Archipelago » qemu

/*

 * QEMU USB OHCI Emulation

 * Copyright (c) 2004 Gianni Tedesco

 * Copyright (c) 2006 CodeSourcery

 * Copyright (c) 2006 Openedhand Ltd.

 *

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

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

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

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * TODO:

 *  o Isochronous transfers

 *  o Allocate bandwidth in frames properly

 *  o Disable timers when nothing needs to be done, or remove timer usage

 *    all together.

 *  o Handle unrecoverable errors properly

 *  o BIOS work to boot from USB storage

*/

#include "vl.h"

//#define DEBUG_OHCI

/* Dump packet contents.  */

//#define DEBUG_PACKET

/* This causes frames to occur 1000x slower */

//#define OHCI_TIME_WARP 1

#ifdef DEBUG_OHCI

#define dprintf printf

#else

#define dprintf(...)

#endif

/* Number of Downstream Ports on the root hub.  */

#define OHCI_MAX_PORTS 15

static int64_t usb_frame_time;

static int64_t usb_bit_time;

typedef struct OHCIPort {

    USBPort port;

    uint32_t ctrl;

} OHCIPort;

enum ohci_type {

    OHCI_TYPE_PCI,

    OHCI_TYPE_PXA

};

typedef struct {

    qemu_irq irq;

    enum ohci_type type;

    target_phys_addr_t mem_base;

    int mem;

    int num_ports;

    const char *name;

    QEMUTimer *eof_timer;

    int64_t sof_time;

    /* OHCI state */

    /* Control partition */

    uint32_t ctl, status;

    uint32_t intr_status;

    uint32_t intr;

    /* memory pointer partition */

    uint32_t hcca;

    uint32_t ctrl_head, ctrl_cur;

    uint32_t bulk_head, bulk_cur;

    uint32_t per_cur;

    uint32_t done;

    int done_count;

    /* Frame counter partition */

    uint32_t fsmps:15;

    uint32_t fit:1;

    uint32_t fi:14;

    uint32_t frt:1;

    uint16_t frame_number;

    uint16_t padding;

    uint32_t pstart;

    uint32_t lst;

    /* Root Hub partition */

    uint32_t rhdesc_a, rhdesc_b;

    uint32_t rhstatus;

    OHCIPort rhport[OHCI_MAX_PORTS];

    /* PXA27x Non-OHCI events */

    uint32_t hstatus;

    uint32_t hmask;

    uint32_t hreset;

    uint32_t htest;

    /* Active packets.  */

    uint32_t old_ctl;

    USBPacket usb_packet;

    uint8_t usb_buf[8192];

    uint32_t async_td;

    int async_complete;

} OHCIState;

/* Host Controller Communications Area */

struct ohci_hcca {

    uint32_t intr[32];

    uint16_t frame, pad;

    uint32_t done;

};

/* Bitfields for the first word of an Endpoint Desciptor.  */

#define OHCI_ED_FA_SHIFT  0

#define OHCI_ED_FA_MASK   (0x7f<<OHCI_ED_FA_SHIFT)

#define OHCI_ED_EN_SHIFT  7

#define OHCI_ED_EN_MASK   (0xf<<OHCI_ED_EN_SHIFT)

#define OHCI_ED_D_SHIFT   11

#define OHCI_ED_D_MASK    (3<<OHCI_ED_D_SHIFT)

#define OHCI_ED_S         (1<<13)

#define OHCI_ED_K         (1<<14)

#define OHCI_ED_F         (1<<15)

#define OHCI_ED_MPS_SHIFT 7

#define OHCI_ED_MPS_MASK  (0xf<<OHCI_ED_FA_SHIFT)

/* Flags in the head field of an Endpoint Desciptor.  */

#define OHCI_ED_H         1

#define OHCI_ED_C         2

/* Bitfields for the first word of a Transfer Desciptor.  */

#define OHCI_TD_R         (1<<18)

