xref: /linux/include/drm/display/drm_dp_helper.h (revision e878adca8477b4f6d51dee257c2ef3d2ad0086a5)
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 bool drm_dp_post_lt_adj_req_in_progress(const u8 link_status[DP_LINK_STATUS_SIZE]);
41 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
42 				     int lane);
43 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
44 					  int lane);
45 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
46 				   int lane);
47 
48 int 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);
50 int 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 
53 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
54 					    const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
55 void drm_dp_lttpr_link_train_clock_recovery_delay(void);
56 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
57 					const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
58 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
59 					      const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
60 
61 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
62 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
63 					  int lane_count);
64 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
65 					int lane_count);
66 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
67 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
68 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
69 
70 u8 drm_dp_link_rate_to_bw_code(int link_rate);
71 int drm_dp_bw_code_to_link_rate(u8 link_bw);
72 
73 const 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  */
91 struct 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  */
119 struct 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 	int coasting_vtotal;
130 };
131 
132 void drm_dp_as_sdp_log(struct drm_printer *p,
133 		       const struct drm_dp_as_sdp *as_sdp);
134 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
135 
136 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
137 bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
138 
139 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
140 
141 static inline int
142 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
143 {
144 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
145 }
146 
147 static inline u8
148 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
149 {
150 	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
151 }
152 
153 static inline bool
154 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
155 {
156 	return dpcd[DP_DPCD_REV] >= 0x11 &&
157 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
158 }
159 
160 static inline bool
161 drm_dp_post_lt_adj_req_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
162 {
163 	return dpcd[DP_DPCD_REV] >= 0x13 &&
164 		(dpcd[DP_MAX_LANE_COUNT] & DP_POST_LT_ADJ_REQ_SUPPORTED);
165 }
166 
167 static inline bool
168 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
169 {
170 	return dpcd[DP_DPCD_REV] >= 0x11 &&
171 		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
172 }
173 
174 static inline bool
175 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
176 {
177 	return dpcd[DP_DPCD_REV] >= 0x12 &&
178 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
179 }
180 
181 static inline bool
182 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
183 {
184 	return dpcd[DP_DPCD_REV] >= 0x11 ||
185 		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
186 }
187 
188 static inline bool
189 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
190 {
191 	return dpcd[DP_DPCD_REV] >= 0x14 &&
192 		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
193 }
194 
195 static inline u8
196 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
197 {
198 	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
199 		DP_TRAINING_PATTERN_MASK;
200 }
201 
202 static inline bool
203 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
204 {
205 	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
206 }
207 
208 /* DP/eDP DSC support */
209 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
210 u32 drm_dp_dsc_slice_count_to_mask(int slice_count);
211 u32 drm_dp_dsc_sink_slice_count_mask(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
212 				     bool is_edp);
213 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
214 				   bool is_edp);
215 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
216 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
217 					 u8 dsc_bpc[3]);
218 int drm_dp_dsc_sink_max_slice_throughput(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
219 					 int peak_pixel_rate, bool is_rgb_yuv444);
220 int drm_dp_dsc_branch_max_overall_throughput(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE],
221 					     bool is_rgb_yuv444);
222 int drm_dp_dsc_branch_max_line_width(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE]);
223 
224 static inline bool
225 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
226 {
227 	return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
228 		DP_DSC_DECOMPRESSION_IS_SUPPORTED;
229 }
230 
231 static inline u16
232 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
233 {
234 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
235 		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
236 		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
237 }
238 
239 static inline u32
240 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
241 {
242 	/* Max Slicewidth = Number of Pixels * 320 */
243 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
244 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
245 }
246 
247 /**
248  * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format
249  * @dsc_dpcd : DSC-capability DPCDs of the sink
250  * @output_format: output_format which is to be checked
251  *
252  * Returns true if the sink supports DSC with the given output_format, false otherwise.
