xref: /linux/include/drm/display/drm_dp_helper.h (revision 39d3389331abd712461f50249722f7ed9d815068)
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 bool drm_dp_post_lt_adj_req_in_progress(const u8 link_status[DP_LINK_STATUS_SIZE]);
41 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
42 				     int lane);
43 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
44 					  int lane);
45 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
46 				   int lane);
47 
48 int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
49 				     enum drm_dp_phy dp_phy, bool uhbr);
50 int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
51 				 enum drm_dp_phy dp_phy, bool uhbr);
52 
53 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
54 					    const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
55 void drm_dp_lttpr_link_train_clock_recovery_delay(void);
56 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
57 					const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
58 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
59 					      const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
60 
61 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
62 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
63 					  int lane_count);
64 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
65 					int lane_count);
66 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
67 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
68 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
69 
70 u8 drm_dp_link_rate_to_bw_code(int link_rate);
71 int drm_dp_bw_code_to_link_rate(u8 link_bw);
72 
73 const char *drm_dp_phy_name(enum drm_dp_phy dp_phy);
74 
75 /**
76  * struct drm_dp_vsc_sdp - drm DP VSC SDP
77  *
78  * This structure represents a DP VSC SDP of drm
79  * It is based on DP 1.4 spec [Table 2-116: VSC SDP Header Bytes] and
80  * [Table 2-117: VSC SDP Payload for DB16 through DB18]
81  *
82  * @sdp_type: secondary-data packet type
83  * @revision: revision number
84  * @length: number of valid data bytes
85  * @pixelformat: pixel encoding format
86  * @colorimetry: colorimetry format
87  * @bpc: bit per color
88  * @dynamic_range: dynamic range information
89  * @content_type: CTA-861-G defines content types and expected processing by a sink device
90  */
91 struct drm_dp_vsc_sdp {
92 	unsigned char sdp_type;
93 	unsigned char revision;
94 	unsigned char length;
95 	enum dp_pixelformat pixelformat;
96 	enum dp_colorimetry colorimetry;
97 	int bpc;
98 	enum dp_dynamic_range dynamic_range;
99 	enum dp_content_type content_type;
100 };
101 
102 /**
103  * struct drm_dp_as_sdp - drm DP Adaptive Sync SDP
104  *
105  * This structure represents a DP AS SDP of drm
106  * It is based on DP 2.1 spec [Table 2-126:  Adaptive-Sync SDP Header Bytes] and
107  * [Table 2-127: Adaptive-Sync SDP Payload for DB0 through DB8]
108  *
109  * @sdp_type: Secondary-data packet type
110  * @revision: Revision Number
111  * @length: Number of valid data bytes
112  * @vtotal: Minimum Vertical Vtotal
113  * @target_rr: Target Refresh
114  * @duration_incr_ms: Successive frame duration increase
115  * @duration_decr_ms: Successive frame duration decrease
116  * @target_rr_divider: Target refresh rate divider
117  * @mode: Adaptive Sync Operation Mode
118  */
119 struct drm_dp_as_sdp {
120 	unsigned char sdp_type;
121 	unsigned char revision;
122 	unsigned char length;
123 	int vtotal;
124 	int target_rr;
125 	int duration_incr_ms;
126 	int duration_decr_ms;
127 	bool target_rr_divider;
128 	enum operation_mode mode;
129 };
130 
131 void drm_dp_as_sdp_log(struct drm_printer *p,
132 		       const struct drm_dp_as_sdp *as_sdp);
133 void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
134 
135 bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
136 bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
137 
138 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
139 
140 static inline int
drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])141 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
142 {
143 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
144 }
145 
146 static inline u8
drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])147 drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
148 {
149 	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
150 }
151 
152 static inline bool
drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])153 drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
154 {
155 	return dpcd[DP_DPCD_REV] >= 0x11 &&
156 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
157 }
158 
159 static inline bool
drm_dp_post_lt_adj_req_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])160 drm_dp_post_lt_adj_req_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
161 {
162 	return dpcd[DP_DPCD_REV] >= 0x13 &&
163 		(dpcd[DP_MAX_LANE_COUNT] & DP_POST_LT_ADJ_REQ_SUPPORTED);
164 }
165 
166 static inline bool
drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])167 drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
168 {
169 	return dpcd[DP_DPCD_REV] >= 0x11 &&
170 		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
171 }
172 
173 static inline bool
drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])174 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
175 {
176 	return dpcd[DP_DPCD_REV] >= 0x12 &&
177 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
