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mimxrt/machine_timer: Use soft-timer implementation for machine.Timer.

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This releases the hardware timers for other tasks, which need a higher
resolution and faster response.  And it is less port-specific code.
This commit is contained in:
robert-hh 2022-10-15 11:40:22 +02:00 committed by Damien George
parent 9d2e179fa5
commit 65fa7fd8bb
7 changed files with 55 additions and 123 deletions
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9
docs/mimxrt/quickref.rst
View File

@ -56,21 +56,18 @@ Use the :mod:`time <time>` module::
Timers
------
The i.MXRT port has three hardware timers. Use the :ref:`machine.Timer <machine.Timer>` class
with a timer ID from 0 to 2 (inclusive)::
The i.MXRT port supports virtual Timers. Example of usage::
from machine import Timer
tim0 = Timer(0)
tim0 = Timer(-1)
tim0.init(period=5000, mode=Timer.ONE_SHOT, callback=lambda t:print(0))
tim1 = Timer(1)
tim1 = Timer(-1)
tim1.init(period=2000, mode=Timer.PERIODIC, callback=lambda t:print(1))
The period is in milliseconds.
Virtual timers are not currently supported on this port.
.. _mimxrt_Pins_and_GPIO:
Pins and GPIO

1
ports/mimxrt/Makefile
View File

@ -193,6 +193,7 @@ SHARED_SRC_C += \
shared/runtime/interrupt_char.c \
shared/runtime/mpirq.c \
shared/runtime/pyexec.c \
shared/runtime/softtimer.c \
shared/runtime/stdout_helpers.c \
shared/runtime/sys_stdio_mphal.c \
shared/timeutils/timeutils.c \

3
ports/mimxrt/board_init.c
View File

@ -89,9 +89,6 @@ void board_init(void) {
// ADC
machine_adc_init();
// PIT
machine_timer_init_PIT();
// SDCard
#if MICROPY_PY_MACHINE_SDCARD
machine_sdcard_init0();

