1 /* 2 * Copyright (c) 2012 The Chromium OS Authors. 3 * 4 * (C) Copyright 2010 5 * Petr Stetiar <ynezz@true.cz> 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 * 9 * Contains stolen code from ddcprobe project which is: 10 * Copyright (C) Nalin Dahyabhai <bigfun@pobox.com> 11 */ 12 13 #ifndef __EDID_H_ 14 #define __EDID_H_ 15 16 #include <linux/types.h> 17 18 /* Size of the EDID data */ 19 #define EDID_SIZE 128 20 21 #define GET_BIT(_x, _pos) \ 22 (((_x) >> (_pos)) & 1) 23 #define GET_BITS(_x, _pos_msb, _pos_lsb) \ 24 (((_x) >> (_pos_lsb)) & ((1 << ((_pos_msb) - (_pos_lsb) + 1)) - 1)) 25 26 /* Aspect ratios used in EDID info. */ 27 enum edid_aspect { 28 ASPECT_625 = 0, 29 ASPECT_75, 30 ASPECT_8, 31 ASPECT_5625, 32 }; 33 34 /* Detailed timing information used in EDID v1.x */ 35 struct edid_detailed_timing { 36 unsigned char pixel_clock[2]; 37 #define EDID_DETAILED_TIMING_PIXEL_CLOCK(_x) \ 38 (((((uint32_t)(_x).pixel_clock[1]) << 8) + \ 39 (_x).pixel_clock[0]) * 10000) 40 unsigned char horizontal_active; 41 unsigned char horizontal_blanking; 42 unsigned char horizontal_active_blanking_hi; 43 #define EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(_x) \ 44 ((GET_BITS((_x).horizontal_active_blanking_hi, 7, 4) << 8) + \ 45 (_x).horizontal_active) 46 #define EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(_x) \ 47 ((GET_BITS((_x).horizontal_active_blanking_hi, 3, 0) << 8) + \ 48 (_x).horizontal_blanking) 49 unsigned char vertical_active; 50 unsigned char vertical_blanking; 51 unsigned char vertical_active_blanking_hi; 52 #define EDID_DETAILED_TIMING_VERTICAL_ACTIVE(_x) \ 53 ((GET_BITS((_x).vertical_active_blanking_hi, 7, 4) << 8) + \ 54 (_x).vertical_active) 55 #define EDID_DETAILED_TIMING_VERTICAL_BLANKING(_x) \ 56 ((GET_BITS((_x).vertical_active_blanking_hi, 3, 0) << 8) + \ 57 (_x).vertical_blanking) 58 unsigned char hsync_offset; 59 unsigned char hsync_pulse_width; 60 unsigned char vsync_offset_pulse_width; 61 unsigned char hsync_vsync_offset_pulse_width_hi; 62 #define EDID_DETAILED_TIMING_HSYNC_OFFSET(_x) \ 63 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 7, 6) << 8) + \ 64 (_x).hsync_offset) 65 #define EDID_DETAILED_TIMING_HSYNC_PULSE_WIDTH(_x) \ 66 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 5, 4) << 8) + \ 67 (_x).hsync_pulse_width) 68 #define EDID_DETAILED_TIMING_VSYNC_OFFSET(_x) \ 69 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 3, 2) << 4) + \ 70 GET_BITS((_x).vsync_offset_pulse_width, 7, 4)) 71 #define EDID_DETAILED_TIMING_VSYNC_PULSE_WIDTH(_x) \ 72 ((GET_BITS((_x).hsync_vsync_offset_pulse_width_hi, 1, 0) << 4) + \ 73 GET_BITS((_x).vsync_offset_pulse_width, 3, 0)) 74 unsigned char himage_size; 75 unsigned char vimage_size; 76 unsigned char himage_vimage_size_hi; 77 #define EDID_DETAILED_TIMING_HIMAGE_SIZE(_x) \ 78 ((GET_BITS((_x).himage_vimage_size_hi, 7, 4) << 8) + (_x).himage_size) 79 #define EDID_DETAILED_TIMING_VIMAGE_SIZE(_x) \ 80 ((GET_BITS((_x).himage_vimage_size_hi, 3, 0) << 8) + (_x).vimage_size) 81 unsigned char hborder; 82 unsigned char vborder; 83 unsigned char flags; 84 #define EDID_DETAILED_TIMING_FLAG_INTERLACED(_x) \ 85 GET_BIT((_x).flags, 7) 86 #define EDID_DETAILED_TIMING_FLAG_STEREO(_x) \ 87 GET_BITS((_x).flags, 6, 5) 88 #define EDID_DETAILED_TIMING_FLAG_DIGITAL_COMPOSITE(_x) \ 89 GET_BITS((_x).flags, 4, 3) 90 #define EDID_DETAILED_TIMING_FLAG_POLARITY(_x) \ 91 GET_BITS((_x).flags, 2, 1) 92 #define EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(_x) \ 93 GET_BIT((_x).flags, 2) 94 #define EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(_x) \ 95 GET_BIT((_x).flags, 1) 96 #define EDID_DETAILED_TIMING_FLAG_INTERLEAVED(_x) \ 97 GET_BIT((_x).flags, 0) 98 } __attribute__ ((__packed__)); 99 100 enum edid_monitor_descriptor_types { 101 EDID_MONITOR_DESCRIPTOR_SERIAL = 0xff, 102 EDID_MONITOR_DESCRIPTOR_ASCII = 0xfe, 103 EDID_MONITOR_DESCRIPTOR_RANGE = 0xfd, 104 EDID_MONITOR_DESCRIPTOR_NAME = 0xfc, 105 }; 106 107 struct edid_monitor_descriptor { 108 uint16_t zero_flag_1; 109 