/*

   * gpiolib support for Wolfson WM831x 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/wm831x/core.h>
  #include <linux/mfd/wm831x/pdata.h>
  #include <linux/mfd/wm831x/gpio.h>

  #include <linux/mfd/wm831x/irq.h>

  struct wm831x_gpio {
  	struct wm831x *wm831x;
  	struct gpio_chip gpio_chip;
  };
  
  static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
  {
  	return container_of(chip, struct wm831x_gpio, gpio_chip);
  }
  
  static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;

  	int val = WM831X_GPN_DIR;
  
  	if (wm831x->has_gpio_ena)
  		val |= WM831X_GPN_TRI;

  
  	return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,

  			       WM831X_GPN_DIR | WM831X_GPN_TRI |
  			       WM831X_GPN_FN_MASK, val);

  }
  
  static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;
  	int ret;
  
  	ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  	if (ret < 0)
  		return ret;
  
  	if (ret & 1 << offset)
  		return 1;
  	else
  		return 0;
  }

  static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)

  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;

  	wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  			value << offset);

  }

  static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  				     unsigned offset, int value)

  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;

  	int val = 0;

  	int ret;

  	if (wm831x->has_gpio_ena)
  		val |= WM831X_GPN_TRI;

  	ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,

  			      WM831X_GPN_DIR | WM831X_GPN_TRI |
  			      WM831X_GPN_FN_MASK, val);

  	if (ret < 0)
  		return ret;
  
  	/* Can only set GPIO state once it's in output mode */
  	wm831x_gpio_set(chip, offset, value);
  
  	return 0;

  }

  static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;
  
  	if (!wm831x->irq_base)
  		return -EINVAL;
  
  	return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
  }

  static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
  				    unsigned debounce)
  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;
  	int reg = WM831X_GPIO1_CONTROL + offset;
  	int ret, fn;
  
  	ret = wm831x_reg_read(wm831x, reg);
  	if (ret < 0)
  		return ret;
  
  	switch (ret & WM831X_GPN_FN_MASK) {
  	case 0:
  	case 1:
  		break;
  	default:
  		/* Not in GPIO mode */
  		return -EBUSY;
  	}
  
  	if (debounce >= 32 && debounce <= 64)
  		fn = 0;
  	else if (debounce >= 4000 && debounce <= 8000)
  		fn = 1;
  	else
  		return -EINVAL;
  
  	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
  }

  #ifdef CONFIG_DEBUG_FS
  static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
  {
  	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  	struct wm831x *wm831x = wm831x_gpio->wm831x;

  	int i, tristated;

  
  	for (i = 0; i < chip->ngpio; i++) {
  		int gpio = i + chip->base;
  		int reg;
  		const char *label, *pull, *powerdomain;
  
  		/* We report the GPIO even if it's not requested since
  		 * we're also reporting things like alternate
  		 * functions which apply even when the GPIO is not in
  		 * use as a GPIO.
  		 */
  		label = gpiochip_is_requested(chip, i);
  		if (!label)
  			label = "Unrequested";
  
  		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
  
  		reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
  		if (reg < 0) {
  			dev_err(wm831x->dev,
  				"GPIO control %d read failed: %d
  ",
  				gpio, reg);
  			seq_printf(s, "
  ");
  			continue;
  		}
  
  		switch (reg & WM831X_GPN_PULL_MASK) {
  		case WM831X_GPIO_PULL_NONE:
  			pull = "nopull";
  			break;
  		case WM831X_GPIO_PULL_DOWN:
  			pull = "pulldown";
  			break;
  		case WM831X_GPIO_PULL_UP:
  			pull = "pullup";

  			break;

  		default:
  			pull = "INVALID PULL";
  			break;
  		}
  
  		switch (i + 1) {
  		case 1 ... 3:
  		case 7 ... 9:
  			if (reg & WM831X_GPN_PWR_DOM)
  				powerdomain = "VPMIC";
  			else
  				powerdomain = "DBVDD";
  			break;
  
  		case 4 ... 6:
  		case 10 ... 12:
  			if (reg & WM831X_GPN_PWR_DOM)
  				powerdomain = "SYSVDD";
  			else
  				powerdomain = "DBVDD";
  			break;
  
  		case 13 ... 16:
  			powerdomain = "TPVDD";
  			break;
  
  		default:
  			BUG();
  			break;
  		}

  		tristated = reg & WM831X_GPN_TRI;
  		if (wm831x->has_gpio_ena)
  			tristated = !tristated;

  		seq_printf(s, " %s %s %s %s%s
  "
  			   "                                  %s%s (0x%4x)
  ",
  			   reg & WM831X_GPN_DIR ? "in" : "out",
  			   wm831x_gpio_get(chip, i) ? "high" : "low",
  			   pull,
  			   powerdomain,

  			   reg & WM831X_GPN_POL ? "" : " inverted",

  			   reg & WM831X_GPN_OD ? "open-drain" : "CMOS",

  			   tristated ? " tristated" : "",

  			   reg);
  	}
  }
  #else
  #define wm831x_gpio_dbg_show NULL
  #endif
  
  static struct gpio_chip template_chip = {
  	.label			= "wm831x",
  	.owner			= THIS_MODULE,
  	.direction_input	= wm831x_gpio_direction_in,
  	.get			= wm831x_gpio_get,
  	.direction_output	= wm831x_gpio_direction_out,
  	.set			= wm831x_gpio_set,

  	.to_irq			= wm831x_gpio_to_irq,

  	.set_debounce		= wm831x_gpio_set_debounce,

  	.dbg_show		= wm831x_gpio_dbg_show,
  	.can_sleep		= 1,
  };
  
  static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
  	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
  	struct wm831x_gpio *wm831x_gpio;
  	int ret;
  
  	wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
  	if (wm831x_gpio == NULL)
  		return -ENOMEM;
  
  	wm831x_gpio->wm831x = wm831x;
  	wm831x_gpio->gpio_chip = template_chip;

  	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;

  	wm831x_gpio->gpio_chip.dev = &pdev->dev;
  	if (pdata && pdata->gpio_base)
  		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
  	else
  		wm831x_gpio->gpio_chip.base = -1;
  
  	ret = gpiochip_add(&wm831x_gpio->gpio_chip);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "Could not register gpiochip, %d
  ",
  			ret);
  		goto err;
  	}
  
  	platform_set_drvdata(pdev, wm831x_gpio);
  
  	return ret;
  
  err:
  	kfree(wm831x_gpio);
  	return ret;
  }
  
  static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
  {
  	struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
  	int ret;
  
  	ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
  	if (ret == 0)
  		kfree(wm831x_gpio);
  
  	return ret;
  }
  
  static struct platform_driver wm831x_gpio_driver = {
  	.driver.name	= "wm831x-gpio",
  	.driver.owner	= THIS_MODULE,
  	.probe		= wm831x_gpio_probe,
  	.remove		= __devexit_p(wm831x_gpio_remove),
  };
  
  static int __init wm831x_gpio_init(void)
  {
  	return platform_driver_register(&wm831x_gpio_driver);
  }
  subsys_initcall(wm831x_gpio_init);
  
  static void __exit wm831x_gpio_exit(void)
  {
  	platform_driver_unregister(&wm831x_gpio_driver);
  }
  module_exit(wm831x_gpio_exit);
  
  MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
  MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm831x-gpio");