/* Cypress West Bridge API source file (cyaslowlevel.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/cyascast.h"
#include "../../include/linux/westbridge/cyasdevice.h"
#include "../../include/linux/westbridge/cyaslowlevel.h"
#include "../../include/linux/westbridge/cyasintr.h"
#include "../../include/linux/westbridge/cyaserr.h"
#include "../../include/linux/westbridge/cyasregs.h"

static const uint32_t cy_as_low_level_timeout_count = 65536 * 4;

/* Forward declaration */
static cy_as_return_status_t cy_as_send_one(cy_as_device *dev_p,
        cy_as_ll_request_response *req_p);

/*
* This array holds the size of the largest request we will ever recevie from
* the West Bridge device per context.  The size is in 16 bit words.  Note a
* size of 0xffff indicates that there will be no requests on this context
* from West Bridge.
*/
static uint16_t max_request_length[CY_RQT_CONTEXT_COUNT] = {
        8, /* CY_RQT_GENERAL_RQT_CONTEXT - CY_RQT_INITIALIZATION_COMPLETE */
        8, /* CY_RQT_RESOURCE_RQT_CONTEXT - none */
        8, /* CY_RQT_STORAGE_RQT_CONTEXT - CY_RQT_MEDIA_CHANGED */
        128, /* CY_RQT_USB_RQT_CONTEXT - CY_RQT_USB_EVENT */
        8 /* CY_RQT_TUR_RQT_CONTEXT - CY_RQT_TURBO_CMD_FROM_HOST */
};

/*
* For the given context, this function removes the request node at the head
* of the queue from the context.  This is called after all processing has
* occurred on the given request and response and we are ready to remove this
* entry from the queue.
*/
static void
cy_as_ll_remove_request_queue_head(cy_as_device *dev_p, cy_as_context *ctxt_p)
{
        uint32_t mask, state;
        cy_as_ll_request_list_node *node_p;

        (void)dev_p;
        cy_as_hal_assert(ctxt_p->request_queue_p != 0);

        mask = cy_as_hal_disable_interrupts();
        node_p = ctxt_p->request_queue_p;
        ctxt_p->request_queue_p = node_p->next;
        cy_as_hal_enable_interrupts(mask);

        node_p->callback = 0;
        node_p->rqt = 0;
        node_p->resp = 0;

        /*
        * note that the caller allocates and destroys the request and
        * response.  generally the destroy happens in the callback for
        * async requests and after the wait returns for sync.  the
        * request and response may not actually be destroyed but may be
        * managed in other ways as well.  it is the responsibilty of
        * the caller to deal with these in any case.  the caller can do
        * this in the request/response callback function.
        */
        state = cy_as_hal_disable_interrupts();
        cy_as_hal_c_b_free(node_p);
        cy_as_hal_enable_interrupts(state);
}

/*
* For the context given, this function sends the next request to
* West Bridge via the mailbox register, if the next request is
* ready to be sent and has not already been sent.
*/
static void
cy_as_ll_send_next_request(cy_as_device *dev_p, cy_as_context *ctxt_p)
{
        cy_as_return_status_t ret = CY_AS_ERROR_SUCCESS;

        /*
        * ret == ret is equivalent to while (1) but eliminates compiler
        * warnings for some compilers.
        */
        while (ret == ret) {
                cy_as_ll_request_list_node *node_p = ctxt_p->request_queue_p;
                if (node_p == 0)
                        break;

                if (cy_as_request_get_node_state(node_p) !=
                        CY_AS_REQUEST_LIST_STATE_QUEUED)
                        break;

                cy_as_request_set_node_state(node_p,
                        CY_AS_REQUEST_LIST_STATE_WAITING);
                ret = cy_as_send_one(dev_p, node_p->rqt);
                if (ret == CY_AS_ERROR_SUCCESS)
                        break;

                /*
                * if an error occurs in sending the request, tell the requester
                * about the error and remove the request from the queue.
                */
                cy_as_request_set_node_state(node_p,
                        CY_AS_REQUEST_LIST_STATE_RECEIVED);
                node_p->callback(dev_p, ctxt_p->number,
                        node_p->rqt, node_p->resp, ret);
                cy_as_ll_remove_request_queue_head(dev_p, ctxt_p);

                /*
                * this falls through to the while loop to send the next request
                * since the previous request did not get sent.
                */
        }
}

/*
* This method removes an entry from the request queue of a given context.
* The entry is removed only if it is not in transit.
*/
cy_as_remove_request_result_t
cy_as_ll_remove_request(cy_as_device *dev_p, cy_as_context *ctxt_p,
        cy_as_ll_request_response *req_p, cy_bool force)
{
        uint32_t imask;
        cy_as_ll_request_list_node *node_p;
        cy_as_ll_request_list_node *tmp_p;
        uint32_t state;

        imask = cy_as_hal_disable_interrupts();
        if (ctxt_p->request_queue_p != 0 &&
                ctxt_p->request_queue_p->rqt == req_p) {
                node_p = ctxt_p->request_queue_p;
                if ((cy_as_request_get_node_state(node_p) ==
                        CY_AS_REQUEST_LIST_STATE_WAITING) && (!force)) {
                        cy_as_hal_enable_interrupts(imask);
                        return cy_as_remove_request_in_transit;
                }

