regulator: regulator framework core

This adds the regulator framework core.

This framework is designed to provide a generic interface to voltage
and current regulators within the Linux kernel. It's intended to
provide voltage and current control to client or consumer drivers and
also provide status information to user space applications through a
sysfs interface.

The intention is to allow systems to dynamically control regulator
output in order to save power and prolong battery life. This applies
to both voltage regulators (where voltage output is controllable) and
current sinks (where current output is controllable).

This framework safely compiles out if not selected so that client
drivers can still be used in systems with no software controllable
regulators.

Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 1903 insertions, 0 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
new file mode 100644
index 000000000000..9c7986261568
--- /dev/null
+++ b/drivers/regulator/core.c
@@ -0,0 +1,1903 @@
+/*
+ * core.c  --  Voltage/Current Regulator framework.
+ *
+ * Copyright 2007, 2008 Wolfson Microelectronics PLC.
+ *
+ * Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/suspend.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+
+#define REGULATOR_VERSION "0.5"
+
+static DEFINE_MUTEX(regulator_list_mutex);
+static LIST_HEAD(regulator_list);
+static LIST_HEAD(regulator_map_list);
+
+/**
+ * struct regulator_dev
+ *
+ * Voltage / Current regulator class device. One for each regulator.
+ */
+struct regulator_dev {
+	struct regulator_desc *desc;
+	int use_count;
+
+	/* lists we belong to */
+	struct list_head list; /* list of all regulators */
+	struct list_head slist; /* list of supplied regulators */
+
+	/* lists we own */
+	struct list_head consumer_list; /* consumers we supply */
+	struct list_head supply_list; /* regulators we supply */
+
+	struct blocking_notifier_head notifier;
+	struct mutex mutex; /* consumer lock */
+	struct module *owner;
+	struct device dev;
+	struct regulation_constraints *constraints;
+	struct regulator_dev *supply;	/* for tree */
+
+	void *reg_data;		/* regulator_dev data */
+};
+
+/**
+ * struct regulator_map
+ *
+ * Used to provide symbolic supply names to devices.
+ */
+struct regulator_map {
+	struct list_head list;
+	struct device *dev;
+	const char *supply;
+	const char *regulator;
+};
+
+static inline struct regulator_dev *to_rdev(struct device *d)
+{
+	return container_of(d, struct regulator_dev, dev);
+}
+
+/*
+ * struct regulator
+ *
+ * One for each consumer device.
+ */
+struct regulator {
+	struct device *dev;
+	struct list_head list;
+	int uA_load;
+	int min_uV;
+	int max_uV;
+	int enabled; /* client has called enabled */
+	char *supply_name;
+	struct device_attribute dev_attr;
+	struct regulator_dev *rdev;
+};
+
+static int _regulator_is_enabled(struct regulator_dev *rdev);
+static int _regulator_disable(struct regulator_dev *rdev);
+static int _regulator_get_voltage(struct regulator_dev *rdev);
+static int _regulator_get_current_limit(struct regulator_dev *rdev);
+static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
+static void _notifier_call_chain(struct regulator_dev *rdev,
+				  unsigned long event, void *data);
+
+/* gets the regulator for a given consumer device */
+static struct regulator *get_device_regulator(struct device *dev)
+{
+	struct regulator *regulator = NULL;
+	struct regulator_dev *rdev;
+
+	mutex_lock(&regulator_list_mutex);
+	list_for_each_entry(rdev, &regulator_list, list) {
+		mutex_lock(&rdev->mutex);
+		list_for_each_entry(regulator, &rdev->consumer_list, list) {
+			if (regulator->dev == dev) {
+				mutex_unlock(&rdev->mutex);
+				mutex_unlock(&regulator_list_mutex);
+				return regulator;
+			}
+		}
+		mutex_unlock(&rdev->mutex);
+	}
+	mutex_unlock(&regulator_list_mutex);
+	return NULL;
+}
+
+/* Platform voltage constraint check */
+static int regulator_check_voltage(struct regulator_dev *rdev,
+				   int *min_uV, int *max_uV)
+{
+	BUG_ON(*min_uV > *max_uV);
+
+	if (!rdev->constraints) {
+		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+		       rdev->desc->name);
+		return -ENODEV;
+	}
+	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE)) {
+		printk(KERN_ERR "%s: operation not allowed for %s\n",
+		       __func__, rdev->desc->name);
+		return -EPERM;
+	}
+
+	if (*max_uV > rdev->constraints->max_uV)
+		*max_uV = rdev->constraints->max_uV;
+	if (*min_uV < rdev->constraints->min_uV)
+		*min_uV = rdev->constraints->min_uV;
+
+	if (*min_uV > *max_uV)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* current constraint check */
+static int regulator_check_current_limit(struct regulator_dev *rdev,
+					int *min_uA, int *max_uA)
+{
+	BUG_ON(*min_uA > *max_uA);
+
+	if (!rdev->constraints) {
+		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+		       rdev->desc->name);
+		return -ENODEV;
+	}
+	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CURRENT)) {
+		printk(KERN_ERR "%s: operation not allowed for %s\n",
+		       __func__, rdev->desc->name);
+		return -EPERM;
+	}
+
+	if (*max_uA > rdev->constraints->max_uA)
+		*max_uA = rdev->constraints->max_uA;
+	if (*min_uA < rdev->constraints->min_uA)
+		*min_uA = rdev->constraints->min_uA;
+
+	if (*min_uA > *max_uA)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* operating mode constraint check */
+static int regulator_check_mode(struct regulator_dev *rdev, int mode)
+{
+	if (!rdev->constraints) {
+		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+		       rdev->desc->name);
+		return -ENODEV;
+	}
+	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE)) {
+		printk(KERN_ERR "%s: operation not allowed for %s\n",
+		       __func__, rdev->desc->name);
+		return -EPERM;
+	}
+	if (!(rdev->constraints->valid_modes_mask & mode)) {
+		printk(KERN_ERR "%s: invalid mode %x for %s\n",
+		       __func__, mode, rdev->desc->name);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/* dynamic regulator mode switching constraint check */
+static int regulator_check_drms(struct regulator_dev *rdev)
+{
+	if (!rdev->constraints) {
+		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+		       rdev->desc->name);
+		return -ENODEV;
+	}
+	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS)) {
+		printk(KERN_ERR "%s: operation not allowed for %s\n",
+		       __func__, rdev->desc->name);
+		return -EPERM;
+	}
+	return 0;
+}
+
