Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/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/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         struct mutex            reset_lock;
155 };
156 
157 static int __i2c_hid_command(struct i2c_client *client,
158                 const struct i2c_hid_cmd *command, u8 reportID,
159                 u8 reportType, u8 *args, int args_len,
160                 unsigned char *buf_recv, int data_len)
161 {
162         struct i2c_hid *ihid = i2c_get_clientdata(client);
163         union command *cmd = (union command *)ihid->cmdbuf;
164         int ret;
165         struct i2c_msg msg[2];
166         int msg_num = 1;
167 
168         int length = command->length;
169         bool wait = command->wait;
170         unsigned int registerIndex = command->registerIndex;
171 
172         /* special case for hid_descr_cmd */
173         if (command == &hid_descr_cmd) {
174                 cmd->c.reg = ihid->wHIDDescRegister;
175         } else {
176                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
177                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
178         }
179 
180         if (length > 2) {
181                 cmd->c.opcode = command->opcode;
182                 cmd->c.reportTypeID = reportID | reportType << 4;
183         }
184 
185         memcpy(cmd->data + length, args, args_len);
186         length += args_len;
187 
188         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
189 
190         msg[0].addr = client->addr;
191         msg[0].flags = client->flags & I2C_M_TEN;
192         msg[0].len = length;
193         msg[0].buf = cmd->data;
194         if (data_len > 0) {
195                 msg[1].addr = client->addr;
196                 msg[1].flags = client->flags & I2C_M_TEN;
197                 msg[1].flags |= I2C_M_RD;
198                 msg[1].len = data_len;
199                 msg[1].buf = buf_recv;
200                 msg_num = 2;
201                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
202         }
203 
204         if (wait)
205                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
206 
207         ret = i2c_transfer(client->adapter, msg, msg_num);
208 
209         if (data_len > 0)
210                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
211 
212         if (ret != msg_num)
213                 return ret < 0 ? ret : -EIO;
214 
215         ret = 0;
216 
217         if (wait) {
218                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
219                 if (!wait_event_timeout(ihid->wait,
220                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
221                                 msecs_to_jiffies(5000)))
222                         ret = -ENODATA;
223                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
224         }
225 
226         return ret;
227 }
228 
229 static int i2c_hid_command(struct i2c_client *client,
230                 const struct i2c_hid_cmd *command,
231                 unsigned char *buf_recv, int data_len)
232 {
233         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
234                                 buf_recv, data_len);
235 }
236 
237 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
238                 u8 reportID, unsigned char *buf_recv, int data_len)
239 {
240         struct i2c_hid *ihid = i2c_get_clientdata(client);
241         u8 args[3];
242         int ret;
243         int args_len = 0;
244         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
245 
246         i2c_hid_dbg(ihid, "%s\n", __func__);
247 
248         if (reportID >= 0x0F) {
249                 args[args_len++] = reportID;
250                 reportID = 0x0F;
251         }
252 
253         args[args_len++] = readRegister & 0xFF;
254         args[args_len++] = readRegister >> 8;
255 
256         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
257                 reportType, args, args_len, buf_recv, data_len);
258         if (ret) {
259                 dev_err(&client->dev,
260                         "failed to retrieve report from device.\n");
261                 return ret;
262         }
263 
264         return 0;
265 }
266 
267 /**
268  * i2c_hid_set_or_send_report: forward an incoming report to the device
269  * @client: the i2c_client of the device
270  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
271  * @reportID: the report ID
272  * @buf: the actual data to transfer, without the report ID
273  * @len: size of buf
274  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
275  */
276 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
277                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
278 {
279         struct i2c_hid *ihid = i2c_get_clientdata(client);
280         u8 *args = ihid->argsbuf;
281         const struct i2c_hid_cmd *hidcmd;
282         int ret;
283         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
284         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
285         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
286 
287         /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
288         u16 size =      2                       /* size */ +
289                         (reportID ? 1 : 0)      /* reportID */ +
290                         data_len                /* buf */;
291         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
292                         2                       /* dataRegister */ +
293                         size                    /* args */;
294         int index = 0;
295 
296         i2c_hid_dbg(ihid, "%s\n", __func__);
297 
298         if (!use_data && maxOutputLength == 0)
299                 return -ENOSYS;
300 
301         if (reportID >= 0x0F) {
302                 args[index++] = reportID;
303                 reportID = 0x0F;
304         }
305 
306         /*
307          * use the data register for feature reports or if the device does not
308          * support the output register
309          */
310         if (use_data) {
