[linux-block.git] / include / sound / control.h

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

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

#include <linux/wait.h>
#include <linux/nospec.h>
#include <sound/asound.h>

#define snd_kcontrol_chip(kcontrol) ((kcontrol)->private_data)

struct snd_kcontrol;
typedef int (snd_kcontrol_info_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo);
typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
typedef int (snd_kcontrol_put_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
typedef int (snd_kcontrol_tlv_rw_t)(struct snd_kcontrol *kcontrol,
				    int op_flag, /* SNDRV_CTL_TLV_OP_XXX */
				    unsigned int size,
				    unsigned int __user *tlv);

/* internal flag for skipping validations */
#ifdef CONFIG_SND_CTL_DEBUG
#define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK	(1 << 24)
#define snd_ctl_skip_validation(info) \
	((info)->access & SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK)
#else
#define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK	0
#define snd_ctl_skip_validation(info)		true
#endif

/* kernel only - LED bits */
#define SNDRV_CTL_ELEM_ACCESS_LED_SHIFT		25
#define SNDRV_CTL_ELEM_ACCESS_LED_MASK		(7<<25) /* kernel three bits - LED group */
#define SNDRV_CTL_ELEM_ACCESS_SPK_LED		(1<<25) /* kernel speaker (output) LED flag */
#define SNDRV_CTL_ELEM_ACCESS_MIC_LED		(2<<25) /* kernel microphone (input) LED flag */

enum {
	SNDRV_CTL_TLV_OP_READ = 0,
	SNDRV_CTL_TLV_OP_WRITE = 1,
	SNDRV_CTL_TLV_OP_CMD = -1,
};

struct snd_kcontrol_new {
	snd_ctl_elem_iface_t iface;	/* interface identifier */
	unsigned int device;		/* device/client number */
	unsigned int subdevice;		/* subdevice (substream) number */
	const char *name;		/* ASCII name of item */
	unsigned int index;		/* index of item */
	unsigned int access;		/* access rights */
	unsigned int count;		/* count of same elements */
	snd_kcontrol_info_t *info;
	snd_kcontrol_get_t *get;
	snd_kcontrol_put_t *put;
	union {
		snd_kcontrol_tlv_rw_t *c;
		const unsigned int *p;
	} tlv;
	unsigned long private_value;
};

struct snd_kcontrol_volatile {
	struct snd_ctl_file *owner;	/* locked */
	unsigned int access;	/* access rights */
};

struct snd_kcontrol {
	struct list_head list;		/* list of controls */
	struct snd_ctl_elem_id id;
	unsigned int count;		/* count of same elements */
	snd_kcontrol_info_t *info;
	snd_kcontrol_get_t *get;
	snd_kcontrol_put_t *put;
	union {
		snd_kcontrol_tlv_rw_t *c;
		const unsigned int *p;
	} tlv;
	unsigned long private_value;
	void *private_data;
	void (*private_free)(struct snd_kcontrol *kcontrol);
	struct snd_kcontrol_volatile vd[];	/* volatile data */
};

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

struct snd_kctl_event {
	struct list_head list;	/* list of events */
	struct snd_ctl_elem_id id;
	unsigned int mask;
};

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

struct pid;

enum {
	SND_CTL_SUBDEV_PCM,
	SND_CTL_SUBDEV_RAWMIDI,
	SND_CTL_SUBDEV_ITEMS,
};

struct snd_ctl_file {
	struct list_head list;		/* list of all control files */
	struct snd_card *card;
	struct pid *pid;
	int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
	wait_queue_head_t change_sleep;
	spinlock_t read_lock;
	struct snd_fasync *fasync;
	int subscribed;			/* read interface is activated */
	struct list_head events;	/* waiting events for read */
};

struct snd_ctl_layer_ops {
	struct snd_ctl_layer_ops *next;
	const char *module_name;
	void (*lregister)(struct snd_card *card);
	void (*ldisconnect)(struct snd_card *card);
	void (*lnotify)(struct snd_card *card, unsigned int mask, struct snd_kcontrol *kctl, unsigned int ioff);
};

