Revision cbd6ac3837cdc62f3078b53b92ad6ee59329e4dd authored by Linus Torvalds on 19 May 2023, 18:25:17 UTC, committed by Linus Torvalds on 19 May 2023, 18:25:17 UTC
Pull documentation fixes from Jonathan Corbet: "Four straightforward documentation fixes" * tag 'docs-6.4-fixes' of git://git.lwn.net/linux: Documentation/filesystems: ramfs-rootfs-initramfs: use :Author: Documentation/filesystems: sharedsubtree: add section headings docs: quickly-build-trimmed-linux: various small fixes and improvements Documentation: use capitalization for chapters and acronyms
sound_oss.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Advanced Linux Sound Architecture
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/init.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <linux/sound.h>
#include <linux/mutex.h>
#define SNDRV_OSS_MINORS 256
static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
static DEFINE_MUTEX(sound_oss_mutex);
/* NOTE: This function increments the refcount of the associated card like
* snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
*/
void *snd_lookup_oss_minor_data(unsigned int minor, int type)
{
struct snd_minor *mreg;
void *private_data;
if (minor >= ARRAY_SIZE(snd_oss_minors))
return NULL;
mutex_lock(&sound_oss_mutex);
mreg = snd_oss_minors[minor];
if (mreg && mreg->type == type) {
private_data = mreg->private_data;
if (private_data && mreg->card_ptr)
get_device(&mreg->card_ptr->card_dev);
} else
private_data = NULL;
mutex_unlock(&sound_oss_mutex);
return private_data;
}
EXPORT_SYMBOL(snd_lookup_oss_minor_data);
static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
{
int minor;
switch (type) {
case SNDRV_OSS_DEVICE_TYPE_MIXER:
if (snd_BUG_ON(!card || dev < 0 || dev > 1))
return -EINVAL;
minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
break;
case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
minor = SNDRV_MINOR_OSS_SEQUENCER;
break;
case SNDRV_OSS_DEVICE_TYPE_MUSIC:
minor = SNDRV_MINOR_OSS_MUSIC;
break;
case SNDRV_OSS_DEVICE_TYPE_PCM:
if (snd_BUG_ON(!card || dev < 0 || dev > 1))
return -EINVAL;
minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
break;
case SNDRV_OSS_DEVICE_TYPE_MIDI:
if (snd_BUG_ON(!card || dev < 0 || dev > 1))
return -EINVAL;
minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
break;
case SNDRV_OSS_DEVICE_TYPE_DMFM:
minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
break;
case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
minor = SNDRV_MINOR_OSS_SNDSTAT;
break;
default:
return -EINVAL;
}
if (minor < 0 || minor >= SNDRV_OSS_MINORS)
return -EINVAL;
return minor;
}
int snd_register_oss_device(int type, struct snd_card *card, int dev,
const struct file_operations *f_ops, void *private_data)
{
int minor = snd_oss_kernel_minor(type, card, dev);
int minor_unit;
struct snd_minor *preg;
int cidx = SNDRV_MINOR_OSS_CARD(minor);
int track2 = -1;
int register1 = -1, register2 = -1;
struct device *carddev = snd_card_get_device_link(card);
if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
return 0; /* ignore silently */
if (minor < 0)
return minor;
preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
if (preg == NULL)
return -ENOMEM;
preg->type = type;
preg->card = card ? card->number : -1;
preg->device = dev;
preg->f_ops = f_ops;
preg->private_data = private_data;
preg->card_ptr = card;
mutex_lock(&sound_oss_mutex);
snd_oss_minors[minor] = preg;
minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
switch (minor_unit) {
case SNDRV_MINOR_OSS_PCM:
track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
break;
case SNDRV_MINOR_OSS_MIDI:
track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
break;
case SNDRV_MINOR_OSS_MIDI1:
track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
break;
}
register1 = register_sound_special_device(f_ops, minor, carddev);
if (register1 != minor)
goto __end;
if (track2 >= 0) {
register2 = register_sound_special_device(f_ops, track2,
carddev);
if (register2 != track2)
goto __end;
snd_oss_minors[track2] = preg;
}
mutex_unlock(&sound_oss_mutex);
return 0;
__end:
if (register2 >= 0)
unregister_sound_special(register2);
if (register1 >= 0)
unregister_sound_special(register1);
snd_oss_minors[minor] = NULL;
mutex_unlock(&sound_oss_mutex);
kfree(preg);
return -EBUSY;
}
EXPORT_SYMBOL(snd_register_oss_device);
int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
{
int minor = snd_oss_kernel_minor(type, card, dev);
int cidx = SNDRV_MINOR_OSS_CARD(minor);
int track2 = -1;
struct snd_minor *mptr;
if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
return 0;
if (minor < 0)
return minor;
mutex_lock(&sound_oss_mutex);
mptr = snd_oss_minors[minor];
if (mptr == NULL) {
mutex_unlock(&sound_oss_mutex);
return -ENOENT;
}
switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
case SNDRV_MINOR_OSS_PCM:
track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
break;
case SNDRV_MINOR_OSS_MIDI:
track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
break;
case SNDRV_MINOR_OSS_MIDI1:
track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
break;
}
if (track2 >= 0)
snd_oss_minors[track2] = NULL;
snd_oss_minors[minor] = NULL;
mutex_unlock(&sound_oss_mutex);
/* call unregister_sound_special() outside sound_oss_mutex;
* otherwise may deadlock, as it can trigger the release of a card
*/
unregister_sound_special(minor);
if (track2 >= 0)
unregister_sound_special(track2);
kfree(mptr);
return 0;
}
EXPORT_SYMBOL(snd_unregister_oss_device);
/*
* INFO PART
*/
#ifdef CONFIG_SND_PROC_FS
static const char *snd_oss_device_type_name(int type)
{
switch (type) {
case SNDRV_OSS_DEVICE_TYPE_MIXER:
return "mixer";
case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
case SNDRV_OSS_DEVICE_TYPE_MUSIC:
return "sequencer";
case SNDRV_OSS_DEVICE_TYPE_PCM:
return "digital audio";
case SNDRV_OSS_DEVICE_TYPE_MIDI:
return "raw midi";
case SNDRV_OSS_DEVICE_TYPE_DMFM:
return "hardware dependent";
default:
return "?";
}
}
static void snd_minor_info_oss_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int minor;
struct snd_minor *mptr;
mutex_lock(&sound_oss_mutex);
for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
mptr = snd_oss_minors[minor];
if (!mptr)
continue;
if (mptr->card >= 0)
snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
mptr->card, mptr->device,
snd_oss_device_type_name(mptr->type));
else
snd_iprintf(buffer, "%3i: : %s\n", minor,
snd_oss_device_type_name(mptr->type));
}
mutex_unlock(&sound_oss_mutex);
}
int __init snd_minor_info_oss_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
if (!entry)
return -ENOMEM;
entry->c.text.read = snd_minor_info_oss_read;
return snd_info_register(entry); /* freed in error path */
}
#endif /* CONFIG_SND_PROC_FS */
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