sound/core/sound_oss.c - third_party/kernel - Git at Google

 // 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 */
	// 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 */