tps65912-i2c.c

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/*
 * tps65912-i2c.c  --  I2C access for TI TPS65912x PMIC
 *
 * Copyright 2011 Texas Instruments Inc.
 *
 * Author: Margarita Olaya Cabrera <[email protected]>
 *
 *  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 driver is based on wm8350 implementation.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tps65912.h>

static int tps65912_i2c_read(struct tps65912 *tps65912, u8 reg,
                  int bytes, void *dest)
{
    struct i2c_client *i2c = tps65912->control_data;
    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 tps65912_i2c_write(struct tps65912 *tps65912, u8 reg,
                   int bytes, void *src)
{
    struct i2c_client *i2c = tps65912->control_data;
    /* we add 1 byte for device register */
    u8 msg[TPS6591X_MAX_REGISTER + 1];
    int ret;

    if (bytes > TPS6591X_MAX_REGISTER)
        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;
}

static int tps65912_i2c_probe(struct i2c_client *i2c,
                const struct i2c_device_id *id)
{
    struct tps65912 *tps65912;

    tps65912 = kzalloc(sizeof(struct tps65912), GFP_KERNEL);
    if (tps65912 == NULL)
        return -ENOMEM;

    i2c_set_clientdata(i2c, tps65912);
    tps65912->dev = &i2c->dev;
    tps65912->control_data = i2c;
    tps65912->read = tps65912_i2c_read;
    tps65912->write = tps65912_i2c_write;

    return tps65912_device_init(tps65912);
}

static int tps65912_i2c_remove(struct i2c_client *i2c)
{
    struct tps65912 *tps65912 = i2c_get_clientdata(i2c);

    tps65912_device_exit(tps65912);

    return 0;
}

static const struct i2c_device_id tps65912_i2c_id[] = {
    {"tps65912", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, tps65912_i2c_id);

static struct i2c_driver tps65912_i2c_driver = {
    .driver = {
           .name = "tps65912",
           .owner = THIS_MODULE,
    },
    .probe = tps65912_i2c_probe,
    .remove = tps65912_i2c_remove,
    .id_table = tps65912_i2c_id,
};

static int __init tps65912_i2c_init(void)
{
    int ret;

    ret = i2c_add_driver(&tps65912_i2c_driver);
    if (ret != 0)
        pr_err("Failed to register TPS65912 I2C driver: %d\n", ret);

    return ret;
}
/* init early so consumer devices can complete system boot */
subsys_initcall(tps65912_i2c_init);

static void __exit tps65912_i2c_exit(void)
{
    i2c_del_driver(&tps65912_i2c_driver);
}
module_exit(tps65912_i2c_exit);

MODULE_AUTHOR("Margarita Olaya  <[email protected]>");
MODULE_DESCRIPTION("TPS6591x chip family multi-function driver");
MODULE_LICENSE("GPL");