xref: /linux/include/linux/usb.h (revision e9fb13bfec7e017130ddc5c1b5466340470f4900)
1 #ifndef __LINUX_USB_H
2 #define __LINUX_USB_H
3 
4 #include <linux/mod_devicetable.h>
5 #include <linux/usb/ch9.h>
6 
7 #define USB_MAJOR			180
8 #define USB_DEVICE_MAJOR		189
9 
10 
11 #ifdef __KERNEL__
12 
13 #include <linux/errno.h>        /* for -ENODEV */
14 #include <linux/delay.h>	/* for mdelay() */
15 #include <linux/interrupt.h>	/* for in_interrupt() */
16 #include <linux/list.h>		/* for struct list_head */
17 #include <linux/kref.h>		/* for struct kref */
18 #include <linux/device.h>	/* for struct device */
19 #include <linux/fs.h>		/* for struct file_operations */
20 #include <linux/completion.h>	/* for struct completion */
21 #include <linux/sched.h>	/* for current && schedule_timeout */
22 #include <linux/mutex.h>	/* for struct mutex */
23 #include <linux/pm_runtime.h>	/* for runtime PM */
24 
25 struct usb_device;
26 struct usb_driver;
27 struct wusb_dev;
28 
29 /*-------------------------------------------------------------------------*/
30 
31 /*
32  * Host-side wrappers for standard USB descriptors ... these are parsed
33  * from the data provided by devices.  Parsing turns them from a flat
34  * sequence of descriptors into a hierarchy:
35  *
36  *  - devices have one (usually) or more configs;
37  *  - configs have one (often) or more interfaces;
38  *  - interfaces have one (usually) or more settings;
39  *  - each interface setting has zero or (usually) more endpoints.
40  *  - a SuperSpeed endpoint has a companion descriptor
41  *
42  * And there might be other descriptors mixed in with those.
43  *
44  * Devices may also have class-specific or vendor-specific descriptors.
45  */
46 
47 struct ep_device;
48 
49 /**
50  * struct usb_host_endpoint - host-side endpoint descriptor and queue
51  * @desc: descriptor for this endpoint, wMaxPacketSize in native byteorder
52  * @ss_ep_comp: SuperSpeed companion descriptor for this endpoint
53  * @urb_list: urbs queued to this endpoint; maintained by usbcore
54  * @hcpriv: for use by HCD; typically holds hardware dma queue head (QH)
55  *	with one or more transfer descriptors (TDs) per urb
56  * @ep_dev: ep_device for sysfs info
57  * @extra: descriptors following this endpoint in the configuration
58  * @extralen: how many bytes of "extra" are valid
59  * @enabled: URBs may be submitted to this endpoint
60  *
61  * USB requests are always queued to a given endpoint, identified by a
62  * descriptor within an active interface in a given USB configuration.
63  */
64 struct usb_host_endpoint {
65 	struct usb_endpoint_descriptor		desc;
66 	struct usb_ss_ep_comp_descriptor	ss_ep_comp;
67 	struct list_head		urb_list;
68 	void				*hcpriv;
69 	struct ep_device		*ep_dev;	/* For sysfs info */
70 
71 	unsigned char *extra;   /* Extra descriptors */
72 	int extralen;
73 	int enabled;
74 };
75 
76 /* host-side wrapper for one interface setting's parsed descriptors */
77 struct usb_host_interface {
78 	struct usb_interface_descriptor	desc;
79 
80 	/* array of desc.bNumEndpoint endpoints associated with this
81 	 * interface setting.  these will be in no particular order.
82 	 */
83 	struct usb_host_endpoint *endpoint;
84 
85 	char *string;		/* iInterface string, if present */
86 	unsigned char *extra;   /* Extra descriptors */
87 	int extralen;
88 };
89 
90 enum usb_interface_condition {
91 	USB_INTERFACE_UNBOUND = 0,
92 	USB_INTERFACE_BINDING,
93 	USB_INTERFACE_BOUND,
94 	USB_INTERFACE_UNBINDING,
95 };
96 
97 /**
98  * struct usb_interface - what usb device drivers talk to
99  * @altsetting: array of interface structures, one for each alternate
100  *	setting that may be selected.  Each one includes a set of
101  *	endpoint configurations.  They will be in no particular order.
102  * @cur_altsetting: the current altsetting.
103  * @num_altsetting: number of altsettings defined.
104  * @intf_assoc: interface association descriptor
105  * @minor: the minor number assigned to this interface, if this
106  *	interface is bound to a driver that uses the USB major number.
107  *	If this interface does not use the USB major, this field should
108  *	be unused.  The driver should set this value in the probe()
109  *	function of the driver, after it has been assigned a minor
110  *	number from the USB core by calling usb_register_dev().
111  * @condition: binding state of the interface: not bound, binding
112  *	(in probe()), bound to a driver, or unbinding (in disconnect())
113  * @sysfs_files_created: sysfs attributes exist
114  * @ep_devs_created: endpoint child pseudo-devices exist
115  * @unregistering: flag set when the interface is being unregistered
116  * @needs_remote_wakeup: flag set when the driver requires remote-wakeup
117  *	capability during autosuspend.
118  * @needs_altsetting0: flag set when a set-interface request for altsetting 0
119  *	has been deferred.
120  * @needs_binding: flag set when the driver should be re-probed or unbound
121  *	following a reset or suspend operation it doesn't support.
122  * @dev: driver model's view of this device
123  * @usb_dev: if an interface is bound to the USB major, this will point
124  *	to the sysfs representation for that device.
125  * @pm_usage_cnt: PM usage counter for this interface
126  * @reset_ws: Used for scheduling resets from atomic context.
127  * @reset_running: set to 1 if the interface is currently running a
128  *      queued reset so that usb_cancel_queued_reset() doesn't try to
129  *      remove from the workqueue when running inside the worker
130  *      thread. See __usb_queue_reset_device().
131  * @resetting_device: USB core reset the device, so use alt setting 0 as
132  *	current; needs bandwidth alloc after reset.
133  *
134  * USB device drivers attach to interfaces on a physical device.  Each
135  * interface encapsulates a single high level function, such as feeding
136  * an audio stream to a speaker or reporting a change in a volume control.
137  * Many USB devices only have one interface.  The protocol used to talk to
138  * an interface's endpoints can be defined in a usb "class" specification,
139  * or by a product's vendor.  The (default) control endpoint is part of
140  * every interface, but is never listed among the interface's descriptors.
141  *
142  * The driver that is bound to the interface can use standard driver model
143  * calls such as dev_get_drvdata() on the dev member of this structure.
144  *
145  * Each interface may have alternate settings.  The initial configuration
146  * of a device sets altsetting 0, but the device driver can change
147  * that setting using usb_set_interface().  Alternate settings are often
148  * used to control the use of periodic endpoints, such as by having
149  * different endpoints use different amounts of reserved USB bandwidth.
150  * All standards-conformant USB devices that use isochronous endpoints
151  * will use them in non-default settings.
152  *
153  * The USB specification says that alternate setting numbers must run from
154  * 0 to one less than the total number of alternate settings.  But some
155  * devices manage to mess this up, and the structures aren't necessarily
156  * stored in numerical order anyhow.  Use usb_altnum_to_altsetting() to
157  * look up an alternate setting in the altsetting array based on its number.
158  */
159 struct usb_interface {
160 	/* array of alternate settings for this interface,
161 	 * stored in no particular order */
162 	struct usb_host_interface *altsetting;
163 
164 	struct usb_host_interface *cur_altsetting;	/* the currently
165 					 * active alternate setting */
166 	unsigned num_altsetting;	/* number of alternate settings */
167 
168 	/* If there is an interface association descriptor then it will list
169 	 * the associated interfaces */
170 	struct usb_interface_assoc_descriptor *intf_assoc;
171 
172 	int minor;			/* minor number this interface is
173 					 * bound to */
174 	enum usb_interface_condition condition;		/* state of binding */
175 	unsigned sysfs_files_created:1;	/* the sysfs attributes exist */
176 	unsigned ep_devs_created:1;	/* endpoint "devices" exist */
177 	unsigned unregistering:1;	/* unregistration is in progress */
178 	unsigned needs_remote_wakeup:1;	/* driver requires remote wakeup */
179 	unsigned needs_altsetting0:1;	/* switch to altsetting 0 is pending */
180 	unsigned needs_binding:1;	/* needs delayed unbind/rebind */
181 	unsigned reset_running:1;
182 	unsigned resetting_device:1;	/* true: bandwidth alloc after reset */
183 
184 	struct device dev;		/* interface specific device info */
185 	struct device *usb_dev;
186 	atomic_t pm_usage_cnt;		/* usage counter for autosuspend */
187 	struct work_struct reset_ws;	/* for resets in atomic context */
188 };
189 #define	to_usb_interface(d) container_of(d, struct usb_interface, dev)
190 
191 static inline void *usb_get_intfdata(struct usb_interface *intf)
192 {
193 	return dev_get_drvdata(&intf->dev);
194 }
195 
196 static inline void usb_set_intfdata(struct usb_interface *intf, void *data)
197 {
198 	dev_set_drvdata(&intf->dev, data);
199 }
200 
201 struct usb_interface *usb_get_intf(struct usb_interface *intf);
202 void usb_put_intf(struct usb_interface *intf);
203 
204 /* this maximum is arbitrary */
205 #define USB_MAXINTERFACES	32
206 #define USB_MAXIADS		(USB_MAXINTERFACES/2)
207 
208 /**
209  * struct usb_interface_cache - long-term representation of a device interface
210  * @num_altsetting: number of altsettings defined.
