drivers/regulator/virtual.c - maze/linux - Git at Google

 /*
  * reg-virtual-consumer.c
  *
  * Copyright 2008 Wolfson Microelectronics PLC.
  *
  * Author: Mark Brown <broonie@opensource.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/err.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/module.h>

 struct virtual_consumer_data {
 	struct mutex lock;
 	struct regulator *regulator;
 	bool enabled;
 	int min_uV;
 	int max_uV;
 	int min_uA;
 	int max_uA;
 	unsigned int mode;
 };

 static void update_voltage_constraints(struct device *dev,
 				       struct virtual_consumer_data *data)
 {
 	int ret;

 	if (data->min_uV && data->max_uV
 	    && data->min_uV <= data->max_uV) {
 		dev_dbg(dev, "Requesting %d-%duV\n",
 			data->min_uV, data->max_uV);
 		ret = regulator_set_voltage(data->regulator,
 					data->min_uV, data->max_uV);
 		if (ret != 0) {
 			dev_err(dev,
 				"regulator_set_voltage() failed: %d\n", ret);
 			return;
 		}
 	}

 	if (data->min_uV && data->max_uV && !data->enabled) {
 		dev_dbg(dev, "Enabling regulator\n");
 		ret = regulator_enable(data->regulator);
 		if (ret == 0)
 			data->enabled = true;
 		else
 			dev_err(dev, "regulator_enable() failed: %d\n",
 				ret);
 	}

 	if (!(data->min_uV && data->max_uV) && data->enabled) {
 		dev_dbg(dev, "Disabling regulator\n");
 		ret = regulator_disable(data->regulator);
 		if (ret == 0)
 			data->enabled = false;
 		else
 			dev_err(dev, "regulator_disable() failed: %d\n",
 				ret);
 	}
 }

 static void update_current_limit_constraints(struct device *dev,
 					  struct virtual_consumer_data *data)
 {
 	int ret;

 	if (data->max_uA
 	    && data->min_uA <= data->max_uA) {
 		dev_dbg(dev, "Requesting %d-%duA\n",
 			data->min_uA, data->max_uA);
 		ret = regulator_set_current_limit(data->regulator,
 					data->min_uA, data->max_uA);
 		if (ret != 0) {
 			dev_err(dev,
 				"regulator_set_current_limit() failed: %d\n",
 				ret);
 			return;
 		}
 	}

 	if (data->max_uA && !data->enabled) {
 		dev_dbg(dev, "Enabling regulator\n");
 		ret = regulator_enable(data->regulator);
 		if (ret == 0)
 			data->enabled = true;
 		else
 			dev_err(dev, "regulator_enable() failed: %d\n",
 				ret);
 	}

 	if (!(data->min_uA && data->max_uA) && data->enabled) {
 		dev_dbg(dev, "Disabling regulator\n");
 		ret = regulator_disable(data->regulator);
 		if (ret == 0)
 			data->enabled = false;
 		else
 			dev_err(dev, "regulator_disable() failed: %d\n",
 				ret);
 	}
 }

 static ssize_t show_min_uV(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	return sprintf(buf, "%d\n", data->min_uV);
 }

 static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	long val;

 	if (kstrtol(buf, 10, &val) != 0)
 		return count;

 	mutex_lock(&data->lock);

 	data->min_uV = val;
 	update_voltage_constraints(dev, data);

 	mutex_unlock(&data->lock);

 	return count;
 }

 static ssize_t show_max_uV(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	return sprintf(buf, "%d\n", data->max_uV);
 }

 static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	long val;

 	if (kstrtol(buf, 10, &val) != 0)
 		return count;

 	mutex_lock(&data->lock);

 	data->max_uV = val;
 	update_voltage_constraints(dev, data);

 	mutex_unlock(&data->lock);

 	return count;
 }

 static ssize_t show_min_uA(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	return sprintf(buf, "%d\n", data->min_uA);
 }

 static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	long val;

 	if (kstrtol(buf, 10, &val) != 0)
 		return count;

 	mutex_lock(&data->lock);

 	data->min_uA = val;
 	update_current_limit_constraints(dev, data);

 	mutex_unlock(&data->lock);

 	return count;
 }

 static ssize_t show_max_uA(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	return sprintf(buf, "%d\n", data->max_uA);
 }

 static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	long val;

 	if (kstrtol(buf, 10, &val) != 0)
 		return count;

 	mutex_lock(&data->lock);

 	data->max_uA = val;
 	update_current_limit_constraints(dev, data);

 	mutex_unlock(&data->lock);

 	return count;
 }

 static ssize_t show_mode(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);

 	switch (data->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");
 	default:
 		return sprintf(buf, "unknown\n");
 	}
 }

 static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
 			const char *buf, size_t count)
 {
 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
 	unsigned int mode;
 	int ret;

