drivers/gpio/gpio-ljca.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Intel La Jolla Cove Adapter USB-GPIO driver
  *
  * Copyright (c) 2023, Intel Corporation.
  */

 #include <linux/acpi.h>
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/dev_printk.h>
 #include <linux/gpio/driver.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/mfd/ljca.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/types.h>

 /* GPIO commands */
 #define LJCA_GPIO_CONFIG	1
 #define LJCA_GPIO_READ		2
 #define LJCA_GPIO_WRITE		3
 #define LJCA_GPIO_INT_EVENT	4
 #define LJCA_GPIO_INT_MASK	5
 #define LJCA_GPIO_INT_UNMASK	6

 #define LJCA_GPIO_CONF_DISABLE		BIT(0)
 #define LJCA_GPIO_CONF_INPUT		BIT(1)
 #define LJCA_GPIO_CONF_OUTPUT		BIT(2)
 #define LJCA_GPIO_CONF_PULLUP		BIT(3)
 #define LJCA_GPIO_CONF_PULLDOWN		BIT(4)
 #define LJCA_GPIO_CONF_DEFAULT		BIT(5)
 #define LJCA_GPIO_CONF_INTERRUPT	BIT(6)
 #define LJCA_GPIO_INT_TYPE		BIT(7)

 #define LJCA_GPIO_CONF_EDGE	FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
 #define LJCA_GPIO_CONF_LEVEL	FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)

 /* Intentional overlap with PULLUP / PULLDOWN */
 #define LJCA_GPIO_CONF_SET	BIT(3)
 #define LJCA_GPIO_CONF_CLR	BIT(4)

 struct gpio_op {
 	u8 index;
 	u8 value;
 } __packed;

 struct gpio_packet {
 	u8 num;
 	struct gpio_op item[];
 } __packed;

 #define LJCA_GPIO_BUF_SIZE 60
 struct ljca_gpio_dev {
 	struct platform_device *pdev;
 	struct gpio_chip gc;
 	struct ljca_gpio_info *gpio_info;
 	DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
 	DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
 	DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
 	u8 *connect_mode;
 	/* mutex to protect irq bus */
 	struct mutex irq_lock;
 	struct work_struct work;
 	/* lock to protect package transfer to Hardware */
 	struct mutex trans_lock;

 	u8 obuf[LJCA_GPIO_BUF_SIZE];
 	u8 ibuf[LJCA_GPIO_BUF_SIZE];
 };

 static int gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, u8 config)
 {
 	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
 	int ret;

 	mutex_lock(&ljca_gpio->trans_lock);
 	packet->item[0].index = gpio_id;
 	packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id];
 	packet->num = 1;

 	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_CONFIG, packet,
 			    struct_size(packet, item, packet->num), NULL, NULL);
 	mutex_unlock(&ljca_gpio->trans_lock);
 	return ret;
 }

 static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
 {
 	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
 	struct gpio_packet *ack_packet = (struct gpio_packet *)ljca_gpio->ibuf;
 	unsigned int ibuf_len = LJCA_GPIO_BUF_SIZE;
 	int ret;

 	mutex_lock(&ljca_gpio->trans_lock);
 	packet->num = 1;
 	packet->item[0].index = gpio_id;
 	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_READ, packet,
 			    struct_size(packet, item, packet->num), ljca_gpio->ibuf, &ibuf_len);
 	if (ret)
 		goto out_unlock;

 	if (!ibuf_len || ack_packet->num != packet->num) {
 		dev_err(&ljca_gpio->pdev->dev, "failed gpio_id:%u %u", gpio_id, ack_packet->num);
 		ret = -EIO;
 	}

 out_unlock:
 	mutex_unlock(&ljca_gpio->trans_lock);
 	if (ret)
 		return ret;
 	return ack_packet->item[0].value > 0;
 }

 static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
 			   int value)
 {
 	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
 	int ret;

 	mutex_lock(&ljca_gpio->trans_lock);
 	packet->num = 1;
 	packet->item[0].index = gpio_id;
 	packet->item[0].value = value & 1;

