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x86/xen: resume timer irqs early
[linux/fpc-iii.git] / drivers / hid / i2c-hid / i2c-hid.c
blobc1336193b04ba3deb92c3edf2468551f3f6933a9
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 #include <linux/of.h>
39
40 #include <linux/i2c/i2c-hid.h>
41
42 /* flags */
43 #define I2C_HID_STARTED (1 << 0)
44 #define I2C_HID_RESET_PENDING (1 << 1)
45 #define I2C_HID_READ_PENDING (1 << 2)
46
47 #define I2C_HID_PWR_ON 0x00
48 #define I2C_HID_PWR_SLEEP 0x01
49
50 /* debug option */
51 static bool debug;
52 module_param(debug, bool, 0444);
53 MODULE_PARM_DESC(debug, "print a lot of debug information");
54
55 #define i2c_hid_dbg(ihid, fmt, arg...) \
56 do { \
57 if (debug) \
58 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
59 } while (0)
60
61 struct i2c_hid_desc {
62 __le16 wHIDDescLength;
63 __le16 bcdVersion;
64 __le16 wReportDescLength;
65 __le16 wReportDescRegister;
66 __le16 wInputRegister;
67 __le16 wMaxInputLength;
68 __le16 wOutputRegister;
69 __le16 wMaxOutputLength;
70 __le16 wCommandRegister;
71 __le16 wDataRegister;
72 __le16 wVendorID;
73 __le16 wProductID;
74 __le16 wVersionID;
75 __le32 reserved;
76 } __packed;
77
78 struct i2c_hid_cmd {
79 unsigned int registerIndex;
80 __u8 opcode;
81 unsigned int length;
82 bool wait;
83 };
84
85 union command {
86 u8 data[0];
87 struct cmd {
88 __le16 reg;
89 __u8 reportTypeID;
90 __u8 opcode;
91 } __packed c;
92 };
93
94 #define I2C_HID_CMD(opcode_) \
95 .opcode = opcode_, .length = 4, \
96 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
97
98 /* fetch HID descriptor */
99 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
100 /* fetch report descriptors */
101 static const struct i2c_hid_cmd hid_report_descr_cmd = {
102 .registerIndex = offsetof(struct i2c_hid_desc,
103 wReportDescRegister),
104 .opcode = 0x00,
105 .length = 2 };
106 /* commands */
107 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
108 .wait = true };
109 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
110 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) };
111 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
112 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 };
113
114 /*
115 * These definitions are not used here, but are defined by the spec.
116 * Keeping them here for documentation purposes.
117 *
118 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
119 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
120 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
121 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
122 */
123
124 static DEFINE_MUTEX(i2c_hid_open_mut);
125
126 /* The main device structure */
127 struct i2c_hid {
128 struct i2c_client *client; /* i2c client */
129 struct hid_device *hid; /* pointer to corresponding HID dev */
130 union {
131 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
132 struct i2c_hid_desc hdesc; /* the HID Descriptor */
133 };
134 __le16 wHIDDescRegister; /* location of the i2c
135 * register of the HID
136 * descriptor. */
137 unsigned int bufsize; /* i2c buffer size */
138 char *inbuf; /* Input buffer */
139 char *cmdbuf; /* Command buffer */
140 char *argsbuf; /* Command arguments buffer */
141
142 unsigned long flags; /* device flags */
143
144 wait_queue_head_t wait; /* For waiting the interrupt */
145
146 struct i2c_hid_platform_data pdata;
147 };
148
149 static int __i2c_hid_command(struct i2c_client *client,
150 const struct i2c_hid_cmd *command, u8 reportID,
151 u8 reportType, u8 *args, int args_len,
152 unsigned char *buf_recv, int data_len)
153 {
154 struct i2c_hid *ihid = i2c_get_clientdata(client);
155 union command *cmd = (union command *)ihid->cmdbuf;
156 int ret;
157 struct i2c_msg msg[2];
158 int msg_num = 1;
159
160 int length = command->length;
161 bool wait = command->wait;
162 unsigned int registerIndex = command->registerIndex;
163
164 /* special case for hid_descr_cmd */
165 if (command == &hid_descr_cmd) {
166 cmd->c.reg = ihid->wHIDDescRegister;
167 } else {
168 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
169 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
170 }
171
172 if (length > 2) {
173 cmd->c.opcode = command->opcode;
174 cmd->c.reportTypeID = reportID | reportType << 4;
175 }
176
177 memcpy(cmd->data + length, args, args_len);
178 length += args_len;
179
180 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
181
182 msg[0].addr = client->addr;
183 msg[0].flags = client->flags & I2C_M_TEN;
184 msg[0].len = length;
185 msg[0].buf = cmd->data;
186 if (data_len > 0) {
187 msg[1].addr = client->addr;
188 msg[1].flags = client->flags & I2C_M_TEN;
189 msg[1].flags |= I2C_M_RD;
190 msg[1].len = data_len;
191 msg[1].buf = buf_recv;
192 msg_num = 2;
193 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
194 }
195
196 if (wait)
197 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
198
199 ret = i2c_transfer(client->adapter, msg, msg_num);
200
201 if (data_len > 0)
202 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
203
204 if (ret != msg_num)
205 return ret < 0 ? ret : -EIO;
206
207 ret = 0;
208
209 if (wait) {
210 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
211 if (!wait_event_timeout(ihid->wait,
212 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
213 msecs_to_jiffies(5000)))
214 ret = -ENODATA;
215 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
216 }
217
218 return ret;
219 }
220
221 static int i2c_hid_command(struct i2c_client *client,
222 const struct i2c_hid_cmd *command,
223 unsigned char *buf_recv, int data_len)
224 {
225 return __i2c_hid_command(client, command, 0, 0, NULL, 0,
226 buf_recv, data_len);
227 }
228
229 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
230 u8 reportID, unsigned char *buf_recv, int data_len)
231 {
232 struct i2c_hid *ihid = i2c_get_clientdata(client);
233 u8 args[3];
234 int ret;
235 int args_len = 0;
236 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
237
238 i2c_hid_dbg(ihid, "%s\n", __func__);
239
240 if (reportID >= 0x0F) {
241 args[args_len++] = reportID;
242 reportID = 0x0F;
243 }
244
245 args[args_len++] = readRegister & 0xFF;
246 args[args_len++] = readRegister >> 8;
247
248 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
249 reportType, args, args_len, buf_recv, data_len);
250 if (ret) {
251 dev_err(&client->dev,
252 "failed to retrieve report from device.\n");
253 return ret;
254 }
255
256 return 0;
257 }
258
259 static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
260 u8 reportID, unsigned char *buf, size_t data_len)
261 {
262 struct i2c_hid *ihid = i2c_get_clientdata(client);
263 u8 *args = ihid->argsbuf;
264 const struct i2c_hid_cmd * hidcmd = &hid_set_report_cmd;
265 int ret;
266 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
267 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
268 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
269
270 /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
271 u16 size = 2 /* size */ +
272 (reportID ? 1 : 0) /* reportID */ +
273 data_len /* buf */;
274 int args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
275 2 /* dataRegister */ +
276 size /* args */;
277 int index = 0;
278
279 i2c_hid_dbg(ihid, "%s\n", __func__);
280
281 if (reportID >= 0x0F) {
282 args[index++] = reportID;
283 reportID = 0x0F;
284 }
285
286 /*
287 * use the data register for feature reports or if the device does not
288 * support the output register
289 */
290 if (reportType == 0x03 || maxOutputLength == 0) {
291 args[index++] = dataRegister & 0xFF;
292 args[index++] = dataRegister >> 8;
293 } else {
294 args[index++] = outputRegister & 0xFF;
295 args[index++] = outputRegister >> 8;
296 hidcmd = &hid_no_cmd;
297 }
298
299 args[index++] = size & 0xFF;
300 args[index++] = size >> 8;
301
302 if (reportID)
303 args[index++] = reportID;
304
305 memcpy(&args[index], buf, data_len);
306
307 ret = __i2c_hid_command(client, hidcmd, reportID,
308 reportType, args, args_len, NULL, 0);
309 if (ret) {
310 dev_err(&client->dev, "failed to set a report to device.\n");
311 return ret;
312 }
313
314 return data_len;
315 }
316
317 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
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_command(client, &hid_set_power_cmd, power_state,
325 0, NULL, 0, NULL, 0);
326 if (ret)
327 dev_err(&client->dev, "failed to change power setting.\n");
328
329 return ret;
330 }
331
332 static int i2c_hid_hwreset(struct i2c_client *client)
333 {
334 struct i2c_hid *ihid = i2c_get_clientdata(client);
335 int ret;
336
