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* Text is no longer updated until a complete group has been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

1 files changed, 345 insertions, 141 deletions

diff --git a/firmware/drivers/rds.c b/firmware/drivers/rds.c
index 2f296cdbe8..731207de59 100644
--- a/firmware/drivers/rds.c
+++ b/firmware/drivers/rds.c
@@ -21,73 +21,195 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
-#include <strlcpy.h>
 #include <system.h>
 #include <kernel.h>
 #include "rds.h"
 #include "time.h"
+#include "string-extra.h"
+
+#define TIMED_OUT(tick) \
+    TIME_AFTER(current_tick, (tick))
+#define SET_TIMEOUT(tick, duration) \
+    ({ (tick) = current_tick + (duration); })
+
+/* Driver keeps strings in native character format, translating on demand */
+static char     ps_copy[9];     /* copy of final message */
+static long     ps_copy_tmo;    /* timeout to discard programme service name */
+static char     rt_copy[65];    /* copy of final message */
+static long     rt_copy_tmo;    /* time to discard radio text */
+static uint16_t pi_code;        /* current programme identifier code */
+static time_t   ct_data;        /* date/time (not robust; not essential) */
+
+/* timeout before text times out */
+#define TEXT_TIMEOUT    (30 * HZ)
+
+/* timeout before RDS is considered idle and is reset */
+#define RDS_TIMEOUT     (10 * HZ)
+static long rds_timeout;        /* timeout until rds is thought idle */
+static bool rds_active;         /* if active, timeouts are monitored */
+
+#if (CONFIG_RDS & RDS_CFG_PROCESS)
+/* timeout before group segment obsolescence */
+#define GROUP0_TIMEOUT  (2 * HZ)
+#define GROUP2_TIMEOUT  (10 * HZ)
+
+/* programme identification (not robust; not really used anyway) */
+static uint16_t pi_last;        /* previously read code */
+
+/* programme service name */
+static char ps_data[2][9];      /* round-robin driver work queue */
+static int  ps_segment;         /* next expected segment */
+static long ps_timeout;         /* timeout to receive full group */
+static int  ps_data_idx;        /* ps_data[0 or 1] */
+#define PS_DATA_INC(x) ps_data[ps_data_idx ^= (x)]
 
-// timeout before segment obsolescence
-#define PS_SEGMENT_TIMEOUT  (HZ / 2)
-#define RT_SEGMENT_TIMEOUT  (10 * HZ)
-
-/* programme identification */
-static uint16_t pi_code;
-static uint16_t pi_last;
-/* program service name */
-static char ps_data[9];
-static char ps_copy[9];
-static long ps_segment_timeout[4];
-static int ps_segment;// bitmap of received segments
 /* radio text */
-static char rt_data[65];
-static char rt_copy[65];
-static long rt_segment_timeout[16];
-static int rt_segment;// bitmap of received segments
-static int rt_abflag;
-/* date/time */
-static time_t ct_data;
-
-#ifdef RDS_ISR_PROCESSING
+static char rt_data[2][65];     /* round-robin driver work queue */
+static int  rt_segment;         /* next expected segment */
+static long rt_timeout;         /* timeout to receive full group */
+static int  rt_abflag;          /* message change flag */
+static int  rt_data_idx;        /* rt_data[0 or 1] */
+#define RT_DATA_INC(x) rt_data[rt_data_idx ^= (x)]
+#endif /* (CONFIG_RDS & RDS_CFG_PROCESS) */
+
+#if (CONFIG_RDS & RDS_CFG_ISR)
 /* Functions are called in ISR context */
 #define rds_disable_irq_save() disable_irq_save()
 #define rds_restore_irq(old) restore_irq(old)
-/* Need triple buffer so string isn't clobbered while caller is using it */
-static inline char * get_ps(void)
+#else /* !(CONFIG_RDS & RDS_CFG_ISR) */
+#define rds_disable_irq_save() 0
+#define rds_restore_irq(old) ((void)(old))
+#endif /* (CONFIG_RDS & RDS_CFG_ISR) */
+
+/* RDS code table G0 to UTF-8 translation */
+static const uint16_t rds_tbl_g0[0x100-0x20] =
 {
-    static char ps_out[9];
-    int oldlevel = rds_disable_irq_save();
-    strcpy(ps_out, ps_copy);
-    rds_restore_irq(oldlevel);
-    return ps_out;
+    /* codes 0x00 .. 0x1F are omitted because they are identities and not
+     * actually spec'ed as part of the character maps anyway */
+    /* 0       1       2       3       4       5       6       7          */
+    0x0020, 0x0021, 0x0022, 0x0023, 0x00A4, 0x0025, 0x0026, 0x0027, /* 20 */
+    0x0028, 0x0029, 0x002A, 0x002B, 0x002C, 0x002D, 0x002E, 0x002F, /* 28 */
+    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, /* 30 */
+    0x0038, 0x0039, 0x003A, 0x003B, 0x003C, 0x003D, 0x003E, 0x003F, /* 38 */
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, /* 40 */
+    0x0048, 0x0049, 0x004A, 0x004B, 0x004C, 0x004D, 0x004E, 0x004F, /* 48 */
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, /* 50 */
+    0x0058, 0x0059, 0x005A, 0x005B, 0x005B, 0x005D, 0x2015, 0x005F, /* 58 */
+    0x2016, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, /* 60 */
+    0x0068, 0x0069, 0x006A, 0x006B, 0x006C, 0x006D, 0x006E, 0x006F, /* 68 */
+    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, /* 70 */
+    0x0078, 0x0079, 0x007A, 0x007B, 0x007C, 0x007D, 0x203E, 0x0020, /* 78 */
+    0x00E1, 0x00E0, 0x00E9, 0x00E8, 0x00ED, 0x00EC, 0x00F3, 0x00F2, /* 80 */
+    0x00FA, 0x00F9, 0x00D1, 0x00C7, 0x015E, 0x00DF, 0x00A1, 0x0132, /* 88 */
+    0x00E2, 0x00E4, 0x00EA, 0x00EB, 0x00EE, 0x00EF, 0x00F4, 0x00F6, /* 90 */
+    0x00FB, 0x00FC, 0x00F1, 0x00E7, 0x015F, 0x01E7, 0x0131, 0x0133, /* 98 */
+    0x00AA, 0x03B1, 0x00A9, 0x2030, 0x01E6, 0x011B, 0x0148, 0x0151, /* A0 */
+    0x03C0, 0x20A0, 0x00A3, 0x0024, 0x2190, 0x2191, 0x2192, 0x2193, /* A8 */