178 }
179 
180 static inline bool
drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])181 drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
182 {
183 	return dpcd[DP_DPCD_REV] >= 0x11 ||
184 		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
185 }
186 
187 static inline bool
drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])188 drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
189 {
190 	return dpcd[DP_DPCD_REV] >= 0x14 &&
191 		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
192 }
193 
194 static inline u8
drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])195 drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
196 {
197 	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
198 		DP_TRAINING_PATTERN_MASK;
199 }
200 
201 static inline bool
drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])202 drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
203 {
204 	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
205 }
206 
207 /* DP/eDP DSC support */
208 u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
209 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
210 				   bool is_edp);
211 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
212 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
213 					 u8 dsc_bpc[3]);
214 int drm_dp_dsc_sink_max_slice_throughput(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
215 					 int peak_pixel_rate, bool is_rgb_yuv444);
216 int drm_dp_dsc_branch_max_overall_throughput(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE],
217 					     bool is_rgb_yuv444);
218 int drm_dp_dsc_branch_max_line_width(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE]);
219 
220 static inline bool
drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])221 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
222 {
223 	return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
224 		DP_DSC_DECOMPRESSION_IS_SUPPORTED;
225 }
226 
227 static inline u16
drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])228 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
229 {
230 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
231 		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
232 		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
233 }
234 
235 static inline u32
drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])236 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
237 {
238 	/* Max Slicewidth = Number of Pixels * 320 */
239 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
240 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
241 }
242 
243 /**
244  * drm_dp_dsc_sink_supports_format() - check if sink supports DSC with given output format
245  * @dsc_dpcd : DSC-capability DPCDs of the sink
246  * @output_format: output_format which is to be checked
247  *
248  * Returns true if the sink supports DSC with the given output_format, false otherwise.
249  */
250 static inline bool
drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],u8 output_format)251 drm_dp_dsc_sink_supports_format(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], u8 output_format)
252 {
253 	return dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] & output_format;
254 }
255 
256 /* Forward Error Correction Support on DP 1.4 */
257 static inline bool
drm_dp_sink_supports_fec(const u8 fec_capable)258 drm_dp_sink_supports_fec(const u8 fec_capable)
259 {
260 	return fec_capable & DP_FEC_CAPABLE;
261 }
262 
263 static inline bool
drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])264 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
265 {
266 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
267 }
268 
269 static inline bool
drm_dp_128b132b_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])270 drm_dp_128b132b_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
271 {
272 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_128B132B;
273 }
274 
275 static inline bool
drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])276 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
277 {
278 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
279 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
280 }
281 
282 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
283 static inline bool
drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])284 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
285 {
286 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
287 		DP_MSA_TIMING_PAR_IGNORED;
288 }
289 
290 /**
291  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
292  * @edp_dpcd: The DPCD to check
293  *
294  * Note that currently this function will return %false for panels which support various DPCD
295  * backlight features but which require the brightness be set through PWM, and don't support setting
296  * the brightness level via the DPCD.
297  *
298  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
299  * otherwise
300  */
301 static inline bool
drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])302 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
303 {
304 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
305 }
306 
307 /**
308  * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR
309  * @link_rate: link rate in 10kbits/s units
310  *
311  * Determine if the provided link rate is an UHBR rate.
312  *
313  * Returns: %True if @link_rate is an UHBR rate.
