diff options
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/clkdev.c | 3 | ||||
| -rw-r--r-- | drivers/clk/rockchip/clk-mmc-phase.c | 50 |
2 files changed, 35 insertions, 18 deletions
diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index c0eaf0973bd2..779b6ff0c7ad 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -333,7 +333,8 @@ int clk_add_alias(const char *alias, const char *alias_dev_name, if (IS_ERR(r)) return PTR_ERR(r); - l = clkdev_create(r, alias, "%s", alias_dev_name); + l = clkdev_create(r, alias, alias_dev_name ? "%s" : NULL, + alias_dev_name); clk_put(r); return l ? 0 : -ENODEV; diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c index 1c8162e5c1ce..2685644826a0 100644 --- a/drivers/clk/rockchip/clk-mmc-phase.c +++ b/drivers/clk/rockchip/clk-mmc-phase.c @@ -47,8 +47,8 @@ static unsigned long rockchip_mmc_recalc(struct clk_hw *hw, #define PSECS_PER_SEC 1000000000000LL /* - * Each fine delay is between 40ps-80ps. Assume each fine delay is 60ps to - * simplify calculations. So 45degs could be anywhere between 33deg and 66deg. + * Each fine delay is between 44ps-77ps. Assume each fine delay is 60ps to + * simplify calculations. So 45degs could be anywhere between 33deg and 57.8deg. */ #define ROCKCHIP_MMC_DELAY_ELEMENT_PSEC 60 @@ -71,7 +71,7 @@ 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; @@ -84,25 +84,41 @@ static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees) u8 nineties, remainder; u8 delay_num; u32 raw_value; - u64 delay; - - /* allow 22 to be 22.5 */ - degrees++; - /* floor to 22.5 increment */ - degrees -= ((degrees) * 10 % 225) / 10; + u32 delay; nineties = degrees / 90; - /* 22.5 multiples */ - remainder = (degrees % 90) / 22; + remainder = (degrees % 90); - delay = PSECS_PER_SEC; - do_div(delay, rate); - /* / 360 / 22.5 */ - do_div(delay, 16); - do_div(delay, ROCKCHIP_MMC_DELAY_ELEMENT_PSEC); + /* + * Due to the inexact nature of the "fine" delay, we might + * actually go non-monotonic. We don't go _too_ monotonic + * though, so we should be OK. Here are options of how we may + * work: + * + * Ideally we end up with: + * 1.0, 2.0, ..., 69.0, 70.0, ..., 89.0, 90.0 + * + * On one extreme (if delay is actually 44ps): + * .73, 1.5, ..., 50.6, 51.3, ..., 65.3, 90.0 + * The other (if delay is actually 77ps): + * 1.3, 2.6, ..., 88.6. 89.8, ..., 114.0, 90 + * + * It's possible we might make a delay that is up to 25 + * degrees off from what we think we're making. That's OK + * though because we should be REALLY far from any bad range. + */ + /* + * Convert to delay; do a little extra work to make sure we + * don't overflow 32-bit / 64-bit numbers. + */ + delay = 10000000; /* PSECS_PER_SEC / 10000 / 10 */ delay *= remainder; - delay_num = (u8) min(delay, 255ULL); + delay = DIV_ROUND_CLOSEST(delay, + (rate / 1000) * 36 * + (ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10)); + + 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; |