/*

   * gpiolib support for Wolfson WM8994

   *
   * 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/wm8994/core.h>
  #include <linux/mfd/wm8994/pdata.h>
  #include <linux/mfd/wm8994/gpio.h>
  #include <linux/mfd/wm8994/registers.h>
  
  struct wm8994_gpio {
  	struct wm8994 *wm8994;
  	struct gpio_chip gpio_chip;
  };
  
  static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
  {
  	return container_of(chip, struct wm8994_gpio, gpio_chip);
  }

  static int wm8994_gpio_request(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  
  	switch (wm8994->type) {
  	case WM8958:
  		switch (offset) {
  		case 1:
  		case 2:
  		case 3:
  		case 4:
  		case 6:
  			return -EINVAL;
  		}
  		break;
  	default:
  		break;
  	}
  
  	return 0;
  }

  static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  
  	return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
  			       WM8994_GPN_DIR, WM8994_GPN_DIR);
  }
  
  static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  	int ret;
  
  	ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
  	if (ret < 0)
  		return ret;
  
  	if (ret & WM8994_GPN_LVL)
  		return 1;
  	else
  		return 0;
  }
  
  static int wm8994_gpio_direction_out(struct gpio_chip *chip,
  				     unsigned offset, int value)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  
  	return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
  			       WM8994_GPN_DIR, 0);
  }
  
  static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  
  	if (value)
  		value = WM8994_GPN_LVL;
  
  	wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
  }

  static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  
  	if (!wm8994->irq_base)
  		return -EINVAL;
  
  	return wm8994->irq_base + offset;
  }

  #ifdef CONFIG_DEBUG_FS

  static const char *wm8994_gpio_fn(u16 fn)
  {
  	switch (fn) {
  	case WM8994_GP_FN_PIN_SPECIFIC:
  		return "pin-specific";
  	case WM8994_GP_FN_GPIO:
  		return "GPIO";
  	case WM8994_GP_FN_SDOUT:
  		return "SDOUT";
  	case WM8994_GP_FN_IRQ:
  		return "IRQ";
  	case WM8994_GP_FN_TEMPERATURE:
  		return "Temperature";
  	case WM8994_GP_FN_MICBIAS1_DET:
  		return "MICBIAS1 detect";
  	case WM8994_GP_FN_MICBIAS1_SHORT:
  		return "MICBIAS1 short";
  	case WM8994_GP_FN_MICBIAS2_DET:
  		return "MICBIAS2 detect";
  	case WM8994_GP_FN_MICBIAS2_SHORT:
  		return "MICBIAS2 short";
  	case WM8994_GP_FN_FLL1_LOCK:
  		return "FLL1 lock";
  	case WM8994_GP_FN_FLL2_LOCK:
  		return "FLL2 lock";
  	case WM8994_GP_FN_SRC1_LOCK:
  		return "SRC1 lock";
  	case WM8994_GP_FN_SRC2_LOCK:
  		return "SRC2 lock";
  	case WM8994_GP_FN_DRC1_ACT:
  		return "DRC1 activity";
  	case WM8994_GP_FN_DRC2_ACT:
  		return "DRC2 activity";
  	case WM8994_GP_FN_DRC3_ACT:
  		return "DRC3 activity";
  	case WM8994_GP_FN_WSEQ_STATUS:
  		return "Write sequencer";
  	case WM8994_GP_FN_FIFO_ERROR:
  		return "FIFO error";
  	case WM8994_GP_FN_OPCLK:
  		return "OPCLK";
  	case WM8994_GP_FN_THW:
  		return "Thermal warning";
  	case WM8994_GP_FN_DCS_DONE:
  		return "DC servo";
  	case WM8994_GP_FN_FLL1_OUT:
  		return "FLL1 output";
  	case WM8994_GP_FN_FLL2_OUT:
  		return "FLL1 output";
  	default:
  		return "Unknown";
  	}
  }

  static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
  {
  	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  	int i;
  
  	for (i = 0; i < chip->ngpio; i++) {
  		int gpio = i + chip->base;
  		int reg;
  		const char *label;
  
