[V2,2/8] ARM: tegra: config the polarity of the request of sys clock

Commit Message

Joseph Lo Aug. 5, 2013, 11:20 a.m. UTC

When suspending to LP1 mode, the SYSCLK will be clock gated. And different
board may have different polarity of the request of SYSCLK, this patch
configure the polarity from the DT for the board.

Signed-off-by: Joseph Lo <[e-mail]>
---
V2:
* s/inverts/polarity/
---
 arch/arm/mach-tegra/pmc.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Patch

diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c
index 8345fcd..03e6405 100644
--- a/arch/arm/mach-tegra/pmc.c
+++ b/arch/arm/mach-tegra/pmc.c
@@ -27,6 +27,8 @@ 
 #include "pmc.h"
 #include "sleep.h"
 
+#define TEGRA_POWER_SYSCLK_POLARITY	(1 << 10)  /* sys clk polarity */
+#define TEGRA_POWER_SYSCLK_OE		(1 << 11)  /* system clock enable */
 #define TEGRA_POWER_EFFECT_LP0		(1 << 14)  /* LP0 when CPU pwr gated */
 #define TEGRA_POWER_CPU_PWRREQ_POLARITY	(1 << 15)  /* CPU pwr req polarity */
 #define TEGRA_POWER_CPU_PWRREQ_OE	(1 << 16)  /* CPU pwr req enable */
@@ -238,6 +240,20 @@  void tegra_pmc_suspend_init(void)
 	reg = tegra_pmc_readl(PMC_CTRL);
 	reg |= TEGRA_POWER_CPU_PWRREQ_OE;
 	tegra_pmc_writel(reg, PMC_CTRL);
+
+	reg = tegra_pmc_readl(PMC_CTRL);
+
+	if (!pmc_pm_data.sysclkreq_high)
+		reg |= TEGRA_POWER_SYSCLK_POLARITY;
+	else
+		reg &= ~TEGRA_POWER_SYSCLK_POLARITY;
+
+	/* configure the output polarity while the request is tristated */
+	tegra_pmc_writel(reg, PMC_CTRL);
+
+	/* now enable the request */
+	reg |= TEGRA_POWER_SYSCLK_OE;
+	tegra_pmc_writel(reg, PMC_CTRL);
 }
 #endif