drm: Add 800x600 (SVGA) screen resolution to the built-in EDIDs

The 800x600 (SVGA) screen resolution was lacking in the set of
built-in selectable EDID screen resolutions that can be used to
repair misbehaving monitor firmware.

This patch adds the related data set and expands the documentation.
Note that the SVGA bit occupies a different byte to all the existing
users of the established timing bits forcing a rework of the
ESTABLISHED_TIMINGS_BITS macro.

Tested new EDID on an aged (and misbehaving) industrial LCD panel;
existing EDIDs still pass edid-decode's checksum checks.

Signed-off-by: Daniel Thompson <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Carsten Emde <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

Documentation/EDID/1024x768.S

···
 #define DPI 72
 #define VFREQ 60 /* Hz */
 #define TIMING_NAME "Linux XGA"
-#define ESTABLISHED_TIMINGS_BITS 0x08 /* Bit 3 -> 1024x768 @60 Hz */
+#define ESTABLISHED_TIMING2_BITS 0x08 /* Bit 3 -> 1024x768 @60 Hz */
 #define HSYNC_POL 0
 #define VSYNC_POL 0
 #define CRC 0x55

Documentation/EDID/1280x1024.S

···
 #define DPI 72
 #define VFREQ 60 /* Hz */
 #define TIMING_NAME "Linux SXGA"
-#define ESTABLISHED_TIMINGS_BITS 0x00 /* none */
+/* No ESTABLISHED_TIMINGx_BITS */
 #define HSYNC_POL 1
 #define VSYNC_POL 1
 #define CRC 0xa0

Documentation/EDID/1600x1200.S

···
 #define DPI 72
 #define VFREQ 60 /* Hz */
 #define TIMING_NAME "Linux UXGA"
-#define ESTABLISHED_TIMINGS_BITS 0x00 /* none */
+/* No ESTABLISHED_TIMINGx_BITS */
 #define HSYNC_POL 1
 #define VSYNC_POL 1
 #define CRC 0x9d

Documentation/EDID/1680x1050.S

···
 #define DPI 96
 #define VFREQ 60 /* Hz */
 #define TIMING_NAME "Linux WSXGA"
-#define ESTABLISHED_TIMINGS_BITS 0x00 /* none */
+/* No ESTABLISHED_TIMINGx_BITS */
 #define HSYNC_POL 1
 #define VSYNC_POL 1
 #define CRC 0x26

Documentation/EDID/1920x1080.S

···
 #define DPI 96
 #define VFREQ 60 /* Hz */
 #define TIMING_NAME "Linux FHD"
-#define ESTABLISHED_TIMINGS_BITS 0x00 /* none */
+/* No ESTABLISHED_TIMINGx_BITS */
 #define HSYNC_POL 1
 #define VSYNC_POL 1
 #define CRC 0x05

Documentation/EDID/800x600.S

···
+/*
+   800x600.S: EDID data set for standard 800x600 60 Hz monitor
+
+   Copyright (C) 2011 Carsten Emde <[e-mail]>
+   Copyright (C) 2014 Linaro Limited
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+*/
+
+/* EDID */
+#define VERSION 1
+#define REVISION 3
+
+/* Display */
+#define CLOCK 40000 /* kHz */
+#define XPIX 800
+#define YPIX 600
+#define XY_RATIO XY_RATIO_4_3
+#define XBLANK 256
+#define YBLANK 28
+#define XOFFSET 40
+#define XPULSE 128
+#define YOFFSET (63+1)
+#define YPULSE (63+4)
+#define DPI 72
+#define VFREQ 60 /* Hz */
+#define TIMING_NAME "Linux SVGA"
+#define ESTABLISHED_TIMING1_BITS 0x01 /* Bit 0: 800x600 @ 60Hz */
+#define HSYNC_POL 1
+#define VSYNC_POL 1
+#define CRC 0xc2
+
+#include "edid.S"

Documentation/EDID/HOWTO.txt

···
 individually prepared or corrected EDID data set in the /lib/firmware
 directory from where it is loaded via the firmware interface. The code
 (see drivers/gpu/drm/drm_edid_load.c) contains built-in data sets for
-commonly used screen resolutions (1024x768, 1280x1024, 1600x1200,
+commonly used screen resolutions (800x600, 1024x768, 1280x1024, 1600x1200,
 1680x1050, 1920x1080) as binary blobs, but the kernel source tree does
 not contain code to create these data. In order to elucidate the origin
 of the built-in binary EDID blobs and to facilitate the creation of

