Initial working implementation for Alsa UCM.

Cleanup format for Alsa control GET.

Status: working in progress

1 files changed, 1056 insertions, 0 deletions

diff --git a/AlsaSound/CoreBinding/AlsaCtlSetGet.c b/AlsaSound/CoreBinding/AlsaCtlSetGet.c
new file mode 100644
index 0000000..a6cd45b
--- /dev/null
+++ b/AlsaSound/CoreBinding/AlsaCtlSetGet.c
@@ -0,0 +1,1056 @@
+/*
+ * AlsaLibMapping -- provide low level interface with ALSA lib (extracted from alsa-json-gateway code)
+ * Copyright (C) 2015,2016,2017, 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.
+
+   References:
+   https://github.com/fulup-bzh/AlsaJsonGateway (original code)
+   http://alsa-lib.sourcearchive.com/documentation/1.0.20/modules.html
+   http://alsa-lib.sourcearchive.com/documentation/1.0.8/group__Control_gd48d44da8e3bfe150e928267008b8ff5.html
+   http://alsa.opensrc.org/HowTo_access_a_mixer_control
+   https://github.com/gch1p/alsa-volume-monitor/blob/master/main.c
+   https://github.com/DongheonKim/android_hardware_alsa-sound/blob/master/ALSAControl.cpp (ALSA low level API)
+
+*/
+
+#define _GNU_SOURCE  // needed for vasprintf
+
+#include <alsa/asoundlib.h>
+#include "AlsaCoreBinding.h"
+#include <systemd/sd-event.h>
+
+
+
+// use to store crl numid user request
+typedef struct {
+    unsigned int numId;
+    json_object *jToken;
+    json_object *jValues;
+    int used;
+} ctlRequestT;
+
+// generic sndctrl event handle hook to event callback when pooling
+typedef struct {
+    struct pollfd pfds;
+    sd_event_source *src;
+    snd_ctl_t  *ctlDev;
+    int quiet;
+    struct afb_event afbevt;
+} evtHandleT;
+
+typedef struct {
+    int ucount;
+    int cardId;
+    evtHandleT *evtHandle;
+} sndHandleT;
+
+typedef struct {
+    char *apiprefix;
+    char *shortname;    
+}cardRegistryT;
+
+cardRegistryT *cardRegistry[MAX_SND_CARD+1];
+
+PUBLIC void NumidsListParse (queryValuesT *queryValues, ctlRequestT *ctlRequest) {
+    json_object *jValues;
+    int length;
+    
+    for (int idx=0; idx < queryValues->count; idx ++) {                
+        ctlRequest[idx].jToken = json_object_array_get_idx (queryValues->jNumIds, idx);
+        ctlRequest[idx].jValues = NULL;
+        ctlRequest[idx].used=0;
+
+        
+        switch (json_object_get_type(ctlRequest[idx].jToken)) {
+            
+            case json_type_int:
+                // if NUMID is not an array then it should be an integer numid with no value
+                ctlRequest[idx].numId = json_object_get_int (ctlRequest[idx].jToken);
+                break;
+
+            case  json_type_array:   
+                // NUMID is an array 1st slot should be numid, optionally values may come after
+                length=json_object_array_length (ctlRequest[idx].jToken);
+                if (length < 1 || length >2) {
+                    ctlRequest[idx].used=-1;
+                    continue; 
+                }
+
+                ctlRequest[idx].numId =json_object_get_int(json_object_array_get_idx (ctlRequest[idx].jToken, 0));
+
+                if (length == 2) {
+                    jValues = json_object_array_get_idx (ctlRequest[idx].jToken, 1);
+                    if (jValues == NULL) {
+                        ctlRequest[idx].used=-1;
+                        continue; 
+                    }            
+                    // Value is an int or an array with potentially multiple subvalues
+                    ctlRequest[idx].jValues = jValues;
+                }
+            default:
+                ctlRequest[idx].used=-1;   
+        }
+    }
+}
+
+PUBLIC  int alsaCheckQuery (struct afb_req request, queryValuesT *queryValues) {
+
+    queryValues->devid = afb_req_value(request, "devid");
+    if (queryValues->devid == NULL) goto OnErrorExit;
+    const char *numids;
+    json_object *jNumIds;
+
+    const char *rqtQuiet = afb_req_value(request, "quiet");
+    if (!rqtQuiet) queryValues->quiet=99; // default super quiet
+    else if (rqtQuiet && ! sscanf (rqtQuiet, "%d", &queryValues->quiet)) {
+        json_object *query = afb_req_json(request);
+        
+        afb_req_fail_f (request, "quiet-notinteger","Query=%s Quiet not integer &quiet=%s&", json_object_to_json_string(query), rqtQuiet);
+        goto OnErrorExit;
+    };
+   
+    // no NumId is interpreted as ALL for get and error for set
+    numids = afb_req_value(request, "numids");
+    if (numids == NULL) {
+        queryValues->count=0;
+        goto OnExit;
+    }
+
+    jNumIds = json_tokener_parse(numids);
+    if (!jNumIds) {
+        afb_req_fail_f (request, "numids-notjson","numids=%s not a valid json entry", numids);
+        goto OnErrorExit;        
+    };
+    
+    enum json_type jtype= json_object_get_type(jNumIds);
+    switch (jtype) {
+        case json_type_array:
+            queryValues->jNumIds = jNumIds;
+            queryValues->count = json_object_array_length (jNumIds);
+            break;
+            
+        case json_type_int:
+            queryValues->count = 1;
+            queryValues->jNumIds = json_object_new_array ();
+            json_object_array_add (queryValues->jNumIds, jNumIds);
+            break;
+        
+        default:           
+            afb_req_fail_f (request, "numid-notarray","NumId=%s NumId not valid JSON array", numids);
+            goto OnErrorExit;        
+    }
+
+OnExit:    
+    return 0;
+    
+OnErrorExit:
+    return 1;
+}
+
+STATIC json_object *DB2StringJsonOject (long dB) {
+    char label [20];
+	if (dB < 0) {
+		snprintf(label, sizeof(label), "-%li.%02lidB", -dB / 100, -dB % 100);
+	} else {
+		snprintf(label, sizeof(label), "%li.%02lidB", dB / 100, dB % 100);
+	}
+
+    // json function takes care of string copy
+	return (json_object_new_string (label));
+}
+
+
+// Direct port from amixer TLV decode routine. This code is too complex for me.