#define OHCI_TD_DP_SHIFT  19

#define OHCI_TD_DP_MASK   (3<<OHCI_TD_DP_SHIFT)

#define OHCI_TD_DI_SHIFT  21

#define OHCI_TD_DI_MASK   (7<<OHCI_TD_DI_SHIFT)

#define OHCI_TD_T0        (1<<24)

#define OHCI_TD_T1        (1<<24)

#define OHCI_TD_EC_SHIFT  26

#define OHCI_TD_EC_MASK   (3<<OHCI_TD_EC_SHIFT)

#define OHCI_TD_CC_SHIFT  28

#define OHCI_TD_CC_MASK   (0xf<<OHCI_TD_CC_SHIFT)

#define OHCI_DPTR_MASK    0xfffffff0

#define OHCI_BM(val, field) \

  (((val) & OHCI_##field##_MASK) >> OHCI_##field##_SHIFT)

#define OHCI_SET_BM(val, field, newval) do { \

    val &= ~OHCI_##field##_MASK; \

    val |= ((newval) << OHCI_##field##_SHIFT) & OHCI_##field##_MASK; \

    } while(0)

/* endpoint descriptor */

struct ohci_ed {

    uint32_t flags;

    uint32_t tail;

    uint32_t head;

    uint32_t next;

};

/* General transfer descriptor */

struct ohci_td {

    uint32_t flags;

    uint32_t cbp;

    uint32_t next;

    uint32_t be;

};

#define USB_HZ                      12000000

/* OHCI Local stuff */

#define OHCI_CTL_CBSR         ((1<<0)|(1<<1))

#define OHCI_CTL_PLE          (1<<2)

#define OHCI_CTL_IE           (1<<3)

#define OHCI_CTL_CLE          (1<<4)

#define OHCI_CTL_BLE          (1<<5)

#define OHCI_CTL_HCFS         ((1<<6)|(1<<7))

#define  OHCI_USB_RESET       0x00

#define  OHCI_USB_RESUME      0x40

#define  OHCI_USB_OPERATIONAL 0x80

#define  OHCI_USB_SUSPEND     0xc0

#define OHCI_CTL_IR           (1<<8)

#define OHCI_CTL_RWC          (1<<9)

#define OHCI_CTL_RWE          (1<<10)

#define OHCI_STATUS_HCR       (1<<0)

#define OHCI_STATUS_CLF       (1<<1)

#define OHCI_STATUS_BLF       (1<<2)

#define OHCI_STATUS_OCR       (1<<3)

#define OHCI_STATUS_SOC       ((1<<6)|(1<<7))

#define OHCI_INTR_SO          (1<<0) /* Scheduling overrun */

#define OHCI_INTR_WD          (1<<1) /* HcDoneHead writeback */

#define OHCI_INTR_SF          (1<<2) /* Start of frame */

#define OHCI_INTR_RD          (1<<3) /* Resume detect */

#define OHCI_INTR_UE          (1<<4) /* Unrecoverable error */

#define OHCI_INTR_FNO         (1<<5) /* Frame number overflow */

#define OHCI_INTR_RHSC        (1<<6) /* Root hub status change */

#define OHCI_INTR_OC          (1<<30) /* Ownership change */

#define OHCI_INTR_MIE         (1<<31) /* Master Interrupt Enable */

#define OHCI_HCCA_SIZE        0x100

#define OHCI_HCCA_MASK        0xffffff00

#define OHCI_EDPTR_MASK       0xfffffff0

#define OHCI_FMI_FI           0x00003fff

#define OHCI_FMI_FSMPS        0xffff0000

#define OHCI_FMI_FIT          0x80000000

#define OHCI_FR_RT            (1<<31)

#define OHCI_LS_THRESH        0x628

#define OHCI_RHA_RW_MASK      0x00000000 /* Mask of supported features.  */

#define OHCI_RHA_PSM          (1<<8)

