/*
   * Copyright (c) 2011, NVIDIA Corporation.
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along
   * with this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   */
  
  #include <linux/gpio.h>
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/rfkill.h>
  #include <linux/platform_device.h>
  #include <linux/clk.h>
  #include <linux/slab.h>

  #include <linux/acpi.h>

  #include <linux/gpio/consumer.h>

  struct rfkill_gpio_data {

  	const char		*name;
  	enum rfkill_type	type;

  	struct gpio_desc	*reset_gpio;
  	struct gpio_desc	*shutdown_gpio;

  
  	struct rfkill		*rfkill_dev;

  	struct clk		*clk;
  
  	bool			clk_enabled;

  };
  
  static int rfkill_gpio_set_power(void *data, bool blocked)
  {
  	struct rfkill_gpio_data *rfkill = data;

  	if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  		clk_enable(rfkill->clk);
  
  	gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
  	gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
  
  	if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  		clk_disable(rfkill->clk);

  	rfkill->clk_enabled = !blocked;

  
  	return 0;
  }
  
  static const struct rfkill_ops rfkill_gpio_ops = {
  	.set_block = rfkill_gpio_set_power,
  };

  static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
  static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
  
  static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
  	{ "reset-gpios", &reset_gpios, 1 },
  	{ "shutdown-gpios", &shutdown_gpios, 1 },
  	{ },
  };

  static int rfkill_gpio_acpi_probe(struct device *dev,
  				  struct rfkill_gpio_data *rfkill)
  {
  	const struct acpi_device_id *id;
  
  	id = acpi_match_device(dev->driver->acpi_match_table, dev);
  	if (!id)
  		return -ENODEV;

  	rfkill->type = (unsigned)id->driver_data;

  	return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);

  }

  static int rfkill_gpio_probe(struct platform_device *pdev)
  {

  	struct rfkill_gpio_data *rfkill;

  	struct gpio_desc *gpio;

  	const char *type_name;

  	int ret;

  	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  	if (!rfkill)
  		return -ENOMEM;

  	device_property_read_string(&pdev->dev, "name", &rfkill->name);
  	device_property_read_string(&pdev->dev, "type", &type_name);
  
  	if (!rfkill->name)
  		rfkill->name = dev_name(&pdev->dev);
  
  	rfkill->type = rfkill_find_type(type_name);

  	if (ACPI_HANDLE(&pdev->dev)) {
  		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
  		if (ret)
  			return ret;

  	}

  	rfkill->clk = devm_clk_get(&pdev->dev, NULL);

  	gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
  	if (IS_ERR(gpio))
  		return PTR_ERR(gpio);

  	rfkill->reset_gpio = gpio;
  
  	gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
  	if (IS_ERR(gpio))
  		return PTR_ERR(gpio);
  
  	rfkill->shutdown_gpio = gpio;

  	/* Make sure at-least one GPIO is defined for this instance */
  	if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {

  		dev_err(&pdev->dev, "invalid platform data
  ");
  		return -EINVAL;
  	}

  	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
  					  rfkill->type, &rfkill_gpio_ops,
  					  rfkill);

  	if (!rfkill->rfkill_dev)
  		return -ENOMEM;

  
  	ret = rfkill_register(rfkill->rfkill_dev);
  	if (ret < 0)

  		goto err_destroy;

  
  	platform_set_drvdata(pdev, rfkill);

  	dev_info(&pdev->dev, "%s device registered.
  ", rfkill->name);

  
  	return 0;

  
  err_destroy:
  	rfkill_destroy(rfkill->rfkill_dev);
  
  	return ret;

  }
  
  static int rfkill_gpio_remove(struct platform_device *pdev)
  {
  	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
  
  	rfkill_unregister(rfkill->rfkill_dev);
  	rfkill_destroy(rfkill->rfkill_dev);

  
  	return 0;
  }

  #ifdef CONFIG_ACPI

  static const struct acpi_device_id rfkill_acpi_match[] = {
  	{ "BCM4752", RFKILL_TYPE_GPS },

  	{ "LNV4752", RFKILL_TYPE_GPS },

  	{ },
  };

  MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);

  #endif

  static struct platform_driver rfkill_gpio_driver = {
  	.probe = rfkill_gpio_probe,

  	.remove = rfkill_gpio_remove,

  	.driver = {

  		.name = "rfkill_gpio",

  		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),

  	},
  };

  module_platform_driver(rfkill_gpio_driver);

  
  MODULE_DESCRIPTION("gpio rfkill");
  MODULE_AUTHOR("NVIDIA");
  MODULE_LICENSE("GPL");