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/irq.h>
  26 #include <linux/delay.h>
  27 #include <linux/slab.h>
  28 #include <linux/pm.h>
  29 #include <linux/pm_runtime.h>
  30 #include <linux/device.h>
  31 #include <linux/wait.h>
  32 #include <linux/err.h>
  33 #include <linux/string.h>
  34 #include <linux/list.h>
  35 #include <linux/jiffies.h>
  36 #include <linux/kernel.h>
  37 #include <linux/hid.h>
  38 #include <linux/mutex.h>
  39 #include <linux/acpi.h>
  40 #include <linux/of.h>
  41 #include <linux/regulator/consumer.h>
  42
  43 #include <linux/i2c/i2c-hid.h>
  44
  45 #include "../hid-ids.h"
  46
  47 /* quirks to control the device */
  48 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV        BIT(0)
  49
  50 /* flags */
  51 #define I2C_HID_STARTED         0
  52 #define I2C_HID_RESET_PENDING   1
  53 #define I2C_HID_READ_PENDING    2
  54
  55 #define I2C_HID_PWR_ON          0x00
  56 #define I2C_HID_PWR_SLEEP       0x01
  57
  58 /* debug option */
  59 static bool debug;
  60 module_param(debug, bool, 0444);
  61 MODULE_PARM_DESC(debug, "print a lot of debug information");
  62
  63 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  64 do {                                                                      \
  65         if (debug)                                                        \
  66                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  67 } while (0)
  68
  69 struct i2c_hid_desc {
  70         __le16 wHIDDescLength;
  71         __le16 bcdVersion;
  72         __le16 wReportDescLength;
  73         __le16 wReportDescRegister;
  74         __le16 wInputRegister;
  75         __le16 wMaxInputLength;
  76         __le16 wOutputRegister;
  77         __le16 wMaxOutputLength;
  78         __le16 wCommandRegister;
  79         __le16 wDataRegister;
  80         __le16 wVendorID;
  81         __le16 wProductID;
  82         __le16 wVersionID;
  83         __le32 reserved;
  84 } __packed;
  85
  86 struct i2c_hid_cmd {
  87         unsigned int registerIndex;
  88         __u8 opcode;
  89         unsigned int length;
  90         bool wait;
  91 };
  92
  93 union command {
  94         u8 data[0];
  95         struct cmd {
  96                 __le16 reg;
  97                 __u8 reportTypeID;
  98                 __u8 opcode;
  99         } __packed c;
 100 };
 101
 102 #define I2C_HID_CMD(opcode_) \
 103         .opcode = opcode_, .length = 4, \
 104         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 105
 106 /* fetch HID descriptor */
 107 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 108 /* fetch report descriptors */
 109 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 110                 .registerIndex = offsetof(struct i2c_hid_desc,
 111                         wReportDescRegister),
 112                 .opcode = 0x00,
 113                 .length = 2 };
 114 /* commands */
 115 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 116                                                           .wait = true };
 117 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 118 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 119 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 120 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 121
 122 /*
 123  * These definitions are not used here, but are defined by the spec.
 124  * Keeping them here for documentation purposes.
 125  *
 126  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 127  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 128  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 129  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 130  */
 131
 132 static DEFINE_MUTEX(i2c_hid_open_mut);
 133
 134 /* The main device structure */
 135 struct i2c_hid {
 136         struct i2c_client       *client;        /* i2c client */
 137         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 138         union {
 139                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 140                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 141         };
 142         __le16                  wHIDDescRegister; /* location of the i2c
 143                                                    * register of the HID
 144                                                    * descriptor. */
 145         unsigned int            bufsize;        /* i2c buffer size */
 146         char                    *inbuf;         /* Input buffer */
 147         char                    *rawbuf;        /* Raw Input buffer */
 148         char                    *cmdbuf;        /* Command buffer */
 149         char                    *argsbuf;       /* Command arguments buffer */
 150
 151         unsigned long           flags;          /* device flags */
 152         unsigned long           quirks;         /* Various quirks */
 153
 154         wait_queue_head_t       wait;           /* For waiting the interrupt */
 155
 156         struct i2c_hid_platform_data pdata;
 157
 158         bool                    irq_wake_enabled;
 159         struct mutex            reset_lock;
 160 };
 161
 162 static const struct i2c_hid_quirks {
 163         __u16 idVendor;
 164         __u16 idProduct;
 165         __u32 quirks;
 166 } i2c_hid_quirks[] = {
 167         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
 168                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 169         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
 170                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 171         { 0, 0 }
 172 };
 173
 174 /*
 175  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 176  * @idVendor: the 16-bit vendor ID
 177  * @idProduct: the 16-bit product ID
 178  *
 179  * Returns: a u32 quirks value.
