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
32struct drm_device;
33struct drm_dp_aux;
34struct drm_panel;
35
36bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
37 int lane_count);
38bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
39 int lane_count);
40u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
41 int lane);
42u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
43 int lane);
44u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
45 int lane);
46
47int 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);
49int 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
52void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
53 const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
54void drm_dp_lttpr_link_train_clock_recovery_delay(void);
55void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
56 const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
57void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
58 const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
59
60int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
61bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
62 int lane_count);
63bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
64 int lane_count);
65bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
66bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
67bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
68
69u8 drm_dp_link_rate_to_bw_code(int link_rate);
70int drm_dp_bw_code_to_link_rate(u8 link_bw);
71
72const 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 */
90struct 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 */
118struct 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
130void drm_dp_as_sdp_log(struct drm_printer *p,
131 const struct drm_dp_as_sdp *as_sdp);
132void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
133
134bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
135bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
136
137int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
138
139static inline int
140drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
141{
142 return drm_dp_bw_code_to_link_rate(link_bw: dpcd[DP_MAX_LINK_RATE]);
143}
144
145static inline u8
146drm_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
151static inline bool
152drm_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
158static inline bool
159drm_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
165static inline bool
166drm_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
172static inline bool
173drm_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
179static inline bool
180drm_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
186static inline u8
187drm_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
193static inline bool
194drm_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 */
200u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
201u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
202 bool is_edp);
203u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
204int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
205 u8 dsc_bpc[3]);
206
207static inline bool
208drm_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
214static inline u16
215drm_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
222static inline u32
223drm_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 */
237static inline bool
238drm_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 */
244static inline bool
245drm_dp_sink_supports_fec(const u8 fec_capable)
246{
247 return fec_capable & DP_FEC_CAPABLE;
248}
249
250static inline bool
251drm_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
256static inline bool
257drm_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
262static inline bool
263drm_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 */
270static inline bool
271drm_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 */
288static inline bool
289drm_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 */
302static 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 */
319struct drm_dp_aux_msg {
320 unsigned int address;
321 u8 request;
322 u8 reply;
323 void *buffer;
324 size_t size;
325};
326
327struct cec_adapter;
328struct drm_connector;
329struct 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 */
338struct 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 */
358struct 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
528int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
529void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
530ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
531 void *buffer, size_t size);
532ssize_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 */
549static 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 */
578static 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 */
603static 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, buffer: valuep, size: 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 */
619static 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, buffer: &value, size: 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 */
633static 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, buffer: valuep, size: 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 */
647static 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, buffer: &value, size: 1);
651}
652
653int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
654 u8 dpcd[DP_RECEIVER_CAP_SIZE]);
655
656int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
657 u8 status[DP_LINK_STATUS_SIZE]);
658
659int 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]);
662int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision);
663int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision);
664
665int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux,
666 int vcpid, u8 start_time_slot, u8 time_slot_count);
667int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux);
668int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms);
669
670bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
671 u8 real_edid_checksum);
672
673int 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]);
676bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
677 const u8 port_cap[4], u8 type);
678bool 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);
681int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
682 const u8 port_cap[4]);
683int 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);
686int 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);
689int 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);
692bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
693 const u8 port_cap[4]);
694bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
695 const u8 port_cap[4]);
696struct 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]);
699int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
700void 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);
705enum drm_mode_subconnector
706drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
707 const u8 port_cap[4]);
708void 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
713struct drm_dp_desc;
714bool 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);
717int drm_dp_read_sink_count(struct drm_dp_aux *aux);
718
719int 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]);
722int 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]);
726int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
727int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
728int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable);
729int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count);
730int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
731bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
732bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
733void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode);
734
735void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
736void drm_dp_aux_init(struct drm_dp_aux *aux);
737int drm_dp_aux_register(struct drm_dp_aux *aux);
738void drm_dp_aux_unregister(struct drm_dp_aux *aux);
739
740int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
741int drm_dp_stop_crc(struct drm_dp_aux *aux);
742
743struct 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 */
756struct drm_dp_desc {
757 struct drm_dp_dpcd_ident ident;
758 u32 quirks;
759};
760
761int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
762 bool is_branch);
763
764int 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 */
773enum 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 */
826static inline bool
827drm_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 */
844struct 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
854int
855drm_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);
858int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
859 u16 level);
860int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
861 u16 level);
862int 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
867int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
868
869#else
870
871static 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
880void drm_dp_cec_irq(struct drm_dp_aux *aux);
881void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
882 struct drm_connector *connector);
883void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
884void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
885void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
886void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
887#else
888static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
889{
890}
891
892static inline void
893drm_dp_cec_register_connector(struct drm_dp_aux *aux,
894 struct drm_connector *connector)
895{
896}
897
898static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
899{
900}
901
902static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
903 u16 source_physical_address)
904{
905}
906
907static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
908 const struct edid *edid)
909{
910}
911
912static 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 */
927struct 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
936int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
937 struct drm_dp_phy_test_params *data);
938int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
939 struct drm_dp_phy_test_params *data, u8 dp_rev);
940int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
941 const u8 port_cap[4]);
942int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
943bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
944int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
945 u8 frl_mode);
946int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
947 u8 frl_type);
948int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
949int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
950
951bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
952int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
953void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
954 struct drm_connector *connector);
955bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
956int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
957int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
958int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
959int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
960int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
961int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
962bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
963 const u8 port_cap[4], u8 color_spc);
964int 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
972int drm_dp_bw_overhead(int lane_count, int hactive,
973 int dsc_slice_count,
974 int bpp_x16, unsigned long flags);
975int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
976int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
977
978ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
979int 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

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source code of linux/include/drm/display/drm_dp_helper.h