From faa14323145eeb44e462dc6fbe423142dbf4ecef Mon Sep 17 00:00:00 2001
From: Ravindra Lokhande <rlokhande@nvidia.com>
Date: Fri, 27 Jul 2012 22:36:29 +0530
Subject: ALSA: usb-audio: register switch device

Register android switch device which is used to convey device plug-in
and plug-out to userspace.

Bug 1009921, Bug 1019877

Change-Id: I8e3c2fce420cc0ce094a6d8f2cf00abb630fcf2f
Reviewed-on: http://git-master/r/119033
Tested-by: Ravindra Lokhande <rlokhande@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Scott Peterson <speterson@nvidia.com>
Reviewed-by: Vijay Mali <vmali@nvidia.com>

Rebase-Id: Rae95c4dff968d5be2a3bce1b063c0af2ab653973
---
 sound/usb/card.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

(limited to 'sound')

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 64952e2d3ed1..e51538b668a9 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -32,7 +32,6 @@
  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
  */
 
-
 #include <linux/bitops.h>
 #include <linux/init.h>
 #include <linux/list.h>
@@ -45,6 +44,9 @@
 #include <linux/usb/audio.h>
 #include <linux/usb/audio-v2.h>
 #include <linux/module.h>
+#ifdef CONFIG_SWITCH
+#include <linux/switch.h>
+#endif
 
 #include <sound/control.h>
 #include <sound/core.h>
@@ -113,6 +115,18 @@ static DEFINE_MUTEX(register_mutex);
 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
 static struct usb_driver usb_audio_driver;
 
+#ifdef CONFIG_SWITCH
+enum switch_state {
+	STATE_CONNECTED_UNKNOWN = -1,
+	STATE_DISCONNECTED = 0,
+	STATE_CONNECTED = 1
+};
+
+static struct switch_dev usb_switch_dev = {
+	.name = "usb_audio",
+};
+#endif
+
 /*
  * disconnect streams
  * called from snd_usb_audio_disconnect()
@@ -558,10 +572,15 @@ snd_usb_audio_probe(struct usb_device *dev,
 		goto __error;
 	}
 
+#ifdef CONFIG_SWITCH
+	switch_set_state(&usb_switch_dev, STATE_CONNECTED);
+#endif
+
 	usb_chip[chip->index] = chip;
 	chip->num_interfaces++;
 	chip->probing = 0;
 	mutex_unlock(&register_mutex);
+
 	return chip;
 
  __error:
@@ -572,6 +591,7 @@ snd_usb_audio_probe(struct usb_device *dev,
 	}
 	mutex_unlock(&register_mutex);
  __err_val:
+
 	return NULL;
 }
 
@@ -595,6 +615,11 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
 
 	mutex_lock(&register_mutex);
 	chip->num_interfaces--;
+
+#ifdef CONFIG_SWITCH
+	switch_set_state(&usb_switch_dev, STATE_DISCONNECTED);
+#endif
+
 	if (chip->num_interfaces <= 0) {
 		snd_card_disconnect(card);
 		/* release the pcm resources */
@@ -756,15 +781,35 @@ static struct usb_driver usb_audio_driver = {
 
 static int __init snd_usb_audio_init(void)
 {
+	int err = 0;
+
 	if (nrpacks < 1 || nrpacks > MAX_PACKS) {
 		printk(KERN_WARNING "invalid nrpacks value.\n");
 		return -EINVAL;
 	}
-	return usb_register(&usb_audio_driver);
+
+#ifdef CONFIG_SWITCH
+	/* Add usb_audio swith class support */
+	err = switch_dev_register(&usb_switch_dev);
+	if (err < 0){
+		printk(KERN_ERR "failed to register switch device");
+		return -EINVAL;
+	}
+#endif
+
+	err = usb_register(&usb_audio_driver);
+	if (err) {
+		switch_dev_unregister(&usb_switch_dev);
+	}
+
+	return err;
 }
 
 static void __exit snd_usb_audio_cleanup(void)
 {
+#ifdef CONFIG_SWITCH
+	switch_dev_unregister(&usb_switch_dev);
+#endif
 	usb_deregister(&usb_audio_driver);
 }
 
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