/*
   *  HID driver for Logitech Unifying receivers
   *
   *  Copyright (c) 2011 Logitech
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
  
   *
   * This program is distributed in the hope that 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   */
  
  
  #include <linux/device.h>
  #include <linux/hid.h>
  #include <linux/module.h>
  #include <linux/usb.h>

  #include <linux/kfifo.h>

  #include <asm/unaligned.h>

  #include "hid-ids.h"

  
  #define DJ_MAX_PAIRED_DEVICES			6
  #define DJ_MAX_NUMBER_NOTIFICATIONS		8
  #define DJ_RECEIVER_INDEX			0
  #define DJ_DEVICE_INDEX_MIN			1
  #define DJ_DEVICE_INDEX_MAX			6
  
  #define DJREPORT_SHORT_LENGTH			15
  #define DJREPORT_LONG_LENGTH			32
  
  #define REPORT_ID_DJ_SHORT			0x20
  #define REPORT_ID_DJ_LONG			0x21

  #define REPORT_ID_HIDPP_SHORT			0x10
  #define REPORT_ID_HIDPP_LONG			0x11
  
  #define HIDPP_REPORT_SHORT_LENGTH		7
  #define HIDPP_REPORT_LONG_LENGTH		20
  
  #define HIDPP_RECEIVER_INDEX			0xff
  
  #define REPORT_TYPE_RFREPORT_FIRST		0x01

  #define REPORT_TYPE_RFREPORT_LAST		0x1F
  
  /* Command Switch to DJ mode */
  #define REPORT_TYPE_CMD_SWITCH			0x80
  #define CMD_SWITCH_PARAM_DEVBITFIELD		0x00
  #define CMD_SWITCH_PARAM_TIMEOUT_SECONDS	0x01
  #define TIMEOUT_NO_KEEPALIVE			0x00
  
  /* Command to Get the list of Paired devices */
  #define REPORT_TYPE_CMD_GET_PAIRED_DEVICES	0x81
  
  /* Device Paired Notification */
  #define REPORT_TYPE_NOTIF_DEVICE_PAIRED		0x41
  #define SPFUNCTION_MORE_NOTIF_EXPECTED		0x01
  #define SPFUNCTION_DEVICE_LIST_EMPTY		0x02
  #define DEVICE_PAIRED_PARAM_SPFUNCTION		0x00
  #define DEVICE_PAIRED_PARAM_EQUAD_ID_LSB	0x01
  #define DEVICE_PAIRED_PARAM_EQUAD_ID_MSB	0x02
  #define DEVICE_PAIRED_RF_REPORT_TYPE		0x03
  
  /* Device Un-Paired Notification */
  #define REPORT_TYPE_NOTIF_DEVICE_UNPAIRED	0x40
  
  
  /* Connection Status Notification */
  #define REPORT_TYPE_NOTIF_CONNECTION_STATUS	0x42
  #define CONNECTION_STATUS_PARAM_STATUS		0x00
  #define STATUS_LINKLOSS				0x01
  
  /* Error Notification */
  #define REPORT_TYPE_NOTIF_ERROR			0x7F
  #define NOTIF_ERROR_PARAM_ETYPE			0x00
  #define ETYPE_KEEPALIVE_TIMEOUT			0x01
  
  /* supported DJ HID && RF report types */
  #define REPORT_TYPE_KEYBOARD			0x01
  #define REPORT_TYPE_MOUSE			0x02
  #define REPORT_TYPE_CONSUMER_CONTROL		0x03
  #define REPORT_TYPE_SYSTEM_CONTROL		0x04
  #define REPORT_TYPE_MEDIA_CENTER		0x08
  #define REPORT_TYPE_LEDS			0x0E
  
  /* RF Report types bitfield */
  #define STD_KEYBOARD				0x00000002
  #define STD_MOUSE				0x00000004
  #define MULTIMEDIA				0x00000008
  #define POWER_KEYS				0x00000010
  #define MEDIA_CENTER				0x00000100
  #define KBD_LEDS				0x00004000
  
  struct dj_report {
  	u8 report_id;
  	u8 device_index;
  	u8 report_type;
  	u8 report_params[DJREPORT_SHORT_LENGTH - 3];
  };
  
  struct dj_receiver_dev {
  	struct hid_device *hdev;
  	struct dj_device *paired_dj_devices[DJ_MAX_PAIRED_DEVICES +
  					    DJ_DEVICE_INDEX_MIN];
  	struct work_struct work;
  	struct kfifo notif_fifo;
  	spinlock_t lock;
  	bool querying_devices;
  };
  
  struct dj_device {
  	struct hid_device *hdev;
  	struct dj_receiver_dev *dj_receiver_dev;
  	u32 reports_supported;
  	u8 device_index;
  };

  
  /* Keyboard descriptor (1) */
  static const char kbd_descriptor[] = {
  	0x05, 0x01,		/* USAGE_PAGE (generic Desktop)     */
  	0x09, 0x06,		/* USAGE (Keyboard)         */
  	0xA1, 0x01,		/* COLLECTION (Application)     */
  	0x85, 0x01,		/* REPORT_ID (1)            */
  	0x95, 0x08,		/*   REPORT_COUNT (8)           */
  	0x75, 0x01,		/*   REPORT_SIZE (1)            */
  	0x15, 0x00,		/*   LOGICAL_MINIMUM (0)        */
  	0x25, 0x01,		/*   LOGICAL_MAXIMUM (1)        */
  	0x05, 0x07,		/*   USAGE_PAGE (Keyboard)      */
  	0x19, 0xE0,		/*   USAGE_MINIMUM (Left Control)   */
  	0x29, 0xE7,		/*   USAGE_MAXIMUM (Right GUI)      */
  	0x81, 0x02,		/*   INPUT (Data,Var,Abs)       */

  	0x95, 0x06,		/*   REPORT_COUNT (6)           */
  	0x75, 0x08,		/*   REPORT_SIZE (8)            */
  	0x15, 0x00,		/*   LOGICAL_MINIMUM (0)        */
  	0x26, 0xFF, 0x00,	/*   LOGICAL_MAXIMUM (255)      */
  	0x05, 0x07,		/*   USAGE_PAGE (Keyboard)      */
  	0x19, 0x00,		/*   USAGE_MINIMUM (no event)       */
  	0x2A, 0xFF, 0x00,	/*   USAGE_MAXIMUM (reserved)       */
  	0x81, 0x00,		/*   INPUT (Data,Ary,Abs)       */

  	0x85, 0x0e,		/* REPORT_ID (14)               */
  	0x05, 0x08,		/*   USAGE PAGE (LED page)      */
  	0x95, 0x05,		/*   REPORT COUNT (5)           */
  	0x75, 0x01,		/*   REPORT SIZE (1)            */
  	0x15, 0x00,		/*   LOGICAL_MINIMUM (0)        */
  	0x25, 0x01,		/*   LOGICAL_MAXIMUM (1)        */
  	0x19, 0x01,		/*   USAGE MINIMUM (1)          */
  	0x29, 0x05,		/*   USAGE MAXIMUM (5)          */
  	0x91, 0x02,		/*   OUTPUT (Data, Variable, Absolute)  */
  	0x95, 0x01,		/*   REPORT COUNT (1)           */
  	0x75, 0x03,		/*   REPORT SIZE (3)            */
  	0x91, 0x01,		/*   OUTPUT (Constant)          */

  	0xC0
  };
  
  /* Mouse descriptor (2)     */
  static const char mse_descriptor[] = {
  	0x05, 0x01,		/*  USAGE_PAGE (Generic Desktop)        */
  	0x09, 0x02,		/*  USAGE (Mouse)                       */
  	0xA1, 0x01,		/*  COLLECTION (Application)            */
  	0x85, 0x02,		/*    REPORT_ID = 2                     */
  	0x09, 0x01,		/*    USAGE (pointer)                   */
  	0xA1, 0x00,		/*    COLLECTION (physical)             */
  	0x05, 0x09,		/*      USAGE_PAGE (buttons)            */
  	0x19, 0x01,		/*      USAGE_MIN (1)                   */
  	0x29, 0x10,		/*      USAGE_MAX (16)                  */
  	0x15, 0x00,		/*      LOGICAL_MIN (0)                 */
  	0x25, 0x01,		/*      LOGICAL_MAX (1)                 */
  	0x95, 0x10,		/*      REPORT_COUNT (16)               */
  	0x75, 0x01,		/*      REPORT_SIZE (1)                 */
  	0x81, 0x02,		/*      INPUT (data var abs)            */
  	0x05, 0x01,		/*      USAGE_PAGE (generic desktop)    */
  	0x16, 0x01, 0xF8,	/*      LOGICAL_MIN (-2047)             */
  	0x26, 0xFF, 0x07,	/*      LOGICAL_MAX (2047)              */
  	0x75, 0x0C,		/*      REPORT_SIZE (12)                */
  	0x95, 0x02,		/*      REPORT_COUNT (2)                */
  	0x09, 0x30,		/*      USAGE (X)                       */
  	0x09, 0x31,		/*      USAGE (Y)                       */
  	0x81, 0x06,		/*      INPUT                           */
  	0x15, 0x81,		/*      LOGICAL_MIN (-127)              */
  	0x25, 0x7F,		/*      LOGICAL_MAX (127)               */
  	0x75, 0x08,		/*      REPORT_SIZE (8)                 */
  	0x95, 0x01,		/*      REPORT_COUNT (1)                */
  	0x09, 0x38,		/*      USAGE (wheel)                   */
  	0x81, 0x06,		/*      INPUT                           */
  	0x05, 0x0C,		/*      USAGE_PAGE(consumer)            */
  	0x0A, 0x38, 0x02,	/*      USAGE(AC Pan)                   */
  	0x95, 0x01,		/*      REPORT_COUNT (1)                */
  	0x81, 0x06,		/*      INPUT                           */
  	0xC0,			/*    END_COLLECTION                    */
  	0xC0,			/*  END_COLLECTION                      */
  };
  
  /* Consumer Control descriptor (3) */
  static const char consumer_descriptor[] = {
  	0x05, 0x0C,		/* USAGE_PAGE (Consumer Devices)       */
  	0x09, 0x01,		/* USAGE (Consumer Control)            */
  	0xA1, 0x01,		/* COLLECTION (Application)            */
  	0x85, 0x03,		/* REPORT_ID = 3                       */
  	0x75, 0x10,		/* REPORT_SIZE (16)                    */
  	0x95, 0x02,		/* REPORT_COUNT (2)                    */
  	0x15, 0x01,		/* LOGICAL_MIN (1)                     */
  	0x26, 0x8C, 0x02,	/* LOGICAL_MAX (652)                   */
  	0x19, 0x01,		/* USAGE_MIN (1)                       */
  	0x2A, 0x8C, 0x02,	/* USAGE_MAX (652)                     */
  	0x81, 0x00,		/* INPUT (Data Ary Abs)                */
  	0xC0,			/* END_COLLECTION                      */
  };				/*                                     */
  
  /* System control descriptor (4) */
  static const char syscontrol_descriptor[] = {
  	0x05, 0x01,		/*   USAGE_PAGE (Generic Desktop)      */
  	0x09, 0x80,		/*   USAGE (System Control)            */
  	0xA1, 0x01,		/*   COLLECTION (Application)          */
  	0x85, 0x04,		/*   REPORT_ID = 4                     */
  	0x75, 0x02,		/*   REPORT_SIZE (2)                   */
  	0x95, 0x01,		/*   REPORT_COUNT (1)                  */
  	0x15, 0x01,		/*   LOGICAL_MIN (1)                   */
  	0x25, 0x03,		/*   LOGICAL_MAX (3)                   */
  	0x09, 0x82,		/*   USAGE (System Sleep)              */
  	0x09, 0x81,		/*   USAGE (System Power Down)         */
  	0x09, 0x83,		/*   USAGE (System Wake Up)            */
  	0x81, 0x60,		/*   INPUT (Data Ary Abs NPrf Null)    */
  	0x75, 0x06,		/*   REPORT_SIZE (6)                   */
  	0x81, 0x03,		/*   INPUT (Cnst Var Abs)              */
  	0xC0,			/*   END_COLLECTION                    */
  };
  
  /* Media descriptor (8) */
  static const char media_descriptor[] = {
  	0x06, 0xbc, 0xff,	/* Usage Page 0xffbc                   */
  	0x09, 0x88,		/* Usage 0x0088                        */
  	0xa1, 0x01,		/* BeginCollection                     */
  	0x85, 0x08,		/*   Report ID 8                       */
  	0x19, 0x01,		/*   Usage Min 0x0001                  */
  	0x29, 0xff,		/*   Usage Max 0x00ff                  */
  	0x15, 0x01,		/*   Logical Min 1                     */
  	0x26, 0xff, 0x00,	/*   Logical Max 255                   */
  	0x75, 0x08,		/*   Report Size 8                     */
  	0x95, 0x01,		/*   Report Count 1                    */
  	0x81, 0x00,		/*   Input                             */
  	0xc0,			/* EndCollection                       */
  };				/*                                     */

  /* HIDPP descriptor */
  static const char hidpp_descriptor[] = {
  	0x06, 0x00, 0xff,	/* Usage Page (Vendor Defined Page 1)  */
  	0x09, 0x01,		/* Usage (Vendor Usage 1)              */
  	0xa1, 0x01,		/* Collection (Application)            */
  	0x85, 0x10,		/*   Report ID (16)                    */
  	0x75, 0x08,		/*   Report Size (8)                   */
  	0x95, 0x06,		/*   Report Count (6)                  */
  	0x15, 0x00,		/*   Logical Minimum (0)               */
  	0x26, 0xff, 0x00,	/*   Logical Maximum (255)             */
  	0x09, 0x01,		/*   Usage (Vendor Usage 1)            */
  	0x81, 0x00,		/*   Input (Data,Arr,Abs)              */
  	0x09, 0x01,		/*   Usage (Vendor Usage 1)            */
  	0x91, 0x00,		/*   Output (Data,Arr,Abs)             */
  	0xc0,			/* End Collection                      */
  	0x06, 0x00, 0xff,	/* Usage Page (Vendor Defined Page 1)  */
  	0x09, 0x02,		/* Usage (Vendor Usage 2)              */
  	0xa1, 0x01,		/* Collection (Application)            */
  	0x85, 0x11,		/*   Report ID (17)                    */
  	0x75, 0x08,		/*   Report Size (8)                   */
  	0x95, 0x13,		/*   Report Count (19)                 */
  	0x15, 0x00,		/*   Logical Minimum (0)               */
  	0x26, 0xff, 0x00,	/*   Logical Maximum (255)             */
  	0x09, 0x02,		/*   Usage (Vendor Usage 2)            */
  	0x81, 0x00,		/*   Input (Data,Arr,Abs)              */
  	0x09, 0x02,		/*   Usage (Vendor Usage 2)            */
  	0x91, 0x00,		/*   Output (Data,Arr,Abs)             */
  	0xc0,			/* End Collection                      */
  	0x06, 0x00, 0xff,	/* Usage Page (Vendor Defined Page 1)  */
  	0x09, 0x04,		/* Usage (Vendor Usage 0x04)           */
  	0xa1, 0x01,		/* Collection (Application)            */
  	0x85, 0x20,		/*   Report ID (32)                    */
  	0x75, 0x08,		/*   Report Size (8)                   */
  	0x95, 0x0e,		/*   Report Count (14)                 */
  	0x15, 0x00,		/*   Logical Minimum (0)               */
  	0x26, 0xff, 0x00,	/*   Logical Maximum (255)             */
  	0x09, 0x41,		/*   Usage (Vendor Usage 0x41)         */
  	0x81, 0x00,		/*   Input (Data,Arr,Abs)              */
  	0x09, 0x41,		/*   Usage (Vendor Usage 0x41)         */
  	0x91, 0x00,		/*   Output (Data,Arr,Abs)             */
  	0x85, 0x21,		/*   Report ID (33)                    */
  	0x95, 0x1f,		/*   Report Count (31)                 */
  	0x15, 0x00,		/*   Logical Minimum (0)               */
  	0x26, 0xff, 0x00,	/*   Logical Maximum (255)             */
  	0x09, 0x42,		/*   Usage (Vendor Usage 0x42)         */
  	0x81, 0x00,		/*   Input (Data,Arr,Abs)              */
  	0x09, 0x42,		/*   Usage (Vendor Usage 0x42)         */
  	0x91, 0x00,		/*   Output (Data,Arr,Abs)             */
  	0xc0,			/* End Collection                      */
  };

  /* Maximum size of all defined hid reports in bytes (including report id) */
  #define MAX_REPORT_SIZE 8

  /* Make sure all descriptors are present here */
  #define MAX_RDESC_SIZE				\
  	(sizeof(kbd_descriptor) +		\
  	 sizeof(mse_descriptor) +		\
  	 sizeof(consumer_descriptor) +		\
  	 sizeof(syscontrol_descriptor) +	\

  	 sizeof(media_descriptor) +	\
  	 sizeof(hidpp_descriptor))

  /* Number of possible hid report types that can be created by this driver.
   *
   * Right now, RF report types have the same report types (or report id's)
   * than the hid report created from those RF reports. In the future
   * this doesnt have to be true.
   *
   * For instance, RF report type 0x01 which has a size of 8 bytes, corresponds
   * to hid report id 0x01, this is standard keyboard. Same thing applies to mice
   * reports and consumer control, etc. If a new RF report is created, it doesn't
   * has to have the same report id as its corresponding hid report, so an
   * translation may have to take place for future report types.
   */
  #define NUMBER_OF_HID_REPORTS 32
  static const u8 hid_reportid_size_map[NUMBER_OF_HID_REPORTS] = {
  	[1] = 8,		/* Standard keyboard */
  	[2] = 8,		/* Standard mouse */
  	[3] = 5,		/* Consumer control */
  	[4] = 2,		/* System control */
  	[8] = 2,		/* Media Center */
  };
  
