Merge branch 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip...
[linux-2.6] / 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_interface_id() - allocate an unused interface ID
132  * @config: configuration associated with the interface
133  * @function: function handling the interface
134  * Context: single threaded during gadget setup
135  *
136  * usb_interface_id() is called from usb_function.bind() callbacks to
137  * allocate new interface IDs.  The function driver will then store that
138  * ID in interface, association, CDC union, and other descriptors.  It
139  * will also handle any control requests targetted at that interface,
140  * particularly changing its altsetting via set_alt().  There may
141  * also be class-specific or vendor-specific requests to handle.
142  *
143  * All interface identifier should be allocated using this routine, to
144  * ensure that for example different functions don't wrongly assign
145  * different meanings to the same identifier.  Note that since interface
146  * identifers are configuration-specific, functions used in more than
147  * one configuration (or more than once in a given configuration) need
148  * multiple versions of the relevant descriptors.
149  *
150  * Returns the interface ID which was allocated; or -ENODEV if no
151  * more interface IDs can be allocated.
152  */
153 int __init usb_interface_id(struct usb_configuration *config,
154                 struct usb_function *function)
155 {
156         unsigned id = config->next_interface_id;
157
158         if (id < MAX_CONFIG_INTERFACES) {
159                 config->interface[id] = function;
160                 config->next_interface_id = id + 1;
161                 return id;
162         }
163         return -ENODEV;
164 }
165
166 static int config_buf(struct usb_configuration *config,
167                 enum usb_device_speed speed, void *buf, u8 type)
168 {
169         struct usb_config_descriptor    *c = buf;
170         void                            *next = buf + USB_DT_CONFIG_SIZE;
171         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
172         struct usb_function             *f;
173         int                             status;
174
175         /* write the config descriptor */
176         c = buf;
177         c->bLength = USB_DT_CONFIG_SIZE;
178         c->bDescriptorType = type;
179         /* wTotalLength is written later */
180         c->bNumInterfaces = config->next_interface_id;
181         c->bConfigurationValue = config->bConfigurationValue;
182         c->iConfiguration = config->iConfiguration;
183         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
184         c->bMaxPower = config->bMaxPower;
185
186         /* There may be e.g. OTG descriptors */
187         if (config->descriptors) {
188                 status = usb_descriptor_fillbuf(next, len,
189                                 config->descriptors);
190                 if (status < 0)
191                         return status;
192                 len -= status;
193                 next += status;
194         }
195
196         /* add each function's descriptors */
197         list_for_each_entry(f, &config->functions, list) {
198                 struct usb_descriptor_header **descriptors;
199
200                 if (speed == USB_SPEED_HIGH)
201                         descriptors = f->hs_descriptors;
202                 else
203                         descriptors = f->descriptors;
204                 if (!descriptors)
205                         continue;
206                 status = usb_descriptor_fillbuf(next, len,
207                         (const struct usb_descriptor_header **) descriptors);
208                 if (status < 0)
209                         return status;
210                 len -= status;
211                 next += status;
212         }
213
214         len = next - buf;
215         c->wTotalLength = cpu_to_le16(len);
216         return len;
217 }
218
219 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
220 {
221         struct usb_gadget               *gadget = cdev->gadget;
222         struct usb_configuration        *c;
223         u8                              type = w_value >> 8;
224         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
225
226         if (gadget_is_dualspeed(gadget)) {
227                 int                     hs = 0;
228
229                 if (gadget->speed == USB_SPEED_HIGH)
230                         hs = 1;
231                 if (type == USB_DT_OTHER_SPEED_CONFIG)
232                         hs = !hs;
233                 if (hs)
234                         speed = USB_SPEED_HIGH;
235
236         }
237
238         /* This is a lookup by config *INDEX* */
239         w_value &= 0xff;
240         list_for_each_entry(c, &cdev->configs, list) {
241                 /* ignore configs that won't work at this speed */
242                 if (speed == USB_SPEED_HIGH) {
243                         if (!c->highspeed)
244                                 continue;
245                 } else {
246                         if (!c->fullspeed)
247                                 continue;
248                 }
