diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2021-08-12 20:00:24 +0300 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2021-08-12 12:42:00 -0700 |
| commit | 82f53f9ee5770177eb102446cc3513bf07e2668a (patch) | |
| tree | 40ff03911a7d5b565cf0f889c5c8a8ad6cfb7892 /drivers/clk/clk-fractional-divider.c | |
| parent | 928f9e2686110825262685b7aedc7b21b805fecd (diff) | |
| download | linux-82f53f9ee5770177eb102446cc3513bf07e2668a.tar.bz2 | |
clk: fractional-divider: Introduce POWER_OF_TWO_PS flag
The newly introduced POWER_OF_TWO_PS flag, when set, makes the flow
to skip the assumption that the caller will use an additional 2^scale
prescaler to get the desired clock rate.
Reported-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210812170025.67074-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/clk-fractional-divider.c')
| -rw-r--r-- | drivers/clk/clk-fractional-divider.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c index 535d299af646..6a3ed82fdae9 100644 --- a/drivers/clk/clk-fractional-divider.c +++ b/drivers/clk/clk-fractional-divider.c @@ -76,16 +76,18 @@ void clk_fractional_divider_general_approximation(struct clk_hw *hw, unsigned long *m, unsigned long *n) { struct clk_fractional_divider *fd = to_clk_fd(hw); - unsigned long scale; /* * Get rate closer to *parent_rate to guarantee there is no overflow * for m and n. In the result it will be the nearest rate left shifted * by (scale - fd->nwidth) bits. */ - scale = fls_long(*parent_rate / rate - 1); - if (scale > fd->nwidth) - rate <<= scale - fd->nwidth; + if (fd->flags & CLK_FRAC_DIVIDER_POWER_OF_TWO_PS) { + unsigned long scale = fls_long(*parent_rate / rate - 1); + + if (scale > fd->nwidth) + rate <<= scale - fd->nwidth; + } rational_best_approximation(rate, *parent_rate, GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), |