HID: i2c-hid: add ACPI support
[~shefty/rdma-dev.git] / drivers / hid / i2c-hid / i2c-hid.c
1 /*
2  * HID over I2C protocol implementation
3  *
4  * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
5  * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
6  * Copyright (c) 2012 Red Hat, Inc
7  *
8  * This code is partly based on "USB HID support for Linux":
9  *
10  *  Copyright (c) 1999 Andreas Gal
11  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
12  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
13  *  Copyright (c) 2007-2008 Oliver Neukum
14  *  Copyright (c) 2006-2010 Jiri Kosina
15  *
16  * This file is subject to the terms and conditions of the GNU General Public
17  * License.  See the file COPYING in the main directory of this archive for
18  * more details.
19  */
20
21 #include <linux/module.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/input.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
27 #include <linux/pm.h>
28 #include <linux/device.h>
29 #include <linux/wait.h>
30 #include <linux/err.h>
31 #include <linux/string.h>
32 #include <linux/list.h>
33 #include <linux/jiffies.h>
34 #include <linux/kernel.h>
35 #include <linux/hid.h>
36 #include <linux/mutex.h>
37 #include <linux/acpi.h>
38
39 #include <linux/i2c/i2c-hid.h>
40
41 /* flags */
42 #define I2C_HID_STARTED         (1 << 0)
43 #define I2C_HID_RESET_PENDING   (1 << 1)
44 #define I2C_HID_READ_PENDING    (1 << 2)
45
46 #define I2C_HID_PWR_ON          0x00
47 #define I2C_HID_PWR_SLEEP       0x01
48
49 /* debug option */
50 static bool debug;
51 module_param(debug, bool, 0444);
52 MODULE_PARM_DESC(debug, "print a lot of debug information");
53
54 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
55 do {                                                                      \
56         if (debug)                                                        \
57                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
58 } while (0)
59
60 struct i2c_hid_desc {
61         __le16 wHIDDescLength;
62         __le16 bcdVersion;
63         __le16 wReportDescLength;
64         __le16 wReportDescRegister;
65         __le16 wInputRegister;
66         __le16 wMaxInputLength;
67         __le16 wOutputRegister;
68         __le16 wMaxOutputLength;
69         __le16 wCommandRegister;
70         __le16 wDataRegister;
71         __le16 wVendorID;
72         __le16 wProductID;
73         __le16 wVersionID;
74         __le32 reserved;
75 } __packed;
76
77 struct i2c_hid_cmd {
78         unsigned int registerIndex;
79         __u8 opcode;
80         unsigned int length;
81         bool wait;
82 };
83
84 union command {
85         u8 data[0];
86         struct cmd {
87                 __le16 reg;
88                 __u8 reportTypeID;
89                 __u8 opcode;
90         } __packed c;
91 };
92
93 #define I2C_HID_CMD(opcode_) \
94         .opcode = opcode_, .length = 4, \
95         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
96
97 /* fetch HID descriptor */
98 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
99 /* fetch report descriptors */
100 static const struct i2c_hid_cmd hid_report_descr_cmd = {
101                 .registerIndex = offsetof(struct i2c_hid_desc,
102                         wReportDescRegister),
103                 .opcode = 0x00,
104                 .length = 2 };
105 /* commands */
106 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
107                                                           .wait = true };
108 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
109 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
110 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
111
112 /*
113  * These definitions are not used here, but are defined by the spec.
114  * Keeping them here for documentation purposes.
