/*
   * 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/of_gpio.h>
  #include <linux/of_irq.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>
  
  #include <linux/rfkill-gpio.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;
  	char			*reset_name;
  	char			*shutdown_name;
  	struct clk		*clk;
  
  	bool			clk_enabled;
  };
  
  static int rfkill_gpio_set_power(void *data, bool blocked)
  {
  	struct rfkill_gpio_data *rfkill = data;
  
  	if (blocked) {
  		gpiod_set_value(rfkill->shutdown_gpio, 1);
  		gpiod_set_value(rfkill->reset_gpio, 1);
  		if (!IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  			clk_disable_unprepare(rfkill->clk);
  	} else {
  		if (!IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  			clk_prepare_enable(rfkill->clk);
  		gpiod_set_value(rfkill->reset_gpio, 0);
  		gpiod_set_value(rfkill->shutdown_gpio, 0);
  	}
  
  	rfkill->clk_enabled = !blocked;
  
  	return 0;
  }
  
  static const struct rfkill_ops rfkill_gpio_ops = {
  	.set_block = rfkill_gpio_set_power,
  };
  
  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->name = dev_name(dev);
  	rfkill->type = (unsigned)id->driver_data;
  
  	return 0;
  }
  
  static int rfkill_gpio_get_pdata_from_of(struct device *dev,
  		struct rfkill_gpio_data *rfkill)
  {
  	struct device_node *np = dev->of_node;
  
  	if (!np) {
  		np = of_find_matching_node(NULL, dev->driver->of_match_table);
  		if (!np) {
  			dev_notice(dev, "device tree node not available
  ");
  			return -ENODEV;
  		}
  	}
  	of_property_read_u32(np, "type", &rfkill->type);
  	of_property_read_string(np, "name", &rfkill->name);
  	return 0;
  }
  
  static int rfkill_gpio_probe(struct platform_device *pdev)
  {
  	struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
  	struct rfkill_gpio_data *rfkill;
  	const char *clk_name = NULL;
  	struct gpio_desc *gpio;
  	int ret;
  	int len;
  
  	rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  	if (!rfkill)
  		return -ENOMEM;
  
  	if (ACPI_HANDLE(&pdev->dev)) {
  		ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
  		if (ret)
  			return ret;
  	} else if (pdata) {
  		clk_name = pdata->power_clk_name;
  		rfkill->name = pdata->name;
  		rfkill->type = pdata->type;
  	} else {
  		ret = rfkill_gpio_get_pdata_from_of(&pdev->dev, rfkill);
  		if (ret) {
  			dev_err(&pdev->dev, "no platform data
  ");
  			return ret;
  		}
  	}
  
  	len = strlen(rfkill->name);
  	rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL);
  	if (!rfkill->reset_name)
  		return -ENOMEM;
  
  	rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL);
  	if (!rfkill->shutdown_name)
  		return -ENOMEM;
  
  	snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name);
  	snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name);
  
  	rfkill->clk = devm_clk_get(&pdev->dev, clk_name);
  
  	gpio = devm_gpiod_get_index(&pdev->dev, rfkill->reset_name, 0);
  	if (!IS_ERR(gpio)) {
  		ret = gpiod_direction_output(gpio, 1);
  		if (ret)
  			return ret;
  		rfkill->reset_gpio = gpio;
  	}
  
  	gpio = devm_gpiod_get_index(&pdev->dev, rfkill->shutdown_name, 0);
  	if (!IS_ERR(gpio)) {
  		ret = gpiod_direction_output(gpio, 1);
  		if (ret)
  			return ret;
  		rfkill->shutdown_gpio = gpio;
  	}
  
  	/* Make sure at-least one of the GPIO is defined and that
  	 * a name is specified for this instance
  	 */
  	if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
  		dev_err(&pdev->dev, "invalid platform data
  ");
  		return -EINVAL;
  	}
  
  	if (pdata && pdata->gpio_runtime_setup) {
  		ret = pdata->gpio_runtime_setup(pdev);
  		if (ret) {
  			dev_err(&pdev->dev, "can't set up gpio
  ");
  			return ret;
  		}
  	}
  
  	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)
  		return ret;
  
  	platform_set_drvdata(pdev, rfkill);
  
  	dev_info(&pdev->dev, "%s device registered.
  ", rfkill->name);
  
  	return 0;
  }
  
  static int rfkill_gpio_remove(struct platform_device *pdev)
  {
  	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
  	struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
  
  	if (pdata && pdata->gpio_runtime_close)
  		pdata->gpio_runtime_close(pdev);
  	rfkill_unregister(rfkill->rfkill_dev);
  	rfkill_destroy(rfkill->rfkill_dev);
  
  	return 0;
  }
  
  static const struct acpi_device_id rfkill_acpi_match[] = {
  	{ "BCM4752", RFKILL_TYPE_GPS },
  	{ },
  };
  
  static const struct of_device_id rfkill_gpio_of_match_table[] = {
  	{ .compatible = "net,rfkill-gpio" },
  	{ }
  };
  MODULE_DEVICE_TABLE(of, rfkill_gpio_of_match_table);
  
  static struct platform_driver rfkill_gpio_driver = {
  	.probe = rfkill_gpio_probe,
  	.remove = rfkill_gpio_remove,
  	.driver = {
  		.name = "rfkill_gpio",
  		.owner = THIS_MODULE,
  		.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
  		.of_match_table = of_match_ptr(rfkill_gpio_of_match_table),
  	},
  };
  
  module_platform_driver(rfkill_gpio_driver);
  
  MODULE_DESCRIPTION("gpio rfkill");
  MODULE_AUTHOR("NVIDIA");
  MODULE_LICENSE("GPL");