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