[RFC V1 3/8] clk: Add support for simple dividers

[Mike Turquette]

On Wed, Nov 23, 2011 at 3:12 AM, Richard Zhao <richard.zhao at linaro.org> wrote:
> +#define account_for_rounding_errors    1
> +
> +static int clk_divider_bestdiv(struct clk *clk, unsigned long rate,
> +               unsigned long *best_parent_rate)
> +{
> +       struct clk_divider *divider = to_clk_divider(clk);
> +       int i, bestdiv = 0;
> +       unsigned long parent_rate, best = 0, now, maxdiv;
> +
> +       maxdiv = (1 << divider->width);
> +
> +       if (divider->flags & CLK_DIVIDER_FLAG_ONE_BASED)
> +               maxdiv--;
> +
> +       if (!(clk->flags & CLK_PARENT_SET_RATE)) {
> +               parent_rate = clk->parent->rate;
> +               bestdiv = parent_rate / rate;
> +               bestdiv = bestdiv == 0 ? 1 : bestdiv;
> +               bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
> +               goto out;
> +       }
> +
> +       /*
> +        * The maximum divider we can use without overflowing
> +        * unsigned long in rate * i below
> +        */
> +       maxdiv = min(ULONG_MAX / rate, maxdiv);
> +
> +       for (i = 1; i <= maxdiv; i++) {
> +               parent_rate = clk_round_rate(clk->parent,
> +                               (rate + account_for_rounding_errors) * i);

How about just ((rate + 1) * i) with a comment above explaining why?
This removes the awkward #define above.

Also, I'd like to roll this into clk-basic.c for the V4 series.  Any objections?

Thanks,
Mike