314  */
drm_dp_is_uhbr_rate(int link_rate)315 static inline bool drm_dp_is_uhbr_rate(int link_rate)
316 {
317 	return link_rate >= 1000000;
318 }
319 
320 /*
321  * DisplayPort AUX channel
322  */
323 
324 /**
325  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
326  * @address: address of the (first) register to access
327  * @request: contains the type of transaction (see DP_AUX_* macros)
328  * @reply: upon completion, contains the reply type of the transaction
329  * @buffer: pointer to a transmission or reception buffer
330  * @size: size of @buffer
331  */
332 struct drm_dp_aux_msg {
333 	unsigned int address;
334 	u8 request;
335 	u8 reply;
336 	void *buffer;
337 	size_t size;
338 };
339 
340 struct cec_adapter;
341 struct drm_connector;
342 struct drm_edid;
343 
344 /**
345  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
346  * @lock: mutex protecting this struct
347  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
348  * @connector: the connector this CEC adapter is associated with
349  * @unregister_work: unregister the CEC adapter
350  */
351 struct drm_dp_aux_cec {
352 	struct mutex lock;
353 	struct cec_adapter *adap;
354 	struct drm_connector *connector;
355 	struct delayed_work unregister_work;
356 };
357 
358 /**
359  * struct drm_dp_aux - DisplayPort AUX channel
360  *
361  * An AUX channel can also be used to transport I2C messages to a sink. A
362  * typical application of that is to access an EDID that's present in the sink
363  * device. The @transfer() function can also be used to execute such
364  * transactions. The drm_dp_aux_register() function registers an I2C adapter
365  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
366  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
367  * transfers by default; if a partial response is received, the adapter will
368  * drop down to the size given by the partial response for this transaction
369  * only.
370  */
371 struct drm_dp_aux {
372 	/**
373 	 * @name: user-visible name of this AUX channel and the
374 	 * I2C-over-AUX adapter.
375 	 *
376 	 * It's also used to specify the name of the I2C adapter. If set
377 	 * to %NULL, dev_name() of @dev will be used.
378 	 */
379 	const char *name;
380 
381 	/**
382 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
383 	 * communication
384 	 */
385 	struct i2c_adapter ddc;
386 
387 	/**
388 	 * @dev: pointer to struct device that is the parent for this
389 	 * AUX channel.
390 	 */
391 	struct device *dev;
392 
393 	/**
394 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
395 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
396 	 * called.
397 	 *
398 	 * It should be set to the &drm_device that will be using this AUX
399 	 * channel as early as possible. For many graphics drivers this should
400 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
401 	 * this field later so long as it's assigned before calling
402 	 * drm_dp_aux_register().
403 	 */
404 	struct drm_device *drm_dev;
405 
406 	/**
407 	 * @crtc: backpointer to the crtc that is currently using this
408 	 * AUX channel
409 	 */
410 	struct drm_crtc *crtc;
411 
412 	/**
413 	 * @hw_mutex: internal mutex used for locking transfers.
414 	 *
415 	 * Note that if the underlying hardware is shared among multiple
416 	 * channels, the driver needs to do additional locking to
417 	 * prevent concurrent access.
418 	 */
419 	struct mutex hw_mutex;
420 
421 	/**
422 	 * @crc_work: worker that captures CRCs for each frame
423 	 */
424 	struct work_struct crc_work;
425 
426 	/**
427 	 * @crc_count: counter of captured frame CRCs
428 	 */
429 	u8 crc_count;
430 
431 	/**
432 	 * @transfer: transfers a message representing a single AUX
433 	 * transaction.
434 	 *
435 	 * This is a hardware-specific implementation of how
436 	 * transactions are executed that the drivers must provide.
437 	 *
438 	 * A pointer to a &drm_dp_aux_msg structure describing the
439 	 * transaction is passed into this function. Upon success, the
440 	 * implementation should return the number of payload bytes that
441 	 * were transferred, or a negative error-code on failure.
442 	 *
443 	 * Helpers will propagate these errors, with the exception of
444 	 * the %-EBUSY error, which causes a transaction to be retried.
