diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2021-08-12 20:00:22 +0300 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2021-08-12 22:41:47 +0300 |
| commit | 4e7cf74fa3b28fcb43531ca6bc350bf8636e3de6 (patch) | |
| tree | f165057d930f49553cf58e923505a861701a5185 /drivers/clk/rockchip | |
| parent | e73f0f0ee7541171d89f2e2491130c7771ba58d3 (diff) | |
| download | linux-4e7cf74fa3b28fcb43531ca6bc350bf8636e3de6.tar.xz | |
clk: fractional-divider: Export approximation algorithm to the CCF users
At least one user currently duplicates some functions that are provided
by fractional divider module. Let's export approximation algorithm and
replace the open-coded variant.
As a bonus the exported function will get better documentation in place.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20210812170025.67074-1-andriy.shevchenko@linux.intel.com
[sboyd@kernel.org: Add header guard because why not]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/rockchip')
| -rw-r--r-- | drivers/clk/rockchip/clk.c | 17 |
1 files changed, 3 insertions, 14 deletions
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c index 049e5e0b64f6..b7be7e11b0df 100644 --- a/drivers/clk/rockchip/clk.c +++ b/drivers/clk/rockchip/clk.c @@ -22,6 +22,8 @@ #include <linux/regmap.h> #include <linux/reboot.h> #include <linux/rational.h> + +#include "../clk-fractional-divider.h" #include "clk.h" /* @@ -178,10 +180,8 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate, unsigned long *m, unsigned long *n) { - struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long p_rate, p_parent_rate; struct clk_hw *p_parent; - unsigned long scale; p_rate = clk_hw_get_rate(clk_hw_get_parent(hw)); if ((rate * 20 > p_rate) && (p_rate % rate != 0)) { @@ -190,18 +190,7 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, *parent_rate = p_parent_rate; } - /* - * 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; - - rational_best_approximation(rate, *parent_rate, - GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), - m, n); + clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n); } static struct clk *rockchip_clk_register_frac_branch( |