+    0x00BA, 0x00B9, 0x00B2, 0x00B3, 0x00B1, 0x0130, 0x0144, 0x0171, /* B0 */
+    0x00B5, 0x00BF, 0x00F7, 0x00B0, 0x00BC, 0x00BD, 0x00BE, 0x00A7, /* B8 */
+    0x00C1, 0x00C0, 0x00C9, 0x00C8, 0x00CD, 0x00CC, 0x00D3, 0x00D2, /* C0 */
+    0x00DA, 0x00D9, 0x0158, 0x010C, 0x0160, 0x017D, 0x0110, 0x013F, /* C8 */
+    0x00C2, 0x00C4, 0x00CA, 0x00CB, 0x00CE, 0x00CF, 0x00D4, 0x00D6, /* D0 */
+    0x00DB, 0x00DC, 0x0159, 0x010D, 0x0161, 0x017E, 0x0111, 0x0140, /* D8 */
+    0x00C3, 0x00C5, 0x00C6, 0x0152, 0x0177, 0x00DD, 0x00D5, 0x00D8, /* E0 */
+    0x00DE, 0x014A, 0x0158, 0x0106, 0x015A, 0x0179, 0x0166, 0x00F0, /* E8 */
+    0x00E3, 0x00E5, 0x00E6, 0x0153, 0x0175, 0x00FD, 0x00F5, 0x00F8, /* F0 */
+    0x00FE, 0x014B, 0x0159, 0x0107, 0x015B, 0x017A, 0x0167, 0x0020, /* F8 */
+};
+
+/* could add tables G1 and G2 without much trouble */
+
+/* write one UTF-8 character; returns original 'dst' if insufficient space */
+static char * convert_rds_char(char *dst, unsigned int c, size_t dstsize)
+{
+    unsigned int u = c >= 0x20 ? (rds_tbl_g0 - 0x20)[c] : c;
+
+    if (LIKELY(u <= 0x7F)) {
+        /* U+0000 .. U+007F -> 0xxx xxxx */
+        if (dstsize > 1) {
+            *dst++ = u;
+        }
+    }
+    else if (u <= 0x7FF) {
+        /* U+0080 .. U+07FF -> 110x xxxx 10 xx xxxx */
+        if (dstsize > 2) {
+            *dst++ = 0xC0 | (u >> 6);
+            *dst++ = 0x80 | (u & 0x3F);
+        }
+    }
+    else /* if (u <= 0xFFFF) */ {
+        /* U+0800 .. U+FFFF -> 1110 xxxx 10xx xxxx 10xx xxxx */
+        if (dstsize > 3) {
+            *dst++ = 0xE0 | (u >> 12);
+            *dst++ = 0x80 | ((u >> 6) & 0x3F);
+            *dst++ = 0x80 | (u & 0x3F);
+        }
+    }
+#if 0 /* No four-byte characters are used right now */
+    else {
+        /* U+10000 .. U+10FFFF -> 11110xxx 10xx xxxx 10xx xxxx 10xx xxxx */
+        if (dstsize > 4) {
+            *dst++ = 0xF0 | (c >> 18);
+            *dst++ = 0x80 | ((c >> 12) & 0x3F);
+            *dst++ = 0x80 | ((c >> 6) & 0x3F);
+            *dst++ = 0x80 | (c & 0x3F);
+        }
+    }
+#endif /* 0 */
+    return dst;
 }
-static inline char * get_rt(void)
+
+/* Copy RDS character string with conversion to UTF-8
+ * Acts like strlcpy but won't split multibyte characters */
+static size_t copy_rds_string(char *dst, const char *src, size_t dstsize)
 {
-    static char rt_out[65];
-    int oldlevel = rds_disable_irq_save();
-    strcpy(rt_out, rt_copy);
-    rds_restore_irq(oldlevel);
-    return rt_out;
+    char *p = dst;
+    unsigned int c;
+
+    while ((c = (unsigned char)*src++)) {
+        char *q = p;
+
+        p = convert_rds_char(q, c, dstsize);
+        if (p == q) {
+            dst -= dstsize;
+            break;
+        }
+
+        dstsize -= p - q;
+    }
+
+    if (dstsize > 0) {
+        *p = '\0';
+    }
+
+    return p - dst;
+}
+
+/* indicate recent processing activity */
+static void register_activity(void)
+{
+    SET_TIMEOUT(rds_timeout, RDS_TIMEOUT);
+    rds_active  = true;
 }
-#else /* ndef RDS_ISR_PROCESSING */
-#define rds_disable_irq_save() 0
-#define rds_restore_irq(old) ((void)(old))
-static inline char * get_ps(void) { return ps_copy; }
-static inline char * get_rt(void) { return rt_copy; }
-#endif /* RDS_ISR_PROCESSING */
 
