Messages in this thread Patch in this message | | | From | Peter Chen <> | Subject | [PATCH v15 1/7] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library | Date | Tue, 13 Jun 2017 09:59:20 +0800 |
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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> Acked-by: Rob Herring <robh@kernel.org> --- .../bindings/power/pwrseq/pwrseq-generic.txt | 48 ++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
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..ebf0d47 --- /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 clocks 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 = <®_usb_otg1_vbus>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_usb_otg1_id>; + status = "okay"; + + #address-cells = <1>; + #size-cells = <0>; + genesys: hub@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@1 { + compatible = "usbb95,1708"; + reg = <1>; + + clocks = <&clks IMX6SX_CLK_IPG>; + reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */ + reset-duration-us = <15>; + }; + }; +}; -- 2.7.4
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