USB: composite: usb_composite_unregister() no longer __exit
[linux-2.6.git] / drivers / usb / gadget / composite.c
1 /*
2  * composite.c - infrastructure for Composite USB Gadgets
3  *
4  * Copyright (C) 2006-2008 David Brownell
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20
21 /* #define VERBOSE_DEBUG */
22
23 #include <linux/kallsyms.h>
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/device.h>
27
28 #include <linux/usb/composite.h>
29
30
31 /*
32  * The code in this file is utility code, used to build a gadget driver
33  * from one or more "function" drivers, one or more "configuration"
34  * objects, and a "usb_composite_driver" by gluing them together along
35  * with the relevant device-wide data.
36  */
37
38 /* big enough to hold our biggest descriptor */
39 #define USB_BUFSIZ      512
40
41 static struct usb_composite_driver *composite;
42
43 /* Some systems will need runtime overrides for the  product identifers
44  * published in the device descriptor, either numbers or strings or both.
45  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
46  */
47
48 static ushort idVendor;
49 module_param(idVendor, ushort, 0);
50 MODULE_PARM_DESC(idVendor, "USB Vendor ID");
51
52 static ushort idProduct;
53 module_param(idProduct, ushort, 0);
54 MODULE_PARM_DESC(idProduct, "USB Product ID");
55
56 static ushort bcdDevice;
57 module_param(bcdDevice, ushort, 0);
58 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
59
60 static char *iManufacturer;
61 module_param(iManufacturer, charp, 0);
62 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
63
64 static char *iProduct;
65 module_param(iProduct, charp, 0);
66 MODULE_PARM_DESC(iProduct, "USB Product string");
67
68 static char *iSerialNumber;
69 module_param(iSerialNumber, charp, 0);
70 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
71
72 /*-------------------------------------------------------------------------*/
73
74 /**
75  * usb_add_function() - add a function to a configuration
76  * @config: the configuration
77  * @function: the function being added
78  * Context: single threaded during gadget setup
79  *
80  * After initialization, each configuration must have one or more
81  * functions added to it.  Adding a function involves calling its @bind()
82  * method to allocate resources such as interface and string identifiers
83  * and endpoints.
84  *
85  * This function returns the value of the function's bind(), which is
86  * zero for success else a negative errno value.
87  */
88 int __init usb_add_function(struct usb_configuration *config,
89                 struct usb_function *function)
90 {
91         int     value = -EINVAL;
92
93         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
94                         function->name, function,
95                         config->label, config);
96
97         if (!function->set_alt || !function->disable)
98                 goto done;
99
100         function->config = config;
101         list_add_tail(&function->list, &config->functions);
102
103         /* REVISIT *require* function->bind? */
104         if (function->bind) {
105                 value = function->bind(config, function);
106                 if (value < 0) {
107                         list_del(&function->list);
108                         function->config = NULL;
109                 }
110         } else
111                 value = 0;
112
113         /* We allow configurations that don't work at both speeds.
114          * If we run into a lowspeed Linux system, treat it the same
115          * as full speed ... it's the function drivers that will need
116          * to avoid bulk and ISO transfers.
117          */
118         if (!config->fullspeed && function->descriptors)
119                 config->fullspeed = true;
120         if (!config->highspeed && function->hs_descriptors)
121                 config->highspeed = true;
122
123 done:
124         if (value)
125                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
126                                 function->name, function, value);
127         return value;
128 }
129
130 /**
131  * usb_function_deactivate - prevent function and gadget enumeration
132  * @function: the function that isn't yet ready to respond
133  *
134  * Blocks response of the gadget driver to host enumeration by
135  * preventing the data line pullup from being activated.  This is
136  * normally called during @bind() processing to change from the
137  * initial "ready to respond" state, or when a required resource
138  * becomes available.
139  *
140  * For example, drivers that serve as a passthrough to a userspace
141  * daemon can block enumeration unless that daemon (such as an OBEX,
142  * MTP, or print server) is ready to handle host requests.
143  *
144  * Not all systems support software control of their USB peripheral
145  * data pullups.
146  *
147  * Returns zero on success, else negative errno.
