Staging: hv: delete vmbus_hid_protocol.h

[zen-stable.git] / drivers / staging / hv / hv_mouse.c

/*
 *  Copyright (c) 2009, Citrix Systems, Inc.
 *  Copyright (c) 2010, Microsoft Corporation.
 *  Copyright (c) 2011, Novell Inc.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms and conditions of the GNU General Public License,
 *  version 2, as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 *  more details.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/input.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
#include <linux/pci.h>
#include <linux/dmi.h>

#include "hv_api.h"
#include "logging.h"
#include "version_info.h"
#include "vmbus.h"
#include "vmbus_api.h"
#include "mousevsc_api.h"
#include "channel.h"
#include "vmbus_packet_format.h"


/* The maximum size of a synthetic input message. */
#define SYNTHHID_MAX_INPUT_REPORT_SIZE 16

/*
 * Current version
 *
 * History:
 * Beta, RC < 2008/1/22        1,0
 * RC > 2008/1/22              2,0
 */
#define SYNTHHID_INPUT_VERSION_MAJOR 2
#define SYNTHHID_INPUT_VERSION_MINOR 0
#define SYNTHHID_INPUT_VERSION_DWORD (SYNTHHID_INPUT_VERSION_MINOR | \
    (SYNTHHID_INPUT_VERSION_MAJOR << 16))


#pragma pack(push,1)
/*
 * Message types in the synthetic input protocol
 */
enum synthhid_msg_type {
        SynthHidProtocolRequest,
        SynthHidProtocolResponse,
        SynthHidInitialDeviceInfo,
        SynthHidInitialDeviceInfoAck,
        SynthHidInputReport,
        SynthHidMax
};

/*
 * Basic message structures.
 */
typedef struct {
        enum synthhid_msg_type  Type;    /* Type of the enclosed message */
        u32                     Size;    /* Size of the enclosed message
                                          *  (size of the data payload)
                                          */
} SYNTHHID_MESSAGE_HEADER, *PSYNTHHID_MESSAGE_HEADER;

typedef struct {
        SYNTHHID_MESSAGE_HEADER Header;
        char                    Data[1]; /* Enclosed message */
} SYNTHHID_MESSAGE, *PSYNTHHID_MESSAGE;

typedef union {
        struct {
                u16  Minor;
                u16  Major;
        };

        u32 AsDWord;
} SYNTHHID_VERSION, *PSYNTHHID_VERSION;

/*
 * Protocol messages
 */
typedef struct {
        SYNTHHID_MESSAGE_HEADER Header;
        SYNTHHID_VERSION        VersionRequested;
} SYNTHHID_PROTOCOL_REQUEST, *PSYNTHHID_PROTOCOL_REQUEST;

typedef struct {
        SYNTHHID_MESSAGE_HEADER Header;
        SYNTHHID_VERSION        VersionRequested;
        unsigned char           Approved;
} SYNTHHID_PROTOCOL_RESPONSE, *PSYNTHHID_PROTOCOL_RESPONSE;

typedef struct {
        SYNTHHID_MESSAGE_HEADER     Header;
        struct input_dev_info       HidDeviceAttributes;
        unsigned char               HidDescriptorInformation[1];
} SYNTHHID_DEVICE_INFO, *PSYNTHHID_DEVICE_INFO;

typedef struct {
        SYNTHHID_MESSAGE_HEADER Header;
        unsigned char           Reserved;
} SYNTHHID_DEVICE_INFO_ACK, *PSYNTHHID_DEVICE_INFO_ACK;

typedef struct {
        SYNTHHID_MESSAGE_HEADER Header;
        char                    ReportBuffer[1];
} SYNTHHID_INPUT_REPORT, *PSYNTHHID_INPUT_REPORT;

#pragma pack(pop)


#define NBITS(x) (((x)/BITS_PER_LONG)+1)

enum pipe_prot_msg_type {
        PipeMessageInvalid = 0,
        PipeMessageData,
        PipeMessageMaximum
};


struct pipe_prt_msg {
        enum pipe_prot_msg_type PacketType;
        u32                DataSize;
        char               Data[1];
};

