* (C) Copyright 2000
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
*
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * 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
-- GENIETV with AD7177 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|vga|composite-*] - 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 video output over the VGA connector.
+ composite-pal/composite-ntsc/composite-pal-m/composite-pal-nc:
+ Selects composite video output, note the specified resolution is
+ ignored with composite video output.
+ 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. Fallback to the lcd / vga / none in that order (if available)
+ Defaults to hpd=1.
+
+- hpd_delay=<int> - How long to wait for the hdmi HPD signal in milliseconds
+ When the monitor and the board power up at the same time, it may take some
+ time for the monitor to assert the HPD signal. This configures how long to
+ wait for the HPD signal before assuming no cable is connected.
+ Defaults to hpd_delay=500.
+
+- 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: "setenv video-mode sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=1".
projects / karo-tx-uboot.git / blobdiff