/*
   * Copyright 2015 Verifone Int.
   *
   * Author: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify i t
   * under  the terms of the GNU General  Public License as published by th e
   * Free Software Foundation;  either version 2 of the License, or (at you r
   * option) any later version.
   *
   * This driver is based on the gpio-tps65912 implementation.
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/errno.h>
  #include <linux/gpio/driver.h>
  #include <linux/platform_device.h>

  #include <linux/regmap.h>

  #include <linux/mfd/tps65218.h>

  
  struct tps65218_gpio {
  	struct tps65218 *tps65218;
  	struct gpio_chip gpio_chip;
  };
  
  static int tps65218_gpio_get(struct gpio_chip *gc, unsigned offset)
  {
  	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
  	struct tps65218 *tps65218 = tps65218_gpio->tps65218;
  	unsigned int val;
  	int ret;

  	ret = regmap_read(tps65218->regmap, TPS65218_REG_ENABLE2, &val);

  	if (ret)
  		return ret;
  
  	return !!(val & (TPS65218_ENABLE2_GPIO1 << offset));
  }
  
  static void tps65218_gpio_set(struct gpio_chip *gc, unsigned offset,
  			      int value)
  {
  	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
  	struct tps65218 *tps65218 = tps65218_gpio->tps65218;
  
  	if (value)
  		tps65218_set_bits(tps65218, TPS65218_REG_ENABLE2,
  				  TPS65218_ENABLE2_GPIO1 << offset,
  				  TPS65218_ENABLE2_GPIO1 << offset,
  				  TPS65218_PROTECT_L1);
  	else
  		tps65218_clear_bits(tps65218, TPS65218_REG_ENABLE2,
  				    TPS65218_ENABLE2_GPIO1 << offset,
  				    TPS65218_PROTECT_L1);
  }
  
  static int tps65218_gpio_output(struct gpio_chip *gc, unsigned offset,
  				int value)
  {
  	/* Only drives GPOs */

  	tps65218_gpio_set(gc, offset, value);

  	return 0;
  }
  
  static int tps65218_gpio_input(struct gpio_chip *gc, unsigned offset)
  {
  	return -EPERM;
  }
  
  static int tps65218_gpio_request(struct gpio_chip *gc, unsigned offset)
  {
  	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
  	struct tps65218 *tps65218 = tps65218_gpio->tps65218;

  	int ret;

  	if (gpiochip_line_is_open_source(gc, offset)) {

  		dev_err(gc->parent, "can't work as open source
  ");
  		return -EINVAL;
  	}
  
  	switch (offset) {
  	case 0:

  		if (!gpiochip_line_is_open_drain(gc, offset)) {

  			dev_err(gc->parent, "GPO1 works only as open drain
  ");
  			return -EINVAL;
  		}
  
  		/* Disable sequencer for GPO1 */
  		ret = tps65218_clear_bits(tps65218, TPS65218_REG_SEQ7,
  					  TPS65218_SEQ7_GPO1_SEQ_MASK,
  					  TPS65218_PROTECT_L1);
  		if (ret)
  			return ret;
  
  		/* Setup GPO1 */
  		ret = tps65218_clear_bits(tps65218, TPS65218_REG_CONFIG1,
  					  TPS65218_CONFIG1_IO1_SEL,
  					  TPS65218_PROTECT_L1);
  		if (ret)
  			return ret;
  
  		break;
  	case 1:

  		/* Setup GPO2 */
  		ret = tps65218_clear_bits(tps65218, TPS65218_REG_CONFIG1,
  					  TPS65218_CONFIG1_IO1_SEL,
  					  TPS65218_PROTECT_L1);
  		if (ret)
  			return ret;
  
  		break;
  
  	case 2:

  		if (!gpiochip_line_is_open_drain(gc, offset)) {

  			dev_err(gc->parent, "GPO3 works only as open drain
  ");
  			return -EINVAL;
  		}
  
  		/* Disable sequencer for GPO3 */
  		ret = tps65218_clear_bits(tps65218, TPS65218_REG_SEQ7,
  					  TPS65218_SEQ7_GPO3_SEQ_MASK,
  					  TPS65218_PROTECT_L1);
  		if (ret)
  			return ret;
  