445 	 * On a short, helpers will return %-EPROTO to make it simpler
446 	 * to check for failure.
447 	 *
448 	 * The @transfer() function must only modify the reply field of
449 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
450 	 * helpers assume this is the case.
451 	 *
452 	 * Also note that this callback can be called no matter the
453 	 * state @dev is in and also no matter what state the panel is
454 	 * in. It's expected:
455 	 *
456 	 * - If the @dev providing the AUX bus is currently unpowered then
457 	 *   it will power itself up for the transfer.
458 	 *
459 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
460 	 *   state where it can respond (it's not powered or it's in a
461 	 *   low power state) then this function may return an error, but
462 	 *   not crash. It's up to the caller of this code to make sure that
463 	 *   the panel is powered on if getting an error back is not OK. If a
464 	 *   drm_panel driver is initiating a DP AUX transfer it may power
465 	 *   itself up however it wants. All other code should ensure that
466 	 *   the pre_enable() bridge chain (which eventually calls the
467 	 *   drm_panel prepare function) has powered the panel.
468 	 */
469 	ssize_t (*transfer)(struct drm_dp_aux *aux,
470 			    struct drm_dp_aux_msg *msg);
471 
472 	/**
473 	 * @wait_hpd_asserted: wait for HPD to be asserted
474 	 *
475 	 * This is mainly useful for eDP panels drivers to wait for an eDP
476 	 * panel to finish powering on. It is optional for DP AUX controllers
477 	 * to implement this function. It is required for DP AUX endpoints
478 	 * (panel drivers) to call this function after powering up but before
479 	 * doing AUX transfers unless the DP AUX endpoint driver knows that
480 	 * we're not using the AUX controller's HPD. One example of the panel
481 	 * driver not needing to call this is if HPD is hooked up to a GPIO
482 	 * that the panel driver can read directly.
483 	 *
484 	 * If a DP AUX controller does not implement this function then it
485 	 * may still support eDP panels that use the AUX controller's built-in
486 	 * HPD signal by implementing a long wait for HPD in the transfer()
487 	 * callback, though this is deprecated.
488 	 *
489 	 * This function will efficiently wait for the HPD signal to be
490 	 * asserted. The `wait_us` parameter that is passed in says that we
491 	 * know that the HPD signal is expected to be asserted within `wait_us`
492 	 * microseconds. This function could wait for longer than `wait_us` if
493 	 * the logic in the DP controller has a long debouncing time. The
494 	 * important thing is that if this function returns success that the
495 	 * DP controller is ready to send AUX transactions.
496 	 *
497 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
498 	 * expired and HPD wasn't asserted. This function should not print
499 	 * timeout errors to the log.
500 	 *
501 	 * The semantics of this function are designed to match the
502 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
503 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
504 	 *
505 	 * NOTE: this function specifically reports the state of the HPD pin
506 	 * that's associated with the DP AUX channel. This is different from
507 	 * the HPD concept in much of the rest of DRM which is more about
508 	 * physical presence of a display. For eDP, for instance, a display is
509 	 * assumed always present even if the HPD pin is deasserted.
510 	 */
511 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
512 
513 	/**
514 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
515 	 */
516 	unsigned i2c_nack_count;
517 	/**
518 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
519 	 */
520 	unsigned i2c_defer_count;
521 	/**
522 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
523 	 */
524 	struct drm_dp_aux_cec cec;
525 	/**
526 	 * @is_remote: Is this AUX CH actually using sideband messaging.
527 	 */
528 	bool is_remote;
529 
530 	/**
531 	 * @powered_down: If true then the remote endpoint is powered down.
532 	 */
533 	bool powered_down;
534 
535 	/**
536 	 * @no_zero_sized: If the hw can't use zero sized transfers (NVIDIA)
537 	 */
538 	bool no_zero_sized;
539 
540 	/**
541 	 * @dpcd_probe_disabled: If probing before a DPCD access is disabled.
