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 #define GET_BIT(_x, _pos) \
19 (((_x) >> (_pos)) & 1)
20 #define GET_BITS(_x, _pos_msb, _pos_lsb) \
21 (((_x) >> (_pos_lsb)) & ((1 << ((_pos_msb) - (_pos_lsb) + 1)) - 1))
23 /* Aspect ratios used in EDID info. */
31 /* Detailed timing information used in EDID v1.x */
32 struct edid_detailed_timing {
33 unsigned char pixel_clock[2];
34 #define EDID_DETAILED_TIMING_PIXEL_CLOCK(_x) \
35 (((((uint32_t)(_x).pixel_clock[1]) << 8) + \
36 (_x).pixel_clock[0]) * 10000)
37 unsigned char horizontal_active;
38 unsigned char horizontal_blanking;
39 unsigned char horizontal_active_blanking_hi;
40 #define EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(_x) \
41 ((GET_BITS((_x).horizontal_active_blanking_hi, 7, 4) << 8) + \
42 (_x).horizontal_active)
43 #define EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(_x) \
44 ((GET_BITS((_x).horizontal_active_blanking_hi, 3, 0) << 8) + \
45 (_x).horizontal_blanking)
46 unsigned char vertical_active;
47 unsigned char vertical_blanking;
48 unsigned char vertical_active_blanking_hi;
49 #define EDID_DETAILED_TIMING_VERTICAL_ACTIVE(_x) \
50 ((GET_BITS((_x).vertical_active_blanking_hi, 7, 4) << 8) + \
52 #define EDID_DETAILED_TIMING_VERTICAL_BLANKING(_x) \
53 ((GET_BITS((_x).vertical_active_blanking_hi, 3, 0) << 8) + \
54 (_x).vertical_blanking)
55 unsigned char hsync_offset;
56 unsigned char hsync_pulse_width;
57 unsigned char vsync_offset_pulse_width;
58 unsigned char hsync_vsync_offset_pulse_width_hi;
59 #define EDID_DETAILED_TIMING_HSYNC_OFFSET(_x) \
60 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 7, 6) << 8) + \
62 #define EDID_DETAILED_TIMING_HSYNC_PULSE_WIDTH(_x) \
63 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 5, 4) << 8) + \
64 (_x).hsync_pulse_width)
65 #define EDID_DETAILED_TIMING_VSYNC_OFFSET(_x) \
66 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 3, 2) << 4) + \
67 GET_BITS((_x).vsync_offset_pulse_width, 7, 4))
68 #define EDID_DETAILED_TIMING_VSYNC_PULSE_WIDTH(_x) \
69 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 1, 0) << 4) + \
70 GET_BITS((_x).vsync_offset_pulse_width, 3, 0))
71 unsigned char himage_size;
72 unsigned char vimage_size;
73 unsigned char himage_vimage_size_hi;
74 #define EDID_DETAILED_TIMING_HIMAGE_SIZE(_x) \
75 ((GET_BITS((_x).himage_vimage_size_hi, 7, 4) << 8) + (_x).himage_size)
76 #define EDID_DETAILED_TIMING_VIMAGE_SIZE(_x) \
77 ((GET_BITS((_x).himage_vimage_size_hi, 3, 0) << 8) + (_x).vimage_size)
78 unsigned char hborder;
79 unsigned char vborder;
81 #define EDID_DETAILED_TIMING_FLAG_INTERLACED(_x) \
82 GET_BIT((_x).flags, 7)
83 #define EDID_DETAILED_TIMING_FLAG_STEREO(_x) \
84 GET_BITS((_x).flags, 6, 5)
85 #define EDID_DETAILED_TIMING_FLAG_DIGITAL_COMPOSITE(_x) \
86 GET_BITS((_x).flags, 4, 3)
87 #define EDID_DETAILED_TIMING_FLAG_POLARITY(_x) \
88 GET_BITS((_x).flags, 2, 1)
89 #define EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(_x) \
90 GET_BIT((_x).flags, 2)
91 #define EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(_x) \
92 GET_BIT((_x).flags, 1)
93 #define EDID_DETAILED_TIMING_FLAG_INTERLEAVED(_x) \
94 GET_BIT((_x).flags, 0)
95 } __attribute__ ((__packed__));
97 enum edid_monitor_descriptor_types {
98 EDID_MONITOR_DESCRIPTOR_SERIAL = 0xff,
99 EDID_MONITOR_DESCRIPTOR_ASCII = 0xfe,
100 EDID_MONITOR_DESCRIPTOR_RANGE = 0xfd,
101 EDID_MONITOR_DESCRIPTOR_NAME = 0xfc,
104 struct edid_monitor_descriptor {
105 uint16_t zero_flag_1;
106 unsigned char zero_flag_2;
108 unsigned char zero_flag_3;
