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of: MSI: Simplify irqdomain lookup
[linux/fpc-iii.git] / drivers / hid / i2c-hid / i2c-hid.c
blob10bd8e6e4c9c814cbceb863bbff4a87f3d3a283a
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 #include <linux/gpio/consumer.h>
41
42 #include <linux/i2c/i2c-hid.h>
43
44 /* flags */
45 #define I2C_HID_STARTED 0
46 #define I2C_HID_RESET_PENDING 1
47 #define I2C_HID_READ_PENDING 2
48
49 #define I2C_HID_PWR_ON 0x00
50 #define I2C_HID_PWR_SLEEP 0x01
51
52 /* debug option */
53 static bool debug;
54 module_param(debug, bool, 0444);
55 MODULE_PARM_DESC(debug, "print a lot of debug information");
56
57 #define i2c_hid_dbg(ihid, fmt, arg...) \
58 do { \
59 if (debug) \
60 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
61 } while (0)
62
63 struct i2c_hid_desc {
64 __le16 wHIDDescLength;
65 __le16 bcdVersion;
66 __le16 wReportDescLength;
67 __le16 wReportDescRegister;
68 __le16 wInputRegister;
69 __le16 wMaxInputLength;
70 __le16 wOutputRegister;
71 __le16 wMaxOutputLength;
72 __le16 wCommandRegister;
73 __le16 wDataRegister;
74 __le16 wVendorID;
75 __le16 wProductID;
76 __le16 wVersionID;
77 __le32 reserved;
78 } __packed;
79
80 struct i2c_hid_cmd {
81 unsigned int registerIndex;
82 __u8 opcode;
83 unsigned int length;
84 bool wait;
85 };
86
87 union command {
88 u8 data[0];
89 struct cmd {
90 __le16 reg;
91 __u8 reportTypeID;
92 __u8 opcode;
93 } __packed c;
94 };
95
96 #define I2C_HID_CMD(opcode_) \
97 .opcode = opcode_, .length = 4, \
98 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
99
100 /* fetch HID descriptor */
101 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
102 /* fetch report descriptors */
103 static const struct i2c_hid_cmd hid_report_descr_cmd = {
104 .registerIndex = offsetof(struct i2c_hid_desc,
105 wReportDescRegister),
106 .opcode = 0x00,
107 .length = 2 };
108 /* commands */
109 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
110 .wait = true };
111 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
112 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) };
113 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
114 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 };
115
116 /*
117 * These definitions are not used here, but are defined by the spec.
118 * Keeping them here for documentation purposes.
119 *
120 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
121 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
122 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
123 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
124 */
125
126 static DEFINE_MUTEX(i2c_hid_open_mut);
127
128 /* The main device structure */
129 struct i2c_hid {
130 struct i2c_client *client; /* i2c client */
131 struct hid_device *hid; /* pointer to corresponding HID dev */
132 union {
133 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
134 struct i2c_hid_desc hdesc; /* the HID Descriptor */
135 };
136 __le16 wHIDDescRegister; /* location of the i2c
137 * register of the HID
138 * descriptor. */
139 unsigned int bufsize; /* i2c buffer size */
140 char *inbuf; /* Input buffer */
141 char *rawbuf; /* Raw Input buffer */
142 char *cmdbuf; /* Command buffer */
143 char *argsbuf; /* Command arguments buffer */
144
145 unsigned long flags; /* device flags */
146
147 wait_queue_head_t wait; /* For waiting the interrupt */
148 struct gpio_desc *desc;
149 int irq;
150
151 struct i2c_hid_platform_data pdata;
152
153 bool irq_wake_enabled;
154 };
155
156 static int __i2c_hid_command(struct i2c_client *client,
157 const struct i2c_hid_cmd *command, u8 reportID,
158 u8 reportType, u8 *args, int args_len,
159 unsigned char *buf_recv, int data_len)
160 {
161 struct i2c_hid *ihid = i2c_get_clientdata(client);
162 union command *cmd = (union command *)ihid->cmdbuf;
163 int ret;
164 struct i2c_msg msg[2];
165 int msg_num = 1;
166
167 int length = command->length;
168 bool wait = command->wait;
169 unsigned int registerIndex = command->registerIndex;
170
171 /* special case for hid_descr_cmd */
172 if (command == &hid_descr_cmd) {
173 cmd->c.reg = ihid->wHIDDescRegister;
174 } else {
