headers: remove sched.h from interrupt.h
[safe/jmp/linux-2.6] / drivers / rtc / interface.c
index a4f56e9..a0c8162 100644 (file)
@@ -12,6 +12,7 @@
 */
 
 #include <linux/rtc.h>
+#include <linux/sched.h>
 #include <linux/log2.h>
 
 int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
@@ -20,7 +21,7 @@ int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
 
        err = mutex_lock_interruptible(&rtc->ops_lock);
        if (err)
-               return -EBUSY;
+               return err;
 
        if (!rtc->ops)
                err = -ENODEV;
@@ -46,14 +47,19 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 
        err = mutex_lock_interruptible(&rtc->ops_lock);
        if (err)
-               return -EBUSY;
+               return err;
 
        if (!rtc->ops)
                err = -ENODEV;
-       else if (!rtc->ops->set_time)
-               err = -EINVAL;
-       else
+       else if (rtc->ops->set_time)
                err = rtc->ops->set_time(rtc->dev.parent, tm);
+       else if (rtc->ops->set_mmss) {
+               unsigned long secs;
+               err = rtc_tm_to_time(tm, &secs);
+               if (err == 0)
+                       err = rtc->ops->set_mmss(rtc->dev.parent, secs);
+       } else
+               err = -EINVAL;
 
        mutex_unlock(&rtc->ops_lock);
        return err;
@@ -66,7 +72,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
 
        err = mutex_lock_interruptible(&rtc->ops_lock);
        if (err)
-               return -EBUSY;
+               return err;
 
        if (!rtc->ops)
                err = -ENODEV;
@@ -106,7 +112,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *al
 
        err = mutex_lock_interruptible(&rtc->ops_lock);
        if (err)
-               return -EBUSY;
+               return err;
 
        if (rtc->ops == NULL)
                err = -ENODEV;
@@ -126,12 +132,25 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
        int err;
        struct rtc_time before, now;
        int first_time = 1;
+       unsigned long t_now, t_alm;
+       enum { none, day, month, year } missing = none;
+       unsigned days;
 
-       /* The lower level RTC driver may not be capable of filling
-        * in all fields of the rtc_time struct (eg. rtc-cmos),
-        * and so might instead return -1 in some fields.
-        * We deal with that here by grabbing a current RTC timestamp
-        * and using values from that for any missing (-1) values.
+       /* The lower level RTC driver may return -1 in some fields,
+        * creating invalid alarm->time values, for reasons like:
+        *
+        *   - The hardware may not be capable of filling them in;
+        *     many alarms match only on time-of-day fields, not
+        *     day/month/year calendar data.
+        *
+        *   - Some hardware uses illegal values as "wildcard" match
+        *     values, which non-Linux firmware (like a BIOS) may try
+        *     to set up as e.g. "alarm 15 minutes after each hour".
+        *     Linux uses only oneshot alarms.
+        *
+        * When we see that here, we deal with it by using values from
+        * a current RTC timestamp for any missing (-1) values.  The
+        * RTC driver prevents "periodic alarm" modes.
         *
         * But this can be racey, because some fields of the RTC timestamp
         * may have wrapped in the interval since we read the RTC alarm,
@@ -174,6 +193,10 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
                if (!alarm->enabled)
                        return 0;
 
+               /* full-function RTCs won't have such missing fields */
+               if (rtc_valid_tm(&alarm->time) == 0)
+                       return 0;
+
                /* get the "after" timestamp, to detect wrapped fields */
                err = rtc_read_time(rtc, &now);
                if (err < 0)
@@ -183,22 +206,85 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
        } while (   before.tm_min   != now.tm_min
                 || before.tm_hour  != now.tm_hour
                 || before.tm_mon   != now.tm_mon
-                || before.tm_year  != now.tm_year
-                || before.tm_isdst != now.tm_isdst);
+                || before.tm_year  != now.tm_year);
 
