/*
   * Core driver for TPS61050/61052 boost converters, used for while LED
   * driving, audio power amplification, white LED flash, and generic
   * boost conversion. Additionally it provides a 1-bit GPIO pin (out or in)
   * and a flash synchronization pin to synchronize flash events when used as
   * flashgun.
   *
   * Copyright (C) 2011 ST-Ericsson SA
   * Written on behalf of Linaro for ST-Ericsson
   *
   * Author: Linus Walleij <linus.walleij@linaro.org>
   *
   * License terms: GNU General Public License (GPL) version 2
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/i2c.h>
  #include <linux/mutex.h>
  #include <linux/gpio.h>
  #include <linux/spinlock.h>
  #include <linux/slab.h>
  #include <linux/err.h>
  #include <linux/regulator/driver.h>
  #include <linux/mfd/core.h>
  #include <linux/mfd/tps6105x.h>
  
  int tps6105x_set(struct tps6105x *tps6105x, u8 reg, u8 value)
  {
  	int ret;
  
  	ret = mutex_lock_interruptible(&tps6105x->lock);
  	if (ret)
  		return ret;
  	ret = i2c_smbus_write_byte_data(tps6105x->client, reg, value);
  	mutex_unlock(&tps6105x->lock);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  EXPORT_SYMBOL(tps6105x_set);
  
  int tps6105x_get(struct tps6105x *tps6105x, u8 reg, u8 *buf)
  {
  	int ret;
  
  	ret = mutex_lock_interruptible(&tps6105x->lock);
  	if (ret)
  		return ret;
  	ret = i2c_smbus_read_byte_data(tps6105x->client, reg);
  	mutex_unlock(&tps6105x->lock);
  	if (ret < 0)
  		return ret;
  
  	*buf = ret;
  	return 0;
  }
  EXPORT_SYMBOL(tps6105x_get);
  
  /*
   * Masks off the bits in the mask and sets the bits in the bitvalues
   * parameter in one atomic operation
   */
  int tps6105x_mask_and_set(struct tps6105x *tps6105x, u8 reg,
  			  u8 bitmask, u8 bitvalues)
  {
  	int ret;
  	u8 regval;
  
  	ret = mutex_lock_interruptible(&tps6105x->lock);
  	if (ret)
  		return ret;
  	ret = i2c_smbus_read_byte_data(tps6105x->client, reg);
  	if (ret < 0)
  		goto fail;
  	regval = ret;
  	regval = (~bitmask & regval) | (bitmask & bitvalues);
  	ret = i2c_smbus_write_byte_data(tps6105x->client, reg, regval);
  fail:
  	mutex_unlock(&tps6105x->lock);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  EXPORT_SYMBOL(tps6105x_mask_and_set);
  
  static int tps6105x_startup(struct tps6105x *tps6105x)
  {
  	int ret;
  	u8 regval;
  
  	ret = tps6105x_get(tps6105x, TPS6105X_REG_0, &regval);
  	if (ret)
  		return ret;
  	switch (regval >> TPS6105X_REG0_MODE_SHIFT) {
  	case TPS6105X_REG0_MODE_SHUTDOWN:
  		dev_info(&tps6105x->client->dev,
  			 "TPS6105x found in SHUTDOWN mode
  ");
  		break;
  	case TPS6105X_REG0_MODE_TORCH:
  		dev_info(&tps6105x->client->dev,
  			 "TPS6105x found in TORCH mode
  ");
  		break;
  	case TPS6105X_REG0_MODE_TORCH_FLASH:
  		dev_info(&tps6105x->client->dev,
  			 "TPS6105x found in FLASH mode
  ");
  		break;
  	case TPS6105X_REG0_MODE_VOLTAGE:
  		dev_info(&tps6105x->client->dev,
  			 "TPS6105x found in VOLTAGE mode
  ");
  		break;
  	default:
  		break;
  	}
  
