xref: /openbmc/linux/include/drm/drm_edid.h (revision e40573a4)
1 /*
2  * Copyright © 2007-2008 Intel Corporation
3  *   Jesse Barnes <jesse.barnes@intel.com>
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  */
23 #ifndef __DRM_EDID_H__
24 #define __DRM_EDID_H__
25 
26 #include <linux/types.h>
27 #include <linux/hdmi.h>
28 #include <drm/drm_mode.h>
29 
30 struct drm_device;
31 struct drm_edid;
32 struct i2c_adapter;
33 
34 #define EDID_LENGTH 128
35 #define DDC_ADDR 0x50
36 #define DDC_ADDR2 0x52 /* E-DDC 1.2 - where DisplayID can hide */
37 
38 #define CEA_EXT	    0x02
39 #define VTB_EXT	    0x10
40 #define DI_EXT	    0x40
41 #define LS_EXT	    0x50
42 #define MI_EXT	    0x60
43 #define DISPLAYID_EXT 0x70
44 
45 struct est_timings {
46 	u8 t1;
47 	u8 t2;
48 	u8 mfg_rsvd;
49 } __attribute__((packed));
50 
51 /* 00=16:10, 01=4:3, 10=5:4, 11=16:9 */
52 #define EDID_TIMING_ASPECT_SHIFT 6
53 #define EDID_TIMING_ASPECT_MASK  (0x3 << EDID_TIMING_ASPECT_SHIFT)
54 
55 /* need to add 60 */
56 #define EDID_TIMING_VFREQ_SHIFT  0
57 #define EDID_TIMING_VFREQ_MASK   (0x3f << EDID_TIMING_VFREQ_SHIFT)
58 
59 struct std_timing {
60 	u8 hsize; /* need to multiply by 8 then add 248 */
61 	u8 vfreq_aspect;
62 } __attribute__((packed));
63 
64 #define DRM_EDID_PT_HSYNC_POSITIVE (1 << 1)
65 #define DRM_EDID_PT_VSYNC_POSITIVE (1 << 2)
66 #define DRM_EDID_PT_SEPARATE_SYNC  (3 << 3)
67 #define DRM_EDID_PT_STEREO         (1 << 5)
68 #define DRM_EDID_PT_INTERLACED     (1 << 7)
69 
70 /* If detailed data is pixel timing */
71 struct detailed_pixel_timing {
72 	u8 hactive_lo;
73 	u8 hblank_lo;
74 	u8 hactive_hblank_hi;
75 	u8 vactive_lo;
76 	u8 vblank_lo;
77 	u8 vactive_vblank_hi;
78 	u8 hsync_offset_lo;
79 	u8 hsync_pulse_width_lo;
80 	u8 vsync_offset_pulse_width_lo;
81 	u8 hsync_vsync_offset_pulse_width_hi;
82 	u8 width_mm_lo;
83 	u8 height_mm_lo;
84 	u8 width_height_mm_hi;
85 	u8 hborder;
86 	u8 vborder;
87 	u8 misc;
88 } __attribute__((packed));
89 
90 /* If it's not pixel timing, it'll be one of the below */
91 struct detailed_data_string {
92 	u8 str[13];
93 } __attribute__((packed));
94 
95 #define DRM_EDID_DEFAULT_GTF_SUPPORT_FLAG   0x00
96 #define DRM_EDID_RANGE_LIMITS_ONLY_FLAG     0x01
97 #define DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG 0x02
98 #define DRM_EDID_CVT_SUPPORT_FLAG           0x04
99 
100 struct detailed_data_monitor_range {
101 	u8 min_vfreq;
102 	u8 max_vfreq;
103 	u8 min_hfreq_khz;
104 	u8 max_hfreq_khz;
105 	u8 pixel_clock_mhz; /* need to multiply by 10 */
106 	u8 flags;
107 	union {
108 		struct {
109 			u8 reserved;
110 			u8 hfreq_start_khz; /* need to multiply by 2 */
111 			u8 c; /* need to divide by 2 */
112 			__le16 m;
113 			u8 k;
114 			u8 j; /* need to divide by 2 */
