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(const char *level, struct device *dev,
102 			const struct drm_dp_vsc_sdp *vsc);
103 
104 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
105 
106 static inline int
107 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
108 {
109 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
110 }
111 
112 static inline u8
113 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
114 {
115 	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
116 }
117 
118 static inline bool
119 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
120 {
121 	return dpcd[DP_DPCD_REV] >= 0x11 &&
122 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
123 }
124 
125 static inline bool
126 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
127 {
128 	return dpcd[DP_DPCD_REV] >= 0x11 &&
129 		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
130 }
131 
132 static inline bool
133 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
134 {
135 	return dpcd[DP_DPCD_REV] >= 0x12 &&
136 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
137 }
138 
139 static inline bool
140 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
141 {
142 	return dpcd[DP_DPCD_REV] >= 0x11 ||
143 		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
144 }
145 
146 static inline bool
147 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
148 {
149 	return dpcd[DP_DPCD_REV] >= 0x14 &&
150 		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
151 }
152 
153 static inline u8
154 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
155 {
156 	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
157 		DP_TRAINING_PATTERN_MASK;
158 }
159 
160 static inline bool
161 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
162 {
163 	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
164 }
165 
166 /* DP/eDP DSC support */
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  * DisplayPort AUX channel
256  */
257 
258 /**
259  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
260  * @address: address of the (first) register to access
261  * @request: contains the type of transaction (see DP_AUX_* macros)
262  * @reply: upon completion, contains the reply type of the transaction
263  * @buffer: pointer to a transmission or reception buffer
264  * @size: size of @buffer
265  */
266 struct drm_dp_aux_msg {
267 	unsigned int address;
268 	u8 request;
269 	u8 reply;
270 	void *buffer;
271 	size_t size;
272 };
273 
274 struct cec_adapter;
275 struct edid;
276 struct drm_connector;
277 
278 /**
279  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
280  * @lock: mutex protecting this struct
281  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
282  * @connector: the connector this CEC adapter is associated with
283  * @unregister_work: unregister the CEC adapter
284  */
285 struct drm_dp_aux_cec {
286 	struct mutex lock;
287 	struct cec_adapter *adap;
288 	struct drm_connector *connector;
289 	struct delayed_work unregister_work;
290 };
291 
292 /**
293  * struct drm_dp_aux - DisplayPort AUX channel
294  *
295  * An AUX channel can also be used to transport I2C messages to a sink. A
296  * typical application of that is to access an EDID that's present in the sink
297  * device. The @transfer() function can also be used to execute such
298  * transactions. The drm_dp_aux_register() function registers an I2C adapter
299  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
300  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
301  * transfers by default; if a partial response is received, the adapter will
302  * drop down to the size given by the partial response for this transaction
303  * only.
304  */
305 struct drm_dp_aux {
306 	/**
307 	 * @name: user-visible name of this AUX channel and the
308 	 * I2C-over-AUX adapter.
309 	 *
310 	 * It's also used to specify the name of the I2C adapter. If set
311 	 * to %NULL, dev_name() of @dev will be used.
312 	 */
313 	const char *name;
314 
315 	/**
316 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
317 	 * communication
318 	 */
319 	struct i2c_adapter ddc;
320 
321 	/**
322 	 * @dev: pointer to struct device that is the parent for this
323 	 * AUX channel.
324 	 */
325 	struct device *dev;
326 
327 	/**
328 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
329 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
330 	 * called.
331 	 *
332 	 * It should be set to the &drm_device that will be using this AUX
333 	 * channel as early as possible. For many graphics drivers this should
334 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
335 	 * this field later so long as it's assigned before calling
336 	 * drm_dp_aux_register().
337 	 */
338 	struct drm_device *drm_dev;
339 
340 	/**
341 	 * @crtc: backpointer to the crtc that is currently using this
342 	 * AUX channel
343 	 */
344 	struct drm_crtc *crtc;
345 
346 	/**
347 	 * @hw_mutex: internal mutex used for locking transfers.
