| 1 | /* |
| 2 | * ALSA sequencer MIDI-through client |
| 3 | * Copyright (c) 1999-2000 by Takashi Iwai <tiwai@suse.de> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <sound/driver.h> |
| 22 | #include <linux/init.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <linux/moduleparam.h> |
| 25 | #include <sound/core.h> |
| 26 | #include "seq_clientmgr.h" |
| 27 | #include <sound/initval.h> |
| 28 | #include <sound/asoundef.h> |
| 29 | |
| 30 | /* |
| 31 | |
| 32 | Sequencer MIDI-through client |
| 33 | |
| 34 | This gives a simple midi-through client. All the normal input events |
| 35 | are redirected to output port immediately. |
| 36 | The routing can be done via aconnect program in alsa-utils. |
| 37 | |
| 38 | Each client has a static client number 62 (= SNDRV_SEQ_CLIENT_DUMMY). |
| 39 | If you want to auto-load this module, you may add the following alias |
| 40 | in your /etc/conf.modules file. |
| 41 | |
| 42 | alias snd-seq-client-62 snd-seq-dummy |
| 43 | |
| 44 | The module is loaded on demand for client 62, or /proc/asound/seq/ |
| 45 | is accessed. If you don't need this module to be loaded, alias |
| 46 | snd-seq-client-62 as "off". This will help modprobe. |
| 47 | |
| 48 | The number of ports to be created can be specified via the module |
| 49 | parameter "ports". For example, to create four ports, add the |
| 50 | following option in /etc/modprobe.conf: |
| 51 | |
| 52 | option snd-seq-dummy ports=4 |
| 53 | |
| 54 | The modle option "duplex=1" enables duplex operation to the port. |
| 55 | In duplex mode, a pair of ports are created instead of single port, |
| 56 | and events are tunneled between pair-ports. For example, input to |
| 57 | port A is sent to output port of another port B and vice versa. |
| 58 | In duplex mode, each port has DUPLEX capability. |
| 59 | |
| 60 | */ |
| 61 | |
| 62 | |
| 63 | MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); |
| 64 | MODULE_DESCRIPTION("ALSA sequencer MIDI-through client"); |
| 65 | MODULE_LICENSE("GPL"); |
| 66 | MODULE_ALIAS("snd-seq-client-" __stringify(SNDRV_SEQ_CLIENT_DUMMY)); |
| 67 | |
| 68 | static int ports = 1; |
| 69 | static int duplex = 0; |
| 70 | |
| 71 | module_param(ports, int, 0444); |
| 72 | MODULE_PARM_DESC(ports, "number of ports to be created"); |
| 73 | module_param(duplex, bool, 0444); |
| 74 | MODULE_PARM_DESC(duplex, "create DUPLEX ports"); |
| 75 | |
| 76 | struct snd_seq_dummy_port { |
| 77 | int client; |
| 78 | int port; |
| 79 | int duplex; |
| 80 | int connect; |
| 81 | }; |
| 82 | |
| 83 | static int my_client = -1; |
| 84 | |
| 85 | /* |
| 86 | * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events |
| 87 | * to subscribers. |
| 88 | * Note: this callback is called only after all subscribers are removed. |
| 89 | */ |
| 90 | static int |
| 91 | dummy_unuse(void *private_data, struct snd_seq_port_subscribe *info) |
| 92 | { |
| 93 | struct snd_seq_dummy_port *p; |
| 94 | int i; |
| 95 | struct snd_seq_event ev; |
| 96 | |
| 97 | p = private_data; |
| 98 | memset(&ev, 0, sizeof(ev)); |
| 99 | if (p->duplex) |
| 100 | ev.source.port = p->connect; |
| 101 | else |
| 102 | ev.source.port = p->port; |
| 103 | ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; |
| 104 | ev.type = SNDRV_SEQ_EVENT_CONTROLLER; |
| 105 | for (i = 0; i < 16; i++) { |
| 106 | ev.data.control.channel = i; |
| 107 | ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF; |
| 108 | snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0); |
| 109 | ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS; |
| 110 | snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0); |
| 111 | } |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | /* |
| 116 | * event input callback - just redirect events to subscribers |
| 117 | */ |
| 118 | static int |
| 119 | dummy_input(struct snd_seq_event *ev, int direct, void *private_data, |
| 120 | int atomic, int hop) |
| 121 | { |
| 122 | struct snd_seq_dummy_port *p; |
| 123 | struct snd_seq_event tmpev; |
| 124 | |
