Convert ac_format and ac_controls to unions to make access a little cleaner

6 files changed, 101 insertions, 105 deletions

diff --git a/apps/system/nxplayer/nxplayer.c b/apps/system/nxplayer/nxplayer.c
index bbd9d5cec..74328c595 100644
--- a/apps/system/nxplayer/nxplayer.c
+++ b/apps/system/nxplayer/nxplayer.c
@@ -255,10 +255,8 @@ static int nxplayer_opendevice(FAR struct nxplayer_s *pPlayer, int format,
                 {
                   /* Test if this device supports the format we want */
 
-                  int ac_format = caps.ac_format[0] | (caps.ac_format[1] << 8);
-
-                  if (((ac_format & (1 << (format - 1))) != 0) &&
-                      (caps.ac_controls[0] & AUDIO_TYPE_OUTPUT))
+                  if (((caps.ac_format.hw & (1 << (format - 1))) != 0) &&
+                      (caps.ac_controls.b[0] & AUDIO_TYPE_OUTPUT))
                     {
                       /* Do subformat detection */
 
@@ -267,7 +265,7 @@ static int nxplayer_opendevice(FAR struct nxplayer_s *pPlayer, int format,
                           /* Prepare to get sub-formats for this main format */
 
                           caps.ac_subtype = format;
-                          caps.ac_format[0] = 0;
+                          caps.ac_format.b[0] = 0;
 
                           while (ioctl(pPlayer->devFd, AUDIOIOC_GETCAPS,
                               (unsigned long) &caps) == caps.ac_len)
@@ -276,13 +274,13 @@ static int nxplayer_opendevice(FAR struct nxplayer_s *pPlayer, int format,
 
                               for (x = 0; x < sizeof(caps.ac_controls); x++)
                                 {
-                                  if (caps.ac_controls[x] == subfmt)
+                                  if (caps.ac_controls.b[x] == subfmt)
                                     {
                                       /* Sub format supported! */
 
                                       break;
                                     }
-                                  else if (caps.ac_controls[x] == AUDIO_SUBFMT_END)
+                                  else if (caps.ac_controls.b[x] == AUDIO_SUBFMT_END)
                                     {
                                       /* Sub format not supported */
 
@@ -300,9 +298,9 @@ static int nxplayer_opendevice(FAR struct nxplayer_s *pPlayer, int format,
                                   break;
                                 }
 
-                              /* Increment ac_format[0] to get next set of subformats */
+                              /* Increment ac_format.b[0] to get next set of subformats */
 
-                              caps.ac_format[0]++;
+                              caps.ac_format.b[0]++;
                             }
                         }
 
@@ -887,10 +885,10 @@ int nxplayer_setvolume(FAR struct nxplayer_s *pPlayer, uint16_t volume)
 #ifdef CONFIG_AUDIO_MULTI_SESSION
       cap_desc.session= pPlayer->session;
 #endif
-      cap_desc.caps.ac_len = sizeof(struct audio_caps_s);
-      cap_desc.caps.ac_type = AUDIO_TYPE_FEATURE;
-      *((uint16_t *) cap_desc.caps.ac_format) = AUDIO_FU_VOLUME;
-      *((uint16_t *) cap_desc.caps.ac_controls) = volume;
+      cap_desc.caps.ac_len            = sizeof(struct audio_caps_s);
+      cap_desc.caps.ac_type           = AUDIO_TYPE_FEATURE;
+      cap_desc.caps.ac_format.hw      = AUDIO_FU_VOLUME;
+      cap_desc.caps.ac_controls.hw[0] = volume;
       ioctl(pPlayer->devFd, AUDIOIOC_CONFIGURE, (unsigned long) &cap_desc);
     }
 