 	/*
 	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
 	 * will be shared with show_mode(), above.
 	 */
 	if (sysfs_streq(buf, "fast\n"))
 		mode = REGULATOR_MODE_FAST;
 	else if (sysfs_streq(buf, "normal\n"))
 		mode = REGULATOR_MODE_NORMAL;
 	else if (sysfs_streq(buf, "idle\n"))
 		mode = REGULATOR_MODE_IDLE;
 	else if (sysfs_streq(buf, "standby\n"))
 		mode = REGULATOR_MODE_STANDBY;
 	else {
 		dev_err(dev, "Configuring invalid mode\n");
 		return count;
 	}

 	mutex_lock(&data->lock);
 	ret = regulator_set_mode(data->regulator, mode);
 	if (ret == 0)
 		data->mode = mode;
 	else
 		dev_err(dev, "Failed to configure mode: %d\n", ret);
 	mutex_unlock(&data->lock);

 	return count;
 }

 static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV);
 static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV);
 static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA);
 static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA);
 static DEVICE_ATTR(mode, 0666, show_mode, set_mode);

 static struct attribute *regulator_virtual_attributes[] = {
 	&dev_attr_min_microvolts.attr,
 	&dev_attr_max_microvolts.attr,
 	&dev_attr_min_microamps.attr,
 	&dev_attr_max_microamps.attr,
 	&dev_attr_mode.attr,
 	NULL
 };

 static const struct attribute_group regulator_virtual_attr_group = {
 	.attrs	= regulator_virtual_attributes,
 };

 static int regulator_virtual_probe(struct platform_device *pdev)
 {
 	char *reg_id = pdev->dev.platform_data;
 	struct virtual_consumer_data *drvdata;
 	int ret;

 	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
 			       GFP_KERNEL);
 	if (drvdata == NULL)
 		return -ENOMEM;

 	mutex_init(&drvdata->lock);

 	drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
 	if (IS_ERR(drvdata->regulator)) {
 		ret = PTR_ERR(drvdata->regulator);
 		dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
 			reg_id, ret);
 		return ret;
 	}

 	ret = sysfs_create_group(&pdev->dev.kobj,
 				 &regulator_virtual_attr_group);
 	if (ret != 0) {
 		dev_err(&pdev->dev,
 			"Failed to create attribute group: %d\n", ret);
 		return ret;
 	}

 	drvdata->mode = regulator_get_mode(drvdata->regulator);

 	platform_set_drvdata(pdev, drvdata);

 	return 0;
 }

 static int regulator_virtual_remove(struct platform_device *pdev)
 {
 	struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);

 	sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);

 	if (drvdata->enabled)
 		regulator_disable(drvdata->regulator);

 	return 0;
 }

 static struct platform_driver regulator_virtual_consumer_driver = {
 	.probe		= regulator_virtual_probe,
 	.remove		= regulator_virtual_remove,
 	.driver		= {
 		.name		= "reg-virt-consumer",
 		.owner		= THIS_MODULE,
 	},
 };

 module_platform_driver(regulator_virtual_consumer_driver);

 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 MODULE_DESCRIPTION("Virtual regulator consumer");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:reg-virt-consumer");
	/*
	* reg-virtual-consumer.c
	*
	* Copyright 2008 Wolfson Microelectronics PLC.
	*
	* Author: Mark Brown <broonie@opensource.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/err.h>
	#include <linux/mutex.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/consumer.h>
	#include <linux/slab.h>
	#include <linux/module.h>

	struct virtual_consumer_data {
	struct mutex lock;
	struct regulator *regulator;
	bool enabled;
	int min_uV;
	int max_uV;
	int min_uA;
	int max_uA;
	unsigned int mode;
	};

	static void update_voltage_constraints(struct device *dev,
	struct virtual_consumer_data *data)
	{
	int ret;

	if (data->min_uV && data->max_uV
	&& data->min_uV <= data->max_uV) {
	dev_dbg(dev, "Requesting %d-%duV\n",
	data->min_uV, data->max_uV);
	ret = regulator_set_voltage(data->regulator,
	data->min_uV, data->max_uV);
	if (ret != 0) {
	dev_err(dev,
	"regulator_set_voltage() failed: %d\n", ret);
	return;
	}
	}

	if (data->min_uV && data->max_uV && !data->enabled) {
	dev_dbg(dev, "Enabling regulator\n");
	ret = regulator_enable(data->regulator);
	if (ret == 0)
	data->enabled = true;
	else
	dev_err(dev, "regulator_enable() failed: %d\n",
	ret);
	}

	if (!(data->min_uV && data->max_uV) && data->enabled) {
	dev_dbg(dev, "Disabling regulator\n");
	ret = regulator_disable(data->regulator);
	if (ret == 0)
	data->enabled = false;
	else
	dev_err(dev, "regulator_disable() failed: %d\n",
	ret);
	}
	}

	static void update_current_limit_constraints(struct device *dev,
	struct virtual_consumer_data *data)
	{
	int ret;

	if (data->max_uA
	&& data->min_uA <= data->max_uA) {
	dev_dbg(dev, "Requesting %d-%duA\n",
	data->min_uA, data->max_uA);
	ret = regulator_set_current_limit(data->regulator,
	data->min_uA, data->max_uA);
	if (ret != 0) {
	dev_err(dev,
	"regulator_set_current_limit() failed: %d\n",
	ret);
	return;
	}
	}

