Added a POC for ALSA/HAL plugin

6 files changed, 573 insertions, 633 deletions

diff --git a/HAL-afb/HAL-plugin/CMakeLists.txt b/HAL-afb/HAL-plugin/CMakeLists.txt
index 73390b8..5923935 100644
--- a/HAL-afb/HAL-plugin/CMakeLists.txt
+++ b/HAL-afb/HAL-plugin/CMakeLists.txt
@@ -16,26 +16,40 @@
 # limitations under the License.
 ###########################################################################
 
+# Needed to remove undefined snd_dlsym_start in plugin share object
+add_compile_options(-DPIC)
 
 # Add target to project dependency list
-PROJECT_TARGET_ADD(hal-ctl-plugin)
+PROJECT_TARGET_ADD(ctl_afbhal)
 
     # Define targets 
-    ADD_LIBRARY(hal-ctl-plugin MODULE HalPlugCtl.c)
+    ADD_LIBRARY(${TARGET_NAME} MODULE HalPlugCtl.c)
 
     # Alsa Plugin properties
-    SET_TARGET_PROPERTIES(hal-ctl-plugin PROPERTIES
-	PREFIX "alsa-"
+    SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES
+	PREFIX "libasound_module_"
         OUTPUT_NAME ${TARGET_NAME}
     )
 
-PROJECT_TARGET_ADD(hal-pcm-plugin)
+    # Library dependencies (include updates automatically)
+    TARGET_LINK_LIBRARIES(${TARGET_NAME}
+        ${link_libraries}
+    )
+    install(TARGETS ${TARGET_NAME} LIBRARY DESTINATION lib/alsa-lib)
+
+PROJECT_TARGET_ADD(cb_sample)
 
     # Define targets 
-    ADD_LIBRARY(hal-pcm-plugin MODULE HalPlugPcm.c)
+    ADD_LIBRARY(${TARGET_NAME} MODULE HalPlugCb.c)
 
     # Alsa Plugin properties
-    SET_TARGET_PROPERTIES(hal-pcm-plugin PROPERTIES
-	PREFIX "alsa-"
+    SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES
+	PREFIX "afbhal_"
         OUTPUT_NAME ${TARGET_NAME}
     )
+
+    # Library dependencies (include updates automatically)
+    TARGET_LINK_LIBRARIES(${TARGET_NAME}
+        ${link_libraries}
+    )
+    install(TARGETS ${TARGET_NAME} LIBRARY DESTINATION lib)
diff --git a/HAL-afb/HAL-plugin/HalPlug.h b/HAL-afb/HAL-plugin/HalPlug.h
new file mode 100644
index 0000000..5e3da6f
--- /dev/null
+++ b/HAL-afb/HAL-plugin/HalPlug.h
@@ -0,0 +1,92 @@
+/*
+ * 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
+ * 
+ * Syntaxe in .asoundrc file
+ *   CrlLabel    { cb MyFunctionName name "My_Second_Control" }
+ */
+
+
+#include <alsa/asoundlib.h>
+#include <alsa/control_external.h>
+#include <linux/soundcard.h>
+
+#ifndef SOUND_HAL_MAX_CTLS
+#define SOUND_HAL_MAX_CTLS 255
+#endif
+
+
+typedef enum {
+    CTLCB_INIT ,
+    CTLCB_CLOSE ,
+    CTLCB_ELEM_COUNT ,
+    CTLCB_ELEM_LIST ,
+    CTLCB_FIND_ELEM ,
+    CTLCB_FREE_KEY ,
+    CTLCB_GET_ATTRIBUTE ,
+    CTLCB_GET_INTEGER_INFO ,
+    CTLCB_GET_INTEGER64_INFO ,
+    CTLCB_GET_ENUMERATED_INFO ,
+    CTLCB_GET_ENUMERATED_NAME ,
+    CTLCB_READ_INTEGER ,
+    CTLCB_READ_INTEGER64 ,
+    CTLCB_READ_ENUMERATED ,
+    CTLCB_READ_BYTES ,
+    CTLCB_READ_IEC958 ,
+    CTLCB_WRITE_INTEGER ,
+    CTLCB_WRITE_INTEGER64 ,
+    CTLCB_WRITE_ENUMERATED ,
+    CTLCB_WRITE_BYTES ,
+    CTLCB_WRITE_IEC958 ,
+    CTLCB_SUBSCRIBE_EVENTS ,
+    CTLCB_READ_EVENT ,
+    CTLCB_POLL_DESCRIPTORS_COUNT ,
+    CTLCB_POLL_DESCRIPTORS
+} snd_ctl_action_t;
+
+typedef struct {
+  int ctlNumid;
+  const char *ctlName;  
+} snd_ctl_conf_t;
+
+typedef struct {
+    int type;
+    int acc;
+    unsigned count;  
+} snd_ctl_get_attrib_t;
+
+typedef struct {
+    int imin;
+    int imax;
+    int istep;  
+} snd_ctl_get_int_info_t;
+
+typedef int(*snd_ctl_cb_t)(void *handle, snd_ctl_action_t action, snd_ctl_ext_key_t key, void *response);
+
+typedef struct snd_ctl_hal {
+	snd_ctl_ext_t ext;
+	char *devid;
+        snd_ctl_t  *ctlDev;
+	unsigned int ctlsCount;
+        void *dlHandle;
+        snd_ctl_conf_t ctls[SOUND_HAL_MAX_CTLS];
+        snd_ctl_elem_info_t *infos[SOUND_HAL_MAX_CTLS];
+        snd_ctl_cb_t cbs[SOUND_HAL_MAX_CTLS];
+} snd_ctl_hal_t;
+
+
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; 
+}
diff --git a/HAL-afb/HAL-plugin/HalPlugCtl.c b/HAL-afb/HAL-plugin/HalPlugCtl.c
index 21e7cfc..01feedd 100644
--- a/HAL-afb/HAL-plugin/HalPlugCtl.c
+++ b/HAL-afb/HAL-plugin/HalPlugCtl.c
@@ -14,188 +14,202 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  * 
+ * Testing:
+ *  1) Copy generated plugin [libasound_module_pcm_afbhal.so] in alsa-lib/ dir visible from LD_LIBRARY_PATH (eg: /usr/lib64/alsa-lib)
+ *  2) Create a ~/.asounrc file base on following template
+ *      ctl.agl_hal {
+ *      type  afbhal
+ *      devid "hw:4"
+ *      cblib "afbhal_cb_sample.so"
+ *      ctls {
+ *          # ctlLabel {numid integer name "Alsa Ctl Name"}
+ *          MasterSwitch { numid 4 name "My_First_Control" }
+ *          MasterVol    { numid 5 name "My_Second_Control" }
+ *          CB_sample    { ctlcb @AfbHalSampleCB name "My_Sample_Callback"} 
+ *      }
+ *      pcm.agl_hal {
+ *          type copy     # Copy PCM
+ *          slave "hw:4"  # Slave name
+ *      }
+ *
+ *  }
+ *  3) Test with
+ *     - amixer -Dagl_hal controls # should list all your controls
+ *     - amixer -Dagl_hal cget numid=1
+ *     - amixer -Dagl_hal cset numid=1 '10,20'
  */
 
