// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for PLX NET2272 USB device controller
 *
 * Copyright (C) 2005-2006 PLX Technology, Inc.
 * Copyright (C) 2006-2011 Analog Devices, Inc.
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/prefetch.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <asm/byteorder.h>
#include <asm/unaligned.h>

#include "net2272.h"

#define DRIVER_DESC "PLX NET2272 USB Peripheral Controller"

static const char driver_name[] = "net2272";
static const char driver_vers[] = "2006 October 17/mainline";
static const char driver_desc[] = DRIVER_DESC;

static const char ep0name[] = "ep0";
static const char * const ep_name[] = {
        ep0name,
        "ep-a", "ep-b", "ep-c",
};

#ifdef CONFIG_USB_NET2272_DMA
/*
 * use_dma: the NET2272 can use an external DMA controller.
 * Note that since there is no generic DMA api, some functions,
 * notably request_dma, start_dma, and cancel_dma will need to be
 * modified for your platform's particular dma controller.
 *
 * If use_dma is disabled, pio will be used instead.
 */
static bool use_dma = false;
module_param(use_dma, bool, 0644);

/*
 * dma_ep: selects the endpoint for use with dma (1=ep-a, 2=ep-b)
 * The NET2272 can only use dma for a single endpoint at a time.
 * At some point this could be modified to allow either endpoint
 * to take control of dma as it becomes available.
 *
 * Note that DMA should not be used on OUT endpoints unless it can
 * be guaranteed that no short packets will arrive on an IN endpoint
 * while the DMA operation is pending.  Otherwise the OUT DMA will
 * terminate prematurely (See NET2272 Errata 630-0213-0101)
 */
static ushort dma_ep = 1;
module_param(dma_ep, ushort, 0644);

/*
 * dma_mode: net2272 dma mode setting (see LOCCTL1 definiton):
 *      mode 0 == Slow DREQ mode
 *      mode 1 == Fast DREQ mode
 *      mode 2 == Burst mode
 */
static ushort dma_mode = 2;
module_param(dma_mode, ushort, 0644);
#else
#define use_dma 0
#define dma_ep 1
#define dma_mode 2
#endif

/*
 * fifo_mode: net2272 buffer configuration:
 *      mode 0 == ep-{a,b,c} 512db each
 *      mode 1 == ep-a 1k, ep-{b,c} 512db
 *      mode 2 == ep-a 1k, ep-b 1k, ep-c 512db
 *      mode 3 == ep-a 1k, ep-b disabled, ep-c 512db
 */
static ushort fifo_mode = 0;
module_param(fifo_mode, ushort, 0644);

/*
 * enable_suspend: When enabled, the driver will respond to
 * USB suspend requests by powering down the NET2272.  Otherwise,
 * USB suspend requests will be ignored.  This is acceptible for
 * self-powered devices.  For bus powered devices set this to 1.
 */
static ushort enable_suspend = 0;
module_param(enable_suspend, ushort, 0644);

static void assert_out_naking(struct net2272_ep *ep, const char *where)
{
        u8 tmp;

#ifndef DEBUG
        return;
#endif

        tmp = net2272_ep_read(ep, EP_STAT0);
        if ((tmp & (1 << NAK_OUT_PACKETS)) == 0) {
                dev_dbg(ep->dev->dev, "%s %s %02x !NAK\n",
                        ep->ep.name, where, tmp);
                net2272_ep_write(ep, EP_RSPSET, 1 << ALT_NAK_OUT_PACKETS);
        }
}
#define ASSERT_OUT_NAKING(ep) assert_out_naking(ep, __func__)

static void stop_out_naking(struct net2272_ep *ep)
{
        u8 tmp = net2272_ep_read(ep, EP_STAT0);

        if ((tmp & (1 << NAK_OUT_PACKETS)) != 0)
                net2272_ep_write(ep, EP_RSPCLR, 1 << ALT_NAK_OUT_PACKETS);
}

#define PIPEDIR(bAddress) (usb_pipein(bAddress) ? "in" : "out")

static char *type_string(u8 bmAttributes)
{
        switch ((bmAttributes) & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_BULK: return "bulk";
        case USB_ENDPOINT_XFER_ISOC: return "iso";
        case USB_ENDPOINT_XFER_INT:  return "intr";
        default:                     return "control";
        }
}

static char *buf_state_string(unsigned state)
{
        switch (state) {
        case BUFF_FREE:  return "free";
        case BUFF_VALID: return "valid";
        case BUFF_LCL:   return "local";
        case BUFF_USB:   return "usb";
        default:         return "unknown";
        }
}

static char *dma_mode_string(void)
{
        if (!use_dma)
                return "PIO";
        switch (dma_mode) {
        case 0:  return "SLOW DREQ";
        case 1:  return "FAST DREQ";
        case 2:  return "BURST";
        default: return "invalid";
        }
}

static void net2272_dequeue_all(struct net2272_ep *);
static int net2272_kick_dma(struct net2272_ep *, struct net2272_request *);
static int net2272_fifo_status(struct usb_ep *);

static const struct usb_ep_ops net2272_ep_ops;

/*---------------------------------------------------------------------------*/

static int
net2272_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
        struct net2272 *dev;
        struct net2272_ep *ep;
        u32 max;
        u8 tmp;
        unsigned long flags;

        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || !desc || ep->desc || _ep->name == ep0name
                        || desc->bDescriptorType != USB_DT_ENDPOINT)
                return -EINVAL;
        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        max = usb_endpoint_maxp(desc);

        spin_lock_irqsave(&dev->lock, flags);
        _ep->maxpacket = max;
        ep->desc = desc;

        /* net2272_ep_reset() has already been called */
        ep->stopped = 0;
        ep->wedged = 0;

        /* set speed-dependent max packet */
        net2272_ep_write(ep, EP_MAXPKT0, max & 0xff);
        net2272_ep_write(ep, EP_MAXPKT1, (max & 0xff00) >> 8);

        /* set type, direction, address; reset fifo counters */
        net2272_ep_write(ep, EP_STAT1, 1 << BUFFER_FLUSH);
        tmp = usb_endpoint_type(desc);
        if (usb_endpoint_xfer_bulk(desc)) {
                /* catch some particularly blatant driver bugs */
                if ((dev->gadget.speed == USB_SPEED_HIGH && max != 512) ||
                    (dev->gadget.speed == USB_SPEED_FULL && max > 64)) {
                        spin_unlock_irqrestore(&dev->lock, flags);
                        return -ERANGE;
                }
        }
        ep->is_iso = usb_endpoint_xfer_isoc(desc) ? 1 : 0;
        tmp <<= ENDPOINT_TYPE;
        tmp |= ((desc->bEndpointAddress & 0x0f) << ENDPOINT_NUMBER);
        tmp |= usb_endpoint_dir_in(desc) << ENDPOINT_DIRECTION;
        tmp |= (1 << ENDPOINT_ENABLE);

        /* for OUT transfers, block the rx fifo until a read is posted */
        ep->is_in = usb_endpoint_dir_in(desc);
        if (!ep->is_in)
                net2272_ep_write(ep, EP_RSPSET, 1 << ALT_NAK_OUT_PACKETS);

        net2272_ep_write(ep, EP_CFG, tmp);

        /* enable irqs */
        tmp = (1 << ep->num) | net2272_read(dev, IRQENB0);
        net2272_write(dev, IRQENB0, tmp);

        tmp = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
                | (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
                | net2272_ep_read(ep, EP_IRQENB);
        net2272_ep_write(ep, EP_IRQENB, tmp);

        tmp = desc->bEndpointAddress;
        dev_dbg(dev->dev, "enabled %s (ep%d%s-%s) max %04x cfg %02x\n",
                _ep->name, tmp & 0x0f, PIPEDIR(tmp),
                type_string(desc->bmAttributes), max,
                net2272_ep_read(ep, EP_CFG));

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

static void net2272_ep_reset(struct net2272_ep *ep)
{
        u8 tmp;

        ep->desc = NULL;
        INIT_LIST_HEAD(&ep->queue);

        usb_ep_set_maxpacket_limit(&ep->ep, ~0);
        ep->ep.ops = &net2272_ep_ops;

        /* disable irqs, endpoint */
        net2272_ep_write(ep, EP_IRQENB, 0);

        /* init to our chosen defaults, notably so that we NAK OUT
         * packets until the driver queues a read.
         */
        tmp = (1 << NAK_OUT_PACKETS_MODE) | (1 << ALT_NAK_OUT_PACKETS);
        net2272_ep_write(ep, EP_RSPSET, tmp);

        tmp = (1 << INTERRUPT_MODE) | (1 << HIDE_STATUS_PHASE);
        if (ep->num != 0)
                tmp |= (1 << ENDPOINT_TOGGLE) | (1 << ENDPOINT_HALT);

        net2272_ep_write(ep, EP_RSPCLR, tmp);

        /* scrub most status bits, and flush any fifo state */
        net2272_ep_write(ep, EP_STAT0,
                          (1 << DATA_IN_TOKEN_INTERRUPT)
                        | (1 << DATA_OUT_TOKEN_INTERRUPT)
                        | (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
                        | (1 << DATA_PACKET_RECEIVED_INTERRUPT)
                        | (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT));

        net2272_ep_write(ep, EP_STAT1,
                            (1 << TIMEOUT)
                          | (1 << USB_OUT_ACK_SENT)
                          | (1 << USB_OUT_NAK_SENT)
                          | (1 << USB_IN_ACK_RCVD)
                          | (1 << USB_IN_NAK_SENT)
                          | (1 << USB_STALL_SENT)
                          | (1 << LOCAL_OUT_ZLP)
                          | (1 << BUFFER_FLUSH));

        /* fifo size is handled seperately */
}

static int net2272_disable(struct usb_ep *_ep)
{
        struct net2272_ep *ep;
        unsigned long flags;

        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || !ep->desc || _ep->name == ep0name)
                return -EINVAL;

        spin_lock_irqsave(&ep->dev->lock, flags);
        net2272_dequeue_all(ep);
        net2272_ep_reset(ep);

        dev_vdbg(ep->dev->dev, "disabled %s\n", _ep->name);

        spin_unlock_irqrestore(&ep->dev->lock, flags);
        return 0;
}

/*---------------------------------------------------------------------------*/

static struct usb_request *
net2272_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct net2272_request *req;

        if (!_ep)
                return NULL;

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

        INIT_LIST_HEAD(&req->queue);

        return &req->req;
}

static void
net2272_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
        struct net2272_request *req;

        if (!_ep || !_req)
                return;

        req = container_of(_req, struct net2272_request, req);
        WARN_ON(!list_empty(&req->queue));
        kfree(req);
}

static void
net2272_done(struct net2272_ep *ep, struct net2272_request *req, int status)
{
        struct net2272 *dev;
        unsigned stopped = ep->stopped;

        if (ep->num == 0) {
                if (ep->dev->protocol_stall) {
                        ep->stopped = 1;
                        set_halt(ep);
                }
                allow_status(ep);
        }

        list_del_init(&req->queue);

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

        dev = ep->dev;
        if (use_dma && ep->dma)
                usb_gadget_unmap_request(&dev->gadget, &req->req,
                                ep->is_in);

        if (status && status != -ESHUTDOWN)
                dev_vdbg(dev->dev, "complete %s req %p stat %d len %u/%u buf %p\n",
                        ep->ep.name, &req->req, status,
                        req->req.actual, req->req.length, req->req.buf);

