Fix common misspellings

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / staging / westbridge / astoria / api / src / cyasdma.c

/* Cypress West Bridge API source file (cyasdma.c)
## ===========================
## Copyright (C) 2010  Cypress Semiconductor
##
## This program is free software; you can redistribute it and/or
## modify it under the terms of the GNU General Public License
## as published by the Free Software Foundation; either version 2
## of the License, or (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 51 Franklin Street, Fifth Floor
## Boston, MA  02110-1301, USA.
## ===========================
*/

#include "../../include/linux/westbridge/cyashal.h"
#include "../../include/linux/westbridge/cyasdma.h"
#include "../../include/linux/westbridge/cyaslowlevel.h"
#include "../../include/linux/westbridge/cyaserr.h"
#include "../../include/linux/westbridge/cyasregs.h"

/*
 * Add the DMA queue entry to the free list to be re-used later
 */
static void
cy_as_dma_add_request_to_free_queue(cy_as_device *dev_p,
        cy_as_dma_queue_entry *req_p)
{
        uint32_t imask;
        imask = cy_as_hal_disable_interrupts();

        req_p->next_p = dev_p->dma_freelist_p;
        dev_p->dma_freelist_p = req_p;

        cy_as_hal_enable_interrupts(imask);
}

/*
 * Get a DMA queue entry from the free list.
 */
static cy_as_dma_queue_entry *
cy_as_dma_get_dma_queue_entry(cy_as_device *dev_p)
{
        cy_as_dma_queue_entry *req_p;
        uint32_t imask;

        cy_as_hal_assert(dev_p->dma_freelist_p != 0);

        imask = cy_as_hal_disable_interrupts();
        req_p = dev_p->dma_freelist_p;
        dev_p->dma_freelist_p = req_p->next_p;
        cy_as_hal_enable_interrupts(imask);

        return req_p;
}

/*
 * Set the maximum size that the West Bridge hardware
 * can handle in a single DMA operation.  This size
 * may change for the P <-> U endpoints as a function
 * of the endpoint type and whether we are running
 * at full speed or high speed.
 */
cy_as_return_status_t
cy_as_dma_set_max_dma_size(cy_as_device *dev_p,
                cy_as_end_point_number_t ep, uint32_t size)
{
        /* In MTP mode, EP2 is allowed to have all max sizes. */
        if ((!dev_p->is_mtp_firmware) || (ep != 0x02)) {
                if (size < 64 || size > 1024)
                        return CY_AS_ERROR_INVALID_SIZE;
        }

        CY_AS_NUM_EP(dev_p, ep)->maxhwdata = (uint16_t)size;
        return CY_AS_ERROR_SUCCESS;
}

/*
 * The callback for requests sent to West Bridge
 * to relay endpoint data.  Endpoint data for EP0
 * and EP1 are sent using mailbox requests.  This
 * is the callback that is called when a response
 * to a mailbox request to send data is received.
 */
static void
cy_as_dma_request_callback(
        cy_as_device *dev_p,
        uint8_t context,
        cy_as_ll_request_response *req_p,
        cy_as_ll_request_response *resp_p,
        cy_as_return_status_t ret)
{
        uint16_t v;
        uint16_t datacnt;
        cy_as_end_point_number_t ep;

        (void)context;

        cy_as_log_debug_message(5, "cy_as_dma_request_callback called");

        /*
         * extract the return code from the firmware
         */
        if (ret == CY_AS_ERROR_SUCCESS) {
                if (cy_as_ll_request_response__get_code(resp_p) !=
                CY_RESP_SUCCESS_FAILURE)
                        ret = CY_AS_ERROR_INVALID_RESPONSE;
                else
                        ret = cy_as_ll_request_response__get_word(resp_p, 0);
        }

        /*
         * extract the endpoint number and the transferred byte count
         * from the request.
         */
        v = cy_as_ll_request_response__get_word(req_p, 0);
        ep = (cy_as_end_point_number_t)((v >> 13) & 0x01);

        if (ret == CY_AS_ERROR_SUCCESS) {
                /*
                 * if the firmware returns success,
                 * all of the data requested was
                 * transferred.  there are no partial
                 * transfers.
                 */
                datacnt = v & 0x3FF;
        } else {
                /*
                 * if the firmware returned an error, no data was transferred.
                 */
                datacnt = 0;
        }

        /*
         * queue the request and response data structures for use with the
         * next EP0 or EP1 request.
         */
        if (ep == 0) {
                dev_p->usb_ep0_dma_req = req_p;
                dev_p->usb_ep0_dma_resp = resp_p;
        } else {
                dev_p->usb_ep1_dma_req = req_p;
                dev_p->usb_ep1_dma_resp = resp_p;
        }

