[PATCH v2 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library
flat view
From: robh@kernel.org (Rob Herring)
Date: 2016-07-16 22:30:57
Also in:
linux-devicetree, linux-pm
On Wed, Jul 13, 2016 at 10:06:45AM +0800, Peter Chen wrote:
Add binding doc for generic power sequence library.
I'd written a review on last version, but forgot to send it out. Anyway, I mostly had the same comments as Philipp and Joshua. A couple of things they missed...
quoted hunk ↗ jump to hunk
Signed-off-by: Peter Chen <redacted> --- .../bindings/power/pwrseq/pwrseq-generic.txt | 53 ++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txtdiff --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..186c58c --- /dev/null +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt@@ -0,0 +1,53 @@ +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. +- 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>; + hub: genesys at 1 {
genesys: hub at 1
quoted hunk ↗ jump to hunk
+ compatible = "usb5e3,608"; + reg = <1>; + + power-sequence; + 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>; + ethernet: asix at 1 {
asix: ethernet at 1
+ compatible = "usbb95,1708"; + reg = <1>; + + power-sequence; + clocks = <&clks IMX6SX_CLK_IPG>; + reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */ + reset-duration-us = <15>; + }; + }; +}; -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel