xref: /linux/include/drm/display/drm_dp_helper.h (revision eb01fe7abbe2d0b38824d2a93fdb4cc3eaf2ccc1)
1 /*
2  * Copyright © 2008 Keith Packard
3  *
4  * Permission to use, copy, modify, distribute, and sell this software and its
5  * documentation for any purpose is hereby granted without fee, provided that
6  * the above copyright notice appear in all copies and that both that copyright
7  * notice and this permission notice appear in supporting documentation, and
8  * that the name of the copyright holders not be used in advertising or
9  * publicity pertaining to distribution of the software without specific,
10  * written prior permission.  The copyright holders make no representations
11  * about the suitability of this software for any purpose.  It is provided "as
12  * is" without express or implied warranty.
13  *
14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20  * OF THIS SOFTWARE.
21  */
22 
23 #ifndef _DRM_DP_HELPER_H_
24 #define _DRM_DP_HELPER_H_
25 
26 #include <linux/delay.h>
27 #include <linux/i2c.h>
28 
29 #include <drm/display/drm_dp.h>
30 #include <drm/drm_connector.h>
31 
32 struct drm_device;
33 struct drm_dp_aux;
34 struct drm_panel;
35 
36 bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
37 			  int lane_count);
38 bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
39 			      int lane_count);
40 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
41 				     int lane);
42 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
43 					  int lane);
44 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
45 				   int lane);
46 
47 int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
48 				     enum drm_dp_phy dp_phy, bool uhbr);
49 int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
50 				 enum drm_dp_phy dp_phy, bool uhbr);
51 
52 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
53 					    const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
54 void drm_dp_lttpr_link_train_clock_recovery_delay(void);
55 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
56 					const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
57 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
58 					      const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
59 
60 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
61 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
62 					  int lane_count);
63 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
64 					int lane_count);
65 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
66 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
67 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
68 
69 u8 drm_dp_link_rate_to_bw_code(int link_rate);
70 int drm_dp_bw_code_to_link_rate(u8 link_bw);
71 
72 const char *drm_dp_phy_name(enum drm_dp_phy dp_phy);
73 
74 /**
75  * struct drm_dp_vsc_sdp - drm DP VSC SDP
76  *
77  * This structure represents a DP VSC SDP of drm
78  * It is based on DP 1.4 spec [Table 2-116: VSC SDP Header Bytes] and
79  * [Table 2-117: VSC SDP Payload for DB16 through DB18]
80  *
81  * @sdp_type: secondary-data packet type
82  * @revision: revision number
83  * @length: number of valid data bytes
84  * @pixelformat: pixel encoding format
85  * @colorimetry: colorimetry format
86  * @bpc: bit per color
87  * @dynamic_range: dynamic range information
88  * @content_type: CTA-861-G defines content types and expected processing by a sink device
89  */
90 struct drm_dp_vsc_sdp {
91 	unsigned char sdp_type;
92 	unsigned char revision;
93 	unsigned char length;
94 	enum dp_pixelformat pixelformat;
95 	enum dp_colorimetry colorimetry;
96 	int bpc;
97 	enum dp_dynamic_range dynamic_range;
98 	enum dp_content_type content_type;
99 };
100 
101 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
102 
103 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
104 
105 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
106 
107 static inline int
108 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
109 {
110 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
111 }
112 
113 static inline u8
114 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
115 {
116 	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
117 }
118 
119 static inline bool
120 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
121 {
122 	return dpcd[DP_DPCD_REV] >= 0x11 &&
123 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
124 }
125 
126 static inline bool
127 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
128 {
129 	return dpcd[DP_DPCD_REV] >= 0x11 &&
130 		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
131 }
132 
133 static inline bool
134 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
135 {
136 	return dpcd[DP_DPCD_REV] >= 0x12 &&
137 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
138 }
139 
140 static inline bool
141 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
142 {
143 	return dpcd[DP_DPCD_REV] >= 0x11 ||
144 		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
145 }
146 
147 static inline bool
148 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
149 {
150 	return dpcd[DP_DPCD_REV] >= 0x14 &&
151 		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
152 }
153 
154 static inline u8
155 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
156 {
157 	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
158 		DP_TRAINING_PATTERN_MASK;
159 }
160 
161 static inline bool
162 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
163 {
164 	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
165 }
166 
167 /* DP/eDP DSC support */
168 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
169 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
170 				   bool is_edp);
171 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
172 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
173 					 u8 dsc_bpc[3]);
174 
175 static inline bool
176 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
177 {
178 	return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
179 		DP_DSC_DECOMPRESSION_IS_SUPPORTED;
180 }
181 
182 static inline u16
183 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
184 {
185 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
186 		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
187 		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
188 }
189 
190 static inline u32
191 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
192 {
193 	/* Max Slicewidth = Number of Pixels * 320 */
194 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
195 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
196 }
197 
198 /**
199  * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format
200  * @dsc_dpcd : DSC-capability DPCDs of the sink
201  * @output_format: output_format which is to be checked
202  *
203  * Returns true if the sink supports DSC with the given output_format, false otherwise.
