 val = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 364 } 365 366 unit = (val & DP_128B132B_TRAINING_AUX_RD_INTERVAL_1MS_UNIT) ? 1 : 2; 367 val &= DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; 368 369 return (val + 1) * unit * 1000; 370 } 371 EXPORT_SYMBOL(drm_dp_128b132b_read_aux_rd_interval); 372 373 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux, 374 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 375 { 376 u8 rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & 377 DP_TRAINING_AUX_RD_MASK; 378 int delay_us; 379 380 if (dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) 381 delay_us = 100; 382 else 383 delay_us = __8b10b_clock_recovery_delay_us(aux, rd_interval); 384 385 usleep_range(delay_us, delay_us * 2); 386 } 387 EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); 388 389 static void __drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 390 u8 rd_interval) 391 { 392 int delay_us = __8b10b_channel_eq_delay_us(aux, rd_interval); 393 394 usleep_range(delay_us, delay_us * 2); 395 } 396 397 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 398 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 399 { 400 __drm_dp_link_train_channel_eq_delay(aux, 401 dpcd[DP_TRAINING_AUX_RD_INTERVAL] & 402 DP_TRAINING_AUX_RD_MASK); 403 } 404 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); 405 406 /** 407 * drm_dp_phy_name() - Get the name of the given DP PHY 408 * @dp_phy: The DP PHY identifier 409 * 410 * Given the @dp_phy, get a user friendly name of the DP PHY, either "DPRX" or 411 * "LTTPR <N>", or "<INVALID DP PHY>" on errors. The returned string is always 412 * non-NULL and valid. 413 * 414 * Returns: Name of the DP PHY. 415 */ 416 const char *drm_dp_phy_name(enum drm_dp_phy dp_phy) 417 { 418 static const char * const phy_names[] = { 419 [DP_PHY_DPRX] = "DPRX", 420 [DP_PHY_LTTPR1] = "LTTPR 1", 421 [DP_PHY_LTTPR2] = "LTTPR 2", 422 [DP_PHY_LTTPR3] = "LTTPR 3", 423 [DP_PHY_LTTPR4] = "LTTPR 4", 424 [DP_PHY_LTTPR5] = "LTTPR 5", 425 [DP_PHY_LTTPR6] = "LTTPR 6", 426 [DP_PHY_LTTPR7] = "LTTPR 7", 427 [DP_PHY_LTTPR8] = "LTTPR 8", 428 }; 429 430 if (dp_phy < 0 || dp_phy >= ARRAY_SIZE(phy_names) || 431 WARN_ON(!phy_names[dp_phy])) 432 return "<INVALID DP PHY>"; 433 434 return phy_names[dp_phy]; 435 } 436 EXPORT_SYMBOL(drm_dp_phy_name); 437 438 void drm_dp_lttpr_link_train_clock_recovery_delay(void) 439 { 440 usleep_range(100, 200); 441 } 442 EXPORT_SYMBOL(drm_dp_lttpr_link_train_clock_recovery_delay); 443 444 static u8 dp_lttpr_phy_cap(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE], int r) 445 { 446 return phy_cap[r - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1]; 447 } 448 449 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 450 const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE]) 451 { 452 u8 interval = dp_lttpr_phy_cap(phy_cap, 453 DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) & 454 DP_TRAINING_AUX_RD_MASK; 455 456 __drm_dp_link_train_channel_eq_delay(aux, interval); 457 } 458 EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); 459 460 u8 drm_dp_link_rate_to_bw_code(int link_rate) 461 { 462 switch (link_rate) { 463 case 1000000: 464 return DP_LINK_BW_10; 465 case 1350000: 466 return DP_LINK_BW_13_5; 467 case 2000000: 468 return DP_LINK_BW_20; 469 default: 470 /* Spec says link_bw = link_rate / 0.27Gbps */ 471 return link_rate / 27000; 472 } 473 } 474 EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); 475 476 int drm_dp_bw_code_to_link_rate(u8 link_bw) 477 { 478 switch (link_bw) { 479 case DP_LINK_BW_10: 480 return 1000000; 481 case DP_LINK_BW_13_5: 482 return 1350000; 483 case DP_LINK_BW_20: 484 return 2000000; 485 default: 486 /* Spec says link_rate = link_bw * 0.27Gbps */ 487 return link_bw * 27000; 488 } 489 } 490 EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); 491 492 #define AUX_RETRY_INTERVAL 500 /* us */ 493 494 static inline void 495 drm_dp_dump_access(const struct drm_dp_aux *aux, 496 u8 request, uint offset, void *buffer, int ret) 497 { 498 const char *arrow = request == DP_AUX_NATIVE_READ ? "->" : "<-"; 499 500 if (ret > 0) 501 drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d) %*ph\n", 502 aux->name, offset, arrow, ret, min(ret, 20), buffer); 503 else 504 drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d)\n", 505 aux->name, offset, arrow, ret); 506 } 507 508 /** 509 * DOC: dp helpers 510 * 511 * The DisplayPort AUX channel is an abstraction to allow generic, driver- 512 * independent access to AUX functionality. Drivers can take advantage of 513 * this by filling in the fields of the drm_dp_aux structure. 514 * 515 * Transactions are described using a hardware-independent drm_dp_aux_msg 516 * structure, which is passed into a driver's .transfer() implementation. 517 * Both native and I2C-over-AUX transactions are supported. 518 */ 519 520 static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, 521 unsigned int offset, void *buffer, size_t size) 522 { 523 struct drm_dp_aux_msg msg; 524 unsigned int retry, native_reply; 525 int err = 0, ret = 0; 526 527 memset(&msg, 0, sizeof(msg)); 528 msg.address = offset; 529 msg.request = request; 530 msg.buffer = buffer; 531 msg.size = size; 532 533 mutex_lock(&aux->hw_mutex); 534 535 /* 536 * If the device attached to the aux bus is powered down then there's 537 * no reason to attempt a transfer. Error out immediately. 538 */ 539 if (aux->powered_down) { 540 ret = -EBUSY; 541 goto unlock; 542 } 543 544 /* 545 * The specification doesn't give any recommendation on how often to 546 * retry native transactions. We used to retry 7 times like for 547 * aux i2c transactions but real world devices this wasn't 548 * sufficient, bump to 32 which makes Dell 4k monitors happier. 549 */ 550 for (retry = 0; retry < 32; retry++) { 551 if (ret != 0 && ret != -ETIMEDOUT) { 552 usleep_range(AUX_RETRY_INTERVAL, 553 AUX_RETRY_INTERVAL + 100); 554 } 555 556 ret = aux->transfer(aux, &msg); 557 if (ret >= 0) { 558 native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK; 559 if (native_reply == DP_AUX_NATIVE_REPLY_ACK) { 560 if (ret == size) 561 goto unlock; 562 563 ret = -EPROTO; 564 } else 565 ret = -EIO; 566 } 567 568 /* 569 * We want the error we return to be the error we received on 570 * the first transaction, since we may get a different error the 571 * next time we retry 572 */ 573 if (!err) 574 err = ret; 575 } 576 577 drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up. First error: %d\n", 578 aux->name, err); 579 ret = err; 580 581 unlock: 582 mutex_unlock(&aux->hw_mutex); 583 return ret; 584 } 585 586 /** 587 * drm_dp_dpcd_probe() - probe a given DPCD address with a 1-byte read access 588 * @aux: DisplayPort AUX channel (SST) 589 * @offset: address of the register to probe 590 * 591 * Probe the provided DPCD address by reading 1 byte from it. The function can 592 * be used to trigger some side-effect the read access has, like waking up the 593 * sink, without the need for the read-out value. 594 * 595 * Returns 0 if the read access suceeded, or a negative error code on failure. 596 */ 597 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset) 598 { 599 u8 buffer; 600 int ret; 601 602 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, 1); 603 WARN_ON(ret == 0); 604 605 drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, ret); 606 607 return ret < 0 ? ret : 0; 608 } 609 EXPORT_SYMBOL(drm_dp_dpcd_probe); 610 611 /** 612 * drm_dp_dpcd_set_powered() - Set whether the DP device is powered 613 * @aux: DisplayPort AUX channel; for convenience it's OK to pass NULL here 614 * and the function will be a no-op. 615 * @powered: true if powered; false if not 616 * 617 * If the endpoint device on the DP AUX bus is known to be powered down 618 * then this function can be called to make future transfers fail immediately 619 * instead of needing to time out. 620 * 621 * If this function is never called then a device defaults to being powered. 622 */ 623 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered) 624 { 625 if (!aux) 626 return; 627 628 mutex_lock(&aux->hw_mutex); 629 aux->powered_down = !powered; 630 mutex_unlock(&aux->hw_mutex); 631 } 632 EXPORT_SYMBOL(drm_dp_dpcd_set_powered); 633 634 /** 635 * drm_dp_dpcd_read() - read a series of bytes from the DPCD 636 * @aux: DisplayPort AUX channel (SST or MST) 637 * @offset: address of the (first) register to read 638 * @buffer: buffer to store the register values 639 * @size: number of bytes in @buffer 640 * 641 * Returns the number of bytes transferred on success, or a negative error 642 * code on failure. -EIO is returned if the request was NAKed by the sink or 643 * if the retry count was exceeded. If not all bytes were transferred, this 644 * function returns -EPROTO. Errors from the underlying AUX channel transfer 645 * function, with the exception of -EBUSY (which causes the transaction to 646 * be retried), are propagated to the caller. 647 */ 648 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, 649 void *buffer, size_t size) 650 { 651 int ret; 652 653 /* 654 * HP ZR24w corrupts the first DPCD access after entering power save 655 * mode. Eg. on a read, the entire buffer will be filled with the same 656 * byte. Do a throw away read to avoid corrupting anything we care 657 * about. Afterwards things will work correctly until the monitor 658 * gets woken up and subsequently re-enters power save mode. 659 * 660 * The user pressing any button on the monitor is enough to wake it 661 * up, so there is no particularly good place to do the workaround. 662 * We just have to do it before any DPCD access and hope that the 663 * monitor doesn't power down exactly after the throw away read. 664 */ 665 if (!aux->is_remote) { 666 ret = drm_dp_dpcd_probe(aux, DP_DPCD_REV); 667 if (ret < 0) 668 return ret; 669 } 670 671 if (aux->is_remote) 672 ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size); 673 else 674 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, 675 buffer, size); 676 677 drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret); 678 return ret; 679 } 680 EXPORT_SYMBOL(drm_dp_dpcd_read); 681 682 /** 683 * drm_dp_dpcd_write() - write a series of bytes to the DPCD 684 * @aux: DisplayPort AUX channel (SST or MST) 685 * @offset: address of the (first) register to write 686 * @buffer: buffer containing the values to write 687 * @size: number of bytes in @buffer 688 * 689 * Returns the number of bytes transferred on success, or a negative error 690 * code on failure. -EIO is returned if the request was NAKed by the sink or 691 * if the retry count was exceeded. If not all bytes were transferred, this 692 * function returns -EPROTO. Errors from the underlying AUX channel transfer 693 * function, with the exception of -EBUSY (which causes the transaction to 694 * be retried), are propagated to the caller. 695 */ 696 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, 697 void *buffer, size_t size) 698 { 699 int ret; 700 701 if (aux->is_remote) 702 ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size); 703 else 704 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, 705 buffer, size); 706 707 drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret); 708 return ret; 709 } 710 EXPORT_SYMBOL(drm_dp_dpcd_write); 711 712 /** 713 * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) 714 * @aux: DisplayPort AUX channel 715 * @status: buffer to store the link status in (must be at least 6 bytes) 716 * 717 * Returns the number of bytes transferred on success or a negative error 718 * code on failure. 719 */ 720 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, 721 u8 status[DP_LINK_STATUS_SIZE]) 722 { 723 return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status, 724 DP_LINK_STATUS_SIZE); 725 } 726 EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); 727 728 /** 729 * drm_dp_dpcd_read_phy_link_status - get the link status information for a DP PHY 730 * @aux: DisplayPort AUX channel 731 * @dp_phy: the DP PHY to get the link status for 732 * @link_status: buffer to return the status in 733 * 734 * Fetch the AUX DPCD registers for the DPRX or an LTTPR PHY link status. The 735 * layout of the returned @link_status matches the DPCD register layout of the 736 * DPRX PHY link status. 737 * 738 * Returns 0 if the information was read successfully or a negative error code 739 * on failure. 740 */ 741 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, 742 enum drm_dp_phy dp_phy, 743 u8 link_status[DP_LINK_STATUS_SIZE]) 744 { 745 int ret; 746 747 if (dp_phy == DP_PHY_DPRX) { 748 ret = drm_dp_dpcd_read(aux, 749 DP_LANE0_1_STATUS, 750 link_status, 751 DP_LINK_STATUS_SIZE); 752 753 if (ret < 0) 754 return ret; 755 756 WARN_ON(ret != DP_LINK_STATUS_SIZE); 757 758 return 0; 759 } 760 761 ret = drm_dp_dpcd_read(aux, 762 DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy), 763 link_status, 764 DP_LINK_STATUS_SIZE - 1); 765 766 if (ret < 0) 767 return ret; 768 769 WARN_ON(ret != DP_LINK_STATUS_SIZE - 1); 770 771 /* Convert the LTTPR to the sink PHY link status layout */ 772 memmove(&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS + 1], 773 &link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS], 774 DP_LINK_STATUS_SIZE - (DP_SINK_STATUS - DP_LANE0_1_STATUS) - 1); 775 link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS] = 0; 776 777 return 0; 778 } 779 EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); 780 781 static bool is_edid_digital_input_dp(const struct drm_edid *drm_edid) 782 { 783 /* FIXME: get rid of drm_edid_raw() */ 784 const struct edid *edid = drm_edid_raw(drm_edid); 785 786 return edid && edid->revision >= 4 && 787 edid->input & DRM_EDID_INPUT_DIGITAL && 788 (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP; 789 } 790 791 /** 792 * drm_dp_downstream_is_type() - is the downstream facing port of certain type? 793 * @dpcd: DisplayPort configuration data 794 * @port_cap: port capabilities 795 * @type: port type to be checked. Can be: 796 * %DP_DS_PORT_TYPE_DP, %DP_DS_PORT_TYPE_VGA, %DP_DS_PORT_TYPE_DVI, 797 * %DP_DS_PORT_TYPE_HDMI, %DP_DS_PORT_TYPE_NON_EDID, 798 * %DP_DS_PORT_TYPE_DP_DUALMODE or %DP_DS_PORT_TYPE_WIRELESS. 799 * 800 * Caveat: Only works with DPCD 1.1+ port caps. 801 * 802 * Returns: whether the downstream facing port matches the type. 803 */ 804 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 805 const u8 port_cap[4], u8 type) 806 { 807 return drm_dp_is_branch(dpcd) && 808 dpcd[DP_DPCD_REV] >= 0x11 && 809 (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type; 810 } 811 EXPORT_SYMBOL(drm_dp_downstream_is_type); 812 813 /** 814 * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS? 815 * @dpcd: DisplayPort configuration data 816 * @port_cap: port capabilities 817 * @drm_edid: EDID 818 * 819 * Returns: whether the downstream facing port is TMDS (HDMI/DVI). 