249                 if (w_value == 0)
250                         return config_buf(c, speed, cdev->req->buf, type);
251                 w_value--;
252         }
253         return -EINVAL;
254 }
255
256 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
257 {
258         struct usb_gadget               *gadget = cdev->gadget;
259         struct usb_configuration        *c;
260         unsigned                        count = 0;
261         int                             hs = 0;
262
263         if (gadget_is_dualspeed(gadget)) {
264                 if (gadget->speed == USB_SPEED_HIGH)
265                         hs = 1;
266                 if (type == USB_DT_DEVICE_QUALIFIER)
267                         hs = !hs;
268         }
269         list_for_each_entry(c, &cdev->configs, list) {
270                 /* ignore configs that won't work at this speed */
271                 if (hs) {
272                         if (!c->highspeed)
273                                 continue;
274                 } else {
275                         if (!c->fullspeed)
276                                 continue;
277                 }
278                 count++;
279         }
280         return count;
281 }
282
283 static void device_qual(struct usb_composite_dev *cdev)
284 {
285         struct usb_qualifier_descriptor *qual = cdev->req->buf;
286
287         qual->bLength = sizeof(*qual);
288         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
289         /* POLICY: same bcdUSB and device type info at both speeds */
290         qual->bcdUSB = cdev->desc.bcdUSB;
291         qual->bDeviceClass = cdev->desc.bDeviceClass;
292         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
293         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
294         /* ASSUME same EP0 fifo size at both speeds */
295         qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
296         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
297         qual->bRESERVED = 0;
298 }
299
300 /*-------------------------------------------------------------------------*/
301
302 static void reset_config(struct usb_composite_dev *cdev)
303 {
304         struct usb_function             *f;
305
306         DBG(cdev, "reset config\n");
307
308         list_for_each_entry(f, &cdev->config->functions, list) {
309                 if (f->disable)
310                         f->disable(f);
311         }
312         cdev->config = NULL;
313 }
314
315 static int set_config(struct usb_composite_dev *cdev,
316                 const struct usb_ctrlrequest *ctrl, unsigned number)
317 {
318         struct usb_gadget       *gadget = cdev->gadget;
319         struct usb_configuration *c = NULL;
320         int                     result = -EINVAL;
321         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
322         int                     tmp;
323
324         if (cdev->config)
325                 reset_config(cdev);
326
327         if (number) {
328                 list_for_each_entry(c, &cdev->configs, list) {
329                         if (c->bConfigurationValue == number) {
330                                 result = 0;
331                                 break;
332                         }
333                 }
334                 if (result < 0)
335                         goto done;
336         } else
337                 result = 0;
338
339         INFO(cdev, "%s speed config #%d: %s\n",
340                 ({ char *speed;
341                 switch (gadget->speed) {
342                 case USB_SPEED_LOW:     speed = "low"; break;
343                 case USB_SPEED_FULL:    speed = "full"; break;
344                 case USB_SPEED_HIGH:    speed = "high"; break;
345                 default:                speed = "?"; break;
346                 } ; speed; }), number, c ? c->label : "unconfigured");
347
348         if (!c)
349                 goto done;
350
351         cdev->config = c;
352
353         /* Initialize all interfaces by setting them to altsetting zero. */
354         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
355                 struct usb_function     *f = c->interface[tmp];
356
357                 if (!f)
358                         break;
359
360                 result = f->set_alt(f, tmp, 0);
361                 if (result < 0) {
362                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
363                                         tmp, f->name, f, result);
364
365                         reset_config(cdev);
366                         goto done;
367                 }
368         }
369
370         /* when we return, be sure our power usage is valid */
371         power = 2 * c->bMaxPower;
372 done:
373         usb_gadget_vbus_draw(gadget, power);
374         return result;
375 }
376
377 /**
378  * usb_add_config() - add a configuration to a device.
379  * @cdev: wraps the USB gadget
380  * @config: the configuration, with bConfigurationValue assigned
381  * Context: single threaded during gadget setup
382  *
383  * One of the main tasks of a composite driver's bind() routine is to
384  * add each of the configurations it supports, using this routine.