 180  */
 181 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 182 {
 183         u32 quirks = 0;
 184         int n;
 185
 186         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 187                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 188                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 189                      i2c_hid_quirks[n].idProduct == idProduct))
 190                         quirks = i2c_hid_quirks[n].quirks;
 191
 192         return quirks;
 193 }
 194
 195 static int __i2c_hid_command(struct i2c_client *client,
 196                 const struct i2c_hid_cmd *command, u8 reportID,
 197                 u8 reportType, u8 *args, int args_len,
 198                 unsigned char *buf_recv, int data_len)
 199 {
 200         struct i2c_hid *ihid = i2c_get_clientdata(client);
 201         union command *cmd = (union command *)ihid->cmdbuf;
 202         int ret;
 203         struct i2c_msg msg[2];
 204         int msg_num = 1;
 205
 206         int length = command->length;
 207         bool wait = command->wait;
 208         unsigned int registerIndex = command->registerIndex;
 209
 210         /* special case for hid_descr_cmd */
 211         if (command == &hid_descr_cmd) {
 212                 cmd->c.reg = ihid->wHIDDescRegister;
 213         } else {
 214                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 215                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 216         }
 217
 218         if (length > 2) {
 219                 cmd->c.opcode = command->opcode;
 220                 cmd->c.reportTypeID = reportID | reportType << 4;
 221         }
 222
 223         memcpy(cmd->data + length, args, args_len);
 224         length += args_len;
 225
 226         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 227
 228         msg[0].addr = client->addr;
 229         msg[0].flags = client->flags & I2C_M_TEN;
 230         msg[0].len = length;
 231         msg[0].buf = cmd->data;
 232         if (data_len > 0) {
 233                 msg[1].addr = client->addr;
 234                 msg[1].flags = client->flags & I2C_M_TEN;
 235                 msg[1].flags |= I2C_M_RD;
 236                 msg[1].len = data_len;
 237                 msg[1].buf = buf_recv;
 238                 msg_num = 2;
 239                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 240         }
 241
 242         if (wait)
 243                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 244
 245         ret = i2c_transfer(client->adapter, msg, msg_num);
 246
 247         if (data_len > 0)
 248                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 249
 250         if (ret != msg_num)
 251                 return ret < 0 ? ret : -EIO;
 252
 253         ret = 0;
 254
 255         if (wait) {
 256                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 257                 if (!wait_event_timeout(ihid->wait,
 258                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 259                                 msecs_to_jiffies(5000)))
 260                         ret = -ENODATA;
 261                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 262         }
 263
 264         return ret;
 265 }
 266
 267 static int i2c_hid_command(struct i2c_client *client,
 268                 const struct i2c_hid_cmd *command,
 269                 unsigned char *buf_recv, int data_len)
 270 {
 271         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 272                                 buf_recv, data_len);
 273 }
 274
 275 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 276                 u8 reportID, unsigned char *buf_recv, int data_len)
 277 {
 278         struct i2c_hid *ihid = i2c_get_clientdata(client);
 279         u8 args[3];
 280         int ret;
 281         int args_len = 0;
 282         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 283
 284         i2c_hid_dbg(ihid, "%s\n", __func__);
 285
 286         if (reportID >= 0x0F) {
 287                 args[args_len++] = reportID;
 288                 reportID = 0x0F;
 289         }
 290
 291         args[args_len++] = readRegister & 0xFF;
 292         args[args_len++] = readRegister >> 8;
 293
 294         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 295                 reportType, args, args_len, buf_recv, data_len);
 296         if (ret) {
 297                 dev_err(&client->dev,
 298                         "failed to retrieve report from device.\n");
 299                 return ret;
 300         }
 301
 302         return 0;
 303 }
 304
 305 /**
 306  * i2c_hid_set_or_send_report: forward an incoming report to the device
 307  * @client: the i2c_client of the device
