modpost: add support for hid
[linux-2.6.git] / drivers / hid / hid-core.c
1 /*
2  *  HID support for Linux
3  *
4  *  Copyright (c) 1999 Andreas Gal
5  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
6  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
7  *  Copyright (c) 2006-2007 Jiri Kosina
8  */
9
10 /*
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License as published by the Free
13  * Software Foundation; either version 2 of the License, or (at your option)
14  * any later version.
15  */
16
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
22 #include <linux/mm.h>
23 #include <linux/spinlock.h>
24 #include <asm/unaligned.h>
25 #include <asm/byteorder.h>
26 #include <linux/input.h>
27 #include <linux/wait.h>
28 #include <linux/vmalloc.h>
29 #include <linux/sched.h>
30
31 #include <linux/hid.h>
32 #include <linux/hiddev.h>
33 #include <linux/hid-debug.h>
34 #include <linux/hidraw.h>
35
36 /*
37  * Version Information
38  */
39
40 #define DRIVER_VERSION "v2.6"
41 #define DRIVER_AUTHOR "Andreas Gal, Vojtech Pavlik, Jiri Kosina"
42 #define DRIVER_DESC "HID core driver"
43 #define DRIVER_LICENSE "GPL"
44
45 #ifdef CONFIG_HID_DEBUG
46 int hid_debug = 0;
47 module_param_named(debug, hid_debug, int, 0600);
48 MODULE_PARM_DESC(debug, "HID debugging (0=off, 1=probing info, 2=continuous data dumping)");
49 EXPORT_SYMBOL_GPL(hid_debug);
50 #endif
51
52 /*
53  * Register a new report for a device.
54  */
55
56 static struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id)
57 {
58         struct hid_report_enum *report_enum = device->report_enum + type;
59         struct hid_report *report;
60
61         if (report_enum->report_id_hash[id])
62                 return report_enum->report_id_hash[id];
63
64         if (!(report = kzalloc(sizeof(struct hid_report), GFP_KERNEL)))
65                 return NULL;
66
67         if (id != 0)
68                 report_enum->numbered = 1;
69
70         report->id = id;
71         report->type = type;
72         report->size = 0;
73         report->device = device;
74         report_enum->report_id_hash[id] = report;
75
76         list_add_tail(&report->list, &report_enum->report_list);
77
78         return report;
79 }
80
81 /*
82  * Register a new field for this report.
83  */
84
85 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
86 {
87         struct hid_field *field;
88
89         if (report->maxfield == HID_MAX_FIELDS) {
90                 dbg_hid("too many fields in report\n");
91                 return NULL;
92         }
93
94         if (!(field = kzalloc(sizeof(struct hid_field) + usages * sizeof(struct hid_usage)
95                 + values * sizeof(unsigned), GFP_KERNEL))) return NULL;
96
97         field->index = report->maxfield++;
98         report->field[field->index] = field;
99         field->usage = (struct hid_usage *)(field + 1);
100         field->value = (s32 *)(field->usage + usages);
101         field->report = report;
102
103         return field;
104 }
105
106 /*
107  * Open a collection. The type/usage is pushed on the stack.
108  */
109
110 static int open_collection(struct hid_parser *parser, unsigned type)
111 {
112         struct hid_collection *collection;
113         unsigned usage;
114
115         usage = parser->local.usage[0];
116
117         if (parser->collection_stack_ptr == HID_COLLECTION_STACK_SIZE) {
118                 dbg_hid("collection stack overflow\n");
119                 return -1;
120         }
121
122         if (parser->device->maxcollection == parser->device->collection_size) {
123                 collection = kmalloc(sizeof(struct hid_collection) *
124                                 parser->device->collection_size * 2, GFP_KERNEL);
125                 if (collection == NULL) {
126                         dbg_hid("failed to reallocate collection array\n");
127                         return -1;
128                 }
129                 memcpy(collection, parser->device->collection,
130                         sizeof(struct hid_collection) *
131                         parser->device->collection_size);
132                 memset(collection + parser->device->collection_size, 0,
133                         sizeof(struct hid_collection) *
134                         parser->device->collection_size);
135                 kfree(parser->device->collection);
136                 parser->device->collection = collection;
137                 parser->device->collection_size *= 2;
138         }
139
140         parser->collection_stack[parser->collection_stack_ptr++] =
141                 parser->device->maxcollection;
142
143         collection = parser->device->collection +
144                 parser->device->maxcollection++;
145         collection->type = type;
146         collection->usage = usage;
147         collection->level = parser->collection_stack_ptr - 1;
148
149         if (type == HID_COLLECTION_APPLICATION)
150                 parser->device->maxapplication++;
151
152         return 0;
153 }
154
155 /*
156  * Close a collection.
157  */
158
159 static int close_collection(struct hid_parser *parser)
160 {
161         if (!parser->collection_stack_ptr) {
162                 dbg_hid("collection stack underflow\n");
163                 return -1;
164         }
165         parser->collection_stack_ptr--;
166         return 0;
167 }
168
169 /*
170  * Climb up the stack, search for the specified collection type
171  * and return the usage.
172  */
173
174 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
175 {
176         int n;
177         for (n = parser->collection_stack_ptr - 1; n >= 0; n--)
178                 if (parser->device->collection[parser->collection_stack[n]].type == type)
179                         return parser->device->collection[parser->collection_stack[n]].usage;
180         return 0; /* we know nothing about this usage type */
181 }
182
183 /*
184  * Add a usage to the temporary parser table.
185  */
186
187 static int hid_add_usage(struct hid_parser *parser, unsigned usage)
188 {
189         if (parser->local.usage_index >= HID_MAX_USAGES) {
190                 dbg_hid("usage index exceeded\n");
191                 return -1;
192         }
193         parser->local.usage[parser->local.usage_index] = usage;
194         parser->local.collection_index[parser->local.usage_index] =
195                 parser->collection_stack_ptr ?
196                 parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
197         parser->local.usage_index++;
198         return 0;
199 }
200
201 /*
202  * Register a new field for this report.
203  */
204
205 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
206 {
207         struct hid_report *report;
208         struct hid_field *field;
209         int usages;
210         unsigned offset;
211         int i;
212
213         if (!(report = hid_register_report(parser->device, report_type, parser->global.report_id))) {
214                 dbg_hid("hid_register_report failed\n");
215                 return -1;
216         }
217
218         if (parser->global.logical_maximum < parser->global.logical_minimum) {
219                 dbg_hid("logical range invalid %d %d\n", parser->global.logical_minimum, parser->global.logical_maximum);
220                 return -1;
221         }
222
223         offset = report->size;
224         report->size += parser->global.report_size * parser->global.report_count;
225
226         if (!parser->local.usage_index) /* Ignore padding fields */
227                 return 0;
228
229         usages = max_t(int, parser->local.usage_index, parser->global.report_count);
230
231         if ((field = hid_register_field(report, usages, parser->global.report_count)) == NULL)
232                 return 0;
233
234         field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
235         field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
236         field->application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
237
238         for (i = 0; i < usages; i++) {
239                 int j = i;
240                 /* Duplicate the last usage we parsed if we have excess values */
241                 if (i >= parser->local.usage_index)
242                         j = parser->local.usage_index - 1;
243                 field->usage[i].hid = parser->local.usage[j];
244                 field->usage[i].collection_index =
245                         parser->local.collection_index[j];
246         }
247
248         field->maxusage = usages;
249         field->flags = flags;
250         field->report_offset = offset;
251         field->report_type = report_type;
252         field->report_size = parser->global.report_size;
253         field->report_count = parser->global.report_count;
254         field->logical_minimum = parser->global.logical_minimum;
255         field->logical_maximum = parser->global.logical_maximum;
256         field->physical_minimum = parser->global.physical_minimum;
257         field->physical_maximum = parser->global.physical_maximum;
258         field->unit_exponent = parser->global.unit_exponent;
259         field->unit = parser->global.unit;
260
261         return 0;
262 }
263
264 /*
265  * Read data value from item.
266  */
267
268 static u32 item_udata(struct hid_item *item)
269 {
270         switch (item->size) {
271                 case 1: return item->data.u8;
272                 case 2: return item->data.u16;
273                 case 4: return item->data.u32;
274         }
275         return 0;
276 }
277
278 static s32 item_sdata(struct hid_item *item)
279 {
280         switch (item->size) {
281                 case 1: return item->data.s8;
282                 case 2: return item->data.s16;
283                 case 4: return item->data.s32;
284         }
285         return 0;
286 }
287
288 /*
289  * Process a global item.
