?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
arm: Add devicetree fixup machine function
[linux/fpc-iii.git] / drivers / hid / i2c-hid / i2c-hid.c
blob21aafc8f48c87d483110da79b6e85481d35d904c
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/pm_runtime.h>
29 #include <linux/device.h>
30 #include <linux/wait.h>
31 #include <linux/err.h>
32 #include <linux/string.h>
33 #include <linux/list.h>
34 #include <linux/jiffies.h>
35 #include <linux/kernel.h>
36 #include <linux/hid.h>
37 #include <linux/mutex.h>
38 #include <linux/acpi.h>
39 #include <linux/of.h>
40
41 #include <linux/i2c/i2c-hid.h>
42
43 /* flags */
44 #define I2C_HID_STARTED (1 << 0)
45 #define I2C_HID_RESET_PENDING (1 << 1)
46 #define I2C_HID_READ_PENDING (1 << 2)
47
48 #define I2C_HID_PWR_ON 0x00
49 #define I2C_HID_PWR_SLEEP 0x01
50
51 /* debug option */
52 static bool debug;
53 module_param(debug, bool, 0444);
54 MODULE_PARM_DESC(debug, "print a lot of debug information");
55
56 #define i2c_hid_dbg(ihid, fmt, arg...) \
57 do { \
58 if (debug) \
59 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
60 } while (0)
61
62 struct i2c_hid_desc {
63 __le16 wHIDDescLength;
64 __le16 bcdVersion;
65 __le16 wReportDescLength;
66 __le16 wReportDescRegister;
67 __le16 wInputRegister;
68 __le16 wMaxInputLength;
69 __le16 wOutputRegister;
70 __le16 wMaxOutputLength;
71 __le16 wCommandRegister;
72 __le16 wDataRegister;
73 __le16 wVendorID;
74 __le16 wProductID;
75 __le16 wVersionID;
76 __le32 reserved;
77 } __packed;
78
79 struct i2c_hid_cmd {
80 unsigned int registerIndex;
81 __u8 opcode;
82 unsigned int length;
83 bool wait;
84 };
85
86 union command {
87 u8 data[0];
88 struct cmd {
89 __le16 reg;
90 __u8 reportTypeID;
91 __u8 opcode;
92 } __packed c;
93 };
94
95 #define I2C_HID_CMD(opcode_) \
96 .opcode = opcode_, .length = 4, \
97 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
98
99 /* fetch HID descriptor */
100 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
101 /* fetch report descriptors */
102 static const struct i2c_hid_cmd hid_report_descr_cmd = {
103 .registerIndex = offsetof(struct i2c_hid_desc,
104 wReportDescRegister),
105 .opcode = 0x00,
106 .length = 2 };
107 /* commands */
108 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
109 .wait = true };
110 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
111 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) };
112 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
113 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 };
114
115 /*
116 * These definitions are not used here, but are defined by the spec.
117 * Keeping them here for documentation purposes.
118 *
119 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
120 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
121 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
122 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
123 */
124
125 static DEFINE_MUTEX(i2c_hid_open_mut);
126
127 /* The main device structure */
128 struct i2c_hid {
129 struct i2c_client *client; /* i2c client */
130 struct hid_device *hid; /* pointer to corresponding HID dev */
131 union {
132 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
133 struct i2c_hid_desc hdesc; /* the HID Descriptor */
134 };
135 __le16 wHIDDescRegister; /* location of the i2c
136 * register of the HID
137 * descriptor. */
138 unsigned int bufsize; /* i2c buffer size */
139 char *inbuf; /* Input buffer */
140 char *cmdbuf; /* Command buffer */
141 char *argsbuf; /* Command arguments buffer */
142
143 unsigned long flags; /* device flags */
144
145 wait_queue_head_t wait; /* For waiting the interrupt */
146
147 struct i2c_hid_platform_data pdata;
148 };
149
150 static int __i2c_hid_command(struct i2c_client *client,
151 const struct i2c_hid_cmd *command, u8 reportID,
152 u8 reportType, u8 *args, int args_len,
153 unsigned char *buf_recv, int data_len)
154 {
155 struct i2c_hid *ihid = i2c_get_clientdata(client);
156 union command *cmd = (union command *)ihid->cmdbuf;
157 int ret;
158 struct i2c_msg msg[2];
159 int msg_num = 1;
160
161 int length = command->length;
162 bool wait = command->wait;
163 unsigned int registerIndex = command->registerIndex;
