linux/include/sound/info.h

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

/*
 *  Header file for info interface
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <linux/poll.h>
#include <linux/seq_file.h>
#include <sound/core.h>

/* buffer for information */
struct snd_info_buffer {
	char *buffer;		/* pointer to begin of buffer */
	unsigned int curr;	/* current position in buffer */
	unsigned int size;	/* current size */
	unsigned int len;	/* total length of buffer */
	int stop;		/* stop flag */
	int error;		/* error code */
};

#define SNDRV_INFO_CONTENT_TEXT		0
#define SNDRV_INFO_CONTENT_DATA		1

struct snd_info_entry;

struct snd_info_entry_text {
	void (*read)(struct snd_info_entry *entry,
		     struct snd_info_buffer *buffer);
	void (*write)(struct snd_info_entry *entry,
		      struct snd_info_buffer *buffer);
};

struct snd_info_entry_ops {
	int (*open)(struct snd_info_entry *entry,
		    unsigned short mode, void **file_private_data);
	int (*release)(struct snd_info_entry *entry,
		       unsigned short mode, void *file_private_data);
	ssize_t (*read)(struct snd_info_entry *entry, void *file_private_data,
			struct file *file, char __user *buf,
			size_t count, loff_t pos);
	ssize_t (*write)(struct snd_info_entry *entry, void *file_private_data,
			 struct file *file, const char __user *buf,
			 size_t count, loff_t pos);
	loff_t (*llseek)(struct snd_info_entry *entry,
			 void *file_private_data, struct file *file,
			 loff_t offset, int orig);
	__poll_t (*poll)(struct snd_info_entry *entry,
			     void *file_private_data, struct file *file,
			     poll_table *wait);
	int (*ioctl)(struct snd_info_entry *entry, void *file_private_data,
		     struct file *file, unsigned int cmd, unsigned long arg);
	int (*mmap)(struct snd_info_entry *entry, void *file_private_data,
		    struct inode *inode, struct file *file,
		    struct vm_area_struct *vma);
};

struct snd_info_entry {
	const char *name;
	umode_t mode;
	long size;
	unsigned short content;
	union {
		struct snd_info_entry_text text;
		const struct snd_info_entry_ops *ops;
	} c;
	struct snd_info_entry *parent;
	struct module *module;
	void *private_data;
	void (*private_free)(struct snd_info_entry *entry);
	struct proc_dir_entry *p;
	struct mutex access;
	struct list_head children;
	struct list_head list;
};

#if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_SND_PROC_FS)
int snd_info_minor_register(void);
#else
#define snd_info_minor_register()	0
#endif


#ifdef CONFIG_SND_PROC_FS

extern struct snd_info_entry *snd_seq_root;
#ifdef CONFIG_SND_OSSEMUL
extern struct snd_info_entry *snd_oss_root;
void snd_card_info_read_oss(struct snd_info_buffer *buffer);
#else
#define snd_oss_root NULL
static inline void snd_card_info_read_oss(struct snd_info_buffer *buffer) {}
#endif

/**
 * snd_iprintf - printf on the procfs buffer
 * @buf: the procfs buffer
 * @fmt: the printf format
 *
 * Outputs the string on the procfs buffer just like printf().
 *
 * Return: zero for success, or a negative error code.
 */
#define snd_iprintf(buf, fmt, args...) \
	seq_printf((struct seq_file *)(buf)->buffer, fmt, ##args)

int snd_info_init(void);
int snd_info_done(void);

int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len);
const char *snd_info_get_str(char *dest, const char *src, int len);
struct snd_info_entry *snd_info_create_module_entry(struct module *module,
					       const char *name,
					       struct snd_info_entry *parent);
struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
					     const char *name,
					     struct snd_info_entry *parent);
void snd_info_free_entry(struct snd_info_entry *entry);

int snd_info_card_create(struct snd_card *card);
int snd_info_card_register(struct snd_card *card);
int snd_info_card_free(struct snd_card *card);
void snd_info_card_disconnect(struct snd_card *card);
void snd_info_card_id_change(struct snd_card *card);
int snd_info_register(struct snd_info_entry *entry);

