u-boot/doc/README.video
Hans de Goede 2dae800f1e sunxi: video: Add lcd output support
Add lcd output support, see the new Kconfig entries and doc/README.video for
how to enable / configure this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
2015-01-14 14:56:39 +01:00

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/*
* (C) Copyright 2000
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
*
* SPDX-License-Identifier: GPL-2.0+
*/
"video-mode" environment variable
=================================
The 'video-mode' environment variable can be used to enable and configure
some video drivers. The format matches the video= command-line option used
for Linux:
video-mode=<driver>:<xres>x<yres>-<depth>@<freq><,option=string>
<driver> The video driver name, ignored by U-Boot
<xres> The X resolution (in pixels) to use.
<yres> The Y resolution (in pixels) to use.
<depth> The color depth (in bits) to use.
<freq> The frequency (in Hz) to use.
<options> A comma-separated list of device-specific options
U-Boot MPC8xx video controller driver
=====================================
The driver has been tested with the following configurations:
- MPC823FADS with AD7176 on a PAL TV (YCbYCr) - arsenio@tin.it
Example: video-mode=fslfb:1280x1024-32@60,monitor=dvi
U-boot sunxi video controller driver
====================================
U-boot supports hdmi and lcd output on Allwinner sunxi SoCs, lcd output
requires the CONFIG_VIDEO_LCD_MODE Kconfig value to be set.
The sunxi u-boot driver supports the following video-mode options:
- monitor=[none|dvi|hdmi|lcd] - Select the video output to use
none: Disable video output.
dvi/hdmi: Selects output over the hdmi connector with dvi resp. hdmi output
format, if edid is used the format is automatically selected.
lcd: Selects video output to a LCD screen.
vga: Selects bideo output over the VGA connector.
Defaults to monitor=dvi.
- hpd=[0|1] - Enable use of the hdmi HotPlug Detect feature
0: Disabled. Configure dvi/hdmi output even if no cable is detected
1: Enabled. If a LCD has been configured fallback to the LCD when no cable is
detected, if no LCD is configured, disable video ouput.
Defaults to hpd=1.
- edid=[0|1] - Enable use of DDC + EDID to get monitor info
0: Disabled.
1: Enabled. If valid EDID info was read from the monitor the EDID info will
overrides the xres, yres and refresh from the video-mode env. variable.
Defaults to edid=1.
For example to always use the hdmi connector, even if no cable is inserted,
using edid info when available and otherwise initalizing it at 1024x768@60Hz,
use: video-mode=sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=1 .