xref: /linux-6.15/include/linux/usb.h (revision 765532c8)
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 
24 struct usb_device;
25 struct usb_driver;
26 struct wusb_dev;
27 
28 /*-------------------------------------------------------------------------*/
29 
30 /*
31  * Host-side wrappers for standard USB descriptors ... these are parsed
32  * from the data provided by devices.  Parsing turns them from a flat
33  * sequence of descriptors into a hierarchy:
34  *
35  *  - devices have one (usually) or more configs;
36  *  - configs have one (often) or more interfaces;
37  *  - interfaces have one (usually) or more settings;
38  *  - each interface setting has zero or (usually) more endpoints.
39  *  - a SuperSpeed endpoint has a companion descriptor
40  *
41  * And there might be other descriptors mixed in with those.
42  *
43  * Devices may also have class-specific or vendor-specific descriptors.
44  */
45 
46 struct ep_device;
47 
48 /**
49  * struct usb_host_endpoint - host-side endpoint descriptor and queue
50  * @desc: descriptor for this endpoint, wMaxPacketSize in native byteorder
51  * @ss_ep_comp: SuperSpeed companion descriptor for this endpoint
52  * @urb_list: urbs queued to this endpoint; maintained by usbcore
53  * @hcpriv: for use by HCD; typically holds hardware dma queue head (QH)
54  *	with one or more transfer descriptors (TDs) per urb
55  * @ep_dev: ep_device for sysfs info
56  * @extra: descriptors following this endpoint in the configuration
57  * @extralen: how many bytes of "extra" are valid
58  * @enabled: URBs may be submitted to this endpoint
59  *
60  * USB requests are always queued to a given endpoint, identified by a
61  * descriptor within an active interface in a given USB configuration.
62  */
63 struct usb_host_endpoint {
64 	struct usb_endpoint_descriptor		desc;
65 	struct usb_ss_ep_comp_descriptor	ss_ep_comp;
66 	struct list_head		urb_list;
67 	void				*hcpriv;
68 	struct ep_device		*ep_dev;	/* For sysfs info */
69 
70 	unsigned char *extra;   /* Extra descriptors */
71 	int extralen;
72 	int enabled;
73 };
74 
75 /* host-side wrapper for one interface setting's parsed descriptors */
76 struct usb_host_interface {
77 	struct usb_interface_descriptor	desc;
78 
79 	/* array of desc.bNumEndpoint endpoints associated with this
80 	 * interface setting.  these will be in no particular order.
81 	 */
82 	struct usb_host_endpoint *endpoint;
83 
84 	char *string;		/* iInterface string, if present */
85 	unsigned char *extra;   /* Extra descriptors */
86 	int extralen;
87 };
88 
89 enum usb_interface_condition {
90 	USB_INTERFACE_UNBOUND = 0,
91 	USB_INTERFACE_BINDING,
92 	USB_INTERFACE_BOUND,
93 	USB_INTERFACE_UNBINDING,
94 };
95 
96 /**
97  * struct usb_interface - what usb device drivers talk to
98  * @altsetting: array of interface structures, one for each alternate
99  *	setting that may be selected.  Each one includes a set of
100  *	endpoint configurations.  They will be in no particular order.
101  * @cur_altsetting: the current altsetting.
102  * @num_altsetting: number of altsettings defined.
103  * @intf_assoc: interface association descriptor
104  * @minor: the minor number assigned to this interface, if this
105  *	interface is bound to a driver that uses the USB major number.
106  *	If this interface does not use the USB major, this field should
107  *	be unused.  The driver should set this value in the probe()
108  *	function of the driver, after it has been assigned a minor
109  *	number from the USB core by calling usb_register_dev().
110  * @condition: binding state of the interface: not bound, binding
111  *	(in probe()), bound to a driver, or unbinding (in disconnect())
112  * @sysfs_files_created: sysfs attributes exist
113  * @ep_devs_created: endpoint child pseudo-devices exist
114  * @unregistering: flag set when the interface is being unregistered
115  * @needs_remote_wakeup: flag set when the driver requires remote-wakeup
116  *	capability during autosuspend.
117  * @needs_altsetting0: flag set when a set-interface request for altsetting 0
118  *	has been deferred.
119  * @needs_binding: flag set when the driver should be re-probed or unbound
120  *	following a reset or suspend operation it doesn't support.
121  * @dev: driver model's view of this device
122  * @usb_dev: if an interface is bound to the USB major, this will point
123  *	to the sysfs representation for that device.
124  * @pm_usage_cnt: PM usage counter for this interface
125  * @reset_ws: Used for scheduling resets from atomic context.
126  * @reset_running: set to 1 if the interface is currently running a
127  *      queued reset so that usb_cancel_queued_reset() doesn't try to
128  *      remove from the workqueue when running inside the worker
129  *      thread. See __usb_queue_reset_device().
130  * @resetting_device: USB core reset the device, so use alt setting 0 as
131  *	current; needs bandwidth alloc after reset.
132  *
133  * USB device drivers attach to interfaces on a physical device.  Each
134  * interface encapsulates a single high level function, such as feeding
135  * an audio stream to a speaker or reporting a change in a volume control.
136  * Many USB devices only have one interface.  The protocol used to talk to
137  * an interface's endpoints can be defined in a usb "class" specification,
138  * or by a product's vendor.  The (default) control endpoint is part of
139  * every interface, but is never listed among the interface's descriptors.
140  *
141  * The driver that is bound to the interface can use standard driver model
142  * calls such as dev_get_drvdata() on the dev member of this structure.
143  *
144  * Each interface may have alternate settings.  The initial configuration
145  * of a device sets altsetting 0, but the device driver can change
146  * that setting using usb_set_interface().  Alternate settings are often
147  * used to control the use of periodic endpoints, such as by having
148  * different endpoints use different amounts of reserved USB bandwidth.
149  * All standards-conformant USB devices that use isochronous endpoints
150  * will use them in non-default settings.
151  *
152  * The USB specification says that alternate setting numbers must run from
153  * 0 to one less than the total number of alternate settings.  But some
154  * devices manage to mess this up, and the structures aren't necessarily
155  * stored in numerical order anyhow.  Use usb_altnum_to_altsetting() to
156  * look up an alternate setting in the altsetting array based on its number.
157  */
158 struct usb_interface {
159 	/* array of alternate settings for this interface,
160 	 * stored in no particular order */
161 	struct usb_host_interface *altsetting;
162 
163 	struct usb_host_interface *cur_altsetting;	/* the currently
164 					 * active alternate setting */
165 	unsigned num_altsetting;	/* number of alternate settings */
166 
167 	/* If there is an interface association descriptor then it will list
168 	 * the associated interfaces */
169 	struct usb_interface_assoc_descriptor *intf_assoc;
170 
171 	int minor;			/* minor number this interface is
172 					 * bound to */
173 	enum usb_interface_condition condition;		/* state of binding */
174 	unsigned sysfs_files_created:1;	/* the sysfs attributes exist */
175 	unsigned ep_devs_created:1;	/* endpoint "devices" exist */
176 	unsigned unregistering:1;	/* unregistration is in progress */
177 	unsigned needs_remote_wakeup:1;	/* driver requires remote wakeup */
178 	unsigned needs_altsetting0:1;	/* switch to altsetting 0 is pending */
179 	unsigned needs_binding:1;	/* needs delayed unbind/rebind */
180 	unsigned reset_running:1;
181 	unsigned resetting_device:1;	/* true: bandwidth alloc after reset */
182 
183 	struct device dev;		/* interface specific device info */
184 	struct device *usb_dev;
185 	atomic_t pm_usage_cnt;		/* usage counter for autosuspend */
186 	struct work_struct reset_ws;	/* for resets in atomic context */
187 };
188 #define	to_usb_interface(d) container_of(d, struct usb_interface, dev)
189 
190 static inline void *usb_get_intfdata(struct usb_interface *intf)
191 {
192 	return dev_get_drvdata(&intf->dev);
193 }
194 
195 static inline void usb_set_intfdata(struct usb_interface *intf, void *data)
196 {
197 	dev_set_drvdata(&intf->dev, data);
198 }
199 
200 struct usb_interface *usb_get_intf(struct usb_interface *intf);
201 void usb_put_intf(struct usb_interface *intf);
202 
203 /* this maximum is arbitrary */
204 #define USB_MAXINTERFACES	32
205 #define USB_MAXIADS		(USB_MAXINTERFACES/2)
206 
207 /**
208  * struct usb_interface_cache - long-term representation of a device interface
209  * @num_altsetting: number of altsettings defined.
210  * @ref: reference counter.
211  * @altsetting: variable-length array of interface structures, one for
212  *	each alternate setting that may be selected.  Each one includes a
213  *	set of endpoint configurations.  They will be in no particular order.
214  *
215  * These structures persist for the lifetime of a usb_device, unlike
216  * struct usb_interface (which persists only as long as its configuration
217  * is installed).  The altsetting arrays can be accessed through these
218  * structures at any time, permitting comparison of configurations and
219  * providing support for the /proc/bus/usb/devices pseudo-file.
