LXR linux/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
  57MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
  58MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices");
  59MODULE_LICENSE("GPL");
  60MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual rawmidi device}}");
  61
  62#define MAX_MIDI_DEVICES        4
  63
  64static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  65static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  66static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  67static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 4};
  68
  69module_param_array(index, int, NULL, 0444);
  70MODULE_PARM_DESC(index, "Index value for virmidi soundcard.");
  71module_param_array(id, charp, NULL, 0444);
  72MODULE_PARM_DESC(id, "ID string for virmidi soundcard.");
  73module_param_array(enable, bool, NULL, 0444);
  74MODULE_PARM_DESC(enable, "Enable this soundcard.");
  75module_param_array(midi_devs, int, NULL, 0444);
  76MODULE_PARM_DESC(midi_devs, "MIDI devices # (1-4)");
  77
  78struct snd_card_virmidi {
  79        struct snd_card *card;
  80        struct snd_rawmidi *midi[MAX_MIDI_DEVICES];
  81};
  82
  83static struct platform_device *devices[SNDRV_CARDS];
  84
  85
  86static 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_new(&devptr->dev, 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: force to use %d\n",
 103                           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
 110                err = snd_virmidi_new(card, idx, &rmidi);
 111                if (err < 0)
 112                        goto __nodev;
 113                rdev = rmidi->private_data;
 114                vmidi->midi[idx] = rmidi;
 115                strcpy(rmidi->name, "Virtual Raw MIDI");
 116                rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 117        }
 118
 119        strcpy(card->driver, "VirMIDI");
 120        strcpy(card->shortname, "VirMIDI");
 121        sprintf(card->longname, "Virtual MIDI Card %i", dev + 1);
 122
 123        err = snd_card_register(card);
 124        if (!err) {
 125                platform_set_drvdata(devptr, card);
 126                return 0;
 127        }
 128__nodev:
 129        snd_card_free(card);
 130        return err;
 131}
 132
 133static int snd_virmidi_remove(struct platform_device *devptr)
 134{
 135        snd_card_free(platform_get_drvdata(devptr));
 136        return 0;
 137}
 138
 139#define SND_VIRMIDI_DRIVER      "snd_virmidi"
 140
 141static struct platform_driver snd_virmidi_driver = {
 142        .probe          = snd_virmidi_probe,
 143        .remove         = snd_virmidi_remove,
 144        .driver         = {
 145                .name   = SND_VIRMIDI_DRIVER,
 146        },
 147};
 148
 149static 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
 158static int __init alsa_card_virmidi_init(void)
 159{
 160        int i, cards, err;
 161
 162        err = platform_driver_register(&snd_virmidi_driver);
 163        if (err < 0)
 164                return err;
 165
 166        cards = 0;
 167        for (i = 0; i < SNDRV_CARDS; i++) {
 168                struct platform_device *device;
 169
 170                if (!enable[i])
 171                        continue;
 172                device = platform_device_register_simple(SND_VIRMIDI_DRIVER,
 173                                                         i, NULL, 0);
 174                if (IS_ERR(device))
 175                        continue;
 176                if (!platform_get_drvdata(device)) {
 177                        platform_device_unregister(device);
 178                        continue;
 179                }
 180                devices[i] = device;
 181                cards++;
 182        }
 183        if (!cards) {
 184#ifdef MODULE
 185                printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy\n");
 186#endif
 187                snd_virmidi_unregister_all();
 188                return -ENODEV;
 189        }
 190        return 0;
 191}
 192
 193static void __exit alsa_card_virmidi_exit(void)
 194{
 195        snd_virmidi_unregister_all();
 196}
 197
 198module_init(alsa_card_virmidi_init)
 199module_exit(alsa_card_virmidi_exit)
 200