/*
   * GPIO driver for Analog Devices ADP5520 MFD PMICs
   *
   * Copyright 2009 Analog Devices Inc.
   *
   * Licensed under the GPL-2 or later.
   */
  
  #include <linux/module.h>

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/platform_device.h>
  #include <linux/mfd/adp5520.h>
  
  #include <linux/gpio.h>
  
  struct adp5520_gpio {
  	struct device *master;
  	struct gpio_chip gpio_chip;
  	unsigned char lut[ADP5520_MAXGPIOS];
  	unsigned long output;
  };
  
  static int adp5520_gpio_get_value(struct gpio_chip *chip, unsigned off)
  {
  	struct adp5520_gpio *dev;
  	uint8_t reg_val;
  
  	dev = container_of(chip, struct adp5520_gpio, gpio_chip);
  
  	/*
  	 * There are dedicated registers for GPIO IN/OUT.
  	 * Make sure we return the right value, even when configured as output
  	 */
  
  	if (test_bit(off, &dev->output))

  		adp5520_read(dev->master, ADP5520_GPIO_OUT, &reg_val);

  	else

  		adp5520_read(dev->master, ADP5520_GPIO_IN, &reg_val);

  
  	return !!(reg_val & dev->lut[off]);
  }
  
  static void adp5520_gpio_set_value(struct gpio_chip *chip,
  		unsigned off, int val)
  {
  	struct adp5520_gpio *dev;
  	dev = container_of(chip, struct adp5520_gpio, gpio_chip);
  
  	if (val)

  		adp5520_set_bits(dev->master, ADP5520_GPIO_OUT, dev->lut[off]);

  	else

  		adp5520_clr_bits(dev->master, ADP5520_GPIO_OUT, dev->lut[off]);

  }
  
  static int adp5520_gpio_direction_input(struct gpio_chip *chip, unsigned off)
  {
  	struct adp5520_gpio *dev;
  	dev = container_of(chip, struct adp5520_gpio, gpio_chip);
  
  	clear_bit(off, &dev->output);

  	return adp5520_clr_bits(dev->master, ADP5520_GPIO_CFG_2,
  				dev->lut[off]);

  }
  
  static int adp5520_gpio_direction_output(struct gpio_chip *chip,
  		unsigned off, int val)
  {
  	struct adp5520_gpio *dev;
  	int ret = 0;
  	dev = container_of(chip, struct adp5520_gpio, gpio_chip);
  
  	set_bit(off, &dev->output);
  
  	if (val)

  		ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_OUT,
  					dev->lut[off]);

  	else

  		ret |= adp5520_clr_bits(dev->master, ADP5520_GPIO_OUT,
  					dev->lut[off]);

  	ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_CFG_2,
  					dev->lut[off]);

  
  	return ret;
  }
  
  static int __devinit adp5520_gpio_probe(struct platform_device *pdev)
  {

  	struct adp5520_gpio_platform_data *pdata = pdev->dev.platform_data;

  	struct adp5520_gpio *dev;
  	struct gpio_chip *gc;
  	int ret, i, gpios;
  	unsigned char ctl_mask = 0;
  
  	if (pdata == NULL) {
  		dev_err(&pdev->dev, "missing platform data
  ");
  		return -ENODEV;
  	}
  
  	if (pdev->id != ID_ADP5520) {
  		dev_err(&pdev->dev, "only ADP5520 supports GPIO
  ");
  		return -ENODEV;
  	}
  
  	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  	if (dev == NULL) {
  		dev_err(&pdev->dev, "failed to alloc memory
  ");
  		return -ENOMEM;
  	}
  
  	dev->master = pdev->dev.parent;
  
  	for (gpios = 0, i = 0; i < ADP5520_MAXGPIOS; i++)
  		if (pdata->gpio_en_mask & (1 << i))
  			dev->lut[gpios++] = 1 << i;
  
  	if (gpios < 1) {
  		ret = -EINVAL;
  		goto err;
  	}
  
  	gc = &dev->gpio_chip;
  	gc->direction_input  = adp5520_gpio_direction_input;
  	gc->direction_output = adp5520_gpio_direction_output;
  	gc->get = adp5520_gpio_get_value;
  	gc->set = adp5520_gpio_set_value;
  	gc->can_sleep = 1;
  
  	gc->base = pdata->gpio_start;
  	gc->ngpio = gpios;
  	gc->label = pdev->name;
  	gc->owner = THIS_MODULE;

  	ret = adp5520_clr_bits(dev->master, ADP5520_GPIO_CFG_1,

  		pdata->gpio_en_mask);

  	if (pdata->gpio_en_mask & ADP5520_GPIO_C3)
  		ctl_mask |= ADP5520_C3_MODE;

  	if (pdata->gpio_en_mask & ADP5520_GPIO_R3)
  		ctl_mask |= ADP5520_R3_MODE;

  
  	if (ctl_mask)

  		ret = adp5520_set_bits(dev->master, ADP5520_LED_CONTROL,

  			ctl_mask);

  	ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_PULLUP,

  		pdata->gpio_pullup_mask);
  
  	if (ret) {
  		dev_err(&pdev->dev, "failed to write
  ");
  		goto err;
  	}
  
  	ret = gpiochip_add(&dev->gpio_chip);
  	if (ret)
  		goto err;
  
  	platform_set_drvdata(pdev, dev);
  	return 0;
  
  err:
  	kfree(dev);
  	return ret;
  }
  
  static int __devexit adp5520_gpio_remove(struct platform_device *pdev)
  {
  	struct adp5520_gpio *dev;
  	int ret;
  
  	dev = platform_get_drvdata(pdev);
  	ret = gpiochip_remove(&dev->gpio_chip);
  	if (ret) {
  		dev_err(&pdev->dev, "%s failed, %d
  ",
  				"gpiochip_remove()", ret);
  		return ret;
  	}
  
  	kfree(dev);
  	return 0;
  }
  
  static struct platform_driver adp5520_gpio_driver = {
  	.driver	= {
  		.name	= "adp5520-gpio",
  		.owner	= THIS_MODULE,
  	},
  	.probe		= adp5520_gpio_probe,
  	.remove		= __devexit_p(adp5520_gpio_remove),
  };
  
  static int __init adp5520_gpio_init(void)
  {
  	return platform_driver_register(&adp5520_gpio_driver);
  }
  module_init(adp5520_gpio_init);
  
  static void __exit adp5520_gpio_exit(void)
  {
  	platform_driver_unregister(&adp5520_gpio_driver);
  }
  module_exit(adp5520_gpio_exit);
  
  MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
  MODULE_DESCRIPTION("GPIO ADP5520 Driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:adp5520-gpio");