Quoting Heiko Stuebner (2015-09-30 07:07:38) > From: Douglas Anderson <dianders at chromium.org> > > Let's use DIV_ROUND_CLOSEST for rounding, not just truncating > division. This lets us get closer to the right rate. > > Before this: > set_phase(86) delay_nums=26 reg[0xf000420c]=0x468 actual_degrees=83 > set_phase(89) delay_nums=27 reg[0xf000420c]=0x46c actual_degrees=86 > > After this: > set_phase(86) delay_nums=27 reg[0xf000420c]=0x46c actual_degrees=86 > set_phase(89) delay_nums=28 reg[0xf000420c]=0x470 actual_degrees=90 > > Signed-off-by: Douglas Anderson <dianders at chromium.org> > Signed-off-by: Heiko Stuebner <heiko at sntech.de> Looks good to me. What tree do you want this to go through? Regards, Mike > --- > drivers/clk/rockchip/clk-mmc-phase.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c > index a797d86..bc24e5a 100644 > --- a/drivers/clk/rockchip/clk-mmc-phase.c > +++ b/drivers/clk/rockchip/clk-mmc-phase.c > @@ -69,7 +69,7 @@ static int rockchip_mmc_get_phase(struct clk_hw *hw) > > delay_num = (raw_value & ROCKCHIP_MMC_DELAYNUM_MASK); > delay_num >>= ROCKCHIP_MMC_DELAYNUM_OFFSET; > - degrees += delay_num * factor / 10000; > + degrees += DIV_ROUND_CLOSEST(delay_num * factor, 10000); > } > > return degrees % 360; > @@ -82,7 +82,7 @@ static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees) > u8 nineties, remainder; > u8 delay_num; > u32 raw_value; > - u64 delay; > + u32 delay; > > nineties = degrees / 90; > remainder = (degrees % 90); > @@ -110,12 +110,13 @@ static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees) > * Convert to delay; do a little extra work to make sure we > * don't overflow 32-bit / 64-bit numbers. > */ > - delay = PSECS_PER_SEC; > + delay = 10000000; /* PSECS_PER_SEC / 10000 / 10 */ > delay *= remainder; > - do_div(delay, 10000); > - do_div(delay, (rate / 1000) * 36 * ROCKCHIP_MMC_DELAY_ELEMENT_PSEC); > + delay = DIV_ROUND_CLOSEST(delay, > + (rate / 1000) * 36 * > + (ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10)); > > - delay_num = (u8) min(delay, 255ULL); > + delay_num = (u8) min_t(u32, delay, 255); > > raw_value = delay_num ? ROCKCHIP_MMC_DELAY_SEL : 0; > raw_value |= delay_num << ROCKCHIP_MMC_DELAYNUM_OFFSET; > -- > 2.5.1 >
