linux-kernel - [PATCH v2] ARM: tegra: cpuidle: implement cpuidle_state.enter

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Message-Id: <1431941933-18574-1-git-send-email-tomeu.vizoso@collabora.com>
Date:	Mon, 18 May 2015 11:38:51 +0200
From:	Tomeu Vizoso <tomeu.vizoso@...labora.com>
To:	linux-pm@...r.kernel.org
Cc:	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	Tomeu Vizoso <tomeu.vizoso@...labora.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Russell King <linux@....linux.org.uk>,
	Stephen Warren <swarren@...dotorg.org>,
	Thierry Reding <thierry.reding@...il.com>,
	Alexandre Courbot <gnurou@...il.com>,
	Kukjin Kim <kgene.kim@...sung.com>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	linux-arm-kernel@...ts.infradead.org, linux-tegra@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v2] ARM: tegra: cpuidle: implement cpuidle_state.enter_freeze()

This callback is expected to do the same as enter() only that won't
re-enable interrupts on exit.

It will be called when the system goes to suspend-to-idle and will
reduce power usage because CPUs won't be awaken for unnecessary IRQs.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@...labora.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

---

v2:	* Disable FIQs also when suspending-to-idle
---
 arch/arm/mach-tegra/cpuidle-tegra114.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
index 155807f..e7c4359 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra114.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
@@ -35,32 +35,42 @@
 #endif
 
 #ifdef CONFIG_PM_SLEEP
-static int tegra114_idle_power_down(struct cpuidle_device *dev,
-				    struct cpuidle_driver *drv,
-				    int index)
+static void tegra114_idle_power_down(void)
 {
 	local_fiq_disable();
 
 	tegra_set_cpu_in_lp2();
 	cpu_pm_enter();
 
-	tick_broadcast_enter();
-
 	call_firmware_op(prepare_idle);
 
 	/* Do suspend by ourselves if the firmware does not implement it */
 	if (call_firmware_op(do_idle, 0) == -ENOSYS)
 		cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
 
-	tick_broadcast_exit();
-
 	cpu_pm_exit();
 	tegra_clear_cpu_in_lp2();
 
 	local_fiq_enable();
+}
+
+static int tegra114_idle_enter(struct cpuidle_device *dev,
+			       struct cpuidle_driver *drv,
+			       int index)
+{
+	tick_broadcast_enter();
+	tegra114_idle_power_down();
+	tick_broadcast_exit();
 
 	return index;
 }
+
+static void tegra114_idle_enter_freeze(struct cpuidle_device *dev,
+				       struct cpuidle_driver *drv,
+				       int index)
+{
+	tegra114_idle_power_down();
+}
 #endif
 
 static struct cpuidle_driver tegra_idle_driver = {
@@ -71,7 +81,8 @@ static struct cpuidle_driver tegra_idle_driver = {
 		[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
 #ifdef CONFIG_PM_SLEEP
 		[1] = {
-			.enter			= tegra114_idle_power_down,
+			.enter			= tegra114_idle_enter,
+			.enter_freeze		= tegra114_idle_enter_freeze,
 			.exit_latency		= 500,
 			.target_residency	= 1000,
 			.power_usage		= 0,
-- 
2.4.0

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