337 i2c_hid_dbg(ihid, "%s\n", __func__);
338
339 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
340 if (ret)
341 return ret;
342
343 i2c_hid_dbg(ihid, "resetting...\n");
344
345 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
346 if (ret) {
347 dev_err(&client->dev, "failed to reset device.\n");
348 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
349 return ret;
350 }
351
352 return 0;
353 }
354
355 static void i2c_hid_get_input(struct i2c_hid *ihid)
356 {
357 int ret, ret_size;
358 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
359
360 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
361 if (ret != size) {
362 if (ret < 0)
363 return;
364
365 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
366 __func__, ret, size);
367 return;
368 }
369
370 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
371
372 if (!ret_size) {
373 /* host or device initiated RESET completed */
374 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
375 wake_up(&ihid->wait);
376 return;
377 }
378
379 if (ret_size > size) {
380 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
381 __func__, size, ret_size);
382 return;
383 }
384
385 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
386
387 if (test_bit(I2C_HID_STARTED, &ihid->flags))
388 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
389 ret_size - 2, 1);
390
391 return;
392 }
393
394 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
395 {
396 struct i2c_hid *ihid = dev_id;
397
398 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
399 return IRQ_HANDLED;
400
401 i2c_hid_get_input(ihid);
402
403 return IRQ_HANDLED;
404 }
405
406 static int i2c_hid_get_report_length(struct hid_report *report)
407 {
408 return ((report->size - 1) >> 3) + 1 +
409 report->device->report_enum[report->type].numbered + 2;
410 }
411
412 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
413 size_t bufsize)
414 {
415 struct hid_device *hid = report->device;
416 struct i2c_client *client = hid->driver_data;
417 struct i2c_hid *ihid = i2c_get_clientdata(client);
418 unsigned int size, ret_size;
419
420 size = i2c_hid_get_report_length(report);
421 if (i2c_hid_get_report(client,
422 report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
423 report->id, buffer, size))
424 return;
425
426 i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
427
428 ret_size = buffer[0] | (buffer[1] << 8);
429
430 if (ret_size != size) {
431 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
432 __func__, size, ret_size);
433 return;
434 }
435
436 /* hid->driver_lock is held as we are in probe function,
437 * we just need to setup the input fields, so using
438 * hid_report_raw_event is safe. */
439 hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
440 }
441
442 /*
443 * Initialize all reports
444 */
445 static void i2c_hid_init_reports(struct hid_device *hid)
446 {
447 struct hid_report *report;
448 struct i2c_client *client = hid->driver_data;
449 struct i2c_hid *ihid = i2c_get_clientdata(client);
450 u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
451
452 if (!inbuf) {
453 dev_err(&client->dev, "can not retrieve initial reports\n");
454 return;
455 }
456
457 list_for_each_entry(report,
458 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
459 i2c_hid_init_report(report, inbuf, ihid->bufsize);
460
461 list_for_each_entry(report,
462 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
463 i2c_hid_init_report(report, inbuf, ihid->bufsize);
464
465 kfree(inbuf);
466 }
467
468 /*
469 * Traverse the supplied list of reports and find the longest
470 */
471 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
472 unsigned int *max)
473 {
474 struct hid_report *report;
475 unsigned int size;
476
477 /* We should not rely on wMaxInputLength, as some devices may set it to
478 * a wrong length. */
479 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
480 size = i2c_hid_get_report_length(report);
481 if (*max < size)
482 *max = size;
483 }
484 }
485
486 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
487 {
488 kfree(ihid->inbuf);
489 kfree(ihid->argsbuf);
490 kfree(ihid->cmdbuf);
491 ihid->inbuf = NULL;
492 ihid->cmdbuf = NULL;
493 ihid->argsbuf = NULL;
494 ihid->bufsize = 0;
495 }
496
497 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