 
 #include <stdio.h>
 #include <sys/ioctl.h>
-#include <alsa/asoundlib.h>
-#include <alsa/control_external.h>
-#include <linux/soundcard.h>
-
-typedef struct afbHalPlug {
-	snd_ctl_ext_t ext;
-	char *device;
-	unsigned int num_vol_ctls;
-	unsigned int num_rec_items;
-	unsigned int vol_ctl[SOUND_MIXER_NRDEVICES];
-	unsigned int rec_item[SOUND_MIXER_NRDEVICES];
-} afbHalPlug_t;
-
-static const char *const vol_devices[SOUND_MIXER_NRDEVICES] = {
-	[SOUND_MIXER_VOLUME]   = "Master Playback Volume",
-	[SOUND_MIXER_BASS]     = "Tone Control - Bass",
-	[SOUND_MIXER_TREBLE]   = "Tone Control - Treble",
-	[SOUND_MIXER_SYNTH]    = "Synth Playback Volume",
-	[SOUND_MIXER_PCM]      = "PCM Playback Volume",
-	[SOUND_MIXER_SPEAKER]  = "PC Speaker Playback Volume",
-	[SOUND_MIXER_LINE]     = "Line Playback Volume",
-	[SOUND_MIXER_MIC]      = "Mic Playback Volume",
-	[SOUND_MIXER_CD]       = "CD Playback Volume",
-	[SOUND_MIXER_IMIX]     = "Monitor Mix Playback Volume",
-	[SOUND_MIXER_ALTPCM]   = "Headphone Playback Volume",
-	[SOUND_MIXER_RECLEV]   = "Capture Volume",
-	[SOUND_MIXER_IGAIN]    = "Capture Volume",
-	[SOUND_MIXER_OGAIN]    = "Playback Volume",
-	[SOUND_MIXER_LINE1]    = "Aux Playback Volume",
-	[SOUND_MIXER_LINE2]    = "Aux1 Playback Volume",
-	[SOUND_MIXER_LINE3]    = "Line1 Playback Volume",
-	[SOUND_MIXER_DIGITAL1] = "IEC958 Playback Volume",
-	[SOUND_MIXER_DIGITAL2] = "Digital Playback Volume",
-	[SOUND_MIXER_DIGITAL3] = "Digital1 Playback Volume",
-	[SOUND_MIXER_PHONEIN]  = "Phone Playback Volume",
-	[SOUND_MIXER_PHONEOUT] = "Master Mono Playback Volume",
-	[SOUND_MIXER_VIDEO]    = "Video Playback Volume",
-	[SOUND_MIXER_RADIO]    = "Radio Playback Volume",
-	[SOUND_MIXER_MONITOR]  = "Monitor Playback Volume",
-};
-
-static const char *const rec_devices[SOUND_MIXER_NRDEVICES] = {
-	[SOUND_MIXER_VOLUME]   = "Mix Capture Switch",
-	[SOUND_MIXER_SYNTH]    = "Synth Capture Switch",
-	[SOUND_MIXER_PCM]      = "PCM Capture Switch",
-	[SOUND_MIXER_LINE]     = "Line Capture Switch",
-	[SOUND_MIXER_MIC]      = "Mic Capture Switch",
-	[SOUND_MIXER_CD]       = "CD Capture Switch",
-	[SOUND_MIXER_LINE1]    = "Aux Capture Switch",
-	[SOUND_MIXER_LINE2]    = "Aux1 Capture Switch",
-	[SOUND_MIXER_LINE3]    = "Line1 Capture Switch",
-	[SOUND_MIXER_DIGITAL1] = "IEC958 Capture Switch",
-	[SOUND_MIXER_DIGITAL2] = "Digital Capture Switch",
-	[SOUND_MIXER_DIGITAL3] = "Digital1 Capture Switch",
-	[SOUND_MIXER_PHONEIN]  = "Phone Capture Switch",
-	[SOUND_MIXER_VIDEO]    = "Video Capture Switch",
-	[SOUND_MIXER_RADIO]    = "Radio Capture Switch",
-};	
-
-static const char *const rec_items[SOUND_MIXER_NRDEVICES] = {
-	[SOUND_MIXER_VOLUME]   = "Mix",
-	[SOUND_MIXER_SYNTH]    = "Synth",
-	[SOUND_MIXER_PCM]      = "PCM",
-	[SOUND_MIXER_LINE]     = "Line",
-	[SOUND_MIXER_MIC]      = "Mic",
-	[SOUND_MIXER_CD]       = "CD",
-	[SOUND_MIXER_LINE1]    = "Aux",
-	[SOUND_MIXER_LINE2]    = "Aux1",
-	[SOUND_MIXER_LINE3]    = "Line1",
-	[SOUND_MIXER_DIGITAL1] = "IEC958",
-	[SOUND_MIXER_DIGITAL2] = "Digital",
-	[SOUND_MIXER_DIGITAL3] = "Digital1",
-	[SOUND_MIXER_PHONEIN]  = "Phone",
-	[SOUND_MIXER_VIDEO]    = "Video",
-	[SOUND_MIXER_RADIO]    = "Radio",
-};	
-
-
-
-
-static snd_ctl_ext_key_t AfbHalElemFind(snd_ctl_ext_t *ext,
-				       const snd_ctl_elem_id_t *id) {
-       
-	snd_ctl_hal_t *ctlHal = ext->private_data;
-	const char *name;
-	unsigned int i, key, numid;
-
-	numid = snd_ctl_elem_id_get_numid(id);
-	if (numid > 0) {
-		numid--;
-		if (numid < afbHalPlug->num_vol_ctls)
-			return afbHalPlug->vol_ctl[numid];
-		numid -= afbHalPlug->num_vol_ctls;
-		if (afbHalPlug->exclusive_input) {
-			if (!numid)
-				return OSS_KEY_CAPTURE_MUX;
-		} else if (numid < afbHalPlug->num_rec_items)
-			return afbHalPlug->rec_item[numid] |
-				OSS_KEY_CAPTURE_FLAG;
-	}
-
-	name = snd_ctl_elem_id_get_name(id);
-	if (! strcmp(name, "Capture Source")) {
-		if (afbHalPlug->exclusive_input)
-			return OSS_KEY_CAPTURE_MUX;
-		else
-			return SND_CTL_EXT_KEY_NOT_FOUND;
-	}
-	for (i = 0; i < afbHalPlug->num_vol_ctls; i++) {
-		key = afbHalPlug->vol_ctl[i];
-		if (! strcmp(name, vol_devices[key]))
-			return key;
-	}
-	for (i = 0; i < afbHalPlug->num_rec_items; i++) {
-		key = afbHalPlug->rec_item[i];
-		if (! strcmp(name, rec_devices[key]))
-			return key | OSS_KEY_CAPTURE_FLAG;
-	}
-	return SND_CTL_EXT_KEY_NOT_FOUND;
+#include "HalPlug.h"
+#include <dlfcn.h>
+
+
+static snd_ctl_ext_key_t AfbHalElemFind(snd_ctl_ext_t *ext, const snd_ctl_elem_id_t *id) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    snd_ctl_ext_key_t key;
+    
+    int numid = snd_ctl_elem_id_get_numid(id);
+    if (numid > 0) {
+        if (numid > plughandle->ctlsCount) goto OnErrorExit;
+        key= (snd_ctl_ext_key_t) numid -1;
+        goto SucessExit;
+    }
+    
+    const char *ctlName= snd_ctl_elem_id_get_name(id);
+    if (ctlName == NULL)  goto OnErrorExit;
+    
+    for (int idx=0; idx < plughandle->ctlsCount; idx++) {
+        if (! strcmp(ctlName, plughandle->ctls[idx].ctlName)) {
+            key = idx;
+            goto SucessExit;
+        }
+    }
+    
+    SucessExit:
+    return key;
+    
+    OnErrorExit:
+      return -1;
 }
 