115  *
116  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
117  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
118  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
119  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
120  */
121
122 static DEFINE_MUTEX(i2c_hid_open_mut);
123
124 /* The main device structure */
125 struct i2c_hid {
126         struct i2c_client       *client;        /* i2c client */
127         struct hid_device       *hid;   /* pointer to corresponding HID dev */
128         union {
129                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
130                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
131         };
132         __le16                  wHIDDescRegister; /* location of the i2c
133                                                    * register of the HID
134                                                    * descriptor. */
135         unsigned int            bufsize;        /* i2c buffer size */
136         char                    *inbuf;         /* Input buffer */
137         char                    *cmdbuf;        /* Command buffer */
138         char                    *argsbuf;       /* Command arguments buffer */
139
140         unsigned long           flags;          /* device flags */
141
142         wait_queue_head_t       wait;           /* For waiting the interrupt */
143
144         struct i2c_hid_platform_data pdata;
145 };
146
147 static int __i2c_hid_command(struct i2c_client *client,
148                 const struct i2c_hid_cmd *command, u8 reportID,
149                 u8 reportType, u8 *args, int args_len,
150                 unsigned char *buf_recv, int data_len)
151 {
152         struct i2c_hid *ihid = i2c_get_clientdata(client);
153         union command *cmd = (union command *)ihid->cmdbuf;
154         int ret;
155         struct i2c_msg msg[2];
156         int msg_num = 1;
157
158         int length = command->length;
159         bool wait = command->wait;
160         unsigned int registerIndex = command->registerIndex;
161
162         /* special case for hid_descr_cmd */
163         if (command == &hid_descr_cmd) {
164                 cmd->c.reg = ihid->wHIDDescRegister;
165         } else {
166                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
167                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
168         }
169
170         if (length > 2) {
171                 cmd->c.opcode = command->opcode;
172                 cmd->c.reportTypeID = reportID | reportType << 4;
173         }
174
175         memcpy(cmd->data + length, args, args_len);
176         length += args_len;
177
178         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
179
180         msg[0].addr = client->addr;
181         msg[0].flags = client->flags & I2C_M_TEN;
182         msg[0].len = length;
183         msg[0].buf = cmd->data;
184         if (data_len > 0) {
185                 msg[1].addr = client->addr;
186                 msg[1].flags = client->flags & I2C_M_TEN;
187                 msg[1].flags |= I2C_M_RD;
188                 msg[1].len = data_len;
189                 msg[1].buf = buf_recv;
190                 msg_num = 2;
191                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
192         }
193
194         if (wait)
195                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
196
197         ret = i2c_transfer(client->adapter, msg, msg_num);
198
199         if (data_len > 0)
200                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
201
202         if (ret != msg_num)
203                 return ret < 0 ? ret : -EIO;
204
205         ret = 0;
206
207         if (wait) {
208                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
209                 if (!wait_event_timeout(ihid->wait,
210                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
211                                 msecs_to_jiffies(5000)))
212                         ret = -ENODATA;
213                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
214         }
215
216         return ret;
217 }
218
219 static int i2c_hid_command(struct i2c_client *client,
220                 const struct i2c_hid_cmd *command,
221                 unsigned char *buf_recv, int data_len)
222 {
223         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
224                                 buf_recv, data_len);
225 }
226
227 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
228                 u8 reportID, unsigned char *buf_recv, int data_len)
229 {
230         struct i2c_hid *ihid = i2c_get_clientdata(client);
231         u8 args[3];
232         int ret;
233         int args_len = 0;
234         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
235
236         i2c_hid_dbg(ihid, "%s\n", __func__);
237
238         if (reportID >= 0x0F) {
239                 args[args_len++] = reportID;
240                 reportID = 0x0F;
241         }
242
243         args[args_len++] = readRegister & 0xFF;
244         args[args_len++] = readRegister >> 8;
245
246         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
247                 reportType, args, args_len, buf_recv, data_len);
248         if (ret) {
249                 dev_err(&client->dev,
250                         "failed to retrieve report from device.\n");
251                 return ret;
252         }
253
254         return 0;
255 }
256
257 static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
258                 u8 reportID, unsigned char *buf, size_t data_len)
259 {
260         struct i2c_hid *ihid = i2c_get_clientdata(client);
261         u8 *args = ihid->argsbuf;
262         int ret;
263         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
264
265         /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
266         u16 size =      2                       /* size */ +