148  */
149 int usb_function_deactivate(struct usb_function *function)
150 {
151         struct usb_composite_dev        *cdev = function->config->cdev;
152         unsigned long                   flags;
153         int                             status = 0;
154
155         spin_lock_irqsave(&cdev->lock, flags);
156
157         if (cdev->deactivations == 0)
158                 status = usb_gadget_disconnect(cdev->gadget);
159         if (status == 0)
160                 cdev->deactivations++;
161
162         spin_unlock_irqrestore(&cdev->lock, flags);
163         return status;
164 }
165
166 /**
167  * usb_function_activate - allow function and gadget enumeration
168  * @function: function on which usb_function_activate() was called
169  *
170  * Reverses effect of usb_function_deactivate().  If no more functions
171  * are delaying their activation, the gadget driver will respond to
172  * host enumeration procedures.
173  *
174  * Returns zero on success, else negative errno.
175  */
176 int usb_function_activate(struct usb_function *function)
177 {
178         struct usb_composite_dev        *cdev = function->config->cdev;
179         int                             status = 0;
180
181         spin_lock(&cdev->lock);
182
183         if (WARN_ON(cdev->deactivations == 0))
184                 status = -EINVAL;
185         else {
186                 cdev->deactivations--;
187                 if (cdev->deactivations == 0)
188                         status = usb_gadget_connect(cdev->gadget);
189         }
190
191         spin_unlock(&cdev->lock);
192         return status;
193 }
194
195 /**
196  * usb_interface_id() - allocate an unused interface ID
197  * @config: configuration associated with the interface
198  * @function: function handling the interface
199  * Context: single threaded during gadget setup
200  *
201  * usb_interface_id() is called from usb_function.bind() callbacks to
202  * allocate new interface IDs.  The function driver will then store that
203  * ID in interface, association, CDC union, and other descriptors.  It
204  * will also handle any control requests targetted at that interface,
205  * particularly changing its altsetting via set_alt().  There may
206  * also be class-specific or vendor-specific requests to handle.
207  *
208  * All interface identifier should be allocated using this routine, to
209  * ensure that for example different functions don't wrongly assign
210  * different meanings to the same identifier.  Note that since interface
211  * identifers are configuration-specific, functions used in more than
212  * one configuration (or more than once in a given configuration) need
213  * multiple versions of the relevant descriptors.
214  *
215  * Returns the interface ID which was allocated; or -ENODEV if no
216  * more interface IDs can be allocated.
217  */
218 int __init usb_interface_id(struct usb_configuration *config,
219                 struct usb_function *function)
220 {
221         unsigned id = config->next_interface_id;
222
223         if (id < MAX_CONFIG_INTERFACES) {
224                 config->interface[id] = function;
225                 config->next_interface_id = id + 1;
226                 return id;
227         }
228         return -ENODEV;
229 }
230
231 static int config_buf(struct usb_configuration *config,
232                 enum usb_device_speed speed, void *buf, u8 type)
233 {
234         struct usb_config_descriptor    *c = buf;
235         void                            *next = buf + USB_DT_CONFIG_SIZE;
236         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
237         struct usb_function             *f;
238         int                             status;
239
240         /* write the config descriptor */
241         c = buf;
242         c->bLength = USB_DT_CONFIG_SIZE;
243         c->bDescriptorType = type;
244         /* wTotalLength is written later */
245         c->bNumInterfaces = config->next_interface_id;
246         c->bConfigurationValue = config->bConfigurationValue;
247         c->iConfiguration = config->iConfiguration;
248         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
249         c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
250
251         /* There may be e.g. OTG descriptors */
252         if (config->descriptors) {
253                 status = usb_descriptor_fillbuf(next, len,
254                                 config->descriptors);
255                 if (status < 0)
256                         return status;
257                 len -= status;
258                 next += status;
259         }
260
261         /* add each function's descriptors */
262         list_for_each_entry(f, &config->functions, list) {
263                 struct usb_descriptor_header **descriptors;
264
265                 if (speed == USB_SPEED_HIGH)
266                         descriptors = f->hs_descriptors;
267                 else
268                         descriptors = f->descriptors;
269                 if (!descriptors)
270                         continue;
271                 status = usb_descriptor_fillbuf(next, len,
272                         (const struct usb_descriptor_header **) descriptors);
273                 if (status < 0)
274                         return status;
275                 len -= status;
276                 next += status;
277         }
278
279         len = next - buf;
280         c->wTotalLength = cpu_to_le16(len);
281         return len;
282 }
283
284 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
285 {
286         struct usb_gadget               *gadget = cdev->gadget;
287         struct usb_configuration        *c;
