usb.c

ReactOs中的USB驱动

/*
 * drivers/usb/usb.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 (new USB architecture)
 * (C) Copyright Randy Dunlap 2000
 * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
 	more docs, etc)
 * (C) Copyright Yggdrasil Computing, Inc. 2000
 *     (usb_device_id matching changes by Adam J. Richter)
 * (C) Copyright Greg Kroah-Hartman 2002-2003
 *
 * NOTE! This is not actually a driver at all, rather this is
 * just a collection of helper routines that implement the
 * generic USB things that the real drivers can use..
 *
 * Think of this as a "USB library" rather than anything else.
 * It should be considered a slave, with no callbacks. Callbacks
 * are evil.
 */

#if 0
#include <linux/config.h>

#ifdef CONFIG_USB_DEBUG
	#define DEBUG
#else
	#undef DEBUG
#endif

#include <linux/module.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/interrupt.h>  /* for in_interrupt() */
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/usb.h>

#include <asm/io.h>
#include <asm/scatterlist.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include "hcd.h"
#include "usb.h"
#else
#include "../miniport/usb_wrapper.h"
#include "hcd.h"
#endif

extern int  usb_hub_init(void);
extern void usb_hub_cleanup(void);
extern int usb_major_init(void);
extern void usb_major_cleanup(void);


int nousb;		/* Disable USB when built into kernel image */
			/* Not honored on modular build */


static int generic_probe (struct device *dev)
{
	return 0;
}
static int generic_remove (struct device *dev)
{
	return 0;
}

static struct device_driver usb_generic_driver = {
	.name =	"usb",
	.bus = &usb_bus_type,
	.probe = generic_probe,
	.remove = generic_remove,
};

static int usb_generic_driver_data;

/* needs to be called with BKL held */
int usb_device_probe(struct device *dev)
{
	struct usb_interface * intf = to_usb_interface(dev);
	struct usb_driver * driver = to_usb_driver(dev->driver);
	const struct usb_device_id *id;
	int error = -ENODEV;

	dev_dbg(dev, "%s\n", __FUNCTION__);

	if (!driver->probe)
		return error;
	/* driver claim() doesn't yet affect dev->driver... */
	if (intf->driver)
		return error;

	id = usb_match_id (intf, driver->id_table);
	if (id) {
		dev_dbg (dev, "%s - got id\n", __FUNCTION__);
		down (&driver->serialize);
		error = driver->probe (intf, id);
		up (&driver->serialize);
	}
	if (!error)
		intf->driver = driver;

	return error;
}

int usb_device_remove(struct device *dev)
{
	struct usb_interface *intf;
	struct usb_driver *driver;

	intf = list_entry(dev,struct usb_interface,dev);
	driver = to_usb_driver(dev->driver);

	down(&driver->serialize);

	if (intf->driver && intf->driver->disconnect)
		intf->driver->disconnect(intf);

	/* if driver->disconnect didn't release the interface */
	if (intf->driver)
		usb_driver_release_interface(driver, intf);

	up(&driver->serialize);

	return 0;
}

/**
 * usb_register - register a USB driver
 * @new_driver: USB operations for the driver
 *
 * Registers a USB driver with the USB core.  The list of unattached
 * interfaces will be rescanned whenever a new driver is added, allowing
 * the new driver to attach to any recognized devices.
 * Returns a negative error code on failure and 0 on success.
 * 
 * NOTE: if you want your driver to use the USB major number, you must call
 * usb_register_dev() to enable that functionality.  This function no longer
 * takes care of that.
 */
int usb_register(struct usb_driver *new_driver)
{
	int retval = 0;

	if (nousb)
		return -ENODEV;

	new_driver->driver.name = (char *)new_driver->name;
	new_driver->driver.bus = &usb_bus_type;
	new_driver->driver.probe = usb_device_probe;
	new_driver->driver.remove = usb_device_remove;

	init_MUTEX(&new_driver->serialize);

	retval = driver_register(&new_driver->driver);

	if (!retval) {
		info("registered new driver %s", new_driver->name);
		usbfs_update_special();
	} else {
		err("problem %d when registering driver %s",
			retval, new_driver->name);
	}

