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 #include <linux/gpio/consumer.h>
  41
  42 #include <linux/i2c/i2c-hid.h>
  43
  44 /* flags */
  45 #define I2C_HID_STARTED         0
  46 #define I2C_HID_RESET_PENDING   1
  47 #define I2C_HID_READ_PENDING    2
  48
  49 #define I2C_HID_PWR_ON          0x00
  50 #define I2C_HID_PWR_SLEEP       0x01
  51
  52 /* debug option */
  53 static bool debug;
  54 module_param(debug, bool, 0444);
  55 MODULE_PARM_DESC(debug, "print a lot of debug information");
  56
  57 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  58 do {                                                                      \
  59         if (debug)                                                        \
  60                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  61 } while (0)
  62
  63 struct i2c_hid_desc {
  64         __le16 wHIDDescLength;
  65         __le16 bcdVersion;
  66         __le16 wReportDescLength;
  67         __le16 wReportDescRegister;
  68         __le16 wInputRegister;
  69         __le16 wMaxInputLength;
  70         __le16 wOutputRegister;
  71         __le16 wMaxOutputLength;
  72         __le16 wCommandRegister;
  73         __le16 wDataRegister;
  74         __le16 wVendorID;
  75         __le16 wProductID;
  76         __le16 wVersionID;
  77         __le32 reserved;
  78 } __packed;
  79
  80 struct i2c_hid_cmd {
  81         unsigned int registerIndex;
  82         __u8 opcode;
  83         unsigned int length;
  84         bool wait;
  85 };
  86
  87 union command {
  88         u8 data[0];
  89         struct cmd {
  90                 __le16 reg;
  91                 __u8 reportTypeID;
  92                 __u8 opcode;
  93         } __packed c;
  94 };
  95
  96 #define I2C_HID_CMD(opcode_) \
  97         .opcode = opcode_, .length = 4, \
  98         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
  99
 100 /* fetch HID descriptor */
 101 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 102 /* fetch report descriptors */
 103 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 104                 .registerIndex = offsetof(struct i2c_hid_desc,
 105                         wReportDescRegister),
 106                 .opcode = 0x00,
 107                 .length = 2 };
 108 /* commands */
 109 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 110                                                           .wait = true };
 111 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 112 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 113 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 114 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 115
 116 /*
 117  * These definitions are not used here, but are defined by the spec.
 118  * Keeping them here for documentation purposes.
 119  *
 120  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 121  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 122  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 123  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 124  */
 125
 126 static DEFINE_MUTEX(i2c_hid_open_mut);
 127
 128 /* The main device structure */
 129 struct i2c_hid {
 130         struct i2c_client       *client;        /* i2c client */
 131         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 132         union {
 133                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 134                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 135         };
 136         __le16                  wHIDDescRegister; /* location of the i2c
 137                                                    * register of the HID
 138                                                    * descriptor. */
 139         unsigned int            bufsize;        /* i2c buffer size */
 140         char                    *inbuf;         /* Input buffer */
 141         char                    *rawbuf;        /* Raw Input buffer */
 142         char                    *cmdbuf;        /* Command buffer */
 143         char                    *argsbuf;       /* Command arguments buffer */
 144
 145         unsigned long           flags;          /* device flags */
 146
 147         wait_queue_head_t       wait;           /* For waiting the interrupt */
 148         struct gpio_desc        *desc;
 149         int                     irq;
 150
 151         struct i2c_hid_platform_data pdata;
 152
 153         bool                    irq_wake_enabled;
 154         struct mutex            reset_lock;
 155 };
 156
 157 static int __i2c_hid_command(struct i2c_client *client,
 158                 const struct i2c_hid_cmd *command, u8 reportID,
 159                 u8 reportType, u8 *args, int args_len,
 160                 unsigned char *buf_recv, int data_len)
 161 {
 162         struct i2c_hid *ihid = i2c_get_clientdata(client);
 163         union command *cmd = (union command *)ihid->cmdbuf;
 164         int ret;
 165         struct i2c_msg msg[2];
 166         int msg_num = 1;
 167
 168         int length = command->length;
 169         bool wait = command->wait;
 170         unsigned int registerIndex = command->registerIndex;
 171
 172         /* special case for hid_descr_cmd */
 173         if (command == &hid_descr_cmd) {
 174                 cmd->c.reg = ihid->wHIDDescRegister;
 175         } else {
 176                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 177                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 178         }
 179
 180         if (length > 2) {
 181                 cmd->c.opcode = command->opcode;
 182                 cmd->c.reportTypeID = reportID | reportType << 4;
 183         }
 184
 185         memcpy(cmd->data + length, args, args_len);
 186         length += args_len;
 187
 188         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 189
 190         msg[0].addr = client->addr;
 191         msg[0].flags = client->flags & I2C_M_TEN;
 192         msg[0].len = length;
 193         msg[0].buf = cmd->data;
 194         if (data_len > 0) {
 195                 msg[1].addr = client->addr;
 196                 msg[1].flags = client->flags & I2C_M_TEN;
