stmhal: Add time.time() and time.localtime().

time.time: returns seconds since 1/1/2000, as an integer.

time.localtime: Returns 8-tuple: (year, month, date, hour, minute,
    second, weekday, yearday).

stmhal/modtime.c

@@ -24,7 +24,7 @@
  * THE SOFTWARE.
  */
 
-#include <stm32f4xx_hal.h>
+#include "stm32f4xx_hal.h"
 
 #include "mpconfig.h"
 #include "nlr.h"
@@ -32,6 +32,46 @@
 #include "qstr.h"
 #include "obj.h"
 #include "portmodules.h"
+#include "rtc.h"
+
+STATIC const uint days_since_jan1[]= { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
+
+STATIC bool is_leap_year(uint year) {
+    return (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
+}
+
+// compute the day of the year, between 1 and 366
+// month should be between 1 and 12, date should start at 1
+STATIC uint year_day(uint year, uint month, uint date) {
+    uint yday = days_since_jan1[month - 1] + date;
+    if (month >= 3 && is_leap_year(year)) {
+        yday += 1;
+    }
+    return yday;
+}
+
+// returns time stored in RTC as: (year, month, date, hour, minute, second, weekday)
+// weekday is 0-6 for Mon-Sun
+STATIC mp_obj_t time_localtime(void) {
+    // get date and time
+    // note: need to call get time then get date to correctly access the registers
+    RTC_DateTypeDef date;
+    RTC_TimeTypeDef time;
+    HAL_RTC_GetTime(&RTCHandle, &time, FORMAT_BIN);
+    HAL_RTC_GetDate(&RTCHandle, &date, FORMAT_BIN);
+    mp_obj_t tuple[8] = {
+        mp_obj_new_int(2000 + date.Year),
+        mp_obj_new_int(date.Month),
+        mp_obj_new_int(date.Date),
+        mp_obj_new_int(time.Hours),
+        mp_obj_new_int(time.Minutes),
+        mp_obj_new_int(time.Seconds),
+        mp_obj_new_int(date.WeekDay - 1),
+        mp_obj_new_int(year_day(2000 + date.Year, date.Month, date.Date)),
+    };
+    return mp_obj_new_tuple(8, tuple);
+}
+MP_DEFINE_CONST_FUN_OBJ_0(time_localtime_obj, time_localtime);
 
 STATIC mp_obj_t time_sleep(mp_obj_t seconds_o) {
 #if MICROPY_ENABLE_FLOAT
@@ -45,13 +85,36 @@ STATIC mp_obj_t time_sleep(mp_obj_t seconds_o) {
 #endif
     return mp_const_none;
 }
-
 MP_DEFINE_CONST_FUN_OBJ_1(time_sleep_obj, time_sleep);
 
+// returns the number of seconds, as an integer, since 1/1/2000
+STATIC mp_obj_t time_time(void) {
+    // get date and time
+    // note: need to call get time then get date to correctly access the registers
+    RTC_DateTypeDef date;
+    RTC_TimeTypeDef time;
+    HAL_RTC_GetTime(&RTCHandle, &time, FORMAT_BIN);
+    HAL_RTC_GetDate(&RTCHandle, &date, FORMAT_BIN);
+    return mp_obj_new_int(
+        time.Seconds
+        + time.Minutes * 60
+        + time.Hours * 3600
+        + (year_day(2000 + date.Year, date.Month, date.Date) - 1
+            + ((date.Year + 3) / 4) // add a day each 4 years starting with 2001
+            - ((date.Year + 99) / 100) // subtract a day each 100 years starting with 2001
+            + ((date.Year + 399) / 400) // add a day each 400 years starting with 2001
+            ) * 86400
+        + date.Year * 31536000
+    );
+}
+MP_DEFINE_CONST_FUN_OBJ_0(time_time_obj, time_time);
+
 STATIC const mp_map_elem_t time_module_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_time) },
 
+    { MP_OBJ_NEW_QSTR(MP_QSTR_localtime), (mp_obj_t)&time_localtime_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_sleep), (mp_obj_t)&time_sleep_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&time_time_obj },
 };
 
 STATIC const mp_obj_dict_t time_module_globals = {

stmhal/qstrdefsport.h

@@ -236,6 +236,7 @@ Q(urandom)
 
 // for time module
 Q(time)
+Q(localtime)
 Q(sleep)
 
 // for input