253  */
254 static inline bool
255 drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format)
256 {
257 	return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format;
258 }
259 
260 /* Forward Error Correction Support on DP 1.4 */
261 static inline bool
262 drm_dp_sink_supports_fec(const u8 fec_capable)
263 {
264 	return fec_capable & DP_FEC_CAPABLE;
265 }
266 
267 static inline bool
268 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
269 {
270 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
271 }
272 
273 static inline bool
274 drm_dp_128b132b_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
275 {
276 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_128B132B;
277 }
278 
279 static inline bool
280 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
281 {
282 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
283 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
284 }
285 
286 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
287 static inline bool
288 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
289 {
290 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
291 		DP_MSA_TIMING_PAR_IGNORED;
292 }
293 
294 /**
295  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
296  * @edp_dpcd: The DPCD to check
297  *
298  * Note that currently this function will return %false for panels which support various DPCD
299  * backlight features but which require the brightness be set through PWM, and don't support setting
300  * the brightness level via the DPCD.
301  *
302  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
303  * otherwise
304  */
305 static inline bool
306 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
307 {
308 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
309 }
310 
311 /**
312  * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR
313  * @link_rate: link rate in 10kbits/s units
314  *
315  * Determine if the provided link rate is an UHBR rate.
316  *
317  * Returns: %True if @link_rate is an UHBR rate.
318  */
319 static inline bool drm_dp_is_uhbr_rate(int link_rate)
320 {
321 	return link_rate >= 1000000;
322 }
323 
324 /*
325  * DisplayPort AUX channel
326  */
327 
328 /**
329  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
330  * @address: address of the (first) register to access
331  * @request: contains the type of transaction (see DP_AUX_* macros)
332  * @reply: upon completion, contains the reply type of the transaction
333  * @buffer: pointer to a transmission or reception buffer
334  * @size: size of @buffer
335  */
336 struct drm_dp_aux_msg {
337 	unsigned int address;
338 	u8 request;
339 	u8 reply;
340 	void *buffer;
341 	size_t size;
342 };
343 
344 struct cec_adapter;
345 struct drm_connector;
346 struct drm_edid;
347 
348 /**
349  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
350  * @lock: mutex protecting this struct
351  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
352  * @connector: the connector this CEC adapter is associated with
353  * @unregister_work: unregister the CEC adapter
354  */
355 struct drm_dp_aux_cec {
356 	struct mutex lock;
357 	struct cec_adapter *adap;
358 	struct drm_connector *connector;
359 	struct delayed_work unregister_work;
360 };
361 
362 /**
363  * struct drm_dp_aux - DisplayPort AUX channel
364  *
365  * An AUX channel can also be used to transport I2C messages to a sink. A
366  * typical application of that is to access an EDID that's present in the sink
367  * device. The @transfer() function can also be used to execute such
368  * transactions. The drm_dp_aux_register() function registers an I2C adapter
369  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
370  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
371  * transfers by default; if a partial response is received, the adapter will
372  * drop down to the size given by the partial response for this transaction
373  * only.
374  */
375 struct drm_dp_aux {
376 	/**
377 	 * @name: user-visible name of this AUX channel and the
378 	 * I2C-over-AUX adapter.
379 	 *
380 	 * It's also used to specify the name of the I2C adapter. If set
381 	 * to %NULL, dev_name() of @dev will be used.
382 	 */
383 	const char *name;
384 
385 	/**
386 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
387 	 * communication
388 	 */
389 	struct i2c_adapter ddc;
390 
391 	/**
392 	 * @dev: pointer to struct device that is the parent for this
393 	 * AUX channel.
394 	 */
395 	struct device *dev;
396 
397 	/**
398 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
399 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
400 	 * called.
401 	 *
402 	 * It should be set to the &drm_device that will be using this AUX
403 	 * channel as early as possible. For many graphics drivers this should
404 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
405 	 * this field later so long as it's assigned before calling
406 	 * drm_dp_aux_register().