-static int AfbHalGetAttrib(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
-			     int *type, unsigned int *acc, unsigned int *count) {
-	return 0;
+static int AfbHalGetAttrib(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, int *type, unsigned int *acc, unsigned int *count) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    snd_ctl_elem_info_t  *elemInfo = plughandle->infos[key];
+    snd_ctl_cb_t callback = plughandle->cbs[key];   
+
+    
+    // search for equivalent NUMID in effective sound card
+    if (elemInfo) {
+            *type  = snd_ctl_elem_info_get_type(elemInfo);
+            *count = snd_ctl_elem_info_get_count(elemInfo);
+            *acc   = SND_CTL_EXT_ACCESS_READWRITE; // Future ToBeDone
+            return 0;
+    }
+
+    if (callback) {
+        snd_ctl_get_attrib_t item;
+        
+        int err = callback(plughandle, CTLCB_GET_ATTRIBUTE, key, &item);
+        if (!err) {
+            *type = item.type;
+            *acc  = item.acc;
+            *count= item.count;
+        }
+        return err;
+    }
+    
+    return -1;
 }
 
-static int AfbHalGetInfo(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
-				snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
-				long *imin, long *imax, long *istep) {
-
-	return 0;
+static int AfbHalGetIntInfo(snd_ctl_ext_t *ext,	snd_ctl_ext_key_t key, long *imin, long *imax, long *istep) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    snd_ctl_elem_info_t  *elemInfo = plughandle->infos[key];
+    snd_ctl_cb_t callback = plughandle->cbs[key];   
+    
+    if (elemInfo) {
+    
+        // Should be normalised to make everything 0-100% 
+        *imin = (long)snd_ctl_elem_info_get_min(elemInfo);
+        *imax = (long)snd_ctl_elem_info_get_min(elemInfo);
+        *istep= (long)snd_ctl_elem_info_get_min(elemInfo);
+        return 0;
+    } 
+    
+    if (callback) {
+        snd_ctl_get_int_info_t item;
+        
+        int err = callback(plughandle, CTLCB_GET_INTEGER_INFO, key, &item);
+        if (!err) {
+            *imin = item.imin;
+            *imax = item.imax;
+            *istep= item.istep;
+        }
+        return err;
+    }
+    
+    return -1;
 }
 
-static int AfbHalGetEnumInfo(snd_ctl_ext_t *ext,
-				   snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
-				   unsigned int *items) {
-
-	return 0;
+static int AfbHalGetEnumInfo(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    snd_ctl_elem_info_t  *elemInfo = plughandle->infos[key];
+    snd_ctl_cb_t callback = plughandle->cbs[key];
+    
+    if(elemInfo) *items= snd_ctl_elem_info_get_items(elemInfo);
+    if(callback) callback(plughandle, CTLCB_GET_ENUMERATED_INFO, key, items);
+        
+    return 0;
 }
 
-static int AfbHalGetEnumName(snd_ctl_ext_t *ext,
-				   snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
-				   unsigned int item, char *name,
-				   size_t name_max_len) {
-
-	return 0;
+static int AfbHalGetEnumName(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int item, char *name, size_t name_max_len) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    snd_ctl_elem_info_t  *elemInfo = plughandle->infos[key];
+    
+    //name= snd_ctl_elem_info_get_item_name(elemInfo);
+    return 0;
 }
 
 static int AfbHalReadInt(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    snd_ctl_elem_info_t  *elemInfo = plughandle->infos[key];
 
