// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for the Atmel USBA high speed USB device controller
 *
 * Copyright (C) 2005-2007 Atmel Corporation
 */
#include <linux/clk.h>
#include <linux/clk/at91_pmc.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/mfd/syscon.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/ctype.h>
#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/irq.h>
#include <linux/gpio/consumer.h>

#include "atmel_usba_udc.h"
#define USBA_VBUS_IRQFLAGS (IRQF_ONESHOT \
                           | IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING)

#ifdef CONFIG_USB_GADGET_DEBUG_FS
#include <linux/debugfs.h>
#include <linux/uaccess.h>

static int queue_dbg_open(struct inode *inode, struct file *file)
{
        struct usba_ep *ep = inode->i_private;
        struct usba_request *req, *req_copy;
        struct list_head *queue_data;

        queue_data = kmalloc(sizeof(*queue_data), GFP_KERNEL);
        if (!queue_data)
                return -ENOMEM;
        INIT_LIST_HEAD(queue_data);

        spin_lock_irq(&ep->udc->lock);
        list_for_each_entry(req, &ep->queue, queue) {
                req_copy = kmemdup(req, sizeof(*req_copy), GFP_ATOMIC);
                if (!req_copy)
                        goto fail;
                list_add_tail(&req_copy->queue, queue_data);
        }
        spin_unlock_irq(&ep->udc->lock);

        file->private_data = queue_data;
        return 0;

fail:
        spin_unlock_irq(&ep->udc->lock);
        list_for_each_entry_safe(req, req_copy, queue_data, queue) {
                list_del(&req->queue);
                kfree(req);
        }
        kfree(queue_data);
        return -ENOMEM;
}

/*
 * bbbbbbbb llllllll IZS sssss nnnn FDL\n\0
 *
 * b: buffer address
 * l: buffer length
 * I/i: interrupt/no interrupt
 * Z/z: zero/no zero
 * S/s: short ok/short not ok
 * s: status
 * n: nr_packets
 * F/f: submitted/not submitted to FIFO
 * D/d: using/not using DMA
 * L/l: last transaction/not last transaction
 */
static ssize_t queue_dbg_read(struct file *file, char __user *buf,
                size_t nbytes, loff_t *ppos)
{
        struct list_head *queue = file->private_data;
        struct usba_request *req, *tmp_req;
        size_t len, remaining, actual = 0;
        char tmpbuf[38];

        if (!access_ok(buf, nbytes))
                return -EFAULT;

        inode_lock(file_inode(file));
        list_for_each_entry_safe(req, tmp_req, queue, queue) {
                len = snprintf(tmpbuf, sizeof(tmpbuf),
                                "%8p %08x %c%c%c %5d %c%c%c\n",
                                req->req.buf, req->req.length,
                                req->req.no_interrupt ? 'i' : 'I',
                                req->req.zero ? 'Z' : 'z',
                                req->req.short_not_ok ? 's' : 'S',
                                req->req.status,
                                req->submitted ? 'F' : 'f',
                                req->using_dma ? 'D' : 'd',
                                req->last_transaction ? 'L' : 'l');
                len = min(len, sizeof(tmpbuf));
                if (len > nbytes)
                        break;

                list_del(&req->queue);
                kfree(req);

                remaining = __copy_to_user(buf, tmpbuf, len);
                actual += len - remaining;
                if (remaining)
                        break;

                nbytes -= len;
                buf += len;
        }
        inode_unlock(file_inode(file));

        return actual;
}

static int queue_dbg_release(struct inode *inode, struct file *file)
{
        struct list_head *queue_data = file->private_data;
        struct usba_request *req, *tmp_req;

        list_for_each_entry_safe(req, tmp_req, queue_data, queue) {
                list_del(&req->queue);
                kfree(req);
        }
        kfree(queue_data);
        return 0;
}

static int regs_dbg_open(struct inode *inode, struct file *file)
{
        struct usba_udc *udc;
        unsigned int i;
        u32 *data;
        int ret = -ENOMEM;

        inode_lock(inode);
        udc = inode->i_private;
        data = kmalloc(inode->i_size, GFP_KERNEL);
        if (!data)
                goto out;

        spin_lock_irq(&udc->lock);
        for (i = 0; i < inode->i_size / 4; i++)
                data[i] = readl_relaxed(udc->regs + i * 4);
        spin_unlock_irq(&udc->lock);

        file->private_data = data;
        ret = 0;

out:
        inode_unlock(inode);

        return ret;
}

static ssize_t regs_dbg_read(struct file *file, char __user *buf,
                size_t nbytes, loff_t *ppos)
{
        struct inode *inode = file_inode(file);
        int ret;

        inode_lock(inode);
        ret = simple_read_from_buffer(buf, nbytes, ppos,
                        file->private_data,
                        file_inode(file)->i_size);
        inode_unlock(inode);

        return ret;
}

static int regs_dbg_release(struct inode *inode, struct file *file)
{
        kfree(file->private_data);
        return 0;
}

static const struct file_operations queue_dbg_fops = {
        .owner          = THIS_MODULE,
        .open           = queue_dbg_open,
        .llseek         = no_llseek,
        .read           = queue_dbg_read,
        .release        = queue_dbg_release,
};

static const struct file_operations regs_dbg_fops = {
        .owner          = THIS_MODULE,
        .open           = regs_dbg_open,
        .llseek         = generic_file_llseek,
        .read           = regs_dbg_read,
        .release        = regs_dbg_release,
};

static void usba_ep_init_debugfs(struct usba_udc *udc,
                struct usba_ep *ep)
{
        struct dentry *ep_root;

        ep_root = debugfs_create_dir(ep->ep.name, udc->debugfs_root);
        ep->debugfs_dir = ep_root;

        debugfs_create_file("queue", 0400, ep_root, ep, &queue_dbg_fops);
        if (ep->can_dma)
                debugfs_create_u32("dma_status", 0400, ep_root,
                                   &ep->last_dma_status);
        if (ep_is_control(ep))
                debugfs_create_u32("state", 0400, ep_root, &ep->state);
}

static void usba_ep_cleanup_debugfs(struct usba_ep *ep)
{
        debugfs_remove_recursive(ep->debugfs_dir);
}

static void usba_init_debugfs(struct usba_udc *udc)
{
        struct dentry *root;
        struct resource *regs_resource;

        root = debugfs_create_dir(udc->gadget.name, usb_debug_root);
        udc->debugfs_root = root;

        regs_resource = platform_get_resource(udc->pdev, IORESOURCE_MEM,
                                CTRL_IOMEM_ID);

        if (regs_resource) {
                debugfs_create_file_size("regs", 0400, root, udc,
                                         &regs_dbg_fops,
                                         resource_size(regs_resource));
        }

        usba_ep_init_debugfs(udc, to_usba_ep(udc->gadget.ep0));
}

static void usba_cleanup_debugfs(struct usba_udc *udc)
{
        usba_ep_cleanup_debugfs(to_usba_ep(udc->gadget.ep0));
        debugfs_remove_recursive(udc->debugfs_root);
}
#else
static inline void usba_ep_init_debugfs(struct usba_udc *udc,
                                         struct usba_ep *ep)
{

}

static inline void usba_ep_cleanup_debugfs(struct usba_ep *ep)
{

}

static inline void usba_init_debugfs(struct usba_udc *udc)
{

}

static inline void usba_cleanup_debugfs(struct usba_udc *udc)
{

}
#endif

static ushort fifo_mode;

module_param(fifo_mode, ushort, 0x0);
MODULE_PARM_DESC(fifo_mode, "Endpoint configuration mode");

/* mode 0 - uses autoconfig */

/* mode 1 - fits in 8KB, generic max fifo configuration */
static struct usba_fifo_cfg mode_1_cfg[] = {
{ .hw_ep_num = 0, .fifo_size = 64,      .nr_banks = 1, },
{ .hw_ep_num = 1, .fifo_size = 1024,    .nr_banks = 2, },
{ .hw_ep_num = 2, .fifo_size = 1024,    .nr_banks = 1, },
{ .hw_ep_num = 3, .fifo_size = 1024,    .nr_banks = 1, },
{ .hw_ep_num = 4, .fifo_size = 1024,    .nr_banks = 1, },
{ .hw_ep_num = 5, .fifo_size = 1024,    .nr_banks = 1, },
{ .hw_ep_num = 6, .fifo_size = 1024,    .nr_banks = 1, },
};

/* mode 2 - fits in 8KB, performance max fifo configuration */
static struct usba_fifo_cfg mode_2_cfg[] = {
{ .hw_ep_num = 0, .fifo_size = 64,      .nr_banks = 1, },
{ .hw_ep_num = 1, .fifo_size = 1024,    .nr_banks = 3, },
{ .hw_ep_num = 2, .fifo_size = 1024,    .nr_banks = 2, },
{ .hw_ep_num = 3, .fifo_size = 1024,    .nr_banks = 2, },
};

/* mode 3 - fits in 8KB, mixed fifo configuration */
static struct usba_fifo_cfg mode_3_cfg[] = {
{ .hw_ep_num = 0, .fifo_size = 64,      .nr_banks = 1, },
{ .hw_ep_num = 1, .fifo_size = 1024,    .nr_banks = 2, },
{ .hw_ep_num = 2, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 3, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 4, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 5, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 6, .fifo_size = 512,     .nr_banks = 2, },
};