#define OHCI_RHA_NPS          (1<<9)

#define OHCI_RHA_DT           (1<<10)

#define OHCI_RHA_OCPM         (1<<11)

#define OHCI_RHA_NOCP         (1<<12)

#define OHCI_RHA_POTPGT_MASK  0xff000000

#define OHCI_RHS_LPS          (1<<0)

#define OHCI_RHS_OCI          (1<<1)

#define OHCI_RHS_DRWE         (1<<15)

#define OHCI_RHS_LPSC         (1<<16)

#define OHCI_RHS_OCIC         (1<<17)

#define OHCI_RHS_CRWE         (1<<31)

#define OHCI_PORT_CCS         (1<<0)

#define OHCI_PORT_PES         (1<<1)

#define OHCI_PORT_PSS         (1<<2)

#define OHCI_PORT_POCI        (1<<3)

#define OHCI_PORT_PRS         (1<<4)

#define OHCI_PORT_PPS         (1<<8)

#define OHCI_PORT_LSDA        (1<<9)

#define OHCI_PORT_CSC         (1<<16)

#define OHCI_PORT_PESC        (1<<17)

#define OHCI_PORT_PSSC        (1<<18)

#define OHCI_PORT_OCIC        (1<<19)

#define OHCI_PORT_PRSC        (1<<20)

#define OHCI_PORT_WTC         (OHCI_PORT_CSC|OHCI_PORT_PESC|OHCI_PORT_PSSC \

                               |OHCI_PORT_OCIC|OHCI_PORT_PRSC)

#define OHCI_TD_DIR_SETUP     0x0

#define OHCI_TD_DIR_OUT       0x1

#define OHCI_TD_DIR_IN        0x2

#define OHCI_TD_DIR_RESERVED  0x3

#define OHCI_CC_NOERROR             0x0

#define OHCI_CC_CRC                 0x1

#define OHCI_CC_BITSTUFFING         0x2

#define OHCI_CC_DATATOGGLEMISMATCH  0x3

#define OHCI_CC_STALL               0x4

#define OHCI_CC_DEVICENOTRESPONDING 0x5

#define OHCI_CC_PIDCHECKFAILURE     0x6

#define OHCI_CC_UNDEXPETEDPID       0x7

#define OHCI_CC_DATAOVERRUN         0x8

#define OHCI_CC_DATAUNDERRUN        0x9

#define OHCI_CC_BUFFEROVERRUN       0xc

#define OHCI_CC_BUFFERUNDERRUN      0xd

#define OHCI_HRESET_FSBIR       (1 << 0)

/* Update IRQ levels */

static inline void ohci_intr_update(OHCIState *ohci)

{

    int level = 0;

    if ((ohci->intr & OHCI_INTR_MIE) &&

        (ohci->intr_status & ohci->intr))

        level = 1;

    qemu_set_irq(ohci->irq, level);

}

/* Set an interrupt */

static inline void ohci_set_interrupt(OHCIState *ohci, uint32_t intr)

{

    ohci->intr_status |= intr;

    ohci_intr_update(ohci);

}

/* Attach or detach a device on a root hub port.  */

static void ohci_attach(USBPort *port1, USBDevice *dev)

{

    OHCIState *s = port1->opaque;

    OHCIPort *port = &s->rhport[port1->index];

    uint32_t old_state = port->ctrl;

    if (dev) {

        if (port->port.dev) {

            usb_attach(port1, NULL);

        }

        /* set connect status */

        port->ctrl |= OHCI_PORT_CCS | OHCI_PORT_CSC;

        /* update speed */

        if (dev->speed == USB_SPEED_LOW)

            port->ctrl |= OHCI_PORT_LSDA;

        else

            port->ctrl &= ~OHCI_PORT_LSDA;

        port->port.dev = dev;

