sound/core/hwdep.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Hardware dependent layer
  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
  */

 #include <linux/major.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
 #include <linux/sched/signal.h>
 #include <sound/core.h>
 #include <sound/control.h>
 #include <sound/minors.h>
 #include <sound/hwdep.h>
 #include <sound/info.h>

 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
 MODULE_DESCRIPTION("Hardware dependent layer");
 MODULE_LICENSE("GPL");

 static LIST_HEAD(snd_hwdep_devices);
 static DEFINE_MUTEX(register_mutex);

 static int snd_hwdep_dev_free(struct snd_device *device);
 static int snd_hwdep_dev_register(struct snd_device *device);
 static int snd_hwdep_dev_disconnect(struct snd_device *device);


 static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
 {
 	struct snd_hwdep *hwdep;

 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
 		if (hwdep->card == card && hwdep->device == device)
 			return hwdep;
 	return NULL;
 }

 static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
 {
 	struct snd_hwdep *hw = file->private_data;
 	if (hw->ops.llseek)
 		return hw->ops.llseek(hw, file, offset, orig);
 	return -ENXIO;
 }

 static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
 			      size_t count, loff_t *offset)
 {
 	struct snd_hwdep *hw = file->private_data;
 	if (hw->ops.read)
 		return hw->ops.read(hw, buf, count, offset);
 	return -ENXIO;
 }

 static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
 			       size_t count, loff_t *offset)
 {
 	struct snd_hwdep *hw = file->private_data;
 	if (hw->ops.write)
 		return hw->ops.write(hw, buf, count, offset);
 	return -ENXIO;
 }

 static int snd_hwdep_open(struct inode *inode, struct file * file)
 {
 	int major = imajor(inode);
 	struct snd_hwdep *hw;
 	int err;
 	wait_queue_entry_t wait;

 	if (major == snd_major) {
 		hw = snd_lookup_minor_data(iminor(inode),
 					   SNDRV_DEVICE_TYPE_HWDEP);
 #ifdef CONFIG_SND_OSSEMUL
 	} else if (major == SOUND_MAJOR) {
 		hw = snd_lookup_oss_minor_data(iminor(inode),
 					       SNDRV_OSS_DEVICE_TYPE_DMFM);
 #endif
 	} else
 		return -ENXIO;
 	if (hw == NULL)
 		return -ENODEV;

 	if (!try_module_get(hw->card->module)) {
 		snd_card_unref(hw->card);
 		return -EFAULT;
 	}

 	init_waitqueue_entry(&wait, current);
 	add_wait_queue(&hw->open_wait, &wait);
 	mutex_lock(&hw->open_mutex);
 	while (1) {
 		if (hw->exclusive && hw->used > 0) {
 			err = -EBUSY;
 			break;
 		}
 		if (!hw->ops.open) {
 			err = 0;
 			break;
 		}
 		err = hw->ops.open(hw, file);
 		if (err >= 0)
 			break;
 		if (err == -EAGAIN) {
 			if (file->f_flags & O_NONBLOCK) {
 				err = -EBUSY;
 				break;
 			}
 		} else
 			break;
 		set_current_state(TASK_INTERRUPTIBLE);
 		mutex_unlock(&hw->open_mutex);
 		schedule();
 		mutex_lock(&hw->open_mutex);
 		if (hw->card->shutdown) {
 			err = -ENODEV;
 			break;
 		}
 		if (signal_pending(current)) {
 			err = -ERESTARTSYS;
 			break;
 		}
 	}
 	remove_wait_queue(&hw->open_wait, &wait);
 	if (err >= 0) {
 		err = snd_card_file_add(hw->card, file);
 		if (err >= 0) {
 			file->private_data = hw;
 			hw->used++;
 		} else {
 			if (hw->ops.release)
 				hw->ops.release(hw, file);
 		}
 	}
 	mutex_unlock(&hw->open_mutex);
 	if (err < 0)
 		module_put(hw->card->module);
 	snd_card_unref(hw->card);
 	return err;
 }

