xref: /btstack/src/ble/gatt-service/battery_service_server.c (revision ced70f9bfeafe291ec597a3a9cc862e39e0da3ce)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "battery_service_server.c"
39 
40 /**
41  * Implementation of the GATT Battery Service Server
42  * To use with your application, add `#import <battery_service.gatt>` to your .gatt file
43  */
44 
45 #include "btstack_defines.h"
46 #include "ble/att_db.h"
47 #include "ble/att_server.h"
48 #include "btstack_util.h"
49 #include "bluetooth_gatt.h"
50 #include "btstack_debug.h"
51 
52 
53 #include "ble/gatt-service/battery_service_server.h"
54 
55 static btstack_context_callback_registration_t  battery_callback;
56 static att_service_handler_t       battery_service;
57 
58 static uint8_t 	battery_value;
59 static uint16_t battery_value_client_configuration;
60 static hci_con_handle_t battery_value_client_configuration_connection;
61 
62 static uint16_t battery_value_handle;
63 static uint16_t battery_value_client_configuration_handle;
64 
65 
66 static uint16_t battery_service_read_callback(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t offset, uint8_t * buffer, uint16_t buffer_size){
67 	UNUSED(con_handle);
68 
69 	if (attribute_handle == battery_value_handle){
70 		return att_read_callback_handle_byte(battery_value, offset, buffer, buffer_size);
71 	}
72 	if (attribute_handle == battery_value_client_configuration_handle){
73 		return att_read_callback_handle_little_endian_16(battery_value_client_configuration, offset, buffer, buffer_size);
74 	}
75 	return 0;
76 }
77 
78 static int battery_service_write_callback(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size){
79 	UNUSED(offset);
80 	UNUSED(buffer_size);
81 
82     if (transaction_mode != ATT_TRANSACTION_MODE_NONE){
83         return 0;
84     }
85 
86     if (attribute_handle == battery_value_client_configuration_handle){
87 		battery_value_client_configuration = little_endian_read_16(buffer, 0);
88 		battery_value_client_configuration_connection = con_handle;
89 	}
90 	return 0;
91 }
92 
93 static void battery_service_can_send_now(void * context){
94 	hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context;
95 	att_server_notify(con_handle, battery_value_handle, &battery_value, 1);
96 }
97 
98 void battery_service_server_init(uint8_t value){
99 
100 	battery_value = value;
101 
102 	// get service handle range
103 	uint16_t start_handle = 0;
104 	uint16_t end_handle   = 0xffff;
105 	int service_found = gatt_server_get_handle_range_for_service_with_uuid16(ORG_BLUETOOTH_SERVICE_BATTERY_SERVICE, &start_handle, &end_handle);
106 	btstack_assert(service_found != 0);
107 	UNUSED(service_found);
108 
109 	// get characteristic value handle and client configuration handle
110 	battery_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_BATTERY_LEVEL);
111 	battery_value_client_configuration_handle = gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_BATTERY_LEVEL);
112 
113 	// register service with ATT Server
114 	battery_service.start_handle   = start_handle;
115 	battery_service.end_handle     = end_handle;
116 	battery_service.read_callback  = &battery_service_read_callback;
117 	battery_service.write_callback = &battery_service_write_callback;
118 	att_server_register_service_handler(&battery_service);
119 }
120 
121 void battery_service_server_set_battery_value(uint8_t value){
122 	battery_value = value;
123 	if (battery_value_client_configuration != 0){
124 		battery_callback.callback = &battery_service_can_send_now;
125 		battery_callback.context  = (void*) (uintptr_t) battery_value_client_configuration_connection;
126 		att_server_register_can_send_now_callback(&battery_callback, battery_value_client_configuration_connection);
127 	}
128 }
129