From 8eb7898a9129cadee3bb93438d43ea6e6621eb8c Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Fri, 8 Apr 2016 17:44:24 -0600
Subject: [PATCH] RTC driver:  A PID of zero should mean to notify the calling
 task

---
 drivers/timers/rtc.c       | 24 ++++++++++++++++++++++--
 include/nuttx/timers/rtc.h |  4 ++--
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/timers/rtc.c b/drivers/timers/rtc.c
index 62453c1c20..0b467fde2f 100644
--- a/drivers/timers/rtc.c
+++ b/drivers/timers/rtc.c
@@ -384,13 +384,23 @@ static int rtc_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 
         if (ops->setalarm)
           {
+            pid_t pid;
+
+            /* A PID of zero means to signal the calling task */
+
+            pid = alarminfo->pid;
+            if (pid == 0)
+              {
+                pid = getpid();
+              }
+
             /* Save the signal info to be used to notify the caller when the
              * alarm expires.
              */
 
             upperinfo->active   = true;
             upperinfo->signo    = alarminfo->signo;
-            upperinfo->pid      = alarminfo->pid;
+            upperinfo->pid      = pid;
             upperinfo->sigvalue = alarminfo->sigvalue;
 
             /* Format the alarm info needed by the lower half driver */
@@ -447,13 +457,23 @@ static int rtc_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 
         if (ops->setrelative)
           {
+            pid_t pid;
+
+            /* A PID of zero means to signal the calling task */
+
+            pid = alarminfo->pid;
+            if (pid == 0)
+              {
+                pid = getpid();
+              }
+
             /* Save the signal info to be used to notify the caller when the
              * alarm expires.
              */
 
             upperinfo->active   = true;
             upperinfo->signo    = alarminfo->signo;
-            upperinfo->pid      = alarminfo->pid;
+            upperinfo->pid      = pid;
             upperinfo->sigvalue = alarminfo->sigvalue;
 
             /* Format the alarm info needed by the lower half driver */
diff --git a/include/nuttx/timers/rtc.h b/include/nuttx/timers/rtc.h
index 179779a213..d2345a4dc1 100644
--- a/include/nuttx/timers/rtc.h
+++ b/include/nuttx/timers/rtc.h
@@ -223,7 +223,7 @@ struct rtc_setalarm_s
 {
   uint8_t id;               /* Indicates the alarm to be set */
   uint8_t signo;            /* Signal number for alarm notification */
-  pid_t pid;                /* Identifies task to be notified */
+  pid_t pid;                /* Identifies task to be notified (0=caller) */
   union sigval sigvalue;    /* Data passed with notification */
   struct rtc_time time;     /* Alarm time */
 };
@@ -234,7 +234,7 @@ struct rtc_setrelative_s
 {
   uint8_t id;               /* Indicates the alarm to be set */
   uint8_t signo;            /* Signal number for alarm notification */
-  pid_t pid;                /* Identifies task to be notified */
+  pid_t pid;                /* Identifies task to be notified (0=caller) */
   union sigval sigvalue;    /* Data passed with notification */
   time_t reltime;           /* Relative time in seconds */
 };