Mods tmk_firmware to configure the special function key mode on Omnikey keyboards

tmk_ps2usb_omnikey_sfset.diff

diff --git a/converter/ps2_usb/matrix.c b/converter/ps2_usb/matrix.c
index c441a89b..bb14b9cd 100644
--- a/converter/ps2_usb/matrix.c
+++ b/converter/ps2_usb/matrix.c
@@ -25,6 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "host.h"
 #include "led.h"
 #include "matrix.h"
+#include "timer.h"
 
 
 static void matrix_make(uint8_t code);
@@ -64,8 +65,25 @@ static uint8_t matrix[MATRIX_ROWS];
 #define PRINT_SCREEN   (0xFC)
 #define PAUSE          (0xFE)
 
+// Set Special Function Keys for Northgate Omnikey Keyboards
+#define SFSET          (0xE9)
+
 static bool is_modified = false;
 
+static bool sf_set_ran = false;
+static uint16_t start_time_in_millis = 0;
+
+/**
+ * Set Special Function key mode for Northgate Omnikey keyboards
+ * 
+ * @param mode 0 = normal, 1 = shift, 2 = ctrl, 4 = alt
+ */
+void sf_set(uint8_t mode)
+{
+    // _delay_ms(500);
+    ps2_host_send(SFSET);
+    ps2_host_send(mode);
+}
 
 void matrix_init(void)
 {
@@ -74,7 +92,7 @@ void matrix_init(void)
 
     // initialize matrix state: all keys off
     for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
-
+    start_time_in_millis = timer_read();
     return;
 }
 
@@ -143,7 +161,6 @@ void matrix_init(void)
  */
 uint8_t matrix_scan(void)
 {
-
     // scan code reading states
     static enum {
         INIT,
@@ -203,9 +220,11 @@ uint8_t matrix_scan(void)
                         break;
                     case 0xAA:  // Self-test passed
                     case 0xFC:  // Self-test failed
+                    case 0xFD:  // Self-test failed
                         printf("BAT %s\n", (code == 0xAA) ? "OK" : "NG");
                         led_set(host_keyboard_leds());
                         state = INIT;
+                        sf_set(1);
                         break;
                     default:    // normal key make
                         if (code < 0x80) {
@@ -379,6 +398,17 @@ uint8_t matrix_scan(void)
         xprintf("Resend: %02X\n", ret);
     }
 */
+    // Run SFSET two seconds after matrix started being scanned
+    
+    if (!sf_set_ran)
+    {
+        if (timer_read() > start_time_in_millis + 2000)
+        {
+            sf_set(1);
+            sf_set_ran = true;
+        }
+    }
+    
     return 1;
 }