sound/drivers/virmidi.c

   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         return 0;
 136 }
 137
 138 #define SND_VIRMIDI_DRIVER      "snd_virmidi"
 139
 140 static struct platform_driver snd_virmidi_driver = {
 141         .probe          = snd_virmidi_probe,
 142         .remove         = snd_virmidi_remove,
 143         .driver         = {
 144                 .name   = SND_VIRMIDI_DRIVER,
 145                 .owner  = THIS_MODULE,
 146         },
 147 };
 148
 149 static void snd_virmidi_unregister_all(void)
 150 {
 151         int i;
 152
 153         for (i = 0; i < ARRAY_SIZE(devices); ++i)
 154                 platform_device_unregister(devices[i]);
 155         platform_driver_unregister(&snd_virmidi_driver);
 156 }
 157
 158 static int __init alsa_card_virmidi_init(void)
 159 {
 160         int i, cards, err;
 161
 162         if ((err = platform_driver_register(&snd_virmidi_driver)) < 0)
 163                 return err;
 164
 165         cards = 0;
 166         for (i = 0; i < SNDRV_CARDS; i++) {
 167                 struct platform_device *device;
 168                 if (! enable[i])
 169                         continue;
 170                 device = platform_device_register_simple(SND_VIRMIDI_DRIVER,
 171                                                          i, NULL, 0);
 172                 if (IS_ERR(device))
 173                         continue;
 174                 if (!platform_get_drvdata(device)) {
 175                         platform_device_unregister(device);
 176                         continue;
 177                 }
 178                 devices[i] = device;
 179                 cards++;
 180         }
 181         if (!cards) {
 182 #ifdef MODULE
 183                 printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy\n");
 184 #endif
 185                 snd_virmidi_unregister_all();
 186                 return -ENODEV;
 187         }
 188         return 0;
 189 }
 190
 191 static void __exit alsa_card_virmidi_exit(void)
 192 {
 193         snd_virmidi_unregister_all();
 194 }
 195
 196 module_init(alsa_card_virmidi_init)
 197 module_exit(alsa_card_virmidi_exit)