267                         (reportID ? 1 : 0)      /* reportID */ +
268                         data_len                /* buf */;
269         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
270                         2                       /* dataRegister */ +
271                         size                    /* args */;
272         int index = 0;
273
274         i2c_hid_dbg(ihid, "%s\n", __func__);
275
276         if (reportID >= 0x0F) {
277                 args[index++] = reportID;
278                 reportID = 0x0F;
279         }
280
281         args[index++] = dataRegister & 0xFF;
282         args[index++] = dataRegister >> 8;
283
284         args[index++] = size & 0xFF;
285         args[index++] = size >> 8;
286
287         if (reportID)
288                 args[index++] = reportID;
289
290         memcpy(&args[index], buf, data_len);
291
292         ret = __i2c_hid_command(client, &hid_set_report_cmd, reportID,
293                 reportType, args, args_len, NULL, 0);
294         if (ret) {
295                 dev_err(&client->dev, "failed to set a report to device.\n");
296                 return ret;
297         }
298
299         return data_len;
300 }
301
302 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
303 {
304         struct i2c_hid *ihid = i2c_get_clientdata(client);
305         int ret;
306
307         i2c_hid_dbg(ihid, "%s\n", __func__);
308
309         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
310                 0, NULL, 0, NULL, 0);
311         if (ret)
312                 dev_err(&client->dev, "failed to change power setting.\n");
313
314         return ret;
315 }
316
317 static int i2c_hid_hwreset(struct i2c_client *client)
318 {
319         struct i2c_hid *ihid = i2c_get_clientdata(client);
320         int ret;
321
322         i2c_hid_dbg(ihid, "%s\n", __func__);
323
324         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
325         if (ret)
326                 return ret;
327
328         i2c_hid_dbg(ihid, "resetting...\n");
329
330         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
331         if (ret) {
332                 dev_err(&client->dev, "failed to reset device.\n");
333                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
334                 return ret;
335         }
336
337         return 0;
338 }
339
340 static void i2c_hid_get_input(struct i2c_hid *ihid)
341 {
342         int ret, ret_size;
343         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
344
345         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
346         if (ret != size) {
347                 if (ret < 0)
348                         return;
349
350                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
351                         __func__, ret, size);
352                 return;
353         }
354
355         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
356
357         if (!ret_size) {
358                 /* host or device initiated RESET completed */
359                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
360                         wake_up(&ihid->wait);
361                 return;
362         }
363
364         if (ret_size > size) {
365                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
366                         __func__, size, ret_size);
367                 return;
368         }
369
370         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
371
372         if (test_bit(I2C_HID_STARTED, &ihid->flags))
373                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
374                                 ret_size - 2, 1);
375
376         return;
377 }
378
379 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
380 {
381         struct i2c_hid *ihid = dev_id;
382
383         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
384                 return IRQ_HANDLED;
385
386         i2c_hid_get_input(ihid);
387
388         return IRQ_HANDLED;
389 }
390
391 static int i2c_hid_get_report_length(struct hid_report *report)
392 {
393         return ((report->size - 1) >> 3) + 1 +
394                 report->device->report_enum[report->type].numbered + 2;
395 }
396
397 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
398         size_t bufsize)
399 {
400         struct hid_device *hid = report->device;
401         struct i2c_client *client = hid->driver_data;
402         struct i2c_hid *ihid = i2c_get_clientdata(client);
403         unsigned int size, ret_size;
404
405         size = i2c_hid_get_report_length(report);
406         if (i2c_hid_get_report(client,
407                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
408                         report->id, buffer, size))
409                 return;
410
411         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
412
413         ret_size = buffer[0] | (buffer[1] << 8);
414
415         if (ret_size != size) {
416                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
417                         __func__, size, ret_size);
418                 return;
419         }
420
421         /* hid->driver_lock is held as we are in probe function,
422          * we just need to setup the input fields, so using
423          * hid_report_raw_event is safe. */
424         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
425 }
426
427 /*
428  * Initialize all reports
429  */
430 static void i2c_hid_init_reports(struct hid_device *hid)
431 {
432         struct hid_report *report;
433         struct i2c_client *client = hid->driver_data;
434         struct i2c_hid *ihid = i2c_get_clientdata(client);
435         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
436
437         if (!inbuf) {
438                 dev_err(&client->dev, "can not retrieve initial reports\n");
439                 return;
440         }
441
442         list_for_each_entry(report,