112 unsigned char vertical_min;
113 unsigned char vertical_max;
114 unsigned char horizontal_min;
115 unsigned char horizontal_max;
116 unsigned char pixel_clock_max;
117 unsigned char gtf_data[8];
120 } __attribute__ ((__packed__));
123 unsigned char header[8];
124 unsigned char manufacturer_name[2];
125 #define EDID1_INFO_MANUFACTURER_NAME_ZERO(_x) \
126 GET_BIT(((_x).manufacturer_name[0]), 7)
127 #define EDID1_INFO_MANUFACTURER_NAME_CHAR1(_x) \
128 GET_BITS(((_x).manufacturer_name[0]), 6, 2)
129 #define EDID1_INFO_MANUFACTURER_NAME_CHAR2(_x) \
130 ((GET_BITS(((_x).manufacturer_name[0]), 1, 0) << 3) + \
131 GET_BITS(((_x).manufacturer_name[1]), 7, 5))
132 #define EDID1_INFO_MANUFACTURER_NAME_CHAR3(_x) \
133 GET_BITS(((_x).manufacturer_name[1]), 4, 0)
134 unsigned char product_code[2];
135 #define EDID1_INFO_PRODUCT_CODE(_x) \
136 (((uint16_t)(_x).product_code[1] << 8) + (_x).product_code[0])
137 unsigned char serial_number[4];
138 #define EDID1_INFO_SERIAL_NUMBER(_x) \
139 (((uint32_t)(_x).serial_number[3] << 24) + \
140 ((_x).serial_number[2] << 16) + ((_x).serial_number[1] << 8) + \
141 (_x).serial_number[0])
144 unsigned char version;
145 unsigned char revision;
146 unsigned char video_input_definition;
147 #define EDID1_INFO_VIDEO_INPUT_DIGITAL(_x) \
148 GET_BIT(((_x).video_input_definition), 7)
149 #define EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(_x) \
150 GET_BITS(((_x).video_input_definition), 6, 5)
151 #define EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(_x) \
152 GET_BIT(((_x).video_input_definition), 4)
153 #define EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(_x) \
154 GET_BIT(((_x).video_input_definition), 3)
155 #define EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(_x) \
156 GET_BIT(((_x).video_input_definition), 2)
157 #define EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(_x) \
158 GET_BIT(((_x).video_input_definition), 1)
159 #define EDID1_INFO_VIDEO_INPUT_SERRATION_V(_x) \
160 GET_BIT(((_x).video_input_definition), 0)
161 unsigned char max_size_horizontal;
162 unsigned char max_size_vertical;
164 unsigned char feature_support;
165 #define EDID1_INFO_FEATURE_STANDBY(_x) \
166 GET_BIT(((_x).feature_support), 7)
167 #define EDID1_INFO_FEATURE_SUSPEND(_x) \
168 GET_BIT(((_x).feature_support), 6)
169 #define EDID1_INFO_FEATURE_ACTIVE_OFF(_x) \
170 GET_BIT(((_x).feature_support), 5)
171 #define EDID1_INFO_FEATURE_DISPLAY_TYPE(_x) \
172 GET_BITS(((_x).feature_support), 4, 3)
173 #define EDID1_INFO_FEATURE_RGB(_x) \
174 GET_BIT(((_x).feature_support), 2)
175 #define EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(_x) \
176 GET_BIT(((_x).feature_support), 1)
177 #define EDID1_INFO_FEATURE_DEFAULT_GTF_SUPPORT(_x) \
178 GET_BIT(((_x).feature_support), 0)
179 unsigned char color_characteristics[10];
180 unsigned char established_timings[3];
181 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_70(_x) \
182 GET_BIT(((_x).established_timings[0]), 7)
183 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_88(_x) \
184 GET_BIT(((_x).established_timings[0]), 6)
185 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_60(_x) \
186 GET_BIT(((_x).established_timings[0]), 5)
187 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_67(_x) \
188 GET_BIT(((_x).established_timings[0]), 4)
189 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_72(_x) \
190 GET_BIT(((_x).established_timings[0]), 3)
191 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_75(_x) \
192 GET_BIT(((_x).established_timings[0]), 2)
