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

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 };
155 
156 static int __i2c_hid_command(struct i2c_client *client,
157                 const struct i2c_hid_cmd *command, u8 reportID,
158                 u8 reportType, u8 *args, int args_len,
159                 unsigned char *buf_recv, int data_len)
160 {
161         struct i2c_hid *ihid = i2c_get_clientdata(client);
162         union command *cmd = (union command *)ihid->cmdbuf;
163         int ret;
164         struct i2c_msg msg[2];
165         int msg_num = 1;
166 
167         int length = command->length;
168         bool wait = command->wait;
169         unsigned int registerIndex = command->registerIndex;
170 
171         /* special case for hid_descr_cmd */
172         if (command == &hid_descr_cmd) {
173                 cmd->c.reg = ihid->wHIDDescRegister;
174         } else {
175                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
176                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
177         }
178 
179         if (length > 2) {
180                 cmd->c.opcode = command->opcode;
181                 cmd->c.reportTypeID = reportID | reportType << 4;
182         }
183 
184         memcpy(cmd->data + length, args, args_len);
185         length += args_len;
186 
187         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
188 
189         msg[0].addr = client->addr;
190         msg[0].flags = client->flags & I2C_M_TEN;
191         msg[0].len = length;
192         msg[0].buf = cmd->data;
193         if (data_len > 0) {
194                 msg[1].addr = client->addr;
195                 msg[1].flags = client->flags & I2C_M_TEN;
196                 msg[1].flags |= I2C_M_RD;
197                 msg[1].len = data_len;
198                 msg[1].buf = buf_recv;
199                 msg_num = 2;
200                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
201         }
202 
203         if (wait)
204                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
205 
206         ret = i2c_transfer(client->adapter, msg, msg_num);
207 
208         if (data_len > 0)
209                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
210 
211         if (ret != msg_num)
212                 return ret < 0 ? ret : -EIO;
213 
214         ret = 0;
215 
216         if (wait) {
217                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
218                 if (!wait_event_timeout(ihid->wait,
219                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
220                                 msecs_to_jiffies(5000)))
221                         ret = -ENODATA;
222                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
223         }
224 
225         return ret;
226 }
227 
228 static int i2c_hid_command(struct i2c_client *client,
229                 const struct i2c_hid_cmd *command,
230                 unsigned char *buf_recv, int data_len)
231 {
232         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
233                                 buf_recv, data_len);
234 }
235 
236 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
237                 u8 reportID, unsigned char *buf_recv, int data_len)
238 {
239         struct i2c_hid *ihid = i2c_get_clientdata(client);
240         u8 args[3];
241         int ret;
242         int args_len = 0;
243         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
244 
245         i2c_hid_dbg(ihid, "%s\n", __func__);
246 
247         if (reportID >= 0x0F) {
248                 args[args_len++] = reportID;
249                 reportID = 0x0F;
250         }
251 
252         args[args_len++] = readRegister & 0xFF;
253         args[args_len++] = readRegister >> 8;
254 
255         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
256                 reportType, args, args_len, buf_recv, data_len);
257         if (ret) {
258                 dev_err(&client->dev,
259                         "failed to retrieve report from device.\n");
260                 return ret;
261         }
262 
263         return 0;
264 }
265 
266 /**
267  * i2c_hid_set_or_send_report: forward an incoming report to the device
268  * @client: the i2c_client of the device
269  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
270  * @reportID: the report ID
271  * @buf: the actual data to transfer, without the report ID
272  * @len: size of buf
273  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
274  */
275 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
276                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
277 {
278         struct i2c_hid *ihid = i2c_get_clientdata(client);
279         u8 *args = ihid->argsbuf;
280         const struct i2c_hid_cmd *hidcmd;
281         int ret;
282         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
283         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
284         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
285 
286         /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
287         u16 size =      2                       /* size */ +
288                         (reportID ? 1 : 0)      /* reportID */ +
289                         data_len                /* buf */;
290         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
291                         2                       /* dataRegister */ +
292                         size                    /* args */;
293         int index = 0;
294 
295         i2c_hid_dbg(ihid, "%s\n", __func__);
296 
297         if (!use_data && maxOutputLength == 0)
298                 return -ENOSYS;
299 
300         if (reportID >= 0x0F) {
301                 args[index++] = reportID;
302                 reportID = 0x0F;
303         }
304 
305         /*
306          * use the data register for feature reports or if the device does not
