max8925-i2c.c

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/*
 * I2C driver for Maxim MAX8925
 *
 * Copyright (C) 2009 Marvell International Ltd.
 *  Haojian Zhuang <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/mfd/max8925.h>
#include <linux/slab.h>

#define RTC_I2C_ADDR        0x68
#define ADC_I2C_ADDR        0x47

static inline int max8925_read_device(struct i2c_client *i2c,
                      int reg, int bytes, void *dest)
{
    int ret;

    if (bytes > 1)
        ret = i2c_smbus_read_i2c_block_data(i2c, reg, bytes, dest);
    else {
        ret = i2c_smbus_read_byte_data(i2c, reg);
        if (ret < 0)
            return ret;
        *(unsigned char *)dest = (unsigned char)ret;
    }
    return ret;
}

static inline int max8925_write_device(struct i2c_client *i2c,
                       int reg, int bytes, void *src)
{
    unsigned char buf[bytes + 1];
    int ret;

    buf[0] = (unsigned char)reg;
    memcpy(&buf[1], src, bytes);

    ret = i2c_master_send(i2c, buf, bytes + 1);
    if (ret < 0)
        return ret;
    return 0;
}

int max8925_reg_read(struct i2c_client *i2c, int reg)
{
    struct max8925_chip *chip = i2c_get_clientdata(i2c);
    unsigned char data = 0;
    int ret;

    mutex_lock(&chip->io_lock);
    ret = max8925_read_device(i2c, reg, 1, &data);
    mutex_unlock(&chip->io_lock);

    if (ret < 0)
        return ret;
    else
        return (int)data;
}
EXPORT_SYMBOL(max8925_reg_read);

int max8925_reg_write(struct i2c_client *i2c, int reg,
        unsigned char data)
{
    struct max8925_chip *chip = i2c_get_clientdata(i2c);
    int ret;

    mutex_lock(&chip->io_lock);
    ret = max8925_write_device(i2c, reg, 1, &data);
    mutex_unlock(&chip->io_lock);

    return ret;
}
EXPORT_SYMBOL(max8925_reg_write);

int max8925_bulk_read(struct i2c_client *i2c, int reg,
        int count, unsigned char *buf)
{
    struct max8925_chip *chip = i2c_get_clientdata(i2c);
    int ret;

    mutex_lock(&chip->io_lock);
    ret = max8925_read_device(i2c, reg, count, buf);
    mutex_unlock(&chip->io_lock);

    return ret;
}
EXPORT_SYMBOL(max8925_bulk_read);

int max8925_bulk_write(struct i2c_client *i2c, int reg,
        int count, unsigned char *buf)
{
    struct max8925_chip *chip = i2c_get_clientdata(i2c);
    int ret;

    mutex_lock(&chip->io_lock);
    ret = max8925_write_device(i2c, reg, count, buf);
    mutex_unlock(&chip->io_lock);

    return ret;
}
EXPORT_SYMBOL(max8925_bulk_write);

int max8925_set_bits(struct i2c_client *i2c, int reg,
        unsigned char mask, unsigned char data)
{
    struct max8925_chip *chip = i2c_get_clientdata(i2c);
    unsigned char value;
    int ret;

    mutex_lock(&chip->io_lock);
    ret = max8925_read_device(i2c, reg, 1, &value);
    if (ret < 0)
        goto out;
    value &= ~mask;
    value |= data;
    ret = max8925_write_device(i2c, reg, 1, &value);
out:
    mutex_unlock(&chip->io_lock);
    return ret;
}
EXPORT_SYMBOL(max8925_set_bits);


static const struct i2c_device_id max8925_id_table[] = {
    { "max8925", 0 },
    { },
};
MODULE_DEVICE_TABLE(i2c, max8925_id_table);

static int __devinit max8925_probe(struct i2c_client *client,
                   const struct i2c_device_id *id)
{
    struct max8925_platform_data *pdata = client->dev.platform_data;
    static struct max8925_chip *chip;

    if (!pdata) {
        pr_info("%s: platform data is missing\n", __func__);
        return -EINVAL;
    }

    chip = kzalloc(sizeof(struct max8925_chip), GFP_KERNEL);
    if (chip == NULL)
        return -ENOMEM;
    chip->i2c = client;
    chip->dev = &client->dev;
    i2c_set_clientdata(client, chip);
    dev_set_drvdata(chip->dev, chip);
    mutex_init(&chip->io_lock);

    chip->rtc = i2c_new_dummy(chip->i2c->adapter, RTC_I2C_ADDR);
    i2c_set_clientdata(chip->rtc, chip);

    chip->adc = i2c_new_dummy(chip->i2c->adapter, ADC_I2C_ADDR);
    i2c_set_clientdata(chip->adc, chip);

    device_init_wakeup(&client->dev, 1);

    max8925_device_init(chip, pdata);

    return 0;
}

static int __devexit max8925_remove(struct i2c_client *client)
{
    struct max8925_chip *chip = i2c_get_clientdata(client);

    max8925_device_exit(chip);
    i2c_unregister_device(chip->adc);
    i2c_unregister_device(chip->rtc);
    kfree(chip);
    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int max8925_suspend(struct device *dev)
{
    struct i2c_client *client = container_of(dev, struct i2c_client, dev);
    struct max8925_chip *chip = i2c_get_clientdata(client);

    if (device_may_wakeup(dev) && chip->wakeup_flag)
        enable_irq_wake(chip->core_irq);
    return 0;
}

static int max8925_resume(struct device *dev)
{
    struct i2c_client *client = container_of(dev, struct i2c_client, dev);
    struct max8925_chip *chip = i2c_get_clientdata(client);

    if (device_may_wakeup(dev) && chip->wakeup_flag)
        disable_irq_wake(chip->core_irq);
    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(max8925_pm_ops, max8925_suspend, max8925_resume);

static struct i2c_driver max8925_driver = {
    .driver = {
        .name   = "max8925",
        .owner  = THIS_MODULE,
        .pm     = &max8925_pm_ops,
    },
    .probe      = max8925_probe,
    .remove     = __devexit_p(max8925_remove),
    .id_table   = max8925_id_table,
};

static int __init max8925_i2c_init(void)
{
    int ret;

    ret = i2c_add_driver(&max8925_driver);
    if (ret != 0)
        pr_err("Failed to register MAX8925 I2C driver: %d\n", ret);
    return ret;
}
subsys_initcall(max8925_i2c_init);

static void __exit max8925_i2c_exit(void)
{
    i2c_del_driver(&max8925_driver);
}
module_exit(max8925_i2c_exit);

MODULE_DESCRIPTION("I2C Driver for Maxim 8925");
MODULE_AUTHOR("Haojian Zhuang <[email protected]>");
MODULE_LICENSE("GPL");