linux/sound/core/sound_oss.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Advanced Linux Sound Architecture
   4 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   5 */
   6
   7#include <linux/init.h>
   8#include <linux/export.h>
   9#include <linux/slab.h>
  10#include <linux/time.h>
  11#include <sound/core.h>
  12#include <sound/minors.h>
  13#include <sound/info.h>
  14#include <linux/sound.h>
  15#include <linux/mutex.h>
  16
  17#define SNDRV_OSS_MINORS 256
  18
  19static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
  20static DEFINE_MUTEX(sound_oss_mutex);
  21
  22/* NOTE: This function increments the refcount of the associated card like
  23 * snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
  24 */
  25void *snd_lookup_oss_minor_data(unsigned int minor, int type)
  26{
  27        struct snd_minor *mreg;
  28        void *private_data;
  29
  30        if (minor >= ARRAY_SIZE(snd_oss_minors))
  31                return NULL;
  32        mutex_lock(&sound_oss_mutex);
  33        mreg = snd_oss_minors[minor];
  34        if (mreg && mreg->type == type) {
  35                private_data = mreg->private_data;
  36                if (private_data && mreg->card_ptr)
  37                        get_device(&mreg->card_ptr->card_dev);
  38        } else
  39                private_data = NULL;
  40        mutex_unlock(&sound_oss_mutex);
  41        return private_data;
  42}
  43EXPORT_SYMBOL(snd_lookup_oss_minor_data);
  44
  45static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
  46{
  47        int minor;
  48
  49        switch (type) {
  50        case SNDRV_OSS_DEVICE_TYPE_MIXER:
  51                if (snd_BUG_ON(!card || dev < 0 || dev > 1))
  52                        return -EINVAL;
  53                minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
  54                break;
  55        case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
  56                minor = SNDRV_MINOR_OSS_SEQUENCER;
  57                break;
  58        case SNDRV_OSS_DEVICE_TYPE_MUSIC:
  59                minor = SNDRV_MINOR_OSS_MUSIC;
  60                break;
  61        case SNDRV_OSS_DEVICE_TYPE_PCM:
  62                if (snd_BUG_ON(!card || dev < 0 || dev > 1))
  63                        return -EINVAL;
  64                minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
  65                break;
  66        case SNDRV_OSS_DEVICE_TYPE_MIDI:
  67                if (snd_BUG_ON(!card || dev < 0 || dev > 1))
  68                        return -EINVAL;
  69                minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
  70                break;
  71        case SNDRV_OSS_DEVICE_TYPE_DMFM:
  72                minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
  73                break;
  74        case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
  75                minor = SNDRV_MINOR_OSS_SNDSTAT;
  76                break;
  77        default:
  78                return -EINVAL;
  79        }
  80        if (minor < 0 || minor >= SNDRV_OSS_MINORS)
  81                return -EINVAL;
  82        return minor;
  83}
  84
  85int snd_register_oss_device(int type, struct snd_card *card, int dev,
  86                            const struct file_operations *f_ops, void *private_data)
  87{
  88        int minor = snd_oss_kernel_minor(type, card, dev);
  89        int minor_unit;
  90        struct snd_minor *preg;
  91        int cidx = SNDRV_MINOR_OSS_CARD(minor);
  92        int track2 = -1;
  93        int register1 = -1, register2 = -1;
  94        struct device *carddev = snd_card_get_device_link(card);
  95
  96        if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
  97                return 0; /* ignore silently */
  98        if (minor < 0)
  99                return minor;
 100        preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
 101        if (preg == NULL)
 102                return -ENOMEM;
 103        preg->type = type;
 104        preg->card = card ? card->number : -1;
 105        preg->device = dev;
 106        preg->f_ops = f_ops;
 107        preg->private_data = private_data;
 108        preg->card_ptr = card;
 109        mutex_lock(&sound_oss_mutex);
 110        snd_oss_minors[minor] = preg;
 111        minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
 112        switch (minor_unit) {
 113        case SNDRV_MINOR_OSS_PCM:
 114                track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
 115                break;
 116        case SNDRV_MINOR_OSS_MIDI:
 117                track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
 118                break;
 119        case SNDRV_MINOR_OSS_MIDI1:
