// SPDX-License-Identifier: GPL-2.0
/*
 * Cadence CDNSP DRD Driver.
 *
 * Copyright (C) 2020 Cadence.
 *
 * Author: Pawel Laszczak <pawell@cadence.com>
 *
 */

#include <linux/moduleparam.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/iopoll.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/string_choices.h>
#include <linux/pci.h>
#include <linux/irq.h>
#include <linux/dmi.h>

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

unsigned int cdnsp_port_speed(unsigned int port_status)
{
        /*Detect gadget speed based on PORTSC register*/
        if (DEV_SUPERSPEEDPLUS(port_status) ||
            DEV_SSP_GEN1x2(port_status) || DEV_SSP_GEN2x2(port_status))
                return USB_SPEED_SUPER_PLUS;
        else if (DEV_SUPERSPEED(port_status))
                return USB_SPEED_SUPER;
        else if (DEV_HIGHSPEED(port_status))
                return USB_SPEED_HIGH;
        else if (DEV_FULLSPEED(port_status))
                return USB_SPEED_FULL;

        /* If device is detached then speed will be USB_SPEED_UNKNOWN.*/
        return USB_SPEED_UNKNOWN;
}

/*
 * Given a port state, this function returns a value that would result in the
 * port being in the same state, if the value was written to the port status
 * control register.
 * Save Read Only (RO) bits and save read/write bits where
 * writing a 0 clears the bit and writing a 1 sets the bit (RWS).
 * For all other types (RW1S, RW1CS, RW, and RZ), writing a '0' has no effect.
 */
u32 cdnsp_port_state_to_neutral(u32 state)
{
        /* Save read-only status and port state. */
        return (state & CDNSP_PORT_RO) | (state & CDNSP_PORT_RWS);
}

/**
 * cdnsp_find_next_ext_cap - Find the offset of the extended capabilities
 *                           with capability ID id.
 * @base: PCI MMIO registers base address.
 * @start: Address at which to start looking, (0 or HCC_PARAMS to start at
 *         beginning of list)
 * @id: Extended capability ID to search for.
 *
 * Returns the offset of the next matching extended capability structure.
 * Some capabilities can occur several times,
 * e.g., the EXT_CAPS_PROTOCOL, and this provides a way to find them all.
 */
int cdnsp_find_next_ext_cap(void __iomem *base, u32 start, int id)
{
        u32 offset = start;
        u32 next;
        u32 val;

        if (!start || start == HCC_PARAMS_OFFSET) {
                val = readl(base + HCC_PARAMS_OFFSET);
                if (val == ~0)
                        return 0;

                offset = HCC_EXT_CAPS(val) << 2;
                if (!offset)
                        return 0;
        }

        do {
                val = readl(base + offset);
                if (val == ~0)
                        return 0;

                if (EXT_CAPS_ID(val) == id && offset != start)
                        return offset;

                next = EXT_CAPS_NEXT(val);
                offset += next << 2;
        } while (next);

        return 0;
}

void cdnsp_set_link_state(struct cdnsp_device *pdev,
                          __le32 __iomem *port_regs,
                          u32 link_state)
{
        int port_num = 0xFF;
        u32 temp;

        temp = readl(port_regs);
        temp = cdnsp_port_state_to_neutral(temp);
        temp |= PORT_WKCONN_E | PORT_WKDISC_E;
        writel(temp, port_regs);

        temp &= ~PORT_PLS_MASK;
        temp |= PORT_LINK_STROBE | link_state;

        if (pdev->active_port)
                port_num = pdev->active_port->port_num;

        trace_cdnsp_handle_port_status(port_num, readl(port_regs));
        writel(temp, port_regs);
        trace_cdnsp_link_state_changed(port_num, readl(port_regs));
}

static void cdnsp_disable_port(struct cdnsp_device *pdev,
                               __le32 __iomem *port_regs)
{
        u32 temp = cdnsp_port_state_to_neutral(readl(port_regs));

        writel(temp | PORT_PED, port_regs);
}

static void cdnsp_clear_port_change_bit(struct cdnsp_device *pdev,
                                        __le32 __iomem *port_regs)
{
        u32 portsc = readl(port_regs);

        writel(cdnsp_port_state_to_neutral(portsc) |
               (portsc & PORT_CHANGE_BITS), port_regs);
}

static void cdnsp_set_apb_timeout_value(struct cdnsp_device *pdev)
{
        struct cdns *cdns = dev_get_drvdata(pdev->dev);
        __le32 __iomem *reg;
        void __iomem *base;
        u32 offset = 0;
        u32 val;

        if (!cdns->override_apb_timeout)
                return;

        base = &pdev->cap_regs->hc_capbase;
        offset = cdnsp_find_next_ext_cap(base, offset, D_XEC_PRE_REGS_CAP);
        reg = base + offset + REG_CHICKEN_BITS_3_OFFSET;

        val  = le32_to_cpu(readl(reg));
        val = CHICKEN_APB_TIMEOUT_SET(val, cdns->override_apb_timeout);
        writel(cpu_to_le32(val), reg);
}

static void cdnsp_set_chicken_bits_2(struct cdnsp_device *pdev, u32 bit)
{
        __le32 __iomem *reg;
        void __iomem *base;
        u32 offset = 0;

        base = &pdev->cap_regs->hc_capbase;
        offset = cdnsp_find_next_ext_cap(base, offset, D_XEC_PRE_REGS_CAP);
        reg = base + offset + REG_CHICKEN_BITS_2_OFFSET;

        bit = readl(reg) | bit;
        writel(bit, reg);
}

static void cdnsp_clear_chicken_bits_2(struct cdnsp_device *pdev, u32 bit)
{
        __le32 __iomem *reg;
        void __iomem *base;
        u32 offset = 0;

        base = &pdev->cap_regs->hc_capbase;
        offset = cdnsp_find_next_ext_cap(base, offset, D_XEC_PRE_REGS_CAP);
        reg = base + offset + REG_CHICKEN_BITS_2_OFFSET;

        bit = readl(reg) & ~bit;
        writel(bit, reg);
}

/*
 * Disable interrupts and begin the controller halting process.
 */
static void cdnsp_quiesce(struct cdnsp_device *pdev)
{
        u32 halted;
        u32 mask;
        u32 cmd;

        mask = ~(u32)(CDNSP_IRQS);

        halted = readl(&pdev->op_regs->status) & STS_HALT;
        if (!halted)
                mask &= ~(CMD_R_S | CMD_DEVEN);

        cmd = readl(&pdev->op_regs->command);
        cmd &= mask;
        writel(cmd, &pdev->op_regs->command);
}

/*
 * Force controller into halt state.
 *
 * Disable any IRQs and clear the run/stop bit.
 * Controller will complete any current and actively pipelined transactions, and
 * should halt within 16 ms of the run/stop bit being cleared.
 * Read controller Halted bit in the status register to see when the
 * controller is finished.
 */
int cdnsp_halt(struct cdnsp_device *pdev)
{
        int ret;
        u32 val;

        cdnsp_quiesce(pdev);

        ret = readl_poll_timeout_atomic(&pdev->op_regs->status, val,
                                        val & STS_HALT, 1,
                                        CDNSP_MAX_HALT_USEC);
        if (ret) {
                dev_err(pdev->dev, "ERROR: Device halt failed\n");
                return ret;
        }

        pdev->cdnsp_state |= CDNSP_STATE_HALTED;

        return 0;
}

/*
 * device controller died, register read returns 0xffffffff, or command never
 * ends.
 */
void cdnsp_died(struct cdnsp_device *pdev)
{
        dev_err(pdev->dev, "ERROR: CDNSP controller not responding\n");
        pdev->cdnsp_state |= CDNSP_STATE_DYING;
        cdnsp_halt(pdev);
}

/*
 * Set the run bit and wait for the device to be running.
 */
static int cdnsp_start(struct cdnsp_device *pdev)
{
        u32 temp;
        int ret;

        temp = readl(&pdev->op_regs->command);
        temp |= (CMD_R_S | CMD_DEVEN);
        writel(temp, &pdev->op_regs->command);

        pdev->cdnsp_state = 0;

        /*
         * Wait for the STS_HALT Status bit to be 0 to indicate the device is
         * running.
         */
        ret = readl_poll_timeout_atomic(&pdev->op_regs->status, temp,
                                        !(temp & STS_HALT), 1,
                                        CDNSP_MAX_HALT_USEC);
        if (ret) {
                pdev->cdnsp_state = CDNSP_STATE_DYING;
                dev_err(pdev->dev, "ERROR: Controller run failed\n");
        }

        return ret;
}

/*
 * Reset a halted controller.
 *
 * This resets pipelines, timers, counters, state machines, etc.
 * Transactions will be terminated immediately, and operational registers
 * will be set to their defaults.
 */
int cdnsp_reset(struct cdnsp_device *pdev)
{
        u32 command;
        u32 temp;
        int ret;

        temp = readl(&pdev->op_regs->status);

        if (temp == ~(u32)0) {
                dev_err(pdev->dev, "Device not accessible, reset failed.\n");
                return -ENODEV;
        }

        if ((temp & STS_HALT) == 0) {
                dev_err(pdev->dev, "Controller not halted, aborting reset.\n");
                return -EINVAL;
        }

        command = readl(&pdev->op_regs->command);
        command |= CMD_RESET;
        writel(command, &pdev->op_regs->command);

        ret = readl_poll_timeout_atomic(&pdev->op_regs->command, temp,
                                        !(temp & CMD_RESET), 1,
                                        10 * 1000);
        if (ret) {
                dev_err(pdev->dev, "ERROR: Controller reset failed\n");
                return ret;
        }

