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/types.h> |
27 | #include <linux/i2c.h> |
28 | #include <linux/delay.h> |
29 | |
30 | /* |
31 | * Unless otherwise noted, all values are from the DP 1.1a spec. Note that |
32 | * DP and DPCD versions are independent. Differences from 1.0 are not noted, |
33 | * 1.0 devices basically don't exist in the wild. |
34 | * |
35 | * Abbreviations, in chronological order: |
36 | * |
37 | * eDP: Embedded DisplayPort version 1 |
38 | * DPI: DisplayPort Interoperability Guideline v1.1a |
39 | * 1.2: DisplayPort 1.2 |
40 | * |
41 | * 1.2 formally includes both eDP and DPI definitions. |
42 | */ |
43 | |
44 | #define DP_AUX_I2C_WRITE 0x0 |
45 | #define DP_AUX_I2C_READ 0x1 |
46 | #define DP_AUX_I2C_STATUS 0x2 |
47 | #define DP_AUX_I2C_MOT 0x4 |
48 | #define DP_AUX_NATIVE_WRITE 0x8 |
49 | #define DP_AUX_NATIVE_READ 0x9 |
50 | |
51 | #define DP_AUX_NATIVE_REPLY_ACK (0x0 << 0) |
52 | #define DP_AUX_NATIVE_REPLY_NACK (0x1 << 0) |
53 | #define DP_AUX_NATIVE_REPLY_DEFER (0x2 << 0) |
54 | #define DP_AUX_NATIVE_REPLY_MASK (0x3 << 0) |
55 | |
56 | #define DP_AUX_I2C_REPLY_ACK (0x0 << 2) |
57 | #define DP_AUX_I2C_REPLY_NACK (0x1 << 2) |
58 | #define DP_AUX_I2C_REPLY_DEFER (0x2 << 2) |
59 | #define DP_AUX_I2C_REPLY_MASK (0x3 << 2) |
60 | |
61 | /* AUX CH addresses */ |
62 | /* DPCD */ |
63 | #define DP_DPCD_REV 0x000 |
64 | |
65 | #define DP_MAX_LINK_RATE 0x001 |
66 | |
67 | #define DP_MAX_LANE_COUNT 0x002 |
68 | # define DP_MAX_LANE_COUNT_MASK 0x1f |
69 | # define DP_TPS3_SUPPORTED (1 << 6) /* 1.2 */ |
70 | # define DP_ENHANCED_FRAME_CAP (1 << 7) |
71 | |
72 | #define DP_MAX_DOWNSPREAD 0x003 |
73 | # define DP_NO_AUX_HANDSHAKE_LINK_TRAINING (1 << 6) |
74 | |
75 | #define DP_NORP 0x004 |
76 | |
77 | #define DP_DOWNSTREAMPORT_PRESENT 0x005 |
78 | # define DP_DWN_STRM_PORT_PRESENT (1 << 0) |
79 | # define DP_DWN_STRM_PORT_TYPE_MASK 0x06 |
80 | # define DP_DWN_STRM_PORT_TYPE_DP (0 << 1) |
81 | # define DP_DWN_STRM_PORT_TYPE_ANALOG (1 << 1) |
82 | # define DP_DWN_STRM_PORT_TYPE_TMDS (2 << 1) |
83 | # define DP_DWN_STRM_PORT_TYPE_OTHER (3 << 1) |
84 | # define DP_FORMAT_CONVERSION (1 << 3) |
85 | # define DP_DETAILED_CAP_INFO_AVAILABLE (1 << 4) /* DPI */ |
86 | |
87 | #define DP_MAIN_LINK_CHANNEL_CODING 0x006 |
88 | |
89 | #define DP_DOWN_STREAM_PORT_COUNT 0x007 |
90 | # define DP_PORT_COUNT_MASK 0x0f |
91 | # define DP_MSA_TIMING_PAR_IGNORED (1 << 6) /* eDP */ |
92 | # define DP_OUI_SUPPORT (1 << 7) |
93 | |
94 | #define DP_I2C_SPEED_CAP 0x00c /* DPI */ |
95 | # define DP_I2C_SPEED_1K 0x01 |
96 | # define DP_I2C_SPEED_5K 0x02 |
97 | # define DP_I2C_SPEED_10K 0x04 |
98 | # define DP_I2C_SPEED_100K 0x08 |
99 | # define DP_I2C_SPEED_400K 0x10 |
100 | # define DP_I2C_SPEED_1M 0x20 |
101 | |
102 | #define DP_EDP_CONFIGURATION_CAP 0x00d /* XXX 1.2? */ |
