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 <<
186 		 DP_DSC_MAX_BITS_PER_PIXEL_HI_SHIFT);
187 }
188 
189 static inline u32
190 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
191 {
192 	/* Max Slicewidth = Number of Pixels * 320 */
193 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
194 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
195 }
196 
197 /* Forward Error Correction Support on DP 1.4 */
198 static inline bool
199 drm_dp_sink_supports_fec(const u8 fec_capable)
200 {
201 	return fec_capable & DP_FEC_CAPABLE;
202 }
203 
204 static inline bool
205 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
206 {
207 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
208 }
209 
210 static inline bool
211 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
212 {
213 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
214 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
215 }
216 
217 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
218 static inline bool
219 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
220 {
221 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
222 		DP_MSA_TIMING_PAR_IGNORED;
223 }
224 
225 /**
226  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
227  * @edp_dpcd: The DPCD to check
228  *
229  * Note that currently this function will return %false for panels which support various DPCD
230  * backlight features but which require the brightness be set through PWM, and don't support setting
231  * the brightness level via the DPCD.
232  *
233  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
234  * otherwise
235  */
236 static inline bool
237 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
238 {
239 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
240 }
241 
242 /*
243  * DisplayPort AUX channel
244  */
245 
246 /**
247  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
248  * @address: address of the (first) register to access
249  * @request: contains the type of transaction (see DP_AUX_* macros)
250  * @reply: upon completion, contains the reply type of the transaction
251  * @buffer: pointer to a transmission or reception buffer
252  * @size: size of @buffer
253  */
254 struct drm_dp_aux_msg {
255 	unsigned int address;
256 	u8 request;
257 	u8 reply;
258 	void *buffer;
259 	size_t size;
260 };
261 
262 struct cec_adapter;
263 struct edid;
264 struct drm_connector;
265 
266 /**
267  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
268  * @lock: mutex protecting this struct
269  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
270  * @connector: the connector this CEC adapter is associated with
271  * @unregister_work: unregister the CEC adapter
272  */
273 struct drm_dp_aux_cec {
274 	struct mutex lock;
275 	struct cec_adapter *adap;
276 	struct drm_connector *connector;
277 	struct delayed_work unregister_work;
278 };
279 
280 /**
281  * struct drm_dp_aux - DisplayPort AUX channel
282  *
283  * An AUX channel can also be used to transport I2C messages to a sink. A
284  * typical application of that is to access an EDID that's present in the sink
285  * device. The @transfer() function can also be used to execute such
286  * transactions. The drm_dp_aux_register() function registers an I2C adapter
287  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
288  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
289  * transfers by default; if a partial response is received, the adapter will
290  * drop down to the size given by the partial response for this transaction
291  * only.
292  */
293 struct drm_dp_aux {
294 	/**
295 	 * @name: user-visible name of this AUX channel and the
296 	 * I2C-over-AUX adapter.
297 	 *
298 	 * It's also used to specify the name of the I2C adapter. If set
299 	 * to %NULL, dev_name() of @dev will be used.
300 	 */
301 	const char *name;
302 
303 	/**
304 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
305 	 * communication
306 	 */
307 	struct i2c_adapter ddc;
308 
309 	/**
310 	 * @dev: pointer to struct device that is the parent for this
311 	 * AUX channel.
312 	 */
313 	struct device *dev;
314 
315 	/**
316 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
317 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
318 	 * called.
319 	 *
320 	 * It should be set to the &drm_device that will be using this AUX
321 	 * channel as early as possible. For many graphics drivers this should
322 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
323 	 * this field later so long as it's assigned before calling
324 	 * drm_dp_aux_register().
325 	 */
326 	struct drm_device *drm_dev;
327 
328 	/**
329 	 * @crtc: backpointer to the crtc that is currently using this
330 	 * AUX channel
331 	 */
332 	struct drm_crtc *crtc;
333 
334 	/**
335 	 * @hw_mutex: internal mutex used for locking transfers.
