openwrt-xburst/target/linux/s3c24xx/files-2.6.30/drivers/ar6000/hif/hif.c

/*
 * @file: hif.c
 *
 * @abstract: HIF layer reference implementation for Atheros SDIO stack
 *
 * @notice: Copyright (c) 2004-2006 Atheros Communications Inc.
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation;
 *
 *  Software distributed under the License is distributed on an "AS
 *  IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 *  implied. See the License for the specific language governing
 *  rights and limitations under the License.
 *
 *
 *
 */

#include "hif_internal.h"

/* ------ Static Variables ------ */

/* ------ Global Variable Declarations ------- */
SD_PNP_INFO Ids[] = {
    {
        .SDIO_ManufacturerID = MANUFACTURER_ID_AR6001_BASE | 0xB,
        .SDIO_ManufacturerCode = MANUFACTURER_CODE,
        .SDIO_FunctionClass = FUNCTION_CLASS,
        .SDIO_FunctionNo = 1
    },
    {
        .SDIO_ManufacturerID = MANUFACTURER_ID_AR6001_BASE | 0xA,
        .SDIO_ManufacturerCode = MANUFACTURER_CODE,
        .SDIO_FunctionClass = FUNCTION_CLASS,
        .SDIO_FunctionNo = 1
    },
    {
        .SDIO_ManufacturerID = MANUFACTURER_ID_AR6001_BASE | 0x9,
        .SDIO_ManufacturerCode = MANUFACTURER_CODE,
        .SDIO_FunctionClass = FUNCTION_CLASS,
        .SDIO_FunctionNo = 1
    },
    {
        .SDIO_ManufacturerID = MANUFACTURER_ID_AR6001_BASE | 0x8,
        .SDIO_ManufacturerCode = MANUFACTURER_CODE,
        .SDIO_FunctionClass = FUNCTION_CLASS,
        .SDIO_FunctionNo = 1
    },
    {
        .SDIO_ManufacturerID = MANUFACTURER_ID_AR6002_BASE | 0x0,
        .SDIO_ManufacturerCode = MANUFACTURER_CODE,
        .SDIO_FunctionClass = FUNCTION_CLASS,
        .SDIO_FunctionNo = 1
    },
    {
        .SDIO_ManufacturerID = MANUFACTURER_ID_AR6002_BASE | 0x1,
        .SDIO_ManufacturerCode = MANUFACTURER_CODE,
        .SDIO_FunctionClass = FUNCTION_CLASS,
        .SDIO_FunctionNo = 1
    },
    {
    }                      //list is null termintaed
};

TARGET_FUNCTION_CONTEXT FunctionContext = {
    .function.Version    = CT_SDIO_STACK_VERSION_CODE,
    .function.pName      = "sdio_wlan",
    .function.MaxDevices = 1,
    .function.NumDevices = 0,
    .function.pIds       = Ids,
    .function.pProbe     = hifDeviceInserted,
    .function.pRemove    = hifDeviceRemoved,
    .function.pSuspend   = NULL,
    .function.pResume    = NULL,
    .function.pWake      = NULL,
    .function.pContext   = &FunctionContext,
};

HIF_DEVICE hifDevice[HIF_MAX_DEVICES];
HTC_CALLBACKS htcCallbacks;
BUS_REQUEST busRequest[BUS_REQUEST_MAX_NUM];
static BUS_REQUEST *s_busRequestFreeQueue = NULL;
OS_CRITICALSECTION lock;
extern A_UINT32 onebitmode;
extern A_UINT32 busspeedlow;

#ifdef DEBUG
extern A_UINT32 debughif;
#define ATH_DEBUG_ERROR 1
#define ATH_DEBUG_WARN  2
#define ATH_DEBUG_TRACE 3
#define _AR_DEBUG_PRINTX_ARG(arg...) arg
#define AR_DEBUG_PRINTF(lvl, args)\
    {if (lvl <= debughif)\
        A_PRINTF(KERN_ALERT _AR_DEBUG_PRINTX_ARG args);\
    }
#else
#define AR_DEBUG_PRINTF(lvl, args)
#endif

static BUS_REQUEST *hifAllocateBusRequest(void);
static void hifFreeBusRequest(BUS_REQUEST *busrequest);
static THREAD_RETURN insert_helper_func(POSKERNEL_HELPER pHelper);
static void ResetAllCards(void);

