/*
   * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
   * Copyright (c) 2013,2014 Uplogix, Inc.
   * David Barksdale <dbarksdale@uplogix.com>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   */
  
  /*
   * The Silicon Labs CP2112 chip is a USB HID device which provides an
   * SMBus controller for talking to slave devices and 8 GPIO pins. The
   * host communicates with the CP2112 via raw HID reports.
   *
   * Data Sheet:
   *   http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
   * Programming Interface Specification:

   *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf

   */

  #include <linux/gpio.h>

  #include <linux/gpio/driver.h>

  #include <linux/hid.h>

  #include <linux/hidraw.h>

  #include <linux/i2c.h>
  #include <linux/module.h>
  #include <linux/nls.h>
  #include <linux/usb/ch9.h>
  #include "hid-ids.h"

  #define CP2112_REPORT_MAX_LENGTH		64
  #define CP2112_GPIO_CONFIG_LENGTH		5
  #define CP2112_GPIO_GET_LENGTH			2
  #define CP2112_GPIO_SET_LENGTH			3

  enum {
  	CP2112_GPIO_CONFIG		= 0x02,
  	CP2112_GPIO_GET			= 0x03,
  	CP2112_GPIO_SET			= 0x04,
  	CP2112_GET_VERSION_INFO		= 0x05,
  	CP2112_SMBUS_CONFIG		= 0x06,
  	CP2112_DATA_READ_REQUEST	= 0x10,
  	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,
  	CP2112_DATA_READ_FORCE_SEND	= 0x12,
  	CP2112_DATA_READ_RESPONSE	= 0x13,
  	CP2112_DATA_WRITE_REQUEST	= 0x14,
  	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,
  	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,
  	CP2112_CANCEL_TRANSFER		= 0x17,
  	CP2112_LOCK_BYTE		= 0x20,
  	CP2112_USB_CONFIG		= 0x21,
  	CP2112_MANUFACTURER_STRING	= 0x22,
  	CP2112_PRODUCT_STRING		= 0x23,
  	CP2112_SERIAL_STRING		= 0x24,
  };
  
  enum {
  	STATUS0_IDLE		= 0x00,
  	STATUS0_BUSY		= 0x01,
  	STATUS0_COMPLETE	= 0x02,
  	STATUS0_ERROR		= 0x03,
  };
  
  enum {
  	STATUS1_TIMEOUT_NACK		= 0x00,
  	STATUS1_TIMEOUT_BUS		= 0x01,
  	STATUS1_ARBITRATION_LOST	= 0x02,
  	STATUS1_READ_INCOMPLETE		= 0x03,
  	STATUS1_WRITE_INCOMPLETE	= 0x04,
  	STATUS1_SUCCESS			= 0x05,
  };
  
  struct cp2112_smbus_config_report {
  	u8 report;		/* CP2112_SMBUS_CONFIG */
  	__be32 clock_speed;	/* Hz */
  	u8 device_address;	/* Stored in the upper 7 bits */
  	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */
  	__be16 write_timeout;	/* ms, 0 = no timeout */
  	__be16 read_timeout;	/* ms, 0 = no timeout */
  	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */
  	__be16 retry_time;	/* # of retries, 0 = no limit */
  } __packed;
  
  struct cp2112_usb_config_report {
  	u8 report;	/* CP2112_USB_CONFIG */
  	__le16 vid;	/* Vendor ID */
  	__le16 pid;	/* Product ID */
  	u8 max_power;	/* Power requested in 2mA units */
  	u8 power_mode;	/* 0x00 = bus powered
  			   0x01 = self powered & regulator off
  			   0x02 = self powered & regulator on */
  	u8 release_major;
  	u8 release_minor;
  	u8 mask;	/* What fields to program */
  } __packed;
  
  struct cp2112_read_req_report {
  	u8 report;	/* CP2112_DATA_READ_REQUEST */
  	u8 slave_address;
  	__be16 length;
  } __packed;
  
  struct cp2112_write_read_req_report {
  	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */
  	u8 slave_address;
  	__be16 length;
  	u8 target_address_length;
  	u8 target_address[16];
  } __packed;
  
  struct cp2112_write_req_report {
  	u8 report;	/* CP2112_DATA_WRITE_REQUEST */
  	u8 slave_address;
  	u8 length;
  	u8 data[61];
  } __packed;
  
  struct cp2112_force_read_report {
  	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */
  	__be16 length;
  } __packed;
  
  struct cp2112_xfer_status_report {
  	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */
  	u8 status0;	/* STATUS0_* */
  	u8 status1;	/* STATUS1_* */
  	__be16 retries;
  	__be16 length;
  } __packed;
  
  struct cp2112_string_report {
  	u8 dummy;		/* force .string to be aligned */
  	u8 report;		/* CP2112_*_STRING */
  	u8 length;		/* length in bytes of everyting after .report */
  	u8 type;		/* USB_DT_STRING */
  	wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
  } __packed;
  
  /* Number of times to request transfer status before giving up waiting for a
     transfer to complete. This may need to be changed if SMBUS clock, retries,
     or read/write/scl_low timeout settings are changed. */
  static const int XFER_STATUS_RETRIES = 10;
  
  /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
     CP2112_TRANSFER_STATUS_RESPONSE. */
  static const int RESPONSE_TIMEOUT = 50;
  
  static const struct hid_device_id cp2112_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
  	{ }
  };
  MODULE_DEVICE_TABLE(hid, cp2112_devices);
  
  struct cp2112_device {
  	struct i2c_adapter adap;
  	struct hid_device *hdev;
  	wait_queue_head_t wait;
  	u8 read_data[61];
  	u8 read_length;

  	u8 hwversion;

  	int xfer_status;
  	atomic_t read_avail;
  	atomic_t xfer_avail;
  	struct gpio_chip gc;

  	u8 *in_out_buffer;

  	struct mutex lock;

  
  	struct gpio_desc *desc[8];
  	bool gpio_poll;
  	struct delayed_work gpio_poll_worker;
  	unsigned long irq_mask;
  	u8 gpio_prev_state;

