Improve radio RDS driver and framework

* Remove unused bits like the radio event and simplify basic
radio interface. It can be more self-contained with rds.h only
required by radio and tuner code.

* Add post-processing to text a-la Silicon Labs AN243. The chip's
error correction can only do so much; additional checks are highly
recommended. Simply testing for two identical messages in a row
is extremely effective and I've never seen corrupted text since
doing that, even with mediocre reception.

Groups segments must arrive in order, not randomly; logic change
only accepts them in order, starting at 0.

Time readout was made a bit better but really we'd need to use
verbose mode and ensure that no errors were seen during receiving
of time and more checks would be need to have a stable PI. The
text is the important bit anyway.

* Time out of stale text.

* Text is no longer updated until a complete group has been
received, as is specified in the standard. Perhaps go back to
scrolling text lines in the radio screen?

* Add proper character conversion to UTF-8. Only the default G0
table for the moment. The other two could be added in.

* Add variants "RDS_CFG_PROCESS" and "RDS_CFG_PUSH" to allow
the option for processed RDS data to be pushed to the driver and
still do proper post-processing (only text conversion for now for
the latter).

Change-Id: I4d83f8b2e89a209a5096d15ec266477318c66925

apps/debug_menu.c

@@ -127,10 +127,6 @@
 #include "iap.h"
 #endif
 
-#ifdef HAVE_RDS_CAP
-#include "rds.h"
-#endif
-
 #include "talk.h"
 
 static const char* threads_getname(int selected_item, void *data,
@@ -2166,17 +2162,25 @@ static int radio_callback(int btn, struct gui_synclist *lists)
 #endif /* TEA5760 */
 
 #ifdef HAVE_RDS_CAP
-        simplelist_addline("PI:%04X PS:'%8s'",
-                           rds_get_pi(), rds_get_ps());
-        simplelist_addline("RT:%s",
-                           rds_get_rt());
-        time_t seconds = rds_get_ct();
+    {
+        char buf[65*4];
+        uint16_t pi;
+        time_t seconds;
+
+        tuner_get_rds_info(RADIO_RDS_NAME, buf, sizeof (buf));
+        tuner_get_rds_info(RADIO_RDS_PROGRAM_INFO, &pi, sizeof (pi));
+        simplelist_addline("PI:%04X PS:'%8s'", pi, buf);
+        tuner_get_rds_info(RADIO_RDS_TEXT, buf, sizeof (buf));
+        simplelist_addline("RT:%s", buf);
+        tuner_get_rds_info(RADIO_RDS_CURRENT_TIME, &seconds, sizeof (seconds));
+
         struct tm* time = gmtime(&seconds);
         simplelist_addline(
             "CT:%4d-%02d-%02d %02d:%02d",
             time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
             time->tm_hour, time->tm_min, time->tm_sec);
-#endif
+    }
+#endif /* HAVE_RDS_CAP */
     return ACTION_REDRAW;
 }
 static bool dbg_fm_radio(void)

apps/gui/skin_engine/skin_tokens.c

@@ -540,9 +540,11 @@ const char *get_radio_token(struct wps_token *token, int preset_offset,
 #ifdef HAVE_RDS_CAP
             return "rds";
         case SKIN_TOKEN_RDS_NAME:
-            return tuner_get_rds_info(RADIO_RDS_NAME);
+            tuner_get_rds_info(RADIO_RDS_NAME, buf, buf_size);
+            return buf;
         case SKIN_TOKEN_RDS_TEXT:
-            return tuner_get_rds_info(RADIO_RDS_TEXT);
+            tuner_get_rds_info(RADIO_RDS_TEXT, buf, buf_size);
+            return buf;
 #else
             return NULL; /* end of the SKIN_TOKEN_HAVE_RDS case */
 #endif /* HAVE_RDS_CAP */

apps/radio/radio.c

@@ -696,10 +696,6 @@ void radio_screen(void)
 
             default:
                 default_event_handler(button);
-#ifdef HAVE_RDS_CAP
-                if (tuner_get(RADIO_EVENT))
-                    update_type = SKIN_REFRESH_ALL;
-#endif
                 if (!tuner_get(RADIO_PRESENT))
                 {
 #if CONFIG_CODEC != SWCODEC && !defined(SIMULATOR)