[RFC PATCH 1/8] ARM: Add commonly used cpuidle init code

[Robert Lee]

Add commonly used cpuidle init code to avoid unecessary duplication.

Signed-off-by: Robert Lee <rob.lee at linaro.org>
---
 arch/arm/common/Makefile       |    1 +
 arch/arm/common/cpuidle.c      |  132 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/include/asm/cpuidle.h |   25 ++++++++
 3 files changed, 158 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/common/cpuidle.c
 create mode 100644 arch/arm/include/asm/cpuidle.h

diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 6ea9b6f..0865f69 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_ARCH_IXP2000)	+= uengine.o
 obj-$(CONFIG_ARCH_IXP23XX)	+= uengine.o
 obj-$(CONFIG_PCI_HOST_ITE8152)  += it8152.o
 obj-$(CONFIG_ARM_TIMER_SP804)	+= timer-sp.o
+obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o
diff --git a/arch/arm/common/cpuidle.c b/arch/arm/common/cpuidle.c
new file mode 100644
index 0000000..e9a46a3
--- /dev/null
+++ b/arch/arm/common/cpuidle.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/*
+ * This code performs provides some commonly used cpuidle setup functionality
+ * used by many ARM SoC platforms.  Providing this functionality here
+ * reduces the duplication of this code for each ARM platform that uses it.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/cpuidle.h>
+#include <linux/hrtimer.h>
+#include <linux/err.h>
+#include <asm/cpuidle.h>
+#include <asm/proc-fns.h>
+
+static struct cpuidle_device __percpu * arm_cpuidle_devices;
+
+static int (*mach_cpuidle)(struct cpuidle_device *dev,
+			       struct cpuidle_driver *drv,
+				int index);
+
+static int arm_enter_idle(struct cpuidle_device *dev,
+			       struct cpuidle_driver *drv, int index)
+{
+	ktime_t time_start, time_end;
+
+	local_irq_disable();
+	local_fiq_disable();
+
+	time_start = ktime_get();
+
+	index = mach_cpuidle(dev, drv, index);
+
+	time_end = ktime_get();
+
+	local_fiq_enable();
+	local_irq_enable();
+
+	dev->last_residency =
+		(int)ktime_to_us(ktime_sub(time_end, time_start));
+
+	return index;
+}
+
+void arm_cpuidle_devices_uninit(void)
+{
+	int cpu_id;
+	struct cpuidle_device *dev;
+
+	for_each_possible_cpu(cpu_id) {
+		dev = per_cpu_ptr(arm_cpuidle_devices, cpu_id);
+		cpuidle_unregister_device(dev);
+	}
+
+	free_percpu(arm_cpuidle_devices);
+	return;
+}
+
+int __init arm_cpuidle_init(struct cpuidle_driver *drv,
+	int (*common_enter)(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int index),
+	void *driver_data[])
+{
+	struct cpuidle_device *dev;
+	int i, cpu_id;
+
+	if (drv == NULL) {
+		pr_err("%s: cpuidle_driver pointer NULL\n", __func__);
+		return -EINVAL;
+	}
+
+	if (drv->state_count > CPUIDLE_STATE_MAX)
+		pr_err("%s: state count exceeds maximum\n", __func__);
+
+	mach_cpuidle = common_enter;
+
+	/* if state enter function not specified, use common_enter function */
+	for (i = 0; i < drv->state_count; i++) {
+		if (drv->states[i].enter == NULL) {
+			if (mach_cpuidle == NULL) {
+				pr_err("%s: 'enter' function pointer NULL\n",
+				__func__);
+				return -EINVAL;
+			} else
+				drv->states[i].enter = arm_enter_idle;
+		}
+	}
+
+	if (cpuidle_register_driver(drv)) {
+		pr_err("%s: Failed to register cpuidle driver\n", __func__);
+		return -ENODEV;
+	}
+
+	arm_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+	if (arm_cpuidle_devices == NULL) {
+		cpuidle_unregister_driver(drv);
+		return -ENOMEM;
+	}
+
+	/* initialize state data for each cpuidle_device */
+	for_each_possible_cpu(cpu_id) {
+
+		dev = per_cpu_ptr(arm_cpuidle_devices, cpu_id);
+		dev->cpu = cpu_id;
+		dev->state_count = drv->state_count;
+
+		if (driver_data)
+			for (i = 0; i < dev->state_count; i++) {
+				dev->states_usage[i].driver_data =
+							driver_data[i];
+			}
+
+		if (cpuidle_register_device(dev)) {
+			pr_err("%s: Failed to register cpu %u\n",
+				__func__, cpu_id);
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h
new file mode 100644
index 0000000..86faa74
--- /dev/null
+++ b/arch/arm/include/asm/cpuidle.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#ifndef __ARCH_ARM_ASM_CPUIDLE_H__
+#define __ARCH_ARM_ASM_CPUIDLE_H__
+
+#include <linux/cpuidle.h>
+
+extern int arm_cpuidle_init(struct cpuidle_driver *drv,
+	int (*common_enter)(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int index),
+	void *driver_data[]);
+
+extern void arm_cpuidle_devices_uninit(void);
+
+#endif /* __ARCH_ARM_ASM_CPUIDLE_H__ */
-- 
1.7.1