220  */
221 struct usb_interface_cache {
222 	unsigned num_altsetting;	/* number of alternate settings */
223 	struct kref ref;		/* reference counter */
224 
225 	/* variable-length array of alternate settings for this interface,
226 	 * stored in no particular order */
227 	struct usb_host_interface altsetting[0];
228 };
229 #define	ref_to_usb_interface_cache(r) \
230 		container_of(r, struct usb_interface_cache, ref)
231 #define	altsetting_to_usb_interface_cache(a) \
232 		container_of(a, struct usb_interface_cache, altsetting[0])
233 
234 /**
235  * struct usb_host_config - representation of a device's configuration
236  * @desc: the device's configuration descriptor.
237  * @string: pointer to the cached version of the iConfiguration string, if
238  *	present for this configuration.
239  * @intf_assoc: list of any interface association descriptors in this config
240  * @interface: array of pointers to usb_interface structures, one for each
241  *	interface in the configuration.  The number of interfaces is stored
242  *	in desc.bNumInterfaces.  These pointers are valid only while the
243  *	the configuration is active.
244  * @intf_cache: array of pointers to usb_interface_cache structures, one
245  *	for each interface in the configuration.  These structures exist
246  *	for the entire life of the device.
247  * @extra: pointer to buffer containing all extra descriptors associated
248  *	with this configuration (those preceding the first interface
249  *	descriptor).
250  * @extralen: length of the extra descriptors buffer.
251  *
252  * USB devices may have multiple configurations, but only one can be active
253  * at any time.  Each encapsulates a different operational environment;
254  * for example, a dual-speed device would have separate configurations for
255  * full-speed and high-speed operation.  The number of configurations
256  * available is stored in the device descriptor as bNumConfigurations.
257  *
258  * A configuration can contain multiple interfaces.  Each corresponds to
259  * a different function of the USB device, and all are available whenever
260  * the configuration is active.  The USB standard says that interfaces
261  * are supposed to be numbered from 0 to desc.bNumInterfaces-1, but a lot
262  * of devices get this wrong.  In addition, the interface array is not
263  * guaranteed to be sorted in numerical order.  Use usb_ifnum_to_if() to
264  * look up an interface entry based on its number.
265  *
266  * Device drivers should not attempt to activate configurations.  The choice
267  * of which configuration to install is a policy decision based on such
268  * considerations as available power, functionality provided, and the user's
269  * desires (expressed through userspace tools).  However, drivers can call
270  * usb_reset_configuration() to reinitialize the current configuration and
271  * all its interfaces.
272  */
273 struct usb_host_config {
274 	struct usb_config_descriptor	desc;
275 
276 	char *string;		/* iConfiguration string, if present */
277 
278 	/* List of any Interface Association Descriptors in this
279 	 * configuration. */
280 	struct usb_interface_assoc_descriptor *intf_assoc[USB_MAXIADS];
281 
282 	/* the interfaces associated with this configuration,
283 	 * stored in no particular order */
284 	struct usb_interface *interface[USB_MAXINTERFACES];
285 
286 	/* Interface information available even when this is not the
287 	 * active configuration */
288 	struct usb_interface_cache *intf_cache[USB_MAXINTERFACES];
289 
290 	unsigned char *extra;   /* Extra descriptors */
291 	int extralen;
292 };
293 
294 int __usb_get_extra_descriptor(char *buffer, unsigned size,
295 	unsigned char type, void **ptr);
296 #define usb_get_extra_descriptor(ifpoint, type, ptr) \
297 				__usb_get_extra_descriptor((ifpoint)->extra, \
298 				(ifpoint)->extralen, \
299 				type, (void **)ptr)
300 
301 /* ----------------------------------------------------------------------- */
302 
303 /* USB device number allocation bitmap */
304 struct usb_devmap {
305 	unsigned long devicemap[128 / (8*sizeof(unsigned long))];
306 };
307 
308 /*
309  * Allocated per bus (tree of devices) we have:
310  */
311 struct usb_bus {
312 	struct device *controller;	/* host/master side hardware */
313 	int busnum;			/* Bus number (in order of reg) */
314 	const char *bus_name;		/* stable id (PCI slot_name etc) */
315 	u8 uses_dma;			/* Does the host controller use DMA? */
316 	u8 uses_pio_for_control;	/*
317 					 * Does the host controller use PIO
318 					 * for control transfers?
319 					 */
320 	u8 otg_port;			/* 0, or number of OTG/HNP port */
321 	unsigned is_b_host:1;		/* true during some HNP roleswitches */
322 	unsigned b_hnp_enable:1;	/* OTG: did A-Host enable HNP? */
323 	unsigned sg_tablesize;		/* 0 or largest number of sg list entries */
324 
325 	int devnum_next;		/* Next open device number in
326 					 * round-robin allocation */
327 
328 	struct usb_devmap devmap;	/* device address allocation map */
329 	struct usb_device *root_hub;	/* Root hub */
330 	struct usb_bus *hs_companion;	/* Companion EHCI bus, if any */
331 	struct list_head bus_list;	/* list of busses */
332 
333 	int bandwidth_allocated;	/* on this bus: how much of the time
334 					 * reserved for periodic (intr/iso)
335 					 * requests is used, on average?
336 					 * Units: microseconds/frame.
337 					 * Limits: Full/low speed reserve 90%,
338 					 * while high speed reserves 80%.
339 					 */
340 	int bandwidth_int_reqs;		/* number of Interrupt requests */
341 	int bandwidth_isoc_reqs;	/* number of Isoc. requests */
342 
343 #ifdef CONFIG_USB_DEVICEFS
344 	struct dentry *usbfs_dentry;	/* usbfs dentry entry for the bus */
345 #endif
346 
347 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
348 	struct mon_bus *mon_bus;	/* non-null when associated */
349 	int monitored;			/* non-zero when monitored */
350 #endif
351 };
352 
353 /* ----------------------------------------------------------------------- */
354 
355 /* This is arbitrary.
356  * From USB 2.0 spec Table 11-13, offset 7, a hub can
357  * have up to 255 ports. The most yet reported is 10.
358  *
359  * Current Wireless USB host hardware (Intel i1480 for example) allows
360  * up to 22 devices to connect. Upcoming hardware might raise that
361  * limit. Because the arrays need to add a bit for hub status data, we
362  * do 31, so plus one evens out to four bytes.
363  */
364 #define USB_MAXCHILDREN		(31)
365 
366 struct usb_tt;
367 
368 /**
369  * struct usb_device - kernel's representation of a USB device
370  * @devnum: device number; address on a USB bus
371  * @devpath: device ID string for use in messages (e.g., /port/...)
372  * @route: tree topology hex string for use with xHCI
373  * @state: device state: configured, not attached, etc.
374  * @speed: device speed: high/full/low (or error)
375  * @tt: Transaction Translator info; used with low/full speed dev, highspeed hub
376  * @ttport: device port on that tt hub
377  * @toggle: one bit for each endpoint, with ([0] = IN, [1] = OUT) endpoints
378  * @parent: our hub, unless we're the root
379  * @bus: bus we're part of
380  * @ep0: endpoint 0 data (default control pipe)
381  * @dev: generic device interface
382  * @descriptor: USB device descriptor
383  * @config: all of the device's configs
384  * @actconfig: the active configuration
385  * @ep_in: array of IN endpoints
386  * @ep_out: array of OUT endpoints
387  * @rawdescriptors: raw descriptors for each config
388  * @bus_mA: Current available from the bus
389  * @portnum: parent port number (origin 1)
390  * @level: number of USB hub ancestors
391  * @can_submit: URBs may be submitted
392  * @persist_enabled:  USB_PERSIST enabled for this device
393  * @have_langid: whether string_langid is valid
394  * @authorized: policy has said we can use it;
395  *	(user space) policy determines if we authorize this device to be
396  *	used or not. By default, wired USB devices are authorized.
397  *	WUSB devices are not, until we authorize them from user space.
398  *	FIXME -- complete doc
399  * @authenticated: Crypto authentication passed
400  * @wusb: device is Wireless USB
401  * @string_langid: language ID for strings
402  * @product: iProduct string, if present (static)
403  * @manufacturer: iManufacturer string, if present (static)
404  * @serial: iSerialNumber string, if present (static)
405  * @filelist: usbfs files that are open to this device
406  * @usb_classdev: USB class device that was created for usbfs device
407  *	access from userspace
408  * @usbfs_dentry: usbfs dentry entry for the device
409  * @maxchild: number of ports if hub
410  * @children: child devices - USB devices that are attached to this hub
411  * @quirks: quirks of the whole device
412  * @urbnum: number of URBs submitted for the whole device
413  * @active_duration: total time device is not suspended
414  * @last_busy: time of last use
415  * @autosuspend_delay: in jiffies
416  * @connect_time: time device was first connected
417  * @do_remote_wakeup:  remote wakeup should be enabled
418  * @reset_resume: needs reset instead of resume
419  * @wusb_dev: if this is a Wireless USB device, link to the WUSB
420  *	specific data for the device.
