drivers/mfd/tps65910.c

/*
 * tps65910.c  --  TI TPS6591x
 *
 * Copyright 2010 Texas Instruments Inc.
 *
 * Author: Graeme Gregory <gg@slimlogic.co.uk>
 * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
 *
 *  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/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tps65910.h>

static struct mfd_cell tps65910s[] = {
	{
		.name = "tps65910-pmic",
	},
	{
		.name = "tps65910-rtc",
	},
	{
		.name = "tps65910-power",
	},
};


static int tps65910_i2c_read(struct tps65910 *tps65910, u8 reg,
				  int bytes, void *dest)
{
	struct i2c_client *i2c = tps65910->i2c_client;
	struct i2c_msg xfer[2];
	int ret;

	/* Write register */
	xfer[0].addr = i2c->addr;
	xfer[0].flags = 0;
	xfer[0].len = 1;
	xfer[0].buf = &reg;

	/* Read data */
	xfer[1].addr = i2c->addr;
	xfer[1].flags = I2C_M_RD;
	xfer[1].len = bytes;
	xfer[1].buf = dest;

	ret = i2c_transfer(i2c->adapter, xfer, 2);
	if (ret == 2)
		ret = 0;
	else if (ret >= 0)
		ret = -EIO;

	return ret;
}

static int tps65910_i2c_write(struct tps65910 *tps65910, u8 reg,
				   int bytes, void *src)
{
	struct i2c_client *i2c = tps65910->i2c_client;
	/* we add 1 byte for device register */
	u8 msg[TPS65910_MAX_REGISTER + 1];
	int ret;

	if (bytes > (TPS65910_MAX_REGISTER + 1))
		return -EINVAL;

	msg[0] = reg;
	memcpy(&msg[1], src, bytes);

	ret = i2c_master_send(i2c, msg, bytes + 1);
	if (ret < 0)
		return ret;
	if (ret != bytes + 1)
		return -EIO;
	return 0;
}

int tps65910_set_bits(struct tps65910 *tps65910, u8 reg, u8 mask)
{
	u8 data;
	int err;

	mutex_lock(&tps65910->io_mutex);
	err = tps65910_i2c_read(tps65910, reg, 1, &data);
	if (err) {
		dev_err(tps65910->dev, "read from reg %x failed\n", reg);
		goto out;
	}

	data |= mask;
	err = tps65910_i2c_write(tps65910, reg, 1, &data);
	if (err)
		dev_err(tps65910->dev, "write to reg %x failed\n", reg);

out:
	mutex_unlock(&tps65910->io_mutex);
	return err;
}
EXPORT_SYMBOL_GPL(tps65910_set_bits);

int tps65910_clear_bits(struct tps65910 *tps65910, u8 reg, u8 mask)
{
	u8 data;
	int err;

	mutex_lock(&tps65910->io_mutex);
	err = tps65910_i2c_read(tps65910, reg, 1, &data);
	if (err) {
		dev_err(tps65910->dev, "read from reg %x failed\n", reg);
		goto out;
	}

	data &= mask;
	err = tps65910_i2c_write(tps65910, reg, 1, &data);
	if (err)
		dev_err(tps65910->dev, "write to reg %x failed\n", reg);

out:
	mutex_unlock(&tps65910->io_mutex);
	return err;
}
EXPORT_SYMBOL_GPL(tps65910_clear_bits);

static int tps65910_i2c_probe(struct i2c_client *i2c,
			    const struct i2c_device_id *id)
{
	struct tps65910 *tps65910;
	int ret = 0;

	tps65910 = kzalloc(sizeof(struct tps65910), GFP_KERNEL);
	if (tps65910 == NULL)
		return -ENOMEM;

	i2c_set_clientdata(i2c, tps65910);
	tps65910->dev = &i2c->dev;
	tps65910->i2c_client = i2c;
	tps65910->read = tps65910_i2c_read;
	tps65910->write = tps65910_i2c_write;
	mutex_init(&tps65910->io_mutex);

	ret = mfd_add_devices(tps65910->dev, -1,
			      tps65910s, ARRAY_SIZE(tps65910s),
			      NULL, 0);
	if (ret < 0)
		goto err;

	return ret;

err:
	mfd_remove_devices(tps65910->dev);
	kfree(tps65910);
	return ret;
}

static int tps65910_i2c_remove(struct i2c_client *i2c)
{
	struct tps65910 *tps65910 = i2c_get_clientdata(i2c);

	mfd_remove_devices(tps65910->dev);
	kfree(tps65910);

	return 0;
}

static const struct i2c_device_id tps65910_i2c_id[] = {
       { "tps65910", 0 },
       { }
};
MODULE_DEVICE_TABLE(i2c, tps65910_i2c_id);


static struct i2c_driver tps65910_i2c_driver = {
	.driver = {
		   .name = "tps65910",
		   .owner = THIS_MODULE,
	},
	.probe = tps65910_i2c_probe,
	.remove = tps65910_i2c_remove,
	.id_table = tps65910_i2c_id,
};

static int __init tps65910_i2c_init(void)
{
	return i2c_add_driver(&tps65910_i2c_driver);
}
/* init early so consumer devices can complete system boot */
subsys_initcall(tps65910_i2c_init);

static void __exit tps65910_i2c_exit(void)
{
	i2c_del_driver(&tps65910_i2c_driver);
}
module_exit(tps65910_i2c_exit);

MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
MODULE_DESCRIPTION("TPS6591x chip family multi-function driver");
MODULE_LICENSE("GPL");