ports/nrf: Updates for review comments.

RetiredWizard · RetiredWizard · commit db55ee0ca216 · 2023-01-03T14:50:15.000-05:00
Added missing check for rtc_offset prefix/suffix.
Changed millisecond divisor from 999 to 1000.
Added 64 bit ticks counter to increase time before rollover.
Made time.sleep and time.ticks_cpu methods to the time library
on all builds (unconditionally).
Removed unnecessary working comments.

Signed-off-by: RetiredWizard &lt;github@retiredwizard.com&gt;
diff --git a/ports/nrf/modules/machine/rtc.c b/ports/nrf/modules/machine/rtc.c
@@ -3,10 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
- * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
  * Copyright (c) 2019 Nick Moore for Adafruit Industries
- * Copyright (c) 2021 Junji Sakai
  * Copyright (c) 2021 "Krzysztof Adamski" <k@japko.eu>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -36,24 +33,36 @@
 #include "py/mphal.h"
 #include "shared/timeutils/timeutils.h"
 
-// Circuitpython RTC.C
-
-#define RTC_OFFSET_CHECK_PREFIX 0x25ea7e2a
-#define RTC_OFFSET_CHECK_SUFFIX 0x2b80b69e
+extern uint64_t ticks_ms_64(void);
 
 // This is the time in seconds since 2000 that the RTC was started.
 __attribute__((section(".uninitialized"))) static uint32_t rtc_offset[3];
 
+// These values are placed before and after the current RTC count.  They are
+// used to determine if the RTC count is valid.  These randomly-generated values
+// will be set when the RTC value is set in order to mark the RTC as valid. If
+// the system crashes or reboots, these values will remain undisturbed and the
+// RTC offset will remain valid.
+//
+// If MicroPython is updated or these symbols shift around, the prefix and
+// suffix will no longer match, and the time will no longer be valid.
+#define RTC_OFFSET_CHECK_PREFIX 0x25ea7e2a
+#define RTC_OFFSET_CHECK_SUFFIX 0x2b80b69e
+
+void rtc_offset_check(void) {
+    // If the prefix and suffix are not valid, zero-initialize the RTC offset.
+    if ((rtc_offset[0] != RTC_OFFSET_CHECK_PREFIX) || (rtc_offset[2] != RTC_OFFSET_CHECK_SUFFIX)) {
+        rtc_offset[1] = 0;
+    }
+}
 
 void rtc_get_time(timeutils_struct_time_t *tm) {
-    // uint64_t ticks_s = port_get_raw_ticks(NULL) / 1024;
-    uint64_t ticks_s = mp_hal_ticks_ms() / 999;
+    uint64_t ticks_s = ticks_ms_64() / 1000;
     timeutils_seconds_since_2000_to_struct_time(rtc_offset[1] + ticks_s, tm);
 }
 
 void rtc_set_time(timeutils_struct_time_t *tm) {
-    // uint64_t ticks_s = port_get_raw_ticks(NULL) / 1024;
-    uint64_t ticks_s = mp_hal_ticks_ms() / 999;
+    uint64_t ticks_s = ticks_ms_64() / 1000;
     uint32_t epoch_s = timeutils_seconds_since_2000(
         tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec
         );
@@ -66,8 +75,6 @@ void rtc_set_time(timeutils_struct_time_t *tm) {
     rtc_offset[2] = RTC_OFFSET_CHECK_SUFFIX;
 }
 
-// end of Circuitpython
-
 typedef struct _machine_rtc_obj_t {
     mp_obj_base_t base;
 } machine_rtc_obj_t;
@@ -78,29 +85,15 @@ STATIC const machine_rtc_obj_t machine_rtc_obj = {{&machine_rtc_type}};
 STATIC mp_obj_t machine_rtc_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     // check arguments
     mp_arg_check_num(n_args, n_kw, 0, 0, false);
-    // bool r = rtc_running();
-
-    // if (!r) {
-    //      This shouldn't happen as rtc_init() is already called in main so
-    //      it's here just in case
-    //    rtc_init();
-    //    datetime_t t = { .month = 1, .day = 1 };
-    //    rtc_set_datetime(&t);
-    // }
+
     // return constant object
     return (mp_obj_t)&machine_rtc_obj;
 }
 
 STATIC mp_obj_t machine_rtc_datetime(mp_uint_t n_args, const mp_obj_t *args) {
     if (n_args == 1) {
-        // bool ret;
-        // datetime_t t;
         timeutils_struct_time_t t;
 
-        // ret = rtc_get_datetime(&t);
-        // if (!ret) {
-        //    mp_raise_OSError(MP_EIO);
-        // }
         rtc_get_time(&t);
 
         mp_obj_t tuple[8] = {
@@ -131,9 +124,6 @@ STATIC mp_obj_t machine_rtc_datetime(mp_uint_t n_args, const mp_obj_t *args) {
         // Deliberately ignore the weekday argument and compute the proper value
         t.tm_wday = timeutils_calc_weekday(t.tm_year, t.tm_mon, t.tm_mday);
 
