linux-kernel - [PATCH v4 4/5] ARM: EXYNOS: PM: fix register setup for AFTR mode code

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Message-id: <1407174345-31213-5-git-send-email-b.zolnierkie@samsung.com>
Date:	Mon, 04 Aug 2014 19:45:44 +0200
From:	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
To:	Kukjin Kim <kgene.kim@...sung.com>
Cc:	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Tomasz Figa <t.figa@...sung.com>,
	Sachin Kamat <sachin.kamat@...aro.org>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	linux-samsung-soc@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, linaro-kernel@...ts.linaro.org,
	b.zolnierkie@...sung.com
Subject: [PATCH v4 4/5] ARM: EXYNOS: PM: fix register setup for AFTR mode code

Add S5P_CENTRAL_SEQ_OPTION register setup to cpuidle AFTR mode code
by moving the relevant code from exynos_pm_suspend() (used only by
suspend) to exynos_pm_central_suspend() (used by both suspend and
AFTR).  Without this setup AFTR mode doesn't show any benefit over
WFI one (at least on Exynos4412 SoC).  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@...sung.com>
Acked-by: Kyungmin Park <kyungmin.park@...sung.com>
---
 arch/arm/mach-exynos/pm.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index a61b85c..4e32cc6 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -169,6 +169,10 @@ static void exynos_pm_central_suspend(void)
 	tmp = pmu_raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 	tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
 	pmu_raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
+
+	/* Setting SEQ_OPTION register */
+	pmu_raw_writel(S5P_USE_STANDBY_WFI0 | S5P_USE_STANDBY_WFE0,
+		       S5P_CENTRAL_SEQ_OPTION);
 }
 
 static int exynos_pm_central_resume(void)
@@ -291,15 +295,8 @@ static void exynos_pm_prepare(void)
 
 static int exynos_pm_suspend(void)
 {
-	unsigned long tmp;
-
 	exynos_pm_central_suspend();
 
-	/* Setting SEQ_OPTION register */
-
-	tmp = (S5P_USE_STANDBY_WFI0 | S5P_USE_STANDBY_WFE0);
-	pmu_raw_writel(tmp, S5P_CENTRAL_SEQ_OPTION);
-
 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
 		exynos_cpu_save_register();
 
-- 
1.8.2.3

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