164
165 /* special case for hid_descr_cmd */
166 if (command == &hid_descr_cmd) {
167 cmd->c.reg = ihid->wHIDDescRegister;
168 } else {
169 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
170 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
171 }
172
173 if (length > 2) {
174 cmd->c.opcode = command->opcode;
175 cmd->c.reportTypeID = reportID | reportType << 4;
176 }
177
178 memcpy(cmd->data + length, args, args_len);
179 length += args_len;
180
181 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
182
183 msg[0].addr = client->addr;
184 msg[0].flags = client->flags & I2C_M_TEN;
185 msg[0].len = length;
186 msg[0].buf = cmd->data;
187 if (data_len > 0) {
188 msg[1].addr = client->addr;
189 msg[1].flags = client->flags & I2C_M_TEN;
190 msg[1].flags |= I2C_M_RD;
191 msg[1].len = data_len;
192 msg[1].buf = buf_recv;
193 msg_num = 2;
194 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
195 }
196
197 if (wait)
198 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
199
200 ret = i2c_transfer(client->adapter, msg, msg_num);
201
202 if (data_len > 0)
203 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
204
205 if (ret != msg_num)
206 return ret < 0 ? ret : -EIO;
207
208 ret = 0;
209
210 if (wait) {
211 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
212 if (!wait_event_timeout(ihid->wait,
213 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
214 msecs_to_jiffies(5000)))
215 ret = -ENODATA;
216 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
217 }
218
219 return ret;
220 }
221
222 static int i2c_hid_command(struct i2c_client *client,
223 const struct i2c_hid_cmd *command,
224 unsigned char *buf_recv, int data_len)
225 {
226 return __i2c_hid_command(client, command, 0, 0, NULL, 0,
227 buf_recv, data_len);
228 }
229
230 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
231 u8 reportID, unsigned char *buf_recv, int data_len)
232 {
233 struct i2c_hid *ihid = i2c_get_clientdata(client);
234 u8 args[3];
235 int ret;
236 int args_len = 0;
237 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
238
239 i2c_hid_dbg(ihid, "%s\n", __func__);
240
241 if (reportID >= 0x0F) {
242 args[args_len++] = reportID;
243 reportID = 0x0F;
244 }
245
246 args[args_len++] = readRegister & 0xFF;
247 args[args_len++] = readRegister >> 8;
248
249 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
250 reportType, args, args_len, buf_recv, data_len);
251 if (ret) {
252 dev_err(&client->dev,
253 "failed to retrieve report from device.\n");
254 return ret;
255 }
256
257 return 0;
258 }
259
260 /**
261 * i2c_hid_set_or_send_report: forward an incoming report to the device
262 * @client: the i2c_client of the device
263 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
264 * @reportID: the report ID
265 * @buf: the actual data to transfer, without the report ID
266 * @len: size of buf
267 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
268 */
269 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
270 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
271 {
272 struct i2c_hid *ihid = i2c_get_clientdata(client);
273 u8 *args = ihid->argsbuf;
274 const struct i2c_hid_cmd *hidcmd;
275 int ret;
276 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
277 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
278 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
279
280 /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
281 u16 size = 2 /* size */ +
282 (reportID ? 1 : 0) /* reportID */ +
283 data_len /* buf */;
284 int args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
285 2 /* dataRegister */ +
286 size /* args */;
287 int index = 0;
288
289 i2c_hid_dbg(ihid, "%s\n", __func__);
290
291 if (!use_data && maxOutputLength == 0)
292 return -ENOSYS;
293
294 if (reportID >= 0x0F) {
295 args[index++] = reportID;
296 reportID = 0x0F;
297 }
298
299 /*
300 * use the data register for feature reports or if the device does not
301 * support the output register
302 */
303 if (use_data) {
304 args[index++] = dataRegister & 0xFF;
305 args[index++] = dataRegister >> 8;
306 hidcmd = &hid_set_report_cmd;
307 } else {
308 args[index++] = outputRegister & 0xFF;
309 args[index++] = outputRegister >> 8;
