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 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 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 ***************************************************************************/ 103 104 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