Merge with Linux 2.5.48.

[linux-2.6/linux-mips.git] / drivers / usb / core / hcd.c

/*
 * (C) Copyright Linus Torvalds 1999
 * (C) Copyright Johannes Erdfelt 1999-2001
 * (C) Copyright Andreas Gal 1999
 * (C) Copyright Gregory P. Smith 1999
 * (C) Copyright Deti Fliegl 1999
 * (C) Copyright Randy Dunlap 2000
 * (C) Copyright David Brownell 2000-2002
 * 
 * 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 of the License, or (at your
 * option) any later version.
 *
 * 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, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>

#ifdef CONFIG_USB_DEBUG
#define DEBUG
#endif

#include <linux/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/uts.h>                  /* for UTS_SYSNAME */
#include <linux/pci.h>                  /* for hcd->pdev and dma addressing */
#include <asm/byteorder.h>

#include <linux/usb.h>
#include "hcd.h"


// #define USB_BANDWIDTH_MESSAGES

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

/*
 * USB Host Controller Driver framework
 *
 * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
 * HCD-specific behaviors/bugs.
 *
 * This does error checks, tracks devices and urbs, and delegates to a
 * "hc_driver" only for code (and data) that really needs to know about
 * hardware differences.  That includes root hub registers, i/o queues,
 * and so on ... but as little else as possible.
 *
 * Shared code includes most of the "root hub" code (these are emulated,
 * though each HC's hardware works differently) and PCI glue, plus request
 * tracking overhead.  The HCD code should only block on spinlocks or on
 * hardware handshaking; blocking on software events (such as other kernel
 * threads releasing resources, or completing actions) is all generic.
 *
 * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
 * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
 * only by the hub driver ... and that neither should be seen or used by
 * usb client device drivers.
 *
 * Contributors of ideas or unattributed patches include: David Brownell,
 * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
 *
 * HISTORY:
 * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
 *              associated cleanup.  "usb_hcd" still != "usb_bus".
 * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
 */

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

/* host controllers we manage */
LIST_HEAD (usb_bus_list);

/* used when allocating bus numbers */
#define USB_MAXBUS              64
struct usb_busmap {
        unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
};
static struct usb_busmap busmap;

/* used when updating list of hcds */
DECLARE_MUTEX (usb_bus_list_lock);      /* exported only for usbfs */

/* used when updating hcd data */
static spinlock_t hcd_data_lock = SPIN_LOCK_UNLOCKED;

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

/*
 * Sharable chunks of root hub code.
 */

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

#define KERNEL_REL      ((LINUX_VERSION_CODE >> 16) & 0x0ff)
#define KERNEL_VER      ((LINUX_VERSION_CODE >> 8) & 0x0ff)

/* usb 2.0 root hub device descriptor */
static const u8 usb2_rh_dev_descriptor [18] = {
        0x12,       /*  __u8  bLength; */
        0x01,       /*  __u8  bDescriptorType; Device */
        0x00, 0x02, /*  __u16 bcdUSB; v2.0 */

        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
        0x00,       /*  __u8  bDeviceSubClass; */
        0x01,       /*  __u8  bDeviceProtocol; [ usb 2.0 single TT ]*/
        0x08,       /*  __u8  bMaxPacketSize0; 8 Bytes */

        0x00, 0x00, /*  __u16 idVendor; */
        0x00, 0x00, /*  __u16 idProduct; */
        KERNEL_VER, KERNEL_REL, /*  __u16 bcdDevice */

        0x03,       /*  __u8  iManufacturer; */
        0x02,       /*  __u8  iProduct; */
        0x01,       /*  __u8  iSerialNumber; */
        0x01        /*  __u8  bNumConfigurations; */
};

/* no usb 2.0 root hub "device qualifier" descriptor: one speed only */

/* usb 1.1 root hub device descriptor */
static const u8 usb11_rh_dev_descriptor [18] = {
        0x12,       /*  __u8  bLength; */
        0x01,       /*  __u8  bDescriptorType; Device */
        0x10, 0x01, /*  __u16 bcdUSB; v1.1 */

        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
        0x00,       /*  __u8  bDeviceSubClass; */
        0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
        0x08,       /*  __u8  bMaxPacketSize0; 8 Bytes */

        0x00, 0x00, /*  __u16 idVendor; */
        0x00, 0x00, /*  __u16 idProduct; */
        KERNEL_VER, KERNEL_REL, /*  __u16 bcdDevice */

        0x03,       /*  __u8  iManufacturer; */
        0x02,       /*  __u8  iProduct; */
        0x01,       /*  __u8  iSerialNumber; */
        0x01        /*  __u8  bNumConfigurations; */
};


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

/* Configuration descriptors for our root hubs */

static const u8 fs_rh_config_descriptor [] = {

        /* one configuration */
        0x09,       /*  __u8  bLength; */
        0x02,       /*  __u8  bDescriptorType; Configuration */
        0x19, 0x00, /*  __u16 wTotalLength; */
        0x01,       /*  __u8  bNumInterfaces; (1) */
        0x01,       /*  __u8  bConfigurationValue; */
        0x00,       /*  __u8  iConfiguration; */
        0x40,       /*  __u8  bmAttributes; 
                                 Bit 7: Bus-powered,
                                     6: Self-powered,
                                     5 Remote-wakwup,
                                     4..0: resvd */
        0x00,       /*  __u8  MaxPower; */
      
        /* USB 1.1:
         * USB 2.0, single TT organization (mandatory):
         *      one interface, protocol 0
         *
         * USB 2.0, multiple TT organization (optional):
         *      two interfaces, protocols 1 (like single TT)
         *      and 2 (multiple TT mode) ... config is
         *      sometimes settable
         *      NOT IMPLEMENTED
         */