103 | #define DP_TRAINING_AUX_RD_INTERVAL 0x00e /* XXX 1.2? */ |
104 | |
105 | /* Multiple stream transport */ |
106 | #define DP_MSTM_CAP 0x021 /* 1.2 */ |
107 | # define DP_MST_CAP (1 << 0) |
108 | |
109 | #define DP_PSR_SUPPORT 0x070 /* XXX 1.2? */ |
110 | # define DP_PSR_IS_SUPPORTED 1 |
111 | #define DP_PSR_CAPS 0x071 /* XXX 1.2? */ |
112 | # define DP_PSR_NO_TRAIN_ON_EXIT 1 |
113 | # define DP_PSR_SETUP_TIME_330 (0 << 1) |
114 | # define DP_PSR_SETUP_TIME_275 (1 << 1) |
115 | # define DP_PSR_SETUP_TIME_220 (2 << 1) |
116 | # define DP_PSR_SETUP_TIME_165 (3 << 1) |
117 | # define DP_PSR_SETUP_TIME_110 (4 << 1) |
118 | # define DP_PSR_SETUP_TIME_55 (5 << 1) |
119 | # define DP_PSR_SETUP_TIME_0 (6 << 1) |
120 | # define DP_PSR_SETUP_TIME_MASK (7 << 1) |
121 | # define DP_PSR_SETUP_TIME_SHIFT 1 |
122 | |
123 | /* |
124 | * 0x80-0x8f describe downstream port capabilities, but there are two layouts |
125 | * based on whether DP_DETAILED_CAP_INFO_AVAILABLE was set. If it was not, |
126 | * each port's descriptor is one byte wide. If it was set, each port's is |
127 | * four bytes wide, starting with the one byte from the base info. As of |
128 | * DP interop v1.1a only VGA defines additional detail. |
129 | */ |
130 | |
131 | /* offset 0 */ |
132 | #define DP_DOWNSTREAM_PORT_0 0x80 |
133 | # define DP_DS_PORT_TYPE_MASK (7 << 0) |
134 | # define DP_DS_PORT_TYPE_DP 0 |
135 | # define DP_DS_PORT_TYPE_VGA 1 |
136 | # define DP_DS_PORT_TYPE_DVI 2 |
137 | # define DP_DS_PORT_TYPE_HDMI 3 |
138 | # define DP_DS_PORT_TYPE_NON_EDID 4 |
139 | # define DP_DS_PORT_HPD (1 << 3) |
140 | /* offset 1 for VGA is maximum megapixels per second / 8 */ |
141 | /* offset 2 */ |
142 | # define DP_DS_VGA_MAX_BPC_MASK (3 << 0) |
143 | # define DP_DS_VGA_8BPC 0 |
144 | # define DP_DS_VGA_10BPC 1 |
145 | # define DP_DS_VGA_12BPC 2 |
146 | # define DP_DS_VGA_16BPC 3 |
147 | |
148 | /* link configuration */ |
149 | #define DP_LINK_BW_SET 0x100 |
150 | # define DP_LINK_BW_1_62 0x06 |
151 | # define DP_LINK_BW_2_7 0x0a |
152 | # define DP_LINK_BW_5_4 0x14 /* 1.2 */ |
153 | |
154 | #define DP_LANE_COUNT_SET 0x101 |
155 | # define DP_LANE_COUNT_MASK 0x0f |
156 | # define DP_LANE_COUNT_ENHANCED_FRAME_EN (1 << 7) |
157 | |
158 | #define DP_TRAINING_PATTERN_SET 0x102 |
159 | # define DP_TRAINING_PATTERN_DISABLE 0 |
160 | # define DP_TRAINING_PATTERN_1 1 |
161 | # define DP_TRAINING_PATTERN_2 2 |
162 | # define DP_TRAINING_PATTERN_3 3 /* 1.2 */ |
163 | # define DP_TRAINING_PATTERN_MASK 0x3 |
164 | |
165 | # define DP_LINK_QUAL_PATTERN_DISABLE (0 << 2) |
166 | # define DP_LINK_QUAL_PATTERN_D10_2 (1 << 2) |
167 | # define DP_LINK_QUAL_PATTERN_ERROR_RATE (2 << 2) |
168 | # define DP_LINK_QUAL_PATTERN_PRBS7 (3 << 2) |
169 | # define DP_LINK_QUAL_PATTERN_MASK (3 << 2) |
170 | |
171 | # define DP_RECOVERED_CLOCK_OUT_EN (1 << 4) |
