mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-10-29 05:40:25 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

control_external: Add ability to specify TLV data.

Browse source 
Allow external control plugins to provide TLV data.  This allows
user-space pcms to specify dB ranges for controls.

This follows the same model as the ALSA drivers for accessing the
data.  The code is based on that implementation.  The control can
provide static data or a callback.  The data is accessed or modified
in the new snd_ctl_ext_elem_tlv callback.

Rev bump the protocol version to enable checking if an external
control supports TLV.

Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Dylan Reid 2012-04-15 16:59:55 -07:00 • committed by Takashi Iwai
parent ed0e48583f
commit a6c50d64d9
2 changed files with 62 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

17
include/control_external.h
View file

@ -60,13 +60,16 @@ typedef struct snd_ctl_ext snd_ctl_ext_t;
typedef struct snd_ctl_ext_callback snd_ctl_ext_callback_t;
/** Key to access a control pointer */
typedef unsigned long snd_ctl_ext_key_t;
/** Callback to handle TLV commands. */
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);
/*
* Protocol version
*/
#define SND_CTL_EXT_VERSION_MAJOR 1 /**< Protocol major version */
#define SND_CTL_EXT_VERSION_MINOR 0 /**< Protocol minor version */
#define SND_CTL_EXT_VERSION_TINY 0 /**< Protocol tiny version */
#define SND_CTL_EXT_VERSION_TINY 1 /**< Protocol tiny version */
/**
* external plugin protocol version
*/
@ -122,6 +125,13 @@ struct snd_ctl_ext {
* control handle filled by #snd_ctl_ext_create()
*/
snd_ctl_t *handle;
/**
* optional TLV data for the control.
*/
union {
snd_ctl_ext_tlv_rw_t *c;
const unsigned int *p;
} tlv;
int nonblock; /**< non-block mode; read-only */
int subscribed; /**< events subscribed; read-only */
@ -245,7 +255,12 @@ typedef enum snd_ctl_ext_access {
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),
} snd_ctl_ext_access_t;
/**