Re: [PATCH v2 03/13] pinctrl: renesas: pinctrl-rzg2l: Allow more bits for pin configuration

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Prabhakar,

On Tue, Apr 23, 2024 at 7:59 PM Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> The pin configuration bits have been growing for every new SoCs being
> added for the pinctrl-rzg2l driver which would mean updating the macros
> every time for each new configuration. To avoid this allocate additional
> bits for pin configuration by relocating the known fixed bits to the very
> end of the configuration.
>
> Also update the size of 'cfg' to 'u64' to allow more configuration bits in
> the 'struct rzg2l_variable_pin_cfg'.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> RFC->v2
> - Merged the macros and rzg2l_variable_pin_cfg changes into single patch
> - Updated types for the config changes

Thanks for the update!

> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> @@ -78,9 +78,9 @@
>                                          PIN_CFG_FILNUM | \
>                                          PIN_CFG_FILCLKSEL)
>
> -#define PIN_CFG_PIN_MAP_MASK           GENMASK_ULL(35, 28)
> -#define PIN_CFG_PIN_REG_MASK           GENMASK(27, 20)
> -#define PIN_CFG_MASK                   GENMASK(19, 0)
> +#define PIN_CFG_PIN_MAP_MASK           GENMASK_ULL(62, 55)
> +#define PIN_CFG_PIN_REG_MASK           GENMASK_ULL(54, 47)
> +#define PIN_CFG_MASK                   GENMASK_ULL(46, 0)
>
>  /*
>   * m indicates the bitmap of supported pins, a is the register index

> @@ -241,9 +241,9 @@ struct rzg2l_dedicated_configs {
>   * @pin: port pin
>   */
>  struct rzg2l_variable_pin_cfg {
> -       u32 cfg:20;
> -       u32 port:5;
> -       u32 pin:3;
> +       u64 cfg:46;

47, to match PIN_CFG_MASK()?

> +       u64 port:5;
> +       u64 pin:3;
>  };

To avoid such mistakes, and to increase uniformity, I think it would
be good to get rid of this structure, and replace it by masks, to be
used with FIELD_GET() and FIELD_PREP_CONST().

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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