348 	 *
349 	 * Note that if the underlying hardware is shared among multiple
350 	 * channels, the driver needs to do additional locking to
351 	 * prevent concurrent access.
352 	 */
353 	struct mutex hw_mutex;
354 
355 	/**
356 	 * @crc_work: worker that captures CRCs for each frame
357 	 */
358 	struct work_struct crc_work;
359 
360 	/**
361 	 * @crc_count: counter of captured frame CRCs
362 	 */
363 	u8 crc_count;
364 
365 	/**
366 	 * @transfer: transfers a message representing a single AUX
367 	 * transaction.
368 	 *
369 	 * This is a hardware-specific implementation of how
370 	 * transactions are executed that the drivers must provide.
371 	 *
372 	 * A pointer to a &drm_dp_aux_msg structure describing the
373 	 * transaction is passed into this function. Upon success, the
374 	 * implementation should return the number of payload bytes that
375 	 * were transferred, or a negative error-code on failure.
376 	 *
377 	 * Helpers will propagate these errors, with the exception of
378 	 * the %-EBUSY error, which causes a transaction to be retried.
379 	 * On a short, helpers will return %-EPROTO to make it simpler
380 	 * to check for failure.
381 	 *
382 	 * The @transfer() function must only modify the reply field of
383 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
384 	 * helpers assume this is the case.
385 	 *
386 	 * Also note that this callback can be called no matter the
387 	 * state @dev is in and also no matter what state the panel is
388 	 * in. It's expected:
389 	 *
390 	 * - If the @dev providing the AUX bus is currently unpowered then
391 	 *   it will power itself up for the transfer.
392 	 *
393 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
394 	 *   state where it can respond (it's not powered or it's in a
395 	 *   low power state) then this function may return an error, but
396 	 *   not crash. It's up to the caller of this code to make sure that
397 	 *   the panel is powered on if getting an error back is not OK. If a
398 	 *   drm_panel driver is initiating a DP AUX transfer it may power
399 	 *   itself up however it wants. All other code should ensure that
400 	 *   the pre_enable() bridge chain (which eventually calls the
401 	 *   drm_panel prepare function) has powered the panel.
402 	 */
403 	ssize_t (*transfer)(struct drm_dp_aux *aux,
404 			    struct drm_dp_aux_msg *msg);
405 
406 	/**
407 	 * @wait_hpd_asserted: wait for HPD to be asserted
408 	 *
409 	 * This is mainly useful for eDP panels drivers to wait for an eDP
410 	 * panel to finish powering on. This is an optional function.
411 	 *
412 	 * This function will efficiently wait for the HPD signal to be
413 	 * asserted. The `wait_us` parameter that is passed in says that we
414 	 * know that the HPD signal is expected to be asserted within `wait_us`
415 	 * microseconds. This function could wait for longer than `wait_us` if
416 	 * the logic in the DP controller has a long debouncing time. The
417 	 * important thing is that if this function returns success that the
418 	 * DP controller is ready to send AUX transactions.
419 	 *
420 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
421 	 * expired and HPD wasn't asserted. This function should not print
422 	 * timeout errors to the log.
423 	 *
424 	 * The semantics of this function are designed to match the
425 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
426 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
427 	 *
428 	 * NOTE: this function specifically reports the state of the HPD pin
429 	 * that's associated with the DP AUX channel. This is different from
430 	 * the HPD concept in much of the rest of DRM which is more about
431 	 * physical presence of a display. For eDP, for instance, a display is
432 	 * assumed always present even if the HPD pin is deasserted.
433 	 */
434 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
435 
436 	/**
437 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
438 	 */
439 	unsigned i2c_nack_count;
440 	/**
441 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
442 	 */
443 	unsigned i2c_defer_count;
444 	/**
445 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
446 	 */
447 	struct drm_dp_aux_cec cec;
448 	/**
449 	 * @is_remote: Is this AUX CH actually using sideband messaging.
450 	 */
451 	bool is_remote;
452 
453 	/**
454 	 * @powered_down: If true then the remote endpoint is powered down.
