2 * Copyright (c) 2012 The Chromium OS Authors.
5 * Petr Stetiar <ynezz@true.cz>
7 * SPDX-License-Identifier: GPL-2.0+
9 * Contains stolen code from ddcprobe project which is:
10 * Copyright (C) Nalin Dahyabhai <bigfun@pobox.com>
16 #include <linux/types.h>
18 /* Size of the EDID data */
20 #define EDID_EXT_SIZE 256
22 /* OUI of HDMI vendor specific data block */
23 #define HDMI_IEEE_OUI 0x000c03
25 #define GET_BIT(_x, _pos) \
26 (((_x) >> (_pos)) & 1)
27 #define GET_BITS(_x, _pos_msb, _pos_lsb) \
28 (((_x) >> (_pos_lsb)) & ((1 << ((_pos_msb) - (_pos_lsb) + 1)) - 1))
30 /* Aspect ratios used in EDID info. */
38 /* Detailed timing information used in EDID v1.x */
39 struct edid_detailed_timing {
40 unsigned char pixel_clock[2];
41 #define EDID_DETAILED_TIMING_PIXEL_CLOCK(_x) \
42 (((((uint32_t)(_x).pixel_clock[1]) << 8) + \
43 (_x).pixel_clock[0]) * 10000)
44 unsigned char horizontal_active;
45 unsigned char horizontal_blanking;
46 unsigned char horizontal_active_blanking_hi;
47 #define EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(_x) \
48 ((GET_BITS((_x).horizontal_active_blanking_hi, 7, 4) << 8) + \
49 (_x).horizontal_active)
50 #define EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(_x) \
51 ((GET_BITS((_x).horizontal_active_blanking_hi, 3, 0) << 8) + \
52 (_x).horizontal_blanking)
53 unsigned char vertical_active;
54 unsigned char vertical_blanking;
55 unsigned char vertical_active_blanking_hi;
56 #define EDID_DETAILED_TIMING_VERTICAL_ACTIVE(_x) \
57 ((GET_BITS((_x).vertical_active_blanking_hi, 7, 4) << 8) + \
59 #define EDID_DETAILED_TIMING_VERTICAL_BLANKING(_x) \
60 ((GET_BITS((_x).vertical_active_blanking_hi, 3, 0) << 8) + \
61 (_x).vertical_blanking)
62 unsigned char hsync_offset;
63 unsigned char hsync_pulse_width;
64 unsigned char vsync_offset_pulse_width;
65 unsigned char hsync_vsync_offset_pulse_width_hi;
66 #define EDID_DETAILED_TIMING_HSYNC_OFFSET(_x) \
67 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 7, 6) << 8) + \
69 #define EDID_DETAILED_TIMING_HSYNC_PULSE_WIDTH(_x) \
70 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 5, 4) << 8) + \
71 (_x).hsync_pulse_width)
72 #define EDID_DETAILED_TIMING_VSYNC_OFFSET(_x) \
73 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 3, 2) << 4) + \
74 GET_BITS((_x).vsync_offset_pulse_width, 7, 4))
75 #define EDID_DETAILED_TIMING_VSYNC_PULSE_WIDTH(_x) \
76 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 1, 0) << 4) + \
77 GET_BITS((_x).vsync_offset_pulse_width, 3, 0))
78 unsigned char himage_size;
79 unsigned char vimage_size;
80 unsigned char himage_vimage_size_hi;
81 #define EDID_DETAILED_TIMING_HIMAGE_SIZE(_x) \
82 ((GET_BITS((_x).himage_vimage_size_hi, 7, 4) << 8) + (_x).himage_size)
83 #define EDID_DETAILED_TIMING_VIMAGE_SIZE(_x) \
84 ((GET_BITS((_x).himage_vimage_size_hi, 3, 0) << 8) + (_x).vimage_size)
85 unsigned char hborder;
86 unsigned char vborder;
88 #define EDID_DETAILED_TIMING_FLAG_INTERLACED(_x) \
89 GET_BIT((_x).flags, 7)
90 #define EDID_DETAILED_TIMING_FLAG_STEREO(_x) \
91 GET_BITS((_x).flags, 6, 5)
92 #define EDID_DETAILED_TIMING_FLAG_DIGITAL_COMPOSITE(_x) \
93 GET_BITS((_x).flags, 4, 3)
94 #define EDID_DETAILED_TIMING_FLAG_POLARITY(_x) \
95 GET_BITS((_x).flags, 2, 1)
96 #define EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(_x) \
97 GET_BIT((_x).flags, 2)
98 #define EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(_x) \
99 GET_BIT((_x).flags, 1)
100 #define EDID_DETAILED_TIMING_FLAG_INTERLEAVED(_x) \
101 GET_BIT((_x).flags, 0)
102 } __attribute__ ((__packed__));
104 enum edid_monitor_descriptor_types {
105 EDID_MONITOR_DESCRIPTOR_SERIAL = 0xff,
106 EDID_MONITOR_DESCRIPTOR_ASCII = 0xfe,
107 EDID_MONITOR_DESCRIPTOR_RANGE = 0xfd,
108 EDID_MONITOR_DESCRIPTOR_NAME = 0xfc,
111 struct edid_monitor_descriptor {
112 uint16_t zero_flag_1;
113 unsigned char zero_flag_2;
115 unsigned char zero_flag_3;
119 unsigned char vertical_min;
120 unsigned char vertical_max;
121 unsigned char horizontal_min;
122 unsigned char horizontal_max;
123 unsigned char pixel_clock_max;
124 unsigned char gtf_data[8];
127 } __attribute__ ((__packed__));
130 unsigned char header[8];
131 unsigned char manufacturer_name[2];
132 #define EDID1_INFO_MANUFACTURER_NAME_ZERO(_x) \
133 GET_BIT(((_x).manufacturer_name[0]), 7)
134 #define EDID1_INFO_MANUFACTURER_NAME_CHAR1(_x) \
135 GET_BITS(((_x).manufacturer_name[0]), 6, 2)
136 #define EDID1_INFO_MANUFACTURER_NAME_CHAR2(_x) \
137 ((GET_BITS(((_x).manufacturer_name[0]), 1, 0) << 3) + \
138 GET_BITS(((_x).manufacturer_name[1]), 7, 5))
139 #define EDID1_INFO_MANUFACTURER_NAME_CHAR3(_x) \
140 GET_BITS(((_x).manufacturer_name[1]), 4, 0)
141 unsigned char product_code[2];
142 #define EDID1_INFO_PRODUCT_CODE(_x) \
143 (((uint16_t)(_x).product_code[1] << 8) + (_x).product_code[0])
144 unsigned char serial_number[4];
145 #define EDID1_INFO_SERIAL_NUMBER(_x) \
146 (((uint32_t)(_x).serial_number[3] << 24) + \
147 ((_x).serial_number[2] << 16) + ((_x).serial_number[1] << 8) + \
148 (_x).serial_number[0])
151 unsigned char version;
152 unsigned char revision;
153 unsigned char video_input_definition;
154 #define EDID1_INFO_VIDEO_INPUT_DIGITAL(_x) \
155 GET_BIT(((_x).video_input_definition), 7)
156 #define EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(_x) \
157 GET_BITS(((_x).video_input_definition), 6, 5)
158 #define EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(_x) \
159 GET_BIT(((_x).video_input_definition), 4)
160 #define EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(_x) \
161 GET_BIT(((_x).video_input_definition), 3)
162 #define EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(_x) \
163 GET_BIT(((_x).video_input_definition), 2)
164 #define EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(_x) \
165 GET_BIT(((_x).video_input_definition), 1)
166 #define EDID1_INFO_VIDEO_INPUT_SERRATION_V(_x) \
167 GET_BIT(((_x).video_input_definition), 0)
168 unsigned char max_size_horizontal;
169 unsigned char max_size_vertical;
171 unsigned char feature_support;
172 #define EDID1_INFO_FEATURE_STANDBY(_x) \
173 GET_BIT(((_x).feature_support), 7)
174 #define EDID1_INFO_FEATURE_SUSPEND(_x) \
175 GET_BIT(((_x).feature_support), 6)
176 #define EDID1_INFO_FEATURE_ACTIVE_OFF(_x) \
177 GET_BIT(((_x).feature_support), 5)
178 #define EDID1_INFO_FEATURE_DISPLAY_TYPE(_x) \
179 GET_BITS(((_x).feature_support), 4, 3)
180 #define EDID1_INFO_FEATURE_RGB(_x) \
181 GET_BIT(((_x).feature_support), 2)
182 #define EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(_x) \
183 GET_BIT(((_x).feature_support), 1)
184 #define EDID1_INFO_FEATURE_DEFAULT_GTF_SUPPORT(_x) \
185 GET_BIT(((_x).feature_support), 0)
186 unsigned char color_characteristics[10];
187 unsigned char established_timings[3];
188 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_70(_x) \
189 GET_BIT(((_x).established_timings[0]), 7)
190 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_88(_x) \
191 GET_BIT(((_x).established_timings[0]), 6)
192 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_60(_x) \
193 GET_BIT(((_x).established_timings[0]), 5)
194 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_67(_x) \
195 GET_BIT(((_x).established_timings[0]), 4)
196 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_72(_x) \
197 GET_BIT(((_x).established_timings[0]), 3)
198 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_75(_x) \
199 GET_BIT(((_x).established_timings[0]), 2)
200 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_56(_x) \
201 GET_BIT(((_x).established_timings[0]), 1)
202 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_60(_x) \
203 GET_BIT(((_x).established_timings[0]), 0)
204 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_72(_x) \
205 GET_BIT(((_x).established_timings[1]), 7)
206 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_75(_x) \
207 GET_BIT(((_x).established_timings[1]), 6)
