altos: Add support for reflashing skytraq GPS chips

This simply switches the skytraq port to 115200 baud and then
essentially connects it directly to the USB port by forwarding bytes
in both directions.

Once started, the only way out is to reboot the board.

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 d80da97ca6ea44a2cd2828380afa55eda19f0a0b..b7dc0a86bbff38c393a81b3a385ead7adb43b591 100644 (file)
--- a/src/drivers/ao_gps_skytraq.c
+++ b/src/drivers/ao_gps_skytraq.c
@@ -21,6 +21,7 @@
 
 #ifndef ao_gps_getchar
 #define ao_gps_getchar ao_serial1_getchar
+#define ao_gps_fifo    ao_serial1_rx_fifo
 #endif
 
 #ifndef ao_gps_putchar
@@ -453,6 +454,8 @@ ao_gps_nmea_parse(void)
        }
 }
 
+static uint8_t ao_gps_updating;
+
 void
 ao_gps(void) __reentrant
 {
@@ -468,6 +471,13 @@ ao_gps(void) __reentrant
                if (ao_gps_getchar() == '$') {
                        ao_gps_nmea_parse();
                }
+#ifndef AO_GPS_TEST
+               while (ao_gps_updating) {
+                       ao_usb_putchar(ao_gps_getchar());
+                       if (ao_fifo_empty(ao_gps_fifo))
+                               flush();
+               }
+#endif
        }
 }
 
@@ -492,8 +502,29 @@ gps_dump(void) __reentrant
        ao_mutex_put(&ao_gps_mutex);
 }
 
+static __code uint8_t ao_gps_115200[] = {
+       SKYTRAQ_MSG_3(5,0,5,0)  /* Set to 115200 baud */
+};
+
+static void
+gps_update(void) __reentrant
+{
+       ao_gps_updating = 1;
+       ao_task_minimize_latency = 1;
+#if HAS_ADC
+       ao_timer_set_adc_interval(0);
+#endif
+       ao_skytraq_sendstruct(ao_gps_115200);
+       ao_gps_set_speed(AO_SERIAL_SPEED_115200);
+
+       /* It's a binary protocol; abandon attempts to escape */
+       for (;;)
+               ao_gps_putchar(ao_usb_getchar());
+}
+
 __code struct ao_cmds ao_gps_cmds[] = {
        { gps_dump,     "g\0Display GPS" },
+       { gps_update,   "U\0Update GPS firmware" },
        { 0, NULL },
 };