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usb.h

#ifndef __LINUX_USB_H
#define __LINUX_USB_H


#include "usb_ch9.h"

#define USB_MAJOR             180


#ifdef __KERNEL__
#if 0
#include <linux/config.h>
#include <linux/errno.h>        /* for -ENODEV */
#include <linux/delay.h>      /* for mdelay() */
#include <linux/interrupt.h>  /* for in_interrupt() */
#include <linux/list.h>       /* for struct list_head */
#include <linux/device.h>     /* for struct device */
#include <linux/fs.h>         /* for struct file_operations */
#include <linux/completion.h> /* for struct completion */
#include <linux/sched.h>      /* for current && schedule_timeout */


static __inline__ void wait_ms(unsigned int ms)
{
      if(!in_interrupt()) {
            current->state = TASK_UNINTERRUPTIBLE;
            schedule_timeout(1 + ms * HZ / 1000);
      }
      else
            mdelay(ms);
}
#endif
struct usb_device;

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

/*
 * Host-side wrappers for standard USB descriptors ... these are parsed
 * from the data provided by devices.  Parsing turns them from a flat
 * sequence of descriptors into a hierarchy:
 *
 *  - devices have one (usually) or more configs;
 *  - configs have one (often) or more interfaces;
 *  - interfaces have one (usually) or more settings;
 *  - each interface setting has zero or (usually) more endpoints.
 *
 * And there might be other descriptors mixed in with those.
 *
 * Devices may also have class-specific or vendor-specific descriptors.
 */

/* host-side wrapper for parsed endpoint descriptors */
struct usb_host_endpoint {
      struct usb_endpoint_descriptor      desc;

      unsigned char *extra;   /* Extra descriptors */
      int extralen;
};

/* host-side wrapper for one interface setting's parsed descriptors */
struct usb_host_interface {
      struct usb_interface_descriptor     desc;

      /* array of desc.bNumEndpoint endpoints associated with this
       * interface setting.  these will be in no particular order.
       */
      struct usb_host_endpoint *endpoint;

      unsigned char *extra;   /* Extra descriptors */
      int extralen;
};

/**
 * struct usb_interface - what usb device drivers talk to
 * @altsetting: array of interface descriptors, one for each alternate
 *    setting that may be selected.  Each one includes a set of
 *    endpoint configurations and will be in numberic order,
 *    0..num_altsetting.
 * @num_altsetting: number of altsettings defined.
 * @act_altsetting: index of current altsetting.  this number is always
 *    less than num_altsetting.  after the device is configured, each
 *    interface uses its default setting of zero.
 * @max_altsetting:
 * @minor: the minor number assigned to this interface, if this
 *    interface is bound to a driver that uses the USB major number.
 *    If this interface does not use the USB major, this field should
 *    be unused.  The driver should set this value in the probe()
 *    function of the driver, after it has been assigned a minor
 *    number from the USB core by calling usb_register_dev().
 * @dev: driver model's view of this device
 * @class_dev: driver model's class view of this device.
 *
 * USB device drivers attach to interfaces on a physical device.  Each
 * interface encapsulates a single high level function, such as feeding
 * an audio stream to a speaker or reporting a change in a volume control.
 * Many USB devices only have one interface.  The protocol used to talk to
 * an interface's endpoints can be defined in a usb "class" specification,
 * or by a product's vendor.  The (default) control endpoint is part of
 * every interface, but is never listed among the interface's descriptors.
 *
 * The driver that is bound to the interface can use standard driver model
 * calls such as dev_get_drvdata() on the dev member of this structure.
 *
 * Each interface may have alternate settings.  The initial configuration
 * of a device sets the first of these, but the device driver can change
 * that setting using usb_set_interface().  Alternate settings are often
 * used to control the the use of periodic endpoints, such as by having
 * different endpoints use different amounts of reserved USB bandwidth.
 * All standards-conformant USB devices that use isochronous endpoints
 * will use them in non-default settings.
 */
struct usb_interface {
      /* array of alternate settings for this interface.
       * these will be in numeric order, 0..num_altsettting
       */
      struct usb_host_interface *altsetting;

      unsigned act_altsetting;      /* active alternate setting */
      unsigned num_altsetting;      /* number of alternate settings */
      unsigned max_altsetting;      /* total memory allocated */

      struct usb_driver *driver;    /* driver */
      int minor;              /* minor number this interface is bound to */
      struct device dev;            /* interface specific device info */
      struct class_device class_dev;
};
#define     to_usb_interface(d) container_of(d, struct usb_interface, dev)
#define class_dev_to_usb_interface(d) container_of(d, struct usb_interface, class_dev)
#define     interface_to_usbdev(intf) \
      container_of(intf->dev.parent, struct usb_device, dev)

static inline void *usb_get_intfdata (struct usb_interface *intf)
{
      return dev_get_drvdata (&intf->dev);
}

static inline void usb_set_intfdata (struct usb_interface *intf, void *data)
{
      dev_set_drvdata(&intf->dev, data);
}

/* USB_DT_CONFIG: Configuration descriptor information.
 *
 * USB_DT_OTHER_SPEED_CONFIG is the same descriptor, except that the
 * descriptor type is different.  Highspeed-capable devices can look
 * different depending on what speed they're currently running.  Only
 * devices with a USB_DT_DEVICE_QUALIFIER have an OTHER_SPEED_CONFIG.
 */
struct usb_host_config {
      struct usb_config_descriptor  desc;

      /* the interfaces associated with this configuration
       * these will be in numeric order, 0..desc.bNumInterfaces
       */
      struct usb_interface *interface;

      unsigned char *extra;   /* Extra descriptors */
      int extralen;
};

// FIXME remove; exported only for drivers/usb/misc/auserwald.c
// prefer usb_device->epnum[0..31]
extern struct usb_endpoint_descriptor *
      usb_epnum_to_ep_desc(struct usb_device *dev, unsigned epnum);

int __usb_get_extra_descriptor(char *buffer, unsigned size,
      unsigned char type, void **ptr);
#define usb_get_extra_descriptor(ifpoint,type,ptr)\
      __usb_get_extra_descriptor((ifpoint)->extra,(ifpoint)->extralen,\
            type,(void**)ptr)

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

struct usb_operations;

/* USB device number allocation bitmap */
struct usb_devmap {
      unsigned long devicemap[128 / (8*sizeof(unsigned long))];
};

/*
 * Allocated per bus (tree of devices) we have:
 */
struct usb_bus {
      struct device *controller;    /* host/master side hardware */
      int busnum;             /* Bus number (in order of reg) */
      char *bus_name;               /* stable id (PCI slot_name etc) */

      int devnum_next;        /* Next open device number in round-robin allocation */

      struct usb_devmap devmap;     /* device address allocation map */
      struct usb_operations *op;    /* Operations (specific to the HC) */
      struct usb_device *root_hub;  /* Root hub */
      struct list_head bus_list;    /* list of busses */
      void *hcpriv;                   /* Host Controller private data */

      int bandwidth_allocated;      /* on this bus: how much of the time
                               * reserved for periodic (intr/iso)
                               * requests is used, on average?
                               * Units: microseconds/frame.
                               * Limits: Full/low speed reserve 90%,
                               * while high speed reserves 80%.
                               */
      int bandwidth_int_reqs;       /* number of Interrupt requests */
      int bandwidth_isoc_reqs;      /* number of Isoc. requests */

      struct dentry *usbfs_dentry;  /* usbfs dentry entry for the bus */
      struct dentry *usbdevfs_dentry;     /* usbdevfs dentry entry for the bus */

      atomic_t refcnt;
};


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

/* This is arbitrary.
 * From USB 2.0 spec Table 11-13, offset 7, a hub can
 * have up to 255 ports. The most yet reported is 10.
 */
#define USB_MAXCHILDREN       (16)

struct usb_tt;

struct usb_device {
      int         devnum;           /* Address on USB bus */
      char        devpath [16];     /* Use in messages: /port/port/... */
      enum usb_device_state   state;      /* configured, not attached, etc */
      enum usb_device_speed   speed;      /* high/full/low (or error) */

      struct usb_tt     *tt;        /* low/full speed dev, highspeed hub */
      int         ttport;           /* device port on that tt hub */

      struct semaphore serialize;

      unsigned int toggle[2];       /* one bit for each endpoint ([0] = IN, [1] = OUT) */
      unsigned int halted[2];       /* endpoint halts; one bit per endpoint # & direction; */
                              /* [0] = IN, [1] = OUT */
      int epmaxpacketin[16];        /* INput endpoint specific maximums */
      int epmaxpacketout[16];       /* OUTput endpoint specific maximums */

      struct usb_device *parent;    /* our hub, unless we're the root */
      struct usb_bus *bus;          /* Bus we're part of */

      struct device dev;            /* Generic device interface */

      struct usb_device_descriptor descriptor;/* Descriptor */
      struct usb_host_config *config;     /* All of the configs */
      struct usb_host_config *actconfig;/* the active configuration */

      char **rawdescriptors;        /* Raw descriptors for each config */

      int have_langid;        /* whether string_langid is valid yet */
      int string_langid;            /* language ID for strings */

      void *hcpriv;                 /* Host Controller private data */
      
      struct list_head filelist;
      struct dentry *usbfs_dentry;  /* usbfs dentry entry for the device */
      struct dentry *usbdevfs_dentry;     /* usbdevfs dentry entry for the device */

      /*
       * Child devices - these can be either new devices
       * (if this is a hub device), or different instances
       * of this same device.
       *
       * Each instance needs its own set of data structures.
       */

      int maxchild;                 /* Number of ports if hub */
      struct usb_device *children[USB_MAXCHILDREN];
};
#define     to_usb_device(d) container_of(d, struct usb_device, dev)

extern struct usb_device *usb_alloc_dev(struct usb_device *parent, struct usb_bus *);
extern struct usb_device *usb_get_dev(struct usb_device *dev);
extern void usb_put_dev(struct usb_device *dev);

/* mostly for devices emulating SCSI over USB */
extern int usb_reset_device(struct usb_device *dev);

extern struct usb_device *usb_find_device(u16 vendor_id, u16 product_id);

/* for drivers using iso endpoints */
extern int usb_get_current_frame_number (struct usb_device *usb_dev);

/* used these for multi-interface device registration */
extern void usb_driver_claim_interface(struct usb_driver *driver,
                  struct usb_interface *iface, void* priv);
extern int usb_interface_claimed(struct usb_interface *iface);
extern void usb_driver_release_interface(struct usb_driver *driver,
                  struct usb_interface *iface);
const struct usb_device_id *usb_match_id(struct usb_interface *interface,
                               const struct usb_device_id *id);

extern struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor);
extern struct usb_interface *usb_ifnum_to_if(struct usb_device *dev, unsigned ifnum);


