v4.19.13 snapshot.
diff --git a/arch/mips/ar7/gpio.c b/arch/mips/ar7/gpio.c
new file mode 100644
index 0000000..4eee7e9
--- /dev/null
+++ b/arch/mips/ar7/gpio.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
+ * Copyright (C) 2009-2010 Florian Fainelli <florian@openwrt.org>
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/gpio.h>
+
+#include <asm/mach-ar7/ar7.h>
+
+#define AR7_GPIO_MAX 32
+#define TITAN_GPIO_MAX 51
+
+struct ar7_gpio_chip {
+	void __iomem		*regs;
+	struct gpio_chip	chip;
+};
+
+static int ar7_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_in = gpch->regs + AR7_GPIO_INPUT;
+
+	return !!(readl(gpio_in) & (1 << gpio));
+}
+
+static int titan_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_in0 = gpch->regs + TITAN_GPIO_INPUT_0;
+	void __iomem *gpio_in1 = gpch->regs + TITAN_GPIO_INPUT_1;
+
+	return readl(gpio >> 5 ? gpio_in1 : gpio_in0) & (1 << (gpio & 0x1f));
+}
+
+static void ar7_gpio_set_value(struct gpio_chip *chip,
+				unsigned gpio, int value)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_out = gpch->regs + AR7_GPIO_OUTPUT;
+	unsigned tmp;
+
+	tmp = readl(gpio_out) & ~(1 << gpio);
+	if (value)
+		tmp |= 1 << gpio;
+	writel(tmp, gpio_out);
+}
+
+static void titan_gpio_set_value(struct gpio_chip *chip,
+				unsigned gpio, int value)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_out0 = gpch->regs + TITAN_GPIO_OUTPUT_0;
+	void __iomem *gpio_out1 = gpch->regs + TITAN_GPIO_OUTPUT_1;
+	unsigned tmp;
+
+	tmp = readl(gpio >> 5 ? gpio_out1 : gpio_out0) & ~(1 << (gpio & 0x1f));
+	if (value)
+		tmp |= 1 << (gpio & 0x1f);
+	writel(tmp, gpio >> 5 ? gpio_out1 : gpio_out0);
+}
+
+static int ar7_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_dir = gpch->regs + AR7_GPIO_DIR;
+
+	writel(readl(gpio_dir) | (1 << gpio), gpio_dir);
+
+	return 0;
+}
+
+static int titan_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_dir0 = gpch->regs + TITAN_GPIO_DIR_0;
+	void __iomem *gpio_dir1 = gpch->regs + TITAN_GPIO_DIR_1;
+
+	if (gpio >= TITAN_GPIO_MAX)
+		return -EINVAL;
+
+	writel(readl(gpio >> 5 ? gpio_dir1 : gpio_dir0) | (1 << (gpio & 0x1f)),
+			gpio >> 5 ? gpio_dir1 : gpio_dir0);
+	return 0;
+}
+
+static int ar7_gpio_direction_output(struct gpio_chip *chip,
+					unsigned gpio, int value)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_dir = gpch->regs + AR7_GPIO_DIR;
+
+	ar7_gpio_set_value(chip, gpio, value);
+	writel(readl(gpio_dir) & ~(1 << gpio), gpio_dir);
+
+	return 0;
+}
+
+static int titan_gpio_direction_output(struct gpio_chip *chip,
