ZOOM2 Add support for debug board detection.

The logicpd web site is a good source for general information on this board.
Please start looking here if the below links are broken.
http://www.logicpd.com

This is a pdf of the product
http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf

This is a pdf of the product quick start guide.
The debug board is described here.
http://support.logicpd.com/downloads/1165/

This is a wiki showing the debug board in use
https://omapzoom.org/gf/project/omapzoom/wiki/?pagename=GettingStartedWithZoomII_AKA_OMAP34XII_MDP

The zoom2 has an auxillary board that contains the serial, net, jtag and
battery simulator.  This change supports a runtime check if the debug board is
connected.

Signed-off-by: Tom Rix <Tom.Rix@windriver.com>

board/omap3/zoom2/Makefile

@@ -25,7 +25,8 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)lib$(BOARD).a
 
-COBJS	:= zoom2.o
+COBJS	:= zoom2.o \
+	debug_board.o
 
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))

board/omap3/zoom2/debug_board.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2009 Wind River Systems, Inc.
+ * Tom Rix <Tom.Rix@windriver.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+#include <common.h>
+#include <asm/arch/cpu.h>
+#include <asm/io.h>
+#include <asm/arch/mux.h>
+#include <asm/arch/gpio.h>
+
+#define DEBUG_BOARD_CONNECTED		1
+#define DEBUG_BOARD_NOT_CONNECTED	0
+
+static int debug_board_connected = DEBUG_BOARD_CONNECTED;
+
+static void zoom2_debug_board_detect (void)
+{
+	int val = 0;
+
+	if (!omap_request_gpio(158)) {
+		/*
+		 * GPIO to query for debug board
+		 * 158 db board query
+		 */
+		omap_set_gpio_direction(158, 1);
+		val = omap_get_gpio_datain(158);
+		omap_free_gpio(158);
+	}
+
+	if (!val)
+		debug_board_connected = DEBUG_BOARD_NOT_CONNECTED;
+}
+
+int zoom2_debug_board_connected (void)
+{
+	static int first_time = 1;
+
+	if (first_time) {
+		zoom2_debug_board_detect ();
+		first_time = 0;
+	}
+	return debug_board_connected;
+}