[PATCH v2 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library
From: p.zabel@pengutronix.de (Philipp Zabel)
Date: 2016-07-13 07:27:31
Also in:
linux-devicetree, linux-pm
Am Mittwoch, den 13.07.2016, 10:06 +0800 schrieb Peter Chen:
quoted hunk ↗ jump to hunk
Add binding doc for generic power sequence library. 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,
I would replace "to let the device work normally" with "before the device can be enumerated [on the bus]" here.
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
As Joshua pointed out, is this even needed at all?
+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.
With the above two issues sorted out, Acked-by: Philipp Zabel <p.zabel@pengutronix.de> regards Philipp