lib/utils: Add generic MicroPython IRQ helper functions.

Initial implementation of this is taken from the cc3200 port.

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_PTR(&mp_const_none_obj)} },
+    { 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 GC to prevent
+            // any memory allocations.
+            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();
+        } 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,
+};

lib/utils/mpirq.h

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Daniel Campora
+ *
+ * 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.
+ */
+#ifndef MICROPY_INCLUDED_LIB_UTILS_MPIRQ_H
+#define MICROPY_INCLUDED_LIB_UTILS_MPIRQ_H
+
+/******************************************************************************
+ DEFINE CONSTANTS
+ ******************************************************************************/
+
+enum {
+    MP_IRQ_ARG_INIT_handler = 0,
+    MP_IRQ_ARG_INIT_trigger,
+    MP_IRQ_ARG_INIT_hard,
+    MP_IRQ_ARG_INIT_NUM_ARGS,
+};
+
+/******************************************************************************
+ DEFINE TYPES
+ ******************************************************************************/
+
+typedef mp_obj_t (*mp_irq_init_t)(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
+typedef mp_uint_t (*mp_irq_uint_method_one_uint_para_t)(mp_obj_t self, mp_uint_t trigger);
+typedef mp_uint_t (*mp_irq_int_method_one_para_t)(mp_obj_t self, mp_uint_t info_type);
+
+enum {
+    MP_IRQ_INFO_FLAGS,
+    MP_IRQ_INFO_TRIGGERS,
+    MP_IRQ_INFO_CNT
+};
+
+typedef struct _mp_irq_methods_t {
+    mp_irq_init_t init;
+    mp_irq_uint_method_one_uint_para_t trigger;
+    mp_irq_int_method_one_para_t info;
+} mp_irq_methods_t;
+
+typedef struct _mp_irq_obj_t {
+    mp_obj_base_t base;
+    mp_irq_methods_t *methods;
+    mp_obj_t parent;
+    mp_obj_t handler;
+    bool ishard;
+} mp_irq_obj_t;
+
+/******************************************************************************
+ DECLARE EXPORTED DATA
+ ******************************************************************************/
+
+extern const mp_arg_t mp_irq_init_args[];
+extern const mp_obj_type_t mp_irq_type;
+
+/******************************************************************************
+ DECLARE PUBLIC FUNCTIONS
+ ******************************************************************************/
+
+mp_irq_obj_t *mp_irq_new(const mp_irq_methods_t *methods, mp_obj_t parent);
+void mp_irq_handler(mp_irq_obj_t *self);
+
+#endif // MICROPY_INCLUDED_LIB_UTILS_MPIRQ_H