310 hidcmd = &hid_no_cmd;
311 }
312
313 args[index++] = size & 0xFF;
314 args[index++] = size >> 8;
315
316 if (reportID)
317 args[index++] = reportID;
318
319 memcpy(&args[index], buf, data_len);
320
321 ret = __i2c_hid_command(client, hidcmd, reportID,
322 reportType, args, args_len, NULL, 0);
323 if (ret) {
324 dev_err(&client->dev, "failed to set a report to device.\n");
325 return ret;
326 }
327
328 return data_len;
329 }
330
331 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
332 {
333 struct i2c_hid *ihid = i2c_get_clientdata(client);
334 int ret;
335
336 i2c_hid_dbg(ihid, "%s\n", __func__);
337
338 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
339 0, NULL, 0, NULL, 0);
340 if (ret)
341 dev_err(&client->dev, "failed to change power setting.\n");
342
343 return ret;
344 }
345
346 static int i2c_hid_hwreset(struct i2c_client *client)
347 {
348 struct i2c_hid *ihid = i2c_get_clientdata(client);
349 int ret;
350
351 i2c_hid_dbg(ihid, "%s\n", __func__);
352
353 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
354 if (ret)
355 return ret;
356
357 i2c_hid_dbg(ihid, "resetting...\n");
358
359 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
360 if (ret) {
361 dev_err(&client->dev, "failed to reset device.\n");
362 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
363 return ret;
364 }
365
366 return 0;
367 }
368
369 static void i2c_hid_get_input(struct i2c_hid *ihid)
370 {
371 int ret, ret_size;
372 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
373
374 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
375 if (ret != size) {
376 if (ret < 0)
377 return;
378
379 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
380 __func__, ret, size);
381 return;
382 }
383
384 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
385
386 if (!ret_size) {
387 /* host or device initiated RESET completed */
388 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
389 wake_up(&ihid->wait);
390 return;
391 }
392
393 if (ret_size > size) {
394 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
395 __func__, size, ret_size);
396 return;
397 }
398
399 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
400
401 if (test_bit(I2C_HID_STARTED, &ihid->flags))
402 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
403 ret_size - 2, 1);
404
405 return;
406 }
407
408 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
409 {
410 struct i2c_hid *ihid = dev_id;
411
412 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
413 return IRQ_HANDLED;
414
415 i2c_hid_get_input(ihid);
416
417 return IRQ_HANDLED;
418 }
419
420 static int i2c_hid_get_report_length(struct hid_report *report)
421 {
422 return ((report->size - 1) >> 3) + 1 +
423 report->device->report_enum[report->type].numbered + 2;
424 }
425
426 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
427 size_t bufsize)
428 {
429 struct hid_device *hid = report->device;
430 struct i2c_client *client = hid->driver_data;
431 struct i2c_hid *ihid = i2c_get_clientdata(client);
432 unsigned int size, ret_size;
433
434 size = i2c_hid_get_report_length(report);
435 if (i2c_hid_get_report(client,
436 report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
437 report->id, buffer, size))
438 return;
439
440 i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
441
442 ret_size = buffer[0] | (buffer[1] << 8);
443
444 if (ret_size != size) {
445 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
446 __func__, size, ret_size);
447 return;
448 }
449
450 /* hid->driver_lock is held as we are in probe function,
451 * we just need to setup the input fields, so using
452 * hid_report_raw_event is safe. */
453 hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
454 }
455
456 /*
457 * Initialize all reports
458 */
459 static void i2c_hid_init_reports(struct hid_device *hid)
460 {
461 struct hid_report *report;
462 struct i2c_client *client = hid->driver_data;
463 struct i2c_hid *ihid = i2c_get_clientdata(client);
464 u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
465
466 if (!inbuf) {
467 dev_err(&client->dev, "can not retrieve initial reports\n");
468 return;
469 }
470
471 /*
472 * The device must be powered on while we fetch initial reports
473 * from it.