542 	 */
543 	bool dpcd_probe_disabled;
544 };
545 
546 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
547 void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
548 void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable);
549 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
550 			 void *buffer, size_t size);
551 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
552 			  void *buffer, size_t size);
553 
554 /**
555  * drm_dp_dpcd_readb() - read a single byte from the DPCD
556  * @aux: DisplayPort AUX channel
557  * @offset: address of the register to read
558  * @valuep: location where the value of the register will be stored
559  *
560  * Returns the number of bytes transferred (1) on success, or a negative
561  * error code on failure. In most of the cases you should be using
562  * drm_dp_dpcd_read_byte() instead.
563  */
drm_dp_dpcd_readb(struct drm_dp_aux * aux,unsigned int offset,u8 * valuep)564 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
565 					unsigned int offset, u8 *valuep)
566 {
567 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
568 }
569 
570 /**
571  * drm_dp_dpcd_read_data() - read a series of bytes from the DPCD
572  * @aux: DisplayPort AUX channel (SST or MST)
573  * @offset: address of the (first) register to read
574  * @buffer: buffer to store the register values
575  * @size: number of bytes in @buffer
576  *
577  * Returns zero (0) on success, or a negative error
578  * code on failure. -EIO is returned if the request was NAKed by the sink or
579  * if the retry count was exceeded. If not all bytes were transferred, this
580  * function returns -EPROTO. Errors from the underlying AUX channel transfer
581  * function, with the exception of -EBUSY (which causes the transaction to
582  * be retried), are propagated to the caller.
583  */
drm_dp_dpcd_read_data(struct drm_dp_aux * aux,unsigned int offset,void * buffer,size_t size)584 static inline int drm_dp_dpcd_read_data(struct drm_dp_aux *aux,
585 					unsigned int offset,
586 					void *buffer, size_t size)
587 {
588 	int ret;
589 	size_t i;
590 	u8 *buf = buffer;
591 
592 	ret = drm_dp_dpcd_read(aux, offset, buffer, size);
593 	if (ret >= 0) {
594 		if (ret < size)
595 			return -EPROTO;
596 		return 0;
597 	}
598 
599 	/*
600 	 * Workaround for USB-C hubs/adapters with buggy firmware that fail
601 	 * multi-byte AUX reads but work with single-byte reads.
602 	 * Known affected devices:
603 	 * - Lenovo USB-C to VGA adapter (VIA VL817, idVendor=17ef, idProduct=7217)
604 	 * - Dell DA310 USB-C hub (idVendor=413c, idProduct=c010)
605 	 * Attempt byte-by-byte reading as a fallback.
606 	 */
607 	for (i = 0; i < size; i++) {
608 		ret = drm_dp_dpcd_readb(aux, offset + i, &buf[i]);
609 		if (ret < 0)
610 			return ret;
611 	}
612 
613 	return 0;
614 }
615 
616 /**
617  * drm_dp_dpcd_write_data() - write a series of bytes to the DPCD
618  * @aux: DisplayPort AUX channel (SST or MST)
619  * @offset: address of the (first) register to write
620  * @buffer: buffer containing the values to write
621  * @size: number of bytes in @buffer
622  *
623  * Returns zero (0) on success, or a negative error
624  * code on failure. -EIO is returned if the request was NAKed by the sink or
625  * if the retry count was exceeded. If not all bytes were transferred, this
626  * function returns -EPROTO. Errors from the underlying AUX channel transfer
627  * function, with the exception of -EBUSY (which causes the transaction to
628  * be retried), are propagated to the caller.
629  */
drm_dp_dpcd_write_data(struct drm_dp_aux * aux,unsigned int offset,void * buffer,size_t size)630 static inline int drm_dp_dpcd_write_data(struct drm_dp_aux *aux,
631 					 unsigned int offset,
632 					 void *buffer, size_t size)
633 {
634 	int ret;
635 
636 	ret = drm_dp_dpcd_write(aux, offset, buffer, size);
637 	if (ret < 0)
638 		return ret;
639 	if (ret < size)
640 		return -EPROTO;
641 
642 	return 0;
643 }
644 
645 /**
646  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
647  * @aux: DisplayPort AUX channel
648  * @offset: address of the register to write
649  * @value: value to write to the register
650  *
651  * Returns the number of bytes transferred (1) on success, or a negative
652  * error code on failure. In most of the cases you should be using
653  * drm_dp_dpcd_write_byte() instead.
