include/edid.h

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