HID: remove initial reading of reports at connect
[muen/linux.git] / drivers / hid / i2c-hid / i2c-hid.c
1 /*
2  * HID over I2C protocol implementation
3  *
4  * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
5  * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
6  * Copyright (c) 2012 Red Hat, Inc
7  *
8  * This code is partly based on "USB HID support for Linux":
9  *
10  *  Copyright (c) 1999 Andreas Gal
11  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
12  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
13  *  Copyright (c) 2007-2008 Oliver Neukum
14  *  Copyright (c) 2006-2010 Jiri Kosina
15  *
16  * This file is subject to the terms and conditions of the GNU General Public
17  * License.  See the file COPYING in the main directory of this archive for
18  * more details.
19  */
20
21 #include <linux/module.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/input.h>
25 #include <linux/irq.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/pm.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/device.h>
31 #include <linux/wait.h>
32 #include <linux/err.h>
33 #include <linux/string.h>
34 #include <linux/list.h>
35 #include <linux/jiffies.h>
36 #include <linux/kernel.h>
37 #include <linux/hid.h>
38 #include <linux/mutex.h>
39 #include <linux/acpi.h>
40 #include <linux/of.h>
41 #include <linux/regulator/consumer.h>
42
43 #include <linux/i2c/i2c-hid.h>
44
45 #include "../hid-ids.h"
46
47 /* quirks to control the device */
48 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV        BIT(0)
49
50 /* flags */
51 #define I2C_HID_STARTED         0
52 #define I2C_HID_RESET_PENDING   1
53 #define I2C_HID_READ_PENDING    2
54
55 #define I2C_HID_PWR_ON          0x00
56 #define I2C_HID_PWR_SLEEP       0x01
57
58 /* debug option */
59 static bool debug;
60 module_param(debug, bool, 0444);
61 MODULE_PARM_DESC(debug, "print a lot of debug information");
62
63 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
64 do {                                                                      \
65         if (debug)                                                        \
66                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
67 } while (0)
68
69 struct i2c_hid_desc {
70         __le16 wHIDDescLength;
71         __le16 bcdVersion;
72         __le16 wReportDescLength;
73         __le16 wReportDescRegister;
74         __le16 wInputRegister;
75         __le16 wMaxInputLength;
76         __le16 wOutputRegister;
77         __le16 wMaxOutputLength;
78         __le16 wCommandRegister;
79         __le16 wDataRegister;
80         __le16 wVendorID;
81         __le16 wProductID;
82         __le16 wVersionID;
83         __le32 reserved;
84 } __packed;
85
86 struct i2c_hid_cmd {
87         unsigned int registerIndex;
88         __u8 opcode;
89         unsigned int length;
90         bool wait;
91 };
92
93 union command {
94         u8 data[0];
95         struct cmd {
96                 __le16 reg;
97                 __u8 reportTypeID;
98                 __u8 opcode;
99         } __packed c;
100 };
101
102 #define I2C_HID_CMD(opcode_) \
103         .opcode = opcode_, .length = 4, \
104         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
105
106 /* fetch HID descriptor */
107 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
108 /* fetch report descriptors */
109 static const struct i2c_hid_cmd hid_report_descr_cmd = {
110                 .registerIndex = offsetof(struct i2c_hid_desc,
111                         wReportDescRegister),
112                 .opcode = 0x00,
113                 .length = 2 };
114 /* commands */
115 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
116                                                           .wait = true };
117 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
118 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
119 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
120 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
121
122 /*
123  * These definitions are not used here, but are defined by the spec.
124  * Keeping them here for documentation purposes.
125  *
126  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
127  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
128  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
129  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
130  */
131
132 static DEFINE_MUTEX(i2c_hid_open_mut);
133
134 /* The main device structure */
135 struct i2c_hid {
136         struct i2c_client       *client;        /* i2c client */
137         struct hid_device       *hid;   /* pointer to corresponding HID dev */
138         union {
139                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
140                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
141         };
142         __le16                  wHIDDescRegister; /* location of the i2c
143                                                    * register of the HID
144                                                    * descriptor. */
145         unsigned int            bufsize;        /* i2c buffer size */
146         char                    *inbuf;         /* Input buffer */
147         char                    *rawbuf;        /* Raw Input buffer */
148         char                    *cmdbuf;        /* Command buffer */
149         char                    *argsbuf;       /* Command arguments buffer */
150
151         unsigned long           flags;          /* device flags */
152         unsigned long           quirks;         /* Various quirks */
153
154         wait_queue_head_t       wait;           /* For waiting the interrupt */
155
156         struct i2c_hid_platform_data pdata;
157
158         bool                    irq_wake_enabled;
159         struct mutex            reset_lock;
160 };
161
162 static const struct i2c_hid_quirks {
163         __u16 idVendor;
164         __u16 idProduct;
165         __u32 quirks;
166 } i2c_hid_quirks[] = {
167         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
168                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
169         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
170                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
171         { 0, 0 }
172 };
173
174 /*
175  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
176  * @idVendor: the 16-bit vendor ID
177  * @idProduct: the 16-bit product ID
178  *
179  * Returns: a u32 quirks value.
180  */
181 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
182 {
183         u32 quirks = 0;
184         int n;
185
186         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
187                 if (i2c_hid_quirks[n].idVendor == idVendor &&
188                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
189                      i2c_hid_quirks[n].idProduct == idProduct))
190                         quirks = i2c_hid_quirks[n].quirks;
191
192         return quirks;
193 }
194
195 static int __i2c_hid_command(struct i2c_client *client,
196                 const struct i2c_hid_cmd *command, u8 reportID,
197                 u8 reportType, u8 *args, int args_len,
198                 unsigned char *buf_recv, int data_len)
199 {
200         struct i2c_hid *ihid = i2c_get_clientdata(client);
201         union command *cmd = (union command *)ihid->cmdbuf;
202         int ret;
203         struct i2c_msg msg[2];
204         int msg_num = 1;
205
206         int length = command->length;
207         bool wait = command->wait;
208         unsigned int registerIndex = command->registerIndex;
209
210         /* special case for hid_descr_cmd */
211         if (command == &hid_descr_cmd) {
212                 cmd->c.reg = ihid->wHIDDescRegister;
213         } else {
214                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
215                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
216         }
217
218         if (length > 2) {
219                 cmd->c.opcode = command->opcode;
220                 cmd->c.reportTypeID = reportID | reportType << 4;
221         }
222
223         memcpy(cmd->data + length, args, args_len);
224         length += args_len;
225
226         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
227
228         msg[0].addr = client->addr;
229         msg[0].flags = client->flags & I2C_M_TEN;
230         msg[0].len = length;
231         msg[0].buf = cmd->data;
232         if (data_len > 0) {
233                 msg[1].addr = client->addr;
234                 msg[1].flags = client->flags & I2C_M_TEN;
235                 msg[1].flags |= I2C_M_RD;
236                 msg[1].len = data_len;
237                 msg[1].buf = buf_recv;
238                 msg_num = 2;
239                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
240         }
241
242         if (wait)
243                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
244
245         ret = i2c_transfer(client->adapter, msg, msg_num);
246
247         if (data_len > 0)
248                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
249
250         if (ret != msg_num)
251                 return ret < 0 ? ret : -EIO;
252
253         ret = 0;
254
255         if (wait) {
256                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
257                 if (!wait_event_timeout(ihid->wait,
258                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
259                                 msecs_to_jiffies(5000)))
260                         ret = -ENODATA;
261                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
262         }
263
264         return ret;
265 }
266
267 static int i2c_hid_command(struct i2c_client *client,
268                 const struct i2c_hid_cmd *command,
269                 unsigned char *buf_recv, int data_len)
270 {