385  *
386  * This function returns the value of the configuration's bind(), which
387  * is zero for success else a negative errno value.  Binding configurations
388  * assigns global resources including string IDs, and per-configuration
389  * resources such as interface IDs and endpoints.
390  */
391 int __init usb_add_config(struct usb_composite_dev *cdev,
392                 struct usb_configuration *config)
393 {
394         int                             status = -EINVAL;
395         struct usb_configuration        *c;
396
397         DBG(cdev, "adding config #%u '%s'/%p\n",
398                         config->bConfigurationValue,
399                         config->label, config);
400
401         if (!config->bConfigurationValue || !config->bind)
402                 goto done;
403
404         /* Prevent duplicate configuration identifiers */
405         list_for_each_entry(c, &cdev->configs, list) {
406                 if (c->bConfigurationValue == config->bConfigurationValue) {
407                         status = -EBUSY;
408                         goto done;
409                 }
410         }
411
412         config->cdev = cdev;
413         list_add_tail(&config->list, &cdev->configs);
414
415         INIT_LIST_HEAD(&config->functions);
416         config->next_interface_id = 0;
417
418         status = config->bind(config);
419         if (status < 0) {
420                 list_del(&config->list);
421                 config->cdev = NULL;
422         } else {
423                 unsigned        i;
424
425                 DBG(cdev, "cfg %d/%p speeds:%s%s\n",
426                         config->bConfigurationValue, config,
427                         config->highspeed ? " high" : "",
428                         config->fullspeed
429                                 ? (gadget_is_dualspeed(cdev->gadget)
430                                         ? " full"
431                                         : " full/low")
432                                 : "");
433
434                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
435                         struct usb_function     *f = config->interface[i];
436
437                         if (!f)
438                                 continue;
439                         DBG(cdev, "  interface %d = %s/%p\n",
440                                 i, f->name, f);
441                 }
442         }
443
444         /* set_alt(), or next config->bind(), sets up
445          * ep->driver_data as needed.
446          */
447         usb_ep_autoconfig_reset(cdev->gadget);
448
449 done:
450         if (status)
451                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
452                                 config->bConfigurationValue, status);
453         return status;
454 }
455
456 /*-------------------------------------------------------------------------*/
457
458 /* We support strings in multiple languages ... string descriptor zero
459  * says which languages are supported.  The typical case will be that
460  * only one language (probably English) is used, with I18N handled on
461  * the host side.
462  */
463
464 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
465 {
466         const struct usb_gadget_strings *s;
467         u16                             language;
468         __le16                          *tmp;
469
470         while (*sp) {
471                 s = *sp;
472                 language = cpu_to_le16(s->language);
473                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
474                         if (*tmp == language)
475                                 goto repeat;
476                 }
477                 *tmp++ = language;
478 repeat:
479                 sp++;
480         }
481 }
482
483 static int lookup_string(
484         struct usb_gadget_strings       **sp,
485         void                            *buf,
486         u16                             language,
487         int                             id
488 )
489 {
490         struct usb_gadget_strings       *s;
491         int                             value;
492
493         while (*sp) {
494                 s = *sp++;
495                 if (s->language != language)
496                         continue;
497                 value = usb_gadget_get_string(s, id, buf);
498                 if (value > 0)
499                         return value;
500         }
501         return -EINVAL;
502 }
503
504 static int get_string(struct usb_composite_dev *cdev,
505                 void *buf, u16 language, int id)
506 {
507         struct usb_configuration        *c;
508         struct usb_function             *f;
509         int                             len;
510
511         /* Yes, not only is USB's I18N support probably more than most
512          * folk will ever care about ... also, it's all supported here.
513          * (Except for UTF8 support for Unicode's "Astral Planes".)
