350 lines
11 KiB
C
350 lines
11 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2017-2018 Scott Shawcroft for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "common-hal/pulseio/PulseIn.h"
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#include <stdint.h>
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#include "atmel_start_pins.h"
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#include "hal/include/hal_gpio.h"
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#include "background.h"
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#include "eic_handler.h"
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#include "mpconfigport.h"
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#include "timer_handler.h"
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#include "py/gc.h"
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#include "py/runtime.h"
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#include "samd/external_interrupts.h"
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#include "samd/pins.h"
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#include "samd/timers.h"
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#include "shared-bindings/microcontroller/__init__.h"
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#include "shared-bindings/pulseio/PulseIn.h"
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#include "supervisor/shared/tick.h"
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#include "supervisor/shared/translate.h"
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#include "supervisor/port.h"
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// This timer is shared amongst all PulseIn objects as a higher resolution clock.
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static uint8_t refcount = 0;
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static uint8_t pulsein_tc_index = 0xff;
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volatile static uint32_t overflow_count = 0;
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volatile static uint32_t start_overflow = 0;
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void pulsein_timer_interrupt_handler(uint8_t index) {
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if (index != pulsein_tc_index) return;
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overflow_count++;
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Tc* tc = tc_insts[index];
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if (!tc->COUNT16.INTFLAG.bit.OVF) return;
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// Clear the interrupt bit.
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tc->COUNT16.INTFLAG.reg = TC_INTFLAG_OVF;
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}
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static void pulsein_set_config(pulseio_pulsein_obj_t* self, bool first_edge) {
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uint32_t sense_setting;
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if (!first_edge) {
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sense_setting = EIC_CONFIG_SENSE0_BOTH_Val;
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configure_eic_channel(self->channel, sense_setting);
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return;
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} else if (self->idle_state) {
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sense_setting = EIC_CONFIG_SENSE0_FALL_Val;
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} else {
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sense_setting = EIC_CONFIG_SENSE0_RISE_Val;
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}
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set_eic_handler(self->channel, EIC_HANDLER_PULSEIN);
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turn_on_eic_channel(self->channel, sense_setting);
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}
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void pulsein_interrupt_handler(uint8_t channel) {
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// Turn off interrupts while in handler
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common_hal_mcu_disable_interrupts();
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// Grab the current time first.
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uint32_t current_overflow = overflow_count;
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Tc* tc = tc_insts[pulsein_tc_index];
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#ifdef SAM_D5X_E5X
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tc->COUNT16.CTRLBSET.reg = TC_CTRLBSET_CMD_READSYNC;
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while (tc->COUNT16.SYNCBUSY.bit.COUNT == 1 ||
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tc->COUNT16.CTRLBSET.bit.CMD == TC_CTRLBSET_CMD_READSYNC_Val) {}
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#endif
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uint32_t current_count = tc->COUNT16.COUNT.reg;
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pulseio_pulsein_obj_t* self = get_eic_channel_data(channel);
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if (self->len == 0 ) {
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start_overflow = overflow_count;
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}
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if (self->first_edge) {
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self->first_edge = false;
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pulsein_set_config(self, false);
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} else {
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// Sometimes we beat the overflow interrupt so just fudge overflow in
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// that case.
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if (current_count < self->last_count && current_overflow == self->last_overflow) {
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current_overflow += 1;
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}
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uint32_t total_diff = current_count + 0xffff * (current_overflow - self->last_overflow) - self->last_count;
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// The SAMD21 clock is 48MHz. We prescale it to 3MHz so // 3 here.
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#ifdef SAMD21
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total_diff /= 3;
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#endif
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// Cap duration at 16 bits.