/* mode 4 - fits in 8KB, custom fifo configuration */
static struct usba_fifo_cfg mode_4_cfg[] = {
{ .hw_ep_num = 0, .fifo_size = 64,      .nr_banks = 1, },
{ .hw_ep_num = 1, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 2, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 3, .fifo_size = 8,       .nr_banks = 2, },
{ .hw_ep_num = 4, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 5, .fifo_size = 512,     .nr_banks = 2, },
{ .hw_ep_num = 6, .fifo_size = 16,      .nr_banks = 2, },
{ .hw_ep_num = 7, .fifo_size = 8,       .nr_banks = 2, },
{ .hw_ep_num = 8, .fifo_size = 8,       .nr_banks = 2, },
};
/* Add additional configurations here */

static int usba_config_fifo_table(struct usba_udc *udc)
{
        int n;

        switch (fifo_mode) {
        default:
                fifo_mode = 0;
                fallthrough;
        case 0:
                udc->fifo_cfg = NULL;
                n = 0;
                break;
        case 1:
                udc->fifo_cfg = mode_1_cfg;
                n = ARRAY_SIZE(mode_1_cfg);
                break;
        case 2:
                udc->fifo_cfg = mode_2_cfg;
                n = ARRAY_SIZE(mode_2_cfg);
                break;
        case 3:
                udc->fifo_cfg = mode_3_cfg;
                n = ARRAY_SIZE(mode_3_cfg);
                break;
        case 4:
                udc->fifo_cfg = mode_4_cfg;
                n = ARRAY_SIZE(mode_4_cfg);
                break;
        }
        DBG(DBG_HW, "Setup fifo_mode %d\n", fifo_mode);

        return n;
}

static inline u32 usba_int_enb_get(struct usba_udc *udc)
{
        return udc->int_enb_cache;
}

static inline void usba_int_enb_set(struct usba_udc *udc, u32 mask)
{
        u32 val;

        val = udc->int_enb_cache | mask;
        usba_writel(udc, INT_ENB, val);
        udc->int_enb_cache = val;
}

static inline void usba_int_enb_clear(struct usba_udc *udc, u32 mask)
{
        u32 val;

        val = udc->int_enb_cache & ~mask;
        usba_writel(udc, INT_ENB, val);
        udc->int_enb_cache = val;
}

static int vbus_is_present(struct usba_udc *udc)
{
        if (udc->vbus_pin)
                return gpiod_get_value(udc->vbus_pin);

        /* No Vbus detection: Assume always present */
        return 1;
}

static void toggle_bias(struct usba_udc *udc, int is_on)
{
        if (udc->errata && udc->errata->toggle_bias)
                udc->errata->toggle_bias(udc, is_on);
}

static void generate_bias_pulse(struct usba_udc *udc)
{
        if (!udc->bias_pulse_needed)
                return;

        if (udc->errata && udc->errata->pulse_bias)
                udc->errata->pulse_bias(udc);

        udc->bias_pulse_needed = false;
}

static void next_fifo_transaction(struct usba_ep *ep, struct usba_request *req)
{
        unsigned int transaction_len;

        transaction_len = req->req.length - req->req.actual;
        req->last_transaction = 1;
        if (transaction_len > ep->ep.maxpacket) {
                transaction_len = ep->ep.maxpacket;
                req->last_transaction = 0;
        } else if (transaction_len == ep->ep.maxpacket && req->req.zero)
                req->last_transaction = 0;

        DBG(DBG_QUEUE, "%s: submit_transaction, req %p (length %d)%s\n",
                ep->ep.name, req, transaction_len,
                req->last_transaction ? ", done" : "");

        memcpy_toio(ep->fifo, req->req.buf + req->req.actual, transaction_len);
        usba_ep_writel(ep, SET_STA, USBA_TX_PK_RDY);
        req->req.actual += transaction_len;
}

static void submit_request(struct usba_ep *ep, struct usba_request *req)
{
        DBG(DBG_QUEUE, "%s: submit_request: req %p (length %d)\n",
                ep->ep.name, req, req->req.length);

        req->req.actual = 0;
        req->submitted = 1;

        if (req->using_dma) {
                if (req->req.length == 0) {
                        usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY);
                        return;
                }

                if (req->req.zero)
                        usba_ep_writel(ep, CTL_ENB, USBA_SHORT_PACKET);
                else
                        usba_ep_writel(ep, CTL_DIS, USBA_SHORT_PACKET);

                usba_dma_writel(ep, ADDRESS, req->req.dma);
                usba_dma_writel(ep, CONTROL, req->ctrl);
        } else {
                next_fifo_transaction(ep, req);
                if (req->last_transaction) {
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY);
                        if (ep_is_control(ep))
                                usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
                } else {
                        if (ep_is_control(ep))
                                usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
                        usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY);
                }
        }
}

static void submit_next_request(struct usba_ep *ep)
{
        struct usba_request *req;

        if (list_empty(&ep->queue)) {
                usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY | USBA_RX_BK_RDY);
                return;
        }

        req = list_entry(ep->queue.next, struct usba_request, queue);
        if (!req->submitted)
                submit_request(ep, req);
}

static void send_status(struct usba_udc *udc, struct usba_ep *ep)
{
        ep->state = STATUS_STAGE_IN;
        usba_ep_writel(ep, SET_STA, USBA_TX_PK_RDY);
        usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
}

static void receive_data(struct usba_ep *ep)
{
        struct usba_udc *udc = ep->udc;
        struct usba_request *req;
        unsigned long status;
        unsigned int bytecount, nr_busy;
        int is_complete = 0;

        status = usba_ep_readl(ep, STA);
        nr_busy = USBA_BFEXT(BUSY_BANKS, status);

        DBG(DBG_QUEUE, "receive data: nr_busy=%u\n", nr_busy);

        while (nr_busy > 0) {
                if (list_empty(&ep->queue)) {
                        usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);
                        break;
                }
                req = list_entry(ep->queue.next,
                                 struct usba_request, queue);

                bytecount = USBA_BFEXT(BYTE_COUNT, status);

                if (status & (1 << 31))
                        is_complete = 1;
                if (req->req.actual + bytecount >= req->req.length) {
                        is_complete = 1;
                        bytecount = req->req.length - req->req.actual;
                }

                memcpy_fromio(req->req.buf + req->req.actual,
                                ep->fifo, bytecount);
                req->req.actual += bytecount;

                usba_ep_writel(ep, CLR_STA, USBA_RX_BK_RDY);

                if (is_complete) {
                        DBG(DBG_QUEUE, "%s: request done\n", ep->ep.name);
                        req->req.status = 0;
                        list_del_init(&req->queue);
                        usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);
                        spin_unlock(&udc->lock);
                        usb_gadget_giveback_request(&ep->ep, &req->req);
                        spin_lock(&udc->lock);
                }

                status = usba_ep_readl(ep, STA);
                nr_busy = USBA_BFEXT(BUSY_BANKS, status);

                if (is_complete && ep_is_control(ep)) {
                        send_status(udc, ep);
                        break;
                }
        }
}

static void
request_complete(struct usba_ep *ep, struct usba_request *req, int status)
{
        struct usba_udc *udc = ep->udc;

        WARN_ON(!list_empty(&req->queue));

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

        if (req->using_dma)
                usb_gadget_unmap_request(&udc->gadget, &req->req, ep->is_in);

        DBG(DBG_GADGET | DBG_REQ,
                "%s: req %p complete: status %d, actual %u\n",
                ep->ep.name, req, req->req.status, req->req.actual);

        spin_unlock(&udc->lock);
        usb_gadget_giveback_request(&ep->ep, &req->req);
        spin_lock(&udc->lock);
}

static void
request_complete_list(struct usba_ep *ep, struct list_head *list, int status)
{
        struct usba_request *req, *tmp_req;

        list_for_each_entry_safe(req, tmp_req, list, queue) {
                list_del_init(&req->queue);
                request_complete(ep, req, status);
        }
}

static int
usba_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
        struct usba_ep *ep = to_usba_ep(_ep);
        struct usba_udc *udc = ep->udc;
        unsigned long flags, maxpacket;
        unsigned int nr_trans;

        DBG(DBG_GADGET, "%s: ep_enable: desc=%p\n", ep->ep.name, desc);

        maxpacket = usb_endpoint_maxp(desc);

        if (((desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) != ep->index)
                        || ep->index == 0
                        || desc->bDescriptorType != USB_DT_ENDPOINT
                        || maxpacket == 0
                        || maxpacket > ep->fifo_size) {
                DBG(DBG_ERR, "ep_enable: Invalid argument");
                return -EINVAL;
        }

        ep->is_isoc = 0;
        ep->is_in = 0;

        DBG(DBG_ERR, "%s: EPT_CFG = 0x%lx (maxpacket = %lu)\n",
                        ep->ep.name, ep->ept_cfg, maxpacket);

        if (usb_endpoint_dir_in(desc)) {
                ep->is_in = 1;
                ep->ept_cfg |= USBA_EPT_DIR_IN;
        }

        switch (usb_endpoint_type(desc)) {
        case USB_ENDPOINT_XFER_CONTROL:
                ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_CONTROL);
                break;
        case USB_ENDPOINT_XFER_ISOC:
                if (!ep->can_isoc) {
                        DBG(DBG_ERR, "ep_enable: %s is not isoc capable\n",
                                        ep->ep.name);
                        return -EINVAL;
                }

                /*
                 * Bits 11:12 specify number of _additional_
                 * transactions per microframe.
                 */
                nr_trans = usb_endpoint_maxp_mult(desc);
                if (nr_trans > 3)
                        return -EINVAL;

                ep->is_isoc = 1;
                ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_ISO);
                ep->ept_cfg |= USBA_BF(NB_TRANS, nr_trans);

                break;
        case USB_ENDPOINT_XFER_BULK:
                ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_BULK);
                break;
        case USB_ENDPOINT_XFER_INT:
                ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_INT);
                break;
        }

        spin_lock_irqsave(&ep->udc->lock, flags);

        ep->ep.desc = desc;
        ep->ep.maxpacket = maxpacket;

        usba_ep_writel(ep, CFG, ep->ept_cfg);
        usba_ep_writel(ep, CTL_ENB, USBA_EPT_ENABLE);

        if (ep->can_dma) {
                u32 ctrl;

                usba_int_enb_set(udc, USBA_BF(EPT_INT, 1 << ep->index) |
                                      USBA_BF(DMA_INT, 1 << ep->index));
                ctrl = USBA_AUTO_VALID | USBA_INTDIS_DMA;
                usba_ep_writel(ep, CTL_ENB, ctrl);
        } else {
                usba_int_enb_set(udc, USBA_BF(EPT_INT, 1 << ep->index));
        }

        spin_unlock_irqrestore(&udc->lock, flags);