654  */
drm_dp_dpcd_writeb(struct drm_dp_aux * aux,unsigned int offset,u8 value)655 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
656 					 unsigned int offset, u8 value)
657 {
658 	return drm_dp_dpcd_write(aux, offset, &value, 1);
659 }
660 
661 /**
662  * drm_dp_dpcd_read_byte() - read a single byte from the DPCD
663  * @aux: DisplayPort AUX channel
664  * @offset: address of the register to read
665  * @valuep: location where the value of the register will be stored
666  *
667  * Returns zero (0) on success, or a negative error code on failure.
668  */
drm_dp_dpcd_read_byte(struct drm_dp_aux * aux,unsigned int offset,u8 * valuep)669 static inline int drm_dp_dpcd_read_byte(struct drm_dp_aux *aux,
670 					unsigned int offset, u8 *valuep)
671 {
672 	return drm_dp_dpcd_read_data(aux, offset, valuep, 1);
673 }
674 
675 /**
676  * drm_dp_dpcd_write_byte() - write a single byte to the DPCD
677  * @aux: DisplayPort AUX channel
678  * @offset: address of the register to write
679  * @value: value to write to the register
680  *
681  * Returns zero (0) on success, or a negative error code on failure.
682  */
drm_dp_dpcd_write_byte(struct drm_dp_aux * aux,unsigned int offset,u8 value)683 static inline int drm_dp_dpcd_write_byte(struct drm_dp_aux *aux,
684 					 unsigned int offset, u8 value)
685 {
686 	return drm_dp_dpcd_write_data(aux, offset, &value, 1);
687 }
688 
689 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
690 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
691 
692 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
693 				 u8 status[DP_LINK_STATUS_SIZE]);
694 
695 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
696 				     enum drm_dp_phy dp_phy,
697 				     u8 link_status[DP_LINK_STATUS_SIZE]);
698 int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision);
699 int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision);
700 
701 int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux,
702 			      int vcpid, u8 start_time_slot, u8 time_slot_count);
703 int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux);
704 int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms);
705 
706 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
707 				    u8 real_edid_checksum);
708 
709 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
710 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
711 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
712 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
713 			       const u8 port_cap[4], u8 type);
714 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
715 			       const u8 port_cap[4],
716 			       const struct drm_edid *drm_edid);
717 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
718 				   const u8 port_cap[4]);
719 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
720 				     const u8 port_cap[4],
721 				     const struct drm_edid *drm_edid);
722 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
723 				     const u8 port_cap[4],
724 				     const struct drm_edid *drm_edid);
725 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
726 			      const u8 port_cap[4],
727 			      const struct drm_edid *drm_edid);
728 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
729 				       const u8 port_cap[4]);
730 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
731 					     const u8 port_cap[4]);
732 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
733 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
734 						const u8 port_cap[4]);
735 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
736 void drm_dp_downstream_debug(struct seq_file *m,
737 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
738 			     const u8 port_cap[4],
739 			     const struct drm_edid *drm_edid,
740 			     struct drm_dp_aux *aux);
741 enum drm_mode_subconnector
742 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
743 			 const u8 port_cap[4]);
744 void drm_dp_set_subconnector_property(struct drm_connector *connector,
745 				      enum drm_connector_status status,
746 				      const u8 *dpcd,
747 				      const u8 port_cap[4]);
748 
749 struct drm_dp_desc;
750 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
751 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
752 				const struct drm_dp_desc *desc);
753 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
754 
755 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
756 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
757 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
758 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
759 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
760 			       enum drm_dp_phy dp_phy,
761 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
762 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
763 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
764 int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable);
765 int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count);
766 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
767 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
768 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
769 void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode);
770 
771 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
772 void drm_dp_aux_init(struct drm_dp_aux *aux);
773 int drm_dp_aux_register(struct drm_dp_aux *aux);
774 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
775 
776 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
777 int drm_dp_stop_crc(struct drm_dp_aux *aux);
778 
779 struct drm_dp_dpcd_ident {
780 	u8 oui[3];
781 	u8 device_id[6];
782 	u8 hw_rev;
783 	u8 sw_major_rev;
784 	u8 sw_minor_rev;
785 } __packed;
786 
787 /**
788  * struct drm_dp_desc - DP branch/sink device descriptor
789  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
790  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
791  */
792 struct drm_dp_desc {
793 	struct drm_dp_dpcd_ident ident;
794 	u32 quirks;
795 };
796 
797 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
798 		     bool is_branch);
799 
800 int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy);
801 
802 /**
803  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
804  *
805  * Display Port sink and branch devices in the wild have a variety of bugs, try
806  * to collect them here. The quirks are shared, but it's up to the drivers to
807  * implement workarounds for them.
