xref: /linux/include/drm/display/drm_dp_helper.h (revision 9cb3542aeeac31b3dd6b5a7d58b9b7d6fe9fd2bc)
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 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
104 
105 static inline int
106 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
107 {
108 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
109 }
110 
111 static inline u8
112 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
113 {
114 	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
115 }
116 
117 static inline bool
118 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
119 {
120 	return dpcd[DP_DPCD_REV] >= 0x11 &&
121 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
122 }
123 
124 static inline bool
125 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
126 {
127 	return dpcd[DP_DPCD_REV] >= 0x11 &&
128 		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
129 }
130 
131 static inline bool
132 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
133 {
134 	return dpcd[DP_DPCD_REV] >= 0x12 &&
135 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
136 }
137 
138 static inline bool
139 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
140 {
141 	return dpcd[DP_DPCD_REV] >= 0x11 ||
142 		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
143 }
144 
145 static inline bool
146 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
147 {
148 	return dpcd[DP_DPCD_REV] >= 0x14 &&
149 		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
150 }
151 
152 static inline u8
153 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
154 {
155 	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
156 		DP_TRAINING_PATTERN_MASK;
157 }
158 
159 static inline bool
160 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
161 {
162 	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
163 }
164 
165 /* DP/eDP DSC support */
166 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
167 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
168 				   bool is_edp);
169 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
170 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
171 					 u8 dsc_bpc[3]);
172 
173 static inline bool
174 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
175 {
176 	return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
177 		DP_DSC_DECOMPRESSION_IS_SUPPORTED;
178 }
179 
180 static inline u16
181 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
182 {
183 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
184 		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
185 		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
186 }
187 
188 static inline u32
189 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
190 {
191 	/* Max Slicewidth = Number of Pixels * 320 */
192 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
193 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
194 }
195 
196 /**
197  * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format
198  * @dsc_dpcd : DSC-capability DPCDs of the sink
199  * @output_format: output_format which is to be checked
200  *
201  * Returns true if the sink supports DSC with the given output_format, false otherwise.
202  */
203 static inline bool
204 drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format)
205 {
206 	return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format;
207 }
208 
209 /* Forward Error Correction Support on DP 1.4 */
210 static inline bool
211 drm_dp_sink_supports_fec(const u8 fec_capable)
212 {
213 	return fec_capable & DP_FEC_CAPABLE;
214 }
215 
216 static inline bool
217 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
218 {
219 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
220 }
221 
222 static inline bool
223 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
224 {
225 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
226 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
227 }
228 
229 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
230 static inline bool
231 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
232 {
233 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
234 		DP_MSA_TIMING_PAR_IGNORED;
235 }
236 
237 /**
238  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
239  * @edp_dpcd: The DPCD to check
240  *
241  * Note that currently this function will return %false for panels which support various DPCD
242  * backlight features but which require the brightness be set through PWM, and don't support setting
243  * the brightness level via the DPCD.
244  *
245  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
246  * otherwise
247  */
248 static inline bool
249 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
250 {
251 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
252 }
253 
254 /**
255  * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR
256  * @link_rate: link rate in 10kbits/s units
257  *
258  * Determine if the provided link rate is an UHBR rate.
259  *
260  * Returns: %True if @link_rate is an UHBR rate.
261  */
262 static inline bool drm_dp_is_uhbr_rate(int link_rate)
263 {
264 	return link_rate >= 1000000;
265 }
266 
267 /*
268  * DisplayPort AUX channel
269  */
270 
271 /**
272  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
273  * @address: address of the (first) register to access
274  * @request: contains the type of transaction (see DP_AUX_* macros)
275  * @reply: upon completion, contains the reply type of the transaction
276  * @buffer: pointer to a transmission or reception buffer
277  * @size: size of @buffer
278  */
279 struct drm_dp_aux_msg {
280 	unsigned int address;
281 	u8 request;
282 	u8 reply;
283 	void *buffer;
284 	size_t size;
285 };
286 
287 struct cec_adapter;
288 struct drm_connector;
289 struct drm_edid;
290 
291 /**
292  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
293  * @lock: mutex protecting this struct
294  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
295  * @connector: the connector this CEC adapter is associated with
296  * @unregister_work: unregister the CEC adapter
297  */
298 struct drm_dp_aux_cec {
299 	struct mutex lock;
300 	struct cec_adapter *adap;
301 	struct drm_connector *connector;
302 	struct delayed_work unregister_work;
303 };
304 
305 /**
306  * struct drm_dp_aux - DisplayPort AUX channel
307  *
308  * An AUX channel can also be used to transport I2C messages to a sink. A
309  * typical application of that is to access an EDID that's present in the sink
310  * device. The @transfer() function can also be used to execute such
311  * transactions. The drm_dp_aux_register() function registers an I2C adapter
312  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
313  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
314  * transfers by default; if a partial response is received, the adapter will
315  * drop down to the size given by the partial response for this transaction
316  * only.
