b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * Dummy soundcard for virtual rawmidi devices |
| 4 | * |
| 5 | * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de> |
| 6 | */ |
| 7 | |
| 8 | /* |
| 9 | * VIRTUAL RAW MIDI DEVICE CARDS |
| 10 | * |
| 11 | * This dummy card contains up to 4 virtual rawmidi devices. |
| 12 | * They are not real rawmidi devices but just associated with sequencer |
| 13 | * clients, so that any input/output sources can be connected as a raw |
| 14 | * 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=2 |
| 20 | * Then, sequencer clients 72:0 to 75:0 will be created, which are |
| 21 | * 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 -> 72:0 |
| 25 | * % aconnect 72:0 65:0 # output device redirection 72:0 -> 65:0 |
| 26 | * |
| 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_devs |
| 42 | |
| 43 | MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); |
| 44 | MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices"); |
| 45 | MODULE_LICENSE("GPL"); |
| 46 | MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual rawmidi device}}"); |
| 47 | |
| 48 | #define MAX_MIDI_DEVICES 4 |
| 49 | |
| 50 | static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ |
| 51 | static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ |
| 52 | static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; |
| 53 | static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 4}; |
| 54 | |
| 55 | module_param_array(index, int, NULL, 0444); |
| 56 | MODULE_PARM_DESC(index, "Index value for virmidi soundcard."); |
| 57 | module_param_array(id, charp, NULL, 0444); |
| 58 | MODULE_PARM_DESC(id, "ID string for virmidi soundcard."); |
| 59 | module_param_array(enable, bool, NULL, 0444); |
| 60 | MODULE_PARM_DESC(enable, "Enable this soundcard."); |
| 61 | module_param_array(midi_devs, int, NULL, 0444); |
| 62 | MODULE_PARM_DESC(midi_devs, "MIDI devices # (1-4)"); |
| 63 | |
| 64 | struct snd_card_virmidi { |
| 65 | struct snd_card *card; |
| 66 | struct snd_rawmidi *midi[MAX_MIDI_DEVICES]; |
| 67 | }; |
| 68 | |
| 69 | static struct platform_device *devices[SNDRV_CARDS]; |
| 70 | |
| 71 | |
| 72 | static int snd_virmidi_probe(struct platform_device *devptr) |
| 73 | { |
| 74 | struct snd_card *card; |
| 75 | struct snd_card_virmidi *vmidi; |
| 76 | int idx, err; |
| 77 | int dev = devptr->id; |
| 78 | |
| 79 | err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE, |
| 80 | sizeof(struct snd_card_virmidi), &card); |
| 81 | if (err < 0) |
| 82 | return err; |
| 83 | vmidi = card->private_data; |
| 84 | vmidi->card = card; |
| 85 | |
| 86 | if (midi_devs[dev] > MAX_MIDI_DEVICES) { |
| 87 | snd_printk(KERN_WARNING |
| 88 | "too much midi devices for virmidi %d: force to use %d\n", |
| 89 | dev, MAX_MIDI_DEVICES); |
| 90 | midi_devs[dev] = MAX_MIDI_DEVICES; |
| 91 | } |
| 92 | for (idx = 0; idx < midi_devs[dev]; idx++) { |
| 93 | struct snd_rawmidi *rmidi; |
| 94 | struct snd_virmidi_dev *rdev; |
| 95 | |
| 96 | err = snd_virmidi_new(card, idx, &rmidi); |
| 97 | if (err < 0) |
| 98 | goto __nodev; |
| 99 | rdev = rmidi->private_data; |
| 100 | vmidi->midi[idx] = rmidi; |
| 101 | strcpy(rmidi->name, "Virtual Raw MIDI"); |
| 102 | rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH; |
| 103 | } |
| 104 | |
| 105 | strcpy(card->driver, "VirMIDI"); |
| 106 | strcpy(card->shortname, "VirMIDI"); |
| 107 | sprintf(card->longname, "Virtual MIDI Card %i", dev + 1); |
| 108 | |
| 109 | err = snd_card_register(card); |
| 110 | if (!err) { |
| 111 | platform_set_drvdata(devptr, card); |
| 112 | return 0; |
| 113 | } |
| 114 | __nodev: |
| 115 | snd_card_free(card); |
| 116 | return err; |
| 117 | } |
| 118 | |
| 119 | static int snd_virmidi_remove(struct platform_device *devptr) |
| 120 | { |
| 121 | snd_card_free(platform_get_drvdata(devptr)); |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | #define SND_VIRMIDI_DRIVER "snd_virmidi" |
| 126 | |
| 127 | static struct platform_driver snd_virmidi_driver = { |
| 128 | .probe = snd_virmidi_probe, |
| 129 | .remove = snd_virmidi_remove, |
| 130 | .driver = { |
| 131 | .name = SND_VIRMIDI_DRIVER, |
| 132 | }, |
| 133 | }; |
| 134 | |
| 135 | static void snd_virmidi_unregister_all(void) |
| 136 | { |
| 137 | int i; |
| 138 | |
| 139 | for (i = 0; i < ARRAY_SIZE(devices); ++i) |
| 140 | platform_device_unregister(devices[i]); |
| 141 | platform_driver_unregister(&snd_virmidi_driver); |
| 142 | } |
| 143 | |
| 144 | static int __init alsa_card_virmidi_init(void) |
| 145 | { |
| 146 | int i, cards, err; |
| 147 | |
| 148 | err = platform_driver_register(&snd_virmidi_driver); |
| 149 | if (err < 0) |
| 150 | return err; |
| 151 | |
| 152 | cards = 0; |
| 153 | for (i = 0; i < SNDRV_CARDS; i++) { |
| 154 | struct platform_device *device; |
| 155 | |
| 156 | if (!enable[i]) |
| 157 | continue; |
| 158 | device = platform_device_register_simple(SND_VIRMIDI_DRIVER, |
| 159 | i, NULL, 0); |
| 160 | if (IS_ERR(device)) |
| 161 | continue; |
| 162 | if (!platform_get_drvdata(device)) { |
| 163 | platform_device_unregister(device); |
| 164 | continue; |
| 165 | } |
| 166 | devices[i] = device; |
| 167 | cards++; |
| 168 | } |
| 169 | if (!cards) { |
| 170 | #ifdef MODULE |
| 171 | printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy\n"); |
| 172 | #endif |
| 173 | snd_virmidi_unregister_all(); |
| 174 | return -ENODEV; |
| 175 | } |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | static void __exit alsa_card_virmidi_exit(void) |
| 180 | { |
| 181 | snd_virmidi_unregister_all(); |
| 182 | } |
| 183 | |
| 184 | module_init(alsa_card_virmidi_init) |
| 185 | module_exit(alsa_card_virmidi_exit) |