        /* one interface */
        0x09,       /*  __u8  if_bLength; */
        0x04,       /*  __u8  if_bDescriptorType; Interface */
        0x00,       /*  __u8  if_bInterfaceNumber; */
        0x00,       /*  __u8  if_bAlternateSetting; */
        0x01,       /*  __u8  if_bNumEndpoints; */
        0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
        0x00,       /*  __u8  if_bInterfaceSubClass; */
        0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
        0x00,       /*  __u8  if_iInterface; */
     
        /* one endpoint (status change endpoint) */
        0x07,       /*  __u8  ep_bLength; */
        0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
        0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
        0x03,       /*  __u8  ep_bmAttributes; Interrupt */
        0x02, 0x00, /*  __u16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
        0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
};

static const u8 hs_rh_config_descriptor [] = {

        /* one configuration */
        0x09,       /*  __u8  bLength; */
        0x02,       /*  __u8  bDescriptorType; Configuration */
        0x19, 0x00, /*  __u16 wTotalLength; */
        0x01,       /*  __u8  bNumInterfaces; (1) */
        0x01,       /*  __u8  bConfigurationValue; */
        0x00,       /*  __u8  iConfiguration; */
        0x40,       /*  __u8  bmAttributes; 
                                 Bit 7: Bus-powered,
                                     6: Self-powered,
                                     5 Remote-wakwup,
                                     4..0: resvd */
        0x00,       /*  __u8  MaxPower; */
      
        /* USB 1.1:
         * USB 2.0, single TT organization (mandatory):
         *      one interface, protocol 0
         *
         * USB 2.0, multiple TT organization (optional):
         *      two interfaces, protocols 1 (like single TT)
         *      and 2 (multiple TT mode) ... config is
         *      sometimes settable
         *      NOT IMPLEMENTED
         */

        /* one interface */
        0x09,       /*  __u8  if_bLength; */
        0x04,       /*  __u8  if_bDescriptorType; Interface */
        0x00,       /*  __u8  if_bInterfaceNumber; */
        0x00,       /*  __u8  if_bAlternateSetting; */
        0x01,       /*  __u8  if_bNumEndpoints; */
        0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
        0x00,       /*  __u8  if_bInterfaceSubClass; */
        0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
        0x00,       /*  __u8  if_iInterface; */
     
        /* one endpoint (status change endpoint) */
        0x07,       /*  __u8  ep_bLength; */
        0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
        0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
        0x03,       /*  __u8  ep_bmAttributes; Interrupt */
        0x02, 0x00, /*  __u16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
        0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
};

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

/*
 * helper routine for returning string descriptors in UTF-16LE
 * input can actually be ISO-8859-1; ASCII is its 7-bit subset
 */
static int ascii2utf (char *s, u8 *utf, int utfmax)
{
        int retval;

        for (retval = 0; *s && utfmax > 1; utfmax -= 2, retval += 2) {
                *utf++ = *s++;
                *utf++ = 0;
        }
        return retval;
}

/*
 * rh_string - provides manufacturer, product and serial strings for root hub
 * @id: the string ID number (1: serial number, 2: product, 3: vendor)
 * @hcd: the host controller for this root hub
 * @type: string describing our driver 
 * @data: return packet in UTF-16 LE
 * @len: length of the return packet
 *
 * Produces either a manufacturer, product or serial number string for the
 * virtual root hub device.
 */
static int rh_string (
        int             id,
        struct usb_hcd  *hcd,
        u8              *data,
        int             len
) {
        char buf [100];

        // language ids
        if (id == 0) {
                *data++ = 4; *data++ = 3;       /* 4 bytes string data */
                *data++ = 0x09; *data++ = 0x04; /* MSFT-speak for "en-us" */
                return 4;

        // serial number
        } else if (id == 1) {
                strcpy (buf, hcd->self.bus_name);

        // product description
        } else if (id == 2) {
                strcpy (buf, hcd->product_desc);

        // id 3 == vendor description
        } else if (id == 3) {
                sprintf (buf, "%s %s %s", UTS_SYSNAME, UTS_RELEASE,
                        hcd->description);

        // unsupported IDs --> "protocol stall"
        } else
            return 0;

        data [0] = 2 + ascii2utf (buf, data + 2, len - 2);
        data [1] = 3;   /* type == string */
        return data [0];
}


/* Root hub control transfers execute synchronously */
static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
{
        struct usb_ctrlrequest *cmd = (struct usb_ctrlrequest *) urb->setup_packet;
        u16             typeReq, wValue, wIndex, wLength;
        const u8        *bufp = 0;
        u8              *ubuf = urb->transfer_buffer;
        int             len = 0;

        typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
        wValue   = le16_to_cpu (cmd->wValue);
        wIndex   = le16_to_cpu (cmd->wIndex);
        wLength  = le16_to_cpu (cmd->wLength);

        if (wLength > urb->transfer_buffer_length)
                goto error;

        /* set up for success */
        urb->status = 0;
        urb->actual_length = wLength;
        switch (typeReq) {

