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/platform_data/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 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET        BIT(1)
  50
  51 /* flags */
  52 #define I2C_HID_STARTED         0
  53 #define I2C_HID_RESET_PENDING   1
  54 #define I2C_HID_READ_PENDING    2
  55
  56 #define I2C_HID_PWR_ON          0x00
  57 #define I2C_HID_PWR_SLEEP       0x01
  58
  59 /* debug option */
  60 static bool debug;
  61 module_param(debug, bool, 0444);
  62 MODULE_PARM_DESC(debug, "print a lot of debug information");
  63
  64 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  65 do {                                                                      \
  66         if (debug)                                                        \
  67                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  68 } while (0)
  69
  70 struct i2c_hid_desc {
  71         __le16 wHIDDescLength;
  72         __le16 bcdVersion;
  73         __le16 wReportDescLength;
  74         __le16 wReportDescRegister;
  75         __le16 wInputRegister;
  76         __le16 wMaxInputLength;
  77         __le16 wOutputRegister;
  78         __le16 wMaxOutputLength;
  79         __le16 wCommandRegister;
  80         __le16 wDataRegister;
  81         __le16 wVendorID;
  82         __le16 wProductID;
  83         __le16 wVersionID;
  84         __le32 reserved;
  85 } __packed;
  86
  87 struct i2c_hid_cmd {
  88         unsigned int registerIndex;
  89         __u8 opcode;
  90         unsigned int length;
  91         bool wait;
  92 };
  93
  94 union command {
  95         u8 data[0];
  96         struct cmd {
  97                 __le16 reg;
  98                 __u8 reportTypeID;
  99                 __u8 opcode;
 100         } __packed c;
 101 };
 102
 103 #define I2C_HID_CMD(opcode_) \
 104         .opcode = opcode_, .length = 4, \
 105         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 106
 107 /* fetch HID descriptor */
 108 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 109 /* fetch report descriptors */
 110 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 111                 .registerIndex = offsetof(struct i2c_hid_desc,
 112                         wReportDescRegister),
 113                 .opcode = 0x00,
 114                 .length = 2 };
 115 /* commands */
 116 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 117                                                           .wait = true };
 118 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 119 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 120 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 121 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 122
 123 /*
 124  * These definitions are not used here, but are defined by the spec.
 125  * Keeping them here for documentation purposes.
 126  *
 127  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 128  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 129  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 130  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 131  */
 132
 133 static DEFINE_MUTEX(i2c_hid_open_mut);
 134
 135 /* The main device structure */
 136 struct i2c_hid {
 137         struct i2c_client       *client;        /* i2c client */
 138         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 139         union {
 140                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 141                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 142         };
 143         __le16                  wHIDDescRegister; /* location of the i2c
 144                                                    * register of the HID
 145                                                    * descriptor. */
 146         unsigned int            bufsize;        /* i2c buffer size */
 147         u8                      *inbuf;         /* Input buffer */
 148         u8                      *rawbuf;        /* Raw Input buffer */
 149         u8                      *cmdbuf;        /* Command buffer */
 150         u8                      *argsbuf;       /* Command arguments buffer */
 151
 152         unsigned long           flags;          /* device flags */
 153         unsigned long           quirks;         /* Various quirks */
 154
 155         wait_queue_head_t       wait;           /* For waiting the interrupt */
 156
 157         struct i2c_hid_platform_data pdata;
 158
 159         bool                    irq_wake_enabled;
 160         struct mutex            reset_lock;
 161 };
 162
 163 static const struct i2c_hid_quirks {
 164         __u16 idVendor;
 165         __u16 idProduct;
 166         __u32 quirks;
 167 } i2c_hid_quirks[] = {
 168         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
 169                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 170         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
 171                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 172         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 173                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 174         { 0, 0 }
 175 };
 176
 177 /*
 178  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 179  * @idVendor: the 16-bit vendor ID
 180  * @idProduct: the 16-bit product ID
 181  *
 182  * Returns: a u32 quirks value.
