Re: [RFC 3/5] arm: dts: dt-bindings: Add Renesas RZ pinctrl header

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Jacopo,

On Wed, Jan 25, 2017 at 7:09 PM, Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> wrote:
> Add dt-bindings header for Renesas RZ pincontroller.
> The header defines macros for pin description and alternate function
> numbers.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> ---
>  include/dt-bindings/pinctrl/pinctrl-renesas-rz.h | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>  create mode 100644 include/dt-bindings/pinctrl/pinctrl-renesas-rz.h
>
> diff --git a/include/dt-bindings/pinctrl/pinctrl-renesas-rz.h b/include/dt-bindings/pinctrl/pinctrl-renesas-rz.h
> new file mode 100644
> index 0000000..92816d4
> --- /dev/null
> +++ b/include/dt-bindings/pinctrl/pinctrl-renesas-rz.h
> @@ -0,0 +1,19 @@
> +/*
> + * Defines macros and constants for Renesas RZ pin controller and muxer
> + */
> +
> +#ifndef __DT_BINDINGS_PINCTRL_RENESAS_RZ_H
> +#define __DT_BINDINGS_PINCTRL_RENESAS_RZ_H
> +
> +#define RZ_PIN(b, p) b p

And the advantage of this macro is?

> +#define ALTERNATE_FUNC_1       0
> +#define ALTERNATE_FUNC_2       1
> +#define ALTERNATE_FUNC_3       2
> +#define ALTERNATE_FUNC_4       3
> +#define ALTERNATE_FUNC_5       4
> +#define ALTERNATE_FUNC_6       5
> +#define ALTERNATE_FUNC_7       6
> +#define ALTERNATE_FUNC_8       7

I have mixed feelings about these macros:
  1. They're long to type,
  2. They just map from n to n-1.

Why not use plain numbers 1..8 (the alternate function numbering in the
datasheet is 1-based), and subtract 1 in the C code?

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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