/*
 * Data types
 */
struct  mousevsc_prt_msg {
        enum pipe_prot_msg_type   PacketType;
        u32                  DataSize;
        union {
                SYNTHHID_PROTOCOL_REQUEST       Request;
                SYNTHHID_PROTOCOL_RESPONSE      Response;
                SYNTHHID_DEVICE_INFO_ACK        Ack;
        } u;
};

/*
 * Represents an mousevsc device
 */
struct mousevsc_dev {
        struct hv_device        *Device;
        /* 0 indicates the device is being destroyed */
        atomic_t                RefCount;
        int                     NumOutstandingRequests;
        unsigned char           bInitializeComplete;
        struct mousevsc_prt_msg ProtocolReq;
        struct mousevsc_prt_msg ProtocolResp;
        /* Synchronize the request/response if needed */
        wait_queue_head_t       ProtocolWaitEvent;
        wait_queue_head_t       DeviceInfoWaitEvent;
        int                     protocol_wait_condition;
        int                     device_wait_condition;
        int                     DeviceInfoStatus;

        struct hid_descriptor   *HidDesc;
        unsigned char           *ReportDesc;
        u32                     ReportDescSize;
        struct input_dev_info   DeviceAttr;
};


/*
 * Globals
 */
static const char *gDriverName = "mousevsc";

/* {CFA8B69E-5B4A-4cc0-B98B-8BA1A1F3F95A} */
static const struct hv_guid gMousevscDeviceType = {
        .data = {0x9E, 0xB6, 0xA8, 0xCF, 0x4A, 0x5B, 0xc0, 0x4c,
                 0xB9, 0x8B, 0x8B, 0xA1, 0xA1, 0xF3, 0xF9, 0x5A}
};

/*
 * Internal routines
 */
static int MousevscOnDeviceAdd(struct hv_device *Device, void *AdditionalInfo);

static int MousevscOnDeviceRemove(struct hv_device *Device);

static void MousevscOnCleanup(struct hv_driver *Device);

static void MousevscOnChannelCallback(void *Context);

static int MousevscConnectToVsp(struct hv_device *Device);

static void MousevscOnReceive(struct hv_device *Device,
                              struct vmpacket_descriptor *Packet);

static inline struct mousevsc_dev *AllocInputDevice(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;

        inputDevice = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);

        if (!inputDevice)
                return NULL;

        /*
         * Set to 2 to allow both inbound and outbound traffics
         * (ie GetInputDevice() and MustGetInputDevice()) to proceed.
         */
        atomic_cmpxchg(&inputDevice->RefCount, 0, 2);

        inputDevice->Device = Device;
        Device->ext = inputDevice;

        return inputDevice;
}

static inline void FreeInputDevice(struct mousevsc_dev *Device)
{
        WARN_ON(atomic_read(&Device->RefCount) == 0);
        kfree(Device);
}

/*
 * Get the inputdevice object if exists and its refcount > 1
 */
static inline struct mousevsc_dev *GetInputDevice(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;

        inputDevice = (struct mousevsc_dev *)Device->ext;

/*
 *      FIXME
 *      This sure isn't a valid thing to print for debugging, no matter
 *      what the intention is...
 *
 *      printk(KERN_ERR "-------------------------> REFCOUNT = %d",
 *             inputDevice->RefCount);
 */

        if (inputDevice && atomic_read(&inputDevice->RefCount) > 1)
                atomic_inc(&inputDevice->RefCount);
        else
                inputDevice = NULL;

        return inputDevice;
}

/*
 * Get the inputdevice object iff exists and its refcount > 0
 */
static inline struct mousevsc_dev *MustGetInputDevice(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;

        inputDevice = (struct mousevsc_dev *)Device->ext;

        if (inputDevice && atomic_read(&inputDevice->RefCount))
                atomic_inc(&inputDevice->RefCount);
        else
                inputDevice = NULL;

        return inputDevice;
}

static inline void PutInputDevice(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;

        inputDevice = (struct mousevsc_dev *)Device->ext;

        atomic_dec(&inputDevice->RefCount);
}

/*
 * Drop ref count to 1 to effectively disable GetInputDevice()
 */
static inline struct mousevsc_dev *ReleaseInputDevice(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;

        inputDevice = (struct mousevsc_dev *)Device->ext;