 /* resets the rds parser */
 void rds_reset(void)
 {
     int oldlevel = rds_disable_irq_save();
 
-    pi_code = 0;
-    pi_last = 0;
+    /* reset general info */
+    pi_code    = 0;
+    ct_data    = 0;
     ps_copy[0] = '\0';
-    ps_segment = 0;
     rt_copy[0] = '\0';
+    rds_active = false;
+
+#if (CONFIG_RDS & RDS_CFG_PROCESS)
+    /* reset driver info */
+    pi_last    = 0;
+    ps_segment = 0;
     rt_segment = 0;
-    ct_data = 0;
+#endif /* (CONFIG_RDS & RDS_CFG_PROCESS) */
 
     rds_restore_irq(oldlevel);
 }
@@ -98,105 +220,141 @@ void rds_init(void)
     rds_reset();
 }
 
+/* sync RDS state */
+void rds_sync(void)
+{
+    int oldlevel = rds_disable_irq_save();
+
+    if (rds_active) {
+        if (TIMED_OUT(rds_timeout)) {
+            rds_reset();
+        }
+        else {
+            if (TIMED_OUT(ps_copy_tmo)) {
+                ps_copy[0] = '\0';
+            }
+            if (TIMED_OUT(rt_copy_tmo)) {
+                rt_copy[0] = '\0';
+            }
+        }
+    }
+
+    rds_restore_irq(oldlevel);
+}
+
+#if (CONFIG_RDS & RDS_CFG_PROCESS)
 /* handles a group 0 packet, returns true if a new message was received */
-static bool handle_group0(uint16_t data[4])
+static void handle_group0(const uint16_t data[4])
 {
     int segment, pos;
-
-    /* remove obsolete segments */
-    for(int i = 0; i < 4; i++)
-        if(TIME_AFTER(current_tick, ps_segment_timeout[i]))
-            ps_segment &= ~(1 << i);
+    char *ps;
 
     segment = data[1] & 3;
 
+    if (segment == 0) {
+        ps_segment = 0;
+    }
+    else if (segment != ps_segment || TIMED_OUT(ps_timeout)) {
+        ps_segment = 0;
+        return;
+    }
+
     /* store data */
     pos = segment * 2;
-    ps_data[pos++] = (data[3] >> 8) & 0xFF;
-    ps_data[pos++] = (data[3] >> 0) & 0xFF;
-    ps_segment |= 1 << segment;
-    ps_segment_timeout[segment] = current_tick + PS_SEGMENT_TIMEOUT;
-    if (ps_segment == 0xf) {
-        ps_data[8] = '\0';
-        if (strcmp(ps_copy, ps_data) != 0) {
-            /* we got an updated message */
-            strcpy(ps_copy, ps_data);
-            return true;
-        }
+    ps = PS_DATA_INC(0);
+    ps[pos + 0] = (data[3] >> 8) & 0xFF;
+    ps[pos + 1] = (data[3] >> 0) & 0xFF;
+
+    if (++ps_segment < 4) {
+        /* don't have all segments yet */
+        SET_TIMEOUT(ps_timeout, GROUP0_TIMEOUT);
+        return;
+    }
+
+    ps[8] = '\0';
+
+    /* two messages in a row must be the same */
+    if (memcmp(ps, PS_DATA_INC(1), 8) == 0) {
+        memcpy(ps_copy, ps, 9);
+        SET_TIMEOUT(ps_copy_tmo, TEXT_TIMEOUT);
     }
-    return false;
 }
 
 /* handles a radio text characters, returns true if end-of-line found */
-static bool handle_rt(int pos, char c)
+static bool handle_rt(int *pos_p, char c)
 {
+    char *rt = RT_DATA_INC(0);
+
     switch (c) {
-    case 0x0A:
-        /* line break hint */
-        rt_data[pos] = ' ';
-        return false;
-    case 0x0D:
-        /* end of line */
-        rt_data[pos] = '\0';
+    case 0x0D:          /* end of line */
         return true;
-    default:
-        rt_data[pos] = c;
+    case 0x0A:          /* optional line break */
+    case 0x0B:          /* end of headline */
+        c = ' ';
+    default:            /* regular character */
+        rt[(*pos_p)++] = c;
+    case 0x00 ... 0x09: /* unprintable */
+    case 0x0C:
+    case 0x0E ... 0x1E:
+    case 0x1F:          /* soft hyphen */
         return false;
     }
 }
 
 /* handles a group 2 packet, returns true if a new message was received */
-static bool handle_group2(uint16_t data[4])
+static void handle_group2(const uint16_t data[4])
 {
     int abflag, segment, version, pos;
+    char *rt;
     bool done = false;
 
-    /* remove obsolete segments */
-    for(int i = 0; i < 16; i++)
-        if(TIME_AFTER(current_tick, rt_segment_timeout[i]))
-            rt_segment &= ~(1 << i);
-    
     /* reset parsing if the message type changed */
     abflag = (data[1] >> 4) & 1;
     segment = data[1] & 0xF;
-    if (abflag != rt_abflag) {
+    version = (data[1] >> 11) & 1;
+
+    if (abflag != rt_abflag || segment == 0) {
         rt_abflag = abflag;
         rt_segment = 0;
     }
-
-    rt_segment |= 1 << segment;
-    rt_segment_timeout[segment] = current_tick + RT_SEGMENT_TIMEOUT;
+    else if (segment != rt_segment || TIMED_OUT(rt_timeout)) {
+        rt_segment = 0;
+        return;
+    }
 
     /* store data */
-    version = (data[1] >> 11) & 1;
     if (version == 0) {
         pos = segment * 4;
-        done = done || handle_rt(pos++, (data[2] >> 8) & 0xFF);
-        done = done || handle_rt(pos++, (data[2] >> 0) & 0xFF);
-        done = done || handle_rt(pos++, (data[3] >> 8) & 0xFF);
-        done = done || handle_rt(pos++, (data[3] >> 0) & 0xFF);
+        done = done || handle_rt(&pos, (data[2] >> 8) & 0xFF);
+        done = done || handle_rt(&pos, (data[2] >> 0) & 0xFF);
+        done = done || handle_rt(&pos, (data[3] >> 8) & 0xFF);
+        done = done || handle_rt(&pos, (data[3] >> 0) & 0xFF);
     } else {
         pos = segment * 2;
-        done = done || handle_rt(pos++, (data[3] >> 8) & 0xFF);
-        done = done || handle_rt(pos++, (data[3] >> 0) & 0xFF);
+        done = done || handle_rt(&pos, (data[3] >> 8) & 0xFF);
+        done = done || handle_rt(&pos, (data[3] >> 0) & 0xFF);
     }
+
     /* there are two cases for completion:
      * - we got all 16 segments
-     * - we found a end of line AND we got all segments before it */
-    if (rt_segment == 0xffff || (done && rt_segment == (1 << segment) - 1)) {
-        rt_data[pos] = '\0';
-        if (strcmp(rt_copy, rt_data) != 0) {
-            /* we got an updated message */
-            strcpy(rt_copy, rt_data);
-            return true;
-        }
+     * - we found an end of line */
+    if (++rt_segment < 16 && !done) {
+        SET_TIMEOUT(rt_timeout, GROUP2_TIMEOUT);
+        return;
     }
 
-    return false;
+    rt = RT_DATA_INC(0);
+    rt[pos++] = '\0';
+
+    /* two messages in a row must be the same */
+    if (memcmp(rt, RT_DATA_INC(1), pos) == 0) {
+        memcpy(rt_copy, rt, pos);
+        SET_TIMEOUT(rt_copy_tmo, TEXT_TIMEOUT);
+    }
 }
 
 /* handles a group 4a packet (clock-time) */
-static bool handle_group4a(uint16_t data[4])
+static void handle_group4a(const uint16_t data[4])
 {
     int daycode = ((data[1] << 15) & 0x18000) |
                   ((data[2] >> 1) & 0x07FFF);
@@ -208,29 +366,30 @@ static bool handle_group4a(uint16_t data[4])
 
     if (daycode < 55927) {
         /* invalid date, before 2012-01-01 */
-        return false;
+        return;
     }
     if ((hour >= 24) || (minute >= 60)) {
         /* invalid time */
-        return false;
+        return;
     }
     if (offset_abs > 24) {
         /* invalid local time offset */
-        return false;
+        return;
     }
 
     /* convert modified julian day + time to UTC */
-    time_t seconds = (daycode - 40587) * 86400;
-    seconds += hour * 3600;
-    seconds += minute * 60;
-    seconds += ((offset_sig == 0) ? offset_abs : -offset_abs) * 1800;
-    ct_data = seconds;
-
-    return true;
+    time_t seconds = daycode - 40587;
+    if (seconds < 24854) {
+        seconds *= 86400;
+        seconds += hour * 3600;
+        seconds += minute * 60;
+        seconds += ((offset_sig == 0) ? offset_abs : -offset_abs) * 1800;
+        ct_data = seconds;
+    }
 }
 