271         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
272                                 buf_recv, data_len);
273 }
274
275 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
276                 u8 reportID, unsigned char *buf_recv, int data_len)
277 {
278         struct i2c_hid *ihid = i2c_get_clientdata(client);
279         u8 args[3];
280         int ret;
281         int args_len = 0;
282         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
283
284         i2c_hid_dbg(ihid, "%s\n", __func__);
285
286         if (reportID >= 0x0F) {
287                 args[args_len++] = reportID;
288                 reportID = 0x0F;
289         }
290
291         args[args_len++] = readRegister & 0xFF;
292         args[args_len++] = readRegister >> 8;
293
294         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
295                 reportType, args, args_len, buf_recv, data_len);
296         if (ret) {
297                 dev_err(&client->dev,
298                         "failed to retrieve report from device.\n");
299                 return ret;
300         }
301
302         return 0;
303 }
304
305 /**
306  * i2c_hid_set_or_send_report: forward an incoming report to the device
307  * @client: the i2c_client of the device
308  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
309  * @reportID: the report ID
310  * @buf: the actual data to transfer, without the report ID
311  * @len: size of buf
312  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
313  */
314 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
315                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
316 {
317         struct i2c_hid *ihid = i2c_get_clientdata(client);
318         u8 *args = ihid->argsbuf;
319         const struct i2c_hid_cmd *hidcmd;
320         int ret;
321         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
322         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
323         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
324         u16 size;
325         int args_len;
326         int index = 0;
327
328         i2c_hid_dbg(ihid, "%s\n", __func__);
329
330         if (data_len > ihid->bufsize)
331                 return -EINVAL;
332
333         size =          2                       /* size */ +
334                         (reportID ? 1 : 0)      /* reportID */ +
335                         data_len                /* buf */;
336         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
337                         2                       /* dataRegister */ +
338                         size                    /* args */;
339
340         if (!use_data && maxOutputLength == 0)
341                 return -ENOSYS;
342
343         if (reportID >= 0x0F) {
344                 args[index++] = reportID;
345                 reportID = 0x0F;
346         }
347
348         /*
349          * use the data register for feature reports or if the device does not
350          * support the output register
351          */
352         if (use_data) {
353                 args[index++] = dataRegister & 0xFF;
354                 args[index++] = dataRegister >> 8;
355                 hidcmd = &hid_set_report_cmd;
356         } else {
357                 args[index++] = outputRegister & 0xFF;
358                 args[index++] = outputRegister >> 8;
359                 hidcmd = &hid_no_cmd;
360         }
361
362         args[index++] = size & 0xFF;
363         args[index++] = size >> 8;
364
365         if (reportID)
366                 args[index++] = reportID;
367
368         memcpy(&args[index], buf, data_len);
369
370         ret = __i2c_hid_command(client, hidcmd, reportID,
371                 reportType, args, args_len, NULL, 0);
372         if (ret) {
373                 dev_err(&client->dev, "failed to set a report to device.\n");
374                 return ret;
375         }
376
377         return data_len;
378 }
379
380 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
381 {
382         struct i2c_hid *ihid = i2c_get_clientdata(client);
383         int ret;
384
385         i2c_hid_dbg(ihid, "%s\n", __func__);
386
387         /*
388          * Some devices require to send a command to wakeup before power on.
389          * The call will get a return value (EREMOTEIO) but device will be
390          * triggered and activated. After that, it goes like a normal device.
391          */
392         if (power_state == I2C_HID_PWR_ON &&
393             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
394                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
395
396                 /* Device was already activated */
397                 if (!ret)
398                         goto set_pwr_exit;
399         }
400
401         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
402                 0, NULL, 0, NULL, 0);
403
404         if (ret)
405                 dev_err(&client->dev, "failed to change power setting.\n");
406
407 set_pwr_exit:
408         return ret;
409 }
410
411 static int i2c_hid_hwreset(struct i2c_client *client)
412 {
413         struct i2c_hid *ihid = i2c_get_clientdata(client);
414         int ret;
415
416         i2c_hid_dbg(ihid, "%s\n", __func__);
417
418         /*
419          * This prevents sending feature reports while the device is
420          * being reset. Otherwise we may lose the reset complete
421          * interrupt.
422          */
423         mutex_lock(&ihid->reset_lock);
424
425         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
426         if (ret)
427                 goto out_unlock;
428
429         /*
430          * The HID over I2C specification states that if a DEVICE needs time
431          * after the PWR_ON request, it should utilise CLOCK stretching.