  		/* Setup GPO3 */
  		ret = tps65218_clear_bits(tps65218, TPS65218_REG_CONFIG2,
  					  TPS65218_CONFIG2_DC12_RST,
  					  TPS65218_PROTECT_L1);
  		if (ret)
  			return ret;
  
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }

  static int tps65218_gpio_set_config(struct gpio_chip *gc, unsigned offset,
  				    unsigned long config)

  {
  	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
  	struct tps65218 *tps65218 = tps65218_gpio->tps65218;

  	enum pin_config_param param = pinconf_to_config_param(config);

  
  	switch (offset) {
  	case 0:
  	case 2:
  		/* GPO1 is hardwired to be open drain */

  		if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)

  			return 0;
  		return -ENOTSUPP;
  	case 1:
  		/* GPO2 is push-pull by default, can be set as open drain. */

  		if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)

  			return tps65218_clear_bits(tps65218,
  						   TPS65218_REG_CONFIG1,
  						   TPS65218_CONFIG1_GPO2_BUF,
  						   TPS65218_PROTECT_L1);

  		if (param == PIN_CONFIG_DRIVE_PUSH_PULL)

  			return tps65218_set_bits(tps65218,
  						 TPS65218_REG_CONFIG1,
  						 TPS65218_CONFIG1_GPO2_BUF,
  						 TPS65218_CONFIG1_GPO2_BUF,
  						 TPS65218_PROTECT_L1);
  		return -ENOTSUPP;
  	default:
  		break;
  	}
  	return -ENOTSUPP;
  }

  static const struct gpio_chip template_chip = {

  	.label			= "gpio-tps65218",
  	.owner			= THIS_MODULE,
  	.request		= tps65218_gpio_request,
  	.direction_output	= tps65218_gpio_output,
  	.direction_input	= tps65218_gpio_input,
  	.get			= tps65218_gpio_get,
  	.set			= tps65218_gpio_set,

  	.set_config		= tps65218_gpio_set_config,

  	.can_sleep		= true,
  	.ngpio			= 3,
  	.base			= -1,
  };
  
  static int tps65218_gpio_probe(struct platform_device *pdev)
  {
  	struct tps65218 *tps65218 = dev_get_drvdata(pdev->dev.parent);
  	struct tps65218_gpio *tps65218_gpio;
  	int ret;
  
  	tps65218_gpio = devm_kzalloc(&pdev->dev, sizeof(*tps65218_gpio),
  				     GFP_KERNEL);
  	if (!tps65218_gpio)
  		return -ENOMEM;
  
  	tps65218_gpio->tps65218 = tps65218;
  	tps65218_gpio->gpio_chip = template_chip;
  	tps65218_gpio->gpio_chip.parent = &pdev->dev;
  #ifdef CONFIG_OF_GPIO
  	tps65218_gpio->gpio_chip.of_node = pdev->dev.of_node;
  #endif

  	ret = devm_gpiochip_add_data(&pdev->dev, &tps65218_gpio->gpio_chip,
  				     tps65218_gpio);

  	if (ret < 0) {
  		dev_err(&pdev->dev, "Failed to register gpiochip, %d
  ", ret);
  		return ret;
  	}
  
  	platform_set_drvdata(pdev, tps65218_gpio);
  
  	return ret;
  }

  static const struct of_device_id tps65218_dt_match[] = {
  	{ .compatible = "ti,tps65218-gpio" },
  	{  }
  };
  MODULE_DEVICE_TABLE(of, tps65218_dt_match);

  static const struct platform_device_id tps65218_gpio_id_table[] = {
  	{ "tps65218-gpio", },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(platform, tps65218_gpio_id_table);

  static struct platform_driver tps65218_gpio_driver = {
  	.driver = {
  		.name = "tps65218-gpio",
  		.of_match_table = of_match_ptr(tps65218_dt_match)
  	},
  	.probe = tps65218_gpio_probe,

  	.id_table = tps65218_gpio_id_table,

  };
  
  module_platform_driver(tps65218_gpio_driver);
  
  MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");
  MODULE_DESCRIPTION("GPO interface for TPS65218 PMICs");
  MODULE_LICENSE("GPL v2");
  MODULE_ALIAS("platform:tps65218-gpio");