71 lines
2.0 KiB
Plaintext
71 lines
2.0 KiB
Plaintext
TPO TPG110 Panel
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================
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This panel driver is a component that acts as an intermediary
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between an RGB output and a variety of panels. The panel
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driver is strapped up in electronics to the desired resolution
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and other properties, and has a control interface over 3WIRE
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SPI. By talking to the TPG110 over SPI, the strapped properties
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can be discovered and the hardware is therefore mostly
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self-describing.
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+--------+
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SPI -> | TPO | -> physical display
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RGB -> | TPG110 |
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+--------+
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If some electrical strap or alternate resolution is desired,
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this can be set up by taking software control of the display
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over the SPI interface. The interface can also adjust
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for properties of the display such as gamma correction and
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certain electrical driving levels.
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The TPG110 does not know the physical dimensions of the panel
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connected, so this needs to be specified in the device tree.
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It requires a GPIO line for control of its reset line.
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The serial protocol has line names that resemble I2C but the
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protocol is not I2C but 3WIRE SPI.
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Required properties:
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- compatible : one of:
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"ste,nomadik-nhk15-display", "tpo,tpg110"
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"tpo,tpg110"
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- grestb-gpios : panel reset GPIO
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- width-mm : see display/panel/panel-common.txt
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- height-mm : see display/panel/panel-common.txt
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The device needs to be a child of an SPI bus, see
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spi/spi-bus.txt. The SPI child must set the following
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properties:
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- spi-3wire
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- spi-max-frequency = <3000000>;
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as these are characteristics of this device.
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The device node can contain one 'port' child node with one child
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'endpoint' node, according to the bindings defined in
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media/video-interfaces.txt. This node should describe panel's video bus.
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Example
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-------
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panel: display@0 {
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compatible = "tpo,tpg110";
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reg = <0>;
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spi-3wire;
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/* 320 ns min period ~= 3 MHz */
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spi-max-frequency = <3000000>;
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/* Width and height from data sheet */
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width-mm = <116>;
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height-mm = <87>;
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grestb-gpios = <&foo_gpio 5 GPIO_ACTIVE_LOW>;
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backlight = <&bl>;
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port {
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nomadik_clcd_panel: endpoint {
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remote-endpoint = <&foo>;
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};
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};
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};
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