Initial commit; kernel source import

drivers/devfreq/Kconfig

@@ -0,0 +1,81 @@
+menuconfig PM_DEVFREQ
+	bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
+	help
+	  A device may have a list of frequencies and voltages available.
+	  devfreq, a generic DVFS framework can be registered for a device
+	  in order to let the governor provided to devfreq choose an
+	  operating frequency based on the device driver's policy.
+
+	  Each device may have its own governor and policy. Devfreq can
+	  reevaluate the device state periodically and/or based on the
+	  notification to "nb", a notifier block, of devfreq.
+
+	  Like some CPUs with CPUfreq, a device may have multiple clocks.
+	  However, because the clock frequencies of a single device are
+	  determined by the single device's state, an instance of devfreq
+	  is attached to a single device and returns a "representative"
+	  clock frequency of the device, which is also attached
+	  to a device by 1-to-1. The device registering devfreq takes the
+	  responsibility to "interpret" the representative frequency and
+	  to set its every clock accordingly with the "target" callback
+	  given to devfreq.
+
+	  When OPP is used with the devfreq device, it is recommended to
+	  register devfreq's nb to the OPP's notifier head.  If OPP is
+	  used with the devfreq device, you may use OPP helper
+	  functions defined in devfreq.h.
+
+if PM_DEVFREQ
+
+comment "DEVFREQ Governors"
+
+config DEVFREQ_GOV_SIMPLE_ONDEMAND
+	tristate "Simple Ondemand"
+	help
+	  Chooses frequency based on the recent load on the device. Works
+	  similar as ONDEMAND governor of CPUFREQ does. A device with
+	  Simple-Ondemand should be able to provide busy/total counter
+	  values that imply the usage rate. A device may provide tuned
+	  values to the governor with data field at devfreq_add_device().
+
+config DEVFREQ_GOV_PERFORMANCE
+	tristate "Performance"
+	help
+	  Sets the frequency at the maximum available frequency.
+	  This governor always returns UINT_MAX as frequency so that
+	  the DEVFREQ framework returns the highest frequency available
+	  at any time.
+
+config DEVFREQ_GOV_POWERSAVE
+	tristate "Powersave"
+	help
+	  Sets the frequency at the minimum available frequency.
+	  This governor always returns 0 as frequency so that
+	  the DEVFREQ framework returns the lowest frequency available
+	  at any time.
+
+config DEVFREQ_GOV_USERSPACE
+	tristate "Userspace"
+	help
+	  Sets the frequency at the user specified one.
+	  This governor returns the user configured frequency if there
+	  has been an input to /sys/devices/.../power/devfreq_set_freq.
+	  Otherwise, the governor does not change the frequnecy
+	  given at the initialization.
+
+comment "DEVFREQ Drivers"
+
+config ARM_EXYNOS4_BUS_DEVFREQ
+	bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
+	depends on CPU_EXYNOS4210 || CPU_EXYNOS4212 || CPU_EXYNOS4412
+	select ARCH_HAS_OPP
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	help
+	  This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
+	  and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
+	  It reads PPMU counters of memory controllers and adjusts
+	  the operating frequencies and voltages with OPP support.
+	  To operate with optimal voltages, ASV support is required
+	  (CONFIG_EXYNOS_ASV).
+
+endif # PM_DEVFREQ

drivers/devfreq/Makefile

@@ -0,0 +1,8 @@
+obj-$(CONFIG_PM_DEVFREQ)	+= devfreq.o
+obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)	+= governor_simpleondemand.o
+obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE)	+= governor_performance.o
+obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
+obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
+
+# DEVFREQ Drivers
+obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos4_bus.o

drivers/devfreq/governor.h

@@ -0,0 +1,41 @@
+/*
+ * governor.h - internal header for devfreq governors.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This header is for devfreq governors in drivers/devfreq/
+ */
+
+#ifndef _GOVERNOR_H
+#define _GOVERNOR_H
+
+#include <linux/devfreq.h>
+
+#define to_devfreq(DEV)	container_of((DEV), struct devfreq, dev)
+
+/* Devfreq events */
+#define DEVFREQ_GOV_START			0x1
+#define DEVFREQ_GOV_STOP			0x2
+#define DEVFREQ_GOV_INTERVAL			0x3
+#define DEVFREQ_GOV_SUSPEND			0x4
+#define DEVFREQ_GOV_RESUME			0x5
+
+/* Caution: devfreq->lock must be locked before calling update_devfreq */
+extern int update_devfreq(struct devfreq *devfreq);
+
+extern void devfreq_monitor_start(struct devfreq *devfreq);
+extern void devfreq_monitor_stop(struct devfreq *devfreq);
+extern void devfreq_monitor_suspend(struct devfreq *devfreq);
+extern void devfreq_monitor_resume(struct devfreq *devfreq);
+extern void devfreq_interval_update(struct devfreq *devfreq,
+					unsigned int *delay);
+
+extern int devfreq_add_governor(struct devfreq_governor *governor);
+extern int devfreq_remove_governor(struct devfreq_governor *governor);
+
+#endif /* _GOVERNOR_H */

