drivers/gpio/gpio-nct6694.c - pub/scm/linux/kernel/git/gregkh/tty - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Nuvoton NCT6694 GPIO controller driver based on USB interface.
  *
  * Copyright (C) 2025 Nuvoton Technology Corp.
  */

 #include <linux/bits.h>
 #include <linux/gpio/driver.h>
 #include <linux/idr.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/nct6694.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>

 /*
  * USB command module type for NCT6694 GPIO controller.
  * This defines the module type used for communication with the NCT6694
  * GPIO controller over the USB interface.
  */
 #define NCT6694_GPIO_MOD	0xFF

 #define NCT6694_GPIO_VER	0x90
 #define NCT6694_GPIO_VALID	0x110
 #define NCT6694_GPI_DATA	0x120
 #define NCT6694_GPO_DIR		0x170
 #define NCT6694_GPO_TYPE	0x180
 #define NCT6694_GPO_DATA	0x190

 #define NCT6694_GPI_STS		0x130
 #define NCT6694_GPI_CLR		0x140
 #define NCT6694_GPI_FALLING	0x150
 #define NCT6694_GPI_RISING	0x160

 #define NCT6694_NR_GPIO		8

 struct nct6694_gpio_data {
 	struct nct6694 *nct6694;
 	struct gpio_chip gpio;
 	struct mutex lock;
 	/* Protect irq operation */
 	struct mutex irq_lock;

 	unsigned char reg_val;
 	unsigned char irq_trig_falling;
 	unsigned char irq_trig_rising;

 	/* Current gpio group */
 	unsigned char group;
 	int irq;
 };

 static int nct6694_get_direction(struct gpio_chip *gpio, unsigned int offset)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	const struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	return !(BIT(offset) & data->reg_val);
 }

 static int nct6694_direction_input(struct gpio_chip *gpio, unsigned int offset)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	const struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	data->reg_val &= ~BIT(offset);

 	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
 }

 static int nct6694_direction_output(struct gpio_chip *gpio,
 				    unsigned int offset, int val)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	/* Set direction to output */
 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	data->reg_val |= BIT(offset);
 	ret = nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	/* Then set output level */
 	cmd_hd.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group);
 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	if (val)
 		data->reg_val |= BIT(offset);
 	else
 		data->reg_val &= ~BIT(offset);

 	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
 }

 static int nct6694_get_value(struct gpio_chip *gpio, unsigned int offset)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	if (BIT(offset) & data->reg_val) {
 		cmd_hd.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group);
 		ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 		if (ret < 0)
 			return ret;

 		return !!(BIT(offset) & data->reg_val);
 	}

 	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_DATA + data->group);
 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	return !!(BIT(offset) & data->reg_val);
 }

 static int nct6694_set_value(struct gpio_chip *gpio, unsigned int offset,
 			     int val)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	const struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	if (val)
 		data->reg_val |= BIT(offset);
 	else
 		data->reg_val &= ~BIT(offset);

 	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
 }

 static int nct6694_set_config(struct gpio_chip *gpio, unsigned int offset,
 			      unsigned long config)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	const struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPO_TYPE + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	switch (pinconf_to_config_param(config)) {
 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 		data->reg_val |= BIT(offset);
 		break;
 	case PIN_CONFIG_DRIVE_PUSH_PULL:
 		data->reg_val &= ~BIT(offset);
 		break;
 	default:
 		return -ENOTSUPP;
 	}

 	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
 }

 static int nct6694_init_valid_mask(struct gpio_chip *gpio,
 				   unsigned long *valid_mask,
 				   unsigned int ngpios)
 {
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	const struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPIO_VALID + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret < 0)
 		return ret;

 	*valid_mask = data->reg_val;

 	return ret;
 }

 static irqreturn_t nct6694_irq_handler(int irq, void *priv)
 {
 	struct nct6694_gpio_data *data = priv;
 	struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPI_STS + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	unsigned char status;
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	if (ret)
 		return IRQ_NONE;

 	status = data->reg_val;

 	while (status) {
 		int bit = __ffs(status);

 		data->reg_val = BIT(bit);
 		handle_nested_irq(irq_find_mapping(data->gpio.irq.domain, bit));
 		status &= ~BIT(bit);
 		cmd_hd.offset = cpu_to_le16(NCT6694_GPI_CLR + data->group);
 		nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
 	}

 	return IRQ_HANDLED;
 }

 static int nct6694_get_irq_trig(struct nct6694_gpio_data *data)
 {
 	struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPI_FALLING + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};
 	int ret;

 	guard(mutex)(&data->lock);