/**
 * usb_make_path - returns stable device path in the usb tree
 * @dev: the device whose path is being constructed
 * @buf: where to put the string
 * @size: how big is "buf"?
 *
 * Returns length of the string (> 0) or negative if size was too small.
 *
 * This identifier is intended to be "stable", reflecting physical paths in
 * hardware such as physical bus addresses for host controllers or ports on
 * USB hubs.  That makes it stay the same until systems are physically
 * reconfigured, by re-cabling a tree of USB devices or by moving USB host
 * controllers.  Adding and removing devices, including virtual root hubs
 * in host controller driver modules, does not change these path identifers;
 * neither does rebooting or re-enumerating.  These are more useful identifiers
 * than changeable ("unstable") ones like bus numbers or device addresses.
 *
 * With a partial exception for devices connected to USB 2.0 root hubs, these
 * identifiers are also predictable.  So long as the device tree isn't changed,
 * plugging any USB device into a given hub port always gives it the same path.
 * Because of the use of "companion" controllers, devices connected to ports on
 * USB 2.0 root hubs (EHCI host controllers) will get one path ID if they are
 * high speed, and a different one if they are full or low speed.
 */
static inline int usb_make_path (struct usb_device *dev, char *buf, size_t size)
{
      int actual;
      actual = snprintf (buf, size, "usb-%s-%s", dev->bus->bus_name, dev->devpath);
      return (actual >= size) ? -1 : actual;
}

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

#define USB_DEVICE_ID_MATCH_DEVICE        (USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT)
#define USB_DEVICE_ID_MATCH_DEV_RANGE           (USB_DEVICE_ID_MATCH_DEV_LO | USB_DEVICE_ID_MATCH_DEV_HI)
#define USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION  (USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_RANGE)
#define USB_DEVICE_ID_MATCH_DEV_INFO \
      (USB_DEVICE_ID_MATCH_DEV_CLASS | USB_DEVICE_ID_MATCH_DEV_SUBCLASS | USB_DEVICE_ID_MATCH_DEV_PROTOCOL)
#define USB_DEVICE_ID_MATCH_INT_INFO \
      (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS | USB_DEVICE_ID_MATCH_INT_PROTOCOL)

/**
 * USB_DEVICE - macro used to describe a specific usb device
 * @vend: the 16 bit USB Vendor ID
 * @prod: the 16 bit USB Product ID
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific device.
 */
#define USB_DEVICE(vend,prod) \
      .match_flags = USB_DEVICE_ID_MATCH_DEVICE, .idVendor = (vend), .idProduct = (prod)
/**
 * USB_DEVICE_VER - macro used to describe a specific usb device with a version range
 * @vend: the 16 bit USB Vendor ID
 * @prod: the 16 bit USB Product ID
 * @lo: the bcdDevice_lo value
 * @hi: the bcdDevice_hi value
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific device, with a version range.
 */
#define USB_DEVICE_VER(vend,prod,lo,hi) \
      .match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION, .idVendor = (vend), .idProduct = (prod), .bcdDevice_lo = (lo), .bcdDevice_hi = (hi)

/**
 * USB_DEVICE_INFO - macro used to describe a class of usb devices
 * @cl: bDeviceClass value
 * @sc: bDeviceSubClass value
 * @pr: bDeviceProtocol value
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific class of devices.
 */
#define USB_DEVICE_INFO(cl,sc,pr) \
      .match_flags = USB_DEVICE_ID_MATCH_DEV_INFO, .bDeviceClass = (cl), .bDeviceSubClass = (sc), .bDeviceProtocol = (pr)

/**
 * USB_INTERFACE_INFO - macro used to describe a class of usb interfaces 
 * @cl: bInterfaceClass value
 * @sc: bInterfaceSubClass value
 * @pr: bInterfaceProtocol value
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific class of interfaces.
 */
#define USB_INTERFACE_INFO(cl,sc,pr) \
      .match_flags = USB_DEVICE_ID_MATCH_INT_INFO, .bInterfaceClass = (cl), .bInterfaceSubClass = (sc), .bInterfaceProtocol = (pr)

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

/**
 * struct usb_driver - identifies USB driver to usbcore
 * @owner: Pointer to the module owner of this driver; initialize
 *    it using THIS_MODULE.
 * @name: The driver name should be unique among USB drivers,
 *    and should normally be the same as the module name.
 * @probe: Called to see if the driver is willing to manage a particular
 *    interface on a device.  If it is, probe returns zero and uses
 *    dev_set_drvdata() to associate driver-specific data with the
 *    interface.  It may also use usb_set_interface() to specify the
 *    appropriate altsetting.  If unwilling to manage the interface,
 *    return a negative errno value.
 * @disconnect: Called when the interface is no longer accessible, usually
 *    because its device has been (or is being) disconnected or the
 *    driver module is being unloaded.
 * @ioctl: Used for drivers that want to talk to userspace through
 *    the "usbfs" filesystem.  This lets devices provide ways to
 *    expose information to user space regardless of where they
 *    do (or don't) show up otherwise in the filesystem.
 * @id_table: USB drivers use ID table to support hotplugging.
 *    Export this with MODULE_DEVICE_TABLE(usb,...).  This must be set
 *    or your driver's probe function will never get called. 
 *
 * USB drivers must provide a name, probe() and disconnect() methods,
 * and an id_table.  Other driver fields are optional.
 *
 * The id_table is used in hotplugging.  It holds a set of descriptors,
 * and specialized data may be associated with each entry.  That table
 * is used by both user and kernel mode hotplugging support.
 *
 * The probe() and disconnect() methods are called in a context where
 * they can sleep, but they should avoid abusing the privilege.  Most
 * work to connect to a device should be done when the device is opened,
 * and undone at the last close.  The disconnect code needs to address
 * concurrency issues with respect to open() and close() methods, as
 * well as forcing all pending I/O requests to complete (by unlinking
 * them as necessary, and blocking until the unlinks complete).
 */
struct usb_driver {
      struct module *owner;