443                 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
444                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
445
446         list_for_each_entry(report,
447                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
448                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
449
450         kfree(inbuf);
451 }
452
453 /*
454  * Traverse the supplied list of reports and find the longest
455  */
456 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
457                 unsigned int *max)
458 {
459         struct hid_report *report;
460         unsigned int size;
461
462         /* We should not rely on wMaxInputLength, as some devices may set it to
463          * a wrong length. */
464         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
465                 size = i2c_hid_get_report_length(report);
466                 if (*max < size)
467                         *max = size;
468         }
469 }
470
471 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
472 {
473         kfree(ihid->inbuf);
474         kfree(ihid->argsbuf);
475         kfree(ihid->cmdbuf);
476         ihid->inbuf = NULL;
477         ihid->cmdbuf = NULL;
478         ihid->argsbuf = NULL;
479         ihid->bufsize = 0;
480 }
481
482 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
483 {
484         /* the worst case is computed from the set_report command with a
485          * reportID > 15 and the maximum report length */
486         int args_len = sizeof(__u8) + /* optional ReportID byte */
487                        sizeof(__u16) + /* data register */
488                        sizeof(__u16) + /* size of the report */
489                        report_size; /* report */
490
491         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
492         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
493         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
494
495         if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
496                 i2c_hid_free_buffers(ihid);
497                 return -ENOMEM;
498         }
499
500         ihid->bufsize = report_size;
501
502         return 0;
503 }
504
505 static int i2c_hid_get_raw_report(struct hid_device *hid,
506                 unsigned char report_number, __u8 *buf, size_t count,
507                 unsigned char report_type)
508 {
509         struct i2c_client *client = hid->driver_data;
510         struct i2c_hid *ihid = i2c_get_clientdata(client);
511         size_t ret_count, ask_count;
512         int ret;
513
514         if (report_type == HID_OUTPUT_REPORT)
515                 return -EINVAL;
516
517         /* +2 bytes to include the size of the reply in the query buffer */
518         ask_count = min(count + 2, (size_t)ihid->bufsize);
519
520         ret = i2c_hid_get_report(client,
521                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
522                         report_number, ihid->inbuf, ask_count);
523
524         if (ret < 0)
525                 return ret;
526
527         ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
528
529         if (ret_count <= 2)
530                 return 0;
531
532         ret_count = min(ret_count, ask_count);
533
534         /* The query buffer contains the size, dropping it in the reply */
535         count = min(count, ret_count - 2);
536         memcpy(buf, ihid->inbuf + 2, count);
537
538         return count;
539 }
540
541 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
542                 size_t count, unsigned char report_type)
543 {
544         struct i2c_client *client = hid->driver_data;
545         int report_id = buf[0];
546
547         if (report_type == HID_INPUT_REPORT)
548                 return -EINVAL;
549
550         return i2c_hid_set_report(client,
551                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
552                                 report_id, buf, count);
553 }
554
555 static int i2c_hid_parse(struct hid_device *hid)
556 {
557         struct i2c_client *client = hid->driver_data;
558         struct i2c_hid *ihid = i2c_get_clientdata(client);
559         struct i2c_hid_desc *hdesc = &ihid->hdesc;
560         unsigned int rsize;
561         char *rdesc;
562         int ret;
563         int tries = 3;
564
565         i2c_hid_dbg(ihid, "entering %s\n", __func__);
566
567         rsize = le16_to_cpu(hdesc->wReportDescLength);
568         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
569                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
570                 return -EINVAL;
571         }
572
573         do {
574                 ret = i2c_hid_hwreset(client);
575                 if (ret)
576                         msleep(1000);
577         } while (tries-- > 0 && ret);
578
579         if (ret)
580                 return ret;
581
582         rdesc = kzalloc(rsize, GFP_KERNEL);
583
584         if (!rdesc) {
585                 dbg_hid("couldn't allocate rdesc memory\n");
586                 return -ENOMEM;
587         }
588
589         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
590
591         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
592         if (ret) {
593                 hid_err(hid, "reading report descriptor failed\n");
594                 kfree(rdesc);
595                 return -EIO;
596         }
597
598         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
599
600         ret = hid_parse_report(hid, rdesc, rsize);
601         kfree(rdesc);
602         if (ret) {
603                 dbg_hid("parsing report descriptor failed\n");
604                 return ret;
605         }
606
607         return 0;
608 }
609
610 static int i2c_hid_start(struct hid_device *hid)
611 {
612         struct i2c_client *client = hid->driver_data;
613         struct i2c_hid *ihid = i2c_get_clientdata(client);
614         int ret;
615         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
