Merge branches 'for-4.16/upstream' and 'for-4.15/upstream-fixes' into for-linus
[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/platform_data/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 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET        BIT(1)
50
51 /* flags */
52 #define I2C_HID_STARTED         0
53 #define I2C_HID_RESET_PENDING   1
54 #define I2C_HID_READ_PENDING    2
55
56 #define I2C_HID_PWR_ON          0x00
57 #define I2C_HID_PWR_SLEEP       0x01
58
59 /* debug option */
60 static bool debug;
61 module_param(debug, bool, 0444);
62 MODULE_PARM_DESC(debug, "print a lot of debug information");
63
64 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
65 do {                                                                      \
66         if (debug)                                                        \
67                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
68 } while (0)
69
70 struct i2c_hid_desc {
71         __le16 wHIDDescLength;
72         __le16 bcdVersion;
73         __le16 wReportDescLength;
74         __le16 wReportDescRegister;
75         __le16 wInputRegister;
76         __le16 wMaxInputLength;
77         __le16 wOutputRegister;
78         __le16 wMaxOutputLength;
79         __le16 wCommandRegister;
80         __le16 wDataRegister;
81         __le16 wVendorID;
82         __le16 wProductID;
83         __le16 wVersionID;
84         __le32 reserved;
85 } __packed;
86
87 struct i2c_hid_cmd {
88         unsigned int registerIndex;
89         __u8 opcode;
90         unsigned int length;
91         bool wait;
92 };
93
94 union command {
95         u8 data[0];
96         struct cmd {
97                 __le16 reg;
98                 __u8 reportTypeID;
99                 __u8 opcode;
100         } __packed c;
101 };
102
103 #define I2C_HID_CMD(opcode_) \
104         .opcode = opcode_, .length = 4, \
105         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
106
107 /* fetch HID descriptor */
108 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
109 /* fetch report descriptors */
110 static const struct i2c_hid_cmd hid_report_descr_cmd = {
111                 .registerIndex = offsetof(struct i2c_hid_desc,
112                         wReportDescRegister),
113                 .opcode = 0x00,
114                 .length = 2 };
115 /* commands */
116 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
117                                                           .wait = true };
118 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
119 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
120 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
121 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
122
123 /*
124  * These definitions are not used here, but are defined by the spec.
125  * Keeping them here for documentation purposes.
126  *
127  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
128  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
129  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
130  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
131  */
132
133 static DEFINE_MUTEX(i2c_hid_open_mut);
134
135 /* The main device structure */
136 struct i2c_hid {
137         struct i2c_client       *client;        /* i2c client */
138         struct hid_device       *hid;   /* pointer to corresponding HID dev */
139         union {
140                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
141                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
142         };
143         __le16                  wHIDDescRegister; /* location of the i2c
144                                                    * register of the HID
145                                                    * descriptor. */
146         unsigned int            bufsize;        /* i2c buffer size */
147         char                    *inbuf;         /* Input buffer */
148         char                    *rawbuf;        /* Raw Input buffer */
149         char                    *cmdbuf;        /* Command buffer */
150         char                    *argsbuf;       /* Command arguments buffer */
151
152         unsigned long           flags;          /* device flags */
153         unsigned long           quirks;         /* Various quirks */
154
155         wait_queue_head_t       wait;           /* For waiting the interrupt */
156
157         struct i2c_hid_platform_data pdata;
158
159         bool                    irq_wake_enabled;
160         struct mutex            reset_lock;
161 };
162
163 static const struct i2c_hid_quirks {
164         __u16 idVendor;
165         __u16 idProduct;
166         __u32 quirks;
167 } i2c_hid_quirks[] = {
168         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
169                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
170         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
171                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
172         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
173                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
174         { 0, 0 }
175 };
176
177 /*
178  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
179  * @idVendor: the 16-bit vendor ID
180  * @idProduct: the 16-bit product ID
181  *
182  * Returns: a u32 quirks value.
