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 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 112
 113 /*
 114  * These definitions are not used here, but are defined by the spec.
 115  * Keeping them here for documentation purposes.
 116  *
 117  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 118  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 119  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 120  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 121  */
 122
 123 static DEFINE_MUTEX(i2c_hid_open_mut);
 124
 125 /* The main device structure */
 126 struct i2c_hid {
 127         struct i2c_client       *client;        /* i2c client */
 128         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 129         union {
 130                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 131                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 132         };
 133         __le16                  wHIDDescRegister; /* location of the i2c
 134                                                    * register of the HID
 135                                                    * descriptor. */
 136         unsigned int            bufsize;        /* i2c buffer size */
 137         char                    *inbuf;         /* Input buffer */
 138         char                    *cmdbuf;        /* Command buffer */
 139         char                    *argsbuf;       /* Command arguments buffer */
 140
 141         unsigned long           flags;          /* device flags */
 142
 143         wait_queue_head_t       wait;           /* For waiting the interrupt */
 144
 145         struct i2c_hid_platform_data pdata;
 146 };
 147
 148 static int __i2c_hid_command(struct i2c_client *client,
 149                 const struct i2c_hid_cmd *command, u8 reportID,
 150                 u8 reportType, u8 *args, int args_len,
 151                 unsigned char *buf_recv, int data_len)
 152 {
 153         struct i2c_hid *ihid = i2c_get_clientdata(client);
 154         union command *cmd = (union command *)ihid->cmdbuf;
 155         int ret;
 156         struct i2c_msg msg[2];
 157         int msg_num = 1;
 158
 159         int length = command->length;
 160         bool wait = command->wait;
 161         unsigned int registerIndex = command->registerIndex;
 162
 163         /* special case for hid_descr_cmd */
 164         if (command == &hid_descr_cmd) {
 165                 cmd->c.reg = ihid->wHIDDescRegister;
 166         } else {
 167                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 168                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 169         }
 170
 171         if (length > 2) {
 172                 cmd->c.opcode = command->opcode;
 173                 cmd->c.reportTypeID = reportID | reportType << 4;
 174         }
 175
 176         memcpy(cmd->data + length, args, args_len);
 177         length += args_len;
 178
 179         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 180
 181         msg[0].addr = client->addr;
 182         msg[0].flags = client->flags & I2C_M_TEN;
 183         msg[0].len = length;
 184         msg[0].buf = cmd->data;
 185         if (data_len > 0) {
 186                 msg[1].addr = client->addr;
 187                 msg[1].flags = client->flags & I2C_M_TEN;
 188                 msg[1].flags |= I2C_M_RD;
 189                 msg[1].len = data_len;
 190                 msg[1].buf = buf_recv;
 191                 msg_num = 2;
 192                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 193         }
 194
 195         if (wait)
 196                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 197
 198         ret = i2c_transfer(client->adapter, msg, msg_num);
 199
 200         if (data_len > 0)
 201                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 202
 203         if (ret != msg_num)
 204                 return ret < 0 ? ret : -EIO;
 205
 206         ret = 0;
 207
 208         if (wait) {
 209                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 210                 if (!wait_event_timeout(ihid->wait,
 211                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 212                                 msecs_to_jiffies(5000)))
 213                         ret = -ENODATA;
 214                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 215         }
 216
 217         return ret;
 218 }
 219
 220 static int i2c_hid_command(struct i2c_client *client,
 221                 const struct i2c_hid_cmd *command,
 222                 unsigned char *buf_recv, int data_len)
 223 {
 224         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 225                                 buf_recv, data_len);
 226 }
 227
 228 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 229                 u8 reportID, unsigned char *buf_recv, int data_len)
 230 {
 231         struct i2c_hid *ihid = i2c_get_clientdata(client);
 232         u8 args[3];
 233         int ret;
 234         int args_len = 0;
 235         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 236
 237         i2c_hid_dbg(ihid, "%s\n", __func__);
 238
 239         if (reportID >= 0x0F) {
 240                 args[args_len++] = reportID;
 241                 reportID = 0x0F;
