v4.19.13 snapshot.
diff --git a/drivers/gpio/gpio-loongson.c b/drivers/gpio/gpio-loongson.c
new file mode 100644
index 0000000..16cfbe9
--- /dev/null
+++ b/drivers/gpio/gpio-loongson.c
@@ -0,0 +1,139 @@
+/*
+ * Loongson-2F/3A/3B GPIO Support
+ *
+ * Copyright (c) 2008 Richard Liu, STMicroelectronics <richard.liu@st.com>
+ * Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>
+ * Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>
+ * Copyright (c) 2014 Huacai Chen <chenhc@lemote.com>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+#include <asm/types.h>
+#include <loongson.h>
+
+#define STLS2F_N_GPIO 4
+#define STLS3A_N_GPIO 16
+
+#ifdef CONFIG_CPU_LOONGSON3
+#define LOONGSON_N_GPIO STLS3A_N_GPIO
+#else
+#define LOONGSON_N_GPIO STLS2F_N_GPIO
+#endif
+
+/*
+ * Offset into the register where we read lines, we write them from offset 0.
+ * This offset is the only thing that stand between us and using
+ * GPIO_GENERIC.
+ */
+#define LOONGSON_GPIO_IN_OFFSET 16
+
+static DEFINE_SPINLOCK(gpio_lock);
+
+static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+ u32 val;
+
+ spin_lock(&gpio_lock);
+ val = LOONGSON_GPIODATA;
+ spin_unlock(&gpio_lock);
+
+ return !!(val & BIT(gpio + LOONGSON_GPIO_IN_OFFSET));
+}
+
+static void loongson_gpio_set_value(struct gpio_chip *chip,
+ unsigned gpio, int value)
+{
+ u32 val;
+
+ spin_lock(&gpio_lock);
+ val = LOONGSON_GPIODATA;
+ if (value)
+ val |= BIT(gpio);
+ else
+ val &= ~BIT(gpio);
+ LOONGSON_GPIODATA = val;
+ spin_unlock(&gpio_lock);
+}
+
+static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+ u32 temp;
+
+ spin_lock(&gpio_lock);
+ temp = LOONGSON_GPIOIE;
+ temp |= BIT(gpio);
+ LOONGSON_GPIOIE = temp;
+ spin_unlock(&gpio_lock);
+
+ return 0;
+}
+
+static int loongson_gpio_direction_output(struct gpio_chip *chip,
+ unsigned gpio, int level)
+{
+ u32 temp;
+
+ loongson_gpio_set_value(chip, gpio, level);
+ spin_lock(&gpio_lock);
+ temp = LOONGSON_GPIOIE;
+ temp &= ~BIT(gpio);
+ LOONGSON_GPIOIE = temp;
+ spin_unlock(&gpio_lock);
+
+ return 0;
+}
+
+static int loongson_gpio_probe(struct platform_device *pdev)
+{
+ struct gpio_chip *gc;
+ struct device *dev = &pdev->dev;
+
+ gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+ if (!gc)
+ return -ENOMEM;
+
+ gc->label = "loongson-gpio-chip";
+ gc->base = 0;
+ gc->ngpio = LOONGSON_N_GPIO;
+ gc->get = loongson_gpio_get_value;
+ gc->set = loongson_gpio_set_value;
+ gc->direction_input = loongson_gpio_direction_input;
+ gc->direction_output = loongson_gpio_direction_output;
+
+ return gpiochip_add_data(gc, NULL);
+}
+
+static struct platform_driver loongson_gpio_driver = {
+ .driver = {
+ .name = "loongson-gpio",
+ },
+ .probe = loongson_gpio_probe,
+};
+
+static int __init loongson_gpio_setup(void)
+{
+ struct platform_device *pdev;
+ int ret;
+
+ ret = platform_driver_register(&loongson_gpio_driver);
+ if (ret) {
+ pr_err("error registering loongson GPIO driver\n");
+ return ret;
+ }
+
+ pdev = platform_device_register_simple("loongson-gpio", -1, NULL, 0);
+ return PTR_ERR_OR_ZERO(pdev);
+}
+postcore_initcall(loongson_gpio_setup);