 120                track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
 121                break;
 122        }
 123        register1 = register_sound_special_device(f_ops, minor, carddev);
 124        if (register1 != minor)
 125                goto __end;
 126        if (track2 >= 0) {
 127                register2 = register_sound_special_device(f_ops, track2,
 128                                                          carddev);
 129                if (register2 != track2)
 130                        goto __end;
 131                snd_oss_minors[track2] = preg;
 132        }
 133        mutex_unlock(&sound_oss_mutex);
 134        return 0;
 135
 136      __end:
 137        if (register2 >= 0)
 138                unregister_sound_special(register2);
 139        if (register1 >= 0)
 140                unregister_sound_special(register1);
 141        snd_oss_minors[minor] = NULL;
 142        mutex_unlock(&sound_oss_mutex);
 143        kfree(preg);
 144        return -EBUSY;
 145}
 146EXPORT_SYMBOL(snd_register_oss_device);
 147
 148int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
 149{
 150        int minor = snd_oss_kernel_minor(type, card, dev);
 151        int cidx = SNDRV_MINOR_OSS_CARD(minor);
 152        int track2 = -1;
 153        struct snd_minor *mptr;
 154
 155        if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
 156                return 0;
 157        if (minor < 0)
 158                return minor;
 159        mutex_lock(&sound_oss_mutex);
 160        mptr = snd_oss_minors[minor];
 161        if (mptr == NULL) {
 162                mutex_unlock(&sound_oss_mutex);
 163                return -ENOENT;
 164        }
 165        unregister_sound_special(minor);
 166        switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
 167        case SNDRV_MINOR_OSS_PCM:
 168                track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
 169                break;
 170        case SNDRV_MINOR_OSS_MIDI:
 171                track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
 172                break;
 173        case SNDRV_MINOR_OSS_MIDI1:
 174                track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
 175                break;
 176        }
 177        if (track2 >= 0) {
 178                unregister_sound_special(track2);
 179                snd_oss_minors[track2] = NULL;
 180        }
 181        snd_oss_minors[minor] = NULL;
 182        mutex_unlock(&sound_oss_mutex);
 183        kfree(mptr);
 184        return 0;
 185}
 186EXPORT_SYMBOL(snd_unregister_oss_device);
 187
 188/*
 189 *  INFO PART
 190 */
 191
 192#ifdef CONFIG_SND_PROC_FS
 193static const char *snd_oss_device_type_name(int type)
 194{
 195        switch (type) {
 196        case SNDRV_OSS_DEVICE_TYPE_MIXER:
 197                return "mixer";
 198        case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
 199        case SNDRV_OSS_DEVICE_TYPE_MUSIC:
 200                return "sequencer";
 201        case SNDRV_OSS_DEVICE_TYPE_PCM:
 202                return "digital audio";
 203        case SNDRV_OSS_DEVICE_TYPE_MIDI:
 204                return "raw midi";
 205        case SNDRV_OSS_DEVICE_TYPE_DMFM:
 206                return "hardware dependent";
 207        default:
 208                return "?";
 209        }
 210}
 211
 212static void snd_minor_info_oss_read(struct snd_info_entry *entry,
 213                                    struct snd_info_buffer *buffer)
 214{
 215        int minor;
 216        struct snd_minor *mptr;
 217
 218        mutex_lock(&sound_oss_mutex);
 219        for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
 220                if (!(mptr = snd_oss_minors[minor]))
 221                        continue;
 222                if (mptr->card >= 0)
 223                        snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
 224                                    mptr->card, mptr->device,
 225                                    snd_oss_device_type_name(mptr->type));
 226                else
 227                        snd_iprintf(buffer, "%3i:       : %s\n", minor,
 228                                    snd_oss_device_type_name(mptr->type));
 229        }
 230        mutex_unlock(&sound_oss_mutex);
 231}
 232
 233
 234int __init snd_minor_info_oss_init(void)
 235{
 236        struct snd_info_entry *entry;
 237
 238        entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
 239        if (!entry)
 240                return -ENOMEM;
 241        entry->c.text.read = snd_minor_info_oss_read;
 242        return snd_info_register(entry); /* freed in error path */
 243}
 244#endif /* CONFIG_SND_PROC_FS */
 245
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