xref: /openbmc/linux/include/drm/drm_edid.h (revision 85d616dd)
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 i2c_adapter;
32 
33 #define EDID_LENGTH 128
34 #define DDC_ADDR 0x50
35 #define DDC_ADDR2 0x52 /* E-DDC 1.2 - where DisplayID can hide */
36 
37 #define CEA_EXT	    0x02
38 #define VTB_EXT	    0x10
39 #define DI_EXT	    0x40
40 #define LS_EXT	    0x50
41 #define MI_EXT	    0x60
42 #define DISPLAYID_EXT 0x70
43 
44 struct est_timings {
45 	u8 t1;
46 	u8 t2;
47 	u8 mfg_rsvd;
48 } __attribute__((packed));
49 
50 /* 00=16:10, 01=4:3, 10=5:4, 11=16:9 */
51 #define EDID_TIMING_ASPECT_SHIFT 6
52 #define EDID_TIMING_ASPECT_MASK  (0x3 << EDID_TIMING_ASPECT_SHIFT)
53 
54 /* need to add 60 */
55 #define EDID_TIMING_VFREQ_SHIFT  0
56 #define EDID_TIMING_VFREQ_MASK   (0x3f << EDID_TIMING_VFREQ_SHIFT)
57 
58 struct std_timing {
59 	u8 hsize; /* need to multiply by 8 then add 248 */
60 	u8 vfreq_aspect;
61 } __attribute__((packed));
62 
63 #define DRM_EDID_PT_HSYNC_POSITIVE (1 << 1)
64 #define DRM_EDID_PT_VSYNC_POSITIVE (1 << 2)
65 #define DRM_EDID_PT_SEPARATE_SYNC  (3 << 3)
66 #define DRM_EDID_PT_STEREO         (1 << 5)
67 #define DRM_EDID_PT_INTERLACED     (1 << 7)
68 
69 /* If detailed data is pixel timing */
70 struct detailed_pixel_timing {
71 	u8 hactive_lo;
72 	u8 hblank_lo;
73 	u8 hactive_hblank_hi;
74 	u8 vactive_lo;
75 	u8 vblank_lo;
76 	u8 vactive_vblank_hi;
77 	u8 hsync_offset_lo;
78 	u8 hsync_pulse_width_lo;
79 	u8 vsync_offset_pulse_width_lo;
80 	u8 hsync_vsync_offset_pulse_width_hi;
81 	u8 width_mm_lo;
82 	u8 height_mm_lo;
83 	u8 width_height_mm_hi;
84 	u8 hborder;
85 	u8 vborder;
86 	u8 misc;
87 } __attribute__((packed));
88 
89 /* If it's not pixel timing, it'll be one of the below */
90 struct detailed_data_string {
91 	u8 str[13];
92 } __attribute__((packed));
93 
94 #define DRM_EDID_DEFAULT_GTF_SUPPORT_FLAG   0x00
95 #define DRM_EDID_RANGE_LIMITS_ONLY_FLAG     0x01
96 #define DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG 0x02
97 #define DRM_EDID_CVT_SUPPORT_FLAG           0x04
98 
99 struct detailed_data_monitor_range {
100 	u8 min_vfreq;
101 	u8 max_vfreq;
102 	u8 min_hfreq_khz;
103 	u8 max_hfreq_khz;
104 	u8 pixel_clock_mhz; /* need to multiply by 10 */
105 	u8 flags;
106 	union {
107 		struct {
108 			u8 reserved;
109 			u8 hfreq_start_khz; /* need to multiply by 2 */
110 			u8 c; /* need to divide by 2 */
111 			__le16 m;
112 			u8 k;
113 			u8 j; /* need to divide by 2 */
114 		} __attribute__((packed)) gtf2;
115 		struct {
116 			u8 version;
117 			u8 data1; /* high 6 bits: extra clock resolution */
118 			u8 data2; /* plus low 2 of above: max hactive */