  };
  
  static int gpio_push_pull = 0xFF;
  module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
  MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
  
  static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
  {

  	struct cp2112_device *dev = gpiochip_get_data(chip);

  	struct hid_device *hdev = dev->hdev;

  	u8 *buf = dev->in_out_buffer;

  	int ret;

  	mutex_lock(&dev->lock);

  	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,

  				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
  				 HID_REQ_GET_REPORT);
  	if (ret != CP2112_GPIO_CONFIG_LENGTH) {

  		hid_err(hdev, "error requesting GPIO config: %d
  ", ret);

  		if (ret >= 0)
  			ret = -EIO;

  		goto exit;

  	}
  
  	buf[1] &= ~(1 << offset);
  	buf[2] = gpio_push_pull;

  	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
  				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
  				 HID_REQ_SET_REPORT);

  	if (ret != CP2112_GPIO_CONFIG_LENGTH) {

  		hid_err(hdev, "error setting GPIO config: %d
  ", ret);

  		if (ret >= 0)
  			ret = -EIO;

  		goto exit;

  	}

  	ret = 0;
  
  exit:

  	mutex_unlock(&dev->lock);

  	return ret;

  }
  
  static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  {

  	struct cp2112_device *dev = gpiochip_get_data(chip);

  	struct hid_device *hdev = dev->hdev;

  	u8 *buf = dev->in_out_buffer;

  	int ret;

  	mutex_lock(&dev->lock);

  	buf[0] = CP2112_GPIO_SET;
  	buf[1] = value ? 0xff : 0;
  	buf[2] = 1 << offset;

  	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
  				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
  				 HID_REQ_SET_REPORT);

  	if (ret < 0)
  		hid_err(hdev, "error setting GPIO values: %d
  ", ret);

  	mutex_unlock(&dev->lock);

  }

  static int cp2112_gpio_get_all(struct gpio_chip *chip)

  {

  	struct cp2112_device *dev = gpiochip_get_data(chip);

  	struct hid_device *hdev = dev->hdev;

  	u8 *buf = dev->in_out_buffer;

  	int ret;

  	mutex_lock(&dev->lock);

  
  	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
  				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
  				 HID_REQ_GET_REPORT);
  	if (ret != CP2112_GPIO_GET_LENGTH) {

  		hid_err(hdev, "error requesting GPIO values: %d
  ", ret);

  		ret = ret < 0 ? ret : -EIO;
  		goto exit;

  	}

  	ret = buf[1];

  
  exit:

  	mutex_unlock(&dev->lock);

  
  	return ret;

  }

  static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
  {
  	int ret;
  
  	ret = cp2112_gpio_get_all(chip);
  	if (ret < 0)
  		return ret;
  
  	return (ret >> offset) & 1;
  }

  static int cp2112_gpio_direction_output(struct gpio_chip *chip,
  					unsigned offset, int value)
  {

  	struct cp2112_device *dev = gpiochip_get_data(chip);

  	struct hid_device *hdev = dev->hdev;

  	u8 *buf = dev->in_out_buffer;

  	int ret;

  	mutex_lock(&dev->lock);

  	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,

  				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
  				 HID_REQ_GET_REPORT);
  	if (ret != CP2112_GPIO_CONFIG_LENGTH) {

  		hid_err(hdev, "error requesting GPIO config: %d
  ", ret);

  		goto fail;

  	}
  
  	buf[1] |= 1 << offset;
  	buf[2] = gpio_push_pull;

  	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
  				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
  				 HID_REQ_SET_REPORT);

  	if (ret < 0) {
  		hid_err(hdev, "error setting GPIO config: %d
  ", ret);

  		goto fail;

  	}

  	mutex_unlock(&dev->lock);

  	/*
  	 * Set gpio value when output direction is already set,
  	 * as specified in AN495, Rev. 0.2, cpt. 4.4
  	 */
  	cp2112_gpio_set(chip, offset, value);

  	return 0;

  
  fail:

  	mutex_unlock(&dev->lock);

  	return ret < 0 ? ret : -EIO;

  }
  
  static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
  			  u8 *data, size_t count, unsigned char report_type)
  {
  	u8 *buf;
  	int ret;
  
  	buf = kmalloc(count, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;

  	ret = hid_hw_raw_request(hdev, report_number, buf, count,
  				       report_type, HID_REQ_GET_REPORT);

  	memcpy(data, buf, count);
  	kfree(buf);
  	return ret;
  }
  
  static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
  			     unsigned char report_type)
  {
  	u8 *buf;
  	int ret;
  
  	buf = kmemdup(data, count, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;

  	if (report_type == HID_OUTPUT_REPORT)
  		ret = hid_hw_output_report(hdev, buf, count);
  	else
  		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
  				HID_REQ_SET_REPORT);

  	kfree(buf);
  	return ret;
  }
  
  static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
  {
  	int ret = 0;
  
  	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
  	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
  	 * come in cp2112_raw_event or timeout. There will only be one of these
  	 * in flight at any one time. The timeout is extremely large and is a
  	 * last resort if the CP2112 has died. If we do timeout we don't expect
  	 * to receive the response which would cause data races, it's not like
  	 * we can do anything about it anyway.
  	 */
  	ret = wait_event_interruptible_timeout(dev->wait,
  		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
  	if (-ERESTARTSYS == ret)
  		return ret;
  	if (!ret)
  		return -ETIMEDOUT;
  
  	atomic_set(avail, 0);
  	return 0;
  }
  
  static int cp2112_xfer_status(struct cp2112_device *dev)
  {
  	struct hid_device *hdev = dev->hdev;
  	u8 buf[2];
  	int ret;
  