/* ------ Functions ------ */
int HIFInit(HTC_CALLBACKS *callbacks)
{
    SDIO_STATUS status;
    DBG_ASSERT(callbacks != NULL);

    /* Store the callback and event handlers */
    htcCallbacks.deviceInsertedHandler = callbacks->deviceInsertedHandler;
    htcCallbacks.deviceRemovedHandler = callbacks->deviceRemovedHandler;
    htcCallbacks.deviceSuspendHandler = callbacks->deviceSuspendHandler;
    htcCallbacks.deviceResumeHandler = callbacks->deviceResumeHandler;
    htcCallbacks.deviceWakeupHandler = callbacks->deviceWakeupHandler;
    htcCallbacks.rwCompletionHandler = callbacks->rwCompletionHandler;
    htcCallbacks.dsrHandler = callbacks->dsrHandler;

    CriticalSectionInit(&lock);

    /* Register with bus driver core */
    status = SDIO_RegisterFunction(&FunctionContext.function);
    DBG_ASSERT(SDIO_SUCCESS(status));

    return(0);
}

A_STATUS
HIFReadWrite(HIF_DEVICE *device,
             A_UINT32 address,
             A_UCHAR *buffer,
             A_UINT32 length,
             A_UINT32 request,
             void *context)
{
    A_UINT8 rw;
    A_UINT8 mode;
    A_UINT8 funcNo;
    A_UINT8 opcode;
    A_UINT16 count;
    SDREQUEST *sdrequest;
    SDIO_STATUS sdiostatus;
    BUS_REQUEST *busrequest;
    A_STATUS    status = A_OK;

    DBG_ASSERT(device != NULL);
    DBG_ASSERT(device->handle != NULL);

    AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Device: %p\n", device));

    do {
        busrequest = hifAllocateBusRequest();
        if (busrequest == NULL) {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR, ("HIF Unable to allocate bus request\n"));
            status = A_NO_RESOURCE;
            break;
        }

        sdrequest = busrequest->request;
        busrequest->context = context;

        sdrequest->pDataBuffer = buffer;
        if (request & HIF_SYNCHRONOUS) {
            sdrequest->Flags = SDREQ_FLAGS_RESP_SDIO_R5 | SDREQ_FLAGS_DATA_TRANS;
            sdrequest->pCompleteContext = NULL;
            sdrequest->pCompletion = NULL;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Execution mode: Synchronous\n"));
        } else if (request & HIF_ASYNCHRONOUS) {
            sdrequest->Flags = SDREQ_FLAGS_RESP_SDIO_R5 | SDREQ_FLAGS_DATA_TRANS |
                               SDREQ_FLAGS_TRANS_ASYNC;
            sdrequest->pCompleteContext = busrequest;
            sdrequest->pCompletion = hifRWCompletionHandler;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Execution mode: Asynchronous\n"));
        } else {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Invalid execution mode: 0x%08x\n", request));
            status = A_EINVAL;
            break;
        }

        if (request & HIF_EXTENDED_IO) {
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Command type: CMD53\n"));
            sdrequest->Command = CMD53;
        } else {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Invalid command type: 0x%08x\n", request));
            status = A_EINVAL;
            break;
        }

        if (request & HIF_BLOCK_BASIS) {
            mode = CMD53_BLOCK_BASIS;
            sdrequest->BlockLen = HIF_MBOX_BLOCK_SIZE;
            sdrequest->BlockCount = length / HIF_MBOX_BLOCK_SIZE;
            count = sdrequest->BlockCount;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                            ("Block mode (BlockLen: %d, BlockCount: %d)\n",
                            sdrequest->BlockLen, sdrequest->BlockCount));
        } else if (request & HIF_BYTE_BASIS) {
            mode = CMD53_BYTE_BASIS;
            sdrequest->BlockLen = length;
            sdrequest->BlockCount = 1;
            count = sdrequest->BlockLen;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                            ("Byte mode (BlockLen: %d, BlockCount: %d)\n",
                            sdrequest->BlockLen, sdrequest->BlockCount));
        } else {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Invalid data mode: 0x%08x\n", request));
            status = A_EINVAL;
            break;
        }