/* for card drivers */
static inline int snd_card_proc_new(struct snd_card *card, const char *name,
				    struct snd_info_entry **entryp)
{
	*entryp = snd_info_create_card_entry(card, name, card->proc_root);
	return *entryp ? 0 : -ENOMEM;
}

static inline void snd_info_set_text_ops(struct snd_info_entry *entry, 
	void *private_data,
	void (*read)(struct snd_info_entry *, struct snd_info_buffer *))
{
	entry->private_data = private_data;
	entry->c.text.read = read;
}

int snd_card_rw_proc_new(struct snd_card *card, const char *name,
			 void *private_data,
			 void (*read)(struct snd_info_entry *,
				      struct snd_info_buffer *),
			 void (*write)(struct snd_info_entry *entry,
				       struct snd_info_buffer *buffer));

int snd_info_check_reserved_words(const char *str);

#else

#define snd_seq_root NULL
#define snd_oss_root NULL

static inline int snd_iprintf(struct snd_info_buffer *buffer, char *fmt, ...) { return 0; }
static inline int snd_info_init(void) { return 0; }
static inline int snd_info_done(void) { return 0; }

static inline int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len) { return 0; }
static inline char *snd_info_get_str(char *dest, char *src, int len) { return NULL; }
static inline struct snd_info_entry *snd_info_create_module_entry(struct module *module, const char *name, struct snd_info_entry *parent) { return NULL; }
static inline struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card, const char *name, struct snd_info_entry *parent) { return NULL; }
static inline void snd_info_free_entry(struct snd_info_entry *entry) { ; }

static inline int snd_info_card_create(struct snd_card *card) { return 0; }
static inline int snd_info_card_register(struct snd_card *card) { return 0; }
static inline int snd_info_card_free(struct snd_card *card) { return 0; }
static inline void snd_info_card_disconnect(struct snd_card *card) { }
static inline void snd_info_card_id_change(struct snd_card *card) { }
static inline int snd_info_register(struct snd_info_entry *entry) { return 0; }

static inline int snd_card_proc_new(struct snd_card *card, const char *name,
				    struct snd_info_entry **entryp) { return -EINVAL; }
static inline void snd_info_set_text_ops(struct snd_info_entry *entry __attribute__((unused)),
					 void *private_data,
					 void (*read)(struct snd_info_entry *, struct snd_info_buffer *)) {}
static inline int snd_card_rw_proc_new(struct snd_card *card, const char *name,
				       void *private_data,
				       void (*read)(struct snd_info_entry *,
						    struct snd_info_buffer *),
				       void (*write)(struct snd_info_entry *entry,
						     struct snd_info_buffer *buffer))
{
	return 0;
}
static inline int snd_info_check_reserved_words(const char *str) { return 1; }

#endif

/**
 * snd_card_ro_proc_new - Create a read-only text proc file entry for the card
 * @card: the card instance
 * @name: the file name
 * @private_data: the arbitrary private data
 * @read: the read callback
 *
 * This proc file entry will be registered via snd_card_register() call, and
 * it will be removed automatically at the card removal, too.
 */
static inline int
snd_card_ro_proc_new(struct snd_card *card, const char *name,
		     void *private_data,
		     void (*read)(struct snd_info_entry *,
				  struct snd_info_buffer *))
{
	return snd_card_rw_proc_new(card, name, private_data, read, NULL);
}

/*
 * OSS info part
 */

#if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_SND_PROC_FS)

#define SNDRV_OSS_INFO_DEV_AUDIO	0
#define SNDRV_OSS_INFO_DEV_SYNTH	1
#define SNDRV_OSS_INFO_DEV_MIDI		2
#define SNDRV_OSS_INFO_DEV_TIMERS	4
#define SNDRV_OSS_INFO_DEV_MIXERS	5

#define SNDRV_OSS_INFO_DEV_COUNT	6

int snd_oss_info_register(int dev, int num, char *string);
#define snd_oss_info_unregister(dev, num) snd_oss_info_register(dev, num, NULL)

#endif /* CONFIG_SND_OSSEMUL && CONFIG_SND_PROC_FS */

#endif /* __SOUND_INFO_H */