115 		} __attribute__((packed)) gtf2;
116 		struct {
117 			u8 version;
118 			u8 data1; /* high 6 bits: extra clock resolution */
119 			u8 data2; /* plus low 2 of above: max hactive */
120 			u8 supported_aspects;
121 			u8 flags; /* preferred aspect and blanking support */
122 			u8 supported_scalings;
123 			u8 preferred_refresh;
124 		} __attribute__((packed)) cvt;
125 	} __attribute__((packed)) formula;
126 } __attribute__((packed));
127 
128 struct detailed_data_wpindex {
129 	u8 white_yx_lo; /* Lower 2 bits each */
130 	u8 white_x_hi;
131 	u8 white_y_hi;
132 	u8 gamma; /* need to divide by 100 then add 1 */
133 } __attribute__((packed));
134 
135 struct detailed_data_color_point {
136 	u8 windex1;
137 	u8 wpindex1[3];
138 	u8 windex2;
139 	u8 wpindex2[3];
140 } __attribute__((packed));
141 
142 struct cvt_timing {
143 	u8 code[3];
144 } __attribute__((packed));
145 
146 struct detailed_non_pixel {
147 	u8 pad1;
148 	u8 type; /* ff=serial, fe=string, fd=monitor range, fc=monitor name
149 		    fb=color point data, fa=standard timing data,
150 		    f9=undefined, f8=mfg. reserved */
151 	u8 pad2;
152 	union {
153 		struct detailed_data_string str;
154 		struct detailed_data_monitor_range range;
155 		struct detailed_data_wpindex color;
156 		struct std_timing timings[6];
157 		struct cvt_timing cvt[4];
158 	} __attribute__((packed)) data;
159 } __attribute__((packed));
160 
161 #define EDID_DETAIL_EST_TIMINGS 0xf7
162 #define EDID_DETAIL_CVT_3BYTE 0xf8
163 #define EDID_DETAIL_COLOR_MGMT_DATA 0xf9
164 #define EDID_DETAIL_STD_MODES 0xfa
165 #define EDID_DETAIL_MONITOR_CPDATA 0xfb
166 #define EDID_DETAIL_MONITOR_NAME 0xfc
167 #define EDID_DETAIL_MONITOR_RANGE 0xfd
168 #define EDID_DETAIL_MONITOR_STRING 0xfe
169 #define EDID_DETAIL_MONITOR_SERIAL 0xff
170 
171 struct detailed_timing {
172 	__le16 pixel_clock; /* need to multiply by 10 KHz */
173 	union {
174 		struct detailed_pixel_timing pixel_data;
175 		struct detailed_non_pixel other_data;
176 	} __attribute__((packed)) data;
177 } __attribute__((packed));
178 
179 #define DRM_EDID_INPUT_SERRATION_VSYNC (1 << 0)
180 #define DRM_EDID_INPUT_SYNC_ON_GREEN   (1 << 1)
181 #define DRM_EDID_INPUT_COMPOSITE_SYNC  (1 << 2)
182 #define DRM_EDID_INPUT_SEPARATE_SYNCS  (1 << 3)
183 #define DRM_EDID_INPUT_BLANK_TO_BLACK  (1 << 4)
184 #define DRM_EDID_INPUT_VIDEO_LEVEL     (3 << 5)
185 #define DRM_EDID_INPUT_DIGITAL         (1 << 7)
186 #define DRM_EDID_DIGITAL_DEPTH_MASK    (7 << 4) /* 1.4 */
187 #define DRM_EDID_DIGITAL_DEPTH_UNDEF   (0 << 4) /* 1.4 */
188 #define DRM_EDID_DIGITAL_DEPTH_6       (1 << 4) /* 1.4 */
189 #define DRM_EDID_DIGITAL_DEPTH_8       (2 << 4) /* 1.4 */
190 #define DRM_EDID_DIGITAL_DEPTH_10      (3 << 4) /* 1.4 */
191 #define DRM_EDID_DIGITAL_DEPTH_12      (4 << 4) /* 1.4 */
