[PATCH v3 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library

Rob Herring
2016-07-29T21:09:43Z

On Wed, Jul 20, 2016 at 05:40:24PM +0800, Peter Chen wrote:
> Add binding doc for generic power sequence library.
>
> Signed-off-by: Peter Chen <peter.chen@nxp.com>
> Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> .../bindings/power/pwrseq/pwrseq-generic.txt | 48 ++++++++++++++++++++++
> 1 file changed, 48 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt

Acked-by: Rob Herring <robh@kernel.org>

>
> diff --git a/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
> new file mode 100644
> index 0000000..48bb3e1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
> @@ -0,0 +1,48 @@
> +The generic power sequence library
> +
> +Some hard-wired devices (eg USB/MMC) need to do power sequence before
> +the device can be enumerated on the bus, the typical power sequence
> +like: enable USB PHY clock, toggle reset pin, etc. But current
> +Linux device driver lacks of such code to do it, it may cause some
> +hard-wired devices works abnormal or can't be recognized by
> +controller at all. The power sequence will be done before this device
> +can be found at the bus.
> +
> +The power sequence properties is under the device node.
> +
> +Optional properties:
> +- clocks: the input clock for device.
> +- reset-gpios: Should specify the GPIO for reset.
> +- reset-duration-us: the duration in microsecond for assert reset signal.
> +
> +Below is the example of USB power sequence properties on USB device
> +nodes which have two level USB hubs.
> +
> +&usbotg1 {
> + vbus-supply = <&reg_usb_otg1_vbus>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_usb_otg1_id>;
> + status = "okay";
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> + genesys: hub at 1 {
> + compatible = "usb5e3,608";
> + reg = <1>;
> +
> + clocks = <&clks IMX6SX_CLK_CKO>;
> + reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
> + reset-duration-us = <10>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> + asix: ethernet at 1 {
> + compatible = "usbb95,1708";
> + reg = <1>;
> +
> + clocks = <&clks IMX6SX_CLK_IPG>;
> + reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */
> + reset-duration-us = <15>;
> + };
> + };
> +};
> --
> 1.9.1
>