Subject: Re: [PATCH] p54spi: convert to devicetree

From: Christian Lamparter <[email-masked]>
Date: Tue, 14 Mar 2023 21:18:55 +0100

Hi,

On 3/14/23 17:30, Arnd Bergmann wrote:
> The Prism54 SPI driver hardcodes GPIO numbers and expects users to
> pass them as module parameters, apparently a relic from its life as a
> staging driver. This works because there is only one user, the Nokia
> N8x0 tablet.
> 
> Convert this to the gpio descriptor interface and move the gpio
> line information into devicetree to improve this and simplify the
> code at the same time.

Yes, this is definitely the right idea/way. From what I remember, Kalle
Valo was partially involved in p54spi/stlc45xx. The details are very fuzzy.
So,  I could be totally wrong. From what I remember Kalle was working
for Nokia (or as a contractor for Nokia?) at the time.

> Signed-off-by: Arnd Bergmann <[email-masked]>

I've seen the device-tree comments. That said, this is/was overdue.
You can definitely have this for a v2 :).
Acked-by: Christian Lamparter <[email-masked]>

Thanks you!
Christian

> ---
> As I don't have an N8x0, this is completely untested.
> 
> I listed the driver authors (Johannes and Christian) as the maintainers
> of the binding document, but I don't know if they actually have this
> hardware. It might be better to list someone who is actually using it.
> 
> Among the various chip identifications, I wasn't sure which one to
> use for the compatible string and the name of the binding document.
> I picked st,stlc4560 as that was cited as the version in the N800
> on multiple websites.
> ---
>   .../bindings/net/wireless/st,stlc45xx.yaml    | 64 +++++++++++++++++
>   MAINTAINERS                                   |  1 +
>   arch/arm/boot/dts/omap2.dtsi                  |  4 ++
>   arch/arm/boot/dts/omap2420-n8x0-common.dtsi   | 12 ++++
>   arch/arm/mach-omap2/board-n8x0.c              | 18 -----
>   drivers/net/wireless/intersil/p54/p54spi.c    | 69 +++++++------------
>   drivers/net/wireless/intersil/p54/p54spi.h    |  3 +
>   7 files changed, 109 insertions(+), 62 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/net/wireless/st,stlc45xx.yaml
> 
> diff --git a/Documentation/devicetree/bindings/net/wireless/st,stlc45xx.yaml b/Documentation/devicetree/bindings/net/wireless/st,stlc45xx.yaml
> new file mode 100644
> index 000000000000..45bc4fab409a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/wireless/st,stlc45xx.yaml
> @@ -0,0 +1,64 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/net/wireless/st,stlc45xx.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ST/Intersil/Conexant stlc45xx/p54spi/cx3110x SPI wireless device
> +
> +maintainers:
> +  - Johannes Berg <[email-masked]>
> +  - Christian Lamparter <[email-masked]>
Can you please change that to: Christian Lamparter <[email-masked]> ?
(the @web.de/googlemail.com address still work too, but they are now just
forwarding)

> +description: |
> +  The SPI variant of the Intersil Prism54 wireless device was sold
> +  under a variety of names, including ST Microelectronics STLC5460
> +  and Conexant CX3110x.
> +
> +allOf:
> +  - $ref: ieee80211.yaml#
> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - st,stlc4550
> +      - st,stlc4560
> +      - isil,p54spi
> +      - cnxt,3110x
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  power-gpios:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +   gpio {
> +     gpio-controller;
> +     #gpio-cells = <1>;
> +     #interupt-cells = <1>;
> +   };
> +   spi {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      wifi@0 {
> +        reg = <0>;
> +        compatible = "st,stlc4560";
> +        spi-max-frequency = <48000000>;
> +        interrupts-extended = <&gpio 23>;
> +        power-gpios = <&gpio 1>;
> +     };
> +   };