drivers/hid/i2c-hid/i2c-hid.c

   1 /*
   2  * HID over I2C protocol implementation
   3  *
   4  * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
   5  * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
   6  * Copyright (c) 2012 Red Hat, Inc
   7  *
   8  * This code is partly based on "USB HID support for Linux":
   9  *
  10  *  Copyright (c) 1999 Andreas Gal
  11  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
  12  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
  13  *  Copyright (c) 2007-2008 Oliver Neukum
  14  *  Copyright (c) 2006-2010 Jiri Kosina
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file COPYING in the main directory of this archive for
  18  * more details.
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/i2c.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/input.h>
  25 #include <linux/delay.h>
  26 #include <linux/slab.h>
  27 #include <linux/pm.h>
  28 #include <linux/device.h>
  29 #include <linux/wait.h>
  30 #include <linux/err.h>
  31 #include <linux/string.h>
  32 #include <linux/list.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/kernel.h>
  35 #include <linux/hid.h>
  36 #include <linux/mutex.h>
  37 #include <linux/acpi.h>
  38
  39 #include <linux/i2c/i2c-hid.h>
  40
  41 /* flags */
  42 #define I2C_HID_STARTED         (1 << 0)
  43 #define I2C_HID_RESET_PENDING   (1 << 1)
  44 #define I2C_HID_READ_PENDING    (1 << 2)
  45
  46 #define I2C_HID_PWR_ON          0x00
  47 #define I2C_HID_PWR_SLEEP       0x01
  48
  49 /* debug option */
  50 static bool debug;
  51 module_param(debug, bool, 0444);
  52 MODULE_PARM_DESC(debug, "print a lot of debug information");
  53
  54 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  55 do {                                                                      \
  56         if (debug)                                                        \
  57                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  58 } while (0)
  59
  60 struct i2c_hid_desc {
  61         __le16 wHIDDescLength;
  62         __le16 bcdVersion;
  63         __le16 wReportDescLength;
  64         __le16 wReportDescRegister;
  65         __le16 wInputRegister;
  66         __le16 wMaxInputLength;
  67         __le16 wOutputRegister;
  68         __le16 wMaxOutputLength;
  69         __le16 wCommandRegister;
  70         __le16 wDataRegister;
  71         __le16 wVendorID;
  72         __le16 wProductID;
  73         __le16 wVersionID;
  74         __le32 reserved;
  75 } __packed;
  76
  77 struct i2c_hid_cmd {
  78         unsigned int registerIndex;
  79         __u8 opcode;
  80         unsigned int length;
  81         bool wait;
  82 };
  83
  84 union command {
  85         u8 data[0];
  86         struct cmd {
  87                 __le16 reg;
  88                 __u8 reportTypeID;
  89                 __u8 opcode;
  90         } __packed c;
  91 };
  92
  93 #define I2C_HID_CMD(opcode_) \
  94         .opcode = opcode_, .length = 4, \
  95         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
  96
  97 /* fetch HID descriptor */
  98 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
  99 /* fetch report descriptors */
 100 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 101                 .registerIndex = offsetof(struct i2c_hid_desc,
 102                         wReportDescRegister),
 103                 .opcode = 0x00,
 104                 .length = 2 };
 105 /* commands */
 106 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 107                                                           .wait = true };
 108 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 109 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 110 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 111
 112 /*
 113  * These definitions are not used here, but are defined by the spec.
 114  * Keeping them here for documentation purposes.