311                 args[index++] = dataRegister & 0xFF;
312                 args[index++] = dataRegister >> 8;
313                 hidcmd = &hid_set_report_cmd;
314         } else {
315                 args[index++] = outputRegister & 0xFF;
316                 args[index++] = outputRegister >> 8;
317                 hidcmd = &hid_no_cmd;
318         }
319 
320         args[index++] = size & 0xFF;
321         args[index++] = size >> 8;
322 
323         if (reportID)
324                 args[index++] = reportID;
325 
326         memcpy(&args[index], buf, data_len);
327 
328         ret = __i2c_hid_command(client, hidcmd, reportID,
329                 reportType, args, args_len, NULL, 0);
330         if (ret) {
331                 dev_err(&client->dev, "failed to set a report to device.\n");
332                 return ret;
333         }
334 
335         return data_len;
336 }
337 
338 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
339 {
340         struct i2c_hid *ihid = i2c_get_clientdata(client);
341         int ret;
342 
343         i2c_hid_dbg(ihid, "%s\n", __func__);
344 
345         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
346                 0, NULL, 0, NULL, 0);
347         if (ret)
348                 dev_err(&client->dev, "failed to change power setting.\n");
349 
350         return ret;
351 }
352 
353 static int i2c_hid_hwreset(struct i2c_client *client)
354 {
355         struct i2c_hid *ihid = i2c_get_clientdata(client);
356         int ret;
357 
358         i2c_hid_dbg(ihid, "%s\n", __func__);
359 
360         /*
361          * This prevents sending feature reports while the device is
362          * being reset. Otherwise we may lose the reset complete
363          * interrupt.
364          */
365         mutex_lock(&ihid->reset_lock);
366 
367         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
368         if (ret)
369                 goto out_unlock;
370 
371         i2c_hid_dbg(ihid, "resetting...\n");
372 
373         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
374         if (ret) {
375                 dev_err(&client->dev, "failed to reset device.\n");
376                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
377         }
378 
379 out_unlock:
380         mutex_unlock(&ihid->reset_lock);
381         return ret;
382 }
383 
384 static void i2c_hid_get_input(struct i2c_hid *ihid)
385 {
386         int ret, ret_size;
387         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
388 
389         if (size > ihid->bufsize)
390                 size = ihid->bufsize;
391 
392         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
393         if (ret != size) {
394                 if (ret < 0)
395                         return;
396 
397                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
398                         __func__, ret, size);
399                 return;
400         }
401 
402         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
403 
404         if (!ret_size) {
405                 /* host or device initiated RESET completed */
406                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
407                         wake_up(&ihid->wait);
408                 return;
409         }
410 
411         if (ret_size > size) {
412                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
413                         __func__, size, ret_size);
414                 return;
415         }
416 
417         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
418 
419         if (test_bit(I2C_HID_STARTED, &ihid->flags))
420                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
421                                 ret_size - 2, 1);
422 
423         return;
424 }
425 
426 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
427 {
428         struct i2c_hid *ihid = dev_id;
429 
430         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
431                 return IRQ_HANDLED;
432 
433         i2c_hid_get_input(ihid);
434 
435         return IRQ_HANDLED;
436 }
437 
438 static int i2c_hid_get_report_length(struct hid_report *report)
439 {
440         return ((report->size - 1) >> 3) + 1 +
441                 report->device->report_enum[report->type].numbered + 2;
442 }
443 
444 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
445         size_t bufsize)
446 {
447         struct hid_device *hid = report->device;
448         struct i2c_client *client = hid->driver_data;
449         struct i2c_hid *ihid = i2c_get_clientdata(client);
450         unsigned int size, ret_size;
451 
452         size = i2c_hid_get_report_length(report);
453         if (i2c_hid_get_report(client,
454                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
455                         report->id, buffer, size))
456                 return;
457 
458         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
459 
460         ret_size = buffer[0] | (buffer[1] << 8);
461 
462         if (ret_size != size) {
463                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
464                         __func__, size, ret_size);
465                 return;
466         }
467 
468         /* hid->driver_lock is held as we are in probe function,
469          * we just need to setup the input fields, so using
470          * hid_report_raw_event is safe. */
471         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
472 }
473 
474 /*
475  * Initialize all reports
476  */
477 static void i2c_hid_init_reports(struct hid_device *hid)
478 {
479         struct hid_report *report;
480         struct i2c_client *client = hid->driver_data;
481         struct i2c_hid *ihid = i2c_get_clientdata(client);
482         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
483 
484         if (!inbuf) {
485                 dev_err(&client->dev, "can not retrieve initial reports\n");
486                 return;
487         }
488 
489         /*
490          * The device must be powered on while we fetch initial reports
491          * from it.
