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);
40bool drm_dp_post_lt_adj_req_in_progress(const u8 link_status[DP_LINK_STATUS_SIZE]);
41u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
42 int lane);
43u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
44 int lane);
45u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
46 int lane);
47
48int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
49 enum drm_dp_phy dp_phy, bool uhbr);
50int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
51 enum drm_dp_phy dp_phy, bool uhbr);
52
53void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
54 const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
55void drm_dp_lttpr_link_train_clock_recovery_delay(void);
56void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
57 const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
58void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
59 const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
60
61int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
62bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
63 int lane_count);
64bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
65 int lane_count);
66bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
67bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
68bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
69
70u8 drm_dp_link_rate_to_bw_code(int link_rate);
71int drm_dp_bw_code_to_link_rate(u8 link_bw);
72
73const char *drm_dp_phy_name(enum drm_dp_phy dp_phy);
74
75/**
76 * struct drm_dp_vsc_sdp - drm DP VSC SDP
77 *
78 * This structure represents a DP VSC SDP of drm
79 * It is based on DP 1.4 spec [Table 2-116: VSC SDP Header Bytes] and
80 * [Table 2-117: VSC SDP Payload for DB16 through DB18]
81 *
82 * @sdp_type: secondary-data packet type
83 * @revision: revision number
84 * @length: number of valid data bytes
85 * @pixelformat: pixel encoding format
86 * @colorimetry: colorimetry format
87 * @bpc: bit per color
88 * @dynamic_range: dynamic range information
89 * @content_type: CTA-861-G defines content types and expected processing by a sink device
90 */
91struct drm_dp_vsc_sdp {
92 unsigned char sdp_type;
93 unsigned char revision;
94 unsigned char length;
95 enum dp_pixelformat pixelformat;
96 enum dp_colorimetry colorimetry;
97 int bpc;
98 enum dp_dynamic_range dynamic_range;
99 enum dp_content_type content_type;
100};
101
102/**
103 * struct drm_dp_as_sdp - drm DP Adaptive Sync SDP
104 *
105 * This structure represents a DP AS SDP of drm
106 * It is based on DP 2.1 spec [Table 2-126: Adaptive-Sync SDP Header Bytes] and
107 * [Table 2-127: Adaptive-Sync SDP Payload for DB0 through DB8]
108 *
109 * @sdp_type: Secondary-data packet type
110 * @revision: Revision Number
111 * @length: Number of valid data bytes
112 * @vtotal: Minimum Vertical Vtotal
113 * @target_rr: Target Refresh
114 * @duration_incr_ms: Successive frame duration increase
115 * @duration_decr_ms: Successive frame duration decrease
116 * @target_rr_divider: Target refresh rate divider
117 * @mode: Adaptive Sync Operation Mode
118 */
119struct drm_dp_as_sdp {
120 unsigned char sdp_type;
121 unsigned char revision;
122 unsigned char length;
123 int vtotal;
124 int target_rr;
125 int duration_incr_ms;
126 int duration_decr_ms;
127 bool target_rr_divider;
128 enum operation_mode mode;
129};
130
131void drm_dp_as_sdp_log(struct drm_printer *p,
132 const struct drm_dp_as_sdp *as_sdp);
133void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
134
135bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
136bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
137
138int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
139
140static inline int
141drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
142{
143 return drm_dp_bw_code_to_link_rate(link_bw: dpcd[DP_MAX_LINK_RATE]);
144}
145
146static inline u8
147drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
148{
149 return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
150}
151
152static inline bool
153drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
154{
155 return dpcd[DP_DPCD_REV] >= 0x11 &&
156 (dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
157}
158
159static inline bool
160drm_dp_post_lt_adj_req_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
161{
162 return dpcd[DP_DPCD_REV] >= 0x13 &&
163 (dpcd[DP_MAX_LANE_COUNT] & DP_POST_LT_ADJ_REQ_SUPPORTED);
164}
165
166static inline bool
167drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
168{
169 return dpcd[DP_DPCD_REV] >= 0x11 &&
170 (dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
171}
172
173static inline bool
174drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
175{
176 return dpcd[DP_DPCD_REV] >= 0x12 &&
177 dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
178}
179
180static inline bool
181drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
182{
183 return dpcd[DP_DPCD_REV] >= 0x11 ||
184 dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
185}
186
187static inline bool
188drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
189{
190 return dpcd[DP_DPCD_REV] >= 0x14 &&
191 dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
192}
193
194static inline u8
195drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
196{
197 return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
198 DP_TRAINING_PATTERN_MASK;
199}
200
201static inline bool
202drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
203{
