[PATCH v4 1/2] gpio: loongson: add dts and acpi support

[Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>]

Latest Loongson platforms such as the Loongson-2 SoC series describe
GPIO device resources with DTS or ACPI. Add such support to the
existing platform device driver.

Signed-off-by: Jianmin Lv <lvjianmin@xxxxxxxxxxx>
Signed-off-by: Hongchen Zhang <zhanghongchen@xxxxxxxxxxx>
Signed-off-by: Liu Peibao <liupeibao@xxxxxxxxxxx>
Signed-off-by: Juxin Gao <gaojuxin@xxxxxxxxxxx>
Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
---
Change in v4:
		1. Fixup name spelling about Signed-off-by. 
		2. Drop "series" here and everywhere else.
		3. Fixup the copyright in driver.
		4. Drop the "else" in loongson_gpio_request.
		5. Use trinocular operation replace the related logic.
		6. Remove lable judgement in context about "lgpio->chip.to_irq = 
		   loongson_gpio_to_irq"
		7. Use dev_err replace pr_err in probe.
		8. Make legacy platform_data should be left out of this patch.
		9. Remove the mips config in gpio Kconfig.
Change in v3:
		1. Move the gpio platform data struct from arch/ into include/linux/
		   platform_data/.
		2. Replace platform_gpio_data with loongson_gpio_platform_data in .c.
		3. Add maintainer in MAINTAINERS file for include/linux/platform_data/
		   gpio-loongson.h and gpio-loongson.c
Change in v2:
		1. Fixup of_loongson_gpio_get_props and remove the parse logic about
	           "loongson,conf_offset", "loongson,out_offset", "loongson,in_offset",
		   "loongson,gpio_base", "loongson,support_irq" then kernel driver will
		   initial them that depend compatible except "loongson,gpio_base".

 MAINTAINERS                  |   8 +
 drivers/gpio/Kconfig         |   6 +-
 drivers/gpio/gpio-loongson.c | 403 ++++++++++++++++++++++++++++-------
 3 files changed, 338 insertions(+), 79 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 5114db9c8f32..838b920efcef 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12051,6 +12051,14 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/hwinfo/loongson,ls2k-chipid.yaml
 F:	drivers/soc/loongson/loongson2_guts.c
 
+LOONGSON GPIO DRIVER
+M:	Huacai Chen <chenhuacai@xxxxxxxxxx>
+M:	Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
+L:	linux-gpio@xxxxxxxxxxxxxxx
+S:	Maintained
+F:	drivers/gpio/gpio-loongson.c
+F:	include/linux/platform_data/gpio-loongson.h
+
 LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
 M:	Sathya Prakash <sathya.prakash@xxxxxxxxxxxx>
 M:	Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index a01af1180616..b4423c058b1d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -376,10 +376,10 @@ config GPIO_LOGICVC
 	  programmable logic block.
 
 config GPIO_LOONGSON
-	bool "Loongson-2/3 GPIO support"
-	depends on CPU_LOONGSON2EF || CPU_LOONGSON64
+	bool "Loongson series GPIO support"
+	depends on LOONGARCH || COMPILE_TEST
 	help
-	  Driver for GPIO functionality on Loongson-2F/3A/3B processors.
+	  Driver for GPIO functionality on Loongson seires processors.
 
 config GPIO_LPC18XX
 	tristate "NXP LPC18XX/43XX GPIO support"
diff --git a/drivers/gpio/gpio-loongson.c b/drivers/gpio/gpio-loongson.c
index a42145873cc9..b9b191a541c0 100644
--- a/drivers/gpio/gpio-loongson.c
+++ b/drivers/gpio/gpio-loongson.c
@@ -1,13 +1,11 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-License-Identifier: GPL-2.0+
 /*
- *  Loongson-2F/3A/3B GPIO Support
+ * Loongson GPIO Support
  *
- *  Copyright (c) 2008 Richard Liu,  STMicroelectronics	 <richard.liu@xxxxxx>
- *  Copyright (c) 2008-2010 Arnaud Patard <apatard@xxxxxxxxxxxx>
- *  Copyright (c) 2013 Hongbing Hu <huhb@xxxxxxxxxx>
- *  Copyright (c) 2014 Huacai Chen <chenhc@xxxxxxxxxx>
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
  */
 
+#include <linux/acpi.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
@@ -17,119 +15,372 @@
 #include <linux/platform_device.h>
 #include <linux/bitops.h>
 #include <asm/types.h>
-#include <loongson.h>
+#include <asm/loongson.h>
 
-#define STLS2F_N_GPIO		4
-#define STLS3A_N_GPIO		16
+#define LOONGSON_GPIO_IN(x)		(x->base + x->in_offset)
+#define LOONGSON_GPIO_OUT(x)		(x->base + x->out_offset)
+#define LOONGSON_GPIO_OEN(x)		(x->base + x->conf_offset)
 
