Added a POC for ALSA/HAL plugin

1 files changed, 64 insertions, 0 deletions

diff --git a/HAL-afb/HAL-plugin/HalPlugCb.c b/HAL-afb/HAL-plugin/HalPlugCb.c
new file mode 100644
index 0000000..362858d
--- /dev/null
+++ b/HAL-afb/HAL-plugin/HalPlugCb.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2016 "IoT.bzh"
+ * Author Fulup Ar Foll <fulup@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * AfbCallBack (snd_ctl_hal_t *handle, int numid, void **response);
+ *  AfbHalInit is mandatory and called with numid=0
+ * 
+ * Syntax in .asoundrc file
+ *   CrlLabel    { cb MyFunctionName name "My_Second_Control" }
+ * 
+ * Testing:
+ *   amixer -Dagl_hal controls
+ *   amixer -Dagl_hal cget name=My_Sample_Callback
+ */
+
+
+#include "HalPlug.h"
+#include <stdio.h>
+
+int AfbHalInitCB (void *handle, snd_ctl_action_t action, int numid, void*response) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*)handle;
+    
+    fprintf (stdout, "\n  - CB AfbHalInit devid=%s\n", plughandle->devid);
+    return 0;
+}
+
+int AfbHalSampleCB (void *handle, snd_ctl_action_t action, snd_ctl_ext_key_t key, void*response) {
+   
+   switch (action) {
+        case CTLCB_GET_ATTRIBUTE: {
+            fprintf (stdout, "  - AfbHalSampleCB CTLCB_GET_ATTRIBUTE numid=%d\n", (int)key+1);
+            snd_ctl_get_attrib_t *item = (snd_ctl_get_attrib_t*)response;
+            item->type = 1;
+            item->count= 2;
+            item->acc  = SND_CTL_EXT_ACCESS_READWRITE;
+            break;
+        }
+    
+        case CTLCB_GET_INTEGER_INFO: {
+            fprintf (stdout, "  - AfbHalSampleCB CTLCB_GET_INTEGER_INFO numid=%d\n", (int)key+1);
+            snd_ctl_get_int_info_t *item = (snd_ctl_get_attrib_t*)response;
+            item->istep= 10;
+            item->imin = 20;
+            item->imax = 200;
+            break;
+        }
+    
+       default:   
+           fprintf (stdout, "CB AfbHalSampleCB unsupported action=%d numid=%d\n", action, (int)key+1);
+   }
+   return 0; 
+}