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/*
* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/module.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/msm-gpio-regulator.h>
struct gpio_vreg {
struct regulator_desc desc;
struct regulator_dev *rdev;
char *gpio_label;
char *name;
unsigned gpio;
int active_low;
bool gpio_requested;
};
static int gpio_vreg_request_gpio(struct gpio_vreg *vreg)
{
int rc = 0;
/* Request GPIO now if it hasn't been requested before. */
if (!vreg->gpio_requested) {
rc = gpio_request(vreg->gpio, vreg->gpio_label);
if (rc < 0) {
pr_err("failed to request gpio %u (%s), rc=%d\n",
vreg->gpio, vreg->gpio_label, rc);
return rc;
} else {
vreg->gpio_requested = true;
}
rc = gpio_sysfs_set_active_low(vreg->gpio, vreg->active_low);
if (rc < 0)
pr_err("active_low=%d failed for gpio %u, rc=%d\n",
vreg->active_low, vreg->gpio, rc);
}
return rc;
}
static int gpio_vreg_is_enabled(struct regulator_dev *rdev)
{
struct gpio_vreg *vreg = rdev_get_drvdata(rdev);
int rc;
rc = gpio_vreg_request_gpio(vreg);
if (rc < 0)
return rc;
return (gpio_get_value_cansleep(vreg->gpio) ? 1 : 0) ^ vreg->active_low;
}
static int gpio_vreg_enable(struct regulator_dev *rdev)
{
struct gpio_vreg *vreg = rdev_get_drvdata(rdev);
int rc;
rc = gpio_vreg_request_gpio(vreg);
if (rc < 0)
return rc;
return gpio_direction_output(vreg->gpio, !vreg->active_low);
}
static int gpio_vreg_disable(struct regulator_dev *rdev)
{
struct gpio_vreg *vreg = rdev_get_drvdata(rdev);
int rc;
rc = gpio_vreg_request_gpio(vreg);
if (rc < 0)
return rc;
return gpio_direction_output(vreg->gpio, vreg->active_low);
}
static struct regulator_ops gpio_vreg_ops = {
.enable = gpio_vreg_enable,
.disable = gpio_vreg_disable,
.is_enabled = gpio_vreg_is_enabled,
};
static int __devinit gpio_vreg_probe(struct platform_device *pdev)
{
const struct gpio_regulator_platform_data *pdata;
struct gpio_vreg *vreg;
int rc = 0;
pdata = pdev->dev.platform_data;
if (!pdata) {
pr_err("platform data required.\n");
return -EINVAL;
}
if (!pdata->gpio_label) {
pr_err("gpio_label required.\n");
return -EINVAL;
}
if (!pdata->regulator_name) {
pr_err("regulator_name required.\n");
return -EINVAL;
}
vreg = kzalloc(sizeof(struct gpio_vreg), GFP_KERNEL);
if (!vreg) {
pr_err("kzalloc failed.\n");
return -ENOMEM;
}
vreg->name = kstrdup(pdata->regulator_name, GFP_KERNEL);
if (!vreg->name) {
pr_err("kzalloc failed.\n");
rc = -ENOMEM;
goto free_vreg;
}
vreg->gpio_label = kstrdup(pdata->gpio_label, GFP_KERNEL);
if (!vreg->gpio_label) {
pr_err("kzalloc failed.\n");
rc = -ENOMEM;
goto free_name;
}
vreg->gpio = pdata->gpio;
vreg->active_low = (pdata->active_low ? 1 : 0);
vreg->gpio_requested = false;
vreg->desc.name = vreg->name;
vreg->desc.id = pdev->id;
vreg->desc.ops = &gpio_vreg_ops;
vreg->desc.type = REGULATOR_VOLTAGE;
vreg->desc.owner = THIS_MODULE;
vreg->rdev = regulator_register(&vreg->desc, &pdev->dev,
&pdata->init_data, vreg, NULL);
if (IS_ERR(vreg->rdev)) {
rc = PTR_ERR(vreg->rdev);
pr_err("%s: regulator_register failed, rc=%d.\n", vreg->name,
rc);
goto free_gpio_label;
}
platform_set_drvdata(pdev, vreg);
pr_info("id=%d, name=%s, gpio=%u, gpio_label=%s\n", pdev->id,
vreg->name, vreg->gpio, vreg->gpio_label);
return rc;
free_gpio_label:
kfree(vreg->gpio_label);
free_name:
kfree(vreg->name);
free_vreg:
kfree(vreg);
return rc;
}
static int __devexit gpio_vreg_remove(struct platform_device *pdev)
{
struct gpio_vreg *vreg = platform_get_drvdata(pdev);
if (vreg->gpio_requested)
gpio_free(vreg->gpio);
regulator_unregister(vreg->rdev);
kfree(vreg->name);
kfree(vreg->gpio_label);
kfree(vreg);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver gpio_vreg_driver = {
.probe = gpio_vreg_probe,
.remove = __devexit_p(gpio_vreg_remove),
.driver = {
.name = GPIO_REGULATOR_DEV_NAME,
.owner = THIS_MODULE,
},
};
static int __init gpio_vreg_init(void)
{
return platform_driver_register(&gpio_vreg_driver);
}
static void __exit gpio_vreg_exit(void)
{
platform_driver_unregister(&gpio_vreg_driver);
}
postcore_initcall(gpio_vreg_init);
module_exit(gpio_vreg_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("GPIO regulator driver");
MODULE_VERSION("1.0");
MODULE_ALIAS("platform:" GPIO_REGULATOR_DEV_NAME);
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