172 | # define DP_LINK_SCRAMBLING_DISABLE (1 << 5) |
173 | |
174 | # define DP_SYMBOL_ERROR_COUNT_BOTH (0 << 6) |
175 | # define DP_SYMBOL_ERROR_COUNT_DISPARITY (1 << 6) |
176 | # define DP_SYMBOL_ERROR_COUNT_SYMBOL (2 << 6) |
177 | # define DP_SYMBOL_ERROR_COUNT_MASK (3 << 6) |
178 | |
179 | #define DP_TRAINING_LANE0_SET 0x103 |
180 | #define DP_TRAINING_LANE1_SET 0x104 |
181 | #define DP_TRAINING_LANE2_SET 0x105 |
182 | #define DP_TRAINING_LANE3_SET 0x106 |
183 | |
184 | # define DP_TRAIN_VOLTAGE_SWING_MASK 0x3 |
185 | # define DP_TRAIN_VOLTAGE_SWING_SHIFT 0 |
186 | # define DP_TRAIN_MAX_SWING_REACHED (1 << 2) |
187 | # define DP_TRAIN_VOLTAGE_SWING_400 (0 << 0) |
188 | # define DP_TRAIN_VOLTAGE_SWING_600 (1 << 0) |
189 | # define DP_TRAIN_VOLTAGE_SWING_800 (2 << 0) |
190 | # define DP_TRAIN_VOLTAGE_SWING_1200 (3 << 0) |
191 | |
192 | # define DP_TRAIN_PRE_EMPHASIS_MASK (3 << 3) |
193 | # define DP_TRAIN_PRE_EMPHASIS_0 (0 << 3) |
194 | # define DP_TRAIN_PRE_EMPHASIS_3_5 (1 << 3) |
195 | # define DP_TRAIN_PRE_EMPHASIS_6 (2 << 3) |
196 | # define DP_TRAIN_PRE_EMPHASIS_9_5 (3 << 3) |
197 | |
198 | # define DP_TRAIN_PRE_EMPHASIS_SHIFT 3 |
199 | # define DP_TRAIN_MAX_PRE_EMPHASIS_REACHED (1 << 5) |
200 | |
201 | #define DP_DOWNSPREAD_CTRL 0x107 |
202 | # define DP_SPREAD_AMP_0_5 (1 << 4) |
203 | # define DP_MSA_TIMING_PAR_IGNORE_EN (1 << 7) /* eDP */ |
204 | |
205 | #define DP_MAIN_LINK_CHANNEL_CODING_SET 0x108 |
206 | # define DP_SET_ANSI_8B10B (1 << 0) |
207 | |
208 | #define DP_I2C_SPEED_CONTROL_STATUS 0x109 /* DPI */ |
209 | /* bitmask as for DP_I2C_SPEED_CAP */ |
210 | |
211 | #define DP_EDP_CONFIGURATION_SET 0x10a /* XXX 1.2? */ |
212 | |
213 | #define DP_MSTM_CTRL 0x111 /* 1.2 */ |
214 | # define DP_MST_EN (1 << 0) |
215 | # define DP_UP_REQ_EN (1 << 1) |
216 | # define DP_UPSTREAM_IS_SRC (1 << 2) |
217 | |
218 | #define DP_PSR_EN_CFG 0x170 /* XXX 1.2? */ |
219 | # define DP_PSR_ENABLE (1 << 0) |
220 | # define DP_PSR_MAIN_LINK_ACTIVE (1 << 1) |
221 | # define DP_PSR_CRC_VERIFICATION (1 << 2) |
222 | # define DP_PSR_FRAME_CAPTURE (1 << 3) |
223 | |
224 | #define DP_SINK_COUNT 0x200 |
225 | /* prior to 1.2 bit 7 was reserved mbz */ |
226 | # define DP_GET_SINK_COUNT(x) ((((x) & 0x80) >> 1) | ((x) & 0x3f)) |
227 | # define DP_SINK_CP_READY (1 << 6) |
228 | |
229 | #define DP_DEVICE_SERVICE_IRQ_VECTOR 0x201 |
230 | # define DP_REMOTE_CONTROL_COMMAND_PENDING (1 << 0) |
231 | # define DP_AUTOMATED_TEST_REQUEST (1 << 1) |
232 | # define DP_CP_IRQ (1 << 2) |
233 | # define DP_SINK_SPECIFIC_IRQ (1 << 6) |
234 | |
235 | #define DP_LANE0_1_STATUS 0x202 |
236 | #define DP_LANE2_3_STATUS 0x203 |
237 | # define DP_LANE_CR_DONE (1 << 0) |
238 | # define DP_LANE_CHANNEL_EQ_DONE (1 << 1) |
239 | # define DP_LANE_SYMBOL_LOCKED (1 << 2) |
240 | |
241 | #define DP_CHANNEL_EQ_BITS (DP_LANE_CR_DONE | \ |