+					unsigned gpio, int value)
+{
+	struct ar7_gpio_chip *gpch = gpiochip_get_data(chip);
+	void __iomem *gpio_dir0 = gpch->regs + TITAN_GPIO_DIR_0;
+	void __iomem *gpio_dir1 = gpch->regs + TITAN_GPIO_DIR_1;
+
+	if (gpio >= TITAN_GPIO_MAX)
+		return -EINVAL;
+
+	titan_gpio_set_value(chip, gpio, value);
+	writel(readl(gpio >> 5 ? gpio_dir1 : gpio_dir0) & ~(1 <<
+		(gpio & 0x1f)), gpio >> 5 ? gpio_dir1 : gpio_dir0);
+
+	return 0;
+}
+
+static struct ar7_gpio_chip ar7_gpio_chip = {
+	.chip = {
+		.label			= "ar7-gpio",
+		.direction_input	= ar7_gpio_direction_input,
+		.direction_output	= ar7_gpio_direction_output,
+		.set			= ar7_gpio_set_value,
+		.get			= ar7_gpio_get_value,
+		.base			= 0,
+		.ngpio			= AR7_GPIO_MAX,
+	}
+};
+
+static struct ar7_gpio_chip titan_gpio_chip = {
+	.chip = {
+		.label			= "titan-gpio",
+		.direction_input	= titan_gpio_direction_input,
+		.direction_output	= titan_gpio_direction_output,
+		.set			= titan_gpio_set_value,
+		.get			= titan_gpio_get_value,
+		.base			= 0,
+		.ngpio			= TITAN_GPIO_MAX,
+	}
+};
+
+static inline int ar7_gpio_enable_ar7(unsigned gpio)
+{
+	void __iomem *gpio_en = ar7_gpio_chip.regs + AR7_GPIO_ENABLE;
+
+	writel(readl(gpio_en) | (1 << gpio), gpio_en);
+
+	return 0;
+}
+
+static inline int ar7_gpio_enable_titan(unsigned gpio)
+{
+	void __iomem *gpio_en0 = titan_gpio_chip.regs  + TITAN_GPIO_ENBL_0;
+	void __iomem *gpio_en1 = titan_gpio_chip.regs  + TITAN_GPIO_ENBL_1;
+
+	writel(readl(gpio >> 5 ? gpio_en1 : gpio_en0) | (1 << (gpio & 0x1f)),
+		gpio >> 5 ? gpio_en1 : gpio_en0);
+
+	return 0;
+}
+
+int ar7_gpio_enable(unsigned gpio)
+{
+	return ar7_is_titan() ? ar7_gpio_enable_titan(gpio) :
+				ar7_gpio_enable_ar7(gpio);
+}
+EXPORT_SYMBOL(ar7_gpio_enable);
+
+static inline int ar7_gpio_disable_ar7(unsigned gpio)
+{
+	void __iomem *gpio_en = ar7_gpio_chip.regs + AR7_GPIO_ENABLE;
+
+	writel(readl(gpio_en) & ~(1 << gpio), gpio_en);
+
+	return 0;
+}
+
+static inline int ar7_gpio_disable_titan(unsigned gpio)
+{
+	void __iomem *gpio_en0 = titan_gpio_chip.regs + TITAN_GPIO_ENBL_0;
+	void __iomem *gpio_en1 = titan_gpio_chip.regs + TITAN_GPIO_ENBL_1;
+
+	writel(readl(gpio >> 5 ? gpio_en1 : gpio_en0) & ~(1 << (gpio & 0x1f)),
+			gpio >> 5 ? gpio_en1 : gpio_en0);
+
+	return 0;
+}
+
+int ar7_gpio_disable(unsigned gpio)
+{
+	return ar7_is_titan() ? ar7_gpio_disable_titan(gpio) :
+				ar7_gpio_disable_ar7(gpio);
+}
+EXPORT_SYMBOL(ar7_gpio_disable);
+
+struct titan_gpio_cfg {
+	u32 reg;