        /* don't modify queue heads during completion callback */
        ep->stopped = 1;
        spin_unlock(&dev->lock);
        usb_gadget_giveback_request(&ep->ep, &req->req);
        spin_lock(&dev->lock);
        ep->stopped = stopped;
}

static int
net2272_write_packet(struct net2272_ep *ep, u8 *buf,
        struct net2272_request *req, unsigned max)
{
        u16 __iomem *ep_data = net2272_reg_addr(ep->dev, EP_DATA);
        u16 *bufp;
        unsigned length, count;
        u8 tmp;

        length = min(req->req.length - req->req.actual, max);
        req->req.actual += length;

        dev_vdbg(ep->dev->dev, "write packet %s req %p max %u len %u avail %u\n",
                ep->ep.name, req, max, length,
                (net2272_ep_read(ep, EP_AVAIL1) << 8) | net2272_ep_read(ep, EP_AVAIL0));

        count = length;
        bufp = (u16 *)buf;

        while (likely(count >= 2)) {
                /* no byte-swap required; chip endian set during init */
                writew(*bufp++, ep_data);
                count -= 2;
        }
        buf = (u8 *)bufp;

        /* write final byte by placing the NET2272 into 8-bit mode */
        if (unlikely(count)) {
                tmp = net2272_read(ep->dev, LOCCTL);
                net2272_write(ep->dev, LOCCTL, tmp & ~(1 << DATA_WIDTH));
                writeb(*buf, ep_data);
                net2272_write(ep->dev, LOCCTL, tmp);
        }
        return length;
}

/* returns: 0: still running, 1: completed, negative: errno */
static int
net2272_write_fifo(struct net2272_ep *ep, struct net2272_request *req)
{
        u8 *buf;
        unsigned count, max;
        int status;

        dev_vdbg(ep->dev->dev, "write_fifo %s actual %d len %d\n",
                ep->ep.name, req->req.actual, req->req.length);

        /*
         * Keep loading the endpoint until the final packet is loaded,
         * or the endpoint buffer is full.
         */
 top:
        /*
         * Clear interrupt status
         *  - Packet Transmitted interrupt will become set again when the
         *    host successfully takes another packet
         */
        net2272_ep_write(ep, EP_STAT0, (1 << DATA_PACKET_TRANSMITTED_INTERRUPT));
        while (!(net2272_ep_read(ep, EP_STAT0) & (1 << BUFFER_FULL))) {
                buf = req->req.buf + req->req.actual;
                prefetch(buf);

                /* force pagesel */
                net2272_ep_read(ep, EP_STAT0);

                max = (net2272_ep_read(ep, EP_AVAIL1) << 8) |
                        (net2272_ep_read(ep, EP_AVAIL0));

                if (max < ep->ep.maxpacket)
                        max = (net2272_ep_read(ep, EP_AVAIL1) << 8)
                                | (net2272_ep_read(ep, EP_AVAIL0));

                count = net2272_write_packet(ep, buf, req, max);
                /* see if we are done */
                if (req->req.length == req->req.actual) {
                        /* validate short or zlp packet */
                        if (count < ep->ep.maxpacket)
                                set_fifo_bytecount(ep, 0);
                        net2272_done(ep, req, 0);

                        if (!list_empty(&ep->queue)) {
                                req = list_entry(ep->queue.next,
                                                struct net2272_request,
                                                queue);
                                status = net2272_kick_dma(ep, req);

                                if (status < 0)
                                        if ((net2272_ep_read(ep, EP_STAT0)
                                                        & (1 << BUFFER_EMPTY)))
                                                goto top;
                        }
                        return 1;
                }
                net2272_ep_write(ep, EP_STAT0, (1 << DATA_PACKET_TRANSMITTED_INTERRUPT));
        }
        return 0;
}

static void
net2272_out_flush(struct net2272_ep *ep)
{
        ASSERT_OUT_NAKING(ep);

        net2272_ep_write(ep, EP_STAT0, (1 << DATA_OUT_TOKEN_INTERRUPT)
                        | (1 << DATA_PACKET_RECEIVED_INTERRUPT));
        net2272_ep_write(ep, EP_STAT1, 1 << BUFFER_FLUSH);
}

static int
net2272_read_packet(struct net2272_ep *ep, u8 *buf,
        struct net2272_request *req, unsigned avail)
{
        u16 __iomem *ep_data = net2272_reg_addr(ep->dev, EP_DATA);
        unsigned is_short;
        u16 *bufp;

        req->req.actual += avail;

        dev_vdbg(ep->dev->dev, "read packet %s req %p len %u avail %u\n",
                ep->ep.name, req, avail,
                (net2272_ep_read(ep, EP_AVAIL1) << 8) | net2272_ep_read(ep, EP_AVAIL0));

        is_short = (avail < ep->ep.maxpacket);

        if (unlikely(avail == 0)) {
                /* remove any zlp from the buffer */
                (void)readw(ep_data);
                return is_short;
        }

        /* Ensure we get the final byte */
        if (unlikely(avail % 2))
                avail++;
        bufp = (u16 *)buf;

        do {
                *bufp++ = readw(ep_data);
                avail -= 2;
        } while (avail);

        /*
         * To avoid false endpoint available race condition must read
         * ep stat0 twice in the case of a short transfer
         */
        if (net2272_ep_read(ep, EP_STAT0) & (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT))
                net2272_ep_read(ep, EP_STAT0);

        return is_short;
}

static int
net2272_read_fifo(struct net2272_ep *ep, struct net2272_request *req)
{
        u8 *buf;
        unsigned is_short;
        int count;
        int tmp;
        int cleanup = 0;
        int status = -1;

        dev_vdbg(ep->dev->dev, "read_fifo %s actual %d len %d\n",
                ep->ep.name, req->req.actual, req->req.length);

 top:
        do {
                buf = req->req.buf + req->req.actual;
                prefetchw(buf);

                count = (net2272_ep_read(ep, EP_AVAIL1) << 8)
                        | net2272_ep_read(ep, EP_AVAIL0);

                net2272_ep_write(ep, EP_STAT0,
                        (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT) |
                        (1 << DATA_PACKET_RECEIVED_INTERRUPT));

                tmp = req->req.length - req->req.actual;

                if (count > tmp) {
                        if ((tmp % ep->ep.maxpacket) != 0) {
                                dev_err(ep->dev->dev,
                                        "%s out fifo %d bytes, expected %d\n",
                                        ep->ep.name, count, tmp);
                                cleanup = 1;
                        }
                        count = (tmp > 0) ? tmp : 0;
                }

                is_short = net2272_read_packet(ep, buf, req, count);

                /* completion */
                if (unlikely(cleanup || is_short ||
                                req->req.actual == req->req.length)) {

                        if (cleanup) {
                                net2272_out_flush(ep);
                                net2272_done(ep, req, -EOVERFLOW);
                        } else
                                net2272_done(ep, req, 0);

                        /* re-initialize endpoint transfer registers
                         * otherwise they may result in erroneous pre-validation
                         * for subsequent control reads
                         */
                        if (unlikely(ep->num == 0)) {
                                net2272_ep_write(ep, EP_TRANSFER2, 0);
                                net2272_ep_write(ep, EP_TRANSFER1, 0);
                                net2272_ep_write(ep, EP_TRANSFER0, 0);
                        }

                        if (!list_empty(&ep->queue)) {
                                req = list_entry(ep->queue.next,
                                        struct net2272_request, queue);
                                status = net2272_kick_dma(ep, req);
                                if ((status < 0) &&
                                    !(net2272_ep_read(ep, EP_STAT0) & (1 << BUFFER_EMPTY)))
                                        goto top;
                        }
                        return 1;
                }
        } while (!(net2272_ep_read(ep, EP_STAT0) & (1 << BUFFER_EMPTY)));

        return 0;
}

static void
net2272_pio_advance(struct net2272_ep *ep)
{
        struct net2272_request *req;

        if (unlikely(list_empty(&ep->queue)))
                return;

        req = list_entry(ep->queue.next, struct net2272_request, queue);
        (ep->is_in ? net2272_write_fifo : net2272_read_fifo)(ep, req);
}

/* returns 0 on success, else negative errno */
static int
net2272_request_dma(struct net2272 *dev, unsigned ep, u32 buf,
        unsigned len, unsigned dir)
{
        dev_vdbg(dev->dev, "request_dma ep %d buf %08x len %d dir %d\n",
                ep, buf, len, dir);

        /* The NET2272 only supports a single dma channel */
        if (dev->dma_busy)
                return -EBUSY;
        /*
         * EP_TRANSFER (used to determine the number of bytes received
         * in an OUT transfer) is 24 bits wide; don't ask for more than that.
         */
        if ((dir == 1) && (len > 0x1000000))
                return -EINVAL;

        dev->dma_busy = 1;

        /* initialize platform's dma */
#ifdef CONFIG_USB_PCI
        /* NET2272 addr, buffer addr, length, etc. */
        switch (dev->dev_id) {
        case PCI_DEVICE_ID_RDK1:
                /* Setup PLX 9054 DMA mode */
                writel((1 << LOCAL_BUS_WIDTH) |
                        (1 << TA_READY_INPUT_ENABLE) |
                        (0 << LOCAL_BURST_ENABLE) |
                        (1 << DONE_INTERRUPT_ENABLE) |
                        (1 << LOCAL_ADDRESSING_MODE) |
                        (1 << DEMAND_MODE) |
                        (1 << DMA_EOT_ENABLE) |
                        (1 << FAST_SLOW_TERMINATE_MODE_SELECT) |
                        (1 << DMA_CHANNEL_INTERRUPT_SELECT),
                        dev->rdk1.plx9054_base_addr + DMAMODE0);

                writel(0x100000, dev->rdk1.plx9054_base_addr + DMALADR0);
                writel(buf, dev->rdk1.plx9054_base_addr + DMAPADR0);
                writel(len, dev->rdk1.plx9054_base_addr + DMASIZ0);
                writel((dir << DIRECTION_OF_TRANSFER) |
                        (1 << INTERRUPT_AFTER_TERMINAL_COUNT),
                        dev->rdk1.plx9054_base_addr + DMADPR0);
                writel((1 << LOCAL_DMA_CHANNEL_0_INTERRUPT_ENABLE) |
                        readl(dev->rdk1.plx9054_base_addr + INTCSR),
                        dev->rdk1.plx9054_base_addr + INTCSR);

                break;
        }
#endif

        net2272_write(dev, DMAREQ,
                (0 << DMA_BUFFER_VALID) |
                (1 << DMA_REQUEST_ENABLE) |
                (1 << DMA_CONTROL_DACK) |
                (dev->dma_eot_polarity << EOT_POLARITY) |
                (dev->dma_dack_polarity << DACK_POLARITY) |
                (dev->dma_dreq_polarity << DREQ_POLARITY) |
                ((ep >> 1) << DMA_ENDPOINT_SELECT));

        (void) net2272_read(dev, SCRATCH);

        return 0;
}

static void
net2272_start_dma(struct net2272 *dev)
{
        /* start platform's dma controller */
#ifdef CONFIG_USB_PCI
        switch (dev->dev_id) {
        case PCI_DEVICE_ID_RDK1:
                writeb((1 << CHANNEL_ENABLE) | (1 << CHANNEL_START),
                        dev->rdk1.plx9054_base_addr + DMACSR0);
                break;
        }
#endif
}

