Re: [PATCH][repost] sh: clkfwk: remove r8/r16/r32

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Morimoto-san,

On Thu, Jan 9, 2020 at 1:29 AM Kuninori Morimoto
<kuninori.morimoto.gx@renesas.com> wrote:
> From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
>
> SH will get below warning
>
> ${LINUX}/drivers/sh/clk/cpg.c: In function 'r8':
> ${LINUX}/drivers/sh/clk/cpg.c:41:17: warning: passing argument 1 of 'ioread8'
>  discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>   return ioread8(addr);
>                  ^~~~
> In file included from ${LINUX}/arch/sh/include/asm/io.h:21,
>                  from ${LINUX}/include/linux/io.h:13,
>                  from ${LINUX}/drivers/sh/clk/cpg.c:14:
> ${LINUX}/include/asm-generic/iomap.h:29:29: note: expected 'void *' but
> argument is of type 'const void *'
>  extern unsigned int ioread8(void __iomem *);
>                              ^~~~~~~~~~~~~~
>
> We don't need "const" for r8/r16/r32.
> And we don't need r8/r16/r32 themselvs.
> This patch cleanup these.
>
> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

One note below.

> --- a/drivers/sh/clk/cpg.c
> +++ b/drivers/sh/clk/cpg.c
> @@ -36,36 +36,21 @@ static void sh_clk_write(int value, struct clk *clk)
>                 iowrite32(value, clk->mapped_reg);
>  }
>
> -static unsigned int r8(const void __iomem *addr)
> -{
> -       return ioread8(addr);
> -}
> -
> -static unsigned int r16(const void __iomem *addr)
> -{
> -       return ioread16(addr);
> -}
> -
> -static unsigned int r32(const void __iomem *addr)
> -{
> -       return ioread32(addr);
> -}
> -
>  static int sh_clk_mstp_enable(struct clk *clk)
>  {
>         sh_clk_write(sh_clk_read(clk) & ~(1 << clk->enable_bit), clk);
>         if (clk->status_reg) {
> -               unsigned int (*read)(const void __iomem *addr);
> +               unsigned int (*read)(void __iomem *addr);

While it is good to get rid of the wrappers, the change above will conflict with
[PATCH v2 1/9] iomap: Constify ioreadX() iomem argument (as in generic
implementation)
(https://lore.kernel.org/lkml/20200108200528.4614-2-krzk@kernel.org/),
which will add const to ioread*().

>                 int i;
>                 void __iomem *mapped_status = (phys_addr_t)clk->status_reg -
>                         (phys_addr_t)clk->enable_reg + clk->mapped_reg;
>
>                 if (clk->flags & CLK_ENABLE_REG_8BIT)
> -                       read = r8;
> +                       read = ioread8;
>                 else if (clk->flags & CLK_ENABLE_REG_16BIT)
> -                       read = r16;
> +                       read = ioread16;
>                 else
> -                       read = r32;
> +                       read = ioread32;
>
>                 for (i = 1000;
>                      (read(mapped_status) & (1 << clk->enable_bit)) && i;

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