Re: [PATCH 3/3] pinctrl: sh-pfc: r8a7794: Implement voltage switching for SDHI

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Simon,

On Thu, Sep 8, 2016 at 1:36 PM, Simon Horman <horms+renesas@xxxxxxxxxxxx> wrote:
> All the SHDIs can operate with either 3.3V or 1.8V signals, depending
> on negotiation with the card.
>
> Based on work by Wolfram Sang for the r8a7790.
>
> Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>

Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

> ---
>  drivers/pinctrl/sh-pfc/pfc-r8a7794.c | 34 +++++++++++++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
> index 8bc2cf0c594e..c02b367837b7 100644
> --- a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
> +++ b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
> @@ -5160,8 +5162,38 @@ static const struct pinmux_cfg_reg pinmux_config_regs[] = {
>         { },
>  };
>
> +static int r8a7794_pin_to_pocctrl(struct sh_pfc *pfc, unsigned int pin, u32 *pocctrl)
> +{
> +       if (pin < RCAR_GP_PIN(6, 0) || pin > RCAR_GP_PIN(6, 23))
> +               return -EINVAL;
> +
> +       *pocctrl = 0xe606006c;
> +
> +       /* GP6_16-23 -> bits 31-24 of pocctrl
> +        * GP6_06    -> bit  23    of pocctrl
> +        * GP6_00-05 -> bits 22-17 of pocctrl
> +        * GP6_07    -> bit  16    of pocctrl
> +        * GP6_14    -> bit  15    of pocctrl
> +        * GP6_08-13 -> bits 14-09 of pocctrl
> +        * GP6_15    -> bit  08    of pocctrl
> +        */
> +       if (pin == RCAR_GP_PIN(6, 6) || pin == RCAR_GP_PIN(6, 14))
> +               return 31 - 2 - (pin & 0x1f);
> +       else if (pin == RCAR_GP_PIN(6, 7) || pin == RCAR_GP_PIN(6, 15))
> +               return 31 - 8 - (pin & 0x1f);
> +       else if (pin < RCAR_GP_PIN(6, 14))
> +               return 31 - 9 - (pin & 0x1f);
> +       else
> +               return 31 + 16 - (pin & 0x1f);

While your code is correct, I think it's easier for the casual reader to use
a plain switch () statement, and let the optimizer handle the rest.

> +}

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
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