288         u8                              type = w_value >> 8;
289         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
290
291         if (gadget_is_dualspeed(gadget)) {
292                 int                     hs = 0;
293
294                 if (gadget->speed == USB_SPEED_HIGH)
295                         hs = 1;
296                 if (type == USB_DT_OTHER_SPEED_CONFIG)
297                         hs = !hs;
298                 if (hs)
299                         speed = USB_SPEED_HIGH;
300
301         }
302
303         /* This is a lookup by config *INDEX* */
304         w_value &= 0xff;
305         list_for_each_entry(c, &cdev->configs, list) {
306                 /* ignore configs that won't work at this speed */
307                 if (speed == USB_SPEED_HIGH) {
308                         if (!c->highspeed)
309                                 continue;
310                 } else {
311                         if (!c->fullspeed)
312                                 continue;
313                 }
314                 if (w_value == 0)
315                         return config_buf(c, speed, cdev->req->buf, type);
316                 w_value--;
317         }
318         return -EINVAL;
319 }
320
321 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
322 {
323         struct usb_gadget               *gadget = cdev->gadget;
324         struct usb_configuration        *c;
325         unsigned                        count = 0;
326         int                             hs = 0;
327
328         if (gadget_is_dualspeed(gadget)) {
329                 if (gadget->speed == USB_SPEED_HIGH)
330                         hs = 1;
331                 if (type == USB_DT_DEVICE_QUALIFIER)
332                         hs = !hs;
333         }
334         list_for_each_entry(c, &cdev->configs, list) {
335                 /* ignore configs that won't work at this speed */
336                 if (hs) {
337                         if (!c->highspeed)
338                                 continue;
339                 } else {
340                         if (!c->fullspeed)
341                                 continue;
342                 }
343                 count++;
344         }
345         return count;
346 }
347
348 static void device_qual(struct usb_composite_dev *cdev)
349 {
350         struct usb_qualifier_descriptor *qual = cdev->req->buf;
351
352         qual->bLength = sizeof(*qual);
353         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
354         /* POLICY: same bcdUSB and device type info at both speeds */
355         qual->bcdUSB = cdev->desc.bcdUSB;
356         qual->bDeviceClass = cdev->desc.bDeviceClass;
357         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
358         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
359         /* ASSUME same EP0 fifo size at both speeds */
360         qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
361         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
362         qual->bRESERVED = 0;
363 }
364
365 /*-------------------------------------------------------------------------*/
366
367 static void reset_config(struct usb_composite_dev *cdev)
368 {
369         struct usb_function             *f;
370
371         DBG(cdev, "reset config\n");
372
373         list_for_each_entry(f, &cdev->config->functions, list) {
374                 if (f->disable)
375                         f->disable(f);
376
377                 bitmap_zero(f->endpoints, 32);
378         }
379         cdev->config = NULL;
380 }
381
382 static int set_config(struct usb_composite_dev *cdev,
383                 const struct usb_ctrlrequest *ctrl, unsigned number)
384 {
385         struct usb_gadget       *gadget = cdev->gadget;
386         struct usb_configuration *c = NULL;
387         int                     result = -EINVAL;
388         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
389         int                     tmp;
390
391         if (cdev->config)
392                 reset_config(cdev);
393
394         if (number) {
395                 list_for_each_entry(c, &cdev->configs, list) {
396                         if (c->bConfigurationValue == number) {
397                                 result = 0;
398                                 break;
399                         }
400                 }
401                 if (result < 0)
402                         goto done;
403         } else
404                 result = 0;
405
406         INFO(cdev, "%s speed config #%d: %s\n",
407                 ({ char *speed;
408                 switch (gadget->speed) {
409                 case USB_SPEED_LOW:     speed = "low"; break;
410                 case USB_SPEED_FULL:    speed = "full"; break;
411                 case USB_SPEED_HIGH:    speed = "high"; break;
412                 default:                speed = "?"; break;
413                 } ; speed; }), number, c ? c->label : "unconfigured");
414
415         if (!c)
416                 goto done;
417
418         cdev->config = c;
419
420         /* Initialize all interfaces by setting them to altsetting zero. */
421         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
422                 struct usb_function     *f = c->interface[tmp];
423                 struct usb_descriptor_header **descriptors;
424
425                 if (!f)
426                         break;
427
428                 /*
429                  * Record which endpoints are used by the function. This is used
430                  * to dispatch control requests targeted at that endpoint to the
431                  * function's setup callback instead of the current
432                  * configuration's setup callback.