307          * support the output register
308          */
309         if (use_data) {
310                 args[index++] = dataRegister & 0xFF;
311                 args[index++] = dataRegister >> 8;
312                 hidcmd = &hid_set_report_cmd;
313         } else {
314                 args[index++] = outputRegister & 0xFF;
315                 args[index++] = outputRegister >> 8;
316                 hidcmd = &hid_no_cmd;
317         }
318 
319         args[index++] = size & 0xFF;
320         args[index++] = size >> 8;
321 
322         if (reportID)
323                 args[index++] = reportID;
324 
325         memcpy(&args[index], buf, data_len);
326 
327         ret = __i2c_hid_command(client, hidcmd, reportID,
328                 reportType, args, args_len, NULL, 0);
329         if (ret) {
330                 dev_err(&client->dev, "failed to set a report to device.\n");
331                 return ret;
332         }
333 
334         return data_len;
335 }
336 
337 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
338 {
339         struct i2c_hid *ihid = i2c_get_clientdata(client);
340         int ret;
341 
342         i2c_hid_dbg(ihid, "%s\n", __func__);
343 
344         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
345                 0, NULL, 0, NULL, 0);
346         if (ret)
347                 dev_err(&client->dev, "failed to change power setting.\n");
348 
349         return ret;
350 }
351 
352 static int i2c_hid_hwreset(struct i2c_client *client)
353 {
354         struct i2c_hid *ihid = i2c_get_clientdata(client);
355         int ret;
356 
357         i2c_hid_dbg(ihid, "%s\n", __func__);
358 
359         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
360         if (ret)
361                 return ret;
362 
363         i2c_hid_dbg(ihid, "resetting...\n");
364 
365         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
366         if (ret) {
367                 dev_err(&client->dev, "failed to reset device.\n");
368                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
369                 return ret;
370         }
371 
372         return 0;
373 }
374 
375 static void i2c_hid_get_input(struct i2c_hid *ihid)
376 {
377         int ret, ret_size;
378         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
379 
380         if (size > ihid->bufsize)
381                 size = ihid->bufsize;
382 
383         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
384         if (ret != size) {
385                 if (ret < 0)
386                         return;
387 
388                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
389                         __func__, ret, size);
390                 return;
391         }
392 
393         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
394 
395         if (!ret_size) {
396                 /* host or device initiated RESET completed */
397                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
398                         wake_up(&ihid->wait);
399                 return;
400         }
401 
402         if (ret_size > size) {
403                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
404                         __func__, size, ret_size);
405                 return;
406         }
407 
408         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
409 
410         if (test_bit(I2C_HID_STARTED, &ihid->flags))
411                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
412                                 ret_size - 2, 1);
413 
414         return;
415 }
416 
417 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
418 {
419         struct i2c_hid *ihid = dev_id;
420 
421         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
422                 return IRQ_HANDLED;
423 
424         i2c_hid_get_input(ihid);
425 
426         return IRQ_HANDLED;
427 }
428 
429 static int i2c_hid_get_report_length(struct hid_report *report)
430 {
431         return ((report->size - 1) >> 3) + 1 +
432                 report->device->report_enum[report->type].numbered + 2;
433 }
434 
435 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
436         size_t bufsize)
437 {
438         struct hid_device *hid = report->device;
439         struct i2c_client *client = hid->driver_data;
440         struct i2c_hid *ihid = i2c_get_clientdata(client);
441         unsigned int size, ret_size;
442 
443         size = i2c_hid_get_report_length(report);
444         if (i2c_hid_get_report(client,
445                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
446                         report->id, buffer, size))
447                 return;
448 
449         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
450 
451         ret_size = buffer[0] | (buffer[1] << 8);
452 
453         if (ret_size != size) {
454                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
455                         __func__, size, ret_size);
456                 return;
457         }
458 
459         /* hid->driver_lock is held as we are in probe function,
460          * we just need to setup the input fields, so using
461          * hid_report_raw_event is safe. */
462         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
463 }
464 
465 /*
466  * Initialize all reports
467  */
468 static void i2c_hid_init_reports(struct hid_device *hid)
469 {
470         struct hid_report *report;
471         struct i2c_client *client = hid->driver_data;
472         struct i2c_hid *ihid = i2c_get_clientdata(client);
473         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
474 
475         if (!inbuf) {
476                 dev_err(&client->dev, "can not retrieve initial reports\n");
477                 return;
478         }
479 
480         /*
481          * The device must be powered on while we fetch initial reports
482          * from it.
