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HID: i2c-hid: introduce HID over i2c specification implementation
[mirror_ubuntu-bionic-kernel.git] / drivers / hid / i2c-hid / i2c-hid.c
CommitLineData
4a200c3b
BT		 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/bug.h>
36#include <linux/hid.h>
37
38#include <linux/i2c/i2c-hid.h>
39
40/* flags */
41#define I2C_HID_STARTED (1 << 0)
42#define I2C_HID_RESET_PENDING (1 << 1)
43#define I2C_HID_READ_PENDING (1 << 2)
44
45#define I2C_HID_PWR_ON 0x00
46#define I2C_HID_PWR_SLEEP 0x01
47
48/* debug option */
49static bool debug = false;
50module_param(debug, bool, 0444);
51MODULE_PARM_DESC(debug, "print a lot of debug information");
52
53#define i2c_hid_dbg(ihid, fmt, arg...) \
54 if (debug) \
55 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg)
56
57struct i2c_hid_desc {
58 __le16 wHIDDescLength;
59 __le16 bcdVersion;
60 __le16 wReportDescLength;
61 __le16 wReportDescRegister;
62 __le16 wInputRegister;
63 __le16 wMaxInputLength;
64 __le16 wOutputRegister;
65 __le16 wMaxOutputLength;
66 __le16 wCommandRegister;
67 __le16 wDataRegister;
68 __le16 wVendorID;
69 __le16 wProductID;
70 __le16 wVersionID;
71} __packed;
72
73struct i2c_hid_cmd {
74 unsigned int registerIndex;
75 __u8 opcode;
76 unsigned int length;
77 bool wait;
78};
79
80union command {
81 u8 data[0];
82 struct cmd {
83 __le16 reg;
84 __u8 reportTypeID;
85 __u8 opcode;
86 } __packed c;
87};
88
89#define I2C_HID_CMD(opcode_) \
90 .opcode = opcode_, .length = 4, \
91 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
92
93/* fetch HID descriptor */
94static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
95/* fetch report descriptors */
96static const struct i2c_hid_cmd hid_report_descr_cmd = {
97 .registerIndex = offsetof(struct i2c_hid_desc,
98 wReportDescRegister),
99 .opcode = 0x00,
100 .length = 2 };
101/* commands */
102static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
103 .wait = true };
104static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
105static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) };
106static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
107static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
108static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
109static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
110static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
111/* read/write data register */
112static const struct i2c_hid_cmd hid_data_cmd = {
113 .registerIndex = offsetof(struct i2c_hid_desc, wDataRegister),
114 .opcode = 0x00,
115 .length = 2 };
116/* write output reports */
117static const struct i2c_hid_cmd hid_out_cmd = {
118 .registerIndex = offsetof(struct i2c_hid_desc,
119 wOutputRegister),
120 .opcode = 0x00,
121 .length = 2 };
122
123/* The main device structure */
124struct i2c_hid {
125 struct i2c_client *client; /* i2c client */
126 struct hid_device *hid; /* pointer to corresponding HID dev */
127 union {
128 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
129 struct i2c_hid_desc hdesc; /* the HID Descriptor */
130 };
131 __le16 wHIDDescRegister; /* location of the i2c
132 * register of the HID
133 * descriptor. */
134 unsigned int bufsize; /* i2c buffer size */
135 char *inbuf; /* Input buffer */
136 char *cmdbuf; /* Command buffer */
137 char *argsbuf; /* Command arguments buffer */
138
139 unsigned long flags; /* device flags */
140
141 int irq; /* the interrupt line irq */
142
143 wait_queue_head_t wait; /* For waiting the interrupt */
144};
145
146static int __i2c_hid_command(struct i2c_client *client,
147 const struct i2c_hid_cmd *command, u8 reportID,
148 u8 reportType, u8 *args, int args_len,
149 unsigned char *buf_recv, int data_len)
150{
151 struct i2c_hid *ihid = i2c_get_clientdata(client);
152 union command *cmd = (union command *)ihid->cmdbuf;
153 int ret;
154 struct i2c_msg msg[2];
155 int msg_num = 1;
156
157 int length = command->length;
158 bool wait = command->wait;
159 unsigned int registerIndex = command->registerIndex;
160
161 /* special case for hid_descr_cmd */