 197                 msg[1].flags |= I2C_M_RD;
 198                 msg[1].len = data_len;
 199                 msg[1].buf = buf_recv;
 200                 msg_num = 2;
 201                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 202         }
 203
 204         if (wait)
 205                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 206
 207         ret = i2c_transfer(client->adapter, msg, msg_num);
 208
 209         if (data_len > 0)
 210                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 211
 212         if (ret != msg_num)
 213                 return ret < 0 ? ret : -EIO;
 214
 215         ret = 0;
 216
 217         if (wait) {
 218                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 219                 if (!wait_event_timeout(ihid->wait,
 220                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 221                                 msecs_to_jiffies(5000)))
 222                         ret = -ENODATA;
 223                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 224         }
 225
 226         return ret;
 227 }
 228
 229 static int i2c_hid_command(struct i2c_client *client,
 230                 const struct i2c_hid_cmd *command,
 231                 unsigned char *buf_recv, int data_len)
 232 {
 233         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 234                                 buf_recv, data_len);
 235 }
 236
 237 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 238                 u8 reportID, unsigned char *buf_recv, int data_len)
 239 {
 240         struct i2c_hid *ihid = i2c_get_clientdata(client);
 241         u8 args[3];
 242         int ret;
 243         int args_len = 0;
 244         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 245
 246         i2c_hid_dbg(ihid, "%s\n", __func__);
 247
 248         if (reportID >= 0x0F) {
 249                 args[args_len++] = reportID;
 250                 reportID = 0x0F;
 251         }
 252
 253         args[args_len++] = readRegister & 0xFF;
 254         args[args_len++] = readRegister >> 8;
 255
 256         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 257                 reportType, args, args_len, buf_recv, data_len);
 258         if (ret) {
 259                 dev_err(&client->dev,
 260                         "failed to retrieve report from device.\n");
 261                 return ret;
 262         }
 263
 264         return 0;
 265 }
 266
 267 /**
 268  * i2c_hid_set_or_send_report: forward an incoming report to the device
 269  * @client: the i2c_client of the device
 270  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 271  * @reportID: the report ID
 272  * @buf: the actual data to transfer, without the report ID
 273  * @len: size of buf
 274  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 275  */
 276 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 277                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 278 {
 279         struct i2c_hid *ihid = i2c_get_clientdata(client);
 280         u8 *args = ihid->argsbuf;
 281         const struct i2c_hid_cmd *hidcmd;
 282         int ret;
 283         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 284         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 285         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 286         u16 size;
 287         int args_len;
 288         int index = 0;
 289
 290         i2c_hid_dbg(ihid, "%s\n", __func__);
 291
 292         if (data_len > ihid->bufsize)
 293                 return -EINVAL;
 294
 295         size =          2                       /* size */ +
 296                         (reportID ? 1 : 0)      /* reportID */ +
 297                         data_len                /* buf */;
 298         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 299                         2                       /* dataRegister */ +
 300                         size                    /* args */;
 301
 302         if (!use_data && maxOutputLength == 0)
 303                 return -ENOSYS;
 304
 305         if (reportID >= 0x0F) {
 306                 args[index++] = reportID;
 307                 reportID = 0x0F;
 308         }
 309
 310         /*
 311          * use the data register for feature reports or if the device does not
 312          * support the output register
 313          */
 314         if (use_data) {
 315                 args[index++] = dataRegister & 0xFF;
 316                 args[index++] = dataRegister >> 8;
 317                 hidcmd = &hid_set_report_cmd;
 318         } else {
 319                 args[index++] = outputRegister & 0xFF;
 320                 args[index++] = outputRegister >> 8;
 321                 hidcmd = &hid_no_cmd;
 322         }
 323
 324         args[index++] = size & 0xFF;
 325         args[index++] = size >> 8;
 326
 327         if (reportID)
 328                 args[index++] = reportID;
 329
 330         memcpy(&args[index], buf, data_len);
 331
 332         ret = __i2c_hid_command(client, hidcmd, reportID,
 333                 reportType, args, args_len, NULL, 0);
 334         if (ret) {
 335                 dev_err(&client->dev, "failed to set a report to device.\n");
 336                 return ret;
 337         }
 338
 339         return data_len;
 340 }
 341
 342 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 343 {
 344         struct i2c_hid *ihid = i2c_get_clientdata(client);
 345         int ret;
 346
 347         i2c_hid_dbg(ihid, "%s\n", __func__);
 348
 349         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 350                 0, NULL, 0, NULL, 0);
 351         if (ret)
 352                 dev_err(&client->dev, "failed to change power setting.\n");
 353
 354         return ret;
 355 }
 356
 357 static int i2c_hid_hwreset(struct i2c_client *client)
 358 {
 359         struct i2c_hid *ihid = i2c_get_clientdata(client);
 360         int ret;
 361
 362         i2c_hid_dbg(ihid, "%s\n", __func__);
 363
 364         /*
 365          * This prevents sending feature reports while the device is
 366          * being reset. Otherwise we may lose the reset complete
 367          * interrupt.
