2 * driver.c - driver support
4 * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
8 * This code is licenced under the GPL.
11 #include <linux/mutex.h>
12 #include <linux/module.h>
13 #include <linux/cpuidle.h>
17 struct cpuidle_driver *cpuidle_curr_driver;
18 DEFINE_SPINLOCK(cpuidle_driver_lock);
21 * cpuidle_register_driver - registers a driver
24 int cpuidle_register_driver(struct cpuidle_driver *drv)
29 spin_lock(&cpuidle_driver_lock);
30 if (cpuidle_curr_driver) {
31 spin_unlock(&cpuidle_driver_lock);
34 cpuidle_curr_driver = drv;
35 spin_unlock(&cpuidle_driver_lock);
40 EXPORT_SYMBOL_GPL(cpuidle_register_driver);
43 * cpuidle_unregister_driver - unregisters a driver
46 void cpuidle_unregister_driver(struct cpuidle_driver *drv)
48 if (drv != cpuidle_curr_driver) {
49 WARN(1, "invalid cpuidle_unregister_driver(%s)\n",
54 spin_lock(&cpuidle_driver_lock);
55 cpuidle_curr_driver = NULL;
56 spin_unlock(&cpuidle_driver_lock);
59 EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);