@@ -966,10 +964,10 @@ int nxplayer_setbass(FAR struct nxplayer_s *pPlayer, uint8_t level)
 #ifdef CONFIG_AUDIO_MULTI_SESSION
       cap_desc.session= pPlayer->session;
 #endif
-      cap_desc.caps.ac_len = sizeof(struct audio_caps_s);
-      cap_desc.caps.ac_type = AUDIO_TYPE_FEATURE;
-      *((uint16_t *) cap_desc.caps.ac_format) = AUDIO_FU_BASS;
-      cap_desc.caps.ac_controls[0] = level;
+      cap_desc.caps.ac_len           = sizeof(struct audio_caps_s);
+      cap_desc.caps.ac_type          = AUDIO_TYPE_FEATURE;
+      cap_desc.caps.ac_format.hw     = AUDIO_FU_BASS;
+      cap_desc.caps.ac_controls.b[0] = level;
       ioctl(pPlayer->devFd, AUDIOIOC_CONFIGURE, (unsigned long) &cap_desc);
     }
 
@@ -1018,10 +1016,10 @@ int nxplayer_settreble(FAR struct nxplayer_s *pPlayer, uint8_t level)
 #ifdef CONFIG_AUDIO_MULTI_SESSION
       cap_desc.session= pPlayer->session;
 #endif
-      cap_desc.caps.ac_len = sizeof(struct audio_caps_s);
-      cap_desc.caps.ac_type = AUDIO_TYPE_FEATURE;
-      *((uint16_t *) cap_desc.caps.ac_format) = AUDIO_FU_TREBLE;
-      cap_desc.caps.ac_controls[0] = level;
+      cap_desc.caps.ac_len           = sizeof(struct audio_caps_s);
+      cap_desc.caps.ac_type          = AUDIO_TYPE_FEATURE;
+      cap_desc.caps.ac_format.hw     = AUDIO_FU_TREBLE;
+      cap_desc.caps.ac_controls.b[0] = level;
       ioctl(pPlayer->devFd, AUDIOIOC_CONFIGURE, (unsigned long) &cap_desc);
     }
 
@@ -1065,10 +1063,10 @@ int nxplayer_setbalance(FAR struct nxplayer_s *pPlayer, uint16_t balance)
 #ifdef CONFIG_AUDIO_MULTI_SESSION
       cap_desc.session= pPlayer->session;
 #endif
-      cap_desc.caps.ac_len = sizeof(struct audio_caps_s);
-      cap_desc.caps.ac_type = AUDIO_TYPE_FEATURE;
-      *((uint16_t *) cap_desc.caps.ac_format) = AUDIO_FU_BALANCE;
-      *((uint16_t *) cap_desc.caps.ac_controls) = balance;
+      cap_desc.caps.ac_len            = sizeof(struct audio_caps_s);
+      cap_desc.caps.ac_type           = AUDIO_TYPE_FEATURE;
+      cap_desc.caps.ac_format.hw      = AUDIO_FU_BALANCE;
+      cap_desc.caps.ac_controls.hw[0] = balance;
       ioctl(pPlayer->devFd, AUDIOIOC_CONFIGURE, (unsigned long) &cap_desc);
     }
 
@@ -1268,8 +1266,8 @@ int nxplayer_setdevice(FAR struct nxplayer_s *pPlayer, FAR const char *pDevice)
   /* Save the path and format capabilities of the preferred device */
 
   strncpy(pPlayer->prefdevice, pDevice, sizeof(pPlayer->prefdevice));
-  pPlayer->prefformat = caps.ac_format[0] | (caps.ac_format[1] << 8);
-  pPlayer->preftype = caps.ac_controls[0];
+  pPlayer->prefformat = caps.ac_format.b[0] | (caps.ac_format.b[1] << 8);
+  pPlayer->preftype = caps.ac_controls.b[0];
 
   return OK;
 }
diff --git a/nuttx/audio/pcm_decode.c b/nuttx/audio/pcm_decode.c
index 45937fd12..6b46f770b 100644
--- a/nuttx/audio/pcm_decode.c
+++ b/nuttx/audio/pcm_decode.c
@@ -407,7 +407,7 @@ static int pcm_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
   if (caps->ac_subtype == AUDIO_TYPE_QUERY)
     {
-      *((uint16_t *)&caps->ac_format[0]) = (1 << (AUDIO_FMT_PCM - 1));
+      caps->ac_format.hw = (1 << (AUDIO_FMT_PCM - 1));
     }
 
   return caps->ac_len;
@@ -749,12 +749,12 @@ static int pcm_enqueuebuffer(FAR struct audio_lowerhalf_s *dev,
 