 368          */
 369         mutex_lock(&ihid->reset_lock);
 370
 371         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 372         if (ret)
 373                 goto out_unlock;
 374
 375         i2c_hid_dbg(ihid, "resetting...\n");
 376
 377         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 378         if (ret) {
 379                 dev_err(&client->dev, "failed to reset device.\n");
 380                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 381         }
 382
 383 out_unlock:
 384         mutex_unlock(&ihid->reset_lock);
 385         return ret;
 386 }
 387
 388 static void i2c_hid_get_input(struct i2c_hid *ihid)
 389 {
 390         int ret, ret_size;
 391         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 392
 393         if (size > ihid->bufsize)
 394                 size = ihid->bufsize;
 395
 396         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 397         if (ret != size) {
 398                 if (ret < 0)
 399                         return;
 400
 401                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 402                         __func__, ret, size);
 403                 return;
 404         }
 405
 406         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 407
 408         if (!ret_size) {
 409                 /* host or device initiated RESET completed */
 410                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 411                         wake_up(&ihid->wait);
 412                 return;
 413         }
 414
 415         if (ret_size > size) {
 416                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 417                         __func__, size, ret_size);
 418                 return;
 419         }
 420
 421         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 422
 423         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 424                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 425                                 ret_size - 2, 1);
 426
 427         return;
 428 }
 429
 430 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 431 {
 432         struct i2c_hid *ihid = dev_id;
 433
 434         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 435                 return IRQ_HANDLED;
 436
 437         i2c_hid_get_input(ihid);
 438
 439         return IRQ_HANDLED;
 440 }
 441
 442 static int i2c_hid_get_report_length(struct hid_report *report)
 443 {
 444         return ((report->size - 1) >> 3) + 1 +
 445                 report->device->report_enum[report->type].numbered + 2;
 446 }
 447
 448 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 449         size_t bufsize)
 450 {
 451         struct hid_device *hid = report->device;
 452         struct i2c_client *client = hid->driver_data;
 453         struct i2c_hid *ihid = i2c_get_clientdata(client);
 454         unsigned int size, ret_size;
 455
 456         size = i2c_hid_get_report_length(report);
 457         if (i2c_hid_get_report(client,
 458                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 459                         report->id, buffer, size))
 460                 return;
 461
 462         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
 463
 464         ret_size = buffer[0] | (buffer[1] << 8);
 465
 466         if (ret_size != size) {
 467                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 468                         __func__, size, ret_size);
 469                 return;
 470         }
 471
 472         /* hid->driver_lock is held as we are in probe function,
 473          * we just need to setup the input fields, so using
 474          * hid_report_raw_event is safe. */
 475         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 476 }
 477
 478 /*
 479  * Initialize all reports
 480  */
 481 static void i2c_hid_init_reports(struct hid_device *hid)
 482 {
 483         struct hid_report *report;
 484         struct i2c_client *client = hid->driver_data;
 485         struct i2c_hid *ihid = i2c_get_clientdata(client);
 486         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 487
 488         if (!inbuf) {
 489                 dev_err(&client->dev, "can not retrieve initial reports\n");
 490                 return;
 491         }
 492
 493         /*
 494          * The device must be powered on while we fetch initial reports
 495          * from it.