+static ssize_t device_requested_uA_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct regulator *regulator;
+
+	regulator = get_device_regulator(dev);
+	if (regulator == NULL)
+		return 0;
+
+	return sprintf(buf, "%d\n", regulator->uA_load);
+}
+
+static ssize_t regulator_uV_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+	ssize_t ret;
+
+	mutex_lock(&rdev->mutex);
+	ret = sprintf(buf, "%d\n", _regulator_get_voltage(rdev));
+	mutex_unlock(&rdev->mutex);
+
+	return ret;
+}
+
+static ssize_t regulator_uA_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	return sprintf(buf, "%d\n", _regulator_get_current_limit(rdev));
+}
+
+static ssize_t regulator_opmode_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+	int mode = _regulator_get_mode(rdev);
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		return sprintf(buf, "fast\n");
+	case REGULATOR_MODE_NORMAL:
+		return sprintf(buf, "normal\n");
+	case REGULATOR_MODE_IDLE:
+		return sprintf(buf, "idle\n");
+	case REGULATOR_MODE_STANDBY:
+		return sprintf(buf, "standby\n");
+	}
+	return sprintf(buf, "unknown\n");
+}
+
+static ssize_t regulator_state_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+	int state = _regulator_is_enabled(rdev);
+
+	if (state > 0)
+		return sprintf(buf, "enabled\n");
+	else if (state == 0)
+		return sprintf(buf, "disabled\n");
+	else
+		return sprintf(buf, "unknown\n");
+}
+
+static ssize_t regulator_min_uA_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "constraint not defined\n");
+
+	return sprintf(buf, "%d\n", rdev->constraints->min_uA);
+}
+
+static ssize_t regulator_max_uA_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "constraint not defined\n");
+
+	return sprintf(buf, "%d\n", rdev->constraints->max_uA);
+}
+
+static ssize_t regulator_min_uV_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "constraint not defined\n");
+
+	return sprintf(buf, "%d\n", rdev->constraints->min_uV);
+}
+
+static ssize_t regulator_max_uV_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "constraint not defined\n");
+
+	return sprintf(buf, "%d\n", rdev->constraints->max_uV);
+}
+
+static ssize_t regulator_total_uA_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+	struct regulator *regulator;
+	int uA = 0;
+
+	mutex_lock(&rdev->mutex);
+	list_for_each_entry(regulator, &rdev->consumer_list, list)
+	    uA += regulator->uA_load;
+	mutex_unlock(&rdev->mutex);
+	return sprintf(buf, "%d\n", uA);
+}
+
+static ssize_t regulator_num_users_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+	return sprintf(buf, "%d\n", rdev->use_count);
+}
+
+static ssize_t regulator_type_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	switch (rdev->desc->type) {
+	case REGULATOR_VOLTAGE:
+		return sprintf(buf, "voltage\n");
+	case REGULATOR_CURRENT:
+		return sprintf(buf, "current\n");
+	}
+	return sprintf(buf, "unknown\n");
+}
+
+static ssize_t regulator_suspend_mem_uV_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+	return sprintf(buf, "%d\n", rdev->constraints->state_mem.uV);
+}
+
+static ssize_t regulator_suspend_disk_uV_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+	return sprintf(buf, "%d\n", rdev->constraints->state_disk.uV);
+}
+
+static ssize_t regulator_suspend_standby_uV_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+	return sprintf(buf, "%d\n", rdev->constraints->state_standby.uV);
+}
+
+static ssize_t suspend_opmode_show(struct regulator_dev *rdev,
+	unsigned int mode, char *buf)
+{
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		return sprintf(buf, "fast\n");
+	case REGULATOR_MODE_NORMAL:
+		return sprintf(buf, "normal\n");
+	case REGULATOR_MODE_IDLE:
+		return sprintf(buf, "idle\n");
+	case REGULATOR_MODE_STANDBY:
+		return sprintf(buf, "standby\n");
+	}
+	return sprintf(buf, "unknown\n");
+}
+
+static ssize_t regulator_suspend_mem_mode_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+	return suspend_opmode_show(rdev,
+		rdev->constraints->state_mem.mode, buf);
+}
+
+static ssize_t regulator_suspend_disk_mode_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+	return suspend_opmode_show(rdev,
+		rdev->constraints->state_disk.mode, buf);
+}
+
+static ssize_t regulator_suspend_standby_mode_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+	return suspend_opmode_show(rdev,
+		rdev->constraints->state_standby.mode, buf);
+}
+
+static ssize_t regulator_suspend_mem_state_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+
+	if (rdev->constraints->state_mem.enabled)
+		return sprintf(buf, "enabled\n");
+	else
+		return sprintf(buf, "disabled\n");
+}
+
+static ssize_t regulator_suspend_disk_state_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+
+	if (rdev->constraints->state_disk.enabled)
+		return sprintf(buf, "enabled\n");
+	else
+		return sprintf(buf, "disabled\n");
+}
+
+static ssize_t regulator_suspend_standby_state_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+
+	if (!rdev->constraints)
+		return sprintf(buf, "not defined\n");
+
+	if (rdev->constraints->state_standby.enabled)
+		return sprintf(buf, "enabled\n");
+	else
+		return sprintf(buf, "disabled\n");
+}
+static struct device_attribute regulator_dev_attrs[] = {
+	__ATTR(microvolts, 0444, regulator_uV_show, NULL),
+	__ATTR(microamps, 0444, regulator_uA_show, NULL),
+	__ATTR(opmode, 0444, regulator_opmode_show, NULL),
+	__ATTR(state, 0444, regulator_state_show, NULL),
+	__ATTR(min_microvolts, 0444, regulator_min_uV_show, NULL),
+	__ATTR(min_microamps, 0444, regulator_min_uA_show, NULL),
+	__ATTR(max_microvolts, 0444, regulator_max_uV_show, NULL),
+	__ATTR(max_microamps, 0444, regulator_max_uA_show, NULL),
+	__ATTR(requested_microamps, 0444, regulator_total_uA_show, NULL),
+	__ATTR(num_users, 0444, regulator_num_users_show, NULL),
+	__ATTR(type, 0444, regulator_type_show, NULL),
+	__ATTR(suspend_mem_microvolts, 0444,
+		regulator_suspend_mem_uV_show, NULL),
+	__ATTR(suspend_disk_microvolts, 0444,
+		regulator_suspend_disk_uV_show, NULL),
+	__ATTR(suspend_standby_microvolts, 0444,
+		regulator_suspend_standby_uV_show, NULL),
+	__ATTR(suspend_mem_mode, 0444,
+		regulator_suspend_mem_mode_show, NULL),
+	__ATTR(suspend_disk_mode, 0444,
+		regulator_suspend_disk_mode_show, NULL),
+	__ATTR(suspend_standby_mode, 0444,
+		regulator_suspend_standby_mode_show, NULL),
+	__ATTR(suspend_mem_state, 0444,
+		regulator_suspend_mem_state_show, NULL),
+	__ATTR(suspend_disk_state, 0444,
+		regulator_suspend_disk_state_show, NULL),
+	__ATTR(suspend_standby_state, 0444,