        /* DEVICE REQUESTS */

        case DeviceRequest | USB_REQ_GET_STATUS:
                // DEVICE_REMOTE_WAKEUP
                ubuf [0] = 1; // selfpowered
                ubuf [1] = 0;
                        /* FALLTHROUGH */
        case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
        case DeviceOutRequest | USB_REQ_SET_FEATURE:
                dbg ("no device features yet yet");
                break;
        case DeviceRequest | USB_REQ_GET_CONFIGURATION:
                ubuf [0] = 1;
                        /* FALLTHROUGH */
        case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
                break;
        case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
                switch (wValue & 0xff00) {
                case USB_DT_DEVICE << 8:
                        if (hcd->driver->flags & HCD_USB2)
                                bufp = usb2_rh_dev_descriptor;
                        else if (hcd->driver->flags & HCD_USB11)
                                bufp = usb11_rh_dev_descriptor;
                        else
                                goto error;
                        len = 18;
                        break;
                case USB_DT_CONFIG << 8:
                        if (hcd->driver->flags & HCD_USB2) {
                                bufp = hs_rh_config_descriptor;
                                len = sizeof hs_rh_config_descriptor;
                        } else {
                                bufp = fs_rh_config_descriptor;
                                len = sizeof fs_rh_config_descriptor;
                        }
                        break;
                case USB_DT_STRING << 8:
                        urb->actual_length = rh_string (
                                wValue & 0xff, hcd,
                                ubuf, wLength);
                        break;
                default:
                        goto error;
                }
                break;
        case DeviceRequest | USB_REQ_GET_INTERFACE:
                ubuf [0] = 0;
                        /* FALLTHROUGH */
        case DeviceOutRequest | USB_REQ_SET_INTERFACE:
                break;
        case DeviceOutRequest | USB_REQ_SET_ADDRESS:
                // wValue == urb->dev->devaddr
                dbg ("%s root hub device address %d",
                        hcd->self.bus_name, wValue);
                break;

        /* INTERFACE REQUESTS (no defined feature/status flags) */

        /* ENDPOINT REQUESTS */

        case EndpointRequest | USB_REQ_GET_STATUS:
                // ENDPOINT_HALT flag
                ubuf [0] = 0;
                ubuf [1] = 0;
                        /* FALLTHROUGH */
        case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
        case EndpointOutRequest | USB_REQ_SET_FEATURE:
                dbg ("no endpoint features yet");
                break;

        /* CLASS REQUESTS (and errors) */

        default:
                /* non-generic request */
                urb->status = hcd->driver->hub_control (hcd,
                        typeReq, wValue, wIndex,
                        ubuf, wLength);
                break;
error:
                /* "protocol stall" on error */
                urb->status = -EPIPE;
                dbg ("unsupported hub control message (maxchild %d)",
                                urb->dev->maxchild);
        }
        if (urb->status) {
                urb->actual_length = 0;
                dbg ("CTRL: TypeReq=0x%x val=0x%x idx=0x%x len=%d ==> %d",
                        typeReq, wValue, wIndex, wLength, urb->status);
        }
        if (bufp) {
                if (urb->transfer_buffer_length < len)
                        len = urb->transfer_buffer_length;
                urb->actual_length = len;
                // always USB_DIR_IN, toward host
                memcpy (ubuf, bufp, len);
        }

        /* any errors get returned through the urb completion */
        usb_hcd_giveback_urb (hcd, urb);
        return 0;
}

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

/*
 * Root Hub interrupt transfers are synthesized with a timer.
 * Completions are called in_interrupt() but not in_irq().
 */

static void rh_report_status (unsigned long ptr);

static int rh_status_urb (struct usb_hcd *hcd, struct urb *urb) 
{
        int     len = 1 + (urb->dev->maxchild / 8);

        /* rh_timer protected by hcd_data_lock */
        if (timer_pending (&hcd->rh_timer)
                        || urb->status != -EINPROGRESS
                        || urb->transfer_buffer_length < len) {
                dbg ("not queuing status urb, stat %d", urb->status);
                return -EINVAL;
        }

        urb->hcpriv = hcd;      /* nonzero to indicate it's queued */
        init_timer (&hcd->rh_timer);
        hcd->rh_timer.function = rh_report_status;
        hcd->rh_timer.data = (unsigned long) urb;
        /* USB 2.0 spec says 256msec; this is close enough */
        hcd->rh_timer.expires = jiffies + HZ/4;
        add_timer (&hcd->rh_timer);
        return 0;
}

/* timer callback */

static void rh_report_status (unsigned long ptr)
{
        struct urb      *urb;
        struct usb_hcd  *hcd;
        int             length;
        unsigned long   flags;

        urb = (struct urb *) ptr;
        spin_lock_irqsave (&urb->lock, flags);
        if (!urb->dev) {
                spin_unlock_irqrestore (&urb->lock, flags);
                return;
        }

        hcd = urb->dev->bus->hcpriv;
        if (urb->status == -EINPROGRESS) {
                if (HCD_IS_RUNNING (hcd->state)) {
                        length = hcd->driver->hub_status_data (hcd,
                                        urb->transfer_buffer);
                        spin_unlock_irqrestore (&urb->lock, flags);
                        if (length > 0) {
                                urb->actual_length = length;
                                urb->status = 0;
                                urb->hcpriv = 0;
                                urb->complete (urb);
                                return;
                        }
                } else
                        spin_unlock_irqrestore (&urb->lock, flags);

                /* retrigger timer until completion:  success or unlink */
                spin_lock_irqsave (&hcd_data_lock, flags);
                rh_status_urb (hcd, urb);
                spin_unlock_irqrestore (&hcd_data_lock, flags);
        } else {
                /* this urb's been unlinked */
                urb->hcpriv = 0;
                spin_unlock_irqrestore (&urb->lock, flags);

                usb_hcd_giveback_urb (hcd, urb);
        }
}

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

static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
{
        if (usb_pipeint (urb->pipe)) {
                int             retval;
                unsigned long   flags;

                spin_lock_irqsave (&hcd_data_lock, flags);
                retval = rh_status_urb (hcd, urb);
                spin_unlock_irqrestore (&hcd_data_lock, flags);
                return retval;
        }
        if (usb_pipecontrol (urb->pipe))
                return rh_call_control (hcd, urb);
        else
                return -EINVAL;
}