/* returns 0 on success, else negative errno */
static int
net2272_kick_dma(struct net2272_ep *ep, struct net2272_request *req)
{
        unsigned size;
        u8 tmp;

        if (!use_dma || (ep->num < 1) || (ep->num > 2) || !ep->dma)
                return -EINVAL;

        /* don't use dma for odd-length transfers
         * otherwise, we'd need to deal with the last byte with pio
         */
        if (req->req.length & 1)
                return -EINVAL;

        dev_vdbg(ep->dev->dev, "kick_dma %s req %p dma %08llx\n",
                ep->ep.name, req, (unsigned long long) req->req.dma);

        net2272_ep_write(ep, EP_RSPSET, 1 << ALT_NAK_OUT_PACKETS);

        /* The NET2272 can only use DMA on one endpoint at a time */
        if (ep->dev->dma_busy)
                return -EBUSY;

        /* Make sure we only DMA an even number of bytes (we'll use
         * pio to complete the transfer)
         */
        size = req->req.length;
        size &= ~1;

        /* device-to-host transfer */
        if (ep->is_in) {
                /* initialize platform's dma controller */
                if (net2272_request_dma(ep->dev, ep->num, req->req.dma, size, 0))
                        /* unable to obtain DMA channel; return error and use pio mode */
                        return -EBUSY;
                req->req.actual += size;

        /* host-to-device transfer */
        } else {
                tmp = net2272_ep_read(ep, EP_STAT0);

                /* initialize platform's dma controller */
                if (net2272_request_dma(ep->dev, ep->num, req->req.dma, size, 1))
                        /* unable to obtain DMA channel; return error and use pio mode */
                        return -EBUSY;

                if (!(tmp & (1 << BUFFER_EMPTY)))
                        ep->not_empty = 1;
                else
                        ep->not_empty = 0;


                /* allow the endpoint's buffer to fill */
                net2272_ep_write(ep, EP_RSPCLR, 1 << ALT_NAK_OUT_PACKETS);

                /* this transfer completed and data's already in the fifo
                 * return error so pio gets used.
                 */
                if (tmp & (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)) {

                        /* deassert dreq */
                        net2272_write(ep->dev, DMAREQ,
                                (0 << DMA_BUFFER_VALID) |
                                (0 << DMA_REQUEST_ENABLE) |
                                (1 << DMA_CONTROL_DACK) |
                                (ep->dev->dma_eot_polarity << EOT_POLARITY) |
                                (ep->dev->dma_dack_polarity << DACK_POLARITY) |
                                (ep->dev->dma_dreq_polarity << DREQ_POLARITY) |
                                ((ep->num >> 1) << DMA_ENDPOINT_SELECT));

                        return -EBUSY;
                }
        }

        /* Don't use per-packet interrupts: use dma interrupts only */
        net2272_ep_write(ep, EP_IRQENB, 0);

        net2272_start_dma(ep->dev);

        return 0;
}

static void net2272_cancel_dma(struct net2272 *dev)
{
#ifdef CONFIG_USB_PCI
        switch (dev->dev_id) {
        case PCI_DEVICE_ID_RDK1:
                writeb(0, dev->rdk1.plx9054_base_addr + DMACSR0);
                writeb(1 << CHANNEL_ABORT, dev->rdk1.plx9054_base_addr + DMACSR0);
                while (!(readb(dev->rdk1.plx9054_base_addr + DMACSR0) &
                         (1 << CHANNEL_DONE)))
                        continue;       /* wait for dma to stabalize */

                /* dma abort generates an interrupt */
                writeb(1 << CHANNEL_CLEAR_INTERRUPT,
                        dev->rdk1.plx9054_base_addr + DMACSR0);
                break;
        }
#endif

        dev->dma_busy = 0;
}

/*---------------------------------------------------------------------------*/

static int
net2272_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct net2272_request *req;
        struct net2272_ep *ep;
        struct net2272 *dev;
        unsigned long flags;
        int status = -1;
        u8 s;

        req = container_of(_req, struct net2272_request, req);
        if (!_req || !_req->complete || !_req->buf
                        || !list_empty(&req->queue))
                return -EINVAL;
        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0))
                return -EINVAL;
        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        /* set up dma mapping in case the caller didn't */
        if (use_dma && ep->dma) {
                status = usb_gadget_map_request(&dev->gadget, _req,
                                ep->is_in);
                if (status)
                        return status;
        }

        dev_vdbg(dev->dev, "%s queue req %p, len %d buf %p dma %08llx %s\n",
                _ep->name, _req, _req->length, _req->buf,
                (unsigned long long) _req->dma, _req->zero ? "zero" : "!zero");

        spin_lock_irqsave(&dev->lock, flags);

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

        /* kickstart this i/o queue? */
        if (list_empty(&ep->queue) && !ep->stopped) {
                /* maybe there's no control data, just status ack */
                if (ep->num == 0 && _req->length == 0) {
                        net2272_done(ep, req, 0);
                        dev_vdbg(dev->dev, "%s status ack\n", ep->ep.name);
                        goto done;
                }

                /* Return zlp, don't let it block subsequent packets */
                s = net2272_ep_read(ep, EP_STAT0);
                if (s & (1 << BUFFER_EMPTY)) {
                        /* Buffer is empty check for a blocking zlp, handle it */
                        if ((s & (1 << NAK_OUT_PACKETS)) &&
                            net2272_ep_read(ep, EP_STAT1) & (1 << LOCAL_OUT_ZLP)) {
                                dev_dbg(dev->dev, "WARNING: returning ZLP short packet termination!\n");
                                /*
                                 * Request is going to terminate with a short packet ...
                                 * hope the client is ready for it!
                                 */
                                status = net2272_read_fifo(ep, req);
                                /* clear short packet naking */
                                net2272_ep_write(ep, EP_STAT0, (1 << NAK_OUT_PACKETS));
                                goto done;
                        }
                }

                /* try dma first */
                status = net2272_kick_dma(ep, req);

                if (status < 0) {
                        /* dma failed (most likely in use by another endpoint)
                         * fallback to pio
                         */
                        status = 0;

                        if (ep->is_in)
                                status = net2272_write_fifo(ep, req);
                        else {
                                s = net2272_ep_read(ep, EP_STAT0);
                                if ((s & (1 << BUFFER_EMPTY)) == 0)
                                        status = net2272_read_fifo(ep, req);
                        }

                        if (unlikely(status != 0)) {
                                if (status > 0)
                                        status = 0;
                                req = NULL;
                        }
                }
        }
        if (likely(req))
                list_add_tail(&req->queue, &ep->queue);

        if (likely(!list_empty(&ep->queue)))
                net2272_ep_write(ep, EP_RSPCLR, 1 << ALT_NAK_OUT_PACKETS);
 done:
        spin_unlock_irqrestore(&dev->lock, flags);

        return 0;
}

/* dequeue ALL requests */
static void
net2272_dequeue_all(struct net2272_ep *ep)
{
        struct net2272_request *req;

        /* called with spinlock held */
        ep->stopped = 1;

        while (!list_empty(&ep->queue)) {
                req = list_entry(ep->queue.next,
                                struct net2272_request,
                                queue);
                net2272_done(ep, req, -ESHUTDOWN);
        }
}

/* dequeue JUST ONE request */
static int
net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct net2272_ep *ep;
        struct net2272_request *req;
        unsigned long flags;
        int stopped;

        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0) || !_req)
                return -EINVAL;

        spin_lock_irqsave(&ep->dev->lock, flags);
        stopped = ep->stopped;
        ep->stopped = 1;

        /* make sure it's still queued on this endpoint */
        list_for_each_entry(req, &ep->queue, queue) {
                if (&req->req == _req)
                        break;
        }
        if (&req->req != _req) {
                ep->stopped = stopped;
                spin_unlock_irqrestore(&ep->dev->lock, flags);
                return -EINVAL;
        }

        /* queue head may be partially complete */
        if (ep->queue.next == &req->queue) {
                dev_dbg(ep->dev->dev, "unlink (%s) pio\n", _ep->name);
                net2272_done(ep, req, -ECONNRESET);
        }
        req = NULL;
        ep->stopped = stopped;

        spin_unlock_irqrestore(&ep->dev->lock, flags);
        return 0;
}

/*---------------------------------------------------------------------------*/

static int
net2272_set_halt_and_wedge(struct usb_ep *_ep, int value, int wedged)
{
        struct net2272_ep *ep;
        unsigned long flags;
        int ret = 0;

        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0))
                return -EINVAL;
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;
        if (ep->desc /* not ep0 */ && usb_endpoint_xfer_isoc(ep->desc))
                return -EINVAL;

        spin_lock_irqsave(&ep->dev->lock, flags);
        if (!list_empty(&ep->queue))
                ret = -EAGAIN;
        else if (ep->is_in && value && net2272_fifo_status(_ep) != 0)
                ret = -EAGAIN;
        else {
                dev_vdbg(ep->dev->dev, "%s %s %s\n", _ep->name,
                        value ? "set" : "clear",
                        wedged ? "wedge" : "halt");
                /* set/clear */
                if (value) {
                        if (ep->num == 0)
                                ep->dev->protocol_stall = 1;
                        else
                                set_halt(ep);
                        if (wedged)
                                ep->wedged = 1;
                } else {
                        clear_halt(ep);
                        ep->wedged = 0;

                }
        }
        spin_unlock_irqrestore(&ep->dev->lock, flags);

        return ret;
}

static int
net2272_set_halt(struct usb_ep *_ep, int value)
{
        return net2272_set_halt_and_wedge(_ep, value, 0);
}

static int
net2272_set_wedge(struct usb_ep *_ep)
{
        if (!_ep || _ep->name == ep0name)
                return -EINVAL;
        return net2272_set_halt_and_wedge(_ep, 1, 1);
}

static int
net2272_fifo_status(struct usb_ep *_ep)
{
        struct net2272_ep *ep;
        u16 avail;

        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0))
                return -ENODEV;
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        avail = net2272_ep_read(ep, EP_AVAIL1) << 8;
        avail |= net2272_ep_read(ep, EP_AVAIL0);
        if (avail > ep->fifo_size)
                return -EOVERFLOW;
        if (ep->is_in)
                avail = ep->fifo_size - avail;
        return avail;
}

static void
net2272_fifo_flush(struct usb_ep *_ep)
{
        struct net2272_ep *ep;

        ep = container_of(_ep, struct net2272_ep, ep);
        if (!_ep || (!ep->desc && ep->num != 0))
                return;
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
                return;

        net2272_ep_write(ep, EP_STAT1, 1 << BUFFER_FLUSH);
}

static const struct usb_ep_ops net2272_ep_ops = {
        .enable        = net2272_enable,
        .disable       = net2272_disable,

        .alloc_request = net2272_alloc_request,
        .free_request  = net2272_free_request,

        .queue         = net2272_queue,
        .dequeue       = net2272_dequeue,

        .set_halt      = net2272_set_halt,
        .set_wedge     = net2272_set_wedge,
        .fifo_status   = net2272_fifo_status,
        .fifo_flush    = net2272_fifo_flush,
};