+		regulator_suspend_standby_state_show, NULL),
+	__ATTR_NULL,
+};
+
+static void regulator_dev_release(struct device *dev)
+{
+	struct regulator_dev *rdev = to_rdev(dev);
+	kfree(rdev);
+}
+
+static struct class regulator_class = {
+	.name = "regulator",
+	.dev_release = regulator_dev_release,
+	.dev_attrs = regulator_dev_attrs,
+};
+
+/* Calculate the new optimum regulator operating mode based on the new total
+ * consumer load. All locks held by caller */
+static void drms_uA_update(struct regulator_dev *rdev)
+{
+	struct regulator *sibling;
+	int current_uA = 0, output_uV, input_uV, err;
+	unsigned int mode;
+
+	err = regulator_check_drms(rdev);
+	if (err < 0 || !rdev->desc->ops->get_optimum_mode ||
+	    !rdev->desc->ops->get_voltage || !rdev->desc->ops->set_mode);
+	return;
+
+	/* get output voltage */
+	output_uV = rdev->desc->ops->get_voltage(rdev);
+	if (output_uV <= 0)
+		return;
+
+	/* get input voltage */
+	if (rdev->supply && rdev->supply->desc->ops->get_voltage)
+		input_uV = rdev->supply->desc->ops->get_voltage(rdev->supply);
+	else
+		input_uV = rdev->constraints->input_uV;
+	if (input_uV <= 0)
+		return;
+
+	/* calc total requested load */
+	list_for_each_entry(sibling, &rdev->consumer_list, list)
+	    current_uA += sibling->uA_load;
+
+	/* now get the optimum mode for our new total regulator load */
+	mode = rdev->desc->ops->get_optimum_mode(rdev, input_uV,
+						  output_uV, current_uA);
+
+	/* check the new mode is allowed */
+	err = regulator_check_mode(rdev, mode);
+	if (err == 0)
+		rdev->desc->ops->set_mode(rdev, mode);
+}
+
+static int suspend_set_state(struct regulator_dev *rdev,
+	struct regulator_state *rstate)
+{
+	int ret = 0;
+
+	/* enable & disable are mandatory for suspend control */
+	if (!rdev->desc->ops->set_suspend_enable ||
+		!rdev->desc->ops->set_suspend_disable)
+		return -EINVAL;
+
+	if (rstate->enabled)
+		ret = rdev->desc->ops->set_suspend_enable(rdev);
+	else
+		ret = rdev->desc->ops->set_suspend_disable(rdev);
+	if (ret < 0) {
+		printk(KERN_ERR "%s: failed to enabled/disable\n", __func__);
+		return ret;
+	}
+
+	if (rdev->desc->ops->set_suspend_voltage && rstate->uV > 0) {
+		ret = rdev->desc->ops->set_suspend_voltage(rdev, rstate->uV);
+		if (ret < 0) {
+			printk(KERN_ERR "%s: failed to set voltage\n",
+				__func__);
+			return ret;
+		}
+	}
+
+	if (rdev->desc->ops->set_suspend_mode && rstate->mode > 0) {
+		ret = rdev->desc->ops->set_suspend_mode(rdev, rstate->mode);
+		if (ret < 0) {
+			printk(KERN_ERR "%s: failed to set mode\n", __func__);
+			return ret;
+		}
+	}
+	return ret;
+}
+
+/* locks held by caller */
+static int suspend_prepare(struct regulator_dev *rdev, suspend_state_t state)
+{
+	if (!rdev->constraints)
+		return -EINVAL;
+
+	switch (state) {
+	case PM_SUSPEND_STANDBY:
+		return suspend_set_state(rdev,
+			&rdev->constraints->state_standby);
+	case PM_SUSPEND_MEM:
+		return suspend_set_state(rdev,
+			&rdev->constraints->state_mem);
+	case PM_SUSPEND_MAX:
+		return suspend_set_state(rdev,
+			&rdev->constraints->state_disk);
+	default:
+		return -EINVAL;
+	}
+}
+
+static void print_constraints(struct regulator_dev *rdev)
+{
+	struct regulation_constraints *constraints = rdev->constraints;
+	char buf[80];
+	int count;
+
+	if (rdev->desc->type == REGULATOR_VOLTAGE) {
+		if (constraints->min_uV == constraints->max_uV)
+			count = sprintf(buf, "%d mV ",
+					constraints->min_uV / 1000);
+		else
+			count = sprintf(buf, "%d <--> %d mV ",
+					constraints->min_uV / 1000,
+					constraints->max_uV / 1000);
+	} else {
+		if (constraints->min_uA == constraints->max_uA)
+			count = sprintf(buf, "%d mA ",
+					constraints->min_uA / 1000);
+		else
+			count = sprintf(buf, "%d <--> %d mA ",
+					constraints->min_uA / 1000,
+					constraints->max_uA / 1000);
+	}
+	if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
+		count += sprintf(buf + count, "fast ");
+	if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
+		count += sprintf(buf + count, "normal ");
+	if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
+		count += sprintf(buf + count, "idle ");
+	if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
+		count += sprintf(buf + count, "standby");
+
+	printk(KERN_INFO "regulator: %s: %s\n", rdev->desc->name, buf);
+}
+
+#define REG_STR_SIZE	32
+
+static struct regulator *create_regulator(struct regulator_dev *rdev,
+					  struct device *dev,
+					  const char *supply_name)
+{
+	struct regulator *regulator;
+	char buf[REG_STR_SIZE];
+	int err, size;
+
+	regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
+	if (regulator == NULL)
+		return NULL;
+
+	mutex_lock(&rdev->mutex);
+	regulator->rdev = rdev;
+	list_add(&regulator->list, &rdev->consumer_list);
+
+	if (dev) {
+		/* create a 'requested_microamps_name' sysfs entry */
+		size = scnprintf(buf, REG_STR_SIZE, "microamps_requested_%s",
+			supply_name);
+		if (size >= REG_STR_SIZE)
+			goto overflow_err;
+
+		regulator->dev = dev;
+		regulator->dev_attr.attr.name = kstrdup(buf, GFP_KERNEL);
+		if (regulator->dev_attr.attr.name == NULL)
+			goto attr_name_err;
+
+		regulator->dev_attr.attr.owner = THIS_MODULE;
+		regulator->dev_attr.attr.mode = 0444;
+		regulator->dev_attr.show = device_requested_uA_show;
+		err = device_create_file(dev, &regulator->dev_attr);
+		if (err < 0) {
+			printk(KERN_WARNING "%s: could not add regulator_dev"
+				" load sysfs\n", __func__);
+			goto attr_name_err;
+		}
+
+		/* also add a link to the device sysfs entry */
+		size = scnprintf(buf, REG_STR_SIZE, "%s-%s",
+				 dev->kobj.name, supply_name);
+		if (size >= REG_STR_SIZE)
+			goto attr_err;
+
+		regulator->supply_name = kstrdup(buf, GFP_KERNEL);
+		if (regulator->supply_name == NULL)
+			goto attr_err;
+
+		err = sysfs_create_link(&rdev->dev.kobj, &dev->kobj,
+					buf);
+		if (err) {
+			printk(KERN_WARNING
+			       "%s: could not add device link %s err %d\n",
+			       __func__, dev->kobj.name, err);
+			device_remove_file(dev, &regulator->dev_attr);
+			goto link_name_err;
+		}
+	}
+	mutex_unlock(&rdev->mutex);
+	return regulator;
+link_name_err:
+	kfree(regulator->supply_name);
+attr_err:
+	device_remove_file(regulator->dev, &regulator->dev_attr);
+attr_name_err:
+	kfree(regulator->dev_attr.attr.name);
+overflow_err:
+	list_del(&regulator->list);
+	kfree(regulator);
+	mutex_unlock(&rdev->mutex);
+	return NULL;
+}
+
+/**
+ * regulator_get - lookup and obtain a reference to a regulator.