290  */
291
292 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
293 {
294         switch (item->tag) {
295
296                 case HID_GLOBAL_ITEM_TAG_PUSH:
297
298                         if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
299                                 dbg_hid("global enviroment stack overflow\n");
300                                 return -1;
301                         }
302
303                         memcpy(parser->global_stack + parser->global_stack_ptr++,
304                                 &parser->global, sizeof(struct hid_global));
305                         return 0;
306
307                 case HID_GLOBAL_ITEM_TAG_POP:
308
309                         if (!parser->global_stack_ptr) {
310                                 dbg_hid("global enviroment stack underflow\n");
311                                 return -1;
312                         }
313
314                         memcpy(&parser->global, parser->global_stack + --parser->global_stack_ptr,
315                                 sizeof(struct hid_global));
316                         return 0;
317
318                 case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
319                         parser->global.usage_page = item_udata(item);
320                         return 0;
321
322                 case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
323                         parser->global.logical_minimum = item_sdata(item);
324                         return 0;
325
326                 case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
327                         if (parser->global.logical_minimum < 0)
328                                 parser->global.logical_maximum = item_sdata(item);
329                         else
330                                 parser->global.logical_maximum = item_udata(item);
331                         return 0;
332
333                 case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
334                         parser->global.physical_minimum = item_sdata(item);
335                         return 0;
336
337                 case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
338                         if (parser->global.physical_minimum < 0)
339                                 parser->global.physical_maximum = item_sdata(item);
340                         else
341                                 parser->global.physical_maximum = item_udata(item);
342                         return 0;
343
344                 case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
345                         parser->global.unit_exponent = item_sdata(item);
346                         return 0;
347
348                 case HID_GLOBAL_ITEM_TAG_UNIT:
349                         parser->global.unit = item_udata(item);
350                         return 0;
351
352                 case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
353                         if ((parser->global.report_size = item_udata(item)) > 32) {
354                                 dbg_hid("invalid report_size %d\n", parser->global.report_size);
355                                 return -1;
356                         }
357                         return 0;
358
359                 case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
360                         if ((parser->global.report_count = item_udata(item)) > HID_MAX_USAGES) {
361                                 dbg_hid("invalid report_count %d\n", parser->global.report_count);
362                                 return -1;
363                         }
364                         return 0;
365
366                 case HID_GLOBAL_ITEM_TAG_REPORT_ID:
367                         if ((parser->global.report_id = item_udata(item)) == 0) {
368                                 dbg_hid("report_id 0 is invalid\n");
369                                 return -1;
370                         }
371                         return 0;
372
373                 default:
374                         dbg_hid("unknown global tag 0x%x\n", item->tag);
375                         return -1;
376         }
377 }
378
379 /*
380  * Process a local item.
381  */
382
383 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
384 {
385         __u32 data;
386         unsigned n;
387
388         if (item->size == 0) {
389                 dbg_hid("item data expected for local item\n");
390                 return -1;
391         }
392
393         data = item_udata(item);
394
395         switch (item->tag) {
396
397                 case HID_LOCAL_ITEM_TAG_DELIMITER:
398
399                         if (data) {
400                                 /*
401                                  * We treat items before the first delimiter
402                                  * as global to all usage sets (branch 0).
403                                  * In the moment we process only these global
404                                  * items and the first delimiter set.
405                                  */
406                                 if (parser->local.delimiter_depth != 0) {
407                                         dbg_hid("nested delimiters\n");
408                                         return -1;
409                                 }
410                                 parser->local.delimiter_depth++;
411                                 parser->local.delimiter_branch++;
412                         } else {
413                                 if (parser->local.delimiter_depth < 1) {
414                                         dbg_hid("bogus close delimiter\n");
415                                         return -1;
416                                 }
417                                 parser->local.delimiter_depth--;
418                         }
419                         return 1;
420
421                 case HID_LOCAL_ITEM_TAG_USAGE:
422
423                         if (parser->local.delimiter_branch > 1) {
424                                 dbg_hid("alternative usage ignored\n");
425                                 return 0;
426                         }
427
428                         if (item->size <= 2)
429                                 data = (parser->global.usage_page << 16) + data;
430
431                         return hid_add_usage(parser, data);
432
433                 case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
434
435                         if (parser->local.delimiter_branch > 1) {
436                                 dbg_hid("alternative usage ignored\n");
437                                 return 0;
438                         }
439
440                         if (item->size <= 2)
441                                 data = (parser->global.usage_page << 16) + data;
442
443                         parser->local.usage_minimum = data;
444                         return 0;
445
446                 case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
447
448                         if (parser->local.delimiter_branch > 1) {
449                                 dbg_hid("alternative usage ignored\n");
450                                 return 0;
451                         }
452
453                         if (item->size <= 2)
454                                 data = (parser->global.usage_page << 16) + data;
455
456                         for (n = parser->local.usage_minimum; n <= data; n++)
457                                 if (hid_add_usage(parser, n)) {
458                                         dbg_hid("hid_add_usage failed\n");
459                                         return -1;
460                                 }
461                         return 0;
462
463                 default:
464
465                         dbg_hid("unknown local item tag 0x%x\n", item->tag);
466                         return 0;
467         }
468         return 0;
469 }
470
471 /*
472  * Process a main item.
473  */
474
475 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
476 {
477         __u32 data;
478         int ret;
479
480         data = item_udata(item);
481
482         switch (item->tag) {
483                 case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
484                         ret = open_collection(parser, data & 0xff);
485                         break;
486                 case HID_MAIN_ITEM_TAG_END_COLLECTION:
487                         ret = close_collection(parser);
488                         break;
489                 case HID_MAIN_ITEM_TAG_INPUT:
490                         ret = hid_add_field(parser, HID_INPUT_REPORT, data);
491                         break;
492                 case HID_MAIN_ITEM_TAG_OUTPUT:
493                         ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
494                         break;
495                 case HID_MAIN_ITEM_TAG_FEATURE:
496                         ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
497                         break;
498                 default:
499                         dbg_hid("unknown main item tag 0x%x\n", item->tag);
500                         ret = 0;
501         }
502
503         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
504
505         return ret;
506 }
507
508 /*
509  * Process a reserved item.
510  */
511
512 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
513 {
514         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
515         return 0;
516 }
517
518 /*
519  * Free a report and all registered fields. The field->usage and
520  * field->value table's are allocated behind the field, so we need
521  * only to free(field) itself.
522  */
523
524 static void hid_free_report(struct hid_report *report)
525 {
526         unsigned n;
527
528         for (n = 0; n < report->maxfield; n++)
529                 kfree(report->field[n]);
530         kfree(report);
531 }
532
533 /*
534  * Free a device structure, all reports, and all fields.
535  */
536
537 void hid_free_device(struct hid_device *device)
538 {
539         unsigned i,j;
540
541         for (i = 0; i < HID_REPORT_TYPES; i++) {
542                 struct hid_report_enum *report_enum = device->report_enum + i;
543
544                 for (j = 0; j < 256; j++) {
545                         struct hid_report *report = report_enum->report_id_hash[j];
546                         if (report)
547                                 hid_free_report(report);
548                 }
549         }
550
551         kfree(device->rdesc);
552         kfree(device->collection);
553         kfree(device);
554 }
555 EXPORT_SYMBOL_GPL(hid_free_device);
556
557 /*
558  * Fetch a report description item from the data stream. We support long
559  * items, though they are not used yet.
560  */
561
562 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
563 {
564         u8 b;
565
566         if ((end - start) <= 0)
567                 return NULL;
568
569         b = *start++;
570
571         item->type = (b >> 2) & 3;
572         item->tag  = (b >> 4) & 15;
573
574         if (item->tag == HID_ITEM_TAG_LONG) {
575
576                 item->format = HID_ITEM_FORMAT_LONG;
577
578                 if ((end - start) < 2)
579                         return NULL;
580
581                 item->size = *start++;
582                 item->tag  = *start++;
583
584                 if ((end - start) < item->size)
585                         return NULL;
586
587                 item->data.longdata = start;
588                 start += item->size;
589                 return start;
590         }
591
592         item->format = HID_ITEM_FORMAT_SHORT;
593         item->size = b & 3;
594
595         switch (item->size) {
596
597                 case 0:
598                         return start;
599
600                 case 1:
601                         if ((end - start) < 1)
602                                 return NULL;
603                         item->data.u8 = *start++;
604                         return start;
605
606                 case 2:
607                         if ((end - start) < 2)
608                                 return NULL;
609                         item->data.u16 = get_unaligned_le16(start);
610                         start = (__u8 *)((__le16 *)start + 1);
611                         return start;
612
613                 case 3:
614                         item->size++;
615                         if ((end - start) < 4)
616                                 return NULL;
617                         item->data.u32 = get_unaligned_le32(start);
618                         start = (__u8 *)((__le32 *)start + 1);
619                         return start;
620         }
621
622         return NULL;
623 }
624
625 /*
626  * Parse a report description into a hid_device structure. Reports are
627  * enumerated, fields are attached to these reports.