 115  *
 116  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 117  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 118  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 119  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 120  */
 121
 122 static DEFINE_MUTEX(i2c_hid_open_mut);
 123
 124 /* The main device structure */
 125 struct i2c_hid {
 126         struct i2c_client       *client;        /* i2c client */
 127         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 128         union {
 129                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 130                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 131         };
 132         __le16                  wHIDDescRegister; /* location of the i2c
 133                                                    * register of the HID
 134                                                    * descriptor. */
 135         unsigned int            bufsize;        /* i2c buffer size */
 136         char                    *inbuf;         /* Input buffer */
 137         char                    *cmdbuf;        /* Command buffer */
 138         char                    *argsbuf;       /* Command arguments buffer */
 139
 140         unsigned long           flags;          /* device flags */
 141
 142         wait_queue_head_t       wait;           /* For waiting the interrupt */
 143
 144         struct i2c_hid_platform_data pdata;
 145 };
 146
 147 static int __i2c_hid_command(struct i2c_client *client,
 148                 const struct i2c_hid_cmd *command, u8 reportID,
 149                 u8 reportType, u8 *args, int args_len,
 150                 unsigned char *buf_recv, int data_len)
 151 {
 152         struct i2c_hid *ihid = i2c_get_clientdata(client);
 153         union command *cmd = (union command *)ihid->cmdbuf;
 154         int ret;
 155         struct i2c_msg msg[2];
 156         int msg_num = 1;
 157
 158         int length = command->length;
 159         bool wait = command->wait;
 160         unsigned int registerIndex = command->registerIndex;
 161
 162         /* special case for hid_descr_cmd */
 163         if (command == &hid_descr_cmd) {
 164                 cmd->c.reg = ihid->wHIDDescRegister;
 165         } else {
 166                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 167                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 168         }
 169
 170         if (length > 2) {
 171                 cmd->c.opcode = command->opcode;
 172                 cmd->c.reportTypeID = reportID | reportType << 4;
 173         }
 174
 175         memcpy(cmd->data + length, args, args_len);
 176         length += args_len;
 177
 178         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 179
 180         msg[0].addr = client->addr;
 181         msg[0].flags = client->flags & I2C_M_TEN;
 182         msg[0].len = length;
 183         msg[0].buf = cmd->data;
 184         if (data_len > 0) {
 185                 msg[1].addr = client->addr;
 186                 msg[1].flags = client->flags & I2C_M_TEN;
 187                 msg[1].flags |= I2C_M_RD;
 188                 msg[1].len = data_len;
 189                 msg[1].buf = buf_recv;
 190                 msg_num = 2;
 191                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 192         }
 193
 194         if (wait)
 195                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 196
 197         ret = i2c_transfer(client->adapter, msg, msg_num);
 198
 199         if (data_len > 0)
 200                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 201
 202         if (ret != msg_num)
 203                 return ret < 0 ? ret : -EIO;
 204
 205         ret = 0;
 206
 207         if (wait) {
 208                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 209                 if (!wait_event_timeout(ihid->wait,
 210                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 211                                 msecs_to_jiffies(5000)))
 212                         ret = -ENODATA;
 213                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 214         }
 215
 216         return ret;
 217 }
 218
 219 static int i2c_hid_command(struct i2c_client *client,
 220                 const struct i2c_hid_cmd *command,
 221                 unsigned char *buf_recv, int data_len)
 222 {
 223         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 224                                 buf_recv, data_len);
 225 }
 226
 227 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 228                 u8 reportID, unsigned char *buf_recv, int data_len)
 229 {
 230         struct i2c_hid *ihid = i2c_get_clientdata(client);
 231         u8 args[3];
 232         int ret;
 233         int args_len = 0;
 234         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 235
 236         i2c_hid_dbg(ihid, "%s\n", __func__);
 237
 238         if (reportID >= 0x0F) {
 239                 args[args_len++] = reportID;
 240                 reportID = 0x0F;
 241         }
 242
 243         args[args_len++] = readRegister & 0xFF;
 244         args[args_len++] = readRegister >> 8;
 245
 246         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 247                 reportType, args, args_len, buf_recv, data_len);
 248         if (ret) {
 249                 dev_err(&client->dev,
 250                         "failed to retrieve report from device.\n");
 251                 return ret;
 252         }
 253
 254         return 0;
 255 }
 256
 257 static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
 258                 u8 reportID, unsigned char *buf, size_t data_len)
 259 {
 260         struct i2c_hid *ihid = i2c_get_clientdata(client);
 261         u8 *args = ihid->argsbuf;
 262         int ret;
 263         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 264
 265         /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
 266         u16 size =      2                       /* size */ +
 267                         (reportID ? 1 : 0)      /* reportID */ +
 268                         data_len                /* buf */;