        DBG(DBG_HW, "EPT_CFG%d after init: %#08lx\n", ep->index,
                        (unsigned long)usba_ep_readl(ep, CFG));
        DBG(DBG_HW, "INT_ENB after init: %#08lx\n",
                        (unsigned long)usba_int_enb_get(udc));

        return 0;
}

static int usba_ep_disable(struct usb_ep *_ep)
{
        struct usba_ep *ep = to_usba_ep(_ep);
        struct usba_udc *udc = ep->udc;
        LIST_HEAD(req_list);
        unsigned long flags;

        DBG(DBG_GADGET, "ep_disable: %s\n", ep->ep.name);

        spin_lock_irqsave(&udc->lock, flags);

        if (!ep->ep.desc) {
                spin_unlock_irqrestore(&udc->lock, flags);
                DBG(DBG_ERR, "ep_disable: %s not enabled\n", ep->ep.name);
                return -EINVAL;
        }
        ep->ep.desc = NULL;

        list_splice_init(&ep->queue, &req_list);
        if (ep->can_dma) {
                usba_dma_writel(ep, CONTROL, 0);
                usba_dma_writel(ep, ADDRESS, 0);
                usba_dma_readl(ep, STATUS);
        }
        usba_ep_writel(ep, CTL_DIS, USBA_EPT_ENABLE);
        usba_int_enb_clear(udc, USBA_BF(EPT_INT, 1 << ep->index));

        request_complete_list(ep, &req_list, -ESHUTDOWN);

        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
}

static struct usb_request *
usba_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct usba_request *req;

        DBG(DBG_GADGET, "ep_alloc_request: %p, 0x%x\n", _ep, gfp_flags);

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

        INIT_LIST_HEAD(&req->queue);

        return &req->req;
}

static void
usba_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
        struct usba_request *req = to_usba_req(_req);

        DBG(DBG_GADGET, "ep_free_request: %p, %p\n", _ep, _req);

        kfree(req);
}

static int queue_dma(struct usba_udc *udc, struct usba_ep *ep,
                struct usba_request *req, gfp_t gfp_flags)
{
        unsigned long flags;
        int ret;

        DBG(DBG_DMA, "%s: req l/%u d/%pad %c%c%c\n",
                ep->ep.name, req->req.length, &req->req.dma,
                req->req.zero ? 'Z' : 'z',
                req->req.short_not_ok ? 'S' : 's',
                req->req.no_interrupt ? 'I' : 'i');

        if (req->req.length > 0x10000) {
                /* Lengths from 0 to 65536 (inclusive) are supported */
                DBG(DBG_ERR, "invalid request length %u\n", req->req.length);
                return -EINVAL;
        }

        ret = usb_gadget_map_request(&udc->gadget, &req->req, ep->is_in);
        if (ret)
                return ret;

        req->using_dma = 1;
        req->ctrl = USBA_BF(DMA_BUF_LEN, req->req.length)
                        | USBA_DMA_CH_EN | USBA_DMA_END_BUF_IE
                        | USBA_DMA_END_BUF_EN;

        if (!ep->is_in)
                req->ctrl |= USBA_DMA_END_TR_EN | USBA_DMA_END_TR_IE;

        /*
         * Add this request to the queue and submit for DMA if
         * possible. Check if we're still alive first -- we may have
         * received a reset since last time we checked.
         */
        ret = -ESHUTDOWN;
        spin_lock_irqsave(&udc->lock, flags);
        if (ep->ep.desc) {
                if (list_empty(&ep->queue))
                        submit_request(ep, req);

                list_add_tail(&req->queue, &ep->queue);
                ret = 0;
        }
        spin_unlock_irqrestore(&udc->lock, flags);

        return ret;
}

static int
usba_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct usba_request *req = to_usba_req(_req);
        struct usba_ep *ep = to_usba_ep(_ep);
        struct usba_udc *udc = ep->udc;
        unsigned long flags;
        int ret;

        DBG(DBG_GADGET | DBG_QUEUE | DBG_REQ, "%s: queue req %p, len %u\n",
                        ep->ep.name, req, _req->length);

        if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN ||
            !ep->ep.desc)
                return -ESHUTDOWN;

        req->submitted = 0;
        req->using_dma = 0;
        req->last_transaction = 0;

        _req->status = -EINPROGRESS;
        _req->actual = 0;

        if (ep->can_dma)
                return queue_dma(udc, ep, req, gfp_flags);

        /* May have received a reset since last time we checked */
        ret = -ESHUTDOWN;
        spin_lock_irqsave(&udc->lock, flags);
        if (ep->ep.desc) {
                list_add_tail(&req->queue, &ep->queue);

                if ((!ep_is_control(ep) && ep->is_in) ||
                        (ep_is_control(ep)
                                && (ep->state == DATA_STAGE_IN
                                        || ep->state == STATUS_STAGE_IN)))
                        usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY);
                else
                        usba_ep_writel(ep, CTL_ENB, USBA_RX_BK_RDY);
                ret = 0;
        }
        spin_unlock_irqrestore(&udc->lock, flags);

        return ret;
}

static void
usba_update_req(struct usba_ep *ep, struct usba_request *req, u32 status)
{
        req->req.actual = req->req.length - USBA_BFEXT(DMA_BUF_LEN, status);
}

static int stop_dma(struct usba_ep *ep, u32 *pstatus)
{
        unsigned int timeout;
        u32 status;

        /*
         * Stop the DMA controller. When writing both CH_EN
         * and LINK to 0, the other bits are not affected.
         */
        usba_dma_writel(ep, CONTROL, 0);

        /* Wait for the FIFO to empty */
        for (timeout = 40; timeout; --timeout) {
                status = usba_dma_readl(ep, STATUS);
                if (!(status & USBA_DMA_CH_EN))
                        break;
                udelay(1);
        }

        if (pstatus)
                *pstatus = status;

        if (timeout == 0) {
                dev_err(&ep->udc->pdev->dev,
                        "%s: timed out waiting for DMA FIFO to empty\n",
                        ep->ep.name);
                return -ETIMEDOUT;
        }

        return 0;
}

static int usba_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct usba_ep *ep = to_usba_ep(_ep);
        struct usba_udc *udc = ep->udc;
        struct usba_request *req;
        unsigned long flags;
        u32 status;

        DBG(DBG_GADGET | DBG_QUEUE, "ep_dequeue: %s, req %p\n",
                        ep->ep.name, _req);

        spin_lock_irqsave(&udc->lock, flags);

        list_for_each_entry(req, &ep->queue, queue) {
                if (&req->req == _req)
                        break;
        }

        if (&req->req != _req) {
                spin_unlock_irqrestore(&udc->lock, flags);
                return -EINVAL;
        }

        if (req->using_dma) {
                /*
                 * If this request is currently being transferred,
                 * stop the DMA controller and reset the FIFO.
                 */
                if (ep->queue.next == &req->queue) {
                        status = usba_dma_readl(ep, STATUS);
                        if (status & USBA_DMA_CH_EN)
                                stop_dma(ep, &status);

#ifdef CONFIG_USB_GADGET_DEBUG_FS
                        ep->last_dma_status = status;
#endif

                        usba_writel(udc, EPT_RST, 1 << ep->index);

                        usba_update_req(ep, req, status);
                }
        }

        /*
         * Errors should stop the queue from advancing until the
         * completion function returns.
         */
        list_del_init(&req->queue);

        request_complete(ep, req, -ECONNRESET);

        /* Process the next request if any */
        submit_next_request(ep);
        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
}

static int usba_ep_set_halt(struct usb_ep *_ep, int value)
{
        struct usba_ep *ep = to_usba_ep(_ep);
        struct usba_udc *udc = ep->udc;
        unsigned long flags;
        int ret = 0;

        DBG(DBG_GADGET, "endpoint %s: %s HALT\n", ep->ep.name,
                        value ? "set" : "clear");

        if (!ep->ep.desc) {
                DBG(DBG_ERR, "Attempted to halt uninitialized ep %s\n",
                                ep->ep.name);
                return -ENODEV;
        }
        if (ep->is_isoc) {
                DBG(DBG_ERR, "Attempted to halt isochronous ep %s\n",
                                ep->ep.name);
                return -ENOTTY;
        }

        spin_lock_irqsave(&udc->lock, flags);