  
  #define LOGITECH_DJ_INTERFACE_NUMBER 0x02

  static struct hid_ll_driver logi_dj_ll_driver;

  static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev);

  
  static void logi_dj_recv_destroy_djhid_device(struct dj_receiver_dev *djrcv_dev,
  						struct dj_report *dj_report)
  {
  	/* Called in delayed work context */
  	struct dj_device *dj_dev;
  	unsigned long flags;
  
  	spin_lock_irqsave(&djrcv_dev->lock, flags);
  	dj_dev = djrcv_dev->paired_dj_devices[dj_report->device_index];
  	djrcv_dev->paired_dj_devices[dj_report->device_index] = NULL;
  	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
  
  	if (dj_dev != NULL) {
  		hid_destroy_device(dj_dev->hdev);
  		kfree(dj_dev);
  	} else {
  		dev_err(&djrcv_dev->hdev->dev, "%s: can't destroy a NULL device
  ",
  			__func__);
  	}
  }
  
  static void logi_dj_recv_add_djhid_device(struct dj_receiver_dev *djrcv_dev,
  					  struct dj_report *dj_report)
  {
  	/* Called in delayed work context */
  	struct hid_device *djrcv_hdev = djrcv_dev->hdev;
  	struct usb_interface *intf = to_usb_interface(djrcv_hdev->dev.parent);
  	struct usb_device *usbdev = interface_to_usbdev(intf);
  	struct hid_device *dj_hiddev;
  	struct dj_device *dj_dev;
  
  	/* Device index goes from 1 to 6, we need 3 bytes to store the
  	 * semicolon, the index, and a null terminator
  	 */
  	unsigned char tmpstr[3];
  
  	if (dj_report->report_params[DEVICE_PAIRED_PARAM_SPFUNCTION] &
  	    SPFUNCTION_DEVICE_LIST_EMPTY) {
  		dbg_hid("%s: device list is empty
  ", __func__);

  		djrcv_dev->querying_devices = false;

  		return;
  	}

  	if (djrcv_dev->paired_dj_devices[dj_report->device_index]) {
  		/* The device is already known. No need to reallocate it. */
  		dbg_hid("%s: device is already known
  ", __func__);
  		return;
  	}

  	dj_hiddev = hid_allocate_device();
  	if (IS_ERR(dj_hiddev)) {
  		dev_err(&djrcv_hdev->dev, "%s: hid_allocate_device failed
  ",
  			__func__);
  		return;
  	}
  
  	dj_hiddev->ll_driver = &logi_dj_ll_driver;

  
  	dj_hiddev->dev.parent = &djrcv_hdev->dev;
  	dj_hiddev->bus = BUS_USB;
  	dj_hiddev->vendor = le16_to_cpu(usbdev->descriptor.idVendor);

  	dj_hiddev->product =
  		(dj_report->report_params[DEVICE_PAIRED_PARAM_EQUAD_ID_MSB]
  									<< 8) |
  		dj_report->report_params[DEVICE_PAIRED_PARAM_EQUAD_ID_LSB];

  	snprintf(dj_hiddev->name, sizeof(dj_hiddev->name),

  		"Logitech Unifying Device. Wireless PID:%04x",
  		dj_hiddev->product);
  
  	dj_hiddev->group = HID_GROUP_LOGITECH_DJ_DEVICE;

  
  	usb_make_path(usbdev, dj_hiddev->phys, sizeof(dj_hiddev->phys));
  	snprintf(tmpstr, sizeof(tmpstr), ":%d", dj_report->device_index);
  	strlcat(dj_hiddev->phys, tmpstr, sizeof(dj_hiddev->phys));
  
  	dj_dev = kzalloc(sizeof(struct dj_device), GFP_KERNEL);
  
  	if (!dj_dev) {
  		dev_err(&djrcv_hdev->dev, "%s: failed allocating dj_device
  ",
  			__func__);
  		goto dj_device_allocate_fail;
  	}

  	dj_dev->reports_supported = get_unaligned_le32(
  		dj_report->report_params + DEVICE_PAIRED_RF_REPORT_TYPE);

  	dj_dev->hdev = dj_hiddev;
  	dj_dev->dj_receiver_dev = djrcv_dev;
  	dj_dev->device_index = dj_report->device_index;
  	dj_hiddev->driver_data = dj_dev;
  
  	djrcv_dev->paired_dj_devices[dj_report->device_index] = dj_dev;
  
  	if (hid_add_device(dj_hiddev)) {
  		dev_err(&djrcv_hdev->dev, "%s: failed adding dj_device
  ",
  			__func__);
  		goto hid_add_device_fail;
  	}
  
  	return;
  
  hid_add_device_fail:
  	djrcv_dev->paired_dj_devices[dj_report->device_index] = NULL;
  	kfree(dj_dev);
  dj_device_allocate_fail:
  	hid_destroy_device(dj_hiddev);
  }
  
  static void delayedwork_callback(struct work_struct *work)
  {
  	struct dj_receiver_dev *djrcv_dev =
  		container_of(work, struct dj_receiver_dev, work);
  
  	struct dj_report dj_report;
  	unsigned long flags;
  	int count;

  	int retval;

  
  	dbg_hid("%s
  ", __func__);
  
  	spin_lock_irqsave(&djrcv_dev->lock, flags);
  
  	count = kfifo_out(&djrcv_dev->notif_fifo, &dj_report,
  				sizeof(struct dj_report));
  
  	if (count != sizeof(struct dj_report)) {
  		dev_err(&djrcv_dev->hdev->dev, "%s: workitem triggered without "
  			"notifications available
  ", __func__);
  		spin_unlock_irqrestore(&djrcv_dev->lock, flags);
  		return;
  	}
  
  	if (!kfifo_is_empty(&djrcv_dev->notif_fifo)) {
  		if (schedule_work(&djrcv_dev->work) == 0) {
  			dbg_hid("%s: did not schedule the work item, was "
  				"already queued
  ", __func__);
  		}
  	}
  
  	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
  
  	switch (dj_report.report_type) {
  	case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
  		logi_dj_recv_add_djhid_device(djrcv_dev, &dj_report);
  		break;
  	case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
  		logi_dj_recv_destroy_djhid_device(djrcv_dev, &dj_report);
  		break;
  	default:

  	/* A normal report (i. e. not belonging to a pair/unpair notification)
  	 * arriving here, means that the report arrived but we did not have a
  	 * paired dj_device associated to the report's device_index, this
  	 * means that the original "device paired" notification corresponding
  	 * to this dj_device never arrived to this driver. The reason is that
  	 * hid-core discards all packets coming from a device while probe() is
  	 * executing. */
  	if (!djrcv_dev->paired_dj_devices[dj_report.device_index]) {
  		/* ok, we don't know the device, just re-ask the
  		 * receiver for the list of connected devices. */
  		retval = logi_dj_recv_query_paired_devices(djrcv_dev);
  		if (!retval) {
  			/* everything went fine, so just leave */
  			break;
  		}
  		dev_err(&djrcv_dev->hdev->dev,
  			"%s:logi_dj_recv_query_paired_devices "
  			"error:%d
  ", __func__, retval);
  		}

  		dbg_hid("%s: unexpected report type
  ", __func__);
  	}
  }
  
  static void logi_dj_recv_queue_notification(struct dj_receiver_dev *djrcv_dev,
  					   struct dj_report *dj_report)
  {
  	/* We are called from atomic context (tasklet && djrcv->lock held) */
  
  	kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
  
  	if (schedule_work(&djrcv_dev->work) == 0) {
  		dbg_hid("%s: did not schedule the work item, was already "
  			"queued
  ", __func__);
  	}
  }
  
  static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,
  					     struct dj_report *dj_report)
  {
  	/* We are called from atomic context (tasklet && djrcv->lock held) */
  	unsigned int i;
  	u8 reportbuffer[MAX_REPORT_SIZE];
  	struct dj_device *djdev;
  
  	djdev = djrcv_dev->paired_dj_devices[dj_report->device_index];

  	memset(reportbuffer, 0, sizeof(reportbuffer));
  
  	for (i = 0; i < NUMBER_OF_HID_REPORTS; i++) {
  		if (djdev->reports_supported & (1 << i)) {
  			reportbuffer[0] = i;
  			if (hid_input_report(djdev->hdev,
  					     HID_INPUT_REPORT,
  					     reportbuffer,
  					     hid_reportid_size_map[i], 1)) {
  				dbg_hid("hid_input_report error sending null "
  					"report
  ");
  			}
  		}
  	}
  }
  
  static void logi_dj_recv_forward_report(struct dj_receiver_dev *djrcv_dev,
  					struct dj_report *dj_report)
  {
  	/* We are called from atomic context (tasklet && djrcv->lock held) */
  	struct dj_device *dj_device;
  
  	dj_device = djrcv_dev->paired_dj_devices[dj_report->device_index];

  	if ((dj_report->report_type > ARRAY_SIZE(hid_reportid_size_map) - 1) ||
  	    (hid_reportid_size_map[dj_report->report_type] == 0)) {
  		dbg_hid("invalid report type:%x
  ", dj_report->report_type);
  		return;
  	}
  
  	if (hid_input_report(dj_device->hdev,
  			HID_INPUT_REPORT, &dj_report->report_type,
  			hid_reportid_size_map[dj_report->report_type], 1)) {
  		dbg_hid("hid_input_report error
  ");
  	}
  }

  static void logi_dj_recv_forward_hidpp(struct dj_device *dj_dev, u8 *data,
  				       int size)
  {
  	/* We are called from atomic context (tasklet && djrcv->lock held) */
  	if (hid_input_report(dj_dev->hdev, HID_INPUT_REPORT, data, size, 1))
  		dbg_hid("hid_input_report error
  ");
  }

  
  static int logi_dj_recv_send_report(struct dj_receiver_dev *djrcv_dev,
  				    struct dj_report *dj_report)
  {
  	struct hid_device *hdev = djrcv_dev->hdev;

  	struct hid_report *report;
  	struct hid_report_enum *output_report_enum;
  	u8 *data = (u8 *)(&dj_report->device_index);

  	unsigned int i;

  	output_report_enum = &hdev->report_enum[HID_OUTPUT_REPORT];
  	report = output_report_enum->report_id_hash[REPORT_ID_DJ_SHORT];
  
  	if (!report) {
  		dev_err(&hdev->dev, "%s: unable to find dj report
  ", __func__);

  		return -ENODEV;
  	}

  	for (i = 0; i < DJREPORT_SHORT_LENGTH - 1; i++)

  		report->field[0]->value[i] = data[i];

  	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);

  	return 0;

  }
  
  static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev)
  {

  	struct dj_report *dj_report;
  	int retval;

  	/* no need to protect djrcv_dev->querying_devices */
  	if (djrcv_dev->querying_devices)
  		return 0;

  	dj_report = kzalloc(sizeof(struct dj_report), GFP_KERNEL);

  	if (!dj_report)
  		return -ENOMEM;
  	dj_report->report_id = REPORT_ID_DJ_SHORT;
  	dj_report->device_index = 0xFF;
  	dj_report->report_type = REPORT_TYPE_CMD_GET_PAIRED_DEVICES;
  	retval = logi_dj_recv_send_report(djrcv_dev, dj_report);
  	kfree(dj_report);
  	return retval;

  }

  static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
  					  unsigned timeout)
  {

  	struct hid_device *hdev = djrcv_dev->hdev;

  	struct dj_report *dj_report;

  	u8 *buf;

  	int retval;

  	dj_report = kzalloc(sizeof(struct dj_report), GFP_KERNEL);

  	if (!dj_report)
  		return -ENOMEM;
  	dj_report->report_id = REPORT_ID_DJ_SHORT;
  	dj_report->device_index = 0xFF;
  	dj_report->report_type = REPORT_TYPE_CMD_SWITCH;
  	dj_report->report_params[CMD_SWITCH_PARAM_DEVBITFIELD] = 0x3F;
  	dj_report->report_params[CMD_SWITCH_PARAM_TIMEOUT_SECONDS] = (u8)timeout;
  	retval = logi_dj_recv_send_report(djrcv_dev, dj_report);

  
  	/*
  	 * Ugly sleep to work around a USB 3.0 bug when the receiver is still
  	 * processing the "switch-to-dj" command while we send an other command.
  	 * 50 msec should gives enough time to the receiver to be ready.
  	 */
  	msleep(50);

  	/*
  	 * Magical bits to set up hidpp notifications when the dj devices
  	 * are connected/disconnected.
  	 *
  	 * We can reuse dj_report because HIDPP_REPORT_SHORT_LENGTH is smaller
  	 * than DJREPORT_SHORT_LENGTH.
  	 */
  	buf = (u8 *)dj_report;
  
  	memset(buf, 0, HIDPP_REPORT_SHORT_LENGTH);
  
  	buf[0] = REPORT_ID_HIDPP_SHORT;
  	buf[1] = 0xFF;
  	buf[2] = 0x80;
  	buf[3] = 0x00;
  	buf[4] = 0x00;
  	buf[5] = 0x09;
  	buf[6] = 0x00;
  
  	hid_hw_raw_request(hdev, REPORT_ID_HIDPP_SHORT, buf,
  			HIDPP_REPORT_SHORT_LENGTH, HID_OUTPUT_REPORT,
  			HID_REQ_SET_REPORT);
  
  	kfree(dj_report);

  	return retval;

