| Message ID | 20220331125818.3776912-4-fabiobaltieri@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add channel type support to pwm-cros-ec | expand |
On Thu, Mar 31, 2022 at 12:58:17PM +0000, Fabio Baltieri wrote: > Update google,cros-ec-pwm node documentation to mention the > google,use_pwm_type property. > > Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> > --- > .../devicetree/bindings/pwm/google,cros-ec-pwm.yaml | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > index 4cfbffd8414a..9c895c990ed8 100644 > --- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > +++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > @@ -19,6 +19,12 @@ description: | > properties: > compatible: > const: google,cros-ec-pwm > + > + google,use-pwm-type: > + description: > + Use PWM types (CROS_EC_PWM_DT_<...>) instead of generic channels. > + type: boolean Either do a new compatible string if the cell interpretation is mutually exclusive (channel number vs. type) or split the number space for the 1st cell between type and channel number. IOW, set a bit (31?) to signify the number is a type, not a channel. Rob
Hi Rob, On Wed, Apr 06, 2022 at 10:41:45AM -0500, Rob Herring wrote: > On Thu, Mar 31, 2022 at 12:58:17PM +0000, Fabio Baltieri wrote: > > Update google,cros-ec-pwm node documentation to mention the > > google,use_pwm_type property. > > > > Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> > > --- > > .../devicetree/bindings/pwm/google,cros-ec-pwm.yaml | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > index 4cfbffd8414a..9c895c990ed8 100644 > > --- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > +++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > @@ -19,6 +19,12 @@ description: | > > properties: > > compatible: > > const: google,cros-ec-pwm > > + > > + google,use-pwm-type: > > + description: > > + Use PWM types (CROS_EC_PWM_DT_<...>) instead of generic channels. > > + type: boolean > > Either do a new compatible string if the cell interpretation is mutually > exclusive (channel number vs. type) or split the number space for the > 1st cell between type and channel number. IOW, set a bit (31?) to > signify the number is a type, not a channel. Split the number space was my first (tentative) implementation as well, but it turns out that the PWM subsystem really wants channels to be zero-based[1], so I don't think flags or bitmasks are really an option. New compatible sounds good though, I'll rework a v3 with that change. Thanks! Fabio [1] https://elixir.bootlin.com/linux/v5.17/source/drivers/pwm/core.c#L423
On Thu, Apr 07, 2022 at 02:38:55PM +0000, Fabio Baltieri wrote: > Hi Rob, > > On Wed, Apr 06, 2022 at 10:41:45AM -0500, Rob Herring wrote: > > On Thu, Mar 31, 2022 at 12:58:17PM +0000, Fabio Baltieri wrote: > > > Update google,cros-ec-pwm node documentation to mention the > > > google,use_pwm_type property. > > > > > > Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> > > > --- > > > .../devicetree/bindings/pwm/google,cros-ec-pwm.yaml | 6 ++++++ > > > 1 file changed, 6 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > > index 4cfbffd8414a..9c895c990ed8 100644 > > > --- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > > +++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > > @@ -19,6 +19,12 @@ description: | > > > properties: > > > compatible: > > > const: google,cros-ec-pwm > > > + > > > + google,use-pwm-type: > > > + description: > > > + Use PWM types (CROS_EC_PWM_DT_<...>) instead of generic channels. > > > + type: boolean > > > > Either do a new compatible string if the cell interpretation is mutually > > exclusive (channel number vs. type) or split the number space for the > > 1st cell between type and channel number. IOW, set a bit (31?) to > > signify the number is a type, not a channel. > > Split the number space was my first (tentative) implementation as well, > but it turns out that the PWM subsystem really wants channels to be > zero-based[1], so I don't think flags or bitmasks are really an option. Fix the PWM subsystem then... > New compatible sounds good though, I'll rework a v3 with that change. > > Thanks! > Fabio > > [1] https://elixir.bootlin.com/linux/v5.17/source/drivers/pwm/core.c#L423 > > -- > Fabio Baltieri
On Thu, Apr 07, 2022 at 11:49:09AM -0500, Rob Herring wrote: > On Thu, Apr 07, 2022 at 02:38:55PM +0000, Fabio Baltieri wrote: > > Hi Rob, > > > > On Wed, Apr 06, 2022 at 10:41:45AM -0500, Rob Herring wrote: > > > On Thu, Mar 31, 2022 at 12:58:17PM +0000, Fabio Baltieri wrote: > > > > Update google,cros-ec-pwm node documentation to mention the > > > > google,use_pwm_type property. > > > > > > > > Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> > > > > --- > > > > .../devicetree/bindings/pwm/google,cros-ec-pwm.yaml | 6 ++++++ > > > > 1 file changed, 6 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > > > index 4cfbffd8414a..9c895c990ed8 100644 > > > > --- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > > > +++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml > > > > @@ -19,6 +19,12 @@ description: | > > > > properties: > > > > compatible: > > > > const: google,cros-ec-pwm > > > > + > > > > + google,use-pwm-type: > > > > + description: > > > > + Use PWM types (CROS_EC_PWM_DT_<...>) instead of generic channels. > > > > + type: boolean > > > > > > Either do a new compatible string if the cell interpretation is mutually > > > exclusive (channel number vs. type) or split the number space for the > > > 1st cell between type and channel number. IOW, set a bit (31?) to > > > signify the number is a type, not a channel. > > > > Split the number space was my first (tentative) implementation as well, > > but it turns out that the PWM subsystem really wants channels to be > > zero-based[1], so I don't think flags or bitmasks are really an option. > > Fix the PWM subsystem then... It's a good design decision, allows for probe time validation and a good debugfs interface, I'm happy to have this feature comply with it. > > > New compatible sounds good though, I'll rework a v3 with that change. > > > > Thanks! > > Fabio > > > > [1] https://elixir.bootlin.com/linux/v5.17/source/drivers/pwm/core.c#L423 > > > > -- > > Fabio Baltieri
diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml index 4cfbffd8414a..9c895c990ed8 100644 --- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml +++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml @@ -19,6 +19,12 @@ description: | properties: compatible: const: google,cros-ec-pwm + + google,use-pwm-type: + description: + Use PWM types (CROS_EC_PWM_DT_<...>) instead of generic channels. + type: boolean + "#pwm-cells": description: The cell specifies the PWM index. const: 1
Update google,cros-ec-pwm node documentation to mention the google,use_pwm_type property. Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> --- .../devicetree/bindings/pwm/google,cros-ec-pwm.yaml | 6 ++++++ 1 file changed, 6 insertions(+)