/*---------------------------------------------------------------------------*/

static int
net2272_get_frame(struct usb_gadget *_gadget)
{
        struct net2272 *dev;
        unsigned long flags;
        u16 ret;

        if (!_gadget)
                return -ENODEV;
        dev = container_of(_gadget, struct net2272, gadget);
        spin_lock_irqsave(&dev->lock, flags);

        ret = net2272_read(dev, FRAME1) << 8;
        ret |= net2272_read(dev, FRAME0);

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

static int
net2272_wakeup(struct usb_gadget *_gadget)
{
        struct net2272 *dev;
        u8 tmp;
        unsigned long flags;

        if (!_gadget)
                return 0;
        dev = container_of(_gadget, struct net2272, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        tmp = net2272_read(dev, USBCTL0);
        if (tmp & (1 << IO_WAKEUP_ENABLE))
                net2272_write(dev, USBCTL1, (1 << GENERATE_RESUME));

        spin_unlock_irqrestore(&dev->lock, flags);

        return 0;
}

static int
net2272_set_selfpowered(struct usb_gadget *_gadget, int value)
{
        if (!_gadget)
                return -ENODEV;

        _gadget->is_selfpowered = (value != 0);

        return 0;
}

static int
net2272_pullup(struct usb_gadget *_gadget, int is_on)
{
        struct net2272 *dev;
        u8 tmp;
        unsigned long flags;

        if (!_gadget)
                return -ENODEV;
        dev = container_of(_gadget, struct net2272, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        tmp = net2272_read(dev, USBCTL0);
        dev->softconnect = (is_on != 0);
        if (is_on)
                tmp |= (1 << USB_DETECT_ENABLE);
        else
                tmp &= ~(1 << USB_DETECT_ENABLE);
        net2272_write(dev, USBCTL0, tmp);
        spin_unlock_irqrestore(&dev->lock, flags);

        return 0;
}

static int net2272_start(struct usb_gadget *_gadget,
                struct usb_gadget_driver *driver);
static int net2272_stop(struct usb_gadget *_gadget);

static const struct usb_gadget_ops net2272_ops = {
        .get_frame      = net2272_get_frame,
        .wakeup         = net2272_wakeup,
        .set_selfpowered = net2272_set_selfpowered,
        .pullup         = net2272_pullup,
        .udc_start      = net2272_start,
        .udc_stop       = net2272_stop,
};

/*---------------------------------------------------------------------------*/

static ssize_t
registers_show(struct device *_dev, struct device_attribute *attr, char *buf)
{
        struct net2272 *dev;
        char *next;
        unsigned size, t;
        unsigned long flags;
        u8 t1, t2;
        int i;
        const char *s;

        dev = dev_get_drvdata(_dev);
        next = buf;
        size = PAGE_SIZE;
        spin_lock_irqsave(&dev->lock, flags);

        /* Main Control Registers */
        t = scnprintf(next, size, "%s version %s,"
                "chiprev %02x, locctl %02x\n"
                "irqenb0 %02x irqenb1 %02x "
                "irqstat0 %02x irqstat1 %02x\n",
                driver_name, driver_vers, dev->chiprev,
                net2272_read(dev, LOCCTL),
                net2272_read(dev, IRQENB0),
                net2272_read(dev, IRQENB1),
                net2272_read(dev, IRQSTAT0),
                net2272_read(dev, IRQSTAT1));
        size -= t;
        next += t;

        /* DMA */
        t1 = net2272_read(dev, DMAREQ);
        t = scnprintf(next, size, "\ndmareq %02x: %s %s%s%s%s\n",
                t1, ep_name[(t1 & 0x01) + 1],
                t1 & (1 << DMA_CONTROL_DACK) ? "dack " : "",
                t1 & (1 << DMA_REQUEST_ENABLE) ? "reqenb " : "",
                t1 & (1 << DMA_REQUEST) ? "req " : "",
                t1 & (1 << DMA_BUFFER_VALID) ? "valid " : "");
        size -= t;
        next += t;

        /* USB Control Registers */
        t1 = net2272_read(dev, USBCTL1);
        if (t1 & (1 << VBUS_PIN)) {
                if (t1 & (1 << USB_HIGH_SPEED))
                        s = "high speed";
                else if (dev->gadget.speed == USB_SPEED_UNKNOWN)
                        s = "powered";
                else
                        s = "full speed";
        } else
                s = "not attached";
        t = scnprintf(next, size,
                "usbctl0 %02x usbctl1 %02x addr 0x%02x (%s)\n",
                net2272_read(dev, USBCTL0), t1,
                net2272_read(dev, OURADDR), s);
        size -= t;
        next += t;

        /* Endpoint Registers */
        for (i = 0; i < 4; ++i) {
                struct net2272_ep *ep;

                ep = &dev->ep[i];
                if (i && !ep->desc)
                        continue;

                t1 = net2272_ep_read(ep, EP_CFG);
                t2 = net2272_ep_read(ep, EP_RSPSET);
                t = scnprintf(next, size,
                        "\n%s\tcfg %02x rsp (%02x) %s%s%s%s%s%s%s%s"
                        "irqenb %02x\n",
                        ep->ep.name, t1, t2,
                        (t2 & (1 << ALT_NAK_OUT_PACKETS)) ? "NAK " : "",
                        (t2 & (1 << HIDE_STATUS_PHASE)) ? "hide " : "",
                        (t2 & (1 << AUTOVALIDATE)) ? "auto " : "",
                        (t2 & (1 << INTERRUPT_MODE)) ? "interrupt " : "",
                        (t2 & (1 << CONTROL_STATUS_PHASE_HANDSHAKE)) ? "status " : "",
                        (t2 & (1 << NAK_OUT_PACKETS_MODE)) ? "NAKmode " : "",
                        (t2 & (1 << ENDPOINT_TOGGLE)) ? "DATA1 " : "DATA0 ",
                        (t2 & (1 << ENDPOINT_HALT)) ? "HALT " : "",
                        net2272_ep_read(ep, EP_IRQENB));
                size -= t;
                next += t;

                t = scnprintf(next, size,
                        "\tstat0 %02x stat1 %02x avail %04x "
                        "(ep%d%s-%s)%s\n",
                        net2272_ep_read(ep, EP_STAT0),
                        net2272_ep_read(ep, EP_STAT1),
                        (net2272_ep_read(ep, EP_AVAIL1) << 8) | net2272_ep_read(ep, EP_AVAIL0),
                        t1 & 0x0f,
                        ep->is_in ? "in" : "out",
                        type_string(t1 >> 5),
                        ep->stopped ? "*" : "");
                size -= t;
                next += t;

                t = scnprintf(next, size,
                        "\tep_transfer %06x\n",
                        ((net2272_ep_read(ep, EP_TRANSFER2) & 0xff) << 16) |
                        ((net2272_ep_read(ep, EP_TRANSFER1) & 0xff) << 8) |
                        ((net2272_ep_read(ep, EP_TRANSFER0) & 0xff)));
                size -= t;
                next += t;

                t1 = net2272_ep_read(ep, EP_BUFF_STATES) & 0x03;
                t2 = (net2272_ep_read(ep, EP_BUFF_STATES) >> 2) & 0x03;
                t = scnprintf(next, size,
                        "\tbuf-a %s buf-b %s\n",
                        buf_state_string(t1),
                        buf_state_string(t2));
                size -= t;
                next += t;
        }

        spin_unlock_irqrestore(&dev->lock, flags);

        return PAGE_SIZE - size;
}
static DEVICE_ATTR_RO(registers);

/*---------------------------------------------------------------------------*/

static void
net2272_set_fifo_mode(struct net2272 *dev, int mode)
{
        u8 tmp;

        tmp = net2272_read(dev, LOCCTL) & 0x3f;
        tmp |= (mode << 6);
        net2272_write(dev, LOCCTL, tmp);

        INIT_LIST_HEAD(&dev->gadget.ep_list);

        /* always ep-a, ep-c ... maybe not ep-b */
        list_add_tail(&dev->ep[1].ep.ep_list, &dev->gadget.ep_list);

        switch (mode) {
        case 0:
                list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
                dev->ep[1].fifo_size = dev->ep[2].fifo_size = 512;
                break;
        case 1:
                list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
                dev->ep[1].fifo_size = 1024;
                dev->ep[2].fifo_size = 512;
                break;
        case 2:
                list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
                dev->ep[1].fifo_size = dev->ep[2].fifo_size = 1024;
                break;
        case 3:
                dev->ep[1].fifo_size = 1024;
                break;
        }

        /* ep-c is always 2 512 byte buffers */
        list_add_tail(&dev->ep[3].ep.ep_list, &dev->gadget.ep_list);
        dev->ep[3].fifo_size = 512;
}

/*---------------------------------------------------------------------------*/

static void
net2272_usb_reset(struct net2272 *dev)
{
        dev->gadget.speed = USB_SPEED_UNKNOWN;

        net2272_cancel_dma(dev);

        net2272_write(dev, IRQENB0, 0);
        net2272_write(dev, IRQENB1, 0);

        /* clear irq state */
        net2272_write(dev, IRQSTAT0, 0xff);
        net2272_write(dev, IRQSTAT1, ~(1 << SUSPEND_REQUEST_INTERRUPT));

        net2272_write(dev, DMAREQ,
                (0 << DMA_BUFFER_VALID) |
                (0 << DMA_REQUEST_ENABLE) |
                (1 << DMA_CONTROL_DACK) |
                (dev->dma_eot_polarity << EOT_POLARITY) |
                (dev->dma_dack_polarity << DACK_POLARITY) |
                (dev->dma_dreq_polarity << DREQ_POLARITY) |
                ((dma_ep >> 1) << DMA_ENDPOINT_SELECT));

        net2272_cancel_dma(dev);
        net2272_set_fifo_mode(dev, (fifo_mode <= 3) ? fifo_mode : 0);

        /* Set the NET2272 ep fifo data width to 16-bit mode and for correct byte swapping
         * note that the higher level gadget drivers are expected to convert data to little endian.
         * Enable byte swap for your local bus/cpu if needed by setting BYTE_SWAP in LOCCTL here
         */
        net2272_write(dev, LOCCTL, net2272_read(dev, LOCCTL) | (1 << DATA_WIDTH));
        net2272_write(dev, LOCCTL1, (dma_mode << DMA_MODE));
}

static void
net2272_usb_reinit(struct net2272 *dev)
{
        int i;

        /* basic endpoint init */
        for (i = 0; i < 4; ++i) {
                struct net2272_ep *ep = &dev->ep[i];

                ep->ep.name = ep_name[i];
                ep->dev = dev;
                ep->num = i;
                ep->not_empty = 0;

                if (use_dma && ep->num == dma_ep)
                        ep->dma = 1;

                if (i > 0 && i <= 3)
                        ep->fifo_size = 512;
                else
                        ep->fifo_size = 64;
                net2272_ep_reset(ep);

