diff mbox

[1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library

Message ID 1467882892-27589-2-git-send-email-peter.chen@nxp.com
State Changes Requested, archived
Headers show

Commit Message

Peter Chen July 7, 2016, 9:14 a.m. UTC
Add binding doc for generic power sequence library.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
 .../bindings/power/pwrseq/pwrseq-generic.txt       | 56 ++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt

Comments

Philipp Zabel July 7, 2016, 9:47 a.m. UTC | #1
Am Donnerstag, den 07.07.2016, 17:14 +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       | 56 ++++++++++++++++++++++
>  1 file changed, 56 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..4b23834
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
> @@ -0,0 +1,56 @@
> +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.
> +- clock-name: must be "pwrseq-clk"

The "-clk" in the clock name is redundant.

> +- pwrseq-reset-gpios: Should specify the GPIO for reset.
> +- pwrseq-reset-duration-us: the duration in microsecond for assert reset signal.

I understand you want to make it explicit that this GPIO is for the
pwrseq library, but are we really gaining anything over just calling
these reset-gpios and reset-duration-us?
The same applies to the clock name above.

> +Below is the example of USB power sequence properties on USB device
> +nodes which have two level USB hubs.
> +
> +&usbotg1 {
> +	vbus-supply = <&reg_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>;
> +		clock-names = "pwrseq-clk";
> +		pwrseq-reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
> +		pwrseq-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>;
> +			clock-names = "pwrseq-clk";
> +			pwrseq-reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */
> +			pwrseq-reset-duration-us = <15>;
> +		};

This looks weird. The hub and ethernet chips don't have "pwrseq" clock
and reset input pins. I'd remove the clock-names and pwrseq- reset
prefix.

regards
Philipp

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Joshua Clayton July 7, 2016, 11:53 p.m. UTC | #2
On 07/07/2016 02:47 AM, Philipp Zabel wrote:
> Am Donnerstag, den 07.07.2016, 17:14 +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       | 56 ++++++++++++++++++++++
>>  1 file changed, 56 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..4b23834
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
>> @@ -0,0 +1,56 @@
>> +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.
>> +- clock-name: must be "pwrseq-clk"
> The "-clk" in the clock name is redundant.
>
>> +- pwrseq-reset-gpios: Should specify the GPIO for reset.
>> +- pwrseq-reset-duration-us: the duration in microsecond for assert reset signal.
> I understand you want to make it explicit that this GPIO is for the
> pwrseq library, but are we really gaining anything over just calling
> these reset-gpios and reset-duration-us?
> The same applies to the clock name above.
using  reset-gpios makes sense to  me too.
The above "power-sequence" might then be better called "reset-on-init",
But really, if a device has a reset gpio shouldn't the default behavior be to
reset it on boot and when coming back from sleep?
Is a special property even needed?
>
>> +Below is the example of USB power sequence properties on USB device
>> +nodes which have two level USB hubs.
>> +
>> +&usbotg1 {
>> +	vbus-supply = <&reg_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>;
>> +		clock-names = "pwrseq-clk";
>> +		pwrseq-reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
>> +		pwrseq-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>;
>> +			clock-names = "pwrseq-clk";
>> +			pwrseq-reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */
>> +			pwrseq-reset-duration-us = <15>;
>> +		};
> This looks weird. The hub and ethernet chips don't have "pwrseq" clock
> and reset input pins. I'd remove the clock-names and pwrseq- reset
> prefix.
>
> regards
> Philipp
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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Peter Chen July 8, 2016, 2:37 a.m. UTC | #3
On Thu, Jul 07, 2016 at 11:47:14AM +0200, Philipp Zabel wrote:
> Am Donnerstag, den 07.07.2016, 17:14 +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       | 56 ++++++++++++++++++++++
> >  1 file changed, 56 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..4b23834
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
> > @@ -0,0 +1,56 @@
> > +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.
> > +- clock-name: must be "pwrseq-clk"
> 
> The "-clk" in the clock name is redundant.
> 
> > +- pwrseq-reset-gpios: Should specify the GPIO for reset.
> > +- pwrseq-reset-duration-us: the duration in microsecond for assert reset signal.
> 
> I understand you want to make it explicit that this GPIO is for the
> pwrseq library, but are we really gaining anything over just calling
> these reset-gpios and reset-duration-us?
> The same applies to the clock name above.
> 
> > +Below is the example of USB power sequence properties on USB device
> > +nodes which have two level USB hubs.
> > +
> > +&usbotg1 {
> > +	vbus-supply = <&reg_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>;
> > +		clock-names = "pwrseq-clk";
> > +		pwrseq-reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
> > +		pwrseq-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>;
> > +			clock-names = "pwrseq-clk";
> > +			pwrseq-reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */
> > +			pwrseq-reset-duration-us = <15>;
> > +		};
> 
> This looks weird. The hub and ethernet chips don't have "pwrseq" clock
> and reset input pins. I'd remove the clock-names and pwrseq- reset
> prefix.
> 

I agree with you, and will keep property name like last version [1].
Peter Chen July 8, 2016, 2:39 a.m. UTC | #4
On Thu, Jul 07, 2016 at 04:53:07PM -0700, Joshua Clayton wrote:
> 
> 
> On 07/07/2016 02:47 AM, Philipp Zabel wrote:
> > Am Donnerstag, den 07.07.2016, 17:14 +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       | 56 ++++++++++++++++++++++
> >>  1 file changed, 56 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..4b23834
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
> >> @@ -0,0 +1,56 @@
> >> +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.
> >> +- clock-name: must be "pwrseq-clk"
> > The "-clk" in the clock name is redundant.
> >
> >> +- pwrseq-reset-gpios: Should specify the GPIO for reset.
> >> +- pwrseq-reset-duration-us: the duration in microsecond for assert reset signal.
> > I understand you want to make it explicit that this GPIO is for the
> > pwrseq library, but are we really gaining anything over just calling
> > these reset-gpios and reset-duration-us?
> > The same applies to the clock name above.
> using  reset-gpios makes sense to  me too.
> The above "power-sequence" might then be better called "reset-on-init",
> But really, if a device has a reset gpio shouldn't the default behavior be to
> reset it on boot and when coming back from sleep?
> Is a special property even needed?

The power sequence does not include reset process only, it may include clock
and power as well.
diff mbox

Patch

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..4b23834
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt
@@ -0,0 +1,56 @@ 
+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.
+- clock-name: must be "pwrseq-clk"
+- pwrseq-reset-gpios: Should specify the GPIO for reset.
+- pwrseq-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 = <&reg_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>;
+		clock-names = "pwrseq-clk";
+		pwrseq-reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
+		pwrseq-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>;
+			clock-names = "pwrseq-clk";
+			pwrseq-reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */
+			pwrseq-reset-duration-us = <15>;
+		};
+	};
+};