Archipelago » qemu

/*

 * "Inventra" High-speed Dual-Role Controller (MUSB-HDRC), Mentor Graphics,

 * USB2.0 OTG compliant core used in various chips.

 *

 * Copyright (C) 2008 Nokia Corporation

 * Written by Andrzej Zaborowski <andrew@openedhand.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 or

 * (at your option) version 3 of the License.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, see <http://www.gnu.org/licenses/>.

 *

 * Only host-mode and non-DMA accesses are currently supported.

 */

#include "qemu-common.h"

#include "qemu-timer.h"

#include "usb.h"

#include "irq.h"

#include "hw.h"

/* Common USB registers */

#define MUSB_HDRC_FADDR                0x00        /* 8-bit */

#define MUSB_HDRC_POWER                0x01        /* 8-bit */

#define MUSB_HDRC_INTRTX        0x02        /* 16-bit */

#define MUSB_HDRC_INTRRX        0x04

#define MUSB_HDRC_INTRTXE        0x06  

#define MUSB_HDRC_INTRRXE        0x08  

#define MUSB_HDRC_INTRUSB        0x0a        /* 8 bit */

#define MUSB_HDRC_INTRUSBE        0x0b        /* 8 bit */

#define MUSB_HDRC_FRAME                0x0c        /* 16-bit */

#define MUSB_HDRC_INDEX                0x0e        /* 8 bit */

#define MUSB_HDRC_TESTMODE        0x0f        /* 8 bit */

/* Per-EP registers in indexed mode */

#define MUSB_HDRC_EP_IDX        0x10        /* 8-bit */

/* EP FIFOs */

#define MUSB_HDRC_FIFO                0x20

/* Additional Control Registers */

#define        MUSB_HDRC_DEVCTL        0x60        /* 8 bit */

/* These are indexed */

#define MUSB_HDRC_TXFIFOSZ        0x62        /* 8 bit (see masks) */

#define MUSB_HDRC_RXFIFOSZ        0x63        /* 8 bit (see masks) */

#define MUSB_HDRC_TXFIFOADDR        0x64        /* 16 bit offset shifted right 3 */

#define MUSB_HDRC_RXFIFOADDR        0x66        /* 16 bit offset shifted right 3 */

/* Some more registers */

#define MUSB_HDRC_VCTRL                0x68        /* 8 bit */

#define MUSB_HDRC_HWVERS        0x6c        /* 8 bit */

/* Added in HDRC 1.9(?) & MHDRC 1.4 */

/* ULPI pass-through */

#define MUSB_HDRC_ULPI_VBUSCTL        0x70

#define MUSB_HDRC_ULPI_REGDATA        0x74

#define MUSB_HDRC_ULPI_REGADDR        0x75

#define MUSB_HDRC_ULPI_REGCTL        0x76

/* Extended config & PHY control */

#define MUSB_HDRC_ENDCOUNT        0x78        /* 8 bit */

#define MUSB_HDRC_DMARAMCFG        0x79        /* 8 bit */

#define MUSB_HDRC_PHYWAIT        0x7a        /* 8 bit */

#define MUSB_HDRC_PHYVPLEN        0x7b        /* 8 bit */

#define MUSB_HDRC_HS_EOF1        0x7c        /* 8 bit, units of 546.1 us */

#define MUSB_HDRC_FS_EOF1        0x7d        /* 8 bit, units of 533.3 ns */

#define MUSB_HDRC_LS_EOF1        0x7e        /* 8 bit, units of 1.067 us */

/* Per-EP BUSCTL registers */

#define MUSB_HDRC_BUSCTL        0x80

/* Per-EP registers in flat mode */

#define MUSB_HDRC_EP                0x100

/* offsets to registers in flat model */

#define MUSB_HDRC_TXMAXP        0x00        /* 16 bit apparently */

#define MUSB_HDRC_TXCSR                0x02        /* 16 bit apparently */

#define MUSB_HDRC_CSR0                MUSB_HDRC_TXCSR                /* re-used for EP0 */

#define MUSB_HDRC_RXMAXP        0x04        /* 16 bit apparently */

#define MUSB_HDRC_RXCSR                0x06        /* 16 bit apparently */

#define MUSB_HDRC_RXCOUNT        0x08        /* 16 bit apparently */

#define MUSB_HDRC_COUNT0        MUSB_HDRC_RXCOUNT        /* re-used for EP0 */

#define MUSB_HDRC_TXTYPE        0x0a        /* 8 bit apparently */

#define MUSB_HDRC_TYPE0                MUSB_HDRC_TXTYPE        /* re-used for EP0 */

#define MUSB_HDRC_TXINTERVAL        0x0b        /* 8 bit apparently */

#define MUSB_HDRC_NAKLIMIT0        MUSB_HDRC_TXINTERVAL        /* re-used for EP0 */

#define MUSB_HDRC_RXTYPE        0x0c        /* 8 bit apparently */

#define MUSB_HDRC_RXINTERVAL        0x0d        /* 8 bit apparently */

#define MUSB_HDRC_FIFOSIZE        0x0f        /* 8 bit apparently */

#define MUSB_HDRC_CONFIGDATA        MGC_O_HDRC_FIFOSIZE        /* re-used for EP0 */

/* "Bus control" registers */

#define MUSB_HDRC_TXFUNCADDR        0x00

#define MUSB_HDRC_TXHUBADDR        0x02

#define MUSB_HDRC_TXHUBPORT        0x03

#define MUSB_HDRC_RXFUNCADDR        0x04

#define MUSB_HDRC_RXHUBADDR        0x06

#define MUSB_HDRC_RXHUBPORT        0x07

/*

 * MUSBHDRC Register bit masks

 */

/* POWER */

#define MGC_M_POWER_ISOUPDATE                0x80 

#define        MGC_M_POWER_SOFTCONN                0x40

#define        MGC_M_POWER_HSENAB                0x20

#define        MGC_M_POWER_HSMODE                0x10

#define MGC_M_POWER_RESET                0x08

#define MGC_M_POWER_RESUME                0x04

#define MGC_M_POWER_SUSPENDM                0x02

#define MGC_M_POWER_ENSUSPEND                0x01

/* INTRUSB */

#define MGC_M_INTR_SUSPEND                0x01

#define MGC_M_INTR_RESUME                0x02

#define MGC_M_INTR_RESET                0x04

#define MGC_M_INTR_BABBLE                0x04

#define MGC_M_INTR_SOF                        0x08 

#define MGC_M_INTR_CONNECT                0x10

#define MGC_M_INTR_DISCONNECT                0x20

#define MGC_M_INTR_SESSREQ                0x40

#define MGC_M_INTR_VBUSERROR                0x80        /* FOR SESSION END */

#define MGC_M_INTR_EP0                        0x01        /* FOR EP0 INTERRUPT */