211  * @ref: reference counter.
212  * @altsetting: variable-length array of interface structures, one for
213  *	each alternate setting that may be selected.  Each one includes a
214  *	set of endpoint configurations.  They will be in no particular order.
215  *
216  * These structures persist for the lifetime of a usb_device, unlike
217  * struct usb_interface (which persists only as long as its configuration
218  * is installed).  The altsetting arrays can be accessed through these
219  * structures at any time, permitting comparison of configurations and
220  * providing support for the /proc/bus/usb/devices pseudo-file.
221  */
222 struct usb_interface_cache {
223 	unsigned num_altsetting;	/* number of alternate settings */
224 	struct kref ref;		/* reference counter */
225 
226 	/* variable-length array of alternate settings for this interface,
227 	 * stored in no particular order */
228 	struct usb_host_interface altsetting[0];
229 };
230 #define	ref_to_usb_interface_cache(r) \
231 		container_of(r, struct usb_interface_cache, ref)
232 #define	altsetting_to_usb_interface_cache(a) \
233 		container_of(a, struct usb_interface_cache, altsetting[0])
234 
235 /**
236  * struct usb_host_config - representation of a device's configuration
237  * @desc: the device's configuration descriptor.
238  * @string: pointer to the cached version of the iConfiguration string, if
239  *	present for this configuration.
240  * @intf_assoc: list of any interface association descriptors in this config
241  * @interface: array of pointers to usb_interface structures, one for each
242  *	interface in the configuration.  The number of interfaces is stored
243  *	in desc.bNumInterfaces.  These pointers are valid only while the
244  *	the configuration is active.
245  * @intf_cache: array of pointers to usb_interface_cache structures, one
246  *	for each interface in the configuration.  These structures exist
247  *	for the entire life of the device.
248  * @extra: pointer to buffer containing all extra descriptors associated
249  *	with this configuration (those preceding the first interface
250  *	descriptor).
251  * @extralen: length of the extra descriptors buffer.
252  *
253  * USB devices may have multiple configurations, but only one can be active
254  * at any time.  Each encapsulates a different operational environment;
255  * for example, a dual-speed device would have separate configurations for
256  * full-speed and high-speed operation.  The number of configurations
257  * available is stored in the device descriptor as bNumConfigurations.
258  *
259  * A configuration can contain multiple interfaces.  Each corresponds to
260  * a different function of the USB device, and all are available whenever
261  * the configuration is active.  The USB standard says that interfaces
262  * are supposed to be numbered from 0 to desc.bNumInterfaces-1, but a lot
263  * of devices get this wrong.  In addition, the interface array is not
264  * guaranteed to be sorted in numerical order.  Use usb_ifnum_to_if() to
265  * look up an interface entry based on its number.
266  *
267  * Device drivers should not attempt to activate configurations.  The choice
268  * of which configuration to install is a policy decision based on such
269  * considerations as available power, functionality provided, and the user's
270  * desires (expressed through userspace tools).  However, drivers can call
271  * usb_reset_configuration() to reinitialize the current configuration and
272  * all its interfaces.
273  */
274 struct usb_host_config {
275 	struct usb_config_descriptor	desc;
276 
277 	char *string;		/* iConfiguration string, if present */
278 
279 	/* List of any Interface Association Descriptors in this
280 	 * configuration. */
281 	struct usb_interface_assoc_descriptor *intf_assoc[USB_MAXIADS];
282 
283 	/* the interfaces associated with this configuration,
284 	 * stored in no particular order */
285 	struct usb_interface *interface[USB_MAXINTERFACES];
286 
287 	/* Interface information available even when this is not the
288 	 * active configuration */
289 	struct usb_interface_cache *intf_cache[USB_MAXINTERFACES];
290 
291 	unsigned char *extra;   /* Extra descriptors */
292 	int extralen;
293 };
294 
295 int __usb_get_extra_descriptor(char *buffer, unsigned size,
296 	unsigned char type, void **ptr);
297 #define usb_get_extra_descriptor(ifpoint, type, ptr) \
298 				__usb_get_extra_descriptor((ifpoint)->extra, \
299 				(ifpoint)->extralen, \
300 				type, (void **)ptr)
301 
302 /* ----------------------------------------------------------------------- */
303 
304 /* USB device number allocation bitmap */
305 struct usb_devmap {
306 	unsigned long devicemap[128 / (8*sizeof(unsigned long))];
307 };
308 
309 /*
310  * Allocated per bus (tree of devices) we have:
311  */
312 struct usb_bus {
313 	struct device *controller;	/* host/master side hardware */
314 	int busnum;			/* Bus number (in order of reg) */
315 	const char *bus_name;		/* stable id (PCI slot_name etc) */
316 	u8 uses_dma;			/* Does the host controller use DMA? */
317 	u8 uses_pio_for_control;	/*
318 					 * Does the host controller use PIO
319 					 * for control transfers?
320 					 */
321 	u8 otg_port;			/* 0, or number of OTG/HNP port */
322 	unsigned is_b_host:1;		/* true during some HNP roleswitches */
323 	unsigned b_hnp_enable:1;	/* OTG: did A-Host enable HNP? */
324 	unsigned sg_tablesize;		/* 0 or largest number of sg list entries */
325 
326 	int devnum_next;		/* Next open device number in
327 					 * round-robin allocation */
328 
329 	struct usb_devmap devmap;	/* device address allocation map */
330 	struct usb_device *root_hub;	/* Root hub */
331 	struct usb_bus *hs_companion;	/* Companion EHCI bus, if any */
332 	struct list_head bus_list;	/* list of busses */
333 
334 	int bandwidth_allocated;	/* on this bus: how much of the time
335 					 * reserved for periodic (intr/iso)
336 					 * requests is used, on average?
337 					 * Units: microseconds/frame.
338 					 * Limits: Full/low speed reserve 90%,
339 					 * while high speed reserves 80%.
340 					 */
341 	int bandwidth_int_reqs;		/* number of Interrupt requests */
342 	int bandwidth_isoc_reqs;	/* number of Isoc. requests */
343 
344 #ifdef CONFIG_USB_DEVICEFS
345 	struct dentry *usbfs_dentry;	/* usbfs dentry entry for the bus */
346 #endif
347 
348 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
349 	struct mon_bus *mon_bus;	/* non-null when associated */
350 	int monitored;			/* non-zero when monitored */
351 #endif
352 };
353 
354 /* ----------------------------------------------------------------------- */
355 
356 /* This is arbitrary.
357  * From USB 2.0 spec Table 11-13, offset 7, a hub can
358  * have up to 255 ports. The most yet reported is 10.
359  *
360  * Current Wireless USB host hardware (Intel i1480 for example) allows
361  * up to 22 devices to connect. Upcoming hardware might raise that
362  * limit. Because the arrays need to add a bit for hub status data, we
363  * do 31, so plus one evens out to four bytes.
364  */
365 #define USB_MAXCHILDREN		(31)
366 
367 struct usb_tt;
368 
369 /**
370  * struct usb_device - kernel's representation of a USB device
371  * @devnum: device number; address on a USB bus
372  * @devpath: device ID string for use in messages (e.g., /port/...)
373  * @route: tree topology hex string for use with xHCI
374  * @state: device state: configured, not attached, etc.
375  * @speed: device speed: high/full/low (or error)
376  * @tt: Transaction Translator info; used with low/full speed dev, highspeed hub
377  * @ttport: device port on that tt hub
378  * @toggle: one bit for each endpoint, with ([0] = IN, [1] = OUT) endpoints
379  * @parent: our hub, unless we're the root
380  * @bus: bus we're part of
381  * @ep0: endpoint 0 data (default control pipe)
382  * @dev: generic device interface
383  * @descriptor: USB device descriptor
384  * @config: all of the device's configs
385  * @actconfig: the active configuration
386  * @ep_in: array of IN endpoints
387  * @ep_out: array of OUT endpoints
388  * @rawdescriptors: raw descriptors for each config
389  * @bus_mA: Current available from the bus
390  * @portnum: parent port number (origin 1)
391  * @level: number of USB hub ancestors
392  * @can_submit: URBs may be submitted
393  * @persist_enabled:  USB_PERSIST enabled for this device
394  * @have_langid: whether string_langid is valid
395  * @authorized: policy has said we can use it;
396  *	(user space) policy determines if we authorize this device to be
397  *	used or not. By default, wired USB devices are authorized.
398  *	WUSB devices are not, until we authorize them from user space.
