rtc/mc13783: implement alarm

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: Valentin Longchamp <valentin.longchamp@epfl.ch>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 172 insertions, 13 deletions

diff --git a/drivers/rtc/rtc-mc13783.c b/drivers/rtc/rtc-mc13783.c
index 6a36201178a8..d60c81b7b693 100644
--- a/drivers/rtc/rtc-mc13783.c
+++ b/drivers/rtc/rtc-mc13783.c
@@ -28,6 +28,34 @@ struct mc13783_rtc {
         int valid;
 };
 
+static int mc13783_rtc_irq_enable_unlocked(struct device *dev,
+                unsigned int enabled, int irq)
+{
+        struct mc13783_rtc *priv = dev_get_drvdata(dev);
+        int (*func)(struct mc13783 *mc13783, int irq);
+
+        if (!priv->valid)
+                return -ENODATA;
+
+        func = enabled ? mc13783_irq_unmask : mc13783_irq_mask;
+        return func(priv->mc13783, irq);
+}
+
+static int mc13783_rtc_irq_enable(struct device *dev,
+                unsigned int enabled, int irq)
+{
+        struct mc13783_rtc *priv = dev_get_drvdata(dev);
+        int ret;
+
+        mc13783_lock(priv->mc13783);
+
+        ret = mc13783_rtc_irq_enable_unlocked(dev, enabled, irq);
+
+        mc13783_unlock(priv->mc13783);
+
+        return ret;
+}
+
 static int mc13783_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
         struct mc13783_rtc *priv = dev_get_drvdata(dev);
@@ -78,6 +106,7 @@ static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs)
 {
         struct mc13783_rtc *priv = dev_get_drvdata(dev);
         unsigned int seconds, days;
+        unsigned int alarmseconds;
         int ret;
 
         seconds = secs % 86400;
@@ -86,7 +115,22 @@ static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs)
         mc13783_lock(priv->mc13783);
 
         /*
-         * first write seconds=0 to prevent a day switch between writing days
+         * temporarily invalidate alarm to prevent triggering it when the day is
+         * already updated while the time isn't yet.
+         */
+        ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTODA, &alarmseconds);
+        if (unlikely(ret))
+                goto out;
+
+        if (alarmseconds < 86400) {
+                ret = mc13783_reg_write(priv->mc13783,
+                                MC13783_RTCTODA, 0x1ffff);
+                if (unlikely(ret))
+                        goto out;
+        }
+
+        /*
+         * write seconds=0 to prevent a day switch between writing days
          * and seconds below
          */
         ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, 0);
@@ -101,6 +145,14 @@ static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs)
         if (unlikely(ret))
                 goto out;
 
+        /* restore alarm */
+        if (alarmseconds < 86400) {
+                ret = mc13783_reg_write(priv->mc13783,
+                                MC13783_RTCTODA, alarmseconds);
+                if (unlikely(ret))
+                        goto out;
+        }
+
         ret = mc13783_irq_ack(priv->mc13783, MC13783_IRQ_RTCRST);
         if (unlikely(ret))
                 goto out;
@@ -114,6 +166,107 @@ out:
         return ret;
 }
 