/* DEVCTL */

#define MGC_M_DEVCTL_BDEVICE                0x80   

#define MGC_M_DEVCTL_FSDEV                0x40

#define MGC_M_DEVCTL_LSDEV                0x20

#define MGC_M_DEVCTL_VBUS                0x18

#define MGC_S_DEVCTL_VBUS                3

#define MGC_M_DEVCTL_HM                        0x04

#define MGC_M_DEVCTL_HR                        0x02

#define MGC_M_DEVCTL_SESSION                0x01

/* TESTMODE */

#define MGC_M_TEST_FORCE_HOST                0x80

#define MGC_M_TEST_FIFO_ACCESS                0x40

#define MGC_M_TEST_FORCE_FS                0x20

#define MGC_M_TEST_FORCE_HS                0x10

#define MGC_M_TEST_PACKET                0x08

#define MGC_M_TEST_K                        0x04

#define MGC_M_TEST_J                        0x02

#define MGC_M_TEST_SE0_NAK                0x01

/* CSR0 */

#define        MGC_M_CSR0_FLUSHFIFO                0x0100

#define MGC_M_CSR0_TXPKTRDY                0x0002

#define MGC_M_CSR0_RXPKTRDY                0x0001

/* CSR0 in Peripheral mode */

#define MGC_M_CSR0_P_SVDSETUPEND        0x0080

#define MGC_M_CSR0_P_SVDRXPKTRDY        0x0040

#define MGC_M_CSR0_P_SENDSTALL                0x0020

#define MGC_M_CSR0_P_SETUPEND                0x0010

#define MGC_M_CSR0_P_DATAEND                0x0008

#define MGC_M_CSR0_P_SENTSTALL                0x0004

/* CSR0 in Host mode */

#define MGC_M_CSR0_H_NO_PING                0x0800

#define MGC_M_CSR0_H_WR_DATATOGGLE        0x0400        /* set to allow setting: */

#define MGC_M_CSR0_H_DATATOGGLE                0x0200        /* data toggle control */

#define        MGC_M_CSR0_H_NAKTIMEOUT                0x0080

#define MGC_M_CSR0_H_STATUSPKT                0x0040

#define MGC_M_CSR0_H_REQPKT                0x0020

#define MGC_M_CSR0_H_ERROR                0x0010

#define MGC_M_CSR0_H_SETUPPKT                0x0008

#define MGC_M_CSR0_H_RXSTALL                0x0004

/* CONFIGDATA */

#define MGC_M_CONFIGDATA_MPRXE                0x80        /* auto bulk pkt combining */

#define MGC_M_CONFIGDATA_MPTXE                0x40        /* auto bulk pkt splitting */

#define MGC_M_CONFIGDATA_BIGENDIAN        0x20

#define MGC_M_CONFIGDATA_HBRXE                0x10        /* HB-ISO for RX */

#define MGC_M_CONFIGDATA_HBTXE                0x08        /* HB-ISO for TX */

#define MGC_M_CONFIGDATA_DYNFIFO        0x04        /* dynamic FIFO sizing */

#define MGC_M_CONFIGDATA_SOFTCONE        0x02        /* SoftConnect */

#define MGC_M_CONFIGDATA_UTMIDW                0x01        /* Width, 0 => 8b, 1 => 16b */