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

void usb_rh_status_dequeue (struct usb_hcd *hcd, struct urb *urb)
{
        unsigned long   flags;

        spin_lock_irqsave (&hcd_data_lock, flags);
        del_timer_sync (&hcd->rh_timer);
        hcd->rh_timer.data = 0;
        spin_unlock_irqrestore (&hcd_data_lock, flags);

        /* we rely on RH callback code not unlinking its URB! */
        usb_hcd_giveback_urb (hcd, urb);
}

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

/* exported only within usbcore */
void usb_bus_get (struct usb_bus *bus)
{
        atomic_inc (&bus->refcnt);
}

/* exported only within usbcore */
void usb_bus_put (struct usb_bus *bus)
{
        if (atomic_dec_and_test (&bus->refcnt))
                kfree (bus);
}

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

/**
 * usb_bus_init - shared initialization code
 * @bus: the bus structure being initialized
 *
 * This code is used to initialize a usb_bus structure, memory for which is
 * separately managed.
 */
void usb_bus_init (struct usb_bus *bus)
{
        memset (&bus->devmap, 0, sizeof(struct usb_devmap));

        bus->devnum_next = 1;

        bus->root_hub = NULL;
        bus->hcpriv = NULL;
        bus->busnum = -1;
        bus->bandwidth_allocated = 0;
        bus->bandwidth_int_reqs  = 0;
        bus->bandwidth_isoc_reqs = 0;

        INIT_LIST_HEAD (&bus->bus_list);

        atomic_set (&bus->refcnt, 1);
}
EXPORT_SYMBOL (usb_bus_init);

/**
 * usb_alloc_bus - creates a new USB host controller structure
 * @op: pointer to a struct usb_operations that this bus structure should use
 * Context: !in_interrupt()
 *
 * Creates a USB host controller bus structure with the specified 
 * usb_operations and initializes all the necessary internal objects.
 *
 * If no memory is available, NULL is returned.
 *
 * The caller should call usb_free_bus() when it is finished with the structure.
 */
struct usb_bus *usb_alloc_bus (struct usb_operations *op)
{
        struct usb_bus *bus;

        bus = kmalloc (sizeof *bus, GFP_KERNEL);
        if (!bus)
                return NULL;
        usb_bus_init (bus);
        bus->op = op;
        return bus;
}
EXPORT_SYMBOL (usb_alloc_bus);

/**
 * usb_free_bus - frees the memory used by a bus structure
 * @bus: pointer to the bus to free
 *
 * To be invoked by a HCD, only as the last step of decoupling from
 * hardware.  It is an error to call this if the reference count is
 * anything but one.  That would indicate that some system component
 * did not correctly shut down, and thought the hardware was still
 * accessible.
 */
void usb_free_bus (struct usb_bus *bus)
{
        if (!bus)
                return;
        if (atomic_read (&bus->refcnt) != 1)
                err ("usb_free_bus #%d, count != 1", bus->busnum);
        usb_bus_put (bus);
}
EXPORT_SYMBOL (usb_free_bus);

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

/**
 * usb_register_bus - registers the USB host controller with the usb core
 * @bus: pointer to the bus to register
 * Context: !in_interrupt()
 *
 * Assigns a bus number, and links the controller into usbcore data
 * structures so that it can be seen by scanning the bus list.
 */
void usb_register_bus(struct usb_bus *bus)
{
        int busnum;

        down (&usb_bus_list_lock);
        busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
        if (busnum < USB_MAXBUS) {
                set_bit (busnum, busmap.busmap);
                bus->busnum = busnum;
        } else
                warn ("too many buses");

        usb_bus_get (bus);

        /* Add it to the list of buses */
        list_add (&bus->bus_list, &usb_bus_list);
        up (&usb_bus_list_lock);

        usbfs_add_bus (bus);

        info ("new USB bus registered, assigned bus number %d", bus->busnum);
}
EXPORT_SYMBOL (usb_register_bus);

/**
 * usb_deregister_bus - deregisters the USB host controller
 * @bus: pointer to the bus to deregister
 * Context: !in_interrupt()
 *
 * Recycles the bus number, and unlinks the controller from usbcore data
 * structures so that it won't be seen by scanning the bus list.
 */
void usb_deregister_bus (struct usb_bus *bus)
{
        info ("USB bus %d deregistered", bus->busnum);

        /*
         * NOTE: make sure that all the devices are removed by the
         * controller code, as well as having it call this when cleaning
         * itself up
         */
        down (&usb_bus_list_lock);
        list_del (&bus->bus_list);
        up (&usb_bus_list_lock);

        usbfs_remove_bus (bus);

        clear_bit (bus->busnum, busmap.busmap);

        usb_bus_put (bus);
}
EXPORT_SYMBOL (usb_deregister_bus);

/**
 * usb_register_root_hub - called by HCD to register its root hub 
 * @usb_dev: the usb root hub device to be registered.
 * @parent_dev: the parent device of this root hub.
 *
 * The USB host controller calls this function to register the root hub
 * properly with the USB subsystem.  It sets up the device properly in
 * the driverfs tree, and then calls usb_new_device() to register the
 * usb device.
 */
int usb_register_root_hub (struct usb_device *usb_dev, struct device *parent_dev)
{
        int retval;

        sprintf (&usb_dev->dev.bus_id[0], "usb%d", usb_dev->bus->busnum);
        retval = usb_new_device (usb_dev, parent_dev);
        if (retval)
                err("%s - usb_new_device failed with value %d", __FUNCTION__, retval);
        return retval;
}
EXPORT_SYMBOL (usb_register_root_hub);