-	return 0;
+    return 0;
 }
 
-static int AfbHalReadEnumerate(snd_ctl_ext_t *ext,
-			       snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
-			       unsigned int *items) {
+static int AfbHalReadEnumerate(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
 
-	return 0;
+    return 0;
 }
 
 static int AfbHalWriteInt(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
 
     return 0;
 }
 
-static int AfbHalWriteEnum(snd_ctl_ext_t *ext,
-				snd_ctl_ext_key_t key ATTRIBUTE_UNUSED,
-				unsigned int *items) {
+static int AfbHalWriteEnum(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
 
     return 0;
 }
 
-static int AfbHalEventRead(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
-			  snd_ctl_elem_id_t *id ATTRIBUTE_UNUSED,
-			  unsigned int *event_mask ATTRIBUTE_UNUSED)
-{
-	return -EAGAIN;
+static int AfbHalEventRead(snd_ctl_ext_t *ext, snd_ctl_elem_id_t *id, unsigned int *event_mask) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+ 
+    return -EAGAIN;
+}
+
+static int AfbHalElemList(snd_ctl_ext_t *ext, unsigned int offset, snd_ctl_elem_id_t *id) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+
+    snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER);
+    snd_ctl_elem_id_set_name(id, plughandle->ctls[offset].ctlName);
+    
+    return 0;
+}
+
+static int AfbHalElemCount(snd_ctl_ext_t *ext) {
+    snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+    int count = plughandle->ctlsCount;
+    return count;
+}
+
+static void AfbHalClose(snd_ctl_ext_t *ext) {
+	snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data;
+        int err;
+
+        for (int idx=0; idx < plughandle->ctlsCount; idx++) {
+            if (plughandle->ctls[idx].ctlName) free((void*)plughandle->ctls[idx].ctlName);
+        }
+
+        err = snd_ctl_close(plughandle->ctlDev);
+        if (err) SNDERR("Fail Close sndctl: devid=%s err=%s", plughandle->devid, snd_strerror(err)); 
+	
+	if (plughandle->devid) free(plughandle->devid);
+	free(plughandle);
 }
 
 static snd_ctl_ext_callback_t afbHalCBs = {
@@ -204,7 +218,7 @@ static snd_ctl_ext_callback_t afbHalCBs = {
 	.elem_list           = AfbHalElemList,
 	.find_elem           = AfbHalElemFind,
 	.get_attribute       = AfbHalGetAttrib,
-	.get_integer_info    = AfbHalGetInfo,
+	.get_integer_info    = AfbHalGetIntInfo,
 	.get_enumerated_info = AfbHalGetEnumInfo,
 	.get_enumerated_name = AfbHalGetEnumName,
 	.read_integer        = AfbHalReadInt,
@@ -214,54 +228,196 @@ static snd_ctl_ext_callback_t afbHalCBs = {
 	.read_event          = AfbHalEventRead,
 };
 