 183  */
 184 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 185 {
 186         u32 quirks = 0;
 187         int n;
 188
 189         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 190                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 191                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 192                      i2c_hid_quirks[n].idProduct == idProduct))
 193                         quirks = i2c_hid_quirks[n].quirks;
 194
 195         return quirks;
 196 }
 197
 198 static int __i2c_hid_command(struct i2c_client *client,
 199                 const struct i2c_hid_cmd *command, u8 reportID,
 200                 u8 reportType, u8 *args, int args_len,
 201                 unsigned char *buf_recv, int data_len)
 202 {
 203         struct i2c_hid *ihid = i2c_get_clientdata(client);
 204         union command *cmd = (union command *)ihid->cmdbuf;
 205         int ret;
 206         struct i2c_msg msg[2];
 207         int msg_num = 1;
 208
 209         int length = command->length;
 210         bool wait = command->wait;
 211         unsigned int registerIndex = command->registerIndex;
 212
 213         /* special case for hid_descr_cmd */
 214         if (command == &hid_descr_cmd) {
 215                 cmd->c.reg = ihid->wHIDDescRegister;
 216         } else {
 217                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 218                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 219         }
 220
 221         if (length > 2) {
 222                 cmd->c.opcode = command->opcode;
 223                 cmd->c.reportTypeID = reportID | reportType << 4;
 224         }
 225
 226         memcpy(cmd->data + length, args, args_len);
 227         length += args_len;
 228
 229         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 230
 231         msg[0].addr = client->addr;
 232         msg[0].flags = client->flags & I2C_M_TEN;
 233         msg[0].len = length;
 234         msg[0].buf = cmd->data;
 235         if (data_len > 0) {
 236                 msg[1].addr = client->addr;
 237                 msg[1].flags = client->flags & I2C_M_TEN;
 238                 msg[1].flags |= I2C_M_RD;
 239                 msg[1].len = data_len;
 240                 msg[1].buf = buf_recv;
 241                 msg_num = 2;
 242                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 243         }
 244
 245         if (wait)
 246                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 247
 248         ret = i2c_transfer(client->adapter, msg, msg_num);
 249
 250         if (data_len > 0)
 251                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 252
 253         if (ret != msg_num)
 254                 return ret < 0 ? ret : -EIO;
 255
 256         ret = 0;
 257
 258         if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
 259                 msleep(100);
 260         } else if (wait) {
 261                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 262                 if (!wait_event_timeout(ihid->wait,
 263                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 264                                 msecs_to_jiffies(5000)))
 265                         ret = -ENODATA;
 266                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 267         }
 268
 269         return ret;
 270 }
 271
 272 static int i2c_hid_command(struct i2c_client *client,
 273                 const struct i2c_hid_cmd *command,
 274                 unsigned char *buf_recv, int data_len)
 275 {
 276         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 277                                 buf_recv, data_len);
 278 }
 279
 280 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 281                 u8 reportID, unsigned char *buf_recv, int data_len)
 282 {
 283         struct i2c_hid *ihid = i2c_get_clientdata(client);
 284         u8 args[3];
 285         int ret;
 286         int args_len = 0;
 287         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 288
 289         i2c_hid_dbg(ihid, "%s\n", __func__);
 290
 291         if (reportID >= 0x0F) {
 292                 args[args_len++] = reportID;
 293                 reportID = 0x0F;
 294         }
 295
 296         args[args_len++] = readRegister & 0xFF;
 297         args[args_len++] = readRegister >> 8;
 298
 299         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 300                 reportType, args, args_len, buf_recv, data_len);
 301         if (ret) {
 302                 dev_err(&client->dev,
 303                         "failed to retrieve report from device.\n");
 304                 return ret;
 305         }
 306
 307         return 0;
 308 }
 309
 310 /**
 311  * i2c_hid_set_or_send_report: forward an incoming report to the device
 312  * @client: the i2c_client of the device
