circuitpython/ports/raspberrypi/common-hal/pulseio/PulseIn.c

243 lines
9.0 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Dave Putz for Adafruit Industries
*
* 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 "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
#include <stdint.h>
#include "py/runtime.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "shared-bindings/pulseio/PulseIn.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "supervisor/shared/translate.h"
#include "bindings/rp2pio/StateMachine.h"
#include "common-hal/pulseio/PulseIn.h"
#define NO_PIN 0xff
#define MAX_PULSE 65535
#define MIN_PULSE 10
uint16_t pulsein_program[] = {
0x4001, // 1: in pins, 1
};
void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t *self,
const mcu_pin_obj_t *pin, uint16_t maxlen, bool idle_state) {
self->buffer = (uint16_t *)m_malloc(maxlen * sizeof(uint16_t), false);
if (self->buffer == NULL) {
mp_raise_msg_varg(&mp_type_MemoryError, translate("Failed to allocate RX buffer of %d bytes"), maxlen * sizeof(uint16_t));
}
self->pin = pin->number;
self->maxlen = maxlen;
self->idle_state = idle_state;
self->start = 0;
self->len = 0;
bool ok = rp2pio_statemachine_construct(&self->state_machine,
pulsein_program, sizeof(pulsein_program) / sizeof(pulsein_program[0]),
1000000,
NULL, 0,
NULL, 0,
pin, 1,
0,0,
NULL, 0,
NULL, 0,
1, 0,
NULL, // jump pin
1 << self->pin, false, true,
false, 8, false, // TX, unused
false,
true, 32, true, // RX auto-push every 32 bits
false, // claim pins
false, // Not user-interruptible.
false, // No sideset enable
0, -1); // wrap settings
if (!ok) {
mp_raise_RuntimeError(translate("All state machines in use"));
}
pio_sm_set_enabled(self->state_machine.pio,self->state_machine.state_machine, false);
pio_sm_clear_fifos(self->state_machine.pio,self->state_machine.state_machine);
self->last_level = self->idle_state;
self->level_count = 0;
self->buf_index = 0;
pio_sm_set_in_pins(self->state_machine.pio,self->state_machine.state_machine,pin->number);
common_hal_rp2pio_statemachine_set_interrupt_handler(&(self->state_machine),&common_hal_pulseio_pulsein_interrupt,self,PIO_IRQ0_INTE_SM0_RXNEMPTY_BITS);
// exec a set pindirs to 0 for input
pio_sm_exec(self->state_machine.pio,self->state_machine.state_machine,0xe080);
// exec the appropriate wait for pin
if (self->idle_state == true) {
pio_sm_exec(self->state_machine.pio,self->state_machine.state_machine,0x2020);
} else {
pio_sm_exec(self->state_machine.pio,self->state_machine.state_machine,0x20a0);
}
pio_sm_set_enabled(self->state_machine.pio, self->state_machine.state_machine, true);
}
bool common_hal_pulseio_pulsein_deinited(pulseio_pulsein_obj_t *self) {
return self->pin == NO_PIN;
}
void common_hal_pulseio_pulsein_deinit(pulseio_pulsein_obj_t *self) {
if (common_hal_pulseio_pulsein_deinited(self)) {
return;
}
pio_sm_set_enabled(self->state_machine.pio, self->state_machine.state_machine, false);
common_hal_rp2pio_statemachine_deinit(&self->state_machine);
m_free(self->buffer);
reset_pin_number(self->pin);
self->pin = NO_PIN;
}
void common_hal_pulseio_pulsein_pause(pulseio_pulsein_obj_t *self) {
pio_sm_restart(self->state_machine.pio, self->state_machine.state_machine);
pio_sm_set_enabled(self->state_machine.pio, self->state_machine.state_machine, false);
self->last_level = self->idle_state;
self->level_count = 0;
self->buf_index = 0;
}
void common_hal_pulseio_pulsein_interrupt(void *self_in) {
pulseio_pulsein_obj_t *self = self_in;
