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/pm_runtime.h>
  29 #include <linux/device.h>
  30 #include <linux/wait.h>
  31 #include <linux/err.h>
  32 #include <linux/string.h>
  33 #include <linux/list.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/kernel.h>
  36 #include <linux/hid.h>
  37 #include <linux/mutex.h>
  38 #include <linux/acpi.h>
  39 #include <linux/of.h>
  40
  41 #include <linux/i2c/i2c-hid.h>
  42
  43 /* flags */
  44 #define I2C_HID_STARTED         (1 << 0)
  45 #define I2C_HID_RESET_PENDING   (1 << 1)
  46 #define I2C_HID_READ_PENDING    (1 << 2)
  47
  48 #define I2C_HID_PWR_ON          0x00
  49 #define I2C_HID_PWR_SLEEP       0x01
  50
  51 /* debug option */
  52 static bool debug;
  53 module_param(debug, bool, 0444);
  54 MODULE_PARM_DESC(debug, "print a lot of debug information");
  55
  56 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  57 do {                                                                      \
  58         if (debug)                                                        \
  59                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  60 } while (0)
  61
  62 struct i2c_hid_desc {
  63         __le16 wHIDDescLength;
  64         __le16 bcdVersion;
  65         __le16 wReportDescLength;
  66         __le16 wReportDescRegister;
  67         __le16 wInputRegister;
  68         __le16 wMaxInputLength;
  69         __le16 wOutputRegister;
  70         __le16 wMaxOutputLength;
  71         __le16 wCommandRegister;
  72         __le16 wDataRegister;
  73         __le16 wVendorID;
  74         __le16 wProductID;
  75         __le16 wVersionID;
  76         __le32 reserved;
  77 } __packed;
  78
  79 struct i2c_hid_cmd {
  80         unsigned int registerIndex;
  81         __u8 opcode;
  82         unsigned int length;
  83         bool wait;
  84 };
  85
  86 union command {
  87         u8 data[0];
  88         struct cmd {
  89                 __le16 reg;
  90                 __u8 reportTypeID;
  91                 __u8 opcode;
  92         } __packed c;
  93 };
  94
  95 #define I2C_HID_CMD(opcode_) \
  96         .opcode = opcode_, .length = 4, \
  97         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
  98
  99 /* fetch HID descriptor */
 100 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 101 /* fetch report descriptors */
 102 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 103                 .registerIndex = offsetof(struct i2c_hid_desc,
 104                         wReportDescRegister),
 105                 .opcode = 0x00,
 106                 .length = 2 };
 107 /* commands */
 108 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 109                                                           .wait = true };
 110 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 111 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 112 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 113 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 114
 115 /*
 116  * These definitions are not used here, but are defined by the spec.
 117  * Keeping them here for documentation purposes.
 118  *
 119  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 120  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 121  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 122  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 123  */
 124
 125 static DEFINE_MUTEX(i2c_hid_open_mut);
 126
 127 /* The main device structure */
 128 struct i2c_hid {
 129         struct i2c_client       *client;        /* i2c client */
 130         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 131         union {
 132                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 133                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 134         };
 135         __le16                  wHIDDescRegister; /* location of the i2c
 136                                                    * register of the HID
 137                                                    * descriptor. */
 138         unsigned int            bufsize;        /* i2c buffer size */
 139         char                    *inbuf;         /* Input buffer */
 140         char                    *rawbuf;        /* Raw Input buffer */
 141         char                    *cmdbuf;        /* Command buffer */
 142         char                    *argsbuf;       /* Command arguments buffer */
 143
 144         unsigned long           flags;          /* device flags */
 145
 146         wait_queue_head_t       wait;           /* For waiting the interrupt */
 147
 148         struct i2c_hid_platform_data pdata;
 149 };
 150
 151 static int __i2c_hid_command(struct i2c_client *client,
 152                 const struct i2c_hid_cmd *command, u8 reportID,
 153                 u8 reportType, u8 *args, int args_len,
 154                 unsigned char *buf_recv, int data_len)
 155 {
 156         struct i2c_hid *ihid = i2c_get_clientdata(client);
 157         union command *cmd = (union command *)ihid->cmdbuf;
 158         int ret;
 159         struct i2c_msg msg[2];
 160         int msg_num = 1;
 161
 162         int length = command->length;
 163         bool wait = command->wait;
 164         unsigned int registerIndex = command->registerIndex;
 165
 166         /* special case for hid_descr_cmd */
 167         if (command == &hid_descr_cmd) {
 168                 cmd->c.reg = ihid->wHIDDescRegister;
 169         } else {
