1 /* 2 * Copyright © 2008 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 #ifndef _DRM_DP_HELPER_H_ 24 #define _DRM_DP_HELPER_H_ 25 26 #include <linux/delay.h> 27 #include <linux/i2c.h> 28 29 #include <drm/display/drm_dp.h> 30 #include <drm/drm_connector.h> 31 32 struct drm_device; 33 struct drm_dp_aux; 34 struct drm_panel; 35 36 bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], 37 int lane_count); 38 bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], 39 int lane_count); 40 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], 41 int lane); 42 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], 43 int lane); 44 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE], 45 int lane); 46 47 int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 48 enum drm_dp_phy dp_phy, bool uhbr); 49 int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], 50 enum drm_dp_phy dp_phy, bool uhbr); 51 52 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux, 53 const u8 dpcd[DP_RECEIVER_CAP_SIZE]); 54 void drm_dp_lttpr_link_train_clock_recovery_delay(void); 55 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 56 const u8 dpcd[DP_RECEIVER_CAP_SIZE]); 57 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, 58 const u8 caps[DP_LTTPR_PHY_CAP_SIZE]); 59 60 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux); 61 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE], 62 int lane_count); 63 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE], 64 int lane_count); 65 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]); 66 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]); 67 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]); 68 69 u8 drm_dp_link_rate_to_bw_code(int link_rate); 70 int drm_dp_bw_code_to_link_rate(u8 link_bw); 71 72 const char *drm_dp_phy_name(enum drm_dp_phy dp_phy); 73 74 /** 75 * struct drm_dp_vsc_sdp - drm DP VSC SDP 76 * 77 * This structure represents a DP VSC SDP of drm 78 * It is based on DP 1.4 spec [Table 2-116: VSC SDP Header Bytes] and 79 * [Table 2-117: VSC SDP Payload for DB16 through DB18] 80 * 81 * @sdp_type: secondary-data packet type 82 * @revision: revision number 83 * @length: number of valid data bytes 84 * @pixelformat: pixel encoding format 85 * @colorimetry: colorimetry format 86 * @bpc: bit per color 87 * @dynamic_range: dynamic range information 88 * @content_type: CTA-861-G defines content types and expected processing by a sink device 89 */ 90 struct drm_dp_vsc_sdp { 91 unsigned char sdp_type; 92 unsigned char revision; 93 unsigned char length; 94 enum dp_pixelformat pixelformat; 95 enum dp_colorimetry colorimetry; 96 int bpc; 97 enum dp_dynamic_range dynamic_range; 98 enum dp_content_type content_type; 99 }; 100 101 /** 102 * struct drm_dp_as_sdp - drm DP Adaptive Sync SDP 103 * 104 * This structure represents a DP AS SDP of drm 105 * It is based on DP 2.1 spec [Table 2-126: Adaptive-Sync SDP Header Bytes] and 106 * [Table 2-127: Adaptive-Sync SDP Payload for DB0 through DB8] 107 * 108 * @sdp_type: Secondary-data packet type 109 * @revision: Revision Number 110 * @length: Number of valid data bytes 111 * @vtotal: Minimum Vertical Vtotal 112 * @target_rr: Target Refresh 113 * @duration_incr_ms: Successive frame duration increase 114 * @duration_decr_ms: Successive frame duration decrease 115 * @target_rr_divider: Target refresh rate divider 116 * @mode: Adaptive Sync Operation Mode 117 */ 118 struct drm_dp_as_sdp { 119 unsigned char sdp_type; 120 unsigned char revision; 121 unsigned char length; 122 int vtotal; 123 int target_rr; 124 int duration_incr_ms; 125 int duration_decr_ms; 126 bool target_rr_divider; 127 enum operation_mode mode; 128 }; 129 130 void drm_dp_as_sdp_log(struct drm_printer *p, 131 const struct drm_dp_as_sdp *as_sdp); 132 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc); 133 134 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]); 135 bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]); 136 137 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]); 138 139 static inline int 140 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 141 { 142 return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]); 143 } 144 145 static inline u8 146 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 147 { 148 return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK; 149 } 150 151 static inline bool 152 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 153 { 154 return dpcd[DP_DPCD_REV] >= 0x11 && 155 (dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP); 156 } 157 158 static inline bool 159 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 160 { 161 return dpcd[DP_DPCD_REV] >= 0x11 && 162 (dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING); 163 } 164 165 static inline bool 166 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 167 { 168 return dpcd[DP_DPCD_REV] >= 0x12 && 169 dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED; 170 } 171 172 static inline bool 173 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 174 { 175 return dpcd[DP_DPCD_REV] >= 0x11 || 176 dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5; 177 } 178 179 static inline bool 180 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 181 { 182 return dpcd[DP_DPCD_REV] >= 0x14 && 183 dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED; 184 } 185 186 static inline u8 187 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 188 { 189 return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 : 190 DP_TRAINING_PATTERN_MASK; 191 } 192 193 static inline bool 194 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 195 { 196 return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT; 197 } 198 199 /* DP/eDP DSC support */ 200 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]); 201 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 202 bool is_edp); 203 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]); 204 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE], 205 u8 dsc_bpc[3]); 206 207 static inline bool 208 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 209 { 210 return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] & 211 DP_DSC_DECOMPRESSION_IS_SUPPORTED; 212 } 213 214 static inline u16 215 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 216 { 217 return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] | 218 ((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] & 219 DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8); 220 } 221 222 static inline u32 223 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) 224 { 225 /* Max Slicewidth = Number of Pixels * 320 */ 226 return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] * 227 DP_DSC_SLICE_WIDTH_MULTIPLIER; 228 } 229 230 /** 231 * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format 232 * @dsc_dpcd : DSC-capability DPCDs of the sink 233 * @output_format: output_format which is to be checked 234 * 235 * Returns true if the sink supports DSC with the given output_format, false otherwise. 236 */ 237 static inline bool 238 drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format) 239 { 240 return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format; 241 } 242 243 /* Forward Error Correction Support on DP 1.4 */ 244 static inline bool 245 drm_dp_sink_supports_fec(const u8 fec_capable) 246 { 247 return fec_capable & DP_FEC_CAPABLE; 248 } 249 250 static inline bool 251 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 252 { 253 return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B; 254 } 255 256 static inline bool 257 drm_dp_128b132b_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 258 { 259 return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_128B132B; 260 } 261 262 static inline bool 263 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 264 { 265 return dpcd[DP_EDP_CONFIGURATION_CAP] & 266 DP_ALTERNATE_SCRAMBLER_RESET_CAP; 267 } 268 269 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */ 270 static inline bool 271 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 272 { 273 return dpcd[DP_DOWN_STREAM_PORT_COUNT] & 274 DP_MSA_TIMING_PAR_IGNORED; 275 } 276 277 /** 278 * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support 279 * @edp_dpcd: The DPCD to check 280 * 281 * Note that currently this function will return %false for panels which support various DPCD 282 * backlight features but which require the brightness be set through PWM, and don't support setting 283 * the brightness level via the DPCD. 284 * 285 * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false 286 * otherwise 287 */ 288 static inline bool 289 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) 290 { 291 return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP); 292 } 293 294 /** 295 * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR 296 * @link_rate: link rate in 10kbits/s units 297 * 298 * Determine if the provided link rate is an UHBR rate. 299 * 300 * Returns: %True if @link_rate is an UHBR rate. 301 */ 302 static inline bool drm_dp_is_uhbr_rate(int link_rate) 303 { 304 return link_rate >= 1000000; 305 } 306 307 /* 308 * DisplayPort AUX channel 309 */ 310 311 /** 312 * struct drm_dp_aux_msg - DisplayPort AUX channel transaction 313 * @address: address of the (first) register to access 314 * @request: contains the type of transaction (see DP_AUX_* macros) 315 * @reply: upon completion, contains the reply type of the transaction 316 * @buffer: pointer to a transmission or reception buffer 317 * @size: size of @buffer 318 */ 319 struct drm_dp_aux_msg { 320 unsigned int address; 321 u8 request; 322 u8 reply; 323 void *buffer; 324 size_t size; 325 }; 326 327 struct cec_adapter; 328 struct drm_connector; 329 struct drm_edid; 330 331 /** 332 * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX 333 * @lock: mutex protecting this struct 334 * @adap: the CEC adapter for CEC-Tunneling-over-AUX support. 