From afaef83e0aa283c06aa4165fa6ec1bba8e9c6d51 Mon Sep 17 00:00:00 2001
From: Andrew Chant <achant@google.com>
Date: Mon, 26 Mar 2018 16:53:34 -0700
Subject: ALSA jack detection support - match upstream kernel

Match upstream Linux kernel support for UAC2 jack detection.
The patch that was included upstream names USB input and
output jack controls by ending them in
"Input Jack" or "Output Jack" respectively.

see 5a222e84945 ('ALSA: usb-audio: UAC2 jack detection') in
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git

Update UsbAlsaJackDetector appropriately.

Test: Verified on a UAC2 device with the above kernel patch,
tinymix -D 1 produced:
...
2       BOOL    1       Headset - Input Jack                     Off
...
9       BOOL    1       Headset - Output Jack                    On
With a headset connected,  and when the jack was unplugged, Youtube
paused.

Bug: 70632415
Change-Id: I2e5dd48c7a9d174aabbb3a3315496fb30f7a545a
---
 .../jni/com_android_server_UsbAlsaJackDetector.cpp | 37 ++++++++++++++--------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/services/core/jni/com_android_server_UsbAlsaJackDetector.cpp b/services/core/jni/com_android_server_UsbAlsaJackDetector.cpp
index e9d448234e17..ccb4f5995330 100644
--- a/services/core/jni/com_android_server_UsbAlsaJackDetector.cpp
+++ b/services/core/jni/com_android_server_UsbAlsaJackDetector.cpp
@@ -19,6 +19,7 @@
 
 #include "jni.h"
 #include <nativehelper/JNIHelp.h>
+#include "android-base/strings.h"
 #include "android_runtime/AndroidRuntime.h"
 #include "android_runtime/Log.h"
 
@@ -33,24 +34,36 @@
 
 #define DRIVER_NAME "/dev/usb_accessory"
 
-#define USB_IN_JACK_NAME "USB in Jack"
-#define USB_OUT_JACK_NAME "USB out Jack"
+#define USB_IN_JACK_SUFFIX "Input Jack"
+#define USB_OUT_JACK_SUFFIX "Output Jack"
 
 namespace android
 {
 
-static jboolean is_jack_connected(jint card, const char* control) {
+static struct mixer_ctl* find_mixer_with_suffix(struct mixer* card_mixer, const char* suffix) {
+    int id = 0;
+    struct mixer_ctl* ctl;
+    while ((ctl = mixer_get_ctl(card_mixer, id++)) != NULL) {
+        const char* name = mixer_ctl_get_name(ctl);
+        if (android::base::EndsWith(name, suffix)) {
+          return ctl;
+        }
+    }
+    return NULL;
+}
+
+static jboolean is_jack_connected(jint card, const char* suffix) {
   struct mixer* card_mixer = mixer_open(card);
   if (card_mixer == NULL) {
     return true;
   }
-  struct mixer_ctl* ctl = mixer_get_ctl_by_name(card_mixer, control);
+  struct mixer_ctl* ctl = find_mixer_with_suffix(card_mixer, suffix);
   if (!ctl) {
     return true;
   }
   mixer_ctl_update(ctl);
   int val = mixer_ctl_get_value(ctl, 0);
-  ALOGI("JACK %s - value %d\n", control, val);
+  ALOGI("%s - value %d\n", mixer_ctl_get_name(ctl), val);
   mixer_close(card_mixer);
 
   return val != 0;
@@ -66,33 +79,31 @@ static jboolean android_server_UsbAlsaJackDetector_hasJackDetect(JNIEnv* /* env
     }
 
     jboolean has_jack = false;
-    if ((mixer_get_ctl_by_name(card_mixer, USB_IN_JACK_NAME) != NULL) ||
-            (mixer_get_ctl_by_name(card_mixer, USB_OUT_JACK_NAME) != NULL)) {
+    if ((find_mixer_with_suffix(card_mixer, USB_IN_JACK_SUFFIX) != NULL) ||
+            (find_mixer_with_suffix(card_mixer, USB_OUT_JACK_SUFFIX) != NULL)) {
         has_jack = true;
     }
     mixer_close(card_mixer);
     return has_jack;
 }
 
-
 static jboolean android_server_UsbAlsaJackDetector_inputJackConnected(JNIEnv* /* env */,
                                                                       jobject /* thiz */,
                                                                       jint card)
 {
-    return is_jack_connected(card, USB_IN_JACK_NAME);
+    return is_jack_connected(card, USB_IN_JACK_SUFFIX);
 }
 
-
 static jboolean android_server_UsbAlsaJackDetector_outputJackConnected(JNIEnv* /* env */,
                                                                        jobject /* thiz */,
                                                                        jint card)
 {
-    return is_jack_connected(card, USB_OUT_JACK_NAME);
+    return is_jack_connected(card, USB_OUT_JACK_SUFFIX);
 }
 
 static void android_server_UsbAlsaJackDetector_jackDetect(JNIEnv* env,
-                                                                                                        jobject thiz,
-                                                                                                        jint card) {
+                                                          jobject thiz,
+                                                          jint card) {
     jclass jdclass = env->GetObjectClass(thiz);
     jmethodID method_jackDetectCallback = env->GetMethodID(jdclass, "jackDetectCallback", "()Z");
     if (method_jackDetectCallback == NULL) {
-- 
cgit v1.2.3-59-g8ed1b