 269         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 270                         2                       /* dataRegister */ +
 271                         size                    /* args */;
 272         int index = 0;
 273
 274         i2c_hid_dbg(ihid, "%s\n", __func__);
 275
 276         if (reportID >= 0x0F) {
 277                 args[index++] = reportID;
 278                 reportID = 0x0F;
 279         }
 280
 281         args[index++] = dataRegister & 0xFF;
 282         args[index++] = dataRegister >> 8;
 283
 284         args[index++] = size & 0xFF;
 285         args[index++] = size >> 8;
 286
 287         if (reportID)
 288                 args[index++] = reportID;
 289
 290         memcpy(&args[index], buf, data_len);
 291
 292         ret = __i2c_hid_command(client, &hid_set_report_cmd, reportID,
 293                 reportType, args, args_len, NULL, 0);
 294         if (ret) {
 295                 dev_err(&client->dev, "failed to set a report to device.\n");
 296                 return ret;
 297         }
 298
 299         return data_len;
 300 }
 301
 302 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 303 {
 304         struct i2c_hid *ihid = i2c_get_clientdata(client);
 305         int ret;
 306
 307         i2c_hid_dbg(ihid, "%s\n", __func__);
 308
 309         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 310                 0, NULL, 0, NULL, 0);
 311         if (ret)
 312                 dev_err(&client->dev, "failed to change power setting.\n");
 313
 314         return ret;
 315 }
 316
 317 static int i2c_hid_hwreset(struct i2c_client *client)
 318 {
 319         struct i2c_hid *ihid = i2c_get_clientdata(client);
 320         int ret;
 321
 322         i2c_hid_dbg(ihid, "%s\n", __func__);
 323
 324         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 325         if (ret)
 326                 return ret;
 327
 328         i2c_hid_dbg(ihid, "resetting...\n");
 329
 330         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 331         if (ret) {
 332                 dev_err(&client->dev, "failed to reset device.\n");
 333                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 334                 return ret;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static void i2c_hid_get_input(struct i2c_hid *ihid)
 341 {
 342         int ret, ret_size;
 343         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 344
 345         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 346         if (ret != size) {
 347                 if (ret < 0)
 348                         return;
 349
 350                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 351                         __func__, ret, size);
 352                 return;
 353         }
 354
 355         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 356
 357         if (!ret_size) {
 358                 /* host or device initiated RESET completed */
 359                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 360                         wake_up(&ihid->wait);
 361                 return;
 362         }
 363
 364         if (ret_size > size) {
 365                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 366                         __func__, size, ret_size);
 367                 return;
 368         }
 369
 370         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 371
 372         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 373                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 374                                 ret_size - 2, 1);
 375
 376         return;
 377 }
 378
 379 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 380 {
 381         struct i2c_hid *ihid = dev_id;
 382
 383         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 384                 return IRQ_HANDLED;
 385
 386         i2c_hid_get_input(ihid);
 387
 388         return IRQ_HANDLED;
 389 }
 390
 391 static int i2c_hid_get_report_length(struct hid_report *report)
 392 {
 393         return ((report->size - 1) >> 3) + 1 +
 394                 report->device->report_enum[report->type].numbered + 2;
 395 }
 396
 397 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 398         size_t bufsize)
 399 {
 400         struct hid_device *hid = report->device;
 401         struct i2c_client *client = hid->driver_data;
 402         struct i2c_hid *ihid = i2c_get_clientdata(client);
 403         unsigned int size, ret_size;
 404
 405         size = i2c_hid_get_report_length(report);
 406         if (i2c_hid_get_report(client,
 407                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 408                         report->id, buffer, size))
 409                 return;
 410
 411         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
 412
 413         ret_size = buffer[0] | (buffer[1] << 8);
 414
 415         if (ret_size != size) {
 416                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 417                         __func__, size, ret_size);
 418                 return;
 419         }
 420
 421         /* hid->driver_lock is held as we are in probe function,
 422          * we just need to setup the input fields, so using
 423          * hid_report_raw_event is safe. */
 424         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 425 }
 426
 427 /*
 428  * Initialize all reports
 429  */
 430 static void i2c_hid_init_reports(struct hid_device *hid)
 431 {
 432         struct hid_report *report;
 433         struct i2c_client *client = hid->driver_data;
 434         struct i2c_hid *ihid = i2c_get_clientdata(client);
 435         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 436
 437         if (!inbuf) {
 438                 dev_err(&client->dev, "can not retrieve initial reports\n");
 439                 return;
 440         }
 441
 442         list_for_each_entry(report,
 443                 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
 444                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 445
 446         list_for_each_entry(report,
