diff mbox series

[RFC,05/10] dt-bindings: pwm: Add bindings for PWM function in Netronix EC

Message ID 20200620224222.1312520-4-j.neuschaefer@gmx.net
State RFC
Headers show
Series Netronix embedded controller driver for Kobo and Tolino ebook readers | expand

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Context Check Description
robh/dt-meta-schema fail build log
robh/checkpatch warning total: 0 errors, 1 warnings, 57 lines checked

Commit Message

Jonathan Neuschäfer June 20, 2020, 10:42 p.m. UTC
The Netronix embedded controller as found in Kobo Aura and Tolino Shine
supports one PWM channel, which is used to control the frontlight
brightness on these devices.

Known problems:
- `make dt_binding_check` shows the following warnings:
  Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
  Warning (pwms_property): /example-0/backlight:pwms: cell 2 is not a
  phandle reference
  Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
  Warning (pwms_property): /example-0/backlight:pwms: Could not get
  phandle node for (cell 2)

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
---
 .../bindings/mfd/netronix,ntxec.yaml          | 13 ++++++++
 .../bindings/pwm/netronix,ntxec-pwm.yaml      | 33 +++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml

--
2.27.0

Comments

Andreas Kemnade June 21, 2020, 6:41 p.m. UTC | #1
On Sun, 21 Jun 2020 00:42:16 +0200
Jonathan Neuschäfer <j.neuschaefer@gmx.net> wrote:

> The Netronix embedded controller as found in Kobo Aura and Tolino Shine
> supports one PWM channel, which is used to control the frontlight
> brightness on these devices.
> 
> Known problems:
> - `make dt_binding_check` shows the following warnings:
>   Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
>   Warning (pwms_property): /example-0/backlight:pwms: cell 2 is not a
>   phandle reference
>   Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
>   Warning (pwms_property): /example-0/backlight:pwms: Could not get
>   phandle node for (cell 2)
> 
In the tolino sources in ./drivers/misc/ntx-misc.c I find this line

        if(4==gptHWCFG->m_val.bFL_PWM) {

No idea what it does but I would expect to have a kind of translation to
a dt property?

> Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> ---
>  .../bindings/mfd/netronix,ntxec.yaml          | 13 ++++++++
>  .../bindings/pwm/netronix,ntxec-pwm.yaml      | 33 +++++++++++++++++++
>  2 files changed, 46 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> index 596df460f98eb..6562c41c5a9a9 100644
> --- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> +++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> @@ -31,6 +31,9 @@ properties:
>      description:
>        The EC can signal interrupts via a GPIO line
> 
> +  pwm:
> +    $ref: ../pwm/netronix,ntxec-pwm.yaml
> +
>  required:
>    - compatible
>    - reg
> @@ -53,5 +56,15 @@ examples:
>                      interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
>                      interrupt-controller;
>                      #interrupt-cells = <1>;
> +
> +                    ec_pwm: pwm {
> +                            compatible = "netronix,ntxec-pwm";
> +                            #pwm-cells = <1>;
shouldn't that be 2?
> +                    };
>              };
>      };
> +
> +    backlight {
> +            compatible = "pwm-backlight";
> +            pwms = <&ec_pwm 0 50000>;
since you have 2 values after the &ec_pwm 

> +    };
> diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
> new file mode 100644
> index 0000000000000..1dc1b1aba081c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
> @@ -0,0 +1,33 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/netronix,ntxec-pwm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: PWM functionality in Netronix embedded controller
> +
> +maintainers:
> +  - Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> +
> +description: |
> +  See also Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> +
> +  The Netronix EC contains PWM functionality, which is usually used to drive
> +  the backlight LED.
> +
> +  The following PWM channels are supported:
> +    - 0: The PWM channel controlled by registers 0xa1-0xa7
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +properties:
> +  compatible:
> +    const: netronix,ntxec-pwm
> +
> +  "#pwm-cells":
> +    const: 1

shouln't that be 2?
> +
> +required:
> +  - compatible
> +  - "#pwm-cells"
> --
> 2.27.0
> 
> 

Regards,
Andreas
Jonathan Neuschäfer Aug. 23, 2020, 10:42 p.m. UTC | #2
On Sun, Jun 21, 2020 at 08:41:23PM +0200, Andreas Kemnade wrote:
> On Sun, 21 Jun 2020 00:42:16 +0200
> Jonathan Neuschäfer <j.neuschaefer@gmx.net> wrote:
> 
> > The Netronix embedded controller as found in Kobo Aura and Tolino Shine
> > supports one PWM channel, which is used to control the frontlight
> > brightness on these devices.
> > 
> > Known problems:
> > - `make dt_binding_check` shows the following warnings:
> >   Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
> >   Warning (pwms_property): /example-0/backlight:pwms: cell 2 is not a
> >   phandle reference
> >   Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
> >   Warning (pwms_property): /example-0/backlight:pwms: Could not get
> >   phandle node for (cell 2)
> > 
> In the tolino sources in ./drivers/misc/ntx-misc.c I find this line
> 
>         if(4==gptHWCFG->m_val.bFL_PWM) {
> 
> No idea what it does but I would expect to have a kind of translation to
> a dt property?

As far as I understand it, FL_PWM=4 means that there is a second PWM
channel, in order to provide different backlight colors.

I think it should be possible to simply extend the binding to list
another available PWM channel, once we add support for such hardware.

> > +                    ec_pwm: pwm {
> > +                            compatible = "netronix,ntxec-pwm";
> > +                            #pwm-cells = <1>;
> shouldn't that be 2?
> > +                    };
> >              };
> >      };
> > +
> > +    backlight {
> > +            compatible = "pwm-backlight";
> > +            pwms = <&ec_pwm 0 50000>;
> since you have 2 values after the &ec_pwm 
[...]
> > +properties:
> > +  compatible:
> > +    const: netronix,ntxec-pwm
> > +
> > +  "#pwm-cells":
> > +    const: 1
> 
> shouln't that be 2?

Right, I'll fix that.


Thanks,
Jonathan
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
index 596df460f98eb..6562c41c5a9a9 100644
--- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
+++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
@@ -31,6 +31,9 @@  properties:
     description:
       The EC can signal interrupts via a GPIO line

+  pwm:
+    $ref: ../pwm/netronix,ntxec-pwm.yaml
+
 required:
   - compatible
   - reg
@@ -53,5 +56,15 @@  examples:
                     interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
                     interrupt-controller;
                     #interrupt-cells = <1>;
+
+                    ec_pwm: pwm {
+                            compatible = "netronix,ntxec-pwm";
+                            #pwm-cells = <1>;
+                    };
             };
     };
+
+    backlight {
+            compatible = "pwm-backlight";
+            pwms = <&ec_pwm 0 50000>;
+    };
diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
new file mode 100644
index 0000000000000..1dc1b1aba081c
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
@@ -0,0 +1,33 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/netronix,ntxec-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PWM functionality in Netronix embedded controller
+
+maintainers:
+  - Jonathan Neuschäfer <j.neuschaefer@gmx.net>
+
+description: |
+  See also Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
+
+  The Netronix EC contains PWM functionality, which is usually used to drive
+  the backlight LED.
+
+  The following PWM channels are supported:
+    - 0: The PWM channel controlled by registers 0xa1-0xa7
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    const: netronix,ntxec-pwm
+
+  "#pwm-cells":
+    const: 1
+
+required:
+  - compatible
+  - "#pwm-cells"