433                  */
434                 if (gadget->speed == USB_SPEED_HIGH)
435                         descriptors = f->hs_descriptors;
436                 else
437                         descriptors = f->descriptors;
438
439                 for (; *descriptors; ++descriptors) {
440                         struct usb_endpoint_descriptor *ep;
441                         int addr;
442
443                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
444                                 continue;
445
446                         ep = (struct usb_endpoint_descriptor *)*descriptors;
447                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
448                              |  (ep->bEndpointAddress & 0x0f);
449                         set_bit(addr, f->endpoints);
450                 }
451
452                 result = f->set_alt(f, tmp, 0);
453                 if (result < 0) {
454                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
455                                         tmp, f->name, f, result);
456
457                         reset_config(cdev);
458                         goto done;
459                 }
460         }
461
462         /* when we return, be sure our power usage is valid */
463         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
464 done:
465         usb_gadget_vbus_draw(gadget, power);
466         return result;
467 }
468
469 /**
470  * usb_add_config() - add a configuration to a device.
471  * @cdev: wraps the USB gadget
472  * @config: the configuration, with bConfigurationValue assigned
473  * Context: single threaded during gadget setup
474  *
475  * One of the main tasks of a composite driver's bind() routine is to
476  * add each of the configurations it supports, using this routine.
477  *
478  * This function returns the value of the configuration's bind(), which
479  * is zero for success else a negative errno value.  Binding configurations
480  * assigns global resources including string IDs, and per-configuration
481  * resources such as interface IDs and endpoints.
482  */
483 int __init usb_add_config(struct usb_composite_dev *cdev,
484                 struct usb_configuration *config)
485 {
486         int                             status = -EINVAL;
487         struct usb_configuration        *c;
488
489         DBG(cdev, "adding config #%u '%s'/%p\n",
490                         config->bConfigurationValue,
491                         config->label, config);
492
493         if (!config->bConfigurationValue || !config->bind)
494                 goto done;
495
496         /* Prevent duplicate configuration identifiers */
497         list_for_each_entry(c, &cdev->configs, list) {
498                 if (c->bConfigurationValue == config->bConfigurationValue) {
499                         status = -EBUSY;
500                         goto done;
501                 }
502         }
503
504         config->cdev = cdev;
505         list_add_tail(&config->list, &cdev->configs);
506
507         INIT_LIST_HEAD(&config->functions);
508         config->next_interface_id = 0;
509
510         status = config->bind(config);
511         if (status < 0) {
512                 list_del(&config->list);
513                 config->cdev = NULL;
514         } else {
515                 unsigned        i;
516
517                 DBG(cdev, "cfg %d/%p speeds:%s%s\n",
518                         config->bConfigurationValue, config,
519                         config->highspeed ? " high" : "",
520                         config->fullspeed
521                                 ? (gadget_is_dualspeed(cdev->gadget)
522                                         ? " full"
523                                         : " full/low")
524                                 : "");
525
526                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
527                         struct usb_function     *f = config->interface[i];
528
529                         if (!f)
530                                 continue;
531                         DBG(cdev, "  interface %d = %s/%p\n",
532                                 i, f->name, f);
533                 }
534         }
535
536         /* set_alt(), or next config->bind(), sets up
537          * ep->driver_data as needed.
538          */
539         usb_ep_autoconfig_reset(cdev->gadget);
540
541 done:
542         if (status)
543                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
544                                 config->bConfigurationValue, status);
545         return status;
546 }
547
548 /*-------------------------------------------------------------------------*/
549
550 /* We support strings in multiple languages ... string descriptor zero
551  * says which languages are supported.  The typical case will be that
552  * only one language (probably English) is used, with I18N handled on
553  * the host side.
554  */
555
556 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
557 {
558         const struct usb_gadget_strings *s;
559         u16                             language;
560         __le16                          *tmp;
561
562         while (*sp) {
563                 s = *sp;
564                 language = cpu_to_le16(s->language);
565                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
566                         if (*tmp == language)
567                                 goto repeat;
568                 }
569                 *tmp++ = language;
570 repeat:
571                 sp++;
572         }
573 }
574
575 static int lookup_string(
576         struct usb_gadget_strings       **sp,
577         void                            *buf,
578         u16                             language,
579         int                             id
580 )
581 {
582         struct usb_gadget_strings       *s;
583         int                             value;
584
585         while (*sp) {
586                 s = *sp++;
587                 if (s->language != language)
588                         continue;
589                 value = usb_gadget_get_string(s, id, buf);
590                 if (value > 0)
591                         return value;
592         }
593         return -EINVAL;
594 }
595
596 static int get_string(struct usb_composite_dev *cdev,
597                 void *buf, u16 language, int id)
598 {
599         struct usb_configuration        *c;
600         struct usb_function             *f;
601         int                             len;
602
603         /* Yes, not only is USB's I18N support probably more than most
604          * folk will ever care about ... also, it's all supported here.