242 | DP_LANE_CHANNEL_EQ_DONE | \ |
243 | DP_LANE_SYMBOL_LOCKED) |
244 | |
245 | #define DP_LANE_ALIGN_STATUS_UPDATED 0x204 |
246 | |
247 | #define DP_INTERLANE_ALIGN_DONE (1 << 0) |
248 | #define DP_DOWNSTREAM_PORT_STATUS_CHANGED (1 << 6) |
249 | #define DP_LINK_STATUS_UPDATED (1 << 7) |
250 | |
251 | #define DP_SINK_STATUS 0x205 |
252 | |
253 | #define DP_RECEIVE_PORT_0_STATUS (1 << 0) |
254 | #define DP_RECEIVE_PORT_1_STATUS (1 << 1) |
255 | |
256 | #define DP_ADJUST_REQUEST_LANE0_1 0x206 |
257 | #define DP_ADJUST_REQUEST_LANE2_3 0x207 |
258 | # define DP_ADJUST_VOLTAGE_SWING_LANE0_MASK 0x03 |
259 | # define DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT 0 |
260 | # define DP_ADJUST_PRE_EMPHASIS_LANE0_MASK 0x0c |
261 | # define DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT 2 |
262 | # define DP_ADJUST_VOLTAGE_SWING_LANE1_MASK 0x30 |
263 | # define DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT 4 |
264 | # define DP_ADJUST_PRE_EMPHASIS_LANE1_MASK 0xc0 |
265 | # define DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT 6 |
266 | |
267 | #define DP_TEST_REQUEST 0x218 |
268 | # define DP_TEST_LINK_TRAINING (1 << 0) |
269 | # define DP_TEST_LINK_VIDEO_PATTERN (1 << 1) |
270 | # define DP_TEST_LINK_EDID_READ (1 << 2) |
271 | # define DP_TEST_LINK_PHY_TEST_PATTERN (1 << 3) /* DPCD >= 1.1 */ |
272 | # define DP_TEST_LINK_FAUX_PATTERN (1 << 4) /* DPCD >= 1.2 */ |
273 | |
274 | #define DP_TEST_LINK_RATE 0x219 |
275 | # define DP_LINK_RATE_162 (0x6) |
276 | # define DP_LINK_RATE_27 (0xa) |
277 | |
278 | #define DP_TEST_LANE_COUNT 0x220 |
279 | |
280 | #define DP_TEST_PATTERN 0x221 |
281 | |
282 | #define DP_TEST_CRC_R_CR 0x240 |
283 | #define DP_TEST_CRC_G_Y 0x242 |
284 | #define DP_TEST_CRC_B_CB 0x244 |
285 | |
286 | #define DP_TEST_SINK_MISC 0x246 |
287 | #define DP_TEST_CRC_SUPPORTED (1 << 5) |
288 | |
289 | #define DP_TEST_RESPONSE 0x260 |
290 | # define DP_TEST_ACK (1 << 0) |
291 | # define DP_TEST_NAK (1 << 1) |
292 | # define DP_TEST_EDID_CHECKSUM_WRITE (1 << 2) |
293 | |
294 | #define DP_TEST_SINK 0x270 |
295 | #define DP_TEST_SINK_START (1 << 0) |
296 | |
297 | #define DP_SOURCE_OUI 0x300 |
298 | #define DP_SINK_OUI 0x400 |
299 | #define DP_BRANCH_OUI 0x500 |
300 | |
301 | #define DP_SET_POWER 0x600 |
302 | # define DP_SET_POWER_D0 0x1 |
303 | # define DP_SET_POWER_D3 0x2 |
304 | # define DP_SET_POWER_MASK 0x3 |
305 | |
306 | #define DP_PSR_ERROR_STATUS 0x2006 /* XXX 1.2? */ |
307 | # define DP_PSR_LINK_CRC_ERROR (1 << 0) |
308 | # define DP_PSR_RFB_STORAGE_ERROR (1 << 1) |
309 | |
310 | #define DP_PSR_ESI 0x2007 /* XXX 1.2? */ |
311 | # define DP_PSR_CAPS_CHANGE (1 << 0) |
312 | |
313 | #define DP_PSR_STATUS 0x2008 /* XXX 1.2? */ |
314 | # define DP_PSR_SINK_INACTIVE 0 |
315 | # define DP_PSR_SINK_ACTIVE_SRC_SYNCED 1 |
