On 20/04/2018 11:56, Jerome Brunet wrote:
> Allow the mpll driver to round the requested rate up if
> CLK_MESON_MPLL_ROUND_CLOSEST is set and it provides a rate closer to the
> requested rate.
> 
> Signed-off-by: Jerome Brunet <[email protected]>
> ---
>  drivers/clk/meson/clk-mpll.c | 25 ++++++++++++++++++++-----
>  drivers/clk/meson/clkc.h     |  3 +++
>  2 files changed, 23 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
> index 0df1227b65b3..4e5283eb892a 100644
> --- a/drivers/clk/meson/clk-mpll.c
> +++ b/drivers/clk/meson/clk-mpll.c
> @@ -89,10 +89,23 @@ static long rate_from_params(unsigned long parent_rate,
>  static void params_from_rate(unsigned long requested_rate,
>                            unsigned long parent_rate,
>                            unsigned int *sdm,
> -                          unsigned int *n2)
> +                          unsigned int *n2,
> +                          u8 flags)
>  {
>       uint64_t div = parent_rate;
> -     unsigned long rem = do_div(div, requested_rate);
> +     uint64_t frac = do_div(div, requested_rate);
> +     unsigned long rem;
> +
> +     frac *= SDM_DEN;
> +     rem = do_div(frac, requested_rate);
> +
> +     /* Should we round up ? */
> +     if (flags & CLK_MESON_MPLL_ROUND_CLOSEST
> +         && rem > (requested_rate / 2)) {
> +             frac = (frac + 1) % SDM_DEN;
> +             if (frac == 0)
> +                     div += 1;
> +     }
>  
>       if (div < N2_MIN) {
>               *n2 = N2_MIN;
> @@ -102,7 +115,7 @@ static void params_from_rate(unsigned long requested_rate,
>               *sdm = SDM_DEN - 1;
>       } else {
>               *n2 = div;
> -             *sdm = DIV_ROUND_UP_ULL((u64)rem * SDM_DEN, requested_rate);
> +             *sdm = frac;
>       }
>  }
>  
> @@ -125,9 +138,11 @@ static long mpll_round_rate(struct clk_hw *hw,
>                           unsigned long rate,
>                           unsigned long *parent_rate)
>  {
> +     struct clk_regmap *clk = to_clk_regmap(hw);
> +     struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
>       unsigned int sdm, n2;
>  
> -     params_from_rate(rate, *parent_rate, &sdm, &n2);
> +     params_from_rate(rate, *parent_rate, &sdm, &n2, mpll->flags);
>       return rate_from_params(*parent_rate, sdm, n2);
>  }
>  
> @@ -140,7 +155,7 @@ static int mpll_set_rate(struct clk_hw *hw,
>       unsigned int sdm, n2;
>       unsigned long flags = 0;
>  
> -     params_from_rate(rate, parent_rate, &sdm, &n2);
> +     params_from_rate(rate, parent_rate, &sdm, &n2, mpll->flags);
>  
>       if (mpll->lock)
>               spin_lock_irqsave(mpll->lock, flags);
> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
> index 8fe73c4edca8..8cc265cd3d2b 100644
> --- a/drivers/clk/meson/clkc.h
> +++ b/drivers/clk/meson/clkc.h
> @@ -97,8 +97,11 @@ struct meson_clk_mpll_data {
>       struct parm ssen;
>       struct parm misc;
>       spinlock_t *lock;
> +     u8 flags;
>  };
>  
> +#define CLK_MESON_MPLL_ROUND_CLOSEST BIT(0)
> +
>  struct meson_clk_audio_div_data {
>       struct parm div;
>       u8 flags;
> 

Acked-by: Neil Armstrong <[email protected]>

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