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/device.h>
  29 #include <linux/wait.h>
  30 #include <linux/err.h>
  31 #include <linux/string.h>
  32 #include <linux/list.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/kernel.h>
  35 #include <linux/hid.h>
  36 #include <linux/mutex.h>
  37 #include <linux/acpi.h>
  38
  39 #include <linux/i2c/i2c-hid.h>
  40
  41 /* flags */
  42 #define I2C_HID_STARTED         (1 << 0)
  43 #define I2C_HID_RESET_PENDING   (1 << 1)
  44 #define I2C_HID_READ_PENDING    (1 << 2)
  45
  46 #define I2C_HID_PWR_ON          0x00
  47 #define I2C_HID_PWR_SLEEP       0x01
  48
  49 /* debug option */
  50 static bool debug;
  51 module_param(debug, bool, 0444);
  52 MODULE_PARM_DESC(debug, "print a lot of debug information");
  53
  54 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  55 do {                                                                      \
  56         if (debug)                                                        \
  57                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  58 } while (0)
  59
  60 struct i2c_hid_desc {
  61         __le16 wHIDDescLength;
  62         __le16 bcdVersion;
  63         __le16 wReportDescLength;
  64         __le16 wReportDescRegister;
  65         __le16 wInputRegister;
  66         __le16 wMaxInputLength;
  67         __le16 wOutputRegister;
  68         __le16 wMaxOutputLength;
  69         __le16 wCommandRegister;
  70         __le16 wDataRegister;
  71         __le16 wVendorID;
  72         __le16 wProductID;
  73         __le16 wVersionID;
  74         __le32 reserved;
  75 } __packed;
  76
  77 struct i2c_hid_cmd {
  78         unsigned int registerIndex;
  79         __u8 opcode;
  80         unsigned int length;
  81         bool wait;
  82 };
  83
  84 union command {
  85         u8 data[0];
  86         struct cmd {
  87                 __le16 reg;
  88                 __u8 reportTypeID;
  89                 __u8 opcode;
  90         } __packed c;
  91 };
  92
  93 #define I2C_HID_CMD(opcode_) \
  94         .opcode = opcode_, .length = 4, \
  95         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
  96
  97 /* fetch HID descriptor */
  98 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
  99 /* fetch report descriptors */
 100 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 101                 .registerIndex = offsetof(struct i2c_hid_desc,
 102                         wReportDescRegister),
 103                 .opcode = 0x00,
 104                 .length = 2 };
 105 /* commands */
 106 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 107                                                           .wait = true };
 108 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 109 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 110 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 111
 112 /*
 113  * These definitions are not used here, but are defined by the spec.
 114  * Keeping them here for documentation purposes.
 115  *
 116  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 117  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 118  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 119  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 120  */
 121
 122 static DEFINE_MUTEX(i2c_hid_open_mut);
 123
 124 /* The main device structure */
 125 struct i2c_hid {
 126         struct i2c_client       *client;        /* i2c client */
 127         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 128         union {
 129                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 130                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 131         };
 132         __le16                  wHIDDescRegister; /* location of the i2c
 133                                                    * register of the HID
 134                                                    * descriptor. */
 135         unsigned int            bufsize;        /* i2c buffer size */
 136         char                    *inbuf;         /* Input buffer */
 137         char                    *cmdbuf;        /* Command buffer */
 138         char                    *argsbuf;       /* Command arguments buffer */
 139
 140         unsigned long           flags;          /* device flags */
 141
 142         wait_queue_head_t       wait;           /* For waiting the interrupt */
 143
 144         struct i2c_hid_platform_data pdata;
 145 };
 146
 147 static int __i2c_hid_command(struct i2c_client *client,
 148                 const struct i2c_hid_cmd *command, u8 reportID,
 149                 u8 reportType, u8 *args, int args_len,
 150                 unsigned char *buf_recv, int data_len)
 151 {
 152         struct i2c_hid *ihid = i2c_get_clientdata(client);
 153         union command *cmd = (union command *)ihid->cmdbuf;
 154         int ret;
 155         struct i2c_msg msg[2];
 156         int msg_num = 1;
 157
 158         int length = command->length;
 159         bool wait = command->wait;
 160         unsigned int registerIndex = command->registerIndex;
 161
 162         /* special case for hid_descr_cmd */
 163         if (command == &hid_descr_cmd) {
 164                 cmd->c.reg = ihid->wHIDDescRegister;
 165         } else {
 166                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 167                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 168         }
 169
 170         if (length > 2) {
 171                 cmd->c.opcode = command->opcode;
 172                 cmd->c.reportTypeID = reportID | reportType << 4;
 173         }
 174
 175         memcpy(cmd->data + length, args, args_len);
 176         length += args_len;
 177