 	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_WRITE, packet,
 			    struct_size(packet, item, packet->num), NULL, NULL);
 	mutex_unlock(&ljca_gpio->trans_lock);
 	return ret;
 }

 static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
 {
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

 	return ljca_gpio_read(ljca_gpio, offset);
 }

 static void ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
 				int val)
 {
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 	int ret;

 	ret = ljca_gpio_write(ljca_gpio, offset, val);
 	if (ret)
 		dev_err(chip->parent, "offset:%u val:%d set value failed %d\n", offset, val, ret);
 }

 static int ljca_gpio_direction_input(struct gpio_chip *chip,
 				     unsigned int offset)
 {
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 	u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR;

 	return gpio_config(ljca_gpio, offset, config);
 }

 static int ljca_gpio_direction_output(struct gpio_chip *chip,
 				      unsigned int offset, int val)
 {
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 	u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR;
 	int ret;

 	ret = gpio_config(ljca_gpio, offset, config);
 	if (ret)
 		return ret;

 	ljca_gpio_set_value(chip, offset, val);
 	return 0;
 }

 static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
 				unsigned long config)
 {
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

 	ljca_gpio->connect_mode[offset] = 0;
 	switch (pinconf_to_config_param(config)) {
 	case PIN_CONFIG_BIAS_PULL_UP:
 		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP;
 		break;
 	case PIN_CONFIG_BIAS_PULL_DOWN:
 		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN;
 		break;
 	case PIN_CONFIG_DRIVE_PUSH_PULL:
 	case PIN_CONFIG_PERSIST_STATE:
 		break;
 	default:
 		return -ENOTSUPP;
 	}

 	return 0;
 }

 static int ljca_gpio_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
 				     unsigned int ngpios)
 {
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

 	WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
 	bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);

 	return 0;
 }

 static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
 					  unsigned int ngpios)
 {
 	ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
 }

 static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id, bool enable)
 {
 	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
 	int ret;

 	mutex_lock(&ljca_gpio->trans_lock);
 	packet->num = 1;
 	packet->item[0].index = gpio_id;
 	packet->item[0].value = 0;

 	ret = ljca_transfer(ljca_gpio->gpio_info->ljca,
 			    enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK, packet,
 			    struct_size(packet, item, packet->num), NULL, NULL);
 	mutex_unlock(&ljca_gpio->trans_lock);
 	return ret;
 }

 static void ljca_gpio_async(struct work_struct *work)
 {
 	struct ljca_gpio_dev *ljca_gpio = container_of(work, struct ljca_gpio_dev, work);
 	int gpio_id;
 	int unmasked;

 	for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
 		clear_bit(gpio_id, ljca_gpio->reenable_irqs);
 		unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
 		if (unmasked)
 			ljca_enable_irq(ljca_gpio, gpio_id, true);
 	}
 }

 static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data, int len)
 {
 	const struct gpio_packet *packet = evt_data;
 	struct ljca_gpio_dev *ljca_gpio = context;
 	int i;
 	int irq;

 	if (cmd != LJCA_GPIO_INT_EVENT)
 		return;

 	for (i = 0; i < packet->num; i++) {
 		irq = irq_find_mapping(ljca_gpio->gc.irq.domain, packet->item[i].index);
 		if (!irq) {
 			dev_err(ljca_gpio->gc.parent, "gpio_id %u does not mapped to IRQ yet\n",
 				packet->item[i].index);
 			return;
 		}

 		generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
 		set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
 	}

 	schedule_work(&ljca_gpio->work);
 }

 static void ljca_irq_unmask(struct irq_data *irqd)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 	int gpio_id = irqd_to_hwirq(irqd);

 	gpiochip_enable_irq(gc, gpio_id);
 	set_bit(gpio_id, ljca_gpio->unmasked_irqs);
 }

 static void ljca_irq_mask(struct irq_data *irqd)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 	int gpio_id = irqd_to_hwirq(irqd);

 	clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
 	gpiochip_disable_irq(gc, gpio_id);
 }

 static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 	int gpio_id = irqd_to_hwirq(irqd);

 	ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
 	switch (type) {
 	case IRQ_TYPE_LEVEL_HIGH:
 		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP);
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN);
 		break;
 	case IRQ_TYPE_EDGE_BOTH:
 		break;
 	case IRQ_TYPE_EDGE_RISING:
 		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP);
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static void ljca_irq_bus_lock(struct irq_data *irqd)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);

 	mutex_lock(&ljca_gpio->irq_lock);
 }

 static void ljca_irq_bus_unlock(struct irq_data *irqd)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 	int gpio_id = irqd_to_hwirq(irqd);
 	int enabled;
 	int unmasked;

 	enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
 	unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);

