xref: /linux/include/drm/display/drm_dp_helper.h (revision 55d0969c451159cff86949b38c39171cab962069)
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 /**
102  * struct drm_dp_as_sdp - drm DP Adaptive Sync SDP
103  *
104  * This structure represents a DP AS SDP of drm
105  * It is based on DP 2.1 spec [Table 2-126:  Adaptive-Sync SDP Header Bytes] and
106  * [Table 2-127: Adaptive-Sync SDP Payload for DB0 through DB8]
107  *
108  * @sdp_type: Secondary-data packet type
109  * @revision: Revision Number
110  * @length: Number of valid data bytes
111  * @vtotal: Minimum Vertical Vtotal
112  * @target_rr: Target Refresh
113  * @duration_incr_ms: Successive frame duration increase
114  * @duration_decr_ms: Successive frame duration decrease
115  * @target_rr_divider: Target refresh rate divider
116  * @mode: Adaptive Sync Operation Mode
117  */
118 struct drm_dp_as_sdp {
119 	unsigned char sdp_type;
120 	unsigned char revision;
121 	unsigned char length;
122 	int vtotal;
123 	int target_rr;
124 	int duration_incr_ms;
125 	int duration_decr_ms;
126 	bool target_rr_divider;
127 	enum operation_mode mode;
128 };
129 
130 void drm_dp_as_sdp_log(struct drm_printer *p,
131 		       const struct drm_dp_as_sdp *as_sdp);
132 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
133 
134 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
135 bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
136 
137 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
138 
139 static inline int
140 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
141 {
142 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
143 }
144 
145 static inline u8
146 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
147 {
148 	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
149 }
150 
151 static inline bool
152 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
153 {
154 	return dpcd[DP_DPCD_REV] >= 0x11 &&
155 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
156 }
157 
158 static inline bool
159 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
160 {
161 	return dpcd[DP_DPCD_REV] >= 0x11 &&
162 		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
163 }
164 
165 static inline bool
166 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
167 {
168 	return dpcd[DP_DPCD_REV] >= 0x12 &&
169 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
170 }
171 
172 static inline bool
173 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
174 {
175 	return dpcd[DP_DPCD_REV] >= 0x11 ||
176 		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
177 }
178 
179 static inline bool
180 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
181 {
182 	return dpcd[DP_DPCD_REV] >= 0x14 &&
183 		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
184 }
185 
186 static inline u8
187 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
188 {
189 	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
190 		DP_TRAINING_PATTERN_MASK;
191 }
192 
193 static inline bool
194 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
195 {
196 	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
197 }
198 
199 /* DP/eDP DSC support */
200 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
201 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
202 				   bool is_edp);
203 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
204 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
205 					 u8 dsc_bpc[3]);
206 
207 static inline bool
208 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
209 {
210 	return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
211 		DP_DSC_DECOMPRESSION_IS_SUPPORTED;
212 }
213 
214 static inline u16
215 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
216 {
217 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
218 		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
219 		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
220 }
221 
222 static inline u32
223 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
224 {
225 	/* Max Slicewidth = Number of Pixels * 320 */
226 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
227 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
228 }
229 
230 /**
231  * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format
232  * @dsc_dpcd : DSC-capability DPCDs of the sink
233  * @output_format: output_format which is to be checked
234  *
235  * Returns true if the sink supports DSC with the given output_format, false otherwise.
236  */
237 static inline bool
238 drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format)
239 {
240 	return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format;
241 }
242 
243 /* Forward Error Correction Support on DP 1.4 */
244 static inline bool
245 drm_dp_sink_supports_fec(const u8 fec_capable)
246 {
247 	return fec_capable & DP_FEC_CAPABLE;
248 }
249 
250 static inline bool
251 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
252 {
253 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
254 }
255 
256 static inline bool
257 drm_dp_128b132b_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
258 {
259 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_128B132B;
260 }
261 
262 static inline bool
263 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
264 {
265 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
266 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
267 }
268 
269 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
270 static inline bool
271 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
272 {
273 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
274 		DP_MSA_TIMING_PAR_IGNORED;
275 }
276 
277 /**
278  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
279  * @edp_dpcd: The DPCD to check
280  *
281  * Note that currently this function will return %false for panels which support various DPCD
282  * backlight features but which require the brightness be set through PWM, and don't support setting
283  * the brightness level via the DPCD.
284  *
285  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
286  * otherwise
287  */
288 static inline bool
289 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
290 {
291 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
292 }
293 
294 /**
295  * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR
296  * @link_rate: link rate in 10kbits/s units
297  *
298  * Determine if the provided link rate is an UHBR rate.
299  *
300  * Returns: %True if @link_rate is an UHBR rate.
301  */
302 static inline bool drm_dp_is_uhbr_rate(int link_rate)
303 {
304 	return link_rate >= 1000000;
305 }
306 
307 /*
308  * DisplayPort AUX channel
309  */
310 
311 /**
312  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
313  * @address: address of the (first) register to access
314  * @request: contains the type of transaction (see DP_AUX_* macros)
315  * @reply: upon completion, contains the reply type of the transaction
316  * @buffer: pointer to a transmission or reception buffer
317  * @size: size of @buffer
318  */
319 struct drm_dp_aux_msg {
320 	unsigned int address;
321 	u8 request;
322 	u8 reply;
323 	void *buffer;
324 	size_t size;
325 };
326 
327 struct cec_adapter;
328 struct drm_connector;
329 struct drm_edid;
330 
331 /**
332  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
333  * @lock: mutex protecting this struct
334  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
335  * @connector: the connector this CEC adapter is associated with
336  * @unregister_work: unregister the CEC adapter
337  */
338 struct drm_dp_aux_cec {
339 	struct mutex lock;
340 	struct cec_adapter *adap;
341 	struct drm_connector *connector;
342 	struct delayed_work unregister_work;
343 };
344 
345 /**
346  * struct drm_dp_aux - DisplayPort AUX channel
347  *
348  * An AUX channel can also be used to transport I2C messages to a sink. A
349  * typical application of that is to access an EDID that's present in the sink
350  * device. The @transfer() function can also be used to execute such
351  * transactions. The drm_dp_aux_register() function registers an I2C adapter
352  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
353  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
354  * transfers by default; if a partial response is received, the adapter will
355  * drop down to the size given by the partial response for this transaction
356  * only.
357  */
358 struct drm_dp_aux {
359 	/**
360 	 * @name: user-visible name of this AUX channel and the
361 	 * I2C-over-AUX adapter.
362 	 *
363 	 * It's also used to specify the name of the I2C adapter. If set
364 	 * to %NULL, dev_name() of @dev will be used.
365 	 */
366 	const char *name;
367 
368 	/**
369 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
370 	 * communication
371 	 */
372 	struct i2c_adapter ddc;
373 
374 	/**
375 	 * @dev: pointer to struct device that is the parent for this
376 	 * AUX channel.
377 	 */
378 	struct device *dev;
379 
380 	/**
381 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
382 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
383 	 * called.
384 	 *
385 	 * It should be set to the &drm_device that will be using this AUX
386 	 * channel as early as possible. For many graphics drivers this should
387 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
388 	 * this field later so long as it's assigned before calling
389 	 * drm_dp_aux_register().
390 	 */
391 	struct drm_device *drm_dev;
392 
393 	/**
394 	 * @crtc: backpointer to the crtc that is currently using this
395 	 * AUX channel
396 	 */
397 	struct drm_crtc *crtc;
398 
399 	/**
400 	 * @hw_mutex: internal mutex used for locking transfers.
401 	 *
402 	 * Note that if the underlying hardware is shared among multiple
403 	 * channels, the driver needs to do additional locking to
404 	 * prevent concurrent access.
405 	 */
406 	struct mutex hw_mutex;
407 
408 	/**
409 	 * @crc_work: worker that captures CRCs for each frame
410 	 */
411 	struct work_struct crc_work;
412 
413 	/**
414 	 * @crc_count: counter of captured frame CRCs
415 	 */
416 	u8 crc_count;
417 
418 	/**
419 	 * @transfer: transfers a message representing a single AUX
420 	 * transaction.
421 	 *
422 	 * This is a hardware-specific implementation of how
423 	 * transactions are executed that the drivers must provide.
424 	 *
425 	 * A pointer to a &drm_dp_aux_msg structure describing the
426 	 * transaction is passed into this function. Upon success, the
427 	 * implementation should return the number of payload bytes that
428 	 * were transferred, or a negative error-code on failure.
429 	 *
430 	 * Helpers will propagate these errors, with the exception of
431 	 * the %-EBUSY error, which causes a transaction to be retried.
432 	 * On a short, helpers will return %-EPROTO to make it simpler
433 	 * to check for failure.
434 	 *
435 	 * The @transfer() function must only modify the reply field of
436 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
437 	 * helpers assume this is the case.
438 	 *
439 	 * Also note that this callback can be called no matter the
440 	 * state @dev is in and also no matter what state the panel is
441 	 * in. It's expected:
442 	 *
443 	 * - If the @dev providing the AUX bus is currently unpowered then
444 	 *   it will power itself up for the transfer.
445 	 *
446 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
447 	 *   state where it can respond (it's not powered or it's in a
448 	 *   low power state) then this function may return an error, but
449 	 *   not crash. It's up to the caller of this code to make sure that
450 	 *   the panel is powered on if getting an error back is not OK. If a
451 	 *   drm_panel driver is initiating a DP AUX transfer it may power
452 	 *   itself up however it wants. All other code should ensure that
453 	 *   the pre_enable() bridge chain (which eventually calls the
454 	 *   drm_panel prepare function) has powered the panel.
455 	 */
456 	ssize_t (*transfer)(struct drm_dp_aux *aux,
457 			    struct drm_dp_aux_msg *msg);
458 
459 	/**
460 	 * @wait_hpd_asserted: wait for HPD to be asserted
461 	 *
462 	 * This is mainly useful for eDP panels drivers to wait for an eDP
463 	 * panel to finish powering on. It is optional for DP AUX controllers
464 	 * to implement this function. It is required for DP AUX endpoints
465 	 * (panel drivers) to call this function after powering up but before
466 	 * doing AUX transfers unless the DP AUX endpoint driver knows that
467 	 * we're not using the AUX controller's HPD. One example of the panel
468 	 * driver not needing to call this is if HPD is hooked up to a GPIO
469 	 * that the panel driver can read directly.
470 	 *
471 	 * If a DP AUX controller does not implement this function then it
472 	 * may still support eDP panels that use the AUX controller's built-in
473 	 * HPD signal by implementing a long wait for HPD in the transfer()
474 	 * callback, though this is deprecated.
475 	 *
476 	 * This function will efficiently wait for the HPD signal to be
477 	 * asserted. The `wait_us` parameter that is passed in says that we
478 	 * know that the HPD signal is expected to be asserted within `wait_us`
479 	 * microseconds. This function could wait for longer than `wait_us` if
480 	 * the logic in the DP controller has a long debouncing time. The
481 	 * important thing is that if this function returns success that the
482 	 * DP controller is ready to send AUX transactions.
483 	 *
484 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
485 	 * expired and HPD wasn't asserted. This function should not print
486 	 * timeout errors to the log.
487 	 *
488 	 * The semantics of this function are designed to match the
489 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
490 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
491 	 *
492 	 * NOTE: this function specifically reports the state of the HPD pin
493 	 * that's associated with the DP AUX channel. This is different from
494 	 * the HPD concept in much of the rest of DRM which is more about
495 	 * physical presence of a display. For eDP, for instance, a display is
496 	 * assumed always present even if the HPD pin is deasserted.
497 	 */
498 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
499 
500 	/**
501 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
502 	 */
503 	unsigned i2c_nack_count;
504 	/**
505 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
506 	 */
507 	unsigned i2c_defer_count;
508 	/**
509 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
510 	 */
511 	struct drm_dp_aux_cec cec;
512 	/**
513 	 * @is_remote: Is this AUX CH actually using sideband messaging.
514 	 */
515 	bool is_remote;
516 
517 	/**
518 	 * @powered_down: If true then the remote endpoint is powered down.
519 	 */
520 	bool powered_down;
521 };
522 
523 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
524 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
525 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
526 			 void *buffer, size_t size);
527 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
528 			  void *buffer, size_t size);
529 
530 /**
531  * drm_dp_dpcd_readb() - read a single byte from the DPCD
532  * @aux: DisplayPort AUX channel
533  * @offset: address of the register to read
534  * @valuep: location where the value of the register will be stored
535  *
536  * Returns the number of bytes transferred (1) on success, or a negative
537  * error code on failure.