483          */
484         pm_runtime_get_sync(&client->dev);
485 
486         list_for_each_entry(report,
487                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
488                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
489 
490         pm_runtime_put(&client->dev);
491 
492         kfree(inbuf);
493 }
494 
495 /*
496  * Traverse the supplied list of reports and find the longest
497  */
498 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
499                 unsigned int *max)
500 {
501         struct hid_report *report;
502         unsigned int size;
503 
504         /* We should not rely on wMaxInputLength, as some devices may set it to
505          * a wrong length. */
506         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
507                 size = i2c_hid_get_report_length(report);
508                 if (*max < size)
509                         *max = size;
510         }
511 }
512 
513 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
514 {
515         kfree(ihid->inbuf);
516         kfree(ihid->rawbuf);
517         kfree(ihid->argsbuf);
518         kfree(ihid->cmdbuf);
519         ihid->inbuf = NULL;
520         ihid->rawbuf = NULL;
521         ihid->cmdbuf = NULL;
522         ihid->argsbuf = NULL;
523         ihid->bufsize = 0;
524 }
525 
526 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
527 {
528         /* the worst case is computed from the set_report command with a
529          * reportID > 15 and the maximum report length */
530         int args_len = sizeof(__u8) + /* optional ReportID byte */
531                        sizeof(__u16) + /* data register */
532                        sizeof(__u16) + /* size of the report */
533                        report_size; /* report */
534 
535         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
536         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
537         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
538         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
539 
540         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
541                 i2c_hid_free_buffers(ihid);
542                 return -ENOMEM;
543         }
544 
545         ihid->bufsize = report_size;
546 
547         return 0;
548 }
549 
550 static int i2c_hid_get_raw_report(struct hid_device *hid,
551                 unsigned char report_number, __u8 *buf, size_t count,
552                 unsigned char report_type)
553 {
554         struct i2c_client *client = hid->driver_data;
555         struct i2c_hid *ihid = i2c_get_clientdata(client);
556         size_t ret_count, ask_count;
557         int ret;
558 
559         if (report_type == HID_OUTPUT_REPORT)
560                 return -EINVAL;
561 
562         /* +2 bytes to include the size of the reply in the query buffer */
563         ask_count = min(count + 2, (size_t)ihid->bufsize);
564 
565         ret = i2c_hid_get_report(client,
566                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
567                         report_number, ihid->rawbuf, ask_count);
568 
569         if (ret < 0)
570                 return ret;
571 
572         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
573 
574         if (ret_count <= 2)
575                 return 0;
576 
577         ret_count = min(ret_count, ask_count);
578 
579         /* The query buffer contains the size, dropping it in the reply */
580         count = min(count, ret_count - 2);
581         memcpy(buf, ihid->rawbuf + 2, count);
582 
583         return count;
584 }
585 
586 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
587                 size_t count, unsigned char report_type, bool use_data)
588 {
589         struct i2c_client *client = hid->driver_data;
590         int report_id = buf[0];
591         int ret;
592 
593         if (report_type == HID_INPUT_REPORT)
594                 return -EINVAL;
595 
596         if (report_id) {
597                 buf++;
598                 count--;
599         }
600 
601         ret = i2c_hid_set_or_send_report(client,
602                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
603                                 report_id, buf, count, use_data);
604 
605         if (report_id && ret >= 0)
606                 ret++; /* add report_id to the number of transfered bytes */
607 
608         return ret;
609 }
610 
611 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
612                 size_t count)
613 {
614         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
615                         false);
616 }
617 
618 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
619                                __u8 *buf, size_t len, unsigned char rtype,
620                                int reqtype)
621 {
622         switch (reqtype) {
623         case HID_REQ_GET_REPORT:
624                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