474 */
475 pm_runtime_get_sync(&client->dev);
476
477 list_for_each_entry(report,
478 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
479 i2c_hid_init_report(report, inbuf, ihid->bufsize);
480
481 pm_runtime_put(&client->dev);
482
483 kfree(inbuf);
484 }
485
486 /*
487 * Traverse the supplied list of reports and find the longest
488 */
489 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
490 unsigned int *max)
491 {
492 struct hid_report *report;
493 unsigned int size;
494
495 /* We should not rely on wMaxInputLength, as some devices may set it to
496 * a wrong length. */
497 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
498 size = i2c_hid_get_report_length(report);
499 if (*max < size)
500 *max = size;
501 }
502 }
503
504 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
505 {
506 kfree(ihid->inbuf);
507 kfree(ihid->argsbuf);
508 kfree(ihid->cmdbuf);
509 ihid->inbuf = NULL;
510 ihid->cmdbuf = NULL;
511 ihid->argsbuf = NULL;
512 ihid->bufsize = 0;
513 }
514
515 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
516 {
517 /* the worst case is computed from the set_report command with a
518 * reportID > 15 and the maximum report length */
519 int args_len = sizeof(__u8) + /* optional ReportID byte */
520 sizeof(__u16) + /* data register */
521 sizeof(__u16) + /* size of the report */
522 report_size; /* report */
523
524 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
525 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
526 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
527
528 if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
529 i2c_hid_free_buffers(ihid);
530 return -ENOMEM;
531 }
532
533 ihid->bufsize = report_size;
534
535 return 0;
536 }
537
538 static int i2c_hid_get_raw_report(struct hid_device *hid,
539 unsigned char report_number, __u8 *buf, size_t count,
540 unsigned char report_type)
541 {
542 struct i2c_client *client = hid->driver_data;
543 struct i2c_hid *ihid = i2c_get_clientdata(client);
544 size_t ret_count, ask_count;
545 int ret;
546
547 if (report_type == HID_OUTPUT_REPORT)
548 return -EINVAL;
549
550 /* +2 bytes to include the size of the reply in the query buffer */
551 ask_count = min(count + 2, (size_t)ihid->bufsize);
552
553 ret = i2c_hid_get_report(client,
554 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
555 report_number, ihid->inbuf, ask_count);
556
557 if (ret < 0)
558 return ret;
559
560 ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
561
562 if (ret_count <= 2)
563 return 0;
564
565 ret_count = min(ret_count, ask_count);
566
567 /* The query buffer contains the size, dropping it in the reply */
568 count = min(count, ret_count - 2);
569 memcpy(buf, ihid->inbuf + 2, count);
570
571 return count;
572 }
573
574 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
575 size_t count, unsigned char report_type, bool use_data)
576 {
577 struct i2c_client *client = hid->driver_data;
578 int report_id = buf[0];
579 int ret;
580
581 if (report_type == HID_INPUT_REPORT)
582 return -EINVAL;
583
584 if (report_id) {
585 buf++;
586 count--;
587 }
588
589 ret = i2c_hid_set_or_send_report(client,
590 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
591 report_id, buf, count, use_data);
592
593 if (report_id && ret >= 0)
594 ret++; /* add report_id to the number of transfered bytes */
595
596 return ret;
597 }
598
599 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
600 size_t count)
601 {
602 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
603 false);
604 }
605
606 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
607 __u8 *buf, size_t len, unsigned char rtype,
608 int reqtype)
609 {
610 switch (reqtype) {
611 case HID_REQ_GET_REPORT:
612 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
613 case HID_REQ_SET_REPORT:
614 if (buf[0] != reportnum)
615 return -EINVAL;
616 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
617 default:
618 return -EIO;
619 }
620 }
621
622 static int i2c_hid_parse(struct hid_device *hid)
623 {
624 struct i2c_client *client = hid->driver_data;
625 struct i2c_hid *ihid = i2c_get_clientdata(client);
626 struct i2c_hid_desc *hdesc = &ihid->hdesc;
627 unsigned int rsize;
628 char *rdesc;
629 int ret;
630 int tries = 3;
631
632 i2c_hid_dbg(ihid, "entering %s\n", __func__);
633
634 rsize = le16_to_cpu(hdesc->wReportDescLength);