           DEBUGASSERT(priv->samprate < 65535);
 
-          caps.ac_len         = sizeof(struct audio_caps_s);
-          caps.ac_type        = AUDIO_TYPE_OUTPUT;
-          caps.ac_channels    = priv->nchannels;
+          caps.ac_len            = sizeof(struct audio_caps_s);
+          caps.ac_type           = AUDIO_TYPE_OUTPUT;
+          caps.ac_channels       = priv->nchannels;
 
-          *((uint16_t *)&caps.ac_controls[0]) = (uint16_t)priv->samprate;
-          caps.ac_controls[2] = priv->bpsamp;
+          caps.ac_controls.hw[0] = (uint16_t)priv->samprate;
+          caps.ac_controls.b[2]  = priv->bpsamp;
 
 #ifdef CONFIG_AUDIO_MULTI_SESSION
           ret = lower->ops->configure(lower, priv->session, &caps);
diff --git a/nuttx/drivers/audio/audio_null.c b/nuttx/drivers/audio/audio_null.c
index 401cf1d75..1dff793a9 100644
--- a/nuttx/drivers/audio/audio_null.c
+++ b/nuttx/drivers/audio/audio_null.c
@@ -186,12 +186,8 @@ static int null_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
   /* Fill in the caller's structure based on requested info */
 
-  caps->ac_format[0]   = 0;
-  caps->ac_format[1]   = 0;
-  caps->ac_controls[0] = 0;
-  caps->ac_controls[1] = 0;
-  caps->ac_controls[2] = 0;
-  caps->ac_controls[3] = 0;
+  caps->ac_format.hw  = 0;
+  caps->ac_controls.w = 0;
 
   switch (caps->ac_type)
     {
@@ -214,19 +210,19 @@ static int null_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
               /* The types of audio units we implement */
 
-              caps->ac_controls[0] = AUDIO_TYPE_OUTPUT | AUDIO_TYPE_FEATURE |
-                                     AUDIO_TYPE_PROCESSING;
+              caps->ac_controls.b[0] = AUDIO_TYPE_OUTPUT | AUDIO_TYPE_FEATURE |
+                                       AUDIO_TYPE_PROCESSING;
 
               break;
 
             case AUDIO_FMT_MIDI:
               /* We only support Format 0 */
 
-              caps->ac_controls[0] = AUDIO_SUBFMT_END;
+              caps->ac_controls.b[0] = AUDIO_SUBFMT_END;
               break;
 
             default:
-              caps->ac_controls[0] = AUDIO_SUBFMT_END;
+              caps->ac_controls.b[0] = AUDIO_SUBFMT_END;
               break;
           }
 
@@ -244,10 +240,10 @@ static int null_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
               /* Report the Sample rates we support */
 
-              caps->ac_controls[0] = AUDIO_SAMP_RATE_8K | AUDIO_SAMP_RATE_11K |
-                                     AUDIO_SAMP_RATE_16K | AUDIO_SAMP_RATE_22K |
-                                     AUDIO_SAMP_RATE_32K | AUDIO_SAMP_RATE_44K |
-                                     AUDIO_SAMP_RATE_48K;
+              caps->ac_controls.b[0] = AUDIO_SAMP_RATE_8K | AUDIO_SAMP_RATE_11K |
+                                       AUDIO_SAMP_RATE_16K | AUDIO_SAMP_RATE_22K |
+                                       AUDIO_SAMP_RATE_32K | AUDIO_SAMP_RATE_44K |
+                                       AUDIO_SAMP_RATE_48K;
               break;
 
             case AUDIO_FMT_MP3:
@@ -271,8 +267,8 @@ static int null_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
           {
             /* Fill in the ac_controls section with the Feature Units we have */
 
-            caps->ac_controls[0] = AUDIO_FU_VOLUME | AUDIO_FU_BASS | AUDIO_FU_TREBLE;
-            caps->ac_controls[1] = AUDIO_FU_BALANCE >> 8;
+            caps->ac_controls.b[0] = AUDIO_FU_VOLUME | AUDIO_FU_BASS | AUDIO_FU_TREBLE;
+            caps->ac_controls.b[1] = AUDIO_FU_BALANCE >> 8;
           }
         else
           {
@@ -293,14 +289,14 @@ static int null_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
               /* Provide the type of Processing Units we support */
 