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

/**
 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
 * @is_input: true iff the transaction sends data to the host
 * @isoc: true for isochronous transactions, false for interrupt ones
 * @bytecount: how many bytes in the transaction.
 *
 * Returns approximate bus time in nanoseconds for a periodic transaction.
 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
 * scheduled in software, this function is only used for such scheduling.
 */
long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
{
        unsigned long   tmp;

        switch (speed) {
        case USB_SPEED_LOW:     /* INTR only */
                if (is_input) {
                        tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
                        return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
                } else {
                        tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
                        return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
                }
        case USB_SPEED_FULL:    /* ISOC or INTR */
                if (isoc) {
                        tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
                        return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
                } else {
                        tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
                        return (9107L + BW_HOST_DELAY + tmp);
                }
        case USB_SPEED_HIGH:    /* ISOC or INTR */
                // FIXME adjust for input vs output
                if (isoc)
                        tmp = HS_USECS (bytecount);
                else
                        tmp = HS_USECS_ISO (bytecount);
                return tmp;
        default:
                dbg ("bogus device speed!");
                return -1;
        }
}
EXPORT_SYMBOL (usb_calc_bus_time);

/*
 * usb_check_bandwidth():
 *
 * old_alloc is from host_controller->bandwidth_allocated in microseconds;
 * bustime is from calc_bus_time(), but converted to microseconds.
 *
 * returns <bustime in us> if successful,
 * or -ENOSPC if bandwidth request fails.
 *
 * FIXME:
 * This initial implementation does not use Endpoint.bInterval
 * in managing bandwidth allocation.
 * It probably needs to be expanded to use Endpoint.bInterval.
 * This can be done as a later enhancement (correction).
 *
 * This will also probably require some kind of
 * frame allocation tracking...meaning, for example,
 * that if multiple drivers request interrupts every 10 USB frames,
 * they don't all have to be allocated at
 * frame numbers N, N+10, N+20, etc.  Some of them could be at
 * N+11, N+21, N+31, etc., and others at
 * N+12, N+22, N+32, etc.
 *
 * Similarly for isochronous transfers...
 *
 * Individual HCDs can schedule more directly ... this logic
 * is not correct for high speed transfers.
 */
int usb_check_bandwidth (struct usb_device *dev, struct urb *urb)
{
        unsigned int    pipe = urb->pipe;
        long            bustime;
        int             is_in = usb_pipein (pipe);
        int             is_iso = usb_pipeisoc (pipe);
        int             old_alloc = dev->bus->bandwidth_allocated;
        int             new_alloc;


        bustime = NS_TO_US (usb_calc_bus_time (dev->speed, is_in, is_iso,
                        usb_maxpacket (dev, pipe, !is_in)));
        if (is_iso)
                bustime /= urb->number_of_packets;

        new_alloc = old_alloc + (int) bustime;
        if (new_alloc > FRAME_TIME_MAX_USECS_ALLOC) {
#ifdef  DEBUG
                char    *mode = 
#ifdef CONFIG_USB_BANDWIDTH
                        "";
#else
                        "would have ";
#endif
                dbg ("usb_check_bandwidth %sFAILED: %d + %ld = %d usec",
                        mode, old_alloc, bustime, new_alloc);
#endif
#ifdef CONFIG_USB_BANDWIDTH
                bustime = -ENOSPC;      /* report error */
#endif
        }

        return bustime;
}
EXPORT_SYMBOL (usb_check_bandwidth);


/**
 * usb_claim_bandwidth - records bandwidth for a periodic transfer
 * @dev: source/target of request
 * @urb: request (urb->dev == dev)
 * @bustime: bandwidth consumed, in (average) microseconds per frame
 * @isoc: true iff the request is isochronous
 *
 * Bus bandwidth reservations are recorded purely for diagnostic purposes.
 * HCDs are expected not to overcommit periodic bandwidth, and to record such
 * reservations whenever endpoints are added to the periodic schedule.
 *
 * FIXME averaging per-frame is suboptimal.  Better to sum over the HCD's
 * entire periodic schedule ... 32 frames for OHCI, 1024 for UHCI, settable
 * for EHCI (256/512/1024 frames, default 1024) and have the bus expose how
 * large its periodic schedule is.
 */
void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb, int bustime, int isoc)
{
        dev->bus->bandwidth_allocated += bustime;
        if (isoc)
                dev->bus->bandwidth_isoc_reqs++;
        else
                dev->bus->bandwidth_int_reqs++;
        urb->bandwidth = bustime;

#ifdef USB_BANDWIDTH_MESSAGES
        dbg ("bandwidth alloc increased by %d (%s) to %d for %d requesters",
                bustime,
                isoc ? "ISOC" : "INTR",
                dev->bus->bandwidth_allocated,
                dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);
#endif
}
EXPORT_SYMBOL (usb_claim_bandwidth);


/**
 * usb_release_bandwidth - reverses effect of usb_claim_bandwidth()
 * @dev: source/target of request
 * @urb: request (urb->dev == dev)
 * @isoc: true iff the request is isochronous
 *
 * This records that previously allocated bandwidth has been released.
 * Bandwidth is released when endpoints are removed from the host controller's
 * periodic schedule.
 */
void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, int isoc)
{
        dev->bus->bandwidth_allocated -= urb->bandwidth;
        if (isoc)
                dev->bus->bandwidth_isoc_reqs--;
        else
                dev->bus->bandwidth_int_reqs--;