        /* Busy wait until the ref drop to 2, then set it to 1  */
        while (atomic_cmpxchg(&inputDevice->RefCount, 2, 1) != 2)
                udelay(100);

        return inputDevice;
}

/*
 * Drop ref count to 0. No one can use InputDevice object.
 */
static inline struct mousevsc_dev *FinalReleaseInputDevice(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;

        inputDevice = (struct mousevsc_dev *)Device->ext;

        /* Busy wait until the ref drop to 1, then set it to 0  */
        while (atomic_cmpxchg(&inputDevice->RefCount, 1, 0) != 1)
                udelay(100);

        Device->ext = NULL;
        return inputDevice;
}

/*
 *
 * Name:
 *      MousevscInitialize()
 *
 * Description:
 *      Main entry point
 *
 */
int mouse_vsc_initialize(struct hv_driver *Driver)
{
        struct mousevsc_drv_obj *inputDriver =
                (struct mousevsc_drv_obj *)Driver;
        int ret = 0;

        Driver->name = gDriverName;
        memcpy(&Driver->dev_type, &gMousevscDeviceType,
               sizeof(struct hv_guid));

        /* Setup the dispatch table */
        inputDriver->Base.dev_add               = MousevscOnDeviceAdd;
        inputDriver->Base.dev_rm = MousevscOnDeviceRemove;
        inputDriver->Base.cleanup               = MousevscOnCleanup;

        inputDriver->OnOpen                     = NULL;
        inputDriver->OnClose                    = NULL;

        return ret;
}

/*
 *
 * Name:
 *      MousevscOnDeviceAdd()
 *
 * Description:
 *      Callback when the device belonging to this driver is added
 *
 */
int
MousevscOnDeviceAdd(struct hv_device *Device, void *AdditionalInfo)
{
        int ret = 0;
        struct mousevsc_dev *inputDevice;
        struct mousevsc_drv_obj *inputDriver;
        struct input_dev_info deviceInfo;

        inputDevice = AllocInputDevice(Device);

        if (!inputDevice) {
                ret = -1;
                goto Cleanup;
        }

        inputDevice->bInitializeComplete = false;

        /* Open the channel */
        ret = vmbus_open(Device->channel,
                INPUTVSC_SEND_RING_BUFFER_SIZE,
                INPUTVSC_RECV_RING_BUFFER_SIZE,
                NULL,
                0,
                MousevscOnChannelCallback,
                Device
                );

        if (ret != 0) {
                pr_err("unable to open channel: %d", ret);
                return -1;
        }

        pr_info("InputVsc channel open: %d", ret);

        ret = MousevscConnectToVsp(Device);

        if (ret != 0) {
                pr_err("unable to connect channel: %d", ret);

                vmbus_close(Device->channel);
                return ret;
        }

        inputDriver = (struct mousevsc_drv_obj *)inputDevice->Device->drv;

        deviceInfo.VendorID = inputDevice->DeviceAttr.VendorID;
        deviceInfo.ProductID = inputDevice->DeviceAttr.ProductID;
        deviceInfo.VersionNumber = inputDevice->DeviceAttr.VersionNumber;
        strcpy(deviceInfo.Name, "Microsoft Vmbus HID-compliant Mouse");

        /* Send the device info back up */
        inputDriver->OnDeviceInfo(Device, &deviceInfo);

        /* Send the report desc back up */
        /* workaround SA-167 */
        if (inputDevice->ReportDesc[14] == 0x25)
                inputDevice->ReportDesc[14] = 0x29;

        inputDriver->OnReportDescriptor(Device, inputDevice->ReportDesc, inputDevice->ReportDescSize);

        inputDevice->bInitializeComplete = true;

Cleanup:
        return ret;
}

int
MousevscConnectToVsp(struct hv_device *Device)
{
        int ret = 0;
        struct mousevsc_dev *inputDevice;
        struct mousevsc_prt_msg *request;
        struct mousevsc_prt_msg *response;

        inputDevice = GetInputDevice(Device);

        if (!inputDevice) {
                pr_err("unable to get input device...device being destroyed?");
                return -1;
        }

        init_waitqueue_head(&inputDevice->ProtocolWaitEvent);
        init_waitqueue_head(&inputDevice->DeviceInfoWaitEvent);

        request = &inputDevice->ProtocolReq;