820 */ 821 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 822 const u8 port_cap[4], 823 const struct drm_edid *drm_edid) 824 { 825 if (dpcd[DP_DPCD_REV] < 0x11) { 826 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 827 case DP_DWN_STRM_PORT_TYPE_TMDS: 828 return true; 829 default: 830 return false; 831 } 832 } 833 834 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 835 case DP_DS_PORT_TYPE_DP_DUALMODE: 836 if (is_edid_digital_input_dp(drm_edid)) 837 return false; 838 fallthrough; 839 case DP_DS_PORT_TYPE_DVI: 840 case DP_DS_PORT_TYPE_HDMI: 841 return true; 842 default: 843 return false; 844 } 845 } 846 EXPORT_SYMBOL(drm_dp_downstream_is_tmds); 847 848 /** 849 * drm_dp_send_real_edid_checksum() - send back real edid checksum value 850 * @aux: DisplayPort AUX channel 851 * @real_edid_checksum: real edid checksum for the last block 852 * 853 * Returns: 854 * True on success 855 */ 856 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, 857 u8 real_edid_checksum) 858 { 859 u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0; 860 861 if (drm_dp_dpcd_read(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, 862 &auto_test_req, 1) < 1) { 863 drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n", 864 aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); 865 return false; 866 } 867 auto_test_req &= DP_AUTOMATED_TEST_REQUEST; 868 869 if (drm_dp_dpcd_read(aux, DP_TEST_REQUEST, &link_edid_read, 1) < 1) { 870 drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n", 871 aux->name, DP_TEST_REQUEST); 872 return false; 873 } 874 link_edid_read &= DP_TEST_LINK_EDID_READ; 875 876 if (!auto_test_req || !link_edid_read) { 877 drm_dbg_kms(aux->drm_dev, "%s: Source DUT does not support TEST_EDID_READ\n", 878 aux->name); 879 return false; 880 } 881 882 if (drm_dp_dpcd_write(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, 883 &auto_test_req, 1) < 1) { 884 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", 885 aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); 886 return false; 887 } 888 889 /* send back checksum for the last edid extension block data */ 890 if (drm_dp_dpcd_write(aux, DP_TEST_EDID_CHECKSUM, 891 &real_edid_checksum, 1) < 1) { 892 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", 893 aux->name, DP_TEST_EDID_CHECKSUM); 894 return false; 895 } 896 897 test_resp |= DP_TEST_EDID_CHECKSUM_WRITE; 898 if (drm_dp_dpcd_write(aux, DP_TEST_RESPONSE, &test_resp, 1) < 1) { 899 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", 900 aux->name, DP_TEST_RESPONSE); 901 return false; 902 } 903 904 return true; 905 } 906 EXPORT_SYMBOL(drm_dp_send_real_edid_checksum); 907 908 static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 909 { 910 u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK; 911 912 if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4) 913 port_count = 4; 914 915 return port_count; 916 } 917 918 static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, 919 u8 dpcd[DP_RECEIVER_CAP_SIZE]) 920 { 921 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 922 int ret; 923 924 /* 925 * Prior to DP1.3 the bit represented by 926 * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. 927 * If it is set DP_DPCD_REV at 0000h could be at a value less than 928 * the true capability of the panel. The only way to check is to 929 * then compare 0000h and 2200h. 930 */ 931 if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & 932 DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) 933 return 0; 934 935 ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext, 936 sizeof(dpcd_ext)); 937 if (ret < 0) 938 return ret; 939 if (ret != sizeof(dpcd_ext)) 940 return -EIO; 941 942 if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { 943 drm_dbg_kms(aux->drm_dev, 944 "%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n", 945 aux->name, dpcd[DP_DPCD_REV], dpcd_ext[DP_DPCD_REV]); 946 return 0; 947 } 948 949 if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext))) 950 return 0; 951 952 drm_dbg_kms(aux->drm_dev, "%s: Base DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd); 953 954 memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext)); 955 956 return 0; 957 } 958 959 /** 960 * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if 961 * available 962 * @aux: DisplayPort AUX channel 963 * @dpcd: Buffer to store the resulting DPCD in 964 * 965 * Attempts to read the base DPCD caps for @aux. Additionally, this function 966 * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if 967 * present. 968 * 969 * Returns: %0 if the DPCD was read successfully, negative error code 970 * otherwise. 971 */ 972 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, 973 u8 dpcd[DP_RECEIVER_CAP_SIZE]) 974 { 975 int ret; 976 977 ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); 978 if (ret < 0) 979 return ret; 980 if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0) 981 return -EIO; 982 983 ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); 984 if (ret < 0) 985 return ret; 986 987 drm_dbg_kms(aux->drm_dev, "%s: DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd); 988 989 return ret; 990 } 991 EXPORT_SYMBOL(drm_dp_read_dpcd_caps); 992 993 /** 994 * drm_dp_read_downstream_info() - read DPCD downstream port info if available 995 * @aux: DisplayPort AUX channel 996 * @dpcd: A cached copy of the port's DPCD 997 * @downstream_ports: buffer to store the downstream port info in 998 * 999 * See also: 1000 * drm_dp_downstream_max_clock() 1001 * drm_dp_downstream_max_bpc() 1002 * 1003 * Returns: 0 if either the downstream port info was read successfully or 1004 * there was no downstream info to read, or a negative error code otherwise. 1005 */ 1006 int drm_dp_read_downstream_info(struct drm_dp_aux *aux, 1007 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1008 u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]) 1009 { 1010 int ret; 1011 u8 len; 1012 1013 memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS); 1014 1015 /* No downstream info to read */ 1016 if (!drm_dp_is_branch(dpcd) || dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) 1017 return 0; 1018 1019 /* Some branches advertise having 0 downstream ports, despite also advertising they have a 1020 * downstream port present. The DP spec isn't clear on if this is allowed or not, but since 1021 * some branches do it we need to handle it regardless. 1022 */ 1023 len = drm_dp_downstream_port_count(dpcd); 1024 if (!len) 1025 return 0; 1026 1027 if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) 1028 len *= 4; 1029 1030 ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); 1031 if (ret < 0) 1032 return ret; 1033 if (ret != len) 1034 return -EIO; 1035 1036 drm_dbg_kms(aux->drm_dev, "%s: DPCD DFP: %*ph\n", aux->name, len, downstream_ports); 1037 1038 return 0; 1039 } 1040 EXPORT_SYMBOL(drm_dp_read_downstream_info); 1041 1042 /** 1043 * drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock 1044 * @dpcd: DisplayPort configuration data 1045 * @port_cap: port capabilities 1046 * 1047 * Returns: Downstream facing port max dot clock in kHz on success, 1048 * or 0 if max clock not defined 1049 */ 1050 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1051 const u8 port_cap[4]) 1052 { 1053 if (!drm_dp_is_branch(dpcd)) 1054 return 0; 1055 1056 if (dpcd[DP_DPCD_REV] < 0x11) 1057 return 0; 1058 1059 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1060 case DP_DS_PORT_TYPE_VGA: 1061 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1062 return 0; 1063 return port_cap[1] * 8000; 1064 default: 1065 return 0; 1066 } 1067 } 1068 EXPORT_SYMBOL(drm_dp_downstream_max_dotclock); 1069 1070 /** 1071 * drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock 1072 * @dpcd: DisplayPort configuration data 1073 * @port_cap: port capabilities 1074 * @drm_edid: EDID 1075 * 1076 * Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success, 1077 * or 0 if max TMDS clock not defined 1078 */ 1079 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1080 const u8 port_cap[4], 1081 const struct drm_edid *drm_edid) 1082 { 1083 if (!drm_dp_is_branch(dpcd)) 1084 return 0; 1085 1086 if (dpcd[DP_DPCD_REV] < 0x11) { 1087 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1088 case DP_DWN_STRM_PORT_TYPE_TMDS: 1089 return 165000; 1090 default: 1091 return 0; 1092 } 1093 } 1094 1095 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1096 case DP_DS_PORT_TYPE_DP_DUALMODE: 1097 if (is_edid_digital_input_dp(drm_edid)) 1098 return 0; 1099 /* 1100 * It's left up to the driver to check the 1101 * DP dual mode adapter's max TMDS clock. 1102 * 1103 * Unfortunately it looks like branch devices 1104 * may not fordward that the DP dual mode i2c 1105 * access so we just usually get i2c nak :( 1106 */ 1107 fallthrough; 1108 case DP_DS_PORT_TYPE_HDMI: 1109 /* 1110 * We should perhaps assume 165 MHz when detailed cap 1111 * info is not available. But looks like many typical 1112 * branch devices fall into that category and so we'd 1113 * probably end up with users complaining that they can't 1114 * get high resolution modes with their favorite dongle. 1115 * 1116 * So let's limit to 300 MHz instead since DPCD 1.4 1117 * HDMI 2.0 DFPs are required to have the detailed cap 1118 * info. So it's more likely we're dealing with a HDMI 1.4 1119 * compatible* device here. 1120 */ 1121 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1122 return 300000; 1123 return port_cap[1] * 2500; 1124 case DP_DS_PORT_TYPE_DVI: 1125 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1126 return 165000; 1127 /* FIXME what to do about DVI dual link? */ 1128 return port_cap[1] * 2500; 1129 default: 1130 return 0; 1131 } 1132 } 1133 EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock); 1134 1135 /** 1136 * drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock 1137 * @dpcd: DisplayPort configuration data 1138 * @port_cap: port capabilities 1139 * @drm_edid: EDID 1140 * 1141 * Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success, 1142 * or 0 if max TMDS clock not defined 1143 */ 1144 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1145 const u8 port_cap[4], 1146 const struct drm_edid *drm_edid) 1147 { 1148 if (!drm_dp_is_branch(dpcd)) 1149 return 0; 1150 1151 if (dpcd[DP_DPCD_REV] < 0x11) { 1152 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1153 case DP_DWN_STRM_PORT_TYPE_TMDS: 1154 return 25000; 1155 default: 1156 return 0; 1157 } 1158 } 1159 1160 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1161 case DP_DS_PORT_TYPE_DP_DUALMODE: 1162 if (is_edid_digital_input_dp(drm_edid)) 1163 return 0; 1164 fallthrough; 1165 case DP_DS_PORT_TYPE_DVI: 1166 case DP_DS_PORT_TYPE_HDMI: 1167 /* 1168 * Unclear whether the protocol converter could 1169 * utilize pixel replication. Assume it won't. 1170 */ 1171 return 25000; 1172 default: 1173 return 0; 1174 } 1175 } 1176 EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock); 1177 1178 /** 1179 * drm_dp_downstream_max_bpc() - extract downstream facing port max 1180 * bits per component 1181 * @dpcd: DisplayPort configuration data 1182 * @port_cap: downstream facing port capabilities 1183 * @drm_edid: EDID 1184 * 1185 * Returns: Max bpc on success or 0 if max bpc not defined 1186 */ 1187 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1188 const u8 port_cap[4], 1189 const struct drm_edid *drm_edid) 1190 { 1191 if (!drm_dp_is_branch(dpcd)) 1192 return 0; 1193 1194 if (dpcd[DP_DPCD_REV] < 0x11) { 1195 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { 1196 case DP_DWN_STRM_PORT_TYPE_DP: 1197 return 0; 1198 default: 1199 return 8; 1200 } 1201 } 1202 1203 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1204 case DP_DS_PORT_TYPE_DP: 1205 return 0; 1206 case DP_DS_PORT_TYPE_DP_DUALMODE: 1207 if (is_edid_digital_input_dp(drm_edid)) 1208 return 0; 1209 fallthrough; 1210 case DP_DS_PORT_TYPE_HDMI: 1211 case DP_DS_PORT_TYPE_DVI: 1212 case DP_DS_PORT_TYPE_VGA: 1213 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1214 return 8; 1215 1216 switch (port_cap[2] & DP_DS_MAX_BPC_MASK) { 1217 case DP_DS_8BPC: 1218 return 8; 1219 case DP_DS_10BPC: 1220 return 10; 1221 case DP_DS_12BPC: 1222 return 12; 1223 case DP_DS_16BPC: 1224 return 16; 1225 default: 1226 return 8; 1227 } 1228 break; 1229 default: 1230 return 8; 1231 } 1232 } 1233 EXPORT_SYMBOL(drm_dp_downstream_max_bpc); 1234 1235 /** 1236 * drm_dp_downstream_420_passthrough() - determine downstream facing port 1237 * YCbCr 4:2:0 pass-through capability 1238 * @dpcd: DisplayPort configuration data 1239 * @port_cap: downstream facing port capabilities 1240 * 1241 * Returns: whether the downstream facing port can pass through YCbCr 4:2:0 1242 */ 1243 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1244 const u8 port_cap[4]) 1245 { 1246 if (!drm_dp_is_branch(dpcd)) 1247 return false; 1248 1249 if (dpcd[DP_DPCD_REV] < 0x13) 1250 return false; 1251 1252 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1253 case DP_DS_PORT_TYPE_DP: 1254 return true; 1255 case DP_DS_PORT_TYPE_HDMI: 1256 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1257 return false; 1258 1259 return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH; 1260 default: 1261 return false; 1262 } 1263 } 1264 EXPORT_SYMBOL(drm_dp_downstream_420_passthrough); 1265 1266 /** 1267 * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port 1268 * YCbCr 4:4:4->4:2:0 conversion capability 1269 * @dpcd: DisplayPort configuration data 1270 * @port_cap: downstream facing port capabilities 1271 * 1272 * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0 1273 */ 1274 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1275 const u8 port_cap[4]) 1276 { 1277 if (!drm_dp_is_branch(dpcd)) 1278 return false; 1279 1280 if (dpcd[DP_DPCD_REV] < 0x13) 1281 return false; 1282 1283 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1284 case DP_DS_PORT_TYPE_HDMI: 1285 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1286 return false; 1287 1288 return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV; 1289 default: 1290 return false; 1291 } 1292 } 1293 EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); 1294 1295 /** 1296 * drm_dp_downstream_rgb_to_ycbcr_conversion() - determine downstream facing port 1297 * RGB->YCbCr conversion capability 1298 * @dpcd: DisplayPort configuration data 1299 * @port_cap: downstream facing port capabilities 1300 * @color_spc: Colorspace for which conversion cap is sought 1301 * 1302 * Returns: whether the downstream facing port can convert RGB->YCbCr for a given 1303 * colorspace. 