      const char *name;

      int (*probe) (struct usb_interface *intf,
                  const struct usb_device_id *id);

      void (*disconnect) (struct usb_interface *intf);

      int (*ioctl) (struct usb_interface *intf, unsigned int code, void *buf);

      const struct usb_device_id *id_table;

      struct device_driver driver;

      struct semaphore serialize;
};
#define     to_usb_driver(d) container_of(d, struct usb_driver, driver)

extern struct bus_type usb_bus_type;

/**
 * struct usb_class_driver - identifies a USB driver that wants to use the USB major number
 * @name: devfs name for this driver.  Will also be used by the driver
 *    class code to create a usb class device.
 * @fops: pointer to the struct file_operations of this driver.
 * @mode: the mode for the devfs file to be created for this driver.
 * @minor_base: the start of the minor range for this driver.
 *
 * This structure is used for the usb_register_dev() and
 * usb_unregister_dev() functions, to consolodate a number of the
 * paramaters used for them.
 */
struct usb_class_driver {
      char *name;
      struct file_operations *fops;
      mode_t mode;
      int minor_base;   
};

/*
 * use these in module_init()/module_exit()
 * and don't forget MODULE_DEVICE_TABLE(usb, ...)
 */
extern int usb_register(struct usb_driver *);
extern void usb_deregister(struct usb_driver *);

extern int usb_register_dev(struct usb_interface *intf,
                      struct usb_class_driver *class_driver);
extern void usb_deregister_dev(struct usb_interface *intf,
                         struct usb_class_driver *class_driver);

extern int usb_device_probe(struct device *dev);
extern int usb_device_remove(struct device *dev);
extern int usb_disabled(void);

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

/*
 * URB support, for asynchronous request completions
 */

/*
 * urb->transfer_flags:
 */
#define URB_SHORT_NOT_OK      0x0001      /* report short reads as errors */
#define URB_ISO_ASAP          0x0002      /* iso-only, urb->start_frame ignored */
#define URB_NO_DMA_MAP        0x0004      /* urb->*_dma are valid on submit */
#define URB_ASYNC_UNLINK      0x0008      /* usb_unlink_urb() returns asap */
#define URB_NO_FSBR           0x0020      /* UHCI-specific */
#define URB_ZERO_PACKET       0x0040      /* Finish bulk OUTs with short packet */
#define URB_NO_INTERRUPT      0x0080      /* HINT: no non-error interrupt needed */

struct usb_iso_packet_descriptor {
      unsigned int offset;
      unsigned int length;          /* expected length */
      unsigned int actual_length;
      unsigned int status;
};

struct urb;
struct pt_regs;

typedef void (*usb_complete_t)(struct urb *, struct pt_regs *);

