kernel-ark/include/sound/jack.h
Mark Brown ebb812cb8d ALSA: Add support for key reporting via the jack interface
Some devices provide support for detection of a small number of
buttons on their jacks. One common implementation provides a single
button, implemented by shorting the microphone to ground and detected
along with microphone presence detection by detecting varying current
draws on the microphone bias signal.

Provide support for up to three buttons via the jack interface. These
default to reporting BTN_n but an API is provided to allow these to
be remapped to other keys by the machine driver where it knows what
the keys are. More keys can be added with ease if required.

This is only intended to support simple accessory button designs. If
the interface is limiting then either creating a child device for the
accessory or accessing the input device in the jack directly is
recommended.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-03-17 18:10:46 +00:00

93 lines
2.4 KiB
C

#ifndef __SOUND_JACK_H
#define __SOUND_JACK_H
/*
* Jack abstraction layer
*
* Copyright 2008 Wolfson Microelectronics plc
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sound/core.h>
struct input_dev;
/**
* Jack types which can be reported. These values are used as a
* bitmask.
*
* Note that this must be kept in sync with the lookup table in
* sound/core/jack.c.
*/
enum snd_jack_types {
SND_JACK_HEADPHONE = 0x0001,
SND_JACK_MICROPHONE = 0x0002,
SND_JACK_HEADSET = SND_JACK_HEADPHONE | SND_JACK_MICROPHONE,
SND_JACK_LINEOUT = 0x0004,
SND_JACK_MECHANICAL = 0x0008, /* If detected separately */
SND_JACK_VIDEOOUT = 0x0010,
SND_JACK_AVOUT = SND_JACK_LINEOUT | SND_JACK_VIDEOOUT,
/* Kept separate from switches to facilitate implementation */
SND_JACK_BTN_0 = 0x4000,
SND_JACK_BTN_1 = 0x2000,
SND_JACK_BTN_2 = 0x1000,
};
struct snd_jack {
struct input_dev *input_dev;
int registered;
int type;
const char *id;
char name[100];
unsigned int key[3]; /* Keep in sync with definitions above */
void *private_data;
void (*private_free)(struct snd_jack *);
};
#ifdef CONFIG_SND_JACK
int snd_jack_new(struct snd_card *card, const char *id, int type,
struct snd_jack **jack);
void snd_jack_set_parent(struct snd_jack *jack, struct device *parent);
int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
int keytype);
void snd_jack_report(struct snd_jack *jack, int status);
#else
static inline int snd_jack_new(struct snd_card *card, const char *id, int type,
struct snd_jack **jack)
{
return 0;
}
static inline void snd_jack_set_parent(struct snd_jack *jack,
struct device *parent)
{
}
static inline void snd_jack_report(struct snd_jack *jack, int status)
{
}
#endif
#endif