204 return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
205}
206
207/* DP/eDP DSC support */
208u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
209u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
210 bool is_edp);
211u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
212int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
213 u8 dsc_bpc[3]);
214int drm_dp_dsc_sink_max_slice_throughput(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
215 int peak_pixel_rate, bool is_rgb_yuv444);
216int drm_dp_dsc_branch_max_overall_throughput(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE],
217 bool is_rgb_yuv444);
218int drm_dp_dsc_branch_max_line_width(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE]);
219
220static inline bool
221drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
222{
223 return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
224 DP_DSC_DECOMPRESSION_IS_SUPPORTED;
225}
226
227static inline u16
228drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
229{
230 return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
231 ((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
232 DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
233}
234
235static inline u32
236drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
237{
238 /* Max Slicewidth = Number of Pixels * 320 */
239 return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
240 DP_DSC_SLICE_WIDTH_MULTIPLIER;
241}
242
243/**
244 * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format
245 * @dsc_dpcd : DSC-capability DPCDs of the sink
246 * @output_format: output_format which is to be checked
247 *
248 * Returns true if the sink supports DSC with the given output_format, false otherwise.
249 */
250static inline bool
251drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format)
252{
253 return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format;
254}
255
256/* Forward Error Correction Support on DP 1.4 */
257static inline bool
258drm_dp_sink_supports_fec(const u8 fec_capable)
259{
260 return fec_capable & DP_FEC_CAPABLE;
261}
262
263static inline bool
264drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
265{
266 return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
267}
268
269static inline bool
270drm_dp_128b132b_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
271{
272 return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_128B132B;
273}
274
275static inline bool
276drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
277{
278 return dpcd[DP_EDP_CONFIGURATION_CAP] &
279 DP_ALTERNATE_SCRAMBLER_RESET_CAP;
280}
281
282/* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
283static inline bool
284drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
285{
286 return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
287 DP_MSA_TIMING_PAR_IGNORED;
288}
289
290/**
291 * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
292 * @edp_dpcd: The DPCD to check
293 *
294 * Note that currently this function will return %false for panels which support various DPCD
295 * backlight features but which require the brightness be set through PWM, and don't support setting
296 * the brightness level via the DPCD.
297 *
298 * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
299 * otherwise
300 */
301static inline bool
302drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
303{
304 return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
305}
306
307/**
308 * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR
309 * @link_rate: link rate in 10kbits/s units
310 *
311 * Determine if the provided link rate is an UHBR rate.
312 *
313 * Returns: %True if @link_rate is an UHBR rate.
314 */
315static inline bool drm_dp_is_uhbr_rate(int link_rate)
316{
317 return link_rate >= 1000000;
318}
319
320/*
321 * DisplayPort AUX channel
322 */
323
324/**
325 * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
326 * @address: address of the (first) register to access
327 * @request: contains the type of transaction (see DP_AUX_* macros)
328 * @reply: upon completion, contains the reply type of the transaction
329 * @buffer: pointer to a transmission or reception buffer
330 * @size: size of @buffer
331 */
332struct drm_dp_aux_msg {
333 unsigned int address;
334 u8 request;
335 u8 reply;
336 void *buffer;
337 size_t size;
338};
339
340struct cec_adapter;
341struct drm_connector;
342struct drm_edid;
343
344/**
345 * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
346 * @lock: mutex protecting this struct
347 * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
348 * @connector: the connector this CEC adapter is associated with
349 * @unregister_work: unregister the CEC adapter
350 */
351struct drm_dp_aux_cec {
352 struct mutex lock;
353 struct cec_adapter *adap;
354 struct drm_connector *connector;
355 struct delayed_work unregister_work;
356};
357
358/**
359 * struct drm_dp_aux - DisplayPort AUX channel
360 *
361 * An AUX channel can also be used to transport I2C messages to a sink. A
362 * typical application of that is to access an EDID that's present in the sink
363 * device. The @transfer() function can also be used to execute such
364 * transactions. The drm_dp_aux_register() function registers an I2C adapter
365 * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
366 * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
367 * transfers by default; if a partial response is received, the adapter will
368 * drop down to the size given by the partial response for this transaction
369 * only.