605          * (Except for UTF8 support for Unicode's "Astral Planes".)
606          */
607
608         /* 0 == report all available language codes */
609         if (id == 0) {
610                 struct usb_string_descriptor    *s = buf;
611                 struct usb_gadget_strings       **sp;
612
613                 memset(s, 0, 256);
614                 s->bDescriptorType = USB_DT_STRING;
615
616                 sp = composite->strings;
617                 if (sp)
618                         collect_langs(sp, s->wData);
619
620                 list_for_each_entry(c, &cdev->configs, list) {
621                         sp = c->strings;
622                         if (sp)
623                                 collect_langs(sp, s->wData);
624
625                         list_for_each_entry(f, &c->functions, list) {
626                                 sp = f->strings;
627                                 if (sp)
628                                         collect_langs(sp, s->wData);
629                         }
630                 }
631
632                 for (len = 0; len <= 126 && s->wData[len]; len++)
633                         continue;
634                 if (!len)
635                         return -EINVAL;
636
637                 s->bLength = 2 * (len + 1);
638                 return s->bLength;
639         }
640
641         /* Otherwise, look up and return a specified string.  String IDs
642          * are device-scoped, so we look up each string table we're told
643          * about.  These lookups are infrequent; simpler-is-better here.
644          */
645         if (composite->strings) {
646                 len = lookup_string(composite->strings, buf, language, id);
647                 if (len > 0)
648                         return len;
649         }
650         list_for_each_entry(c, &cdev->configs, list) {
651                 if (c->strings) {
652                         len = lookup_string(c->strings, buf, language, id);
653                         if (len > 0)
654                                 return len;
655                 }
656                 list_for_each_entry(f, &c->functions, list) {
657                         if (!f->strings)
658                                 continue;
659                         len = lookup_string(f->strings, buf, language, id);
660                         if (len > 0)
661                                 return len;
662                 }
663         }
664         return -EINVAL;
665 }
666
667 /**
668  * usb_string_id() - allocate an unused string ID
669  * @cdev: the device whose string descriptor IDs are being allocated
670  * Context: single threaded during gadget setup
671  *
672  * @usb_string_id() is called from bind() callbacks to allocate
673  * string IDs.  Drivers for functions, configurations, or gadgets will
674  * then store that ID in the appropriate descriptors and string table.
675  *
676  * All string identifier should be allocated using this routine, to
677  * ensure that for example different functions don't wrongly assign
678  * different meanings to the same identifier.
679  */
680 int __init usb_string_id(struct usb_composite_dev *cdev)
681 {
682         if (cdev->next_string_id < 254) {
683                 /* string id 0 is reserved */
684                 cdev->next_string_id++;
685                 return cdev->next_string_id;
686         }
687         return -ENODEV;
688 }
689
690 /*-------------------------------------------------------------------------*/
691
692 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
693 {
694         if (req->status || req->actual != req->length)
695                 DBG((struct usb_composite_dev *) ep->driver_data,
696                                 "setup complete --> %d, %d/%d\n",
697                                 req->status, req->actual, req->length);
698 }
699
700 /*
701  * The setup() callback implements all the ep0 functionality that's
702  * not handled lower down, in hardware or the hardware driver(like
703  * device and endpoint feature flags, and their status).  It's all
704  * housekeeping for the gadget function we're implementing.  Most of
705  * the work is in config and function specific setup.
706  */
707 static int
708 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
709 {
710         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
711         struct usb_request              *req = cdev->req;
712         int                             value = -EOPNOTSUPP;
713         u16                             w_index = le16_to_cpu(ctrl->wIndex);
714         u8                              intf = w_index & 0xFF;
715         u16                             w_value = le16_to_cpu(ctrl->wValue);
716         u16                             w_length = le16_to_cpu(ctrl->wLength);
717         struct usb_function             *f = NULL;
718         u8                              endp;
719
720         /* partial re-init of the response message; the function or the
721          * gadget might need to intercept e.g. a control-OUT completion
722          * when we delegate to it.