498 {
499 /* the worst case is computed from the set_report command with a
500 * reportID > 15 and the maximum report length */
501 int args_len = sizeof(__u8) + /* optional ReportID byte */
502 sizeof(__u16) + /* data register */
503 sizeof(__u16) + /* size of the report */
504 report_size; /* report */
505
506 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
507 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
508 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
509
510 if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
511 i2c_hid_free_buffers(ihid);
512 return -ENOMEM;
513 }
514
515 ihid->bufsize = report_size;
516
517 return 0;
518 }
519
520 static int i2c_hid_get_raw_report(struct hid_device *hid,
521 unsigned char report_number, __u8 *buf, size_t count,
522 unsigned char report_type)
523 {
524 struct i2c_client *client = hid->driver_data;
525 struct i2c_hid *ihid = i2c_get_clientdata(client);
526 size_t ret_count, ask_count;
527 int ret;
528
529 if (report_type == HID_OUTPUT_REPORT)
530 return -EINVAL;
531
532 /* +2 bytes to include the size of the reply in the query buffer */
533 ask_count = min(count + 2, (size_t)ihid->bufsize);
534
535 ret = i2c_hid_get_report(client,
536 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
537 report_number, ihid->inbuf, ask_count);
538
539 if (ret < 0)
540 return ret;
541
542 ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
543
544 if (ret_count <= 2)
545 return 0;
546
547 ret_count = min(ret_count, ask_count);
548
549 /* The query buffer contains the size, dropping it in the reply */
550 count = min(count, ret_count - 2);
551 memcpy(buf, ihid->inbuf + 2, count);
552
553 return count;
554 }
555
556 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
557 size_t count, unsigned char report_type)
558 {
559 struct i2c_client *client = hid->driver_data;
560 int report_id = buf[0];
561 int ret;
562
563 if (report_type == HID_INPUT_REPORT)
564 return -EINVAL;
565
566 if (report_id) {
567 buf++;
568 count--;
569 }
570
571 ret = i2c_hid_set_report(client,
572 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
573 report_id, buf, count);
574
575 if (report_id && ret >= 0)
576 ret++; /* add report_id to the number of transfered bytes */
577
578 return ret;
579 }
580
581 static void i2c_hid_request(struct hid_device *hid, struct hid_report *rep,
582 int reqtype)
583 {
584 struct i2c_client *client = hid->driver_data;
585 char *buf;
586 int ret;
587 int len = i2c_hid_get_report_length(rep) - 2;
588
589 buf = kzalloc(len, GFP_KERNEL);
590 if (!buf)
591 return;
592
593 switch (reqtype) {
594 case HID_REQ_GET_REPORT:
595 ret = i2c_hid_get_raw_report(hid, rep->id, buf, len, rep->type);
596 if (ret < 0)
597 dev_err(&client->dev, "%s: unable to get report: %d\n",
598 __func__, ret);
599 else
600 hid_input_report(hid, rep->type, buf, ret, 0);
601 break;
602 case HID_REQ_SET_REPORT:
603 hid_output_report(rep, buf);
604 i2c_hid_output_raw_report(hid, buf, len, rep->type);
605 break;
606 }
607
608 kfree(buf);
609 }
610
611 static int i2c_hid_parse(struct hid_device *hid)
612 {
613 struct i2c_client *client = hid->driver_data;
614 struct i2c_hid *ihid = i2c_get_clientdata(client);
615 struct i2c_hid_desc *hdesc = &ihid->hdesc;
616 unsigned int rsize;
617 char *rdesc;
618 int ret;
619 int tries = 3;
620
621 i2c_hid_dbg(ihid, "entering %s\n", __func__);
622
623 rsize = le16_to_cpu(hdesc->wReportDescLength);
624 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
625 dbg_hid("weird size of report descriptor (%u)\n", rsize);
626 return -EINVAL;
627 }
628
629 do {
630 ret = i2c_hid_hwreset(client);
631 if (ret)
632 msleep(1000);
633 } while (tries-- > 0 && ret);
634
635 if (ret)
636 return ret;
637
638 rdesc = kzalloc(rsize, GFP_KERNEL);
639
640 if (!rdesc) {
641 dbg_hid("couldn't allocate rdesc memory\n");
642 return -ENOMEM;
643 }
644
645 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
646
647 ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
648 if (ret) {
649 hid_err(hid, "reading report descriptor failed\n");
650 kfree(rdesc);
651 return -EIO;
652 }
653
654 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
655
656 ret = hid_parse_report(hid, rdesc, rsize);
657 kfree(rdesc);
658 if (ret) {
659 dbg_hid("parsing report descriptor failed\n");