538  */
539 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
540 					unsigned int offset, u8 *valuep)
541 {
542 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
543 }
544 
545 /**
546  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
547  * @aux: DisplayPort AUX channel
548  * @offset: address of the register to write
549  * @value: value to write to the register
550  *
551  * Returns the number of bytes transferred (1) on success, or a negative
552  * error code on failure.
553  */
554 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
555 					 unsigned int offset, u8 value)
556 {
557 	return drm_dp_dpcd_write(aux, offset, &value, 1);
558 }
559 
560 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
561 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
562 
563 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
564 				 u8 status[DP_LINK_STATUS_SIZE]);
565 
566 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
567 				     enum drm_dp_phy dp_phy,
568 				     u8 link_status[DP_LINK_STATUS_SIZE]);
569 
570 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
571 				    u8 real_edid_checksum);
572 
573 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
574 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
575 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
576 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
577 			       const u8 port_cap[4], u8 type);
578 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
579 			       const u8 port_cap[4],
580 			       const struct drm_edid *drm_edid);
581 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
582 				   const u8 port_cap[4]);
583 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
584 				     const u8 port_cap[4],
585 				     const struct drm_edid *drm_edid);
586 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
587 				     const u8 port_cap[4],
588 				     const struct drm_edid *drm_edid);
589 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
590 			      const u8 port_cap[4],
591 			      const struct drm_edid *drm_edid);
592 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
593 				       const u8 port_cap[4]);
594 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
595 					     const u8 port_cap[4]);
596 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
597 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
598 						const u8 port_cap[4]);
599 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
600 void drm_dp_downstream_debug(struct seq_file *m,
601 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
602 			     const u8 port_cap[4],
603 			     const struct drm_edid *drm_edid,
604 			     struct drm_dp_aux *aux);
605 enum drm_mode_subconnector
606 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
607 			 const u8 port_cap[4]);
608 void drm_dp_set_subconnector_property(struct drm_connector *connector,
609 				      enum drm_connector_status status,
610 				      const u8 *dpcd,
611 				      const u8 port_cap[4]);
612 
613 struct drm_dp_desc;
614 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
615 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
616 				const struct drm_dp_desc *desc);
617 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
618 
619 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
620 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
621 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
622 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
623 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
624 			       enum drm_dp_phy dp_phy,
625 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
626 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
627 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
628 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
629 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
630 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
631 
632 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
633 void drm_dp_aux_init(struct drm_dp_aux *aux);
634 int drm_dp_aux_register(struct drm_dp_aux *aux);
635 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
636 
637 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
638 int drm_dp_stop_crc(struct drm_dp_aux *aux);
639 
640 struct drm_dp_dpcd_ident {
641 	u8 oui[3];
642 	u8 device_id[6];
643 	u8 hw_rev;
644 	u8 sw_major_rev;
645 	u8 sw_minor_rev;
646 } __packed;
647 
648 /**
649  * struct drm_dp_desc - DP branch/sink device descriptor
650  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
651  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
652  */
653 struct drm_dp_desc {
654 	struct drm_dp_dpcd_ident ident;
655 	u32 quirks;
656 };
657 
658 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
659 		     bool is_branch);
660 
661 int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy);
662 
663 /**
664  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
665  *
666  * Display Port sink and branch devices in the wild have a variety of bugs, try
667  * to collect them here. The quirks are shared, but it's up to the drivers to
668  * implement workarounds for them.
669  */
670 enum drm_dp_quirk {
671 	/**
672 	 * @DP_DPCD_QUIRK_CONSTANT_N:
673 	 *
674 	 * The device requires main link attributes Mvid and Nvid to be limited
675 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
676 	 */
677 	DP_DPCD_QUIRK_CONSTANT_N,
678 	/**
679 	 * @DP_DPCD_QUIRK_NO_PSR:
680 	 *
681 	 * The device does not support PSR even if reports that it supports or
682 	 * driver still need to implement proper handling for such device.
683 	 */
684 	DP_DPCD_QUIRK_NO_PSR,
685 	/**
686 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
687 	 *
688 	 * The device does not set SINK_COUNT to a non-zero value.
689 	 * The driver should ignore SINK_COUNT during detection. Note that
690 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
691 	 */
692 	DP_DPCD_QUIRK_NO_SINK_COUNT,
693 	/**
694 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
695 	 *
696 	 * The device supports MST DSC despite not supporting Virtual DPCD.
697 	 * The DSC caps can be read from the physical aux instead.