 170                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 171                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 172         }
 173
 174         if (length > 2) {
 175                 cmd->c.opcode = command->opcode;
 176                 cmd->c.reportTypeID = reportID | reportType << 4;
 177         }
 178
 179         memcpy(cmd->data + length, args, args_len);
 180         length += args_len;
 181
 182         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 183
 184         msg[0].addr = client->addr;
 185         msg[0].flags = client->flags & I2C_M_TEN;
 186         msg[0].len = length;
 187         msg[0].buf = cmd->data;
 188         if (data_len > 0) {
 189                 msg[1].addr = client->addr;
 190                 msg[1].flags = client->flags & I2C_M_TEN;
 191                 msg[1].flags |= I2C_M_RD;
 192                 msg[1].len = data_len;
 193                 msg[1].buf = buf_recv;
 194                 msg_num = 2;
 195                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 196         }
 197
 198         if (wait)
 199                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 200
 201         ret = i2c_transfer(client->adapter, msg, msg_num);
 202
 203         if (data_len > 0)
 204                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 205
 206         if (ret != msg_num)
 207                 return ret < 0 ? ret : -EIO;
 208
 209         ret = 0;
 210
 211         if (wait) {
 212                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 213                 if (!wait_event_timeout(ihid->wait,
 214                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 215                                 msecs_to_jiffies(5000)))
 216                         ret = -ENODATA;
 217                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 218         }
 219
 220         return ret;
 221 }
 222
 223 static int i2c_hid_command(struct i2c_client *client,
 224                 const struct i2c_hid_cmd *command,
 225                 unsigned char *buf_recv, int data_len)
 226 {
 227         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 228                                 buf_recv, data_len);
 229 }
 230
 231 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 232                 u8 reportID, unsigned char *buf_recv, int data_len)
 233 {
 234         struct i2c_hid *ihid = i2c_get_clientdata(client);
 235         u8 args[3];
 236         int ret;
 237         int args_len = 0;
 238         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 239
 240         i2c_hid_dbg(ihid, "%s\n", __func__);
 241
 242         if (reportID >= 0x0F) {
 243                 args[args_len++] = reportID;
 244                 reportID = 0x0F;
 245         }
 246
 247         args[args_len++] = readRegister & 0xFF;
 248         args[args_len++] = readRegister >> 8;
 249
 250         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 251                 reportType, args, args_len, buf_recv, data_len);
 252         if (ret) {
 253                 dev_err(&client->dev,
 254                         "failed to retrieve report from device.\n");
 255                 return ret;
 256         }
 257
 258         return 0;
 259 }
 260
 261 /**
 262  * i2c_hid_set_or_send_report: forward an incoming report to the device
 263  * @client: the i2c_client of the device
 264  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 265  * @reportID: the report ID
 266  * @buf: the actual data to transfer, without the report ID
 267  * @len: size of buf
 268  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 269  */
 270 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 271                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 272 {
 273         struct i2c_hid *ihid = i2c_get_clientdata(client);
 274         u8 *args = ihid->argsbuf;
 275         const struct i2c_hid_cmd *hidcmd;
 276         int ret;
 277         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 278         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 279         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 280
 281         /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
 282         u16 size =      2                       /* size */ +
 283                         (reportID ? 1 : 0)      /* reportID */ +
 284                         data_len                /* buf */;
 285         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 286                         2                       /* dataRegister */ +
 287                         size                    /* args */;
 288         int index = 0;
 289
 290         i2c_hid_dbg(ihid, "%s\n", __func__);
 291
 292         if (!use_data && maxOutputLength == 0)
 293                 return -ENOSYS;
 294
 295         if (reportID >= 0x0F) {
 296                 args[index++] = reportID;
 297                 reportID = 0x0F;
 298         }
 299
 300         /*
 301          * use the data register for feature reports or if the device does not
 302          * support the output register
 303          */
 304         if (use_data) {
 305                 args[index++] = dataRegister & 0xFF;
 306                 args[index++] = dataRegister >> 8;
 307                 hidcmd = &hid_set_report_cmd;
 308         } else {
 309                 args[index++] = outputRegister & 0xFF;
 310                 args[index++] = outputRegister >> 8;