432          * However, it has been observered that the Windows driver provides a
433          * 1ms sleep between the PWR_ON and RESET requests and that some devices
434          * rely on this.
435          */
436         usleep_range(1000, 5000);
437
438         i2c_hid_dbg(ihid, "resetting...\n");
439
440         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
441         if (ret) {
442                 dev_err(&client->dev, "failed to reset device.\n");
443                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
444         }
445
446 out_unlock:
447         mutex_unlock(&ihid->reset_lock);
448         return ret;
449 }
450
451 static void i2c_hid_get_input(struct i2c_hid *ihid)
452 {
453         int ret, ret_size;
454         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
455
456         if (size > ihid->bufsize)
457                 size = ihid->bufsize;
458
459         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
460         if (ret != size) {
461                 if (ret < 0)
462                         return;
463
464                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
465                         __func__, ret, size);
466                 return;
467         }
468
469         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
470
471         if (!ret_size) {
472                 /* host or device initiated RESET completed */
473                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
474                         wake_up(&ihid->wait);
475                 return;
476         }
477
478         if (ret_size > size) {
479                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
480                         __func__, size, ret_size);
481                 return;
482         }
483
484         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
485
486         if (test_bit(I2C_HID_STARTED, &ihid->flags))
487                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
488                                 ret_size - 2, 1);
489
490         return;
491 }
492
493 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
494 {
495         struct i2c_hid *ihid = dev_id;
496
497         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
498                 return IRQ_HANDLED;
499
500         i2c_hid_get_input(ihid);
501
502         return IRQ_HANDLED;
503 }
504
505 static int i2c_hid_get_report_length(struct hid_report *report)
506 {
507         return ((report->size - 1) >> 3) + 1 +
508                 report->device->report_enum[report->type].numbered + 2;
509 }
510
511 /*
512  * Traverse the supplied list of reports and find the longest
513  */
514 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
515                 unsigned int *max)
516 {
517         struct hid_report *report;
518         unsigned int size;
519
520         /* We should not rely on wMaxInputLength, as some devices may set it to
521          * a wrong length. */
522         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
523                 size = i2c_hid_get_report_length(report);
524                 if (*max < size)
525                         *max = size;
526         }
527 }
528
529 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
530 {
531         kfree(ihid->inbuf);
532         kfree(ihid->rawbuf);
533         kfree(ihid->argsbuf);
534         kfree(ihid->cmdbuf);
535         ihid->inbuf = NULL;
536         ihid->rawbuf = NULL;
537         ihid->cmdbuf = NULL;
538         ihid->argsbuf = NULL;
539         ihid->bufsize = 0;
540 }
541
542 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
543 {
544         /* the worst case is computed from the set_report command with a
545          * reportID > 15 and the maximum report length */
546         int args_len = sizeof(__u8) + /* optional ReportID byte */
547                        sizeof(__u16) + /* data register */
548                        sizeof(__u16) + /* size of the report */
549                        report_size; /* report */
550
551         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
552         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
553         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
554         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
555
556         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
557                 i2c_hid_free_buffers(ihid);
558                 return -ENOMEM;
559         }
560
561         ihid->bufsize = report_size;
562
563         return 0;
564 }
565
566 static int i2c_hid_get_raw_report(struct hid_device *hid,
567                 unsigned char report_number, __u8 *buf, size_t count,
568                 unsigned char report_type)
569 {
570         struct i2c_client *client = hid->driver_data;
571         struct i2c_hid *ihid = i2c_get_clientdata(client);
572         size_t ret_count, ask_count;
573         int ret;
574
575         if (report_type == HID_OUTPUT_REPORT)
576                 return -EINVAL;
577
578         /* +2 bytes to include the size of the reply in the query buffer */
579         ask_count = min(count + 2, (size_t)ihid->bufsize);
580
581         ret = i2c_hid_get_report(client,
582                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