 447                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 448                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 449
 450         kfree(inbuf);
 451 }
 452
 453 /*
 454  * Traverse the supplied list of reports and find the longest
 455  */
 456 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 457                 unsigned int *max)
 458 {
 459         struct hid_report *report;
 460         unsigned int size;
 461
 462         /* We should not rely on wMaxInputLength, as some devices may set it to
 463          * a wrong length. */
 464         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 465                 size = i2c_hid_get_report_length(report);
 466                 if (*max < size)
 467                         *max = size;
 468         }
 469 }
 470
 471 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 472 {
 473         kfree(ihid->inbuf);
 474         kfree(ihid->argsbuf);
 475         kfree(ihid->cmdbuf);
 476         ihid->inbuf = NULL;
 477         ihid->cmdbuf = NULL;
 478         ihid->argsbuf = NULL;
 479         ihid->bufsize = 0;
 480 }
 481
 482 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 483 {
 484         /* the worst case is computed from the set_report command with a
 485          * reportID > 15 and the maximum report length */
 486         int args_len = sizeof(__u8) + /* optional ReportID byte */
 487                        sizeof(__u16) + /* data register */
 488                        sizeof(__u16) + /* size of the report */
 489                        report_size; /* report */
 490
 491         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 492         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 493         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 494
 495         if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 496                 i2c_hid_free_buffers(ihid);
 497                 return -ENOMEM;
 498         }
 499
 500         ihid->bufsize = report_size;
 501
 502         return 0;
 503 }
 504
 505 static int i2c_hid_get_raw_report(struct hid_device *hid,
 506                 unsigned char report_number, __u8 *buf, size_t count,
 507                 unsigned char report_type)
 508 {
 509         struct i2c_client *client = hid->driver_data;
 510         struct i2c_hid *ihid = i2c_get_clientdata(client);
 511         size_t ret_count, ask_count;
 512         int ret;
 513
 514         if (report_type == HID_OUTPUT_REPORT)
 515                 return -EINVAL;
 516
 517         /* +2 bytes to include the size of the reply in the query buffer */
 518         ask_count = min(count + 2, (size_t)ihid->bufsize);
 519
 520         ret = i2c_hid_get_report(client,
 521                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 522                         report_number, ihid->inbuf, ask_count);
 523
 524         if (ret < 0)
 525                 return ret;
 526
 527         ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
 528
 529         if (ret_count <= 2)
 530                 return 0;
 531
 532         ret_count = min(ret_count, ask_count);
 533
 534         /* The query buffer contains the size, dropping it in the reply */
 535         count = min(count, ret_count - 2);
 536         memcpy(buf, ihid->inbuf + 2, count);
 537
 538         return count;
 539 }
 540
 541 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 542                 size_t count, unsigned char report_type)
 543 {
 544         struct i2c_client *client = hid->driver_data;
 545         int report_id = buf[0];
 546         int ret;
 547
 548         if (report_type == HID_INPUT_REPORT)
 549                 return -EINVAL;
 550
 551         if (report_id) {
 552                 buf++;
 553                 count--;
 554         }
 555
 556         ret = i2c_hid_set_report(client,
 557                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 558                                 report_id, buf, count);
 559
 560         if (report_id && ret >= 0)
 561                 ret++; /* add report_id to the number of transfered bytes */
 562
 563         return ret;
 564 }
 565
 566 static int i2c_hid_parse(struct hid_device *hid)
 567 {
 568         struct i2c_client *client = hid->driver_data;
 569         struct i2c_hid *ihid = i2c_get_clientdata(client);
 570         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 571         unsigned int rsize;
 572         char *rdesc;
 573         int ret;
 574         int tries = 3;
 575
 576         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 577
 578         rsize = le16_to_cpu(hdesc->wReportDescLength);
 579         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 580                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 581                 return -EINVAL;
 582         }
 583
 584         do {
 585                 ret = i2c_hid_hwreset(client);
 586                 if (ret)
 587                         msleep(1000);
 588         } while (tries-- > 0 && ret);
 589
 590         if (ret)
 591                 return ret;
 592
 593         rdesc = kzalloc(rsize, GFP_KERNEL);
 594
 595         if (!rdesc) {
 596                 dbg_hid("couldn't allocate rdesc memory\n");
 597                 return -ENOMEM;
 598         }
 599
 600         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 601
 602         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 603         if (ret) {
 604                 hid_err(hid, "reading report descriptor failed\n");
 605                 kfree(rdesc);
 606                 return -EIO;
 607         }
 608
 609         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 610
 611         ret = hid_parse_report(hid, rdesc, rsize);
 612         kfree(rdesc);
 613         if (ret) {
 614                 dbg_hid("parsing report descriptor failed\n");
 615                 return ret;
 616         }
 617
 618         return 0;
 619 }
 620
 621 static int i2c_hid_start(struct hid_device *hid)
 622 {
 623         struct i2c_client *client = hid->driver_data;
 624         struct i2c_hid *ihid = i2c_get_clientdata(client);