 313  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 314  * @reportID: the report ID
 315  * @buf: the actual data to transfer, without the report ID
 316  * @len: size of buf
 317  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 318  */
 319 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 320                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 321 {
 322         struct i2c_hid *ihid = i2c_get_clientdata(client);
 323         u8 *args = ihid->argsbuf;
 324         const struct i2c_hid_cmd *hidcmd;
 325         int ret;
 326         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 327         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 328         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 329         u16 size;
 330         int args_len;
 331         int index = 0;
 332
 333         i2c_hid_dbg(ihid, "%s\n", __func__);
 334
 335         if (data_len > ihid->bufsize)
 336                 return -EINVAL;
 337
 338         size =          2                       /* size */ +
 339                         (reportID ? 1 : 0)      /* reportID */ +
 340                         data_len                /* buf */;
 341         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 342                         2                       /* dataRegister */ +
 343                         size                    /* args */;
 344
 345         if (!use_data && maxOutputLength == 0)
 346                 return -ENOSYS;
 347
 348         if (reportID >= 0x0F) {
 349                 args[index++] = reportID;
 350                 reportID = 0x0F;
 351         }
 352
 353         /*
 354          * use the data register for feature reports or if the device does not
 355          * support the output register
 356          */
 357         if (use_data) {
 358                 args[index++] = dataRegister & 0xFF;
 359                 args[index++] = dataRegister >> 8;
 360                 hidcmd = &hid_set_report_cmd;
 361         } else {
 362                 args[index++] = outputRegister & 0xFF;
 363                 args[index++] = outputRegister >> 8;
 364                 hidcmd = &hid_no_cmd;
 365         }
 366
 367         args[index++] = size & 0xFF;
 368         args[index++] = size >> 8;
 369
 370         if (reportID)
 371                 args[index++] = reportID;
 372
 373         memcpy(&args[index], buf, data_len);
 374
 375         ret = __i2c_hid_command(client, hidcmd, reportID,
 376                 reportType, args, args_len, NULL, 0);
 377         if (ret) {
 378                 dev_err(&client->dev, "failed to set a report to device.\n");
 379                 return ret;
 380         }
 381
 382         return data_len;
 383 }
 384
 385 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 386 {
 387         struct i2c_hid *ihid = i2c_get_clientdata(client);
 388         int ret;
 389
 390         i2c_hid_dbg(ihid, "%s\n", __func__);
 391
 392         /*
 393          * Some devices require to send a command to wakeup before power on.
 394          * The call will get a return value (EREMOTEIO) but device will be
 395          * triggered and activated. After that, it goes like a normal device.
 396          */
 397         if (power_state == I2C_HID_PWR_ON &&
 398             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 399                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
 400
 401                 /* Device was already activated */
 402                 if (!ret)
 403                         goto set_pwr_exit;
 404         }
 405
 406         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 407                 0, NULL, 0, NULL, 0);
 408
 409         if (ret)
 410                 dev_err(&client->dev, "failed to change power setting.\n");
 411
 412 set_pwr_exit:
 413         return ret;
 414 }
 415
 416 static int i2c_hid_hwreset(struct i2c_client *client)
 417 {
 418         struct i2c_hid *ihid = i2c_get_clientdata(client);
 419         int ret;
 420
 421         i2c_hid_dbg(ihid, "%s\n", __func__);
 422
 423         /*
 424          * This prevents sending feature reports while the device is
 425          * being reset. Otherwise we may lose the reset complete
 426          * interrupt.
 427          */
 428         mutex_lock(&ihid->reset_lock);
 429
 430         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 431         if (ret)
 432                 goto out_unlock;
 433
 434         /*
 435          * The HID over I2C specification states that if a DEVICE needs time
 436          * after the PWR_ON request, it should utilise CLOCK stretching.
 437          * However, it has been observered that the Windows driver provides a
 438          * 1ms sleep between the PWR_ON and RESET requests and that some devices
 439          * rely on this.
