[PATCH v2 6/7] ARM: EXYNOS: PM: fix register setup on EXYNOS4x12 for AFTR mode code

Bartlomiej Zolnierkiewicz
2014-06-02T12:35:42Z

Add S5P_CENTRAL_SEQ_OPTION register setup for EXYNOS4x12 to AFTR
mode code. Without this setup AFTR mode doesn't show any benefit
over WFI one. When this setup is applied AFTR mode reduces power
consumption by ~12% (as measured on Trats2 board).

This change is a preparation for adding secure firmware support to
EXYNOS cpuidle driver.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
---
arch/arm/mach-exynos/pm.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index aeff99e..0fb9a5a 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -456,6 +456,10 @@ static int exynos_cpu_pm_notifier(struct notifier_block *self,
case CPU_PM_ENTER:
if (cpu == 0) {
exynos_pm_central_suspend();
+ if (soc_is_exynos4212() || soc_is_exynos4412())
+ __raw_writel(S5P_USE_STANDBY_WFI0 |
+ S5P_USE_STANDBY_WFE0,
+ S5P_CENTRAL_SEQ_OPTION);
exynos_cpu_save_register();
}
break;
--
1.8.2.3