336 	 *
337 	 * Note that if the underlying hardware is shared among multiple
338 	 * channels, the driver needs to do additional locking to
339 	 * prevent concurrent access.
340 	 */
341 	struct mutex hw_mutex;
342 
343 	/**
344 	 * @crc_work: worker that captures CRCs for each frame
345 	 */
346 	struct work_struct crc_work;
347 
348 	/**
349 	 * @crc_count: counter of captured frame CRCs
350 	 */
351 	u8 crc_count;
352 
353 	/**
354 	 * @transfer: transfers a message representing a single AUX
355 	 * transaction.
356 	 *
357 	 * This is a hardware-specific implementation of how
358 	 * transactions are executed that the drivers must provide.
359 	 *
360 	 * A pointer to a &drm_dp_aux_msg structure describing the
361 	 * transaction is passed into this function. Upon success, the
362 	 * implementation should return the number of payload bytes that
363 	 * were transferred, or a negative error-code on failure.
364 	 *
365 	 * Helpers will propagate these errors, with the exception of
366 	 * the %-EBUSY error, which causes a transaction to be retried.
367 	 * On a short, helpers will return %-EPROTO to make it simpler
368 	 * to check for failure.
369 	 *
370 	 * The @transfer() function must only modify the reply field of
371 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
372 	 * helpers assume this is the case.
373 	 *
374 	 * Also note that this callback can be called no matter the
375 	 * state @dev is in and also no matter what state the panel is
376 	 * in. It's expected:
377 	 *
378 	 * - If the @dev providing the AUX bus is currently unpowered then
379 	 *   it will power itself up for the transfer.
380 	 *
381 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
382 	 *   state where it can respond (it's not powered or it's in a
383 	 *   low power state) then this function may return an error, but
384 	 *   not crash. It's up to the caller of this code to make sure that
385 	 *   the panel is powered on if getting an error back is not OK. If a
386 	 *   drm_panel driver is initiating a DP AUX transfer it may power
387 	 *   itself up however it wants. All other code should ensure that
388 	 *   the pre_enable() bridge chain (which eventually calls the
389 	 *   drm_panel prepare function) has powered the panel.
390 	 */
391 	ssize_t (*transfer)(struct drm_dp_aux *aux,
392 			    struct drm_dp_aux_msg *msg);
393 
394 	/**
395 	 * @wait_hpd_asserted: wait for HPD to be asserted
396 	 *
397 	 * This is mainly useful for eDP panels drivers to wait for an eDP
398 	 * panel to finish powering on. This is an optional function.
399 	 *
400 	 * This function will efficiently wait for the HPD signal to be
401 	 * asserted. The `wait_us` parameter that is passed in says that we
402 	 * know that the HPD signal is expected to be asserted within `wait_us`
403 	 * microseconds. This function could wait for longer than `wait_us` if
404 	 * the logic in the DP controller has a long debouncing time. The
405 	 * important thing is that if this function returns success that the
406 	 * DP controller is ready to send AUX transactions.
407 	 *
408 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
409 	 * expired and HPD wasn't asserted. This function should not print
410 	 * timeout errors to the log.
411 	 *
412 	 * The semantics of this function are designed to match the
413 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
414 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
415 	 *
416 	 * NOTE: this function specifically reports the state of the HPD pin
417 	 * that's associated with the DP AUX channel. This is different from
418 	 * the HPD concept in much of the rest of DRM which is more about
419 	 * physical presence of a display. For eDP, for instance, a display is
420 	 * assumed always present even if the HPD pin is deasserted.
421 	 */
422 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
423 
424 	/**
425 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
426 	 */
427 	unsigned i2c_nack_count;
428 	/**
429 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
430 	 */
431 	unsigned i2c_defer_count;
432 	/**
433 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
434 	 */
435 	struct drm_dp_aux_cec cec;
436 	/**
437 	 * @is_remote: Is this AUX CH actually using sideband messaging.