        /*
         * We can't halt IN endpoints while there are still data to be
         * transferred
         */
        if (!list_empty(&ep->queue)
                        || ((value && ep->is_in && (usba_ep_readl(ep, STA)
                                        & USBA_BF(BUSY_BANKS, -1L))))) {
                ret = -EAGAIN;
        } else {
                if (value)
                        usba_ep_writel(ep, SET_STA, USBA_FORCE_STALL);
                else
                        usba_ep_writel(ep, CLR_STA,
                                        USBA_FORCE_STALL | USBA_TOGGLE_CLR);
                usba_ep_readl(ep, STA);
        }

        spin_unlock_irqrestore(&udc->lock, flags);

        return ret;
}

static int usba_ep_fifo_status(struct usb_ep *_ep)
{
        struct usba_ep *ep = to_usba_ep(_ep);

        return USBA_BFEXT(BYTE_COUNT, usba_ep_readl(ep, STA));
}

static void usba_ep_fifo_flush(struct usb_ep *_ep)
{
        struct usba_ep *ep = to_usba_ep(_ep);
        struct usba_udc *udc = ep->udc;

        usba_writel(udc, EPT_RST, 1 << ep->index);
}

static const struct usb_ep_ops usba_ep_ops = {
        .enable         = usba_ep_enable,
        .disable        = usba_ep_disable,
        .alloc_request  = usba_ep_alloc_request,
        .free_request   = usba_ep_free_request,
        .queue          = usba_ep_queue,
        .dequeue        = usba_ep_dequeue,
        .set_halt       = usba_ep_set_halt,
        .fifo_status    = usba_ep_fifo_status,
        .fifo_flush     = usba_ep_fifo_flush,
};

static int usba_udc_get_frame(struct usb_gadget *gadget)
{
        struct usba_udc *udc = to_usba_udc(gadget);

        return USBA_BFEXT(FRAME_NUMBER, usba_readl(udc, FNUM));
}

static int usba_udc_wakeup(struct usb_gadget *gadget)
{
        struct usba_udc *udc = to_usba_udc(gadget);
        unsigned long flags;
        u32 ctrl;

        int ret = -EINVAL;

        spin_lock_irqsave(&udc->lock, flags);
        if (udc->devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
                ctrl = usba_readl(udc, CTRL);
                usba_writel(udc, CTRL, ctrl | USBA_REMOTE_WAKE_UP);
                ret = 0;
        }
        spin_unlock_irqrestore(&udc->lock, flags);

        return ret;
}

static int
usba_udc_set_selfpowered(struct usb_gadget *gadget, int is_selfpowered)
{
        struct usba_udc *udc = to_usba_udc(gadget);
        unsigned long flags;

        gadget->is_selfpowered = (is_selfpowered != 0);
        spin_lock_irqsave(&udc->lock, flags);
        if (is_selfpowered)
                udc->devstatus |= 1 << USB_DEVICE_SELF_POWERED;
        else
                udc->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
}

static int atmel_usba_pullup(struct usb_gadget *gadget, int is_on);
static int atmel_usba_start(struct usb_gadget *gadget,
                struct usb_gadget_driver *driver);
static int atmel_usba_stop(struct usb_gadget *gadget);

static struct usb_ep *atmel_usba_match_ep(struct usb_gadget *gadget,
                                struct usb_endpoint_descriptor  *desc,
                                struct usb_ss_ep_comp_descriptor *ep_comp)
{
        struct usb_ep   *_ep;
        struct usba_ep *ep;

        /* Look at endpoints until an unclaimed one looks usable */
        list_for_each_entry(_ep, &gadget->ep_list, ep_list) {
                if (usb_gadget_ep_match_desc(gadget, _ep, desc, ep_comp))
                        goto found_ep;
        }
        /* Fail */
        return NULL;

found_ep:

        if (fifo_mode == 0) {
                /* Optimize hw fifo size based on ep type and other info */
                ep = to_usba_ep(_ep);

                switch (usb_endpoint_type(desc)) {
                case USB_ENDPOINT_XFER_CONTROL:
                        break;

                case USB_ENDPOINT_XFER_ISOC:
                        ep->fifo_size = 1024;
                        ep->nr_banks = 2;
                        break;

                case USB_ENDPOINT_XFER_BULK:
                        ep->fifo_size = 512;
                        ep->nr_banks = 1;
                        break;

                case USB_ENDPOINT_XFER_INT:
                        if (desc->wMaxPacketSize == 0)
                                ep->fifo_size =
                                    roundup_pow_of_two(_ep->maxpacket_limit);
                        else
                                ep->fifo_size =
                                    roundup_pow_of_two(le16_to_cpu(desc->wMaxPacketSize));
                        ep->nr_banks = 1;
                        break;
                }

                /* It might be a little bit late to set this */
                usb_ep_set_maxpacket_limit(&ep->ep, ep->fifo_size);

                /* Generate ept_cfg basd on FIFO size and number of banks */
                if (ep->fifo_size  <= 8)
                        ep->ept_cfg = USBA_BF(EPT_SIZE, USBA_EPT_SIZE_8);
                else
                        /* LSB is bit 1, not 0 */
                        ep->ept_cfg =
                                USBA_BF(EPT_SIZE, fls(ep->fifo_size - 1) - 3);

                ep->ept_cfg |= USBA_BF(BK_NUMBER, ep->nr_banks);

                ep->udc->configured_ep++;
        }

        return _ep;
}

static const struct usb_gadget_ops usba_udc_ops = {
        .get_frame              = usba_udc_get_frame,
        .wakeup                 = usba_udc_wakeup,
        .set_selfpowered        = usba_udc_set_selfpowered,
        .pullup                 = atmel_usba_pullup,
        .udc_start              = atmel_usba_start,
        .udc_stop               = atmel_usba_stop,
        .match_ep               = atmel_usba_match_ep,
};

static struct usb_endpoint_descriptor usba_ep0_desc = {
        .bLength = USB_DT_ENDPOINT_SIZE,
        .bDescriptorType = USB_DT_ENDPOINT,
        .bEndpointAddress = 0,
        .bmAttributes = USB_ENDPOINT_XFER_CONTROL,
        .wMaxPacketSize = cpu_to_le16(64),
        /* FIXME: I have no idea what to put here */
        .bInterval = 1,
};

static const struct usb_gadget usba_gadget_template = {
        .ops            = &usba_udc_ops,
        .max_speed      = USB_SPEED_HIGH,
        .name           = "atmel_usba_udc",
};

/*
 * Called with interrupts disabled and udc->lock held.
 */
static void reset_all_endpoints(struct usba_udc *udc)
{
        struct usba_ep *ep;
        struct usba_request *req, *tmp_req;

        usba_writel(udc, EPT_RST, ~0UL);

        ep = to_usba_ep(udc->gadget.ep0);
        list_for_each_entry_safe(req, tmp_req, &ep->queue, queue) {
                list_del_init(&req->queue);
                request_complete(ep, req, -ECONNRESET);
        }
}

static struct usba_ep *get_ep_by_addr(struct usba_udc *udc, u16 wIndex)
{
        struct usba_ep *ep;

        if ((wIndex & USB_ENDPOINT_NUMBER_MASK) == 0)
                return to_usba_ep(udc->gadget.ep0);

        list_for_each_entry (ep, &udc->gadget.ep_list, ep.ep_list) {
                u8 bEndpointAddress;

                if (!ep->ep.desc)
                        continue;
                bEndpointAddress = ep->ep.desc->bEndpointAddress;
                if ((wIndex ^ bEndpointAddress) & USB_DIR_IN)
                        continue;
                if ((bEndpointAddress & USB_ENDPOINT_NUMBER_MASK)
                                == (wIndex & USB_ENDPOINT_NUMBER_MASK))
                        return ep;
        }

        return NULL;
}

/* Called with interrupts disabled and udc->lock held */
static inline void set_protocol_stall(struct usba_udc *udc, struct usba_ep *ep)
{
        usba_ep_writel(ep, SET_STA, USBA_FORCE_STALL);
        ep->state = WAIT_FOR_SETUP;
}

static inline int is_stalled(struct usba_udc *udc, struct usba_ep *ep)
{
        if (usba_ep_readl(ep, STA) & USBA_FORCE_STALL)
                return 1;
        return 0;
}

static inline void set_address(struct usba_udc *udc, unsigned int addr)
{
        u32 regval;

        DBG(DBG_BUS, "setting address %u...\n", addr);
        regval = usba_readl(udc, CTRL);
        regval = USBA_BFINS(DEV_ADDR, addr, regval);
        usba_writel(udc, CTRL, regval);
}

static int do_test_mode(struct usba_udc *udc)
{
        static const char test_packet_buffer[] = {
                /* JKJKJKJK * 9 */
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                /* JJKKJJKK * 8 */
                0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
                /* JJKKJJKK * 8 */
                0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE,
                /* JJJJJJJKKKKKKK * 8 */
                0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
                0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
                /* JJJJJJJK * 8 */
                0x7F, 0xBF, 0xDF, 0xEF, 0xF7, 0xFB, 0xFD,
                /* {JKKKKKKK * 10}, JK */
                0xFC, 0x7E, 0xBF, 0xDF, 0xEF, 0xF7, 0xFB, 0xFD, 0x7E
        };
        struct usba_ep *ep;
        struct device *dev = &udc->pdev->dev;
        int test_mode;

        test_mode = udc->test_mode;

        /* Start from a clean slate */
        reset_all_endpoints(udc);

        switch (test_mode) {
        case 0x0100:
                /* Test_J */
                usba_writel(udc, TST, USBA_TST_J_MODE);
                dev_info(dev, "Entering Test_J mode...\n");
                break;
        case 0x0200:
                /* Test_K */
                usba_writel(udc, TST, USBA_TST_K_MODE);
                dev_info(dev, "Entering Test_K mode...\n");
                break;
        case 0x0300:
                /*
                 * Test_SE0_NAK: Force high-speed mode and set up ep0
                 * for Bulk IN transfers
                 */
                ep = &udc->usba_ep[0];
                usba_writel(udc, TST,
                                USBA_BF(SPEED_CFG, USBA_SPEED_CFG_FORCE_HIGH));
                usba_ep_writel(ep, CFG,
                                USBA_BF(EPT_SIZE, USBA_EPT_SIZE_64)
                                | USBA_EPT_DIR_IN
                                | USBA_BF(EPT_TYPE, USBA_EPT_TYPE_BULK)
                                | USBA_BF(BK_NUMBER, 1));
                if (!(usba_ep_readl(ep, CFG) & USBA_EPT_MAPPED)) {
                        set_protocol_stall(udc, ep);
                        dev_err(dev, "Test_SE0_NAK: ep0 not mapped\n");
                } else {
                        usba_ep_writel(ep, CTL_ENB, USBA_EPT_ENABLE);
                        dev_info(dev, "Entering Test_SE0_NAK mode...\n");
                }
                break;
        case 0x0400:
                /* Test_Packet */
                ep = &udc->usba_ep[0];
                usba_ep_writel(ep, CFG,
                                USBA_BF(EPT_SIZE, USBA_EPT_SIZE_64)
                                | USBA_EPT_DIR_IN
                                | USBA_BF(EPT_TYPE, USBA_EPT_TYPE_BULK)
                                | USBA_BF(BK_NUMBER, 1));
                if (!(usba_ep_readl(ep, CFG) & USBA_EPT_MAPPED)) {
                        set_protocol_stall(udc, ep);
                        dev_err(dev, "Test_Packet: ep0 not mapped\n");
                } else {
                        usba_ep_writel(ep, CTL_ENB, USBA_EPT_ENABLE);
                        usba_writel(udc, TST, USBA_TST_PKT_MODE);
                        memcpy_toio(ep->fifo, test_packet_buffer,
                                        sizeof(test_packet_buffer));
                        usba_ep_writel(ep, SET_STA, USBA_TX_PK_RDY);
                        dev_info(dev, "Entering Test_Packet mode...\n");
                }
                break;
        default:
                dev_err(dev, "Invalid test mode: 0x%04x\n", test_mode);
                return -EINVAL;
        }

        return 0;
}

/* Avoid overly long expressions */
static inline bool feature_is_dev_remote_wakeup(struct usb_ctrlrequest *crq)
{
        if (crq->wValue == cpu_to_le16(USB_DEVICE_REMOTE_WAKEUP))
                return true;
        return false;
}

static inline bool feature_is_dev_test_mode(struct usb_ctrlrequest *crq)
{
        if (crq->wValue == cpu_to_le16(USB_DEVICE_TEST_MODE))
                return true;
        return false;
}

static inline bool feature_is_ep_halt(struct usb_ctrlrequest *crq)
{
        if (crq->wValue == cpu_to_le16(USB_ENDPOINT_HALT))
                return true;
        return false;
}

static int handle_ep0_setup(struct usba_udc *udc, struct usba_ep *ep,
                struct usb_ctrlrequest *crq)
{
        int retval = 0;

        switch (crq->bRequest) {
        case USB_REQ_GET_STATUS: {
                u16 status;

                if (crq->bRequestType == (USB_DIR_IN | USB_RECIP_DEVICE)) {
                        status = cpu_to_le16(udc->devstatus);
                } else if (crq->bRequestType
                                == (USB_DIR_IN | USB_RECIP_INTERFACE)) {
                        status = cpu_to_le16(0);
                } else if (crq->bRequestType
                                == (USB_DIR_IN | USB_RECIP_ENDPOINT)) {
                        struct usba_ep *target;

                        target = get_ep_by_addr(udc, le16_to_cpu(crq->wIndex));
                        if (!target)
                                goto stall;

                        status = 0;
                        if (is_stalled(udc, target))
                                status |= cpu_to_le16(1);
                } else
                        goto delegate;

                /* Write directly to the FIFO. No queueing is done. */
                if (crq->wLength != cpu_to_le16(sizeof(status)))
                        goto stall;
                ep->state = DATA_STAGE_IN;
                writew_relaxed(status, ep->fifo);
                usba_ep_writel(ep, SET_STA, USBA_TX_PK_RDY);
                break;
        }

        case USB_REQ_CLEAR_FEATURE: {
                if (crq->bRequestType == USB_RECIP_DEVICE) {
                        if (feature_is_dev_remote_wakeup(crq))
                                udc->devstatus
                                        &= ~(1 << USB_DEVICE_REMOTE_WAKEUP);
                        else
                                /* Can't CLEAR_FEATURE TEST_MODE */
                                goto stall;
                } else if (crq->bRequestType == USB_RECIP_ENDPOINT) {
                        struct usba_ep *target;

                        if (crq->wLength != cpu_to_le16(0)
                                        || !feature_is_ep_halt(crq))
                                goto stall;
                        target = get_ep_by_addr(udc, le16_to_cpu(crq->wIndex));
                        if (!target)
                                goto stall;

                        usba_ep_writel(target, CLR_STA, USBA_FORCE_STALL);
                        if (target->index != 0)
                                usba_ep_writel(target, CLR_STA,
                                                USBA_TOGGLE_CLR);
                } else {
                        goto delegate;
                }

                send_status(udc, ep);
                break;
        }

        case USB_REQ_SET_FEATURE: {
                if (crq->bRequestType == USB_RECIP_DEVICE) {
                        if (feature_is_dev_test_mode(crq)) {
                                send_status(udc, ep);
                                ep->state = STATUS_STAGE_TEST;
                                udc->test_mode = le16_to_cpu(crq->wIndex);
                                return 0;
                        } else if (feature_is_dev_remote_wakeup(crq)) {
                                udc->devstatus |= 1 << USB_DEVICE_REMOTE_WAKEUP;
                        } else {
                                goto stall;
                        }
                } else if (crq->bRequestType == USB_RECIP_ENDPOINT) {
                        struct usba_ep *target;

                        if (crq->wLength != cpu_to_le16(0)
                                        || !feature_is_ep_halt(crq))
                                goto stall;

                        target = get_ep_by_addr(udc, le16_to_cpu(crq->wIndex));
                        if (!target)
                                goto stall;

                        usba_ep_writel(target, SET_STA, USBA_FORCE_STALL);
                } else
                        goto delegate;

                send_status(udc, ep);
                break;
        }

        case USB_REQ_SET_ADDRESS:
                if (crq->bRequestType != (USB_DIR_OUT | USB_RECIP_DEVICE))
                        goto delegate;

                set_address(udc, le16_to_cpu(crq->wValue));
                send_status(udc, ep);
                ep->state = STATUS_STAGE_ADDR;
                break;

        default:
delegate:
                spin_unlock(&udc->lock);
                retval = udc->driver->setup(&udc->gadget, crq);
                spin_lock(&udc->lock);
        }

        return retval;

stall:
        pr_err("udc: %s: Invalid setup request: %02x.%02x v%04x i%04x l%d, "
                "halting endpoint...\n",
                ep->ep.name, crq->bRequestType, crq->bRequest,
                le16_to_cpu(crq->wValue), le16_to_cpu(crq->wIndex),
                le16_to_cpu(crq->wLength));
        set_protocol_stall(udc, ep);
        return -1;
}

static void usba_control_irq(struct usba_udc *udc, struct usba_ep *ep)
{
        struct usba_request *req;
        u32 epstatus;
        u32 epctrl;

restart:
        epstatus = usba_ep_readl(ep, STA);
        epctrl = usba_ep_readl(ep, CTL);

        DBG(DBG_INT, "%s [%d]: s/%08x c/%08x\n",
                        ep->ep.name, ep->state, epstatus, epctrl);

        req = NULL;
        if (!list_empty(&ep->queue))
                req = list_entry(ep->queue.next,
                                 struct usba_request, queue);

        if ((epctrl & USBA_TX_PK_RDY) && !(epstatus & USBA_TX_PK_RDY)) {
                if (req->submitted)
                        next_fifo_transaction(ep, req);
                else
                        submit_request(ep, req);

                if (req->last_transaction) {
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY);
                        usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
                }
                goto restart;
        }
        if ((epstatus & epctrl) & USBA_TX_COMPLETE) {
                usba_ep_writel(ep, CLR_STA, USBA_TX_COMPLETE);

                switch (ep->state) {
                case DATA_STAGE_IN:
                        usba_ep_writel(ep, CTL_ENB, USBA_RX_BK_RDY);
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
                        ep->state = STATUS_STAGE_OUT;
                        break;
                case STATUS_STAGE_ADDR:
                        /* Activate our new address */
                        usba_writel(udc, CTRL, (usba_readl(udc, CTRL)
                                                | USBA_FADDR_EN));
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
                        ep->state = WAIT_FOR_SETUP;
                        break;
                case STATUS_STAGE_IN:
                        if (req) {
                                list_del_init(&req->queue);
                                request_complete(ep, req, 0);
                                submit_next_request(ep);
                        }
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
                        ep->state = WAIT_FOR_SETUP;
                        break;
                case STATUS_STAGE_TEST:
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
                        ep->state = WAIT_FOR_SETUP;
                        if (do_test_mode(udc))
                                set_protocol_stall(udc, ep);
                        break;
                default:
                        pr_err("udc: %s: TXCOMP: Invalid endpoint state %d, "
                                "halting endpoint...\n",
                                ep->ep.name, ep->state);
                        set_protocol_stall(udc, ep);
                        break;
                }

                goto restart;
        }
        if ((epstatus & epctrl) & USBA_RX_BK_RDY) {
                switch (ep->state) {
                case STATUS_STAGE_OUT:
                        usba_ep_writel(ep, CLR_STA, USBA_RX_BK_RDY);
                        usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);

                        if (req) {
                                list_del_init(&req->queue);
                                request_complete(ep, req, 0);
                        }
                        ep->state = WAIT_FOR_SETUP;
                        break;

                case DATA_STAGE_OUT:
                        receive_data(ep);
                        break;

                default:
                        usba_ep_writel(ep, CLR_STA, USBA_RX_BK_RDY);
                        usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);
                        pr_err("udc: %s: RXRDY: Invalid endpoint state %d, "
                                "halting endpoint...\n",
                                ep->ep.name, ep->state);
                        set_protocol_stall(udc, ep);
                        break;
                }

                goto restart;
        }
        if (epstatus & USBA_RX_SETUP) {
                union {
                        struct usb_ctrlrequest crq;
                        unsigned long data[2];
                } crq;
                unsigned int pkt_len;
                int ret;

                if (ep->state != WAIT_FOR_SETUP) {
                        /*
                         * Didn't expect a SETUP packet at this
                         * point. Clean up any pending requests (which
                         * may be successful).
                         */
                        int status = -EPROTO;