635 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
636 dbg_hid("weird size of report descriptor (%u)\n", rsize);
637 return -EINVAL;
638 }
639
640 do {
641 ret = i2c_hid_hwreset(client);
642 if (ret)
643 msleep(1000);
644 } while (tries-- > 0 && ret);
645
646 if (ret)
647 return ret;
648
649 rdesc = kzalloc(rsize, GFP_KERNEL);
650
651 if (!rdesc) {
652 dbg_hid("couldn't allocate rdesc memory\n");
653 return -ENOMEM;
654 }
655
656 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
657
658 ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
659 if (ret) {
660 hid_err(hid, "reading report descriptor failed\n");
661 kfree(rdesc);
662 return -EIO;
663 }
664
665 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
666
667 ret = hid_parse_report(hid, rdesc, rsize);
668 kfree(rdesc);
669 if (ret) {
670 dbg_hid("parsing report descriptor failed\n");
671 return ret;
672 }
673
674 return 0;
675 }
676
677 static int i2c_hid_start(struct hid_device *hid)
678 {
679 struct i2c_client *client = hid->driver_data;
680 struct i2c_hid *ihid = i2c_get_clientdata(client);
681 int ret;
682 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
683
684 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
685 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
686 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
687
688 if (bufsize > ihid->bufsize) {
689 i2c_hid_free_buffers(ihid);
690
691 ret = i2c_hid_alloc_buffers(ihid, bufsize);
692
693 if (ret)
694 return ret;
695 }
696
697 if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
698 i2c_hid_init_reports(hid);
699
700 return 0;
701 }
702
703 static void i2c_hid_stop(struct hid_device *hid)
704 {
705 struct i2c_client *client = hid->driver_data;
706 struct i2c_hid *ihid = i2c_get_clientdata(client);
707
708 hid->claimed = 0;
709
710 i2c_hid_free_buffers(ihid);
711 }
712
713 static int i2c_hid_open(struct hid_device *hid)
714 {
715 struct i2c_client *client = hid->driver_data;
716 struct i2c_hid *ihid = i2c_get_clientdata(client);
717 int ret = 0;
718
719 mutex_lock(&i2c_hid_open_mut);
720 if (!hid->open++) {
721 ret = pm_runtime_get_sync(&client->dev);
722 if (ret < 0) {
723 hid->open--;
724 goto done;
725 }
726 set_bit(I2C_HID_STARTED, &ihid->flags);
727 }
728 done:
729 mutex_unlock(&i2c_hid_open_mut);
730 return ret < 0 ? ret : 0;
731 }
732
733 static void i2c_hid_close(struct hid_device *hid)
734 {
735 struct i2c_client *client = hid->driver_data;
736 struct i2c_hid *ihid = i2c_get_clientdata(client);
737
738 /* protecting hid->open to make sure we don't restart
739 * data acquistion due to a resumption we no longer
740 * care about
741 */
742 mutex_lock(&i2c_hid_open_mut);
743 if (!--hid->open) {
744 clear_bit(I2C_HID_STARTED, &ihid->flags);
745
746 /* Save some power */
747 pm_runtime_put(&client->dev);
748 }
749 mutex_unlock(&i2c_hid_open_mut);
750 }
751
752 static int i2c_hid_power(struct hid_device *hid, int lvl)
753 {
754 struct i2c_client *client = hid->driver_data;
755 struct i2c_hid *ihid = i2c_get_clientdata(client);
756
757 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
758
759 switch (lvl) {
760 case PM_HINT_FULLON:
761 pm_runtime_get_sync(&client->dev);
762 break;
763 case PM_HINT_NORMAL:
764 pm_runtime_put(&client->dev);
765 break;
766 }
767 return 0;
768 }
769
770 static struct hid_ll_driver i2c_hid_ll_driver = {
771 .parse = i2c_hid_parse,
772 .start = i2c_hid_start,
773 .stop = i2c_hid_stop,
774 .open = i2c_hid_open,
775 .close = i2c_hid_close,
776 .power = i2c_hid_power,
777 .output_report = i2c_hid_output_report,
778 .raw_request = i2c_hid_raw_request,
779 };
780
781 static int i2c_hid_init_irq(struct i2c_client *client)
782 {
783 struct i2c_hid *ihid = i2c_get_clientdata(client);
784 int ret;
785
786 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
787
788 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
789 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
790 client->name, ihid);
791 if (ret < 0) {
792 dev_warn(&client->dev,
793 "Could not register for %s interrupt, irq = %d,"
794 " ret = %d\n",
795 client->name, client->irq, ret);
796
797 return ret;
798 }
799
800 return 0;
801 }
802
803 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
804 {
805 struct i2c_client *client = ihid->client;
806 struct i2c_hid_desc *hdesc = &ihid->hdesc;