#ifdef USB_BANDWIDTH_MESSAGES
        dbg ("bandwidth alloc reduced by %d (%s) to %d for %d requesters",
                urb->bandwidth,
                isoc ? "ISOC" : "INTR",
                dev->bus->bandwidth_allocated,
                dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);
#endif
        urb->bandwidth = 0;
}
EXPORT_SYMBOL (usb_release_bandwidth);


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

/*
 * Generic HC operations.
 */

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

/* called from khubd, or root hub init threads for hcd-private init */
static int hcd_alloc_dev (struct usb_device *udev)
{
        struct hcd_dev          *dev;
        struct usb_hcd          *hcd;
        unsigned long           flags;

        if (!udev || udev->hcpriv)
                return -EINVAL;
        if (!udev->bus || !udev->bus->hcpriv)
                return -ENODEV;
        hcd = udev->bus->hcpriv;
        if (hcd->state == USB_STATE_QUIESCING)
                return -ENOLINK;

        dev = (struct hcd_dev *) kmalloc (sizeof *dev, GFP_KERNEL);
        if (dev == NULL)
                return -ENOMEM;
        memset (dev, 0, sizeof *dev);

        INIT_LIST_HEAD (&dev->dev_list);
        INIT_LIST_HEAD (&dev->urb_list);

        spin_lock_irqsave (&hcd_data_lock, flags);
        list_add (&dev->dev_list, &hcd->dev_list);
        // refcount is implicit
        udev->hcpriv = dev;
        spin_unlock_irqrestore (&hcd_data_lock, flags);

        return 0;
}

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

static void urb_unlink (struct urb *urb)
{
        unsigned long           flags;
        struct usb_device       *dev;

        /* Release any periodic transfer bandwidth */
        if (urb->bandwidth)
                usb_release_bandwidth (urb->dev, urb,
                        usb_pipeisoc (urb->pipe));

        /* clear all state linking urb to this dev (and hcd) */

        spin_lock_irqsave (&hcd_data_lock, flags);
        list_del_init (&urb->urb_list);
        dev = urb->dev;
        usb_put_dev (dev);
        spin_unlock_irqrestore (&hcd_data_lock, flags);
}


/* may be called in any context with a valid urb->dev usecount
 * caller surrenders "ownership" of urb
 * expects usb_submit_urb() to have sanity checked and conditioned all
 * inputs in the urb
 */
static int hcd_submit_urb (struct urb *urb, int mem_flags)
{
        int                     status;
        struct usb_hcd          *hcd = urb->dev->bus->hcpriv;
        struct hcd_dev          *dev = urb->dev->hcpriv;
        unsigned long           flags;

        if (!hcd || !dev)
                return -ENODEV;

        /*
         * FIXME:  make urb timeouts be generic, keeping the HCD cores
         * as simple as possible.
         */

        // NOTE:  a generic device/urb monitoring hook would go here.
        // hcd_monitor_hook(MONITOR_URB_SUBMIT, urb)
        // It would catch submission paths for all urbs.

        /*
         * Atomically queue the urb,  first to our records, then to the HCD.
         * Access to urb->status is controlled by urb->lock ... changes on
         * i/o completion (normal or fault) or unlinking.
         */

        // FIXME:  verify that quiescing hc works right (RH cleans up)

        spin_lock_irqsave (&hcd_data_lock, flags);
        if (HCD_IS_RUNNING (hcd->state) && hcd->state != USB_STATE_QUIESCING) {
                usb_get_dev (urb->dev);
                list_add (&urb->urb_list, &dev->urb_list);
                status = 0;
        } else {
                INIT_LIST_HEAD (&urb->urb_list);
                status = -ESHUTDOWN;
        }
        spin_unlock_irqrestore (&hcd_data_lock, flags);
        if (status)
                return status;

        /* increment urb's reference count as part of giving it to the HCD
         * (which now controls it).  HCD guarantees that it either returns
         * an error or calls giveback(), but not both.
         */
        urb = usb_get_urb (urb);
        if (urb->dev == hcd->self.root_hub) {
                /* NOTE:  requirement on hub callers (usbfs and the hub
                 * driver, for now) that URBs' urb->transfer_buffer be
                 * valid and usb_buffer_{sync,unmap}() not be needed, since
                 * they could clobber root hub response data.
                 */
                urb->transfer_flags |= URB_NO_DMA_MAP;
                return rh_urb_enqueue (hcd, urb);
        }

        /* lower level hcd code should use *_dma exclusively */
        if (!(urb->transfer_flags & URB_NO_DMA_MAP)) {
                if (usb_pipecontrol (urb->pipe))
                        urb->setup_dma = pci_map_single (
                                        hcd->pdev,
                                        urb->setup_packet,
                                        sizeof (struct usb_ctrlrequest),
                                        PCI_DMA_TODEVICE);
                if (urb->transfer_buffer_length != 0)
                        urb->transfer_dma = pci_map_single (
                                        hcd->pdev,
                                        urb->transfer_buffer,
                                        urb->transfer_buffer_length,
                                        usb_pipein (urb->pipe)
                                            ? PCI_DMA_FROMDEVICE
                                            : PCI_DMA_TODEVICE);
        }

        return hcd->driver->urb_enqueue (hcd, urb, mem_flags);
}

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

/* called in any context */
static int hcd_get_frame_number (struct usb_device *udev)
{
        struct usb_hcd  *hcd = (struct usb_hcd *)udev->bus->hcpriv;
        return hcd->driver->get_frame_number (hcd);
}