208 #define EDID1_INFO_ESTABLISHED_TIMING_832X624_75(_x) \
209 GET_BIT(((_x).established_timings[1]), 5)
210 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(_x) \
211 GET_BIT(((_x).established_timings[1]), 4)
212 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(_x) \
213 GET_BIT(((_x).established_timings[1]), 3)
214 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(_x) \
215 GET_BIT(((_x).established_timings[1]), 2)
216 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(_x) \
217 GET_BIT(((_x).established_timings[1]), 1)
218 #define EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(_x) \
219 GET_BIT(((_x).established_timings[1]), 0)
220 #define EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(_x) \
221 GET_BIT(((_x).established_timings[2]), 7)
223 unsigned char xresolution;
224 unsigned char aspect_vfreq;
225 } __attribute__((__packed__)) standard_timings[8];
226 #define EDID1_INFO_STANDARD_TIMING_XRESOLUTION(_x, _i) \
227 (((_x).standard_timings[_i]).xresolution)
228 #define EDID1_INFO_STANDARD_TIMING_ASPECT(_x, _i) \
229 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 7, 6)
230 #define EDID1_INFO_STANDARD_TIMING_VFREQ(_x, _i) \
231 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 5, 0)
233 unsigned char timing[72];
234 struct edid_monitor_descriptor descriptor[4];
236 unsigned char extension_flag;
237 unsigned char checksum;
238 } __attribute__ ((__packed__));
240 enum edid_cea861_db_types {
241 EDID_CEA861_DB_AUDIO = 0x01,
242 EDID_CEA861_DB_VIDEO = 0x02,
243 EDID_CEA861_DB_VENDOR = 0x03,
244 EDID_CEA861_DB_SPEAKER = 0x04,
247 struct edid_cea861_info {
248 unsigned char extension_tag;
249 #define EDID_CEA861_EXTENSION_TAG 0x02
250 unsigned char revision;
251 unsigned char dtd_offset;
252 unsigned char dtd_count;
253 #define EDID_CEA861_SUPPORTS_UNDERSCAN(_x) \
254 GET_BIT(((_x).dtd_count), 7)
255 #define EDID_CEA861_SUPPORTS_BASIC_AUDIO(_x) \
256 GET_BIT(((_x).dtd_count), 6)
257 #define EDID_CEA861_SUPPORTS_YUV444(_x) \
258 GET_BIT(((_x).dtd_count), 5)
259 #define EDID_CEA861_SUPPORTS_YUV422(_x) \
260 GET_BIT(((_x).dtd_count), 4)
261 #define EDID_CEA861_DTD_COUNT(_x) \
262 GET_BITS(((_x).dtd_count), 3, 0)
263 unsigned char data[124];
264 #define EDID_CEA861_DB_TYPE(_x, offset) \
265 GET_BITS((_x).data[offset], 7, 5)
266 #define EDID_CEA861_DB_LEN(_x, offset) \
267 GET_BITS((_x).data[offset], 4, 0)
268 } __attribute__ ((__packed__));
271 * Print the EDID info.
273 * @param edid_info The EDID info to be printed
275 void edid_print_info(struct edid1_info *edid_info);
278 * Check the EDID info.
280 * @param info The EDID info to be checked
281 * @return 0 on valid, or -1 on invalid
283 int edid_check_info(struct edid1_info *info);
286 * Check checksum of a 128 bytes EDID data block
288 * @param edid_block EDID block data
290 * @return 0 on success, or a negative errno on error
292 int edid_check_checksum(u8 *edid_block);
295 * Get the horizontal and vertical rate ranges of the monitor.
297 * @param edid The EDID info
298 * @param hmin Returns the minimum horizontal rate
299 * @param hmax Returns the maxium horizontal rate
300 * @param vmin Returns the minimum vertical rate
301 * @param vmax Returns the maxium vertical rate
302 * @return 0 on success, or -1 on error
304 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
305 unsigned int *hmax, unsigned int *vmin,
308 struct display_timing;
311 * edid_get_timing() - Get basic digital display parameters
313 * @param buf Buffer containing EDID data
314 * @param buf_size Size of buffer in bytes
315 * @param timing Place to put preferring timing information
316 * @param panel_bits_per_colourp Place to put the number of bits per
317 * colour supported by the panel. This will be set to
318 * -1 if not available
319 * @return 0 if timings are OK, -ve on error
321 int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing,
322 int *panel_bits_per_colourp);
324 #endif /* __EDID_H_ */