/* TXCSR in Peripheral and Host mode */

#define MGC_M_TXCSR_AUTOSET                0x8000

#define MGC_M_TXCSR_ISO                        0x4000

#define MGC_M_TXCSR_MODE                0x2000

#define MGC_M_TXCSR_DMAENAB                0x1000

#define MGC_M_TXCSR_FRCDATATOG                0x0800

#define MGC_M_TXCSR_DMAMODE                0x0400

#define MGC_M_TXCSR_CLRDATATOG                0x0040

#define MGC_M_TXCSR_FLUSHFIFO                0x0008

#define MGC_M_TXCSR_FIFONOTEMPTY        0x0002

#define MGC_M_TXCSR_TXPKTRDY                0x0001

/* TXCSR in Peripheral mode */

#define MGC_M_TXCSR_P_INCOMPTX                0x0080

#define MGC_M_TXCSR_P_SENTSTALL                0x0020

#define MGC_M_TXCSR_P_SENDSTALL                0x0010

#define MGC_M_TXCSR_P_UNDERRUN                0x0004

/* TXCSR in Host mode */

#define MGC_M_TXCSR_H_WR_DATATOGGLE        0x0200

#define MGC_M_TXCSR_H_DATATOGGLE        0x0100

#define MGC_M_TXCSR_H_NAKTIMEOUT        0x0080

#define MGC_M_TXCSR_H_RXSTALL                0x0020

#define MGC_M_TXCSR_H_ERROR                0x0004

/* RXCSR in Peripheral and Host mode */

#define MGC_M_RXCSR_AUTOCLEAR                0x8000

#define MGC_M_RXCSR_DMAENAB                0x2000

#define MGC_M_RXCSR_DISNYET                0x1000

#define MGC_M_RXCSR_DMAMODE                0x0800

#define MGC_M_RXCSR_INCOMPRX                0x0100

#define MGC_M_RXCSR_CLRDATATOG                0x0080

#define MGC_M_RXCSR_FLUSHFIFO                0x0010

#define MGC_M_RXCSR_DATAERROR                0x0008

#define MGC_M_RXCSR_FIFOFULL                0x0002

#define MGC_M_RXCSR_RXPKTRDY                0x0001

/* RXCSR in Peripheral mode */

#define MGC_M_RXCSR_P_ISO                0x4000

#define MGC_M_RXCSR_P_SENTSTALL                0x0040

#define MGC_M_RXCSR_P_SENDSTALL                0x0020

#define MGC_M_RXCSR_P_OVERRUN                0x0004

/* RXCSR in Host mode */

#define MGC_M_RXCSR_H_AUTOREQ                0x4000

#define MGC_M_RXCSR_H_WR_DATATOGGLE        0x0400

#define MGC_M_RXCSR_H_DATATOGGLE        0x0200

#define MGC_M_RXCSR_H_RXSTALL                0x0040

#define MGC_M_RXCSR_H_REQPKT                0x0020

#define MGC_M_RXCSR_H_ERROR                0x0004

/* HUBADDR */

#define MGC_M_HUBADDR_MULTI_TT                0x80

/* ULPI: Added in HDRC 1.9(?) & MHDRC 1.4 */

#define MGC_M_ULPI_VBCTL_USEEXTVBUSIND        0x02

#define MGC_M_ULPI_VBCTL_USEEXTVBUS        0x01

#define MGC_M_ULPI_REGCTL_INT_ENABLE        0x08

#define MGC_M_ULPI_REGCTL_READNOTWRITE        0x04

#define MGC_M_ULPI_REGCTL_COMPLETE        0x02

#define MGC_M_ULPI_REGCTL_REG                0x01

/* #define MUSB_DEBUG */

#ifdef MUSB_DEBUG

#define TRACE(fmt,...) fprintf(stderr, "%s@%d: " fmt "\n", __FUNCTION__, \

                               __LINE__, ##__VA_ARGS__)

#else

#define TRACE(...)

#endif

static void musb_attach(USBPort *port);

static void musb_detach(USBPort *port);

static void musb_child_detach(USBPort *port, USBDevice *child);

static void musb_schedule_cb(USBPort *port, USBPacket *p);

static void musb_async_cancel_device(MUSBState *s, USBDevice *dev);

static USBPortOps musb_port_ops = {

    .attach = musb_attach,

    .detach = musb_detach,

    .child_detach = musb_child_detach,

    .complete = musb_schedule_cb,

};

static USBBusOps musb_bus_ops = {

};

typedef struct MUSBPacket MUSBPacket;

typedef struct MUSBEndPoint MUSBEndPoint;

struct MUSBPacket {

    USBPacket p;

    MUSBEndPoint *ep;

    int dir;

};

struct MUSBEndPoint {

    uint16_t faddr[2];

    uint8_t haddr[2];

    uint8_t hport[2];

    uint16_t csr[2];

    uint16_t maxp[2];

    uint16_t rxcount;

    uint8_t type[2];

    uint8_t interval[2];

    uint8_t config;

    uint8_t fifosize;

    int timeout[2];        /* Always in microframes */

    uint8_t *buf[2];

    int fifolen[2];

    int fifostart[2];

    int fifoaddr[2];

    MUSBPacket packey[2];

    int status[2];

    int ext_size[2];

    /* For callbacks' use */

    int epnum;

    int interrupt[2];

    MUSBState *musb;

    USBCallback *delayed_cb[2];

    QEMUTimer *intv_timer[2];

};

struct MUSBState {

    qemu_irq *irqs;

    USBBus bus;

    USBPort port;

    int idx;

    uint8_t devctl;

    uint8_t power;

    uint8_t faddr;

    uint8_t intr;

    uint8_t mask;

    uint16_t tx_intr;

    uint16_t tx_mask;

    uint16_t rx_intr;

    uint16_t rx_mask;

    int setup_len;

    int session;

    uint8_t buf[0x8000];

        /* Duplicating the world since 2008!...  probably we should have 32

         * logical, single endpoints instead.  */

    MUSBEndPoint ep[16];

};

struct MUSBState *musb_init(qemu_irq *irqs)

{

    MUSBState *s = qemu_mallocz(sizeof(*s));

    int i;

    s->irqs = irqs;

    s->faddr = 0x00;

    s->power = MGC_M_POWER_HSENAB;

    s->tx_intr = 0x0000;

    s->rx_intr = 0x0000;

    s->tx_mask = 0xffff;

    s->rx_mask = 0xffff;

    s->intr = 0x00;

    s->mask = 0x06;

    s->idx = 0;

    /* TODO: _DW */

    s->ep[0].config = MGC_M_CONFIGDATA_SOFTCONE | MGC_M_CONFIGDATA_DYNFIFO;

    for (i = 0; i < 16; i ++) {

        s->ep[i].fifosize = 64;

        s->ep[i].maxp[0] = 0x40;

        s->ep[i].maxp[1] = 0x40;

        s->ep[i].musb = s;

        s->ep[i].epnum = i;

    }

    usb_bus_new(&s->bus, &musb_bus_ops, NULL /* FIXME */);

    usb_register_port(&s->bus, &s->port, s, 0, &musb_port_ops,

                      USB_SPEED_MASK_LOW | USB_SPEED_MASK_FULL);

    return s;

}

static void musb_vbus_set(MUSBState *s, int level)

{

    if (level)

        s->devctl |= 3 << MGC_S_DEVCTL_VBUS;

    else

        s->devctl &= ~MGC_M_DEVCTL_VBUS;

    qemu_set_irq(s->irqs[musb_set_vbus], level);

}

static void musb_intr_set(MUSBState *s, int line, int level)

{

    if (!level) {

        s->intr &= ~(1 << line);

        qemu_irq_lower(s->irqs[line]);

    } else if (s->mask & (1 << line)) {

        s->intr |= 1 << line;

        qemu_irq_raise(s->irqs[line]);

    }

}

static void musb_tx_intr_set(MUSBState *s, int line, int level)

{

    if (!level) {

        s->tx_intr &= ~(1 << line);

        if (!s->tx_intr)

            qemu_irq_lower(s->irqs[musb_irq_tx]);

    } else if (s->tx_mask & (1 << line)) {

        s->tx_intr |= 1 << line;

        qemu_irq_raise(s->irqs[musb_irq_tx]);

    }

}

static void musb_rx_intr_set(MUSBState *s, int line, int level)

{

    if (line) {

        if (!level) {

            s->rx_intr &= ~(1 << line);

            if (!s->rx_intr)

                qemu_irq_lower(s->irqs[musb_irq_rx]);

        } else if (s->rx_mask & (1 << line)) {

            s->rx_intr |= 1 << line;

            qemu_irq_raise(s->irqs[musb_irq_rx]);

        }

    } else

        musb_tx_intr_set(s, line, level);

}

uint32_t musb_core_intr_get(MUSBState *s)

{

    return (s->rx_intr << 15) | s->tx_intr;

}

void musb_core_intr_clear(MUSBState *s, uint32_t mask)

{

    if (s->rx_intr) {

        s->rx_intr &= mask >> 15;

        if (!s->rx_intr)

            qemu_irq_lower(s->irqs[musb_irq_rx]);

    }

    if (s->tx_intr) {

        s->tx_intr &= mask & 0xffff;

        if (!s->tx_intr)

            qemu_irq_lower(s->irqs[musb_irq_tx]);

    }

}

void musb_set_size(MUSBState *s, int epnum, int size, int is_tx)

{

    s->ep[epnum].ext_size[!is_tx] = size;

    s->ep[epnum].fifostart[0] = 0;

    s->ep[epnum].fifostart[1] = 0;

    s->ep[epnum].fifolen[0] = 0;

    s->ep[epnum].fifolen[1] = 0;

}

static void musb_session_update(MUSBState *s, int prev_dev, int prev_sess)

{

    int detect_prev = prev_dev && prev_sess;

    int detect = !!s->port.dev && s->session;

    if (detect && !detect_prev) {

        /* Let's skip the ID pin sense and VBUS sense formalities and

         * and signal a successful SRP directly.  This should work at least

         * for the Linux driver stack.  */

        musb_intr_set(s, musb_irq_connect, 1);

        if (s->port.dev->speed == USB_SPEED_LOW) {

            s->devctl &= ~MGC_M_DEVCTL_FSDEV;

            s->devctl |= MGC_M_DEVCTL_LSDEV;

        } else {

            s->devctl |= MGC_M_DEVCTL_FSDEV;

            s->devctl &= ~MGC_M_DEVCTL_LSDEV;

        }

        /* A-mode?  */

        s->devctl &= ~MGC_M_DEVCTL_BDEVICE;

        /* Host-mode bit?  */

        s->devctl |= MGC_M_DEVCTL_HM;

#if 1

        musb_vbus_set(s, 1);

#endif

    } else if (!detect && detect_prev) {

#if 1

        musb_vbus_set(s, 0);

#endif

    }

}

/* Attach or detach a device on our only port.  */

static void musb_attach(USBPort *port)

{

    MUSBState *s = (MUSBState *) port->opaque;

    musb_intr_set(s, musb_irq_vbus_request, 1);

    musb_session_update(s, 0, s->session);

}

static void musb_detach(USBPort *port)

{

    MUSBState *s = (MUSBState *) port->opaque;

    musb_async_cancel_device(s, port->dev);

    musb_intr_set(s, musb_irq_disconnect, 1);

    musb_session_update(s, 1, s->session);

}

static void musb_child_detach(USBPort *port, USBDevice *child)

{

    MUSBState *s = (MUSBState *) port->opaque;

    musb_async_cancel_device(s, child);

}

static void musb_cb_tick0(void *opaque)

{

    MUSBEndPoint *ep = (MUSBEndPoint *) opaque;

    ep->delayed_cb[0](&ep->packey[0].p, opaque);

}

static void musb_cb_tick1(void *opaque)

{

    MUSBEndPoint *ep = (MUSBEndPoint *) opaque;

    ep->delayed_cb[1](&ep->packey[1].p, opaque);

}

#define musb_cb_tick        (dir ? musb_cb_tick1 : musb_cb_tick0)

static void musb_schedule_cb(USBPort *port, USBPacket *packey)

{

    MUSBPacket *p = container_of(packey, MUSBPacket, p);

    MUSBEndPoint *ep = p->ep;

    int dir = p->dir;

    int timeout = 0;

    if (ep->status[dir] == USB_RET_NAK)

        timeout = ep->timeout[dir];

    else if (ep->interrupt[dir])

        timeout = 8;

    else

        return musb_cb_tick(ep);

    if (!ep->intv_timer[dir])

        ep->intv_timer[dir] = qemu_new_timer_ns(vm_clock, musb_cb_tick, ep);

    qemu_mod_timer(ep->intv_timer[dir], qemu_get_clock_ns(vm_clock) +

                   muldiv64(timeout, get_ticks_per_sec(), 8000));

}

static int musb_timeout(int ttype, int speed, int val)

{

#if 1

    return val << 3;

#endif

    switch (ttype) {

    case USB_ENDPOINT_XFER_CONTROL:

        if (val < 2)

            return 0;

        else if (speed == USB_SPEED_HIGH)

            return 1 << (val - 1);

        else

            return 8 << (val - 1);

    case USB_ENDPOINT_XFER_INT:

        if (speed == USB_SPEED_HIGH)

            if (val < 2)

                return 0;

            else

                return 1 << (val - 1);

        else

            return val << 3;

    case USB_ENDPOINT_XFER_BULK:

    case USB_ENDPOINT_XFER_ISOC:

        if (val < 2)

            return 0;

        else if (speed == USB_SPEED_HIGH)

            return 1 << (val - 1);

        else

            return 8 << (val - 1);

        /* TODO: what with low-speed Bulk and Isochronous?  */

    }

    hw_error("bad interval\n");

}

static void musb_packet(MUSBState *s, MUSBEndPoint *ep,

                int epnum, int pid, int len, USBCallback cb, int dir)

{

    int ret;

    int idx = epnum && dir;

    int ttype;

    /* ep->type[0,1] contains:

     * in bits 7:6 the speed (0 - invalid, 1 - high, 2 - full, 3 - slow)

     * in bits 5:4 the transfer type (BULK / INT)

     * in bits 3:0 the EP num

     */

    ttype = epnum ? (ep->type[idx] >> 4) & 3 : 0;

    ep->timeout[dir] = musb_timeout(ttype,

                    ep->type[idx] >> 6, ep->interval[idx]);

    ep->interrupt[dir] = ttype == USB_ENDPOINT_XFER_INT;

    ep->delayed_cb[dir] = cb;

    ep->packey[dir].p.pid = pid;

    /* A wild guess on the FADDR semantics... */

    ep->packey[dir].p.devaddr = ep->faddr[idx];

    ep->packey[dir].p.devep = ep->type[idx] & 0xf;

    ep->packey[dir].p.data = (void *) ep->buf[idx];

    ep->packey[dir].p.len = len;

    ep->packey[dir].ep = ep;

    ep->packey[dir].dir = dir;

    if (s->port.dev)

        ret = usb_handle_packet(s->port.dev, &ep->packey[dir].p);

    else

        ret = USB_RET_NODEV;

    if (ret == USB_RET_ASYNC) {

        ep->status[dir] = len;

        return;

    }

    ep->status[dir] = ret;

    musb_schedule_cb(&s->port, &ep->packey[dir].p);

}

static void musb_tx_packet_complete(USBPacket *packey, void *opaque)