        /*
         * call the DMA complete function so we can
         * signal that this portion of the transfer
         * has completed.  if the low level request
         * was canceled, we do not need to signal
         * the completed function as the only way a
         * cancel can happen is via the DMA cancel
         * function.
         */
        if (ret != CY_AS_ERROR_CANCELED)
                cy_as_dma_completed_callback(dev_p->tag, ep, datacnt, ret);
}

/*
 * Set the DRQ mask register for the given endpoint number.  If state is
 * CyTrue, the DRQ interrupt for the given endpoint is enabled, otherwise
 * it is disabled.
 */
static void
cy_as_dma_set_drq(cy_as_device *dev_p,
                cy_as_end_point_number_t ep, cy_bool state)
{
        uint16_t mask;
        uint16_t v;
        uint32_t intval;

        /*
         * there are not DRQ register bits for EP0 and EP1
         */
        if (ep == 0 || ep == 1)
                return;

        /*
         * disable interrupts while we do this to be sure the state of the
         * DRQ mask register is always well defined.
         */
        intval = cy_as_hal_disable_interrupts();

        /*
         * set the DRQ bit to the given state for the ep given
         */
        mask = (1 << ep);
        v = cy_as_hal_read_register(dev_p->tag, CY_AS_MEM_P0_DRQ_MASK);

        if (state)
                v |= mask;
        else
                v &= ~mask;

        cy_as_hal_write_register(dev_p->tag, CY_AS_MEM_P0_DRQ_MASK, v);
        cy_as_hal_enable_interrupts(intval);
}

/*
* Send the next DMA request for the endpoint given
*/
static void
cy_as_dma_send_next_dma_request(cy_as_device *dev_p, cy_as_dma_end_point *ep_p)
{
        uint32_t datacnt;
        void *buf_p;
        cy_as_dma_queue_entry *dma_p;

        cy_as_log_debug_message(6, "cy_as_dma_send_next_dma_request called");

        /* If the queue is empty, nothing to do */
        dma_p = ep_p->queue_p;
        if (dma_p == 0) {
                /*
                 * there are no pending DMA requests
                 * for this endpoint.  disable the DRQ
                 * mask bits to insure no interrupts
                 * will be triggered by this endpoint
                 * until someone is interested in the data.
                 */
                cy_as_dma_set_drq(dev_p, ep_p->ep, cy_false);
                return;
        }

        cy_as_dma_end_point_set_running(ep_p);

        /*
         * get the number of words that still
         * need to be xferred in this request.
         */
        datacnt = dma_p->size - dma_p->offset;
        cy_as_hal_assert(datacnt >= 0);

        /*
         * the HAL layer should never limit the size
         * of the transfer to something less than the
         * maxhwdata otherwise, the data will be sent
         * in packets that are not correct in size.
         */
        cy_as_hal_assert(ep_p->maxhaldata == CY_AS_DMA_MAX_SIZE_HW_SIZE
                        || ep_p->maxhaldata >= ep_p->maxhwdata);

        /*
         * update the number of words that need to be xferred yet
         * based on the limits of the HAL layer.
         */
        if (ep_p->maxhaldata == CY_AS_DMA_MAX_SIZE_HW_SIZE) {
                if (datacnt > ep_p->maxhwdata)
                        datacnt = ep_p->maxhwdata;
        } else {
                if (datacnt > ep_p->maxhaldata)
                        datacnt = ep_p->maxhaldata;
        }

        /*
         * find a pointer to the data that needs to be transferred
         */
        buf_p = (((char *)dma_p->buf_p) + dma_p->offset);

        /*
         * mark a request in transit
         */
        cy_as_dma_end_point_set_in_transit(ep_p);

        if (ep_p->ep == 0 || ep_p->ep == 1) {
                /*
                 * if this is a WRITE request on EP0 and EP1
                 * we write the data via an EP_DATA request
                 * to west bridge via the mailbox registers.
                 * if this is a READ request, we do nothing
                 * and the data will arrive via an EP_DATA
                 * request from west bridge.  in the request
                 * handler for the USB context we will pass
                 * the data back into the DMA module.
                 */
                if (dma_p->readreq == cy_false) {
                        uint16_t v;
                        uint16_t len;
                        cy_as_ll_request_response *resp_p;
                        cy_as_ll_request_response *req_p;
                        cy_as_return_status_t ret;

                        len = (uint16_t)(datacnt / 2);
                        if (datacnt % 2)
                                len++;

                        len++;

                        if (ep_p->ep == 0) {
                                req_p = dev_p->usb_ep0_dma_req;
                                resp_p = dev_p->usb_ep0_dma_resp;
                                dev_p->usb_ep0_dma_req = 0;
                                dev_p->usb_ep0_dma_resp = 0;
                        } else {
                                req_p = dev_p->usb_ep1_dma_req;
                                resp_p = dev_p->usb_ep1_dma_resp;
                                dev_p->usb_ep1_dma_req = 0;
                                dev_p->usb_ep1_dma_resp = 0;
                        }

                        cy_as_hal_assert(req_p != 0);
                        cy_as_hal_assert(resp_p != 0);
                        cy_as_hal_assert(len <= 64);

                        cy_as_ll_init_request(req_p, CY_RQT_USB_EP_DATA,
                                CY_RQT_USB_RQT_CONTEXT, len);

                        v = (uint16_t)(datacnt | (ep_p->ep << 13) | (1 << 14));
                        if (dma_p->offset == 0)
                                v |= (1 << 12);/* Set the first packet bit */
                        if (dma_p->offset + datacnt == dma_p->size)
                                v |= (1 << 11);/* Set the last packet bit */

                        cy_as_ll_request_response__set_word(req_p, 0, v);
                        cy_as_ll_request_response__pack(req_p,
                                        1, datacnt, buf_p);

                        cy_as_ll_init_response(resp_p, 1);

                        ret = cy_as_ll_send_request(dev_p, req_p, resp_p,
                                cy_false, cy_as_dma_request_callback);
                        if (ret == CY_AS_ERROR_SUCCESS)
                                cy_as_log_debug_message(5,
                                "+++ send EP 0/1 data via mailbox registers");
                        else
                                cy_as_log_debug_message(5,
                                "+++ error sending EP 0/1 data via mailbox "
                                "registers - CY_AS_ERROR_TIMEOUT");

                        if (ret != CY_AS_ERROR_SUCCESS)
                                cy_as_dma_completed_callback(dev_p->tag,
                                        ep_p->ep, 0, ret);
                }
        } else {
                /*
                 * this is a DMA request on an endpoint that is accessible
                 * via the P port.  ask the HAL DMA capabilities to
                 * perform this.  the amount of data sent is limited by the
                 * HAL max size as well as what we need to send.  if the
                 * ep_p->maxhaldata is set to a value larger than the
                 * endpoint buffer size, then we will pass more than a
                 * single buffer worth of data to the HAL layer and expect
                 * the HAL layer to divide the data into packets.  the last
                 * parameter here (ep_p->maxhwdata) gives the packet size for
                 * the data so the HAL layer knows what the packet size should
                 * be.
                 */
                if (cy_as_dma_end_point_is_direction_in(ep_p))
                        cy_as_hal_dma_setup_write(dev_p->tag,
                                ep_p->ep, buf_p, datacnt, ep_p->maxhwdata);
                else
                        cy_as_hal_dma_setup_read(dev_p->tag,
                                ep_p->ep, buf_p, datacnt, ep_p->maxhwdata);

                /*
                 * the DRQ interrupt for this endpoint should be enabled
                 * so that the data transfer progresses at interrupt time.
                 */
                cy_as_dma_set_drq(dev_p, ep_p->ep, cy_true);
        }
}

/*
 * This function is called when the HAL layer has
 * completed the last requested DMA operation.
 * This function sends/receives the next batch of
 * data associated with the current DMA request,
 * or it is is complete, moves to the next DMA request.
 */
void
cy_as_dma_completed_callback(cy_as_hal_device_tag tag,
        cy_as_end_point_number_t ep, uint32_t cnt, cy_as_return_status_t status)
{
        uint32_t mask;
        cy_as_dma_queue_entry *req_p;
        cy_as_dma_end_point *ep_p;
        cy_as_device *dev_p = cy_as_device_find_from_tag(tag);

        /* Make sure the HAL layer gave us good parameters */
        cy_as_hal_assert(dev_p != 0);
        cy_as_hal_assert(dev_p->sig == CY_AS_DEVICE_HANDLE_SIGNATURE);
        cy_as_hal_assert(ep < 16);


        /* Get the endpoint ptr */
        ep_p = CY_AS_NUM_EP(dev_p, ep);
        cy_as_hal_assert(ep_p->queue_p != 0);

        /* Get a pointer to the current entry in the queue */
        mask = cy_as_hal_disable_interrupts();
        req_p = ep_p->queue_p;

        /* Update the offset to reflect the data actually received or sent */
        req_p->offset += cnt;

        /*
         * if we are still sending/receiving the current packet,
         * send/receive the next chunk basically we keep going
         * if we have not sent/received enough data, and we are
         * not doing a packet operation, and the last packet
         * sent or received was a full sized packet.  in other
         * words, when we are NOT doing a packet operation, a
         * less than full size packet (a short packet) will
         * terminate the operation.
         *
         * note: if this is EP1 request and the request has
         * timed out, it means the buffer is not free.
         * we have to resend the data.
         *
         * note: for the MTP data transfers, the DMA transfer
         * for the next packet can only be started asynchronously,
         * after a firmware event notifies that the device is ready.
         */
        if (((req_p->offset != req_p->size) && (req_p->packet == cy_false) &&
                ((cnt == ep_p->maxhaldata) || ((cnt == ep_p->maxhwdata) &&
                ((ep != CY_AS_MTP_READ_ENDPOINT) ||
                (cnt == dev_p->usb_max_tx_size)))))
                        || ((ep == 1) && (status == CY_AS_ERROR_TIMEOUT))) {
                cy_as_hal_enable_interrupts(mask);

                /*
                 * and send the request again to send the next block of
                 * data. special handling for MTP transfers on E_ps 2
                 * and 6. the send_next_request will be processed based
                 * on the event sent by the firmware.
                 */
                if ((ep == CY_AS_MTP_WRITE_ENDPOINT) || (
                                (ep == CY_AS_MTP_READ_ENDPOINT) &&
                                (!cy_as_dma_end_point_is_direction_in(ep_p))))
                        cy_as_dma_end_point_set_stopped(ep_p);
                else
                        cy_as_dma_send_next_dma_request(dev_p, ep_p);
        } else {
                /*
                 * we get here if ...
                 *      we have sent or received all of the data
                 *               or
                 *      we are doing a packet operation
                 *               or
                 *      we receive a short packet
                 */

                /*
                 * remove this entry from the DMA queue for this endpoint.
                 */
                cy_as_dma_end_point_clear_in_transit(ep_p);
                ep_p->queue_p = req_p->next_p;
                if (ep_p->last_p == req_p) {
                        /*
                         * we have removed the last packet from the DMA queue,
                         * disable the interrupt associated with this interrupt.
                         */
                        ep_p->last_p = 0;
                        cy_as_hal_enable_interrupts(mask);
                        cy_as_dma_set_drq(dev_p, ep, cy_false);
                } else
                        cy_as_hal_enable_interrupts(mask);

                if (req_p->cb) {
                        /*
                         * if the request has a callback associated with it,
                         * call the callback to tell the interested party that
                         * this DMA request has completed.
                         *
                         * note, we set the in_callback bit to insure that we
                         * cannot recursively call an API function that is
                         * synchronous only from a callback.
                         */
                        cy_as_device_set_in_callback(dev_p);
                        (*req_p->cb)(dev_p, ep, req_p->buf_p,
                                req_p->offset, status);
                        cy_as_device_clear_in_callback(dev_p);
                }

                /*
                 * we are done with this request, put it on the freelist to be
                 * reused at a later time.
                 */
                cy_as_dma_add_request_to_free_queue(dev_p, req_p);

                if (ep_p->queue_p == 0) {
                        /*
                         * if the endpoint is out of DMA entries, set the
                         * endpoint as stopped.
                         */
                        cy_as_dma_end_point_set_stopped(ep_p);

                        /*
                         * the DMA queue is empty, wake any task waiting on
                         * the QUEUE to drain.
                         */
                        if (cy_as_dma_end_point_is_sleeping(ep_p)) {
                                cy_as_dma_end_point_set_wake_state(ep_p);
                                cy_as_hal_wake(&ep_p->channel);
                        }
                } else {
                        /*
                         * if the queued operation is a MTP transfer,
                         * wait until firmware event before sending
                         * down the next DMA request.
                         */
                        if ((ep == CY_AS_MTP_WRITE_ENDPOINT) ||
                                ((ep == CY_AS_MTP_READ_ENDPOINT) &&
                                (!cy_as_dma_end_point_is_direction_in(ep_p))) ||
                                ((ep == dev_p->storage_read_endpoint) &&
                                (!cy_as_device_is_p2s_dma_start_recvd(dev_p)))
                                || ((ep == dev_p->storage_write_endpoint) &&
                                (!cy_as_device_is_p2s_dma_start_recvd(dev_p))))
                                cy_as_dma_end_point_set_stopped(ep_p);
                        else
                                cy_as_dma_send_next_dma_request(dev_p, ep_p);
                }
        }
}

/*
* This function is used to kick start DMA on a given
* channel.  If DMA is already running on the given
* endpoint, nothing happens.  If DMA is not running,
* the first entry is pulled from the DMA queue and
* sent/recevied to/from the West Bridge device.
*/
cy_as_return_status_t
cy_as_dma_kick_start(cy_as_device *dev_p, cy_as_end_point_number_t ep)
{
        cy_as_dma_end_point *ep_p;
        cy_as_hal_assert(dev_p->sig == CY_AS_DEVICE_HANDLE_SIGNATURE);

        ep_p = CY_AS_NUM_EP(dev_p, ep);

        /* We are already running */
        if (cy_as_dma_end_point_is_running(ep_p))
                return CY_AS_ERROR_SUCCESS;

        cy_as_dma_send_next_dma_request(dev_p, ep_p);
        return CY_AS_ERROR_SUCCESS;
}

/*
 * This function stops the given endpoint.  Stopping and endpoint cancels
 * any pending DMA operations and frees all resources associated with the
 * given endpoint.
 */
static cy_as_return_status_t
cy_as_dma_stop_end_point(cy_as_device *dev_p, cy_as_end_point_number_t ep)
{
        cy_as_return_status_t ret;
        cy_as_dma_end_point *ep_p = CY_AS_NUM_EP(dev_p, ep);

        /*
         * cancel any pending DMA requests associated with this endpoint. this
         * cancels any DMA requests at the HAL layer as well as dequeues any
         * request that is currently pending.
         */
        ret = cy_as_dma_cancel(dev_p, ep, CY_AS_ERROR_CANCELED);
        if (ret != CY_AS_ERROR_SUCCESS)
                return ret;

        /*
         * destroy the sleep channel
         */
        if (!cy_as_hal_destroy_sleep_channel(&ep_p->channel)
                && ret == CY_AS_ERROR_SUCCESS)
                ret = CY_AS_ERROR_DESTROY_SLEEP_CHANNEL_FAILED;

        /*
         * free the memory associated with this endpoint
         */
        cy_as_hal_free(ep_p);

        /*
         * set the data structure ptr to something sane since the
         * previous pointer is now free.
         */
        dev_p->endp[ep] = 0;

        return ret;
}

/*
 * This method stops the USB stack.  This is an internal function that does
 * all of the work of destroying the USB stack without the protections that
 * we provide to the API (i.e. stopping at stack that is not running).
 */
static cy_as_return_status_t
cy_as_dma_stop_internal(cy_as_device *dev_p)
{
        cy_as_return_status_t ret = CY_AS_ERROR_SUCCESS;
        cy_as_return_status_t lret;
        cy_as_end_point_number_t i;

        /*
         * stop all of the endpoints.  this cancels all DMA requests, and
         * frees all resources associated with each endpoint.
         */
        for (i = 0; i < sizeof(dev_p->endp)/(sizeof(dev_p->endp[0])); i++) {
                lret = cy_as_dma_stop_end_point(dev_p, i);
                if (lret != CY_AS_ERROR_SUCCESS && ret == CY_AS_ERROR_SUCCESS)
                        ret = lret;
        }

        /*
         * now, free the list of DMA requests structures that we use to manage
         * DMA requests.
         */
        while (dev_p->dma_freelist_p) {
                cy_as_dma_queue_entry *req_p;
                uint32_t imask = cy_as_hal_disable_interrupts();

                req_p = dev_p->dma_freelist_p;
                dev_p->dma_freelist_p = req_p->next_p;

                cy_as_hal_enable_interrupts(imask);

                cy_as_hal_free(req_p);
        }

        cy_as_ll_destroy_request(dev_p, dev_p->usb_ep0_dma_req);
        cy_as_ll_destroy_request(dev_p, dev_p->usb_ep1_dma_req);
        cy_as_ll_destroy_response(dev_p, dev_p->usb_ep0_dma_resp);
        cy_as_ll_destroy_response(dev_p, dev_p->usb_ep1_dma_resp);

        return ret;
}


/*
 * CyAsDmaStop()
 *
 * This function shuts down the DMA module.  All resources
 * associated with the DMA module will be freed.  This
 * routine is the API stop function.  It insures that we
 * are stopping a stack that is actually running and then
 * calls the internal function to do the work.
 */
cy_as_return_status_t
cy_as_dma_stop(cy_as_device *dev_p)
{
        cy_as_return_status_t ret;

        ret = cy_as_dma_stop_internal(dev_p);
        cy_as_device_set_dma_stopped(dev_p);

        return ret;
}

/*
 * CyAsDmaStart()
 *
 * This function initializes the DMA module to insure it is up and running.
 */
cy_as_return_status_t
cy_as_dma_start(cy_as_device *dev_p)
{
        cy_as_end_point_number_t i;
        uint16_t cnt;

        if (cy_as_device_is_dma_running(dev_p))
                return CY_AS_ERROR_ALREADY_RUNNING;

        /*
         * pre-allocate DMA queue structures to be used in the interrupt context
         */
        for (cnt = 0; cnt < 32; cnt++) {
                cy_as_dma_queue_entry *entry_p = (cy_as_dma_queue_entry *)
                        cy_as_hal_alloc(sizeof(cy_as_dma_queue_entry));
                if (entry_p == 0) {
                        cy_as_dma_stop_internal(dev_p);
                        return CY_AS_ERROR_OUT_OF_MEMORY;
                }
                cy_as_dma_add_request_to_free_queue(dev_p, entry_p);
        }

        /*
         * pre-allocate the DMA requests for sending EP0
         * and EP1 data to west bridge
         */
        dev_p->usb_ep0_dma_req = cy_as_ll_create_request(dev_p,
                CY_RQT_USB_EP_DATA, CY_RQT_USB_RQT_CONTEXT, 64);
        dev_p->usb_ep1_dma_req = cy_as_ll_create_request(dev_p,
                CY_RQT_USB_EP_DATA, CY_RQT_USB_RQT_CONTEXT, 64);

        if (dev_p->usb_ep0_dma_req == 0 || dev_p->usb_ep1_dma_req == 0) {
                cy_as_dma_stop_internal(dev_p);
                return CY_AS_ERROR_OUT_OF_MEMORY;
        }
        dev_p->usb_ep0_dma_req_save = dev_p->usb_ep0_dma_req;

        dev_p->usb_ep0_dma_resp = cy_as_ll_create_response(dev_p, 1);
        dev_p->usb_ep1_dma_resp = cy_as_ll_create_response(dev_p, 1);
        if (dev_p->usb_ep0_dma_resp == 0 || dev_p->usb_ep1_dma_resp == 0) {
                cy_as_dma_stop_internal(dev_p);
                return CY_AS_ERROR_OUT_OF_MEMORY;
        }
        dev_p->usb_ep0_dma_resp_save = dev_p->usb_ep0_dma_resp;

        /*
         * set the dev_p->endp to all zeros to insure cleanup is possible if
         * an error occurs during initialization.
         */
        cy_as_hal_mem_set(dev_p->endp, 0, sizeof(dev_p->endp));

        /*
         * now, iterate through each of the endpoints and initialize each
         * one.
         */
        for (i = 0; i < sizeof(dev_p->endp)/sizeof(dev_p->endp[0]); i++) {
                dev_p->endp[i] = (cy_as_dma_end_point *)
                        cy_as_hal_alloc(sizeof(cy_as_dma_end_point));
                if (dev_p->endp[i] == 0) {
                        cy_as_dma_stop_internal(dev_p);
                        return CY_AS_ERROR_OUT_OF_MEMORY;
                }
                cy_as_hal_mem_set(dev_p->endp[i], 0,
                        sizeof(cy_as_dma_end_point));

                dev_p->endp[i]->ep = i;
                dev_p->endp[i]->queue_p = 0;
                dev_p->endp[i]->last_p = 0;

                cy_as_dma_set_drq(dev_p, i, cy_false);

                if (!cy_as_hal_create_sleep_channel(&dev_p->endp[i]->channel))
                        return CY_AS_ERROR_CREATE_SLEEP_CHANNEL_FAILED;
        }

        /*
         * tell the HAL layer who to call when the
         * HAL layer completes a DMA request
         */
        cy_as_hal_dma_register_callback(dev_p->tag,
                cy_as_dma_completed_callback);

        /*
         * mark DMA as up and running on this device
         */
        cy_as_device_set_dma_running(dev_p);

        return CY_AS_ERROR_SUCCESS;
}

/*
* Wait for all entries in the DMA queue associated
* the given endpoint to be drained.  This function
* will not return until all the DMA data has been
* transferred.
*/
cy_as_return_status_t
cy_as_dma_drain_queue(cy_as_device *dev_p,
        cy_as_end_point_number_t ep, cy_bool kickstart)
{
        cy_as_dma_end_point *ep_p;
        int loopcount = 1000;
        uint32_t mask;

        /*
        * make sure the endpoint is valid
        */
        if (ep >= sizeof(dev_p->endp)/sizeof(dev_p->endp[0]))
                return CY_AS_ERROR_INVALID_ENDPOINT;

        /* Get the endpoint pointer based on the endpoint number */
        ep_p = CY_AS_NUM_EP(dev_p, ep);

        /*
        * if the endpoint is empty of traffic, we return
        * with success immediately
        */
        mask = cy_as_hal_disable_interrupts();
        if (ep_p->queue_p == 0) {
                cy_as_hal_enable_interrupts(mask);
                return CY_AS_ERROR_SUCCESS;
        } else {
                /*
                 * add 10 seconds to the time out value for each 64 KB segment
                 * of data to be transferred.
                 */
                if (ep_p->queue_p->size > 0x10000)
                        loopcount += ((ep_p->queue_p->size / 0x10000) * 1000);
        }
        cy_as_hal_enable_interrupts(mask);

        /* If we are already sleeping on this endpoint, it is an error */
        if (cy_as_dma_end_point_is_sleeping(ep_p))
                return CY_AS_ERROR_NESTED_SLEEP;

        /*
        * we disable the endpoint while the queue drains to
        * prevent any additional requests from being queued while we are waiting
        */
        cy_as_dma_enable_end_point(dev_p, ep,
                cy_false, cy_as_direction_dont_change);

        if (kickstart) {
                /*
                * now, kick start the DMA if necessary
                */
                cy_as_dma_kick_start(dev_p, ep);
        }

        /*
        * check one last time before we begin sleeping to see if the
        * queue is drained.
        */
        if (ep_p->queue_p == 0) {
                cy_as_dma_enable_end_point(dev_p, ep, cy_true,
                        cy_as_direction_dont_change);
                return CY_AS_ERROR_SUCCESS;
        }

        while (loopcount-- > 0) {
                /*
                 * sleep for 10 ms maximum (per loop) while
                 * waiting for the transfer to complete.
                 */
                cy_as_dma_end_point_set_sleep_state(ep_p);
                cy_as_hal_sleep_on(&ep_p->channel, 10);