-#ifdef CONFIG_CPU_LOONGSON64
-#define LOONGSON_N_GPIO	STLS3A_N_GPIO
-#else
-#define LOONGSON_N_GPIO	STLS2F_N_GPIO
-#endif
+#define LOONGSON_GPIO_IN_BYTE(x, gpio)	(x->base +\
+					x->in_offset + gpio)
+#define LOONGSON_GPIO_OUT_BYTE(x, gpio)	(x->base +\
+					x->out_offset + gpio)
+#define LOONGSON_GPIO_OEN_BYTE(x, gpio)	(x->base +\
+					x->conf_offset + gpio)
 
-/*
- * 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
+struct loongson_gpio_chip {
+	struct gpio_chip	chip;
+	spinlock_t		lock;
+	void __iomem		*base;
+	int			conf_offset;
+	int			out_offset;
+	int			in_offset;
+	u16			*gsi_idx_map;
+	u16			mapsize;
+};
 
-static DEFINE_SPINLOCK(gpio_lock);
+static int loongson_gpio_request(
+			struct gpio_chip *chip, unsigned int pin)
+{
+	if (pin >= chip->ngpio)
+		return -EINVAL;
+
+	return 0;
+}
 
-static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+static inline void __set_direction(struct loongson_gpio_chip *lgpio,
+			unsigned int pin, int input)
 {
-	u32 val;
+	u64 qval;
+	u8  bval;
+
+	if (!strcmp(lgpio->chip.label, "loongson,ls2k-gpio")) {
+		qval = readq(LOONGSON_GPIO_OEN(lgpio));
+		if (input)
+			qval |= 1ULL << pin;
+		else
+			qval &= ~(1ULL << pin);
+		writeq(qval, LOONGSON_GPIO_OEN(lgpio));
+		return;
+	}
 
-	spin_lock(&gpio_lock);
-	val = LOONGSON_GPIODATA;
-	spin_unlock(&gpio_lock);
+	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
+			!strncmp(lgpio->chip.label, "LOON0002", 8)) {
+		bval = input ? 1 : 0;
+		writeb(bval, LOONGSON_GPIO_OEN_BYTE(lgpio, pin));
+		return;
+	}
 
-	return !!(val & BIT(gpio + LOONGSON_GPIO_IN_OFFSET));
+	if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
+		if (input)
+			LOONGSON_GPIOIE |= BIT(pin);
+		else
+			LOONGSON_GPIOIE &= ~BIT(pin);
+		return;
+	}
 }
 
-static void loongson_gpio_set_value(struct gpio_chip *chip,
-		unsigned gpio, int value)
+static void __set_level(struct loongson_gpio_chip *lgpio, unsigned int pin,
+			int high)
 {
-	u32 val;
+	u64 qval;
+	u8 bval;
 
-	spin_lock(&gpio_lock);
-	val = LOONGSON_GPIODATA;
-	if (value)
-		val |= BIT(gpio);
-	else
-		val &= ~BIT(gpio);
-	LOONGSON_GPIODATA = val;
-	spin_unlock(&gpio_lock);
+	if (!strcmp(lgpio->chip.label, "loongson,ls2k-gpio")) {
+		qval = readq(LOONGSON_GPIO_OUT(lgpio));
+		if (high)
+			qval |= 1ULL << pin;
+		else
+			qval &= ~(1ULL << pin);
+		writeq(qval, LOONGSON_GPIO_OUT(lgpio));
+		return;
+	}
+
+	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
+			!strncmp(lgpio->chip.label, "LOON0002", 8)) {
+		bval = high ? 1 : 0;
+		writeb(bval, LOONGSON_GPIO_OUT_BYTE(lgpio, pin));
+		return;
+	}
+
+	if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
+		if (LOONGSON_GPIODATA)
+			LOONGSON_GPIODATA |= BIT(pin);
+		else
+			LOONGSON_GPIODATA &= ~BIT(pin);
+		return;
+	}
 }
 
-static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+static int loongson_gpio_direction_input(
+				struct gpio_chip *chip, unsigned int pin)
 {
-	u32 temp;
+	unsigned long flags;
+	struct loongson_gpio_chip *lgpio =
+		container_of(chip, struct loongson_gpio_chip, chip);
 
