| Message ID | 1468375610-18625-2-git-send-email-peter.chen@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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. > 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
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?
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. Can you see a problem with that approach?
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.
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... > > 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, 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@1 { genesys: hub@1 > + 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@1 { asix: ethernet@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@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Sat, Jul 16, 2016 at 05:30:57PM -0500, Rob Herring wrote: > 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... > > > > > 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, 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@1 { > > genesys: hub@1 > > > + 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@1 { > > asix: ethernet@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>; > > + }; > > + }; > > +}; Will change, thanks.
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, 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@1 { + 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@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>; + }; + }; +};
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