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linux-next/Documentation/EDID/edid.S
Carsten Emde da0df92b57 drm: allow loading an EDID as firmware to override broken monitor
Broken monitors and/or broken graphic boards may send erroneous or no
EDID data. This also applies to broken KVM devices that are unable to
correctly forward the EDID data of the connected monitor but invent
their own fantasy data.

This patch allows to specify an EDID data set to be used instead of
probing the monitor for it. It contains built-in data sets of frequently
used screen resolutions. In addition, a particular EDID data set may be
provided in the /lib/firmware directory and loaded via the firmware
interface. The name is passed to the kernel as module parameter of the
drm_kms_helper module either when loaded
  options drm_kms_helper edid_firmware=edid/1280x1024.bin
or as kernel commandline parameter
  drm_kms_helper.edid_firmware=edid/1280x1024.bin

It is also possible to restrict the usage of a specified EDID data set
to a particular connector. This is done by prepending the name of the
connector to the name of the EDID data set using the syntax
  edid_firmware=[<connector>:]<edid>
such as, for example,
  edid_firmware=DVI-I-1:edid/1920x1080.bin
in which case no other connector will be affected.

The built-in data sets are
Resolution    Name
--------------------------------
1024x768      edid/1024x768.bin
1280x1024     edid/1280x1024.bin
1680x1050     edid/1680x1050.bin
1920x1080     edid/1920x1080.bin

They are ignored, if a file with the same name is available in the
/lib/firmware directory.

The built-in EDID data sets are based on standard timings that may not
apply to a particular monitor and even crash it. Ideally, EDID data of
the connected monitor should be used. They may be obtained through the
drm/cardX/cardX-<connector>/edid entry in the /sys/devices PCI directory
of a correctly working graphics adapter.

It is even possible to specify the name of an EDID data set on-the-fly
via the /sys/module interface, e.g.
echo edid/myedid.bin >/sys/module/drm_kms_helper/parameters/edid_firmware
The new screen mode is considered when the related kernel function is
called for the first time after the change. Such calls are made when the
X server is started or when the display settings dialog is opened in an
already running X server.

Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 10:09:28 +00:00

262 lines
9.2 KiB
ArmAsm

/*
edid.S: EDID data template
Copyright (C) 2012 Carsten Emde <C.Emde@osadl.org>
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.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* Manufacturer */
#define MFG_LNX1 'L'
#define MFG_LNX2 'N'
#define MFG_LNX3 'X'
#define SERIAL 0
#define YEAR 2012
#define WEEK 5
/* EDID 1.3 standard definitions */
#define XY_RATIO_16_10 0b00
#define XY_RATIO_4_3 0b01
#define XY_RATIO_5_4 0b10
#define XY_RATIO_16_9 0b11
#define mfgname2id(v1,v2,v3) \
((((v1-'@')&0x1f)<<10)+(((v2-'@')&0x1f)<<5)+((v3-'@')&0x1f))
#define swap16(v1) ((v1>>8)+((v1&0xff)<<8))
#define msbs2(v1,v2) ((((v1>>8)&0x0f)<<4)+((v2>>8)&0x0f))
#define msbs4(v1,v2,v3,v4) \
(((v1&0x03)>>2)+((v2&0x03)>>4)+((v3&0x03)>>6)+((v4&0x03)>>8))
#define pixdpi2mm(pix,dpi) ((pix*25)/dpi)
#define xsize pixdpi2mm(XPIX,DPI)
#define ysize pixdpi2mm(YPIX,DPI)
.data
/* Fixed header pattern */
header: .byte 0x00,0xff,0xff,0xff,0xff,0xff,0xff,0x00
mfg_id: .word swap16(mfgname2id(MFG_LNX1, MFG_LNX2, MFG_LNX3))
prod_code: .word 0
/* Serial number. 32 bits, little endian. */
serial_number: .long SERIAL
/* Week of manufacture */
week: .byte WEEK
/* Year of manufacture, less 1990. (1990-2245)
If week=255, it is the model year instead */
year: .byte YEAR-1990
version: .byte VERSION /* EDID version, usually 1 (for 1.3) */
revision: .byte REVISION /* EDID revision, usually 3 (for 1.3) */
/* If Bit 7=1 Digital input. If set, the following bit definitions apply:
Bits 6-1 Reserved, must be 0
Bit 0 Signal is compatible with VESA DFP 1.x TMDS CRGB,
1 pixel per clock, up to 8 bits per color, MSB aligned,
If Bit 7=0 Analog input. If clear, the following bit definitions apply:
Bits 6-5 Video white and sync levels, relative to blank
00=+0.7/-0.3 V; 01=+0.714/-0.286 V;
10=+1.0/-0.4 V; 11=+0.7/0 V
Bit 4 Blank-to-black setup (pedestal) expected
Bit 3 Separate sync supported
Bit 2 Composite sync (on HSync) supported
Bit 1 Sync on green supported
Bit 0 VSync pulse must be serrated when somposite or
sync-on-green is used. */
video_parms: .byte 0x6d
/* Maximum horizontal image size, in centimetres
(max 292 cm/115 in at 16:9 aspect ratio) */
max_hor_size: .byte xsize/10
/* Maximum vertical image size, in centimetres.
If either byte is 0, undefined (e.g. projector) */
max_vert_size: .byte ysize/10
/* Display gamma, minus 1, times 100 (range 1.00-3.5 */
gamma: .byte 120
/* Bit 7 DPMS standby supported
Bit 6 DPMS suspend supported
Bit 5 DPMS active-off supported
Bits 4-3 Display type: 00=monochrome; 01=RGB colour;
10=non-RGB multicolour; 11=undefined
Bit 2 Standard sRGB colour space. Bytes 25-34 must contain
sRGB standard values.
Bit 1 Preferred timing mode specified in descriptor block 1.
Bit 0 GTF supported with default parameter values. */
dsp_features: .byte 0xea
/* Chromaticity coordinates. */
/* Red and green least-significant bits
Bits 7-6 Red x value least-significant 2 bits
Bits 5-4 Red y value least-significant 2 bits
Bits 3-2 Green x value lst-significant 2 bits
Bits 1-0 Green y value least-significant 2 bits */
red_green_lsb: .byte 0x5e
/* Blue and white least-significant 2 bits */
blue_white_lsb: .byte 0xc0
/* Red x value most significant 8 bits.
0-255 encodes 0-0.996 (255/256); 0-0.999 (1023/1024) with lsbits */
red_x_msb: .byte 0xa4
/* Red y value most significant 8 bits */
red_y_msb: .byte 0x59
/* Green x and y value most significant 8 bits */
green_x_y_msb: .byte 0x4a,0x98
/* Blue x and y value most significant 8 bits */
blue_x_y_msb: .byte 0x25,0x20
/* Default white point x and y value most significant 8 bits */
white_x_y_msb: .byte 0x50,0x54
/* Established timings */
/* Bit 7 720x400 @ 70 Hz
Bit 6 720x400 @ 88 Hz
Bit 5 640x480 @ 60 Hz
Bit 4 640x480 @ 67 Hz
Bit 3 640x480 @ 72 Hz
Bit 2 640x480 @ 75 Hz
Bit 1 800x600 @ 56 Hz
Bit 0 800x600 @ 60 Hz */
estbl_timing1: .byte 0x00
/* Bit 7 800x600 @ 72 Hz
Bit 6 800x600 @ 75 Hz
Bit 5 832x624 @ 75 Hz
Bit 4 1024x768 @ 87 Hz, interlaced (1024x768)
Bit 3 1024x768 @ 60 Hz
Bit 2 1024x768 @ 72 Hz
Bit 1 1024x768 @ 75 Hz
Bit 0 1280x1024 @ 75 Hz */
estbl_timing2: .byte ESTABLISHED_TIMINGS_BITS
/* Bit 7 1152x870 @ 75 Hz (Apple Macintosh II)
Bits 6-0 Other manufacturer-specific display mod */