119 			u8 supported_aspects;
120 			u8 flags; /* preferred aspect and blanking support */
121 			u8 supported_scalings;
122 			u8 preferred_refresh;
123 		} __attribute__((packed)) cvt;
124 	} __attribute__((packed)) formula;
125 } __attribute__((packed));
126 
127 struct detailed_data_wpindex {
128 	u8 white_yx_lo; /* Lower 2 bits each */
129 	u8 white_x_hi;
130 	u8 white_y_hi;
131 	u8 gamma; /* need to divide by 100 then add 1 */
132 } __attribute__((packed));
133 
134 struct detailed_data_color_point {
135 	u8 windex1;
136 	u8 wpindex1[3];
137 	u8 windex2;
138 	u8 wpindex2[3];
139 } __attribute__((packed));
140 
141 struct cvt_timing {
142 	u8 code[3];
143 } __attribute__((packed));
144 
145 struct detailed_non_pixel {
146 	u8 pad1;
147 	u8 type; /* ff=serial, fe=string, fd=monitor range, fc=monitor name
148 		    fb=color point data, fa=standard timing data,
149 		    f9=undefined, f8=mfg. reserved */
150 	u8 pad2;
151 	union {
152 		struct detailed_data_string str;
153 		struct detailed_data_monitor_range range;
154 		struct detailed_data_wpindex color;
155 		struct std_timing timings[6];
156 		struct cvt_timing cvt[4];
157 	} __attribute__((packed)) data;
158 } __attribute__((packed));
159 
160 #define EDID_DETAIL_EST_TIMINGS 0xf7
161 #define EDID_DETAIL_CVT_3BYTE 0xf8
162 #define EDID_DETAIL_COLOR_MGMT_DATA 0xf9
163 #define EDID_DETAIL_STD_MODES 0xfa
164 #define EDID_DETAIL_MONITOR_CPDATA 0xfb
165 #define EDID_DETAIL_MONITOR_NAME 0xfc
166 #define EDID_DETAIL_MONITOR_RANGE 0xfd
167 #define EDID_DETAIL_MONITOR_STRING 0xfe
168 #define EDID_DETAIL_MONITOR_SERIAL 0xff
169 
170 struct detailed_timing {
171 	__le16 pixel_clock; /* need to multiply by 10 KHz */
172 	union {
173 		struct detailed_pixel_timing pixel_data;
174 		struct detailed_non_pixel other_data;
175 	} __attribute__((packed)) data;
176 } __attribute__((packed));
177 
178 #define DRM_EDID_INPUT_SERRATION_VSYNC (1 << 0)
179 #define DRM_EDID_INPUT_SYNC_ON_GREEN   (1 << 1)
180 #define DRM_EDID_INPUT_COMPOSITE_SYNC  (1 << 2)
181 #define DRM_EDID_INPUT_SEPARATE_SYNCS  (1 << 3)
182 #define DRM_EDID_INPUT_BLANK_TO_BLACK  (1 << 4)
183 #define DRM_EDID_INPUT_VIDEO_LEVEL     (3 << 5)
184 #define DRM_EDID_INPUT_DIGITAL         (1 << 7)
185 #define DRM_EDID_DIGITAL_DEPTH_MASK    (7 << 4) /* 1.4 */
186 #define DRM_EDID_DIGITAL_DEPTH_UNDEF   (0 << 4) /* 1.4 */
187 #define DRM_EDID_DIGITAL_DEPTH_6       (1 << 4) /* 1.4 */
188 #define DRM_EDID_DIGITAL_DEPTH_8       (2 << 4) /* 1.4 */
189 #define DRM_EDID_DIGITAL_DEPTH_10      (3 << 4) /* 1.4 */
190 #define DRM_EDID_DIGITAL_DEPTH_12      (4 << 4) /* 1.4 */
191 #define DRM_EDID_DIGITAL_DEPTH_14      (5 << 4) /* 1.4 */