        /*
         * Now, initiate the vsc/vsp initialization protocol on the open channel
         */
        memset(request, sizeof(struct mousevsc_prt_msg), 0);

        request->PacketType = PipeMessageData;
        request->DataSize = sizeof(SYNTHHID_PROTOCOL_REQUEST);

        request->u.Request.Header.Type = SynthHidProtocolRequest;
        request->u.Request.Header.Size = sizeof(unsigned long);
        request->u.Request.VersionRequested.AsDWord =
                SYNTHHID_INPUT_VERSION_DWORD;

        pr_info("SYNTHHID_PROTOCOL_REQUEST...");

        ret = vmbus_sendpacket(Device->channel, request,
                                        sizeof(struct pipe_prt_msg) -
                                        sizeof(unsigned char) +
                                        sizeof(SYNTHHID_PROTOCOL_REQUEST),
                                        (unsigned long)request,
                                        VM_PKT_DATA_INBAND,
                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
        if (ret != 0) {
                pr_err("unable to send SYNTHHID_PROTOCOL_REQUEST");
                goto Cleanup;
        }

        inputDevice->protocol_wait_condition = 0;
        wait_event_timeout(inputDevice->ProtocolWaitEvent, inputDevice->protocol_wait_condition, msecs_to_jiffies(1000));
        if (inputDevice->protocol_wait_condition == 0) {
                ret = -ETIMEDOUT;
                goto Cleanup;
        }

        response = &inputDevice->ProtocolResp;

        if (!response->u.Response.Approved) {
                pr_err("SYNTHHID_PROTOCOL_REQUEST failed (version %d)",
                       SYNTHHID_INPUT_VERSION_DWORD);
                ret = -1;
                goto Cleanup;
        }

        inputDevice->device_wait_condition = 0;
        wait_event_timeout(inputDevice->DeviceInfoWaitEvent, inputDevice->device_wait_condition, msecs_to_jiffies(1000));
        if (inputDevice->device_wait_condition == 0) {
                ret = -ETIMEDOUT;
                goto Cleanup;
        }

        /*
         * We should have gotten the device attr, hid desc and report
         * desc at this point
         */
        if (!inputDevice->DeviceInfoStatus)
                pr_info("**** input channel up and running!! ****");
        else
                ret = -1;

Cleanup:
        PutInputDevice(Device);

        return ret;
}


/*
 *
 * Name:
 *      MousevscOnDeviceRemove()
 *
 * Description:
 *      Callback when the our device is being removed
 *
 */
int
MousevscOnDeviceRemove(struct hv_device *Device)
{
        struct mousevsc_dev *inputDevice;
        int ret = 0;

        pr_info("disabling input device (%p)...",
                    Device->ext);

        inputDevice = ReleaseInputDevice(Device);


        /*
         * At this point, all outbound traffic should be disable. We only
         * allow inbound traffic (responses) to proceed
         *
         * so that outstanding requests can be completed.
         */
        while (inputDevice->NumOutstandingRequests) {
                pr_info("waiting for %d requests to complete...", inputDevice->NumOutstandingRequests);

                udelay(100);
        }

        pr_info("removing input device (%p)...", Device->ext);

        inputDevice = FinalReleaseInputDevice(Device);

        pr_info("input device (%p) safe to remove", inputDevice);

        /* Close the channel */
        vmbus_close(Device->channel);

        FreeInputDevice(inputDevice);

        return ret;
}


/*
 *
 * Name:
 *      MousevscOnCleanup()
 *
 * Description:
 *      Perform any cleanup when the driver is removed
 */
static void MousevscOnCleanup(struct hv_driver *drv)
{
}


static void
MousevscOnSendCompletion(struct hv_device *Device,
                         struct vmpacket_descriptor *Packet)
{
        struct mousevsc_dev *inputDevice;
        void *request;

        inputDevice = MustGetInputDevice(Device);
        if (!inputDevice) {
                pr_err("unable to get input device...device being destroyed?");
                return;
        }

        request = (void *)(unsigned long *)Packet->trans_id;

        if (request == &inputDevice->ProtocolReq) {
                /* FIXME */
                /* Shouldn't we be doing something here? */
        }

        PutInputDevice(Device);
}

void
MousevscOnReceiveDeviceInfo(
        struct mousevsc_dev *InputDevice,
        SYNTHHID_DEVICE_INFO *DeviceInfo)
{
        int ret = 0;
        struct hid_descriptor *desc;
        struct mousevsc_prt_msg ack;