                        /*
                         * RXRDY and TXCOMP are dropped when SETUP
                         * packets arrive.  Just pretend we received
                         * the status packet.
                         */
                        if (ep->state == STATUS_STAGE_OUT
                                        || ep->state == STATUS_STAGE_IN) {
                                usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);
                                status = 0;
                        }

                        if (req) {
                                list_del_init(&req->queue);
                                request_complete(ep, req, status);
                        }
                }

                pkt_len = USBA_BFEXT(BYTE_COUNT, usba_ep_readl(ep, STA));
                DBG(DBG_HW, "Packet length: %u\n", pkt_len);
                if (pkt_len != sizeof(crq)) {
                        pr_warn("udc: Invalid packet length %u (expected %zu)\n",
                                pkt_len, sizeof(crq));
                        set_protocol_stall(udc, ep);
                        return;
                }

                DBG(DBG_FIFO, "Copying ctrl request from 0x%p:\n", ep->fifo);
                memcpy_fromio(crq.data, ep->fifo, sizeof(crq));

                /* Free up one bank in the FIFO so that we can
                 * generate or receive a reply right away. */
                usba_ep_writel(ep, CLR_STA, USBA_RX_SETUP);

                /* printk(KERN_DEBUG "setup: %d: %02x.%02x\n",
                        ep->state, crq.crq.bRequestType,
                        crq.crq.bRequest); */

                if (crq.crq.bRequestType & USB_DIR_IN) {
                        /*
                         * The USB 2.0 spec states that "if wLength is
                         * zero, there is no data transfer phase."
                         * However, testusb #14 seems to actually
                         * expect a data phase even if wLength = 0...
                         */
                        ep->state = DATA_STAGE_IN;
                } else {
                        if (crq.crq.wLength != cpu_to_le16(0))
                                ep->state = DATA_STAGE_OUT;
                        else
                                ep->state = STATUS_STAGE_IN;
                }

                ret = -1;
                if (ep->index == 0)
                        ret = handle_ep0_setup(udc, ep, &crq.crq);
                else {
                        spin_unlock(&udc->lock);
                        ret = udc->driver->setup(&udc->gadget, &crq.crq);
                        spin_lock(&udc->lock);
                }

                DBG(DBG_BUS, "req %02x.%02x, length %d, state %d, ret %d\n",
                        crq.crq.bRequestType, crq.crq.bRequest,
                        le16_to_cpu(crq.crq.wLength), ep->state, ret);

                if (ret < 0) {
                        /* Let the host know that we failed */
                        set_protocol_stall(udc, ep);
                }
        }
}

static void usba_ep_irq(struct usba_udc *udc, struct usba_ep *ep)
{
        struct usba_request *req;
        u32 epstatus;
        u32 epctrl;

        epstatus = usba_ep_readl(ep, STA);
        epctrl = usba_ep_readl(ep, CTL);

        DBG(DBG_INT, "%s: interrupt, status: 0x%08x\n", ep->ep.name, epstatus);

        while ((epctrl & USBA_TX_PK_RDY) && !(epstatus & USBA_TX_PK_RDY)) {
                DBG(DBG_BUS, "%s: TX PK ready\n", ep->ep.name);

                if (list_empty(&ep->queue)) {
                        dev_warn(&udc->pdev->dev, "ep_irq: queue empty\n");
                        usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY);
                        return;
                }

                req = list_entry(ep->queue.next, struct usba_request, queue);

                if (req->using_dma) {
                        /* Send a zero-length packet */
                        usba_ep_writel(ep, SET_STA,
                                        USBA_TX_PK_RDY);
                        usba_ep_writel(ep, CTL_DIS,
                                        USBA_TX_PK_RDY);
                        list_del_init(&req->queue);
                        submit_next_request(ep);
                        request_complete(ep, req, 0);
                } else {
                        if (req->submitted)
                                next_fifo_transaction(ep, req);
                        else
                                submit_request(ep, req);

                        if (req->last_transaction) {
                                list_del_init(&req->queue);
                                submit_next_request(ep);
                                request_complete(ep, req, 0);
                        }
                }

                epstatus = usba_ep_readl(ep, STA);
                epctrl = usba_ep_readl(ep, CTL);
        }
        if ((epstatus & epctrl) & USBA_RX_BK_RDY) {
                DBG(DBG_BUS, "%s: RX data ready\n", ep->ep.name);
                receive_data(ep);
        }
}

static void usba_dma_irq(struct usba_udc *udc, struct usba_ep *ep)
{
        struct usba_request *req;
        u32 status, control, pending;

        status = usba_dma_readl(ep, STATUS);
        control = usba_dma_readl(ep, CONTROL);
#ifdef CONFIG_USB_GADGET_DEBUG_FS
        ep->last_dma_status = status;
#endif
        pending = status & control;
        DBG(DBG_INT | DBG_DMA, "dma irq, s/%#08x, c/%#08x\n", status, control);

        if (status & USBA_DMA_CH_EN) {
                dev_err(&udc->pdev->dev,
                        "DMA_CH_EN is set after transfer is finished!\n");
                dev_err(&udc->pdev->dev,
                        "status=%#08x, pending=%#08x, control=%#08x\n",
                        status, pending, control);

                /*
                 * try to pretend nothing happened. We might have to
                 * do something here...
                 */
        }

        if (list_empty(&ep->queue))
                /* Might happen if a reset comes along at the right moment */
                return;

        if (pending & (USBA_DMA_END_TR_ST | USBA_DMA_END_BUF_ST)) {
                req = list_entry(ep->queue.next, struct usba_request, queue);
                usba_update_req(ep, req, status);

                list_del_init(&req->queue);
                submit_next_request(ep);
                request_complete(ep, req, 0);
        }
}

static int start_clock(struct usba_udc *udc);
static void stop_clock(struct usba_udc *udc);

static irqreturn_t usba_udc_irq(int irq, void *devid)
{
        struct usba_udc *udc = devid;
        u32 status, int_enb;
        u32 dma_status;
        u32 ep_status;

        spin_lock(&udc->lock);

        int_enb = usba_int_enb_get(udc);
        status = usba_readl(udc, INT_STA) & (int_enb | USBA_HIGH_SPEED);
        DBG(DBG_INT, "irq, status=%#08x\n", status);

        if (status & USBA_DET_SUSPEND) {
                usba_writel(udc, INT_CLR, USBA_DET_SUSPEND|USBA_WAKE_UP);
                usba_int_enb_set(udc, USBA_WAKE_UP);
                usba_int_enb_clear(udc, USBA_DET_SUSPEND);
                udc->suspended = true;
                toggle_bias(udc, 0);
                udc->bias_pulse_needed = true;
                stop_clock(udc);
                DBG(DBG_BUS, "Suspend detected\n");
                if (udc->gadget.speed != USB_SPEED_UNKNOWN
                                && udc->driver && udc->driver->suspend) {
                        spin_unlock(&udc->lock);
                        udc->driver->suspend(&udc->gadget);
                        spin_lock(&udc->lock);
                }
        }

        if (status & USBA_WAKE_UP) {
                start_clock(udc);
                toggle_bias(udc, 1);
                usba_writel(udc, INT_CLR, USBA_WAKE_UP);
                DBG(DBG_BUS, "Wake Up CPU detected\n");
        }

        if (status & USBA_END_OF_RESUME) {
                udc->suspended = false;
                usba_writel(udc, INT_CLR, USBA_END_OF_RESUME);
                usba_int_enb_clear(udc, USBA_WAKE_UP);
                usba_int_enb_set(udc, USBA_DET_SUSPEND);
                generate_bias_pulse(udc);
                DBG(DBG_BUS, "Resume detected\n");
                if (udc->gadget.speed != USB_SPEED_UNKNOWN
                                && udc->driver && udc->driver->resume) {
                        spin_unlock(&udc->lock);
                        udc->driver->resume(&udc->gadget);
                        spin_lock(&udc->lock);
                }
        }

        dma_status = USBA_BFEXT(DMA_INT, status);
        if (dma_status) {
                int i;

                usba_int_enb_set(udc, USBA_DET_SUSPEND);

                for (i = 1; i <= USBA_NR_DMAS; i++)
                        if (dma_status & (1 << i))
                                usba_dma_irq(udc, &udc->usba_ep[i]);
        }

        ep_status = USBA_BFEXT(EPT_INT, status);
        if (ep_status) {
                int i;

                usba_int_enb_set(udc, USBA_DET_SUSPEND);

                for (i = 0; i < udc->num_ep; i++)
                        if (ep_status & (1 << i)) {
                                if (ep_is_control(&udc->usba_ep[i]))
                                        usba_control_irq(udc, &udc->usba_ep[i]);
                                else
                                        usba_ep_irq(udc, &udc->usba_ep[i]);
                        }
        }

        if (status & USBA_END_OF_RESET) {
                struct usba_ep *ep0, *ep;
                int i, n;

                usba_writel(udc, INT_CLR,
                        USBA_END_OF_RESET|USBA_END_OF_RESUME
                        |USBA_DET_SUSPEND|USBA_WAKE_UP);
                generate_bias_pulse(udc);
                reset_all_endpoints(udc);

                if (udc->gadget.speed != USB_SPEED_UNKNOWN && udc->driver) {
                        udc->gadget.speed = USB_SPEED_UNKNOWN;
                        spin_unlock(&udc->lock);
                        usb_gadget_udc_reset(&udc->gadget, udc->driver);
                        spin_lock(&udc->lock);
                }

                if (status & USBA_HIGH_SPEED)
                        udc->gadget.speed = USB_SPEED_HIGH;
                else
                        udc->gadget.speed = USB_SPEED_FULL;
                DBG(DBG_BUS, "%s bus reset detected\n",
                    usb_speed_string(udc->gadget.speed));

                ep0 = &udc->usba_ep[0];
                ep0->ep.desc = &usba_ep0_desc;
                ep0->state = WAIT_FOR_SETUP;
                usba_ep_writel(ep0, CFG,
                                (USBA_BF(EPT_SIZE, EP0_EPT_SIZE)
                                | USBA_BF(EPT_TYPE, USBA_EPT_TYPE_CONTROL)
                                | USBA_BF(BK_NUMBER, USBA_BK_NUMBER_ONE)));
                usba_ep_writel(ep0, CTL_ENB,
                                USBA_EPT_ENABLE | USBA_RX_SETUP);

