sound/core/sound_oss.c

   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
  19 static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
  20 static 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  */
  25 void *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 }
  43 EXPORT_SYMBOL(snd_lookup_oss_minor_data);
  44
  45 static 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
  85 int 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 }
 146 EXPORT_SYMBOL(snd_register_oss_device);
 147
 148 int 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         switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
 166         case SNDRV_MINOR_OSS_PCM:
 167                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
 168                 break;
 169         case SNDRV_MINOR_OSS_MIDI:
 170                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
 171                 break;
 172         case SNDRV_MINOR_OSS_MIDI1:
 173                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
 174                 break;
 175         }
 176         if (track2 >= 0)
 177                 snd_oss_minors[track2] = NULL;
 178         snd_oss_minors[minor] = NULL;
 179         mutex_unlock(&sound_oss_mutex);
 180
 181         /* call unregister_sound_special() outside sound_oss_mutex;
 182          * otherwise may deadlock, as it can trigger the release of a card
 183          */
 184         unregister_sound_special(minor);
 185         if (track2 >= 0)
 186                 unregister_sound_special(track2);
 187
 188         kfree(mptr);
 189         return 0;
 190 }
 191 EXPORT_SYMBOL(snd_unregister_oss_device);
 192
 193 /*
 194  *  INFO PART
 195  */
 196
 197 #ifdef CONFIG_SND_PROC_FS
 198 static const char *snd_oss_device_type_name(int type)
 199 {
 200         switch (type) {
 201         case SNDRV_OSS_DEVICE_TYPE_MIXER:
 202                 return "mixer";
 203         case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
 204         case SNDRV_OSS_DEVICE_TYPE_MUSIC:
 205                 return "sequencer";
 206         case SNDRV_OSS_DEVICE_TYPE_PCM:
 207                 return "digital audio";
 208         case SNDRV_OSS_DEVICE_TYPE_MIDI:
 209                 return "raw midi";
 210         case SNDRV_OSS_DEVICE_TYPE_DMFM:
 211                 return "hardware dependent";
 212         default:
 213                 return "?";
 214         }
 215 }
 216
 217 static void snd_minor_info_oss_read(struct snd_info_entry *entry,
 218                                     struct snd_info_buffer *buffer)
 219 {
 220         int minor;
 221         struct snd_minor *mptr;
 222
 223         mutex_lock(&sound_oss_mutex);
 224         for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
 225                 mptr = snd_oss_minors[minor];
 226                 if (!mptr)
 227                         continue;
 228                 if (mptr->card >= 0)
 229                         snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
 230                                     mptr->card, mptr->device,
 231                                     snd_oss_device_type_name(mptr->type));
 232                 else
 233                         snd_iprintf(buffer, "%3i:       : %s\n", minor,
 234                                     snd_oss_device_type_name(mptr->type));
 235         }
 236         mutex_unlock(&sound_oss_mutex);
 237 }
 238
 239
 240 int __init snd_minor_info_oss_init(void)
 241 {
 242         struct snd_info_entry *entry;
 243
 244         entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
 245         if (!entry)
 246                 return -ENOMEM;
 247         entry->c.text.read = snd_minor_info_oss_read;
 248         return snd_info_register(entry); /* freed in error path */
 249 }
 250 #endif /* CONFIG_SND_PROC_FS */