162 if (command == &hid_descr_cmd) {
163 cmd->c.reg = ihid->wHIDDescRegister;
164 } else {
165 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
166 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
167 }
168
169 if (length > 2) {
170 cmd->c.opcode = command->opcode;
171 cmd->c.reportTypeID = reportID | reportType << 4;
172 }
173
174 memcpy(cmd->data + length, args, args_len);
175 length += args_len;
176
177 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
178
179 msg[0].addr = client->addr;
180 msg[0].flags = client->flags & I2C_M_TEN;
181 msg[0].len = length;
182 msg[0].buf = cmd->data;
183 if (data_len > 0) {
184 msg[1].addr = client->addr;
185 msg[1].flags = client->flags & I2C_M_TEN;
186 msg[1].flags |= I2C_M_RD;
187 msg[1].len = data_len;
188 msg[1].buf = buf_recv;
189 msg_num = 2;
190 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
191 }
192
193 if (wait)
194 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
195
196 ret = i2c_transfer(client->adapter, msg, msg_num);
197
198 if (data_len > 0)
199 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
200
201 if (ret != msg_num)
202 return ret < 0 ? ret : -EIO;
203
204 ret = 0;
205
206 if (wait) {
207 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
208 if (!wait_event_timeout(ihid->wait,
209 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
210 msecs_to_jiffies(5000)))
211 ret = -ENODATA;
212 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
213 }
214
215 return ret;
216}
217
218static int i2c_hid_command(struct i2c_client *client,
219 const struct i2c_hid_cmd *command,
220 unsigned char *buf_recv, int data_len)
221{
222 return __i2c_hid_command(client, command, 0, 0, NULL, 0,
223 buf_recv, data_len);
224}
225
226static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
227 u8 reportID, unsigned char *buf_recv, int data_len)
228{
229 struct i2c_hid *ihid = i2c_get_clientdata(client);
230 u8 args[3];
231 int ret;
232 int args_len = 0;
233 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
234
235 i2c_hid_dbg(ihid, "%s\n", __func__);
236
237 if (reportID >= 0x0F) {
238 args[args_len++] = reportID;
239 reportID = 0x0F;
240 }
241
242 args[args_len++] = readRegister & 0xFF;
243 args[args_len++] = readRegister >> 8;
244
245 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
246 reportType, args, args_len, buf_recv, data_len);
247 if (ret) {
248 dev_err(&client->dev,
249 "failed to retrieve report from device.\n");
250 return -EINVAL;
251 }
252
253 return 0;
254}
255
256static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
257 u8 reportID, unsigned char *buf, size_t data_len)
258{
259 struct i2c_hid *ihid = i2c_get_clientdata(client);
260 u8 *args = ihid->argsbuf;
261 int ret;
262 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
263
264 /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
265 u16 size = 2 /* size */ +
266 (reportID ? 1 : 0) /* reportID */ +
267 data_len /* buf */;
268 int args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
269 2 /* dataRegister */ +
270 size /* args */;
271 int index = 0;
272
273 i2c_hid_dbg(ihid, "%s\n", __func__);
274
275 if (reportID >= 0x0F) {
276 args[index++] = reportID;
277 reportID = 0x0F;
278 }
279
280 args[index++] = dataRegister & 0xFF;
281 args[index++] = dataRegister >> 8;
282
283 args[index++] = size & 0xFF;
284 args[index++] = size >> 8;
285
286 if (reportID)
287 args[index++] = reportID;
288
289 memcpy(&args[index], buf, data_len);
290
291 ret = __i2c_hid_command(client, &hid_set_report_cmd, reportID,
292 reportType, args, args_len, NULL, 0);
293 if (ret) {
294 dev_err(&client->dev, "failed to set a report to device.\n");
295 return -EINVAL;
296 }
297
298 return data_len;
299}
300
301static int i2c_hid_set_power(struct i2c_client *client, int power_state)
302{
303 struct i2c_hid *ihid = i2c_get_clientdata(client);
304 int ret;
305
306 i2c_hid_dbg(ihid, "%s\n", __func__);
307
308 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
309 0, NULL, 0, NULL, 0);
310 if (ret)
311 dev_err(&client->dev, "failed to change power setting.\n");
312
313 return ret;
314}
315