183  */
184 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
185 {
186         u32 quirks = 0;
187         int n;
188
189         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
190                 if (i2c_hid_quirks[n].idVendor == idVendor &&
191                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
192                      i2c_hid_quirks[n].idProduct == idProduct))
193                         quirks = i2c_hid_quirks[n].quirks;
194
195         return quirks;
196 }
197
198 static int __i2c_hid_command(struct i2c_client *client,
199                 const struct i2c_hid_cmd *command, u8 reportID,
200                 u8 reportType, u8 *args, int args_len,
201                 unsigned char *buf_recv, int data_len)
202 {
203         struct i2c_hid *ihid = i2c_get_clientdata(client);
204         union command *cmd = (union command *)ihid->cmdbuf;
205         int ret;
206         struct i2c_msg msg[2];
207         int msg_num = 1;
208
209         int length = command->length;
210         bool wait = command->wait;
211         unsigned int registerIndex = command->registerIndex;
212
213         /* special case for hid_descr_cmd */
214         if (command == &hid_descr_cmd) {
215                 cmd->c.reg = ihid->wHIDDescRegister;
216         } else {
217                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
218                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
219         }
220
221         if (length > 2) {
222                 cmd->c.opcode = command->opcode;
223                 cmd->c.reportTypeID = reportID | reportType << 4;
224         }
225
226         memcpy(cmd->data + length, args, args_len);
227         length += args_len;
228
229         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
230
231         msg[0].addr = client->addr;
232         msg[0].flags = client->flags & I2C_M_TEN;
233         msg[0].len = length;
234         msg[0].buf = cmd->data;
235         if (data_len > 0) {
236                 msg[1].addr = client->addr;
237                 msg[1].flags = client->flags & I2C_M_TEN;
238                 msg[1].flags |= I2C_M_RD;
239                 msg[1].len = data_len;
240                 msg[1].buf = buf_recv;
241                 msg_num = 2;
242                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
243         }
244
245         if (wait)
246                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
247
248         ret = i2c_transfer(client->adapter, msg, msg_num);
249
250         if (data_len > 0)
251                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
252
253         if (ret != msg_num)
254                 return ret < 0 ? ret : -EIO;
255
256         ret = 0;
257
258         if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
259                 msleep(100);
260         } else if (wait) {
261                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
262                 if (!wait_event_timeout(ihid->wait,
263                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
264                                 msecs_to_jiffies(5000)))
265                         ret = -ENODATA;
266                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
267         }
268
269         return ret;
270 }
271
272 static int i2c_hid_command(struct i2c_client *client,
273                 const struct i2c_hid_cmd *command,
274                 unsigned char *buf_recv, int data_len)
275 {
276         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
277                                 buf_recv, data_len);
278 }
279
280 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
281                 u8 reportID, unsigned char *buf_recv, int data_len)
282 {
283         struct i2c_hid *ihid = i2c_get_clientdata(client);
284         u8 args[3];
285         int ret;
286         int args_len = 0;
287         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
288
289         i2c_hid_dbg(ihid, "%s\n", __func__);
290
291         if (reportID >= 0x0F) {
292                 args[args_len++] = reportID;
293                 reportID = 0x0F;
294         }
295
296         args[args_len++] = readRegister & 0xFF;
297         args[args_len++] = readRegister >> 8;
298
299         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
300                 reportType, args, args_len, buf_recv, data_len);
301         if (ret) {
302                 dev_err(&client->dev,
303                         "failed to retrieve report from device.\n");
304                 return ret;
305         }
306
307         return 0;
308 }
309
310 /**
311  * i2c_hid_set_or_send_report: forward an incoming report to the device
312  * @client: the i2c_client of the device
313  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
314  * @reportID: the report ID
315  * @buf: the actual data to transfer, without the report ID
316  * @len: size of buf
317  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
318  */
319 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
320                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
321 {
322         struct i2c_hid *ihid = i2c_get_clientdata(client);
323         u8 *args = ihid->argsbuf;
324         const struct i2c_hid_cmd *hidcmd;
325         int ret;
326         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
327         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
328         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
329         u16 size;
330         int args_len;
331         int index = 0;
332
333         i2c_hid_dbg(ihid, "%s\n", __func__);
334
335         if (data_len > ihid->bufsize)
336                 return -EINVAL;
337
338         size =          2                       /* size */ +
339                         (reportID ? 1 : 0)      /* reportID */ +
340                         data_len                /* buf */;
341         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
342                         2                       /* dataRegister */ +
343                         size                    /* args */;
344
345         if (!use_data && maxOutputLength == 0)
346                 return -ENOSYS;
347
348         if (reportID >= 0x0F) {
349                 args[index++] = reportID;
350                 reportID = 0x0F;
351         }
352
353         /*
354          * use the data register for feature reports or if the device does not
355          * support the output register
356          */
357         if (use_data) {
358                 args[index++] = dataRegister & 0xFF;
359                 args[index++] = dataRegister >> 8;
360                 hidcmd = &hid_set_report_cmd;
361         } else {
362                 args[index++] = outputRegister & 0xFF;
363                 args[index++] = outputRegister >> 8;
364                 hidcmd = &hid_no_cmd;
365         }
366
367         args[index++] = size & 0xFF;
368         args[index++] = size >> 8;
369
370         if (reportID)
371                 args[index++] = reportID;
372
373         memcpy(&args[index], buf, data_len);
374
375         ret = __i2c_hid_command(client, hidcmd, reportID,
376                 reportType, args, args_len, NULL, 0);
377         if (ret) {
378                 dev_err(&client->dev, "failed to set a report to device.\n");
379                 return ret;
380         }
381
382         return data_len;
383 }
384
385 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
386 {
387         struct i2c_hid *ihid = i2c_get_clientdata(client);
388         int ret;
389
390         i2c_hid_dbg(ihid, "%s\n", __func__);
391
392         /*
393          * Some devices require to send a command to wakeup before power on.