        /* notify of remote-wakeup */

        if ((s->ctl & OHCI_CTL_HCFS) == OHCI_USB_SUSPEND)

            ohci_set_interrupt(s, OHCI_INTR_RD);

        /* send the attach message */

        usb_send_msg(dev, USB_MSG_ATTACH);

        dprintf("usb-ohci: Attached port %d\n", port1->index);

    } else {

        /* set connect status */

        if (port->ctrl & OHCI_PORT_CCS) {

            port->ctrl &= ~OHCI_PORT_CCS;

            port->ctrl |= OHCI_PORT_CSC;

        }

        /* disable port */

        if (port->ctrl & OHCI_PORT_PES) {

            port->ctrl &= ~OHCI_PORT_PES;

            port->ctrl |= OHCI_PORT_PESC;

        }

        dev = port->port.dev;

        if (dev) {

            /* send the detach message */

            usb_send_msg(dev, USB_MSG_DETACH);

        }

        port->port.dev = NULL;

        dprintf("usb-ohci: Detached port %d\n", port1->index);

    }

    if (old_state != port->ctrl)

        ohci_set_interrupt(s, OHCI_INTR_RHSC);

}

/* Reset the controller */

static void ohci_reset(OHCIState *ohci)

{

    OHCIPort *port;

    int i;

    ohci->ctl = 0;

    ohci->old_ctl = 0;

    ohci->status = 0;

    ohci->intr_status = 0;

    ohci->intr = OHCI_INTR_MIE;

    ohci->hcca = 0;

    ohci->ctrl_head = ohci->ctrl_cur = 0;

    ohci->bulk_head = ohci->bulk_cur = 0;

    ohci->per_cur = 0;

    ohci->done = 0;

    ohci->done_count = 7;

    /* FSMPS is marked TBD in OCHI 1.0, what gives ffs?

     * I took the value linux sets ...

     */

    ohci->fsmps = 0x2778;

    ohci->fi = 0x2edf;

    ohci->fit = 0;

    ohci->frt = 0;

    ohci->frame_number = 0;

    ohci->pstart = 0;

    ohci->lst = OHCI_LS_THRESH;

    ohci->rhdesc_a = OHCI_RHA_NPS | ohci->num_ports;

    ohci->rhdesc_b = 0x0; /* Impl. specific */

    ohci->rhstatus = 0;

    for (i = 0; i < ohci->num_ports; i++)

      {

        port = &ohci->rhport[i];

        port->ctrl = 0;

        if (port->port.dev)

            ohci_attach(&port->port, port->port.dev);

      }

    if (ohci->async_td) {

        usb_cancel_packet(&ohci->usb_packet);

        ohci->async_td = 0;

    }

    dprintf("usb-ohci: Reset %s\n", ohci->name);

}

/* Get an array of dwords from main memory */

static inline int get_dwords(uint32_t addr, uint32_t *buf, int num)

{

    int i;

    for (i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {

        cpu_physical_memory_rw(addr, (uint8_t *)buf, sizeof(*buf), 0);

        *buf = le32_to_cpu(*buf);

    }

    return 1;

}

/* Put an array of dwords in to main memory */

static inline int put_dwords(uint32_t addr, uint32_t *buf, int num)

{

    int i;

    for (i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {

        uint32_t tmp = cpu_to_le32(*buf);

        cpu_physical_memory_rw(addr, (uint8_t *)&tmp, sizeof(tmp), 1);

    }

    return 1;

}

static inline int ohci_read_ed(uint32_t addr, struct ohci_ed *ed)

{

    return get_dwords(addr, (uint32_t *)ed, sizeof(*ed) >> 2);

}

static inline int ohci_read_td(uint32_t addr, struct ohci_td *td)

{

    return get_dwords(addr, (uint32_t *)td, sizeof(*td) >> 2);

}

static inline int ohci_put_ed(uint32_t addr, struct ohci_ed *ed)

{

    return put_dwords(addr, (uint32_t *)ed, sizeof(*ed) >> 2);

