/*

   * 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/err.h>
  #include <linux/regmap.h>

  #include <linux/mfd/88pm860x.h>

  #include <linux/slab.h>

  int pm860x_reg_read(struct i2c_client *i2c, int reg)

  {

  	struct pm860x_chip *chip = i2c_get_clientdata(i2c);

  	struct regmap *map = (i2c == chip->client) ? chip->regmap
  				: chip->regmap_companion;
  	unsigned int data;

  	int ret;

  	ret = regmap_read(map, reg, &data);

  	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);

  	struct regmap *map = (i2c == chip->client) ? chip->regmap
  				: chip->regmap_companion;

  	int ret;

  	ret = regmap_write(map, reg, data);

  	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);

  	struct regmap *map = (i2c == chip->client) ? chip->regmap
  				: chip->regmap_companion;

  	int ret;

  	ret = regmap_raw_read(map, reg, buf, count);

  	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);

  	struct regmap *map = (i2c == chip->client) ? chip->regmap
  				: chip->regmap_companion;

  	int ret;

  	ret = regmap_raw_write(map, reg, buf, count);

  	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);

  	struct regmap *map = (i2c == chip->client) ? chip->regmap
  				: chip->regmap_companion;

  	int ret;

  	ret = regmap_update_bits(map, reg, mask, data);

  	return ret;
  }

  EXPORT_SYMBOL(pm860x_set_bits);

  static int read_device(struct i2c_client *i2c, int reg,
  		       int bytes, void *dest)
  {
  	unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX + 3];
  	unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX + 2];
  	struct i2c_adapter *adap = i2c->adapter;
  	struct i2c_msg msg[2] = {{i2c->addr, 0, 1, msgbuf0},
  				 {i2c->addr, I2C_M_RD, 0, msgbuf1},
  				};
  	int num = 1, ret = 0;
  
  	if (dest == NULL)
  		return -EINVAL;
  	msgbuf0[0] = (unsigned char)reg;	/* command */
  	msg[1].len = bytes;
  
  	/* if data needs to read back, num should be 2 */
  	if (bytes > 0)
  		num = 2;
  	ret = adap->algo->master_xfer(adap, msg, num);
  	memcpy(dest, msgbuf1, bytes);
  	if (ret < 0)
  		return ret;
  	return 0;
  }
  
  static int write_device(struct i2c_client *i2c, int reg,
  			int bytes, void *src)
  {
  	unsigned char buf[bytes + 1];
  	struct i2c_adapter *adap = i2c->adapter;
  	struct i2c_msg msg;
  	int ret;
  
  	buf[0] = (unsigned char)reg;
  	memcpy(&buf[1], src, bytes);
  	msg.addr = i2c->addr;
  	msg.flags = 0;
  	msg.len = bytes + 1;
  	msg.buf = buf;
  
  	ret = adap->algo->master_xfer(adap, &msg, 1);
  	if (ret < 0)
  		return ret;
  	return 0;
  }

  int pm860x_page_reg_read(struct i2c_client *i2c, int reg)
  {

  	unsigned char zero = 0;
  	unsigned char data;
  	int ret;

  	i2c_lock_adapter(i2c->adapter);
  	read_device(i2c, 0xFA, 0, &zero);
  	read_device(i2c, 0xFB, 0, &zero);
  	read_device(i2c, 0xFF, 0, &zero);
  	ret = read_device(i2c, reg, 1, &data);

  	if (ret >= 0)
  		ret = (int)data;

  	read_device(i2c, 0xFE, 0, &zero);
  	read_device(i2c, 0xFC, 0, &zero);
  	i2c_unlock_adapter(i2c->adapter);

  	return ret;
  }
  EXPORT_SYMBOL(pm860x_page_reg_read);
  
  int pm860x_page_reg_write(struct i2c_client *i2c, int reg,
  			  unsigned char data)
  {

  	unsigned char zero;
  	int ret;

  	i2c_lock_adapter(i2c->adapter);
  	read_device(i2c, 0xFA, 0, &zero);
  	read_device(i2c, 0xFB, 0, &zero);
  	read_device(i2c, 0xFF, 0, &zero);
  	ret = write_device(i2c, reg, 1, &data);
  	read_device(i2c, 0xFE, 0, &zero);
  	read_device(i2c, 0xFC, 0, &zero);
  	i2c_unlock_adapter(i2c->adapter);

  	return ret;
  }
  EXPORT_SYMBOL(pm860x_page_reg_write);
  
