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References: <20230125083248.1305270-1-victor.liu@nxp.com>
In-Reply-To: <20230125083248.1305270-1-victor.liu@nxp.com>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 25 Jan 2023 10:05:10 +0100
Message-ID: <CAMuHMdU0KaRyP0qxJLwit1G=7zMr1k5wpCkG-wD31958mrKRWg@mail.gmail.com>
Subject: Re: [PATCH] driver: bus: simple-pm-bus: Add Freescale i.MX8qm/qxp CSR
 compatible strings
To:     Liu Ying <victor.liu@nxp.com>
Cc:     linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
        linux-imx@nxp.com, Rob Herring <robh@kernel.org>,
        Lee Jones <lee@kernel.org>
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Hi Liu,

On Wed, Jan 25, 2023 at 9:31 AM Liu Ying <victor.liu@nxp.com> wrote:
> Freescale i.MX8qm/qxp CSR module matches with what the simple power
> managed bus driver does, considering it needs an IPG clock to be
> enabled before accessing it's child devices, the child devices need
> to be populated by the CSR module and the child devices' power
> management operations need to be propagated to their parent devices.
> Add the CSR module's compatible strings to simple_pm_bus_of_match[]
> table to support the CSR module.
>
> Suggested-by: Rob Herring <robh@kernel.org>
> Suggested-by: Lee Jones <lee@kernel.org>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>

Thanks for your patch!

> ---
> The CSR module's dt-binding documentation can be found at
> Documentation/devicetree/bindings/mfd/fsl,imx8qxp-csr.yaml.
>
> Suggested by Rob and Lee in this thread:
> https://patchwork.kernel.org/project/linux-arm-kernel/patch/20221017075702.4182846-1-victor.liu@nxp.com/
>
>  drivers/bus/simple-pm-bus.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/bus/simple-pm-bus.c b/drivers/bus/simple-pm-bus.c
> index 7afe1947e1c0..4a7575afe6c6 100644
> --- a/drivers/bus/simple-pm-bus.c
> +++ b/drivers/bus/simple-pm-bus.c
> @@ -120,6 +120,8 @@ static const struct of_device_id simple_pm_bus_of_match[] = {
>         { .compatible = "simple-mfd",   .data = ONLY_BUS },
>         { .compatible = "isa",          .data = ONLY_BUS },
>         { .compatible = "arm,amba-bus", .data = ONLY_BUS },
> +       { .compatible = "fsl,imx8qm-lvds-csr", },
> +       { .compatible = "fsl,imx8qxp-mipi-lvds-csr", },

I did read the thread linked above, and I still think you should just
add "simple-pm-bus" to the compatible value in DTS, so no driver change
is needed, cfr. Documentation/devicetree/bindings/bus/renesas,bsc.yaml.

If that doesn't work due to DT binding constraints, the latter should
be fixed.

>         { /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);

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