  	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
  	buf[1] = 0x01;
  	atomic_set(&dev->xfer_avail, 0);
  
  	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
  	if (ret < 0) {
  		hid_warn(hdev, "Error requesting status: %d
  ", ret);
  		return ret;
  	}
  
  	ret = cp2112_wait(dev, &dev->xfer_avail);
  	if (ret)
  		return ret;
  
  	return dev->xfer_status;
  }
  
  static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
  {
  	struct hid_device *hdev = dev->hdev;
  	struct cp2112_force_read_report report;
  	int ret;

  	if (size > sizeof(dev->read_data))
  		size = sizeof(dev->read_data);

  	report.report = CP2112_DATA_READ_FORCE_SEND;
  	report.length = cpu_to_be16(size);
  
  	atomic_set(&dev->read_avail, 0);
  
  	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
  				HID_OUTPUT_REPORT);
  	if (ret < 0) {
  		hid_warn(hdev, "Error requesting data: %d
  ", ret);
  		return ret;
  	}
  
  	ret = cp2112_wait(dev, &dev->read_avail);
  	if (ret)
  		return ret;

  	hid_dbg(hdev, "read %d of %zd bytes requested
  ",

  		dev->read_length, size);
  
  	if (size > dev->read_length)
  		size = dev->read_length;
  
  	memcpy(data, dev->read_data, size);
  	return dev->read_length;
  }
  
  static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
  {
  	struct cp2112_read_req_report *report = buf;
  
  	if (length < 1 || length > 512)
  		return -EINVAL;
  
  	report->report = CP2112_DATA_READ_REQUEST;
  	report->slave_address = slave_address << 1;
  	report->length = cpu_to_be16(length);
  	return sizeof(*report);
  }
  
  static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
  				 u8 command, u8 *data, u8 data_length)
  {
  	struct cp2112_write_read_req_report *report = buf;
  
  	if (length < 1 || length > 512
  	    || data_length > sizeof(report->target_address) - 1)
  		return -EINVAL;
  
  	report->report = CP2112_DATA_WRITE_READ_REQUEST;
  	report->slave_address = slave_address << 1;
  	report->length = cpu_to_be16(length);
  	report->target_address_length = data_length + 1;
  	report->target_address[0] = command;
  	memcpy(&report->target_address[1], data, data_length);
  	return data_length + 6;
  }
  
  static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
  			    u8 data_length)
  {
  	struct cp2112_write_req_report *report = buf;
  
  	if (data_length > sizeof(report->data) - 1)
  		return -EINVAL;
  
  	report->report = CP2112_DATA_WRITE_REQUEST;
  	report->slave_address = slave_address << 1;
  	report->length = data_length + 1;
  	report->data[0] = command;
  	memcpy(&report->data[1], data, data_length);
  	return data_length + 4;
  }

  static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
  				u8 data_length)
  {
  	struct cp2112_write_req_report *report = buf;
  
  	if (data_length > sizeof(report->data))
  		return -EINVAL;
  
  	report->report = CP2112_DATA_WRITE_REQUEST;
  	report->slave_address = slave_address << 1;
  	report->length = data_length;
  	memcpy(report->data, data, data_length);
  	return data_length + 3;
  }

  static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
  				     u8 *addr, int addr_length,
  				     int read_length)
  {
  	struct cp2112_write_read_req_report *report = buf;
  
  	if (read_length < 1 || read_length > 512 ||
  	    addr_length > sizeof(report->target_address))
  		return -EINVAL;
  
  	report->report = CP2112_DATA_WRITE_READ_REQUEST;
  	report->slave_address = slave_address << 1;
  	report->length = cpu_to_be16(read_length);
  	report->target_address_length = addr_length;
  	memcpy(report->target_address, addr, addr_length);
  	return addr_length + 5;
  }

  static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  			   int num)
  {
  	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
  	struct hid_device *hdev = dev->hdev;
  	u8 buf[64];
  	ssize_t count;

  	ssize_t read_length = 0;
  	u8 *read_buf = NULL;

  	unsigned int retries;
  	int ret;
  
  	hid_dbg(hdev, "I2C %d messages
  ", num);

  	if (num == 1) {
  		if (msgs->flags & I2C_M_RD) {
  			hid_dbg(hdev, "I2C read %#04x len %d
  ",
  				msgs->addr, msgs->len);
  			read_length = msgs->len;
  			read_buf = msgs->buf;
  			count = cp2112_read_req(buf, msgs->addr, msgs->len);
  		} else {
  			hid_dbg(hdev, "I2C write %#04x len %d
  ",
  				msgs->addr, msgs->len);
  			count = cp2112_i2c_write_req(buf, msgs->addr,
  						     msgs->buf, msgs->len);
  		}
  		if (count < 0)
  			return count;
  	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
  		   num == 2 &&
  		   msgs[0].addr == msgs[1].addr &&
  		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
  		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d
  ",
  			msgs[0].addr, msgs[0].len, msgs[1].len);
  		read_length = msgs[1].len;
  		read_buf = msgs[1].buf;
  		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
  				msgs[0].buf, msgs[0].len, msgs[1].len);
  		if (count < 0)
  			return count;
  	} else {

  		hid_err(hdev,
  			"Multi-message I2C transactions not supported
  ");
  		return -EOPNOTSUPP;
  	}

  	ret = hid_hw_power(hdev, PM_HINT_FULLON);
  	if (ret < 0) {
  		hid_err(hdev, "power management error: %d
  ", ret);
  		return ret;
  	}
  
