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_INTERLEAVED(_x) \
90 GET_BIT((_x).flags, 0)
91 } __attribute__ ((__packed__));
93 enum edid_monitor_descriptor_types {
94 EDID_MONITOR_DESCRIPTOR_SERIAL = 0xff,
95 EDID_MONITOR_DESCRIPTOR_ASCII = 0xfe,
96 EDID_MONITOR_DESCRIPTOR_RANGE = 0xfd,
97 EDID_MONITOR_DESCRIPTOR_NAME = 0xfc,
100 struct edid_monitor_descriptor {
101 uint16_t zero_flag_1;
102 unsigned char zero_flag_2;
104 unsigned char zero_flag_3;
108 unsigned char vertical_min;
109 unsigned char vertical_max;
110 unsigned char horizontal_min;
111 unsigned char horizontal_max;
112 unsigned char pixel_clock_max;
113 unsigned char gtf_data[8];
116 } __attribute__ ((__packed__));
119 unsigned char header[8];
120 unsigned char manufacturer_name[2];
121 #define EDID1_INFO_MANUFACTURER_NAME_ZERO(_x) \
122 GET_BIT(((_x).manufacturer_name[0]), 7)
123 #define EDID1_INFO_MANUFACTURER_NAME_CHAR1(_x) \
124 GET_BITS(((_x).manufacturer_name[0]), 6, 2)
125 #define EDID1_INFO_MANUFACTURER_NAME_CHAR2(_x) \
126 ((GET_BITS(((_x).manufacturer_name[0]), 1, 0) << 3) + \
127 GET_BITS(((_x).manufacturer_name[1]), 7, 5))
128 #define EDID1_INFO_MANUFACTURER_NAME_CHAR3(_x) \
129 GET_BITS(((_x).manufacturer_name[1]), 4, 0)
130 unsigned char product_code[2];
131 #define EDID1_INFO_PRODUCT_CODE(_x) \
132 (((uint16_t)(_x).product_code[1] << 8) + (_x).product_code[0])
133 unsigned char serial_number[4];
134 #define EDID1_INFO_SERIAL_NUMBER(_x) \
135 (((uint32_t)(_x).serial_number[3] << 24) + \
136 ((_x).serial_number[2] << 16) + ((_x).serial_number[1] << 8) + \
137 (_x).serial_number[0])
140 unsigned char version;
141 unsigned char revision;
142 unsigned char video_input_definition;
143 #define EDID1_INFO_VIDEO_INPUT_DIGITAL(_x) \
144 GET_BIT(((_x).video_input_definition), 7)
145 #define EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(_x) \
146 GET_BITS(((_x).video_input_definition), 6, 5)
147 #define EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(_x) \
148 GET_BIT(((_x).video_input_definition), 4)
149 #define EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(_x) \
150 GET_BIT(((_x).video_input_definition), 3)
151 #define EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(_x) \
152 GET_BIT(((_x).video_input_definition), 2)
153 #define EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(_x) \
154 GET_BIT(((_x).video_input_definition), 1)
155 #define EDID1_INFO_VIDEO_INPUT_SERRATION_V(_x) \
156 GET_BIT(((_x).video_input_definition), 0)
157 unsigned char max_size_horizontal;
158 unsigned char max_size_vertical;
160 unsigned char feature_support;
161 #define EDID1_INFO_FEATURE_STANDBY(_x) \
162 GET_BIT(((_x).feature_support), 7)
163 #define EDID1_INFO_FEATURE_SUSPEND(_x) \
164 GET_BIT(((_x).feature_support), 6)
165 #define EDID1_INFO_FEATURE_ACTIVE_OFF(_x) \
166 GET_BIT(((_x).feature_support), 5)
167 #define EDID1_INFO_FEATURE_DISPLAY_TYPE(_x) \
168 GET_BITS(((_x).feature_support), 4, 3)
169 #define EDID1_INFO_FEATURE_RGB(_x) \
170 GET_BIT(((_x).feature_support), 2)
171 #define EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(_x) \
172 GET_BIT(((_x).feature_support), 1)
173 #define EDID1_INFO_FEATURE_DEFAULT_GTF_SUPPORT(_x) \
174 GET_BIT(((_x).feature_support), 0)
175 unsigned char color_characteristics[10];
176 unsigned char established_timings[3];
177 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_70(_x) \
178 GET_BIT(((_x).established_timings[0]), 7)
179 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_88(_x) \
180 GET_BIT(((_x).established_timings[0]), 6)
181 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_60(_x) \
182 GET_BIT(((_x).established_timings[0]), 5)
183 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_67(_x) \
184 GET_BIT(((_x).established_timings[0]), 4)
185 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_72(_x) \
186 GET_BIT(((_x).established_timings[0]), 3)
187 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_75(_x) \
188 GET_BIT(((_x).established_timings[0]), 2)
189 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_56(_x) \
190 GET_BIT(((_x).established_timings[0]), 1)
191 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_60(_x) \
192 GET_BIT(((_x).established_timings[0]), 0)
193 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_72(_x) \
194 GET_BIT(((_x).established_timings[1]), 7)
195 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_75(_x) \
196 GET_BIT(((_x).established_timings[1]), 6)
197 #define EDID1_INFO_ESTABLISHED_TIMING_832X624_75(_x) \
198 GET_BIT(((_x).established_timings[1]), 5)
199 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(_x) \
200 GET_BIT(((_x).established_timings[1]), 4)
201 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(_x) \
202 GET_BIT(((_x).established_timings[1]), 3)
203 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(_x) \
204 GET_BIT(((_x).established_timings[1]), 2)
205 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(_x) \
206 GET_BIT(((_x).established_timings[1]), 1)
207 #define EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(_x) \
208 GET_BIT(((_x).established_timings[1]), 0)
209 #define EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(_x) \
210 GET_BIT(((_x).established_timings[2]), 7)
212 unsigned char xresolution;
213 unsigned char aspect_vfreq;
214 } __attribute__((__packed__)) standard_timings[8];
215 #define EDID1_INFO_STANDARD_TIMING_XRESOLUTION(_x, _i) \
216 (((_x).standard_timings[_i]).xresolution)
217 #define EDID1_INFO_STANDARD_TIMING_ASPECT(_x, _i) \
218 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 7, 6)
219 #define EDID1_INFO_STANDARD_TIMING_VFREQ(_x, _i) \
220 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 5, 0)
222 unsigned char timing[72];
223 struct edid_monitor_descriptor descriptor[4];
225 unsigned char extension_flag;
226 unsigned char checksum;
227 } __attribute__ ((__packed__));
230 * Print the EDID info.
232 * @param edid_info The EDID info to be printed
234 void edid_print_info(struct edid1_info *edid_info);
237 * Check the EDID info.
239 * @param info The EDID info to be checked
240 * @return 0 on valid, or -1 on invalid
242 int edid_check_info(struct edid1_info *info);
245 * Get the horizontal and vertical rate ranges of the monitor.
247 * @param edid The EDID info
248 * @param hmin Returns the minimum horizontal rate
249 * @param hmax Returns the maxium horizontal rate
250 * @param vmin Returns the minimum vertical rate
251 * @param vmax Returns the maxium vertical rate
252 * @return 0 on success, or -1 on error
254 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
255 unsigned int *hmax, unsigned int *vmin,
258 #endif /* __EDID_H_ */