 static int snd_hwdep_release(struct inode *inode, struct file * file)
 {
 	int err = 0;
 	struct snd_hwdep *hw = file->private_data;
 	struct module *mod = hw->card->module;

 	mutex_lock(&hw->open_mutex);
 	if (hw->ops.release)
 		err = hw->ops.release(hw, file);
 	if (hw->used > 0)
 		hw->used--;
 	mutex_unlock(&hw->open_mutex);
 	wake_up(&hw->open_wait);

 	snd_card_file_remove(hw->card, file);
 	module_put(mod);
 	return err;
 }

 static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
 {
 	struct snd_hwdep *hw = file->private_data;
 	if (hw->ops.poll)
 		return hw->ops.poll(hw, file, wait);
 	return 0;
 }

 static int snd_hwdep_info(struct snd_hwdep *hw,
 			  struct snd_hwdep_info __user *_info)
 {
 	struct snd_hwdep_info info;

 	memset(&info, 0, sizeof(info));
 	info.card = hw->card->number;
 	strlcpy(info.id, hw->id, sizeof(info.id));
 	strlcpy(info.name, hw->name, sizeof(info.name));
 	info.iface = hw->iface;
 	if (copy_to_user(_info, &info, sizeof(info)))
 		return -EFAULT;
 	return 0;
 }

 static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
 				struct snd_hwdep_dsp_status __user *_info)
 {
 	struct snd_hwdep_dsp_status info;
 	int err;

 	if (! hw->ops.dsp_status)
 		return -ENXIO;
 	memset(&info, 0, sizeof(info));
 	info.dsp_loaded = hw->dsp_loaded;
 	if ((err = hw->ops.dsp_status(hw, &info)) < 0)
 		return err;
 	if (copy_to_user(_info, &info, sizeof(info)))
 		return -EFAULT;
 	return 0;
 }

 static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
 			      struct snd_hwdep_dsp_image __user *_info)
 {
 	struct snd_hwdep_dsp_image info;
 	int err;

 	if (! hw->ops.dsp_load)
 		return -ENXIO;
 	memset(&info, 0, sizeof(info));
 	if (copy_from_user(&info, _info, sizeof(info)))
 		return -EFAULT;
 	if (info.index >= 32)
 		return -EINVAL;
 	/* check whether the dsp was already loaded */
 	if (hw->dsp_loaded & (1 << info.index))
 		return -EBUSY;
 	err = hw->ops.dsp_load(hw, &info);
 	if (err < 0)
 		return err;
 	hw->dsp_loaded |= (1 << info.index);
 	return 0;
 }

 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
 			    unsigned long arg)
 {
 	struct snd_hwdep *hw = file->private_data;
 	void __user *argp = (void __user *)arg;
 	switch (cmd) {
 	case SNDRV_HWDEP_IOCTL_PVERSION:
 		return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
 	case SNDRV_HWDEP_IOCTL_INFO:
 		return snd_hwdep_info(hw, argp);
 	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
 		return snd_hwdep_dsp_status(hw, argp);
 	case SNDRV_HWDEP_IOCTL_DSP_LOAD:
 		return snd_hwdep_dsp_load(hw, argp);
 	}
 	if (hw->ops.ioctl)
 		return hw->ops.ioctl(hw, file, cmd, arg);
 	return -ENOTTY;
 }