808  */
809 enum drm_dp_quirk {
810 	/**
811 	 * @DP_DPCD_QUIRK_CONSTANT_N:
812 	 *
813 	 * The device requires main link attributes Mvid and Nvid to be limited
814 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
815 	 */
816 	DP_DPCD_QUIRK_CONSTANT_N,
817 	/**
818 	 * @DP_DPCD_QUIRK_NO_PSR:
819 	 *
820 	 * The device does not support PSR even if reports that it supports or
821 	 * driver still need to implement proper handling for such device.
822 	 */
823 	DP_DPCD_QUIRK_NO_PSR,
824 	/**
825 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
826 	 *
827 	 * The device does not set SINK_COUNT to a non-zero value.
828 	 * The driver should ignore SINK_COUNT during detection. Note that
829 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
830 	 */
831 	DP_DPCD_QUIRK_NO_SINK_COUNT,
832 	/**
833 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
834 	 *
835 	 * The device supports MST DSC despite not supporting Virtual DPCD.
836 	 * The DSC caps can be read from the physical aux instead.
837 	 */
838 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
839 	/**
840 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
841 	 *
842 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
843 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
844 	 */
845 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
846 	/**
847 	 * @DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC:
848 	 *
849 	 * The device applies HBLANK expansion for some modes, but this
850 	 * requires enabling DSC.
851 	 */
852 	DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC,
853 	/**
854 	 * @DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT:
855 	 *
856 	 * The device doesn't support DSC decompression at the maximum DSC
857 	 * pixel throughput and compressed bpp it indicates via its DPCD DSC
858 	 * capabilities. The compressed bpp must be limited above a device
859 	 * specific DSC pixel throughput.
860 	 */
861 	DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT,
862 };
863 
864 /**
865  * drm_dp_has_quirk() - does the DP device have a specific quirk
866  * @desc: Device descriptor filled by drm_dp_read_desc()
867  * @quirk: Quirk to query for
868  *
869  * Return true if DP device identified by @desc has @quirk.
870  */
871 static inline bool
drm_dp_has_quirk(const struct drm_dp_desc * desc,enum drm_dp_quirk quirk)872 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
873 {
874 	return desc->quirks & BIT(quirk);
875 }
876 
877 /**
878  * struct drm_edp_backlight_info - Probed eDP backlight info struct
879  * @pwmgen_bit_count: The pwmgen bit count
880  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
881  * @max: The maximum backlight level that may be set
882  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
883  * @aux_enable: Does the panel support the AUX enable cap?
884  * @aux_set: Does the panel support setting the brightness through AUX?
885  * @luminance_set: Does the panel support setting the brightness through AUX using luminance values?
886  *
887  * This structure contains various data about an eDP backlight, which can be populated by using
888  * drm_edp_backlight_init().
