1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Dummy soundcard for virtual rawmidi devices
5 * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>
9 * VIRTUAL RAW MIDI DEVICE CARDS
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.
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.
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
27 * - Run application using a midi device (eg. /dev/snd/midiC1D0)
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>
40 /* hack: OSS defines midi_devs, so undefine it (versioned symbols) */
43 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
44 MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices");
45 MODULE_LICENSE("GPL");
47 #define MAX_MIDI_DEVICES 4
49 static int index
[SNDRV_CARDS
] = SNDRV_DEFAULT_IDX
; /* Index 0-MAX */
50 static char *id
[SNDRV_CARDS
] = SNDRV_DEFAULT_STR
; /* ID for this card */
51 static bool enable
[SNDRV_CARDS
] = {1, [1 ... (SNDRV_CARDS
- 1)] = 0};
52 static int midi_devs
[SNDRV_CARDS
] = {[0 ... (SNDRV_CARDS
- 1)] = 4};
54 module_param_array(index
, int, NULL
, 0444);
55 MODULE_PARM_DESC(index
, "Index value for virmidi soundcard.");
56 module_param_array(id
, charp
, NULL
, 0444);
57 MODULE_PARM_DESC(id
, "ID string for virmidi soundcard.");
58 module_param_array(enable
, bool, NULL
, 0444);
59 MODULE_PARM_DESC(enable
, "Enable this soundcard.");
60 module_param_array(midi_devs
, int, NULL
, 0444);
61 MODULE_PARM_DESC(midi_devs
, "MIDI devices # (1-4)");
63 struct snd_card_virmidi
{
64 struct snd_card
*card
;
65 struct snd_rawmidi
*midi
[MAX_MIDI_DEVICES
];
68 static struct platform_device
*devices
[SNDRV_CARDS
];
71 static int snd_virmidi_probe(struct platform_device
*devptr
)
73 struct snd_card
*card
;
74 struct snd_card_virmidi
*vmidi
;
78 err
= snd_devm_card_new(&devptr
->dev
, index
[dev
], id
[dev
], THIS_MODULE
,
79 sizeof(struct snd_card_virmidi
), &card
);
82 vmidi
= card
->private_data
;
85 if (midi_devs
[dev
] > MAX_MIDI_DEVICES
) {
86 snd_printk(KERN_WARNING
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
;
91 for (idx
= 0; idx
< midi_devs
[dev
]; idx
++) {
92 struct snd_rawmidi
*rmidi
;
93 struct snd_virmidi_dev
*rdev
;
95 err
= snd_virmidi_new(card
, idx
, &rmidi
);
98 rdev
= rmidi
->private_data
;
99 vmidi
->midi
[idx
] = rmidi
;
100 strcpy(rmidi
->name
, "Virtual Raw MIDI");
101 rdev
->seq_mode
= SNDRV_VIRMIDI_SEQ_DISPATCH
;
104 strcpy(card
->driver
, "VirMIDI");
105 strcpy(card
->shortname
, "VirMIDI");
106 sprintf(card
->longname
, "Virtual MIDI Card %i", dev
+ 1);
108 err
= snd_card_register(card
);
112 platform_set_drvdata(devptr
, card
);
116 #define SND_VIRMIDI_DRIVER "snd_virmidi"
118 static struct platform_driver snd_virmidi_driver
= {
119 .probe
= snd_virmidi_probe
,
121 .name
= SND_VIRMIDI_DRIVER
,
125 static void snd_virmidi_unregister_all(void)
129 for (i
= 0; i
< ARRAY_SIZE(devices
); ++i
)
130 platform_device_unregister(devices
[i
]);
131 platform_driver_unregister(&snd_virmidi_driver
);
134 static int __init
alsa_card_virmidi_init(void)
138 err
= platform_driver_register(&snd_virmidi_driver
);
143 for (i
= 0; i
< SNDRV_CARDS
; i
++) {
144 struct platform_device
*device
;
148 device
= platform_device_register_simple(SND_VIRMIDI_DRIVER
,
152 if (!platform_get_drvdata(device
)) {
153 platform_device_unregister(device
);
161 printk(KERN_ERR
"Card-VirMIDI soundcard not found or device busy\n");
163 snd_virmidi_unregister_all();
169 static void __exit
alsa_card_virmidi_exit(void)
171 snd_virmidi_unregister_all();
174 module_init(alsa_card_virmidi_init
)
175 module_exit(alsa_card_virmidi_exit
)