192 #define DRM_EDID_DIGITAL_DEPTH_14      (5 << 4) /* 1.4 */
193 #define DRM_EDID_DIGITAL_DEPTH_16      (6 << 4) /* 1.4 */
194 #define DRM_EDID_DIGITAL_DEPTH_RSVD    (7 << 4) /* 1.4 */
195 #define DRM_EDID_DIGITAL_TYPE_MASK     (7 << 0) /* 1.4 */
196 #define DRM_EDID_DIGITAL_TYPE_UNDEF    (0 << 0) /* 1.4 */
197 #define DRM_EDID_DIGITAL_TYPE_DVI      (1 << 0) /* 1.4 */
198 #define DRM_EDID_DIGITAL_TYPE_HDMI_A   (2 << 0) /* 1.4 */
199 #define DRM_EDID_DIGITAL_TYPE_HDMI_B   (3 << 0) /* 1.4 */
200 #define DRM_EDID_DIGITAL_TYPE_MDDI     (4 << 0) /* 1.4 */
201 #define DRM_EDID_DIGITAL_TYPE_DP       (5 << 0) /* 1.4 */
202 #define DRM_EDID_DIGITAL_DFP_1_X       (1 << 0) /* 1.3 */
203 
204 #define DRM_EDID_FEATURE_DEFAULT_GTF      (1 << 0)
205 #define DRM_EDID_FEATURE_PREFERRED_TIMING (1 << 1)
206 #define DRM_EDID_FEATURE_STANDARD_COLOR   (1 << 2)
207 /* If analog */
208 #define DRM_EDID_FEATURE_DISPLAY_TYPE     (3 << 3) /* 00=mono, 01=rgb, 10=non-rgb, 11=unknown */
209 /* If digital */
210 #define DRM_EDID_FEATURE_COLOR_MASK	  (3 << 3)
211 #define DRM_EDID_FEATURE_RGB		  (0 << 3)
212 #define DRM_EDID_FEATURE_RGB_YCRCB444	  (1 << 3)
213 #define DRM_EDID_FEATURE_RGB_YCRCB422	  (2 << 3)
214 #define DRM_EDID_FEATURE_RGB_YCRCB	  (3 << 3) /* both 4:4:4 and 4:2:2 */
215 
216 #define DRM_EDID_FEATURE_PM_ACTIVE_OFF    (1 << 5)
217 #define DRM_EDID_FEATURE_PM_SUSPEND       (1 << 6)
218 #define DRM_EDID_FEATURE_PM_STANDBY       (1 << 7)
219 
220 #define DRM_EDID_HDMI_DC_48               (1 << 6)
221 #define DRM_EDID_HDMI_DC_36               (1 << 5)
222 #define DRM_EDID_HDMI_DC_30               (1 << 4)
223 #define DRM_EDID_HDMI_DC_Y444             (1 << 3)
224 
225 /* YCBCR 420 deep color modes */
226 #define DRM_EDID_YCBCR420_DC_48		  (1 << 2)
227 #define DRM_EDID_YCBCR420_DC_36		  (1 << 1)
228 #define DRM_EDID_YCBCR420_DC_30		  (1 << 0)
229 #define DRM_EDID_YCBCR420_DC_MASK (DRM_EDID_YCBCR420_DC_48 | \
230 				    DRM_EDID_YCBCR420_DC_36 | \
231 				    DRM_EDID_YCBCR420_DC_30)
232 
233 /* HDMI 2.1 additional fields */
234 #define DRM_EDID_MAX_FRL_RATE_MASK		0xf0
235 #define DRM_EDID_FAPA_START_LOCATION		(1 << 0)
236 #define DRM_EDID_ALLM				(1 << 1)
237 #define DRM_EDID_FVA				(1 << 2)
238 
239 /* Deep Color specific */
240 #define DRM_EDID_DC_30BIT_420			(1 << 0)
241 #define DRM_EDID_DC_36BIT_420			(1 << 1)
242 #define DRM_EDID_DC_48BIT_420			(1 << 2)
243 
244 /* VRR specific */
245 #define DRM_EDID_CNMVRR				(1 << 3)
246 #define DRM_EDID_CINEMA_VRR			(1 << 4)
247 #define DRM_EDID_MDELTA				(1 << 5)
248 #define DRM_EDID_VRR_MAX_UPPER_MASK		0xc0
249 #define DRM_EDID_VRR_MAX_LOWER_MASK		0xff
250 #define DRM_EDID_VRR_MIN_MASK			0x3f
251 
252 /* DSC specific */
253 #define DRM_EDID_DSC_10BPC			(1 << 0)