 308  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 309  * @reportID: the report ID
 310  * @buf: the actual data to transfer, without the report ID
 311  * @len: size of buf
 312  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 313  */
 314 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 315                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 316 {
 317         struct i2c_hid *ihid = i2c_get_clientdata(client);
 318         u8 *args = ihid->argsbuf;
 319         const struct i2c_hid_cmd *hidcmd;
 320         int ret;
 321         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 322         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 323         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 324         u16 size;
 325         int args_len;
 326         int index = 0;
 327
 328         i2c_hid_dbg(ihid, "%s\n", __func__);
 329
 330         if (data_len > ihid->bufsize)
 331                 return -EINVAL;
 332
 333         size =          2                       /* size */ +
 334                         (reportID ? 1 : 0)      /* reportID */ +
 335                         data_len                /* buf */;
 336         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 337                         2                       /* dataRegister */ +
 338                         size                    /* args */;
 339
 340         if (!use_data && maxOutputLength == 0)
 341                 return -ENOSYS;
 342
 343         if (reportID >= 0x0F) {
 344                 args[index++] = reportID;
 345                 reportID = 0x0F;
 346         }
 347
 348         /*
 349          * use the data register for feature reports or if the device does not
 350          * support the output register
 351          */
 352         if (use_data) {
 353                 args[index++] = dataRegister & 0xFF;
 354                 args[index++] = dataRegister >> 8;
 355                 hidcmd = &hid_set_report_cmd;
 356         } else {
 357                 args[index++] = outputRegister & 0xFF;
 358                 args[index++] = outputRegister >> 8;
 359                 hidcmd = &hid_no_cmd;
 360         }
 361
 362         args[index++] = size & 0xFF;
 363         args[index++] = size >> 8;
 364
 365         if (reportID)
 366                 args[index++] = reportID;
 367
 368         memcpy(&args[index], buf, data_len);
 369
 370         ret = __i2c_hid_command(client, hidcmd, reportID,
 371                 reportType, args, args_len, NULL, 0);
 372         if (ret) {
 373                 dev_err(&client->dev, "failed to set a report to device.\n");
 374                 return ret;
 375         }
 376
 377         return data_len;
 378 }
 379
 380 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 381 {
 382         struct i2c_hid *ihid = i2c_get_clientdata(client);
 383         int ret;
 384
 385         i2c_hid_dbg(ihid, "%s\n", __func__);
 386
 387         /*
 388          * Some devices require to send a command to wakeup before power on.
 389          * The call will get a return value (EREMOTEIO) but device will be
 390          * triggered and activated. After that, it goes like a normal device.
 391          */
 392         if (power_state == I2C_HID_PWR_ON &&
 393             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 394                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
 395
 396                 /* Device was already activated */
 397                 if (!ret)
 398                         goto set_pwr_exit;
 399         }
 400
 401         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 402                 0, NULL, 0, NULL, 0);
 403
 404         if (ret)
 405                 dev_err(&client->dev, "failed to change power setting.\n");
 406
 407 set_pwr_exit:
 408         return ret;
 409 }
 410
 411 static int i2c_hid_hwreset(struct i2c_client *client)
 412 {
 413         struct i2c_hid *ihid = i2c_get_clientdata(client);
 414         int ret;
 415
 416         i2c_hid_dbg(ihid, "%s\n", __func__);
 417
 418         /*
 419          * This prevents sending feature reports while the device is
 420          * being reset. Otherwise we may lose the reset complete
 421          * interrupt.
 422          */
 423         mutex_lock(&ihid->reset_lock);
 424
 425         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 426         if (ret)
 427                 goto out_unlock;
 428
 429         /*
 430          * The HID over I2C specification states that if a DEVICE needs time
 431          * after the PWR_ON request, it should utilise CLOCK stretching.
 432          * However, it has been observered that the Windows driver provides a
 433          * 1ms sleep between the PWR_ON and RESET requests and that some devices
 434          * rely on this.
