From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Thu, 11 Apr 2024 10:27:49 +0200
Subject: Adding upstream version 6.6.15.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 drivers/gpio/gpio-loongson.c | 135 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 drivers/gpio/gpio-loongson.c

(limited to 'drivers/gpio/gpio-loongson.c')

diff --git a/drivers/gpio/gpio-loongson.c b/drivers/gpio/gpio-loongson.c
new file mode 100644
index 0000000000..a42145873c
--- /dev/null
+++ b/drivers/gpio/gpio-loongson.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  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>
+ */
+
+#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_LOONGSON64
+#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);
-- 
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