 625         int ret;
 626         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 627
 628         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 629         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 630         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 631
 632         if (bufsize > ihid->bufsize) {
 633                 i2c_hid_free_buffers(ihid);
 634
 635                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 636
 637                 if (ret)
 638                         return ret;
 639         }
 640
 641         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 642                 i2c_hid_init_reports(hid);
 643
 644         return 0;
 645 }
 646
 647 static void i2c_hid_stop(struct hid_device *hid)
 648 {
 649         struct i2c_client *client = hid->driver_data;
 650         struct i2c_hid *ihid = i2c_get_clientdata(client);
 651
 652         hid->claimed = 0;
 653
 654         i2c_hid_free_buffers(ihid);
 655 }
 656
 657 static int i2c_hid_open(struct hid_device *hid)
 658 {
 659         struct i2c_client *client = hid->driver_data;
 660         struct i2c_hid *ihid = i2c_get_clientdata(client);
 661         int ret = 0;
 662
 663         mutex_lock(&i2c_hid_open_mut);
 664         if (!hid->open++) {
 665                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 666                 if (ret) {
 667                         hid->open--;
 668                         goto done;
 669                 }
 670                 set_bit(I2C_HID_STARTED, &ihid->flags);
 671         }
 672 done:
 673         mutex_unlock(&i2c_hid_open_mut);
 674         return ret;
 675 }
 676
 677 static void i2c_hid_close(struct hid_device *hid)
 678 {
 679         struct i2c_client *client = hid->driver_data;
 680         struct i2c_hid *ihid = i2c_get_clientdata(client);
 681
 682         /* protecting hid->open to make sure we don't restart
 683          * data acquistion due to a resumption we no longer
 684          * care about
 685          */
 686         mutex_lock(&i2c_hid_open_mut);
 687         if (!--hid->open) {
 688                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 689
 690                 /* Save some power */
 691                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 692         }
 693         mutex_unlock(&i2c_hid_open_mut);
 694 }
 695
 696 static int i2c_hid_power(struct hid_device *hid, int lvl)
 697 {
 698         struct i2c_client *client = hid->driver_data;
 699         struct i2c_hid *ihid = i2c_get_clientdata(client);
 700         int ret = 0;
 701
 702         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 703
 704         switch (lvl) {
 705         case PM_HINT_FULLON:
 706                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 707                 break;
 708         case PM_HINT_NORMAL:
 709                 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 710                 break;
 711         }
 712         return ret;
 713 }
 714
 715 static int i2c_hid_hidinput_input_event(struct input_dev *dev,
 716                 unsigned int type, unsigned int code, int value)
 717 {
 718         struct hid_device *hid = input_get_drvdata(dev);
 719         struct hid_field *field;
 720         int offset;
 721
 722         if (type == EV_FF)
 723                 return input_ff_event(dev, type, code, value);
 724
 725         if (type != EV_LED)
 726                 return -1;
 727
 728         offset = hidinput_find_field(hid, type, code, &field);
 729
 730         if (offset == -1) {
 731                 hid_warn(dev, "event field not found\n");
 732                 return -1;
 733         }
 734
 735         return hid_set_field(field, offset, value);
 736 }
 737
 738 static struct hid_ll_driver i2c_hid_ll_driver = {
 739         .parse = i2c_hid_parse,
 740         .start = i2c_hid_start,
 741         .stop = i2c_hid_stop,
 742         .open = i2c_hid_open,
 743         .close = i2c_hid_close,
 744         .power = i2c_hid_power,
 745         .hidinput_input_event = i2c_hid_hidinput_input_event,
 746 };
 747
 748 static int i2c_hid_init_irq(struct i2c_client *client)
 749 {
 750         struct i2c_hid *ihid = i2c_get_clientdata(client);
 751         int ret;
 752
 753         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 754
 755         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 756                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 757                         client->name, ihid);
 758         if (ret < 0) {
 759                 dev_warn(&client->dev,
 760                         "Could not register for %s interrupt, irq = %d,"
 761                         " ret = %d\n",
 762                         client->name, client->irq, ret);
 763
 764                 return ret;
 765         }
 766
 767         return 0;
 768 }
 769
 770 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 771 {
 772         struct i2c_client *client = ihid->client;
 773         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 774         unsigned int dsize;
 775         int ret;
 776
 777         /* Fetch the length of HID description, retrieve the 4 first bytes:
 778          * bytes 0-1 -> length
 779          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 780         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
 781
 782         i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %*ph\n",
 783                         __func__, 4, ihid->hdesc_buffer);
 784
 785         if (ret) {
 786                 dev_err(&client->dev,
 787                         "unable to fetch the size of HID descriptor (ret=%d)\n",
 788                         ret);
 789                 return -ENODEV;
 790         }
 791
 792         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 793         /*
 794          * the size of the HID descriptor should at least contain
 795          * its size and the bcdVersion (4 bytes), and should not be greater
 796          * than sizeof(struct i2c_hid_desc) as we directly fill this struct
 797          * through i2c_hid_command.