        /*
         * CDNSP cannot write any doorbells or operational registers other
         * than status until the "Controller Not Ready" flag is cleared.
         */
        ret = readl_poll_timeout_atomic(&pdev->op_regs->status, temp,
                                        !(temp & STS_CNR), 1,
                                        10 * 1000);

        if (ret) {
                dev_err(pdev->dev, "ERROR: Controller not ready to work\n");
                return ret;
        }

        dev_dbg(pdev->dev, "Controller ready to work");

        return ret;
}

/*
 * cdnsp_get_endpoint_index - Find the index for an endpoint given its
 * descriptor.Use the return value to right shift 1 for the bitmask.
 *
 * Index = (epnum * 2) + direction - 1,
 * where direction = 0 for OUT, 1 for IN.
 * For control endpoints, the IN index is used (OUT index is unused), so
 * index = (epnum * 2) + direction - 1 = (epnum * 2) + 1 - 1 = (epnum * 2)
 */
static unsigned int
        cdnsp_get_endpoint_index(const struct usb_endpoint_descriptor *desc)
{
        unsigned int index = (unsigned int)usb_endpoint_num(desc);

        if (usb_endpoint_xfer_control(desc))
                return index * 2;

        return (index * 2) + (usb_endpoint_dir_in(desc) ? 1 : 0) - 1;
}

/*
 * Find the flag for this endpoint (for use in the control context). Use the
 * endpoint index to create a bitmask. The slot context is bit 0, endpoint 0 is
 * bit 1, etc.
 */
static unsigned int
        cdnsp_get_endpoint_flag(const struct usb_endpoint_descriptor *desc)
{
        return 1 << (cdnsp_get_endpoint_index(desc) + 1);
}

int cdnsp_ep_enqueue(struct cdnsp_ep *pep, struct cdnsp_request *preq)
{
        struct cdnsp_device *pdev = pep->pdev;
        struct usb_request *request;
        int ret;

        if (preq->epnum == 0 && !list_empty(&pep->pending_list)) {
                trace_cdnsp_request_enqueue_busy(preq);
                return -EBUSY;
        }

        request = &preq->request;
        request->actual = 0;
        request->status = -EINPROGRESS;
        preq->direction = pep->direction;
        preq->epnum = pep->number;
        preq->td.drbl = 0;

        ret = usb_gadget_map_request_by_dev(pdev->dev, request, pep->direction);
        if (ret) {
                trace_cdnsp_request_enqueue_error(preq);
                return ret;
        }

        list_add_tail(&preq->list, &pep->pending_list);

        trace_cdnsp_request_enqueue(preq);

        switch (usb_endpoint_type(pep->endpoint.desc)) {
        case USB_ENDPOINT_XFER_CONTROL:
                ret = cdnsp_queue_ctrl_tx(pdev, preq);
                break;
        case USB_ENDPOINT_XFER_BULK:
        case USB_ENDPOINT_XFER_INT:
                ret = cdnsp_queue_bulk_tx(pdev, preq);
                break;
        case USB_ENDPOINT_XFER_ISOC:
                ret = cdnsp_queue_isoc_tx(pdev, preq);
        }

        if (ret)
                goto unmap;

        return 0;

unmap:
        usb_gadget_unmap_request_by_dev(pdev->dev, &preq->request,
                                        pep->direction);
        list_del(&preq->list);
        trace_cdnsp_request_enqueue_error(preq);

        return ret;
}

/*
 * Remove the request's TD from the endpoint ring. This may cause the
 * controller to stop USB transfers, potentially stopping in the middle of a
 * TRB buffer. The controller should pick up where it left off in the TD,
 * unless a Set Transfer Ring Dequeue Pointer is issued.
 *
 * The TRBs that make up the buffers for the canceled request will be "removed"
 * from the ring. Since the ring is a contiguous structure, they can't be
 * physically removed. Instead, there are two options:
 *
 *  1) If the controller is in the middle of processing the request to be
 *     canceled, we simply move the ring's dequeue pointer past those TRBs
 *     using the Set Transfer Ring Dequeue Pointer command. This will be
 *     the common case, when drivers timeout on the last submitted request
 *     and attempt to cancel.
 *
 *  2) If the controller is in the middle of a different TD, we turn the TRBs
 *     into a series of 1-TRB transfer no-op TDs. No-ops shouldn't be chained.
 *     The controller will need to invalidate the any TRBs it has cached after
 *     the stop endpoint command.
 *
 *  3) The TD may have completed by the time the Stop Endpoint Command
 *     completes, so software needs to handle that case too.
 *
 */
int cdnsp_ep_dequeue(struct cdnsp_ep *pep, struct cdnsp_request *preq)
{
        struct cdnsp_device *pdev = pep->pdev;
        int ret_stop = 0;
        int ret_rem;

        trace_cdnsp_request_dequeue(preq);

        if (GET_EP_CTX_STATE(pep->out_ctx) == EP_STATE_RUNNING)
                ret_stop = cdnsp_cmd_stop_ep(pdev, pep);

        ret_rem = cdnsp_remove_request(pdev, preq, pep);

        return ret_rem ? ret_rem : ret_stop;
}

static void cdnsp_zero_in_ctx(struct cdnsp_device *pdev)
{
        struct cdnsp_input_control_ctx *ctrl_ctx;
        struct cdnsp_slot_ctx *slot_ctx;
        struct cdnsp_ep_ctx *ep_ctx;
        int i;

        ctrl_ctx = cdnsp_get_input_control_ctx(&pdev->in_ctx);

        /*
         * When a device's add flag and drop flag are zero, any subsequent
         * configure endpoint command will leave that endpoint's state
         * untouched. Make sure we don't leave any old state in the input
         * endpoint contexts.
         */
        ctrl_ctx->drop_flags = 0;
        ctrl_ctx->add_flags = 0;
        slot_ctx = cdnsp_get_slot_ctx(&pdev->in_ctx);
        slot_ctx->dev_info &= cpu_to_le32(~LAST_CTX_MASK);

        /* Endpoint 0 is always valid */
        slot_ctx->dev_info |= cpu_to_le32(LAST_CTX(1));
        for (i = 1; i < CDNSP_ENDPOINTS_NUM; ++i) {
                ep_ctx = cdnsp_get_ep_ctx(&pdev->in_ctx, i);
                ep_ctx->ep_info = 0;
                ep_ctx->ep_info2 = 0;
                ep_ctx->deq = 0;
                ep_ctx->tx_info = 0;
        }
}

/* Issue a configure endpoint command and wait for it to finish. */
static int cdnsp_configure_endpoint(struct cdnsp_device *pdev)
{
        int ret;

        cdnsp_queue_configure_endpoint(pdev, pdev->cmd.in_ctx->dma);
        cdnsp_ring_cmd_db(pdev);
        ret = cdnsp_wait_for_cmd_compl(pdev);
        if (ret) {
                dev_err(pdev->dev,
                        "ERR: unexpected command completion code 0x%x.\n", ret);
                return -EINVAL;
        }

        return ret;
}

static void cdnsp_invalidate_ep_events(struct cdnsp_device *pdev,
                                       struct cdnsp_ep *pep)
{
        struct cdnsp_segment *segment;
        union cdnsp_trb *event;
        u32 cycle_state;
        u32  data;

        event = pdev->event_ring->dequeue;
        segment = pdev->event_ring->deq_seg;
        cycle_state = pdev->event_ring->cycle_state;

        while (1) {
                data = le32_to_cpu(event->trans_event.flags);

