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authorJerome Brunet <jbrunet@baylibre.com>2018-05-15 19:36:51 +0300
committerJerome Brunet <jbrunet@baylibre.com>2018-05-21 12:31:29 +0300
commitbae1106c37c60661a94739b3f0a52138e227d604 (patch)
treeb17f5ce2fedb709c1510376d3c2a4da780d51cc7 /drivers/clk/meson/clk-mpll.c
parent72e1f2302040398dafb64bbb93abdde78c1f2267 (diff)
downloadlinux-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.c24
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);