altos: Shrink Skytraq NMEA parsing - common nmea_finish code

This shares the checksum testing across all three lines, saving
another 103 bytes.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/drivers/ao_gps_skytraq.c b/src/drivers/ao_gps_skytraq.c
index dd8d70ab67cf2d5acb28b1148a4d37f9e6440564..1d457a1fbf60dabb835fd3ed0f216a10e391dc55 100644 (file)
--- a/src/drivers/ao_gps_skytraq.c
+++ b/src/drivers/ao_gps_skytraq.c
@@ -191,7 +191,27 @@ ao_gps_parse_flag(char no_c, char yes_c)
 }
 
 static void
-ao_nmea_gga()
+ao_nmea_finish(void)
+{
+       char c;
+       /* Skip remaining fields */
+       for (;;) {
+               c = ao_gps_char;
+               if (c == '*' || c == '\n' || c == '\r')
+                       break;
+               ao_gps_lexchar();
+               ao_gps_skip_field();
+       }
+       if (c == '*') {
+               uint8_t cksum = ao_gps_cksum ^ '*';
+               if (cksum != ao_gps_hex())
+                       ao_gps_error = 1;
+       } else
+               ao_gps_error = 1;
+}
+
+static void
+ao_nmea_gga(void)
 {
        uint8_t i;
 
@@ -260,17 +280,8 @@ ao_nmea_gga()
        ao_gps_next.altitude = ao_gps_decimal(0xff);
        ao_gps_skip_field();    /* skip any fractional portion */
 
-       /* Skip remaining fields */
-       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
-               ao_gps_lexchar();
-               ao_gps_skip_field();
-       }
-       if (ao_gps_char == '*') {
-               uint8_t cksum = ao_gps_cksum ^ '*';
-               if (cksum != ao_gps_hex())
-                       ao_gps_error = 1;
-       } else
-               ao_gps_error = 1;
+       ao_nmea_finish();
+
        if (!ao_gps_error) {
                ao_mutex_get(&ao_gps_mutex);
                ao_gps_tick = ao_gps_next_tick;
@@ -325,13 +336,9 @@ ao_nmea_gsv(void)
                                ao_gps_tracking_next.channels = i + 1;
                }
        }
-       if (ao_gps_char == '*') {
-               uint8_t cksum = ao_gps_cksum ^ '*';
-               if (cksum != ao_gps_hex())
-                       ao_gps_error = 1;
-       }
-       else
-               ao_gps_error = 1;
+
+       ao_nmea_finish();
+
        if (ao_gps_error)
                ao_gps_tracking_next.channels = 0;
        else if (done) {
@@ -380,17 +387,9 @@ ao_nmea_rmc(void)
        a = ao_gps_decimal(2);
        c = ao_gps_decimal(2);
        i = ao_gps_decimal(2);
-       /* Skip remaining fields */
-       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
-               ao_gps_lexchar();
-               ao_gps_skip_field();
-       }
-       if (ao_gps_char == '*') {
-               uint8_t cksum = ao_gps_cksum ^ '*';
-               if (cksum != ao_gps_hex())
-                       ao_gps_error = 1;
-       } else
-               ao_gps_error = 1;
+
+       ao_nmea_finish();
+
        if (!ao_gps_error) {
                ao_gps_next.year = i;
                ao_gps_next.month = c;