175 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
176 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
177 }
178
179 if (length > 2) {
180 cmd->c.opcode = command->opcode;
181 cmd->c.reportTypeID = reportID | reportType << 4;
182 }
183
184 memcpy(cmd->data + length, args, args_len);
185 length += args_len;
186
187 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
188
189 msg[0].addr = client->addr;
190 msg[0].flags = client->flags & I2C_M_TEN;
191 msg[0].len = length;
192 msg[0].buf = cmd->data;
193 if (data_len > 0) {
194 msg[1].addr = client->addr;
195 msg[1].flags = client->flags & I2C_M_TEN;
196 msg[1].flags |= I2C_M_RD;
197 msg[1].len = data_len;
198 msg[1].buf = buf_recv;
199 msg_num = 2;
200 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
201 }
202
203 if (wait)
204 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
205
206 ret = i2c_transfer(client->adapter, msg, msg_num);
207
208 if (data_len > 0)
209 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
210
211 if (ret != msg_num)
212 return ret < 0 ? ret : -EIO;
213
214 ret = 0;
215
216 if (wait) {
217 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
218 if (!wait_event_timeout(ihid->wait,
219 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
220 msecs_to_jiffies(5000)))
221 ret = -ENODATA;
222 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
223 }
224
225 return ret;
226 }
227
228 static int i2c_hid_command(struct i2c_client *client,
229 const struct i2c_hid_cmd *command,
230 unsigned char *buf_recv, int data_len)
231 {
232 return __i2c_hid_command(client, command, 0, 0, NULL, 0,
233 buf_recv, data_len);
234 }
235
236 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
237 u8 reportID, unsigned char *buf_recv, int data_len)
238 {
239 struct i2c_hid *ihid = i2c_get_clientdata(client);
240 u8 args[3];
241 int ret;
242 int args_len = 0;
243 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
244
245 i2c_hid_dbg(ihid, "%s\n", __func__);
246
247 if (reportID >= 0x0F) {
248 args[args_len++] = reportID;
249 reportID = 0x0F;
250 }
251
252 args[args_len++] = readRegister & 0xFF;
253 args[args_len++] = readRegister >> 8;
254
255 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
256 reportType, args, args_len, buf_recv, data_len);
257 if (ret) {
258 dev_err(&client->dev,
259 "failed to retrieve report from device.\n");
260 return ret;
261 }
262
263 return 0;
264 }
265
266 /**
267 * i2c_hid_set_or_send_report: forward an incoming report to the device
268 * @client: the i2c_client of the device
269 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
270 * @reportID: the report ID
271 * @buf: the actual data to transfer, without the report ID
272 * @len: size of buf
273 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
274 */
275 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
276 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
277 {
278 struct i2c_hid *ihid = i2c_get_clientdata(client);
279 u8 *args = ihid->argsbuf;
280 const struct i2c_hid_cmd *hidcmd;
281 int ret;
282 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
283 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
284 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
285
286 /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
287 u16 size = 2 /* size */ +
288 (reportID ? 1 : 0) /* reportID */ +
289 data_len /* buf */;
290 int args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
291 2 /* dataRegister */ +
292 size /* args */;
293 int index = 0;
294
295 i2c_hid_dbg(ihid, "%s\n", __func__);
296
297 if (!use_data && maxOutputLength == 0)
298 return -ENOSYS;
299
300 if (reportID >= 0x0F) {
301 args[index++] = reportID;
302 reportID = 0x0F;
303 }
304
305 /*
306 * use the data register for feature reports or if the device does not
307 * support the output register
308 */
309 if (use_data) {
310 args[index++] = dataRegister & 0xFF;
311 args[index++] = dataRegister >> 8;
312 hidcmd = &hid_set_report_cmd;
313 } else {
314 args[index++] = outputRegister & 0xFF;
315 args[index++] = outputRegister >> 8;
316 hidcmd = &hid_no_cmd;
317 }
318
319 args[index++] = size & 0xFF;
320 args[index++] = size >> 8;
321
322 if (reportID)