-        // if (!rtc_set_time(&t)) {
-        //    mp_raise_OSError(MP_EINVAL);
-        // }
         rtc_set_time(&t);
 
     }
diff --git a/ports/nrf/modules/utime/modutime.c b/ports/nrf/modules/utime/modutime.c
@@ -48,7 +48,6 @@ void rtc_get_time(timeutils_struct_time_t *time);
 STATIC mp_obj_t time_localtime(size_t n_args, const mp_obj_t *args) {
     if (n_args == 0 || args[0] == mp_const_none) {
         // Get current date and time.
-        // datetime_t t;
         timeutils_struct_time_t t;
         rtc_get_time(&t);
         mp_obj_t tuple[8] = {
@@ -125,17 +124,14 @@ STATIC const mp_rom_map_elem_t time_module_globals_table[] = {
 
     { MP_ROM_QSTR(MP_QSTR_time), MP_ROM_PTR(&time_time_obj) },
     { MP_ROM_QSTR(MP_QSTR_time_ns), MP_ROM_PTR(&mp_utime_time_ns_obj) },
-
-    { MP_ROM_QSTR(MP_QSTR_sleep), MP_ROM_PTR(&mp_utime_sleep_obj) },
 #endif
+    { MP_ROM_QSTR(MP_QSTR_sleep), MP_ROM_PTR(&mp_utime_sleep_obj) },
     { MP_ROM_QSTR(MP_QSTR_sleep_ms), MP_ROM_PTR(&mp_utime_sleep_ms_obj) },
     { MP_ROM_QSTR(MP_QSTR_sleep_us), MP_ROM_PTR(&mp_utime_sleep_us_obj) },
 
     { MP_ROM_QSTR(MP_QSTR_ticks_ms), MP_ROM_PTR(&mp_utime_ticks_ms_obj) },
     { MP_ROM_QSTR(MP_QSTR_ticks_us), MP_ROM_PTR(&mp_utime_ticks_us_obj) },
-#if MICROPY_PY_MACHINE_RTC    
     { MP_ROM_QSTR(MP_QSTR_ticks_cpu), MP_ROM_PTR(&mp_utime_ticks_cpu_obj) },
-#endif
     { MP_ROM_QSTR(MP_QSTR_ticks_add), MP_ROM_PTR(&mp_utime_ticks_add_obj) },
     { MP_ROM_QSTR(MP_QSTR_ticks_diff), MP_ROM_PTR(&mp_utime_ticks_diff_obj) },
 };
diff --git a/ports/nrf/mphalport.c b/ports/nrf/mphalport.c
@@ -101,6 +101,7 @@ void rtc1_init_time_ticks(void) {
     // Start the low-frequency clock (if it hasn't been started already)
     if (!nrf_clock_lf_is_running(NRF_CLOCK)) {
         nrf_clock_task_trigger(NRF_CLOCK, NRF_CLOCK_TASK_LFCLKSTART);
+        rtc_offset_check();
     }
     // Uninitialize first, then set overflow IRQ and first CC event
     nrfx_rtc_uninit(&rtc1);
@@ -110,7 +111,8 @@ void rtc1_init_time_ticks(void) {
     nrfx_rtc_enable(&rtc1);
 }
 
-mp_uint_t mp_hal_ticks_ms(void) {
+
+uint64_t ticks_ms_64(void) {
     // Compute: (rtc_overflows << 24 + COUNTER) * 1000 / 32768
     //
     // Note that COUNTER * 1000 / 32768 would overflow during calculation, so use
@@ -123,7 +125,11 @@ mp_uint_t mp_hal_ticks_ms(void) {
     uint32_t counter;
     // guard against overflow irq
     RTC1_GET_TICKS_ATOMIC(rtc1, overflows, counter)
-    return (overflows << 9) * 1000 + (counter * 125 / 4096);
+    return ((uint64_t)overflows << 9) * 1000 + (counter * 125 / 4096);
+}
+
+mp_uint_t mp_hal_ticks_ms(void) {
+    return ticks_ms_64();
 }
 
 mp_uint_t mp_hal_ticks_us(void) {
diff --git a/ports/nrf/mphalport.h b/ports/nrf/mphalport.h
@@ -72,6 +72,7 @@ void rtc1_init_time_ticks();
 mp_uint_t mp_hal_ticks_ms(void);
 #define mp_hal_ticks_us() (0)
 #endif
+extern void rtc_offset_check(void);
 
 // TODO: empty implementation for now. Used by machine_spi.c:69
 #define mp_hal_delay_us_fast(p)
