cpu/allwinner/a10: Add functions for driving GPIO pins

Change-Id: I9473a6e574c3af02d154a7e30245f0dc0b238300
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4599
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: David Hendricks <dhendrix@chromium.org>

src/cpu/allwinner/a10/Makefile.inc

@@ -1,4 +1,5 @@
 bootblock-y	+= clock.c
+bootblock-y	+= gpio.c
 bootblock-y	+= pinmux.c
 bootblock-y	+= bootblock_media.c
 bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += uart.c

src/cpu/allwinner/a10/gpio.c

@@ -0,0 +1,98 @@
+/*
+ * Basic GPIO helpers for Allwinner CPUs
+ *
+ * Copyright (C) 2013  Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include "gpio.h"
+
+#include <arch/io.h>
+
+static struct a10_gpio *const gpio = (void *)GPIO_BASE;
+
+/**
+ * \brief Set a single output pin
+ *
+ * @param[in] port GPIO port of the pin (GPA -> GPS)
+ * @param[in] pin the pin number in the given port (1 -> 31)
+ */
+void gpio_set(u8 port, u8 pin)
+{
+	u32 reg32;
+
+	if ((port > GPS))
+		return;
+
+	reg32 = gpio_read(port);
+	reg32 |= (1 << pin);
+	gpio_write(port, reg32);
+}
+
+/**
+ * \brief Clear a single output pin
+ *
+ * @param[in] port GPIO port of the pin (GPA -> GPS)
+ * @param[in] pin the pin number in the given port (1 -> 31)
+ */
+void gpio_clear(u8 port, u8 pin)
+{
+	u32 reg32;
+	if ((port > GPS))
+		return;
+
+	reg32 = gpio_read(port);
+	reg32 &= ~(1 << pin);
+	gpio_write(port, reg32);
+}
+
+/**
+ * \brief Get the status of a single input pin
+ *
+ * @param[in] port GPIO port of the pin (GPA -> GPS)
+ * @param[in] pin the pin number in the given port (1 -> 31)
+ * @return 1 if the pin is high, or 0 if the pin is low
+ */
+int gpio_get(u8 port, u8 pin)
+{
+	if ((port > GPS))
+		return 0;
+
+	return (gpio_read(port) & (1 << pin)) ? 1 : 0;
+}
+
+/**
+ * \brief Write to a GPIO port
+ *
+ * Write the state of all output pins in the GPIO port. This only affects pins
+ * configured as output pins.
+ *
+ * @param[in] port GPIO port of the pin (GPA -> GPS)
+ * @param[in] value 32-bit mask indicating which pins to set. For a set bit, the
+ *                  corresponding pin will be set. Otherwise, it will be cleared
+ */
+void gpio_write(u8 port, u32 val)
+{
+	if ((port > GPS))
+		return;
+
+	write32(val, &gpio->port[port].dat);
+}
+
+/**
+ * \brief Write to a GPIO port
+ *
+ * Read the state of all input pins in the GPIO port.
+ *
+ * @param[in] port GPIO port of the pin (GPA -> GPS)
+ * @return 32-bit mask indicating which pins are high. For each set bit, the
+ *         corresponding pin is high. The value of bits corresponding to pins
+ *         which are not configured as inputs is undefined.
+ */
+u32 gpio_read(u8 port)
+{
+	if ((port > GPS))
+		return 0;
+
+	return read32(&gpio->port[port].dat);
+}

src/cpu/allwinner/a10/gpio.h

@@ -50,6 +50,14 @@ struct a10_gpio {
 	u32 sdr_pad_pul;
 } __attribute__ ((packed));
 
+/* gpio.c */
+void gpio_set(u8 port, u8 pin);
+void gpio_clear(u8 port, u8 pin);
+int gpio_get(u8 port, u8 pin);
+void gpio_write(u8 port, u32 val);
+u32 gpio_read(u8 port);
+
+/* pinmux.c */
 void gpio_set_pin_func(u8 port, u8 pin, u8 pad_func);
 void gpio_set_multipin_func(u8 port, u32 pin_mask, u8 pad_func);