 178         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 179
 180         msg[0].addr = client->addr;
 181         msg[0].flags = client->flags & I2C_M_TEN;
 182         msg[0].len = length;
 183         msg[0].buf = cmd->data;
 184         if (data_len > 0) {
 185                 msg[1].addr = client->addr;
 186                 msg[1].flags = client->flags & I2C_M_TEN;
 187                 msg[1].flags |= I2C_M_RD;
 188                 msg[1].len = data_len;
 189                 msg[1].buf = buf_recv;
 190                 msg_num = 2;
 191                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 192         }
 193
 194         if (wait)
 195                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 196
 197         ret = i2c_transfer(client->adapter, msg, msg_num);
 198
 199         if (data_len > 0)
 200                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 201
 202         if (ret != msg_num)
 203                 return ret < 0 ? ret : -EIO;
 204
 205         ret = 0;
 206
 207         if (wait) {
 208                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 209                 if (!wait_event_timeout(ihid->wait,
 210                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 211                                 msecs_to_jiffies(5000)))
 212                         ret = -ENODATA;
 213                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 214         }
 215
 216         return ret;
 217 }
 218
 219 static int i2c_hid_command(struct i2c_client *client,
 220                 const struct i2c_hid_cmd *command,
 221                 unsigned char *buf_recv, int data_len)
 222 {
 223         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 224                                 buf_recv, data_len);
 225 }
 226
 227 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 228                 u8 reportID, unsigned char *buf_recv, int data_len)
 229 {
 230         struct i2c_hid *ihid = i2c_get_clientdata(client);
 231         u8 args[3];
 232         int ret;
 233         int args_len = 0;
 234         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 235
 236         i2c_hid_dbg(ihid, "%s\n", __func__);
 237
 238         if (reportID >= 0x0F) {
 239                 args[args_len++] = reportID;
 240                 reportID = 0x0F;
 241         }
 242
 243         args[args_len++] = readRegister & 0xFF;
 244         args[args_len++] = readRegister >> 8;
 245
 246         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 247                 reportType, args, args_len, buf_recv, data_len);
 248         if (ret) {
 249                 dev_err(&client->dev,
 250                         "failed to retrieve report from device.\n");
 251                 return ret;
 252         }
 253
 254         return 0;
 255 }
 256
 257 static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
 258                 u8 reportID, unsigned char *buf, size_t data_len)
 259 {
 260         struct i2c_hid *ihid = i2c_get_clientdata(client);
 261         u8 *args = ihid->argsbuf;
 262         int ret;
 263         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 264
 265         /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
 266         u16 size =      2                       /* size */ +
 267                         (reportID ? 1 : 0)      /* reportID */ +
 268                         data_len                /* buf */;
 269         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 270                         2                       /* dataRegister */ +
 271                         size                    /* args */;
 272         int index = 0;
 273
 274         i2c_hid_dbg(ihid, "%s\n", __func__);
 275
 276         if (reportID >= 0x0F) {
 277                 args[index++] = reportID;
 278                 reportID = 0x0F;
 279         }
 280
 281         args[index++] = dataRegister & 0xFF;
 282         args[index++] = dataRegister >> 8;
 283
 284         args[index++] = size & 0xFF;
 285         args[index++] = size >> 8;
 286
 287         if (reportID)
 288                 args[index++] = reportID;
 289
 290         memcpy(&args[index], buf, data_len);
 291
 292         ret = __i2c_hid_command(client, &hid_set_report_cmd, reportID,
 293                 reportType, args, args_len, NULL, 0);
 294         if (ret) {
 295                 dev_err(&client->dev, "failed to set a report to device.\n");
 296                 return ret;
 297         }
 298
 299         return data_len;
 300 }
 301
 302 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 303 {
 304         struct i2c_hid *ihid = i2c_get_clientdata(client);
 305         int ret;
 306
 307         i2c_hid_dbg(ihid, "%s\n", __func__);
 308
 309         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 310                 0, NULL, 0, NULL, 0);
 311         if (ret)
 312                 dev_err(&client->dev, "failed to change power setting.\n");
 313
 314         return ret;
 315 }
 316
 317 static int i2c_hid_hwreset(struct i2c_client *client)
 318 {
 319         struct i2c_hid *ihid = i2c_get_clientdata(client);
 320         int ret;
 321
 322         i2c_hid_dbg(ihid, "%s\n", __func__);
 323
 324         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 325         if (ret)
 326                 return ret;
 327
 328         i2c_hid_dbg(ihid, "resetting...\n");
 329
 330         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 331         if (ret) {
 332                 dev_err(&client->dev, "failed to reset device.\n");
 333                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 334                 return ret;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static void i2c_hid_get_input(struct i2c_hid *ihid)
 341 {
 342         int ret, ret_size;
 343         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 344
 345         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 346         if (ret != size) {
 347                 if (ret < 0)
 348                         return;
 349
 350                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 351                         __func__, ret, size);
 352                 return;
 353         }
 354
 355         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 356
 357         if (!ret_size) {
 358                 /* host or device initiated RESET completed */
 359                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 360                         wake_up(&ihid->wait);
 361                 return;
 362         }
 363
 364         if (ret_size > size) {
 365                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 366                         __func__, size, ret_size);
 367                 return;
 368         }
 369
 370         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 371
 372         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 373                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 374                                 ret_size - 2, 1);
 375
 376         return;
 377 }
 378
 379 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 380 {
 381         struct i2c_hid *ihid = dev_id;
 382
 383         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 384                 return IRQ_HANDLED;
 385
 386         i2c_hid_get_input(ihid);
 387
 388         return IRQ_HANDLED;
 389 }
 390
 391 static int i2c_hid_get_report_length(struct hid_report *report)
 392 {
 393         return ((report->size - 1) >> 3) + 1 +
 394                 report->device->report_enum[report->type].numbered + 2;
 395 }
 396
 397 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 398         size_t bufsize)
 399 {
 400         struct hid_device *hid = report->device;
 401         struct i2c_client *client = hid->driver_data;
 402         struct i2c_hid *ihid = i2c_get_clientdata(client);
 403         unsigned int size, ret_size;
 404
 405         size = i2c_hid_get_report_length(report);
 406         if (i2c_hid_get_report(client,
 407                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 408                         report->id, buffer, size))
 409                 return;
 410
 411         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
 412
 413         ret_size = buffer[0] | (buffer[1] << 8);
 414
 415         if (ret_size != size) {
 416                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 417                         __func__, size, ret_size);
 418                 return;
 419         }
 420
 421         /* hid->driver_lock is held as we are in probe function,
 422          * we just need to setup the input fields, so using
 423          * hid_report_raw_event is safe. */
 424         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 425 }
 426
 427 /*
 428  * Initialize all reports
 429  */
 430 static void i2c_hid_init_reports(struct hid_device *hid)
 431 {
 432         struct hid_report *report;
 433         struct i2c_client *client = hid->driver_data;
 434         struct i2c_hid *ihid = i2c_get_clientdata(client);
 435         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 436
 437         if (!inbuf) {
 438                 dev_err(&client->dev, "can not retrieve initial reports\n");
 439                 return;
 440         }
 441
 442         list_for_each_entry(report,
 443                 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
 444                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 445
 446         list_for_each_entry(report,
 447                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 448                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 449
 450         kfree(inbuf);
 451 }
 452
 453 /*
 454  * Traverse the supplied list of reports and find the longest
 455  */
 456 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 457                 unsigned int *max)
 458 {
 459         struct hid_report *report;
 460         unsigned int size;
 461
 462         /* We should not rely on wMaxInputLength, as some devices may set it to
 463          * a wrong length. */
 464         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 465                 size = i2c_hid_get_report_length(report);
 466                 if (*max < size)
 467                         *max = size;
 468         }
 469 }
 470
 471 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 472 {
 473         kfree(ihid->inbuf);
 474         kfree(ihid->argsbuf);
 475         kfree(ihid->cmdbuf);
 476         ihid->inbuf = NULL;
 477         ihid->cmdbuf = NULL;
 478         ihid->argsbuf = NULL;
 479         ihid->bufsize = 0;
 480 }
 481
 482 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 483 {
 484         /* the worst case is computed from the set_report command with a
 485          * reportID > 15 and the maximum report length */
 486         int args_len = sizeof(__u8) + /* optional ReportID byte */
 487                        sizeof(__u16) + /* data register */
 488                        sizeof(__u16) + /* size of the report */
 489                        report_size; /* report */
 490
 491         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 492         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 493         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 494
 495         if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 496                 i2c_hid_free_buffers(ihid);
 497                 return -ENOMEM;
 498         }
 499
 500         ihid->bufsize = report_size;
 501
 502         return 0;
 503 }
 504
 505 static int i2c_hid_get_raw_report(struct hid_device *hid,
 506                 unsigned char report_number, __u8 *buf, size_t count,
 507                 unsigned char report_type)
 508 {
 509         struct i2c_client *client = hid->driver_data;
 510         struct i2c_hid *ihid = i2c_get_clientdata(client);
 511         size_t ret_count, ask_count;
 512         int ret;
 513
 514         if (report_type == HID_OUTPUT_REPORT)
 515                 return -EINVAL;
 516
 517         /* +2 bytes to include the size of the reply in the query buffer */
 518         ask_count = min(count + 2, (size_t)ihid->bufsize);
 519
 520         ret = i2c_hid_get_report(client,
 521                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 522                         report_number, ihid->inbuf, ask_count);
 523
 524         if (ret < 0)
 525                 return ret;
 526
 527         ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
 528
 529         if (ret_count <= 2)
 530                 return 0;
 531
 532         ret_count = min(ret_count, ask_count);
 533
 534         /* The query buffer contains the size, dropping it in the reply */
 535         count = min(count, ret_count - 2);
 536         memcpy(buf, ihid->inbuf + 2, count);
 537
 538         return count;
 539 }
 540
 541 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 542                 size_t count, unsigned char report_type)
 543 {
 544         struct i2c_client *client = hid->driver_data;
 545         int report_id = buf[0];
 546         int ret;
 547
 548         if (report_type == HID_INPUT_REPORT)
 549                 return -EINVAL;
 550
 551         if (report_id) {
 552                 buf++;
 553                 count--;
 554         }
 555
 556         ret = i2c_hid_set_report(client,
 557                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 558                                 report_id, buf, count);
 559
 560         if (report_id && ret >= 0)
 561                 ret++; /* add report_id to the number of transfered bytes */
 562
 563         return ret;
 564 }
 565
 566 static void i2c_hid_request(struct hid_device *hid, struct hid_report *rep,
 567                 int reqtype)
 568 {
 569         struct i2c_client *client = hid->driver_data;
 570         char *buf;
 571         int ret;
 572         int len = i2c_hid_get_report_length(rep) - 2;
 573
 574         buf = kzalloc(len, GFP_KERNEL);
 575         if (!buf)
 576                 return;
 577
 578         switch (reqtype) {
 579         case HID_REQ_GET_REPORT:
 580                 ret = i2c_hid_get_raw_report(hid, rep->id, buf, len, rep->type);
 581                 if (ret < 0)
 582                         dev_err(&client->dev, "%s: unable to get report: %d\n",
 583                                 __func__, ret);
 584                 else
 585                         hid_input_report(hid, rep->type, buf, ret, 0);
 586                 break;
 587         case HID_REQ_SET_REPORT:
 588                 hid_output_report(rep, buf);
 589                 i2c_hid_output_raw_report(hid, buf, len, rep->type);
 590                 break;
 591         }
 592
 593         kfree(buf);
 594 }
 595
 596 static int i2c_hid_parse(struct hid_device *hid)
 597 {
 598         struct i2c_client *client = hid->driver_data;
 599         struct i2c_hid *ihid = i2c_get_clientdata(client);
 600         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 601         unsigned int rsize;
 602         char *rdesc;
 603         int ret;
 604         int tries = 3;
 605
 606         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 607
 608         rsize = le16_to_cpu(hdesc->wReportDescLength);
 609         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 610                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 611                 return -EINVAL;
 612         }
 613
 614         do {
 615                 ret = i2c_hid_hwreset(client);
 616                 if (ret)
 617                         msleep(1000);
 618         } while (tries-- > 0 && ret);
 619
 620         if (ret)
 621                 return ret;
 622
 623         rdesc = kzalloc(rsize, GFP_KERNEL);
 624
 625         if (!rdesc) {
 626                 dbg_hid("couldn't allocate rdesc memory\n");
 627                 return -ENOMEM;
 628         }
 629
 630         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 631
 632         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 633         if (ret) {
 634                 hid_err(hid, "reading report descriptor failed\n");
 635                 kfree(rdesc);
 636                 return -EIO;
 637         }
 638
 639         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 640
 641         ret = hid_parse_report(hid, rdesc, rsize);
 642         kfree(rdesc);
 643         if (ret) {
 644                 dbg_hid("parsing report descriptor failed\n");
 645                 return ret;
 646         }
 647
 648         return 0;
 649 }
 650
 651 static int i2c_hid_start(struct hid_device *hid)
 652 {
 653         struct i2c_client *client = hid->driver_data;
 654         struct i2c_hid *ihid = i2c_get_clientdata(client);
 655         int ret;
 656         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 657
 658         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 659         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 660         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 661
 662         if (bufsize > ihid->bufsize) {
 663                 i2c_hid_free_buffers(ihid);
 664
 665                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 666
 667                 if (ret)
 668                         return ret;
 669         }
 670
 671         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 672                 i2c_hid_init_reports(hid);
 673
 674         return 0;
 675 }
 676
 677 static void i2c_hid_stop(struct hid_device *hid)
 678 {
 679         struct i2c_client *client = hid->driver_data;
 680         struct i2c_hid *ihid = i2c_get_clientdata(client);
 681
 682         hid->claimed = 0;
 683
 684         i2c_hid_free_buffers(ihid);
 685 }
 686
 687 static int i2c_hid_open(struct hid_device *hid)
 688 {
 689         struct i2c_client *client = hid->driver_data;
 690         struct i2c_hid *ihid = i2c_get_clientdata(client);
 691         int ret = 0;
 692
 693         mutex_lock(&i2c_hid_open_mut);
 694         if (!hid->open++) {
 695                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 696                 if (ret) {
 697                         hid->open--;
 698                         goto done;
 699                 }
 700                 set_bit(I2C_HID_STARTED, &ihid->flags);
 701         }
 702 done:
 703         mutex_unlock(&i2c_hid_open_mut);
 704         return ret;
 705 }
 706
 707 static void i2c_hid_close(struct hid_device *hid)
 708 {
 709         struct i2c_client *client = hid->driver_data;
 710         struct i2c_hid *ihid = i2c_get_clientdata(client);
 711
 712         /* protecting hid->open to make sure we don't restart
 713          * data acquistion due to a resumption we no longer
 714          * care about
 715          */
 716         mutex_lock(&i2c_hid_open_mut);
 717         if (!--hid->open) {
 718                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 719
 720                 /* Save some power */
 721                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 722         }
 723         mutex_unlock(&i2c_hid_open_mut);
 724 }
 725
 726 static int i2c_hid_power(struct hid_device *hid, int lvl)
 727 {
 728         struct i2c_client *client = hid->driver_data;
 729         struct i2c_hid *ihid = i2c_get_clientdata(client);
 730         int ret = 0;
 731
 732         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 733
 734         switch (lvl) {
 735         case PM_HINT_FULLON:
 736                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 737                 break;
 738         case PM_HINT_NORMAL:
 739                 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 740                 break;
 741         }
 742         return ret;
 743 }
 744
 745 static int i2c_hid_hidinput_input_event(struct input_dev *dev,
 746                 unsigned int type, unsigned int code, int value)
 747 {
 748         struct hid_device *hid = input_get_drvdata(dev);
 749         struct hid_field *field;
 750         int offset;
 751
 752         if (type == EV_FF)
 753                 return input_ff_event(dev, type, code, value);
 754
 755         if (type != EV_LED)
 756                 return -1;
 757
 758         offset = hidinput_find_field(hid, type, code, &field);
 759
 760         if (offset == -1) {
 761                 hid_warn(dev, "event field not found\n");
 762                 return -1;
 763         }
 764
 765         return hid_set_field(field, offset, value);
 766 }
 767
 768 static struct hid_ll_driver i2c_hid_ll_driver = {
 769         .parse = i2c_hid_parse,
 770         .start = i2c_hid_start,
 771         .stop = i2c_hid_stop,
 772         .open = i2c_hid_open,
 773         .close = i2c_hid_close,
 774         .power = i2c_hid_power,
 775         .request = i2c_hid_request,
 776         .hidinput_input_event = i2c_hid_hidinput_input_event,
 777 };
 778
 779 static int i2c_hid_init_irq(struct i2c_client *client)
 780 {
 781         struct i2c_hid *ihid = i2c_get_clientdata(client);
 782         int ret;
 783
 784         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 785
 786         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 787                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 788                         client->name, ihid);
 789         if (ret < 0) {
 790                 dev_warn(&client->dev,
 791                         "Could not register for %s interrupt, irq = %d,"
 792                         " ret = %d\n",
 793                         client->name, client->irq, ret);
 794
 795                 return ret;
 796         }
 797
 798         return 0;
 799 }
 800
 801 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 802 {
 803         struct i2c_client *client = ihid->client;
 804         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 805         unsigned int dsize;
 806         int ret;
 807
 808         /* Fetch the length of HID description, retrieve the 4 first bytes:
 809          * bytes 0-1 -> length
 810          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 811         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
 812
 813         i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %*ph\n",
 814                         __func__, 4, ihid->hdesc_buffer);
 815
 816         if (ret) {
 817                 dev_err(&client->dev,
 818                         "unable to fetch the size of HID descriptor (ret=%d)\n",
 819                         ret);
 820                 return -ENODEV;
 821         }
 822
 823         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 824         /*
 825          * the size of the HID descriptor should at least contain
 826          * its size and the bcdVersion (4 bytes), and should not be greater
 827          * than sizeof(struct i2c_hid_desc) as we directly fill this struct
 828          * through i2c_hid_command.
