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-rw-r--r--Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt81
1 files changed, 52 insertions, 29 deletions
diff --git a/Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt b/Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt
index f5e3c6f2095a..40f3d7c713bb 100644
--- a/Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt
+++ b/Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt
@@ -1,47 +1,70 @@
TPO TPG110 Panel
================
-This binding builds on the DPI bindings, adding a few properties
-as a superset of a DPI. See panel-dpi.txt for the required DPI
-bindings.
+This panel driver is a component that acts as an intermediary
+between an RGB output and a variety of panels. The panel
+driver is strapped up in electronics to the desired resolution
+and other properties, and has a control interface over 3WIRE
+SPI. By talking to the TPG110 over SPI, the strapped properties
+can be discovered and the hardware is therefore mostly
+self-describing.
+
+ +--------+
+SPI -> | TPO | -> physical display
+RGB -> | TPG110 |
+ +--------+
+
+If some electrical strap or alternate resolution is desired,
+this can be set up by taking software control of the display
+over the SPI interface. The interface can also adjust
+for properties of the display such as gamma correction and
+certain electrical driving levels.
+
+The TPG110 does not know the physical dimensions of the panel
+connected, so this needs to be specified in the device tree.
+
+It requires a GPIO line for control of its reset line.
+
+The serial protocol has line names that resemble I2C but the
+protocol is not I2C but 3WIRE SPI.
Required properties:
-- compatible : "tpo,tpg110"
+- compatible : one of:
+ "ste,nomadik-nhk15-display", "tpo,tpg110"
+ "tpo,tpg110"
- grestb-gpios : panel reset GPIO
-- scen-gpios : serial control enable GPIO
-- scl-gpios : serial control clock line GPIO
-- sda-gpios : serial control data line GPIO
+- width-mm : see display/panel/panel-common.txt
+- height-mm : see display/panel/panel-common.txt
+
+The device needs to be a child of an SPI bus, see
+spi/spi-bus.txt. The SPI child must set the following
+properties:
+- spi-3wire
+- spi-max-frequency = <3000000>;
+as these are characteristics of this device.
-Required nodes:
-- Video port for DPI input, see panel-dpi.txt
-- Panel timing for DPI setup, see panel-dpi.txt
+The device node can contain one 'port' child node with one child
+'endpoint' node, according to the bindings defined in
+media/video-interfaces.txt. This node should describe panel's video bus.
Example
-------
-panel {
- compatible = "tpo,tpg110", "panel-dpi";
- grestb-gpios = <&stmpe_gpio44 5 GPIO_ACTIVE_LOW>;
- scen-gpios = <&gpio0 6 GPIO_ACTIVE_LOW>;
- scl-gpios = <&gpio0 5 GPIO_ACTIVE_HIGH>;
- sda-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
+panel: display@0 {
+ compatible = "tpo,tpg110";
+ reg = <0>;
+ spi-3wire;
+ /* 320 ns min period ~= 3 MHz */
+ spi-max-frequency = <3000000>;
+ /* Width and height from data sheet */
+ width-mm = <116>;
+ height-mm = <87>;
+ grestb-gpios = <&foo_gpio 5 GPIO_ACTIVE_LOW>;
backlight = <&bl>;
port {
nomadik_clcd_panel: endpoint {
- remote-endpoint = <&nomadik_clcd_pads>;
+ remote-endpoint = <&foo>;
};
};
-
- panel-timing {
- clock-frequency = <33200000>;
- hactive = <800>;
- hback-porch = <216>;
- hfront-porch = <40>;
- hsync-len = <1>;
- vactive = <480>;
- vback-porch = <35>;
- vfront-porch = <10>;
- vsync-len = <1>;
- };
};
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