Re: [PATCH v3 2/4] dt-bindings: gpio: add raspberry pi GPIO expander binding
From: Rob Herring <robh@kernel.org>
Date: 2018-01-29 16:11:34
Also in:
linux-arm-kernel, linux-gpio
On Tue, Jan 16, 2018 at 02:45:08PM +0200, Baruch Siach wrote:
quoted hunk ↗ jump to hunk
The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware over I2C. The firmware mailbox interface allows the ARM core to control the GPIO lines. Signed-off-by: Baruch Siach <baruch@tkos.co.il> --- v3: * Rename node name. v2: * Rename compatible string to raspberrypi,firmware-gpio --- .../bindings/gpio/raspberrypi,firmware-gpio.txt | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txtdiff --git a/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt new file mode 100644 index 000000000000..936dc59eba12 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt@@ -0,0 +1,24 @@ +Raspberry Pi GPIO expander + +The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The +firmware exposes a mailbox interface that allows the ARM core to control the +GPIO lines on the expander. + +Required properties: + +- compatible : Should be "raspberrypi,firmware-gpio" +- gpio-controller : Marks the device node as a gpio controller +- #gpio-cells : Should be two. The first cell is the pin number, and + the second cell is used to specify the gpio polarity: + 0 = active high + 1 = active low +- firmware : Reference to the RPi firmware device node + +Example: + +expgpio: gpio-expander {
Still not right. The correct generic node name is "gpio".
+ compatible = "raspberrypi,firmware-gpio"; + gpio-controller; + #gpio-cells = <2>; + firmware = <&firmware>;
Can you make this a child of the firmware node instead? Rob