diff options
Diffstat (limited to 'sound/drivers/virmidi.c')
| -rw-r--r-- | sound/drivers/virmidi.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/sound/drivers/virmidi.c b/sound/drivers/virmidi.c new file mode 100644 index 000000000..f1fb68b15 --- /dev/null +++ b/sound/drivers/virmidi.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Dummy soundcard for virtual rawmidi devices + * + * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de> + */ + +/* + * VIRTUAL RAW MIDI DEVICE CARDS + * + * This dummy card contains up to 4 virtual rawmidi devices. + * They are not real rawmidi devices but just associated with sequencer + * clients, so that any input/output sources can be connected as a raw + * MIDI device arbitrary. + * Also, multiple access is allowed to a single rawmidi device. + * + * Typical usage is like following: + * - Load snd-virmidi module. + * # modprobe snd-virmidi index=2 + * Then, sequencer clients 72:0 to 75:0 will be created, which are + * mapped from /dev/snd/midiC1D0 to /dev/snd/midiC1D3, respectively. + * + * - Connect input/output via aconnect. + * % aconnect 64:0 72:0 # keyboard input redirection 64:0 -> 72:0 + * % aconnect 72:0 65:0 # output device redirection 72:0 -> 65:0 + * + * - Run application using a midi device (eg. /dev/snd/midiC1D0) + */ + +#include <linux/init.h> +#include <linux/wait.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/module.h> +#include <sound/core.h> +#include <sound/seq_kernel.h> +#include <sound/seq_virmidi.h> +#include <sound/initval.h> + +/* hack: OSS defines midi_devs, so undefine it (versioned symbols) */ +#undef midi_devs + +MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); +MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices"); +MODULE_LICENSE("GPL"); +MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual rawmidi device}}"); + +#define MAX_MIDI_DEVICES 4 + +static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ +static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ +static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; +static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 4}; + +module_param_array(index, int, NULL, 0444); +MODULE_PARM_DESC(index, "Index value for virmidi soundcard."); +module_param_array(id, charp, NULL, 0444); +MODULE_PARM_DESC(id, "ID string for virmidi soundcard."); +module_param_array(enable, bool, NULL, 0444); +MODULE_PARM_DESC(enable, "Enable this soundcard."); +module_param_array(midi_devs, int, NULL, 0444); +MODULE_PARM_DESC(midi_devs, "MIDI devices # (1-4)"); + +struct snd_card_virmidi { + struct snd_card *card; + struct snd_rawmidi *midi[MAX_MIDI_DEVICES]; +}; + +static struct platform_device *devices[SNDRV_CARDS]; + + +static int snd_virmidi_probe(struct platform_device *devptr) +{ + struct snd_card *card; + struct snd_card_virmidi *vmidi; + int idx, err; + int dev = devptr->id; + + err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE, + sizeof(struct snd_card_virmidi), &card); + if (err < 0) + return err; + vmidi = card->private_data; + vmidi->card = card; + + if (midi_devs[dev] > MAX_MIDI_DEVICES) { + snd_printk(KERN_WARNING + "too much midi devices for virmidi %d: force to use %d\n", + dev, MAX_MIDI_DEVICES); + midi_devs[dev] = MAX_MIDI_DEVICES; + } + for (idx = 0; idx < midi_devs[dev]; idx++) { + struct snd_rawmidi *rmidi; + struct snd_virmidi_dev *rdev; + + err = snd_virmidi_new(card, idx, &rmidi); + if (err < 0) + goto __nodev; + rdev = rmidi->private_data; + vmidi->midi[idx] = rmidi; + strcpy(rmidi->name, "Virtual Raw MIDI"); + rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH; + } + + strcpy(card->driver, "VirMIDI"); + strcpy(card->shortname, "VirMIDI"); + sprintf(card->longname, "Virtual MIDI Card %i", dev + 1); + + err = snd_card_register(card); + if (!err) { + platform_set_drvdata(devptr, card); + return 0; + } +__nodev: + snd_card_free(card); + return err; +} + +static int snd_virmidi_remove(struct platform_device *devptr) +{ + snd_card_free(platform_get_drvdata(devptr)); + return 0; +} + +#define SND_VIRMIDI_DRIVER "snd_virmidi" + +static struct platform_driver snd_virmidi_driver = { + .probe = snd_virmidi_probe, + .remove = snd_virmidi_remove, + .driver = { + .name = SND_VIRMIDI_DRIVER, + }, +}; + +static void snd_virmidi_unregister_all(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(devices); ++i) + platform_device_unregister(devices[i]); + platform_driver_unregister(&snd_virmidi_driver); +} + +static int __init alsa_card_virmidi_init(void) +{ + int i, cards, err; + + err = platform_driver_register(&snd_virmidi_driver); + if (err < 0) + return err; + + cards = 0; + for (i = 0; i < SNDRV_CARDS; i++) { + struct platform_device *device; + + if (!enable[i]) + continue; + device = platform_device_register_simple(SND_VIRMIDI_DRIVER, + i, NULL, 0); + if (IS_ERR(device)) + continue; + if (!platform_get_drvdata(device)) { + platform_device_unregister(device); + continue; + } + devices[i] = device; + cards++; + } + if (!cards) { +#ifdef MODULE + printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy\n"); +#endif + snd_virmidi_unregister_all(); + return -ENODEV; + } + return 0; +} + +static void __exit alsa_card_virmidi_exit(void) +{ + snd_virmidi_unregister_all(); +} + +module_init(alsa_card_virmidi_init) +module_exit(alsa_card_virmidi_exit) |