// SPDX-License-Identifier: GPL-2.0-only
/*
 *  HID driver for Logitech receivers
 *
 *  Copyright (c) 2011 Logitech
 */



#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/kfifo.h>
#include <linux/delay.h>
#include <linux/usb.h> /* For to_usb_interface for kvm extra intf check */
#include <asm/unaligned.h>
#include "hid-ids.h"

#define DJ_MAX_PAIRED_DEVICES                   7
#define DJ_MAX_NUMBER_NOTIFS                    8
#define DJ_RECEIVER_INDEX                       0
#define DJ_DEVICE_INDEX_MIN                     1
#define DJ_DEVICE_INDEX_MAX                     7

#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 REPORT_ID_HIDPP_VERY_LONG               0x12

#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                            BIT(1)
#define STD_MOUSE                               BIT(2)
#define MULTIMEDIA                              BIT(3)
#define POWER_KEYS                              BIT(4)
#define KBD_MOUSE                               BIT(5)
#define MEDIA_CENTER                            BIT(8)
#define KBD_LEDS                                BIT(14)
/* Fake (bitnr > NUMBER_OF_HID_REPORTS) bit to track HID++ capability */
#define HIDPP                                   BIT_ULL(63)

/* HID++ Device Connected Notification */
#define REPORT_TYPE_NOTIF_DEVICE_CONNECTED      0x41
#define HIDPP_PARAM_PROTO_TYPE                  0x00
#define HIDPP_PARAM_DEVICE_INFO                 0x01
#define HIDPP_PARAM_EQUAD_LSB                   0x02
#define HIDPP_PARAM_EQUAD_MSB                   0x03
#define HIDPP_PARAM_27MHZ_DEVID                 0x03
#define HIDPP_DEVICE_TYPE_MASK                  GENMASK(3, 0)
#define HIDPP_LINK_STATUS_MASK                  BIT(6)
#define HIDPP_MANUFACTURER_MASK                 BIT(7)
#define HIDPP_27MHZ_SECURE_MASK                 BIT(7)

#define HIDPP_DEVICE_TYPE_KEYBOARD              1
#define HIDPP_DEVICE_TYPE_MOUSE                 2

#define HIDPP_SET_REGISTER                      0x80
#define HIDPP_GET_LONG_REGISTER                 0x83
#define HIDPP_REG_CONNECTION_STATE              0x02
#define HIDPP_REG_PAIRING_INFORMATION           0xB5
#define HIDPP_PAIRING_INFORMATION               0x20
#define HIDPP_FAKE_DEVICE_ARRIVAL               0x02

enum recvr_type {
        recvr_type_dj,
        recvr_type_hidpp,
        recvr_type_gaming_hidpp,
        recvr_type_mouse_only,
        recvr_type_27mhz,
        recvr_type_bluetooth,
        recvr_type_dinovo,
};

struct dj_report {
        u8 report_id;
        u8 device_index;
        u8 report_type;
        u8 report_params[DJREPORT_SHORT_LENGTH - 3];
};

struct hidpp_event {
        u8 report_id;
        u8 device_index;
        u8 sub_id;
        u8 params[HIDPP_REPORT_LONG_LENGTH - 3U];
} __packed;

struct dj_receiver_dev {
        struct hid_device *mouse;
        struct hid_device *keyboard;
        struct hid_device *hidpp;
        struct dj_device *paired_dj_devices[DJ_MAX_PAIRED_DEVICES +
                                            DJ_DEVICE_INDEX_MIN];
        struct list_head list;
        struct kref kref;
        struct work_struct work;
        struct kfifo notif_fifo;
        unsigned long last_query; /* in jiffies */
        bool ready;
        enum recvr_type type;
        unsigned int unnumbered_application;
        spinlock_t lock;
};

struct dj_device {
        struct hid_device *hdev;
        struct dj_receiver_dev *dj_receiver_dev;
        u64 reports_supported;
        u8 device_index;
};

#define WORKITEM_TYPE_EMPTY     0
#define WORKITEM_TYPE_PAIRED    1
#define WORKITEM_TYPE_UNPAIRED  2
#define WORKITEM_TYPE_UNKNOWN   255

struct dj_workitem {
        u8 type;                /* WORKITEM_TYPE_* */
        u8 device_index;
        u8 device_type;
        u8 quad_id_msb;
        u8 quad_id_lsb;
        u64 reports_supported;
};

/* 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                      */
};

/* Mouse descriptor (2) for 27 MHz receiver, only 8 buttons */
static const char mse_27mhz_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, 0x08,             /*      USAGE_MAX (8)                   */
        0x15, 0x00,             /*      LOGICAL_MIN (0)                 */
        0x25, 0x01,             /*      LOGICAL_MAX (1)                 */
        0x95, 0x08,             /*      REPORT_COUNT (8)                */
        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                      */
};

/* Mouse descriptor (2) for Bluetooth receiver, low-res hwheel, 12 buttons */
static const char mse_bluetooth_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, 0x08,             /*      USAGE_MAX (8)                   */
        0x15, 0x00,             /*      LOGICAL_MIN (0)                 */
        0x25, 0x01,             /*      LOGICAL_MAX (1)                 */
        0x95, 0x08,             /*      REPORT_COUNT (8)                */
        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)                   */
        0x15, 0xF9,             /*      LOGICAL_MIN (-7)                */
        0x25, 0x07,             /*      LOGICAL_MAX (7)                 */
        0x75, 0x04,             /*      REPORT_SIZE (4)                 */
        0x95, 0x01,             /*      REPORT_COUNT (1)                */
        0x81, 0x06,             /*      INPUT                           */
        0x05, 0x09,             /*      USAGE_PAGE (buttons)            */
        0x19, 0x09,             /*      USAGE_MIN (9)                   */
        0x29, 0x0C,             /*      USAGE_MAX (12)                  */
        0x15, 0x00,             /*      LOGICAL_MIN (0)                 */
        0x25, 0x01,             /*      LOGICAL_MAX (1)                 */
        0x75, 0x01,             /*      REPORT_SIZE (1)                 */
        0x95, 0x04,             /*      REPORT_COUNT (4)                */
        0x81, 0x02,             /*      INPUT (Data,Var,Abs)            */
        0xC0,                   /*    END_COLLECTION                    */
        0xC0,                   /*  END_COLLECTION                      */
};

