/*
   * Copyright (C) ST-Ericsson SA 2010
   *
   * License Terms: GNU General Public License, version 2
   * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
   * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
   */
  
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/slab.h>
  #include <linux/i2c.h>
  #include <linux/mfd/core.h>

  #include <linux/mfd/tc3589x.h>

  #define TC3589x_CLKMODE_MODCTL_SLEEP		0x0
  #define TC3589x_CLKMODE_MODCTL_OPERATION	(1 << 0)

  /**

   * tc3589x_reg_read() - read a single TC3589x register
   * @tc3589x:	Device to read from

   * @reg:	Register to read
   */

  int tc3589x_reg_read(struct tc3589x *tc3589x, u8 reg)

  {
  	int ret;

  	ret = i2c_smbus_read_byte_data(tc3589x->i2c, reg);

  	if (ret < 0)

  		dev_err(tc3589x->dev, "failed to read reg %#x: %d
  ",

  			reg, ret);
  
  	return ret;
  }

  EXPORT_SYMBOL_GPL(tc3589x_reg_read);

  
  /**

   * tc3589x_reg_read() - write a single TC3589x register
   * @tc3589x:	Device to write to

   * @reg:	Register to read
   * @data:	Value to write
   */

  int tc3589x_reg_write(struct tc3589x *tc3589x, u8 reg, u8 data)

  {
  	int ret;

  	ret = i2c_smbus_write_byte_data(tc3589x->i2c, reg, data);

  	if (ret < 0)

  		dev_err(tc3589x->dev, "failed to write reg %#x: %d
  ",

  			reg, ret);
  
  	return ret;
  }

  EXPORT_SYMBOL_GPL(tc3589x_reg_write);

  
  /**

   * tc3589x_block_read() - read multiple TC3589x registers
   * @tc3589x:	Device to read from

   * @reg:	First register
   * @length:	Number of registers
   * @values:	Buffer to write to
   */

  int tc3589x_block_read(struct tc3589x *tc3589x, u8 reg, u8 length, u8 *values)

  {
  	int ret;

  	ret = i2c_smbus_read_i2c_block_data(tc3589x->i2c, reg, length, values);

  	if (ret < 0)

  		dev_err(tc3589x->dev, "failed to read regs %#x: %d
  ",

  			reg, ret);
  
  	return ret;
  }

  EXPORT_SYMBOL_GPL(tc3589x_block_read);

  
  /**

   * tc3589x_block_write() - write multiple TC3589x registers
   * @tc3589x:	Device to write to

   * @reg:	First register
   * @length:	Number of registers
   * @values:	Values to write
   */

  int tc3589x_block_write(struct tc3589x *tc3589x, u8 reg, u8 length,

  			const u8 *values)
  {
  	int ret;

  	ret = i2c_smbus_write_i2c_block_data(tc3589x->i2c, reg, length,

  					     values);
  	if (ret < 0)

  		dev_err(tc3589x->dev, "failed to write regs %#x: %d
  ",

  			reg, ret);
  
  	return ret;
  }

  EXPORT_SYMBOL_GPL(tc3589x_block_write);

  
  /**

   * tc3589x_set_bits() - set the value of a bitfield in a TC3589x register
   * @tc3589x:	Device to write to

   * @reg:	Register to write
   * @mask:	Mask of bits to set
   * @values:	Value to set
   */

  int tc3589x_set_bits(struct tc3589x *tc3589x, u8 reg, u8 mask, u8 val)

  {
  	int ret;

  	mutex_lock(&tc3589x->lock);

  	ret = tc3589x_reg_read(tc3589x, reg);

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

  	ret = tc3589x_reg_write(tc3589x, reg, ret);

  
  out:

  	mutex_unlock(&tc3589x->lock);

  	return ret;
  }

  EXPORT_SYMBOL_GPL(tc3589x_set_bits);

  
  static struct resource gpio_resources[] = {
  	{

  		.start	= TC3589x_INT_GPIIRQ,
  		.end	= TC3589x_INT_GPIIRQ,

  		.flags	= IORESOURCE_IRQ,
  	},
  };

  static struct resource keypad_resources[] = {
  	{
  		.start  = TC3589x_INT_KBDIRQ,
  		.end    = TC3589x_INT_KBDIRQ,
  		.flags  = IORESOURCE_IRQ,
  	},
  };

  static struct mfd_cell tc3589x_dev_gpio[] = {

  	{

  		.name		= "tc3589x-gpio",

  		.num_resources	= ARRAY_SIZE(gpio_resources),
  		.resources	= &gpio_resources[0],
  	},
  };

  static struct mfd_cell tc3589x_dev_keypad[] = {
  	{
  		.name           = "tc3589x-keypad",
  		.num_resources  = ARRAY_SIZE(keypad_resources),
  		.resources      = &keypad_resources[0],
  	},
  };

  static irqreturn_t tc3589x_irq(int irq, void *data)