}

static inline int ohci_put_td(uint32_t addr, struct ohci_td *td)

{

    return put_dwords(addr, (uint32_t *)td, sizeof(*td) >> 2);

}

/* Read/Write the contents of a TD from/to main memory.  */

static void ohci_copy_td(struct ohci_td *td, uint8_t *buf, int len, int write)

{

    uint32_t ptr;

    uint32_t n;

    ptr = td->cbp;

    n = 0x1000 - (ptr & 0xfff);

    if (n > len)

        n = len;

    cpu_physical_memory_rw(ptr, buf, n, write);

    if (n == len)

        return;

    ptr = td->be & ~0xfffu;

    buf += n;

    cpu_physical_memory_rw(ptr, buf, len - n, write);

}

static void ohci_process_lists(OHCIState *ohci);

static void ohci_async_complete_packet(USBPacket * packet, void *opaque)

{

    OHCIState *ohci = opaque;

#ifdef DEBUG_PACKET

    dprintf("Async packet complete\n");

#endif

    ohci->async_complete = 1;

    ohci_process_lists(ohci);

}

/* Service a transport descriptor.

   Returns nonzero to terminate processing of this endpoint.  */

static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)

{

    int dir;

    size_t len = 0;

    char *str = NULL;

    int pid;

    int ret;

    int i;

    USBDevice *dev;

    struct ohci_td td;

    uint32_t addr;

    int flag_r;

    int completion;

    addr = ed->head & OHCI_DPTR_MASK;

    /* See if this TD has already been submitted to the device.  */

    completion = (addr == ohci->async_td);

    if (completion && !ohci->async_complete) {

#ifdef DEBUG_PACKET

        dprintf("Skipping async TD\n");

#endif

        return 1;

    }

    if (!ohci_read_td(addr, &td)) {

        fprintf(stderr, "usb-ohci: TD read error at %x\n", addr);

        return 0;

    }

    dir = OHCI_BM(ed->flags, ED_D);

    switch (dir) {

    case OHCI_TD_DIR_OUT:

    case OHCI_TD_DIR_IN:

        /* Same value.  */

        break;

    default:

        dir = OHCI_BM(td.flags, TD_DP);

        break;

    }

    switch (dir) {

    case OHCI_TD_DIR_IN:

        str = "in";

        pid = USB_TOKEN_IN;

        break;

    case OHCI_TD_DIR_OUT:

        str = "out";

        pid = USB_TOKEN_OUT;

        break;

    case OHCI_TD_DIR_SETUP:

        str = "setup";

        pid = USB_TOKEN_SETUP;

        break;

    default:

        fprintf(stderr, "usb-ohci: Bad direction\n");

        return 1;

    }

    if (td.cbp && td.be) {

        if ((td.cbp & 0xfffff000) != (td.be & 0xfffff000)) {

            len = (td.be & 0xfff) + 0x1001 - (td.cbp & 0xfff);

        } else {

            len = (td.be - td.cbp) + 1;

        }

        if (len && dir != OHCI_TD_DIR_IN && !completion) {

            ohci_copy_td(&td, ohci->usb_buf, len, 0);

        }

    }

    flag_r = (td.flags & OHCI_TD_R) != 0;

#ifdef DEBUG_PACKET

    dprintf(" TD @ 0x%.8x %u bytes %s r=%d cbp=0x%.8x be=0x%.8x\n",

            addr, len, str, flag_r, td.cbp, td.be);

    if (len >= 0 && dir != OHCI_TD_DIR_IN) {

        dprintf("  data:");

        for (i = 0; i < len; i++)

            printf(" %.2x", ohci->usb_buf[i]);

        dprintf("\n");

    }

#endif

    if (completion) {

        ret = ohci->usb_packet.len;

        ohci->async_td = 0;

        ohci->async_complete = 0;

    } else {

        ret = USB_RET_NODEV;

        for (i = 0; i < ohci->num_ports; i++) {

            dev = ohci->rhport[i].port.dev;

            if ((ohci->rhport[i].ctrl & OHCI_PORT_PES) == 0)

                continue;

            if (ohci->async_td) {

                /* ??? The hardware should allow one active packet per

                   endpoint.  We only allow one active packet per controller.

