From mboxrd@z Thu Jan 1 00:00:00 1970 From: hzpeterchen@gmail.com (Peter Chen) Date: Wed, 13 Jul 2016 16:42:50 +0800 Subject: [PATCH v2 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library In-Reply-To: <1468394851.3638.13.camel@pengutronix.de> References: <1468375610-18625-1-git-send-email-peter.chen@nxp.com> <1468375610-18625-2-git-send-email-peter.chen@nxp.com> <1468394851.3638.13.camel@pengutronix.de> Message-ID: <20160713084250.GB11863@shlinux2> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jul 13, 2016 at 09:27:31AM +0200, Philipp Zabel wrote: > Am Mittwoch, den 13.07.2016, 10:06 +0800 schrieb Peter Chen: > > Add binding doc for generic power sequence library. > > > > Signed-off-by: Peter Chen > > --- > > .../bindings/power/pwrseq/pwrseq-generic.txt | 53 ++++++++++++++++++++++ > > 1 file changed, 53 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..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. > Ok. > > 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? > If no, how we decide whether allocates pwrseq instance through pwrseq library or not? -- Best Regards, Peter Chen