 496          */
 497         pm_runtime_get_sync(&client->dev);
 498
 499         list_for_each_entry(report,
 500                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 501                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 502
 503         pm_runtime_put(&client->dev);
 504
 505         kfree(inbuf);
 506 }
 507
 508 /*
 509  * Traverse the supplied list of reports and find the longest
 510  */
 511 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 512                 unsigned int *max)
 513 {
 514         struct hid_report *report;
 515         unsigned int size;
 516
 517         /* We should not rely on wMaxInputLength, as some devices may set it to
 518          * a wrong length. */
 519         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 520                 size = i2c_hid_get_report_length(report);
 521                 if (*max < size)
 522                         *max = size;
 523         }
 524 }
 525
 526 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 527 {
 528         kfree(ihid->inbuf);
 529         kfree(ihid->rawbuf);
 530         kfree(ihid->argsbuf);
 531         kfree(ihid->cmdbuf);
 532         ihid->inbuf = NULL;
 533         ihid->rawbuf = NULL;
 534         ihid->cmdbuf = NULL;
 535         ihid->argsbuf = NULL;
 536         ihid->bufsize = 0;
 537 }
 538
 539 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 540 {
 541         /* the worst case is computed from the set_report command with a
 542          * reportID > 15 and the maximum report length */
 543         int args_len = sizeof(__u8) + /* optional ReportID byte */
 544                        sizeof(__u16) + /* data register */
 545                        sizeof(__u16) + /* size of the report */
 546                        report_size; /* report */
 547
 548         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 549         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 550         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 551         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 552
 553         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 554                 i2c_hid_free_buffers(ihid);
 555                 return -ENOMEM;
 556         }
 557
 558         ihid->bufsize = report_size;
 559
 560         return 0;
 561 }
 562
 563 static int i2c_hid_get_raw_report(struct hid_device *hid,
 564                 unsigned char report_number, __u8 *buf, size_t count,
 565                 unsigned char report_type)
 566 {
 567         struct i2c_client *client = hid->driver_data;
 568         struct i2c_hid *ihid = i2c_get_clientdata(client);
 569         size_t ret_count, ask_count;
 570         int ret;
 571
 572         if (report_type == HID_OUTPUT_REPORT)
 573                 return -EINVAL;
 574
 575         /* +2 bytes to include the size of the reply in the query buffer */
 576         ask_count = min(count + 2, (size_t)ihid->bufsize);
 577
 578         ret = i2c_hid_get_report(client,
 579                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 580                         report_number, ihid->rawbuf, ask_count);
 581
 582         if (ret < 0)
 583                 return ret;
 584
 585         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 586
 587         if (ret_count <= 2)
 588                 return 0;
 589
 590         ret_count = min(ret_count, ask_count);
 591
 592         /* The query buffer contains the size, dropping it in the reply */
 593         count = min(count, ret_count - 2);
 594         memcpy(buf, ihid->rawbuf + 2, count);
 595
 596         return count;
 597 }
 598
 599 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 600                 size_t count, unsigned char report_type, bool use_data)
 601 {
 602         struct i2c_client *client = hid->driver_data;
 603         struct i2c_hid *ihid = i2c_get_clientdata(client);
 604         int report_id = buf[0];
 605         int ret;
 606
 607         if (report_type == HID_INPUT_REPORT)
 608                 return -EINVAL;
 609
 610         mutex_lock(&ihid->reset_lock);
 611
 612         if (report_id) {
 613                 buf++;
 614                 count--;
 615         }
 616
 617         ret = i2c_hid_set_or_send_report(client,
 618                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 619                                 report_id, buf, count, use_data);
 620
 621         if (report_id && ret >= 0)
 622                 ret++; /* add report_id to the number of transfered bytes */
 623
 624         mutex_unlock(&ihid->reset_lock);
 625
 626         return ret;
 627 }
 628
 629 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 630                 size_t count)
 631 {
 632         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 633                         false);
 634 }
 635
 636 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 637                                __u8 *buf, size_t len, unsigned char rtype,
 638                                int reqtype)
 639 {
 640         switch (reqtype) {
 641         case HID_REQ_GET_REPORT:
 642                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 643         case HID_REQ_SET_REPORT:
 644                 if (buf[0] != reportnum)
 645                         return -EINVAL;
 646                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 647         default:
 648                 return -EIO;
 649         }
 650 }
 651
 652 static int i2c_hid_parse(struct hid_device *hid)