1304 */ 1305 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1306 const u8 port_cap[4], 1307 u8 color_spc) 1308 { 1309 if (!drm_dp_is_branch(dpcd)) 1310 return false; 1311 1312 if (dpcd[DP_DPCD_REV] < 0x13) 1313 return false; 1314 1315 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1316 case DP_DS_PORT_TYPE_HDMI: 1317 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) 1318 return false; 1319 1320 return port_cap[3] & color_spc; 1321 default: 1322 return false; 1323 } 1324 } 1325 EXPORT_SYMBOL(drm_dp_downstream_rgb_to_ycbcr_conversion); 1326 1327 /** 1328 * drm_dp_downstream_mode() - return a mode for downstream facing port 1329 * @dev: DRM device 1330 * @dpcd: DisplayPort configuration data 1331 * @port_cap: port capabilities 1332 * 1333 * Provides a suitable mode for downstream facing ports without EDID. 1334 * 1335 * Returns: A new drm_display_mode on success or NULL on failure 1336 */ 1337 struct drm_display_mode * 1338 drm_dp_downstream_mode(struct drm_device *dev, 1339 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1340 const u8 port_cap[4]) 1341 1342 { 1343 u8 vic; 1344 1345 if (!drm_dp_is_branch(dpcd)) 1346 return NULL; 1347 1348 if (dpcd[DP_DPCD_REV] < 0x11) 1349 return NULL; 1350 1351 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { 1352 case DP_DS_PORT_TYPE_NON_EDID: 1353 switch (port_cap[0] & DP_DS_NON_EDID_MASK) { 1354 case DP_DS_NON_EDID_720x480i_60: 1355 vic = 6; 1356 break; 1357 case DP_DS_NON_EDID_720x480i_50: 1358 vic = 21; 1359 break; 1360 case DP_DS_NON_EDID_1920x1080i_60: 1361 vic = 5; 1362 break; 1363 case DP_DS_NON_EDID_1920x1080i_50: 1364 vic = 20; 1365 break; 1366 case DP_DS_NON_EDID_1280x720_60: 1367 vic = 4; 1368 break; 1369 case DP_DS_NON_EDID_1280x720_50: 1370 vic = 19; 1371 break; 1372 default: 1373 return NULL; 1374 } 1375 return drm_display_mode_from_cea_vic(dev, vic); 1376 default: 1377 return NULL; 1378 } 1379 } 1380 EXPORT_SYMBOL(drm_dp_downstream_mode); 1381 1382 /** 1383 * drm_dp_downstream_id() - identify branch device 1384 * @aux: DisplayPort AUX channel 1385 * @id: DisplayPort branch device id 1386 * 1387 * Returns branch device id on success or NULL on failure 1388 */ 1389 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]) 1390 { 1391 return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6); 1392 } 1393 EXPORT_SYMBOL(drm_dp_downstream_id); 1394 1395 /** 1396 * drm_dp_downstream_debug() - debug DP branch devices 1397 * @m: pointer for debugfs file 1398 * @dpcd: DisplayPort configuration data 1399 * @port_cap: port capabilities 1400 * @drm_edid: EDID 1401 * @aux: DisplayPort AUX channel 1402 * 1403 */ 1404 void drm_dp_downstream_debug(struct seq_file *m, 1405 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1406 const u8 port_cap[4], 1407 const struct drm_edid *drm_edid, 1408 struct drm_dp_aux *aux) 1409 { 1410 bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & 1411 DP_DETAILED_CAP_INFO_AVAILABLE; 1412 int clk; 1413 int bpc; 1414 char id[7]; 1415 int len; 1416 uint8_t rev[2]; 1417 int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; 1418 bool branch_device = drm_dp_is_branch(dpcd); 1419 1420 seq_printf(m, "\tDP branch device present: %s\n", 1421 str_yes_no(branch_device)); 1422 1423 if (!branch_device) 1424 return; 1425 1426 switch (type) { 1427 case DP_DS_PORT_TYPE_DP: 1428 seq_puts(m, "\t\tType: DisplayPort\n"); 1429 break; 1430 case DP_DS_PORT_TYPE_VGA: 1431 seq_puts(m, "\t\tType: VGA\n"); 1432 break; 1433 case DP_DS_PORT_TYPE_DVI: 1434 seq_puts(m, "\t\tType: DVI\n"); 1435 break; 1436 case DP_DS_PORT_TYPE_HDMI: 1437 seq_puts(m, "\t\tType: HDMI\n"); 1438 break; 1439 case DP_DS_PORT_TYPE_NON_EDID: 1440 seq_puts(m, "\t\tType: others without EDID support\n"); 1441 break; 1442 case DP_DS_PORT_TYPE_DP_DUALMODE: 1443 seq_puts(m, "\t\tType: DP++\n"); 1444 break; 1445 case DP_DS_PORT_TYPE_WIRELESS: 1446 seq_puts(m, "\t\tType: Wireless\n"); 1447 break; 1448 default: 1449 seq_puts(m, "\t\tType: N/A\n"); 1450 } 1451 1452 memset(id, 0, sizeof(id)); 1453 drm_dp_downstream_id(aux, id); 1454 seq_printf(m, "\t\tID: %s\n", id); 1455 1456 len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1); 1457 if (len > 0) 1458 seq_printf(m, "\t\tHW: %d.%d\n", 1459 (rev[0] & 0xf0) >> 4, rev[0] & 0xf); 1460 1461 len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, rev, 2); 1462 if (len > 0) 1463 seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]); 1464 1465 if (detailed_cap_info) { 1466 clk = drm_dp_downstream_max_dotclock(dpcd, port_cap); 1467 if (clk > 0) 1468 seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); 1469 1470 clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, drm_edid); 1471 if (clk > 0) 1472 seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); 1473 1474 clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, drm_edid); 1475 if (clk > 0) 1476 seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk); 1477 1478 bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, drm_edid); 1479 1480 if (bpc > 0) 1481 seq_printf(m, "\t\tMax bpc: %d\n", bpc); 1482 } 1483 } 1484 EXPORT_SYMBOL(drm_dp_downstream_debug); 1485 1486 /** 1487 * drm_dp_subconnector_type() - get DP branch device type 1488 * @dpcd: DisplayPort configuration data 1489 * @port_cap: port capabilities 1490 */ 1491 enum drm_mode_subconnector 1492 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1493 const u8 port_cap[4]) 1494 { 1495 int type; 1496 if (!drm_dp_is_branch(dpcd)) 1497 return DRM_MODE_SUBCONNECTOR_Native; 1498 /* DP 1.0 approach */ 1499 if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) { 1500 type = dpcd[DP_DOWNSTREAMPORT_PRESENT] & 1501 DP_DWN_STRM_PORT_TYPE_MASK; 1502 1503 switch (type) { 1504 case DP_DWN_STRM_PORT_TYPE_TMDS: 1505 /* Can be HDMI or DVI-D, DVI-D is a safer option */ 1506 return DRM_MODE_SUBCONNECTOR_DVID; 1507 case DP_DWN_STRM_PORT_TYPE_ANALOG: 1508 /* Can be VGA or DVI-A, VGA is more popular */ 1509 return DRM_MODE_SUBCONNECTOR_VGA; 1510 case DP_DWN_STRM_PORT_TYPE_DP: 1511 return DRM_MODE_SUBCONNECTOR_DisplayPort; 1512 case DP_DWN_STRM_PORT_TYPE_OTHER: 1513 default: 1514 return DRM_MODE_SUBCONNECTOR_Unknown; 1515 } 1516 } 1517 type = port_cap[0] & DP_DS_PORT_TYPE_MASK; 1518 1519 switch (type) { 1520 case DP_DS_PORT_TYPE_DP: 1521 case DP_DS_PORT_TYPE_DP_DUALMODE: 1522 return DRM_MODE_SUBCONNECTOR_DisplayPort; 1523 case DP_DS_PORT_TYPE_VGA: 1524 return DRM_MODE_SUBCONNECTOR_VGA; 1525 case DP_DS_PORT_TYPE_DVI: 1526 return DRM_MODE_SUBCONNECTOR_DVID; 1527 case DP_DS_PORT_TYPE_HDMI: 1528 return DRM_MODE_SUBCONNECTOR_HDMIA; 1529 case DP_DS_PORT_TYPE_WIRELESS: 1530 return DRM_MODE_SUBCONNECTOR_Wireless; 1531 case DP_DS_PORT_TYPE_NON_EDID: 1532 default: 1533 return DRM_MODE_SUBCONNECTOR_Unknown; 1534 } 1535 } 1536 EXPORT_SYMBOL(drm_dp_subconnector_type); 1537 1538 /** 1539 * drm_dp_set_subconnector_property - set subconnector for DP connector 1540 * @connector: connector to set property on 1541 * @status: connector status 1542 * @dpcd: DisplayPort configuration data 1543 * @port_cap: port capabilities 1544 * 1545 * Called by a driver on every detect event. 1546 */ 1547 void drm_dp_set_subconnector_property(struct drm_connector *connector, 1548 enum drm_connector_status status, 1549 const u8 *dpcd, 1550 const u8 port_cap[4]) 1551 { 1552 enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown; 1553 1554 if (status == connector_status_connected) 1555 subconnector = drm_dp_subconnector_type(dpcd, port_cap); 1556 drm_object_property_set_value(&connector->base, 1557 connector->dev->mode_config.dp_subconnector_property, 1558 subconnector); 1559 } 1560 EXPORT_SYMBOL(drm_dp_set_subconnector_property); 1561 1562 /** 1563 * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink 1564 * count 1565 * @connector: The DRM connector to check 1566 * @dpcd: A cached copy of the connector's DPCD RX capabilities 1567 * @desc: A cached copy of the connector's DP descriptor 1568 * 1569 * See also: drm_dp_read_sink_count() 1570 * 1571 * Returns: %True if the (e)DP connector has a valid sink count that should 1572 * be probed, %false otherwise. 1573 */ 1574 bool drm_dp_read_sink_count_cap(struct drm_connector *connector, 1575 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 1576 const struct drm_dp_desc *desc) 1577 { 1578 /* Some eDP panels don't set a valid value for the sink count */ 1579 return connector->connector_type != DRM_MODE_CONNECTOR_eDP && 1580 dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 && 1581 dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT && 1582 !drm_dp_has_quirk(desc, DP_DPCD_QUIRK_NO_SINK_COUNT); 1583 } 1584 EXPORT_SYMBOL(drm_dp_read_sink_count_cap); 1585 1586 /** 1587 * drm_dp_read_sink_count() - Retrieve the sink count for a given sink 1588 * @aux: The DP AUX channel to use 1589 * 1590 * See also: drm_dp_read_sink_count_cap() 1591 * 1592 * Returns: The current sink count reported by @aux, or a negative error code 1593 * otherwise. 1594 */ 1595 int drm_dp_read_sink_count(struct drm_dp_aux *aux) 1596 { 1597 u8 count; 1598 int ret; 1599 1600 ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count); 1601 if (ret < 0) 1602 return ret; 1603 if (ret != 1) 1604 return -EIO; 1605 1606 return DP_GET_SINK_COUNT(count); 1607 } 1608 EXPORT_SYMBOL(drm_dp_read_sink_count); 1609 1610 /* 1611 * I2C-over-AUX implementation 1612 */ 1613 1614 static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) 1615 { 1616 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 1617 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 1618 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 1619 I2C_FUNC_10BIT_ADDR; 1620 } 1621 1622 static void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg) 1623 { 1624 /* 1625 * In case of i2c defer or short i2c ack reply to a write, 1626 * we need to switch to WRITE_STATUS_UPDATE to drain the 1627 * rest of the message 1628 */ 1629 if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) { 1630 msg->request &= DP_AUX_I2C_MOT; 1631 msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE; 1632 } 1633 } 1634 1635 #define AUX_PRECHARGE_LEN 10 /* 10 to 16 */ 1636 #define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */ 1637 #define AUX_STOP_LEN 4 1638 #define AUX_CMD_LEN 4 1639 #define AUX_ADDRESS_LEN 20 1640 #define AUX_REPLY_PAD_LEN 4 1641 #define AUX_LENGTH_LEN 8 1642 1643 /* 1644 * Calculate the duration of the AUX request/reply in usec. Gives the 1645 * "best" case estimate, ie. successful while as short as possible. 1646 */ 1647 static int drm_dp_aux_req_duration(const struct drm_dp_aux_msg *msg) 1648 { 1649 int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + 1650 AUX_CMD_LEN + AUX_ADDRESS_LEN + AUX_LENGTH_LEN; 1651 1652 if ((msg->request & DP_AUX_I2C_READ) == 0) 1653 len += msg->size * 8; 1654 1655 return len; 1656 } 1657 1658 static int drm_dp_aux_reply_duration(const struct drm_dp_aux_msg *msg) 1659 { 1660 int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + 1661 AUX_CMD_LEN + AUX_REPLY_PAD_LEN; 1662 1663 /* 1664 * For read we expect what was asked. For writes there will 1665 * be 0 or 1 data bytes. Assume 0 for the "best" case. 1666 */ 1667 if (msg->request & DP_AUX_I2C_READ) 1668 len += msg->size * 8; 1669 1670 return len; 1671 } 1672 1673 #define I2C_START_LEN 1 1674 #define I2C_STOP_LEN 1 1675 #define I2C_ADDR_LEN 9 /* ADDRESS + R/W + ACK/NACK */ 1676 #define I2C_DATA_LEN 9 /* DATA + ACK/NACK */ 1677 1678 /* 1679 * Calculate the length of the i2c transfer in usec, assuming 1680 * the i2c bus speed is as specified. Gives the "worst" 1681 * case estimate, ie. successful while as long as possible. 1682 * Doesn't account the "MOT" bit, and instead assumes each 1683 * message includes a START, ADDRESS and STOP. Neither does it 1684 * account for additional random variables such as clock stretching. 1685 */ 1686 static int drm_dp_i2c_msg_duration(const struct drm_dp_aux_msg *msg, 1687 int i2c_speed_khz) 1688 { 1689 /* AUX bitrate is 1MHz, i2c bitrate as specified */ 1690 return DIV_ROUND_UP((I2C_START_LEN + I2C_ADDR_LEN + 1691 msg->size * I2C_DATA_LEN + 1692 I2C_STOP_LEN) * 1000, i2c_speed_khz); 1693 } 1694 1695 /* 1696 * Determine how many retries should be attempted to successfully transfer 1697 * the specified message, based on the estimated durations of the 1698 * i2c and AUX transfers. 1699 */ 1700 static int drm_dp_i2c_retry_count(const struct drm_dp_aux_msg *msg, 1701 int i2c_speed_khz) 1702 { 1703 int aux_time_us = drm_dp_aux_req_duration(msg) + 1704 drm_dp_aux_reply_duration(msg); 1705 int i2c_time_us = drm_dp_i2c_msg_duration(msg, i2c_speed_khz); 1706 1707 return DIV_ROUND_UP(i2c_time_us, aux_time_us + AUX_RETRY_INTERVAL); 1708 } 1709 1710 /* 1711 * FIXME currently assumes 10 kHz as some real world devices seem 1712 * to require it. We should query/set the speed via DPCD if supported. 1713 */ 1714 static int dp_aux_i2c_speed_khz __read_mostly = 10; 1715 module_param_unsafe(dp_aux_i2c_speed_khz, int, 0644); 1716 MODULE_PARM_DESC(dp_aux_i2c_speed_khz, 1717 "Assumed speed of the i2c bus in kHz, (1-400, default 10)"); 1718 1719 /* 1720 * Transfer a single I2C-over-AUX message and handle various error conditions, 1721 * retrying the transaction as appropriate. It is assumed that the 1722 * &drm_dp_aux.transfer function does not modify anything in the msg other than the 1723 * reply field. 1724 * 1725 * Returns bytes transferred on success, or a negative error code on failure. 1726 */ 1727 static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) 1728 { 1729 unsigned int retry, defer_i2c; 1730 int ret; 1731 /* 1732 * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device 1733 * is required to retry at least seven times upon receiving AUX_DEFER 1734 * before giving up the AUX transaction. 1735 * 1736 * We also try to account for the i2c bus speed. 1737 */ 1738 int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz)); 1739 1740 for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { 1741 ret = aux->transfer(aux, msg); 1742 if (ret < 0) { 1743 if (ret == -EBUSY) 1744 continue; 1745 1746 /* 1747 * While timeouts can be errors, they're usually normal 1748 * behavior (for instance, when a driver tries to 1749 * communicate with a non-existent DisplayPort device). 1750 * Avoid spamming the kernel log with timeout errors. 1751 */ 1752 if (ret == -ETIMEDOUT) 1753 drm_dbg_kms_ratelimited(aux->drm_dev, "%s: transaction timed out\n", 1754 aux->name); 1755 else 1756 drm_dbg_kms(aux->drm_dev, "%s: transaction failed: %d\n", 1757 aux->name, ret); 1758 return ret; 1759 } 1760 1761 1762 switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { 1763 case DP_AUX_NATIVE_REPLY_ACK: 1764 /* 1765 * For I2C-over-AUX transactions this isn't enough, we 1766 * need to check for the I2C ACK reply. 1767 */ 1768 break; 1769 1770 case DP_AUX_NATIVE_REPLY_NACK: 1771 drm_dbg_kms(aux->drm_dev, "%s: native nack (result=%d, size=%zu)\n", 1772 aux->name, ret, msg->size); 1773 return -EREMOTEIO; 1774 1775 case DP_AUX_NATIVE_REPLY_DEFER: 1776 drm_dbg_kms(aux->drm_dev, "%s: native defer\n", aux->name); 1777 /* 1778 * We could check for I2C bit rate capabilities and if 1779 * available adjust this interval. We could also be 1780 * more careful with DP-to-legacy adapters where a 1781 * long legacy cable may force very low I2C bit rates. 1782 * 1783 * For now just defer for long enough to hopefully be 1784 * safe for all use-cases. 1785 */ 1786 usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); 1787 continue; 1788 1789 default: 1790 drm_err(aux->drm_dev, "%s: invalid native reply %#04x\n", 1791 aux->name, msg->reply); 1792 return -EREMOTEIO; 1793 } 1794 1795 switch (msg->reply & DP_AUX_I2C_REPLY_MASK) { 1796 case DP_AUX_I2C_REPLY_ACK: 1797 /* 1798 * Both native ACK and I2C ACK replies received. We 1799 * can assume the transfer was successful. 