Subversion Repositories shark

#ifndef __LINUX_USB_H

#define __LINUX_USB_H

#include <linux/mod_devicetable.h>

#include <linux/usb_ch9.h>

#define USB_MAJOR                       180

#ifdef __KERNEL__

#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 */

extern int wait_ms26(unsigned long timeout);

static __inline__ void wait_ms(unsigned int ms)

{

        wait_ms26(ms);

//      if(!in_interrupt()) {

//              current->state = TASK_UNINTERRUPTIBLE;

//                schedule_timeout(1 + ms * HZ / 1000);

//      }

//      else

//              mdelay(ms);

}

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.

 * @driver: the USB driver that is bound to this interface.

 * @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 */

        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 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);

}

/* this maximum is arbitrary */

#define USB_MAXINTERFACES       32

/* 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[USB_MAXINTERFACES];

        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 */

        struct class_device class_dev;  /* class device for this bus */

        void (*release)(struct usb_bus *bus);   /* function to destroy this bus's memory */

};

#define to_usb_bus(d) container_of(d, struct usb_bus, class_dev)

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

/* 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 int 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 = snprintf26(buf, size, "usb-%s-%s", dev->bus->bus_name, dev->devpath);

        return (actual >= (int)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.

 * @suspend: Called when the device is going to be suspended by the system.

 * @resume: Called when the device is being resumed by the system.

 * @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.

 * @driver: the driver model core driver structure.

 * @serialize: a semaphore used to serialize access to this driver.  Used

 *      in the probe and disconnect functions.  Only the USB core should use

 *      this lock.

 *

 * 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);

        int (*suspend) (struct usb_interface *intf, u32 state);

        int (*resume) (struct usb_interface *intf);

        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_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_TRANSFER_DMA_MAP 0x0004  /* urb->transfer_dma valid on submit */

#define URB_NO_SETUP_DMA_MAP    0x0008  /* urb->setup_dma valid on submit */

#define URB_ASYNC_UNLINK        0x0010  /* 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_TRANSFER_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_TRANSFER_DMA_MAP,

 *      the device driver is saying that it provided this DMA address,

 *      which the host controller driver should use in preference to 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.

 * @setup_dma: For control transfers with URB_NO_SETUP_DMA_MAP set, the

 *      device driver has provided this DMA address for the setup packet.

 *      The host controller driver should use this in preference to

 *      setup_packet.

 * @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.

 * @timeout: If set to zero, the urb will never timeout.  Otherwise this is

 *      the time in jiffies that this urb will timeout in.

 *

 * 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_xxx_DMA_MAP transfer flags,

 * which tell the host controller driver that no such mapping is needed since

 * the device driver is DMA-aware.  For example, a device driver might

 * allocate a DMA buffer with usb_buffer_alloc() or call usb_buffer_map().

 * When these transfer flags are provided, host controller drivers will

 * attempt to use the dma addresses found in the transfer_dma and/or

 * setup_dma fields rather than determining a dma address themselves.  (Note

 * that transfer_buffer and setup_packet must still be set because not all

 * host controllers use DMA, nor do virtual root hubs).

 *

 * 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.  The setup_packet and

 * transfer_buffer may each be mapped for DMA or not, independently of

 * the other.  The transfer_flags bits URB_NO_TRANSFER_DMA_MAP and

 * URB_NO_SETUP_DMA_MAP indicate which buffers have already been mapped.

 * URB_NO_SETUP_DMA_MAP is ignored for non-control URBs.

 *

 * 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

{

        /* private, usb core and host controller only fields in the 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 */

        int bandwidth;                  /* bandwidth for INT/ISO request */

        /* public, documented fields in the urb that can be used by drivers */

        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 */

        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_reset_configuration(struct usb_device *dev);

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