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

struct completion_splice {              // modified urb context:
        /* did we complete? */
        struct completion       done;

        /* original urb data */
        void                    (*complete)(struct urb *);
        void                    *context;
};

static void unlink_complete (struct urb *urb)
{
        struct completion_splice        *splice;

        splice = (struct completion_splice *) urb->context;

        /* issue original completion call */
        urb->complete = splice->complete;
        urb->context = splice->context;
        urb->complete (urb);

        /* then let the synchronous unlink call complete */
        complete (&splice->done);
}

/*
 * called in any context; note ASYNC_UNLINK restrictions
 *
 * caller guarantees urb won't be recycled till both unlink()
 * and the urb's completion function return
 */
static int hcd_unlink_urb (struct urb *urb)
{
        struct hcd_dev                  *dev;
        struct usb_hcd                  *hcd = 0;
        struct device                   *sys = 0;
        unsigned long                   flags;
        struct completion_splice        splice;
        int                             retval;

        if (!urb)
                return -EINVAL;

        /*
         * we contend for urb->status with the hcd core,
         * which changes it while returning the urb.
         *
         * Caller guaranteed that the urb pointer hasn't been freed, and
         * that it was submitted.  But as a rule it can't know whether or
         * not it's already been unlinked ... so we respect the reversed
         * lock sequence needed for the usb_hcd_giveback_urb() code paths
         * (urb lock, then hcd_data_lock) in case some other CPU is now
         * unlinking it.
         */
        spin_lock_irqsave (&urb->lock, flags);
        spin_lock (&hcd_data_lock);

        if (!urb->dev || !urb->dev->bus) {
                retval = -ENODEV;
                goto done;
        }

        dev = urb->dev->hcpriv;
        sys = &urb->dev->dev;
        hcd = urb->dev->bus->hcpriv;
        if (!dev || !hcd) {
                retval = -ENODEV;
                goto done;
        }

        if (!urb->hcpriv) {
                retval = -EINVAL;
                goto done;
        }

        /* Any status except -EINPROGRESS means something already started to
         * unlink this URB from the hardware.  So there's no more work to do.
         *
         * FIXME use better explicit urb state
         */
        if (urb->status != -EINPROGRESS) {
                retval = -EINVAL;
                goto done;
        }

        /* maybe set up to block until the urb's completion fires.  the
         * lower level hcd code is always async, locking on urb->status
         * updates; an intercepted completion unblocks us.
         */
        if (!(urb->transfer_flags & URB_ASYNC_UNLINK)) {
                if (in_interrupt ()) {
                        dbg ("non-async unlink in_interrupt");
                        retval = -EWOULDBLOCK;
                        goto done;
                }
                /* synchronous unlink: block till we see the completion */
                init_completion (&splice.done);
                splice.complete = urb->complete;
                splice.context = urb->context;
                urb->complete = unlink_complete;
                urb->context = &splice;
                urb->status = -ENOENT;
        } else {
                /* asynchronous unlink */
                urb->status = -ECONNRESET;
        }
        spin_unlock (&hcd_data_lock);
        spin_unlock_irqrestore (&urb->lock, flags);

        if (urb == (struct urb *) hcd->rh_timer.data) {
                usb_rh_status_dequeue (hcd, urb);
                retval = 0;
        } else {
                retval = hcd->driver->urb_dequeue (hcd, urb);

                /* hcds shouldn't really fail these calls, but... */
                if (retval) {
                        dev_dbg (*sys, "dequeue %p --> %d\n", urb, retval);
                        if (!(urb->transfer_flags & URB_ASYNC_UNLINK)) {
                                spin_lock_irqsave (&urb->lock, flags);
                                urb->complete = splice.complete;
                                urb->context = splice.context;
                                spin_unlock_irqrestore (&urb->lock, flags);
                        }
                        goto bye;
                }
        }

        /* block till giveback, if needed */
        if (urb->transfer_flags & URB_ASYNC_UNLINK)
                return -EINPROGRESS;

        dev_dbg (*sys, "wait for giveback urb %p\n", urb);
        wait_for_completion (&splice.done);
        return 0;

done:
        spin_unlock (&hcd_data_lock);
        spin_unlock_irqrestore (&urb->lock, flags);
bye:
        if (retval && sys)
                dev_dbg (*sys, "hcd_unlink_urb %p fail %d\n", urb, retval);
        return retval;
}

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

/* called by khubd, rmmod, apmd, or other thread for hcd-private cleanup */

// FIXME:  likely best to have explicit per-setting (config+alt)
// setup primitives in the usbcore-to-hcd driver API, so nothing
// is implicit.  kernel 2.5 needs a bunch of config cleanup...

static int hcd_free_dev (struct usb_device *udev)
{
        struct hcd_dev          *dev;
        struct usb_hcd          *hcd;
        unsigned long           flags;

        if (!udev || !udev->hcpriv)
                return -EINVAL;

        if (!udev->bus || !udev->bus->hcpriv)
                return -ENODEV;

        // should udev->devnum == -1 ??

        dev = udev->hcpriv;
        hcd = udev->bus->hcpriv;