455 	 */
456 	bool powered_down;
457 };
458 
459 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
460 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
461 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
462 			 void *buffer, size_t size);
463 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
464 			  void *buffer, size_t size);
465 
466 /**
467  * drm_dp_dpcd_readb() - read a single byte from the DPCD
468  * @aux: DisplayPort AUX channel
469  * @offset: address of the register to read
470  * @valuep: location where the value of the register will be stored
471  *
472  * Returns the number of bytes transferred (1) on success, or a negative
473  * error code on failure.
474  */
475 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
476 					unsigned int offset, u8 *valuep)
477 {
478 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
479 }
480 
481 /**
482  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
483  * @aux: DisplayPort AUX channel
484  * @offset: address of the register to write
485  * @value: value to write to the register
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_writeb(struct drm_dp_aux *aux,
491 					 unsigned int offset, u8 value)
492 {
493 	return drm_dp_dpcd_write(aux, offset, &value, 1);
494 }
495 
496 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
497 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
498 
499 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
500 				 u8 status[DP_LINK_STATUS_SIZE]);
501 
502 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
503 				     enum drm_dp_phy dp_phy,
504 				     u8 link_status[DP_LINK_STATUS_SIZE]);
505 
506 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
507 				    u8 real_edid_checksum);
508 
509 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
510 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
511 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
512 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
513 			       const u8 port_cap[4], u8 type);
514 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
515 			       const u8 port_cap[4],
516 			       const struct edid *edid);
517 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
518 				   const u8 port_cap[4]);
519 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
520 				     const u8 port_cap[4],
521 				     const struct edid *edid);
522 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
523 				     const u8 port_cap[4],
524 				     const struct edid *edid);
525 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
526 			      const u8 port_cap[4],
527 			      const struct edid *edid);
528 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
529 				       const u8 port_cap[4]);
530 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
531 					     const u8 port_cap[4]);
532 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
533 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
534 						const u8 port_cap[4]);
535 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
536 void drm_dp_downstream_debug(struct seq_file *m,
537 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
538 			     const u8 port_cap[4],
539 			     const struct edid *edid,
540 			     struct drm_dp_aux *aux);
541 enum drm_mode_subconnector
542 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
543 			 const u8 port_cap[4]);
544 void drm_dp_set_subconnector_property(struct drm_connector *connector,
545 				      enum drm_connector_status status,
546 				      const u8 *dpcd,
547 				      const u8 port_cap[4]);
548 
549 struct drm_dp_desc;
550 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
551 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
552 				const struct drm_dp_desc *desc);
553 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
554 
555 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
556 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
557 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
558 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
559 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
560 			       enum drm_dp_phy dp_phy,
561 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
562 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
563 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
564 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
565 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
566 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
567 
568 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
569 void drm_dp_aux_init(struct drm_dp_aux *aux);
570 int drm_dp_aux_register(struct drm_dp_aux *aux);
571 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
572 
573 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
574 int drm_dp_stop_crc(struct drm_dp_aux *aux);
575 
576 struct drm_dp_dpcd_ident {
577 	u8 oui[3];
578 	u8 device_id[6];
579 	u8 hw_rev;
580 	u8 sw_major_rev;
581 	u8 sw_minor_rev;
582 } __packed;
583 
584 /**
585  * struct drm_dp_desc - DP branch/sink device descriptor
586  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
587  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
588  */
589 struct drm_dp_desc {
590 	struct drm_dp_dpcd_ident ident;
591 	u32 quirks;
592 };
593 
594 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
595 		     bool is_branch);
596 
597 /**
598  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
599  *
600  * Display Port sink and branch devices in the wild have a variety of bugs, try
601  * to collect them here. The quirks are shared, but it's up to the drivers to
602  * implement workarounds for them.
603  */
604 enum drm_dp_quirk {
605 	/**
606 	 * @DP_DPCD_QUIRK_CONSTANT_N:
607 	 *
608 	 * The device requires main link attributes Mvid and Nvid to be limited
609 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
610 	 */
611 	DP_DPCD_QUIRK_CONSTANT_N,
612 	/**
613 	 * @DP_DPCD_QUIRK_NO_PSR:
614 	 *
615 	 * The device does not support PSR even if reports that it supports or
616 	 * driver still need to implement proper handling for such device.