 829          */
 830         if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
 831                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 832                         dsize);
 833                 return -ENODEV;
 834         }
 835
 836         /* check bcdVersion == 1.0 */
 837         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 838                 dev_err(&client->dev,
 839                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 840                         le16_to_cpu(hdesc->bcdVersion));
 841                 return -ENODEV;
 842         }
 843
 844         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 845
 846         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 847                                 dsize);
 848         if (ret) {
 849                 dev_err(&client->dev, "hid_descr_cmd Fail\n");
 850                 return -ENODEV;
 851         }
 852
 853         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 854
 855         return 0;
 856 }
 857
 858 #ifdef CONFIG_ACPI
 859 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 860                 struct i2c_hid_platform_data *pdata)
 861 {
 862         static u8 i2c_hid_guid[] = {
 863                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 864                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 865         };
 866         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
 867         union acpi_object params[4], *obj;
 868         struct acpi_object_list input;
 869         struct acpi_device *adev;
 870         acpi_handle handle;
 871
 872         handle = ACPI_HANDLE(&client->dev);
 873         if (!handle || acpi_bus_get_device(handle, &adev))
 874                 return -ENODEV;
 875
 876         input.count = ARRAY_SIZE(params);
 877         input.pointer = params;
 878
 879         params[0].type = ACPI_TYPE_BUFFER;
 880         params[0].buffer.length = sizeof(i2c_hid_guid);
 881         params[0].buffer.pointer = i2c_hid_guid;
 882         params[1].type = ACPI_TYPE_INTEGER;
 883         params[1].integer.value = 1;
 884         params[2].type = ACPI_TYPE_INTEGER;
 885         params[2].integer.value = 1; /* HID function */
 886         params[3].type = ACPI_TYPE_INTEGER;
 887         params[3].integer.value = 0;
 888
 889         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
 890                 dev_err(&client->dev, "device _DSM execution failed\n");
 891                 return -ENODEV;
 892         }
 893
 894         obj = (union acpi_object *)buf.pointer;
 895         if (obj->type != ACPI_TYPE_INTEGER) {
 896                 dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
 897                         obj->type);
 898                 kfree(buf.pointer);
 899                 return -EINVAL;
 900         }
 901
 902         pdata->hid_descriptor_address = obj->integer.value;
 903
 904         kfree(buf.pointer);
 905         return 0;
 906 }
 907
 908 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 909         {"ACPI0C50", 0 },
 910         {"PNP0C50", 0 },
 911         { },
 912 };
 913 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 914 #else
 915 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 916                 struct i2c_hid_platform_data *pdata)
 917 {
 918         return -ENODEV;
 919 }
 920 #endif
 921
 922 static int i2c_hid_probe(struct i2c_client *client,
 923                          const struct i2c_device_id *dev_id)
 924 {
 925         int ret;
 926         struct i2c_hid *ihid;
 927         struct hid_device *hid;
 928         __u16 hidRegister;
 929         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 930
 931         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 932
 933         if (!client->irq) {
 934                 dev_err(&client->dev,
 935                         "HID over i2c has not been provided an Int IRQ\n");
 936                 return -EINVAL;
 937         }
 938
 939         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 940         if (!ihid)
 941                 return -ENOMEM;
 942
 943         if (!platform_data) {
 944                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 945                 if (ret) {
 946                         dev_err(&client->dev,
 947                                 "HID register address not provided\n");
 948                         goto err;
 949                 }
 950         } else {