 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
 {
 	struct snd_hwdep *hw = file->private_data;
 	if (hw->ops.mmap)
 		return hw->ops.mmap(hw, file, vma);
 	return -ENXIO;
 }

 static int snd_hwdep_control_ioctl(struct snd_card *card,
 				   struct snd_ctl_file * control,
 				   unsigned int cmd, unsigned long arg)
 {
 	switch (cmd) {
 	case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
 		{
 			int device;

 			if (get_user(device, (int __user *)arg))
 				return -EFAULT;
 			mutex_lock(&register_mutex);

 			if (device < 0)
 				device = 0;
 			else if (device < SNDRV_MINOR_HWDEPS)
 				device++;
 			else
 				device = SNDRV_MINOR_HWDEPS;

 			while (device < SNDRV_MINOR_HWDEPS) {
 				if (snd_hwdep_search(card, device))
 					break;
 				device++;
 			}
 			if (device >= SNDRV_MINOR_HWDEPS)
 				device = -1;
 			mutex_unlock(&register_mutex);
 			if (put_user(device, (int __user *)arg))
 				return -EFAULT;
 			return 0;
 		}
 	case SNDRV_CTL_IOCTL_HWDEP_INFO:
 		{
 			struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
 			int device, err;
 			struct snd_hwdep *hwdep;

 			if (get_user(device, &info->device))
 				return -EFAULT;
 			mutex_lock(&register_mutex);
 			hwdep = snd_hwdep_search(card, device);
 			if (hwdep)
 				err = snd_hwdep_info(hwdep, info);
 			else
 				err = -ENXIO;
 			mutex_unlock(&register_mutex);
 			return err;
 		}
 	}
 	return -ENOIOCTLCMD;
 }

 #ifdef CONFIG_COMPAT
 #include "hwdep_compat.c"
 #else
 #define snd_hwdep_ioctl_compat	NULL
 #endif

 /*

  */

 static const struct file_operations snd_hwdep_f_ops =
 {
 	.owner = 	THIS_MODULE,
 	.llseek =	snd_hwdep_llseek,
 	.read = 	snd_hwdep_read,
 	.write =	snd_hwdep_write,
 	.open =		snd_hwdep_open,
 	.release =	snd_hwdep_release,
 	.poll =		snd_hwdep_poll,
 	.unlocked_ioctl =	snd_hwdep_ioctl,
 	.compat_ioctl =	snd_hwdep_ioctl_compat,
 	.mmap =		snd_hwdep_mmap,
 };

 static void release_hwdep_device(struct device *dev)
 {
 	kfree(container_of(dev, struct snd_hwdep, dev));
 }

 /**
  * snd_hwdep_new - create a new hwdep instance
  * @card: the card instance
  * @id: the id string
  * @device: the device index (zero-based)
  * @rhwdep: the pointer to store the new hwdep instance
  *
  * Creates a new hwdep instance with the given index on the card.
  * The callbacks (hwdep->ops) must be set on the returned instance
  * after this call manually by the caller.
  *
  * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_hwdep_new(struct snd_card *card, char *id, int device,
 		  struct snd_hwdep **rhwdep)
 {
 	struct snd_hwdep *hwdep;
 	int err;
 	static const struct snd_device_ops ops = {
 		.dev_free = snd_hwdep_dev_free,
 		.dev_register = snd_hwdep_dev_register,
 		.dev_disconnect = snd_hwdep_dev_disconnect,
 	};

 	if (snd_BUG_ON(!card))
 		return -ENXIO;
 	if (rhwdep)
 		*rhwdep = NULL;
 	hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
 	if (!hwdep)
 		return -ENOMEM;

 	init_waitqueue_head(&hwdep->open_wait);
 	mutex_init(&hwdep->open_mutex);
 	hwdep->card = card;
 	hwdep->device = device;
 	if (id)
 		strlcpy(hwdep->id, id, sizeof(hwdep->id));

 	snd_device_initialize(&hwdep->dev, card);
 	hwdep->dev.release = release_hwdep_device;
 	dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
 #ifdef CONFIG_SND_OSSEMUL
 	hwdep->oss_type = -1;
 #endif

 	err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
 	if (err < 0) {
 		put_device(&hwdep->dev);
 		return err;
 	}

 	if (rhwdep)
 		*rhwdep = hwdep;
 	return 0;
 }
 EXPORT_SYMBOL(snd_hwdep_new);

