Subject: Re: [PATCH 1/4] dt-bindings: phy: Add binding for TI TCAN104x CAN transceivers

From: Rob Herring <[email-masked]>
Date: Mon, 12 Apr 2021 12:49:56 -0500

On Mon, Apr 12, 2021 at 12:19:30PM +0200, Marc Kleine-Budde wrote:
> On 4/9/21 3:40 PM, Aswath Govindraju wrote:
> > Add binding documentation for TI TCAN104x CAN transceivers.
> > 
> > Signed-off-by: Aswath Govindraju <[email-masked]>
> > ---
> >  .../bindings/phy/ti,tcan104x-can.yaml         | 56 +++++++++++++++++++
> >  1 file changed, 56 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
> > new file mode 100644
> > index 000000000000..4abfc30a97d0
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
> > @@ -0,0 +1,56 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: "http://devicetree.org/schemas/phy/ti,tcan104x-can.yaml#"
> > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> > +
> > +title: TCAN104x CAN TRANSCEIVER PHY
> > +
> > +maintainers:
> > +  - Aswath Govindraju <[email-masked]>
> > +
> > +properties:
> > +  $nodename:
> > +    pattern: "^tcan104x-phy"
> > +
> > +  compatible:
> > +    enum:
> > +      - ti,tcan1042
> > +      - ti,tcan1043
> 
> Can you create a generic standby only and a generic standby and enable transceiver?

As a fallback compatible fine, but no generic binding please. A generic 
binding can't describe any timing requirements between the 2 GPIO as 
well as supplies when someone wants to add those (and they will).

> 
> > +
> > +  '#phy-cells':
> > +    const: 0
> > +
> > +  standby-gpios:
> > +    description:
> > +      gpio node to toggle standby signal on transceiver
> > +    maxItems: 1
> > +
> > +  enable-gpios:
> > +    description:
> > +      gpio node to toggle enable signal on transceiver
> > +    maxItems: 1
> > +
> > +  max-bitrate:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description:
> > +      max bit rate supported in bps

We already have 'max-speed' for serial devices, use that.

> > +    minimum: 1
> > +
> > +required:
> > +  - compatible
> > +  - '#phy-cells'
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/gpio/gpio.h>
> > +
> > +    transceiver1: tcan104x-phy {
> > +      compatible = "ti,tcan1043";
> > +      #phy-cells = <0>;
> > +      max-bitrate = <5000000>;
> > +      standby-gpios = <&wakeup_gpio1 16 GPIO_ACTIVE_LOW>;
> > +      enable-gpios = <&main_gpio1 67 GPIO_ACTIVE_LOW>;
> > +    };
> > 
> 
> 
> -- 
> Pengutronix e.K.                 | Marc Kleine-Budde           |
> Embedded Linux                   | https://www.pengutronix.de  |
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>