 242         }
 243
 244         args[args_len++] = readRegister & 0xFF;
 245         args[args_len++] = readRegister >> 8;
 246
 247         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 248                 reportType, args, args_len, buf_recv, data_len);
 249         if (ret) {
 250                 dev_err(&client->dev,
 251                         "failed to retrieve report from device.\n");
 252                 return ret;
 253         }
 254
 255         return 0;
 256 }
 257
 258 static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
 259                 u8 reportID, unsigned char *buf, size_t data_len)
 260 {
 261         struct i2c_hid *ihid = i2c_get_clientdata(client);
 262         u8 *args = ihid->argsbuf;
 263         const struct i2c_hid_cmd * hidcmd = &hid_set_report_cmd;
 264         int ret;
 265         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 266         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 267         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 268
 269         /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
 270         u16 size =      2                       /* size */ +
 271                         (reportID ? 1 : 0)      /* reportID */ +
 272                         data_len                /* buf */;
 273         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 274                         2                       /* dataRegister */ +
 275                         size                    /* args */;
 276         int index = 0;
 277
 278         i2c_hid_dbg(ihid, "%s\n", __func__);
 279
 280         if (reportID >= 0x0F) {
 281                 args[index++] = reportID;
 282                 reportID = 0x0F;
 283         }
 284
 285         /*
 286          * use the data register for feature reports or if the device does not
 287          * support the output register
 288          */
 289         if (reportType == 0x03 || maxOutputLength == 0) {
 290                 args[index++] = dataRegister & 0xFF;
 291                 args[index++] = dataRegister >> 8;
 292         } else {
 293                 args[index++] = outputRegister & 0xFF;
 294                 args[index++] = outputRegister >> 8;
 295                 hidcmd = &hid_no_cmd;
 296         }
 297
 298         args[index++] = size & 0xFF;
 299         args[index++] = size >> 8;
 300
 301         if (reportID)
 302                 args[index++] = reportID;
 303
 304         memcpy(&args[index], buf, data_len);
 305
 306         ret = __i2c_hid_command(client, hidcmd, reportID,
 307                 reportType, args, args_len, NULL, 0);
 308         if (ret) {
 309                 dev_err(&client->dev, "failed to set a report to device.\n");
 310                 return ret;
 311         }
 312
 313         return data_len;
 314 }
 315
 316 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 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_command(client, &hid_set_power_cmd, power_state,
 324                 0, NULL, 0, NULL, 0);
 325         if (ret)
 326                 dev_err(&client->dev, "failed to change power setting.\n");
 327
 328         return ret;
 329 }
 330
 331 static int i2c_hid_hwreset(struct i2c_client *client)
 332 {
 333         struct i2c_hid *ihid = i2c_get_clientdata(client);
 334         int ret;
 335
 336         i2c_hid_dbg(ihid, "%s\n", __func__);
 337
 338         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 339         if (ret)
 340                 return ret;
 341
 342         i2c_hid_dbg(ihid, "resetting...\n");
 343
 344         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 345         if (ret) {
 346                 dev_err(&client->dev, "failed to reset device.\n");
 347                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 348                 return ret;
 349         }
 350
 351         return 0;
 352 }
 353
 354 static void i2c_hid_get_input(struct i2c_hid *ihid)
 355 {
 356         int ret, ret_size;
 357         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 358
 359         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 360         if (ret != size) {
 361                 if (ret < 0)
 362                         return;
 363
 364                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 365                         __func__, ret, size);
 366                 return;
 367         }
 368
 369         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 370
 371         if (!ret_size) {
 372                 /* host or device initiated RESET completed */
 373                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 374                         wake_up(&ihid->wait);
 375                 return;
 376         }
 377
 378         if (ret_size > size) {
 379                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 380                         __func__, size, ret_size);
 381                 return;
 382         }
 383
 384         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 385
 386         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 387                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 388                                 ret_size - 2, 1);
 389
 390         return;
 391 }
 392