/* Mouse descriptor (5) for Bluetooth receiver, normal-res hwheel, 8 buttons */
static const char mse5_bluetooth_descriptor[] = {
        0x05, 0x01,             /*  USAGE_PAGE (Generic Desktop)        */
        0x09, 0x02,             /*  Usage (Mouse)                       */
        0xa1, 0x01,             /*  Collection (Application)            */
        0x85, 0x05,             /*   Report ID (5)                      */
        0x09, 0x01,             /*   Usage (Pointer)                    */
        0xa1, 0x00,             /*   Collection (Physical)              */
        0x05, 0x09,             /*    Usage Page (Button)               */
        0x19, 0x01,             /*    Usage Minimum (1)                 */
        0x29, 0x08,             /*    Usage Maximum (8)                 */
        0x15, 0x00,             /*    Logical Minimum (0)               */
        0x25, 0x01,             /*    Logical Maximum (1)               */
        0x95, 0x08,             /*    Report Count (8)                  */
        0x75, 0x01,             /*    Report Size (1)                   */
        0x81, 0x02,             /*    Input (Data,Var,Abs)              */
        0x05, 0x01,             /*    Usage Page (Generic Desktop)      */
        0x16, 0x01, 0xf8,       /*    Logical Minimum (-2047)           */
        0x26, 0xff, 0x07,       /*    Logical Maximum (2047)            */
        0x75, 0x0c,             /*    Report Size (12)                  */
        0x95, 0x02,             /*    Report Count (2)                  */
        0x09, 0x30,             /*    Usage (X)                         */
        0x09, 0x31,             /*    Usage (Y)                         */
        0x81, 0x06,             /*    Input (Data,Var,Rel)              */
        0x15, 0x81,             /*    Logical Minimum (-127)            */
        0x25, 0x7f,             /*    Logical Maximum (127)             */
        0x75, 0x08,             /*    Report Size (8)                   */
        0x95, 0x01,             /*    Report Count (1)                  */
        0x09, 0x38,             /*    Usage (Wheel)                     */
        0x81, 0x06,             /*    Input (Data,Var,Rel)              */
        0x05, 0x0c,             /*    Usage Page (Consumer Devices)     */
        0x0a, 0x38, 0x02,       /*    Usage (AC Pan)                    */
        0x15, 0x81,             /*    Logical Minimum (-127)            */
        0x25, 0x7f,             /*    Logical Maximum (127)             */
        0x75, 0x08,             /*    Report Size (8)                   */
        0x95, 0x01,             /*    Report Count (1)                  */
        0x81, 0x06,             /*    Input (Data,Var,Rel)              */
        0xc0,                   /*   End Collection                     */
        0xc0,                   /*  End Collection                      */
};

/* Gaming Mouse descriptor (2) */
static const char mse_high_res_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, 0x80,       /*      LOGICAL_MIN (-32767)            */
        0x26, 0xFF, 0x7F,       /*      LOGICAL_MAX (32767)             */
        0x75, 0x10,             /*      REPORT_SIZE (16)                */
        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, 0xFF, 0x02,       /* LOGICAL_MAX (767)                   */
        0x19, 0x01,             /* USAGE_MIN (1)                       */
        0x2A, 0xFF, 0x02,       /* USAGE_MAX (767)                     */
        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_bluetooth_descriptor) +     \
         sizeof(mse5_bluetooth_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 delayedwork_callback(struct work_struct *work);

static LIST_HEAD(dj_hdev_list);
static DEFINE_MUTEX(dj_hdev_list_lock);

static bool recvr_type_is_bluetooth(enum recvr_type type)
{
        return type == recvr_type_bluetooth || type == recvr_type_dinovo;
}

/*
 * dj/HID++ receivers are really a single logical entity, but for BIOS/Windows
 * compatibility they have multiple USB interfaces. On HID++ receivers we need
 * to listen for input reports on both interfaces. The functions below are used
 * to create a single struct dj_receiver_dev for all interfaces belonging to
 * a single USB-device / receiver.
 */
static struct dj_receiver_dev *dj_find_receiver_dev(struct hid_device *hdev,
                                                    enum recvr_type type)
{
        struct dj_receiver_dev *djrcv_dev;
        char sep;

        /*
         * The bluetooth receiver contains a built-in hub and has separate
         * USB-devices for the keyboard and mouse interfaces.
         */
        sep = recvr_type_is_bluetooth(type) ? '.' : '/';

        /* Try to find an already-probed interface from the same device */
        list_for_each_entry(djrcv_dev, &dj_hdev_list, list) {
                if (djrcv_dev->mouse &&
                    hid_compare_device_paths(hdev, djrcv_dev->mouse, sep)) {
                        kref_get(&djrcv_dev->kref);
                        return djrcv_dev;
                }
                if (djrcv_dev->keyboard &&
                    hid_compare_device_paths(hdev, djrcv_dev->keyboard, sep)) {
                        kref_get(&djrcv_dev->kref);
                        return djrcv_dev;
                }
                if (djrcv_dev->hidpp &&
                    hid_compare_device_paths(hdev, djrcv_dev->hidpp, sep)) {
                        kref_get(&djrcv_dev->kref);
                        return djrcv_dev;
                }
        }

        return NULL;
}

static void dj_release_receiver_dev(struct kref *kref)
{
        struct dj_receiver_dev *djrcv_dev = container_of(kref, struct dj_receiver_dev, kref);

        list_del(&djrcv_dev->list);
        kfifo_free(&djrcv_dev->notif_fifo);
        kfree(djrcv_dev);
}

static void dj_put_receiver_dev(struct hid_device *hdev)
{
        struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);

        mutex_lock(&dj_hdev_list_lock);

        if (djrcv_dev->mouse == hdev)
                djrcv_dev->mouse = NULL;
        if (djrcv_dev->keyboard == hdev)
                djrcv_dev->keyboard = NULL;
        if (djrcv_dev->hidpp == hdev)
                djrcv_dev->hidpp = NULL;

        kref_put(&djrcv_dev->kref, dj_release_receiver_dev);

        mutex_unlock(&dj_hdev_list_lock);
}

static struct dj_receiver_dev *dj_get_receiver_dev(struct hid_device *hdev,
                                                   enum recvr_type type,
                                                   unsigned int application,
                                                   bool is_hidpp)
{
        struct dj_receiver_dev *djrcv_dev;

        mutex_lock(&dj_hdev_list_lock);

        djrcv_dev = dj_find_receiver_dev(hdev, type);
        if (!djrcv_dev) {
                djrcv_dev = kzalloc(sizeof(*djrcv_dev), GFP_KERNEL);
                if (!djrcv_dev)
                        goto out;