 435          */
 436         usleep_range(1000, 5000);
 437
 438         i2c_hid_dbg(ihid, "resetting...\n");
 439
 440         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 441         if (ret) {
 442                 dev_err(&client->dev, "failed to reset device.\n");
 443                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 444         }
 445
 446 out_unlock:
 447         mutex_unlock(&ihid->reset_lock);
 448         return ret;
 449 }
 450
 451 static void i2c_hid_get_input(struct i2c_hid *ihid)
 452 {
 453         int ret, ret_size;
 454         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 455
 456         if (size > ihid->bufsize)
 457                 size = ihid->bufsize;
 458
 459         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 460         if (ret != size) {
 461                 if (ret < 0)
 462                         return;
 463
 464                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 465                         __func__, ret, size);
 466                 return;
 467         }
 468
 469         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 470
 471         if (!ret_size) {
 472                 /* host or device initiated RESET completed */
 473                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 474                         wake_up(&ihid->wait);
 475                 return;
 476         }
 477
 478         if (ret_size > size) {
 479                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 480                         __func__, size, ret_size);
 481                 return;
 482         }
 483
 484         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 485
 486         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 487                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 488                                 ret_size - 2, 1);
 489
 490         return;
 491 }
 492
 493 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 494 {
 495         struct i2c_hid *ihid = dev_id;
 496
 497         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 498                 return IRQ_HANDLED;
 499
 500         i2c_hid_get_input(ihid);
 501
 502         return IRQ_HANDLED;
 503 }
 504
 505 static int i2c_hid_get_report_length(struct hid_report *report)
 506 {
 507         return ((report->size - 1) >> 3) + 1 +
 508                 report->device->report_enum[report->type].numbered + 2;
 509 }
 510
 511 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 512         size_t bufsize)
 513 {
 514         struct hid_device *hid = report->device;
 515         struct i2c_client *client = hid->driver_data;
 516         struct i2c_hid *ihid = i2c_get_clientdata(client);
 517         unsigned int size, ret_size;
 518
 519         size = i2c_hid_get_report_length(report);
 520         if (i2c_hid_get_report(client,
 521                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 522                         report->id, buffer, size))
 523                 return;
 524
 525         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
 526
 527         ret_size = buffer[0] | (buffer[1] << 8);
 528
 529         if (ret_size != size) {
 530                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 531                         __func__, size, ret_size);
 532                 return;
 533         }
 534
 535         /* hid->driver_lock is held as we are in probe function,
 536          * we just need to setup the input fields, so using
 537          * hid_report_raw_event is safe. */
 538         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 539 }
 540
 541 /*
 542  * Initialize all reports
 543  */
 544 static void i2c_hid_init_reports(struct hid_device *hid)
 545 {
 546         struct hid_report *report;
 547         struct i2c_client *client = hid->driver_data;
 548         struct i2c_hid *ihid = i2c_get_clientdata(client);
 549         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 550
 551         if (!inbuf) {
 552                 dev_err(&client->dev, "can not retrieve initial reports\n");
 553                 return;
 554         }
 555
 556         /*
 557          * The device must be powered on while we fetch initial reports
 558          * from it.
 559          */
 560         pm_runtime_get_sync(&client->dev);
 561
 562         list_for_each_entry(report,
 563                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 564                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 565
 566         pm_runtime_put(&client->dev);
 567
 568         kfree(inbuf);
 569 }
 570
 571 /*
 572  * Traverse the supplied list of reports and find the longest
 573  */
 574 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 575                 unsigned int *max)
 576 {
 577         struct hid_report *report;
 578         unsigned int size;
 579
 580         /* We should not rely on wMaxInputLength, as some devices may set it to
 581          * a wrong length. */
 582         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 583                 size = i2c_hid_get_report_length(report);
 584                 if (*max < size)
 585                         *max = size;
 586         }
 587 }
 588
 589 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 590 {
 591         kfree(ihid->inbuf);
 592         kfree(ihid->rawbuf);
 593         kfree(ihid->argsbuf);
 594         kfree(ihid->cmdbuf);
 595         ihid->inbuf = NULL;
 596         ihid->rawbuf = NULL;
 597         ihid->cmdbuf = NULL;
 598         ihid->argsbuf = NULL;
 599         ihid->bufsize = 0;
 600 }
 601
 602 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 603 {
 604         /* the worst case is computed from the set_report command with a
 605          * reportID > 15 and the maximum report length */
 606         int args_len = sizeof(__u8) + /* optional ReportID byte */
 607                        sizeof(__u16) + /* data register */
 608                        sizeof(__u16) + /* size of the report */
 609                        report_size; /* report */
 610
 611         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 612         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 613         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 614         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 615
 616         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 617                 i2c_hid_free_buffers(ihid);