394          * The call will get a return value (EREMOTEIO) but device will be
395          * triggered and activated. After that, it goes like a normal device.
396          */
397         if (power_state == I2C_HID_PWR_ON &&
398             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
399                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
400
401                 /* Device was already activated */
402                 if (!ret)
403                         goto set_pwr_exit;
404         }
405
406         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
407                 0, NULL, 0, NULL, 0);
408
409         if (ret)
410                 dev_err(&client->dev, "failed to change power setting.\n");
411
412 set_pwr_exit:
413         return ret;
414 }
415
416 static int i2c_hid_hwreset(struct i2c_client *client)
417 {
418         struct i2c_hid *ihid = i2c_get_clientdata(client);
419         int ret;
420
421         i2c_hid_dbg(ihid, "%s\n", __func__);
422
423         /*
424          * This prevents sending feature reports while the device is
425          * being reset. Otherwise we may lose the reset complete
426          * interrupt.
427          */
428         mutex_lock(&ihid->reset_lock);
429
430         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
431         if (ret)
432                 goto out_unlock;
433
434         /*
435          * The HID over I2C specification states that if a DEVICE needs time
436          * after the PWR_ON request, it should utilise CLOCK stretching.
437          * However, it has been observered that the Windows driver provides a
438          * 1ms sleep between the PWR_ON and RESET requests and that some devices
439          * rely on this.
440          */
441         usleep_range(1000, 5000);
442
443         i2c_hid_dbg(ihid, "resetting...\n");
444
445         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
446         if (ret) {
447                 dev_err(&client->dev, "failed to reset device.\n");
448                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
449         }
450
451 out_unlock:
452         mutex_unlock(&ihid->reset_lock);
453         return ret;
454 }
455
456 static void i2c_hid_get_input(struct i2c_hid *ihid)
457 {
458         int ret, ret_size;
459         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
460
461         if (size > ihid->bufsize)
462                 size = ihid->bufsize;
463
464         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
465         if (ret != size) {
466                 if (ret < 0)
467                         return;
468
469                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
470                         __func__, ret, size);
471                 return;
472         }
473
474         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
475
476         if (!ret_size) {
477                 /* host or device initiated RESET completed */
478                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
479                         wake_up(&ihid->wait);
480                 return;
481         }
482
483         if (ret_size > size) {
484                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
485                         __func__, size, ret_size);
486                 return;
487         }
488
489         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
490
491         if (test_bit(I2C_HID_STARTED, &ihid->flags))
492                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
493                                 ret_size - 2, 1);
494
495         return;
496 }
497
498 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
499 {
500         struct i2c_hid *ihid = dev_id;
501
502         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
503                 return IRQ_HANDLED;
504
505         i2c_hid_get_input(ihid);
506
507         return IRQ_HANDLED;
508 }
509
510 static int i2c_hid_get_report_length(struct hid_report *report)
511 {
512         return ((report->size - 1) >> 3) + 1 +
513                 report->device->report_enum[report->type].numbered + 2;
514 }
515
516 /*
517  * Traverse the supplied list of reports and find the longest
518  */
519 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
520                 unsigned int *max)
521 {
522         struct hid_report *report;
523         unsigned int size;
524
525         /* We should not rely on wMaxInputLength, as some devices may set it to
526          * a wrong length. */
527         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
528                 size = i2c_hid_get_report_length(report);
529                 if (*max < size)
530                         *max = size;
531         }
532 }
533
534 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
535 {
536         kfree(ihid->inbuf);
537         kfree(ihid->rawbuf);
538         kfree(ihid->argsbuf);
539         kfree(ihid->cmdbuf);
540         ihid->inbuf = NULL;
541         ihid->rawbuf = NULL;
542         ihid->cmdbuf = NULL;
543         ihid->argsbuf = NULL;
544         ihid->bufsize = 0;
545 }
546
547 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
548 {