193 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_56(_x) \
194 GET_BIT(((_x).established_timings[0]), 1)
195 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_60(_x) \
196 GET_BIT(((_x).established_timings[0]), 0)
197 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_72(_x) \
198 GET_BIT(((_x).established_timings[1]), 7)
199 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_75(_x) \
200 GET_BIT(((_x).established_timings[1]), 6)
201 #define EDID1_INFO_ESTABLISHED_TIMING_832X624_75(_x) \
202 GET_BIT(((_x).established_timings[1]), 5)
203 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(_x) \
204 GET_BIT(((_x).established_timings[1]), 4)
205 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(_x) \
206 GET_BIT(((_x).established_timings[1]), 3)
207 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(_x) \
208 GET_BIT(((_x).established_timings[1]), 2)
209 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(_x) \
210 GET_BIT(((_x).established_timings[1]), 1)
211 #define EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(_x) \
212 GET_BIT(((_x).established_timings[1]), 0)
213 #define EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(_x) \
214 GET_BIT(((_x).established_timings[2]), 7)
216 unsigned char xresolution;
217 unsigned char aspect_vfreq;
218 } __attribute__((__packed__)) standard_timings[8];
219 #define EDID1_INFO_STANDARD_TIMING_XRESOLUTION(_x, _i) \
220 (((_x).standard_timings[_i]).xresolution)
221 #define EDID1_INFO_STANDARD_TIMING_ASPECT(_x, _i) \
222 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 7, 6)
223 #define EDID1_INFO_STANDARD_TIMING_VFREQ(_x, _i) \
224 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 5, 0)
226 unsigned char timing[72];
227 struct edid_monitor_descriptor descriptor[4];
229 unsigned char extension_flag;
230 unsigned char checksum;
231 } __attribute__ ((__packed__));
233 struct edid_cea861_info {
234 unsigned char extension_tag;
235 #define EDID_CEA861_EXTENSION_TAG 0x02
236 unsigned char revision;
237 unsigned char dtd_offset;
238 unsigned char dtd_count;
239 #define EDID_CEA861_SUPPORTS_UNDERSCAN(_x) \
240 GET_BIT(((_x).dtd_count), 7)
241 #define EDID_CEA861_SUPPORTS_BASIC_AUDIO(_x) \
242 GET_BIT(((_x).dtd_count), 6)
243 #define EDID_CEA861_SUPPORTS_YUV444(_x) \
244 GET_BIT(((_x).dtd_count), 5)
245 #define EDID_CEA861_SUPPORTS_YUV422(_x) \
246 GET_BIT(((_x).dtd_count), 4)
247 #define EDID_CEA861_DTD_COUNT(_x) \
248 GET_BITS(((_x).dtd_count), 3, 0)
249 unsigned char data[124];
250 } __attribute__ ((__packed__));
253 * Print the EDID info.
255 * @param edid_info The EDID info to be printed
257 void edid_print_info(struct edid1_info *edid_info);
260 * Check the EDID info.
262 * @param info The EDID info to be checked
263 * @return 0 on valid, or -1 on invalid
265 int edid_check_info(struct edid1_info *info);
268 * Check checksum of a 128 bytes EDID data block
270 * @param edid_block EDID block data
272 * @return 0 on success, or a negative errno on error
274 int edid_check_checksum(u8 *edid_block);
277 * Get the horizontal and vertical rate ranges of the monitor.
279 * @param edid The EDID info
280 * @param hmin Returns the minimum horizontal rate
281 * @param hmax Returns the maxium horizontal rate
282 * @param vmin Returns the minimum vertical rate
283 * @param vmax Returns the maxium vertical rate
284 * @return 0 on success, or -1 on error
286 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
287 unsigned int *hmax, unsigned int *vmin,
290 #endif /* __EDID_H_ */