        /* Assume success for now */
        InputDevice->DeviceInfoStatus = 0;

        /* Save the device attr */
        memcpy(&InputDevice->DeviceAttr, &DeviceInfo->HidDeviceAttributes, sizeof(struct input_dev_info));

        /* Save the hid desc */
        desc = (struct hid_descriptor *)DeviceInfo->HidDescriptorInformation;
        WARN_ON(desc->bLength > 0);

        InputDevice->HidDesc = kzalloc(desc->bLength, GFP_KERNEL);

        if (!InputDevice->HidDesc) {
                pr_err("unable to allocate hid descriptor - size %d", desc->bLength);
                goto Cleanup;
        }

        memcpy(InputDevice->HidDesc, desc, desc->bLength);

        /* Save the report desc */
        InputDevice->ReportDescSize = desc->desc[0].wDescriptorLength;
        InputDevice->ReportDesc = kzalloc(InputDevice->ReportDescSize,
                                          GFP_KERNEL);

        if (!InputDevice->ReportDesc) {
                pr_err("unable to allocate report descriptor - size %d",
                           InputDevice->ReportDescSize);
                goto Cleanup;
        }

        memcpy(InputDevice->ReportDesc,
               ((unsigned char *)desc) + desc->bLength,
               desc->desc[0].wDescriptorLength);

        /* Send the ack */
        memset(&ack, sizeof(struct mousevsc_prt_msg), 0);

        ack.PacketType = PipeMessageData;
        ack.DataSize = sizeof(SYNTHHID_DEVICE_INFO_ACK);

        ack.u.Ack.Header.Type = SynthHidInitialDeviceInfoAck;
        ack.u.Ack.Header.Size = 1;
        ack.u.Ack.Reserved = 0;

        ret = vmbus_sendpacket(InputDevice->Device->channel,
                        &ack,
                        sizeof(struct pipe_prt_msg) - sizeof(unsigned char) + sizeof(SYNTHHID_DEVICE_INFO_ACK),
                        (unsigned long)&ack,
                        VM_PKT_DATA_INBAND,
                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
        if (ret != 0) {
                pr_err("unable to send SYNTHHID_DEVICE_INFO_ACK - ret %d",
                           ret);
                goto Cleanup;
        }

        InputDevice->device_wait_condition = 1;
        wake_up(&InputDevice->DeviceInfoWaitEvent);

        return;

Cleanup:
        if (InputDevice->HidDesc) {
                kfree(InputDevice->HidDesc);
                InputDevice->HidDesc = NULL;
        }

        if (InputDevice->ReportDesc) {
                kfree(InputDevice->ReportDesc);
                InputDevice->ReportDesc = NULL;
        }

        InputDevice->DeviceInfoStatus = -1;
        InputDevice->device_wait_condition = 1;
        wake_up(&InputDevice->DeviceInfoWaitEvent);
}


void
MousevscOnReceiveInputReport(
        struct mousevsc_dev *InputDevice,
        SYNTHHID_INPUT_REPORT *InputReport)
{
        struct mousevsc_drv_obj *inputDriver;

        if (!InputDevice->bInitializeComplete) {
                pr_info("Initialization incomplete...ignoring InputReport msg");
                return;
        }

        inputDriver = (struct mousevsc_drv_obj *)InputDevice->Device->drv;

        inputDriver->OnInputReport(InputDevice->Device,
                                   InputReport->ReportBuffer,
                                   InputReport->Header.Size);
}

void
MousevscOnReceive(struct hv_device *Device, struct vmpacket_descriptor *Packet)
{
        struct pipe_prt_msg *pipeMsg;
        SYNTHHID_MESSAGE *hidMsg;
        struct mousevsc_dev *inputDevice;

        inputDevice = MustGetInputDevice(Device);
        if (!inputDevice) {
                pr_err("unable to get input device...device being destroyed?");
                return;
        }

        pipeMsg = (struct pipe_prt_msg *)((unsigned long)Packet + (Packet->offset8 << 3));

        if (pipeMsg->PacketType != PipeMessageData) {
                pr_err("unknown pipe msg type - type %d len %d",
                           pipeMsg->PacketType, pipeMsg->DataSize);
                PutInputDevice(Device);
                return ;
        }

        hidMsg = (SYNTHHID_MESSAGE *)&pipeMsg->Data[0];

        switch (hidMsg->Header.Type) {
        case SynthHidProtocolResponse:
                memcpy(&inputDevice->ProtocolResp, pipeMsg, pipeMsg->DataSize+sizeof(struct pipe_prt_msg) - sizeof(unsigned char));
                inputDevice->protocol_wait_condition = 1;
                wake_up(&inputDevice->ProtocolWaitEvent);
                break;

        case SynthHidInitialDeviceInfo:
                WARN_ON(pipeMsg->DataSize >= sizeof(struct input_dev_info));