549         /* the worst case is computed from the set_report command with a
550          * reportID > 15 and the maximum report length */
551         int args_len = sizeof(__u8) + /* ReportID */
552                        sizeof(__u8) + /* optional ReportID byte */
553                        sizeof(__u16) + /* data register */
554                        sizeof(__u16) + /* size of the report */
555                        report_size; /* report */
556
557         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
558         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
559         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
560         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
561
562         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
563                 i2c_hid_free_buffers(ihid);
564                 return -ENOMEM;
565         }
566
567         ihid->bufsize = report_size;
568
569         return 0;
570 }
571
572 static int i2c_hid_get_raw_report(struct hid_device *hid,
573                 unsigned char report_number, __u8 *buf, size_t count,
574                 unsigned char report_type)
575 {
576         struct i2c_client *client = hid->driver_data;
577         struct i2c_hid *ihid = i2c_get_clientdata(client);
578         size_t ret_count, ask_count;
579         int ret;
580
581         if (report_type == HID_OUTPUT_REPORT)
582                 return -EINVAL;
583
584         /* +2 bytes to include the size of the reply in the query buffer */
585         ask_count = min(count + 2, (size_t)ihid->bufsize);
586
587         ret = i2c_hid_get_report(client,
588                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
589                         report_number, ihid->rawbuf, ask_count);
590
591         if (ret < 0)
592                 return ret;
593
594         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
595
596         if (ret_count <= 2)
597                 return 0;
598
599         ret_count = min(ret_count, ask_count);
600
601         /* The query buffer contains the size, dropping it in the reply */
602         count = min(count, ret_count - 2);
603         memcpy(buf, ihid->rawbuf + 2, count);
604
605         return count;
606 }
607
608 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
609                 size_t count, unsigned char report_type, bool use_data)
610 {
611         struct i2c_client *client = hid->driver_data;
612         struct i2c_hid *ihid = i2c_get_clientdata(client);
613         int report_id = buf[0];
614         int ret;
615
616         if (report_type == HID_INPUT_REPORT)
617                 return -EINVAL;
618
619         mutex_lock(&ihid->reset_lock);
620
621         if (report_id) {
622                 buf++;
623                 count--;
624         }
625
626         ret = i2c_hid_set_or_send_report(client,
627                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
628                                 report_id, buf, count, use_data);
629
630         if (report_id && ret >= 0)
631                 ret++; /* add report_id to the number of transfered bytes */
632
633         mutex_unlock(&ihid->reset_lock);
634
635         return ret;
636 }
637
638 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
639                 size_t count)
640 {
641         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
642                         false);
643 }
644
645 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
646                                __u8 *buf, size_t len, unsigned char rtype,
647                                int reqtype)
648 {
649         switch (reqtype) {
650         case HID_REQ_GET_REPORT:
651                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
652         case HID_REQ_SET_REPORT:
653                 if (buf[0] != reportnum)
654                         return -EINVAL;
655                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
656         default:
657                 return -EIO;
658         }
659 }
660
661 static int i2c_hid_parse(struct hid_device *hid)
662 {
663         struct i2c_client *client = hid->driver_data;
664         struct i2c_hid *ihid = i2c_get_clientdata(client);
665         struct i2c_hid_desc *hdesc = &ihid->hdesc;
666         unsigned int rsize;
667         char *rdesc;
668         int ret;
669         int tries = 3;
670
671         i2c_hid_dbg(ihid, "entering %s\n", __func__);
672
673         rsize = le16_to_cpu(hdesc->wReportDescLength);
674         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
675                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
676                 return -EINVAL;
677         }
678
679         do {
680                 ret = i2c_hid_hwreset(client);
681                 if (ret)
682                         msleep(1000);
683         } while (tries-- > 0 && ret);
684
685         if (ret)
686                 return ret;
687
688         rdesc = kzalloc(rsize, GFP_KERNEL);
689
690         if (!rdesc) {
691                 dbg_hid("couldn't allocate rdesc memory\n");
692                 return -ENOMEM;
693         }
694
695         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