1800 */ 1801 if (ret != msg->size) 1802 drm_dp_i2c_msg_write_status_update(msg); 1803 return ret; 1804 1805 case DP_AUX_I2C_REPLY_NACK: 1806 drm_dbg_kms(aux->drm_dev, "%s: I2C nack (result=%d, size=%zu)\n", 1807 aux->name, ret, msg->size); 1808 aux->i2c_nack_count++; 1809 return -EREMOTEIO; 1810 1811 case DP_AUX_I2C_REPLY_DEFER: 1812 drm_dbg_kms(aux->drm_dev, "%s: I2C defer\n", aux->name); 1813 /* DP Compliance Test 4.2.2.5 Requirement: 1814 * Must have at least 7 retries for I2C defers on the 1815 * transaction to pass this test 1816 */ 1817 aux->i2c_defer_count++; 1818 if (defer_i2c < 7) 1819 defer_i2c++; 1820 usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); 1821 drm_dp_i2c_msg_write_status_update(msg); 1822 1823 continue; 1824 1825 default: 1826 drm_err(aux->drm_dev, "%s: invalid I2C reply %#04x\n", 1827 aux->name, msg->reply); 1828 return -EREMOTEIO; 1829 } 1830 } 1831 1832 drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up\n", aux->name); 1833 return -EREMOTEIO; 1834 } 1835 1836 static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg, 1837 const struct i2c_msg *i2c_msg) 1838 { 1839 msg->request = (i2c_msg->flags & I2C_M_RD) ? 1840 DP_AUX_I2C_READ : DP_AUX_I2C_WRITE; 1841 if (!(i2c_msg->flags & I2C_M_STOP)) 1842 msg->request |= DP_AUX_I2C_MOT; 1843 } 1844 1845 /* 1846 * Keep retrying drm_dp_i2c_do_msg until all data has been transferred. 1847 * 1848 * Returns an error code on failure, or a recommended transfer size on success. 1849 */ 1850 static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg) 1851 { 1852 int err, ret = orig_msg->size; 1853 struct drm_dp_aux_msg msg = *orig_msg; 1854 1855 while (msg.size > 0) { 1856 err = drm_dp_i2c_do_msg(aux, &msg); 1857 if (err <= 0) 1858 return err == 0 ? -EPROTO : err; 1859 1860 if (err < msg.size && err < ret) { 1861 drm_dbg_kms(aux->drm_dev, 1862 "%s: Partial I2C reply: requested %zu bytes got %d bytes\n", 1863 aux->name, msg.size, err); 1864 ret = err; 1865 } 1866 1867 msg.size -= err; 1868 msg.buffer += err; 1869 } 1870 1871 return ret; 1872 } 1873 1874 /* 1875 * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX 1876 * packets to be as large as possible. If not, the I2C transactions never 1877 * succeed. Hence the default is maximum. 1878 */ 1879 static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES; 1880 module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644); 1881 MODULE_PARM_DESC(dp_aux_i2c_transfer_size, 1882 "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)"); 1883 1884 static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, 1885 int num) 1886 { 1887 struct drm_dp_aux *aux = adapter->algo_data; 1888 unsigned int i, j; 1889 unsigned transfer_size; 1890 struct drm_dp_aux_msg msg; 1891 int err = 0; 1892 1893 if (aux->powered_down) 1894 return -EBUSY; 1895 1896 dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES); 1897 1898 memset(&msg, 0, sizeof(msg)); 1899 1900 for (i = 0; i < num; i++) { 1901 msg.address = msgs[i].addr; 1902 drm_dp_i2c_msg_set_request(&msg, &msgs[i]); 1903 /* Send a bare address packet to start the transaction. 1904 * Zero sized messages specify an address only (bare 1905 * address) transaction. 1906 */ 1907 msg.buffer = NULL; 1908 msg.size = 0; 1909 err = drm_dp_i2c_do_msg(aux, &msg); 1910 1911 /* 1912 * Reset msg.request in case in case it got 1913 * changed into a WRITE_STATUS_UPDATE. 1914 */ 1915 drm_dp_i2c_msg_set_request(&msg, &msgs[i]); 1916 1917 if (err < 0) 1918 break; 1919 /* We want each transaction to be as large as possible, but 1920 * we'll go to smaller sizes if the hardware gives us a 1921 * short reply. 1922 */ 1923 transfer_size = dp_aux_i2c_transfer_size; 1924 for (j = 0; j < msgs[i].len; j += msg.size) { 1925 msg.buffer = msgs[i].buf + j; 1926 msg.size = min(transfer_size, msgs[i].len - j); 1927 1928 err = drm_dp_i2c_drain_msg(aux, &msg); 1929 1930 /* 1931 * Reset msg.request in case in case it got 1932 * changed into a WRITE_STATUS_UPDATE. 1933 */ 1934 drm_dp_i2c_msg_set_request(&msg, &msgs[i]); 1935 1936 if (err < 0) 1937 break; 1938 transfer_size = err; 1939 } 1940 if (err < 0) 1941 break; 1942 } 1943 if (err >= 0) 1944 err = num; 1945 /* Send a bare address packet to close out the transaction. 1946 * Zero sized messages specify an address only (bare 1947 * address) transaction. 1948 */ 1949 msg.request &= ~DP_AUX_I2C_MOT; 1950 msg.buffer = NULL; 1951 msg.size = 0; 1952 (void)drm_dp_i2c_do_msg(aux, &msg); 1953 1954 return err; 1955 } 1956 1957 static const struct i2c_algorithm drm_dp_i2c_algo = { 1958 .functionality = drm_dp_i2c_functionality, 1959 .master_xfer = drm_dp_i2c_xfer, 1960 }; 1961 1962 static struct drm_dp_aux *i2c_to_aux(struct i2c_adapter *i2c) 1963 { 1964 return container_of(i2c, struct drm_dp_aux, ddc); 1965 } 1966 1967 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags) 1968 { 1969 mutex_lock(&i2c_to_aux(i2c)->hw_mutex); 1970 } 1971 1972 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags) 1973 { 1974 return mutex_trylock(&i2c_to_aux(i2c)->hw_mutex); 1975 } 1976 1977 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) 1978 { 1979 mutex_unlock(&i2c_to_aux(i2c)->hw_mutex); 1980 } 1981 1982 static const struct i2c_lock_operations drm_dp_i2c_lock_ops = { 1983 .lock_bus = lock_bus, 1984 .trylock_bus = trylock_bus, 1985 .unlock_bus = unlock_bus, 1986 }; 1987 1988 static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc) 1989 { 1990 u8 buf, count; 1991 int ret; 1992 1993 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); 1994 if (ret < 0) 1995 return ret; 1996 1997 WARN_ON(!(buf & DP_TEST_SINK_START)); 1998 1999 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK_MISC, &buf); 2000 if (ret < 0) 2001 return ret; 2002 2003 count = buf & DP_TEST_COUNT_MASK; 2004 if (count == aux->crc_count) 2005 return -EAGAIN; /* No CRC yet */ 2006 2007 aux->crc_count = count; 2008 2009 /* 2010 * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes 2011 * per component (RGB or CrYCb). 2012 */ 2013 ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6); 2014 if (ret < 0) 2015 return ret; 2016 2017 return 0; 2018 } 2019 2020 static void drm_dp_aux_crc_work(struct work_struct *work) 2021 { 2022 struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux, 2023 crc_work); 2024 struct drm_crtc *crtc; 2025 u8 crc_bytes[6]; 2026 uint32_t crcs[3]; 2027 int ret; 2028 2029 if (WARN_ON(!aux->crtc)) 2030 return; 2031 2032 crtc = aux->crtc; 2033 while (crtc->crc.opened) { 2034 drm_crtc_wait_one_vblank(crtc); 2035 if (!crtc->crc.opened) 2036 break; 2037 2038 ret = drm_dp_aux_get_crc(aux, crc_bytes); 2039 if (ret == -EAGAIN) { 2040 usleep_range(1000, 2000); 2041 ret = drm_dp_aux_get_crc(aux, crc_bytes); 2042 } 2043 2044 if (ret == -EAGAIN) { 2045 drm_dbg_kms(aux->drm_dev, "%s: Get CRC failed after retrying: %d\n", 2046 aux->name, ret); 2047 continue; 2048 } else if (ret) { 2049 drm_dbg_kms(aux->drm_dev, "%s: Failed to get a CRC: %d\n", aux->name, ret); 2050 continue; 2051 } 2052 2053 crcs[0] = crc_bytes[0] | crc_bytes[1] << 8; 2054 crcs[1] = crc_bytes[2] | crc_bytes[3] << 8; 2055 crcs[2] = crc_bytes[4] | crc_bytes[5] << 8; 2056 drm_crtc_add_crc_entry(crtc, false, 0, crcs); 2057 } 2058 } 2059 2060 /** 2061 * drm_dp_remote_aux_init() - minimally initialise a remote aux channel 2062 * @aux: DisplayPort AUX channel 2063 * 2064 * Used for remote aux channel in general. Merely initialize the crc work 2065 * struct. 2066 */ 2067 void drm_dp_remote_aux_init(struct drm_dp_aux *aux) 2068 { 2069 INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); 2070 } 2071 EXPORT_SYMBOL(drm_dp_remote_aux_init); 2072 2073 /** 2074 * drm_dp_aux_init() - minimally initialise an aux channel 2075 * @aux: DisplayPort AUX channel 2076 * 2077 * If you need to use the drm_dp_aux's i2c adapter prior to registering it with 2078 * the outside world, call drm_dp_aux_init() first. For drivers which are 2079 * grandparents to their AUX adapters (e.g. the AUX adapter is parented by a 2080 * &drm_connector), you must still call drm_dp_aux_register() once the connector 2081 * has been registered to allow userspace access to the auxiliary DP channel. 2082 * Likewise, for such drivers you should also assign &drm_dp_aux.drm_dev as 2083 * early as possible so that the &drm_device that corresponds to the AUX adapter 2084 * may be mentioned in debugging output from the DRM DP helpers. 2085 * 2086 * For devices which use a separate platform device for their AUX adapters, this 2087 * may be called as early as required by the driver. 2088 * 2089 */ 2090 void drm_dp_aux_init(struct drm_dp_aux *aux) 2091 { 2092 mutex_init(&aux->hw_mutex); 2093 mutex_init(&aux->cec.lock); 2094 INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); 2095 2096 aux->ddc.algo = &drm_dp_i2c_algo; 2097 aux->ddc.algo_data = aux; 2098 aux->ddc.retries = 3; 2099 2100 aux->ddc.lock_ops = &drm_dp_i2c_lock_ops; 2101 } 2102 EXPORT_SYMBOL(drm_dp_aux_init); 2103 2104 /** 2105 * drm_dp_aux_register() - initialise and register aux channel 2106 * @aux: DisplayPort AUX channel 2107 * 2108 * Automatically calls drm_dp_aux_init() if this hasn't been done yet. This 2109 * should only be called once the parent of @aux, &drm_dp_aux.dev, is 2110 * initialized. For devices which are grandparents of their AUX channels, 2111 * &drm_dp_aux.dev will typically be the &drm_connector &device which 2112 * corresponds to @aux. For these devices, it's advised to call 2113 * drm_dp_aux_register() in &drm_connector_funcs.late_register, and likewise to 2114 * call drm_dp_aux_unregister() in &drm_connector_funcs.early_unregister. 2115 * Functions which don't follow this will likely Oops when 2116 * %CONFIG_DRM_DP_AUX_CHARDEV is enabled. 2117 * 2118 * For devices where the AUX channel is a device that exists independently of 2119 * the &drm_device that uses it, such as SoCs and bridge devices, it is 2120 * recommended to call drm_dp_aux_register() after a &drm_device has been 2121 * assigned to &drm_dp_aux.drm_dev, and likewise to call 2122 * drm_dp_aux_unregister() once the &drm_device should no longer be associated 2123 * with the AUX channel (e.g. on bridge detach). 2124 * 2125 * Drivers which need to use the aux channel before either of the two points 2126 * mentioned above need to call drm_dp_aux_init() in order to use the AUX 2127 * channel before registration. 2128 * 2129 * Returns 0 on success or a negative error code on failure. 2130 */ 2131 int drm_dp_aux_register(struct drm_dp_aux *aux) 2132 { 2133 int ret; 2134 2135 WARN_ON_ONCE(!aux->drm_dev); 2136 2137 if (!aux->ddc.algo) 2138 drm_dp_aux_init(aux); 2139 2140 aux->ddc.owner = THIS_MODULE; 2141 aux->ddc.dev.parent = aux->dev; 2142 2143 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), 2144 sizeof(aux->ddc.name)); 2145 2146 ret = drm_dp_aux_register_devnode(aux); 2147 if (ret) 2148 return ret; 2149 2150 ret = i2c_add_adapter(&aux->ddc); 2151 if (ret) { 2152 drm_dp_aux_unregister_devnode(aux); 2153 return ret; 2154 } 2155 2156 return 0; 2157 } 2158 EXPORT_SYMBOL(drm_dp_aux_register); 2159 2160 /** 2161 * drm_dp_aux_unregister() - unregister an AUX adapter 2162 * @aux: DisplayPort AUX channel 2163 */ 2164 void drm_dp_aux_unregister(struct drm_dp_aux *aux) 2165 { 2166 drm_dp_aux_unregister_devnode(aux); 2167 i2c_del_adapter(&aux->ddc); 2168 } 2169 EXPORT_SYMBOL(drm_dp_aux_unregister); 2170 2171 #define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x) 2172 2173 /** 2174 * drm_dp_psr_setup_time() - PSR setup in time usec 2175 * @psr_cap: PSR capabilities from DPCD 2176 * 2177 * Returns: 2178 * PSR setup time for the panel in microseconds, negative 2179 * error code on failure. 2180 */ 2181 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]) 2182 { 2183 static const u16 psr_setup_time_us[] = { 2184 PSR_SETUP_TIME(330), 2185 PSR_SETUP_TIME(275), 2186 PSR_SETUP_TIME(220), 2187 PSR_SETUP_TIME(165), 2188 PSR_SETUP_TIME(110), 2189 PSR_SETUP_TIME(55), 2190 PSR_SETUP_TIME(0), 2191 }; 2192 int i; 2193 2194 i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT; 2195 if (i >= ARRAY_SIZE(psr_setup_time_us)) 2196 return -EINVAL; 2197 2198 return psr_setup_time_us[i]; 2199 } 2200 EXPORT_SYMBOL(drm_dp_psr_setup_time); 2201 2202 #undef PSR_SETUP_TIME 2203 2204 /** 2205 * drm_dp_start_crc() - start capture of frame CRCs 2206 * @aux: DisplayPort AUX channel 2207 * @crtc: CRTC displaying the frames whose CRCs are to be captured 2208 * 2209 * Returns 0 on success or a negative error code on failure. 2210 */ 2211 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc) 2212 { 2213 u8 buf; 2214 int ret; 2215 2216 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); 2217 if (ret < 0) 2218 return ret; 2219 2220 ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START); 2221 if (ret < 0) 2222 return ret; 2223 2224 aux->crc_count = 0; 2225 aux->crtc = crtc; 2226 schedule_work(&aux->crc_work); 2227 2228 return 0; 2229 } 2230 EXPORT_SYMBOL(drm_dp_start_crc); 2231 2232 /** 2233 * drm_dp_stop_crc() - stop capture of frame CRCs 2234 * @aux: DisplayPort AUX channel 2235 * 2236 * Returns 0 on success or a negative error code on failure. 2237 */ 2238 int drm_dp_stop_crc(struct drm_dp_aux *aux) 2239 { 2240 u8 buf; 2241 int ret; 2242 2243 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); 2244 if (ret < 0) 2245 return ret; 2246 2247 ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START); 2248 if (ret < 0) 2249 return ret; 2250 2251 flush_work(&aux->crc_work); 2252 aux->crtc = NULL; 2253 2254 return 0; 2255 } 2256 EXPORT_SYMBOL(drm_dp_stop_crc); 2257 2258 struct dpcd_quirk { 2259 u8 oui[3]; 2260 u8 device_id[6]; 2261 bool is_branch; 2262 u32 quirks; 2263 }; 2264 2265 #define OUI(first, second, third) { (first), (second), (third) } 2266 #define DEVICE_ID(first, second, third, fourth, fifth, sixth) \ 2267 { (first), (second), (third), (fourth), (fifth), (sixth) } 2268 2269 #define DEVICE_ID_ANY DEVICE_ID(0, 0, 0, 0, 0, 0) 2270 2271 static const struct dpcd_quirk dpcd_quirk_list[] = { 2272 /* Analogix 7737 needs reduced M and N at HBR2 link rates */ 2273 { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, 2274 /* LG LP140WF6-SPM1 eDP panel */ 2275 { OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, 2276 /* Apple panels need some additional handling to support PSR */ 2277 { OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) }, 2278 /* CH7511 seems to leave SINK_COUNT zeroed */ 2279 { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) }, 2280 /* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */ 2281 { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) }, 2282 /* Synaptics DP1.4 MST hubs require DSC for some modes on which it applies HBLANK expansion. */ 2283 { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC) }, 2284 /* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */ 2285 { 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) }, 2286 }; 2287 2288 #undef OUI 2289 2290 /* 2291 * Get a bit mask of DPCD quirks for the sink/branch device identified by 2292 * ident. The quirk data is shared but it's up to the drivers to act on the 2293 * data. 2294 * 2295 * For now, only the OUI (first three bytes) is used, but this may be extended 2296 * to device identification string and hardware/firmware revisions later. 