-
-SND_CTL_PLUGIN_DEFINE_FUNC(afb_hal) {
+SND_CTL_PLUGIN_DEFINE_FUNC(afbhal) {
 
     snd_config_iterator_t it, next;
-    afbHalPlug_t *afbHalPlug;
+    snd_ctl_hal_t *plughandle;
     int err;
-	
-	snd_config_for_each(it, next, conf) {
-		snd_config_t *n = snd_config_iterator_entry(it);
-		const char *id;
-		if (snd_config_get_id(n, &id) < 0)
-			continue;
-		if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0 || strcmp(id, "hint") == 0)
-			continue;
-		if (strcmp(id, "slave") == 0) {
-			if (snd_config_get_string(n, &device) < 0) {
-				SNDERR("Invalid type for %s", id);
-				return -EINVAL;
-			}
-			continue;
-		}
-		SNDERR("Unknown field %s", id);
-		return -EINVAL;
-	}
-
-        // Create ALSA control plugin structure
-	afbHalPlug->ext.version = SND_CTL_EXT_VERSION;
-	afbHalPlug->ext.card_idx = 0; /* FIXME */
-	strcpy(afbHalPlug->ext.id, "AFB-HAL-CTL");
-	strcpy(afbHalPlug->ext.driver, "AFB-HAL");
-	strcpy(afbHalPlug->ext.name, "AFB-HAL Control Plugin");
-	strcpy(afbHalPlug->ext.mixername, "AFB-HAL Mixer Plugin");
-	strcpy(afbHalPlug->ext.longname, "Automotive-Linux Sound Abstraction Control Plugin");
-	afbHalPlug->ext.poll_fd      = -1;
-	afbHalPlug->ext.callback     = &afbHalCBs;
-	afbHalPlug->ext.private_data = afbHalPlug;
-
-
-	err = snd_ctl_ext_create(&afbHalPlug->ext, name, mode);
-	if (err < 0) goto OnErrorExit;
-
-        // Plugin register controls update handlep before exiting
-	*handlep = afbHalPlug->ext.handle;
-	return 0;
+    snd_ctl_cb_t AfbHalInitCB;
+    const char *libname;
+       
+    plughandle = calloc(1, sizeof(snd_ctl_hal_t));
+   
+    snd_config_for_each(it, next, conf) {
+        snd_config_t *node = snd_config_iterator_entry(it);
+        const char *id;
+
+        // ignore comment en empty lines
+        if (snd_config_get_id(node, &id) < 0) continue;
+        if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0 || strcmp(id, "hint") == 0) continue;
+       
+        // devid should point onto a valid sound card
+        if (strcmp(id, "devid") == 0) {
+            const char *devid;
+            if (snd_config_get_string(node, &devid) < 0) {
+                SNDERR("Invalid string type for %s", id);
+                return -EINVAL;
+            }
+            plughandle->devid=strdup(devid);
+                            
+            // open control interface for devid
+            err = snd_ctl_open(&plughandle->ctlDev, plughandle->devid, 0);
+            if (err < 0) {
+                SNDERR("Fail to open control device for devid=%s", plughandle->devid);
+                return -EINVAL;
+            }
+            continue;
+        }
+        
+        if (strcmp(id, "cblib") == 0) {
+            if (snd_config_get_string(node, &libname) < 0) {
+                SNDERR("Invalid libname string for %s", id);
+                return -EINVAL;
+            }
+            
+            plughandle->dlHandle= dlopen(libname, RTLD_NOW);
+            if (!plughandle->dlHandle) {
+                SNDERR("Fail to open callback sharelib=%s error=%s", libname, dlerror());
+                return -EINVAL;                
+            }
+            
+	    AfbHalInitCB = dlsym(plughandle->dlHandle, "AfbHalInitCB");
+            if (!AfbHalInitCB) {
+                SNDERR("Fail find 'AfbHalInitCB' symbol into callbacks sharelib=%s", libname);
+                return -EINVAL;
+            }
+            
+            err = (*AfbHalInitCB)(plughandle,CTLCB_INIT, 0,0);
+            if (err) {
+                SNDERR("Fail AfbHalInitCB err=%d", err);
+                return -EINVAL;
+            }
+            
+            continue;
+        }
+        
+        if (strcmp(id, "ctls") == 0) {
+            const char *ctlConf;
+            snd_config_type_t ctype;
+            snd_config_iterator_t currentCtl, follow;
+            snd_config_t *itemConf;
+            
+            ctype = snd_config_get_type (node);
+            if (ctype != SND_CONFIG_TYPE_COMPOUND) {
+               snd_config_get_string (node, &ctlConf); 
+               SNDERR("Invalid compound type for %s", node);
+               return -EINVAL;
+            }
+            
+            // loop on each ctl within ctls
+            snd_config_for_each (currentCtl, follow, node) {
+                snd_config_t *ctlconfig = snd_config_iterator_entry(currentCtl);
+                snd_ctl_elem_info_t  *elemInfo;
+                const char *ctlLabel, *ctlName;
+                
+                // ignore empty line
+                if (snd_config_get_id(ctlconfig, &ctlLabel) < 0) continue;
+                
+                // each clt should be a valid config compound
+                ctype = snd_config_get_type (ctlconfig);
+                if (ctype != SND_CONFIG_TYPE_COMPOUND) {
+                   snd_config_get_string (node, &ctlConf); 
+                   SNDERR("Invalid ctl config for %s", ctlLabel);
+                   return -EINVAL;
+                }
+                                
+                err=snd_config_search(ctlconfig, "numid", &itemConf);
+                if (!err) {
+                    if (snd_config_get_integer(itemConf, (long*)&plughandle->ctls[plughandle->ctlsCount].ctlNumid) < 0) {
+                    SNDERR("Not Integer: ctl:%s numid should be a valid integer", ctlLabel);
+                    return -EINVAL;
+                    }
+
+                    // Make sure than numid is valid on slave snd card
+                    snd_ctl_elem_info_malloc(&elemInfo);
+                    snd_ctl_elem_info_set_numid(elemInfo, (int)plughandle->ctls[plughandle->ctlsCount].ctlNumid);
+                    plughandle->infos[plughandle->ctlsCount]= elemInfo;
+
+                    err = snd_ctl_elem_info(plughandle->ctlDev, elemInfo);
+                    if (err) {    
+                        SNDERR("Not Found: 'numid=%d' for 'devid=%s'", plughandle->ctls[plughandle->ctlsCount].ctlNumid, plughandle->devid);
+                        return -EINVAL;                                        
+                    }
+                } 
+                
+                err=snd_config_search(ctlconfig, "ctlcb", &itemConf);
+                if (!err) {
+                    const char *funcname;
+                    void *funcaddr;
+                    
+                    if (snd_config_get_string(itemConf, &funcname) < 0) {
+                        SNDERR("Not string: ctl:%s cbname should be a valid string", ctlLabel);
+                        return -EINVAL;
+                    }
+                    
+                    if (funcname[0] != '@') {
+                        SNDERR("Not string: ctl:%s cbname=%s should be prefixed with '@' ", ctlLabel, funcname);
+                        return -EINVAL;
+                    }
+                    
+                    if (!plughandle->dlHandle) {
+                        SNDERR("No CB: ctl:%s cblib:/my/libcallback missing from asoundrc", ctlLabel);
+                        return -EINVAL;
+                    }
+                    
+              	    funcaddr = dlsym(plughandle->dlHandle, &funcname[1]);
+                    if (!funcaddr) {
+                        SNDERR("NotFound CB: ctl:%s cbname='%s' no symbol into %s", ctlLabel, &funcname[1], libname);
+                        return -EINVAL;
+                    }
+                    plughandle->cbs[plughandle->ctlsCount]=funcaddr;
+                }
+                    
+                err=snd_config_search(ctlconfig, "name", &itemConf);
+                if (err) {
+                    SNDERR("Not Found: 'name' mandatory in ctl config");
+                    return -EINVAL;                    
+                }
+                
+                if (snd_config_get_string(itemConf, &ctlName) < 0) {
+                    SNDERR("Not String: ctl:%s 'name' should be a valie string", ctlLabel);
+                    return -EINVAL;
+                }
+                plughandle->ctls[plughandle->ctlsCount].ctlName = strdup(ctlName);
+                
+                // move to next ctl if any
+                plughandle->ctlsCount++;            
+            } // end for each ctl
+            continue;
+        }
+        SNDERR("Unknown field %s", id);
+        return -EINVAL;
+    }        
+
+    
+    
+    // Create ALSA control plugin structure
+    plughandle->ext.version         = SND_CTL_EXT_VERSION;
+    plughandle->ext.card_idx        = 0; /* FIXME */
+    strcpy(plughandle->ext.id       , "AFB-HAL-CTL");
+    strcpy(plughandle->ext.driver   , "AFB-HAL");
+    strcpy(plughandle->ext.name     , "AFB-HAL Control Plugin");
+    strcpy(plughandle->ext.mixername, "AFB-HAL Mixer Plugin");
+    strcpy(plughandle->ext.longname , "Automotive-Linux Sound Abstraction Control Plugin");
+    plughandle->ext.poll_fd         = -1;
+    plughandle->ext.callback        = &afbHalCBs;
+    plughandle->ext.private_data    = (void*)plughandle;
+
+
+
+    err = snd_ctl_ext_create(&plughandle->ext, name, mode);
+    if (err < 0) {
+        SNDERR("Fail Register sndctl for devid=%s", plughandle->devid);
+        goto OnErrorExit;
+    }
+
+    // Plugin register controls update handlep before exiting
+    *handlep = plughandle->ext.handle;
+    return 0;
 
