circuitpython/shared-bindings/microcontroller/Pin.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Scott Shawcroft
 *
 * 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 "shared-bindings/board/__init__.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "shared-bindings/microcontroller/Pin.h"

#include "py/nlr.h"
#include "py/obj.h"
#include "py/runtime.h"
#include "supervisor/shared/translate.h"

//| class Pin:
//|     """Identifies an IO pin on the microcontroller."""
//|
//|     def __init__(self, ):
//|         """Identifies an IO pin on the microcontroller. They are fixed by the
//|         hardware so they cannot be constructed on demand. Instead, use
//|         `board` or `microcontroller.pin` to reference the desired pin."""
//|         ...
//|

static void get_pin_name(const mcu_pin_obj_t *self, qstr* package, qstr* module, qstr* name) {
    const mp_map_t* board_map = &board_module_globals.map;
    for (uint8_t i = 0; i < board_map->alloc; i++) {
        if (board_map->table[i].value == self) {
            *package = 0;
            *module = MP_QSTR_board;
            *name = MP_OBJ_QSTR_VALUE(board_map->table[i].key);
            return;
        }
    }
    const mp_map_t* mcu_map = &mcu_pin_globals.map;
    for (uint8_t i = 0; i < mcu_map->alloc; i++) {
        if (mcu_map->table[i].value == self) {
            *package = MP_QSTR_microcontroller;
            *module = MP_QSTR_pin;
            *name = MP_OBJ_QSTR_VALUE(mcu_map->table[i].key);
            return;
        }
    }
}

STATIC void mcu_pin_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
    mcu_pin_obj_t *self = MP_OBJ_TO_PTR(self_in);
    qstr package;
    qstr module;
    qstr name;

    get_pin_name(self, &package, &module, &name);
    mp_printf(print, "%q.%q.%q", MP_QSTR_microcontroller, MP_QSTR_pin, name);
}

const mp_obj_type_t mcu_pin_type = {
    { &mp_type_type },
    .name = MP_QSTR_Pin,
    .print = mcu_pin_print
};

mcu_pin_obj_t *validate_obj_is_pin(mp_obj_t obj) {
    if (!MP_OBJ_IS_TYPE(obj, &mcu_pin_type)) {
        mp_raise_TypeError_varg(translate("Expected a %q"), mcu_pin_type.name);
    }
    return MP_OBJ_TO_PTR(obj);
}

// Validate that the obj is a pin or None. Return an mcu_pin_obj_t* or NULL, correspondingly.
mcu_pin_obj_t *validate_obj_is_pin_or_none(mp_obj_t obj) {
    if (obj == mp_const_none) {
        return NULL;
    }
    return validate_obj_is_pin(obj);
}

mcu_pin_obj_t *validate_obj_is_free_pin(mp_obj_t obj) {
    mcu_pin_obj_t *pin = validate_obj_is_pin(obj);
    assert_pin_free(pin);
    return pin;
}

// Validate every element in the list to be a free pin.
void validate_list_is_free_pins(qstr what, mcu_pin_obj_t **pins_out, mp_int_t max_pins, mp_obj_t seq, uint8_t *count_out) {
    mp_int_t len = MP_OBJ_SMALL_INT_VALUE(mp_obj_len(seq));
    if (len > max_pins) {
        mp_raise_ValueError_varg(translate("At most %d %q may be specified (not %d)"), max_pins, what, len);
    }
    *count_out = len;
    for (mp_int_t i=0; i<len; i++) {
        pins_out[i] = validate_obj_is_free_pin(mp_obj_subscr(seq, MP_OBJ_NEW_SMALL_INT(i), MP_OBJ_SENTINEL));
    }
}

// Validate that the obj is a free pin or None. Return an mcu_pin_obj_t* or NULL, correspondingly.
mcu_pin_obj_t *validate_obj_is_free_pin_or_none(mp_obj_t obj) {
    if (obj == mp_const_none) {
        return NULL;
    }
    mcu_pin_obj_t *pin = validate_obj_is_pin(obj);
    assert_pin_free(pin);
    return pin;
}

void assert_pin_free(const mcu_pin_obj_t* pin) {
    if (pin != NULL && pin != MP_OBJ_TO_PTR(mp_const_none) && !common_hal_mcu_pin_is_free(pin)) {
        qstr package;
        qstr module;
        qstr name;

        get_pin_name(pin, &package, &module, &name);
        mp_raise_ValueError_varg(translate("%q in use"), name);
    }
}