-	spin_lock(&gpio_lock);
-	temp = LOONGSON_GPIOIE;
-	temp |= BIT(gpio);
-	LOONGSON_GPIOIE = temp;
-	spin_unlock(&gpio_lock);
+	spin_lock_irqsave(&lgpio->lock, flags);
+	__set_direction(lgpio, pin, 1);
+	spin_unlock_irqrestore(&lgpio->lock, flags);
 
 	return 0;
 }
 
-static int loongson_gpio_direction_output(struct gpio_chip *chip,
-		unsigned gpio, int level)
+static int loongson_gpio_direction_output(
+				struct gpio_chip *chip, unsigned int pin,
+				int value)
 {
-	u32 temp;
+	struct loongson_gpio_chip *lgpio =
+		container_of(chip, struct loongson_gpio_chip, chip);
+	unsigned long flags;
 
-	loongson_gpio_set_value(chip, gpio, level);
-	spin_lock(&gpio_lock);
-	temp = LOONGSON_GPIOIE;
-	temp &= ~BIT(gpio);
-	LOONGSON_GPIOIE = temp;
-	spin_unlock(&gpio_lock);
+	spin_lock_irqsave(&lgpio->lock, flags);
+	__set_level(lgpio, pin, value);
+	__set_direction(lgpio, pin, 0);
+	spin_unlock_irqrestore(&lgpio->lock, flags);
 
 	return 0;
 }
 
+static int loongson_gpio_get(struct gpio_chip *chip, unsigned int pin)
+{
+	u64 qval;
+	u8  bval;
+	int val;
+	struct loongson_gpio_chip *lgpio =
+		container_of(chip, struct loongson_gpio_chip, chip);
+
+	if (!strcmp(lgpio->chip.label, "loongson,ls2k-gpio")) {
+		qval = readq(LOONGSON_GPIO_IN(lgpio));
+		return ((qval & (1ULL << pin)) != 0);
+	}
+
+	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
+			!strncmp(lgpio->chip.label, "LOON0002", 8)) {
+		bval = readb(LOONGSON_GPIO_IN_BYTE(lgpio, pin));
+		return (bval & 1);
+	}
+
+	if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
+		val = LOONGSON_GPIODATA;
+		return !!(val & BIT(pin + lgpio->in_offset));
+	}
+
+	return -ENXIO;
+}
+
+static void loongson_gpio_set(struct gpio_chip *chip, unsigned int pin,
+			int value)
+{
+	unsigned long flags;
+	struct loongson_gpio_chip *lgpio =
+		container_of(chip, struct loongson_gpio_chip, chip);
+
+	spin_lock_irqsave(&lgpio->lock, flags);
+	__set_level(lgpio, pin, value);
+	spin_unlock_irqrestore(&lgpio->lock, flags);
+}
+
+static int loongson_gpio_to_irq(
+			struct gpio_chip *chip, unsigned int offset)
+{
+	struct platform_device *pdev =
+		container_of(chip->parent, struct platform_device, dev);
+	struct loongson_gpio_chip *lgpio =
+		container_of(chip, struct loongson_gpio_chip, chip);
+
+	if (offset >= chip->ngpio)
+		return -EINVAL;
+
+	if ((lgpio->gsi_idx_map != NULL) && (offset < lgpio->mapsize))
+		offset = lgpio->gsi_idx_map[offset];
+
+	return platform_get_irq(pdev, offset);
+}
+
+static int loongson_gpio_init(
+			struct device *dev, struct loongson_gpio_chip *lgpio,
+			struct device_node *np, void __iomem *base)
+{
+	lgpio->chip.request = loongson_gpio_request;
+	lgpio->chip.direction_input = loongson_gpio_direction_input;
+	lgpio->chip.get = loongson_gpio_get;
+	lgpio->chip.direction_output = loongson_gpio_direction_output;
+	lgpio->chip.set = loongson_gpio_set;
+	lgpio->chip.can_sleep = 0;
+	lgpio->chip.of_node = np;
+	lgpio->chip.parent = dev;
+	spin_lock_init(&lgpio->lock);
+	lgpio->base = (void __iomem *)base;
+	lgpio->chip.to_irq = loongson_gpio_to_irq;
+
+	gpiochip_add(&lgpio->chip);
+
+	return 0;
+}
+
+static void of_loongson_gpio_get_props(struct device_node *np,
+				  struct loongson_gpio_chip *lgpio)
+{
+	const char *name;
+
+	of_property_read_u32(np, "ngpios", (u32 *)&lgpio->chip.ngpio);
+
+	of_property_read_string(np, "compatible", &name);
+	lgpio->chip.label = kstrdup(name, GFP_KERNEL);
+
+	if (!strcmp(name, "loongson,ls2k-gpio")) {
+		lgpio->conf_offset = 0x0;
+		lgpio->out_offset = 0x10;
+		lgpio->in_offset = 0x20;
+		return;
+	}
+
+	if (!strcmp(name, "loongson,ls7a-gpio")) {
+		lgpio->conf_offset = 0x800;
+		lgpio->out_offset = 0x900;
+		lgpio->in_offset = 0xa00;
+		return;
+	}
+}
+
+static void acpi_loongson_gpio_get_props(struct platform_device *pdev,
+				  struct loongson_gpio_chip *lgpio)
+{
+
+	struct device *dev = &pdev->dev;
+	int rval;
+
+	device_property_read_u32(dev, "ngpios", (u32 *)&lgpio->chip.ngpio);
+	device_property_read_u32(dev, "gpio_base", (u32 *)&lgpio->chip.base);
+	device_property_read_u32(dev, "conf_offset",
+					(u32 *)&lgpio->conf_offset);
+	device_property_read_u32(dev, "out_offset",
+					(u32 *)&lgpio->out_offset);
+	device_property_read_u32(dev, "in_offset", (u32 *)&lgpio->in_offset);
+
+	rval = device_property_read_u16_array(dev, "gsi_idx_map", NULL, 0);
+	if (rval > 0) {
+		lgpio->gsi_idx_map =
+			kmalloc_array(rval, sizeof(*lgpio->gsi_idx_map),
+					GFP_KERNEL);
+		if (unlikely(!lgpio->gsi_idx_map)) {
+			dev_err(dev, "Alloc gsi_idx_map fail!\n");
+		} else {
+			lgpio->mapsize = rval;
+			device_property_read_u16_array(dev, "gsi_idx_map",
+					lgpio->gsi_idx_map, lgpio->mapsize);
+		}
+	}
+
+	lgpio->chip.label = kstrdup(pdev->name, GFP_KERNEL);
+}
+
+static void platform_loongson_gpio_get_props(struct platform_device *pdev,
+				  struct loongson_gpio_chip *lgpio)
+{
+}
+
 static int loongson_gpio_probe(struct platform_device *pdev)
 {
-	struct gpio_chip *gc;
+	struct resource *iores;
+	void __iomem *base;
+	struct loongson_gpio_chip *lgpio;
+	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
+	int ret = 0;
 