628  */
629
630 struct hid_device *hid_parse_report(__u8 *start, unsigned size)
631 {
632         struct hid_device *device;
633         struct hid_parser *parser;
634         struct hid_item item;
635         __u8 *end;
636         unsigned i;
637         static int (*dispatch_type[])(struct hid_parser *parser,
638                                       struct hid_item *item) = {
639                 hid_parser_main,
640                 hid_parser_global,
641                 hid_parser_local,
642                 hid_parser_reserved
643         };
644
645         if (!(device = kzalloc(sizeof(struct hid_device), GFP_KERNEL)))
646                 return NULL;
647
648         if (!(device->collection = kzalloc(sizeof(struct hid_collection) *
649                                    HID_DEFAULT_NUM_COLLECTIONS, GFP_KERNEL))) {
650                 kfree(device);
651                 return NULL;
652         }
653         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
654
655         for (i = 0; i < HID_REPORT_TYPES; i++)
656                 INIT_LIST_HEAD(&device->report_enum[i].report_list);
657
658         if (!(device->rdesc = kmalloc(size, GFP_KERNEL))) {
659                 kfree(device->collection);
660                 kfree(device);
661                 return NULL;
662         }
663         memcpy(device->rdesc, start, size);
664         device->rsize = size;
665
666         if (!(parser = vmalloc(sizeof(struct hid_parser)))) {
667                 kfree(device->rdesc);
668                 kfree(device->collection);
669                 kfree(device);
670                 return NULL;
671         }
672         memset(parser, 0, sizeof(struct hid_parser));
673         parser->device = device;
674
675         end = start + size;
676         while ((start = fetch_item(start, end, &item)) != NULL) {
677
678                 if (item.format != HID_ITEM_FORMAT_SHORT) {
679                         dbg_hid("unexpected long global item\n");
680                         hid_free_device(device);
681                         vfree(parser);
682                         return NULL;
683                 }
684
685                 if (dispatch_type[item.type](parser, &item)) {
686                         dbg_hid("item %u %u %u %u parsing failed\n",
687                                 item.format, (unsigned)item.size, (unsigned)item.type, (unsigned)item.tag);
688                         hid_free_device(device);
689                         vfree(parser);
690                         return NULL;
691                 }
692
693                 if (start == end) {
694                         if (parser->collection_stack_ptr) {
695                                 dbg_hid("unbalanced collection at end of report description\n");
696                                 hid_free_device(device);
697                                 vfree(parser);
698                                 return NULL;
699                         }
700                         if (parser->local.delimiter_depth) {
701                                 dbg_hid("unbalanced delimiter at end of report description\n");
702                                 hid_free_device(device);
703                                 vfree(parser);
704                                 return NULL;
705                         }
706                         vfree(parser);
707                         return device;
708                 }
709         }
710
711         dbg_hid("item fetching failed at offset %d\n", (int)(end - start));
712         hid_free_device(device);
713         vfree(parser);
714         return NULL;
715 }
716 EXPORT_SYMBOL_GPL(hid_parse_report);
717
718 /*
719  * Convert a signed n-bit integer to signed 32-bit integer. Common
720  * cases are done through the compiler, the screwed things has to be
721  * done by hand.
722  */
723
724 static s32 snto32(__u32 value, unsigned n)
725 {
726         switch (n) {
727                 case 8:  return ((__s8)value);
728                 case 16: return ((__s16)value);
729                 case 32: return ((__s32)value);
730         }
731         return value & (1 << (n - 1)) ? value | (-1 << n) : value;
732 }
733
734 /*
735  * Convert a signed 32-bit integer to a signed n-bit integer.
736  */
737
738 static u32 s32ton(__s32 value, unsigned n)
739 {
740         s32 a = value >> (n - 1);
741         if (a && a != -1)
742                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
743         return value & ((1 << n) - 1);
744 }
745
746 /*
747  * Extract/implement a data field from/to a little endian report (bit array).