625         case HID_REQ_SET_REPORT:
626                 if (buf[0] != reportnum)
627                         return -EINVAL;
628                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
629         default:
630                 return -EIO;
631         }
632 }
633 
634 static int i2c_hid_parse(struct hid_device *hid)
635 {
636         struct i2c_client *client = hid->driver_data;
637         struct i2c_hid *ihid = i2c_get_clientdata(client);
638         struct i2c_hid_desc *hdesc = &ihid->hdesc;
639         unsigned int rsize;
640         char *rdesc;
641         int ret;
642         int tries = 3;
643 
644         i2c_hid_dbg(ihid, "entering %s\n", __func__);
645 
646         rsize = le16_to_cpu(hdesc->wReportDescLength);
647         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
648                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
649                 return -EINVAL;
650         }
651 
652         do {
653                 ret = i2c_hid_hwreset(client);
654                 if (ret)
655                         msleep(1000);
656         } while (tries-- > 0 && ret);
657 
658         if (ret)
659                 return ret;
660 
661         rdesc = kzalloc(rsize, GFP_KERNEL);
662 
663         if (!rdesc) {
664                 dbg_hid("couldn't allocate rdesc memory\n");
665                 return -ENOMEM;
666         }
667 
668         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
669 
670         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
671         if (ret) {
672                 hid_err(hid, "reading report descriptor failed\n");
673                 kfree(rdesc);
674                 return -EIO;
675         }
676 
677         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
678 
679         ret = hid_parse_report(hid, rdesc, rsize);
680         kfree(rdesc);
681         if (ret) {
682                 dbg_hid("parsing report descriptor failed\n");
683                 return ret;
684         }
685 
686         return 0;
687 }
688 
689 static int i2c_hid_start(struct hid_device *hid)
690 {
691         struct i2c_client *client = hid->driver_data;
692         struct i2c_hid *ihid = i2c_get_clientdata(client);
693         int ret;
694         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
695 
696         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
697         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
698         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
699 
700         if (bufsize > ihid->bufsize) {
701                 i2c_hid_free_buffers(ihid);
702 
703                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
704 
705                 if (ret)
706                         return ret;
707         }
708 
709         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
710                 i2c_hid_init_reports(hid);
711 
712         return 0;
713 }
714 
715 static void i2c_hid_stop(struct hid_device *hid)
716 {
717         hid->claimed = 0;
718 }
719 
720 static int i2c_hid_open(struct hid_device *hid)
721 {
722         struct i2c_client *client = hid->driver_data;
723         struct i2c_hid *ihid = i2c_get_clientdata(client);
724         int ret = 0;
725 
726         mutex_lock(&i2c_hid_open_mut);
727         if (!hid->open++) {
728                 ret = pm_runtime_get_sync(&client->dev);
729                 if (ret < 0) {
730                         hid->open--;
731                         goto done;
732                 }
733                 set_bit(I2C_HID_STARTED, &ihid->flags);
734         }
735 done:
736         mutex_unlock(&i2c_hid_open_mut);
737         return ret < 0 ? ret : 0;
738 }
739 
740 static void i2c_hid_close(struct hid_device *hid)
741 {
742         struct i2c_client *client = hid->driver_data;
743         struct i2c_hid *ihid = i2c_get_clientdata(client);
744 
745         /* protecting hid->open to make sure we don't restart
746          * data acquistion due to a resumption we no longer
747          * care about
748          */
749         mutex_lock(&i2c_hid_open_mut);
750         if (!--hid->open) {
751                 clear_bit(I2C_HID_STARTED, &ihid->flags);
752 
753                 /* Save some power */
754                 pm_runtime_put(&client->dev);
755         }
756         mutex_unlock(&i2c_hid_open_mut);
757 }
758 
759 static int i2c_hid_power(struct hid_device *hid, int lvl)
760 {
761         struct i2c_client *client = hid->driver_data;
762         struct i2c_hid *ihid = i2c_get_clientdata(client);
763 
764         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
765 
766         switch (lvl) {
767         case PM_HINT_FULLON:
768                 pm_runtime_get_sync(&client->dev);
769                 break;
770         case PM_HINT_NORMAL:
771                 pm_runtime_put(&client->dev);
772                 break;
773         }
774         return 0;
775 }
776 
