From patchwork Tue Jun 18 17:07:03 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep KarkadaNagesha X-Patchwork-Id: 2744371 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 119F09F8E1 for ; Tue, 18 Jun 2013 17:10:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E1D37204B2 for ; Tue, 18 Jun 2013 17:10:49 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 73EEF204CE for ; Tue, 18 Jun 2013 17:10:47 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UozOQ-0008Fm-M6; Tue, 18 Jun 2013 17:08:33 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UozNz-0006Cp-6R; Tue, 18 Jun 2013 17:08:03 +0000 Received: from service87.mimecast.com ([91.220.42.44]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UozNO-00068h-Hj for linux-arm-kernel@lists.infradead.org; Tue, 18 Jun 2013 17:07:28 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Tue, 18 Jun 2013 18:07:04 +0100 Received: from e103737-lin.cambridge.arm.com ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.0); Tue, 18 Jun 2013 18:07:02 +0100 From: Sudeep KarkadaNagesha To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] drivers: clocksource: add CPU PM notifier for ARM architected timer Date: Tue, 18 Jun 2013 18:07:03 +0100 Message-Id: <1371575223-21702-5-git-send-email-Sudeep.KarkadaNagesha@arm.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1371575223-21702-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> References: <1371575223-21702-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> X-OriginalArrivalTime: 18 Jun 2013 17:07:02.0888 (UTC) FILETIME=[40AC7E80:01CE6C46] X-MC-Unique: 113061818070400301 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130618_130726_842446_F603CCE6 X-CRM114-Status: GOOD ( 11.70 ) X-Spam-Score: -2.6 (--) Cc: mark.rutland@arm.com, linux@arm.linux.org.uk, Sudeep KarkadaNagesha , catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, tglx@linutronix.de X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sudeep KarkadaNagesha Few control settings done in architected timer as part of initialisation are lost when CPU enters deeper power states. They need to be re-initialised when the CPU is (warm)reset again. This patch moves all such initialisation into separate function that can be used both in cold and warm CPU reset paths. It also adds CPU PM notifiers to do the timer initialisation on warm resets. Signed-off-by: Sudeep KarkadaNagesha Reviewed-by: Lorenzo Pieralisi Reviewed-by: Will Deacon --- drivers/clocksource/arm_arch_timer.c | 51 +++++++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 7 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 11aaf06..1c691b1 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -123,10 +124,20 @@ static int arch_timer_set_next_event_phys(unsigned long evt, return 0; } -static int __cpuinit arch_timer_setup(struct clock_event_device *clk) +static void arch_timer_initialise(void) { int evt_stream_div, pos; + /* Find the closest power of two to the divisor */ + evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ; + pos = fls(evt_stream_div); + if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) + pos--; + arch_counter_set_user_access(min(pos, 15)); +} + +static int __cpuinit arch_timer_setup(struct clock_event_device *clk) +{ clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP; clk->name = "arch_sys_timer"; clk->rating = 450; @@ -155,12 +166,7 @@ static int __cpuinit arch_timer_setup(struct clock_event_device *clk) enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0); } - /* Find the closest power of two to the divisor */ - evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ; - pos = fls(evt_stream_div); - if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) - pos--; - arch_counter_set_user_access(min(pos, 15)); + arch_timer_initialise(); return 0; } @@ -267,6 +273,31 @@ static struct notifier_block arch_timer_cpu_nb __cpuinitdata = { .notifier_call = arch_timer_cpu_notify, }; +#ifdef CONFIG_CPU_PM +static int arch_timer_cpu_pm_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + if (action == CPU_PM_EXIT) + arch_timer_initialise(); + + return NOTIFY_OK; +} + +static struct notifier_block arch_timer_cpu_pm_notifier = { + .notifier_call = arch_timer_cpu_pm_notify, +}; + +static int __init arch_timer_cpu_pm_init(void) +{ + return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier); +} +#else +static int __init arch_timer_cpu_pm_init(void) +{ + return 0; +} +#endif + static int __init arch_timer_register(void) { int err; @@ -316,11 +347,17 @@ static int __init arch_timer_register(void) if (err) goto out_free_irq; + err = arch_timer_cpu_pm_init(); + if (err) + goto out_unreg_notify; + /* Immediately configure the timer on the boot CPU */ arch_timer_setup(this_cpu_ptr(arch_timer_evt)); return 0; +out_unreg_notify: + unregister_cpu_notifier(&arch_timer_cpu_nb); out_free_irq: if (arch_timer_use_virtual) free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);