micropython/ports/mimxrt/machine_timer.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2020-2021 Damien P. George
* Copyright (c) 2021 Robert Hammelrath
*
* 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 "py/runtime.h"
#include "py/mperrno.h"
#include "py/mphal.h"
#include "fsl_pit.h"
#include "modmachine.h"
#include CLOCK_CONFIG_H
#define TIMER_MODE_ONE_SHOT (0)
#define TIMER_MODE_PERIODIC (1)
#define TIMER_MIN_PERIOD 1
#define alarm_callback PIT_IRQHandler
#define PIT_IRQ_ID PIT_IRQn
typedef struct _machine_timer_obj_t {
mp_obj_base_t base;
int8_t id;
int8_t channel;
uint32_t mode;
uint32_t tick_hz;
uint32_t delta_us; // for periodic mode
mp_obj_t callback;
} machine_timer_obj_t;
static const int8_t channel_no[MICROPY_HW_PIT_NUM_CHANNELS] = {0, 2, 3}; // no channel 1
static pit_config_t pit_config;
// This is the interrupt handler
// To tell which channel fired one has to poll the flags
void alarm_callback(void) {
for (uint8_t index = 0; index < MICROPY_HW_PIT_NUM_CHANNELS; index++) {
uint32_t flag;
machine_timer_obj_t *self = MP_STATE_PORT(timer_table)[index];
if (self != NULL) {
flag = PIT_GetStatusFlags(PIT, self->channel);
if (flag & kPIT_TimerFlag) { // channel fired
PIT_ClearStatusFlags(PIT, self->channel, kPIT_TimerFlag);
__DSB();
mp_sched_schedule(self->callback, MP_OBJ_FROM_PTR(self));
if (self->mode == TIMER_MODE_ONE_SHOT) {
PIT_StopTimer(PIT, self->channel);
}
}
}
}
}
STATIC void machine_timer_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_timer_obj_t *self = MP_OBJ_TO_PTR(self_in);
qstr mode = self->mode == TIMER_MODE_ONE_SHOT ? MP_QSTR_ONE_SHOT : MP_QSTR_PERIODIC;
mp_printf(print, "Timer(channel=%d, mode=%q, period=%d, tick_hz=%d)",
self->id, mode, self->delta_us / self->tick_hz, self->tick_hz);
}
STATIC mp_obj_t machine_timer_init_helper(machine_timer_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_mode, ARG_callback, ARG_period, ARG_tick_hz, ARG_freq, };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = TIMER_MODE_PERIODIC} },
{ MP_QSTR_callback, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
{ MP_QSTR_period, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0xffffffff} },
{ MP_QSTR_tick_hz, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000} },
{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
};
// Parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
self->mode = args[ARG_mode].u_int;
if (args[ARG_freq].u_obj != mp_const_none) {
// Frequency specified in Hz
#if MICROPY_PY_BUILTINS_FLOAT
self->delta_us = (uint32_t)(MICROPY_FLOAT_CONST(1000000.0) / mp_obj_get_float(args[ARG_freq].u_obj));
#else
self->delta_us = 1000000 / mp_obj_get_int(args[ARG_freq].u_obj);
#endif
} else {
// Period specified
self->tick_hz = args[ARG_tick_hz].u_int;
self->delta_us = (uint64_t)args[ARG_period].u_int * 1000000 / self->tick_hz;
}
if (self->delta_us < TIMER_MIN_PERIOD) {
self->delta_us = TIMER_MIN_PERIOD;
}
self->callback = args[ARG_callback].u_obj;
// Set timer period for channel id
PIT_SetTimerPeriod(PIT, self->channel, USEC_TO_COUNT(self->delta_us, BOARD_BOOTCLOCKRUN_IPG_CLK_ROOT));
// Enable timer interrupts for the channel
PIT_EnableInterrupts(PIT, self->channel, kPIT_TimerInterruptEnable);
// Enable at the NVIC
EnableIRQ(PIT_IRQ_ID);
// Start channel 0
PIT_StartTimer(PIT, self->channel);
return mp_const_none;
}
STATIC mp_obj_t machine_timer_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
machine_timer_obj_t *self;
// Get timer id in the range of 0..2
mp_int_t id = 0;
if (n_args > 0) {
id = mp_obj_get_int(args[0]);
--n_args;
++args;
}
if (id < 0 || id >= MICROPY_HW_PIT_NUM_CHANNELS) {
mp_raise_ValueError(MP_ERROR_TEXT("Timer does not exist"));
}
// check, if a timer exists at that channel and stop it first
if (MP_STATE_PORT(timer_table)[id] != NULL) {
PIT_StopTimer(PIT, channel_no[id]);
self = MP_STATE_PORT(timer_table)[id];
} else {
self = m_new_obj_with_finaliser(machine_timer_obj_t);
self->base.type = &machine_timer_type;
MP_STATE_PORT(timer_table)[id] = self;
}
// Set initial values
self->id = id;
self->channel = channel_no[id];
if (n_args > 0 || n_kw > 0) {
// Start the timer
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
machine_timer_init_helper(self, n_args, args, &kw_args);
}
return MP_OBJ_FROM_PTR(self);
}
STATIC mp_obj_t machine_timer___del__(mp_obj_t self_in) {
machine_timer_obj_t *self = MP_OBJ_TO_PTR(self_in);
PIT_StopTimer(PIT, self->channel);
MP_STATE_PORT(timer_table)[self->id] = NULL;
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_timer___del___obj, machine_timer___del__);
STATIC mp_obj_t machine_timer_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
machine_timer_obj_t *self = MP_OBJ_TO_PTR(args[0]);
PIT_StopTimer(PIT, self->channel);
return machine_timer_init_helper(self, n_args - 1, args + 1, kw_args);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_timer_init_obj, 1, machine_timer_init);
STATIC mp_obj_t machine_timer_deinit(mp_obj_t self_in) {
machine_timer_obj_t *self = MP_OBJ_TO_PTR(self_in);
PIT_StopTimer(PIT, self->channel);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_timer_deinit_obj, machine_timer_deinit);
// Initialize clock an first config
void machine_timer_init_PIT(void) {
// PIT timer
// Enable clock gate for GPIO1
CLOCK_EnableClock(kCLOCK_Gpio1); // ?
// Set PERCLK_CLK divider to 1
CLOCK_SetDiv(kCLOCK_PerclkDiv, 0U);
PIT_GetDefaultConfig(&pit_config);
PIT_Init(PIT, &pit_config);
}
STATIC const mp_rom_map_elem_t machine_timer_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&machine_timer___del___obj) },
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_timer_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&machine_timer_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_ONE_SHOT), MP_ROM_INT(TIMER_MODE_ONE_SHOT) },
{ MP_ROM_QSTR(MP_QSTR_PERIODIC), MP_ROM_INT(TIMER_MODE_PERIODIC) },
};
STATIC MP_DEFINE_CONST_DICT(machine_timer_locals_dict, machine_timer_locals_dict_table);
const mp_obj_type_t machine_timer_type = {
{ &mp_type_type },
.name = MP_QSTR_Timer,
.print = machine_timer_print,
.make_new = machine_timer_make_new,
.locals_dict = (mp_obj_dict_t *)&machine_timer_locals_dict,
};