3 files changed, 72 insertions, 3 deletions

diff --git a/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
index 39a2cdab04..e0457e367a 100644
--- a/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
@@ -23,8 +23,12 @@
 #include "system.h"
 #include "mc13783.h"
 #include "iomuxc-imx31.h"
+#include "gpio-imx31.h"
 #include "i2c-imx31.h"
 #include "fmradio_i2c.h"
+#include "thread.h"
+#include "rds.h"
+#include "tuner.h"
 
 static struct i2c_node si4700_i2c_node =
 {
@@ -117,7 +121,57 @@ int fmradio_i2c_read(unsigned char address, unsigned char* buf, int count)
     return 0;
 }
 
-int si4700_st(void)
+bool si4700_st(void)
 {
     return (GPIO1_DR & (1 << 28)) >> 28;
 }
+
+
+/* Low-level RDS Support */
+static struct semaphore rds_sema;
+static uint32_t rds_stack[DEFAULT_STACK_SIZE/sizeof(uint32_t)];
+
+/* RDS GPIO interrupt handler */
+void si4700_stc_rds_event(void)
+{
+    /* read and clear the interrupt */
+    SI4700_GPIO_STC_RDS_ISR = (1ul << SI4700_GPIO_STC_RDS_LINE);
+    semaphore_release(&rds_sema);
+}
+
+/* Called with on=true after full radio power up, and with on=false before
+   powering down */
+void si4700_rds_powerup(bool on)
+{
+    gpio_disable_event(SI4700_STC_RDS_EVENT_ID);
+
+    if (on)
+    {
+        SI4700_GPIO_STC_RDS_ISR = (1ul << SI4700_GPIO_STC_RDS_LINE);
+        gpio_enable_event(SI4700_STC_RDS_EVENT_ID);
+    }
+}
+
+/* Captures RDS data and processes it */
+/* Use of a thread here is likely temporary */
+static void NORETURN_ATTR rds_thread(void)
+{
+    uint16_t rds_data[4];
+
+    while (1)
+    {
+        semaphore_wait(&rds_sema, TIMEOUT_BLOCK);
+
+        if (si4700_rds_read_raw(rds_data) && rds_process(rds_data))
+            si4700_rds_set_event();
+    }
+}
+
+/* One-time RDS init at startup */
+void si4700_rds_init(void)
+{
+    semaphore_init(&rds_sema, 1, 0);
+    rds_init();
+    create_thread(rds_thread, rds_stack, sizeof(rds_stack), 0, "rds"
+                  IF_PRIO(, PRIORITY_REALTIME) IF_COP(, CPU));    
+}
diff --git a/firmware/target/arm/imx31/gigabeat-s/gpio-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/gpio-gigabeat-s.c
index f4402d5617..e6bbb2345d 100644
--- a/firmware/target/arm/imx31/gigabeat-s/gpio-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/gpio-gigabeat-s.c
@@ -39,5 +39,12 @@ const struct gpio_event gpio1_events[] =
         .mask     = 1 << MC13783_GPIO_LINE,
         .sense    = GPIO_SENSE_HIGH_LEVEL,
         .callback = mc13783_event,
-    }
+    },
+    /* Generates a 5ms low pulse on the line - detect the falling edge */
+    [SI4700_STC_RDS_EVENT_ID] =
+    {
+        .mask     = 1 << SI4700_GPIO_STC_RDS_LINE,
+        .sense    = GPIO_SENSE_FALLING,
+        .callback = si4700_stc_rds_event,
+    },
 };
diff --git a/firmware/target/arm/imx31/gigabeat-s/gpio-target.h b/firmware/target/arm/imx31/gigabeat-s/gpio-target.h
index 2eea27c3be..4903d0f631 100644
--- a/firmware/target/arm/imx31/gigabeat-s/gpio-target.h
+++ b/firmware/target/arm/imx31/gigabeat-s/gpio-target.h
@@ -29,6 +29,12 @@
 #define MC13783_GPIO_ISR    GPIO1_ISR
 #define MC13783_GPIO_LINE   31
 
+/* SI4700 GPIO STC/RDS pin info for this target */
+#define SI4700_GPIO_STC_RDS_IMR     GPIO1_IMR
+#define SI4700_GPIO_STC_RDS_NUM     GPIO1_NUM
+#define SI4700_GPIO_STC_RDS_ISR     GPIO1_ISR
+#define SI4700_GPIO_STC_RDS_LINE    27
+
 #define GPIO1_INT_PRIO      INT_PRIO_DEFAULT
 
 /* Declare event indexes in priority order in a packed array */
@@ -36,7 +42,8 @@ enum gpio_event_ids
 {
     /* GPIO1 event IDs */
     MC13783_EVENT_ID = GPIO1_EVENT_FIRST,
-    GPIO1_NUM_EVENTS = 1,
+    SI4700_STC_RDS_EVENT_ID,
+    GPIO1_NUM_EVENTS = 2,
     /* GPIO2 event IDs */
     /* none defined */
     /* GPIO3 event IDs */
@@ -44,5 +51,6 @@ enum gpio_event_ids
 };
 
 void mc13783_event(void);
+void si4700_stc_rds_event(void);
 
 #endif /* GPIO_TARGET_H */