Display Controller
------------------
(there isn't yet a generic binding in Linux, so this describes what is in
U-Boot, and may change based on Linux activity)
The device node for a display device is as described in the document
"Open Firmware Recommended Practice : Universal Serial Bus" with the
following modifications and additions :
Required properties :
- compatible : Should be "nvidia,tegra20-dc"
Required subnode 'rgb' is as follows:
Required properties (rgb) :
- nvidia,panel : phandle of LCD panel information
The panel node describes the panel itself. This has the properties listed in
displaymode.txt as well as:
Required properties (panel) :
- nvidia,bits-per-pixel: number of bits per pixel (depth)
- nvidia,pwm : pwm to use to set display contrast (see tegra20-pwm.txt)
- nvidia,panel-timings: 4 cells containing required timings in ms:
* delay before asserting panel_vdd
* delay between panel_vdd-rise and data-rise
* delay between data-rise and backlight_vdd-rise
* delay between backlight_vdd and pwm-rise
* delay between pwm-rise and backlight_en-rise
Optional GPIO properies all have (phandle, GPIO number, flags):
- nvidia,backlight-enable-gpios: backlight enable GPIO
- nvidia,lvds-shutdown-gpios: LVDS power shutdown GPIO
- nvidia,backlight-vdd-gpios: backlight power GPIO
- nvidia,panel-vdd-gpios: panel power GPIO
Example:
host1x {
compatible = "nvidia,tegra20-host1x", "simple-bus";
reg = <0x50000000 0x00024000>;
interrupts = <0 65 0x04 /* mpcore syncpt */
0 67 0x04>; /* mpcore general */
#address-cells = <1>;
#size-cells = <1>;
status = "okay";
ranges = <0x54000000 0x54000000 0x04000000>;
dc@54200000 {
compatible = "nvidia,tegra20-dc";
reg = <0x54200000 0x00040000>;
interrupts = <0 73 0x04>;
status = "okay";
rgb {
status = "okay";
nvidia,panel = <&lcd_panel>;
};
};
};
lcd_panel: panel {
/* Seaboard has 1366x768 */
clock = <70600000>;
xres = <1366>;
yres = <768>;
left-margin = <58>;
right-margin = <58>;
hsync-len = <58>;
lower-margin = <4>;
upper-margin = <4>;
vsync-len = <4>;
hsync-active-high;
nvidia,bits-per-pixel = <16>;
nvidia,pwm = <&pwm 2 0>;
nvidia,backlight-enable-gpios = <&gpio 28 0>; /* PD4 */
nvidia,lvds-shutdown-gpios = <&gpio 10 0>; /* PB2 */
nvidia,backlight-vdd-gpios = <&gpio 176 0>; /* PW0 */
nvidia,panel-vdd-gpios = <&gpio 22 0>; /* PC6 */
nvidia,panel-timings = <400 4 203 17 15>;
};