335 * @connector: the connector this CEC adapter is associated with 336 * @unregister_work: unregister the CEC adapter 337 */ 338 struct drm_dp_aux_cec { 339 struct mutex lock; 340 struct cec_adapter *adap; 341 struct drm_connector *connector; 342 struct delayed_work unregister_work; 343 }; 344 345 /** 346 * struct drm_dp_aux - DisplayPort AUX channel 347 * 348 * An AUX channel can also be used to transport I2C messages to a sink. A 349 * typical application of that is to access an EDID that's present in the sink 350 * device. The @transfer() function can also be used to execute such 351 * transactions. The drm_dp_aux_register() function registers an I2C adapter 352 * that can be passed to drm_probe_ddc(). Upon removal, drivers should call 353 * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long 354 * transfers by default; if a partial response is received, the adapter will 355 * drop down to the size given by the partial response for this transaction 356 * only. 357 */ 358 struct drm_dp_aux { 359 /** 360 * @name: user-visible name of this AUX channel and the 361 * I2C-over-AUX adapter. 362 * 363 * It's also used to specify the name of the I2C adapter. If set 364 * to %NULL, dev_name() of @dev will be used. 365 */ 366 const char *name; 367 368 /** 369 * @ddc: I2C adapter that can be used for I2C-over-AUX 370 * communication 371 */ 372 struct i2c_adapter ddc; 373 374 /** 375 * @dev: pointer to struct device that is the parent for this 376 * AUX channel. 377 */ 378 struct device *dev; 379 380 /** 381 * @drm_dev: pointer to the &drm_device that owns this AUX channel. 382 * Beware, this may be %NULL before drm_dp_aux_register() has been 383 * called. 384 * 385 * It should be set to the &drm_device that will be using this AUX 386 * channel as early as possible. For many graphics drivers this should 387 * happen before drm_dp_aux_init(), however it's perfectly fine to set 388 * this field later so long as it's assigned before calling 389 * drm_dp_aux_register(). 390 */ 391 struct drm_device *drm_dev; 392 393 /** 394 * @crtc: backpointer to the crtc that is currently using this 395 * AUX channel 396 */ 397 struct drm_crtc *crtc; 398 399 /** 400 * @hw_mutex: internal mutex used for locking transfers. 401 * 402 * Note that if the underlying hardware is shared among multiple 403 * channels, the driver needs to do additional locking to 404 * prevent concurrent access. 405 */ 406 struct mutex hw_mutex; 407 408 /** 409 * @crc_work: worker that captures CRCs for each frame 410 */ 411 struct work_struct crc_work; 412 413 /** 414 * @crc_count: counter of captured frame CRCs 415 */ 416 u8 crc_count; 417 418 /** 419 * @transfer: transfers a message representing a single AUX 420 * transaction. 421 * 422 * This is a hardware-specific implementation of how 423 * transactions are executed that the drivers must provide. 424 * 425 * A pointer to a &drm_dp_aux_msg structure describing the 426 * transaction is passed into this function. Upon success, the 427 * implementation should return the number of payload bytes that 428 * were transferred, or a negative error-code on failure. 429 * 430 * Helpers will propagate these errors, with the exception of 431 * the %-EBUSY error, which causes a transaction to be retried. 432 * On a short, helpers will return %-EPROTO to make it simpler 433 * to check for failure. 434 * 435 * The @transfer() function must only modify the reply field of 436 * the &drm_dp_aux_msg structure. The retry logic and i2c 437 * helpers assume this is the case. 438 * 439 * Also note that this callback can be called no matter the 440 * state @dev is in and also no matter what state the panel is 441 * in. It's expected: 442 * 443 * - If the @dev providing the AUX bus is currently unpowered then 444 * it will power itself up for the transfer. 445 * 446 * - If we're on eDP (using a drm_panel) and the panel is not in a 447 * state where it can respond (it's not powered or it's in a 448 * low power state) then this function may return an error, but 449 * not crash. It's up to the caller of this code to make sure that 450 * the panel is powered on if getting an error back is not OK. If a 451 * drm_panel driver is initiating a DP AUX transfer it may power 452 * itself up however it wants. All other code should ensure that 453 * the pre_enable() bridge chain (which eventually calls the 454 * drm_panel prepare function) has powered the panel. 