#if 0
        /* useful for checking register accesses */
        if (length & 0x3) {
            A_PRINTF(KERN_ALERT"HIF (%s) is not a multiple of 4 bytes, addr:0x%X, len:%d\n",
                                request & HIF_WRITE ? "write":"read", address, length);
        }
#endif

        if ((address >= HIF_MBOX_START_ADDR(0)) &&
            (address <= HIF_MBOX_END_ADDR(3)))
        {

            DBG_ASSERT(length <= HIF_MBOX_WIDTH);

            /*
             * Mailbox write. Adjust the address so that the last byte
             * falls on the EOM address.
             */
            address += (HIF_MBOX_WIDTH - length);
        }



        if (request & HIF_WRITE) {
            rw = CMD53_WRITE;
            sdrequest->Flags |= SDREQ_FLAGS_DATA_WRITE;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Direction: Write\n"));
        } else if (request & HIF_READ) {
            rw = CMD53_READ;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Direction: Read\n"));
        } else {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Invalid direction: 0x%08x\n", request));
            status = A_EINVAL;
            break;
        }

        if (request & HIF_FIXED_ADDRESS) {
            opcode = CMD53_FIXED_ADDRESS;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Address mode: Fixed\n"));
        } else if (request & HIF_INCREMENTAL_ADDRESS) {
            opcode = CMD53_INCR_ADDRESS;
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Address mode: Incremental\n"));
        } else {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Invalid address mode: 0x%08x\n", request));
            status = A_EINVAL;
            break;
        }

        funcNo = SDDEVICE_GET_SDIO_FUNCNO(device->handle);
        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Function number: %d\n", funcNo));
        SDIO_SET_CMD53_ARG(sdrequest->Argument, rw, funcNo,
                           mode, opcode, address, count);

        /* Send the command out */
        sdiostatus = SDDEVICE_CALL_REQUEST_FUNC(device->handle, sdrequest);

        if (!SDIO_SUCCESS(sdiostatus)) {
            status = A_ERROR;
        }

    } while (FALSE);

    if (A_FAILED(status) || (request & HIF_SYNCHRONOUS)) {
        if (busrequest != NULL) {
            hifFreeBusRequest(busrequest);
        }
    }

    if (A_FAILED(status) && (request & HIF_ASYNCHRONOUS)) {
            /* call back async handler on failure */
        htcCallbacks.rwCompletionHandler(context, status);
    }

    return status;
}

A_STATUS
HIFConfigureDevice(HIF_DEVICE *device, HIF_DEVICE_CONFIG_OPCODE opcode,
                   void *config, A_UINT32 configLen)
{
    A_UINT32 count;

    switch(opcode) {
        case HIF_DEVICE_GET_MBOX_BLOCK_SIZE:
            ((A_UINT32 *)config)[0] = HIF_MBOX0_BLOCK_SIZE;
            ((A_UINT32 *)config)[1] = HIF_MBOX1_BLOCK_SIZE;
            ((A_UINT32 *)config)[2] = HIF_MBOX2_BLOCK_SIZE;
            ((A_UINT32 *)config)[3] = HIF_MBOX3_BLOCK_SIZE;
            break;

        case HIF_DEVICE_GET_MBOX_ADDR:
            for (count = 0; count < 4; count ++) {
                ((A_UINT32 *)config)[count] = HIF_MBOX_START_ADDR(count);
            }
            break;
        case HIF_DEVICE_GET_IRQ_PROC_MODE:
                /* the SDIO stack allows the interrupts to be processed either way, ASYNC or SYNC */
            *((HIF_DEVICE_IRQ_PROCESSING_MODE *)config) = HIF_DEVICE_IRQ_ASYNC_SYNC;
            break;
        default:
            AR_DEBUG_PRINTF(ATH_DEBUG_WARN,
                            ("Unsupported configuration opcode: %d\n", opcode));
            return A_ERROR;
    }

    return A_OK;
}

void
HIFShutDownDevice(HIF_DEVICE *device)
{
    A_UINT8 data;
    A_UINT32 count;
    SDIO_STATUS status;
    SDCONFIG_BUS_MODE_DATA busSettings;
    SDCONFIG_FUNC_ENABLE_DISABLE_DATA fData;

    if (device != NULL) {
        DBG_ASSERT(device->handle != NULL);

        /* Remove the allocated current if any */
        status = SDLIB_IssueConfig(device->handle,
                                   SDCONFIG_FUNC_FREE_SLOT_CURRENT, NULL, 0);
        DBG_ASSERT(SDIO_SUCCESS(status));

        /* Disable the card */
        fData.EnableFlags = SDCONFIG_DISABLE_FUNC;
        fData.TimeOut = 1;
        status = SDLIB_IssueConfig(device->handle, SDCONFIG_FUNC_ENABLE_DISABLE,
                                   &fData, sizeof(fData));
        DBG_ASSERT(SDIO_SUCCESS(status));

        /* Perform a soft I/O reset */
        data = SDIO_IO_RESET;
        status = SDLIB_IssueCMD52(device->handle, 0, SDIO_IO_ABORT_REG,
                                  &data, 1, 1);
        DBG_ASSERT(SDIO_SUCCESS(status));

        /*
         * WAR - Codetelligence driver does not seem to shutdown correctly in 1
         * bit mode. By default it configures the HC in the 4 bit. Its later in
         * our driver that we switch to 1 bit mode. If we try to shutdown, the
         * driver hangs so we revert to 4 bit mode, to be transparent to the
         * underlying bus driver.
         */
        if (onebitmode) {
            ZERO_OBJECT(busSettings);
            busSettings.BusModeFlags = SDDEVICE_GET_BUSMODE_FLAGS(device->handle);
            SDCONFIG_SET_BUS_WIDTH(busSettings.BusModeFlags,
                                   SDCONFIG_BUS_WIDTH_4_BIT);

            /* Issue config request to change the bus width to 4 bit */
            status = SDLIB_IssueConfig(device->handle, SDCONFIG_BUS_MODE_CTRL,
                                       &busSettings,
                                       sizeof(SDCONFIG_BUS_MODE_DATA));
            DBG_ASSERT(SDIO_SUCCESS(status));
        }

        /* Free the bus requests */
        for (count = 0; count < BUS_REQUEST_MAX_NUM; count ++) {
            SDDeviceFreeRequest(device->handle, busRequest[count].request);
        }
        /* Clean up the queue */
        s_busRequestFreeQueue = NULL;
    } else {
            /* since we are unloading the driver anyways, reset all cards in case the SDIO card
             * is externally powered and we are unloading the SDIO stack.  This avoids the problem when
             * the SDIO stack is reloaded and attempts are made to re-enumerate a card that is already
             * enumerated */
        ResetAllCards();
        /* Unregister with bus driver core */
        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                        ("Unregistering with the bus driver\n"));
        status = SDIO_UnregisterFunction(&FunctionContext.function);
        DBG_ASSERT(SDIO_SUCCESS(status));
    }
}

void
hifRWCompletionHandler(SDREQUEST *request)
{
    A_STATUS status;
    void *context;
    BUS_REQUEST *busrequest;

    if (SDIO_SUCCESS(request->Status)) {
        status = A_OK;
    } else {
        status = A_ERROR;
    }

    DBG_ASSERT(status == A_OK);
    busrequest = (BUS_REQUEST *) request->pCompleteContext;
    context = (void *) busrequest->context;
        /* free the request before calling the callback, in case the
         * callback submits another request, this guarantees that
         * there is at least 1 free request available everytime the callback
         * is invoked */
    hifFreeBusRequest(busrequest);
    htcCallbacks.rwCompletionHandler(context, status);
}

void
hifIRQHandler(void *context)
{
    A_STATUS status;
    HIF_DEVICE *device;

    device = (HIF_DEVICE *)context;
    AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Device: %p\n", device));
    status = htcCallbacks.dsrHandler(device->htc_handle);
    DBG_ASSERT(status == A_OK);
}

BOOL
hifDeviceInserted(SDFUNCTION *function, SDDEVICE *handle)
{
    BOOL enabled;
    A_UINT8 data;
    A_UINT32 count;
    HIF_DEVICE *device;
    SDIO_STATUS status;
    A_UINT16 maxBlocks;
    A_UINT16 maxBlockSize;
    SDCONFIG_BUS_MODE_DATA busSettings;
    SDCONFIG_FUNC_ENABLE_DISABLE_DATA fData;
    TARGET_FUNCTION_CONTEXT *functionContext;
    SDCONFIG_FUNC_SLOT_CURRENT_DATA slotCurrent;
    SD_BUSCLOCK_RATE                currentBusClock;

    DBG_ASSERT(function != NULL);
    DBG_ASSERT(handle != NULL);

    device = addHifDevice(handle);
    AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Device: %p\n", device));
    functionContext =  (TARGET_FUNCTION_CONTEXT *)function->pContext;

    /*
     * Issue commands to get the manufacturer ID and stuff and compare it
     * against the rev Id derived from the ID registered during the
     * initialization process. Report the device only in the case there
     * is a match. In the case od SDIO, the bus driver has already queried
     * these details so we just need to use their data structures to get the
     * relevant values. Infact, the driver has already matched it against
     * the Ids that we registered with it so we dont need to the step here.
     */

    /* Configure the SDIO Bus Width */
    if (onebitmode) {
        data = SDIO_BUS_WIDTH_1_BIT;
        status = SDLIB_IssueCMD52(handle, 0, SDIO_BUS_IF_REG, &data, 1, 1);
        if (!SDIO_SUCCESS(status)) {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Unable to set the bus width to 1 bit\n"));
            return FALSE;
        }
    }

    /* Get current bus flags */
    ZERO_OBJECT(busSettings);

    busSettings.BusModeFlags = SDDEVICE_GET_BUSMODE_FLAGS(handle);
    if (onebitmode) {
        SDCONFIG_SET_BUS_WIDTH(busSettings.BusModeFlags,
                               SDCONFIG_BUS_WIDTH_1_BIT);
    }

        /* get the current operating clock, the bus driver sets us up based
         * on what our CIS reports and what the host controller can handle
         * we can use this to determine whether we want to drop our clock rate
         * down */
    currentBusClock = SDDEVICE_GET_OPER_CLOCK(handle);
    busSettings.ClockRate = currentBusClock;

    AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                        ("HIF currently running at: %d \n",currentBusClock));

        /* see if HIF wants to run at a lower clock speed, we may already be
         * at that lower clock speed */
    if (currentBusClock > (SDIO_CLOCK_FREQUENCY_DEFAULT >> busspeedlow)) {
        busSettings.ClockRate = SDIO_CLOCK_FREQUENCY_DEFAULT >> busspeedlow;
        AR_DEBUG_PRINTF(ATH_DEBUG_WARN,
                        ("HIF overriding clock to %d \n",busSettings.ClockRate));
    }

    /* Issue config request to override clock rate */
    status = SDLIB_IssueConfig(handle, SDCONFIG_FUNC_CHANGE_BUS_MODE, &busSettings,
                               sizeof(SDCONFIG_BUS_MODE_DATA));
    if (!SDIO_SUCCESS(status)) {
        AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                        ("Unable to configure the host clock\n"));
        return FALSE;
    } else {
        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                        ("Configured clock: %d, Maximum clock: %d\n",
                        busSettings.ActualClockRate,
                        SDDEVICE_GET_MAX_CLOCK(handle)));
    }

    /*
     * Check if the target supports block mode. This result of this check
     * can be used to implement the HIFReadWrite API.
     */
    if (SDDEVICE_GET_SDIO_FUNC_MAXBLKSIZE(handle)) {
        /* Limit block size to operational block limit or card function
           capability */
        maxBlockSize = min(SDDEVICE_GET_OPER_BLOCK_LEN(handle),
                           SDDEVICE_GET_SDIO_FUNC_MAXBLKSIZE(handle));

        /* check if the card support multi-block transfers */
        if (!(SDDEVICE_GET_SDIOCARD_CAPS(handle) & SDIO_CAPS_MULTI_BLOCK)) {
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Byte basis only\n"));

            /* Limit block size to max byte basis */
            maxBlockSize =  min(maxBlockSize,
                                (A_UINT16)SDIO_MAX_LENGTH_BYTE_BASIS);
            maxBlocks = 1;
        } else {
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Multi-block capable\n"));
            maxBlocks = SDDEVICE_GET_OPER_BLOCKS(handle);
            status = SDLIB_SetFunctionBlockSize(handle, HIF_MBOX_BLOCK_SIZE);
            if (!SDIO_SUCCESS(status)) {
                AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                                ("Failed to set block size. Err:%d\n", status));
                return FALSE;
            }
        }

        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                        ("Bytes Per Block: %d bytes, Block Count:%d \n",
                        maxBlockSize, maxBlocks));
    } else {
        AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                        ("Function does not support Block Mode!\n"));
        return FALSE;
    }