estbl_timing3: .byte 0x00
/* Standard timing */
/* X resolution, less 31, divided by 8 (256-2288 pixels) */
std_xres: .byte (XPIX/8)-31
/* Y resolution, X:Y pixel ratio
Bits 7-6 X:Y pixel ratio: 00=16:10; 01=4:3; 10=5:4; 11=16:9.
Bits 5-0 Vertical frequency, less 60 (60-123 Hz) */
std_vres: .byte (XY_RATIO<<6)+VFREQ-60
.fill 7,2,0x0101 /* Unused */
descriptor1:
/* Pixel clock in 10 kHz units. (0.-655.35 MHz, little-endian) */
clock: .word CLOCK/10
/* Horizontal active pixels 8 lsbits (0-4095) */
x_act_lsb: .byte XPIX&0xff
/* Horizontal blanking pixels 8 lsbits (0-4095)
End of active to start of next active. */
x_blk_lsb: .byte XBLANK&0xff
/* Bits 7-4 Horizontal active pixels 4 msbits
Bits 3-0 Horizontal blanking pixels 4 msbits */
x_msbs: .byte msbs2(XPIX,XBLANK)
/* Vertical active lines 8 lsbits (0-4095) */
y_act_lsb: .byte YPIX&0xff
/* Vertical blanking lines 8 lsbits (0-4095) */
y_blk_lsb: .byte YBLANK&0xff
/* Bits 7-4 Vertical active lines 4 msbits
Bits 3-0 Vertical blanking lines 4 msbits */
y_msbs: .byte msbs2(YPIX,YBLANK)
/* Horizontal sync offset pixels 8 lsbits (0-1023) From blanking start */
x_snc_off_lsb: .byte XOFFSET&0xff
/* Horizontal sync pulse width pixels 8 lsbits (0-1023) */
x_snc_pls_lsb: .byte XPULSE&0xff
/* Bits 7-4 Vertical sync offset lines 4 lsbits -63)
Bits 3-0 Vertical sync pulse width lines 4 lsbits -63) */
y_snc_lsb: .byte ((YOFFSET-63)<<4)+(YPULSE-63)
/* Bits 7-6 Horizontal sync offset pixels 2 msbits
Bits 5-4 Horizontal sync pulse width pixels 2 msbits
Bits 3-2 Vertical sync offset lines 2 msbits
Bits 1-0 Vertical sync pulse width lines 2 msbits */
xy_snc_msbs: .byte msbs4(XOFFSET,XPULSE,YOFFSET,YPULSE)
/* Horizontal display size, mm, 8 lsbits (0-4095 mm, 161 in) */
x_dsp_size: .byte xsize&0xff
/* Vertical display size, mm, 8 lsbits (0-4095 mm, 161 in) */
y_dsp_size: .byte ysize&0xff
/* Bits 7-4 Horizontal display size, mm, 4 msbits
Bits 3-0 Vertical display size, mm, 4 msbits */
dsp_size_mbsb: .byte msbs2(xsize,ysize)
/* Horizontal border pixels (each side; total is twice this) */
x_border: .byte 0
/* Vertical border lines (each side; total is twice this) */
y_border: .byte 0
/* Bit 7 Interlaced
Bits 6-5 Stereo mode: 00=No stereo; other values depend on bit 0:
Bit 0=0: 01=Field sequential, sync=1 during right; 10=similar,
sync=1 during left; 11=4-way interleaved stereo
Bit 0=1 2-way interleaved stereo: 01=Right image on even lines;
10=Left image on even lines; 11=side-by-side
Bits 4-3 Sync type: 00=Analog composite; 01=Bipolar analog composite;
10=Digital composite (on HSync); 11=Digital separate
Bit 2 If digital separate: Vertical sync polarity (1=positive)
Other types: VSync serrated (HSync during VSync)
Bit 1 If analog sync: Sync on all 3 RGB lines (else green only)
Digital: HSync polarity (1=positive)
Bit 0 2-way line-interleaved stereo, if bits 4-3 are not 00. */
features: .byte 0x18+(VSYNC_POL<<2)+(HSYNC_POL<<1)
descriptor2: .byte 0,0 /* Not a detailed timing descriptor */
.byte 0 /* Must be zero */
.byte 0xff /* Descriptor is monitor serial number (text) */
.byte 0 /* Must be zero */
start1: .ascii "Linux #0"
end1: .byte 0x0a /* End marker */
.fill 12-(end1-start1), 1, 0x20 /* Padded spaces */
descriptor3: .byte 0,0 /* Not a detailed timing descriptor */
.byte 0 /* Must be zero */
.byte 0xfd /* Descriptor is monitor range limits */
.byte 0 /* Must be zero */
start2: .byte VFREQ-1 /* Minimum vertical field rate (1-255 Hz) */
.byte VFREQ+1 /* Maximum vertical field rate (1-255 Hz) */
.byte (CLOCK/(XPIX+XBLANK))-1 /* Minimum horizontal line rate
(1-255 kHz) */
.byte (CLOCK/(XPIX+XBLANK))+1 /* Maximum horizontal line rate
(1-255 kHz) */
.byte (CLOCK/10000)+1 /* Maximum pixel clock rate, rounded up
to 10 MHz multiple (10-2550 MHz) */
.byte 0 /* No extended timing information type */
end2: .byte 0x0a /* End marker */
.fill 12-(end2-start2), 1, 0x20 /* Padded spaces */
descriptor4: .byte 0,0 /* Not a detailed timing descriptor */
.byte 0 /* Must be zero */
.byte 0xfc /* Descriptor is text */
.byte 0 /* Must be zero */
start3: .ascii TIMING_NAME
end3: .byte 0x0a /* End marker */
.fill 12-(end3-start3), 1, 0x20 /* Padded spaces */
extensions: .byte 0 /* Number of extensions to follow */
checksum: .byte CRC /* Sum of all bytes must be 0 */