From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [RFC v2 12/18] ARM: OMAP2+: timer: Add suspend-resume callbacks for clockevent device Date: Thu, 17 Jan 2013 12:45:43 -0600 Message-ID: <50F846D7.8060509@ti.com> References: <1356959231-17335-1-git-send-email-vaibhav.bedia@ti.com> <1356959231-17335-13-git-send-email-vaibhav.bedia@ti.com> <50EC37FE.705@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from comal.ext.ti.com ([198.47.26.152]:36717 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752746Ab3AQSpv (ORCPT ); Thu, 17 Jan 2013 13:45:51 -0500 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Bedia, Vaibhav" Cc: "Shilimkar, Santosh" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "tony@atomide.com" , "khilman@deeprootsystems.com" , "Cousson, Benoit" , Paul Walmsley , "Hiremath, Vaibhav" On 01/10/2013 10:37 PM, Bedia, Vaibhav wrote: > On Tue, Jan 08, 2013 at 20:45:10, Shilimkar, Santosh wrote: >> On Monday 31 December 2012 06:37 PM, Vaibhav Bedia wrote: >>> 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. >>> >>> 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 >>> Cc: Santosh Shilimkar >>> Cc: Benoit Cousson >>> Cc: Paul Walmsley >>> Cc: Kevin Hilman >>> Cc: Vaibhav Hiremath >>> Cc: Jon Hunter >>> --- >>> v1->v2: >>> Get rid of harcoded timer id. >>> Note: since a platform device is not created for these timer >>> instances and because there's very minimal change needed for >>> restarting the timer a full blown context save and restore >>> has been skipped. >>> >>> arch/arm/mach-omap2/timer.c | 33 +++++++++++++++++++++++++++++++++ >>> 1 files changed, 33 insertions(+), 0 deletions(-) >>> >>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c >>> index 691aa67..38f9cbc 100644 >>> --- a/arch/arm/mach-omap2/timer.c >>> +++ b/arch/arm/mach-omap2/timer.c >>> @@ -128,6 +128,36 @@ 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", clkev.id); >>> + oh = omap_hwmod_lookup(name); >>> + if (!oh) >>> + return; >>> + >>> + __omap_dm_timer_stop(&clkev, 1, clkev.rate); >>> + 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", clkev.id); >>> + 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); >>> +} >>> + >> Am still bit uncomfortable with direct hwmod usage in the suspend/resmue >> hooks. >> >> Jon, Any alternatives you can think of ? >> > > Jon, > > Any suggestions here? Sorry completed this missed this! Unfortunately, I don't have any good suggestions here. However, I am wondering if the suspend/resume handlers can just be calls to omap_hwmod_idle/enable and we can remove these __omap_dm_timer_xxxx calls (I don't think they are needed). Furthermore, my understanding is this is only needed for AM335x (per the changelog), and so we should not add suspend/resume handlers for all OMAP2+ based devices. Cheers Jon From mboxrd@z Thu Jan 1 00:00:00 1970 From: jon-hunter@ti.com (Jon Hunter) Date: Thu, 17 Jan 2013 12:45:43 -0600 Subject: [RFC v2 12/18] ARM: OMAP2+: timer: Add suspend-resume callbacks for clockevent device In-Reply-To: References: <1356959231-17335-1-git-send-email-vaibhav.bedia@ti.com> <1356959231-17335-13-git-send-email-vaibhav.bedia@ti.com> <50EC37FE.705@ti.com> Message-ID: <50F846D7.8060509@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/10/2013 10:37 PM, Bedia, Vaibhav wrote: > On Tue, Jan 08, 2013 at 20:45:10, Shilimkar, Santosh wrote: >> On Monday 31 December 2012 06:37 PM, Vaibhav Bedia wrote: >>> 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. >>> >>> 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 >>> Cc: Santosh Shilimkar >>> Cc: Benoit Cousson >>> Cc: Paul Walmsley >>> Cc: Kevin Hilman >>> Cc: Vaibhav Hiremath >>> Cc: Jon Hunter >>> --- >>> v1->v2: >>> Get rid of harcoded timer id. >>> Note: since a platform device is not created for these timer >>> instances and because there's very minimal change needed for >>> restarting the timer a full blown context save and restore >>> has been skipped. >>> >>> arch/arm/mach-omap2/timer.c | 33 +++++++++++++++++++++++++++++++++ >>> 1 files changed, 33 insertions(+), 0 deletions(-) >>> >>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c >>> index 691aa67..38f9cbc 100644 >>> --- a/arch/arm/mach-omap2/timer.c >>> +++ b/arch/arm/mach-omap2/timer.c >>> @@ -128,6 +128,36 @@ 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", clkev.id); >>> + oh = omap_hwmod_lookup(name); >>> + if (!oh) >>> + return; >>> + >>> + __omap_dm_timer_stop(&clkev, 1, clkev.rate); >>> + 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", clkev.id); >>> + 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); >>> +} >>> + >> Am still bit uncomfortable with direct hwmod usage in the suspend/resmue >> hooks. >> >> Jon, Any alternatives you can think of ? >> > > Jon, > > Any suggestions here? Sorry completed this missed this! Unfortunately, I don't have any good suggestions here. However, I am wondering if the suspend/resume handlers can just be calls to omap_hwmod_idle/enable and we can remove these __omap_dm_timer_xxxx calls (I don't think they are needed). Furthermore, my understanding is this is only needed for AM335x (per the changelog), and so we should not add suspend/resume handlers for all OMAP2+ based devices. Cheers Jon