Fix dbScale generation when adding custom control

Fix dbScale generation when a custom INTEGER ALSA control is added.

Change-Id: I935de59d1ca30466c071972939c8ef200007ceb3
Signed-off-by: Jonathan Aillet <jonathan.aillet@iot.bzh>

1 files changed, 15 insertions, 22 deletions

diff --git a/alsa-binding/Alsa-AddCtl.c b/alsa-binding/Alsa-AddCtl.c
index 60be790..9c48914 100644
--- a/alsa-binding/Alsa-AddCtl.c
+++ b/alsa-binding/Alsa-AddCtl.c
@@ -54,6 +54,11 @@
 #define SNDRV_CTL_TLVD_DB_SCALE_MUTE    0x10000
 
 #endif
+
+#define PRESET_MIN_DB                   -51.0
+#define ZERO_DB                         0.0
+#define PRESET_STEP                     1
+
 static const unsigned int *allocate_bool_fake_tlv(void) {
     static const SNDRV_CTL_TLVD_DECLARE_DB_MINMAX(range, -10000, 0);
     unsigned int *tlv = malloc(sizeof (range));
@@ -62,24 +67,14 @@ static const unsigned int *allocate_bool_fake_tlv(void) {
     return tlv;
 }
 
-static const unsigned int *allocate_int_dbscale_tlv(int min_dB, int max_dB) {
+static const unsigned int *allocate_int_dbscale_tlv(int min_dB, int max_dB, int resolution) {
     // SNDRV_CTL_TLVD_DECLARE_DB_SCALE(range, min, step, mute);
     size_t tlvSize = sizeof (4 * sizeof (unsigned int));
     unsigned int *tlv = malloc(tlvSize);
     tlv[0] = SND_CTL_TLVT_DB_SCALE;
     tlv[1] = 2 * sizeof(int);
     tlv[2] = (int)(min_dB * 100);
-    tlv[3] = (int)((max_dB - min_dB) * 100 / max_dB);
-    return tlv;
-}
-
-static const unsigned int *allocate_int_linear_tlv(int max, int min) {
-    // SNDRV_CTL_TLVD_DECLARE_DB_LINEAR (range, min, max);
-    unsigned int *tlv = malloc(4 * sizeof (unsigned int));
-    tlv[0] = SNDRV_CTL_TLVT_DB_LINEAR;
-    tlv[1] = (unsigned int)(2 * sizeof (unsigned int));
-    tlv[2] = (unsigned int)(-min * 100);
-    tlv[3] = (unsigned int)(max * 100);
+    tlv[3] = (int)((max_dB - min_dB) * 100 / resolution);
     return tlv;
 }
 
@@ -88,7 +83,7 @@ STATIC json_object * addOneSndCtl(afb_req_t request, snd_ctl_t *ctlDev, json_obj
     json_object *tmpJ;
     const char *ctlName;
     ctlRequestT ctlRequest;
-    int ctlMax=100, ctlMin=0, ctlStep, ctlCount, ctlSubDev=0, ctlSndDev=0;
+    int ctlMax=100, ctlMin=0, ctlStep=1, ctlCount=1, ctlSubDev=0, ctlSndDev=0;
     snd_ctl_elem_type_t ctlType=SND_CTL_ELEM_TYPE_NONE;
     snd_ctl_elem_info_t *elemInfo;
     snd_ctl_elem_id_t *elemId;
@@ -107,7 +102,6 @@ STATIC json_object * addOneSndCtl(afb_req_t request, snd_ctl_t *ctlDev, json_obj
         goto OnErrorExit;
     }
 
-
     // We are facing a software ctl
     if (ctlNumid == CTL_AUTO) {
         done = json_object_object_get_ex(ctlJ, "type", &tmpJ);
@@ -224,10 +218,12 @@ STATIC json_object * addOneSndCtl(afb_req_t request, snd_ctl_t *ctlDev, json_obj
                 }
             }
 
+            // Prepare fake dbscale TLV values
+            int min = PRESET_MIN_DB, max = ZERO_DB, step = PRESET_STEP;
+
             // Fulup needed to be tested with some dB expert !!!
             json_object *dbscaleJ;
             if (json_object_object_get_ex(ctlJ, "dbscale", &dbscaleJ)) {
-                int min, max;
 
                 if (json_object_get_type(dbscaleJ) != json_type_object) {
                     afb_req_fail_f(request, "ctl-invalid-dbscale", "devid=%s crl=%s invalid json in integer control", snd_ctl_name(ctlDev), json_object_get_string(ctlJ));
@@ -246,16 +242,13 @@ STATIC json_object * addOneSndCtl(afb_req_t request, snd_ctl_t *ctlDev, json_obj
 
                     // default value 1dB
                     json_object_object_get_ex(ctlJ, "step", &tmpJ);
-                    int step = json_object_get_int(tmpJ);
+                    step = json_object_get_int(tmpJ);
                     if (step <= 0) step = 1;
-
-                    elemTlv = allocate_int_dbscale_tlv(min, max);
-
                 }
-            } else {
-                // provide a fake linear TLV
-                elemTlv = allocate_int_linear_tlv(ctlMin, ctlMax);
             }
+
+            elemTlv = allocate_int_dbscale_tlv(min, max, (ctlMax - ctlMin));
+
             break;
 
         case SND_CTL_ELEM_TYPE_ENUMERATED: