drivers/mfd/88pm860x-i2c.c

/*
 * I2C driver for Marvell 88PM860x
 *
 * Copyright (C) 2009 Marvell International Ltd.
 * 	Haojian Zhuang <haojian.zhuang@marvell.com>
 *
 * 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/88pm860x.h>

static inline int pm860x_read_device(struct i2c_client *i2c,
				     int reg, int bytes, void *dest)
{
	unsigned char data;
	int ret;

	data = (unsigned char)reg;
	ret = i2c_master_send(i2c, &data, 1);
	if (ret < 0)
		return ret;

	ret = i2c_master_recv(i2c, dest, bytes);
	if (ret < 0)
		return ret;
	return 0;
}

static inline int pm860x_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 pm860x_reg_read(struct i2c_client *i2c, int reg)
{
	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
	unsigned char data;
	int ret;

	mutex_lock(&chip->io_lock);
	ret = pm860x_read_device(i2c, reg, 1, &data);
	mutex_unlock(&chip->io_lock);

	if (ret < 0)
		return ret;
	else
		return (int)data;
}
EXPORT_SYMBOL(pm860x_reg_read);

int pm860x_reg_write(struct i2c_client *i2c, int reg,
		     unsigned char data)
{
	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
	int ret;

	mutex_lock(&chip->io_lock);
	ret = pm860x_write_device(i2c, reg, 1, &data);
	mutex_unlock(&chip->io_lock);

	return ret;
}
EXPORT_SYMBOL(pm860x_reg_write);

int pm860x_bulk_read(struct i2c_client *i2c, int reg,
		     int count, unsigned char *buf)
{
	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
	int ret;

	mutex_lock(&chip->io_lock);
	ret = pm860x_read_device(i2c, reg, count, buf);
	mutex_unlock(&chip->io_lock);

	return ret;
}
EXPORT_SYMBOL(pm860x_bulk_read);

int pm860x_bulk_write(struct i2c_client *i2c, int reg,
		      int count, unsigned char *buf)
{
	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
	int ret;

	mutex_lock(&chip->io_lock);
	ret = pm860x_write_device(i2c, reg, count, buf);
	mutex_unlock(&chip->io_lock);

	return ret;
}
EXPORT_SYMBOL(pm860x_bulk_write);

int pm860x_set_bits(struct i2c_client *i2c, int reg,
		    unsigned char mask, unsigned char data)
{
	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
	unsigned char value;
	int ret;

	mutex_lock(&chip->io_lock);
	ret = pm860x_read_device(i2c, reg, 1, &value);
	if (ret < 0)
		goto out;
	value &= ~mask;
	value |= data;
	ret = pm860x_write_device(i2c, reg, 1, &value);
out:
	mutex_unlock(&chip->io_lock);
	return ret;
}
EXPORT_SYMBOL(pm860x_set_bits);


static const struct i2c_device_id pm860x_id_table[] = {
	{ "88PM860x", 0 },
	{}
};
MODULE_DEVICE_TABLE(i2c, pm860x_id_table);

static int verify_addr(struct i2c_client *i2c)
{
	unsigned short addr_8607[] = {0x30, 0x34};
	unsigned short addr_8606[] = {0x10, 0x11};
	int size, i;

	if (i2c == NULL)
		return 0;
	size = ARRAY_SIZE(addr_8606);
	for (i = 0; i < size; i++) {
		if (i2c->addr == *(addr_8606 + i))
			return CHIP_PM8606;
	}
	size = ARRAY_SIZE(addr_8607);
	for (i = 0; i < size; i++) {
		if (i2c->addr == *(addr_8607 + i))
			return CHIP_PM8607;
	}
	return 0;
}

static int __devinit pm860x_probe(struct i2c_client *client,
				  const struct i2c_device_id *id)
{
	struct pm860x_platform_data *pdata = client->dev.platform_data;
	static struct pm860x_chip *chip;
	struct i2c_board_info i2c_info = {
		.type		= "88PM860x",
		.platform_data	= client->dev.platform_data,
	};
	int addr_c, found_companion = 0;

	if (pdata == NULL) {
		pr_info("No platform data in %s!\n", __func__);
		return -EINVAL;
	}

	/*
	 * Both client and companion client shares same platform driver.
	 * Driver distinguishes them by pdata->companion_addr.
	 * pdata->companion_addr is only assigned if companion chip exists.
	 * At the same time, the companion_addr shouldn't equal to client
	 * address.
	 */
	addr_c = pdata->companion_addr;
	if (addr_c && (addr_c != client->addr)) {
		i2c_info.addr = addr_c;
		found_companion = 1;
	}

	if (found_companion || (addr_c == 0)) {
		chip = kzalloc(sizeof(struct pm860x_chip), GFP_KERNEL);
		if (chip == NULL)
			return -ENOMEM;

		chip->id = verify_addr(client);
		chip->companion_addr = addr_c;
		chip->client = client;
		i2c_set_clientdata(client, chip);
		chip->dev = &client->dev;
		mutex_init(&chip->io_lock);
		dev_set_drvdata(chip->dev, chip);

		if (found_companion) {
			/*
			 * If this driver is built in, probe function is
			 * recursive.
			 * If this driver is built as module, the next probe
			 * function is called after the first one finished.
			 */
			chip->companion = i2c_new_device(client->adapter,
							 &i2c_info);
		}
	}

	/*
	 * If companion chip existes, it's called by companion probe.
	 * If there's no companion chip, it's called by client probe.
	 */
	if ((addr_c == 0) || (addr_c == client->addr)) {
		chip->companion = client;
		i2c_set_clientdata(chip->companion, chip);
		pm860x_device_init(chip, pdata);
	}
	return 0;
}

static int __devexit pm860x_remove(struct i2c_client *client)
{
	struct pm860x_chip *chip = i2c_get_clientdata(client);

	/*
	 * If companion existes, companion client is removed first.
	 * Because companion client is registered last and removed first.
	 */
	if (chip->companion_addr == client->addr)
		return 0;
	pm860x_device_exit(chip);
	i2c_unregister_device(chip->companion);
	i2c_set_clientdata(chip->companion, NULL);
	i2c_set_clientdata(chip->client, NULL);
	kfree(chip);
	return 0;
}

static struct i2c_driver pm860x_driver = {
	.driver	= {
		.name	= "88PM860x",
		.owner	= THIS_MODULE,
	},
	.probe		= pm860x_probe,
	.remove		= __devexit_p(pm860x_remove),
	.id_table	= pm860x_id_table,
};

static int __init pm860x_i2c_init(void)
{
	int ret;
	ret = i2c_add_driver(&pm860x_driver);
	if (ret != 0)
		pr_err("Failed to register 88PM860x I2C driver: %d\n", ret);
	return ret;
}
subsys_initcall(pm860x_i2c_init);

static void __exit pm860x_i2c_exit(void)
{
	i2c_del_driver(&pm860x_driver);
}
module_exit(pm860x_i2c_exit);

MODULE_DESCRIPTION("I2C Driver for Marvell 88PM860x");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");