317  */
318 struct drm_dp_aux {
319 	/**
320 	 * @name: user-visible name of this AUX channel and the
321 	 * I2C-over-AUX adapter.
322 	 *
323 	 * It's also used to specify the name of the I2C adapter. If set
324 	 * to %NULL, dev_name() of @dev will be used.
325 	 */
326 	const char *name;
327 
328 	/**
329 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
330 	 * communication
331 	 */
332 	struct i2c_adapter ddc;
333 
334 	/**
335 	 * @dev: pointer to struct device that is the parent for this
336 	 * AUX channel.
337 	 */
338 	struct device *dev;
339 
340 	/**
341 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
342 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
343 	 * called.
344 	 *
345 	 * It should be set to the &drm_device that will be using this AUX
346 	 * channel as early as possible. For many graphics drivers this should
347 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
348 	 * this field later so long as it's assigned before calling
349 	 * drm_dp_aux_register().
350 	 */
351 	struct drm_device *drm_dev;
352 
353 	/**
354 	 * @crtc: backpointer to the crtc that is currently using this
355 	 * AUX channel
356 	 */
357 	struct drm_crtc *crtc;
358 
359 	/**
360 	 * @hw_mutex: internal mutex used for locking transfers.
361 	 *
362 	 * Note that if the underlying hardware is shared among multiple
363 	 * channels, the driver needs to do additional locking to
364 	 * prevent concurrent access.
365 	 */
366 	struct mutex hw_mutex;
367 
368 	/**
369 	 * @crc_work: worker that captures CRCs for each frame
370 	 */
371 	struct work_struct crc_work;
372 
373 	/**
374 	 * @crc_count: counter of captured frame CRCs
375 	 */
376 	u8 crc_count;
377 
378 	/**
379 	 * @transfer: transfers a message representing a single AUX
380 	 * transaction.
381 	 *
382 	 * This is a hardware-specific implementation of how
383 	 * transactions are executed that the drivers must provide.
384 	 *
385 	 * A pointer to a &drm_dp_aux_msg structure describing the
386 	 * transaction is passed into this function. Upon success, the
387 	 * implementation should return the number of payload bytes that
388 	 * were transferred, or a negative error-code on failure.
389 	 *
390 	 * Helpers will propagate these errors, with the exception of
391 	 * the %-EBUSY error, which causes a transaction to be retried.
392 	 * On a short, helpers will return %-EPROTO to make it simpler
393 	 * to check for failure.
394 	 *
395 	 * The @transfer() function must only modify the reply field of
396 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
397 	 * helpers assume this is the case.
398 	 *
399 	 * Also note that this callback can be called no matter the
400 	 * state @dev is in and also no matter what state the panel is
401 	 * in. It's expected:
402 	 *
403 	 * - If the @dev providing the AUX bus is currently unpowered then
404 	 *   it will power itself up for the transfer.
405 	 *
406 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
407 	 *   state where it can respond (it's not powered or it's in a
408 	 *   low power state) then this function may return an error, but
409 	 *   not crash. It's up to the caller of this code to make sure that
410 	 *   the panel is powered on if getting an error back is not OK. If a
411 	 *   drm_panel driver is initiating a DP AUX transfer it may power
412 	 *   itself up however it wants. All other code should ensure that
413 	 *   the pre_enable() bridge chain (which eventually calls the
414 	 *   drm_panel prepare function) has powered the panel.
415 	 */
416 	ssize_t (*transfer)(struct drm_dp_aux *aux,
417 			    struct drm_dp_aux_msg *msg);
418 
419 	/**
420 	 * @wait_hpd_asserted: wait for HPD to be asserted
421 	 *
422 	 * This is mainly useful for eDP panels drivers to wait for an eDP
423 	 * panel to finish powering on. This is an optional function.
424 	 *
425 	 * This function will efficiently wait for the HPD signal to be
426 	 * asserted. The `wait_us` parameter that is passed in says that we
427 	 * know that the HPD signal is expected to be asserted within `wait_us`
428 	 * microseconds. This function could wait for longer than `wait_us` if
429 	 * the logic in the DP controller has a long debouncing time. The
430 	 * important thing is that if this function returns success that the
431 	 * DP controller is ready to send AUX transactions.
432 	 *
433 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
434 	 * expired and HPD wasn't asserted. This function should not print
435 	 * timeout errors to the log.
436 	 *
437 	 * The semantics of this function are designed to match the
438 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
439 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
440 	 *
441 	 * NOTE: this function specifically reports the state of the HPD pin
442 	 * that's associated with the DP AUX channel. This is different from
443 	 * the HPD concept in much of the rest of DRM which is more about
444 	 * physical presence of a display. For eDP, for instance, a display is
445 	 * assumed always present even if the HPD pin is deasserted.