 311                 hidcmd = &hid_no_cmd;
 312         }
 313
 314         args[index++] = size & 0xFF;
 315         args[index++] = size >> 8;
 316
 317         if (reportID)
 318                 args[index++] = reportID;
 319
 320         memcpy(&args[index], buf, data_len);
 321
 322         ret = __i2c_hid_command(client, hidcmd, reportID,
 323                 reportType, args, args_len, NULL, 0);
 324         if (ret) {
 325                 dev_err(&client->dev, "failed to set a report to device.\n");
 326                 return ret;
 327         }
 328
 329         return data_len;
 330 }
 331
 332 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 333 {
 334         struct i2c_hid *ihid = i2c_get_clientdata(client);
 335         int ret;
 336
 337         i2c_hid_dbg(ihid, "%s\n", __func__);
 338
 339         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 340                 0, NULL, 0, NULL, 0);
 341         if (ret)
 342                 dev_err(&client->dev, "failed to change power setting.\n");
 343
 344         return ret;
 345 }
 346
 347 static int i2c_hid_hwreset(struct i2c_client *client)
 348 {
 349         struct i2c_hid *ihid = i2c_get_clientdata(client);
 350         int ret;
 351
 352         i2c_hid_dbg(ihid, "%s\n", __func__);
 353
 354         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 355         if (ret)
 356                 return ret;
 357
 358         i2c_hid_dbg(ihid, "resetting...\n");
 359
 360         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 361         if (ret) {
 362                 dev_err(&client->dev, "failed to reset device.\n");
 363                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 364                 return ret;
 365         }
 366
 367         return 0;
 368 }
 369
 370 static void i2c_hid_get_input(struct i2c_hid *ihid)
 371 {
 372         int ret, ret_size;
 373         int size = ihid->bufsize;
 374
 375         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 376         if (ret != size) {
 377                 if (ret < 0)
 378                         return;
 379
 380                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 381                         __func__, ret, size);
 382                 return;
 383         }
 384
 385         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 386
 387         if (!ret_size) {
 388                 /* host or device initiated RESET completed */
 389                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 390                         wake_up(&ihid->wait);
 391                 return;
 392         }
 393
 394         if (ret_size > size) {
 395                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 396                         __func__, size, ret_size);
 397                 return;
 398         }
 399
 400         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 401
 402         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 403                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 404                                 ret_size - 2, 1);
 405
 406         return;
 407 }
 408
 409 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 410 {
 411         struct i2c_hid *ihid = dev_id;
 412
 413         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 414                 return IRQ_HANDLED;
 415
 416         i2c_hid_get_input(ihid);
 417
 418         return IRQ_HANDLED;
 419 }
 420
 421 static int i2c_hid_get_report_length(struct hid_report *report)
 422 {
 423         return ((report->size - 1) >> 3) + 1 +
 424                 report->device->report_enum[report->type].numbered + 2;
 425 }
 426
 427 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 428         size_t bufsize)
 429 {
 430         struct hid_device *hid = report->device;
 431         struct i2c_client *client = hid->driver_data;
 432         struct i2c_hid *ihid = i2c_get_clientdata(client);
 433         unsigned int size, ret_size;
 434
 435         size = i2c_hid_get_report_length(report);
 436         if (i2c_hid_get_report(client,
 437                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 438                         report->id, buffer, size))
 439                 return;
 440
 441         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
 442
 443         ret_size = buffer[0] | (buffer[1] << 8);
 444
 445         if (ret_size != size) {
 446                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 447                         __func__, size, ret_size);
 448                 return;
 449         }
 450
 451         /* hid->driver_lock is held as we are in probe function,
 452          * we just need to setup the input fields, so using
 453          * hid_report_raw_event is safe. */
 454         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 455 }
 456
 457 /*
 458  * Initialize all reports
 459  */
 460 static void i2c_hid_init_reports(struct hid_device *hid)
 461 {
 462         struct hid_report *report;
 463         struct i2c_client *client = hid->driver_data;
 464         struct i2c_hid *ihid = i2c_get_clientdata(client);
 465         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 466
 467         if (!inbuf) {
 468                 dev_err(&client->dev, "can not retrieve initial reports\n");
 469                 return;
 470         }
 471
 472         /*
 473          * The device must be powered on while we fetch initial reports
 474          * from it.