                /* If we timed out, the sleep bit will still be set */
                cy_as_dma_end_point_set_wake_state(ep_p);

                /* Check the queue to see if is drained */
                if (ep_p->queue_p == 0) {
                        /*
                         * clear the endpoint running and in transit flags
                         * for the endpoint, now that its DMA queue is empty.
                         */
                        cy_as_dma_end_point_clear_in_transit(ep_p);
                        cy_as_dma_end_point_set_stopped(ep_p);

                        cy_as_dma_enable_end_point(dev_p, ep,
                                cy_true, cy_as_direction_dont_change);
                        return CY_AS_ERROR_SUCCESS;
                }
        }

        /*
         * the DMA operation that has timed out can be cancelled, so that later
         * operations on this queue can proceed.
         */
        cy_as_dma_cancel(dev_p, ep, CY_AS_ERROR_TIMEOUT);
        cy_as_dma_enable_end_point(dev_p, ep,
                cy_true, cy_as_direction_dont_change);
        return CY_AS_ERROR_TIMEOUT;
}

/*
* This function queues a write request in the DMA queue
* for a given endpoint.  The direction of the
* entry will be inferred from the endpoint direction.
*/
cy_as_return_status_t
cy_as_dma_queue_request(cy_as_device *dev_p,
        cy_as_end_point_number_t ep, void *mem_p,
        uint32_t size, cy_bool pkt, cy_bool readreq, cy_as_dma_callback cb)
{
        uint32_t mask;
        cy_as_dma_queue_entry *entry_p;
        cy_as_dma_end_point *ep_p;

        /*
        * make sure the endpoint is valid
        */
        if (ep >= sizeof(dev_p->endp)/sizeof(dev_p->endp[0]))
                return CY_AS_ERROR_INVALID_ENDPOINT;

        /* Get the endpoint pointer based on the endpoint number */
        ep_p = CY_AS_NUM_EP(dev_p, ep);

        if (!cy_as_dma_end_point_is_enabled(ep_p))
                return CY_AS_ERROR_ENDPOINT_DISABLED;

        entry_p = cy_as_dma_get_dma_queue_entry(dev_p);

        entry_p->buf_p = mem_p;
        entry_p->cb = cb;
        entry_p->size = size;
        entry_p->offset = 0;
        entry_p->packet = pkt;
        entry_p->readreq = readreq;

        mask = cy_as_hal_disable_interrupts();
        entry_p->next_p = 0;
        if (ep_p->last_p)
                ep_p->last_p->next_p = entry_p;
        ep_p->last_p = entry_p;
        if (ep_p->queue_p == 0)
                ep_p->queue_p = entry_p;
        cy_as_hal_enable_interrupts(mask);

        return CY_AS_ERROR_SUCCESS;
}

/*
* This function enables or disables and endpoint for DMA
* queueing.  If an endpoint is disabled, any queue requests
* continue to be processed, but no new requests can be queued.
*/
cy_as_return_status_t
cy_as_dma_enable_end_point(cy_as_device *dev_p,
        cy_as_end_point_number_t ep, cy_bool enable, cy_as_dma_direction dir)
{
        cy_as_dma_end_point *ep_p;

        /*
        * make sure the endpoint is valid
        */
        if (ep >= sizeof(dev_p->endp)/sizeof(dev_p->endp[0]))
                return CY_AS_ERROR_INVALID_ENDPOINT;

        /* Get the endpoint pointer based on the endpoint number */
        ep_p = CY_AS_NUM_EP(dev_p, ep);

        if (dir == cy_as_direction_out)
                cy_as_dma_end_point_set_direction_out(ep_p);
        else if (dir == cy_as_direction_in)
                cy_as_dma_end_point_set_direction_in(ep_p);

        /*
        * get the maximum size of data buffer the HAL
        * layer can accept.  this is used when the DMA
        * module is sending DMA requests to the HAL.
        * the DMA module will never send down a request
        * that is greater than this value.
        *
        * for EP0 and EP1, we can send no more than 64
        * bytes of data at one time as this is the maximum
        * size of a packet that can be sent via these
        * endpoints.
        */
        if (ep == 0 || ep == 1)
                ep_p->maxhaldata = 64;
        else
                ep_p->maxhaldata = cy_as_hal_dma_max_request_size(
                                                dev_p->tag, ep);

        if (enable)
                cy_as_dma_end_point_enable(ep_p);
        else
                cy_as_dma_end_point_disable(ep_p);

        return CY_AS_ERROR_SUCCESS;
}

/*
 * This function cancels any DMA operations pending with the HAL layer as well
 * as any DMA operation queued on the endpoint.
 */
cy_as_return_status_t
cy_as_dma_cancel(
        cy_as_device *dev_p,
        cy_as_end_point_number_t ep,
        cy_as_return_status_t err)
{
        uint32_t mask;
        cy_as_dma_end_point *ep_p;
        cy_as_dma_queue_entry *entry_p;
        cy_bool epstate;