777 static struct hid_ll_driver i2c_hid_ll_driver = {
778         .parse = i2c_hid_parse,
779         .start = i2c_hid_start,
780         .stop = i2c_hid_stop,
781         .open = i2c_hid_open,
782         .close = i2c_hid_close,
783         .power = i2c_hid_power,
784         .output_report = i2c_hid_output_report,
785         .raw_request = i2c_hid_raw_request,
786 };
787 
788 static int i2c_hid_init_irq(struct i2c_client *client)
789 {
790         struct i2c_hid *ihid = i2c_get_clientdata(client);
791         int ret;
792 
793         dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
794 
795         ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
796                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
797                         client->name, ihid);
798         if (ret < 0) {
799                 dev_warn(&client->dev,
800                         "Could not register for %s interrupt, irq = %d,"
801                         " ret = %d\n",
802                         client->name, ihid->irq, ret);
803 
804                 return ret;
805         }
806 
807         return 0;
808 }
809 
810 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
811 {
812         struct i2c_client *client = ihid->client;
813         struct i2c_hid_desc *hdesc = &ihid->hdesc;
814         unsigned int dsize;
815         int ret;
816 
817         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
818         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
819         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
820                                 sizeof(struct i2c_hid_desc));
821         if (ret) {
822                 dev_err(&client->dev, "hid_descr_cmd failed\n");
823                 return -ENODEV;
824         }
825 
826         /* Validate the length of HID descriptor, the 4 first bytes:
827          * bytes 0-1 -> length
828          * bytes 2-3 -> bcdVersion (has to be 1.00) */
829         /* check bcdVersion == 1.0 */
830         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
831                 dev_err(&client->dev,
832                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
833                         le16_to_cpu(hdesc->bcdVersion));
834                 return -ENODEV;
835         }
836 
837         /* Descriptor length should be 30 bytes as per the specification */
838         dsize = le16_to_cpu(hdesc->wHIDDescLength);
839         if (dsize != sizeof(struct i2c_hid_desc)) {
840                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
841                         dsize);
842                 return -ENODEV;
843         }
844         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
845         return 0;
846 }
847 
848 #ifdef CONFIG_ACPI
849 
850 /* Default GPIO mapping */
851 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
852 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
853         { "gpios", &i2c_hid_irq_gpio, 1 },
854         { },
855 };
856 
857 static int i2c_hid_acpi_pdata(struct i2c_client *client,
858                 struct i2c_hid_platform_data *pdata)
859 {
860         static u8 i2c_hid_guid[] = {
861                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
862                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
863         };
864         union acpi_object *obj;
865         struct acpi_device *adev;
866         acpi_handle handle;
867         int ret;
868 
869         handle = ACPI_HANDLE(&client->dev);
870         if (!handle || acpi_bus_get_device(handle, &adev))
871                 return -ENODEV;
872 
873         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
874                                       ACPI_TYPE_INTEGER);
875         if (!obj) {
876                 dev_err(&client->dev, "device _DSM execution failed\n");
877                 return -ENODEV;
878         }
879 
880         pdata->hid_descriptor_address = obj->integer.value;
881         ACPI_FREE(obj);
882 
883         /* GPIOs are optional */
884         ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
885         return ret < 0 && ret != -ENXIO ? ret : 0;
886 }
887 
888 static const struct acpi_device_id i2c_hid_acpi_match[] = {
889         {"ACPI0C50", 0 },
890         {"PNP0C50", 0 },
891         { },
892 };
893 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
894 #else
895 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
896                 struct i2c_hid_platform_data *pdata)
897 {
898         return -ENODEV;
899 }
900 #endif
901 
902 #ifdef CONFIG_OF
903 static int i2c_hid_of_probe(struct i2c_client *client,
904                 struct i2c_hid_platform_data *pdata)
905 {
906         struct device *dev = &client->dev;
907         u32 val;
908         int ret;
909 
910         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
911         if (ret) {
912                 dev_err(&client->dev, "HID register address not provided\n");
