External Control Plugin SDK

Files
file	control_ext.c
	External Control Plugin SDK.

Data Structures
struct	snd_ctl_ext_t
struct	snd_ctl_ext_callback_t

Macros
#define	SND_CTL_PLUGIN_ENTRY(name)
#define	SND_CTL_PLUGIN_SYMBOL(name)
#define	SND_CTL_PLUGIN_DEFINE_FUNC(plugin)
#define	SND_CTL_EXT_VERSION_MAJOR   1
#define	SND_CTL_EXT_VERSION_MINOR   0
#define	SND_CTL_EXT_VERSION_TINY   1
#define	SND_CTL_EXT_VERSION
#define	SND_CTL_EXT_KEY_NOT_FOUND   (snd_ctl_ext_key_t)(-1)

Typedefs
typedef unsigned long	snd_ctl_ext_key_t
typedef snd_ctl_ext	snd_ctl_ext_t
typedef snd_ctl_ext_callback	snd_ctl_ext_callback_t
typedef int	snd_ctl_ext_tlv_rw_t(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, int op_flag, unsigned int numid, unsigned int *tlv, unsigned int tlv_size)

Enumerations
enum	snd_ctl_ext_access_t {   SND_CTL_EXT_ACCESS_READ = (1<<0) , SND_CTL_EXT_ACCESS_WRITE = (1<<1) , SND_CTL_EXT_ACCESS_READWRITE = (3<<0) , SND_CTL_EXT_ACCESS_VOLATILE = (1<<2) ,   SND_CTL_EXT_ACCESS_TLV_READ = (1<<4) , SND_CTL_EXT_ACCESS_TLV_WRITE = (1<<5) , SND_CTL_EXT_ACCESS_TLV_READWRITE = (3<<4) , SND_CTL_EXT_ACCESS_TLV_COMMAND = (1<<6) ,   SND_CTL_EXT_ACCESS_INACTIVE = (1<<8) , SND_CTL_EXT_ACCESS_TLV_CALLBACK = (1<<28) }

Functions
int	snd_ctl_ext_create (snd_ctl_ext_t *ext, const char *name, int mode)
	Create an external control plugin instance.
int	snd_ctl_ext_delete (snd_ctl_ext_t *ext)
	Delete the external control plugin.

Detailed Description

Macro Definition Documentation

SND_CTL_EXT_KEY_NOT_FOUND

#define SND_CTL_EXT_KEY_NOT_FOUND   (snd_ctl_ext_key_t)(-1)

find_elem callback returns this if no matching control element is found

SND_CTL_EXT_VERSION

#define SND_CTL_EXT_VERSION

Value:

                     ((SND_CTL_EXT_VERSION_MAJOR<<16) |\
                     (SND_CTL_EXT_VERSION_MINOR<<8) |\
                     (SND_CTL_EXT_VERSION_TINY))

external plugin protocol version

SND_CTL_EXT_VERSION_MAJOR

#define SND_CTL_EXT_VERSION_MAJOR   1

Protocol major version

SND_CTL_EXT_VERSION_MINOR

#define SND_CTL_EXT_VERSION_MINOR   0

Protocol minor version

SND_CTL_EXT_VERSION_TINY

#define SND_CTL_EXT_VERSION_TINY   1

Protocol tiny version

SND_CTL_PLUGIN_DEFINE_FUNC

#define SND_CTL_PLUGIN_DEFINE_FUNC

(

plugin

)

Value:

int SND_CTL_PLUGIN_ENTRY(plugin) (snd_ctl_t **handlep, const char *name,\
                  snd_config_t *root, snd_config_t *conf, int mode)

Define the control plugin

SND_CTL_PLUGIN_ENTRY

#define SND_CTL_PLUGIN_ENTRY

(

name

)

Value:

_snd_ctl_##name##_open

Define the object entry for external control plugins

SND_CTL_PLUGIN_SYMBOL

#define SND_CTL_PLUGIN_SYMBOL

(

name

)

Value:

SND_DLSYM_BUILD_VERSION(SND_CTL_PLUGIN_ENTRY(name), SND_CONTROL_DLSYM_VERSION);

Define the symbols of the given control plugin with versions

Typedef Documentation

snd_ctl_ext_callback_t

typedef struct snd_ctl_ext_callback snd_ctl_ext_callback_t

Callback table of control ext

snd_ctl_ext_key_t

typedef unsigned long snd_ctl_ext_key_t

Key to access a control pointer

snd_ctl_ext_t

typedef struct snd_ctl_ext snd_ctl_ext_t

External control plugin handle

snd_ctl_ext_tlv_rw_t

typedef int snd_ctl_ext_tlv_rw_t(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, int op_flag, unsigned int numid, unsigned int *tlv, unsigned int tlv_size)

Callback to handle TLV commands.

Enumeration Type Documentation

snd_ctl_ext_access_t

enum snd_ctl_ext_access_t

The access type bits stored in get_attribute callback

Function Documentation

snd_ctl_ext_create()

int snd_ctl_ext_create	(	snd_ctl_ext_t *	ext,
		const char *	name,
		int	mode )

Create an external control plugin instance.

Parameters

ext	the plugin handle
name	name of control
mode	control open mode

Returns

0 if successful, or a negative error code

Creates the external control instance.

snd_ctl_ext_delete()

int snd_ctl_ext_delete

(

snd_ctl_ext_t *

ext

)

Delete the external control plugin.

Parameters

ext	the plugin handle

Returns

0 if successful, or a negative error code