[PATCH 12/15] ARM: OMAP: timer: Add suspend-resume callbacks for clockevent device
Kevin Hilman
khilman at deeprootsystems.com
Sat Nov 3 08:15:03 EDT 2012
On 11/02/2012 01:32 PM, Vaibhav Bedia wrote:
> From: Vaibhav Hiremath <hvaibhav at ti.com>
>
> 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 at ti.com>
> Signed-off-by: Vaibhav Bedia <vaibhav.bedia at ti.com>
> ---
> 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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