696
697         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
698         if (ret) {
699                 hid_err(hid, "reading report descriptor failed\n");
700                 kfree(rdesc);
701                 return -EIO;
702         }
703
704         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
705
706         ret = hid_parse_report(hid, rdesc, rsize);
707         kfree(rdesc);
708         if (ret) {
709                 dbg_hid("parsing report descriptor failed\n");
710                 return ret;
711         }
712
713         return 0;
714 }
715
716 static int i2c_hid_start(struct hid_device *hid)
717 {
718         struct i2c_client *client = hid->driver_data;
719         struct i2c_hid *ihid = i2c_get_clientdata(client);
720         int ret;
721         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
722
723         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
724         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
725         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
726
727         if (bufsize > ihid->bufsize) {
728                 disable_irq(client->irq);
729                 i2c_hid_free_buffers(ihid);
730
731                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
732                 enable_irq(client->irq);
733
734                 if (ret)
735                         return ret;
736         }
737
738         return 0;
739 }
740
741 static void i2c_hid_stop(struct hid_device *hid)
742 {
743         hid->claimed = 0;
744 }
745
746 static int i2c_hid_open(struct hid_device *hid)
747 {
748         struct i2c_client *client = hid->driver_data;
749         struct i2c_hid *ihid = i2c_get_clientdata(client);
750         int ret = 0;
751
752         ret = pm_runtime_get_sync(&client->dev);
753         if (ret < 0)
754                 return ret;
755
756         set_bit(I2C_HID_STARTED, &ihid->flags);
757         return 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         clear_bit(I2C_HID_STARTED, &ihid->flags);
766
767         /* Save some power */
768         pm_runtime_put(&client->dev);
769 }
770
771 static int i2c_hid_power(struct hid_device *hid, int lvl)
772 {
773         struct i2c_client *client = hid->driver_data;
774         struct i2c_hid *ihid = i2c_get_clientdata(client);
775
776         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
777
778         switch (lvl) {
779         case PM_HINT_FULLON:
780                 pm_runtime_get_sync(&client->dev);
781                 break;
782         case PM_HINT_NORMAL:
783                 pm_runtime_put(&client->dev);
784                 break;
785         }
786         return 0;
787 }
788
789 struct hid_ll_driver i2c_hid_ll_driver = {
790         .parse = i2c_hid_parse,
791         .start = i2c_hid_start,
792         .stop = i2c_hid_stop,
793         .open = i2c_hid_open,
794         .close = i2c_hid_close,
795         .power = i2c_hid_power,
796         .output_report = i2c_hid_output_report,
797         .raw_request = i2c_hid_raw_request,
798 };
799 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
800
801 static int i2c_hid_init_irq(struct i2c_client *client)
802 {
803         struct i2c_hid *ihid = i2c_get_clientdata(client);
804         unsigned long irqflags = 0;
805         int ret;
806
807         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
808
809         if (!irq_get_trigger_type(client->irq))
810                 irqflags = IRQF_TRIGGER_LOW;
811
812         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
813                                    irqflags | IRQF_ONESHOT, client->name, ihid);
814         if (ret < 0) {
815                 dev_warn(&client->dev,
816                         "Could not register for %s interrupt, irq = %d,"
817                         " ret = %d\n",
818                         client->name, client->irq, ret);
819
820                 return ret;
821         }
822
823         return 0;
824 }
825
826 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
827 {
828         struct i2c_client *client = ihid->client;
829         struct i2c_hid_desc *hdesc = &ihid->hdesc;
830         unsigned int dsize;
831         int ret;
832
833         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
834         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
835         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
836                                 sizeof(struct i2c_hid_desc));
837         if (ret) {
838                 dev_err(&client->dev, "hid_descr_cmd failed\n");
839                 return -ENODEV;
840         }
841
842         /* Validate the length of HID descriptor, the 4 first bytes:
843          * bytes 0-1 -> length
844          * bytes 2-3 -> bcdVersion (has to be 1.00) */
845         /* check bcdVersion == 1.0 */
846         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
847                 dev_err(&client->dev,
848                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
849                         le16_to_cpu(hdesc->bcdVersion));
850                 return -ENODEV;
851         }
852
853         /* Descriptor length should be 30 bytes as per the specification */