889  */
890 struct drm_edp_backlight_info {
891 	u8 pwmgen_bit_count;
892 	u8 pwm_freq_pre_divider;
893 	u32 max;
894 
895 	bool lsb_reg_used : 1;
896 	bool aux_enable : 1;
897 	bool aux_set : 1;
898 	bool luminance_set : 1;
899 };
900 
901 int
902 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
903 		       u32 max_luminance,
904 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
905 		       u32 *current_level, u8 *current_mode, bool need_luminance);
906 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
907 				u32 level);
908 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
909 			     u32 level);
910 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
911 
912 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
913 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
914 
915 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
916 
917 #else
918 
drm_panel_dp_aux_backlight(struct drm_panel * panel,struct drm_dp_aux * aux)919 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
920 					     struct drm_dp_aux *aux)
921 {
922 	return 0;
923 }
924 
925 #endif
926 
927 #ifdef CONFIG_DRM_DISPLAY_DP_AUX_CEC
928 void drm_dp_cec_irq(struct drm_dp_aux *aux);
929 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
930 				   struct drm_connector *connector);
931 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
932 void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
933 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
934 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
935 #else
drm_dp_cec_irq(struct drm_dp_aux * aux)936 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
937 {
938 }
939 
940 static inline void
drm_dp_cec_register_connector(struct drm_dp_aux * aux,struct drm_connector * connector)941 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
942 			      struct drm_connector *connector)
943 {
944 }
945 
drm_dp_cec_unregister_connector(struct drm_dp_aux * aux)946 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
947 {
948 }
949 
drm_dp_cec_attach(struct drm_dp_aux * aux,u16 source_physical_address)950 static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
951 				     u16 source_physical_address)
952 {
953 }
954 
drm_dp_cec_set_edid(struct drm_dp_aux * aux,const struct edid * edid)955 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
956 				       const struct edid *edid)
957 {
958 }
959 
drm_dp_cec_unset_edid(struct drm_dp_aux * aux)960 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
961 {
962 }
963 
964 #endif
965 
966 /**
967  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
968  * @link_rate: Requested Link rate from DPCD 0x219
969  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
970  * @phy_pattern: DP Phy test pattern from DPCD 0x248
971  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
972  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
973  * @enhanced_frame_cap: flag for enhanced frame capability.
974  */
975 struct drm_dp_phy_test_params {
976 	int link_rate;
977 	u8 num_lanes;
978 	u8 phy_pattern;
979 	u8 hbr2_reset[2];
980 	u8 custom80[10];
981 	bool enhanced_frame_cap;
982 };
983 
984 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
985 				struct drm_dp_phy_test_params *data);
986 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
987 				struct drm_dp_phy_test_params *data, u8 dp_rev);
988 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
989 			       const u8 port_cap[4]);
990 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
991 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
992 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
993 				u8 frl_mode);
994 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
995 				u8 frl_type);
996 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
997 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
998 
999 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
1000 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
1001 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
1002 					   struct drm_connector *connector);
1003 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1004 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1005 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1006 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
1007 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
1008 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
1009 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
1010 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1011 					       const u8 port_cap[4], u8 color_spc);
1012 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
1013 
1014 #define DRM_DP_BW_OVERHEAD_MST		BIT(0)
1015 #define DRM_DP_BW_OVERHEAD_UHBR		BIT(1)
1016 #define DRM_DP_BW_OVERHEAD_SSC_REF_CLK	BIT(2)
1017 #define DRM_DP_BW_OVERHEAD_FEC		BIT(3)
1018 #define DRM_DP_BW_OVERHEAD_DSC		BIT(4)
1019 
1020 int drm_dp_bw_overhead(int lane_count, int hactive,
1021 		       int dsc_slice_count,
1022 		       int bpp_x16, unsigned long flags);
1023 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
1024 int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
1025 
1026 ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
1027 int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count,
1028 			      int bpp_x16, int symbol_size, bool is_mst);
1029 
1030 #endif /* _DRM_DP_HELPER_H_ */
1031