[PATCH v7 5/9] gpio/rockchip: add driver for rockchip gpio

[Jianqun Xu <jay.xu@xxxxxxxxxxxxxx>]

This patch add support for rockchip gpio controller, which is supported
in pinctrl driver in the past.

With this patch, the pinctrl-rockchip driver will drop gpio related
codes and populate platform driver to gpio-rockchip.

Signed-off-by: Jianqun Xu <jay.xu@xxxxxxxxxxxxxx>
---
v7:
 - include gpio/driver.h instead of gpio.h, suggested by Walleij
 - use gpio align id instead of gpio bank name
v6:
 - reorder patches suggested by heiko

 drivers/gpio/Kconfig         |   8 +
 drivers/gpio/Makefile        |   1 +
 drivers/gpio/gpio-rockchip.c | 626 +++++++++++++++++++++++++++++++++++
 3 files changed, 635 insertions(+)
 create mode 100644 drivers/gpio/gpio-rockchip.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 1dd0ec6727fd..764ef6b14678 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -520,6 +520,14 @@ config GPIO_REG
 	  A 32-bit single register GPIO fixed in/out implementation.  This
 	  can be used to represent any register as a set of GPIO signals.
 
+config GPIO_ROCKCHIP
+	tristate "Rockchip GPIO support"
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	select GPIOLIB_IRQCHIP
+	default ARCH_ROCKCHIP
+	help
+	  Say yes here to support GPIO on Rockchip SoCs.
+
 config GPIO_SAMA5D2_PIOBU
 	tristate "SAMA5D2 PIOBU GPIO support"
 	depends on MFD_SYSCON
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index d7c81e1611a4..81e95a0db25b 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -127,6 +127,7 @@ obj-$(CONFIG_GPIO_RDA)			+= gpio-rda.o
 obj-$(CONFIG_GPIO_RDC321X)		+= gpio-rdc321x.o
 obj-$(CONFIG_GPIO_REALTEK_OTTO)		+= gpio-realtek-otto.o
 obj-$(CONFIG_GPIO_REG)			+= gpio-reg.o
+obj-$(CONFIG_GPIO_ROCKCHIP)	+= gpio-rockchip.o
 obj-$(CONFIG_ARCH_SA1100)		+= gpio-sa1100.o
 obj-$(CONFIG_GPIO_SAMA5D2_PIOBU)	+= gpio-sama5d2-piobu.o
 obj-$(CONFIG_GPIO_SCH311X)		+= gpio-sch311x.o
diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
new file mode 100644
index 000000000000..b455fcf7efda
--- /dev/null
+++ b/drivers/gpio/gpio-rockchip.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2013 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@xxxxxxxxx>
+ *
+ * Copyright (c) 2021 Rockchip Electronics Co. Ltd.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/regmap.h>
+
+#include "../pinctrl/core.h"
+#include "../pinctrl/pinctrl-rockchip.h"
+
+/* GPIO control registers */
+#define GPIO_SWPORT_DR		0x00
+#define GPIO_SWPORT_DDR		0x04
+#define GPIO_INTEN		0x30
+#define GPIO_INTMASK		0x34
+#define GPIO_INTTYPE_LEVEL	0x38
+#define GPIO_INT_POLARITY	0x3c
+#define GPIO_INT_STATUS		0x40
+#define GPIO_INT_RAWSTATUS	0x44
+#define GPIO_DEBOUNCE		0x48
+#define GPIO_PORTS_EOI		0x4c
+#define GPIO_EXT_PORT		0x50
+#define GPIO_LS_SYNC		0x60
+
+static int rockchip_gpio_get_direction(struct gpio_chip *chip,
+				       unsigned int offset)
+{
+	struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
+	u32 data;
+
+	data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
+	if (data & BIT(offset))
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int rockchip_gpio_set_direction(struct gpio_chip *chip,
+				       unsigned int offset, bool input)
+{
+	struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
+	unsigned long flags;
+	u32 data;
+
+	raw_spin_lock_irqsave(&bank->slock, flags);
+
+	data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
+	/* set bit to 1 for output, 0 for input */
+	if (!input)
+		data |= BIT(offset);
+	else
+		data &= ~BIT(offset);
+	writel_relaxed(data, bank->reg_base + GPIO_SWPORT_DDR);
+
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
+
+	return 0;
+}
+
+static void rockchip_gpio_set(struct gpio_chip *gc, unsigned int offset,
+			      int value)
+{
+	struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
+	void __iomem *reg = bank->reg_base + GPIO_SWPORT_DR;
+	unsigned long flags;
