clock/time: add CLOCK_BOOTTIME definition

Change-Id: I1adc0445dcdd8284d11aec44bd67b447b2b0490f
Signed-off-by: chao.an <anchao@xiaomi.com>

include/time.h

@@ -90,6 +90,12 @@
 #  define CLOCK_MONOTONIC  1
 #endif
 
+/* Monotonic system-wide clock that includes time spent in suspension. */
+
+#ifdef CONFIG_CLOCK_MONOTONIC
+#  define CLOCK_BOOTTIME   2
+#endif
+
 /* This is a flag that may be passed to the timer_settime() and
  * clock_nanosleep() functions.
  */

sched/clock/clock_getres.c

@@ -74,6 +74,7 @@ int clock_getres(clockid_t clock_id, struct timespec *res)
 
 #ifdef CONFIG_CLOCK_MONOTONIC
       case CLOCK_MONOTONIC:
+      case CLOCK_BOOTTIME:
 #endif
       case CLOCK_REALTIME:
 
@@ -82,7 +83,8 @@ int clock_getres(clockid_t clock_id, struct timespec *res)
         res->tv_sec  = 0;
         res->tv_nsec = NSEC_PER_TICK;
 
-        sinfo("Returning res=(%d,%d)\n", (int)res->tv_sec, (int)res->tv_nsec);
+        sinfo("Returning res=(%d,%d)\n", (int)res->tv_sec,
+                                         (int)res->tv_nsec);
         break;
     }
 

sched/clock/clock_gettime.c

@@ -88,7 +88,7 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
    * is invoked with a clock_id argument of CLOCK_MONOTONIC."
    */
 
-  if (clock_id == CLOCK_MONOTONIC)
+  if (clock_id == CLOCK_MONOTONIC || clock_id == CLOCK_BOOTTIME)
     {
       /* The the time elapsed since the timer was initialized at power on
        * reset.

sched/timer/timer_create.c

@@ -161,6 +161,7 @@ int timer_create(clockid_t clockid, FAR struct sigevent *evp,
   if (timerid == NULL || (clockid != CLOCK_REALTIME
 #ifdef CONFIG_CLOCK_MONOTONIC
       && clockid != CLOCK_MONOTONIC
+      && clockid != CLOCK_BOOTTIME
 #endif /* CONFIG_CLOCK_MONOTONIC */
       ))
     {