drivers/devfreq/governor_performance.c

@@ -0,0 +1,67 @@
+/*
+ *  linux/drivers/devfreq/governor_performance.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/devfreq.h>
+#include <linux/module.h>
+#include "governor.h"
+
+static int devfreq_performance_func(struct devfreq *df,
+				    unsigned long *freq)
+{
+	/*
+	 * target callback should be able to get floor value as
+	 * said in devfreq.h
+	 */
+	if (!df->max_freq)
+		*freq = UINT_MAX;
+	else
+		*freq = df->max_freq;
+	return 0;
+}
+
+static int devfreq_performance_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	int ret = 0;
+
+	if (event == DEVFREQ_GOV_START) {
+		mutex_lock(&devfreq->lock);
+		ret = update_devfreq(devfreq);
+		mutex_unlock(&devfreq->lock);
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_performance = {
+	.name = "performance",
+	.get_target_freq = devfreq_performance_func,
+	.event_handler = devfreq_performance_handler,
+};
+
+static int __init devfreq_performance_init(void)
+{
+	return devfreq_add_governor(&devfreq_performance);
+}
+subsys_initcall(devfreq_performance_init);
+
+static void __exit devfreq_performance_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_performance);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_performance_exit);
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_powersave.c

@@ -0,0 +1,64 @@
+/*
+ *  linux/drivers/devfreq/governor_powersave.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/devfreq.h>
+#include <linux/module.h>
+#include "governor.h"
+
+static int devfreq_powersave_func(struct devfreq *df,
+				  unsigned long *freq)
+{
+	/*
+	 * target callback should be able to get ceiling value as
+	 * said in devfreq.h
+	 */
+	*freq = df->min_freq;
+	return 0;
+}
+
+static int devfreq_powersave_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	int ret = 0;
+
+	if (event == DEVFREQ_GOV_START) {
+		mutex_lock(&devfreq->lock);
+		ret = update_devfreq(devfreq);
+		mutex_unlock(&devfreq->lock);
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_powersave = {
+	.name = "powersave",
+	.get_target_freq = devfreq_powersave_func,
+	.event_handler = devfreq_powersave_handler,
+};
+
+static int __init devfreq_powersave_init(void)
+{
+	return devfreq_add_governor(&devfreq_powersave);
+}
+subsys_initcall(devfreq_powersave_init);
+
+static void __exit devfreq_powersave_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_powersave);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_powersave_exit);
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_simpleondemand.c

@@ -0,0 +1,147 @@
+/*
+ *  linux/drivers/devfreq/governor_simpleondemand.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/devfreq.h>
+#include <linux/math64.h>
+#include "governor.h"
+
+/* Default constants for DevFreq-Simple-Ondemand (DFSO) */
+#define DFSO_UPTHRESHOLD	(90)
+#define DFSO_DOWNDIFFERENCTIAL	(5)
+static int devfreq_simple_ondemand_func(struct devfreq *df,
+					unsigned long *freq)
+{
+	struct devfreq_dev_status stat;
+	int err = df->profile->get_dev_status(df->dev.parent, &stat);
+	unsigned long long a, b;
+	unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
+	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
+	struct devfreq_simple_ondemand_data *data = df->data;
+	unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX;
+
+	if (err)
+		return err;
+
+	if (data) {
+		if (data->upthreshold)
+			dfso_upthreshold = data->upthreshold;
+		if (data->downdifferential)
+			dfso_downdifferential = data->downdifferential;
+	}
+	if (dfso_upthreshold > 100 ||
+	    dfso_upthreshold < dfso_downdifferential)
+		return -EINVAL;
+
+	/* Assume MAX if it is going to be divided by zero */
+	if (stat.total_time == 0) {
+		*freq = max;
+		return 0;
+	}
+
+	/* Prevent overflow */
+	if (stat.busy_time >= (1 << 24) || stat.total_time >= (1 << 24)) {
+		stat.busy_time >>= 7;
+		stat.total_time >>= 7;
+	}
+
+	/* Set MAX if it's busy enough */
+	if (stat.busy_time * 100 >
+	    stat.total_time * dfso_upthreshold) {
+		*freq = max;
+		return 0;
+	}
+
+	/* Set MAX if we do not know the initial frequency */
+	if (stat.current_frequency == 0) {
+		*freq = max;
+		return 0;
+	}
+
+	/* Keep the current frequency */
+	if (stat.busy_time * 100 >
+	    stat.total_time * (dfso_upthreshold - dfso_downdifferential)) {
+		*freq = stat.current_frequency;
+		return 0;
+	}
+
+	/* Set the desired frequency based on the load */
+	a = stat.busy_time;
+	a *= stat.current_frequency;
+	b = div_u64(a, stat.total_time);
+	b *= 100;
+	b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));
+	*freq = (unsigned long) b;
+
+	if (df->min_freq && *freq < df->min_freq)
+		*freq = df->min_freq;
+	if (df->max_freq && *freq > df->max_freq)
+		*freq = df->max_freq;
+
+	return 0;
+}
+
+static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		devfreq_monitor_start(devfreq);
+		break;
+
+	case DEVFREQ_GOV_STOP:
+		devfreq_monitor_stop(devfreq);
+		break;
+
+	case DEVFREQ_GOV_INTERVAL:
+		devfreq_interval_update(devfreq, (unsigned int *)data);
+		break;
+
+	case DEVFREQ_GOV_SUSPEND:
+		devfreq_monitor_suspend(devfreq);
+		break;
+
+	case DEVFREQ_GOV_RESUME:
+		devfreq_monitor_resume(devfreq);
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct devfreq_governor devfreq_simple_ondemand = {
+	.name = "simple_ondemand",
+	.get_target_freq = devfreq_simple_ondemand_func,
+	.event_handler = devfreq_simple_ondemand_handler,
+};
+
+static int __init devfreq_simple_ondemand_init(void)
+{
+	return devfreq_add_governor(&devfreq_simple_ondemand);
+}
+subsys_initcall(devfreq_simple_ondemand_init);
+
+static void __exit devfreq_simple_ondemand_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_simple_ondemand);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_simple_ondemand_exit);
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_userspace.c