 475          */
 476         pm_runtime_get_sync(&client->dev);
 477
 478         list_for_each_entry(report,
 479                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 480                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 481
 482         pm_runtime_put(&client->dev);
 483
 484         kfree(inbuf);
 485 }
 486
 487 /*
 488  * Traverse the supplied list of reports and find the longest
 489  */
 490 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 491                 unsigned int *max)
 492 {
 493         struct hid_report *report;
 494         unsigned int size;
 495
 496         /* We should not rely on wMaxInputLength, as some devices may set it to
 497          * a wrong length. */
 498         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 499                 size = i2c_hid_get_report_length(report);
 500                 if (*max < size)
 501                         *max = size;
 502         }
 503 }
 504
 505 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 506 {
 507         kfree(ihid->inbuf);
 508         kfree(ihid->rawbuf);
 509         kfree(ihid->argsbuf);
 510         kfree(ihid->cmdbuf);
 511         ihid->inbuf = NULL;
 512         ihid->rawbuf = NULL;
 513         ihid->cmdbuf = NULL;
 514         ihid->argsbuf = NULL;
 515         ihid->bufsize = 0;
 516 }
 517
 518 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 519 {
 520         /* the worst case is computed from the set_report command with a
 521          * reportID > 15 and the maximum report length */
 522         int args_len = sizeof(__u8) + /* optional ReportID byte */
 523                        sizeof(__u16) + /* data register */
 524                        sizeof(__u16) + /* size of the report */
 525                        report_size; /* report */
 526
 527         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 528         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 529         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 530         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 531
 532         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 533                 i2c_hid_free_buffers(ihid);
 534                 return -ENOMEM;
 535         }
 536
 537         ihid->bufsize = report_size;
 538
 539         return 0;
 540 }
 541
 542 static int i2c_hid_get_raw_report(struct hid_device *hid,
 543                 unsigned char report_number, __u8 *buf, size_t count,
 544                 unsigned char report_type)
 545 {
 546         struct i2c_client *client = hid->driver_data;
 547         struct i2c_hid *ihid = i2c_get_clientdata(client);
 548         size_t ret_count, ask_count;
 549         int ret;
 550
 551         if (report_type == HID_OUTPUT_REPORT)
 552                 return -EINVAL;
 553
 554         /* +2 bytes to include the size of the reply in the query buffer */
 555         ask_count = min(count + 2, (size_t)ihid->bufsize);
 556
 557         ret = i2c_hid_get_report(client,
 558                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 559                         report_number, ihid->rawbuf, ask_count);
 560
 561         if (ret < 0)
 562                 return ret;
 563
 564         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 565
 566         if (ret_count <= 2)
 567                 return 0;
 568
 569         ret_count = min(ret_count, ask_count);
 570
 571         /* The query buffer contains the size, dropping it in the reply */
 572         count = min(count, ret_count - 2);
 573         memcpy(buf, ihid->rawbuf + 2, count);
 574
 575         return count;
 576 }
 577
 578 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 579                 size_t count, unsigned char report_type, bool use_data)
 580 {
 581         struct i2c_client *client = hid->driver_data;
 582         int report_id = buf[0];
 583         int ret;
 584
 585         if (report_type == HID_INPUT_REPORT)
 586                 return -EINVAL;
 587
 588         if (report_id) {
 589                 buf++;
 590                 count--;
 591         }
 592
 593         ret = i2c_hid_set_or_send_report(client,
 594                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 595                                 report_id, buf, count, use_data);
 596
 597         if (report_id && ret >= 0)
 598                 ret++; /* add report_id to the number of transfered bytes */
 599
 600         return ret;
 601 }
 602
 603 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 604                 size_t count)
 605 {