583                         report_number, ihid->rawbuf, ask_count);
584
585         if (ret < 0)
586                 return ret;
587
588         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
589
590         if (ret_count <= 2)
591                 return 0;
592
593         ret_count = min(ret_count, ask_count);
594
595         /* The query buffer contains the size, dropping it in the reply */
596         count = min(count, ret_count - 2);
597         memcpy(buf, ihid->rawbuf + 2, count);
598
599         return count;
600 }
601
602 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
603                 size_t count, unsigned char report_type, bool use_data)
604 {
605         struct i2c_client *client = hid->driver_data;
606         struct i2c_hid *ihid = i2c_get_clientdata(client);
607         int report_id = buf[0];
608         int ret;
609
610         if (report_type == HID_INPUT_REPORT)
611                 return -EINVAL;
612
613         mutex_lock(&ihid->reset_lock);
614
615         if (report_id) {
616                 buf++;
617                 count--;
618         }
619
620         ret = i2c_hid_set_or_send_report(client,
621                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
622                                 report_id, buf, count, use_data);
623
624         if (report_id && ret >= 0)
625                 ret++; /* add report_id to the number of transfered bytes */
626
627         mutex_unlock(&ihid->reset_lock);
628
629         return ret;
630 }
631
632 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
633                 size_t count)
634 {
635         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
636                         false);
637 }
638
639 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
640                                __u8 *buf, size_t len, unsigned char rtype,
641                                int reqtype)
642 {
643         switch (reqtype) {
644         case HID_REQ_GET_REPORT:
645                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
646         case HID_REQ_SET_REPORT:
647                 if (buf[0] != reportnum)
648                         return -EINVAL;
649                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
650         default:
651                 return -EIO;
652         }
653 }
654
655 static int i2c_hid_parse(struct hid_device *hid)
656 {
657         struct i2c_client *client = hid->driver_data;
658         struct i2c_hid *ihid = i2c_get_clientdata(client);
659         struct i2c_hid_desc *hdesc = &ihid->hdesc;
660         unsigned int rsize;
661         char *rdesc;
662         int ret;
663         int tries = 3;
664
665         i2c_hid_dbg(ihid, "entering %s\n", __func__);
666
667         rsize = le16_to_cpu(hdesc->wReportDescLength);
668         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
669                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
670                 return -EINVAL;
671         }
672
673         do {
674                 ret = i2c_hid_hwreset(client);
675                 if (ret)
676                         msleep(1000);
677         } while (tries-- > 0 && ret);
678
679         if (ret)
680                 return ret;
681
682         rdesc = kzalloc(rsize, GFP_KERNEL);
683
684         if (!rdesc) {
685                 dbg_hid("couldn't allocate rdesc memory\n");
686                 return -ENOMEM;
687         }
688
689         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
690
691         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
692         if (ret) {
693                 hid_err(hid, "reading report descriptor failed\n");
694                 kfree(rdesc);
695                 return -EIO;
696         }
697
698         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
699
700         ret = hid_parse_report(hid, rdesc, rsize);
701         kfree(rdesc);
702         if (ret) {
703                 dbg_hid("parsing report descriptor failed\n");
704                 return ret;
705         }
706
707         return 0;
708 }
709
710 static int i2c_hid_start(struct hid_device *hid)
711 {
712         struct i2c_client *client = hid->driver_data;
713         struct i2c_hid *ihid = i2c_get_clientdata(client);
714         int ret;
715         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
716
717         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
718         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
719         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
720
721         if (bufsize > ihid->bufsize) {
722                 disable_irq(client->irq);
723                 i2c_hid_free_buffers(ihid);
724
725                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
726                 enable_irq(client->irq);
727
728                 if (ret)
729                         return ret;
730         }
731
732         return 0;
733 }
734
735 static void i2c_hid_stop(struct hid_device *hid)
736 {
737         hid->claimed = 0;
738 }
739
740 static int i2c_hid_open(struct hid_device *hid)
741 {
742         struct i2c_client *client = hid->driver_data;
743         struct i2c_hid *ihid = i2c_get_clientdata(client);
744         int ret = 0;
745
746         mutex_lock(&i2c_hid_open_mut);