617 	 */
618 	DP_DPCD_QUIRK_NO_PSR,
619 	/**
620 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
621 	 *
622 	 * The device does not set SINK_COUNT to a non-zero value.
623 	 * The driver should ignore SINK_COUNT during detection. Note that
624 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
625 	 */
626 	DP_DPCD_QUIRK_NO_SINK_COUNT,
627 	/**
628 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
629 	 *
630 	 * The device supports MST DSC despite not supporting Virtual DPCD.
631 	 * The DSC caps can be read from the physical aux instead.
632 	 */
633 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
634 	/**
635 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
636 	 *
637 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
638 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
639 	 */
640 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
641 };
642 
643 /**
644  * drm_dp_has_quirk() - does the DP device have a specific quirk
645  * @desc: Device descriptor filled by drm_dp_read_desc()
646  * @quirk: Quirk to query for
647  *
648  * Return true if DP device identified by @desc has @quirk.
649  */
650 static inline bool
651 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
652 {
653 	return desc->quirks & BIT(quirk);
654 }
655 
656 /**
657  * struct drm_edp_backlight_info - Probed eDP backlight info struct
658  * @pwmgen_bit_count: The pwmgen bit count
659  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
660  * @max: The maximum backlight level that may be set
661  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
662  * @aux_enable: Does the panel support the AUX enable cap?
663  * @aux_set: Does the panel support setting the brightness through AUX?
664  *
665  * This structure contains various data about an eDP backlight, which can be populated by using
666  * drm_edp_backlight_init().
667  */
668 struct drm_edp_backlight_info {
669 	u8 pwmgen_bit_count;
670 	u8 pwm_freq_pre_divider;
671 	u16 max;
672 
673 	bool lsb_reg_used : 1;
674 	bool aux_enable : 1;
675 	bool aux_set : 1;
676 };
677 
678 int
679 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
680 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
681 		       u16 *current_level, u8 *current_mode);
682 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
683 				u16 level);
684 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
685 			     u16 level);
686 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
687 
688 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
689 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
690 
691 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
692 
693 #else
694 
695 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
696 					     struct drm_dp_aux *aux)
697 {
698 	return 0;
699 }
700 
701 #endif
702 
703 #ifdef CONFIG_DRM_DP_CEC
704 void drm_dp_cec_irq(struct drm_dp_aux *aux);
705 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
706 				   struct drm_connector *connector);
707 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
708 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
709 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
710 #else
711 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
712 {
713 }
714 
715 static inline void
716 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
717 			      struct drm_connector *connector)
718 {
719 }
720 
721 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
722 {
723 }
724 
725 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
726 				       const struct edid *edid)
727 {
728 }
729 
730 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
731 {
732 }
733 
734 #endif
735 
736 /**
737  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
738  * @link_rate: Requested Link rate from DPCD 0x219
739  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
740  * @phy_pattern: DP Phy test pattern from DPCD 0x248
741  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
742  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
743  * @enhanced_frame_cap: flag for enhanced frame capability.
744  */
745 struct drm_dp_phy_test_params {
746 	int link_rate;
747 	u8 num_lanes;
748 	u8 phy_pattern;
749 	u8 hbr2_reset[2];
750 	u8 custom80[10];
751 	bool enhanced_frame_cap;
752 };
753 
754 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
755 				struct drm_dp_phy_test_params *data);
756 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
757 				struct drm_dp_phy_test_params *data, u8 dp_rev);
758 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
759 			       const u8 port_cap[4]);
760 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
761 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
762 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
763 				u8 frl_mode);
764 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
765 				u8 frl_type);
766 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
767 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
768 
769 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
770 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
771 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
772 					   struct drm_connector *connector);
773 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
774 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
775 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
776 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
777 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
778 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
779 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
780 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
781 					       const u8 port_cap[4], u8 color_spc);
782 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
783 
784 #endif /* _DRM_DP_HELPER_H_ */
785