698 	 */
699 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
700 	/**
701 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
702 	 *
703 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
704 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
705 	 */
706 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
707 	/**
708 	 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC:
709 	 *
710 	 * The device applies HBLANK expansion for some modes, but this
711 	 * requires enabling DSC.
712 	 */
713 	DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC,
714 };
715 
716 /**
717  * drm_dp_has_quirk() - does the DP device have a specific quirk
718  * @desc: Device descriptor filled by drm_dp_read_desc()
719  * @quirk: Quirk to query for
720  *
721  * Return true if DP device identified by @desc has @quirk.
722  */
723 static inline bool
724 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
725 {
726 	return desc->quirks & BIT(quirk);
727 }
728 
729 /**
730  * struct drm_edp_backlight_info - Probed eDP backlight info struct
731  * @pwmgen_bit_count: The pwmgen bit count
732  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
733  * @max: The maximum backlight level that may be set
734  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
735  * @aux_enable: Does the panel support the AUX enable cap?
736  * @aux_set: Does the panel support setting the brightness through AUX?
737  *
738  * This structure contains various data about an eDP backlight, which can be populated by using
739  * drm_edp_backlight_init().
740  */
741 struct drm_edp_backlight_info {
742 	u8 pwmgen_bit_count;
743 	u8 pwm_freq_pre_divider;
744 	u16 max;
745 
746 	bool lsb_reg_used : 1;
747 	bool aux_enable : 1;
748 	bool aux_set : 1;
749 };
750 
751 int
752 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
753 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
754 		       u16 *current_level, u8 *current_mode);
755 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
756 				u16 level);
757 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
758 			     u16 level);
759 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
760 
761 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
762 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
763 
764 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
765 
766 #else
767 
768 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
769 					     struct drm_dp_aux *aux)
770 {
771 	return 0;
772 }
773 
774 #endif
775 
776 #ifdef CONFIG_DRM_DISPLAY_DP_AUX_CEC
777 void drm_dp_cec_irq(struct drm_dp_aux *aux);
778 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
779 				   struct drm_connector *connector);
780 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
781 void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
782 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
783 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
784 #else
785 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
786 {
787 }
788 
789 static inline void
790 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
791 			      struct drm_connector *connector)
792 {
793 }
794 
795 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
796 {
797 }
798 
799 static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
800 				     u16 source_physical_address)
801 {
802 }
803 
804 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
805 				       const struct edid *edid)
806 {
807 }
808 
809 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
810 {
811 }
812 
813 #endif
814 
815 /**
816  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
817  * @link_rate: Requested Link rate from DPCD 0x219
818  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
819  * @phy_pattern: DP Phy test pattern from DPCD 0x248
820  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
821  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
822  * @enhanced_frame_cap: flag for enhanced frame capability.
823  */
824 struct drm_dp_phy_test_params {
825 	int link_rate;
826 	u8 num_lanes;
827 	u8 phy_pattern;
828 	u8 hbr2_reset[2];
829 	u8 custom80[10];
830 	bool enhanced_frame_cap;
831 };
832 
833 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
834 				struct drm_dp_phy_test_params *data);
835 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
836 				struct drm_dp_phy_test_params *data, u8 dp_rev);
837 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
838 			       const u8 port_cap[4]);
839 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
840 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
841 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
842 				u8 frl_mode);
843 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
844 				u8 frl_type);
845 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
846 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
847 
848 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
849 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
850 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
851 					   struct drm_connector *connector);
852 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
853 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
854 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
855 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
856 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
857 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
858 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
859 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
860 					       const u8 port_cap[4], u8 color_spc);
861 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
862 
863 #define DRM_DP_BW_OVERHEAD_MST		BIT(0)
864 #define DRM_DP_BW_OVERHEAD_UHBR		BIT(1)
865 #define DRM_DP_BW_OVERHEAD_SSC_REF_CLK	BIT(2)
866 #define DRM_DP_BW_OVERHEAD_FEC		BIT(3)
867 #define DRM_DP_BW_OVERHEAD_DSC		BIT(4)
868 
869 int drm_dp_bw_overhead(int lane_count, int hactive,
870 		       int dsc_slice_count,
871 		       int bpp_x16, unsigned long flags);
872 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
873 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
874 
875 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
876 
877 #endif /* _DRM_DP_HELPER_H_ */
878