455 */ 456 ssize_t (*transfer)(struct drm_dp_aux *aux, 457 struct drm_dp_aux_msg *msg); 458 459 /** 460 * @wait_hpd_asserted: wait for HPD to be asserted 461 * 462 * This is mainly useful for eDP panels drivers to wait for an eDP 463 * panel to finish powering on. It is optional for DP AUX controllers 464 * to implement this function. It is required for DP AUX endpoints 465 * (panel drivers) to call this function after powering up but before 466 * doing AUX transfers unless the DP AUX endpoint driver knows that 467 * we're not using the AUX controller's HPD. One example of the panel 468 * driver not needing to call this is if HPD is hooked up to a GPIO 469 * that the panel driver can read directly. 470 * 471 * If a DP AUX controller does not implement this function then it 472 * may still support eDP panels that use the AUX controller's built-in 473 * HPD signal by implementing a long wait for HPD in the transfer() 474 * callback, though this is deprecated. 475 * 476 * This function will efficiently wait for the HPD signal to be 477 * asserted. The `wait_us` parameter that is passed in says that we 478 * know that the HPD signal is expected to be asserted within `wait_us` 479 * microseconds. This function could wait for longer than `wait_us` if 480 * the logic in the DP controller has a long debouncing time. The 481 * important thing is that if this function returns success that the 482 * DP controller is ready to send AUX transactions. 483 * 484 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time 485 * expired and HPD wasn't asserted. This function should not print 486 * timeout errors to the log. 487 * 488 * The semantics of this function are designed to match the 489 * readx_poll_timeout() function. That means a `wait_us` of 0 means 490 * to wait forever. Like readx_poll_timeout(), this function may sleep. 491 * 492 * NOTE: this function specifically reports the state of the HPD pin 493 * that's associated with the DP AUX channel. This is different from 494 * the HPD concept in much of the rest of DRM which is more about 495 * physical presence of a display. For eDP, for instance, a display is 496 * assumed always present even if the HPD pin is deasserted. 497 */ 498 int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us); 499 500 /** 501 * @i2c_nack_count: Counts I2C NACKs, used for DP validation. 502 */ 503 unsigned i2c_nack_count; 504 /** 505 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation. 506 */ 507 unsigned i2c_defer_count; 508 /** 509 * @cec: struct containing fields used for CEC-Tunneling-over-AUX. 510 */ 511 struct drm_dp_aux_cec cec; 512 /** 513 * @is_remote: Is this AUX CH actually using sideband messaging. 514 */ 515 bool is_remote; 516 517 /** 518 * @powered_down: If true then the remote endpoint is powered down. 519 */ 520 bool powered_down; 521 522 /** 523 * @no_zero_sized: If the hw can't use zero sized transfers (NVIDIA) 524 */ 525 bool no_zero_sized; 526 }; 527 528 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset); 529 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered); 530 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, 531 void *buffer, size_t size); 532 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, 533 void *buffer, size_t size); 534 535 /** 536 * drm_dp_dpcd_read_data() - read a series of bytes from the DPCD 537 * @aux: DisplayPort AUX channel (SST or MST) 538 * @offset: address of the (first) register to read 539 * @buffer: buffer to store the register values 540 * @size: number of bytes in @buffer 541 * 542 * Returns zero (0) on success, or a negative error 543 * code on failure. -EIO is returned if the request was NAKed by the sink or 544 * if the retry count was exceeded. If not all bytes were transferred, this 545 * function returns -EPROTO. Errors from the underlying AUX channel transfer 546 * function, with the exception of -EBUSY (which causes the transaction to 547 * be retried), are propagated to the caller. 548 */ 549 static inline int drm_dp_dpcd_read_data(struct drm_dp_aux *aux, 550 unsigned int offset, 551 void *buffer, size_t size) 552 { 553 int ret; 554 555 ret = drm_dp_dpcd_read(aux, offset, buffer, size); 556 if (ret < 0) 557 return ret; 558 if (ret < size) 559 return -EPROTO; 560 561 return 0; 562 } 563 564 /** 565 * drm_dp_dpcd_write_data() - write a series of bytes to the DPCD 566 * @aux: DisplayPort AUX channel (SST or MST) 567 * @offset: address of the (first) register to write 568 * @buffer: buffer containing the values to write 569 * @size: number of bytes in @buffer 570 * 571 * Returns zero (0) on success, or a negative error 572 * code on failure. -EIO is returned if the request was NAKed by the sink or 573 * if the retry count was exceeded. If not all bytes were transferred, this 574 * function returns -EPROTO. Errors from the underlying AUX channel transfer 575 * function, with the exception of -EBUSY (which causes the transaction to 576 * be retried), are propagated to the caller. 