446 	 */
447 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
448 
449 	/**
450 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
451 	 */
452 	unsigned i2c_nack_count;
453 	/**
454 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
455 	 */
456 	unsigned i2c_defer_count;
457 	/**
458 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
459 	 */
460 	struct drm_dp_aux_cec cec;
461 	/**
462 	 * @is_remote: Is this AUX CH actually using sideband messaging.
463 	 */
464 	bool is_remote;
465 };
466 
467 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
468 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
469 			 void *buffer, size_t size);
470 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
471 			  void *buffer, size_t size);
472 
473 /**
474  * drm_dp_dpcd_readb() - read a single byte from the DPCD
475  * @aux: DisplayPort AUX channel
476  * @offset: address of the register to read
477  * @valuep: location where the value of the register will be stored
478  *
479  * Returns the number of bytes transferred (1) on success, or a negative
480  * error code on failure.
481  */
482 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
483 					unsigned int offset, u8 *valuep)
484 {
485 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
486 }
487 
488 /**
489  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
490  * @aux: DisplayPort AUX channel
491  * @offset: address of the register to write
492  * @value: value to write to the register
493  *
494  * Returns the number of bytes transferred (1) on success, or a negative
495  * error code on failure.
496  */
497 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
498 					 unsigned int offset, u8 value)
499 {
500 	return drm_dp_dpcd_write(aux, offset, &value, 1);
501 }
502 
503 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
504 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
505 
506 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
507 				 u8 status[DP_LINK_STATUS_SIZE]);
508 
509 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
510 				     enum drm_dp_phy dp_phy,
511 				     u8 link_status[DP_LINK_STATUS_SIZE]);
512 
513 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
514 				    u8 real_edid_checksum);
515 
516 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
517 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
518 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
519 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
520 			       const u8 port_cap[4], u8 type);
521 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
522 			       const u8 port_cap[4],
523 			       const struct drm_edid *drm_edid);
524 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
525 				   const u8 port_cap[4]);
526 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
527 				     const u8 port_cap[4],
528 				     const struct drm_edid *drm_edid);
529 int drm_dp_downstream_min_tmds_clock(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_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
533 			      const u8 port_cap[4],
534 			      const struct drm_edid *drm_edid);
535 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
536 				       const u8 port_cap[4]);
537 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
538 					     const u8 port_cap[4]);
539 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
540 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
541 						const u8 port_cap[4]);
542 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
543 void drm_dp_downstream_debug(struct seq_file *m,
544 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
545 			     const u8 port_cap[4],
546 			     const struct drm_edid *drm_edid,
547 			     struct drm_dp_aux *aux);
548 enum drm_mode_subconnector
549 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
550 			 const u8 port_cap[4]);
551 void drm_dp_set_subconnector_property(struct drm_connector *connector,
552 				      enum drm_connector_status status,
553 				      const u8 *dpcd,
554 				      const u8 port_cap[4]);
555 
556 struct drm_dp_desc;
557 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
558 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
559 				const struct drm_dp_desc *desc);
560 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
561 
562 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
563 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
564 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
565 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
566 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
567 			       enum drm_dp_phy dp_phy,
568 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
569 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
570 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
571 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
572 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
573 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
574 
575 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
576 void drm_dp_aux_init(struct drm_dp_aux *aux);
577 int drm_dp_aux_register(struct drm_dp_aux *aux);
578 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
579 
580 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
581 int drm_dp_stop_crc(struct drm_dp_aux *aux);
582 
583 struct drm_dp_dpcd_ident {
584 	u8 oui[3];
585 	u8 device_id[6];
586 	u8 hw_rev;
587 	u8 sw_major_rev;
588 	u8 sw_minor_rev;
589 } __packed;
590 
591 /**
592  * struct drm_dp_desc - DP branch/sink device descriptor
593  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
594  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
595  */
596 struct drm_dp_desc {
597 	struct drm_dp_dpcd_ident ident;
598 	u32 quirks;
599 };
600 
601 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
602 		     bool is_branch);
603 
604 /**
605  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
606  *
607  * Display Port sink and branch devices in the wild have a variety of bugs, try
608  * to collect them here. The quirks are shared, but it's up to the drivers to
609  * implement workarounds for them.
610  */
611 enum drm_dp_quirk {
612 	/**
613 	 * @DP_DPCD_QUIRK_CONSTANT_N:
614 	 *
615 	 * The device requires main link attributes Mvid and Nvid to be limited
616 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
617 	 */
618 	DP_DPCD_QUIRK_CONSTANT_N,
619 	/**
620 	 * @DP_DPCD_QUIRK_NO_PSR:
621 	 *
622 	 * The device does not support PSR even if reports that it supports or
623 	 * driver still need to implement proper handling for such device.
