diff options
| author | Jerome Brunet <jbrunet@baylibre.com> | 2018-05-15 19:36:51 +0300 |
|---|---|---|
| committer | Jerome Brunet <jbrunet@baylibre.com> | 2018-05-21 12:31:29 +0300 |
| commit | bae1106c37c60661a94739b3f0a52138e227d604 (patch) | |
| tree | b17f5ce2fedb709c1510376d3c2a4da780d51cc7 /drivers/clk/meson/clk-mpll.c | |
| parent | 72e1f2302040398dafb64bbb93abdde78c1f2267 (diff) | |
| download | linux-bae1106c37c60661a94739b3f0a52138e227d604.tar.xz | |
clk: meson: mpll: add round closest support
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.
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Martin Blumenstingl<martin.blumenstingl@googlemail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Diffstat (limited to 'drivers/clk/meson/clk-mpll.c')
| -rw-r--r-- | drivers/clk/meson/clk-mpll.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c index 45c3a2261f2f..650f75cc15a9 100644 --- a/drivers/clk/meson/clk-mpll.c +++ b/drivers/clk/meson/clk-mpll.c @@ -39,10 +39,23 @@ 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); + + frac *= SDM_DEN; + + if (flags & CLK_MESON_MPLL_ROUND_CLOSEST) + *sdm = DIV_ROUND_CLOSEST_ULL(frac, requested_rate); + else + *sdm = DIV_ROUND_UP_ULL(frac, requested_rate); + + if (*sdm == SDM_DEN) { + *sdm = 0; + div += 1; + } if (div < N2_MIN) { *n2 = N2_MIN; @@ -52,7 +65,6 @@ 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); } } @@ -75,9 +87,11 @@ 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); } @@ -90,7 +104,7 @@ 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); |