[V3,2/4] ARM: tegra: pmc: add power on function for secondary CPUs

Commit Message

Joseph Lo March 1, 2013, 7:32 a.m. UTC

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 <[e-mail]>
---
V3:
* making code more simpler in pmc_powergate_set and is_powered func
V2:
* Don't use ISS_ERR_VALUE for checking error return code
* the CPU power on function only available for secondary CPU which means
  we don't support (cpuid <= 0 || cpuid >= num_possible_cpus())
* adding a WARN_ON when the current power state is same with we want to set
---
 arch/arm/mach-tegra/pmc.c | 101 +++++++++++++++++++++++++++++++++++++++++++++-
 arch/arm/mach-tegra/pmc.h |   4 ++
 2 files changed, 103 insertions(+), 2 deletions(-)

Comments

Stephen Warren March 1, 2013, 7:29 p.m. UTC | #1

On 03/01/2013 12:32 AM, Joseph Lo wrote:
> 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.

OK, I think these look good. I'll apply them for 3.10 when I can.

Note: you reposted 2 out of 4 patches. It'd be best to repost all the
patches in the series. While I understand that the other 2 didn't
change, not reposting them makes it a bit harder to track down which
patches fit together into a series, since I have to find some "V2" and
some "V3" and stick them together. That said, given you've already
posted the patches, there's no need to repost them again to fix them
this time; just a note for next time.

Patch

diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c
index a916eca..b30e921 100644
--- a/arch/arm/mach-tegra/pmc.c
+++ b/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" },
diff --git a/arch/arm/mach-tegra/pmc.h b/arch/arm/mach-tegra/pmc.h
index 8995ee4..7d44710 100644
--- a/arch/arm/mach-tegra/pmc.h
+++ b/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