[PATCH 02/11] clk: scmi: Use new determine_rate clock operation

[Geert Uytterhoeven]

Hi Cristian,

On Fri, 27 Feb 2026 at 16:33, Cristian Marussi <cristian.marussi at arm.com> wrote:
> Use the Clock protocol layer determine_rate logic to calculate the closest
> rate that can be supported by a specific clock.
>
> No functional change.
>
> Cc: Brian Masney <bmasney at redhat.com>
> Cc: Michael Turquette <mturquette at baylibre.com>
> Cc: Stephen Boyd <sboyd at kernel.org>
> Cc: linux-clk at vger.kernel.org
> Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>

> --- a/drivers/clk/clk-scmi.c
> +++ b/drivers/clk/clk-scmi.c
> @@ -57,35 +56,17 @@ static unsigned long scmi_clk_recalc_rate(struct clk_hw *hw,
>  static int scmi_clk_determine_rate(struct clk_hw *hw,
>                                    struct clk_rate_request *req)
>  {
> -       u64 fmin, fmax, ftmp;
> +       int ret;
>         struct scmi_clk *clk = to_scmi_clk(hw);
>
>         /*
> -        * We can't figure out what rate it will be, so just return the
> -        * rate back to the caller. scmi_clk_recalc_rate() will be called
> -        * after the rate is set and we'll know what rate the clock is
> +        * If we could not get a better rate scmi_clk_recalc_rate() will be
> +        * called after the rate is set and we'll know what rate the clock is
>          * running at then.
>          */
> -       if (clk->info->rate_discrete)
> -               return 0;
> -
> -       fmin = clk->info->range.min_rate;
> -       fmax = clk->info->range.max_rate;
> -       if (req->rate <= fmin) {
> -               req->rate = fmin;
> -
> -               return 0;
> -       } else if (req->rate >= fmax) {
> -               req->rate = fmax;
> -
> -               return 0;
> -       }
> -
> -       ftmp = req->rate - fmin;
> -       ftmp += clk->info->range.step_size - 1; /* to round up */
> -       do_div(ftmp, clk->info->range.step_size);

Oh, so the truncation bug exists in the original code, too.

> -
> -       req->rate = ftmp * clk->info->range.step_size + fmin;
> +       ret = scmi_proto_clk_ops->determine_rate(clk->ph, clk->id, &req->rate);
> +       if (ret)
> +               return ret;
>
>         return 0;

Gr{oetje,eeting}s,

                        Geert

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