 618                 return -ENOMEM;
 619         }
 620
 621         ihid->bufsize = report_size;
 622
 623         return 0;
 624 }
 625
 626 static int i2c_hid_get_raw_report(struct hid_device *hid,
 627                 unsigned char report_number, __u8 *buf, size_t count,
 628                 unsigned char report_type)
 629 {
 630         struct i2c_client *client = hid->driver_data;
 631         struct i2c_hid *ihid = i2c_get_clientdata(client);
 632         size_t ret_count, ask_count;
 633         int ret;
 634
 635         if (report_type == HID_OUTPUT_REPORT)
 636                 return -EINVAL;
 637
 638         /* +2 bytes to include the size of the reply in the query buffer */
 639         ask_count = min(count + 2, (size_t)ihid->bufsize);
 640
 641         ret = i2c_hid_get_report(client,
 642                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 643                         report_number, ihid->rawbuf, ask_count);
 644
 645         if (ret < 0)
 646                 return ret;
 647
 648         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 649
 650         if (ret_count <= 2)
 651                 return 0;
 652
 653         ret_count = min(ret_count, ask_count);
 654
 655         /* The query buffer contains the size, dropping it in the reply */
 656         count = min(count, ret_count - 2);
 657         memcpy(buf, ihid->rawbuf + 2, count);
 658
 659         return count;
 660 }
 661
 662 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 663                 size_t count, unsigned char report_type, bool use_data)
 664 {
 665         struct i2c_client *client = hid->driver_data;
 666         struct i2c_hid *ihid = i2c_get_clientdata(client);
 667         int report_id = buf[0];
 668         int ret;
 669
 670         if (report_type == HID_INPUT_REPORT)
 671                 return -EINVAL;
 672
 673         mutex_lock(&ihid->reset_lock);
 674
 675         if (report_id) {
 676                 buf++;
 677                 count--;
 678         }
 679
 680         ret = i2c_hid_set_or_send_report(client,
 681                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 682                                 report_id, buf, count, use_data);
 683
 684         if (report_id && ret >= 0)
 685                 ret++; /* add report_id to the number of transfered bytes */
 686
 687         mutex_unlock(&ihid->reset_lock);
 688
 689         return ret;
 690 }
 691
 692 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 693                 size_t count)
 694 {
 695         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 696                         false);
 697 }
 698
 699 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 700                                __u8 *buf, size_t len, unsigned char rtype,
 701                                int reqtype)
 702 {
 703         switch (reqtype) {
 704         case HID_REQ_GET_REPORT:
 705                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 706         case HID_REQ_SET_REPORT:
 707                 if (buf[0] != reportnum)
 708                         return -EINVAL;
 709                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 710         default:
 711                 return -EIO;
 712         }
 713 }
 714
 715 static int i2c_hid_parse(struct hid_device *hid)
 716 {
 717         struct i2c_client *client = hid->driver_data;
 718         struct i2c_hid *ihid = i2c_get_clientdata(client);
 719         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 720         unsigned int rsize;
 721         char *rdesc;
 722         int ret;
 723         int tries = 3;
 724
 725         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 726
 727         rsize = le16_to_cpu(hdesc->wReportDescLength);
 728         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 729                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 730                 return -EINVAL;
 731         }
 732
 733         do {
 734                 ret = i2c_hid_hwreset(client);
 735                 if (ret)
 736                         msleep(1000);
 737         } while (tries-- > 0 && ret);
 738
 739         if (ret)
 740                 return ret;
 741
 742         rdesc = kzalloc(rsize, GFP_KERNEL);
 743
 744         if (!rdesc) {
 745                 dbg_hid("couldn't allocate rdesc memory\n");
 746                 return -ENOMEM;
 747         }
 748
 749         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 750
 751         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 752         if (ret) {
 753                 hid_err(hid, "reading report descriptor failed\n");
 754                 kfree(rdesc);
 755                 return -EIO;
 756         }
 757
 758         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 759
 760         ret = hid_parse_report(hid, rdesc, rsize);
 761         kfree(rdesc);
 762         if (ret) {
 763                 dbg_hid("parsing report descriptor failed\n");
 764                 return ret;
 765         }
 766
 767         return 0;
 768 }
 769
 770 static int i2c_hid_start(struct hid_device *hid)
 771 {
 772         struct i2c_client *client = hid->driver_data;
 773         struct i2c_hid *ihid = i2c_get_clientdata(client);
 774         int ret;
 775         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 776
 777         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 778         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 779         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 780
 781         if (bufsize > ihid->bufsize) {
 782                 disable_irq(client->irq);
 783                 i2c_hid_free_buffers(ihid);
 784
 785                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 786                 enable_irq(client->irq);
 787
 788                 if (ret)
 789                         return ret;
 790         }
 791
 792         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 793                 i2c_hid_init_reports(hid);
 794
 795         return 0;
 796 }
 797
 798 static void i2c_hid_stop(struct hid_device *hid)
 799 {
 800         hid->claimed = 0;
 801 }
 802
 803 static int i2c_hid_open(struct hid_device *hid)
 804 {
 805         struct i2c_client *client = hid->driver_data;
 806         struct i2c_hid *ihid = i2c_get_clientdata(client);
 807         int ret = 0;