 static int snd_hwdep_dev_free(struct snd_device *device)
 {
 	struct snd_hwdep *hwdep = device->device_data;
 	if (!hwdep)
 		return 0;
 	if (hwdep->private_free)
 		hwdep->private_free(hwdep);
 	put_device(&hwdep->dev);
 	return 0;
 }

 static int snd_hwdep_dev_register(struct snd_device *device)
 {
 	struct snd_hwdep *hwdep = device->device_data;
 	struct snd_card *card = hwdep->card;
 	int err;

 	mutex_lock(&register_mutex);
 	if (snd_hwdep_search(card, hwdep->device)) {
 		mutex_unlock(&register_mutex);
 		return -EBUSY;
 	}
 	list_add_tail(&hwdep->list, &snd_hwdep_devices);
 	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
 				  hwdep->card, hwdep->device,
 				  &snd_hwdep_f_ops, hwdep, &hwdep->dev);
 	if (err < 0) {
 		dev_err(&hwdep->dev, "unable to register\n");
 		list_del(&hwdep->list);
 		mutex_unlock(&register_mutex);
 		return err;
 	}

 #ifdef CONFIG_SND_OSSEMUL
 	hwdep->ossreg = 0;
 	if (hwdep->oss_type >= 0) {
 		if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
 		    hwdep->device)
 			dev_warn(&hwdep->dev,
 				 "only hwdep device 0 can be registered as OSS direct FM device!\n");
 		else if (snd_register_oss_device(hwdep->oss_type,
 						 card, hwdep->device,
 						 &snd_hwdep_f_ops, hwdep) < 0)
 			dev_warn(&hwdep->dev,
 				 "unable to register OSS compatibility device\n");
 		else
 			hwdep->ossreg = 1;
 	}
 #endif
 	mutex_unlock(&register_mutex);
 	return 0;
 }

 static int snd_hwdep_dev_disconnect(struct snd_device *device)
 {
 	struct snd_hwdep *hwdep = device->device_data;

 	if (snd_BUG_ON(!hwdep))
 		return -ENXIO;
 	mutex_lock(&register_mutex);
 	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
 		mutex_unlock(&register_mutex);
 		return -EINVAL;
 	}
 	mutex_lock(&hwdep->open_mutex);
 	wake_up(&hwdep->open_wait);
 #ifdef CONFIG_SND_OSSEMUL
 	if (hwdep->ossreg)
 		snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
 #endif
 	snd_unregister_device(&hwdep->dev);
 	list_del_init(&hwdep->list);
 	mutex_unlock(&hwdep->open_mutex);
 	mutex_unlock(&register_mutex);
 	return 0;
 }

 #ifdef CONFIG_SND_PROC_FS
 /*
  *  Info interface
  */

 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
 				struct snd_info_buffer *buffer)
 {
 	struct snd_hwdep *hwdep;

 	mutex_lock(&register_mutex);
 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
 		snd_iprintf(buffer, "%02i-%02i: %s\n",
 			    hwdep->card->number, hwdep->device, hwdep->name);
 	mutex_unlock(&register_mutex);
 }

 static struct snd_info_entry *snd_hwdep_proc_entry;

 static void __init snd_hwdep_proc_init(void)
 {
 	struct snd_info_entry *entry;

 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
 		entry->c.text.read = snd_hwdep_proc_read;
 		if (snd_info_register(entry) < 0) {
 			snd_info_free_entry(entry);
 			entry = NULL;
 		}
 	}
 	snd_hwdep_proc_entry = entry;
 }

 static void __exit snd_hwdep_proc_done(void)
 {
 	snd_info_free_entry(snd_hwdep_proc_entry);
 }
 #else /* !CONFIG_SND_PROC_FS */
 #define snd_hwdep_proc_init()
 #define snd_hwdep_proc_done()
 #endif /* CONFIG_SND_PROC_FS */