                ctxt_p->request_queue_p = node_p->next;
        } else {
                tmp_p = ctxt_p->request_queue_p;
                while (tmp_p != 0 && tmp_p->next != 0 &&
                        tmp_p->next->rqt != req_p)
                        tmp_p = tmp_p->next;

                if (tmp_p == 0 || tmp_p->next == 0) {
                        cy_as_hal_enable_interrupts(imask);
                        return cy_as_remove_request_not_found;
                }

                node_p = tmp_p->next;
                tmp_p->next = node_p->next;
        }

        if (node_p->callback)
                node_p->callback(dev_p, ctxt_p->number, node_p->rqt,
                        node_p->resp, CY_AS_ERROR_CANCELED);

        state = cy_as_hal_disable_interrupts();
        cy_as_hal_c_b_free(node_p);
        cy_as_hal_enable_interrupts(state);

        cy_as_hal_enable_interrupts(imask);
        return cy_as_remove_request_sucessful;
}

void
cy_as_ll_remove_all_requests(cy_as_device *dev_p, cy_as_context *ctxt_p)
{
        cy_as_ll_request_list_node *node = ctxt_p->request_queue_p;

        while (node) {
                if (cy_as_request_get_node_state(ctxt_p->request_queue_p) !=
                        CY_AS_REQUEST_LIST_STATE_RECEIVED)
                        cy_as_ll_remove_request(dev_p, ctxt_p,
                                node->rqt, cy_true);
                node = node->next;
        }
}

static cy_bool
cy_as_ll_is_in_queue(cy_as_context *ctxt_p, cy_as_ll_request_response *req_p)
{
        uint32_t mask;
        cy_as_ll_request_list_node *node_p;

        mask = cy_as_hal_disable_interrupts();
        node_p = ctxt_p->request_queue_p;
        while (node_p) {
                if (node_p->rqt == req_p) {
                        cy_as_hal_enable_interrupts(mask);
                        return cy_true;
                }
                node_p = node_p->next;
        }
        cy_as_hal_enable_interrupts(mask);
        return cy_false;
}

/*
* This is the handler for mailbox data when we are trying to send data
* to the West Bridge firmware.  The firmware may be trying to send us
* data and we need to queue this data to allow the firmware to move
* forward and be in a state to receive our request.  Here we just queue
* the data and it is processed at a later time by the mailbox interrupt
* handler.
*/
void
cy_as_ll_queue_mailbox_data(cy_as_device *dev_p)
{
        cy_as_context *ctxt_p;
        uint8_t context;
        uint16_t data[4];
        int32_t i;

        /* Read the data from mailbox 0 to determine what to do with the data */
        for (i = 3; i >= 0; i--)
                data[i] = cy_as_hal_read_register(dev_p->tag,
                        cy_cast_int2U_int16(CY_AS_MEM_P0_MAILBOX0 + i));

        context = cy_as_mbox_get_context(data[0]);
        if (context >= CY_RQT_CONTEXT_COUNT) {
                cy_as_hal_print_message("mailbox request/response received "
                        "with invalid context value (%d)\n", context);
                return;
        }

        ctxt_p = dev_p->context[context];

        /*
        * if we have queued too much data, drop future data.
        */
        cy_as_hal_assert(ctxt_p->queue_index * sizeof(uint16_t) +
                sizeof(data) <= sizeof(ctxt_p->data_queue));

        for (i = 0; i < 4; i++)
                ctxt_p->data_queue[ctxt_p->queue_index++] = data[i];

        cy_as_hal_assert((ctxt_p->queue_index % 4) == 0);
        dev_p->ll_queued_data = cy_true;
}

void
cy_as_mail_box_process_data(cy_as_device *dev_p, uint16_t *data)
{
        cy_as_context *ctxt_p;
        uint8_t context;
        uint16_t *len_p;
        cy_as_ll_request_response *rec_p;
        uint8_t st;
        uint16_t src, dest;

        context = cy_as_mbox_get_context(data[0]);
        if (context >= CY_RQT_CONTEXT_COUNT) {
                cy_as_hal_print_message("mailbox request/response received "
                "with invalid context value (%d)\n", context);
                return;
        }

        ctxt_p = dev_p->context[context];

        if (cy_as_mbox_is_request(data[0])) {
                cy_as_hal_assert(ctxt_p->req_p != 0);
                rec_p = ctxt_p->req_p;
                len_p = &ctxt_p->request_length;

        } else {
                if (ctxt_p->request_queue_p == 0 ||
                        cy_as_request_get_node_state(ctxt_p->request_queue_p)
                        != CY_AS_REQUEST_LIST_STATE_WAITING) {
                        cy_as_hal_print_message("mailbox response received on "
                                "context that was not expecting a response\n");
                        cy_as_hal_print_message("  context: %d\n", context);
                        cy_as_hal_print_message("  contents: 0x%04x 0x%04x "
                                "0x%04x 0x%04x\n",
                                data[0], data[1], data[2], data[3]);
                        if (ctxt_p->request_queue_p != 0)
                                cy_as_hal_print_message("  state: 0x%02x\n",
                                        ctxt_p->request_queue_p->state);
                        return;
                }