421  * @slot_id: Slot ID assigned by xHCI
422  *
423  * Notes:
424  * Usbcore drivers should not set usbdev->state directly.  Instead use
425  * usb_set_device_state().
426  */
427 struct usb_device {
428 	int		devnum;
429 	char		devpath[16];
430 	u32		route;
431 	enum usb_device_state	state;
432 	enum usb_device_speed	speed;
433 
434 	struct usb_tt	*tt;
435 	int		ttport;
436 
437 	unsigned int toggle[2];
438 
439 	struct usb_device *parent;
440 	struct usb_bus *bus;
441 	struct usb_host_endpoint ep0;
442 
443 	struct device dev;
444 
445 	struct usb_device_descriptor descriptor;
446 	struct usb_host_config *config;
447 
448 	struct usb_host_config *actconfig;
449 	struct usb_host_endpoint *ep_in[16];
450 	struct usb_host_endpoint *ep_out[16];
451 
452 	char **rawdescriptors;
453 
454 	unsigned short bus_mA;
455 	u8 portnum;
456 	u8 level;
457 
458 	unsigned can_submit:1;
459 	unsigned persist_enabled:1;
460 	unsigned have_langid:1;
461 	unsigned authorized:1;
462 	unsigned authenticated:1;
463 	unsigned wusb:1;
464 	int string_langid;
465 
466 	/* static strings from the device */
467 	char *product;
468 	char *manufacturer;
469 	char *serial;
470 
471 	struct list_head filelist;
472 #ifdef CONFIG_USB_DEVICE_CLASS
473 	struct device *usb_classdev;
474 #endif
475 #ifdef CONFIG_USB_DEVICEFS
476 	struct dentry *usbfs_dentry;
477 #endif
478 
479 	int maxchild;
480 	struct usb_device *children[USB_MAXCHILDREN];
481 
482 	u32 quirks;
483 	atomic_t urbnum;
484 
485 	unsigned long active_duration;
486 
487 #ifdef CONFIG_PM
488 	unsigned long last_busy;
489 	int autosuspend_delay;
490 	unsigned long connect_time;
491 
492 	unsigned do_remote_wakeup:1;
493 	unsigned reset_resume:1;
494 #endif
495 	struct wusb_dev *wusb_dev;
496 	int slot_id;
497 };
498 #define	to_usb_device(d) container_of(d, struct usb_device, dev)
499 
500 static inline struct usb_device *interface_to_usbdev(struct usb_interface *intf)
501 {
502 	return to_usb_device(intf->dev.parent);
503 }
504 
505 extern struct usb_device *usb_get_dev(struct usb_device *dev);
506 extern void usb_put_dev(struct usb_device *dev);
507 
508 /* USB device locking */
509 #define usb_lock_device(udev)		device_lock(&(udev)->dev)
510 #define usb_unlock_device(udev)		device_unlock(&(udev)->dev)
511 #define usb_trylock_device(udev)	device_trylock(&(udev)->dev)
512 extern int usb_lock_device_for_reset(struct usb_device *udev,
513 				     const struct usb_interface *iface);
514 
515 /* USB port reset for device reinitialization */
516 extern int usb_reset_device(struct usb_device *dev);
517 extern void usb_queue_reset_device(struct usb_interface *dev);
518 
519 
520 /* USB autosuspend and autoresume */
521 #ifdef CONFIG_USB_SUSPEND
522 extern void usb_enable_autosuspend(struct usb_device *udev);
523 extern void usb_disable_autosuspend(struct usb_device *udev);
524 
525 extern int usb_autopm_get_interface(struct usb_interface *intf);
526 extern void usb_autopm_put_interface(struct usb_interface *intf);
527 extern int usb_autopm_get_interface_async(struct usb_interface *intf);
528 extern void usb_autopm_put_interface_async(struct usb_interface *intf);
529 extern void usb_autopm_get_interface_no_resume(struct usb_interface *intf);
530 extern void usb_autopm_put_interface_no_suspend(struct usb_interface *intf);
531 
532 static inline void usb_mark_last_busy(struct usb_device *udev)
533 {
534 	udev->last_busy = jiffies;
535 }
536 
537 #else
538 
539 static inline int usb_enable_autosuspend(struct usb_device *udev)
540 { return 0; }
541 static inline int usb_disable_autosuspend(struct usb_device *udev)
542 { return 0; }
543 
544 static inline int usb_autopm_get_interface(struct usb_interface *intf)
545 { return 0; }
546 static inline int usb_autopm_get_interface_async(struct usb_interface *intf)
547 { return 0; }
548 
549 static inline void usb_autopm_put_interface(struct usb_interface *intf)
550 { }
551 static inline void usb_autopm_put_interface_async(struct usb_interface *intf)
552 { }
553 static inline void usb_autopm_get_interface_no_resume(
554 		struct usb_interface *intf)
555 { }
556 static inline void usb_autopm_put_interface_no_suspend(
557 		struct usb_interface *intf)
558 { }
559 static inline void usb_mark_last_busy(struct usb_device *udev)
560 { }
561 #endif
562 
563 /*-------------------------------------------------------------------------*/
564 
565 /* for drivers using iso endpoints */
566 extern int usb_get_current_frame_number(struct usb_device *usb_dev);
567 
568 /* Sets up a group of bulk endpoints to support multiple stream IDs. */
569 extern int usb_alloc_streams(struct usb_interface *interface,
570 		struct usb_host_endpoint **eps, unsigned int num_eps,
571 		unsigned int num_streams, gfp_t mem_flags);
572 
573 /* Reverts a group of bulk endpoints back to not using stream IDs. */
574 extern void usb_free_streams(struct usb_interface *interface,
575 		struct usb_host_endpoint **eps, unsigned int num_eps,
576 		gfp_t mem_flags);
577 
578 /* used these for multi-interface device registration */
579 extern int usb_driver_claim_interface(struct usb_driver *driver,
580 			struct usb_interface *iface, void *priv);
581 
582 /**
583  * usb_interface_claimed - returns true iff an interface is claimed
584  * @iface: the interface being checked
585  *
586  * Returns true (nonzero) iff the interface is claimed, else false (zero).
587  * Callers must own the driver model's usb bus readlock.  So driver
588  * probe() entries don't need extra locking, but other call contexts
589  * may need to explicitly claim that lock.
590  *
591  */
592 static inline int usb_interface_claimed(struct usb_interface *iface)
593 {
594 	return (iface->dev.driver != NULL);
595 }
596 
597 extern void usb_driver_release_interface(struct usb_driver *driver,
598 			struct usb_interface *iface);
599 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
600 					 const struct usb_device_id *id);
601 extern int usb_match_one_id(struct usb_interface *interface,
602 			    const struct usb_device_id *id);
603 
604 extern struct usb_interface *usb_find_interface(struct usb_driver *drv,
605 		int minor);
606 extern struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
607 		unsigned ifnum);
608 extern struct usb_host_interface *usb_altnum_to_altsetting(
609 		const struct usb_interface *intf, unsigned int altnum);
610 extern struct usb_host_interface *usb_find_alt_setting(
611 		struct usb_host_config *config,
612 		unsigned int iface_num,
613 		unsigned int alt_num);
614 
615 
616 /**
617  * usb_make_path - returns stable device path in the usb tree
618  * @dev: the device whose path is being constructed
619  * @buf: where to put the string
620  * @size: how big is "buf"?
621  *
622  * Returns length of the string (> 0) or negative if size was too small.
623  *
624  * This identifier is intended to be "stable", reflecting physical paths in
625  * hardware such as physical bus addresses for host controllers or ports on
626  * USB hubs.  That makes it stay the same until systems are physically
627  * reconfigured, by re-cabling a tree of USB devices or by moving USB host
628  * controllers.  Adding and removing devices, including virtual root hubs
629  * in host controller driver modules, does not change these path identifers;
630  * neither does rebooting or re-enumerating.  These are more useful identifiers
631  * than changeable ("unstable") ones like bus numbers or device addresses.
632  *
633  * With a partial exception for devices connected to USB 2.0 root hubs, these
634  * identifiers are also predictable.  So long as the device tree isn't changed,
635  * plugging any USB device into a given hub port always gives it the same path.
636  * Because of the use of "companion" controllers, devices connected to ports on
637  * USB 2.0 root hubs (EHCI host controllers) will get one path ID if they are
638  * high speed, and a different one if they are full or low speed.