+// I hopefully did not break it when porting it.
+
+STATIC json_object *decodeTlv(unsigned int *tlv, unsigned int tlv_size) {
+    char label[20];
+    unsigned int type = tlv[0];
+    unsigned int size;
+    unsigned int idx = 0;
+    const char *chmap_type = NULL;
+    json_object * decodeTlvJson = json_object_new_object();
+
+    if (tlv_size < (unsigned int) (2 * sizeof (unsigned int))) {
+        printf("TLV size error!\n");
+        return NULL;
+    }
+    type = tlv[idx++];
+    size = tlv[idx++];
+    tlv_size -= (unsigned int) (2 * sizeof (unsigned int));
+    if (size > tlv_size) {
+        fprintf(stderr, "TLV size error (%i, %i, %i)!\n", type, size, tlv_size);
+        return NULL;
+    }
+    switch (type) {
+
+        case SND_CTL_TLVT_CONTAINER:
+        {
+            json_object * containerJson = json_object_new_array();
+
+            size += (unsigned int) (sizeof (unsigned int) - 1);
+            size /= (unsigned int) (sizeof (unsigned int));
+            while (idx < size) {
+                json_object *embedJson;
+
+                if (tlv[idx + 1] > (size - idx) * sizeof (unsigned int)) {
+                    fprintf(stderr, "TLV size error in compound!\n");
+                    return NULL;
+                }
+                embedJson = decodeTlv(tlv + idx, tlv[idx + 1] + 8);
+                json_object_array_add(containerJson, embedJson);
+                idx += (unsigned int) (2 + (tlv[idx + 1] + sizeof (unsigned int) - 1) / sizeof (unsigned int));
+            }
+            json_object_object_add(decodeTlvJson, "container", containerJson);
+            break;
+        }
+
+        case SND_CTL_TLVT_DB_SCALE:
+        {
+            json_object * dbscaleJson = json_object_new_object();
+
+            if (size != 2 * sizeof (unsigned int)) {
+                json_object * arrayJson = json_object_new_array();
+                while (size > 0) {
+                    snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
+                    json_object_array_add(arrayJson, json_object_new_string(label));
+                    size -= (unsigned int) sizeof (unsigned int);
+                }
+                json_object_object_add(dbscaleJson, "array", arrayJson);
+            } else {
+                json_object_object_add(dbscaleJson, "min", DB2StringJsonOject((int) tlv[2]));
+                json_object_object_add(dbscaleJson, "step", DB2StringJsonOject(tlv[3] & 0xffff));
+                json_object_object_add(dbscaleJson, "mute", DB2StringJsonOject((tlv[3] >> 16) & 1));
+            }
+            json_object_object_add(decodeTlvJson, "dbscale", dbscaleJson);
+            break;
+        }
+
+#ifdef SND_CTL_TLVT_DB_LINEAR
+        case SND_CTL_TLVT_DB_LINEAR:
+        {
+            json_object * dbLinearJson = json_object_new_object();
+
+            if (size != 2 * sizeof (unsigned int)) {
+                json_object * arrayJson = json_object_new_array();
+                while (size > 0) {
+                    snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
+                    json_object_array_add(arrayJson, json_object_new_string(label));
+                    size -= (unsigned int) sizeof (unsigned int);
+                }
+                json_object_object_add(dbLinearJson, "offset", arrayJson);
+            } else {
+                json_object_object_add(dbLinearJson, "min", DB2StringJsonOject((int) tlv[2]));
+                json_object_object_add(dbLinearJson, "max", DB2StringJsonOject((int) tlv[3]));
+            }
+            json_object_object_add(decodeTlvJson, "dblinear", dbLinearJson);
+            break;
+        }
+#endif
+
+#ifdef SND_CTL_TLVT_DB_RANGE
+        case SND_CTL_TLVT_DB_RANGE:
+        {
+            json_object *dbRangeJson = json_object_new_object();
+
+            if ((size % (6 * sizeof (unsigned int))) != 0) {
+                json_object *arrayJson = json_object_new_array();
+                while (size > 0) {
+                    snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
+                    json_object_array_add(arrayJson, json_object_new_string(label));
+                    size -= (unsigned int) sizeof (unsigned int);
+                }
+                json_object_object_add(dbRangeJson, "dbrange", arrayJson);
+                break;
+            }
+            while (size > 0) {
+                json_object * embedJson = json_object_new_object();
+                snprintf(label, sizeof (label), "%i,", tlv[idx++]);
+                json_object_object_add(embedJson, "rangemin", json_object_new_string(label));
+                snprintf(label, sizeof (label), "%i", tlv[idx++]);
+                json_object_object_add(embedJson, "rangemax", json_object_new_string(label));
+                embedJson = decodeTlv(tlv + idx, 4 * sizeof (unsigned int));
+                json_object_object_add(embedJson, "tlv", embedJson);
+                idx += 4;
+                size -= (unsigned int) (6 * sizeof (unsigned int));
+                json_object_array_add(dbRangeJson, embedJson);
+            }
+            json_object_object_add(decodeTlvJson, "dbrange", dbRangeJson);
+            break;
+        }
+#endif
+#ifdef SND_CTL_TLVT_DB_MINMAX
+        case SND_CTL_TLVT_DB_MINMAX:
+        case SND_CTL_TLVT_DB_MINMAX_MUTE:
+        {