  	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
  	if (ret < 0) {
  		hid_warn(hdev, "Error starting transaction: %d
  ", ret);
  		goto power_normal;
  	}
  
  	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
  		ret = cp2112_xfer_status(dev);
  		if (-EBUSY == ret)
  			continue;
  		if (ret < 0)
  			goto power_normal;
  		break;
  	}
  
  	if (XFER_STATUS_RETRIES <= retries) {
  		hid_warn(hdev, "Transfer timed out, cancelling.
  ");
  		buf[0] = CP2112_CANCEL_TRANSFER;
  		buf[1] = 0x01;
  
  		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
  		if (ret < 0)
  			hid_warn(hdev, "Error cancelling transaction: %d
  ",
  				 ret);
  
  		ret = -ETIMEDOUT;
  		goto power_normal;
  	}

  	for (count = 0; count < read_length;) {
  		ret = cp2112_read(dev, read_buf + count, read_length - count);

  		if (ret < 0)
  			goto power_normal;
  		if (ret == 0) {
  			hid_err(hdev, "read returned 0
  ");
  			ret = -EIO;
  			goto power_normal;
  		}
  		count += ret;

  		if (count > read_length) {

  			/*
  			 * The hardware returned too much data.
  			 * This is mostly harmless because cp2112_read()
  			 * has a limit check so didn't overrun our
  			 * buffer.  Nevertheless, we return an error
  			 * because something is seriously wrong and
  			 * it shouldn't go unnoticed.
  			 */
  			hid_err(hdev, "long read: %d > %zd
  ",

  				ret, read_length - count + ret);

  			ret = -EIO;
  			goto power_normal;
  		}

  	}

  	/* return the number of transferred messages */

  	ret = num;

  
  power_normal:
  	hid_hw_power(hdev, PM_HINT_NORMAL);
  	hid_dbg(hdev, "I2C transfer finished: %d
  ", ret);
  	return ret;
  }

  static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
  		       unsigned short flags, char read_write, u8 command,
  		       int size, union i2c_smbus_data *data)
  {
  	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
  	struct hid_device *hdev = dev->hdev;
  	u8 buf[64];

  	__le16 word;

  	ssize_t count;

  	size_t read_length = 0;
  	unsigned int retries;
  	int ret;
  
  	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d
  ",
  		read_write == I2C_SMBUS_WRITE ? "write" : "read",
  		addr, flags, command, size);
  
  	switch (size) {
  	case I2C_SMBUS_BYTE:
  		read_length = 1;
  
  		if (I2C_SMBUS_READ == read_write)
  			count = cp2112_read_req(buf, addr, read_length);
  		else

  			count = cp2112_write_req(buf, addr, command, NULL,

  						 0);
  		break;
  	case I2C_SMBUS_BYTE_DATA:
  		read_length = 1;
  
  		if (I2C_SMBUS_READ == read_write)
  			count = cp2112_write_read_req(buf, addr, read_length,
  						      command, NULL, 0);
  		else
  			count = cp2112_write_req(buf, addr, command,
  						 &data->byte, 1);
  		break;
  	case I2C_SMBUS_WORD_DATA:
  		read_length = 2;

  		word = cpu_to_le16(data->word);

  
  		if (I2C_SMBUS_READ == read_write)
  			count = cp2112_write_read_req(buf, addr, read_length,
  						      command, NULL, 0);
  		else
  			count = cp2112_write_req(buf, addr, command,
  						 (u8 *)&word, 2);
  		break;
  	case I2C_SMBUS_PROC_CALL:
  		size = I2C_SMBUS_WORD_DATA;
  		read_write = I2C_SMBUS_READ;
  		read_length = 2;

  		word = cpu_to_le16(data->word);

  
  		count = cp2112_write_read_req(buf, addr, read_length, command,
  					      (u8 *)&word, 2);
  		break;
  	case I2C_SMBUS_I2C_BLOCK_DATA:

  		if (read_write == I2C_SMBUS_READ) {
  			read_length = data->block[0];
  			count = cp2112_write_read_req(buf, addr, read_length,
  						      command, NULL, 0);
  		} else {
  			count = cp2112_write_req(buf, addr, command,
  						 data->block + 1,
  						 data->block[0]);
  		}
  		break;

  	case I2C_SMBUS_BLOCK_DATA:
  		if (I2C_SMBUS_READ == read_write) {
  			count = cp2112_write_read_req(buf, addr,
  						      I2C_SMBUS_BLOCK_MAX,
  						      command, NULL, 0);
  		} else {
  			count = cp2112_write_req(buf, addr, command,
  						 data->block,
  						 data->block[0] + 1);
  		}
  		break;
  	case I2C_SMBUS_BLOCK_PROC_CALL:
  		size = I2C_SMBUS_BLOCK_DATA;
  		read_write = I2C_SMBUS_READ;
  
  		count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
  					      command, data->block,
  					      data->block[0] + 1);
  		break;
  	default:
  		hid_warn(hdev, "Unsupported transaction %d
  ", size);
  		return -EOPNOTSUPP;
  	}
  
  	if (count < 0)
  		return count;
  
  	ret = hid_hw_power(hdev, PM_HINT_FULLON);
  	if (ret < 0) {
  		hid_err(hdev, "power management error: %d
  ", ret);
  		return ret;
  	}
  
  	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
  	if (ret < 0) {
  		hid_warn(hdev, "Error starting transaction: %d
  ", ret);
  		goto power_normal;
  	}
  
  	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
  		ret = cp2112_xfer_status(dev);
  		if (-EBUSY == ret)
  			continue;
  		if (ret < 0)
  			goto power_normal;
  		break;
  	}
  
  	if (XFER_STATUS_RETRIES <= retries) {
  		hid_warn(hdev, "Transfer timed out, cancelling.
  ");
  		buf[0] = CP2112_CANCEL_TRANSFER;
  		buf[1] = 0x01;
  
  		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
  		if (ret < 0)
  			hid_warn(hdev, "Error cancelling transaction: %d
  ",
  				 ret);
  
  		ret = -ETIMEDOUT;
  		goto power_normal;
  	}
  
  	if (I2C_SMBUS_WRITE == read_write) {
  		ret = 0;
  		goto power_normal;
  	}
  
  	if (I2C_SMBUS_BLOCK_DATA == size)
  		read_length = ret;
  
  	ret = cp2112_read(dev, buf, read_length);
  	if (ret < 0)
  		goto power_normal;
  	if (ret != read_length) {

  		hid_warn(hdev, "short read: %d < %zd
  ", ret, read_length);

  		ret = -EIO;
  		goto power_normal;
  	}
  
  	switch (size) {
  	case I2C_SMBUS_BYTE:
  	case I2C_SMBUS_BYTE_DATA:
  		data->byte = buf[0];
  		break;
  	case I2C_SMBUS_WORD_DATA:

  		data->word = le16_to_cpup((__le16 *)buf);

  		break;

  	case I2C_SMBUS_I2C_BLOCK_DATA:
  		memcpy(data->block + 1, buf, read_length);
  		break;

  	case I2C_SMBUS_BLOCK_DATA:
  		if (read_length > I2C_SMBUS_BLOCK_MAX) {
  			ret = -EPROTO;
  			goto power_normal;
  		}
  
  		memcpy(data->block, buf, read_length);
  		break;
  	}
  
  	ret = 0;
  power_normal:
  	hid_hw_power(hdev, PM_HINT_NORMAL);
  	hid_dbg(hdev, "transfer finished: %d
  ", ret);
  	return ret;
  }
  
  static u32 cp2112_functionality(struct i2c_adapter *adap)
  {

  	return I2C_FUNC_I2C |
  		I2C_FUNC_SMBUS_BYTE |

  		I2C_FUNC_SMBUS_BYTE_DATA |
  		I2C_FUNC_SMBUS_WORD_DATA |
  		I2C_FUNC_SMBUS_BLOCK_DATA |
  		I2C_FUNC_SMBUS_I2C_BLOCK |
  		I2C_FUNC_SMBUS_PROC_CALL |
  		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
  }
  
  static const struct i2c_algorithm smbus_algorithm = {

  	.master_xfer	= cp2112_i2c_xfer,

  	.smbus_xfer	= cp2112_xfer,
  	.functionality	= cp2112_functionality,
  };
  
  static int cp2112_get_usb_config(struct hid_device *hdev,
  				 struct cp2112_usb_config_report *cfg)
  {
  	int ret;
  
  	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
  			     HID_FEATURE_REPORT);
  	if (ret != sizeof(*cfg)) {
  		hid_err(hdev, "error reading usb config: %d
  ", ret);
  		if (ret < 0)
  			return ret;
  		return -EIO;
  	}
  
  	return 0;
  }
  
  static int cp2112_set_usb_config(struct hid_device *hdev,
  				 struct cp2112_usb_config_report *cfg)
  {
  	int ret;
  
  	BUG_ON(cfg->report != CP2112_USB_CONFIG);
  
  	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
  				HID_FEATURE_REPORT);
  	if (ret != sizeof(*cfg)) {
  		hid_err(hdev, "error writing usb config: %d
  ", ret);
  		if (ret < 0)
  			return ret;
  		return -EIO;
  	}
  
  	return 0;
  }
  
  static void chmod_sysfs_attrs(struct hid_device *hdev);
  
  #define CP2112_CONFIG_ATTR(name, store, format, ...) \
  static ssize_t name##_store(struct device *kdev, \
  			    struct device_attribute *attr, const char *buf, \
  			    size_t count) \
  { \

  	struct hid_device *hdev = to_hid_device(kdev); \

  	struct cp2112_usb_config_report cfg; \
  	int ret = cp2112_get_usb_config(hdev, &cfg); \
  	if (ret) \
  		return ret; \
  	store; \
  	ret = cp2112_set_usb_config(hdev, &cfg); \
  	if (ret) \
  		return ret; \
  	chmod_sysfs_attrs(hdev); \
  	return count; \
  } \
  static ssize_t name##_show(struct device *kdev, \
  			   struct device_attribute *attr, char *buf) \
  { \

  	struct hid_device *hdev = to_hid_device(kdev); \

  	struct cp2112_usb_config_report cfg; \
  	int ret = cp2112_get_usb_config(hdev, &cfg); \
  	if (ret) \
  		return ret; \
  	return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
  } \

  static DEVICE_ATTR_RW(name);

  
  CP2112_CONFIG_ATTR(vendor_id, ({
  	u16 vid;
  
  	if (sscanf(buf, "%hi", &vid) != 1)
  		return -EINVAL;
  
  	cfg.vid = cpu_to_le16(vid);
  	cfg.mask = 0x01;
  }), "0x%04x
  ", le16_to_cpu(cfg.vid));
  
  CP2112_CONFIG_ATTR(product_id, ({
  	u16 pid;
  
  	if (sscanf(buf, "%hi", &pid) != 1)
  		return -EINVAL;
  
  	cfg.pid = cpu_to_le16(pid);
  	cfg.mask = 0x02;
  }), "0x%04x
  ", le16_to_cpu(cfg.pid));
  