 /*
  *  ENTRY functions
  */

 static int __init alsa_hwdep_init(void)
 {
 	snd_hwdep_proc_init();
 	snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
 	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
 	return 0;
 }

 static void __exit alsa_hwdep_exit(void)
 {
 	snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
 	snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
 	snd_hwdep_proc_done();
 }

 module_init(alsa_hwdep_init)
 module_exit(alsa_hwdep_exit)
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Hardware dependent layer
	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
	*/

	#include <linux/major.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/time.h>
	#include <linux/mutex.h>
	#include <linux/module.h>
	#include <linux/sched/signal.h>
	#include <sound/core.h>
	#include <sound/control.h>
	#include <sound/minors.h>
	#include <sound/hwdep.h>
	#include <sound/info.h>

	MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
	MODULE_DESCRIPTION("Hardware dependent layer");
	MODULE_LICENSE("GPL");

	static LIST_HEAD(snd_hwdep_devices);
	static DEFINE_MUTEX(register_mutex);

	static int snd_hwdep_dev_free(struct snd_device *device);
	static int snd_hwdep_dev_register(struct snd_device *device);
	static int snd_hwdep_dev_disconnect(struct snd_device *device);


	static struct snd_hwdep snd_hwdep_search(struct snd_card card, int device)
	{
	struct snd_hwdep *hwdep;

	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
	if (hwdep->card == card && hwdep->device == device)
	return hwdep;
	return NULL;
	}

	static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
	{
	struct snd_hwdep *hw = file->private_data;
	if (hw->ops.llseek)
	return hw->ops.llseek(hw, file, offset, orig);
	return -ENXIO;
	}

	static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
	size_t count, loff_t *offset)
	{
	struct snd_hwdep *hw = file->private_data;
	if (hw->ops.read)
	return hw->ops.read(hw, buf, count, offset);
	return -ENXIO;
	}

	static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
	size_t count, loff_t *offset)
	{
	struct snd_hwdep *hw = file->private_data;
	if (hw->ops.write)
	return hw->ops.write(hw, buf, count, offset);
	return -ENXIO;
	}

	static int snd_hwdep_open(struct inode inode, struct file file)
	{
	int major = imajor(inode);
	struct snd_hwdep *hw;
	int err;
	wait_queue_entry_t wait;

	if (major == snd_major) {
	hw = snd_lookup_minor_data(iminor(inode),
	SNDRV_DEVICE_TYPE_HWDEP);
	#ifdef CONFIG_SND_OSSEMUL
	} else if (major == SOUND_MAJOR) {
	hw = snd_lookup_oss_minor_data(iminor(inode),
	SNDRV_OSS_DEVICE_TYPE_DMFM);
	#endif
	} else
	return -ENXIO;
	if (hw == NULL)
	return -ENODEV;

	if (!try_module_get(hw->card->module)) {
	snd_card_unref(hw->card);
	return -EFAULT;
	}

	init_waitqueue_entry(&wait, current);
	add_wait_queue(&hw->open_wait, &wait);
	mutex_lock(&hw->open_mutex);
	while (1) {
	if (hw->exclusive && hw->used > 0) {
	err = -EBUSY;
	break;
	}
	if (!hw->ops.open) {
	err = 0;
	break;
	}
	err = hw->ops.open(hw, file);
	if (err >= 0)
	break;
	if (err == -EAGAIN) {
	if (file->f_flags & O_NONBLOCK) {
	err = -EBUSY;
	break;
	}
	} else
	break;
	set_current_state(TASK_INTERRUPTIBLE);
	mutex_unlock(&hw->open_mutex);
	schedule();
	mutex_lock(&hw->open_mutex);
	if (hw->card->shutdown) {
	err = -ENODEV;
	break;
	}
	if (signal_pending(current)) {
	err = -ERESTARTSYS;
	break;
	}
	}
	remove_wait_queue(&hw->open_wait, &wait);
	if (err >= 0) {
	err = snd_card_file_add(hw->card, file);
	if (err >= 0) {
	file->private_data = hw;
	hw->used++;
	} else {
	if (hw->ops.release)
	hw->ops.release(hw, file);
	}
	}
	mutex_unlock(&hw->open_mutex);
	if (err < 0)
	module_put(hw->card->module);
	snd_card_unref(hw->card);
	return err;
	}

