67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
/* Bluetooth Audio Content Control */
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/*
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* Copyright (c) 2020 Bose Corporation
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* Copyright (c) 2021 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/bluetooth/att.h>
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#include <zephyr/bluetooth/gatt.h>
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#include <zephyr/bluetooth/uuid.h>
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#include "ccid_internal.h"
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uint8_t bt_ccid_get_value(void)
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{
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static uint8_t ccid_value;
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/* By spec, the CCID can take all values up to and including 0xFF.
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* But since this is a value we provide, we do not have to use all of
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* them. 254 CCID values on a device should be plenty, the last one
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* can be used to prevent wraparound.
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*/
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__ASSERT(ccid_value != UINT8_MAX,
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"Cannot allocate any more control control IDs");
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return ccid_value++;
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}
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struct ccid_search_param {
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const struct bt_gatt_attr *attr;
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uint8_t ccid;
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};
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static uint8_t ccid_attr_cb(const struct bt_gatt_attr *attr, uint16_t handle, void *user_data)
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{
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struct ccid_search_param *search_param = user_data;
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if (attr->read != NULL) {
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uint8_t ccid = 0U;
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ssize_t res;
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res = attr->read(NULL, attr, &ccid, sizeof(ccid), 0);
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if (res == sizeof(ccid) && search_param->ccid == ccid) {
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search_param->attr = attr;
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return BT_GATT_ITER_STOP;
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}
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}
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return BT_GATT_ITER_CONTINUE;
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}
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const struct bt_gatt_attr *bt_ccid_find_attr(uint8_t ccid)
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{
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struct ccid_search_param search_param = {
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.attr = NULL,
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.ccid = ccid,
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};
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bt_gatt_foreach_attr_type(BT_ATT_FIRST_ATTRIBUTE_HANDLE, BT_ATT_LAST_ATTRIBUTE_HANDLE,
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BT_UUID_CCID, NULL, 0, ccid_attr_cb, &search_param);
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return search_param.attr;
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}
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