Merge branch 'pm-cpuidle'

* pm-cpuidle: (25 commits)
  cpuidle: Change struct menu_device field types
  cpuidle: Add a comment warning about possible overflow
  cpuidle: Fix variable domains in get_typical_interval()
  cpuidle: Fix menu_device->intervals type
  cpuidle: CodingStyle: Break up multiple assignments on single line
  cpuidle: Check called function parameter in get_typical_interval()
  cpuidle: Rearrange code and comments in get_typical_interval()
  cpuidle: Ignore interval prediction result when timer is shorter
  cpuidle-kirkwood.c: simplify use of devm_ioremap_resource()
  cpuidle: kirkwood: Make kirkwood_cpuidle_remove function static
  cpuidle: calxeda: Add missing __iomem annotation
  SH: cpuidle: Add missing parameter for cpuidle_register()
  ARM: ux500: cpuidle: Move ux500 cpuidle driver to drivers/cpuidle
  ARM: ux500: cpuidle: Remove pointless include
  ARM: ux500: cpuidle: Instantiate the driver from platform device
  ARM: davinci: cpuidle: Fix target residency
  cpuidle: Add Kconfig.arm and move calxeda, kirkwood and zynq
  cpuidle: Check if device is already registered
  cpuidle: Introduce __cpuidle_device_init()
  cpuidle: Introduce __cpuidle_unregister_device()
  ...

15 files changed, 256 insertions, 163 deletions

diff --git a/arch/arm/mach-davinci/cpuidle.c b/arch/arm/mach-davinci/cpuidle.c
index 36aef3a7dedb..f1ac1c94ac0f 100644
--- a/arch/arm/mach-davinci/cpuidle.c
+++ b/arch/arm/mach-davinci/cpuidle.c
@@ -65,7 +65,7 @@ static struct cpuidle_driver davinci_idle_driver = {
 	.states[1]		= {
 		.enter			= davinci_enter_idle,
 		.exit_latency		= 10,
-		.target_residency	= 100000,
+		.target_residency	= 10000,
 		.flags			= CPUIDLE_FLAG_TIME_VALID,
 		.name			= "DDR SR",
 		.desc			= "WFI and DDR Self Refresh",
diff --git a/arch/arm/mach-ux500/Makefile b/arch/arm/mach-ux500/Makefile
index bf9b6be5b180..fe1f3e26b88b 100644
--- a/arch/arm/mach-ux500/Makefile
+++ b/arch/arm/mach-ux500/Makefile
@@ -4,7 +4,6 @@
 
 obj-y				:= cpu.o devices.o devices-common.o \
 				   id.o usb.o timer.o pm.o
-obj-$(CONFIG_CPU_IDLE)          += cpuidle.o
 obj-$(CONFIG_CACHE_L2X0)	+= cache-l2x0.o
 obj-$(CONFIG_UX500_SOC_DB8500)	+= cpu-db8500.o devices-db8500.o
 obj-$(CONFIG_MACH_MOP500)	+= board-mop500.o board-mop500-sdi.o \
diff --git a/arch/sh/kernel/cpu/shmobile/cpuidle.c b/arch/sh/kernel/cpu/shmobile/cpuidle.c
index d30622592116..e3abfd4277e2 100644
--- a/arch/sh/kernel/cpu/shmobile/cpuidle.c
+++ b/arch/sh/kernel/cpu/shmobile/cpuidle.c
@@ -91,13 +91,11 @@ static struct cpuidle_driver cpuidle_driver = {
 
 int __init sh_mobile_setup_cpuidle(void)
 {
-	int ret;
-
 	if (sh_mobile_sleep_supported & SUSP_SH_SF)
 		cpuidle_driver.states[1].disabled = false;
 
 	if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
 		cpuidle_driver.states[2].disabled = false;
 