723          */
724         req->zero = 0;
725         req->complete = composite_setup_complete;
726         req->length = USB_BUFSIZ;
727         gadget->ep0->driver_data = cdev;
728
729         switch (ctrl->bRequest) {
730
731         /* we handle all standard USB descriptors */
732         case USB_REQ_GET_DESCRIPTOR:
733                 if (ctrl->bRequestType != USB_DIR_IN)
734                         goto unknown;
735                 switch (w_value >> 8) {
736
737                 case USB_DT_DEVICE:
738                         cdev->desc.bNumConfigurations =
739                                 count_configs(cdev, USB_DT_DEVICE);
740                         value = min(w_length, (u16) sizeof cdev->desc);
741                         memcpy(req->buf, &cdev->desc, value);
742                         break;
743                 case USB_DT_DEVICE_QUALIFIER:
744                         if (!gadget_is_dualspeed(gadget))
745                                 break;
746                         device_qual(cdev);
747                         value = min_t(int, w_length,
748                                 sizeof(struct usb_qualifier_descriptor));
749                         break;
750                 case USB_DT_OTHER_SPEED_CONFIG:
751                         if (!gadget_is_dualspeed(gadget))
752                                 break;
753                         /* FALLTHROUGH */
754                 case USB_DT_CONFIG:
755                         value = config_desc(cdev, w_value);
756                         if (value >= 0)
757                                 value = min(w_length, (u16) value);
758                         break;
759                 case USB_DT_STRING:
760                         value = get_string(cdev, req->buf,
761                                         w_index, w_value & 0xff);
762                         if (value >= 0)
763                                 value = min(w_length, (u16) value);
764                         break;
765                 }
766                 break;
767
768         /* any number of configs can work */
769         case USB_REQ_SET_CONFIGURATION:
770                 if (ctrl->bRequestType != 0)
771                         goto unknown;
772                 if (gadget_is_otg(gadget)) {
773                         if (gadget->a_hnp_support)
774                                 DBG(cdev, "HNP available\n");
775                         else if (gadget->a_alt_hnp_support)
776                                 DBG(cdev, "HNP on another port\n");
777                         else
778                                 VDBG(cdev, "HNP inactive\n");
779                 }
780                 spin_lock(&cdev->lock);
781                 value = set_config(cdev, ctrl, w_value);
782                 spin_unlock(&cdev->lock);
783                 break;
784         case USB_REQ_GET_CONFIGURATION:
785                 if (ctrl->bRequestType != USB_DIR_IN)
786                         goto unknown;
787                 if (cdev->config)
788                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
789                 else
790                         *(u8 *)req->buf = 0;
791                 value = min(w_length, (u16) 1);
792                 break;
793
794         /* function drivers must handle get/set altsetting; if there's
795          * no get() method, we know only altsetting zero works.
796          */
797         case USB_REQ_SET_INTERFACE:
798                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
799                         goto unknown;
800                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
801                         break;
802                 f = cdev->config->interface[intf];
803                 if (!f)
804                         break;
805                 if (w_value && !f->set_alt)
806                         break;
807                 value = f->set_alt(f, w_index, w_value);
808                 break;
809         case USB_REQ_GET_INTERFACE:
810                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
811                         goto unknown;
812                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
813                         break;
814                 f = cdev->config->interface[intf];
815                 if (!f)
816                         break;
817                 /* lots of interfaces only need altsetting zero... */
818                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
819                 if (value < 0)
820                         break;
821                 *((u8 *)req->buf) = value;
822                 value = min(w_length, (u16) 1);
823                 break;
824         default:
825 unknown:
826                 VDBG(cdev,
827                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
828                         ctrl->bRequestType, ctrl->bRequest,
829                         w_value, w_index, w_length);
830
831                 /* functions always handle their interfaces and endpoints...
832                  * punt other recipients (other, WUSB, ...) to the current
833                  * configuration code.
834                  *
835                  * REVISIT it could make sense to let the composite device
836                  * take such requests too, if that's ever needed:  to work
837                  * in config 0, etc.
838                  */
839                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
840                 case USB_RECIP_INTERFACE:
841                         f = cdev->config->interface[intf];
842                         break;
843
844                 case USB_RECIP_ENDPOINT:
845                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
846                         list_for_each_entry(f, &cdev->config->functions, list) {
847                                 if (test_bit(endp, f->endpoints))
848                                         break;
849                         }
850                         if (&f->list == &cdev->config->functions)
851                                 f = NULL;
852                         break;
853                 }
854
855                 if (f && f->setup)
856                         value = f->setup(f, ctrl);
857                 else {
858                         struct usb_configuration        *c;
859
860                         c = cdev->config;
861                         if (c && c->setup)
862                                 value = c->setup(c, ctrl);
863                 }
864
865                 goto done;
866         }
867
868         /* respond with data transfer before status phase? */
869         if (value >= 0) {
870                 req->length = value;
871                 req->zero = value < w_length;
872                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
873                 if (value < 0) {
874                         DBG(cdev, "ep_queue --> %d\n", value);
875                         req->status = 0;
876                         composite_setup_complete(gadget->ep0, req);
877                 }
878         }
879
880 done:
881         /* device either stalls (value < 0) or reports success */
882         return value;
883 }
884
885 static void composite_disconnect(struct usb_gadget *gadget)
886 {
887         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
888         unsigned long                   flags;
889
890         /* REVISIT:  should we have config and device level
891          * disconnect callbacks?
892          */
893         spin_lock_irqsave(&cdev->lock, flags);
894         if (cdev->config)
895                 reset_config(cdev);
896         spin_unlock_irqrestore(&cdev->lock, flags);
897 }
898
899 /*-------------------------------------------------------------------------*/
900
901 static void /* __init_or_exit */
902 composite_unbind(struct usb_gadget *gadget)
903 {
904         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
905
906         /* composite_disconnect() must already have been called
907          * by the underlying peripheral controller driver!
908          * so there's no i/o concurrency that could affect the
909          * state protected by cdev->lock.
910          */
911         WARN_ON(cdev->config);
912
913         while (!list_empty(&cdev->configs)) {
914                 struct usb_configuration        *c;
915
916                 c = list_first_entry(&cdev->configs,
917                                 struct usb_configuration, list);
918                 while (!list_empty(&c->functions)) {
919                         struct usb_function             *f;
920
921                         f = list_first_entry(&c->functions,
922                                         struct usb_function, list);
923                         list_del(&f->list);
924                         if (f->unbind) {
925                                 DBG(cdev, "unbind function '%s'/%p\n",
926                                                 f->name, f);
927                                 f->unbind(c, f);
928                                 /* may free memory for "f" */
929                         }
930                 }
931                 list_del(&c->list);
932                 if (c->unbind) {
933                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
934                         c->unbind(c);
935                         /* may free memory for "c" */
936                 }
937         }
938         if (composite->unbind)
939                 composite->unbind(cdev);
940
941         if (cdev->req) {
942                 kfree(cdev->req->buf);
943                 usb_ep_free_request(gadget->ep0, cdev->req);
944         }
945         kfree(cdev);
946         set_gadget_data(gadget, NULL);
947         composite = NULL;
948 }
949
950 static void __init
951 string_override_one(struct usb_gadget_strings *tab, u8 id, const char *s)
952 {
953         struct usb_string               *str = tab->strings;
954
955         for (str = tab->strings; str->s; str++) {
956                 if (str->id == id) {
957                         str->s = s;
958                         return;
959                 }
960         }
961 }
962
963 static void __init
964 string_override(struct usb_gadget_strings **tab, u8 id, const char *s)
965 {
966         while (*tab) {
967                 string_override_one(*tab, id, s);
968                 tab++;
969         }
970 }
971
972 static int __init composite_bind(struct usb_gadget *gadget)
973 {
974         struct usb_composite_dev        *cdev;
975         int                             status = -ENOMEM;
976
977         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
978         if (!cdev)
979                 return status;
980
981         spin_lock_init(&cdev->lock);
982         cdev->gadget = gadget;
983         set_gadget_data(gadget, cdev);
984         INIT_LIST_HEAD(&cdev->configs);
985
986         /* preallocate control response and buffer */
987         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
988         if (!cdev->req)
989                 goto fail;
990         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
991         if (!cdev->req->buf)
992                 goto fail;
993         cdev->req->complete = composite_setup_complete;
994         gadget->ep0->driver_data = cdev;
995
996         cdev->bufsiz = USB_BUFSIZ;
997         cdev->driver = composite;
998
999         usb_gadget_set_selfpowered(gadget);
1000
1001         /* interface and string IDs start at zero via kzalloc.
1002          * we force endpoints to start unassigned; few controller
1003          * drivers will zero ep->driver_data.
