[RFC,07/10] dt-bindings: rtc: Add bindings for Netronix embedded controller RTC

The Netronix EC implements an RTC with the following functionality:

- Calendar-based time keeping with single-second resolution
- Automatic power-on with single-minute resolution
- Alarm at single-second resolution

This binding only supports timekeeping for now.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
---
 .../bindings/mfd/netronix,ntxec.yaml          |  7 +++++
 .../bindings/rtc/netronix,ntxec-rtc.yaml      | 27 +++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml

--
2.27.0

Hi,

On 21/06/2020 00:42:18+0200, Jonathan Neuschäfer wrote:
> The Netronix EC implements an RTC with the following functionality:
> 
> - Calendar-based time keeping with single-second resolution
> - Automatic power-on with single-minute resolution
> - Alarm at single-second resolution
> 
> This binding only supports timekeeping for now.
> 
> Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> ---
>  .../bindings/mfd/netronix,ntxec.yaml          |  7 +++++
>  .../bindings/rtc/netronix,ntxec-rtc.yaml      | 27 +++++++++++++++++++
>  2 files changed, 34 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> index 6562c41c5a9a9..f6a32f46f47bb 100644
> --- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> +++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> @@ -34,6 +34,9 @@ properties:
>    pwm:
>      $ref: ../pwm/netronix,ntxec-pwm.yaml
> 
> +  rtc:
> +    $ref: ../rtc/netronix,ntxec-rtc.yaml
> +

Shouldn't the node simply be documented here?

Also, do you really need a compatible string to be able to proe the
driver? What are the chances that you'll get a similar EC without an
RTC?

>  required:
>    - compatible
>    - reg
> @@ -61,6 +64,10 @@ examples:
>                              compatible = "netronix,ntxec-pwm";
>                              #pwm-cells = <1>;
>                      };
> +
> +                    rtc {
> +                            compatible = "netronix,ntxec-rtc";
> +                    };
>              };
>      };
> 
> diff --git a/Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml b/Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml
> new file mode 100644
> index 0000000000000..4b301ef7319c8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml
> @@ -0,0 +1,27 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/netronix,ntxec-rtc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: RTC 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 an RTC, which can be used for time-keeping, alarm,
> +  and automatic power-on. Note that not all of this functionality is currently
> +  supported in this binding.
> +
> +allOf:
> +  - $ref: "rtc.yaml#"
> +
> +properties:
> +  compatible:
> +    const: netronix,ntxec-rtc
> +
> +required:
> +  - compatible
> --
> 2.27.0
>

On Sun, 21 Jun 2020 02:02:20 +0200
Alexandre Belloni <alexandre.belloni@bootlin.com> wrote:

> Hi,
> 
> On 21/06/2020 00:42:18+0200, Jonathan Neuschäfer wrote:
> > The Netronix EC implements an RTC with the following functionality:
> > 
> > - Calendar-based time keeping with single-second resolution
> > - Automatic power-on with single-minute resolution
> > - Alarm at single-second resolution
> > 
> > This binding only supports timekeeping for now.
> > 
> > Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> > ---
> >  .../bindings/mfd/netronix,ntxec.yaml          |  7 +++++
> >  .../bindings/rtc/netronix,ntxec-rtc.yaml      | 27 +++++++++++++++++++
> >  2 files changed, 34 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > index 6562c41c5a9a9..f6a32f46f47bb 100644
> > --- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > +++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > @@ -34,6 +34,9 @@ properties:
> >    pwm:
> >      $ref: ../pwm/netronix,ntxec-pwm.yaml
> > 
> > +  rtc:
> > +    $ref: ../rtc/netronix,ntxec-rtc.yaml
> > +  
> 
> Shouldn't the node simply be documented here?
> 
> Also, do you really need a compatible string to be able to proe the
> driver? What are the chances that you'll get a similar EC without an
> RTC?
> 
Tolino Shine 2 HD has the mentioned EC but the vendor kernel does not use
its RTC (not checked whether it is present or functional).
As a key for grepping in the vendor sources: 
gptNtxHwCfg->m_val.bPCB = 0x50

Tolino Shine 3  and Kobo Clara HD do not have that EC.

Regrads,
Andreas

On Fri, Jun 26, 2020 at 11:55:52PM +0200, Andreas Kemnade wrote:
> On Sun, 21 Jun 2020 02:02:20 +0200
> Alexandre Belloni <alexandre.belloni@bootlin.com> wrote:
[...]
> > Also, do you really need a compatible string to be able to proe the
> > driver? What are the chances that you'll get a similar EC without an
> > RTC?
> > 
> Tolino Shine 2 HD has the mentioned EC but the vendor kernel does not use
> its RTC (not checked whether it is present or functional).
> As a key for grepping in the vendor sources: 
> gptNtxHwCfg->m_val.bPCB = 0x50

Thanks for checking.

(In the MMC dump from my Shine 2 HD, it's decimal 50 rather than hex)

> Tolino Shine 3  and Kobo Clara HD do not have that EC.

Fortunately, this set of drivers isn't needed at all in that case.


Thanks,
Jonathan