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uint16_t duration = 0xffff;
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if (total_diff < duration) {
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duration = total_diff;
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}
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//check if the input is taking too long, 15 timer overflows is approx 1 second
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if (current_overflow - start_overflow > 15) {
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self->errored_too_fast = true;
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common_hal_pulseio_pulsein_pause(self);
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common_hal_mcu_enable_interrupts();
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return;
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}
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uint16_t i = (self->start + self->len) % self->maxlen;
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self->buffer[i] = duration;
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if (self->len < self->maxlen) {
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self->len++;
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} else {
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self->start++;
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}
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}
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self->last_overflow = current_overflow;
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self->last_count = current_count;
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common_hal_mcu_enable_interrupts();
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}
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void pulsein_reset() {
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#ifdef SAMD21
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rtc_end_pulse();
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#endif
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refcount = 0;
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pulsein_tc_index = 0xff;
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overflow_count = 0;
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}
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void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t* self,
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const mcu_pin_obj_t* pin, uint16_t maxlen, bool idle_state) {
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if (!pin->has_extint) {
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mp_raise_RuntimeError(translate("No hardware support on pin"));
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}
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if (eic_get_enable() && !eic_channel_free(pin->extint_channel)) {
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mp_raise_RuntimeError(translate("EXTINT channel already in use"));
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}
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self->buffer = (uint16_t *) m_malloc(maxlen * sizeof(uint16_t), false);
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if (self->buffer == NULL) {
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mp_raise_msg_varg(&mp_type_MemoryError, translate("Failed to allocate RX buffer of %d bytes"), maxlen * sizeof(uint16_t));
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}
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self->channel = pin->extint_channel;
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self->pin = pin->number;
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self->maxlen = maxlen;
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self->idle_state = idle_state;
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self->start = 0;
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self->len = 0;
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self->first_edge = true;
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self->errored_too_fast = false;
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if (refcount == 0) {
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// Find a spare timer.
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Tc *tc = NULL;
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int8_t index = TC_INST_NUM - 1;
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for (; index >= 0; index--) {
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if (tc_insts[index]->COUNT16.CTRLA.bit.ENABLE == 0) {
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tc = tc_insts[index];
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break;
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}
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}
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if (tc == NULL) {
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mp_raise_RuntimeError(translate("All timers in use"));
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}
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pulsein_tc_index = index;
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set_timer_handler(true, index, TC_HANDLER_PULSEIN);
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#ifdef SAMD21
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// We use GCLK0 for SAMD21 which is 48MHz. We prescale it to 3MHz.
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turn_on_clocks(true, index, 0);
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#endif
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#ifdef SAM_D5X_E5X
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// We use GCLK5 for SAMD51 because it runs at 2MHz and we can use it for a 1MHz clock,
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// 1us per tick.
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turn_on_clocks(true, index, 5);
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#endif
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#ifdef SAMD21
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tc->COUNT16.CTRLA.reg = TC_CTRLA_MODE_COUNT16 |
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TC_CTRLA_PRESCALER_DIV16 |
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TC_CTRLA_WAVEGEN_NFRQ;
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#endif
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#ifdef SAM_D5X_E5X
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tc_reset(tc);
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tc_set_enable(tc, false);
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tc->COUNT16.CTRLA.reg = TC_CTRLA_MODE_COUNT16 | TC_CTRLA_PRESCALER_DIV2;
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tc->COUNT16.WAVE.reg = TC_WAVE_WAVEGEN_NFRQ;
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#endif
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tc_set_enable(tc, true);
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// Clear our interrupt in case it was set earlier
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tc->COUNT16.INTFLAG.reg = TC_INTFLAG_OVF;
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tc->COUNT16.INTENSET.reg = TC_INTENSET_OVF;
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tc_enable_interrupts(pulsein_tc_index);
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tc->COUNT16.CTRLBSET.reg = TC_CTRLBSET_CMD_RETRIGGER;
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overflow_count = 0;
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}
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refcount++;
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self->last_overflow = overflow_count;
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self->last_count = 0;
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set_eic_channel_data(pin->extint_channel, (void*) self);
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// Check to see if the EIC is enabled and start it up if its not.'
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if (eic_get_enable() == 0) {
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turn_on_external_interrupt_controller();
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}
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gpio_set_pin_function(pin->number, GPIO_PIN_FUNCTION_A);
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turn_on_cpu_interrupt(self->channel);
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claim_pin(pin);
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// Set config will enable the EIC.