639  */
640 static inline int usb_make_path(struct usb_device *dev, char *buf, size_t size)
641 {
642 	int actual;
643 	actual = snprintf(buf, size, "usb-%s-%s", dev->bus->bus_name,
644 			  dev->devpath);
645 	return (actual >= (int)size) ? -1 : actual;
646 }
647 
648 /*-------------------------------------------------------------------------*/
649 
650 #define USB_DEVICE_ID_MATCH_DEVICE \
651 		(USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT)
652 #define USB_DEVICE_ID_MATCH_DEV_RANGE \
653 		(USB_DEVICE_ID_MATCH_DEV_LO | USB_DEVICE_ID_MATCH_DEV_HI)
654 #define USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION \
655 		(USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_RANGE)
656 #define USB_DEVICE_ID_MATCH_DEV_INFO \
657 		(USB_DEVICE_ID_MATCH_DEV_CLASS | \
658 		USB_DEVICE_ID_MATCH_DEV_SUBCLASS | \
659 		USB_DEVICE_ID_MATCH_DEV_PROTOCOL)
660 #define USB_DEVICE_ID_MATCH_INT_INFO \
661 		(USB_DEVICE_ID_MATCH_INT_CLASS | \
662 		USB_DEVICE_ID_MATCH_INT_SUBCLASS | \
663 		USB_DEVICE_ID_MATCH_INT_PROTOCOL)
664 
665 /**
666  * USB_DEVICE - macro used to describe a specific usb device
667  * @vend: the 16 bit USB Vendor ID
668  * @prod: the 16 bit USB Product ID
669  *
670  * This macro is used to create a struct usb_device_id that matches a
671  * specific device.
672  */
673 #define USB_DEVICE(vend, prod) \
674 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE, \
675 	.idVendor = (vend), \
676 	.idProduct = (prod)
677 /**
678  * USB_DEVICE_VER - describe a specific usb device with a version range
679  * @vend: the 16 bit USB Vendor ID
680  * @prod: the 16 bit USB Product ID
681  * @lo: the bcdDevice_lo value
682  * @hi: the bcdDevice_hi value
683  *
684  * This macro is used to create a struct usb_device_id that matches a
685  * specific device, with a version range.
686  */
687 #define USB_DEVICE_VER(vend, prod, lo, hi) \
688 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION, \
689 	.idVendor = (vend), \
690 	.idProduct = (prod), \
691 	.bcdDevice_lo = (lo), \
692 	.bcdDevice_hi = (hi)
693 
694 /**
695  * USB_DEVICE_INTERFACE_PROTOCOL - describe a usb device with a specific interface protocol
696  * @vend: the 16 bit USB Vendor ID
697  * @prod: the 16 bit USB Product ID
698  * @pr: bInterfaceProtocol value
699  *
700  * This macro is used to create a struct usb_device_id that matches a
701  * specific interface protocol of devices.
702  */
703 #define USB_DEVICE_INTERFACE_PROTOCOL(vend, prod, pr) \
704 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
705 		       USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
706 	.idVendor = (vend), \
707 	.idProduct = (prod), \
708 	.bInterfaceProtocol = (pr)
709 
710 /**
711  * USB_DEVICE_INFO - macro used to describe a class of usb devices
712  * @cl: bDeviceClass value
713  * @sc: bDeviceSubClass value
714  * @pr: bDeviceProtocol value
715  *
716  * This macro is used to create a struct usb_device_id that matches a
717  * specific class of devices.
718  */
719 #define USB_DEVICE_INFO(cl, sc, pr) \
720 	.match_flags = USB_DEVICE_ID_MATCH_DEV_INFO, \
721 	.bDeviceClass = (cl), \
722 	.bDeviceSubClass = (sc), \
723 	.bDeviceProtocol = (pr)
724 
725 /**
726  * USB_INTERFACE_INFO - macro used to describe a class of usb interfaces
727  * @cl: bInterfaceClass value
728  * @sc: bInterfaceSubClass value
729  * @pr: bInterfaceProtocol value
730  *
731  * This macro is used to create a struct usb_device_id that matches a
732  * specific class of interfaces.
733  */
734 #define USB_INTERFACE_INFO(cl, sc, pr) \
735 	.match_flags = USB_DEVICE_ID_MATCH_INT_INFO, \
736 	.bInterfaceClass = (cl), \
737 	.bInterfaceSubClass = (sc), \
738 	.bInterfaceProtocol = (pr)
739 
740 /**
741  * USB_DEVICE_AND_INTERFACE_INFO - describe a specific usb device with a class of usb interfaces
742  * @vend: the 16 bit USB Vendor ID
743  * @prod: the 16 bit USB Product ID
744  * @cl: bInterfaceClass value
745  * @sc: bInterfaceSubClass value
746  * @pr: bInterfaceProtocol value
747  *
748  * This macro is used to create a struct usb_device_id that matches a
749  * specific device with a specific class of interfaces.
750  *
751  * This is especially useful when explicitly matching devices that have
752  * vendor specific bDeviceClass values, but standards-compliant interfaces.
753  */
754 #define USB_DEVICE_AND_INTERFACE_INFO(vend, prod, cl, sc, pr) \
755 	.match_flags = USB_DEVICE_ID_MATCH_INT_INFO \
756 		| USB_DEVICE_ID_MATCH_DEVICE, \
757 	.idVendor = (vend), \
758 	.idProduct = (prod), \
759 	.bInterfaceClass = (cl), \
760 	.bInterfaceSubClass = (sc), \
761 	.bInterfaceProtocol = (pr)
762 
763 /* ----------------------------------------------------------------------- */
764 
765 /* Stuff for dynamic usb ids */
766 struct usb_dynids {
767 	spinlock_t lock;
768 	struct list_head list;
769 };
770 
771 struct usb_dynid {
772 	struct list_head node;
773 	struct usb_device_id id;
774 };
775 
776 extern ssize_t usb_store_new_id(struct usb_dynids *dynids,
777 				struct device_driver *driver,
778 				const char *buf, size_t count);
779 
780 /**
781  * struct usbdrv_wrap - wrapper for driver-model structure
782  * @driver: The driver-model core driver structure.
783  * @for_devices: Non-zero for device drivers, 0 for interface drivers.
784  */
785 struct usbdrv_wrap {
786 	struct device_driver driver;
787 	int for_devices;
788 };
789 
790 /**
791  * struct usb_driver - identifies USB interface driver to usbcore
792  * @name: The driver name should be unique among USB drivers,
793  *	and should normally be the same as the module name.
794  * @probe: Called to see if the driver is willing to manage a particular
795  *	interface on a device.  If it is, probe returns zero and uses
796  *	usb_set_intfdata() to associate driver-specific data with the
797  *	interface.  It may also use usb_set_interface() to specify the
798  *	appropriate altsetting.  If unwilling to manage the interface,
799  *	return -ENODEV, if genuine IO errors occured, an appropriate
800  *	negative errno value.
801  * @disconnect: Called when the interface is no longer accessible, usually
802  *	because its device has been (or is being) disconnected or the
803  *	driver module is being unloaded.
804  * @unlocked_ioctl: Used for drivers that want to talk to userspace through
805  *	the "usbfs" filesystem.  This lets devices provide ways to
806  *	expose information to user space regardless of where they
807  *	do (or don't) show up otherwise in the filesystem.
808  * @suspend: Called when the device is going to be suspended by the system.
809  * @resume: Called when the device is being resumed by the system.
810  * @reset_resume: Called when the suspended device has been reset instead
811  *	of being resumed.
812  * @pre_reset: Called by usb_reset_device() when the device
813  *	is about to be reset.
814  * @post_reset: Called by usb_reset_device() after the device
815  *	has been reset
816  * @id_table: USB drivers use ID table to support hotplugging.
817  *	Export this with MODULE_DEVICE_TABLE(usb,...).  This must be set
818  *	or your driver's probe function will never get called.
819  * @dynids: used internally to hold the list of dynamically added device
820  *	ids for this driver.
821  * @drvwrap: Driver-model core structure wrapper.
822  * @no_dynamic_id: if set to 1, the USB core will not allow dynamic ids to be
823  *	added to this driver by preventing the sysfs file from being created.
824  * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
825  *	for interfaces bound to this driver.
826  * @soft_unbind: if set to 1, the USB core will not kill URBs and disable
827  *	endpoints before calling the driver's disconnect method.
828  *
829  * USB interface drivers must provide a name, probe() and disconnect()
830  * methods, and an id_table.  Other driver fields are optional.
831  *
832  * The id_table is used in hotplugging.  It holds a set of descriptors,
833  * and specialized data may be associated with each entry.  That table
834  * is used by both user and kernel mode hotplugging support.
835  *
836  * The probe() and disconnect() methods are called in a context where
837  * they can sleep, but they should avoid abusing the privilege.  Most
838  * work to connect to a device should be done when the device is opened,
839  * and undone at the last close.  The disconnect code needs to address
840  * concurrency issues with respect to open() and close() methods, as
841  * well as forcing all pending I/O requests to complete (by unlinking
842  * them as necessary, and blocking until the unlinks complete).