-	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
-	if (!gc)
+	lgpio = kzalloc(sizeof(struct loongson_gpio_chip), GFP_KERNEL);
+	if (!lgpio)
 		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;
+	if (np)
+		of_loongson_gpio_get_props(np, lgpio);
+	else if (ACPI_COMPANION(&pdev->dev))
+		acpi_loongson_gpio_get_props(pdev, lgpio);
+	else
+		platform_loongson_gpio_get_props(pdev, lgpio);
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!iores) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (!request_mem_region(iores->start, resource_size(iores),
+				pdev->name)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	base = ioremap(iores->start, resource_size(iores));
+	if (!base) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	platform_set_drvdata(pdev, lgpio);
+
+	loongson_gpio_init(dev, lgpio, np, base);
+
+	return 0;
+out:
+	dev_err(dev, "missing mandatory property\n");
+
+	return ret;
+}
+
+static int loongson_gpio_remove(struct platform_device *pdev)
+{
+	struct loongson_gpio_chip *lgpio = platform_get_drvdata(pdev);
+	struct resource		*mem;
 
-	return gpiochip_add_data(gc, NULL);
+	platform_set_drvdata(pdev, NULL);
+
+	gpiochip_remove(&lgpio->chip);
+	iounmap(lgpio->base);
+	kfree(lgpio->gsi_idx_map);
+	kfree(lgpio);
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(mem->start, resource_size(mem));
+
+	return 0;
 }
 
+static const struct of_device_id loongson_gpio_dt_ids[] = {
+	{ .compatible = "loongson,ls2k-gpio"},
+	{ .compatible = "loongson,ls7a-gpio"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, loongson_gpio_dt_ids);
+
+static const struct acpi_device_id loongson_gpio_acpi_match[] = {
+	{"LOON0002"},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, loongson_gpio_acpi_match);
+
 static struct platform_driver loongson_gpio_driver = {
 	.driver = {
 		.name = "loongson-gpio",
+		.owner = THIS_MODULE,
+		.of_match_table = loongson_gpio_dt_ids,
+		.acpi_match_table = ACPI_PTR(loongson_gpio_acpi_match),
 	},
 	.probe = loongson_gpio_probe,
+	.remove = loongson_gpio_remove,
 };
 
 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);
+	return platform_driver_register(&loongson_gpio_driver);
 }
 postcore_initcall(loongson_gpio_setup);
+
+static void __exit loongson_gpio_exit(void)
+{
+	platform_driver_unregister(&loongson_gpio_driver);
+}
+
+MODULE_DESCRIPTION("Loongson gpio driver");
+MODULE_LICENSE("GPL");
-- 
2.31.1