616
617         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
618         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
619         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
620
621         if (bufsize > ihid->bufsize) {
622                 i2c_hid_free_buffers(ihid);
623
624                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
625
626                 if (ret)
627                         return ret;
628         }
629
630         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
631                 i2c_hid_init_reports(hid);
632
633         return 0;
634 }
635
636 static void i2c_hid_stop(struct hid_device *hid)
637 {
638         struct i2c_client *client = hid->driver_data;
639         struct i2c_hid *ihid = i2c_get_clientdata(client);
640
641         hid->claimed = 0;
642
643         i2c_hid_free_buffers(ihid);
644 }
645
646 static int i2c_hid_open(struct hid_device *hid)
647 {
648         struct i2c_client *client = hid->driver_data;
649         struct i2c_hid *ihid = i2c_get_clientdata(client);
650         int ret = 0;
651
652         mutex_lock(&i2c_hid_open_mut);
653         if (!hid->open++) {
654                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
655                 if (ret) {
656                         hid->open--;
657                         goto done;
658                 }
659                 set_bit(I2C_HID_STARTED, &ihid->flags);
660         }
661 done:
662         mutex_unlock(&i2c_hid_open_mut);
663         return ret;
664 }
665
666 static void i2c_hid_close(struct hid_device *hid)
667 {
668         struct i2c_client *client = hid->driver_data;
669         struct i2c_hid *ihid = i2c_get_clientdata(client);
670
671         /* protecting hid->open to make sure we don't restart
672          * data acquistion due to a resumption we no longer
673          * care about
674          */
675         mutex_lock(&i2c_hid_open_mut);
676         if (!--hid->open) {
677                 clear_bit(I2C_HID_STARTED, &ihid->flags);
678
679                 /* Save some power */
680                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
681         }
682         mutex_unlock(&i2c_hid_open_mut);
683 }
684
685 static int i2c_hid_power(struct hid_device *hid, int lvl)
686 {
687         struct i2c_client *client = hid->driver_data;
688         struct i2c_hid *ihid = i2c_get_clientdata(client);
689         int ret = 0;
690
691         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
692
693         switch (lvl) {
694         case PM_HINT_FULLON:
695                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
696                 break;
697         case PM_HINT_NORMAL:
698                 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
699                 break;
700         }
701         return ret;
702 }
703
704 static int i2c_hid_hidinput_input_event(struct input_dev *dev,
705                 unsigned int type, unsigned int code, int value)
706 {
707         struct hid_device *hid = input_get_drvdata(dev);
708         struct hid_field *field;
709         int offset;
710
711         if (type == EV_FF)
712                 return input_ff_event(dev, type, code, value);
713
714         if (type != EV_LED)
715                 return -1;
716
717         offset = hidinput_find_field(hid, type, code, &field);
718
719         if (offset == -1) {
720                 hid_warn(dev, "event field not found\n");
721                 return -1;
722         }
723
724         return hid_set_field(field, offset, value);
725 }
726
727 static struct hid_ll_driver i2c_hid_ll_driver = {
728         .parse = i2c_hid_parse,
729         .start = i2c_hid_start,
730         .stop = i2c_hid_stop,
731         .open = i2c_hid_open,
732         .close = i2c_hid_close,
733         .power = i2c_hid_power,
734         .hidinput_input_event = i2c_hid_hidinput_input_event,
735 };
736
737 static int __devinit i2c_hid_init_irq(struct i2c_client *client)
738 {
739         struct i2c_hid *ihid = i2c_get_clientdata(client);
740         int ret;
741
742         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
743
744         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
745                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
746                         client->name, ihid);
747         if (ret < 0) {
748                 dev_warn(&client->dev,
749                         "Could not register for %s interrupt, irq = %d,"
750                         " ret = %d\n",
751                         client->name, client->irq, ret);
752
753                 return ret;
754         }
755
756         return 0;
757 }
758
759 static int __devinit i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
760 {
761         struct i2c_client *client = ihid->client;
762         struct i2c_hid_desc *hdesc = &ihid->hdesc;
763         unsigned int dsize;
764         int ret;
765
766         /* Fetch the length of HID description, retrieve the 4 first bytes:
767          * bytes 0-1 -> length
768          * bytes 2-3 -> bcdVersion (has to be 1.00) */
769         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
770
771         i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %*ph\n",
772                         __func__, 4, ihid->hdesc_buffer);
773
774         if (ret) {
775                 dev_err(&client->dev,
776                         "unable to fetch the size of HID descriptor (ret=%d)\n",
777                         ret);
778                 return -ENODEV;
779         }
780
781         dsize = le16_to_cpu(hdesc->wHIDDescLength);
782         /*
783          * the size of the HID descriptor should at least contain
784          * its size and the bcdVersion (4 bytes), and should not be greater
785          * than sizeof(struct i2c_hid_desc) as we directly fill this struct
786          * through i2c_hid_command.