 808
 809         mutex_lock(&i2c_hid_open_mut);
 810         if (!hid->open++) {
 811                 ret = pm_runtime_get_sync(&client->dev);
 812                 if (ret < 0) {
 813                         hid->open--;
 814                         goto done;
 815                 }
 816                 set_bit(I2C_HID_STARTED, &ihid->flags);
 817         }
 818 done:
 819         mutex_unlock(&i2c_hid_open_mut);
 820         return ret < 0 ? ret : 0;
 821 }
 822
 823 static void i2c_hid_close(struct hid_device *hid)
 824 {
 825         struct i2c_client *client = hid->driver_data;
 826         struct i2c_hid *ihid = i2c_get_clientdata(client);
 827
 828         /* protecting hid->open to make sure we don't restart
 829          * data acquistion due to a resumption we no longer
 830          * care about
 831          */
 832         mutex_lock(&i2c_hid_open_mut);
 833         if (!--hid->open) {
 834                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 835
 836                 /* Save some power */
 837                 pm_runtime_put(&client->dev);
 838         }
 839         mutex_unlock(&i2c_hid_open_mut);
 840 }
 841
 842 static int i2c_hid_power(struct hid_device *hid, int lvl)
 843 {
 844         struct i2c_client *client = hid->driver_data;
 845         struct i2c_hid *ihid = i2c_get_clientdata(client);
 846
 847         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 848
 849         switch (lvl) {
 850         case PM_HINT_FULLON:
 851                 pm_runtime_get_sync(&client->dev);
 852                 break;
 853         case PM_HINT_NORMAL:
 854                 pm_runtime_put(&client->dev);
 855                 break;
 856         }
 857         return 0;
 858 }
 859
 860 static struct hid_ll_driver i2c_hid_ll_driver = {
 861         .parse = i2c_hid_parse,
 862         .start = i2c_hid_start,
 863         .stop = i2c_hid_stop,
 864         .open = i2c_hid_open,
 865         .close = i2c_hid_close,
 866         .power = i2c_hid_power,
 867         .output_report = i2c_hid_output_report,
 868         .raw_request = i2c_hid_raw_request,
 869 };
 870
 871 static int i2c_hid_init_irq(struct i2c_client *client)
 872 {
 873         struct i2c_hid *ihid = i2c_get_clientdata(client);
 874         unsigned long irqflags = 0;
 875         int ret;
 876
 877         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 878
 879         if (!irq_get_trigger_type(client->irq))
 880                 irqflags = IRQF_TRIGGER_LOW;
 881
 882         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 883                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 884         if (ret < 0) {
 885                 dev_warn(&client->dev,
 886                         "Could not register for %s interrupt, irq = %d,"
 887                         " ret = %d\n",
 888                         client->name, client->irq, ret);
 889
 890                 return ret;
 891         }
 892
 893         return 0;
 894 }
 895
 896 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 897 {
 898         struct i2c_client *client = ihid->client;
 899         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 900         unsigned int dsize;
 901         int ret;
 902
 903         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 904         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 905         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 906                                 sizeof(struct i2c_hid_desc));
 907         if (ret) {
 908                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 909                 return -ENODEV;
 910         }
 911
 912         /* Validate the length of HID descriptor, the 4 first bytes:
 913          * bytes 0-1 -> length
 914          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 915         /* check bcdVersion == 1.0 */
 916         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 917                 dev_err(&client->dev,
 918                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 919                         le16_to_cpu(hdesc->bcdVersion));
 920                 return -ENODEV;
 921         }
 922
 923         /* Descriptor length should be 30 bytes as per the specification */
 924         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 925         if (dsize != sizeof(struct i2c_hid_desc)) {
 926                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 927                         dsize);
 928                 return -ENODEV;
 929         }
 930         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 931         return 0;
 932 }
 933
 934 #ifdef CONFIG_ACPI
 935 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 936                 struct i2c_hid_platform_data *pdata)
 937 {
 938         static u8 i2c_hid_guid[] = {
 939                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 940                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 941         };
 942         union acpi_object *obj;
 943         struct acpi_device *adev;
 944         acpi_handle handle;
 945
 946         handle = ACPI_HANDLE(&client->dev);
 947         if (!handle || acpi_bus_get_device(handle, &adev))
 948                 return -ENODEV;
 949
 950         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 951                                       ACPI_TYPE_INTEGER);
 952         if (!obj) {
 953                 dev_err(&client->dev, "device _DSM execution failed\n");
 954                 return -ENODEV;
 955         }
 956
 957         pdata->hid_descriptor_address = obj->integer.value;
 958         ACPI_FREE(obj);
 959
 960         return 0;
 961 }
 962
 963 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 964         {"ACPI0C50", 0 },
 965         {"PNP0C50", 0 },
 966         { },
 967 };
 968 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 969 #else
 970 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 971                 struct i2c_hid_platform_data *pdata)
 972 {
 973         return -ENODEV;
 974 }
 975 #endif
 976
 977 #ifdef CONFIG_OF
 978 static int i2c_hid_of_probe(struct i2c_client *client,
 979                 struct i2c_hid_platform_data *pdata)
 980 {
 981         struct device *dev = &client->dev;
 982         u32 val;
 983         int ret;
 984
 985         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 986         if (ret) {