-	return cpuidle_register(&cpuidle_driver);
+	return cpuidle_register(&cpuidle_driver, NULL);
 }
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index 0e2cd5cab4d0..b3fb81d7cf04 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -1,5 +1,6 @@
+menu "CPU Idle"
 
-menuconfig CPU_IDLE
+config CPU_IDLE
 	bool "CPU idle PM support"
 	default y if ACPI || PPC_PSERIES
 	select CPU_IDLE_GOV_LADDER if (!NO_HZ && !NO_HZ_IDLE)
@@ -29,20 +30,13 @@ config CPU_IDLE_GOV_MENU
 	bool "Menu governor (for tickless system)"
 	default y
 
-config CPU_IDLE_CALXEDA
-	bool "CPU Idle Driver for Calxeda processors"
-	depends on ARCH_HIGHBANK
-	select ARM_CPU_SUSPEND
-	help
-	  Select this to enable cpuidle on Calxeda processors.
-
-config CPU_IDLE_ZYNQ
-	bool "CPU Idle Driver for Xilinx Zynq processors"
-	depends on ARCH_ZYNQ
-	help
-	  Select this to enable cpuidle on Xilinx Zynq processors.
+menu "ARM CPU Idle Drivers"
+depends on ARM
+source "drivers/cpuidle/Kconfig.arm"
+endmenu
 
 endif
 
 config ARCH_NEEDS_CPU_IDLE_COUPLED
 	def_bool n
+endmenu
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
new file mode 100644
index 000000000000..b3302193c15a
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.arm
@@ -0,0 +1,29 @@
+#
+# ARM CPU Idle drivers
+#
+
+config ARM_HIGHBANK_CPUIDLE
+	bool "CPU Idle Driver for Calxeda processors"
+	depends on ARCH_HIGHBANK
+	select ARM_CPU_SUSPEND
+	help
+	  Select this to enable cpuidle on Calxeda processors.
+
+config ARM_KIRKWOOD_CPUIDLE
+	bool "CPU Idle Driver for Marvell Kirkwood SoCs"
+	depends on ARCH_KIRKWOOD
+	help
+	  This adds the CPU Idle driver for Marvell Kirkwood SoCs.
+
+config ARM_ZYNQ_CPUIDLE
+	bool "CPU Idle Driver for Xilinx Zynq processors"
+	depends on ARCH_ZYNQ
+	help
+	  Select this to enable cpuidle on Xilinx Zynq processors.
+
+config ARM_U8500_CPUIDLE
+	bool "Cpu Idle Driver for the ST-E u8500 processors"
+	depends on ARCH_U8500
+	help
+	  Select this to enable cpuidle for ST-E u8500 processors
+
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 8767a7b3eb91..0b9d200c7e45 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -5,6 +5,9 @@
 obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
 obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
 
-obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o
-obj-$(CONFIG_ARCH_KIRKWOOD) += cpuidle-kirkwood.o
-obj-$(CONFIG_CPU_IDLE_ZYNQ) += cpuidle-zynq.o
+##################################################################################
+# ARM SoC drivers
+obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE)	+= cpuidle-calxeda.o
+obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o
+obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
+obj-$(CONFIG_ARM_U8500_CPUIDLE)         += cpuidle-ux500.o
diff --git a/drivers/cpuidle/cpuidle-calxeda.c b/drivers/cpuidle/cpuidle-calxeda.c
index 0e6e408c0a63..346058479572 100644
--- a/drivers/cpuidle/cpuidle-calxeda.c
+++ b/drivers/cpuidle/cpuidle-calxeda.c
@@ -35,7 +35,7 @@
 #include <asm/cp15.h>
 
 extern void highbank_set_cpu_jump(int cpu, void *jump_addr);
-extern void *scu_base_addr;
+extern void __iomem *scu_base_addr;
 
 static noinline void calxeda_idle_restore(void)
 {
diff --git a/drivers/cpuidle/cpuidle-kirkwood.c b/drivers/cpuidle/cpuidle-kirkwood.c
index 521b0a7fdd89..41ba843251b8 100644
--- a/drivers/cpuidle/cpuidle-kirkwood.c
+++ b/drivers/cpuidle/cpuidle-kirkwood.c
@@ -60,9 +60,6 @@ static int kirkwood_cpuidle_probe(struct platform_device *pdev)
 	struct resource *res;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (res == NULL)
-		return -EINVAL;
-
 	ddr_operation_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(ddr_operation_base))
 		return PTR_ERR(ddr_operation_base);
@@ -70,7 +67,7 @@ static int kirkwood_cpuidle_probe(struct platform_device *pdev)
 	return cpuidle_register(&kirkwood_idle_driver, NULL);
 }
 
-int kirkwood_cpuidle_remove(struct platform_device *pdev)
+static int kirkwood_cpuidle_remove(struct platform_device *pdev)
 {
 	cpuidle_unregister(&kirkwood_idle_driver);
 	return 0;
diff --git a/arch/arm/mach-ux500/cpuidle.c b/drivers/cpuidle/cpuidle-ux500.c
index a45dd09daed9..e0564652af35 100644
--- a/arch/arm/mach-ux500/cpuidle.c
+++ b/drivers/cpuidle/cpuidle-ux500.c
@@ -16,13 +16,11 @@
 #include <linux/smp.h>
 #include <linux/mfd/dbx500-prcmu.h>
 #include <linux/platform_data/arm-ux500-pm.h>
+#include <linux/platform_device.h>
 
 #include <asm/cpuidle.h>
 #include <asm/proc-fns.h>
 
-#include "db8500-regs.h"
-#include "id.h"
-
 static atomic_t master = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(master_lock);
 
@@ -113,11 +111,8 @@ static struct cpuidle_driver ux500_idle_driver = {
 	.state_count = 2,
 };
 
-int __init ux500_idle_init(void)
+static int __init dbx500_cpuidle_probe(struct platform_device *pdev)
 {
-	if (!(cpu_is_u8500_family() || cpu_is_ux540_family()))
-		return -ENODEV;
-
 	/* Configure wake up reasons */
 	prcmu_enable_wakeups(PRCMU_WAKEUP(ARM) | PRCMU_WAKEUP(RTC) |
 			     PRCMU_WAKEUP(ABB));
@@ -125,4 +120,12 @@ int __init ux500_idle_init(void)
 	return cpuidle_register(&ux500_idle_driver, NULL);
 }
 
-device_initcall(ux500_idle_init);
+static struct platform_driver dbx500_cpuidle_plat_driver = {
+	.driver = {
+		.name = "cpuidle-dbx500",
+		.owner = THIS_MODULE,
+	},
+	.probe = dbx500_cpuidle_probe,
+};
+
+module_platform_driver(dbx500_cpuidle_plat_driver);
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index fdc432f18022..d75040ddd2b3 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -42,8 +42,6 @@ void disable_cpuidle(void)
 	off = 1;
 }
 
-static int __cpuidle_register_device(struct cpuidle_device *dev);
-
 /**
  * cpuidle_play_dead - cpu off-lining
  *
@@ -278,7 +276,7 @@ static void poll_idle_init(struct cpuidle_driver *drv) {}
  */
 int cpuidle_enable_device(struct cpuidle_device *dev)
 {
-	int ret, i;
+	int ret;
 	struct cpuidle_driver *drv;
 
 	if (!dev)
@@ -292,15 +290,12 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
 	if (!drv || !cpuidle_curr_governor)
 		return -EIO;
 
+	if (!dev->registered)
+		return -EINVAL;
+
 	if (!dev->state_count)
 		dev->state_count = drv->state_count;
 
-	if (dev->registered == 0) {
-		ret = __cpuidle_register_device(dev);
-		if (ret)
-			return ret;
-	}
-
 	poll_idle_init(drv);
 
 	ret = cpuidle_add_device_sysfs(dev);
@@ -311,12 +306,6 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
 	    (ret = cpuidle_curr_governor->enable(drv, dev)))
 		goto fail_sysfs;
 
