include/sound/core.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 #ifndef __SOUND_CORE_H
 #define __SOUND_CORE_H

 /*
  *  Main header file for the ALSA driver
  *  Copyright (c) 1994-2001 by Jaroslav Kysela <perex@perex.cz>
  */

 #include <linux/device.h>
 #include <linux/sched.h>		/* wake_up() */
 #include <linux/mutex.h>		/* struct mutex */
 #include <linux/rwsem.h>		/* struct rw_semaphore */
 #include <linux/pm.h>			/* pm_message_t */
 #include <linux/stringify.h>
 #include <linux/printk.h>
 #include <linux/xarray.h>

 /* number of supported soundcards */
 #ifdef CONFIG_SND_DYNAMIC_MINORS
 #define SNDRV_CARDS CONFIG_SND_MAX_CARDS
 #else
 #define SNDRV_CARDS 8		/* don't change - minor numbers */
 #endif

 #define CONFIG_SND_MAJOR	116	/* standard configuration */

 /* forward declarations */
 struct pci_dev;
 struct module;
 struct completion;

 /* device allocation stuff */

 /* type of the object used in snd_device_*()
  * this also defines the calling order
  */
 enum snd_device_type {
 	SNDRV_DEV_LOWLEVEL,
 	SNDRV_DEV_INFO,
 	SNDRV_DEV_BUS,
 	SNDRV_DEV_CODEC,
 	SNDRV_DEV_PCM,
 	SNDRV_DEV_COMPRESS,
 	SNDRV_DEV_RAWMIDI,
 	SNDRV_DEV_TIMER,
 	SNDRV_DEV_SEQUENCER,
 	SNDRV_DEV_HWDEP,
 	SNDRV_DEV_JACK,
 	SNDRV_DEV_CONTROL,	/* NOTE: this must be the last one */
 };

 enum snd_device_state {
 	SNDRV_DEV_BUILD,
 	SNDRV_DEV_REGISTERED,
 	SNDRV_DEV_DISCONNECTED,
 };

 struct snd_device;

 struct snd_device_ops {
 	int (*dev_free)(struct snd_device *dev);
 	int (*dev_register)(struct snd_device *dev);
 	int (*dev_disconnect)(struct snd_device *dev);
 };

 struct snd_device {
 	struct list_head list;		/* list of registered devices */
 	struct snd_card *card;		/* card which holds this device */
 	enum snd_device_state state;	/* state of the device */
 	enum snd_device_type type;	/* device type */
 	void *device_data;		/* device structure */
 	const struct snd_device_ops *ops;	/* operations */
 };

 #define snd_device(n) list_entry(n, struct snd_device, list)

 /* main structure for soundcard */

 struct snd_card {
 	int number;			/* number of soundcard (index to
 								snd_cards) */

 	char id[16];			/* id string of this card */
 	char driver[16];		/* driver name */
 	char shortname[32];		/* short name of this soundcard */
 	char longname[80];		/* name of this soundcard */
 	char irq_descr[32];		/* Interrupt description */
 	char mixername[80];		/* mixer name */
 	char components[128];		/* card components delimited with
 								space */
 	struct module *module;		/* top-level module */

 	void *private_data;		/* private data for soundcard */
 	void (*private_free) (struct snd_card *card); /* callback for freeing of
 								private data */
 	struct list_head devices;	/* devices */

 	struct device *ctl_dev;		/* control device */
 	unsigned int last_numid;	/* last used numeric ID */
 	struct rw_semaphore controls_rwsem;	/* controls lock (list and values) */
 	rwlock_t controls_rwlock;	/* lock for lookup and ctl_files list */
 	int controls_count;		/* count of all controls */
 	size_t user_ctl_alloc_size;	// current memory allocation by user controls.
 	struct list_head controls;	/* all controls for this card */
 	struct list_head ctl_files;	/* active control files */
 #ifdef CONFIG_SND_CTL_FAST_LOOKUP
 	struct xarray ctl_numids;	/* hash table for numids */
 	struct xarray ctl_hash;		/* hash table for ctl id matching */
 	bool ctl_hash_collision;	/* ctl_hash collision seen? */
 #endif

 	struct snd_info_entry *proc_root;	/* root for soundcard specific files */
 	struct proc_dir_entry *proc_root_link;	/* number link to real id */