577 */ 578 static inline int drm_dp_dpcd_write_data(struct drm_dp_aux *aux, 579 unsigned int offset, 580 void *buffer, size_t size) 581 { 582 int ret; 583 584 ret = drm_dp_dpcd_write(aux, offset, buffer, size); 585 if (ret < 0) 586 return ret; 587 if (ret < size) 588 return -EPROTO; 589 590 return 0; 591 } 592 593 /** 594 * drm_dp_dpcd_readb() - read a single byte from the DPCD 595 * @aux: DisplayPort AUX channel 596 * @offset: address of the register to read 597 * @valuep: location where the value of the register will be stored 598 * 599 * Returns the number of bytes transferred (1) on success, or a negative 600 * error code on failure. In most of the cases you should be using 601 * drm_dp_dpcd_read_byte() instead. 602 */ 603 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux, 604 unsigned int offset, u8 *valuep) 605 { 606 return drm_dp_dpcd_read(aux, offset, valuep, 1); 607 } 608 609 /** 610 * drm_dp_dpcd_writeb() - write a single byte to the DPCD 611 * @aux: DisplayPort AUX channel 612 * @offset: address of the register to write 613 * @value: value to write to the register 614 * 615 * Returns the number of bytes transferred (1) on success, or a negative 616 * error code on failure. In most of the cases you should be using 617 * drm_dp_dpcd_write_byte() instead. 618 */ 619 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux, 620 unsigned int offset, u8 value) 621 { 622 return drm_dp_dpcd_write(aux, offset, &value, 1); 623 } 624 625 /** 626 * drm_dp_dpcd_read_byte() - read a single byte from the DPCD 627 * @aux: DisplayPort AUX channel 628 * @offset: address of the register to read 629 * @valuep: location where the value of the register will be stored 630 * 631 * Returns zero (0) on success, or a negative error code on failure. 632 */ 633 static inline int drm_dp_dpcd_read_byte(struct drm_dp_aux *aux, 634 unsigned int offset, u8 *valuep) 635 { 636 return drm_dp_dpcd_read_data(aux, offset, valuep, 1); 637 } 638 639 /** 640 * drm_dp_dpcd_write_byte() - write a single byte to the DPCD 641 * @aux: DisplayPort AUX channel 642 * @offset: address of the register to write 643 * @value: value to write to the register 644 * 645 * Returns zero (0) on success, or a negative error code on failure. 646 */ 647 static inline int drm_dp_dpcd_write_byte(struct drm_dp_aux *aux, 648 unsigned int offset, u8 value) 649 { 650 return drm_dp_dpcd_write_data(aux, offset, &value, 1); 651 } 652 653 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, 654 u8 dpcd[DP_RECEIVER_CAP_SIZE]); 655 656 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, 657 u8 status[DP_LINK_STATUS_SIZE]); 658 659 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, 660 enum drm_dp_phy dp_phy, 661 u8 link_status[DP_LINK_STATUS_SIZE]); 662 int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision); 663 int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision); 664 665 int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux, 666 int vcpid, u8 start_time_slot, u8 time_slot_count); 667 int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux); 668 int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms); 669 670 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, 671 u8 real_edid_checksum); 672 673 int drm_dp_read_downstream_info(struct drm_dp_aux *aux, 674 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 675 u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]); 676 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 677 const u8 port_cap[4], u8 type); 678 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 679 const u8 port_cap[4], 680 const struct drm_edid *drm_edid); 681 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 682 const u8 port_cap[4]); 683 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 684 const u8 port_cap[4], 685 const struct drm_edid *drm_edid); 686 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 687 const u8 port_cap[4], 688 const struct drm_edid *drm_edid); 689 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 690 const u8 port_cap[4], 691 const struct drm_edid *drm_edid); 692 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 693 const u8 port_cap[4]); 694 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 695 const u8 port_cap[4]); 696 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev, 697 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 698 const u8 port_cap[4]); 699 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]); 700 void drm_dp_downstream_debug(struct seq_file *m, 701 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 702 const u8 port_cap[4], 703 const struct drm_edid *drm_edid, 704 struct drm_dp_aux *aux); 705 enum drm_mode_subconnector 706 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 707 const u8 port_cap[4]); 708 void drm_dp_set_subconnector_property(struct drm_connector *connector, 709 enum drm_connector_status status, 710 const