                /* Check the owner of the TRB. */
                if ((data & TRB_CYCLE) != cycle_state)
                        break;

                if (TRB_FIELD_TO_TYPE(data) == TRB_TRANSFER &&
                    TRB_TO_EP_ID(data) == (pep->idx + 1)) {
                        data |= TRB_EVENT_INVALIDATE;
                        event->trans_event.flags = cpu_to_le32(data);
                }

                if (cdnsp_last_trb_on_seg(segment, event)) {
                        cycle_state ^= 1;
                        segment = pdev->event_ring->deq_seg->next;
                        event = segment->trbs;
                } else {
                        event++;
                }
        }
}

int cdnsp_wait_for_cmd_compl(struct cdnsp_device *pdev)
{
        struct cdnsp_segment *event_deq_seg;
        union cdnsp_trb *cmd_trb;
        dma_addr_t cmd_deq_dma;
        union cdnsp_trb *event;
        u32 cycle_state;
        u32 retry = 10;
        int ret, val;
        u64 cmd_dma;
        u32  flags;

        cmd_trb = pdev->cmd.command_trb;
        pdev->cmd.status = 0;

        trace_cdnsp_cmd_wait_for_compl(pdev->cmd_ring, &cmd_trb->generic);

        ret = readl_poll_timeout_atomic(&pdev->op_regs->cmd_ring, val,
                                        !CMD_RING_BUSY(val), 1,
                                        CDNSP_CMD_TIMEOUT);
        if (ret) {
                dev_err(pdev->dev, "ERR: Timeout while waiting for command\n");
                trace_cdnsp_cmd_timeout(pdev->cmd_ring, &cmd_trb->generic);
                pdev->cdnsp_state = CDNSP_STATE_DYING;
                return -ETIMEDOUT;
        }

        event = pdev->event_ring->dequeue;
        event_deq_seg = pdev->event_ring->deq_seg;
        cycle_state = pdev->event_ring->cycle_state;

        cmd_deq_dma = cdnsp_trb_virt_to_dma(pdev->cmd_ring->deq_seg, cmd_trb);
        if (!cmd_deq_dma)
                return -EINVAL;

        while (1) {
                flags = le32_to_cpu(event->event_cmd.flags);

                /* Check the owner of the TRB. */
                if ((flags & TRB_CYCLE) != cycle_state) {
                        /*
                         * Give some extra time to get chance controller
                         * to finish command before returning error code.
                         * Checking CMD_RING_BUSY is not sufficient because
                         * this bit is cleared to '0' when the Command
                         * Descriptor has been executed by controller
                         * and not when command completion event has
                         * be added to event ring.
                         */
                        if (retry--) {
                                udelay(20);
                                continue;
                        }

                        return -EINVAL;
                }

                cmd_dma = le64_to_cpu(event->event_cmd.cmd_trb);

                /*
                 * Check whether the completion event is for last queued
                 * command.
                 */
                if (TRB_FIELD_TO_TYPE(flags) != TRB_COMPLETION ||
                    cmd_dma != (u64)cmd_deq_dma) {
                        if (!cdnsp_last_trb_on_seg(event_deq_seg, event)) {
                                event++;
                                continue;
                        }

                        if (cdnsp_last_trb_on_ring(pdev->event_ring,
                                                   event_deq_seg, event))
                                cycle_state ^= 1;

                        event_deq_seg = event_deq_seg->next;
                        event = event_deq_seg->trbs;
                        continue;
                }

                trace_cdnsp_handle_command(pdev->cmd_ring, &cmd_trb->generic);

                pdev->cmd.status = GET_COMP_CODE(le32_to_cpu(event->event_cmd.status));
                if (pdev->cmd.status == COMP_SUCCESS)
                        return 0;

                return -pdev->cmd.status;
        }
}

int cdnsp_halt_endpoint(struct cdnsp_device *pdev,
                        struct cdnsp_ep *pep,
                        int value)
{
        int ret;

        trace_cdnsp_ep_halt(value ? "Set" : "Clear");

        ret = cdnsp_cmd_stop_ep(pdev, pep);
        if (ret)
                return ret;

        if (value) {
                if (GET_EP_CTX_STATE(pep->out_ctx) == EP_STATE_STOPPED) {
                        cdnsp_queue_halt_endpoint(pdev, pep->idx);
                        cdnsp_ring_cmd_db(pdev);
                        ret = cdnsp_wait_for_cmd_compl(pdev);
                }

                pep->ep_state |= EP_HALTED;
        } else {
                cdnsp_queue_reset_ep(pdev, pep->idx);
                cdnsp_ring_cmd_db(pdev);
                ret = cdnsp_wait_for_cmd_compl(pdev);
                trace_cdnsp_handle_cmd_reset_ep(pep->out_ctx);

                if (ret)
                        return ret;

                pep->ep_state &= ~EP_HALTED;

                if (pep->idx != 0 && !(pep->ep_state & EP_WEDGE))
                        cdnsp_ring_doorbell_for_active_rings(pdev, pep);

                pep->ep_state &= ~EP_WEDGE;
        }

        return 0;
}

static int cdnsp_update_eps_configuration(struct cdnsp_device *pdev,
                                          struct cdnsp_ep *pep)
{
        struct cdnsp_input_control_ctx *ctrl_ctx;
        struct cdnsp_slot_ctx *slot_ctx;
        int ret = 0;
        u32 ep_sts;
        int i;

        ctrl_ctx = cdnsp_get_input_control_ctx(&pdev->in_ctx);

        /* Don't issue the command if there's no endpoints to update. */
        if (ctrl_ctx->add_flags == 0 && ctrl_ctx->drop_flags == 0)
                return 0;

        ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
        ctrl_ctx->add_flags &= cpu_to_le32(~EP0_FLAG);
        ctrl_ctx->drop_flags &= cpu_to_le32(~(SLOT_FLAG | EP0_FLAG));

        /* Fix up Context Entries field. Minimum value is EP0 == BIT(1). */
        slot_ctx = cdnsp_get_slot_ctx(&pdev->in_ctx);
        for (i = CDNSP_ENDPOINTS_NUM; i >= 1; i--) {
                __le32 le32 = cpu_to_le32(BIT(i));

                if ((pdev->eps[i - 1].ring && !(ctrl_ctx->drop_flags & le32)) ||
                    (ctrl_ctx->add_flags & le32) || i == 1) {
                        slot_ctx->dev_info &= cpu_to_le32(~LAST_CTX_MASK);
                        slot_ctx->dev_info |= cpu_to_le32(LAST_CTX(i));
                        break;
                }
        }

        ep_sts = GET_EP_CTX_STATE(pep->out_ctx);

        if ((ctrl_ctx->add_flags != cpu_to_le32(SLOT_FLAG) &&
             ep_sts == EP_STATE_DISABLED) ||
            (ep_sts != EP_STATE_DISABLED && ctrl_ctx->drop_flags))
                ret = cdnsp_configure_endpoint(pdev);

        trace_cdnsp_configure_endpoint(cdnsp_get_slot_ctx(&pdev->out_ctx));
        trace_cdnsp_handle_cmd_config_ep(pep->out_ctx);

        cdnsp_zero_in_ctx(pdev);

        return ret;
}

/*
 * This submits a Reset Device Command, which will set the device state to 0,
 * set the device address to 0, and disable all the endpoints except the default
 * control endpoint. The USB core should come back and call
 * cdnsp_setup_device(), and then re-set up the configuration.
 */
int cdnsp_reset_device(struct cdnsp_device *pdev)
{
        struct cdnsp_slot_ctx *slot_ctx;
        int slot_state;
        int ret, i;

        slot_ctx = cdnsp_get_slot_ctx(&pdev->in_ctx);
        slot_ctx->dev_info = 0;
        pdev->device_address = 0;

        /* If device is not setup, there is no point in resetting it. */
        slot_ctx = cdnsp_get_slot_ctx(&pdev->out_ctx);
        slot_state = GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state));
        trace_cdnsp_reset_device(slot_ctx);

        if (slot_state <= SLOT_STATE_DEFAULT &&
            pdev->eps[0].ep_state & EP_HALTED) {
                cdnsp_halt_endpoint(pdev, &pdev->eps[0], 0);
        }

        /*
         * During Reset Device command controller shall transition the
         * endpoint ep0 to the Running State.
         */
        pdev->eps[0].ep_state &= ~(EP_STOPPED | EP_HALTED);
        pdev->eps[0].ep_state |= EP_ENABLED;

        if (slot_state <= SLOT_STATE_DEFAULT)
                return 0;

        cdnsp_queue_reset_device(pdev);
        cdnsp_ring_cmd_db(pdev);
        ret = cdnsp_wait_for_cmd_compl(pdev);

        /*
         * After Reset Device command all not default endpoints
         * are in Disabled state.
         */
        for (i = 1; i < CDNSP_ENDPOINTS_NUM; ++i)
                pdev->eps[i].ep_state |= EP_STOPPED | EP_UNCONFIGURED;

        trace_cdnsp_handle_cmd_reset_dev(slot_ctx);

        if (ret)
                dev_err(pdev->dev, "Reset device failed with error code %d",
                        ret);

        return ret;
}

/*
 * Sets the MaxPStreams field and the Linear Stream Array field.
 * Sets the dequeue pointer to the stream context array.
 */
static void cdnsp_setup_streams_ep_input_ctx(struct cdnsp_device *pdev,
                                             struct cdnsp_ep_ctx *ep_ctx,
                                             struct cdnsp_stream_info *stream_info)
{
        u32 max_primary_streams;