  CP2112_CONFIG_ATTR(max_power, ({
  	int mA;
  
  	if (sscanf(buf, "%i", &mA) != 1)
  		return -EINVAL;
  
  	cfg.max_power = (mA + 1) / 2;
  	cfg.mask = 0x04;
  }), "%u mA
  ", cfg.max_power * 2);
  
  CP2112_CONFIG_ATTR(power_mode, ({
  	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
  		return -EINVAL;
  
  	cfg.mask = 0x08;
  }), "%u
  ", cfg.power_mode);
  
  CP2112_CONFIG_ATTR(release_version, ({
  	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
  	    != 2)
  		return -EINVAL;
  
  	cfg.mask = 0x10;
  }), "%u.%u
  ", cfg.release_major, cfg.release_minor);
  
  #undef CP2112_CONFIG_ATTR
  
  struct cp2112_pstring_attribute {
  	struct device_attribute attr;
  	unsigned char report;
  };
  
  static ssize_t pstr_store(struct device *kdev,
  			  struct device_attribute *kattr, const char *buf,
  			  size_t count)
  {

  	struct hid_device *hdev = to_hid_device(kdev);

  	struct cp2112_pstring_attribute *attr =
  		container_of(kattr, struct cp2112_pstring_attribute, attr);
  	struct cp2112_string_report report;
  	int ret;
  
  	memset(&report, 0, sizeof(report));
  
  	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
  			      report.string, ARRAY_SIZE(report.string));
  	report.report = attr->report;
  	report.length = ret * sizeof(report.string[0]) + 2;
  	report.type = USB_DT_STRING;
  
  	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
  				HID_FEATURE_REPORT);
  	if (ret != report.length + 1) {
  		hid_err(hdev, "error writing %s string: %d
  ", kattr->attr.name,
  			ret);
  		if (ret < 0)
  			return ret;
  		return -EIO;
  	}
  
  	chmod_sysfs_attrs(hdev);
  	return count;
  }
  
  static ssize_t pstr_show(struct device *kdev,
  			 struct device_attribute *kattr, char *buf)
  {

  	struct hid_device *hdev = to_hid_device(kdev);

  	struct cp2112_pstring_attribute *attr =
  		container_of(kattr, struct cp2112_pstring_attribute, attr);
  	struct cp2112_string_report report;
  	u8 length;
  	int ret;
  
  	ret = cp2112_hid_get(hdev, attr->report, &report.report,
  			     sizeof(report) - 1, HID_FEATURE_REPORT);
  	if (ret < 3) {
  		hid_err(hdev, "error reading %s string: %d
  ", kattr->attr.name,
  			ret);
  		if (ret < 0)
  			return ret;
  		return -EIO;
  	}
  
  	if (report.length < 2) {
  		hid_err(hdev, "invalid %s string length: %d
  ",
  			kattr->attr.name, report.length);
  		return -EIO;
  	}
  
  	length = report.length > ret - 1 ? ret - 1 : report.length;
  	length = (length - 2) / sizeof(report.string[0]);
  	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
  			      PAGE_SIZE - 1);
  	buf[ret++] = '
  ';
  	return ret;
  }
  
  #define CP2112_PSTR_ATTR(name, _report) \

  static struct cp2112_pstring_attribute dev_attr_##name = { \

  	.attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
  	.report = _report, \
  };
  
  CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
  CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
  CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
  
  #undef CP2112_PSTR_ATTR
  
  static const struct attribute_group cp2112_attr_group = {
  	.attrs = (struct attribute *[]){
  		&dev_attr_vendor_id.attr,
  		&dev_attr_product_id.attr,
  		&dev_attr_max_power.attr,
  		&dev_attr_power_mode.attr,
  		&dev_attr_release_version.attr,
  		&dev_attr_manufacturer.attr.attr,
  		&dev_attr_product.attr.attr,
  		&dev_attr_serial.attr.attr,
  		NULL
  	}
  };
  
  /* Chmoding our sysfs attributes is simply a way to expose which fields in the
   * PROM have already been programmed. We do not depend on this preventing
   * writing to these attributes since the CP2112 will simply ignore writes to
   * already-programmed fields. This is why there is no sense in fixing this
   * racy behaviour.
   */
  static void chmod_sysfs_attrs(struct hid_device *hdev)
  {
  	struct attribute **attr;
  	u8 buf[2];
  	int ret;
  
  	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
  			     HID_FEATURE_REPORT);
  	if (ret != sizeof(buf)) {
  		hid_err(hdev, "error reading lock byte: %d
  ", ret);
  		return;
  	}
  
  	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
  		umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
  		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
  		if (ret < 0)
  			hid_err(hdev, "error chmoding sysfs file %s
  ",
  				(*attr)->name);
  		buf[1] >>= 1;
  	}
  }

  static void cp2112_gpio_irq_ack(struct irq_data *d)
  {
  }
  
  static void cp2112_gpio_irq_mask(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  	struct cp2112_device *dev = gpiochip_get_data(gc);
  
  	__clear_bit(d->hwirq, &dev->irq_mask);
  }
  
  static void cp2112_gpio_irq_unmask(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  	struct cp2112_device *dev = gpiochip_get_data(gc);
  
