/*
* 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>
struct virtual_consumer_data {
struct mutex lock;
struct regulator *regulator;
int enabled;
int min_uV;
int max_uV;
int min_uA;
int max_uA;
unsigned int mode;
};
static void update_voltage_constraints(struct virtual_consumer_data *data)
{
int ret;
if (data->min_uV && data->max_uV
&& data->min_uV <= data->max_uV) {
ret = regulator_set_voltage(data->regulator,
data->min_uV, data->max_uV);
if (ret != 0) {
printk(KERN_ERR "regulator_set_voltage() failed: %d\n",
ret);
return;
}
}
if (data->min_uV && data->max_uV && !data->enabled) {
ret = regulator_enable(data->regulator);
if (ret == 0)
data->enabled = 1;
else
printk(KERN_ERR "regulator_enable() failed: %d\n",
ret);
}
if (!(data->min_uV && data->max_uV) && data->enabled) {
ret = regulator_disable(data->regulator);
if (ret == 0)
data->enabled = 0;
else
printk(KERN_ERR "regulator_disable() failed: %d\n",
ret);
}
}
static void update_current_limit_constraints(struct virtual_consumer_data
*data)
{
int ret;
if (data->max_uA
&& data->min_uA <= data->max_uA) {
ret = regulator_set_current_limit(data->regulator,
data->min_uA, data->max_uA);
if (ret != 0) {
pr_err("regulator_set_current_limit() failed: %d\n",
ret);
return;
}
}
if (data->max_uA && !data->enabled) {
ret = regulator_enable(data->regulator);
if (ret == 0)
data->enabled = 1;
else
printk(KERN_ERR "regulator_enable() failed: %d\n",
ret);
}
if (!(data->min_uA && data->max_uA) && data->enabled) {
ret = regulator_disable(data->regulator);
if (ret == 0)
data->enabled = 0;
else
printk(KERN_ERR "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 (strict_strtol(buf, 10, &val) != 0)
return count;
mutex_lock(&data->lock);
data->min_uV = val;
update_voltage_constraints(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 (strict_strtol(buf, 10, &val) != 0)
return count;
mutex_lock(&data->lock);
data->max_uV = val;
update_voltage_constraints(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 (strict_strtol(buf, 10, &val) != 0)
return count;
mutex_lock(&data->lock);
data->min_uA = val;
update_current_limit_constraints(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 (strict_strtol(buf, 10, &val) != 0)
return count;
mutex_lock(&data->lock);
data->max_uA = val;
update_current_limit_constraints(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 device_attribute *attributes[] = {
&dev_attr_min_microvolts,
&dev_attr_max_microvolts,
&dev_attr_min_microamps,
&dev_attr_max_microamps,
&dev_attr_mode,
};
static int regulator_virtual_consumer_probe(struct platform_device *pdev)
{
char *reg_id = pdev->dev.platform_data;
struct virtual_consumer_data *drvdata;
int ret, i;
drvdata = kzalloc(sizeof(struct virtual_consumer_data), GFP_KERNEL);
if (drvdata == NULL) {
ret = -ENOMEM;
goto err;
}
mutex_init(&drvdata->lock);
drvdata->regulator = regulator_get(&pdev->dev, reg_id);
if (IS_ERR(drvdata->regulator)) {
ret = PTR_ERR(drvdata->regulator);
goto err;
}
for (i = 0; i < ARRAY_SIZE(attributes); i++) {
ret = device_create_file(&pdev->dev, attributes[i]);
if (ret != 0)
goto err;
}
drvdata->mode = regulator_get_mode(drvdata->regulator);
platform_set_drvdata(pdev, drvdata);
return 0;
err:
for (i = 0; i < ARRAY_SIZE(attributes); i++)
device_remove_file(&pdev->dev, attributes[i]);
kfree(drvdata);
return ret;
}
static int regulator_virtual_consumer_remove(struct platform_device *pdev)
{
struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
int i;
for (i = 0; i < ARRAY_SIZE(attributes); i++)
device_remove_file(&pdev->dev, attributes[i]);
if (drvdata->enabled)
regulator_disable(drvdata->regulator);
regulator_put(drvdata->regulator);
kfree(drvdata);
return 0;
}
static struct platform_driver regulator_virtual_consumer_driver = {
.probe = regulator_virtual_consumer_probe,
.remove = regulator_virtual_consumer_remove,
.driver = {
.name = "reg-virt-consumer",
},
};
static int __init regulator_virtual_consumer_init(void)
{
return platform_driver_register(®ulator_virtual_consumer_driver);
}
module_init(regulator_virtual_consumer_init);
static void __exit regulator_virtual_consumer_exit(void)
{
platform_driver_unregister(®ulator_virtual_consumer_driver);
}
module_exit(regulator_virtual_consumer_exit);
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("Virtual regulator consumer");
MODULE_LICENSE("GPL");
