hal: Backend port specific channel mapping for afe-loopback

- Add support for Backend port specific channel map for
  afe-loopback usecase.

Change-Id: I7a246a97d5ca38e084e4675563bb283d839ac0fe
diff --git a/hal/audio_extn/audio_extn.c b/hal/audio_extn/audio_extn.c
index 077ec99..86dcbf6 100644
--- a/hal/audio_extn/audio_extn.c
+++ b/hal/audio_extn/audio_extn.c
@@ -621,12 +621,17 @@
 // END: ANC_HEADSET -------------------------------------------------------
 
 static int32_t afe_proxy_set_channel_mapping(struct audio_device *adev,
-                                                     int channel_count)
+                                                     int channel_count,
+                                                     snd_device_t snd_device)
 {
-    struct mixer_ctl *ctl;
+    struct mixer_ctl *ctl = NULL, *be_ctl = NULL;
     const char *mixer_ctl_name = "Playback Device Channel Map";
-    long set_values[8] = {0};
-    int ret;
+    const char *be_mixer_ctl_name = "Backend Device Channel Map";
+    long set_values[FCC_8] = {0};
+    long be_set_values[FCC_8 + 1] = {0};
+    int ret = -1;
+    int be_idx = -1;
+
     ALOGV("%s channel_count:%d",__func__, channel_count);
 
     switch (channel_count) {
@@ -658,21 +663,42 @@
         return -EINVAL;
     }
 
-    ctl = mixer_get_ctl_by_name(adev->mixer, mixer_ctl_name);
+    be_idx = platform_get_snd_device_backend_index(snd_device);
+
+    if (be_idx >= 0) {
+        be_ctl = mixer_get_ctl_by_name(adev->mixer, be_mixer_ctl_name);
+        if (!be_ctl) {
+            ALOGD("%s: Could not get ctl for mixer cmd - %s, using default control",
+                  __func__, be_mixer_ctl_name);
+            ctl = mixer_get_ctl_by_name(adev->mixer, mixer_ctl_name);
+        } else
+            ctl = be_ctl;
+    } else
+         ctl = mixer_get_ctl_by_name(adev->mixer, mixer_ctl_name);
+
     if (!ctl) {
         ALOGE("%s: Could not get ctl for mixer cmd - %s",
               __func__, mixer_ctl_name);
         return -EINVAL;
     }
+
     ALOGV("AFE: set mapping(%ld %ld %ld %ld %ld %ld %ld %ld) for channel:%d",
         set_values[0], set_values[1], set_values[2], set_values[3], set_values[4],
         set_values[5], set_values[6], set_values[7], channel_count);
-    ret = mixer_ctl_set_array(ctl, set_values, channel_count);
+
+    if (!be_ctl)
+        ret = mixer_ctl_set_array(ctl, set_values, channel_count);
+    else {
+       be_set_values[0] = be_idx;
+       memcpy(&be_set_values[1], set_values, sizeof(long) * channel_count);
+       ret = mixer_ctl_set_array(ctl, be_set_values, ARRAY_SIZE(be_set_values));
+    }
+
     return ret;
 }
 
 int32_t audio_extn_set_afe_proxy_channel_mixer(struct audio_device *adev,
-                                    int channel_count)
+                                    int channel_count, snd_device_t snd_device)
 {
     int32_t ret = 0;
     const char *channel_cnt_str = NULL;
@@ -710,7 +736,7 @@
     mixer_ctl_set_enum_by_string(ctl, channel_cnt_str);
 
     if (channel_count == 6 || channel_count == 8 || channel_count == 2) {
-        ret = afe_proxy_set_channel_mapping(adev, channel_count);
+        ret = afe_proxy_set_channel_mapping(adev, channel_count, snd_device);
     } else {
         ALOGE("%s: set unsupported channel count(%d)",  __func__, channel_count);
         ret = -EINVAL;
diff --git a/hal/audio_extn/audio_extn.h b/hal/audio_extn/audio_extn.h
index 079d33a..4db354e 100644
--- a/hal/audio_extn/audio_extn.h
+++ b/hal/audio_extn/audio_extn.h
@@ -282,7 +282,8 @@
 
 //START: AFE_PROXY_FEATURE
 int32_t audio_extn_set_afe_proxy_channel_mixer(struct audio_device *adev,
-                                               int channel_count);
+                                                    int channel_count,
+                                                    snd_device_t snd_device);
 int32_t audio_extn_read_afe_proxy_channel_masks(struct stream_out *out);
 int32_t audio_extn_get_afe_proxy_channel_count();
 //END: AFE_PROXY_FEATURE
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 5233e5c..baf67d7 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -4342,8 +4342,8 @@
     } else if (devices & AUDIO_DEVICE_OUT_ANLG_DOCK_HEADSET ||
                devices & AUDIO_DEVICE_OUT_DGTL_DOCK_HEADSET) {
         ALOGD("%s: setting USB hadset channel capability(2) for Proxy", __func__);
-        audio_extn_set_afe_proxy_channel_mixer(adev, 2);
         snd_device = SND_DEVICE_OUT_USB_HEADSET;
+        audio_extn_set_afe_proxy_channel_mixer(adev, 2, snd_device);
     } else if (devices &
                 (AUDIO_DEVICE_OUT_USB_DEVICE |
                  AUDIO_DEVICE_OUT_USB_HEADSET)) {
@@ -4363,8 +4363,8 @@
     } else if (devices & AUDIO_DEVICE_OUT_PROXY) {
         channel_count = audio_extn_get_afe_proxy_channel_count();
         ALOGD("%s: setting sink capability(%d) for Proxy", __func__, channel_count);
-        audio_extn_set_afe_proxy_channel_mixer(adev, channel_count);
         snd_device = SND_DEVICE_OUT_AFE_PROXY;
+        audio_extn_set_afe_proxy_channel_mixer(adev, channel_count, snd_device);
     } else {
         ALOGE("%s: Unknown device(s) %#x", __func__, devices);
     }
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index adfeaa5..7191826 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -4893,8 +4893,8 @@
     } else if (devices & AUDIO_DEVICE_OUT_ANLG_DOCK_HEADSET ||
                devices & AUDIO_DEVICE_OUT_DGTL_DOCK_HEADSET) {
         ALOGD("%s: setting USB hadset channel capability(2) for Proxy", __func__);
-        audio_extn_set_afe_proxy_channel_mixer(adev, 2);
         snd_device = SND_DEVICE_OUT_USB_HEADSET;
+        audio_extn_set_afe_proxy_channel_mixer(adev, 2, snd_device);
     } else if (devices &
                 (AUDIO_DEVICE_OUT_USB_DEVICE |
                  AUDIO_DEVICE_OUT_USB_HEADSET)) {
@@ -4915,8 +4915,8 @@
     } else if (devices & AUDIO_DEVICE_OUT_PROXY) {
         channel_count = audio_extn_get_afe_proxy_channel_count();
         ALOGD("%s: setting sink capability(%d) for Proxy", __func__, channel_count);
-        audio_extn_set_afe_proxy_channel_mixer(adev, channel_count);
         snd_device = SND_DEVICE_OUT_AFE_PROXY;
+        audio_extn_set_afe_proxy_channel_mixer(adev, channel_count, snd_device);
     } else {
         ALOGE("%s: Unknown device(s) %#x", __func__, devices);
     }