| Message ID | IA1PR20MB4953BB6E71CA3216E652E8B8BBA02@IA1PR20MB4953.namprd20.prod.outlook.com |
|---|---|
| State | New |
| Headers | show |
| Series | dt-bindings: pincfg-node: Add "input-schmitt" property | expand |
On Mon, Jul 15, 2024 at 05:19:41PM GMT, Conor Dooley wrote: > On Mon, Jul 15, 2024 at 05:55:28PM +0800, Inochi Amaoto wrote: > > On Mon, Jul 15, 2024 at 11:21:25AM GMT, Krzysztof Kozlowski wrote: > > > On 14/07/2024 13:28, Inochi Amaoto wrote: > > > > On Sophgo CV18XX platform, threshold strength of schmitt trigger can > > > > be configured. As this standard property is already supported by the > > > > common pinconf code. Add "input-schmitt" property in pincfg-node.yaml > > > > so that other platforms requiring such feature can make use of this > > > > property. > > > > > > > > Signed-off-by: Inochi Amaoto <inochiama@outlook.com> > > > > --- > > > > Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml > > > > index d0af21a564b4..e838fcac7f2a 100644 > > > > --- a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml > > > > +++ b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml > > > > @@ -88,6 +88,10 @@ properties: > > > > description: disable input on pin (no effect on output, such as > > > > disabling an input buffer) > > > > > > > > + input-schmitt: > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > + description: threshold strength for schmitt-trigger > > > > > > Strength in which units? This should have proper property name suffix. > > > > > > > I think it should be mV. Using voltage may leads to decimal. > > The standard suffix for voltage is "-microvolts", so no issues with > decimals :) And with a standard suffix, the $ref can be dropped. Yeah, I have seen the "-microvolts", but I does not think add standard suffix is a good idea, as "input-schmitt" is a standard pinconf attribute. The only thing confused me is that the description of PIN_CONFIG_INPUT_SCHMITT in include/linux/pinctrl/pinconf-generic.h says it just uses an custom format as argument. So I think it may keep something generic?
On Tue, Jul 16, 2024 at 08:16:59AM GMT, Krzysztof Kozlowski wrote: > On 16/07/2024 04:16, Inochi Amaoto wrote: > > On Mon, Jul 15, 2024 at 05:19:41PM GMT, Conor Dooley wrote: > >> On Mon, Jul 15, 2024 at 05:55:28PM +0800, Inochi Amaoto wrote: > >>> On Mon, Jul 15, 2024 at 11:21:25AM GMT, Krzysztof Kozlowski wrote: > >>>> On 14/07/2024 13:28, Inochi Amaoto wrote: > >>>>> On Sophgo CV18XX platform, threshold strength of schmitt trigger can > >>>>> be configured. As this standard property is already supported by the > >>>>> common pinconf code. Add "input-schmitt" property in pincfg-node.yaml > >>>>> so that other platforms requiring such feature can make use of this > >>>>> property. > >>>>> > >>>>> Signed-off-by: Inochi Amaoto <inochiama@outlook.com> > >>>>> --- > >>>>> Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml | 4 ++++ > >>>>> 1 file changed, 4 insertions(+) > >>>>> > >>>>> diff --git a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml > >>>>> index d0af21a564b4..e838fcac7f2a 100644 > >>>>> --- a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml > >>>>> +++ b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml > >>>>> @@ -88,6 +88,10 @@ properties: > >>>>> description: disable input on pin (no effect on output, such as > >>>>> disabling an input buffer) > >>>>> > >>>>> + input-schmitt: > >>>>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>>>> + description: threshold strength for schmitt-trigger > >>>> > >>>> Strength in which units? This should have proper property name suffix. > >>>> > >>> > >>> I think it should be mV. Using voltage may leads to decimal. > >> > >> The standard suffix for voltage is "-microvolts", so no issues with > >> decimals :) And with a standard suffix, the $ref can be dropped. > > > > Yeah, I have seen the "-microvolts", but I does not think add standard > > suffix is a good idea, as "input-schmitt" is a standard pinconf attribute. > > > > The only thing confused me is that the description of PIN_CONFIG_INPUT_SCHMITT > > in include/linux/pinctrl/pinconf-generic.h says it just uses an custom > > You cannot add binding based on argument "I don't want to change kernel > code", so sorry, but it does not really matter whatever pinctrl has > undocumented. > Yes, that is true. Even if not considering the kernel code, I think adding something generic like "input-schmit-xxx" is useful as input schmitt trigger has threshold strength. And if we want to configure it, it should have a value. As the original "input-schmitt" seems to be meaningless, I will take Conor's advice and add "input-schmitt-micorvolts" attribute to handle this. Regards, Inochi
diff --git a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml index d0af21a564b4..e838fcac7f2a 100644 --- a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml +++ b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml @@ -88,6 +88,10 @@ properties: description: disable input on pin (no effect on output, such as disabling an input buffer) + input-schmitt: + $ref: /schemas/types.yaml#/definitions/uint32 + description: threshold strength for schmitt-trigger + input-schmitt-enable: type: boolean description: enable schmitt-trigger mode
On Sophgo CV18XX platform, threshold strength of schmitt trigger can be configured. As this standard property is already supported by the common pinconf code. Add "input-schmitt" property in pincfg-node.yaml so that other platforms requiring such feature can make use of this property. Signed-off-by: Inochi Amaoto <inochiama@outlook.com> --- Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml | 4 ++++ 1 file changed, 4 insertions(+) -- 2.45.2