 653 {
 654         struct i2c_client *client = hid->driver_data;
 655         struct i2c_hid *ihid = i2c_get_clientdata(client);
 656         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 657         unsigned int rsize;
 658         char *rdesc;
 659         int ret;
 660         int tries = 3;
 661
 662         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 663
 664         rsize = le16_to_cpu(hdesc->wReportDescLength);
 665         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 666                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 667                 return -EINVAL;
 668         }
 669
 670         do {
 671                 ret = i2c_hid_hwreset(client);
 672                 if (ret)
 673                         msleep(1000);
 674         } while (tries-- > 0 && ret);
 675
 676         if (ret)
 677                 return ret;
 678
 679         rdesc = kzalloc(rsize, GFP_KERNEL);
 680
 681         if (!rdesc) {
 682                 dbg_hid("couldn't allocate rdesc memory\n");
 683                 return -ENOMEM;
 684         }
 685
 686         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 687
 688         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 689         if (ret) {
 690                 hid_err(hid, "reading report descriptor failed\n");
 691                 kfree(rdesc);
 692                 return -EIO;
 693         }
 694
 695         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 696
 697         ret = hid_parse_report(hid, rdesc, rsize);
 698         kfree(rdesc);
 699         if (ret) {
 700                 dbg_hid("parsing report descriptor failed\n");
 701                 return ret;
 702         }
 703
 704         return 0;
 705 }
 706
 707 static int i2c_hid_start(struct hid_device *hid)
 708 {
 709         struct i2c_client *client = hid->driver_data;
 710         struct i2c_hid *ihid = i2c_get_clientdata(client);
 711         int ret;
 712         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 713
 714         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 715         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 716         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 717
 718         if (bufsize > ihid->bufsize) {
 719                 i2c_hid_free_buffers(ihid);
 720
 721                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 722
 723                 if (ret)
 724                         return ret;
 725         }
 726
 727         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 728                 i2c_hid_init_reports(hid);
 729
 730         return 0;
 731 }
 732
 733 static void i2c_hid_stop(struct hid_device *hid)
 734 {
 735         hid->claimed = 0;
 736 }
 737
 738 static int i2c_hid_open(struct hid_device *hid)
 739 {
 740         struct i2c_client *client = hid->driver_data;
 741         struct i2c_hid *ihid = i2c_get_clientdata(client);
 742         int ret = 0;
 743
 744         mutex_lock(&i2c_hid_open_mut);
 745         if (!hid->open++) {
 746                 ret = pm_runtime_get_sync(&client->dev);
 747                 if (ret < 0) {
 748                         hid->open--;
 749                         goto done;
 750                 }
 751                 set_bit(I2C_HID_STARTED, &ihid->flags);
 752         }
 753 done:
 754         mutex_unlock(&i2c_hid_open_mut);
 755         return ret < 0 ? ret : 0;
 756 }
 757
 758 static void i2c_hid_close(struct hid_device *hid)
 759 {
 760         struct i2c_client *client = hid->driver_data;
 761         struct i2c_hid *ihid = i2c_get_clientdata(client);
 762
 763         /* protecting hid->open to make sure we don't restart
 764          * data acquistion due to a resumption we no longer
 765          * care about
 766          */
 767         mutex_lock(&i2c_hid_open_mut);
 768         if (!--hid->open) {
 769                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 770
 771                 /* Save some power */
 772                 pm_runtime_put(&client->dev);
 773         }
 774         mutex_unlock(&i2c_hid_open_mut);
 775 }
 776
 777 static int i2c_hid_power(struct hid_device *hid, int lvl)
 778 {
 779         struct i2c_client *client = hid->driver_data;
 780         struct i2c_hid *ihid = i2c_get_clientdata(client);
 781
 782         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 783
 784         switch (lvl) {
 785         case PM_HINT_FULLON:
 786                 pm_runtime_get_sync(&client->dev);
 787                 break;
 788         case PM_HINT_NORMAL:
 789                 pm_runtime_put(&client->dev);
 790                 break;
 791         }
 792         return 0;
 793 }
 794
 795 static struct hid_ll_driver i2c_hid_ll_driver = {
 796         .parse = i2c_hid_parse,
 797         .start = i2c_hid_start,
 798         .stop = i2c_hid_stop,
 799         .open = i2c_hid_open,
 800         .close = i2c_hid_close,
 801         .power = i2c_hid_power,
 802         .output_report = i2c_hid_output_report,
 803         .raw_request = i2c_hid_raw_request,
 804 };
 805
 806 static int i2c_hid_init_irq(struct i2c_client *client)
 807 {
 808         struct i2c_hid *ihid = i2c_get_clientdata(client);
 809         int ret;
 810
 811         dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
 812
 813         ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
 814                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 815                         client->name, ihid);
