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>

1 files changed, 261 insertions, 0 deletions

diff --git a/Documentation/EDID/edid.S b/Documentation/EDID/edid.S
new file mode 100644
index 000000000000..ea97ae275fca
--- /dev/null
+++ b/Documentation/EDID/edid.S
@@ -0,0 +1,261 @@
+/*
+   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 */