843  */
844 struct usb_driver {
845 	const char *name;
846 
847 	int (*probe) (struct usb_interface *intf,
848 		      const struct usb_device_id *id);
849 
850 	void (*disconnect) (struct usb_interface *intf);
851 
852 	int (*unlocked_ioctl) (struct usb_interface *intf, unsigned int code,
853 			void *buf);
854 
855 	int (*suspend) (struct usb_interface *intf, pm_message_t message);
856 	int (*resume) (struct usb_interface *intf);
857 	int (*reset_resume)(struct usb_interface *intf);
858 
859 	int (*pre_reset)(struct usb_interface *intf);
860 	int (*post_reset)(struct usb_interface *intf);
861 
862 	const struct usb_device_id *id_table;
863 
864 	struct usb_dynids dynids;
865 	struct usbdrv_wrap drvwrap;
866 	unsigned int no_dynamic_id:1;
867 	unsigned int supports_autosuspend:1;
868 	unsigned int soft_unbind:1;
869 };
870 #define	to_usb_driver(d) container_of(d, struct usb_driver, drvwrap.driver)
871 
872 /**
873  * struct usb_device_driver - identifies USB device driver to usbcore
874  * @name: The driver name should be unique among USB drivers,
875  *	and should normally be the same as the module name.
876  * @probe: Called to see if the driver is willing to manage a particular
877  *	device.  If it is, probe returns zero and uses dev_set_drvdata()
878  *	to associate driver-specific data with the device.  If unwilling
879  *	to manage the device, return a negative errno value.
880  * @disconnect: Called when the device is no longer accessible, usually
881  *	because it has been (or is being) disconnected or the driver's
882  *	module is being unloaded.
883  * @suspend: Called when the device is going to be suspended by the system.
884  * @resume: Called when the device is being resumed by the system.
885  * @drvwrap: Driver-model core structure wrapper.
886  * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
887  *	for devices bound to this driver.
888  *
889  * USB drivers must provide all the fields listed above except drvwrap.
890  */
891 struct usb_device_driver {
892 	const char *name;
893 
894 	int (*probe) (struct usb_device *udev);
895 	void (*disconnect) (struct usb_device *udev);
896 
897 	int (*suspend) (struct usb_device *udev, pm_message_t message);
898 	int (*resume) (struct usb_device *udev, pm_message_t message);
899 	struct usbdrv_wrap drvwrap;
900 	unsigned int supports_autosuspend:1;
901 };
902 #define	to_usb_device_driver(d) container_of(d, struct usb_device_driver, \
903 		drvwrap.driver)
904 
905 extern struct bus_type usb_bus_type;
906 
907 /**
908  * struct usb_class_driver - identifies a USB driver that wants to use the USB major number
909  * @name: the usb class device name for this driver.  Will show up in sysfs.
910  * @devnode: Callback to provide a naming hint for a possible
911  *	device node to create.
912  * @fops: pointer to the struct file_operations of this driver.
913  * @minor_base: the start of the minor range for this driver.
914  *
915  * This structure is used for the usb_register_dev() and
916  * usb_unregister_dev() functions, to consolidate a number of the
917  * parameters used for them.
918  */
919 struct usb_class_driver {
920 	char *name;
921 	char *(*devnode)(struct device *dev, mode_t *mode);
922 	const struct file_operations *fops;
923 	int minor_base;
924 };
925 
926 /*
927  * use these in module_init()/module_exit()
928  * and don't forget MODULE_DEVICE_TABLE(usb, ...)
929  */
930 extern int usb_register_driver(struct usb_driver *, struct module *,
931 			       const char *);
932 static inline int usb_register(struct usb_driver *driver)
933 {
934 	return usb_register_driver(driver, THIS_MODULE, KBUILD_MODNAME);
935 }
936 extern void usb_deregister(struct usb_driver *);
937 
938 extern int usb_register_device_driver(struct usb_device_driver *,
939 			struct module *);
940 extern void usb_deregister_device_driver(struct usb_device_driver *);
941 
942 extern int usb_register_dev(struct usb_interface *intf,
943 			    struct usb_class_driver *class_driver);
944 extern void usb_deregister_dev(struct usb_interface *intf,
945 			       struct usb_class_driver *class_driver);
946 
947 extern int usb_disabled(void);
948 
949 /* ----------------------------------------------------------------------- */
950 
951 /*
952  * URB support, for asynchronous request completions
953  */
954 
955 /*
956  * urb->transfer_flags:
957  *
958  * Note: URB_DIR_IN/OUT is automatically set in usb_submit_urb().
959  */
960 #define URB_SHORT_NOT_OK	0x0001	/* report short reads as errors */
961 #define URB_ISO_ASAP		0x0002	/* iso-only, urb->start_frame
962 					 * ignored */
963 #define URB_NO_TRANSFER_DMA_MAP	0x0004	/* urb->transfer_dma valid on submit */
964 #define URB_NO_FSBR		0x0020	/* UHCI-specific */
965 #define URB_ZERO_PACKET		0x0040	/* Finish bulk OUT with short packet */
966 #define URB_NO_INTERRUPT	0x0080	/* HINT: no non-error interrupt
967 					 * needed */
968 #define URB_FREE_BUFFER		0x0100	/* Free transfer buffer with the URB */
969 
970 /* The following flags are used internally by usbcore and HCDs */
971 #define URB_DIR_IN		0x0200	/* Transfer from device to host */
972 #define URB_DIR_OUT		0
973 #define URB_DIR_MASK		URB_DIR_IN
974 
975 #define URB_DMA_MAP_SINGLE	0x00010000	/* Non-scatter-gather mapping */
976 #define URB_DMA_MAP_PAGE	0x00020000	/* HCD-unsupported S-G */
977 #define URB_DMA_MAP_SG		0x00040000	/* HCD-supported S-G */
978 #define URB_MAP_LOCAL		0x00080000	/* HCD-local-memory mapping */
979 #define URB_SETUP_MAP_SINGLE	0x00100000	/* Setup packet DMA mapped */
980 #define URB_SETUP_MAP_LOCAL	0x00200000	/* HCD-local setup packet */
981 #define URB_DMA_SG_COMBINED	0x00400000	/* S-G entries were combined */
982 
983 struct usb_iso_packet_descriptor {
984 	unsigned int offset;
985 	unsigned int length;		/* expected length */
986 	unsigned int actual_length;
987 	int status;
988 };
989 
990 struct urb;
991 
992 struct usb_anchor {
993 	struct list_head urb_list;
994 	wait_queue_head_t wait;
995 	spinlock_t lock;
996 	unsigned int poisoned:1;
997 };
998 
999 static inline void init_usb_anchor(struct usb_anchor *anchor)
1000 {
1001 	INIT_LIST_HEAD(&anchor->urb_list);
1002 	init_waitqueue_head(&anchor->wait);
1003 	spin_lock_init(&anchor->lock);
1004 }
1005 
1006 typedef void (*usb_complete_t)(struct urb *);
1007 
1008 /**
1009  * struct urb - USB Request Block
1010  * @urb_list: For use by current owner of the URB.
1011  * @anchor_list: membership in the list of an anchor
1012  * @anchor: to anchor URBs to a common mooring
1013  * @ep: Points to the endpoint's data structure.  Will eventually
1014  *	replace @pipe.
1015  * @pipe: Holds endpoint number, direction, type, and more.
1016  *	Create these values with the eight macros available;
1017  *	usb_{snd,rcv}TYPEpipe(dev,endpoint), where the TYPE is "ctrl"
1018  *	(control), "bulk", "int" (interrupt), or "iso" (isochronous).
1019  *	For example usb_sndbulkpipe() or usb_rcvintpipe().  Endpoint
1020  *	numbers range from zero to fifteen.  Note that "in" endpoint two
1021  *	is a different endpoint (and pipe) from "out" endpoint two.
1022  *	The current configuration controls the existence, type, and
1023  *	maximum packet size of any given endpoint.
1024  * @stream_id: the endpoint's stream ID for bulk streams
1025  * @dev: Identifies the USB device to perform the request.
1026  * @status: This is read in non-iso completion functions to get the
1027  *	status of the particular request.  ISO requests only use it
1028  *	to tell whether the URB was unlinked; detailed status for
1029  *	each frame is in the fields of the iso_frame-desc.
1030  * @transfer_flags: A variety of flags may be used to affect how URB
1031  *	submission, unlinking, or operation are handled.  Different
1032  *	kinds of URB can use different flags.
1033  * @transfer_buffer:  This identifies the buffer to (or from) which the I/O
1034  *	request will be performed unless URB_NO_TRANSFER_DMA_MAP is set
1035  *	(however, do not leave garbage in transfer_buffer even then).
1036  *	This buffer must be suitable for DMA; allocate it with
1037  *	kmalloc() or equivalent.  For transfers to "in" endpoints, contents
1038  *	of this buffer will be modified.  This buffer is used for the data
1039  *	stage of control transfers.
1040  * @transfer_dma: When transfer_flags includes URB_NO_TRANSFER_DMA_MAP,
1041  *	the device driver is saying that it provided this DMA address,
1042  *	which the host controller driver should use in preference to the
1043  *	transfer_buffer.