    /* Allocate the slot current */
    status = SDLIB_GetDefaultOpCurrent(handle, &slotCurrent.SlotCurrent);
    if (SDIO_SUCCESS(status)) {
        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Allocating Slot current: %d mA\n",
                                slotCurrent.SlotCurrent));
        status = SDLIB_IssueConfig(handle, SDCONFIG_FUNC_ALLOC_SLOT_CURRENT,
                                   &slotCurrent, sizeof(slotCurrent));
        if (!SDIO_SUCCESS(status)) {
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                            ("Failed to allocate slot current %d\n", status));
            return FALSE;
        }
    }

    /* Enable the dragon function */
    count = 0;
    enabled = FALSE;
    fData.TimeOut = 1;
    fData.EnableFlags = SDCONFIG_ENABLE_FUNC;
    while ((count++ < SDWLAN_ENABLE_DISABLE_TIMEOUT) && !enabled)
    {
        /* Enable dragon */
        status = SDLIB_IssueConfig(handle, SDCONFIG_FUNC_ENABLE_DISABLE,
                                   &fData, sizeof(fData));
        if (!SDIO_SUCCESS(status)) {
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                            ("Attempting to enable the card again\n"));
            continue;
        }

        /* Mark the status as enabled */
        enabled = TRUE;
    }

    /* Check if we were succesful in enabling the target */
    if (!enabled) {
        AR_DEBUG_PRINTF(ATH_DEBUG_ERROR,
                        ("Failed to communicate with the target\n"));
        return FALSE;
    }

    /* Allocate the bus requests to be used later */
    A_MEMZERO(busRequest, sizeof(busRequest));
    for (count = 0; count < BUS_REQUEST_MAX_NUM; count ++) {
        if ((busRequest[count].request = SDDeviceAllocRequest(handle)) == NULL){
            AR_DEBUG_PRINTF(ATH_DEBUG_ERROR, ("Unable to allocate memory\n"));
            /* TODO: Free the memory that has already been allocated */
            return FALSE;
        }
        hifFreeBusRequest(&busRequest[count]);

        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                ("0x%08x = busRequest[%d].request = 0x%08x\n",
				(unsigned int) &busRequest[count], count,
				(unsigned int) busRequest[count].request));
    }

        /* Schedule a worker to handle device inserted, this is a temporary workaround
         * to fix a deadlock if the device fails to intialize in the insertion handler
         * The failure causes the instance to shutdown the HIF layer and unregister the
         * function driver within the busdriver probe context which can deadlock
         *
         * NOTE: we cannot use the default work queue because that would block
         * SD bus request processing for all synchronous I/O. We must use a kernel
         * thread that is creating using the helper library.
         * */

    if (SDIO_SUCCESS(SDLIB_OSCreateHelper(&device->insert_helper,
                         insert_helper_func,
                         device))) {
        device->helper_started = TRUE;
    }

    return TRUE;
}

static THREAD_RETURN insert_helper_func(POSKERNEL_HELPER pHelper)
{

    /*
     * Adding a wait of around a second before we issue the very first
     * command to dragon. During the process of loading/unloading the
     * driver repeatedly it was observed that we get a data timeout
     * while accessing function 1 registers in the chip. The theory at
     * this point is that some initialization delay in dragon is
     * causing the SDIO state in dragon core to be not ready even after
     * the ready bit indicates that function 1 is ready. Accomodating
     * for this behavior by adding some delay in the driver before it
     * issues the first command after switching on dragon. Need to
     * investigate this a bit more - TODO
     */

    A_MDELAY(1000);
        /* Inform HTC */
    if ((htcCallbacks.deviceInsertedHandler(SD_GET_OS_HELPER_CONTEXT(pHelper))) != A_OK) {
        AR_DEBUG_PRINTF(ATH_DEBUG_TRACE, ("Device rejected\n"));
    }

    return 0;
}

void
HIFAckInterrupt(HIF_DEVICE *device)
{
    SDIO_STATUS status;
    DBG_ASSERT(device != NULL);
    DBG_ASSERT(device->handle != NULL);

    /* Acknowledge our function IRQ */
    status = SDLIB_IssueConfig(device->handle, SDCONFIG_FUNC_ACK_IRQ,
                               NULL, 0);
    DBG_ASSERT(SDIO_SUCCESS(status));
}

void
HIFUnMaskInterrupt(HIF_DEVICE *device)
{
    SDIO_STATUS status;

    DBG_ASSERT(device != NULL);
    DBG_ASSERT(device->handle != NULL);