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pulsein_set_config(self, true);
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#ifdef SAMD21
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rtc_start_pulse();
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#endif
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}
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bool common_hal_pulseio_pulsein_deinited(pulseio_pulsein_obj_t* self) {
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return self->pin == NO_PIN;
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}
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void common_hal_pulseio_pulsein_deinit(pulseio_pulsein_obj_t* self) {
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if (common_hal_pulseio_pulsein_deinited(self)) {
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return;
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}
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#ifdef SAMD21
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rtc_end_pulse();
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#endif
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set_eic_handler(self->channel, EIC_HANDLER_NO_INTERRUPT);
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turn_off_eic_channel(self->channel);
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reset_pin_number(self->pin);
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refcount--;
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if (refcount == 0) {
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tc_reset(tc_insts[pulsein_tc_index]);
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pulsein_tc_index = 0xff;
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}
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self->pin = NO_PIN;
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}
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void common_hal_pulseio_pulsein_pause(pulseio_pulsein_obj_t* self) {
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uint32_t mask = 1 << self->channel;
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EIC->INTENCLR.reg = mask << EIC_INTENSET_EXTINT_Pos;
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}
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void common_hal_pulseio_pulsein_resume(pulseio_pulsein_obj_t* self,
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uint16_t trigger_duration) {
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// Make sure we're paused.
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common_hal_pulseio_pulsein_pause(self);
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// Send the trigger pulse.
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if (trigger_duration > 0) {
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gpio_set_pin_pull_mode(self->pin, GPIO_PULL_OFF);
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gpio_set_pin_direction(self->pin, GPIO_DIRECTION_OUT);
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gpio_set_pin_level(self->pin, !self->idle_state);
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common_hal_mcu_delay_us((uint32_t)trigger_duration);
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gpio_set_pin_level(self->pin, self->idle_state);
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}
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// Reconfigure the pin and make sure its set to detect the first edge.
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self->first_edge = true;
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self->last_overflow = 0;
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self->last_count = 0;
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self->errored_too_fast = false;
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gpio_set_pin_function(self->pin, GPIO_PIN_FUNCTION_A);
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uint32_t mask = 1 << self->channel;
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// Clear previous interrupt state and re-enable it.
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EIC->INTFLAG.reg = mask << EIC_INTFLAG_EXTINT_Pos;
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EIC->INTENSET.reg = mask << EIC_INTENSET_EXTINT_Pos;
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pulsein_set_config(self, true);
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}
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void common_hal_pulseio_pulsein_clear(pulseio_pulsein_obj_t* self) {
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common_hal_mcu_disable_interrupts();
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self->start = 0;
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self->len = 0;
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common_hal_mcu_enable_interrupts();
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}
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uint16_t common_hal_pulseio_pulsein_popleft(pulseio_pulsein_obj_t* self) {
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if (self->len == 0) {
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mp_raise_IndexError_varg(translate("pop from empty %q"), MP_QSTR_PulseIn);
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}
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if (self->errored_too_fast) {
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self->errored_too_fast = 0;
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mp_raise_RuntimeError(translate("Input taking too long"));
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}
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common_hal_mcu_disable_interrupts();
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uint16_t value = self->buffer[self->start];
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self->start = (self->start + 1) % self->maxlen;
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self->len--;
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common_hal_mcu_enable_interrupts();
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return value;
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}
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uint16_t common_hal_pulseio_pulsein_get_maxlen(pulseio_pulsein_obj_t* self) {
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return self->maxlen;
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}
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uint16_t common_hal_pulseio_pulsein_get_len(pulseio_pulsein_obj_t* self) {
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return self->len;
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}
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bool common_hal_pulseio_pulsein_get_paused(pulseio_pulsein_obj_t* self) {
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uint32_t mask = 1 << self->channel;
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return (EIC->INTENSET.reg & (mask << EIC_INTENSET_EXTINT_Pos)) == 0;
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}
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uint16_t common_hal_pulseio_pulsein_get_item(pulseio_pulsein_obj_t* self,
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int16_t index) {
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common_hal_mcu_disable_interrupts();
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if (index < 0) {
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index += self->len;
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}
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if (index < 0 || index >= self->len) {
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common_hal_mcu_enable_interrupts();
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mp_raise_IndexError_varg(translate("%q index out of range"), MP_QSTR_PulseIn);
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}
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uint16_t value = self->buffer[(self->start + index) % self->maxlen];
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common_hal_mcu_enable_interrupts();
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return value;
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}
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