Documentation/EDID/edid.S

···
 #define XY_RATIO_5_4	0b10
 #define XY_RATIO_16_9	0b11
 
+/* Provide defaults for the timing bits */
+#ifndef ESTABLISHED_TIMING1_BITS
+#define ESTABLISHED_TIMING1_BITS 0x00
+#endif
+#ifndef ESTABLISHED_TIMING2_BITS
+#define ESTABLISHED_TIMING2_BITS 0x00
+#endif
+#ifndef ESTABLISHED_TIMING3_BITS
+#define ESTABLISHED_TIMING3_BITS 0x00
+#endif
+
 #define mfgname2id(v1,v2,v3) \
 	((((v1-'@')&0x1f)<<10)+(((v2-'@')&0x1f)<<5)+((v3-'@')&0x1f))
 #define swap16(v1) ((v1>>8)+((v1&0xff)<<8))
···
    Bit 2	640x480 @ 75 Hz
    Bit 1	800x600 @ 56 Hz
    Bit 0	800x600 @ 60 Hz */
-estbl_timing1:	.byte	0x00
+estbl_timing1:	.byte	ESTABLISHED_TIMING1_BITS
 
 /* Bit 7	800x600 @ 72 Hz
    Bit 6	800x600 @ 75 Hz
···
    Bit 2	1024x768 @ 72 Hz
    Bit 1	1024x768 @ 75 Hz
    Bit 0	1280x1024 @ 75 Hz */
-estbl_timing2:	.byte	ESTABLISHED_TIMINGS_BITS
+estbl_timing2:	.byte	ESTABLISHED_TIMING2_BITS
 
 /* Bit 7	1152x870 @ 75 Hz (Apple Macintosh II)
    Bits 6-0 	Other manufacturer-specific display mod */
-estbl_timing3:	.byte	0x00
+estbl_timing3:	.byte	ESTABLISHED_TIMING3_BITS
 
 /* Standard timing */
 /* X resolution, less 31, divided by 8 (256-2288 pixels) */

drivers/gpu/drm/drm_edid_load.c

···
 MODULE_PARM_DESC(edid_firmware, "Do not probe monitor, use specified EDID blob "
 	"from built-in data or /lib/firmware instead. ");
 
-#define GENERIC_EDIDS 5
+#define GENERIC_EDIDS 6
 static const char *generic_edid_name[GENERIC_EDIDS] = {
+	"edid/800x600.bin",
 	"edid/1024x768.bin",
 	"edid/1280x1024.bin",
 	"edid/1600x1200.bin",
···
 };
 
 static const u8 generic_edid[GENERIC_EDIDS][128] = {
+	{
+	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00,
+	0x31, 0xd8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x05, 0x16, 0x01, 0x03, 0x6d, 0x1b, 0x14, 0x78,
+	0xea, 0x5e, 0xc0, 0xa4, 0x59, 0x4a, 0x98, 0x25,
+	0x20, 0x50, 0x54, 0x01, 0x00, 0x00, 0x45, 0x40,
+	0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+	0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0xa0, 0x0f,
+	0x20, 0x00, 0x31, 0x58, 0x1c, 0x20, 0x28, 0x80,
+	0x14, 0x00, 0x15, 0xd0, 0x10, 0x00, 0x00, 0x1e,
+	0x00, 0x00, 0x00, 0xff, 0x00, 0x4c, 0x69, 0x6e,
+	0x75, 0x78, 0x20, 0x23, 0x30, 0x0a, 0x20, 0x20,
+	0x20, 0x20, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x3b,
+	0x3d, 0x24, 0x26, 0x05, 0x00, 0x0a, 0x20, 0x20,
+	0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xfc,
+	0x00, 0x4c, 0x69, 0x6e, 0x75, 0x78, 0x20, 0x53,
+	0x56, 0x47, 0x41, 0x0a, 0x20, 0x20, 0x00, 0xc2,
+	},
 	{
 	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00,
 	0x31, 0xd8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,