204  */
205 static inline bool
206 drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format)
207 {
208 	return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format;
209 }
210 
211 /* Forward Error Correction Support on DP 1.4 */
212 static inline bool
213 drm_dp_sink_supports_fec(const u8 fec_capable)
214 {
215 	return fec_capable & DP_FEC_CAPABLE;
216 }
217 
218 static inline bool
219 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
220 {
221 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
222 }
223 
224 static inline bool
225 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
226 {
227 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
228 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
229 }
230 
231 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
232 static inline bool
233 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
234 {
235 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
236 		DP_MSA_TIMING_PAR_IGNORED;
237 }
238 
239 /**
240  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
241  * @edp_dpcd: The DPCD to check
242  *
243  * Note that currently this function will return %false for panels which support various DPCD
244  * backlight features but which require the brightness be set through PWM, and don't support setting
245  * the brightness level via the DPCD.
246  *
247  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
248  * otherwise
249  */
250 static inline bool
251 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
252 {
253 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
254 }
255 
256 /**
257  * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR
258  * @link_rate: link rate in 10kbits/s units
259  *
260  * Determine if the provided link rate is an UHBR rate.
261  *
262  * Returns: %True if @link_rate is an UHBR rate.
263  */
264 static inline bool drm_dp_is_uhbr_rate(int link_rate)
265 {
266 	return link_rate >= 1000000;
267 }
268 
269 /*
270  * DisplayPort AUX channel
271  */
272 
273 /**
274  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
275  * @address: address of the (first) register to access
276  * @request: contains the type of transaction (see DP_AUX_* macros)
277  * @reply: upon completion, contains the reply type of the transaction
278  * @buffer: pointer to a transmission or reception buffer
279  * @size: size of @buffer
280  */
281 struct drm_dp_aux_msg {
282 	unsigned int address;
283 	u8 request;
284 	u8 reply;
285 	void *buffer;
286 	size_t size;
287 };
288 
289 struct cec_adapter;
290 struct drm_connector;
291 struct drm_edid;
292 
293 /**
294  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
295  * @lock: mutex protecting this struct
296  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
297  * @connector: the connector this CEC adapter is associated with
298  * @unregister_work: unregister the CEC adapter
299  */
300 struct drm_dp_aux_cec {
301 	struct mutex lock;
302 	struct cec_adapter *adap;
303 	struct drm_connector *connector;
304 	struct delayed_work unregister_work;
305 };
306 
307 /**
308  * struct drm_dp_aux - DisplayPort AUX channel
309  *
310  * An AUX channel can also be used to transport I2C messages to a sink. A
311  * typical application of that is to access an EDID that's present in the sink
312  * device. The @transfer() function can also be used to execute such
313  * transactions. The drm_dp_aux_register() function registers an I2C adapter
314  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
315  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
316  * transfers by default; if a partial response is received, the adapter will
317  * drop down to the size given by the partial response for this transaction
318  * only.
319  */
320 struct drm_dp_aux {
321 	/**
322 	 * @name: user-visible name of this AUX channel and the
323 	 * I2C-over-AUX adapter.
324 	 *
325 	 * It's also used to specify the name of the I2C adapter. If set
326 	 * to %NULL, dev_name() of @dev will be used.
327 	 */
328 	const char *name;
329 
330 	/**
331 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
332 	 * communication
333 	 */
334 	struct i2c_adapter ddc;
335 
336 	/**
337 	 * @dev: pointer to struct device that is the parent for this
338 	 * AUX channel.
339 	 */
340 	struct device *dev;
341 
342 	/**
343 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
344 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
345 	 * called.
346 	 *
347 	 * It should be set to the &drm_device that will be using this AUX
348 	 * channel as early as possible. For many graphics drivers this should
349 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
350 	 * this field later so long as it's assigned before calling
351 	 * drm_dp_aux_register().
