circuitpython/ports/nrf/mphalport.h
Martin Fischer 15574cd665 nrf: Add support for time.ticks_xxx functions using RTC1.
This commit adds time.ticks_ms/us support using RTC1 as the timebase.  It
also adds the time.ticks_add/diff helper functions.  This feature can be
enabled using MICROPY_PY_TIME_TICKS.  If disabled the system uses the
legacy sleep methods and does not have any ticks functions.

In addition support for MICROPY_EVENT_POLL_HOOK was added to the
time.sleep_ms(x) function, making this function more power efficient and
allows support for select.poll/asyncio.  To support this, the RTC's CCR0
was used to schedule a ~1msec event to wakeup the CPU.

Some important notes about the RTC timebase:

- Since the granularity of RTC1's ticks are approx 30usec, time.ticks_us is
not perfect, does not have 1us resolution, but is otherwise quite usable.
For tighter measurments the ticker's 1MHz counter should be used.

- time.ticks_ms(x) should *not* be called in an IRQ with higher prio than
the RTC overflow irq (3).  If so it introduces a race condition and
possibly leads to wrong tick calculations.

See #6171 and #6202.
2020-07-08 23:47:02 +10:00

80 lines
2.7 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2015 Glenn Ruben Bakke
*
* 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.
*/
#ifndef __NRF52_HAL
#define __NRF52_HAL
#include "py/mpconfig.h"
#include <nrfx.h>
#include "pin.h"
#include "nrf_gpio.h"
#include "nrfx_config.h"
typedef enum
{
HAL_OK = 0x00,
HAL_ERROR = 0x01,
HAL_BUSY = 0x02,
HAL_TIMEOUT = 0x03
} HAL_StatusTypeDef;
extern const unsigned char mp_hal_status_to_errno_table[4];
NORETURN void mp_hal_raise(HAL_StatusTypeDef status);
void mp_hal_set_interrupt_char(int c); // -1 to disable
int mp_hal_stdin_rx_chr(void);
void mp_hal_stdout_tx_str(const char *str);
void mp_hal_delay_ms(mp_uint_t ms);
void mp_hal_delay_us(mp_uint_t us);
const char *nrfx_error_code_lookup(uint32_t err_code);
#define mp_hal_pin_obj_t const pin_obj_t *
#define mp_hal_get_pin_obj(o) pin_find(o)
#define mp_hal_pin_high(p) nrf_gpio_pin_set(p->pin)
#define mp_hal_pin_low(p) nrf_gpio_pin_clear(p->pin)
#define mp_hal_pin_read(p) (nrf_gpio_pin_dir_get(p->pin) == NRF_GPIO_PIN_DIR_OUTPUT) ? nrf_gpio_pin_out_read(p->pin) : nrf_gpio_pin_read(p->pin)
#define mp_hal_pin_write(p, v) ((v) ? mp_hal_pin_high(p) : mp_hal_pin_low(p))
#define mp_hal_pin_od_low(p) mp_hal_pin_low(p)
#define mp_hal_pin_od_high(p) mp_hal_pin_high(p)
#define mp_hal_pin_open_drain(p) nrf_gpio_cfg_input(p->pin, NRF_GPIO_PIN_NOPULL)
#if MICROPY_PY_TIME_TICKS
void rtc1_init_time_ticks();
#else
mp_uint_t mp_hal_ticks_ms(void);
#define mp_hal_ticks_us() (0)
#endif
// TODO: empty implementation for now. Used by machine_spi.c:69
#define mp_hal_delay_us_fast(p)
#define mp_hal_ticks_cpu() (0)
#endif