 393 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 394 {
 395         struct i2c_hid *ihid = dev_id;
 396
 397         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 398                 return IRQ_HANDLED;
 399
 400         i2c_hid_get_input(ihid);
 401
 402         return IRQ_HANDLED;
 403 }
 404
 405 static int i2c_hid_get_report_length(struct hid_report *report)
 406 {
 407         return ((report->size - 1) >> 3) + 1 +
 408                 report->device->report_enum[report->type].numbered + 2;
 409 }
 410
 411 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 412         size_t bufsize)
 413 {
 414         struct hid_device *hid = report->device;
 415         struct i2c_client *client = hid->driver_data;
 416         struct i2c_hid *ihid = i2c_get_clientdata(client);
 417         unsigned int size, ret_size;
 418
 419         size = i2c_hid_get_report_length(report);
 420         if (i2c_hid_get_report(client,
 421                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 422                         report->id, buffer, size))
 423                 return;
 424
 425         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
 426
 427         ret_size = buffer[0] | (buffer[1] << 8);
 428
 429         if (ret_size != size) {
 430                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 431                         __func__, size, ret_size);
 432                 return;
 433         }
 434
 435         /* hid->driver_lock is held as we are in probe function,
 436          * we just need to setup the input fields, so using
 437          * hid_report_raw_event is safe. */
 438         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 439 }
 440
 441 /*
 442  * Initialize all reports
 443  */
 444 static void i2c_hid_init_reports(struct hid_device *hid)
 445 {
 446         struct hid_report *report;
 447         struct i2c_client *client = hid->driver_data;
 448         struct i2c_hid *ihid = i2c_get_clientdata(client);
 449         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 450
 451         if (!inbuf) {
 452                 dev_err(&client->dev, "can not retrieve initial reports\n");
 453                 return;
 454         }
 455
 456         list_for_each_entry(report,
 457                 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
 458                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 459
 460         list_for_each_entry(report,
 461                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 462                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 463
 464         kfree(inbuf);
 465 }
 466
 467 /*
 468  * Traverse the supplied list of reports and find the longest
 469  */
 470 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 471                 unsigned int *max)
 472 {
 473         struct hid_report *report;
 474         unsigned int size;
 475
 476         /* We should not rely on wMaxInputLength, as some devices may set it to
 477          * a wrong length. */
 478         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 479                 size = i2c_hid_get_report_length(report);
 480                 if (*max < size)
 481                         *max = size;
 482         }
 483 }
 484
 485 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 486 {
 487         kfree(ihid->inbuf);
 488         kfree(ihid->argsbuf);
 489         kfree(ihid->cmdbuf);
 490         ihid->inbuf = NULL;
 491         ihid->cmdbuf = NULL;
 492         ihid->argsbuf = NULL;
 493         ihid->bufsize = 0;
 494 }
 495
 496 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 497 {
 498         /* the worst case is computed from the set_report command with a
 499          * reportID > 15 and the maximum report length */
 500         int args_len = sizeof(__u8) + /* optional ReportID byte */
 501                        sizeof(__u16) + /* data register */
 502                        sizeof(__u16) + /* size of the report */
 503                        report_size; /* report */
 504
 505         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 506         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 507         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 508
 509         if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 510                 i2c_hid_free_buffers(ihid);
 511                 return -ENOMEM;
 512         }
 513
 514         ihid->bufsize = report_size;
 515
 516         return 0;
 517 }
 518
 519 static int i2c_hid_get_raw_report(struct hid_device *hid,
 520                 unsigned char report_number, __u8 *buf, size_t count,
 521                 unsigned char report_type)
 522 {
 523         struct i2c_client *client = hid->driver_data;
 524         struct i2c_hid *ihid = i2c_get_clientdata(client);
 525         size_t ret_count, ask_count;
 526         int ret;
 527
 528         if (report_type == HID_OUTPUT_REPORT)
 529                 return -EINVAL;
 530
 531         /* +2 bytes to include the size of the reply in the query buffer */
 532         ask_count = min(count + 2, (size_t)ihid->bufsize);
 533
 534         ret = i2c_hid_get_report(client,
 535                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 536                         report_number, ihid->inbuf, ask_count);