	return retval;
}

/**
 * usb_deregister - unregister a USB driver
 * @driver: USB operations of the driver to unregister
 * Context: !in_interrupt (), must be called with BKL held
 *
 * Unlinks the specified driver from the internal USB driver list.
 * 
 * NOTE: If you called usb_register_dev(), you still need to call
 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
 * this * call will no longer do it for you.
 */
void usb_deregister(struct usb_driver *driver)
{
	info("deregistering driver %s", driver->name);

	driver_unregister (&driver->driver);

	usbfs_update_special();
}

/**
 * usb_ifnum_to_if - get the interface object with a given interface number (usbcore-internal)
 * @dev: the device whose current configuration is considered
 * @ifnum: the desired interface
 *
 * This walks the device descriptor for the currently active configuration
 * and returns a pointer to the interface with that particular interface
 * number, or null.
 *
 * Note that configuration descriptors are not required to assign interface
 * numbers sequentially, so that it would be incorrect to assume that
 * the first interface in that descriptor corresponds to interface zero.
 * This routine helps device drivers avoid such mistakes.
 * However, you should make sure that you do the right thing with any
 * alternate settings available for this interfaces.
 */
struct usb_interface *usb_ifnum_to_if(struct usb_device *dev, unsigned ifnum)
{
	int i;

	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
		if (dev->actconfig->interface[i].altsetting[0]
				.desc.bInterfaceNumber == ifnum)
			return &dev->actconfig->interface[i];

	return NULL;
}

/**
 * usb_epnum_to_ep_desc - get the endpoint object with a given endpoint number
 * @dev: the device whose current configuration is considered
 * @epnum: the desired endpoint
 *
 * This walks the device descriptor for the currently active configuration,
 * and returns a pointer to the endpoint with that particular endpoint
 * number, or null.
 *
 * Note that interface descriptors are not required to assign endpont
 * numbers sequentially, so that it would be incorrect to assume that
 * the first endpoint in that descriptor corresponds to interface zero.
 * This routine helps device drivers avoid such mistakes.
 */
struct usb_endpoint_descriptor *
usb_epnum_to_ep_desc(struct usb_device *dev, unsigned epnum)
{
	int i, j, k;

	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
		for (j = 0; j < dev->actconfig->interface[i].num_altsetting; j++)
			for (k = 0; k < dev->actconfig->interface[i]
				.altsetting[j].desc.bNumEndpoints; k++)
				if (epnum == dev->actconfig->interface[i]
						.altsetting[j].endpoint[k]
						.desc.bEndpointAddress)
					return &dev->actconfig->interface[i]
						.altsetting[j].endpoint[k]
						.desc;

	return NULL;
}

/**
 * usb_driver_claim_interface - bind a driver to an interface
 * @driver: the driver to be bound
 * @iface: the interface to which it will be bound
 * @priv: driver data associated with that interface
 *
 * This is used by usb device drivers that need to claim more than one
 * interface on a device when probing (audio and acm are current examples).
 * No device driver should directly modify internal usb_interface or
 * usb_device structure members.
 *
 * Few drivers should need to use this routine, since the most natural
 * way to bind to an interface is to return the private data from
 * the driver's probe() method.  Any driver that does use this must
 * first be sure that no other driver has claimed the interface, by
 * checking with usb_interface_claimed().
 */
void usb_driver_claim_interface(struct usb_driver *driver, struct usb_interface *iface, void* priv)
{
	if (!iface || !driver)
		return;

	// FIXME change API to report an error in this case
        if (iface->driver) {
	    err ("%s driver booted %s off interface %p",
	    	driver->name, iface->driver->name, iface);
        }
        else {
	    dbg("%s driver claimed interface %p", driver->name, iface);
        }
	iface->driver = driver;
	usb_set_intfdata(iface, priv);
}