807 unsigned int dsize;
808 int ret;
809
810 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
811 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
812 ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
813 sizeof(struct i2c_hid_desc));
814 if (ret) {
815 dev_err(&client->dev, "hid_descr_cmd failed\n");
816 return -ENODEV;
817 }
818
819 /* Validate the length of HID descriptor, the 4 first bytes:
820 * bytes 0-1 -> length
821 * bytes 2-3 -> bcdVersion (has to be 1.00) */
822 /* check bcdVersion == 1.0 */
823 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
824 dev_err(&client->dev,
825 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
826 le16_to_cpu(hdesc->bcdVersion));
827 return -ENODEV;
828 }
829
830 /* Descriptor length should be 30 bytes as per the specification */
831 dsize = le16_to_cpu(hdesc->wHIDDescLength);
832 if (dsize != sizeof(struct i2c_hid_desc)) {
833 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
834 dsize);
835 return -ENODEV;
836 }
837 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
838 return 0;
839 }
840
841 #ifdef CONFIG_ACPI
842 static int i2c_hid_acpi_pdata(struct i2c_client *client,
843 struct i2c_hid_platform_data *pdata)
844 {
845 static u8 i2c_hid_guid[] = {
846 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
847 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
848 };
849 union acpi_object *obj;
850 struct acpi_device *adev;
851 acpi_handle handle;
852
853 handle = ACPI_HANDLE(&client->dev);
854 if (!handle || acpi_bus_get_device(handle, &adev))
855 return -ENODEV;
856
857 obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
858 ACPI_TYPE_INTEGER);
859 if (!obj) {
860 dev_err(&client->dev, "device _DSM execution failed\n");
861 return -ENODEV;
862 }
863
864 pdata->hid_descriptor_address = obj->integer.value;
865 ACPI_FREE(obj);
866
867 return 0;
868 }
869
870 static const struct acpi_device_id i2c_hid_acpi_match[] = {
871 {"ACPI0C50", 0 },
872 {"PNP0C50", 0 },
873 { },
874 };
875 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
876 #else
877 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
878 struct i2c_hid_platform_data *pdata)
879 {
880 return -ENODEV;
881 }
882 #endif
883
884 #ifdef CONFIG_OF
885 static int i2c_hid_of_probe(struct i2c_client *client,
886 struct i2c_hid_platform_data *pdata)
887 {
888 struct device *dev = &client->dev;
889 u32 val;
890 int ret;
891
892 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
893 if (ret) {
894 dev_err(&client->dev, "HID register address not provided\n");
895 return -ENODEV;
896 }
897 if (val >> 16) {
898 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
899 val);
900 return -EINVAL;
901 }
902 pdata->hid_descriptor_address = val;
903
904 return 0;
905 }
906
907 static const struct of_device_id i2c_hid_of_match[] = {
908 { .compatible = "hid-over-i2c" },
909 {},
910 };
911 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
912 #else
913 static inline int i2c_hid_of_probe(struct i2c_client *client,
914 struct i2c_hid_platform_data *pdata)
915 {
916 return -ENODEV;
917 }
918 #endif
919
920 static int i2c_hid_probe(struct i2c_client *client,
921 const struct i2c_device_id *dev_id)
922 {
923 int ret;
924 struct i2c_hid *ihid;
925 struct hid_device *hid;
926 __u16 hidRegister;
927 struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
928
929 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
930
931 if (!client->irq) {
932 dev_err(&client->dev,
933 "HID over i2c has not been provided an Int IRQ\n");
934 return -EINVAL;
935 }
936
937 ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
938 if (!ihid)
939 return -ENOMEM;
940
941 if (client->dev.of_node) {
942 ret = i2c_hid_of_probe(client, &ihid->pdata);
943 if (ret)
944 goto err;
945 } else if (!platform_data) {
946 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
947 if (ret) {
948 dev_err(&client->dev,
949 "HID register address not provided\n");
950 goto err;
951 }
952 } else {
953 ihid->pdata = *platform_data;
954 }
955
956 i2c_set_clientdata(client, ihid);
957
958 ihid->client = client;
959
960 hidRegister = ihid->pdata.hid_descriptor_address;
961 ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
962
963 init_waitqueue_head(&ihid->wait);
964
965 /* we need to allocate the command buffer without knowing the maximum
