Commit 4e53aa2f authored by Nicolai Stange's avatar Nicolai Stange Committed by John Stultz

clocksource: em_sti: Compute rate before registration

With the upcoming NTP correction related rate adjustments to be implemented
in the clockevents core, the latter needs to get informed about every rate
change of a clockevent device made after its registration.

Currently, em_sti violates this requirement in that it registers its
clockevent device with a dummy rate and sets its final rate through
clockevents_config() called from its ->set_state_oneshot().

This patch moves the setting of the clockevent device's rate to its
registration.

I checked all current em_sti users in arch/arm/mach-shmobile and right now,
none of them changes any rate in any clock tree relevant to em_sti after
their respective time_init(). Since all em_sti instances are created after
time_init(), none of them should ever observe any clock rate changes.

- Determine the ->rate value in em_sti_probe() at device probing rather
  than at first usage.
- Set the clockevent device's rate at its registration.
- Although not strictly necessary for the upcoming clockevent core changes,
  set the clocksource's rate at its registration for consistency.
Signed-off-by: default avatarNicolai Stange <nicstange@gmail.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 3814ae09
...@@ -84,9 +84,6 @@ static int em_sti_enable(struct em_sti_priv *p) ...@@ -84,9 +84,6 @@ static int em_sti_enable(struct em_sti_priv *p)
return ret; return ret;
} }
/* configure channel, periodic mode and maximum timeout */
p->rate = clk_get_rate(p->clk);
/* reset the counter */ /* reset the counter */
em_sti_write(p, STI_SET_H, 0x40000000); em_sti_write(p, STI_SET_H, 0x40000000);
em_sti_write(p, STI_SET_L, 0x00000000); em_sti_write(p, STI_SET_L, 0x00000000);
...@@ -205,13 +202,9 @@ static u64 em_sti_clocksource_read(struct clocksource *cs) ...@@ -205,13 +202,9 @@ static u64 em_sti_clocksource_read(struct clocksource *cs)
static int em_sti_clocksource_enable(struct clocksource *cs) static int em_sti_clocksource_enable(struct clocksource *cs)
{ {
int ret;
struct em_sti_priv *p = cs_to_em_sti(cs); struct em_sti_priv *p = cs_to_em_sti(cs);
ret = em_sti_start(p, USER_CLOCKSOURCE); return em_sti_start(p, USER_CLOCKSOURCE);
if (!ret)
__clocksource_update_freq_hz(cs, p->rate);
return ret;
} }
static void em_sti_clocksource_disable(struct clocksource *cs) static void em_sti_clocksource_disable(struct clocksource *cs)
...@@ -240,8 +233,7 @@ static int em_sti_register_clocksource(struct em_sti_priv *p) ...@@ -240,8 +233,7 @@ static int em_sti_register_clocksource(struct em_sti_priv *p)
dev_info(&p->pdev->dev, "used as clock source\n"); dev_info(&p->pdev->dev, "used as clock source\n");
/* Register with dummy 1 Hz value, gets updated in ->enable() */ clocksource_register_hz(cs, p->rate);
clocksource_register_hz(cs, 1);
return 0; return 0;
} }
...@@ -263,7 +255,6 @@ static int em_sti_clock_event_set_oneshot(struct clock_event_device *ced) ...@@ -263,7 +255,6 @@ static int em_sti_clock_event_set_oneshot(struct clock_event_device *ced)
dev_info(&p->pdev->dev, "used for oneshot clock events\n"); dev_info(&p->pdev->dev, "used for oneshot clock events\n");
em_sti_start(p, USER_CLOCKEVENT); em_sti_start(p, USER_CLOCKEVENT);
clockevents_config(&p->ced, p->rate);
return 0; return 0;
} }
...@@ -294,8 +285,7 @@ static void em_sti_register_clockevent(struct em_sti_priv *p) ...@@ -294,8 +285,7 @@ static void em_sti_register_clockevent(struct em_sti_priv *p)
dev_info(&p->pdev->dev, "used for clock events\n"); dev_info(&p->pdev->dev, "used for clock events\n");
/* Register with dummy 1 Hz value, gets updated in ->set_state_oneshot() */ clockevents_config_and_register(ced, p->rate, 2, 0xffffffff);
clockevents_config_and_register(ced, 1, 2, 0xffffffff);
} }
static int em_sti_probe(struct platform_device *pdev) static int em_sti_probe(struct platform_device *pdev)
...@@ -344,6 +334,15 @@ static int em_sti_probe(struct platform_device *pdev) ...@@ -344,6 +334,15 @@ static int em_sti_probe(struct platform_device *pdev)
return ret; return ret;
} }
ret = clk_enable(p->clk);
if (ret < 0) {
dev_err(&p->pdev->dev, "cannot enable clock\n");
clk_unprepare(p->clk);
return ret;
}
p->rate = clk_get_rate(p->clk);
clk_disable(p->clk);
raw_spin_lock_init(&p->lock); raw_spin_lock_init(&p->lock);
em_sti_register_clockevent(p); em_sti_register_clockevent(p);
em_sti_register_clocksource(p); em_sti_register_clocksource(p);
......
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