 606         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 607                         false);
 608 }
 609
 610 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 611                                __u8 *buf, size_t len, unsigned char rtype,
 612                                int reqtype)
 613 {
 614         switch (reqtype) {
 615         case HID_REQ_GET_REPORT:
 616                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 617         case HID_REQ_SET_REPORT:
 618                 if (buf[0] != reportnum)
 619                         return -EINVAL;
 620                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 621         default:
 622                 return -EIO;
 623         }
 624 }
 625
 626 static int i2c_hid_parse(struct hid_device *hid)
 627 {
 628         struct i2c_client *client = hid->driver_data;
 629         struct i2c_hid *ihid = i2c_get_clientdata(client);
 630         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 631         unsigned int rsize;
 632         char *rdesc;
 633         int ret;
 634         int tries = 3;
 635
 636         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 637
 638         rsize = le16_to_cpu(hdesc->wReportDescLength);
 639         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 640                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 641                 return -EINVAL;
 642         }
 643
 644         do {
 645                 ret = i2c_hid_hwreset(client);
 646                 if (ret)
 647                         msleep(1000);
 648         } while (tries-- > 0 && ret);
 649
 650         if (ret)
 651                 return ret;
 652
 653         rdesc = kzalloc(rsize, GFP_KERNEL);
 654
 655         if (!rdesc) {
 656                 dbg_hid("couldn't allocate rdesc memory\n");
 657                 return -ENOMEM;
 658         }
 659
 660         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 661
 662         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 663         if (ret) {
 664                 hid_err(hid, "reading report descriptor failed\n");
 665                 kfree(rdesc);
 666                 return -EIO;
 667         }
 668
 669         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 670
 671         ret = hid_parse_report(hid, rdesc, rsize);
 672         kfree(rdesc);
 673         if (ret) {
 674                 dbg_hid("parsing report descriptor failed\n");
 675                 return ret;
 676         }
 677
 678         return 0;
 679 }
 680
 681 static int i2c_hid_start(struct hid_device *hid)
 682 {
 683         struct i2c_client *client = hid->driver_data;
 684         struct i2c_hid *ihid = i2c_get_clientdata(client);
 685         int ret;
 686         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 687
 688         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 689         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 690         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 691
 692         if (bufsize > ihid->bufsize) {
 693                 i2c_hid_free_buffers(ihid);
 694
 695                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 696
 697                 if (ret)
 698                         return ret;
 699         }
 700
 701         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 702                 i2c_hid_init_reports(hid);
 703
 704         return 0;
 705 }
 706
 707 static void i2c_hid_stop(struct hid_device *hid)
 708 {
 709         hid->claimed = 0;
 710 }
 711
 712 static int i2c_hid_open(struct hid_device *hid)
 713 {
 714         struct i2c_client *client = hid->driver_data;
 715         struct i2c_hid *ihid = i2c_get_clientdata(client);
 716         int ret = 0;
 717
 718         mutex_lock(&i2c_hid_open_mut);
 719         if (!hid->open++) {
 720                 ret = pm_runtime_get_sync(&client->dev);
 721                 if (ret < 0) {
 722                         hid->open--;
 723                         goto done;
 724                 }
 725                 set_bit(I2C_HID_STARTED, &ihid->flags);
 726         }
 727 done:
 728         mutex_unlock(&i2c_hid_open_mut);
 729         return ret < 0 ? ret : 0;
 730 }
 731
 732 static void i2c_hid_close(struct hid_device *hid)
 733 {
 734         struct i2c_client *client = hid->driver_data;
 735         struct i2c_hid *ihid = i2c_get_clientdata(client);
 736
 737         /* protecting hid->open to make sure we don't restart
 738          * data acquistion due to a resumption we no longer
 739          * care about
 740          */
 741         mutex_lock(&i2c_hid_open_mut);