 816         if (ret < 0) {
 817                 dev_warn(&client->dev,
 818                         "Could not register for %s interrupt, irq = %d,"
 819                         " ret = %d\n",
 820                         client->name, ihid->irq, ret);
 821
 822                 return ret;
 823         }
 824
 825         return 0;
 826 }
 827
 828 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 829 {
 830         struct i2c_client *client = ihid->client;
 831         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 832         unsigned int dsize;
 833         int ret;
 834
 835         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 836         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 837         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 838                                 sizeof(struct i2c_hid_desc));
 839         if (ret) {
 840                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 841                 return -ENODEV;
 842         }
 843
 844         /* Validate the length of HID descriptor, the 4 first bytes:
 845          * bytes 0-1 -> length
 846          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 847         /* check bcdVersion == 1.0 */
 848         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 849                 dev_err(&client->dev,
 850                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 851                         le16_to_cpu(hdesc->bcdVersion));
 852                 return -ENODEV;
 853         }
 854
 855         /* Descriptor length should be 30 bytes as per the specification */
 856         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 857         if (dsize != sizeof(struct i2c_hid_desc)) {
 858                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 859                         dsize);
 860                 return -ENODEV;
 861         }
 862         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 863         return 0;
 864 }
 865
 866 #ifdef CONFIG_ACPI
 867
 868 /* Default GPIO mapping */
 869 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
 870 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
 871         { "gpios", &i2c_hid_irq_gpio, 1 },
 872         { },
 873 };
 874
 875 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 876                 struct i2c_hid_platform_data *pdata)
 877 {
 878         static u8 i2c_hid_guid[] = {
 879                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 880                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 881         };
 882         union acpi_object *obj;
 883         struct acpi_device *adev;
 884         acpi_handle handle;
 885         int ret;
 886
 887         handle = ACPI_HANDLE(&client->dev);
 888         if (!handle || acpi_bus_get_device(handle, &adev))
 889                 return -ENODEV;
 890
 891         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 892                                       ACPI_TYPE_INTEGER);
 893         if (!obj) {
 894                 dev_err(&client->dev, "device _DSM execution failed\n");
 895                 return -ENODEV;
 896         }
 897
 898         pdata->hid_descriptor_address = obj->integer.value;
 899         ACPI_FREE(obj);
 900
 901         /* GPIOs are optional */
 902         ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
 903         return ret < 0 && ret != -ENXIO ? ret : 0;
 904 }
 905
 906 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 907         {"ACPI0C50", 0 },
 908         {"PNP0C50", 0 },
 909         { },
 910 };
 911 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 912 #else
 913 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 914                 struct i2c_hid_platform_data *pdata)
 915 {
 916         return -ENODEV;
 917 }
 918 #endif
 919
 920 #ifdef CONFIG_OF
 921 static int i2c_hid_of_probe(struct i2c_client *client,
 922                 struct i2c_hid_platform_data *pdata)
 923 {
 924         struct device *dev = &client->dev;
 925         u32 val;
 926         int ret;
 927
 928         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 929         if (ret) {
 930                 dev_err(&client->dev, "HID register address not provided\n");
 931                 return -ENODEV;
 932         }
 933         if (val >> 16) {
 934                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 935                         val);
 936                 return -EINVAL;
 937         }
 938         pdata->hid_descriptor_address = val;
 939
 940         return 0;
 941 }
 942
 943 static const struct of_device_id i2c_hid_of_match[] = {
 944         { .compatible = "hid-over-i2c" },
 945         {},
 946 };
 947 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 948 #else
 949 static inline int i2c_hid_of_probe(struct i2c_client *client,
 950                 struct i2c_hid_platform_data *pdata)
 951 {
 952         return -ENODEV;
 953 }
 954 #endif
 955
 956 static int i2c_hid_probe(struct i2c_client *client,
 957                          const struct i2c_device_id *dev_id)
 958 {
 959         int ret;
 960         struct i2c_hid *ihid;
 961         struct hid_device *hid;
 962         __u16 hidRegister;
 963         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 964
 965         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 966
 967         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 968         if (!ihid)
 969                 return -ENOMEM;
 970
 971         if (client->dev.of_node) {
