ARM: OMAP4: PM: Add L2X0 cache lowpower support

When MPUSS hits off-mode, L2 cache is lost. This patch adds L2X0
necessary maintenance operations and context restoration in the
low power code.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 40 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
index f9bb2b3d977b..907a048fe5e9 100644
--- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
@@ -49,6 +49,7 @@
 #include <asm/system.h>
 #include <asm/pgalloc.h>
 #include <asm/suspend.h>
+#include <asm/hardware/cache-l2x0.h>
 
 #include <plat/omap44xx.h>
 
@@ -63,10 +64,12 @@ struct omap4_cpu_pm_info {
 	struct powerdomain *pwrdm;
 	void __iomem *scu_sar_addr;
 	void __iomem *wkup_sar_addr;
+	void __iomem *l2x0_sar_addr;
 };
 
 static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
 static struct powerdomain *mpuss_pd;
+static void __iomem *sar_base;
 
 /*
  * Program the wakeup routine address for the CPU0 and CPU1
@@ -135,6 +138,36 @@ static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
 	__raw_writel(scu_pwr_st, pm_info->scu_sar_addr);
 }
 
+/*
+ * Store the CPU cluster state for L2X0 low power operations.
+ */
+static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
+{
+	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
+
+	__raw_writel(save_state, pm_info->l2x0_sar_addr);
+}
+
+/*
+ * Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
+ * in every restore MPUSS OFF path.
+ */
+#ifdef CONFIG_CACHE_L2X0
+static void save_l2x0_context(void)
+{
+	u32 val;
+	void __iomem *l2x0_base = omap4_get_l2cache_base();
+
+	val = __raw_readl(l2x0_base + L2X0_AUX_CTRL);
+	__raw_writel(val, sar_base + L2X0_AUXCTRL_OFFSET);
+	val = __raw_readl(l2x0_base + L2X0_PREFETCH_CTRL);
+	__raw_writel(val, sar_base + L2X0_PREFETCH_CTRL_OFFSET);
+}
+#else
+static void save_l2x0_context(void)
+{}
+#endif
+
 /**
  * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
  * The purpose of this function is to manage low power programming
@@ -182,6 +215,7 @@ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
 	set_cpu_next_pwrst(cpu, power_state);
 	set_cpu_wakeup_addr(cpu, virt_to_phys(omap4_cpu_resume));
 	scu_pwrst_prepare(cpu, power_state);
+	l2x0_pwrst_prepare(cpu, save_state);
 
 	/*
 	 * Call low level function  with targeted low power state.
@@ -239,17 +273,19 @@ int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
 int __init omap4_mpuss_init(void)
 {
 	struct omap4_cpu_pm_info *pm_info;
-	void __iomem *sar_base = omap4_get_sar_ram_base();
 
 	if (omap_rev() == OMAP4430_REV_ES1_0) {
 		WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 		return -ENODEV;
 	}
 
+	sar_base = omap4_get_sar_ram_base();
+
 	/* Initilaise per CPU PM information */
 	pm_info = &per_cpu(omap4_pm_info, 0x0);
 	pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
 	pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
+	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
 	pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
 	if (!pm_info->pwrdm) {
 		pr_err("Lookup failed for CPU0 pwrdm\n");
@@ -265,6 +301,7 @@ int __init omap4_mpuss_init(void)
 	pm_info = &per_cpu(omap4_pm_info, 0x1);
 	pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
 	pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
+	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
 	pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
 	if (!pm_info->pwrdm) {
 		pr_err("Lookup failed for CPU1 pwrdm\n");
@@ -290,6 +327,8 @@ int __init omap4_mpuss_init(void)
 	else
 		__raw_writel(0, sar_base + OMAP_TYPE_OFFSET);
 
+	save_l2x0_context();
+
 	return 0;
 }