Use time 0 for low_power_start_aon_timer

Also use low_power_start_aon_timer_at_time_ms in low power tests

Author: will-v-pi

src/rp2_common/pico_low_power/include/pico/low_power.h

@@ -293,6 +293,9 @@ pstate_bitset_t *low_power_persistent_pstate_get(pstate_bitset_t *pstate);
  *  \ingroup pico_low_power
  * See \ref aon_timer_start for more information.
  *
+ * If the AON timer is already running, this function will restart it
+ * from the specified time.
+ *
  * \param ms The time in milliseconds to start the AON timer at.
  * \return true on success, false on failure.
  */
@@ -304,14 +307,16 @@ static inline bool low_power_start_aon_timer_at_time_ms(uint64_t ms) {
 
 /*! \brief  Start the AON timer at the current system time
  *  \ingroup pico_low_power
+ *
  * See \ref aon_timer_start for more information.
  *
+ * If the AON timer is already running, this function will not restart it.
+ *
  * \return true on success, false on failure.
  */
 static inline bool low_power_start_aon_timer(void) {
-    struct timespec ts;
-    ms_to_timespec(to_ms_64_since_boot(get_absolute_time()), &ts);
-    return aon_timer_start(&ts);
+    if (aon_timer_is_running()) return true;
+    return low_power_start_aon_timer_at_time_ms(0);
 }
 
 /*! \brief  Sleep for a number of microseconds
@@ -351,7 +356,7 @@ static inline int low_power_sleep_for_ms(uint32_t ms, const clock_dest_bitset_t
  * \return 0 on success, non-zero on error.
  */
 static inline int low_power_dormant_for_ms(uint32_t ms, dormant_clock_source_t dormant_clock_source, const clock_dest_bitset_t *keep_enabled) {
-    if (!aon_timer_is_running()) low_power_start_aon_timer();
+    low_power_start_aon_timer();
     return low_power_dormant_until_aon_timer(aon_timer_make_timeout_time_ms(ms), dormant_clock_source, keep_enabled);
 }
 
@@ -366,7 +371,7 @@ static inline int low_power_dormant_for_ms(uint32_t ms, dormant_clock_source_t d
  * \return 0 on success, non-zero on error.
  */
 static inline int low_power_pstate_for_ms(uint32_t ms, pstate_bitset_t *pstate, low_power_pstate_resume_func resume_func) {
-    if (!aon_timer_is_running()) low_power_start_aon_timer();
+    low_power_start_aon_timer();
     return low_power_pstate_until_aon_timer(aon_timer_make_timeout_time_ms(ms), pstate, resume_func);
 }
 #endif

test/pico_low_power_test/low_power_test_gpio.c

@@ -81,8 +81,6 @@ int main() {
     printf("Waiting %d seconds\n", SLEEP_TIME_S); // so we can see some repeat printfs
     busy_wait_ms(SLEEP_TIME_MS);
 
-    absolute_time_t start_time;
-    struct timespec ts;
     int ret;
 
     printf("Going to sleep until GPIO wakeup\n");
@@ -112,10 +110,7 @@ int main() {
     printf("Doing %d second pause to prove timer running\n", SLEEP_TIME_S);
     busy_wait_ms(SLEEP_TIME_MS);
 
-    // todo, ah; we should start the aon timer; still have to decide what to do about keeping them in sync
-    start_time = get_absolute_time();
-    us_to_timespec(to_us_since_boot(start_time), &ts);
-    aon_timer_start(&ts);
+    low_power_start_aon_timer_at_time_ms(0);
 
     printf("Going DORMANT until GPIO wakeup\n");
 
@@ -143,4 +138,4 @@ int main() {
     printf("PASSED\n");
 
     return 0;
-}
+}

test/pico_low_power_test/low_power_test_timers.c

@@ -138,7 +138,6 @@ int main() {
     absolute_time_t start_time;
     static absolute_time_t __persistent_data(wakeup_time);
     int64_t diff;
-    struct timespec ts;
     int ret;
 
     low_power_set_external_clock_source(DORMANT_CLOCK_HZ_DEFAULT, RTC_GPIO);
@@ -188,10 +187,7 @@ int main() {
 
 
     // start the AON timer
-    start_time = get_absolute_time();
-    us_to_timespec(to_us_since_boot(start_time), &ts);
-    aon_timer_start(&ts);
-
+    low_power_start_aon_timer_at_time_ms(0);
     printf("AON timer started @%dms\n", to_ms_since_boot(aon_timer_get_absolute_time()));
 
 
@@ -251,6 +247,7 @@ int main() {
     printf("Going DORMANT for %d seconds via AON TIMER\n", SLEEP_TIME_S);
 
     start_time = aon_timer_get_absolute_time();
+    absolute_time_t system_time_before = get_absolute_time();
     wakeup_time = delayed_by_ms(start_time, SLEEP_TIME_MS);
     ret = low_power_dormant_until_aon_timer(wakeup_time, DORMANT_CLOCK_SOURCE_DEFAULT, NULL);
     if (ret != PICO_OK) {
@@ -262,14 +259,14 @@ int main() {
     #endif
         EXIT_TEST;
     }
-    // need to use the AON timer for checking time, since the other timer is unclocked
-    diff = absolute_time_diff_us(wakeup_time, get_absolute_time());
-    if (diff > -1000000
+    // check the system timer was stopped while dormant
+    diff = absolute_time_diff_us(system_time_before, get_absolute_time());
+    if (diff > 50 * 1000 // 50ms
         #ifdef PICO_STDIO_USB_CONNECT_WAIT_TIMEOUT_MS
         + (PICO_STDIO_USB_CONNECT_WAIT_TIMEOUT_MS * 1000)
         #endif
     ) {
-        printf("ERROR: doesn't seem like timer was stopped\n");
+        printf("ERROR: doesn't seem like timer was stopped: diff %lldus\n", diff);
         return - 1;
     }
     diff = absolute_time_diff_us(wakeup_time, aon_timer_get_absolute_time());