1044  * @sg: scatter gather buffer list
1045  * @num_sgs: number of entries in the sg list
1046  * @transfer_buffer_length: How big is transfer_buffer.  The transfer may
1047  *	be broken up into chunks according to the current maximum packet
1048  *	size for the endpoint, which is a function of the configuration
1049  *	and is encoded in the pipe.  When the length is zero, neither
1050  *	transfer_buffer nor transfer_dma is used.
1051  * @actual_length: This is read in non-iso completion functions, and
1052  *	it tells how many bytes (out of transfer_buffer_length) were
1053  *	transferred.  It will normally be the same as requested, unless
1054  *	either an error was reported or a short read was performed.
1055  *	The URB_SHORT_NOT_OK transfer flag may be used to make such
1056  *	short reads be reported as errors.
1057  * @setup_packet: Only used for control transfers, this points to eight bytes
1058  *	of setup data.  Control transfers always start by sending this data
1059  *	to the device.  Then transfer_buffer is read or written, if needed.
1060  * @setup_dma: DMA pointer for the setup packet.  The caller must not use
1061  *	this field; setup_packet must point to a valid buffer.
1062  * @start_frame: Returns the initial frame for isochronous transfers.
1063  * @number_of_packets: Lists the number of ISO transfer buffers.
1064  * @interval: Specifies the polling interval for interrupt or isochronous
1065  *	transfers.  The units are frames (milliseconds) for full and low
1066  *	speed devices, and microframes (1/8 millisecond) for highspeed
1067  *	and SuperSpeed devices.
1068  * @error_count: Returns the number of ISO transfers that reported errors.
1069  * @context: For use in completion functions.  This normally points to
1070  *	request-specific driver context.
1071  * @complete: Completion handler. This URB is passed as the parameter to the
1072  *	completion function.  The completion function may then do what
1073  *	it likes with the URB, including resubmitting or freeing it.
1074  * @iso_frame_desc: Used to provide arrays of ISO transfer buffers and to
1075  *	collect the transfer status for each buffer.
1076  *
1077  * This structure identifies USB transfer requests.  URBs must be allocated by
1078  * calling usb_alloc_urb() and freed with a call to usb_free_urb().
1079  * Initialization may be done using various usb_fill_*_urb() functions.  URBs
1080  * are submitted using usb_submit_urb(), and pending requests may be canceled
1081  * using usb_unlink_urb() or usb_kill_urb().
1082  *
1083  * Data Transfer Buffers:
1084  *
1085  * Normally drivers provide I/O buffers allocated with kmalloc() or otherwise
1086  * taken from the general page pool.  That is provided by transfer_buffer
1087  * (control requests also use setup_packet), and host controller drivers
1088  * perform a dma mapping (and unmapping) for each buffer transferred.  Those
1089  * mapping operations can be expensive on some platforms (perhaps using a dma
1090  * bounce buffer or talking to an IOMMU),
1091  * although they're cheap on commodity x86 and ppc hardware.
1092  *
1093  * Alternatively, drivers may pass the URB_NO_TRANSFER_DMA_MAP transfer flag,
1094  * which tells the host controller driver that no such mapping is needed for
1095  * the transfer_buffer since
1096  * the device driver is DMA-aware.  For example, a device driver might
1097  * allocate a DMA buffer with usb_alloc_coherent() or call usb_buffer_map().
1098  * When this transfer flag is provided, host controller drivers will
1099  * attempt to use the dma address found in the transfer_dma
1100  * field rather than determining a dma address themselves.
1101  *
1102  * Note that transfer_buffer must still be set if the controller
1103  * does not support DMA (as indicated by bus.uses_dma) and when talking
1104  * to root hub. If you have to trasfer between highmem zone and the device
1105  * on such controller, create a bounce buffer or bail out with an error.
1106  * If transfer_buffer cannot be set (is in highmem) and the controller is DMA
1107  * capable, assign NULL to it, so that usbmon knows not to use the value.
1108  * The setup_packet must always be set, so it cannot be located in highmem.
1109  *
1110  * Initialization:
1111  *
1112  * All URBs submitted must initialize the dev, pipe, transfer_flags (may be
1113  * zero), and complete fields.  All URBs must also initialize
1114  * transfer_buffer and transfer_buffer_length.  They may provide the
1115  * URB_SHORT_NOT_OK transfer flag, indicating that short reads are
1116  * to be treated as errors; that flag is invalid for write requests.
1117  *
1118  * Bulk URBs may
1119  * use the URB_ZERO_PACKET transfer flag, indicating that bulk OUT transfers
1120  * should always terminate with a short packet, even if it means adding an
1121  * extra zero length packet.
1122  *
1123  * Control URBs must provide a valid pointer in the setup_packet field.
1124  * Unlike the transfer_buffer, the setup_packet may not be mapped for DMA
1125  * beforehand.
1126  *
1127  * Interrupt URBs must provide an interval, saying how often (in milliseconds
1128  * or, for highspeed devices, 125 microsecond units)
1129  * to poll for transfers.  After the URB has been submitted, the interval
1130  * field reflects how the transfer was actually scheduled.
1131  * The polling interval may be more frequent than requested.
1132  * For example, some controllers have a maximum interval of 32 milliseconds,
1133  * while others support intervals of up to 1024 milliseconds.
1134  * Isochronous URBs also have transfer intervals.  (Note that for isochronous
1135  * endpoints, as well as high speed interrupt endpoints, the encoding of
1136  * the transfer interval in the endpoint descriptor is logarithmic.
1137  * Device drivers must convert that value to linear units themselves.)
1138  *
1139  * Isochronous URBs normally use the URB_ISO_ASAP transfer flag, telling
1140  * the host controller to schedule the transfer as soon as bandwidth
1141  * utilization allows, and then set start_frame to reflect the actual frame
1142  * selected during submission.  Otherwise drivers must specify the start_frame
1143  * and handle the case where the transfer can't begin then.  However, drivers
1144  * won't know how bandwidth is currently allocated, and while they can
1145  * find the current frame using usb_get_current_frame_number () they can't
1146  * know the range for that frame number.  (Ranges for frame counter values
1147  * are HC-specific, and can go from 256 to 65536 frames from "now".)
1148  *
1149  * Isochronous URBs have a different data transfer model, in part because
1150  * the quality of service is only "best effort".  Callers provide specially
1151  * allocated URBs, with number_of_packets worth of iso_frame_desc structures
1152  * at the end.  Each such packet is an individual ISO transfer.  Isochronous
1153  * URBs are normally queued, submitted by drivers to arrange that
1154  * transfers are at least double buffered, and then explicitly resubmitted
1155  * in completion handlers, so
1156  * that data (such as audio or video) streams at as constant a rate as the
1157  * host controller scheduler can support.
1158  *
1159  * Completion Callbacks:
1160  *
1161  * The completion callback is made in_interrupt(), and one of the first
1162  * things that a completion handler should do is check the status field.
1163  * The status field is provided for all URBs.  It is used to report
1164  * unlinked URBs, and status for all non-ISO transfers.  It should not
1165  * be examined before the URB is returned to the completion handler.
1166  *
1167  * The context field is normally used to link URBs back to the relevant
1168  * driver or request state.
1169  *
1170  * When the completion callback is invoked for non-isochronous URBs, the
1171  * actual_length field tells how many bytes were transferred.  This field
1172  * is updated even when the URB terminated with an error or was unlinked.
1173  *
1174  * ISO transfer status is reported in the status and actual_length fields
1175  * of the iso_frame_desc array, and the number of errors is reported in
1176  * error_count.  Completion callbacks for ISO transfers will normally
1177  * (re)submit URBs to ensure a constant transfer rate.
1178  *
1179  * Note that even fields marked "public" should not be touched by the driver
1180  * when the urb is owned by the hcd, that is, since the call to
1181  * usb_submit_urb() till the entry into the completion routine.
1182  */
1183 struct urb {
1184 	/* private: usb core and host controller only fields in the urb */
1185 	struct kref kref;		/* reference count of the URB */
1186 	void *hcpriv;			/* private data for host controller */
1187 	atomic_t use_count;		/* concurrent submissions counter */
1188 	atomic_t reject;		/* submissions will fail */
1189 	int unlinked;			/* unlink error code */
1190 
1191 	/* public: documented fields in the urb that can be used by drivers */
1192 	struct list_head urb_list;	/* list head for use by the urb's
1193 					 * current owner */
1194 	struct list_head anchor_list;	/* the URB may be anchored */
1195 	struct usb_anchor *anchor;
1196 	struct usb_device *dev;		/* (in) pointer to associated device */
1197 	struct usb_host_endpoint *ep;	/* (internal) pointer to endpoint */
1198 	unsigned int pipe;		/* (in) pipe information */
1199 	unsigned int stream_id;		/* (in) stream ID */
1200 	int status;			/* (return) non-ISO status */
1201 	unsigned int transfer_flags;	/* (in) URB_SHORT_NOT_OK | ...*/
1202 	void *transfer_buffer;		/* (in) associated data buffer */
1203 	dma_addr_t transfer_dma;	/* (in) dma addr for transfer_buffer */
1204 	struct scatterlist *sg;		/* (in) scatter gather buffer list */
1205 	int num_sgs;			/* (in) number of entries in the sg list */
1206 	u32 transfer_buffer_length;	/* (in) data buffer length */
1207 	u32 actual_length;		/* (return) actual transfer length */
1208 	unsigned char *setup_packet;	/* (in) setup packet (control only) */
1209 	dma_addr_t setup_dma;		/* (in) dma addr for setup_packet */
1210 	int start_frame;		/* (modify) start frame (ISO) */
1211 	int number_of_packets;		/* (in) number of ISO packets */
1212 	int interval;			/* (modify) transfer interval
1213 					 * (INT/ISO) */
1214 	int error_count;		/* (return) number of ISO errors */
1215 	void *context;			/* (in) context for completion */
1216 	usb_complete_t complete;	/* (in) completion routine */
1217 	struct usb_iso_packet_descriptor iso_frame_desc[0];
1218 					/* (in) ISO ONLY */
1219 };
1220 
1221 /* ----------------------------------------------------------------------- */
1222 
1223 /**
1224  * usb_fill_control_urb - initializes a control urb
1225  * @urb: pointer to the urb to initialize.