316static int i2c_hid_hwreset(struct i2c_client *client)
317{
318 struct i2c_hid *ihid = i2c_get_clientdata(client);
319 int ret;
320
321 i2c_hid_dbg(ihid, "%s\n", __func__);
322
323 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
324 if (ret)
325 return ret;
326
327 i2c_hid_dbg(ihid, "resetting...\n");
328
329 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
330 if (ret) {
331 dev_err(&client->dev, "failed to reset device.\n");
332 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
333 return ret;
334 }
335
336 return 0;
337}
338
339static int i2c_hid_get_input(struct i2c_hid *ihid)
340{
341 int ret, ret_size;
342 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
343
344 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
345 if (ret != size) {
346 if (ret < 0)
347 return ret;
348
349 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
350 __func__, ret, size);
351 return ret;
352 }
353
354 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
355
356 if (!ret_size) {
357 /* host or device initiated RESET completed */
358 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
359 wake_up(&ihid->wait);
360 return 0;
361 }
362
363 if (ret_size > size) {
364 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
365 __func__, size, ret_size);
366 return -EIO;
367 }
368
369 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
370
371 if (test_bit(I2C_HID_STARTED, &ihid->flags))
372 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
373 ret_size - 2, 1);
374
375 return 0;
376}
377
378static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
379{
380 struct i2c_hid *ihid = dev_id;
381
382 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
383 return IRQ_HANDLED;
384
385 i2c_hid_get_input(ihid);
386
387 return IRQ_HANDLED;
388}
389
390static int i2c_hid_get_report_length(struct hid_report *report)
391{
392 return ((report->size - 1) >> 3) + 1 +
393 report->device->report_enum[report->type].numbered + 2;
394}
395
396static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
397 size_t bufsize)
398{
399 struct hid_device *hid = report->device;
400 struct i2c_client *client = hid->driver_data;
401 struct i2c_hid *ihid = i2c_get_clientdata(client);
402 unsigned int size, ret_size;
403
404 size = i2c_hid_get_report_length(report);
405 i2c_hid_get_report(client,
406 report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
407 report->id, buffer, size);
408
409 i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
410
411 ret_size = buffer[0] | (buffer[1] << 8);
412
413 if (ret_size != size) {
414 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
415 __func__, size, ret_size);
416 return;
417 }
418
419 /* hid->driver_lock is held as we are in probe function,
420 * we just need to setup the input fields, so using
421 * hid_report_raw_event is safe. */
422 hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
423}
424
425/*
426 * Initialize all reports
427 */
428static void i2c_hid_init_reports(struct hid_device *hid)
429{
430 struct hid_report *report;
431 struct i2c_client *client = hid->driver_data;
432 struct i2c_hid *ihid = i2c_get_clientdata(client);
433 u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
434
435 if (!inbuf)
436 return;
437
438 list_for_each_entry(report,
439 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
440 i2c_hid_init_report(report, inbuf, ihid->bufsize);
441
442 list_for_each_entry(report,
443 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
444 i2c_hid_init_report(report, inbuf, ihid->bufsize);
445
446 kfree(inbuf);
447}
448
449/*
450 * Traverse the supplied list of reports and find the longest
451 */
452static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
453 unsigned int *max)
454{
455 struct hid_report *report;
456 unsigned int size;
457
458 /* We should not rely on wMaxInputLength, as some devices may set it to
459 * a wrong length. */
460 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
461 size = i2c_hid_get_report_length(report);
462 if (*max < size)
463 *max = size;
464 }
465}
466
467static int i2c_hid_alloc_buffers(struct i2c_hid *ihid)