-	for (i = 0; i < dev->state_count; i++) {
-		dev->states_usage[i].usage = 0;
-		dev->states_usage[i].time = 0;
-	}
-	dev->last_residency = 0;
-
 	smp_wmb();
 
 	dev->enabled = 1;
@@ -360,6 +349,23 @@ void cpuidle_disable_device(struct cpuidle_device *dev)
 
 EXPORT_SYMBOL_GPL(cpuidle_disable_device);
 
+static void __cpuidle_unregister_device(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+
+	list_del(&dev->device_list);
+	per_cpu(cpuidle_devices, dev->cpu) = NULL;
+	module_put(drv->owner);
+}
+
+static int __cpuidle_device_init(struct cpuidle_device *dev)
+{
+	memset(dev->states_usage, 0, sizeof(dev->states_usage));
+	dev->last_residency = 0;
+
+	return 0;
+}
+
 /**
  * __cpuidle_register_device - internal register function called before register
  * and enable routines
@@ -377,24 +383,15 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
 
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
-	ret = cpuidle_add_sysfs(dev);
-	if (ret)
-		goto err_sysfs;
 
 	ret = cpuidle_coupled_register_device(dev);
-	if (ret)
-		goto err_coupled;
+	if (ret) {
+		__cpuidle_unregister_device(dev);
+		return ret;
+	}
 
 	dev->registered = 1;
 	return 0;
-
-err_coupled:
-	cpuidle_remove_sysfs(dev);
-err_sysfs:
-	list_del(&dev->device_list);
-	per_cpu(cpuidle_devices, dev->cpu) = NULL;
-	module_put(drv->owner);
-	return ret;
 }
 
 /**
@@ -403,25 +400,44 @@ err_sysfs:
  */
 int cpuidle_register_device(struct cpuidle_device *dev)
 {
-	int ret;
+	int ret = -EBUSY;
 
 	if (!dev)
 		return -EINVAL;
 
 	mutex_lock(&cpuidle_lock);
 
-	if ((ret = __cpuidle_register_device(dev))) {
-		mutex_unlock(&cpuidle_lock);
-		return ret;
-	}
+	if (dev->registered)
+		goto out_unlock;
+
+	ret = __cpuidle_device_init(dev);
+	if (ret)
+		goto out_unlock;
+
+	ret = __cpuidle_register_device(dev);
+	if (ret)
+		goto out_unlock;
+
+	ret = cpuidle_add_sysfs(dev);
+	if (ret)
+		goto out_unregister;
+
+	ret = cpuidle_enable_device(dev);
+	if (ret)
+		goto out_sysfs;
 
-	cpuidle_enable_device(dev);
 	cpuidle_install_idle_handler();
 
+out_unlock:
 	mutex_unlock(&cpuidle_lock);
 
-	return 0;
+	return ret;
 
+out_sysfs:
+	cpuidle_remove_sysfs(dev);
+out_unregister:
+	__cpuidle_unregister_device(dev);
+	goto out_unlock;
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_register_device);
@@ -432,8 +448,6 @@ EXPORT_SYMBOL_GPL(cpuidle_register_device);
  */
 void cpuidle_unregister_device(struct cpuidle_device *dev)
 {
-	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
-
 	if (dev->registered == 0)
 		return;
 
@@ -442,14 +456,12 @@ void cpuidle_unregister_device(struct cpuidle_device *dev)
 	cpuidle_disable_device(dev);
 
 	cpuidle_remove_sysfs(dev);
-	list_del(&dev->device_list);
-	per_cpu(cpuidle_devices, dev->cpu) = NULL;
+
+	__cpuidle_unregister_device(dev);
 
 	cpuidle_coupled_unregister_device(dev);
 
 	cpuidle_resume_and_unlock();
-
-	module_put(drv->owner);
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_unregister_device);
diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c
index 9b784051ec12..9f08e8cce1af 100644
--- a/drivers/cpuidle/governors/ladder.c
+++ b/drivers/cpuidle/governors/ladder.c
@@ -192,14 +192,4 @@ static int __init init_ladder(void)
 	return cpuidle_register_governor(&ladder_governor);
 }
 