-       /* Fill in any missing alarm fields using the timestamp */
+       /* Fill in the missing alarm fields using the timestamp; we
+        * know there's at least one since alarm->time is invalid.
+        */
        if (alarm->time.tm_sec == -1)
                alarm->time.tm_sec = now.tm_sec;
        if (alarm->time.tm_min == -1)
                alarm->time.tm_min = now.tm_min;
        if (alarm->time.tm_hour == -1)
                alarm->time.tm_hour = now.tm_hour;
-       if (alarm->time.tm_mday == -1)
+
+       /* For simplicity, only support date rollover for now */
+       if (alarm->time.tm_mday == -1) {
                alarm->time.tm_mday = now.tm_mday;
-       if (alarm->time.tm_mon == -1)
+               missing = day;
+       }
+       if (alarm->time.tm_mon == -1) {
                alarm->time.tm_mon = now.tm_mon;
-       if (alarm->time.tm_year == -1)
+               if (missing == none)
+                       missing = month;
+       }
+       if (alarm->time.tm_year == -1) {
                alarm->time.tm_year = now.tm_year;
+               if (missing == none)
+                       missing = year;
+       }
+
+       /* with luck, no rollover is needed */
+       rtc_tm_to_time(&now, &t_now);
+       rtc_tm_to_time(&alarm->time, &t_alm);
+       if (t_now < t_alm)
+               goto done;
+
+       switch (missing) {
+
+       /* 24 hour rollover ... if it's now 10am Monday, an alarm that
+        * that will trigger at 5am will do so at 5am Tuesday, which
+        * could also be in the next month or year.  This is a common
+        * case, especially for PCs.
+        */
+       case day:
+               dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
+               t_alm += 24 * 60 * 60;
+               rtc_time_to_tm(t_alm, &alarm->time);
+               break;
+
+       /* Month rollover ... if it's the 31th, an alarm on the 3rd will
+        * be next month.  An alarm matching on the 30th, 29th, or 28th
+        * may end up in the month after that!  Many newer PCs support
+        * this type of alarm.
+        */
+       case month:
+               dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
+               do {
+                       if (alarm->time.tm_mon < 11)
+                               alarm->time.tm_mon++;
+                       else {
+                               alarm->time.tm_mon = 0;
+                               alarm->time.tm_year++;
+                       }
+                       days = rtc_month_days(alarm->time.tm_mon,
+                                       alarm->time.tm_year);
+               } while (days < alarm->time.tm_mday);
+               break;
+
+       /* Year rollover ... easy except for leap years! */
+       case year:
+               dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
+               do {
+                       alarm->time.tm_year++;
+               } while (rtc_valid_tm(&alarm->time) != 0);
+               break;
+
+       default:
+               dev_warn(&rtc->dev, "alarm rollover not handled\n");
+       }
+
+done:
        return 0;
 }
 EXPORT_SYMBOL_GPL(rtc_read_alarm);
@@ -213,7 +299,7 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 
        err = mutex_lock_interruptible(&rtc->ops_lock);
        if (err)
-               return -EBUSY;
+               return err;
 
        if (!rtc->ops)
                err = -ENODEV;
@@ -227,44 +313,103 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 }
 EXPORT_SYMBOL_GPL(rtc_set_alarm);
 