2297 */ 2298 static u32 2299 drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) 2300 { 2301 const struct dpcd_quirk *quirk; 2302 u32 quirks = 0; 2303 int i; 2304 u8 any_device[] = DEVICE_ID_ANY; 2305 2306 for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { 2307 quirk = &dpcd_quirk_list[i]; 2308 2309 if (quirk->is_branch != is_branch) 2310 continue; 2311 2312 if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) 2313 continue; 2314 2315 if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 && 2316 memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0) 2317 continue; 2318 2319 quirks |= quirk->quirks; 2320 } 2321 2322 return quirks; 2323 } 2324 2325 #undef DEVICE_ID_ANY 2326 #undef DEVICE_ID 2327 2328 /** 2329 * drm_dp_read_desc - read sink/branch descriptor from DPCD 2330 * @aux: DisplayPort AUX channel 2331 * @desc: Device descriptor to fill from DPCD 2332 * @is_branch: true for branch devices, false for sink devices 2333 * 2334 * Read DPCD 0x400 (sink) or 0x500 (branch) into @desc. Also debug log the 2335 * identification. 2336 * 2337 * Returns 0 on success or a negative error code on failure. 2338 */ 2339 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, 2340 bool is_branch) 2341 { 2342 struct drm_dp_dpcd_ident *ident = &desc->ident; 2343 unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI; 2344 int ret, dev_id_len; 2345 2346 ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident)); 2347 if (ret < 0) 2348 return ret; 2349 2350 desc->quirks = drm_dp_get_quirks(ident, is_branch); 2351 2352 dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); 2353 2354 drm_dbg_kms(aux->drm_dev, 2355 "%s: DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", 2356 aux->name, is_branch ? "branch" : "sink", 2357 (int)sizeof(ident->oui), ident->oui, dev_id_len, 2358 ident->device_id, ident->hw_rev >> 4, ident->hw_rev & 0xf, 2359 ident->sw_major_rev, ident->sw_minor_rev, desc->quirks); 2360 2361 return 0; 2362 } 2363 EXPORT_SYMBOL(drm_dp_read_desc); 2364 2365 /** 2366 * drm_dp_dsc_sink_bpp_incr() - Get bits per pixel increment 2367 * @dsc_dpcd: DSC capabilities from DPCD 2368 * 2369 * Returns the bpp precision supported by the DP sink. 2370 */ 2371 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 2372 { 2373 u8 bpp_increment_dpcd = dsc_dpcd[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT]; 2374 2375 switch (bpp_increment_dpcd) { 2376 case DP_DSC_BITS_PER_PIXEL_1_16: 2377 return 16; 2378 case DP_DSC_BITS_PER_PIXEL_1_8: 2379 return 8; 2380 case DP_DSC_BITS_PER_PIXEL_1_4: 2381 return 4; 2382 case DP_DSC_BITS_PER_PIXEL_1_2: 2383 return 2; 2384 case DP_DSC_BITS_PER_PIXEL_1_1: 2385 return 1; 2386 } 2387 2388 return 0; 2389 } 2390 EXPORT_SYMBOL(drm_dp_dsc_sink_bpp_incr); 2391 2392 /** 2393 * drm_dp_dsc_sink_max_slice_count() - Get the max slice count 2394 * supported by the DSC sink. 2395 * @dsc_dpcd: DSC capabilities from DPCD 2396 * @is_edp: true if its eDP, false for DP 2397 * 2398 * Read the slice capabilities DPCD register from DSC sink to get 2399 * the maximum slice count supported. This is used to populate 2400 * the DSC parameters in the &struct drm_dsc_config by the driver. 2401 * Driver creates an infoframe using these parameters to populate 2402 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2403 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2404 * 2405 * Returns: 2406 * Maximum slice count supported by DSC sink or 0 its invalid 2407 */ 2408 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 2409 bool is_edp) 2410 { 2411 u8 slice_cap1 = dsc_dpcd[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT]; 2412 2413 if (is_edp) { 2414 /* For eDP, register DSC_SLICE_CAPABILITIES_1 gives slice count */ 2415 if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) 2416 return 4; 2417 if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) 2418 return 2; 2419 if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) 2420 return 1; 2421 } else { 2422 /* For DP, use values from DSC_SLICE_CAP_1 and DSC_SLICE_CAP2 */ 2423 u8 slice_cap2 = dsc_dpcd[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT]; 2424 2425 if (slice_cap2 & DP_DSC_24_PER_DP_DSC_SINK) 2426 return 24; 2427 if (slice_cap2 & DP_DSC_20_PER_DP_DSC_SINK) 2428 return 20; 2429 if (slice_cap2 & DP_DSC_16_PER_DP_DSC_SINK) 2430 return 16; 2431 if (slice_cap1 & DP_DSC_12_PER_DP_DSC_SINK) 2432 return 12; 2433 if (slice_cap1 & DP_DSC_10_PER_DP_DSC_SINK) 2434 return 10; 2435 if (slice_cap1 & DP_DSC_8_PER_DP_DSC_SINK) 2436 return 8; 2437 if (slice_cap1 & DP_DSC_6_PER_DP_DSC_SINK) 2438 return 6; 2439 if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) 2440 return 4; 2441 if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) 2442 return 2; 2443 if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) 2444 return 1; 2445 } 2446 2447 return 0; 2448 } 2449 EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count); 2450 2451 /** 2452 * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits 2453 * @dsc_dpcd: DSC capabilities from DPCD 2454 * 2455 * Read the DSC DPCD register to parse the line buffer depth in bits which is 2456 * number of bits of precision within the decoder line buffer supported by 2457 * the DSC sink. This is used to populate the DSC parameters in the 2458 * &struct drm_dsc_config by the driver. 2459 * Driver creates an infoframe using these parameters to populate 2460 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2461 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2462 * 2463 * Returns: 2464 * Line buffer depth supported by DSC panel or 0 its invalid 2465 */ 2466 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 2467 { 2468 u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT]; 2469 2470 switch (line_buf_depth & DP_DSC_LINE_BUF_BIT_DEPTH_MASK) { 2471 case DP_DSC_LINE_BUF_BIT_DEPTH_9: 2472 return 9; 2473 case DP_DSC_LINE_BUF_BIT_DEPTH_10: 2474 return 10; 2475 case DP_DSC_LINE_BUF_BIT_DEPTH_11: 2476 return 11; 2477 case DP_DSC_LINE_BUF_BIT_DEPTH_12: 2478 return 12; 2479 case DP_DSC_LINE_BUF_BIT_DEPTH_13: 2480 return 13; 2481 case DP_DSC_LINE_BUF_BIT_DEPTH_14: 2482 return 14; 2483 case DP_DSC_LINE_BUF_BIT_DEPTH_15: 2484 return 15; 2485 case DP_DSC_LINE_BUF_BIT_DEPTH_16: 2486 return 16; 2487 case DP_DSC_LINE_BUF_BIT_DEPTH_8: 2488 return 8; 2489 } 2490 2491 return 0; 2492 } 2493 EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth); 2494 2495 /** 2496 * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component 2497 * values supported by the DSC sink. 2498 * @dsc_dpcd: DSC capabilities from DPCD 2499 * @dsc_bpc: An array to be filled by this helper with supported 2500 * input bpcs. 2501 * 2502 * Read the DSC DPCD from the sink device to parse the supported bits per 2503 * component values. This is used to populate the DSC parameters 2504 * in the &struct drm_dsc_config by the driver. 2505 * Driver creates an infoframe using these parameters to populate 2506 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2507 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2508 * 2509 * Returns: 2510 * Number of input BPC values parsed from the DPCD 2511 */ 2512 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 2513 u8 dsc_bpc[3]) 2514 { 2515 int num_bpc = 0; 2516 u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT]; 2517 2518 if (!drm_dp_sink_supports_dsc(dsc_dpcd)) 2519 return 0; 2520 2521 if (color_depth & DP_DSC_12_BPC) 2522 dsc_bpc[num_bpc++] = 12; 2523 if (color_depth & DP_DSC_10_BPC) 2524 dsc_bpc[num_bpc++] = 10; 2525 2526 /* A DP DSC Sink device shall support 8 bpc. */ 2527 dsc_bpc[num_bpc++] = 8; 2528 2529 return num_bpc; 2530 } 2531 EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); 2532 2533 static int drm_dp_read_lttpr_regs(struct drm_dp_aux *aux, 2534 const u8 dpcd[DP_RECEIVER_CAP_SIZE], int address, 2535 u8 *buf, int buf_size) 2536 { 2537 /* 2538 * At least the DELL P2715Q monitor with a DPCD_REV < 0x14 returns 2539 * corrupted values when reading from the 0xF0000- range with a block 2540 * size bigger than 1. 2541 */ 2542 int block_size = dpcd[DP_DPCD_REV] < 0x14 ? 1 : buf_size; 2543 int offset; 2544 int ret; 2545 2546 for (offset = 0; offset < buf_size; offset += block_size) { 2547 ret = drm_dp_dpcd_read(aux, 2548 address + offset, 2549 &buf[offset], block_size); 2550 if (ret < 0) 2551 return ret; 2552 2553 WARN_ON(ret != block_size); 2554 } 2555 2556 return 0; 2557 } 2558 2559 /** 2560 * drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities 2561 * @aux: DisplayPort AUX channel 2562 * @dpcd: DisplayPort configuration data 2563 * @caps: buffer to return the capability info in 2564 * 2565 * Read capabilities common to all LTTPRs. 2566 * 2567 * Returns 0 on success or a negative error code on failure. 2568 */ 2569 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, 2570 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 2571 u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 2572 { 2573 return drm_dp_read_lttpr_regs(aux, dpcd, 2574 DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, 2575 caps, DP_LTTPR_COMMON_CAP_SIZE); 2576 } 2577 EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps); 2578 2579 /** 2580 * drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY 2581 * @aux: DisplayPort AUX channel 2582 * @dpcd: DisplayPort configuration data 2583 * @dp_phy: LTTPR PHY to read the capabilities for 2584 * @caps: buffer to return the capability info in 2585 * 2586 * Read the capabilities for the given LTTPR PHY. 2587 * 2588 * Returns 0 on success or a negative error code on failure. 2589 */ 2590 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux, 2591 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 2592 enum drm_dp_phy dp_phy, 2593 u8 caps[DP_LTTPR_PHY_CAP_SIZE]) 2594 { 2595 return drm_dp_read_lttpr_regs(aux, dpcd, 2596 DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy), 2597 caps, DP_LTTPR_PHY_CAP_SIZE); 2598 } 2599 EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps); 2600 2601 static u8 dp_lttpr_common_cap(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE], int r) 2602 { 2603 return caps[r - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV]; 2604 } 2605 2606 /** 2607 * drm_dp_lttpr_count - get the number of detected LTTPRs 2608 * @caps: LTTPR common capabilities 2609 * 2610 * Get the number of detected LTTPRs from the LTTPR common capabilities info. 2611 * 2612 * Returns: 2613 * -ERANGE if more than supported number (8) of LTTPRs are detected 2614 * -EINVAL if the DP_PHY_REPEATER_CNT register contains an invalid value 2615 * otherwise the number of detected LTTPRs 2616 */ 2617 int drm_dp_lttpr_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 2618 { 2619 u8 count = dp_lttpr_common_cap(caps, DP_PHY_REPEATER_CNT); 2620 2621 switch (hweight8(count)) { 2622 case 0: 2623 return 0; 2624 case 1: 2625 return 8 - ilog2(count); 2626 case 8: 2627 return -ERANGE; 2628 default: 2629 return -EINVAL; 2630 } 2631 } 2632 EXPORT_SYMBOL(drm_dp_lttpr_count); 2633 2634 /** 2635 * drm_dp_lttpr_max_link_rate - get the maximum link rate supported by all LTTPRs 2636 * @caps: LTTPR common capabilities 2637 * 2638 * Returns the maximum link rate supported by all detected LTTPRs. 2639 */ 2640 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 2641 { 2642 u8 rate = dp_lttpr_common_cap(caps, DP_MAX_LINK_RATE_PHY_REPEATER); 2643 2644 return drm_dp_bw_code_to_link_rate(rate); 2645 } 2646 EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate); 2647 2648 /** 2649 * drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs 2650 * @caps: LTTPR common capabilities 2651 * 2652 * Returns the maximum lane count supported by all detected LTTPRs. 2653 */ 2654 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 2655 { 2656 u8 max_lanes = dp_lttpr_common_cap(caps, DP_MAX_LANE_COUNT_PHY_REPEATER); 2657 2658 return max_lanes & DP_MAX_LANE_COUNT_MASK; 2659 } 2660 EXPORT_SYMBOL(drm_dp_lttpr_max_lane_count); 2661 2662 /** 2663 * drm_dp_lttpr_voltage_swing_level_3_supported - check for LTTPR vswing3 support 2664 * @caps: LTTPR PHY capabilities 2665 * 2666 * Returns true if the @caps for an LTTPR TX PHY indicate support for 2667 * voltage swing level 3. 2668 */ 2669 bool 2670 drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) 2671 { 2672 u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); 2673 2674 return txcap & DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED; 2675 } 2676 EXPORT_SYMBOL(drm_dp_lttpr_voltage_swing_level_3_supported); 2677 2678 /** 2679 * drm_dp_lttpr_pre_emphasis_level_3_supported - check for LTTPR preemph3 support 2680 * @caps: LTTPR PHY capabilities 2681 * 2682 * Returns true if the @caps for an LTTPR TX PHY indicate support for 2683 * pre-emphasis level 3. 2684 */ 2685 bool 2686 drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) 2687 { 2688 u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); 2689 2690 return txcap & DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED; 2691 } 2692 EXPORT_SYMBOL(drm_dp_lttpr_pre_emphasis_level_3_supported); 2693 2694 /** 2695 * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink. 2696 * @aux: DisplayPort AUX channel 2697 * @data: DP phy compliance test parameters. 2698 * 2699 * Returns 0 on success or a negative error code on failure. 2700 */ 2701 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, 2702 struct drm_dp_phy_test_params *data) 2703 { 2704 int err; 2705 u8 rate, lanes; 2706 2707 err = drm_dp_dpcd_readb(aux, DP_TEST_LINK_RATE, &rate); 2708 if (err < 0) 2709 return err; 2710 data->link_rate = drm_dp_bw_code_to_link_rate(rate); 2711 2712 err = drm_dp_dpcd_readb(aux, DP_TEST_LANE_COUNT, &lanes); 2713 if (err < 0) 2714 return err; 2715 data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK; 2716 2717 if (lanes & DP_ENHANCED_FRAME_CAP) 2718 data->enhanced_frame_cap = true; 2719 2720 err = drm_dp_dpcd_readb(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern); 2721 if (err < 0) 2722 return err; 2723 2724 switch (data->phy_pattern) { 2725 case DP_PHY_TEST_PATTERN_80BIT_CUSTOM: 2726 err = drm_dp_dpcd_read(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0, 2727 &data->custom80, sizeof(data->custom80)); 2728 if (err < 0) 2729 return err; 2730 2731 break; 2732 case DP_PHY_TEST_PATTERN_CP2520: 2733 err = drm_dp_dpcd_read(aux, DP_TEST_HBR2_SCRAMBLER_RESET, 2734 &data->hbr2_reset, 2735 sizeof(data->hbr2_reset)); 2736 if (err < 0) 2737 return err; 2738 } 2739 2740 return 0; 2741 } 2742 EXPORT_SYMBOL(drm_dp_get_phy_test_pattern); 2743 2744 /** 2745 * drm_dp_set_phy_test_pattern() - set the pattern to the sink. 2746 * @aux: DisplayPort AUX channel 2747 * @data: DP phy compliance test parameters. 2748 * @dp_rev: DP revision to use for compliance testing 2749 * 2750 * Returns 0 on success or a negative error code on failure. 