@@ -0,0 +1,162 @@
+/*
+ *  linux/drivers/devfreq/governor_simpleondemand.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/devfreq.h>
+#include <linux/pm.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include "governor.h"
+
+struct userspace_data {
+	unsigned long user_frequency;
+	bool valid;
+};
+
+static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)
+{
+	struct userspace_data *data = df->data;
+
+	if (data->valid) {
+		unsigned long adjusted_freq = data->user_frequency;
+
+		if (df->max_freq && adjusted_freq > df->max_freq)
+			adjusted_freq = df->max_freq;
+
+		if (df->min_freq && adjusted_freq < df->min_freq)
+			adjusted_freq = df->min_freq;
+
+		*freq = adjusted_freq;
+	} else {
+		*freq = df->previous_freq; /* No user freq specified yet */
+	}
+	return 0;
+}
+
+static ssize_t store_freq(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	struct userspace_data *data;
+	unsigned long wanted;
+	int err = 0;
+
+
+	mutex_lock(&devfreq->lock);
+	data = devfreq->data;
+
+	sscanf(buf, "%lu", &wanted);
+	data->user_frequency = wanted;
+	data->valid = true;
+	err = update_devfreq(devfreq);
+	if (err == 0)
+		err = count;
+	mutex_unlock(&devfreq->lock);
+	return err;
+}
+
+static ssize_t show_freq(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	struct userspace_data *data;
+	int err = 0;
+
+	mutex_lock(&devfreq->lock);
+	data = devfreq->data;
+
+	if (data->valid)
+		err = sprintf(buf, "%lu\n", data->user_frequency);
+	else
+		err = sprintf(buf, "undefined\n");
+	mutex_unlock(&devfreq->lock);
+	return err;
+}
+
+static DEVICE_ATTR(set_freq, 0644, show_freq, store_freq);
+static struct attribute *dev_entries[] = {
+	&dev_attr_set_freq.attr,
+	NULL,
+};
+static struct attribute_group dev_attr_group = {
+	.name	= "userspace",
+	.attrs	= dev_entries,
+};
+
+static int userspace_init(struct devfreq *devfreq)
+{
+	int err = 0;
+	struct userspace_data *data = kzalloc(sizeof(struct userspace_data),
+					      GFP_KERNEL);
+
+	if (!data) {
+		err = -ENOMEM;
+		goto out;
+	}
+	data->valid = false;
+	devfreq->data = data;
+
+	err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group);
+out:
+	return err;
+}
+
+static void userspace_exit(struct devfreq *devfreq)
+{
+	sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
+	kfree(devfreq->data);
+	devfreq->data = NULL;
+}
+
+static int devfreq_userspace_handler(struct devfreq *devfreq,
+			unsigned int event, void *data)
+{
+	int ret = 0;
+
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		ret = userspace_init(devfreq);
+		break;
+	case DEVFREQ_GOV_STOP:
+		userspace_exit(devfreq);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_userspace = {
+	.name = "userspace",
+	.get_target_freq = devfreq_userspace_func,
+	.event_handler = devfreq_userspace_handler,
+};
+
+static int __init devfreq_userspace_init(void)
+{
+	return devfreq_add_governor(&devfreq_userspace);
+}
+subsys_initcall(devfreq_userspace_init);
+
+static void __exit devfreq_userspace_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_userspace);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_userspace_exit);
+MODULE_LICENSE("GPL");