        /* device driver problem with refcounts? */
        if (!list_empty (&dev->urb_list)) {
                dbg ("free busy dev, %s devnum %d (bug!)",
                        hcd->self.bus_name, udev->devnum);
                return -EINVAL;
        }

        if (hcd->driver->free_config)
                hcd->driver->free_config (hcd, udev);

        spin_lock_irqsave (&hcd_data_lock, flags);
        list_del (&dev->dev_list);
        udev->hcpriv = NULL;
        spin_unlock_irqrestore (&hcd_data_lock, flags);

        kfree (dev);
        return 0;
}

/*
 * usb_hcd_operations - adapts usb_bus framework to HCD framework (bus glue)
 *
 * When registering a USB bus through the HCD framework code, use this
 * usb_operations vector.  The PCI glue layer does so automatically; only
 * bus glue for non-PCI system busses will need to use this.
 */
struct usb_operations usb_hcd_operations = {
        .allocate =             hcd_alloc_dev,
        .get_frame_number =     hcd_get_frame_number,
        .submit_urb =           hcd_submit_urb,
        .unlink_urb =           hcd_unlink_urb,
        .deallocate =           hcd_free_dev,
        .buffer_alloc =         hcd_buffer_alloc,
        .buffer_free =          hcd_buffer_free,
        .buffer_map =           hcd_buffer_map,
        .buffer_dmasync =       hcd_buffer_dmasync,
        .buffer_unmap =         hcd_buffer_unmap,
        .buffer_map_sg =        hcd_buffer_map_sg,
        .buffer_dmasync_sg =    hcd_buffer_sync_sg,
        .buffer_unmap_sg =      hcd_buffer_unmap_sg,
};
EXPORT_SYMBOL (usb_hcd_operations);

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

/**
 * usb_hcd_giveback_urb - return URB from HCD to device driver
 * @hcd: host controller returning the URB
 * @urb: urb being returned to the USB device driver.
 * Context: in_interrupt()
 *
 * This hands the URB from HCD to its USB device driver, using its
 * completion function.  The HCD has freed all per-urb resources
 * (and is done using urb->hcpriv).  It also released all HCD locks;
 * the device driver won't cause problems if it frees, modifies,
 * or resubmits this URB.
 */
void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb)
{
        urb_unlink (urb);

        // NOTE:  a generic device/urb monitoring hook would go here.
        // hcd_monitor_hook(MONITOR_URB_FINISH, urb, dev)
        // It would catch exit/unlink paths for all urbs, but non-exit
        // completions for periodic urbs need hooks inside the HCD.
        // hcd_monitor_hook(MONITOR_URB_UPDATE, urb, dev)

        if (urb->status)
                dbg ("giveback urb %p status %d len %d",
                        urb, urb->status, urb->actual_length);

        /* lower level hcd code should use *_dma exclusively */
        if (!(urb->transfer_flags & URB_NO_DMA_MAP)) {
                if (usb_pipecontrol (urb->pipe))
                        pci_unmap_single (hcd->pdev, urb->setup_dma,
                                        sizeof (struct usb_ctrlrequest),
                                        PCI_DMA_TODEVICE);
                if (urb->transfer_buffer_length != 0)
                        pci_unmap_single (hcd->pdev, urb->transfer_dma,
                                        urb->transfer_buffer_length,
                                        usb_pipein (urb->pipe)
                                            ? PCI_DMA_FROMDEVICE
                                            : PCI_DMA_TODEVICE);
        }

        /* pass ownership to the completion handler */
        urb->complete (urb);
        usb_put_urb (urb);
}
EXPORT_SYMBOL (usb_hcd_giveback_urb);

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

/**
 * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
 * @irq: the IRQ being raised
 * @__hcd: pointer to the HCD whose IRQ is beinng signaled
 * @r: saved hardware registers (not passed to HCD)
 *
 * When registering a USB bus through the HCD framework code, use this
 * to handle interrupts.  The PCI glue layer does so automatically; only
 * bus glue for non-PCI system busses will need to use this.
 */
void usb_hcd_irq (int irq, void *__hcd, struct pt_regs * r)
{
        struct usb_hcd          *hcd = __hcd;
        int                     start = hcd->state;

        if (unlikely (hcd->state == USB_STATE_HALT))    /* irq sharing? */
                return;

        hcd->driver->irq (hcd);
        if (hcd->state != start && hcd->state == USB_STATE_HALT)
                usb_hc_died (hcd);
}
EXPORT_SYMBOL (usb_hcd_irq);

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

/**
 * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
 * @hcd: pointer to the HCD representing the controller
 *
 * This is called by bus glue to report a USB host controller that died
 * while operations may still have been pending.  It's called automatically
 * by the PCI glue, so only glue for non-PCI busses should need to call it. 
 */
void usb_hc_died (struct usb_hcd *hcd)
{
        struct list_head        *devlist, *urblist;
        struct hcd_dev          *dev;
        struct urb              *urb;
        unsigned long           flags;
        
        /* flag every pending urb as done */
        spin_lock_irqsave (&hcd_data_lock, flags);
        list_for_each (devlist, &hcd->dev_list) {
                dev = list_entry (devlist, struct hcd_dev, dev_list);
                list_for_each (urblist, &dev->urb_list) {
                        urb = list_entry (urblist, struct urb, urb_list);
                        dbg ("shutdown %s urb %p pipe %x, current status %d",
                                hcd->self.bus_name, urb, urb->pipe, urb->status);
                        if (urb->status == -EINPROGRESS)
                                urb->status = -ESHUTDOWN;
                }
        }
        urb = (struct urb *) hcd->rh_timer.data;
        if (urb)
                urb->status = -ESHUTDOWN;
        spin_unlock_irqrestore (&hcd_data_lock, flags);

        if (urb)
                usb_rh_status_dequeue (hcd, urb);
        hcd->driver->stop (hcd);
}
EXPORT_SYMBOL (usb_hc_died);