1 /**
2 * Copyright (c) 2010-2012 Broadcom. All rights reserved.
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 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions, and the following disclaimer,
9 * without modification.
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. The names of the above-listed copyright holders may not be used
14 * to endorse or promote products derived from this software without
15 * specific prior written permission.
16 *
17 * ALTERNATIVELY, this software may be distributed under the terms of the
18 * GNU General Public License ("GPL") version 2, as published by the Free
19 * Software Foundation.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include "vchiq_connected.h"
35 #include "vchiq_core.h"
36 #include "vchiq_killable.h"
37 #include <linux/module.h>
38 #include <linux/mutex.h>
39
40 #define MAX_CALLBACKS 10
41
42 static int g_connected;
43 static int g_num_deferred_callbacks;
44 static VCHIQ_CONNECTED_CALLBACK_T g_deferred_callback[MAX_CALLBACKS];
45 static int g_once_init;
46 static struct mutex g_connected_mutex;
47
48 /****************************************************************************
49 *
50 * Function to initialize our lock.
51 *
52 ***************************************************************************/
53
connected_init(void)54 static void connected_init(void)
55 {
56 if (!g_once_init) {
57 mutex_init(&g_connected_mutex);
58 g_once_init = 1;
59 }
60 }
61
62 /****************************************************************************
63 *
64 * This function is used to defer initialization until the vchiq stack is
65 * initialized. If the stack is already initialized, then the callback will
66 * be made immediately, otherwise it will be deferred until
67 * vchiq_call_connected_callbacks is called.
68 *
69 ***************************************************************************/
70
vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)71 void vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)
72 {
73 connected_init();
74
75 if (mutex_lock_killable(&g_connected_mutex) != 0)
76 return;
77
78 if (g_connected)
79 /* We're already connected. Call the callback immediately. */
80
81 callback();
82 else {
83 if (g_num_deferred_callbacks >= MAX_CALLBACKS)
84 vchiq_log_error(vchiq_core_log_level,
85 "There already %d callback registered - "
86 "please increase MAX_CALLBACKS",
87 g_num_deferred_callbacks);
88 else {
89 g_deferred_callback[g_num_deferred_callbacks] =
90 callback;
91 g_num_deferred_callbacks++;
92 }
93 }
94 mutex_unlock(&g_connected_mutex);
95 }
96
97 /****************************************************************************
98 *
99 * This function is called by the vchiq stack once it has been connected to
100 * the videocore and clients can start to use the stack.
101 *
102 ***************************************************************************/
103
vchiq_call_connected_callbacks(void)104 void vchiq_call_connected_callbacks(void)
105 {
106 int i;
107
108 connected_init();
109
110 if (mutex_lock_killable(&g_connected_mutex) != 0)
111 return;
112
113 for (i = 0; i < g_num_deferred_callbacks; i++)
114 g_deferred_callback[i]();
115
116 g_num_deferred_callbacks = 0;
117 g_connected = 1;
118 mutex_unlock(&g_connected_mutex);
119 }
120 EXPORT_SYMBOL(vchiq_add_connected_callback);
121