 742         if (!--hid->open) {
 743                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 744
 745                 /* Save some power */
 746                 pm_runtime_put(&client->dev);
 747         }
 748         mutex_unlock(&i2c_hid_open_mut);
 749 }
 750
 751 static int i2c_hid_power(struct hid_device *hid, int lvl)
 752 {
 753         struct i2c_client *client = hid->driver_data;
 754         struct i2c_hid *ihid = i2c_get_clientdata(client);
 755
 756         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 757
 758         switch (lvl) {
 759         case PM_HINT_FULLON:
 760                 pm_runtime_get_sync(&client->dev);
 761                 break;
 762         case PM_HINT_NORMAL:
 763                 pm_runtime_put(&client->dev);
 764                 break;
 765         }
 766         return 0;
 767 }
 768
 769 static struct hid_ll_driver i2c_hid_ll_driver = {
 770         .parse = i2c_hid_parse,
 771         .start = i2c_hid_start,
 772         .stop = i2c_hid_stop,
 773         .open = i2c_hid_open,
 774         .close = i2c_hid_close,
 775         .power = i2c_hid_power,
 776         .output_report = i2c_hid_output_report,
 777         .raw_request = i2c_hid_raw_request,
 778 };
 779
 780 static int i2c_hid_init_irq(struct i2c_client *client)
 781 {
 782         struct i2c_hid *ihid = i2c_get_clientdata(client);
 783         int ret;
 784
 785         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 786
 787         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 788                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 789                         client->name, ihid);
 790         if (ret < 0) {
 791                 dev_warn(&client->dev,
 792                         "Could not register for %s interrupt, irq = %d,"
 793                         " ret = %d\n",
 794                         client->name, client->irq, ret);
 795
 796                 return ret;
 797         }
 798
 799         return 0;
 800 }
 801
 802 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 803 {
 804         struct i2c_client *client = ihid->client;
 805         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 806         unsigned int dsize;
 807         int ret;
 808
 809         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 810         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 811         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 812                                 sizeof(struct i2c_hid_desc));
 813         if (ret) {
 814                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 815                 return -ENODEV;
 816         }
 817
 818         /* Validate the length of HID descriptor, the 4 first bytes:
 819          * bytes 0-1 -> length
 820          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 821         /* check bcdVersion == 1.0 */
 822         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 823                 dev_err(&client->dev,
 824                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 825                         le16_to_cpu(hdesc->bcdVersion));
 826                 return -ENODEV;
 827         }
 828
 829         /* Descriptor length should be 30 bytes as per the specification */
 830         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 831         if (dsize != sizeof(struct i2c_hid_desc)) {
 832                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 833                         dsize);
 834                 return -ENODEV;
 835         }
 836         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 837         return 0;
 838 }
 839
 840 #ifdef CONFIG_ACPI
 841 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 842                 struct i2c_hid_platform_data *pdata)
 843 {
 844         static u8 i2c_hid_guid[] = {
 845                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 846                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 847         };
 848         union acpi_object *obj;
 849         struct acpi_device *adev;
 850         acpi_handle handle;
 851
 852         handle = ACPI_HANDLE(&client->dev);
 853         if (!handle || acpi_bus_get_device(handle, &adev))
 854                 return -ENODEV;
 855
 856         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 857                                       ACPI_TYPE_INTEGER);
 858         if (!obj) {
 859                 dev_err(&client->dev, "device _DSM execution failed\n");
 860                 return -ENODEV;
 861         }
 862
 863         pdata->hid_descriptor_address = obj->integer.value;