/**
 * struct urb - USB Request Block
 * @urb_list: For use by current owner of the URB.
 * @pipe: Holds endpoint number, direction, type, and more.
 *    Create these values with the eight macros available;
 *    usb_{snd,rcv}TYPEpipe(dev,endpoint), where the type is "ctrl"
 *    (control), "bulk", "int" (interrupt), or "iso" (isochronous).
 *    For example usb_sndbulkpipe() or usb_rcvintpipe().  Endpoint
 *    numbers range from zero to fifteen.  Note that "in" endpoint two
 *    is a different endpoint (and pipe) from "out" endpoint two.
 *    The current configuration controls the existence, type, and
 *    maximum packet size of any given endpoint.
 * @dev: Identifies the USB device to perform the request.
 * @status: This is read in non-iso completion functions to get the
 *    status of the particular request.  ISO requests only use it
 *    to tell whether the URB was unlinked; detailed status for
 *    each frame is in the fields of the iso_frame-desc.
 * @transfer_flags: A variety of flags may be used to affect how URB
 *    submission, unlinking, or operation are handled.  Different
 *    kinds of URB can use different flags.
 * @transfer_buffer:  This identifies the buffer to (or from) which
 *    the I/O request will be performed (unless URB_NO_DMA_MAP is set).
 *    This buffer must be suitable for DMA; allocate it with kmalloc()
 *    or equivalent.  For transfers to "in" endpoints, contents of
 *    this buffer will be modified.  This buffer is used for data
 *    phases of control transfers.
 * @transfer_dma: When transfer_flags includes URB_NO_DMA_MAP, the device
 *    driver is saying that it provided this DMA address, which the host
 *    controller driver should use instead of the transfer_buffer.
 * @transfer_buffer_length: How big is transfer_buffer.  The transfer may
 *    be broken up into chunks according to the current maximum packet
 *    size for the endpoint, which is a function of the configuration
 *    and is encoded in the pipe.  When the length is zero, neither
 *    transfer_buffer nor transfer_dma is used.
 * @actual_length: This is read in non-iso completion functions, and
 *    it tells how many bytes (out of transfer_buffer_length) were
 *    transferred.  It will normally be the same as requested, unless
 *    either an error was reported or a short read was performed.
 *    The URB_SHORT_NOT_OK transfer flag may be used to make such
 *    short reads be reported as errors. 
 * @setup_packet: Only used for control transfers, this points to eight bytes
 *    of setup data.  Control transfers always start by sending this data
 *    to the device.  Then transfer_buffer is read or written, if needed.
 *    (Not used when URB_NO_DMA_MAP is set.)
 * @setup_dma: For control transfers with URB_NO_DMA_MAP set, the device
 *    driver has provided this DMA address for the setup packet.  The
 *    host controller driver should use this instead of setup_buffer.
 *    If there is a data phase, its buffer is identified by transfer_dma.
 * @start_frame: Returns the initial frame for interrupt or isochronous
 *    transfers.
 * @number_of_packets: Lists the number of ISO transfer buffers.
 * @interval: Specifies the polling interval for interrupt or isochronous
 *    transfers.  The units are frames (milliseconds) for for full and low
 *    speed devices, and microframes (1/8 millisecond) for highspeed ones.
 * @error_count: Returns the number of ISO transfers that reported errors.
 * @context: For use in completion functions.  This normally points to
 *    request-specific driver context.
 * @complete: Completion handler. This URB is passed as the parameter to the
 *    completion function.  The completion function may then do what
 *    it likes with the URB, including resubmitting or freeing it.
 * @iso_frame_desc: Used to provide arrays of ISO transfer buffers and to 
 *    collect the transfer status for each buffer.
 *
 * This structure identifies USB transfer requests.  URBs must be allocated by
 * calling usb_alloc_urb() and freed with a call to usb_free_urb().
 * Initialization may be done using various usb_fill_*_urb() functions.  URBs
 * are submitted using usb_submit_urb(), and pending requests may be canceled
 * using usb_unlink_urb().
 *
 * Data Transfer Buffers:
 *
 * Normally drivers provide I/O buffers allocated with kmalloc() or otherwise
 * taken from the general page pool.  That is provided by transfer_buffer
 * (control requests also use setup_packet), and host controller drivers
 * perform a dma mapping (and unmapping) for each buffer transferred.  Those
 * mapping operations can be expensive on some platforms (perhaps using a dma
 * bounce buffer or talking to an IOMMU),
 * although they're cheap on commodity x86 and ppc hardware.
 *
 * Alternatively, drivers may pass the URB_NO_DMA_MAP transfer flag, which
 * tells the host controller driver that no such mapping is needed since
 * the device driver is DMA-aware.  For example, they might allocate a DMA
 * buffer with usb_buffer_alloc(), or call usb_buffer_map().
 * When this transfer flag is provided, host controller drivers will use the
 * dma addresses found in the transfer_dma and/or setup_dma fields rather than
 * determing a dma address themselves.
 *
 * Initialization:
 *
 * All URBs submitted must initialize dev, pipe,
 * transfer_flags (may be zero), complete, timeout (may be zero).
 * The URB_ASYNC_UNLINK transfer flag affects later invocations of
 * the usb_unlink_urb() routine.
 *
 * All URBs must also initialize 
 * transfer_buffer and transfer_buffer_length.  They may provide the
 * URB_SHORT_NOT_OK transfer flag, indicating that short reads are
 * to be treated as errors; that flag is invalid for write requests.
 *
 * Bulk URBs may
 * use the URB_ZERO_PACKET transfer flag, indicating that bulk OUT transfers
 * should always terminate with a short packet, even if it means adding an
 * extra zero length packet.
 *
 * Control URBs must provide a setup_packet.
 *
 * Interrupt UBS must provide an interval, saying how often (in milliseconds
 * or, for highspeed devices, 125 microsecond units)
 * to poll for transfers.  After the URB has been submitted, the interval
 * and start_frame fields reflect how the transfer was actually scheduled.
 * The polling interval may be more frequent than requested.
 * For example, some controllers have a maximum interval of 32 microseconds,
 * while others support intervals of up to 1024 microseconds.
 * Isochronous URBs also have transfer intervals.  (Note that for isochronous
 * endpoints, as well as high speed interrupt endpoints, the encoding of
 * the transfer interval in the endpoint descriptor is logarithmic.)
 *
 * Isochronous URBs normally use the URB_ISO_ASAP transfer flag, telling
 * the host controller to schedule the transfer as soon as bandwidth
 * utilization allows, and then set start_frame to reflect the actual frame
 * selected during submission.  Otherwise drivers must specify the start_frame
 * and handle the case where the transfer can't begin then.  However, drivers
 * won't know how bandwidth is currently allocated, and while they can
 * find the current frame using usb_get_current_frame_number () they can't
 * know the range for that frame number.  (Ranges for frame counter values
 * are HC-specific, and can go from 256 to 65536 frames from "now".)
 *
 * Isochronous URBs have a different data transfer model, in part because
 * the quality of service is only "best effort".  Callers provide specially
 * allocated URBs, with number_of_packets worth of iso_frame_desc structures
 * at the end.  Each such packet is an individual ISO transfer.  Isochronous
 * URBs are normally queued, submitted by drivers to arrange that
 * transfers are at least double buffered, and then explicitly resubmitted
 * in completion handlers, so
 * that data (such as audio or video) streams at as constant a rate as the
 * host controller scheduler can support.
 *
 * Completion Callbacks:
 *
 * The completion callback is made in_interrupt(), and one of the first
 * things that a completion handler should do is check the status field.
 * The status field is provided for all URBs.  It is used to report
 * unlinked URBs, and status for all non-ISO transfers.  It should not
 * be examined before the URB is returned to the completion handler.
 *
 * The context field is normally used to link URBs back to the relevant
 * driver or request state.
 *
 * When completion callback is invoked for non-isochronous URBs, the
 * actual_length field tells how many bytes were transferred.
 *
 * ISO transfer status is reported in the status and actual_length fields
 * of the iso_frame_desc array, and the number of errors is reported in
 * error_count.  Completion callbacks for ISO transfers will normally
 * (re)submit URBs to ensure a constant transfer rate.
 */
struct urb
{
      spinlock_t lock;        /* lock for the URB */
      atomic_t count;               /* reference count of the URB */
      void *hcpriv;                 /* private data for host controller */
      struct list_head urb_list;    /* list pointer to all active urbs */
      struct usb_device *dev;       /* (in) pointer to associated device */
      unsigned int pipe;            /* (in) pipe information */
      int status;             /* (return) non-ISO status */
      unsigned int transfer_flags;  /* (in) URB_SHORT_NOT_OK | ...*/
      void *transfer_buffer;        /* (in) associated data buffer */
      dma_addr_t transfer_dma;      /* (in) dma addr for transfer_buffer */
      int transfer_buffer_length;   /* (in) data buffer length */
      int actual_length;            /* (return) actual transfer length */
      int bandwidth;                /* bandwidth for INT/ISO request */
      unsigned char *setup_packet;  /* (in) setup packet (control only) */
      dma_addr_t setup_dma;         /* (in) dma addr for setup_packet */
      int start_frame;        /* (modify) start frame (INT/ISO) */
      int number_of_packets;        /* (in) number of ISO packets */
      int interval;                 /* (in) transfer interval (INT/ISO) */
      int error_count;        /* (return) number of ISO errors */
      int timeout;                  /* (in) timeout, in jiffies */
      void *context;                /* (in) context for completion */
      usb_complete_t complete;      /* (in) completion routine */
      struct usb_iso_packet_descriptor iso_frame_desc[0];   /* (in) ISO ONLY */
};