407 	 */
408 	struct drm_device *drm_dev;
409 
410 	/**
411 	 * @crtc: backpointer to the crtc that is currently using this
412 	 * AUX channel
413 	 */
414 	struct drm_crtc *crtc;
415 
416 	/**
417 	 * @hw_mutex: internal mutex used for locking transfers.
418 	 *
419 	 * Note that if the underlying hardware is shared among multiple
420 	 * channels, the driver needs to do additional locking to
421 	 * prevent concurrent access.
422 	 */
423 	struct mutex hw_mutex;
424 
425 	/**
426 	 * @crc_work: worker that captures CRCs for each frame
427 	 */
428 	struct work_struct crc_work;
429 
430 	/**
431 	 * @crc_count: counter of captured frame CRCs
432 	 */
433 	u8 crc_count;
434 
435 	/**
436 	 * @transfer: transfers a message representing a single AUX
437 	 * transaction.
438 	 *
439 	 * This is a hardware-specific implementation of how
440 	 * transactions are executed that the drivers must provide.
441 	 *
442 	 * A pointer to a &drm_dp_aux_msg structure describing the
443 	 * transaction is passed into this function. Upon success, the
444 	 * implementation should return the number of payload bytes that
445 	 * were transferred, or a negative error-code on failure.
446 	 *
447 	 * Helpers will propagate these errors, with the exception of
448 	 * the %-EBUSY error, which causes a transaction to be retried.
449 	 * On a short, helpers will return %-EPROTO to make it simpler
450 	 * to check for failure.
451 	 *
452 	 * The @transfer() function must only modify the reply field of
453 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
454 	 * helpers assume this is the case.
455 	 *
456 	 * Also note that this callback can be called no matter the
457 	 * state @dev is in and also no matter what state the panel is
458 	 * in. It's expected:
459 	 *
460 	 * - If the @dev providing the AUX bus is currently unpowered then
461 	 *   it will power itself up for the transfer.
462 	 *
463 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
464 	 *   state where it can respond (it's not powered or it's in a
465 	 *   low power state) then this function may return an error, but
466 	 *   not crash. It's up to the caller of this code to make sure that
467 	 *   the panel is powered on if getting an error back is not OK. If a
468 	 *   drm_panel driver is initiating a DP AUX transfer it may power
469 	 *   itself up however it wants. All other code should ensure that
470 	 *   the pre_enable() bridge chain (which eventually calls the
471 	 *   drm_panel prepare function) has powered the panel.
472 	 */
473 	ssize_t (*transfer)(struct drm_dp_aux *aux,
474 			    struct drm_dp_aux_msg *msg);
475 
476 	/**
477 	 * @wait_hpd_asserted: wait for HPD to be asserted
478 	 *
479 	 * This is mainly useful for eDP panels drivers to wait for an eDP
480 	 * panel to finish powering on. It is optional for DP AUX controllers
481 	 * to implement this function. It is required for DP AUX endpoints
482 	 * (panel drivers) to call this function after powering up but before
483 	 * doing AUX transfers unless the DP AUX endpoint driver knows that
484 	 * we're not using the AUX controller's HPD. One example of the panel
485 	 * driver not needing to call this is if HPD is hooked up to a GPIO
486 	 * that the panel driver can read directly.
487 	 *
488 	 * If a DP AUX controller does not implement this function then it
489 	 * may still support eDP panels that use the AUX controller's built-in
490 	 * HPD signal by implementing a long wait for HPD in the transfer()
491 	 * callback, though this is deprecated.
492 	 *
493 	 * This function will efficiently wait for the HPD signal to be
494 	 * asserted. The `wait_us` parameter that is passed in says that we
495 	 * know that the HPD signal is expected to be asserted within `wait_us`
496 	 * microseconds. This function could wait for longer than `wait_us` if
497 	 * the logic in the DP controller has a long debouncing time. The
498 	 * important thing is that if this function returns success that the
499 	 * DP controller is ready to send AUX transactions.
500 	 *
501 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
502 	 * expired and HPD wasn't asserted. This function should not print
503 	 * timeout errors to the log.