+            json_object * dbMinMaxJson = json_object_new_object();
+
+            if (size != 2 * sizeof (unsigned int)) {
+                json_object * arrayJson = json_object_new_array();
+                while (size > 0) {
+                    snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
+                    json_object_array_add(arrayJson, json_object_new_string(label));
+                    size -= (unsigned int) sizeof (unsigned int);
+                }
+                json_object_object_add(dbMinMaxJson, "array", arrayJson);
+
+            } else {
+                json_object_object_add(dbMinMaxJson, "min", DB2StringJsonOject((int) tlv[2]));
+                json_object_object_add(dbMinMaxJson, "max", DB2StringJsonOject((int) tlv[3]));
+            }
+
+            if (type == SND_CTL_TLVT_DB_MINMAX_MUTE) {
+                json_object_object_add(decodeTlvJson, "dbminmaxmute", dbMinMaxJson);
+            } else {
+                json_object_object_add(decodeTlvJson, "dbminmax", dbMinMaxJson);
+            }
+            break;
+        }
+#endif
+#ifdef SND_CTL_TLVT_CHMAP_FIXED
+        case SND_CTL_TLVT_CHMAP_FIXED:
+            chmap_type = "fixed";
+            /* Fall through */
+        case SND_CTL_TLVT_CHMAP_VAR:
+            if (!chmap_type)
+                chmap_type = "variable";
+            /* Fall through */
+        case SND_CTL_TLVT_CHMAP_PAIRED:
+            if (!chmap_type)
+                chmap_type = "paired";
+
+            json_object * chmapJson = json_object_new_object();
+            json_object * arrayJson = json_object_new_array();
+
+            while (size > 0) {
+                snprintf(label, sizeof (label), "%s", snd_pcm_chmap_name(tlv[idx++]));
+                size -= (unsigned int) sizeof (unsigned int);
+                json_object_array_add(arrayJson, json_object_new_string(label));
+            }
+            json_object_object_add(chmapJson, chmap_type, arrayJson);
+            json_object_object_add(decodeTlvJson, "chmap", chmapJson);
+            break;
+#endif
+        default:
+        {
+            printf("unk-%i-", type);
+            json_object * arrayJson = json_object_new_array();
+
+            while (size > 0) {
+                snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
+                size -= (unsigned int) sizeof (unsigned int);
+                json_object_array_add(arrayJson, json_object_new_string(label));
+            }
+            break;
+            json_object_object_add(decodeTlvJson, "unknown", arrayJson);
+        }
+    }
+
+    return (decodeTlvJson);
+}
+
+
+// retreive info for one given card
+STATIC  json_object* alsaCardProbe (const char *rqtSndId) {
+    const char  *info, *name;
+    const char *devid, *driver;
+    json_object *ctlDev;
+    snd_ctl_t   *handle;
+    snd_ctl_card_info_t *cardinfo;
+    int err;
+
+    if ((err = snd_ctl_open(&handle, rqtSndId, 0)) < 0) {
+        INFO (afbIface, "SndCard [%s] Not Found", rqtSndId);
+        return NULL;
+    }
+
+    snd_ctl_card_info_alloca(&cardinfo);
+    if ((err = snd_ctl_card_info(handle, cardinfo)) < 0) {
+        snd_ctl_close(handle);
+        WARNING (afbIface, "SndCard [%s] info error: %s", rqtSndId, snd_strerror(err));
+        return NULL;
+    }
+
+    // start a new json object to store card info
+    ctlDev = json_object_new_object();
+
+    devid= snd_ctl_card_info_get_id(cardinfo);
+    json_object_object_add (ctlDev, "devid"  , json_object_new_string(devid));
+    name =  snd_ctl_card_info_get_name(cardinfo);
+    json_object_object_add (ctlDev, "name", json_object_new_string (name));
+
+    if (afbIface->verbosity > 1) {
+        json_object_object_add (ctlDev, "devid", json_object_new_string(rqtSndId));
+        driver= snd_ctl_card_info_get_driver(cardinfo);
+        json_object_object_add (ctlDev, "driver"  , json_object_new_string(driver));
+        info  = strdup(snd_ctl_card_info_get_longname (cardinfo));
+        json_object_object_add (ctlDev, "info" , json_object_new_string (info));
+        INFO (afbIface, "AJG: Soundcard Devid=%-5s devid=%-7s Name=%s\n", rqtSndId, devid, info);
+    }
+
+    // free card handle and return info
+    snd_ctl_close(handle);    
+    return (ctlDev);
+}
+
+// Loop on every potential Sound card and register active one
+PUBLIC void alsaGetInfo (struct afb_req request) {
+    int  card;
+    json_object *ctlDev, *ctlDevs;
+    char devid[32];
+    
+    const char *rqtSndId = afb_req_value(request, "devid");
+
+    // if no specific card requested loop on all
+
+    if (rqtSndId != NULL) {
+        // only one card was requested let's probe it
+        ctlDev = alsaCardProbe (rqtSndId);
+        if (ctlDev != NULL) afb_req_success(request, ctlDev, NULL);
+        else afb_req_fail_f (request, "sndscard-notfound", "SndCard [%s] Not Found", rqtSndId);
+        
+    } else {
+        // return an array of ctlDev
+        ctlDevs =json_object_new_array();
+
+        // loop on potential card number
+        for (card =0; card < MAX_SND_CARD; card++) {
+
+            // build card devid and probe it
+            snprintf (devid, sizeof(devid), "hw:%i", card);
+            ctlDev = alsaCardProbe (devid);
+
+            // Alsa has hole within card list [ignore them]
+            if (ctlDev != NULL) {
