2021-01-14 17:16:08

by Amelie Delaunay

Subject: [PATCH v2 1/2] dt-bindings: phy: phy-stm32-usbphyc: add #clock-cells required property

usbphyc provides a unique clock called ck_usbo_48m.
STM32 USB OTG needs a 48Mhz clock (utmifs_clk48) for Full-Speed operation.
ck_usbo_48m is a possible parent clock for USB OTG 48Mhz clock.

ck_usbo_48m is available as soon as the PLL is enabled.

Signed-off-by: Amelie Delaunay <[email protected]>
---
No change in v2.
---
.../devicetree/bindings/phy/phy-stm32-usbphyc.yaml | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
index 46df6786727a..4e4da64b8e01 100644
--- a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
+++ b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
@@ -51,6 +51,10 @@ properties:
vdda1v8-supply:
description: regulator providing 1V8 power supply to the PLL block

+ '#clock-cells':
+ description: number of clock cells for ck_usbo_48m consumer
+ const: 0
+
#Required child nodes:

patternProperties:
@@ -102,6 +106,7 @@ required:
- "#size-cells"
- vdda1v1-supply
- vdda1v8-supply
+ - '#clock-cells'
- usb-phy@0
- usb-phy@1

@@ -120,6 +125,7 @@ examples:
vdda1v8-supply = <&reg18>;
#address-cells = <1>;
#size-cells = <0>;
+ #clock-cells = <0>;

usbphyc_port0: usb-phy@0 {
reg = <0>;
--
2.17.1

2021-01-25 21:44:45

by Rob Herring (Arm)

Subject: Re: [PATCH v2 1/2] dt-bindings: phy: phy-stm32-usbphyc: add #clock-cells required property

On Thu, Jan 14, 2021 at 06:13:13PM +0100, Amelie Delaunay wrote:
> usbphyc provides a unique clock called ck_usbo_48m.
> STM32 USB OTG needs a 48Mhz clock (utmifs_clk48) for Full-Speed operation.
> ck_usbo_48m is a possible parent clock for USB OTG 48Mhz clock.
>
> ck_usbo_48m is available as soon as the PLL is enabled.
>
> Signed-off-by: Amelie Delaunay <[email protected]>
> ---
> No change in v2.
> ---
> .../devicetree/bindings/phy/phy-stm32-usbphyc.yaml | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
> index 46df6786727a..4e4da64b8e01 100644
> --- a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
> +++ b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
> @@ -51,6 +51,10 @@ properties:
> vdda1v8-supply:
> description: regulator providing 1V8 power supply to the PLL block
>
> + '#clock-cells':
> + description: number of clock cells for ck_usbo_48m consumer
> + const: 0
> +
> #Required child nodes:
>
> patternProperties:
> @@ -102,6 +106,7 @@ required:
> - "#size-cells"
> - vdda1v1-supply
> - vdda1v8-supply
> + - '#clock-cells'

You can't really make new properties required as it's not backwards
compatible. If things can never work without or the binding has never
been used, then you can. You just need to spell this out in the commit
msg.

> - usb-phy@0
> - usb-phy@1
>
> @@ -120,6 +125,7 @@ examples:
> vdda1v8-supply = <&reg18>;
> #address-cells = <1>;
> #size-cells = <0>;
> + #clock-cells = <0>;
>
> usbphyc_port0: usb-phy@0 {
> reg = <0>;
> --
> 2.17.1
>

2021-01-26 11:34:48

by Amelie Delaunay

Subject: Re: [PATCH v2 1/2] dt-bindings: phy: phy-stm32-usbphyc: add #clock-cells required property

Hi Rob,

On 1/25/21 10:40 PM, Rob Herring wrote:
> On Thu, Jan 14, 2021 at 06:13:13PM +0100, Amelie Delaunay wrote:
>> usbphyc provides a unique clock called ck_usbo_48m.
>> STM32 USB OTG needs a 48Mhz clock (utmifs_clk48) for Full-Speed operation.
>> ck_usbo_48m is a possible parent clock for USB OTG 48Mhz clock.
>>
>> ck_usbo_48m is available as soon as the PLL is enabled.
>>
>> Signed-off-by: Amelie Delaunay <[email protected]>
>> ---
>> No change in v2.
>> ---
>> .../devicetree/bindings/phy/phy-stm32-usbphyc.yaml | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
>> index 46df6786727a..4e4da64b8e01 100644
>> --- a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
>> +++ b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
>> @@ -51,6 +51,10 @@ properties:
>> vdda1v8-supply:
>> description: regulator providing 1V8 power supply to the PLL block
>>
>> + '#clock-cells':
>> + description: number of clock cells for ck_usbo_48m consumer
>> + const: 0
>> +
>> #Required child nodes:
>>
>> patternProperties:
>> @@ -102,6 +106,7 @@ required:
>> - "#size-cells"
>> - vdda1v1-supply
>> - vdda1v8-supply
>> + - '#clock-cells'
>
> You can't really make new properties required as it's not backwards
> compatible. If things can never work without or the binding has never
> been used, then you can. You just need to spell this out in the commit
> msg.
>

In fact things can work without this property. But I made this new
property required because in clock-bindings, #clock-cells property is a
required property for clock providers.

phy-stm32-usbphyc bindings are only used in stm32mp151.dtsi, which will
be updated with this new property as soon as this bindings will be reviewed.

I can remove this new property from required ones, but is it okay as
#clock-cells property is a required property for clock providers?

Regards,
Amelie

>> - usb-phy@0
>> - usb-phy@1
>>
>> @@ -120,6 +125,7 @@ examples:
>> vdda1v8-supply = <&reg18>;
>> #address-cells = <1>;
>> #size-cells = <0>;
>> + #clock-cells = <0>;
>>
>> usbphyc_port0: usb-phy@0 {
>> reg = <0>;
>> --
>> 2.17.1
>>