/*
* gpio-regulator.c
*
* Copyright 2011 Heiko Stuebner <heiko@sntech.de>
*
* based on fixed.c
*
* Copyright 2008 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*
* Copyright (c) 2009 Nokia Corporation
* Roger Quadros <ext-roger.quadros@nokia.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.
*
* This is useful for systems with mixed controllable and
* non-controllable regulators, as well as for allowing testing on
* systems with no controllable regulators.
*/
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/gpio-regulator.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
struct gpio_regulator_data {
struct regulator_desc desc;
struct regulator_dev *dev;
int enable_gpio;
bool enable_high;
bool is_enabled;
unsigned startup_delay;
struct gpio *gpios;
int nr_gpios;
struct gpio_regulator_state *states;
int nr_states;
int state;
};
static int gpio_regulator_is_enabled(struct regulator_dev *dev)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
return data->is_enabled;
}
static int gpio_regulator_enable(struct regulator_dev *dev)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
if (gpio_is_valid(data->enable_gpio)) {
gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
data->is_enabled = true;
}
return 0;
}
static int gpio_regulator_disable(struct regulator_dev *dev)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
if (gpio_is_valid(data->enable_gpio)) {
gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
data->is_enabled = false;
}
return 0;
}
static int gpio_regulator_enable_time(struct regulator_dev *dev)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
return data->startup_delay;
}
static int gpio_regulator_get_value(struct regulator_dev *dev)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
int ptr;
for (ptr = 0; ptr < data->nr_states; ptr++)
if (data->states[ptr].gpios == data->state)
return data->states[ptr].value;
return -EINVAL;
}
static int gpio_regulator_set_value(struct regulator_dev *dev,
int min, int max)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
int ptr, target, state;
target = -1;
for (ptr = 0; ptr < data->nr_states; ptr++)
if (data->states[ptr].value >= min &&
data->states[ptr].value <= max)
target = data->states[ptr].gpios;
if (target < 0)
return -EINVAL;
for (ptr = 0; ptr < data->nr_gpios; ptr++) {
state = (target & (1 << ptr)) >> ptr;
gpio_set_value(data->gpios[ptr].gpio, state);
}
data->state = target;
return 0;
}
static int gpio_regulator_set_voltage(struct regulator_dev *dev,
int min_uV, int max_uV,
unsigned *selector)
{
return gpio_regulator_set_value(dev, min_uV, max_uV);
}
static int gpio_regulator_list_voltage(struct regulator_dev *dev,
unsigned selector)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
if (selector >= data->nr_states)
return -EINVAL;
return data->states[selector].value;
}
static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
int min_uA, int max_uA)
{
return gpio_regulator_set_value(dev, min_uA, max_uA);
}
static struct regulator_ops gpio_regulator_voltage_ops = {
.is_enabled = gpio_regulator_is_enabled,
.enable = gpio_regulator_enable,
.disable = gpio_regulator_disable,
.enable_time = gpio_regulator_enable_time,
.get_voltage = gpio_regulator_get_value,
.set_voltage = gpio_regulator_set_voltage,
.list_voltage = gpio_regulator_list_voltage,
};
static struct regulator_ops gpio_regulator_current_ops = {
.is_enabled = gpio_regulator_is_enabled,
.enable = gpio_regulator_enable,
.disable = gpio_regulator_disable,
.enable_time = gpio_regulator_enable_time,
.get_current_limit = gpio_regulator_get_value,
.set_current_limit = gpio_regulator_set_current_limit,
};
static int __devinit gpio_regulator_probe(struct platform_device *pdev)
{
struct gpio_regulator_config *config = pdev->dev.platform_data;
struct gpio_regulator_data *drvdata;
int ptr, ret, state;
drvdata = kzalloc(sizeof(struct gpio_regulator_data), GFP_KERNEL);
if (drvdata == NULL) {
dev_err(&pdev->dev, "Failed to allocate device data\n");
return -ENOMEM;
}
drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
if (drvdata->desc.name == NULL) {
dev_err(&pdev->dev, "Failed to allocate supply name\n");
ret = -ENOMEM;
goto err;
}
drvdata->gpios = kmemdup(config->gpios,
config->nr_gpios * sizeof(struct gpio),
GFP_KERNEL);
if (drvdata->gpios == NULL) {
dev_err(&pdev->dev, "Failed to allocate gpio data\n");
ret = -ENOMEM;
goto err_name;
}
drvdata->states = kmemdup(config->states,
config->nr_states *
sizeof(struct gpio_regulator_state),
GFP_KERNEL);
if (drvdata->states == NULL) {
dev_err(&pdev->dev, "Failed to allocate state data\n");
ret = -ENOMEM;
goto err_memgpio;
}
drvdata->nr_states = config->nr_states;
drvdata->desc.owner = THIS_MODULE;
/* handle regulator type*/
switch (config->type) {
case REGULATOR_VOLTAGE:
drvdata->desc.type = REGULATOR_VOLTAGE;
drvdata->desc.ops = &gpio_regulator_voltage_ops;
drvdata->desc.n_voltages = config->nr_states;
break;
case REGULATOR_CURRENT:
drvdata->desc.type = REGULATOR_CURRENT;
drvdata->desc.ops = &gpio_regulator_current_ops;
break;
default:
dev_err(&pdev->dev, "No regulator type set\n");
ret = -EINVAL;
goto err_memgpio;
break;
}
drvdata->enable_gpio = config->enable_gpio;
drvdata->startup_delay = config->startup_delay;
if (gpio_is_valid(config->enable_gpio)) {
drvdata->enable_high = config->enable_high;
ret = gpio_request(config->enable_gpio, config->supply_name);
if (ret) {
dev_err(&pdev->dev,
"Could not obtain regulator enable GPIO %d: %d\n",
config->enable_gpio, ret);
goto err_memstate;
}
/* set output direction without changing state
* to prevent glitch
*/
if (config->enabled_at_boot) {
drvdata->is_enabled = true;
ret = gpio_direction_output(config->enable_gpio,
config->enable_high);
} else {
drvdata->is_enabled = false;
ret = gpio_direction_output(config->enable_gpio,
!config->enable_high);
}
if (ret) {
dev_err(&pdev->dev,
"Could not configure regulator enable GPIO %d direction: %d\n",
config->enable_gpio, ret);
goto err_enablegpio;
}
} else {
/* Regulator without GPIO control is considered
* always enabled
*/
drvdata->is_enabled = true;
}
drvdata->nr_gpios = config->nr_gpios;
ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
if (ret) {
dev_err(&pdev->dev,
"Could not obtain regulator setting GPIOs: %d\n", ret);
goto err_enablegpio;
}
/* build initial state from gpio init data. */
state = 0;
for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
state |= (1 << ptr);
}
drvdata->state = state;
drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
config->init_data, drvdata);
if (IS_ERR(drvdata->dev)) {
ret = PTR_ERR(drvdata->dev);
dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
goto err_stategpio;
}
platform_set_drvdata(pdev, drvdata);
return 0;
err_stategpio:
gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
err_enablegpio:
if (gpio_is_valid(config->enable_gpio))
gpio_free(config->enable_gpio);
err_memstate:
kfree(drvdata->states);
err_memgpio:
kfree(drvdata->gpios);
err_name:
kfree(drvdata->desc.name);
err:
kfree(drvdata);
return ret;
}
static int __devexit gpio_regulator_remove(struct platform_device *pdev)
{
struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
regulator_unregister(drvdata->dev);
gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
kfree(drvdata->states);
kfree(drvdata->gpios);
if (gpio_is_valid(drvdata->enable_gpio))
gpio_free(drvdata->enable_gpio);
kfree(drvdata->desc.name);
kfree(drvdata);
return 0;
}
static struct platform_driver gpio_regulator_driver = {
.probe = gpio_regulator_probe,
.remove = __devexit_p(gpio_regulator_remove),
.driver = {
.name = "gpio-regulator",
.owner = THIS_MODULE,
},
};
static int __init gpio_regulator_init(void)
{
return platform_driver_register(&gpio_regulator_driver);
}
subsys_initcall(gpio_regulator_init);
static void __exit gpio_regulator_exit(void)
{
platform_driver_unregister(&gpio_regulator_driver);
}
module_exit(gpio_regulator_exit);
MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_DESCRIPTION("gpio voltage regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-regulator");