747         if (!hid->open++) {
748                 ret = pm_runtime_get_sync(&client->dev);
749                 if (ret < 0) {
750                         hid->open--;
751                         goto done;
752                 }
753                 set_bit(I2C_HID_STARTED, &ihid->flags);
754         }
755 done:
756         mutex_unlock(&i2c_hid_open_mut);
757         return ret < 0 ? ret : 0;
758 }
759
760 static void i2c_hid_close(struct hid_device *hid)
761 {
762         struct i2c_client *client = hid->driver_data;
763         struct i2c_hid *ihid = i2c_get_clientdata(client);
764
765         /* protecting hid->open to make sure we don't restart
766          * data acquistion due to a resumption we no longer
767          * care about
768          */
769         mutex_lock(&i2c_hid_open_mut);
770         if (!--hid->open) {
771                 clear_bit(I2C_HID_STARTED, &ihid->flags);
772
773                 /* Save some power */
774                 pm_runtime_put(&client->dev);
775         }
776         mutex_unlock(&i2c_hid_open_mut);
777 }
778
779 static int i2c_hid_power(struct hid_device *hid, int lvl)
780 {
781         struct i2c_client *client = hid->driver_data;
782         struct i2c_hid *ihid = i2c_get_clientdata(client);
783
784         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
785
786         switch (lvl) {
787         case PM_HINT_FULLON:
788                 pm_runtime_get_sync(&client->dev);
789                 break;
790         case PM_HINT_NORMAL:
791                 pm_runtime_put(&client->dev);
792                 break;
793         }
794         return 0;
795 }
796
797 static struct hid_ll_driver i2c_hid_ll_driver = {
798         .parse = i2c_hid_parse,
799         .start = i2c_hid_start,
800         .stop = i2c_hid_stop,
801         .open = i2c_hid_open,
802         .close = i2c_hid_close,
803         .power = i2c_hid_power,
804         .output_report = i2c_hid_output_report,
805         .raw_request = i2c_hid_raw_request,
806 };
807
808 static int i2c_hid_init_irq(struct i2c_client *client)
809 {
810         struct i2c_hid *ihid = i2c_get_clientdata(client);
811         unsigned long irqflags = 0;
812         int ret;
813
814         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
815
816         if (!irq_get_trigger_type(client->irq))
817                 irqflags = IRQF_TRIGGER_LOW;
818
819         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
820                                    irqflags | IRQF_ONESHOT, client->name, ihid);
821         if (ret < 0) {
822                 dev_warn(&client->dev,
823                         "Could not register for %s interrupt, irq = %d,"
824                         " ret = %d\n",
825                         client->name, client->irq, ret);
826
827                 return ret;
828         }
829
830         return 0;
831 }
832
833 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
834 {
835         struct i2c_client *client = ihid->client;
836         struct i2c_hid_desc *hdesc = &ihid->hdesc;
837         unsigned int dsize;
838         int ret;
839
840         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
841         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
842         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
843                                 sizeof(struct i2c_hid_desc));
844         if (ret) {
845                 dev_err(&client->dev, "hid_descr_cmd failed\n");
846                 return -ENODEV;
847         }
848
849         /* Validate the length of HID descriptor, the 4 first bytes:
850          * bytes 0-1 -> length
851          * bytes 2-3 -> bcdVersion (has to be 1.00) */
852         /* check bcdVersion == 1.0 */
853         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
854                 dev_err(&client->dev,
855                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
856                         le16_to_cpu(hdesc->bcdVersion));
857                 return -ENODEV;
858         }
859
860         /* Descriptor length should be 30 bytes as per the specification */
861         dsize = le16_to_cpu(hdesc->wHIDDescLength);
862         if (dsize != sizeof(struct i2c_hid_desc)) {
863                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
864                         dsize);
865                 return -ENODEV;
866         }
867         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
868         return 0;
869 }
870
871 #ifdef CONFIG_ACPI
872 static int i2c_hid_acpi_pdata(struct i2c_client *client,
873                 struct i2c_hid_platform_data *pdata)
874 {
875         static u8 i2c_hid_guid[] = {
876                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
877                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
878         };
879         union acpi_object *obj;
880         struct acpi_device *adev;
881         acpi_handle handle;
882
883         handle = ACPI_HANDLE(&client->dev);
884         if (!handle || acpi_bus_get_device(handle, &adev))
885                 return -ENODEV;
886
887         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
888                                       ACPI_TYPE_INTEGER);
889         if (!obj) {
