On 11/02/2012 01:32 PM, Vaibhav Bedia wrote:
From: Vaibhav Hiremath <hvaibhav@xxxxxx>
The current OMAP timer code registers two timers -
one as clocksource and one as clockevent.
AM33XX has only one usable timer in the WKUP domain
so one of the timers needs suspend-resume support
to restore the configuration to pre-suspend state.
The changelog describes "what", but doesn't answer "why?"
commit adc78e6 (timekeeping: Add suspend and resume
of clock event devices) introduced .suspend and .resume
callbacks for clock event devices. Leverages these
callbacks to have AM33XX clockevent timer which is
in not in WKUP domain to behave properly across system
suspend.
You say it behaves properly without describing what improper
behavior is happening.
Signed-off-by: Vaibhav Hiremath <hvaibhav@xxxxxx>
Signed-off-by: Vaibhav Bedia <vaibhav.bedia@xxxxxx>
---
arch/arm/mach-omap2/timer.c | 31 +++++++++++++++++++++++++++++++
1 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 6584ee0..e8781fd 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -135,6 +135,35 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
}
}
+static void omap_clkevt_suspend(struct clock_event_device *unused)
+{
+ char name[10];
+ struct omap_hwmod *oh;
+
+ sprintf(name, "timer%d", 2);
hard-coded timer ID? the rest of the code is using timer_id
+ oh = omap_hwmod_lookup(name);
+ if (!oh)
+ return;
+
+ omap_hwmod_idle(oh);
+}
+
+static void omap_clkevt_resume(struct clock_event_device *unused)
+{
+ char name[10];
+ struct omap_hwmod *oh;
+
+ sprintf(name, "timer%d", 2);
+ oh = omap_hwmod_lookup(name);
+ if (!oh)
+ return;
+
+ omap_hwmod_enable(oh);
+ __omap_dm_timer_load_start(&clkev,
+ OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
+ __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
+}
I don't like the sprintf/hwmod_lookup for every suspend/resume. Just add a
new file-global static 'struct omap_hwmod clockevt_oh' along side
clockevent_gpt,
and assign it at init time in dmtimer_init_one. Then you don't have to
do this
sprintf/lookup on every suspend/resume.
Kevin
static struct clock_event_device clockevent_gpt = {
.name = "gp_timer",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
@@ -142,6 +171,8 @@ static struct clock_event_device clockevent_gpt = {
.rating = 300,
.set_next_event = omap2_gp_timer_set_next_event,
.set_mode = omap2_gp_timer_set_mode,
+ .suspend = omap_clkevt_suspend,
+ .resume = omap_clkevt_resume,
};
static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
--
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