438 	 */
439 	bool is_remote;
440 };
441 
442 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
443 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
444 			 void *buffer, size_t size);
445 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
446 			  void *buffer, size_t size);
447 
448 /**
449  * drm_dp_dpcd_readb() - read a single byte from the DPCD
450  * @aux: DisplayPort AUX channel
451  * @offset: address of the register to read
452  * @valuep: location where the value of the register will be stored
453  *
454  * Returns the number of bytes transferred (1) on success, or a negative
455  * error code on failure.
456  */
457 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
458 					unsigned int offset, u8 *valuep)
459 {
460 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
461 }
462 
463 /**
464  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
465  * @aux: DisplayPort AUX channel
466  * @offset: address of the register to write
467  * @value: value to write to the register
468  *
469  * Returns the number of bytes transferred (1) on success, or a negative
470  * error code on failure.
471  */
472 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
473 					 unsigned int offset, u8 value)
474 {
475 	return drm_dp_dpcd_write(aux, offset, &value, 1);
476 }
477 
478 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
479 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
480 
481 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
482 				 u8 status[DP_LINK_STATUS_SIZE]);
483 
484 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
485 				     enum drm_dp_phy dp_phy,
486 				     u8 link_status[DP_LINK_STATUS_SIZE]);
487 
488 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
489 				    u8 real_edid_checksum);
490 
491 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
492 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
493 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
494 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
495 			       const u8 port_cap[4], u8 type);
496 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
497 			       const u8 port_cap[4],
498 			       const struct edid *edid);
499 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
500 				   const u8 port_cap[4]);
501 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
502 				     const u8 port_cap[4],
503 				     const struct edid *edid);
504 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
505 				     const u8 port_cap[4],
506 				     const struct edid *edid);
507 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
508 			      const u8 port_cap[4],
509 			      const struct edid *edid);
510 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
511 				       const u8 port_cap[4]);
512 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
513 					     const u8 port_cap[4]);
514 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
515 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
516 						const u8 port_cap[4]);
517 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
518 void drm_dp_downstream_debug(struct seq_file *m,
519 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
520 			     const u8 port_cap[4],
521 			     const struct edid *edid,
522 			     struct drm_dp_aux *aux);
523 enum drm_mode_subconnector
524 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
525 			 const u8 port_cap[4]);
526 void drm_dp_set_subconnector_property(struct drm_connector *connector,
527 				      enum drm_connector_status status,
528 				      const u8 *dpcd,
529 				      const u8 port_cap[4]);
530 
531 struct drm_dp_desc;
532 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
533 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
534 				const struct drm_dp_desc *desc);
535 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
536 
537 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
538 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
539 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
540 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
541 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
542 			       enum drm_dp_phy dp_phy,
543 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
544 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
545 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
546 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
547 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
548 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
549 
550 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
551 void drm_dp_aux_init(struct drm_dp_aux *aux);
552 int drm_dp_aux_register(struct drm_dp_aux *aux);
553 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
554 
555 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
556 int drm_dp_stop_crc(struct drm_dp_aux *aux);
557 
558 struct drm_dp_dpcd_ident {
559 	u8 oui[3];
560 	u8 device_id[6];
561 	u8 hw_rev;
562 	u8 sw_major_rev;
563 	u8 sw_minor_rev;
564 } __packed;
565 
566 /**
567  * struct drm_dp_desc - DP branch/sink device descriptor
568  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
569  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
570  */
571 struct drm_dp_desc {
572 	struct drm_dp_dpcd_ident ident;
573 	u32 quirks;
574 };
575 
576 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
577 		     bool is_branch);
578 
579 /**
580  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
581  *
582  * Display Port sink and branch devices in the wild have a variety of bugs, try
583  * to collect them here. The quirks are shared, but it's up to the drivers to
584  * implement workarounds for them.
585  */
586 enum drm_dp_quirk {
587 	/**
588 	 * @DP_DPCD_QUIRK_CONSTANT_N:
589 	 *
590 	 * The device requires main link attributes Mvid and Nvid to be limited
591 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
592 	 */
593 	DP_DPCD_QUIRK_CONSTANT_N,
594 	/**
595 	 * @DP_DPCD_QUIRK_NO_PSR:
596 	 *
597 	 * The device does not support PSR even if reports that it supports or
598 	 * driver still need to implement proper handling for such device.