-              caps->ac_controls[0] = AUDIO_PU_STEREO_EXTENDER;
+              caps->ac_controls.b[0] = AUDIO_PU_STEREO_EXTENDER;
               break;
 
             case AUDIO_PU_STEREO_EXTENDER:
 
               /* Provide capabilities of our Stereo Extender */
 
-              caps->ac_controls[0] = AUDIO_STEXT_ENABLE | AUDIO_STEXT_WIDTH;
+              caps->ac_controls.b[0] = AUDIO_STEXT_ENABLE | AUDIO_STEXT_WIDTH;
               break;
 
             default:
@@ -360,21 +356,21 @@ static int null_configure(FAR struct audio_lowerhalf_s *dev,
 
       /* Process based on Feature Unit */
 
-      switch (*((uint16_t *)caps->ac_format))
+      switch (caps->ac_format.hw)
         {
 #ifndef CONFIG_AUDIO_EXCLUDE_VOLUME
         case AUDIO_FU_VOLUME:
-          audvdbg("    Volume: %d\n", *(uint16_t *)caps->ac_controls);
+          audvdbg("    Volume: %d\n", caps->ac_controls.hw[0]);
           break;
 #endif  /* CONFIG_AUDIO_EXCLUDE_VOLUME */
 
 #ifndef CONFIG_AUDIO_EXCLUDE_TONE
         case AUDIO_FU_BASS:
-          audvdbg("    Bass: %d\n", caps->ac_controls[0]);
+          audvdbg("    Bass: %d\n", caps->ac_controls.b[0]);
           break;
 
         case AUDIO_FU_TREBLE:
-          audvdbg("    Treble: %d\n", caps->ac_controls[0]);
+          audvdbg("    Treble: %d\n", caps->ac_controls.b[0]);
           break;
 #endif  /* CONFIG_AUDIO_EXCLUDE_TONE */
 
@@ -387,8 +383,8 @@ static int null_configure(FAR struct audio_lowerhalf_s *dev,
     case AUDIO_TYPE_OUTPUT:
       audvdbg("  AUDIO_TYPE_OUTPUT:\n");
       audvdbg("    Number of channels: %u\n", caps->ac_channels);
-      audvdbg("    Sample rate:        %u\n", *(uint16_t*)&ac_controls[0]);
-      audvdbg("    Sample width:       %u\n", ac_controls[2]);
+      audvdbg("    Sample rate:        %u\n", ac_controls.hw[0]);
+      audvdbg("    Sample width:       %u\n", ac_controls.b[2]);
       break;
 
     case AUDIO_TYPE_PROCESSING:
diff --git a/nuttx/drivers/audio/vs1053.c b/nuttx/drivers/audio/vs1053.c
index 32d04df15..1ebd79ec5 100644
--- a/nuttx/drivers/audio/vs1053.c
+++ b/nuttx/drivers/audio/vs1053.c
@@ -568,12 +568,8 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
 
   /* Fill in the caller's structure based on requested info */
 
-  pCaps->ac_format[0] = 0;
-  pCaps->ac_format[1] = 0;
-  pCaps->ac_controls[0] = 0;
-  pCaps->ac_controls[1] = 0;
-  pCaps->ac_controls[2] = 0;
-  pCaps->ac_controls[3] = 0;
+  pCaps->ac_format.hw  = 0;
+  pCaps->ac_controls.w = 0;
 
   switch (pCaps->ac_type)
     {
@@ -592,7 +588,7 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
             case AUDIO_TYPE_QUERY:
               /* The input formats we can decode / accept */
 
-              *((uint16_t *) &pCaps->ac_format[0]) = 0
+              pCaps->ac_format.hw = 0
 #ifdef CONFIG_AUDIO_FORMAT_AC3
                     | (1 << (AUDIO_FMT_AC3 - 1))
 #endif
@@ -615,7 +611,7 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
 