192 #define DRM_EDID_DIGITAL_DEPTH_16      (6 << 4) /* 1.4 */
193 #define DRM_EDID_DIGITAL_DEPTH_RSVD    (7 << 4) /* 1.4 */
194 #define DRM_EDID_DIGITAL_TYPE_MASK     (7 << 0) /* 1.4 */
195 #define DRM_EDID_DIGITAL_TYPE_UNDEF    (0 << 0) /* 1.4 */
196 #define DRM_EDID_DIGITAL_TYPE_DVI      (1 << 0) /* 1.4 */
197 #define DRM_EDID_DIGITAL_TYPE_HDMI_A   (2 << 0) /* 1.4 */
198 #define DRM_EDID_DIGITAL_TYPE_HDMI_B   (3 << 0) /* 1.4 */
199 #define DRM_EDID_DIGITAL_TYPE_MDDI     (4 << 0) /* 1.4 */
200 #define DRM_EDID_DIGITAL_TYPE_DP       (5 << 0) /* 1.4 */
201 #define DRM_EDID_DIGITAL_DFP_1_X       (1 << 0) /* 1.3 */
202 
203 #define DRM_EDID_FEATURE_DEFAULT_GTF      (1 << 0)
204 #define DRM_EDID_FEATURE_PREFERRED_TIMING (1 << 1)
205 #define DRM_EDID_FEATURE_STANDARD_COLOR   (1 << 2)
206 /* If analog */
207 #define DRM_EDID_FEATURE_DISPLAY_TYPE     (3 << 3) /* 00=mono, 01=rgb, 10=non-rgb, 11=unknown */
208 /* If digital */
209 #define DRM_EDID_FEATURE_COLOR_MASK	  (3 << 3)
210 #define DRM_EDID_FEATURE_RGB		  (0 << 3)
211 #define DRM_EDID_FEATURE_RGB_YCRCB444	  (1 << 3)
212 #define DRM_EDID_FEATURE_RGB_YCRCB422	  (2 << 3)
213 #define DRM_EDID_FEATURE_RGB_YCRCB	  (3 << 3) /* both 4:4:4 and 4:2:2 */
214 
215 #define DRM_EDID_FEATURE_PM_ACTIVE_OFF    (1 << 5)
216 #define DRM_EDID_FEATURE_PM_SUSPEND       (1 << 6)
217 #define DRM_EDID_FEATURE_PM_STANDBY       (1 << 7)
218 
219 #define DRM_EDID_HDMI_DC_48               (1 << 6)
220 #define DRM_EDID_HDMI_DC_36               (1 << 5)
221 #define DRM_EDID_HDMI_DC_30               (1 << 4)
222 #define DRM_EDID_HDMI_DC_Y444             (1 << 3)
223 
224 /* YCBCR 420 deep color modes */
225 #define DRM_EDID_YCBCR420_DC_48		  (1 << 2)
226 #define DRM_EDID_YCBCR420_DC_36		  (1 << 1)
227 #define DRM_EDID_YCBCR420_DC_30		  (1 << 0)
228 #define DRM_EDID_YCBCR420_DC_MASK (DRM_EDID_YCBCR420_DC_48 | \
229 				    DRM_EDID_YCBCR420_DC_36 | \
230 				    DRM_EDID_YCBCR420_DC_30)
231 
232 /* HDMI 2.1 additional fields */
233 #define DRM_EDID_MAX_FRL_RATE_MASK		0xf0
234 #define DRM_EDID_FAPA_START_LOCATION		(1 << 0)
235 #define DRM_EDID_ALLM				(1 << 1)
236 #define DRM_EDID_FVA				(1 << 2)
237 
238 /* Deep Color specific */
239 #define DRM_EDID_DC_30BIT_420			(1 << 0)
240 #define DRM_EDID_DC_36BIT_420			(1 << 1)
241 #define DRM_EDID_DC_48BIT_420			(1 << 2)
242 
243 /* VRR specific */
244 #define DRM_EDID_CNMVRR				(1 << 3)
245 #define DRM_EDID_CINEMA_VRR			(1 << 4)
246 #define DRM_EDID_MDELTA				(1 << 5)
247 #define DRM_EDID_VRR_MAX_UPPER_MASK		0xc0
248 #define DRM_EDID_VRR_MAX_LOWER_MASK		0xff
249 #define DRM_EDID_VRR_MIN_MASK			0x3f
250 
251 /* DSC specific */