+	u32 data;
+
+	raw_spin_lock_irqsave(&bank->slock, flags);
+
+	data = readl(reg);
+	data &= ~BIT(offset);
+	if (value)
+		data |= BIT(offset);
+	writel(data, reg);
+
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
+}
+
+static int rockchip_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
+	u32 data;
+
+	data = readl(bank->reg_base + GPIO_EXT_PORT);
+	data >>= offset;
+	data &= 1;
+	return data;
+}
+
+static void rockchip_gpio_set_debounce(struct gpio_chip *gc,
+				       unsigned int offset, bool enable)
+{
+	struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
+	void __iomem *reg = bank->reg_base + GPIO_DEBOUNCE;
+	unsigned long flags;
+	u32 data;
+
+	raw_spin_lock_irqsave(&bank->slock, flags);
+
+	data = readl(reg);
+	if (enable)
+		data |= BIT(offset);
+	else
+		data &= ~BIT(offset);
+	writel(data, reg);
+
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
+}
+
+static int rockchip_gpio_direction_input(struct gpio_chip *gc,
+					 unsigned int offset)
+{
+	return rockchip_gpio_set_direction(gc, offset, true);
+}
+
+static int rockchip_gpio_direction_output(struct gpio_chip *gc,
+					  unsigned int offset, int value)
+{
+	rockchip_gpio_set(gc, offset, value);
+
+	return rockchip_gpio_set_direction(gc, offset, false);
+}
+
+/*
+ * gpiolib set_config callback function. The setting of the pin
+ * mux function as 'gpio output' will be handled by the pinctrl subsystem
+ * interface.
+ */
+static int rockchip_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+				  unsigned long config)
+{
+	enum pin_config_param param = pinconf_to_config_param(config);
+
+	switch (param) {
+	case PIN_CONFIG_INPUT_DEBOUNCE:
+		rockchip_gpio_set_debounce(gc, offset, true);
+		/*
+		 * Rockchip's gpio could only support up to one period
+		 * of the debounce clock(pclk), which is far away from
+		 * satisftying the requirement, as pclk is usually near
+		 * 100MHz shared by all peripherals. So the fact is it
+		 * has crippled debounce capability could only be useful
+		 * to prevent any spurious glitches from waking up the system
+		 * if the gpio is conguired as wakeup interrupt source. Let's
+		 * still return -ENOTSUPP as before, to make sure the caller
+		 * of gpiod_set_debounce won't change its behaviour.
+		 */
+		return -ENOTSUPP;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+/*
+ * gpiolib gpio_to_irq callback function. Creates a mapping between a GPIO pin
+ * and a virtual IRQ, if not already present.
+ */
+static int rockchip_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
+{
+	struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
+	unsigned int virq;
+
+	if (!bank->domain)
+		return -ENXIO;
+
+	virq = irq_create_mapping(bank->domain, offset);
+
+	return (virq) ? : -ENXIO;
+}
+
+static const struct gpio_chip rockchip_gpiolib_chip = {
+	.request = gpiochip_generic_request,
+	.free = gpiochip_generic_free,
+	.set = rockchip_gpio_set,
+	.get = rockchip_gpio_get,
+	.get_direction	= rockchip_gpio_get_direction,
+	.direction_input = rockchip_gpio_direction_input,
+	.direction_output = rockchip_gpio_direction_output,
+	.set_config = rockchip_gpio_set_config,
+	.to_irq = rockchip_gpio_to_irq,
+	.owner = THIS_MODULE,
+};
+
+static void rockchip_irq_demux(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct rockchip_pin_bank *bank = irq_desc_get_handler_data(desc);
+	u32 pend;
+
+	dev_dbg(bank->dev, "got irq for bank %s\n", bank->name);
+
+	chained_irq_enter(chip, desc);
+
+	pend = readl_relaxed(bank->reg_base + GPIO_INT_STATUS);
+
+	while (pend) {
+		unsigned int irq, virq;
+
+		irq = __ffs(pend);
+		pend &= ~BIT(irq);
+		virq = irq_find_mapping(bank->domain, irq);
+
+		if (!virq) {
+			dev_err(bank->dev, "unmapped irq %d\n", irq);
+			continue;
+		}
+
+		dev_dbg(bank->dev, "handling irq %d\n", irq);
+
+		/*
+		 * Triggering IRQ on both rising and falling edge
+		 * needs manual intervention.
