ALSA: Add jack reporting API

Currently very few systems provide information about jack status to user
space, even though many have hardware facilities to do detection. Those
systems that do use an input device with the existing SW_HEADPHONE_INSERT
switch type to do so, often independently of ALSA.

This patch introduces a standard method for representing jacks to user
space into ALSA. It allows drivers to register jacks for a sound card with
the input subsystem, binding the input device to the card to help user
space associate the input devices with their sound cards. The created
input devices are named in the form "card longname jack" where jack is
provided by the driver when allocating a jack. By default the parent for
the input device is the sound card but this can be overridden by the
card driver.

The existing user space API with SW_HEADPHONE_INSERT is preserved.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

2 files changed, 76 insertions, 0 deletions

diff --git a/include/sound/core.h b/include/sound/core.h
index 558b962..1a4ff0b 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -63,6 +63,7 @@ typedef int __bitwise snd_device_type_t;
 #define	SNDRV_DEV_INFO		((__force snd_device_type_t) 0x1006)
 #define	SNDRV_DEV_BUS		((__force snd_device_type_t) 0x1007)
 #define	SNDRV_DEV_CODEC		((__force snd_device_type_t) 0x1008)
+#define	SNDRV_DEV_JACK          ((__force snd_device_type_t) 0x1009)
 #define	SNDRV_DEV_LOWLEVEL	((__force snd_device_type_t) 0x2000)
 
 typedef int __bitwise snd_device_state_t;
diff --git a/include/sound/jack.h b/include/sound/jack.h
new file mode 100644
index 0000000..b1b2b8b
--- /dev/null
+++ b/include/sound/jack.h
@@ -0,0 +1,75 @@
+#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.
+ */
+enum snd_jack_types {
+	SND_JACK_HEADPHONE	= 0x0001,
+	SND_JACK_MICROPHONE	= 0x0002,
+	SND_JACK_HEADSET	= SND_JACK_HEADPHONE | SND_JACK_MICROPHONE,
+};
+
+struct snd_jack {
+	struct input_dev *input_dev;
+	int registered;
+	int type;
+	const char *id;
+	char name[100];
+};
+
+#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);
+
+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