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authorJohn Stultz <john.stultz@linaro.org>2011-07-14 18:35:13 -0700
committerJohn Stultz <john.stultz@linaro.org>2011-08-10 14:55:30 -0700
commit8bc0dafb5cf38a19484dfb16e2c6d29e85820046 (patch)
treeaf2f0000b9cc95567cc4bab5966ef6fd887c6f1f /kernel/time
parent9082c465a5403f4a98734193e078552991a2e283 (diff)
alarmtimers: Rework RTC device selection using class interface
This allows cleaner detection of the RTC device being registered, rather then probing any time someone calls alarmtimer_get_rtcdev. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'kernel/time')
-rw-r--r--kernel/time/alarmtimer.c78
1 files changed, 40 insertions, 38 deletions
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index bdb7342b6896..154d5563ab1b 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -53,27 +53,6 @@ static struct rtc_device *rtcdev;
static DEFINE_SPINLOCK(rtcdev_lock);
/**
- * has_wakealarm - check rtc device has wakealarm ability
- * @dev: current device
- * @name_ptr: name to be returned
- *
- * This helper function checks to see if the rtc device can wake
- * from suspend.
- */
-static int has_wakealarm(struct device *dev, void *name_ptr)
-{
- struct rtc_device *candidate = to_rtc_device(dev);
-
- if (!candidate->ops->set_alarm)
- return 0;
- if (!device_may_wakeup(candidate->dev.parent))
- return 0;
-
- *(const char **)name_ptr = dev_name(dev);
- return 1;
-}
-
-/**
* alarmtimer_get_rtcdev - Return selected rtcdevice
*
* This function returns the rtc device to use for wakealarms.
@@ -82,37 +61,58 @@ static int has_wakealarm(struct device *dev, void *name_ptr)
*/
static struct rtc_device *alarmtimer_get_rtcdev(void)
{
- struct device *dev;
- char *str;
unsigned long flags;
struct rtc_device *ret;
spin_lock_irqsave(&rtcdev_lock, flags);
- if (!rtcdev) {
- /* Find an rtc device and init the rtc_timer */
- dev = class_find_device(rtc_class, NULL, &str, has_wakealarm);
- /* If we have a device then str is valid. See has_wakealarm() */
- if (dev) {
- rtcdev = rtc_class_open(str);
- /*
- * Drop the reference we got in class_find_device,
- * rtc_open takes its own.
- */
- put_device(dev);
- rtc_timer_init(&rtctimer, NULL, NULL);
- }
- }
ret = rtcdev;
spin_unlock_irqrestore(&rtcdev_lock, flags);
return ret;
}
+
+
+static int alarmtimer_rtc_add_device(struct device *dev,
+ struct class_interface *class_intf)
+{
+ unsigned long flags;
+ struct rtc_device *rtc = to_rtc_device(dev);
+
+ if (rtcdev)
+ return -EBUSY;
+
+ if (!rtc->ops->set_alarm)
+ return -1;
+ if (!device_may_wakeup(rtc->dev.parent))
+ return -1;
+
+ spin_lock_irqsave(&rtcdev_lock, flags);
+ if (!rtcdev) {
+ rtcdev = rtc;
+ /* hold a reference so it doesn't go away */
+ get_device(dev);
+ }
+ spin_unlock_irqrestore(&rtcdev_lock, flags);
+ return 0;
+}
+
+static struct class_interface alarmtimer_rtc_interface = {
+ .add_dev = &alarmtimer_rtc_add_device,
+};
+
+static void alarmtimer_rtc_interface_setup(void)
+{
+ alarmtimer_rtc_interface.class = rtc_class;
+ class_interface_register(&alarmtimer_rtc_interface);
+}
#else
#define alarmtimer_get_rtcdev() (0)
#define rtcdev (0)
+#define alarmtimer_rtc_interface_setup()
#endif
+
/**
* alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
* @base: pointer to the base where the timer is being run
@@ -244,7 +244,7 @@ static int alarmtimer_suspend(struct device *dev)
freezer_delta = ktime_set(0, 0);
spin_unlock_irqrestore(&freezer_delta_lock, flags);
- rtc = rtcdev;
+ rtc = alarmtimer_get_rtcdev();
/* If we have no rtcdev, just return */
if (!rtc)
return 0;
@@ -792,6 +792,8 @@ static int __init alarmtimer_init(void)
HRTIMER_MODE_ABS);
alarm_bases[i].timer.function = alarmtimer_fired;
}
+
+ alarmtimer_rtc_interface_setup();
error = platform_driver_register(&alarmtimer_driver);
platform_device_register_simple("alarmtimer", -1, NULL, 0);