2751 */ 2752 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, 2753 struct drm_dp_phy_test_params *data, u8 dp_rev) 2754 { 2755 int err, i; 2756 u8 test_pattern; 2757 2758 test_pattern = data->phy_pattern; 2759 if (dp_rev < 0x12) { 2760 test_pattern = (test_pattern << 2) & 2761 DP_LINK_QUAL_PATTERN_11_MASK; 2762 err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, 2763 test_pattern); 2764 if (err < 0) 2765 return err; 2766 } else { 2767 for (i = 0; i < data->num_lanes; i++) { 2768 err = drm_dp_dpcd_writeb(aux, 2769 DP_LINK_QUAL_LANE0_SET + i, 2770 test_pattern); 2771 if (err < 0) 2772 return err; 2773 } 2774 } 2775 2776 return 0; 2777 } 2778 EXPORT_SYMBOL(drm_dp_set_phy_test_pattern); 2779 2780 static const char *dp_pixelformat_get_name(enum dp_pixelformat pixelformat) 2781 { 2782 if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) 2783 return "Invalid"; 2784 2785 switch (pixelformat) { 2786 case DP_PIXELFORMAT_RGB: 2787 return "RGB"; 2788 case DP_PIXELFORMAT_YUV444: 2789 return "YUV444"; 2790 case DP_PIXELFORMAT_YUV422: 2791 return "YUV422"; 2792 case DP_PIXELFORMAT_YUV420: 2793 return "YUV420"; 2794 case DP_PIXELFORMAT_Y_ONLY: 2795 return "Y_ONLY"; 2796 case DP_PIXELFORMAT_RAW: 2797 return "RAW"; 2798 default: 2799 return "Reserved"; 2800 } 2801 } 2802 2803 static const char *dp_colorimetry_get_name(enum dp_pixelformat pixelformat, 2804 enum dp_colorimetry colorimetry) 2805 { 2806 if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) 2807 return "Invalid"; 2808 2809 switch (colorimetry) { 2810 case DP_COLORIMETRY_DEFAULT: 2811 switch (pixelformat) { 2812 case DP_PIXELFORMAT_RGB: 2813 return "sRGB"; 2814 case DP_PIXELFORMAT_YUV444: 2815 case DP_PIXELFORMAT_YUV422: 2816 case DP_PIXELFORMAT_YUV420: 2817 return "BT.601"; 2818 case DP_PIXELFORMAT_Y_ONLY: 2819 return "DICOM PS3.14"; 2820 case DP_PIXELFORMAT_RAW: 2821 return "Custom Color Profile"; 2822 default: 2823 return "Reserved"; 2824 } 2825 case DP_COLORIMETRY_RGB_WIDE_FIXED: /* and DP_COLORIMETRY_BT709_YCC */ 2826 switch (pixelformat) { 2827 case DP_PIXELFORMAT_RGB: 2828 return "Wide Fixed"; 2829 case DP_PIXELFORMAT_YUV444: 2830 case DP_PIXELFORMAT_YUV422: 2831 case DP_PIXELFORMAT_YUV420: 2832 return "BT.709"; 2833 default: 2834 return "Reserved"; 2835 } 2836 case DP_COLORIMETRY_RGB_WIDE_FLOAT: /* and DP_COLORIMETRY_XVYCC_601 */ 2837 switch (pixelformat) { 2838 case DP_PIXELFORMAT_RGB: 2839 return "Wide Float"; 2840 case DP_PIXELFORMAT_YUV444: 2841 case DP_PIXELFORMAT_YUV422: 2842 case DP_PIXELFORMAT_YUV420: 2843 return "xvYCC 601"; 2844 default: 2845 return "Reserved"; 2846 } 2847 case DP_COLORIMETRY_OPRGB: /* and DP_COLORIMETRY_XVYCC_709 */ 2848 switch (pixelformat) { 2849 case DP_PIXELFORMAT_RGB: 2850 return "OpRGB"; 2851 case DP_PIXELFORMAT_YUV444: 2852 case DP_PIXELFORMAT_YUV422: 2853 case DP_PIXELFORMAT_YUV420: 2854 return "xvYCC 709"; 2855 default: 2856 return "Reserved"; 2857 } 2858 case DP_COLORIMETRY_DCI_P3_RGB: /* and DP_COLORIMETRY_SYCC_601 */ 2859 switch (pixelformat) { 2860 case DP_PIXELFORMAT_RGB: 2861 return "DCI-P3"; 2862 case DP_PIXELFORMAT_YUV444: 2863 case DP_PIXELFORMAT_YUV422: 2864 case DP_PIXELFORMAT_YUV420: 2865 return "sYCC 601"; 2866 default: 2867 return "Reserved"; 2868 } 2869 case DP_COLORIMETRY_RGB_CUSTOM: /* and DP_COLORIMETRY_OPYCC_601 */ 2870 switch (pixelformat) { 2871 case DP_PIXELFORMAT_RGB: 2872 return "Custom Profile"; 2873 case DP_PIXELFORMAT_YUV444: 2874 case DP_PIXELFORMAT_YUV422: 2875 case DP_PIXELFORMAT_YUV420: 2876 return "OpYCC 601"; 2877 default: 2878 return "Reserved"; 2879 } 2880 case DP_COLORIMETRY_BT2020_RGB: /* and DP_COLORIMETRY_BT2020_CYCC */ 2881 switch (pixelformat) { 2882 case DP_PIXELFORMAT_RGB: 2883 return "BT.2020 RGB"; 2884 case DP_PIXELFORMAT_YUV444: 2885 case DP_PIXELFORMAT_YUV422: 2886 case DP_PIXELFORMAT_YUV420: 2887 return "BT.2020 CYCC"; 2888 default: 2889 return "Reserved"; 2890 } 2891 case DP_COLORIMETRY_BT2020_YCC: 2892 switch (pixelformat) { 2893 case DP_PIXELFORMAT_YUV444: 2894 case DP_PIXELFORMAT_YUV422: 2895 case DP_PIXELFORMAT_YUV420: 2896 return "BT.2020 YCC"; 2897 default: 2898 return "Reserved"; 2899 } 2900 default: 2901 return "Invalid"; 2902 } 2903 } 2904 2905 static const char *dp_dynamic_range_get_name(enum dp_dynamic_range dynamic_range) 2906 { 2907 switch (dynamic_range) { 2908 case DP_DYNAMIC_RANGE_VESA: 2909 return "VESA range"; 2910 case DP_DYNAMIC_RANGE_CTA: 2911 return "CTA range"; 2912 default: 2913 return "Invalid"; 2914 } 2915 } 2916 2917 static const char *dp_content_type_get_name(enum dp_content_type content_type) 2918 { 2919 switch (content_type) { 2920 case DP_CONTENT_TYPE_NOT_DEFINED: 2921 return "Not defined"; 2922 case DP_CONTENT_TYPE_GRAPHICS: 2923 return "Graphics"; 2924 case DP_CONTENT_TYPE_PHOTO: 2925 return "Photo"; 2926 case DP_CONTENT_TYPE_VIDEO: 2927 return "Video"; 2928 case DP_CONTENT_TYPE_GAME: 2929 return "Game"; 2930 default: 2931 return "Reserved"; 2932 } 2933 } 2934 2935 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc) 2936 { 2937 drm_printf(p, "DP SDP: VSC, revision %u, length %u\n", 2938 vsc->revision, vsc->length); 2939 drm_printf(p, " pixelformat: %s\n", 2940 dp_pixelformat_get_name(vsc->pixelformat)); 2941 drm_printf(p, " colorimetry: %s\n", 2942 dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry)); 2943 drm_printf(p, " bpc: %u\n", vsc->bpc); 2944 drm_printf(p, " dynamic range: %s\n", 2945 dp_dynamic_range_get_name(vsc->dynamic_range)); 2946 drm_printf(p, " content type: %s\n", 2947 dp_content_type_get_name(vsc->content_type)); 2948 } 2949 EXPORT_SYMBOL(drm_dp_vsc_sdp_log); 2950 2951 /** 2952 * drm_dp_vsc_sdp_supported() - check if vsc sdp is supported 2953 * @aux: DisplayPort AUX channel 2954 * @dpcd: DisplayPort configuration data 2955 * 2956 * Returns true if vsc sdp is supported, else returns false 2957 */ 2958 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 2959 { 2960 u8 rx_feature; 2961 2962 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_13) 2963 return false; 2964 2965 if (drm_dp_dpcd_readb(aux, DP_DPRX_FEATURE_ENUMERATION_LIST, &rx_feature) != 1) { 2966 drm_dbg_dp(aux->drm_dev, "failed to read DP_DPRX_FEATURE_ENUMERATION_LIST\n"); 2967 return false; 2968 } 2969 2970 return (rx_feature & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED); 2971 } 2972 EXPORT_SYMBOL(drm_dp_vsc_sdp_supported); 2973 2974 /** 2975 * drm_dp_vsc_sdp_pack() - pack a given vsc sdp into generic dp_sdp 2976 * @vsc: vsc sdp initialized according to its purpose as defined in 2977 * table 2-118 - table 2-120 in DP 1.4a specification 2978 * @sdp: valid handle to the generic dp_sdp which will be packed 2979 * 2980 * Returns length of sdp on success and error code on failure 2981 */ 2982 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, 2983 struct dp_sdp *sdp) 2984 { 2985 size_t length = sizeof(struct dp_sdp); 2986 2987 memset(sdp, 0, sizeof(struct dp_sdp)); 2988 2989 /* 2990 * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119 2991 * VSC SDP Header Bytes 2992 */ 2993 sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */ 2994 sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */ 2995 sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */ 2996 sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */ 2997 2998 if (vsc->revision == 0x6) { 2999 sdp->db[0] = 1; 3000 sdp->db[3] = 1; 3001 } 3002 3003 /* 3004 * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry 3005 * Format as per DP 1.4a spec and DP 2.0 respectively. 3006 */ 3007 if (!(vsc->revision == 0x5 || vsc->revision == 0x7)) 3008 goto out; 3009 3010 /* VSC SDP Payload for DB16 through DB18 */ 3011 /* Pixel Encoding and Colorimetry Formats */ 3012 sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */ 3013 sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */ 3014 3015 switch (vsc->bpc) { 3016 case 6: 3017 /* 6bpc: 0x0 */ 3018 break; 3019 case 8: 3020 sdp->db[17] = 0x1; /* DB17[3:0] */ 3021 break; 3022 case 10: 3023 sdp->db[17] = 0x2; 3024 break; 3025 case 12: 3026 sdp->db[17] = 0x3; 3027 break; 3028 case 16: 3029 sdp->db[17] = 0x4; 3030 break; 3031 default: 3032 WARN(1, "Missing case %d\n", vsc->bpc); 3033 return -EINVAL; 3034 } 3035 3036 /* Dynamic Range and Component Bit Depth */ 3037 if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA) 3038 sdp->db[17] |= 0x80; /* DB17[7] */ 3039 3040 /* Content Type */ 3041 sdp->db[18] = vsc->content_type & 0x7; 3042 3043 out: 3044 return length; 3045 } 3046 EXPORT_SYMBOL(drm_dp_vsc_sdp_pack); 3047 3048 /** 3049 * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON 3050 * @dpcd: DisplayPort configuration data 3051 * @port_cap: port capabilities 3052 * 3053 * Returns maximum frl bandwidth supported by PCON in GBPS, 3054 * returns 0 if not supported. 3055 */ 3056 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 3057 const u8 port_cap[4]) 3058 { 3059 int bw; 3060 u8 buf; 3061 3062 buf = port_cap[2]; 3063 bw = buf & DP_PCON_MAX_FRL_BW; 3064 3065 switch (bw) { 3066 case DP_PCON_MAX_9GBPS: 3067 return 9; 3068 case DP_PCON_MAX_18GBPS: 3069 return 18; 3070 case DP_PCON_MAX_24GBPS: 3071 return 24; 3072 case DP_PCON_MAX_32GBPS: 3073 return 32; 3074 case DP_PCON_MAX_40GBPS: 3075 return 40; 3076 case DP_PCON_MAX_48GBPS: 3077 return 48; 3078 case DP_PCON_MAX_0GBPS: 3079 default: 3080 return 0; 3081 } 3082 3083 return 0; 3084 } 3085 EXPORT_SYMBOL(drm_dp_get_pcon_max_frl_bw); 3086 3087 /** 3088 * drm_dp_pcon_frl_prepare() - Prepare PCON for FRL. 3089 * @aux: DisplayPort AUX channel 3090 * @enable_frl_ready_hpd: Configure DP_PCON_ENABLE_HPD_READY. 3091 * 3092 * Returns 0 if success, else returns negative error code. 3093 */ 3094 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd) 3095 { 3096 int ret; 3097 u8 buf = DP_PCON_ENABLE_SOURCE_CTL_MODE | 3098 DP_PCON_ENABLE_LINK_FRL_MODE; 3099 3100 if (enable_frl_ready_hpd) 3101 buf |= DP_PCON_ENABLE_HPD_READY; 3102 3103 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); 3104 3105 return ret; 3106 } 3107 EXPORT_SYMBOL(drm_dp_pcon_frl_prepare); 3108 3109 /** 3110 * drm_dp_pcon_is_frl_ready() - Is PCON ready for FRL 3111 * @aux: DisplayPort AUX channel 3112 * 3113 * Returns true if success, else returns false. 3114 */ 3115 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux) 3116 { 3117 int ret; 3118 u8 buf; 3119 3120 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); 3121 if (ret < 0) 3122 return false; 3123 3124 if (buf & DP_PCON_FRL_READY) 3125 return true; 3126 3127 return false; 3128 } 3129 EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready); 3130 3131 /** 3132 * drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1 3133 * @aux: DisplayPort AUX channel 3134 * @max_frl_gbps: maximum frl bw to be configured between PCON and HDMI sink 3135 * @frl_mode: FRL Training mode, it can be either Concurrent or Sequential. 3136 * In Concurrent Mode, the FRL link bring up can be done along with 3137 * DP Link training. In Sequential mode, the FRL link bring up is done prior to 3138 * the DP Link training. 3139 * 3140 * Returns 0 if success, else returns negative error code. 3141 */ 3142 3143 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps, 3144 u8 frl_mode) 3145 { 3146 int ret; 3147 u8 buf; 3148 3149 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); 3150 if (ret < 0) 3151 return ret; 3152 3153 if (frl_mode == DP_PCON_ENABLE_CONCURRENT_LINK) 3154 buf |= DP_PCON_ENABLE_CONCURRENT_LINK; 3155 else 3156 buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK; 3157 3158 switch (max_frl_gbps) { 3159 case 9: 3160 buf |= DP_PCON_ENABLE_MAX_BW_9GBPS; 3161 break; 3162 case 18: 3163 buf |= DP_PCON_ENABLE_MAX_BW_18GBPS; 3164 break; 3165 case 24: 3166 buf |= DP_PCON_ENABLE_MAX_BW_24GBPS; 3167 break; 3168 case 32: 3169 buf |= DP_PCON_ENABLE_MAX_BW_32GBPS; 3170 break; 3171 case 40: 3172 buf |= DP_PCON_ENABLE_MAX_BW_40GBPS; 3173 break; 3174 case 48: 3175 buf |= DP_PCON_ENABLE_MAX_BW_48GBPS; 3176 break; 3177 case 0: 3178 buf |= DP_PCON_ENABLE_MAX_BW_0GBPS; 3179 break; 3180 default: 3181 return -EINVAL; 3182 } 3183 3184 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); 3185 if (ret < 0) 3186 return ret; 3187 3188 return 0; 3189 } 3190 EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1); 3191 3192 /** 3193 * drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2 3194 * @aux: DisplayPort AUX channel 3195 * @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink 3196 * @frl_type : FRL training type, can be Extended, or Normal. 3197 * In Normal FRL training, the PCON tries each frl bw from the max_frl_mask 3198 * starting from min, and stops when link training is successful. In Extended 3199 * FRL training, all frl bw selected in the mask are trained by the PCON. 3200 * 3201 * Returns 0 if success, else returns negative error code. 3202 */ 3203 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask, 3204 u8 frl_type) 3205 { 3206 int ret; 3207 u8 buf = max_frl_mask; 3208 3209 if (frl_type == DP_PCON_FRL_LINK_TRAIN_EXTENDED) 3210 buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED; 3211 else 3212 buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED; 3213 3214 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf); 3215 if (ret < 0) 3216 return ret; 3217 3218 return 0; 3219 } 3220 EXPORT_SYMBOL(drm_dp_pcon_frl_configure_2); 3221 3222 /** 3223 * drm_dp_pcon_reset_frl_config() - Re-Set HDMI Link configuration. 3224 * @aux: DisplayPort AUX channel 3225 * 3226 * Returns 0 if success, else returns negative error code. 3227 */ 3228 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux) 3229 { 3230 int ret; 3231 3232 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0); 3233 if (ret < 0) 3234 return ret; 3235 3236 return 0; 3237 } 3238 EXPORT_SYMBOL(drm_dp_pcon_reset_frl_config); 3239 3240 /** 3241 * drm_dp_pcon_frl_enable() - Enable HDMI link through FRL 3242 * @aux: DisplayPort AUX channel 3243 * 3244 * Returns 0 if success, else returns negative error code. 3245 */ 3246 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux) 3247 { 3248 int ret; 3249 u8 buf = 0; 3250 3251 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); 3252 if (ret < 0) 3253 return ret; 3254 if (!(buf & DP_PCON_ENABLE_SOURCE_CTL_MODE)) { 3255 drm_dbg_kms(aux->drm_dev, "%s: PCON in Autonomous mode, can't enable FRL\n", 3256 aux->name); 3257 return -EINVAL; 3258 } 3259 buf |= DP_PCON_ENABLE_HDMI_LINK; 3260 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); 3261 if (ret < 0) 3262 return ret; 3263 3264 return 0; 3265 } 3266 EXPORT_SYMBOL(drm_dp_pcon_frl_enable); 3267 3268 /** 3269 * drm_dp_pcon_hdmi_link_active() - check if the PCON HDMI LINK status is active. 3270 * @aux: DisplayPort AUX channel 3271 * 3272 * Returns true if link is active else returns false. 3273 */ 3274 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux) 3275 { 3276 u8 buf; 3277 int ret; 3278 3279 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); 3280 if (ret < 0) 3281 return false; 3282 3283 return buf & DP_PCON_HDMI_TX_LINK_ACTIVE; 3284 } 3285 EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_active); 3286 3287 /** 3288 * drm_dp_pcon_hdmi_link_mode() - get the PCON HDMI LINK MODE 3289 * @aux: DisplayPort AUX channel 3290 * @frl_trained_mask: pointer to store bitmask of the trained bw configuration. 