504 	 *
505 	 * The semantics of this function are designed to match the
506 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
507 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
508 	 *
509 	 * NOTE: this function specifically reports the state of the HPD pin
510 	 * that's associated with the DP AUX channel. This is different from
511 	 * the HPD concept in much of the rest of DRM which is more about
512 	 * physical presence of a display. For eDP, for instance, a display is
513 	 * assumed always present even if the HPD pin is deasserted.
514 	 */
515 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
516 
517 	/**
518 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
519 	 */
520 	unsigned i2c_nack_count;
521 	/**
522 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
523 	 */
524 	unsigned i2c_defer_count;
525 	/**
526 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
527 	 */
528 	struct drm_dp_aux_cec cec;
529 	/**
530 	 * @is_remote: Is this AUX CH actually using sideband messaging.
531 	 */
532 	bool is_remote;
533 
534 	/**
535 	 * @powered_down: If true then the remote endpoint is powered down.
536 	 */
537 	bool powered_down;
538 
539 	/**
540 	 * @no_zero_sized: If the hw can't use zero sized transfers (NVIDIA)
541 	 */
542 	bool no_zero_sized;
543 
544 	/**
545 	 * @dpcd_probe_disabled: If probing before a DPCD access is disabled.
546 	 */
547 	bool dpcd_probe_disabled;
548 };
549 
550 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
551 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
552 void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable);
553 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
554 			 void *buffer, size_t size);
555 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
556 			  void *buffer, size_t size);
557 
558 /**
559  * drm_dp_dpcd_readb() - read a single byte from the DPCD
560  * @aux: DisplayPort AUX channel
561  * @offset: address of the register to read
562  * @valuep: location where the value of the register will be stored
563  *
564  * Returns the number of bytes transferred (1) on success, or a negative
565  * error code on failure. In most of the cases you should be using
566  * drm_dp_dpcd_read_byte() instead.
567  */
568 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
569 					unsigned int offset, u8 *valuep)
570 {
571 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
572 }
573 
574 /**
575  * drm_dp_dpcd_read_data() - read a series of bytes from the DPCD
576  * @aux: DisplayPort AUX channel (SST or MST)
577  * @offset: address of the (first) register to read
578  * @buffer: buffer to store the register values
579  * @size: number of bytes in @buffer
580  *
581  * Returns zero (0) on success, or a negative error
582  * code on failure. -EIO is returned if the request was NAKed by the sink or
583  * if the retry count was exceeded. If not all bytes were transferred, this
584  * function returns -EPROTO. Errors from the underlying AUX channel transfer
585  * function, with the exception of -EBUSY (which causes the transaction to
586  * be retried), are propagated to the caller.
587  */
588 static inline int drm_dp_dpcd_read_data(struct drm_dp_aux *aux,
589 					unsigned int offset,
590 					void *buffer, size_t size)
591 {
592 	int ret;
593 	size_t i;
594 	u8 *buf = buffer;
595 
596 	ret = drm_dp_dpcd_read(aux, offset, buffer, size);
597 	if (ret >= 0) {
598 		if (ret < size)
599 			return -EPROTO;
600 		return 0;
601 	}
602 
603 	/*
604 	 * Workaround for USB-C hubs/adapters with buggy firmware that fail
605 	 * multi-byte AUX reads but work with single-byte reads.
606 	 * Known affected devices:
607 	 * - Lenovo USB-C to VGA adapter (VIA VL817, idVendor=17ef, idProduct=7217)
608 	 * - Dell DA310 USB-C hub (idVendor=413c, idProduct=c010)
609 	 * Attempt byte-by-byte reading as a fallback.