514          */
515
516         /* 0 == report all available language codes */
517         if (id == 0) {
518                 struct usb_string_descriptor    *s = buf;
519                 struct usb_gadget_strings       **sp;
520
521                 memset(s, 0, 256);
522                 s->bDescriptorType = USB_DT_STRING;
523
524                 sp = composite->strings;
525                 if (sp)
526                         collect_langs(sp, s->wData);
527
528                 list_for_each_entry(c, &cdev->configs, list) {
529                         sp = c->strings;
530                         if (sp)
531                                 collect_langs(sp, s->wData);
532
533                         list_for_each_entry(f, &c->functions, list) {
534                                 sp = f->strings;
535                                 if (sp)
536                                         collect_langs(sp, s->wData);
537                         }
538                 }
539
540                 for (len = 0; s->wData[len] && len <= 126; len++)
541                         continue;
542                 if (!len)
543                         return -EINVAL;
544
545                 s->bLength = 2 * (len + 1);
546                 return s->bLength;
547         }
548
549         /* Otherwise, look up and return a specified string.  String IDs
550          * are device-scoped, so we look up each string table we're told
551          * about.  These lookups are infrequent; simpler-is-better here.
552          */
553         if (composite->strings) {
554                 len = lookup_string(composite->strings, buf, language, id);
555                 if (len > 0)
556                         return len;
557         }
558         list_for_each_entry(c, &cdev->configs, list) {
559                 if (c->strings) {
560                         len = lookup_string(c->strings, buf, language, id);
561                         if (len > 0)
562                                 return len;
563                 }
564                 list_for_each_entry(f, &c->functions, list) {
565                         if (!f->strings)
566                                 continue;
567                         len = lookup_string(f->strings, buf, language, id);
568                         if (len > 0)
569                                 return len;
570                 }
571         }
572         return -EINVAL;
573 }
574
575 /**
576  * usb_string_id() - allocate an unused string ID
577  * @cdev: the device whose string descriptor IDs are being allocated
578  * Context: single threaded during gadget setup
579  *
580  * @usb_string_id() is called from bind() callbacks to allocate
581  * string IDs.  Drivers for functions, configurations, or gadgets will
582  * then store that ID in the appropriate descriptors and string table.
583  *
584  * All string identifier should be allocated using this routine, to
585  * ensure that for example different functions don't wrongly assign
586  * different meanings to the same identifier.
587  */
588 int __init usb_string_id(struct usb_composite_dev *cdev)
589 {
590         if (cdev->next_string_id < 254) {
591                 /* string id 0 is reserved */
592                 cdev->next_string_id++;
593                 return cdev->next_string_id;
594         }
595         return -ENODEV;
596 }
597
598 /*-------------------------------------------------------------------------*/
599
600 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
601 {
602         if (req->status || req->actual != req->length)
603                 DBG((struct usb_composite_dev *) ep->driver_data,
604                                 "setup complete --> %d, %d/%d\n",
605                                 req->status, req->actual, req->length);
606 }
607
608 /*
609  * The setup() callback implements all the ep0 functionality that's
610  * not handled lower down, in hardware or the hardware driver(like
611  * device and endpoint feature flags, and their status).  It's all
612  * housekeeping for the gadget function we're implementing.  Most of
613  * the work is in config and function specific setup.
614  */
615 static int
616 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
617 {
618         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
619         struct usb_request              *req = cdev->req;
620         int                             value = -EOPNOTSUPP;
621         u16                             w_index = le16_to_cpu(ctrl->wIndex);
622         u16                             w_value = le16_to_cpu(ctrl->wValue);
623         u16                             w_length = le16_to_cpu(ctrl->wLength);
624         struct usb_function             *f = NULL;
625
626         /* partial re-init of the response message; the function or the
627          * gadget might need to intercept e.g. a control-OUT completion
628          * when we delegate to it.
