ARM : Add GPIO Driver and IOMUX definition for S3C2440

It's now possible to use the gpio driver interface
for s3c2440. This patch add iomux definitions too.

Signed-off-by: Gabriel Huau <contact@huau-gabriel.fr>
diff --git a/drivers/gpio/s3c2440_gpio.c b/drivers/gpio/s3c2440_gpio.c
new file mode 100644
index 0000000..43bbf11
--- /dev/null
+++ b/drivers/gpio/s3c2440_gpio.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2012
+ * Gabriel Huau <contact@huau-gabriel.fr>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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/s3c2440.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+#define GPIO_INPUT  0x0
+#define GPIO_OUTPUT 0x1
+
+/* 0x4 means that we want DAT and not CON register */
+#define GPIO_PORT(x)	((((x) >> 5) & 0x3) + 0x4)
+#define GPIO_BIT(x)		((x) & 0x3f)
+
+/*
+ * It's how we calculate the full port address
+ * We have to get the number of the port + 1 (Port A is at 0x56000001 ...)
+ * We move it at the second digit, and finally we add 0x4 because we want
+ * to modify GPIO DAT and not CON
+ */
+#define GPIO_FULLPORT(x) (S3C24X0_GPIO_BASE | ((GPIO_PORT(gpio) + 1) << 1))
+
+int gpio_set_value(unsigned gpio, int value)
+{
+	unsigned l = readl(GPIO_FULLPORT(gpio));
+	unsigned bit;
+	unsigned port = GPIO_FULLPORT(gpio);
+
+	/*
+	 * All GPIO Port have a configuration on
+	 * 2 bits excepted the first GPIO (A) which
+	 * have only 1 bit of configuration.
+	 */
+	if (!GPIO_PORT(gpio))
+		bit = (0x1 << GPIO_BIT(gpio));
+	else
+		bit = (0x3 << GPIO_BIT(gpio));
+
+	if (value)
+		l |= bit;
+	else
+		l &= ~bit;
+
+	return writel(port, l);
+}
+
+int gpio_get_value(unsigned gpio)
+{
+	unsigned l = readl(GPIO_FULLPORT(gpio));
+
+	if (GPIO_PORT(gpio) == 0) /* PORT A */
+		return (l >> GPIO_BIT(gpio)) & 0x1;
+	return (l >> GPIO_BIT(gpio)) & 0x3;
+}
+
+int gpio_request(unsigned gpio, const char *label)
+{
+	return 0;
+}
+
+int gpio_free(unsigned gpio)
+{
+	return 0;
+}
+
+int gpio_direction_input(unsigned gpio)
+{
+	return writel(GPIO_FULLPORT(gpio), GPIO_INPUT << GPIO_BIT(gpio));
+}
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+	writel(GPIO_FULLPORT(gpio), GPIO_OUTPUT << GPIO_BIT(gpio));
+	return gpio_set_value(gpio, value);
+}