610 	 */
611 	for (i = 0; i < size; i++) {
612 		ret = drm_dp_dpcd_readb(aux, offset + i, &buf[i]);
613 		if (ret < 0)
614 			return ret;
615 	}
616 
617 	return 0;
618 }
619 
620 /**
621  * drm_dp_dpcd_write_data() - write a series of bytes to the DPCD
622  * @aux: DisplayPort AUX channel (SST or MST)
623  * @offset: address of the (first) register to write
624  * @buffer: buffer containing the values to write
625  * @size: number of bytes in @buffer
626  *
627  * Returns zero (0) on success, or a negative error
628  * code on failure. -EIO is returned if the request was NAKed by the sink or
629  * if the retry count was exceeded. If not all bytes were transferred, this
630  * function returns -EPROTO. Errors from the underlying AUX channel transfer
631  * function, with the exception of -EBUSY (which causes the transaction to
632  * be retried), are propagated to the caller.
633  */
634 static inline int drm_dp_dpcd_write_data(struct drm_dp_aux *aux,
635 					 unsigned int offset,
636 					 void *buffer, size_t size)
637 {
638 	int ret;
639 
640 	ret = drm_dp_dpcd_write(aux, offset, buffer, size);
641 	if (ret < 0)
642 		return ret;
643 	if (ret < size)
644 		return -EPROTO;
645 
646 	return 0;
647 }
648 
649 /**
650  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
651  * @aux: DisplayPort AUX channel
652  * @offset: address of the register to write
653  * @value: value to write to the register
654  *
655  * Returns the number of bytes transferred (1) on success, or a negative
656  * error code on failure. In most of the cases you should be using
657  * drm_dp_dpcd_write_byte() instead.
658  */
659 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
660 					 unsigned int offset, u8 value)
661 {
662 	return drm_dp_dpcd_write(aux, offset, &value, 1);
663 }
664 
665 /**
666  * drm_dp_dpcd_read_byte() - read a single byte from the DPCD
667  * @aux: DisplayPort AUX channel
668  * @offset: address of the register to read
669  * @valuep: location where the value of the register will be stored
670  *
671  * Returns zero (0) on success, or a negative error code on failure.
672  */
673 static inline int drm_dp_dpcd_read_byte(struct drm_dp_aux *aux,
674 					unsigned int offset, u8 *valuep)
675 {
676 	return drm_dp_dpcd_read_data(aux, offset, valuep, 1);
677 }
678 
679 /**
680  * drm_dp_dpcd_write_byte() - write a single byte to the DPCD
681  * @aux: DisplayPort AUX channel
682  * @offset: address of the register to write
683  * @value: value to write to the register
684  *
685  * Returns zero (0) on success, or a negative error code on failure.
686  */
687 static inline int drm_dp_dpcd_write_byte(struct drm_dp_aux *aux,
688 					 unsigned int offset, u8 value)
689 {
690 	return drm_dp_dpcd_write_data(aux, offset, &value, 1);
691 }
692 
693 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
694 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
695 
696 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
697 				 u8 status[DP_LINK_STATUS_SIZE]);
698 
699 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
700 				     enum drm_dp_phy dp_phy,
701 				     u8 link_status[DP_LINK_STATUS_SIZE]);
702 int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision);
703 int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision);
704 
705 int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux,
706 			      int vcpid, u8 start_time_slot, u8 time_slot_count);
707 int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux);
708 int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms);
709 
710 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
711 				    u8 real_edid_checksum);
712 
713 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
714 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
715 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
716 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
717 			       const u8 port_cap[4], u8 type);
718 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
719 			       const u8 port_cap[4],
720 			       const struct drm_edid *drm_edid);
721 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
722 				   const u8 port_cap[4]);
723 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
724 				     const u8 port_cap[4],
725 				     const struct drm_edid *drm_edid);
726 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
727 				     const u8 port_cap[4],
728 				     const struct drm_edid *drm_edid);
729 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
730 			      const u8 port_cap[4],
731 			      const struct drm_edid *drm_edid);
732 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
733 				       const u8 port_cap[4]);
734 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
735 					     const u8 port_cap[4]);
736 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
737 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
738 						const u8 port_cap[4]);
739 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
740 void drm_dp_downstream_debug(struct seq_file *m,