 864         ACPI_FREE(obj);
 865
 866         return 0;
 867 }
 868
 869 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 870         {"ACPI0C50", 0 },
 871         {"PNP0C50", 0 },
 872         { },
 873 };
 874 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 875 #else
 876 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 877                 struct i2c_hid_platform_data *pdata)
 878 {
 879         return -ENODEV;
 880 }
 881 #endif
 882
 883 #ifdef CONFIG_OF
 884 static int i2c_hid_of_probe(struct i2c_client *client,
 885                 struct i2c_hid_platform_data *pdata)
 886 {
 887         struct device *dev = &client->dev;
 888         u32 val;
 889         int ret;
 890
 891         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 892         if (ret) {
 893                 dev_err(&client->dev, "HID register address not provided\n");
 894                 return -ENODEV;
 895         }
 896         if (val >> 16) {
 897                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 898                         val);
 899                 return -EINVAL;
 900         }
 901         pdata->hid_descriptor_address = val;
 902
 903         return 0;
 904 }
 905
 906 static const struct of_device_id i2c_hid_of_match[] = {
 907         { .compatible = "hid-over-i2c" },
 908         {},
 909 };
 910 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 911 #else
 912 static inline int i2c_hid_of_probe(struct i2c_client *client,
 913                 struct i2c_hid_platform_data *pdata)
 914 {
 915         return -ENODEV;
 916 }
 917 #endif
 918
 919 static int i2c_hid_probe(struct i2c_client *client,
 920                          const struct i2c_device_id *dev_id)
 921 {
 922         int ret;
 923         struct i2c_hid *ihid;
 924         struct hid_device *hid;
 925         __u16 hidRegister;
 926         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 927
 928         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 929
 930         if (!client->irq) {
 931                 dev_err(&client->dev,
 932                         "HID over i2c has not been provided an Int IRQ\n");
 933                 return -EINVAL;
 934         }
 935
 936         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 937         if (!ihid)
 938                 return -ENOMEM;
 939
 940         if (client->dev.of_node) {
 941                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 942                 if (ret)
 943                         goto err;
 944         } else if (!platform_data) {
 945                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 946                 if (ret) {
 947                         dev_err(&client->dev,
 948                                 "HID register address not provided\n");
 949                         goto err;
 950                 }
 951         } else {
 952                 ihid->pdata = *platform_data;
 953         }
 954
 955         i2c_set_clientdata(client, ihid);
 956
 957         ihid->client = client;
 958
 959         hidRegister = ihid->pdata.hid_descriptor_address;
 960         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
 961
 962         init_waitqueue_head(&ihid->wait);
 963
 964         /* we need to allocate the command buffer without knowing the maximum
 965          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 966          * real computation later. */
 967         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 968         if (ret < 0)
 969                 goto err;
 970
 971         pm_runtime_get_noresume(&client->dev);
 972         pm_runtime_set_active(&client->dev);
 973         pm_runtime_enable(&client->dev);
 974
 975         ret = i2c_hid_fetch_hid_descriptor(ihid);
 976         if (ret < 0)
 977                 goto err_pm;
 978
 979         ret = i2c_hid_init_irq(client);
 980         if (ret < 0)
 981                 goto err_pm;
 982
 983         hid = hid_allocate_device();
 984         if (IS_ERR(hid)) {
 985                 ret = PTR_ERR(hid);
 986                 goto err_irq;
 987         }
 988
 989         ihid->hid = hid;
 990
 991         hid->driver_data = client;
 992         hid->ll_driver = &i2c_hid_ll_driver;
 993         hid->dev.parent = &client->dev;
 994         ACPI_COMPANION_SET(&hid->dev, ACPI_COMPANION(&client->dev));
 995         hid->bus = BUS_I2C;
 996         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 997         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 998         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
