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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
 32struct drm_device;
 33struct drm_dp_aux;
 34struct drm_panel;
 35
 36bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
 37			  int lane_count);
 38bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
 39			      int lane_count);
 40u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
 41				     int lane);
 42u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
 43					  int lane);
 44u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
 45				   int lane);
 46
 47int 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);
 49int 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
 52void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
 53					    const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
 54void drm_dp_lttpr_link_train_clock_recovery_delay(void);
 55void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
 56					const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
 57void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
 58					      const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
 59
 60int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
 61bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
 62					  int lane_count);
 63bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
 64					int lane_count);
 65bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
 66bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
 67bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
 68
 69u8 drm_dp_link_rate_to_bw_code(int link_rate);
 70int drm_dp_bw_code_to_link_rate(u8 link_bw);
 71
 72const 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 */
 90struct 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 */
118struct 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
130void drm_dp_as_sdp_log(struct drm_printer *p,
131		       const struct drm_dp_as_sdp *as_sdp);
132void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc);
133
134bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
135bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
136
137int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
138
139static inline int
140drm_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
145static inline u8
146drm_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
151static inline bool
152drm_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
158static inline bool
159drm_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
165static inline bool
166drm_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
172static inline bool
173drm_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
179static inline bool
180drm_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
186static inline u8
187drm_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
193static inline bool
194drm_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 */
200u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
201u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
202				   bool is_edp);
203u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
204int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
205					 u8 dsc_bpc[3]);
206
207static inline bool
208drm_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
214static inline u16
215drm_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
222static inline u32
223drm_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 */
237static inline bool
238drm_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 */
244static inline bool
245drm_dp_sink_supports_fec(const u8 fec_capable)
246{
247	return fec_capable & DP_FEC_CAPABLE;
248}
249
250static inline bool
251drm_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
256static inline bool
257drm_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
262static inline bool
263drm_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 */
270static inline bool
271drm_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 */
288static inline bool
289drm_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 */
302static 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 */
319struct drm_dp_aux_msg {
320	unsigned int address;
321	u8 request;
322	u8 reply;
323	void *buffer;
324	size_t size;
325};
326
327struct cec_adapter;
328struct drm_connector;
329struct 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 */
338struct 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 */
358struct 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
523int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
524void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered);
525ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
526			 void *buffer, size_t size);
527ssize_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 */
539static 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 */
554static 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
560int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
561			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
562
563int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
564				 u8 status[DP_LINK_STATUS_SIZE]);
565
566int 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
570bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
571				    u8 real_edid_checksum);
572
573int 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]);
576bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
577			       const u8 port_cap[4], u8 type);
578bool 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);
581int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
582				   const u8 port_cap[4]);
583int 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);
586int 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);
589int 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);
592bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
593				       const u8 port_cap[4]);
594bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
595					     const u8 port_cap[4]);
596struct 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]);
599int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
600void 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);
605enum drm_mode_subconnector
606drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
607			 const u8 port_cap[4]);
608void 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
613struct drm_dp_desc;
614bool 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);
617int drm_dp_read_sink_count(struct drm_dp_aux *aux);
618
619int 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]);
622int 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]);
626int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
627int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
628int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
629bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
630bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
631
632void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
633void drm_dp_aux_init(struct drm_dp_aux *aux);
634int drm_dp_aux_register(struct drm_dp_aux *aux);
635void drm_dp_aux_unregister(struct drm_dp_aux *aux);
636
637int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
638int drm_dp_stop_crc(struct drm_dp_aux *aux);
639
640struct 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 */
653struct drm_dp_desc {
654	struct drm_dp_dpcd_ident ident;
655	u32 quirks;
656};
657
658int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
659		     bool is_branch);
660
661int 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 */
670enum 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 */
723static inline bool
724drm_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 */
741struct 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
751int
752drm_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);
755int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
756				u16 level);
757int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
758			     u16 level);
759int 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
764int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
765
766#else
767
768static 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
777void drm_dp_cec_irq(struct drm_dp_aux *aux);
778void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
779				   struct drm_connector *connector);
780void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
781void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address);
782void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
783void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
784#else
785static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
786{
787}
788
789static inline void
790drm_dp_cec_register_connector(struct drm_dp_aux *aux,
791			      struct drm_connector *connector)
792{
793}
794
795static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
796{
797}
798
799static inline void drm_dp_cec_attach(struct drm_dp_aux *aux,
800				     u16 source_physical_address)
801{
802}
803
804static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
805				       const struct edid *edid)
806{
807}
808
809static 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 */
824struct 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
833int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
834				struct drm_dp_phy_test_params *data);
835int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
836				struct drm_dp_phy_test_params *data, u8 dp_rev);
837int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
838			       const u8 port_cap[4]);
839int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
840bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
841int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
842				u8 frl_mode);
843int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
844				u8 frl_type);
845int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
846int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
847
848bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
849int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
850void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
851					   struct drm_connector *connector);
852bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
853int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
854int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
855int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
856int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
857int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
858int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
859bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
860					       const u8 port_cap[4], u8 color_spc);
861int 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
869int drm_dp_bw_overhead(int lane_count, int hactive,
870		       int dsc_slice_count,
871		       int bpp_x16, unsigned long flags);
872int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
873int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes);
874
875ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp);
876
877#endif /* _DRM_DP_HELPER_H_ */