        /* MaxPStreams is the number of stream context array entries, not the
         * number we're actually using. Must be in 2^(MaxPstreams + 1) format.
         * fls(0) = 0, fls(0x1) = 1, fls(0x10) = 2, fls(0x100) = 3, etc.
         */
        max_primary_streams = fls(stream_info->num_stream_ctxs) - 2;
        ep_ctx->ep_info &= cpu_to_le32(~EP_MAXPSTREAMS_MASK);
        ep_ctx->ep_info |= cpu_to_le32(EP_MAXPSTREAMS(max_primary_streams)
                                       | EP_HAS_LSA);
        ep_ctx->deq  = cpu_to_le64(stream_info->ctx_array_dma);
}

/*
 * The drivers use this function to prepare a bulk endpoints to use streams.
 *
 * Don't allow the call to succeed if endpoint only supports one stream
 * (which means it doesn't support streams at all).
 */
int cdnsp_alloc_streams(struct cdnsp_device *pdev, struct cdnsp_ep *pep)
{
        unsigned int num_streams = usb_ss_max_streams(pep->endpoint.comp_desc);
        unsigned int num_stream_ctxs;
        int ret;

        if (num_streams ==  0)
                return 0;

        if (num_streams > STREAM_NUM_STREAMS)
                return -EINVAL;

        /*
         * Add two to the number of streams requested to account for
         * stream 0 that is reserved for controller usage and one additional
         * for TASK SET FULL response.
         */
        num_streams += 2;

        /* The stream context array size must be a power of two */
        num_stream_ctxs = roundup_pow_of_two(num_streams);

        trace_cdnsp_stream_number(pep, num_stream_ctxs, num_streams);

        ret = cdnsp_alloc_stream_info(pdev, pep, num_stream_ctxs, num_streams);
        if (ret)
                return ret;

        cdnsp_setup_streams_ep_input_ctx(pdev, pep->in_ctx, &pep->stream_info);

        pep->ep_state |= EP_HAS_STREAMS;
        pep->stream_info.td_count = 0;
        pep->stream_info.first_prime_det = 0;

        /* Subtract 1 for stream 0, which drivers can't use. */
        return num_streams - 1;
}

int cdnsp_disable_slot(struct cdnsp_device *pdev)
{
        int ret;

        cdnsp_queue_slot_control(pdev, TRB_DISABLE_SLOT);
        cdnsp_ring_cmd_db(pdev);
        ret = cdnsp_wait_for_cmd_compl(pdev);

        pdev->slot_id = 0;
        pdev->active_port = NULL;

        trace_cdnsp_handle_cmd_disable_slot(cdnsp_get_slot_ctx(&pdev->out_ctx));

        memset(pdev->in_ctx.bytes, 0, CDNSP_CTX_SIZE);
        memset(pdev->out_ctx.bytes, 0, CDNSP_CTX_SIZE);

        return ret;
}

int cdnsp_enable_slot(struct cdnsp_device *pdev)
{
        struct cdnsp_slot_ctx *slot_ctx;
        int slot_state;
        int ret;

        /* If device is not setup, there is no point in resetting it */
        slot_ctx = cdnsp_get_slot_ctx(&pdev->out_ctx);
        slot_state = GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state));

        if (slot_state != SLOT_STATE_DISABLED)
                return 0;

        cdnsp_queue_slot_control(pdev, TRB_ENABLE_SLOT);
        cdnsp_ring_cmd_db(pdev);
        ret = cdnsp_wait_for_cmd_compl(pdev);
        if (ret)
                goto show_trace;

        pdev->slot_id = 1;

show_trace:
        trace_cdnsp_handle_cmd_enable_slot(cdnsp_get_slot_ctx(&pdev->out_ctx));

        return ret;
}

/*
 * Issue an Address Device command with BSR=0 if setup is SETUP_CONTEXT_ONLY
 * or with BSR = 1 if set_address is SETUP_CONTEXT_ADDRESS.
 */
int cdnsp_setup_device(struct cdnsp_device *pdev, enum cdnsp_setup_dev setup)
{
        struct cdnsp_input_control_ctx *ctrl_ctx;
        struct cdnsp_slot_ctx *slot_ctx;
        int dev_state = 0;
        int ret;

        if (!pdev->slot_id) {
                trace_cdnsp_slot_id("incorrect");
                return -EINVAL;
        }

        if (!pdev->active_port->port_num)
                return -EINVAL;

        slot_ctx = cdnsp_get_slot_ctx(&pdev->out_ctx);
        dev_state = GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state));

        if (setup == SETUP_CONTEXT_ONLY && dev_state == SLOT_STATE_DEFAULT) {
                trace_cdnsp_slot_already_in_default(slot_ctx);
                return 0;
        }

        slot_ctx = cdnsp_get_slot_ctx(&pdev->in_ctx);
        ctrl_ctx = cdnsp_get_input_control_ctx(&pdev->in_ctx);

        if (!slot_ctx->dev_info || dev_state == SLOT_STATE_DEFAULT) {
                ret = cdnsp_setup_addressable_priv_dev(pdev);
                if (ret)
                        return ret;
        }

        cdnsp_copy_ep0_dequeue_into_input_ctx(pdev);

        ctrl_ctx->add_flags = cpu_to_le32(SLOT_FLAG | EP0_FLAG);
        ctrl_ctx->drop_flags = 0;

        trace_cdnsp_setup_device_slot(slot_ctx);

        cdnsp_queue_address_device(pdev, pdev->in_ctx.dma, setup);
        cdnsp_ring_cmd_db(pdev);
        ret = cdnsp_wait_for_cmd_compl(pdev);

        trace_cdnsp_handle_cmd_addr_dev(cdnsp_get_slot_ctx(&pdev->out_ctx));

        /* Zero the input context control for later use. */
        ctrl_ctx->add_flags = 0;
        ctrl_ctx->drop_flags = 0;

        return ret;
}

void cdnsp_set_usb2_hardware_lpm(struct cdnsp_device *pdev,
                                 struct usb_request *req,
                                 int enable)
{
        if (pdev->active_port != &pdev->usb2_port || !pdev->gadget.lpm_capable)
                return;

        trace_cdnsp_lpm(enable);

        if (enable)
                writel(PORT_BESL(CDNSP_DEFAULT_BESL) | PORT_L1S_NYET | PORT_HLE,
                       &pdev->active_port->regs->portpmsc);
        else
                writel(PORT_L1S_NYET, &pdev->active_port->regs->portpmsc);
}

static int cdnsp_get_frame(struct cdnsp_device *pdev)
{
        return readl(&pdev->run_regs->microframe_index) >> 3;
}

static int cdnsp_gadget_ep_enable(struct usb_ep *ep,
                                  const struct usb_endpoint_descriptor *desc)
{
        struct cdnsp_input_control_ctx *ctrl_ctx;
        struct cdnsp_device *pdev;
        struct cdnsp_ep *pep;
        unsigned long flags;
        u32 added_ctxs;
        int ret;

        if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT ||
            !desc->wMaxPacketSize)
                return -EINVAL;

        pep = to_cdnsp_ep(ep);
        pdev = pep->pdev;
        pep->ep_state &= ~EP_UNCONFIGURED;

        if (dev_WARN_ONCE(pdev->dev, pep->ep_state & EP_ENABLED,
                          "%s is already enabled\n", pep->name))
                return 0;

        spin_lock_irqsave(&pdev->lock, flags);

        added_ctxs = cdnsp_get_endpoint_flag(desc);
        if (added_ctxs == SLOT_FLAG || added_ctxs == EP0_FLAG) {
                dev_err(pdev->dev, "ERROR: Bad endpoint number\n");
                ret = -EINVAL;
                goto unlock;
        }

        pep->interval = desc->bInterval ? BIT(desc->bInterval - 1) : 0;

        if (pdev->gadget.speed == USB_SPEED_FULL) {
                if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT)
                        pep->interval = desc->bInterval << 3;
                if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_ISOC)
                        pep->interval = BIT(desc->bInterval - 1) << 3;
        }

        if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_ISOC) {
                if (pep->interval > BIT(12)) {
                        dev_err(pdev->dev, "bInterval %d not supported\n",
                                desc->bInterval);
                        ret = -EINVAL;
                        goto unlock;
                }
                cdnsp_set_chicken_bits_2(pdev, CHICKEN_XDMA_2_TP_CACHE_DIS);
        }

        ret = cdnsp_endpoint_init(pdev, pep, GFP_ATOMIC);
        if (ret)
                goto unlock;

        ctrl_ctx = cdnsp_get_input_control_ctx(&pdev->in_ctx);
        ctrl_ctx->add_flags = cpu_to_le32(added_ctxs);
        ctrl_ctx->drop_flags = 0;

        ret = cdnsp_update_eps_configuration(pdev, pep);
        if (ret) {
                cdnsp_free_endpoint_rings(pdev, pep);
                goto unlock;
        }

        pep->ep_state |= EP_ENABLED;
        pep->ep_state &= ~EP_STOPPED;

unlock:
        trace_cdnsp_ep_enable_end(pep, 0);
        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

static int cdnsp_gadget_ep_disable(struct usb_ep *ep)
{
        struct cdnsp_input_control_ctx *ctrl_ctx;
        struct cdnsp_request *preq;
        struct cdnsp_device *pdev;
        struct cdnsp_ep *pep;
        unsigned long flags;
        u32 drop_flag;
        int ret = 0;

        if (!ep)
                return -EINVAL;

        pep = to_cdnsp_ep(ep);
        pdev = pep->pdev;

        spin_lock_irqsave(&pdev->lock, flags);

        if (!(pep->ep_state & EP_ENABLED)) {
                dev_err(pdev->dev, "%s is already disabled\n", pep->name);
                ret = -EINVAL;
                goto finish;
        }

        pep->ep_state |= EP_DIS_IN_RROGRESS;