854         dsize = le16_to_cpu(hdesc->wHIDDescLength);
855         if (dsize != sizeof(struct i2c_hid_desc)) {
856                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
857                         dsize);
858                 return -ENODEV;
859         }
860         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
861         return 0;
862 }
863
864 #ifdef CONFIG_ACPI
865 static int i2c_hid_acpi_pdata(struct i2c_client *client,
866                 struct i2c_hid_platform_data *pdata)
867 {
868         static guid_t i2c_hid_guid =
869                 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
870                           0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
871         union acpi_object *obj;
872         struct acpi_device *adev;
873         acpi_handle handle;
874
875         handle = ACPI_HANDLE(&client->dev);
876         if (!handle || acpi_bus_get_device(handle, &adev))
877                 return -ENODEV;
878
879         obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
880                                       ACPI_TYPE_INTEGER);
881         if (!obj) {
882                 dev_err(&client->dev, "device _DSM execution failed\n");
883                 return -ENODEV;
884         }
885
886         pdata->hid_descriptor_address = obj->integer.value;
887         ACPI_FREE(obj);
888
889         return 0;
890 }
891
892 static void i2c_hid_acpi_fix_up_power(struct device *dev)
893 {
894         acpi_handle handle = ACPI_HANDLE(dev);
895         struct acpi_device *adev;
896
897         if (handle && acpi_bus_get_device(handle, &adev) == 0)
898                 acpi_device_fix_up_power(adev);
899 }
900
901 static const struct acpi_device_id i2c_hid_acpi_match[] = {
902         {"ACPI0C50", 0 },
903         {"PNP0C50", 0 },
904         { },
905 };
906 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
907 #else
908 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
909                 struct i2c_hid_platform_data *pdata)
910 {
911         return -ENODEV;
912 }
913
914 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {}
915 #endif
916
917 #ifdef CONFIG_OF
918 static int i2c_hid_of_probe(struct i2c_client *client,
919                 struct i2c_hid_platform_data *pdata)
920 {
921         struct device *dev = &client->dev;
922         u32 val;
923         int ret;
924
925         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
926         if (ret) {
927                 dev_err(&client->dev, "HID register address not provided\n");
928                 return -ENODEV;
929         }
930         if (val >> 16) {
931                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
932                         val);
933                 return -EINVAL;
934         }
935         pdata->hid_descriptor_address = val;
936
937         return 0;
938 }
939
940 static const struct of_device_id i2c_hid_of_match[] = {
941         { .compatible = "hid-over-i2c" },
942         {},
943 };
944 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
945 #else
946 static inline int i2c_hid_of_probe(struct i2c_client *client,
947                 struct i2c_hid_platform_data *pdata)
948 {
949         return -ENODEV;
950 }
951 #endif
952
953 static void i2c_hid_fwnode_probe(struct i2c_client *client,
954                                  struct i2c_hid_platform_data *pdata)
955 {
956         u32 val;
957
958         if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms",
959                                       &val))
960                 pdata->post_power_delay_ms = val;
961 }
962
963 static int i2c_hid_probe(struct i2c_client *client,
964                          const struct i2c_device_id *dev_id)
965 {
966         int ret;
967         struct i2c_hid *ihid;
968         struct hid_device *hid;
969         __u16 hidRegister;
970         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
971
972         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
973
974         if (!client->irq) {
975                 dev_err(&client->dev,
976                         "HID over i2c has not been provided an Int IRQ\n");
977                 return -EINVAL;
978         }
979
980         if (client->irq < 0) {
981                 if (client->irq != -EPROBE_DEFER)
982                         dev_err(&client->dev,
983                                 "HID over i2c doesn't have a valid IRQ\n");
984                 return client->irq;
985         }
986
987         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
988         if (!ihid)
989                 return -ENOMEM;
990
991         if (client->dev.of_node) {
992                 ret = i2c_hid_of_probe(client, &ihid->pdata);
993                 if (ret)
994                         goto err;
995         } else if (!platform_data) {
996                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
997                 if (ret) {
998                         dev_err(&client->dev,
999                                 "HID register address not provided\n");
1000                         goto err;
1001                 }
1002         } else {
1003                 ihid->pdata = *platform_data;
