D2: Obey the SD card write-protect tab

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22596 a1c6a512-1295-4272-9138-f99709370657

firmware/target/arm/tcc780x/sd-tcc780x.c

@@ -50,6 +50,7 @@
 #define EC_TRAN_WRITE_ENTRY      9
 #define EC_TRAN_WRITE_EXIT       10
 #define EC_COMMAND               11
+#define EC_WRITE_PROTECT         12
 
 /* for compatibility */
 static long last_disk_activity = -1;
@@ -536,6 +537,12 @@ int sd_write_sectors(IF_MD2(int card_no,) unsigned long start, int count,
     const unsigned char *buf_end;
     bool aligned;
 
+    if ((card_no == CARD_NUM_SLOT) && (GPIOA & 0x10))
+    {
+        /* write protect tab set */
+        return -EC_WRITE_PROTECT;
+    }
+
     mutex_lock(&sd_mtx);
     sd_enable(true);
     led(true);