399  *	FIXME -- complete doc
400  * @authenticated: Crypto authentication passed
401  * @wusb: device is Wireless USB
402  * @string_langid: language ID for strings
403  * @product: iProduct string, if present (static)
404  * @manufacturer: iManufacturer string, if present (static)
405  * @serial: iSerialNumber string, if present (static)
406  * @filelist: usbfs files that are open to this device
407  * @usb_classdev: USB class device that was created for usbfs device
408  *	access from userspace
409  * @usbfs_dentry: usbfs dentry entry for the device
410  * @maxchild: number of ports if hub
411  * @children: child devices - USB devices that are attached to this hub
412  * @quirks: quirks of the whole device
413  * @urbnum: number of URBs submitted for the whole device
414  * @active_duration: total time device is not suspended
415  * @connect_time: time device was first connected
416  * @do_remote_wakeup:  remote wakeup should be enabled
417  * @reset_resume: needs reset instead of resume
418  * @wusb_dev: if this is a Wireless USB device, link to the WUSB
419  *	specific data for the device.
420  * @slot_id: Slot ID assigned by xHCI
421  *
422  * Notes:
423  * Usbcore drivers should not set usbdev->state directly.  Instead use
424  * usb_set_device_state().
425  */
426 struct usb_device {
427 	int		devnum;
428 	char		devpath[16];
429 	u32		route;
430 	enum usb_device_state	state;
431 	enum usb_device_speed	speed;
432 
433 	struct usb_tt	*tt;
434 	int		ttport;
435 
436 	unsigned int toggle[2];
437 
438 	struct usb_device *parent;
439 	struct usb_bus *bus;
440 	struct usb_host_endpoint ep0;
441 
442 	struct device dev;
443 
444 	struct usb_device_descriptor descriptor;
445 	struct usb_host_config *config;
446 
447 	struct usb_host_config *actconfig;
448 	struct usb_host_endpoint *ep_in[16];
449 	struct usb_host_endpoint *ep_out[16];
450 
451 	char **rawdescriptors;
452 
453 	unsigned short bus_mA;
454 	u8 portnum;
455 	u8 level;
456 
457 	unsigned can_submit:1;
458 	unsigned persist_enabled:1;
459 	unsigned have_langid:1;
460 	unsigned authorized:1;
461 	unsigned authenticated:1;
462 	unsigned wusb:1;
463 	int string_langid;
464 
465 	/* static strings from the device */
466 	char *product;
467 	char *manufacturer;
468 	char *serial;
469 
470 	struct list_head filelist;
471 #ifdef CONFIG_USB_DEVICE_CLASS
472 	struct device *usb_classdev;
473 #endif
474 #ifdef CONFIG_USB_DEVICEFS
475 	struct dentry *usbfs_dentry;
476 #endif
477 
478 	int maxchild;
479 	struct usb_device *children[USB_MAXCHILDREN];
480 
481 	u32 quirks;
482 	atomic_t urbnum;
483 
484 	unsigned long active_duration;
485 
486 #ifdef CONFIG_PM
487 	unsigned long connect_time;
488 
489 	unsigned do_remote_wakeup:1;
490 	unsigned reset_resume:1;
491 #endif
492 	struct wusb_dev *wusb_dev;
493 	int slot_id;
494 };
495 #define	to_usb_device(d) container_of(d, struct usb_device, dev)
496 
497 static inline struct usb_device *interface_to_usbdev(struct usb_interface *intf)
498 {
499 	return to_usb_device(intf->dev.parent);
500 }
501 
502 extern struct usb_device *usb_get_dev(struct usb_device *dev);
503 extern void usb_put_dev(struct usb_device *dev);
504 
505 /* USB device locking */
506 #define usb_lock_device(udev)		device_lock(&(udev)->dev)
507 #define usb_unlock_device(udev)		device_unlock(&(udev)->dev)
508 #define usb_trylock_device(udev)	device_trylock(&(udev)->dev)
509 extern int usb_lock_device_for_reset(struct usb_device *udev,
510 				     const struct usb_interface *iface);
511 
512 /* USB port reset for device reinitialization */
513 extern int usb_reset_device(struct usb_device *dev);
514 extern void usb_queue_reset_device(struct usb_interface *dev);
515 
516 
517 /* USB autosuspend and autoresume */
518 #ifdef CONFIG_USB_SUSPEND
519 extern void usb_enable_autosuspend(struct usb_device *udev);
520 extern void usb_disable_autosuspend(struct usb_device *udev);
521 
522 extern int usb_autopm_get_interface(struct usb_interface *intf);
523 extern void usb_autopm_put_interface(struct usb_interface *intf);
524 extern int usb_autopm_get_interface_async(struct usb_interface *intf);
525 extern void usb_autopm_put_interface_async(struct usb_interface *intf);
526 extern void usb_autopm_get_interface_no_resume(struct usb_interface *intf);
527 extern void usb_autopm_put_interface_no_suspend(struct usb_interface *intf);
528 
529 static inline void usb_mark_last_busy(struct usb_device *udev)
530 {
531 	pm_runtime_mark_last_busy(&udev->dev);
532 }
533 
534 #else
535 
536 static inline int usb_enable_autosuspend(struct usb_device *udev)
537 { return 0; }
538 static inline int usb_disable_autosuspend(struct usb_device *udev)
539 { return 0; }
540 
541 static inline int usb_autopm_get_interface(struct usb_interface *intf)
542 { return 0; }
543 static inline int usb_autopm_get_interface_async(struct usb_interface *intf)
544 { return 0; }
545 
546 static inline void usb_autopm_put_interface(struct usb_interface *intf)
547 { }
548 static inline void usb_autopm_put_interface_async(struct usb_interface *intf)
549 { }
550 static inline void usb_autopm_get_interface_no_resume(
551 		struct usb_interface *intf)
552 { }
553 static inline void usb_autopm_put_interface_no_suspend(
554 		struct usb_interface *intf)
555 { }
556 static inline void usb_mark_last_busy(struct usb_device *udev)
557 { }
558 #endif
559 
560 /*-------------------------------------------------------------------------*/
561 
562 /* for drivers using iso endpoints */
563 extern int usb_get_current_frame_number(struct usb_device *usb_dev);
564 
565 /* Sets up a group of bulk endpoints to support multiple stream IDs. */
566 extern int usb_alloc_streams(struct usb_interface *interface,
567 		struct usb_host_endpoint **eps, unsigned int num_eps,
568 		unsigned int num_streams, gfp_t mem_flags);
569 
570 /* Reverts a group of bulk endpoints back to not using stream IDs. */
571 extern void usb_free_streams(struct usb_interface *interface,
572 		struct usb_host_endpoint **eps, unsigned int num_eps,
573 		gfp_t mem_flags);
574 
575 /* used these for multi-interface device registration */
576 extern int usb_driver_claim_interface(struct usb_driver *driver,
577 			struct usb_interface *iface, void *priv);
578 
579 /**
580  * usb_interface_claimed - returns true iff an interface is claimed
581  * @iface: the interface being checked
582  *
583  * Returns true (nonzero) iff the interface is claimed, else false (zero).
584  * Callers must own the driver model's usb bus readlock.  So driver
585  * probe() entries don't need extra locking, but other call contexts
586  * may need to explicitly claim that lock.
587  *
588  */
589 static inline int usb_interface_claimed(struct usb_interface *iface)
590 {
591 	return (iface->dev.driver != NULL);
592 }
593 
594 extern void usb_driver_release_interface(struct usb_driver *driver,
595 			struct usb_interface *iface);
596 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
597 					 const struct usb_device_id *id);
598 extern int usb_match_one_id(struct usb_interface *interface,
599 			    const struct usb_device_id *id);
600 
601 extern struct usb_interface *usb_find_interface(struct usb_driver *drv,
602 		int minor);
603 extern struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
604 		unsigned ifnum);
605 extern struct usb_host_interface *usb_altnum_to_altsetting(
606 		const struct usb_interface *intf, unsigned int altnum);
607 extern struct usb_host_interface *usb_find_alt_setting(
608 		struct usb_host_config *config,
609 		unsigned int iface_num,
610 		unsigned int alt_num);
611 
612 
613 /**
614  * usb_make_path - returns stable device path in the usb tree
615  * @dev: the device whose path is being constructed
616  * @buf: where to put the string
617  * @size: how big is "buf"?
618  *
619  * Returns length of the string (> 0) or negative if size was too small.
620  *
621  * This identifier is intended to be "stable", reflecting physical paths in
622  * hardware such as physical bus addresses for host controllers or ports on
623  * USB hubs.  That makes it stay the same until systems are physically
624  * reconfigured, by re-cabling a tree of USB devices or by moving USB host
625  * controllers.  Adding and removing devices, including virtual root hubs
626  * in host controller driver modules, does not change these path identifiers;
627  * neither does rebooting or re-enumerating.  These are more useful identifiers
628  * than changeable ("unstable") ones like bus numbers or device addresses.
629  *
630  * With a partial exception for devices connected to USB 2.0 root hubs, these
631  * identifiers are also predictable.  So long as the device tree isn't changed,
632  * plugging any USB device into a given hub port always gives it the same path.
633  * Because of the use of "companion" controllers, devices connected to ports on
634  * USB 2.0 root hubs (EHCI host controllers) will get one path ID if they are
635  * high speed, and a different one if they are full or low speed.