 798          */
 799         if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
 800                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 801                         dsize);
 802                 return -ENODEV;
 803         }
 804
 805         /* check bcdVersion == 1.0 */
 806         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 807                 dev_err(&client->dev,
 808                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 809                         le16_to_cpu(hdesc->bcdVersion));
 810                 return -ENODEV;
 811         }
 812
 813         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 814
 815         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 816                                 dsize);
 817         if (ret) {
 818                 dev_err(&client->dev, "hid_descr_cmd Fail\n");
 819                 return -ENODEV;
 820         }
 821
 822         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 823
 824         return 0;
 825 }
 826
 827 #ifdef CONFIG_ACPI
 828 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 829                 struct i2c_hid_platform_data *pdata)
 830 {
 831         static u8 i2c_hid_guid[] = {
 832                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 833                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 834         };
 835         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
 836         union acpi_object params[4], *obj;
 837         struct acpi_object_list input;
 838         struct acpi_device *adev;
 839         acpi_handle handle;
 840
 841         handle = ACPI_HANDLE(&client->dev);
 842         if (!handle || acpi_bus_get_device(handle, &adev))
 843                 return -ENODEV;
 844
 845         input.count = ARRAY_SIZE(params);
 846         input.pointer = params;
 847
 848         params[0].type = ACPI_TYPE_BUFFER;
 849         params[0].buffer.length = sizeof(i2c_hid_guid);
 850         params[0].buffer.pointer = i2c_hid_guid;
 851         params[1].type = ACPI_TYPE_INTEGER;
 852         params[1].integer.value = 1;
 853         params[2].type = ACPI_TYPE_INTEGER;
 854         params[2].integer.value = 1; /* HID function */
 855         params[3].type = ACPI_TYPE_INTEGER;
 856         params[3].integer.value = 0;
 857
 858         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
 859                 dev_err(&client->dev, "device _DSM execution failed\n");
 860                 return -ENODEV;
 861         }
 862
 863         obj = (union acpi_object *)buf.pointer;
 864         if (obj->type != ACPI_TYPE_INTEGER) {
 865                 dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
 866                         obj->type);
 867                 kfree(buf.pointer);
 868                 return -EINVAL;
 869         }
 870
 871         pdata->hid_descriptor_address = obj->integer.value;
 872
 873         kfree(buf.pointer);
 874         return 0;
 875 }
 876
 877 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 878         {"ACPI0C50", 0 },
 879         {"PNP0C50", 0 },
 880         { },
 881 };
 882 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 883 #else
 884 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 885                 struct i2c_hid_platform_data *pdata)
 886 {
 887         return -ENODEV;
 888 }
 889 #endif
 890
 891 static int i2c_hid_probe(struct i2c_client *client,
 892                          const struct i2c_device_id *dev_id)
 893 {
 894         int ret;
 895         struct i2c_hid *ihid;
 896         struct hid_device *hid;
 897         __u16 hidRegister;
 898         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 899
 900         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 901
 902         if (!client->irq) {
 903                 dev_err(&client->dev,
 904                         "HID over i2c has not been provided an Int IRQ\n");
 905                 return -EINVAL;
 906         }
 907
 908         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 909         if (!ihid)
 910                 return -ENOMEM;
 911
 912         if (!platform_data) {
 913                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 914                 if (ret) {
 915                         dev_err(&client->dev,
 916                                 "HID register address not provided\n");
 917                         goto err;
 918                 }
 919         } else {