+ * @dev: device for regulator "consumer"
+ * @id: Supply name or regulator ID.
+ *
+ * Returns a struct regulator corresponding to the regulator producer,
+ * or IS_ERR() condition containing errno.  Use of supply names
+ * configured via regulator_set_device_supply() is strongly
+ * encouraged.
+ */
+struct regulator *regulator_get(struct device *dev, const char *id)
+{
+	struct regulator_dev *rdev;
+	struct regulator_map *map;
+	struct regulator *regulator = ERR_PTR(-ENODEV);
+	const char *supply = id;
+
+	if (id == NULL) {
+		printk(KERN_ERR "regulator: get() with no identifier\n");
+		return regulator;
+	}
+
+	mutex_lock(&regulator_list_mutex);
+
+	list_for_each_entry(map, &regulator_map_list, list) {
+		if (dev == map->dev &&
+		    strcmp(map->supply, id) == 0) {
+			supply = map->regulator;
+			break;
+		}
+	}
+
+	list_for_each_entry(rdev, &regulator_list, list) {
+		if (strcmp(supply, rdev->desc->name) == 0 &&
+		    try_module_get(rdev->owner))
+			goto found;
+	}
+	printk(KERN_ERR "regulator: Unable to get requested regulator: %s\n",
+	       id);
+	mutex_unlock(&regulator_list_mutex);
+	return regulator;
+
+found:
+	regulator = create_regulator(rdev, dev, id);
+	if (regulator == NULL) {
+		regulator = ERR_PTR(-ENOMEM);
+		module_put(rdev->owner);
+	}
+
+	mutex_unlock(&regulator_list_mutex);
+	return regulator;
+}
+EXPORT_SYMBOL_GPL(regulator_get);
+
+/**
+ * regulator_put - "free" the regulator source
+ * @regulator: regulator source
+ *
+ * Note: drivers must ensure that all regulator_enable calls made on this
+ * regulator source are balanced by regulator_disable calls prior to calling
+ * this function.
+ */
+void regulator_put(struct regulator *regulator)
+{
+	struct regulator_dev *rdev;
+
+	if (regulator == NULL || IS_ERR(regulator))
+		return;
+
+	if (regulator->enabled) {
+		printk(KERN_WARNING "Releasing supply %s while enabled\n",
+		       regulator->supply_name);
+		WARN_ON(regulator->enabled);
+		regulator_disable(regulator);
+	}
+
+	mutex_lock(&regulator_list_mutex);
+	rdev = regulator->rdev;
+
+	/* remove any sysfs entries */
+	if (regulator->dev) {
+		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
+		kfree(regulator->supply_name);
+		device_remove_file(regulator->dev, &regulator->dev_attr);
+		kfree(regulator->dev_attr.attr.name);
+	}
+	list_del(&regulator->list);
+	kfree(regulator);
+
+	module_put(rdev->owner);
+	mutex_unlock(&regulator_list_mutex);
+}
+EXPORT_SYMBOL_GPL(regulator_put);
+
+/* locks held by regulator_enable() */
+static int _regulator_enable(struct regulator_dev *rdev)
+{
+	int ret = -EINVAL;
+
+	if (!rdev->constraints) {
+		printk(KERN_ERR "%s: %s has no constraints\n",
+		       __func__, rdev->desc->name);
+		return ret;
+	}
+
+	/* do we need to enable the supply regulator first */
+	if (rdev->supply) {
+		ret = _regulator_enable(rdev->supply);
+		if (ret < 0) {
+			printk(KERN_ERR "%s: failed to enable %s: %d\n",
+			       __func__, rdev->desc->name, ret);
+			return ret;
+		}
+	}
+
+	/* check voltage and requested load before enabling */
+	if (rdev->desc->ops->enable) {
+
+		if (rdev->constraints &&
+			(rdev->constraints->valid_ops_mask &
+			REGULATOR_CHANGE_DRMS))
+			drms_uA_update(rdev);
+
+		ret = rdev->desc->ops->enable(rdev);
+		if (ret < 0) {
+			printk(KERN_ERR "%s: failed to enable %s: %d\n",
+			       __func__, rdev->desc->name, ret);
+			return ret;
+		}
+		rdev->use_count++;
+		return ret;
+	}
+
+	return ret;
+}
+
+/**
+ * regulator_enable - enable regulator output
+ * @regulator: regulator source
+ *
+ * Enable the regulator output at the predefined voltage or current value.
+ * NOTE: the output value can be set by other drivers, boot loader or may be
+ * hardwired in the regulator.
+ * NOTE: calls to regulator_enable() must be balanced with calls to
+ * regulator_disable().
+ */
+int regulator_enable(struct regulator *regulator)
+{
+	int ret;
+
+	if (regulator->enabled) {
+		printk(KERN_CRIT "Regulator %s already enabled\n",
+		       regulator->supply_name);
+		WARN_ON(regulator->enabled);
+		return 0;
+	}
+
+	mutex_lock(&regulator->rdev->mutex);
+	regulator->enabled = 1;
+	ret = _regulator_enable(regulator->rdev);
+	if (ret != 0)
+		regulator->enabled = 0;
+	mutex_unlock(&regulator->rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_enable);
+
+/* locks held by regulator_disable() */
+static int _regulator_disable(struct regulator_dev *rdev)
+{
+	int ret = 0;
+
+	/* are we the last user and permitted to disable ? */
+	if (rdev->use_count == 1 && !rdev->constraints->always_on) {
+
+		/* we are last user */
+		if (rdev->desc->ops->disable) {
+			ret = rdev->desc->ops->disable(rdev);
+			if (ret < 0) {
+				printk(KERN_ERR "%s: failed to disable %s\n",
+				       __func__, rdev->desc->name);
+				return ret;
+			}
+		}
+
+		/* decrease our supplies ref count and disable if required */
+		if (rdev->supply)
+			_regulator_disable(rdev->supply);
+
+		rdev->use_count = 0;
+	} else if (rdev->use_count > 1) {
+
+		if (rdev->constraints &&
+			(rdev->constraints->valid_ops_mask &
+			REGULATOR_CHANGE_DRMS))
+			drms_uA_update(rdev);
+
+		rdev->use_count--;
+	}
+	return ret;
+}
+
+/**
+ * regulator_disable - disable regulator output
+ * @regulator: regulator source
+ *
+ * Disable the regulator output voltage or current.
+ * NOTE: this will only disable the regulator output if no other consumer
+ * devices have it enabled.
+ * NOTE: calls to regulator_enable() must be balanced with calls to
+ * regulator_disable().