+		 */
+		if (bank->toggle_edge_mode & BIT(irq)) {
+			u32 data, data_old, polarity;
+			unsigned long flags;
+
+			data = readl_relaxed(bank->reg_base + GPIO_EXT_PORT);
+			do {
+				raw_spin_lock_irqsave(&bank->slock, flags);
+
+				polarity = readl_relaxed(bank->reg_base +
+							 GPIO_INT_POLARITY);
+				if (data & BIT(irq))
+					polarity &= ~BIT(irq);
+				else
+					polarity |= BIT(irq);
+				writel(polarity,
+				       bank->reg_base + GPIO_INT_POLARITY);
+
+				raw_spin_unlock_irqrestore(&bank->slock, flags);
+
+				data_old = data;
+				data = readl_relaxed(bank->reg_base +
+						     GPIO_EXT_PORT);
+			} while ((data & BIT(irq)) != (data_old & BIT(irq)));
+		}
+
+		generic_handle_irq(virq);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int rockchip_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct rockchip_pin_bank *bank = gc->private;
+	u32 mask = BIT(d->hwirq);
+	u32 polarity;
+	u32 level;
+	u32 data;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&bank->slock, flags);
+
+	data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
+	data &= ~mask;
+	writel_relaxed(data, bank->reg_base + GPIO_SWPORT_DDR);
+
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
+
+	if (type & IRQ_TYPE_EDGE_BOTH)
+		irq_set_handler_locked(d, handle_edge_irq);
+	else
+		irq_set_handler_locked(d, handle_level_irq);
+
+	raw_spin_lock_irqsave(&bank->slock, flags);
+	irq_gc_lock(gc);
+
+	level = readl_relaxed(gc->reg_base + GPIO_INTTYPE_LEVEL);
+	polarity = readl_relaxed(gc->reg_base + GPIO_INT_POLARITY);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_BOTH:
+		bank->toggle_edge_mode |= mask;
+		level |= mask;
+
+		/*
+		 * Determine gpio state. If 1 next interrupt should be falling
+		 * otherwise rising.
+		 */
+		data = readl(bank->reg_base + GPIO_EXT_PORT);
+		if (data & mask)
+			polarity &= ~mask;
+		else
+			polarity |= mask;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		bank->toggle_edge_mode &= ~mask;
+		level |= mask;
+		polarity |= mask;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		bank->toggle_edge_mode &= ~mask;
+		level |= mask;
+		polarity &= ~mask;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		bank->toggle_edge_mode &= ~mask;
+		level &= ~mask;
+		polarity |= mask;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		bank->toggle_edge_mode &= ~mask;
+		level &= ~mask;
+		polarity &= ~mask;
+		break;
+	default:
+		irq_gc_unlock(gc);
+		raw_spin_unlock_irqrestore(&bank->slock, flags);
+		clk_disable(bank->clk);
+		return -EINVAL;
+	}
+
+	writel_relaxed(level, gc->reg_base + GPIO_INTTYPE_LEVEL);
+	writel_relaxed(polarity, gc->reg_base + GPIO_INT_POLARITY);
+
+	irq_gc_unlock(gc);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
+
+	return 0;
+}
+
+static void rockchip_irq_suspend(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct rockchip_pin_bank *bank = gc->private;
+
+	bank->saved_masks = irq_reg_readl(gc, GPIO_INTMASK);
+	irq_reg_writel(gc, ~gc->wake_active, GPIO_INTMASK);
+}
+
+static void rockchip_irq_resume(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct rockchip_pin_bank *bank = gc->private;
+
+	irq_reg_writel(gc, bank->saved_masks, GPIO_INTMASK);
+}
+
+static void rockchip_irq_enable(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct rockchip_pin_bank *bank = gc->private;