 OnErrorExit: 
-	free(afbHalPlug);
+	free(plughandle);
 	return -1;
 }
 
-SND_CTL_PLUGIN_SYMBOL(afb_hal);
+SND_CTL_PLUGIN_SYMBOL(afbhal);
diff --git a/HAL-afb/HAL-plugin/HalPlugPcm.c b/HAL-afb/HAL-plugin/HalPlugPcm.c
deleted file mode 100644
index d43b44c..0000000
--- a/HAL-afb/HAL-plugin/HalPlugPcm.c
+++ /dev/null
@@ -1,430 +0,0 @@
-/*
- * ALSA <-> OSS PCM I/O plugin
- *
- * Copyright (c) 2005 by Takashi Iwai <tiwai@suse.de>
- *
- * This library is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as
- * published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
- */
-
-#include <stdio.h>
-#include <sys/ioctl.h>
-#include <alsa/asoundlib.h>
-#include <alsa/pcm_external.h>
-#include <linux/soundcard.h>
-
-typedef struct snd_pcm_oss {
-	snd_pcm_ioplug_t io;
-	char *device;
-	int fd;
-	int fragment_set;
-	int caps;
-	int format;
-	unsigned int period_shift;
-	unsigned int periods;
-	unsigned int frame_bytes;
-} snd_pcm_oss_t;
-
-static snd_pcm_sframes_t oss_write(snd_pcm_ioplug_t *io,
-				   const snd_pcm_channel_area_t *areas,
-				   snd_pcm_uframes_t offset,
-				   snd_pcm_uframes_t size)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	const char *buf;
-	ssize_t result;
-
-	/* we handle only an interleaved buffer */
-	buf = (char *)areas->addr + (areas->first + areas->step * offset) / 8;
-	size *= oss->frame_bytes;
-	result = write(oss->fd, buf, size);
-	if (result <= 0)
-		return result;
-	return result / oss->frame_bytes;
-}
-
-static snd_pcm_sframes_t oss_read(snd_pcm_ioplug_t *io,
-				  const snd_pcm_channel_area_t *areas,
-				  snd_pcm_uframes_t offset,
-				  snd_pcm_uframes_t size)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	char *buf;
-	ssize_t result;
-
-	/* we handle only an interleaved buffer */
-	buf = (char *)areas->addr + (areas->first + areas->step * offset) / 8;
-	size *= oss->frame_bytes;
-	result = read(oss->fd, buf, size);
-	if (result <= 0)
-		return result;
-	return result / oss->frame_bytes;
-}
-
-static snd_pcm_sframes_t oss_pointer(snd_pcm_ioplug_t *io)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	struct count_info info;
-	int ptr;
-
-	if (ioctl(oss->fd, io->stream == SND_PCM_STREAM_PLAYBACK ?
-		  SNDCTL_DSP_GETOPTR : SNDCTL_DSP_GETIPTR, &info) < 0) {
-		fprintf(stderr, "*** OSS: oss_pointer error\n");
-		return 0;
-	}
-	ptr = snd_pcm_bytes_to_frames(io->pcm, info.ptr);
-	return ptr;
-}
-
-static int oss_start(snd_pcm_ioplug_t *io)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	int tmp = io->stream == SND_PCM_STREAM_PLAYBACK ?
-		PCM_ENABLE_OUTPUT : PCM_ENABLE_INPUT;
-
-	if (ioctl(oss->fd, SNDCTL_DSP_SETTRIGGER, &tmp) < 0) {
-		fprintf(stderr, "*** OSS: trigger failed\n");
-		if (io->stream == SND_PCM_STREAM_CAPTURE)
-			/* fake read to trigger */
-			read(oss->fd, &tmp, 0);
-	}
-	return 0;
-}
-
-static int oss_stop(snd_pcm_ioplug_t *io)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	int tmp = 0;
-
-	ioctl(oss->fd, SNDCTL_DSP_SETTRIGGER, &tmp);
-	return 0;
-}
-
-static int oss_drain(snd_pcm_ioplug_t *io)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-
-	if (io->stream == SND_PCM_STREAM_PLAYBACK)
-		ioctl(oss->fd, SNDCTL_DSP_SYNC);
-	return 0;
-}
-
-static int oss_prepare(snd_pcm_ioplug_t *io)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	int tmp;
-
-	ioctl(oss->fd, SNDCTL_DSP_RESET);
-
-	tmp = io->channels;
-	if (ioctl(oss->fd, SNDCTL_DSP_CHANNELS, &tmp) < 0) {
-		perror("SNDCTL_DSP_CHANNELS");
-		return -EINVAL;
-	}
-	tmp = oss->format;
-	if (ioctl(oss->fd, SNDCTL_DSP_SETFMT, &tmp) < 0) {
-		perror("SNDCTL_DSP_SETFMT");
-		return -EINVAL;
-	}
-	tmp = io->rate;
-	if (ioctl(oss->fd, SNDCTL_DSP_SPEED, &tmp) < 0 ||
-	    tmp > io->rate * 1.01 || tmp < io->rate * 0.99) {
-		perror("SNDCTL_DSP_SPEED");
-		return -EINVAL;
-	}
-	return 0;
-}
-
-static int oss_hw_params(snd_pcm_ioplug_t *io,
-			 snd_pcm_hw_params_t *params ATTRIBUTE_UNUSED)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-	int i, tmp, err;
-	unsigned int period_bytes;
-	long oflags, flags;
-
-	oss->frame_bytes = (snd_pcm_format_physical_width(io->format) * io->channels) / 8;
-	switch (io->format) {
-	case SND_PCM_FORMAT_U8:
-		oss->format = AFMT_U8;
-		break;
-	case SND_PCM_FORMAT_S16_LE:
-		oss->format = AFMT_S16_LE;
-		break;
-	case SND_PCM_FORMAT_S16_BE:
-		oss->format = AFMT_S16_BE;
-		break;
-	default:
-		fprintf(stderr, "*** OSS: unsupported format %s\n", snd_pcm_format_name(io->format));
-		return -EINVAL;
-	}
