From: d-gerlach@ti•com (Dave Gerlach)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4 03/11] ARM: OMAP2+: timer: Add suspend-resume callbacks for clkevent device
Date: Tue, 15 Jul 2014 14:10:55 -0500 [thread overview]
Message-ID: <53C57CBF.2090507@ti.com> (raw)
In-Reply-To: <20140715064807.GJ20068@atomide.com>
On 07/15/2014 01:48 AM, Tony Lindgren wrote:
> * Dave Gerlach <d-gerlach@ti•com> [140714 10:44]:
>> Santosh, Tony,
>>
>> On 07/14/2014 09:37 AM, Santosh Shilimkar wrote:
>>> On Monday 14 July 2014 07:15 AM, Tony Lindgren wrote:
>>>> * Dave Gerlach <d-gerlach@ti•com> [140710 19:59]:
>>>>> From: Vaibhav Bedia <vaibhav.bedia@ti•com>
>>>>>
>>>>> OMAP timer code registers two timers - one as clocksource
>>>>> and one as clockevent. Since AM33XX has only one usable timer
>>>>> in the WKUP domain one of the timers needs suspend-resume
>>>>> support to restore the configuration to pre-suspend state.
>>>>>
>>>>> 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.
>>>>>
>>>>> Signed-off-by: Vaibhav Bedia <vaibhav.bedia@ti•com>
>>>>> Signed-off-by: Dave Gerlach <d-gerlach@ti•com>
>>>>> ---
>>>>> v3->v4:
>>>>> Only use for am33xx soc now.
>>>>>
>>>>> arch/arm/mach-omap2/timer.c | 28 ++++++++++++++++++++++++++++
>>>>> 1 file changed, 28 insertions(+)
>>>>>
>>>>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
>>>>> index 43d03fb..6fc1748 100644
>>>>> --- a/arch/arm/mach-omap2/timer.c
>>>>> +++ b/arch/arm/mach-omap2/timer.c
>>>>> @@ -128,6 +128,29 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
>>>>> }
>>>>> }
>>>>>
>>>>> +static void omap_clkevt_suspend(struct clock_event_device *unused)
>>>>> +{
>>>>> + struct omap_hwmod *oh;
>>>>> +
>>>>> + oh = omap_hwmod_lookup(clockevent_gpt.name);
>>>>> + if (!oh)
>>>>> + return;
>>>>> +
>>>>> + omap_hwmod_idle(oh);
>>>>> +}
>>>>> +
>>>>> +static void omap_clkevt_resume(struct clock_event_device *unused)
>>>>> +{
>>>>> + struct omap_hwmod *oh;
>>>>> +
>>>>> + oh = omap_hwmod_lookup(clockevent_gpt.name);
>>>>> + if (!oh)
>>>>> + return;
>>>>> +
>>>>> + omap_hwmod_enable(oh);
>>>>> + __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
>>>>> +}
>>>>> +
>>>>
>>>> This is going to make moving the timer code into drivers one step
>>>> tougher to do. And you don't need to look up the hwmod entry every
>>>> time, just initialize it during the init.
>>
>> Yes you are right about looking up only at init I need to change that. I
>> agree that this makes moving the timers harder but I'm not sure there's any
>> way around this. I attempted to use the omap_device layer here but there is
>> no device at all created here, it does not hook into the normal PM layer
>> through omap_device. This clock must be shut off as it sits in the
>> peripheral power domain and any active clock within the domain will prevent
>> suspend from happening, so we end up with a platform specific issue here. It
>> seems that the only way I can get to the clock is through the hwmod.
>
> It's best to register these kind of functions as platform_data
> in pdata-quirks.c auxdata. That way when this moves to live
> in drivers/clocksource the driver does not need to know anything
> about the interconnect specific registers.
>
> Also, please don't use Linux generic names here.. Maybe use
> omap_clkevt_idle/unidle? The linux suspend and resume hooks
> and runtime PM could all use these functions then.
Ok to both of the above, I definitely like your suggestion better.
Regards,
Dave
>
>>>>> + if (soc_is_am33xx()) {
>>>>> + clockevent_gpt.suspend = omap_clkevt_suspend;
>>>>> + clockevent_gpt.resume = omap_clkevt_resume;
>>>>> + }
>>>>> +
>>>>
>>>> Maybe try to set up things so we initialize the SoC specific
>>>> timer suspend and resume functions in mach-omap2/timer.c
>>>> in a way where eventually the device driver can easily use
>>>> them?