u8 *dpcd, 711 const u8 port_cap[4]); 712 713 struct drm_dp_desc; 714 bool drm_dp_read_sink_count_cap(struct drm_connector *connector, 715 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 716 const struct drm_dp_desc *desc); 717 int drm_dp_read_sink_count(struct drm_dp_aux *aux); 718 719 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, 720 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 721 u8 caps[DP_LTTPR_COMMON_CAP_SIZE]); 722 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux, 723 const u8 dpcd[DP_RECEIVER_CAP_SIZE], 724 enum drm_dp_phy dp_phy, 725 u8 caps[DP_LTTPR_PHY_CAP_SIZE]); 726 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]); 727 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]); 728 int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable); 729 int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count); 730 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]); 731 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]); 732 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]); 733 void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode); 734 735 void drm_dp_remote_aux_init(struct drm_dp_aux *aux); 736 void drm_dp_aux_init(struct drm_dp_aux *aux); 737 int drm_dp_aux_register(struct drm_dp_aux *aux); 738 void drm_dp_aux_unregister(struct drm_dp_aux *aux); 739 740 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc); 741 int drm_dp_stop_crc(struct drm_dp_aux *aux); 742 743 struct drm_dp_dpcd_ident { 744 u8 oui[3]; 745 u8 device_id[6]; 746 u8 hw_rev; 747 u8 sw_major_rev; 748 u8 sw_minor_rev; 749 } __packed; 750 751 /** 752 * struct drm_dp_desc - DP branch/sink device descriptor 753 * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). 754 * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. 755 */ 756 struct drm_dp_desc { 757 struct drm_dp_dpcd_ident ident; 758 u32 quirks; 759 }; 760 761 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, 762 bool is_branch); 763 764 int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy); 765 766 /** 767 * enum drm_dp_quirk - Display Port sink/branch device specific quirks 768 * 769 * Display Port sink and branch devices in the wild have a variety of bugs, try 770 * to collect them here. The quirks are shared, but it's up to the drivers to 771 * implement workarounds for them. 772 */ 773 enum drm_dp_quirk { 774 /** 775 * @DP_DPCD_QUIRK_CONSTANT_N: 776 * 777 * The device requires main link attributes Mvid and Nvid to be limited 778 * to 16 bits. So will give a constant value (0x8000) for compatability. 779 */ 780 DP_DPCD_QUIRK_CONSTANT_N, 781 /** 782 * @DP_DPCD_QUIRK_NO_PSR: 783 * 784 * The device does not support PSR even if reports that it supports or 785 * driver still need to implement proper handling for such device. 786 */ 787 DP_DPCD_QUIRK_NO_PSR, 788 /** 789 * @DP_DPCD_QUIRK_NO_SINK_COUNT: 790 * 791 * The device does not set SINK_COUNT to a non-zero value. 792 * The driver should ignore SINK_COUNT during detection. Note that 793 * drm_dp_read_sink_count_cap() automatically checks for this quirk. 794 */ 795 DP_DPCD_QUIRK_NO_SINK_COUNT, 796 /** 797 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD: 798 * 799 * The device supports MST DSC despite not supporting Virtual DPCD. 800 * The DSC caps can be read from the physical aux instead. 801 */ 802 DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD, 803 /** 804 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS: 805 * 806 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite 807 * the DP_MAX_LINK_RATE register reporting a lower max multiplier. 808 */ 809 DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS, 810 /** 811 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC: 812 * 813 * The device applies HBLANK expansion for some modes, but this 814 * requires enabling DSC. 815 */ 816 DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC, 817 }; 818 819 /** 820 * drm_dp_has_quirk() - does the DP device have a specific quirk 821 * @desc: Device descriptor filled by drm_dp_read_desc() 822 * @quirk: Quirk to query for 823 * 824 * Return true if DP device identified by @desc has @quirk. 825 */ 826 static inline bool 827 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) 828 { 829 return desc->quirks & BIT(quirk); 830 } 831 832 /** 833 * struct drm_edp_backlight_info - Probed eDP backlight info struct 834 * @pwmgen_bit_count: The pwmgen bit count 835 * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any 836 * @max: The maximum backlight level that may be set 837 * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register? 838 * @aux_enable: Does the panel support the AUX enable cap? 839 * @aux_set: Does the panel support setting the brightness through AUX? 840 * 841 * This structure contains various data about an eDP backlight, which can be populated by using 842 * drm_edp_backlight_init(). 