        /* Endpoint was unconfigured by Reset Device command. */
        if (!(pep->ep_state & EP_UNCONFIGURED))
                cdnsp_cmd_stop_ep(pdev, pep);

        /* Remove all queued USB requests. */
        while (!list_empty(&pep->pending_list)) {
                preq = next_request(&pep->pending_list);
                cdnsp_ep_dequeue(pep, preq);
        }

        cdnsp_invalidate_ep_events(pdev, pep);

        pep->ep_state &= ~EP_DIS_IN_RROGRESS;
        drop_flag = cdnsp_get_endpoint_flag(pep->endpoint.desc);
        ctrl_ctx = cdnsp_get_input_control_ctx(&pdev->in_ctx);
        ctrl_ctx->drop_flags = cpu_to_le32(drop_flag);
        ctrl_ctx->add_flags = 0;

        cdnsp_endpoint_zero(pdev, pep);

        if (!(pep->ep_state & EP_UNCONFIGURED))
                ret = cdnsp_update_eps_configuration(pdev, pep);

        cdnsp_free_endpoint_rings(pdev, pep);

        pep->ep_state &= ~(EP_ENABLED | EP_UNCONFIGURED);
        pep->ep_state |= EP_STOPPED;

finish:
        trace_cdnsp_ep_disable_end(pep, 0);
        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

static struct usb_request *cdnsp_gadget_ep_alloc_request(struct usb_ep *ep,
                                                         gfp_t gfp_flags)
{
        struct cdnsp_ep *pep = to_cdnsp_ep(ep);
        struct cdnsp_request *preq;

        preq = kzalloc_obj(*preq, gfp_flags);
        if (!preq)
                return NULL;

        preq->epnum = pep->number;
        preq->pep = pep;

        trace_cdnsp_alloc_request(preq);

        return &preq->request;
}

static void cdnsp_gadget_ep_free_request(struct usb_ep *ep,
                                         struct usb_request *request)
{
        struct cdnsp_request *preq = to_cdnsp_request(request);

        trace_cdnsp_free_request(preq);
        kfree(preq);
}

static int cdnsp_gadget_ep_queue(struct usb_ep *ep,
                                 struct usb_request *request,
                                 gfp_t gfp_flags)
{
        struct cdnsp_request *preq;
        struct cdnsp_device *pdev;
        struct cdnsp_ep *pep;
        unsigned long flags;
        int ret;

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

        pep = to_cdnsp_ep(ep);
        pdev = pep->pdev;

        if (!(pep->ep_state & EP_ENABLED)) {
                dev_err(pdev->dev, "%s: can't queue to disabled endpoint\n",
                        pep->name);
                return -EINVAL;
        }

        preq = to_cdnsp_request(request);
        spin_lock_irqsave(&pdev->lock, flags);
        ret = cdnsp_ep_enqueue(pep, preq);
        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

static int cdnsp_gadget_ep_dequeue(struct usb_ep *ep,
                                   struct usb_request *request)
{
        struct cdnsp_ep *pep = to_cdnsp_ep(ep);
        struct cdnsp_device *pdev = pep->pdev;
        unsigned long flags;
        int ret;

        if (request->status != -EINPROGRESS)
                return 0;

        if (!pep->endpoint.desc) {
                dev_err(pdev->dev,
                        "%s: can't dequeue to disabled endpoint\n",
                        pep->name);
                return -ESHUTDOWN;
        }

        /* Requests has been dequeued during disabling endpoint. */
        if (!(pep->ep_state & EP_ENABLED))
                return 0;

        spin_lock_irqsave(&pdev->lock, flags);
        ret = cdnsp_ep_dequeue(pep, to_cdnsp_request(request));
        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

static int cdnsp_gadget_ep_set_halt(struct usb_ep *ep, int value)
{
        struct cdnsp_ep *pep = to_cdnsp_ep(ep);
        struct cdnsp_device *pdev = pep->pdev;
        struct cdnsp_request *preq;
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&pdev->lock, flags);

        preq = next_request(&pep->pending_list);
        if (value) {
                if (preq) {
                        trace_cdnsp_ep_busy_try_halt_again(pep, 0);
                        ret = -EAGAIN;
                        goto done;
                }
        }

        ret = cdnsp_halt_endpoint(pdev, pep, value);

done:
        spin_unlock_irqrestore(&pdev->lock, flags);
        return ret;
}

static int cdnsp_gadget_ep_set_wedge(struct usb_ep *ep)
{
        struct cdnsp_ep *pep = to_cdnsp_ep(ep);
        struct cdnsp_device *pdev = pep->pdev;
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&pdev->lock, flags);
        pep->ep_state |= EP_WEDGE;
        ret = cdnsp_halt_endpoint(pdev, pep, 1);
        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

static const struct usb_ep_ops cdnsp_gadget_ep0_ops = {
        .enable         = cdnsp_gadget_ep_enable,
        .disable        = cdnsp_gadget_ep_disable,
        .alloc_request  = cdnsp_gadget_ep_alloc_request,
        .free_request   = cdnsp_gadget_ep_free_request,
        .queue          = cdnsp_gadget_ep_queue,
        .dequeue        = cdnsp_gadget_ep_dequeue,
        .set_halt       = cdnsp_gadget_ep_set_halt,
        .set_wedge      = cdnsp_gadget_ep_set_wedge,
};

static const struct usb_ep_ops cdnsp_gadget_ep_ops = {
        .enable         = cdnsp_gadget_ep_enable,
        .disable        = cdnsp_gadget_ep_disable,
        .alloc_request  = cdnsp_gadget_ep_alloc_request,
        .free_request   = cdnsp_gadget_ep_free_request,
        .queue          = cdnsp_gadget_ep_queue,
        .dequeue        = cdnsp_gadget_ep_dequeue,
        .set_halt       = cdnsp_gadget_ep_set_halt,
        .set_wedge      = cdnsp_gadget_ep_set_wedge,
};

void cdnsp_gadget_giveback(struct cdnsp_ep *pep,
                           struct cdnsp_request *preq,
                           int status)
{
        struct cdnsp_device *pdev = pep->pdev;

        list_del(&preq->list);

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

        usb_gadget_unmap_request_by_dev(pdev->dev, &preq->request,
                                        preq->direction);

        trace_cdnsp_request_giveback(preq);

        if (preq != &pdev->ep0_preq) {
                spin_unlock(&pdev->lock);
                usb_gadget_giveback_request(&pep->endpoint, &preq->request);
                spin_lock(&pdev->lock);
        }
}

static struct usb_endpoint_descriptor cdnsp_gadget_ep0_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,
        .bmAttributes =         USB_ENDPOINT_XFER_CONTROL,
};

static int cdnsp_run(struct cdnsp_device *pdev,
                     enum usb_device_speed speed)
{
        u32 fs_speed = 0;
        u32 temp;
        int ret;

        temp = readl(&pdev->ir_set->irq_control);
        temp &= ~IMOD_INTERVAL_MASK;
        temp |= ((IMOD_DEFAULT_INTERVAL / 250) & IMOD_INTERVAL_MASK);
        writel(temp, &pdev->ir_set->irq_control);

        temp = readl(&pdev->port3x_regs->mode_addr);

        switch (speed) {
        case USB_SPEED_SUPER_PLUS:
                temp |= CFG_3XPORT_SSP_SUPPORT;
                break;
        case USB_SPEED_SUPER:
                temp &= ~CFG_3XPORT_SSP_SUPPORT;
                break;
        case USB_SPEED_HIGH:
                break;
        case USB_SPEED_FULL:
                fs_speed = PORT_REG6_FORCE_FS;
                break;
        default:
                dev_err(pdev->dev, "invalid maximum_speed parameter %d\n",
                        speed);
                fallthrough;
        case USB_SPEED_UNKNOWN:
                /* Default to superspeed. */
                speed = USB_SPEED_SUPER;
                break;
        }

        if (speed >= USB_SPEED_SUPER) {
                writel(temp, &pdev->port3x_regs->mode_addr);
                cdnsp_set_link_state(pdev, &pdev->usb3_port.regs->portsc,
                                     XDEV_RXDETECT);
        } else {
                cdnsp_disable_port(pdev, &pdev->usb3_port.regs->portsc);
        }

        cdnsp_set_link_state(pdev, &pdev->usb2_port.regs->portsc,
                             XDEV_RXDETECT);

        cdnsp_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);

        writel(PORT_REG6_L1_L0_HW_EN | fs_speed, &pdev->port20_regs->port_reg6);

        ret = cdnsp_start(pdev);
        if (ret) {
                ret = -ENODEV;
                goto err;
        }

        temp = readl(&pdev->op_regs->command);
        temp |= (CMD_INTE);
        writel(temp, &pdev->op_regs->command);

        temp = readl(&pdev->ir_set->irq_pending);
        writel(IMAN_IE_SET(temp), &pdev->ir_set->irq_pending);

        trace_cdnsp_init("Controller ready to work");
        return 0;
err:
        cdnsp_halt(pdev);
        return ret;
}

static int cdnsp_gadget_udc_start(struct usb_gadget *g,
                                  struct usb_gadget_driver *driver)
{
        enum usb_device_speed max_speed = driver->max_speed;
        struct cdnsp_device *pdev = gadget_to_cdnsp(g);
        unsigned long flags;
        int ret;

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

        /* limit speed if necessary */
        max_speed = min(driver->max_speed, g->max_speed);
        ret = cdnsp_run(pdev, max_speed);

        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

/*
 * Update Event Ring Dequeue Pointer:
 * - When all events have finished
 * - To avoid "Event Ring Full Error" condition
 */
void cdnsp_update_erst_dequeue(struct cdnsp_device *pdev,
                               union cdnsp_trb *event_ring_deq,
                               u8 clear_ehb)
{
        u64 temp_64;
        dma_addr_t deq;

        temp_64 = cdnsp_read_64(&pdev->ir_set->erst_dequeue);

        /* If necessary, update the HW's version of the event ring deq ptr. */
        if (event_ring_deq != pdev->event_ring->dequeue) {
                deq = cdnsp_trb_virt_to_dma(pdev->event_ring->deq_seg,
                                            pdev->event_ring->dequeue);
                temp_64 &= ERST_PTR_MASK;
                temp_64 |= ((u64)deq & (u64)~ERST_PTR_MASK);
        }

        /* Clear the event handler busy flag (RW1C). */
        if (clear_ehb)
                temp_64 |= ERST_EHB;
        else
                temp_64 &= ~ERST_EHB;

        cdnsp_write_64(temp_64, &pdev->ir_set->erst_dequeue);
}

static void cdnsp_clear_cmd_ring(struct cdnsp_device *pdev)
{
        struct cdnsp_segment *seg;
        u64 val_64;
        int i;

        cdnsp_initialize_ring_info(pdev->cmd_ring);

        seg = pdev->cmd_ring->first_seg;
        for (i = 0; i < pdev->cmd_ring->num_segs; i++) {
                memset(seg->trbs, 0,
                       sizeof(union cdnsp_trb) * (TRBS_PER_SEGMENT - 1));
                seg = seg->next;
        }

        /* Set the address in the Command Ring Control register. */
        val_64 = cdnsp_read_64(&pdev->op_regs->cmd_ring);
        val_64 = (val_64 & (u64)CMD_RING_RSVD_BITS) |
                 (pdev->cmd_ring->first_seg->dma & (u64)~CMD_RING_RSVD_BITS) |
                 pdev->cmd_ring->cycle_state;
        cdnsp_write_64(val_64, &pdev->op_regs->cmd_ring);
}

static void cdnsp_consume_all_events(struct cdnsp_device *pdev)
{
        struct cdnsp_segment *event_deq_seg;
        union cdnsp_trb *event_ring_deq;
        union cdnsp_trb *event;
        u32 cycle_bit;

        event_ring_deq = pdev->event_ring->dequeue;
        event_deq_seg = pdev->event_ring->deq_seg;
        event = pdev->event_ring->dequeue;

        /* Update ring dequeue pointer. */
        while (1) {
                cycle_bit = (le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE);

                /* Does the controller or driver own the TRB? */
                if (cycle_bit != pdev->event_ring->cycle_state)
                        break;

                cdnsp_inc_deq(pdev, pdev->event_ring);

                if (!cdnsp_last_trb_on_seg(event_deq_seg, event)) {
                        event++;
                        continue;
                }

                if (cdnsp_last_trb_on_ring(pdev->event_ring, event_deq_seg,
                                           event))
                        cycle_bit ^= 1;

                event_deq_seg = event_deq_seg->next;
                event = event_deq_seg->trbs;
        }

        cdnsp_update_erst_dequeue(pdev,  event_ring_deq, 1);
}

static void cdnsp_stop(struct cdnsp_device *pdev)
{
        u32 temp;

        /* Remove internally queued request for ep0. */
        if (!list_empty(&pdev->eps[0].pending_list)) {
                struct cdnsp_request *req;

                req = next_request(&pdev->eps[0].pending_list);
                if (req == &pdev->ep0_preq)
                        cdnsp_ep_dequeue(&pdev->eps[0], req);
        }

        cdnsp_disable_port(pdev, &pdev->usb2_port.regs->portsc);
        cdnsp_disable_port(pdev, &pdev->usb3_port.regs->portsc);
        cdnsp_disable_slot(pdev);
        cdnsp_halt(pdev);

        temp = readl(&pdev->op_regs->status);
        writel((temp & ~0x1fff) | STS_EINT, &pdev->op_regs->status);
        temp = readl(&pdev->ir_set->irq_pending);
        writel(IMAN_IE_CLEAR(temp), &pdev->ir_set->irq_pending);

        cdnsp_clear_port_change_bit(pdev, &pdev->usb2_port.regs->portsc);
        cdnsp_clear_port_change_bit(pdev, &pdev->usb3_port.regs->portsc);

        /* Clear interrupt line */
        temp = readl(&pdev->ir_set->irq_pending);
        temp |= IMAN_IP;
        writel(temp, &pdev->ir_set->irq_pending);

        cdnsp_consume_all_events(pdev);
        cdnsp_clear_cmd_ring(pdev);

        trace_cdnsp_exit("Controller stopped.");
}

/*
 * Stop controller.
 * This function is called by the gadget core when the driver is removed.
 * Disable slot, disable IRQs, and quiesce the controller.
 */
static int cdnsp_gadget_udc_stop(struct usb_gadget *g)
{
        struct cdnsp_device *pdev = gadget_to_cdnsp(g);
        unsigned long flags;

        spin_lock_irqsave(&pdev->lock, flags);
        cdnsp_stop(pdev);
        pdev->gadget_driver = NULL;
        spin_unlock_irqrestore(&pdev->lock, flags);

        return 0;
}

static int cdnsp_gadget_get_frame(struct usb_gadget *g)
{
        struct cdnsp_device *pdev = gadget_to_cdnsp(g);

        return cdnsp_get_frame(pdev);
}

static void __cdnsp_gadget_wakeup(struct cdnsp_device *pdev)
{
        struct cdnsp_port_regs __iomem *port_regs;
        u32 portpm, portsc;

        port_regs = pdev->active_port->regs;
        portsc = readl(&port_regs->portsc) & PORT_PLS_MASK;

        /* Remote wakeup feature is not enabled by host. */
        if (pdev->gadget.speed < USB_SPEED_SUPER && portsc == XDEV_U2) {
                portpm = readl(&port_regs->portpmsc);

                if (!(portpm & PORT_RWE))
                        return;
        }

        if (portsc == XDEV_U3 && !pdev->may_wakeup)
                return;

        cdnsp_set_link_state(pdev, &port_regs->portsc, XDEV_U0);

        pdev->cdnsp_state |= CDNSP_WAKEUP_PENDING;
}

static int cdnsp_gadget_wakeup(struct usb_gadget *g)
{
        struct cdnsp_device *pdev = gadget_to_cdnsp(g);
        unsigned long flags;

        spin_lock_irqsave(&pdev->lock, flags);
        __cdnsp_gadget_wakeup(pdev);
        spin_unlock_irqrestore(&pdev->lock, flags);

        return 0;
}

static int cdnsp_gadget_set_selfpowered(struct usb_gadget *g,
                                        int is_selfpowered)
{
        struct cdnsp_device *pdev = gadget_to_cdnsp(g);
        unsigned long flags;

        spin_lock_irqsave(&pdev->lock, flags);
        g->is_selfpowered = !!is_selfpowered;
        spin_unlock_irqrestore(&pdev->lock, flags);

        return 0;
}

static int cdnsp_gadget_pullup(struct usb_gadget *gadget, int is_on)
{
        struct cdnsp_device *pdev = gadget_to_cdnsp(gadget);
        struct cdns *cdns = dev_get_drvdata(pdev->dev);
        unsigned long flags;

        trace_cdnsp_pullup(is_on);

        /*
         * Disable events handling while controller is being
         * enabled/disabled.
         */
        disable_irq(cdns->dev_irq);
        spin_lock_irqsave(&pdev->lock, flags);

        if (!is_on) {
                cdnsp_reset_device(pdev);
                cdns_clear_vbus(cdns);
        } else {
                cdns_set_vbus(cdns);
        }

        spin_unlock_irqrestore(&pdev->lock, flags);
        enable_irq(cdns->dev_irq);

        return 0;
}

static const struct usb_gadget_ops cdnsp_gadget_ops = {
        .get_frame              = cdnsp_gadget_get_frame,
        .wakeup                 = cdnsp_gadget_wakeup,
        .set_selfpowered        = cdnsp_gadget_set_selfpowered,
        .pullup                 = cdnsp_gadget_pullup,
        .udc_start              = cdnsp_gadget_udc_start,
        .udc_stop               = cdnsp_gadget_udc_stop,
};

static void cdnsp_get_ep_buffering(struct cdnsp_device *pdev,
                                   struct cdnsp_ep *pep)
{
        void __iomem *reg = &pdev->cap_regs->hc_capbase;
        int endpoints;

        reg += cdnsp_find_next_ext_cap(reg, 0, XBUF_CAP_ID);

        if (!pep->direction) {
                pep->buffering = readl(reg + XBUF_RX_TAG_MASK_0_OFFSET);
                pep->buffering_period = readl(reg + XBUF_RX_TAG_MASK_1_OFFSET);
                pep->buffering = (pep->buffering + 1) / 2;
                pep->buffering_period = (pep->buffering_period + 1) / 2;
                return;
        }

        endpoints = HCS_ENDPOINTS(pdev->hcs_params1) / 2;

        /* Set to XBUF_TX_TAG_MASK_0 register. */
        reg += XBUF_TX_CMD_OFFSET + (endpoints * 2 + 2) * sizeof(u32);
        /* Set reg to XBUF_TX_TAG_MASK_N related with this endpoint. */
        reg += pep->number * sizeof(u32) * 2;

        pep->buffering = (readl(reg) + 1) / 2;
        pep->buffering_period = pep->buffering;
}

static int cdnsp_gadget_init_endpoints(struct cdnsp_device *pdev)
{
        int max_streams = HCC_MAX_PSA(pdev->hcc_params);
        struct cdnsp_ep *pep;
        int i;

        INIT_LIST_HEAD(&pdev->gadget.ep_list);

        if (max_streams < STREAM_LOG_STREAMS) {
                dev_err(pdev->dev, "Stream size %d not supported\n",
                        max_streams);
                return -EINVAL;
        }

        max_streams = STREAM_LOG_STREAMS;

        for (i = 0; i < CDNSP_ENDPOINTS_NUM; i++) {
                bool direction = !(i & 1); /* Start from OUT endpoint. */
                u8 epnum = ((i + 1) >> 1);

                if (!CDNSP_IF_EP_EXIST(pdev, epnum, direction))
                        continue;

                pep = &pdev->eps[i];
                pep->pdev = pdev;
                pep->number = epnum;
                pep->direction = direction; /* 0 for OUT, 1 for IN. */

                /*
                 * Ep0 is bidirectional, so ep0in and ep0out are represented by
                 * pdev->eps[0]
                 */
                if (epnum == 0) {
                        snprintf(pep->name, sizeof(pep->name), "ep%d%s",
                                 epnum, "BiDir");

                        pep->idx = 0;
                        usb_ep_set_maxpacket_limit(&pep->endpoint, 512);
                        pep->endpoint.maxburst = 1;
                        pep->endpoint.ops = &cdnsp_gadget_ep0_ops;
                        pep->endpoint.desc = &cdnsp_gadget_ep0_desc;
                        pep->endpoint.comp_desc = NULL;
                        pep->endpoint.caps.type_control = true;
                        pep->endpoint.caps.dir_in = true;
                        pep->endpoint.caps.dir_out = true;

                        pdev->ep0_preq.epnum = pep->number;
                        pdev->ep0_preq.pep = pep;
                        pdev->gadget.ep0 = &pep->endpoint;
                } else {
                        snprintf(pep->name, sizeof(pep->name), "ep%d%s",
                                 epnum, (pep->direction) ? "in" : "out");

                        pep->idx =  (epnum * 2 + (direction ? 1 : 0)) - 1;
                        usb_ep_set_maxpacket_limit(&pep->endpoint, 1024);

                        pep->endpoint.max_streams = max_streams;
                        pep->endpoint.ops = &cdnsp_gadget_ep_ops;
                        list_add_tail(&pep->endpoint.ep_list,
                                      &pdev->gadget.ep_list);

                        pep->endpoint.caps.type_iso = true;
                        pep->endpoint.caps.type_bulk = true;
                        pep->endpoint.caps.type_int = true;

                        pep->endpoint.caps.dir_in = direction;
                        pep->endpoint.caps.dir_out = !direction;
                }

                pep->endpoint.name = pep->name;
                pep->in_ctx = cdnsp_get_ep_ctx(&pdev->in_ctx, pep->idx);
                pep->out_ctx = cdnsp_get_ep_ctx(&pdev->out_ctx, pep->idx);
                cdnsp_get_ep_buffering(pdev, pep);

                dev_dbg(pdev->dev, "Init %s, MPS: %04x SupType: "
                        "CTRL: %s, INT: %s, BULK: %s, ISOC %s, "
                        "SupDir IN: %s, OUT: %s\n",
                        pep->name, 1024,
                        str_yes_no(pep->endpoint.caps.type_control),
                        str_yes_no(pep->endpoint.caps.type_int),
                        str_yes_no(pep->endpoint.caps.type_bulk),
                        str_yes_no(pep->endpoint.caps.type_iso),
                        str_yes_no(pep->endpoint.caps.dir_in),
                        str_yes_no(pep->endpoint.caps.dir_out));

                INIT_LIST_HEAD(&pep->pending_list);
        }

        return 0;
}

static void cdnsp_gadget_free_endpoints(struct cdnsp_device *pdev)
{
        struct cdnsp_ep *pep;
        int i;

        for (i = 0; i < CDNSP_ENDPOINTS_NUM; i++) {
                pep = &pdev->eps[i];
                if (pep->number != 0 && pep->out_ctx)
                        list_del(&pep->endpoint.ep_list);
        }
}

void cdnsp_disconnect_gadget(struct cdnsp_device *pdev)
{
        pdev->cdnsp_state |= CDNSP_STATE_DISCONNECT_PENDING;

        if (pdev->gadget_driver && pdev->gadget_driver->disconnect) {
                spin_unlock(&pdev->lock);
                pdev->gadget_driver->disconnect(&pdev->gadget);
                spin_lock(&pdev->lock);
        }

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

        pdev->cdnsp_state &= ~CDNSP_STATE_DISCONNECT_PENDING;
}

void cdnsp_suspend_gadget(struct cdnsp_device *pdev)
{
        if (pdev->gadget_driver && pdev->gadget_driver->suspend) {
                spin_unlock(&pdev->lock);
                pdev->gadget_driver->suspend(&pdev->gadget);
                spin_lock(&pdev->lock);
        }
}

void cdnsp_resume_gadget(struct cdnsp_device *pdev)
{
        if (pdev->gadget_driver && pdev->gadget_driver->resume) {
                spin_unlock(&pdev->lock);
                pdev->gadget_driver->resume(&pdev->gadget);
                spin_lock(&pdev->lock);
        }
}

void cdnsp_irq_reset(struct cdnsp_device *pdev)
{
        struct cdnsp_port_regs __iomem *port_regs;

        cdnsp_reset_device(pdev);

        port_regs = pdev->active_port->regs;
        pdev->gadget.speed = cdnsp_port_speed(readl(port_regs));

        spin_unlock(&pdev->lock);
        usb_gadget_udc_reset(&pdev->gadget, pdev->gadget_driver);
        spin_lock(&pdev->lock);

        switch (pdev->gadget.speed) {
        case USB_SPEED_SUPER_PLUS:
        case USB_SPEED_SUPER:
                cdnsp_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
                pdev->gadget.ep0->maxpacket = 512;
                break;
        case USB_SPEED_HIGH:
        case USB_SPEED_FULL:
                cdnsp_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
                pdev->gadget.ep0->maxpacket = 64;
                break;
        default:
                /* Low speed is not supported. */
                dev_err(pdev->dev, "Unknown device speed\n");
                break;
        }

        cdnsp_clear_chicken_bits_2(pdev, CHICKEN_XDMA_2_TP_CACHE_DIS);
        cdnsp_setup_device(pdev, SETUP_CONTEXT_ONLY);
        usb_gadget_set_state(&pdev->gadget, USB_STATE_DEFAULT);
}

static void cdnsp_get_rev_cap(struct cdnsp_device *pdev)
{
        void __iomem *reg = &pdev->cap_regs->hc_capbase;

        reg += cdnsp_find_next_ext_cap(reg, 0, RTL_REV_CAP);
        pdev->rev_cap  = reg;

        pdev->rtl_revision = readl(&pdev->rev_cap->rtl_revision);

        dev_info(pdev->dev, "Rev: %08x/%08x, eps: %08x, buff: %08x/%08x\n",
                 readl(&pdev->rev_cap->ctrl_revision),
                 readl(&pdev->rev_cap->rtl_revision),
                 readl(&pdev->rev_cap->ep_supported),
                 readl(&pdev->rev_cap->rx_buff_size),
                 readl(&pdev->rev_cap->tx_buff_size));
}

static int cdnsp_gen_setup(struct cdnsp_device *pdev)
{
        int ret;
        u32 reg;

        pdev->cap_regs = pdev->regs;
        pdev->op_regs = pdev->regs +
                HC_LENGTH(readl(&pdev->cap_regs->hc_capbase));
        pdev->run_regs = pdev->regs +
                (readl(&pdev->cap_regs->run_regs_off) & RTSOFF_MASK);