               /* The types of audio units we implement */
 
-              pCaps->ac_controls[0] = AUDIO_TYPE_OUTPUT | AUDIO_TYPE_FEATURE |
+              pCaps->ac_controls.b[0] = AUDIO_TYPE_OUTPUT | AUDIO_TYPE_FEATURE |
                                       AUDIO_TYPE_PROCESSING;
 
               break;
@@ -626,13 +622,13 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
             case AUDIO_FMT_MIDI:
               /* We only support Format 0 */
 
-              pCaps->ac_controls[0] = AUDIO_SUBFMT_MIDI_0;
-              pCaps->ac_controls[1] = AUDIO_SUBFMT_END;
+              pCaps->ac_controls.b[0] = AUDIO_SUBFMT_MIDI_0;
+              pCaps->ac_controls.b[1] = AUDIO_SUBFMT_END;
               break;
 #endif
 
             default:
-              pCaps->ac_controls[0] = AUDIO_SUBFMT_END;
+              pCaps->ac_controls.b[0] = AUDIO_SUBFMT_END;
               break;
           }
 
@@ -650,7 +646,7 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
 
               /* Report the Sample rates we support */
 
-              pCaps->ac_controls[0] = AUDIO_SAMP_RATE_8K | AUDIO_SAMP_RATE_11K |
+              pCaps->ac_controls.b[0] = AUDIO_SAMP_RATE_8K | AUDIO_SAMP_RATE_11K |
                                       AUDIO_SAMP_RATE_16K | AUDIO_SAMP_RATE_22K |
                                       AUDIO_SAMP_RATE_32K | AUDIO_SAMP_RATE_44K |
                                       AUDIO_SAMP_RATE_48K;
@@ -686,8 +682,8 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
           {
             /* Fill in the ac_controls section with the Feature Units we have */
 
-            pCaps->ac_controls[0] = AUDIO_FU_VOLUME | AUDIO_FU_BASS | AUDIO_FU_TREBLE;
-            pCaps->ac_controls[1] = AUDIO_FU_BALANCE >> 8;
+            pCaps->ac_controls.b[0] = AUDIO_FU_VOLUME | AUDIO_FU_BASS | AUDIO_FU_TREBLE;
+            pCaps->ac_controls.b[1] = AUDIO_FU_BALANCE >> 8;
           }
         else
           {
@@ -708,14 +704,14 @@ static int vs1053_getcaps(FAR struct audio_lowerhalf_s *lower, int type,
 
               /* Provide the type of Processing Units we support */
 
-              pCaps->ac_controls[0] = AUDIO_PU_STEREO_EXTENDER;
+              pCaps->ac_controls.b[0] = AUDIO_PU_STEREO_EXTENDER;
               break;
 
             case AUDIO_PU_STEREO_EXTENDER:
 
               /* Proivde capabilities of our Stereo Extender */
 
-              pCaps->ac_controls[0] = AUDIO_STEXT_ENABLE | AUDIO_STEXT_WIDTH;
+              pCaps->ac_controls.b[0] = AUDIO_STEXT_ENABLE | AUDIO_STEXT_WIDTH;
               break;
 
             default:
@@ -777,13 +773,13 @@ static int vs1053_configure(FAR struct audio_lowerhalf_s *lower,
 
         /* Process based on Feature Unit */
 
-        switch (*((uint16_t *) pCaps->ac_format))
+        switch (pCaps->ac_format.hw)
           {
 #ifndef CONFIG_AUDIO_EXCLUDE_VOLUME
             case AUDIO_FU_VOLUME:
               /* Set the volume */
 
-              dev->volume = *((uint16_t *) pCaps->ac_controls);
+              dev->volume = pCaps->ac_controls.hw[0]);
               vs1053_setvolume(dev);
 
               break;
@@ -793,7 +789,7 @@ static int vs1053_configure(FAR struct audio_lowerhalf_s *lower,
             case AUDIO_FU_BALANCE:
               /* Set the volume */
 
-              dev->balance = *((uint16_t *) pCaps->ac_controls);
+              dev->balance = pCaps->ac_controls.hw[0]);
               vs1053_setvolume(dev);
 
               break;
@@ -805,7 +801,7 @@ static int vs1053_configure(FAR struct audio_lowerhalf_s *lower,
                * ac_controls[0] parameter.
                */
 
