rockchip: gpio: Add rockchip GPIO driver

This supports RK3288 at present. It does not implement functions or support
for pull up/down.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/rk_gpio.c b/drivers/gpio/rk_gpio.c
new file mode 100644
index 0000000..fbdf9f3
--- /dev/null
+++ b/drivers/gpio/rk_gpio.c
@@ -0,0 +1,123 @@
+/*
+ * (C) Copyright 2015 Google, Inc
+ *
+ * (C) Copyright 2008-2014 Rockchip Electronics
+ * Peter, Software Engineering, <superpeter.cai@gmail.com>.
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/errno.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <dt-bindings/gpio/gpio.h>
+
+enum {
+	ROCKCHIP_GPIOS_PER_BANK		= 32,
+};
+
+#define OFFSET_TO_BIT(bit)	(1UL << (bit))
+
+struct rockchip_gpio_priv {
+	struct rockchip_gpio_regs *regs;
+	char name[2];
+};
+
+static int rockchip_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+	struct rockchip_gpio_priv *priv = dev_get_priv(dev);
+	struct rockchip_gpio_regs *regs = priv->regs;
+
+	clrbits_le32(&regs->swport_ddr, OFFSET_TO_BIT(offset));
+
+	return 0;
+}
+
+static int rockchip_gpio_direction_output(struct udevice *dev, unsigned offset,
+					  int value)
+{
+	struct rockchip_gpio_priv *priv = dev_get_priv(dev);
+	struct rockchip_gpio_regs *regs = priv->regs;
+	int mask = OFFSET_TO_BIT(offset);
+
+	clrsetbits_le32(&regs->swport_dr, mask, value ? mask : 0);
+	setbits_le32(&regs->swport_ddr, mask);
+
+	return 0;
+}
+
+static int rockchip_gpio_get_value(struct udevice *dev, unsigned offset)
+{
+	struct rockchip_gpio_priv *priv = dev_get_priv(dev);
+	struct rockchip_gpio_regs *regs = priv->regs;
+
+	return readl(&regs->ext_port) & OFFSET_TO_BIT(offset);
+}
+
+static int rockchip_gpio_set_value(struct udevice *dev, unsigned offset,
+				   int value)
+{
+	struct rockchip_gpio_priv *priv = dev_get_priv(dev);
+	struct rockchip_gpio_regs *regs = priv->regs;
+	int mask = OFFSET_TO_BIT(offset);
+
+	clrsetbits_le32(&regs->swport_dr, mask, value ? mask : 0);
+
+	return 0;
+}
+
+static int rockchip_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+	return -ENOSYS;
+}
+
+static int rockchip_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
+			    struct fdtdec_phandle_args *args)
+{
+	desc->offset = args->args[0];
+	desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
+
+	return 0;
+}
+
+static int rockchip_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct rockchip_gpio_priv *priv = dev_get_priv(dev);
+	char *end;
+	int bank;
+
+	priv->regs = (struct rockchip_gpio_regs *)dev_get_addr(dev);
+	uc_priv->gpio_count = ROCKCHIP_GPIOS_PER_BANK;
+	end = strrchr(dev->name, '@');
+	bank = trailing_strtoln(dev->name, end);
+	priv->name[0] = 'A' + bank;
+	uc_priv->bank_name = priv->name;
+
+	return 0;
+}
+
+static const struct dm_gpio_ops gpio_rockchip_ops = {
+	.direction_input	= rockchip_gpio_direction_input,
+	.direction_output	= rockchip_gpio_direction_output,
+	.get_value		= rockchip_gpio_get_value,
+	.set_value		= rockchip_gpio_set_value,
+	.get_function		= rockchip_gpio_get_function,
+	.xlate			= rockchip_gpio_xlate,
+};
+
+static const struct udevice_id rockchip_gpio_ids[] = {
+	{ .compatible = "rockchip,gpio-bank" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_rockchip) = {
+	.name	= "gpio_rockchip",
+	.id	= UCLASS_GPIO,
+	.of_match = rockchip_gpio_ids,
+	.ops	= &gpio_rockchip_ops,
+	.priv_auto_alloc_size = sizeof(struct rockchip_gpio_priv),
+	.probe	= rockchip_gpio_probe,
+};