        /*
         * make sure the endpoint is valid
         */
        if (ep >= sizeof(dev_p->endp)/sizeof(dev_p->endp[0]))
                return CY_AS_ERROR_INVALID_ENDPOINT;

        /* Get the endpoint pointer based on the endpoint number */
        ep_p = CY_AS_NUM_EP(dev_p, ep);

        if (ep_p) {
                /* Remember the state of the endpoint */
                epstate = cy_as_dma_end_point_is_enabled(ep_p);

                /*
                 * disable the endpoint so no more DMA packets can be
                 * queued.
                 */
                cy_as_dma_enable_end_point(dev_p, ep,
                        cy_false, cy_as_direction_dont_change);

                /*
                 * don't allow any interrupts from this endpoint
                 * while we get the most current request off of
                 * the queue.
                 */
                cy_as_dma_set_drq(dev_p, ep, cy_false);

                /*
                 * cancel any pending request queued in the HAL layer
                 */
                if (cy_as_dma_end_point_in_transit(ep_p))
                        cy_as_hal_dma_cancel_request(dev_p->tag, ep_p->ep);

                /*
                 * shutdown the DMA for this endpoint so no
                 * more data is transferred
                 */
                cy_as_dma_end_point_set_stopped(ep_p);

                /*
                 * mark the endpoint as not in transit, because we are
                 * going to consume any queued requests
                 */
                cy_as_dma_end_point_clear_in_transit(ep_p);

                /*
                 * now, remove each entry in the queue and call the
                 * associated callback stating that the request was
                 * canceled.
                 */
                ep_p->last_p = 0;
                while (ep_p->queue_p != 0) {
                        /* Disable interrupts to manipulate the queue */
                        mask = cy_as_hal_disable_interrupts();

                        /* Remove an entry from the queue */
                        entry_p = ep_p->queue_p;
                        ep_p->queue_p = entry_p->next_p;

                        /* Ok, the queue has been updated, we can
                         * turn interrupts back on */
                        cy_as_hal_enable_interrupts(mask);

                        /* Call the callback indicating we have
                         * canceled the DMA */
                        if (entry_p->cb)
                                entry_p->cb(dev_p, ep,
                                        entry_p->buf_p, entry_p->size, err);

                        cy_as_dma_add_request_to_free_queue(dev_p, entry_p);
                }

                if (ep == 0 || ep == 1) {
                        /*
                         * if this endpoint is zero or one, we need to
                         * clear the queue of any pending CY_RQT_USB_EP_DATA
                         * requests as these are pending requests to send
                         * data to the west bridge device.
                         */
                        cy_as_ll_remove_ep_data_requests(dev_p, ep);
                }

                if (epstate) {
                        /*
                         * the endpoint started out enabled, so we
                         * re-enable the endpoint here.
                         */
                        cy_as_dma_enable_end_point(dev_p, ep,
                                cy_true, cy_as_direction_dont_change);
                }
        }

        return CY_AS_ERROR_SUCCESS;
}

cy_as_return_status_t
cy_as_dma_received_data(cy_as_device *dev_p,
        cy_as_end_point_number_t ep, uint32_t dsize, void *data)
{
        cy_as_dma_queue_entry *dma_p;
        uint8_t *src_p, *dest_p;
        cy_as_dma_end_point *ep_p;
        uint32_t xfersize;

        /*
         * make sure the endpoint is valid
         */
        if (ep != 0 && ep != 1)
                return CY_AS_ERROR_INVALID_ENDPOINT;

        /* Get the endpoint pointer based on the endpoint number */
        ep_p = CY_AS_NUM_EP(dev_p, ep);
        dma_p = ep_p->queue_p;
        if (dma_p == 0)
                return CY_AS_ERROR_SUCCESS;

        /*
         * if the data received exceeds the size of the DMA buffer,
         * clip the data to the size of the buffer.  this can lead
         * to losing some data, but is not different than doing
         * non-packet reads on the other endpoints.
         */
        if (dsize > dma_p->size - dma_p->offset)
                dsize = dma_p->size - dma_p->offset;

        /*
         * copy the data from the request packet to the DMA buffer
         * for the endpoint
         */
        src_p = (uint8_t *)data;
        dest_p = ((uint8_t *)(dma_p->buf_p)) + dma_p->offset;
        xfersize = dsize;
        while (xfersize-- > 0)
                *dest_p++ = *src_p++;

        /* Signal the DMA module that we have
         * received data for this EP request */
        cy_as_dma_completed_callback(dev_p->tag,
                ep, dsize, CY_AS_ERROR_SUCCESS);

        return CY_AS_ERROR_SUCCESS;
}