 999
1000         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1001                  client->name, hid->vendor, hid->product);
1002
1003         ret = hid_add_device(hid);
1004         if (ret) {
1005                 if (ret != -ENODEV)
1006                         hid_err(client, "can't add hid device: %d\n", ret);
1007                 goto err_mem_free;
1008         }
1009
1010         pm_runtime_put(&client->dev);
1011         return 0;
1012
1013 err_mem_free:
1014         hid_destroy_device(hid);
1015
1016 err_irq:
1017         free_irq(client->irq, ihid);
1018
1019 err_pm:
1020         pm_runtime_put_noidle(&client->dev);
1021         pm_runtime_disable(&client->dev);
1022
1023 err:
1024         i2c_hid_free_buffers(ihid);
1025         kfree(ihid);
1026         return ret;
1027 }
1028
1029 static int i2c_hid_remove(struct i2c_client *client)
1030 {
1031         struct i2c_hid *ihid = i2c_get_clientdata(client);
1032         struct hid_device *hid;
1033
1034         pm_runtime_get_sync(&client->dev);
1035         pm_runtime_disable(&client->dev);
1036         pm_runtime_set_suspended(&client->dev);
1037         pm_runtime_put_noidle(&client->dev);
1038
1039         hid = ihid->hid;
1040         hid_destroy_device(hid);
1041
1042         free_irq(client->irq, ihid);
1043
1044         if (ihid->bufsize)
1045                 i2c_hid_free_buffers(ihid);
1046
1047         kfree(ihid);
1048
1049         return 0;
1050 }
1051
1052 #ifdef CONFIG_PM_SLEEP
1053 static int i2c_hid_suspend(struct device *dev)
1054 {
1055         struct i2c_client *client = to_i2c_client(dev);
1056         struct i2c_hid *ihid = i2c_get_clientdata(client);
1057         struct hid_device *hid = ihid->hid;
1058         int ret = 0;
1059
1060         disable_irq(client->irq);
1061         if (device_may_wakeup(&client->dev))
1062                 enable_irq_wake(client->irq);
1063
1064         if (hid->driver && hid->driver->suspend)
1065                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1066
1067         /* Save some power */
1068         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1069
1070         return ret;
1071 }
1072
1073 static int i2c_hid_resume(struct device *dev)
1074 {
1075         int ret;
1076         struct i2c_client *client = to_i2c_client(dev);
1077         struct i2c_hid *ihid = i2c_get_clientdata(client);
1078         struct hid_device *hid = ihid->hid;
1079
1080         enable_irq(client->irq);
1081         ret = i2c_hid_hwreset(client);
1082         if (ret)
1083                 return ret;
1084
1085         if (device_may_wakeup(&client->dev))
1086                 disable_irq_wake(client->irq);
1087
1088         if (hid->driver && hid->driver->reset_resume) {
1089                 ret = hid->driver->reset_resume(hid);
1090                 return ret;
1091         }
1092
1093         return 0;
1094 }
1095 #endif
1096
1097 #ifdef CONFIG_PM
1098 static int i2c_hid_runtime_suspend(struct device *dev)
1099 {
1100         struct i2c_client *client = to_i2c_client(dev);
1101
1102         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1103         disable_irq(client->irq);
1104         return 0;
1105 }
1106
1107 static int i2c_hid_runtime_resume(struct device *dev)
1108 {
1109         struct i2c_client *client = to_i2c_client(dev);
1110
1111         enable_irq(client->irq);
1112         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1113         return 0;
1114 }
1115 #endif
1116
1117 static const struct dev_pm_ops i2c_hid_pm = {
1118         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1119         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1120                            NULL)
1121 };
1122
1123 static const struct i2c_device_id i2c_hid_id_table[] = {
1124         { "hid", 0 },
1125         { },
1126 };
1127 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1128
1129
1130 static struct i2c_driver i2c_hid_driver = {
1131         .driver = {
1132                 .name   = "i2c_hid",
1133                 .owner  = THIS_MODULE,
1134                 .pm     = &i2c_hid_pm,
1135                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1136                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1137         },
1138
1139         .probe          = i2c_hid_probe,
1140         .remove         = i2c_hid_remove,
1141
1142         .id_table       = i2c_hid_id_table,
1143 };
1144
1145 module_i2c_driver(i2c_hid_driver);
1146
1147 MODULE_DESCRIPTION("HID over I2C core driver");
1148 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1149 MODULE_LICENSE("GPL");