sched/clock: Remove CLOCK_MONOTONIC option from Kconfig

here is the reason:
1.clock_systime_timespec(core function) always exist regardless the setting
2.CLOCK_MONOTONIC is a foundamental clock type required by many places

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

Documentation/guides/pysimcoder.rst

@@ -49,19 +49,18 @@ with NuttX. The list is the following:
 ``CONFIG_BOARDCTL_APP_SYMTAB=y``     ``CONFIG_NSH_LINELEN=64``
 ``CONFIG_BOARDCTL_OS_SYMTAB=y``      ``CONFIG_NSH_READLINE=y``
 ``CONFIG_BUILTIN=y``                 ``CONFIG_NSH_ROMFSETC=y``
-``CONFIG_CLOCK_MONOTONIC=y``         ``CONFIG_PSEUDOTERM=y``
+``CONFIG_ELF=y``                     ``CONFIG_PSEUDOTERM=y``
-``CONFIG_ELF=y``                     ``CONFIG_PTHREAD_CLEANUP=y``
+``CONFIG_FS_BINFS=y``                ``CONFIG_PTHREAD_CLEANUP=y``
-``CONFIG_FS_BINFS=y``                ``CONFIG_PTHREAD_MUTEX_TYPES=y``
 ``CONFIG_FS_PROCFS=y``               ``CONFIG_PTHREAD_MUTEX_TYPES=y``
-``CONFIG_FS_PROCFS_REGISTER=y``      ``CONFIG_PTHREAD_STACK_MIN=1024``
+``CONFIG_FS_PROCFS_REGISTER=y``      ``CONFIG_PTHREAD_MUTEX_TYPES=y``
-``CONFIG_FS_ROMFS=y``                ``CONFIG_RR_INTERVAL=10``
+``CONFIG_FS_ROMFS=y``                ``CONFIG_PTHREAD_STACK_MIN=1024``
-``CONFIG_FS_TMPFS=y``                ``CONFIG_SCHED_WAITPID=y``
+``CONFIG_FS_TMPFS=y``                ``CONFIG_RR_INTERVAL=10``
-``CONFIG_IDLETHREAD_STACKSIZE=2048`` ``CONFIG_SERIAL_TERMIOS=y``
+``CONFIG_IDLETHREAD_STACKSIZE=2048`` ``CONFIG_SCHED_WAITPID=y``
-``CONFIG_LIBC_EXECFUNCS=y``          ``CONFIG_SYMTAB_ORDEREDBYNAME=y``
+``CONFIG_LIBC_EXECFUNCS=y``          ``CONFIG_SERIAL_TERMIOS=y``
-``CONFIG_LIBC_STRERROR=y``           ``CONFIG_SYSTEM_NSH=y``
+``CONFIG_LIBC_STRERROR=y``           ``CONFIG_SYMTAB_ORDEREDBYNAME=y``
-``CONFIG_MAX_TASKS=16``              ``CONFIG_SYSTEM_NSH_STACKSIZE=4096``
+``CONFIG_MAX_TASKS=16``              ``CONFIG_SYSTEM_NSH=y``
-``CONFIG_NSH_BUILTIN_APPS=y``        ``CONFIG_INIT_ENTRYPOINT="nsh_main"``
+``CONFIG_NSH_BUILTIN_APPS=y``        ``CONFIG_SYSTEM_NSH_STACKSIZE=4096``
-``CONFIG_NSH_FILEIOSIZE=512``
+``CONFIG_NSH_FILEIOSIZE=512``        ``CONFIG_INIT_ENTRYPOINT="nsh_main"``
 ==================================== =====================================
 
 In case you want to use Network and blocks like TCP or UDP, following configuration

arch/arm/src/lc823450/lc823450_dvfs2.c

@@ -127,11 +127,7 @@ static uint64_t _get_current_time64(void)
 {
   struct timespec ts;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
   return (uint64_t)ts.tv_sec * NSEC_PER_SEC + (uint64_t)ts.tv_nsec;
 }
 

arch/arm/src/lc823450/lc823450_rtc.c

@@ -147,10 +147,8 @@ static struct pm_callback_s pm_cb =
 static int cboot = 1;
 #endif /* CONFIG_RTC_DIV */
 