-	period_bytes = io->period_size * oss->frame_bytes;
-	oss->period_shift = 0;
-	for (i = 31; i >= 4; i--) {
-		if (period_bytes & (1U << i)) {
-			oss->period_shift = i;
-			break;
-		}
-	}
-	if (! oss->period_shift) {
-		fprintf(stderr, "*** OSS: invalid period size %d\n", (int)io->period_size);
-		return -EINVAL;
-	}
-	oss->periods = io->buffer_size / io->period_size;
-
- _retry:
-	tmp = oss->period_shift | (oss->periods << 16);
-	if (ioctl(oss->fd, SNDCTL_DSP_SETFRAGMENT, &tmp) < 0) {
-		if (! oss->fragment_set) {
-			perror("SNDCTL_DSP_SETFRAGMENT");
-			fprintf(stderr, "*** period shift = %d, periods = %d\n", oss->period_shift, oss->periods);
-			return -EINVAL;
-		}
-		/* OSS has no proper way to reinitialize the fragments */
-		/* try to reopen the device */
-		close(oss->fd);
-		oss->fd = open(oss->device, io->stream == SND_PCM_STREAM_PLAYBACK ?
-			       O_WRONLY : O_RDONLY);
-		if (oss->fd < 0) {
-			err = -errno;
-			SNDERR("Cannot reopen the device %s", oss->device);
-			return err;
-		}
-		io->poll_fd = oss->fd;
-		io->poll_events = io->stream == SND_PCM_STREAM_PLAYBACK ?
-			POLLOUT : POLLIN;
-		snd_pcm_ioplug_reinit_status(io);
-		oss->fragment_set = 0;
-		goto _retry;
-	}
-	oss->fragment_set = 1;
-
-	if ((flags = fcntl(oss->fd, F_GETFL)) < 0) {
-		err = -errno;
-		perror("F_GETFL");
-	} else {
-		oflags = flags;
-		if (io->nonblock)
-			flags |= O_NONBLOCK;
-		else
-			flags &= ~O_NONBLOCK;
-		if (flags != oflags &&
-		    fcntl(oss->fd, F_SETFL, flags) < 0) {
-			err = -errno;
-			perror("F_SETFL");
-		}
-	}
-
-	return 0;
-}
-
-#define ARRAY_SIZE(ary)	(sizeof(ary)/sizeof(ary[0]))
-
-static int oss_hw_constraint(snd_pcm_oss_t *oss)
-{
-	snd_pcm_ioplug_t *io = &oss->io; 
-	static const snd_pcm_access_t access_list[] = {
-		SND_PCM_ACCESS_RW_INTERLEAVED,
-		SND_PCM_ACCESS_MMAP_INTERLEAVED
-	};
-	unsigned int nformats;
-	unsigned int format[5];
-	unsigned int nchannels;
-	unsigned int channel[6];
-	/* period and buffer bytes must be power of two */
-	static const unsigned int bytes_list[] = {
-		1U<<8, 1U<<9, 1U<<10, 1U<<11, 1U<<12, 1U<<13, 1U<<14, 1U<<15,
-		1U<<16, 1U<<17, 1U<<18, 1U<<19, 1U<<20, 1U<<21, 1U<<22, 1U<<23
-	};
-	int i, err, tmp;
-
-	/* check trigger */
-	oss->caps = 0;
-	if (ioctl(oss->fd, SNDCTL_DSP_GETCAPS, &oss->caps) >= 0) {
-		if (! (oss->caps & DSP_CAP_TRIGGER))
-			fprintf(stderr, "*** OSS: trigger is not supported!\n");
-	}
-
-	/* access type - interleaved only */
-	if ((err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_ACCESS,
-						 ARRAY_SIZE(access_list), access_list)) < 0)
-		return err;
-
-	/* supported formats */
-	tmp = 0;
-	ioctl(oss->fd, SNDCTL_DSP_GETFMTS, &tmp);
-	nformats = 0;
-	if (tmp & AFMT_U8)
-		format[nformats++] = SND_PCM_FORMAT_U8;
-	if (tmp & AFMT_S16_LE)
-		format[nformats++] = SND_PCM_FORMAT_S16_LE;
-	if (tmp & AFMT_S16_BE)
-		format[nformats++] = SND_PCM_FORMAT_S16_BE;
-	if (tmp & AFMT_MU_LAW)
-		format[nformats++] = SND_PCM_FORMAT_MU_LAW;
-	if (! nformats)
-		format[nformats++] = SND_PCM_FORMAT_S16;
-	if ((err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_FORMAT,
-						 nformats, format)) < 0)
-		return err;
-	
-	/* supported channels */
-	nchannels = 0;
-	for (i = 0; i < 6; i++) {
-		tmp = i + 1;
-		if (ioctl(oss->fd, SNDCTL_DSP_CHANNELS, &tmp) >= 0)
-			channel[nchannels++] = tmp;
-	}
-	if (! nchannels) /* assume 2ch stereo */
-		err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_CHANNELS,
-						      2, 2);
-	else
-		err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_CHANNELS,
-						    nchannels, channel);
-	if (err < 0)
-		return err;
-
-	/* supported rates */
-	/* FIXME: should query? */
-	err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_RATE, 8000, 480000);
-	if (err < 0)
-		return err;
-
-	/* period size (in power of two) */
-	err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_PERIOD_BYTES,
-					    ARRAY_SIZE(bytes_list), bytes_list);
-	if (err < 0)
-		return err;
-	/* periods */
-	err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_PERIODS, 2, 1024);
-	if (err < 0)
-		return err;
-	/* buffer size (in power of two) */
-	err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_BUFFER_BYTES,
-					    ARRAY_SIZE(bytes_list), bytes_list);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-
-static int oss_close(snd_pcm_ioplug_t *io)
-{
-	snd_pcm_oss_t *oss = io->private_data;
-
-	close(oss->fd);
-	free(oss->device);
-	free(oss);
-	return 0;
-}
-