629          */
630         req->zero = 0;
631         req->complete = composite_setup_complete;
632         req->length = USB_BUFSIZ;
633         gadget->ep0->driver_data = cdev;
634
635         switch (ctrl->bRequest) {
636
637         /* we handle all standard USB descriptors */
638         case USB_REQ_GET_DESCRIPTOR:
639                 if (ctrl->bRequestType != USB_DIR_IN)
640                         goto unknown;
641                 switch (w_value >> 8) {
642
643                 case USB_DT_DEVICE:
644                         cdev->desc.bNumConfigurations =
645                                 count_configs(cdev, USB_DT_DEVICE);
646                         value = min(w_length, (u16) sizeof cdev->desc);
647                         memcpy(req->buf, &cdev->desc, value);
648                         break;
649                 case USB_DT_DEVICE_QUALIFIER:
650                         if (!gadget_is_dualspeed(gadget))
651                                 break;
652                         device_qual(cdev);
653                         value = min_t(int, w_length,
654                                 sizeof(struct usb_qualifier_descriptor));
655                         break;
656                 case USB_DT_OTHER_SPEED_CONFIG:
657                         if (!gadget_is_dualspeed(gadget))
658                                 break;
659                         /* FALLTHROUGH */
660                 case USB_DT_CONFIG:
661                         value = config_desc(cdev, w_value);
662                         if (value >= 0)
663                                 value = min(w_length, (u16) value);
664                         break;
665                 case USB_DT_STRING:
666                         value = get_string(cdev, req->buf,
667                                         w_index, w_value & 0xff);
668                         if (value >= 0)
669                                 value = min(w_length, (u16) value);
670                         break;
671                 }
672                 break;
673
674         /* any number of configs can work */
675         case USB_REQ_SET_CONFIGURATION:
676                 if (ctrl->bRequestType != 0)
677                         goto unknown;
678                 if (gadget_is_otg(gadget)) {
679                         if (gadget->a_hnp_support)
680                                 DBG(cdev, "HNP available\n");
681                         else if (gadget->a_alt_hnp_support)
682                                 DBG(cdev, "HNP on another port\n");
683                         else
684                                 VDBG(cdev, "HNP inactive\n");
685                 }
686                 spin_lock(&cdev->lock);
687                 value = set_config(cdev, ctrl, w_value);
688                 spin_unlock(&cdev->lock);
689                 break;
690         case USB_REQ_GET_CONFIGURATION:
691                 if (ctrl->bRequestType != USB_DIR_IN)
692                         goto unknown;
693                 if (cdev->config)
694                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
695                 else
696                         *(u8 *)req->buf = 0;
697                 value = min(w_length, (u16) 1);
698                 break;
699
700         /* function drivers must handle get/set altsetting; if there's
701          * no get() method, we know only altsetting zero works.
702          */
703         case USB_REQ_SET_INTERFACE:
704                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
705                         goto unknown;
706                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
707                         break;
708                 f = cdev->config->interface[w_index];
709                 if (!f)
710                         break;
711                 if (w_value && !f->get_alt)
712                         break;
713                 value = f->set_alt(f, w_index, w_value);
714                 break;
715         case USB_REQ_GET_INTERFACE:
716                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
717                         goto unknown;
718                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
719                         break;
720                 f = cdev->config->interface[w_index];
721                 if (!f)
722                         break;
723                 /* lots of interfaces only need altsetting zero... */
724                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
725                 if (value < 0)
726                         break;
727                 *((u8 *)req->buf) = value;
728                 value = min(w_length, (u16) 1);
729                 break;
730         default:
731 unknown:
732                 VDBG(cdev,
733                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
734                         ctrl->bRequestType, ctrl->bRequest,
735                         w_value, w_index, w_length);
736
737                 /* functions always handle their interfaces ... punt other
738                  * recipients (endpoint, other, WUSB, ...) to the current
739                  * configuration code.
740                  *
741                  * REVISIT it could make sense to let the composite device
742                  * take such requests too, if that's ever needed:  to work
743                  * in config 0, etc.
744                  */
745                 if ((ctrl->bRequestType & USB_RECIP_MASK)
746                                 == USB_RECIP_INTERFACE) {
747                         f = cdev->config->interface[w_index];
748                         if (f && f->setup)
749                                 value = f->setup(f, ctrl);
750                         else
751                                 f = NULL;
752                 }
753                 if (value < 0 && !f) {
754                         struct usb_configuration        *c;
755
756                         c = cdev->config;
757                         if (c && c->setup)
758                                 value = c->setup(c, ctrl);
759                 }
760
761                 goto done;
762         }
763
764         /* respond with data transfer before status phase? */
765         if (value >= 0) {
766                 req->length = value;
767                 req->zero = value < w_length;
768                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
769                 if (value < 0) {
770                         DBG(cdev, "ep_queue --> %d\n", value);
771                         req->status = 0;
772                         composite_setup_complete(gadget->ep0, req);
773                 }
774         }
775
776 done:
777         /* device either stalls (value < 0) or reports success */
778         return value;
779 }
780
781 static void composite_disconnect(struct usb_gadget *gadget)
782 {
783         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
784         unsigned long                   flags;
785
786         /* REVISIT:  should we have config and device level
787          * disconnect callbacks?