 	struct list_head files_list;	/* all files associated to this card */
 	struct snd_shutdown_f_ops *s_f_ops; /* file operations in the shutdown
 								state */
 	spinlock_t files_lock;		/* lock the files for this card */
 	int shutdown;			/* this card is going down */
 	struct completion *release_completion;
 	struct device *dev;		/* device assigned to this card */
 	struct device card_dev;		/* cardX object for sysfs */
 	const struct attribute_group *dev_groups[4]; /* assigned sysfs attr */
 	bool registered;		/* card_dev is registered? */
 	bool managed;			/* managed via devres */
 	bool releasing;			/* during card free process */
 	int sync_irq;			/* assigned irq, used for PCM sync */
 	wait_queue_head_t remove_sleep;

 	size_t total_pcm_alloc_bytes;	/* total amount of allocated buffers */
 	struct mutex memory_mutex;	/* protection for the above */
 #ifdef CONFIG_SND_DEBUG
 	struct dentry *debugfs_root;    /* debugfs root for card */
 #endif

 #ifdef CONFIG_PM
 	unsigned int power_state;	/* power state */
 	atomic_t power_ref;
 	wait_queue_head_t power_sleep;
 	wait_queue_head_t power_ref_sleep;
 #endif

 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 	struct snd_mixer_oss *mixer_oss;
 	int mixer_oss_change_count;
 #endif
 };

 #define dev_to_snd_card(p)	container_of(p, struct snd_card, card_dev)

 #ifdef CONFIG_PM
 static inline unsigned int snd_power_get_state(struct snd_card *card)
 {
 	return READ_ONCE(card->power_state);
 }

 static inline void snd_power_change_state(struct snd_card *card, unsigned int state)
 {
 	WRITE_ONCE(card->power_state, state);
 	wake_up(&card->power_sleep);
 }

 /**
  * snd_power_ref - Take the reference count for power control
  * @card: sound card object
  *
  * The power_ref reference of the card is used for managing to block
  * the snd_power_sync_ref() operation.  This function increments the reference.
  * The counterpart snd_power_unref() has to be called appropriately later.
  */
 static inline void snd_power_ref(struct snd_card *card)
 {
 	atomic_inc(&card->power_ref);
 }

 /**
  * snd_power_unref - Release the reference count for power control
  * @card: sound card object
  */
 static inline void snd_power_unref(struct snd_card *card)
 {
 	if (atomic_dec_and_test(&card->power_ref))
 		wake_up(&card->power_ref_sleep);
 }

 /**
  * snd_power_sync_ref - wait until the card power_ref is freed
  * @card: sound card object
  *
  * This function is used to synchronize with the pending power_ref being
  * released.
  */
 static inline void snd_power_sync_ref(struct snd_card *card)
 {
 	wait_event(card->power_ref_sleep, !atomic_read(&card->power_ref));
 }

 /* init.c */
 int snd_power_wait(struct snd_card *card);
 int snd_power_ref_and_wait(struct snd_card *card);

 #else /* ! CONFIG_PM */

 static inline int snd_power_wait(struct snd_card *card) { return 0; }
 static inline void snd_power_ref(struct snd_card *card) {}
 static inline void snd_power_unref(struct snd_card *card) {}
 static inline int snd_power_ref_and_wait(struct snd_card *card) { return 0; }
 static inline void snd_power_sync_ref(struct snd_card *card) {}
 #define snd_power_get_state(card)	({ (void)(card); SNDRV_CTL_POWER_D0; })
 #define snd_power_change_state(card, state)	do { (void)(card); } while (0)

 #endif /* CONFIG_PM */

 struct snd_minor {
 	int type;			/* SNDRV_DEVICE_TYPE_XXX */
 	int card;			/* card number */
 	int device;			/* device number */
 	const struct file_operations *f_ops;	/* file operations */
 	void *private_data;		/* private data for f_ops->open */
 	struct device *dev;		/* device for sysfs */
 	struct snd_card *card_ptr;	/* assigned card instance */
 };

 /* return a device pointer linked to each sound device as a parent */
 static inline struct device *snd_card_get_device_link(struct snd_card *card)
 {
 	return card ? &card->card_dev : NULL;
 }