1226  * @dev: pointer to the struct usb_device for this urb.
1227  * @pipe: the endpoint pipe
1228  * @setup_packet: pointer to the setup_packet buffer
1229  * @transfer_buffer: pointer to the transfer buffer
1230  * @buffer_length: length of the transfer buffer
1231  * @complete_fn: pointer to the usb_complete_t function
1232  * @context: what to set the urb context to.
1233  *
1234  * Initializes a control urb with the proper information needed to submit
1235  * it to a device.
1236  */
1237 static inline void usb_fill_control_urb(struct urb *urb,
1238 					struct usb_device *dev,
1239 					unsigned int pipe,
1240 					unsigned char *setup_packet,
1241 					void *transfer_buffer,
1242 					int buffer_length,
1243 					usb_complete_t complete_fn,
1244 					void *context)
1245 {
1246 	urb->dev = dev;
1247 	urb->pipe = pipe;
1248 	urb->setup_packet = setup_packet;
1249 	urb->transfer_buffer = transfer_buffer;
1250 	urb->transfer_buffer_length = buffer_length;
1251 	urb->complete = complete_fn;
1252 	urb->context = context;
1253 }
1254 
1255 /**
1256  * usb_fill_bulk_urb - macro to help initialize a bulk urb
1257  * @urb: pointer to the urb to initialize.
1258  * @dev: pointer to the struct usb_device for this urb.
1259  * @pipe: the endpoint pipe
1260  * @transfer_buffer: pointer to the transfer buffer
1261  * @buffer_length: length of the transfer buffer
1262  * @complete_fn: pointer to the usb_complete_t function
1263  * @context: what to set the urb context to.
1264  *
1265  * Initializes a bulk urb with the proper information needed to submit it
1266  * to a device.
1267  */
1268 static inline void usb_fill_bulk_urb(struct urb *urb,
1269 				     struct usb_device *dev,
1270 				     unsigned int pipe,
1271 				     void *transfer_buffer,
1272 				     int buffer_length,
1273 				     usb_complete_t complete_fn,
1274 				     void *context)
1275 {
1276 	urb->dev = dev;
1277 	urb->pipe = pipe;
1278 	urb->transfer_buffer = transfer_buffer;
1279 	urb->transfer_buffer_length = buffer_length;
1280 	urb->complete = complete_fn;
1281 	urb->context = context;
1282 }
1283 
1284 /**
1285  * usb_fill_int_urb - macro to help initialize a interrupt urb
1286  * @urb: pointer to the urb to initialize.
1287  * @dev: pointer to the struct usb_device for this urb.
1288  * @pipe: the endpoint pipe
1289  * @transfer_buffer: pointer to the transfer buffer
1290  * @buffer_length: length of the transfer buffer
1291  * @complete_fn: pointer to the usb_complete_t function
1292  * @context: what to set the urb context to.
1293  * @interval: what to set the urb interval to, encoded like
1294  *	the endpoint descriptor's bInterval value.
1295  *
1296  * Initializes a interrupt urb with the proper information needed to submit
1297  * it to a device.
1298  *
1299  * Note that High Speed and SuperSpeed interrupt endpoints use a logarithmic
1300  * encoding of the endpoint interval, and express polling intervals in
1301  * microframes (eight per millisecond) rather than in frames (one per
1302  * millisecond).
1303  *
1304  * Wireless USB also uses the logarithmic encoding, but specifies it in units of
1305  * 128us instead of 125us.  For Wireless USB devices, the interval is passed
1306  * through to the host controller, rather than being translated into microframe
1307  * units.
1308  */
1309 static inline void usb_fill_int_urb(struct urb *urb,
1310 				    struct usb_device *dev,
1311 				    unsigned int pipe,
1312 				    void *transfer_buffer,
1313 				    int buffer_length,
1314 				    usb_complete_t complete_fn,
1315 				    void *context,
1316 				    int interval)
1317 {
1318 	urb->dev = dev;
1319 	urb->pipe = pipe;
1320 	urb->transfer_buffer = transfer_buffer;
1321 	urb->transfer_buffer_length = buffer_length;
1322 	urb->complete = complete_fn;
1323 	urb->context = context;
1324 	if (dev->speed == USB_SPEED_HIGH || dev->speed == USB_SPEED_SUPER)
1325 		urb->interval = 1 << (interval - 1);
1326 	else
1327 		urb->interval = interval;
1328 	urb->start_frame = -1;
1329 }
1330 
1331 extern void usb_init_urb(struct urb *urb);
1332 extern struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags);
1333 extern void usb_free_urb(struct urb *urb);
1334 #define usb_put_urb usb_free_urb
1335 extern struct urb *usb_get_urb(struct urb *urb);
1336 extern int usb_submit_urb(struct urb *urb, gfp_t mem_flags);
1337 extern int usb_unlink_urb(struct urb *urb);
1338 extern void usb_kill_urb(struct urb *urb);
1339 extern void usb_poison_urb(struct urb *urb);
1340 extern void usb_unpoison_urb(struct urb *urb);
1341 extern void usb_kill_anchored_urbs(struct usb_anchor *anchor);
1342 extern void usb_poison_anchored_urbs(struct usb_anchor *anchor);
1343 extern void usb_unpoison_anchored_urbs(struct usb_anchor *anchor);
1344 extern void usb_unlink_anchored_urbs(struct usb_anchor *anchor);
1345 extern void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor);
1346 extern void usb_unanchor_urb(struct urb *urb);
1347 extern int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor,
1348 					 unsigned int timeout);
1349 extern struct urb *usb_get_from_anchor(struct usb_anchor *anchor);
1350 extern void usb_scuttle_anchored_urbs(struct usb_anchor *anchor);
1351 extern int usb_anchor_empty(struct usb_anchor *anchor);
1352 
1353 /**
1354  * usb_urb_dir_in - check if an URB describes an IN transfer
1355  * @urb: URB to be checked
1356  *
1357  * Returns 1 if @urb describes an IN transfer (device-to-host),
1358  * otherwise 0.
1359  */
1360 static inline int usb_urb_dir_in(struct urb *urb)
1361 {
1362 	return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_IN;
1363 }
1364 
1365 /**
1366  * usb_urb_dir_out - check if an URB describes an OUT transfer
1367  * @urb: URB to be checked
1368  *
1369  * Returns 1 if @urb describes an OUT transfer (host-to-device),
1370  * otherwise 0.
1371  */
1372 static inline int usb_urb_dir_out(struct urb *urb)
1373 {
1374 	return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_OUT;
1375 }
1376 
1377 void *usb_alloc_coherent(struct usb_device *dev, size_t size,
1378 	gfp_t mem_flags, dma_addr_t *dma);
1379 void usb_free_coherent(struct usb_device *dev, size_t size,
1380 	void *addr, dma_addr_t dma);
1381 
1382 #if 0
1383 struct urb *usb_buffer_map(struct urb *urb);
1384 void usb_buffer_dmasync(struct urb *urb);
1385 void usb_buffer_unmap(struct urb *urb);
1386 #endif
1387 
1388 struct scatterlist;
1389 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
1390 		      struct scatterlist *sg, int nents);
1391 #if 0
1392 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
1393 			   struct scatterlist *sg, int n_hw_ents);
1394 #endif
1395 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
1396 			 struct scatterlist *sg, int n_hw_ents);
1397 
1398 /*-------------------------------------------------------------------*
1399  *                         SYNCHRONOUS CALL SUPPORT                  *
1400  *-------------------------------------------------------------------*/
1401 
1402 extern int usb_control_msg(struct usb_device *dev, unsigned int pipe,
1403 	__u8 request, __u8 requesttype, __u16 value, __u16 index,
1404 	void *data, __u16 size, int timeout);
1405 extern int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
1406 	void *data, int len, int *actual_length, int timeout);
1407 extern int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
1408 	void *data, int len, int *actual_length,
1409 	int timeout);
1410 
1411 /* wrappers around usb_control_msg() for the most common standard requests */
1412 extern int usb_get_descriptor(struct usb_device *dev, unsigned char desctype,
1413 	unsigned char descindex, void *buf, int size);
1414 extern int usb_get_status(struct usb_device *dev,
1415 	int type, int target, void *data);
1416 extern int usb_string(struct usb_device *dev, int index,
1417 	char *buf, size_t size);
1418 
1419 /* wrappers that also update important state inside usbcore */
1420 extern int usb_clear_halt(struct usb_device *dev, int pipe);
1421 extern int usb_reset_configuration(struct usb_device *dev);
1422 extern int usb_set_interface(struct usb_device *dev, int ifnum, int alternate);
1423 extern void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr);
1424 
1425 /* this request isn't really synchronous, but it belongs with the others */
1426 extern int usb_driver_set_configuration(struct usb_device *udev, int config);
1427 
1428 /*
1429  * timeouts, in milliseconds, used for sending/receiving control messages
1430  * they typically complete within a few frames (msec) after they're issued
1431  * USB identifies 5 second timeouts, maybe more in a few cases, and a few
1432  * slow devices (like some MGE Ellipse UPSes) actually push that limit.