                /* Make sure the request has an associated response */
                cy_as_hal_assert(ctxt_p->request_queue_p->resp != 0);

                rec_p = ctxt_p->request_queue_p->resp;
                len_p = &ctxt_p->request_queue_p->length;
        }

        if (rec_p->stored == 0) {
                /*
                * this is the first cycle of the response
                */
                cy_as_ll_request_response__set_code(rec_p,
                        cy_as_mbox_get_code(data[0]));
                cy_as_ll_request_response__set_context(rec_p, context);

                if (cy_as_mbox_is_last(data[0])) {
                        /* This is a single cycle response */
                        *len_p = rec_p->length;
                        st = 1;
                } else {
                        /* Ensure that enough memory has been
                         * reserved for the response. */
                        cy_as_hal_assert(rec_p->length >= data[1]);
                        *len_p = (data[1] < rec_p->length) ?
                                data[1] : rec_p->length;
                        st = 2;
                }
        } else
                st = 1;

        /* Trasnfer the data from the mailboxes to the response */
        while (rec_p->stored < *len_p && st < 4)
                rec_p->data[rec_p->stored++] = data[st++];

        if (cy_as_mbox_is_last(data[0])) {
                /* NB: The call-back that is made below can cause the
                 * addition of more data in this queue, thus causing
                 * a recursive overflow of the queue. this is prevented
                 * by removing the request entry that is currently
                 * being passed up from the data queue. if this is done,
                 * the queue only needs to be as long as two request
                 * entries from west bridge.
                */
                if ((ctxt_p->rqt_index > 0) &&
                        (ctxt_p->rqt_index <= ctxt_p->queue_index)) {
                        dest = 0;
                        src  = ctxt_p->rqt_index;

                        while (src < ctxt_p->queue_index)
                                ctxt_p->data_queue[dest++] =
                                        ctxt_p->data_queue[src++];

                        ctxt_p->rqt_index = 0;
                        ctxt_p->queue_index = dest;
                        cy_as_hal_assert((ctxt_p->queue_index % 4) == 0);
                }

                if (ctxt_p->request_queue_p != 0 && rec_p ==
                        ctxt_p->request_queue_p->resp) {
                        /*
                        * if this is the last cycle of the response, call the
                        * callback and reset for the next response.
                        */
                        cy_as_ll_request_response *resp_p =
                                ctxt_p->request_queue_p->resp;
                        resp_p->length = ctxt_p->request_queue_p->length;
                        cy_as_request_set_node_state(ctxt_p->request_queue_p,
                                CY_AS_REQUEST_LIST_STATE_RECEIVED);

                        cy_as_device_set_in_callback(dev_p);
                        ctxt_p->request_queue_p->callback(dev_p, context,
                                ctxt_p->request_queue_p->rqt,
                                resp_p, CY_AS_ERROR_SUCCESS);

                        cy_as_device_clear_in_callback(dev_p);

                        cy_as_ll_remove_request_queue_head(dev_p, ctxt_p);
                        cy_as_ll_send_next_request(dev_p, ctxt_p);
                } else {
                        /* Send the request to the appropriate
                         * module to handle */
                        cy_as_ll_request_response *request_p = ctxt_p->req_p;
                        ctxt_p->req_p = 0;
                        if (ctxt_p->request_callback) {
                                cy_as_device_set_in_callback(dev_p);
                                ctxt_p->request_callback(dev_p, context,
                                        request_p, 0, CY_AS_ERROR_SUCCESS);
                                cy_as_device_clear_in_callback(dev_p);
                        }
                        cy_as_ll_init_request(request_p, 0,
                                context, request_p->length);
                        ctxt_p->req_p = request_p;
                }
        }
}

/*
* This is the handler for processing queued mailbox data
*/
void
cy_as_mail_box_queued_data_handler(cy_as_device *dev_p)
{
        uint16_t i;

        /*
         * if more data gets queued in between our entering this call
         * and the end of the iteration on all contexts; we should
         * continue processing the queued data.
         */
        while (dev_p->ll_queued_data) {
                dev_p->ll_queued_data = cy_false;
                for (i = 0; i < CY_RQT_CONTEXT_COUNT; i++) {
                        uint16_t offset;
                        cy_as_context *ctxt_p = dev_p->context[i];
                        cy_as_hal_assert((ctxt_p->queue_index % 4) == 0);

                        offset = 0;
                        while (offset < ctxt_p->queue_index) {
                                ctxt_p->rqt_index = offset + 4;
                                cy_as_mail_box_process_data(dev_p,
                                        ctxt_p->data_queue + offset);
                                offset = ctxt_p->rqt_index;
                        }
                        ctxt_p->queue_index = 0;
                }
        }
}

/*
* This is the handler for the mailbox interrupt.  This function reads
* data from the mailbox registers until a complete request or response
* is received.  When a complete request is received, the callback
* associated with requests on that context is called.  When a complete
* response is recevied, the callback associated with the request that
* generated the reponse is called.
*/
void
cy_as_mail_box_interrupt_handler(cy_as_device *dev_p)
{
        cy_as_hal_assert(dev_p->sig == CY_AS_DEVICE_HANDLE_SIGNATURE);

        /*
        * queue the mailbox data to preserve
        * order for later processing.
        */
        cy_as_ll_queue_mailbox_data(dev_p);

