Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4351f19a authored by Douglas Anderson's avatar Douglas Anderson Committed by Ulf Hansson
Browse files

clk: rockchip: Make calculations use rounding 



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: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Acked-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent f0232063

drivers/clk/rockchip/clk-mmc-phase.c

+7 −6
Original line number Diff line number Diff line
@@ -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;