 972                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 973                 if (ret)
 974                         goto err;
 975         } else if (!platform_data) {
 976                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 977                 if (ret) {
 978                         dev_err(&client->dev,
 979                                 "HID register address not provided\n");
 980                         goto err;
 981                 }
 982         } else {
 983                 ihid->pdata = *platform_data;
 984         }
 985
 986         if (client->irq > 0) {
 987                 ihid->irq = client->irq;
 988         } else if (ACPI_COMPANION(&client->dev)) {
 989                 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
 990                 if (IS_ERR(ihid->desc)) {
 991                         dev_err(&client->dev, "Failed to get GPIO interrupt\n");
 992                         return PTR_ERR(ihid->desc);
 993                 }
 994
 995                 ihid->irq = gpiod_to_irq(ihid->desc);
 996                 if (ihid->irq < 0) {
 997                         gpiod_put(ihid->desc);
 998                         dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
 999                         return ihid->irq;
1000                 }
1001         }
1002
1003         i2c_set_clientdata(client, ihid);
1004
1005         ihid->client = client;
1006
1007         hidRegister = ihid->pdata.hid_descriptor_address;
1008         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1009
1010         init_waitqueue_head(&ihid->wait);
1011         mutex_init(&ihid->reset_lock);
1012
1013         /* we need to allocate the command buffer without knowing the maximum
1014          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1015          * real computation later. */
1016         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1017         if (ret < 0)
1018                 goto err;
1019
1020         pm_runtime_get_noresume(&client->dev);
1021         pm_runtime_set_active(&client->dev);
1022         pm_runtime_enable(&client->dev);
1023         device_enable_async_suspend(&client->dev);
1024
1025         ret = i2c_hid_fetch_hid_descriptor(ihid);
1026         if (ret < 0)
1027                 goto err_pm;
1028
1029         ret = i2c_hid_init_irq(client);
1030         if (ret < 0)
1031                 goto err_pm;
1032
1033         hid = hid_allocate_device();
1034         if (IS_ERR(hid)) {
1035                 ret = PTR_ERR(hid);
1036                 goto err_irq;
1037         }
1038
1039         ihid->hid = hid;
1040
1041         hid->driver_data = client;
1042         hid->ll_driver = &i2c_hid_ll_driver;
1043         hid->dev.parent = &client->dev;
1044         hid->bus = BUS_I2C;
1045         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1046         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1047         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1048
1049         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1050                  client->name, hid->vendor, hid->product);
1051         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1052
1053         ret = hid_add_device(hid);
1054         if (ret) {
1055                 if (ret != -ENODEV)
1056                         hid_err(client, "can't add hid device: %d\n", ret);
1057                 goto err_mem_free;
1058         }
1059
1060         pm_runtime_put(&client->dev);
1061         return 0;
1062
1063 err_mem_free:
1064         hid_destroy_device(hid);
1065
1066 err_irq:
1067         free_irq(ihid->irq, ihid);
1068
1069 err_pm:
1070         pm_runtime_put_noidle(&client->dev);
1071         pm_runtime_disable(&client->dev);
1072
1073 err:
1074         if (ihid->desc)
1075                 gpiod_put(ihid->desc);
1076
1077         i2c_hid_free_buffers(ihid);
1078         kfree(ihid);
1079         return ret;
1080 }
1081
1082 static int i2c_hid_remove(struct i2c_client *client)
1083 {
1084         struct i2c_hid *ihid = i2c_get_clientdata(client);
1085         struct hid_device *hid;
1086
1087         pm_runtime_get_sync(&client->dev);
1088         pm_runtime_disable(&client->dev);
1089         pm_runtime_set_suspended(&client->dev);
1090         pm_runtime_put_noidle(&client->dev);
1091
1092         hid = ihid->hid;
1093         hid_destroy_device(hid);
1094
1095         free_irq(ihid->irq, ihid);
1096
1097         if (ihid->bufsize)
1098                 i2c_hid_free_buffers(ihid);
1099
1100         if (ihid->desc)
1101                 gpiod_put(ihid->desc);
1102
1103         kfree(ihid);
1104
1105         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1106
1107         return 0;
1108 }
1109
1110 static void i2c_hid_shutdown(struct i2c_client *client)
1111 {
1112         struct i2c_hid *ihid = i2c_get_clientdata(client);
1113
1114         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1115         free_irq(client->irq, ihid);
1116 }
1117
1118 #ifdef CONFIG_PM_SLEEP
1119 static int i2c_hid_suspend(struct device *dev)
1120 {
1121         struct i2c_client *client = to_i2c_client(dev);
1122         struct i2c_hid *ihid = i2c_get_clientdata(client);
1123         struct hid_device *hid = ihid->hid;
1124         int ret;
1125         int wake_status;
1126
1127         if (hid->driver && hid->driver->suspend) {
1128                 /*
1129                  * Wake up the device so that IO issues in
1130                  * HID driver's suspend code can succeed.
