tps6507x.c

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/*
 * tps6507x.c  --  TPS6507x chip family multi-function driver
 *
 *  Copyright (c) 2010 RidgeRun ([email protected])
 *
 * Author: Todd Fischer
 *         [email protected]
 *
 * Credits:
 *
 *    Using code from wm831x-*.c, wm8400-core, Wolfson Microelectronics PLC.
 *
 * For licencing details see kernel-base/COPYING
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tps6507x.h>

static struct mfd_cell tps6507x_devs[] = {
    {
        .name = "tps6507x-pmic",
    },
    {
        .name = "tps6507x-ts",
    },
};


static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
                  int bytes, void *dest)
{
    struct i2c_client *i2c = tps6507x->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 tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
                   int bytes, void *src)
{
    struct i2c_client *i2c = tps6507x->i2c_client;
    /* we add 1 byte for device register */
    u8 msg[TPS6507X_MAX_REGISTER + 1];
    int ret;

    if (bytes > TPS6507X_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 tps6507x_i2c_probe(struct i2c_client *i2c,
                const struct i2c_device_id *id)
{
    struct tps6507x_dev *tps6507x;
    int ret = 0;

    tps6507x = kzalloc(sizeof(struct tps6507x_dev), GFP_KERNEL);
    if (tps6507x == NULL)
        return -ENOMEM;

    i2c_set_clientdata(i2c, tps6507x);
    tps6507x->dev = &i2c->dev;
    tps6507x->i2c_client = i2c;
    tps6507x->read_dev = tps6507x_i2c_read_device;
    tps6507x->write_dev = tps6507x_i2c_write_device;

    ret = mfd_add_devices(tps6507x->dev, -1,
                  tps6507x_devs, ARRAY_SIZE(tps6507x_devs),
                  NULL, 0, NULL);

    if (ret < 0)
        goto err;

    return ret;

err:
    mfd_remove_devices(tps6507x->dev);
    kfree(tps6507x);
    return ret;
}

static int tps6507x_i2c_remove(struct i2c_client *i2c)
{
    struct tps6507x_dev *tps6507x = i2c_get_clientdata(i2c);

    mfd_remove_devices(tps6507x->dev);
    kfree(tps6507x);

    return 0;
}

static const struct i2c_device_id tps6507x_i2c_id[] = {
       { "tps6507x", 0 },
       { }
};
MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);


static struct i2c_driver tps6507x_i2c_driver = {
    .driver = {
           .name = "tps6507x",
           .owner = THIS_MODULE,
    },
    .probe = tps6507x_i2c_probe,
    .remove = tps6507x_i2c_remove,
    .id_table = tps6507x_i2c_id,
};

static int __init tps6507x_i2c_init(void)
{
    return i2c_add_driver(&tps6507x_i2c_driver);
}
/* init early so consumer devices can complete system boot */
subsys_initcall(tps6507x_i2c_init);

static void __exit tps6507x_i2c_exit(void)
{
    i2c_del_driver(&tps6507x_i2c_driver);
}
module_exit(tps6507x_i2c_exit);

MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
MODULE_LICENSE("GPL");