Restore CLOCK_ACTIVETIME

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4009 42af7a65-404d-4744-a932-0658087f49c3

7 files changed, 93 insertions, 6 deletions

diff --git a/nuttx/arch/arm/src/stm32/stm32_rtc.c b/nuttx/arch/arm/src/stm32/stm32_rtc.c
index c9811171c..fc40a61b6 100644
--- a/nuttx/arch/arm/src/stm32/stm32_rtc.c
+++ b/nuttx/arch/arm/src/stm32/stm32_rtc.c
@@ -80,6 +80,18 @@
  * Pre-processor Definitions
  ************************************************************************************/
 /* Configuration ********************************************************************/
+/* In hi-res mode, the RTC operates at 16384Hz.  Overflow interrupts are handled
+ * when the 32-bit RTC counter overflows every 3 days and 43 minutes.  A BKP register
+ * is incremented on each overflow interrupt creating, effectively, a 48-bit RTC
+ * counter.
+ *
+ * In the lo-res mode, the RTC operates at 1Hz.  Overflow interrupts are not handled
+ * (because the next overflow is not expected until the year 2106.
+ *
+ * WARNING:  Overflow interrupts are lost whenever the STM32 is powered down.  The
+ * overflow interrupt may be lost even if the STM32 is powered down only momentarily.
+ * Therefor  hi-res solution is only useful in systems where the power is always on.
+ */
 
 #ifdef CONFIG_RTC_HIRES
 #  ifndef CONFIG_RTC_FREQUENCY
diff --git a/nuttx/configs/README.txt b/nuttx/configs/README.txt
index 6cb302d24..c18bde321 100644
--- a/nuttx/configs/README.txt
+++ b/nuttx/configs/README.txt
@@ -607,6 +607,23 @@ defconfig -- This is a configuration file similar to the Linux
 		  option will enable a limited form of memory mapping that is
 		  implemented by copying whole files into memory.
 
+	RTC
+
+		CONFIG_RTC - Enables general support for a hardware RTC. Specific
+		  architectures may require other specific settings.
+		CONFIG_RTC_HIRES - The typical RTC keeps time to resolution of 1
+		  second, usually supporting a 32-bit time_t value.  In this case,
+		  the RTC is used to "seed" the normal NuttX timer and the
+		  NuttX timer provides for higher resoution time. If CONFIG_RTC_HIRES
+		  is enabled in the NuttX configuration, then the RTC provides higher
+		  resolution time and completely replaces the system timer for purpose of
+		  date and time.
+		  CONFIG_RTC_FREQUENCY - If CONFIG_RTC_HIRES is defined, then the
+		  frequency of the high resolution RTC must be provided.  If CONFIG_RTC_HIRES
+		  is not defined, CONFIG_RTC_FREQUENCY is assumed to be one.
+		CONFIG_RTC_ALARM - Enable if the RTC hardware supports setting of an alarm. 
+		  A callback function will be executed when the alarm goes off
+
 	SPI driver
 
 		CONFIG_SPI_OWNBUS - Set if there is only one active device
diff --git a/nuttx/configs/stm3210e-eval/README.txt b/nuttx/configs/stm3210e-eval/README.txt
index 3f260e9a8..f82c2243b 100755
--- a/nuttx/configs/stm3210e-eval/README.txt
+++ b/nuttx/configs/stm3210e-eval/README.txt
@@ -14,6 +14,7 @@ Contents
   - DFU
   - LEDs
   - Temperature Sensor
+  - RTC
   - STM3210E-EVAL-specific Configuration Options
   - Configurations
 
@@ -264,6 +265,38 @@ commands enumerated in include/nuttx/sensors/lm75.h.  Also read the descriptions
 of the stm32_lm75initialize() and stm32_lm75attach() interfaces in the
 arch/board/board.h file (sames as configs/stm3210e-eval/include/board.h).
 
+RTC
+===
+
+  The STM32 RTC may configured using the following settings.
+
+    CONFIG_RTC - Enables general support for a hardware RTC. Specific
+      architectures may require other specific settings.
+    CONFIG_RTC_HIRES - The typical RTC keeps time to resolution of 1
+      second, usually supporting a 32-bit time_t value.  In this case,
+      the RTC is used to "seed" the normal NuttX timer and the
+      NuttX timer provides for higher resoution time. If CONFIG_RTC_HIRES
+      is enabled in the NuttX configuration, then the RTC provides higher
+      resolution time and completely replaces the system timer for purpose of
+      date and time.
+      CONFIG_RTC_FREQUENCY - If CONFIG_RTC_HIRES is defined, then the
+      frequency of the high resolution RTC must be provided.  If CONFIG_RTC_HIRES
+      is not defined, CONFIG_RTC_FREQUENCY is assumed to be one.
+    CONFIG_RTC_ALARM - Enable if the RTC hardware supports setting of an alarm. 
+      A callback function will be executed when the alarm goes off
+
+  In hi-res mode, the STM32 RTC operates only at 16384Hz.  Overflow interrupts
+  are handled when the 32-bit RTC counter overflows every 3 days and 43 minutes.
+  A BKP register is incremented on each overflow interrupt creating, effectively,
+  a 48-bit RTC counter.
+
+  In the lo-res mode, the RTC operates at 1Hz.  Overflow interrupts are not handled
+  (because the next overflow is not expected until the year 2106.
+
+   WARNING:  Overflow interrupts are lost whenever the STM32 is powered down.  The
+   overflow interrupt may be lost even if the STM32 is powered down only momentarily.
+   Therefore hi-res solution is only useful in systems where the power is always on.
+
 STM3210E-EVAL-specific Configuration Options
 ============================================
 