+int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
+{
+       int err = mutex_lock_interruptible(&rtc->ops_lock);
+       if (err)
+               return err;
+
+       if (!rtc->ops)
+               err = -ENODEV;
+       else if (!rtc->ops->alarm_irq_enable)
+               err = -EINVAL;
+       else
+               err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
+
+       mutex_unlock(&rtc->ops_lock);
+       return err;
+}
+EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
+
+int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
+{
+       int err = mutex_lock_interruptible(&rtc->ops_lock);
+       if (err)
+               return err;
+
+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+       if (enabled == 0 && rtc->uie_irq_active) {
+               mutex_unlock(&rtc->ops_lock);
+               return rtc_dev_update_irq_enable_emul(rtc, enabled);
+       }
+#endif
+
+       if (!rtc->ops)
+               err = -ENODEV;
+       else if (!rtc->ops->update_irq_enable)
+               err = -EINVAL;
+       else
+               err = rtc->ops->update_irq_enable(rtc->dev.parent, enabled);
+
+       mutex_unlock(&rtc->ops_lock);
+
+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+       /*
+        * Enable emulation if the driver did not provide
+        * the update_irq_enable function pointer or if returned
+        * -EINVAL to signal that it has been configured without
+        * interrupts or that are not available at the moment.
+        */
+       if (err == -EINVAL)
+               err = rtc_dev_update_irq_enable_emul(rtc, enabled);
+#endif
+       return err;
+}
+EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
+
 /**
  * rtc_update_irq - report RTC periodic, alarm, and/or update irqs
  * @rtc: the rtc device
  * @num: how many irqs are being reported (usually one)
  * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
- * Context: in_interrupt(), irqs blocked
+ * Context: any
  */
 void rtc_update_irq(struct rtc_device *rtc,
                unsigned long num, unsigned long events)
 {
-       spin_lock(&rtc->irq_lock);
+       unsigned long flags;
+
+       spin_lock_irqsave(&rtc->irq_lock, flags);
        rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
-       spin_unlock(&rtc->irq_lock);
+       spin_unlock_irqrestore(&rtc->irq_lock, flags);
 
-       spin_lock(&rtc->irq_task_lock);
+       spin_lock_irqsave(&rtc->irq_task_lock, flags);
        if (rtc->irq_task)
                rtc->irq_task->func(rtc->irq_task->private_data);
-       spin_unlock(&rtc->irq_task_lock);
+       spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
 
        wake_up_interruptible(&rtc->irq_queue);
        kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
 }
 EXPORT_SYMBOL_GPL(rtc_update_irq);
 
+static int __rtc_match(struct device *dev, void *data)
+{
+       char *name = (char *)data;
+
+       if (strcmp(dev_name(dev), name) == 0)
+               return 1;
+       return 0;
+}
+
 struct rtc_device *rtc_class_open(char *name)
 {
        struct device *dev;
        struct rtc_device *rtc = NULL;
 
-       down(&rtc_class->sem);
-       list_for_each_entry(dev, &rtc_class->devices, node) {
-               if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0) {
-                       dev = get_device(dev);
-                       if (dev)
-                               rtc = to_rtc_device(dev);
-                       break;
-               }
-       }
+       dev = class_find_device(rtc_class, NULL, name, __rtc_match);
+       if (dev)
+               rtc = to_rtc_device(dev);
 
        if (rtc) {
                if (!try_module_get(rtc->owner)) {
@@ -272,7 +417,6 @@ struct rtc_device *rtc_class_open(char *name)
                        rtc = NULL;
                }
        }
-       up(&rtc_class->sem);
 
        return rtc;
 }
@@ -293,7 +437,7 @@ int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
                return -EINVAL;
 
        /* Cannot register while the char dev is in use */
-       if (test_and_set_bit(RTC_DEV_BUSY, &rtc->flags))
+       if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
                return -EBUSY;
 
        spin_lock_irq(&rtc->irq_task_lock);
@@ -303,7 +447,7 @@ int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
        }
        spin_unlock_irq(&rtc->irq_task_lock);
 
-       clear_bit(RTC_DEV_BUSY, &rtc->flags);
+       clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
 
        return retval;
 }
@@ -368,9 +512,6 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
        if (rtc->ops->irq_set_freq == NULL)
                return -ENXIO;
 
-       if (!is_power_of_2(freq))
-               return -EINVAL;
-
        spin_lock_irqsave(&rtc->irq_task_lock, flags);
        if (rtc->irq_task != NULL && task == NULL)
                err = -EBUSY;