                /*
                 * Parse out the device info into device attr,
                 * hid desc and report desc
                 */
                MousevscOnReceiveDeviceInfo(inputDevice,
                                            (SYNTHHID_DEVICE_INFO *)&pipeMsg->Data[0]);
                break;
        case SynthHidInputReport:
                MousevscOnReceiveInputReport(inputDevice,
                                             (SYNTHHID_INPUT_REPORT *)&pipeMsg->Data[0]);

                break;
        default:
                pr_err("unsupported hid msg type - type %d len %d",
                       hidMsg->Header.Type, hidMsg->Header.Size);
                break;
        }

        PutInputDevice(Device);
}

void MousevscOnChannelCallback(void *Context)
{
        const int packetSize = 0x100;
        int ret = 0;
        struct hv_device *device = (struct hv_device *)Context;
        struct mousevsc_dev *inputDevice;

        u32 bytesRecvd;
        u64 requestId;
        unsigned char packet[packetSize];
        struct vmpacket_descriptor *desc;
        unsigned char   *buffer = packet;
        int     bufferlen = packetSize;

        inputDevice = MustGetInputDevice(device);

        if (!inputDevice) {
                pr_err("unable to get input device...device being destroyed?");
                return;
        }

        do {
                ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen, &bytesRecvd, &requestId);

                if (ret == 0) {
                        if (bytesRecvd > 0) {
                                desc = (struct vmpacket_descriptor *)buffer;

                                switch (desc->type) {
                                        case VM_PKT_COMP:
                                                MousevscOnSendCompletion(device,
                                                                         desc);
                                                break;

                                        case VM_PKT_DATA_INBAND:
                                                MousevscOnReceive(device, desc);
                                                break;

                                        default:
                                                pr_err("unhandled packet type %d, tid %llx len %d\n",
                                                           desc->type,
                                                           requestId,
                                                           bytesRecvd);
                                                break;
                                }

                                /* reset */
                                if (bufferlen > packetSize) {
                                        kfree(buffer);

                                        buffer = packet;
                                        bufferlen = packetSize;
                                }
                        } else {
                                /*
                                 * pr_debug("nothing else to read...");
                                 * reset
                                 */
                                if (bufferlen > packetSize) {
                                        kfree(buffer);

                                        buffer = packet;
                                        bufferlen = packetSize;
                                }
                                break;
                        }
                } else if (ret == -2) {
                        /* Handle large packet */
                        bufferlen = bytesRecvd;
                        buffer = kzalloc(bytesRecvd, GFP_KERNEL);

                        if (buffer == NULL) {
                                buffer = packet;
                                bufferlen = packetSize;

                                /* Try again next time around */
                                pr_err("unable to allocate buffer of size %d!",
                                       bytesRecvd);
                                break;
                        }
                }
        } while (1);

        PutInputDevice(device);

        return;
}

/*
 * Data types
 */
struct input_device_context {
        struct vm_device        *device_ctx;
        struct hid_device       *hid_device;
        struct input_dev_info   device_info;
        int                     connected;
};

struct mousevsc_driver_context {
        struct driver_context   drv_ctx;
        struct mousevsc_drv_obj drv_obj;
};

static struct mousevsc_driver_context g_mousevsc_drv;

void mousevsc_deviceinfo_callback(struct hv_device *dev,
                                  struct input_dev_info *info)
{
        struct vm_device *device_ctx = to_vm_device(dev);
        struct input_device_context *input_device_ctx =
                dev_get_drvdata(&device_ctx->device);

        memcpy(&input_device_ctx->device_info, info,
               sizeof(struct input_dev_info));

