[PATCH] ARM: EXYNOS4: Add support Core1 Power On/Off with hotplug in/out

JungHi Min junghi.min at samsung.com
Fri Jul 1 00:29:15 EDT 2011


To insert the code for power on/off with pmu control to support hotplug in/out core1
As for hotplug.c, the codes for core1 to be hotplug in/out is inserted.
As for regs-pmu.h, S5P_CORE_LOCAL_PWR_EN is defined.
As for platsmp.c, the codes for core1 to be powered on is inserted.

Signed-off-by: JungHi Min <junghi.min at samsung.com>
---
 arch/arm/mach-exynos4/hotplug.c               |   13 ++++++----
 arch/arm/mach-exynos4/include/mach/regs-pmu.h |    1 +
 arch/arm/mach-exynos4/platsmp.c               |   33 +++++++++++++++++++++++-
 3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-exynos4/hotplug.c b/arch/arm/mach-exynos4/hotplug.c
index 2b5909e..7490789 100644
--- a/arch/arm/mach-exynos4/hotplug.c
+++ b/arch/arm/mach-exynos4/hotplug.c
@@ -13,9 +13,12 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
+#include <linux/io.h>
 
 #include <asm/cacheflush.h>
 
+#include <mach/regs-pmu.h>
+
 extern volatile int pen_release;
 
 static inline void cpu_enter_lowpower(void)
@@ -58,12 +61,12 @@ static inline void cpu_leave_lowpower(void)
 
 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
 {
-	/*
-	 * there is no power-control hardware on this platform, so all
-	 * we can do is put the core into WFI; this is safe as the calling
-	 * code will have already disabled interrupts
-	 */
 	for (;;) {
+
+		/* make cpu1 to be turned off at next WFI command */
+		if (cpu == 1)
+			__raw_writel(0, S5P_ARM_CORE1_CONFIGURATION);
+
 		/*
 		 * here's the WFI
 		 */
diff --git a/arch/arm/mach-exynos4/include/mach/regs-pmu.h b/arch/arm/mach-exynos4/include/mach/regs-pmu.h
index a964337..96de0e7 100644
--- a/arch/arm/mach-exynos4/include/mach/regs-pmu.h
+++ b/arch/arm/mach-exynos4/include/mach/regs-pmu.h
@@ -158,6 +158,7 @@
 #define S5P_PMU_GPS_CONF			S5P_PMUREG(0x3CE0)
 
 #define S5P_PMU_SATA_PHY_CONTROL_EN		0x1
+#define S5P_CORE_LOCAL_PWR_EN			0x3
 #define S5P_INT_LOCAL_PWR_EN			0x7

 define S5P_CHECK_SLEEP				0x00000BAD
diff --git a/arch/arm/mach-exynos4/platsmp.c b/arch/arm/mach-exynos4/platsmp.c
index c5e65a0..15aa2c0 100644
--- a/arch/arm/mach-exynos4/platsmp.c
+++ b/arch/arm/mach-exynos4/platsmp.c
@@ -28,9 +28,12 @@
 
 #include <mach/hardware.h>
 #include <mach/regs-clock.h>
+#include <mach/regs-pmu.h>
 
 extern void exynos4_secondary_startup(void);
 
+#define CPU1_BOOT_REG S5P_VA_SYSRAM
+
 /*
  * control for which core is the next to come out of the secondary
  * boot "holding pen"
@@ -100,16 +103,41 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
 	 */
 	write_pen_release(cpu);
 
+	if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN)) {
+		__raw_writel(S5P_CORE_LOCAL_PWR_EN,
+			     S5P_ARM_CORE1_CONFIGURATION);
+
+		timeout = 10;
+
+		/* wait max 10 ms until cpu1 is on */
+		while ((__raw_readl(S5P_ARM_CORE1_STATUS)
+			& S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN) {
+			if (timeout-- == 0)
+				break;
+
+			mdelay(1);
+		}
+
+		if (timeout == 0) {
+			printk(KERN_ERR "cpu1 power enable failed");
+			spin_unlock(&boot_lock);
+			return -ETIMEDOUT;
+		}
+	}
 	/*
 	 * Send the secondary CPU a soft interrupt, thereby causing
 	 * the boot monitor to read the system wide flags register,
 	 * and branch to the address found there.
 	 */
-	gic_raise_softirq(cpumask_of(cpu), 1);
 
 	timeout = jiffies + (1 * HZ);
 	while (time_before(jiffies, timeout)) {
 		smp_rmb();
+
+		__raw_writel(BSYM(virt_to_phys(exynos4_secondary_startup)),
+			CPU1_BOOT_REG);
+		gic_raise_softirq(cpumask_of(cpu), 1);
+
 		if (pen_release == -1)
 			break;
 
-- 
1.7.1




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