text: /*
   * 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/rfkill-gpio.h>
  
  enum rfkill_gpio_clk_state {
  	UNSPECIFIED = 0,
  	PWR_ENABLED,
  	PWR_DISABLED
  };
  
  #define PWR_CLK_SET(_RF, _EN) \
  	((_RF)->pwr_clk_enabled = (!(_EN) ? PWR_ENABLED : PWR_DISABLED))
  #define PWR_CLK_ENABLED(_RF) ((_RF)->pwr_clk_enabled == PWR_ENABLED)
  #define PWR_CLK_DISABLED(_RF) ((_RF)->pwr_clk_enabled != PWR_ENABLED)
  
  struct rfkill_gpio_data {
  	struct rfkill_gpio_platform_data	*pdata;
  	struct rfkill				*rfkill_dev;
  	char					*reset_name;
  	char					*shutdown_name;
  	enum rfkill_gpio_clk_state		pwr_clk_enabled;
  	struct clk				*pwr_clk;
  };
  
  static int rfkill_gpio_set_power(void *data, bool blocked)
  {
  	struct rfkill_gpio_data *rfkill = data;
  
  	if (blocked) {
  		if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
  			gpio_direction_output(rfkill->pdata->shutdown_gpio, 0);
  		if (gpio_is_valid(rfkill->pdata->reset_gpio))
  			gpio_direction_output(rfkill->pdata->reset_gpio, 0);
  		if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill))
  			clk_disable_unprepare(rfkill->pwr_clk);
  	} else {
  		if (rfkill->pwr_clk && PWR_CLK_DISABLED(rfkill))
  			clk_prepare_enable(rfkill->pwr_clk);
  		if (gpio_is_valid(rfkill->pdata->reset_gpio))
  			gpio_direction_output(rfkill->pdata->reset_gpio, 1);
  		if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
  			gpio_direction_output(rfkill->pdata->shutdown_gpio, 1);
  	}
  
  	if (rfkill->pwr_clk)
  		PWR_CLK_SET(rfkill, blocked);
  
  	return 0;
  }
  
  static const struct rfkill_ops rfkill_gpio_ops = {
  	.set_block = rfkill_gpio_set_power,
  };
  
  static int rfkill_gpio_probe(struct platform_device *pdev)
  {
  	struct rfkill_gpio_data *rfkill;
  	struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
  	int ret = 0;
  	int len = 0;
  
  	if (!pdata) {
  		pr_warn("%s: No platform data specified\n", __func__);
  		return -EINVAL;
  	}
  
  	/* make sure at-least one of the GPIO is defined and that
  	 * a name is specified for this instance */
  	if (!pdata->name || (!gpio_is_valid(pdata->reset_gpio) &&
  		!gpio_is_valid(pdata->shutdown_gpio))) {
  		pr_warn("%s: invalid platform data\n", __func__);
  		return -EINVAL;
  	}
  
  	rfkill = kzalloc(sizeof(*rfkill), GFP_KERNEL);
  	if (!rfkill)
  		return -ENOMEM;
  
  	if (pdata->gpio_runtime_setup) {
  		ret = pdata->gpio_runtime_setup(pdev);
  		if (ret) {
  			pr_warn("%s: can't set up gpio\n", __func__);
  			goto fail_alloc;
  		}
  	}
  
  	rfkill->pdata = pdata;
  
  	len = strlen(pdata->name);
  	rfkill->reset_name = kzalloc(len + 7, GFP_KERNEL);
  	if (!rfkill->reset_name) {
  		ret = -ENOMEM;
  		goto fail_alloc;
  	}
  
  	rfkill->shutdown_name = kzalloc(len + 10, GFP_KERNEL);
  	if (!rfkill->shutdown_name) {
  		ret = -ENOMEM;
  		goto fail_reset_name;
  	}
  
  	snprintf(rfkill->reset_name, len + 6 , "%s_reset", pdata->name);
  	snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", pdata->name);
  
  	if (pdata->power_clk_name) {
  		rfkill->pwr_clk = clk_get(&pdev->dev, pdata->power_clk_name);
  		if (IS_ERR(rfkill->pwr_clk)) {
  			pr_warn("%s: can't find pwr_clk.\n", __func__);
  			ret = PTR_ERR(rfkill->pwr_clk);
  			goto fail_shutdown_name;
  		}
  	}
  
  	if (gpio_is_valid(pdata->reset_gpio)) {
  		ret = gpio_request(pdata->reset_gpio, rfkill->reset_name);
  		if (ret) {
  			pr_warn("%s: failed to get reset gpio.\n", __func__);
  			goto fail_clock;
  		}
  	}
  
  	if (gpio_is_valid(pdata->shutdown_gpio)) {
  		ret = gpio_request(pdata->shutdown_gpio, rfkill->shutdown_name);
  		if (ret) {
  			pr_warn("%s: failed to get shutdown gpio.\n", __func__);
  			goto fail_reset;
  		}
  	}
  
  	rfkill->rfkill_dev = rfkill_alloc(pdata->name, &pdev->dev, pdata->type,
  					  &rfkill_gpio_ops, rfkill);
  	if (!rfkill->rfkill_dev) {
  		ret = -ENOMEM;
  		goto fail_shutdown;
  	}
  
  	ret = rfkill_register(rfkill->rfkill_dev);
  	if (ret < 0)
  		goto fail_rfkill;
  
  	platform_set_drvdata(pdev, rfkill);
  
  	dev_info(&pdev->dev, "%s device registered.\n", pdata->name);
  
  	return 0;
  
  fail_rfkill:
  	rfkill_destroy(rfkill->rfkill_dev);
  fail_shutdown:
  	if (gpio_is_valid(pdata->shutdown_gpio))
  		gpio_free(pdata->shutdown_gpio);
  fail_reset:
  	if (gpio_is_valid(pdata->reset_gpio))
  		gpio_free(pdata->reset_gpio);
  fail_clock:
  	if (rfkill->pwr_clk)
  		clk_put(rfkill->pwr_clk);
  fail_shutdown_name:
  	kfree(rfkill->shutdown_name);
  fail_reset_name:
  	kfree(rfkill->reset_name);
  fail_alloc:
  	kfree(rfkill);
  
  	return ret;
  }
  
  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->gpio_runtime_close)
  		pdata->gpio_runtime_close(pdev);
  	rfkill_unregister(rfkill->rfkill_dev);
  	rfkill_destroy(rfkill->rfkill_dev);
  	if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
  		gpio_free(rfkill->pdata->shutdown_gpio);
  	if (gpio_is_valid(rfkill->pdata->reset_gpio))
  		gpio_free(rfkill->pdata->reset_gpio);
  	if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill))
  		clk_disable_unprepare(rfkill->pwr_clk);
  	if (rfkill->pwr_clk)
  		clk_put(rfkill->pwr_clk);
  	kfree(rfkill->shutdown_name);
  	kfree(rfkill->reset_name);
  	kfree(rfkill);
  
  	return 0;
  }
  
  static struct platform_driver rfkill_gpio_driver = {
  	.probe = rfkill_gpio_probe,
  	.remove = rfkill_gpio_remove,
  	.driver = {
  		   .name = "rfkill_gpio",
  		   .owner = THIS_MODULE,
  	},
  };
  
  module_platform_driver(rfkill_gpio_driver);
  
  MODULE_DESCRIPTION("gpio rfkill");
  MODULE_AUTHOR("NVIDIA");
  MODULE_LICENSE("GPL");
  