text: /*
   * wm835x-gpiolib.c  --  gpiolib support for Wolfson WM835x PMICs
   *
   * Copyright 2009 Wolfson Microelectronics PLC.
   *
   * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the  License, or (at your
   *  option) any later version.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/gpio.h>
  #include <linux/mfd/core.h>
  #include <linux/platform_device.h>
  #include <linux/seq_file.h>
  
  #include <linux/mfd/wm8350/core.h>
  #include <linux/mfd/wm8350/gpio.h>
  
  struct wm8350_gpio_data {
  	struct wm8350 *wm8350;
  	struct gpio_chip gpio_chip;
  };
  
  static inline struct wm8350_gpio_data *to_wm8350_gpio(struct gpio_chip *chip)
  {
  	return container_of(chip, struct wm8350_gpio_data, gpio_chip);
  }
  
  static int wm8350_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  	struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  
  	return wm8350_set_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
  			       1 << offset);
  }
  
  static int wm8350_gpio_get(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  	struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  	int ret;
  
  	ret = wm8350_reg_read(wm8350, WM8350_GPIO_LEVEL);
  	if (ret < 0)
  		return ret;
  
  	if (ret & (1 << offset))
  		return 1;
  	else
  		return 0;
  }
  
  static void wm8350_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  {
  	struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  	struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  
  	if (value)
  		wm8350_set_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
  	else
  		wm8350_clear_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
  }
  
  static int wm8350_gpio_direction_out(struct gpio_chip *chip,
  				     unsigned offset, int value)
  {
  	struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  	struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  	int ret;
  
  	ret = wm8350_clear_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
  				1 << offset);
  	if (ret < 0)
  		return ret;
  
  	/* Don't have an atomic direction/value setup */
  	wm8350_gpio_set(chip, offset, value);
  
  	return 0;
  }
  
  static int wm8350_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  	struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  
  	if (!wm8350->irq_base)
  		return -EINVAL;
  
  	return wm8350->irq_base + WM8350_IRQ_GPIO(offset);
  }
  
  static struct gpio_chip template_chip = {
  	.label			= "wm8350",
  	.owner			= THIS_MODULE,
  	.direction_input	= wm8350_gpio_direction_in,
  	.get			= wm8350_gpio_get,
  	.direction_output	= wm8350_gpio_direction_out,
  	.set			= wm8350_gpio_set,
  	.to_irq			= wm8350_gpio_to_irq,
  	.can_sleep		= 1,
  };
  
  static int __devinit wm8350_gpio_probe(struct platform_device *pdev)
  {
  	struct wm8350 *wm8350 = dev_get_drvdata(pdev->dev.parent);
  	struct wm8350_platform_data *pdata = wm8350->dev->platform_data;
  	struct wm8350_gpio_data *wm8350_gpio;
  	int ret;
  
  	wm8350_gpio = kzalloc(sizeof(*wm8350_gpio), GFP_KERNEL);
  	if (wm8350_gpio == NULL)
  		return -ENOMEM;
  
  	wm8350_gpio->wm8350 = wm8350;
  	wm8350_gpio->gpio_chip = template_chip;
  	wm8350_gpio->gpio_chip.ngpio = 13;
  	wm8350_gpio->gpio_chip.dev = &pdev->dev;
  	if (pdata && pdata->gpio_base)
  		wm8350_gpio->gpio_chip.base = pdata->gpio_base;
  	else
  		wm8350_gpio->gpio_chip.base = -1;
  
  	ret = gpiochip_add(&wm8350_gpio->gpio_chip);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
  			ret);
  		goto err;
  	}
  
  	platform_set_drvdata(pdev, wm8350_gpio);
  
  	return ret;
  
  err:
  	kfree(wm8350_gpio);
  	return ret;
  }
  
  static int __devexit wm8350_gpio_remove(struct platform_device *pdev)
  {
  	struct wm8350_gpio_data *wm8350_gpio = platform_get_drvdata(pdev);
  	int ret;
  
  	ret = gpiochip_remove(&wm8350_gpio->gpio_chip);
  	if (ret == 0)
  		kfree(wm8350_gpio);
  
  	return ret;
  }
  
  static struct platform_driver wm8350_gpio_driver = {
  	.driver.name	= "wm8350-gpio",
  	.driver.owner	= THIS_MODULE,
  	.probe		= wm8350_gpio_probe,
  	.remove		= __devexit_p(wm8350_gpio_remove),
  };
  
  static int __init wm8350_gpio_init(void)
  {
  	return platform_driver_register(&wm8350_gpio_driver);
  }
  subsys_initcall(wm8350_gpio_init);
  
  static void __exit wm8350_gpio_exit(void)
  {
  	platform_driver_unregister(&wm8350_gpio_driver);
  }
  module_exit(wm8350_gpio_exit);
  
  MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
  MODULE_DESCRIPTION("GPIO interface for WM8350 PMICs");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm8350-gpio");
  