        DPRINT_INFO(INPUTVSC_DRV, "mousevsc_deviceinfo_callback()");
}

void mousevsc_inputreport_callback(struct hv_device *dev, void *packet, u32 len)
{
        int ret = 0;

        struct vm_device *device_ctx = to_vm_device(dev);
        struct input_device_context *input_dev_ctx =
                dev_get_drvdata(&device_ctx->device);

        ret = hid_input_report(input_dev_ctx->hid_device,
                              HID_INPUT_REPORT, packet, len, 1);

        DPRINT_DBG(INPUTVSC_DRV, "hid_input_report (ret %d)", ret);
}

int mousevsc_hid_open(struct hid_device *hid)
{
        return 0;
}

void mousevsc_hid_close(struct hid_device *hid)
{
}

int mousevsc_probe(struct device *device)
{
        int ret = 0;

        struct driver_context *driver_ctx =
                driver_to_driver_context(device->driver);
        struct mousevsc_driver_context *mousevsc_drv_ctx =
                (struct mousevsc_driver_context *)driver_ctx;
        struct mousevsc_drv_obj *mousevsc_drv_obj = &mousevsc_drv_ctx->drv_obj;

        struct vm_device *device_ctx = device_to_vm_device(device);
        struct hv_device *device_obj = &device_ctx->device_obj;
        struct input_device_context *input_dev_ctx;

        input_dev_ctx = kmalloc(sizeof(struct input_device_context),
                                GFP_KERNEL);

        dev_set_drvdata(device, input_dev_ctx);

        /* Call to the vsc driver to add the device */
        ret = mousevsc_drv_obj->Base.dev_add(device_obj, NULL);

        if (ret != 0) {
                DPRINT_ERR(INPUTVSC_DRV, "unable to add input vsc device");

                return -1;
        }

        return 0;
}


int mousevsc_remove(struct device *device)
{
        int ret = 0;

        struct driver_context *driver_ctx =
                driver_to_driver_context(device->driver);
        struct mousevsc_driver_context *mousevsc_drv_ctx =
                (struct mousevsc_driver_context *)driver_ctx;
        struct mousevsc_drv_obj *mousevsc_drv_obj = &mousevsc_drv_ctx->drv_obj;

        struct vm_device *device_ctx = device_to_vm_device(device);
        struct hv_device *device_obj = &device_ctx->device_obj;
        struct input_device_context *input_dev_ctx;

        input_dev_ctx = kmalloc(sizeof(struct input_device_context),
                                GFP_KERNEL);

        dev_set_drvdata(device, input_dev_ctx);

        if (input_dev_ctx->connected) {
                hidinput_disconnect(input_dev_ctx->hid_device);
                input_dev_ctx->connected = 0;
        }

        if (!mousevsc_drv_obj->Base.dev_rm)
                return -1;

        /*
         * Call to the vsc driver to let it know that the device
         * is being removed
         */
        ret = mousevsc_drv_obj->Base.dev_rm(device_obj);

        if (ret != 0) {
                DPRINT_ERR(INPUTVSC_DRV,
                           "unable to remove vsc device (ret %d)", ret);
        }

        kfree(input_dev_ctx);

        return ret;
}

void mousevsc_reportdesc_callback(struct hv_device *dev, void *packet, u32 len)
{
        struct vm_device *device_ctx = to_vm_device(dev);
        struct input_device_context *input_device_ctx =
                dev_get_drvdata(&device_ctx->device);
        struct hid_device *hid_dev;

        /* hid_debug = -1; */
        hid_dev = kmalloc(sizeof(struct hid_device), GFP_KERNEL);

        if (hid_parse_report(hid_dev, packet, len)) {
                DPRINT_INFO(INPUTVSC_DRV, "Unable to call hd_parse_report");
                return;
        }

        if (hid_dev) {
                DPRINT_INFO(INPUTVSC_DRV, "hid_device created");

                hid_dev->ll_driver->open  = mousevsc_hid_open;
                hid_dev->ll_driver->close = mousevsc_hid_close;

                hid_dev->bus =  0x06;  /* BUS_VIRTUAL */
                hid_dev->vendor = input_device_ctx->device_info.VendorID;
                hid_dev->product = input_device_ctx->device_info.ProductID;
                hid_dev->version = input_device_ctx->device_info.VersionNumber;
                hid_dev->dev = device_ctx->device;

                sprintf(hid_dev->name, "%s",
                        input_device_ctx->device_info.Name);

