Re: [PATCH v3 06/46] media: sun6i-csi: Define and use variant to get module clock rate

From: Paul Kocialkowski
Date: Fri Mar 18 2022 - 04:54:40 EST


Hi Jernej,

On Tue 15 Mar 22, 20:31, Jernej Škrabec wrote:
> Dne petek, 11. marec 2022 ob 15:34:52 CET je Paul Kocialkowski napisal(a):
> > Introduce a proper variant structure with the module clock rate
> > instead of hardcoding it with a manual check on the compatible.
> >
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
> > ---
> > .../platform/sunxi/sun6i-csi/sun6i_csi.c | 48 ++++++++++++++-----
> > .../platform/sunxi/sun6i-csi/sun6i_csi.h | 4 ++
> > 2 files changed, 40 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/
> media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > index 2355088fdc37..4a0d08e0ac25 100644
> > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > @@ -811,11 +811,17 @@ static int sun6i_csi_resources_setup(struct
> sun6i_csi_device *csi_dev,
> > struct platform_device
> *platform_dev)
> > {
> > struct device *dev = csi_dev->dev;
> > - unsigned long clk_mod_rate;
> > + const struct sun6i_csi_variant *variant;
>
> Ideally, this should be sorted from longest to shortest.

I typically try to have definitions with affectations first and then
just definitions, sorted longest to shortest unless there is some dependency
between definitions.

> > void __iomem *io_base;
> > int ret;
> > int irq;
> >
> > + /* Variant */
>
> I don't think this comment is very useful (nor one below for that matter.)
> Please remove it.

It's not really a comment per-se, but rather a section header.
I have similar ones for Clocks / Reset / Interrupt / Runtime PM so
that's why it felt consistent to add one for Variant too.

The point is to keep related topics grouped together and I'd rather keep it.

Cheers,

Paul

> With that:
> Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
>
> Best regards,
> Jernej
>
> > +
> > + variant = of_device_get_match_data(dev);
> > + if (!variant)
> > + return -EINVAL;
> > +
> > /* Registers */
> >
> > io_base = devm_platform_ioremap_resource(platform_dev, 0);
> > @@ -849,12 +855,7 @@ static int sun6i_csi_resources_setup(struct
> sun6i_csi_device *csi_dev,
> > return PTR_ERR(csi_dev->clk_ram);
> > }
> >
> > - if (of_device_is_compatible(dev->of_node, "allwinner,sun50i-a64-
> csi"))
> > - clk_mod_rate = 300000000;
> > - else
> > - clk_mod_rate = 297000000;
> > -
> > - ret = clk_set_rate_exclusive(csi_dev->clk_mod, clk_mod_rate);
> > + ret = clk_set_rate_exclusive(csi_dev->clk_mod, variant-
> >clk_mod_rate);
> > if (ret) {
> > dev_err(dev, "failed to set mod clock rate\n");
> > return ret;
> > @@ -937,12 +938,35 @@ static int sun6i_csi_remove(struct platform_device
> *pdev)
> > return 0;
> > }
> >
> > +static const struct sun6i_csi_variant sun6i_a31_csi_variant = {
> > + .clk_mod_rate = 297000000,
> > +};
> > +
> > +static const struct sun6i_csi_variant sun50i_a64_csi_variant = {
> > + .clk_mod_rate = 300000000,
> > +};
> > +
> > static const struct of_device_id sun6i_csi_of_match[] = {
> > - { .compatible = "allwinner,sun6i-a31-csi", },
> > - { .compatible = "allwinner,sun8i-a83t-csi", },
> > - { .compatible = "allwinner,sun8i-h3-csi", },
> > - { .compatible = "allwinner,sun8i-v3s-csi", },
> > - { .compatible = "allwinner,sun50i-a64-csi", },
> > + {
> > + .compatible = "allwinner,sun6i-a31-csi",
> > + .data = &sun6i_a31_csi_variant,
> > + },
> > + {
> > + .compatible = "allwinner,sun8i-a83t-csi",
> > + .data = &sun6i_a31_csi_variant,
> > + },
> > + {
> > + .compatible = "allwinner,sun8i-h3-csi",
> > + .data = &sun6i_a31_csi_variant,
> > + },
> > + {
> > + .compatible = "allwinner,sun8i-v3s-csi",
> > + .data = &sun6i_a31_csi_variant,
> > + },
> > + {
> > + .compatible = "allwinner,sun50i-a64-csi",
> > + .data = &sun50i_a64_csi_variant,
> > + },
> > {},
> > };
> >
> > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/
> media/platform/sunxi/sun6i-csi/sun6i_csi.h
> > index 356661b413f8..3c4a3af6b897 100644
> > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
> > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
> > @@ -59,6 +59,10 @@ struct sun6i_csi_device {
> > int planar_offset[3];
> > };
> >
> > +struct sun6i_csi_variant {
> > + unsigned long clk_mod_rate;
> > +};
> > +
> > /**
> > * sun6i_csi_is_format_supported() - check if the format supported by csi
> > * @csi: pointer to the csi
> > --
> > 2.35.1
> >
> >
>
>

--
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

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