-#ifdef CONFIG_CLOCK_MONOTONIC
 static struct timespec lastupdate_mono;
 static struct timespec lastupdate_rtc;
-#endif
 
 /****************************************************************************
  * Public Data
@@ -550,10 +548,8 @@ int up_rtc_settime(FAR const struct timespec *ts)
   up_rtc_set_default_datetime(tp);
 #endif /* CONFIG_RTC_SAVE_DEFAULT */
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &lastupdate_mono);
   lastupdate_rtc = *ts;
-#endif
 
   /* Start rtc update */
 
@@ -661,8 +657,6 @@ int up_rtc_cancelalarm(void)
 int up_rtc_getrawtime(FAR struct timespec *ts)
 {
   struct tm tm;
-
-#ifdef CONFIG_CLOCK_MONOTONIC
   struct timespec now;
   struct timespec diff;
 
@@ -676,7 +670,6 @@ int up_rtc_getrawtime(FAR struct timespec *ts)
       *ts = lastupdate_rtc;
       return 0;
     }
-#endif
 
   tm.tm_sec  = getreg8(RTC_SEC);
   tm.tm_min  = getreg8(RTC_MIN);

arch/risc-v/src/esp32c3/esp32c3_i2c.c

@@ -851,11 +851,7 @@ static int esp32c3_i2c_polling_waitdone(struct esp32c3_i2c_priv_s *priv)
    * forward and backwards.
    */
 
-  #ifdef CONFIG_CLOCK_MONOTONIC
+  clock_gettime(CLOCK_MONOTONIC, &current_time);
-    clock_gettime(CLOCK_MONOTONIC, &current_time);
-  #else
-    clock_gettime(CLOCK_REALTIME, &current_time);
-  #endif
 
   timeout.tv_sec  = current_time.tv_sec  + 10;
   timeout.tv_nsec = current_time.tv_nsec +  0;
@@ -896,11 +892,7 @@ static int esp32c3_i2c_polling_waitdone(struct esp32c3_i2c_priv_s *priv)
 
       /* Update current time */
 
-      #ifdef CONFIG_CLOCK_MONOTONIC
+      clock_gettime(CLOCK_MONOTONIC, &current_time);
-        clock_gettime(CLOCK_MONOTONIC, &current_time);
-      #else
-        clock_gettime(CLOCK_REALTIME, &current_time);
-      #endif
       current_us = TIMESPEC_TO_US(current_time.tv_sec, current_time.tv_nsec);
     }
 

arch/xtensa/src/esp32/esp32_i2c.c

@@ -784,11 +784,7 @@ static int esp32_i2c_polling_waitdone(struct esp32_i2c_priv_s *priv)
    * forward and backwards.
    */
 
-  #ifdef CONFIG_CLOCK_MONOTONIC
+  clock_gettime(CLOCK_MONOTONIC, &current_time);
-    clock_gettime(CLOCK_MONOTONIC, &current_time);
-  #else
-    clock_gettime(CLOCK_REALTIME, &current_time);
-  #endif
 
   timeout.tv_sec  = current_time.tv_sec  + 10;
   timeout.tv_nsec = current_time.tv_nsec +  0;
@@ -829,11 +825,7 @@ static int esp32_i2c_polling_waitdone(struct esp32_i2c_priv_s *priv)
 
       /* Update current time */
 
-      #ifdef CONFIG_CLOCK_MONOTONIC
+      clock_gettime(CLOCK_MONOTONIC, &current_time);
-        clock_gettime(CLOCK_MONOTONIC, &current_time);
-      #else
-        clock_gettime(CLOCK_REALTIME, &current_time);
-      #endif
       current_us = TIMESPEC_TO_US(current_time.tv_sec, current_time.tv_nsec);
     }
 

drivers/sensors/bmp280.c

@@ -643,11 +643,7 @@ static int bmp280_fetch(FAR struct sensor_lowerhalf_s *lower,
   temp = bmp280_compensate_temp(priv, temp);
   press = bmp280_compensate_press(priv, press);
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
 
   baro_data.timestamp = 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
   baro_data.pressure = press / 100.0f;

drivers/sensors/ds18b20.c

@@ -549,12 +549,8 @@ static int ds18b20_set_alarm(FAR struct ds18b20_dev_s *dev,
 static unsigned long ds18b20_curtime(void)
 {
   struct timespec ts;
-#ifdef CONFIG_CLOCK_MONOTONIC
-  clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
 
