avr32: Add support for "GPIO" port mux

The "GPIO" port mux is used on AVR32 UC3 parts as well as AT32AP7200 and
all later AVR32 chips. This patch adds a driver for it, implementing the
same API as the existing portmux-pio driver but with more functionality.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
diff --git a/cpu/at32ap/portmux-gpio.c b/cpu/at32ap/portmux-gpio.c
new file mode 100644
index 0000000..9acd040
--- /dev/null
+++ b/cpu/at32ap/portmux-gpio.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2008 Atmel Corporation
+ *
+ * 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/io.h>
+#include <asm/arch/memory-map.h>
+#include <asm/arch/gpio.h>
+
+void portmux_select_peripheral(void *port, unsigned long pin_mask,
+		enum portmux_function func, unsigned long flags)
+{
+	/* Both pull-up and pull-down set means buskeeper */
+	if (flags & PORTMUX_PULL_DOWN)
+		gpio_writel(port, PDERS, pin_mask);
+	else
+		gpio_writel(port, PDERC, pin_mask);
+	if (flags & PORTMUX_PULL_UP)
+		gpio_writel(port, PUERS, pin_mask);
+	else
+		gpio_writel(port, PUERC, pin_mask);
+
+	/* Select drive strength */
+	if (flags & PORTMUX_DRIVE_LOW)
+		gpio_writel(port, ODCR0S, pin_mask);
+	else
+		gpio_writel(port, ODCR0C, pin_mask);
+	if (flags & PORTMUX_DRIVE_HIGH)
+		gpio_writel(port, ODCR1S, pin_mask);
+	else
+		gpio_writel(port, ODCR1C, pin_mask);
+
+	/* Select function */
+	if (func & PORTMUX_FUNC_B)
+		gpio_writel(port, PMR0S, pin_mask);
+	else
+		gpio_writel(port, PMR0C, pin_mask);
+	if (func & PORTMUX_FUNC_C)
+		gpio_writel(port, PMR1S, pin_mask);
+	else
+		gpio_writel(port, PMR1C, pin_mask);
+
+	/* Disable GPIO (i.e. enable peripheral) */
+	gpio_writel(port, GPERC, pin_mask);
+}
+
+void portmux_select_gpio(void *port, unsigned long pin_mask,
+		unsigned long flags)
+{
+	/* Both pull-up and pull-down set means buskeeper */
+	if (flags & PORTMUX_PULL_DOWN)
+		gpio_writel(port, PDERS, pin_mask);
+	else
+		gpio_writel(port, PDERC, pin_mask);
+	if (flags & PORTMUX_PULL_UP)
+		gpio_writel(port, PUERS, pin_mask);
+	else
+		gpio_writel(port, PUERC, pin_mask);
+
+	/* Enable open-drain mode if requested */
+	if (flags & PORTMUX_OPEN_DRAIN)
+		gpio_writel(port, ODMERS, pin_mask);
+	else
+		gpio_writel(port, ODMERC, pin_mask);
+
+	/* Select drive strength */
+	if (flags & PORTMUX_DRIVE_LOW)
+		gpio_writel(port, ODCR0S, pin_mask);
+	else
+		gpio_writel(port, ODCR0C, pin_mask);
+	if (flags & PORTMUX_DRIVE_HIGH)
+		gpio_writel(port, ODCR1S, pin_mask);
+	else
+		gpio_writel(port, ODCR1C, pin_mask);
+
+	/* Select direction and initial pin state */
+	if (flags & PORTMUX_DIR_OUTPUT) {
+		if (flags & PORTMUX_INIT_HIGH)
+			gpio_writel(port, OVRS, pin_mask);
+		else
+			gpio_writel(port, OVRC, pin_mask);
+		gpio_writel(port, ODERS, pin_mask);
+	} else {
+		gpio_writel(port, ODERC, pin_mask);
+	}
+
+	/* Enable GPIO */
+	gpio_writel(port, GPERS, pin_mask);
+}