1004          */
1005         usb_ep_autoconfig_reset(cdev->gadget);
1006
1007         /* composite gadget needs to assign strings for whole device (like
1008          * serial number), register function drivers, potentially update
1009          * power state and consumption, etc
1010          */
1011         status = composite->bind(cdev);
1012         if (status < 0)
1013                 goto fail;
1014
1015         cdev->desc = *composite->dev;
1016         cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
1017
1018         /* standardized runtime overrides for device ID data */
1019         if (idVendor)
1020                 cdev->desc.idVendor = cpu_to_le16(idVendor);
1021         if (idProduct)
1022                 cdev->desc.idProduct = cpu_to_le16(idProduct);
1023         if (bcdDevice)
1024                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1025
1026         /* strings can't be assigned before bind() allocates the
1027          * releavnt identifiers
1028          */
1029         if (cdev->desc.iManufacturer && iManufacturer)
1030                 string_override(composite->strings,
1031                         cdev->desc.iManufacturer, iManufacturer);
1032         if (cdev->desc.iProduct && iProduct)
1033                 string_override(composite->strings,
1034                         cdev->desc.iProduct, iProduct);
1035         if (cdev->desc.iSerialNumber && iSerialNumber)
1036                 string_override(composite->strings,
1037                         cdev->desc.iSerialNumber, iSerialNumber);
1038
1039         INFO(cdev, "%s ready\n", composite->name);
1040         return 0;
1041
1042 fail:
1043         composite_unbind(gadget);
1044         return status;
1045 }
1046
1047 /*-------------------------------------------------------------------------*/
1048
1049 static void
1050 composite_suspend(struct usb_gadget *gadget)
1051 {
1052         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1053         struct usb_function             *f;
1054
1055         /* REVISIT:  should we have config level
1056          * suspend/resume callbacks?
1057          */
1058         DBG(cdev, "suspend\n");
1059         if (cdev->config) {
1060                 list_for_each_entry(f, &cdev->config->functions, list) {
1061                         if (f->suspend)
1062                                 f->suspend(f);
1063                 }
1064         }
1065         if (composite->suspend)
1066                 composite->suspend(cdev);
1067 }
1068
1069 static void
1070 composite_resume(struct usb_gadget *gadget)
1071 {
1072         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1073         struct usb_function             *f;
1074
1075         /* REVISIT:  should we have config level
1076          * suspend/resume callbacks?
1077          */
1078         DBG(cdev, "resume\n");
1079         if (composite->resume)
1080                 composite->resume(cdev);
1081         if (cdev->config) {
1082                 list_for_each_entry(f, &cdev->config->functions, list) {
1083                         if (f->resume)
1084                                 f->resume(f);
1085                 }
1086         }
1087 }
1088
1089 /*-------------------------------------------------------------------------*/
1090
1091 static struct usb_gadget_driver composite_driver = {
1092         .speed          = USB_SPEED_HIGH,
1093
1094         .bind           = composite_bind,
1095         /* .unbind              = __exit_p(composite_unbind), */
1096         .unbind         = composite_unbind,
1097
1098         .setup          = composite_setup,
1099         .disconnect     = composite_disconnect,
1100
1101         .suspend        = composite_suspend,
1102         .resume         = composite_resume,
1103
1104         .driver = {
1105                 .owner          = THIS_MODULE,
1106         },
1107 };
1108
1109 /**
1110  * usb_composite_register() - register a composite driver
1111  * @driver: the driver to register
1112  * Context: single threaded during gadget setup
1113  *
1114  * This function is used to register drivers using the composite driver
1115  * framework.  The return value is zero, or a negative errno value.
1116  * Those values normally come from the driver's @bind method, which does
1117  * all the work of setting up the driver to match the hardware.
1118  *
1119  * On successful return, the gadget is ready to respond to requests from
1120  * the host, unless one of its components invokes usb_gadget_disconnect()
1121  * while it was binding.  That would usually be done in order to wait for
1122  * some userspace participation.
1123  */
1124 int __init usb_composite_register(struct usb_composite_driver *driver)
1125 {
1126         if (!driver || !driver->dev || !driver->bind || composite)
1127                 return -EINVAL;
1128
1129         if (!driver->name)
1130                 driver->name = "composite";
1131         composite_driver.function =  (char *) driver->name;
1132         composite_driver.driver.name = driver->name;
1133         composite = driver;
1134
1135         return usb_gadget_register_driver(&composite_driver);
1136 }
1137
1138 /**
1139  * usb_composite_unregister() - unregister a composite driver
1140  * @driver: the driver to unregister
1141  *
1142  * This function is used to unregister drivers using the composite
1143  * driver framework.
1144  */
1145 void /* __exit */ usb_composite_unregister(struct usb_composite_driver *driver)
1146 {
1147         if (composite != driver)
1148                 return;
1149         usb_gadget_unregister_driver(&composite_driver);
1150 }