circuitpython/ports/raspberrypi/common-hal/countio/Counter.c

116 lines
3.3 KiB
C

#include "shared-bindings/countio/Counter.h"
#include "py/runtime.h"
#include "py/mpstate.h"
#include "shared-bindings/countio/Edge.h"
#include "shared-bindings/digitalio/Pull.h"
#include "common-hal/pwmio/PWMOut.h"
#include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
#include "src/rp2_common/hardware_pwm/include/hardware/pwm.h"
#include "src/rp2_common/hardware_irq/include/hardware/irq.h"
void common_hal_countio_counter_construct(countio_counter_obj_t *self,
const mcu_pin_obj_t *pin, countio_edge_t edge, digitalio_pull_t pull) {
if (pwm_gpio_to_channel(pin->number) != PWM_CHAN_B) {
mp_raise_RuntimeError(MP_ERROR_TEXT("Pin must be on PWM Channel B"));
}
if (edge == EDGE_RISE_AND_FALL) {
mp_raise_NotImplementedError(MP_ERROR_TEXT("RISE_AND_FALL not available on this chip"));
}
self->pin = pin->number;
self->slice_num = pwm_gpio_to_slice_num(self->pin);
if (MP_STATE_PORT(counting)[self->slice_num] != NULL) {
mp_raise_RuntimeError(MP_ERROR_TEXT("PWM slice already in use"));
}
if (!pwmio_claim_slice_ab_channels(self->slice_num)) {
mp_raise_RuntimeError(MP_ERROR_TEXT("PWM slice channel A already in use"));
}
pwm_clear_irq(self->slice_num);
pwm_set_irq_enabled(self->slice_num, true);
irq_set_exclusive_handler(PWM_IRQ_WRAP, counter_interrupt_handler);
irq_set_enabled(PWM_IRQ_WRAP, true);
pwm_config cfg = pwm_get_default_config();
pwm_config_set_clkdiv_mode(&cfg, edge == EDGE_RISE ? PWM_DIV_B_RISING : PWM_DIV_B_FALLING);
pwm_init(self->slice_num, &cfg, false);
gpio_set_function(self->pin, GPIO_FUNC_PWM);
gpio_set_pulls(self->pin, pull == PULL_UP, pull == PULL_DOWN);
claim_pin(pin);
MP_STATE_PORT(counting)[self->slice_num] = self;
self->count = 0;
pwm_set_enabled(self->slice_num, true);
}
void reset_countio(void) {
for (size_t i = 0; i < NUM_PWM_SLICES; i++) {
if (MP_STATE_PORT(counting)[i] != NULL) {
common_hal_countio_counter_deinit(MP_STATE_PORT(counting)[i]);
}
}
}
bool common_hal_countio_counter_deinited(countio_counter_obj_t *self) {
return self->pin == 0;
}
void common_hal_countio_counter_deinit(countio_counter_obj_t *self) {
if (common_hal_countio_counter_deinited(self)) {
return;
}
pwm_set_enabled(self->slice_num, false);
pwm_set_irq_enabled(self->slice_num, false);
pwmio_release_slice_ab_channels(self->slice_num);
reset_pin_number(self->pin);
MP_STATE_PORT(counting)[self->slice_num] = NULL;
self->pin = 0;
self->slice_num = 0;
}
mp_int_t common_hal_countio_counter_get_count(countio_counter_obj_t *self) {
self->count += pwm_get_counter(self->slice_num);
pwm_set_counter(self->slice_num, 0);
return self->count;
}
void common_hal_countio_counter_set_count(countio_counter_obj_t *self,
mp_int_t new_count) {
pwm_set_counter(self->slice_num, 0);
self->count = new_count;
}
void counter_interrupt_handler(void) {
uint32_t mask = pwm_get_irq_status_mask();
uint8_t i = 1;
uint8_t pos = 0;
while (!(i & mask)) {
i = i << 1;
++pos;
}
countio_counter_obj_t *self = MP_STATE_PORT(counting)[pos];
if (self != NULL) {
pwm_clear_irq(self->slice_num);
self->count += 65536;
}
}
MP_REGISTER_ROOT_POINTER(mp_obj_t counting[enum_NUM_PWM_SLICES]);