+                // add current ctlDev to ctlDevs object
+                json_object_array_add (ctlDevs, ctlDev);
+            }    
+        }
+        afb_req_success (request, ctlDevs, NULL);  
+    }
+}
+
+// pack Alsa element's ACL into a JSON object
+STATIC json_object *getControlAcl (snd_ctl_elem_info_t *info) {
+
+    json_object * jsonAclCtl = json_object_new_object();
+
+    json_object_object_add (jsonAclCtl, "read"   , json_object_new_boolean(snd_ctl_elem_info_is_readable(info)));
+    json_object_object_add (jsonAclCtl, "write"  , json_object_new_boolean(snd_ctl_elem_info_is_writable(info)));
+    json_object_object_add (jsonAclCtl, "inact"  , json_object_new_boolean(snd_ctl_elem_info_is_inactive(info)));
+    json_object_object_add (jsonAclCtl, "volat"  , json_object_new_boolean(snd_ctl_elem_info_is_volatile(info)));
+    json_object_object_add (jsonAclCtl, "lock"   , json_object_new_boolean(snd_ctl_elem_info_is_locked(info)));
+
+    // if TLV is readable we insert its ACL
+    if (!snd_ctl_elem_info_is_tlv_readable(info)) {
+        json_object * jsonTlv = json_object_new_object();
+
+        json_object_object_add (jsonTlv, "read"   , json_object_new_boolean(snd_ctl_elem_info_is_tlv_readable(info)));
+        json_object_object_add (jsonTlv, "write"  , json_object_new_boolean(snd_ctl_elem_info_is_tlv_writable(info)));
+        json_object_object_add (jsonTlv, "command", json_object_new_boolean(snd_ctl_elem_info_is_tlv_commandable(info)));
+
+        json_object_object_add (jsonAclCtl, "tlv", jsonTlv);
+    }
+    return (jsonAclCtl);
+}
+
+// process ALSA control and store resulting value into ctlRequest
+STATIC int alsaSetSingleCtl (snd_ctl_t *ctlDev, snd_ctl_elem_id_t *elemId, ctlRequestT *ctlRequest) {
+    snd_ctl_elem_value_t *elemData;
+    snd_ctl_elem_info_t  *elemInfo;
+    int count, length, err, valueIsArray;
+
+    // let's make sure we are processing the right control    
+    if (ctlRequest->numId != snd_ctl_elem_id_get_numid (elemId)) goto OnErrorExit;
+         
+    // set info event ID and get value
+    snd_ctl_elem_info_alloca(&elemInfo);
+    snd_ctl_elem_info_set_id(elemInfo, elemId);  // map ctlInfo to ctlId elemInfo is updated !!!
+    if (snd_ctl_elem_info(ctlDev, elemInfo) < 0) {
+        NOTICE (afbIface, "Fail to load ALSA NUMID=%d Values=[%s]", ctlRequest->numId, json_object_to_json_string(ctlRequest->jValues));
+        goto OnErrorExit;
+    }
+    
+    snd_ctl_elem_info_get_id(elemInfo, elemId);  // map ctlInfo to ctlId elemInfo is updated !!!
+    if (!snd_ctl_elem_info_is_writable(elemInfo)) {
+        NOTICE (afbIface, "Not Writable ALSA NUMID=%d Values=[%s]", ctlRequest->numId, json_object_to_json_string(ctlRequest->jValues));
+        goto OnErrorExit;
+    }
+    
+    count = snd_ctl_elem_info_get_count (elemInfo);
+    if (!json_object_is_type (ctlRequest->jValues, json_type_array)) {
+        length=1;
+        valueIsArray=0;
+    } else {
+        length = json_object_array_length (ctlRequest->jValues);
+        valueIsArray=1;
+    }
+
+    if (count == 0 || count < length) {
+        NOTICE (afbIface, "Invalid Values ALSA NUMID=%d Values=[%s] wanted count=%d", ctlRequest->numId, json_object_to_json_string(ctlRequest->jValues), count);
+        goto OnErrorExit;
+    }
+
+    snd_ctl_elem_value_alloca(&elemData);    
+    snd_ctl_elem_value_set_id(elemData, elemId);  // map ctlInfo to ctlId elemInfo is updated !!!
+    if (snd_ctl_elem_read(ctlDev, elemData) < 0) goto OnErrorExit;   
+
+    // Loop on every control value and push to sndcard
+    for (int index=0; index < count && index < length; index++) {
+        json_object *element;
+        int value;
+        
+        if (valueIsArray) element= json_object_array_get_idx(ctlRequest->jValues, index);
+        else element= ctlRequest->jValues;
+        
+        value= json_object_get_int (element);
+        snd_ctl_elem_value_set_integer(elemData, index, value);
+    }
+
+    if ((err = snd_ctl_elem_write(ctlDev, elemData)) < 0) {
+        NOTICE (afbIface, "Fail to write ALSA NUMID=%d Values=[%s]", ctlRequest->numId, json_object_to_json_string(ctlRequest->jValues));
+        goto OnErrorExit;
+    }
+    
+    ctlRequest->used=1;
+    return 0;
+   
+ OnErrorExit:
+    ctlRequest->used=-1;
+    return -1;   
+}
+
+// process ALSA control and store then into ctlRequest
+STATIC int alsaGetSingleCtl (snd_ctl_t *ctlDev, snd_ctl_elem_id_t *elemId, ctlRequestT *ctlRequest, int quiet) {
+    snd_ctl_elem_type_t  elemType;
+    snd_ctl_elem_value_t *elemData;
+    snd_ctl_elem_info_t  *elemInfo;
+    int count, idx, err;
+
+         
+    // set info event ID and get value
+
+    snd_ctl_elem_info_alloca(&elemInfo);
+    snd_ctl_elem_info_set_id(elemInfo, elemId);  // map ctlInfo to ctlId elemInfo is updated !!!
+    if (snd_ctl_elem_info(ctlDev, elemInfo) < 0) goto OnErrorExit;
+    count = snd_ctl_elem_info_get_count (elemInfo); 
+    if (count == 0) goto OnErrorExit;
+    
+    snd_ctl_elem_info_get_id(elemInfo, elemId);  // map ctlInfo to ctlId elemInfo is updated !!!
+    if (!snd_ctl_elem_info_is_readable(elemInfo)) goto OnErrorExit;
+    elemType = snd_ctl_elem_info_get_type(elemInfo);    
+
+    snd_ctl_elem_value_alloca(&elemData);    
+    snd_ctl_elem_value_set_id(elemData, elemId);  // map ctlInfo to ctlId elemInfo is updated !!!