748  *
749  * Code sort-of follows HID spec:
750  *     http://www.usb.org/developers/devclass_docs/HID1_11.pdf
751  *
752  * While the USB HID spec allows unlimited length bit fields in "report
753  * descriptors", most devices never use more than 16 bits.
754  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
755  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
756  */
757
758 static __inline__ __u32 extract(__u8 *report, unsigned offset, unsigned n)
759 {
760         u64 x;
761
762         if (n > 32)
763                 printk(KERN_WARNING "HID: extract() called with n (%d) > 32! (%s)\n",
764                                 n, current->comm);
765
766         report += offset >> 3;  /* adjust byte index */
767         offset &= 7;            /* now only need bit offset into one byte */
768         x = get_unaligned_le64(report);
769         x = (x >> offset) & ((1ULL << n) - 1);  /* extract bit field */
770         return (u32) x;
771 }
772
773 /*
774  * "implement" : set bits in a little endian bit stream.
775  * Same concepts as "extract" (see comments above).
776  * The data mangled in the bit stream remains in little endian
777  * order the whole time. It make more sense to talk about
778  * endianness of register values by considering a register
779  * a "cached" copy of the little endiad bit stream.
780  */
781 static __inline__ void implement(__u8 *report, unsigned offset, unsigned n, __u32 value)
782 {
783         u64 x;
784         u64 m = (1ULL << n) - 1;
785
786         if (n > 32)
787                 printk(KERN_WARNING "HID: implement() called with n (%d) > 32! (%s)\n",
788                                 n, current->comm);
789
790         if (value > m)
791                 printk(KERN_WARNING "HID: implement() called with too large value %d! (%s)\n",
792                                 value, current->comm);
793         WARN_ON(value > m);
794         value &= m;
795
796         report += offset >> 3;
797         offset &= 7;
798
799         x = get_unaligned_le64(report);
800         x &= ~(m << offset);
801         x |= ((u64)value) << offset;
802         put_unaligned_le64(x, report);
803 }
804
805 /*
806  * Search an array for a value.
807  */
808
809 static __inline__ int search(__s32 *array, __s32 value, unsigned n)
810 {
811         while (n--) {
812                 if (*array++ == value)
813                         return 0;
814         }
815         return -1;
816 }
817
818 static void hid_process_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value, int interrupt)
819 {
820         hid_dump_input(usage, value);
821         if (hid->claimed & HID_CLAIMED_INPUT)
822                 hidinput_hid_event(hid, field, usage, value);
823         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
824                 hid->hiddev_hid_event(hid, field, usage, value);
825 }
826
827 /*
828  * Analyse a received field, and fetch the data from it. The field
829  * content is stored for next report processing (we do differential
830  * reporting to the layer).
831  */
832
833 static void hid_input_field(struct hid_device *hid, struct hid_field *field,
834                             __u8 *data, int interrupt)
835 {
836         unsigned n;
837         unsigned count = field->report_count;
838         unsigned offset = field->report_offset;
839         unsigned size = field->report_size;
840         __s32 min = field->logical_minimum;
841         __s32 max = field->logical_maximum;
842         __s32 *value;
843
844         if (!(value = kmalloc(sizeof(__s32) * count, GFP_ATOMIC)))
845                 return;
846
847         for (n = 0; n < count; n++) {
848
849                         value[n] = min < 0 ? snto32(extract(data, offset + n * size, size), size) :
850                                                     extract(data, offset + n * size, size);
851
852                         if (!(field->flags & HID_MAIN_ITEM_VARIABLE) /* Ignore report if ErrorRollOver */
853                             && value[n] >= min && value[n] <= max
854                             && field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
855                                 goto exit;
856         }
857
858         for (n = 0; n < count; n++) {
859
860                 if (HID_MAIN_ITEM_VARIABLE & field->flags) {
861                         hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
862                         continue;
863                 }
864
865                 if (field->value[n] >= min && field->value[n] <= max
866                         && field->usage[field->value[n] - min].hid
867                         && search(value, field->value[n], count))
868                                 hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
869
870                 if (value[n] >= min && value[n] <= max
871                         && field->usage[value[n] - min].hid
872                         && search(field->value, value[n], count))
873                                 hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
874         }
875
876         memcpy(field->value, value, count * sizeof(__s32));
877 exit:
878         kfree(value);
879 }
880
881 /*
882  * Output the field into the report.
883  */
884
885 static void hid_output_field(struct hid_field *field, __u8 *data)
886 {
887         unsigned count = field->report_count;
888         unsigned offset = field->report_offset;
889         unsigned size = field->report_size;
890         unsigned bitsused = offset + count * size;
891         unsigned n;
892
893         /* make sure the unused bits in the last byte are zeros */
894         if (count > 0 && size > 0 && (bitsused % 8) != 0)
895                 data[(bitsused-1)/8] &= (1 << (bitsused % 8)) - 1;
896
897         for (n = 0; n < count; n++) {
898                 if (field->logical_minimum < 0) /* signed values */
899                         implement(data, offset + n * size, size, s32ton(field->value[n], size));
900                 else                            /* unsigned values */
901                         implement(data, offset + n * size, size, field->value[n]);
902         }
903 }
904
905 /*
906  * Create a report.
907  */
908
909 void hid_output_report(struct hid_report *report, __u8 *data)
910 {
911         unsigned n;
912
913         if (report->id > 0)
914                 *data++ = report->id;
915
916         for (n = 0; n < report->maxfield; n++)
917                 hid_output_field(report->field[n], data);
918 }
919 EXPORT_SYMBOL_GPL(hid_output_report);
920
921 /*
922  * Set a field value. The report this field belongs to has to be
923  * created and transferred to the device, to set this value in the
924  * device.
925  */
926
927 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
928 {
929         unsigned size = field->report_size;
930
931         hid_dump_input(field->usage + offset, value);
932
933         if (offset >= field->report_count) {
934                 dbg_hid("offset (%d) exceeds report_count (%d)\n", offset, field->report_count);
935                 hid_dump_field(field, 8);
936                 return -1;
937         }
938         if (field->logical_minimum < 0) {
939                 if (value != snto32(s32ton(value, size), size)) {
940                         dbg_hid("value %d is out of range\n", value);
941                         return -1;
942                 }
943         }
944         field->value[offset] = value;
945         return 0;
946 }
947 EXPORT_SYMBOL_GPL(hid_set_field);
948
949 int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int interrupt)
950 {
951         struct hid_report_enum *report_enum = hid->report_enum + type;
952         struct hid_report *report;
953         int n, rsize, i;
954
955         if (!hid)
956                 return -ENODEV;
957
958         if (!size) {
959                 dbg_hid("empty report\n");
960                 return -1;
961         }
962
963         dbg_hid("report (size %u) (%snumbered)\n", size, report_enum->numbered ? "" : "un");
964
965         n = 0;                          /* Normally report number is 0 */
966         if (report_enum->numbered) {    /* Device uses numbered reports, data[0] is report number */
967                 n = *data++;
968                 size--;
969         }
970
971         /* dump the report */
972         dbg_hid("report %d (size %u) = ", n, size);
973         for (i = 0; i < size; i++)
974                 dbg_hid_line(" %02x", data[i]);
975         dbg_hid_line("\n");
976
977         if (!(report = report_enum->report_id_hash[n])) {
978                 dbg_hid("undefined report_id %d received\n", n);
979                 return -1;
980         }
981
982         rsize = ((report->size - 1) >> 3) + 1;
983
984         if (size < rsize) {
985                 dbg_hid("report %d is too short, (%d < %d)\n", report->id, size, rsize);
986                 memset(data + size, 0, rsize - size);
987         }
988
989         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
990                 hid->hiddev_report_event(hid, report);
991         if (hid->claimed & HID_CLAIMED_HIDRAW) {
992                 /* numbered reports need to be passed with the report num */
993                 if (report_enum->numbered)
994                         hidraw_report_event(hid, data - 1, size + 1);
995                 else
996                         hidraw_report_event(hid, data, size);
997         }
998
999         for (n = 0; n < report->maxfield; n++)
1000                 hid_input_field(hid, report->field[n], data, interrupt);
1001
1002         if (hid->claimed & HID_CLAIMED_INPUT)
1003                 hidinput_report_event(hid, report);
1004
1005         return 0;
1006 }
1007 EXPORT_SYMBOL_GPL(hid_input_report);
1008
1009 static int __init hid_init(void)
1010 {
1011         return hidraw_init();
1012 }
1013
1014 static void __exit hid_exit(void)
1015 {
1016         hidraw_exit();
1017 }
1018
1019 module_init(hid_init);
1020 module_exit(hid_exit);
1021
1022 MODULE_LICENSE(DRIVER_LICENSE);
1023