636  */
637 static inline int usb_make_path(struct usb_device *dev, char *buf, size_t size)
638 {
639 	int actual;
640 	actual = snprintf(buf, size, "usb-%s-%s", dev->bus->bus_name,
641 			  dev->devpath);
642 	return (actual >= (int)size) ? -1 : actual;
643 }
644 
645 /*-------------------------------------------------------------------------*/
646 
647 #define USB_DEVICE_ID_MATCH_DEVICE \
648 		(USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT)
649 #define USB_DEVICE_ID_MATCH_DEV_RANGE \
650 		(USB_DEVICE_ID_MATCH_DEV_LO | USB_DEVICE_ID_MATCH_DEV_HI)
651 #define USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION \
652 		(USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_RANGE)
653 #define USB_DEVICE_ID_MATCH_DEV_INFO \
654 		(USB_DEVICE_ID_MATCH_DEV_CLASS | \
655 		USB_DEVICE_ID_MATCH_DEV_SUBCLASS | \
656 		USB_DEVICE_ID_MATCH_DEV_PROTOCOL)
657 #define USB_DEVICE_ID_MATCH_INT_INFO \
658 		(USB_DEVICE_ID_MATCH_INT_CLASS | \
659 		USB_DEVICE_ID_MATCH_INT_SUBCLASS | \
660 		USB_DEVICE_ID_MATCH_INT_PROTOCOL)
661 
662 /**
663  * USB_DEVICE - macro used to describe a specific usb device
664  * @vend: the 16 bit USB Vendor ID
665  * @prod: the 16 bit USB Product ID
666  *
667  * This macro is used to create a struct usb_device_id that matches a
668  * specific device.
669  */
670 #define USB_DEVICE(vend, prod) \
671 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE, \
672 	.idVendor = (vend), \
673 	.idProduct = (prod)
674 /**
675  * USB_DEVICE_VER - describe a specific usb device with a version range
676  * @vend: the 16 bit USB Vendor ID
677  * @prod: the 16 bit USB Product ID
678  * @lo: the bcdDevice_lo value
679  * @hi: the bcdDevice_hi value
680  *
681  * This macro is used to create a struct usb_device_id that matches a
682  * specific device, with a version range.
683  */
684 #define USB_DEVICE_VER(vend, prod, lo, hi) \
685 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION, \
686 	.idVendor = (vend), \
687 	.idProduct = (prod), \
688 	.bcdDevice_lo = (lo), \
689 	.bcdDevice_hi = (hi)
690 
691 /**
692  * USB_DEVICE_INTERFACE_PROTOCOL - describe a usb device with a specific interface protocol
693  * @vend: the 16 bit USB Vendor ID
694  * @prod: the 16 bit USB Product ID
695  * @pr: bInterfaceProtocol value
696  *
697  * This macro is used to create a struct usb_device_id that matches a
698  * specific interface protocol of devices.
699  */
700 #define USB_DEVICE_INTERFACE_PROTOCOL(vend, prod, pr) \
701 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
702 		       USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
703 	.idVendor = (vend), \
704 	.idProduct = (prod), \
705 	.bInterfaceProtocol = (pr)
706 
707 /**
708  * USB_DEVICE_INFO - macro used to describe a class of usb devices
709  * @cl: bDeviceClass value
710  * @sc: bDeviceSubClass value
711  * @pr: bDeviceProtocol value
712  *
713  * This macro is used to create a struct usb_device_id that matches a
714  * specific class of devices.
715  */
716 #define USB_DEVICE_INFO(cl, sc, pr) \
717 	.match_flags = USB_DEVICE_ID_MATCH_DEV_INFO, \
718 	.bDeviceClass = (cl), \
719 	.bDeviceSubClass = (sc), \
720 	.bDeviceProtocol = (pr)
721 
722 /**
723  * USB_INTERFACE_INFO - macro used to describe a class of usb interfaces
724  * @cl: bInterfaceClass value
725  * @sc: bInterfaceSubClass value
726  * @pr: bInterfaceProtocol value
727  *
728  * This macro is used to create a struct usb_device_id that matches a
729  * specific class of interfaces.
730  */
731 #define USB_INTERFACE_INFO(cl, sc, pr) \
732 	.match_flags = USB_DEVICE_ID_MATCH_INT_INFO, \
733 	.bInterfaceClass = (cl), \
734 	.bInterfaceSubClass = (sc), \
735 	.bInterfaceProtocol = (pr)
736 
737 /**
738  * USB_DEVICE_AND_INTERFACE_INFO - describe a specific usb device with a class of usb interfaces
739  * @vend: the 16 bit USB Vendor ID
740  * @prod: the 16 bit USB Product ID
741  * @cl: bInterfaceClass value
742  * @sc: bInterfaceSubClass value
743  * @pr: bInterfaceProtocol value
744  *
745  * This macro is used to create a struct usb_device_id that matches a
746  * specific device with a specific class of interfaces.
747  *
748  * This is especially useful when explicitly matching devices that have
749  * vendor specific bDeviceClass values, but standards-compliant interfaces.
750  */
751 #define USB_DEVICE_AND_INTERFACE_INFO(vend, prod, cl, sc, pr) \
752 	.match_flags = USB_DEVICE_ID_MATCH_INT_INFO \
753 		| USB_DEVICE_ID_MATCH_DEVICE, \
754 	.idVendor = (vend), \
755 	.idProduct = (prod), \
756 	.bInterfaceClass = (cl), \
757 	.bInterfaceSubClass = (sc), \
758 	.bInterfaceProtocol = (pr)
759 
760 /* ----------------------------------------------------------------------- */
761 
762 /* Stuff for dynamic usb ids */
763 struct usb_dynids {
764 	spinlock_t lock;
765 	struct list_head list;
766 };
767 
768 struct usb_dynid {
769 	struct list_head node;
770 	struct usb_device_id id;
771 };
772 
773 extern ssize_t usb_store_new_id(struct usb_dynids *dynids,
774 				struct device_driver *driver,
775 				const char *buf, size_t count);
776 
777 /**
778  * struct usbdrv_wrap - wrapper for driver-model structure
779  * @driver: The driver-model core driver structure.
780  * @for_devices: Non-zero for device drivers, 0 for interface drivers.
781  */
782 struct usbdrv_wrap {
783 	struct device_driver driver;
784 	int for_devices;
785 };
786 
787 /**
788  * struct usb_driver - identifies USB interface driver to usbcore
789  * @name: The driver name should be unique among USB drivers,
790  *	and should normally be the same as the module name.
791  * @probe: Called to see if the driver is willing to manage a particular
792  *	interface on a device.  If it is, probe returns zero and uses
793  *	usb_set_intfdata() to associate driver-specific data with the
794  *	interface.  It may also use usb_set_interface() to specify the
795  *	appropriate altsetting.  If unwilling to manage the interface,
796  *	return -ENODEV, if genuine IO errors occurred, an appropriate
797  *	negative errno value.
798  * @disconnect: Called when the interface is no longer accessible, usually
799  *	because its device has been (or is being) disconnected or the
800  *	driver module is being unloaded.
801  * @unlocked_ioctl: Used for drivers that want to talk to userspace through
802  *	the "usbfs" filesystem.  This lets devices provide ways to
803  *	expose information to user space regardless of where they
804  *	do (or don't) show up otherwise in the filesystem.
805  * @suspend: Called when the device is going to be suspended by the system.
806  * @resume: Called when the device is being resumed by the system.
807  * @reset_resume: Called when the suspended device has been reset instead
808  *	of being resumed.
809  * @pre_reset: Called by usb_reset_device() when the device
810  *	is about to be reset.
811  * @post_reset: Called by usb_reset_device() after the device
812  *	has been reset
813  * @id_table: USB drivers use ID table to support hotplugging.
814  *	Export this with MODULE_DEVICE_TABLE(usb,...).  This must be set
815  *	or your driver's probe function will never get called.
816  * @dynids: used internally to hold the list of dynamically added device
817  *	ids for this driver.
818  * @drvwrap: Driver-model core structure wrapper.
819  * @no_dynamic_id: if set to 1, the USB core will not allow dynamic ids to be
820  *	added to this driver by preventing the sysfs file from being created.
821  * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
822  *	for interfaces bound to this driver.
823  * @soft_unbind: if set to 1, the USB core will not kill URBs and disable
824  *	endpoints before calling the driver's disconnect method.
825  *
826  * USB interface drivers must provide a name, probe() and disconnect()
827  * methods, and an id_table.  Other driver fields are optional.
828  *
829  * The id_table is used in hotplugging.  It holds a set of descriptors,
830  * and specialized data may be associated with each entry.  That table
831  * is used by both user and kernel mode hotplugging support.
832  *
833  * The probe() and disconnect() methods are called in a context where
834  * they can sleep, but they should avoid abusing the privilege.  Most
835  * work to connect to a device should be done when the device is opened,
836  * and undone at the last close.  The disconnect code needs to address
837  * concurrency issues with respect to open() and close() methods, as
838  * well as forcing all pending I/O requests to complete (by unlinking
839  * them as necessary, and blocking until the unlinks complete).