 /* sound.c */

 extern int snd_major;
 extern int snd_ecards_limit;
 extern const struct class sound_class;
 #ifdef CONFIG_SND_DEBUG
 extern struct dentry *sound_debugfs_root;
 #endif

 void snd_request_card(int card);

 int snd_device_alloc(struct device **dev_p, struct snd_card *card);

 int snd_register_device(int type, struct snd_card *card, int dev,
 			const struct file_operations *f_ops,
 			void *private_data, struct device *device);
 int snd_unregister_device(struct device *dev);
 void *snd_lookup_minor_data(unsigned int minor, int type);

 #ifdef CONFIG_SND_OSSEMUL
 int snd_register_oss_device(int type, struct snd_card *card, int dev,
 			    const struct file_operations *f_ops, void *private_data);
 int snd_unregister_oss_device(int type, struct snd_card *card, int dev);
 void *snd_lookup_oss_minor_data(unsigned int minor, int type);
 #endif

 int snd_minor_info_init(void);

 /* sound_oss.c */

 #ifdef CONFIG_SND_OSSEMUL
 int snd_minor_info_oss_init(void);
 #else
 static inline int snd_minor_info_oss_init(void) { return 0; }
 #endif

 /* memory.c */

 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count);
 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count);

 /* init.c */

 int snd_card_locked(int card);
 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 #define SND_MIXER_OSS_NOTIFY_REGISTER	0
 #define SND_MIXER_OSS_NOTIFY_DISCONNECT	1
 #define SND_MIXER_OSS_NOTIFY_FREE	2
 extern int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int cmd);
 #endif

 int snd_card_new(struct device *parent, int idx, const char *xid,
 		 struct module *module, int extra_size,
 		 struct snd_card **card_ret);
 int snd_devm_card_new(struct device *parent, int idx, const char *xid,
 		      struct module *module, size_t extra_size,
 		      struct snd_card **card_ret);

 void snd_card_disconnect(struct snd_card *card);
 void snd_card_disconnect_sync(struct snd_card *card);
 void snd_card_free(struct snd_card *card);
 void snd_card_free_when_closed(struct snd_card *card);
 int snd_card_free_on_error(struct device *dev, int ret);
 void snd_card_set_id(struct snd_card *card, const char *id);
 int snd_card_register(struct snd_card *card);
 int snd_card_info_init(void);
 int snd_card_add_dev_attr(struct snd_card *card,
 			  const struct attribute_group *group);
 int snd_component_add(struct snd_card *card, const char *component);
 int snd_card_file_add(struct snd_card *card, struct file *file);
 int snd_card_file_remove(struct snd_card *card, struct file *file);

 struct snd_card *snd_card_ref(int card);

 /**
  * snd_card_unref - Unreference the card object
  * @card: the card object to unreference
  *
  * Call this function for the card object that was obtained via snd_card_ref()
  * or snd_lookup_minor_data().
  */
 static inline void snd_card_unref(struct snd_card *card)
 {
 	put_device(&card->card_dev);
 }

 #define snd_card_set_dev(card, devptr) ((card)->dev = (devptr))

 /* device.c */

 int snd_device_new(struct snd_card *card, enum snd_device_type type,
 		   void *device_data, const struct snd_device_ops *ops);
 int snd_device_register(struct snd_card *card, void *device_data);
 int snd_device_register_all(struct snd_card *card);
 void snd_device_disconnect(struct snd_card *card, void *device_data);
 void snd_device_disconnect_all(struct snd_card *card);
 void snd_device_free(struct snd_card *card, void *device_data);
 void snd_device_free_all(struct snd_card *card);
 int snd_device_get_state(struct snd_card *card, void *device_data);

 /* isadma.c */

 #ifdef CONFIG_ISA_DMA_API
 #define DMA_MODE_NO_ENABLE	0x0100

 void snd_dma_program(unsigned long dma, unsigned long addr, unsigned int size, unsigned short mode);
 void snd_dma_disable(unsigned long dma);
 unsigned int snd_dma_pointer(unsigned long dma, unsigned int size);
 int snd_devm_request_dma(struct device *dev, int dma, const char *name);
 #endif

 /* misc.c */
 struct resource;
 void release_and_free_resource(struct resource *res);

 /* --- */

 #ifdef CONFIG_SND_DEBUG
 /**
  * snd_BUG - give a BUG warning message and stack trace
  *
  * Calls WARN() if CONFIG_SND_DEBUG is set.
  * Ignored when CONFIG_SND_DEBUG is not set.
  */
 #define snd_BUG()		WARN(1, "BUG?\n")

