circuitpython/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Scott Shawcroft 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 "py/runtime.h"
#include <hardware/regs/pio.h>
#include "common-hal/rotaryio/IncrementalEncoder.h"
#include "shared-module/rotaryio/IncrementalEncoder.h"
#include "bindings/rp2pio/__init__.h"
#include "bindings/rp2pio/StateMachine.h"
STATIC const uint16_t encoder[] = {
// again:
// in pins, 2
0x4002,
// mov x, isr
0xa026,
// jmp x!=y, push_data
0x00a5,
// mov isr, null
0xa0c3,
// jmp again
0x0000,
// push_data:
// push
0x8020,
// mov y, x
0xa041,
};
STATIC const uint16_t encoder_init[] = {
// set y, 31
0xe05f,
};
STATIC void incrementalencoder_interrupt_handler(void *self_in);
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void common_hal_rotaryio_incrementalencoder_construct(rotaryio_incrementalencoder_obj_t *self,
const mcu_pin_obj_t *pin_a, const mcu_pin_obj_t *pin_b) {
mp_obj_t pins[] = {MP_OBJ_FROM_PTR(pin_a), MP_OBJ_FROM_PTR(pin_b)};
// Start out with swapped to match behavior with other ports.
self->swapped = true;
if (!common_hal_rp2pio_pins_are_sequential(2, pins)) {
pins[0] = MP_OBJ_FROM_PTR(pin_b);
pins[1] = MP_OBJ_FROM_PTR(pin_a);
self->swapped = false;
if (!common_hal_rp2pio_pins_are_sequential(2, pins)) {
mp_raise_RuntimeError(translate("Pins must be sequential"));
}
}
self->position = 0;
self->quarter_count = 0;
common_hal_rp2pio_statemachine_construct(&self->state_machine,
encoder, MP_ARRAY_SIZE(encoder),
1000000,
encoder_init, MP_ARRAY_SIZE(encoder_init), // init
NULL, 0, 0, 0, // out pin
pins[0], 2, // in pins
3, 0, // in pulls
NULL, 0, 0, 0x1f, // set pins
NULL, 0, 0, 0x1f, // sideset pins
0, // wait gpio pins
true, // exclusive pin use
false, 32, false, // out settings
false, // Wait for txstall
false, 32, false); // in settings
common_hal_rp2pio_statemachine_run(&self->state_machine, encoder_init, MP_ARRAY_SIZE(encoder_init));
// We're guaranteed by the init code that some output will be available promptly
uint8_t quiescent_state;
common_hal_rp2pio_statemachine_readinto(&self->state_machine, &quiescent_state, 1, 1);
shared_module_softencoder_state_init(self, quiescent_state & 3);
common_hal_rp2pio_statemachine_set_interrupt_handler(&self->state_machine, incrementalencoder_interrupt_handler, self, PIO_IRQ0_INTF_SM0_RXNEMPTY_BITS);
}
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bool common_hal_rotaryio_incrementalencoder_deinited(rotaryio_incrementalencoder_obj_t *self) {
return common_hal_rp2pio_statemachine_deinited(&self->state_machine);
}
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void common_hal_rotaryio_incrementalencoder_deinit(rotaryio_incrementalencoder_obj_t *self) {
if (common_hal_rotaryio_incrementalencoder_deinited(self)) {
return;
}
common_hal_rp2pio_statemachine_set_interrupt_handler(&self->state_machine, NULL, NULL, 0);
common_hal_rp2pio_statemachine_deinit(&self->state_machine);
}
STATIC void incrementalencoder_interrupt_handler(void *self_in) {
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rotaryio_incrementalencoder_obj_t *self = self_in;
while (common_hal_rp2pio_statemachine_get_in_waiting(&self->state_machine)) {
// Bypass all the logic of StateMachine.c:_transfer, we need something
// very simple and fast for an interrupt!
uint8_t new_state = self->state_machine.pio->rxf[self->state_machine.state_machine];
if (self->swapped) {
if (new_state == 0x1) {
new_state = 0x2;
} else if (new_state == 0x2) {
new_state = 0x1;
}
}
shared_module_softencoder_state_update(self, new_state);
}
}