 920                 ihid->pdata = *platform_data;
 921         }
 922
 923         i2c_set_clientdata(client, ihid);
 924
 925         ihid->client = client;
 926
 927         hidRegister = ihid->pdata.hid_descriptor_address;
 928         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
 929
 930         init_waitqueue_head(&ihid->wait);
 931
 932         /* we need to allocate the command buffer without knowing the maximum
 933          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 934          * real computation later. */
 935         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 936         if (ret < 0)
 937                 goto err;
 938
 939         ret = i2c_hid_fetch_hid_descriptor(ihid);
 940         if (ret < 0)
 941                 goto err;
 942
 943         ret = i2c_hid_init_irq(client);
 944         if (ret < 0)
 945                 goto err;
 946
 947         hid = hid_allocate_device();
 948         if (IS_ERR(hid)) {
 949                 ret = PTR_ERR(hid);
 950                 goto err_irq;
 951         }
 952
 953         ihid->hid = hid;
 954
 955         hid->driver_data = client;
 956         hid->ll_driver = &i2c_hid_ll_driver;
 957         hid->hid_get_raw_report = i2c_hid_get_raw_report;
 958         hid->hid_output_raw_report = i2c_hid_output_raw_report;
 959         hid->dev.parent = &client->dev;
 960         ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
 961         hid->bus = BUS_I2C;
 962         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 963         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 964         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
 965
 966         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
 967                  client->name, hid->vendor, hid->product);
 968
 969         ret = hid_add_device(hid);
 970         if (ret) {
 971                 if (ret != -ENODEV)
 972                         hid_err(client, "can't add hid device: %d\n", ret);
 973                 goto err_mem_free;
 974         }
 975
 976         return 0;
 977
 978 err_mem_free:
 979         hid_destroy_device(hid);
 980
 981 err_irq:
 982         free_irq(client->irq, ihid);
 983
 984 err:
 985         i2c_hid_free_buffers(ihid);
 986         kfree(ihid);
 987         return ret;
 988 }
 989
 990 static int i2c_hid_remove(struct i2c_client *client)
 991 {
 992         struct i2c_hid *ihid = i2c_get_clientdata(client);
 993         struct hid_device *hid;
 994
 995         hid = ihid->hid;
 996         hid_destroy_device(hid);
 997
 998         free_irq(client->irq, ihid);
 999
1000         if (ihid->bufsize)
1001                 i2c_hid_free_buffers(ihid);
1002
1003         kfree(ihid);
1004
1005         return 0;
1006 }
1007
1008 #ifdef CONFIG_PM_SLEEP
1009 static int i2c_hid_suspend(struct device *dev)
1010 {
1011         struct i2c_client *client = to_i2c_client(dev);
1012
1013         if (device_may_wakeup(&client->dev))
1014                 enable_irq_wake(client->irq);
1015
1016         /* Save some power */
1017         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1018
1019         return 0;
1020 }
1021
1022 static int i2c_hid_resume(struct device *dev)
1023 {
1024         int ret;
1025         struct i2c_client *client = to_i2c_client(dev);
1026
1027         ret = i2c_hid_hwreset(client);
1028         if (ret)
1029                 return ret;
1030
1031         if (device_may_wakeup(&client->dev))
1032                 disable_irq_wake(client->irq);
1033
1034         return 0;
1035 }
1036 #endif
1037
1038 static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
1039
1040 static const struct i2c_device_id i2c_hid_id_table[] = {
1041         { "hid", 0 },
1042         { },
1043 };
1044 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1045
1046
1047 static struct i2c_driver i2c_hid_driver = {
1048         .driver = {
1049                 .name   = "i2c_hid",
1050                 .owner  = THIS_MODULE,
1051                 .pm     = &i2c_hid_pm,
1052                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1053         },
1054
1055         .probe          = i2c_hid_probe,
1056         .remove         = i2c_hid_remove,
1057
1058         .id_table       = i2c_hid_id_table,
1059 };
1060
1061 module_i2c_driver(i2c_hid_driver);
1062
1063 MODULE_DESCRIPTION("HID over I2C core driver");
1064 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1065 MODULE_LICENSE("GPL");