 /**
  * snd_BUG_ON - debugging check macro
  * @cond: condition to evaluate
  *
  * Has the same behavior as WARN_ON when CONFIG_SND_DEBUG is set,
  * otherwise just evaluates the conditional and returns the value.
  */
 #define snd_BUG_ON(cond)	WARN_ON((cond))

 #else /* !CONFIG_SND_DEBUG */

 #define snd_BUG()			do { } while (0)

 #define snd_BUG_ON(condition) ({ \
 	int __ret_warn_on = !!(condition); \
 	unlikely(__ret_warn_on); \
 })

 #endif /* CONFIG_SND_DEBUG */

 #define SNDRV_OSS_VERSION         ((3<<16)|(8<<8)|(1<<4)|(0))	/* 3.8.1a */

 /* for easier backward-porting */
 #if IS_ENABLED(CONFIG_GAMEPORT)
 #define gameport_set_dev_parent(gp,xdev) ((gp)->dev.parent = (xdev))
 #define gameport_set_port_data(gp,r) ((gp)->port_data = (r))
 #define gameport_get_port_data(gp) (gp)->port_data
 #endif

 /* PCI quirk list helper */
 struct snd_pci_quirk {
 	unsigned short subvendor;	/* PCI subvendor ID */
 	unsigned short subdevice;	/* PCI subdevice ID */
 	unsigned short subdevice_mask;	/* bitmask to match */
 	int value;			/* value */
 #ifdef CONFIG_SND_DEBUG_VERBOSE
 	const char *name;		/* name of the device (optional) */
 #endif
 };

 #define _SND_PCI_QUIRK_ID_MASK(vend, mask, dev)	\
 	.subvendor = (vend), .subdevice = (dev), .subdevice_mask = (mask)
 #define _SND_PCI_QUIRK_ID(vend, dev) \
 	_SND_PCI_QUIRK_ID_MASK(vend, 0xffff, dev)
 #define SND_PCI_QUIRK_ID(vend,dev) {_SND_PCI_QUIRK_ID(vend, dev)}
 #ifdef CONFIG_SND_DEBUG_VERBOSE
 #define SND_PCI_QUIRK(vend,dev,xname,val) \
 	{_SND_PCI_QUIRK_ID(vend, dev), .value = (val), .name = (xname)}
 #define SND_PCI_QUIRK_VENDOR(vend, xname, val)			\
 	{_SND_PCI_QUIRK_ID_MASK(vend, 0, 0), .value = (val), .name = (xname)}
 #define SND_PCI_QUIRK_MASK(vend, mask, dev, xname, val)			\
 	{_SND_PCI_QUIRK_ID_MASK(vend, mask, dev),			\
 			.value = (val), .name = (xname)}
 #define snd_pci_quirk_name(q)	((q)->name)
 #else
 #define SND_PCI_QUIRK(vend,dev,xname,val) \
 	{_SND_PCI_QUIRK_ID(vend, dev), .value = (val)}
 #define SND_PCI_QUIRK_MASK(vend, mask, dev, xname, val)			\
 	{_SND_PCI_QUIRK_ID_MASK(vend, mask, dev), .value = (val)}
 #define SND_PCI_QUIRK_VENDOR(vend, xname, val)			\
 	{_SND_PCI_QUIRK_ID_MASK(vend, 0, 0), .value = (val)}
 #define snd_pci_quirk_name(q)	""
 #endif

 #ifdef CONFIG_PCI
 const struct snd_pci_quirk *
 snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list);

 const struct snd_pci_quirk *
 snd_pci_quirk_lookup_id(u16 vendor, u16 device,
 			const struct snd_pci_quirk *list);
 #else
 static inline const struct snd_pci_quirk *
 snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
 {
 	return NULL;
 }

 static inline const struct snd_pci_quirk *
 snd_pci_quirk_lookup_id(u16 vendor, u16 device,
 			const struct snd_pci_quirk *list)
 {
 	return NULL;
 }
 #endif

 /* async signal helpers */
 struct snd_fasync;

 int snd_fasync_helper(int fd, struct file *file, int on,
 		      struct snd_fasync **fasyncp);
 void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll);
 void snd_fasync_free(struct snd_fasync *fasync);