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

                ep->ep.caps.dir_in = true;
                ep->ep.caps.dir_out = true;
        }
        usb_ep_set_maxpacket_limit(&dev->ep[0].ep, 64);

        dev->gadget.ep0 = &dev->ep[0].ep;
        dev->ep[0].stopped = 0;
        INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);
}

static void
net2272_ep0_start(struct net2272 *dev)
{
        struct net2272_ep *ep0 = &dev->ep[0];

        net2272_ep_write(ep0, EP_RSPSET,
                (1 << NAK_OUT_PACKETS_MODE) |
                (1 << ALT_NAK_OUT_PACKETS));
        net2272_ep_write(ep0, EP_RSPCLR,
                (1 << HIDE_STATUS_PHASE) |
                (1 << CONTROL_STATUS_PHASE_HANDSHAKE));
        net2272_write(dev, USBCTL0,
                (dev->softconnect << USB_DETECT_ENABLE) |
                (1 << USB_ROOT_PORT_WAKEUP_ENABLE) |
                (1 << IO_WAKEUP_ENABLE));
        net2272_write(dev, IRQENB0,
                (1 << SETUP_PACKET_INTERRUPT_ENABLE) |
                (1 << ENDPOINT_0_INTERRUPT_ENABLE) |
                (1 << DMA_DONE_INTERRUPT_ENABLE));
        net2272_write(dev, IRQENB1,
                (1 << VBUS_INTERRUPT_ENABLE) |
                (1 << ROOT_PORT_RESET_INTERRUPT_ENABLE) |
                (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT_ENABLE));
}

/* when a driver is successfully registered, it will receive
 * control requests including set_configuration(), which enables
 * non-control requests.  then usb traffic follows until a
 * disconnect is reported.  then a host may connect again, or
 * the driver might get unbound.
 */
static int net2272_start(struct usb_gadget *_gadget,
                struct usb_gadget_driver *driver)
{
        struct net2272 *dev;
        unsigned i;

        if (!driver || !driver->setup ||
            driver->max_speed != USB_SPEED_HIGH)
                return -EINVAL;

        dev = container_of(_gadget, struct net2272, gadget);

        for (i = 0; i < 4; ++i)
                dev->ep[i].irqs = 0;
        /* hook up the driver ... */
        dev->softconnect = 1;
        driver->driver.bus = NULL;
        dev->driver = driver;

        /* ... then enable host detection and ep0; and we're ready
         * for set_configuration as well as eventual disconnect.
         */
        net2272_ep0_start(dev);

        return 0;
}

static void
stop_activity(struct net2272 *dev, struct usb_gadget_driver *driver)
{
        int i;

        /* don't disconnect if it's not connected */
        if (dev->gadget.speed == USB_SPEED_UNKNOWN)
                driver = NULL;

        /* stop hardware; prevent new request submissions;
         * and kill any outstanding requests.
         */
        net2272_usb_reset(dev);
        for (i = 0; i < 4; ++i)
                net2272_dequeue_all(&dev->ep[i]);

        /* report disconnect; the driver is already quiesced */
        if (driver) {
                spin_unlock(&dev->lock);
                driver->disconnect(&dev->gadget);
                spin_lock(&dev->lock);
        }

        net2272_usb_reinit(dev);
}

static int net2272_stop(struct usb_gadget *_gadget)
{
        struct net2272 *dev;
        unsigned long flags;

        dev = container_of(_gadget, struct net2272, gadget);

        spin_lock_irqsave(&dev->lock, flags);
        stop_activity(dev, NULL);
        spin_unlock_irqrestore(&dev->lock, flags);

        dev->driver = NULL;

        return 0;
}

/*---------------------------------------------------------------------------*/
/* handle ep-a/ep-b dma completions */
static void
net2272_handle_dma(struct net2272_ep *ep)
{
        struct net2272_request *req;
        unsigned len;
        int status;

        if (!list_empty(&ep->queue))
                req = list_entry(ep->queue.next,
                                struct net2272_request, queue);
        else
                req = NULL;

        dev_vdbg(ep->dev->dev, "handle_dma %s req %p\n", ep->ep.name, req);

        /* Ensure DREQ is de-asserted */
        net2272_write(ep->dev, DMAREQ,
                (0 << DMA_BUFFER_VALID)
              | (0 << DMA_REQUEST_ENABLE)
              | (1 << DMA_CONTROL_DACK)
              | (ep->dev->dma_eot_polarity << EOT_POLARITY)
              | (ep->dev->dma_dack_polarity << DACK_POLARITY)
              | (ep->dev->dma_dreq_polarity << DREQ_POLARITY)
              | (ep->dma << DMA_ENDPOINT_SELECT));

        ep->dev->dma_busy = 0;

        net2272_ep_write(ep, EP_IRQENB,
                  (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
                | (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
                | net2272_ep_read(ep, EP_IRQENB));

        /* device-to-host transfer completed */
        if (ep->is_in) {
                /* validate a short packet or zlp if necessary */
                if ((req->req.length % ep->ep.maxpacket != 0) ||
                                req->req.zero)
                        set_fifo_bytecount(ep, 0);

                net2272_done(ep, req, 0);
                if (!list_empty(&ep->queue)) {
                        req = list_entry(ep->queue.next,
                                        struct net2272_request, queue);
                        status = net2272_kick_dma(ep, req);
                        if (status < 0)
                                net2272_pio_advance(ep);
                }

        /* host-to-device transfer completed */
        } else {
                /* terminated with a short packet? */
                if (net2272_read(ep->dev, IRQSTAT0) &
                                (1 << DMA_DONE_INTERRUPT)) {
                        /* abort system dma */
                        net2272_cancel_dma(ep->dev);
                }

                /* EP_TRANSFER will contain the number of bytes
                 * actually received.
                 * NOTE: There is no overflow detection on EP_TRANSFER:
                 * We can't deal with transfers larger than 2^24 bytes!
                 */
                len = (net2272_ep_read(ep, EP_TRANSFER2) << 16)
                        | (net2272_ep_read(ep, EP_TRANSFER1) << 8)
                        | (net2272_ep_read(ep, EP_TRANSFER0));

                if (ep->not_empty)
                        len += 4;

                req->req.actual += len;

                /* get any remaining data */
                net2272_pio_advance(ep);
        }
}

/*---------------------------------------------------------------------------*/

static void
net2272_handle_ep(struct net2272_ep *ep)
{
        struct net2272_request *req;
        u8 stat0, stat1;

        if (!list_empty(&ep->queue))
                req = list_entry(ep->queue.next,
                        struct net2272_request, queue);
        else
                req = NULL;

        /* ack all, and handle what we care about */
        stat0 = net2272_ep_read(ep, EP_STAT0);
        stat1 = net2272_ep_read(ep, EP_STAT1);
        ep->irqs++;

        dev_vdbg(ep->dev->dev, "%s ack ep_stat0 %02x, ep_stat1 %02x, req %p\n",
                ep->ep.name, stat0, stat1, req ? &req->req : NULL);

        net2272_ep_write(ep, EP_STAT0, stat0 &
                ~((1 << NAK_OUT_PACKETS)
                | (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)));
        net2272_ep_write(ep, EP_STAT1, stat1);

        /* data packet(s) received (in the fifo, OUT)
         * direction must be validated, otherwise control read status phase
         * could be interpreted as a valid packet
         */
        if (!ep->is_in && (stat0 & (1 << DATA_PACKET_RECEIVED_INTERRUPT)))
                net2272_pio_advance(ep);
        /* data packet(s) transmitted (IN) */
        else if (stat0 & (1 << DATA_PACKET_TRANSMITTED_INTERRUPT))
                net2272_pio_advance(ep);
}

static struct net2272_ep *
net2272_get_ep_by_addr(struct net2272 *dev, u16 wIndex)
{
        struct net2272_ep *ep;

        if ((wIndex & USB_ENDPOINT_NUMBER_MASK) == 0)
                return &dev->ep[0];

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

                if (!ep->desc)
                        continue;
                bEndpointAddress = ep->desc->bEndpointAddress;
                if ((wIndex ^ bEndpointAddress) & USB_DIR_IN)
                        continue;
                if ((wIndex & 0x0f) == (bEndpointAddress & 0x0f))
                        return ep;
        }
        return NULL;
}

/*
 * USB Test Packet:
 * JKJKJKJK * 9
 * JJKKJJKK * 8
 * JJJJKKKK * 8
 * JJJJJJJKKKKKKK * 8
 * JJJJJJJK * 8
 * {JKKKKKKK * 10}, JK
 */
static const u8 net2272_test_packet[] = {
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
        0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE,
        0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0x7F, 0xBF, 0xDF, 0xEF, 0xF7, 0xFB, 0xFD,
        0xFC, 0x7E, 0xBF, 0xDF, 0xEF, 0xF7, 0xFD, 0x7E
};

static void
net2272_set_test_mode(struct net2272 *dev, int mode)
{
        int i;

        /* Disable all net2272 interrupts:
         * Nothing but a power cycle should stop the test.
         */
        net2272_write(dev, IRQENB0, 0x00);
        net2272_write(dev, IRQENB1, 0x00);

        /* Force tranceiver to high-speed */
        net2272_write(dev, XCVRDIAG, 1 << FORCE_HIGH_SPEED);

        net2272_write(dev, PAGESEL, 0);
        net2272_write(dev, EP_STAT0, 1 << DATA_PACKET_TRANSMITTED_INTERRUPT);
        net2272_write(dev, EP_RSPCLR,
                          (1 << CONTROL_STATUS_PHASE_HANDSHAKE)
                        | (1 << HIDE_STATUS_PHASE));
        net2272_write(dev, EP_CFG, 1 << ENDPOINT_DIRECTION);
        net2272_write(dev, EP_STAT1, 1 << BUFFER_FLUSH);

        /* wait for status phase to complete */
        while (!(net2272_read(dev, EP_STAT0) &
                                (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)))
                ;

        /* Enable test mode */
        net2272_write(dev, USBTEST, mode);

        /* load test packet */
        if (mode == USB_TEST_PACKET) {
                /* switch to 8 bit mode */
                net2272_write(dev, LOCCTL, net2272_read(dev, LOCCTL) &
                                ~(1 << DATA_WIDTH));

                for (i = 0; i < sizeof(net2272_test_packet); ++i)
                        net2272_write(dev, EP_DATA, net2272_test_packet[i]);

                /* Validate test packet */
                net2272_write(dev, EP_TRANSFER0, 0);
        }
}

static void
net2272_handle_stat0_irqs(struct net2272 *dev, u8 stat)
{
        struct net2272_ep *ep;
        u8 num, scratch;

        /* starting a control request? */
        if (unlikely(stat & (1 << SETUP_PACKET_INTERRUPT))) {
                union {
                        u8 raw[8];
                        struct usb_ctrlrequest  r;
                } u;
                int tmp = 0;
                struct net2272_request *req;

                if (dev->gadget.speed == USB_SPEED_UNKNOWN) {
                        if (net2272_read(dev, USBCTL1) & (1 << USB_HIGH_SPEED))
                                dev->gadget.speed = USB_SPEED_HIGH;
                        else
                                dev->gadget.speed = USB_SPEED_FULL;
                        dev_dbg(dev->dev, "%s\n",
                                usb_speed_string(dev->gadget.speed));
                }

                ep = &dev->ep[0];
                ep->irqs++;