787          */
788         if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
789                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
790                         dsize);
791                 return -ENODEV;
792         }
793
794         /* check bcdVersion == 1.0 */
795         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
796                 dev_err(&client->dev,
797                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
798                         le16_to_cpu(hdesc->bcdVersion));
799                 return -ENODEV;
800         }
801
802         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
803
804         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
805                                 dsize);
806         if (ret) {
807                 dev_err(&client->dev, "hid_descr_cmd Fail\n");
808                 return -ENODEV;
809         }
810
811         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
812
813         return 0;
814 }
815
816 #ifdef CONFIG_ACPI
817 static int i2c_hid_acpi_pdata(struct i2c_client *client,
818                 struct i2c_hid_platform_data *pdata)
819 {
820         static u8 i2c_hid_guid[] = {
821                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
822                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
823         };
824         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
825         union acpi_object params[4], *obj;
826         struct acpi_object_list input;
827         struct acpi_device *adev;
828         acpi_handle handle;
829
830         handle = ACPI_HANDLE(&client->dev);
831         if (!handle || acpi_bus_get_device(handle, &adev))
832                 return -ENODEV;
833
834         input.count = ARRAY_SIZE(params);
835         input.pointer = params;
836
837         params[0].type = ACPI_TYPE_BUFFER;
838         params[0].buffer.length = sizeof(i2c_hid_guid);
839         params[0].buffer.pointer = i2c_hid_guid;
840         params[1].type = ACPI_TYPE_INTEGER;
841         params[1].integer.value = 1;
842         params[2].type = ACPI_TYPE_INTEGER;
843         params[2].integer.value = 1; /* HID function */
844         params[3].type = ACPI_TYPE_INTEGER;
845         params[3].integer.value = 0;
846
847         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
848                 dev_err(&client->dev, "device _DSM execution failed\n");
849                 return -ENODEV;
850         }
851
852         obj = (union acpi_object *)buf.pointer;
853         if (obj->type != ACPI_TYPE_INTEGER) {
854                 dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
855                         obj->type);
856                 kfree(buf.pointer);
857                 return -EINVAL;
858         }
859
860         pdata->hid_descriptor_address = obj->integer.value;
861
862         kfree(buf.pointer);
863         return 0;
864 }
865
866 static const struct acpi_device_id i2c_hid_acpi_match[] = {
867         {"ACPI0C50", 0 },
868         {"PNP0C50", 0 },
869         { },
870 };
871 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
872 #else
873 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
874                 struct i2c_hid_platform_data *pdata)
875 {
876         return -ENODEV;
877 }
878 #endif
879
880 static int __devinit i2c_hid_probe(struct i2c_client *client,
881                 const struct i2c_device_id *dev_id)
882 {
883         int ret;
884         struct i2c_hid *ihid;
885         struct hid_device *hid;
886         __u16 hidRegister;
887         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
888
889         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
890
891         if (!client->irq) {
892                 dev_err(&client->dev,
893                         "HID over i2c has not been provided an Int IRQ\n");
894                 return -EINVAL;
895         }
896
897         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
898         if (!ihid)
899                 return -ENOMEM;
900
901         if (!platform_data) {
902                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
903                 if (ret) {
904                         dev_err(&client->dev,
905                                 "HID register address not provided\n");
906                         goto err;
907                 }
908         } else {
