Re: [PATCH 2/3] dt-bindings: gpio: Add binding document for xylon logicvc-gpio
From: Rob Herring <robh@kernel.org>
Date: 2019-09-13 14:36:34
Also in:
linux-devicetree, lkml
On Tue, Sep 10, 2019 at 05:28:54PM +0200, Paul Kocialkowski wrote:
The Xylon LogiCVC display controller exports some GPIOs, which are exposed as a dedicated driver. This introduces the associated device-tree bindings documentation. Signed-off-by: Paul Kocialkowski <redacted> --- .../bindings/gpio/xylon,logicvc-gpio.txt | 48 +++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.txt
Please consider using the new DT schema format.
quoted hunk ↗ jump to hunk
diff --git a/Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.txt b/Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.txt new file mode 100644 index 000000000000..4835659cb90b --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.txt@@ -0,0 +1,48 @@ +Xylon LogiCVC GPIO controller + +The Xylon LogiCVC is a display controller that contains a number of GPIO pins, +meant to be used for controlling display-related signals. + +In practice, the GPIOs can be used for any purpose they might be needed for. + +The controller exposes GPIOs from the display and power control registers, +which are mapped by the driver as follows: +- GPIO[4:0] (display control) mapped to index 0-4 +- EN_BLIGHT (power control) mapped to index 5 +- EN_VDD (power control) mapped to index 6 +- EN_VEE (power control) mapped to index 7 +- V_EN (power control) mapped to index 8 + +The driver was implemented and tested for version 3.02.a of the controller, +but should be compatible with version 4 as well. + +Required properties: +- compatible: Should contain "xylon,logicvc-3.02.a-gpio". +- gpio-controller: Marks the device node as a gpio controller. +- #gpio-cells: Should be 2. The first cell is the pin number and + the second cell is used to specify the gpio polarity: + 0 = Active high, + 1 = Active low.
No need to define these standard flags again here.
+- gpio,syscon-dev: Syscon phandle representing the logicvc instance.
Don't need this. It's the parent.
+
+Example:
+
+ logicvc: logicvc@43c00000 {
+ compatible = "syscon", "simple-mfd";This device needs a device specific compatible. These 2 alone are not desired. Please define everything that's in the chip as much as you can.
+ reg = <0x43c00000 0x6000>;
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ logicvc_gpio: display-gpio@40 {Use standard node names: gpio@40 You may not even need a child node here. It depends on what other child nodes you have and whether they have their own DT resources.
+ compatible = "xylon,logicvc-3.02.a-gpio"; + reg = <0x40 0x40>; + gpio-controller; + #gpio-cells = <2>; + gpio,syscon-dev = <&logicvc>; + }; + }; + +Note: the device-tree node should either be declared as a child of the logicvc +syscon node or the syscon node should be precised with the gpio,syscon-dev +property. Both are shown in the example above.
Why? Just pick one and a child node is the preference.
-- 2.23.0