-static const snd_pcm_ioplug_callback_t oss_playback_callback = {
-	.start = oss_start,
-	.stop = oss_stop,
-	.transfer = oss_write,
-	.pointer = oss_pointer,
-	.close = oss_close,
-	.hw_params = oss_hw_params,
-	.prepare = oss_prepare,
-	.drain = oss_drain,
-};
-
-static const snd_pcm_ioplug_callback_t oss_capture_callback = {
-	.start = oss_start,
-	.stop = oss_stop,
-	.transfer = oss_read,
-	.pointer = oss_pointer,
-	.close = oss_close,
-	.hw_params = oss_hw_params,
-	.prepare = oss_prepare,
-	.drain = oss_drain,
-};
-
-
-SND_PCM_PLUGIN_DEFINE_FUNC(oss)
-{
-	snd_config_iterator_t i, next;
-	const char *device = "/dev/dsp";
-	int err;
-	snd_pcm_oss_t *oss;
-	
-	snd_config_for_each(i, next, conf) {
-		snd_config_t *n = snd_config_iterator_entry(i);
-		const char *id;
-		if (snd_config_get_id(n, &id) < 0)
-			continue;
-		if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0 || strcmp(id, "hint") == 0)
-			continue;
-		if (strcmp(id, "device") == 0) {
-			if (snd_config_get_string(n, &device) < 0) {
-				SNDERR("Invalid type for %s", id);
-				return -EINVAL;
-			}
-			continue;
-		}
-		SNDERR("Unknown field %s", id);
-		return -EINVAL;
-	}
-
-	oss = calloc(1, sizeof(*oss));
-	if (! oss) {
-		SNDERR("cannot allocate");
-		return -ENOMEM;
-	}
-
-	oss->device = strdup(device);
-	if (oss->device == NULL) {
-		SNDERR("cannot allocate");
-		free(oss);
-		return -ENOMEM;
-	}
-	oss->fd = open(device, stream == SND_PCM_STREAM_PLAYBACK ?
-		       O_WRONLY : O_RDONLY);
-	if (oss->fd < 0) {
-		err = -errno;
-		SNDERR("Cannot open device %s", device);
-		goto error;
-	}
-
-	oss->io.version = SND_PCM_IOPLUG_VERSION;
-	oss->io.name = "ALSA <-> OSS PCM I/O Plugin";
-	oss->io.poll_fd = oss->fd;
-	oss->io.poll_events = stream == SND_PCM_STREAM_PLAYBACK ? POLLOUT : POLLIN;
-	oss->io.mmap_rw = 0;
-	oss->io.callback = stream == SND_PCM_STREAM_PLAYBACK ?
-		&oss_playback_callback : &oss_capture_callback;
-	oss->io.private_data = oss;
-
-	err = snd_pcm_ioplug_create(&oss->io, name, stream, mode);
-	if (err < 0)
-		goto error;
-
-	if ((err = oss_hw_constraint(oss)) < 0) {
-		snd_pcm_ioplug_delete(&oss->io);
-		return err;
-	}
-
-	*pcmp = oss->io.pcm;
-	return 0;
-
- error:
-	if (oss->fd >= 0)
-		close(oss->fd);
-	free(oss->device);
-	free(oss);
-	return err;
-}
-
-SND_PCM_PLUGIN_SYMBOL(oss);
diff --git a/HAL-afb/HAL-plugin/README.md b/HAL-afb/HAL-plugin/README.md
new file mode 100644
index 0000000..1c1e7a2
--- /dev/null
+++ b/HAL-afb/HAL-plugin/README.md
@@ -0,0 +1,44 @@
+Hal-Plugin 
+
+Object: provide an ALSA a HAL (Hardware Abstraction Layer) to automotive sound cards
+Status: Current version is proof of concept and not a usable product
+Author: Fulup Ar Foll
+Date  : June-2017
+
+HAL-plugin allows:
+ - to expose any existing NUMID under a customized label name, this is order to abstract sound card config.
+ - to add non alsa NUMID supported through a callback mechanism (eg: volume rampdown, power off, ...)
+
+installation
+ - Plugin should be placed where ever alsaplugins are located (typically: /usr/share/alsa-lib)
+ - Callback sharelib directory should be declare in $LD_LIBRARY_PATH
+
+Config
+```
+cat ~/.asoundrc
+  ctl.agl_hal {
+    type  afbhal
+    devid "hw:4"
+    cblib "afbhal_cb_sample.so"
+    ctls {
+        # ctlLabel {numid integer name "Alsa Ctl Name"}
+        MasterSwitch { numid 4 name "My_First_Control" }
+        MasterVol    { numid 5 name "My_Second_Control" }
+        CB_sample    { ctlcb @AfbHalSampleCB name "My_Sample_Callback"} 
+    }
+    pcm.agl_hal {
+        type copy     # Copy PCM
+        slave "hw:4"  # Slave name
+  }
+```
+
+With such a config file
+ - numid=4 from sndcard=hw:4 is renamed "My_First_Control"
+ - numid=4 from sndcard=hw:4 is renamed "My_Second_Control"
+ - numid=4 will call AfbHalSampleCB from afbhal_cb_sample.so
+
+Note: to really implement a usable HAL at minimum every ALSA call should be implemented and read/write of values should be normalised from 0 to 100% with a step of 1.
+
+Conclusion: This demonstrate that implementing a HAL that both abstract ALSA get/set and enable non ALSA support is possible at an acceptable cost
+without having to hack ALSA source code. The beauty of the model is than it is fully transparent to any ALSA application. The limit is that the plugin is loaded
+within every application context, thus interaction with an external event loop remains complete as well as conflict management in case of share resources.