323 args[index++] = reportID;
324
325 memcpy(&args[index], buf, data_len);
326
327 ret = __i2c_hid_command(client, hidcmd, reportID,
328 reportType, args, args_len, NULL, 0);
329 if (ret) {
330 dev_err(&client->dev, "failed to set a report to device.\n");
331 return ret;
332 }
333
334 return data_len;
335 }
336
337 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
338 {
339 struct i2c_hid *ihid = i2c_get_clientdata(client);
340 int ret;
341
342 i2c_hid_dbg(ihid, "%s\n", __func__);
343
344 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
345 0, NULL, 0, NULL, 0);
346 if (ret)
347 dev_err(&client->dev, "failed to change power setting.\n");
348
349 return ret;
350 }
351
352 static int i2c_hid_hwreset(struct i2c_client *client)
353 {
354 struct i2c_hid *ihid = i2c_get_clientdata(client);
355 int ret;
356
357 i2c_hid_dbg(ihid, "%s\n", __func__);
358
359 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
360 if (ret)
361 return ret;
362
363 i2c_hid_dbg(ihid, "resetting...\n");
364
365 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
366 if (ret) {
367 dev_err(&client->dev, "failed to reset device.\n");
368 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
369 return ret;
370 }
371
372 return 0;
373 }
374
375 static void i2c_hid_get_input(struct i2c_hid *ihid)
376 {
377 int ret, ret_size;
378 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
379
380 if (size > ihid->bufsize)
381 size = ihid->bufsize;
382
383 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
384 if (ret != size) {
385 if (ret < 0)
386 return;
387
388 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
389 __func__, ret, size);
390 return;
391 }
392
393 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
394
395 if (!ret_size) {
396 /* host or device initiated RESET completed */
397 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
398 wake_up(&ihid->wait);
399 return;
400 }
401
402 if (ret_size > size) {
403 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
404 __func__, size, ret_size);
405 return;
406 }
407
408 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
409
410 if (test_bit(I2C_HID_STARTED, &ihid->flags))
411 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
412 ret_size - 2, 1);
413
414 return;
415 }
416
417 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
418 {
419 struct i2c_hid *ihid = dev_id;
420
421 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
422 return IRQ_HANDLED;
423
424 i2c_hid_get_input(ihid);
425
426 return IRQ_HANDLED;
427 }
428
429 static int i2c_hid_get_report_length(struct hid_report *report)
430 {
431 return ((report->size - 1) >> 3) + 1 +
432 report->device->report_enum[report->type].numbered + 2;
433 }
434
435 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
436 size_t bufsize)
437 {
438 struct hid_device *hid = report->device;
439 struct i2c_client *client = hid->driver_data;
440 struct i2c_hid *ihid = i2c_get_clientdata(client);
441 unsigned int size, ret_size;
442
443 size = i2c_hid_get_report_length(report);
444 if (i2c_hid_get_report(client,
445 report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
446 report->id, buffer, size))
447 return;
448
449 i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
450
451 ret_size = buffer[0] | (buffer[1] << 8);
452
453 if (ret_size != size) {
454 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
455 __func__, size, ret_size);
456 return;
457 }
458
459 /* hid->driver_lock is held as we are in probe function,
460 * we just need to setup the input fields, so using
461 * hid_report_raw_event is safe. */
462 hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
463 }
464
465 /*
466 * Initialize all reports
467 */
468 static void i2c_hid_init_reports(struct hid_device *hid)
469 {
470 struct hid_report *report;
471 struct i2c_client *client = hid->driver_data;
472 struct i2c_hid *ihid = i2c_get_clientdata(client);
473 u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
474
475 if (!inbuf) {
476 dev_err(&client->dev, "can not retrieve initial reports\n");
477 return;
478 }
479
480 /*
481 * The device must be powered on while we fetch initial reports
482 * from it.