/**
 * usb_interface_claimed - returns true iff an interface is claimed
 * @iface: the interface being checked
 *
 * This should be used by drivers to check other interfaces to see if
 * they are available or not.  If another driver has claimed the interface,
 * they may not claim it.  Otherwise it's OK to claim it using
 * usb_driver_claim_interface().
 *
 * Returns true (nonzero) iff the interface is claimed, else false (zero).
 */
int usb_interface_claimed(struct usb_interface *iface)
{
	if (!iface)
		return 0;

	return (iface->driver != NULL);
} /* usb_interface_claimed() */

/**
 * usb_driver_release_interface - unbind a driver from an interface
 * @driver: the driver to be unbound
 * @iface: the interface from which it will be unbound
 * 
 * This should be used by drivers to release their claimed interfaces.
 * It is normally called in their disconnect() methods, and only for
 * drivers that bound to more than one interface in their probe().
 *
 * When the USB subsystem disconnect()s a driver from some interface,
 * it automatically invokes this method for that interface.  That
 * means that even drivers that used usb_driver_claim_interface()
 * usually won't need to call this.
 */
void usb_driver_release_interface(struct usb_driver *driver, struct usb_interface *iface)
{
	/* this should never happen, don't release something that's not ours */
	if (!iface || iface->driver != driver)
		return;

	iface->driver = NULL;
	usb_set_intfdata(iface, NULL);
}

/**
 * usb_match_id - find first usb_device_id matching device or interface
 * @interface: the interface of interest
 * @id: array of usb_device_id structures, terminated by zero entry
 *
 * usb_match_id searches an array of usb_device_id's and returns
 * the first one matching the device or interface, or null.
 * This is used when binding (or rebinding) a driver to an interface.
 * Most USB device drivers will use this indirectly, through the usb core,
 * but some layered driver frameworks use it directly.
 * These device tables are exported with MODULE_DEVICE_TABLE, through
 * modutils and "modules.usbmap", to support the driver loading
 * functionality of USB hotplugging.
 *
 * What Matches:
 *
 * The "match_flags" element in a usb_device_id controls which
 * members are used.  If the corresponding bit is set, the
 * value in the device_id must match its corresponding member
 * in the device or interface descriptor, or else the device_id
 * does not match.
 *
 * "driver_info" is normally used only by device drivers,
 * but you can create a wildcard "matches anything" usb_device_id
 * as a driver's "modules.usbmap" entry if you provide an id with
 * only a nonzero "driver_info" field.  If you do this, the USB device
 * driver's probe() routine should use additional intelligence to
 * decide whether to bind to the specified interface.
 * 
 * What Makes Good usb_device_id Tables:
 *
 * The match algorithm is very simple, so that intelligence in
 * driver selection must come from smart driver id records.
 * Unless you have good reasons to use another selection policy,
 * provide match elements only in related groups, and order match
 * specifiers from specific to general.  Use the macros provided
 * for that purpose if you can.
 *
 * The most specific match specifiers use device descriptor
 * data.  These are commonly used with product-specific matches;
 * the USB_DEVICE macro lets you provide vendor and product IDs,
 * and you can also match against ranges of product revisions.
 * These are widely used for devices with application or vendor
 * specific bDeviceClass values.
 *
 * Matches based on device class/subclass/protocol specifications
 * are slightly more general; use the USB_DEVICE_INFO macro, or
 * its siblings.  These are used with single-function devices
 * where bDeviceClass doesn't specify that each interface has
 * its own class. 
 *
 * Matches based on interface class/subclass/protocol are the
 * most general; they let drivers bind to any interface on a
 * multiple-function device.  Use the USB_INTERFACE_INFO
 * macro, or its siblings, to match class-per-interface style 
 * devices (as recorded in bDeviceClass).
 *  
 * Within those groups, remember that not all combinations are
 * meaningful.  For example, don't give a product version range
 * without vendor and product IDs; or specify a protocol without
 * its associated class and subclass.
 */   
const struct usb_device_id *
usb_match_id(struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_host_interface *intf;
	struct usb_device *dev;
	struct usb_device_id *save_id;
	int firsttime;
	
	firsttime = 1;
	
	save_id = (struct usb_device_id*)id;
	id = (struct usb_device_id*)save_id;