 440          */
 441         usleep_range(1000, 5000);
 442
 443         i2c_hid_dbg(ihid, "resetting...\n");
 444
 445         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 446         if (ret) {
 447                 dev_err(&client->dev, "failed to reset device.\n");
 448                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 449         }
 450
 451 out_unlock:
 452         mutex_unlock(&ihid->reset_lock);
 453         return ret;
 454 }
 455
 456 static void i2c_hid_get_input(struct i2c_hid *ihid)
 457 {
 458         int ret;
 459         u32 ret_size;
 460         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 461
 462         if (size > ihid->bufsize)
 463                 size = ihid->bufsize;
 464
 465         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 466         if (ret != size) {
 467                 if (ret < 0)
 468                         return;
 469
 470                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 471                         __func__, ret, size);
 472                 return;
 473         }
 474
 475         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 476
 477         if (!ret_size) {
 478                 /* host or device initiated RESET completed */
 479                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 480                         wake_up(&ihid->wait);
 481                 return;
 482         }
 483
 484         if ((ret_size > size) || (ret_size <= 2)) {
 485                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 486                         __func__, size, ret_size);
 487                 return;
 488         }
 489
 490         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 491
 492         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 493                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 494                                 ret_size - 2, 1);
 495
 496         return;
 497 }
 498
 499 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 500 {
 501         struct i2c_hid *ihid = dev_id;
 502
 503         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 504                 return IRQ_HANDLED;
 505
 506         i2c_hid_get_input(ihid);
 507
 508         return IRQ_HANDLED;
 509 }
 510
 511 static int i2c_hid_get_report_length(struct hid_report *report)
 512 {
 513         return ((report->size - 1) >> 3) + 1 +
 514                 report->device->report_enum[report->type].numbered + 2;
 515 }
 516
 517 /*
 518  * Traverse the supplied list of reports and find the longest
 519  */
 520 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 521                 unsigned int *max)
 522 {
 523         struct hid_report *report;
 524         unsigned int size;
 525
 526         /* We should not rely on wMaxInputLength, as some devices may set it to
 527          * a wrong length. */
 528         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 529                 size = i2c_hid_get_report_length(report);
 530                 if (*max < size)
 531                         *max = size;
 532         }
 533 }
 534
 535 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 536 {
 537         kfree(ihid->inbuf);
 538         kfree(ihid->rawbuf);
 539         kfree(ihid->argsbuf);
 540         kfree(ihid->cmdbuf);
 541         ihid->inbuf = NULL;
 542         ihid->rawbuf = NULL;
 543         ihid->cmdbuf = NULL;
 544         ihid->argsbuf = NULL;
 545         ihid->bufsize = 0;
 546 }
 547
 548 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 549 {
 550         /* the worst case is computed from the set_report command with a
 551          * reportID > 15 and the maximum report length */
 552         int args_len = sizeof(__u8) + /* ReportID */
 553                        sizeof(__u8) + /* optional ReportID byte */
 554                        sizeof(__u16) + /* data register */
 555                        sizeof(__u16) + /* size of the report */
 556                        report_size; /* report */
 557
 558         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 559         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 560         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 561         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 562
 563         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 564                 i2c_hid_free_buffers(ihid);
 565                 return -ENOMEM;
 566         }
 567
 568         ihid->bufsize = report_size;
 569
 570         return 0;
 571 }
 572
 573 static int i2c_hid_get_raw_report(struct hid_device *hid,
 574                 unsigned char report_number, __u8 *buf, size_t count,
 575                 unsigned char report_type)
 576 {
 577         struct i2c_client *client = hid->driver_data;
 578         struct i2c_hid *ihid = i2c_get_clientdata(client);
 579         size_t ret_count, ask_count;
 580         int ret;
 581
 582         if (report_type == HID_OUTPUT_REPORT)
 583                 return -EINVAL;
 584
 585         /* +2 bytes to include the size of the reply in the query buffer */
 586         ask_count = min(count + 2, (size_t)ihid->bufsize);
 587
 588         ret = i2c_hid_get_report(client,
 589                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 590                         report_number, ihid->rawbuf, ask_count);
 591
 592         if (ret < 0)