468{
469 /* the worst case is computed from the set_report command with a
470 * reportID > 15 and the maximum report length */
471 int args_len = sizeof(__u8) + /* optional ReportID byte */
472 sizeof(__u16) + /* data register */
473 sizeof(__u16) + /* size of the report */
474 ihid->bufsize; /* report */
475
476 ihid->inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
477
478 if (!ihid->inbuf)
479 return -ENOMEM;
480
481 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
482
483 if (!ihid->argsbuf) {
484 kfree(ihid->inbuf);
485 return -ENOMEM;
486 }
487
488 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
489
490 if (!ihid->cmdbuf) {
491 kfree(ihid->inbuf);
492 kfree(ihid->argsbuf);
493 ihid->inbuf = NULL;
494 ihid->argsbuf = NULL;
495 return -ENOMEM;
496 }
497
498 return 0;
499}
500
501static void i2c_hid_free_buffers(struct i2c_hid *ihid)
502{
503 kfree(ihid->inbuf);
504 kfree(ihid->argsbuf);
505 kfree(ihid->cmdbuf);
506 ihid->inbuf = NULL;
507 ihid->cmdbuf = NULL;
508 ihid->argsbuf = NULL;
509}
510
511static int i2c_hid_get_raw_report(struct hid_device *hid,
512 unsigned char report_number, __u8 *buf, size_t count,
513 unsigned char report_type)
514{
515 struct i2c_client *client = hid->driver_data;
516 struct i2c_hid *ihid = i2c_get_clientdata(client);
517 int ret;
518
519 if (report_type == HID_OUTPUT_REPORT)
520 return -EINVAL;
521
522 if (count > ihid->bufsize)
523 count = ihid->bufsize;
524
525 ret = i2c_hid_get_report(client,
526 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
527 report_number, ihid->inbuf, count);
528
529 if (ret < 0)
530 return ret;
531
532 count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
533
534 memcpy(buf, ihid->inbuf + 2, count);
535
536 return count;
537}
538
539static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
540 size_t count, unsigned char report_type)
541{
542 struct i2c_client *client = hid->driver_data;
543 int report_id = buf[0];
544
545 if (report_type == HID_INPUT_REPORT)
546 return -EINVAL;
547
548 return i2c_hid_set_report(client,
549 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
550 report_id, buf, count);
551}
552
553static int i2c_hid_parse(struct hid_device *hid)
554{
555 struct i2c_client *client = hid->driver_data;
556 struct i2c_hid *ihid = i2c_get_clientdata(client);
557 struct i2c_hid_desc *hdesc = &ihid->hdesc;
558 unsigned int rsize;
559 char *rdesc;
560 int ret;
561 int tries = 3;
562
563 i2c_hid_dbg(ihid, "entering %s\n", __func__);
564
565 rsize = le16_to_cpu(hdesc->wReportDescLength);
566 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
567 dbg_hid("weird size of report descriptor (%u)\n", rsize);
568 return -EINVAL;
569 }
570
571 do {
572 ret = i2c_hid_hwreset(client);
573 if (ret)
574 msleep(1000);
575 } while (tries-- > 0 && ret);
576
577 if (ret)
578 return ret;
579
580 rdesc = kzalloc(rsize, GFP_KERNEL);
581
582 if (!rdesc) {
583 dbg_hid("couldn't allocate rdesc memory\n");
584 return -ENOMEM;
585 }
586
587 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
588
589 ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
590 if (ret) {
591 hid_err(hid, "reading report descriptor failed\n");
592 kfree(rdesc);
593 return -EIO;
594 }
595
596 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
597
598 ret = hid_parse_report(hid, rdesc, rsize);
599 kfree(rdesc);
600 if (ret) {
601 dbg_hid("parsing report descriptor failed\n");
602 return ret;
603 }
604
605 return 0;
606}
607
608static int i2c_hid_start(struct hid_device *hid)
609{
610 struct i2c_client *client = hid->driver_data;
611 struct i2c_hid *ihid = i2c_get_clientdata(client);
612 int ret;
613 int old_bufsize = ihid->bufsize;
614
615 ihid->bufsize = HID_MIN_BUFFER_SIZE;
616 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &ihid->bufsize);
617 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &ihid->bufsize);
618 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &ihid->bufsize);
619
620 if (ihid->bufsize > old_bufsize || !ihid->inbuf || !ihid->cmdbuf) {
621 i2c_hid_free_buffers(ihid);
622
623 ret = i2c_hid_alloc_buffers(ihid);
624