  }
  
  
  static int logi_dj_ll_open(struct hid_device *hid)
  {
  	dbg_hid("%s:%s
  ", __func__, hid->phys);
  	return 0;
  
  }
  
  static void logi_dj_ll_close(struct hid_device *hid)
  {
  	dbg_hid("%s:%s
  ", __func__, hid->phys);
  }

  static u8 unifying_name_query[]  = {0x10, 0xff, 0x83, 0xb5, 0x40, 0x00, 0x00};
  static u8 unifying_name_answer[] = {0x11, 0xff, 0x83, 0xb5};

  static int logi_dj_ll_raw_request(struct hid_device *hid,
  				  unsigned char reportnum, __u8 *buf,
  				  size_t count, unsigned char report_type,
  				  int reqtype)

  {

  	struct dj_device *djdev = hid->driver_data;
  	struct dj_receiver_dev *djrcv_dev = djdev->dj_receiver_dev;
  	u8 *out_buf;
  	int ret;

  	if ((buf[0] == REPORT_ID_HIDPP_SHORT) ||
  	    (buf[0] == REPORT_ID_HIDPP_LONG)) {
  		if (count < 2)
  			return -EINVAL;

  		/* special case where we should not overwrite
  		 * the device_index */
  		if (count == 7 && !memcmp(buf, unifying_name_query,
  					  sizeof(unifying_name_query)))
  			buf[4] |= djdev->device_index - 1;
  		else
  			buf[1] = djdev->device_index;

  		return hid_hw_raw_request(djrcv_dev->hdev, reportnum, buf,
  				count, report_type, reqtype);
  	}

  	if (buf[0] != REPORT_TYPE_LEDS)
  		return -EINVAL;
  
  	out_buf = kzalloc(DJREPORT_SHORT_LENGTH, GFP_ATOMIC);
  	if (!out_buf)
  		return -ENOMEM;

  	if (count > DJREPORT_SHORT_LENGTH - 2)

  		count = DJREPORT_SHORT_LENGTH - 2;
  
  	out_buf[0] = REPORT_ID_DJ_SHORT;
  	out_buf[1] = djdev->device_index;
  	memcpy(out_buf + 2, buf, count);

  	ret = hid_hw_raw_request(djrcv_dev->hdev, out_buf[0], out_buf,

  		DJREPORT_SHORT_LENGTH, report_type, reqtype);

  
  	kfree(out_buf);
  	return ret;

  }

  static void rdcat(char *rdesc, unsigned int *rsize, const char *data, unsigned int size)

  {

  	memcpy(rdesc + *rsize, data, size);

  	*rsize += size;
  }

  static int logi_dj_ll_parse(struct hid_device *hid)
  {
  	struct dj_device *djdev = hid->driver_data;

  	unsigned int rsize = 0;
  	char *rdesc;

  	int retval;
  
  	dbg_hid("%s
  ", __func__);
  
  	djdev->hdev->version = 0x0111;
  	djdev->hdev->country = 0x00;

  	rdesc = kmalloc(MAX_RDESC_SIZE, GFP_KERNEL);
  	if (!rdesc)
  		return -ENOMEM;

  	if (djdev->reports_supported & STD_KEYBOARD) {
  		dbg_hid("%s: sending a kbd descriptor, reports_supported: %x
  ",
  			__func__, djdev->reports_supported);

  		rdcat(rdesc, &rsize, kbd_descriptor, sizeof(kbd_descriptor));

  	}
  
  	if (djdev->reports_supported & STD_MOUSE) {
  		dbg_hid("%s: sending a mouse descriptor, reports_supported: "
  			"%x
  ", __func__, djdev->reports_supported);

  		rdcat(rdesc, &rsize, mse_descriptor, sizeof(mse_descriptor));

  	}
  
  	if (djdev->reports_supported & MULTIMEDIA) {
  		dbg_hid("%s: sending a multimedia report descriptor: %x
  ",
  			__func__, djdev->reports_supported);

  		rdcat(rdesc, &rsize, consumer_descriptor, sizeof(consumer_descriptor));

  	}
  
  	if (djdev->reports_supported & POWER_KEYS) {
  		dbg_hid("%s: sending a power keys report descriptor: %x
  ",
  			__func__, djdev->reports_supported);

  		rdcat(rdesc, &rsize, syscontrol_descriptor, sizeof(syscontrol_descriptor));

  	}
  
  	if (djdev->reports_supported & MEDIA_CENTER) {
  		dbg_hid("%s: sending a media center report descriptor: %x
  ",
  			__func__, djdev->reports_supported);

  		rdcat(rdesc, &rsize, media_descriptor, sizeof(media_descriptor));

  	}
  
  	if (djdev->reports_supported & KBD_LEDS) {
  		dbg_hid("%s: need to send kbd leds report descriptor: %x
  ",
  			__func__, djdev->reports_supported);
  	}

  	rdcat(rdesc, &rsize, hidpp_descriptor, sizeof(hidpp_descriptor));

  	retval = hid_parse_report(hid, rdesc, rsize);
  	kfree(rdesc);
  
  	return retval;

  }

  static int logi_dj_ll_start(struct hid_device *hid)
  {
  	dbg_hid("%s
  ", __func__);
  	return 0;
  }
  
  static void logi_dj_ll_stop(struct hid_device *hid)
  {
  	dbg_hid("%s
  ", __func__);
  }
  
  
  static struct hid_ll_driver logi_dj_ll_driver = {
  	.parse = logi_dj_ll_parse,
  	.start = logi_dj_ll_start,
  	.stop = logi_dj_ll_stop,
  	.open = logi_dj_ll_open,
  	.close = logi_dj_ll_close,

  	.raw_request = logi_dj_ll_raw_request,

  };

  static int logi_dj_dj_event(struct hid_device *hdev,

  			     struct hid_report *report, u8 *data,
  			     int size)
  {
  	struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
  	struct dj_report *dj_report = (struct dj_report *) data;
  	unsigned long flags;

  	/*
  	 * Here we receive all data coming from iface 2, there are 3 cases:

  	 *

  	 * 1) Data is intended for this driver i. e. data contains arrival,
  	 * departure, etc notifications, in which case we queue them for delayed
  	 * processing by the work queue. We return 1 to hid-core as no further
  	 * processing is required from it.

