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