254 #define DRM_EDID_DSC_12BPC			(1 << 1)
255 #define DRM_EDID_DSC_16BPC			(1 << 2)
256 #define DRM_EDID_DSC_ALL_BPP			(1 << 3)
257 #define DRM_EDID_DSC_NATIVE_420			(1 << 6)
258 #define DRM_EDID_DSC_1P2			(1 << 7)
259 #define DRM_EDID_DSC_MAX_FRL_RATE_MASK		0xf0
260 #define DRM_EDID_DSC_MAX_SLICES			0xf
261 #define DRM_EDID_DSC_TOTAL_CHUNK_KBYTES		0x3f
262 
263 /* ELD Header Block */
264 #define DRM_ELD_HEADER_BLOCK_SIZE	4
265 
266 #define DRM_ELD_VER			0
267 # define DRM_ELD_VER_SHIFT		3
268 # define DRM_ELD_VER_MASK		(0x1f << 3)
269 # define DRM_ELD_VER_CEA861D		(2 << 3) /* supports 861D or below */
270 # define DRM_ELD_VER_CANNED		(0x1f << 3)
271 
272 #define DRM_ELD_BASELINE_ELD_LEN	2	/* in dwords! */
273 
274 /* ELD Baseline Block for ELD_Ver == 2 */
275 #define DRM_ELD_CEA_EDID_VER_MNL	4
276 # define DRM_ELD_CEA_EDID_VER_SHIFT	5
277 # define DRM_ELD_CEA_EDID_VER_MASK	(7 << 5)
278 # define DRM_ELD_CEA_EDID_VER_NONE	(0 << 5)
279 # define DRM_ELD_CEA_EDID_VER_CEA861	(1 << 5)
280 # define DRM_ELD_CEA_EDID_VER_CEA861A	(2 << 5)
281 # define DRM_ELD_CEA_EDID_VER_CEA861BCD	(3 << 5)
282 # define DRM_ELD_MNL_SHIFT		0
283 # define DRM_ELD_MNL_MASK		(0x1f << 0)
284 
285 #define DRM_ELD_SAD_COUNT_CONN_TYPE	5
286 # define DRM_ELD_SAD_COUNT_SHIFT	4
287 # define DRM_ELD_SAD_COUNT_MASK		(0xf << 4)
288 # define DRM_ELD_CONN_TYPE_SHIFT	2
289 # define DRM_ELD_CONN_TYPE_MASK		(3 << 2)
290 # define DRM_ELD_CONN_TYPE_HDMI		(0 << 2)
291 # define DRM_ELD_CONN_TYPE_DP		(1 << 2)
292 # define DRM_ELD_SUPPORTS_AI		(1 << 1)
293 # define DRM_ELD_SUPPORTS_HDCP		(1 << 0)
294 
295 #define DRM_ELD_AUD_SYNCH_DELAY		6	/* in units of 2 ms */
296 # define DRM_ELD_AUD_SYNCH_DELAY_MAX	0xfa	/* 500 ms */
297 
298 #define DRM_ELD_SPEAKER			7
299 # define DRM_ELD_SPEAKER_MASK		0x7f
300 # define DRM_ELD_SPEAKER_RLRC		(1 << 6)
301 # define DRM_ELD_SPEAKER_FLRC		(1 << 5)
302 # define DRM_ELD_SPEAKER_RC		(1 << 4)
303 # define DRM_ELD_SPEAKER_RLR		(1 << 3)
304 # define DRM_ELD_SPEAKER_FC		(1 << 2)
305 # define DRM_ELD_SPEAKER_LFE		(1 << 1)
306 # define DRM_ELD_SPEAKER_FLR		(1 << 0)
307 
308 #define DRM_ELD_PORT_ID			8	/* offsets 8..15 inclusive */
309 # define DRM_ELD_PORT_ID_LEN		8
310 
311 #define DRM_ELD_MANUFACTURER_NAME0	16
312 #define DRM_ELD_MANUFACTURER_NAME1	17
313 
314 #define DRM_ELD_PRODUCT_CODE0		18
315 #define DRM_ELD_PRODUCT_CODE1		19
316 
317 #define DRM_ELD_MONITOR_NAME_STRING	20	/* offsets 20..(20+mnl-1) inclusive */
318 
319 #define DRM_ELD_CEA_SAD(mnl, sad)	(20 + (mnl) + 3 * (sad))
320 
321 struct edid {
322 	u8 header[8];
323 	/* Vendor & product info */
324 	u8 mfg_id[2];
325 	u8 prod_code[2];
326 	u32 serial; /* FIXME: byte order */
327 	u8 mfg_week;
328 	u8 mfg_year;
329 	/* EDID version */
330 	u8 version;
