diff options
| author | Jerome Brunet <jbrunet@baylibre.com> | 2018-02-19 14:21:41 +0300 |
|---|---|---|
| committer | Neil Armstrong <narmstrong@baylibre.com> | 2018-03-13 12:09:49 +0300 |
| commit | 0a1be867b92a5afb93bce62e12ef76b7c2b777fd (patch) | |
| tree | eec860f0aa566ddee431d99b07149c2c65d64ef5 /drivers/clk/meson/clk-pll.c | |
| parent | c77de0e5c95a249fd2d4105dbc619f436ec96345 (diff) | |
| download | linux-0a1be867b92a5afb93bce62e12ef76b7c2b777fd.tar.xz | |
clk: meson: add ROUND_CLOSEST to the pll driver
Provide an option for the pll driver to round to the rate closest to the
requested rate, instead of systematically rounding down.
This may allow the provided rate to be closer to the requested rate when
rounding up is not an issue
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Diffstat (limited to 'drivers/clk/meson/clk-pll.c')
| -rw-r--r-- | drivers/clk/meson/clk-pll.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c index d58961f35b71..65a7bd903551 100644 --- a/drivers/clk/meson/clk-pll.c +++ b/drivers/clk/meson/clk-pll.c @@ -105,7 +105,12 @@ static u16 __pll_params_with_frac(unsigned long rate, u64 val = (u64)rate * pllt->n; val <<= pllt->od + pllt->od2 + pllt->od3; - val = div_u64(val * frac_max, parent_rate); + + if (pll->flags & CLK_MESON_PLL_ROUND_CLOSEST) + val = DIV_ROUND_CLOSEST_ULL(val * frac_max, parent_rate); + else + val = div_u64(val * frac_max, parent_rate); + val -= pllt->m * frac_max; return min((u16)val, (u16)(frac_max - 1)); @@ -125,9 +130,13 @@ meson_clk_get_pll_settings(unsigned long rate, while (table[i].rate && table[i].rate <= rate) i++; - /* Select the setting of the rounded down rate */ - if (i != 0) - i--; + if (i != 0) { + if (MESON_PARM_APPLICABLE(&pll->frac) || + !(pll->flags & CLK_MESON_PLL_ROUND_CLOSEST) || + (abs(rate - table[i - 1].rate) < + abs(rate - table[i].rate))) + i--; + } return (struct pll_rate_table *)&table[i]; } |