370 */
371struct drm_dp_aux {
372 /**
373 * @name: user-visible name of this AUX channel and the
374 * I2C-over-AUX adapter.
375 *
376 * It's also used to specify the name of the I2C adapter. If set
377 * to %NULL, dev_name() of @dev will be used.
378 */
379 const char *name;
380
381 /**
382 * @ddc: I2C adapter that can be used for I2C-over-AUX
383 * communication
384 */
385 struct i2c_adapter ddc;
386
387 /**
388 * @dev: pointer to struct device that is the parent for this
389 * AUX channel.
390 */
391 struct device *dev;
392
393 /**
394 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
395 * Beware, this may be %NULL before drm_dp_aux_register() has been
396 * called.
397 *
398 * It should be set to the &drm_device that will be using this AUX
399 * channel as early as possible. For many graphics drivers this should
400 * happen before drm_dp_aux_init(), however it's perfectly fine to set
401 * this field later so long as it's assigned before calling
402 * drm_dp_aux_register().
403 */
404 struct drm_device *drm_dev;
405
406 /**
407 * @crtc: backpointer to the crtc that is currently using this
408 * AUX channel
409 */
410 struct drm_crtc *crtc;
411
412 /**
413 * @hw_mutex: internal mutex used for locking transfers.
414 *
415 * Note that if the underlying hardware is shared among multiple
416 * channels, the driver needs to do additional locking to
417 * prevent concurrent access.
418 */
419 struct mutex hw_mutex;
420
421 /**
422 * @crc_work: worker that captures CRCs for each frame
423 */
424 struct work_struct crc_work;
425
426 /**
427 * @crc_count: counter of captured frame CRCs
428 */
429 u8 crc_count;
430
431 /**
432 * @transfer: transfers a message representing a single AUX
433 * transaction.
434 *
435 * This is a hardware-specific implementation of how
436 * transactions are executed that the drivers must provide.
437 *
438 * A pointer to a &drm_dp_aux_msg structure describing the
439 * transaction is passed into this function. Upon success, the
440 * implementation should return the number of payload bytes that
441 * were transferred, or a negative error-code on failure.
442 *
443 * Helpers will propagate these errors, with the exception of
444 * the %-EBUSY error, which causes a transaction to be retried.
445 * On a short, helpers will return %-EPROTO to make it simpler
446 * to check for failure.
447 *
448 * The @transfer() function must only modify the reply field of
449 * the &drm_dp_aux_msg structure. The retry logic and i2c
450 * helpers assume this is the case.
451 *
452 * Also note that this callback can be called no matter the
453 * state @dev is in and also no matter what state the panel is
454 * in. It's expected:
455 *
456 * - If the @dev providing the AUX bus is currently unpowered then
457 * it will power itself up for the transfer.
458 *
459 * - If we're on eDP (using a drm_panel) and the panel is not in a
460 * state where it can respond (it's not powered or it's in a
461 * low power state) then this function may return an error, but
462 * not crash. It's up to the caller of this code to make sure that
463 * the panel is powered on if getting an error back is not OK. If a
464 * drm_panel driver is initiating a DP AUX transfer it may power
465 * itself up however it wants. All other code should ensure that
466 * the pre_enable() bridge chain (which eventually calls the
467 * drm_panel prepare function) has powered the panel.
468 */
469 ssize_t (*transfer)(struct drm_dp_aux *aux,
470 struct drm_dp_aux_msg *msg);
471
472 /**
473 * @wait_hpd_asserted: wait for HPD to be asserted
474 *
475 * This is mainly useful for eDP panels drivers to wait for an eDP
476 * panel to finish powering on. It is optional for DP AUX controllers
477 * to implement this function. It is required for DP AUX endpoints
478 * (panel drivers) to call this function after powering up but before
479 * doing AUX transfers unless the DP AUX endpoint driver knows that
480 * we're not using the AUX controller's HPD. One example of the panel
481 * driver not needing to call this is if HPD is hooked up to a GPIO
482 * that the panel driver can read directly.
