gpio: add GPIO controller driver for MediaTek MT7620 SoC

This patch adds GPIO controller driver for MediaTek MT7620 SoC

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

drivers/gpio/Kconfig

@@ -471,6 +471,14 @@ config MPC83XX_SPISEL_BOOT
 
 	  This pin is typically used as spi chip select to a spi nor flash.
 
+config MT7620_GPIO
+	bool "MediaTek MT7620 GPIO driver"
+	depends on DM_GPIO && SOC_MT7620
+	default y
+	help
+	  Device model driver for GPIO controller present in MediaTek MT7620
+	  and earlier SoCs.
+
 config MT7621_GPIO
 	bool "MediaTek MT7621 GPIO driver"
 	depends on DM_GPIO && SOC_MT7628

drivers/gpio/Makefile

@@ -64,6 +64,7 @@ obj-$(CONFIG_MVEBU_GPIO)	+= mvebu_gpio.o
 obj-$(CONFIG_MSM_GPIO)		+= msm_gpio.o
 obj-$(CONFIG_$(SPL_)PCF8575_GPIO)	+= pcf8575_gpio.o
 obj-$(CONFIG_PM8916_GPIO)	+= pm8916_gpio.o
+obj-$(CONFIG_MT7620_GPIO)	+= mt7620_gpio.o
 obj-$(CONFIG_MT7621_GPIO)	+= mt7621_gpio.o
 obj-$(CONFIG_MSCC_SGPIO)	+= mscc_sgpio.o
 obj-$(CONFIG_NX_GPIO)		+= nx_gpio.o

drivers/gpio/mt7620_gpio.c

@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ *
+ * GPIO controller driver for MediaTek MT7620 SoC
+ */
+
+#include <dm.h>
+#include <errno.h>
+#include <dm/device_compat.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <asm/gpio.h>
+
+enum mt7620_regs {
+	GPIO_REG_DATA,
+	GPIO_REG_DIR,
+	GPIO_REG_SET,
+	GPIO_REG_CLR,
+
+	__GPIO_REG_MAX
+};
+
+struct mt7620_gpio_priv {
+	void __iomem *base;
+	u32 regs[__GPIO_REG_MAX];
+	u32 count;
+};
+
+static int mt7620_gpio_get_value(struct udevice *dev, unsigned int offset)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+
+	return !!(readl(priv->base + priv->regs[GPIO_REG_DATA]) & BIT(offset));
+}
+
+static int mt7620_gpio_set_value(struct udevice *dev, unsigned int offset,
+				 int value)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+	u32 reg;
+
+	reg = value ? priv->regs[GPIO_REG_SET] : priv->regs[GPIO_REG_CLR];
+
+	writel(BIT(offset), priv->base + reg);
+
+	return 0;
+}
+
+static int mt7620_gpio_direction_input(struct udevice *dev, unsigned int offset)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+
+	clrbits_32(priv->base + priv->regs[GPIO_REG_DIR], BIT(offset));
+
+	return 0;
+}
+
+static int mt7620_gpio_direction_output(struct udevice *dev,
+					unsigned int offset, int value)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+
+	/* Set value first */
+	mt7620_gpio_set_value(dev, offset, value);
+
+	setbits_32(priv->base + priv->regs[GPIO_REG_DIR], BIT(offset));
+
+	return 0;
+}
+
+static int mt7620_gpio_get_function(struct udevice *dev, unsigned int offset)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+
+	return (readl(priv->base + priv->regs[GPIO_REG_DIR]) & BIT(offset)) ?
+	       GPIOF_OUTPUT : GPIOF_INPUT;
+}
+
+static const struct dm_gpio_ops mt7620_gpio_ops = {
+	.direction_input	= mt7620_gpio_direction_input,
+	.direction_output	= mt7620_gpio_direction_output,
+	.get_value		= mt7620_gpio_get_value,
+	.set_value		= mt7620_gpio_set_value,
+	.get_function		= mt7620_gpio_get_function,
+};
+
+static int mt7620_gpio_probe(struct udevice *dev)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	const char *name;
+
+	name = dev_read_string(dev, "mediatek,bank-name");
+	if (!name)
+		name = dev->name;
+
+	uc_priv->gpio_count = priv->count;
+	uc_priv->bank_name = name;
+
+	return 0;
+}
+
+static int mt7620_gpio_of_to_plat(struct udevice *dev)
+{
+	struct mt7620_gpio_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	priv->base = dev_remap_addr_index(dev, 0);
+	if (!priv->base) {
+		dev_err(dev, "mt7620_gpio: unable to map registers\n");
+		return -EINVAL;
+	}
+
+	ret = dev_read_u32(dev, "mediatek,gpio-num", &priv->count);
+	if (ret) {
+		dev_err(dev, "mt7620_gpio: failed to get GPIO count\n");
+		return -EINVAL;
+	}
+
+	ret = dev_read_u32_array(dev, "mediatek,register-map", priv->regs,
+				 __GPIO_REG_MAX);
+	if (ret) {
+		dev_err(dev, "mt7620_gpio: unable to get register map\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id mt7620_gpio_ids[] = {
+	{ .compatible = "mediatek,mt7620-gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(mt7620_gpio) = {
+	.name	= "mt7620_gpio",
+	.id	= UCLASS_GPIO,
+	.ops	= &mt7620_gpio_ops,
+	.of_match = mt7620_gpio_ids,
+	.probe	= mt7620_gpio_probe,
+	.of_to_plat = mt7620_gpio_of_to_plat,
+	.priv_auto = sizeof(struct mt7620_gpio_priv),
+};