text: /*
   *  acpi_fan.c - ACPI Fan Driver ($Revision: 29 $)
   *
   *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.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.
   *
   *  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.
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/types.h>
  #include <linux/uaccess.h>
  #include <linux/thermal.h>
  #include <linux/acpi.h>
  #include <linux/platform_device.h>
  #include <linux/sort.h>
  
  MODULE_AUTHOR("Paul Diefenbaugh");
  MODULE_DESCRIPTION("ACPI Fan Driver");
  MODULE_LICENSE("GPL");
  
  static int acpi_fan_probe(struct platform_device *pdev);
  static int acpi_fan_remove(struct platform_device *pdev);
  
  static const struct acpi_device_id fan_device_ids[] = {
  	{"PNP0C0B", 0},
  	{"INT3404", 0},
  	{"", 0},
  };
  MODULE_DEVICE_TABLE(acpi, fan_device_ids);
  
  #ifdef CONFIG_PM_SLEEP
  static int acpi_fan_suspend(struct device *dev);
  static int acpi_fan_resume(struct device *dev);
  static const struct dev_pm_ops acpi_fan_pm = {
  	.resume = acpi_fan_resume,
  	.freeze = acpi_fan_suspend,
  	.thaw = acpi_fan_resume,
  	.restore = acpi_fan_resume,
  };
  #define FAN_PM_OPS_PTR (&acpi_fan_pm)
  #else
  #define FAN_PM_OPS_PTR NULL
  #endif
  
  struct acpi_fan_fps {
  	u64 control;
  	u64 trip_point;
  	u64 speed;
  	u64 noise_level;
  	u64 power;
  };
  
  struct acpi_fan_fif {
  	u64 revision;
  	u64 fine_grain_ctrl;
  	u64 step_size;
  	u64 low_speed_notification;
  };
  
  struct acpi_fan {
  	bool acpi4;
  	struct acpi_fan_fif fif;
  	struct acpi_fan_fps *fps;
  	int fps_count;
  	struct thermal_cooling_device *cdev;
  };
  
  static struct platform_driver acpi_fan_driver = {
  	.probe = acpi_fan_probe,
  	.remove = acpi_fan_remove,
  	.driver = {
  		.name = "acpi-fan",
  		.acpi_match_table = fan_device_ids,
  		.pm = FAN_PM_OPS_PTR,
  	},
  };
  
  /* thermal cooling device callbacks */
  static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
  			     *state)
  {
  	struct acpi_device *device = cdev->devdata;
  	struct acpi_fan *fan = acpi_driver_data(device);
  
  	if (fan->acpi4)
  		*state = fan->fps_count - 1;
  	else
  		*state = 1;
  	return 0;
  }
  
  static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
  {
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	struct acpi_fan *fan = acpi_driver_data(device);
  	union acpi_object *obj;
  	acpi_status status;
  	int control, i;
  
  	status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
  	if (ACPI_FAILURE(status)) {
  		dev_err(&device->dev, "Get fan state failed\n");
  		return status;
  	}
  
  	obj = buffer.pointer;
  	if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
  	    obj->package.count != 3 ||
  	    obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
  		dev_err(&device->dev, "Invalid _FST data\n");
  		status = -EINVAL;
  		goto err;
  	}
  
  	control = obj->package.elements[1].integer.value;
  	for (i = 0; i < fan->fps_count; i++) {
  		/*
  		 * When Fine Grain Control is set, return the state
  		 * corresponding to maximum fan->fps[i].control
  		 * value compared to the current speed. Here the
  		 * fan->fps[] is sorted array with increasing speed.
  		 */
  		if (fan->fif.fine_grain_ctrl && control < fan->fps[i].control) {
  			i = (i > 0) ? i - 1 : 0;
  			break;
  		} else if (control == fan->fps[i].control) {
  			break;
  		}
  	}
  	if (i == fan->fps_count) {
  		dev_dbg(&device->dev, "Invalid control value returned\n");
  		status = -EINVAL;
  		goto err;
  	}
  
  	*state = i;
  
  err:
  	kfree(obj);
  	return status;
  }
  
  static int fan_get_state(struct acpi_device *device, unsigned long *state)
  {
  	int result;
  	int acpi_state = ACPI_STATE_D0;
  
  	result = acpi_device_update_power(device, &acpi_state);
  	if (result)
  		return result;
  
  	*state = acpi_state == ACPI_STATE_D3_COLD
  			|| acpi_state == ACPI_STATE_D3_HOT ?
  		0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
  	return 0;
  }
  
  static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
  			     *state)
  {
  	struct acpi_device *device = cdev->devdata;
  	struct acpi_fan *fan = acpi_driver_data(device);
  
  	if (fan->acpi4)
  		return fan_get_state_acpi4(device, state);
  	else
  		return fan_get_state(device, state);
  }
  
  static int fan_set_state(struct acpi_device *device, unsigned long state)
  {
  	if (state != 0 && state != 1)
  		return -EINVAL;
  
  	return acpi_device_set_power(device,
  				     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
  }
  
  static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
  {
  	struct acpi_fan *fan = acpi_driver_data(device);
  	acpi_status status;
  
  	if (state >= fan->fps_count)
  		return -EINVAL;
  
  	status = acpi_execute_simple_method(device->handle, "_FSL",
  					    fan->fps[state].control);
  	if (ACPI_FAILURE(status)) {
  		dev_dbg(&device->dev, "Failed to set state by _FSL\n");
  		return status;
  	}
  
  	return 0;
  }
  
  static int
  fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
  {
  	struct acpi_device *device = cdev->devdata;
  	struct acpi_fan *fan = acpi_driver_data(device);
  
  	if (fan->acpi4)
  		return fan_set_state_acpi4(device, state);
  	else
  		return fan_set_state(device, state);
  }
  
  static const struct thermal_cooling_device_ops fan_cooling_ops = {
  	.get_max_state = fan_get_max_state,
  	.get_cur_state = fan_get_cur_state,
  	.set_cur_state = fan_set_cur_state,
  };
  
