[PATCH v3] ARM: tegra: cpuidle: use firmware for power down

From: Alexandre Courbot
Date: Tue Feb 11 2014 - 21:43:59 EST


Attempt to invoke the prepare_idle() and do_idle() firmware calls
to power down a CPU so an underlying firmware gets informed of
the idle operation and performs it by itself if designed in such a way.

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
---
This is the only v3 patch in the series.

Changes since v2:
- Use an if statement instead of a switch to handle the single return
code we need to care about.

arch/arm/mach-tegra/cpuidle-tegra114.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
index e0b87300243d..b5fb7c110c64 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra114.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
@@ -19,6 +19,7 @@
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/clockchips.h>
+#include <asm/firmware.h>

#include <asm/cpuidle.h>
#include <asm/suspend.h>
@@ -45,7 +46,11 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev,

clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);

- cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
+ call_firmware_op(prepare_idle);
+
+ /* Do suspend by ourselves if the firmware does not implement it */
+ if (call_firmware_op(do_idle) == -ENOSYS)
+ cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);

clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);

--
1.8.5.4

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