1 /******************************************************************************
2 *
3 * Copyright (C) 2009-2012 Broadcom Corporation
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 ******************************************************************************/
18
19 /*****************************************************************************
20 *
21 * Filename: btif_sm.c
22 *
23 * Description: Generic BTIF state machine API
24 *
25 *****************************************************************************/
26
27 #define LOG_TAG "bt_btif"
28
29 #include "btif_sm.h"
30
31 #include "btif_common.h"
32 #include "bt_common.h"
33 #include "osi/include/allocator.h"
34
35 /*****************************************************************************
36 ** Local type definitions
37 ******************************************************************************/
38 typedef struct {
39 btif_sm_state_t state;
40 btif_sm_handler_t *p_handlers;
41 } btif_sm_cb_t;
42
43 /*****************************************************************************
44 ** Functions
45 ******************************************************************************/
46
47 /*****************************************************************************
48 **
49 ** Function btif_sm_init
50 **
51 ** Description Initializes the state machine with the state handlers
52 ** The caller should ensure that the table and the corresponding
53 ** states match. The location that 'p_handlers' points to shall
54 ** be available until the btif_sm_shutdown API is invoked.
55 **
56 ** Returns Returns a pointer to the initialized state machine handle.
57 **
58 ******************************************************************************/
59
btif_sm_init(const btif_sm_handler_t * p_handlers,btif_sm_state_t initial_state)60 btif_sm_handle_t btif_sm_init(const btif_sm_handler_t *p_handlers, btif_sm_state_t initial_state)
61 {
62 if (p_handlers == NULL) {
63 BTIF_TRACE_ERROR("%s : p_handlers is NULL", __FUNCTION__);
64 return NULL;
65 }
66
67 btif_sm_cb_t *p_cb = (btif_sm_cb_t *)osi_malloc(sizeof(btif_sm_cb_t));
68 p_cb->state = initial_state;
69 p_cb->p_handlers = (btif_sm_handler_t*)p_handlers;
70
71 /* Send BTIF_SM_ENTER_EVT to the initial state */
72 p_cb->p_handlers[initial_state](BTIF_SM_ENTER_EVT, NULL);
73
74 return (btif_sm_handle_t)p_cb;
75 }
76
77 /*****************************************************************************
78 **
79 ** Function btif_sm_shutdown
80 **
81 ** Description Tears down the state machine
82 **
83 ** Returns None
84 **
85 ******************************************************************************/
btif_sm_shutdown(btif_sm_handle_t handle)86 void btif_sm_shutdown(btif_sm_handle_t handle)
87 {
88 btif_sm_cb_t *p_cb = (btif_sm_cb_t*)handle;
89
90 if (p_cb == NULL)
91 {
92 BTIF_TRACE_ERROR("%s : Invalid handle", __FUNCTION__);
93 return;
94 }
95 osi_free(p_cb);
96 }
97
98 /*****************************************************************************
99 **
100 ** Function btif_sm_get_state
101 **
102 ** Description Fetches the current state of the state machine
103 **
104 ** Returns Current state
105 **
106 ******************************************************************************/
btif_sm_get_state(btif_sm_handle_t handle)107 btif_sm_state_t btif_sm_get_state(btif_sm_handle_t handle)
108 {
109 btif_sm_cb_t *p_cb = (btif_sm_cb_t*)handle;
110
111 if (p_cb == NULL)
112 {
113 BTIF_TRACE_ERROR("%s : Invalid handle", __FUNCTION__);
114 return 0;
115 }
116
117 return p_cb->state;
118 }
119
120 /*****************************************************************************
121 **
122 ** Function btif_sm_dispatch
123 **
124 ** Description Dispatches the 'event' along with 'data' to the current state handler
125 **
126 ** Returns BT_STATUS_SUCCESS on success
127 ** BT_STATUS_UNHANDLED if event was not processed
128 ** BT_STATUS_FAIL otherwise
129 **
130 ******************************************************************************/
btif_sm_dispatch(btif_sm_handle_t handle,btif_sm_event_t event,void * data)131 bt_status_t btif_sm_dispatch(btif_sm_handle_t handle, btif_sm_event_t event,
132 void *data)
133 {
134 bt_status_t status = BT_STATUS_SUCCESS;
135
136 btif_sm_cb_t *p_cb = (btif_sm_cb_t*)handle;
137
138 if (p_cb == NULL)
139 {
140 BTIF_TRACE_ERROR("%s : Invalid handle", __FUNCTION__);
141 return BT_STATUS_FAIL;
142 }
143
144 if (p_cb->p_handlers[p_cb->state](event, data) == FALSE)
145 return BT_STATUS_UNHANDLED;
146
147 return status;
148 }
149
150 /*****************************************************************************
151 **
152 ** Function btif_sm_change_state
153 **
154 ** Description Make a transition to the new 'state'. The 'BTIF_SM_EXIT_EVT'
155 ** shall be invoked before exiting the current state. The
156 ** 'BTIF_SM_ENTER_EVT' shall be invoked before entering the new state
157 **
158 ** Returns BT_STATUS_SUCCESS on success
159 ** BT_STATUS_UNHANDLED if event was not processed
160 ** BT_STATUS_FAIL otherwise
161 **
162 ******************************************************************************/
btif_sm_change_state(btif_sm_handle_t handle,btif_sm_state_t state)163 bt_status_t btif_sm_change_state(btif_sm_handle_t handle, btif_sm_state_t state)
164 {
165 bt_status_t status = BT_STATUS_SUCCESS;
166 btif_sm_cb_t *p_cb = (btif_sm_cb_t*)handle;
167
168 if (p_cb == NULL)
169 {
170 BTIF_TRACE_ERROR("%s : Invalid handle", __FUNCTION__);
171 return BT_STATUS_FAIL;
172 }
173
174 /* Send exit event to the current state */
175 if (p_cb->p_handlers[p_cb->state](BTIF_SM_EXIT_EVT, NULL) == FALSE)
176 status = BT_STATUS_UNHANDLED;
177
178 /* Change to the new state */
179 p_cb->state = state;
180
181 /* Send enter event to the new state */
182 if (p_cb->p_handlers[p_cb->state](BTIF_SM_ENTER_EVT, NULL) == FALSE)
183 status = BT_STATUS_UNHANDLED;
184
185 return status;
186 }
187