+    if (snd_ctl_elem_read(ctlDev, elemData) < 0) goto OnErrorExit;
+
+    ctlRequest->jValues= json_object_new_object();
+    json_object_object_add (ctlRequest->jValues,"numid" , ctlRequest->jToken);
+    if (quiet < 2) json_object_object_add (ctlRequest->jValues,"name" , json_object_new_string(snd_ctl_elem_id_get_name (elemId)));
+    if (quiet < 1) json_object_object_add (ctlRequest->jValues,"iface" , json_object_new_string(snd_ctl_elem_iface_name(snd_ctl_elem_id_get_interface(elemId))));
+    if (quiet < 3) json_object_object_add (ctlRequest->jValues,"actif", json_object_new_boolean(!snd_ctl_elem_info_is_inactive(elemInfo)));
+
+    json_object *jsonValuesCtl = json_object_new_array();
+    for (idx = 0; idx < count; idx++) { // start from one in amixer.c !!!
+        switch (elemType) {
+        case SND_CTL_ELEM_TYPE_BOOLEAN: {
+                json_object_array_add (jsonValuesCtl, json_object_new_boolean (snd_ctl_elem_value_get_boolean(elemData, idx)));
+                break;
+                }
+        case SND_CTL_ELEM_TYPE_INTEGER:
+                json_object_array_add (jsonValuesCtl, json_object_new_int ((int)snd_ctl_elem_value_get_integer(elemData, idx)));
+                break;
+        case SND_CTL_ELEM_TYPE_INTEGER64:
+                json_object_array_add (jsonValuesCtl, json_object_new_int64 (snd_ctl_elem_value_get_integer64(elemData, idx)));
+                break;
+        case SND_CTL_ELEM_TYPE_ENUMERATED:
+                json_object_array_add (jsonValuesCtl, json_object_new_int (snd_ctl_elem_value_get_enumerated(elemData, idx)));
+                break;
+        case SND_CTL_ELEM_TYPE_BYTES:
+                json_object_array_add (jsonValuesCtl, json_object_new_int ((int)snd_ctl_elem_value_get_byte(elemData, idx)));
+                break;
+        case SND_CTL_ELEM_TYPE_IEC958: {
+                json_object *jsonIec958Ctl = json_object_new_object();
+                snd_aes_iec958_t iec958;
+                snd_ctl_elem_value_get_iec958(elemData, &iec958);
+
+                json_object_object_add (jsonIec958Ctl,"AES0",json_object_new_int(iec958.status[0]));
+                json_object_object_add (jsonIec958Ctl,"AES1",json_object_new_int(iec958.status[1]));
+                json_object_object_add (jsonIec958Ctl,"AES2",json_object_new_int(iec958.status[2]));
+                json_object_object_add (jsonIec958Ctl,"AES3",json_object_new_int(iec958.status[3]));
+                json_object_array_add  (jsonValuesCtl, jsonIec958Ctl);
+                break;
+                }
+        default:
+                json_object_array_add (jsonValuesCtl, json_object_new_string ("?unknown?"));
+                break;
+        }
+    }
+    json_object_object_add (ctlRequest->jValues,"value",jsonValuesCtl);
+
+    if (!quiet) {  // in simple mode do not print usable values
+        json_object *jsonClassCtl = json_object_new_object();
+        json_object_object_add (jsonClassCtl,"type" , json_object_new_string(snd_ctl_elem_type_name(elemType)));
+		json_object_object_add (jsonClassCtl,"count", json_object_new_int(count));
+
+		switch (elemType) {
+			case SND_CTL_ELEM_TYPE_INTEGER:
+				json_object_object_add (jsonClassCtl,"min",  json_object_new_int((int)snd_ctl_elem_info_get_min(elemInfo)));
+				json_object_object_add (jsonClassCtl,"max",  json_object_new_int((int)snd_ctl_elem_info_get_max(elemInfo)));
+				json_object_object_add (jsonClassCtl,"step", json_object_new_int((int)snd_ctl_elem_info_get_step(elemInfo)));
+				break;
+			case SND_CTL_ELEM_TYPE_INTEGER64:
+				json_object_object_add (jsonClassCtl,"min",  json_object_new_int64(snd_ctl_elem_info_get_min64(elemInfo)));
+				json_object_object_add (jsonClassCtl,"max",  json_object_new_int64(snd_ctl_elem_info_get_max64(elemInfo)));
+				json_object_object_add (jsonClassCtl,"step", json_object_new_int64(snd_ctl_elem_info_get_step64(elemInfo)));
+				break;
+			case SND_CTL_ELEM_TYPE_ENUMERATED: {
+				unsigned int item, items = snd_ctl_elem_info_get_items(elemInfo);
+				json_object *jsonEnum = json_object_new_array();
+
+				for (item = 0; item < items; item++) {
+					snd_ctl_elem_info_set_item(elemInfo, item);
+					if ((err = snd_ctl_elem_info(ctlDev, elemInfo)) >= 0) {
+						json_object_array_add (jsonEnum, json_object_new_string(snd_ctl_elem_info_get_item_name(elemInfo)));
+					}
+				}
+				json_object_object_add (jsonClassCtl, "enums",jsonEnum);
+				break;
+			}
+			default: break; // ignore any unknown type
+			}
+
+		// add collected class info with associated ACLs
+		json_object_object_add (ctlRequest->jValues,"ctrl", jsonClassCtl);
+		json_object_object_add (ctlRequest->jValues,"acl"  , getControlAcl (elemInfo));
+
+		// check for tlv [direct port from amixer.c]
+		if (snd_ctl_elem_info_is_tlv_readable(elemInfo)) {
+				unsigned int *tlv;
+				tlv = malloc(4096);
+				if ((err = snd_ctl_elem_info(ctlDev, elemInfo)) < 0) {
+					fprintf (stderr, "Control %s element TLV read error\n", snd_strerror(err));
+					free(tlv);
+				} else {
+					json_object_object_add (ctlRequest->jValues,"tlv", decodeTlv (tlv, 4096));
+		   }
+		}
+    }
+    ctlRequest->used=1;
+    return 0;
+   
+ OnErrorExit:
+    ctlRequest->used=-1;
+    return -1;   
+}
+
+// assign multiple control to the same value
+PUBLIC void alsaSetGetCtls (struct afb_req request, ActionSetGetT action) {
+    ctlRequestT *ctlRequest;
+    const char *warmsg=NULL;
+    int err=0, status=0;
+    unsigned int ctlCount;
+    snd_ctl_t *ctlDev;
+    snd_ctl_elem_list_t *ctlList;  
+    json_object *sndctls=json_object_new_array();;
+    queryValuesT queryValues;
+       
+    err = alsaCheckQuery (request, &queryValues);
+    if (err) goto OnErrorExit;
+    
+
+    if ((err = snd_ctl_open(&ctlDev, queryValues.devid, 0)) < 0) {
+        afb_req_fail_f (request, "sndcrl-notfound","devid=[%s] load fail error=%s\n", queryValues.devid, snd_strerror(err));
+        goto OnErrorExit;
+    }
+    
+    snd_ctl_elem_list_alloca(&ctlList); 
+    if ((err = snd_ctl_elem_list (ctlDev, ctlList)) < 0) {
+        afb_req_fail_f (request, "listInit-failed","devid=[%s] load fail error=%s\n", queryValues.devid, snd_strerror(err));
+        goto OnErrorExit;
+    }
+
+    if ((err = snd_ctl_elem_list_alloc_space(ctlList, snd_ctl_elem_list_get_count(ctlList))) < 0) {
+        afb_req_fail_f (request, "listAlloc-failed","devid=[%s] load fail error=%s\n", queryValues.devid, snd_strerror(err));
+        goto OnErrorExit;
+    }
+    
+    if ((err = snd_ctl_elem_list (ctlDev, ctlList)) < 0) {
+        afb_req_fail_f (request, "listOpen-failed","devid=[%s] load fail error=%s\n", queryValues.devid, snd_strerror(err));
+        goto OnErrorExit;
+    }
+
+    // Parse numids string (empty == all)
+    ctlCount= snd_ctl_elem_list_get_used(ctlList);
+    if (queryValues.count==0) {
+        ctlRequest= alloca (sizeof(ctlRequestT)*(ctlCount));
+    } else {
+        ctlRequest= alloca (sizeof(ctlRequestT)*(queryValues.count));
+        NumidsListParse (&queryValues, ctlRequest);
+    }  
+        
+    // Loop on all ctlDev controls
+    for (int ctlIndex=0; ctlIndex < ctlCount; ctlIndex++) {
+        unsigned int selected=0;
+        int jdx;
+        
+        if (queryValues.count == 0) {
+                selected=1; // check is this numid is selected within query        
+                jdx = ctlIndex;  // map all existing ctl as requested
+        } else {
+            int numid = snd_ctl_elem_list_get_numid(ctlList, ctlIndex); 
+            if (numid < 0) {
+                NOTICE (afbIface,"snd_ctl_elem_list_get_numid index=%d fail", ctlIndex);
+                continue;
+            }
+            // check if current control was requested in query numids list
+            for (jdx=0; jdx < queryValues.count; jdx++) {
+                if (numid == ctlRequest[jdx].numId) {
+                    selected = 1;
+                    break;
+                }
+            }            
+        }
+        
+        // control is selected open ctlid and get value 
+        if (selected) {
+            snd_ctl_elem_id_t  *elemId;
+            snd_ctl_elem_id_alloca(&elemId);
+           
+            snd_ctl_elem_list_get_id (ctlList, ctlIndex, elemId);
+            switch (action) {
+                case ACTION_GET:
+                    err = alsaGetSingleCtl (ctlDev, elemId, &ctlRequest[jdx], queryValues.quiet);
+                break;
+                
+                case ACTION_SET:
+                    err = alsaSetSingleCtl (ctlDev, elemId, &ctlRequest[jdx]);
+                    
+                default:
+                    err = 1;
+            }
+            if (err) status++;
+            else {
+                json_object_array_add (sndctls, ctlRequest[jdx].jValues);
+            }
+        }
+    }
+  
+    // if we had error let's add them into response message info
+    json_object *warnings = json_object_new_array();
+    for (int jdx=0; jdx < queryValues.count; jdx++) {
+        if (ctlRequest[jdx].used <= 0) {
+            json_object *failctl = json_object_new_object();
+            json_object_object_add (failctl, "numid", ctlRequest[jdx].jToken);
+            if (ctlRequest[jdx].jValues) 
+                json_object_object_add(failctl, "values", ctlRequest[jdx].jValues);
+
+            if (ctlRequest[jdx].numId == -1) json_object_object_add (failctl, "info", json_object_new_string ("Invalid NumID"));
+            else {
+               if (ctlRequest[jdx].used == 0) json_object_object_add (failctl, "info", json_object_new_string ("Does Not Exist"));
+               if (ctlRequest[jdx].used == -1) json_object_object_add (failctl, "info", json_object_new_string ("Invalid Value"));
+            }
+            json_object_array_add (warnings, failctl);
+        }
+        /* WARNING!!!! Check with Jose why following put free jValues
+        if (ctlRequest[jdx].jToken) json_object_put(ctlRequest[jdx].jToken);
+        if (ctlRequest[jdx].jValues) json_object_put(ctlRequest[jdx].jValues);
+        */
+    }
+    
+    if (json_object_array_length(warnings)) warmsg=json_object_to_json_string_ext(warnings, JSON_C_TO_STRING_PLAIN);
+  
+    // send response+warning if any
+    afb_req_success (request, sndctls, warmsg);
+    snd_ctl_elem_list_clear(ctlList);
+    
+    OnErrorExit:
+        return;        
+}
+
