From mboxrd@z Thu Jan 1 00:00:00 1970 From: peter.chen@nxp.com (Peter Chen) Date: Thu, 7 Jul 2016 17:14:47 +0800 Subject: [PATCH 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library In-Reply-To: <1467882892-27589-1-git-send-email-peter.chen@nxp.com> References: <1467882892-27589-1-git-send-email-peter.chen@nxp.com> Message-ID: <1467882892-27589-2-git-send-email-peter.chen@nxp.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Add binding doc for generic power sequence library. Signed-off-by: Peter Chen --- .../bindings/power/pwrseq/pwrseq-generic.txt | 56 ++++++++++++++++++++++ 1 file changed, 56 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..4b23834 --- /dev/null +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt @@ -0,0 +1,56 @@ +The generic power sequence library + +Some hard-wired USB/MMC devices need to do power sequence to let the +device work normally, the typical power sequence like: enable USB +PHY clock, toggle reset pin, etc. But current Linux USB driver +lacks of such code to do it, it may cause some hard-wired USB 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 USB +bus. + +The power sequence properties is under the device node. + +Required properties: +- power-sequence: this device needs to do power sequence before enumeration + +Optional properties: +- clocks: the input clock for device. +- clock-name: must be "pwrseq-clk" +- pwrseq-reset-gpios: Should specify the GPIO for reset. +- pwrseq-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>; + hub: genesys at 1 { + compatible = "usb5e3,608"; + reg = <1>; + + power-sequence; + clocks = <&clks IMX6SX_CLK_CKO>; + clock-names = "pwrseq-clk"; + pwrseq-reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */ + pwrseq-reset-duration-us = <10>; + + #address-cells = <1>; + #size-cells = <0>; + ethernet: asix at 1 { + compatible = "usbb95,1708"; + reg = <1>; + + power-sequence; + clocks = <&clks IMX6SX_CLK_IPG>; + clock-names = "pwrseq-clk"; + pwrseq-reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */ + pwrseq-reset-duration-us = <15>; + }; + }; +}; -- 1.9.1