+	u32 shift;
+	u32 func;
+};
+
+static const struct titan_gpio_cfg titan_gpio_table[] = {
+	/* reg, start bit, mux value */
+	{4, 24, 1},
+	{4, 26, 1},
+	{4, 28, 1},
+	{4, 30, 1},
+	{5, 6, 1},
+	{5, 8, 1},
+	{5, 10, 1},
+	{5, 12, 1},
+	{7, 14, 3},
+	{7, 16, 3},
+	{7, 18, 3},
+	{7, 20, 3},
+	{7, 22, 3},
+	{7, 26, 3},
+	{7, 28, 3},
+	{7, 30, 3},
+	{8, 0, 3},
+	{8, 2, 3},
+	{8, 4, 3},
+	{8, 10, 3},
+	{8, 14, 3},
+	{8, 16, 3},
+	{8, 18, 3},
+	{8, 20, 3},
+	{9, 8, 3},
+	{9, 10, 3},
+	{9, 12, 3},
+	{9, 14, 3},
+	{9, 18, 3},
+	{9, 20, 3},
+	{9, 24, 3},
+	{9, 26, 3},
+	{9, 28, 3},
+	{9, 30, 3},
+	{10, 0, 3},
+	{10, 2, 3},
+	{10, 8, 3},
+	{10, 10, 3},
+	{10, 12, 3},
+	{10, 14, 3},
+	{13, 12, 3},
+	{13, 14, 3},
+	{13, 16, 3},
+	{13, 18, 3},
+	{13, 24, 3},
+	{13, 26, 3},
+	{13, 28, 3},
+	{13, 30, 3},
+	{14, 2, 3},
+	{14, 6, 3},
+	{14, 8, 3},
+	{14, 12, 3}
+};
+
+static int titan_gpio_pinsel(unsigned gpio)
+{
+	struct titan_gpio_cfg gpio_cfg;
+	u32 mux_status, pin_sel_reg, tmp;
+	void __iomem *pin_sel = (void __iomem *)KSEG1ADDR(AR7_REGS_PINSEL);
+
+	if (gpio >= ARRAY_SIZE(titan_gpio_table))
+		return -EINVAL;
+
+	gpio_cfg = titan_gpio_table[gpio];
+	pin_sel_reg = gpio_cfg.reg - 1;
+
+	mux_status = (readl(pin_sel + pin_sel_reg) >> gpio_cfg.shift) & 0x3;
+
+	/* Check the mux status */
+	if (!((mux_status == 0) || (mux_status == gpio_cfg.func)))
+		return 0;
+
+	/* Set the pin sel value */
+	tmp = readl(pin_sel + pin_sel_reg);
+	tmp |= ((gpio_cfg.func & 0x3) << gpio_cfg.shift);
+	writel(tmp, pin_sel + pin_sel_reg);
+
+	return 0;
+}
+
+/* Perform minimal Titan GPIO configuration */
+static void titan_gpio_init(void)
+{
+	unsigned i;
+
+	for (i = 44; i < 48; i++) {
+		titan_gpio_pinsel(i);
+		ar7_gpio_enable_titan(i);
+		titan_gpio_direction_input(&titan_gpio_chip.chip, i);
+	}
+}
+
+int __init ar7_gpio_init(void)
+{
+	int ret;
+	struct ar7_gpio_chip *gpch;
+	unsigned size;
+
+	if (!ar7_is_titan()) {
+		gpch = &ar7_gpio_chip;
+		size = 0x10;
+	} else {
+		gpch = &titan_gpio_chip;
+		size = 0x1f;
+	}
+
+	gpch->regs = ioremap_nocache(AR7_REGS_GPIO, size);
+	if (!gpch->regs) {
+		printk(KERN_ERR "%s: failed to ioremap regs\n",
+					gpch->chip.label);
+		return -ENOMEM;
+	}
+
+	ret = gpiochip_add_data(&gpch->chip, gpch);
+	if (ret) {
+		printk(KERN_ERR "%s: failed to add gpiochip\n",
+					gpch->chip.label);
+		return ret;
+	}
+	printk(KERN_INFO "%s: registered %d GPIOs\n",
+				gpch->chip.label, gpch->chip.ngpio);
+
+	if (ar7_is_titan())
+		titan_gpio_init();
+
+	return ret;
+}