 #endif /* __SOUND_CORE_H */
	/* SPDX-License-Identifier: GPL-2.0-or-later */
	#ifndef __SOUND_CORE_H
	#define __SOUND_CORE_H

	/*
	* Main header file for the ALSA driver
	* Copyright (c) 1994-2001 by Jaroslav Kysela <perex@perex.cz>
	*/

	#include <linux/device.h>
	#include <linux/sched.h> /* wake_up() */
	#include <linux/mutex.h> /* struct mutex */
	#include <linux/rwsem.h> /* struct rw_semaphore */
	#include <linux/pm.h> /* pm_message_t */
	#include <linux/stringify.h>
	#include <linux/printk.h>
	#include <linux/xarray.h>

	/* number of supported soundcards */
	#ifdef CONFIG_SND_DYNAMIC_MINORS
	#define SNDRV_CARDS CONFIG_SND_MAX_CARDS
	#else
	#define SNDRV_CARDS 8 /* don't change - minor numbers */
	#endif

	#define CONFIG_SND_MAJOR 116 /* standard configuration */

	/* forward declarations */
	struct pci_dev;
	struct module;
	struct completion;

	/* device allocation stuff */

	/* type of the object used in snd_device_*()
	* this also defines the calling order
	*/
	enum snd_device_type {
	SNDRV_DEV_LOWLEVEL,
	SNDRV_DEV_INFO,
	SNDRV_DEV_BUS,
	SNDRV_DEV_CODEC,
	SNDRV_DEV_PCM,
	SNDRV_DEV_COMPRESS,
	SNDRV_DEV_RAWMIDI,
	SNDRV_DEV_TIMER,
	SNDRV_DEV_SEQUENCER,
	SNDRV_DEV_HWDEP,
	SNDRV_DEV_JACK,
	SNDRV_DEV_CONTROL, /* NOTE: this must be the last one */
	};

	enum snd_device_state {
	SNDRV_DEV_BUILD,
	SNDRV_DEV_REGISTERED,
	SNDRV_DEV_DISCONNECTED,
	};

	struct snd_device;

	struct snd_device_ops {
	int (dev_free)(struct snd_device dev);
	int (dev_register)(struct snd_device dev);
	int (dev_disconnect)(struct snd_device dev);
	};

	struct snd_device {
	struct list_head list; /* list of registered devices */
	struct snd_card card; / card which holds this device */
	enum snd_device_state state; /* state of the device */
	enum snd_device_type type; /* device type */
	void device_data; / device structure */
	const struct snd_device_ops ops; / operations */
	};

	#define snd_device(n) list_entry(n, struct snd_device, list)

	/* main structure for soundcard */

	struct snd_card {
	int number; /* number of soundcard (index to
	snd_cards) */

	char id[16]; /* id string of this card */
	char driver[16]; /* driver name */
	char shortname[32]; /* short name of this soundcard */
	char longname[80]; /* name of this soundcard */
	char irq_descr[32]; /* Interrupt description */
	char mixername[80]; /* mixer name */
	char components[128]; /* card components delimited with
	space */
	struct module module; / top-level module */

	void private_data; / private data for soundcard */
	void (private_free) (struct snd_card card); /* callback for freeing of
	private data */
	struct list_head devices; /* devices */

	struct device ctl_dev; / control device */
	unsigned int last_numid; /* last used numeric ID */
	struct rw_semaphore controls_rwsem; /* controls lock (list and values) */
	rwlock_t controls_rwlock; /* lock for lookup and ctl_files list */
	int controls_count; /* count of all controls */
	size_t user_ctl_alloc_size; // current memory allocation by user controls.
	struct list_head controls; /* all controls for this card */
	struct list_head ctl_files; /* active control files */
	#ifdef CONFIG_SND_CTL_FAST_LOOKUP
	struct xarray ctl_numids; /* hash table for numids */
	struct xarray ctl_hash; /* hash table for ctl id matching */
	bool ctl_hash_collision; /* ctl_hash collision seen? */
	#endif

	struct snd_info_entry proc_root; / root for soundcard specific files */
	struct proc_dir_entry proc_root_link; / number link to real id */