    /* Register the IRQ Handler */
    SDDEVICE_SET_IRQ_HANDLER(device->handle, hifIRQHandler, device);

    /* Unmask our function IRQ */
    status = SDLIB_IssueConfig(device->handle, SDCONFIG_FUNC_UNMASK_IRQ,
                               NULL, 0);
    DBG_ASSERT(SDIO_SUCCESS(status));
}

void HIFMaskInterrupt(HIF_DEVICE *device)
{
    SDIO_STATUS status;
    DBG_ASSERT(device != NULL);
    DBG_ASSERT(device->handle != NULL);

    /* Mask our function IRQ */
    status = SDLIB_IssueConfig(device->handle, SDCONFIG_FUNC_MASK_IRQ,
                               NULL, 0);
    DBG_ASSERT(SDIO_SUCCESS(status));

    /* Unregister the IRQ Handler */
    SDDEVICE_SET_IRQ_HANDLER(device->handle, NULL, NULL);
}

static BUS_REQUEST *hifAllocateBusRequest(void)
{
    BUS_REQUEST *busrequest;

    /* Acquire lock */
    CriticalSectionAcquire(&lock);

    /* Remove first in list */
    if((busrequest = s_busRequestFreeQueue) != NULL)
    {
        s_busRequestFreeQueue = busrequest->next;
    }

    /* Release lock */
    CriticalSectionRelease(&lock);

    return busrequest;
}

static void
hifFreeBusRequest(BUS_REQUEST *busrequest)
{
    DBG_ASSERT(busrequest != NULL);

    /* Acquire lock */
    CriticalSectionAcquire(&lock);

    /* Insert first in list */
    busrequest->next = s_busRequestFreeQueue;
    s_busRequestFreeQueue = busrequest;

    /* Release lock */
    CriticalSectionRelease(&lock);
}

void
hifDeviceRemoved(SDFUNCTION *function, SDDEVICE *handle)
{
    A_STATUS status;
    HIF_DEVICE *device;
    DBG_ASSERT(function != NULL);
    DBG_ASSERT(handle != NULL);

    device = getHifDevice(handle);
    status = htcCallbacks.deviceRemovedHandler(device->htc_handle, A_OK);

        /* cleanup the helper thread */
    if (device->helper_started) {
        SDLIB_OSDeleteHelper(&device->insert_helper);
        device->helper_started = FALSE;
    }

    delHifDevice(handle);
    DBG_ASSERT(status == A_OK);
}

HIF_DEVICE *
addHifDevice(SDDEVICE *handle)
{
    DBG_ASSERT(handle != NULL);
    hifDevice[0].handle = handle;
    return &hifDevice[0];
}

HIF_DEVICE *
getHifDevice(SDDEVICE *handle)
{
    DBG_ASSERT(handle != NULL);
    return &hifDevice[0];
}

void
delHifDevice(SDDEVICE *handle)
{
    DBG_ASSERT(handle != NULL);
    hifDevice[0].handle = NULL;
}

struct device*
HIFGetOSDevice(HIF_DEVICE *device)
{
    return &device->handle->Device->dev;
}

static void ResetAllCards(void)
{
    UINT8       data;
    SDIO_STATUS status;
    int         i;

    data = SDIO_IO_RESET;

    /* set the I/O CARD reset bit:
     * NOTE: we are exploiting a "feature" of the SDIO core that resets the core when you
     * set the RES bit in the SDIO_IO_ABORT register.  This bit however "normally" resets the
     * I/O functions leaving the SDIO core in the same state (as per SDIO spec).
     * In this design, this reset can be used to reset the SDIO core itself */
    for (i = 0; i < HIF_MAX_DEVICES; i++) {
        if (hifDevice[i].handle != NULL) {
            AR_DEBUG_PRINTF(ATH_DEBUG_TRACE,
                        ("Issuing I/O Card reset for instance: %d \n",i));
                /* set the I/O Card reset bit */
            status = SDLIB_IssueCMD52(hifDevice[i].handle,
                                      0,                    /* function 0 space */
                                      SDIO_IO_ABORT_REG,
                                      &data,
                                      1,                    /* 1 byte */
                                      TRUE);                /* write */
        }
    }

}

void HIFSetHandle(void *hif_handle, void *handle)
{
    HIF_DEVICE *device = (HIF_DEVICE *) hif_handle;

    device->htc_handle = handle;

    return;
}