linux/sound/drivers/virmidi.c
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   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 __devinit 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
 132static int __devexit 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
 141static struct platform_driver snd_virmidi_driver = {
 142        .probe          = snd_virmidi_probe,
 143        .remove         = __devexit_p(snd_virmidi_remove),
 144        .driver         = {
 145                .name   = SND_VIRMIDI_DRIVER,
 146                .owner  = THIS_MODULE,
 147        },
 148};
 149
 150static 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
 159static 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
 192static void __exit alsa_card_virmidi_exit(void)
 193{
 194        snd_virmidi_unregister_all();
 195}
 196
 197module_init(alsa_card_virmidi_init)
 198module_exit(alsa_card_virmidi_exit)
 199
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