	struct list_head files_list; /* all files associated to this card */
	struct snd_shutdown_f_ops s_f_ops; / file operations in the shutdown
	state */
	spinlock_t files_lock; /* lock the files for this card */
	int shutdown; /* this card is going down */
	struct completion *release_completion;
	struct device dev; / device assigned to this card */
	struct device card_dev; /* cardX object for sysfs */
	const struct attribute_group dev_groups[4]; / assigned sysfs attr */
	bool registered; /* card_dev is registered? */
	bool managed; /* managed via devres */
	bool releasing; /* during card free process */
	int sync_irq; /* assigned irq, used for PCM sync */
	wait_queue_head_t remove_sleep;

	size_t total_pcm_alloc_bytes; /* total amount of allocated buffers */
	struct mutex memory_mutex; /* protection for the above */
	#ifdef CONFIG_SND_DEBUG
	struct dentry debugfs_root; / debugfs root for card */
	#endif

	#ifdef CONFIG_PM
	unsigned int power_state; /* power state */
	atomic_t power_ref;
	wait_queue_head_t power_sleep;
	wait_queue_head_t power_ref_sleep;
	#endif

	#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
	struct snd_mixer_oss *mixer_oss;
	int mixer_oss_change_count;
	#endif
	};

	#define dev_to_snd_card(p) container_of(p, struct snd_card, card_dev)

	#ifdef CONFIG_PM
	static inline unsigned int snd_power_get_state(struct snd_card *card)
	{
	return READ_ONCE(card->power_state);
	}

	static inline void snd_power_change_state(struct snd_card *card, unsigned int state)
	{
	WRITE_ONCE(card->power_state, state);
	wake_up(&card->power_sleep);
	}

	/**
	* snd_power_ref - Take the reference count for power control
	* @card: sound card object
	*
	* The power_ref reference of the card is used for managing to block
	* the snd_power_sync_ref() operation. This function increments the reference.
	* The counterpart snd_power_unref() has to be called appropriately later.
	*/
	static inline void snd_power_ref(struct snd_card *card)
	{
	atomic_inc(&card->power_ref);
	}

	/**
	* snd_power_unref - Release the reference count for power control
	* @card: sound card object
	*/
	static inline void snd_power_unref(struct snd_card *card)
	{
	if (atomic_dec_and_test(&card->power_ref))
	wake_up(&card->power_ref_sleep);
	}

	/**
	* snd_power_sync_ref - wait until the card power_ref is freed
	* @card: sound card object
	*
	* This function is used to synchronize with the pending power_ref being
	* released.
	*/
	static inline void snd_power_sync_ref(struct snd_card *card)
	{
	wait_event(card->power_ref_sleep, !atomic_read(&card->power_ref));
	}

	/* init.c */
	int snd_power_wait(struct snd_card *card);
	int snd_power_ref_and_wait(struct snd_card *card);

	#else /* ! CONFIG_PM */

	static inline int snd_power_wait(struct snd_card *card) { return 0; }
	static inline void snd_power_ref(struct snd_card *card) {}
	static inline void snd_power_unref(struct snd_card *card) {}
	static inline int snd_power_ref_and_wait(struct snd_card *card) { return 0; }
	static inline void snd_power_sync_ref(struct snd_card *card) {}
	#define snd_power_get_state(card) ({ (void)(card); SNDRV_CTL_POWER_D0; })
	#define snd_power_change_state(card, state) do { (void)(card); } while (0)

	#endif /* CONFIG_PM */

	struct snd_minor {
	int type; /* SNDRV_DEVICE_TYPE_XXX */
	int card; /* card number */
	int device; /* device number */
	const struct file_operations f_ops; / file operations */
	void private_data; / private data for f_ops->open */
	struct device dev; / device for sysfs */
	struct snd_card card_ptr; / assigned card instance */
	};

	/* return a device pointer linked to each sound device as a parent */
	static inline struct device snd_card_get_device_link(struct snd_card card)
	{
	return card ? &card->card_dev : NULL;
	}

	/* sound.c */

	extern int snd_major;
	extern int snd_ecards_limit;
	extern const struct class sound_class;
	#ifdef CONFIG_SND_DEBUG
	extern struct dentry *sound_debugfs_root;
	#endif

	void snd_request_card(int card);

	int snd_device_alloc(struct device *dev_p, struct snd_card card);

	int snd_register_device(int type, struct snd_card *card, int dev,
	const struct file_operations *f_ops,
	void private_data, struct device device);
	int snd_unregister_device(struct device *dev);
	void *snd_lookup_minor_data(unsigned int minor, int type);