	if (data->max_uA && !data->enabled) {
	dev_dbg(dev, "Enabling regulator\n");
	ret = regulator_enable(data->regulator);
	if (ret == 0)
	data->enabled = true;
	else
	dev_err(dev, "regulator_enable() failed: %d\n",
	ret);
	}

	if (!(data->min_uA && data->max_uA) && data->enabled) {
	dev_dbg(dev, "Disabling regulator\n");
	ret = regulator_disable(data->regulator);
	if (ret == 0)
	data->enabled = false;
	else
	dev_err(dev, "regulator_disable() failed: %d\n",
	ret);
	}
	}

	static ssize_t show_min_uV(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->min_uV);
	}

	static ssize_t set_min_uV(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (kstrtol(buf, 10, &val) != 0)
	return count;

	mutex_lock(&data->lock);

	data->min_uV = val;
	update_voltage_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
	}

	static ssize_t show_max_uV(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->max_uV);
	}

	static ssize_t set_max_uV(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (kstrtol(buf, 10, &val) != 0)
	return count;

	mutex_lock(&data->lock);

	data->max_uV = val;
	update_voltage_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
	}

	static ssize_t show_min_uA(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->min_uA);
	}

	static ssize_t set_min_uA(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (kstrtol(buf, 10, &val) != 0)
	return count;

	mutex_lock(&data->lock);

	data->min_uA = val;
	update_current_limit_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
	}

	static ssize_t show_max_uA(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->max_uA);
	}

	static ssize_t set_max_uA(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (kstrtol(buf, 10, &val) != 0)
	return count;

	mutex_lock(&data->lock);

	data->max_uA = val;
	update_current_limit_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
	}

	static ssize_t show_mode(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);

	switch (data->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");
	default:
	return sprintf(buf, "unknown\n");
	}
	}

	static ssize_t set_mode(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	unsigned int mode;
	int ret;

	/*
	* sysfs_streq() doesn't need the \n's, but we add them so the strings
	* will be shared with show_mode(), above.
	*/
	if (sysfs_streq(buf, "fast\n"))
	mode = REGULATOR_MODE_FAST;
	else if (sysfs_streq(buf, "normal\n"))
	mode = REGULATOR_MODE_NORMAL;
	else if (sysfs_streq(buf, "idle\n"))
	mode = REGULATOR_MODE_IDLE;
	else if (sysfs_streq(buf, "standby\n"))
	mode = REGULATOR_MODE_STANDBY;
	else {
	dev_err(dev, "Configuring invalid mode\n");
	return count;
	}

	mutex_lock(&data->lock);
	ret = regulator_set_mode(data->regulator, mode);
	if (ret == 0)
	data->mode = mode;
	else
	dev_err(dev, "Failed to configure mode: %d\n", ret);
	mutex_unlock(&data->lock);

	return count;
	}

	static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV);
	static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV);
	static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA);
	static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA);
	static DEVICE_ATTR(mode, 0666, show_mode, set_mode);

	static struct attribute *regulator_virtual_attributes[] = {
	&dev_attr_min_microvolts.attr,
	&dev_attr_max_microvolts.attr,
	&dev_attr_min_microamps.attr,
	&dev_attr_max_microamps.attr,
	&dev_attr_mode.attr,
	NULL
	};

	static const struct attribute_group regulator_virtual_attr_group = {
	.attrs = regulator_virtual_attributes,
	};

	static int regulator_virtual_probe(struct platform_device *pdev)
	{
	char *reg_id = pdev->dev.platform_data;
	struct virtual_consumer_data *drvdata;
	int ret;

	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
	GFP_KERNEL);
	if (drvdata == NULL)
	return -ENOMEM;

	mutex_init(&drvdata->lock);

	drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
	if (IS_ERR(drvdata->regulator)) {
	ret = PTR_ERR(drvdata->regulator);
	dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
	reg_id, ret);
	return ret;
	}

	ret = sysfs_create_group(&pdev->dev.kobj,
	&regulator_virtual_attr_group);
	if (ret != 0) {
	dev_err(&pdev->dev,
	"Failed to create attribute group: %d\n", ret);
	return ret;
	}

	drvdata->mode = regulator_get_mode(drvdata->regulator);

	platform_set_drvdata(pdev, drvdata);

	return 0;
	}

	static int regulator_virtual_remove(struct platform_device *pdev)
	{
	struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);

	sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);

	if (drvdata->enabled)
	regulator_disable(drvdata->regulator);

	return 0;
	}

	static struct platform_driver regulator_virtual_consumer_driver = {
	.probe = regulator_virtual_probe,
	.remove = regulator_virtual_remove,
	.driver = {
	.name = "reg-virt-consumer",
	.owner = THIS_MODULE,
	},
	};

	module_platform_driver(regulator_virtual_consumer_driver);

	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	MODULE_DESCRIPTION("Virtual regulator consumer");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:reg-virt-consumer");