                   This should be sufficient as long as devices respond in a

                   timely manner.

                 */

#ifdef DEBUG_PACKET

                dprintf("Too many pending packets\n");

#endif

                return 1;

            }

            ohci->usb_packet.pid = pid;

            ohci->usb_packet.devaddr = OHCI_BM(ed->flags, ED_FA);

            ohci->usb_packet.devep = OHCI_BM(ed->flags, ED_EN);

            ohci->usb_packet.data = ohci->usb_buf;

            ohci->usb_packet.len = len;

            ohci->usb_packet.complete_cb = ohci_async_complete_packet;

            ohci->usb_packet.complete_opaque = ohci;

            ret = dev->handle_packet(dev, &ohci->usb_packet);

            if (ret != USB_RET_NODEV)

                break;

        }

#ifdef DEBUG_PACKET

        dprintf("ret=%d\n", ret);

#endif

        if (ret == USB_RET_ASYNC) {

            ohci->async_td = addr;

            return 1;

        }

    }

    if (ret >= 0) {

        if (dir == OHCI_TD_DIR_IN) {

            ohci_copy_td(&td, ohci->usb_buf, ret, 1);

#ifdef DEBUG_PACKET

            dprintf("  data:");

            for (i = 0; i < ret; i++)

                printf(" %.2x", ohci->usb_buf[i]);

            dprintf("\n");

#endif

        } else {

            ret = len;

        }

    }

    /* Writeback */

    if (ret == len || (dir == OHCI_TD_DIR_IN && ret >= 0 && flag_r)) {

        /* Transmission succeeded.  */

        if (ret == len) {

            td.cbp = 0;

        } else {

            td.cbp += ret;

            if ((td.cbp & 0xfff) + ret > 0xfff) {

                td.cbp &= 0xfff;

                td.cbp |= td.be & ~0xfff;

            }

        }

        td.flags |= OHCI_TD_T1;

        td.flags ^= OHCI_TD_T0;

        OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_NOERROR);

        OHCI_SET_BM(td.flags, TD_EC, 0);

        ed->head &= ~OHCI_ED_C;

        if (td.flags & OHCI_TD_T0)

            ed->head |= OHCI_ED_C;

    } else {

        if (ret >= 0) {

            dprintf("usb-ohci: Underrun\n");

            OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_DATAUNDERRUN);

        } else {

            switch (ret) {

            case USB_RET_NODEV:

                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_DEVICENOTRESPONDING);

            case USB_RET_NAK:

                dprintf("usb-ohci: got NAK\n");

                return 1;

            case USB_RET_STALL:

                dprintf("usb-ohci: got STALL\n");

                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_STALL);

                break;

            case USB_RET_BABBLE:

                dprintf("usb-ohci: got BABBLE\n");

                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_DATAOVERRUN);

                break;

            default:

                fprintf(stderr, "usb-ohci: Bad device response %d\n", ret);

                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_UNDEXPETEDPID);

                OHCI_SET_BM(td.flags, TD_EC, 3);

                break;

            }

        }

        ed->head |= OHCI_ED_H;

    }

    /* Retire this TD */

    ed->head &= ~OHCI_DPTR_MASK;

    ed->head |= td.next & OHCI_DPTR_MASK;

    td.next = ohci->done;

    ohci->done = addr;

    i = OHCI_BM(td.flags, TD_DI);

    if (i < ohci->done_count)

        ohci->done_count = i;

    ohci_put_td(addr, &td);

    return OHCI_BM(td.flags, TD_CC) != OHCI_CC_NOERROR;

}

/* Service an endpoint list.  Returns nonzero if active TD were found.  */

static int ohci_service_ed_list(OHCIState *ohci, uint32_t head)

{

    struct ohci_ed ed;

    uint32_t next_ed;

    uint32_t cur;

    int active;

    active = 0;

    if (head == 0)

        return 0;

    for (cur = head; cur; cur = next_ed) {

        if (!ohci_read_ed(cur, &ed)) {

            fprintf(stderr, "usb-ohci: ED read error at %x\n", cur);

            return 0;

        }

        next_ed = ed.next & OHCI_DPTR_MASK;

        if ((ed.head & OHCI_ED_H) || (ed.flags & OHCI_ED_K)) {

            uint32_t addr;

            /* Cancel pending packets for ED that have been paused.  */

            addr = ed.head & OHCI_DPTR_MASK;

            if (ohci->async_td && addr == ohci->async_td) {

                usb_cancel_packet(&ohci->usb_packet);

                ohci->async_td = 0;

            }

            continue;

        }

        /* Skip isochronous endpoints.  */

        if (ed.flags & OHCI_ED_F)

          continue;

        while ((ed.head & OHCI_DPTR_MASK) != ed.tail) {

#ifdef DEBUG_PACKET

            dprintf("ED @ 0x%.8x fa=%u en=%u d=%u s=%u k=%u f=%u mps=%u "

                    "h=%u c=%u\n  head=0x%.8x tailp=0x%.8x next=0x%.8x\n", cur,

                    OHCI_BM(ed.flags, ED_FA), OHCI_BM(ed.flags, ED_EN),

                    OHCI_BM(ed.flags, ED_D), (ed.flags & OHCI_ED_S)!= 0,

                    (ed.flags & OHCI_ED_K) != 0, (ed.flags & OHCI_ED_F) != 0,

                    OHCI_BM(ed.flags, ED_MPS), (ed.head & OHCI_ED_H) != 0,

                    (ed.head & OHCI_ED_C) != 0, ed.head & OHCI_DPTR_MASK,

                    ed.tail & OHCI_DPTR_MASK, ed.next & OHCI_DPTR_MASK);

#endif

            active = 1;

            if (ohci_service_td(ohci, &ed))

                break;

        }

        ohci_put_ed(cur, &ed);

    }

    return active;

}

/* Generate a SOF event, and set a timer for EOF */

static void ohci_sof(OHCIState *ohci)

{

    ohci->sof_time = qemu_get_clock(vm_clock);

    qemu_mod_timer(ohci->eof_timer, ohci->sof_time + usb_frame_time);

    ohci_set_interrupt(ohci, OHCI_INTR_SF);

}

/* Process Control and Bulk lists.  */

static void ohci_process_lists(OHCIState *ohci)

{

    if ((ohci->ctl & OHCI_CTL_CLE) && (ohci->status & OHCI_STATUS_CLF)) {

        if (ohci->ctrl_cur && ohci->ctrl_cur != ohci->ctrl_head)

          dprintf("usb-ohci: head %x, cur %x\n", ohci->ctrl_head, ohci->ctrl_cur);

        if (!ohci_service_ed_list(ohci, ohci->ctrl_head)) {

            ohci->ctrl_cur = 0;

            ohci->status &= ~OHCI_STATUS_CLF;

        }

    }

    if ((ohci->ctl & OHCI_CTL_BLE) && (ohci->status & OHCI_STATUS_BLF)) {

        if (!ohci_service_ed_list(ohci, ohci->bulk_head)) {

            ohci->bulk_cur = 0;

            ohci->status &= ~OHCI_STATUS_BLF;

        }

    }

}

/* Do frame processing on frame boundary */

static void ohci_frame_boundary(void *opaque)

{

    OHCIState *ohci = opaque;

    struct ohci_hcca hcca;

    cpu_physical_memory_rw(ohci->hcca, (uint8_t *)&hcca, sizeof(hcca), 0);