                INIT_WORK(&djrcv_dev->work, delayedwork_callback);
                spin_lock_init(&djrcv_dev->lock);
                if (kfifo_alloc(&djrcv_dev->notif_fifo,
                            DJ_MAX_NUMBER_NOTIFS * sizeof(struct dj_workitem),
                            GFP_KERNEL)) {
                        kfree(djrcv_dev);
                        djrcv_dev = NULL;
                        goto out;
                }
                kref_init(&djrcv_dev->kref);
                list_add_tail(&djrcv_dev->list, &dj_hdev_list);
                djrcv_dev->last_query = jiffies;
                djrcv_dev->type = type;
        }

        if (application == HID_GD_KEYBOARD)
                djrcv_dev->keyboard = hdev;
        if (application == HID_GD_MOUSE)
                djrcv_dev->mouse = hdev;
        if (is_hidpp)
                djrcv_dev->hidpp = hdev;

        hid_set_drvdata(hdev, djrcv_dev);
out:
        mutex_unlock(&dj_hdev_list_lock);
        return djrcv_dev;
}

static void logi_dj_recv_destroy_djhid_device(struct dj_receiver_dev *djrcv_dev,
                                              struct dj_workitem *workitem)
{
        /* 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[workitem->device_index];
        djrcv_dev->paired_dj_devices[workitem->device_index] = NULL;
        spin_unlock_irqrestore(&djrcv_dev->lock, flags);

        if (dj_dev != NULL) {
                hid_destroy_device(dj_dev->hdev);
                kfree(dj_dev);
        } else {
                hid_err(djrcv_dev->hidpp, "%s: can't destroy a NULL device\n",
                        __func__);
        }
}

static void logi_dj_recv_add_djhid_device(struct dj_receiver_dev *djrcv_dev,
                                          struct dj_workitem *workitem)
{
        /* Called in delayed work context */
        struct hid_device *djrcv_hdev = djrcv_dev->hidpp;
        struct hid_device *dj_hiddev;
        struct dj_device *dj_dev;
        u8 device_index = workitem->device_index;
        unsigned long flags;

        /* 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];

        /* We are the only one ever adding a device, no need to lock */
        if (djrcv_dev->paired_dj_devices[device_index]) {
                /* The device is already known. No need to reallocate it. */
                dbg_hid("%s: device is already known\n", __func__);
                return;
        }

        dj_hiddev = hid_allocate_device();
        if (IS_ERR(dj_hiddev)) {
                hid_err(djrcv_hdev, "%s: hid_allocate_dev failed\n", __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 = djrcv_hdev->vendor;
        dj_hiddev->product = (workitem->quad_id_msb << 8) |
                              workitem->quad_id_lsb;
        if (workitem->device_type) {
                const char *type_str = "Device";

                switch (workitem->device_type) {
                case 0x01: type_str = "Keyboard";       break;
                case 0x02: type_str = "Mouse";          break;
                case 0x03: type_str = "Numpad";         break;
                case 0x04: type_str = "Presenter";      break;
                case 0x07: type_str = "Remote Control"; break;
                case 0x08: type_str = "Trackball";      break;
                case 0x09: type_str = "Touchpad";       break;
                }
                snprintf(dj_hiddev->name, sizeof(dj_hiddev->name),
                        "Logitech Wireless %s PID:%04x",
                        type_str, dj_hiddev->product);
        } else {
                snprintf(dj_hiddev->name, sizeof(dj_hiddev->name),
                        "Logitech Wireless Device PID:%04x",
                        dj_hiddev->product);
        }

        if (djrcv_dev->type == recvr_type_27mhz)
                dj_hiddev->group = HID_GROUP_LOGITECH_27MHZ_DEVICE;
        else
                dj_hiddev->group = HID_GROUP_LOGITECH_DJ_DEVICE;

        memcpy(dj_hiddev->phys, djrcv_hdev->phys, sizeof(djrcv_hdev->phys));
        snprintf(tmpstr, sizeof(tmpstr), ":%d", device_index);
        strlcat(dj_hiddev->phys, tmpstr, sizeof(dj_hiddev->phys));

        dj_dev = kzalloc(sizeof(struct dj_device), GFP_KERNEL);

        if (!dj_dev) {
                hid_err(djrcv_hdev, "%s: failed allocating dj_dev\n", __func__);
                goto dj_device_allocate_fail;
        }

        dj_dev->reports_supported = workitem->reports_supported;
        dj_dev->hdev = dj_hiddev;
        dj_dev->dj_receiver_dev = djrcv_dev;
        dj_dev->device_index = device_index;
        dj_hiddev->driver_data = dj_dev;

        spin_lock_irqsave(&djrcv_dev->lock, flags);
        djrcv_dev->paired_dj_devices[device_index] = dj_dev;
        spin_unlock_irqrestore(&djrcv_dev->lock, flags);

        if (hid_add_device(dj_hiddev)) {
                hid_err(djrcv_hdev, "%s: failed adding dj_device\n", __func__);
                goto hid_add_device_fail;
        }

        return;

hid_add_device_fail:
        spin_lock_irqsave(&djrcv_dev->lock, flags);
        djrcv_dev->paired_dj_devices[device_index] = NULL;
        spin_unlock_irqrestore(&djrcv_dev->lock, flags);
        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_workitem workitem;
        unsigned long flags;
        int count;
        int retval;

        dbg_hid("%s\n", __func__);

        spin_lock_irqsave(&djrcv_dev->lock, flags);

        /*
         * Since we attach to multiple interfaces, we may get scheduled before
         * we are bound to the HID++ interface, catch this.
         */
        if (!djrcv_dev->ready) {
                pr_warn("%s: delayedwork queued before hidpp interface was enumerated\n",
                        __func__);
                spin_unlock_irqrestore(&djrcv_dev->lock, flags);
                return;
        }

        count = kfifo_out(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));

        if (count != sizeof(workitem)) {
                spin_unlock_irqrestore(&djrcv_dev->lock, flags);
                return;
        }

        if (!kfifo_is_empty(&djrcv_dev->notif_fifo))
                schedule_work(&djrcv_dev->work);

        spin_unlock_irqrestore(&djrcv_dev->lock, flags);

        switch (workitem.type) {
        case WORKITEM_TYPE_PAIRED:
                logi_dj_recv_add_djhid_device(djrcv_dev, &workitem);
                break;
        case WORKITEM_TYPE_UNPAIRED:
                logi_dj_recv_destroy_djhid_device(djrcv_dev, &workitem);
                break;
        case WORKITEM_TYPE_UNKNOWN:
                retval = logi_dj_recv_query_paired_devices(djrcv_dev);
                if (retval) {
                        hid_err(djrcv_dev->hidpp, "%s: logi_dj_recv_query_paired_devices error: %d\n",
                                __func__, retval);
                }
                break;
        case WORKITEM_TYPE_EMPTY:
                dbg_hid("%s: device list is empty\n", __func__);
                break;
        }
}

/*
 * Sometimes we receive reports for which we do not have a paired dj_device
 * associated with the device_index or report-type to forward the report to.
 * This means that the original "device paired" notification corresponding
 * to the dj_device never arrived to this driver. Possible reasons for this are:
 * 1) hid-core discards all packets coming from a device during probe().
 * 2) if the receiver is plugged into a KVM switch then the pairing reports
 * are only forwarded to it if the focus is on this PC.
 * This function deals with this by re-asking the receiver for the list of
 * connected devices in the delayed work callback.
 * This function MUST be called with djrcv->lock held.
 */
static void logi_dj_recv_queue_unknown_work(struct dj_receiver_dev *djrcv_dev)
{
        struct dj_workitem workitem = { .type = WORKITEM_TYPE_UNKNOWN };

        /* Rate limit queries done because of unhandled reports to 2/sec */
        if (time_before(jiffies, djrcv_dev->last_query + HZ / 2))
                return;

        kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));
        schedule_work(&djrcv_dev->work);
}

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) */
        struct dj_workitem workitem = {
                .device_index = dj_report->device_index,
        };

        switch (dj_report->report_type) {
        case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
                workitem.type = WORKITEM_TYPE_PAIRED;
                if (dj_report->report_params[DEVICE_PAIRED_PARAM_SPFUNCTION] &
                    SPFUNCTION_DEVICE_LIST_EMPTY) {
                        workitem.type = WORKITEM_TYPE_EMPTY;
                        break;
                }
                fallthrough;
        case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
                workitem.quad_id_msb =
                        dj_report->report_params[DEVICE_PAIRED_PARAM_EQUAD_ID_MSB];
                workitem.quad_id_lsb =
                        dj_report->report_params[DEVICE_PAIRED_PARAM_EQUAD_ID_LSB];
                workitem.reports_supported = get_unaligned_le32(
                                                dj_report->report_params +
                                                DEVICE_PAIRED_RF_REPORT_TYPE);
                workitem.reports_supported |= HIDPP;
                if (dj_report->report_type == REPORT_TYPE_NOTIF_DEVICE_UNPAIRED)
                        workitem.type = WORKITEM_TYPE_UNPAIRED;
                break;
        default:
                logi_dj_recv_queue_unknown_work(djrcv_dev);
                return;
        }

        kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));
        schedule_work(&djrcv_dev->work);
}

/*
 * Some quad/bluetooth keyboards have a builtin touchpad in this case we see
 * only 1 paired device with a device_type of REPORT_TYPE_KEYBOARD. For the
 * touchpad to work we must also forward mouse input reports to the dj_hiddev
 * created for the keyboard (instead of forwarding them to a second paired
 * device with a device_type of REPORT_TYPE_MOUSE as we normally would).
 *
 * On Dinovo receivers the keyboard's touchpad and an optional paired actual
 * mouse send separate input reports, INPUT(2) aka STD_MOUSE for the mouse
 * and INPUT(5) aka KBD_MOUSE for the keyboard's touchpad.
 *
 * On MX5x00 receivers (which can also be paired with a Dinovo keyboard)
 * INPUT(2) is used for both an optional paired actual mouse and for the
 * keyboard's touchpad.
 */
static const u16 kbd_builtin_touchpad_ids[] = {
        0xb309, /* Dinovo Edge */
        0xb30c, /* Dinovo Mini */
};

static void logi_hidpp_dev_conn_notif_equad(struct hid_device *hdev,
                                            struct hidpp_event *hidpp_report,
                                            struct dj_workitem *workitem)
{
        struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
        int i, id;

        workitem->type = WORKITEM_TYPE_PAIRED;
        workitem->device_type = hidpp_report->params[HIDPP_PARAM_DEVICE_INFO] &
                                HIDPP_DEVICE_TYPE_MASK;
        workitem->quad_id_msb = hidpp_report->params[HIDPP_PARAM_EQUAD_MSB];
        workitem->quad_id_lsb = hidpp_report->params[HIDPP_PARAM_EQUAD_LSB];
        switch (workitem->device_type) {
        case REPORT_TYPE_KEYBOARD:
                workitem->reports_supported |= STD_KEYBOARD | MULTIMEDIA |
                                               POWER_KEYS | MEDIA_CENTER |
                                               HIDPP;
                id = (workitem->quad_id_msb << 8) | workitem->quad_id_lsb;
                for (i = 0; i < ARRAY_SIZE(kbd_builtin_touchpad_ids); i++) {
                        if (id == kbd_builtin_touchpad_ids[i]) {
                                if (djrcv_dev->type == recvr_type_dinovo)
                                        workitem->reports_supported |= KBD_MOUSE;
                                else
                                        workitem->reports_supported |= STD_MOUSE;
                                break;
                        }
                }
                break;
        case REPORT_TYPE_MOUSE:
                workitem->reports_supported |= STD_MOUSE | HIDPP;
                if (djrcv_dev->type == recvr_type_mouse_only)
                        workitem->reports_supported |= MULTIMEDIA;
                break;
        }
}