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

typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
				      struct snd_ctl_file * control,
				      unsigned int cmd, unsigned long arg);

void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kcontrol * kctl, unsigned int ioff);

struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active);
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);

int snd_ctl_create(struct snd_card *card);

int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
#ifdef CONFIG_COMPAT
int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
#else
#define snd_ctl_register_ioctl_compat(fcn)
#define snd_ctl_unregister_ioctl_compat(fcn)
#endif

int snd_ctl_request_layer(const char *module_name);
void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);

int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);

static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
{
	unsigned int ioff = id->numid - kctl->id.numid;
	return array_index_nospec(ioff, kctl->count);
}

static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
{
	unsigned int ioff = id->index - kctl->id.index;
	return array_index_nospec(ioff, kctl->count);
}

static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
{
	if (id->numid) {
		return snd_ctl_get_ioffnum(kctl, id);
	} else {
		return snd_ctl_get_ioffidx(kctl, id);
	}
}

static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id *dst_id,
						    struct snd_kcontrol *src_kctl,
						    unsigned int offset)
{
	*dst_id = src_kctl->id;
	dst_id->index += offset;
	dst_id->numid += offset;
	return dst_id;
}

/*
 * Frequently used control callbacks/helpers
 */
int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
			      struct snd_ctl_elem_info *uinfo);
int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
				struct snd_ctl_elem_info *uinfo);
int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
		      unsigned int items, const char *const names[]);

/*
 * virtual master control
 */
struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
						 const unsigned int *tlv);
int _snd_ctl_add_follower(struct snd_kcontrol *master,
			  struct snd_kcontrol *follower,
			  unsigned int flags);
/* optional flags for follower */
#define SND_CTL_FOLLOWER_NEED_UPDATE	(1 << 0)

/**
 * snd_ctl_add_follower - Add a virtual follower control
 * @master: vmaster element
 * @follower: follower element to add
 *
 * Add a virtual follower control to the given master element created via
 * snd_ctl_create_virtual_master() beforehand.
 *
 * All followers must be the same type (returning the same information
 * via info callback).  The function doesn't check it, so it's your
 * responsibility.
 *
 * Also, some additional limitations:
 * at most two channels,
 * logarithmic volume control (dB level) thus no linear volume,
 * master can only attenuate the volume without gain
 *
 * Return: Zero if successful or a negative error code.
 */
static inline int
snd_ctl_add_follower(struct snd_kcontrol *master, struct snd_kcontrol *follower)
{
	return _snd_ctl_add_follower(master, follower, 0);
}

/**
 * snd_ctl_add_follower_uncached - Add a virtual follower control
 * @master: vmaster element
 * @follower: follower element to add
 *
 * Add a virtual follower control to the given master.
 * Unlike snd_ctl_add_follower(), the element added via this function
 * is supposed to have volatile values, and get callback is called
 * at each time queried from the master.
 *
 * When the control peeks the hardware values directly and the value
 * can be changed by other means than the put callback of the element,
 * this function should be used to keep the value always up-to-date.
 *
 * Return: Zero if successful or a negative error code.
 */
static inline int
snd_ctl_add_follower_uncached(struct snd_kcontrol *master,
			      struct snd_kcontrol *follower)
{
	return _snd_ctl_add_follower(master, follower, SND_CTL_FOLLOWER_NEED_UPDATE);
}

int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
			     void (*hook)(void *private_data, int),
			     void *private_data);
void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
#define snd_ctl_sync_vmaster_hook(kctl)	snd_ctl_sync_vmaster(kctl, true)
int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
				    int (*func)(struct snd_kcontrol *vfollower,
						struct snd_kcontrol *follower,
						void *arg),
				    void *arg);

/*
 * Control LED trigger layer
 */
#define SND_CTL_LAYER_MODULE_LED	"snd-ctl-led"

#if IS_MODULE(CONFIG_SND_CTL_LED)
static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
#else
static inline int snd_ctl_led_request(void) { return 0; }
#endif

/*
 * Helper functions for jack-detection controls
 */
struct snd_kcontrol *
snd_kctl_jack_new(const char *name, struct snd_card *card);
void snd_kctl_jack_report(struct snd_card *card,
			  struct snd_kcontrol *kctl, bool status);