{

    /* Unfortunately we can't use packey->devep because that's the remote

     * endpoint number and may be different than our local.  */

    MUSBEndPoint *ep = (MUSBEndPoint *) opaque;

    int epnum = ep->epnum;

    MUSBState *s = ep->musb;

    ep->fifostart[0] = 0;

    ep->fifolen[0] = 0;

#ifdef CLEAR_NAK

    if (ep->status[0] != USB_RET_NAK) {

#endif

        if (epnum)

            ep->csr[0] &= ~(MGC_M_TXCSR_FIFONOTEMPTY | MGC_M_TXCSR_TXPKTRDY);

        else

            ep->csr[0] &= ~MGC_M_CSR0_TXPKTRDY;

#ifdef CLEAR_NAK

    }

#endif

    /* Clear all of the error bits first */

    if (epnum)

        ep->csr[0] &= ~(MGC_M_TXCSR_H_ERROR | MGC_M_TXCSR_H_RXSTALL |

                        MGC_M_TXCSR_H_NAKTIMEOUT);

    else

        ep->csr[0] &= ~(MGC_M_CSR0_H_ERROR | MGC_M_CSR0_H_RXSTALL |

                        MGC_M_CSR0_H_NAKTIMEOUT | MGC_M_CSR0_H_NO_PING);

    if (ep->status[0] == USB_RET_STALL) {

        /* Command not supported by target! */

        ep->status[0] = 0;

        if (epnum)

            ep->csr[0] |= MGC_M_TXCSR_H_RXSTALL;

        else

            ep->csr[0] |= MGC_M_CSR0_H_RXSTALL;

    }

    if (ep->status[0] == USB_RET_NAK) {

        ep->status[0] = 0;

        /* NAK timeouts are only generated in Bulk transfers and

         * Data-errors in Isochronous.  */

        if (ep->interrupt[0]) {

            return;

        }

        if (epnum)

            ep->csr[0] |= MGC_M_TXCSR_H_NAKTIMEOUT;

        else

            ep->csr[0] |= MGC_M_CSR0_H_NAKTIMEOUT;

    }

    if (ep->status[0] < 0) {

        if (ep->status[0] == USB_RET_BABBLE)

            musb_intr_set(s, musb_irq_rst_babble, 1);

        /* Pretend we've tried three times already and failed (in

         * case of USB_TOKEN_SETUP).  */

        if (epnum)

            ep->csr[0] |= MGC_M_TXCSR_H_ERROR;

        else

            ep->csr[0] |= MGC_M_CSR0_H_ERROR;

        musb_tx_intr_set(s, epnum, 1);

        return;

    }

    /* TODO: check len for over/underruns of an OUT packet?  */

#ifdef SETUPLEN_HACK

    if (!epnum && ep->packey[0].pid == USB_TOKEN_SETUP)

        s->setup_len = ep->packey[0].data[6];

#endif

    /* In DMA mode: if no error, assert DMA request for this EP,

     * and skip the interrupt.  */

    musb_tx_intr_set(s, epnum, 1);

}

static void musb_rx_packet_complete(USBPacket *packey, void *opaque)

{

    /* Unfortunately we can't use packey->devep because that's the remote

     * endpoint number and may be different than our local.  */

    MUSBEndPoint *ep = (MUSBEndPoint *) opaque;

    int epnum = ep->epnum;

    MUSBState *s = ep->musb;

    ep->fifostart[1] = 0;

    ep->fifolen[1] = 0;

#ifdef CLEAR_NAK

    if (ep->status[1] != USB_RET_NAK) {

#endif

        ep->csr[1] &= ~MGC_M_RXCSR_H_REQPKT;

        if (!epnum)

            ep->csr[0] &= ~MGC_M_CSR0_H_REQPKT;

#ifdef CLEAR_NAK

    }

#endif

    /* Clear all of the imaginable error bits first */

    ep->csr[1] &= ~(MGC_M_RXCSR_H_ERROR | MGC_M_RXCSR_H_RXSTALL |

                    MGC_M_RXCSR_DATAERROR);

    if (!epnum)

        ep->csr[0] &= ~(MGC_M_CSR0_H_ERROR | MGC_M_CSR0_H_RXSTALL |

                        MGC_M_CSR0_H_NAKTIMEOUT | MGC_M_CSR0_H_NO_PING);

    if (ep->status[1] == USB_RET_STALL) {

        ep->status[1] = 0;

        packey->len = 0;

        ep->csr[1] |= MGC_M_RXCSR_H_RXSTALL;

        if (!epnum)

            ep->csr[0] |= MGC_M_CSR0_H_RXSTALL;

    }

    if (ep->status[1] == USB_RET_NAK) {

        ep->status[1] = 0;

        /* NAK timeouts are only generated in Bulk transfers and

         * Data-errors in Isochronous.  */

        if (ep->interrupt[1])

            return musb_packet(s, ep, epnum, USB_TOKEN_IN,

                            packey->len, musb_rx_packet_complete, 1);

        ep->csr[1] |= MGC_M_RXCSR_DATAERROR;

        if (!epnum)

            ep->csr[0] |= MGC_M_CSR0_H_NAKTIMEOUT;

    }

    if (ep->status[1] < 0) {

        if (ep->status[1] == USB_RET_BABBLE) {

            musb_intr_set(s, musb_irq_rst_babble, 1);

            return;

        }

        /* Pretend we've tried three times already and failed (in

         * case of a control transfer).  */

        ep->csr[1] |= MGC_M_RXCSR_H_ERROR;

        if (!epnum)

            ep->csr[0] |= MGC_M_CSR0_H_ERROR;

        musb_rx_intr_set(s, epnum, 1);

        return;

    }

    /* TODO: check len for over/underruns of an OUT packet?  */

    /* TODO: perhaps make use of e->ext_size[1] here.  */

    packey->len = ep->status[1];

    if (!(ep->csr[1] & (MGC_M_RXCSR_H_RXSTALL | MGC_M_RXCSR_DATAERROR))) {

        ep->csr[1] |= MGC_M_RXCSR_FIFOFULL | MGC_M_RXCSR_RXPKTRDY;

        if (!epnum)

            ep->csr[0] |= MGC_M_CSR0_RXPKTRDY;

        ep->rxcount = packey->len; /* XXX: MIN(packey->len, ep->maxp[1]); */

        /* In DMA mode: assert DMA request for this EP */

    }

    /* Only if DMA has not been asserted */

    musb_rx_intr_set(s, epnum, 1);