625 if (ret) {
626 ihid->bufsize = old_bufsize;
627 return ret;
628 }
629 }
630
631 if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
632 i2c_hid_init_reports(hid);
633
634 return 0;
635}
636
637static void i2c_hid_stop(struct hid_device *hid)
638{
639 struct i2c_client *client = hid->driver_data;
640 struct i2c_hid *ihid = i2c_get_clientdata(client);
641
642 hid->claimed = 0;
643
644 i2c_hid_free_buffers(ihid);
645}
646
647static int i2c_hid_open(struct hid_device *hid)
648{
649 struct i2c_client *client = hid->driver_data;
650 struct i2c_hid *ihid = i2c_get_clientdata(client);
651 int ret;
652
653 if (!hid->open++) {
654 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
655 if (ret) {
656 hid->open--;
657 return -EIO;
658 }
659 set_bit(I2C_HID_STARTED, &ihid->flags);
660 }
661 return 0;
662}
663
664static void i2c_hid_close(struct hid_device *hid)
665{
666 struct i2c_client *client = hid->driver_data;
667 struct i2c_hid *ihid = i2c_get_clientdata(client);
668
669 /* protecting hid->open to make sure we don't restart
670 * data acquistion due to a resumption we no longer
671 * care about
672 */
673 if (!--hid->open) {
674 clear_bit(I2C_HID_STARTED, &ihid->flags);
675
676 /* Save some power */
677 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
678 }
679}
680
681static int i2c_hid_power(struct hid_device *hid, int lvl)
682{
683 struct i2c_client *client = hid->driver_data;
684 struct i2c_hid *ihid = i2c_get_clientdata(client);
685 int ret = 0;
686
687 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
688
689 switch (lvl) {
690 case PM_HINT_FULLON:
691 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
692 break;
693 case PM_HINT_NORMAL:
694 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
695 break;
696 }
697 return ret;
698}
699
700static int i2c_hid_hidinput_input_event(struct input_dev *dev,
701 unsigned int type, unsigned int code, int value)
702{
703 struct hid_device *hid = input_get_drvdata(dev);
704 struct hid_field *field;
705 int offset;
706
707 if (type == EV_FF)
708 return input_ff_event(dev, type, code, value);
709
710 if (type != EV_LED)
711 return -1;
712
713 offset = hidinput_find_field(hid, type, code, &field);
714
715 if (offset == -1) {
716 hid_warn(dev, "event field not found\n");
717 return -1;
718 }
719
720 hid_set_field(field, offset, value);
721
722 return 0;
723}
724
725static struct hid_ll_driver i2c_hid_ll_driver = {
726 .parse = i2c_hid_parse,
727 .start = i2c_hid_start,
728 .stop = i2c_hid_stop,
729 .open = i2c_hid_open,
730 .close = i2c_hid_close,
731 .power = i2c_hid_power,
732 .hidinput_input_event = i2c_hid_hidinput_input_event,
733};
734
735static int __devinit i2c_hid_init_irq(struct i2c_client *client)
736{
737 struct i2c_hid *ihid = i2c_get_clientdata(client);
738 int ret;
739
740 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
741
742 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
743 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
744 client->name, ihid);
745 if (ret < 0) {
746 dev_dbg(&client->dev,
747 "Could not register for %s interrupt, irq = %d,"
748 " ret = %d\n",
749 client->name, client->irq, ret);
750
751 return ret;
752 }
753
754 ihid->irq = client->irq;
755
756 return 0;
757}
758
759static 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, "HID_DESCR_LENGTH_CMD Fail (ret=%d)\n",
776 ret);
777 return -ENODEV;
778 }
779
780 dsize = le16_to_cpu(hdesc->wHIDDescLength);
781 if (!dsize || dsize > HID_MAX_DESCRIPTOR_SIZE) {
782 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
783 dsize);
784 return -ENODEV;
785 }
786
787 /* check bcdVersion == 1.0 */
788 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
789 dev_err(&client->dev,
790 "unexpected HID descriptor bcdVersion (0x%04x)\n",
791 le16_to_cpu(hdesc->bcdVersion));
792 return -ENODEV;
793 }
794
795 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
796
797 ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
798 dsize);
799 if (ret) {
800 dev_err(&client->dev, "hid_descr_cmd Fail\n");
801 return -ENODEV;
802 }
803
804 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