                /* make sure any leftover interrupt state is cleared */
                stat &= ~(1 << ENDPOINT_0_INTERRUPT);
                while (!list_empty(&ep->queue)) {
                        req = list_entry(ep->queue.next,
                                struct net2272_request, queue);
                        net2272_done(ep, req,
                                (req->req.actual == req->req.length) ? 0 : -EPROTO);
                }
                ep->stopped = 0;
                dev->protocol_stall = 0;
                net2272_ep_write(ep, EP_STAT0,
                            (1 << DATA_IN_TOKEN_INTERRUPT)
                          | (1 << DATA_OUT_TOKEN_INTERRUPT)
                          | (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
                          | (1 << DATA_PACKET_RECEIVED_INTERRUPT)
                          | (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT));
                net2272_ep_write(ep, EP_STAT1,
                            (1 << TIMEOUT)
                          | (1 << USB_OUT_ACK_SENT)
                          | (1 << USB_OUT_NAK_SENT)
                          | (1 << USB_IN_ACK_RCVD)
                          | (1 << USB_IN_NAK_SENT)
                          | (1 << USB_STALL_SENT)
                          | (1 << LOCAL_OUT_ZLP));

                /*
                 * Ensure Control Read pre-validation setting is beyond maximum size
                 *  - Control Writes can leave non-zero values in EP_TRANSFER. If
                 *    an EP0 transfer following the Control Write is a Control Read,
                 *    the NET2272 sees the non-zero EP_TRANSFER as an unexpected
                 *    pre-validation count.
                 *  - Setting EP_TRANSFER beyond the maximum EP0 transfer size ensures
                 *    the pre-validation count cannot cause an unexpected validatation
                 */
                net2272_write(dev, PAGESEL, 0);
                net2272_write(dev, EP_TRANSFER2, 0xff);
                net2272_write(dev, EP_TRANSFER1, 0xff);
                net2272_write(dev, EP_TRANSFER0, 0xff);

                u.raw[0] = net2272_read(dev, SETUP0);
                u.raw[1] = net2272_read(dev, SETUP1);
                u.raw[2] = net2272_read(dev, SETUP2);
                u.raw[3] = net2272_read(dev, SETUP3);
                u.raw[4] = net2272_read(dev, SETUP4);
                u.raw[5] = net2272_read(dev, SETUP5);
                u.raw[6] = net2272_read(dev, SETUP6);
                u.raw[7] = net2272_read(dev, SETUP7);
                /*
                 * If you have a big endian cpu make sure le16_to_cpus
                 * performs the proper byte swapping here...
                 */
                le16_to_cpus(&u.r.wValue);
                le16_to_cpus(&u.r.wIndex);
                le16_to_cpus(&u.r.wLength);

                /* ack the irq */
                net2272_write(dev, IRQSTAT0, 1 << SETUP_PACKET_INTERRUPT);
                stat ^= (1 << SETUP_PACKET_INTERRUPT);

                /* watch control traffic at the token level, and force
                 * synchronization before letting the status phase happen.
                 */
                ep->is_in = (u.r.bRequestType & USB_DIR_IN) != 0;
                if (ep->is_in) {
                        scratch = (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
                                | (1 << DATA_OUT_TOKEN_INTERRUPT_ENABLE)
                                | (1 << DATA_IN_TOKEN_INTERRUPT_ENABLE);
                        stop_out_naking(ep);
                } else
                        scratch = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
                                | (1 << DATA_OUT_TOKEN_INTERRUPT_ENABLE)
                                | (1 << DATA_IN_TOKEN_INTERRUPT_ENABLE);
                net2272_ep_write(ep, EP_IRQENB, scratch);

                if ((u.r.bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
                        goto delegate;
                switch (u.r.bRequest) {
                case USB_REQ_GET_STATUS: {
                        struct net2272_ep *e;
                        u16 status = 0;

                        switch (u.r.bRequestType & USB_RECIP_MASK) {
                        case USB_RECIP_ENDPOINT:
                                e = net2272_get_ep_by_addr(dev, u.r.wIndex);
                                if (!e || u.r.wLength > 2)
                                        goto do_stall;
                                if (net2272_ep_read(e, EP_RSPSET) & (1 << ENDPOINT_HALT))
                                        status = cpu_to_le16(1);
                                else
                                        status = cpu_to_le16(0);

                                /* don't bother with a request object! */
                                net2272_ep_write(&dev->ep[0], EP_IRQENB, 0);
                                writew(status, net2272_reg_addr(dev, EP_DATA));
                                set_fifo_bytecount(&dev->ep[0], 0);
                                allow_status(ep);
                                dev_vdbg(dev->dev, "%s stat %02x\n",
                                        ep->ep.name, status);
                                goto next_endpoints;
                        case USB_RECIP_DEVICE:
                                if (u.r.wLength > 2)
                                        goto do_stall;
                                if (dev->gadget.is_selfpowered)
                                        status = (1 << USB_DEVICE_SELF_POWERED);

                                /* don't bother with a request object! */
                                net2272_ep_write(&dev->ep[0], EP_IRQENB, 0);
                                writew(status, net2272_reg_addr(dev, EP_DATA));
                                set_fifo_bytecount(&dev->ep[0], 0);
                                allow_status(ep);
                                dev_vdbg(dev->dev, "device stat %02x\n", status);
                                goto next_endpoints;
                        case USB_RECIP_INTERFACE:
                                if (u.r.wLength > 2)
                                        goto do_stall;

                                /* don't bother with a request object! */
                                net2272_ep_write(&dev->ep[0], EP_IRQENB, 0);
                                writew(status, net2272_reg_addr(dev, EP_DATA));
                                set_fifo_bytecount(&dev->ep[0], 0);
                                allow_status(ep);
                                dev_vdbg(dev->dev, "interface status %02x\n", status);
                                goto next_endpoints;
                        }

                        break;
                }
                case USB_REQ_CLEAR_FEATURE: {
                        struct net2272_ep *e;

                        if (u.r.bRequestType != USB_RECIP_ENDPOINT)
                                goto delegate;
                        if (u.r.wValue != USB_ENDPOINT_HALT ||
                            u.r.wLength != 0)
                                goto do_stall;
                        e = net2272_get_ep_by_addr(dev, u.r.wIndex);
                        if (!e)
                                goto do_stall;
                        if (e->wedged) {
                                dev_vdbg(dev->dev, "%s wedged, halt not cleared\n",
                                        ep->ep.name);
                        } else {
                                dev_vdbg(dev->dev, "%s clear halt\n", ep->ep.name);
                                clear_halt(e);
                        }
                        allow_status(ep);
                        goto next_endpoints;
                }
                case USB_REQ_SET_FEATURE: {
                        struct net2272_ep *e;

                        if (u.r.bRequestType == USB_RECIP_DEVICE) {
                                if (u.r.wIndex != NORMAL_OPERATION)
                                        net2272_set_test_mode(dev, (u.r.wIndex >> 8));
                                allow_status(ep);
                                dev_vdbg(dev->dev, "test mode: %d\n", u.r.wIndex);
                                goto next_endpoints;
                        } else if (u.r.bRequestType != USB_RECIP_ENDPOINT)
                                goto delegate;
                        if (u.r.wValue != USB_ENDPOINT_HALT ||
                            u.r.wLength != 0)
                                goto do_stall;
                        e = net2272_get_ep_by_addr(dev, u.r.wIndex);
                        if (!e)
                                goto do_stall;
                        set_halt(e);
                        allow_status(ep);
                        dev_vdbg(dev->dev, "%s set halt\n", ep->ep.name);
                        goto next_endpoints;
                }
                case USB_REQ_SET_ADDRESS: {
                        net2272_write(dev, OURADDR, u.r.wValue & 0xff);
                        allow_status(ep);
                        break;
                }
                default:
 delegate:
                        dev_vdbg(dev->dev, "setup %02x.%02x v%04x i%04x "
                                "ep_cfg %08x\n",
                                u.r.bRequestType, u.r.bRequest,
                                u.r.wValue, u.r.wIndex,
                                net2272_ep_read(ep, EP_CFG));
                        spin_unlock(&dev->lock);
                        tmp = dev->driver->setup(&dev->gadget, &u.r);
                        spin_lock(&dev->lock);
                }

                /* stall ep0 on error */
                if (tmp < 0) {
 do_stall:
                        dev_vdbg(dev->dev, "req %02x.%02x protocol STALL; stat %d\n",
                                u.r.bRequestType, u.r.bRequest, tmp);
                        dev->protocol_stall = 1;
                }
        /* endpoint dma irq? */
        } else if (stat & (1 << DMA_DONE_INTERRUPT)) {
                net2272_cancel_dma(dev);
                net2272_write(dev, IRQSTAT0, 1 << DMA_DONE_INTERRUPT);
                stat &= ~(1 << DMA_DONE_INTERRUPT);
                num = (net2272_read(dev, DMAREQ) & (1 << DMA_ENDPOINT_SELECT))
                        ? 2 : 1;

                ep = &dev->ep[num];
                net2272_handle_dma(ep);
        }

 next_endpoints:
        /* endpoint data irq? */
        scratch = stat & 0x0f;
        stat &= ~0x0f;
        for (num = 0; scratch; num++) {
                u8 t;

                /* does this endpoint's FIFO and queue need tending? */
                t = 1 << num;
                if ((scratch & t) == 0)
                        continue;
                scratch ^= t;

                ep = &dev->ep[num];
                net2272_handle_ep(ep);
        }

        /* some interrupts we can just ignore */
        stat &= ~(1 << SOF_INTERRUPT);

        if (stat)
                dev_dbg(dev->dev, "unhandled irqstat0 %02x\n", stat);
}

static void
net2272_handle_stat1_irqs(struct net2272 *dev, u8 stat)
{
        u8 tmp, mask;

        /* after disconnect there's nothing else to do! */
        tmp = (1 << VBUS_INTERRUPT) | (1 << ROOT_PORT_RESET_INTERRUPT);
        mask = (1 << USB_HIGH_SPEED) | (1 << USB_FULL_SPEED);

        if (stat & tmp) {
                bool    reset = false;
                bool    disconnect = false;

                /*
                 * Ignore disconnects and resets if the speed hasn't been set.
                 * VBUS can bounce and there's always an initial reset.
                 */
                net2272_write(dev, IRQSTAT1, tmp);
                if (dev->gadget.speed != USB_SPEED_UNKNOWN) {
                        if ((stat & (1 << VBUS_INTERRUPT)) &&
                                        (net2272_read(dev, USBCTL1) &
                                                (1 << VBUS_PIN)) == 0) {
                                disconnect = true;
                                dev_dbg(dev->dev, "disconnect %s\n",
                                        dev->driver->driver.name);
                        } else if ((stat & (1 << ROOT_PORT_RESET_INTERRUPT)) &&
                                        (net2272_read(dev, USBCTL1) & mask)
                                                == 0) {
                                reset = true;
                                dev_dbg(dev->dev, "reset %s\n",
                                        dev->driver->driver.name);
                        }

                        if (disconnect || reset) {
                                stop_activity(dev, dev->driver);
                                net2272_ep0_start(dev);
                                spin_unlock(&dev->lock);
                                if (reset)
                                        usb_gadget_udc_reset
                                                (&dev->gadget, dev->driver);

                                else
                                        (dev->driver->disconnect)
                                                (&dev->gadget);
                                spin_lock(&dev->lock);
                                return;
                        }
                }
                stat &= ~tmp;

                if (!stat)
                        return;
        }

        tmp = (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT);
        if (stat & tmp) {
                net2272_write(dev, IRQSTAT1, tmp);
                if (stat & (1 << SUSPEND_REQUEST_INTERRUPT)) {
                        if (dev->driver->suspend)
                                dev->driver->suspend(&dev->gadget);
                        if (!enable_suspend) {
                                stat &= ~(1 << SUSPEND_REQUEST_INTERRUPT);
                                dev_dbg(dev->dev, "Suspend disabled, ignoring\n");
                        }
                } else {
                        if (dev->driver->resume)
                                dev->driver->resume(&dev->gadget);
                }
                stat &= ~tmp;
        }

