ALSA: jack: implement kctl creating for jack devices

Currently the ALSA jack core registers only input devices for each jack
registered. These jack input devices are not readable by userspace devices
that run as non root. This patch series will implement kctls inside the
core jack part, including kctls creating, status changing report, for both
HD-Audio and ASoC jack. This allows non root userspace to read jack status
and act on it.

This patch adds a new API called snd_jack_add_new_kctl(), which will create
a kcontrol, add it to the card, and also attach it to the jack kctl list.

This patch also initialises the jack kctl list after jack is newed, and
reports kctl status when jack insertion/removal events occur.

snd_jack_new() is updated in the following patches to also support creating
phantom jacks and jack kcontrols. We then remove these duplicated features
from HDA jack and have jack kctls handled by core throughout HDA and ASoC.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Modified-by: Jie Yang <yang.jie@intel.com>
Signed-off-by: Jie Yang <yang.jie@intel.com>
Reveiwed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 93 insertions, 0 deletions

diff --git a/sound/core/jack.c b/sound/core/jack.c
index 8658578eb584..db69ecc23651 100644
--- a/sound/core/jack.c
+++ b/sound/core/jack.c
@@ -24,6 +24,13 @@
 #include <linux/module.h>
 #include <sound/jack.h>
 #include <sound/core.h>
+#include <sound/control.h>
+
+struct snd_jack_kctl {
+	struct snd_kcontrol *kctl;
+	struct list_head list;  /* list of controls belong to the same jack */
+	unsigned int mask_bits; /* only masked status bits are reported via kctl */
+};
 
 static int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
 	SW_HEADPHONE_INSERT,
@@ -54,7 +61,13 @@ static int snd_jack_dev_disconnect(struct snd_device *device)
 static int snd_jack_dev_free(struct snd_device *device)
 {
 	struct snd_jack *jack = device->device_data;
+	struct snd_card *card = device->card;
+	struct snd_jack_kctl *jack_kctl, *tmp_jack_kctl;
 
+	list_for_each_entry_safe(jack_kctl, tmp_jack_kctl, &jack->kctl_list, list) {
+		list_del_init(&jack_kctl->list);
+		snd_ctl_remove(card, jack_kctl->kctl);
+	}
 	if (jack->private_free)
 		jack->private_free(jack);
 
@@ -100,6 +113,77 @@ static int snd_jack_dev_register(struct snd_device *device)
 	return err;
 }
 
+static void snd_jack_kctl_private_free(struct snd_kcontrol *kctl)
+{
+	struct snd_jack_kctl *jack_kctl;
+
+	jack_kctl = kctl->private_data;
+	if (jack_kctl) {
+		list_del(&jack_kctl->list);
+		kfree(jack_kctl);
+	}
+}
+
+static void snd_jack_kctl_add(struct snd_jack *jack, struct snd_jack_kctl *jack_kctl)
+{
+	list_add_tail(&jack_kctl->list, &jack->kctl_list);
+}
+
+static struct snd_jack_kctl * snd_jack_kctl_new(struct snd_card *card, const char *name, unsigned int mask)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_jack_kctl *jack_kctl;
+	int err;
+
+	kctl = snd_kctl_jack_new(name, 0, card);
+	if (!kctl)
+		return NULL;
+
+	err = snd_ctl_add(card, kctl);
+	if (err < 0)
+		return NULL;
+
+	jack_kctl = kzalloc(sizeof(*jack_kctl), GFP_KERNEL);
+
+	if (!jack_kctl)
+		goto error;
+
+	jack_kctl->kctl = kctl;
+	jack_kctl->mask_bits = mask;
+
+	kctl->private_data = jack_kctl;
+	kctl->private_free = snd_jack_kctl_private_free;
+
+	return jack_kctl;
+error:
+	snd_ctl_free_one(kctl);
+	return NULL;
+}
+
+/**
+ * snd_jack_add_new_kctl - Create a new snd_jack_kctl and add it to jack
+ * @jack:  the jack instance which the kctl will attaching to
+ * @name:  the name for the snd_kcontrol object
+ * @mask:  a bitmask of enum snd_jack_type values that can be detected
+ *         by this snd_jack_kctl object.
+ *
+ * Creates a new snd_kcontrol object and adds it to the jack kctl_list.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_jack_add_new_kctl(struct snd_jack *jack, const char * name, int mask)
+{
+	struct snd_jack_kctl *jack_kctl;
+
+	jack_kctl = snd_jack_kctl_new(jack->card, name, mask);
+	if (!jack_kctl)
+		return -ENOMEM;
+
+	snd_jack_kctl_add(jack, jack_kctl);
+	return 0;
+}
+EXPORT_SYMBOL(snd_jack_add_new_kctl);
+
 /**
  * snd_jack_new - Create a new jack
  * @card:  the card instance
@@ -150,6 +234,9 @@ int snd_jack_new(struct snd_card *card, const char *id, int type,
 	if (err < 0)
 		goto fail_input;
 
+	jack->card = card;
+	INIT_LIST_HEAD(&jack->kctl_list);
+
 	*jjack = jack;
 
 	return 0;
@@ -230,6 +317,7 @@ EXPORT_SYMBOL(snd_jack_set_key);
  */
 void snd_jack_report(struct snd_jack *jack, int status)
 {
+	struct snd_jack_kctl *jack_kctl;
 	int i;
 
 	if (!jack)
@@ -252,6 +340,11 @@ void snd_jack_report(struct snd_jack *jack, int status)
 	}
 
 	input_sync(jack->input_dev);
+
+	list_for_each_entry(jack_kctl, &jack->kctl_list, list)
+		snd_kctl_jack_report(jack->card, jack_kctl->kctl,
+					    status & jack_kctl->mask_bits);
+
 }
 EXPORT_SYMBOL(snd_jack_report);