152
ports/mimxrt/machine_timer.c
View File

@ -26,66 +26,24 @@
*/
#include "py/runtime.h"
#include "py/mperrno.h"
#include "py/mphal.h"
#include "fsl_pit.h"
#include "modmachine.h"
#include CLOCK_CONFIG_H
#include "shared/runtime/softtimer.h"
#define TIMER_MODE_ONE_SHOT (0)
#define TIMER_MODE_PERIODIC (1)
#define TIMER_MIN_PERIOD 1
typedef soft_timer_entry_t machine_timer_obj_t;
#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);
}
}
}
}
}
const mp_obj_type_t machine_timer_type;
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);
qstr mode = self->mode == SOFT_TIMER_MODE_ONE_SHOT ? MP_QSTR_ONE_SHOT : MP_QSTR_PERIODIC;
mp_printf(print, "Timer(mode=%q, period=%u)", mode, self->delta_ms);
}
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_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = SOFT_TIMER_MODE_PERIODIC} },
{ MP_QSTR_callback, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ 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} },
@ -96,67 +54,56 @@ STATIC mp_obj_t machine_timer_init_helper(machine_timer_obj_t *self, size_t n_ar
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;
uint64_t delta_ms = self->delta_ms;
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));
delta_ms = (uint32_t)(MICROPY_FLOAT_CONST(1000.0) / mp_obj_get_float(args[ARG_freq].u_obj));
#else
self->delta_us = 1000000 / mp_obj_get_int(args[ARG_freq].u_obj);
delta_ms = 1000 / mp_obj_get_int(args[ARG_freq].u_obj);
#endif
} else {
} else if (args[ARG_period].u_int != 0xffffffff) {
// 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;
delta_ms = (uint64_t)args[ARG_period].u_int * 1000 / args[ARG_tick_hz].u_int;
}
self->callback = args[ARG_callback].u_obj;
if (delta_ms < 1) {
delta_ms = 1;
} else if (delta_ms >= 0x40000000) {
mp_raise_ValueError(MP_ERROR_TEXT("period too large"));
}
self->delta_ms = (uint32_t)delta_ms;
// Set timer period for channel id
PIT_SetTimerPeriod(PIT, self->channel, USEC_TO_COUNT(self->delta_us, BOARD_BOOTCLOCKRUN_IPG_CLK_ROOT));
if (args[ARG_callback].u_obj != MP_OBJ_NULL) {
self->py_callback = args[ARG_callback].u_obj;
}
// 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);
if (self->py_callback != mp_const_none) {
soft_timer_insert(self, self->delta_ms);
}
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;
machine_timer_obj_t *self = m_new_obj(machine_timer_obj_t);
self->pairheap.base.type = &machine_timer_type;
self->flags = SOFT_TIMER_FLAG_PY_CALLBACK | SOFT_TIMER_FLAG_GC_ALLOCATED;
self->delta_ms = 1000;
self->py_callback = mp_const_none;
// Get timer id in the range of 0..2
mp_int_t id = 0;
// Get timer id (only soft timer (-1) supported at the moment)
mp_int_t id = -1;
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"));
if (id != -1) {
mp_raise_ValueError(MP_ERROR_TEXT("Timer doesn't 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;
@ -167,47 +114,26 @@ STATIC mp_obj_t machine_timer_make_new(const mp_obj_type_t *type, size_t n_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);
soft_timer_remove(self);
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);
soft_timer_remove(self);
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) },
{ MP_ROM_QSTR(MP_QSTR_ONE_SHOT), MP_ROM_INT(SOFT_TIMER_MODE_ONE_SHOT) },
{ MP_ROM_QSTR(MP_QSTR_PERIODIC), MP_ROM_INT(SOFT_TIMER_MODE_PERIODIC) },
};
STATIC MP_DEFINE_CONST_DICT(machine_timer_locals_dict, machine_timer_locals_dict_table);
@ -219,5 +145,3 @@ MP_DEFINE_CONST_OBJ_TYPE(
print, machine_timer_print,
locals_dict, &machine_timer_locals_dict
);
MP_REGISTER_ROOT_POINTER(struct _machine_timer_obj_t *timer_table[MICROPY_HW_PIT_NUM_CHANNELS]);

2
ports/mimxrt/main.c
View File

@ -33,6 +33,7 @@
#include "shared/readline/readline.h"
#include "shared/runtime/gchelper.h"
#include "shared/runtime/pyexec.h"
#include "shared/runtime/softtimer.h"
#include "ticks.h"
#include "tusb.h"
#include "led.h"
@ -120,6 +121,7 @@ int main(void) {
mod_network_deinit();
#endif
machine_pwm_deinit_all();
soft_timer_deinit();
gc_sweep_all();
mp_deinit();
}

4
ports/mimxrt/mphalport.h
View File

@ -38,6 +38,10 @@
#define MP_HAL_PIN_FMT "%q"
extern ringbuf_t stdin_ringbuf;
// Define an alias fo systick_ms, because the shared softtimer.c uses
// the symbol uwTick for the systick ms counter.
#define uwTick systick_ms
#define mp_hal_pin_obj_t const machine_pin_obj_t *
#define mp_hal_get_pin_obj(o) pin_find(o)
#define mp_hal_pin_name(p) ((p)->name)

7
ports/mimxrt/systick.c
View File

@ -28,6 +28,9 @@
#include "py/mphal.h"
#include "systick.h"
#include "pendsv.h"
#include "shared/runtime/softtimer.h"
volatile uint32_t systick_ms = 0;
systick_dispatch_t systick_dispatch_table[SYSTICK_DISPATCH_NUM_SLOTS];
@ -44,6 +47,10 @@ void SysTick_Handler(void) {
if (f != NULL) {
f(uw_tick);
}
if (soft_timer_next == uw_tick) {
pendsv_schedule_dispatch(PENDSV_DISPATCH_SOFT_TIMER, soft_timer_handler);
}
}
bool systick_has_passed(uint32_t start_tick, uint32_t delay_ms) {