660 return ret;
661 }
662
663 return 0;
664 }
665
666 static int i2c_hid_start(struct hid_device *hid)
667 {
668 struct i2c_client *client = hid->driver_data;
669 struct i2c_hid *ihid = i2c_get_clientdata(client);
670 int ret;
671 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
672
673 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
674 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
675 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
676
677 if (bufsize > ihid->bufsize) {
678 i2c_hid_free_buffers(ihid);
679
680 ret = i2c_hid_alloc_buffers(ihid, bufsize);
681
682 if (ret)
683 return ret;
684 }
685
686 if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
687 i2c_hid_init_reports(hid);
688
689 return 0;
690 }
691
692 static void i2c_hid_stop(struct hid_device *hid)
693 {
694 struct i2c_client *client = hid->driver_data;
695 struct i2c_hid *ihid = i2c_get_clientdata(client);
696
697 hid->claimed = 0;
698
699 i2c_hid_free_buffers(ihid);
700 }
701
702 static int i2c_hid_open(struct hid_device *hid)
703 {
704 struct i2c_client *client = hid->driver_data;
705 struct i2c_hid *ihid = i2c_get_clientdata(client);
706 int ret = 0;
707
708 mutex_lock(&i2c_hid_open_mut);
709 if (!hid->open++) {
710 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
711 if (ret) {
712 hid->open--;
713 goto done;
714 }
715 set_bit(I2C_HID_STARTED, &ihid->flags);
716 }
717 done:
718 mutex_unlock(&i2c_hid_open_mut);
719 return ret;
720 }
721
722 static void i2c_hid_close(struct hid_device *hid)
723 {
724 struct i2c_client *client = hid->driver_data;
725 struct i2c_hid *ihid = i2c_get_clientdata(client);
726
727 /* protecting hid->open to make sure we don't restart
728 * data acquistion due to a resumption we no longer
729 * care about
730 */
731 mutex_lock(&i2c_hid_open_mut);
732 if (!--hid->open) {
733 clear_bit(I2C_HID_STARTED, &ihid->flags);
734
735 /* Save some power */
736 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
737 }
738 mutex_unlock(&i2c_hid_open_mut);
739 }
740
741 static int i2c_hid_power(struct hid_device *hid, int lvl)
742 {
743 struct i2c_client *client = hid->driver_data;
744 struct i2c_hid *ihid = i2c_get_clientdata(client);
745 int ret = 0;
746
747 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
748
749 switch (lvl) {
750 case PM_HINT_FULLON:
751 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
752 break;
753 case PM_HINT_NORMAL:
754 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
755 break;
756 }
757 return ret;
758 }
759
760 static struct hid_ll_driver i2c_hid_ll_driver = {
761 .parse = i2c_hid_parse,
762 .start = i2c_hid_start,
763 .stop = i2c_hid_stop,
764 .open = i2c_hid_open,
765 .close = i2c_hid_close,
766 .power = i2c_hid_power,
767 .request = i2c_hid_request,
768 };
769
770 static int i2c_hid_init_irq(struct i2c_client *client)
771 {
772 struct i2c_hid *ihid = i2c_get_clientdata(client);
773 int ret;
774
775 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
776
777 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
778 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
779 client->name, ihid);
780 if (ret < 0) {
781 dev_warn(&client->dev,
782 "Could not register for %s interrupt, irq = %d,"
783 " ret = %d\n",
784 client->name, client->irq, ret);
785
786 return ret;
787 }
788
789 return 0;
790 }
791
792 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
793 {
794 struct i2c_client *client = ihid->client;
795 struct i2c_hid_desc *hdesc = &ihid->hdesc;
796 unsigned int dsize;
797 int ret;
798
799 /* Fetch the length of HID description, retrieve the 4 first bytes:
800 * bytes 0-1 -> length
801 * bytes 2-3 -> bcdVersion (has to be 1.00) */
802 ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
803
804 i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %4ph\n", __func__,
805 ihid->hdesc_buffer);
806
807 if (ret) {
808 dev_err(&client->dev,
809 "unable to fetch the size of HID descriptor (ret=%d)\n",
810 ret);
811 return -ENODEV;
812 }
813
814 dsize = le16_to_cpu(hdesc->wHIDDescLength);
815 /*
816 * the size of the HID descriptor should at least contain
817 * its size and the bcdVersion (4 bytes), and should not be greater
818 * than sizeof(struct i2c_hid_desc) as we directly fill this struct
819 * through i2c_hid_command.
