diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2019-08-30 16:45:08 +0300 |
|---|---|---|
| committer | Geert Uytterhoeven <geert+renesas@glider.be> | 2019-10-01 11:24:43 +0300 |
| commit | 3e8c1d4cce6b679f4cfd81dfdbbf727f06986aa5 (patch) | |
| tree | a60cba39dd1574590fe9c554e118811ed3b87048 /drivers/clk/renesas | |
| parent | 58256143cff7c2e0a72fe609e797a36b26a3c381 (diff) | |
| download | linux-3e8c1d4cce6b679f4cfd81dfdbbf727f06986aa5.tar.xz | |
clk: renesas: rcar-gen2: Improve arithmetic divisions
- Use div64_ul() instead of div_u64() if the divisor is unsigned long,
to avoid truncation to 32-bit on 64-bit platforms,
- Prefer ULL constant suffixes over casts to u64,
- Prioritize multiplication over division, to increase accuracy.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20190830134515.11925-2-geert+renesas@glider.be
Diffstat (limited to 'drivers/clk/renesas')
| -rw-r--r-- | drivers/clk/renesas/rcar-gen2-cpg.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/clk/renesas/rcar-gen2-cpg.c b/drivers/clk/renesas/rcar-gen2-cpg.c index f596a2dafcf4..c378505830f0 100644 --- a/drivers/clk/renesas/rcar-gen2-cpg.c +++ b/drivers/clk/renesas/rcar-gen2-cpg.c @@ -72,10 +72,10 @@ static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate, if (!prate) prate = 1; - mult = div_u64((u64)rate * 32, prate); + mult = div64_ul(rate * 32ULL, prate); mult = clamp(mult, 1U, 32U); - return *parent_rate / 32 * mult; + return div_u64((u64)*parent_rate * mult, 32); } static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate, @@ -86,7 +86,7 @@ static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate, u32 val, kick; unsigned int i; - mult = div_u64((u64)rate * 32, parent_rate); + mult = div64_ul(rate * 32ULL, parent_rate); mult = clamp(mult, 1U, 32U); if (readl(zclk->kick_reg) & CPG_FRQCRB_KICK) |