-/**
- * exit_ladder - exits the governor
- */
-static void __exit exit_ladder(void)
-{
-	cpuidle_unregister_governor(&ladder_governor);
-}
-
-MODULE_LICENSE("GPL");
-module_init(init_ladder);
-module_exit(exit_ladder);
+postcore_initcall(init_ladder);
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index bc580b67a652..cf7f2f0e4ef5 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -21,6 +21,15 @@
 #include <linux/math64.h>
 #include <linux/module.h>
 
+/*
+ * Please note when changing the tuning values:
+ * If (MAX_INTERESTING-1) * RESOLUTION > UINT_MAX, the result of
+ * a scaling operation multiplication may overflow on 32 bit platforms.
+ * In that case, #define RESOLUTION as ULL to get 64 bit result:
+ * #define RESOLUTION 1024ULL
+ *
+ * The default values do not overflow.
+ */
 #define BUCKETS 12
 #define INTERVALS 8
 #define RESOLUTION 1024
@@ -114,11 +123,11 @@ struct menu_device {
 	int             needs_update;
 
 	unsigned int	expected_us;
-	u64		predicted_us;
+	unsigned int	predicted_us;
 	unsigned int	exit_us;
 	unsigned int	bucket;
-	u64		correction_factor[BUCKETS];
-	u32		intervals[INTERVALS];
+	unsigned int	correction_factor[BUCKETS];
+	unsigned int	intervals[INTERVALS];
 	int		interval_ptr;
 };
 
@@ -199,16 +208,20 @@ static u64 div_round64(u64 dividend, u32 divisor)
  */
 static void get_typical_interval(struct menu_device *data)
 {
-	int i = 0, divisor = 0;
-	uint64_t max = 0, avg = 0, stddev = 0;
-	int64_t thresh = LLONG_MAX; /* Discard outliers above this value. */
+	int i, divisor;
+	unsigned int max, thresh;
+	uint64_t avg, stddev;
+
+	thresh = UINT_MAX; /* Discard outliers above this value */
 
 again:
 
-	/* first calculate average and standard deviation of the past */
-	max = avg = divisor = stddev = 0;
+	/* First calculate the average of past intervals */
+	max = 0;
+	avg = 0;
+	divisor = 0;
 	for (i = 0; i < INTERVALS; i++) {
-		int64_t value = data->intervals[i];
+		unsigned int value = data->intervals[i];
 		if (value <= thresh) {
 			avg += value;
 			divisor++;
@@ -218,15 +231,38 @@ again:
 	}
 	do_div(avg, divisor);
 
+	/* Then try to determine standard deviation */
+	stddev = 0;
 	for (i = 0; i < INTERVALS; i++) {
-		int64_t value = data->intervals[i];
+		unsigned int value = data->intervals[i];
 		if (value <= thresh) {
 			int64_t diff = value - avg;
 			stddev += diff * diff;
 		}
 	}
 	do_div(stddev, divisor);
-	stddev = int_sqrt(stddev);
+	/*
+	 * The typical interval is obtained when standard deviation is small
+	 * or standard deviation is small compared to the average interval.
+	 *
+	 * int_sqrt() formal parameter type is unsigned long. When the
+	 * greatest difference to an outlier exceeds ~65 ms * sqrt(divisor)
+	 * the resulting squared standard deviation exceeds the input domain
+	 * of int_sqrt on platforms where unsigned long is 32 bits in size.
+	 * In such case reject the candidate average.
+	 *
+	 * Use this result only if there is no timer to wake us up sooner.
+	 */
+	if (likely(stddev <= ULONG_MAX)) {
+		stddev = int_sqrt(stddev);
+		if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
+							|| stddev <= 20) {
+			if (data->expected_us > avg)
+				data->predicted_us = avg;
+			return;
+		}
+	}
+
 	/*
 	 * If we have outliers to the upside in our distribution, discard
 	 * those by setting the threshold to exclude these outliers, then
@@ -235,20 +271,12 @@ again:
 	 *
 	 * This can deal with workloads that have long pauses interspersed
 	 * with sporadic activity with a bunch of short pauses.
-	 *
-	 * The typical interval is obtained when standard deviation is small
-	 * or standard deviation is small compared to the average interval.
 	 */
-	if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
-							|| stddev <= 20) {
-		data->predicted_us = avg;
+	if ((divisor * 4) <= INTERVALS * 3)
 		return;
 