+ */
+int regulator_disable(struct regulator *regulator)
+{
+	int ret;
+
+	if (!regulator->enabled) {
+		printk(KERN_ERR "%s: not in use by this consumer\n",
+			__func__);
+		return 0;
+	}
+
+	mutex_lock(&regulator->rdev->mutex);
+	regulator->enabled = 0;
+	regulator->uA_load = 0;
+	ret = _regulator_disable(regulator->rdev);
+	mutex_unlock(&regulator->rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_disable);
+
+/* locks held by regulator_force_disable() */
+static int _regulator_force_disable(struct regulator_dev *rdev)
+{
+	int ret = 0;
+
+	/* force disable */
+	if (rdev->desc->ops->disable) {
+		/* ah well, who wants to live forever... */
+		ret = rdev->desc->ops->disable(rdev);
+		if (ret < 0) {
+			printk(KERN_ERR "%s: failed to force disable %s\n",
+			       __func__, rdev->desc->name);
+			return ret;
+		}
+		/* notify other consumers that power has been forced off */
+		_notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE,
+			NULL);
+	}
+
+	/* decrease our supplies ref count and disable if required */
+	if (rdev->supply)
+		_regulator_disable(rdev->supply);
+
+	rdev->use_count = 0;
+	return ret;
+}
+
+/**
+ * regulator_force_disable - force disable regulator output
+ * @regulator: regulator source
+ *
+ * Forcibly disable the regulator output voltage or current.
+ * NOTE: this *will* disable the regulator output even if other consumer
+ * devices have it enabled. This should be used for situations when device
+ * damage will likely occur if the regulator is not disabled (e.g. over temp).
+ */
+int regulator_force_disable(struct regulator *regulator)
+{
+	int ret;
+
+	mutex_lock(&regulator->rdev->mutex);
+	regulator->enabled = 0;
+	regulator->uA_load = 0;
+	ret = _regulator_force_disable(regulator->rdev);
+	mutex_unlock(&regulator->rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_force_disable);
+
+static int _regulator_is_enabled(struct regulator_dev *rdev)
+{
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+
+	/* sanity check */
+	if (!rdev->desc->ops->is_enabled) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = rdev->desc->ops->is_enabled(rdev);
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+
+/**
+ * regulator_is_enabled - is the regulator output enabled
+ * @regulator: regulator source
+ *
+ * Returns zero for disabled otherwise return number of enable requests.
+ */
+int regulator_is_enabled(struct regulator *regulator)
+{
+	return _regulator_is_enabled(regulator->rdev);
+}
+EXPORT_SYMBOL_GPL(regulator_is_enabled);
+
+/**
+ * regulator_set_voltage - set regulator output voltage
+ * @regulator: regulator source
+ * @min_uV: Minimum required voltage in uV
+ * @max_uV: Maximum acceptable voltage in uV
+ *
+ * Sets a voltage regulator to the desired output voltage. This can be set
+ * during any regulator state. IOW, regulator can be disabled or enabled.
+ *
+ * If the regulator is enabled then the voltage will change to the new value
+ * immediately otherwise if the regulator is disabled the regulator will
+ * output at the new voltage when enabled.
+ *
+ * NOTE: If the regulator is shared between several devices then the lowest
+ * request voltage that meets the system constraints will be used.
+ * NOTE: Regulator system constraints must be set for this regulator before
+ * calling this function otherwise this call will fail.
+ */
+int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
+{
+	struct regulator_dev *rdev = regulator->rdev;
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+
+	/* sanity check */
+	if (!rdev->desc->ops->set_voltage) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* constraints check */
+	ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
+	if (ret < 0)
+		goto out;
+	regulator->min_uV = min_uV;
+	regulator->max_uV = max_uV;
+	ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV);
+
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_voltage);
+
+static int _regulator_get_voltage(struct regulator_dev *rdev)
+{
+	/* sanity check */
+	if (rdev->desc->ops->get_voltage)
+		return rdev->desc->ops->get_voltage(rdev);
+	else
+		return -EINVAL;
+}
+
+/**
+ * regulator_get_voltage - get regulator output voltage
+ * @regulator: regulator source
+ *
+ * This returns the current regulator voltage in uV.
+ *
+ * NOTE: If the regulator is disabled it will return the voltage value. This
+ * function should not be used to determine regulator state.
+ */
+int regulator_get_voltage(struct regulator *regulator)
+{
+	int ret;
+
+	mutex_lock(&regulator->rdev->mutex);
+
+	ret = _regulator_get_voltage(regulator->rdev);
+
+	mutex_unlock(&regulator->rdev->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_get_voltage);
+
+/**
+ * regulator_set_current_limit - set regulator output current limit
+ * @regulator: regulator source
+ * @min_uA: Minimuum supported current in uA
+ * @max_uA: Maximum supported current in uA
+ *
+ * Sets current sink to the desired output current. This can be set during
+ * any regulator state. IOW, regulator can be disabled or enabled.
+ *
+ * If the regulator is enabled then the current will change to the new value
+ * immediately otherwise if the regulator is disabled the regulator will
+ * output at the new current when enabled.
+ *
+ * NOTE: Regulator system constraints must be set for this regulator before
+ * calling this function otherwise this call will fail.
+ */
+int regulator_set_current_limit(struct regulator *regulator,
+			       int min_uA, int max_uA)
+{
+	struct regulator_dev *rdev = regulator->rdev;
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+
+	/* sanity check */
+	if (!rdev->desc->ops->set_current_limit) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* constraints check */
+	ret = regulator_check_current_limit(rdev, &min_uA, &max_uA);
+	if (ret < 0)
+		goto out;
+
+	ret = rdev->desc->ops->set_current_limit(rdev, min_uA, max_uA);
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_current_limit);
+
+static int _regulator_get_current_limit(struct regulator_dev *rdev)
+{
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+
+	/* sanity check */
+	if (!rdev->desc->ops->get_current_limit) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = rdev->desc->ops->get_current_limit(rdev);
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+
+/**
+ * regulator_get_current_limit - get regulator output current
+ * @regulator: regulator source
+ *
+ * This returns the current supplied by the specified current sink in uA.
+ *
+ * NOTE: If the regulator is disabled it will return the current value. This
+ * function should not be used to determine regulator state.
+ */
+int regulator_get_current_limit(struct regulator *regulator)
+{
+	return _regulator_get_current_limit(regulator->rdev);
+}
+EXPORT_SYMBOL_GPL(regulator_get_current_limit);
+
+/**
+ * regulator_set_mode - set regulator operating mode
+ * @regulator: regulator source
+ * @mode: operating mode - one of the REGULATOR_MODE constants
+ *
+ * Set regulator operating mode to increase regulator efficiency or improve
+ * regulation performance.
+ *
+ * NOTE: Regulator system constraints must be set for this regulator before
+ * calling this function otherwise this call will fail.
