circuitpython/lib/utils/mpirq.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Daniel Campora
 *               2018 Tobias Badertscher
 *
 * 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 <stdio.h>

#include "py/runtime.h"
#include "py/gc.h"
#include "lib/utils/mpirq.h"

/******************************************************************************
 DECLARE PUBLIC DATA
 ******************************************************************************/

const mp_arg_t mp_irq_init_args[] = {
    { MP_QSTR_handler, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
    { MP_QSTR_trigger, MP_ARG_INT, {.u_int = 0} },
    { MP_QSTR_hard, MP_ARG_BOOL, {.u_bool = false} },
};

/******************************************************************************
 DECLARE PRIVATE DATA
 ******************************************************************************/

/******************************************************************************
 DEFINE PUBLIC FUNCTIONS
 ******************************************************************************/

mp_irq_obj_t *mp_irq_new(const mp_irq_methods_t *methods, mp_obj_t parent) {
    mp_irq_obj_t *self = m_new0(mp_irq_obj_t, 1);
    self->base.type = &mp_irq_type;
    self->methods = (mp_irq_methods_t *)methods;
    self->parent = parent;
    self->handler = mp_const_none;
    self->ishard = false;
    return self;
}

void mp_irq_handler(mp_irq_obj_t *self) {
    if (self->handler != mp_const_none) {
        if (self->ishard) {
            // When executing code within a handler we must lock the scheduler to
            // prevent any scheduled callbacks from running, and lock the GC to
            // prevent any memory allocations.
            mp_sched_lock();
            gc_lock();
            nlr_buf_t nlr;
            if (nlr_push(&nlr) == 0) {
                mp_call_function_1(self->handler, self->parent);
                nlr_pop();
            } else {
                // Uncaught exception; disable the callback so that it doesn't run again
                self->methods->trigger(self->parent, 0);
                self->handler = mp_const_none;
                printf("Uncaught exception in IRQ callback handler\n");
                mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(nlr.ret_val));
            }
            gc_unlock();
            mp_sched_unlock();
        } else {
            // Schedule call to user function
            mp_sched_schedule(self->handler, self->parent);
        }
    }
}

/******************************************************************************/
// MicroPython bindings

STATIC mp_obj_t mp_irq_flags(mp_obj_t self_in) {
    mp_irq_obj_t *self = MP_OBJ_TO_PTR(self_in);
    return mp_obj_new_int(self->methods->info(self->parent, MP_IRQ_INFO_FLAGS));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mp_irq_flags_obj, mp_irq_flags);

STATIC mp_obj_t mp_irq_trigger(size_t n_args, const mp_obj_t *args) {
    mp_irq_obj_t *self = MP_OBJ_TO_PTR(args[0]);
    mp_obj_t ret_obj = mp_obj_new_int(self->methods->info(self->parent, MP_IRQ_INFO_TRIGGERS));
    if (n_args == 2) {
        // Set trigger
        self->methods->trigger(self->parent, mp_obj_get_int(args[1]));
    }
    return ret_obj;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_irq_trigger_obj, 1, 2, mp_irq_trigger);

STATIC mp_obj_t mp_irq_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
    mp_arg_check_num(n_args, n_kw, 0, 0, false);
    mp_irq_handler(MP_OBJ_TO_PTR(self_in));
    return mp_const_none;
}

STATIC const mp_rom_map_elem_t mp_irq_locals_dict_table[] = {
    { MP_ROM_QSTR(MP_QSTR_flags),               MP_ROM_PTR(&mp_irq_flags_obj) },
    { MP_ROM_QSTR(MP_QSTR_trigger),             MP_ROM_PTR(&mp_irq_trigger_obj) },
};
STATIC MP_DEFINE_CONST_DICT(mp_irq_locals_dict, mp_irq_locals_dict_table);

const mp_obj_type_t mp_irq_type = {
    { &mp_type_type },
    .name = MP_QSTR_irq,
    .call = mp_irq_call,
    .locals_dict = (mp_obj_dict_t *)&mp_irq_locals_dict,
};