+  clock_gettime(CLOCK_MONOTONIC, &ts);
   return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
 }
 

drivers/sensors/hyt271.c

@@ -187,12 +187,8 @@ static void hyt271_temp_from_rawdata(FAR struct hyt271_sensor_data_s *data,
 static unsigned long hyt271_curtime(void)
 {
   struct timespec ts;
-#ifdef CONFIG_CLOCK_MONOTONIC
-  clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
 
+  clock_gettime(CLOCK_MONOTONIC, &ts);
   return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
 }
 

drivers/sensors/lis2dh.c

@@ -1667,11 +1667,7 @@ static int lis2dh_reboot(FAR struct lis2dh_dev_s *dev)
 
   /* Prefer monotonic for timeout calculation when enabled. */
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &start);
-#else
-  clock_gettime(CLOCK_REALTIME, &start);
-#endif
 
   /* Reboot to reset chip. */
 
@@ -1696,11 +1692,7 @@ static int lis2dh_reboot(FAR struct lis2dh_dev_s *dev)
           break;
         }
 
-#ifdef CONFIG_CLOCK_MONOTONIC
       clock_gettime(CLOCK_MONOTONIC, &curr);
-#else
-      clock_gettime(CLOCK_REALTIME, &curr);
-#endif
 
       diff_msec = (curr.tv_sec - start.tv_sec) * 1000;
       diff_msec += (curr.tv_nsec - start.tv_nsec) / (1000 * 1000);

drivers/sensors/ms5611.c

@@ -157,12 +157,8 @@ static const struct sensor_ops_s g_sensor_ops =
 static unsigned long ms5611_curtime(void)
 {
   struct timespec ts;
-#ifdef CONFIG_CLOCK_MONOTONIC
-  clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
 
+  clock_gettime(CLOCK_MONOTONIC, &ts);
   return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
 }
 

drivers/syslog/vsyslog.c

@@ -105,17 +105,12 @@ int nx_vsyslog(int priority, FAR const IPTR char *fmt, FAR va_list *ap)
 
       clock_gettime(CLOCK_REALTIME, &ts);
 
-#elif defined(CONFIG_CLOCK_MONOTONIC)
+#else
       /* Prefer monotonic when enabled, as it can be synchronized to
        * RTC with clock_resynchronize.
        */
 
       clock_gettime(CLOCK_MONOTONIC, &ts);
-
-#else
-      /* Otherwise, fall back to the system timer */
-
-      clock_systime_timespec(&ts);
 #endif
 
       /* Prepend the message with the current time, if available */

fs/vfs/fs_epoll.c

@@ -387,12 +387,7 @@ int epoll_pwait(int epfd, FAR struct epoll_event *evs,
       expire.tv_sec  = timeout / 1000;
       expire.tv_nsec = timeout % 1000 * 1000;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
       clock_gettime(CLOCK_MONOTONIC, &curr);
-#else
-      clock_gettime(CLOCK_REALTIME, &curr);
-#endif
-
       clock_timespec_add(&curr, &expire, &expire);
     }
 
@@ -403,11 +398,7 @@ again:
     }
   else
     {
-#ifdef CONFIG_CLOCK_MONOTONIC
       clock_gettime(CLOCK_MONOTONIC, &curr);
-#else
-      clock_gettime(CLOCK_REALTIME, &curr);
-#endif
       clock_timespec_subtract(&expire, &curr, &diff);
 
       rc = ppoll(eph->poll, eph->occupied + 1, &diff, sigmask);

fs/vfs/fs_timerfd.c

@@ -540,12 +540,9 @@ int timerfd_create(int clockid, int flags)
 
   /* Sanity checks. */
 
-  if (clockid != CLOCK_REALTIME
+  if (clockid != CLOCK_REALTIME &&
-#ifdef CONFIG_CLOCK_MONOTONIC
+      clockid != CLOCK_MONOTONIC &&
-      && clockid != CLOCK_MONOTONIC
+      clockid != CLOCK_BOOTTIME)
-      && clockid != CLOCK_BOOTTIME
-#endif /* CONFIG_CLOCK_MONOTONIC */
-      )
     {
       ret = -EINVAL;
       goto errout;

include/nuttx/clock.h

@@ -182,7 +182,7 @@
 #define TICK2SEC(tick)        (((tick)+(TICK_PER_SEC/2))/TICK_PER_SEC)   /* Rounds */
 