316 | # define DP_PSR_SINK_ACTIVE_RFB 2 |
317 | # define DP_PSR_SINK_ACTIVE_SINK_SYNCED 3 |
318 | # define DP_PSR_SINK_ACTIVE_RESYNC 4 |
319 | # define DP_PSR_SINK_INTERNAL_ERROR 7 |
320 | # define DP_PSR_SINK_STATE_MASK 0x07 |
321 | |
322 | #define MODE_I2C_START 1 |
323 | #define MODE_I2C_WRITE 2 |
324 | #define MODE_I2C_READ 4 |
325 | #define MODE_I2C_STOP 8 |
326 | |
327 | /** |
328 | * struct i2c_algo_dp_aux_data - driver interface structure for i2c over dp |
329 | * aux algorithm |
330 | * @running: set by the algo indicating whether an i2c is ongoing or whether |
331 | * the i2c bus is quiescent |
332 | * @address: i2c target address for the currently ongoing transfer |
333 | * @aux_ch: driver callback to transfer a single byte of the i2c payload |
334 | */ |
335 | struct i2c_algo_dp_aux_data { |
336 | bool running; |
337 | u16 address; |
338 | int (*aux_ch) (struct i2c_adapter *adapter, |
339 | int mode, uint8_t write_byte, |
340 | uint8_t *read_byte); |
341 | }; |
342 | |
343 | int |
344 | i2c_dp_aux_add_bus(struct i2c_adapter *adapter); |
345 | |
346 | |
347 | #define DP_LINK_STATUS_SIZE 6 |
348 | bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], |
349 | int lane_count); |
350 | bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], |
351 | int lane_count); |
352 | u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], |
353 | int lane); |
354 | u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], |
355 | int lane); |
356 | |
357 | #define DP_RECEIVER_CAP_SIZE 0xf |
358 | #define EDP_PSR_RECEIVER_CAP_SIZE 2 |
359 | |
360 | void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]); |
361 | void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]); |
362 | |
363 | u8 drm_dp_link_rate_to_bw_code(int link_rate); |
364 | int drm_dp_bw_code_to_link_rate(u8 link_bw); |
365 | |
366 | struct { |
367 | u8 ; /* Secondary Data Packet ID */ |
368 | u8 ; /* Secondary Data Packet Type */ |
369 | u8 ; /* 7:5 reserved, 4:0 revision number */ |
370 | u8 ; /* 7:5 reserved, 4:0 number of valid data bytes */ |
371 | } __packed; |
372 | |
373 | #define 0x1F |
374 | #define 0x1F |
375 | |
376 | struct edp_vsc_psr { |
377 | struct edp_sdp_header ; |
378 | u8 DB0; /* Stereo Interface */ |
379 | u8 DB1; /* 0 - PSR State; 1 - Update RFB; 2 - CRC Valid */ |
380 | u8 DB2; /* CRC value bits 7:0 of the R or Cr component */ |
381 | u8 DB3; /* CRC value bits 15:8 of the R or Cr component */ |
382 | u8 DB4; /* CRC value bits 7:0 of the G or Y component */ |
383 | u8 DB5; /* CRC value bits 15:8 of the G or Y component */ |
384 | u8 DB6; /* CRC value bits 7:0 of the B or Cb component */ |
385 | u8 DB7; /* CRC value bits 15:8 of the B or Cb component */ |
386 | u8 DB8_31[24]; /* Reserved */ |
387 | } __packed; |
388 | |
389 | #define EDP_VSC_PSR_STATE_ACTIVE (1<<0) |
390 | #define EDP_VSC_PSR_UPDATE_RFB (1<<1) |
