ARM: tegra: pmc: add power on function for secondary CPUs

Adding the power on function for secondary CPUs in PMC driver, this can
help us to remove legacy powergate driver and add generic power domain
support later.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

arch/arm/mach-tegra/pmc.c

@@ -20,8 +20,26 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 
-#define PMC_CTRL		0x0
-#define PMC_CTRL_INTR_LOW	(1 << 17)
+#define PMC_CTRL			0x0
+#define PMC_CTRL_INTR_LOW		(1 << 17)
+#define PMC_PWRGATE_TOGGLE		0x30
+#define PMC_PWRGATE_TOGGLE_START	(1 << 8)
+#define PMC_REMOVE_CLAMPING		0x34
+#define PMC_PWRGATE_STATUS		0x38
+
+#define TEGRA_POWERGATE_PCIE	3
+#define TEGRA_POWERGATE_VDEC	4
+#define TEGRA_POWERGATE_CPU1	9
+#define TEGRA_POWERGATE_CPU2	10
+#define TEGRA_POWERGATE_CPU3	11
+
+static u8 tegra_cpu_domains[] = {
+	0xFF,			/* not available for CPU0 */
+	TEGRA_POWERGATE_CPU1,
+	TEGRA_POWERGATE_CPU2,
+	TEGRA_POWERGATE_CPU3,
+};
+static DEFINE_SPINLOCK(tegra_powergate_lock);
 
 static void __iomem *tegra_pmc_base;
 static bool tegra_pmc_invert_interrupt;
@@ -36,6 +54,85 @@ static inline void tegra_pmc_writel(u32 val, u32 reg)
 	writel(val, tegra_pmc_base + reg);
 }
 
+static int tegra_pmc_get_cpu_powerdomain_id(int cpuid)
+{
+	if (cpuid <= 0 || cpuid >= num_possible_cpus())
+		return -EINVAL;
+	return tegra_cpu_domains[cpuid];
+}
+
+static bool tegra_pmc_powergate_is_powered(int id)
+{
+	return (tegra_pmc_readl(PMC_PWRGATE_STATUS) >> id) & 1;
+}
+
+static int tegra_pmc_powergate_set(int id, bool new_state)
+{
+	bool old_state;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tegra_powergate_lock, flags);
+
+	old_state = tegra_pmc_powergate_is_powered(id);
+	WARN_ON(old_state == new_state);
+
+	tegra_pmc_writel(PMC_PWRGATE_TOGGLE_START | id, PMC_PWRGATE_TOGGLE);
+
+	spin_unlock_irqrestore(&tegra_powergate_lock, flags);
+
+	return 0;
+}
+
+static int tegra_pmc_powergate_remove_clamping(int id)
+{
+	u32 mask;
+
+	/*
+	 * Tegra has a bug where PCIE and VDE clamping masks are
+	 * swapped relatively to the partition ids.
+	 */
+	if (id ==  TEGRA_POWERGATE_VDEC)
+		mask = (1 << TEGRA_POWERGATE_PCIE);
+	else if	(id == TEGRA_POWERGATE_PCIE)
+		mask = (1 << TEGRA_POWERGATE_VDEC);
+	else
+		mask = (1 << id);
+
+	tegra_pmc_writel(mask, PMC_REMOVE_CLAMPING);
+
+	return 0;
+}
+
+bool tegra_pmc_cpu_is_powered(int cpuid)
+{
+	int id;
+
+	id = tegra_pmc_get_cpu_powerdomain_id(cpuid);
+	if (id < 0)
+		return false;
+	return tegra_pmc_powergate_is_powered(id);
+}
+
+int tegra_pmc_cpu_power_on(int cpuid)
+{
+	int id;
+
+	id = tegra_pmc_get_cpu_powerdomain_id(cpuid);
+	if (id < 0)
+		return id;
+	return tegra_pmc_powergate_set(id, true);
+}
+
+int tegra_pmc_cpu_remove_clamping(int cpuid)
+{
+	int id;
+
+	id = tegra_pmc_get_cpu_powerdomain_id(cpuid);
+	if (id < 0)
+		return id;
+	return tegra_pmc_powergate_remove_clamping(id);
+}
+
 static const struct of_device_id matches[] __initconst = {
 	{ .compatible = "nvidia,tegra114-pmc" },
 	{ .compatible = "nvidia,tegra30-pmc" },

arch/arm/mach-tegra/pmc.h

@@ -18,6 +18,10 @@
 #ifndef __MACH_TEGRA_PMC_H
 #define __MACH_TEGRA_PMC_H
 
+bool tegra_pmc_cpu_is_powered(int cpuid);
+int tegra_pmc_cpu_power_on(int cpuid);
+int tegra_pmc_cpu_remove_clamping(int cpuid);
+
 void tegra_pmc_init(void);
 
 #endif