diff --git a/nuttx/configs/vsn/src/sif.c b/nuttx/configs/vsn/src/sif.c
index 3c304a3b2..e185d8d0d 100644
--- a/nuttx/configs/vsn/src/sif.c
+++ b/nuttx/configs/vsn/src/sif.c
@@ -712,7 +712,7 @@ int sif_main(int argc, char *argv[])
     fprintf(stderr, "%s:\tinit\n\tgpio\tA B\n\tpwr\tval\n", argv[0]);
     
     struct timespec t_active;
-    clock_gettime(CLOCK_REALTIME, &t_active);
+    clock_gettime(CLOCK_ACTIVETIME, &t_active);
     
     fprintf(stderr, "rtc time = %u, active = %u / %u, time / systick = %u / %u\n", 
         up_rtc_time(), t_active.tv_sec, t_active.tv_nsec,
diff --git a/nuttx/include/time.h b/nuttx/include/time.h
index 69b62f4eb..623f9afb2 100644
--- a/nuttx/include/time.h
+++ b/nuttx/include/time.h
@@ -67,12 +67,29 @@
 # define CLOCKS_PER_SEC    (100)
 #endif
 
-/* This is the only clock_id supported by the "Clock and Timer
- * Functions."
+/* CLOCK_REALTIME refers to the standard time source.  For most implementations,
+ * the standard time source is the system timer interrupt.  However, if the
+ * platform supports an RTC, then the standard time source will be the RTC
+ * for the clock_gettime() and clock_settime() interfaces (the system timer
+ * is still the time source for all of the interfaces).
  */
 
 #define CLOCK_REALTIME     0
 
+/* If an RTC is supported, then the non-standard CLOCK_ACTIVETIME is also
+ * supported to manage time based on the system timer interrupt separately from
+ * the RTC.  This may be necessary, for example, in certain cases where the
+ * system timer interrupt has been stopped in low power modes.
+ *
+ * CLOCK_ACTIVETIME is only recognized by clock_gettime() and clock_settime().
+ */
+
+#ifdef CONFIG_RTC
+#  define CLOCK_ACTIVETIME 1
+#else
+#  define CLOCK_ACTIVETIME CLOCK_REALTIME
+#endif
+
 /* This is a flag that may be passed to the timer_settime() function */
 
 #define TIMER_ABSTIME      1
diff --git a/nuttx/sched/clock_gettime.c b/nuttx/sched/clock_gettime.c
index d7707f379..9a84d320f 100644
--- a/nuttx/sched/clock_gettime.c
+++ b/nuttx/sched/clock_gettime.c
@@ -110,12 +110,16 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
    * time clock.
    */
 
+#ifdef CONFIG_RTC
+  if (clock_id == CLOCK_REALTIME || clockid == CLOCK_ACTIVETIME)
+#else
   if (clock_id == CLOCK_REALTIME)
+#endif
     {
       /* Do we have a high-resolution RTC that can provie us with the time? */
 
 #ifdef CONFIG_RTC_HIRES
-      if (g_rtc_enabled)
+      if (g_rtc_enabled && clockid != CLOCK_ACTIVETIME)
         {
           /* Yes.. Get the hi-resolution time from the RTC */
 
diff --git a/nuttx/sched/clock_settime.c b/nuttx/sched/clock_settime.c
index 9db3112df..fdb6a6c57 100644
--- a/nuttx/sched/clock_settime.c
+++ b/nuttx/sched/clock_settime.c
@@ -100,7 +100,11 @@ int clock_settime(clockid_t clock_id, FAR const struct timespec *tp)
    * time clock.
    */
 
-  if (clock_id == CLOCK_REALTIME) 
+#ifdef CONFIG_RTC
+  if (clock_id == CLOCK_REALTIME || clockid == CLOCK_ACTIVETIME)
+#else
+  if (clock_id == CLOCK_REALTIME)
+#endif
     {
       /* Interrupts are disabled here so that the in-memory time
        * representation and the RTC setting will be as close as
@@ -123,7 +127,7 @@ int clock_settime(clockid_t clock_id, FAR const struct timespec *tp)
       /* Setup the RTC (lo- or high-res) */
 
 #ifdef CONFIG_RTC
-      if (g_rtc_enabled)
+      if (g_rtc_enabled && clockid != CLOCK_ACTIVETIME)
         {
           up_rtc_settime(tp);
         }