                /* If we get reset while suspended... */
                udc->suspended = false;
                usba_int_enb_clear(udc, USBA_WAKE_UP);

                usba_int_enb_set(udc, USBA_BF(EPT_INT, 1) |
                                      USBA_DET_SUSPEND | USBA_END_OF_RESUME);

                /*
                 * Unclear why we hit this irregularly, e.g. in usbtest,
                 * but it's clearly harmless...
                 */
                if (!(usba_ep_readl(ep0, CFG) & USBA_EPT_MAPPED))
                        dev_err(&udc->pdev->dev,
                                "ODD: EP0 configuration is invalid!\n");

                /* Preallocate other endpoints */
                n = fifo_mode ? udc->num_ep : udc->configured_ep;
                for (i = 1; i < n; i++) {
                        ep = &udc->usba_ep[i];
                        usba_ep_writel(ep, CFG, ep->ept_cfg);
                        if (!(usba_ep_readl(ep, CFG) & USBA_EPT_MAPPED))
                                dev_err(&udc->pdev->dev,
                                        "ODD: EP%d configuration is invalid!\n", i);
                }
        }

        spin_unlock(&udc->lock);

        return IRQ_HANDLED;
}

static int start_clock(struct usba_udc *udc)
{
        int ret;

        if (udc->clocked)
                return 0;

        pm_stay_awake(&udc->pdev->dev);

        ret = clk_prepare_enable(udc->pclk);
        if (ret)
                return ret;
        ret = clk_prepare_enable(udc->hclk);
        if (ret) {
                clk_disable_unprepare(udc->pclk);
                return ret;
        }

        udc->clocked = true;
        return 0;
}

static void stop_clock(struct usba_udc *udc)
{
        if (!udc->clocked)
                return;

        clk_disable_unprepare(udc->hclk);
        clk_disable_unprepare(udc->pclk);

        udc->clocked = false;

        pm_relax(&udc->pdev->dev);
}

static int usba_start(struct usba_udc *udc)
{
        unsigned long flags;
        int ret;

        ret = start_clock(udc);
        if (ret)
                return ret;

        if (udc->suspended)
                return 0;

        spin_lock_irqsave(&udc->lock, flags);
        toggle_bias(udc, 1);
        usba_writel(udc, CTRL, USBA_ENABLE_MASK);
        /* Clear all requested and pending interrupts... */
        usba_writel(udc, INT_ENB, 0);
        udc->int_enb_cache = 0;
        usba_writel(udc, INT_CLR,
                USBA_END_OF_RESET|USBA_END_OF_RESUME
                |USBA_DET_SUSPEND|USBA_WAKE_UP);
        /* ...and enable just 'reset' IRQ to get us started */
        usba_int_enb_set(udc, USBA_END_OF_RESET);
        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
}

static void usba_stop(struct usba_udc *udc)
{
        unsigned long flags;

        if (udc->suspended)
                return;

        spin_lock_irqsave(&udc->lock, flags);
        udc->gadget.speed = USB_SPEED_UNKNOWN;
        reset_all_endpoints(udc);

        /* This will also disable the DP pullup */
        toggle_bias(udc, 0);
        usba_writel(udc, CTRL, USBA_DISABLE_MASK);
        spin_unlock_irqrestore(&udc->lock, flags);

        stop_clock(udc);
}

static irqreturn_t usba_vbus_irq_thread(int irq, void *devid)
{
        struct usba_udc *udc = devid;
        int vbus;

        /* debounce */
        udelay(10);

        mutex_lock(&udc->vbus_mutex);

        vbus = vbus_is_present(udc);
        if (vbus != udc->vbus_prev) {
                if (vbus) {
                        usba_start(udc);
                } else {
                        udc->suspended = false;
                        if (udc->driver->disconnect)
                                udc->driver->disconnect(&udc->gadget);

                        usba_stop(udc);
                }
                udc->vbus_prev = vbus;
        }

        mutex_unlock(&udc->vbus_mutex);
        return IRQ_HANDLED;
}

static int atmel_usba_pullup(struct usb_gadget *gadget, int is_on)
{
        struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget);
        unsigned long flags;
        u32 ctrl;

        spin_lock_irqsave(&udc->lock, flags);
        ctrl = usba_readl(udc, CTRL);
        if (is_on)
                ctrl &= ~USBA_DETACH;
        else
                ctrl |= USBA_DETACH;
        usba_writel(udc, CTRL, ctrl);
        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
}

static int atmel_usba_start(struct usb_gadget *gadget,
                struct usb_gadget_driver *driver)
{
        int ret;
        struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget);
        unsigned long flags;

        spin_lock_irqsave(&udc->lock, flags);
        udc->devstatus = 1 << USB_DEVICE_SELF_POWERED;
        udc->driver = driver;
        spin_unlock_irqrestore(&udc->lock, flags);

        mutex_lock(&udc->vbus_mutex);

        if (udc->vbus_pin)
                enable_irq(gpiod_to_irq(udc->vbus_pin));

        /* If Vbus is present, enable the controller and wait for reset */
        udc->vbus_prev = vbus_is_present(udc);
        if (udc->vbus_prev) {
                ret = usba_start(udc);

                if (ret)
                        goto err;
        }

        mutex_unlock(&udc->vbus_mutex);
        return 0;

err:
        if (udc->vbus_pin)
                disable_irq(gpiod_to_irq(udc->vbus_pin));

        mutex_unlock(&udc->vbus_mutex);

        spin_lock_irqsave(&udc->lock, flags);
        udc->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
        udc->driver = NULL;
        spin_unlock_irqrestore(&udc->lock, flags);
        return ret;
}

static int atmel_usba_stop(struct usb_gadget *gadget)
{
        struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget);

        if (udc->vbus_pin)
                disable_irq(gpiod_to_irq(udc->vbus_pin));

        if (fifo_mode == 0)
                udc->configured_ep = 1;

        udc->suspended = false;
        usba_stop(udc);

        udc->driver = NULL;

        return 0;
}

static void at91sam9rl_toggle_bias(struct usba_udc *udc, int is_on)
{
        regmap_update_bits(udc->pmc, AT91_CKGR_UCKR, AT91_PMC_BIASEN,
                           is_on ? AT91_PMC_BIASEN : 0);
}

static void at91sam9g45_pulse_bias(struct usba_udc *udc)
{
        regmap_update_bits(udc->pmc, AT91_CKGR_UCKR, AT91_PMC_BIASEN, 0);
        regmap_update_bits(udc->pmc, AT91_CKGR_UCKR, AT91_PMC_BIASEN,
                           AT91_PMC_BIASEN);
}

static const struct usba_udc_errata at91sam9rl_errata = {
        .toggle_bias = at91sam9rl_toggle_bias,
};

static const struct usba_udc_errata at91sam9g45_errata = {
        .pulse_bias = at91sam9g45_pulse_bias,
};

static const struct usba_ep_config ep_config_sam9[] __initconst = {
        { .nr_banks = 1 },                              /* ep 0 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 1 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 2 */
        { .nr_banks = 3, .can_dma = 1 },                /* ep 3 */
        { .nr_banks = 3, .can_dma = 1 },                /* ep 4 */
        { .nr_banks = 3, .can_dma = 1, .can_isoc = 1 }, /* ep 5 */
        { .nr_banks = 3, .can_dma = 1, .can_isoc = 1 }, /* ep 6 */
};

static const struct usba_ep_config ep_config_sama5[] __initconst = {
        { .nr_banks = 1 },                              /* ep 0 */
        { .nr_banks = 3, .can_dma = 1, .can_isoc = 1 }, /* ep 1 */
        { .nr_banks = 3, .can_dma = 1, .can_isoc = 1 }, /* ep 2 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 3 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 4 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 5 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 6 */
        { .nr_banks = 2, .can_dma = 1, .can_isoc = 1 }, /* ep 7 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 8 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 9 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 10 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 11 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 12 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 13 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 14 */
        { .nr_banks = 2, .can_isoc = 1 },               /* ep 15 */
};

static const struct usba_udc_config udc_at91sam9rl_cfg = {
        .errata = &at91sam9rl_errata,
        .config = ep_config_sam9,
        .num_ep = ARRAY_SIZE(ep_config_sam9),
};

static const struct usba_udc_config udc_at91sam9g45_cfg = {
        .errata = &at91sam9g45_errata,
        .config = ep_config_sam9,
        .num_ep = ARRAY_SIZE(ep_config_sam9),
};

static const struct usba_udc_config udc_sama5d3_cfg = {
        .config = ep_config_sama5,
        .num_ep = ARRAY_SIZE(ep_config_sama5),
};

static const struct of_device_id atmel_udc_dt_ids[] = {
        { .compatible = "atmel,at91sam9rl-udc", .data = &udc_at91sam9rl_cfg },
        { .compatible = "atmel,at91sam9g45-udc", .data = &udc_at91sam9g45_cfg },
        { .compatible = "atmel,sama5d3-udc", .data = &udc_sama5d3_cfg },
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, atmel_udc_dt_ids);

static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
                                                    struct usba_udc *udc)
{
        struct device_node *np = pdev->dev.of_node;
        const struct of_device_id *match;
        int i, ret;
        struct usba_ep *eps, *ep;
        const struct usba_udc_config *udc_config;

        match = of_match_node(atmel_udc_dt_ids, np);
        if (!match)
                return ERR_PTR(-EINVAL);

        udc_config = match->data;
        udc->errata = udc_config->errata;
        udc->pmc = syscon_regmap_lookup_by_compatible("atmel,at91sam9g45-pmc");
        if (IS_ERR(udc->pmc))
                udc->pmc = syscon_regmap_lookup_by_compatible("atmel,at91sam9rl-pmc");
        if (IS_ERR(udc->pmc))
                udc->pmc = syscon_regmap_lookup_by_compatible("atmel,at91sam9x5-pmc");
        if (udc->errata && IS_ERR(udc->pmc))
                return ERR_CAST(udc->pmc);

        udc->num_ep = 0;

        udc->vbus_pin = devm_gpiod_get_optional(&pdev->dev, "atmel,vbus",
                                                GPIOD_IN);

        if (fifo_mode == 0) {
                udc->num_ep = udc_config->num_ep;
                udc->configured_ep = 1;
        } else {
                udc->num_ep = usba_config_fifo_table(udc);
        }

        eps = devm_kcalloc(&pdev->dev, udc->num_ep, sizeof(struct usba_ep),
                           GFP_KERNEL);
        if (!eps)
                return ERR_PTR(-ENOMEM);

        udc->gadget.ep0 = &eps[0].ep;