483 */
484 pm_runtime_get_sync(&client->dev);
485
486 list_for_each_entry(report,
487 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
488 i2c_hid_init_report(report, inbuf, ihid->bufsize);
489
490 pm_runtime_put(&client->dev);
491
492 kfree(inbuf);
493 }
494
495 /*
496 * Traverse the supplied list of reports and find the longest
497 */
498 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
499 unsigned int *max)
500 {
501 struct hid_report *report;
502 unsigned int size;
503
504 /* We should not rely on wMaxInputLength, as some devices may set it to
505 * a wrong length. */
506 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
507 size = i2c_hid_get_report_length(report);
508 if (*max < size)
509 *max = size;
510 }
511 }
512
513 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
514 {
515 kfree(ihid->inbuf);
516 kfree(ihid->rawbuf);
517 kfree(ihid->argsbuf);
518 kfree(ihid->cmdbuf);
519 ihid->inbuf = NULL;
520 ihid->rawbuf = NULL;
521 ihid->cmdbuf = NULL;
522 ihid->argsbuf = NULL;
523 ihid->bufsize = 0;
524 }
525
526 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
527 {
528 /* the worst case is computed from the set_report command with a
529 * reportID > 15 and the maximum report length */
530 int args_len = sizeof(__u8) + /* optional ReportID byte */
531 sizeof(__u16) + /* data register */
532 sizeof(__u16) + /* size of the report */
533 report_size; /* report */
534
535 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
536 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
537 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
538 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
539
540 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
541 i2c_hid_free_buffers(ihid);
542 return -ENOMEM;
543 }
544
545 ihid->bufsize = report_size;
546
547 return 0;
548 }
549
550 static int i2c_hid_get_raw_report(struct hid_device *hid,
551 unsigned char report_number, __u8 *buf, size_t count,
552 unsigned char report_type)
553 {
554 struct i2c_client *client = hid->driver_data;
555 struct i2c_hid *ihid = i2c_get_clientdata(client);
556 size_t ret_count, ask_count;
557 int ret;
558
559 if (report_type == HID_OUTPUT_REPORT)
560 return -EINVAL;
561
562 /* +2 bytes to include the size of the reply in the query buffer */
563 ask_count = min(count + 2, (size_t)ihid->bufsize);
564
565 ret = i2c_hid_get_report(client,
566 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
567 report_number, ihid->rawbuf, ask_count);
568
569 if (ret < 0)
570 return ret;
571
572 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
573
574 if (ret_count <= 2)
575 return 0;
576
577 ret_count = min(ret_count, ask_count);
578
579 /* The query buffer contains the size, dropping it in the reply */
580 count = min(count, ret_count - 2);
581 memcpy(buf, ihid->rawbuf + 2, count);
582
583 return count;
584 }
585
586 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
587 size_t count, unsigned char report_type, bool use_data)
588 {
589 struct i2c_client *client = hid->driver_data;
590 int report_id = buf[0];
591 int ret;
592
593 if (report_type == HID_INPUT_REPORT)
594 return -EINVAL;
595
596 if (report_id) {
597 buf++;
598 count--;
599 }
600
601 ret = i2c_hid_set_or_send_report(client,
602 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
603 report_id, buf, count, use_data);
604
605 if (report_id && ret >= 0)
606 ret++; /* add report_id to the number of transfered bytes */
607
608 return ret;
609 }
610
611 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
612 size_t count)
613 {
614 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
615 false);
616 }
617
618 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
619 __u8 *buf, size_t len, unsigned char rtype,
620 int reqtype)
621 {