        /*
        * process what was queued and anything that may be pending
        */
        cy_as_mail_box_queued_data_handler(dev_p);
}

cy_as_return_status_t
cy_as_ll_start(cy_as_device *dev_p)
{
        uint16_t i;

        if (cy_as_device_is_low_level_running(dev_p))
                return CY_AS_ERROR_ALREADY_RUNNING;

        dev_p->ll_sending_rqt = cy_false;
        dev_p->ll_abort_curr_rqt = cy_false;

        for (i = 0; i < CY_RQT_CONTEXT_COUNT; i++) {
                dev_p->context[i] = (cy_as_context *)
                        cy_as_hal_alloc(sizeof(cy_as_context));
                if (dev_p->context[i] == 0)
                        return CY_AS_ERROR_OUT_OF_MEMORY;

                dev_p->context[i]->number = (uint8_t)i;
                dev_p->context[i]->request_callback = 0;
                dev_p->context[i]->request_queue_p = 0;
                dev_p->context[i]->last_node_p = 0;
                dev_p->context[i]->req_p = cy_as_ll_create_request(dev_p,
                        0, (uint8_t)i, max_request_length[i]);
                dev_p->context[i]->queue_index = 0;

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

        cy_as_device_set_low_level_running(dev_p);
        return CY_AS_ERROR_SUCCESS;
}

/*
* Shutdown the low level communications module.  This operation will
* also cancel any queued low level requests.
*/
cy_as_return_status_t
cy_as_ll_stop(cy_as_device *dev_p)
{
        uint8_t i;
        cy_as_return_status_t ret = CY_AS_ERROR_SUCCESS;
        cy_as_context *ctxt_p;
        uint32_t mask;

        for (i = 0; i < CY_RQT_CONTEXT_COUNT; i++) {
                ctxt_p = dev_p->context[i];
                if (!cy_as_hal_destroy_sleep_channel(&ctxt_p->channel))
                        return CY_AS_ERROR_DESTROY_SLEEP_CHANNEL_FAILED;

                /*
                * now, free any queued requests and assocaited responses
                */
                while (ctxt_p->request_queue_p) {
                        uint32_t state;
                        cy_as_ll_request_list_node *node_p =
                                ctxt_p->request_queue_p;

                        /* Mark this pair as in a cancel operation */
                        cy_as_request_set_node_state(node_p,
                                CY_AS_REQUEST_LIST_STATE_CANCELING);

                        /* Tell the caller that we are canceling this request */
                        /* NB: The callback is responsible for destroying the
                         * request and the response.  we cannot count on the
                         * contents of these two after calling the callback.
                        */
                        node_p->callback(dev_p, i, node_p->rqt,
                                node_p->resp, CY_AS_ERROR_CANCELED);

                        /* Remove the pair from the queue */
                        mask = cy_as_hal_disable_interrupts();
                        ctxt_p->request_queue_p = node_p->next;
                        cy_as_hal_enable_interrupts(mask);

                        /* Free the list node */
                        state = cy_as_hal_disable_interrupts();
                        cy_as_hal_c_b_free(node_p);
                        cy_as_hal_enable_interrupts(state);
                }

                cy_as_ll_destroy_request(dev_p, dev_p->context[i]->req_p);
                cy_as_hal_free(dev_p->context[i]);
                dev_p->context[i] = 0;

        }
        cy_as_device_set_low_level_stopped(dev_p);

        return ret;
}

void
cy_as_ll_init_request(cy_as_ll_request_response *req_p,
        uint16_t code, uint16_t context, uint16_t length)
{
        uint16_t totallen = sizeof(cy_as_ll_request_response) +
                (length - 1) * sizeof(uint16_t);

        cy_as_hal_mem_set(req_p, 0, totallen);
        req_p->length = length;
        cy_as_ll_request_response__set_code(req_p, code);
        cy_as_ll_request_response__set_context(req_p, context);
        cy_as_ll_request_response__set_request(req_p);
}

/*
* Create a new request.
*/
cy_as_ll_request_response *
cy_as_ll_create_request(cy_as_device *dev_p, uint16_t code,
        uint8_t context, uint16_t length)
{
        cy_as_ll_request_response *req_p;
        uint32_t state;
        uint16_t totallen = sizeof(cy_as_ll_request_response) +
                (length - 1) * sizeof(uint16_t);

        (void)dev_p;

        state = cy_as_hal_disable_interrupts();
        req_p = cy_as_hal_c_b_alloc(totallen);
        cy_as_hal_enable_interrupts(state);
        if (req_p)
                cy_as_ll_init_request(req_p, code, context, length);

        return req_p;
}

/*
* Destroy a request.
*/
void
cy_as_ll_destroy_request(cy_as_device *dev_p, cy_as_ll_request_response *req_p)
{
        uint32_t state;
        (void)dev_p;
        (void)req_p;

        state = cy_as_hal_disable_interrupts();
        cy_as_hal_c_b_free(req_p);
        cy_as_hal_enable_interrupts(state);

}

void
cy_as_ll_init_response(cy_as_ll_request_response *req_p, uint16_t length)
{
        uint16_t totallen = sizeof(cy_as_ll_request_response) +
                (length - 1) * sizeof(uint16_t);

        cy_as_hal_mem_set(req_p, 0, totallen);
        req_p->length = length;
        cy_as_ll_request_response__set_response(req_p);
}

/*
* Create a new response
*/
cy_as_ll_request_response *
cy_as_ll_create_response(cy_as_device *dev_p, uint16_t length)
{
        cy_as_ll_request_response *req_p;
        uint32_t state;
        uint16_t totallen = sizeof(cy_as_ll_request_response) +
                (length - 1) * sizeof(uint16_t);