843 */ 844 struct drm_edp_backlight_info { 845 u8 pwmgen_bit_count; 846 u8 pwm_freq_pre_divider; 847 u16 max; 848 849 bool lsb_reg_used : 1; 850 bool aux_enable : 1; 851 bool aux_set : 1; 852 }; 853 854 int 855 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, 856 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE], 857 u16 *current_level, u8 *current_mode); 858 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 859 u16 level); 860 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, 861 u16 level); 862 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl); 863 864 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \ 865 (IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE))) 866 867 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux); 868 869 #else 870 871 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel, 872 struct drm_dp_aux *aux) 873 { 874 return 0; 875 } 876 877 #endif 878 879 #ifdef CONFIG_DRM_DISPLAY_DP_AUX_CEC 880 void drm_dp_cec_irq(struct drm_dp_aux *aux); 881 void drm_dp_cec_register_connector(struct drm_dp_aux *aux, 882 struct drm_connector *connector); 883 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux); 884 void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address); 885 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid); 886 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux); 887 #else 888 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux) 889 { 890 } 891 892 static inline void 893 drm_dp_cec_register_connector(struct drm_dp_aux *aux, 894 struct drm_connector *connector) 895 { 896 } 897 898 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux) 899 { 900 } 901 902 static inline void drm_dp_cec_attach(struct drm_dp_aux *aux, 903 u16 source_physical_address) 904 { 905 } 906 907 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux, 908 const struct edid *edid) 909 { 910 } 911 912 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux) 913 { 914 } 915 916 #endif 917 918 /** 919 * struct drm_dp_phy_test_params - DP Phy Compliance parameters 920 * @link_rate: Requested Link rate from DPCD 0x219 921 * @num_lanes: Number of lanes requested by sing through DPCD 0x220 922 * @phy_pattern: DP Phy test pattern from DPCD 0x248 923 * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B 924 * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259 925 * @enhanced_frame_cap: flag for enhanced frame capability. 926 */ 927 struct drm_dp_phy_test_params { 928 int link_rate; 929 u8 num_lanes; 930 u8 phy_pattern; 931 u8 hbr2_reset[2]; 932 u8 custom80[10]; 933 bool enhanced_frame_cap; 934 }; 935 936 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, 937 struct drm_dp_phy_test_params *data); 938 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, 939 struct drm_dp_phy_test_params *data, u8 dp_rev); 940 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 941 const u8 port_cap[4]); 942 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd); 943 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux); 944 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps, 945 u8 frl_mode); 946 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask, 947 u8 frl_type); 948 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux); 949 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux); 950 951 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux); 952 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask); 953 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux, 954 struct drm_connector *connector); 955 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]); 956 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]); 957 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]); 958 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]); 959 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux); 960 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]); 961 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]); 962 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], 963 const u8 port_cap[4], u8 color_spc); 964 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc); 965 966 #define DRM_DP_BW_OVERHEAD_MST BIT(0) 967 #define DRM_DP_BW_OVERHEAD_UHBR BIT(1) 968 #define DRM_DP_BW_OVERHEAD_SSC_REF_CLK BIT(2) 969 #define DRM_DP_BW_OVERHEAD_FEC BIT(3) 970 #define DRM_DP_BW_OVERHEAD_DSC BIT(4) 971 972 int drm_dp_bw_overhead(int lane_count, int hactive, 973 int dsc_slice_count, 974 int bpp_x16, unsigned long flags); 975 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr); 976 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes); 977 978 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp); 979 int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count, 980 int bpp_x16, int symbol_size, bool is_mst); 981 982 #endif /* _DRM_DP_HELPER_H_ */ 983