linux/drivers/regulator/userspace-consumer.c

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/*
* userspace-consumer.c
*
* Copyright 2009 CompuLab, Ltd.
*
* Author: Mike Rapoport <mike@compulab.co.il>
*
* Based of virtual consumer driver:
* 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/regulator/userspace-consumer.h>
struct userspace_consumer_data {
const char *name;
struct mutex lock;
bool enabled;
int num_supplies;
struct regulator_bulk_data *supplies;
};
static ssize_t reg_show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct userspace_consumer_data *data = dev_get_drvdata(dev);
return sprintf(buf, "%s\n", data->name);
}
static ssize_t reg_show_state(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct userspace_consumer_data *data = dev_get_drvdata(dev);
if (data->enabled)
return sprintf(buf, "enabled\n");
return sprintf(buf, "disabled\n");
}
static ssize_t reg_set_state(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct userspace_consumer_data *data = dev_get_drvdata(dev);
bool enabled;
int ret;
/*
* sysfs_streq() doesn't need the \n's, but we add them so the strings
* will be shared with show_state(), above.
*/
if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
enabled = true;
else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
enabled = false;
else {
dev_err(dev, "Configuring invalid mode\n");
return count;
}
mutex_lock(&data->lock);
if (enabled != data->enabled) {
if (enabled)
ret = regulator_bulk_enable(data->num_supplies,
data->supplies);
else
ret = regulator_bulk_disable(data->num_supplies,
data->supplies);
if (ret == 0)
data->enabled = enabled;
else
dev_err(dev, "Failed to configure state: %d\n", ret);
}
mutex_unlock(&data->lock);
return count;
}
static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
static struct attribute *attributes[] = {
&dev_attr_name.attr,
&dev_attr_state.attr,
NULL,
};
static const struct attribute_group attr_group = {
.attrs = attributes,
};
static int regulator_userspace_consumer_probe(struct platform_device *pdev)
{
struct regulator_userspace_consumer_data *pdata;
struct userspace_consumer_data *drvdata;
int ret;
pdata = pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
drvdata = kzalloc(sizeof(struct userspace_consumer_data), GFP_KERNEL);
if (drvdata == NULL)
return -ENOMEM;
drvdata->name = pdata->name;
drvdata->num_supplies = pdata->num_supplies;
drvdata->supplies = pdata->supplies;
mutex_init(&drvdata->lock);
ret = regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
drvdata->supplies);
if (ret) {
dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
goto err_alloc_supplies;
}
ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
if (ret != 0)
goto err_create_attrs;
if (pdata->init_on) {
ret = regulator_bulk_enable(drvdata->num_supplies,
drvdata->supplies);
if (ret) {
dev_err(&pdev->dev,
"Failed to set initial state: %d\n", ret);
goto err_enable;
}
}
drvdata->enabled = pdata->init_on;
platform_set_drvdata(pdev, drvdata);
return 0;
err_enable:
sysfs_remove_group(&pdev->dev.kobj, &attr_group);
err_create_attrs:
regulator_bulk_free(drvdata->num_supplies, drvdata->supplies);
err_alloc_supplies:
kfree(drvdata);
return ret;
}
static int regulator_userspace_consumer_remove(struct platform_device *pdev)
{
struct userspace_consumer_data *data = platform_get_drvdata(pdev);
sysfs_remove_group(&pdev->dev.kobj, &attr_group);
if (data->enabled)
regulator_bulk_disable(data->num_supplies, data->supplies);
regulator_bulk_free(data->num_supplies, data->supplies);
kfree(data);
return 0;
}
static struct platform_driver regulator_userspace_consumer_driver = {
.probe = regulator_userspace_consumer_probe,
.remove = regulator_userspace_consumer_remove,
.driver = {
.name = "reg-userspace-consumer",
},
};
static int __init regulator_userspace_consumer_init(void)
{
return platform_driver_register(&regulator_userspace_consumer_driver);
}
module_init(regulator_userspace_consumer_init);
static void __exit regulator_userspace_consumer_exit(void)
{
platform_driver_unregister(&regulator_userspace_consumer_driver);
}
module_exit(regulator_userspace_consumer_exit);
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
MODULE_LICENSE("GPL");