sonynwza10/a20: enable pcm frequency selection

Change-Id: I335fcdbb652253e777d0d7406545d0d44d98f4f0

firmware/drivers/audio/nwzlinux-codec.c

@@ -84,6 +84,15 @@ numid=4,iface=MIXER,name='Output Switch'
   ; Item #2 'LineFixed'
   ; Item #3 'Speaker'
   : values=0
+numid=6,iface=MIXER,name='Sampling Rate'
+  ; type=ENUMERATED,access=rw------,values=1,items=6
+  ; Item #0 '44100'
+  ; Item #1 '48000'
+  ; Item #2 '88200'
+  ; Item #3 '96000'
+  ; Item #4 '176400'
+  ; Item #5 '192000'
+  : values=0
 */
 
 /* List of various codecs used by Sony */
@@ -111,6 +120,8 @@ static int fd_noican;
 static int fd_hw;
 /* Codec */
 static enum nwz_codec_t nwz_codec;
+/* does the code support setting the sample rate? */
+static bool has_sample_rate;
 
 static enum nwz_codec_t find_codec(void)
 {
@@ -284,6 +295,8 @@ void audiohw_preinit(void)
     alsa_controls_set_enum("Output Switch", "Headphone");
     /* unmute */
     alsa_controls_set_bool("CODEC Mute Switch", false);
+    /* sample rate */
+    has_sample_rate = alsa_has_control("Sampling Rate");
 
     /* init noican */
     noican_init();
@@ -381,5 +394,11 @@ void audiohw_close(void)
 
 void audiohw_set_frequency(int fsel)
 {
-    (void) fsel;
+    if(has_sample_rate)
+    {
+        /* it's slightly annoying that Sony put the value in an enum with strings... */
+        char freq_str[16];
+        sprintf(freq_str, "%d", fsel);
+        alsa_controls_set_enum("Sampling Rate", freq_str);
+    }
 }

firmware/export/config/sonynwzlinux.h

@@ -65,6 +65,12 @@
 /* There is no hardware tone control */
 #define HAVE_SW_TONE_CONTROLS
 
+/* The A15 and A25 support more sampling rates, in fact they support crazy high bit-rates such
+ * as 176.4 and 192 kHz but Rockbox does not support those */
+#if defined(SONY_NWZA10) || defined(SONY_NWA20)
+#define HW_SAMPR_CAPS   (SAMPR_CAP_44 | SAMPR_CAP_48 | SAMPR_CAP_88 | SAMPR_CAP_96)
+#endif
+
 /* KeyPad configuration for plugins */
 #define CONFIG_KEYPAD SONY_NWZ_PAD
 #define HAS_BUTTON_HOLD

firmware/target/hosted/alsa-controls.c

@@ -72,6 +72,15 @@ bool alsa_controls_find(snd_ctl_elem_id_t *id, const char *name)
     return false;
 }
 
+bool alsa_has_control(const char *name)
+{
+    snd_ctl_elem_id_t *id;
+    /* allocate things on stack */
+    snd_ctl_elem_id_alloca(&id);
+    /* find control */
+    return alsa_controls_find(id, name);
+}
+
 /* find a control element enum index by name, return -1 if not found */
 int alsa_controls_find_enum(const char *name, const char *enum_name)
 {

firmware/target/hosted/alsa-controls.h

@@ -34,6 +34,8 @@ void alsa_controls_close(void);
 /* find a control element ID by name, return false of not found, the id needs
  * to be allocated */
 bool alsa_controls_find(snd_ctl_elem_id_t *id, const char *name);
+/* check wether a control exists */
+bool alsa_has_control(const char *name);
 /* find a control element enum index by name, return -1 if not found */
 int alsa_controls_find_enum(const char *name, const char *enum_name);
 /* set a control, potentially supports several values */

firmware/target/hosted/pcm-alsa.c

@@ -479,6 +479,10 @@ static void pcm_dma_apply_settings_nolock(void)
 {
     snd_pcm_drop(handle);
     set_hwparams(handle, pcm_sampr);
+#if defined(HAVE_NWZ_LINUX_CODEC)
+    /* Sony NWZ linux driver uses a nonstandard mecanism to set the sampling rate */
+    audiohw_set_frequency(pcm_sampr);
+#endif
 }
 
 void pcm_dma_apply_settings(void)