840  */
841 struct usb_driver {
842 	const char *name;
843 
844 	int (*probe) (struct usb_interface *intf,
845 		      const struct usb_device_id *id);
846 
847 	void (*disconnect) (struct usb_interface *intf);
848 
849 	int (*unlocked_ioctl) (struct usb_interface *intf, unsigned int code,
850 			void *buf);
851 
852 	int (*suspend) (struct usb_interface *intf, pm_message_t message);
853 	int (*resume) (struct usb_interface *intf);
854 	int (*reset_resume)(struct usb_interface *intf);
855 
856 	int (*pre_reset)(struct usb_interface *intf);
857 	int (*post_reset)(struct usb_interface *intf);
858 
859 	const struct usb_device_id *id_table;
860 
861 	struct usb_dynids dynids;
862 	struct usbdrv_wrap drvwrap;
863 	unsigned int no_dynamic_id:1;
864 	unsigned int supports_autosuspend:1;
865 	unsigned int soft_unbind:1;
866 };
867 #define	to_usb_driver(d) container_of(d, struct usb_driver, drvwrap.driver)
868 
869 /**
870  * struct usb_device_driver - identifies USB device driver to usbcore
871  * @name: The driver name should be unique among USB drivers,
872  *	and should normally be the same as the module name.
873  * @probe: Called to see if the driver is willing to manage a particular
874  *	device.  If it is, probe returns zero and uses dev_set_drvdata()
875  *	to associate driver-specific data with the device.  If unwilling
876  *	to manage the device, return a negative errno value.
877  * @disconnect: Called when the device is no longer accessible, usually
878  *	because it has been (or is being) disconnected or the driver's
879  *	module is being unloaded.
880  * @suspend: Called when the device is going to be suspended by the system.
881  * @resume: Called when the device is being resumed by the system.
882  * @drvwrap: Driver-model core structure wrapper.
883  * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
884  *	for devices bound to this driver.
885  *
886  * USB drivers must provide all the fields listed above except drvwrap.
887  */
888 struct usb_device_driver {
889 	const char *name;
890 
891 	int (*probe) (struct usb_device *udev);
892 	void (*disconnect) (struct usb_device *udev);
893 
894 	int (*suspend) (struct usb_device *udev, pm_message_t message);
895 	int (*resume) (struct usb_device *udev, pm_message_t message);
896 	struct usbdrv_wrap drvwrap;
897 	unsigned int supports_autosuspend:1;
898 };
899 #define	to_usb_device_driver(d) container_of(d, struct usb_device_driver, \
900 		drvwrap.driver)
901 
902 extern struct bus_type usb_bus_type;
903 
904 /**
905  * struct usb_class_driver - identifies a USB driver that wants to use the USB major number
906  * @name: the usb class device name for this driver.  Will show up in sysfs.
907  * @devnode: Callback to provide a naming hint for a possible
908  *	device node to create.
909  * @fops: pointer to the struct file_operations of this driver.
910  * @minor_base: the start of the minor range for this driver.
911  *
912  * This structure is used for the usb_register_dev() and
913  * usb_unregister_dev() functions, to consolidate a number of the
914  * parameters used for them.
915  */
916 struct usb_class_driver {
917 	char *name;
918 	char *(*devnode)(struct device *dev, mode_t *mode);
919 	const struct file_operations *fops;
920 	int minor_base;
921 };
922 
923 /*
924  * use these in module_init()/module_exit()
925  * and don't forget MODULE_DEVICE_TABLE(usb, ...)
926  */
927 extern int usb_register_driver(struct usb_driver *, struct module *,
928 			       const char *);
929 static inline int usb_register(struct usb_driver *driver)
930 {
931 	return usb_register_driver(driver, THIS_MODULE, KBUILD_MODNAME);
932 }
933 extern void usb_deregister(struct usb_driver *);
934 
935 extern int usb_register_device_driver(struct usb_device_driver *,
936 			struct module *);
937 extern void usb_deregister_device_driver(struct usb_device_driver *);
938 
939 extern int usb_register_dev(struct usb_interface *intf,
940 			    struct usb_class_driver *class_driver);
941 extern void usb_deregister_dev(struct usb_interface *intf,
942 			       struct usb_class_driver *class_driver);
943 
944 extern int usb_disabled(void);
945 
946 /* ----------------------------------------------------------------------- */
947 
948 /*
949  * URB support, for asynchronous request completions
950  */
951 
952 /*
953  * urb->transfer_flags:
954  *
955  * Note: URB_DIR_IN/OUT is automatically set in usb_submit_urb().
956  */
957 #define URB_SHORT_NOT_OK	0x0001	/* report short reads as errors */
958 #define URB_ISO_ASAP		0x0002	/* iso-only, urb->start_frame
959 					 * ignored */
960 #define URB_NO_TRANSFER_DMA_MAP	0x0004	/* urb->transfer_dma valid on submit */
961 #define URB_NO_FSBR		0x0020	/* UHCI-specific */
962 #define URB_ZERO_PACKET		0x0040	/* Finish bulk OUT with short packet */
963 #define URB_NO_INTERRUPT	0x0080	/* HINT: no non-error interrupt
964 					 * needed */
965 #define URB_FREE_BUFFER		0x0100	/* Free transfer buffer with the URB */
966 
967 /* The following flags are used internally by usbcore and HCDs */
968 #define URB_DIR_IN		0x0200	/* Transfer from device to host */
969 #define URB_DIR_OUT		0
970 #define URB_DIR_MASK		URB_DIR_IN
971 
972 #define URB_DMA_MAP_SINGLE	0x00010000	/* Non-scatter-gather mapping */
973 #define URB_DMA_MAP_PAGE	0x00020000	/* HCD-unsupported S-G */
974 #define URB_DMA_MAP_SG		0x00040000	/* HCD-supported S-G */
975 #define URB_MAP_LOCAL		0x00080000	/* HCD-local-memory mapping */
976 #define URB_SETUP_MAP_SINGLE	0x00100000	/* Setup packet DMA mapped */
977 #define URB_SETUP_MAP_LOCAL	0x00200000	/* HCD-local setup packet */
978 #define URB_DMA_SG_COMBINED	0x00400000	/* S-G entries were combined */
979 #define URB_ALIGNED_TEMP_BUFFER	0x00800000	/* Temp buffer was alloc'd */
980 
981 struct usb_iso_packet_descriptor {
982 	unsigned int offset;
983 	unsigned int length;		/* expected length */
984 	unsigned int actual_length;
985 	int status;
986 };
987 
988 struct urb;
989 
990 struct usb_anchor {
991 	struct list_head urb_list;
992 	wait_queue_head_t wait;
993 	spinlock_t lock;
994 	unsigned int poisoned:1;
995 };
996 
997 static inline void init_usb_anchor(struct usb_anchor *anchor)
998 {
999 	INIT_LIST_HEAD(&anchor->urb_list);
1000 	init_waitqueue_head(&anchor->wait);
1001 	spin_lock_init(&anchor->lock);
1002 }
1003 
1004 typedef void (*usb_complete_t)(struct urb *);
1005 
1006 /**
1007  * struct urb - USB Request Block
1008  * @urb_list: For use by current owner of the URB.
1009  * @anchor_list: membership in the list of an anchor
1010  * @anchor: to anchor URBs to a common mooring
1011  * @ep: Points to the endpoint's data structure.  Will eventually
1012  *	replace @pipe.
1013  * @pipe: Holds endpoint number, direction, type, and more.
1014  *	Create these values with the eight macros available;
1015  *	usb_{snd,rcv}TYPEpipe(dev,endpoint), where the TYPE is "ctrl"
1016  *	(control), "bulk", "int" (interrupt), or "iso" (isochronous).
1017  *	For example usb_sndbulkpipe() or usb_rcvintpipe().  Endpoint
1018  *	numbers range from zero to fifteen.  Note that "in" endpoint two
1019  *	is a different endpoint (and pipe) from "out" endpoint two.
1020  *	The current configuration controls the existence, type, and
1021  *	maximum packet size of any given endpoint.
1022  * @stream_id: the endpoint's stream ID for bulk streams
1023  * @dev: Identifies the USB device to perform the request.
1024  * @status: This is read in non-iso completion functions to get the
1025  *	status of the particular request.  ISO requests only use it
1026  *	to tell whether the URB was unlinked; detailed status for
1027  *	each frame is in the fields of the iso_frame-desc.
1028  * @transfer_flags: A variety of flags may be used to affect how URB
1029  *	submission, unlinking, or operation are handled.  Different
1030  *	kinds of URB can use different flags.
1031  * @transfer_buffer:  This identifies the buffer to (or from) which the I/O
1032  *	request will be performed unless URB_NO_TRANSFER_DMA_MAP is set
1033  *	(however, do not leave garbage in transfer_buffer even then).
1034  *	This buffer must be suitable for DMA; allocate it with
1035  *	kmalloc() or equivalent.  For transfers to "in" endpoints, contents
1036  *	of this buffer will be modified.  This buffer is used for the data
1037  *	stage of control transfers.