391 | #define EDP_VSC_PSR_CRC_VALUES_VALID (1<<2) |
392 | |
393 | static inline int |
394 | drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) |
395 | { |
396 | return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]); |
397 | } |
398 | |
399 | static inline u8 |
400 | drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) |
401 | { |
402 | return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK; |
403 | } |
404 | |
405 | static inline bool |
406 | drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) |
407 | { |
408 | return dpcd[DP_DPCD_REV] >= 0x11 && |
409 | (dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP); |
410 | } |
411 | |
412 | /* |
413 | * DisplayPort AUX channel |
414 | */ |
415 | |
416 | /** |
417 | * struct drm_dp_aux_msg - DisplayPort AUX channel transaction |
418 | * @address: address of the (first) register to access |
419 | * @request: contains the type of transaction (see DP_AUX_* macros) |
420 | * @reply: upon completion, contains the reply type of the transaction |
421 | * @buffer: pointer to a transmission or reception buffer |
422 | * @size: size of @buffer |
423 | */ |
424 | struct drm_dp_aux_msg { |
425 | unsigned int address; |
426 | u8 request; |
427 | u8 reply; |
428 | void *buffer; |
429 | size_t size; |
430 | }; |
431 | |
432 | /** |
433 | * struct drm_dp_aux - DisplayPort AUX channel |
434 | * @ddc: I2C adapter that can be used for I2C-over-AUX communication |
435 | * @dev: pointer to struct device that is the parent for this AUX channel |
436 | * @transfer: transfers a message representing a single AUX transaction |
437 | * |
438 | * The .dev field should be set to a pointer to the device that implements |
439 | * the AUX channel. |
440 | * |
441 | * The .name field may be used to specify the name of the I2C adapter. If set to |
442 | * NULL, dev_name() of .dev will be used. |
443 | * |
444 | * Drivers provide a hardware-specific implementation of how transactions |
445 | * are executed via the .transfer() function. A pointer to a drm_dp_aux_msg |
446 | * structure describing the transaction is passed into this function. Upon |
447 | * success, the implementation should return the number of payload bytes |
448 | * that were transferred, or a negative error-code on failure. Helpers |
449 | * propagate errors from the .transfer() function, with the exception of |
450 | * the -EBUSY error, which causes a transaction to be retried. On a short, |
451 | * helpers will return -EPROTO to make it simpler to check for failure. |
452 | * |
453 | * An AUX channel can also be used to transport I2C messages to a sink. A |
454 | * typical application of that is to access an EDID that's present in the |
455 | * sink device. The .transfer() function can also be used to execute such |