	static int snd_hwdep_release(struct inode inode, struct file file)
	{
	int err = 0;
	struct snd_hwdep *hw = file->private_data;
	struct module *mod = hw->card->module;

	mutex_lock(&hw->open_mutex);
	if (hw->ops.release)
	err = hw->ops.release(hw, file);
	if (hw->used > 0)
	hw->used--;
	mutex_unlock(&hw->open_mutex);
	wake_up(&hw->open_wait);

	snd_card_file_remove(hw->card, file);
	module_put(mod);
	return err;
	}

	static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
	{
	struct snd_hwdep *hw = file->private_data;
	if (hw->ops.poll)
	return hw->ops.poll(hw, file, wait);
	return 0;
	}

	static int snd_hwdep_info(struct snd_hwdep *hw,
	struct snd_hwdep_info __user *_info)
	{
	struct snd_hwdep_info info;

	memset(&info, 0, sizeof(info));
	info.card = hw->card->number;
	strlcpy(info.id, hw->id, sizeof(info.id));
	strlcpy(info.name, hw->name, sizeof(info.name));
	info.iface = hw->iface;
	if (copy_to_user(_info, &info, sizeof(info)))
	return -EFAULT;
	return 0;
	}

	static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
	struct snd_hwdep_dsp_status __user *_info)
	{
	struct snd_hwdep_dsp_status info;
	int err;

	if (! hw->ops.dsp_status)
	return -ENXIO;
	memset(&info, 0, sizeof(info));
	info.dsp_loaded = hw->dsp_loaded;
	if ((err = hw->ops.dsp_status(hw, &info)) < 0)
	return err;
	if (copy_to_user(_info, &info, sizeof(info)))
	return -EFAULT;
	return 0;
	}

	static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
	struct snd_hwdep_dsp_image __user *_info)
	{
	struct snd_hwdep_dsp_image info;
	int err;

	if (! hw->ops.dsp_load)
	return -ENXIO;
	memset(&info, 0, sizeof(info));
	if (copy_from_user(&info, _info, sizeof(info)))
	return -EFAULT;
	if (info.index >= 32)
	return -EINVAL;
	/* check whether the dsp was already loaded */
	if (hw->dsp_loaded & (1 << info.index))
	return -EBUSY;
	err = hw->ops.dsp_load(hw, &info);
	if (err < 0)
	return err;
	hw->dsp_loaded \|= (1 << info.index);
	return 0;
	}

	static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
	unsigned long arg)
	{
	struct snd_hwdep *hw = file->private_data;
	void __user argp = (void __user )arg;
	switch (cmd) {
	case SNDRV_HWDEP_IOCTL_PVERSION:
	return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
	case SNDRV_HWDEP_IOCTL_INFO:
	return snd_hwdep_info(hw, argp);
	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
	return snd_hwdep_dsp_status(hw, argp);
	case SNDRV_HWDEP_IOCTL_DSP_LOAD:
	return snd_hwdep_dsp_load(hw, argp);
	}
	if (hw->ops.ioctl)
	return hw->ops.ioctl(hw, file, cmd, arg);
	return -ENOTTY;
	}

	static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
	{
	struct snd_hwdep *hw = file->private_data;
	if (hw->ops.mmap)
	return hw->ops.mmap(hw, file, vma);
	return -ENXIO;
	}

	static int snd_hwdep_control_ioctl(struct snd_card *card,
	struct snd_ctl_file * control,
	unsigned int cmd, unsigned long arg)
	{
	switch (cmd) {
	case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
	{
	int device;

	if (get_user(device, (int __user *)arg))
	return -EFAULT;
	mutex_lock(&register_mutex);