599 	 */
600 	DP_DPCD_QUIRK_NO_PSR,
601 	/**
602 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
603 	 *
604 	 * The device does not set SINK_COUNT to a non-zero value.
605 	 * The driver should ignore SINK_COUNT during detection. Note that
606 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
607 	 */
608 	DP_DPCD_QUIRK_NO_SINK_COUNT,
609 	/**
610 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
611 	 *
612 	 * The device supports MST DSC despite not supporting Virtual DPCD.
613 	 * The DSC caps can be read from the physical aux instead.
614 	 */
615 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
616 	/**
617 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
618 	 *
619 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
620 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
621 	 */
622 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
623 };
624 
625 /**
626  * drm_dp_has_quirk() - does the DP device have a specific quirk
627  * @desc: Device descriptor filled by drm_dp_read_desc()
628  * @quirk: Quirk to query for
629  *
630  * Return true if DP device identified by @desc has @quirk.
631  */
632 static inline bool
633 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
634 {
635 	return desc->quirks & BIT(quirk);
636 }
637 
638 /**
639  * struct drm_edp_backlight_info - Probed eDP backlight info struct
640  * @pwmgen_bit_count: The pwmgen bit count
641  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
642  * @max: The maximum backlight level that may be set
643  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
644  * @aux_enable: Does the panel support the AUX enable cap?
645  * @aux_set: Does the panel support setting the brightness through AUX?
646  *
647  * This structure contains various data about an eDP backlight, which can be populated by using
648  * drm_edp_backlight_init().
649  */
650 struct drm_edp_backlight_info {
651 	u8 pwmgen_bit_count;
652 	u8 pwm_freq_pre_divider;
653 	u16 max;
654 
655 	bool lsb_reg_used : 1;
656 	bool aux_enable : 1;
657 	bool aux_set : 1;
658 };
659 
660 int
661 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
662 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
663 		       u16 *current_level, u8 *current_mode);
664 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
665 				u16 level);
666 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
667 			     u16 level);
668 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
669 
670 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
671 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
672 
673 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
674 
675 #else
676 
677 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
678 					     struct drm_dp_aux *aux)
679 {
680 	return 0;
681 }
682 
683 #endif
684 
685 #ifdef CONFIG_DRM_DP_CEC
686 void drm_dp_cec_irq(struct drm_dp_aux *aux);
687 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
688 				   struct drm_connector *connector);
689 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
690 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
691 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
692 #else
693 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
694 {
695 }
696 
697 static inline void
698 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
699 			      struct drm_connector *connector)
700 {
701 }
702 
703 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
704 {
705 }
706 
707 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
708 				       const struct edid *edid)
709 {
710 }
711 
712 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
713 {
714 }
715 
716 #endif
717 
718 /**
719  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
720  * @link_rate: Requested Link rate from DPCD 0x219
721  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
722  * @phy_pattern: DP Phy test pattern from DPCD 0x248
723  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
724  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
725  * @enhanced_frame_cap: flag for enhanced frame capability.
726  */
727 struct drm_dp_phy_test_params {
728 	int link_rate;
729 	u8 num_lanes;
730 	u8 phy_pattern;
731 	u8 hbr2_reset[2];
732 	u8 custom80[10];
733 	bool enhanced_frame_cap;
734 };
735 
736 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
737 				struct drm_dp_phy_test_params *data);
738 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
739 				struct drm_dp_phy_test_params *data, u8 dp_rev);
740 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
741 			       const u8 port_cap[4]);
742 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
743 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
744 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
745 				u8 frl_mode);
746 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
747 				u8 frl_type);
748 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
749 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
750 
751 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
752 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
753 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
754 					   struct drm_connector *connector);
755 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
756 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
757 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
758 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
759 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
760 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
761 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
762 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
763 					       const u8 port_cap[4], u8 color_spc);
764 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
765 
766 #endif /* _DRM_DP_HELPER_H_ */
767