mirror of
https://github.com/micropython/micropython.git
synced 2026-04-30 04:40:13 +02:00
Damien George
1b2f6e3d1f
Currently the mimxrt port has a resolution of only 1 second for `machine.RTC().datetime()` and `time.time_ns()`. This means (among other things) that it fails the `tests/extmod/time_time_ns.py` test, which requires requires at least 5ms of resolution. The underlying RTC hardware is just a 64-bit counter, and the HAL functions `SNVS_LP_SRTC_GetDatetime()` and `SNVS_LP_SRTC_SetDatetime()` do conversions between y/m/d/h/m/s and this 64-bit value, which counts at a rate of 32kHz. This commit changes the RTC code to access the 64-bit counter directly and therefore improve resolution of all RTC functions to 1/32768 seconds. That makes things much simpler because it a lot of places the code wants to know the number of seconds since the Epoch. Currently it uses a combination of `SNVS_LP_SRTC_GetDatetime()` and `timeutils_seconds_since_epoch()` which converts the 64-bit counter to date-time and then back to seconds. Those operations are computationally expensive. With this commit, getting the number of seconds since the Epoch is as simple as reading the 64-bit counter and dividing by 32768. We can leverage a lot of the timeutils functions to simplify everything, and make it similar to other ports like rp2. Benefits of this change: - simpler, more efficient code to get/set RTC - `machine.RTC().datetime()` now has a non-zero value in the last slot, being the number of microseconds, and has a resolution of 1/32768 seconds - `time.time_ns()` now has a resolution of 1/32768 seconds - the `test/extmod/time_time_ns.py` test now passes Signed-off-by: Damien George <damien@micropython.org>
42 lines
1.7 KiB
C
42 lines
1.7 KiB
C
/*
|
|
* This file is part of the MicroPython project, http://micropython.org/
|
|
*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2019-2023 Damien P. George
|
|
* Copyright (c) 2020 Jim Mussared
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "shared/timeutils/timeutils.h"
|
|
#include "modmachine.h"
|
|
|
|
// Get the localtime.
|
|
static void mp_time_localtime_get(timeutils_struct_time_t *tm) {
|
|
// Get current date and time.
|
|
uint64_t seconds = machine_rtc_get_seconds();
|
|
timeutils_seconds_since_epoch_to_struct_time(seconds, tm);
|
|
}
|
|
|
|
// Return the number of seconds since the Epoch.
|
|
static mp_obj_t mp_time_time_get(void) {
|
|
return timeutils_obj_from_timestamp(machine_rtc_get_seconds());
|
|
}
|