| Message ID | 20180420095603.29964-2-jbrunet@baylibre.com |
|---|---|
| State | New |
| Headers | show |
| Series | clk: meson: mpll: add round closest support | expand |
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 <jbrunet@baylibre.com> > --- > 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 <narmstrong@baylibre.com>
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;
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 <jbrunet@baylibre.com> --- drivers/clk/meson/clk-mpll.c | 25 ++++++++++++++++++++----- drivers/clk/meson/clkc.h | 3 +++ 2 files changed, 23 insertions(+), 5 deletions(-) -- 2.14.3