}

static void musb_async_cancel_device(MUSBState *s, USBDevice *dev)

{

    int ep, dir;

    for (ep = 0; ep < 16; ep++) {

        for (dir = 0; dir < 2; dir++) {

            if (s->ep[ep].packey[dir].p.owner != dev) {

                continue;

            }

            usb_cancel_packet(&s->ep[ep].packey[dir].p);

            /* status updates needed here? */

        }

    }

}

static void musb_tx_rdy(MUSBState *s, int epnum)

{

    MUSBEndPoint *ep = s->ep + epnum;

    int pid;

    int total, valid = 0;

    TRACE("start %d, len %d",  ep->fifostart[0], ep->fifolen[0] );

    ep->fifostart[0] += ep->fifolen[0];

    ep->fifolen[0] = 0;

    /* XXX: how's the total size of the packet retrieved exactly in

     * the generic case?  */

    total = ep->maxp[0] & 0x3ff;

    if (ep->ext_size[0]) {

        total = ep->ext_size[0];

        ep->ext_size[0] = 0;

        valid = 1;

    }

    /* If the packet is not fully ready yet, wait for a next segment.  */

    if (epnum && (ep->fifostart[0]) < total)

        return;

    if (!valid)

        total = ep->fifostart[0];

    pid = USB_TOKEN_OUT;

    if (!epnum && (ep->csr[0] & MGC_M_CSR0_H_SETUPPKT)) {

        pid = USB_TOKEN_SETUP;

        if (total != 8) {

            TRACE("illegal SETUPPKT length of %i bytes", total);

        }

        /* Controller should retry SETUP packets three times on errors

         * but it doesn't make sense for us to do that.  */

    }

    return musb_packet(s, ep, epnum, pid,

                    total, musb_tx_packet_complete, 0);

}

static void musb_rx_req(MUSBState *s, int epnum)

{

    MUSBEndPoint *ep = s->ep + epnum;

    int total;

    /* If we already have a packet, which didn't fit into the

     * 64 bytes of the FIFO, only move the FIFO start and return. (Obsolete) */

    if (ep->packey[1].p.pid == USB_TOKEN_IN && ep->status[1] >= 0 &&

                    (ep->fifostart[1]) + ep->rxcount <

                    ep->packey[1].p.len) {

        TRACE("0x%08x, %d",  ep->fifostart[1], ep->rxcount );

        ep->fifostart[1] += ep->rxcount;

        ep->fifolen[1] = 0;

        ep->rxcount = MIN(ep->packey[0].p.len - (ep->fifostart[1]),

                        ep->maxp[1]);

        ep->csr[1] &= ~MGC_M_RXCSR_H_REQPKT;

        if (!epnum)

            ep->csr[0] &= ~MGC_M_CSR0_H_REQPKT;

        /* Clear all of the error bits first */

        ep->csr[1] &= ~(MGC_M_RXCSR_H_ERROR | MGC_M_RXCSR_H_RXSTALL |

                        MGC_M_RXCSR_DATAERROR);

        if (!epnum)

            ep->csr[0] &= ~(MGC_M_CSR0_H_ERROR | MGC_M_CSR0_H_RXSTALL |

                            MGC_M_CSR0_H_NAKTIMEOUT | MGC_M_CSR0_H_NO_PING);

        ep->csr[1] |= MGC_M_RXCSR_FIFOFULL | MGC_M_RXCSR_RXPKTRDY;

        if (!epnum)

            ep->csr[0] |= MGC_M_CSR0_RXPKTRDY;

        musb_rx_intr_set(s, epnum, 1);

        return;

    }

    /* The driver sets maxp[1] to 64 or less because it knows the hardware

     * FIFO is this deep.  Bigger packets get split in

     * usb_generic_handle_packet but we can also do the splitting locally

     * for performance.  It turns out we can also have a bigger FIFO and

     * ignore the limit set in ep->maxp[1].  The Linux MUSB driver deals

     * OK with single packets of even 32KB and we avoid splitting, however

     * usb_msd.c sometimes sends a packet bigger than what Linux expects

     * (e.g. 8192 bytes instead of 4096) and we get an OVERRUN.  Splitting

     * hides this overrun from Linux.  Up to 4096 everything is fine

     * though.  Currently this is disabled.

     *

     * XXX: mind ep->fifosize.  */

    total = MIN(ep->maxp[1] & 0x3ff, sizeof(s->buf));

#ifdef SETUPLEN_HACK

    /* Why should *we* do that instead of Linux?  */

    if (!epnum) {

        if (ep->packey[0].p.devaddr == 2) {

            total = MIN(s->setup_len, 8);

        } else {

            total = MIN(s->setup_len, 64);

        }

        s->setup_len -= total;

    }

#endif

    return musb_packet(s, ep, epnum, USB_TOKEN_IN,

                    total, musb_rx_packet_complete, 1);

}

static uint8_t musb_read_fifo(MUSBEndPoint *ep)

{

    uint8_t value;

    if (ep->fifolen[1] >= 64) {

        /* We have a FIFO underrun */

        TRACE("EP%d FIFO is now empty, stop reading", ep->epnum);

        return 0x00000000;

    }

    /* In DMA mode clear RXPKTRDY and set REQPKT automatically

     * (if AUTOREQ is set) */

    ep->csr[1] &= ~MGC_M_RXCSR_FIFOFULL;

    value=ep->buf[1][ep->fifostart[1] + ep->fifolen[1] ++];

    TRACE("EP%d 0x%02x, %d", ep->epnum, value, ep->fifolen[1] );

    return value;

}

static void musb_write_fifo(MUSBEndPoint *ep, uint8_t value)

{

    TRACE("EP%d = %02x", ep->epnum, value);

    if (ep->fifolen[0] >= 64) {

        /* We have a FIFO overrun */

        TRACE("EP%d FIFO exceeded 64 bytes, stop feeding data", ep->epnum);

        return;

     }

     ep->buf[0][ep->fifostart[0] + ep->fifolen[0] ++] = value;

     ep->csr[0] |= MGC_M_TXCSR_FIFONOTEMPTY;

}

static void musb_ep_frame_cancel(MUSBEndPoint *ep, int dir)

{

    if (ep->intv_timer[dir])

        qemu_del_timer(ep->intv_timer[dir]);