+PUBLIC void alsaGetCtls (struct afb_req request) {
+    alsaSetGetCtls (request, ACTION_GET);
+}
+    
+PUBLIC void alsaSetCtls (struct afb_req request) {
+    alsaSetGetCtls (request, ACTION_SET);
+}
+
+
+// This routine is called when ALSA event are fired
+STATIC  int sndCtlEventCB (sd_event_source* src, int fd, uint32_t revents, void* userData) {
+    int err;
+    evtHandleT *evtHandle = (evtHandleT*)userData; 
+    snd_ctl_event_t *eventId;
+    json_object *ctlEventJ;
+    unsigned int mask;
+    int iface;
+    int device;
+    int subdev;
+    const char*devname;
+    ctlRequestT ctlRequest;
+    snd_ctl_elem_id_t *elemId;
+    
+    if ((revents & EPOLLHUP) != 0) {
+        NOTICE (afbIface, "SndCtl hanghup [car disconnected]");
+        goto ExitOnSucess;
+    }
+    
+    if ((revents & EPOLLIN) != 0)  {
+        
+        // initialise event structure on stack  
+        snd_ctl_event_alloca(&eventId); 
+        snd_ctl_elem_id_alloca(&elemId);
+        
+        err = snd_ctl_read(evtHandle->ctlDev, eventId);
+        if (err < 0) goto OnErrorExit;
+        
+        // we only process sndctrl element
+        if (snd_ctl_event_get_type(eventId) != SND_CTL_EVENT_ELEM) goto ExitOnSucess;
+       
+        // we only process value changed events
+        mask = snd_ctl_event_elem_get_mask(eventId);
+        if (!(mask & SND_CTL_EVENT_MASK_VALUE)) goto ExitOnSucess;
+        
+        snd_ctl_event_elem_get_id (eventId, elemId);
+        
+        err = alsaGetSingleCtl (evtHandle->ctlDev, elemId, &ctlRequest, evtHandle->quiet);
+        if (err) goto OnErrorExit;
+
+        iface  = snd_ctl_event_elem_get_interface(eventId);
+        device = snd_ctl_event_elem_get_device(eventId);
+        subdev = snd_ctl_event_elem_get_subdevice(eventId);
+        devname= snd_ctl_event_elem_get_name(eventId);
+        
+        // proxy ctlevent as a binder event        
+        ctlEventJ = json_object_new_object();
+        json_object_object_add(ctlEventJ, "device" ,json_object_new_int (device));
+        json_object_object_add(ctlEventJ, "subdev" ,json_object_new_int (subdev));
+        if (evtHandle->quiet < 2) {
+            json_object_object_add(ctlEventJ, "iface"  ,json_object_new_int (iface));
+            json_object_object_add(ctlEventJ, "devname",json_object_new_string (devname));
+        }
+        if (ctlRequest.jValues) (json_object_object_add(ctlEventJ, "values"  ,ctlRequest.jValues));
+        DEBUG(afbIface, "sndCtlEventCB=%s", json_object_get_string(ctlEventJ));
+        afb_event_push(evtHandle->afbevt, ctlEventJ);
+
+    }
+
+    ExitOnSucess:
+        return 0;
+    
+    OnErrorExit:
+        WARNING (afbIface, "sndCtlEventCB: ignored unsupported event type");
+	return (0);    
+}
+
+// Subscribe to every Alsa CtlEvent send by a given board
+PUBLIC void alsaSubcribe (struct afb_req request) {
+    static sndHandleT sndHandles[MAX_SND_CARD];
+    evtHandleT *evtHandle;
+    snd_ctl_t  *ctlDev;
+    int err, idx, cardId, idxFree=-1;
+    snd_ctl_card_info_t *cardinfo;
+    queryValuesT queryValues;
+
+    
+    err = alsaCheckQuery (request, &queryValues);
+    if (err) goto OnErrorExit;
+
+
+   // open control interface for devid
+    err = snd_ctl_open(&ctlDev, queryValues.devid, SND_CTL_READONLY);
+    if (err < 0) {
+        ctlDev=NULL;
+        afb_req_fail_f (request, "devid-unknown", "SndCard devid=%s Not Found err=%s", queryValues.devid, snd_strerror(err));
+        goto OnErrorExit;
+    }
+    
+    snd_ctl_card_info_alloca(&cardinfo);    
+    if ((err = snd_ctl_card_info(ctlDev, cardinfo)) < 0) {        
+        afb_req_fail_f (request, "devid-invalid", "SndCard devid=%s Not Found err=%s", queryValues.devid, snd_strerror(err));
+        goto OnErrorExit;
+    }
+    
+    cardId=snd_ctl_card_info_get_card(cardinfo);
+    
+    // search for an existing subscription and mark 1st free slot
+    for (idx= 0; idx < MAX_SND_CARD; idx ++) {
+      if (sndHandles[idx].ucount > 0 && cardId == sndHandles[idx].cardId) {
+         evtHandle= sndHandles[idx].evtHandle;
+         break;
+      } else if (idxFree == -1) idxFree= idx; 
+    };
+      
+    // if not subscription exist for the event let's create one
+    if (idx == MAX_SND_CARD) {
+        
+        // reach MAX_SND_CARD event registration
+        if (idxFree == -1) {
+            afb_req_fail_f (request, "register-toomany", "Cannot register new event Maxcard==%devent name=%s", idx);
+            goto OnErrorExit;            
+        } 
+        
+        evtHandle = malloc (sizeof(evtHandleT));
+        evtHandle->ctlDev = ctlDev;
+        evtHandle->quiet  = queryValues.quiet;
+        sndHandles[idxFree].ucount = 0;
+        sndHandles[idxFree].cardId = cardId;
+        sndHandles[idxFree].evtHandle = evtHandle;
+        
+        // subscribe for sndctl events attached to devid
+        err = snd_ctl_subscribe_events(evtHandle->ctlDev, 1);
+        if (err < 0) {
+            afb_req_fail_f (request, "subscribe-fail", "Cannot subscribe events from devid=%s err=%d", queryValues.devid, err);
+            goto OnErrorExit;
+        }
+            
+        // get pollfd attach to this sound board