#endif	/* __SOUND_CONTROL_H */
Commit	Line	Data
1a59d1b8	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
1da177e4 LT	2	#ifndef __SOUND_CONTROL_H
	3	#define __SOUND_CONTROL_H
	4
	5	/*
	6	* Header file for control interface
c1017a4c	7	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
1da177e4 LT	8	*/
1da177e4 LT	9
b69339ba	10	#include <linux/wait.h>
088e861e	11	#include <linux/nospec.h>
1da177e4 LT	12	#include <sound/asound.h>
1da177e4 LT	13
1da177e4 LT	14	#define snd_kcontrol_chip(kcontrol) ((kcontrol)->private_data)
1da177e4 LT	15
82e9bae6 TI	16	struct snd_kcontrol;
	17	typedef int (snd_kcontrol_info_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo);
	18	typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
	19	typedef int (snd_kcontrol_put_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
8aa9b586	20	typedef int (snd_kcontrol_tlv_rw_t)(struct snd_kcontrol *kcontrol,
0cea76f3	21	int op_flag, /* SNDRV_CTL_TLV_OP_XXX */
8aa9b586 JK	22	unsigned int size,
	23	unsigned int __user *tlv);
	24
fbd3eb7f	25	/* internal flag for skipping validations */
1b7ec514	26	#ifdef CONFIG_SND_CTL_DEBUG
22d8de62	27	#define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK (1 << 24)
fbd3eb7f TI	28	#define snd_ctl_skip_validation(info) \
	29	((info)->access & SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK)
	30	#else
	31	#define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK 0
	32	#define snd_ctl_skip_validation(info) true
	33	#endif
	34
22d8de62 JK	35	/* kernel only - LED bits */
	36	#define SNDRV_CTL_ELEM_ACCESS_LED_SHIFT 25
	37	#define SNDRV_CTL_ELEM_ACCESS_LED_MASK (7<<25) /* kernel three bits - LED group */
	38	#define SNDRV_CTL_ELEM_ACCESS_SPK_LED (1<<25) /* kernel speaker (output) LED flag */
	39	#define SNDRV_CTL_ELEM_ACCESS_MIC_LED (2<<25) /* kernel microphone (input) LED flag */
	40
0cea76f3 TI	41	enum {
	42	SNDRV_CTL_TLV_OP_READ = 0,
	43	SNDRV_CTL_TLV_OP_WRITE = 1,
	44	SNDRV_CTL_TLV_OP_CMD = -1,
	45	};
1da177e4	46
82e9bae6	47	struct snd_kcontrol_new {
1da177e4 LT	48	snd_ctl_elem_iface_t iface; /* interface identifier */
	49	unsigned int device; /* device/client number */
	50	unsigned int subdevice; /* subdevice (substream) number */
2a6eca16	51	const char name; / ASCII name of item */
1da177e4 LT	52	unsigned int index; /* index of item */
	53	unsigned int access; /* access rights */
	54	unsigned int count; /* count of same elements */
	55	snd_kcontrol_info_t *info;
	56	snd_kcontrol_get_t *get;
	57	snd_kcontrol_put_t *put;
8aa9b586 JK	58	union {
8aa9b586 JK	59	snd_kcontrol_tlv_rw_t *c;
0cb29ea0	60	const unsigned int *p;
8aa9b586	61	} tlv;
1da177e4	62	unsigned long private_value;
82e9bae6	63	};
1da177e4	64
82e9bae6 TI	65	struct snd_kcontrol_volatile {
82e9bae6 TI	66	struct snd_ctl_file owner; / locked */
1da177e4	67	unsigned int access; /* access rights */
82e9bae6	68	};
1da177e4	69
82e9bae6	70	struct snd_kcontrol {
1da177e4	71	struct list_head list; /* list of controls */
82e9bae6	72	struct snd_ctl_elem_id id;
1da177e4 LT	73	unsigned int count; /* count of same elements */
	74	snd_kcontrol_info_t *info;
	75	snd_kcontrol_get_t *get;
	76	snd_kcontrol_put_t *put;
8aa9b586 JK	77	union {
8aa9b586 JK	78	snd_kcontrol_tlv_rw_t *c;
0cb29ea0	79	const unsigned int *p;
8aa9b586	80	} tlv;
1da177e4 LT	81	unsigned long private_value;
1da177e4 LT	82	void *private_data;
82e9bae6	83	void (private_free)(struct snd_kcontrol kcontrol);
9ad06ebb	84	struct snd_kcontrol_volatile vd[]; /* volatile data */
1da177e4 LT	85	};
1da177e4 LT	86
82e9bae6	87	#define snd_kcontrol(n) list_entry(n, struct snd_kcontrol, list)
1da177e4	88
82e9bae6	89	struct snd_kctl_event {
1da177e4	90	struct list_head list; /* list of events */
82e9bae6	91	struct snd_ctl_elem_id id;
1da177e4	92	unsigned int mask;
82e9bae6	93	};
1da177e4	94
82e9bae6	95	#define snd_kctl_event(n) list_entry(n, struct snd_kctl_event, list)
1da177e4	96
25d27ede CL	97	struct pid;
25d27ede CL	98
23c18d4b TI	99	enum {
	100	SND_CTL_SUBDEV_PCM,
	101	SND_CTL_SUBDEV_RAWMIDI,
	102	SND_CTL_SUBDEV_ITEMS,
	103	};
	104
82e9bae6	105	struct snd_ctl_file {
1da177e4	106	struct list_head list; /* list of all control files */