1038  * @transfer_dma: When transfer_flags includes URB_NO_TRANSFER_DMA_MAP,
1039  *	the device driver is saying that it provided this DMA address,
1040  *	which the host controller driver should use in preference to the
1041  *	transfer_buffer.
1042  * @sg: scatter gather buffer list
1043  * @num_sgs: number of entries in the sg list
1044  * @transfer_buffer_length: How big is transfer_buffer.  The transfer may
1045  *	be broken up into chunks according to the current maximum packet
1046  *	size for the endpoint, which is a function of the configuration
1047  *	and is encoded in the pipe.  When the length is zero, neither
1048  *	transfer_buffer nor transfer_dma is used.
1049  * @actual_length: This is read in non-iso completion functions, and
1050  *	it tells how many bytes (out of transfer_buffer_length) were
1051  *	transferred.  It will normally be the same as requested, unless
1052  *	either an error was reported or a short read was performed.
1053  *	The URB_SHORT_NOT_OK transfer flag may be used to make such
1054  *	short reads be reported as errors.
1055  * @setup_packet: Only used for control transfers, this points to eight bytes
1056  *	of setup data.  Control transfers always start by sending this data
1057  *	to the device.  Then transfer_buffer is read or written, if needed.
1058  * @setup_dma: DMA pointer for the setup packet.  The caller must not use
1059  *	this field; setup_packet must point to a valid buffer.
1060  * @start_frame: Returns the initial frame for isochronous transfers.
1061  * @number_of_packets: Lists the number of ISO transfer buffers.
1062  * @interval: Specifies the polling interval for interrupt or isochronous
1063  *	transfers.  The units are frames (milliseconds) for full and low
1064  *	speed devices, and microframes (1/8 millisecond) for highspeed
1065  *	and SuperSpeed devices.
1066  * @error_count: Returns the number of ISO transfers that reported errors.
1067  * @context: For use in completion functions.  This normally points to
1068  *	request-specific driver context.
1069  * @complete: Completion handler. This URB is passed as the parameter to the
1070  *	completion function.  The completion function may then do what
1071  *	it likes with the URB, including resubmitting or freeing it.
1072  * @iso_frame_desc: Used to provide arrays of ISO transfer buffers and to
1073  *	collect the transfer status for each buffer.
1074  *
1075  * This structure identifies USB transfer requests.  URBs must be allocated by
1076  * calling usb_alloc_urb() and freed with a call to usb_free_urb().
1077  * Initialization may be done using various usb_fill_*_urb() functions.  URBs
1078  * are submitted using usb_submit_urb(), and pending requests may be canceled
1079  * using usb_unlink_urb() or usb_kill_urb().
1080  *
1081  * Data Transfer Buffers:
1082  *
1083  * Normally drivers provide I/O buffers allocated with kmalloc() or otherwise
1084  * taken from the general page pool.  That is provided by transfer_buffer
1085  * (control requests also use setup_packet), and host controller drivers
1086  * perform a dma mapping (and unmapping) for each buffer transferred.  Those
1087  * mapping operations can be expensive on some platforms (perhaps using a dma
1088  * bounce buffer or talking to an IOMMU),
1089  * although they're cheap on commodity x86 and ppc hardware.
1090  *
1091  * Alternatively, drivers may pass the URB_NO_TRANSFER_DMA_MAP transfer flag,
1092  * which tells the host controller driver that no such mapping is needed for
1093  * the transfer_buffer since
1094  * the device driver is DMA-aware.  For example, a device driver might
1095  * allocate a DMA buffer with usb_alloc_coherent() or call usb_buffer_map().
1096  * When this transfer flag is provided, host controller drivers will
1097  * attempt to use the dma address found in the transfer_dma
1098  * field rather than determining a dma address themselves.
1099  *
1100  * Note that transfer_buffer must still be set if the controller
1101  * does not support DMA (as indicated by bus.uses_dma) and when talking
1102  * to root hub. If you have to trasfer between highmem zone and the device
1103  * on such controller, create a bounce buffer or bail out with an error.
1104  * If transfer_buffer cannot be set (is in highmem) and the controller is DMA
1105  * capable, assign NULL to it, so that usbmon knows not to use the value.
1106  * The setup_packet must always be set, so it cannot be located in highmem.
1107  *
1108  * Initialization:
1109  *
1110  * All URBs submitted must initialize the dev, pipe, transfer_flags (may be
1111  * zero), and complete fields.  All URBs must also initialize
1112  * transfer_buffer and transfer_buffer_length.  They may provide the
1113  * URB_SHORT_NOT_OK transfer flag, indicating that short reads are
1114  * to be treated as errors; that flag is invalid for write requests.
1115  *
1116  * Bulk URBs may
1117  * use the URB_ZERO_PACKET transfer flag, indicating that bulk OUT transfers
1118  * should always terminate with a short packet, even if it means adding an
1119  * extra zero length packet.
1120  *
1121  * Control URBs must provide a valid pointer in the setup_packet field.
1122  * Unlike the transfer_buffer, the setup_packet may not be mapped for DMA
1123  * beforehand.
1124  *
1125  * Interrupt URBs must provide an interval, saying how often (in milliseconds
1126  * or, for highspeed devices, 125 microsecond units)
1127  * to poll for transfers.  After the URB has been submitted, the interval
1128  * field reflects how the transfer was actually scheduled.
1129  * The polling interval may be more frequent than requested.
1130  * For example, some controllers have a maximum interval of 32 milliseconds,
1131  * while others support intervals of up to 1024 milliseconds.
1132  * Isochronous URBs also have transfer intervals.  (Note that for isochronous
1133  * endpoints, as well as high speed interrupt endpoints, the encoding of
1134  * the transfer interval in the endpoint descriptor is logarithmic.
1135  * Device drivers must convert that value to linear units themselves.)
1136  *
1137  * Isochronous URBs normally use the URB_ISO_ASAP transfer flag, telling
1138  * the host controller to schedule the transfer as soon as bandwidth
1139  * utilization allows, and then set start_frame to reflect the actual frame
1140  * selected during submission.  Otherwise drivers must specify the start_frame
1141  * and handle the case where the transfer can't begin then.  However, drivers
1142  * won't know how bandwidth is currently allocated, and while they can
1143  * find the current frame using usb_get_current_frame_number () they can't
1144  * know the range for that frame number.  (Ranges for frame counter values
1145  * are HC-specific, and can go from 256 to 65536 frames from "now".)
1146  *
1147  * Isochronous URBs have a different data transfer model, in part because
1148  * the quality of service is only "best effort".  Callers provide specially
1149  * allocated URBs, with number_of_packets worth of iso_frame_desc structures
1150  * at the end.  Each such packet is an individual ISO transfer.  Isochronous
1151  * URBs are normally queued, submitted by drivers to arrange that
1152  * transfers are at least double buffered, and then explicitly resubmitted
1153  * in completion handlers, so
1154  * that data (such as audio or video) streams at as constant a rate as the
1155  * host controller scheduler can support.
1156  *
1157  * Completion Callbacks:
1158  *
1159  * The completion callback is made in_interrupt(), and one of the first
1160  * things that a completion handler should do is check the status field.
1161  * The status field is provided for all URBs.  It is used to report
1162  * unlinked URBs, and status for all non-ISO transfers.  It should not
1163  * be examined before the URB is returned to the completion handler.
1164  *
1165  * The context field is normally used to link URBs back to the relevant
1166  * driver or request state.
1167  *
1168  * When the completion callback is invoked for non-isochronous URBs, the
1169  * actual_length field tells how many bytes were transferred.  This field
1170  * is updated even when the URB terminated with an error or was unlinked.
1171  *
1172  * ISO transfer status is reported in the status and actual_length fields
1173  * of the iso_frame_desc array, and the number of errors is reported in
1174  * error_count.  Completion callbacks for ISO transfers will normally
1175  * (re)submit URBs to ensure a constant transfer rate.
1176  *
1177  * Note that even fields marked "public" should not be touched by the driver
1178  * when the urb is owned by the hcd, that is, since the call to
1179  * usb_submit_urb() till the entry into the completion routine.
1180  */
1181 struct urb {
1182 	/* private: usb core and host controller only fields in the urb */
1183 	struct kref kref;		/* reference count of the URB */
1184 	void *hcpriv;			/* private data for host controller */
1185 	atomic_t use_count;		/* concurrent submissions counter */
1186 	atomic_t reject;		/* submissions will fail */
1187 	int unlinked;			/* unlink error code */
1188 
1189 	/* public: documented fields in the urb that can be used by drivers */
1190 	struct list_head urb_list;	/* list head for use by the urb's
1191 					 * current owner */
1192 	struct list_head anchor_list;	/* the URB may be anchored */
1193 	struct usb_anchor *anchor;
1194 	struct usb_device *dev;		/* (in) pointer to associated device */
1195 	struct usb_host_endpoint *ep;	/* (internal) pointer to endpoint */
1196 	unsigned int pipe;		/* (in) pipe information */
1197 	unsigned int stream_id;		/* (in) stream ID */
1198 	int status;			/* (return) non-ISO status */
1199 	unsigned int transfer_flags;	/* (in) URB_SHORT_NOT_OK | ...*/
1200 	void *transfer_buffer;		/* (in) associated data buffer */
1201 	dma_addr_t transfer_dma;	/* (in) dma addr for transfer_buffer */
1202 	struct scatterlist *sg;		/* (in) scatter gather buffer list */
1203 	int num_sgs;			/* (in) number of entries in the sg list */
1204 	u32 transfer_buffer_length;	/* (in) data buffer length */
1205 	u32 actual_length;		/* (return) actual transfer length */
1206 	unsigned char *setup_packet;	/* (in) setup packet (control only) */
1207 	dma_addr_t setup_dma;		/* (in) dma addr for setup_packet */
1208 	int start_frame;		/* (modify) start frame (ISO) */
1209 	int number_of_packets;		/* (in) number of ISO packets */
1210 	int interval;			/* (modify) transfer interval
1211 					 * (INT/ISO) */
1212 	int error_count;		/* (return) number of ISO errors */
1213 	void *context;			/* (in) context for completion */
1214 	usb_complete_t complete;	/* (in) completion routine */
1215 	struct usb_iso_packet_descriptor iso_frame_desc[0];
1216 					/* (in) ISO ONLY */
1217 };
1218 
1219 /* ----------------------------------------------------------------------- */
1220 
1221 /**
1222  * usb_fill_control_urb - initializes a control urb
1223  * @urb: pointer to the urb to initialize.
1224  * @dev: pointer to the struct usb_device for this urb.
1225  * @pipe: the endpoint pipe
1226  * @setup_packet: pointer to the setup_packet buffer
1227  * @transfer_buffer: pointer to the transfer buffer
1228  * @buffer_length: length of the transfer buffer
1229  * @complete_fn: pointer to the usb_complete_t function
1230  * @context: what to set the urb context to.
1231  *
1232  * Initializes a control urb with the proper information needed to submit
1233  * it to a device.
1234  */
1235 static inline void usb_fill_control_urb(struct urb *urb,
1236 					struct usb_device *dev,
1237 					unsigned int pipe,
1238 					unsigned char *setup_packet,
1239 					void *transfer_buffer,
1240 					int buffer_length,
1241 					usb_complete_t complete_fn,
1242 					void *context)
1243 {
1244 	urb->dev = dev;
1245 	urb->pipe = pipe;
1246 	urb->setup_packet = setup_packet;
1247 	urb->transfer_buffer = transfer_buffer;
1248 	urb->transfer_buffer_length = buffer_length;
1249 	urb->complete = complete_fn;
1250 	urb->context = context;
1251 }
1252 
1253 /**
1254  * usb_fill_bulk_urb - macro to help initialize a bulk urb
1255  * @urb: pointer to the urb to initialize.
1256  * @dev: pointer to the struct usb_device for this urb.
1257  * @pipe: the endpoint pipe
1258  * @transfer_buffer: pointer to the transfer buffer
1259  * @buffer_length: length of the transfer buffer
1260  * @complete_fn: pointer to the usb_complete_t function
1261  * @context: what to set the urb context to.
1262  *
1263  * Initializes a bulk urb with the proper information needed to submit it
1264  * to a device.
1265  */
1266 static inline void usb_fill_bulk_urb(struct urb *urb,
1267 				     struct usb_device *dev,
1268 				     unsigned int pipe,
1269 				     void *transfer_buffer,
1270 				     int buffer_length,
1271 				     usb_complete_t complete_fn,
1272 				     void *context)
1273 {
1274 	urb->dev = dev;
1275 	urb->pipe = pipe;
1276 	urb->transfer_buffer = transfer_buffer;
1277 	urb->transfer_buffer_length = buffer_length;
1278 	urb->complete = complete_fn;
1279 	urb->context = context;
1280 }
1281 
1282 /**
1283  * usb_fill_int_urb - macro to help initialize a interrupt urb
1284  * @urb: pointer to the urb to initialize.
1285  * @dev: pointer to the struct usb_device for this urb.
1286  * @pipe: the endpoint pipe
1287  * @transfer_buffer: pointer to the transfer buffer
1288  * @buffer_length: length of the transfer buffer
1289  * @complete_fn: pointer to the usb_complete_t function
1290  * @context: what to set the urb context to.
1291  * @interval: what to set the urb interval to, encoded like
1292  *	the endpoint descriptor's bInterval value.
1293  *
1294  * Initializes a interrupt urb with the proper information needed to submit
1295  * it to a device.
1296  *
1297  * Note that High Speed and SuperSpeed interrupt endpoints use a logarithmic
1298  * encoding of the endpoint interval, and express polling intervals in
1299  * microframes (eight per millisecond) rather than in frames (one per
1300  * millisecond).
1301  *
1302  * Wireless USB also uses the logarithmic encoding, but specifies it in units of
1303  * 128us instead of 125us.  For Wireless USB devices, the interval is passed
1304  * through to the host controller, rather than being translated into microframe
1305  * units.
1306  */
1307 static inline void usb_fill_int_urb(struct urb *urb,
1308 				    struct usb_device *dev,
1309 				    unsigned int pipe,
1310 				    void *transfer_buffer,
1311 				    int buffer_length,
1312 				    usb_complete_t complete_fn,
1313 				    void *context,
1314 				    int interval)
1315 {
1316 	urb->dev = dev;
1317 	urb->pipe = pipe;
1318 	urb->transfer_buffer = transfer_buffer;
1319 	urb->transfer_buffer_length = buffer_length;
1320 	urb->complete = complete_fn;
1321 	urb->context = context;
1322 	if (dev->speed == USB_SPEED_HIGH || dev->speed == USB_SPEED_SUPER)
1323 		urb->interval = 1 << (interval - 1);
1324 	else
1325 		urb->interval = interval;
1326 	urb->start_frame = -1;
1327 }
1328 
1329 extern void usb_init_urb(struct urb *urb);
1330 extern struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags);
1331 extern void usb_free_urb(struct urb *urb);
1332 #define usb_put_urb usb_free_urb
1333 extern struct urb *usb_get_urb(struct urb *urb);
1334 extern int usb_submit_urb(struct urb *urb, gfp_t mem_flags);
1335 extern int usb_unlink_urb(struct urb *urb);
1336 extern void usb_kill_urb(struct urb *urb);
1337 extern void usb_poison_urb(struct urb *urb);
1338 extern void usb_unpoison_urb(struct urb *urb);
1339 extern void usb_kill_anchored_urbs(struct usb_anchor *anchor);
1340 extern void usb_poison_anchored_urbs(struct usb_anchor *anchor);
1341 extern void usb_unpoison_anchored_urbs(struct usb_anchor *anchor);
1342 extern void usb_unlink_anchored_urbs(struct usb_anchor *anchor);
1343 extern void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor);
1344 extern void usb_unanchor_urb(struct urb *urb);
1345 extern int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor,
1346 					 unsigned int timeout);
1347 extern struct urb *usb_get_from_anchor(struct usb_anchor *anchor);
1348 extern void usb_scuttle_anchored_urbs(struct usb_anchor *anchor);
1349 extern int usb_anchor_empty(struct usb_anchor *anchor);
1350 
1351 /**
1352  * usb_urb_dir_in - check if an URB describes an IN transfer
1353  * @urb: URB to be checked
1354  *
1355  * Returns 1 if @urb describes an IN transfer (device-to-host),
1356  * otherwise 0.
1357  */
1358 static inline int usb_urb_dir_in(struct urb *urb)
1359 {
1360 	return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_IN;
1361 }
1362 
1363 /**
1364  * usb_urb_dir_out - check if an URB describes an OUT transfer
1365  * @urb: URB to be checked
1366  *
1367  * Returns 1 if @urb describes an OUT transfer (host-to-device),
1368  * otherwise 0.