 	if (enabled != unmasked) {
 		if (unmasked) {
 			gpio_config(ljca_gpio, gpio_id, 0);
 			ljca_enable_irq(ljca_gpio, gpio_id, true);
 			set_bit(gpio_id, ljca_gpio->enabled_irqs);
 		} else {
 			ljca_enable_irq(ljca_gpio, gpio_id, false);
 			clear_bit(gpio_id, ljca_gpio->enabled_irqs);
 		}
 	}

 	mutex_unlock(&ljca_gpio->irq_lock);
 }

 static const struct irq_chip ljca_gpio_irqchip = {
 	.name = "ljca-irq",
 	.irq_mask = ljca_irq_mask,
 	.irq_unmask = ljca_irq_unmask,
 	.irq_set_type = ljca_irq_set_type,
 	.irq_bus_lock = ljca_irq_bus_lock,
 	.irq_bus_sync_unlock = ljca_irq_bus_unlock,
 	.flags = IRQCHIP_IMMUTABLE,
 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };

 static int ljca_gpio_probe(struct platform_device *pdev)
 {
 	struct ljca_gpio_dev *ljca_gpio;
 	struct gpio_irq_chip *girq;
 	int ret;

 	ljca_gpio = devm_kzalloc(&pdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
 	if (!ljca_gpio)
 		return -ENOMEM;

 	ljca_gpio->gpio_info = dev_get_platdata(&pdev->dev);
 	ljca_gpio->connect_mode = devm_kcalloc(&pdev->dev, ljca_gpio->gpio_info->num,
 					       sizeof(*ljca_gpio->connect_mode), GFP_KERNEL);
 	if (!ljca_gpio->connect_mode)
 		return -ENOMEM;

 	mutex_init(&ljca_gpio->irq_lock);
 	mutex_init(&ljca_gpio->trans_lock);
 	ljca_gpio->pdev = pdev;
 	ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
 	ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
 	ljca_gpio->gc.get = ljca_gpio_get_value;
 	ljca_gpio->gc.set = ljca_gpio_set_value;
 	ljca_gpio->gc.set_config = ljca_gpio_set_config;
 	ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
 	ljca_gpio->gc.can_sleep = true;
 	ljca_gpio->gc.parent = &pdev->dev;

 	ljca_gpio->gc.base = -1;
 	ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
 	ljca_gpio->gc.label = ACPI_COMPANION(&pdev->dev) ?
 			      acpi_dev_name(ACPI_COMPANION(&pdev->dev)) :
 			      dev_name(&pdev->dev);
 	ljca_gpio->gc.owner = THIS_MODULE;

 	platform_set_drvdata(pdev, ljca_gpio);
 	ljca_register_event_cb(ljca_gpio->gpio_info->ljca, ljca_gpio_event_cb, ljca_gpio);

 	girq = &ljca_gpio->gc.irq;
 	gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
 	girq->parent_handler = NULL;
 	girq->num_parents = 0;
 	girq->parents = NULL;
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_simple_irq;
 	girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;

 	INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
 	ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
 	if (ret) {
 		ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
 		mutex_destroy(&ljca_gpio->irq_lock);
 		mutex_destroy(&ljca_gpio->trans_lock);
 	}

 	return ret;
 }

 static int ljca_gpio_remove(struct platform_device *pdev)
 {
 	struct ljca_gpio_dev *ljca_gpio = platform_get_drvdata(pdev);

 	gpiochip_remove(&ljca_gpio->gc);
 	ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
 	mutex_destroy(&ljca_gpio->irq_lock);
 	mutex_destroy(&ljca_gpio->trans_lock);
 	return 0;
 }

 #define LJCA_GPIO_DRV_NAME "ljca-gpio"
 static const struct platform_device_id ljca_gpio_id[] = {
 	{ LJCA_GPIO_DRV_NAME, 0 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(platform, ljca_gpio_id);

 static struct platform_driver ljca_gpio_driver = {
 	.driver.name = LJCA_GPIO_DRV_NAME,
 	.probe = ljca_gpio_probe,
 	.remove = ljca_gpio_remove,
 };
 module_platform_driver(ljca_gpio_driver);

 MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
 MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
 MODULE_AUTHOR("Zhang Lixu <lixu.zhang@intel.com>");
 MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
 MODULE_LICENSE("GPL");
 MODULE_IMPORT_NS(LJCA);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Intel La Jolla Cove Adapter USB-GPIO driver
	*
	* Copyright (c) 2023, Intel Corporation.
	*/

	#include <linux/acpi.h>
	#include <linux/bitfield.h>
	#include <linux/bitops.h>
	#include <linux/dev_printk.h>
	#include <linux/gpio/driver.h>
	#include <linux/irq.h>
	#include <linux/kernel.h>
	#include <linux/kref.h>
	#include <linux/mfd/ljca.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/types.h>

	/* GPIO commands */
	#define LJCA_GPIO_CONFIG 1
	#define LJCA_GPIO_READ 2
	#define LJCA_GPIO_WRITE 3
	#define LJCA_GPIO_INT_EVENT 4
	#define LJCA_GPIO_INT_MASK 5
	#define LJCA_GPIO_INT_UNMASK 6

	#define LJCA_GPIO_CONF_DISABLE BIT(0)
	#define LJCA_GPIO_CONF_INPUT BIT(1)
	#define LJCA_GPIO_CONF_OUTPUT BIT(2)
	#define LJCA_GPIO_CONF_PULLUP BIT(3)
	#define LJCA_GPIO_CONF_PULLDOWN BIT(4)
	#define LJCA_GPIO_CONF_DEFAULT BIT(5)
	#define LJCA_GPIO_CONF_INTERRUPT BIT(6)
	#define LJCA_GPIO_INT_TYPE BIT(7)

	#define LJCA_GPIO_CONF_EDGE FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
	#define LJCA_GPIO_CONF_LEVEL FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)

	/* Intentional overlap with PULLUP / PULLDOWN */
	#define LJCA_GPIO_CONF_SET BIT(3)
	#define LJCA_GPIO_CONF_CLR BIT(4)

	struct gpio_op {
	u8 index;
	u8 value;
	} __packed;

	struct gpio_packet {
	u8 num;
	struct gpio_op item[];
	} __packed;

	#define LJCA_GPIO_BUF_SIZE 60
	struct ljca_gpio_dev {
	struct platform_device *pdev;
	struct gpio_chip gc;
	struct ljca_gpio_info *gpio_info;
	DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
	DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
	DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
	u8 *connect_mode;
	/* mutex to protect irq bus */
	struct mutex irq_lock;
	struct work_struct work;
	/* lock to protect package transfer to Hardware */
	struct mutex trans_lock;

	u8 obuf[LJCA_GPIO_BUF_SIZE];
	u8 ibuf[LJCA_GPIO_BUF_SIZE];
	};

	static int gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, u8 config)
	{
	struct gpio_packet packet = (struct gpio_packet )ljca_gpio->obuf;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->item[0].index = gpio_id;
	packet->item[0].value = config \| ljca_gpio->connect_mode[gpio_id];
	packet->num = 1;

	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_CONFIG, packet,
	struct_size(packet, item, packet->num), NULL, NULL);
	mutex_unlock(&ljca_gpio->trans_lock);
	return ret;
	}

	static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
	{
	struct gpio_packet packet = (struct gpio_packet )ljca_gpio->obuf;
	struct gpio_packet ack_packet = (struct gpio_packet )ljca_gpio->ibuf;
	unsigned int ibuf_len = LJCA_GPIO_BUF_SIZE;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->num = 1;
	packet->item[0].index = gpio_id;
	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_READ, packet,
	struct_size(packet, item, packet->num), ljca_gpio->ibuf, &ibuf_len);
	if (ret)
	goto out_unlock;

	if (!ibuf_len \|\| ack_packet->num != packet->num) {
	dev_err(&ljca_gpio->pdev->dev, "failed gpio_id:%u %u", gpio_id, ack_packet->num);
	ret = -EIO;
	}

	out_unlock:
	mutex_unlock(&ljca_gpio->trans_lock);
	if (ret)
	return ret;
	return ack_packet->item[0].value > 0;
	}

	static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
	int value)
	{
	struct gpio_packet packet = (struct gpio_packet )ljca_gpio->obuf;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->num = 1;
	packet->item[0].index = gpio_id;
	packet->item[0].value = value & 1;

	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_WRITE, packet,
	struct_size(packet, item, packet->num), NULL, NULL);
	mutex_unlock(&ljca_gpio->trans_lock);
	return ret;
	}

	static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
	{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

	return ljca_gpio_read(ljca_gpio, offset);
	}

	static void ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
	int val)
	{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
	int ret;

	ret = ljca_gpio_write(ljca_gpio, offset, val);
	if (ret)
	dev_err(chip->parent, "offset:%u val:%d set value failed %d\n", offset, val, ret);
	}

	static int ljca_gpio_direction_input(struct gpio_chip *chip,
	unsigned int offset)
	{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
	u8 config = LJCA_GPIO_CONF_INPUT \| LJCA_GPIO_CONF_CLR;

	return gpio_config(ljca_gpio, offset, config);
	}

	static int ljca_gpio_direction_output(struct gpio_chip *chip,
	unsigned int offset, int val)
	{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
	u8 config = LJCA_GPIO_CONF_OUTPUT \| LJCA_GPIO_CONF_CLR;
	int ret;

	ret = gpio_config(ljca_gpio, offset, config);
	if (ret)
	return ret;

	ljca_gpio_set_value(chip, offset, val);
	return 0;
	}

	static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
	unsigned long config)
	{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

	ljca_gpio->connect_mode[offset] = 0;
	switch (pinconf_to_config_param(config)) {
	case PIN_CONFIG_BIAS_PULL_UP:
	ljca_gpio->connect_mode[offset] \|= LJCA_GPIO_CONF_PULLUP;
	break;
	case PIN_CONFIG_BIAS_PULL_DOWN:
	ljca_gpio->connect_mode[offset] \|= LJCA_GPIO_CONF_PULLDOWN;
	break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
	case PIN_CONFIG_PERSIST_STATE:
	break;
	default:
	return -ENOTSUPP;
	}

	return 0;
	}

	static int ljca_gpio_init_valid_mask(struct gpio_chip chip, unsigned long valid_mask,
	unsigned int ngpios)
	{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

	WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
	bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);

	return 0;
	}

	static void ljca_gpio_irq_init_valid_mask(struct gpio_chip chip, unsigned long valid_mask,
	unsigned int ngpios)
	{
	ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
	}

	static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id, bool enable)
	{
	struct gpio_packet packet = (struct gpio_packet )ljca_gpio->obuf;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->num = 1;
	packet->item[0].index = gpio_id;
	packet->item[0].value = 0;

	ret = ljca_transfer(ljca_gpio->gpio_info->ljca,
	enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK, packet,
	struct_size(packet, item, packet->num), NULL, NULL);
	mutex_unlock(&ljca_gpio->trans_lock);
	return ret;
	}

	static void ljca_gpio_async(struct work_struct *work)
	{
	struct ljca_gpio_dev *ljca_gpio = container_of(work, struct ljca_gpio_dev, work);
	int gpio_id;
	int unmasked;

	for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
	clear_bit(gpio_id, ljca_gpio->reenable_irqs);
	unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
	if (unmasked)
	ljca_enable_irq(ljca_gpio, gpio_id, true);
	}
	}

	static void ljca_gpio_event_cb(void context, u8 cmd, const void evt_data, int len)
	{
	const struct gpio_packet *packet = evt_data;
	struct ljca_gpio_dev *ljca_gpio = context;
	int i;
	int irq;

	if (cmd != LJCA_GPIO_INT_EVENT)
	return;

	for (i = 0; i < packet->num; i++) {
	irq = irq_find_mapping(ljca_gpio->gc.irq.domain, packet->item[i].index);
	if (!irq) {
	dev_err(ljca_gpio->gc.parent, "gpio_id %u does not mapped to IRQ yet\n",
	packet->item[i].index);
	return;
	}

	generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
	set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
	}

	schedule_work(&ljca_gpio->work);
	}

	static void ljca_irq_unmask(struct irq_data *irqd)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);

	gpiochip_enable_irq(gc, gpio_id);
	set_bit(gpio_id, ljca_gpio->unmasked_irqs);
	}

	static void ljca_irq_mask(struct irq_data *irqd)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);

	clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
	gpiochip_disable_irq(gc, gpio_id);
	}

	static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);

	ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
	switch (type) {
	case IRQ_TYPE_LEVEL_HIGH:
	ljca_gpio->connect_mode[gpio_id] \|= (LJCA_GPIO_CONF_LEVEL \| LJCA_GPIO_CONF_PULLUP);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	ljca_gpio->connect_mode[gpio_id] \|= (LJCA_GPIO_CONF_LEVEL \| LJCA_GPIO_CONF_PULLDOWN);
	break;
	case IRQ_TYPE_EDGE_BOTH:
	break;
	case IRQ_TYPE_EDGE_RISING:
	ljca_gpio->connect_mode[gpio_id] \|= (LJCA_GPIO_CONF_EDGE \| LJCA_GPIO_CONF_PULLUP);
	break;
	case IRQ_TYPE_EDGE_FALLING:
	ljca_gpio->connect_mode[gpio_id] \|= (LJCA_GPIO_CONF_EDGE \| LJCA_GPIO_CONF_PULLDOWN);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static void ljca_irq_bus_lock(struct irq_data *irqd)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);