1004         }
1005
1006         /* Parse platform agnostic common properties from ACPI / device tree */
1007         i2c_hid_fwnode_probe(client, &ihid->pdata);
1008
1009         ihid->pdata.supply = devm_regulator_get(&client->dev, "vdd");
1010         if (IS_ERR(ihid->pdata.supply)) {
1011                 ret = PTR_ERR(ihid->pdata.supply);
1012                 if (ret != -EPROBE_DEFER)
1013                         dev_err(&client->dev, "Failed to get regulator: %d\n",
1014                                 ret);
1015                 goto err;
1016         }
1017
1018         ret = regulator_enable(ihid->pdata.supply);
1019         if (ret < 0) {
1020                 dev_err(&client->dev, "Failed to enable regulator: %d\n",
1021                         ret);
1022                 goto err;
1023         }
1024         if (ihid->pdata.post_power_delay_ms)
1025                 msleep(ihid->pdata.post_power_delay_ms);
1026
1027         i2c_set_clientdata(client, ihid);
1028
1029         ihid->client = client;
1030
1031         hidRegister = ihid->pdata.hid_descriptor_address;
1032         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1033
1034         init_waitqueue_head(&ihid->wait);
1035         mutex_init(&ihid->reset_lock);
1036
1037         /* we need to allocate the command buffer without knowing the maximum
1038          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1039          * real computation later. */
1040         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1041         if (ret < 0)
1042                 goto err_regulator;
1043
1044         i2c_hid_acpi_fix_up_power(&client->dev);
1045
1046         pm_runtime_get_noresume(&client->dev);
1047         pm_runtime_set_active(&client->dev);
1048         pm_runtime_enable(&client->dev);
1049         device_enable_async_suspend(&client->dev);
1050
1051         ret = i2c_hid_fetch_hid_descriptor(ihid);
1052         if (ret < 0)
1053                 goto err_pm;
1054
1055         ret = i2c_hid_init_irq(client);
1056         if (ret < 0)
1057                 goto err_pm;
1058
1059         hid = hid_allocate_device();
1060         if (IS_ERR(hid)) {
1061                 ret = PTR_ERR(hid);
1062                 goto err_irq;
1063         }
1064
1065         ihid->hid = hid;
1066
1067         hid->driver_data = client;
1068         hid->ll_driver = &i2c_hid_ll_driver;
1069         hid->dev.parent = &client->dev;
1070         hid->bus = BUS_I2C;
1071         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1072         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1073         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1074
1075         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1076                  client->name, hid->vendor, hid->product);
1077         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1078
1079         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1080
1081         ret = hid_add_device(hid);
1082         if (ret) {
1083                 if (ret != -ENODEV)
1084                         hid_err(client, "can't add hid device: %d\n", ret);
1085                 goto err_mem_free;
1086         }
1087
1088         pm_runtime_put(&client->dev);
1089         return 0;
1090
1091 err_mem_free:
1092         hid_destroy_device(hid);
1093
1094 err_irq:
1095         free_irq(client->irq, ihid);
1096
1097 err_pm:
1098         pm_runtime_put_noidle(&client->dev);
1099         pm_runtime_disable(&client->dev);
1100
1101 err_regulator:
1102         regulator_disable(ihid->pdata.supply);
1103
1104 err:
1105         i2c_hid_free_buffers(ihid);
1106         kfree(ihid);
1107         return ret;
1108 }
1109
1110 static int i2c_hid_remove(struct i2c_client *client)
1111 {
1112         struct i2c_hid *ihid = i2c_get_clientdata(client);
1113         struct hid_device *hid;
1114
1115         pm_runtime_get_sync(&client->dev);
1116         pm_runtime_disable(&client->dev);
1117         pm_runtime_set_suspended(&client->dev);
1118         pm_runtime_put_noidle(&client->dev);
1119
1120         hid = ihid->hid;
1121         hid_destroy_device(hid);
1122
1123         free_irq(client->irq, ihid);
1124
1125         if (ihid->bufsize)
1126                 i2c_hid_free_buffers(ihid);
1127
1128         regulator_disable(ihid->pdata.supply);
1129
1130         kfree(ihid);
1131
1132         return 0;
1133 }
1134
1135 static void i2c_hid_shutdown(struct i2c_client *client)
1136 {
1137         struct i2c_hid *ihid = i2c_get_clientdata(client);
1138
1139         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1140         free_irq(client->irq, ihid);
1141 }
1142
1143 #ifdef CONFIG_PM_SLEEP
1144 static int i2c_hid_suspend(struct device *dev)
1145 {
1146         struct i2c_client *client = to_i2c_client(dev);
1147         struct i2c_hid *ihid = i2c_get_clientdata(client);
1148         struct hid_device *hid = ihid->hid;
1149         int ret;
1150         int wake_status;
1151
1152         if (hid->driver && hid->driver->suspend) {
1153                 /*
1154                  * Wake up the device so that IO issues in
1155                  * HID driver's suspend code can succeed.