        /* Cache read-only capability registers */
        pdev->hcs_params1 = readl(&pdev->cap_regs->hcs_params1);
        pdev->hcc_params = readl(&pdev->cap_regs->hc_capbase);
        pdev->hci_version = HC_VERSION(pdev->hcc_params);
        pdev->hcc_params = readl(&pdev->cap_regs->hcc_params);

        /*
         * Override the APB timeout value to give the controller more time for
         * enabling UTMI clock and synchronizing APB and UTMI clock domains.
         * This fix is platform specific and is required to fixes issue with
         * reading incorrect value from PORTSC register after resuming
         * from L1 state.
         */
        cdnsp_set_apb_timeout_value(pdev);

        cdnsp_get_rev_cap(pdev);

        /* Make sure the Device Controller is halted. */
        ret = cdnsp_halt(pdev);
        if (ret)
                return ret;

        /* Reset the internal controller memory state and registers. */
        ret = cdnsp_reset(pdev);
        if (ret)
                return ret;

        /*
         * Set dma_mask and coherent_dma_mask to 64-bits,
         * if controller supports 64-bit addressing.
         */
        if (HCC_64BIT_ADDR(pdev->hcc_params) &&
            !dma_set_mask(pdev->dev, DMA_BIT_MASK(64))) {
                dev_dbg(pdev->dev, "Enabling 64-bit DMA addresses.\n");
                dma_set_coherent_mask(pdev->dev, DMA_BIT_MASK(64));
        } else {
                /*
                 * This is to avoid error in cases where a 32-bit USB
                 * controller is used on a 64-bit capable system.
                 */
                ret = dma_set_mask(pdev->dev, DMA_BIT_MASK(32));
                if (ret)
                        return ret;

                dev_dbg(pdev->dev, "Enabling 32-bit DMA addresses.\n");
                dma_set_coherent_mask(pdev->dev, DMA_BIT_MASK(32));
        }

        spin_lock_init(&pdev->lock);

        ret = cdnsp_mem_init(pdev);
        if (ret)
                return ret;

        /*
         * Software workaround for U1: after transition
         * to U1 the controller starts gating clock, and in some cases,
         * it causes that controller stack.
         */
        reg = readl(&pdev->port3x_regs->mode_2);
        reg &= ~CFG_3XPORT_U1_PIPE_CLK_GATE_EN;
        writel(reg, &pdev->port3x_regs->mode_2);

        return 0;
}

static int __cdnsp_gadget_init(struct cdns *cdns)
{
        struct cdnsp_device *pdev;
        u32 max_speed;
        int ret = -ENOMEM;

        cdns_drd_gadget_on(cdns);

        pdev = kzalloc_obj(*pdev);
        if (!pdev)
                return -ENOMEM;

        pm_runtime_get_sync(cdns->dev);

        cdns->gadget_dev = pdev;
        pdev->dev = cdns->dev;
        pdev->regs = cdns->dev_regs;
        max_speed = usb_get_maximum_speed(cdns->dev);

        switch (max_speed) {
        case USB_SPEED_FULL:
        case USB_SPEED_HIGH:
        case USB_SPEED_SUPER:
        case USB_SPEED_SUPER_PLUS:
                break;
        default:
                dev_err(cdns->dev, "invalid speed parameter %d\n", max_speed);
                fallthrough;
        case USB_SPEED_UNKNOWN:
                /* Default to SSP */
                max_speed = USB_SPEED_SUPER_PLUS;
                break;
        }

        pdev->gadget.ops = &cdnsp_gadget_ops;
        pdev->gadget.name = "cdnsp-gadget";
        pdev->gadget.speed = USB_SPEED_UNKNOWN;
        pdev->gadget.sg_supported = 1;
        pdev->gadget.max_speed = max_speed;
        pdev->gadget.lpm_capable = 1;

        pdev->setup_buf = kzalloc(CDNSP_EP0_SETUP_SIZE, GFP_KERNEL);
        if (!pdev->setup_buf)
                goto free_pdev;

        /*
         * Controller supports not aligned buffer but it should improve
         * performance.
         */
        pdev->gadget.quirk_ep_out_aligned_size = true;

        ret = cdnsp_gen_setup(pdev);
        if (ret) {
                dev_err(pdev->dev, "Generic initialization failed %d\n", ret);
                goto free_setup;
        }

        ret = cdnsp_gadget_init_endpoints(pdev);
        if (ret) {
                dev_err(pdev->dev, "failed to initialize endpoints\n");
                goto halt_pdev;
        }

        ret = usb_add_gadget_udc(pdev->dev, &pdev->gadget);
        if (ret) {
                dev_err(pdev->dev, "failed to register udc\n");
                goto free_endpoints;
        }

        ret = devm_request_threaded_irq(pdev->dev, cdns->dev_irq,
                                        cdnsp_irq_handler,
                                        cdnsp_thread_irq_handler, IRQF_SHARED,
                                        dev_name(pdev->dev), pdev);
        if (ret)
                goto del_gadget;

        return 0;

del_gadget:
        usb_del_gadget(&pdev->gadget);
        cdnsp_gadget_free_endpoints(pdev);
        usb_put_gadget(&pdev->gadget);
        goto halt_pdev;
free_endpoints:
        cdnsp_gadget_free_endpoints(pdev);
halt_pdev:
        cdnsp_halt(pdev);
        cdnsp_reset(pdev);
        cdnsp_mem_cleanup(pdev);
free_setup:
        kfree(pdev->setup_buf);
free_pdev:
        kfree(pdev);

        return ret;
}

static void cdnsp_gadget_exit(struct cdns *cdns)
{
        struct cdnsp_device *pdev = cdns->gadget_dev;

        devm_free_irq(pdev->dev, cdns->dev_irq, pdev);
        pm_runtime_put_autosuspend(cdns->dev);
        usb_del_gadget(&pdev->gadget);
        cdnsp_gadget_free_endpoints(pdev);
        usb_put_gadget(&pdev->gadget);
        cdnsp_mem_cleanup(pdev);
        kfree(pdev);
        cdns->gadget_dev = NULL;
        cdns_drd_gadget_off(cdns);
}

static int cdnsp_gadget_suspend(struct cdns *cdns, bool do_wakeup)
{
        struct cdnsp_device *pdev = cdns->gadget_dev;
        unsigned long flags;

        if (pdev->link_state == XDEV_U3)
                return 0;

        spin_lock_irqsave(&pdev->lock, flags);
        cdnsp_disconnect_gadget(pdev);
        cdnsp_stop(pdev);
        spin_unlock_irqrestore(&pdev->lock, flags);

        return 0;
}

static int cdnsp_gadget_resume(struct cdns *cdns, bool lost_power)
{
        struct cdnsp_device *pdev = cdns->gadget_dev;
        enum usb_device_speed max_speed;
        unsigned long flags;
        int ret;

        if (!pdev->gadget_driver)
                return 0;

        spin_lock_irqsave(&pdev->lock, flags);
        max_speed = pdev->gadget_driver->max_speed;

        /* Limit speed if necessary. */
        max_speed = min(max_speed, pdev->gadget.max_speed);

        ret = cdnsp_run(pdev, max_speed);

        if (pdev->link_state == XDEV_U3)
                __cdnsp_gadget_wakeup(pdev);

        spin_unlock_irqrestore(&pdev->lock, flags);

        return ret;
}

/**
 * cdnsp_gadget_init - initialize device structure
 * @cdns: cdnsp instance
 *
 * This function initializes the gadget.
 */
int cdnsp_gadget_init(struct cdns *cdns)
{
        struct cdns_role_driver *rdrv;

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

        rdrv->start     = __cdnsp_gadget_init;
        rdrv->stop      = cdnsp_gadget_exit;
        rdrv->suspend   = cdnsp_gadget_suspend;
        rdrv->resume    = cdnsp_gadget_resume;
        rdrv->state     = CDNS_ROLE_STATE_INACTIVE;
        rdrv->name      = "gadget";
        cdns->roles[USB_ROLE_DEVICE] = rdrv;

        return 0;
}