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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
drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])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
drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])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
drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])181 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
182 {
183 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
184 		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
185 		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
186 }
187 
188 static inline u32
drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])189 drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
190 {
191 	/* Max Slicewidth = Number of Pixels * 320 */
192 	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
193 		DP_DSC_SLICE_WIDTH_MULTIPLIER;
194 }
195 
196 /* Forward Error Correction Support on DP 1.4 */
197 static inline bool
drm_dp_sink_supports_fec(const u8 fec_capable)198 drm_dp_sink_supports_fec(const u8 fec_capable)
199 {
200 	return fec_capable & DP_FEC_CAPABLE;
201 }
202 
203 static inline bool
drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])204 drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
205 {
206 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
207 }
208 
209 static inline bool
drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])210 drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
211 {
212 	return dpcd[DP_EDP_CONFIGURATION_CAP] &
213 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
214 }
215 
216 /* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
217 static inline bool
drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])218 drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
219 {
220 	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
221 		DP_MSA_TIMING_PAR_IGNORED;
222 }
223 
224 /**
225  * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
226  * @edp_dpcd: The DPCD to check
227  *
228  * Note that currently this function will return %false for panels which support various DPCD
229  * backlight features but which require the brightness be set through PWM, and don't support setting
230  * the brightness level via the DPCD.
231  *
232  * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
233  * otherwise
234  */
235 static inline bool
drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])236 drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
237 {
238 	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
239 }
240 
241 /*
242  * DisplayPort AUX channel
243  */
244 
245 /**
246  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
247  * @address: address of the (first) register to access
248  * @request: contains the type of transaction (see DP_AUX_* macros)
249  * @reply: upon completion, contains the reply type of the transaction
250  * @buffer: pointer to a transmission or reception buffer
251  * @size: size of @buffer
252  */
253 struct drm_dp_aux_msg {
254 	unsigned int address;
255 	u8 request;
256 	u8 reply;
257 	void *buffer;
258 	size_t size;
259 };
260 
261 struct cec_adapter;
262 struct edid;
263 struct drm_connector;
264 
265 /**
266  * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
267  * @lock: mutex protecting this struct
268  * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
269  * @connector: the connector this CEC adapter is associated with
270  * @unregister_work: unregister the CEC adapter
271  */
272 struct drm_dp_aux_cec {
273 	struct mutex lock;
274 	struct cec_adapter *adap;
275 	struct drm_connector *connector;
276 	struct delayed_work unregister_work;
277 };
278 
279 /**
280  * struct drm_dp_aux - DisplayPort AUX channel
281  *
282  * An AUX channel can also be used to transport I2C messages to a sink. A
283  * typical application of that is to access an EDID that's present in the sink
284  * device. The @transfer() function can also be used to execute such
285  * transactions. The drm_dp_aux_register() function registers an I2C adapter
286  * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
287  * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
288  * transfers by default; if a partial response is received, the adapter will
289  * drop down to the size given by the partial response for this transaction
290  * only.
291  */
292 struct drm_dp_aux {
293 	/**
294 	 * @name: user-visible name of this AUX channel and the
295 	 * I2C-over-AUX adapter.
296 	 *
297 	 * It's also used to specify the name of the I2C adapter. If set
298 	 * to %NULL, dev_name() of @dev will be used.
299 	 */
300 	const char *name;
301 
302 	/**
303 	 * @ddc: I2C adapter that can be used for I2C-over-AUX
304 	 * communication
305 	 */
306 	struct i2c_adapter ddc;
307 
308 	/**
309 	 * @dev: pointer to struct device that is the parent for this
310 	 * AUX channel.
311 	 */
312 	struct device *dev;
313 
314 	/**
315 	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
316 	 * Beware, this may be %NULL before drm_dp_aux_register() has been
317 	 * called.
318 	 *
319 	 * It should be set to the &drm_device that will be using this AUX
320 	 * channel as early as possible. For many graphics drivers this should
321 	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
322 	 * this field later so long as it's assigned before calling
323 	 * drm_dp_aux_register().
324 	 */
325 	struct drm_device *drm_dev;
326 
327 	/**
328 	 * @crtc: backpointer to the crtc that is currently using this
329 	 * AUX channel
330 	 */
331 	struct drm_crtc *crtc;
332 
333 	/**
334 	 * @hw_mutex: internal mutex used for locking transfers.
335 	 *
336 	 * Note that if the underlying hardware is shared among multiple
337 	 * channels, the driver needs to do additional locking to
338 	 * prevent concurrent access.