82e9bae6	107	struct snd_card *card;
25d27ede	108	struct pid *pid;
23c18d4b	109	int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
1da177e4 LT	110	wait_queue_head_t change_sleep;
1da177e4 LT	111	spinlock_t read_lock;
4a971e84	112	struct snd_fasync *fasync;
1da177e4 LT	113	int subscribed; /* read interface is activated */
	114	struct list_head events; /* waiting events for read */
	115	};
	116
3f0638a0 JK	117	struct snd_ctl_layer_ops {
	118	struct snd_ctl_layer_ops *next;
	119	const char *module_name;
	120	void (lregister)(struct snd_card card);
	121	void (ldisconnect)(struct snd_card card);
	122	void (lnotify)(struct snd_card card, unsigned int mask, struct snd_kcontrol *kctl, unsigned int ioff);
	123	};
	124
82e9bae6	125	#define snd_ctl_file(n) list_entry(n, struct snd_ctl_file, list)
1da177e4	126
82e9bae6 TI	127	typedef int (snd_kctl_ioctl_func_t) (struct snd_card card,
	128	struct snd_ctl_file * control,
	129	unsigned int cmd, unsigned long arg);
1da177e4	130
82e9bae6	131	void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
1fa4445f	132	void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kcontrol * kctl, unsigned int ioff);
1da177e4	133
82e9bae6 TI	134	struct snd_kcontrol snd_ctl_new1(const struct snd_kcontrol_new kcontrolnew, void * private_data);
	135	void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
	136	int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
	137	int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
66b5b972	138	int snd_ctl_replace(struct snd_card card, struct snd_kcontrol kcontrol, bool add_on_replace);
82e9bae6 TI	139	int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
82e9bae6 TI	140	int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id src_id, struct snd_ctl_elem_id dst_id);
1fa4445f	141	int snd_ctl_activate_id(struct snd_card card, struct snd_ctl_elem_id id, int active);
82e9bae6 TI	142	struct snd_kcontrol snd_ctl_find_numid(struct snd_card card, unsigned int numid);
82e9bae6 TI	143	struct snd_kcontrol snd_ctl_find_id(struct snd_card card, struct snd_ctl_elem_id *id);
1da177e4	144
82e9bae6	145	int snd_ctl_create(struct snd_card *card);
1da177e4 LT	146
	147	int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
	148	int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
	149	#ifdef CONFIG_COMPAT
	150	int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
	151	int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
	152	#else
	153	#define snd_ctl_register_ioctl_compat(fcn)
	154	#define snd_ctl_unregister_ioctl_compat(fcn)
	155	#endif
	156
3f0638a0 JK	157	int snd_ctl_request_layer(const char *module_name);
	158	void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
	159	void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);
	160
23c18d4b TI	161	int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
23c18d4b TI	162
82e9bae6	163	static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol kctl, struct snd_ctl_elem_id id)
1da177e4	164	{
088e861e TI	165	unsigned int ioff = id->numid - kctl->id.numid;
088e861e TI	166	return array_index_nospec(ioff, kctl->count);
1da177e4 LT	167	}
1da177e4 LT	168
82e9bae6	169	static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol kctl, struct snd_ctl_elem_id id)
1da177e4	170	{
088e861e TI	171	unsigned int ioff = id->index - kctl->id.index;
088e861e TI	172	return array_index_nospec(ioff, kctl->count);
1da177e4 LT	173	}
1da177e4 LT	174
82e9bae6	175	static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol kctl, struct snd_ctl_elem_id id)
1da177e4 LT	176	{
	177	if (id->numid) {
	178	return snd_ctl_get_ioffnum(kctl, id);
	179	} else {
	180	return snd_ctl_get_ioffidx(kctl, id);
	181	}
	182	}
	183
82e9bae6 TI	184	static inline struct snd_ctl_elem_id snd_ctl_build_ioff(struct snd_ctl_elem_id dst_id,
82e9bae6 TI	185	struct snd_kcontrol *src_kctl,
1da177e4 LT	186	unsigned int offset)
	187	{
	188	*dst_id = src_kctl->id;
	189	dst_id->index += offset;
	190	dst_id->numid += offset;
	191	return dst_id;
	192	}
	193
b9ed4f2b	194	/*
9600732b	195	* Frequently used control callbacks/helpers
b9ed4f2b TI	196	*/