+        snd_ctl_poll_descriptors(evtHandle->ctlDev, &evtHandle->pfds, 1);
+
+        // register sound event to binder main loop
+        err = sd_event_add_io(afb_daemon_get_event_loop(afbIface->daemon), &evtHandle->src, evtHandle->pfds.fd, EPOLLIN, sndCtlEventCB, evtHandle);
+        if (err < 0) {
+            afb_req_fail_f (request, "register-mainloop", "Cannot hook events to mainloop devid=%s err=%d", queryValues.devid, err);
+            goto OnErrorExit;
+        }
+
+        // create binder event attached to devid name
+        evtHandle->afbevt = afb_daemon_make_event (afbIface->daemon, queryValues.devid);
+        if (!afb_event_is_valid (evtHandle->afbevt)) {
+            afb_req_fail_f (request, "register-event", "Cannot register new binder event name=%s", queryValues.devid);
+            goto OnErrorExit; 
+        }
+
+        // everything looks OK let's move forward 
+        idx=idxFree;
+    }
+    
+    // subscribe to binder event    
+    err = afb_req_subscribe(request, evtHandle->afbevt);
+    if (err != 0) {
+        afb_req_fail_f (request, "register-eventname", "Cannot subscribe binder event name=%s [invalid channel]", queryValues.devid, err);
+        goto OnErrorExit;
+    }
+
+    // increase usage count and return success
+    sndHandles[idx].ucount ++;
+    afb_req_success(request, NULL, NULL);
+    return;
+    
+  OnErrorExit:
+        if (ctlDev) snd_ctl_close(ctlDev);            
+        return;
+}
+
+// Subscribe to every Alsa CtlEvent send by a given board
+PUBLIC void alsaGetCardId (struct afb_req request) {
+    char devid [10];
+    const char *devname, *shortname, *longname;
+    int card, err, index, idx;
+    json_object *respJson;
+    snd_ctl_t   *ctlDev;
+    snd_ctl_card_info_t *cardinfo;
+    
+    const char *sndname = afb_req_value(request, "sndname");
+    if (sndname == NULL) {
+        afb_req_fail_f (request, "argument-missing", "sndname=SndCardName missing");
+        goto OnErrorExit;
+    }
+    
+    // loop on potential card number
+    snd_ctl_card_info_alloca(&cardinfo);  
+    for (card =0; card < MAX_SND_CARD; card++) {
+
+        // build card devid and probe it
+        snprintf (devid, sizeof(devid), "hw:%i", card);
+        
+        // open control interface for devid
+        err = snd_ctl_open(&ctlDev, devid, SND_CTL_READONLY);
+        if (err < 0) continue;   
+        
+        // extract sound card information
+        snd_ctl_card_info(ctlDev, cardinfo);
+        index    = snd_ctl_card_info_get_card(cardinfo);
+        devname  = snd_ctl_card_info_get_id(cardinfo);
+        shortname= snd_ctl_card_info_get_name(cardinfo);
+        longname = snd_ctl_card_info_get_longname(cardinfo);
+        
+        // check if short|long name match        
+        if (!strcmp (sndname, devname)) break;
+        if (!strcmp (sndname, shortname)) break;
+        if (!strcmp (sndname, longname)) break;
+    }
+    
+    if (card == MAX_SND_CARD) {
+        afb_req_fail_f (request, "ctlDev-notfound", "Fail to find card with name=%s", sndname);
+        goto OnErrorExit;
+    }
+    
+    // proxy ctlevent as a binder event        
+    respJson = json_object_new_object();
+    json_object_object_add(respJson, "index"     ,json_object_new_int (index));
+    json_object_object_add(respJson, "devid"     ,json_object_new_string (devid));
+    json_object_object_add(respJson, "shortname" ,json_object_new_string (shortname));
+    json_object_object_add(respJson, "longname"  ,json_object_new_string (longname));
+        
+    // search for a HAL binder card mapping name to api prefix
+    for (idx=0; idx < MAX_SND_CARD; idx++) {
+       if (!strcmp (cardRegistry[idx]->shortname, shortname)) break;
+    }
+    // if a match if found, then we have an HAL for this board let's return its value
+    if (idx < MAX_SND_CARD) json_object_object_add(respJson, "halapi",json_object_new_string (cardRegistry[idx]->apiprefix));
+    
+    afb_req_success(request, respJson, NULL);    
+    return;
+    
+  OnErrorExit:
+        return;  
+}
+
+// Register loaded HAL with board Name and API prefix
+PUBLIC void alsaRegisterHal (struct afb_req request) {
+    static int index=0;
+    const char *shortname, *apiPrefix;
+    
+    apiPrefix = afb_req_value(request, "prefix");
+    if (apiPrefix == NULL) {
+        afb_req_fail_f (request, "argument-missing", "prefix=BindingApiPrefix missing");
+        goto OnErrorExit;
+    }
+    
+    shortname = afb_req_value(request, "name");
+    if (shortname == NULL) {
+        afb_req_fail_f (request, "argument-missing", "sndname=SndCardName missing");
+        goto OnErrorExit;
+    }
+    
+    if (index == MAX_SND_CARD) {
+        afb_req_fail_f (request, "alsahal-toomany", "Fail to register sndname=[%s]", shortname);
+        goto OnErrorExit;        
+    }
+    
+    cardRegistry[index]= malloc (sizeof(cardRegistry));
+    cardRegistry[index]->apiprefix=strdup(apiPrefix);
+    cardRegistry[index]->shortname=strdup(shortname);
+    index++;cardRegistry[index]=NULL;
+ 
+    // when OK nothing to return
+    afb_req_success(request, NULL, NULL);    
+    return;
+    
+  OnErrorExit:
+        return;  
+}
+