unsigned char zero_flag_2; 110 unsigned char type; 111 unsigned char zero_flag_3; 112 union { 113 char string[13]; 114 struct { 115 unsigned char vertical_min; 116 unsigned char vertical_max; 117 unsigned char horizontal_min; 118 unsigned char horizontal_max; 119 unsigned char pixel_clock_max; 120 unsigned char gtf_data[8]; 121 } range_data; 122 } data; 123 } __attribute__ ((__packed__)); 124 125 struct edid1_info { 126 unsigned char header[8]; 127 unsigned char manufacturer_name[2]; 128 #define EDID1_INFO_MANUFACTURER_NAME_ZERO(_x) \ 129 GET_BIT(((_x).manufacturer_name[0]), 7) 130 #define EDID1_INFO_MANUFACTURER_NAME_CHAR1(_x) \ 131 GET_BITS(((_x).manufacturer_name[0]), 6, 2) 132 #define EDID1_INFO_MANUFACTURER_NAME_CHAR2(_x) \ 133 ((GET_BITS(((_x).manufacturer_name[0]), 1, 0) << 3) + \ 134 GET_BITS(((_x).manufacturer_name[1]), 7, 5)) 135 #define EDID1_INFO_MANUFACTURER_NAME_CHAR3(_x) \ 136 GET_BITS(((_x).manufacturer_name[1]), 4, 0) 137 unsigned char product_code[2]; 138 #define EDID1_INFO_PRODUCT_CODE(_x) \ 139 (((uint16_t)(_x).product_code[1] << 8) + (_x).product_code[0]) 140 unsigned char serial_number[4]; 141 #define EDID1_INFO_SERIAL_NUMBER(_x) \ 142 (((uint32_t)(_x).serial_number[3] << 24) + \ 143 ((_x).serial_number[2] << 16) + ((_x).serial_number[1] << 8) + \ 144 (_x).serial_number[0]) 145 unsigned char week; 146 unsigned char year; 147 unsigned char version; 148 unsigned char revision; 149 unsigned char video_input_definition; 150 #define EDID1_INFO_VIDEO_INPUT_DIGITAL(_x) \ 151 GET_BIT(((_x).video_input_definition), 7) 152 #define EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(_x) \ 153 GET_BITS(((_x).video_input_definition), 6, 5) 154 #define EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(_x) \ 155 GET_BIT(((_x).video_input_definition), 4) 156 #define EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(_x) \ 157 GET_BIT(((_x).video_input_definition), 3) 158 #define EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(_x) \ 159 GET_BIT(((_x).video_input_definition), 2) 160 #define EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(_x) \ 161 GET_BIT(((_x).video_input_definition), 1) 162 #define EDID1_INFO_VIDEO_INPUT_SERRATION_V(_x) \ 163 GET_BIT(((_x).video_input_definition), 0) 164 unsigned char max_size_horizontal; 165 unsigned char max_size_vertical; 166 unsigned char gamma; 167 unsigned char feature_support; 168 #define EDID1_INFO_FEATURE_STANDBY(_x) \ 169 GET_BIT(((_x).feature_support), 7) 170 #define EDID1_INFO_FEATURE_SUSPEND(_x) \ 171 GET_BIT(((_x).feature_support), 6) 172 #define EDID1_INFO_FEATURE_ACTIVE_OFF(_x) \ 173 GET_BIT(((_x).feature_support), 5) 174 #define EDID1_INFO_FEATURE_DISPLAY_TYPE(_x) \ 175 GET_BITS(((_x).feature_support), 4, 3) 176 #define EDID1_INFO_FEATURE_RGB(_x) \ 177 GET_BIT(((_x).feature_support), 2) 178 #define EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(_x) \ 179 GET_BIT(((_x).feature_support), 1) 180 #define EDID1_INFO_FEATURE_DEFAULT_GTF_SUPPORT(_x) \ 181 GET_BIT(((_x).feature_support), 0) 182 unsigned char color_characteristics[10]; 183 unsigned char established_timings[3]; 184 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_70(_x) \ 185 GET_BIT(((_x).established_timings[0]), 7) 186 #define EDID1_INFO_ESTABLISHED_TIMING_720X400_88(_x) \ 187 GET_BIT(((_x).established_timings[0]), 6) 188 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_60(_x) \ 189 GET_BIT(((_x).established_timings[0]), 5) 190 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_67(_x) \ 191 GET_BIT(((_x).established_timings[0]), 4) 192 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_72(_x) \ 193 GET_BIT(((_x).established_timings[0]), 3) 194 #define EDID1_INFO_ESTABLISHED_TIMING_640X480_75(_x) \ 195 GET_BIT(((_x).established_timings[0]), 2) 196 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_56(_x) \ 197 GET_BIT(((_x).established_timings[0]), 1) 198 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_60(_x) \ 199 GET_BIT(((_x).established_timings[0]), 0) 200 