  {

  	struct tc3589x *tc3589x = data;

  	int status;

  again:

  	status = tc3589x_reg_read(tc3589x, TC3589x_IRQST);

  	if (status < 0)
  		return IRQ_NONE;
  
  	while (status) {
  		int bit = __ffs(status);

  		handle_nested_irq(tc3589x->irq_base + bit);

  		status &= ~(1 << bit);
  	}
  
  	/*
  	 * A dummy read or write (to any register) appears to be necessary to
  	 * have the last interrupt clear (for example, GPIO IC write) take

  	 * effect. In such a case, recheck for any interrupt which is still
  	 * pending.

  	 */

  	status = tc3589x_reg_read(tc3589x, TC3589x_IRQST);
  	if (status)
  		goto again;

  
  	return IRQ_HANDLED;
  }

  static int tc3589x_irq_init(struct tc3589x *tc3589x)

  {

  	int base = tc3589x->irq_base;

  	int irq;

  	for (irq = base; irq < base + TC3589x_NR_INTERNAL_IRQS; irq++) {

  		irq_set_chip_data(irq, tc3589x);
  		irq_set_chip_and_handler(irq, &dummy_irq_chip,

  					 handle_edge_irq);

  		irq_set_nested_thread(irq, 1);

  #ifdef CONFIG_ARM
  		set_irq_flags(irq, IRQF_VALID);
  #else

  		irq_set_noprobe(irq);

  #endif
  	}
  
  	return 0;
  }

  static void tc3589x_irq_remove(struct tc3589x *tc3589x)

  {

  	int base = tc3589x->irq_base;

  	int irq;

  	for (irq = base; irq < base + TC3589x_NR_INTERNAL_IRQS; irq++) {

  #ifdef CONFIG_ARM
  		set_irq_flags(irq, 0);
  #endif

  		irq_set_chip_and_handler(irq, NULL, NULL);
  		irq_set_chip_data(irq, NULL);

  	}
  }

  static int tc3589x_chip_init(struct tc3589x *tc3589x)

  {
  	int manf, ver, ret;

  	manf = tc3589x_reg_read(tc3589x, TC3589x_MANFCODE);

  	if (manf < 0)
  		return manf;

  	ver = tc3589x_reg_read(tc3589x, TC3589x_VERSION);

  	if (ver < 0)
  		return ver;

  	if (manf != TC3589x_MANFCODE_MAGIC) {
  		dev_err(tc3589x->dev, "unknown manufacturer: %#x
  ", manf);

  		return -EINVAL;
  	}

  	dev_info(tc3589x->dev, "manufacturer: %#x, version: %#x
  ", manf, ver);

  	/*
  	 * Put everything except the IRQ module into reset;
  	 * also spare the GPIO module for any pin initialization
  	 * done during pre-kernel boot
  	 */

  	ret = tc3589x_reg_write(tc3589x, TC3589x_RSTCTRL,
  				TC3589x_RSTCTRL_TIMRST
  				| TC3589x_RSTCTRL_ROTRST

  				| TC3589x_RSTCTRL_KBDRST);

  	if (ret < 0)
  		return ret;
  
  	/* Clear the reset interrupt. */

  	return tc3589x_reg_write(tc3589x, TC3589x_RSTINTCLR, 0x1);

  }

  static int __devinit tc3589x_device_init(struct tc3589x *tc3589x)
  {
  	int ret = 0;
  	unsigned int blocks = tc3589x->pdata->block;
  
  	if (blocks & TC3589x_BLOCK_GPIO) {
  		ret = mfd_add_devices(tc3589x->dev, -1, tc3589x_dev_gpio,
  				ARRAY_SIZE(tc3589x_dev_gpio), NULL,
  				tc3589x->irq_base);
  		if (ret) {
  			dev_err(tc3589x->dev, "failed to add gpio child
  ");
  			return ret;
  		}
  		dev_info(tc3589x->dev, "added gpio block
  ");
  	}

  	if (blocks & TC3589x_BLOCK_KEYPAD) {
  		ret = mfd_add_devices(tc3589x->dev, -1, tc3589x_dev_keypad,
  				ARRAY_SIZE(tc3589x_dev_keypad), NULL,
  				tc3589x->irq_base);
  		if (ret) {
  			dev_err(tc3589x->dev, "failed to keypad child
  ");
  			return ret;
  		}
  		dev_info(tc3589x->dev, "added keypad block
  ");
  	}

  	return ret;