1369  */
1370 static inline int usb_urb_dir_out(struct urb *urb)
1371 {
1372 	return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_OUT;
1373 }
1374 
1375 void *usb_alloc_coherent(struct usb_device *dev, size_t size,
1376 	gfp_t mem_flags, dma_addr_t *dma);
1377 void usb_free_coherent(struct usb_device *dev, size_t size,
1378 	void *addr, dma_addr_t dma);
1379 
1380 #if 0
1381 struct urb *usb_buffer_map(struct urb *urb);
1382 void usb_buffer_dmasync(struct urb *urb);
1383 void usb_buffer_unmap(struct urb *urb);
1384 #endif
1385 
1386 struct scatterlist;
1387 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
1388 		      struct scatterlist *sg, int nents);
1389 #if 0
1390 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
1391 			   struct scatterlist *sg, int n_hw_ents);
1392 #endif
1393 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
1394 			 struct scatterlist *sg, int n_hw_ents);
1395 
1396 /*-------------------------------------------------------------------*
1397  *                         SYNCHRONOUS CALL SUPPORT                  *
1398  *-------------------------------------------------------------------*/
1399 
1400 extern int usb_control_msg(struct usb_device *dev, unsigned int pipe,
1401 	__u8 request, __u8 requesttype, __u16 value, __u16 index,
1402 	void *data, __u16 size, int timeout);
1403 extern int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
1404 	void *data, int len, int *actual_length, int timeout);
1405 extern int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
1406 	void *data, int len, int *actual_length,
1407 	int timeout);
1408 
1409 /* wrappers around usb_control_msg() for the most common standard requests */
1410 extern int usb_get_descriptor(struct usb_device *dev, unsigned char desctype,
1411 	unsigned char descindex, void *buf, int size);
1412 extern int usb_get_status(struct usb_device *dev,
1413 	int type, int target, void *data);
1414 extern int usb_string(struct usb_device *dev, int index,
1415 	char *buf, size_t size);
1416 
1417 /* wrappers that also update important state inside usbcore */
1418 extern int usb_clear_halt(struct usb_device *dev, int pipe);
1419 extern int usb_reset_configuration(struct usb_device *dev);
1420 extern int usb_set_interface(struct usb_device *dev, int ifnum, int alternate);
1421 extern void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr);
1422 
1423 /* this request isn't really synchronous, but it belongs with the others */
1424 extern int usb_driver_set_configuration(struct usb_device *udev, int config);
1425 
1426 /*
1427  * timeouts, in milliseconds, used for sending/receiving control messages
1428  * they typically complete within a few frames (msec) after they're issued
1429  * USB identifies 5 second timeouts, maybe more in a few cases, and a few
1430  * slow devices (like some MGE Ellipse UPSes) actually push that limit.
1431  */
1432 #define USB_CTRL_GET_TIMEOUT	5000
1433 #define USB_CTRL_SET_TIMEOUT	5000
1434 
1435 
1436 /**
1437  * struct usb_sg_request - support for scatter/gather I/O
1438  * @status: zero indicates success, else negative errno
1439  * @bytes: counts bytes transferred.
1440  *
1441  * These requests are initialized using usb_sg_init(), and then are used
1442  * as request handles passed to usb_sg_wait() or usb_sg_cancel().  Most
1443  * members of the request object aren't for driver access.
1444  *
1445  * The status and bytecount values are valid only after usb_sg_wait()
1446  * returns.  If the status is zero, then the bytecount matches the total
1447  * from the request.
1448  *
1449  * After an error completion, drivers may need to clear a halt condition
1450  * on the endpoint.
1451  */
1452 struct usb_sg_request {
1453 	int			status;
1454 	size_t			bytes;
1455 
1456 	/* private:
1457 	 * members below are private to usbcore,
1458 	 * and are not provided for driver access!
1459 	 */
1460 	spinlock_t		lock;
1461 
1462 	struct usb_device	*dev;
1463 	int			pipe;
1464 
1465 	int			entries;
1466 	struct urb		**urbs;
1467 
1468 	int			count;
1469 	struct completion	complete;
1470 };
1471 
1472 int usb_sg_init(
1473 	struct usb_sg_request	*io,
1474 	struct usb_device	*dev,
1475 	unsigned		pipe,
1476 	unsigned		period,
1477 	struct scatterlist	*sg,
1478 	int			nents,
1479 	size_t			length,
1480 	gfp_t			mem_flags
1481 );
1482 void usb_sg_cancel(struct usb_sg_request *io);
1483 void usb_sg_wait(struct usb_sg_request *io);
1484 
1485 
1486 /* ----------------------------------------------------------------------- */
1487 
1488 /*
1489  * For various legacy reasons, Linux has a small cookie that's paired with
1490  * a struct usb_device to identify an endpoint queue.  Queue characteristics
1491  * are defined by the endpoint's descriptor.  This cookie is called a "pipe",
1492  * an unsigned int encoded as:
1493  *
1494  *  - direction:	bit 7		(0 = Host-to-Device [Out],
1495  *					 1 = Device-to-Host [In] ...
1496  *					like endpoint bEndpointAddress)
1497  *  - device address:	bits 8-14       ... bit positions known to uhci-hcd
1498  *  - endpoint:		bits 15-18      ... bit positions known to uhci-hcd
1499  *  - pipe type:	bits 30-31	(00 = isochronous, 01 = interrupt,
1500  *					 10 = control, 11 = bulk)
1501  *
1502  * Given the device address and endpoint descriptor, pipes are redundant.
1503  */
1504 
1505 /* NOTE:  these are not the standard USB_ENDPOINT_XFER_* values!! */
1506 /* (yet ... they're the values used by usbfs) */
1507 #define PIPE_ISOCHRONOUS		0
1508 #define PIPE_INTERRUPT			1
1509 #define PIPE_CONTROL			2
1510 #define PIPE_BULK			3
1511 
1512 #define usb_pipein(pipe)	((pipe) & USB_DIR_IN)
1513 #define usb_pipeout(pipe)	(!usb_pipein(pipe))
1514 
1515 #define usb_pipedevice(pipe)	(((pipe) >> 8) & 0x7f)
1516 #define usb_pipeendpoint(pipe)	(((pipe) >> 15) & 0xf)
1517 
1518 #define usb_pipetype(pipe)	(((pipe) >> 30) & 3)
1519 #define usb_pipeisoc(pipe)	(usb_pipetype((pipe)) == PIPE_ISOCHRONOUS)
1520 #define usb_pipeint(pipe)	(usb_pipetype((pipe)) == PIPE_INTERRUPT)
1521 #define usb_pipecontrol(pipe)	(usb_pipetype((pipe)) == PIPE_CONTROL)
1522 #define usb_pipebulk(pipe)	(usb_pipetype((pipe)) == PIPE_BULK)
1523 
1524 static inline unsigned int __create_pipe(struct usb_device *dev,
1525 		unsigned int endpoint)
1526 {
1527 	return (dev->devnum << 8) | (endpoint << 15);
1528 }
1529 
1530 /* Create various pipes... */
1531 #define usb_sndctrlpipe(dev, endpoint)	\
1532 	((PIPE_CONTROL << 30) | __create_pipe(dev, endpoint))
1533 #define usb_rcvctrlpipe(dev, endpoint)	\
1534 	((PIPE_CONTROL << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1535 #define usb_sndisocpipe(dev, endpoint)	\
1536 	((PIPE_ISOCHRONOUS << 30) | __create_pipe(dev, endpoint))
1537 #define usb_rcvisocpipe(dev, endpoint)	\
1538 	((PIPE_ISOCHRONOUS << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1539 #define usb_sndbulkpipe(dev, endpoint)	\
1540 	((PIPE_BULK << 30) | __create_pipe(dev, endpoint))
1541 #define usb_rcvbulkpipe(dev, endpoint)	\
1542 	((PIPE_BULK << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1543 #define usb_sndintpipe(dev, endpoint)	\
1544 	((PIPE_INTERRUPT << 30) | __create_pipe(dev, endpoint))
1545 #define usb_rcvintpipe(dev, endpoint)	\
1546 	((PIPE_INTERRUPT << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1547 
1548 static inline struct usb_host_endpoint *
1549 usb_pipe_endpoint(struct usb_device *dev, unsigned int pipe)
1550 {
1551 	struct usb_host_endpoint **eps;
1552 	eps = usb_pipein(pipe) ? dev->ep_in : dev->ep_out;
1553 	return eps[usb_pipeendpoint(pipe)];
1554 }
1555 
1556 /*-------------------------------------------------------------------------*/
1557 
1558 static inline __u16
1559 usb_maxpacket(struct usb_device *udev, int pipe, int is_out)
1560 {
1561 	struct usb_host_endpoint	*ep;
1562 	unsigned			epnum = usb_pipeendpoint(pipe);
1563 
1564 	if (is_out) {
1565 		WARN_ON(usb_pipein(pipe));
1566 		ep = udev->ep_out[epnum];
1567 	} else {
1568 		WARN_ON(usb_pipeout(pipe));
1569 		ep = udev->ep_in[epnum];
1570 	}
1571 	if (!ep)
1572 		return 0;
1573 
1574 	/* NOTE:  only 0x07ff bits are for packet size... */
1575 	return le16_to_cpu(ep->desc.wMaxPacketSize);
1576 }
1577 
1578 /* ----------------------------------------------------------------------- */
1579 
1580 /* Events from the usb core */
1581 #define USB_DEVICE_ADD		0x0001
1582 #define USB_DEVICE_REMOVE	0x0002
1583 #define USB_BUS_ADD		0x0003
1584 #define USB_BUS_REMOVE		0x0004
1585 extern void usb_register_notify(struct notifier_block *nb);
1586 extern void usb_unregister_notify(struct notifier_block *nb);
1587 
1588 #ifdef DEBUG
1589 #define dbg(format, arg...)						\
1590 	printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg)
1591 #else
1592 #define dbg(format, arg...)						\
1593 do {									\
1594 	if (0)								\
1595 		printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
1596 } while (0)
1597 #endif
1598 
1599 #define err(format, arg...)					\
1600 	printk(KERN_ERR KBUILD_MODNAME ": " format "\n", ##arg)
1601 
1602 /* debugfs stuff */
1603 extern struct dentry *usb_debug_root;
1604 
1605 #endif  /* __KERNEL__ */
1606 
1607 #endif
1608