913                 return -ENODEV;
914         }
915         if (val >> 16) {
916                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
917                         val);
918                 return -EINVAL;
919         }
920         pdata->hid_descriptor_address = val;
921 
922         return 0;
923 }
924 
925 static const struct of_device_id i2c_hid_of_match[] = {
926         { .compatible = "hid-over-i2c" },
927         {},
928 };
929 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
930 #else
931 static inline int i2c_hid_of_probe(struct i2c_client *client,
932                 struct i2c_hid_platform_data *pdata)
933 {
934         return -ENODEV;
935 }
936 #endif
937 
938 static int i2c_hid_probe(struct i2c_client *client,
939                          const struct i2c_device_id *dev_id)
940 {
941         int ret;
942         struct i2c_hid *ihid;
943         struct hid_device *hid;
944         __u16 hidRegister;
945         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
946 
947         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
948 
949         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
950         if (!ihid)
951                 return -ENOMEM;
952 
953         if (client->dev.of_node) {
954                 ret = i2c_hid_of_probe(client, &ihid->pdata);
955                 if (ret)
956                         goto err;
957         } else if (!platform_data) {
958                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
959                 if (ret) {
960                         dev_err(&client->dev,
961                                 "HID register address not provided\n");
962                         goto err;
963                 }
964         } else {
965                 ihid->pdata = *platform_data;
966         }
967 
968         if (client->irq > 0) {
969                 ihid->irq = client->irq;
970         } else if (ACPI_COMPANION(&client->dev)) {
971                 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
972                 if (IS_ERR(ihid->desc)) {
973                         dev_err(&client->dev, "Failed to get GPIO interrupt\n");
974                         return PTR_ERR(ihid->desc);
975                 }
976 
977                 ihid->irq = gpiod_to_irq(ihid->desc);
978                 if (ihid->irq < 0) {
979                         gpiod_put(ihid->desc);
980                         dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
981                         return ihid->irq;
982                 }
983         }
984 
985         i2c_set_clientdata(client, ihid);
986 
987         ihid->client = client;
988 
989         hidRegister = ihid->pdata.hid_descriptor_address;
990         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
991 
992         init_waitqueue_head(&ihid->wait);
993 
994         /* we need to allocate the command buffer without knowing the maximum
995          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
996          * real computation later. */
997         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
998         if (ret < 0)
999                 goto err;
1000 
1001         pm_runtime_get_noresume(&client->dev);
1002         pm_runtime_set_active(&client->dev);
1003         pm_runtime_enable(&client->dev);
1004 
1005         ret = i2c_hid_fetch_hid_descriptor(ihid);
1006         if (ret < 0)
1007                 goto err_pm;
1008 
1009         ret = i2c_hid_init_irq(client);
1010         if (ret < 0)
1011                 goto err_pm;
1012 
1013         hid = hid_allocate_device();
1014         if (IS_ERR(hid)) {
1015                 ret = PTR_ERR(hid);
1016                 goto err_irq;
1017         }
1018 
1019         ihid->hid = hid;
1020 
1021         hid->driver_data = client;
1022         hid->ll_driver = &i2c_hid_ll_driver;
1023         hid->dev.parent = &client->dev;
1024         hid->bus = BUS_I2C;
1025         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1026         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1027         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1028 
1029         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1030                  client->name, hid->vendor, hid->product);
1031         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1032 
1033         ret = hid_add_device(hid);
1034         if (ret) {
1035                 if (ret != -ENODEV)
1036                         hid_err(client, "can't add hid device: %d\n", ret);
1037                 goto err_mem_free;
1038         }
1039 
1040         pm_runtime_put(&client->dev);
1041         return 0;
1042 
1043 err_mem_free:
1044         hid_destroy_device(hid);
1045 
1046 err_irq:
1047         free_irq(ihid->irq, ihid);
1048 
1049 err_pm:
1050         pm_runtime_put_noidle(&client->dev);
1051         pm_runtime_disable(&client->dev);
1052 
1053 err:
1054         if (ihid->desc)