331 	u8 revision;
332 	/* Display info: */
333 	u8 input;
334 	u8 width_cm;
335 	u8 height_cm;
336 	u8 gamma;
337 	u8 features;
338 	/* Color characteristics */
339 	u8 red_green_lo;
340 	u8 blue_white_lo;
341 	u8 red_x;
342 	u8 red_y;
343 	u8 green_x;
344 	u8 green_y;
345 	u8 blue_x;
346 	u8 blue_y;
347 	u8 white_x;
348 	u8 white_y;
349 	/* Est. timings and mfg rsvd timings*/
350 	struct est_timings established_timings;
351 	/* Standard timings 1-8*/
352 	struct std_timing standard_timings[8];
353 	/* Detailing timings 1-4 */
354 	struct detailed_timing detailed_timings[4];
355 	/* Number of 128 byte ext. blocks */
356 	u8 extensions;
357 	/* Checksum */
358 	u8 checksum;
359 } __attribute__((packed));
360 
361 #define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
362 
363 /* Short Audio Descriptor */
364 struct cea_sad {
365 	u8 format;
366 	u8 channels; /* max number of channels - 1 */
367 	u8 freq;
368 	u8 byte2; /* meaning depends on format */
369 };
370 
371 struct drm_encoder;
372 struct drm_connector;
373 struct drm_connector_state;
374 struct drm_display_mode;
375 
376 int drm_edid_to_sad(const struct edid *edid, struct cea_sad **sads);
377 int drm_edid_to_speaker_allocation(const struct edid *edid, u8 **sadb);
378 int drm_av_sync_delay(struct drm_connector *connector,
379 		      const struct drm_display_mode *mode);
380 
381 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
382 struct edid *drm_load_edid_firmware(struct drm_connector *connector);
383 int __drm_set_edid_firmware_path(const char *path);
384 int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
385 #else
386 static inline struct edid *
387 drm_load_edid_firmware(struct drm_connector *connector)
388 {
389 	return ERR_PTR(-ENOENT);
390 }
391 #endif
392 
393 bool drm_edid_are_equal(const struct edid *edid1, const struct edid *edid2);
394 
395 int
396 drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
397 					 const struct drm_connector *connector,
398 					 const struct drm_display_mode *mode);
399 int
400 drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
401 					    const struct drm_connector *connector,
402 					    const struct drm_display_mode *mode);
403 
404 void
405 drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame,
406 				   const struct drm_connector *connector,
407 				   const struct drm_display_mode *mode,
408 				   enum hdmi_quantization_range rgb_quant_range);
409 
410 /**
411  * drm_eld_mnl - Get ELD monitor name length in bytes.
412  * @eld: pointer to an eld memory structure with mnl set
413  */
414 static inline int drm_eld_mnl(const uint8_t *eld)
415 {
416 	return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
417 }
418 
419 /**
420  * drm_eld_sad - Get ELD SAD structures.