-/* processes one rds packet, returns true if a new message was received */
-bool rds_process(uint16_t data[4])
+/* processes one rds packet */
+void rds_process(const uint16_t data[4])
 {
     int group;
 
@@ -240,53 +399,98 @@ bool rds_process(uint16_t data[4])
         pi_code = pi;
     }
     pi_last = pi;
-    
+
     /* handle rds data based on group */
     group = (data[1] >> 11) & 0x1F;
     switch (group) {
-    
+
     case 0: /* group 0A: basic info */
     case 1: /* group 0B: basic info */
-        return handle_group0(data);
-    
+        handle_group0(data);
+        break;
+
     case 4: /* group 2A: radio text */
     case 5: /* group 2B: radio text */
-        return handle_group2(data);
+        handle_group2(data);
+        break;
 
     case 8: /* group 4A: clock-time */
-        return handle_group4a(data);
-    
-    default:
+        handle_group4a(data);
         break;
     }
 
-    return false;
+    register_activity();
 }
+#endif /* (CONFIG_RDS & RDS_CFG_PROCESS) */
 
-/* TODO: The caller really should provide the buffer in order to regulate
-   access */
-
-/* returns the programme identification code */
-uint16_t rds_get_pi(void)
+#if (CONFIG_RDS & RDS_CFG_PUSH)
+/* pushes preprocesed RDS information */
+void rds_push_info(enum rds_info_id info_id, uintptr_t data, size_t size)
 {
-    return pi_code;
-}
+    switch (info_id) {
+#if 0
+    case RDS_INFO_CODETABLE:
+        /* nothing doing for now */
+        break;
+#endif
+    case RDS_INFO_PI:
+        pi_code = (uint16_t)data;
+        break;
+    case RDS_INFO_PS:
+        strmemcpy(ps_copy, (const char *)data, MIN(size, sizeof (ps_copy)-1));
+        SET_TIMEOUT(ps_copy_tmo, TEXT_TIMEOUT);
+        break;
+    case RDS_INFO_RT:
+        strmemcpy(rt_copy, (const char *)data, MIN(size, sizeof (rt_copy)-1));
+        SET_TIMEOUT(rt_copy_tmo, TEXT_TIMEOUT);
+        break;
+    case RDS_INFO_CT:
+        ct_data = (time_t)data;
+        break;
 
-/* returns the most recent valid programme service name */
-char* rds_get_ps(void)
-{
-    return get_ps();
-}
+    default:;
+    }
 
-/* returns the most recent valid RadioText message */
-char* rds_get_rt(void)
-{
-    return get_rt();
+    register_activity();
 }
+#endif /* (CONFIG_RDS & RDS_CFG_PUSH) */
 
-/* returns the most recent valid clock-time value (or 0 if invalid) */
-time_t rds_get_ct(void)
+/* read fully-processed RDS data */
+size_t rds_pull_info(enum rds_info_id info_id, uintptr_t data, size_t size)
 {
-    return ct_data;
-}
+    int oldlevel = rds_disable_irq_save();
 
+    rds_sync();
+
+    switch (info_id) {
+#if 0
+    case RDS_INFO_CODETABLE:
+        /* nothing doing for now */
+        break;
+#endif
+    case RDS_INFO_PI:
+        if (size >= sizeof (uint16_t)) {
+            *(uint16_t *)data = pi_code;
+        }
+        size = sizeof (uint16_t);
+        break;
+    case RDS_INFO_PS:
+        size = copy_rds_string((char *)data, ps_copy, size);
+        break;
+    case RDS_INFO_RT:
+        size = copy_rds_string((char *)data, rt_copy, size);
+        break;
+    case RDS_INFO_CT:
+        if (size >= sizeof (time_t)) {
+            *(time_t *)data = ct_data;
+        }
+        size = sizeof (time_t);
+        break;
+
+    default:
+        size = 0;
+    }
+
+    rds_restore_irq(oldlevel);
+    return size;
+}