	if (device < 0)
	device = 0;
	else if (device < SNDRV_MINOR_HWDEPS)
	device++;
	else
	device = SNDRV_MINOR_HWDEPS;

	while (device < SNDRV_MINOR_HWDEPS) {
	if (snd_hwdep_search(card, device))
	break;
	device++;
	}
	if (device >= SNDRV_MINOR_HWDEPS)
	device = -1;
	mutex_unlock(&register_mutex);
	if (put_user(device, (int __user *)arg))
	return -EFAULT;
	return 0;
	}
	case SNDRV_CTL_IOCTL_HWDEP_INFO:
	{
	struct snd_hwdep_info __user info = (struct snd_hwdep_info __user )arg;
	int device, err;
	struct snd_hwdep *hwdep;

	if (get_user(device, &info->device))
	return -EFAULT;
	mutex_lock(&register_mutex);
	hwdep = snd_hwdep_search(card, device);
	if (hwdep)
	err = snd_hwdep_info(hwdep, info);
	else
	err = -ENXIO;
	mutex_unlock(&register_mutex);
	return err;
	}
	}
	return -ENOIOCTLCMD;
	}

	#ifdef CONFIG_COMPAT
	#include "hwdep_compat.c"
	#else
	#define snd_hwdep_ioctl_compat NULL
	#endif

	/*

	*/

	static const struct file_operations snd_hwdep_f_ops =
	{
	.owner = THIS_MODULE,
	.llseek = snd_hwdep_llseek,
	.read = snd_hwdep_read,
	.write = snd_hwdep_write,
	.open = snd_hwdep_open,
	.release = snd_hwdep_release,
	.poll = snd_hwdep_poll,
	.unlocked_ioctl = snd_hwdep_ioctl,
	.compat_ioctl = snd_hwdep_ioctl_compat,
	.mmap = snd_hwdep_mmap,
	};

	static void release_hwdep_device(struct device *dev)
	{
	kfree(container_of(dev, struct snd_hwdep, dev));
	}

	/**
	* snd_hwdep_new - create a new hwdep instance
	* @card: the card instance
	* @id: the id string
	* @device: the device index (zero-based)
	* @rhwdep: the pointer to store the new hwdep instance
	*
	* Creates a new hwdep instance with the given index on the card.
	* The callbacks (hwdep->ops) must be set on the returned instance
	* after this call manually by the caller.
	*
	* Return: Zero if successful, or a negative error code on failure.
	*/
	int snd_hwdep_new(struct snd_card card, char id, int device,
	struct snd_hwdep **rhwdep)
	{
	struct snd_hwdep *hwdep;
	int err;
	static const struct snd_device_ops ops = {
	.dev_free = snd_hwdep_dev_free,
	.dev_register = snd_hwdep_dev_register,
	.dev_disconnect = snd_hwdep_dev_disconnect,
	};

	if (snd_BUG_ON(!card))
	return -ENXIO;
	if (rhwdep)
	*rhwdep = NULL;
	hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
	if (!hwdep)
	return -ENOMEM;

	init_waitqueue_head(&hwdep->open_wait);
	mutex_init(&hwdep->open_mutex);
	hwdep->card = card;
	hwdep->device = device;
	if (id)
	strlcpy(hwdep->id, id, sizeof(hwdep->id));

	snd_device_initialize(&hwdep->dev, card);
	hwdep->dev.release = release_hwdep_device;
	dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
	#ifdef CONFIG_SND_OSSEMUL
	hwdep->oss_type = -1;
	#endif

	err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
	if (err < 0) {
	put_device(&hwdep->dev);
	return err;
	}

	if (rhwdep)
	*rhwdep = hwdep;
	return 0;
	}
	EXPORT_SYMBOL(snd_hwdep_new);

	static int snd_hwdep_dev_free(struct snd_device *device)
	{
	struct snd_hwdep *hwdep = device->device_data;
	if (!hwdep)
	return 0;
	if (hwdep->private_free)
	hwdep->private_free(hwdep);
	put_device(&hwdep->dev);
	return 0;
	}