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_72(_x) \ 201 GET_BIT(((_x).established_timings[1]), 7) 202 #define EDID1_INFO_ESTABLISHED_TIMING_800X600_75(_x) \ 203 GET_BIT(((_x).established_timings[1]), 6) 204 #define EDID1_INFO_ESTABLISHED_TIMING_832X624_75(_x) \ 205 GET_BIT(((_x).established_timings[1]), 5) 206 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(_x) \ 207 GET_BIT(((_x).established_timings[1]), 4) 208 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(_x) \ 209 GET_BIT(((_x).established_timings[1]), 3) 210 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(_x) \ 211 GET_BIT(((_x).established_timings[1]), 2) 212 #define EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(_x) \ 213 GET_BIT(((_x).established_timings[1]), 1) 214 #define EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(_x) \ 215 GET_BIT(((_x).established_timings[1]), 0) 216 #define EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(_x) \ 217 GET_BIT(((_x).established_timings[2]), 7) 218 struct { 219 unsigned char xresolution; 220 unsigned char aspect_vfreq; 221 } __attribute__((__packed__)) standard_timings[8]; 222 #define EDID1_INFO_STANDARD_TIMING_XRESOLUTION(_x, _i) \ 223 (((_x).standard_timings[_i]).xresolution) 224 #define EDID1_INFO_STANDARD_TIMING_ASPECT(_x, _i) \ 225 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 7, 6) 226 #define EDID1_INFO_STANDARD_TIMING_VFREQ(_x, _i) \ 227 GET_BITS(((_x).standard_timings[_i].aspect_vfreq), 5, 0) 228 union { 229 unsigned char timing[72]; 230 struct edid_monitor_descriptor descriptor[4]; 231 } monitor_details; 232 unsigned char extension_flag; 233 unsigned char checksum; 234 } __attribute__ ((__packed__)); 235 236 struct edid_cea861_info { 237 unsigned char extension_tag; 238 #define EDID_CEA861_EXTENSION_TAG 0x02 239 unsigned char revision; 240 unsigned char dtd_offset; 241 unsigned char dtd_count; 242 #define EDID_CEA861_SUPPORTS_UNDERSCAN(_x) \ 243 GET_BIT(((_x).dtd_count), 7) 244 #define EDID_CEA861_SUPPORTS_BASIC_AUDIO(_x) \ 245 GET_BIT(((_x).dtd_count), 6) 246 #define EDID_CEA861_SUPPORTS_YUV444(_x) \ 247 GET_BIT(((_x).dtd_count), 5) 248 #define EDID_CEA861_SUPPORTS_YUV422(_x) \ 249 GET_BIT(((_x).dtd_count), 4) 250 #define EDID_CEA861_DTD_COUNT(_x) \ 251 GET_BITS(((_x).dtd_count), 3, 0) 252 unsigned char data[124]; 253 } __attribute__ ((__packed__)); 254 255 /** 256 * Print the EDID info. 257 * 258 * @param edid_info The EDID info to be printed 259 */ 260 void edid_print_info(struct edid1_info *edid_info); 261 262 /** 263 * Check the EDID info. 264 * 265 * @param info The EDID info to be checked 266 * @return 0 on valid, or -1 on invalid 267 */ 268 int edid_check_info(struct edid1_info *info); 269 270 /** 271 * Check checksum of a 128 bytes EDID data block 272 * 273 * @param edid_block EDID block data 274 * 275 * @return 0 on success, or a negative errno on error 276 */ 277 int edid_check_checksum(u8 *edid_block); 278 279 /** 280 * Get the horizontal and vertical rate ranges of the monitor. 281 * 282 * @param edid The EDID info 283 * @param hmin Returns the minimum horizontal rate 284 * @param hmax Returns the maxium horizontal rate 285 * @param vmin Returns the minimum vertical rate 286 * @param vmax Returns the maxium vertical rate 287 * @return 0 on success, or -1 on error 288 */ 289 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin, 290 unsigned int *hmax, unsigned int *vmin, 291 unsigned int *vmax); 292 293 struct display_timing; 294 295 /** 296 * edid_get_timing() - Get basic digital display parameters 297 * 298 * @param buf Buffer containing EDID data 299 * @param buf_size Size of buffer in bytes 300 * @param timing Place to put preferring timing information 301 * @param panel_bits_per_colourp Place to put the number of bits per 302 * colour supported by the panel. This will be set to 303 * -1 if not available 304 * @return 0 if timings are OK, -ve on error 305 */ 306 int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing, 307 int *panel_bits_per_colourp); 308 309 #endif /* __EDID_H_ */ 310