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
  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_ */