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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2021-08-12 20:00:22 +0300
committerStephen Boyd <sboyd@kernel.org>2021-08-12 22:41:47 +0300
commit4e7cf74fa3b28fcb43531ca6bc350bf8636e3de6 (patch)
treef165057d930f49553cf58e923505a861701a5185 /drivers/clk/rockchip
parente73f0f0ee7541171d89f2e2491130c7771ba58d3 (diff)
downloadlinux-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.c17
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(