-	} else if ((divisor * 4) > INTERVALS * 3) {
-		/* Exclude the max interval */
-		thresh = max - 1;
-		goto again;
-	}
+	thresh = max - 1;
+	goto again;
 }
 
 /**
@@ -293,8 +321,13 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	if (data->correction_factor[data->bucket] == 0)
 		data->correction_factor[data->bucket] = RESOLUTION * DECAY;
 
-	/* Make sure to round up for half microseconds */
-	data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
+	/*
+	 * Force the result of multiplication to be 64 bits even if both
+	 * operands are 32 bits.
+	 * Make sure to round up for half microseconds.
+	 */
+	data->predicted_us = div_round64((uint64_t)data->expected_us *
+					 data->correction_factor[data->bucket],
 					 RESOLUTION * DECAY);
 
 	get_typical_interval(data);
@@ -360,7 +393,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	unsigned int last_idle_us = cpuidle_get_last_residency(dev);
 	struct cpuidle_state *target = &drv->states[last_idx];
 	unsigned int measured_us;
-	u64 new_factor;
+	unsigned int new_factor;
 
 	/*
 	 * Ugh, this idle state doesn't support residency measurements, so we
@@ -381,10 +414,9 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		measured_us -= data->exit_us;
 
 
-	/* update our correction ratio */
-
-	new_factor = data->correction_factor[data->bucket]
-			* (DECAY - 1) / DECAY;
+	/* Update our correction ratio */
+	new_factor = data->correction_factor[data->bucket];
+	new_factor -= new_factor / DECAY;
 
 	if (data->expected_us > 0 && measured_us < MAX_INTERESTING)
 		new_factor += RESOLUTION * measured_us / data->expected_us;
@@ -397,9 +429,11 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 
 	/*
 	 * We don't want 0 as factor; we always want at least
-	 * a tiny bit of estimated time.
+	 * a tiny bit of estimated time. Fortunately, due to rounding,
+	 * new_factor will stay nonzero regardless of measured_us values
+	 * and the compiler can eliminate this test as long as DECAY > 1.
 	 */
-	if (new_factor == 0)
+	if (DECAY == 1 && unlikely(new_factor == 0))
 		new_factor = 1;
 
 	data->correction_factor[data->bucket] = new_factor;
@@ -442,14 +476,4 @@ static int __init init_menu(void)
 	return cpuidle_register_governor(&menu_governor);
 }
 
-/**
- * exit_menu - exits the governor
- */
-static void __exit exit_menu(void)
-{
-	cpuidle_unregister_governor(&menu_governor);
-}
-
-MODULE_LICENSE("GPL");
-module_init(init_menu);
-module_exit(exit_menu);
+postcore_initcall(init_menu);
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 428754af6236..8739cc05228c 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -11,8 +11,10 @@
 #include <linux/sysfs.h>
 #include <linux/slab.h>
 #include <linux/cpu.h>
+#include <linux/completion.h>
 #include <linux/capability.h>
 #include <linux/device.h>
+#include <linux/kobject.h>
 
 #include "cpuidle.h"
 