        (void)dev_p;

        state = cy_as_hal_disable_interrupts();
        req_p = cy_as_hal_c_b_alloc(totallen);
        cy_as_hal_enable_interrupts(state);
        if (req_p)
                cy_as_ll_init_response(req_p, length);

        return req_p;
}

/*
* Destroy the new response
*/
void
cy_as_ll_destroy_response(cy_as_device *dev_p, cy_as_ll_request_response *req_p)
{
        uint32_t state;
        (void)dev_p;
        (void)req_p;

        state = cy_as_hal_disable_interrupts();
        cy_as_hal_c_b_free(req_p);
        cy_as_hal_enable_interrupts(state);
}

static uint16_t
cy_as_read_intr_status(
                                   cy_as_device *dev_p)
{
        uint32_t mask;
        cy_bool bloop = cy_true;
        uint16_t v = 0, last = 0xffff;

        /*
        * before determining if the mailboxes are ready for more data,
        * we first check the mailbox interrupt to see if we need to
        * receive data.  this prevents a dead-lock condition that can
        * occur when both sides are trying to receive data.
        */
        while (last == last) {
                /*
                * disable interrupts to be sure we don't process the mailbox
                * here and have the interrupt routine try to read this data
                * as well.
                */
                mask = cy_as_hal_disable_interrupts();

                /*
                * see if there is data to be read.
                */
                v = cy_as_hal_read_register(dev_p->tag, CY_AS_MEM_P0_INTR_REG);
                if ((v & CY_AS_MEM_P0_INTR_REG_MBINT) == 0) {
                        cy_as_hal_enable_interrupts(mask);
                        break;
                }

                /*
                * queue the mailbox data for later processing.
                * this allows the firmware to move forward and
                * service the requst from the P port.
                */
                cy_as_ll_queue_mailbox_data(dev_p);

                /*
                * enable interrupts again to service mailbox
                * interrupts appropriately
                */
                cy_as_hal_enable_interrupts(mask);
        }

        /*
        * now, all data is received
        */
        last = cy_as_hal_read_register(dev_p->tag,
                CY_AS_MEM_MCU_MB_STAT) & CY_AS_MEM_P0_MCU_MBNOTRD;
        while (bloop) {
                v = cy_as_hal_read_register(dev_p->tag,
                CY_AS_MEM_MCU_MB_STAT) & CY_AS_MEM_P0_MCU_MBNOTRD;
                if (v == last)
                        break;

                last = v;
        }

        return v;
}

/*
* Send a single request or response using the mail box register.
* This function does not deal with the internal queues at all,
* but only sends the request or response across to the firmware
*/
static cy_as_return_status_t
cy_as_send_one(
                        cy_as_device *dev_p,
                        cy_as_ll_request_response *req_p)
{
        int i;
        uint16_t mb0, v;
        int32_t loopcount;
        uint32_t int_stat;

#ifdef _DEBUG
        if (cy_as_ll_request_response__is_request(req_p)) {
                switch (cy_as_ll_request_response__get_context(req_p)) {
                case CY_RQT_GENERAL_RQT_CONTEXT:
                        cy_as_hal_assert(req_p->length * 2 + 2 <
                                CY_CTX_GEN_MAX_DATA_SIZE);
                        break;

                case CY_RQT_RESOURCE_RQT_CONTEXT:
                        cy_as_hal_assert(req_p->length * 2 + 2 <
                                CY_CTX_RES_MAX_DATA_SIZE);
                        break;

                case CY_RQT_STORAGE_RQT_CONTEXT:
                        cy_as_hal_assert(req_p->length * 2 + 2 <
                                CY_CTX_STR_MAX_DATA_SIZE);
                        break;

                case CY_RQT_USB_RQT_CONTEXT:
                        cy_as_hal_assert(req_p->length * 2 + 2 <
                                CY_CTX_USB_MAX_DATA_SIZE);
                        break;
                }
        }
#endif

        /* Write the request to the mail box registers */
        if (req_p->length > 3) {
                uint16_t length = req_p->length;
                int which = 0;
                int st = 1;

                dev_p->ll_sending_rqt = cy_true;
                while (which < length) {
                        loopcount = cy_as_low_level_timeout_count;
                        do {
                                v = cy_as_read_intr_status(dev_p);

                        } while (v && loopcount-- > 0);

                        if (v) {
                                cy_as_hal_print_message(
                                        ">>>>>> LOW LEVEL TIMEOUT "
                                        "%x %x %x %x\n",
                                        cy_as_hal_read_register(dev_p->tag,
                                                CY_AS_MEM_MCU_MAILBOX0),
                                        cy_as_hal_read_register(dev_p->tag,
                                                CY_AS_MEM_MCU_MAILBOX1),
                                        cy_as_hal_read_register(dev_p->tag,
                                                CY_AS_MEM_MCU_MAILBOX2),
                                        cy_as_hal_read_register(dev_p->tag,
                                                CY_AS_MEM_MCU_MAILBOX3));
                                return CY_AS_ERROR_TIMEOUT;
                        }

                        if (dev_p->ll_abort_curr_rqt) {
                                dev_p->ll_sending_rqt = cy_false;
                                dev_p->ll_abort_curr_rqt = cy_false;
                                return CY_AS_ERROR_CANCELED;
                        }

                        int_stat = cy_as_hal_disable_interrupts();