}

/* Bus control */

static uint8_t musb_busctl_readb(void *opaque, int ep, int addr)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    /* For USB2.0 HS hubs only */

    case MUSB_HDRC_TXHUBADDR:

        return s->ep[ep].haddr[0];

    case MUSB_HDRC_TXHUBPORT:

        return s->ep[ep].hport[0];

    case MUSB_HDRC_RXHUBADDR:

        return s->ep[ep].haddr[1];

    case MUSB_HDRC_RXHUBPORT:

        return s->ep[ep].hport[1];

    default:

        TRACE("unknown register 0x%02x", addr);

        return 0x00;

    };

}

static void musb_busctl_writeb(void *opaque, int ep, int addr, uint8_t value)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    case MUSB_HDRC_TXFUNCADDR:

        s->ep[ep].faddr[0] = value;

        break;

    case MUSB_HDRC_RXFUNCADDR:

        s->ep[ep].faddr[1] = value;

        break;

    case MUSB_HDRC_TXHUBADDR:

        s->ep[ep].haddr[0] = value;

        break;

    case MUSB_HDRC_TXHUBPORT:

        s->ep[ep].hport[0] = value;

        break;

    case MUSB_HDRC_RXHUBADDR:

        s->ep[ep].haddr[1] = value;

        break;

    case MUSB_HDRC_RXHUBPORT:

        s->ep[ep].hport[1] = value;

        break;

    default:

        TRACE("unknown register 0x%02x", addr);

        break;

    };

}

static uint16_t musb_busctl_readh(void *opaque, int ep, int addr)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    case MUSB_HDRC_TXFUNCADDR:

        return s->ep[ep].faddr[0];

    case MUSB_HDRC_RXFUNCADDR:

        return s->ep[ep].faddr[1];

    default:

        return musb_busctl_readb(s, ep, addr) |

                (musb_busctl_readb(s, ep, addr | 1) << 8);

    };

}

static void musb_busctl_writeh(void *opaque, int ep, int addr, uint16_t value)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    case MUSB_HDRC_TXFUNCADDR:

        s->ep[ep].faddr[0] = value;

        break;

    case MUSB_HDRC_RXFUNCADDR:

        s->ep[ep].faddr[1] = value;

        break;

    default:

        musb_busctl_writeb(s, ep, addr, value & 0xff);

        musb_busctl_writeb(s, ep, addr | 1, value >> 8);

    };

}

/* Endpoint control */

static uint8_t musb_ep_readb(void *opaque, int ep, int addr)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    case MUSB_HDRC_TXTYPE:

        return s->ep[ep].type[0];

    case MUSB_HDRC_TXINTERVAL:

        return s->ep[ep].interval[0];

    case MUSB_HDRC_RXTYPE:

        return s->ep[ep].type[1];

    case MUSB_HDRC_RXINTERVAL:

        return s->ep[ep].interval[1];

    case (MUSB_HDRC_FIFOSIZE & ~1):

        return 0x00;

    case MUSB_HDRC_FIFOSIZE:

        return ep ? s->ep[ep].fifosize : s->ep[ep].config;

    case MUSB_HDRC_RXCOUNT:

        return s->ep[ep].rxcount;

    default:

        TRACE("unknown register 0x%02x", addr);

        return 0x00;

    };

}

static void musb_ep_writeb(void *opaque, int ep, int addr, uint8_t value)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    case MUSB_HDRC_TXTYPE:

        s->ep[ep].type[0] = value;

        break;

    case MUSB_HDRC_TXINTERVAL:

        s->ep[ep].interval[0] = value;

        musb_ep_frame_cancel(&s->ep[ep], 0);

        break;

    case MUSB_HDRC_RXTYPE:

        s->ep[ep].type[1] = value;

        break;

    case MUSB_HDRC_RXINTERVAL:

        s->ep[ep].interval[1] = value;

        musb_ep_frame_cancel(&s->ep[ep], 1);

        break;

    case (MUSB_HDRC_FIFOSIZE & ~1):

        break;

    case MUSB_HDRC_FIFOSIZE:

        TRACE("somebody messes with fifosize (now %i bytes)", value);

        s->ep[ep].fifosize = value;

        break;

    default:

        TRACE("unknown register 0x%02x", addr);

        break;

    };

}

static uint16_t musb_ep_readh(void *opaque, int ep, int addr)

{

    MUSBState *s = (MUSBState *) opaque;

    uint16_t ret;

    switch (addr) {

    case MUSB_HDRC_TXMAXP:

        return s->ep[ep].maxp[0];

    case MUSB_HDRC_TXCSR:

        return s->ep[ep].csr[0];

    case MUSB_HDRC_RXMAXP:

        return s->ep[ep].maxp[1];

    case MUSB_HDRC_RXCSR:

        ret = s->ep[ep].csr[1];

        /* TODO: This and other bits probably depend on

         * ep->csr[1] & MGC_M_RXCSR_AUTOCLEAR.  */

        if (s->ep[ep].csr[1] & MGC_M_RXCSR_AUTOCLEAR)

            s->ep[ep].csr[1] &= ~MGC_M_RXCSR_RXPKTRDY;

        return ret;

    case MUSB_HDRC_RXCOUNT:

        return s->ep[ep].rxcount;

    default:

        return musb_ep_readb(s, ep, addr) |

                (musb_ep_readb(s, ep, addr | 1) << 8);

    };

}

static void musb_ep_writeh(void *opaque, int ep, int addr, uint16_t value)

{

    MUSBState *s = (MUSBState *) opaque;

    switch (addr) {

    case MUSB_HDRC_TXMAXP:

        s->ep[ep].maxp[0] = value;

        break;

    case MUSB_HDRC_TXCSR:

        if (ep) {

            s->ep[ep].csr[0] &= value & 0xa6;

            s->ep[ep].csr[0] |= value & 0xff59;

        } else {

            s->ep[ep].csr[0] &= value & 0x85;

            s->ep[ep].csr[0] |= value & 0xf7a;

        }

        musb_ep_frame_cancel(&s->ep[ep], 0);

        if ((ep && (value & MGC_M_TXCSR_FLUSHFIFO)) ||

                        (!ep && (value & MGC_M_CSR0_FLUSHFIFO))) {

            s->ep[ep].fifolen[0] = 0;

            s->ep[ep].fifostart[0] = 0;

            if (ep)

                s->ep[ep].csr[0] &=

                        ~(MGC_M_TXCSR_FIFONOTEMPTY | MGC_M_TXCSR_TXPKTRDY);

            else

                s->ep[ep].csr[0] &=

                        ~(MGC_M_CSR0_TXPKTRDY | MGC_M_CSR0_RXPKTRDY);