622 switch (reqtype) {
623 case HID_REQ_GET_REPORT:
624 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
625 case HID_REQ_SET_REPORT:
626 if (buf[0] != reportnum)
627 return -EINVAL;
628 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
629 default:
630 return -EIO;
631 }
632 }
633
634 static int i2c_hid_parse(struct hid_device *hid)
635 {
636 struct i2c_client *client = hid->driver_data;
637 struct i2c_hid *ihid = i2c_get_clientdata(client);
638 struct i2c_hid_desc *hdesc = &ihid->hdesc;
639 unsigned int rsize;
640 char *rdesc;
641 int ret;
642 int tries = 3;
643
644 i2c_hid_dbg(ihid, "entering %s\n", __func__);
645
646 rsize = le16_to_cpu(hdesc->wReportDescLength);
647 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
648 dbg_hid("weird size of report descriptor (%u)\n", rsize);
649 return -EINVAL;
650 }
651
652 do {
653 ret = i2c_hid_hwreset(client);
654 if (ret)
655 msleep(1000);
656 } while (tries-- > 0 && ret);
657
658 if (ret)
659 return ret;
660
661 rdesc = kzalloc(rsize, GFP_KERNEL);
662
663 if (!rdesc) {
664 dbg_hid("couldn't allocate rdesc memory\n");
665 return -ENOMEM;
666 }
667
668 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
669
670 ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
671 if (ret) {
672 hid_err(hid, "reading report descriptor failed\n");
673 kfree(rdesc);
674 return -EIO;
675 }
676
677 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
678
679 ret = hid_parse_report(hid, rdesc, rsize);
680 kfree(rdesc);
681 if (ret) {
682 dbg_hid("parsing report descriptor failed\n");
683 return ret;
684 }
685
686 return 0;
687 }
688
689 static int i2c_hid_start(struct hid_device *hid)
690 {
691 struct i2c_client *client = hid->driver_data;
692 struct i2c_hid *ihid = i2c_get_clientdata(client);
693 int ret;
694 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
695
696 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
697 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
698 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
699
700 if (bufsize > ihid->bufsize) {
701 i2c_hid_free_buffers(ihid);
702
703 ret = i2c_hid_alloc_buffers(ihid, bufsize);
704
705 if (ret)
706 return ret;
707 }
708
709 if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
710 i2c_hid_init_reports(hid);
711
712 return 0;
713 }
714
715 static void i2c_hid_stop(struct hid_device *hid)
716 {
717 hid->claimed = 0;
718 }
719
720 static int i2c_hid_open(struct hid_device *hid)
721 {
722 struct i2c_client *client = hid->driver_data;
723 struct i2c_hid *ihid = i2c_get_clientdata(client);
724 int ret = 0;
725
726 mutex_lock(&i2c_hid_open_mut);
727 if (!hid->open++) {
728 ret = pm_runtime_get_sync(&client->dev);
729 if (ret < 0) {
730 hid->open--;
731 goto done;
732 }
733 set_bit(I2C_HID_STARTED, &ihid->flags);
734 }
735 done:
736 mutex_unlock(&i2c_hid_open_mut);
737 return ret < 0 ? ret : 0;
738 }
739
740 static void i2c_hid_close(struct hid_device *hid)
741 {
742 struct i2c_client *client = hid->driver_data;
743 struct i2c_hid *ihid = i2c_get_clientdata(client);
744
745 /* protecting hid->open to make sure we don't restart
746 * data acquistion due to a resumption we no longer
747 * care about
748 */
749 mutex_lock(&i2c_hid_open_mut);
750 if (!--hid->open) {
751 clear_bit(I2C_HID_STARTED, &ihid->flags);
752
753 /* Save some power */
754 pm_runtime_put(&client->dev);
755 }
756 mutex_unlock(&i2c_hid_open_mut);
757 }
758
759 static int i2c_hid_power(struct hid_device *hid, int lvl)
760 {
761 struct i2c_client *client = hid->driver_data;
762 struct i2c_hid *ihid = i2c_get_clientdata(client);
763
764 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
765
766 switch (lvl) {
767 case PM_HINT_FULLON:
768 pm_runtime_get_sync(&client->dev);
769 break;
770 case PM_HINT_NORMAL:
771 pm_runtime_put(&client->dev);
772 break;
773 }
774 return 0;
775 }
776
777 static struct hid_ll_driver i2c_hid_ll_driver = {
778 .parse = i2c_hid_parse,
779 .start = i2c_hid_start,
780 .stop = i2c_hid_stop,
781 .open = i2c_hid_open,
782 .close = i2c_hid_close,
783 .power = i2c_hid_power,
784 .output_report = i2c_hid_output_report,
785 .raw_request = i2c_hid_raw_request,
786 };
787
788 static int i2c_hid_init_irq(struct i2c_client *client)
789 {
790 struct i2c_hid *ihid = i2c_get_clientdata(client);
791 int ret;
792
793 dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
794
795 ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
796 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
797 client->name, ihid);
798 if (ret < 0) {
799 dev_warn(&client->dev,
800 "Could not register for %s interrupt, irq = %d,"
801 " ret = %d\n",
802 client->name, ihid->irq, ret);
803
804 return ret;
805 }
806
807 return 0;
808 }
809
810 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
811 {
812 struct i2c_client *client = ihid->client;
813 struct i2c_hid_desc *hdesc = &ihid->hdesc;
814 unsigned int dsize;
815 int ret;
816
817 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
818 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
819 ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
820 sizeof(struct i2c_hid_desc));
821 if (ret) {
822 dev_err(&client->dev, "hid_descr_cmd failed\n");
823 return -ENODEV;
824 }
825
826 /* Validate the length of HID descriptor, the 4 first bytes:
827 * bytes 0-1 -> length
828 * bytes 2-3 -> bcdVersion (has to be 1.00) */
829 /* check bcdVersion == 1.0 */
830 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
831 dev_err(&client->dev,
832 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
833 le16_to_cpu(hdesc->bcdVersion));
834 return -ENODEV;
835 }
836
837 /* Descriptor length should be 30 bytes as per the specification */
838 dsize = le16_to_cpu(hdesc->wHIDDescLength);
839 if (dsize != sizeof(struct i2c_hid_desc)) {
840 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
841 dsize);
842 return -ENODEV;
843 }
844 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
845 return 0;
846 }
847
848 #ifdef CONFIG_ACPI
849
850 /* Default GPIO mapping */
851 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
852 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
853 { "gpios", &i2c_hid_irq_gpio, 1 },
854 { },
855 };
856
857 static int i2c_hid_acpi_pdata(struct i2c_client *client,
858 struct i2c_hid_platform_data *pdata)
859 {
860 static u8 i2c_hid_guid[] = {
861 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
862 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
863 };
864 union acpi_object *obj;
865 struct acpi_device *adev;
866 acpi_handle handle;
867 int ret;
868
869 handle = ACPI_HANDLE(&client->dev);
870 if (!handle || acpi_bus_get_device(handle, &adev))
871 return -ENODEV;
872
873 obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
874 ACPI_TYPE_INTEGER);
875 if (!obj) {
876 dev_err(&client->dev, "device _DSM execution failed\n");
877 return -ENODEV;
878 }
879
880 pdata->hid_descriptor_address = obj->integer.value;
881 ACPI_FREE(obj);
882
883 /* GPIOs are optional */
884 ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
885 return ret < 0 && ret != -ENXIO ? ret : 0;
886 }
887
888 static const struct acpi_device_id i2c_hid_acpi_match[] = {
889 {"ACPI0C50", 0 },
890 {"PNP0C50", 0 },
891 { },
892 };
893 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
894 #else
895 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
896 struct i2c_hid_platform_data *pdata)
897 {
898 return -ENODEV;
899 }
900 #endif
901
902 #ifdef CONFIG_OF
903 static int i2c_hid_of_probe(struct i2c_client *client,
904 struct i2c_hid_platform_data *pdata)