-              dev->bass = pCaps->ac_controls[0];
+              dev->bass = pCaps->ac_controls.b[0];
               if (dev->bass > 100)
                 dev->bass = 100;
               vs1053_setbass(dev);
@@ -814,10 +810,10 @@ static int vs1053_configure(FAR struct audio_lowerhalf_s *lower,
 
             case AUDIO_FU_TREBLE:
               /* Set the treble.  The percentage level (0-100) is in the
-               * ac_controls[0] parameter.
+               * ac_controls.b[0] parameter.
                */
 
-              dev->treble = pCaps->ac_controls[0];
+              dev->treble = pCaps->ac_controls.b[0];
               if (dev->treble > 100)
                 dev->treble = 100;
               vs1053_setbass(dev);
@@ -840,7 +836,7 @@ static int vs1053_configure(FAR struct audio_lowerhalf_s *lower,
 
         /* We only support STEREO_EXTENDER */
 
-        if (*((uint16_t *) pCaps->ac_format) == AUDIO_PU_STEREO_EXTENDER)
+        if (pCaps->ac_format.hw == AUDIO_PU_STEREO_EXTENDER)
           {
           }
 
diff --git a/nuttx/drivers/audio/wm8904.c b/nuttx/drivers/audio/wm8904.c
index a7bec06be..a1bf4a677 100644
--- a/nuttx/drivers/audio/wm8904.c
+++ b/nuttx/drivers/audio/wm8904.c
@@ -563,12 +563,9 @@ static int wm8904_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
   /* Fill in the caller's structure based on requested info */
 
-  caps->ac_format[0]   = 0;
-  caps->ac_format[1]   = 0;
-  caps->ac_controls[0] = 0;
-  caps->ac_controls[1] = 0;
-  caps->ac_controls[2] = 0;
-  caps->ac_controls[3] = 0;
+  caps->ac_format[0]  = 0;
+  caps->ac_format[1]  = 0;
+  caps->ac_controls.w = 0;
 
   switch (caps->ac_type)
     {
@@ -591,7 +588,7 @@ static int wm8904_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
               /* The types of audio units we implement */
 
-              caps->ac_controls[0] = AUDIO_TYPE_OUTPUT | AUDIO_TYPE_FEATURE |
+              caps->ac_controls.b[0] = AUDIO_TYPE_OUTPUT | AUDIO_TYPE_FEATURE |
                                      AUDIO_TYPE_PROCESSING;
 
               break;
@@ -599,11 +596,11 @@ static int wm8904_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
             case AUDIO_FMT_MIDI:
               /* We only support Format 0 */
 
-              caps->ac_controls[0] = AUDIO_SUBFMT_END;
+              caps->ac_controls.b[0] = AUDIO_SUBFMT_END;
               break;
 
             default:
-              caps->ac_controls[0] = AUDIO_SUBFMT_END;
+              caps->ac_controls.b[0] = AUDIO_SUBFMT_END;
               break;
           }
 
@@ -621,7 +618,7 @@ static int wm8904_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
               /* Report the Sample rates we support */
 
-              caps->ac_controls[0] = AUDIO_SAMP_RATE_8K | AUDIO_SAMP_RATE_11K |
+              caps->ac_controls.b[0] = AUDIO_SAMP_RATE_8K | AUDIO_SAMP_RATE_11K |
                                      AUDIO_SAMP_RATE_16K | AUDIO_SAMP_RATE_22K |
                                      AUDIO_SAMP_RATE_32K | AUDIO_SAMP_RATE_44K |
                                      AUDIO_SAMP_RATE_48K;
@@ -648,8 +645,8 @@ static int wm8904_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
           {
             /* Fill in the ac_controls section with the Feature Units we have */
 
-            caps->ac_controls[0] = AUDIO_FU_VOLUME | AUDIO_FU_BASS | AUDIO_FU_TREBLE;
-            caps->ac_controls[1] = AUDIO_FU_BALANCE >> 8;
+            caps->ac_controls.b[0] = AUDIO_FU_VOLUME | AUDIO_FU_BASS | AUDIO_FU_TREBLE;
+            caps->ac_controls.b[1] = AUDIO_FU_BALANCE >> 8;
           }
         else
           {
@@ -670,14 +667,14 @@ static int wm8904_getcaps(FAR struct audio_lowerhalf_s *dev, int type,
 