static void logi_hidpp_dev_conn_notif_27mhz(struct hid_device *hdev,
                                            struct hidpp_event *hidpp_report,
                                            struct dj_workitem *workitem)
{
        workitem->type = WORKITEM_TYPE_PAIRED;
        workitem->quad_id_lsb = hidpp_report->params[HIDPP_PARAM_27MHZ_DEVID];
        switch (hidpp_report->device_index) {
        case 1: /* Index 1 is always a mouse */
        case 2: /* Index 2 is always a mouse */
                workitem->device_type = HIDPP_DEVICE_TYPE_MOUSE;
                workitem->reports_supported |= STD_MOUSE | HIDPP;
                break;
        case 3: /* Index 3 is always the keyboard */
                if (hidpp_report->params[HIDPP_PARAM_DEVICE_INFO] & HIDPP_27MHZ_SECURE_MASK) {
                        hid_info(hdev, "Keyboard connection is encrypted\n");
                } else {
                        hid_warn(hdev, "Keyboard events are send over the air in plain-text / unencrypted\n");
                        hid_warn(hdev, "See: https://gitlab.freedesktop.org/jwrdegoede/logitech-27mhz-keyboard-encryption-setup/\n");
                }
                fallthrough;
        case 4: /* Index 4 is used for an optional separate numpad */
                workitem->device_type = HIDPP_DEVICE_TYPE_KEYBOARD;
                workitem->reports_supported |= STD_KEYBOARD | MULTIMEDIA |
                                               POWER_KEYS | HIDPP;
                break;
        default:

                hid_warn(hdev, "%s: unexpected device-index %d", __func__,
                         hidpp_report->device_index);
        }
}

static void logi_hidpp_recv_queue_notif(struct hid_device *hdev,
                                        struct hidpp_event *hidpp_report)
{
        /* We are called from atomic context (tasklet && djrcv->lock held) */
        struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
        const char *device_type = "UNKNOWN";
        struct dj_workitem workitem = {
                .type = WORKITEM_TYPE_EMPTY,
                .device_index = hidpp_report->device_index,
        };

        switch (hidpp_report->params[HIDPP_PARAM_PROTO_TYPE]) {
        case 0x01:
                device_type = "Bluetooth";
                /* Bluetooth connect packet contents is the same as (e)QUAD */
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                if (!(hidpp_report->params[HIDPP_PARAM_DEVICE_INFO] &
                                                HIDPP_MANUFACTURER_MASK)) {
                        hid_info(hdev, "Non Logitech device connected on slot %d\n",
                                 hidpp_report->device_index);
                        workitem.reports_supported &= ~HIDPP;
                }
                break;
        case 0x02:
                device_type = "27 Mhz";
                logi_hidpp_dev_conn_notif_27mhz(hdev, hidpp_report, &workitem);
                break;
        case 0x03:
                device_type = "QUAD or eQUAD";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                break;
        case 0x04:
                device_type = "eQUAD step 4 DJ";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                break;
        case 0x05:
                device_type = "DFU Lite";
                break;
        case 0x06:
                device_type = "eQUAD step 4 Lite";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                break;
        case 0x07:
                device_type = "eQUAD step 4 Gaming";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                workitem.reports_supported |= STD_KEYBOARD;
                break;
        case 0x08:
                device_type = "eQUAD step 4 for gamepads";
                break;
        case 0x0a:
                device_type = "eQUAD nano Lite";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                break;
        case 0x0c:
                device_type = "eQUAD Lightspeed 1";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                workitem.reports_supported |= STD_KEYBOARD;
                break;
        case 0x0d:
                device_type = "eQUAD Lightspeed 1.1";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                workitem.reports_supported |= STD_KEYBOARD;
                break;
        case 0x0f:
        case 0x11:
                device_type = "eQUAD Lightspeed 1.2";
                logi_hidpp_dev_conn_notif_equad(hdev, hidpp_report, &workitem);
                workitem.reports_supported |= STD_KEYBOARD;
                break;
        }

        /* custom receiver device (eg. powerplay) */
        if (hidpp_report->device_index == 7) {
                workitem.reports_supported |= HIDPP;
        }

        if (workitem.type == WORKITEM_TYPE_EMPTY) {
                hid_warn(hdev,
                         "unusable device of type %s (0x%02x) connected on slot %d",
                         device_type,
                         hidpp_report->params[HIDPP_PARAM_PROTO_TYPE],
                         hidpp_report->device_index);
                return;
        }

        hid_info(hdev, "device of type %s (0x%02x) connected on slot %d",
                 device_type, hidpp_report->params[HIDPP_PARAM_PROTO_TYPE],
                 hidpp_report->device_index);

        kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));
        schedule_work(&djrcv_dev->work);
}

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\n");
                        }
                }
        }
}

static void logi_dj_recv_forward_dj(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\n", 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\n");
        }
}

static void logi_dj_recv_forward_report(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\n");
}

static void logi_dj_recv_forward_input_report(struct hid_device *hdev,
                                              u8 *data, int size)
{
        struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
        struct dj_device *dj_dev;
        unsigned long flags;
        u8 report = data[0];
        int i;

        if (report > REPORT_TYPE_RFREPORT_LAST) {
                hid_err(hdev, "Unexpected input report number %d\n", report);
                return;
        }

        spin_lock_irqsave(&djrcv_dev->lock, flags);
        for (i = 0; i < (DJ_MAX_PAIRED_DEVICES + DJ_DEVICE_INDEX_MIN); i++) {
                dj_dev = djrcv_dev->paired_dj_devices[i];
                if (dj_dev && (dj_dev->reports_supported & BIT(report))) {
                        logi_dj_recv_forward_report(dj_dev, data, size);
                        spin_unlock_irqrestore(&djrcv_dev->lock, flags);
                        return;
                }
        }

        logi_dj_recv_queue_unknown_work(djrcv_dev);
        spin_unlock_irqrestore(&djrcv_dev->lock, flags);

        dbg_hid("No dj-devs handling input report number %d\n", report);
}

static int logi_dj_recv_send_report(struct dj_receiver_dev *djrcv_dev,
                                    struct dj_report *dj_report)
{
        struct hid_device *hdev = djrcv_dev->hidpp;
        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) {
                hid_err(hdev, "%s: unable to find dj report\n", __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_hidpp_devices(struct dj_receiver_dev *djrcv_dev)
{
        static const u8 template[] = {
                REPORT_ID_HIDPP_SHORT,
                HIDPP_RECEIVER_INDEX,
                HIDPP_SET_REGISTER,
                HIDPP_REG_CONNECTION_STATE,
                HIDPP_FAKE_DEVICE_ARRIVAL,
                0x00, 0x00
        };
        u8 *hidpp_report;
        int retval;

        hidpp_report = kmemdup(template, sizeof(template), GFP_KERNEL);
        if (!hidpp_report)
                return -ENOMEM;

        retval = hid_hw_raw_request(djrcv_dev->hidpp,
                                    REPORT_ID_HIDPP_SHORT,
                                    hidpp_report, sizeof(template),
                                    HID_OUTPUT_REPORT,
                                    HID_REQ_SET_REPORT);

        kfree(hidpp_report);
        return (retval < 0) ? retval : 0;
}

static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev)
{
        struct dj_report *dj_report;
        int retval;

        djrcv_dev->last_query = jiffies;

        if (djrcv_dev->type != recvr_type_dj)
                return logi_dj_recv_query_hidpp_devices(djrcv_dev);

        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 = HIDPP_RECEIVER_INDEX;
        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->hidpp;
        struct dj_report *dj_report;
        u8 *buf;
        int retval = 0;

        dj_report = kzalloc(sizeof(struct dj_report), GFP_KERNEL);
        if (!dj_report)
                return -ENOMEM;

        if (djrcv_dev->type == recvr_type_dj) {
                dj_report->report_id = REPORT_ID_DJ_SHORT;
                dj_report->device_index = HIDPP_RECEIVER_INDEX;
                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] = HIDPP_RECEIVER_INDEX;
        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\n", __func__, hid->phys);
        return 0;

}

static void logi_dj_ll_close(struct hid_device *hid)
{
        dbg_hid("%s: %s\n", __func__, hid->phys);
}

/*
 * Register 0xB5 is "pairing information". It is solely intended for the
 * receiver, so do not overwrite the device index.
 */
static u8 unifying_pairing_query[]  = { REPORT_ID_HIDPP_SHORT,
                                        HIDPP_RECEIVER_INDEX,
                                        HIDPP_GET_LONG_REGISTER,
                                        HIDPP_REG_PAIRING_INFORMATION };
static u8 unifying_pairing_answer[] = { REPORT_ID_HIDPP_LONG,
                                        HIDPP_RECEIVER_INDEX,
                                        HIDPP_GET_LONG_REGISTER,
                                        HIDPP_REG_PAIRING_INFORMATION };

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

                /* special case where we should not overwrite
                 * the device_index */
                if (count == 7 && !memcmp(buf, unifying_pairing_query,
                                          sizeof(unifying_pairing_query)))
                        buf[4] = (buf[4] & 0xf0) | (djdev->device_index - 1);
                else
                        buf[1] = djdev->device_index;
                return hid_hw_raw_request(djrcv_dev->hidpp, reportnum, buf,
                                count, report_type, reqtype);
        }

        if (buf[0] != REPORT_TYPE_LEDS)
                return -EINVAL;

        if (djrcv_dev->type != recvr_type_dj && count >= 2) {
                if (!djrcv_dev->keyboard) {
                        hid_warn(hid, "Received REPORT_TYPE_LEDS request before the keyboard interface was enumerated\n");
                        return 0;
                }
                /* usbhid overrides the report ID and ignores the first byte */
                return hid_hw_raw_request(djrcv_dev->keyboard, 0, buf, count,
                                          report_type, reqtype);
        }

        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->hidpp, 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\n", __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: %llx\n",
                        __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: %llx\n",
                        __func__, djdev->reports_supported);
                if (djdev->dj_receiver_dev->type == recvr_type_gaming_hidpp ||
                    djdev->dj_receiver_dev->type == recvr_type_mouse_only)
                        rdcat(rdesc, &rsize, mse_high_res_descriptor,
                              sizeof(mse_high_res_descriptor));
                else if (djdev->dj_receiver_dev->type == recvr_type_27mhz)
                        rdcat(rdesc, &rsize, mse_27mhz_descriptor,
                              sizeof(mse_27mhz_descriptor));
                else if (recvr_type_is_bluetooth(djdev->dj_receiver_dev->type))
                        rdcat(rdesc, &rsize, mse_bluetooth_descriptor,
                              sizeof(mse_bluetooth_descriptor));
                else
                        rdcat(rdesc, &rsize, mse_descriptor,
                              sizeof(mse_descriptor));
        }

        if (djdev->reports_supported & KBD_MOUSE) {
                dbg_hid("%s: sending a kbd-mouse descriptor, reports_supported: %llx\n",
                        __func__, djdev->reports_supported);
                rdcat(rdesc, &rsize, mse5_bluetooth_descriptor,
                      sizeof(mse5_bluetooth_descriptor));
        }

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

        if (djdev->reports_supported & HIDPP) {
                dbg_hid("%s: sending a HID++ descriptor, reports_supported: %llx\n",
                        __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\n", __func__);
        return 0;
}

static void logi_dj_ll_stop(struct hid_device *hid)
{
        dbg_hid("%s\n", __func__);
}

static bool logi_dj_ll_may_wakeup(struct hid_device *hid)
{
        struct dj_device *djdev = hid->driver_data;
        struct dj_receiver_dev *djrcv_dev = djdev->dj_receiver_dev;

        return hid_hw_may_wakeup(djrcv_dev->hidpp);
}

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,
        .may_wakeup = logi_dj_ll_may_wakeup,
};

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)
                        hid_err(hdev, "%s: invalid device index:%d\n",
                                __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_dj(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 hidpp_event *hidpp_report = (struct hidpp_event *) data;
        struct dj_device *dj_dev;
        unsigned long flags;
        u8 device_index = hidpp_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_pairing_answer,
                            sizeof(unifying_pairing_answer)))
                        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.
                 */
                hid_err(hdev, "%s: invalid device index:%d\n", __func__,
                        hidpp_report->device_index);
                return false;
        }

        spin_lock_irqsave(&djrcv_dev->lock, flags);

        dj_dev = djrcv_dev->paired_dj_devices[device_index];