  		/* 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 = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
  		if (reg < 0) {
  			dev_err(wm8994->dev,
  				"GPIO control %d read failed: %d
  ",
  				gpio, reg);
  			seq_printf(s, "
  ");
  			continue;
  		}

  		if (reg & WM8994_GPN_DIR)
  			seq_printf(s, "in ");
  		else
  			seq_printf(s, "out ");
  
  		if (reg & WM8994_GPN_PU)
  			seq_printf(s, "pull up ");
  
  		if (reg & WM8994_GPN_PD)
  			seq_printf(s, "pull down ");
  
  		if (reg & WM8994_GPN_POL)
  			seq_printf(s, "inverted ");
  		else
  			seq_printf(s, "noninverted ");
  
  		if (reg & WM8994_GPN_OP_CFG)
  			seq_printf(s, "open drain ");
  		else
  			seq_printf(s, "CMOS ");
  
  		seq_printf(s, "%s (%x)
  ",
  			   wm8994_gpio_fn(reg & WM8994_GPN_FN_MASK), reg);

  	}
  }
  #else
  #define wm8994_gpio_dbg_show NULL
  #endif
  
  static struct gpio_chip template_chip = {
  	.label			= "wm8994",
  	.owner			= THIS_MODULE,

  	.request		= wm8994_gpio_request,

  	.direction_input	= wm8994_gpio_direction_in,
  	.get			= wm8994_gpio_get,
  	.direction_output	= wm8994_gpio_direction_out,
  	.set			= wm8994_gpio_set,

  	.to_irq			= wm8994_gpio_to_irq,

  	.dbg_show		= wm8994_gpio_dbg_show,
  	.can_sleep		= 1,
  };
  
  static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
  {
  	struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
  	struct wm8994_pdata *pdata = wm8994->dev->platform_data;
  	struct wm8994_gpio *wm8994_gpio;
  	int ret;
  
  	wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
  	if (wm8994_gpio == NULL)
  		return -ENOMEM;
  
  	wm8994_gpio->wm8994 = wm8994;
  	wm8994_gpio->gpio_chip = template_chip;
  	wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
  	wm8994_gpio->gpio_chip.dev = &pdev->dev;
  	if (pdata && pdata->gpio_base)
  		wm8994_gpio->gpio_chip.base = pdata->gpio_base;
  	else
  		wm8994_gpio->gpio_chip.base = -1;
  
  	ret = gpiochip_add(&wm8994_gpio->gpio_chip);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "Could not register gpiochip, %d
  ",
  			ret);
  		goto err;
  	}
  
  	platform_set_drvdata(pdev, wm8994_gpio);
  
  	return ret;
  
  err:
  	kfree(wm8994_gpio);
  	return ret;
  }
  
  static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
  {
  	struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
  	int ret;
  
  	ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
  	if (ret == 0)
  		kfree(wm8994_gpio);
  
  	return ret;
  }
  
  static struct platform_driver wm8994_gpio_driver = {
  	.driver.name	= "wm8994-gpio",
  	.driver.owner	= THIS_MODULE,
  	.probe		= wm8994_gpio_probe,
  	.remove		= __devexit_p(wm8994_gpio_remove),
  };
  
  static int __init wm8994_gpio_init(void)
  {
  	return platform_driver_register(&wm8994_gpio_driver);
  }
  subsys_initcall(wm8994_gpio_init);
  
  static void __exit wm8994_gpio_exit(void)
  {
  	platform_driver_unregister(&wm8994_gpio_driver);
  }
  module_exit(wm8994_gpio_exit);
  
  MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
  MODULE_DESCRIPTION("GPIO interface for WM8994");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm8994-gpio");