 537
 538         if (ret < 0)
 539                 return ret;
 540
 541         ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
 542
 543         if (ret_count <= 2)
 544                 return 0;
 545
 546         ret_count = min(ret_count, ask_count);
 547
 548         /* The query buffer contains the size, dropping it in the reply */
 549         count = min(count, ret_count - 2);
 550         memcpy(buf, ihid->inbuf + 2, count);
 551
 552         return count;
 553 }
 554
 555 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 556                 size_t count, unsigned char report_type)
 557 {
 558         struct i2c_client *client = hid->driver_data;
 559         int report_id = buf[0];
 560         int ret;
 561
 562         if (report_type == HID_INPUT_REPORT)
 563                 return -EINVAL;
 564
 565         if (report_id) {
 566                 buf++;
 567                 count--;
 568         }
 569
 570         ret = i2c_hid_set_report(client,
 571                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 572                                 report_id, buf, count);
 573
 574         if (report_id && ret >= 0)
 575                 ret++; /* add report_id to the number of transfered bytes */
 576
 577         return ret;
 578 }
 579
 580 static void i2c_hid_request(struct hid_device *hid, struct hid_report *rep,
 581                 int reqtype)
 582 {
 583         struct i2c_client *client = hid->driver_data;
 584         char *buf;
 585         int ret;
 586         int len = i2c_hid_get_report_length(rep) - 2;
 587
 588         buf = kzalloc(len, GFP_KERNEL);
 589         if (!buf)
 590                 return;
 591
 592         switch (reqtype) {
 593         case HID_REQ_GET_REPORT:
 594                 ret = i2c_hid_get_raw_report(hid, rep->id, buf, len, rep->type);
 595                 if (ret < 0)
 596                         dev_err(&client->dev, "%s: unable to get report: %d\n",
 597                                 __func__, ret);
 598                 else
 599                         hid_input_report(hid, rep->type, buf, ret, 0);
 600                 break;
 601         case HID_REQ_SET_REPORT:
 602                 hid_output_report(rep, buf);
 603                 i2c_hid_output_raw_report(hid, buf, len, rep->type);
 604                 break;
 605         }
 606
 607         kfree(buf);
 608 }
 609
 610 static int i2c_hid_parse(struct hid_device *hid)
 611 {
 612         struct i2c_client *client = hid->driver_data;
 613         struct i2c_hid *ihid = i2c_get_clientdata(client);
 614         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 615         unsigned int rsize;
 616         char *rdesc;
 617         int ret;
 618         int tries = 3;
 619
 620         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 621
 622         rsize = le16_to_cpu(hdesc->wReportDescLength);
 623         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 624                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 625                 return -EINVAL;
 626         }
 627
 628         do {
 629                 ret = i2c_hid_hwreset(client);
 630                 if (ret)
 631                         msleep(1000);
 632         } while (tries-- > 0 && ret);
 633
 634         if (ret)
 635                 return ret;
 636
 637         rdesc = kzalloc(rsize, GFP_KERNEL);
 638
 639         if (!rdesc) {
 640                 dbg_hid("couldn't allocate rdesc memory\n");
 641                 return -ENOMEM;
 642         }
 643
 644         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 645
 646         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 647         if (ret) {
 648                 hid_err(hid, "reading report descriptor failed\n");
 649                 kfree(rdesc);
 650                 return -EIO;
 651         }
 652
 653         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 654
 655         ret = hid_parse_report(hid, rdesc, rsize);
 656         kfree(rdesc);
 657         if (ret) {
 658                 dbg_hid("parsing report descriptor failed\n");
 659                 return ret;
 660         }
 661
 662         return 0;
 663 }
 664
 665 static int i2c_hid_start(struct hid_device *hid)
 666 {
 667         struct i2c_client *client = hid->driver_data;
 668         struct i2c_hid *ihid = i2c_get_clientdata(client);
 669         int ret;
 670         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 671
 672         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 673         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 674         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 675
 676         if (bufsize > ihid->bufsize) {
 677                 i2c_hid_free_buffers(ihid);
 678
 679                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 680
 681                 if (ret)
 682                         return ret;
 683         }
 684
 685         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 686                 i2c_hid_init_reports(hid);
 687
 688         return 0;
 689 }
 690
 691 static void i2c_hid_stop(struct hid_device *hid)
 692 {
 693         struct i2c_client *client = hid->driver_data;
 694         struct i2c_hid *ihid = i2c_get_clientdata(client);