492          */
493         pm_runtime_get_sync(&client->dev);
494 
495         list_for_each_entry(report,
496                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
497                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
498 
499         pm_runtime_put(&client->dev);
500 
501         kfree(inbuf);
502 }
503 
504 /*
505  * Traverse the supplied list of reports and find the longest
506  */
507 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
508                 unsigned int *max)
509 {
510         struct hid_report *report;
511         unsigned int size;
512 
513         /* We should not rely on wMaxInputLength, as some devices may set it to
514          * a wrong length. */
515         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
516                 size = i2c_hid_get_report_length(report);
517                 if (*max < size)
518                         *max = size;
519         }
520 }
521 
522 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
523 {
524         kfree(ihid->inbuf);
525         kfree(ihid->rawbuf);
526         kfree(ihid->argsbuf);
527         kfree(ihid->cmdbuf);
528         ihid->inbuf = NULL;
529         ihid->rawbuf = NULL;
530         ihid->cmdbuf = NULL;
531         ihid->argsbuf = NULL;
532         ihid->bufsize = 0;
533 }
534 
535 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
536 {
537         /* the worst case is computed from the set_report command with a
538          * reportID > 15 and the maximum report length */
539         int args_len = sizeof(__u8) + /* optional ReportID byte */
540                        sizeof(__u16) + /* data register */
541                        sizeof(__u16) + /* size of the report */
542                        report_size; /* report */
543 
544         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
545         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
546         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
547         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
548 
549         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
550                 i2c_hid_free_buffers(ihid);
551                 return -ENOMEM;
552         }
553 
554         ihid->bufsize = report_size;
555 
556         return 0;
557 }
558 
559 static int i2c_hid_get_raw_report(struct hid_device *hid,
560                 unsigned char report_number, __u8 *buf, size_t count,
561                 unsigned char report_type)
562 {
563         struct i2c_client *client = hid->driver_data;
564         struct i2c_hid *ihid = i2c_get_clientdata(client);
565         size_t ret_count, ask_count;
566         int ret;
567 
568         if (report_type == HID_OUTPUT_REPORT)
569                 return -EINVAL;
570 
571         /* +2 bytes to include the size of the reply in the query buffer */
572         ask_count = min(count + 2, (size_t)ihid->bufsize);
573 
574         ret = i2c_hid_get_report(client,
575                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
576                         report_number, ihid->rawbuf, ask_count);
577 
578         if (ret < 0)
579                 return ret;
580 
581         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
582 
583         if (ret_count <= 2)
584                 return 0;
585 
586         ret_count = min(ret_count, ask_count);
587 
588         /* The query buffer contains the size, dropping it in the reply */
589         count = min(count, ret_count - 2);
590         memcpy(buf, ihid->rawbuf + 2, count);
591 
592         return count;
593 }
594 
595 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
596                 size_t count, unsigned char report_type, bool use_data)
597 {
598         struct i2c_client *client = hid->driver_data;
599         struct i2c_hid *ihid = i2c_get_clientdata(client);
600         int report_id = buf[0];
601         int ret;
602 
603         if (report_type == HID_INPUT_REPORT)
604                 return -EINVAL;
605 
606         mutex_lock(&ihid->reset_lock);
607 
608         if (report_id) {
609                 buf++;
610                 count--;
611         }
612 
613         ret = i2c_hid_set_or_send_report(client,
614                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
615                                 report_id, buf, count, use_data);
616 
617         if (report_id && ret >= 0)
618                 ret++; /* add report_id to the number of transfered bytes */
619 
620         mutex_unlock(&ihid->reset_lock);
621 
622         return ret;
623 }
624 
625 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
626                 size_t count)
627 {
628         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
629                         false);
630 }
631 
632 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