252 #define DRM_EDID_DSC_10BPC			(1 << 0)
253 #define DRM_EDID_DSC_12BPC			(1 << 1)
254 #define DRM_EDID_DSC_16BPC			(1 << 2)
255 #define DRM_EDID_DSC_ALL_BPP			(1 << 3)
256 #define DRM_EDID_DSC_NATIVE_420			(1 << 6)
257 #define DRM_EDID_DSC_1P2			(1 << 7)
258 #define DRM_EDID_DSC_MAX_FRL_RATE_MASK		0xf0
259 #define DRM_EDID_DSC_MAX_SLICES			0xf
260 #define DRM_EDID_DSC_TOTAL_CHUNK_KBYTES		0x3f
261 
262 /* ELD Header Block */
263 #define DRM_ELD_HEADER_BLOCK_SIZE	4
264 
265 #define DRM_ELD_VER			0
266 # define DRM_ELD_VER_SHIFT		3
267 # define DRM_ELD_VER_MASK		(0x1f << 3)
268 # define DRM_ELD_VER_CEA861D		(2 << 3) /* supports 861D or below */
269 # define DRM_ELD_VER_CANNED		(0x1f << 3)
270 
271 #define DRM_ELD_BASELINE_ELD_LEN	2	/* in dwords! */
272 
273 /* ELD Baseline Block for ELD_Ver == 2 */
274 #define DRM_ELD_CEA_EDID_VER_MNL	4
275 # define DRM_ELD_CEA_EDID_VER_SHIFT	5
276 # define DRM_ELD_CEA_EDID_VER_MASK	(7 << 5)
277 # define DRM_ELD_CEA_EDID_VER_NONE	(0 << 5)
278 # define DRM_ELD_CEA_EDID_VER_CEA861	(1 << 5)
279 # define DRM_ELD_CEA_EDID_VER_CEA861A	(2 << 5)
280 # define DRM_ELD_CEA_EDID_VER_CEA861BCD	(3 << 5)
281 # define DRM_ELD_MNL_SHIFT		0
282 # define DRM_ELD_MNL_MASK		(0x1f << 0)
283 
284 #define DRM_ELD_SAD_COUNT_CONN_TYPE	5
285 # define DRM_ELD_SAD_COUNT_SHIFT	4
286 # define DRM_ELD_SAD_COUNT_MASK		(0xf << 4)
287 # define DRM_ELD_CONN_TYPE_SHIFT	2
288 # define DRM_ELD_CONN_TYPE_MASK		(3 << 2)
289 # define DRM_ELD_CONN_TYPE_HDMI		(0 << 2)
290 # define DRM_ELD_CONN_TYPE_DP		(1 << 2)
291 # define DRM_ELD_SUPPORTS_AI		(1 << 1)
292 # define DRM_ELD_SUPPORTS_HDCP		(1 << 0)
293 
294 #define DRM_ELD_AUD_SYNCH_DELAY		6	/* in units of 2 ms */
295 # define DRM_ELD_AUD_SYNCH_DELAY_MAX	0xfa	/* 500 ms */
296 
297 #define DRM_ELD_SPEAKER			7
298 # define DRM_ELD_SPEAKER_MASK		0x7f
299 # define DRM_ELD_SPEAKER_RLRC		(1 << 6)
300 # define DRM_ELD_SPEAKER_FLRC		(1 << 5)
301 # define DRM_ELD_SPEAKER_RC		(1 << 4)
302 # define DRM_ELD_SPEAKER_RLR		(1 << 3)
303 # define DRM_ELD_SPEAKER_FC		(1 << 2)
304 # define DRM_ELD_SPEAKER_LFE		(1 << 1)
305 # define DRM_ELD_SPEAKER_FLR		(1 << 0)
306 
307 #define DRM_ELD_PORT_ID			8	/* offsets 8..15 inclusive */
308 # define DRM_ELD_PORT_ID_LEN		8
309 
310 #define DRM_ELD_MANUFACTURER_NAME0	16
311 #define DRM_ELD_MANUFACTURER_NAME1	17
312 
313 #define DRM_ELD_PRODUCT_CODE0		18
314 #define DRM_ELD_PRODUCT_CODE1		19
315 
316 #define DRM_ELD_MONITOR_NAME_STRING	20	/* offsets 20..(20+mnl-1) inclusive */
317 
318 #define DRM_ELD_CEA_SAD(mnl, sad)	(20 + (mnl) + 3 * (sad))
319 
320 struct edid {
321 	u8 header[8];
322 	/* Vendor & product info */
323 	u8 mfg_id[2];
324 	u8 prod_code[2];
325 	u32 serial; /* FIXME: byte order */
326 	u8 mfg_week;
327 	u8 mfg_year;
328 	/* EDID version */
329 	u8 version;
330 	u8 revision;
331 	/* Display info: */
332 	u8 input;
333 	u8 width_cm;
334 	u8 height_cm;
335 	u8 gamma;
336 	u8 features;
337 	/* Color characteristics */
338 	u8 red_green_lo;
339 	u8 blue_white_lo;
340 	u8 red_x;
341 	u8 red_y;
342 	u8 green_x;
343 	u8 green_y;
344 	u8 blue_x;
345 	u8 blue_y;
346 	u8 white_x;
347 	u8 white_y;
348 	/* Est. timings and mfg rsvd timings*/
349 	struct est_timings established_timings;
350 	/* Standard timings 1-8*/
351 	struct std_timing standard_timings[8];
352 	/* Detailing timings 1-4 */
353 	struct detailed_timing detailed_timings[4];
354 	/* Number of 128 byte ext. blocks */
355 	u8 extensions;
356 	/* Checksum */
357 	u8 checksum;
358 } __attribute__((packed));
359 
360 #define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
361 
362 /* Short Audio Descriptor */
363 struct cea_sad {
364 	u8 format;
365 	u8 channels; /* max number of channels - 1 */
366 	u8 freq;
367 	u8 byte2; /* meaning depends on format */
368 };
369 
370 struct drm_encoder;
371 struct drm_connector;
372 struct drm_connector_state;
373 struct drm_display_mode;
374 
375 int drm_edid_to_sad(const struct edid *edid, struct cea_sad **sads);
376 int drm_edid_to_speaker_allocation(const struct edid *edid, u8 **sadb);
377 int drm_av_sync_delay(struct drm_connector *connector,
378 		      const struct drm_display_mode *mode);
379 
380 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
381 struct edid *drm_load_edid_firmware(struct drm_connector *connector);
382 int __drm_set_edid_firmware_path(const char *path);
383 int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
384 #else
385 static inline struct edid *
386 drm_load_edid_firmware(struct drm_connector *connector)
387 {
388 	return ERR_PTR(-ENOENT);
389 }
390 #endif
391 
392 bool drm_edid_are_equal(const struct edid *edid1, const struct edid *edid2);
393 
394 int
395 drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
396 					 const struct drm_connector *connector,
397 					 const struct drm_display_mode *mode);
398 int
399 drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
400 					    const struct drm_connector *connector,
401 					    const struct drm_display_mode *mode);
402 
403 void
404 drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame,
405 				   const struct drm_connector *connector,
406 				   const struct drm_display_mode *mode,
407 				   enum hdmi_quantization_range rgb_quant_range);
408 
409 /**
410  * drm_eld_mnl - Get ELD monitor name length in bytes.
411  * @eld: pointer to an eld memory structure with mnl set
412  */
413 static inline int drm_eld_mnl(const uint8_t *eld)
414 {
415 	return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
416 }
417 
418 /**
419  * drm_eld_sad - Get ELD SAD structures.
420  * @eld: pointer to an eld memory structure with sad_count set
421  */
422 static inline const uint8_t *drm_eld_sad(const uint8_t *eld)
423 {
424 	unsigned int ver, mnl;
425 
426 	ver = (eld[DRM_ELD_VER] & DRM_ELD_VER_MASK) >> DRM_ELD_VER_SHIFT;
427 	if (ver != 2 && ver != 31)
428 		return NULL;
429 
430 	mnl = drm_eld_mnl(eld);
431 	if (mnl > 16)
432 		return NULL;
433 
434 	return eld + DRM_ELD_CEA_SAD(mnl, 0);
435 }
436 
437 /**
438  * drm_eld_sad_count - Get ELD SAD count.
439  * @eld: pointer to an eld memory structure with sad_count set
440  */
441 static inline int drm_eld_sad_count(const uint8_t *eld)
442 {
443 	return (eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_SAD_COUNT_MASK) >>
444 		DRM_ELD_SAD_COUNT_SHIFT;
445 }
446 
447 /**
448  * drm_eld_calc_baseline_block_size - Calculate baseline block size in bytes
449  * @eld: pointer to an eld memory structure with mnl and sad_count set
450  *
451  * This is a helper for determining the payload size of the baseline block, in
452  * bytes, for e.g. setting the Baseline_ELD_Len field in the ELD header block.
453  */
454 static inline int drm_eld_calc_baseline_block_size(const uint8_t *eld)
455 {
456 	return DRM_ELD_MONITOR_NAME_STRING - DRM_ELD_HEADER_BLOCK_SIZE +
457 		drm_eld_mnl(eld) + drm_eld_sad_count(eld) * 3;
458 }
459 
460 /**
461  * drm_eld_size - Get ELD size in bytes
462  * @eld: pointer to a complete eld memory structure
463  *
464  * The returned value does not include the vendor block. It's vendor specific,
465  * and comprises of the remaining bytes in the ELD memory buffer after
466  * drm_eld_size() bytes of header and baseline block.
467  *
468  * The returned value is guaranteed to be a multiple of 4.
469  */
470 static inline int drm_eld_size(const uint8_t *eld)
471 {
472 	return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
473 }
474 
475 /**
476  * drm_eld_get_spk_alloc - Get speaker allocation
477  * @eld: pointer to an ELD memory structure
478  *
479  * The returned value is the speakers mask. User has to use %DRM_ELD_SPEAKER
480  * field definitions to identify speakers.
481  */
482 static inline u8 drm_eld_get_spk_alloc(const uint8_t *eld)
483 {
484 	return eld[DRM_ELD_SPEAKER] & DRM_ELD_SPEAKER_MASK;
485 }
486 
487 /**
488  * drm_eld_get_conn_type - Get device type hdmi/dp connected
489  * @eld: pointer to an ELD memory structure
490  *
491  * The caller need to use %DRM_ELD_CONN_TYPE_HDMI or %DRM_ELD_CONN_TYPE_DP to
492  * identify the display type connected.
493  */
494 static inline u8 drm_eld_get_conn_type(const uint8_t *eld)
495 {
496 	return eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_CONN_TYPE_MASK;
497 }
498 
499 /**
500  * drm_edid_encode_panel_id - Encode an ID for matching against drm_edid_get_panel_id()
501  * @vend_chr_0: First character of the vendor string.
502  * @vend_chr_1: Second character of the vendor string.
