From: Peter Chen <hzpeterchen@gmail.com>
To: Joshua Clayton <stillcompiling@gmail.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>,
Peter Chen <peter.chen@nxp.com>,
gregkh@linuxfoundation.org, stern@rowland.harvard.edu,
ulf.hansson@linaro.org, broonie@kernel.org, sre@kernel.org,
robh+dt@kernel.org, shawnguo@kernel.org, k.kozlowski@samsung.com,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
pawel.moll@arm.com, mark.rutland@arm.com,
linux-usb@vger.kernel.org, arnd@arndb.de, s.hauer@pengutronix.de,
mail@maciej.szmigiero.name, troy.kisky@boundarydevices.com,
festevam@gmail.com, oscar@naiandei.net, stephen.boyd@linaro.org,
linux-pm@vger.kernel.org
Subject: Re: [PATCH v2 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library
Date: Thu, 14 Jul 2016 14:36:27 +0800 [thread overview]
Message-ID: <20160714063627.GA28730@shlinux2> (raw)
In-Reply-To: <5786CCA6.2090709@gmail.com>
On Wed, Jul 13, 2016 at 04:20:06PM -0700, Joshua Clayton wrote:
>
>
> On 07/13/2016 01:42 AM, Peter Chen wrote:
> > 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 <peter.chen@nxp.com>
> >>> ---
> >>> .../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?
> >
> The pwrseq driver is Linux specific. The dts is supposed to be OS agnostic.
> It seems to me that If a driver supports pwrseq and the dts elements
> are there, it should use them, e.g. if there is a clock, enable the clock.
> if there is a reset gpio then take the device into and out of reset during probe.
>
I agree with you, will delete this property.
--
Best Regards,
Peter Chen
WARNING: multiple messages have this Message-ID (diff)
From: hzpeterchen@gmail.com (Peter Chen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library
Date: Thu, 14 Jul 2016 14:36:27 +0800 [thread overview]
Message-ID: <20160714063627.GA28730@shlinux2> (raw)
In-Reply-To: <5786CCA6.2090709@gmail.com>
On Wed, Jul 13, 2016 at 04:20:06PM -0700, Joshua Clayton wrote:
>
>
> On 07/13/2016 01:42 AM, Peter Chen wrote:
> > 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 <peter.chen@nxp.com>
> >>> ---
> >>> .../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?
> >
> The pwrseq driver is Linux specific. The dts is supposed to be OS agnostic.
> It seems to me that If a driver supports pwrseq and the dts elements
> are there, it should use them, e.g. if there is a clock, enable the clock.
> if there is a reset gpio then take the device into and out of reset during probe.
>
I agree with you, will delete this property.
--
Best Regards,
Peter Chen
next prev parent reply other threads:[~2016-07-14 6:44 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-13 2:06 [PATCH v2 0/6] power: add power sequence library Peter Chen
2016-07-13 2:06 ` Peter Chen
2016-07-13 2:06 ` [PATCH v2 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic " Peter Chen
2016-07-13 2:06 ` Peter Chen
2016-07-13 7:27 ` Philipp Zabel
2016-07-13 7:27 ` Philipp Zabel
2016-07-13 8:42 ` Peter Chen
2016-07-13 8:42 ` Peter Chen
2016-07-13 23:20 ` Joshua Clayton
2016-07-13 23:20 ` Joshua Clayton
2016-07-14 6:36 ` Peter Chen [this message]
2016-07-14 6:36 ` Peter Chen
2016-07-16 22:30 ` Rob Herring
2016-07-16 22:30 ` Rob Herring
2016-07-18 3:04 ` Peter Chen
2016-07-18 3:04 ` Peter Chen
2016-07-13 2:06 ` [PATCH v2 2/6] power: add " Peter Chen
2016-07-13 2:06 ` Peter Chen
2016-07-13 2:06 ` [PATCH v2 3/6] binding-doc: usb: usb-device: add optional properties for power sequence Peter Chen
2016-07-13 2:06 ` Peter Chen
2016-07-16 22:31 ` Rob Herring
2016-07-16 22:31 ` Rob Herring
2016-07-18 2:55 ` Peter Chen
2016-07-18 2:55 ` Peter Chen
2016-07-13 2:06 ` [PATCH v2 4/6] usb: core: add power sequence handling for USB devices Peter Chen
2016-07-13 2:06 ` Peter Chen
2016-07-13 2:06 ` [PATCH v2 6/6] ARM: dts: imx6qdl-udoo.dtsi: fix onboard USB HUB property Peter Chen
2016-07-13 2:06 ` Peter Chen
[not found] ` <1468375610-18625-1-git-send-email-peter.chen-3arQi8VN3Tc@public.gmane.org>
2016-07-13 2:06 ` [PATCH v2 5/6] usb: chipidea: let chipidea core device of_node equal's glue layer device of_node Peter Chen
2016-07-13 2:06 ` Peter Chen
2016-08-23 10:22 ` [PATCH v2 0/6] power: add power sequence library Vaibhav Hiremath
2016-08-23 10:22 ` Vaibhav Hiremath
2016-08-23 10:27 ` Vaibhav Hiremath
2016-08-23 10:27 ` Vaibhav Hiremath
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