1 /* 2 * Dummy soundcard for virtual rawmidi devices 3 * 4 * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de> 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 /* 23 * VIRTUAL RAW MIDI DEVICE CARDS 24 * 25 * This dummy card contains up to 4 virtual rawmidi devices. 26 * They are not real rawmidi devices but just associated with sequencer 27 * clients, so that any input/output sources can be connected as a raw 28 * MIDI device arbitrary. 29 * Also, multiple access is allowed to a single rawmidi device. 30 * 31 * Typical usage is like following: 32 * - Load snd-virmidi module. 33 * # modprobe snd-virmidi index=2 34 * Then, sequencer clients 72:0 to 75:0 will be created, which are 35 * mapped from /dev/snd/midiC1D0 to /dev/snd/midiC1D3, respectively. 36 * 37 * - Connect input/output via aconnect. 38 * % aconnect 64:0 72:0 # keyboard input redirection 64:0 -> 72:0 39 * % aconnect 72:0 65:0 # output device redirection 72:0 -> 65:0 40 * 41 * - Run application using a midi device (eg. /dev/snd/midiC1D0) 42 */ 43 44 #include <linux/init.h> 45 #include <linux/wait.h> 46 #include <linux/err.h> 47 #include <linux/platform_device.h> 48 #include <linux/module.h> 49 #include <sound/core.h> 50 #include <sound/seq_kernel.h> 51 #include <sound/seq_virmidi.h> 52 #include <sound/initval.h> 53 54 /* hack: OSS defines midi_devs, so undefine it (versioned symbols) */ 55 #undef midi_devs 56 57 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); 58 MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices"); 59 MODULE_LICENSE("GPL"); 60 MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual rawmidi device}}"); 61 62 #define MAX_MIDI_DEVICES 4 63 64 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ 65 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ 66 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; 67 static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 4}; 68 69 module_param_array(index, int, NULL, 0444); 70 MODULE_PARM_DESC(index, "Index value for virmidi soundcard."); 71 module_param_array(id, charp, NULL, 0444); 72 MODULE_PARM_DESC(id, "ID string for virmidi soundcard."); 73 module_param_array(enable, bool, NULL, 0444); 74 MODULE_PARM_DESC(enable, "Enable this soundcard."); 75 module_param_array(midi_devs, int, NULL, 0444); 76 MODULE_PARM_DESC(midi_devs, "MIDI devices # (1-4)"); 77 78 struct snd_card_virmidi { 79 struct snd_card *card; 80 struct snd_rawmidi *midi[MAX_MIDI_DEVICES]; 81 }; 82 83 static struct platform_device *devices[SNDRV_CARDS]; 84 85 86 static int snd_virmidi_probe(struct platform_device *devptr) 87 { 88 struct snd_card *card; 89 struct snd_card_virmidi *vmidi; 90 int idx, err; 91 int dev = devptr->id; 92 93 err = snd_card_create(index[dev], id[dev], THIS_MODULE, 94 sizeof(struct snd_card_virmidi), &card); 95 if (err < 0) 96 return err; 97 vmidi = card->private_data; 98 vmidi->card = card; 99 100 if (midi_devs[dev] > MAX_MIDI_DEVICES) { 101 snd_printk(KERN_WARNING 102 "too much midi devices for virmidi %d: " 103 "force to use %d\n", dev, MAX_MIDI_DEVICES); 104 midi_devs[dev] = MAX_MIDI_DEVICES; 105 } 106 for (idx = 0; idx < midi_devs[dev]; idx++) { 107 struct snd_rawmidi *rmidi; 108 struct snd_virmidi_dev *rdev; 109 if ((err = snd_virmidi_new(card, idx, &rmidi)) < 0) 110 goto __nodev; 111 rdev = rmidi->private_data; 112 vmidi->midi[idx] = rmidi; 113 strcpy(rmidi->name, "Virtual Raw MIDI"); 114 rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH; 115 } 116 117 strcpy(card->driver, "VirMIDI"); 118 strcpy(card->shortname, "VirMIDI"); 119 sprintf(card->longname, "Virtual MIDI Card %i", dev + 1); 120 121 snd_card_set_dev(card, &devptr->dev); 122 123 if ((err = snd_card_register(card)) == 0) { 124 platform_set_drvdata(devptr, card); 125 return 0; 126 } 127 __nodev: 128 snd_card_free(card); 129 return err; 130 } 131 132 static int snd_virmidi_remove(struct platform_device *devptr) 133 { 134 snd_card_free(platform_get_drvdata(devptr)); 135 platform_set_drvdata(devptr, NULL); 136 return 0; 137 } 138 139 #define SND_VIRMIDI_DRIVER "snd_virmidi" 140 141 static struct platform_driver snd_virmidi_driver = { 142 .probe = snd_virmidi_probe, 143 .remove = snd_virmidi_remove, 144 .driver = { 145 .name = SND_VIRMIDI_DRIVER, 146 .owner = THIS_MODULE, 147 }, 148 }; 149 150 static void snd_virmidi_unregister_all(void) 151 { 152 int i; 153 154 for (i = 0; i < ARRAY_SIZE(devices); ++i) 155 platform_device_unregister(devices[i]); 156 platform_driver_unregister(&snd_virmidi_driver); 157 } 158 159 static int __init alsa_card_virmidi_init(void) 160 { 161 int i, cards, err; 162 163 if ((err = platform_driver_register(&snd_virmidi_driver)) < 0) 164 return err; 165 166 cards = 0; 167 for (i = 0; i < SNDRV_CARDS; i++) { 168 struct platform_device *device; 169 if (! enable[i]) 170 continue; 171 device = platform_device_register_simple(SND_VIRMIDI_DRIVER, 172 i, NULL, 0); 173 if (IS_ERR(device)) 174 continue; 175 if (!platform_get_drvdata(device)) { 176 platform_device_unregister(device); 177 continue; 178 } 179 devices[i] = device; 180 cards++; 181 } 182 if (!cards) { 183 #ifdef MODULE 184 printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy\n"); 185 #endif 186 snd_virmidi_unregister_all(); 187 return -ENODEV; 188 } 189 return 0; 190 } 191 192 static void __exit alsa_card_virmidi_exit(void) 193 { 194 snd_virmidi_unregister_all(); 195 } 196 197 module_init(alsa_card_virmidi_init) 198 module_exit(alsa_card_virmidi_exit) 199