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authorSimon Glass <sjg@chromium.org>2012-10-17 13:24:48 +0000
committerTom Warren <twarren@nvidia.com>2012-11-19 08:15:36 -0700
commiteefe3e598e38dc4e433d5b39c2f5528ffea461e3 (patch)
tree31dc770b3c14414f84b25ace290ae76fdc5a3fc3 /doc
parentbeca1fdeff1a3826148330e2a40297594a710a40 (diff)
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tegra: fdt: Add LCD definitions for Tegra
Add LCD definitions and also a proposed binding for LCD displays. The PWM is as per what will likely be committed to linux-next soon. The displaymode binding comes from a proposal here: http://lists.freedesktop.org/archives/dri-devel/2012-July/024875.html The panel binding is new, and fills a need to specify the panel timings and other tegra-specific information. Should a binding appear that allows the pwm to handle this automatically, we can revisit this. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Tom Warren <twarren@nvidia.com>
Diffstat (limited to 'doc')
-rw-r--r--doc/device-tree-bindings/video/displaymode.txt42
-rw-r--r--doc/device-tree-bindings/video/tegra20-dc.txt85
2 files changed, 127 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/video/displaymode.txt b/doc/device-tree-bindings/video/displaymode.txt
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+++ b/doc/device-tree-bindings/video/displaymode.txt
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+videomode bindings
+==================
+
+(from http://lists.freedesktop.org/archives/dri-devel/2012-July/024875.html)
+
+Required properties:
+ - xres, yres: Display resolution
+ - left-margin, right-margin, hsync-len: Horizontal Display timing
+ parameters in pixels
+ - upper-margin, lower-margin, vsync-len: Vertical display timing
+ parameters in lines
+ - clock: display clock in Hz
+
+Optional properties:
+ - width-mm, height-mm: Display dimensions in mm
+ - hsync-active-high (bool): Hsync pulse is active high
+ - vsync-active-high (bool): Vsync pulse is active high
+ - interlaced (bool): This is an interlaced mode
+ - doublescan (bool): This is a doublescan mode
+
+There are different ways of describing a display mode. The devicetree
+representation corresponds to the one used by the Linux Framebuffer
+framework described here in Documentation/fb/framebuffer.txt. This
+representation has been chosen because it's the only format which does
+not allow for inconsistent parameters. Unlike the Framebuffer framework
+the devicetree has the clock in Hz instead of ps.
+
+Example:
+
+ display@0 {
+ /* 1920x1080p24 */
+ clock = <52000000>;
+ xres = <1920>;
+ yres = <1080>;
+ left-margin = <25>;
+ right-margin = <25>;
+ hsync-len = <25>;
+ lower-margin = <2>;
+ upper-margin = <2>;
+ vsync-len = <2>;
+ hsync-active-high;
+ };
diff --git a/doc/device-tree-bindings/video/tegra20-dc.txt b/doc/device-tree-bindings/video/tegra20-dc.txt
new file mode 100644
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+++ b/doc/device-tree-bindings/video/tegra20-dc.txt
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+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>;
+};