Linux-libre 5.4.47-gnu

[librecmc/linux-libre.git] / drivers / usb / cdns3 / gadget.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Cadence USBSS DRD Driver - gadget side.
 *
 * Copyright (C) 2018-2019 Cadence Design Systems.
 * Copyright (C) 2017-2018 NXP
 *
 * Authors: Pawel Jez <pjez@cadence.com>,
 *          Pawel Laszczak <pawell@cadence.com>
 *          Peter Chen <peter.chen@nxp.com>
 */

/*
 * Work around 1:
 * At some situations, the controller may get stale data address in TRB
 * at below sequences:
 * 1. Controller read TRB includes data address
 * 2. Software updates TRBs includes data address and Cycle bit
 * 3. Controller read TRB which includes Cycle bit
 * 4. DMA run with stale data address
 *
 * To fix this problem, driver needs to make the first TRB in TD as invalid.
 * After preparing all TRBs driver needs to check the position of DMA and
 * if the DMA point to the first just added TRB and doorbell is 1,
 * then driver must defer making this TRB as valid. This TRB will be make
 * as valid during adding next TRB only if DMA is stopped or at TRBERR
 * interrupt.
 *
 * Issue has been fixed in DEV_VER_V3 version of controller.
 *
 * Work around 2:
 * Controller for OUT endpoints has shared on-chip buffers for all incoming
 * packets, including ep0out. It's FIFO buffer, so packets must be handle by DMA
 * in correct order. If the first packet in the buffer will not be handled,
 * then the following packets directed for other endpoints and  functions
 * will be blocked.
 * Additionally the packets directed to one endpoint can block entire on-chip
 * buffers. In this case transfer to other endpoints also will blocked.
 *
 * To resolve this issue after raising the descriptor missing interrupt
 * driver prepares internal usb_request object and use it to arm DMA transfer.
 *
 * The problematic situation was observed in case when endpoint has been enabled
 * but no usb_request were queued. Driver try detects such endpoints and will
 * use this workaround only for these endpoint.
 *
 * Driver use limited number of buffer. This number can be set by macro
 * CDNS3_WA2_NUM_BUFFERS.
 *
 * Such blocking situation was observed on ACM gadget. For this function
 * host send OUT data packet but ACM function is not prepared for this packet.
 * It's cause that buffer placed in on chip memory block transfer to other
 * endpoints.
 *
 * Issue has been fixed in DEV_VER_V2 version of controller.
 *
 */

#include <linux/dma-mapping.h>
#include <linux/usb/gadget.h>
#include <linux/module.h>
#include <linux/iopoll.h>

#include "core.h"
#include "gadget-export.h"
#include "gadget.h"
#include "trace.h"
#include "drd.h"

static int __cdns3_gadget_ep_queue(struct usb_ep *ep,
                                   struct usb_request *request,
                                   gfp_t gfp_flags);

/**
 * cdns3_set_register_bit - set bit in given register.
 * @ptr: address of device controller register to be read and changed
 * @mask: bits requested to set
 */
void cdns3_set_register_bit(void __iomem *ptr, u32 mask)
{
        mask = readl(ptr) | mask;
        writel(mask, ptr);
}

/**
 * cdns3_ep_addr_to_index - Macro converts endpoint address to
 * index of endpoint object in cdns3_device.eps[] container
 * @ep_addr: endpoint address for which endpoint object is required
 *
 */
u8 cdns3_ep_addr_to_index(u8 ep_addr)
{
        return (((ep_addr & 0x7F)) + ((ep_addr & USB_DIR_IN) ? 16 : 0));
}

static int cdns3_get_dma_pos(struct cdns3_device *priv_dev,
                             struct cdns3_endpoint *priv_ep)
{
        int dma_index;

        dma_index = readl(&priv_dev->regs->ep_traddr) - priv_ep->trb_pool_dma;

        return dma_index / TRB_SIZE;
}

/**
 * cdns3_next_request - returns next request from list
 * @list: list containing requests
 *
 * Returns request or NULL if no requests in list
 */
struct usb_request *cdns3_next_request(struct list_head *list)
{
        return list_first_entry_or_null(list, struct usb_request, list);
}

/**
 * cdns3_next_align_buf - returns next buffer from list
 * @list: list containing buffers
 *
 * Returns buffer or NULL if no buffers in list
 */
struct cdns3_aligned_buf *cdns3_next_align_buf(struct list_head *list)
{
        return list_first_entry_or_null(list, struct cdns3_aligned_buf, list);
}

/**
 * cdns3_next_priv_request - returns next request from list
 * @list: list containing requests
 *
 * Returns request or NULL if no requests in list
 */
struct cdns3_request *cdns3_next_priv_request(struct list_head *list)
{
        return list_first_entry_or_null(list, struct cdns3_request, list);
}

/**
 * select_ep - selects endpoint
 * @priv_dev:  extended gadget object
 * @ep: endpoint address
 */
void cdns3_select_ep(struct cdns3_device *priv_dev, u32 ep)
{
        if (priv_dev->selected_ep == ep)
                return;

        priv_dev->selected_ep = ep;
        writel(ep, &priv_dev->regs->ep_sel);
}

dma_addr_t cdns3_trb_virt_to_dma(struct cdns3_endpoint *priv_ep,
                                 struct cdns3_trb *trb)
{
        u32 offset = (char *)trb - (char *)priv_ep->trb_pool;

        return priv_ep->trb_pool_dma + offset;
}

int cdns3_ring_size(struct cdns3_endpoint *priv_ep)
{
        switch (priv_ep->type) {
        case USB_ENDPOINT_XFER_ISOC:
                return TRB_ISO_RING_SIZE;
        case USB_ENDPOINT_XFER_CONTROL:
                return TRB_CTRL_RING_SIZE;
        default:
                return TRB_RING_SIZE;
        }
}

/**
 * cdns3_allocate_trb_pool - Allocates TRB's pool for selected endpoint
 * @priv_ep:  endpoint object
 *
 * Function will return 0 on success or -ENOMEM on allocation error
 */
int cdns3_allocate_trb_pool(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        int ring_size = cdns3_ring_size(priv_ep);
        struct cdns3_trb *link_trb;

        if (!priv_ep->trb_pool) {
                priv_ep->trb_pool = dma_alloc_coherent(priv_dev->sysdev,
                                                       ring_size,
                                                       &priv_ep->trb_pool_dma,
                                                       GFP_DMA32 | GFP_ATOMIC);
                if (!priv_ep->trb_pool)
                        return -ENOMEM;
        } else {
                memset(priv_ep->trb_pool, 0, ring_size);
        }

        if (!priv_ep->num)
                return 0;

        priv_ep->num_trbs = ring_size / TRB_SIZE;
        /* Initialize the last TRB as Link TRB. */
        link_trb = (priv_ep->trb_pool + (priv_ep->num_trbs - 1));
        link_trb->buffer = TRB_BUFFER(priv_ep->trb_pool_dma);
        link_trb->control = TRB_CYCLE | TRB_TYPE(TRB_LINK) | TRB_TOGGLE;

        return 0;
}

static void cdns3_free_trb_pool(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;

        if (priv_ep->trb_pool) {
                dma_free_coherent(priv_dev->sysdev,
                                  cdns3_ring_size(priv_ep),
                                  priv_ep->trb_pool, priv_ep->trb_pool_dma);
                priv_ep->trb_pool = NULL;
        }
}

/**
 * cdns3_ep_stall_flush - Stalls and flushes selected endpoint
 * @priv_ep: endpoint object
 *
 * Endpoint must be selected before call to this function
 */
static void cdns3_ep_stall_flush(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        int val;

        trace_cdns3_halt(priv_ep, 1, 1);

        writel(EP_CMD_DFLUSH | EP_CMD_ERDY | EP_CMD_SSTALL,
               &priv_dev->regs->ep_cmd);

        /* wait for DFLUSH cleared */
        readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
                                  !(val & EP_CMD_DFLUSH), 1, 1000);
        priv_ep->flags |= EP_STALLED;
        priv_ep->flags &= ~EP_STALL_PENDING;
}

/**
 * cdns3_hw_reset_eps_config - reset endpoints configuration kept by controller.
 * @priv_dev: extended gadget object
 */
void cdns3_hw_reset_eps_config(struct cdns3_device *priv_dev)
{
        writel(USB_CONF_CFGRST, &priv_dev->regs->usb_conf);

        cdns3_allow_enable_l1(priv_dev, 0);
        priv_dev->hw_configured_flag = 0;
        priv_dev->onchip_used_size = 0;
        priv_dev->out_mem_is_allocated = 0;
        priv_dev->wait_for_setup = 0;
}

/**
 * cdns3_ep_inc_trb - increment a trb index.
 * @index: Pointer to the TRB index to increment.
 * @cs: Cycle state
 * @trb_in_seg: number of TRBs in segment
 *
 * The index should never point to the link TRB. After incrementing,
 * if it is point to the link TRB, wrap around to the beginning and revert
 * cycle state bit The
 * link TRB is always at the last TRB entry.
 */
static void cdns3_ep_inc_trb(int *index, u8 *cs, int trb_in_seg)
{
        (*index)++;
        if (*index == (trb_in_seg - 1)) {
                *index = 0;
                *cs ^=  1;
        }
}

/**
 * cdns3_ep_inc_enq - increment endpoint's enqueue pointer
 * @priv_ep: The endpoint whose enqueue pointer we're incrementing
 */
static void cdns3_ep_inc_enq(struct cdns3_endpoint *priv_ep)
{
        priv_ep->free_trbs--;
        cdns3_ep_inc_trb(&priv_ep->enqueue, &priv_ep->pcs, priv_ep->num_trbs);
}

/**
 * cdns3_ep_inc_deq - increment endpoint's dequeue pointer
 * @priv_ep: The endpoint whose dequeue pointer we're incrementing
 */
static void cdns3_ep_inc_deq(struct cdns3_endpoint *priv_ep)
{
        priv_ep->free_trbs++;
        cdns3_ep_inc_trb(&priv_ep->dequeue, &priv_ep->ccs, priv_ep->num_trbs);
}

void cdns3_move_deq_to_next_trb(struct cdns3_request *priv_req)
{
        struct cdns3_endpoint *priv_ep = priv_req->priv_ep;
        int current_trb = priv_req->start_trb;

        while (current_trb != priv_req->end_trb) {
                cdns3_ep_inc_deq(priv_ep);
                current_trb = priv_ep->dequeue;
        }

        cdns3_ep_inc_deq(priv_ep);
}

/**
 * cdns3_allow_enable_l1 - enable/disable permits to transition to L1.
 * @priv_dev: Extended gadget object
 * @enable: Enable/disable permit to transition to L1.
 *
 * If bit USB_CONF_L1EN is set and device receive Extended Token packet,
 * then controller answer with ACK handshake.
 * If bit USB_CONF_L1DS is set and device receive Extended Token packet,
 * then controller answer with NYET handshake.
 */
void cdns3_allow_enable_l1(struct cdns3_device *priv_dev, int enable)
{
        if (enable)
                writel(USB_CONF_L1EN, &priv_dev->regs->usb_conf);
        else
                writel(USB_CONF_L1DS, &priv_dev->regs->usb_conf);
}

enum usb_device_speed cdns3_get_speed(struct cdns3_device *priv_dev)
{
        u32 reg;

        reg = readl(&priv_dev->regs->usb_sts);

        if (DEV_SUPERSPEED(reg))
                return USB_SPEED_SUPER;
        else if (DEV_HIGHSPEED(reg))
                return USB_SPEED_HIGH;
        else if (DEV_FULLSPEED(reg))
                return USB_SPEED_FULL;
        else if (DEV_LOWSPEED(reg))
                return USB_SPEED_LOW;
        return USB_SPEED_UNKNOWN;
}

/**
 * cdns3_start_all_request - add to ring all request not started
 * @priv_dev: Extended gadget object
 * @priv_ep: The endpoint for whom request will be started.
 *
 * Returns return ENOMEM if transfer ring i not enough TRBs to start
 *         all requests.
 */
static int cdns3_start_all_request(struct cdns3_device *priv_dev,
                                   struct cdns3_endpoint *priv_ep)
{
        struct usb_request *request;
        int ret = 0;

        while (!list_empty(&priv_ep->deferred_req_list)) {
                request = cdns3_next_request(&priv_ep->deferred_req_list);

                ret = cdns3_ep_run_transfer(priv_ep, request);
                if (ret)
                        return ret;

                list_del(&request->list);
                list_add_tail(&request->list,
                              &priv_ep->pending_req_list);
        }

        priv_ep->flags &= ~EP_RING_FULL;
        return ret;
}

/*
 * WA2: Set flag for all not ISOC OUT endpoints. If this flag is set
 * driver try to detect whether endpoint need additional internal
 * buffer for unblocking on-chip FIFO buffer. This flag will be cleared
 * if before first DESCMISS interrupt the DMA will be armed.
 */
#define cdns3_wa2_enable_detection(priv_dev, ep_priv, reg) do { \
        if (!priv_ep->dir && priv_ep->type != USB_ENDPOINT_XFER_ISOC) { \
                priv_ep->flags |= EP_QUIRK_EXTRA_BUF_DET; \
                (reg) |= EP_STS_EN_DESCMISEN; \
        } } while (0)

/**
 * cdns3_wa2_descmiss_copy_data copy data from internal requests to
 * request queued by class driver.
 * @priv_ep: extended endpoint object
 * @request: request object
 */
static void cdns3_wa2_descmiss_copy_data(struct cdns3_endpoint *priv_ep,
                                         struct usb_request *request)
{
        struct usb_request *descmiss_req;
        struct cdns3_request *descmiss_priv_req;

        while (!list_empty(&priv_ep->wa2_descmiss_req_list)) {
                int chunk_end;
                int length;

                descmiss_priv_req =
                        cdns3_next_priv_request(&priv_ep->wa2_descmiss_req_list);
                descmiss_req = &descmiss_priv_req->request;

                /* driver can't touch pending request */
                if (descmiss_priv_req->flags & REQUEST_PENDING)
                        break;

                chunk_end = descmiss_priv_req->flags & REQUEST_INTERNAL_CH;
                length = request->actual + descmiss_req->actual;

                request->status = descmiss_req->status;

                if (length <= request->length) {
                        memcpy(&((u8 *)request->buf)[request->actual],
                               descmiss_req->buf,
                               descmiss_req->actual);
                        request->actual = length;
                } else {
                        /* It should never occures */
                        request->status = -ENOMEM;
                }

                list_del_init(&descmiss_priv_req->list);

                kfree(descmiss_req->buf);
                cdns3_gadget_ep_free_request(&priv_ep->endpoint, descmiss_req);
                --priv_ep->wa2_counter;

                if (!chunk_end)
                        break;
        }
}

struct usb_request *cdns3_wa2_gadget_giveback(struct cdns3_device *priv_dev,
                                              struct cdns3_endpoint *priv_ep,
                                              struct cdns3_request *priv_req)
{
        if (priv_ep->flags & EP_QUIRK_EXTRA_BUF_EN &&
            priv_req->flags & REQUEST_INTERNAL) {
                struct usb_request *req;

                req = cdns3_next_request(&priv_ep->deferred_req_list);

                priv_ep->descmis_req = NULL;

                if (!req)
                        return NULL;

                cdns3_wa2_descmiss_copy_data(priv_ep, req);
                if (!(priv_ep->flags & EP_QUIRK_END_TRANSFER) &&
                    req->length != req->actual) {
                        /* wait for next part of transfer */
                        return NULL;
                }

                if (req->status == -EINPROGRESS)
                        req->status = 0;

                list_del_init(&req->list);
                cdns3_start_all_request(priv_dev, priv_ep);
                return req;
        }

        return &priv_req->request;
}

int cdns3_wa2_gadget_ep_queue(struct cdns3_device *priv_dev,
                              struct cdns3_endpoint *priv_ep,
                              struct cdns3_request *priv_req)
{
        int deferred = 0;

        /*
         * If transfer was queued before DESCMISS appear than we
         * can disable handling of DESCMISS interrupt. Driver assumes that it
         * can disable special treatment for this endpoint.
         */
        if (priv_ep->flags & EP_QUIRK_EXTRA_BUF_DET) {
                u32 reg;

                cdns3_select_ep(priv_dev, priv_ep->num | priv_ep->dir);
                priv_ep->flags &= ~EP_QUIRK_EXTRA_BUF_DET;
                reg = readl(&priv_dev->regs->ep_sts_en);
                reg &= ~EP_STS_EN_DESCMISEN;
                trace_cdns3_wa2(priv_ep, "workaround disabled\n");
                writel(reg, &priv_dev->regs->ep_sts_en);
        }

        if (priv_ep->flags & EP_QUIRK_EXTRA_BUF_EN) {
                u8 pending_empty = list_empty(&priv_ep->pending_req_list);
                u8 descmiss_empty = list_empty(&priv_ep->wa2_descmiss_req_list);

                /*
                 *  DESCMISS transfer has been finished, so data will be
                 *  directly copied from internal allocated usb_request
                 *  objects.
                 */
                if (pending_empty && !descmiss_empty &&
                    !(priv_req->flags & REQUEST_INTERNAL)) {
                        cdns3_wa2_descmiss_copy_data(priv_ep,
                                                     &priv_req->request);

                        trace_cdns3_wa2(priv_ep, "get internal stored data");

                        list_add_tail(&priv_req->request.list,
                                      &priv_ep->pending_req_list);
                        cdns3_gadget_giveback(priv_ep, priv_req,
                                              priv_req->request.status);

                        /*
                         * Intentionally driver returns positive value as
                         * correct value. It informs that transfer has
                         * been finished.
                         */
                        return EINPROGRESS;
                }

                /*
                 * Driver will wait for completion DESCMISS transfer,
                 * before starts new, not DESCMISS transfer.
                 */
                if (!pending_empty && !descmiss_empty) {
                        trace_cdns3_wa2(priv_ep, "wait for pending transfer\n");
                        deferred = 1;
                }

                if (priv_req->flags & REQUEST_INTERNAL)
                        list_add_tail(&priv_req->list,
                                      &priv_ep->wa2_descmiss_req_list);
        }

        return deferred;
}

static void cdns3_wa2_remove_old_request(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_request *priv_req;

        while (!list_empty(&priv_ep->wa2_descmiss_req_list)) {
                u8 chain;

                priv_req = cdns3_next_priv_request(&priv_ep->wa2_descmiss_req_list);
                chain = !!(priv_req->flags & REQUEST_INTERNAL_CH);

                trace_cdns3_wa2(priv_ep, "removes eldest request");

                kfree(priv_req->request.buf);
                cdns3_gadget_ep_free_request(&priv_ep->endpoint,
                                             &priv_req->request);
                list_del_init(&priv_req->list);
                --priv_ep->wa2_counter;

                if (!chain)
                        break;
        }
}

/**
 * cdns3_wa2_descmissing_packet - handles descriptor missing event.
 * @priv_dev: extended gadget object
 *
 * This function is used only for WA2. For more information see Work around 2
 * description.
 */
static void cdns3_wa2_descmissing_packet(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_request *priv_req;
        struct usb_request *request;

        if (priv_ep->flags & EP_QUIRK_EXTRA_BUF_DET) {
                priv_ep->flags &= ~EP_QUIRK_EXTRA_BUF_DET;
                priv_ep->flags |= EP_QUIRK_EXTRA_BUF_EN;
        }

        trace_cdns3_wa2(priv_ep, "Description Missing detected\n");

        if (priv_ep->wa2_counter >= CDNS3_WA2_NUM_BUFFERS)
                cdns3_wa2_remove_old_request(priv_ep);

        request = cdns3_gadget_ep_alloc_request(&priv_ep->endpoint,
                                                GFP_ATOMIC);
        if (!request)
                goto err;

        priv_req = to_cdns3_request(request);
        priv_req->flags |= REQUEST_INTERNAL;

        /* if this field is still assigned it indicate that transfer related
         * with this request has not been finished yet. Driver in this
         * case simply allocate next request and assign flag REQUEST_INTERNAL_CH
         * flag to previous one. It will indicate that current request is
         * part of the previous one.
         */
        if (priv_ep->descmis_req)
                priv_ep->descmis_req->flags |= REQUEST_INTERNAL_CH;

        priv_req->request.buf = kzalloc(CDNS3_DESCMIS_BUF_SIZE,
                                        GFP_ATOMIC);
        priv_ep->wa2_counter++;

        if (!priv_req->request.buf) {
                cdns3_gadget_ep_free_request(&priv_ep->endpoint, request);
                goto err;
        }

        priv_req->request.length = CDNS3_DESCMIS_BUF_SIZE;
        priv_ep->descmis_req = priv_req;

        __cdns3_gadget_ep_queue(&priv_ep->endpoint,
                                &priv_ep->descmis_req->request,
                                GFP_ATOMIC);

        return;

err:
        dev_err(priv_ep->cdns3_dev->dev,
                "Failed: No sufficient memory for DESCMIS\n");
}

/**
 * cdns3_gadget_giveback - call struct usb_request's ->complete callback
 * @priv_ep: The endpoint to whom the request belongs to
 * @priv_req: The request we're giving back
 * @status: completion code for the request
 *
 * Must be called with controller's lock held and interrupts disabled. This
 * function will unmap @req and call its ->complete() callback to notify upper
 * layers that it has completed.
 */
void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
                           struct cdns3_request *priv_req,
                           int status)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct usb_request *request = &priv_req->request;

        list_del_init(&request->list);

        if (request->status == -EINPROGRESS)
                request->status = status;

        usb_gadget_unmap_request_by_dev(priv_dev->sysdev, request,
                                        priv_ep->dir);

        if ((priv_req->flags & REQUEST_UNALIGNED) &&
            priv_ep->dir == USB_DIR_OUT && !request->status)
                memcpy(request->buf, priv_req->aligned_buf->buf,
                       request->length);

        priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED);
        trace_cdns3_gadget_giveback(priv_req);

        if (priv_dev->dev_ver < DEV_VER_V2) {
                request = cdns3_wa2_gadget_giveback(priv_dev, priv_ep,
                                                    priv_req);
                if (!request)
                        return;
        }

        if (request->complete) {
                spin_unlock(&priv_dev->lock);
                usb_gadget_giveback_request(&priv_ep->endpoint,
                                            request);
                spin_lock(&priv_dev->lock);
        }

        if (request->buf == priv_dev->zlp_buf)
                cdns3_gadget_ep_free_request(&priv_ep->endpoint, request);
}

void cdns3_wa1_restore_cycle_bit(struct cdns3_endpoint *priv_ep)
{
        /* Work around for stale data address in TRB*/
        if (priv_ep->wa1_set) {
                trace_cdns3_wa1(priv_ep, "restore cycle bit");

                priv_ep->wa1_set = 0;
                priv_ep->wa1_trb_index = 0xFFFF;
                if (priv_ep->wa1_cycle_bit) {
                        priv_ep->wa1_trb->control =
                                priv_ep->wa1_trb->control | 0x1;
                } else {
                        priv_ep->wa1_trb->control =
                                priv_ep->wa1_trb->control & ~0x1;
                }
        }
}

static void cdns3_free_aligned_request_buf(struct work_struct *work)
{
        struct cdns3_device *priv_dev = container_of(work, struct cdns3_device,
                                        aligned_buf_wq);
        struct cdns3_aligned_buf *buf, *tmp;
        unsigned long flags;

        spin_lock_irqsave(&priv_dev->lock, flags);

        list_for_each_entry_safe(buf, tmp, &priv_dev->aligned_buf_list, list) {
                if (!buf->in_use) {
                        list_del(&buf->list);

                        /*
                         * Re-enable interrupts to free DMA capable memory.
                         * Driver can't free this memory with disabled
                         * interrupts.
                         */
                        spin_unlock_irqrestore(&priv_dev->lock, flags);
                        dma_free_coherent(priv_dev->sysdev, buf->size,
                                          buf->buf, buf->dma);
                        kfree(buf);
                        spin_lock_irqsave(&priv_dev->lock, flags);
                }
        }

        spin_unlock_irqrestore(&priv_dev->lock, flags);
}

static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req)
{
        struct cdns3_endpoint *priv_ep = priv_req->priv_ep;
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct cdns3_aligned_buf *buf;

        /* check if buffer is aligned to 8. */
        if (!((uintptr_t)priv_req->request.buf & 0x7))
                return 0;

        buf = priv_req->aligned_buf;

        if (!buf || priv_req->request.length > buf->size) {
                buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
                if (!buf)
                        return -ENOMEM;

                buf->size = priv_req->request.length;

                buf->buf = dma_alloc_coherent(priv_dev->sysdev,
                                              buf->size,
                                              &buf->dma,
                                              GFP_ATOMIC);
                if (!buf->buf) {
                        kfree(buf);
                        return -ENOMEM;
                }

                if (priv_req->aligned_buf) {
                        trace_cdns3_free_aligned_request(priv_req);
                        priv_req->aligned_buf->in_use = 0;
                        queue_work(system_freezable_wq,
                                   &priv_dev->aligned_buf_wq);
                }

                buf->in_use = 1;
                priv_req->aligned_buf = buf;

                list_add_tail(&buf->list,
                              &priv_dev->aligned_buf_list);
        }

        if (priv_ep->dir == USB_DIR_IN) {
                memcpy(buf->buf, priv_req->request.buf,
                       priv_req->request.length);
        }

        priv_req->flags |= REQUEST_UNALIGNED;
        trace_cdns3_prepare_aligned_request(priv_req);

        return 0;
}

static int cdns3_wa1_update_guard(struct cdns3_endpoint *priv_ep,
                                  struct cdns3_trb *trb)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;

        if (!priv_ep->wa1_set) {
                u32 doorbell;

                doorbell = !!(readl(&priv_dev->regs->ep_cmd) & EP_CMD_DRDY);

                if (doorbell) {
                        priv_ep->wa1_cycle_bit = priv_ep->pcs ? TRB_CYCLE : 0;
                        priv_ep->wa1_set = 1;
                        priv_ep->wa1_trb = trb;
                        priv_ep->wa1_trb_index = priv_ep->enqueue;
                        trace_cdns3_wa1(priv_ep, "set guard");
                        return 0;
                }
        }
        return 1;
}

static void cdns3_wa1_tray_restore_cycle_bit(struct cdns3_device *priv_dev,
                                             struct cdns3_endpoint *priv_ep)
{
        int dma_index;
        u32 doorbell;

        doorbell = !!(readl(&priv_dev->regs->ep_cmd) & EP_CMD_DRDY);
        dma_index = cdns3_get_dma_pos(priv_dev, priv_ep);

        if (!doorbell || dma_index != priv_ep->wa1_trb_index)
                cdns3_wa1_restore_cycle_bit(priv_ep);
}

/**
 * cdns3_ep_run_transfer - start transfer on no-default endpoint hardware
 * @priv_ep: endpoint object
 *
 * Returns zero on success or negative value on failure
 */
int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep,
                          struct usb_request *request)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct cdns3_request *priv_req;
        struct cdns3_trb *trb;
        dma_addr_t trb_dma;
        u32 togle_pcs = 1;
        int sg_iter = 0;
        int num_trb;
        int address;
        u32 control;
        int pcs;

        if (priv_ep->type == USB_ENDPOINT_XFER_ISOC)
                num_trb = priv_ep->interval;
        else
                num_trb = request->num_sgs ? request->num_sgs : 1;

        if (num_trb > priv_ep->free_trbs) {
                priv_ep->flags |= EP_RING_FULL;
                return -ENOBUFS;
        }

        priv_req = to_cdns3_request(request);
        address = priv_ep->endpoint.desc->bEndpointAddress;

        priv_ep->flags |= EP_PENDING_REQUEST;

        /* must allocate buffer aligned to 8 */
        if (priv_req->flags & REQUEST_UNALIGNED)
                trb_dma = priv_req->aligned_buf->dma;
        else
                trb_dma = request->dma;

        trb = priv_ep->trb_pool + priv_ep->enqueue;
        priv_req->start_trb = priv_ep->enqueue;
        priv_req->trb = trb;

        cdns3_select_ep(priv_ep->cdns3_dev, address);

        /* prepare ring */
        if ((priv_ep->enqueue + num_trb)  >= (priv_ep->num_trbs - 1)) {
                struct cdns3_trb *link_trb;
                int doorbell, dma_index;
                u32 ch_bit = 0;

                doorbell = !!(readl(&priv_dev->regs->ep_cmd) & EP_CMD_DRDY);
                dma_index = cdns3_get_dma_pos(priv_dev, priv_ep);

                /* Driver can't update LINK TRB if it is current processed. */
                if (doorbell && dma_index == priv_ep->num_trbs - 1) {
                        priv_ep->flags |= EP_DEFERRED_DRDY;
                        return -ENOBUFS;
                }

                /*updating C bt in  Link TRB before starting DMA*/
                link_trb = priv_ep->trb_pool + (priv_ep->num_trbs - 1);
                /*
                 * For TRs size equal 2 enabling TRB_CHAIN for epXin causes
                 * that DMA stuck at the LINK TRB.
                 * On the other hand, removing TRB_CHAIN for longer TRs for
                 * epXout cause that DMA stuck after handling LINK TRB.
                 * To eliminate this strange behavioral driver set TRB_CHAIN
                 * bit only for TR size > 2.
                 */
                if (priv_ep->type == USB_ENDPOINT_XFER_ISOC ||
                    TRBS_PER_SEGMENT > 2)
                        ch_bit = TRB_CHAIN;

                link_trb->control = ((priv_ep->pcs) ? TRB_CYCLE : 0) |
                                    TRB_TYPE(TRB_LINK) | TRB_TOGGLE | ch_bit;
        }

        if (priv_dev->dev_ver <= DEV_VER_V2)
                togle_pcs = cdns3_wa1_update_guard(priv_ep, trb);

        /* set incorrect Cycle Bit for first trb*/
        control = priv_ep->pcs ? 0 : TRB_CYCLE;

        do {
                u32 length;
                u16 td_size = 0;

                /* fill TRB */
                control |= TRB_TYPE(TRB_NORMAL);
                trb->buffer = TRB_BUFFER(request->num_sgs == 0
                                ? trb_dma : request->sg[sg_iter].dma_address);

                if (likely(!request->num_sgs))
                        length = request->length;
                else
                        length = request->sg[sg_iter].length;

                if (likely(priv_dev->dev_ver >= DEV_VER_V2))
                        td_size = DIV_ROUND_UP(length,
                                               priv_ep->endpoint.maxpacket);

                trb->length = TRB_BURST_LEN(priv_ep->trb_burst_size) |
                                        TRB_LEN(length);
                if (priv_dev->gadget.speed == USB_SPEED_SUPER)
                        trb->length |= TRB_TDL_SS_SIZE(td_size);
                else
                        control |= TRB_TDL_HS_SIZE(td_size);

                pcs = priv_ep->pcs ? TRB_CYCLE : 0;

                /*
                 * first trb should be prepared as last to avoid processing
                 *  transfer to early
                 */
                if (sg_iter != 0)
                        control |= pcs;

                if (priv_ep->type == USB_ENDPOINT_XFER_ISOC  && !priv_ep->dir) {
                        control |= TRB_IOC | TRB_ISP;
                } else {
                        /* for last element in TD or in SG list */
                        if (sg_iter == (num_trb - 1) && sg_iter != 0)
                                control |= pcs | TRB_IOC | TRB_ISP;
                }

                if (sg_iter)
                        trb->control = control;
                else
                        priv_req->trb->control = control;

                control = 0;
                ++sg_iter;
                priv_req->end_trb = priv_ep->enqueue;
                cdns3_ep_inc_enq(priv_ep);
                trb = priv_ep->trb_pool + priv_ep->enqueue;
        } while (sg_iter < num_trb);

        trb = priv_req->trb;

        priv_req->flags |= REQUEST_PENDING;

        if (sg_iter == 1)
                trb->control |= TRB_IOC | TRB_ISP;

        /*
         * Memory barrier - cycle bit must be set before other filds in trb.
         */
        wmb();

        /* give the TD to the consumer*/
        if (togle_pcs)
                trb->control =  trb->control ^ 1;

        if (priv_dev->dev_ver <= DEV_VER_V2)
                cdns3_wa1_tray_restore_cycle_bit(priv_dev, priv_ep);

        trace_cdns3_prepare_trb(priv_ep, priv_req->trb);

        /*
         * Memory barrier - Cycle Bit must be set before trb->length  and
         * trb->buffer fields.
         */
        wmb();

        /*
         * For DMULT mode we can set address to transfer ring only once after
         * enabling endpoint.
         */
        if (priv_ep->flags & EP_UPDATE_EP_TRBADDR) {
                /*
                 * Until SW is not ready to handle the OUT transfer the ISO OUT
                 * Endpoint should be disabled (EP_CFG.ENABLE = 0).
                 * EP_CFG_ENABLE must be set before updating ep_traddr.
                 */
                if (priv_ep->type == USB_ENDPOINT_XFER_ISOC  && !priv_ep->dir &&
                    !(priv_ep->flags & EP_QUIRK_ISO_OUT_EN)) {
                        priv_ep->flags |= EP_QUIRK_ISO_OUT_EN;
                        cdns3_set_register_bit(&priv_dev->regs->ep_cfg,
                                               EP_CFG_ENABLE);
                }

                writel(EP_TRADDR_TRADDR(priv_ep->trb_pool_dma +
                                        priv_req->start_trb * TRB_SIZE),
                                        &priv_dev->regs->ep_traddr);

                priv_ep->flags &= ~EP_UPDATE_EP_TRBADDR;
        }

        if (!priv_ep->wa1_set && !(priv_ep->flags & EP_STALLED)) {
                trace_cdns3_ring(priv_ep);
                /*clearing TRBERR and EP_STS_DESCMIS before seting DRDY*/
                writel(EP_STS_TRBERR | EP_STS_DESCMIS, &priv_dev->regs->ep_sts);
                writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd);
                trace_cdns3_doorbell_epx(priv_ep->name,
                                         readl(&priv_dev->regs->ep_traddr));
        }

        /* WORKAROUND for transition to L0 */
        __cdns3_gadget_wakeup(priv_dev);

        return 0;
}

void cdns3_set_hw_configuration(struct cdns3_device *priv_dev)
{
        struct cdns3_endpoint *priv_ep;
        struct usb_ep *ep;
        int val;

        if (priv_dev->hw_configured_flag)
                return;

        writel(USB_CONF_CFGSET, &priv_dev->regs->usb_conf);
        writel(EP_CMD_ERDY | EP_CMD_REQ_CMPL, &priv_dev->regs->ep_cmd);

        cdns3_set_register_bit(&priv_dev->regs->usb_conf,
                               USB_CONF_U1EN | USB_CONF_U2EN);

        /* wait until configuration set */
        readl_poll_timeout_atomic(&priv_dev->regs->usb_sts, val,
                                  val & USB_STS_CFGSTS_MASK, 1, 100);

        priv_dev->hw_configured_flag = 1;

        list_for_each_entry(ep, &priv_dev->gadget.ep_list, ep_list) {
                if (ep->enabled) {
                        priv_ep = ep_to_cdns3_ep(ep);
                        cdns3_start_all_request(priv_dev, priv_ep);
                }
        }
}

/**
 * cdns3_request_handled - check whether request has been handled by DMA
 *
 * @priv_ep: extended endpoint object.
 * @priv_req: request object for checking
 *
 * Endpoint must be selected before invoking this function.
 *
 * Returns false if request has not been handled by DMA, else returns true.
 *
 * SR - start ring
 * ER -  end ring
 * DQ = priv_ep->dequeue - dequeue position
 * EQ = priv_ep->enqueue -  enqueue position
 * ST = priv_req->start_trb - index of first TRB in transfer ring
 * ET = priv_req->end_trb - index of last TRB in transfer ring
 * CI = current_index - index of processed TRB by DMA.
 *
 * As first step, function checks if cycle bit for priv_req->start_trb is
 * correct.
 *
 * some rules:
 * 1. priv_ep->dequeue never exceed current_index.
 * 2  priv_ep->enqueue never exceed priv_ep->dequeue
 * 3. exception: priv_ep->enqueue == priv_ep->dequeue
 *    and priv_ep->free_trbs is zero.
 *    This case indicate that TR is full.
 *
 * Then We can split recognition into two parts:
 * Case 1 - priv_ep->dequeue < current_index
 *      SR ... EQ ... DQ ... CI ... ER
 *      SR ... DQ ... CI ... EQ ... ER
 *
 *      Request has been handled by DMA if ST and ET is between DQ and CI.
 *
 * Case 2 - priv_ep->dequeue > current_index
 * This situation take place when CI go through the LINK TRB at the end of
 * transfer ring.
 *      SR ... CI ... EQ ... DQ ... ER
 *
 *      Request has been handled by DMA if ET is less then CI or
 *      ET is greater or equal DQ.
 */
static bool cdns3_request_handled(struct cdns3_endpoint *priv_ep,
                                  struct cdns3_request *priv_req)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct cdns3_trb *trb = priv_req->trb;
        int current_index = 0;
        int handled = 0;
        int doorbell;

        current_index = cdns3_get_dma_pos(priv_dev, priv_ep);
        doorbell = !!(readl(&priv_dev->regs->ep_cmd) & EP_CMD_DRDY);

        trb = &priv_ep->trb_pool[priv_req->start_trb];

        if ((trb->control  & TRB_CYCLE) != priv_ep->ccs)
                goto finish;

        if (doorbell == 1 && current_index == priv_ep->dequeue)
                goto finish;

        /* The corner case for TRBS_PER_SEGMENT equal 2). */
        if (TRBS_PER_SEGMENT == 2 && priv_ep->type != USB_ENDPOINT_XFER_ISOC) {
                handled = 1;
                goto finish;
        }

        if (priv_ep->enqueue == priv_ep->dequeue &&
            priv_ep->free_trbs == 0) {
                handled = 1;
        } else if (priv_ep->dequeue < current_index) {
                if ((current_index == (priv_ep->num_trbs - 1)) &&
                    !priv_ep->dequeue)
                        goto finish;

                if (priv_req->end_trb >= priv_ep->dequeue &&
                    priv_req->end_trb < current_index)
                        handled = 1;
        } else if (priv_ep->dequeue  > current_index) {
                if (priv_req->end_trb  < current_index ||
                    priv_req->end_trb >= priv_ep->dequeue)
                        handled = 1;
        }

finish:
        trace_cdns3_request_handled(priv_req, current_index, handled);

        return handled;
}

static void cdns3_transfer_completed(struct cdns3_device *priv_dev,
                                     struct cdns3_endpoint *priv_ep)
{
        struct cdns3_request *priv_req;
        struct usb_request *request;
        struct cdns3_trb *trb;

        while (!list_empty(&priv_ep->pending_req_list)) {
                request = cdns3_next_request(&priv_ep->pending_req_list);
                priv_req = to_cdns3_request(request);

                trb = priv_ep->trb_pool + priv_ep->dequeue;

                /* Request was dequeued and TRB was changed to TRB_LINK. */
                if (TRB_FIELD_TO_TYPE(trb->control) == TRB_LINK) {
                        trace_cdns3_complete_trb(priv_ep, trb);
                        cdns3_move_deq_to_next_trb(priv_req);
                }

                /* Re-select endpoint. It could be changed by other CPU during
                 * handling usb_gadget_giveback_request.
                 */
                cdns3_select_ep(priv_dev, priv_ep->endpoint.address);

                if (!cdns3_request_handled(priv_ep, priv_req))
                        goto prepare_next_td;

                trb = priv_ep->trb_pool + priv_ep->dequeue;
                trace_cdns3_complete_trb(priv_ep, trb);

                if (trb != priv_req->trb)
                        dev_warn(priv_dev->dev,
                                 "request_trb=0x%p, queue_trb=0x%p\n",
                                 priv_req->trb, trb);

                request->actual = TRB_LEN(le32_to_cpu(trb->length));
                cdns3_move_deq_to_next_trb(priv_req);
                cdns3_gadget_giveback(priv_ep, priv_req, 0);

                if (priv_ep->type != USB_ENDPOINT_XFER_ISOC &&
                    TRBS_PER_SEGMENT == 2)
                        break;
        }
        priv_ep->flags &= ~EP_PENDING_REQUEST;

prepare_next_td:
        if (!(priv_ep->flags & EP_STALLED) &&
            !(priv_ep->flags & EP_STALL_PENDING))
                cdns3_start_all_request(priv_dev, priv_ep);
}

void cdns3_rearm_transfer(struct cdns3_endpoint *priv_ep, u8 rearm)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;

        cdns3_wa1_restore_cycle_bit(priv_ep);

        if (rearm) {
                trace_cdns3_ring(priv_ep);

                /* Cycle Bit must be updated before arming DMA. */
                wmb();
                writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd);

                __cdns3_gadget_wakeup(priv_dev);

                trace_cdns3_doorbell_epx(priv_ep->name,
                                         readl(&priv_dev->regs->ep_traddr));
        }
}

/**
 * cdns3_check_ep_interrupt_proceed - Processes interrupt related to endpoint
 * @priv_ep: endpoint object
 *
 * Returns 0
 */
static int cdns3_check_ep_interrupt_proceed(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        u32 ep_sts_reg;

        cdns3_select_ep(priv_dev, priv_ep->endpoint.address);

        trace_cdns3_epx_irq(priv_dev, priv_ep);

        ep_sts_reg = readl(&priv_dev->regs->ep_sts);
        writel(ep_sts_reg, &priv_dev->regs->ep_sts);

        if (ep_sts_reg & EP_STS_TRBERR) {
                if (priv_ep->flags & EP_STALL_PENDING &&
                    !(ep_sts_reg & EP_STS_DESCMIS &&
                    priv_dev->dev_ver < DEV_VER_V2)) {
                        cdns3_ep_stall_flush(priv_ep);
                }

                /*
                 * For isochronous transfer driver completes request on
                 * IOC or on TRBERR. IOC appears only when device receive
                 * OUT data packet. If host disable stream or lost some packet
                 * then the only way to finish all queued transfer is to do it
                 * on TRBERR event.
                 */
                if (priv_ep->type == USB_ENDPOINT_XFER_ISOC &&
                    !priv_ep->wa1_set) {
                        if (!priv_ep->dir) {
                                u32 ep_cfg = readl(&priv_dev->regs->ep_cfg);

                                ep_cfg &= ~EP_CFG_ENABLE;
                                writel(ep_cfg, &priv_dev->regs->ep_cfg);
                                priv_ep->flags &= ~EP_QUIRK_ISO_OUT_EN;
                        }
                        cdns3_transfer_completed(priv_dev, priv_ep);
                } else if (!(priv_ep->flags & EP_STALLED) &&
                          !(priv_ep->flags & EP_STALL_PENDING)) {
                        if (priv_ep->flags & EP_DEFERRED_DRDY) {
                                priv_ep->flags &= ~EP_DEFERRED_DRDY;
                                cdns3_start_all_request(priv_dev, priv_ep);
                        } else {
                                cdns3_rearm_transfer(priv_ep,
                                                     priv_ep->wa1_set);
                        }
                }
        }

        if ((ep_sts_reg & EP_STS_IOC) || (ep_sts_reg & EP_STS_ISP)) {
                if (priv_ep->flags & EP_QUIRK_EXTRA_BUF_EN) {
                        if (ep_sts_reg & EP_STS_ISP)
                                priv_ep->flags |= EP_QUIRK_END_TRANSFER;
                        else
                                priv_ep->flags &= ~EP_QUIRK_END_TRANSFER;
                }

                cdns3_transfer_completed(priv_dev, priv_ep);
        }

        /*
         * WA2: this condition should only be meet when
         * priv_ep->flags & EP_QUIRK_EXTRA_BUF_DET or
         * priv_ep->flags & EP_QUIRK_EXTRA_BUF_EN.
         * In other cases this interrupt will be disabled/
         */
        if (ep_sts_reg & EP_STS_DESCMIS && priv_dev->dev_ver < DEV_VER_V2 &&
            !(priv_ep->flags & EP_STALLED))
                cdns3_wa2_descmissing_packet(priv_ep);

        return 0;
}

static void cdns3_disconnect_gadget(struct cdns3_device *priv_dev)
{
        if (priv_dev->gadget_driver && priv_dev->gadget_driver->disconnect) {
                spin_unlock(&priv_dev->lock);
                priv_dev->gadget_driver->disconnect(&priv_dev->gadget);
                spin_lock(&priv_dev->lock);
        }
}

/**
 * cdns3_check_usb_interrupt_proceed - Processes interrupt related to device
 * @priv_dev: extended gadget object
 * @usb_ists: bitmap representation of device's reported interrupts
 * (usb_ists register value)
 */
static void cdns3_check_usb_interrupt_proceed(struct cdns3_device *priv_dev,
                                              u32 usb_ists)
{
        int speed = 0;

        trace_cdns3_usb_irq(priv_dev, usb_ists);
        if (usb_ists & USB_ISTS_L1ENTI) {
                /*
                 * WORKAROUND: CDNS3 controller has issue with hardware resuming
                 * from L1. To fix it, if any DMA transfer is pending driver
                 * must starts driving resume signal immediately.
                 */
                if (readl(&priv_dev->regs->drbl))
                        __cdns3_gadget_wakeup(priv_dev);
        }

        /* Connection detected */
        if (usb_ists & (USB_ISTS_CON2I | USB_ISTS_CONI)) {
                speed = cdns3_get_speed(priv_dev);
                priv_dev->gadget.speed = speed;
                usb_gadget_set_state(&priv_dev->gadget, USB_STATE_POWERED);
                cdns3_ep0_config(priv_dev);
        }

        /* Disconnection detected */
        if (usb_ists & (USB_ISTS_DIS2I | USB_ISTS_DISI)) {
                cdns3_disconnect_gadget(priv_dev);
                priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
                usb_gadget_set_state(&priv_dev->gadget, USB_STATE_NOTATTACHED);
                cdns3_hw_reset_eps_config(priv_dev);
        }

        if (usb_ists & (USB_ISTS_L2ENTI | USB_ISTS_U3ENTI)) {
                if (priv_dev->gadget_driver &&
                    priv_dev->gadget_driver->suspend) {
                        spin_unlock(&priv_dev->lock);
                        priv_dev->gadget_driver->suspend(&priv_dev->gadget);
                        spin_lock(&priv_dev->lock);
                }
        }

        if (usb_ists & (USB_ISTS_L2EXTI | USB_ISTS_U3EXTI)) {
                if (priv_dev->gadget_driver &&
                    priv_dev->gadget_driver->resume) {
                        spin_unlock(&priv_dev->lock);
                        priv_dev->gadget_driver->resume(&priv_dev->gadget);
                        spin_lock(&priv_dev->lock);
                }
        }

        /* reset*/
        if (usb_ists & (USB_ISTS_UWRESI | USB_ISTS_UHRESI | USB_ISTS_U2RESI)) {
                if (priv_dev->gadget_driver) {
                        spin_unlock(&priv_dev->lock);
                        usb_gadget_udc_reset(&priv_dev->gadget,
                                             priv_dev->gadget_driver);
                        spin_lock(&priv_dev->lock);

                        /*read again to check the actual speed*/
                        speed = cdns3_get_speed(priv_dev);
                        priv_dev->gadget.speed = speed;
                        cdns3_hw_reset_eps_config(priv_dev);
                        cdns3_ep0_config(priv_dev);
                }
        }
}

/**
 * cdns3_device_irq_handler- interrupt handler for device part of controller
 *
 * @irq: irq number for cdns3 core device
 * @data: structure of cdns3
 *
 * Returns IRQ_HANDLED or IRQ_NONE
 */
static irqreturn_t cdns3_device_irq_handler(int irq, void *data)
{
        struct cdns3_device *priv_dev = data;
        irqreturn_t ret = IRQ_NONE;
        u32 reg;

        /* check USB device interrupt */
        reg = readl(&priv_dev->regs->usb_ists);
        if (reg) {
                /* After masking interrupts the new interrupts won't be
                 * reported in usb_ists/ep_ists. In order to not lose some
                 * of them driver disables only detected interrupts.
                 * They will be enabled ASAP after clearing source of
                 * interrupt. This an unusual behavior only applies to
                 * usb_ists register.
                 */
                reg = ~reg & readl(&priv_dev->regs->usb_ien);
                /* mask deferred interrupt. */
                writel(reg, &priv_dev->regs->usb_ien);
                ret = IRQ_WAKE_THREAD;
        }

        /* check endpoint interrupt */
        reg = readl(&priv_dev->regs->ep_ists);
        if (reg) {
                writel(0, &priv_dev->regs->ep_ien);
                ret = IRQ_WAKE_THREAD;
        }

        return ret;
}

/**
 * cdns3_device_thread_irq_handler- interrupt handler for device part
 * of controller
 *
 * @irq: irq number for cdns3 core device
 * @data: structure of cdns3
 *
 * Returns IRQ_HANDLED or IRQ_NONE
 */
static irqreturn_t cdns3_device_thread_irq_handler(int irq, void *data)
{
        struct cdns3_device *priv_dev = data;
        irqreturn_t ret = IRQ_NONE;
        unsigned long flags;
        int bit;
        u32 reg;

        spin_lock_irqsave(&priv_dev->lock, flags);

        reg = readl(&priv_dev->regs->usb_ists);
        if (reg) {
                writel(reg, &priv_dev->regs->usb_ists);
                writel(USB_IEN_INIT, &priv_dev->regs->usb_ien);
                cdns3_check_usb_interrupt_proceed(priv_dev, reg);
                ret = IRQ_HANDLED;
        }

        reg = readl(&priv_dev->regs->ep_ists);

        /* handle default endpoint OUT */
        if (reg & EP_ISTS_EP_OUT0) {
                cdns3_check_ep0_interrupt_proceed(priv_dev, USB_DIR_OUT);
                ret = IRQ_HANDLED;
        }

        /* handle default endpoint IN */
        if (reg & EP_ISTS_EP_IN0) {
                cdns3_check_ep0_interrupt_proceed(priv_dev, USB_DIR_IN);
                ret = IRQ_HANDLED;
        }

        /* check if interrupt from non default endpoint, if no exit */
        reg &= ~(EP_ISTS_EP_OUT0 | EP_ISTS_EP_IN0);
        if (!reg)
                goto irqend;

        for_each_set_bit(bit, (unsigned long *)&reg,
                         sizeof(u32) * BITS_PER_BYTE) {
                cdns3_check_ep_interrupt_proceed(priv_dev->eps[bit]);
                ret = IRQ_HANDLED;
        }

irqend:
        writel(~0, &priv_dev->regs->ep_ien);
        spin_unlock_irqrestore(&priv_dev->lock, flags);

        return ret;
}

/**
 * cdns3_ep_onchip_buffer_reserve - Try to reserve onchip buf for EP
 *
 * The real reservation will occur during write to EP_CFG register,
 * this function is used to check if the 'size' reservation is allowed.
 *
 * @priv_dev: extended gadget object
 * @size: the size (KB) for EP would like to allocate
 * @is_in: endpoint direction
 *
 * Return 0 if the required size can met or negative value on failure
 */
static int cdns3_ep_onchip_buffer_reserve(struct cdns3_device *priv_dev,
                                          int size, int is_in)
{
        int remained;

        /* 2KB are reserved for EP0*/
        remained = priv_dev->onchip_buffers - priv_dev->onchip_used_size - 2;

        if (is_in) {
                if (remained < size)
                        return -EPERM;

                priv_dev->onchip_used_size += size;
        } else {
                int required;

                /**
                 *  ALL OUT EPs are shared the same chunk onchip memory, so
                 * driver checks if it already has assigned enough buffers
                 */
                if (priv_dev->out_mem_is_allocated >= size)
                        return 0;

                required = size - priv_dev->out_mem_is_allocated;

                if (required > remained)
                        return -EPERM;

                priv_dev->out_mem_is_allocated += required;
                priv_dev->onchip_used_size += required;
        }

        return 0;
}

void cdns3_configure_dmult(struct cdns3_device *priv_dev,
                           struct cdns3_endpoint *priv_ep)
{
        struct cdns3_usb_regs __iomem *regs = priv_dev->regs;

        /* For dev_ver > DEV_VER_V2 DMULT is configured per endpoint */
        if (priv_dev->dev_ver <= DEV_VER_V2)
                writel(USB_CONF_DMULT, &regs->usb_conf);

        if (priv_dev->dev_ver == DEV_VER_V2)
                writel(USB_CONF2_EN_TDL_TRB, &regs->usb_conf2);

        if (priv_dev->dev_ver >= DEV_VER_V3 && priv_ep) {
                u32 mask;

                if (priv_ep->dir)
                        mask = BIT(priv_ep->num + 16);
                else
                        mask = BIT(priv_ep->num);

                if (priv_ep->type != USB_ENDPOINT_XFER_ISOC) {
                        cdns3_set_register_bit(&regs->tdl_from_trb, mask);
                        cdns3_set_register_bit(&regs->tdl_beh, mask);
                        cdns3_set_register_bit(&regs->tdl_beh2, mask);
                        cdns3_set_register_bit(&regs->dma_adv_td, mask);
                }

                if (priv_ep->type == USB_ENDPOINT_XFER_ISOC && !priv_ep->dir)
                        cdns3_set_register_bit(&regs->tdl_from_trb, mask);

                cdns3_set_register_bit(&regs->dtrans, mask);
        }
}

/**
 * cdns3_ep_config Configure hardware endpoint
 * @priv_ep: extended endpoint object
 */
void cdns3_ep_config(struct cdns3_endpoint *priv_ep)
{
        bool is_iso_ep = (priv_ep->type == USB_ENDPOINT_XFER_ISOC);
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        u32 bEndpointAddress = priv_ep->num | priv_ep->dir;
        u32 max_packet_size = 0;
        u8 maxburst = 0;
        u32 ep_cfg = 0;
        u8 buffering;
        u8 mult = 0;
        int ret;

        buffering = CDNS3_EP_BUF_SIZE - 1;

        cdns3_configure_dmult(priv_dev, priv_ep);

        switch (priv_ep->type) {
        case USB_ENDPOINT_XFER_INT:
                ep_cfg = EP_CFG_EPTYPE(USB_ENDPOINT_XFER_INT);

                if ((priv_dev->dev_ver == DEV_VER_V2 && !priv_ep->dir) ||
                    priv_dev->dev_ver > DEV_VER_V2)
                        ep_cfg |= EP_CFG_TDL_CHK;
                break;
        case USB_ENDPOINT_XFER_BULK:
                ep_cfg = EP_CFG_EPTYPE(USB_ENDPOINT_XFER_BULK);

                if ((priv_dev->dev_ver == DEV_VER_V2  && !priv_ep->dir) ||
                    priv_dev->dev_ver > DEV_VER_V2)
                        ep_cfg |= EP_CFG_TDL_CHK;
                break;
        default:
                ep_cfg = EP_CFG_EPTYPE(USB_ENDPOINT_XFER_ISOC);
                mult = CDNS3_EP_ISO_HS_MULT - 1;
                buffering = mult + 1;
        }

        switch (priv_dev->gadget.speed) {
        case USB_SPEED_FULL:
                max_packet_size = is_iso_ep ? 1023 : 64;
                break;
        case USB_SPEED_HIGH:
                max_packet_size = is_iso_ep ? 1024 : 512;
                break;
        case USB_SPEED_SUPER:
                /* It's limitation that driver assumes in driver. */
                mult = 0;
                max_packet_size = 1024;
                if (priv_ep->type == USB_ENDPOINT_XFER_ISOC) {
                        maxburst = CDNS3_EP_ISO_SS_BURST - 1;
                        buffering = (mult + 1) *
                                    (maxburst + 1);

                        if (priv_ep->interval > 1)
                                buffering++;
                } else {
                        maxburst = CDNS3_EP_BUF_SIZE - 1;
                }
                break;
        default:
                /* all other speed are not supported */
                return;
        }

        if (max_packet_size == 1024)
                priv_ep->trb_burst_size = 128;
        else if (max_packet_size >= 512)
                priv_ep->trb_burst_size = 64;
        else
                priv_ep->trb_burst_size = 16;

        ret = cdns3_ep_onchip_buffer_reserve(priv_dev, buffering + 1,
                                             !!priv_ep->dir);
        if (ret) {
                dev_err(priv_dev->dev, "onchip mem is full, ep is invalid\n");
                return;
        }

        ep_cfg |= EP_CFG_MAXPKTSIZE(max_packet_size) |
                  EP_CFG_MULT(mult) |
                  EP_CFG_BUFFERING(buffering) |
                  EP_CFG_MAXBURST(maxburst);

        cdns3_select_ep(priv_dev, bEndpointAddress);
        writel(ep_cfg, &priv_dev->regs->ep_cfg);

        dev_dbg(priv_dev->dev, "Configure %s: with val %08x\n",
                priv_ep->name, ep_cfg);
}

/* Find correct direction for HW endpoint according to description */
static int cdns3_ep_dir_is_correct(struct usb_endpoint_descriptor *desc,
                                   struct cdns3_endpoint *priv_ep)
{
        return (priv_ep->endpoint.caps.dir_in && usb_endpoint_dir_in(desc)) ||
               (priv_ep->endpoint.caps.dir_out && usb_endpoint_dir_out(desc));
}

static struct
cdns3_endpoint *cdns3_find_available_ep(struct cdns3_device *priv_dev,
                                        struct usb_endpoint_descriptor *desc)
{
        struct usb_ep *ep;
        struct cdns3_endpoint *priv_ep;

        list_for_each_entry(ep, &priv_dev->gadget.ep_list, ep_list) {
                unsigned long num;
                int ret;
                /* ep name pattern likes epXin or epXout */
                char c[2] = {ep->name[2], '\0'};

                ret = kstrtoul(c, 10, &num);
                if (ret)
                        return ERR_PTR(ret);

                priv_ep = ep_to_cdns3_ep(ep);
                if (cdns3_ep_dir_is_correct(desc, priv_ep)) {
                        if (!(priv_ep->flags & EP_CLAIMED)) {
                                priv_ep->num  = num;
                                return priv_ep;
                        }
                }
        }

        return ERR_PTR(-ENOENT);
}

/*
 *  Cadence IP has one limitation that all endpoints must be configured
 * (Type & MaxPacketSize) before setting configuration through hardware
 * register, it means we can't change endpoints configuration after
 * set_configuration.
 *
 * This function set EP_CLAIMED flag which is added when the gadget driver
 * uses usb_ep_autoconfig to configure specific endpoint;
 * When the udc driver receives set_configurion request,
 * it goes through all claimed endpoints, and configure all endpoints
 * accordingly.
 *
 * At usb_ep_ops.enable/disable, we only enable and disable endpoint through
 * ep_cfg register which can be changed after set_configuration, and do
 * some software operation accordingly.
 */
static struct
usb_ep *cdns3_gadget_match_ep(struct usb_gadget *gadget,
                              struct usb_endpoint_descriptor *desc,
                              struct usb_ss_ep_comp_descriptor *comp_desc)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
        struct cdns3_endpoint *priv_ep;
        unsigned long flags;

        priv_ep = cdns3_find_available_ep(priv_dev, desc);
        if (IS_ERR(priv_ep)) {
                dev_err(priv_dev->dev, "no available ep\n");
                return NULL;
        }

        dev_dbg(priv_dev->dev, "match endpoint: %s\n", priv_ep->name);

        spin_lock_irqsave(&priv_dev->lock, flags);
        priv_ep->endpoint.desc = desc;
        priv_ep->dir  = usb_endpoint_dir_in(desc) ? USB_DIR_IN : USB_DIR_OUT;
        priv_ep->type = usb_endpoint_type(desc);
        priv_ep->flags |= EP_CLAIMED;
        priv_ep->interval = desc->bInterval ? BIT(desc->bInterval - 1) : 0;

        spin_unlock_irqrestore(&priv_dev->lock, flags);
        return &priv_ep->endpoint;
}

/**
 * cdns3_gadget_ep_alloc_request Allocates request
 * @ep: endpoint object associated with request
 * @gfp_flags: gfp flags
 *
 * Returns allocated request address, NULL on allocation error
 */
struct usb_request *cdns3_gadget_ep_alloc_request(struct usb_ep *ep,
                                                  gfp_t gfp_flags)
{
        struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
        struct cdns3_request *priv_req;

        priv_req = kzalloc(sizeof(*priv_req), gfp_flags);
        if (!priv_req)
                return NULL;

        priv_req->priv_ep = priv_ep;

        trace_cdns3_alloc_request(priv_req);
        return &priv_req->request;
}

/**
 * cdns3_gadget_ep_free_request Free memory occupied by request
 * @ep: endpoint object associated with request
 * @request: request to free memory
 */
void cdns3_gadget_ep_free_request(struct usb_ep *ep,
                                  struct usb_request *request)
{
        struct cdns3_request *priv_req = to_cdns3_request(request);

        if (priv_req->aligned_buf)
                priv_req->aligned_buf->in_use = 0;

        trace_cdns3_free_request(priv_req);
        kfree(priv_req);
}

/**
 * cdns3_gadget_ep_enable Enable endpoint
 * @ep: endpoint object
 * @desc: endpoint descriptor
 *
 * Returns 0 on success, error code elsewhere
 */
static int cdns3_gadget_ep_enable(struct usb_ep *ep,
                                  const struct usb_endpoint_descriptor *desc)
{
        struct cdns3_endpoint *priv_ep;
        struct cdns3_device *priv_dev;
        u32 reg = EP_STS_EN_TRBERREN;
        u32 bEndpointAddress;
        unsigned long flags;
        int enable = 1;
        int ret;
        int val;

        priv_ep = ep_to_cdns3_ep(ep);
        priv_dev = priv_ep->cdns3_dev;

        if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
                dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
                return -EINVAL;
        }

        if (!desc->wMaxPacketSize) {
                dev_err(priv_dev->dev, "usbss: missing wMaxPacketSize\n");
                return -EINVAL;
        }

        if (dev_WARN_ONCE(priv_dev->dev, priv_ep->flags & EP_ENABLED,
                          "%s is already enabled\n", priv_ep->name))
                return 0;

        spin_lock_irqsave(&priv_dev->lock, flags);

        priv_ep->endpoint.desc = desc;
        priv_ep->type = usb_endpoint_type(desc);
        priv_ep->interval = desc->bInterval ? BIT(desc->bInterval - 1) : 0;

        if (priv_ep->interval > ISO_MAX_INTERVAL &&
            priv_ep->type == USB_ENDPOINT_XFER_ISOC) {
                dev_err(priv_dev->dev, "Driver is limited to %d period\n",
                        ISO_MAX_INTERVAL);

                ret =  -EINVAL;
                goto exit;
        }

        ret = cdns3_allocate_trb_pool(priv_ep);

        if (ret)
                goto exit;

        bEndpointAddress = priv_ep->num | priv_ep->dir;
        cdns3_select_ep(priv_dev, bEndpointAddress);

        trace_cdns3_gadget_ep_enable(priv_ep);

        writel(EP_CMD_EPRST, &priv_dev->regs->ep_cmd);

        ret = readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
                                        !(val & (EP_CMD_CSTALL | EP_CMD_EPRST)),
                                        1, 1000);

        if (unlikely(ret)) {
                cdns3_free_trb_pool(priv_ep);
                ret =  -EINVAL;
                goto exit;
        }

        /* enable interrupt for selected endpoint */
        cdns3_set_register_bit(&priv_dev->regs->ep_ien,
                               BIT(cdns3_ep_addr_to_index(bEndpointAddress)));

        if (priv_dev->dev_ver < DEV_VER_V2)
                cdns3_wa2_enable_detection(priv_dev, priv_ep, reg);

        writel(reg, &priv_dev->regs->ep_sts_en);

        /*
         * For some versions of controller at some point during ISO OUT traffic
         * DMA reads Transfer Ring for the EP which has never got doorbell.
         * This issue was detected only on simulation, but to avoid this issue
         * driver add protection against it. To fix it driver enable ISO OUT
         * endpoint before setting DRBL. This special treatment of ISO OUT
         * endpoints are recommended by controller specification.
         */
        if (priv_ep->type == USB_ENDPOINT_XFER_ISOC  && !priv_ep->dir)
                enable = 0;

        if (enable)
                cdns3_set_register_bit(&priv_dev->regs->ep_cfg, EP_CFG_ENABLE);

        ep->desc = desc;
        priv_ep->flags &= ~(EP_PENDING_REQUEST | EP_STALLED | EP_STALL_PENDING |
                            EP_QUIRK_ISO_OUT_EN | EP_QUIRK_EXTRA_BUF_EN);
        priv_ep->flags |= EP_ENABLED | EP_UPDATE_EP_TRBADDR;
        priv_ep->wa1_set = 0;
        priv_ep->enqueue = 0;
        priv_ep->dequeue = 0;
        reg = readl(&priv_dev->regs->ep_sts);
        priv_ep->pcs = !!EP_STS_CCS(reg);
        priv_ep->ccs = !!EP_STS_CCS(reg);
        /* one TRB is reserved for link TRB used in DMULT mode*/
        priv_ep->free_trbs = priv_ep->num_trbs - 1;
exit:
        spin_unlock_irqrestore(&priv_dev->lock, flags);

        return ret;
}

/**
 * cdns3_gadget_ep_disable Disable endpoint
 * @ep: endpoint object
 *
 * Returns 0 on success, error code elsewhere
 */
static int cdns3_gadget_ep_disable(struct usb_ep *ep)
{
        struct cdns3_endpoint *priv_ep;
        struct cdns3_request *priv_req;
        struct cdns3_device *priv_dev;
        struct usb_request *request;
        unsigned long flags;
        int ret = 0;
        u32 ep_cfg;
        int val;

        if (!ep) {
                pr_err("usbss: invalid parameters\n");
                return -EINVAL;
        }

        priv_ep = ep_to_cdns3_ep(ep);
        priv_dev = priv_ep->cdns3_dev;

        if (dev_WARN_ONCE(priv_dev->dev, !(priv_ep->flags & EP_ENABLED),
                          "%s is already disabled\n", priv_ep->name))
                return 0;

        spin_lock_irqsave(&priv_dev->lock, flags);

        trace_cdns3_gadget_ep_disable(priv_ep);

        cdns3_select_ep(priv_dev, ep->desc->bEndpointAddress);

        ep_cfg = readl(&priv_dev->regs->ep_cfg);
        ep_cfg &= ~EP_CFG_ENABLE;
        writel(ep_cfg, &priv_dev->regs->ep_cfg);

        /**
         * Driver needs some time before resetting endpoint.
         * It need waits for clearing DBUSY bit or for timeout expired.
         * 10us is enough time for controller to stop transfer.
         */
        readl_poll_timeout_atomic(&priv_dev->regs->ep_sts, val,
                                  !(val & EP_STS_DBUSY), 1, 10);
        writel(EP_CMD_EPRST, &priv_dev->regs->ep_cmd);

        readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
                                  !(val & (EP_CMD_CSTALL | EP_CMD_EPRST)),
                                  1, 1000);
        if (unlikely(ret))
                dev_err(priv_dev->dev, "Timeout: %s resetting failed.\n",
                        priv_ep->name);

        while (!list_empty(&priv_ep->pending_req_list)) {
                request = cdns3_next_request(&priv_ep->pending_req_list);

                cdns3_gadget_giveback(priv_ep, to_cdns3_request(request),
                                      -ESHUTDOWN);
        }

        while (!list_empty(&priv_ep->wa2_descmiss_req_list)) {
                priv_req = cdns3_next_priv_request(&priv_ep->wa2_descmiss_req_list);

                kfree(priv_req->request.buf);
                cdns3_gadget_ep_free_request(&priv_ep->endpoint,
                                             &priv_req->request);
                list_del_init(&priv_req->list);
                --priv_ep->wa2_counter;
        }

        while (!list_empty(&priv_ep->deferred_req_list)) {
                request = cdns3_next_request(&priv_ep->deferred_req_list);

                cdns3_gadget_giveback(priv_ep, to_cdns3_request(request),
                                      -ESHUTDOWN);
        }

        priv_ep->descmis_req = NULL;

        ep->desc = NULL;
        priv_ep->flags &= ~EP_ENABLED;

        spin_unlock_irqrestore(&priv_dev->lock, flags);

        return ret;
}

/**
 * cdns3_gadget_ep_queue Transfer data on endpoint
 * @ep: endpoint object
 * @request: request object
 * @gfp_flags: gfp flags
 *
 * Returns 0 on success, error code elsewhere
 */
static int __cdns3_gadget_ep_queue(struct usb_ep *ep,
                                   struct usb_request *request,
                                   gfp_t gfp_flags)
{
        struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct cdns3_request *priv_req;
        int ret = 0;

        request->actual = 0;
        request->status = -EINPROGRESS;
        priv_req = to_cdns3_request(request);
        trace_cdns3_ep_queue(priv_req);

        if (priv_dev->dev_ver < DEV_VER_V2) {
                ret = cdns3_wa2_gadget_ep_queue(priv_dev, priv_ep,
                                                priv_req);

                if (ret == EINPROGRESS)
                        return 0;
        }

        ret = cdns3_prepare_aligned_request_buf(priv_req);
        if (ret < 0)
                return ret;

        ret = usb_gadget_map_request_by_dev(priv_dev->sysdev, request,
                                            usb_endpoint_dir_in(ep->desc));
        if (ret)
                return ret;

        list_add_tail(&request->list, &priv_ep->deferred_req_list);

        /*
         * If hardware endpoint configuration has not been set yet then
         * just queue request in deferred list. Transfer will be started in
         * cdns3_set_hw_configuration.
         */
        if (priv_dev->hw_configured_flag && !(priv_ep->flags & EP_STALLED) &&
            !(priv_ep->flags & EP_STALL_PENDING))
                cdns3_start_all_request(priv_dev, priv_ep);

        return 0;
}

static int cdns3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
                                 gfp_t gfp_flags)
{
        struct usb_request *zlp_request;
        struct cdns3_endpoint *priv_ep;
        struct cdns3_device *priv_dev;
        unsigned long flags;
        int ret;

        if (!request || !ep)
                return -EINVAL;

        priv_ep = ep_to_cdns3_ep(ep);
        priv_dev = priv_ep->cdns3_dev;

        spin_lock_irqsave(&priv_dev->lock, flags);

        ret = __cdns3_gadget_ep_queue(ep, request, gfp_flags);

        if (ret == 0 && request->zero && request->length &&
            (request->length % ep->maxpacket == 0)) {
                struct cdns3_request *priv_req;

                zlp_request = cdns3_gadget_ep_alloc_request(ep, GFP_ATOMIC);
                zlp_request->buf = priv_dev->zlp_buf;
                zlp_request->length = 0;

                priv_req = to_cdns3_request(zlp_request);
                priv_req->flags |= REQUEST_ZLP;

                dev_dbg(priv_dev->dev, "Queuing ZLP for endpoint: %s\n",
                        priv_ep->name);
                ret = __cdns3_gadget_ep_queue(ep, zlp_request, gfp_flags);
        }

        spin_unlock_irqrestore(&priv_dev->lock, flags);
        return ret;
}

/**
 * cdns3_gadget_ep_dequeue Remove request from transfer queue
 * @ep: endpoint object associated with request
 * @request: request object
 *
 * Returns 0 on success, error code elsewhere
 */
int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
                            struct usb_request *request)
{
        struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct usb_request *req, *req_temp;
        struct cdns3_request *priv_req;
        struct cdns3_trb *link_trb;
        u8 req_on_hw_ring = 0;
        unsigned long flags;
        int ret = 0;

        if (!ep || !request || !ep->desc)
                return -EINVAL;

        spin_lock_irqsave(&priv_dev->lock, flags);

        priv_req = to_cdns3_request(request);

        trace_cdns3_ep_dequeue(priv_req);

        cdns3_select_ep(priv_dev, ep->desc->bEndpointAddress);

        list_for_each_entry_safe(req, req_temp, &priv_ep->pending_req_list,
                                 list) {
                if (request == req) {
                        req_on_hw_ring = 1;
                        goto found;
                }
        }

        list_for_each_entry_safe(req, req_temp, &priv_ep->deferred_req_list,
                                 list) {
                if (request == req)
                        goto found;
        }

        goto not_found;

found:
        link_trb = priv_req->trb;

        /* Update ring only if removed request is on pending_req_list list */
        if (req_on_hw_ring && link_trb) {
                link_trb->buffer = TRB_BUFFER(priv_ep->trb_pool_dma +
                        ((priv_req->end_trb + 1) * TRB_SIZE));
                link_trb->control = (link_trb->control & TRB_CYCLE) |
                                    TRB_TYPE(TRB_LINK) | TRB_CHAIN;

                if (priv_ep->wa1_trb == priv_req->trb)
                        cdns3_wa1_restore_cycle_bit(priv_ep);
        }

        cdns3_gadget_giveback(priv_ep, priv_req, -ECONNRESET);

not_found:
        spin_unlock_irqrestore(&priv_dev->lock, flags);
        return ret;
}

/**
 * __cdns3_gadget_ep_set_halt Sets stall on selected endpoint
 * Should be called after acquiring spin_lock and selecting ep
 * @ep: endpoint object to set stall on.
 */
void __cdns3_gadget_ep_set_halt(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;

        trace_cdns3_halt(priv_ep, 1, 0);

        if (!(priv_ep->flags & EP_STALLED)) {
                u32 ep_sts_reg = readl(&priv_dev->regs->ep_sts);

                if (!(ep_sts_reg & EP_STS_DBUSY))
                        cdns3_ep_stall_flush(priv_ep);
                else
                        priv_ep->flags |= EP_STALL_PENDING;
        }
}

/**
 * __cdns3_gadget_ep_clear_halt Clears stall on selected endpoint
 * Should be called after acquiring spin_lock and selecting ep
 * @ep: endpoint object to clear stall on
 */
int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep)
{
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        struct usb_request *request;
        struct cdns3_request *priv_req;
        struct cdns3_trb *trb = NULL;
        int ret;
        int val;

        trace_cdns3_halt(priv_ep, 0, 0);

        request = cdns3_next_request(&priv_ep->pending_req_list);
        if (request) {
                priv_req = to_cdns3_request(request);
                trb = priv_req->trb;
                if (trb)
                        trb->control = trb->control ^ TRB_CYCLE;
        }

        writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);

        /* wait for EPRST cleared */
        ret = readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
                                        !(val & EP_CMD_EPRST), 1, 100);
        if (ret)
                return -EINVAL;

        priv_ep->flags &= ~(EP_STALLED | EP_STALL_PENDING);

        if (request) {
                if (trb)
                        trb->control = trb->control ^ TRB_CYCLE;
                cdns3_rearm_transfer(priv_ep, 1);
        }

        cdns3_start_all_request(priv_dev, priv_ep);
        return ret;
}

/**
 * cdns3_gadget_ep_set_halt Sets/clears stall on selected endpoint
 * @ep: endpoint object to set/clear stall on
 * @value: 1 for set stall, 0 for clear stall
 *
 * Returns 0 on success, error code elsewhere
 */
int cdns3_gadget_ep_set_halt(struct usb_ep *ep, int value)
{
        struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
        unsigned long flags;
        int ret = 0;

        if (!(priv_ep->flags & EP_ENABLED))
                return -EPERM;

        spin_lock_irqsave(&priv_dev->lock, flags);

        cdns3_select_ep(priv_dev, ep->desc->bEndpointAddress);

        if (!value) {
                priv_ep->flags &= ~EP_WEDGE;
                ret = __cdns3_gadget_ep_clear_halt(priv_ep);
        } else {
                __cdns3_gadget_ep_set_halt(priv_ep);
        }

        spin_unlock_irqrestore(&priv_dev->lock, flags);

        return ret;
}

extern const struct usb_ep_ops cdns3_gadget_ep0_ops;

static const struct usb_ep_ops cdns3_gadget_ep_ops = {
        .enable = cdns3_gadget_ep_enable,
        .disable = cdns3_gadget_ep_disable,
        .alloc_request = cdns3_gadget_ep_alloc_request,
        .free_request = cdns3_gadget_ep_free_request,
        .queue = cdns3_gadget_ep_queue,
        .dequeue = cdns3_gadget_ep_dequeue,
        .set_halt = cdns3_gadget_ep_set_halt,
        .set_wedge = cdns3_gadget_ep_set_wedge,
};

/**
 * cdns3_gadget_get_frame Returns number of actual ITP frame
 * @gadget: gadget object
 *
 * Returns number of actual ITP frame
 */
static int cdns3_gadget_get_frame(struct usb_gadget *gadget)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);

        return readl(&priv_dev->regs->usb_itpn);
}

int __cdns3_gadget_wakeup(struct cdns3_device *priv_dev)
{
        enum usb_device_speed speed;

        speed = cdns3_get_speed(priv_dev);

        if (speed >= USB_SPEED_SUPER)
                return 0;

        /* Start driving resume signaling to indicate remote wakeup. */
        writel(USB_CONF_LGO_L0, &priv_dev->regs->usb_conf);

        return 0;
}

static int cdns3_gadget_wakeup(struct usb_gadget *gadget)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
        unsigned long flags;
        int ret = 0;

        spin_lock_irqsave(&priv_dev->lock, flags);
        ret = __cdns3_gadget_wakeup(priv_dev);
        spin_unlock_irqrestore(&priv_dev->lock, flags);
        return ret;
}

static int cdns3_gadget_set_selfpowered(struct usb_gadget *gadget,
                                        int is_selfpowered)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
        unsigned long flags;

        spin_lock_irqsave(&priv_dev->lock, flags);
        priv_dev->is_selfpowered = !!is_selfpowered;
        spin_unlock_irqrestore(&priv_dev->lock, flags);
        return 0;
}

static int cdns3_gadget_pullup(struct usb_gadget *gadget, int is_on)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);

        if (is_on)
                writel(USB_CONF_DEVEN, &priv_dev->regs->usb_conf);
        else
                writel(USB_CONF_DEVDS, &priv_dev->regs->usb_conf);

        return 0;
}

static void cdns3_gadget_config(struct cdns3_device *priv_dev)
{
        struct cdns3_usb_regs __iomem *regs = priv_dev->regs;
        u32 reg;

        cdns3_ep0_config(priv_dev);

        /* enable interrupts for endpoint 0 (in and out) */
        writel(EP_IEN_EP_OUT0 | EP_IEN_EP_IN0, &regs->ep_ien);

        /*
         * Driver needs to modify LFPS minimal U1 Exit time for DEV_VER_TI_V1
         * revision of controller.
         */
        if (priv_dev->dev_ver == DEV_VER_TI_V1) {
                reg = readl(&regs->dbg_link1);

                reg &= ~DBG_LINK1_LFPS_MIN_GEN_U1_EXIT_MASK;
                reg |= DBG_LINK1_LFPS_MIN_GEN_U1_EXIT(0x55) |
                       DBG_LINK1_LFPS_MIN_GEN_U1_EXIT_SET;
                writel(reg, &regs->dbg_link1);
        }

        /*
         * By default some platforms has set protected access to memory.
         * This cause problem with cache, so driver restore non-secure
         * access to memory.
         */
        reg = readl(&regs->dma_axi_ctrl);
        reg |= DMA_AXI_CTRL_MARPROT(DMA_AXI_CTRL_NON_SECURE) |
               DMA_AXI_CTRL_MAWPROT(DMA_AXI_CTRL_NON_SECURE);
        writel(reg, &regs->dma_axi_ctrl);

        /* enable generic interrupt*/
        writel(USB_IEN_INIT, &regs->usb_ien);
        writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, &regs->usb_conf);

        cdns3_configure_dmult(priv_dev, NULL);
}

/**
 * cdns3_gadget_udc_start Gadget start
 * @gadget: gadget object
 * @driver: driver which operates on this gadget
 *
 * Returns 0 on success, error code elsewhere
 */
static int cdns3_gadget_udc_start(struct usb_gadget *gadget,
                                  struct usb_gadget_driver *driver)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
        unsigned long flags;
        enum usb_device_speed max_speed = driver->max_speed;

        spin_lock_irqsave(&priv_dev->lock, flags);
        priv_dev->gadget_driver = driver;

        /* limit speed if necessary */
        max_speed = min(driver->max_speed, gadget->max_speed);

        switch (max_speed) {
        case USB_SPEED_FULL:
                writel(USB_CONF_SFORCE_FS, &priv_dev->regs->usb_conf);
                writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
                break;
        case USB_SPEED_HIGH:
                writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
                break;
        case USB_SPEED_SUPER:
                break;
        default:
                dev_err(priv_dev->dev,
                        "invalid maximum_speed parameter %d\n",
                        max_speed);
                /* fall through */
        case USB_SPEED_UNKNOWN:
                /* default to superspeed */
                max_speed = USB_SPEED_SUPER;
                break;
        }

        cdns3_gadget_config(priv_dev);
        spin_unlock_irqrestore(&priv_dev->lock, flags);
        return 0;
}

/**
 * cdns3_gadget_udc_stop Stops gadget
 * @gadget: gadget object
 *
 * Returns 0
 */
static int cdns3_gadget_udc_stop(struct usb_gadget *gadget)
{
        struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
        struct cdns3_endpoint *priv_ep;
        u32 bEndpointAddress;
        struct usb_ep *ep;
        int ret = 0;
        int val;

        priv_dev->gadget_driver = NULL;

        priv_dev->onchip_used_size = 0;
        priv_dev->out_mem_is_allocated = 0;
        priv_dev->gadget.speed = USB_SPEED_UNKNOWN;

        list_for_each_entry(ep, &priv_dev->gadget.ep_list, ep_list) {
                priv_ep = ep_to_cdns3_ep(ep);
                bEndpointAddress = priv_ep->num | priv_ep->dir;
                cdns3_select_ep(priv_dev, bEndpointAddress);
                writel(EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
                readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
                                          !(val & EP_CMD_EPRST), 1, 100);

                priv_ep->flags &= ~EP_CLAIMED;
        }

        /* disable interrupt for device */
        writel(0, &priv_dev->regs->usb_ien);
        writel(USB_CONF_DEVDS, &priv_dev->regs->usb_conf);

        return ret;
}

static const struct usb_gadget_ops cdns3_gadget_ops = {
        .get_frame = cdns3_gadget_get_frame,
        .wakeup = cdns3_gadget_wakeup,
        .set_selfpowered = cdns3_gadget_set_selfpowered,
        .pullup = cdns3_gadget_pullup,
        .udc_start = cdns3_gadget_udc_start,
        .udc_stop = cdns3_gadget_udc_stop,
        .match_ep = cdns3_gadget_match_ep,
};

static void cdns3_free_all_eps(struct cdns3_device *priv_dev)
{
        int i;

        /* ep0 OUT point to ep0 IN. */
        priv_dev->eps[16] = NULL;

        for (i = 0; i < CDNS3_ENDPOINTS_MAX_COUNT; i++)
                if (priv_dev->eps[i]) {
                        cdns3_free_trb_pool(priv_dev->eps[i]);
                        devm_kfree(priv_dev->dev, priv_dev->eps[i]);
                }
}

/**
 * cdns3_init_eps Initializes software endpoints of gadget
 * @cdns3: extended gadget object
 *
 * Returns 0 on success, error code elsewhere
 */
static int cdns3_init_eps(struct cdns3_device *priv_dev)
{
        u32 ep_enabled_reg, iso_ep_reg;
        struct cdns3_endpoint *priv_ep;
        int ep_dir, ep_number;
        u32 ep_mask;
        int ret = 0;
        int i;

        /* Read it from USB_CAP3 to USB_CAP5 */
        ep_enabled_reg = readl(&priv_dev->regs->usb_cap3);
        iso_ep_reg = readl(&priv_dev->regs->usb_cap4);

        dev_dbg(priv_dev->dev, "Initializing non-zero endpoints\n");

        for (i = 0; i < CDNS3_ENDPOINTS_MAX_COUNT; i++) {
                ep_dir = i >> 4;        /* i div 16 */
                ep_number = i & 0xF;    /* i % 16 */
                ep_mask = BIT(i);

                if (!(ep_enabled_reg & ep_mask))
                        continue;

                if (ep_dir && !ep_number) {
                        priv_dev->eps[i] = priv_dev->eps[0];
                        continue;
                }

                priv_ep = devm_kzalloc(priv_dev->dev, sizeof(*priv_ep),
                                       GFP_KERNEL);
                if (!priv_ep)
                        goto err;

                /* set parent of endpoint object */
                priv_ep->cdns3_dev = priv_dev;
                priv_dev->eps[i] = priv_ep;
                priv_ep->num = ep_number;
                priv_ep->dir = ep_dir ? USB_DIR_IN : USB_DIR_OUT;

                if (!ep_number) {
                        ret = cdns3_init_ep0(priv_dev, priv_ep);
                        if (ret) {
                                dev_err(priv_dev->dev, "Failed to init ep0\n");
                                goto err;
                        }
                } else {
                        snprintf(priv_ep->name, sizeof(priv_ep->name), "ep%d%s",
                                 ep_number, !!ep_dir ? "in" : "out");
                        priv_ep->endpoint.name = priv_ep->name;

                        usb_ep_set_maxpacket_limit(&priv_ep->endpoint,
                                                   CDNS3_EP_MAX_PACKET_LIMIT);
                        priv_ep->endpoint.max_streams = CDNS3_EP_MAX_STREAMS;
                        priv_ep->endpoint.ops = &cdns3_gadget_ep_ops;
                        if (ep_dir)
                                priv_ep->endpoint.caps.dir_in = 1;
                        else
                                priv_ep->endpoint.caps.dir_out = 1;

                        if (iso_ep_reg & ep_mask)
                                priv_ep->endpoint.caps.type_iso = 1;

                        priv_ep->endpoint.caps.type_bulk = 1;
                        priv_ep->endpoint.caps.type_int = 1;

                        list_add_tail(&priv_ep->endpoint.ep_list,
                                      &priv_dev->gadget.ep_list);
                }

                priv_ep->flags = 0;

                dev_info(priv_dev->dev, "Initialized  %s support: %s %s\n",
                         priv_ep->name,
                         priv_ep->endpoint.caps.type_bulk ? "BULK, INT" : "",
                         priv_ep->endpoint.caps.type_iso ? "ISO" : "");

                INIT_LIST_HEAD(&priv_ep->pending_req_list);
                INIT_LIST_HEAD(&priv_ep->deferred_req_list);
                INIT_LIST_HEAD(&priv_ep->wa2_descmiss_req_list);
        }

        return 0;
err:
        cdns3_free_all_eps(priv_dev);
        return -ENOMEM;
}

void cdns3_gadget_exit(struct cdns3 *cdns)
{
        struct cdns3_device *priv_dev;

        priv_dev = cdns->gadget_dev;

        devm_free_irq(cdns->dev, cdns->dev_irq, priv_dev);

        pm_runtime_mark_last_busy(cdns->dev);
        pm_runtime_put_autosuspend(cdns->dev);

        usb_del_gadget_udc(&priv_dev->gadget);

        cdns3_free_all_eps(priv_dev);

        while (!list_empty(&priv_dev->aligned_buf_list)) {
                struct cdns3_aligned_buf *buf;

                buf = cdns3_next_align_buf(&priv_dev->aligned_buf_list);
                dma_free_coherent(priv_dev->sysdev, buf->size,
                                  buf->buf,
                                  buf->dma);

                list_del(&buf->list);
                kfree(buf);
        }

        dma_free_coherent(priv_dev->sysdev, 8, priv_dev->setup_buf,
                          priv_dev->setup_dma);

        kfree(priv_dev->zlp_buf);
        kfree(priv_dev);
        cdns->gadget_dev = NULL;
        cdns3_drd_switch_gadget(cdns, 0);
}

static int cdns3_gadget_start(struct cdns3 *cdns)
{
        struct cdns3_device *priv_dev;
        u32 max_speed;
        int ret;

        priv_dev = kzalloc(sizeof(*priv_dev), GFP_KERNEL);
        if (!priv_dev)
                return -ENOMEM;

        cdns->gadget_dev = priv_dev;
        priv_dev->sysdev = cdns->dev;
        priv_dev->dev = cdns->dev;
        priv_dev->regs = cdns->dev_regs;

        device_property_read_u16(priv_dev->dev, "cdns,on-chip-buff-size",
                                 &priv_dev->onchip_buffers);

        if (priv_dev->onchip_buffers <=  0) {
                u32 reg = readl(&priv_dev->regs->usb_cap2);

                priv_dev->onchip_buffers = USB_CAP2_ACTUAL_MEM_SIZE(reg);
        }

        if (!priv_dev->onchip_buffers)
                priv_dev->onchip_buffers = 256;

        max_speed = usb_get_maximum_speed(cdns->dev);

        /* Check the maximum_speed parameter */
        switch (max_speed) {
        case USB_SPEED_FULL:
        case USB_SPEED_HIGH:
        case USB_SPEED_SUPER:
                break;
        default:
                dev_err(cdns->dev, "invalid maximum_speed parameter %d\n",
                        max_speed);
                /* fall through */
        case USB_SPEED_UNKNOWN:
                /* default to superspeed */
                max_speed = USB_SPEED_SUPER;
                break;
        }

        /* fill gadget fields */
        priv_dev->gadget.max_speed = max_speed;
        priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
        priv_dev->gadget.ops = &cdns3_gadget_ops;
        priv_dev->gadget.name = "usb-ss-gadget";
        priv_dev->gadget.sg_supported = 1;
        priv_dev->gadget.quirk_avoids_skb_reserve = 1;

        spin_lock_init(&priv_dev->lock);
        INIT_WORK(&priv_dev->pending_status_wq,
                  cdns3_pending_setup_status_handler);

        INIT_WORK(&priv_dev->aligned_buf_wq,
                  cdns3_free_aligned_request_buf);

        /* initialize endpoint container */
        INIT_LIST_HEAD(&priv_dev->gadget.ep_list);
        INIT_LIST_HEAD(&priv_dev->aligned_buf_list);

        ret = cdns3_init_eps(priv_dev);
        if (ret) {
                dev_err(priv_dev->dev, "Failed to create endpoints\n");
                goto err1;
        }

        /* allocate memory for setup packet buffer */
        priv_dev->setup_buf = dma_alloc_coherent(priv_dev->sysdev, 8,
                                                 &priv_dev->setup_dma, GFP_DMA);
        if (!priv_dev->setup_buf) {
                ret = -ENOMEM;
                goto err2;
        }

        priv_dev->dev_ver = readl(&priv_dev->regs->usb_cap6);

        dev_dbg(priv_dev->dev, "Device Controller version: %08x\n",
                readl(&priv_dev->regs->usb_cap6));
        dev_dbg(priv_dev->dev, "USB Capabilities:: %08x\n",
                readl(&priv_dev->regs->usb_cap1));
        dev_dbg(priv_dev->dev, "On-Chip memory configuration: %08x\n",
                readl(&priv_dev->regs->usb_cap2));

        priv_dev->dev_ver = GET_DEV_BASE_VERSION(priv_dev->dev_ver);

        priv_dev->zlp_buf = kzalloc(CDNS3_EP_ZLP_BUF_SIZE, GFP_KERNEL);
        if (!priv_dev->zlp_buf) {
                ret = -ENOMEM;
                goto err3;
        }

        /* add USB gadget device */
        ret = usb_add_gadget_udc(priv_dev->dev, &priv_dev->gadget);
        if (ret < 0) {
                dev_err(priv_dev->dev,
                        "Failed to register USB device controller\n");
                goto err4;
        }

        return 0;
err4:
        kfree(priv_dev->zlp_buf);
err3:
        dma_free_coherent(priv_dev->sysdev, 8, priv_dev->setup_buf,
                          priv_dev->setup_dma);
err2:
        cdns3_free_all_eps(priv_dev);
err1:
        cdns->gadget_dev = NULL;
        return ret;
}

static int __cdns3_gadget_init(struct cdns3 *cdns)
{
        int ret = 0;

        /* Ensure 32-bit DMA Mask in case we switched back from Host mode */
        ret = dma_set_mask_and_coherent(cdns->dev, DMA_BIT_MASK(32));
        if (ret) {
                dev_err(cdns->dev, "Failed to set dma mask: %d\n", ret);
                return ret;
        }

        cdns3_drd_switch_gadget(cdns, 1);
        pm_runtime_get_sync(cdns->dev);

        ret = cdns3_gadget_start(cdns);
        if (ret)
                return ret;

        /*
         * Because interrupt line can be shared with other components in
         * driver it can't use IRQF_ONESHOT flag here.
         */
        ret = devm_request_threaded_irq(cdns->dev, cdns->dev_irq,
                                        cdns3_device_irq_handler,
                                        cdns3_device_thread_irq_handler,
                                        IRQF_SHARED, dev_name(cdns->dev),
                                        cdns->gadget_dev);

        if (ret)
                goto err0;

        return 0;
err0:
        cdns3_gadget_exit(cdns);
        return ret;
}

static int cdns3_gadget_suspend(struct cdns3 *cdns, bool do_wakeup)
{
        struct cdns3_device *priv_dev = cdns->gadget_dev;

        cdns3_disconnect_gadget(priv_dev);

        priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
        usb_gadget_set_state(&priv_dev->gadget, USB_STATE_NOTATTACHED);
        cdns3_hw_reset_eps_config(priv_dev);

        /* disable interrupt for device */
        writel(0, &priv_dev->regs->usb_ien);

        return 0;
}

static int cdns3_gadget_resume(struct cdns3 *cdns, bool hibernated)
{
        struct cdns3_device *priv_dev = cdns->gadget_dev;

        if (!priv_dev->gadget_driver)
                return 0;

        cdns3_gadget_config(priv_dev);

        return 0;
}

/**
 * cdns3_gadget_init - initialize device structure
 *
 * cdns: cdns3 instance
 *
 * This function initializes the gadget.
 */
int cdns3_gadget_init(struct cdns3 *cdns)
{
        struct cdns3_role_driver *rdrv;

        rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
        if (!rdrv)
                return -ENOMEM;

        rdrv->start     = __cdns3_gadget_init;
        rdrv->stop      = cdns3_gadget_exit;
        rdrv->suspend   = cdns3_gadget_suspend;
        rdrv->resume    = cdns3_gadget_resume;
        rdrv->state     = CDNS3_ROLE_STATE_INACTIVE;
        rdrv->name      = "gadget";
        cdns->roles[USB_ROLE_DEVICE] = rdrv;

        return 0;
}