From: Dien Pham <[email protected]> This patch improves the calculated value of Z Clock when odd frequency (as 33.33 MHz) is inputted.
Signed-off-by: Dien Pham <[email protected]> Signed-off-by: Takeshi Kihara <[email protected]> Signed-off-by: Yoshihiro Kaneko <[email protected]> --- drivers/clk/renesas/clk-rcar-gen2.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/clk/renesas/clk-rcar-gen2.c b/drivers/clk/renesas/clk-rcar-gen2.c index 00e6aba..7519f71 100644 --- a/drivers/clk/renesas/clk-rcar-gen2.c +++ b/drivers/clk/renesas/clk-rcar-gen2.c @@ -65,7 +65,8 @@ static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw, >> CPG_FRQCRC_ZFC_SHIFT; mult = 32 - val; - return div_u64((u64)parent_rate * mult, 32); + /* Add 1/2 to reduce the math error that raises by math rounding */ + return div_u64((u64)parent_rate * mult + 16, 32); } static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate, @@ -77,7 +78,7 @@ 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 = div_u64((u64)rate * 32 + prate / 2, prate); mult = clamp(mult, 1U, 32U); return *parent_rate / 32 * mult; @@ -91,7 +92,7 @@ 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 = div_u64((u64)rate * 32 + parent_rate / 2, parent_rate); mult = clamp(mult, 1U, 32U); if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK) -- 1.9.1