1433  */
1434 #define USB_CTRL_GET_TIMEOUT	5000
1435 #define USB_CTRL_SET_TIMEOUT	5000
1436 
1437 
1438 /**
1439  * struct usb_sg_request - support for scatter/gather I/O
1440  * @status: zero indicates success, else negative errno
1441  * @bytes: counts bytes transferred.
1442  *
1443  * These requests are initialized using usb_sg_init(), and then are used
1444  * as request handles passed to usb_sg_wait() or usb_sg_cancel().  Most
1445  * members of the request object aren't for driver access.
1446  *
1447  * The status and bytecount values are valid only after usb_sg_wait()
1448  * returns.  If the status is zero, then the bytecount matches the total
1449  * from the request.
1450  *
1451  * After an error completion, drivers may need to clear a halt condition
1452  * on the endpoint.
1453  */
1454 struct usb_sg_request {
1455 	int			status;
1456 	size_t			bytes;
1457 
1458 	/* private:
1459 	 * members below are private to usbcore,
1460 	 * and are not provided for driver access!
1461 	 */
1462 	spinlock_t		lock;
1463 
1464 	struct usb_device	*dev;
1465 	int			pipe;
1466 
1467 	int			entries;
1468 	struct urb		**urbs;
1469 
1470 	int			count;
1471 	struct completion	complete;
1472 };
1473 
1474 int usb_sg_init(
1475 	struct usb_sg_request	*io,
1476 	struct usb_device	*dev,
1477 	unsigned		pipe,
1478 	unsigned		period,
1479 	struct scatterlist	*sg,
1480 	int			nents,
1481 	size_t			length,
1482 	gfp_t			mem_flags
1483 );
1484 void usb_sg_cancel(struct usb_sg_request *io);
1485 void usb_sg_wait(struct usb_sg_request *io);
1486 
1487 
1488 /* ----------------------------------------------------------------------- */
1489 
1490 /*
1491  * For various legacy reasons, Linux has a small cookie that's paired with
1492  * a struct usb_device to identify an endpoint queue.  Queue characteristics
1493  * are defined by the endpoint's descriptor.  This cookie is called a "pipe",
1494  * an unsigned int encoded as:
1495  *
1496  *  - direction:	bit 7		(0 = Host-to-Device [Out],
1497  *					 1 = Device-to-Host [In] ...
1498  *					like endpoint bEndpointAddress)
1499  *  - device address:	bits 8-14       ... bit positions known to uhci-hcd
1500  *  - endpoint:		bits 15-18      ... bit positions known to uhci-hcd
1501  *  - pipe type:	bits 30-31	(00 = isochronous, 01 = interrupt,
1502  *					 10 = control, 11 = bulk)
1503  *
1504  * Given the device address and endpoint descriptor, pipes are redundant.
1505  */
1506 
1507 /* NOTE:  these are not the standard USB_ENDPOINT_XFER_* values!! */
1508 /* (yet ... they're the values used by usbfs) */
1509 #define PIPE_ISOCHRONOUS		0
1510 #define PIPE_INTERRUPT			1
1511 #define PIPE_CONTROL			2
1512 #define PIPE_BULK			3
1513 
1514 #define usb_pipein(pipe)	((pipe) & USB_DIR_IN)
1515 #define usb_pipeout(pipe)	(!usb_pipein(pipe))
1516 
1517 #define usb_pipedevice(pipe)	(((pipe) >> 8) & 0x7f)
1518 #define usb_pipeendpoint(pipe)	(((pipe) >> 15) & 0xf)
1519 
1520 #define usb_pipetype(pipe)	(((pipe) >> 30) & 3)
1521 #define usb_pipeisoc(pipe)	(usb_pipetype((pipe)) == PIPE_ISOCHRONOUS)
1522 #define usb_pipeint(pipe)	(usb_pipetype((pipe)) == PIPE_INTERRUPT)
1523 #define usb_pipecontrol(pipe)	(usb_pipetype((pipe)) == PIPE_CONTROL)
1524 #define usb_pipebulk(pipe)	(usb_pipetype((pipe)) == PIPE_BULK)
1525 
1526 static inline unsigned int __create_pipe(struct usb_device *dev,
1527 		unsigned int endpoint)
1528 {
1529 	return (dev->devnum << 8) | (endpoint << 15);
1530 }
1531 
1532 /* Create various pipes... */
1533 #define usb_sndctrlpipe(dev, endpoint)	\
1534 	((PIPE_CONTROL << 30) | __create_pipe(dev, endpoint))
1535 #define usb_rcvctrlpipe(dev, endpoint)	\
1536 	((PIPE_CONTROL << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1537 #define usb_sndisocpipe(dev, endpoint)	\
1538 	((PIPE_ISOCHRONOUS << 30) | __create_pipe(dev, endpoint))
1539 #define usb_rcvisocpipe(dev, endpoint)	\
1540 	((PIPE_ISOCHRONOUS << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1541 #define usb_sndbulkpipe(dev, endpoint)	\
1542 	((PIPE_BULK << 30) | __create_pipe(dev, endpoint))
1543 #define usb_rcvbulkpipe(dev, endpoint)	\
1544 	((PIPE_BULK << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1545 #define usb_sndintpipe(dev, endpoint)	\
1546 	((PIPE_INTERRUPT << 30) | __create_pipe(dev, endpoint))
1547 #define usb_rcvintpipe(dev, endpoint)	\
1548 	((PIPE_INTERRUPT << 30) | __create_pipe(dev, endpoint) | USB_DIR_IN)
1549 
1550 static inline struct usb_host_endpoint *
1551 usb_pipe_endpoint(struct usb_device *dev, unsigned int pipe)
1552 {
1553 	struct usb_host_endpoint **eps;
1554 	eps = usb_pipein(pipe) ? dev->ep_in : dev->ep_out;
1555 	return eps[usb_pipeendpoint(pipe)];
1556 }
1557 
1558 /*-------------------------------------------------------------------------*/
1559 
1560 static inline __u16
1561 usb_maxpacket(struct usb_device *udev, int pipe, int is_out)
1562 {
1563 	struct usb_host_endpoint	*ep;
1564 	unsigned			epnum = usb_pipeendpoint(pipe);
1565 
1566 	if (is_out) {
1567 		WARN_ON(usb_pipein(pipe));
1568 		ep = udev->ep_out[epnum];
1569 	} else {
1570 		WARN_ON(usb_pipeout(pipe));
1571 		ep = udev->ep_in[epnum];
1572 	}
1573 	if (!ep)
1574 		return 0;
1575 
1576 	/* NOTE:  only 0x07ff bits are for packet size... */
1577 	return le16_to_cpu(ep->desc.wMaxPacketSize);
1578 }
1579 
1580 /* ----------------------------------------------------------------------- */
1581 
1582 /* Events from the usb core */
1583 #define USB_DEVICE_ADD		0x0001
1584 #define USB_DEVICE_REMOVE	0x0002
1585 #define USB_BUS_ADD		0x0003
1586 #define USB_BUS_REMOVE		0x0004
1587 extern void usb_register_notify(struct notifier_block *nb);
1588 extern void usb_unregister_notify(struct notifier_block *nb);
1589 
1590 #ifdef DEBUG
1591 #define dbg(format, arg...)						\
1592 	printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg)
1593 #else
1594 #define dbg(format, arg...)						\
1595 do {									\
1596 	if (0)								\
1597 		printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
1598 } while (0)
1599 #endif
1600 
1601 #define err(format, arg...)					\
1602 	printk(KERN_ERR KBUILD_MODNAME ": " format "\n", ##arg)
1603 
1604 /* debugfs stuff */
1605 extern struct dentry *usb_debug_root;
1606 
1607 #endif  /* __KERNEL__ */
1608 
1609 #endif
1610