 #if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_SYSTEM_TIME64) && \
-    defined(CONFIG_CLOCK_MONOTONIC) && !defined(CONFIG_SCHED_TICKLESS)
+    !defined(CONFIG_SCHED_TICKLESS)
 /* Initial system timer ticks value close to maximum 32-bit value, to test
  * 64-bit system-timer after going over 32-bit value. This is to make errors
  * of casting 64-bit system-timer to 32-bit variables more visible.

include/nuttx/input/touchscreen.h

@@ -204,11 +204,7 @@ static inline uint64_t touch_get_time(void)
 {
   struct timespec ts;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
   return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
 }
 

include/nuttx/rc/lirc_dev.h

@@ -44,12 +44,7 @@ static inline uint64_t lirc_get_timestamp(void)
 {
   struct timespec ts;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
-
   return 1000000000ull * ts.tv_sec + ts.tv_nsec;
 }
 

include/nuttx/sensors/sensor.h

@@ -283,12 +283,7 @@ static inline uint64_t sensor_get_timestamp(void)
 {
   struct timespec ts;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
-
   return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
 }
 

include/time.h

@@ -71,15 +71,11 @@
  * system time-of-day clock.
  */
 
-#ifdef CONFIG_CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC    1
-#  define CLOCK_MONOTONIC  1
-#endif
 
 /* Monotonic system-wide clock that includes time spent in suspension. */
 
-#ifdef CONFIG_CLOCK_MONOTONIC
+#define CLOCK_BOOTTIME     2
-#  define CLOCK_BOOTTIME   2
-#endif
 
 /* This is a flag that may be passed to the timer_settime() and
  * clock_nanosleep() functions.

libs/libc/netdb/lib_dnscache.c

@@ -35,18 +35,6 @@
 
 #if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
 
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
-/* Use clock monotonic, if possible */
-
-#ifdef CONFIG_CLOCK_MONOTONIC
-#  define DNS_CLOCK CLOCK_MONOTONIC
-#else
-#  define DNS_CLOCK CLOCK_REALTIME
-#endif
-
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -148,9 +136,9 @@ void dns_save_answer(FAR const char *hostname,
   entry = &g_dns_cache[ndx];
 
 #if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
-  /* Get the current time, using CLOCK_MONOTONIC if possible */
+  /* Get the current time */
 
-  clock_gettime(DNS_CLOCK, &now);
+  clock_gettime(CLOCK_MONOTONIC, &now);
   entry->ctime = (time_t)now.tv_sec;
 #endif
 
@@ -228,9 +216,9 @@ int dns_find_answer(FAR const char *hostname, FAR union dns_addr_u *addr,
   dns_semtake();
 
 #if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
-  /* Get the current time, using CLOCK_MONOTONIC if possible */
+  /* Get the current time */
 
-  ret = clock_gettime(DNS_CLOCK, &now);
+  ret = clock_gettime(CLOCK_MONOTONIC, &now);
 #endif
 
   for (ndx = g_dns_tail; ndx != g_dns_head; ndx = next)

libs/libc/netdb/lib_dnsquery.c

@@ -181,7 +181,7 @@ static inline uint16_t dns_alloc_id(void)
 {
   struct timespec ts;
 
-  clock_gettime(CLOCK_REALTIME, &ts);
+  clock_gettime(CLOCK_MONOTONIC, &ts);
   return (uint32_t)ts.tv_nsec + ((uint32_t)ts.tv_nsec >> 16);
 }
 

libs/libc/pthread/pthread_condattr_setclock.c

@@ -51,11 +51,8 @@ int pthread_condattr_setclock(FAR pthread_condattr_t *attr,
                               clockid_t clock_id)
 {
   if (!attr ||
-      (
+      (clock_id != CLOCK_MONOTONIC &&
-#ifdef CONFIG_CLOCK_MONOTONIC
+       clock_id != CLOCK_REALTIME))
-      clock_id != CLOCK_MONOTONIC &&
-#endif
-      clock_id != CLOCK_REALTIME))
     {
       return EINVAL;
     }