890                 dev_err(&client->dev, "device _DSM execution failed\n");
891                 return -ENODEV;
892         }
893
894         pdata->hid_descriptor_address = obj->integer.value;
895         ACPI_FREE(obj);
896
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         if (client->irq < 0) {
968                 if (client->irq != -EPROBE_DEFER)
969                         dev_err(&client->dev,
970                                 "HID over i2c doesn't have a valid IRQ\n");
971                 return client->irq;
972         }
973
974         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
975         if (!ihid)
976                 return -ENOMEM;
977
978         if (client->dev.of_node) {
979                 ret = i2c_hid_of_probe(client, &ihid->pdata);
980                 if (ret)
981                         goto err;
982         } else if (!platform_data) {
983                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
984                 if (ret) {
985                         dev_err(&client->dev,
986                                 "HID register address not provided\n");
987                         goto err;
988                 }
989         } else {
990                 ihid->pdata = *platform_data;
991         }
992
993         i2c_set_clientdata(client, ihid);
994
995         ihid->client = client;
996
997         hidRegister = ihid->pdata.hid_descriptor_address;
998         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
999
1000         init_waitqueue_head(&ihid->wait);
1001         mutex_init(&ihid->reset_lock);
1002
1003         /* we need to allocate the command buffer without knowing the maximum
1004          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1005          * real computation later. */
1006         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1007         if (ret < 0)
1008                 goto err;
1009
1010         pm_runtime_get_noresume(&client->dev);
1011         pm_runtime_set_active(&client->dev);
1012         pm_runtime_enable(&client->dev);
1013         device_enable_async_suspend(&client->dev);
1014
1015         ret = i2c_hid_fetch_hid_descriptor(ihid);
1016         if (ret < 0)
1017                 goto err_pm;
1018
1019         ret = i2c_hid_init_irq(client);
1020         if (ret < 0)
1021                 goto err_pm;
1022
1023         hid = hid_allocate_device();
1024         if (IS_ERR(hid)) {
1025                 ret = PTR_ERR(hid);
1026                 goto err_irq;
1027         }
1028
1029         ihid->hid = hid;
1030
1031         hid->driver_data = client;
1032         hid->ll_driver = &i2c_hid_ll_driver;
1033         hid->dev.parent = &client->dev;
1034         hid->bus = BUS_I2C;
1035         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1036         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1037         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1038
1039         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1040                  client->name, hid->vendor, hid->product);
1041         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1042
1043         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1044
1045         ret = hid_add_device(hid);
1046         if (ret) {
1047                 if (ret != -ENODEV)
1048                         hid_err(client, "can't add hid device: %d\n", ret);
1049                 goto err_mem_free;
1050         }
1051
1052         pm_runtime_put(&client->dev);
1053         return 0;
1054
1055 err_mem_free:
1056         hid_destroy_device(hid);
1057
1058 err_irq:
1059         free_irq(client->irq, ihid);
1060
1061 err_pm:
1062         pm_runtime_put_noidle(&client->dev);
1063         pm_runtime_disable(&client->dev);
1064
1065 err:
1066         i2c_hid_free_buffers(ihid);
1067         kfree(ihid);
1068         return ret;
1069 }
1070
1071 static int i2c_hid_remove(struct i2c_client *client)
1072 {
1073         struct i2c_hid *ihid = i2c_get_clientdata(client);
1074         struct hid_device *hid;
1075
1076         pm_runtime_get_sync(&client->dev);
1077         pm_runtime_disable(&client->dev);
1078         pm_runtime_set_suspended(&client->dev);
1079         pm_runtime_put_noidle(&client->dev);
1080
1081         hid = ihid->hid;
1082         hid_destroy_device(hid);
1083
1084         free_irq(client->irq, ihid);
1085
1086         if (ihid->bufsize)
1087                 i2c_hid_free_buffers(ihid);
1088
1089         kfree(ihid);
1090
1091         return 0;
1092 }
1093
1094 static void i2c_hid_shutdown(struct i2c_client *client)
1095 {
1096         struct i2c_hid *ihid = i2c_get_clientdata(client);
1097
1098         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1099         free_irq(client->irq, ihid);
1100 }
1101
1102 #ifdef CONFIG_PM_SLEEP
1103 static int i2c_hid_suspend(struct device *dev)
1104 {
1105         struct i2c_client *client = to_i2c_client(dev);
1106         struct i2c_hid *ihid = i2c_get_clientdata(client);
1107         struct hid_device *hid = ihid->hid;
1108         int ret;
1109         int wake_status;
1110
1111         if (hid->driver && hid->driver->suspend) {
1112                 /*
1113                  * Wake up the device so that IO issues in
1114                  * HID driver's suspend code can succeed.
