[PATCH v2 1/3] ALSA: Added jack detection kcontrol support

From: Felipe F. Tonello
Date: Fri Jul 26 2013 - 18:46:43 EST


From: "Felipe F. Tonello" <eu@xxxxxxxxxxxxxxxxx>

This patch adds jack support for alsa kcontrol.

This support is necessary since the new kcontrol is used by user-space
daemons, such as PulseAudio(>=2.0), to do jack detection.)

Signed-off-by: Felipe F. Tonello <eu@xxxxxxxxxxxxxxxxx>
---
include/sound/jack.h | 6 ++++--
sound/core/Kconfig | 1 +
sound/core/ctljack.c | 3 ++-
sound/core/jack.c | 29 +++++++++++++++++++++++++++--
4 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/include/sound/jack.h b/include/sound/jack.h
index 5891657..dc62b74 100644
--- a/include/sound/jack.h
+++ b/include/sound/jack.h
@@ -26,6 +26,7 @@
#include <sound/core.h>

struct input_dev;
+struct snd_kcontrol;

/**
* Jack types which can be reported. These values are used as a
@@ -58,6 +59,7 @@ enum snd_jack_types {

struct snd_jack {
struct input_dev *input_dev;
+ struct snd_kcontrol *kctl;
int registered;
int type;
const char *id;
@@ -70,7 +72,7 @@ struct snd_jack {
#ifdef CONFIG_SND_JACK

int snd_jack_new(struct snd_card *card, const char *id, int type,
- struct snd_jack **jack);
+ int idx, 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);
@@ -80,7 +82,7 @@ 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)
+ int idx, struct snd_jack **jack)
{
return 0;
}
diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index c0c2f57..8167615 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -20,6 +20,7 @@ config SND_COMPRESS_OFFLOAD
# to avoid having to force INPUT on.
config SND_JACK
bool
+ select SND_KCTL_JACK

config SND_SEQUENCER
tristate "Sequencer support"
diff --git a/sound/core/ctljack.c b/sound/core/ctljack.c
index e4b38fb..59aa6d0 100644
--- a/sound/core/ctljack.c
+++ b/sound/core/ctljack.c
@@ -38,7 +38,8 @@ snd_kctl_jack_new(const char *name, int idx, void *private_data)
kctl = snd_ctl_new1(&jack_detect_kctl, private_data);
if (!kctl)
return NULL;
- snprintf(kctl->id.name, sizeof(kctl->id.name), "%s Jack", name);
+
+ strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
kctl->id.index = idx;
kctl->private_value = 0;
return kctl;
diff --git a/sound/core/jack.c b/sound/core/jack.c
index b35fe73..b2757b1 100644
--- a/sound/core/jack.c
+++ b/sound/core/jack.c
@@ -24,6 +24,7 @@
#include <linux/module.h>
#include <sound/jack.h>
#include <sound/core.h>
+#include <sound/control.h>

static int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
SW_HEADPHONE_INSERT,
@@ -48,6 +49,7 @@ static int snd_jack_dev_free(struct snd_device *device)
else
input_free_device(jack->input_dev);

+ snd_ctl_remove(device->card, jack->kctl);
kfree(jack->id);
kfree(jack);

@@ -85,26 +87,36 @@ static int snd_jack_dev_register(struct snd_device *device)
if (err == 0)
jack->registered = 1;

+ /* We don't need to free the control, it's freed by snd_ctl_add itself
+ if an error occur */
+ err = snd_ctl_add(card, jack->kctl);
+
return err;
}

/**
* snd_jack_new - Create a new jack
* @card: the card instance
- * @id: an identifying string for this jack
+ * @id: an identifying string for this jack, " Jack" is appended to the
+ * string
* @type: a bitmask of enum snd_jack_type values that can be detected by
* this jack
+ * @idx: index of this control item
* @jjack: Used to provide the allocated jack object to the caller.
*
* Creates a new jack object.
*
+ * This function creates a Jack Kcontrol, which is exported to user space via
+ * ALSA Controls.
+ *
* Return: Zero if successful, or a negative error code on failure.
* On success @jjack will be initialised.
*/
int snd_jack_new(struct snd_card *card, const char *id, int type,
- struct snd_jack **jjack)
+ int idx, struct snd_jack **jjack)
{
struct snd_jack *jack;
+ struct snd_kcontrol *kctl;
int err;
int i;
static struct snd_device_ops ops = {
@@ -117,6 +129,7 @@ int snd_jack_new(struct snd_card *card, const char *id, int type,
return -ENOMEM;

jack->id = kstrdup(id, GFP_KERNEL);
+ sprintf((char *)jack->id, "%s Jack", jack->id);

jack->input_dev = input_allocate_device();
if (jack->input_dev == NULL) {
@@ -137,6 +150,15 @@ int snd_jack_new(struct snd_card *card, const char *id, int type,
if (err < 0)
goto fail_input;

+ /* card is the private_data */
+ kctl = snd_kctl_jack_new(jack->id, idx, card);
+ if (!kctl) {
+ err = -ENOMEM;
+ goto fail_input;
+ }
+
+ jack->kctl = kctl;
+
*jjack = jack;

return 0;
@@ -239,6 +261,9 @@ void snd_jack_report(struct snd_jack *jack, int status)
}

input_sync(jack->input_dev);
+
+ /* Update ALSA KControl interface */
+ snd_kctl_jack_report((struct snd_card *)jack->kctl->private_data, jack->kctl, !!status);
}
EXPORT_SYMBOL(snd_jack_report);

--
1.8.1.4

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