 987                 dev_err(&client->dev, "HID register address not provided\n");
 988                 return -ENODEV;
 989         }
 990         if (val >> 16) {
 991                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 992                         val);
 993                 return -EINVAL;
 994         }
 995         pdata->hid_descriptor_address = val;
 996
 997         return 0;
 998 }
 999
1000 static const struct of_device_id i2c_hid_of_match[] = {
1001         { .compatible = "hid-over-i2c" },
1002         {},
1003 };
1004 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
1005 #else
1006 static inline int i2c_hid_of_probe(struct i2c_client *client,
1007                 struct i2c_hid_platform_data *pdata)
1008 {
1009         return -ENODEV;
1010 }
1011 #endif
1012
1013 static int i2c_hid_probe(struct i2c_client *client,
1014                          const struct i2c_device_id *dev_id)
1015 {
1016         int ret;
1017         struct i2c_hid *ihid;
1018         struct hid_device *hid;
1019         __u16 hidRegister;
1020         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
1021
1022         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1023
1024         if (!client->irq) {
1025                 dev_err(&client->dev,
1026                         "HID over i2c has not been provided an Int IRQ\n");
1027                 return -EINVAL;
1028         }
1029
1030         if (client->irq < 0) {
1031                 if (client->irq != -EPROBE_DEFER)
1032                         dev_err(&client->dev,
1033                                 "HID over i2c doesn't have a valid IRQ\n");
1034                 return client->irq;
1035         }
1036
1037         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
1038         if (!ihid)
1039                 return -ENOMEM;
1040
1041         if (client->dev.of_node) {
1042                 ret = i2c_hid_of_probe(client, &ihid->pdata);
1043                 if (ret)
1044                         goto err;
1045         } else if (!platform_data) {
1046                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
1047                 if (ret) {
1048                         dev_err(&client->dev,
1049                                 "HID register address not provided\n");
1050                         goto err;
1051                 }
1052         } else {
1053                 ihid->pdata = *platform_data;
1054         }
1055
1056         i2c_set_clientdata(client, ihid);
1057
1058         ihid->client = client;
1059
1060         hidRegister = ihid->pdata.hid_descriptor_address;
1061         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1062
1063         init_waitqueue_head(&ihid->wait);
1064         mutex_init(&ihid->reset_lock);
1065
1066         /* we need to allocate the command buffer without knowing the maximum
1067          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1068          * real computation later. */
1069         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1070         if (ret < 0)
1071                 goto err;
1072
1073         pm_runtime_get_noresume(&client->dev);
1074         pm_runtime_set_active(&client->dev);
1075         pm_runtime_enable(&client->dev);
1076         device_enable_async_suspend(&client->dev);
1077
1078         ret = i2c_hid_fetch_hid_descriptor(ihid);
1079         if (ret < 0)
1080                 goto err_pm;
1081
1082         ret = i2c_hid_init_irq(client);
1083         if (ret < 0)
1084                 goto err_pm;
1085
1086         hid = hid_allocate_device();
1087         if (IS_ERR(hid)) {
1088                 ret = PTR_ERR(hid);
1089                 goto err_irq;
1090         }
1091
1092         ihid->hid = hid;
1093
1094         hid->driver_data = client;
1095         hid->ll_driver = &i2c_hid_ll_driver;
1096         hid->dev.parent = &client->dev;
1097         hid->bus = BUS_I2C;
1098         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1099         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1100         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1101
1102         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1103                  client->name, hid->vendor, hid->product);
1104         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1105
1106         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1107
1108         ret = hid_add_device(hid);
1109         if (ret) {
1110                 if (ret != -ENODEV)
1111                         hid_err(client, "can't add hid device: %d\n", ret);
1112                 goto err_mem_free;
1113         }
1114
1115         pm_runtime_put(&client->dev);
1116         return 0;
1117
1118 err_mem_free:
1119         hid_destroy_device(hid);
1120
1121 err_irq:
1122         free_irq(client->irq, ihid);
1123
1124 err_pm:
1125         pm_runtime_put_noidle(&client->dev);
1126         pm_runtime_disable(&client->dev);
1127
1128 err:
1129         i2c_hid_free_buffers(ihid);
1130         kfree(ihid);
1131         return ret;
1132 }
1133
1134 static int i2c_hid_remove(struct i2c_client *client)
1135 {
1136         struct i2c_hid *ihid = i2c_get_clientdata(client);
1137         struct hid_device *hid;
1138
1139         pm_runtime_get_sync(&client->dev);
1140         pm_runtime_disable(&client->dev);
1141         pm_runtime_set_suspended(&client->dev);
1142         pm_runtime_put_noidle(&client->dev);
1143
1144         hid = ihid->hid;
1145         hid_destroy_device(hid);
1146
1147         free_irq(client->irq, ihid);
1148
1149         if (ihid->bufsize)
1150                 i2c_hid_free_buffers(ihid);
1151
1152         kfree(ihid);
1153
1154         return 0;
1155 }
1156
1157 static void i2c_hid_shutdown(struct i2c_client *client)
1158 {
1159         struct i2c_hid *ihid = i2c_get_clientdata(client);
1160
1161         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1162         free_irq(client->irq, ihid);
1163 }
1164
1165 #ifdef CONFIG_PM_SLEEP
1166 static int i2c_hid_suspend(struct device *dev)
1167 {
1168         struct i2c_client *client = to_i2c_client(dev);
1169         struct i2c_hid *ihid = i2c_get_clientdata(client);
1170         struct hid_device *hid = ihid->hid;
1171         int ret;
1172         int wake_status;
1173
1174         if (hid->driver && hid->driver->suspend) {
1175                 /*
1176                  * Wake up the device so that IO issues in
1177                  * HID driver's suspend code can succeed.
