/*
   * I2C driver for Maxim MAX8925
   *
   * 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/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 max8925_dt_init(struct device_node *np, struct device *dev,
  			   struct max8925_platform_data *pdata)
  {
  	int ret;
  
  	ret = of_property_read_u32(np, "maxim,tsc-irq", &pdata->tsc_irq);
  	if (ret) {
  		dev_err(dev, "Not found maxim,tsc-irq property
  ");
  		return -EINVAL;
  	}
  	return 0;
  }
  
  static int max8925_probe(struct i2c_client *client,
  				   const struct i2c_device_id *id)
  {
  	struct max8925_platform_data *pdata = dev_get_platdata(&client->dev);
  	static struct max8925_chip *chip;
  	struct device_node *node = client->dev.of_node;
  
  	if (node && !pdata) {
  		/* parse DT to get platform data */
  		pdata = devm_kzalloc(&client->dev,
  				     sizeof(struct max8925_platform_data),
  				     GFP_KERNEL);
  		if (!pdata)
  			return -ENOMEM;
  
  		if (max8925_dt_init(node, &client->dev, pdata))
  			return -EINVAL;
  	} else if (!pdata) {
  		pr_info("%s: platform data is missing
  ", __func__);
  		return -EINVAL;
  	}
  
  	chip = devm_kzalloc(&client->dev,
  			    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);
  	if (!chip->rtc) {
  		dev_err(chip->dev, "Failed to allocate I2C device for RTC
  ");
  		return -ENODEV;
  	}
  	i2c_set_clientdata(chip->rtc, chip);
  
  	chip->adc = i2c_new_dummy(chip->i2c->adapter, ADC_I2C_ADDR);
  	if (!chip->adc) {
  		dev_err(chip->dev, "Failed to allocate I2C device for ADC
  ");
  		i2c_unregister_device(chip->rtc);
  		return -ENODEV;
  	}
  	i2c_set_clientdata(chip->adc, chip);
  
  	device_init_wakeup(&client->dev, 1);
  
  	max8925_device_init(chip, pdata);
  
  	return 0;
  }
  
  static int 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);
  	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 const struct of_device_id max8925_dt_ids[] = {
  	{ .compatible = "maxim,max8925", },
  	{},
  };
  MODULE_DEVICE_TABLE(of, max8925_dt_ids);
  
  static struct i2c_driver max8925_driver = {
  	.driver	= {
  		.name	= "max8925",
  		.owner	= THIS_MODULE,
  		.pm     = &max8925_pm_ops,
  		.of_match_table = max8925_dt_ids,
  	},
  	.probe		= max8925_probe,
  	.remove		= 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
  ", 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 <haojian.zhuang@marvell.com>");
  MODULE_LICENSE("GPL");