 	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->irq_trig_falling);
 	if (ret)
 		return ret;

 	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_RISING + data->group);
 	return nct6694_read_msg(data->nct6694, &cmd_hd, &data->irq_trig_rising);
 }

 static void nct6694_irq_mask(struct irq_data *d)
 {
 	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
 	irq_hw_number_t hwirq = irqd_to_hwirq(d);

 	gpiochip_disable_irq(gpio, hwirq);
 }

 static void nct6694_irq_unmask(struct irq_data *d)
 {
 	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
 	irq_hw_number_t hwirq = irqd_to_hwirq(d);

 	gpiochip_enable_irq(gpio, hwirq);
 }

 static int nct6694_irq_set_type(struct irq_data *d, unsigned int type)
 {
 	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	irq_hw_number_t hwirq = irqd_to_hwirq(d);

 	guard(mutex)(&data->lock);

 	switch (type) {
 	case IRQ_TYPE_EDGE_RISING:
 		data->irq_trig_rising |= BIT(hwirq);
 		break;

 	case IRQ_TYPE_EDGE_FALLING:
 		data->irq_trig_falling |= BIT(hwirq);
 		break;

 	case IRQ_TYPE_EDGE_BOTH:
 		data->irq_trig_rising |= BIT(hwirq);
 		data->irq_trig_falling |= BIT(hwirq);
 		break;

 	default:
 		return -ENOTSUPP;
 	}

 	return 0;
 }

 static void nct6694_irq_bus_lock(struct irq_data *d)
 {
 	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);

 	mutex_lock(&data->irq_lock);
 }

 static void nct6694_irq_bus_sync_unlock(struct irq_data *d)
 {
 	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
 	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
 	struct nct6694_cmd_header cmd_hd = {
 		.mod = NCT6694_GPIO_MOD,
 		.offset = cpu_to_le16(NCT6694_GPI_FALLING + data->group),
 		.len = cpu_to_le16(sizeof(data->reg_val))
 	};

 	scoped_guard(mutex, &data->lock) {
 		nct6694_write_msg(data->nct6694, &cmd_hd, &data->irq_trig_falling);

 		cmd_hd.offset = cpu_to_le16(NCT6694_GPI_RISING + data->group);
 		nct6694_write_msg(data->nct6694, &cmd_hd, &data->irq_trig_rising);
 	}

 	mutex_unlock(&data->irq_lock);
 }

 static const struct irq_chip nct6694_irq_chip = {
 	.name			= "gpio-nct6694",
 	.irq_mask		= nct6694_irq_mask,
 	.irq_unmask		= nct6694_irq_unmask,
 	.irq_set_type		= nct6694_irq_set_type,
 	.irq_bus_lock		= nct6694_irq_bus_lock,
 	.irq_bus_sync_unlock	= nct6694_irq_bus_sync_unlock,
 	.flags			= IRQCHIP_IMMUTABLE,
 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };

 static void nct6694_irq_dispose_mapping(void *d)
 {
 	struct nct6694_gpio_data *data = d;

 	irq_dispose_mapping(data->irq);
 }

 static void nct6694_gpio_ida_free(void *d)
 {
 	struct nct6694_gpio_data *data = d;
 	struct nct6694 *nct6694 = data->nct6694;

 	ida_free(&nct6694->gpio_ida, data->group);
 }

 static int nct6694_gpio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct nct6694 *nct6694 = dev_get_drvdata(dev->parent);
 	struct nct6694_gpio_data *data;
 	struct gpio_irq_chip *girq;
 	int ret, i;
 	char **names;

 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->nct6694 = nct6694;

 	ret = ida_alloc(&nct6694->gpio_ida, GFP_KERNEL);
 	if (ret < 0)
 		return ret;
 	data->group = ret;

 	ret = devm_add_action_or_reset(dev, nct6694_gpio_ida_free, data);
 	if (ret)
 		return ret;

 	names = devm_kcalloc(dev, NCT6694_NR_GPIO, sizeof(char *),
 			     GFP_KERNEL);
 	if (!names)
 		return -ENOMEM;

 	for (i = 0; i < NCT6694_NR_GPIO; i++) {
 		names[i] = devm_kasprintf(dev, GFP_KERNEL, "GPIO%X%d",
 					  data->group, i);
 		if (!names[i])
 			return -ENOMEM;
 	}

 	data->irq = irq_create_mapping(nct6694->domain,
 				       NCT6694_IRQ_GPIO0 + data->group);
 	if (!data->irq)
 		return -EINVAL;

 	ret = devm_add_action_or_reset(dev, nct6694_irq_dispose_mapping, data);
 	if (ret)
 		return ret;

 	data->gpio.names		= (const char * const*)names;
 	data->gpio.label		= pdev->name;
 	data->gpio.direction_input	= nct6694_direction_input;
 	data->gpio.get			= nct6694_get_value;
 	data->gpio.direction_output	= nct6694_direction_output;
 	data->gpio.set			= nct6694_set_value;
 	data->gpio.get_direction	= nct6694_get_direction;
 	data->gpio.set_config		= nct6694_set_config;
 	data->gpio.init_valid_mask	= nct6694_init_valid_mask;
 	data->gpio.base			= -1;
 	data->gpio.can_sleep		= false;
 	data->gpio.owner		= THIS_MODULE;
 	data->gpio.ngpio		= NCT6694_NR_GPIO;

 	platform_set_drvdata(pdev, data);

 	ret = devm_mutex_init(dev, &data->lock);
 	if (ret)
 		return ret;

 	ret = devm_mutex_init(dev, &data->irq_lock);
 	if (ret)
 		return ret;

 	ret = nct6694_get_irq_trig(data);
 	if (ret) {
 		dev_err_probe(dev, ret, "Failed to get irq trigger type\n");
 		return ret;
 	}

 	girq = &data->gpio.irq;
 	gpio_irq_chip_set_chip(girq, &nct6694_irq_chip);
 	girq->parent_handler = NULL;
 	girq->num_parents = 0;
 	girq->parents = NULL;
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_level_irq;
 	girq->threaded = true;

 	ret = devm_request_threaded_irq(dev, data->irq, NULL, nct6694_irq_handler,
 					IRQF_ONESHOT | IRQF_SHARED,
 					"gpio-nct6694", data);
 	if (ret) {
 		dev_err_probe(dev, ret, "Failed to request irq\n");
 		return ret;
 	}

 	return devm_gpiochip_add_data(dev, &data->gpio, data);
 }

 static struct platform_driver nct6694_gpio_driver = {
 	.driver = {
 		.name	= "nct6694-gpio",
 	},
 	.probe		= nct6694_gpio_probe,
 };

 module_platform_driver(nct6694_gpio_driver);

 MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
 MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:nct6694-gpio");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Nuvoton NCT6694 GPIO controller driver based on USB interface.
	*
	* Copyright (C) 2025 Nuvoton Technology Corp.
	*/

	#include <linux/bits.h>
	#include <linux/gpio/driver.h>
	#include <linux/idr.h>
	#include <linux/interrupt.h>
	#include <linux/mfd/nct6694.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>

	/*
	* USB command module type for NCT6694 GPIO controller.
	* This defines the module type used for communication with the NCT6694
	* GPIO controller over the USB interface.
	*/
	#define NCT6694_GPIO_MOD 0xFF

	#define NCT6694_GPIO_VER 0x90
	#define NCT6694_GPIO_VALID 0x110
	#define NCT6694_GPI_DATA 0x120
	#define NCT6694_GPO_DIR 0x170
	#define NCT6694_GPO_TYPE 0x180
	#define NCT6694_GPO_DATA 0x190

	#define NCT6694_GPI_STS 0x130
	#define NCT6694_GPI_CLR 0x140
	#define NCT6694_GPI_FALLING 0x150
	#define NCT6694_GPI_RISING 0x160

	#define NCT6694_NR_GPIO 8

	struct nct6694_gpio_data {
	struct nct6694 *nct6694;
	struct gpio_chip gpio;
	struct mutex lock;
	/* Protect irq operation */
	struct mutex irq_lock;

	unsigned char reg_val;
	unsigned char irq_trig_falling;
	unsigned char irq_trig_rising;

	/* Current gpio group */
	unsigned char group;
	int irq;
	};

	static int nct6694_get_direction(struct gpio_chip *gpio, unsigned int offset)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	const struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	return !(BIT(offset) & data->reg_val);
	}

	static int nct6694_direction_input(struct gpio_chip *gpio, unsigned int offset)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	const struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	data->reg_val &= ~BIT(offset);

	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
	}

	static int nct6694_direction_output(struct gpio_chip *gpio,
	unsigned int offset, int val)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	/* Set direction to output */
	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	data->reg_val \|= BIT(offset);
	ret = nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	/* Then set output level */
	cmd_hd.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group);
	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	if (val)
	data->reg_val \|= BIT(offset);
	else
	data->reg_val &= ~BIT(offset);

	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
	}

	static int nct6694_get_value(struct gpio_chip *gpio, unsigned int offset)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	if (BIT(offset) & data->reg_val) {
	cmd_hd.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group);
	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	return !!(BIT(offset) & data->reg_val);
	}

	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_DATA + data->group);
	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	return !!(BIT(offset) & data->reg_val);
	}

	static int nct6694_set_value(struct gpio_chip *gpio, unsigned int offset,
	int val)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	const struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	if (val)
	data->reg_val \|= BIT(offset);
	else
	data->reg_val &= ~BIT(offset);

	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
	}

	static int nct6694_set_config(struct gpio_chip *gpio, unsigned int offset,
	unsigned long config)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	const struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPO_TYPE + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	switch (pinconf_to_config_param(config)) {
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
	data->reg_val \|= BIT(offset);
	break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
	data->reg_val &= ~BIT(offset);
	break;
	default:
	return -ENOTSUPP;
	}

	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
	}

	static int nct6694_init_valid_mask(struct gpio_chip *gpio,
	unsigned long *valid_mask,
	unsigned int ngpios)
	{
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	const struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPIO_VALID + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret < 0)
	return ret;

	*valid_mask = data->reg_val;

	return ret;
	}

	static irqreturn_t nct6694_irq_handler(int irq, void *priv)
	{
	struct nct6694_gpio_data *data = priv;
	struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPI_STS + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	unsigned char status;
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
	if (ret)
	return IRQ_NONE;

	status = data->reg_val;

	while (status) {
	int bit = __ffs(status);

	data->reg_val = BIT(bit);
	handle_nested_irq(irq_find_mapping(data->gpio.irq.domain, bit));
	status &= ~BIT(bit);
	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_CLR + data->group);
	nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
	}

	return IRQ_HANDLED;
	}

	static int nct6694_get_irq_trig(struct nct6694_gpio_data *data)
	{
	struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPI_FALLING + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};
	int ret;

	guard(mutex)(&data->lock);

	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->irq_trig_falling);
	if (ret)
	return ret;

	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_RISING + data->group);
	return nct6694_read_msg(data->nct6694, &cmd_hd, &data->irq_trig_rising);
	}

	static void nct6694_irq_mask(struct irq_data *d)
	{
	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
	irq_hw_number_t hwirq = irqd_to_hwirq(d);

	gpiochip_disable_irq(gpio, hwirq);
	}

	static void nct6694_irq_unmask(struct irq_data *d)
	{
	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
	irq_hw_number_t hwirq = irqd_to_hwirq(d);

	gpiochip_enable_irq(gpio, hwirq);
	}

	static int nct6694_irq_set_type(struct irq_data *d, unsigned int type)
	{
	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	irq_hw_number_t hwirq = irqd_to_hwirq(d);

	guard(mutex)(&data->lock);

	switch (type) {
	case IRQ_TYPE_EDGE_RISING:
	data->irq_trig_rising \|= BIT(hwirq);
	break;

	case IRQ_TYPE_EDGE_FALLING:
	data->irq_trig_falling \|= BIT(hwirq);
	break;

	case IRQ_TYPE_EDGE_BOTH:
	data->irq_trig_rising \|= BIT(hwirq);
	data->irq_trig_falling \|= BIT(hwirq);
	break;

	default:
	return -ENOTSUPP;
	}

	return 0;
	}

	static void nct6694_irq_bus_lock(struct irq_data *d)
	{
	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);

	mutex_lock(&data->irq_lock);
	}

	static void nct6694_irq_bus_sync_unlock(struct irq_data *d)
	{
	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
	struct nct6694_cmd_header cmd_hd = {
	.mod = NCT6694_GPIO_MOD,
	.offset = cpu_to_le16(NCT6694_GPI_FALLING + data->group),
	.len = cpu_to_le16(sizeof(data->reg_val))
	};

	scoped_guard(mutex, &data->lock) {
	nct6694_write_msg(data->nct6694, &cmd_hd, &data->irq_trig_falling);

	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_RISING + data->group);
	nct6694_write_msg(data->nct6694, &cmd_hd, &data->irq_trig_rising);
	}

	mutex_unlock(&data->irq_lock);
	}

	static const struct irq_chip nct6694_irq_chip = {
	.name = "gpio-nct6694",
	.irq_mask = nct6694_irq_mask,
	.irq_unmask = nct6694_irq_unmask,
	.irq_set_type = nct6694_irq_set_type,
	.irq_bus_lock = nct6694_irq_bus_lock,
	.irq_bus_sync_unlock = nct6694_irq_bus_sync_unlock,
	.flags = IRQCHIP_IMMUTABLE,
	GPIOCHIP_IRQ_RESOURCE_HELPERS,
	};

	static void nct6694_irq_dispose_mapping(void *d)
	{
	struct nct6694_gpio_data *data = d;

	irq_dispose_mapping(data->irq);
	}

	static void nct6694_gpio_ida_free(void *d)
	{
	struct nct6694_gpio_data *data = d;
	struct nct6694 *nct6694 = data->nct6694;

	ida_free(&nct6694->gpio_ida, data->group);
	}

	static int nct6694_gpio_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct nct6694 *nct6694 = dev_get_drvdata(dev->parent);
	struct nct6694_gpio_data *data;
	struct gpio_irq_chip *girq;
	int ret, i;
	char **names;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->nct6694 = nct6694;

	ret = ida_alloc(&nct6694->gpio_ida, GFP_KERNEL);
	if (ret < 0)
	return ret;
	data->group = ret;

	ret = devm_add_action_or_reset(dev, nct6694_gpio_ida_free, data);
	if (ret)
	return ret;

	names = devm_kcalloc(dev, NCT6694_NR_GPIO, sizeof(char *),
	GFP_KERNEL);
	if (!names)
	return -ENOMEM;

	for (i = 0; i < NCT6694_NR_GPIO; i++) {
	names[i] = devm_kasprintf(dev, GFP_KERNEL, "GPIO%X%d",
	data->group, i);
	if (!names[i])
	return -ENOMEM;
	}

	data->irq = irq_create_mapping(nct6694->domain,
	NCT6694_IRQ_GPIO0 + data->group);
	if (!data->irq)
	return -EINVAL;

	ret = devm_add_action_or_reset(dev, nct6694_irq_dispose_mapping, data);
	if (ret)
	return ret;

	data->gpio.names = (const char * const*)names;
	data->gpio.label = pdev->name;
	data->gpio.direction_input = nct6694_direction_input;
	data->gpio.get = nct6694_get_value;
	data->gpio.direction_output = nct6694_direction_output;
	data->gpio.set = nct6694_set_value;
	data->gpio.get_direction = nct6694_get_direction;
	data->gpio.set_config = nct6694_set_config;
	data->gpio.init_valid_mask = nct6694_init_valid_mask;
	data->gpio.base = -1;
	data->gpio.can_sleep = false;
	data->gpio.owner = THIS_MODULE;
	data->gpio.ngpio = NCT6694_NR_GPIO;

	platform_set_drvdata(pdev, data);

	ret = devm_mutex_init(dev, &data->lock);
	if (ret)
	return ret;

	ret = devm_mutex_init(dev, &data->irq_lock);
	if (ret)
	return ret;

	ret = nct6694_get_irq_trig(data);
	if (ret) {
	dev_err_probe(dev, ret, "Failed to get irq trigger type\n");
	return ret;
	}

	girq = &data->gpio.irq;
	gpio_irq_chip_set_chip(girq, &nct6694_irq_chip);
	girq->parent_handler = NULL;
	girq->num_parents = 0;
	girq->parents = NULL;
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_level_irq;
	girq->threaded = true;

	ret = devm_request_threaded_irq(dev, data->irq, NULL, nct6694_irq_handler,
	IRQF_ONESHOT \| IRQF_SHARED,
	"gpio-nct6694", data);
	if (ret) {
	dev_err_probe(dev, ret, "Failed to request irq\n");
	return ret;
	}

	return devm_gpiochip_add_data(dev, &data->gpio, data);
	}

	static struct platform_driver nct6694_gpio_driver = {
	.driver = {
	.name = "nct6694-gpio",
	},
	.probe = nct6694_gpio_probe,
	};

	module_platform_driver(nct6694_gpio_driver);

	MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
	MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:nct6694-gpio");