        }

        if (

                        (ep &&

#ifdef CLEAR_NAK

                         (value & MGC_M_TXCSR_TXPKTRDY) &&

                         !(value & MGC_M_TXCSR_H_NAKTIMEOUT)) ||

#else

                         (value & MGC_M_TXCSR_TXPKTRDY)) ||

#endif

                        (!ep &&

#ifdef CLEAR_NAK

                         (value & MGC_M_CSR0_TXPKTRDY) &&

                         !(value & MGC_M_CSR0_H_NAKTIMEOUT)))

#else

                         (value & MGC_M_CSR0_TXPKTRDY)))

#endif

            musb_tx_rdy(s, ep);

        if (!ep &&

                        (value & MGC_M_CSR0_H_REQPKT) &&

#ifdef CLEAR_NAK

                        !(value & (MGC_M_CSR0_H_NAKTIMEOUT |

                                        MGC_M_CSR0_RXPKTRDY)))

#else

                        !(value & MGC_M_CSR0_RXPKTRDY))

#endif

            musb_rx_req(s, ep);

        break;

    case MUSB_HDRC_RXMAXP:

        s->ep[ep].maxp[1] = value;

        break;

    case MUSB_HDRC_RXCSR:

        /* (DMA mode only) */

        if (

                (value & MGC_M_RXCSR_H_AUTOREQ) &&

                !(value & MGC_M_RXCSR_RXPKTRDY) &&

                (s->ep[ep].csr[1] & MGC_M_RXCSR_RXPKTRDY))

            value |= MGC_M_RXCSR_H_REQPKT;

        s->ep[ep].csr[1] &= 0x102 | (value & 0x4d);

        s->ep[ep].csr[1] |= value & 0xfeb0;

        musb_ep_frame_cancel(&s->ep[ep], 1);

        if (value & MGC_M_RXCSR_FLUSHFIFO) {

            s->ep[ep].fifolen[1] = 0;

            s->ep[ep].fifostart[1] = 0;

            s->ep[ep].csr[1] &= ~(MGC_M_RXCSR_FIFOFULL | MGC_M_RXCSR_RXPKTRDY);

            /* If double buffering and we have two packets ready, flush

             * only the first one and set up the fifo at the second packet.  */

        }

#ifdef CLEAR_NAK

        if ((value & MGC_M_RXCSR_H_REQPKT) && !(value & MGC_M_RXCSR_DATAERROR))

#else

        if (value & MGC_M_RXCSR_H_REQPKT)

#endif

            musb_rx_req(s, ep);

        break;

    case MUSB_HDRC_RXCOUNT:

        s->ep[ep].rxcount = value;

        break;

    default:

        musb_ep_writeb(s, ep, addr, value & 0xff);

        musb_ep_writeb(s, ep, addr | 1, value >> 8);

    };

}

/* Generic control */

static uint32_t musb_readb(void *opaque, target_phys_addr_t addr)

{

    MUSBState *s = (MUSBState *) opaque;

    int ep, i;

    uint8_t ret;

    switch (addr) {

    case MUSB_HDRC_FADDR:

        return s->faddr;

    case MUSB_HDRC_POWER:

        return s->power;

    case MUSB_HDRC_INTRUSB:

        ret = s->intr;

        for (i = 0; i < sizeof(ret) * 8; i ++)

            if (ret & (1 << i))

                musb_intr_set(s, i, 0);

        return ret;

    case MUSB_HDRC_INTRUSBE:

        return s->mask;

    case MUSB_HDRC_INDEX:

        return s->idx;

    case MUSB_HDRC_TESTMODE:

        return 0x00;

    case MUSB_HDRC_EP_IDX ... (MUSB_HDRC_EP_IDX + 0xf):

        return musb_ep_readb(s, s->idx, addr & 0xf);

    case MUSB_HDRC_DEVCTL:

        return s->devctl;

    case MUSB_HDRC_TXFIFOSZ:

    case MUSB_HDRC_RXFIFOSZ:

    case MUSB_HDRC_VCTRL:

        /* TODO */

        return 0x00;

    case MUSB_HDRC_HWVERS:

        return (1 << 10) | 400;

    case (MUSB_HDRC_VCTRL | 1):

    case (MUSB_HDRC_HWVERS | 1):

    case (MUSB_HDRC_DEVCTL | 1):

        return 0x00;

    case MUSB_HDRC_BUSCTL ... (MUSB_HDRC_BUSCTL + 0x7f):

        ep = (addr >> 3) & 0xf;

        return musb_busctl_readb(s, ep, addr & 0x7);

    case MUSB_HDRC_EP ... (MUSB_HDRC_EP + 0xff):

        ep = (addr >> 4) & 0xf;

        return musb_ep_readb(s, ep, addr & 0xf);

    case MUSB_HDRC_FIFO ... (MUSB_HDRC_FIFO + 0x3f):

        ep = ((addr - MUSB_HDRC_FIFO) >> 2) & 0xf;

        return musb_read_fifo(s->ep + ep);

    default:

        TRACE("unknown register 0x%02x", (int) addr);

        return 0x00;

    };

}

static void musb_writeb(void *opaque, target_phys_addr_t addr, uint32_t value)

{

    MUSBState *s = (MUSBState *) opaque;

    int ep;

    switch (addr) {

    case MUSB_HDRC_FADDR:

        s->faddr = value & 0x7f;

        break;

    case MUSB_HDRC_POWER:

        s->power = (value & 0xef) | (s->power & 0x10);

        /* MGC_M_POWER_RESET is also read-only in Peripheral Mode */

        if ((value & MGC_M_POWER_RESET) && s->port.dev) {

            usb_send_msg(s->port.dev, USB_MSG_RESET);

            /* Negotiate high-speed operation if MGC_M_POWER_HSENAB is set.  */

            if ((value & MGC_M_POWER_HSENAB) &&

                            s->port.dev->speed == USB_SPEED_HIGH)

                s->power |= MGC_M_POWER_HSMODE;        /* Success */

            /* Restart frame counting.  */

        }

        if (value & MGC_M_POWER_SUSPENDM) {

            /* When all transfers finish, suspend and if MGC_M_POWER_ENSUSPEND

             * is set, also go into low power mode.  Frame counting stops.  */

            /* XXX: Cleared when the interrupt register is read */