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Code Issues Releases Wiki Activity

clocksource: samsung_pwm_timer: Cache clocksource register address

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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 <tomasz.figa@gmail.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Mark Brown <broonie@linaro.org>
Tested-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Tomasz Figa 2013-06-17 00:07:03 +02:00
parent ceea124103
commit 61d7e2056e
1 changed files with 8 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

33
drivers/clocksource/samsung_pwm_timer.c
View file

@ -65,6 +65,7 @@ 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;
@ -297,23 +298,6 @@ 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
@ -323,17 +307,11 @@ 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;
@ -348,10 +326,15 @@ 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)