  	__set_bit(d->hwirq, &dev->irq_mask);
  }
  
  static void cp2112_gpio_poll_callback(struct work_struct *work)
  {
  	struct cp2112_device *dev = container_of(work, struct cp2112_device,
  						 gpio_poll_worker.work);
  	struct irq_data *d;
  	u8 gpio_mask;
  	u8 virqs = (u8)dev->irq_mask;
  	u32 irq_type;
  	int irq, virq, ret;
  
  	ret = cp2112_gpio_get_all(&dev->gc);
  	if (ret == -ENODEV) /* the hardware has been disconnected */
  		return;
  	if (ret < 0)
  		goto exit;
  
  	gpio_mask = ret;
  
  	while (virqs) {
  		virq = ffs(virqs) - 1;
  		virqs &= ~BIT(virq);
  
  		if (!dev->gc.to_irq)
  			break;
  
  		irq = dev->gc.to_irq(&dev->gc, virq);
  
  		d = irq_get_irq_data(irq);
  		if (!d)
  			continue;
  
  		irq_type = irqd_get_trigger_type(d);
  
  		if (gpio_mask & BIT(virq)) {
  			/* Level High */
  
  			if (irq_type & IRQ_TYPE_LEVEL_HIGH)
  				handle_nested_irq(irq);
  
  			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
  			    !(dev->gpio_prev_state & BIT(virq)))
  				handle_nested_irq(irq);
  		} else {
  			/* Level Low */
  
  			if (irq_type & IRQ_TYPE_LEVEL_LOW)
  				handle_nested_irq(irq);
  
  			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
  			    (dev->gpio_prev_state & BIT(virq)))
  				handle_nested_irq(irq);
  		}
  	}
  
  	dev->gpio_prev_state = gpio_mask;
  
  exit:
  	if (dev->gpio_poll)
  		schedule_delayed_work(&dev->gpio_poll_worker, 10);
  }
  
  
  static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  	struct cp2112_device *dev = gpiochip_get_data(gc);
  
  	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
  
  	cp2112_gpio_direction_input(gc, d->hwirq);
  
  	if (!dev->gpio_poll) {
  		dev->gpio_poll = true;
  		schedule_delayed_work(&dev->gpio_poll_worker, 0);
  	}
  
  	cp2112_gpio_irq_unmask(d);
  	return 0;
  }
  
  static void cp2112_gpio_irq_shutdown(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  	struct cp2112_device *dev = gpiochip_get_data(gc);
  
  	cancel_delayed_work_sync(&dev->gpio_poll_worker);
  }
  
  static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
  {
  	return 0;
  }
  
  static struct irq_chip cp2112_gpio_irqchip = {
  	.name = "cp2112-gpio",
  	.irq_startup = cp2112_gpio_irq_startup,
  	.irq_shutdown = cp2112_gpio_irq_shutdown,
  	.irq_ack = cp2112_gpio_irq_ack,
  	.irq_mask = cp2112_gpio_irq_mask,
  	.irq_unmask = cp2112_gpio_irq_unmask,
  	.irq_set_type = cp2112_gpio_irq_type,
  };
  
  static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
  					      int pin)
  {
  	int ret;
  
  	if (dev->desc[pin])
  		return -EINVAL;
  
  	dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
  						   "HID/I2C:Event");
  	if (IS_ERR(dev->desc[pin])) {
  		dev_err(dev->gc.parent, "Failed to request GPIO
  ");
  		return PTR_ERR(dev->desc[pin]);
  	}
  
  	ret = gpiochip_lock_as_irq(&dev->gc, pin);
  	if (ret) {
  		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt
  ");
  		goto err_desc;
  	}
  
  	ret = gpiod_to_irq(dev->desc[pin]);
  	if (ret < 0) {
  		dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ
  ");
  		goto err_lock;
  	}
  
  	return ret;
  
  err_lock:
  	gpiochip_unlock_as_irq(&dev->gc, pin);
  err_desc:
  	gpiochip_free_own_desc(dev->desc[pin]);
  	dev->desc[pin] = NULL;
  	return ret;
  }

  static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
  {
  	struct cp2112_device *dev;
  	u8 buf[3];
  	struct cp2112_smbus_config_report config;
  	int ret;

  	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
  	if (!dev)
  		return -ENOMEM;
  
  	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
  					  GFP_KERNEL);
  	if (!dev->in_out_buffer)
  		return -ENOMEM;

  	mutex_init(&dev->lock);

  	ret = hid_parse(hdev);
  	if (ret) {
  		hid_err(hdev, "parse failed
  ");
  		return ret;
  	}
  
  	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
  	if (ret) {
  		hid_err(hdev, "hw start failed
  ");
  		return ret;
  	}
  
  	ret = hid_hw_open(hdev);
  	if (ret) {
  		hid_err(hdev, "hw open failed
  ");
  		goto err_hid_stop;
  	}
  
  	ret = hid_hw_power(hdev, PM_HINT_FULLON);
  	if (ret < 0) {
  		hid_err(hdev, "power management error: %d
  ", ret);
  		goto err_hid_close;
  	}
  
  	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
  			     HID_FEATURE_REPORT);
  	if (ret != sizeof(buf)) {
  		hid_err(hdev, "error requesting version
  ");
  		if (ret >= 0)
  			ret = -EIO;
  		goto err_power_normal;
  	}
  
  	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X
  ",
  		 buf[1], buf[2]);
  
  	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
  			     sizeof(config), HID_FEATURE_REPORT);
  	if (ret != sizeof(config)) {
  		hid_err(hdev, "error requesting SMBus config
  ");
  		if (ret >= 0)
  			ret = -EIO;
  		goto err_power_normal;
  	}
  
  	config.retry_time = cpu_to_be16(1);
  
  	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
  				HID_FEATURE_REPORT);
  	if (ret != sizeof(config)) {
  		hid_err(hdev, "error setting SMBus config
  ");
  		if (ret >= 0)
  			ret = -EIO;
  		goto err_power_normal;
  	}

  	hid_set_drvdata(hdev, (void *)dev);
  	dev->hdev		= hdev;
  	dev->adap.owner		= THIS_MODULE;
  	dev->adap.class		= I2C_CLASS_HWMON;
  	dev->adap.algo		= &smbus_algorithm;
  	dev->adap.algo_data	= dev;
  	dev->adap.dev.parent	= &hdev->dev;
  	snprintf(dev->adap.name, sizeof(dev->adap.name),