    /* Process all the lists at the end of the frame */

    if (ohci->ctl & OHCI_CTL_PLE) {

        int n;

        n = ohci->frame_number & 0x1f;

        ohci_service_ed_list(ohci, le32_to_cpu(hcca.intr[n]));

    }

    /* Cancel all pending packets if either of the lists has been disabled.  */

    if (ohci->async_td &&

        ohci->old_ctl & (~ohci->ctl) & (OHCI_CTL_BLE | OHCI_CTL_CLE)) {

        usb_cancel_packet(&ohci->usb_packet);

        ohci->async_td = 0;

    }

    ohci->old_ctl = ohci->ctl;

    ohci_process_lists(ohci);

    /* Frame boundary, so do EOF stuf here */

    ohci->frt = ohci->fit;

    /* XXX: endianness */

    ohci->frame_number = (ohci->frame_number + 1) & 0xffff;

    hcca.frame = cpu_to_le32(ohci->frame_number);

    if (ohci->done_count == 0 && !(ohci->intr_status & OHCI_INTR_WD)) {

        if (!ohci->done)

            abort();

        if (ohci->intr & ohci->intr_status)

            ohci->done |= 1;

        hcca.done = cpu_to_le32(ohci->done);

        ohci->done = 0;

        ohci->done_count = 7;

        ohci_set_interrupt(ohci, OHCI_INTR_WD);

    }

    if (ohci->done_count != 7 && ohci->done_count != 0)

        ohci->done_count--;

    /* Do SOF stuff here */

    ohci_sof(ohci);

    /* Writeback HCCA */

    cpu_physical_memory_rw(ohci->hcca, (uint8_t *)&hcca, sizeof(hcca), 1);

}

/* Start sending SOF tokens across the USB bus, lists are processed in

 * next frame

 */

static int ohci_bus_start(OHCIState *ohci)

{

    ohci->eof_timer = qemu_new_timer(vm_clock,

                    ohci_frame_boundary,

                    ohci);

    if (ohci->eof_timer == NULL) {

        fprintf(stderr, "usb-ohci: %s: qemu_new_timer failed\n", ohci->name);

        /* TODO: Signal unrecoverable error */

        return 0;

    }

    dprintf("usb-ohci: %s: USB Operational\n", ohci->name);

    ohci_sof(ohci);

    return 1;

}

/* Stop sending SOF tokens on the bus */

static void ohci_bus_stop(OHCIState *ohci)

{

    if (ohci->eof_timer)

        qemu_del_timer(ohci->eof_timer);

}

/* Sets a flag in a port status register but only set it if the port is

 * connected, if not set ConnectStatusChange flag. If flag is enabled

 * return 1.

 */

static int ohci_port_set_if_connected(OHCIState *ohci, int i, uint32_t val)

{

    int ret = 1;

    /* writing a 0 has no effect */

    if (val == 0)

        return 0;

    /* If CurrentConnectStatus is cleared we set

     * ConnectStatusChange

     */

    if (!(ohci->rhport[i].ctrl & OHCI_PORT_CCS)) {

        ohci->rhport[i].ctrl |= OHCI_PORT_CSC;

        if (ohci->rhstatus & OHCI_RHS_DRWE) {

            /* TODO: CSC is a wakeup event */

        }

        return 0;

    }

    if (ohci->rhport[i].ctrl & val)

        ret = 0;

    /* set the bit */

    ohci->rhport[i].ctrl |= val;

    return ret;

}

/* Set the frame interval - frame interval toggle is manipulated by the hcd only */

static void ohci_set_frame_interval(OHCIState *ohci, uint16_t val)

{

    val &= OHCI_FMI_FI;

    if (val != ohci->fi) {

        dprintf("usb-ohci: %s: FrameInterval = 0x%x (%u)\n",