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