483 *
484 * If a DP AUX controller does not implement this function then it
485 * may still support eDP panels that use the AUX controller's built-in
486 * HPD signal by implementing a long wait for HPD in the transfer()
487 * callback, though this is deprecated.
488 *
489 * This function will efficiently wait for the HPD signal to be
490 * asserted. The `wait_us` parameter that is passed in says that we
491 * know that the HPD signal is expected to be asserted within `wait_us`
492 * microseconds. This function could wait for longer than `wait_us` if
493 * the logic in the DP controller has a long debouncing time. The
494 * important thing is that if this function returns success that the
495 * DP controller is ready to send AUX transactions.
496 *
497 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
498 * expired and HPD wasn't asserted. This function should not print
499 * timeout errors to the log.
500 *
501 * The semantics of this function are designed to match the
502 * readx_poll_timeout() function. That means a `wait_us` of 0 means
503 * to wait forever. Like readx_poll_timeout(), this function may sleep.
504 *
505 * NOTE: this function specifically reports the state of the HPD pin
506 * that's associated with the DP AUX channel. This is different from
507 * the HPD concept in much of the rest of DRM which is more about
508 * physical presence of a display. For eDP, for instance, a display is
509 * assumed always present even if the HPD pin is deasserted.
510 */
511 int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
512
513 /**
514 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
515 */
516 unsigned i2c_nack_count;
517 /**
518 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
519 */
520 unsigned i2c_defer_count;
521 /**
522 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
523 */
524 struct drm_dp_aux_cec cec;
525 /**
526 * @is_remote: Is this AUX CH actually using sideband messaging.
527 */
528 bool is_remote;
529
530 /**
531 * @powered_down: If true then the remote endpoint is powered down.
532 */
533 bool powered_down;
534
535 /**
536 * @no_zero_sized: If the hw can't use zero sized transfers (NVIDIA)
537 */
538 bool no_zero_sized;
539
540 /**
541 * @dpcd_probe_disabled: If probing before a DPCD access is disabled.
542 */
543 bool dpcd_probe_disabled;
544};
545
546int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
547void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
548void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable);
549ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
550 void *buffer, size_t size);
551ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
552 void *buffer, size_t size);
553
554/**
555 * drm_dp_dpcd_readb() - read a single byte from the DPCD
556 * @aux: DisplayPort AUX channel
557 * @offset: address of the register to read
558 * @valuep: location where the value of the register will be stored
559 *
560 * Returns the number of bytes transferred (1) on success, or a negative
561 * error code on failure. In most of the cases you should be using
562 * drm_dp_dpcd_read_byte() instead.
563 */
564static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
565 unsigned int offset, u8 *valuep)
566{
567 return drm_dp_dpcd_read(aux, offset, buffer: valuep, size: 1);
568}
569
570/**
571 * drm_dp_dpcd_read_data() - read a series of bytes from the DPCD
572 * @aux: DisplayPort AUX channel (SST or MST)
573 * @offset: address of the (first) register to read
574 * @buffer: buffer to store the register values
575 * @size: number of bytes in @buffer
576 *
577 * Returns zero (0) on success, or a negative error
578 * code on failure. -EIO is returned if the request was NAKed by the sink or
579 * if the retry count was exceeded. If not all bytes were transferred, this
580 * function returns -EPROTO. Errors from the underlying AUX channel transfer
581 * function, with the exception of -EBUSY (which causes the transaction to
582 * be retried), are propagated to the caller.
583 */
584static inline int drm_dp_dpcd_read_data(struct drm_dp_aux *aux,
585 unsigned int offset,
586 void *buffer, size_t size)
587{
588 int ret;
589 size_t i;
590 u8 *buf = buffer;
591
592 ret = drm_dp_dpcd_read(aux, offset, buffer, size);
593 if (ret >= 0) {
594 if (ret < size)
595 return -EPROTO;
596 return 0;
597 }
598
599 /*
600 * Workaround for USB-C hubs/adapters with buggy firmware that fail
601 * multi-byte AUX reads but work with single-byte reads.