1055                 gpiod_put(ihid->desc);
1056 
1057         i2c_hid_free_buffers(ihid);
1058         kfree(ihid);
1059         return ret;
1060 }
1061 
1062 static int i2c_hid_remove(struct i2c_client *client)
1063 {
1064         struct i2c_hid *ihid = i2c_get_clientdata(client);
1065         struct hid_device *hid;
1066 
1067         pm_runtime_get_sync(&client->dev);
1068         pm_runtime_disable(&client->dev);
1069         pm_runtime_set_suspended(&client->dev);
1070         pm_runtime_put_noidle(&client->dev);
1071 
1072         hid = ihid->hid;
1073         hid_destroy_device(hid);
1074 
1075         free_irq(ihid->irq, ihid);
1076 
1077         if (ihid->bufsize)
1078                 i2c_hid_free_buffers(ihid);
1079 
1080         if (ihid->desc)
1081                 gpiod_put(ihid->desc);
1082 
1083         kfree(ihid);
1084 
1085         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1086 
1087         return 0;
1088 }
1089 
1090 #ifdef CONFIG_PM_SLEEP
1091 static int i2c_hid_suspend(struct device *dev)
1092 {
1093         struct i2c_client *client = to_i2c_client(dev);
1094         struct i2c_hid *ihid = i2c_get_clientdata(client);
1095         struct hid_device *hid = ihid->hid;
1096         int ret = 0;
1097         int wake_status;
1098 
1099         if (hid->driver && hid->driver->suspend)
1100                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1101 
1102         disable_irq(ihid->irq);
1103         if (device_may_wakeup(&client->dev)) {
1104                 wake_status = enable_irq_wake(ihid->irq);
1105                 if (!wake_status)
1106                         ihid->irq_wake_enabled = true;
1107                 else
1108                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1109                                 wake_status);
1110         }
1111 
1112         /* Save some power */
1113         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1114 
1115         return ret;
1116 }
1117 
1118 static int i2c_hid_resume(struct device *dev)
1119 {
1120         int ret;
1121         struct i2c_client *client = to_i2c_client(dev);
1122         struct i2c_hid *ihid = i2c_get_clientdata(client);
1123         struct hid_device *hid = ihid->hid;
1124         int wake_status;
1125 
1126         enable_irq(ihid->irq);
1127         ret = i2c_hid_hwreset(client);
1128         if (ret)
1129                 return ret;
1130 
1131         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1132                 wake_status = disable_irq_wake(ihid->irq);
1133                 if (!wake_status)
1134                         ihid->irq_wake_enabled = false;
1135                 else
1136                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1137                                 wake_status);
1138         }
1139 
1140         if (hid->driver && hid->driver->reset_resume) {
1141                 ret = hid->driver->reset_resume(hid);
1142                 return ret;
1143         }
1144 
1145         return 0;
1146 }
1147 #endif
1148 
1149 #ifdef CONFIG_PM
1150 static int i2c_hid_runtime_suspend(struct device *dev)
1151 {
1152         struct i2c_client *client = to_i2c_client(dev);
1153         struct i2c_hid *ihid = i2c_get_clientdata(client);
1154 
1155         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1156         disable_irq(ihid->irq);
1157         return 0;
1158 }
1159 
1160 static int i2c_hid_runtime_resume(struct device *dev)
1161 {
1162         struct i2c_client *client = to_i2c_client(dev);
1163         struct i2c_hid *ihid = i2c_get_clientdata(client);
1164 
1165         enable_irq(ihid->irq);
1166         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1167         return 0;
1168 }
1169 #endif
1170 
1171 static const struct dev_pm_ops i2c_hid_pm = {
1172         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1173         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1174                            NULL)
1175 };
1176 
1177 static const struct i2c_device_id i2c_hid_id_table[] = {
1178         { "hid", 0 },
1179         { },
1180 };
1181 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1182 
1183 
1184 static struct i2c_driver i2c_hid_driver = {
1185         .driver = {
1186                 .name   = "i2c_hid",
1187                 .owner  = THIS_MODULE,
1188                 .pm     = &i2c_hid_pm,
1189                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1190                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1191         },
1192 
1193         .probe          = i2c_hid_probe,
1194         .remove         = i2c_hid_remove,
1195 
1196         .id_table       = i2c_hid_id_table,
1197 };
1198 
1199 module_i2c_driver(i2c_hid_driver);
1200 
1201 MODULE_DESCRIPTION("HID over I2C core driver");
1202 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1203 MODULE_LICENSE("GPL");
1204 

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