@@ -33,7 +35,8 @@ static ssize_t show_available_governors(struct device *dev,
 
 	mutex_lock(&cpuidle_lock);
 	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
-		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
+		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
+				    CPUIDLE_NAME_LEN - 2))
 			goto out;
 		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
 	}
@@ -166,13 +169,28 @@ struct cpuidle_attr {
 #define define_one_rw(_name, show, store) \
 	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 
-#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
-static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
+
+struct cpuidle_device_kobj {
+	struct cpuidle_device *dev;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
+static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
+{
+	struct cpuidle_device_kobj *kdev =
+		container_of(kobj, struct cpuidle_device_kobj, kobj);
+
+	return kdev->dev;
+}
+
+static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
+			    char *buf)
 {
 	int ret = -EIO;
-	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
-	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
+	struct cpuidle_device *dev = to_cpuidle_device(kobj);
+	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 
 	if (cattr->show) {
 		mutex_lock(&cpuidle_lock);
@@ -182,12 +200,12 @@ static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char
 	return ret;
 }
 
-static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
-		     const char * buf, size_t count)
+static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
+			     const char *buf, size_t count)
 {
 	int ret = -EIO;
-	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
-	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
+	struct cpuidle_device *dev = to_cpuidle_device(kobj);
+	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 
 	if (cattr->store) {
 		mutex_lock(&cpuidle_lock);
@@ -204,9 +222,10 @@ static const struct sysfs_ops cpuidle_sysfs_ops = {
 
 static void cpuidle_sysfs_release(struct kobject *kobj)
 {
-	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+	struct cpuidle_device_kobj *kdev =
+		container_of(kobj, struct cpuidle_device_kobj, kobj);
 
-	complete(&dev->kobj_unregister);
+	complete(&kdev->kobj_unregister);
 }
 
 static struct kobj_type ktype_cpuidle = {
@@ -237,8 +256,8 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, \
 
 #define define_store_state_ull_function(_name) \
 static ssize_t store_state_##_name(struct cpuidle_state *state, \
-		struct cpuidle_state_usage *state_usage, \
-		const char *buf, size_t size) \
+				   struct cpuidle_state_usage *state_usage, \
+				   const char *buf, size_t size)	\
 { \
 	unsigned long long value; \
 	int err; \
@@ -256,14 +275,16 @@ static ssize_t store_state_##_name(struct cpuidle_state *state, \
 
 #define define_show_state_ull_function(_name) \
 static ssize_t show_state_##_name(struct cpuidle_state *state, \
-			struct cpuidle_state_usage *state_usage, char *buf) \
+				  struct cpuidle_state_usage *state_usage, \
+				  char *buf)				\
 { \
 	return sprintf(buf, "%llu\n", state_usage->_name);\
 }
 
 #define define_show_state_str_function(_name) \
 static ssize_t show_state_##_name(struct cpuidle_state *state, \
-			struct cpuidle_state_usage *state_usage, char *buf) \
+				  struct cpuidle_state_usage *state_usage, \
+				  char *buf)				\
 { \
 	if (state->_name[0] == '\0')\
 		return sprintf(buf, "<null>\n");\
@@ -309,8 +330,9 @@ struct cpuidle_state_kobj {
 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
-static ssize_t cpuidle_state_show(struct kobject * kobj,
-	struct attribute * attr ,char * buf)
+
+static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
+				  char * buf)
 {
 	int ret = -EIO;
 	struct cpuidle_state *state = kobj_to_state(kobj);
@@ -323,8 +345,8 @@ static ssize_t cpuidle_state_show(struct kobject * kobj,
 	return ret;
 }
 
