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 | |
47 | #define MAX_MIDI_DEVICES 4 |
48 | |
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}; |
53 | |
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)" ); |
62 | |
63 | struct snd_card_virmidi { |
64 | struct snd_card *card; |
65 | struct snd_rawmidi *midi[MAX_MIDI_DEVICES]; |
66 | }; |
67 | |
68 | static struct platform_device *devices[SNDRV_CARDS]; |
69 | |
70 | |
71 | static 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(parent: &devptr->dev, idx: index[dev], xid: id[dev], THIS_MODULE, |
79 | extra_size: sizeof(struct snd_card_virmidi), card_ret: &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 | 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; |
90 | } |
91 | for (idx = 0; idx < midi_devs[dev]; idx++) { |
92 | struct snd_rawmidi *rmidi; |
93 | |
94 | err = snd_virmidi_new(card, device: idx, rrmidi: &rmidi); |
95 | if (err < 0) |
96 | return err; |
97 | vmidi->midi[idx] = rmidi; |
98 | strcpy(p: rmidi->name, q: "Virtual Raw MIDI" ); |
99 | } |
100 | |
101 | strcpy(p: card->driver, q: "VirMIDI" ); |
102 | strcpy(p: card->shortname, q: "VirMIDI" ); |
103 | sprintf(buf: card->longname, fmt: "Virtual MIDI Card %i" , dev + 1); |
104 | |
105 | err = snd_card_register(card); |
106 | if (err) |
107 | return err; |
108 | |
109 | platform_set_drvdata(pdev: devptr, data: card); |
110 | return 0; |
111 | } |
112 | |
113 | #define SND_VIRMIDI_DRIVER "snd_virmidi" |
114 | |
115 | static struct platform_driver snd_virmidi_driver = { |
116 | .probe = snd_virmidi_probe, |
117 | .driver = { |
118 | .name = SND_VIRMIDI_DRIVER, |
119 | }, |
120 | }; |
121 | |
122 | static 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 | |
131 | static 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 | id: i, NULL, num: 0); |
147 | if (IS_ERR(ptr: device)) |
148 | continue; |
149 | if (!platform_get_drvdata(pdev: device)) { |
150 | platform_device_unregister(device); |
151 | continue; |
152 | } |
153 | devices[i] = device; |
154 | cards++; |
155 | } |
156 | if (!cards) { |
157 | #ifdef MODULE |
158 | printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy\n" ); |
159 | #endif |
160 | snd_virmidi_unregister_all(); |
161 | return -ENODEV; |
162 | } |
163 | return 0; |
164 | } |
165 | |
166 | static void __exit alsa_card_virmidi_exit(void) |
167 | { |
168 | snd_virmidi_unregister_all(); |
169 | } |
170 | |
171 | module_init(alsa_card_virmidi_init) |
172 | module_exit(alsa_card_virmidi_exit) |
173 | |