352 	 */
353 	struct drm_device *drm_dev;
354 
355 	/**
356 	 * @crtc: backpointer to the crtc that is currently using this
357 	 * AUX channel
358 	 */
359 	struct drm_crtc *crtc;
360 
361 	/**
362 	 * @hw_mutex: internal mutex used for locking transfers.
363 	 *
364 	 * Note that if the underlying hardware is shared among multiple
365 	 * channels, the driver needs to do additional locking to
366 	 * prevent concurrent access.
367 	 */
368 	struct mutex hw_mutex;
369 
370 	/**
371 	 * @crc_work: worker that captures CRCs for each frame
372 	 */
373 	struct work_struct crc_work;
374 
375 	/**
376 	 * @crc_count: counter of captured frame CRCs
377 	 */
378 	u8 crc_count;
379 
380 	/**
381 	 * @transfer: transfers a message representing a single AUX
382 	 * transaction.
383 	 *
384 	 * This is a hardware-specific implementation of how
385 	 * transactions are executed that the drivers must provide.
386 	 *
387 	 * A pointer to a &drm_dp_aux_msg structure describing the
388 	 * transaction is passed into this function. Upon success, the
389 	 * implementation should return the number of payload bytes that
390 	 * were transferred, or a negative error-code on failure.
391 	 *
392 	 * Helpers will propagate these errors, with the exception of
393 	 * the %-EBUSY error, which causes a transaction to be retried.
394 	 * On a short, helpers will return %-EPROTO to make it simpler
395 	 * to check for failure.
396 	 *
397 	 * The @transfer() function must only modify the reply field of
398 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
399 	 * helpers assume this is the case.
400 	 *
401 	 * Also note that this callback can be called no matter the
402 	 * state @dev is in and also no matter what state the panel is
403 	 * in. It's expected:
404 	 *
405 	 * - If the @dev providing the AUX bus is currently unpowered then
406 	 *   it will power itself up for the transfer.
407 	 *
408 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
409 	 *   state where it can respond (it's not powered or it's in a
410 	 *   low power state) then this function may return an error, but
411 	 *   not crash. It's up to the caller of this code to make sure that
412 	 *   the panel is powered on if getting an error back is not OK. If a
413 	 *   drm_panel driver is initiating a DP AUX transfer it may power
414 	 *   itself up however it wants. All other code should ensure that
415 	 *   the pre_enable() bridge chain (which eventually calls the
416 	 *   drm_panel prepare function) has powered the panel.
417 	 */
418 	ssize_t (*transfer)(struct drm_dp_aux *aux,
419 			    struct drm_dp_aux_msg *msg);
420 
421 	/**
422 	 * @wait_hpd_asserted: wait for HPD to be asserted
423 	 *
424 	 * This is mainly useful for eDP panels drivers to wait for an eDP
425 	 * panel to finish powering on. This is an optional function.
426 	 *
427 	 * This function will efficiently wait for the HPD signal to be
428 	 * asserted. The `wait_us` parameter that is passed in says that we
429 	 * know that the HPD signal is expected to be asserted within `wait_us`
430 	 * microseconds. This function could wait for longer than `wait_us` if
431 	 * the logic in the DP controller has a long debouncing time. The
432 	 * important thing is that if this function returns success that the
433 	 * DP controller is ready to send AUX transactions.
434 	 *
435 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
436 	 * expired and HPD wasn't asserted. This function should not print
437 	 * timeout errors to the log.
438 	 *
439 	 * The semantics of this function are designed to match the
440 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
441 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
442 	 *
443 	 * NOTE: this function specifically reports the state of the HPD pin
444 	 * that's associated with the DP AUX channel. This is different from
445 	 * the HPD concept in much of the rest of DRM which is more about
446 	 * physical presence of a display. For eDP, for instance, a display is
447 	 * assumed always present even if the HPD pin is deasserted.
448 	 */
449 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
450 
451 	/**
452 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
453 	 */
454 	unsigned i2c_nack_count;
455 	/**
456 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
457 	 */
458 	unsigned i2c_defer_count;
459 	/**
460 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
461 	 */
462 	struct drm_dp_aux_cec cec;
463 	/**
464 	 * @is_remote: Is this AUX CH actually using sideband messaging.
465 	 */
466 	bool is_remote;
467 
468 	/**
469 	 * @powered_down: If true then the remote endpoint is powered down.
