[v2,1/4] dt-bindings: mfd: Add RZ/V2M PWC

The Renesas RZ/V2M External Power Sequence Controller (PWC)
IP is a multi-function device, and it's capable of:
* external power supply on/off sequence generation
* on/off signal generation for the LPDDR4 core power supply (LPVDD)
* key input signals processing
* general-purpose output pins

Add the corresponding dt-bindings.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
---

v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child nodes.

 .../bindings/mfd/renesas,rzv2m-pwc.yaml       | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/renesas,rzv2m-pwc.yaml

On Wed, 21 Dec 2022 21:09:14 +0000, Fabrizio Castro wrote:
> The Renesas RZ/V2M External Power Sequence Controller (PWC)
> IP is a multi-function device, and it's capable of:
> * external power supply on/off sequence generation
> * on/off signal generation for the LPDDR4 core power supply (LPVDD)
> * key input signals processing
> * general-purpose output pins
> 
> Add the corresponding dt-bindings.
> 
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> ---
> 
> v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child nodes.
> 
>  .../bindings/mfd/renesas,rzv2m-pwc.yaml       | 56 +++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/renesas,rzv2m-pwc.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Hi Fabrizio,

On Wed, Dec 21, 2022 at 10:09 PM Fabrizio Castro
<fabrizio.castro.jz@renesas.com> wrote:
> The Renesas RZ/V2M External Power Sequence Controller (PWC)
> IP is a multi-function device, and it's capable of:
> * external power supply on/off sequence generation
> * on/off signal generation for the LPDDR4 core power supply (LPVDD)
> * key input signals processing
> * general-purpose output pins
>
> Add the corresponding dt-bindings.
>
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> ---
>
> v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child nodes.

Thanks for the update!

> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/renesas,rzv2m-pwc.yaml
> @@ -0,0 +1,56 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/renesas,rzv2m-pwc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Renesas RZ/V2M External Power Sequence Controller (PWC)
> +
> +description: |+
> +  The PWC IP found in the RZ/V2M family of chips comes with the below
> +  capabilities
> +    - external power supply on/off sequence generation
> +    - on/off signal generation for the LPDDR4 core power supply (LPVDD)
> +    - key input signals processing
> +    - general-purpose output pins
> +
> +maintainers:
> +  - Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - renesas,r9a09g011-pwc # RZ/V2M
> +          - renesas,r9a09g055-pwc # RZ/V2MA
> +      - const: renesas,rzv2m-pwc
> +
> +  reg:
> +    maxItems: 1
> +
> +  gpio-controller: true
> +
> +  '#gpio-cells':
> +    const: 2
> +
> +  renesas,rzv2m-pwc-power:
> +    description: The PWC is used to control the system power supplies.
> +    type: boolean

I'm wondering if there is some other way to represent this, e.g.
using DT topology? Some regulator relation?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Hi Geert,

Thanks for your feedback!

> From: Geert Uytterhoeven <geert@linux-m68k.org>
> Sent: 03 January 2023 08:29
> Subject: Re: [PATCH v2 1/4] dt-bindings: mfd: Add RZ/V2M PWC
> 
> Hi Fabrizio,
> 
> On Wed, Dec 21, 2022 at 10:09 PM Fabrizio Castro
> <fabrizio.castro.jz@renesas.com> wrote:
> > The Renesas RZ/V2M External Power Sequence Controller (PWC)
> > IP is a multi-function device, and it's capable of:
> > * external power supply on/off sequence generation
> > * on/off signal generation for the LPDDR4 core power supply (LPVDD)
> > * key input signals processing
> > * general-purpose output pins
> >
> > Add the corresponding dt-bindings.
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> > ---
> >
> > v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child
> nodes.
> 
> Thanks for the update!
> 
> > +  renesas,rzv2m-pwc-power:
> > +    description: The PWC is used to control the system power supplies.
> > +    type: boolean
> 
> I'm wondering if there is some other way to represent this, e.g.
> using DT topology? Some regulator relation?

Not that I can think of. With respect to power, this IP only generates
control (enable) signals for external regulators, it does not supply
power.

Thanks,
Fab

> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
> 
> In personal conversations with technical people, I call myself a hacker.
> But
> when I'm talking to journalists I just say "programmer" or something like
> that.
>                                 -- Linus Torvalds