        INIT_LIST_HEAD(&eps[0].ep.ep_list);

        i = 0;
        while (i < udc->num_ep) {
                const struct usba_ep_config *ep_cfg = &udc_config->config[i];

                ep = &eps[i];

                ep->index = fifo_mode ? udc->fifo_cfg[i].hw_ep_num : i;

                /* Only the first EP is 64 bytes */
                if (ep->index == 0)
                        ep->fifo_size = 64;
                else
                        ep->fifo_size = 1024;

                if (fifo_mode) {
                        if (ep->fifo_size < udc->fifo_cfg[i].fifo_size)
                                dev_warn(&pdev->dev,
                                         "Using default max fifo-size value\n");
                        else
                                ep->fifo_size = udc->fifo_cfg[i].fifo_size;
                }

                ep->nr_banks = ep_cfg->nr_banks;
                if (fifo_mode) {
                        if (ep->nr_banks < udc->fifo_cfg[i].nr_banks)
                                dev_warn(&pdev->dev,
                                         "Using default max nb-banks value\n");
                        else
                                ep->nr_banks = udc->fifo_cfg[i].nr_banks;
                }

                ep->can_dma = ep_cfg->can_dma;
                ep->can_isoc = ep_cfg->can_isoc;

                sprintf(ep->name, "ep%d", ep->index);
                ep->ep.name = ep->name;

                ep->ep_regs = udc->regs + USBA_EPT_BASE(i);
                ep->dma_regs = udc->regs + USBA_DMA_BASE(i);
                ep->fifo = udc->fifo + USBA_FIFO_BASE(i);
                ep->ep.ops = &usba_ep_ops;
                usb_ep_set_maxpacket_limit(&ep->ep, ep->fifo_size);
                ep->udc = udc;
                INIT_LIST_HEAD(&ep->queue);

                if (ep->index == 0) {
                        ep->ep.caps.type_control = true;
                } else {
                        ep->ep.caps.type_iso = ep->can_isoc;
                        ep->ep.caps.type_bulk = true;
                        ep->ep.caps.type_int = true;
                }

                ep->ep.caps.dir_in = true;
                ep->ep.caps.dir_out = true;

                if (fifo_mode != 0) {
                        /*
                         * Generate ept_cfg based on FIFO size and
                         * banks number
                         */
                        if (ep->fifo_size  <= 8)
                                ep->ept_cfg = USBA_BF(EPT_SIZE, USBA_EPT_SIZE_8);
                        else
                                /* LSB is bit 1, not 0 */
                                ep->ept_cfg =
                                  USBA_BF(EPT_SIZE, fls(ep->fifo_size - 1) - 3);

                        ep->ept_cfg |= USBA_BF(BK_NUMBER, ep->nr_banks);
                }

                if (i)
                        list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);

                i++;
        }

        if (i == 0) {
                dev_err(&pdev->dev, "of_probe: no endpoint specified\n");
                ret = -EINVAL;
                goto err;
        }

        return eps;
err:
        return ERR_PTR(ret);
}

static int usba_udc_probe(struct platform_device *pdev)
{
        struct resource *res;
        struct clk *pclk, *hclk;
        struct usba_udc *udc;
        int irq, ret, i;

        udc = devm_kzalloc(&pdev->dev, sizeof(*udc), GFP_KERNEL);
        if (!udc)
                return -ENOMEM;

        udc->gadget = usba_gadget_template;
        INIT_LIST_HEAD(&udc->gadget.ep_list);

        res = platform_get_resource(pdev, IORESOURCE_MEM, CTRL_IOMEM_ID);
        udc->regs = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(udc->regs))
                return PTR_ERR(udc->regs);
        dev_info(&pdev->dev, "MMIO registers at %pR mapped at %p\n",
                 res, udc->regs);

        res = platform_get_resource(pdev, IORESOURCE_MEM, FIFO_IOMEM_ID);
        udc->fifo = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(udc->fifo))
                return PTR_ERR(udc->fifo);
        dev_info(&pdev->dev, "FIFO at %pR mapped at %p\n", res, udc->fifo);

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        pclk = devm_clk_get(&pdev->dev, "pclk");
        if (IS_ERR(pclk))
                return PTR_ERR(pclk);
        hclk = devm_clk_get(&pdev->dev, "hclk");
        if (IS_ERR(hclk))
                return PTR_ERR(hclk);

        spin_lock_init(&udc->lock);
        mutex_init(&udc->vbus_mutex);
        udc->pdev = pdev;
        udc->pclk = pclk;
        udc->hclk = hclk;

        platform_set_drvdata(pdev, udc);

        /* Make sure we start from a clean slate */
        ret = clk_prepare_enable(pclk);
        if (ret) {
                dev_err(&pdev->dev, "Unable to enable pclk, aborting.\n");
                return ret;
        }

        usba_writel(udc, CTRL, USBA_DISABLE_MASK);
        clk_disable_unprepare(pclk);

        udc->usba_ep = atmel_udc_of_init(pdev, udc);

        toggle_bias(udc, 0);

        if (IS_ERR(udc->usba_ep))
                return PTR_ERR(udc->usba_ep);

        ret = devm_request_irq(&pdev->dev, irq, usba_udc_irq, 0,
                                "atmel_usba_udc", udc);
        if (ret) {
                dev_err(&pdev->dev, "Cannot request irq %d (error %d)\n",
                        irq, ret);
                return ret;
        }
        udc->irq = irq;

        if (udc->vbus_pin) {
                irq_set_status_flags(gpiod_to_irq(udc->vbus_pin), IRQ_NOAUTOEN);
                ret = devm_request_threaded_irq(&pdev->dev,
                                gpiod_to_irq(udc->vbus_pin), NULL,
                                usba_vbus_irq_thread, USBA_VBUS_IRQFLAGS,
                                "atmel_usba_udc", udc);
                if (ret) {
                        udc->vbus_pin = NULL;
                        dev_warn(&udc->pdev->dev,
                                 "failed to request vbus irq; "
                                 "assuming always on\n");
                }
        }

        ret = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
        if (ret)
                return ret;
        device_init_wakeup(&pdev->dev, 1);

        usba_init_debugfs(udc);
        for (i = 1; i < udc->num_ep; i++)
                usba_ep_init_debugfs(udc, &udc->usba_ep[i]);

        return 0;
}

static int usba_udc_remove(struct platform_device *pdev)
{
        struct usba_udc *udc;
        int i;

        udc = platform_get_drvdata(pdev);

        device_init_wakeup(&pdev->dev, 0);
        usb_del_gadget_udc(&udc->gadget);

        for (i = 1; i < udc->num_ep; i++)
                usba_ep_cleanup_debugfs(&udc->usba_ep[i]);
        usba_cleanup_debugfs(udc);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int usba_udc_suspend(struct device *dev)
{
        struct usba_udc *udc = dev_get_drvdata(dev);

        /* Not started */
        if (!udc->driver)
                return 0;

        mutex_lock(&udc->vbus_mutex);

        if (!device_may_wakeup(dev)) {
                udc->suspended = false;
                usba_stop(udc);
                goto out;
        }

        /*
         * Device may wake up. We stay clocked if we failed
         * to request vbus irq, assuming always on.
         */
        if (udc->vbus_pin) {
                /* FIXME: right to stop here...??? */
                usba_stop(udc);
                enable_irq_wake(gpiod_to_irq(udc->vbus_pin));
        }

        enable_irq_wake(udc->irq);

out:
        mutex_unlock(&udc->vbus_mutex);
        return 0;
}

static int usba_udc_resume(struct device *dev)
{
        struct usba_udc *udc = dev_get_drvdata(dev);

        /* Not started */
        if (!udc->driver)
                return 0;

        if (device_may_wakeup(dev)) {
                if (udc->vbus_pin)
                        disable_irq_wake(gpiod_to_irq(udc->vbus_pin));

                disable_irq_wake(udc->irq);
        }

        /* If Vbus is present, enable the controller and wait for reset */
        mutex_lock(&udc->vbus_mutex);
        udc->vbus_prev = vbus_is_present(udc);
        if (udc->vbus_prev)
                usba_start(udc);
        mutex_unlock(&udc->vbus_mutex);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(usba_udc_pm_ops, usba_udc_suspend, usba_udc_resume);

static struct platform_driver udc_driver = {
        .remove         = usba_udc_remove,
        .driver         = {
                .name           = "atmel_usba_udc",
                .pm             = &usba_udc_pm_ops,
                .of_match_table = atmel_udc_dt_ids,
        },
};

module_platform_driver_probe(udc_driver, usba_udc_probe);

MODULE_DESCRIPTION("Atmel USBA UDC driver");
MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:atmel_usba_udc");