  		 "CP2112 SMBus Bridge on hidraw%d",
  		 ((struct hidraw *)hdev->hidraw)->minor);

  	dev->hwversion = buf[2];

  	init_waitqueue_head(&dev->wait);
  
  	hid_device_io_start(hdev);
  	ret = i2c_add_adapter(&dev->adap);
  	hid_device_io_stop(hdev);
  
  	if (ret) {
  		hid_err(hdev, "error registering i2c adapter
  ");

  		goto err_power_normal;

  	}
  
  	hid_dbg(hdev, "adapter registered
  ");
  
  	dev->gc.label			= "cp2112_gpio";
  	dev->gc.direction_input		= cp2112_gpio_direction_input;
  	dev->gc.direction_output	= cp2112_gpio_direction_output;
  	dev->gc.set			= cp2112_gpio_set;
  	dev->gc.get			= cp2112_gpio_get;
  	dev->gc.base			= -1;
  	dev->gc.ngpio			= 8;
  	dev->gc.can_sleep		= 1;

  	dev->gc.parent			= &hdev->dev;

  	ret = gpiochip_add_data(&dev->gc, dev);

  	if (ret < 0) {
  		hid_err(hdev, "error registering gpio chip
  ");
  		goto err_free_i2c;
  	}
  
  	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
  	if (ret < 0) {
  		hid_err(hdev, "error creating sysfs attrs
  ");
  		goto err_gpiochip_remove;
  	}
  
  	chmod_sysfs_attrs(hdev);
  	hid_hw_power(hdev, PM_HINT_NORMAL);

  	ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
  				   handle_simple_irq, IRQ_TYPE_NONE);
  	if (ret) {
  		dev_err(dev->gc.parent, "failed to add IRQ chip
  ");
  		goto err_sysfs_remove;
  	}

  	return ret;

  err_sysfs_remove:
  	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);

  err_gpiochip_remove:

  	gpiochip_remove(&dev->gc);

  err_free_i2c:
  	i2c_del_adapter(&dev->adap);

  err_power_normal:
  	hid_hw_power(hdev, PM_HINT_NORMAL);
  err_hid_close:
  	hid_hw_close(hdev);
  err_hid_stop:
  	hid_hw_stop(hdev);
  	return ret;
  }
  
  static void cp2112_remove(struct hid_device *hdev)
  {
  	struct cp2112_device *dev = hid_get_drvdata(hdev);

  	int i;

  
  	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);

  	i2c_del_adapter(&dev->adap);

  
  	if (dev->gpio_poll) {
  		dev->gpio_poll = false;
  		cancel_delayed_work_sync(&dev->gpio_poll_worker);
  	}
  
  	for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
  		gpiochip_unlock_as_irq(&dev->gc, i);
  		gpiochip_free_own_desc(dev->desc[i]);
  	}
  
  	gpiochip_remove(&dev->gc);

  	/* i2c_del_adapter has finished removing all i2c devices from our
  	 * adapter. Well behaved devices should no longer call our cp2112_xfer
  	 * and should have waited for any pending calls to finish. It has also
  	 * waited for device_unregister(&adap->dev) to complete. Therefore we
  	 * can safely free our struct cp2112_device.
  	 */
  	hid_hw_close(hdev);
  	hid_hw_stop(hdev);

  }
  
  static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
  			    u8 *data, int size)
  {
  	struct cp2112_device *dev = hid_get_drvdata(hdev);
  	struct cp2112_xfer_status_report *xfer = (void *)data;
  
  	switch (data[0]) {
  	case CP2112_TRANSFER_STATUS_RESPONSE:
  		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x
  ",
  			xfer->status0, xfer->status1,
  			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
  
  		switch (xfer->status0) {
  		case STATUS0_IDLE:
  			dev->xfer_status = -EAGAIN;
  			break;
  		case STATUS0_BUSY:
  			dev->xfer_status = -EBUSY;
  			break;
  		case STATUS0_COMPLETE:
  			dev->xfer_status = be16_to_cpu(xfer->length);
  			break;
  		case STATUS0_ERROR:
  			switch (xfer->status1) {
  			case STATUS1_TIMEOUT_NACK:
  			case STATUS1_TIMEOUT_BUS:
  				dev->xfer_status = -ETIMEDOUT;
  				break;
  			default:
  				dev->xfer_status = -EIO;
  				break;
  			}
  			break;
  		default:
  			dev->xfer_status = -EINVAL;
  			break;
  		}
  
  		atomic_set(&dev->xfer_avail, 1);
  		break;
  	case CP2112_DATA_READ_RESPONSE:
  		hid_dbg(hdev, "read response: %02x %02x
  ", data[1], data[2]);
  
  		dev->read_length = data[2];
  		if (dev->read_length > sizeof(dev->read_data))
  			dev->read_length = sizeof(dev->read_data);
  
  		memcpy(dev->read_data, &data[3], dev->read_length);
  		atomic_set(&dev->read_avail, 1);
  		break;
  	default:
  		hid_err(hdev, "unknown report
  ");
  
  		return 0;
  	}
  
  	wake_up_interruptible(&dev->wait);
  	return 1;
  }
  
  static struct hid_driver cp2112_driver = {
  	.name		= "cp2112",
  	.id_table	= cp2112_devices,
  	.probe		= cp2112_probe,
  	.remove		= cp2112_remove,
  	.raw_event	= cp2112_raw_event,
  };
  
  module_hid_driver(cp2112_driver);
  MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
  MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
  MODULE_LICENSE("GPL");