	#ifdef CONFIG_SND_OSSEMUL
	int snd_register_oss_device(int type, struct snd_card *card, int dev,
	const struct file_operations f_ops, void private_data);
	int snd_unregister_oss_device(int type, struct snd_card *card, int dev);
	void *snd_lookup_oss_minor_data(unsigned int minor, int type);
	#endif

	int snd_minor_info_init(void);

	/* sound_oss.c */

	#ifdef CONFIG_SND_OSSEMUL
	int snd_minor_info_oss_init(void);
	#else
	static inline int snd_minor_info_oss_init(void) { return 0; }
	#endif

	/* memory.c */

	int copy_to_user_fromio(void __user dst, const volatile void __iomem src, size_t count);
	int copy_from_user_toio(volatile void __iomem dst, const void __user src, size_t count);

	/* init.c */

	int snd_card_locked(int card);
	#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
	#define SND_MIXER_OSS_NOTIFY_REGISTER 0
	#define SND_MIXER_OSS_NOTIFY_DISCONNECT 1
	#define SND_MIXER_OSS_NOTIFY_FREE 2
	extern int (snd_mixer_oss_notify_callback)(struct snd_card card, int cmd);
	#endif

	int snd_card_new(struct device parent, int idx, const char xid,
	struct module *module, int extra_size,
	struct snd_card **card_ret);
	int snd_devm_card_new(struct device parent, int idx, const char xid,
	struct module *module, size_t extra_size,
	struct snd_card **card_ret);

	void snd_card_disconnect(struct snd_card *card);
	void snd_card_disconnect_sync(struct snd_card *card);
	void snd_card_free(struct snd_card *card);
	void snd_card_free_when_closed(struct snd_card *card);
	int snd_card_free_on_error(struct device *dev, int ret);
	void snd_card_set_id(struct snd_card card, const char id);
	int snd_card_register(struct snd_card *card);
	int snd_card_info_init(void);
	int snd_card_add_dev_attr(struct snd_card *card,
	const struct attribute_group *group);
	int snd_component_add(struct snd_card card, const char component);
	int snd_card_file_add(struct snd_card card, struct file file);
	int snd_card_file_remove(struct snd_card card, struct file file);

	struct snd_card *snd_card_ref(int card);

	/**
	* snd_card_unref - Unreference the card object
	* @card: the card object to unreference
	*
	* Call this function for the card object that was obtained via snd_card_ref()
	* or snd_lookup_minor_data().
	*/
	static inline void snd_card_unref(struct snd_card *card)
	{
	put_device(&card->card_dev);
	}

	#define snd_card_set_dev(card, devptr) ((card)->dev = (devptr))

	/* device.c */

	int snd_device_new(struct snd_card *card, enum snd_device_type type,
	void device_data, const struct snd_device_ops ops);
	int snd_device_register(struct snd_card card, void device_data);
	int snd_device_register_all(struct snd_card *card);
	void snd_device_disconnect(struct snd_card card, void device_data);
	void snd_device_disconnect_all(struct snd_card *card);
	void snd_device_free(struct snd_card card, void device_data);
	void snd_device_free_all(struct snd_card *card);
	int snd_device_get_state(struct snd_card card, void device_data);

	/* isadma.c */

	#ifdef CONFIG_ISA_DMA_API
	#define DMA_MODE_NO_ENABLE 0x0100

	void snd_dma_program(unsigned long dma, unsigned long addr, unsigned int size, unsigned short mode);
	void snd_dma_disable(unsigned long dma);
	unsigned int snd_dma_pointer(unsigned long dma, unsigned int size);
	int snd_devm_request_dma(struct device dev, int dma, const char name);
	#endif

	/* misc.c */
	struct resource;
	void release_and_free_resource(struct resource *res);

	/* --- */

	#ifdef CONFIG_SND_DEBUG
	/**
	* snd_BUG - give a BUG warning message and stack trace
	*
	* Calls WARN() if CONFIG_SND_DEBUG is set.
	* Ignored when CONFIG_SND_DEBUG is not set.
	*/
	#define snd_BUG() WARN(1, "BUG?\n")

