cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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virmidi.c (4569B)

      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
     43MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
     44MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices");
     45MODULE_LICENSE("GPL");
     46
     47#define MAX_MIDI_DEVICES	4
     48
     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		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, 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 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
    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)