sys: realtime: Add native real-time library and API

drivers/rtc/CMakeLists.txt

@@ -21,3 +21,4 @@ zephyr_library_sources_ifdef(CONFIG_RTC_SMARTBOND rtc_smartbond.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_ATMEL_SAM rtc_sam.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_RPI_PICO rtc_rpi_pico.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_NUMAKER rtc_numaker.c)
+zephyr_library_sources_ifdef(CONFIG_RTC_HWCLOCK rtc_hwclock.c)

drivers/rtc/Kconfig

@@ -53,5 +53,6 @@ source "drivers/rtc/Kconfig.sam"
 source "drivers/rtc/Kconfig.smartbond"
 source "drivers/rtc/Kconfig.stm32"
 source "drivers/rtc/Kconfig.numaker"
+source "drivers/rtc/Kconfig.hwclock"
 
 endif # RTC

drivers/rtc/Kconfig.hwclock

@@ -0,0 +1,25 @@
+# Copyright (c) 2024 Bjarki Arge Andreasen
+# SPDX-License-Identifier: Apache-2.0
+
+DT_CHOSEN_RTC := zephyr,rtc
+
+config RTC_HWCLOCK
+	bool "Hardware clock"
+	default y
+	depends on $(dt_chosen_enabled,$(DT_CHOSEN_RTC))
+	depends on SYS_REALTIME
+	help
+	  The hardware clock is used to set the system
+	  real-time clock on boot.
+
+if RTC_HWCLOCK
+
+config RTC_HWCLOCK_INIT_PRIORITY
+	int "Initialization priority of hardware clock"
+	default 51
+	help
+	  The initialization priority of the hardware clock
+	  must be higher than the initialization priority of
+	  the chosen RTC device driver.
+
+endif # RTC_HWCLOCK

drivers/rtc/rtc_hwclock.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2024 Bjarki Arge Andreasen
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/init.h>
+#include <zephyr/drivers/rtc.h>
+#include <zephyr/sys/realtime.h>
+
+BUILD_ASSERT(
+	CONFIG_RTC_HWCLOCK_INIT_PRIORITY > CONFIG_RTC_INIT_PRIORITY,
+	"Hardware clock init prio must be higher than the RTC device driver"
+);
+
+static const struct device *rtc = DEVICE_DT_GET(DT_CHOSEN(zephyr_rtc));
+
+static const struct sys_datetime *rtc_time_to_sys_datetime(const struct rtc_time *timeptr)
+{
+	return (const struct sys_datetime *)timeptr;
+}
+
+static int rtc_hwclock_init(void)
+{
+	int ret;
+	struct rtc_time rtctime;
+	const struct sys_datetime *datetime;
+
+	if (!device_is_ready(rtc)) {
+		return -ENODEV;
+	}
+
+	ret = rtc_get_time(rtc, &rtctime);
+	if (ret == -ENODATA) {
+		return 0;
+	} else if (ret < 0) {
+		return ret;
+	}
+
+	datetime = rtc_time_to_sys_datetime(&rtctime);
+	return sys_realtime_set_datetime(datetime);
+}
+
+SYS_INIT(rtc_hwclock_init, POST_KERNEL, CONFIG_RTC_HWCLOCK_INIT_PRIORITY);

drivers/rtc/rtc_shell.c

@@ -8,6 +8,7 @@
 #include <zephyr/kernel.h>
 #include <zephyr/shell/shell.h>
 #include <zephyr/drivers/rtc.h>
+#include <zephyr/sys/realtime.h>
 #include <time.h>
 #include <stdlib.h>
 
@@ -227,6 +228,43 @@ static void device_name_get(size_t idx, struct shell_static_entry *entry)
 	entry->subcmd = NULL;
 }
 
+#if CONFIG_SYS_REALTIME
+static int cmd_sync(const struct shell *sh, size_t argc, char **argv)
+{
+	const struct device *dev = device_get_binding(argv[1]);
+
+	if (!device_is_ready(dev)) {
+		shell_error(sh, "device %s not %s", argv[1], "ready");
+		return -ENODEV;
+	}
+
+	ARG_UNUSED(argc);
+	ARG_UNUSED(argv);
+
+	struct rtc_time rtctime;
+
+	int res = rtc_get_time(dev, &rtctime);
+
+	if (res == -ENODATA) {
+		shell_error(sh, "device %s not %s", argv[1], "set");
+		return 0;
+	}
+	if (res < 0) {
+		return res;
+	}
+
+	struct sys_datetime *datetime = (struct sys_datetime *)(&rtctime);
+
+	res = sys_realtime_set_datetime(datetime);
+
+	if (res < 0) {
+		shell_error(sh, "failed to set system realtime from %s", argv[1]);
+	}
+
+	return res;
+}
+#endif /* CONFIG_SYS_REALTIME */
+
 #define RTC_GET_HELP                                                                               \
 	("Get current time (UTC)\n"                                                                \
 	 "Usage: rtc get <device>")
@@ -235,12 +273,22 @@ static void device_name_get(size_t idx, struct shell_static_entry *entry)
 	("Set UTC time\n"                                                                          \
 	 "Usage: rtc set <device> <YYYY-MM-DDThh:mm:ss> | <YYYY-MM-DD> | <hh:mm:ss>")
 
+#if CONFIG_SYS_REALTIME
+#define RTC_SYNC_HELP                                                                              \
+	("Set system realtime from RTC time\n"                                                     \
+	 "Usage: rtc sync <device>")
+#endif /* CONFIG_SYS_REALTIME */
+
 SHELL_DYNAMIC_CMD_CREATE(dsub_device_name, device_name_get);
 