+
+	irq_gc_mask_clr_bit(d);
+}
+
+static void rockchip_irq_disable(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct rockchip_pin_bank *bank = gc->private;
+
+	irq_gc_mask_set_bit(d);
+	clk_disable(bank->clk);
+}
+
+static int rockchip_interrupts_register(struct rockchip_pin_bank *bank)
+{
+	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+	struct irq_chip_generic *gc;
+	int ret;
+
+	bank->domain = irq_domain_add_linear(bank->of_node, 32,
+					&irq_generic_chip_ops, NULL);
+	if (!bank->domain) {
+		dev_warn(bank->dev, "could not init irq domain for bank %s\n",
+			 bank->name);
+		return -EINVAL;
+	}
+
+	ret = irq_alloc_domain_generic_chips(bank->domain, 32, 1,
+					     "rockchip_gpio_irq",
+					     handle_level_irq,
+					     clr, 0, 0);
+	if (ret) {
+		dev_err(bank->dev, "could not alloc generic chips for bank %s\n",
+			bank->name);
+		irq_domain_remove(bank->domain);
+		return -EINVAL;
+	}
+
+	gc = irq_get_domain_generic_chip(bank->domain, 0);
+	gc->reg_base = bank->reg_base;
+	gc->private = bank;
+	gc->chip_types[0].regs.mask = GPIO_INTMASK;
+	gc->chip_types[0].regs.ack = GPIO_PORTS_EOI;
+	gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
+	gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
+	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
+	gc->chip_types[0].chip.irq_enable = rockchip_irq_enable;
+	gc->chip_types[0].chip.irq_disable = rockchip_irq_disable;
+	gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
+	gc->chip_types[0].chip.irq_suspend = rockchip_irq_suspend;
+	gc->chip_types[0].chip.irq_resume = rockchip_irq_resume;
+	gc->chip_types[0].chip.irq_set_type = rockchip_irq_set_type;
+	gc->wake_enabled = IRQ_MSK(bank->nr_pins);
+
+	/*
+	 * Linux assumes that all interrupts start out disabled/masked.
+	 * Our driver only uses the concept of masked and always keeps
+	 * things enabled, so for us that's all masked and all enabled.
+	 */
+	writel_relaxed(0xffffffff, bank->reg_base + GPIO_INTMASK);
+	writel_relaxed(0xffffffff, bank->reg_base + GPIO_PORTS_EOI);
+	writel_relaxed(0xffffffff, bank->reg_base + GPIO_INTEN);
+	gc->mask_cache = 0xffffffff;
+
+	irq_set_chained_handler_and_data(bank->irq,
+					 rockchip_irq_demux, bank);
+
+	return 0;
+}
+
+static int rockchip_gpiolib_register(struct rockchip_pin_bank *bank)
+{
+	struct gpio_chip *gc;
+	int ret;
+
+	bank->gpio_chip = rockchip_gpiolib_chip;
+
+	gc = &bank->gpio_chip;
+	gc->base = bank->pin_base;
+	gc->ngpio = bank->nr_pins;
+	gc->label = bank->name;
+	gc->parent = bank->dev;
+#ifdef CONFIG_OF_GPIO
+	gc->of_node = of_node_get(bank->of_node);
+#endif
+
+	ret = gpiochip_add_data(gc, bank);
+	if (ret) {
+		dev_err(bank->dev, "failed to add gpiochip %s, %d\n",
+			gc->label, ret);
+		return ret;
+	}
+
+	/*
+	 * For DeviceTree-supported systems, the gpio core checks the
+	 * pinctrl's device node for the "gpio-ranges" property.
+	 * If it is present, it takes care of adding the pin ranges
+	 * for the driver. In this case the driver can skip ahead.
+	 *
+	 * In order to remain compatible with older, existing DeviceTree
+	 * files which don't set the "gpio-ranges" property or systems that
+	 * utilize ACPI the driver has to call gpiochip_add_pin_range().