  /* --------------------------------------------------------------------------
   *                               Driver Interface
   * --------------------------------------------------------------------------
  */
  
  static bool acpi_fan_is_acpi4(struct acpi_device *device)
  {
  	return acpi_has_method(device->handle, "_FIF") &&
  	       acpi_has_method(device->handle, "_FPS") &&
  	       acpi_has_method(device->handle, "_FSL") &&
  	       acpi_has_method(device->handle, "_FST");
  }
  
  static int acpi_fan_get_fif(struct acpi_device *device)
  {
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	struct acpi_fan *fan = acpi_driver_data(device);
  	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
  	struct acpi_buffer fif = { sizeof(fan->fif), &fan->fif };
  	union acpi_object *obj;
  	acpi_status status;
  
  	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
  	if (ACPI_FAILURE(status))
  		return status;
  
  	obj = buffer.pointer;
  	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
  		dev_err(&device->dev, "Invalid _FIF data\n");
  		status = -EINVAL;
  		goto err;
  	}
  
  	status = acpi_extract_package(obj, &format, &fif);
  	if (ACPI_FAILURE(status)) {
  		dev_err(&device->dev, "Invalid _FIF element\n");
  		status = -EINVAL;
  	}
  
  err:
  	kfree(obj);
  	return status;
  }
  
  static int acpi_fan_speed_cmp(const void *a, const void *b)
  {
  	const struct acpi_fan_fps *fps1 = a;
  	const struct acpi_fan_fps *fps2 = b;
  	return fps1->speed - fps2->speed;
  }
  
  static int acpi_fan_get_fps(struct acpi_device *device)
  {
  	struct acpi_fan *fan = acpi_driver_data(device);
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	union acpi_object *obj;
  	acpi_status status;
  	int i;
  
  	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
  	if (ACPI_FAILURE(status))
  		return status;
  
  	obj = buffer.pointer;
  	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
  		dev_err(&device->dev, "Invalid _FPS data\n");
  		status = -EINVAL;
  		goto err;
  	}
  
  	fan->fps_count = obj->package.count - 1; /* minus revision field */
  	fan->fps = devm_kzalloc(&device->dev,
  				fan->fps_count * sizeof(struct acpi_fan_fps),
  				GFP_KERNEL);
  	if (!fan->fps) {
  		dev_err(&device->dev, "Not enough memory\n");
  		status = -ENOMEM;
  		goto err;
  	}
  	for (i = 0; i < fan->fps_count; i++) {
  		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
  		struct acpi_buffer fps = { sizeof(fan->fps[i]), &fan->fps[i] };
  		status = acpi_extract_package(&obj->package.elements[i + 1],
  					      &format, &fps);
  		if (ACPI_FAILURE(status)) {
  			dev_err(&device->dev, "Invalid _FPS element\n");
  			break;
  		}
  	}
  
  	/* sort the state array according to fan speed in increase order */
  	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
  	     acpi_fan_speed_cmp, NULL);
  
  err:
  	kfree(obj);
  	return status;
  }
  
  static int acpi_fan_probe(struct platform_device *pdev)
  {
  	int result = 0;
  	struct thermal_cooling_device *cdev;
  	struct acpi_fan *fan;
  	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
  	char *name;
  
  	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
  	if (!fan) {
  		dev_err(&device->dev, "No memory for fan\n");
  		return -ENOMEM;
  	}
  	device->driver_data = fan;
  	platform_set_drvdata(pdev, fan);
  
  	if (acpi_fan_is_acpi4(device)) {
  		if (acpi_fan_get_fif(device) || acpi_fan_get_fps(device))
  			goto end;
  		fan->acpi4 = true;
  	} else {
  		result = acpi_device_update_power(device, NULL);
  		if (result) {
  			dev_err(&device->dev, "Failed to set initial power state\n");
  			goto end;
  		}
  	}
  
  	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
  		name = "Fan";
  	else
  		name = acpi_device_bid(device);
  
  	cdev = thermal_cooling_device_register(name, device,
  						&fan_cooling_ops);
  	if (IS_ERR(cdev)) {
  		result = PTR_ERR(cdev);
  		goto end;
  	}
  
  	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
  
  	fan->cdev = cdev;
  	result = sysfs_create_link(&pdev->dev.kobj,
  				   &cdev->device.kobj,
  				   "thermal_cooling");
  	if (result)
  		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
  
  	result = sysfs_create_link(&cdev->device.kobj,
  				   &pdev->dev.kobj,
  				   "device");
  	if (result)
  		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
  
  end:
  	return result;
  }
  
  static int acpi_fan_remove(struct platform_device *pdev)
  {
  	struct acpi_fan *fan = platform_get_drvdata(pdev);
  
  	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
  	sysfs_remove_link(&fan->cdev->device.kobj, "device");
  	thermal_cooling_device_unregister(fan->cdev);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int acpi_fan_suspend(struct device *dev)
  {
  	struct acpi_fan *fan = dev_get_drvdata(dev);
  	if (fan->acpi4)
  		return 0;
  
  	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
  
  	return AE_OK;
  }
  
  static int acpi_fan_resume(struct device *dev)
  {
  	int result;
  	struct acpi_fan *fan = dev_get_drvdata(dev);
  
  	if (fan->acpi4)
  		return 0;
  
  	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
  	if (result)
  		dev_err(dev, "Error updating fan power state\n");
  
  	return result;
  }
  #endif
  
  module_platform_driver(acpi_fan_driver);
  