1 /* 2 * ALSA sequencer System services Client 3 * Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl> 4 * 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 * 20 */ 21 22 #include <linux/init.h> 23 #include <sound/core.h> 24 #include "seq_system.h" 25 #include "seq_timer.h" 26 #include "seq_queue.h" 27 28 /* internal client that provide system services, access to timer etc. */ 29 30 /* 31 * Port "Timer" 32 * - send tempo /start/stop etc. events to this port to manipulate the 33 * queue's timer. The queue address is specified in 34 * data.queue.queue. 35 * - this port supports subscription. The received timer events are 36 * broadcasted to all subscribed clients. The modified tempo 37 * value is stored on data.queue.value. 38 * The modifier client/port is not send. 39 * 40 * Port "Announce" 41 * - does not receive message 42 * - supports supscription. For each client or port attaching to or 43 * detaching from the system an announcement is send to the subscribed 44 * clients. 45 * 46 * Idea: the subscription mechanism might also work handy for distributing 47 * synchronisation and timing information. In this case we would ideally have 48 * a list of subscribers for each type of sync (time, tick), for each timing 49 * queue. 50 * 51 * NOTE: the queue to be started, stopped, etc. must be specified 52 * in data.queue.addr.queue field. queue is used only for 53 * scheduling, and no longer referred as affected queue. 54 * They are used only for timer broadcast (see above). 55 * -- iwai 56 */ 57 58 59 /* client id of our system client */ 60 static int sysclient = -1; 61 62 /* port id numbers for this client */ 63 static int announce_port = -1; 64 65 66 67 /* fill standard header data, source port & channel are filled in */ 68 static int setheader(struct snd_seq_event * ev, int client, int port) 69 { 70 if (announce_port < 0) 71 return -ENODEV; 72 73 memset(ev, 0, sizeof(struct snd_seq_event)); 74 75 ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK; 76 ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED; 77 78 ev->source.client = sysclient; 79 ev->source.port = announce_port; 80 ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; 81 82 /* fill data */ 83 /*ev->data.addr.queue = SNDRV_SEQ_ADDRESS_UNKNOWN;*/ 84 ev->data.addr.client = client; 85 ev->data.addr.port = port; 86 87 return 0; 88 } 89 90 91 /* entry points for broadcasting system events */ 92 void snd_seq_system_broadcast(int client, int port, int type) 93 { 94 struct snd_seq_event ev; 95 96 if (setheader(&ev, client, port) < 0) 97 return; 98 ev.type = type; 99 snd_seq_kernel_client_dispatch(sysclient, &ev, 0, 0); 100 } 101 102 /* entry points for broadcasting system events */ 103 int snd_seq_system_notify(int client, int port, struct snd_seq_event *ev) 104 { 105 ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED; 106 ev->source.client = sysclient; 107 ev->source.port = announce_port; 108 ev->dest.client = client; 109 ev->dest.port = port; 110 return snd_seq_kernel_client_dispatch(sysclient, ev, 0, 0); 111 } 112 113 /* call-back handler for timer events */ 114 static int event_input_timer(struct snd_seq_event * ev, int direct, void *private_data, int atomic, int hop) 115 { 116 return snd_seq_control_queue(ev, atomic, hop); 117 } 118 119 /* register our internal client */ 120 int __init snd_seq_system_client_init(void) 121 { 122 struct snd_seq_port_callback pcallbacks; 123 struct snd_seq_port_info *port; 124 125 port = kzalloc(sizeof(*port), GFP_KERNEL); 126 if (!port) 127 return -ENOMEM; 128 129 memset(&pcallbacks, 0, sizeof(pcallbacks)); 130 pcallbacks.owner = THIS_MODULE; 131 pcallbacks.event_input = event_input_timer; 132 133 /* register client */ 134 sysclient = snd_seq_create_kernel_client(NULL, 0, "System"); 135 136 /* register timer */ 137 strcpy(port->name, "Timer"); 138 port->capability = SNDRV_SEQ_PORT_CAP_WRITE; /* accept queue control */ 139 port->capability |= SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast */ 140 port->kernel = &pcallbacks; 141 port->type = 0; 142 port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT; 143 port->addr.client = sysclient; 144 port->addr.port = SNDRV_SEQ_PORT_SYSTEM_TIMER; 145 snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT, port); 146 147 /* register announcement port */ 148 strcpy(port->name, "Announce"); 149 port->capability = SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast only */ 150 port->kernel = NULL; 151 port->type = 0; 152 port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT; 153 port->addr.client = sysclient; 154 port->addr.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE; 155 snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT, port); 156 announce_port = port->addr.port; 157 158 kfree(port); 159 return 0; 160 } 161 162 163 /* unregister our internal client */ 164 void __exit snd_seq_system_client_done(void) 165 { 166 int oldsysclient = sysclient; 167 168 if (oldsysclient >= 0) { 169 sysclient = -1; 170 announce_port = -1; 171 snd_seq_delete_kernel_client(oldsysclient); 172 } 173 } 174