820 */
821 if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
822 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
823 dsize);
824 return -ENODEV;
825 }
826
827 /* check bcdVersion == 1.0 */
828 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
829 dev_err(&client->dev,
830 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
831 le16_to_cpu(hdesc->bcdVersion));
832 return -ENODEV;
833 }
834
835 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
836
837 ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
838 dsize);
839 if (ret) {
840 dev_err(&client->dev, "hid_descr_cmd Fail\n");
841 return -ENODEV;
842 }
843
844 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
845
846 return 0;
847 }
848
849 #ifdef CONFIG_ACPI
850 static int i2c_hid_acpi_pdata(struct i2c_client *client,
851 struct i2c_hid_platform_data *pdata)
852 {
853 static u8 i2c_hid_guid[] = {
854 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
855 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
856 };
857 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
858 union acpi_object params[4], *obj;
859 struct acpi_object_list input;
860 struct acpi_device *adev;
861 acpi_handle handle;
862
863 handle = ACPI_HANDLE(&client->dev);
864 if (!handle || acpi_bus_get_device(handle, &adev))
865 return -ENODEV;
866
867 input.count = ARRAY_SIZE(params);
868 input.pointer = params;
869
870 params[0].type = ACPI_TYPE_BUFFER;
871 params[0].buffer.length = sizeof(i2c_hid_guid);
872 params[0].buffer.pointer = i2c_hid_guid;
873 params[1].type = ACPI_TYPE_INTEGER;
874 params[1].integer.value = 1;
875 params[2].type = ACPI_TYPE_INTEGER;
876 params[2].integer.value = 1; /* HID function */
877 params[3].type = ACPI_TYPE_PACKAGE;
878 params[3].package.count = 0;
879 params[3].package.elements = NULL;
880
881 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
882 dev_err(&client->dev, "device _DSM execution failed\n");
883 return -ENODEV;
884 }
885
886 obj = (union acpi_object *)buf.pointer;
887 if (obj->type != ACPI_TYPE_INTEGER) {
888 dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
889 obj->type);
890 kfree(buf.pointer);
891 return -EINVAL;
892 }
893
894 pdata->hid_descriptor_address = obj->integer.value;
895
896 kfree(buf.pointer);
897 return 0;
898 }
899
900 static const struct acpi_device_id i2c_hid_acpi_match[] = {
901 {"ACPI0C50", 0 },
902 {"PNP0C50", 0 },
903 { },
904 };
905 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
906 #else
907 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
908 struct i2c_hid_platform_data *pdata)
909 {
910 return -ENODEV;
911 }
912 #endif
913
914 #ifdef CONFIG_OF
915 static int i2c_hid_of_probe(struct i2c_client *client,
916 struct i2c_hid_platform_data *pdata)
917 {
918 struct device *dev = &client->dev;
919 u32 val;
920 int ret;
921
922 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
923 if (ret) {
924 dev_err(&client->dev, "HID register address not provided\n");
925 return -ENODEV;
926 }
927 if (val >> 16) {
928 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
929 val);
930 return -EINVAL;
931 }
932 pdata->hid_descriptor_address = val;
933
934 return 0;
935 }
936
937 static const struct of_device_id i2c_hid_of_match[] = {
938 { .compatible = "hid-over-i2c" },
939 {},
940 };
941 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
942 #else
943 static inline int i2c_hid_of_probe(struct i2c_client *client,
944 struct i2c_hid_platform_data *pdata)
945 {
946 return -ENODEV;
947 }
948 #endif
949
950 static int i2c_hid_probe(struct i2c_client *client,
951 const struct i2c_device_id *dev_id)
952 {
953 int ret;
954 struct i2c_hid *ihid;
955 struct hid_device *hid;
956 __u16 hidRegister;
957 struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
958
959 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
960
961 if (!client->irq) {
962 dev_err(&client->dev,
963 "HID over i2c has not been provided an Int IRQ\n");
964 return -EINVAL;
965 }
966
967 ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
968 if (!ihid)