421  * @eld: pointer to an eld memory structure with sad_count set
422  */
423 static inline const uint8_t *drm_eld_sad(const uint8_t *eld)
424 {
425 	unsigned int ver, mnl;
426 
427 	ver = (eld[DRM_ELD_VER] & DRM_ELD_VER_MASK) >> DRM_ELD_VER_SHIFT;
428 	if (ver != 2 && ver != 31)
429 		return NULL;
430 
431 	mnl = drm_eld_mnl(eld);
432 	if (mnl > 16)
433 		return NULL;
434 
435 	return eld + DRM_ELD_CEA_SAD(mnl, 0);
436 }
437 
438 /**
439  * drm_eld_sad_count - Get ELD SAD count.
440  * @eld: pointer to an eld memory structure with sad_count set
441  */
442 static inline int drm_eld_sad_count(const uint8_t *eld)
443 {
444 	return (eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_SAD_COUNT_MASK) >>
445 		DRM_ELD_SAD_COUNT_SHIFT;
446 }
447 
448 /**
449  * drm_eld_calc_baseline_block_size - Calculate baseline block size in bytes
450  * @eld: pointer to an eld memory structure with mnl and sad_count set
451  *
452  * This is a helper for determining the payload size of the baseline block, in
453  * bytes, for e.g. setting the Baseline_ELD_Len field in the ELD header block.
454  */
455 static inline int drm_eld_calc_baseline_block_size(const uint8_t *eld)
456 {
457 	return DRM_ELD_MONITOR_NAME_STRING - DRM_ELD_HEADER_BLOCK_SIZE +
458 		drm_eld_mnl(eld) + drm_eld_sad_count(eld) * 3;
459 }
460 
461 /**
462  * drm_eld_size - Get ELD size in bytes
463  * @eld: pointer to a complete eld memory structure
464  *
465  * The returned value does not include the vendor block. It's vendor specific,
466  * and comprises of the remaining bytes in the ELD memory buffer after
467  * drm_eld_size() bytes of header and baseline block.
468  *
469  * The returned value is guaranteed to be a multiple of 4.
470  */
471 static inline int drm_eld_size(const uint8_t *eld)
472 {
473 	return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
474 }
475 
476 /**
477  * drm_eld_get_spk_alloc - Get speaker allocation
478  * @eld: pointer to an ELD memory structure
479  *
480  * The returned value is the speakers mask. User has to use %DRM_ELD_SPEAKER
481  * field definitions to identify speakers.
482  */
483 static inline u8 drm_eld_get_spk_alloc(const uint8_t *eld)
484 {
485 	return eld[DRM_ELD_SPEAKER] & DRM_ELD_SPEAKER_MASK;
486 }
487 
488 /**
489  * drm_eld_get_conn_type - Get device type hdmi/dp connected
490  * @eld: pointer to an ELD memory structure
491  *
492  * The caller need to use %DRM_ELD_CONN_TYPE_HDMI or %DRM_ELD_CONN_TYPE_DP to
493  * identify the display type connected.
494  */
495 static inline u8 drm_eld_get_conn_type(const uint8_t *eld)
496 {
497 	return eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_CONN_TYPE_MASK;
498 }
499 
500 /**
501  * drm_edid_decode_mfg_id - Decode the manufacturer ID
502  * @mfg_id: The manufacturer ID
503  * @vend: A 4-byte buffer to store the 3-letter vendor string plus a '\0'
504  *	  termination
505  */
506 static inline const char *drm_edid_decode_mfg_id(u16 mfg_id, char vend[4])
507 {
508 	vend[0] = '@' + ((mfg_id >> 10) & 0x1f);
509 	vend[1] = '@' + ((mfg_id >> 5) & 0x1f);
510 	vend[2] = '@' + ((mfg_id >> 0) & 0x1f);
511 	vend[3] = '\0';
512 
513 	return vend;
514 }
515 
516 /**
517  * drm_edid_encode_panel_id - Encode an ID for matching against drm_edid_get_panel_id()
518  * @vend_chr_0: First character of the vendor string.
519  * @vend_chr_1: Second character of the vendor string.
520  * @vend_chr_2: Third character of the vendor string.
521  * @product_id: The 16-bit product ID.
522  *
523  * This is a macro so that it can be calculated at compile time and used
524  * as an initializer.
525  *
526  * For instance:
527  *   drm_edid_encode_panel_id('B', 'O', 'E', 0x2d08) => 0x09e52d08
528  *
529  * Return: a 32-bit ID per panel.