	mutex_lock(&ljca_gpio->irq_lock);
	}

	static void ljca_irq_bus_unlock(struct irq_data *irqd)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);
	int enabled;
	int unmasked;

	enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
	unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);

	if (enabled != unmasked) {
	if (unmasked) {
	gpio_config(ljca_gpio, gpio_id, 0);
	ljca_enable_irq(ljca_gpio, gpio_id, true);
	set_bit(gpio_id, ljca_gpio->enabled_irqs);
	} else {
	ljca_enable_irq(ljca_gpio, gpio_id, false);
	clear_bit(gpio_id, ljca_gpio->enabled_irqs);
	}
	}

	mutex_unlock(&ljca_gpio->irq_lock);
	}

	static const struct irq_chip ljca_gpio_irqchip = {
	.name = "ljca-irq",
	.irq_mask = ljca_irq_mask,
	.irq_unmask = ljca_irq_unmask,
	.irq_set_type = ljca_irq_set_type,
	.irq_bus_lock = ljca_irq_bus_lock,
	.irq_bus_sync_unlock = ljca_irq_bus_unlock,
	.flags = IRQCHIP_IMMUTABLE,
	GPIOCHIP_IRQ_RESOURCE_HELPERS,
	};

	static int ljca_gpio_probe(struct platform_device *pdev)
	{
	struct ljca_gpio_dev *ljca_gpio;
	struct gpio_irq_chip *girq;
	int ret;

	ljca_gpio = devm_kzalloc(&pdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
	if (!ljca_gpio)
	return -ENOMEM;

	ljca_gpio->gpio_info = dev_get_platdata(&pdev->dev);
	ljca_gpio->connect_mode = devm_kcalloc(&pdev->dev, ljca_gpio->gpio_info->num,
	sizeof(*ljca_gpio->connect_mode), GFP_KERNEL);
	if (!ljca_gpio->connect_mode)
	return -ENOMEM;

	mutex_init(&ljca_gpio->irq_lock);
	mutex_init(&ljca_gpio->trans_lock);
	ljca_gpio->pdev = pdev;
	ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
	ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
	ljca_gpio->gc.get = ljca_gpio_get_value;
	ljca_gpio->gc.set = ljca_gpio_set_value;
	ljca_gpio->gc.set_config = ljca_gpio_set_config;
	ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
	ljca_gpio->gc.can_sleep = true;
	ljca_gpio->gc.parent = &pdev->dev;

	ljca_gpio->gc.base = -1;
	ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
	ljca_gpio->gc.label = ACPI_COMPANION(&pdev->dev) ?
	acpi_dev_name(ACPI_COMPANION(&pdev->dev)) :
	dev_name(&pdev->dev);
	ljca_gpio->gc.owner = THIS_MODULE;

	platform_set_drvdata(pdev, ljca_gpio);
	ljca_register_event_cb(ljca_gpio->gpio_info->ljca, ljca_gpio_event_cb, ljca_gpio);

	girq = &ljca_gpio->gc.irq;
	gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
	girq->parent_handler = NULL;
	girq->num_parents = 0;
	girq->parents = NULL;
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_simple_irq;
	girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;

	INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
	ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
	if (ret) {
	ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
	mutex_destroy(&ljca_gpio->irq_lock);
	mutex_destroy(&ljca_gpio->trans_lock);
	}

	return ret;
	}

	static int ljca_gpio_remove(struct platform_device *pdev)
	{
	struct ljca_gpio_dev *ljca_gpio = platform_get_drvdata(pdev);

	gpiochip_remove(&ljca_gpio->gc);
	ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
	mutex_destroy(&ljca_gpio->irq_lock);
	mutex_destroy(&ljca_gpio->trans_lock);
	return 0;
	}

	#define LJCA_GPIO_DRV_NAME "ljca-gpio"
	static const struct platform_device_id ljca_gpio_id[] = {
	{ LJCA_GPIO_DRV_NAME, 0 },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(platform, ljca_gpio_id);

	static struct platform_driver ljca_gpio_driver = {
	.driver.name = LJCA_GPIO_DRV_NAME,
	.probe = ljca_gpio_probe,
	.remove = ljca_gpio_remove,
	};
	module_platform_driver(ljca_gpio_driver);

	MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
	MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
	MODULE_AUTHOR("Zhang Lixu <lixu.zhang@intel.com>");
	MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
	MODULE_LICENSE("GPL");
	MODULE_IMPORT_NS(LJCA);