905 {
906 struct device *dev = &client->dev;
907 u32 val;
908 int ret;
909
910 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
911 if (ret) {
912 dev_err(&client->dev, "HID register address not provided\n");
913 return -ENODEV;
914 }
915 if (val >> 16) {
916 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
917 val);
918 return -EINVAL;
919 }
920 pdata->hid_descriptor_address = val;
921
922 return 0;
923 }
924
925 static const struct of_device_id i2c_hid_of_match[] = {
926 { .compatible = "hid-over-i2c" },
927 {},
928 };
929 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
930 #else
931 static inline int i2c_hid_of_probe(struct i2c_client *client,
932 struct i2c_hid_platform_data *pdata)
933 {
934 return -ENODEV;
935 }
936 #endif
937
938 static int i2c_hid_probe(struct i2c_client *client,
939 const struct i2c_device_id *dev_id)
940 {
941 int ret;
942 struct i2c_hid *ihid;
943 struct hid_device *hid;
944 __u16 hidRegister;
945 struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
946
947 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
948
949 ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
950 if (!ihid)
951 return -ENOMEM;
952
953 if (client->dev.of_node) {
954 ret = i2c_hid_of_probe(client, &ihid->pdata);
955 if (ret)
956 goto err;
957 } else if (!platform_data) {
958 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
959 if (ret) {
960 dev_err(&client->dev,
961 "HID register address not provided\n");
962 goto err;
963 }
964 } else {
965 ihid->pdata = *platform_data;
966 }
967
968 if (client->irq > 0) {
969 ihid->irq = client->irq;
970 } else if (ACPI_COMPANION(&client->dev)) {
971 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
972 if (IS_ERR(ihid->desc)) {
973 dev_err(&client->dev, "Failed to get GPIO interrupt\n");
974 return PTR_ERR(ihid->desc);
975 }
976
977 ihid->irq = gpiod_to_irq(ihid->desc);
978 if (ihid->irq < 0) {
979 gpiod_put(ihid->desc);
980 dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
981 return ihid->irq;
982 }
983 }
984
985 i2c_set_clientdata(client, ihid);
986
987 ihid->client = client;
988
989 hidRegister = ihid->pdata.hid_descriptor_address;
990 ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
991
992 init_waitqueue_head(&ihid->wait);
993
994 /* we need to allocate the command buffer without knowing the maximum
995 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
996 * real computation later. */
997 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
998 if (ret < 0)
999 goto err;
1000
1001 pm_runtime_get_noresume(&client->dev);
1002 pm_runtime_set_active(&client->dev);
1003 pm_runtime_enable(&client->dev);
1004
1005 ret = i2c_hid_fetch_hid_descriptor(ihid);
1006 if (ret < 0)
1007 goto err_pm;
1008
1009 ret = i2c_hid_init_irq(client);
1010 if (ret < 0)
1011 goto err_pm;
1012
1013 hid = hid_allocate_device();
1014 if (IS_ERR(hid)) {
1015 ret = PTR_ERR(hid);
1016 goto err_irq;
1017 }
1018
1019 ihid->hid = hid;
1020
1021 hid->driver_data = client;
1022 hid->ll_driver = &i2c_hid_ll_driver;
1023 hid->dev.parent = &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 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1032
1033 ret = hid_add_device(hid);
1034 if (ret) {
1035 if (ret != -ENODEV)
1036 hid_err(client, "can't add hid device: %d\n", ret);
1037 goto err_mem_free;
1038 }
1039
1040 pm_runtime_put(&client->dev);
1041 return 0;
1042
1043 err_mem_free:
1044 hid_destroy_device(hid);
1045
1046 err_irq:
1047 free_irq(ihid->irq, ihid);
1048
1049 err_pm:
1050 pm_runtime_put_noidle(&client->dev);
1051 pm_runtime_disable(&client->dev);
1052
1053 err:
1054 if (ihid->desc)
1055 gpiod_put(ihid->desc);
1056
1057 i2c_hid_free_buffers(ihid);
1058 kfree(ihid);
1059 return ret;
1060 }
1061
