[PATCH v2 04/18] clocksource: samsung_pwm_timer: Cache clocksource register address
From: Tomasz Figa <hidden>
Date: 2013-06-20 22:12:49
Also in:
linux-pwm, linux-samsung-soc
Subsystem:
arm/samsung s3c, s5p and exynos arm architectures, clocksource, clockevent drivers, the rest · Maintainers:
Krzysztof Kozlowski, Daniel Lezcano, Thomas Gleixner, Linus Torvalds
Instead of calculating register every time the timer should be read, we can just do it one time at initialization and store the address in driver data. Signed-off-by: Tomasz Figa <redacted> --- drivers/clocksource/samsung_pwm_timer.c | 33 ++++++++------------------------- 1 file changed, 8 insertions(+), 25 deletions(-)
diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
index 553115b..d361b5e 100644
--- a/drivers/clocksource/samsung_pwm_timer.c
+++ b/drivers/clocksource/samsung_pwm_timer.c@@ -54,6 +54,7 @@ EXPORT_SYMBOL(samsung_pwm_lock); struct samsung_pwm_clocksource { void __iomem *base; + void __iomem *source_reg; unsigned int irq[SAMSUNG_PWM_NUM]; struct samsung_pwm_variant variant;
@@ -286,23 +287,6 @@ static void __init samsung_clockevent_init(void) } } -static void __iomem *samsung_timer_reg(void) -{ - switch (pwm.source_id) { - case 0: - case 1: - case 2: - case 3: - return pwm.base + pwm.source_id * 0x0c + 0x14; - - case 4: - return pwm.base + 0x40; - - default: - BUG(); - } -} - /* * Override the global weak sched_clock symbol with this * local implementation which uses the clocksource to get some
@@ -312,17 +296,11 @@ static void __iomem *samsung_timer_reg(void) */ static u32 notrace samsung_read_sched_clock(void) { - void __iomem *reg = samsung_timer_reg(); - - if (!reg) - return 0; - - return ~__raw_readl(reg); + return ~__raw_readl(pwm.source_reg); } static void __init samsung_clocksource_init(void) { - void __iomem *reg = samsung_timer_reg(); unsigned long pclk; unsigned long clock_rate; int ret;
@@ -337,10 +315,15 @@ static void __init samsung_clocksource_init(void) samsung_time_setup(pwm.source_id, pwm.tcnt_max); samsung_time_start(pwm.source_id, true); + if (pwm.source_id == 4) + pwm.source_reg = pwm.base + 0x40; + else + pwm.source_reg = pwm.base + pwm.source_id * 0x0c + 0x14; + setup_sched_clock(samsung_read_sched_clock, pwm.variant.bits, clock_rate); - ret = clocksource_mmio_init(reg, "samsung_clocksource_timer", + ret = clocksource_mmio_init(pwm.source_reg, "samsung_clocksource_timer", clock_rate, 250, pwm.variant.bits, clocksource_mmio_readl_down); if (ret)
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1.8.2.1