1131                  */
1132                 ret = pm_runtime_resume(dev);
1133                 if (ret < 0)
1134                         return ret;
1135
1136                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1137                 if (ret < 0)
1138                         return ret;
1139         }
1140
1141         if (!pm_runtime_suspended(dev)) {
1142                 /* Save some power */
1143                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1144
1145                 disable_irq(ihid->irq);
1146         }
1147
1148         if (device_may_wakeup(&client->dev)) {
1149                 wake_status = enable_irq_wake(ihid->irq);
1150                 if (!wake_status)
1151                         ihid->irq_wake_enabled = true;
1152                 else
1153                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1154                                 wake_status);
1155         }
1156
1157         return 0;
1158 }
1159
1160 static int i2c_hid_resume(struct device *dev)
1161 {
1162         int ret;
1163         struct i2c_client *client = to_i2c_client(dev);
1164         struct i2c_hid *ihid = i2c_get_clientdata(client);
1165         struct hid_device *hid = ihid->hid;
1166         int wake_status;
1167
1168         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1169                 wake_status = disable_irq_wake(ihid->irq);
1170                 if (!wake_status)
1171                         ihid->irq_wake_enabled = false;
1172                 else
1173                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1174                                 wake_status);
1175         }
1176
1177         /* We'll resume to full power */
1178         pm_runtime_disable(dev);
1179         pm_runtime_set_active(dev);
1180         pm_runtime_enable(dev);
1181
1182         enable_irq(ihid->irq);
1183         ret = i2c_hid_hwreset(client);
1184         if (ret)
1185                 return ret;
1186
1187         if (hid->driver && hid->driver->reset_resume) {
1188                 ret = hid->driver->reset_resume(hid);
1189                 return ret;
1190         }
1191
1192         return 0;
1193 }
1194 #endif
1195
1196 #ifdef CONFIG_PM
1197 static int i2c_hid_runtime_suspend(struct device *dev)
1198 {
1199         struct i2c_client *client = to_i2c_client(dev);
1200         struct i2c_hid *ihid = i2c_get_clientdata(client);
1201
1202         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1203         disable_irq(ihid->irq);
1204         return 0;
1205 }
1206
1207 static int i2c_hid_runtime_resume(struct device *dev)
1208 {
1209         struct i2c_client *client = to_i2c_client(dev);
1210         struct i2c_hid *ihid = i2c_get_clientdata(client);
1211
1212         enable_irq(ihid->irq);
1213         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1214         return 0;
1215 }
1216 #endif
1217
1218 static const struct dev_pm_ops i2c_hid_pm = {
1219         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1220         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1221                            NULL)
1222 };
1223
1224 static const struct i2c_device_id i2c_hid_id_table[] = {
1225         { "hid", 0 },
1226         { "hid-over-i2c", 0 },
1227         { },
1228 };
1229 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1230
1231
1232 static struct i2c_driver i2c_hid_driver = {
1233         .driver = {
1234                 .name   = "i2c_hid",
1235                 .pm     = &i2c_hid_pm,
1236                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1237                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1238         },
1239
1240         .probe          = i2c_hid_probe,
1241         .remove         = i2c_hid_remove,
1242         .shutdown       = i2c_hid_shutdown,
1243         .id_table       = i2c_hid_id_table,
1244 };
1245
1246 module_i2c_driver(i2c_hid_driver);
1247
1248 MODULE_DESCRIPTION("HID over I2C core driver");
1249 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1250 MODULE_LICENSE("GPL");