Initial Working Version on Alsa Policy-Policy-Hook

5 files changed, 679 insertions, 0 deletions

diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h
new file mode 100644
index 0000000..bb2dd79
--- /dev/null
+++ b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h
@@ -0,0 +1,91 @@
+/*
+ * 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/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c
new file mode 100644
index 0000000..b96f3d9
--- /dev/null
+++ b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c
@@ -0,0 +1,66 @@
+/*
+ * 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 "AlsaHalPlug.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/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c
new file mode 100644
index 0000000..5e92dd6
--- /dev/null
+++ b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c
@@ -0,0 +1,423 @@
+/*
+ * 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.
+ * 
+ * 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 "AlsaHalPlug.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 = NULL;
+
+    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) {
+    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 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, 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, 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;
+}
+
+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;
+}
+
+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, 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, 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 = {
+    .close = AfbHalClose,
+    .elem_count = AfbHalElemCount,
+    .elem_list = AfbHalElemList,
+    .find_elem = AfbHalElemFind,
+    .get_attribute = AfbHalGetAttrib,
+    .get_integer_info = AfbHalGetIntInfo,
+    .get_enumerated_info = AfbHalGetEnumInfo,
+    .get_enumerated_name = AfbHalGetEnumName,
+    .read_integer = AfbHalReadInt,
+    .read_enumerated = AfbHalReadEnumerate,
+    .write_integer = AfbHalWriteInt,
+    .write_enumerated = AfbHalWriteEnum,
+    .read_event = AfbHalEventRead,
+};
+
+SND_CTL_PLUGIN_DEFINE_FUNC(afbhal) {
+
+    snd_config_iterator_t it, next;
+    snd_ctl_hal_t *plughandle;
+    int err;
+    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, "ctl") == 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, "ctl", &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(plughandle);
+    return -1;
+}
+
+SND_CTL_PLUGIN_SYMBOL(afbhal);
diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt b/Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt
new file mode 100644
index 0000000..93642b2
--- /dev/null
+++ b/Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt
@@ -0,0 +1,55 @@
+###########################################################################
+# Copyright 2015, 2016, 2017 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.
+###########################################################################
+
+# Activate ALSA  dynamic build build mode get resolve "snd_dlsym_start"
+add_compile_options(-DPIC)
+
+# Add target to project dependency list
+PROJECT_TARGET_ADD(ctl_afbhal)
+
+    # Define targets 
+    ADD_LIBRARY(${TARGET_NAME} MODULE HalPlugCtl.c)
+
+    # Alsa Plugin properties
+    SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES
+	PREFIX "libasound_module_"
+        OUTPUT_NAME ${TARGET_NAME}
+    )
+
+    # Library dependencies (include updates automatically)
+    TARGET_LINK_LIBRARIES(${TARGET_NAME}
+        ${link_libraries}
+    )
+    install(TARGETS ${TARGET_NAME} LIBRARY DESTINATION lib/alsa-lib)
+
+PROJECT_TARGET_ADD(cb_sample)
+
+    # Define targets 
+    ADD_LIBRARY(${TARGET_NAME} MODULE HalPlugCb.c)
+
+    # Alsa Plugin properties
+    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/Alsa-Plugin/_Alsa-Hal-plugin/README.md b/Alsa-Plugin/_Alsa-Hal-plugin/README.md
new file mode 100644
index 0000000..1c1e7a2
--- /dev/null
+++ b/Alsa-Plugin/_Alsa-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.