+ */
+int regulator_set_mode(struct regulator *regulator, unsigned int mode)
+{
+	struct regulator_dev *rdev = regulator->rdev;
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+
+	/* sanity check */
+	if (!rdev->desc->ops->set_mode) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* constraints check */
+	ret = regulator_check_mode(rdev, mode);
+	if (ret < 0)
+		goto out;
+
+	ret = rdev->desc->ops->set_mode(rdev, mode);
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_mode);
+
+static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
+{
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+
+	/* sanity check */
+	if (!rdev->desc->ops->get_mode) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = rdev->desc->ops->get_mode(rdev);
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+
+/**
+ * regulator_get_mode - get regulator operating mode
+ * @regulator: regulator source
+ *
+ * Get the current regulator operating mode.
+ */
+unsigned int regulator_get_mode(struct regulator *regulator)
+{
+	return _regulator_get_mode(regulator->rdev);
+}
+EXPORT_SYMBOL_GPL(regulator_get_mode);
+
+/**
+ * regulator_set_optimum_mode - set regulator optimum operating mode
+ * @regulator: regulator source
+ * @uA_load: load current
+ *
+ * Notifies the regulator core of a new device load. This is then used by
+ * DRMS (if enabled by constraints) to set the most efficient regulator
+ * operating mode for the new regulator loading.
+ *
+ * Consumer devices notify their supply regulator of the maximum power
+ * they will require (can be taken from device datasheet in the power
+ * consumption tables) when they change operational status and hence power
+ * state. Examples of operational state changes that can affect power
+ * consumption are :-
+ *
+ *    o Device is opened / closed.
+ *    o Device I/O is about to begin or has just finished.
+ *    o Device is idling in between work.
+ *
+ * This information is also exported via sysfs to userspace.
+ *
+ * DRMS will sum the total requested load on the regulator and change
+ * to the most efficient operating mode if platform constraints allow.
+ *
+ * Returns the new regulator mode or error.
+ */
+int regulator_set_optimum_mode(struct regulator *regulator, int uA_load)
+{
+	struct regulator_dev *rdev = regulator->rdev;
+	struct regulator *consumer;
+	int ret, output_uV, input_uV, total_uA_load = 0;
+	unsigned int mode;
+
+	mutex_lock(&rdev->mutex);
+
+	regulator->uA_load = uA_load;
+	ret = regulator_check_drms(rdev);
+	if (ret < 0)
+		goto out;
+	ret = -EINVAL;
+
+	/* sanity check */
+	if (!rdev->desc->ops->get_optimum_mode)
+		goto out;
+
+	/* get output voltage */
+	output_uV = rdev->desc->ops->get_voltage(rdev);
+	if (output_uV <= 0) {
+		printk(KERN_ERR "%s: invalid output voltage found for %s\n",
+			__func__, rdev->desc->name);
+		goto out;
+	}
+
+	/* get input voltage */
+	if (rdev->supply && rdev->supply->desc->ops->get_voltage)
+		input_uV = rdev->supply->desc->ops->get_voltage(rdev->supply);
+	else
+		input_uV = rdev->constraints->input_uV;
+	if (input_uV <= 0) {
+		printk(KERN_ERR "%s: invalid input voltage found for %s\n",
+			__func__, rdev->desc->name);
+		goto out;
+	}
+
+	/* calc total requested load for this regulator */
+	list_for_each_entry(consumer, &rdev->consumer_list, list)
+	    total_uA_load += consumer->uA_load;
+
+	mode = rdev->desc->ops->get_optimum_mode(rdev,
+						 input_uV, output_uV,
+						 total_uA_load);
+	if (ret <= 0) {
+		printk(KERN_ERR "%s: failed to get optimum mode for %s @"
+			" %d uA %d -> %d uV\n", __func__, rdev->desc->name,
+			total_uA_load, input_uV, output_uV);
+		goto out;
+	}
+
+	ret = rdev->desc->ops->set_mode(rdev, mode);
+	if (ret <= 0) {
+		printk(KERN_ERR "%s: failed to set optimum mode %x for %s\n",
+			__func__, mode, rdev->desc->name);
+		goto out;
+	}
+	ret = mode;
+out:
+	mutex_unlock(&rdev->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_optimum_mode);
+
+/**
+ * regulator_register_notifier - register regulator event notifier
+ * @regulator: regulator source
+ * @notifier_block: notifier block
+ *
+ * Register notifier block to receive regulator events.
+ */
+int regulator_register_notifier(struct regulator *regulator,
+			      struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&regulator->rdev->notifier,
+						nb);
+}
+EXPORT_SYMBOL_GPL(regulator_register_notifier);
+
+/**
+ * regulator_unregister_notifier - unregister regulator event notifier
+ * @regulator: regulator source
+ * @notifier_block: notifier block
+ *
+ * Unregister regulator event notifier block.
+ */
+int regulator_unregister_notifier(struct regulator *regulator,
+				struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&regulator->rdev->notifier,
+						  nb);
+}
+EXPORT_SYMBOL_GPL(regulator_unregister_notifier);
+
+/* notify regulator consumers and downstream regulator consumers */
+static void _notifier_call_chain(struct regulator_dev *rdev,
+				  unsigned long event, void *data)
+{
+	struct regulator_dev *_rdev;
+
+	/* call rdev chain first */
+	mutex_lock(&rdev->mutex);
+	blocking_notifier_call_chain(&rdev->notifier, event, NULL);
+	mutex_unlock(&rdev->mutex);
+
+	/* now notify regulator we supply */
+	list_for_each_entry(_rdev, &rdev->supply_list, slist)
+		_notifier_call_chain(_rdev, event, data);
+}
+
+/**
+ * regulator_bulk_get - get multiple regulator consumers
+ *
+ * @dev:           Device to supply
+ * @num_consumers: Number of consumers to register
+ * @consumers:     Configuration of consumers; clients are stored here.
+ *
+ * @return 0 on success, an errno on failure.
+ *
+ * This helper function allows drivers to get several regulator
+ * consumers in one operation.  If any of the regulators cannot be
+ * acquired then any regulators that were allocated will be freed
+ * before returning to the caller.
+ */
+int regulator_bulk_get(struct device *dev, int num_consumers,
+		       struct regulator_bulk_data *consumers)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < num_consumers; i++)
+		consumers[i].consumer = NULL;
+
+	for (i = 0; i < num_consumers; i++) {
+		consumers[i].consumer = regulator_get(dev,
+						      consumers[i].supply);
+		if (IS_ERR(consumers[i].consumer)) {
+			dev_err(dev, "Failed to get supply '%s'\n",
+				consumers[i].supply);
+			ret = PTR_ERR(consumers[i].consumer);
+			consumers[i].consumer = NULL;
+			goto err;
+		}
+	}
+
+	return 0;
+
+err:
+	for (i = 0; i < num_consumers && consumers[i].consumer; i++)
+		regulator_put(consumers[i].consumer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_bulk_get);
+
+/**
+ * regulator_bulk_enable - enable multiple regulator consumers
+ *
+ * @num_consumers: Number of consumers
+ * @consumers:     Consumer data; clients are stored here.
+ * @return         0 on success, an errno on failure
+ *
+ * This convenience API allows consumers to enable multiple regulator
+ * clients in a single API call.  If any consumers cannot be enabled
+ * then any others that were enabled will be disabled again prior to
+ * return.
+ */
+int regulator_bulk_enable(int num_consumers,
+			  struct regulator_bulk_data *consumers)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < num_consumers; i++) {
+		ret = regulator_enable(consumers[i].consumer);
+		if (ret != 0)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	printk(KERN_ERR "Failed to enable %s\n", consumers[i].supply);
+	for (i = 0; i < num_consumers; i++)
+		regulator_disable(consumers[i].consumer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_bulk_enable);
+
+/**
+ * regulator_bulk_disable - disable multiple regulator consumers
+ *
+ * @num_consumers: Number of consumers
+ * @consumers:     Consumer data; clients are stored here.
+ * @return         0 on success, an errno on failure
+ *
+ * This convenience API allows consumers to disable multiple regulator
+ * clients in a single API call.  If any consumers cannot be enabled
+ * then any others that were disabled will be disabled again prior to
+ * return.
+ */
+int regulator_bulk_disable(int num_consumers,
+			   struct regulator_bulk_data *consumers)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < num_consumers; i++) {
+		ret = regulator_disable(consumers[i].consumer);
+		if (ret != 0)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	printk(KERN_ERR "Failed to disable %s\n", consumers[i].supply);
+	for (i = 0; i < num_consumers; i++)
+		regulator_enable(consumers[i].consumer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_bulk_disable);
+
+/**
+ * regulator_bulk_free - free multiple regulator consumers
+ *
+ * @num_consumers: Number of consumers
+ * @consumers:     Consumer data; clients are stored here.
+ *
+ * This convenience API allows consumers to free multiple regulator
+ * clients in a single API call.
+ */
+void regulator_bulk_free(int num_consumers,
+			 struct regulator_bulk_data *consumers)
+{
+	int i;
+
+	for (i = 0; i < num_consumers; i++) {
+		regulator_put(consumers[i].consumer);
+		consumers[i].consumer = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(regulator_bulk_free);
+
+/**
+ * regulator_notifier_call_chain - call regulator event notifier
+ * @regulator: regulator source
+ * @event: notifier block
+ * @data:
+ *
+ * Called by regulator drivers to notify clients a regulator event has
+ * occurred. We also notify regulator clients downstream.
+ */
+int regulator_notifier_call_chain(struct regulator_dev *rdev,
+				  unsigned long event, void *data)
+{
+	_notifier_call_chain(rdev, event, data);
+	return NOTIFY_DONE;
+
+}
+EXPORT_SYMBOL_GPL(regulator_notifier_call_chain);
+
+/**
+ * regulator_register - register regulator
+ * @regulator: regulator source
+ * @reg_data: private regulator data
+ *
+ * Called by regulator drivers to register a regulator.
+ * Returns 0 on success.
+ */
+struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
+					  void *reg_data)
+{
+	static atomic_t regulator_no = ATOMIC_INIT(0);
+	struct regulator_dev *rdev;
+	int ret;
+
+	if (regulator_desc == NULL)
+		return ERR_PTR(-EINVAL);
+
+	if (regulator_desc->name == NULL || regulator_desc->ops == NULL)
+		return ERR_PTR(-EINVAL);
+
+	if (!regulator_desc->type == REGULATOR_VOLTAGE &&
+	    !regulator_desc->type == REGULATOR_CURRENT)
+		return ERR_PTR(-EINVAL);
+
+	rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL);
+	if (rdev == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&regulator_list_mutex);
+
+	mutex_init(&rdev->mutex);
+	rdev->reg_data = reg_data;
+	rdev->owner = regulator_desc->owner;
+	rdev->desc = regulator_desc;
+	INIT_LIST_HEAD(&rdev->consumer_list);
+	INIT_LIST_HEAD(&rdev->supply_list);
+	INIT_LIST_HEAD(&rdev->list);
+	INIT_LIST_HEAD(&rdev->slist);
+	BLOCKING_INIT_NOTIFIER_HEAD(&rdev->notifier);
+
+	rdev->dev.class = &regulator_class;
+	device_initialize(&rdev->dev);
+	snprintf(rdev->dev.bus_id, sizeof(rdev->dev.bus_id),
+		 "regulator_%ld_%s",
+		 (unsigned long)atomic_inc_return(&regulator_no) - 1,
+		 regulator_desc->name);
+
+	ret = device_add(&rdev->dev);
+	if (ret == 0)
+		list_add(&rdev->list, &regulator_list);
+	else {
+		kfree(rdev);
+		rdev = ERR_PTR(ret);
+	}
+	mutex_unlock(&regulator_list_mutex);
+	return rdev;
+}
+EXPORT_SYMBOL_GPL(regulator_register);
+
+/**
+ * regulator_unregister - unregister regulator
+ * @regulator: regulator source
+ *
+ * Called by regulator drivers to unregister a regulator.
+ */
+void regulator_unregister(struct regulator_dev *rdev)
+{
+	if (rdev == NULL)
+		return;
+
+	mutex_lock(&regulator_list_mutex);
+	list_del(&rdev->list);
+	if (rdev->supply)
+		sysfs_remove_link(&rdev->dev.kobj, "supply");
+	device_unregister(&rdev->dev);
+	mutex_unlock(&regulator_list_mutex);
+}
+EXPORT_SYMBOL_GPL(regulator_unregister);
+
+/**
+ * regulator_set_supply - set regulator supply regulator
+ * @regulator: regulator name
+ * @supply: supply regulator name
+ *
+ * Called by platform initialisation code to set the supply regulator for this
+ * regulator. This ensures that a regulators supply will also be enabled by the
+ * core if it's child is enabled.
