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