624 	 */
625 	DP_DPCD_QUIRK_NO_PSR,
626 	/**
627 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
628 	 *
629 	 * The device does not set SINK_COUNT to a non-zero value.
630 	 * The driver should ignore SINK_COUNT during detection. Note that
631 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
632 	 */
633 	DP_DPCD_QUIRK_NO_SINK_COUNT,
634 	/**
635 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
636 	 *
637 	 * The device supports MST DSC despite not supporting Virtual DPCD.
638 	 * The DSC caps can be read from the physical aux instead.
639 	 */
640 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
641 	/**
642 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
643 	 *
644 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
645 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
646 	 */
647 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
648 	/**
649 	 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC:
650 	 *
651 	 * The device applies HBLANK expansion for some modes, but this
652 	 * requires enabling DSC.
653 	 */
654 	DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC,
655 };
656 
657 /**
658  * drm_dp_has_quirk() - does the DP device have a specific quirk
659  * @desc: Device descriptor filled by drm_dp_read_desc()
660  * @quirk: Quirk to query for
661  *
662  * Return true if DP device identified by @desc has @quirk.
663  */
664 static inline bool
665 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
666 {
667 	return desc->quirks & BIT(quirk);
668 }
669 
670 /**
671  * struct drm_edp_backlight_info - Probed eDP backlight info struct
672  * @pwmgen_bit_count: The pwmgen bit count
673  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
674  * @max: The maximum backlight level that may be set
675  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
676  * @aux_enable: Does the panel support the AUX enable cap?
677  * @aux_set: Does the panel support setting the brightness through AUX?
678  *
679  * This structure contains various data about an eDP backlight, which can be populated by using
680  * drm_edp_backlight_init().
681  */
682 struct drm_edp_backlight_info {
683 	u8 pwmgen_bit_count;
684 	u8 pwm_freq_pre_divider;
685 	u16 max;
686 
687 	bool lsb_reg_used : 1;
688 	bool aux_enable : 1;
689 	bool aux_set : 1;
690 };
691 
692 int
693 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
694 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
695 		       u16 *current_level, u8 *current_mode);
696 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
697 				u16 level);
698 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
699 			     u16 level);
700 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
701 
702 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
703 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
704 
705 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
706 
707 #else
708 
709 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
710 					     struct drm_dp_aux *aux)
711 {
712 	return 0;
713 }
714 
715 #endif
716 
717 #ifdef CONFIG_DRM_DP_CEC
718 void drm_dp_cec_irq(struct drm_dp_aux *aux);
719 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
720 				   struct drm_connector *connector);
721 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
722 void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
723 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
724 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
725 #else
726 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
727 {
728 }
729 
730 static inline void
731 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
732 			      struct drm_connector *connector)
733 {
734 }
735 
736 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
737 {
738 }
739 
740 static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
741 				     u16 source_physical_address)
742 {
743 }
744 
745 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
746 				       const struct edid *edid)
747 {
748 }
749 
750 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
751 {
752 }
753 
754 #endif
755 
756 /**
757  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
758  * @link_rate: Requested Link rate from DPCD 0x219
759  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
760  * @phy_pattern: DP Phy test pattern from DPCD 0x248
761  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
762  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
763  * @enhanced_frame_cap: flag for enhanced frame capability.
764  */
765 struct drm_dp_phy_test_params {
766 	int link_rate;
767 	u8 num_lanes;
768 	u8 phy_pattern;
769 	u8 hbr2_reset[2];
770 	u8 custom80[10];
771 	bool enhanced_frame_cap;
772 };
773 
774 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
775 				struct drm_dp_phy_test_params *data);
776 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
777 				struct drm_dp_phy_test_params *data, u8 dp_rev);
778 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
779 			       const u8 port_cap[4]);
780 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
781 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
782 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
783 				u8 frl_mode);
784 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
785 				u8 frl_type);
786 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
787 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
788 
789 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
790 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
791 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
792 					   struct drm_connector *connector);
793 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
794 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
795 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
796 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
797 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
798 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
799 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
800 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
801 					       const u8 port_cap[4], u8 color_spc);
802 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
803 
804 #define DRM_DP_BW_OVERHEAD_MST		BIT(0)
805 #define DRM_DP_BW_OVERHEAD_UHBR		BIT(1)
806 #define DRM_DP_BW_OVERHEAD_SSC_REF_CLK	BIT(2)
807 #define DRM_DP_BW_OVERHEAD_FEC		BIT(3)
808 #define DRM_DP_BW_OVERHEAD_DSC		BIT(4)
809 
810 int drm_dp_bw_overhead(int lane_count, int hactive,
811 		       int dsc_slice_count,
812 		       int bpp_x16, unsigned long flags);
813 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
814 
815 #endif /* _DRM_DP_HELPER_H_ */
816