633                                __u8 *buf, size_t len, unsigned char rtype,
634                                int reqtype)
635 {
636         switch (reqtype) {
637         case HID_REQ_GET_REPORT:
638                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
639         case HID_REQ_SET_REPORT:
640                 if (buf[0] != reportnum)
641                         return -EINVAL;
642                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
643         default:
644                 return -EIO;
645         }
646 }
647 
648 static int i2c_hid_parse(struct hid_device *hid)
649 {
650         struct i2c_client *client = hid->driver_data;
651         struct i2c_hid *ihid = i2c_get_clientdata(client);
652         struct i2c_hid_desc *hdesc = &ihid->hdesc;
653         unsigned int rsize;
654         char *rdesc;
655         int ret;
656         int tries = 3;
657 
658         i2c_hid_dbg(ihid, "entering %s\n", __func__);
659 
660         rsize = le16_to_cpu(hdesc->wReportDescLength);
661         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
662                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
663                 return -EINVAL;
664         }
665 
666         do {
667                 ret = i2c_hid_hwreset(client);
668                 if (ret)
669                         msleep(1000);
670         } while (tries-- > 0 && ret);
671 
672         if (ret)
673                 return ret;
674 
675         rdesc = kzalloc(rsize, GFP_KERNEL);
676 
677         if (!rdesc) {
678                 dbg_hid("couldn't allocate rdesc memory\n");
679                 return -ENOMEM;
680         }
681 
682         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
683 
684         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
685         if (ret) {
686                 hid_err(hid, "reading report descriptor failed\n");
687                 kfree(rdesc);
688                 return -EIO;
689         }
690 
691         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
692 
693         ret = hid_parse_report(hid, rdesc, rsize);
694         kfree(rdesc);
695         if (ret) {
696                 dbg_hid("parsing report descriptor failed\n");
697                 return ret;
698         }
699 
700         return 0;
701 }
702 
703 static int i2c_hid_start(struct hid_device *hid)
704 {
705         struct i2c_client *client = hid->driver_data;
706         struct i2c_hid *ihid = i2c_get_clientdata(client);
707         int ret;
708         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
709 
710         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
711         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
712         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
713 
714         if (bufsize > ihid->bufsize) {
715                 i2c_hid_free_buffers(ihid);
716 
717                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
718 
719                 if (ret)
720                         return ret;
721         }
722 
723         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
724                 i2c_hid_init_reports(hid);
725 
726         return 0;
727 }
728 
729 static void i2c_hid_stop(struct hid_device *hid)
730 {
731         hid->claimed = 0;
732 }
733 
734 static int i2c_hid_open(struct hid_device *hid)
735 {
736         struct i2c_client *client = hid->driver_data;
737         struct i2c_hid *ihid = i2c_get_clientdata(client);
738         int ret = 0;
739 
740         mutex_lock(&i2c_hid_open_mut);
741         if (!hid->open++) {
742                 ret = pm_runtime_get_sync(&client->dev);
743                 if (ret < 0) {
744                         hid->open--;
745                         goto done;
746                 }
747                 set_bit(I2C_HID_STARTED, &ihid->flags);
748         }
749 done:
750         mutex_unlock(&i2c_hid_open_mut);
751         return ret < 0 ? ret : 0;
752 }
753 
754 static void i2c_hid_close(struct hid_device *hid)
755 {
756         struct i2c_client *client = hid->driver_data;
757         struct i2c_hid *ihid = i2c_get_clientdata(client);
758 
759         /* protecting hid->open to make sure we don't restart
760          * data acquistion due to a resumption we no longer
761          * care about
762          */
763         mutex_lock(&i2c_hid_open_mut);
764         if (!--hid->open) {
765                 clear_bit(I2C_HID_STARTED, &ihid->flags);
766 
767                 /* Save some power */
768                 pm_runtime_put(&client->dev);
769         }
770         mutex_unlock(&i2c_hid_open_mut);
771 }
772 
773 static int i2c_hid_power(struct hid_device *hid, int lvl)
774 {
775         struct i2c_client *client = hid->driver_data;
776         struct i2c_hid *ihid = i2c_get_clientdata(client);
777 
778         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
779 
780         switch (lvl) {