-SHELL_STATIC_SUBCMD_SET_CREATE(sub_rtc,
-			       /* Alphabetically sorted */
-			       SHELL_CMD_ARG(set, &dsub_device_name, RTC_SET_HELP, cmd_set, 3, 0),
-			       SHELL_CMD_ARG(get, &dsub_device_name, RTC_GET_HELP, cmd_get, 2, 0),
-			       SHELL_SUBCMD_SET_END);
+SHELL_STATIC_SUBCMD_SET_CREATE(
+	sub_rtc,
+	SHELL_CMD_ARG(set, &dsub_device_name, RTC_SET_HELP, cmd_set, 3, 0),
+	SHELL_CMD_ARG(get, &dsub_device_name, RTC_GET_HELP, cmd_get, 2, 0),
+#if CONFIG_SYS_REALTIME
+	SHELL_CMD_ARG(sync, &dsub_device_name, RTC_SYNC_HELP, cmd_sync, 2, 0),
+#endif /* CONFIG_SYS_REALTIME */
+	SHELL_SUBCMD_SET_END
+);
 
 SHELL_CMD_REGISTER(rtc, &sub_rtc, "RTC commands", NULL);

include/zephyr/sys/internal/realtime.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2024 Bjarki Arge Andreasen
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_SYS_INTERNAL_REALTIME_H_
+#define ZEPHYR_INCLUDE_SYS_INTERNAL_REALTIME_H_
+
+#include <zephyr/kernel.h>
+#include <zephyr/sys/realtime.h>
+
+/** Validate timestamp */
+bool sys_realtime_validate_timestamp(const int64_t *timestamp_ms);
+
+/** Validate datetime */
+bool sys_realtime_validate_datetime(const struct sys_datetime *datetime);
+
+#endif /* ZEPHYR_INCLUDE_SYS_INTERNAL_REALTIME_H_ */

include/zephyr/sys/realtime.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2024 Bjarki Arge Andreasen
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_SYS_REALTIME_H_
+#define ZEPHYR_INCLUDE_SYS_REALTIME_H_
+
+#include <zephyr/kernel.h>
+
+struct sys_datetime {
+	int tm_sec;	/**< Seconds [0, 59] */
+	int tm_min;	/**< Minutes [0, 59] */
+	int tm_hour;	/**< Hours [0, 23] */
+	int tm_mday;	/**< Day of the month [1, 31] */
+	int tm_mon;	/**< Month [0, 11] */
+	int tm_year;	/**< Year - 1900 */
+	int tm_wday;	/**< Day of the week [0, 6] (Sunday = 0) (Unknown = -1) */
+	int tm_yday;	/**< Day of the year [0, 365] (Unknown = -1) */
+	int tm_isdst;	/**< Daylight saving time flag [-1] (Unknown = -1) */
+	int tm_nsec;	/**< Nanoseconds [0, 999999999] (Unknown = 0) */
+};
+
+/** Get universal coordinated time unix timestamp in milliseconds */
+__syscall int sys_realtime_get_timestamp(int64_t *timestamp_ms);
+/** Set universal coordinated time unix timestamp in milliseconds */
+__syscall int sys_realtime_set_timestamp(const int64_t *timestamp_ms);
+
+/** Get universal coordinated time datetime */
+__syscall int sys_realtime_get_datetime(struct sys_datetime *datetime);
+/** Set universal coordinated time datetime */
+__syscall int sys_realtime_set_datetime(const struct sys_datetime *datetime);
+
+/** Convert universal coordinated time datetime to unix timestamp in milliseconds */
+int sys_realtime_datetime_to_timestamp(int64_t *timestamp_ms, const struct sys_datetime *datetime);
+/** Convert universal coordinated time unix timestamp in milliseconds to datetime */
+int sys_realtime_timestamp_to_datetime(struct sys_datetime *datetime, const int64_t *timestamp_ms);
+
+#include <zephyr/syscalls/realtime.h>
+
+#endif /* ZEPHYR_INCLUDE_SYS_REALTIME_H_ */

lib/CMakeLists.txt

@@ -16,6 +16,7 @@ add_subdirectory(heap)
 add_subdirectory(mem_blocks)
 add_subdirectory(os)
 add_subdirectory(utils)
+add_subdirectory(realtime)
 add_subdirectory_ifdef(CONFIG_SMF smf)
 add_subdirectory_ifdef(CONFIG_OPENAMP              open-amp)
 add_subdirectory_ifdef(CONFIG_ACPI acpi)

lib/Kconfig

@@ -28,4 +28,7 @@ source "lib/acpi/Kconfig"
 source "lib/runtime/Kconfig"
 
 source "lib/utils/Kconfig"
+
+source "lib/realtime/Kconfig"
+
 endmenu

lib/posix/options/CMakeLists.txt

@@ -2,10 +2,6 @@
 
 set(GEN_DIR ${ZEPHYR_BINARY_DIR}/include/generated)
 
-zephyr_syscall_header(
-  posix_clock.h
-)
-
 if(CONFIG_POSIX_API)
   zephyr_include_directories(${ZEPHYR_BASE}/include/zephyr/posix)
 endif()

lib/posix/options/Kconfig.timer

@@ -5,6 +5,7 @@
 
 menuconfig POSIX_TIMERS
 	bool "POSIX timers, clocks, and sleep functions"
+	select SYS_REALTIME
 	help
 	  Select 'y' here and Zephyr will provide implementations of clock_getres(), clock_gettime(),
 	  clock_settime(), nanosleep(), timer_create(), timer_delete(), timer_getoverrun(),