602 * Known affected devices:
603 * - Lenovo USB-C to VGA adapter (VIA VL817, idVendor=17ef, idProduct=7217)
604 * - Dell DA310 USB-C hub (idVendor=413c, idProduct=c010)
605 * Attempt byte-by-byte reading as a fallback.
606 */
607 for (i = 0; i < size; i++) {
608 ret = drm_dp_dpcd_readb(aux, offset: offset + i, valuep: &buf[i]);
609 if (ret < 0)
610 return ret;
611 }
612
613 return 0;
614}
615
616/**
617 * drm_dp_dpcd_write_data() - write a series of bytes to the DPCD
618 * @aux: DisplayPort AUX channel (SST or MST)
619 * @offset: address of the (first) register to write
620 * @buffer: buffer containing the values to write
621 * @size: number of bytes in @buffer
622 *
623 * Returns zero (0) on success, or a negative error
624 * code on failure. -EIO is returned if the request was NAKed by the sink or
625 * if the retry count was exceeded. If not all bytes were transferred, this
626 * function returns -EPROTO. Errors from the underlying AUX channel transfer
627 * function, with the exception of -EBUSY (which causes the transaction to
628 * be retried), are propagated to the caller.
629 */
630static inline int drm_dp_dpcd_write_data(struct drm_dp_aux *aux,
631 unsigned int offset,
632 void *buffer, size_t size)
633{
634 int ret;
635
636 ret = drm_dp_dpcd_write(aux, offset, buffer, size);
637 if (ret < 0)
638 return ret;
639 if (ret < size)
640 return -EPROTO;
641
642 return 0;
643}
644
645/**
646 * drm_dp_dpcd_writeb() - write a single byte to the DPCD
647 * @aux: DisplayPort AUX channel
648 * @offset: address of the register to write
649 * @value: value to write to the register
650 *
651 * Returns the number of bytes transferred (1) on success, or a negative
652 * error code on failure. In most of the cases you should be using
653 * drm_dp_dpcd_write_byte() instead.
654 */
655static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
656 unsigned int offset, u8 value)
657{
658 return drm_dp_dpcd_write(aux, offset, buffer: &value, size: 1);
659}
660
661/**
662 * drm_dp_dpcd_read_byte() - read a single byte from the DPCD
663 * @aux: DisplayPort AUX channel
664 * @offset: address of the register to read
665 * @valuep: location where the value of the register will be stored
666 *
667 * Returns zero (0) on success, or a negative error code on failure.
668 */
669static inline int drm_dp_dpcd_read_byte(struct drm_dp_aux *aux,
670 unsigned int offset, u8 *valuep)
671{
672 return drm_dp_dpcd_read_data(aux, offset, buffer: valuep, size: 1);
673}
674
675/**
676 * drm_dp_dpcd_write_byte() - write a single byte to the DPCD
677 * @aux: DisplayPort AUX channel
678 * @offset: address of the register to write
679 * @value: value to write to the register
680 *
681 * Returns zero (0) on success, or a negative error code on failure.
