circuitpython/ports/silabs/common-hal/_bleio/Descriptor.c

/*
 * This file is part of Adafruit for EFR32 project
 *
 * The MIT License (MIT)
 *
 * Copyright 2023 Silicon Laboratories Inc. www.silabs.com
 *
 * 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 "shared-bindings/_bleio/__init__.h"
#include "shared-bindings/_bleio/Descriptor.h"
#include "shared-bindings/_bleio/Service.h"
#include "shared-bindings/_bleio/UUID.h"

void common_hal_bleio_descriptor_construct(
    bleio_descriptor_obj_t *self,
    bleio_characteristic_obj_t *characteristic,
    bleio_uuid_obj_t *uuid,
    bleio_attribute_security_mode_t read_perm,
    bleio_attribute_security_mode_t write_perm,
    mp_int_t max_length, bool fixed_length,
    mp_buffer_info_t *initial_value_bufinfo) {

    const mp_int_t max_length_max = BLE_ATT_ATTR_MAX_LEN;
    self->uuid = uuid;
    self->handle = BLEIO_HANDLE_INVALID;
    self->read_perm = read_perm;
    self->write_perm = write_perm;
    self->initial_value = mp_obj_new_bytes(initial_value_bufinfo->buf,
        initial_value_bufinfo->len);

    if (max_length < 0 || max_length > max_length_max) {
        mp_raise_ValueError_varg(
            MP_ERROR_TEXT("max_length must be 0-%d when fixed_length is %s"),
            max_length_max, fixed_length ? "True" : "False");
    }
    self->max_length = max_length;
    self->fixed_length = fixed_length;
}

//  Get descriptor uuid
bleio_uuid_obj_t *common_hal_bleio_descriptor_get_uuid(
    bleio_descriptor_obj_t *self) {
    return self->uuid;
}

bleio_characteristic_obj_t *common_hal_bleio_descriptor_get_characteristic(
    bleio_descriptor_obj_t *self) {
    return self->characteristic;
}

size_t common_hal_bleio_descriptor_get_value(bleio_descriptor_obj_t *self,
    uint8_t *buf, size_t len) {

    uint16_t conn_handle;
    if (self->handle != BLE_GATT_HANDLE_INVALID) {
        conn_handle = bleio_connection_get_conn_handle(
            self->characteristic->service->connection);
        if (common_hal_bleio_service_get_is_remote(
            self->characteristic->service)) {

            sl_bt_gatt_read_descriptor_value(conn_handle, self->handle);
        }
    }

    return 0;
}

// Set value to descriptor
void common_hal_bleio_descriptor_set_value(bleio_descriptor_obj_t *self,
    mp_buffer_info_t *bufinfo) {

    uint16_t conn_handle;
    if (self->handle != BLE_GATT_HANDLE_INVALID) {
        conn_handle = bleio_connection_get_conn_handle(
            self->characteristic->service->connection);
        if (common_hal_bleio_service_get_is_remote(
            self->characteristic->service)) {

            // false means WRITE_REQ, not write-no-response
            sl_bt_gatt_write_descriptor_value(conn_handle,
                self->handle,
                bufinfo->len,
                bufinfo->buf);
        } else {
            // Validate data length for local descriptors only.
            if (self->fixed_length && bufinfo->len != self->max_length) {
                mp_raise_ValueError(
                    MP_ERROR_TEXT("Value length != required fixed length"));
            }
            if (bufinfo->len > self->max_length) {
                mp_raise_ValueError(MP_ERROR_TEXT("Value length > max_length"));
            }
        }
    }
}