        /* clear any other status/irqs */
        if (stat)
                net2272_write(dev, IRQSTAT1, stat);

        /* some status we can just ignore */
        stat &= ~((1 << CONTROL_STATUS_INTERRUPT)
                        | (1 << SUSPEND_REQUEST_INTERRUPT)
                        | (1 << RESUME_INTERRUPT));
        if (!stat)
                return;
        else
                dev_dbg(dev->dev, "unhandled irqstat1 %02x\n", stat);
}

static irqreturn_t net2272_irq(int irq, void *_dev)
{
        struct net2272 *dev = _dev;
#if defined(PLX_PCI_RDK) || defined(PLX_PCI_RDK2)
        u32 intcsr;
#endif
#if defined(PLX_PCI_RDK)
        u8 dmareq;
#endif
        spin_lock(&dev->lock);
#if defined(PLX_PCI_RDK)
        intcsr = readl(dev->rdk1.plx9054_base_addr + INTCSR);

        if ((intcsr & LOCAL_INTERRUPT_TEST) == LOCAL_INTERRUPT_TEST) {
                writel(intcsr & ~(1 << PCI_INTERRUPT_ENABLE),
                                dev->rdk1.plx9054_base_addr + INTCSR);
                net2272_handle_stat1_irqs(dev, net2272_read(dev, IRQSTAT1));
                net2272_handle_stat0_irqs(dev, net2272_read(dev, IRQSTAT0));
                intcsr = readl(dev->rdk1.plx9054_base_addr + INTCSR);
                writel(intcsr | (1 << PCI_INTERRUPT_ENABLE),
                        dev->rdk1.plx9054_base_addr + INTCSR);
        }
        if ((intcsr & DMA_CHANNEL_0_TEST) == DMA_CHANNEL_0_TEST) {
                writeb((1 << CHANNEL_CLEAR_INTERRUPT | (0 << CHANNEL_ENABLE)),
                                dev->rdk1.plx9054_base_addr + DMACSR0);

                dmareq = net2272_read(dev, DMAREQ);
                if (dmareq & 0x01)
                        net2272_handle_dma(&dev->ep[2]);
                else
                        net2272_handle_dma(&dev->ep[1]);
        }
#endif
#if defined(PLX_PCI_RDK2)
        /* see if PCI int for us by checking irqstat */
        intcsr = readl(dev->rdk2.fpga_base_addr + RDK2_IRQSTAT);
        if (!(intcsr & (1 << NET2272_PCI_IRQ))) {
                spin_unlock(&dev->lock);
                return IRQ_NONE;
        }
        /* check dma interrupts */
#endif
        /* Platform/devcice interrupt handler */
#if !defined(PLX_PCI_RDK)
        net2272_handle_stat1_irqs(dev, net2272_read(dev, IRQSTAT1));
        net2272_handle_stat0_irqs(dev, net2272_read(dev, IRQSTAT0));
#endif
        spin_unlock(&dev->lock);

        return IRQ_HANDLED;
}

static int net2272_present(struct net2272 *dev)
{
        /*
         * Quick test to see if CPU can communicate properly with the NET2272.
         * Verifies connection using writes and reads to write/read and
         * read-only registers.
         *
         * This routine is strongly recommended especially during early bring-up
         * of new hardware, however for designs that do not apply Power On System
         * Tests (POST) it may discarded (or perhaps minimized).
         */
        unsigned int ii;
        u8 val, refval;

        /* Verify NET2272 write/read SCRATCH register can write and read */
        refval = net2272_read(dev, SCRATCH);
        for (ii = 0; ii < 0x100; ii += 7) {
                net2272_write(dev, SCRATCH, ii);
                val = net2272_read(dev, SCRATCH);
                if (val != ii) {
                        dev_dbg(dev->dev,
                                "%s: write/read SCRATCH register test failed: "
                                "wrote:0x%2.2x, read:0x%2.2x\n",
                                __func__, ii, val);
                        return -EINVAL;
                }
        }
        /* To be nice, we write the original SCRATCH value back: */
        net2272_write(dev, SCRATCH, refval);

        /* Verify NET2272 CHIPREV register is read-only: */
        refval = net2272_read(dev, CHIPREV_2272);
        for (ii = 0; ii < 0x100; ii += 7) {
                net2272_write(dev, CHIPREV_2272, ii);
                val = net2272_read(dev, CHIPREV_2272);
                if (val != refval) {
                        dev_dbg(dev->dev,
                                "%s: write/read CHIPREV register test failed: "
                                "wrote 0x%2.2x, read:0x%2.2x expected:0x%2.2x\n",
                                __func__, ii, val, refval);
                        return -EINVAL;
                }
        }

        /*
         * Verify NET2272's "NET2270 legacy revision" register
         *  - NET2272 has two revision registers. The NET2270 legacy revision
         *    register should read the same value, regardless of the NET2272
         *    silicon revision.  The legacy register applies to NET2270
         *    firmware being applied to the NET2272.
         */
        val = net2272_read(dev, CHIPREV_LEGACY);
        if (val != NET2270_LEGACY_REV) {
                /*
                 * Unexpected legacy revision value
                 * - Perhaps the chip is a NET2270?
                 */
                dev_dbg(dev->dev,
                        "%s: WARNING: UNEXPECTED NET2272 LEGACY REGISTER VALUE:\n"
                        " - CHIPREV_LEGACY: expected 0x%2.2x, got:0x%2.2x. (Not NET2272?)\n",
                        __func__, NET2270_LEGACY_REV, val);
                return -EINVAL;
        }

        /*
         * Verify NET2272 silicon revision
         *  - This revision register is appropriate for the silicon version
         *    of the NET2272
         */
        val = net2272_read(dev, CHIPREV_2272);
        switch (val) {
        case CHIPREV_NET2272_R1:
                /*
                 * NET2272 Rev 1 has DMA related errata:
                 *  - Newer silicon (Rev 1A or better) required
                 */
                dev_dbg(dev->dev,
                        "%s: Rev 1 detected: newer silicon recommended for DMA support\n",
                        __func__);
                break;
        case CHIPREV_NET2272_R1A:
                break;
        default:
                /* NET2272 silicon version *may* not work with this firmware */
                dev_dbg(dev->dev,
                        "%s: unexpected silicon revision register value: "
                        " CHIPREV_2272: 0x%2.2x\n",
                        __func__, val);
                /*
                 * Return Success, even though the chip rev is not an expected value
                 *  - Older, pre-built firmware can attempt to operate on newer silicon
                 *  - Often, new silicon is perfectly compatible
                 */
        }

        /* Success: NET2272 checks out OK */
        return 0;
}

static void
net2272_gadget_release(struct device *_dev)
{
        struct net2272 *dev = dev_get_drvdata(_dev);
        kfree(dev);
}

/*---------------------------------------------------------------------------*/

static void
net2272_remove(struct net2272 *dev)
{
        usb_del_gadget_udc(&dev->gadget);
        free_irq(dev->irq, dev);
        iounmap(dev->base_addr);
        device_remove_file(dev->dev, &dev_attr_registers);

        dev_info(dev->dev, "unbind\n");
}

static struct net2272 *net2272_probe_init(struct device *dev, unsigned int irq)
{
        struct net2272 *ret;

        if (!irq) {
                dev_dbg(dev, "No IRQ!\n");
                return ERR_PTR(-ENODEV);
        }

        /* alloc, and start init */
        ret = kzalloc(sizeof(*ret), GFP_KERNEL);
        if (!ret)
                return ERR_PTR(-ENOMEM);

        spin_lock_init(&ret->lock);
        ret->irq = irq;
        ret->dev = dev;
        ret->gadget.ops = &net2272_ops;
        ret->gadget.max_speed = USB_SPEED_HIGH;

        /* the "gadget" abstracts/virtualizes the controller */
        ret->gadget.name = driver_name;

        return ret;
}

static int
net2272_probe_fin(struct net2272 *dev, unsigned int irqflags)
{
        int ret;

        /* See if there... */
        if (net2272_present(dev)) {
                dev_warn(dev->dev, "2272 not found!\n");
                ret = -ENODEV;
                goto err;
        }

        net2272_usb_reset(dev);
        net2272_usb_reinit(dev);

        ret = request_irq(dev->irq, net2272_irq, irqflags, driver_name, dev);
        if (ret) {
                dev_err(dev->dev, "request interrupt %i failed\n", dev->irq);
                goto err;
        }

        dev->chiprev = net2272_read(dev, CHIPREV_2272);

        /* done */
        dev_info(dev->dev, "%s\n", driver_desc);
        dev_info(dev->dev, "irq %i, mem %p, chip rev %04x, dma %s\n",
                dev->irq, dev->base_addr, dev->chiprev,
                dma_mode_string());
        dev_info(dev->dev, "version: %s\n", driver_vers);

        ret = device_create_file(dev->dev, &dev_attr_registers);
        if (ret)
                goto err_irq;

        ret = usb_add_gadget_udc_release(dev->dev, &dev->gadget,
                        net2272_gadget_release);
        if (ret)
                goto err_add_udc;

        return 0;

err_add_udc:
        device_remove_file(dev->dev, &dev_attr_registers);
 err_irq:
        free_irq(dev->irq, dev);
 err:
        return ret;
}

#ifdef CONFIG_USB_PCI

/*
 * wrap this driver around the specified device, but
 * don't respond over USB until a gadget driver binds to us
 */

static int
net2272_rdk1_probe(struct pci_dev *pdev, struct net2272 *dev)
{
        unsigned long resource, len, tmp;
        void __iomem *mem_mapped_addr[4];
        int ret, i;

        /*
         * BAR 0 holds PLX 9054 config registers
         * BAR 1 is i/o memory; unused here
         * BAR 2 holds EPLD config registers
         * BAR 3 holds NET2272 registers
         */

        /* Find and map all address spaces */
        for (i = 0; i < 4; ++i) {
                if (i == 1)
                        continue;       /* BAR1 unused */

                resource = pci_resource_start(pdev, i);
                len = pci_resource_len(pdev, i);

                if (!request_mem_region(resource, len, driver_name)) {
                        dev_dbg(dev->dev, "controller already in use\n");
                        ret = -EBUSY;
                        goto err;
                }

                mem_mapped_addr[i] = ioremap(resource, len);
                if (mem_mapped_addr[i] == NULL) {
                        release_mem_region(resource, len);
                        dev_dbg(dev->dev, "can't map memory\n");
                        ret = -EFAULT;
                        goto err;
                }
        }

        dev->rdk1.plx9054_base_addr = mem_mapped_addr[0];
        dev->rdk1.epld_base_addr = mem_mapped_addr[2];
        dev->base_addr = mem_mapped_addr[3];

        /* Set PLX 9054 bus width (16 bits) */
        tmp = readl(dev->rdk1.plx9054_base_addr + LBRD1);
        writel((tmp & ~(3 << MEMORY_SPACE_LOCAL_BUS_WIDTH)) | W16_BIT,
                        dev->rdk1.plx9054_base_addr + LBRD1);

        /* Enable PLX 9054 Interrupts */
        writel(readl(dev->rdk1.plx9054_base_addr + INTCSR) |
                        (1 << PCI_INTERRUPT_ENABLE) |
                        (1 << LOCAL_INTERRUPT_INPUT_ENABLE),
                        dev->rdk1.plx9054_base_addr + INTCSR);

        writeb((1 << CHANNEL_CLEAR_INTERRUPT | (0 << CHANNEL_ENABLE)),
                        dev->rdk1.plx9054_base_addr + DMACSR0);

        /* reset */
        writeb((1 << EPLD_DMA_ENABLE) |
                (1 << DMA_CTL_DACK) |
                (1 << DMA_TIMEOUT_ENABLE) |
                (1 << USER) |
                (0 << MPX_MODE) |
                (1 << BUSWIDTH) |
                (1 << NET2272_RESET),
                dev->base_addr + EPLD_IO_CONTROL_REGISTER);

        mb();
        writeb(readb(dev->base_addr + EPLD_IO_CONTROL_REGISTER) &
                ~(1 << NET2272_RESET),
                dev->base_addr + EPLD_IO_CONTROL_REGISTER);
        udelay(200);

        return 0;

 err:
        while (--i >= 0) {
                if (i == 1)
                        continue;       /* BAR1 unused */
                iounmap(mem_mapped_addr[i]);
                release_mem_region(pci_resource_start(pdev, i),
                        pci_resource_len(pdev, i));
        }

        return ret;
}

static int
net2272_rdk2_probe(struct pci_dev *pdev, struct net2272 *dev)
{
        unsigned long resource, len;
        void __iomem *mem_mapped_addr[2];
        int ret, i;

        /*
         * BAR 0 holds FGPA config registers
         * BAR 1 holds NET2272 registers
         */

        /* Find and map all address spaces, bar2-3 unused in rdk 2 */
        for (i = 0; i < 2; ++i) {
                resource = pci_resource_start(pdev, i);
                len = pci_resource_len(pdev, i);

                if (!request_mem_region(resource, len, driver_name)) {
                        dev_dbg(dev->dev, "controller already in use\n");
                        ret = -EBUSY;
                        goto err;
                }

                mem_mapped_addr[i] = ioremap(resource, len);
                if (mem_mapped_addr[i] == NULL) {
                        release_mem_region(resource, len);
                        dev_dbg(dev->dev, "can't map memory\n");
                        ret = -EFAULT;
                        goto err;
                }
        }

        dev->rdk2.fpga_base_addr = mem_mapped_addr[0];
        dev->base_addr = mem_mapped_addr[1];

        mb();
        /* Set 2272 bus width (16 bits) and reset */
        writel((1 << CHIP_RESET), dev->rdk2.fpga_base_addr + RDK2_LOCCTLRDK);
        udelay(200);
        writel((1 << BUS_WIDTH), dev->rdk2.fpga_base_addr + RDK2_LOCCTLRDK);
        /* Print fpga version number */
        dev_info(dev->dev, "RDK2 FPGA version %08x\n",
                readl(dev->rdk2.fpga_base_addr + RDK2_FPGAREV));
        /* Enable FPGA Interrupts */
        writel((1 << NET2272_PCI_IRQ), dev->rdk2.fpga_base_addr + RDK2_IRQENB);

        return 0;

 err:
        while (--i >= 0) {
                iounmap(mem_mapped_addr[i]);
                release_mem_region(pci_resource_start(pdev, i),
                        pci_resource_len(pdev, i));
        }

        return ret;
}

static int
net2272_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
        struct net2272 *dev;
        int ret;

        dev = net2272_probe_init(&pdev->dev, pdev->irq);
        if (IS_ERR(dev))
                return PTR_ERR(dev);
        dev->dev_id = pdev->device;

        if (pci_enable_device(pdev) < 0) {
                ret = -ENODEV;
                goto err_free;
        }

        pci_set_master(pdev);

        switch (pdev->device) {
        case PCI_DEVICE_ID_RDK1: ret = net2272_rdk1_probe(pdev, dev); break;
        case PCI_DEVICE_ID_RDK2: ret = net2272_rdk2_probe(pdev, dev); break;
        default: BUG();
        }
        if (ret)
                goto err_pci;

        ret = net2272_probe_fin(dev, 0);
        if (ret)
                goto err_pci;

        pci_set_drvdata(pdev, dev);

        return 0;

 err_pci:
        pci_disable_device(pdev);
 err_free:
        kfree(dev);

        return ret;
}

static void
net2272_rdk1_remove(struct pci_dev *pdev, struct net2272 *dev)
{
        int i;

        /* disable PLX 9054 interrupts */
        writel(readl(dev->rdk1.plx9054_base_addr + INTCSR) &
                ~(1 << PCI_INTERRUPT_ENABLE),
                dev->rdk1.plx9054_base_addr + INTCSR);

        /* clean up resources allocated during probe() */
        iounmap(dev->rdk1.plx9054_base_addr);
        iounmap(dev->rdk1.epld_base_addr);

        for (i = 0; i < 4; ++i) {
                if (i == 1)
                        continue;       /* BAR1 unused */
                release_mem_region(pci_resource_start(pdev, i),
                        pci_resource_len(pdev, i));
        }
}

static void
net2272_rdk2_remove(struct pci_dev *pdev, struct net2272 *dev)
{
        int i;

        /* disable fpga interrupts
        writel(readl(dev->rdk1.plx9054_base_addr + INTCSR) &
                        ~(1 << PCI_INTERRUPT_ENABLE),
                        dev->rdk1.plx9054_base_addr + INTCSR);
        */

        /* clean up resources allocated during probe() */
        iounmap(dev->rdk2.fpga_base_addr);

        for (i = 0; i < 2; ++i)
                release_mem_region(pci_resource_start(pdev, i),
                        pci_resource_len(pdev, i));
}

static void
net2272_pci_remove(struct pci_dev *pdev)
{
        struct net2272 *dev = pci_get_drvdata(pdev);

        net2272_remove(dev);

        switch (pdev->device) {
        case PCI_DEVICE_ID_RDK1: net2272_rdk1_remove(pdev, dev); break;
        case PCI_DEVICE_ID_RDK2: net2272_rdk2_remove(pdev, dev); break;
        default: BUG();
        }

        pci_disable_device(pdev);

        kfree(dev);
}

/* Table of matching PCI IDs */
static struct pci_device_id pci_ids[] = {
        {       /* RDK 1 card */
                .class       = ((PCI_CLASS_BRIDGE_OTHER << 8) | 0xfe),
                .class_mask  = 0,
                .vendor      = PCI_VENDOR_ID_PLX,
                .device      = PCI_DEVICE_ID_RDK1,
                .subvendor   = PCI_ANY_ID,
                .subdevice   = PCI_ANY_ID,
        },
        {       /* RDK 2 card */
                .class       = ((PCI_CLASS_BRIDGE_OTHER << 8) | 0xfe),
                .class_mask  = 0,
                .vendor      = PCI_VENDOR_ID_PLX,
                .device      = PCI_DEVICE_ID_RDK2,
                .subvendor   = PCI_ANY_ID,
                .subdevice   = PCI_ANY_ID,
        },
        { }
};
MODULE_DEVICE_TABLE(pci, pci_ids);

static struct pci_driver net2272_pci_driver = {
        .name     = driver_name,
        .id_table = pci_ids,

        .probe    = net2272_pci_probe,
        .remove   = net2272_pci_remove,
};

static int net2272_pci_register(void)
{
        return pci_register_driver(&net2272_pci_driver);
}

static void net2272_pci_unregister(void)
{
        pci_unregister_driver(&net2272_pci_driver);
}

#else
static inline int net2272_pci_register(void) { return 0; }
static inline void net2272_pci_unregister(void) { }
#endif

/*---------------------------------------------------------------------------*/

static int
net2272_plat_probe(struct platform_device *pdev)
{
        struct net2272 *dev;
        int ret;
        unsigned int irqflags;
        resource_size_t base, len;
        struct resource *iomem, *iomem_bus, *irq_res;

        irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        iomem_bus = platform_get_resource(pdev, IORESOURCE_BUS, 0);
        if (!irq_res || !iomem) {
                dev_err(&pdev->dev, "must provide irq/base addr");
                return -EINVAL;
        }

        dev = net2272_probe_init(&pdev->dev, irq_res->start);
        if (IS_ERR(dev))
                return PTR_ERR(dev);

        irqflags = 0;
        if (irq_res->flags & IORESOURCE_IRQ_HIGHEDGE)
                irqflags |= IRQF_TRIGGER_RISING;
        if (irq_res->flags & IORESOURCE_IRQ_LOWEDGE)
                irqflags |= IRQF_TRIGGER_FALLING;
        if (irq_res->flags & IORESOURCE_IRQ_HIGHLEVEL)
                irqflags |= IRQF_TRIGGER_HIGH;
        if (irq_res->flags & IORESOURCE_IRQ_LOWLEVEL)
                irqflags |= IRQF_TRIGGER_LOW;

        base = iomem->start;
        len = resource_size(iomem);
        if (iomem_bus)
                dev->base_shift = iomem_bus->start;

        if (!request_mem_region(base, len, driver_name)) {
                dev_dbg(dev->dev, "get request memory region!\n");
                ret = -EBUSY;
                goto err;
        }
        dev->base_addr = ioremap(base, len);
        if (!dev->base_addr) {
                dev_dbg(dev->dev, "can't map memory\n");
                ret = -EFAULT;
                goto err_req;
        }

        ret = net2272_probe_fin(dev, IRQF_TRIGGER_LOW);
        if (ret)
                goto err_io;

        platform_set_drvdata(pdev, dev);
        dev_info(&pdev->dev, "running in 16-bit, %sbyte swap local bus mode\n",
                (net2272_read(dev, LOCCTL) & (1 << BYTE_SWAP)) ? "" : "no ");

        return 0;

 err_io:
        iounmap(dev->base_addr);
 err_req:
        release_mem_region(base, len);
 err:
        kfree(dev);

        return ret;
}

static int
net2272_plat_remove(struct platform_device *pdev)
{
        struct net2272 *dev = platform_get_drvdata(pdev);

        net2272_remove(dev);

        release_mem_region(pdev->resource[0].start,
                resource_size(&pdev->resource[0]));

        kfree(dev);

        return 0;
}

static struct platform_driver net2272_plat_driver = {
        .probe   = net2272_plat_probe,
        .remove  = net2272_plat_remove,
        .driver  = {
                .name  = driver_name,
        },
        /* FIXME .suspend, .resume */
};
MODULE_ALIAS("platform:net2272");

static int __init net2272_init(void)
{
        int ret;

        ret = net2272_pci_register();
        if (ret)
                return ret;
        ret = platform_driver_register(&net2272_plat_driver);
        if (ret)
                goto err_pci;
        return ret;

err_pci:
        net2272_pci_unregister();
        return ret;
}
module_init(net2272_init);

static void __exit net2272_cleanup(void)
{
        net2272_pci_unregister();
        platform_driver_unregister(&net2272_plat_driver);
}
module_exit(net2272_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("PLX Technology, Inc.");
MODULE_LICENSE("GPL");