  int pm860x_page_bulk_read(struct i2c_client *i2c, int reg,
  			  int count, unsigned char *buf)
  {

  	unsigned char zero = 0;
  	int ret;

  	i2c_lock_adapter(i2c->adapter);
  	read_device(i2c, 0xfa, 0, &zero);
  	read_device(i2c, 0xfb, 0, &zero);
  	read_device(i2c, 0xff, 0, &zero);
  	ret = read_device(i2c, reg, count, buf);
  	read_device(i2c, 0xFE, 0, &zero);
  	read_device(i2c, 0xFC, 0, &zero);
  	i2c_unlock_adapter(i2c->adapter);

  	return ret;
  }
  EXPORT_SYMBOL(pm860x_page_bulk_read);
  
  int pm860x_page_bulk_write(struct i2c_client *i2c, int reg,
  			   int count, unsigned char *buf)
  {

  	unsigned char zero = 0;
  	int ret;

  	i2c_lock_adapter(i2c->adapter);
  	read_device(i2c, 0xFA, 0, &zero);
  	read_device(i2c, 0xFB, 0, &zero);
  	read_device(i2c, 0xFF, 0, &zero);
  	ret = write_device(i2c, reg, count, buf);
  	read_device(i2c, 0xFE, 0, &zero);
  	read_device(i2c, 0xFC, 0, &zero);
  	i2c_unlock_adapter(i2c->adapter);
  	i2c_unlock_adapter(i2c->adapter);

  	return ret;
  }
  EXPORT_SYMBOL(pm860x_page_bulk_write);
  
  int pm860x_page_set_bits(struct i2c_client *i2c, int reg,
  			 unsigned char mask, unsigned char data)
  {

  	unsigned char zero;
  	unsigned char value;
  	int ret;

  	i2c_lock_adapter(i2c->adapter);
  	read_device(i2c, 0xFA, 0, &zero);
  	read_device(i2c, 0xFB, 0, &zero);
  	read_device(i2c, 0xFF, 0, &zero);
  	ret = read_device(i2c, reg, 1, &value);

  	if (ret < 0)
  		goto out;
  	value &= ~mask;
  	value |= data;

  	ret = write_device(i2c, reg, 1, &value);

  out:

  	read_device(i2c, 0xFE, 0, &zero);
  	read_device(i2c, 0xFC, 0, &zero);
  	i2c_unlock_adapter(i2c->adapter);

  	return ret;
  }
  EXPORT_SYMBOL(pm860x_page_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 struct regmap_config pm860x_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  };

  static int __devinit pm860x_probe(struct i2c_client *client,
  				  const struct i2c_device_id *id)
  {

  	struct pm860x_platform_data *pdata = client->dev.platform_data;

  	struct pm860x_chip *chip;

  	int ret;

  
  	if (!pdata) {

  		pr_info("No platform data in %s!
  ", __func__);
  		return -EINVAL;
  	}

  	chip = kzalloc(sizeof(struct pm860x_chip), GFP_KERNEL);
  	if (chip == NULL)
  		return -ENOMEM;
  
  	chip->id = verify_addr(client);

  	chip->regmap = regmap_init_i2c(client, &pm860x_regmap_config);
  	if (IS_ERR(chip->regmap)) {
  		ret = PTR_ERR(chip->regmap);
  		dev_err(&client->dev, "Failed to allocate register map: %d
  ",
  				ret);

  		kfree(chip);

  		return ret;
  	}

  	chip->client = client;
  	i2c_set_clientdata(client, chip);
  	chip->dev = &client->dev;

  	dev_set_drvdata(chip->dev, chip);

  	/*
  	 * 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.
  	 */

  	if (pdata->companion_addr && (pdata->companion_addr != client->addr)) {
  		chip->companion_addr = pdata->companion_addr;
  		chip->companion = i2c_new_dummy(chip->client->adapter,
  						chip->companion_addr);

  		chip->regmap_companion = regmap_init_i2c(chip->companion,
  							&pm860x_regmap_config);
  		if (IS_ERR(chip->regmap_companion)) {
  			ret = PTR_ERR(chip->regmap_companion);
  			dev_err(&chip->companion->dev,
  				"Failed to allocate register map: %d
  ", ret);
  			return ret;
  		}

  		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);

  	pm860x_device_exit(chip);

  	if (chip->companion) {
  		regmap_exit(chip->regmap_companion);
  		i2c_unregister_device(chip->companion);
  	}
  	regmap_exit(chip->regmap);

  	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
  ", 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");