682 */
683static inline int drm_dp_dpcd_write_byte(struct drm_dp_aux *aux,
684 unsigned int offset, u8 value)
685{
686 return drm_dp_dpcd_write_data(aux, offset, buffer: &value, size: 1);
687}
688
689int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
690 u8 dpcd[DP_RECEIVER_CAP_SIZE]);
691
692int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
693 u8 status[DP_LINK_STATUS_SIZE]);
694
695int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
696 enum drm_dp_phy dp_phy,
697 u8 link_status[DP_LINK_STATUS_SIZE]);
698int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision);
699int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision);
700
701int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux,
702 int vcpid, u8 start_time_slot, u8 time_slot_count);
703int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux);
704int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms);
705
706bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
707 u8 real_edid_checksum);
708
709int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
710 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
711 u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
712bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
713 const u8 port_cap[4], u8 type);
714bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
715 const u8 port_cap[4],
716 const struct drm_edid *drm_edid);
717int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
718 const u8 port_cap[4]);
719int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
720 const u8 port_cap[4],
721 const struct drm_edid *drm_edid);
722int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
723 const u8 port_cap[4],
724 const struct drm_edid *drm_edid);
725int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
726 const u8 port_cap[4],
727 const struct drm_edid *drm_edid);
728bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
729 const u8 port_cap[4]);
730bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
731 const u8 port_cap[4]);
732struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
733 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
734 const u8 port_cap[4]);
735int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
736void drm_dp_downstream_debug(struct seq_file *m,
737 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
738 const u8 port_cap[4],
739 const struct drm_edid *drm_edid,
740 struct drm_dp_aux *aux);
741enum drm_mode_subconnector
742drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
743 const u8 port_cap[4]);
744void drm_dp_set_subconnector_property(struct drm_connector *connector,
745 enum drm_connector_status status,
746 const u8 *dpcd,
747 const u8 port_cap[4]);
748
749struct drm_dp_desc;
750bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
751 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
752 const struct drm_dp_desc *desc);
753int drm_dp_read_sink_count(struct drm_dp_aux *aux);
754
755int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
756 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
757 u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
758int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
759 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
760 enum drm_dp_phy dp_phy,
761 u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
762int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
763int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
764int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable);
765int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count);
766int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
767bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
768bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
769void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode);
770
771void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
772void drm_dp_aux_init(struct drm_dp_aux *aux);
773int drm_dp_aux_register(struct drm_dp_aux *aux);
774void drm_dp_aux_unregister(struct drm_dp_aux *aux);
775
776int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
777int drm_dp_stop_crc(struct drm_dp_aux *aux);
778
779struct drm_dp_dpcd_ident {
780 u8 oui[3];
781 u8 device_id[6];
782 u8 hw_rev;
783 u8 sw_major_rev;
784 u8 sw_minor_rev;
785} __packed;
786
787/**
788 * struct drm_dp_desc - DP branch/sink device descriptor
789 * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
790 * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
791 */
792struct drm_dp_desc {
793 struct drm_dp_dpcd_ident ident;
794 u32 quirks;
795};
796
797int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
798 bool is_branch);
799
800int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy);
801
802/**
803 * enum drm_dp_quirk - Display Port sink/branch device specific quirks
804 *
805 * Display Port sink and branch devices in the wild have a variety of bugs, try
806 * to collect them here. The quirks are shared, but it's up to the drivers to
807 * implement workarounds for them.
808 */
809enum drm_dp_quirk {
810 /**
811 * @DP_DPCD_QUIRK_CONSTANT_N:
812 *
813 * The device requires main link attributes Mvid and Nvid to be limited
814 * to 16 bits. So will give a constant value (0x8000) for compatability.
815 */
816 DP_DPCD_QUIRK_CONSTANT_N,
817 /**
818 * @DP_DPCD_QUIRK_NO_PSR:
819 *
820 * The device does not support PSR even if reports that it supports or
821 * driver still need to implement proper handling for such device.
822 */
823 DP_DPCD_QUIRK_NO_PSR,
824 /**
825 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
826 *
827 * The device does not set SINK_COUNT to a non-zero value.
828 * The driver should ignore SINK_COUNT during detection. Note that
829 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
830 */
831 DP_DPCD_QUIRK_NO_SINK_COUNT,
832 /**
833 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
834 *
835 * The device supports MST DSC despite not supporting Virtual DPCD.
836 * The DSC caps can be read from the physical aux instead.
837 */
838 DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
839 /**
840 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
841 *
842 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
843 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
844 */
845 DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
846 /**
847 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC:
848 *
849 * The device applies HBLANK expansion for some modes, but this
850 * requires enabling DSC.
851 */
852 DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC,
853 /**
854 * @DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT:
855 *
856 * The device doesn't support DSC decompression at the maximum DSC
857 * pixel throughput and compressed bpp it indicates via its DPCD DSC
858 * capabilities. The compressed bpp must be limited above a device
859 * specific DSC pixel throughput.