1062 static int i2c_hid_remove(struct i2c_client *client)
1063 {
1064 struct i2c_hid *ihid = i2c_get_clientdata(client);
1065 struct hid_device *hid;
1066
1067 pm_runtime_get_sync(&client->dev);
1068 pm_runtime_disable(&client->dev);
1069 pm_runtime_set_suspended(&client->dev);
1070 pm_runtime_put_noidle(&client->dev);
1071
1072 hid = ihid->hid;
1073 hid_destroy_device(hid);
1074
1075 free_irq(ihid->irq, ihid);
1076
1077 if (ihid->bufsize)
1078 i2c_hid_free_buffers(ihid);
1079
1080 if (ihid->desc)
1081 gpiod_put(ihid->desc);
1082
1083 kfree(ihid);
1084
1085 acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1086
1087 return 0;
1088 }
1089
1090 #ifdef CONFIG_PM_SLEEP
1091 static int i2c_hid_suspend(struct device *dev)
1092 {
1093 struct i2c_client *client = to_i2c_client(dev);
1094 struct i2c_hid *ihid = i2c_get_clientdata(client);
1095 struct hid_device *hid = ihid->hid;
1096 int ret = 0;
1097 int wake_status;
1098
1099 if (hid->driver && hid->driver->suspend)
1100 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1101
1102 disable_irq(ihid->irq);
1103 if (device_may_wakeup(&client->dev)) {
1104 wake_status = enable_irq_wake(ihid->irq);
1105 if (!wake_status)
1106 ihid->irq_wake_enabled = true;
1107 else
1108 hid_warn(hid, "Failed to enable irq wake: %d\n",
1109 wake_status);
1110 }
1111
1112 /* Save some power */
1113 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1114
1115 return ret;
1116 }
1117
1118 static int i2c_hid_resume(struct device *dev)
1119 {
1120 int ret;
1121 struct i2c_client *client = to_i2c_client(dev);
1122 struct i2c_hid *ihid = i2c_get_clientdata(client);
1123 struct hid_device *hid = ihid->hid;
1124 int wake_status;
1125
1126 enable_irq(ihid->irq);
1127 ret = i2c_hid_hwreset(client);
1128 if (ret)
1129 return ret;
1130
1131 if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1132 wake_status = disable_irq_wake(ihid->irq);
1133 if (!wake_status)
1134 ihid->irq_wake_enabled = false;
1135 else
1136 hid_warn(hid, "Failed to disable irq wake: %d\n",
1137 wake_status);
1138 }
1139
1140 if (hid->driver && hid->driver->reset_resume) {
1141 ret = hid->driver->reset_resume(hid);
1142 return ret;
1143 }
1144
1145 return 0;
1146 }
1147 #endif
1148
1149 #ifdef CONFIG_PM
1150 static int i2c_hid_runtime_suspend(struct device *dev)
1151 {
1152 struct i2c_client *client = to_i2c_client(dev);
1153 struct i2c_hid *ihid = i2c_get_clientdata(client);
1154
1155 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1156 disable_irq(ihid->irq);
1157 return 0;
1158 }
1159
1160 static int i2c_hid_runtime_resume(struct device *dev)
1161 {
1162 struct i2c_client *client = to_i2c_client(dev);
1163 struct i2c_hid *ihid = i2c_get_clientdata(client);
1164
1165 enable_irq(ihid->irq);
1166 i2c_hid_set_power(client, I2C_HID_PWR_ON);
1167 return 0;
1168 }
1169 #endif
1170
1171 static const struct dev_pm_ops i2c_hid_pm = {
1172 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1173 SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1174 NULL)
1175 };
1176
1177 static const struct i2c_device_id i2c_hid_id_table[] = {
1178 { "hid", 0 },
1179 { },
1180 };
1181 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1182
1183
1184 static struct i2c_driver i2c_hid_driver = {
1185 .driver = {
1186 .name = "i2c_hid",
1187 .owner = THIS_MODULE,
1188 .pm = &i2c_hid_pm,
1189 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1190 .of_match_table = of_match_ptr(i2c_hid_of_match),
1191 },
1192
1193 .probe = i2c_hid_probe,
1194 .remove = i2c_hid_remove,
1195
1196 .id_table = i2c_hid_id_table,
1197 };
1198
1199 module_i2c_driver(i2c_hid_driver);
1200
1201 MODULE_DESCRIPTION("HID over I2C core driver");
1202 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1203 MODULE_LICENSE("GPL");
Linux with added FPC-III support