--- /dev/null
+/*
+ * Copyright (C) 2016 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm/device.h>
+#include <mapmem.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <asm/errno.h>
+#include <asm/gpio.h>
+
+#define UNIPHIER_GPIO_PORTS_PER_BANK 8
+
+#define UNIPHIER_GPIO_REG_DATA 0 /* data */
+#define UNIPHIER_GPIO_REG_DIR 4 /* direction (1:in, 0:out) */
+
+struct uniphier_gpio_priv {
+ void __iomem *base;
+ char bank_name[16];
+};
+
+static void uniphier_gpio_offset_write(struct udevice *dev, unsigned offset,
+ unsigned reg, int value)
+{
+ struct uniphier_gpio_priv *priv = dev_get_priv(dev);
+ u32 tmp;
+
+ tmp = readl(priv->base + reg);
+ if (value)
+ tmp |= BIT(offset);
+ else
+ tmp &= ~BIT(offset);
+ writel(tmp, priv->base + reg);
+}
+
+static int uniphier_gpio_offset_read(struct udevice *dev, unsigned offset,
+ unsigned reg)
+{
+ struct uniphier_gpio_priv *priv = dev_get_priv(dev);
+
+ return !!(readl(priv->base + reg) & BIT(offset));
+}
+
+static int uniphier_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+ uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DIR, 1);
+
+ return 0;
+}
+
+static int uniphier_gpio_direction_output(struct udevice *dev, unsigned offset,
+ int value)
+{
+ uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DATA, value);
+ uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DIR, 0);
+
+ return 0;
+}
+
+static int uniphier_gpio_get_value(struct udevice *dev, unsigned offset)
+{
+ return uniphier_gpio_offset_read(dev, offset, UNIPHIER_GPIO_REG_DATA);
+}
+
+static int uniphier_gpio_set_value(struct udevice *dev, unsigned offset,
+ int value)
+{
+ uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DATA, value);
+
+ return 0;
+}
+
+static int uniphier_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+ return uniphier_gpio_offset_read(dev, offset, UNIPHIER_GPIO_REG_DIR) ?
+ GPIOF_INPUT : GPIOF_OUTPUT;
+}
+
+static const struct dm_gpio_ops uniphier_gpio_ops = {
+ .direction_input = uniphier_gpio_direction_input,
+ .direction_output = uniphier_gpio_direction_output,
+ .get_value = uniphier_gpio_get_value,
+ .set_value = uniphier_gpio_set_value,
+ .get_function = uniphier_gpio_get_function,
+};
+
+static int uniphier_gpio_probe(struct udevice *dev)
+{
+ struct uniphier_gpio_priv *priv = dev_get_priv(dev);
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ DECLARE_GLOBAL_DATA_PTR;
+ fdt_addr_t addr;
+ fdt_size_t size;
+ unsigned int tmp;
+
+ addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg",
+ &size);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ priv->base = map_sysmem(addr, size);
+ if (!priv->base)
+ return -ENOMEM;
+
+ uc_priv->gpio_count = UNIPHIER_GPIO_PORTS_PER_BANK;
+
+ tmp = (addr & 0xfff);
+
+ /* Unfortunately, there is a register hole at offset 0x90-0x9f. */
+ if (tmp > 0x90)
+ tmp -= 0x10;
+
+ snprintf(priv->bank_name, sizeof(priv->bank_name) - 1,
+ "port%d-", (tmp - 8) / 8);
+
+ uc_priv->bank_name = priv->bank_name;
+
+ return 0;
+}
+
+static int uniphier_gpio_remove(struct udevice *dev)
+{
+ struct uniphier_gpio_priv *priv = dev_get_priv(dev);
+
+ unmap_sysmem(priv->base);
+
+ return 0;
+}
+
+/* .data = the number of GPIO banks */
+static const struct udevice_id uniphier_gpio_match[] = {
+ { .compatible = "socionext,uniphier-gpio" },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(uniphier_gpio) = {
+ .name = "uniphier_gpio",
+ .id = UCLASS_GPIO,
+ .of_match = uniphier_gpio_match,
+ .probe = uniphier_gpio_probe,
+ .remove = uniphier_gpio_remove,
+ .priv_auto_alloc_size = sizeof(struct uniphier_gpio_priv),
+ .ops = &uniphier_gpio_ops,
+};