-static ssize_t cpuidle_state_store(struct kobject *kobj,
-	struct attribute *attr, const char *buf, size_t size)
+static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
+				   const char *buf, size_t size)
 {
 	int ret = -EIO;
 	struct cpuidle_state *state = kobj_to_state(kobj);
@@ -371,6 +393,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 {
 	int i, ret = -ENOMEM;
 	struct cpuidle_state_kobj *kobj;
+	struct cpuidle_device_kobj *kdev = device->kobj_dev;
 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 
 	/* state statistics */
@@ -383,7 +406,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 		init_completion(&kobj->kobj_unregister);
 
 		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
-					   &device->kobj, "state%d", i);
+					   &kdev->kobj, "state%d", i);
 		if (ret) {
 			kfree(kobj);
 			goto error_state;
@@ -449,8 +472,8 @@ static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 	complete(&driver_kobj->kobj_unregister);
 }
 
-static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute * attr,
-				   char * buf)
+static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
+				   char *buf)
 {
 	int ret = -EIO;
 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
@@ -500,6 +523,7 @@ static struct kobj_type ktype_driver_cpuidle = {
 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 {
 	struct cpuidle_driver_kobj *kdrv;
+	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 	int ret;
 
@@ -511,7 +535,7 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 	init_completion(&kdrv->kobj_unregister);
 
 	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
-				   &dev->kobj, "driver");
+				   &kdev->kobj, "driver");
 	if (ret) {
 		kfree(kdrv);
 		return ret;
@@ -580,16 +604,28 @@ void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
  */
 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 {
+	struct cpuidle_device_kobj *kdev;
 	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 	int error;
 
-	init_completion(&dev->kobj_unregister);
+	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
+	if (!kdev)
+		return -ENOMEM;
+	kdev->dev = dev;
+	dev->kobj_dev = kdev;
 
-	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
-				     "cpuidle");
-	if (!error)
-		kobject_uevent(&dev->kobj, KOBJ_ADD);
-	return error;
+	init_completion(&kdev->kobj_unregister);
+
+	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
+				   "cpuidle");
+	if (error) {
+		kfree(kdev);
+		return error;
+	}
+
+	kobject_uevent(&kdev->kobj, KOBJ_ADD);
+
+	return 0;
 }
 
 /**
@@ -598,6 +634,9 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
  */
 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 {
-	kobject_put(&dev->kobj);
-	wait_for_completion(&dev->kobj_unregister);
+	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
+
+	kobject_put(&kdev->kobj);
+	wait_for_completion(&kdev->kobj_unregister);
+	kfree(kdev);
 }
diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index 3c157faee645..0d68eb1a5ec5 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -3094,6 +3094,10 @@ static struct mfd_cell db8500_prcmu_devs[] = {
 		.pdata_size = sizeof(db8500_cpufreq_table),
 	},
 	{
+		.name = "cpuidle-dbx500",
+		.of_compatible = "stericsson,cpuidle-dbx500",
+	},
+	{
 		.name = "db8500-thermal",
 		.num_resources = ARRAY_SIZE(db8500_thsens_resources),
 		.resources = db8500_thsens_resources,
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 0bc4b74668e9..781addc66f03 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -13,8 +13,6 @@
 
 #include <linux/percpu.h>
 #include <linux/list.h>
-#include <linux/kobject.h>
-#include <linux/completion.h>
 #include <linux/hrtimer.h>
 
 #define CPUIDLE_STATE_MAX	10
@@ -61,6 +59,10 @@ struct cpuidle_state {
 
 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
 
+struct cpuidle_device_kobj;
+struct cpuidle_state_kobj;
+struct cpuidle_driver_kobj;
+
 struct cpuidle_device {
 	unsigned int		registered:1;
 	unsigned int		enabled:1;
@@ -71,9 +73,8 @@ struct cpuidle_device {
 	struct cpuidle_state_usage	states_usage[CPUIDLE_STATE_MAX];
 	struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
 	struct cpuidle_driver_kobj *kobj_driver;
+	struct cpuidle_device_kobj *kobj_dev;
 	struct list_head 	device_list;
-	struct kobject		kobj;
-	struct completion	kobj_unregister;
 
 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 	int			safe_state_index;