>>>>
>>> +1. I had similar comments on the previous version too.
>>
>> This was my attempt to make things specific to only am335x based on
>> Santosh's previous comments as last time they were populated for every
>> device even when unneeded. These are not standard suspend/resume handlers,
>> they are specific to clock event. I know there will always need to be at
>> least some code here for the early timer init based on previous timer
>> cleanup series I've seen, so perhaps I could hook it in there when the time
>> comes?
>
> Well just adding a minimal include/linux/platform_data/timer-omap.h
> to pass those function pointers to the driver should do the trick.
>
> Regards,
>
> Tony
>
next prev parent reply other threads:[~2014-07-15 19:10 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-11 2:55 [PATCH v4 00/11] ARM: OMAP2+: AM33XX: Add suspend-resume support Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 01/11] ARM: omap: edma: add suspend suspend/resume hooks Dave Gerlach
2014-07-14 11:05 ` Tony Lindgren
2014-07-14 17:47 ` Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 02/11] memory: emif: Move EMIF register defines to include/linux/ Dave Gerlach
2014-07-14 11:12 ` Tony Lindgren
2014-07-14 17:42 ` Dave Gerlach
2014-07-15 6:38 ` Tony Lindgren
2014-07-16 2:44 ` Dave Gerlach
2014-07-16 8:33 ` Tony Lindgren
2014-07-11 2:55 ` [PATCH v4 03/11] ARM: OMAP2+: timer: Add suspend-resume callbacks for clkevent device Dave Gerlach
2014-07-14 11:15 ` Tony Lindgren
2014-07-14 14:37 ` Santosh Shilimkar
2014-07-14 17:42 ` Dave Gerlach
2014-07-15 6:48 ` Tony Lindgren
2014-07-15 19:10 ` Dave Gerlach [this message]
2014-07-16 20:17 ` Dave Gerlach
2014-07-17 8:16 ` Tony Lindgren
2014-07-11 2:55 ` [PATCH v4 04/11] ARM: OMAP2+: Use pdata-quirks for wkup_m3 deassert_hardreset Dave Gerlach
2014-07-14 18:48 ` Suman Anna
2014-07-11 2:55 ` [PATCH v4 05/11] Documentation: dt: add ti,am3353_wkup_m3 bindings Dave Gerlach
2014-07-14 14:41 ` [PATCH v4 05/11] Documentation: dt: add ti, am3353_wkup_m3 bindings Santosh Shilimkar
2014-07-14 16:33 ` Suman Anna
2014-07-14 17:45 ` Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 06/11] remoteproc: wkup_m3: Add wkup_m3 remote proc driver Dave Gerlach
2014-07-14 14:54 ` Santosh Shilimkar
2014-07-14 17:43 ` Dave Gerlach
2014-07-14 19:07 ` Suman Anna
2014-07-14 21:09 ` Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 07/11] ARM: dts: am33xx: Update wkup_m3 node Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 08/11] ARM: OMAP2+: AM33XX: Reserve memory to comply with EMIF spec Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 09/11] ARM: OMAP2+: AM33XX: Add assembly code for PM operations Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 10/11] ARM: OMAP2+: AM33XX: Basic suspend resume support Dave Gerlach
2014-09-08 22:30 ` Kevin Hilman
2014-09-09 10:31 ` Ohad Ben-Cohen
2014-09-09 19:59 ` Suman Anna
2014-09-09 20:28 ` Dave Gerlach
2014-09-09 21:10 ` Kevin Hilman
2014-09-10 21:19 ` Dave Gerlach
2014-09-16 15:08 ` Ohad Ben-Cohen
2014-09-16 16:14 ` Suman Anna
2014-09-17 13:37 ` Ohad Ben-Cohen
2014-09-25 19:42 ` Dave Gerlach
2014-07-11 2:55 ` [PATCH v4 11/11] ARM: OMAP2+: AM33XX: Hookup AM33XX PM code into OMAP builds Dave Gerlach
2014-07-14 11:21 ` Tony Lindgren
2014-07-14 17:46 ` Dave Gerlach
2014-07-11 7:59 ` [PATCH v4 00/11] ARM: OMAP2+: AM33XX: Add suspend-resume support Daniel Mack
2014-07-11 17:24 ` Dave Gerlach
2014-07-11 15:30 ` Andre Heider
2014-07-11 17:31 ` Dave Gerlach
2014-07-14 9:37 ` Andre Heider
2014-07-14 11:24 ` Tony Lindgren
2014-07-14 17:47 ` Dave Gerlach
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