788          */
789         spin_lock_irqsave(&cdev->lock, flags);
790         if (cdev->config)
791                 reset_config(cdev);
792         spin_unlock_irqrestore(&cdev->lock, flags);
793 }
794
795 /*-------------------------------------------------------------------------*/
796
797 static void /* __init_or_exit */
798 composite_unbind(struct usb_gadget *gadget)
799 {
800         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
801
802         /* composite_disconnect() must already have been called
803          * by the underlying peripheral controller driver!
804          * so there's no i/o concurrency that could affect the
805          * state protected by cdev->lock.
806          */
807         WARN_ON(cdev->config);
808
809         while (!list_empty(&cdev->configs)) {
810                 struct usb_configuration        *c;
811
812                 c = list_first_entry(&cdev->configs,
813                                 struct usb_configuration, list);
814                 while (!list_empty(&c->functions)) {
815                         struct usb_function             *f;
816
817                         f = list_first_entry(&c->functions,
818                                         struct usb_function, list);
819                         list_del(&f->list);
820                         if (f->unbind) {
821                                 DBG(cdev, "unbind function '%s'/%p\n",
822                                                 f->name, f);
823                                 f->unbind(c, f);
824                                 /* may free memory for "f" */
825                         }
826                 }
827                 list_del(&c->list);
828                 if (c->unbind) {
829                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
830                         c->unbind(c);
831                         /* may free memory for "c" */
832                 }
833         }
834         if (composite->unbind)
835                 composite->unbind(cdev);
836
837         if (cdev->req) {
838                 kfree(cdev->req->buf);
839                 usb_ep_free_request(gadget->ep0, cdev->req);
840         }
841         kfree(cdev);
842         set_gadget_data(gadget, NULL);
843         composite = NULL;
844 }
845
846 static void __init
847 string_override_one(struct usb_gadget_strings *tab, u8 id, const char *s)
848 {
849         struct usb_string               *str = tab->strings;
850
851         for (str = tab->strings; str->s; str++) {
852                 if (str->id == id) {
853                         str->s = s;
854                         return;
855                 }
856         }
857 }
858
859 static void __init
860 string_override(struct usb_gadget_strings **tab, u8 id, const char *s)
861 {
862         while (*tab) {
863                 string_override_one(*tab, id, s);
864                 tab++;
865         }
866 }
867
868 static int __init composite_bind(struct usb_gadget *gadget)
869 {
870         struct usb_composite_dev        *cdev;
871         int                             status = -ENOMEM;
872
873         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
874         if (!cdev)
875                 return status;
876
877         spin_lock_init(&cdev->lock);
878         cdev->gadget = gadget;
879         set_gadget_data(gadget, cdev);
880         INIT_LIST_HEAD(&cdev->configs);
881
882         /* preallocate control response and buffer */
883         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
884         if (!cdev->req)
885                 goto fail;
886         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
887         if (!cdev->req->buf)
888                 goto fail;
889         cdev->req->complete = composite_setup_complete;
890         gadget->ep0->driver_data = cdev;
891
892         cdev->bufsiz = USB_BUFSIZ;
893         cdev->driver = composite;
894
895         usb_gadget_set_selfpowered(gadget);
896
897         /* interface and string IDs start at zero via kzalloc.
898          * we force endpoints to start unassigned; few controller
899          * drivers will zero ep->driver_data.
