ARM: tegra: pm: add platform suspend support

Adding suspend to RAM support for Tegra platform. There are three suspend
mode for Tegra. The difference were below.

* LP2: CPU voltage off
* LP1: CPU voltage off, DRAM in self-refresh
* LP0: CPU + Core voltage off, DRAM in self-refresh

After this patch, the LP2 suspend mode will be supported.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 80 insertions, 13 deletions

diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index 5f5611f40b43..3a3318a83ad3 100644
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -22,6 +22,7 @@
 #include <linux/cpumask.h>
 #include <linux/delay.h>
 #include <linux/cpu_pm.h>
+#include <linux/suspend.h>
 #include <linux/err.h>
 #include <linux/clk/tegra.h>
 
@@ -38,14 +39,10 @@
 #include "fuse.h"
 #include "pmc.h"
 #include "sleep.h"
-
-#define TEGRA_POWER_CPU_PWRREQ_OE	(1 << 16)  /* CPU pwr req enable */
-
-#define PMC_CTRL		0x0
+#include "pmc.h"
 
 #ifdef CONFIG_PM_SLEEP
 static DEFINE_SPINLOCK(tegra_lp2_lock);
-static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);
 void (*tegra_tear_down_cpu)(void);
 
 /*
@@ -145,14 +142,7 @@ static int tegra_sleep_cpu(unsigned long v2p)
 
 void tegra_idle_lp2_last(u32 cpu_on_time, u32 cpu_off_time)
 {
-	u32 mode;
-
-	/* Only the last cpu down does the final suspend steps */
-	mode = readl(pmc + PMC_CTRL);
-	mode |= TEGRA_POWER_CPU_PWRREQ_OE;
-	writel(mode, pmc + PMC_CTRL);
-
-	set_power_timers(cpu_on_time, cpu_off_time);
+	tegra_pmc_pm_set(TEGRA_SUSPEND_LP2);
 
 	cpu_cluster_pm_enter();
 	suspend_cpu_complex();
@@ -162,4 +152,81 @@ void tegra_idle_lp2_last(u32 cpu_on_time, u32 cpu_off_time)
 	restore_cpu_complex();
 	cpu_cluster_pm_exit();
 }
+
+enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
+				enum tegra_suspend_mode mode)
+{
+	/* Tegra114 didn't support any suspending mode yet. */
+	if (tegra_chip_id == TEGRA114)
+		return TEGRA_SUSPEND_NONE;
+
+	/*
+	 * The Tegra devices only support suspending to LP2 currently.
+	 */
+	if (mode > TEGRA_SUSPEND_LP2)
+		return TEGRA_SUSPEND_LP2;
+
+	return mode;
+}
+
+static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
+	[TEGRA_SUSPEND_NONE] = "none",
+	[TEGRA_SUSPEND_LP2] = "LP2",
+	[TEGRA_SUSPEND_LP1] = "LP1",
+	[TEGRA_SUSPEND_LP0] = "LP0",
+};
+
+static int __cpuinit tegra_suspend_enter(suspend_state_t state)
+{
+	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
+
+	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
+		    mode >= TEGRA_MAX_SUSPEND_MODE))
+		return -EINVAL;
+
+	pr_info("Entering suspend state %s\n", lp_state[mode]);
+
+	tegra_pmc_pm_set(mode);
+
+	local_fiq_disable();
+
+	suspend_cpu_complex();
+	switch (mode) {
+	case TEGRA_SUSPEND_LP2:
+		tegra_set_cpu_in_lp2(0);
+		break;
+	default:
+		break;
+	}
+
+	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
+
+	switch (mode) {
+	case TEGRA_SUSPEND_LP2:
+		tegra_clear_cpu_in_lp2(0);
+		break;
+	default:
+		break;
+	}
+	restore_cpu_complex();
+
+	local_fiq_enable();
+
+	return 0;
+}
+
+static const struct platform_suspend_ops tegra_suspend_ops = {
+	.valid		= suspend_valid_only_mem,
+	.enter		= tegra_suspend_enter,
+};
+
+void __init tegra_init_suspend(void)
+{
+	if (tegra_pmc_get_suspend_mode() == TEGRA_SUSPEND_NONE)
+		return;
+
+	tegra_pmc_suspend_init();
+
+	suspend_set_ops(&tegra_suspend_ops);
+}
 #endif