3291 * Valid only if the MODE returned is FRL. For Normal Link training mode 3292 * only 1 of the bits will be set, but in case of Extended mode, more than 3293 * one bits can be set. 3294 * 3295 * Returns the link mode : TMDS or FRL on success, else returns negative error 3296 * code. 3297 */ 3298 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask) 3299 { 3300 u8 buf; 3301 int mode; 3302 int ret; 3303 3304 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_POST_FRL_STATUS, &buf); 3305 if (ret < 0) 3306 return ret; 3307 3308 mode = buf & DP_PCON_HDMI_LINK_MODE; 3309 3310 if (frl_trained_mask && DP_PCON_HDMI_MODE_FRL == mode) 3311 *frl_trained_mask = (buf & DP_PCON_HDMI_FRL_TRAINED_BW) >> 1; 3312 3313 return mode; 3314 } 3315 EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_mode); 3316 3317 /** 3318 * drm_dp_pcon_hdmi_frl_link_error_count() - print the error count per lane 3319 * during link failure between PCON and HDMI sink 3320 * @aux: DisplayPort AUX channel 3321 * @connector: DRM connector 3322 * code. 3323 **/ 3324 3325 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux, 3326 struct drm_connector *connector) 3327 { 3328 u8 buf, error_count; 3329 int i, num_error; 3330 struct drm_hdmi_info *hdmi = &connector->display_info.hdmi; 3331 3332 for (i = 0; i < hdmi->max_lanes; i++) { 3333 if (drm_dp_dpcd_readb(aux, DP_PCON_HDMI_ERROR_STATUS_LN0 + i, &buf) < 0) 3334 return; 3335 3336 error_count = buf & DP_PCON_HDMI_ERROR_COUNT_MASK; 3337 switch (error_count) { 3338 case DP_PCON_HDMI_ERROR_COUNT_HUNDRED_PLUS: 3339 num_error = 100; 3340 break; 3341 case DP_PCON_HDMI_ERROR_COUNT_TEN_PLUS: 3342 num_error = 10; 3343 break; 3344 case DP_PCON_HDMI_ERROR_COUNT_THREE_PLUS: 3345 num_error = 3; 3346 break; 3347 default: 3348 num_error = 0; 3349 } 3350 3351 drm_err(aux->drm_dev, "%s: More than %d errors since the last read for lane %d", 3352 aux->name, num_error, i); 3353 } 3354 } 3355 EXPORT_SYMBOL(drm_dp_pcon_hdmi_frl_link_error_count); 3356 3357 /* 3358 * drm_dp_pcon_enc_is_dsc_1_2 - Does PCON Encoder supports DSC 1.2 3359 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3360 * 3361 * Returns true is PCON encoder is DSC 1.2 else returns false. 3362 */ 3363 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3364 { 3365 u8 buf; 3366 u8 major_v, minor_v; 3367 3368 buf = pcon_dsc_dpcd[DP_PCON_DSC_VERSION - DP_PCON_DSC_ENCODER]; 3369 major_v = (buf & DP_PCON_DSC_MAJOR_MASK) >> DP_PCON_DSC_MAJOR_SHIFT; 3370 minor_v = (buf & DP_PCON_DSC_MINOR_MASK) >> DP_PCON_DSC_MINOR_SHIFT; 3371 3372 if (major_v == 1 && minor_v == 2) 3373 return true; 3374 3375 return false; 3376 } 3377 EXPORT_SYMBOL(drm_dp_pcon_enc_is_dsc_1_2); 3378 3379 /* 3380 * drm_dp_pcon_dsc_max_slices - Get max slices supported by PCON DSC Encoder 3381 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3382 * 3383 * Returns maximum no. of slices supported by the PCON DSC Encoder. 3384 */ 3385 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3386 { 3387 u8 slice_cap1, slice_cap2; 3388 3389 slice_cap1 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_1 - DP_PCON_DSC_ENCODER]; 3390 slice_cap2 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_2 - DP_PCON_DSC_ENCODER]; 3391 3392 if (slice_cap2 & DP_PCON_DSC_24_PER_DSC_ENC) 3393 return 24; 3394 if (slice_cap2 & DP_PCON_DSC_20_PER_DSC_ENC) 3395 return 20; 3396 if (slice_cap2 & DP_PCON_DSC_16_PER_DSC_ENC) 3397 return 16; 3398 if (slice_cap1 & DP_PCON_DSC_12_PER_DSC_ENC) 3399 return 12; 3400 if (slice_cap1 & DP_PCON_DSC_10_PER_DSC_ENC) 3401 return 10; 3402 if (slice_cap1 & DP_PCON_DSC_8_PER_DSC_ENC) 3403 return 8; 3404 if (slice_cap1 & DP_PCON_DSC_6_PER_DSC_ENC) 3405 return 6; 3406 if (slice_cap1 & DP_PCON_DSC_4_PER_DSC_ENC) 3407 return 4; 3408 if (slice_cap1 & DP_PCON_DSC_2_PER_DSC_ENC) 3409 return 2; 3410 if (slice_cap1 & DP_PCON_DSC_1_PER_DSC_ENC) 3411 return 1; 3412 3413 return 0; 3414 } 3415 EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slices); 3416 3417 /* 3418 * drm_dp_pcon_dsc_max_slice_width() - Get max slice width for Pcon DSC encoder 3419 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3420 * 3421 * Returns maximum width of the slices in pixel width i.e. no. of pixels x 320. 3422 */ 3423 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3424 { 3425 u8 buf; 3426 3427 buf = pcon_dsc_dpcd[DP_PCON_DSC_MAX_SLICE_WIDTH - DP_PCON_DSC_ENCODER]; 3428 3429 return buf * DP_DSC_SLICE_WIDTH_MULTIPLIER; 3430 } 3431 EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slice_width); 3432 3433 /* 3434 * drm_dp_pcon_dsc_bpp_incr() - Get bits per pixel increment for PCON DSC encoder 3435 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder 3436 * 3437 * Returns the bpp precision supported by the PCON encoder. 3438 */ 3439 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) 3440 { 3441 u8 buf; 3442 3443 buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER]; 3444 3445 switch (buf & DP_PCON_DSC_BPP_INCR_MASK) { 3446 case DP_PCON_DSC_ONE_16TH_BPP: 3447 return 16; 3448 case DP_PCON_DSC_ONE_8TH_BPP: 3449 return 8; 3450 case DP_PCON_DSC_ONE_4TH_BPP: 3451 return 4; 3452 case DP_PCON_DSC_ONE_HALF_BPP: 3453 return 2; 3454 case DP_PCON_DSC_ONE_BPP: 3455 return 1; 3456 } 3457 3458 return 0; 3459 } 3460 EXPORT_SYMBOL(drm_dp_pcon_dsc_bpp_incr); 3461 3462 static 3463 int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config) 3464 { 3465 u8 buf; 3466 int ret; 3467 3468 ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); 3469 if (ret < 0) 3470 return ret; 3471 3472 buf |= DP_PCON_ENABLE_DSC_ENCODER; 3473 3474 if (pps_buf_config <= DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER) { 3475 buf &= ~DP_PCON_ENCODER_PPS_OVERRIDE_MASK; 3476 buf |= pps_buf_config << 2; 3477 } 3478 3479 ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); 3480 if (ret < 0) 3481 return ret; 3482 3483 return 0; 3484 } 3485 3486 /** 3487 * drm_dp_pcon_pps_default() - Let PCON fill the default pps parameters 3488 * for DSC1.2 between PCON & HDMI2.1 sink 3489 * @aux: DisplayPort AUX channel 3490 * 3491 * Returns 0 on success, else returns negative error code. 3492 */ 3493 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux) 3494 { 3495 int ret; 3496 3497 ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_DISABLED); 3498 if (ret < 0) 3499 return ret; 3500 3501 return 0; 3502 } 3503 EXPORT_SYMBOL(drm_dp_pcon_pps_default); 3504 3505 /** 3506 * drm_dp_pcon_pps_override_buf() - Configure PPS encoder override buffer for 3507 * HDMI sink 3508 * @aux: DisplayPort AUX channel 3509 * @pps_buf: 128 bytes to be written into PPS buffer for HDMI sink by PCON. 3510 * 3511 * Returns 0 on success, else returns negative error code. 3512 */ 3513 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]) 3514 { 3515 int ret; 3516 3517 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVERRIDE_BASE, &pps_buf, 128); 3518 if (ret < 0) 3519 return ret; 3520 3521 ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); 3522 if (ret < 0) 3523 return ret; 3524 3525 return 0; 3526 } 3527 EXPORT_SYMBOL(drm_dp_pcon_pps_override_buf); 3528 3529 /* 3530 * drm_dp_pcon_pps_override_param() - Write PPS parameters to DSC encoder 3531 * override registers 3532 * @aux: DisplayPort AUX channel 3533 * @pps_param: 3 Parameters (2 Bytes each) : Slice Width, Slice Height, 3534 * bits_per_pixel. 3535 * 3536 * Returns 0 on success, else returns negative error code. 3537 */ 3538 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]) 3539 { 3540 int ret; 3541 3542 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_HEIGHT, &pps_param[0], 2); 3543 if (ret < 0) 3544 return ret; 3545 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_WIDTH, &pps_param[2], 2); 3546 if (ret < 0) 3547 return ret; 3548 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_BPP, &pps_param[4], 2); 3549 if (ret < 0) 3550 return ret; 3551 3552 ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); 3553 if (ret < 0) 3554 return ret; 3555 3556 return 0; 3557 } 3558 EXPORT_SYMBOL(drm_dp_pcon_pps_override_param); 3559 3560 /* 3561 * drm_dp_pcon_convert_rgb_to_ycbcr() - Configure the PCon to convert RGB to Ycbcr 3562 * @aux: displayPort AUX channel 3563 * @color_spc: Color-space/s for which conversion is to be enabled, 0 for disable. 3564 * 3565 * Returns 0 on success, else returns negative error code. 3566 */ 3567 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc) 3568 { 3569 int ret; 3570 u8 buf; 3571 3572 ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); 3573 if (ret < 0) 3574 return ret; 3575 3576 if (color_spc & DP_CONVERSION_RGB_YCBCR_MASK) 3577 buf |= (color_spc & DP_CONVERSION_RGB_YCBCR_MASK); 3578 else 3579 buf &= ~DP_CONVERSION_RGB_YCBCR_MASK; 3580 3581 ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); 3582 if (ret < 0) 3583 return ret; 3584 3585 return 0; 3586 } 3587 EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr); 3588 3589 /** 3590 * drm_edp_backlight_set_level() - Set the backlight level of an eDP panel via AUX 3591 * @aux: The DP AUX channel to use 3592 * @bl: Backlight capability info from drm_edp_backlight_init() 3593 * @level: The brightness level to set 3594 * 3595 * Sets the brightness level of an eDP panel's backlight. Note that the panel's backlight must 3596 * already have been enabled by the driver by calling drm_edp_backlight_enable(). 3597 * 3598 * Returns: %0 on success, negative error code on failure 3599 */ 3600 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 3601 u16 level) 3602 { 3603 int ret; 3604 u8 buf[2] = { 0 }; 3605 3606 /* The panel uses the PWM for controlling brightness levels */ 3607 if (!bl->aux_set) 3608 return 0; 3609 3610 if (bl->lsb_reg_used) { 3611 buf[0] = (level & 0xff00) >> 8; 3612 buf[1] = (level & 0x00ff); 3613 } else { 3614 buf[0] = level; 3615 } 3616 3617 ret = drm_dp_dpcd_write(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, sizeof(buf)); 3618 if (ret != sizeof(buf)) { 3619 drm_err(aux->drm_dev, 3620 "%s: Failed to write aux backlight level: %d\n", 3621 aux->name, ret); 3622 return ret < 0 ? ret : -EIO; 3623 } 3624 3625 return 0; 3626 } 3627 EXPORT_SYMBOL(drm_edp_backlight_set_level); 3628 3629 static int 3630 drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 3631 bool enable) 3632 { 3633 int ret; 3634 u8 buf; 3635 3636 /* This panel uses the EDP_BL_PWR GPIO for enablement */ 3637 if (!bl->aux_enable) 3638 return 0; 3639 3640 ret = drm_dp_dpcd_readb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &buf); 3641 if (ret != 1) { 3642 drm_err(aux->drm_dev, "%s: Failed to read eDP display control register: %d\n", 3643 aux->name, ret); 3644 return ret < 0 ? ret : -EIO; 3645 } 3646 if (enable) 3647 buf |= DP_EDP_BACKLIGHT_ENABLE; 3648 else 3649 buf &= ~DP_EDP_BACKLIGHT_ENABLE; 3650 3651 ret = drm_dp_dpcd_writeb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, buf); 3652 if (ret != 1) { 3653 drm_err(aux->drm_dev, "%s: Failed to write eDP display control register: %d\n", 3654 aux->name, ret); 3655 return ret < 0 ? ret : -EIO; 3656 } 3657 3658 return 0; 3659 } 3660 3661 /** 3662 * drm_edp_backlight_enable() - Enable an eDP panel's backlight using DPCD 3663 * @aux: The DP AUX channel to use 3664 * @bl: Backlight capability info from drm_edp_backlight_init() 3665 * @level: The initial backlight level to set via AUX, if there is one 3666 * 3667 * This function handles enabling DPCD backlight controls on a panel over DPCD, while additionally 3668 * restoring any important backlight state such as the given backlight level, the brightness byte 3669 * count, backlight frequency, etc. 3670 * 3671 * Note that certain panels do not support being enabled or disabled via DPCD, but instead require 3672 * that the driver handle enabling/disabling the panel through implementation-specific means using 3673 * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false, 3674 * this function becomes a no-op, and the driver is expected to handle powering the panel on using 3675 * the EDP_BL_PWR GPIO. 3676 * 3677 * Returns: %0 on success, negative error code on failure. 3678 */ 3679 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 3680 const u16 level) 3681 { 3682 int ret; 3683 u8 dpcd_buf; 3684 3685 if (bl->aux_set) 3686 dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; 3687 else 3688 dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_PWM; 3689 3690 if (bl->pwmgen_bit_count) { 3691 ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count); 3692 if (ret != 1) 3693 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n", 3694 aux->name, ret); 3695 } 3696 3697 if (bl->pwm_freq_pre_divider) { 3698 ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_FREQ_SET, bl->pwm_freq_pre_divider); 3699 if (ret != 1) 3700 drm_dbg_kms(aux->drm_dev, 3701 "%s: Failed to write aux backlight frequency: %d\n", 3702 aux->name, ret); 3703 else 3704 dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; 3705 } 3706 3707 ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf); 3708 if (ret != 1) { 3709 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux backlight mode: %d\n", 3710 aux->name, ret); 3711 return ret < 0 ? ret : -EIO; 3712 } 3713 3714 ret = drm_edp_backlight_set_level(aux, bl, level); 3715 if (ret < 0) 3716 return ret; 3717 ret = drm_edp_backlight_set_enable(aux, bl, true); 3718 if (ret < 0) 3719 return ret; 3720 3721 return 0; 3722 } 3723 EXPORT_SYMBOL(drm_edp_backlight_enable); 3724 3725 /** 3726 * drm_edp_backlight_disable() - Disable an eDP backlight using DPCD, if supported 3727 * @aux: The DP AUX channel to use 3728 * @bl: Backlight capability info from drm_edp_backlight_init() 3729 * 3730 * This function handles disabling DPCD backlight controls on a panel over AUX. 3731 * 3732 * Note that certain panels do not support being enabled or disabled via DPCD, but instead require 3733 * that the driver handle enabling/disabling the panel through implementation-specific means using 3734 * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false, 3735 * this function becomes a no-op, and the driver is expected to handle powering the panel off using 3736 * the EDP_BL_PWR GPIO. 3737 * 3738 * Returns: %0 on success or no-op, negative error code on failure. 3739 */ 3740 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl) 3741 { 3742 int ret; 3743 3744 ret = drm_edp_backlight_set_enable(aux, bl, false); 3745 if (ret < 0) 3746 return ret; 3747 3748 return 0; 3749 } 3750 EXPORT_SYMBOL(drm_edp_backlight_disable); 3751 3752 static inline int 3753 drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 3754 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) 3755 { 3756 int fxp, fxp_min, fxp_max, fxp_actual, f = 1; 3757 int ret; 3758 u8 pn, pn_min, pn_max; 3759 3760 if (!bl->aux_set) 3761 return 0; 3762 3763 ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT, &pn); 3764 if (ret != 1) { 3765 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap: %d\n", 3766 aux->name, ret); 3767 return -ENODEV; 3768 } 3769 3770 pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK; 3771 bl->max = (1 << pn) - 1; 3772 if (!driver_pwm_freq_hz) 3773 return 0; 3774 3775 /* 3776 * Set PWM Frequency divider to match desired frequency provided by the driver. 3777 * The PWM Frequency is calculated as 27Mhz / (F x P). 3778 * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the 3779 * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) 3780 * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the 3781 * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) 3782 */ 3783 3784 /* Find desired value of (F x P) 3785 * Note that, if F x P is out of supported range, the maximum value or minimum value will 3786 * applied automatically. So no need to check that. 3787 */ 3788 fxp = DIV_ROUND_CLOSEST(1000 * DP_EDP_BACKLIGHT_FREQ_BASE_KHZ, driver_pwm_freq_hz); 3789 3790 /* Use highest possible value of Pn for more granularity of brightness adjustment while 3791 * satisfying the conditions below. 