530  */
531 #define drm_edid_encode_panel_id(vend_chr_0, vend_chr_1, vend_chr_2, product_id) \
532 	((((u32)(vend_chr_0) - '@') & 0x1f) << 26 | \
533 	 (((u32)(vend_chr_1) - '@') & 0x1f) << 21 | \
534 	 (((u32)(vend_chr_2) - '@') & 0x1f) << 16 | \
535 	 ((product_id) & 0xffff))
536 
537 /**
538  * drm_edid_decode_panel_id - Decode a panel ID from drm_edid_encode_panel_id()
539  * @panel_id: The panel ID to decode.
540  * @vend: A 4-byte buffer to store the 3-letter vendor string plus a '\0'
541  *	  termination
542  * @product_id: The product ID will be returned here.
543  *
544  * For instance, after:
545  *   drm_edid_decode_panel_id(0x09e52d08, vend, &product_id)
546  * These will be true:
547  *   vend[0] = 'B'
548  *   vend[1] = 'O'
549  *   vend[2] = 'E'
550  *   vend[3] = '\0'
551  *   product_id = 0x2d08
552  */
553 static inline void drm_edid_decode_panel_id(u32 panel_id, char vend[4], u16 *product_id)
554 {
555 	*product_id = (u16)(panel_id & 0xffff);
556 	drm_edid_decode_mfg_id(panel_id >> 16, vend);
557 }
558 
559 bool drm_probe_ddc(struct i2c_adapter *adapter);
560 struct edid *drm_do_get_edid(struct drm_connector *connector,
561 	int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
562 			      size_t len),
563 	void *data);
564 struct edid *drm_get_edid(struct drm_connector *connector,
565 			  struct i2c_adapter *adapter);
566 u32 drm_edid_get_panel_id(struct i2c_adapter *adapter);
567 struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
568 				     struct i2c_adapter *adapter);
569 struct edid *drm_edid_duplicate(const struct edid *edid);
570 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);
571 int drm_add_override_edid_modes(struct drm_connector *connector);
572 
573 u8 drm_match_cea_mode(const struct drm_display_mode *to_match);
574 bool drm_detect_hdmi_monitor(const struct edid *edid);
575 bool drm_detect_monitor_audio(const struct edid *edid);
576 enum hdmi_quantization_range
577 drm_default_rgb_quant_range(const struct drm_display_mode *mode);
578 int drm_add_modes_noedid(struct drm_connector *connector,
579 			 int hdisplay, int vdisplay);
580 void drm_set_preferred_mode(struct drm_connector *connector,
581 			    int hpref, int vpref);
582 
583 int drm_edid_header_is_valid(const void *edid);
584 bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid,
585 			  bool *edid_corrupt);
586 bool drm_edid_is_valid(struct edid *edid);
587 void drm_edid_get_monitor_name(const struct edid *edid, char *name,
588 			       int buflen);
589 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
590 					   int hsize, int vsize, int fresh,
591 					   bool rb);
592 struct drm_display_mode *
593 drm_display_mode_from_cea_vic(struct drm_device *dev,
594 			      u8 video_code);
595 
596 /* Interface based on struct drm_edid */
597 const struct drm_edid *drm_edid_alloc(const void *edid, size_t size);
598 const struct drm_edid *drm_edid_dup(const struct drm_edid *drm_edid);
599 void drm_edid_free(const struct drm_edid *drm_edid);
600 const struct edid *drm_edid_raw(const struct drm_edid *drm_edid);
601 const struct drm_edid *drm_edid_read(struct drm_connector *connector);
602 const struct drm_edid *drm_edid_read_ddc(struct drm_connector *connector,
603 					 struct i2c_adapter *adapter);
604 const struct drm_edid *drm_edid_read_custom(struct drm_connector *connector,
605 					    int (*read_block)(void *context, u8 *buf, unsigned int block, size_t len),
606 					    void *context);
607 int drm_edid_connector_update(struct drm_connector *connector,
608 			      const struct drm_edid *edid);
609 const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid,
610 				  int ext_id, int *ext_index);
611 
612 #endif /* __DRM_EDID_H__ */
613