src/include/edid.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #ifndef EDID_H
   4 #define EDID_H
   5
   6 #include <stdint.h>
   7 #include "commonlib/coreboot_tables.h"
   8
   9 enum edid_modes {
  10         EDID_MODE_640x480_60Hz,
  11         EDID_MODE_720x480_60Hz,
  12         EDID_MODE_1280x720_60Hz,
  13         EDID_MODE_1920x1080_60Hz,
  14         NUM_KNOWN_MODES,
  15
  16         EDID_MODE_AUTO
  17 };
  18
  19 struct edid_mode {
  20         const char *name;
  21         unsigned int pixel_clock;
  22         int lvds_dual_channel;
  23         unsigned int refresh;
  24         unsigned int ha;
  25         unsigned int hbl;
  26         unsigned int hso;
  27         unsigned int hspw;
  28         unsigned int hborder;
  29         unsigned int va;
  30         unsigned int vbl;
  31         unsigned int vso;
  32         unsigned int vspw;
  33         unsigned int vborder;
  34         unsigned char phsync;
  35         unsigned char pvsync;
  36         unsigned int x_mm;
  37         unsigned int y_mm;
  38 };
  39
  40 /* structure for communicating EDID information from a raw EDID block to
  41  * higher level functions.
  42  * The size of the data types is not critical, so we leave them as
  43  * unsigned int. We can move more into into this struct as needed.
  44  */
  45
  46 #define EDID_ASCII_STRING_LENGTH 13
  47
  48 struct edid {
  49         /* These next three things used to all be called bpp.
  50          * Merriment ensued. The identifier
  51          * 'bpp' is herewith banished from our
  52          * Kingdom.
  53          */
  54         /* How many bits in the framebuffer per pixel.
  55          * Under all reasonable circumstances, it's 32.
  56          */
  57         unsigned int framebuffer_bits_per_pixel;
  58         /* On the panel, how many bits per color?
  59          * In almost all cases, it's 6 or 8.
  60          * The standard allows for much more!
  61          */
  62         unsigned int panel_bits_per_color;
  63         /* On the panel, how many bits per pixel.
  64          * On Planet Earth, there are three colors
  65          * per pixel, but this is convenient to have here
  66          * instead of having 3*panel_bits_per_color
  67          * all over the place.
  68          */
  69         unsigned int panel_bits_per_pixel;
  70         /* used to compute timing for graphics chips. */
  71         struct edid_mode mode;
  72         u8 mode_is_supported[NUM_KNOWN_MODES];
  73         unsigned int link_clock;
  74         /* 3 variables needed for coreboot framebuffer.
  75          * In most cases, they are the same as the ha
  76          * and va variables, but not always, as in the
  77          * case of a 1366 wide display.
  78          */
  79         u32 x_resolution;
  80         u32 y_resolution;
  81         u32 bytes_per_line;
  82
  83         int hdmi_monitor_detected;
  84         char ascii_string[EDID_ASCII_STRING_LENGTH + 1];
  85         char manufacturer_name[3 + 1];
  86 };
  87
  88 enum edid_status {
  89         EDID_CONFORMANT,
  90         EDID_NOT_CONFORMANT,
  91         EDID_ABSENT,
  92 };
  93
  94 /* Defined in src/lib/edid.c */
  95 int decode_edid(unsigned char *edid, int size, struct edid *out);
  96 void edid_set_framebuffer_bits_per_pixel(struct edid *edid, int fb_bpp,
  97                                          int row_byte_alignment);
  98 void set_vbe_mode_info_valid(const struct edid *edid, uintptr_t fb_addr);
  99 void set_vbe_framebuffer_orientation(enum lb_fb_orientation orientation);
 100 int set_display_mode(struct edid *edid, enum edid_modes mode);
 101
 102 #endif /* EDID_H */