 695
 696         hid->claimed = 0;
 697
 698         i2c_hid_free_buffers(ihid);
 699 }
 700
 701 static int i2c_hid_open(struct hid_device *hid)
 702 {
 703         struct i2c_client *client = hid->driver_data;
 704         struct i2c_hid *ihid = i2c_get_clientdata(client);
 705         int ret = 0;
 706
 707         mutex_lock(&i2c_hid_open_mut);
 708         if (!hid->open++) {
 709                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 710                 if (ret) {
 711                         hid->open--;
 712                         goto done;
 713                 }
 714                 set_bit(I2C_HID_STARTED, &ihid->flags);
 715         }
 716 done:
 717         mutex_unlock(&i2c_hid_open_mut);
 718         return ret;
 719 }
 720
 721 static void i2c_hid_close(struct hid_device *hid)
 722 {
 723         struct i2c_client *client = hid->driver_data;
 724         struct i2c_hid *ihid = i2c_get_clientdata(client);
 725
 726         /* protecting hid->open to make sure we don't restart
 727          * data acquistion due to a resumption we no longer
 728          * care about
 729          */
 730         mutex_lock(&i2c_hid_open_mut);
 731         if (!--hid->open) {
 732                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 733
 734                 /* Save some power */
 735                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 736         }
 737         mutex_unlock(&i2c_hid_open_mut);
 738 }
 739
 740 static int i2c_hid_power(struct hid_device *hid, int lvl)
 741 {
 742         struct i2c_client *client = hid->driver_data;
 743         struct i2c_hid *ihid = i2c_get_clientdata(client);
 744         int ret = 0;
 745
 746         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 747
 748         switch (lvl) {
 749         case PM_HINT_FULLON:
 750                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 751                 break;
 752         case PM_HINT_NORMAL:
 753                 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 754                 break;
 755         }
 756         return ret;
 757 }
 758
 759 static int i2c_hid_hidinput_input_event(struct input_dev *dev,
 760                 unsigned int type, unsigned int code, int value)
 761 {
 762         struct hid_device *hid = input_get_drvdata(dev);
 763         struct hid_field *field;
 764         int offset;
 765
 766         if (type == EV_FF)
 767                 return input_ff_event(dev, type, code, value);
 768
 769         if (type != EV_LED)
 770                 return -1;
 771
 772         offset = hidinput_find_field(hid, type, code, &field);
 773
 774         if (offset == -1) {
 775                 hid_warn(dev, "event field not found\n");
 776                 return -1;
 777         }
 778
 779         return hid_set_field(field, offset, value);
 780 }
 781
 782 static struct hid_ll_driver i2c_hid_ll_driver = {
 783         .parse = i2c_hid_parse,
 784         .start = i2c_hid_start,
 785         .stop = i2c_hid_stop,
 786         .open = i2c_hid_open,
 787         .close = i2c_hid_close,
 788         .power = i2c_hid_power,
 789         .request = i2c_hid_request,
 790         .hidinput_input_event = i2c_hid_hidinput_input_event,
 791 };
 792
 793 static int i2c_hid_init_irq(struct i2c_client *client)
 794 {
 795         struct i2c_hid *ihid = i2c_get_clientdata(client);
 796         int ret;
 797
 798         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 799
 800         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 801                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 802                         client->name, ihid);
 803         if (ret < 0) {
 804                 dev_warn(&client->dev,
 805                         "Could not register for %s interrupt, irq = %d,"
 806                         " ret = %d\n",
 807                         client->name, client->irq, ret);
 808
 809                 return ret;
 810         }
 811
 812         return 0;
 813 }
 814
 815 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 816 {
 817         struct i2c_client *client = ihid->client;
 818         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 819         unsigned int dsize;
 820         int ret;
 821
 822         /* Fetch the length of HID description, retrieve the 4 first bytes:
 823          * bytes 0-1 -> length
 824          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 825         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
 826
 827         i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %*ph\n",
 828                         __func__, 4, ihid->hdesc_buffer);
 829
 830         if (ret) {
 831                 dev_err(&client->dev,
 832                         "unable to fetch the size of HID descriptor (ret=%d)\n",
 833                         ret);
 834                 return -ENODEV;
 835         }
 836
 837         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 838         /*
 839          * the size of the HID descriptor should at least contain
 840          * its size and the bcdVersion (4 bytes), and should not be greater
 841          * than sizeof(struct i2c_hid_desc) as we directly fill this struct
 842          * through i2c_hid_command.
