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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>
hifive-unleashed-5.1
Jerome Brunet 2018-05-15 18:36:51 +02:00
parent 72e1f23020
commit bae1106c37
2 changed files with 22 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/clk/meson/clk-mpll.c
View File

@ -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);

3
drivers/clk/meson/clkc.h
View File

@ -86,8 +86,11 @@ 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;