470 	 */
471 	bool powered_down;
472 };
473 
474 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
475 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
476 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
477 			 void *buffer, size_t size);
478 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
479 			  void *buffer, size_t size);
480 
481 /**
482  * drm_dp_dpcd_readb() - read a single byte from the DPCD
483  * @aux: DisplayPort AUX channel
484  * @offset: address of the register to read
485  * @valuep: location where the value of the register will be stored
486  *
487  * Returns the number of bytes transferred (1) on success, or a negative
488  * error code on failure.
489  */
490 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
491 					unsigned int offset, u8 *valuep)
492 {
493 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
494 }
495 
496 /**
497  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
498  * @aux: DisplayPort AUX channel
499  * @offset: address of the register to write
500  * @value: value to write to the register
501  *
502  * Returns the number of bytes transferred (1) on success, or a negative
503  * error code on failure.
504  */
505 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
506 					 unsigned int offset, u8 value)
507 {
508 	return drm_dp_dpcd_write(aux, offset, &value, 1);
509 }
510 
511 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
512 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
513 
514 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
515 				 u8 status[DP_LINK_STATUS_SIZE]);
516 
517 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
518 				     enum drm_dp_phy dp_phy,
519 				     u8 link_status[DP_LINK_STATUS_SIZE]);
520 
521 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
522 				    u8 real_edid_checksum);
523 
524 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
525 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
526 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
527 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
528 			       const u8 port_cap[4], u8 type);
529 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
530 			       const u8 port_cap[4],
531 			       const struct drm_edid *drm_edid);
532 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
533 				   const u8 port_cap[4]);
534 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
535 				     const u8 port_cap[4],
536 				     const struct drm_edid *drm_edid);
537 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
538 				     const u8 port_cap[4],
539 				     const struct drm_edid *drm_edid);
540 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
541 			      const u8 port_cap[4],
542 			      const struct drm_edid *drm_edid);
543 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
544 				       const u8 port_cap[4]);
545 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
546 					     const u8 port_cap[4]);
547 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
548 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
549 						const u8 port_cap[4]);
550 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
551 void drm_dp_downstream_debug(struct seq_file *m,
552 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
553 			     const u8 port_cap[4],
554 			     const struct drm_edid *drm_edid,
555 			     struct drm_dp_aux *aux);
556 enum drm_mode_subconnector
557 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
558 			 const u8 port_cap[4]);
559 void drm_dp_set_subconnector_property(struct drm_connector *connector,
560 				      enum drm_connector_status status,
561 				      const u8 *dpcd,
562 				      const u8 port_cap[4]);
563 
564 struct drm_dp_desc;
565 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
566 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
567 				const struct drm_dp_desc *desc);
568 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
569 
570 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
571 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
572 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
573 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
574 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
575 			       enum drm_dp_phy dp_phy,
576 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
577 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
578 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
579 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
580 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
581 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
582 
583 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
584 void drm_dp_aux_init(struct drm_dp_aux *aux);
585 int drm_dp_aux_register(struct drm_dp_aux *aux);
586 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
587 
588 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
589 int drm_dp_stop_crc(struct drm_dp_aux *aux);
590 
591 struct drm_dp_dpcd_ident {
592 	u8 oui[3];
593 	u8 device_id[6];
594 	u8 hw_rev;
595 	u8 sw_major_rev;
596 	u8 sw_minor_rev;
597 } __packed;
598 
599 /**
600  * struct drm_dp_desc - DP branch/sink device descriptor
601  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
602  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
603  */
604 struct drm_dp_desc {
605 	struct drm_dp_dpcd_ident ident;
606 	u32 quirks;
607 };
608 
609 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
610 		     bool is_branch);
611 
612 /**
613  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
614  *
615  * Display Port sink and branch devices in the wild have a variety of bugs, try
616  * to collect them here. The quirks are shared, but it's up to the drivers to
617  * implement workarounds for them.
618  */
619 enum drm_dp_quirk {
620 	/**
621 	 * @DP_DPCD_QUIRK_CONSTANT_N:
622 	 *
623 	 * The device requires main link attributes Mvid and Nvid to be limited
624 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
625 	 */
626 	DP_DPCD_QUIRK_CONSTANT_N,
627 	/**
628 	 * @DP_DPCD_QUIRK_NO_PSR:
629 	 *
630 	 * The device does not support PSR even if reports that it supports or
631 	 * driver still need to implement proper handling for such device.
632 	 */
633 	DP_DPCD_QUIRK_NO_PSR,
634 	/**
635 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
636 	 *
637 	 * The device does not set SINK_COUNT to a non-zero value.
