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authorMark Brown <broonie@opensource.wolfsonmicro.com>2010-03-17 18:07:12 +0000
committerMark Brown <broonie@opensource.wolfsonmicro.com>2010-03-17 18:10:46 +0000
commitebb812cb8df48e299b3d4ab75cbb0042384ef70d (patch)
tree186de489bb17366d66eb5fb4123501ccbcbd8bbc /include
parent1c6e555c3a66af29a51690748ca54314e62c16d5 (diff)
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>
Diffstat (limited to 'include')
-rw-r--r--include/sound/jack.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/sound/jack.h b/include/sound/jack.h
index f236e426a70..d90b9fa3270 100644
--- a/include/sound/jack.h
+++ b/include/sound/jack.h
@@ -42,6 +42,11 @@ enum snd_jack_types {
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 {
@@ -50,6 +55,7 @@ struct snd_jack {
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 *);
};
@@ -59,6 +65,8 @@ struct 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);