| 125 | p = private_data; |
| 126 | if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM || |
| 127 | ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR) |
| 128 | return 0; /* ignore system messages */ |
| 129 | tmpev = *ev; |
| 130 | if (p->duplex) |
| 131 | tmpev.source.port = p->connect; |
| 132 | else |
| 133 | tmpev.source.port = p->port; |
| 134 | tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; |
| 135 | return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop); |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * free_private callback |
| 140 | */ |
| 141 | static void |
| 142 | dummy_free(void *private_data) |
| 143 | { |
| 144 | kfree(private_data); |
| 145 | } |
| 146 | |
| 147 | /* |
| 148 | * create a port |
| 149 | */ |
| 150 | static struct snd_seq_dummy_port __init * |
| 151 | create_port(int idx, int type) |
| 152 | { |
| 153 | struct snd_seq_port_info pinfo; |
| 154 | struct snd_seq_port_callback pcb; |
| 155 | struct snd_seq_dummy_port *rec; |
| 156 | |
| 157 | if ((rec = kzalloc(sizeof(*rec), GFP_KERNEL)) == NULL) |
| 158 | return NULL; |
| 159 | |
| 160 | rec->client = my_client; |
| 161 | rec->duplex = duplex; |
| 162 | rec->connect = 0; |
| 163 | memset(&pinfo, 0, sizeof(pinfo)); |
| 164 | pinfo.addr.client = my_client; |
| 165 | if (duplex) |
| 166 | sprintf(pinfo.name, "Midi Through Port-%d:%c", idx, |
| 167 | (type ? 'B' : 'A')); |
| 168 | else |
| 169 | sprintf(pinfo.name, "Midi Through Port-%d", idx); |
| 170 | pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ; |
| 171 | pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE; |
| 172 | if (duplex) |
| 173 | pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX; |
| 174 | pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC; |
| 175 | memset(&pcb, 0, sizeof(pcb)); |
| 176 | pcb.owner = THIS_MODULE; |
| 177 | pcb.unuse = dummy_unuse; |
| 178 | pcb.event_input = dummy_input; |
| 179 | pcb.private_free = dummy_free; |
| 180 | pcb.private_data = rec; |
| 181 | pinfo.kernel = &pcb; |
| 182 | if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) { |
| 183 | kfree(rec); |
| 184 | return NULL; |
| 185 | } |
| 186 | rec->port = pinfo.addr.port; |
| 187 | return rec; |
| 188 | } |
| 189 | |
| 190 | /* |
| 191 | * register client and create ports |
| 192 | */ |
| 193 | static int __init |
| 194 | register_client(void) |
| 195 | { |
| 196 | struct snd_seq_dummy_port *rec1, *rec2; |
| 197 | int i; |
| 198 | |
| 199 | if (ports < 1) { |
| 200 | snd_printk(KERN_ERR "invalid number of ports %d\n", ports); |
| 201 | return -EINVAL; |
| 202 | } |
| 203 | |
| 204 | /* create client */ |
| 205 | my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY, |
| 206 | "Midi Through"); |
| 207 | if (my_client < 0) |
| 208 | return my_client; |
| 209 | |
| 210 | /* create ports */ |
| 211 | for (i = 0; i < ports; i++) { |
| 212 | rec1 = create_port(i, 0); |
| 213 | if (rec1 == NULL) { |
| 214 | snd_seq_delete_kernel_client(my_client); |
| 215 | return -ENOMEM; |
| 216 | } |
| 217 | if (duplex) { |
| 218 | rec2 = create_port(i, 1); |
| 219 | if (rec2 == NULL) { |
| 220 | snd_seq_delete_kernel_client(my_client); |
| 221 | return -ENOMEM; |
| 222 | } |
| 223 | rec1->connect = rec2->port; |
| 224 | rec2->connect = rec1->port; |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * delete client if exists |
| 233 | */ |
| 234 | static void __exit |
| 235 | delete_client(void) |
| 236 | { |
| 237 | if (my_client >= 0) |
| 238 | snd_seq_delete_kernel_client(my_client); |
| 239 | } |
| 240 | |
| 241 | /* |
| 242 | * Init part |
| 243 | */ |
| 244 | |
| 245 | static int __init alsa_seq_dummy_init(void) |
| 246 | { |
| 247 | int err; |
| 248 | snd_seq_autoload_lock(); |
| 249 | err = register_client(); |
| 250 | snd_seq_autoload_unlock(); |
| 251 | return err; |
| 252 | } |
| 253 | |
| 254 | static void __exit alsa_seq_dummy_exit(void) |
| 255 | { |
| 256 | delete_client(); |
| 257 | } |
| 258 | |
| 259 | module_init(alsa_seq_dummy_init) |
| 260 | module_exit(alsa_seq_dummy_exit) |