741 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
742 			     const u8 port_cap[4],
743 			     const struct drm_edid *drm_edid,
744 			     struct drm_dp_aux *aux);
745 enum drm_mode_subconnector
746 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
747 			 const u8 port_cap[4]);
748 void drm_dp_set_subconnector_property(struct drm_connector *connector,
749 				      enum drm_connector_status status,
750 				      const u8 *dpcd,
751 				      const u8 port_cap[4]);
752 
753 struct drm_dp_desc;
754 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
755 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
756 				const struct drm_dp_desc *desc);
757 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
758 
759 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
760 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
761 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
762 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
763 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
764 			       enum drm_dp_phy dp_phy,
765 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
766 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
767 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
768 int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable);
769 int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count);
770 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
771 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
772 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
773 void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode);
774 
775 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
776 void drm_dp_aux_init(struct drm_dp_aux *aux);
777 int drm_dp_aux_register(struct drm_dp_aux *aux);
778 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
779 
780 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
781 int drm_dp_stop_crc(struct drm_dp_aux *aux);
782 
783 struct drm_dp_dpcd_ident {
784 	u8 oui[3];
785 	u8 device_id[6];
786 	u8 hw_rev;
787 	u8 sw_major_rev;
788 	u8 sw_minor_rev;
789 } __packed;
790 
791 /**
792  * struct drm_dp_desc - DP branch/sink device descriptor
793  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
794  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
795  */
796 struct drm_dp_desc {
797 	struct drm_dp_dpcd_ident ident;
798 	u32 quirks;
799 };
800 
801 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
802 		     bool is_branch);
803 
804 int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy);
805 
806 /**
807  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
808  *
809  * Display Port sink and branch devices in the wild have a variety of bugs, try
810  * to collect them here. The quirks are shared, but it's up to the drivers to
811  * implement workarounds for them.
812  */
813 enum drm_dp_quirk {
814 	/**
815 	 * @DP_DPCD_QUIRK_CONSTANT_N:
816 	 *
817 	 * The device requires main link attributes Mvid and Nvid to be limited
818 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
819 	 */
820 	DP_DPCD_QUIRK_CONSTANT_N,
821 	/**
822 	 * @DP_DPCD_QUIRK_NO_PSR:
823 	 *
824 	 * The device does not support PSR even if reports that it supports or
825 	 * driver still need to implement proper handling for such device.
826 	 */
827 	DP_DPCD_QUIRK_NO_PSR,
828 	/**
829 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
830 	 *
831 	 * The device does not set SINK_COUNT to a non-zero value.
832 	 * The driver should ignore SINK_COUNT during detection. Note that
833 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
834 	 */
835 	DP_DPCD_QUIRK_NO_SINK_COUNT,
836 	/**
837 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
838 	 *
839 	 * The device supports MST DSC despite not supporting Virtual DPCD.
840 	 * The DSC caps can be read from the physical aux instead.
841 	 */
842 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
843 	/**
844 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
845 	 *
846 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
847 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
848 	 */
849 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
850 	/**
851 	 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC:
852 	 *
853 	 * The device applies HBLANK expansion for some modes, but this
854 	 * requires enabling DSC.
855 	 */
856 	DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC,
857 	/**
858 	 * @DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT:
859 	 *
860 	 * The device doesn't support DSC decompression at the maximum DSC
861 	 * pixel throughput and compressed bpp it indicates via its DPCD DSC
862 	 * capabilities. The compressed bpp must be limited above a device
863 	 * specific DSC pixel throughput.
864 	 */
865 	DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT,
866 };
867 
868 /**
869  * drm_dp_has_quirk() - does the DP device have a specific quirk
870  * @desc: Device descriptor filled by drm_dp_read_desc()
871  * @quirk: Quirk to query for
872  *
873  * Return true if DP device identified by @desc has @quirk.