1156                  */
1157                 ret = pm_runtime_resume(dev);
1158                 if (ret < 0)
1159                         return ret;
1160
1161                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1162                 if (ret < 0)
1163                         return ret;
1164         }
1165
1166         if (!pm_runtime_suspended(dev)) {
1167                 /* Save some power */
1168                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1169
1170                 disable_irq(client->irq);
1171         }
1172
1173         if (device_may_wakeup(&client->dev)) {
1174                 wake_status = enable_irq_wake(client->irq);
1175                 if (!wake_status)
1176                         ihid->irq_wake_enabled = true;
1177                 else
1178                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1179                                 wake_status);
1180         } else {
1181                 ret = regulator_disable(ihid->pdata.supply);
1182                 if (ret < 0)
1183                         hid_warn(hid, "Failed to disable supply: %d\n", ret);
1184         }
1185
1186         return 0;
1187 }
1188
1189 static int i2c_hid_resume(struct device *dev)
1190 {
1191         int ret;
1192         struct i2c_client *client = to_i2c_client(dev);
1193         struct i2c_hid *ihid = i2c_get_clientdata(client);
1194         struct hid_device *hid = ihid->hid;
1195         int wake_status;
1196
1197         if (!device_may_wakeup(&client->dev)) {
1198                 ret = regulator_enable(ihid->pdata.supply);
1199                 if (ret < 0)
1200                         hid_warn(hid, "Failed to enable supply: %d\n", ret);
1201                 if (ihid->pdata.post_power_delay_ms)
1202                         msleep(ihid->pdata.post_power_delay_ms);
1203         } else if (ihid->irq_wake_enabled) {
1204                 wake_status = disable_irq_wake(client->irq);
1205                 if (!wake_status)
1206                         ihid->irq_wake_enabled = false;
1207                 else
1208                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1209                                 wake_status);
1210         }
1211
1212         /* We'll resume to full power */
1213         pm_runtime_disable(dev);
1214         pm_runtime_set_active(dev);
1215         pm_runtime_enable(dev);
1216
1217         enable_irq(client->irq);
1218         ret = i2c_hid_hwreset(client);
1219         if (ret)
1220                 return ret;
1221
1222         if (hid->driver && hid->driver->reset_resume) {
1223                 ret = hid->driver->reset_resume(hid);
1224                 return ret;
1225         }
1226
1227         return 0;
1228 }
1229 #endif
1230
1231 #ifdef CONFIG_PM
1232 static int i2c_hid_runtime_suspend(struct device *dev)
1233 {
1234         struct i2c_client *client = to_i2c_client(dev);
1235
1236         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1237         disable_irq(client->irq);
1238         return 0;
1239 }
1240
1241 static int i2c_hid_runtime_resume(struct device *dev)
1242 {
1243         struct i2c_client *client = to_i2c_client(dev);
1244
1245         enable_irq(client->irq);
1246         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1247         return 0;
1248 }
1249 #endif
1250
1251 static const struct dev_pm_ops i2c_hid_pm = {
1252         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1253         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1254                            NULL)
1255 };
1256
1257 static const struct i2c_device_id i2c_hid_id_table[] = {
1258         { "hid", 0 },
1259         { "hid-over-i2c", 0 },
1260         { },
1261 };
1262 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1263
1264
1265 static struct i2c_driver i2c_hid_driver = {
1266         .driver = {
1267                 .name   = "i2c_hid",
1268                 .pm     = &i2c_hid_pm,
1269                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1270                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1271         },
1272
1273         .probe          = i2c_hid_probe,
1274         .remove         = i2c_hid_remove,
1275         .shutdown       = i2c_hid_shutdown,
1276         .id_table       = i2c_hid_id_table,
1277 };
1278
1279 module_i2c_driver(i2c_hid_driver);
1280
1281 MODULE_DESCRIPTION("HID over I2C core driver");
1282 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1283 MODULE_LICENSE("GPL");