781         case PM_HINT_FULLON:
782                 pm_runtime_get_sync(&client->dev);
783                 break;
784         case PM_HINT_NORMAL:
785                 pm_runtime_put(&client->dev);
786                 break;
787         }
788         return 0;
789 }
790 
791 static struct hid_ll_driver i2c_hid_ll_driver = {
792         .parse = i2c_hid_parse,
793         .start = i2c_hid_start,
794         .stop = i2c_hid_stop,
795         .open = i2c_hid_open,
796         .close = i2c_hid_close,
797         .power = i2c_hid_power,
798         .output_report = i2c_hid_output_report,
799         .raw_request = i2c_hid_raw_request,
800 };
801 
802 static int i2c_hid_init_irq(struct i2c_client *client)
803 {
804         struct i2c_hid *ihid = i2c_get_clientdata(client);
805         int ret;
806 
807         dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
808 
809         ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
810                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
811                         client->name, ihid);
812         if (ret < 0) {
813                 dev_warn(&client->dev,
814                         "Could not register for %s interrupt, irq = %d,"
815                         " ret = %d\n",
816                         client->name, ihid->irq, ret);
817 
818                 return ret;
819         }
820 
821         return 0;
822 }
823 
824 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
825 {
826         struct i2c_client *client = ihid->client;
827         struct i2c_hid_desc *hdesc = &ihid->hdesc;
828         unsigned int dsize;
829         int ret;
830 
831         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
832         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
833         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
834                                 sizeof(struct i2c_hid_desc));
835         if (ret) {
836                 dev_err(&client->dev, "hid_descr_cmd failed\n");
837                 return -ENODEV;
838         }
839 
840         /* Validate the length of HID descriptor, the 4 first bytes:
841          * bytes 0-1 -> length
842          * bytes 2-3 -> bcdVersion (has to be 1.00) */
843         /* check bcdVersion == 1.0 */
844         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
845                 dev_err(&client->dev,
846                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
847                         le16_to_cpu(hdesc->bcdVersion));
848                 return -ENODEV;
849         }
850 
851         /* Descriptor length should be 30 bytes as per the specification */
852         dsize = le16_to_cpu(hdesc->wHIDDescLength);
853         if (dsize != sizeof(struct i2c_hid_desc)) {
854                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
855                         dsize);
856                 return -ENODEV;
857         }
858         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
859         return 0;
860 }
861 
862 #ifdef CONFIG_ACPI
863 
864 /* Default GPIO mapping */
865 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
866 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
867         { "gpios", &i2c_hid_irq_gpio, 1 },
868         { },
869 };
870 
871 static int i2c_hid_acpi_pdata(struct i2c_client *client,
872                 struct i2c_hid_platform_data *pdata)
873 {
874         static u8 i2c_hid_guid[] = {
875                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
876                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
877         };
878         union acpi_object *obj;
879         struct acpi_device *adev;
880         acpi_handle handle;
881         int ret;
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         /* GPIOs are optional */
898         ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
899         return ret < 0 && ret != -ENXIO ? ret : 0;
900 }
901 
902 static const struct acpi_device_id i2c_hid_acpi_match[] = {
903         {"ACPI0C50", 0 },
904         {"PNP0C50", 0 },
905         { },
906 };
907 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
908 #else
909 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
910                 struct i2c_hid_platform_data *pdata)
911 {
912         return -ENODEV;
913 }
914 #endif
915 
916 #ifdef CONFIG_OF
917 static int i2c_hid_of_probe(struct i2c_client *client,
918                 struct i2c_hid_platform_data *pdata)
919 {
920         struct device *dev = &client->dev;
921         u32 val;
922         int ret;
923 
924         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
925         if (ret) {
926                 dev_err(&client->dev, "HID register address not provided\n");
927                 return -ENODEV;
928         }
929         if (val >> 16) {
930                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