+static int mc13783_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        struct mc13783_rtc *priv = dev_get_drvdata(dev);
+        unsigned seconds, days;
+        unsigned long s1970;
+        int enabled, pending;
+        int ret;
+
+        mc13783_lock(priv->mc13783);
+
+        ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTODA, &seconds);
+        if (unlikely(ret))
+                goto out;
+        if (seconds >= 86400) {
+                ret = -ENODATA;
+                goto out;
+        }
+
+        ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days);
+        if (unlikely(ret))
+                goto out;
+
+        ret = mc13783_irq_status(priv->mc13783, MC13783_IRQ_TODA,
+                        &enabled, &pending);
+
+out:
+        mc13783_unlock(priv->mc13783);
+
+        if (ret)
+                return ret;
+
+        alarm->enabled = enabled;
+        alarm->pending = pending;
+
+        s1970 = days * 86400 + seconds;
+
+        rtc_time_to_tm(s1970, &alarm->time);
+        dev_dbg(dev, "%s: %lu\n", __func__, s1970);
+
+        return 0;
+}
+
+static int mc13783_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        struct mc13783_rtc *priv = dev_get_drvdata(dev);
+        unsigned long s1970;
+        unsigned seconds, days;
+        int ret;
+
+        mc13783_lock(priv->mc13783);
+
+        /* disable alarm to prevent false triggering */
+        ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, 0x1ffff);
+        if (unlikely(ret))
+                goto out;
+
+        ret = mc13783_irq_ack(priv->mc13783, MC13783_IRQ_TODA);
+        if (unlikely(ret))
+                goto out;
+
+        ret = rtc_tm_to_time(&alarm->time, &s1970);
+        if (unlikely(ret))
+                goto out;
+
+        dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
+                        s1970);
+
+        ret = mc13783_rtc_irq_enable_unlocked(dev, alarm->enabled,
+                        MC13783_IRQ_TODA);
+        if (unlikely(ret))
+                goto out;
+
+        seconds = s1970 % 86400;
+        days = s1970 / 86400;
+
+        ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAYA, days);
+        if (unlikely(ret))
+                goto out;
+
+        ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, seconds);
+
+out:
+        mc13783_unlock(priv->mc13783);
+
+        return ret;
+}
+
+static irqreturn_t mc13783_rtc_alarm_handler(int irq, void *dev)
+{
+        struct mc13783_rtc *priv = dev;
+        struct mc13783 *mc13783 = priv->mc13783;
+
+        dev_dbg(&priv->rtc->dev, "Alarm\n");
+
+        rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
+
+        mc13783_irq_ack(mc13783, irq);
+
+        return IRQ_HANDLED;
+}
+
 static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev)
 {
         struct mc13783_rtc *priv = dev;
@@ -131,24 +284,21 @@ static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev)
 static int mc13783_rtc_update_irq_enable(struct device *dev,
                 unsigned int enabled)
 {
-        struct mc13783_rtc *priv = dev_get_drvdata(dev);
-        int ret = -ENODATA;
-
-        mc13783_lock(priv->mc13783);
-        if (!priv->valid)
-                goto out;
-
-        ret = (enabled ? mc13783_irq_unmask : mc13783_irq_mask)(priv->mc13783,
-                        MC13783_IRQ_1HZ);
-out:
-        mc13783_unlock(priv->mc13783);
+        return mc13783_rtc_irq_enable(dev, enabled, MC13783_IRQ_1HZ);
+}
 
-        return ret;
+static int mc13783_rtc_alarm_irq_enable(struct device *dev,
+                unsigned int enabled)
+{
+        return mc13783_rtc_irq_enable(dev, enabled, MC13783_IRQ_TODA);
 }
 
 static const struct rtc_class_ops mc13783_rtc_ops = {
         .read_time = mc13783_rtc_read_time,
         .set_mmss = mc13783_rtc_set_mmss,
+        .read_alarm = mc13783_rtc_read_alarm,
+        .set_alarm = mc13783_rtc_set_alarm,
+        .alarm_irq_enable = mc13783_rtc_alarm_irq_enable,
         .update_irq_enable = mc13783_rtc_update_irq_enable,
 };
 
@@ -197,11 +347,19 @@ static int __devinit mc13783_rtc_probe(struct platform_device *pdev)
         if (ret)
                 goto err_update_irq_request;
 
+        ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_TODA,
+                        mc13783_rtc_alarm_handler, DRIVER_NAME, priv);
+        if (ret)
+                goto err_alarm_irq_request;
+
         priv->rtc = rtc_device_register(pdev->name,
                         &pdev->dev, &mc13783_rtc_ops, THIS_MODULE);
         if (IS_ERR(priv->rtc)) {
                 ret = PTR_ERR(priv->rtc);
 
+                mc13783_irq_free(priv->mc13783, MC13783_IRQ_TODA, priv);
+err_alarm_irq_request:
+
                 mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv);
 err_update_irq_request:
 
@@ -227,6 +385,7 @@ static int __devexit mc13783_rtc_remove(struct platform_device *pdev)
 
         rtc_device_unregister(priv->rtc);
 
+        mc13783_irq_free(priv->mc13783, MC13783_IRQ_TODA, priv);
         mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv);
         mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv);