236 lines
6.0 KiB
C
236 lines
6.0 KiB
C
/*
|
|
* 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/platform_device.h>
|
|
#include <linux/regulator/driver.h>
|
|
#include <linux/regulator/fixed.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/delay.h>
|
|
|
|
struct fixed_voltage_data {
|
|
struct regulator_desc desc;
|
|
struct regulator_dev *dev;
|
|
int microvolts;
|
|
int gpio;
|
|
unsigned startup_delay;
|
|
unsigned enable_high:1;
|
|
unsigned is_enabled:1;
|
|
};
|
|
|
|
static int fixed_voltage_is_enabled(struct regulator_dev *dev)
|
|
{
|
|
struct fixed_voltage_data *data = rdev_get_drvdata(dev);
|
|
|
|
return data->is_enabled;
|
|
}
|
|
|
|
static int fixed_voltage_enable(struct regulator_dev *dev)
|
|
{
|
|
struct fixed_voltage_data *data = rdev_get_drvdata(dev);
|
|
|
|
if (gpio_is_valid(data->gpio)) {
|
|
gpio_set_value_cansleep(data->gpio, data->enable_high);
|
|
data->is_enabled = 1;
|
|
if (data->startup_delay)
|
|
udelay(data->startup_delay);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fixed_voltage_disable(struct regulator_dev *dev)
|
|
{
|
|
struct fixed_voltage_data *data = rdev_get_drvdata(dev);
|
|
|
|
if (gpio_is_valid(data->gpio)) {
|
|
gpio_set_value_cansleep(data->gpio, !data->enable_high);
|
|
data->is_enabled = 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fixed_voltage_get_voltage(struct regulator_dev *dev)
|
|
{
|
|
struct fixed_voltage_data *data = rdev_get_drvdata(dev);
|
|
|
|
return data->microvolts;
|
|
}
|
|
|
|
static int fixed_voltage_list_voltage(struct regulator_dev *dev,
|
|
unsigned selector)
|
|
{
|
|
struct fixed_voltage_data *data = rdev_get_drvdata(dev);
|
|
|
|
if (selector != 0)
|
|
return -EINVAL;
|
|
|
|
return data->microvolts;
|
|
}
|
|
|
|
static struct regulator_ops fixed_voltage_ops = {
|
|
.is_enabled = fixed_voltage_is_enabled,
|
|
.enable = fixed_voltage_enable,
|
|
.disable = fixed_voltage_disable,
|
|
.get_voltage = fixed_voltage_get_voltage,
|
|
.list_voltage = fixed_voltage_list_voltage,
|
|
};
|
|
|
|
static int regulator_fixed_voltage_probe(struct platform_device *pdev)
|
|
{
|
|
struct fixed_voltage_config *config = pdev->dev.platform_data;
|
|
struct fixed_voltage_data *drvdata;
|
|
int ret;
|
|
|
|
drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
|
|
if (drvdata == NULL) {
|
|
dev_err(&pdev->dev, "Failed to allocate device data\n");
|
|
ret = -ENOMEM;
|
|
goto err;
|
|
}
|
|
|
|
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->desc.type = REGULATOR_VOLTAGE;
|
|
drvdata->desc.owner = THIS_MODULE;
|
|
drvdata->desc.ops = &fixed_voltage_ops;
|
|
drvdata->desc.n_voltages = 1;
|
|
|
|
drvdata->microvolts = config->microvolts;
|
|
drvdata->gpio = config->gpio;
|
|
drvdata->startup_delay = config->startup_delay;
|
|
|
|
if (gpio_is_valid(config->gpio)) {
|
|
drvdata->enable_high = config->enable_high;
|
|
|
|
/* FIXME: Remove below print warning
|
|
*
|
|
* config->gpio must be set to -EINVAL by platform code if
|
|
* GPIO control is not required. However, early adopters
|
|
* not requiring GPIO control may forget to initialize
|
|
* config->gpio to -EINVAL. This will cause GPIO 0 to be used
|
|
* for GPIO control.
|
|
*
|
|
* This warning will be removed once there are a couple of users
|
|
* for this driver.
|
|
*/
|
|
if (!config->gpio)
|
|
dev_warn(&pdev->dev,
|
|
"using GPIO 0 for regulator enable control\n");
|
|
|
|
ret = gpio_request(config->gpio, config->supply_name);
|
|
if (ret) {
|
|
dev_err(&pdev->dev,
|
|
"Could not obtain regulator enable GPIO %d: %d\n",
|
|
config->gpio, ret);
|
|
goto err_name;
|
|
}
|
|
|
|
/* set output direction without changing state
|
|
* to prevent glitch
|
|
*/
|
|
drvdata->is_enabled = config->enabled_at_boot;
|
|
ret = drvdata->is_enabled ?
|
|
config->enable_high : !config->enable_high;
|
|
|
|
ret = gpio_direction_output(config->gpio, ret);
|
|
if (ret) {
|
|
dev_err(&pdev->dev,
|
|
"Could not configure regulator enable GPIO %d direction: %d\n",
|
|
config->gpio, ret);
|
|
goto err_gpio;
|
|
}
|
|
|
|
} else {
|
|
/* Regulator without GPIO control is considered
|
|
* always enabled
|
|
*/
|
|
drvdata->is_enabled = 1;
|
|
}
|
|
|
|
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_gpio;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, drvdata);
|
|
|
|
dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
|
|
drvdata->microvolts);
|
|
|
|
return 0;
|
|
|
|
err_gpio:
|
|
if (gpio_is_valid(config->gpio))
|
|
gpio_free(config->gpio);
|
|
err_name:
|
|
kfree(drvdata->desc.name);
|
|
err:
|
|
kfree(drvdata);
|
|
return ret;
|
|
}
|
|
|
|
static int regulator_fixed_voltage_remove(struct platform_device *pdev)
|
|
{
|
|
struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
|
|
|
|
regulator_unregister(drvdata->dev);
|
|
if (gpio_is_valid(drvdata->gpio))
|
|
gpio_free(drvdata->gpio);
|
|
kfree(drvdata->desc.name);
|
|
kfree(drvdata);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver regulator_fixed_voltage_driver = {
|
|
.probe = regulator_fixed_voltage_probe,
|
|
.remove = regulator_fixed_voltage_remove,
|
|
.driver = {
|
|
.name = "reg-fixed-voltage",
|
|
},
|
|
};
|
|
|
|
static int __init regulator_fixed_voltage_init(void)
|
|
{
|
|
return platform_driver_register(®ulator_fixed_voltage_driver);
|
|
}
|
|
subsys_initcall(regulator_fixed_voltage_init);
|
|
|
|
static void __exit regulator_fixed_voltage_exit(void)
|
|
{
|
|
platform_driver_unregister(®ulator_fixed_voltage_driver);
|
|
}
|
|
module_exit(regulator_fixed_voltage_exit);
|
|
|
|
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
|
|
MODULE_DESCRIPTION("Fixed voltage regulator");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:reg-fixed-voltage");
|