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 38 #define MAX_CALLBACKS 10 39 40 static int g_connected; 41 static int g_num_deferred_callbacks; 42 static VCHIQ_CONNECTED_CALLBACK_T g_deferred_callback[MAX_CALLBACKS]; 43 static int g_once_init; 44 static struct mutex g_connected_mutex; 45 46 /**************************************************************************** 47 * 48 * Function to initialize our lock. 49 * 50 ***************************************************************************/ 51 52 static void connected_init(void) 53 { 54 if (!g_once_init) { 55 lmutex_init(&g_connected_mutex); 56 g_once_init = 1; 57 } 58 } 59 60 /**************************************************************************** 61 * 62 * This function is used to defer initialization until the vchiq stack is 63 * initialized. If the stack is already initialized, then the callback will 64 * be made immediately, otherwise it will be deferred until 65 * vchiq_call_connected_callbacks is called. 66 * 67 ***************************************************************************/ 68 69 void vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback) 70 { 71 connected_init(); 72 73 if (lmutex_lock_interruptible(&g_connected_mutex) != 0) 74 return; 75 76 if (g_connected) 77 /* We're already connected. Call the callback immediately. */ 78 79 callback(); 80 else { 81 if (g_num_deferred_callbacks >= MAX_CALLBACKS) 82 vchiq_log_error(vchiq_core_log_level, 83 "There are already %d callbacks registered - " 84 "please increase MAX_CALLBACKS", 85 g_num_deferred_callbacks); 86 else { 87 g_deferred_callback[g_num_deferred_callbacks] = 88 callback; 89 g_num_deferred_callbacks++; 90 } 91 } 92 lmutex_unlock(&g_connected_mutex); 93 } 94 95 /**************************************************************************** 96 * 97 * This function is called by the vchiq stack once it has been connected to 98 * the videocore and clients can start to use the stack. 99 * 100 ***************************************************************************/ 101 102 void vchiq_call_connected_callbacks(void) 103 { 104 int i; 105 106 connected_init(); 107 108 if (lmutex_lock_interruptible(&g_connected_mutex) != 0) 109 return; 110 111 for (i = 0; i < g_num_deferred_callbacks; i++) 112 g_deferred_callback[i](); 113 114 g_num_deferred_callbacks = 0; 115 g_connected = 1; 116 lmutex_unlock(&g_connected_mutex); 117 } 118 EXPORT_SYMBOL(vchiq_add_connected_callback); 119