        /*
         * With 27 MHz receivers, we do not get an explicit unpair event,
         * remove the old device if the user has paired a *different* device.
         */
        if (djrcv_dev->type == recvr_type_27mhz && dj_dev &&
            hidpp_report->sub_id == REPORT_TYPE_NOTIF_DEVICE_CONNECTED &&
            hidpp_report->params[HIDPP_PARAM_PROTO_TYPE] == 0x02 &&
            hidpp_report->params[HIDPP_PARAM_27MHZ_DEVID] !=
                                                dj_dev->hdev->product) {
                struct dj_workitem workitem = {
                        .device_index = hidpp_report->device_index,
                        .type = WORKITEM_TYPE_UNPAIRED,
                };
                kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));
                /* logi_hidpp_recv_queue_notif will queue the work */
                dj_dev = NULL;
        }

        if (dj_dev) {
                logi_dj_recv_forward_report(dj_dev, data, size);
        } else {
                if (hidpp_report->sub_id == REPORT_TYPE_NOTIF_DEVICE_CONNECTED)
                        logi_hidpp_recv_queue_notif(hdev, hidpp_report);
                else
                        logi_dj_recv_queue_unknown_work(djrcv_dev);
        }

        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)
{
        struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
        dbg_hid("%s, size:%d\n", __func__, size);

        if (!djrcv_dev)
                return 0;

        if (!hdev->report_enum[HID_INPUT_REPORT].numbered) {

                if (djrcv_dev->unnumbered_application == HID_GD_KEYBOARD) {
                        /*
                         * For the keyboard, we can reuse the same report by
                         * using the second byte which is constant in the USB
                         * HID report descriptor.
                         */
                        data[1] = data[0];
                        data[0] = REPORT_TYPE_KEYBOARD;

                        logi_dj_recv_forward_input_report(hdev, data, size);

                        /* restore previous state */
                        data[0] = data[1];
                        data[1] = 0;
                }
                /*
                 * Mouse-only receivers send unnumbered mouse data. The 27 MHz
                 * receiver uses 6 byte packets, the nano receiver 8 bytes.
                 */
                if (djrcv_dev->unnumbered_application == HID_GD_MOUSE &&
                    size <= 8) {
                        u8 mouse_report[9];

                        /* Prepend report id */
                        mouse_report[0] = REPORT_TYPE_MOUSE;
                        memcpy(mouse_report + 1, data, size);
                        logi_dj_recv_forward_input_report(hdev, mouse_report,
                                                          size + 1);
                }

                return false;
        }

        switch (data[0]) {
        case REPORT_ID_DJ_SHORT:
                if (size != DJREPORT_SHORT_LENGTH) {
                        hid_err(hdev, "Short DJ report bad size (%d)", size);
                        return false;
                }
                return logi_dj_dj_event(hdev, report, data, size);
        case REPORT_ID_DJ_LONG:
                if (size != DJREPORT_LONG_LENGTH) {
                        hid_err(hdev, "Long DJ report 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) {
                        hid_err(hdev, "Short HID++ report 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) {
                        hid_err(hdev, "Long HID++ report bad size (%d)", size);
                        return false;
                }
                return logi_dj_hidpp_event(hdev, report, data, size);
        }

        logi_dj_recv_forward_input_report(hdev, data, size);

        return false;
}

static int logi_dj_probe(struct hid_device *hdev,
                         const struct hid_device_id *id)
{
        struct hid_report_enum *rep_enum;
        struct hid_report *rep;
        struct dj_receiver_dev *djrcv_dev;
        struct usb_interface *intf;
        unsigned int no_dj_interfaces = 0;
        bool has_hidpp = false;
        unsigned long flags;
        int retval;

        /*
         * Call to usbhid to fetch the HID descriptors of the current
         * interface subsequently call to the hid/hid-core to parse the
         * fetched descriptors.
         */
        retval = hid_parse(hdev);
        if (retval) {
                hid_err(hdev, "%s: parse failed\n", __func__);
                return retval;
        }

        /*
         * Some KVMs add an extra interface for e.g. mouse emulation. If we
         * treat these as logitech-dj interfaces then this causes input events
         * reported through this extra interface to not be reported correctly.
         * To avoid this, we treat these as generic-hid devices.
         */
        switch (id->driver_data) {
        case recvr_type_dj:             no_dj_interfaces = 3; break;
        case recvr_type_hidpp:          no_dj_interfaces = 2; break;
        case recvr_type_gaming_hidpp:   no_dj_interfaces = 3; break;
        case recvr_type_mouse_only:     no_dj_interfaces = 2; break;
        case recvr_type_27mhz:          no_dj_interfaces = 2; break;
        case recvr_type_bluetooth:      no_dj_interfaces = 2; break;
        case recvr_type_dinovo:         no_dj_interfaces = 2; break;
        }
        if (hid_is_usb(hdev)) {
                intf = to_usb_interface(hdev->dev.parent);
                if (intf && intf->altsetting->desc.bInterfaceNumber >=
                                                        no_dj_interfaces) {
                        hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
                        return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
                }
        }

        rep_enum = &hdev->report_enum[HID_INPUT_REPORT];

        /* no input reports, bail out */
        if (list_empty(&rep_enum->report_list))
                return -ENODEV;

        /*
         * Check for the HID++ application.
         * Note: we should theoretically check for HID++ and DJ
         * collections, but this will do.
         */
        list_for_each_entry(rep, &rep_enum->report_list, list) {
                if (rep->application == 0xff000001)
                        has_hidpp = true;
        }

        /*
         * Ignore interfaces without DJ/HID++ collection, they will not carry
         * any data, dont create any hid_device for them.
         */
        if (!has_hidpp && id->driver_data == recvr_type_dj)
                return -ENODEV;

        /* get the current application attached to the node */
        rep = list_first_entry(&rep_enum->report_list, struct hid_report, list);
        djrcv_dev = dj_get_receiver_dev(hdev, id->driver_data,
                                        rep->application, has_hidpp);
        if (!djrcv_dev) {
                hid_err(hdev, "%s: dj_get_receiver_dev failed\n", __func__);
                return -ENOMEM;
        }

        if (!rep_enum->numbered)
                djrcv_dev->unnumbered_application = rep->application;

        /* Starts the usb device and connects to upper interfaces hiddev and
         * hidraw */
        retval = hid_hw_start(hdev, HID_CONNECT_HIDRAW|HID_CONNECT_HIDDEV);
        if (retval) {
                hid_err(hdev, "%s: hid_hw_start returned error\n", __func__);
                goto hid_hw_start_fail;
        }

        if (has_hidpp) {
                retval = logi_dj_recv_switch_to_dj_mode(djrcv_dev, 0);
                if (retval < 0) {
                        hid_err(hdev, "%s: logi_dj_recv_switch_to_dj_mode returned error:%d\n",
                                __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) {
                hid_err(hdev, "%s: hid_hw_open returned error:%d\n",
                        __func__, retval);
                goto llopen_failed;
        }