3792 * - Pn is in the range of Pn_min and Pn_max 3793 * - F is in the range of 1 and 255 3794 * - FxP is within 25% of desired value. 3795 * Note: 25% is arbitrary value and may need some tweak. 3796 */ 3797 ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min); 3798 if (ret != 1) { 3799 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap min: %d\n", 3800 aux->name, ret); 3801 return 0; 3802 } 3803 ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max); 3804 if (ret != 1) { 3805 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap max: %d\n", 3806 aux->name, ret); 3807 return 0; 3808 } 3809 pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; 3810 pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; 3811 3812 /* Ensure frequency is within 25% of desired value */ 3813 fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); 3814 fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); 3815 if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { 3816 drm_dbg_kms(aux->drm_dev, 3817 "%s: Driver defined backlight frequency (%d) out of range\n", 3818 aux->name, driver_pwm_freq_hz); 3819 return 0; 3820 } 3821 3822 for (pn = pn_max; pn >= pn_min; pn--) { 3823 f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); 3824 fxp_actual = f << pn; 3825 if (fxp_min <= fxp_actual && fxp_actual <= fxp_max) 3826 break; 3827 } 3828 3829 ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, pn); 3830 if (ret != 1) { 3831 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n", 3832 aux->name, ret); 3833 return 0; 3834 } 3835 bl->pwmgen_bit_count = pn; 3836 bl->max = (1 << pn) - 1; 3837 3838 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) { 3839 bl->pwm_freq_pre_divider = f; 3840 drm_dbg_kms(aux->drm_dev, "%s: Using backlight frequency from driver (%dHz)\n", 3841 aux->name, driver_pwm_freq_hz); 3842 } 3843 3844 return 0; 3845 } 3846 3847 static inline int 3848 drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 3849 u8 *current_mode) 3850 { 3851 int ret; 3852 u8 buf[2]; 3853 u8 mode_reg; 3854 3855 ret = drm_dp_dpcd_readb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg); 3856 if (ret != 1) { 3857 drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight mode: %d\n", 3858 aux->name, ret); 3859 return ret < 0 ? ret : -EIO; 3860 } 3861 3862 *current_mode = (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK); 3863 if (!bl->aux_set) 3864 return 0; 3865 3866 if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { 3867 int size = 1 + bl->lsb_reg_used; 3868 3869 ret = drm_dp_dpcd_read(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, size); 3870 if (ret != size) { 3871 drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight level: %d\n", 3872 aux->name, ret); 3873 return ret < 0 ? ret : -EIO; 3874 } 3875 3876 if (bl->lsb_reg_used) 3877 return (buf[0] << 8) | buf[1]; 3878 else 3879 return buf[0]; 3880 } 3881 3882 /* 3883 * If we're not in DPCD control mode yet, the programmed brightness value is meaningless and 3884 * the driver should assume max brightness 3885 */ 3886 return bl->max; 3887 } 3888 3889 /** 3890 * drm_edp_backlight_init() - Probe a display panel's TCON using the standard VESA eDP backlight 3891 * interface. 3892 * @aux: The DP aux device to use for probing 3893 * @bl: The &drm_edp_backlight_info struct to fill out with information on the backlight 3894 * @driver_pwm_freq_hz: Optional PWM frequency from the driver in hz 3895 * @edp_dpcd: A cached copy of the eDP DPCD 3896 * @current_level: Where to store the probed brightness level, if any 3897 * @current_mode: Where to store the currently set backlight control mode 3898 * 3899 * Initializes a &drm_edp_backlight_info struct by probing @aux for it's backlight capabilities, 3900 * along with also probing the current and maximum supported brightness levels. 3901 * 3902 * If @driver_pwm_freq_hz is non-zero, this will be used as the backlight frequency. Otherwise, the 3903 * default frequency from the panel is used. 3904 * 3905 * Returns: %0 on success, negative error code on failure. 3906 */ 3907 int 3908 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 3909 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE], 3910 u16 *current_level, u8 *current_mode) 3911 { 3912 int ret; 3913 3914 if (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) 3915 bl->aux_enable = true; 3916 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) 3917 bl->aux_set = true; 3918 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) 3919 bl->lsb_reg_used = true; 3920 3921 /* Sanity check caps */ 3922 if (!bl->aux_set && !(edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) { 3923 drm_dbg_kms(aux->drm_dev, 3924 "%s: Panel supports neither AUX or PWM brightness control? Aborting\n", 3925 aux->name); 3926 return -EINVAL; 3927 } 3928 3929 ret = drm_edp_backlight_probe_max(aux, bl, driver_pwm_freq_hz, edp_dpcd); 3930 if (ret < 0) 3931 return ret; 3932 3933 ret = drm_edp_backlight_probe_state(aux, bl, current_mode); 3934 if (ret < 0) 3935 return ret; 3936 *current_level = ret; 3937 3938 drm_dbg_kms(aux->drm_dev, 3939 "%s: Found backlight: aux_set=%d aux_enable=%d mode=%d\n", 3940 aux->name, bl->aux_set, bl->aux_enable, *current_mode); 3941 if (bl->aux_set) { 3942 drm_dbg_kms(aux->drm_dev, 3943 "%s: Backlight caps: level=%d/%d pwm_freq_pre_divider=%d lsb_reg_used=%d\n", 3944 aux->name, *current_level, bl->max, bl->pwm_freq_pre_divider, 3945 bl->lsb_reg_used); 3946 } 3947 3948 return 0; 3949 } 3950 EXPORT_SYMBOL(drm_edp_backlight_init); 3951 3952 #if IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \ 3953 (IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)) 3954 3955 static int dp_aux_backlight_update_status(struct backlight_device *bd) 3956 { 3957 struct dp_aux_backlight *bl = bl_get_data(bd); 3958 u16 brightness = backlight_get_brightness(bd); 3959 int ret = 0; 3960 3961 if (!backlight_is_blank(bd)) { 3962 if (!bl->enabled) { 3963 drm_edp_backlight_enable(bl->aux, &bl->info, brightness); 3964 bl->enabled = true; 3965 return 0; 3966 } 3967 ret = drm_edp_backlight_set_level(bl->aux, &bl->info, brightness); 3968 } else { 3969 if (bl->enabled) { 3970 drm_edp_backlight_disable(bl->aux, &bl->info); 3971 bl->enabled = false; 3972 } 3973 } 3974 3975 return ret; 3976 } 3977 3978 static const struct backlight_ops dp_aux_bl_ops = { 3979 .update_status = dp_aux_backlight_update_status, 3980 }; 3981 3982 /** 3983 * drm_panel_dp_aux_backlight - create and use DP AUX backlight 3984 * @panel: DRM panel 3985 * @aux: The DP AUX channel to use 3986 * 3987 * Use this function to create and handle backlight if your panel 3988 * supports backlight control over DP AUX channel using DPCD 3989 * registers as per VESA's standard backlight control interface. 3990 * 3991 * When the panel is enabled backlight will be enabled after a 3992 * successful call to &drm_panel_funcs.enable() 3993 * 3994 * When the panel is disabled backlight will be disabled before the 3995 * call to &drm_panel_funcs.disable(). 3996 * 3997 * A typical implementation for a panel driver supporting backlight 3998 * control over DP AUX will call this function at probe time. 3999 * Backlight will then be handled transparently without requiring 4000 * any intervention from the driver. 4001 * 4002 * drm_panel_dp_aux_backlight() must be called after the call to drm_panel_init(). 4003 * 4004 * Return: 0 on success or a negative error code on failure. 4005 */ 4006 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux) 4007 { 4008 struct dp_aux_backlight *bl; 4009 struct backlight_properties props = { 0 }; 4010 u16 current_level; 4011 u8 current_mode; 4012 u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; 4013 int ret; 4014 4015 if (!panel || !panel->dev || !aux) 4016 return -EINVAL; 4017 4018 ret = drm_dp_dpcd_read(aux, DP_EDP_DPCD_REV, edp_dpcd, 4019 EDP_DISPLAY_CTL_CAP_SIZE); 4020 if (ret < 0) 4021 return ret; 4022 4023 if (!drm_edp_backlight_supported(edp_dpcd)) { 4024 DRM_DEV_INFO(panel->dev, "DP AUX backlight is not supported\n"); 4025 return 0; 4026 } 4027 4028 bl = devm_kzalloc(panel->dev, sizeof(*bl), GFP_KERNEL); 4029 if (!bl) 4030 return -ENOMEM; 4031 4032 bl->aux = aux; 4033 4034 ret = drm_edp_backlight_init(aux, &bl->info, 0, edp_dpcd, 4035 ¤t_level, ¤t_mode); 4036 if (ret < 0) 4037 return ret; 4038 4039 props.type = BACKLIGHT_RAW; 4040 props.brightness = current_level; 4041 props.max_brightness = bl->info.max; 4042 4043 bl->base = devm_backlight_device_register(panel->dev, "dp_aux_backlight", 4044 panel->dev, bl, 4045 &dp_aux_bl_ops, &props); 4046 if (IS_ERR(bl->base)) 4047 return PTR_ERR(bl->base); 4048 4049 backlight_disable(bl->base); 4050 4051 panel->backlight = bl->base; 4052 4053 return 0; 4054 } 4055 EXPORT_SYMBOL(drm_panel_dp_aux_backlight); 4056 4057 #endif 4058 4059 /* See DP Standard v2.1 2.6.4.4.1.1, 2.8.4.4, 2.8.7 */ 4060 static int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, 4061 int symbol_size, bool is_mst) 4062 { 4063 int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); 4064 int align = is_mst ? 4 / lane_count : 1; 4065 4066 return ALIGN(cycles, align); 4067 } 4068 4069 static int drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_count, 4070 int bpp_x16, int symbol_size, bool is_mst) 4071 { 4072 int slice_pixels = DIV_ROUND_UP(pixels, slice_count); 4073 int slice_data_cycles = drm_dp_link_symbol_cycles(lane_count, slice_pixels, 4074 bpp_x16, symbol_size, is_mst); 4075 int slice_eoc_cycles = is_mst ? 4 / lane_count : 1; 4076 4077 return slice_count * (slice_data_cycles + slice_eoc_cycles); 4078 } 4079 4080 /** 4081 * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream 4082 * @lane_count: DP link lane count 4083 * @hactive: pixel count of the active period in one scanline of the stream 4084 * @dsc_slice_count: DSC slice count if @flags/DRM_DP_LINK_BW_OVERHEAD_DSC is set 4085 * @bpp_x16: bits per pixel in .4 binary fixed point 4086 * @flags: DRM_DP_OVERHEAD_x flags 4087 * 4088 * Calculate the BW allocation overhead of a DP link stream, depending 4089 * on the link's 4090 * - @lane_count 4091 * - SST/MST mode (@flags / %DRM_DP_OVERHEAD_MST) 4092 * - symbol size (@flags / %DRM_DP_OVERHEAD_UHBR) 4093 * - FEC mode (@flags / %DRM_DP_OVERHEAD_FEC) 4094 * - SSC/REF_CLK mode (@flags / %DRM_DP_OVERHEAD_SSC_REF_CLK) 4095 * as well as the stream's 4096 * - @hactive timing 4097 * - @bpp_x16 color depth 4098 * - compression mode (@flags / %DRM_DP_OVERHEAD_DSC). 4099 * Note that this overhead doesn't account for the 8b/10b, 128b/132b 4100 * channel coding efficiency, for that see 4101 * @drm_dp_link_bw_channel_coding_efficiency(). 4102 * 4103 * Returns the overhead as 100% + overhead% in 1ppm units. 4104 */ 4105 int drm_dp_bw_overhead(int lane_count, int hactive, 4106 int dsc_slice_count, 4107 int bpp_x16, unsigned long flags) 4108 { 4109 int symbol_size = flags & DRM_DP_BW_OVERHEAD_UHBR ? 32 : 8; 4110 bool is_mst = flags & DRM_DP_BW_OVERHEAD_MST; 4111 u32 overhead = 1000000; 4112 int symbol_cycles; 4113 4114 /* 4115 * DP Standard v2.1 2.6.4.1 4116 * SSC downspread and ref clock variation margin: 4117 * 5300ppm + 300ppm ~ 0.6% 4118 */ 4119 if (flags & DRM_DP_BW_OVERHEAD_SSC_REF_CLK) 4120 overhead += 6000; 4121 4122 /* 4123 * DP Standard v2.1 2.6.4.1.1, 3.5.1.5.4: 4124 * FEC symbol insertions for 8b/10b channel coding: 4125 * After each 250 data symbols on 2-4 lanes: 4126 * 250 LL + 5 FEC_PARITY_PH + 1 CD_ADJ (256 byte FEC block) 4127 * After each 2 x 250 data symbols on 1 lane: 4128 * 2 * 250 LL + 11 FEC_PARITY_PH + 1 CD_ADJ (512 byte FEC block) 4129 * After 256 (2-4 lanes) or 128 (1 lane) FEC blocks: 4130 * 256 * 256 bytes + 1 FEC_PM 4131 * or 4132 * 128 * 512 bytes + 1 FEC_PM 4133 * (256 * 6 + 1) / (256 * 250) = 2.4015625 % 4134 */ 4135 if (flags & DRM_DP_BW_OVERHEAD_FEC) 4136 overhead += 24016; 4137 4138 /* 4139 * DP Standard v2.1 2.7.9, 5.9.7 4140 * The FEC overhead for UHBR is accounted for in its 96.71% channel 4141 * coding efficiency. 4142 */ 4143 WARN_ON((flags & DRM_DP_BW_OVERHEAD_UHBR) && 4144 (flags & DRM_DP_BW_OVERHEAD_FEC)); 4145 4146 if (flags & DRM_DP_BW_OVERHEAD_DSC) 4147 symbol_cycles = drm_dp_link_dsc_symbol_cycles(lane_count, hactive, 4148 dsc_slice_count, 4149 bpp_x16, symbol_size, 4150 is_mst); 4151 else 4152 symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, 4153 bpp_x16, symbol_size, 4154 is_mst); 4155 4156 return DIV_ROUND_UP_ULL(mul_u32_u32(symbol_cycles * symbol_size * lane_count, 4157 overhead * 16), 4158 hactive * bpp_x16); 4159 } 4160 EXPORT_SYMBOL(drm_dp_bw_overhead); 4161 4162 /** 4163 * drm_dp_bw_channel_coding_efficiency - Get a DP link's channel coding efficiency 4164 * @is_uhbr: Whether the link has a 128b/132b channel coding 4165 * 4166 * Return the channel coding efficiency of the given DP link type, which is 4167 * either 8b/10b or 128b/132b (aka UHBR). The corresponding overhead includes 4168 * the 8b -> 10b, 128b -> 132b pixel data to link symbol conversion overhead 4169 * and for 128b/132b any link or PHY level control symbol insertion overhead 4170 * (LLCP, FEC, PHY sync, see DP Standard v2.1 3.5.2.18). For 8b/10b the 4171 * corresponding FEC overhead is BW allocation specific, included in the value 4172 * returned by drm_dp_bw_overhead(). 4173 * 4174 * Returns the efficiency in the 100%/coding-overhead% ratio in 4175 * 1ppm units. 4176 */ 4177 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr) 4178 { 4179 if (is_uhbr) 4180 return 967100; 4181 else 4182 /* 4183 * Note that on 8b/10b MST the efficiency is only 4184 * 78.75% due to the 1 out of 64 MTPH packet overhead, 4185 * not accounted for here. 4186 */ 4187 return 800000; 4188 } 4189 EXPORT_SYMBOL(drm_dp_bw_channel_coding_efficiency); 4190 4191 /** 4192 * drm_dp_max_dprx_data_rate - Get the max data bandwidth of a DPRX sink 4193 * @max_link_rate: max DPRX link rate in 10kbps units 4194 * @max_lanes: max DPRX lane count 4195 * 4196 * Given a link rate and lanes, get the data bandwidth. 4197 * 4198 * Data bandwidth is the actual payload rate, which depends on the data 4199 * bandwidth efficiency and the link rate. 4200 * 4201 * Note that protocol layers above the DPRX link level considered here can 4202 * further limit the maximum data rate. Such layers are the MST topology (with 4203 * limits on the link between the source and first branch device as well as on 4204 * the whole MST path until the DPRX link) and (Thunderbolt) DP tunnels - 4205 * which in turn can encapsulate an MST link with its own limit - with each 4206 * SST or MST encapsulated tunnel sharing the BW of a tunnel group. 4207 * 4208 * Returns the maximum data rate in kBps units. 4209 */ 4210 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes) 4211 { 4212 int ch_coding_efficiency = 4213 drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(max_link_rate)); 4214 4215 return DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate * 10 * max_lanes, 4216 ch_coding_efficiency), 4217 1000000 * 8); 4218 } 4219 EXPORT_SYMBOL(drm_dp_max_dprx_data_rate); 4220