966 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
967 * real computation later. */
968 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
969 if (ret < 0)
970 goto err;
971
972 pm_runtime_get_noresume(&client->dev);
973 pm_runtime_set_active(&client->dev);
974 pm_runtime_enable(&client->dev);
975
976 ret = i2c_hid_fetch_hid_descriptor(ihid);
977 if (ret < 0)
978 goto err_pm;
979
980 ret = i2c_hid_init_irq(client);
981 if (ret < 0)
982 goto err_pm;
983
984 hid = hid_allocate_device();
985 if (IS_ERR(hid)) {
986 ret = PTR_ERR(hid);
987 goto err_irq;
988 }
989
990 ihid->hid = hid;
991
992 hid->driver_data = client;
993 hid->ll_driver = &i2c_hid_ll_driver;
994 hid->dev.parent = &client->dev;
995 ACPI_COMPANION_SET(&hid->dev, ACPI_COMPANION(&client->dev));
996 hid->bus = BUS_I2C;
997 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
998 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
999 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1000
1001 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1002 client->name, hid->vendor, hid->product);
1003
1004 ret = hid_add_device(hid);
1005 if (ret) {
1006 if (ret != -ENODEV)
1007 hid_err(client, "can't add hid device: %d\n", ret);
1008 goto err_mem_free;
1009 }
1010
1011 pm_runtime_put(&client->dev);
1012 return 0;
1013
1014 err_mem_free:
1015 hid_destroy_device(hid);
1016
1017 err_irq:
1018 free_irq(client->irq, ihid);
1019
1020 err_pm:
1021 pm_runtime_put_noidle(&client->dev);
1022 pm_runtime_disable(&client->dev);
1023
1024 err:
1025 i2c_hid_free_buffers(ihid);
1026 kfree(ihid);
1027 return ret;
1028 }
1029
1030 static int i2c_hid_remove(struct i2c_client *client)
1031 {
1032 struct i2c_hid *ihid = i2c_get_clientdata(client);
1033 struct hid_device *hid;
1034
1035 pm_runtime_get_sync(&client->dev);
1036 pm_runtime_disable(&client->dev);
1037 pm_runtime_set_suspended(&client->dev);
1038 pm_runtime_put_noidle(&client->dev);
1039
1040 hid = ihid->hid;
1041 hid_destroy_device(hid);
1042
1043 free_irq(client->irq, ihid);
1044
1045 if (ihid->bufsize)
1046 i2c_hid_free_buffers(ihid);
1047
1048 kfree(ihid);
1049
1050 return 0;
1051 }
1052
1053 #ifdef CONFIG_PM_SLEEP
1054 static int i2c_hid_suspend(struct device *dev)
1055 {
1056 struct i2c_client *client = to_i2c_client(dev);
1057
1058 disable_irq(client->irq);
1059 if (device_may_wakeup(&client->dev))
1060 enable_irq_wake(client->irq);
1061
1062 /* Save some power */
1063 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1064
1065 return 0;
1066 }
1067
1068 static int i2c_hid_resume(struct device *dev)
1069 {
1070 int ret;
1071 struct i2c_client *client = to_i2c_client(dev);
1072
1073 enable_irq(client->irq);
1074 ret = i2c_hid_hwreset(client);
1075 if (ret)
1076 return ret;
1077
1078 if (device_may_wakeup(&client->dev))
1079 disable_irq_wake(client->irq);
1080
1081 return 0;
1082 }
1083 #endif
1084
1085 #ifdef CONFIG_PM_RUNTIME
1086 static int i2c_hid_runtime_suspend(struct device *dev)
1087 {
1088 struct i2c_client *client = to_i2c_client(dev);
1089
1090 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1091 disable_irq(client->irq);
1092 return 0;
1093 }
1094
1095 static int i2c_hid_runtime_resume(struct device *dev)
1096 {
1097 struct i2c_client *client = to_i2c_client(dev);
1098
1099 enable_irq(client->irq);
1100 i2c_hid_set_power(client, I2C_HID_PWR_ON);
1101 return 0;
1102 }
1103 #endif
1104
1105 static const struct dev_pm_ops i2c_hid_pm = {
1106 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1107 SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1108 NULL)
1109 };
1110
1111 static const struct i2c_device_id i2c_hid_id_table[] = {
1112 { "hid", 0 },
1113 { },
1114 };
1115 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1116
1117
1118 static struct i2c_driver i2c_hid_driver = {
1119 .driver = {
1120 .name = "i2c_hid",
1121 .owner = THIS_MODULE,
1122 .pm = &i2c_hid_pm,
1123 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1124 .of_match_table = of_match_ptr(i2c_hid_of_match),
1125 },
1126
1127 .probe = i2c_hid_probe,
1128 .remove = i2c_hid_remove,
1129
1130 .id_table = i2c_hid_id_table,
1131 };
1132
1133 module_i2c_driver(i2c_hid_driver);
1134
1135 MODULE_DESCRIPTION("HID over I2C core driver");
1136 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1137 MODULE_LICENSE("GPL");
Linux with added FPC-III support