libs/libc/time/lib_gethrtime.c

@@ -46,11 +46,6 @@ hrtime_t gethrtime(void)
 {
   struct timespec ts;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   clock_gettime(CLOCK_MONOTONIC, &ts);
-#else
-  clock_gettime(CLOCK_REALTIME, &ts);
-#endif
-
   return (hrtime_t)1000000000 * ts.tv_sec + ts.tv_nsec;
 }

libs/libc/unistd/lib_sysconf.c

@@ -225,11 +225,7 @@ long sysconf(int name)
         return CONFIG_SMP_NCPUS;
 
       case _SC_MONOTONIC_CLOCK:
-#ifdef CONFIG_CLOCK_MONOTONIC
         return 1;
-#else
-        return 0;
-#endif
 
       case _SC_PAGESIZE:
 #ifdef CONFIG_MM_PGSIZE

libs/libxx/Kconfig

@@ -35,7 +35,6 @@ config LIBCXXMINI
 
 config LIBCXX
 	bool "LLVM libc++ C++ Standard Library"
-	select CLOCK_MONOTONIC
 	select LIBC_WCHAR
 	select LIBC_LOCALE
 	---help---

sched/Kconfig

@@ -162,20 +162,6 @@ config SYSTEM_TIME64
 		and/or if a very long "uptime" is required, then this option can be
 		selected to support a 64-bit wide timer.
 
-config CLOCK_MONOTONIC
-	bool "Support CLOCK_MONOTONIC"
-	default n
-	---help---
-		CLOCK_MONOTONIC is an optional standard POSIX clock.  Unlike
-		CLOCK_REALTIME which can move forward and backward when the
-		time-of-day changes, CLOCK_MONOTONIC is the elapsed time since some
-		arbitrary point in the post (the system start-up time for NuttX)
-		and, hence, is always monotonically increasing.  CLOCK_MONOTONIC
-		is, hence, the more appropriate clock for determining time
-		differences.
-
-		The value of the CLOCK_MONOTONIC clock cannot be set via clock_settime().
-
 config ARCH_HAVE_TIMEKEEPING
 	bool
 	default n

sched/clock/clock_getres.c

@@ -57,10 +57,8 @@ int clock_getres(clockid_t clock_id, struct timespec *res)
         ret = ERROR;
         break;
 
-#ifdef CONFIG_CLOCK_MONOTONIC
       case CLOCK_MONOTONIC:
       case CLOCK_BOOTTIME:
-#endif
       case CLOCK_REALTIME:
 
         /* Form the timspec using clock resolution in nanoseconds */

sched/clock/clock_gettime.c

@@ -61,7 +61,6 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
   sinfo("clock_id=%d\n", clock_id);
   DEBUGASSERT(tp != NULL);
 
-#ifdef CONFIG_CLOCK_MONOTONIC
   /* CLOCK_MONOTONIC is an optional under POSIX: "If the Monotonic Clock
    * option is supported, all implementations shall support a clock_id
    * of CLOCK_MONOTONIC defined in <time.h>. This clock represents the
@@ -82,8 +81,6 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
 
       ret = clock_systime_timespec(tp);
     }
-  else
-#endif
 
   /* CLOCK_REALTIME - POSIX demands this to be present.  CLOCK_REALTIME
    * represents the machine's best-guess as to the current wall-clock,
@@ -91,7 +88,7 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
    * backward as the system time-of-day clock is changed.
    */
 
-  if (clock_id == CLOCK_REALTIME)
+  else if (clock_id == CLOCK_REALTIME)
     {
       /* Get the elapsed time since the time-of-day was last set.
        * clock_systime_timespec() provides the time since power was applied;

sched/timer/timer_create.c

@@ -158,12 +158,8 @@ int timer_create(clockid_t clockid, FAR struct sigevent *evp,
 
   /* Sanity checks. */
 
-  if (timerid == NULL || (clockid != CLOCK_REALTIME
+  if (timerid == NULL || (clockid != CLOCK_REALTIME &&
-#ifdef CONFIG_CLOCK_MONOTONIC
+      clockid != CLOCK_MONOTONIC && clockid != CLOCK_BOOTTIME))
-      && clockid != CLOCK_MONOTONIC
-      && clockid != CLOCK_BOOTTIME
-#endif /* CONFIG_CLOCK_MONOTONIC */
-      ))
     {
       set_errno(EINVAL);
       return ERROR;