  	 *

  	 * 2) Data informs a connection change, if the change means rf link
  	 * loss, then we must send a null report to the upper layer to discard
  	 * potentially pressed keys that may be repeated forever by the input
  	 * layer. Return 1 to hid-core as no further processing is required.

  	 *

  	 * 3) Data is an actual input event from a paired DJ device in which
  	 * case we forward it to the correct hid device (via hid_input_report()
  	 * ) and return 1 so hid-core does not anything else with it.

  	 */

  	if ((dj_report->device_index < DJ_DEVICE_INDEX_MIN) ||
  	    (dj_report->device_index > DJ_DEVICE_INDEX_MAX)) {

  		/*
  		 * Device index is wrong, bail out.
  		 * This driver can ignore safely the receiver notifications,
  		 * so ignore those reports too.
  		 */
  		if (dj_report->device_index != DJ_RECEIVER_INDEX)
  			dev_err(&hdev->dev, "%s: invalid device index:%d
  ",

  				__func__, dj_report->device_index);
  		return false;
  	}

  
  	spin_lock_irqsave(&djrcv_dev->lock, flags);

  
  	if (!djrcv_dev->paired_dj_devices[dj_report->device_index]) {
  		/* received an event for an unknown device, bail out */
  		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
  		goto out;
  	}

  	switch (dj_report->report_type) {
  	case REPORT_TYPE_NOTIF_DEVICE_PAIRED:

  		/* pairing notifications are handled above the switch */
  		break;

  	case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
  		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
  		break;
  	case REPORT_TYPE_NOTIF_CONNECTION_STATUS:
  		if (dj_report->report_params[CONNECTION_STATUS_PARAM_STATUS] ==
  		    STATUS_LINKLOSS) {
  			logi_dj_recv_forward_null_report(djrcv_dev, dj_report);

  		}

  		break;
  	default:
  		logi_dj_recv_forward_report(djrcv_dev, dj_report);

  	}

  
  out:

  	spin_unlock_irqrestore(&djrcv_dev->lock, flags);

  	return true;

  }

  static int logi_dj_hidpp_event(struct hid_device *hdev,
  			     struct hid_report *report, u8 *data,
  			     int size)
  {
  	struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
  	struct dj_report *dj_report = (struct dj_report *) data;
  	unsigned long flags;
  	u8 device_index = dj_report->device_index;

  	if (device_index == HIDPP_RECEIVER_INDEX) {
  		/* special case were the device wants to know its unifying
  		 * name */
  		if (size == HIDPP_REPORT_LONG_LENGTH &&
  		    !memcmp(data, unifying_name_answer,
  			    sizeof(unifying_name_answer)) &&
  		    ((data[4] & 0xF0) == 0x40))
  			device_index = (data[4] & 0x0F) + 1;
  		else
  			return false;
  	}

  
  	/*
  	 * Data is from the HID++ collection, in this case, we forward the
  	 * data to the corresponding child dj device and return 0 to hid-core
  	 * so he data also goes to the hidraw device of the receiver. This
  	 * allows a user space application to implement the full HID++ routing
  	 * via the receiver.
  	 */
  
  	if ((device_index < DJ_DEVICE_INDEX_MIN) ||
  	    (device_index > DJ_DEVICE_INDEX_MAX)) {
  		/*
  		 * Device index is wrong, bail out.
  		 * This driver can ignore safely the receiver notifications,
  		 * so ignore those reports too.
  		 */
  		dev_err(&hdev->dev, "%s: invalid device index:%d
  ",
  				__func__, dj_report->device_index);
  		return false;
  	}
  
  	spin_lock_irqsave(&djrcv_dev->lock, flags);
  
  	if (!djrcv_dev->paired_dj_devices[device_index])
  		/* received an event for an unknown device, bail out */
  		goto out;
  
  	logi_dj_recv_forward_hidpp(djrcv_dev->paired_dj_devices[device_index],
  				   data, size);
  
  out:
  	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
  
  	return false;
  }
  
  static int logi_dj_raw_event(struct hid_device *hdev,
  			     struct hid_report *report, u8 *data,
  			     int size)
  {
  	dbg_hid("%s, size:%d
  ", __func__, size);
  
  	switch (data[0]) {
  	case REPORT_ID_DJ_SHORT:

  		if (size != DJREPORT_SHORT_LENGTH) {
  			dev_err(&hdev->dev, "DJ report of bad size (%d)", size);
  			return false;
  		}

  		return logi_dj_dj_event(hdev, report, data, size);
  	case REPORT_ID_HIDPP_SHORT:

  		if (size != HIDPP_REPORT_SHORT_LENGTH) {
  			dev_err(&hdev->dev,
  				"Short HID++ report of bad size (%d)", size);
  			return false;
  		}
  		return logi_dj_hidpp_event(hdev, report, data, size);

  	case REPORT_ID_HIDPP_LONG:

  		if (size != HIDPP_REPORT_LONG_LENGTH) {
  			dev_err(&hdev->dev,
  				"Long HID++ report of bad size (%d)", size);
  			return false;
  		}

  		return logi_dj_hidpp_event(hdev, report, data, size);
  	}
  
  	return false;
  }

  static int logi_dj_probe(struct hid_device *hdev,
  			 const struct hid_device_id *id)
  {
  	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
  	struct dj_receiver_dev *djrcv_dev;
  	int retval;

  	dbg_hid("%s called for ifnum %d
  ", __func__,
  		intf->cur_altsetting->desc.bInterfaceNumber);
  
  	/* Ignore interfaces 0 and 1, they will not carry any data, dont create
  	 * any hid_device for them */
  	if (intf->cur_altsetting->desc.bInterfaceNumber !=
  	    LOGITECH_DJ_INTERFACE_NUMBER) {
  		dbg_hid("%s: ignoring ifnum %d
  ", __func__,
  			intf->cur_altsetting->desc.bInterfaceNumber);
  		return -ENODEV;
  	}
  