	/**
	* snd_BUG_ON - debugging check macro
	* @cond: condition to evaluate
	*
	* Has the same behavior as WARN_ON when CONFIG_SND_DEBUG is set,
	* otherwise just evaluates the conditional and returns the value.
	*/
	#define snd_BUG_ON(cond) WARN_ON((cond))

	#else /* !CONFIG_SND_DEBUG */

	#define snd_BUG() do { } while (0)

	#define snd_BUG_ON(condition) ({ \
	int __ret_warn_on = !!(condition); \
	unlikely(__ret_warn_on); \
	})

	#endif /* CONFIG_SND_DEBUG */

	#define SNDRV_OSS_VERSION ((3<<16)\|(8<<8)\|(1<<4)\|(0)) /* 3.8.1a */

	/* for easier backward-porting */
	#if IS_ENABLED(CONFIG_GAMEPORT)
	#define gameport_set_dev_parent(gp,xdev) ((gp)->dev.parent = (xdev))
	#define gameport_set_port_data(gp,r) ((gp)->port_data = (r))
	#define gameport_get_port_data(gp) (gp)->port_data
	#endif

	/* PCI quirk list helper */
	struct snd_pci_quirk {
	unsigned short subvendor; /* PCI subvendor ID */
	unsigned short subdevice; /* PCI subdevice ID */
	unsigned short subdevice_mask; /* bitmask to match */
	int value; /* value */
	#ifdef CONFIG_SND_DEBUG_VERBOSE
	const char name; / name of the device (optional) */
	#endif
	};

	#define _SND_PCI_QUIRK_ID_MASK(vend, mask, dev) \
	.subvendor = (vend), .subdevice = (dev), .subdevice_mask = (mask)
	#define _SND_PCI_QUIRK_ID(vend, dev) \
	_SND_PCI_QUIRK_ID_MASK(vend, 0xffff, dev)
	#define SND_PCI_QUIRK_ID(vend,dev) {_SND_PCI_QUIRK_ID(vend, dev)}
	#ifdef CONFIG_SND_DEBUG_VERBOSE
	#define SND_PCI_QUIRK(vend,dev,xname,val) \
	{_SND_PCI_QUIRK_ID(vend, dev), .value = (val), .name = (xname)}
	#define SND_PCI_QUIRK_VENDOR(vend, xname, val) \
	{_SND_PCI_QUIRK_ID_MASK(vend, 0, 0), .value = (val), .name = (xname)}
	#define SND_PCI_QUIRK_MASK(vend, mask, dev, xname, val) \
	{_SND_PCI_QUIRK_ID_MASK(vend, mask, dev), \
	.value = (val), .name = (xname)}
	#define snd_pci_quirk_name(q) ((q)->name)
	#else
	#define SND_PCI_QUIRK(vend,dev,xname,val) \
	{_SND_PCI_QUIRK_ID(vend, dev), .value = (val)}
	#define SND_PCI_QUIRK_MASK(vend, mask, dev, xname, val) \
	{_SND_PCI_QUIRK_ID_MASK(vend, mask, dev), .value = (val)}
	#define SND_PCI_QUIRK_VENDOR(vend, xname, val) \
	{_SND_PCI_QUIRK_ID_MASK(vend, 0, 0), .value = (val)}
	#define snd_pci_quirk_name(q) ""
	#endif

	#ifdef CONFIG_PCI
	const struct snd_pci_quirk *
	snd_pci_quirk_lookup(struct pci_dev pci, const struct snd_pci_quirk list);

	const struct snd_pci_quirk *
	snd_pci_quirk_lookup_id(u16 vendor, u16 device,
	const struct snd_pci_quirk *list);
	#else
	static inline const struct snd_pci_quirk *
	snd_pci_quirk_lookup(struct pci_dev pci, const struct snd_pci_quirk list)
	{
	return NULL;
	}

	static inline const struct snd_pci_quirk *
	snd_pci_quirk_lookup_id(u16 vendor, u16 device,
	const struct snd_pci_quirk *list)
	{
	return NULL;
	}
	#endif

	/* async signal helpers */
	struct snd_fasync;

	int snd_fasync_helper(int fd, struct file *file, int on,
	struct snd_fasync **fasyncp);
	void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll);
	void snd_fasync_free(struct snd_fasync *fasync);

	#endif /* __SOUND_CORE_H */