uint32_t rxfifo = 0;
rxfifo = pio_sm_get_blocking(self->state_machine.pio, self->state_machine.state_machine);
// translate from fifo to buffer
if ((rxfifo == 0 && self->last_level == false) || (rxfifo == 0xffffffff && self->last_level == true)) {
self->level_count = self->level_count + 32;
} else {
for (uint i = 0; i < 32; i++) {
bool level = (rxfifo & (1 << i)) >> i;
if (level == self->last_level) {
self->level_count++;
} else {
uint32_t result = self->level_count;
self->last_level = level;
self->level_count = 0;
// Pulses that are longer than MAX_PULSE will return MAX_PULSE
if (result > MAX_PULSE) {
result = MAX_PULSE;
}
// return pulses that are not too short
if (result > MIN_PULSE) {
self->buffer[self->buf_index] = (uint16_t)result;
if (self->len < self->maxlen) {
self->len++;
}
if (self->buf_index < self->maxlen) {
self->buf_index++;
} else {
self->start = 0;
self->buf_index = 0;
}
}
}
}
}
// check for a pulse thats too long (MAX_PULSE us) or maxlen reached, and reset
if ((self->level_count > MAX_PULSE) || (self->buf_index >= self->maxlen)) {
pio_sm_set_enabled(self->state_machine.pio, self->state_machine.state_machine, false);
pio_sm_init(self->state_machine.pio, self->state_machine.state_machine, self->state_machine.offset, &self->state_machine.sm_config);
pio_sm_restart(self->state_machine.pio,self->state_machine.state_machine);
pio_sm_set_enabled(self->state_machine.pio, self->state_machine.state_machine, true);
self->buf_index = 0;
self->start = 0;
}
}
void common_hal_pulseio_pulsein_resume(pulseio_pulsein_obj_t *self,
uint16_t trigger_duration) {
// Send the trigger pulse.
if (trigger_duration > 0) {
gpio_set_function(self->pin,GPIO_FUNC_SIO);
gpio_set_dir(self->pin,true);
gpio_put(self->pin, !self->idle_state);
common_hal_mcu_delay_us((uint32_t)trigger_duration);
gpio_set_function(self->pin,GPIO_FUNC_PIO0);
common_hal_mcu_delay_us(125);
}
// Reconfigure the pin for PIO
gpio_set_function(self->pin, GPIO_FUNC_PIO0);
// exec a wait for the selected pin to change state
if (self->idle_state == true) {
pio_sm_exec(self->state_machine.pio,self->state_machine.state_machine,0x2020);
} else {
pio_sm_exec(self->state_machine.pio,self->state_machine.state_machine,0x20a0);
}
pio_sm_set_enabled(self->state_machine.pio, self->state_machine.state_machine, true);
}
void common_hal_pulseio_pulsein_clear(pulseio_pulsein_obj_t *self) {
self->start = 0;
self->len = 0;
self->buf_index = 0;
}
uint16_t common_hal_pulseio_pulsein_popleft(pulseio_pulsein_obj_t *self) {
if (self->len == 0) {
mp_raise_IndexError_varg(translate("pop from empty %q"), MP_QSTR_PulseIn);
}
uint16_t value = self->buffer[self->start];
self->start = (self->start + 1) % self->maxlen;
self->len--;
// if we are empty reset buffer pointer and counters
if (self->len == 0) {
self->start = 0;
self->buf_index = 0;
self->level_count = 0;
}
return value;
}
uint16_t common_hal_pulseio_pulsein_get_maxlen(pulseio_pulsein_obj_t *self) {
return self->maxlen;
}
uint16_t common_hal_pulseio_pulsein_get_len(pulseio_pulsein_obj_t *self) {
return self->len;
}
bool common_hal_pulseio_pulsein_get_paused(pulseio_pulsein_obj_t *self) {
return true;
}
uint16_t common_hal_pulseio_pulsein_get_item(pulseio_pulsein_obj_t *self,
int16_t index) {
if (index < 0) {
index += self->len;
}
if (index < 0 || index >= self->len) {
mp_raise_IndexError_varg(translate("%q index out of range"), MP_QSTR_PulseIn);
}
uint16_t value = self->buffer[(self->start + index) % self->maxlen];
return value;
}