short ftdi bit bang test

Makefile

@@ -11,6 +11,11 @@ BIN_DIR = bin
 
 INCLUDES := inc
 
+#Alpine Linux ftdi include path
+INCLUDES += /usr/include/libftdi1
+LIBS := ftdi
+
+LD_FLAGS :=
 C_FLAGS := -O0 -g
 CPP_FLAGS := $(addprefix -I, $(INCLUDES))
 
@@ -27,7 +32,7 @@ all: $(TARGET)
 
 $(TARGET): $(OBJS) $(THIS_MAKEFILE)
 	@mkdir -p $(BIN_DIR)
-	$(CC) $(LD_FLAGS) $(OBJS) $(LIBS) -o $@
+	$(CC) $(C_FLAGS) $(LD_FLAGS) $(OBJS) $(addprefix -l,$(LIBS)) -o $@
 
 .PRECIOUS: $(OBJ_DIR)/%.d
 $(OBJ_DIR)/%.d: $(SRC_DIR)/%.c

src/main.c

@@ -1,10 +1,56 @@
-#include <stdio.h>
+#include <syslog.h>
+#include <ftdi.h>
 
 #include <def.h>
 
+#define LED 0x08
 int main(int argc, char *argv[])
 {
-    printf("%s\n", HELLO);
+    struct ftdi_context *ftdi;
+    int f, retval, cnt;
+    unsigned char buf[1];
 
-    return 0;
+    openlog("ftdi_gpio", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
+    setlogmask(LOG_DEBUG);
+
+    if ((ftdi = ftdi_new()) == 0) {
+        syslog(LOG_ERR, "ftdi_new failed\n");
+        return EXIT_FAILURE;
+    }
+
+    f = ftdi_usb_open(ftdi, 0x0403, 0x6001);
+
+    if (f < 0 && f != -5) {
+        syslog(LOG_ERR, "unable to open ftdi device: %d (%s)\n", f, ftdi_get_error_string(ftdi));
+        retval = 1;
+        goto done;
+    }
+
+    f = ftdi_set_bitmode(ftdi, LED, BITMODE_BITBANG);
+    if(f < 0) {
+        syslog(LOG_ERR, "unable to set bit bang mode: %d (%s)\n", f, ftdi_get_error_string(ftdi));
+        retval = 1;
+        goto done;
+    }
+
+    buf[0] = 0;
+    for(cnt = 0; cnt < 10; cnt++) {
+        buf[0] ^= LED,
+        f = ftdi_write_data(ftdi, buf, 1);
+        if(f < 0) {
+            syslog(LOG_ERR, "write failed for 0x%x, error %d (%s)\n",buf[0], f, ftdi_get_error_string(ftdi));
+            cnt = 10;
+        } else {
+            syslog(LOG_DEBUG, "set LED to: %u\n", (unsigned int)buf[0]);
+        }
+        
+        sleep(1);
+    }
+
+    ftdi_usb_close(ftdi);
+done:
+    ftdi_free(ftdi);
+    closelog();
+
+    return retval;
 }