969 return -ENOMEM;
970
971 if (client->dev.of_node) {
972 ret = i2c_hid_of_probe(client, &ihid->pdata);
973 if (ret)
974 goto err;
975 } else if (!platform_data) {
976 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
977 if (ret) {
978 dev_err(&client->dev,
979 "HID register address not provided\n");
980 goto err;
981 }
982 } else {
983 ihid->pdata = *platform_data;
984 }
985
986 i2c_set_clientdata(client, ihid);
987
988 ihid->client = client;
989
990 hidRegister = ihid->pdata.hid_descriptor_address;
991 ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
992
993 init_waitqueue_head(&ihid->wait);
994
995 /* we need to allocate the command buffer without knowing the maximum
996 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
997 * real computation later. */
998 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
999 if (ret < 0)
1000 goto err;
1001
1002 ret = i2c_hid_fetch_hid_descriptor(ihid);
1003 if (ret < 0)
1004 goto err;
1005
1006 ret = i2c_hid_init_irq(client);
1007 if (ret < 0)
1008 goto err;
1009
1010 hid = hid_allocate_device();
1011 if (IS_ERR(hid)) {
1012 ret = PTR_ERR(hid);
1013 goto err_irq;
1014 }
1015
1016 ihid->hid = hid;
1017
1018 hid->driver_data = client;
1019 hid->ll_driver = &i2c_hid_ll_driver;
1020 hid->hid_get_raw_report = i2c_hid_get_raw_report;
1021 hid->hid_output_raw_report = i2c_hid_output_raw_report;
1022 hid->dev.parent = &client->dev;
1023 ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
1024 hid->bus = BUS_I2C;
1025 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1026 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1027 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1028
1029 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1030 client->name, hid->vendor, hid->product);
1031
1032 ret = hid_add_device(hid);
1033 if (ret) {
1034 if (ret != -ENODEV)
1035 hid_err(client, "can't add hid device: %d\n", ret);
1036 goto err_mem_free;
1037 }
1038
1039 return 0;
1040
1041 err_mem_free:
1042 hid_destroy_device(hid);
1043
1044 err_irq:
1045 free_irq(client->irq, ihid);
1046
1047 err:
1048 i2c_hid_free_buffers(ihid);
1049 kfree(ihid);
1050 return ret;
1051 }
1052
1053 static int i2c_hid_remove(struct i2c_client *client)
1054 {
1055 struct i2c_hid *ihid = i2c_get_clientdata(client);
1056 struct hid_device *hid;
1057
1058 hid = ihid->hid;
1059 hid_destroy_device(hid);
1060
1061 free_irq(client->irq, ihid);
1062
1063 if (ihid->bufsize)
1064 i2c_hid_free_buffers(ihid);
1065
1066 kfree(ihid);
1067
1068 return 0;
1069 }
1070
1071 #ifdef CONFIG_PM_SLEEP
1072 static int i2c_hid_suspend(struct device *dev)
1073 {
1074 struct i2c_client *client = to_i2c_client(dev);
1075
1076 if (device_may_wakeup(&client->dev))
1077 enable_irq_wake(client->irq);
1078
1079 /* Save some power */
1080 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1081
1082 return 0;
1083 }
1084
1085 static int i2c_hid_resume(struct device *dev)
1086 {
1087 int ret;
1088 struct i2c_client *client = to_i2c_client(dev);
1089
1090 ret = i2c_hid_hwreset(client);
1091 if (ret)
1092 return ret;
1093
1094 if (device_may_wakeup(&client->dev))
1095 disable_irq_wake(client->irq);
1096
1097 return 0;
1098 }
1099 #endif
1100
1101 static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
1102
1103 static const struct i2c_device_id i2c_hid_id_table[] = {
1104 { "hid", 0 },
1105 { },
1106 };
1107 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1108
1109
1110 static struct i2c_driver i2c_hid_driver = {
1111 .driver = {
1112 .name = "i2c_hid",
1113 .owner = THIS_MODULE,
1114 .pm = &i2c_hid_pm,
1115 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1116 .of_match_table = of_match_ptr(i2c_hid_of_match),
1117 },
1118
1119 .probe = i2c_hid_probe,
1120 .remove = i2c_hid_remove,
1121
1122 .id_table = i2c_hid_id_table,
1123 };
1124
1125 module_i2c_driver(i2c_hid_driver);
1126
1127 MODULE_DESCRIPTION("HID over I2C core driver");
1128 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1129 MODULE_LICENSE("GPL");
Linux with added FPC-III support