+	 */
+	if (!of_property_read_bool(bank->of_node, "gpio-ranges")) {
+		struct device_node *pctlnp = of_get_parent(bank->of_node);
+		struct pinctrl_dev *pctldev = NULL;
+
+		if (!pctlnp)
+			return -ENODATA;
+
+		pctldev = of_pinctrl_get(pctlnp);
+		if (!pctldev)
+			return -ENODEV;
+
+		ret = gpiochip_add_pin_range(gc, dev_name(pctldev->dev), 0,
+					     gc->base, gc->ngpio);
+		if (ret) {
+			dev_err(bank->dev, "Failed to add pin range\n");
+			goto fail;
+		}
+	}
+
+	ret = rockchip_interrupts_register(bank);
+	if (ret) {
+		dev_err(bank->dev, "failed to register interrupt, %d\n", ret);
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	gpiochip_remove(&bank->gpio_chip);
+
+	return ret;
+}
+
+static int rockchip_get_bank_data(struct rockchip_pin_bank *bank)
+{
+	struct resource res;
+
+	if (of_address_to_resource(bank->of_node, 0, &res)) {
+		dev_err(bank->dev, "cannot find IO resource for bank\n");
+		return -ENOENT;
+	}
+
+	bank->reg_base = devm_ioremap_resource(bank->dev, &res);
+	if (IS_ERR(bank->reg_base))
+		return PTR_ERR(bank->reg_base);
+
+	bank->irq = irq_of_parse_and_map(bank->of_node, 0);
+
+	bank->clk = of_clk_get(bank->of_node, 0);
+	if (!IS_ERR(bank->clk))
+		return clk_prepare_enable(bank->clk);
+
+	bank->clk = NULL;
+	return 0;
+}
+
+static struct rockchip_pin_bank *
+rockchip_gpio_find_bank(struct pinctrl_dev *pctldev, int id)
+{
+	struct rockchip_pinctrl *info;
+	struct rockchip_pin_bank *bank;
+	int i, found = 0;
+
+	info = pinctrl_dev_get_drvdata(pctldev);
+	bank = info->ctrl->pin_banks;
+	for (i = 0; i < info->ctrl->nr_banks; i++, bank++) {
+		if (bank->bank_num == id) {
+			found = 1;
+			break;
+		}
+	}
+
+	return found ? bank : NULL;
+}
+
+static int rockchip_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *pctlnp = of_get_parent(np);
+	struct pinctrl_dev *pctldev = NULL;
+	struct rockchip_pin_bank *bank = NULL;
+	static int gpio;
+	int id, ret;
+
+	if (!np || !pctlnp)
+		return -ENODEV;
+
+	pctldev = of_pinctrl_get(pctlnp);
+	if (!pctldev)
+		return -EPROBE_DEFER;
+
+	id = of_alias_get_id(np, "gpio");
+	if (id < 0)
+		id = gpio++;
+
+	bank = rockchip_gpio_find_bank(pctldev, id);
+	if (!bank)
+		return -EINVAL;
+
+	bank->dev = dev;
+	bank->of_node = np;
+
+	raw_spin_lock_init(&bank->slock);
+
+	ret = rockchip_get_bank_data(bank);
+	if (ret)
+		return ret;
+
+	ret = rockchip_gpiolib_register(bank);
+	if (ret) {
+		clk_disable_unprepare(bank->clk);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, bank);
+	dev_info(dev, "probed %pOF\n", np);
+
+	return 0;
+}
+
+static int rockchip_gpio_remove(struct platform_device *pdev)
+{
+	struct rockchip_pin_bank *bank = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(bank->clk);
+	gpiochip_remove(&bank->gpio_chip);
+
+	return 0;
+}
+
+static const struct of_device_id rockchip_gpio_match[] = {
+	{ .compatible = "rockchip,gpio-bank", },
+	{ .compatible = "rockchip,rk3188-gpio-bank0" },
+	{ },
+};
+
+static struct platform_driver rockchip_gpio_driver = {
+	.probe		= rockchip_gpio_probe,
+	.remove		= rockchip_gpio_remove,
+	.driver		= {
+		.name	= "rockchip-gpio",
+		.of_match_table = rockchip_gpio_match,
+	},
+};
+
+static int __init rockchip_gpio_init(void)
+{
+	return platform_driver_register(&rockchip_gpio_driver);
+}
+postcore_initcall(rockchip_gpio_init);
+
+static void __exit rockchip_gpio_exit(void)
+{
+	platform_driver_unregister(&rockchip_gpio_driver);
+}
+module_exit(rockchip_gpio_exit);
+
+MODULE_DESCRIPTION("Rockchip gpio driver");
+MODULE_ALIAS("platform:rockchip-gpio");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, rockchip_gpio_match);
-- 
2.25.1