Merge pull request #16682 from benpicco/rtt_rtc_settimeofday

rtt_rtc: add rtt_rtc_settimeofday() & rtt_rtc_gettimeofday()

drivers/include/rtt_rtc.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2021 ML!PA Consulting GmbH
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @defgroup    drivers_rtt_rtc     RTC emulation on top of a RTT
+ * @ingroup     drivers_periph_rtc
+ *
+ * @{
+ *
+ * @file
+ * @brief       Additional functions provided in addition to the normal RTC API.
+ *
+ * @author      Benjamin Valentin <benjamin.valentin@ml-pa.com>
+ */
+
+#ifndef RTT_RTC_H
+#define RTT_RTC_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Set the time as epoch with sub-second precision
+ *        This feature is an extension provided by the `rtt_rtc` module.
+ *
+ * @note The actual µs precision depends on the underlying hardware.
+ *       The smallest time step will be 1 / @ref RTT_FREQUENCY.
+ *
+ * @param[in] s     The new epoch timestamp
+ * @param[in] us    Sub-Seconds
+ */
+void rtt_rtc_settimeofday(uint32_t s, uint32_t us);
+
+/**
+ * @brief Get the current epoch with sub-second precision
+ *        This feature is an extension provided by the `rtt_rtc` module.
+ *
+ * @note The actual µs precision depends on the underlying hardware.
+ *       The smallest time step will be 1 / @ref RTT_FREQUENCY.
+ *
+ * @param[out] s    The current epoch timestamp
+ * @param[out] us   Sub-Seconds
+ */
+void rtt_rtc_gettimeofday(uint32_t *s, uint32_t *us);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* RTT_RTC_H */
+/** @} */

drivers/rtt_rtc/rtt_rtc.c

@@ -7,7 +7,7 @@
  */
 
 /**
- * @ingroup     drivers_periph_rtc
+ * @ingroup     drivers_rtt_rtc
  * @{
  *
  * @file
@@ -26,9 +26,11 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "irq.h"
 #include "periph/rtc.h"
 #include "periph/rtt.h"
 #include "timex.h"
+#include "rtt_rtc.h"
 
 #define ENABLE_DEBUG    0
 #include "debug.h"
@@ -137,31 +139,31 @@ int rtc_set_time(struct tm *time)
 
 int rtc_get_time_ms(struct tm *time, uint16_t *ms)
 {
-    uint32_t prev = rtc_now;
+    uint32_t now, tmp;
+    unsigned state = irq_disable();
 
-    /* repeat calculation if an alarm triggered in between */
+    now  = rtt_get_counter();
-    do {
+    tmp  = _rtc_now(now);
-        uint32_t now = rtt_get_counter();
-        uint32_t tmp = _rtc_now(now);
 
-        rtc_localtime(tmp, time);
+    *ms = (SUBSECONDS(now - last_alarm) * MS_PER_SEC)
-        *ms = (SUBSECONDS(now) * MS_PER_SEC) / RTT_SECOND;
+        / RTT_SECOND;
-    } while (prev != rtc_now);
+
+    irq_restore(state);
+    rtc_localtime(tmp, time);
 
     return 0;
 }
 
 int rtc_get_time(struct tm *time)
 {
-    uint32_t prev = rtc_now;
+    uint32_t now, tmp;
+    unsigned state = irq_disable();
 
-    /* repeat calculation if an alarm triggered in between */
+    now  = rtt_get_counter();
-    do {
+    tmp  = _rtc_now(now);
-        uint32_t now = rtt_get_counter();
-        uint32_t tmp = _rtc_now(now);
 
-        rtc_localtime(tmp, time);
+    irq_restore(state);
-    } while (prev != rtc_now);
+    rtc_localtime(tmp, time);
 
     return 0;
 }
@@ -184,6 +186,7 @@ int rtc_set_alarm(struct tm *time, rtc_alarm_cb_t cb, void *arg)
     alarm_cb_arg = arg;
     alarm_cb     = cb;
 
+    /* RTT interrupt is disabled here */
     rtc_now      = _rtc_now(now);
     _update_alarm(now);
 
@@ -204,3 +207,27 @@ void rtc_poweroff(void)
 {
     rtt_poweroff();
 }
+
+void rtt_rtc_settimeofday(uint32_t s, uint32_t us)
+{
+    /* disable alarm to prevent race condition */
+    rtt_clear_alarm();
+    uint32_t now = ((uint64_t)us * RTT_SECOND) / US_PER_SEC;
+    rtc_now      = s;
+    rtt_set_counter(now);
+    /* calculate next wake-up period */
+    _update_alarm(0);
+}
+
+void rtt_rtc_gettimeofday(uint32_t *s, uint32_t *us)
+{
+    uint32_t now;
+    unsigned state = irq_disable();
+
+    now  = rtt_get_counter();
+    *s   = _rtc_now(now);
+    *us  = ((uint64_t)SUBSECONDS(now - last_alarm) * US_PER_SEC)
+         / RTT_SECOND;
+
+    irq_restore(state);
+}

tests/unittests/Makefile.ci

@@ -14,6 +14,7 @@ BOARD_INSUFFICIENT_MEMORY := \
     atmega256rfr2-xpro \
     atmega328p \
     atmega328p-xplained-mini \
+    avsextrem \
     b-l072z-lrwan1 \
     blackpill \
     blackpill-128kib \

tests/unittests/tests-rtt_rtc/tests-rtt_rtc.c

@@ -17,6 +17,8 @@
 #include "embUnit.h"
 #include "periph/rtc.h"
 #include "periph/rtt.h"
+#include "timex.h"
+#include "rtt_rtc.h"
 
 void rtt_add_ticks(uint64_t ticks);
 
@@ -203,6 +205,29 @@ static void test_set_alarm_set_time(void)
     TEST_ASSERT_EQUAL_INT(2, alarm.tm_isdst);
 }
 
+static void test_rtt_rtc_settimeofday(void)
+{
+    uint32_t s = 10, sec;
+    uint32_t us = US_PER_SEC / 8, micro_sec;
+
+    rtt_rtc_settimeofday(s, us);
+    rtt_rtc_gettimeofday(&sec, &micro_sec);
+
+    TEST_ASSERT_EQUAL_INT(s, sec);
+    TEST_ASSERT_EQUAL_INT(us, micro_sec);
+
+    rtt_add_ticks(1LU * RTT_FREQUENCY);
+    s++;
+    rtt_rtc_gettimeofday(&sec, &micro_sec);
+    TEST_ASSERT_EQUAL_INT(s, sec);
+
+    rtt_add_ticks(RTT_FREQUENCY / 4);
+    us += US_PER_SEC / 4;
+    rtt_rtc_gettimeofday(&sec, &micro_sec);
+    TEST_ASSERT_EQUAL_INT(s, sec);
+    TEST_ASSERT_EQUAL_INT(us, micro_sec);
+}
+
 Test *tests_rtt_rtt_tests(void)
 {
     EMB_UNIT_TESTFIXTURES(fixtures) {
@@ -210,6 +235,7 @@ Test *tests_rtt_rtt_tests(void)
         new_TestFixture(test_set_alarm),
         new_TestFixture(test_set_alarm_short),
         new_TestFixture(test_set_alarm_set_time),
+        new_TestFixture(test_rtt_rtc_settimeofday),
     };
 
     EMB_UNIT_TESTCALLER(rtt_rtc_tests, NULL, NULL, fixtures);