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

/**
 * usb_fill_control_urb - initializes a control urb
 * @urb: pointer to the urb to initialize.
 * @dev: pointer to the struct usb_device for this urb.
 * @pipe: the endpoint pipe
 * @setup_packet: pointer to the setup_packet buffer
 * @transfer_buffer: pointer to the transfer buffer
 * @buffer_length: length of the transfer buffer
 * @complete: pointer to the usb_complete_t function
 * @context: what to set the urb context to.
 *
 * Initializes a control urb with the proper information needed to submit
 * it to a device.
 */
static inline void usb_fill_control_urb (struct urb *urb,
                               struct usb_device *dev,
                               unsigned int pipe,
                               unsigned char *setup_packet,
                               void *transfer_buffer,
                               int buffer_length,
                               usb_complete_t complete,
                               void *context)
{
      spin_lock_init(&urb->lock);
      urb->dev = dev;
      urb->pipe = pipe;
      urb->setup_packet = setup_packet;
      urb->transfer_buffer = transfer_buffer;
      urb->transfer_buffer_length = buffer_length;
      urb->complete = complete;
      urb->context = context;
}

/**
 * usb_fill_bulk_urb - macro to help initialize a bulk urb
 * @urb: pointer to the urb to initialize.
 * @dev: pointer to the struct usb_device for this urb.
 * @pipe: the endpoint pipe
 * @transfer_buffer: pointer to the transfer buffer
 * @buffer_length: length of the transfer buffer
 * @complete: pointer to the usb_complete_t function
 * @context: what to set the urb context to.
 *
 * Initializes a bulk urb with the proper information needed to submit it
 * to a device.
 */
static inline void usb_fill_bulk_urb (struct urb *urb,
                              struct usb_device *dev,
                              unsigned int pipe,
                              void *transfer_buffer,
                              int buffer_length,
                              usb_complete_t complete,
                              void *context)
{
      spin_lock_init(&urb->lock);
      urb->dev = dev;
      urb->pipe = pipe;
      urb->transfer_buffer = transfer_buffer;
      urb->transfer_buffer_length = buffer_length;
      urb->complete = complete;
      urb->context = context;
}

/**
 * usb_fill_int_urb - macro to help initialize a interrupt urb
 * @urb: pointer to the urb to initialize.
 * @dev: pointer to the struct usb_device for this urb.
 * @pipe: the endpoint pipe
 * @transfer_buffer: pointer to the transfer buffer
 * @buffer_length: length of the transfer buffer
 * @complete: pointer to the usb_complete_t function
 * @context: what to set the urb context to.
 * @interval: what to set the urb interval to, encoded like
 *    the endpoint descriptor's bInterval value.
 *
 * Initializes a interrupt urb with the proper information needed to submit
 * it to a device.
 * Note that high speed interrupt endpoints use a logarithmic encoding of
 * the endpoint interval, and express polling intervals in microframes
 * (eight per millisecond) rather than in frames (one per millisecond).
 */
static inline void usb_fill_int_urb (struct urb *urb,
                             struct usb_device *dev,
                             unsigned int pipe,
                             void *transfer_buffer,
                             int buffer_length,
                             usb_complete_t complete,
                             void *context,
                             int interval)
{
      spin_lock_init(&urb->lock);
      urb->dev = dev;
      urb->pipe = pipe;
      urb->transfer_buffer = transfer_buffer;
      urb->transfer_buffer_length = buffer_length;
      urb->complete = complete;
      urb->context = context;
      if (dev->speed == USB_SPEED_HIGH)
            urb->interval = 1 << (interval - 1);
      else
            urb->interval = interval;
      urb->start_frame = -1;
}

extern void usb_init_urb(struct urb *urb);
extern struct urb *usb_alloc_urb(int iso_packets, int mem_flags);
extern void usb_free_urb(struct urb *urb);
#define usb_put_urb usb_free_urb
extern struct urb *usb_get_urb(struct urb *urb);
extern int usb_submit_urb(struct urb *urb, int mem_flags);
extern int usb_unlink_urb(struct urb *urb);