900          */
901         usb_ep_autoconfig_reset(cdev->gadget);
902
903         /* composite gadget needs to assign strings for whole device (like
904          * serial number), register function drivers, potentially update
905          * power state and consumption, etc
906          */
907         status = composite->bind(cdev);
908         if (status < 0)
909                 goto fail;
910
911         cdev->desc = *composite->dev;
912         cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
913
914         /* standardized runtime overrides for device ID data */
915         if (idVendor)
916                 cdev->desc.idVendor = cpu_to_le16(idVendor);
917         if (idProduct)
918                 cdev->desc.idProduct = cpu_to_le16(idProduct);
919         if (bcdDevice)
920                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
921
922         /* strings can't be assigned before bind() allocates the
923          * releavnt identifiers
924          */
925         if (cdev->desc.iManufacturer && iManufacturer)
926                 string_override(composite->strings,
927                         cdev->desc.iManufacturer, iManufacturer);
928         if (cdev->desc.iProduct && iProduct)
929                 string_override(composite->strings,
930                         cdev->desc.iProduct, iProduct);
931         if (cdev->desc.iSerialNumber && iSerialNumber)
932                 string_override(composite->strings,
933                         cdev->desc.iSerialNumber, iSerialNumber);
934
935         INFO(cdev, "%s ready\n", composite->name);
936         return 0;
937
938 fail:
939         composite_unbind(gadget);
940         return status;
941 }
942
943 /*-------------------------------------------------------------------------*/
944
945 static void
946 composite_suspend(struct usb_gadget *gadget)
947 {
948         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
949         struct usb_function             *f;
950
951         /* REVISIT:  should we have config and device level
952          * suspend/resume callbacks?
953          */
954         DBG(cdev, "suspend\n");
955         if (cdev->config) {
956                 list_for_each_entry(f, &cdev->config->functions, list) {
957                         if (f->suspend)
958                                 f->suspend(f);
959                 }
960         }
961 }
962
963 static void
964 composite_resume(struct usb_gadget *gadget)
965 {
966         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
967         struct usb_function             *f;
968
969         /* REVISIT:  should we have config and device level
970          * suspend/resume callbacks?
971          */
972         DBG(cdev, "resume\n");
973         if (cdev->config) {
974                 list_for_each_entry(f, &cdev->config->functions, list) {
975                         if (f->resume)
976                                 f->resume(f);
977                 }
978         }
979 }
980
981 /*-------------------------------------------------------------------------*/
982
983 static struct usb_gadget_driver composite_driver = {
984         .speed          = USB_SPEED_HIGH,
985
986         .bind           = composite_bind,
987         .unbind         = __exit_p(composite_unbind),
988
989         .setup          = composite_setup,
990         .disconnect     = composite_disconnect,
991
992         .suspend        = composite_suspend,
993         .resume         = composite_resume,
994
995         .driver = {
996                 .owner          = THIS_MODULE,
997         },
998 };
999
1000 /**
1001  * usb_composite_register() - register a composite driver
1002  * @driver: the driver to register
1003  * Context: single threaded during gadget setup
1004  *
1005  * This function is used to register drivers using the composite driver
1006  * framework.  The return value is zero, or a negative errno value.
1007  * Those values normally come from the driver's @bind method, which does
1008  * all the work of setting up the driver to match the hardware.
1009  *
1010  * On successful return, the gadget is ready to respond to requests from
1011  * the host, unless one of its components invokes usb_gadget_disconnect()
1012  * while it was binding.  That would usually be done in order to wait for
1013  * some userspace participation.
1014  */
1015 int __init usb_composite_register(struct usb_composite_driver *driver)
1016 {
1017         if (!driver || !driver->dev || !driver->bind || composite)
1018                 return -EINVAL;
1019
1020         if (!driver->name)
1021                 driver->name = "composite";
1022         composite_driver.function =  (char *) driver->name;
1023         composite_driver.driver.name = driver->name;
1024         composite = driver;
1025
1026         return usb_gadget_register_driver(&composite_driver);
1027 }
1028
1029 /**
1030  * usb_composite_unregister() - unregister a composite driver
1031  * @driver: the driver to unregister
1032  *
1033  * This function is used to unregister drivers using the composite
1034  * driver framework.
1035  */
1036 void __exit usb_composite_unregister(struct usb_composite_driver *driver)
1037 {
1038         if (composite != driver)
1039                 return;
1040         usb_gadget_unregister_driver(&composite_driver);
1041 }