+ */
+int regulator_set_supply(const char *regulator, const char *supply)
+{
+	struct regulator_dev *rdev, *supply_rdev;
+	int err;
+
+	if (regulator == NULL || supply == NULL)
+		return -EINVAL;
+
+	mutex_lock(&regulator_list_mutex);
+
+	list_for_each_entry(rdev, &regulator_list, list) {
+		if (!strcmp(rdev->desc->name, regulator))
+			goto found_regulator;
+	}
+	mutex_unlock(&regulator_list_mutex);
+	return -ENODEV;
+
+found_regulator:
+	list_for_each_entry(supply_rdev, &regulator_list, list) {
+		if (!strcmp(supply_rdev->desc->name, supply))
+			goto found_supply;
+	}
+	mutex_unlock(&regulator_list_mutex);
+	return -ENODEV;
+
+found_supply:
+	err = sysfs_create_link(&rdev->dev.kobj, &supply_rdev->dev.kobj,
+				"supply");
+	if (err) {
+		printk(KERN_ERR
+		       "%s: could not add device link %s err %d\n",
+		       __func__, supply_rdev->dev.kobj.name, err);
+		       goto out;
+	}
+	rdev->supply = supply_rdev;
+	list_add(&rdev->slist, &supply_rdev->supply_list);
+out:
+	mutex_unlock(&regulator_list_mutex);
+	return err;
+}
+EXPORT_SYMBOL_GPL(regulator_set_supply);
+
+/**
+ * regulator_get_supply - get regulator supply regulator
+ * @regulator: regulator name
+ *
+ * Returns the supply supply regulator name or NULL if no supply regulator
+ * exists (i.e the regulator is supplied directly from USB, Line, Battery, etc)
+ */
+const char *regulator_get_supply(const char *regulator)
+{
+	struct regulator_dev *rdev;
+
+	if (regulator == NULL)
+		return NULL;
+
+	mutex_lock(&regulator_list_mutex);
+	list_for_each_entry(rdev, &regulator_list, list) {
+		if (!strcmp(rdev->desc->name, regulator))
+			goto found;
+	}
+	mutex_unlock(&regulator_list_mutex);
+	return NULL;
+
+found:
+	mutex_unlock(&regulator_list_mutex);
+	if (rdev->supply)
+		return rdev->supply->desc->name;
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(regulator_get_supply);
+
+/**
+ * regulator_set_machine_constraints - sets regulator constraints
+ * @regulator: regulator source
+ *
+ * Allows platform initialisation code to define and constrain
+ * regulator circuits e.g. valid voltage/current ranges, etc.  NOTE:
+ * Constraints *must* be set by platform code in order for some
+ * regulator operations to proceed i.e. set_voltage, set_current_limit,
+ * set_mode.
+ */
+int regulator_set_machine_constraints(const char *regulator_name,
+	struct regulation_constraints *constraints)
+{
+	struct regulator_dev *rdev;
+	int ret = 0;
+
+	if (regulator_name == NULL)
+		return -EINVAL;
+
+	mutex_lock(&regulator_list_mutex);
+
+	list_for_each_entry(rdev, &regulator_list, list) {
+		if (!strcmp(regulator_name, rdev->desc->name))
+			goto found;
+	}
+	ret = -ENODEV;
+	goto out;
+
+found:
+	mutex_lock(&rdev->mutex);
+	rdev->constraints = constraints;
+
+	/* do we need to apply the constraint voltage */
+	if (rdev->constraints->apply_uV &&
+		rdev->constraints->min_uV == rdev->constraints->max_uV &&
+		rdev->desc->ops->set_voltage) {
+		ret = rdev->desc->ops->set_voltage(rdev,
+			rdev->constraints->min_uV, rdev->constraints->max_uV);
+			if (ret < 0) {
+				printk(KERN_ERR "%s: failed to apply %duV"
+					" constraint\n", __func__,
+					rdev->constraints->min_uV);
+				rdev->constraints = NULL;
+				goto out;
+			}
+	}
+
+	/* are we enabled at boot time by firmware / bootloader */
+	if (rdev->constraints->boot_on)
+		rdev->use_count = 1;
+
+	/* do we need to setup our suspend state */
+	if (constraints->initial_state)
+		ret = suspend_prepare(rdev, constraints->initial_state);
+
+	print_constraints(rdev);
+	mutex_unlock(&rdev->mutex);
+
+out:
+	mutex_unlock(&regulator_list_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_machine_constraints);
+
+
+/**
+ * regulator_set_device_supply: Bind a regulator to a symbolic supply
+ * @regulator: regulator source
+ * @dev:       device the supply applies to
+ * @supply:    symbolic name for supply
+ *
+ * Allows platform initialisation code to map physical regulator
+ * sources to symbolic names for supplies for use by devices.  Devices
+ * should use these symbolic names to request regulators, avoiding the
+ * need to provide board-specific regulator names as platform data.
+ */
+int regulator_set_device_supply(const char *regulator, struct device *dev,
+				const char *supply)
+{
+	struct regulator_map *node;
+
+	if (regulator == NULL || supply == NULL)
+		return -EINVAL;
+
+	node = kmalloc(sizeof(struct regulator_map), GFP_KERNEL);
+	if (node == NULL)
+		return -ENOMEM;
+
+	node->regulator = regulator;
+	node->dev = dev;
+	node->supply = supply;
+
+	mutex_lock(&regulator_list_mutex);
+	list_add(&node->list, &regulator_map_list);
+	mutex_unlock(&regulator_list_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regulator_set_device_supply);
+
+/**
+ * regulator_suspend_prepare: prepare regulators for system wide suspend
+ * @state: system suspend state
+ *
+ * Configure each regulator with it's suspend operating parameters for state.
+ * This will usually be called by machine suspend code prior to supending.
+ */
+int regulator_suspend_prepare(suspend_state_t state)
+{
+	struct regulator_dev *rdev;
+	int ret = 0;
+
+	/* ON is handled by regulator active state */
+	if (state == PM_SUSPEND_ON)
+		return -EINVAL;
+
+	mutex_lock(&regulator_list_mutex);
+	list_for_each_entry(rdev, &regulator_list, list) {
+
+		mutex_lock(&rdev->mutex);
+		ret = suspend_prepare(rdev, state);
+		mutex_unlock(&rdev->mutex);
+
+		if (ret < 0) {
+			printk(KERN_ERR "%s: failed to prepare %s\n",
+				__func__, rdev->desc->name);
+			goto out;
+		}
+	}
+out:
+	mutex_unlock(&regulator_list_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
+
+/**
+ * rdev_get_drvdata - get rdev regulator driver data
+ * @regulator: regulator
+ *
+ * Get rdev regulator driver private data. This call can be used in the
+ * regulator driver context.
+ */
+void *rdev_get_drvdata(struct regulator_dev *rdev)
+{
+	return rdev->reg_data;
+}
+EXPORT_SYMBOL_GPL(rdev_get_drvdata);
+
+/**
+ * regulator_get_drvdata - get regulator driver data
+ * @regulator: regulator
+ *
+ * Get regulator driver private data. This call can be used in the consumer
+ * driver context when non API regulator specific functions need to be called.
+ */
+void *regulator_get_drvdata(struct regulator *regulator)
+{
+	return regulator->rdev->reg_data;
+}
+EXPORT_SYMBOL_GPL(regulator_get_drvdata);
+
+/**
+ * regulator_set_drvdata - set regulator driver data
+ * @regulator: regulator
+ * @data: data
+ */
+void regulator_set_drvdata(struct regulator *regulator, void *data)
+{
+	regulator->rdev->reg_data = data;
+}
+EXPORT_SYMBOL_GPL(regulator_set_drvdata);
+
+/**
+ * regulator_get_id - get regulator ID
+ * @regulator: regulator
+ */
+int rdev_get_id(struct regulator_dev *rdev)
+{
+	return rdev->desc->id;
+}
+EXPORT_SYMBOL_GPL(rdev_get_id);
+
+static int __init regulator_init(void)
+{
+	printk(KERN_INFO "regulator: core version %s\n", REGULATOR_VERSION);
+	return class_register(&regulator_class);
+}
+
+/* init early to allow our consumers to complete system booting */
+core_initcall(regulator_init);