Merge branch 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tip/linux-2.6-tip

* 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  RTC: Fix up rtc.txt documentation to reflect changes to generic rtc layer
  RTC: sa1100: Update the sa1100 RTC driver.
  RTC: Fix the cross interrupt issue on rtc-test.
  RTC: Remove UIE and PIE information from the sa1100 driver proc.
  RTC: Include information about UIE and PIE in RTC driver proc.
  RTC: Clean out UIE icotl implementations
  RTC: Cleanup rtc_class_ops->update_irq_enable()
  RTC: Cleanup rtc_class_ops->irq_set_freq()
  RTC: Cleanup rtc_class_ops->irq_set_state
  RTC: Initialize kernel state from RTC

Documentation/rtc.txt

@@ -178,38 +178,29 @@ RTC class framework, but can't be supported by the older driver.
 	setting the longer alarm time and enabling its IRQ using a single
 	request (using the same model as EFI firmware).
 
-    *	RTC_UIE_ON, RTC_UIE_OFF ... if the RTC offers IRQs, it probably
-	also offers update IRQs whenever the "seconds" counter changes.
-	If needed, the RTC framework can emulate this mechanism.
+    *	RTC_UIE_ON, RTC_UIE_OFF ... if the RTC offers IRQs, the RTC framework
+	will emulate this mechanism.
 
-    *	RTC_PIE_ON, RTC_PIE_OFF, RTC_IRQP_SET, RTC_IRQP_READ ... another
-	feature often accessible with an IRQ line is a periodic IRQ, issued
-	at settable frequencies (usually 2^N Hz).
+    *	RTC_PIE_ON, RTC_PIE_OFF, RTC_IRQP_SET, RTC_IRQP_READ ... these icotls
+	are emulated via a kernel hrtimer.
 
 In many cases, the RTC alarm can be a system wake event, used to force
 Linux out of a low power sleep state (or hibernation) back to a fully
 operational state.  For example, a system could enter a deep power saving
 state until it's time to execute some scheduled tasks.
 
-Note that many of these ioctls need not actually be implemented by your
-driver.  The common rtc-dev interface handles many of these nicely if your
-driver returns ENOIOCTLCMD.  Some common examples:
+Note that many of these ioctls are handled by the common rtc-dev interface.
+Some common examples:
 
     *	RTC_RD_TIME, RTC_SET_TIME: the read_time/set_time functions will be
 	called with appropriate values.
 
-    *	RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: the
-	set_alarm/read_alarm functions will be called.
+    *	RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: gets or sets
+	the alarm rtc_timer. May call the set_alarm driver function.
 
-    *	RTC_IRQP_SET, RTC_IRQP_READ: the irq_set_freq function will be called
-	to set the frequency while the framework will handle the read for you
-	since the frequency is stored in the irq_freq member of the rtc_device
-	structure.  Your driver needs to initialize the irq_freq member during
-	init.  Make sure you check the requested frequency is in range of your
-	hardware in the irq_set_freq function.  If it isn't, return -EINVAL.  If
-	you cannot actually change the frequency, do not define irq_set_freq.
+    *	RTC_IRQP_SET, RTC_IRQP_READ: These are emulated by the generic code.
 
-    *	RTC_PIE_ON, RTC_PIE_OFF: the irq_set_state function will be called.
+    *	RTC_PIE_ON, RTC_PIE_OFF: These are also emulated by the generic code.
 
 If all else fails, check out the rtc-test.c driver!
 

drivers/rtc/class.c

@@ -117,6 +117,7 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev,
 					struct module *owner)
 {
 	struct rtc_device *rtc;
+	struct rtc_wkalrm alrm;
 	int id, err;
 
 	if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
@@ -166,6 +167,12 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev,
 	rtc->pie_timer.function = rtc_pie_update_irq;
 	rtc->pie_enabled = 0;
 
+	/* Check to see if there is an ALARM already set in hw */
+	err = __rtc_read_alarm(rtc, &alrm);
+
+	if (!err && !rtc_valid_tm(&alrm.time))
+		rtc_set_alarm(rtc, &alrm);
+
 	strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
 	dev_set_name(&rtc->dev, "rtc%d", id);
 

drivers/rtc/interface.c

@@ -116,6 +116,186 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
 }
 EXPORT_SYMBOL_GPL(rtc_set_mmss);
 