860 */
861 DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT,
862};
863
864/**
865 * drm_dp_has_quirk() - does the DP device have a specific quirk
866 * @desc: Device descriptor filled by drm_dp_read_desc()
867 * @quirk: Quirk to query for
868 *
869 * Return true if DP device identified by @desc has @quirk.
870 */
871static inline bool
872drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
873{
874 return desc->quirks & BIT(quirk);
875}
876
877/**
878 * struct drm_edp_backlight_info - Probed eDP backlight info struct
879 * @pwmgen_bit_count: The pwmgen bit count
880 * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
881 * @max: The maximum backlight level that may be set
882 * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
883 * @aux_enable: Does the panel support the AUX enable cap?
884 * @aux_set: Does the panel support setting the brightness through AUX?
885 * @luminance_set: Does the panel support setting the brightness through AUX using luminance values?
886 *
887 * This structure contains various data about an eDP backlight, which can be populated by using
888 * drm_edp_backlight_init().
889 */
890struct drm_edp_backlight_info {
891 u8 pwmgen_bit_count;
892 u8 pwm_freq_pre_divider;
893 u32 max;
894
895 bool lsb_reg_used : 1;
896 bool aux_enable : 1;
897 bool aux_set : 1;
898 bool luminance_set : 1;
899};
900
901int
902drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
903 u32 max_luminance,
904 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
905 u32 *current_level, u8 *current_mode, bool need_luminance);
906int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
907 u32 level);
908int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
909 u32 level);
910int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
911
912#if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
913 (IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
914
915int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
916
917#else
918
919static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
920 struct drm_dp_aux *aux)
921{
922 return 0;
923}
924
925#endif
926
927#ifdef CONFIG_DRM_DISPLAY_DP_AUX_CEC
928void drm_dp_cec_irq(struct drm_dp_aux *aux);
929void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
930 struct drm_connector *connector);
931void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
932void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
933void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
934void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
935#else
936static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
937{
938}
939
940static inline void
941drm_dp_cec_register_connector(struct drm_dp_aux *aux,
942 struct drm_connector *connector)
943{
944}
945
946static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
947{
948}
949
950static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
951 u16 source_physical_address)
952{
953}
954
955static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
956 const struct edid *edid)
957{
958}
959
960static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
961{
962}
963
964#endif
965
966/**
967 * struct drm_dp_phy_test_params - DP Phy Compliance parameters
968 * @link_rate: Requested Link rate from DPCD 0x219
969 * @num_lanes: Number of lanes requested by sing through DPCD 0x220
970 * @phy_pattern: DP Phy test pattern from DPCD 0x248
971 * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
972 * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
973 * @enhanced_frame_cap: flag for enhanced frame capability.
974 */
975struct drm_dp_phy_test_params {
976 int link_rate;
977 u8 num_lanes;
978 u8 phy_pattern;
979 u8 hbr2_reset[2];
980 u8 custom80[10];
981 bool enhanced_frame_cap;
982};
983
984int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
985 struct drm_dp_phy_test_params *data);
986int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
987 struct drm_dp_phy_test_params *data, u8 dp_rev);
988int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
989 const u8 port_cap[4]);
990int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
991bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
992int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
993 u8 frl_mode);
994int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
995 u8 frl_type);
996int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
997int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
998
999bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
1000int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
1001void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
1002 struct drm_connector *connector);
1003bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1004int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1005int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1006int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1007int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
1008int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
1009int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
1010bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1011 const u8 port_cap[4], u8 color_spc);
1012int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
1013
1014#define DRM_DP_BW_OVERHEAD_MST BIT(0)
1015#define DRM_DP_BW_OVERHEAD_UHBR BIT(1)
1016#define DRM_DP_BW_OVERHEAD_SSC_REF_CLK BIT(2)
1017#define DRM_DP_BW_OVERHEAD_FEC BIT(3)
1018#define DRM_DP_BW_OVERHEAD_DSC BIT(4)
1019
1020int drm_dp_bw_overhead(int lane_count, int hactive,
1021 int dsc_slice_count,
1022 int bpp_x16, unsigned long flags);
1023int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
1024int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
1025
1026ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
1027int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count,
1028 int bpp_x16, int symbol_size, bool is_mst);
1029
1030#endif /* _DRM_DP_HELPER_H_ */
1031

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