931                         val);
932                 return -EINVAL;
933         }
934         pdata->hid_descriptor_address = val;
935 
936         return 0;
937 }
938 
939 static const struct of_device_id i2c_hid_of_match[] = {
940         { .compatible = "hid-over-i2c" },
941         {},
942 };
943 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
944 #else
945 static inline int i2c_hid_of_probe(struct i2c_client *client,
946                 struct i2c_hid_platform_data *pdata)
947 {
948         return -ENODEV;
949 }
950 #endif
951 
952 static int i2c_hid_probe(struct i2c_client *client,
953                          const struct i2c_device_id *dev_id)
954 {
955         int ret;
956         struct i2c_hid *ihid;
957         struct hid_device *hid;
958         __u16 hidRegister;
959         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
960 
961         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
962 
963         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
964         if (!ihid)
965                 return -ENOMEM;
966 
967         if (client->dev.of_node) {
968                 ret = i2c_hid_of_probe(client, &ihid->pdata);
969                 if (ret)
970                         goto err;
971         } else if (!platform_data) {
972                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
973                 if (ret) {
974                         dev_err(&client->dev,
975                                 "HID register address not provided\n");
976                         goto err;
977                 }
978         } else {
979                 ihid->pdata = *platform_data;
980         }
981 
982         if (client->irq > 0) {
983                 ihid->irq = client->irq;
984         } else if (ACPI_COMPANION(&client->dev)) {
985                 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
986                 if (IS_ERR(ihid->desc)) {
987                         dev_err(&client->dev, "Failed to get GPIO interrupt\n");
988                         return PTR_ERR(ihid->desc);
989                 }
990 
991                 ihid->irq = gpiod_to_irq(ihid->desc);
992                 if (ihid->irq < 0) {
993                         gpiod_put(ihid->desc);
994                         dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
995                         return ihid->irq;
996                 }
997         }
998 
999         i2c_set_clientdata(client, ihid);
1000 
1001         ihid->client = client;
1002 
1003         hidRegister = ihid->pdata.hid_descriptor_address;
1004         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1005 
1006         init_waitqueue_head(&ihid->wait);
1007         mutex_init(&ihid->reset_lock);
1008 
1009         /* we need to allocate the command buffer without knowing the maximum
1010          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1011          * real computation later. */
1012         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1013         if (ret < 0)
1014                 goto err;
1015 
1016         pm_runtime_get_noresume(&client->dev);
1017         pm_runtime_set_active(&client->dev);
1018         pm_runtime_enable(&client->dev);
1019 
1020         ret = i2c_hid_fetch_hid_descriptor(ihid);
1021         if (ret < 0)
1022                 goto err_pm;
1023 
1024         ret = i2c_hid_init_irq(client);
1025         if (ret < 0)
1026                 goto err_pm;
1027 
1028         hid = hid_allocate_device();
1029         if (IS_ERR(hid)) {
1030                 ret = PTR_ERR(hid);
1031                 goto err_irq;
1032         }
1033 
1034         ihid->hid = hid;
1035 
1036         hid->driver_data = client;
1037         hid->ll_driver = &i2c_hid_ll_driver;
1038         hid->dev.parent = &client->dev;
1039         hid->bus = BUS_I2C;
1040         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1041         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1042         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1043 
1044         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1045                  client->name, hid->vendor, hid->product);
1046         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1047 
1048         ret = hid_add_device(hid);
1049         if (ret) {
1050                 if (ret != -ENODEV)
1051                         hid_err(client, "can't add hid device: %d\n", ret);
1052                 goto err_mem_free;
1053         }
1054 
1055         pm_runtime_put(&client->dev);
1056         return 0;
1057 
1058 err_mem_free:
1059         hid_destroy_device(hid);
1060 
1061 err_irq:
1062         free_irq(ihid->irq, ihid);
1063 
1064 err_pm:
1065         pm_runtime_put_noidle(&client->dev);
1066         pm_runtime_disable(&client->dev);
1067 
1068 err:
1069         if (ihid->desc)
1070                 gpiod_put(ihid->desc);
