Re: [PATCH 1/3] pinctrl: Broadcom NSP GPIO-a device tree bindings

From: Rob Herring
Date: Wed Dec 02 2015 - 10:07:55 EST


On Tue, Dec 01, 2015 at 11:46:38PM -0500, Yendapally Reddy Dhananjaya Reddy wrote:
> Device tree binding documentation for Broadcom NSP GPIO-a driver

Bindings are for h/w, not drivers...

>
> Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yrdreddy@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/pinctrl/brcm,nsp-gpio.txt | 80 ++++++++++++++++++++++
> 1 file changed, 80 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt b/Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt
> new file mode 100644
> index 0000000..bea4211
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt
> @@ -0,0 +1,80 @@
> +Broadcom Northstar plus (NSP) GPIO/PINCONF Controller
> +
> +Required properties:
> +- compatible:
> + Must be "brcm,nsp-gpio-a"
> +
> +- reg:
> + Should contain the register physical address and length for each of
> + GPIO base, IO control registers
> +
> +- #gpio-cells:
> + Must be two. The first cell is the GPIO pin number (within the
> + controller's pin space) and the second cell is used for the following:
> + bit[0]: polarity (0 for active high and 1 for active low)
> +
> +- gpio-controller:
> + Specifies that the node is a GPIO controller
> +
> +- ngpios:
> + Number of gpios supported (58x25 supports 32 and 58x23 supports 24)

2 chips? You should have 2 compatible strings. I think this is incorrect
use of ngpios which AIUI is not for how many lines there are, but how
many can be used (e.g. not reserved).

> +
> +Optional properties:
> +- interrupts:
> + Interrupt ID
> +
> +- interrupt-controller:
> + Specifies that the node is an interrupt controller
> +
> +- gpio-ranges:
> + Specifies the mapping between gpio controller and pin-controllers pins.
> + This requires 4 fields in cells defined as -
> + 1. Phandle of pin-controller.
> + 2. GPIO base pin offset.
> + 3 Pin-control base pin offset.
> + 4. number of gpio pins which are linearly mapped from pin base.
> +
> +Supported generic PINCONF properties in child nodes:
> +- pins:
> + The list of pins (within the controller's own pin space) that properties
> + in the node apply to. Pin names are "gpio-<pin>"
> +
> +- bias-disable:
> + Disable pin bias
> +
> +- bias-pull-up:
> + Enable internal pull up resistor
> +
> +- bias-pull-down:
> + Enable internal pull down resistor
> +
> +- drive-strength:
> + Valid drive strength values include 2, 4, 6, 8, 10, 12, 14, 16 (mA)
> +
> +Example:
> +
> + gpioa: gpio-a@18000020 {

node names are preferred to be generic, so just "gpio@..."

> + compatible = "brcm,nsp-gpio-a";
> + reg = <0x18000020 0x100>,
> + <0x1803f1c4 0x1c>;
> + #gpio-cells = <2>;
> + gpio-controller;
> + ngpios = <32>;
> + gpio-ranges = <&pinctrl 0 0 31>;
> + interrupt-controller;
> + interrupts = <GIC_SPI 85 IRQ_TYPE_LEVEL_HIGH>;
> +
> + /* Hog a few default settings */
> + pinctrl-names = "default";
> + pinctrl-0 = <&led>;
> + led: led {
> + pins = "gpio-1";
> + bias-pull-up;
> + };
> +
> + pwr: pwr {
> + gpio-hog;
> + gpios = <3 1>;
> + output-high;
> + };
> + };
> --
> 2.1.0
>
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