  }

  static int __devinit tc3589x_probe(struct i2c_client *i2c,

  				   const struct i2c_device_id *id)
  {

  	struct tc3589x_platform_data *pdata = i2c->dev.platform_data;
  	struct tc3589x *tc3589x;

  	int ret;
  
  	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA
  				     | I2C_FUNC_SMBUS_I2C_BLOCK))
  		return -EIO;

  	tc3589x = kzalloc(sizeof(struct tc3589x), GFP_KERNEL);
  	if (!tc3589x)

  		return -ENOMEM;

  	mutex_init(&tc3589x->lock);

  	tc3589x->dev = &i2c->dev;
  	tc3589x->i2c = i2c;
  	tc3589x->pdata = pdata;
  	tc3589x->irq_base = pdata->irq_base;
  	tc3589x->num_gpio = id->driver_data;

  	i2c_set_clientdata(i2c, tc3589x);

  	ret = tc3589x_chip_init(tc3589x);

  	if (ret)
  		goto out_free;

  	ret = tc3589x_irq_init(tc3589x);

  	if (ret)
  		goto out_free;

  	ret = request_threaded_irq(tc3589x->i2c->irq, NULL, tc3589x_irq,

  				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,

  				   "tc3589x", tc3589x);

  	if (ret) {

  		dev_err(tc3589x->dev, "failed to request IRQ: %d
  ", ret);

  		goto out_removeirq;
  	}

  	ret = tc3589x_device_init(tc3589x);

  	if (ret) {

  		dev_err(tc3589x->dev, "failed to add child devices
  ");

  		goto out_freeirq;
  	}
  
  	return 0;
  
  out_freeirq:

  	free_irq(tc3589x->i2c->irq, tc3589x);

  out_removeirq:

  	tc3589x_irq_remove(tc3589x);

  out_free:

  	kfree(tc3589x);

  	return ret;
  }

  static int __devexit tc3589x_remove(struct i2c_client *client)

  {

  	struct tc3589x *tc3589x = i2c_get_clientdata(client);

  	mfd_remove_devices(tc3589x->dev);

  	free_irq(tc3589x->i2c->irq, tc3589x);
  	tc3589x_irq_remove(tc3589x);

  	kfree(tc3589x);

  
  	return 0;
  }

  #ifdef CONFIG_PM

  static int tc3589x_suspend(struct device *dev)
  {
  	struct tc3589x *tc3589x = dev_get_drvdata(dev);
  	struct i2c_client *client = tc3589x->i2c;
  	int ret = 0;
  
  	/* put the system to sleep mode */
  	if (!device_may_wakeup(&client->dev))
  		ret = tc3589x_reg_write(tc3589x, TC3589x_CLKMODE,
  				TC3589x_CLKMODE_MODCTL_SLEEP);
  
  	return ret;
  }
  
  static int tc3589x_resume(struct device *dev)
  {
  	struct tc3589x *tc3589x = dev_get_drvdata(dev);
  	struct i2c_client *client = tc3589x->i2c;
  	int ret = 0;
  
  	/* enable the system into operation */
  	if (!device_may_wakeup(&client->dev))
  		ret = tc3589x_reg_write(tc3589x, TC3589x_CLKMODE,
  				TC3589x_CLKMODE_MODCTL_OPERATION);
  
  	return ret;
  }
  
  static const SIMPLE_DEV_PM_OPS(tc3589x_dev_pm_ops, tc3589x_suspend,
  						tc3589x_resume);

  #endif

  static const struct i2c_device_id tc3589x_id[] = {
  	{ "tc3589x", 24 },

  	{ }
  };

  MODULE_DEVICE_TABLE(i2c, tc3589x_id);

  static struct i2c_driver tc3589x_driver = {
  	.driver.name	= "tc3589x",

  	.driver.owner	= THIS_MODULE,

  #ifdef CONFIG_PM
  	.driver.pm	= &tc3589x_dev_pm_ops,
  #endif

  	.probe		= tc3589x_probe,
  	.remove		= __devexit_p(tc3589x_remove),
  	.id_table	= tc3589x_id,

  };

  static int __init tc3589x_init(void)

  {

  	return i2c_add_driver(&tc3589x_driver);

  }

  subsys_initcall(tc3589x_init);

  static void __exit tc3589x_exit(void)

  {

  	i2c_del_driver(&tc3589x_driver);

  }

  module_exit(tc3589x_exit);

  
  MODULE_LICENSE("GPL v2");

  MODULE_DESCRIPTION("TC3589x MFD core driver");

  MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");