805
806 return 0;
807}
808
809static int __devinit i2c_hid_probe(struct i2c_client *client,
810 const struct i2c_device_id *dev_id)
811{
812 int ret;
813 struct i2c_hid *ihid;
814 struct hid_device *hid;
815 __u16 hidRegister;
816 struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
817
818 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
819
820 if (!platform_data) {
821 dev_err(&client->dev, "HID register address not provided\n");
822 return -EINVAL;
823 }
824
825 if (!client->irq) {
826 dev_err(&client->dev,
827 "HID over i2c has not been provided an Int IRQ\n");
828 return -EINVAL;
829 }
830
831 ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
832 if (!ihid)
833 return -ENOMEM;
834
835 i2c_set_clientdata(client, ihid);
836
837 ihid->client = client;
838
839 hidRegister = platform_data->hid_descriptor_address;
840 ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
841
842 init_waitqueue_head(&ihid->wait);
843
844 /* we need to allocate the command buffer without knowing the maximum
845 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
846 * real computation later. */
847 ihid->bufsize = HID_MIN_BUFFER_SIZE;
848 i2c_hid_alloc_buffers(ihid);
849
850 ret = i2c_hid_fetch_hid_descriptor(ihid);
851 if (ret < 0)
852 goto err;
853
854 ret = i2c_hid_init_irq(client);
855 if (ret < 0)
856 goto err;
857
858 hid = hid_allocate_device();
859 if (IS_ERR(hid)) {
860 ret = PTR_ERR(hid);
861 goto err;
862 }
863
864 ihid->hid = hid;
865
866 hid->driver_data = client;
867 hid->ll_driver = &i2c_hid_ll_driver;
868 hid->hid_get_raw_report = i2c_hid_get_raw_report;
869 hid->hid_output_raw_report = i2c_hid_output_raw_report;
870 hid->dev.parent = &client->dev;
871 hid->bus = BUS_I2C;
872 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
873 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
874 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
875
876 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
877 client->name, hid->vendor, hid->product);
878
879 ret = hid_add_device(hid);
880 if (ret) {
881 if (ret != -ENODEV)
882 hid_err(client, "can't add hid device: %d\n", ret);
883 goto err_mem_free;
884 }
885
886 return 0;
887
888err_mem_free:
889 hid_destroy_device(hid);
890
891err:
892 if (ihid->irq)
893 free_irq(ihid->irq, ihid);
894
895 kfree(ihid);
896 return ret;
897}
898
899static int __devexit i2c_hid_remove(struct i2c_client *client)
900{
901 struct i2c_hid *ihid = i2c_get_clientdata(client);
902 struct hid_device *hid;
903
904 if (WARN_ON(!ihid))
905 return -1;
906
907 hid = ihid->hid;
908 hid_destroy_device(hid);
909
910 free_irq(client->irq, ihid);
911
912 kfree(ihid);
913
914 return 0;
915}
916
917#ifdef CONFIG_PM_SLEEP
918static int i2c_hid_suspend(struct device *dev)
919{
920 struct i2c_client *client = to_i2c_client(dev);
921 struct i2c_hid *ihid = i2c_get_clientdata(client);
922
923 if (device_may_wakeup(&client->dev))
924 enable_irq_wake(ihid->irq);
925
926 /* Save some power */
927 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
928
929 return 0;
930}
931
932static int i2c_hid_resume(struct device *dev)
933{
934 int ret;
935 struct i2c_client *client = to_i2c_client(dev);
936
937 ret = i2c_hid_hwreset(client);
938 if (ret)
939 return ret;
940
941 if (device_may_wakeup(&client->dev))
942 disable_irq_wake(client->irq);
943
944 return 0;
945}
946#endif
947
948static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
949
950static const struct i2c_device_id i2c_hid_id_table[] = {
951 { "i2c_hid", 0 },
952 { },
953};
954MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
955
956
957static struct i2c_driver i2c_hid_driver = {
958 .driver = {
959 .name = "i2c_hid",
960 .owner = THIS_MODULE,
961 .pm = &i2c_hid_pm,
962 },
963
964 .probe = i2c_hid_probe,
965 .remove = __devexit_p(i2c_hid_remove),
966
967 .id_table = i2c_hid_id_table,
968};
969
970module_i2c_driver(i2c_hid_driver);
971
972MODULE_DESCRIPTION("HID over I2C core driver");
973MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
974MODULE_LICENSE("GPL");
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