#define HAVE_USB_BUFFERS
void *usb_buffer_alloc (struct usb_device *dev, size_t size,
      int mem_flags, dma_addr_t *dma);
void usb_buffer_free (struct usb_device *dev, size_t size,
      void *addr, dma_addr_t dma);

struct urb *usb_buffer_map (struct urb *urb);
void usb_buffer_dmasync (struct urb *urb);
void usb_buffer_unmap (struct urb *urb);

struct scatterlist;
int usb_buffer_map_sg (struct usb_device *dev, unsigned pipe,
            struct scatterlist *sg, int nents);
void usb_buffer_dmasync_sg (struct usb_device *dev, unsigned pipe,
            struct scatterlist *sg, int n_hw_ents);
void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe,
            struct scatterlist *sg, int n_hw_ents);

/*-------------------------------------------------------------------*
 *                         SYNCHRONOUS CALL SUPPORT                  *
 *-------------------------------------------------------------------*/

extern int usb_control_msg(struct usb_device *dev, unsigned int pipe,
      __u8 request, __u8 requesttype, __u16 value, __u16 index,
      void *data, __u16 size, int timeout);
extern int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
      void *data, int len, int *actual_length,
      int timeout);

/* wrappers around usb_control_msg() for the most common standard requests */
extern int usb_get_descriptor(struct usb_device *dev, unsigned char desctype,
      unsigned char descindex, void *buf, int size);
extern int usb_get_device_descriptor(struct usb_device *dev);
extern int usb_get_status(struct usb_device *dev,
      int type, int target, void *data);
extern int usb_get_string(struct usb_device *dev,
      unsigned short langid, unsigned char index, void *buf, int size);
extern int usb_string(struct usb_device *dev, int index,
      char *buf, size_t size);

/* wrappers that also update important state inside usbcore */
extern int usb_clear_halt(struct usb_device *dev, int pipe);
extern int usb_set_configuration(struct usb_device *dev, int configuration);
extern int usb_set_interface(struct usb_device *dev, int ifnum, int alternate);

/*
 * timeouts, in seconds, used for sending/receiving control messages
 * they typically complete within a few frames (msec) after they're issued
 * USB identifies 5 second timeouts, maybe more in a few cases, and a few
 * slow devices (like some MGE Ellipse UPSes) actually push that limit.
 */
#define USB_CTRL_GET_TIMEOUT  5
#define USB_CTRL_SET_TIMEOUT  5


/**
 * struct usb_sg_request - support for scatter/gather I/O
 * @status: zero indicates success, else negative errno
 * @bytes: counts bytes transferred.
 *
 * These requests are initialized using usb_sg_init(), and then are used
 * as request handles passed to usb_sg_wait() or usb_sg_cancel().  Most
 * members of the request object aren't for driver access.
 *
 * The status and bytecount values are valid only after usb_sg_wait()
 * returns.  If the status is zero, then the bytecount matches the total
 * from the request.
 *
 * After an error completion, drivers may need to clear a halt condition
 * on the endpoint.
 */
struct usb_sg_request {
      int               status;
      size_t                  bytes;

      // members not documented above are private to usbcore,
      // and are not provided for driver access!
      spinlock_t        lock;

      struct usb_device *dev;
      int               pipe;
      struct scatterlist      *sg;
      int               nents;

      int               entries;
      struct urb        **urbs;

      int               count;
      struct completion complete;
};

int usb_sg_init (
      struct usb_sg_request   *io,
      struct usb_device *dev,
      unsigned          pipe, 
      unsigned          period,
      struct scatterlist      *sg,
      int               nents,
      size_t                  length,
      int               mem_flags
);
void usb_sg_cancel (struct usb_sg_request *io);
void usb_sg_wait (struct usb_sg_request *io);


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

/*
 * Calling this entity a "pipe" is glorifying it. A USB pipe
 * is something embarrassingly simple: it basically consists
 * of the following information:
 *  - device number (7 bits)
 *  - endpoint number (4 bits)
 *  - current Data0/1 state (1 bit) [Historical; now gone]
 *  - direction (1 bit)
 *  - speed (1 bit) [Historical and specific to USB 1.1; now gone.]
 *  - max packet size (2 bits: 8, 16, 32 or 64) [Historical; now gone.]
 *  - pipe type (2 bits: control, interrupt, bulk, isochronous)
 *
 * That's 18 bits. Really. Nothing more. And the USB people have
 * documented these eighteen bits as some kind of glorious
 * virtual data structure.
 *
 * Let's not fall in that trap. We'll just encode it as a simple
 * unsigned int. The encoding is:
 *
 *  - max size:         bits 0-1    [Historical; now gone.]
 *  - direction:  bit 7       (0 = Host-to-Device [Out],
 *                             1 = Device-to-Host [In] ...
 *                            like endpoint bEndpointAddress)
 *  - device:           bits 8-14       ... bit positions known to uhci-hcd
 *  - endpoint:         bits 15-18      ... bit positions known to uhci-hcd
 *  - Data0/1:          bit 19            [Historical; now gone. ]
 *  - lowspeed:         bit 26            [Historical; now gone. ]
 *  - pipe type:  bits 30-31  (00 = isochronous, 01 = interrupt,
 *                             10 = control, 11 = bulk)
 *
 * Why? Because it's arbitrary, and whatever encoding we select is really
 * up to us. This one happens to share a lot of bit positions with the UHCI
 * specification, so that much of the uhci driver can just mask the bits
 * appropriately.
 */

