OMAP3 Port kernel omap gpio interface.

Port version 2.6.27 of the linux kernel's omap gpio interface to u-boot.
The orignal source is in linux/arch/arm/plat-omap/gpio.c

See doc/README.omap3 for instructions on use.

Signed-off-by: Tom Rix <Tom.Rix@windriver.com>
diff --git a/doc/README.omap3 b/doc/README.omap3
index 9ab0979..e05e816 100644
--- a/doc/README.omap3
+++ b/doc/README.omap3
@@ -84,6 +84,38 @@
 
 help
 
+Interfaces
+==========
+
+gpio
+
+To set a bit :
+
+	if (!omap_request_gpio(N)) {
+		omap_set_gpio_direction(N, 0);
+		omap_set_gpio_dataout(N, 1);
+	}
+
+To clear a bit :
+
+	if (!omap_request_gpio(N)) {
+		omap_set_gpio_direction(N, 0);
+		omap_set_gpio_dataout(N, 0);
+	}
+
+To read a bit :
+
+	if (!omap_request_gpio(N)) {
+		omap_set_gpio_direction(NULL, 1);
+		val = omap_get_gpio_datain(N);
+		omap_free_gpio(N);
+	}
+	if (val)
+		printf("GPIO N is set\n");
+	else
+		printf("GPIO N is clear\n");
+
+
 Acknowledgements
 ================