1071 
1072         i2c_hid_free_buffers(ihid);
1073         kfree(ihid);
1074         return ret;
1075 }
1076 
1077 static int i2c_hid_remove(struct i2c_client *client)
1078 {
1079         struct i2c_hid *ihid = i2c_get_clientdata(client);
1080         struct hid_device *hid;
1081 
1082         pm_runtime_get_sync(&client->dev);
1083         pm_runtime_disable(&client->dev);
1084         pm_runtime_set_suspended(&client->dev);
1085         pm_runtime_put_noidle(&client->dev);
1086 
1087         hid = ihid->hid;
1088         hid_destroy_device(hid);
1089 
1090         free_irq(ihid->irq, ihid);
1091 
1092         if (ihid->bufsize)
1093                 i2c_hid_free_buffers(ihid);
1094 
1095         if (ihid->desc)
1096                 gpiod_put(ihid->desc);
1097 
1098         kfree(ihid);
1099 
1100         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1101 
1102         return 0;
1103 }
1104 
1105 #ifdef CONFIG_PM_SLEEP
1106 static int i2c_hid_suspend(struct device *dev)
1107 {
1108         struct i2c_client *client = to_i2c_client(dev);
1109         struct i2c_hid *ihid = i2c_get_clientdata(client);
1110         struct hid_device *hid = ihid->hid;
1111         int ret = 0;
1112         int wake_status;
1113 
1114         if (hid->driver && hid->driver->suspend)
1115                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1116 
1117         disable_irq(ihid->irq);
1118         if (device_may_wakeup(&client->dev)) {
1119                 wake_status = enable_irq_wake(ihid->irq);
1120                 if (!wake_status)
1121                         ihid->irq_wake_enabled = true;
1122                 else
1123                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1124                                 wake_status);
1125         }
1126 
1127         /* Save some power */
1128         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1129 
1130         return ret;
1131 }
1132 
1133 static int i2c_hid_resume(struct device *dev)
1134 {
1135         int ret;
1136         struct i2c_client *client = to_i2c_client(dev);
1137         struct i2c_hid *ihid = i2c_get_clientdata(client);
1138         struct hid_device *hid = ihid->hid;
1139         int wake_status;
1140 
1141         enable_irq(ihid->irq);
1142         ret = i2c_hid_hwreset(client);
1143         if (ret)
1144                 return ret;
1145 
1146         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1147                 wake_status = disable_irq_wake(ihid->irq);
1148                 if (!wake_status)
1149                         ihid->irq_wake_enabled = false;
1150                 else
1151                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1152                                 wake_status);
1153         }
1154 
1155         if (hid->driver && hid->driver->reset_resume) {
1156                 ret = hid->driver->reset_resume(hid);
1157                 return ret;
1158         }
1159 
1160         return 0;
1161 }
1162 #endif
1163 
1164 #ifdef CONFIG_PM
1165 static int i2c_hid_runtime_suspend(struct device *dev)
1166 {
1167         struct i2c_client *client = to_i2c_client(dev);
1168         struct i2c_hid *ihid = i2c_get_clientdata(client);
1169 
1170         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1171         disable_irq(ihid->irq);
1172         return 0;
1173 }
1174 
1175 static int i2c_hid_runtime_resume(struct device *dev)
1176 {
1177         struct i2c_client *client = to_i2c_client(dev);
1178         struct i2c_hid *ihid = i2c_get_clientdata(client);
1179 
1180         enable_irq(ihid->irq);
1181         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1182         return 0;
1183 }
1184 #endif
1185 
1186 static const struct dev_pm_ops i2c_hid_pm = {
1187         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1188         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1189                            NULL)
1190 };
1191 
1192 static const struct i2c_device_id i2c_hid_id_table[] = {
1193         { "hid", 0 },
1194         { },
1195 };
1196 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1197 
1198 
1199 static struct i2c_driver i2c_hid_driver = {
1200         .driver = {
1201                 .name   = "i2c_hid",
1202                 .pm     = &i2c_hid_pm,
1203                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1204                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1205         },
1206 
1207         .probe          = i2c_hid_probe,
1208         .remove         = i2c_hid_remove,
1209 
1210         .id_table       = i2c_hid_id_table,
1211 };
1212 
1213 module_i2c_driver(i2c_hid_driver);
1214 
1215 MODULE_DESCRIPTION("HID over I2C core driver");
1216 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1217 MODULE_LICENSE("GPL");
1218 

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