  	return ret;
  }
  
  /*
   * MFD cells - we have one cell which is selected operation
   * mode, and we always have a GPIO cell.
   */
  static struct mfd_cell tps6105x_cells[] = {
  	{
  		/* name will be runtime assigned */
  		.id = -1,
  	},
  	{
  		.name = "tps6105x-gpio",
  		.id = -1,
  	},
  };
  
  static int tps6105x_probe(struct i2c_client *client,
  			const struct i2c_device_id *id)
  {
  	struct tps6105x			*tps6105x;
  	struct tps6105x_platform_data	*pdata;
  	int ret;
  	int i;
  
  	tps6105x = kmalloc(sizeof(*tps6105x), GFP_KERNEL);
  	if (!tps6105x)
  		return -ENOMEM;
  
  	i2c_set_clientdata(client, tps6105x);
  	tps6105x->client = client;
  	pdata = dev_get_platdata(&client->dev);
  	tps6105x->pdata = pdata;
  	mutex_init(&tps6105x->lock);
  
  	ret = tps6105x_startup(tps6105x);
  	if (ret) {
  		dev_err(&client->dev, "chip initialization failed
  ");
  		goto fail;
  	}
  
  	/* Remove warning texts when you implement new cell drivers */
  	switch (pdata->mode) {
  	case TPS6105X_MODE_SHUTDOWN:
  		dev_info(&client->dev,
  			 "present, not used for anything, only GPIO
  ");
  		break;
  	case TPS6105X_MODE_TORCH:
  		tps6105x_cells[0].name = "tps6105x-leds";
  		dev_warn(&client->dev,
  			 "torch mode is unsupported
  ");
  		break;
  	case TPS6105X_MODE_TORCH_FLASH:
  		tps6105x_cells[0].name = "tps6105x-flash";
  		dev_warn(&client->dev,
  			 "flash mode is unsupported
  ");
  		break;
  	case TPS6105X_MODE_VOLTAGE:
  		tps6105x_cells[0].name ="tps6105x-regulator";
  		break;
  	default:
  		break;
  	}
  
  	/* Set up and register the platform devices. */
  	for (i = 0; i < ARRAY_SIZE(tps6105x_cells); i++) {
  		/* One state holder for all drivers, this is simple */
  		tps6105x_cells[i].platform_data = tps6105x;
  		tps6105x_cells[i].pdata_size = sizeof(*tps6105x);
  	}
  
  	ret = mfd_add_devices(&client->dev, 0, tps6105x_cells,
  			      ARRAY_SIZE(tps6105x_cells), NULL, 0, NULL);
  	if (ret)
  		goto fail;
  
  	return 0;
  
  fail:
  	kfree(tps6105x);
  	return ret;
  }
  
  static int tps6105x_remove(struct i2c_client *client)
  {
  	struct tps6105x *tps6105x = i2c_get_clientdata(client);
  
  	mfd_remove_devices(&client->dev);
  
  	/* Put chip in shutdown mode */
  	tps6105x_mask_and_set(tps6105x, TPS6105X_REG_0,
  		TPS6105X_REG0_MODE_MASK,
  		TPS6105X_MODE_SHUTDOWN << TPS6105X_REG0_MODE_SHIFT);
  
  	kfree(tps6105x);
  	return 0;
  }
  
  static const struct i2c_device_id tps6105x_id[] = {
  	{ "tps61050", 0 },
  	{ "tps61052", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, tps6105x_id);
  
  static struct i2c_driver tps6105x_driver = {
  	.driver = {
  		.name	= "tps6105x",
  	},
  	.probe		= tps6105x_probe,
  	.remove		= tps6105x_remove,
  	.id_table	= tps6105x_id,
  };
  
  static int __init tps6105x_init(void)
  {
  	return i2c_add_driver(&tps6105x_driver);
  }
  subsys_initcall(tps6105x_init);
  
  static void __exit tps6105x_exit(void)
  {
  	i2c_del_driver(&tps6105x_driver);
  }
  module_exit(tps6105x_exit);
  
  MODULE_AUTHOR("Linus Walleij");
  MODULE_DESCRIPTION("TPS6105x White LED Boost Converter Driver");
  MODULE_LICENSE("GPL v2");