874  */
875 static inline bool
876 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
877 {
878 	return desc->quirks & BIT(quirk);
879 }
880 
881 /**
882  * struct drm_edp_backlight_info - Probed eDP backlight info struct
883  * @pwmgen_bit_count: The pwmgen bit count
884  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
885  * @max: The maximum backlight level that may be set
886  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
887  * @aux_enable: Does the panel support the AUX enable cap?
888  * @aux_set: Does the panel support setting the brightness through AUX?
889  * @luminance_set: Does the panel support setting the brightness through AUX using luminance values?
890  *
891  * This structure contains various data about an eDP backlight, which can be populated by using
892  * drm_edp_backlight_init().
893  */
894 struct drm_edp_backlight_info {
895 	u8 pwmgen_bit_count;
896 	u8 pwm_freq_pre_divider;
897 	u32 max;
898 
899 	bool lsb_reg_used : 1;
900 	bool aux_enable : 1;
901 	bool aux_set : 1;
902 	bool luminance_set : 1;
903 };
904 
905 int
906 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
907 		       u32 max_luminance,
908 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
909 		       u32 *current_level, u8 *current_mode, bool need_luminance);
910 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
911 				u32 level);
912 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
913 			     u32 level);
914 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
915 
916 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
917 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
918 
919 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
920 
921 #else
922 
923 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
924 					     struct drm_dp_aux *aux)
925 {
926 	return 0;
927 }
928 
929 #endif
930 
931 #ifdef CONFIG_DRM_DISPLAY_DP_AUX_CEC
932 void drm_dp_cec_irq(struct drm_dp_aux *aux);
933 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
934 				   struct drm_connector *connector);
935 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
936 void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
937 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
938 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
939 #else
940 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
941 {
942 }
943 
944 static inline void
945 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
946 			      struct drm_connector *connector)
947 {
948 }
949 
950 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
951 {
952 }
953 
954 static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
955 				     u16 source_physical_address)
956 {
957 }
958 
959 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
960 				       const struct edid *edid)
961 {
962 }
963 
964 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
965 {
966 }
967 
968 #endif
969 
970 /**
971  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
972  * @link_rate: Requested Link rate from DPCD 0x219
973  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
974  * @phy_pattern: DP Phy test pattern from DPCD 0x248
975  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
976  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
977  * @enhanced_frame_cap: flag for enhanced frame capability.
978  */
979 struct drm_dp_phy_test_params {
980 	int link_rate;
981 	u8 num_lanes;
982 	u8 phy_pattern;
983 	u8 hbr2_reset[2];
984 	u8 custom80[10];
985 	bool enhanced_frame_cap;
986 };
987 
988 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
989 				struct drm_dp_phy_test_params *data);
990 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
991 				struct drm_dp_phy_test_params *data, u8 dp_rev);
992 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
993 			       const u8 port_cap[4]);
994 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
995 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
996 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
997 				u8 frl_mode);
998 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
999 				u8 frl_type);
1000 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
1001 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
1002 
1003 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
1004 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
1005 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
1006 					   struct drm_connector *connector);
1007 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1008 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1009 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1010 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1011 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
1012 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
1013 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
1014 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1015 					       const u8 port_cap[4], u8 color_spc);
1016 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
1017 
1018 #define DRM_DP_BW_OVERHEAD_MST		BIT(0)
1019 #define DRM_DP_BW_OVERHEAD_UHBR		BIT(1)
1020 #define DRM_DP_BW_OVERHEAD_SSC_REF_CLK	BIT(2)
1021 #define DRM_DP_BW_OVERHEAD_FEC		BIT(3)
1022 #define DRM_DP_BW_OVERHEAD_DSC		BIT(4)
1023 
1024 int drm_dp_bw_overhead(int lane_count, int hactive,
1025 		       int dsc_slice_count,
1026 		       int bpp_x16, unsigned long flags);
1027 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
1028 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
1029 
1030 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
1031 int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count,
1032 			      int bpp_x16, int symbol_size, bool is_mst);
1033 
1034 #endif /* _DRM_DP_HELPER_H_ */
1035