638 	 * The driver should ignore SINK_COUNT during detection. Note that
639 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
640 	 */
641 	DP_DPCD_QUIRK_NO_SINK_COUNT,
642 	/**
643 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
644 	 *
645 	 * The device supports MST DSC despite not supporting Virtual DPCD.
646 	 * The DSC caps can be read from the physical aux instead.
647 	 */
648 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
649 	/**
650 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
651 	 *
652 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
653 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
654 	 */
655 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
656 	/**
657 	 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC:
658 	 *
659 	 * The device applies HBLANK expansion for some modes, but this
660 	 * requires enabling DSC.
661 	 */
662 	DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC,
663 };
664 
665 /**
666  * drm_dp_has_quirk() - does the DP device have a specific quirk
667  * @desc: Device descriptor filled by drm_dp_read_desc()
668  * @quirk: Quirk to query for
669  *
670  * Return true if DP device identified by @desc has @quirk.
671  */
672 static inline bool
673 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
674 {
675 	return desc->quirks & BIT(quirk);
676 }
677 
678 /**
679  * struct drm_edp_backlight_info - Probed eDP backlight info struct
680  * @pwmgen_bit_count: The pwmgen bit count
681  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
682  * @max: The maximum backlight level that may be set
683  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
684  * @aux_enable: Does the panel support the AUX enable cap?
685  * @aux_set: Does the panel support setting the brightness through AUX?
686  *
687  * This structure contains various data about an eDP backlight, which can be populated by using
688  * drm_edp_backlight_init().
689  */
690 struct drm_edp_backlight_info {
691 	u8 pwmgen_bit_count;
692 	u8 pwm_freq_pre_divider;
693 	u16 max;
694 
695 	bool lsb_reg_used : 1;
696 	bool aux_enable : 1;
697 	bool aux_set : 1;
698 };
699 
700 int
701 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
702 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
703 		       u16 *current_level, u8 *current_mode);
704 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
705 				u16 level);
706 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
707 			     u16 level);
708 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
709 
710 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
711 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
712 
713 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
714 
715 #else
716 
717 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
718 					     struct drm_dp_aux *aux)
719 {
720 	return 0;
721 }
722 
723 #endif
724 
725 #ifdef CONFIG_DRM_DP_CEC
726 void drm_dp_cec_irq(struct drm_dp_aux *aux);
727 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
728 				   struct drm_connector *connector);
729 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
730 void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
731 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
732 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
733 #else
734 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
735 {
736 }
737 
738 static inline void
739 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
740 			      struct drm_connector *connector)
741 {
742 }
743 
744 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
745 {
746 }
747 
748 static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
749 				     u16 source_physical_address)
750 {
751 }
752 
753 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
754 				       const struct edid *edid)
755 {
756 }
757 
758 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
759 {
760 }
761 
762 #endif
763 
764 /**
765  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
766  * @link_rate: Requested Link rate from DPCD 0x219
767  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
768  * @phy_pattern: DP Phy test pattern from DPCD 0x248
769  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
770  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
771  * @enhanced_frame_cap: flag for enhanced frame capability.
772  */
773 struct drm_dp_phy_test_params {
774 	int link_rate;
775 	u8 num_lanes;
776 	u8 phy_pattern;
777 	u8 hbr2_reset[2];
778 	u8 custom80[10];
779 	bool enhanced_frame_cap;
780 };
781 
782 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
783 				struct drm_dp_phy_test_params *data);
784 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
785 				struct drm_dp_phy_test_params *data, u8 dp_rev);
786 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
787 			       const u8 port_cap[4]);
788 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
789 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
790 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
791 				u8 frl_mode);
792 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
793 				u8 frl_type);
794 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
795 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
796 
797 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
798 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
799 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
800 					   struct drm_connector *connector);
801 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
802 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
803 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
804 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
805 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
806 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
807 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
808 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
809 					       const u8 port_cap[4], u8 color_spc);
810 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
811 
812 #define DRM_DP_BW_OVERHEAD_MST		BIT(0)
813 #define DRM_DP_BW_OVERHEAD_UHBR		BIT(1)
814 #define DRM_DP_BW_OVERHEAD_SSC_REF_CLK	BIT(2)
815 #define DRM_DP_BW_OVERHEAD_FEC		BIT(3)
816 #define DRM_DP_BW_OVERHEAD_DSC		BIT(4)
817 
818 int drm_dp_bw_overhead(int lane_count, int hactive,
819 		       int dsc_slice_count,
820 		       int bpp_x16, unsigned long flags);
821 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
822 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
823 
824 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
825 
826 #endif /* _DRM_DP_HELPER_H_ */
827