1 /** @file
2 * @brief GATT Battery Service
3 */
4
5 /*
6 * Copyright (c) 2024 Demant A/S
7 * Copyright (c) 2018 Nordic Semiconductor ASA
8 * Copyright (c) 2016 Intel Corporation
9 *
10 * SPDX-License-Identifier: Apache-2.0
11 */
12
13 #include <errno.h>
14 #include <zephyr/init.h>
15 #include <zephyr/sys/__assert.h>
16 #include <stdbool.h>
17 #include <zephyr/types.h>
18 #include <zephyr/sys/util.h>
19 #include <zephyr/sys/util_macro.h>
20
21 #include <zephyr/bluetooth/bluetooth.h>
22 #include <zephyr/bluetooth/conn.h>
23 #include <zephyr/bluetooth/gatt.h>
24 #include <zephyr/bluetooth/uuid.h>
25 #include <zephyr/bluetooth/services/bas.h>
26 #include "bas_internal.h"
27
28 #define LOG_LEVEL CONFIG_BT_BAS_LOG_LEVEL
29 #include <zephyr/logging/log.h>
30 LOG_MODULE_REGISTER(bas, CONFIG_BT_BAS_LOG_LEVEL);
31
32 static uint8_t battery_level = 100U;
33
blvl_ccc_cfg_changed(const struct bt_gatt_attr * attr,uint16_t value)34 static void blvl_ccc_cfg_changed(const struct bt_gatt_attr *attr, uint16_t value)
35 {
36 ARG_UNUSED(attr);
37
38 bool notif_enabled = (value == BT_GATT_CCC_NOTIFY);
39
40 LOG_INF("BAS Notifications %s", notif_enabled ? "enabled" : "disabled");
41 }
42
43 #if defined(CONFIG_BT_BAS_BLS)
blvl_status_ccc_cfg_changed(const struct bt_gatt_attr * attr,uint16_t value)44 static void blvl_status_ccc_cfg_changed(const struct bt_gatt_attr *attr, uint16_t value)
45 {
46 ARG_UNUSED(attr);
47
48 bool notif_enabled = (value == BT_GATT_CCC_NOTIFY);
49 bool ind_enabled = (value == BT_GATT_CCC_INDICATE);
50
51 LOG_INF("BAS Notifications %s", notif_enabled ? "enabled" : "disabled");
52 LOG_INF("BAS Indications %s", ind_enabled ? "enabled" : "disabled");
53 }
54 #endif
55
read_blvl(struct bt_conn * conn,const struct bt_gatt_attr * attr,void * buf,uint16_t len,uint16_t offset)56 static ssize_t read_blvl(struct bt_conn *conn, const struct bt_gatt_attr *attr, void *buf,
57 uint16_t len, uint16_t offset)
58 {
59 uint8_t lvl8 = battery_level;
60
61 return bt_gatt_attr_read(conn, attr, buf, len, offset, &lvl8, sizeof(lvl8));
62 }
63
64 /* Constant values from the Assigned Numbers specification:
65 * https://www.bluetooth.com/wp-content/uploads/Files/Specification/Assigned_Numbers.pdf?id=89
66 */
67 static const struct bt_gatt_cpf level_cpf = {
68 .format = 0x04, /* uint8 */
69 .exponent = 0x0,
70 .unit = 0x27AD, /* Percentage */
71 .name_space = 0x01, /* Bluetooth SIG */
72 .description = 0x0106, /* "main" */
73 };
74
75 BT_GATT_SERVICE_DEFINE(
76 bas, BT_GATT_PRIMARY_SERVICE(BT_UUID_BAS),
77 BT_GATT_CHARACTERISTIC(BT_UUID_BAS_BATTERY_LEVEL, BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY,
78 BT_GATT_PERM_READ, read_blvl, NULL, NULL),
79 BT_GATT_CCC(blvl_ccc_cfg_changed, BT_GATT_PERM_READ | BT_GATT_PERM_WRITE),
80 BT_GATT_CPF(&level_cpf),
81 #if defined(CONFIG_BT_BAS_BLS)
82 BT_GATT_CHARACTERISTIC(BT_UUID_BAS_BATTERY_LEVEL_STATUS,
83 BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY | BT_GATT_CHRC_INDICATE,
84 BT_GATT_PERM_READ, bt_bas_bls_read_blvl_status, NULL, NULL),
85 BT_GATT_CCC(blvl_status_ccc_cfg_changed, BT_GATT_PERM_READ | BT_GATT_PERM_WRITE),
86 #endif
87 #if defined(CONFIG_BT_BAS_BCS)
88 BT_GATT_CHARACTERISTIC(BT_UUID_BAS_BATTERY_CRIT_STATUS,
89 BT_GATT_CHRC_READ | BT_GATT_CHRC_INDICATE, BT_GATT_PERM_READ,
90 bt_bas_bcs_read_critical_status, NULL, NULL),
91 BT_GATT_CCC(bt_bas_bcs_ccc_cfg_changed, BT_GATT_PERM_READ | BT_GATT_PERM_WRITE),
92 #endif /* CONFIG_BT_BAS_BCS */
93 );
94
bas_init(void)95 static int bas_init(void)
96 {
97 if (IS_ENABLED(CONFIG_BT_BAS_BLS)) {
98 /* Initialize the Battery Level Status Module */
99 bt_bas_bls_init();
100 if (IS_ENABLED(CONFIG_BT_BAS_BLS_IDENTIFIER_PRESENT)) {
101 /* Set the identifier only if BT_BAS_BLS_IDENTIFIER_PRESENT is defined */
102 bt_bas_bls_set_identifier(level_cpf.description);
103 }
104 }
105 return 0;
106 }
107
bt_bas_get_battery_level(void)108 uint8_t bt_bas_get_battery_level(void)
109 {
110 return battery_level;
111 }
112
bt_bas_set_battery_level(uint8_t level)113 int bt_bas_set_battery_level(uint8_t level)
114 {
115 int rc;
116
117 if (level > 100U) {
118 return -EINVAL;
119 }
120
121 battery_level = level;
122
123 rc = bt_gatt_notify(NULL, &bas.attrs[1], &level, sizeof(level));
124
125 if (IS_ENABLED(CONFIG_BT_BAS_BLS_BATTERY_LEVEL_PRESENT)) {
126 bt_bas_bls_set_battery_level(level);
127 }
128
129 return rc == -ENOTCONN ? 0 : rc;
130 }
131
bt_bas_get_bas_attr(uint16_t index)132 const struct bt_gatt_attr *bt_bas_get_bas_attr(uint16_t index)
133 {
134 if (index < bas.attr_count) {
135 return &bas.attrs[index];
136 }
137 return NULL;
138 }
139
140 SYS_INIT(bas_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
141
