linux/drivers/acpi/fan.c
Naresh Bhat 85eb98274f ACPI / fan: Initialize acpi_state variable
Make the following compiler warning go away:

 CC      drivers/acpi/fan.o
drivers/acpi/fan.c: In function ‘fan_get_cur_state’:
drivers/acpi/fan.c:96:9: warning: ‘acpi_state’ may be used uninitialized in this function [-Wuninitialized]

by initializing the local variable acpi_state in fan_get_cur_state().

[rjw: Changelog]
Signed-off-by: Naresh Bhat <naresh.bhat@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-04 13:33:25 +02:00

220 lines
5.5 KiB
C

/*
* 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.
*
* 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.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <asm/uaccess.h>
#include <linux/thermal.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#define PREFIX "ACPI: "
#define ACPI_FAN_CLASS "fan"
#define ACPI_FAN_FILE_STATE "state"
#define _COMPONENT ACPI_FAN_COMPONENT
ACPI_MODULE_NAME("fan");
MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI Fan Driver");
MODULE_LICENSE("GPL");
static int acpi_fan_add(struct acpi_device *device);
static int acpi_fan_remove(struct acpi_device *device);
static const struct acpi_device_id fan_device_ids[] = {
{"PNP0C0B", 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);
#endif
static SIMPLE_DEV_PM_OPS(acpi_fan_pm, acpi_fan_suspend, acpi_fan_resume);
static struct acpi_driver acpi_fan_driver = {
.name = "fan",
.class = ACPI_FAN_CLASS,
.ids = fan_device_ids,
.ops = {
.add = acpi_fan_add,
.remove = acpi_fan_remove,
},
.drv.pm = &acpi_fan_pm,
};
/* thermal cooling device callbacks */
static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
*state)
{
/* ACPI fan device only support two states: ON/OFF */
*state = 1;
return 0;
}
static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
*state)
{
struct acpi_device *device = cdev->devdata;
int result;
int acpi_state = ACPI_STATE_D0;
if (!device)
return -EINVAL;
result = acpi_bus_update_power(device->handle, &acpi_state);
if (result)
return result;
*state = (acpi_state == ACPI_STATE_D3 ? 0 :
(acpi_state == ACPI_STATE_D0 ? 1 : -1));
return 0;
}
static int
fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
{
struct acpi_device *device = cdev->devdata;
int result;
if (!device || (state != 0 && state != 1))
return -EINVAL;
result = acpi_bus_set_power(device->handle,
state ? ACPI_STATE_D0 : ACPI_STATE_D3);
return result;
}
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 int acpi_fan_add(struct acpi_device *device)
{
int result = 0;
struct thermal_cooling_device *cdev;
if (!device)
return -EINVAL;
strcpy(acpi_device_name(device), "Fan");
strcpy(acpi_device_class(device), ACPI_FAN_CLASS);
result = acpi_bus_update_power(device->handle, NULL);
if (result) {
printk(KERN_ERR PREFIX "Setting initial power state\n");
goto end;
}
cdev = thermal_cooling_device_register("Fan", device,
&fan_cooling_ops);
if (IS_ERR(cdev)) {
result = PTR_ERR(cdev);
goto end;
}
dev_dbg(&device->dev, "registered as cooling_device%d\n", cdev->id);
device->driver_data = cdev;
result = sysfs_create_link(&device->dev.kobj,
&cdev->device.kobj,
"thermal_cooling");
if (result)
dev_err(&device->dev, "Failed to create sysfs link "
"'thermal_cooling'\n");
result = sysfs_create_link(&cdev->device.kobj,
&device->dev.kobj,
"device");
if (result)
dev_err(&device->dev, "Failed to create sysfs link "
"'device'\n");
printk(KERN_INFO PREFIX "%s [%s] (%s)\n",
acpi_device_name(device), acpi_device_bid(device),
!device->power.state ? "on" : "off");
end:
return result;
}
static int acpi_fan_remove(struct acpi_device *device)
{
struct thermal_cooling_device *cdev;
if (!device)
return -EINVAL;
cdev = acpi_driver_data(device);
if (!cdev)
return -EINVAL;
sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
sysfs_remove_link(&cdev->device.kobj, "device");
thermal_cooling_device_unregister(cdev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int acpi_fan_suspend(struct device *dev)
{
if (!dev)
return -EINVAL;
acpi_bus_set_power(to_acpi_device(dev)->handle, ACPI_STATE_D0);
return AE_OK;
}
static int acpi_fan_resume(struct device *dev)
{
int result;
if (!dev)
return -EINVAL;
result = acpi_bus_update_power(to_acpi_device(dev)->handle, NULL);
if (result)
printk(KERN_ERR PREFIX "Error updating fan power state\n");
return result;
}
#endif
module_acpi_driver(acpi_fan_driver);