	197	int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
	198	struct snd_ctl_elem_info *uinfo);
	199	int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
	200	struct snd_ctl_elem_info *uinfo);
9600732b CL	201	int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
9600732b CL	202	unsigned int items, const char *const names[]);
b9ed4f2b	203
e922b002 TI	204	/*
	205	* virtual master control
	206	*/
	207	struct snd_kcontrol snd_ctl_make_virtual_master(char name,
	208	const unsigned int *tlv);
9ab0cb30 TI	209	int _snd_ctl_add_follower(struct snd_kcontrol *master,
	210	struct snd_kcontrol *follower,
	211	unsigned int flags);
	212	/* optional flags for follower */
	213	#define SND_CTL_FOLLOWER_NEED_UPDATE (1 << 0)
f5b1db63	214
79c7cdd5	215	/**
9ab0cb30	216	* snd_ctl_add_follower - Add a virtual follower control
79c7cdd5	217	* @master: vmaster element
9ab0cb30	218	* @follower: follower element to add
79c7cdd5	219	*
9ab0cb30	220	* Add a virtual follower control to the given master element created via
79c7cdd5	221	* snd_ctl_create_virtual_master() beforehand.
79c7cdd5	222	*
9ab0cb30	223	* All followers must be the same type (returning the same information
25985edc	224	* via info callback). The function doesn't check it, so it's your
79c7cdd5 TI	225	* responsibility.
	226	*
	227	* Also, some additional limitations:
	228	* at most two channels,
	229	* logarithmic volume control (dB level) thus no linear volume,
	230	* master can only attenuate the volume without gain
eb7c06e8 YB	231	*
eb7c06e8 YB	232	* Return: Zero if successful or a negative error code.
79c7cdd5	233	*/
f5b1db63	234	static inline int
9ab0cb30	235	snd_ctl_add_follower(struct snd_kcontrol master, struct snd_kcontrol follower)
f5b1db63	236	{
9ab0cb30	237	return _snd_ctl_add_follower(master, follower, 0);
f5b1db63 TI	238	}
f5b1db63 TI	239
79c7cdd5	240	/**
9ab0cb30	241	* snd_ctl_add_follower_uncached - Add a virtual follower control
79c7cdd5	242	* @master: vmaster element
9ab0cb30	243	* @follower: follower element to add
79c7cdd5	244	*
9ab0cb30 TI	245	* Add a virtual follower control to the given master.
9ab0cb30 TI	246	* Unlike snd_ctl_add_follower(), the element added via this function
79c7cdd5	247	* is supposed to have volatile values, and get callback is called
1a6ab46f	248	* at each time queried from the master.
79c7cdd5 TI	249	*
	250	* When the control peeks the hardware values directly and the value
	251	* can be changed by other means than the put callback of the element,
	252	* this function should be used to keep the value always up-to-date.
eb7c06e8 YB	253	*
eb7c06e8 YB	254	* Return: Zero if successful or a negative error code.
79c7cdd5	255	*/
f5b1db63	256	static inline int
9ab0cb30 TI	257	snd_ctl_add_follower_uncached(struct snd_kcontrol *master,
9ab0cb30 TI	258	struct snd_kcontrol *follower)
f5b1db63	259	{
9ab0cb30	260	return _snd_ctl_add_follower(master, follower, SND_CTL_FOLLOWER_NEED_UPDATE);
f5b1db63 TI	261	}
f5b1db63 TI	262
2ad787e9 TI	263	int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
	264	void (hook)(void private_data, int),
	265	void *private_data);
1ca2f2ec TI	266	void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
1ca2f2ec TI	267	#define snd_ctl_sync_vmaster_hook(kctl) snd_ctl_sync_vmaster(kctl, true)
9ab0cb30 TI	268	int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
	269	int (func)(struct snd_kcontrol vfollower,
	270	struct snd_kcontrol *follower,
	271	void *arg),
	272	void *arg);
2ad787e9	273
22d8de62 JK	274	/*
	275	* Control LED trigger layer
	276	*/
	277	#define SND_CTL_LAYER_MODULE_LED "snd-ctl-led"
	278
	279	#if IS_MODULE(CONFIG_SND_CTL_LED)
	280	static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
	281	#else
	282	static inline int snd_ctl_led_request(void) { return 0; }
	283	#endif
	284
35be544a TI	285	/*
	286	* Helper functions for jack-detection controls
	287	*/
	288	struct snd_kcontrol *
2ba2dfa1	289	snd_kctl_jack_new(const char name, struct snd_card card);
35be544a TI	290	void snd_kctl_jack_report(struct snd_card *card,
	291	struct snd_kcontrol *kctl, bool status);
	292
1da177e4	293	#endif /* __SOUND_CONTROL_H */