 593                 return ret;
 594
 595         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 596
 597         if (ret_count <= 2)
 598                 return 0;
 599
 600         ret_count = min(ret_count, ask_count);
 601
 602         /* The query buffer contains the size, dropping it in the reply */
 603         count = min(count, ret_count - 2);
 604         memcpy(buf, ihid->rawbuf + 2, count);
 605
 606         return count;
 607 }
 608
 609 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 610                 size_t count, unsigned char report_type, bool use_data)
 611 {
 612         struct i2c_client *client = hid->driver_data;
 613         struct i2c_hid *ihid = i2c_get_clientdata(client);
 614         int report_id = buf[0];
 615         int ret;
 616
 617         if (report_type == HID_INPUT_REPORT)
 618                 return -EINVAL;
 619
 620         mutex_lock(&ihid->reset_lock);
 621
 622         if (report_id) {
 623                 buf++;
 624                 count--;
 625         }
 626
 627         ret = i2c_hid_set_or_send_report(client,
 628                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 629                                 report_id, buf, count, use_data);
 630
 631         if (report_id && ret >= 0)
 632                 ret++; /* add report_id to the number of transfered bytes */
 633
 634         mutex_unlock(&ihid->reset_lock);
 635
 636         return ret;
 637 }
 638
 639 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 640                 size_t count)
 641 {
 642         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 643                         false);
 644 }
 645
 646 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 647                                __u8 *buf, size_t len, unsigned char rtype,
 648                                int reqtype)
 649 {
 650         switch (reqtype) {
 651         case HID_REQ_GET_REPORT:
 652                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 653         case HID_REQ_SET_REPORT:
 654                 if (buf[0] != reportnum)
 655                         return -EINVAL;
 656                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 657         default:
 658                 return -EIO;
 659         }
 660 }
 661
 662 static int i2c_hid_parse(struct hid_device *hid)
 663 {
 664         struct i2c_client *client = hid->driver_data;
 665         struct i2c_hid *ihid = i2c_get_clientdata(client);
 666         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 667         unsigned int rsize;
 668         char *rdesc;
 669         int ret;
 670         int tries = 3;
 671
 672         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 673
 674         rsize = le16_to_cpu(hdesc->wReportDescLength);
 675         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 676                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 677                 return -EINVAL;
 678         }
 679
 680         do {
 681                 ret = i2c_hid_hwreset(client);
 682                 if (ret)
 683                         msleep(1000);
 684         } while (tries-- > 0 && ret);
 685
 686         if (ret)
 687                 return ret;
 688
 689         rdesc = kzalloc(rsize, GFP_KERNEL);
 690
 691         if (!rdesc) {
 692                 dbg_hid("couldn't allocate rdesc memory\n");
 693                 return -ENOMEM;
 694         }
 695
 696         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 697
 698         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 699         if (ret) {
 700                 hid_err(hid, "reading report descriptor failed\n");
 701                 kfree(rdesc);
 702                 return -EIO;
 703         }
 704
 705         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 706
 707         ret = hid_parse_report(hid, rdesc, rsize);
 708         kfree(rdesc);
 709         if (ret) {
 710                 dbg_hid("parsing report descriptor failed\n");
 711                 return ret;
 712         }
 713
 714         return 0;
 715 }
 716
 717 static int i2c_hid_start(struct hid_device *hid)
 718 {
 719         struct i2c_client *client = hid->driver_data;
 720         struct i2c_hid *ihid = i2c_get_clientdata(client);
 721         int ret;
 722         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 723
 724         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 725         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 726         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 727
 728         if (bufsize > ihid->bufsize) {
 729                 disable_irq(client->irq);
 730                 i2c_hid_free_buffers(ihid);
 731
 732                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 733                 enable_irq(client->irq);
 734
 735                 if (ret)
 736                         return ret;
 737         }
 738
 739         return 0;
 740 }
 741
 742 static void i2c_hid_stop(struct hid_device *hid)
 743 {
 744         hid->claimed = 0;
 745 }
 746
 747 static int i2c_hid_open(struct hid_device *hid)
 748 {
 749         struct i2c_client *client = hid->driver_data;
 750         struct i2c_hid *ihid = i2c_get_clientdata(client);
 751         int ret = 0;
 752
 753         ret = pm_runtime_get_sync(&client->dev);
 754         if (ret < 0)