 951                 ihid->pdata = *platform_data;
 952         }
 953
 954         i2c_set_clientdata(client, ihid);
 955
 956         ihid->client = client;
 957
 958         hidRegister = ihid->pdata.hid_descriptor_address;
 959         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
 960
 961         init_waitqueue_head(&ihid->wait);
 962
 963         /* we need to allocate the command buffer without knowing the maximum
 964          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 965          * real computation later. */
 966         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 967         if (ret < 0)
 968                 goto err;
 969
 970         ret = i2c_hid_fetch_hid_descriptor(ihid);
 971         if (ret < 0)
 972                 goto err;
 973
 974         ret = i2c_hid_init_irq(client);
 975         if (ret < 0)
 976                 goto err;
 977
 978         hid = hid_allocate_device();
 979         if (IS_ERR(hid)) {
 980                 ret = PTR_ERR(hid);
 981                 goto err_irq;
 982         }
 983
 984         ihid->hid = hid;
 985
 986         hid->driver_data = client;
 987         hid->ll_driver = &i2c_hid_ll_driver;
 988         hid->hid_get_raw_report = i2c_hid_get_raw_report;
 989         hid->hid_output_raw_report = i2c_hid_output_raw_report;
 990         hid->dev.parent = &client->dev;
 991         ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
 992         hid->bus = BUS_I2C;
 993         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 994         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 995         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
 996
 997         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
 998                  client->name, hid->vendor, hid->product);
 999
1000         ret = hid_add_device(hid);
1001         if (ret) {
1002                 if (ret != -ENODEV)
1003                         hid_err(client, "can't add hid device: %d\n", ret);
1004                 goto err_mem_free;
1005         }
1006
1007         return 0;
1008
1009 err_mem_free:
1010         hid_destroy_device(hid);
1011
1012 err_irq:
1013         free_irq(client->irq, ihid);
1014
1015 err:
1016         i2c_hid_free_buffers(ihid);
1017         kfree(ihid);
1018         return ret;
1019 }
1020
1021 static int i2c_hid_remove(struct i2c_client *client)
1022 {
1023         struct i2c_hid *ihid = i2c_get_clientdata(client);
1024         struct hid_device *hid;
1025
1026         hid = ihid->hid;
1027         hid_destroy_device(hid);
1028
1029         free_irq(client->irq, ihid);
1030
1031         if (ihid->bufsize)
1032                 i2c_hid_free_buffers(ihid);
1033
1034         kfree(ihid);
1035
1036         return 0;
1037 }
1038
1039 #ifdef CONFIG_PM_SLEEP
1040 static int i2c_hid_suspend(struct device *dev)
1041 {
1042         struct i2c_client *client = to_i2c_client(dev);
1043
1044         if (device_may_wakeup(&client->dev))
1045                 enable_irq_wake(client->irq);
1046
1047         /* Save some power */
1048         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1049
1050         return 0;
1051 }
1052
1053 static int i2c_hid_resume(struct device *dev)
1054 {
1055         int ret;
1056         struct i2c_client *client = to_i2c_client(dev);
1057
1058         ret = i2c_hid_hwreset(client);
1059         if (ret)
1060                 return ret;
1061
1062         if (device_may_wakeup(&client->dev))
1063                 disable_irq_wake(client->irq);
1064
1065         return 0;
1066 }
1067 #endif
1068
1069 static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
1070
1071 static const struct i2c_device_id i2c_hid_id_table[] = {
1072         { "hid", 0 },
1073         { },
1074 };
1075 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1076
1077
1078 static struct i2c_driver i2c_hid_driver = {
1079         .driver = {
1080                 .name   = "i2c_hid",
1081                 .owner  = THIS_MODULE,
1082                 .pm     = &i2c_hid_pm,
1083                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1084         },
1085
1086         .probe          = i2c_hid_probe,
1087         .remove         = i2c_hid_remove,
1088
1089         .id_table       = i2c_hid_id_table,
1090 };
1091
1092 module_i2c_driver(i2c_hid_driver);
1093
1094 MODULE_DESCRIPTION("HID over I2C core driver");
1095 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1096 MODULE_LICENSE("GPL");