	static int snd_hwdep_dev_register(struct snd_device *device)
	{
	struct snd_hwdep *hwdep = device->device_data;
	struct snd_card *card = hwdep->card;
	int err;

	mutex_lock(&register_mutex);
	if (snd_hwdep_search(card, hwdep->device)) {
	mutex_unlock(&register_mutex);
	return -EBUSY;
	}
	list_add_tail(&hwdep->list, &snd_hwdep_devices);
	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
	hwdep->card, hwdep->device,
	&snd_hwdep_f_ops, hwdep, &hwdep->dev);
	if (err < 0) {
	dev_err(&hwdep->dev, "unable to register\n");
	list_del(&hwdep->list);
	mutex_unlock(&register_mutex);
	return err;
	}

	#ifdef CONFIG_SND_OSSEMUL
	hwdep->ossreg = 0;
	if (hwdep->oss_type >= 0) {
	if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
	hwdep->device)
	dev_warn(&hwdep->dev,
	"only hwdep device 0 can be registered as OSS direct FM device!\n");
	else if (snd_register_oss_device(hwdep->oss_type,
	card, hwdep->device,
	&snd_hwdep_f_ops, hwdep) < 0)
	dev_warn(&hwdep->dev,
	"unable to register OSS compatibility device\n");
	else
	hwdep->ossreg = 1;
	}
	#endif
	mutex_unlock(&register_mutex);
	return 0;
	}

	static int snd_hwdep_dev_disconnect(struct snd_device *device)
	{
	struct snd_hwdep *hwdep = device->device_data;

	if (snd_BUG_ON(!hwdep))
	return -ENXIO;
	mutex_lock(&register_mutex);
	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
	mutex_unlock(&register_mutex);
	return -EINVAL;
	}
	mutex_lock(&hwdep->open_mutex);
	wake_up(&hwdep->open_wait);
	#ifdef CONFIG_SND_OSSEMUL
	if (hwdep->ossreg)
	snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
	#endif
	snd_unregister_device(&hwdep->dev);
	list_del_init(&hwdep->list);
	mutex_unlock(&hwdep->open_mutex);
	mutex_unlock(&register_mutex);
	return 0;
	}

	#ifdef CONFIG_SND_PROC_FS
	/*
	* Info interface
	*/

	static void snd_hwdep_proc_read(struct snd_info_entry *entry,
	struct snd_info_buffer *buffer)
	{
	struct snd_hwdep *hwdep;

	mutex_lock(&register_mutex);
	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
	snd_iprintf(buffer, "%02i-%02i: %s\n",
	hwdep->card->number, hwdep->device, hwdep->name);
	mutex_unlock(&register_mutex);
	}

	static struct snd_info_entry *snd_hwdep_proc_entry;

	static void __init snd_hwdep_proc_init(void)
	{
	struct snd_info_entry *entry;

	if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
	entry->c.text.read = snd_hwdep_proc_read;
	if (snd_info_register(entry) < 0) {
	snd_info_free_entry(entry);
	entry = NULL;
	}
	}
	snd_hwdep_proc_entry = entry;
	}

	static void __exit snd_hwdep_proc_done(void)
	{
	snd_info_free_entry(snd_hwdep_proc_entry);
	}
	#else /* !CONFIG_SND_PROC_FS */
	#define snd_hwdep_proc_init()
	#define snd_hwdep_proc_done()
	#endif /* CONFIG_SND_PROC_FS */


	/*
	* ENTRY functions
	*/

	static int __init alsa_hwdep_init(void)
	{
	snd_hwdep_proc_init();
	snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
	return 0;
	}

	static void __exit alsa_hwdep_exit(void)
	{
	snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
	snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
	snd_hwdep_proc_done();
	}

	module_init(alsa_hwdep_init)
	module_exit(alsa_hwdep_exit)