                /*
                 * HJ Do we want to call it with a 0
                 */
                if (!hidinput_connect(hid_dev, 0)) {
                        hid_dev->claimed |= HID_CLAIMED_INPUT;

                        input_device_ctx->connected = 1;

                        DPRINT_INFO(INPUTVSC_DRV,
                                     "HID device claimed by input\n");
                }

                if (!hid_dev->claimed) {
                        DPRINT_ERR(INPUTVSC_DRV,
                                    "HID device not claimed by "
                                    "input or hiddev\n");
                }

                input_device_ctx->hid_device = hid_dev;
        }

        kfree(hid_dev);
}

/*
 *
 * Name:        mousevsc_drv_init()
 *
 * Desc:        Driver initialization.
 */
int mousevsc_drv_init(int (*pfn_drv_init)(struct hv_driver *pfn_drv_init))
{
        int ret = 0;
        struct mousevsc_drv_obj *input_drv_obj = &g_mousevsc_drv.drv_obj;
        struct driver_context *drv_ctx = &g_mousevsc_drv.drv_ctx;

        input_drv_obj->OnDeviceInfo = mousevsc_deviceinfo_callback;
        input_drv_obj->OnInputReport = mousevsc_inputreport_callback;
        input_drv_obj->OnReportDescriptor = mousevsc_reportdesc_callback;

        /* Callback to client driver to complete the initialization */
        pfn_drv_init(&input_drv_obj->Base);

        drv_ctx->driver.name = input_drv_obj->Base.name;
        memcpy(&drv_ctx->class_id, &input_drv_obj->Base.dev_type,
               sizeof(struct hv_guid));

        drv_ctx->probe = mousevsc_probe;
        drv_ctx->remove = mousevsc_remove;

        /* The driver belongs to vmbus */
        vmbus_child_driver_register(drv_ctx);

        return ret;
}


int mousevsc_drv_exit_cb(struct device *dev, void *data)
{
        struct device **curr = (struct device **)data;
        *curr = dev;

        return 1;
}

void mousevsc_drv_exit(void)
{
        struct mousevsc_drv_obj *mousevsc_drv_obj = &g_mousevsc_drv.drv_obj;
        struct driver_context *drv_ctx = &g_mousevsc_drv.drv_ctx;
        int ret;

        struct device *current_dev = NULL;

        while (1) {
                current_dev = NULL;

                /* Get the device */
                ret = driver_for_each_device(&drv_ctx->driver, NULL,
                                             (void *)&current_dev,
                                             mousevsc_drv_exit_cb);
                if (ret)
                        printk(KERN_ERR "Can't find mouse device!\n");

                if (current_dev == NULL)
                        break;

                /* Initiate removal from the top-down */
                device_unregister(current_dev);
        }

        if (mousevsc_drv_obj->Base.cleanup)
                mousevsc_drv_obj->Base.cleanup(&mousevsc_drv_obj->Base);

        vmbus_child_driver_unregister(drv_ctx);

        return;
}

static int __init mousevsc_init(void)
{
        int ret;

        DPRINT_INFO(INPUTVSC_DRV, "Hyper-V Mouse driver initializing.");

        ret = mousevsc_drv_init(mouse_vsc_initialize);

        return ret;
}

static void __exit mousevsc_exit(void)
{
        mousevsc_drv_exit();
}

/*
 * We don't want to automatically load this driver just yet, it's quite
 * broken.  It's safe if you want to load it yourself manually, but
 * don't inflict it on unsuspecting users, that's just mean.
 */
#if 0

/*
 * We use a PCI table to determine if we should autoload this driver  This is
 * needed by distro tools to determine if the hyperv drivers should be
 * installed and/or configured.  We don't do anything else with the table, but
 * it needs to be present.
 */
const static struct pci_device_id microsoft_hv_pci_table[] = {
        { PCI_DEVICE(0x1414, 0x5353) }, /* VGA compatible controller */
        { 0 }
};
MODULE_DEVICE_TABLE(pci, microsoft_hv_pci_table);
#endif

MODULE_LICENSE("GPL");
MODULE_VERSION(HV_DRV_VERSION);
module_init(mousevsc_init);
module_exit(mousevsc_exit);