[PATCH v5 09/14] ARM: mvebu: Allow to power down L2 cache controller in idle mode

[Gregory CLEMENT]

This commit adds a function which adjusts the PMSU configuration to
automatically power down the L2 and coherency fabric when we enter a
certain idle state.

This feature is part of the Power Management Service Unit of the
Armada 370 and Armada XP SoCs.

Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
---
 arch/arm/mach-mvebu/pmsu.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index 865bcb651e01..3cfb56f980f3 100644
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -30,8 +30,15 @@ static void __iomem *pmsu_reset_base;
 #define PMSU_BASE_OFFSET    0x100
 #define PMSU_REG_SIZE	    0x1000
 
-#define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu)	((cpu * 0x100) + 0x124)
-#define PMSU_RESET_CTL_OFFSET(cpu)		(cpu * 0x8)
+/* PMSU MP registers */
+#define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x124)
+
+/* PMSU reset registers */
+#define PMSU_RESET_CTL_OFFSET(cpu)	    (cpu * 0x8)
+
+/* PMSU fabric registers */
+#define L2C_NFABRIC_PM_CTL		    0x4
+#define L2C_NFABRIC_PM_CTL_PWR_DOWN		BIT(20)
 
 static struct of_device_id of_pmsu_table[] = {
 	{
@@ -111,4 +118,17 @@ static int __init armada_370_xp_pmsu_init(void)
 	return 0;
 }
 
+static void armada_370_xp_pmsu_enable_l2_powerdown_onidle(void)
+{
+	u32 reg;
+
+	if (pmsu_mp_base == NULL)
+		return;
+
+	/* Enable L2 & Fabric powerdown in Deep-Idle mode - Fabric */
+	reg = readl(pmsu_mp_base + L2C_NFABRIC_PM_CTL);
+	reg |= L2C_NFABRIC_PM_CTL_PWR_DOWN;
+	writel(reg, pmsu_mp_base + L2C_NFABRIC_PM_CTL);
+}
+
 early_initcall(armada_370_xp_pmsu_init);
-- 
1.8.1.2