339 	 */
340 	struct mutex hw_mutex;
341 
342 	/**
343 	 * @crc_work: worker that captures CRCs for each frame
344 	 */
345 	struct work_struct crc_work;
346 
347 	/**
348 	 * @crc_count: counter of captured frame CRCs
349 	 */
350 	u8 crc_count;
351 
352 	/**
353 	 * @transfer: transfers a message representing a single AUX
354 	 * transaction.
355 	 *
356 	 * This is a hardware-specific implementation of how
357 	 * transactions are executed that the drivers must provide.
358 	 *
359 	 * A pointer to a &drm_dp_aux_msg structure describing the
360 	 * transaction is passed into this function. Upon success, the
361 	 * implementation should return the number of payload bytes that
362 	 * were transferred, or a negative error-code on failure.
363 	 *
364 	 * Helpers will propagate these errors, with the exception of
365 	 * the %-EBUSY error, which causes a transaction to be retried.
366 	 * On a short, helpers will return %-EPROTO to make it simpler
367 	 * to check for failure.
368 	 *
369 	 * The @transfer() function must only modify the reply field of
370 	 * the &drm_dp_aux_msg structure. The retry logic and i2c
371 	 * helpers assume this is the case.
372 	 *
373 	 * Also note that this callback can be called no matter the
374 	 * state @dev is in and also no matter what state the panel is
375 	 * in. It's expected:
376 	 *
377 	 * - If the @dev providing the AUX bus is currently unpowered then
378 	 *   it will power itself up for the transfer.
379 	 *
380 	 * - If we're on eDP (using a drm_panel) and the panel is not in a
381 	 *   state where it can respond (it's not powered or it's in a
382 	 *   low power state) then this function may return an error, but
383 	 *   not crash. It's up to the caller of this code to make sure that
384 	 *   the panel is powered on if getting an error back is not OK. If a
385 	 *   drm_panel driver is initiating a DP AUX transfer it may power
386 	 *   itself up however it wants. All other code should ensure that
387 	 *   the pre_enable() bridge chain (which eventually calls the
388 	 *   drm_panel prepare function) has powered the panel.
389 	 */
390 	ssize_t (*transfer)(struct drm_dp_aux *aux,
391 			    struct drm_dp_aux_msg *msg);
392 
393 	/**
394 	 * @wait_hpd_asserted: wait for HPD to be asserted
395 	 *
396 	 * This is mainly useful for eDP panels drivers to wait for an eDP
397 	 * panel to finish powering on. This is an optional function.
398 	 *
399 	 * This function will efficiently wait for the HPD signal to be
400 	 * asserted. The `wait_us` parameter that is passed in says that we
401 	 * know that the HPD signal is expected to be asserted within `wait_us`
402 	 * microseconds. This function could wait for longer than `wait_us` if
403 	 * the logic in the DP controller has a long debouncing time. The
404 	 * important thing is that if this function returns success that the
405 	 * DP controller is ready to send AUX transactions.
406 	 *
407 	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
408 	 * expired and HPD wasn't asserted. This function should not print
409 	 * timeout errors to the log.
410 	 *
411 	 * The semantics of this function are designed to match the
412 	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
413 	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
414 	 *
415 	 * NOTE: this function specifically reports the state of the HPD pin
416 	 * that's associated with the DP AUX channel. This is different from
417 	 * the HPD concept in much of the rest of DRM which is more about
418 	 * physical presence of a display. For eDP, for instance, a display is
419 	 * assumed always present even if the HPD pin is deasserted.
420 	 */
421 	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
422 
423 	/**
424 	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
425 	 */
426 	unsigned i2c_nack_count;
427 	/**
428 	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
429 	 */
430 	unsigned i2c_defer_count;
431 	/**
432 	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
433 	 */
434 	struct drm_dp_aux_cec cec;
435 	/**
436 	 * @is_remote: Is this AUX CH actually using sideband messaging.
437 	 */
438 	bool is_remote;
439 };
440 
441 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
442 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
443 			 void *buffer, size_t size);
444 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
445 			  void *buffer, size_t size);
446 
447 /**
448  * drm_dp_dpcd_readb() - read a single byte from the DPCD
449  * @aux: DisplayPort AUX channel
450  * @offset: address of the register to read
451  * @valuep: location where the value of the register will be stored
452  *
453  * Returns the number of bytes transferred (1) on success, or a negative
454  * error code on failure.
455  */
drm_dp_dpcd_readb(struct drm_dp_aux * aux,unsigned int offset,u8 * valuep)456 static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
457 					unsigned int offset, u8 *valuep)
458 {
459 	return drm_dp_dpcd_read(aux, offset, valuep, 1);
460 }
461 
462 /**
463  * drm_dp_dpcd_writeb() - write a single byte to the DPCD
464  * @aux: DisplayPort AUX channel
465  * @offset: address of the register to write
466  * @value: value to write to the register
467  *
468  * Returns the number of bytes transferred (1) on success, or a negative
469  * error code on failure.
470  */
drm_dp_dpcd_writeb(struct drm_dp_aux * aux,unsigned int offset,u8 value)471 static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
472 					 unsigned int offset, u8 value)
473 {
474 	return drm_dp_dpcd_write(aux, offset, &value, 1);
475 }
476 
477 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
478 			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
479 
480 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
481 				 u8 status[DP_LINK_STATUS_SIZE]);
482 
483 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
484 				     enum drm_dp_phy dp_phy,
485 				     u8 link_status[DP_LINK_STATUS_SIZE]);
486 
487 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
488 				    u8 real_edid_checksum);
489 
490 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
491 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
492 				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
493 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
494 			       const u8 port_cap[4], u8 type);
495 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
496 			       const u8 port_cap[4],
497 			       const struct edid *edid);
498 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
499 				   const u8 port_cap[4]);
500 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
501 				     const u8 port_cap[4],
502 				     const struct edid *edid);
503 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
504 				     const u8 port_cap[4],
505 				     const struct edid *edid);
506 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
507 			      const u8 port_cap[4],
508 			      const struct edid *edid);
509 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
510 				       const u8 port_cap[4]);
511 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
512 					     const u8 port_cap[4]);
513 struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
514 						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
515 						const u8 port_cap[4]);
516 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
517 void drm_dp_downstream_debug(struct seq_file *m,
518 			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
519 			     const u8 port_cap[4],
520 			     const struct edid *edid,
521 			     struct drm_dp_aux *aux);
522 enum drm_mode_subconnector
523 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
524 			 const u8 port_cap[4]);
525 void drm_dp_set_subconnector_property(struct drm_connector *connector,
526 				      enum drm_connector_status status,
527 				      const u8 *dpcd,
528 				      const u8 port_cap[4]);
529 
530 struct drm_dp_desc;
531 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
532 				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
533 				const struct drm_dp_desc *desc);
534 int drm_dp_read_sink_count(struct drm_dp_aux *aux);
535 
536 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
537 				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
538 				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
539 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
540 			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
541 			       enum drm_dp_phy dp_phy,
542 			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
543 int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
544 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
545 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
546 bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
547 bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
548 
549 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
550 void drm_dp_aux_init(struct drm_dp_aux *aux);
551 int drm_dp_aux_register(struct drm_dp_aux *aux);
552 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
553 
554 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
555 int drm_dp_stop_crc(struct drm_dp_aux *aux);
556 
557 struct drm_dp_dpcd_ident {
558 	u8 oui[3];
559 	u8 device_id[6];
560 	u8 hw_rev;
561 	u8 sw_major_rev;
562 	u8 sw_minor_rev;
563 } __packed;
564 
565 /**
566  * struct drm_dp_desc - DP branch/sink device descriptor
567  * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
568  * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
569  */
570 struct drm_dp_desc {
571 	struct drm_dp_dpcd_ident ident;
572 	u32 quirks;
573 };
574 
575 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
576 		     bool is_branch);
577 
578 /**
579  * enum drm_dp_quirk - Display Port sink/branch device specific quirks
580  *
581  * Display Port sink and branch devices in the wild have a variety of bugs, try
582  * to collect them here. The quirks are shared, but it's up to the drivers to
583  * implement workarounds for them.
584  */
585 enum drm_dp_quirk {
586 	/**
587 	 * @DP_DPCD_QUIRK_CONSTANT_N:
588 	 *
589 	 * The device requires main link attributes Mvid and Nvid to be limited
590 	 * to 16 bits. So will give a constant value (0x8000) for compatability.
591 	 */
592 	DP_DPCD_QUIRK_CONSTANT_N,
593 	/**
594 	 * @DP_DPCD_QUIRK_NO_PSR:
595 	 *
596 	 * The device does not support PSR even if reports that it supports or
597 	 * driver still need to implement proper handling for such device.
598 	 */
599 	DP_DPCD_QUIRK_NO_PSR,
600 	/**
601 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
602 	 *
603 	 * The device does not set SINK_COUNT to a non-zero value.
604 	 * The driver should ignore SINK_COUNT during detection. Note that
605 	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
606 	 */
607 	DP_DPCD_QUIRK_NO_SINK_COUNT,
608 	/**
609 	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
610 	 *
611 	 * The device supports MST DSC despite not supporting Virtual DPCD.
612 	 * The DSC caps can be read from the physical aux instead.
613 	 */
614 	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
615 	/**
616 	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
617 	 *
618 	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
619 	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
620 	 */
621 	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
622 };
623 
624 /**
625  * drm_dp_has_quirk() - does the DP device have a specific quirk
626  * @desc: Device descriptor filled by drm_dp_read_desc()
627  * @quirk: Quirk to query for
628  *
629  * Return true if DP device identified by @desc has @quirk.
630  */
631 static inline bool
drm_dp_has_quirk(const struct drm_dp_desc * desc,enum drm_dp_quirk quirk)632 drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
633 {
634 	return desc->quirks & BIT(quirk);
635 }
636 
637 /**
638  * struct drm_edp_backlight_info - Probed eDP backlight info struct
639  * @pwmgen_bit_count: The pwmgen bit count
640  * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
641  * @max: The maximum backlight level that may be set
642  * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
643  * @aux_enable: Does the panel support the AUX enable cap?
644  * @aux_set: Does the panel support setting the brightness through AUX?
645  *
646  * This structure contains various data about an eDP backlight, which can be populated by using
647  * drm_edp_backlight_init().
648  */
649 struct drm_edp_backlight_info {
650 	u8 pwmgen_bit_count;
651 	u8 pwm_freq_pre_divider;
652 	u16 max;
653 
654 	bool lsb_reg_used : 1;
655 	bool aux_enable : 1;
656 	bool aux_set : 1;
657 };
658 
659 int
660 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
661 		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
662 		       u16 *current_level, u8 *current_mode);
663 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
664 				u16 level);
665 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
666 			     u16 level);
667 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
668 
669 #if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
670 	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
671 
672 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
673 
674 #else
675 
drm_panel_dp_aux_backlight(struct drm_panel * panel,struct drm_dp_aux * aux)676 static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
677 					     struct drm_dp_aux *aux)
678 {
679 	return 0;
680 }
681 
682 #endif
683 
684 #ifdef CONFIG_DRM_DP_CEC
685 void drm_dp_cec_irq(struct drm_dp_aux *aux);
686 void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
687 				   struct drm_connector *connector);
688 void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
689 void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
690 void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
691 #else
drm_dp_cec_irq(struct drm_dp_aux * aux)692 static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
693 {
694 }
695 
696 static inline void
drm_dp_cec_register_connector(struct drm_dp_aux * aux,struct drm_connector * connector)697 drm_dp_cec_register_connector(struct drm_dp_aux *aux,
698 			      struct drm_connector *connector)
699 {
700 }
701 
drm_dp_cec_unregister_connector(struct drm_dp_aux * aux)702 static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
703 {
704 }
705 
drm_dp_cec_set_edid(struct drm_dp_aux * aux,const struct edid * edid)706 static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
707 				       const struct edid *edid)
708 {
709 }
710 
drm_dp_cec_unset_edid(struct drm_dp_aux * aux)711 static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
712 {
713 }
714 
715 #endif
716 
717 /**
718  * struct drm_dp_phy_test_params - DP Phy Compliance parameters
719  * @link_rate: Requested Link rate from DPCD 0x219
720  * @num_lanes: Number of lanes requested by sing through DPCD 0x220
721  * @phy_pattern: DP Phy test pattern from DPCD 0x248
722  * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
723  * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
724  * @enhanced_frame_cap: flag for enhanced frame capability.
725  */
726 struct drm_dp_phy_test_params {
727 	int link_rate;
728 	u8 num_lanes;
729 	u8 phy_pattern;
730 	u8 hbr2_reset[2];
731 	u8 custom80[10];
732 	bool enhanced_frame_cap;
733 };
734 
735 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
736 				struct drm_dp_phy_test_params *data);
737 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
738 				struct drm_dp_phy_test_params *data, u8 dp_rev);
739 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
740 			       const u8 port_cap[4]);
741 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
742 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
743 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
744 				u8 frl_mode);
745 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
746 				u8 frl_type);
747 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
748 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
749 
750 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
751 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
752 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
753 					   struct drm_connector *connector);
754 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
755 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
756 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
757 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
758 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
759 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
760 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
761 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
762 					       const u8 port_cap[4], u8 color_spc);
763 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
764 
765 #endif /* _DRM_DP_HELPER_H_ */
766