                        /*
                         * check again whether the mailbox is free.
                         * it is possible that an ISR came in and
                         * wrote into the mailboxes since we last
                         * checked the status.
                         */
                        v = cy_as_hal_read_register(dev_p->tag,
                                CY_AS_MEM_MCU_MB_STAT) &
                                CY_AS_MEM_P0_MCU_MBNOTRD;
                        if (v) {
                                /* Go back to the original check since
                                 * the mailbox is not free. */
                                cy_as_hal_enable_interrupts(int_stat);
                                continue;
                        }

                        if (which == 0) {
                                cy_as_hal_write_register(dev_p->tag,
                                        CY_AS_MEM_MCU_MAILBOX1, length);
                                st = 2;
                        } else {
                                st = 1;
                        }

                        while ((which < length) && (st < 4)) {
                                cy_as_hal_write_register(dev_p->tag,
                                        cy_cast_int2U_int16
                                                (CY_AS_MEM_MCU_MAILBOX0 + st),
                                                req_p->data[which++]);
                                st++;
                        }

                        mb0 = req_p->box0;
                        if (which == length) {
                                dev_p->ll_sending_rqt = cy_false;
                                mb0 |= CY_AS_REQUEST_RESPONSE_LAST_MASK;
                        }

                        if (dev_p->ll_abort_curr_rqt) {
                                dev_p->ll_sending_rqt = cy_false;
                                dev_p->ll_abort_curr_rqt = cy_false;
                                cy_as_hal_enable_interrupts(int_stat);
                                return CY_AS_ERROR_CANCELED;
                        }

                        cy_as_hal_write_register(dev_p->tag,
                                CY_AS_MEM_MCU_MAILBOX0, mb0);

                        /* Wait for the MBOX interrupt to be high */
                        cy_as_hal_sleep150();
                        cy_as_hal_enable_interrupts(int_stat);
                }
        } else {
check_mailbox_availability:
                /*
                * wait for the mailbox registers to become available. this
                * should be a very quick wait as the firmware is designed
                * to accept requests at interrupt time and queue them for
                * future processing.
                */
                loopcount = cy_as_low_level_timeout_count;
                do {
                        v = cy_as_read_intr_status(dev_p);

                } while (v && loopcount-- > 0);

                if (v) {
                        cy_as_hal_print_message(
                                ">>>>>> LOW LEVEL TIMEOUT %x %x %x %x\n",
                                cy_as_hal_read_register(dev_p->tag,
                                        CY_AS_MEM_MCU_MAILBOX0),
                                cy_as_hal_read_register(dev_p->tag,
                                        CY_AS_MEM_MCU_MAILBOX1),
                                cy_as_hal_read_register(dev_p->tag,
                                        CY_AS_MEM_MCU_MAILBOX2),
                                cy_as_hal_read_register(dev_p->tag,
                                        CY_AS_MEM_MCU_MAILBOX3));
                        return CY_AS_ERROR_TIMEOUT;
                }

                int_stat = cy_as_hal_disable_interrupts();

                /*
                 * check again whether the mailbox is free. it is
                 * possible that an ISR came in and wrote into the
                 * mailboxes since we last checked the status.
                 */
                v = cy_as_hal_read_register(dev_p->tag, CY_AS_MEM_MCU_MB_STAT) &
                        CY_AS_MEM_P0_MCU_MBNOTRD;
                if (v) {
                        /* Go back to the original check
                         * since the mailbox is not free. */
                        cy_as_hal_enable_interrupts(int_stat);
                        goto check_mailbox_availability;
                }

                /* Write the data associated with the request
                 * into the mbox registers 1 - 3 */
                v = 0;
                for (i = req_p->length - 1; i >= 0; i--)
                        cy_as_hal_write_register(dev_p->tag,
                                cy_cast_int2U_int16(CY_AS_MEM_MCU_MAILBOX1 + i),
                                req_p->data[i]);

                /* Write the mbox register 0 to trigger the interrupt */
                cy_as_hal_write_register(dev_p->tag, CY_AS_MEM_MCU_MAILBOX0,
                        req_p->box0 | CY_AS_REQUEST_RESPONSE_LAST_MASK);

                cy_as_hal_sleep150();
                cy_as_hal_enable_interrupts(int_stat);
        }

        return CY_AS_ERROR_SUCCESS;
}

/*
* This function queues a single request to be sent to the firmware.
*/
extern cy_as_return_status_t
cy_as_ll_send_request(
                                  cy_as_device *dev_p,
                                  /* The request to send */
                                  cy_as_ll_request_response *req,
                                  /* Storage for a reply, must be sure
                                   * it is of sufficient size */
                                  cy_as_ll_request_response *resp,
                                  /* If true, this is a synchronous request */
                                  cy_bool sync,
                                  /* Callback to call when reply is received */
                                  cy_as_response_callback cb
)
{
        cy_as_context *ctxt_p;
        uint16_t box0 = req->box0;
        uint8_t context;
        cy_as_return_status_t ret = CY_AS_ERROR_SUCCESS;
        cy_as_ll_request_list_node *node_p;
        uint32_t mask, state;

        cy_as_hal_assert(dev_p->sig == CY_AS_DEVICE_HANDLE_SIGNATURE);

        context = cy_as_mbox_get_context(box0);
        cy_as_hal_assert(context < CY_RQT_CONTEXT_COUNT);
        ctxt_p = dev_p->context[context];

        /* Allocate the list node */
        state = cy_as_hal_disable_interrupts();
        node_p = cy_as_hal_c_b_alloc(sizeof(cy_as_ll_request_list_node));
        cy_as_hal_enable_interrupts(state);

        if (node_p == 0)
                return CY_AS_ERROR_OUT_OF_MEMORY;

        /* Initialize the list node */
        node_p->callback = cb;
        node_p->length = 0;
        node_p->next = 0;
        node_p->resp = resp;
        node_p->rqt = req;
        node_p->state = CY_AS_REQUEST_LIST_STATE_QUEUED;
        if (sync)
                cy_as_request_node_set_sync(node_p);

        /* Put the request into the queue */
        mask = cy_as_hal_disable_interrupts();
        if (ctxt_p->request_queue_p == 0) {
                /* Empty queue */
                ctxt_p->request_queue_p = node_p;
                ctxt_p->last_node_p = node_p;
        } else {
                ctxt_p->last_node_p->next = node_p;
                ctxt_p->last_node_p = node_p;
        }
        cy_as_hal_enable_interrupts(mask);
        cy_as_ll_send_next_request(dev_p, ctxt_p);

        if (!cy_as_device_is_in_callback(dev_p)) {
                mask = cy_as_hal_disable_interrupts();
                cy_as_mail_box_queued_data_handler(dev_p);
                cy_as_hal_enable_interrupts(mask);
        }

        return ret;
}

static void
cy_as_ll_send_callback(
                                   cy_as_device *dev_p,
                                   uint8_t context,
                                   cy_as_ll_request_response *rqt,
                                   cy_as_ll_request_response *resp,
                                   cy_as_return_status_t ret)
{
        (void)rqt;
        (void)resp;
        (void)ret;


        cy_as_hal_assert(dev_p->sig == CY_AS_DEVICE_HANDLE_SIGNATURE);

        /*
        * storage the state to return to the caller
        */
        dev_p->ll_error = ret;

        /*
        * now wake the caller
        */
        cy_as_hal_wake(&dev_p->context[context]->channel);
}

cy_as_return_status_t
cy_as_ll_send_request_wait_reply(
                cy_as_device *dev_p,

                /* The request to send */
                cy_as_ll_request_response *req,
                /* Storage for a reply, must be
                 * sure it is of sufficient size */
                cy_as_ll_request_response *resp
                )
{
        cy_as_return_status_t ret;
        uint8_t context;
        /* Larger 8 sec time-out to handle the init
         * delay for slower storage devices in USB FS. */
        uint32_t loopcount = 800;
        cy_as_context *ctxt_p;

        /* Get the context for the request */
        context = cy_as_ll_request_response__get_context(req);
        cy_as_hal_assert(context < CY_RQT_CONTEXT_COUNT);
        ctxt_p = dev_p->context[context];

        ret = cy_as_ll_send_request(dev_p, req, resp,
                cy_true, cy_as_ll_send_callback);
        if (ret != CY_AS_ERROR_SUCCESS)
                return ret;

        while (loopcount-- > 0) {
                /*
                * sleep while we wait on the response.  receiving the reply will
                * wake this thread.  we will wait, at most 2 seconds (10 ms*200
                * tries) before we timeout.  note if the reply arrives, we will
                * not sleep the entire 10 ms, just til the reply arrives.
                */
                cy_as_hal_sleep_on(&ctxt_p->channel, 10);

                /*
                * if the request has left the queue, it means the request has
                * been sent and the reply has been received.  this means we can
                * return to the caller and be sure the reply has been received.
                */
                if (!cy_as_ll_is_in_queue(ctxt_p, req))
                        return dev_p->ll_error;
        }

        /* Remove the QueueListNode for this request. */
        cy_as_ll_remove_request(dev_p, ctxt_p, req, cy_true);

        return CY_AS_ERROR_TIMEOUT;
}

cy_as_return_status_t
cy_as_ll_register_request_callback(
                        cy_as_device *dev_p,
                        uint8_t context,
                        cy_as_response_callback cb)
{
        cy_as_context *ctxt_p;
        cy_as_hal_assert(context < CY_RQT_CONTEXT_COUNT);
        ctxt_p = dev_p->context[context];

        ctxt_p->request_callback = cb;
        return CY_AS_ERROR_SUCCESS;
}

void
cy_as_ll_request_response__pack(
                        cy_as_ll_request_response *req_p,
                        uint32_t offset,
                        uint32_t length,
                        void *data_p)
{
        uint16_t dt;
        uint8_t *dp = (uint8_t *)data_p;

        while (length > 1) {
                dt = ((*dp++) << 8);
                dt |= (*dp++);
                cy_as_ll_request_response__set_word(req_p, offset, dt);
                offset++;
                length -= 2;
        }

        if (length == 1) {
                dt = (*dp << 8);
                cy_as_ll_request_response__set_word(req_p, offset, dt);
        }
}

void
cy_as_ll_request_response__unpack(
                        cy_as_ll_request_response *req_p,
                        uint32_t offset,
                        uint32_t length,
                        void *data_p)
{
        uint8_t *dp = (uint8_t *)data_p;

        while (length-- > 0) {
                uint16_t val = cy_as_ll_request_response__get_word
                        (req_p, offset++);
                *dp++ = (uint8_t)((val >> 8) & 0xff);

                if (length) {
                        length--;
                        *dp++ = (uint8_t)(val & 0xff);
                }
        }
}

extern cy_as_return_status_t
cy_as_ll_send_status_response(
                                                 cy_as_device *dev_p,
                                                 uint8_t context,
                                                 uint16_t code,
                                                 uint8_t clear_storage)
{
        cy_as_return_status_t ret;
        cy_as_ll_request_response resp;
        cy_as_ll_request_response *resp_p = &resp;

        cy_as_hal_mem_set(resp_p, 0, sizeof(resp));
        resp_p->length = 1;
        cy_as_ll_request_response__set_response(resp_p);
        cy_as_ll_request_response__set_context(resp_p, context);

        if (clear_storage)
                cy_as_ll_request_response__set_clear_storage_flag(resp_p);

        cy_as_ll_request_response__set_code(resp_p, CY_RESP_SUCCESS_FAILURE);
        cy_as_ll_request_response__set_word(resp_p, 0, code);

        ret = cy_as_send_one(dev_p, resp_p);

        return ret;
}

extern cy_as_return_status_t
cy_as_ll_send_data_response(
                                           cy_as_device *dev_p,
                                           uint8_t context,
                                           uint16_t code,
                                           uint16_t length,
                                           void *data)
{
        cy_as_ll_request_response *resp_p;
        uint16_t wlen;
        uint8_t respbuf[256];

        if (length > 192)
                return CY_AS_ERROR_INVALID_SIZE;

        /* Word length for bytes */
        wlen = length / 2;

        /* If byte length odd, add one more */
        if (length % 2)
                wlen++;

        /* One for the length of field */
        wlen++;

        resp_p = (cy_as_ll_request_response *)respbuf;
        cy_as_hal_mem_set(resp_p, 0, sizeof(respbuf));
        resp_p->length = wlen;
        cy_as_ll_request_response__set_context(resp_p, context);
        cy_as_ll_request_response__set_code(resp_p, code);

        cy_as_ll_request_response__set_word(resp_p, 0, length);
        cy_as_ll_request_response__pack(resp_p, 1, length, data);

        return cy_as_send_one(dev_p, resp_p);
}

static cy_bool
cy_as_ll_is_e_p_transfer_related_request(cy_as_ll_request_response *rqt_p,
        cy_as_end_point_number_t ep)
{
        uint16_t v;
        uint8_t  type = cy_as_ll_request_response__get_code(rqt_p);

        if (cy_as_ll_request_response__get_context(rqt_p) !=
                CY_RQT_USB_RQT_CONTEXT)
                return cy_false;

        /*
         * when cancelling outstanding EP0 data transfers, any pending
         * setup ACK requests also need to be cancelled.
         */
        if ((ep == 0) && (type == CY_RQT_ACK_SETUP_PACKET))
                return cy_true;

        if (type != CY_RQT_USB_EP_DATA)
                return cy_false;

        v = cy_as_ll_request_response__get_word(rqt_p, 0);
        if ((cy_as_end_point_number_t)((v >> 13) & 1) != ep)
                return cy_false;

        return cy_true;
}

cy_as_return_status_t
cy_as_ll_remove_ep_data_requests(cy_as_device *dev_p,
        cy_as_end_point_number_t ep)
{
        cy_as_context *ctxt_p;
        cy_as_ll_request_list_node *node_p;
        uint32_t imask;

        /*
        * first, remove any queued requests
        */
        ctxt_p = dev_p->context[CY_RQT_USB_RQT_CONTEXT];
        if (ctxt_p) {
                for (node_p = ctxt_p->request_queue_p; node_p;
                        node_p = node_p->next) {
                        if (cy_as_ll_is_e_p_transfer_related_request
                        (node_p->rqt, ep)) {
                                cy_as_ll_remove_request(dev_p, ctxt_p,
                                        node_p->rqt, cy_false);
                                break;
                        }
                }

                /*
                * now, deal with any request that may be in transit
                */
                imask = cy_as_hal_disable_interrupts();

                if (ctxt_p->request_queue_p != 0 &&
                        cy_as_ll_is_e_p_transfer_related_request
                        (ctxt_p->request_queue_p->rqt, ep) &&
                        cy_as_request_get_node_state(ctxt_p->request_queue_p) ==
                        CY_AS_REQUEST_LIST_STATE_WAITING) {
                        cy_as_hal_print_message("need to remove an in-transit "
                                "request to antioch\n");

                        /*
                        * if the request has not been fully sent to west bridge
                        * yet, abort sending. otherwise, terminate the request
                        * with a CANCELED status. firmware will already have
                        * terminated this transfer.
                        */
                        if (dev_p->ll_sending_rqt)
                                dev_p->ll_abort_curr_rqt = cy_true;
                        else {
                                uint32_t state;

                                node_p = ctxt_p->request_queue_p;
                                if (node_p->callback)
                                        node_p->callback(dev_p, ctxt_p->number,
                                                node_p->rqt, node_p->resp,
                                                CY_AS_ERROR_CANCELED);

                                ctxt_p->request_queue_p = node_p->next;
                                state = cy_as_hal_disable_interrupts();
                                cy_as_hal_c_b_free(node_p);
                                cy_as_hal_enable_interrupts(state);
                        }
                }

                cy_as_hal_enable_interrupts(imask);
        }

        return CY_AS_ERROR_SUCCESS;
}