/* NOTE:  these are not the standard USB_ENDPOINT_XFER_* values!! */
#define PIPE_ISOCHRONOUS            0
#define PIPE_INTERRUPT              1
#define PIPE_CONTROL                2
#define PIPE_BULK             3

#define usb_maxpacket(dev, pipe, out)     (out \
                        ? (dev)->epmaxpacketout[usb_pipeendpoint(pipe)] \
                        : (dev)->epmaxpacketin [usb_pipeendpoint(pipe)] )

#define usb_pipein(pipe)      ((pipe) & USB_DIR_IN)
#define usb_pipeout(pipe)     (!usb_pipein(pipe))
#define usb_pipedevice(pipe)  (((pipe) >> 8) & 0x7f)
#define usb_pipeendpoint(pipe)      (((pipe) >> 15) & 0xf)
#define usb_pipetype(pipe)    (((pipe) >> 30) & 3)
#define usb_pipeisoc(pipe)    (usb_pipetype((pipe)) == PIPE_ISOCHRONOUS)
#define usb_pipeint(pipe)     (usb_pipetype((pipe)) == PIPE_INTERRUPT)
#define usb_pipecontrol(pipe) (usb_pipetype((pipe)) == PIPE_CONTROL)
#define usb_pipebulk(pipe)    (usb_pipetype((pipe)) == PIPE_BULK)

/* The D0/D1 toggle bits ... USE WITH CAUTION (they're almost hcd-internal) */
#define usb_gettoggle(dev, ep, out) (((dev)->toggle[out] >> (ep)) & 1)
#define     usb_dotoggle(dev, ep, out)  ((dev)->toggle[out] ^= (1 << (ep)))
#define usb_settoggle(dev, ep, out, bit) ((dev)->toggle[out] = ((dev)->toggle[out] & ~(1 << (ep))) | ((bit) << (ep)))

/* Endpoint halt control/status ... likewise USE WITH CAUTION */
#define usb_endpoint_running(dev, ep, out) ((dev)->halted[out] &= ~(1 << (ep)))
#define usb_endpoint_halted(dev, ep, out) ((dev)->halted[out] & (1 << (ep)))


static inline unsigned int __create_pipe(struct usb_device *dev, unsigned int endpoint)
{
      return (dev->devnum << 8) | (endpoint << 15);
}

/* Create various pipes... */
#define usb_sndctrlpipe(dev,endpoint)     ((PIPE_CONTROL << 30) | __create_pipe(dev,endpoint))
#define usb_rcvctrlpipe(dev,endpoint)     ((PIPE_CONTROL << 30) | __create_pipe(dev,endpoint) | USB_DIR_IN)
#define usb_sndisocpipe(dev,endpoint)     ((PIPE_ISOCHRONOUS << 30) | __create_pipe(dev,endpoint))
#define usb_rcvisocpipe(dev,endpoint)     ((PIPE_ISOCHRONOUS << 30) | __create_pipe(dev,endpoint) | USB_DIR_IN)
#define usb_sndbulkpipe(dev,endpoint)     ((PIPE_BULK << 30) | __create_pipe(dev,endpoint))
#define usb_rcvbulkpipe(dev,endpoint)     ((PIPE_BULK << 30) | __create_pipe(dev,endpoint) | USB_DIR_IN)
#define usb_sndintpipe(dev,endpoint)      ((PIPE_INTERRUPT << 30) | __create_pipe(dev,endpoint))
#define usb_rcvintpipe(dev,endpoint)      ((PIPE_INTERRUPT << 30) | __create_pipe(dev,endpoint) | USB_DIR_IN)

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

/*
 * Debugging and troubleshooting/diagnostic helpers.
 */
void usb_show_device_descriptor(struct usb_device_descriptor *);
void usb_show_config_descriptor(struct usb_config_descriptor *);
void usb_show_interface_descriptor(struct usb_interface_descriptor *);
void usb_show_endpoint_descriptor(struct usb_endpoint_descriptor *);
void usb_show_device(struct usb_device *);
void usb_show_string(struct usb_device *dev, char *id, int index);

#ifdef DEBUG
#define dbg(format, arg...) printk(KERN_DEBUG "%s: " format "\n" , __FILE__ , ## arg)
#else
#define dbg(format, arg...) do {} while (0)
#endif



#ifdef DEBUG_MODE
#define info(format, arg...) printk(KERN_INFO __FILE__ ": " format "\n" , ## arg)
#define err(format, arg...) printk(KERN_ERR __FILE__ ": " format "\n" , ## arg)
#define warn(format, arg...) printk(KERN_WARNING __FILE__ ": " format "\n" , ## arg)
#endif

#ifndef DEBUG_MODE                                                               
#define info(format, arg...) do {} while (0)
#define err(format, arg...) do {} while (0)
#define warn(format, arg...) do {} while (0)
#endif

#endif  /* __KERNEL__ */

#endif

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