               /* Provide the type of Processing Units we support */
 
-              caps->ac_controls[0] = AUDIO_PU_STEREO_EXTENDER;
+              caps->ac_controls.b[0] = AUDIO_PU_STEREO_EXTENDER;
               break;
 
             case AUDIO_PU_STEREO_EXTENDER:
 
               /* Provide capabilities of our Stereo Extender */
 
-              caps->ac_controls[0] = AUDIO_STEXT_ENABLE | AUDIO_STEXT_WIDTH;
+              caps->ac_controls.b[0] = AUDIO_STEXT_ENABLE | AUDIO_STEXT_WIDTH;
               break;
 
             default:
@@ -748,7 +745,7 @@ static int wm8904_configure(FAR struct audio_lowerhalf_s *dev,
           {
             /* Set the volume */
 
-            uint16_t volume = *(uint16_t *)caps->ac_controls;
+            uint16_t volume = caps->ac_controls.hw[0];
             audvdbg("    Volume: %d\n", volume);
 
             if (volume >= 0 && volume <= 1000)
@@ -769,10 +766,10 @@ static int wm8904_configure(FAR struct audio_lowerhalf_s *dev,
         case AUDIO_FU_BASS:
           {
             /* Set the bass.  The percentage level (0-100) is in the
-             * ac_controls[0] parameter.
+             * ac_controls.b[0] parameter.
              */
 
-            uint8_t bass = caps->ac_controls[0];
+            uint8_t bass = caps->ac_controls.b[0];
             audvdbg("    Bass: %d\n", bass);
 
             if (bass <= 100)
@@ -789,10 +786,10 @@ static int wm8904_configure(FAR struct audio_lowerhalf_s *dev,
         case AUDIO_FU_TREBLE:
           {
             /* Set the treble.  The percentage level (0-100) is in the
-             * ac_controls[0] parameter.
+             * ac_controls.b[0] parameter.
              */
 
-            uint8_t treble = caps->ac_controls[0];
+            uint8_t treble = caps->ac_controls.b[0];
             audvdbg("    Treble: %d\n", treble);
 
             if (treble <= 100)
@@ -817,8 +814,8 @@ static int wm8904_configure(FAR struct audio_lowerhalf_s *dev,
     case AUDIO_TYPE_OUTPUT:
       audvdbg("  AUDIO_TYPE_OUTPUT:\n");
       audvdbg("    Number of channels: %u\n", caps->ac_channels);
-      audvdbg("    Sample rate:        %u\n", *(uint16_t*)&ac_controls[0]);
-      audvdbg("    Sample width:       %u\n", ac_controls[2]);
+      audvdbg("    Sample rate:        %u\n", ac_controls.hw[0]);
+      audvdbg("    Sample width:       %u\n", ac_controls.b[2]);
 #warning Missing logic
       break;
 
diff --git a/nuttx/include/nuttx/audio/audio.h b/nuttx/include/nuttx/audio/audio.h
index 0230437b7..761159d87 100644
--- a/nuttx/include/nuttx/audio/audio.h
+++ b/nuttx/include/nuttx/audio/audio.h
@@ -300,10 +300,19 @@ struct audio_caps_s
   uint8_t ac_type;          /* Capabilities (device) type */
   uint8_t ac_subtype;       /* Capabilities sub-type, if needed */
   uint8_t ac_channels;      /* Number of channels (1, 2, 5, 7) */
-  uint8_t ac_format[2];     /* Audio data format(s) for this device */
-  uint8_t ac_controls[4];   /* Device specific controls. For AUDIO_DEVICE_QUERY,
-                             * this field reports the device type supported
-                             * by this lower-half driver. */
+
+  union                     /* Audio data format(s) for this device */
+  {
+    uint8_t  b[2];
+    uint16_t hw;
+  } ac_format;
+
+  union                     /* Device specific controls. For AUDIO_DEVICE_QUERY, */
+  {                         /*   this field reports the device type supported */
+    uint8_t  b[4];          /*   by this lower-half driver. */
+    uint16_t hw[2];
+    uint32_t w;
+  } ac_controls;
 };
 
 struct audio_caps_desc_s