909                 ihid->pdata = *platform_data;
910         }
911
912         i2c_set_clientdata(client, ihid);
913
914         ihid->client = client;
915
916         hidRegister = ihid->pdata.hid_descriptor_address;
917         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
918
919         init_waitqueue_head(&ihid->wait);
920
921         /* we need to allocate the command buffer without knowing the maximum
922          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
923          * real computation later. */
924         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
925         if (ret < 0)
926                 goto err;
927
928         ret = i2c_hid_fetch_hid_descriptor(ihid);
929         if (ret < 0)
930                 goto err;
931
932         ret = i2c_hid_init_irq(client);
933         if (ret < 0)
934                 goto err;
935
936         hid = hid_allocate_device();
937         if (IS_ERR(hid)) {
938                 ret = PTR_ERR(hid);
939                 goto err_irq;
940         }
941
942         ihid->hid = hid;
943
944         hid->driver_data = client;
945         hid->ll_driver = &i2c_hid_ll_driver;
946         hid->hid_get_raw_report = i2c_hid_get_raw_report;
947         hid->hid_output_raw_report = i2c_hid_output_raw_report;
948         hid->dev.parent = &client->dev;
949         ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
950         hid->bus = BUS_I2C;
951         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
952         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
953         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
954
955         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
956                  client->name, hid->vendor, hid->product);
957
958         ret = hid_add_device(hid);
959         if (ret) {
960                 if (ret != -ENODEV)
961                         hid_err(client, "can't add hid device: %d\n", ret);
962                 goto err_mem_free;
963         }
964
965         return 0;
966
967 err_mem_free:
968         hid_destroy_device(hid);
969
970 err_irq:
971         free_irq(client->irq, ihid);
972
973 err:
974         i2c_hid_free_buffers(ihid);
975         kfree(ihid);
976         return ret;
977 }
978
979 static int __devexit i2c_hid_remove(struct i2c_client *client)
980 {
981         struct i2c_hid *ihid = i2c_get_clientdata(client);
982         struct hid_device *hid;
983
984         hid = ihid->hid;
985         hid_destroy_device(hid);
986
987         free_irq(client->irq, ihid);
988
989         if (ihid->bufsize)
990                 i2c_hid_free_buffers(ihid);
991
992         kfree(ihid);
993
994         return 0;
995 }
996
997 #ifdef CONFIG_PM_SLEEP
998 static int i2c_hid_suspend(struct device *dev)
999 {
1000         struct i2c_client *client = to_i2c_client(dev);
1001
1002         if (device_may_wakeup(&client->dev))
1003                 enable_irq_wake(client->irq);
1004
1005         /* Save some power */
1006         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1007
1008         return 0;
1009 }
1010
1011 static int i2c_hid_resume(struct device *dev)
1012 {
1013         int ret;
1014         struct i2c_client *client = to_i2c_client(dev);
1015
1016         ret = i2c_hid_hwreset(client);
1017         if (ret)
1018                 return ret;
1019
1020         if (device_may_wakeup(&client->dev))
1021                 disable_irq_wake(client->irq);
1022
1023         return 0;
1024 }
1025 #endif
1026
1027 static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
1028
1029 static const struct i2c_device_id i2c_hid_id_table[] = {
1030         { "hid", 0 },
1031         { },
1032 };
1033 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1034
1035
1036 static struct i2c_driver i2c_hid_driver = {
1037         .driver = {
1038                 .name   = "i2c_hid",
1039                 .owner  = THIS_MODULE,
1040                 .pm     = &i2c_hid_pm,
1041                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1042         },
1043
1044         .probe          = i2c_hid_probe,
1045         .remove         = __devexit_p(i2c_hid_remove),
1046
1047         .id_table       = i2c_hid_id_table,
1048 };
1049
1050 module_i2c_driver(i2c_hid_driver);
1051
1052 MODULE_DESCRIPTION("HID over I2C core driver");
1053 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1054 MODULE_LICENSE("GPL");