1115                  */
1116                 ret = pm_runtime_resume(dev);
1117                 if (ret < 0)
1118                         return ret;
1119
1120                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1121                 if (ret < 0)
1122                         return ret;
1123         }
1124
1125         if (!pm_runtime_suspended(dev)) {
1126                 /* Save some power */
1127                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1128
1129                 disable_irq(client->irq);
1130         }
1131
1132         if (device_may_wakeup(&client->dev)) {
1133                 wake_status = enable_irq_wake(client->irq);
1134                 if (!wake_status)
1135                         ihid->irq_wake_enabled = true;
1136                 else
1137                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1138                                 wake_status);
1139         }
1140
1141         return 0;
1142 }
1143
1144 static int i2c_hid_resume(struct device *dev)
1145 {
1146         int ret;
1147         struct i2c_client *client = to_i2c_client(dev);
1148         struct i2c_hid *ihid = i2c_get_clientdata(client);
1149         struct hid_device *hid = ihid->hid;
1150         int wake_status;
1151
1152         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1153                 wake_status = disable_irq_wake(client->irq);
1154                 if (!wake_status)
1155                         ihid->irq_wake_enabled = false;
1156                 else
1157                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1158                                 wake_status);
1159         }
1160
1161         /* We'll resume to full power */
1162         pm_runtime_disable(dev);
1163         pm_runtime_set_active(dev);
1164         pm_runtime_enable(dev);
1165
1166         enable_irq(client->irq);
1167         ret = i2c_hid_hwreset(client);
1168         if (ret)
1169                 return ret;
1170
1171         if (hid->driver && hid->driver->reset_resume) {
1172                 ret = hid->driver->reset_resume(hid);
1173                 return ret;
1174         }
1175
1176         return 0;
1177 }
1178 #endif
1179
1180 #ifdef CONFIG_PM
1181 static int i2c_hid_runtime_suspend(struct device *dev)
1182 {
1183         struct i2c_client *client = to_i2c_client(dev);
1184
1185         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1186         disable_irq(client->irq);
1187         return 0;
1188 }
1189
1190 static int i2c_hid_runtime_resume(struct device *dev)
1191 {
1192         struct i2c_client *client = to_i2c_client(dev);
1193
1194         enable_irq(client->irq);
1195         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1196         return 0;
1197 }
1198 #endif
1199
1200 static const struct dev_pm_ops i2c_hid_pm = {
1201         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1202         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1203                            NULL)
1204 };
1205
1206 static const struct i2c_device_id i2c_hid_id_table[] = {
1207         { "hid", 0 },
1208         { "hid-over-i2c", 0 },
1209         { },
1210 };
1211 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1212
1213
1214 static struct i2c_driver i2c_hid_driver = {
1215         .driver = {
1216                 .name   = "i2c_hid",
1217                 .pm     = &i2c_hid_pm,
1218                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1219                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1220         },
1221
1222         .probe          = i2c_hid_probe,
1223         .remove         = i2c_hid_remove,
1224         .shutdown       = i2c_hid_shutdown,
1225         .id_table       = i2c_hid_id_table,
1226 };
1227
1228 module_i2c_driver(i2c_hid_driver);
1229
1230 MODULE_DESCRIPTION("HID over I2C core driver");
1231 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1232 MODULE_LICENSE("GPL");