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

        if (has_hidpp) {
                spin_lock_irqsave(&djrcv_dev->lock, flags);
                djrcv_dev->ready = true;
                spin_unlock_irqrestore(&djrcv_dev->lock, flags);
                retval = logi_dj_recv_query_paired_devices(djrcv_dev);
                if (retval < 0) {
                        hid_err(hdev, "%s: logi_dj_recv_query_paired_devices error:%d\n",
                                __func__, retval);
                        /*
                         * This can happen with a KVM, let the probe succeed,
                         * logi_dj_recv_queue_unknown_work will retry later.
                         */
                }
        }

        return 0;

llopen_failed:
switch_to_dj_mode_fail:
        hid_hw_stop(hdev);

hid_hw_start_fail:
        dj_put_receiver_dev(hdev);
        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);

        if (!djrcv_dev || djrcv_dev->hidpp != hdev)
                return 0;

        retval = logi_dj_recv_switch_to_dj_mode(djrcv_dev, 0);
        if (retval < 0) {
                hid_err(hdev, "%s: logi_dj_recv_switch_to_dj_mode returned error:%d\n",
                        __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;
        unsigned long flags;
        int i;

        dbg_hid("%s\n", __func__);

        if (!djrcv_dev)
                return hid_hw_stop(hdev);

        /*
         * This ensures that if the work gets requeued from another
         * interface of the same receiver it will be a no-op.
         */
        spin_lock_irqsave(&djrcv_dev->lock, flags);
        djrcv_dev->ready = false;
        spin_unlock_irqrestore(&djrcv_dev->lock, flags);

        cancel_work_sync(&djrcv_dev->work);

        hid_hw_close(hdev);
        hid_hw_stop(hdev);

        /*
         * For proper operation we need access to all interfaces, so we destroy
         * the paired devices when we're unbound from any interface.
         *
         * Note we may still be bound to other interfaces, sharing the same
         * djrcv_dev, so we need locking here.
         */
        for (i = 0; i < (DJ_MAX_PAIRED_DEVICES + DJ_DEVICE_INDEX_MIN); i++) {
                spin_lock_irqsave(&djrcv_dev->lock, flags);
                dj_dev = djrcv_dev->paired_dj_devices[i];
                djrcv_dev->paired_dj_devices[i] = NULL;
                spin_unlock_irqrestore(&djrcv_dev->lock, flags);
                if (dj_dev != NULL) {
                        hid_destroy_device(dj_dev->hdev);
                        kfree(dj_dev);
                }
        }

        dj_put_receiver_dev(hdev);
}

static const struct hid_device_id logi_dj_receivers[] = {
        { /* Logitech unifying receiver (0xc52b) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_UNIFYING_RECEIVER),
         .driver_data = recvr_type_dj},
        { /* Logitech unifying receiver (0xc532) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_UNIFYING_RECEIVER_2),
         .driver_data = recvr_type_dj},

        { /* Logitech Nano mouse only receiver (0xc52f) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                         USB_DEVICE_ID_LOGITECH_NANO_RECEIVER),
         .driver_data = recvr_type_mouse_only},
        { /* Logitech Nano (non DJ) receiver (0xc534) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                         USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_2),
         .driver_data = recvr_type_hidpp},

        { /* Logitech G700(s) receiver (0xc531) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                         USB_DEVICE_ID_LOGITECH_G700_RECEIVER),
         .driver_data = recvr_type_gaming_hidpp},
        { /* Logitech G602 receiver (0xc537) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                0xc537),
         .driver_data = recvr_type_gaming_hidpp},
        { /* Logitech lightspeed receiver (0xc539) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1),
         .driver_data = recvr_type_gaming_hidpp},
        { /* Logitech powerplay receiver (0xc53a) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_POWERPLAY),
         .driver_data = recvr_type_gaming_hidpp},
        { /* Logitech lightspeed receiver (0xc53f) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1_1),
         .driver_data = recvr_type_gaming_hidpp},

        { /* Logitech 27 MHz HID++ 1.0 receiver (0xc513) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_MX3000_RECEIVER),
         .driver_data = recvr_type_27mhz},
        { /* Logitech 27 MHz HID++ 1.0 receiver (0xc517) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_S510_RECEIVER_2),
         .driver_data = recvr_type_27mhz},
        { /* Logitech 27 MHz HID++ 1.0 mouse-only receiver (0xc51b) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_27MHZ_MOUSE_RECEIVER),
         .driver_data = recvr_type_27mhz},

        { /* Logitech MX5000 HID++ / bluetooth receiver keyboard intf. (0xc70e) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_MX5000_RECEIVER_KBD_DEV),
         .driver_data = recvr_type_bluetooth},
        { /* Logitech MX5000 HID++ / bluetooth receiver mouse intf. (0xc70a) */

          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_MX5000_RECEIVER_MOUSE_DEV),
         .driver_data = recvr_type_bluetooth},
        { /* Logitech MX5500 HID++ / bluetooth receiver keyboard intf. (0xc71b) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_MX5500_RECEIVER_KBD_DEV),
         .driver_data = recvr_type_bluetooth},
        { /* Logitech MX5500 HID++ / bluetooth receiver mouse intf. (0xc71c) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_MX5500_RECEIVER_MOUSE_DEV),
         .driver_data = recvr_type_bluetooth},

        { /* Logitech Dinovo Edge HID++ / bluetooth receiver keyboard intf. (0xc713) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_DINOVO_EDGE_RECEIVER_KBD_DEV),
         .driver_data = recvr_type_dinovo},
        { /* Logitech Dinovo Edge HID++ / bluetooth receiver mouse intf. (0xc714) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_DINOVO_EDGE_RECEIVER_MOUSE_DEV),
         .driver_data = recvr_type_dinovo},
        { /* Logitech DiNovo Mini HID++ / bluetooth receiver mouse intf. (0xc71e) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_DINOVO_MINI_RECEIVER_KBD_DEV),
         .driver_data = recvr_type_dinovo},
        { /* Logitech DiNovo Mini HID++ / bluetooth receiver keyboard intf. (0xc71f) */
          HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_DINOVO_MINI_RECEIVER_MOUSE_DEV),
         .driver_data = recvr_type_dinovo},
        {}
};

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");