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