1178                  */
1179                 ret = pm_runtime_resume(dev);
1180                 if (ret < 0)
1181                         return ret;
1182
1183                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1184                 if (ret < 0)
1185                         return ret;
1186         }
1187
1188         if (!pm_runtime_suspended(dev)) {
1189                 /* Save some power */
1190                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1191
1192                 disable_irq(client->irq);
1193         }
1194
1195         if (device_may_wakeup(&client->dev)) {
1196                 wake_status = enable_irq_wake(client->irq);
1197                 if (!wake_status)
1198                         ihid->irq_wake_enabled = true;
1199                 else
1200                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1201                                 wake_status);
1202         }
1203
1204         return 0;
1205 }
1206
1207 static int i2c_hid_resume(struct device *dev)
1208 {
1209         int ret;
1210         struct i2c_client *client = to_i2c_client(dev);
1211         struct i2c_hid *ihid = i2c_get_clientdata(client);
1212         struct hid_device *hid = ihid->hid;
1213         int wake_status;
1214
1215         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1216                 wake_status = disable_irq_wake(client->irq);
1217                 if (!wake_status)
1218                         ihid->irq_wake_enabled = false;
1219                 else
1220                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1221                                 wake_status);
1222         }
1223
1224         /* We'll resume to full power */
1225         pm_runtime_disable(dev);
1226         pm_runtime_set_active(dev);
1227         pm_runtime_enable(dev);
1228
1229         enable_irq(client->irq);
1230         ret = i2c_hid_hwreset(client);
1231         if (ret)
1232                 return ret;
1233
1234         if (hid->driver && hid->driver->reset_resume) {
1235                 ret = hid->driver->reset_resume(hid);
1236                 return ret;
1237         }
1238
1239         return 0;
1240 }
1241 #endif
1242
1243 #ifdef CONFIG_PM
1244 static int i2c_hid_runtime_suspend(struct device *dev)
1245 {
1246         struct i2c_client *client = to_i2c_client(dev);
1247
1248         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1249         disable_irq(client->irq);
1250         return 0;
1251 }
1252
1253 static int i2c_hid_runtime_resume(struct device *dev)
1254 {
1255         struct i2c_client *client = to_i2c_client(dev);
1256
1257         enable_irq(client->irq);
1258         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1259         return 0;
1260 }
1261 #endif
1262
1263 static const struct dev_pm_ops i2c_hid_pm = {
1264         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1265         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1266                            NULL)
1267 };
1268
1269 static const struct i2c_device_id i2c_hid_id_table[] = {
1270         { "hid", 0 },
1271         { "hid-over-i2c", 0 },
1272         { },
1273 };
1274 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1275
1276
1277 static struct i2c_driver i2c_hid_driver = {
1278         .driver = {
1279                 .name   = "i2c_hid",
1280                 .pm     = &i2c_hid_pm,
1281                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1282                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1283         },
1284
1285         .probe          = i2c_hid_probe,
1286         .remove         = i2c_hid_remove,
1287         .shutdown       = i2c_hid_shutdown,
1288         .id_table       = i2c_hid_id_table,
1289 };
1290
1291 module_i2c_driver(i2c_hid_driver);
1292
1293 MODULE_DESCRIPTION("HID over I2C core driver");
1294 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1295 MODULE_LICENSE("GPL");