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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Dummy soundcard for virtual rawmidi devices4 *5 * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>6 */7 8/*9 * VIRTUAL RAW MIDI DEVICE CARDS10 *11 * This dummy card contains up to 4 virtual rawmidi devices.12 * They are not real rawmidi devices but just associated with sequencer13 * clients, so that any input/output sources can be connected as a raw14 * MIDI device arbitrary.15 * Also, multiple access is allowed to a single rawmidi device.16 *17 * Typical usage is like following:18 * - Load snd-virmidi module.19 * # modprobe snd-virmidi index=220 * Then, sequencer clients 72:0 to 75:0 will be created, which are21 * mapped from /dev/snd/midiC1D0 to /dev/snd/midiC1D3, respectively.22 *23 * - Connect input/output via aconnect.24 * % aconnect 64:0 72:0 # keyboard input redirection 64:0 -> 72:025 * % aconnect 72:0 65:0 # output device redirection 72:0 -> 65:026 *27 * - Run application using a midi device (eg. /dev/snd/midiC1D0)28 */29 30#include <linux/init.h>31#include <linux/wait.h>32#include <linux/err.h>33#include <linux/platform_device.h>34#include <linux/module.h>35#include <sound/core.h>36#include <sound/seq_kernel.h>37#include <sound/seq_virmidi.h>38#include <sound/initval.h>39 40/* hack: OSS defines midi_devs, so undefine it (versioned symbols) */41#undef midi_devs42 43MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");44MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices");45MODULE_LICENSE("GPL");46 47#define MAX_MIDI_DEVICES 448 49static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */50static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */51static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};52static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 4};53 54module_param_array(index, int, NULL, 0444);55MODULE_PARM_DESC(index, "Index value for virmidi soundcard.");56module_param_array(id, charp, NULL, 0444);57MODULE_PARM_DESC(id, "ID string for virmidi soundcard.");58module_param_array(enable, bool, NULL, 0444);59MODULE_PARM_DESC(enable, "Enable this soundcard.");60module_param_array(midi_devs, int, NULL, 0444);61MODULE_PARM_DESC(midi_devs, "MIDI devices # (1-4)");62 63struct snd_card_virmidi {64 struct snd_card *card;65 struct snd_rawmidi *midi[MAX_MIDI_DEVICES];66};67 68static struct platform_device *devices[SNDRV_CARDS];69 70 71static int snd_virmidi_probe(struct platform_device *devptr)72{73 struct snd_card *card;74 struct snd_card_virmidi *vmidi;75 int idx, err;76 int dev = devptr->id;77 78 err = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,79 sizeof(struct snd_card_virmidi), &card);80 if (err < 0)81 return err;82 vmidi = card->private_data;83 vmidi->card = card;84 85 if (midi_devs[dev] > MAX_MIDI_DEVICES) {86 dev_warn(&devptr->dev,87 "too much midi devices for virmidi %d: force to use %d\n",88 dev, MAX_MIDI_DEVICES);89 midi_devs[dev] = MAX_MIDI_DEVICES;90 }91 for (idx = 0; idx < midi_devs[dev]; idx++) {92 struct snd_rawmidi *rmidi;93 94 err = snd_virmidi_new(card, idx, &rmidi);95 if (err < 0)96 return err;97 vmidi->midi[idx] = rmidi;98 strcpy(rmidi->name, "Virtual Raw MIDI");99 }100 101 strcpy(card->driver, "VirMIDI");102 strcpy(card->shortname, "VirMIDI");103 sprintf(card->longname, "Virtual MIDI Card %i", dev + 1);104 105 err = snd_card_register(card);106 if (err)107 return err;108 109 platform_set_drvdata(devptr, card);110 return 0;111}112 113#define SND_VIRMIDI_DRIVER "snd_virmidi"114 115static struct platform_driver snd_virmidi_driver = {116 .probe = snd_virmidi_probe,117 .driver = {118 .name = SND_VIRMIDI_DRIVER,119 },120};121 122static void snd_virmidi_unregister_all(void)123{124 int i;125 126 for (i = 0; i < ARRAY_SIZE(devices); ++i)127 platform_device_unregister(devices[i]);128 platform_driver_unregister(&snd_virmidi_driver);129}130 131static int __init alsa_card_virmidi_init(void)132{133 int i, cards, err;134 135 err = platform_driver_register(&snd_virmidi_driver);136 if (err < 0)137 return err;138 139 cards = 0;140 for (i = 0; i < SNDRV_CARDS; i++) {141 struct platform_device *device;142 143 if (!enable[i])144 continue;145 device = platform_device_register_simple(SND_VIRMIDI_DRIVER,146 i, NULL, 0);147 if (IS_ERR(device))148 continue;149 if (!platform_get_drvdata(device)) {150 platform_device_unregister(device);151 continue;152 }153 devices[i] = device;154 cards++;155 }156 if (!cards) {157#ifdef MODULE158 pr_err("Card-VirMIDI soundcard not found or device busy\n");159#endif160 snd_virmidi_unregister_all();161 return -ENODEV;162 }163 return 0;164}165 166static void __exit alsa_card_virmidi_exit(void)167{168 snd_virmidi_unregister_all();169}170 171module_init(alsa_card_virmidi_init)172module_exit(alsa_card_virmidi_exit)173