 843          */
 844         if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
 845                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 846                         dsize);
 847                 return -ENODEV;
 848         }
 849
 850         /* check bcdVersion == 1.0 */
 851         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 852                 dev_err(&client->dev,
 853                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 854                         le16_to_cpu(hdesc->bcdVersion));
 855                 return -ENODEV;
 856         }
 857
 858         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 859
 860         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 861                                 dsize);
 862         if (ret) {
 863                 dev_err(&client->dev, "hid_descr_cmd Fail\n");
 864                 return -ENODEV;
 865         }
 866
 867         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 868
 869         return 0;
 870 }
 871
 872 #ifdef CONFIG_ACPI
 873 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 874                 struct i2c_hid_platform_data *pdata)
 875 {
 876         static u8 i2c_hid_guid[] = {
 877                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 878                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 879         };
 880         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
 881         union acpi_object params[4], *obj;
 882         struct acpi_object_list input;
 883         struct acpi_device *adev;
 884         acpi_handle handle;
 885
 886         handle = ACPI_HANDLE(&client->dev);
 887         if (!handle || acpi_bus_get_device(handle, &adev))
 888                 return -ENODEV;
 889
 890         input.count = ARRAY_SIZE(params);
 891         input.pointer = params;
 892
 893         params[0].type = ACPI_TYPE_BUFFER;
 894         params[0].buffer.length = sizeof(i2c_hid_guid);
 895         params[0].buffer.pointer = i2c_hid_guid;
 896         params[1].type = ACPI_TYPE_INTEGER;
 897         params[1].integer.value = 1;
 898         params[2].type = ACPI_TYPE_INTEGER;
 899         params[2].integer.value = 1; /* HID function */
 900         params[3].type = ACPI_TYPE_INTEGER;
 901         params[3].integer.value = 0;
 902
 903         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
 904                 dev_err(&client->dev, "device _DSM execution failed\n");
 905                 return -ENODEV;
 906         }
 907
 908         obj = (union acpi_object *)buf.pointer;
 909         if (obj->type != ACPI_TYPE_INTEGER) {
 910                 dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
 911                         obj->type);
 912                 kfree(buf.pointer);
 913                 return -EINVAL;
 914         }
 915
 916         pdata->hid_descriptor_address = obj->integer.value;
 917
 918         kfree(buf.pointer);
 919         return 0;
 920 }
 921
 922 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 923         {"ACPI0C50", 0 },
 924         {"PNP0C50", 0 },
 925         { },
 926 };
 927 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 928 #else
 929 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 930                 struct i2c_hid_platform_data *pdata)
 931 {
 932         return -ENODEV;
 933 }
 934 #endif
 935
 936 static int i2c_hid_probe(struct i2c_client *client,
 937                          const struct i2c_device_id *dev_id)
 938 {
 939         int ret;
 940         struct i2c_hid *ihid;
 941         struct hid_device *hid;
 942         __u16 hidRegister;
 943         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 944
 945         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 946
 947         if (!client->irq) {
 948                 dev_err(&client->dev,
 949                         "HID over i2c has not been provided an Int IRQ\n");
 950                 return -EINVAL;
 951         }
 952
 953         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 954         if (!ihid)
 955                 return -ENOMEM;
 956
 957         if (!platform_data) {
 958                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 959                 if (ret) {
 960                         dev_err(&client->dev,
 961                                 "HID register address not provided\n");
 962                         goto err;
 963                 }
 964         } else {