503  * @vend_chr_2: Third character of the vendor string.
504  * @product_id: The 16-bit product ID.
505  *
506  * This is a macro so that it can be calculated at compile time and used
507  * as an initializer.
508  *
509  * For instance:
510  *   drm_edid_encode_panel_id('B', 'O', 'E', 0x2d08) => 0x09e52d08
511  *
512  * Return: a 32-bit ID per panel.
513  */
514 #define drm_edid_encode_panel_id(vend_chr_0, vend_chr_1, vend_chr_2, product_id) \
515 	((((u32)(vend_chr_0) - '@') & 0x1f) << 26 | \
516 	 (((u32)(vend_chr_1) - '@') & 0x1f) << 21 | \
517 	 (((u32)(vend_chr_2) - '@') & 0x1f) << 16 | \
518 	 ((product_id) & 0xffff))
519 
520 /**
521  * drm_edid_decode_panel_id - Decode a panel ID from drm_edid_encode_panel_id()
522  * @panel_id: The panel ID to decode.
523  * @vend: A 4-byte buffer to store the 3-letter vendor string plus a '\0'
524  *	  termination
525  * @product_id: The product ID will be returned here.
526  *
527  * For instance, after:
528  *   drm_edid_decode_panel_id(0x09e52d08, vend, &product_id)
529  * These will be true:
530  *   vend[0] = 'B'
531  *   vend[1] = 'O'
532  *   vend[2] = 'E'
533  *   vend[3] = '\0'
534  *   product_id = 0x2d08
535  */
536 static inline void drm_edid_decode_panel_id(u32 panel_id, char vend[4], u16 *product_id)
537 {
538 	*product_id = (u16)(panel_id & 0xffff);
539 	vend[0] = '@' + ((panel_id >> 26) & 0x1f);
540 	vend[1] = '@' + ((panel_id >> 21) & 0x1f);
541 	vend[2] = '@' + ((panel_id >> 16) & 0x1f);
542 	vend[3] = '\0';
543 }
544 
545 bool drm_probe_ddc(struct i2c_adapter *adapter);
546 struct edid *drm_do_get_edid(struct drm_connector *connector,
547 	int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
548 			      size_t len),
549 	void *data);
550 struct edid *drm_get_edid(struct drm_connector *connector,
551 			  struct i2c_adapter *adapter);
552 u32 drm_edid_get_panel_id(struct i2c_adapter *adapter);
553 struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
554 				     struct i2c_adapter *adapter);
555 struct edid *drm_edid_duplicate(const struct edid *edid);
556 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);
557 int drm_add_override_edid_modes(struct drm_connector *connector);
558 
559 u8 drm_match_cea_mode(const struct drm_display_mode *to_match);
560 bool drm_detect_hdmi_monitor(const struct edid *edid);
561 bool drm_detect_monitor_audio(const struct edid *edid);
562 enum hdmi_quantization_range
563 drm_default_rgb_quant_range(const struct drm_display_mode *mode);
564 int drm_add_modes_noedid(struct drm_connector *connector,
565 			 int hdisplay, int vdisplay);
566 void drm_set_preferred_mode(struct drm_connector *connector,
567 			    int hpref, int vpref);
568 
569 int drm_edid_header_is_valid(const void *edid);
570 bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid,
571 			  bool *edid_corrupt);
572 bool drm_edid_is_valid(struct edid *edid);
573 void drm_edid_get_monitor_name(const struct edid *edid, char *name,
574 			       int buflen);
575 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
576 					   int hsize, int vsize, int fresh,
577 					   bool rb);
578 struct drm_display_mode *
579 drm_display_mode_from_cea_vic(struct drm_device *dev,
580 			      u8 video_code);
581 const u8 *drm_find_edid_extension(const struct edid *edid,
582 				  int ext_id, int *ext_index);
583 
584 
585 #endif /* __DRM_EDID_H__ */
586