  	/* Treat interface 2 */
  
  	djrcv_dev = kzalloc(sizeof(struct dj_receiver_dev), GFP_KERNEL);
  	if (!djrcv_dev) {
  		dev_err(&hdev->dev,
  			"%s:failed allocating dj_receiver_dev
  ", __func__);
  		return -ENOMEM;
  	}
  	djrcv_dev->hdev = hdev;
  	INIT_WORK(&djrcv_dev->work, delayedwork_callback);
  	spin_lock_init(&djrcv_dev->lock);
  	if (kfifo_alloc(&djrcv_dev->notif_fifo,
  			DJ_MAX_NUMBER_NOTIFICATIONS * sizeof(struct dj_report),
  			GFP_KERNEL)) {
  		dev_err(&hdev->dev,
  			"%s:failed allocating notif_fifo
  ", __func__);
  		kfree(djrcv_dev);
  		return -ENOMEM;
  	}
  	hid_set_drvdata(hdev, djrcv_dev);
  
  	/* Call  to usbhid to fetch the HID descriptors of interface 2 and
  	 * subsequently call to the hid/hid-core to parse the fetched
  	 * descriptors, this will in turn create the hidraw and hiddev nodes
  	 * for interface 2 of the receiver */
  	retval = hid_parse(hdev);
  	if (retval) {
  		dev_err(&hdev->dev,
  			"%s:parse of interface 2 failed
  ", __func__);
  		goto hid_parse_fail;
  	}

  	if (!hid_validate_values(hdev, HID_OUTPUT_REPORT, REPORT_ID_DJ_SHORT,
  				 0, DJREPORT_SHORT_LENGTH - 1)) {
  		retval = -ENODEV;
  		goto hid_parse_fail;
  	}

  	/* Starts the usb device and connects to upper interfaces hiddev and
  	 * hidraw */
  	retval = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
  	if (retval) {
  		dev_err(&hdev->dev,
  			"%s:hid_hw_start returned error
  ", __func__);
  		goto hid_hw_start_fail;
  	}
  
  	retval = logi_dj_recv_switch_to_dj_mode(djrcv_dev, 0);
  	if (retval < 0) {
  		dev_err(&hdev->dev,
  			"%s:logi_dj_recv_switch_to_dj_mode returned error:%d
  ",
  			__func__, retval);
  		goto switch_to_dj_mode_fail;
  	}
  
  	/* This is enabling the polling urb on the IN endpoint */

  	retval = hid_hw_open(hdev);

  	if (retval < 0) {

  		dev_err(&hdev->dev, "%s:hid_hw_open returned error:%d
  ",
  			__func__, retval);

  		goto llopen_failed;
  	}

  	/* Allow incoming packets to arrive: */
  	hid_device_io_start(hdev);

  	retval = logi_dj_recv_query_paired_devices(djrcv_dev);
  	if (retval < 0) {
  		dev_err(&hdev->dev, "%s:logi_dj_recv_query_paired_devices "
  			"error:%d
  ", __func__, retval);
  		goto logi_dj_recv_query_paired_devices_failed;
  	}
  
  	return retval;
  
  logi_dj_recv_query_paired_devices_failed:

  	hid_hw_close(hdev);

  
  llopen_failed:
  switch_to_dj_mode_fail:
  	hid_hw_stop(hdev);
  
  hid_hw_start_fail:
  hid_parse_fail:
  	kfifo_free(&djrcv_dev->notif_fifo);
  	kfree(djrcv_dev);
  	hid_set_drvdata(hdev, NULL);
  	return retval;
  
  }
  
  #ifdef CONFIG_PM
  static int logi_dj_reset_resume(struct hid_device *hdev)
  {
  	int retval;
  	struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
  
  	retval = logi_dj_recv_switch_to_dj_mode(djrcv_dev, 0);
  	if (retval < 0) {
  		dev_err(&hdev->dev,
  			"%s:logi_dj_recv_switch_to_dj_mode returned error:%d
  ",
  			__func__, retval);
  	}
  
  	return 0;
  }
  #endif
  
  static void logi_dj_remove(struct hid_device *hdev)
  {
  	struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
  	struct dj_device *dj_dev;
  	int i;
  
  	dbg_hid("%s
  ", __func__);
  
  	cancel_work_sync(&djrcv_dev->work);

  	hid_hw_close(hdev);

  	hid_hw_stop(hdev);
  
  	/* I suppose that at this point the only context that can access
  	 * the djrecv_data is this thread as the work item is guaranteed to
  	 * have finished and no more raw_event callbacks should arrive after
  	 * the remove callback was triggered so no locks are put around the
  	 * code below */

  	for (i = 0; i < (DJ_MAX_PAIRED_DEVICES + DJ_DEVICE_INDEX_MIN); i++) {

  		dj_dev = djrcv_dev->paired_dj_devices[i];
  		if (dj_dev != NULL) {
  			hid_destroy_device(dj_dev->hdev);
  			kfree(dj_dev);
  			djrcv_dev->paired_dj_devices[i] = NULL;
  		}
  	}
  
  	kfifo_free(&djrcv_dev->notif_fifo);
  	kfree(djrcv_dev);
  	hid_set_drvdata(hdev, NULL);
  }

  static const struct hid_device_id logi_dj_receivers[] = {
  	{HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
  		USB_DEVICE_ID_LOGITECH_UNIFYING_RECEIVER)},
  	{HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
  		USB_DEVICE_ID_LOGITECH_UNIFYING_RECEIVER_2)},
  	{}
  };
  
  MODULE_DEVICE_TABLE(hid, logi_dj_receivers);
  
  static struct hid_driver logi_djreceiver_driver = {
  	.name = "logitech-djreceiver",
  	.id_table = logi_dj_receivers,
  	.probe = logi_dj_probe,
  	.remove = logi_dj_remove,
  	.raw_event = logi_dj_raw_event,
  #ifdef CONFIG_PM
  	.reset_resume = logi_dj_reset_resume,
  #endif
  };

  module_hid_driver(logi_djreceiver_driver);

  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Logitech");
  MODULE_AUTHOR("Nestor Lopez Casado");
  MODULE_AUTHOR("nlopezcasad@logitech.com");