+static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
+{
+	int err;
+
+	err = mutex_lock_interruptible(&rtc->ops_lock);
+	if (err)
+		return err;
+
+	if (rtc->ops == NULL)
+		err = -ENODEV;
+	else if (!rtc->ops->read_alarm)
+		err = -EINVAL;
+	else {
+		memset(alarm, 0, sizeof(struct rtc_wkalrm));
+		err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
+	}
+
+	mutex_unlock(&rtc->ops_lock);
+	return err;
+}
+
+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 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,
+	 * which would lead to us inserting inconsistent values in place
+	 * of the -1 fields.
+	 *
+	 * Reading the alarm and timestamp in the reverse sequence
+	 * would have the same race condition, and not solve the issue.
+	 *
+	 * So, we must first read the RTC timestamp,
+	 * then read the RTC alarm value,
+	 * and then read a second RTC timestamp.
+	 *
+	 * If any fields of the second timestamp have changed
+	 * when compared with the first timestamp, then we know
+	 * our timestamp may be inconsistent with that used by
+	 * the low-level rtc_read_alarm_internal() function.
+	 *
+	 * So, when the two timestamps disagree, we just loop and do
+	 * the process again to get a fully consistent set of values.
+	 *
+	 * This could all instead be done in the lower level driver,
+	 * but since more than one lower level RTC implementation needs it,
+	 * then it's probably best best to do it here instead of there..
+	 */
+
+	/* Get the "before" timestamp */
+	err = rtc_read_time(rtc, &before);
+	if (err < 0)
+		return err;
+	do {
+		if (!first_time)
+			memcpy(&before, &now, sizeof(struct rtc_time));
+		first_time = 0;
+
+		/* get the RTC alarm values, which may be incomplete */
+		err = rtc_read_alarm_internal(rtc, alarm);
+		if (err)
+			return err;
+
+		/* 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)
+			return err;
+
+		/* note that tm_sec is a "don't care" value here: */
+	} 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);
+
+	/* 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;
+
+	/* For simplicity, only support date rollover for now */
+	if (alarm->time.tm_mday == -1) {
+		alarm->time.tm_mday = now.tm_mday;
+		missing = day;
+	}
+	if (alarm->time.tm_mon == -1) {
+		alarm->time.tm_mon = now.tm_mon;
+		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;
+}
+
 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 {
 	int err;

drivers/rtc/rtc-at91rm9200.c

@@ -183,33 +183,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	return 0;
 }
 
-/*
- * Handle commands from user-space
- */
-static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
-			unsigned long arg)
-{
-	int ret = 0;
-
-	pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg);
-
-	/* important:  scrub old status before enabling IRQs */
-	switch (cmd) {
-	case RTC_UIE_OFF:	/* update off */
-		at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
-		break;
-	case RTC_UIE_ON:	/* update on */
-		at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
-		at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
-		break;
-	default:
-		ret = -ENOIOCTLCMD;
-		break;
-	}
-
-	return ret;
-}
-
 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 {
 	pr_debug("%s(): cmd=%08x\n", __func__, enabled);
@@ -269,7 +242,6 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 }
 
 static const struct rtc_class_ops at91_rtc_ops = {
-	.ioctl		= at91_rtc_ioctl,
 	.read_time	= at91_rtc_readtime,
 	.set_time	= at91_rtc_settime,
 	.read_alarm	= at91_rtc_readalarm,

drivers/rtc/rtc-at91sam9.c

@@ -216,33 +216,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	return 0;
 }
 
-/*
- * Handle commands from user-space
- */
-static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
-			unsigned long arg)
-{
-	struct sam9_rtc *rtc = dev_get_drvdata(dev);
-	int ret = 0;
-	u32 mr = rtt_readl(rtc, MR);
-
-	dev_dbg(dev, "ioctl: cmd=%08x, arg=%08lx, mr %08x\n", cmd, arg, mr);
-
-	switch (cmd) {
-	case RTC_UIE_OFF:		/* update off */
-		rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
-		break;
-	case RTC_UIE_ON:		/* update on */
-		rtt_writel(rtc, MR, mr | AT91_RTT_RTTINCIEN);
-		break;
-	default:
-		ret = -ENOIOCTLCMD;
-		break;
-	}
-
-	return ret;
-}
-
 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 {
 	struct sam9_rtc *rtc = dev_get_drvdata(dev);
@@ -303,7 +276,6 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
 }
 
 static const struct rtc_class_ops at91_rtc_ops = {
-	.ioctl		= at91_rtc_ioctl,
 	.read_time	= at91_rtc_readtime,
 	.set_time	= at91_rtc_settime,
 	.read_alarm	= at91_rtc_readalarm,

drivers/rtc/rtc-bfin.c

@@ -240,32 +240,6 @@ static void bfin_rtc_int_set_alarm(struct bfin_rtc *rtc)
 	 */
 	bfin_rtc_int_set(rtc->rtc_alarm.tm_yday == -1 ? RTC_ISTAT_ALARM : RTC_ISTAT_ALARM_DAY);
 }
-static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
-{
-	struct bfin_rtc *rtc = dev_get_drvdata(dev);
-	int ret = 0;
-
-	dev_dbg_stamp(dev);
-
-	bfin_rtc_sync_pending(dev);
-
-	switch (cmd) {
-	case RTC_UIE_ON:
-		dev_dbg_stamp(dev);
-		bfin_rtc_int_set(RTC_ISTAT_SEC);
-		break;
-	case RTC_UIE_OFF:
-		dev_dbg_stamp(dev);
-		bfin_rtc_int_clear(~RTC_ISTAT_SEC);
-		break;
-
-	default:
-		dev_dbg_stamp(dev);
-		ret = -ENOIOCTLCMD;
-	}
-
-	return ret;
-}
 
 static int bfin_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 {
@@ -358,7 +332,6 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
 }
 
 static struct rtc_class_ops bfin_rtc_ops = {
-	.ioctl         = bfin_rtc_ioctl,
 	.read_time     = bfin_rtc_read_time,
 	.set_time      = bfin_rtc_set_time,
 	.read_alarm    = bfin_rtc_read_alarm,