1/*
  2 *  acpi_fan.c - ACPI Fan Driver ($Revision: 29 $)
  3 *
  4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
  5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  6 *
  7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  8 *
  9 *  This program is free software; you can redistribute it and/or modify
 10 *  it under the terms of the GNU General Public License as published by
 11 *  the Free Software Foundation; either version 2 of the License, or (at
 12 *  your option) any later version.
 13 *
 14 *  This program is distributed in the hope that it will be useful, but
 15 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 17 *  General Public License for more details.
 18 *
 19 *  You should have received a copy of the GNU General Public License along
 20 *  with this program; if not, write to the Free Software Foundation, Inc.,
 21 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 22 *
 23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 24 */
 25
 26#include <linux/kernel.h>
 27#include <linux/module.h>
 28#include <linux/init.h>
 29#include <linux/types.h>
 30#include <asm/uaccess.h>
 31#include <linux/thermal.h>
 32#include <acpi/acpi_bus.h>
 33#include <acpi/acpi_drivers.h>
 34
 35#define PREFIX "ACPI: "
 36
 37#define ACPI_FAN_CLASS			"fan"
 38#define ACPI_FAN_FILE_STATE		"state"
 39
 40#define _COMPONENT		ACPI_FAN_COMPONENT
 41ACPI_MODULE_NAME("fan");
 42
 43MODULE_AUTHOR("Paul Diefenbaugh");
 44MODULE_DESCRIPTION("ACPI Fan Driver");
 45MODULE_LICENSE("GPL");
 46
 47static int acpi_fan_add(struct acpi_device *device);
 48static int acpi_fan_remove(struct acpi_device *device, int type);
 49static int acpi_fan_suspend(struct acpi_device *device, pm_message_t state);
 50static int acpi_fan_resume(struct acpi_device *device);
 51
 52static const struct acpi_device_id fan_device_ids[] = {
 53	{"PNP0C0B", 0},
 54	{"", 0},
 55};
 56MODULE_DEVICE_TABLE(acpi, fan_device_ids);
 57
 58static struct acpi_driver acpi_fan_driver = {
 59	.name = "fan",
 60	.class = ACPI_FAN_CLASS,
 61	.ids = fan_device_ids,
 62	.ops = {
 63		.add = acpi_fan_add,
 64		.remove = acpi_fan_remove,
 65		.suspend = acpi_fan_suspend,
 66		.resume = acpi_fan_resume,
 67		},
 68};
 69
 70/* thermal cooling device callbacks */
 71static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
 72			     *state)
 73{
 74	/* ACPI fan device only support two states: ON/OFF */
 75	*state = 1;
 76	return 0;
 77}
 78
 79static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
 80			     *state)
 81{
 82	struct acpi_device *device = cdev->devdata;
 83	int result;
 84	int acpi_state;
 85
 86	if (!device)
 87		return -EINVAL;
 88
 89	result = acpi_bus_update_power(device->handle, &acpi_state);
 90	if (result)
 91		return result;
 92
 93	*state = (acpi_state == ACPI_STATE_D3 ? 0 :
 94		 (acpi_state == ACPI_STATE_D0 ? 1 : -1));
 95	return 0;
 96}
 97
 98static int
 99fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
100{
101	struct acpi_device *device = cdev->devdata;
102	int result;
103
104	if (!device || (state != 0 && state != 1))
105		return -EINVAL;
106
107	result = acpi_bus_set_power(device->handle,
108				state ? ACPI_STATE_D0 : ACPI_STATE_D3);
109
110	return result;
111}
112
113static const struct thermal_cooling_device_ops fan_cooling_ops = {
114	.get_max_state = fan_get_max_state,
115	.get_cur_state = fan_get_cur_state,
116	.set_cur_state = fan_set_cur_state,
117};
118
119/* --------------------------------------------------------------------------
120                                 Driver Interface
121   -------------------------------------------------------------------------- */
122
123static int acpi_fan_add(struct acpi_device *device)
124{
125	int result = 0;
126	struct thermal_cooling_device *cdev;
127
128	if (!device)
129		return -EINVAL;
130
131	strcpy(acpi_device_name(device), "Fan");
132	strcpy(acpi_device_class(device), ACPI_FAN_CLASS);
133
134	result = acpi_bus_update_power(device->handle, NULL);
135	if (result) {
136		printk(KERN_ERR PREFIX "Setting initial power state\n");
137		goto end;
138	}
139
140	cdev = thermal_cooling_device_register("Fan", device,
141						&fan_cooling_ops);
142	if (IS_ERR(cdev)) {
143		result = PTR_ERR(cdev);
144		goto end;
145	}
146
147	dev_dbg(&device->dev, "registered as cooling_device%d\n", cdev->id);
148
149	device->driver_data = cdev;
150	result = sysfs_create_link(&device->dev.kobj,
151				   &cdev->device.kobj,
152				   "thermal_cooling");
153	if (result)
154		dev_err(&device->dev, "Failed to create sysfs link "
155			"'thermal_cooling'\n");
156
157	result = sysfs_create_link(&cdev->device.kobj,
158				   &device->dev.kobj,
159				   "device");
160	if (result)
161		dev_err(&device->dev, "Failed to create sysfs link "
162			"'device'\n");
163
164	printk(KERN_INFO PREFIX "%s [%s] (%s)\n",
165	       acpi_device_name(device), acpi_device_bid(device),
166	       !device->power.state ? "on" : "off");
167
168      end:
169	return result;
170}
171
172static int acpi_fan_remove(struct acpi_device *device, int type)
173{
174	struct thermal_cooling_device *cdev = acpi_driver_data(device);
175
176	if (!device || !cdev)
177		return -EINVAL;
178
179	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
180	sysfs_remove_link(&cdev->device.kobj, "device");
181	thermal_cooling_device_unregister(cdev);
182
183	return 0;
184}
185
186static int acpi_fan_suspend(struct acpi_device *device, pm_message_t state)
187{
188	if (!device)
189		return -EINVAL;
190
191	acpi_bus_set_power(device->handle, ACPI_STATE_D0);
192
193	return AE_OK;
194}
195
196static int acpi_fan_resume(struct acpi_device *device)
197{
198	int result;
199
200	if (!device)
201		return -EINVAL;
202
203	result = acpi_bus_update_power(device->handle, NULL);
204	if (result)
205		printk(KERN_ERR PREFIX "Error updating fan power state\n");
206
207	return result;
208}
209
210static int __init acpi_fan_init(void)
211{
212	int result = 0;
213
214	result = acpi_bus_register_driver(&acpi_fan_driver);
215	if (result < 0)
216		return -ENODEV;
217
218	return 0;
219}
220
221static void __exit acpi_fan_exit(void)
222{
223
224	acpi_bus_unregister_driver(&acpi_fan_driver);
225
226	return;
227}
228
229module_init(acpi_fan_init);
230module_exit(acpi_fan_exit);