linux-sg2042/drivers/mfd/max8998.c

159 lines
3.9 KiB
C

/*
* max8698.c - mfd core driver for the Maxim 8998
*
* Copyright (C) 2009-2010 Samsung Electronics
* Kyungmin Park <kyungmin.park@samsung.com>
* Marek Szyprowski <m.szyprowski@samsung.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 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/mfd/core.h>
#include <linux/mfd/max8998.h>
#include <linux/mfd/max8998-private.h>
static struct mfd_cell max8998_devs[] = {
{
.name = "max8998-pmic",
}
};
static int max8998_i2c_device_read(struct max8998_dev *max8998, u8 reg, u8 *dest)
{
struct i2c_client *client = max8998->i2c_client;
int ret;
mutex_lock(&max8998->iolock);
ret = i2c_smbus_read_byte_data(client, reg);
mutex_unlock(&max8998->iolock);
if (ret < 0)
return ret;
ret &= 0xff;
*dest = ret;
return 0;
}
static int max8998_i2c_device_write(struct max8998_dev *max8998, u8 reg, u8 value)
{
struct i2c_client *client = max8998->i2c_client;
int ret;
mutex_lock(&max8998->iolock);
ret = i2c_smbus_write_byte_data(client, reg, value);
mutex_unlock(&max8998->iolock);
return ret;
}
static int max8998_i2c_device_update(struct max8998_dev *max8998, u8 reg,
u8 val, u8 mask)
{
struct i2c_client *client = max8998->i2c_client;
int ret;
mutex_lock(&max8998->iolock);
ret = i2c_smbus_read_byte_data(client, reg);
if (ret >= 0) {
u8 old_val = ret & 0xff;
u8 new_val = (val & mask) | (old_val & (~mask));
ret = i2c_smbus_write_byte_data(client, reg, new_val);
if (ret >= 0)
ret = 0;
}
mutex_unlock(&max8998->iolock);
return ret;
}
static int max8998_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
struct max8998_dev *max8998;
int ret = 0;
max8998 = kzalloc(sizeof(struct max8998_dev), GFP_KERNEL);
if (max8998 == NULL)
return -ENOMEM;
i2c_set_clientdata(i2c, max8998);
max8998->dev = &i2c->dev;
max8998->i2c_client = i2c;
max8998->dev_read = max8998_i2c_device_read;
max8998->dev_write = max8998_i2c_device_write;
max8998->dev_update = max8998_i2c_device_update;
mutex_init(&max8998->iolock);
ret = mfd_add_devices(max8998->dev, -1,
max8998_devs, ARRAY_SIZE(max8998_devs),
NULL, 0);
if (ret < 0)
goto err;
return ret;
err:
mfd_remove_devices(max8998->dev);
kfree(max8998);
return ret;
}
static int max8998_i2c_remove(struct i2c_client *i2c)
{
struct max8998_dev *max8998 = i2c_get_clientdata(i2c);
mfd_remove_devices(max8998->dev);
kfree(max8998);
return 0;
}
static const struct i2c_device_id max8998_i2c_id[] = {
{ "max8998", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, max8998_i2c_id);
static struct i2c_driver max8998_i2c_driver = {
.driver = {
.name = "max8998",
.owner = THIS_MODULE,
},
.probe = max8998_i2c_probe,
.remove = max8998_i2c_remove,
.id_table = max8998_i2c_id,
};
static int __init max8998_i2c_init(void)
{
return i2c_add_driver(&max8998_i2c_driver);
}
/* init early so consumer devices can complete system boot */
subsys_initcall(max8998_i2c_init);
static void __exit max8998_i2c_exit(void)
{
i2c_del_driver(&max8998_i2c_driver);
}
module_exit(max8998_i2c_exit);
MODULE_DESCRIPTION("MAXIM 8998 multi-function core driver");
MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
MODULE_LICENSE("GPL");