 965                 ihid->pdata = *platform_data;
 966         }
 967
 968         i2c_set_clientdata(client, ihid);
 969
 970         ihid->client = client;
 971
 972         hidRegister = ihid->pdata.hid_descriptor_address;
 973         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
 974
 975         init_waitqueue_head(&ihid->wait);
 976
 977         /* we need to allocate the command buffer without knowing the maximum
 978          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 979          * real computation later. */
 980         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 981         if (ret < 0)
 982                 goto err;
 983
 984         ret = i2c_hid_fetch_hid_descriptor(ihid);
 985         if (ret < 0)
 986                 goto err;
 987
 988         ret = i2c_hid_init_irq(client);
 989         if (ret < 0)
 990                 goto err;
 991
 992         hid = hid_allocate_device();
 993         if (IS_ERR(hid)) {
 994                 ret = PTR_ERR(hid);
 995                 goto err_irq;
 996         }
 997
 998         ihid->hid = hid;
 999
1000         hid->driver_data = client;
1001         hid->ll_driver = &i2c_hid_ll_driver;
1002         hid->hid_get_raw_report = i2c_hid_get_raw_report;
1003         hid->hid_output_raw_report = i2c_hid_output_raw_report;
1004         hid->dev.parent = &client->dev;
1005         ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
1006         hid->bus = BUS_I2C;
1007         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1008         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1009         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1010
1011         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1012                  client->name, hid->vendor, hid->product);
1013
1014         ret = hid_add_device(hid);
1015         if (ret) {
1016                 if (ret != -ENODEV)
1017                         hid_err(client, "can't add hid device: %d\n", ret);
1018                 goto err_mem_free;
1019         }
1020
1021         return 0;
1022
1023 err_mem_free:
1024         hid_destroy_device(hid);
1025
1026 err_irq:
1027         free_irq(client->irq, ihid);
1028
1029 err:
1030         i2c_hid_free_buffers(ihid);
1031         kfree(ihid);
1032         return ret;
1033 }
1034
1035 static int i2c_hid_remove(struct i2c_client *client)
1036 {
1037         struct i2c_hid *ihid = i2c_get_clientdata(client);
1038         struct hid_device *hid;
1039
1040         hid = ihid->hid;
1041         hid_destroy_device(hid);
1042
1043         free_irq(client->irq, ihid);
1044
1045         if (ihid->bufsize)
1046                 i2c_hid_free_buffers(ihid);
1047
1048         kfree(ihid);
1049
1050         return 0;
1051 }
1052
1053 #ifdef CONFIG_PM_SLEEP
1054 static int i2c_hid_suspend(struct device *dev)
1055 {
1056         struct i2c_client *client = to_i2c_client(dev);
1057
1058         if (device_may_wakeup(&client->dev))
1059                 enable_irq_wake(client->irq);
1060
1061         /* Save some power */
1062         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1063
1064         return 0;
1065 }
1066
1067 static int i2c_hid_resume(struct device *dev)
1068 {
1069         int ret;
1070         struct i2c_client *client = to_i2c_client(dev);
1071
1072         ret = i2c_hid_hwreset(client);
1073         if (ret)
1074                 return ret;
1075
1076         if (device_may_wakeup(&client->dev))
1077                 disable_irq_wake(client->irq);
1078
1079         return 0;
1080 }
1081 #endif
1082
1083 static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
1084
1085 static const struct i2c_device_id i2c_hid_id_table[] = {
1086         { "hid", 0 },
1087         { },
1088 };
1089 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1090
1091
1092 static struct i2c_driver i2c_hid_driver = {
1093         .driver = {
1094                 .name   = "i2c_hid",
1095                 .owner  = THIS_MODULE,
1096                 .pm     = &i2c_hid_pm,
1097                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1098         },
1099
1100         .probe          = i2c_hid_probe,
1101         .remove         = i2c_hid_remove,
1102
1103         .id_table       = i2c_hid_id_table,
1104 };
1105
1106 module_i2c_driver(i2c_hid_driver);
1107
1108 MODULE_DESCRIPTION("HID over I2C core driver");
1109 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1110 MODULE_LICENSE("GPL");