456 | * transactions. The drm_dp_aux_register_i2c_bus() function registers an |
457 | * I2C adapter that can be passed to drm_probe_ddc(). Upon removal, drivers |
458 | * should call drm_dp_aux_unregister_i2c_bus() to remove the I2C adapter. |
459 | * |
460 | * Note that the aux helper code assumes that the .transfer() function |
461 | * only modifies the reply field of the drm_dp_aux_msg structure. The |
462 | * retry logic and i2c helpers assume this is the case. |
463 | */ |
464 | struct drm_dp_aux { |
465 | const char *name; |
466 | struct i2c_adapter ddc; |
467 | struct device *dev; |
468 | |
469 | ssize_t (*transfer)(struct drm_dp_aux *aux, |
470 | struct drm_dp_aux_msg *msg); |
471 | }; |
472 | |
473 | ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, |
474 | void *buffer, size_t size); |
475 | ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, |
476 | void *buffer, size_t size); |
477 | |
478 | /** |
479 | * drm_dp_dpcd_readb() - read a single byte from the DPCD |
480 | * @aux: DisplayPort AUX channel |
481 | * @offset: address of the register to read |
482 | * @valuep: location where the value of the register will be stored |
483 | * |
484 | * Returns the number of bytes transferred (1) on success, or a negative |
485 | * error code on failure. |
486 | */ |
487 | static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux, |
488 | unsigned int offset, u8 *valuep) |
489 | { |
490 | return drm_dp_dpcd_read(aux, offset, valuep, 1); |
491 | } |
492 | |
493 | /** |
494 | * drm_dp_dpcd_writeb() - write a single byte to the DPCD |
495 | * @aux: DisplayPort AUX channel |
496 | * @offset: address of the register to write |
497 | * @value: value to write to the register |
498 | * |
499 | * Returns the number of bytes transferred (1) on success, or a negative |
500 | * error code on failure. |
501 | */ |
502 | static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux, |
503 | unsigned int offset, u8 value) |
504 | { |
505 | return drm_dp_dpcd_write(aux, offset, &value, 1); |
506 | } |
507 | |
508 | int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, |
509 | u8 status[DP_LINK_STATUS_SIZE]); |
510 | |
511 | /* |
512 | * DisplayPort link |
513 | */ |
514 | #define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0) |
515 | |
516 | struct drm_dp_link { |
517 | unsigned char revision; |
518 | unsigned int rate; |
519 | unsigned int num_lanes; |
520 | unsigned long capabilities; |
521 | }; |
522 | |
523 | int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link); |
524 | int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link); |
525 | int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link); |
526 | |
527 | int drm_dp_aux_register_i2c_bus(struct drm_dp_aux *aux); |
528 | void drm_dp_aux_unregister_i2c_bus(struct drm_dp_aux *aux); |
529 | |
530 | #endif /* _DRM_DP_HELPER_H_ */ |
531 | |