 755                 return ret;
 756
 757         set_bit(I2C_HID_STARTED, &ihid->flags);
 758         return 0;
 759 }
 760
 761 static void i2c_hid_close(struct hid_device *hid)
 762 {
 763         struct i2c_client *client = hid->driver_data;
 764         struct i2c_hid *ihid = i2c_get_clientdata(client);
 765
 766         clear_bit(I2C_HID_STARTED, &ihid->flags);
 767
 768         /* Save some power */
 769         pm_runtime_put(&client->dev);
 770 }
 771
 772 static int i2c_hid_power(struct hid_device *hid, int lvl)
 773 {
 774         struct i2c_client *client = hid->driver_data;
 775         struct i2c_hid *ihid = i2c_get_clientdata(client);
 776
 777         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 778
 779         switch (lvl) {
 780         case PM_HINT_FULLON:
 781                 pm_runtime_get_sync(&client->dev);
 782                 break;
 783         case PM_HINT_NORMAL:
 784                 pm_runtime_put(&client->dev);
 785                 break;
 786         }
 787         return 0;
 788 }
 789
 790 struct hid_ll_driver i2c_hid_ll_driver = {
 791         .parse = i2c_hid_parse,
 792         .start = i2c_hid_start,
 793         .stop = i2c_hid_stop,
 794         .open = i2c_hid_open,
 795         .close = i2c_hid_close,
 796         .power = i2c_hid_power,
 797         .output_report = i2c_hid_output_report,
 798         .raw_request = i2c_hid_raw_request,
 799 };
 800 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 801
 802 static int i2c_hid_init_irq(struct i2c_client *client)
 803 {
 804         struct i2c_hid *ihid = i2c_get_clientdata(client);
 805         unsigned long irqflags = 0;
 806         int ret;
 807
 808         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 809
 810         if (!irq_get_trigger_type(client->irq))
 811                 irqflags = IRQF_TRIGGER_LOW;
 812
 813         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 814                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 815         if (ret < 0) {
 816                 dev_warn(&client->dev,
 817                         "Could not register for %s interrupt, irq = %d,"
 818                         " ret = %d\n",
 819                         client->name, client->irq, ret);
 820
 821                 return ret;
 822         }
 823
 824         return 0;
 825 }
 826
 827 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 828 {
 829         struct i2c_client *client = ihid->client;
 830         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 831         unsigned int dsize;
 832         int ret;
 833
 834         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 835         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 836         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 837                                 sizeof(struct i2c_hid_desc));
 838         if (ret) {
 839                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 840                 return -ENODEV;
 841         }
 842
 843         /* Validate the length of HID descriptor, the 4 first bytes:
 844          * bytes 0-1 -> length
 845          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 846         /* check bcdVersion == 1.0 */
 847         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 848                 dev_err(&client->dev,
 849                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 850                         le16_to_cpu(hdesc->bcdVersion));
 851                 return -ENODEV;
 852         }
 853
 854         /* Descriptor length should be 30 bytes as per the specification */
 855         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 856         if (dsize != sizeof(struct i2c_hid_desc)) {
 857                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 858                         dsize);
 859                 return -ENODEV;
 860         }
 861         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 862         return 0;
 863 }
 864
 865 #ifdef CONFIG_ACPI
 866 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 867                 struct i2c_hid_platform_data *pdata)
 868 {
 869         static guid_t i2c_hid_guid =
 870                 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
 871                           0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
 872         union acpi_object *obj;
 873         struct acpi_device *adev;
 874         acpi_handle handle;
 875
 876         handle = ACPI_HANDLE(&client->dev);
 877         if (!handle || acpi_bus_get_device(handle, &adev))
 878                 return -ENODEV;
 879
 880         obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
 881                                       ACPI_TYPE_INTEGER);
 882         if (!obj) {
 883                 dev_err(&client->dev, "device _DSM execution failed\n");
 884                 return -ENODEV;
 885         }
 886
 887         pdata->hid_descriptor_address = obj->integer.value;
 888         ACPI_FREE(obj);
 889
 890         return 0;
 891 }
 892
 893 static void i2c_hid_acpi_fix_up_power(struct device *dev)
 894 {
 895         struct acpi_device *adev;
 896
 897         adev = ACPI_COMPANION(dev);
 898         if (adev)
 899                 acpi_device_fix_up_power(adev);
 900 }
 901
 902 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 903         {"ACPI0C50", 0 },
 904         {"PNP0C50", 0 },
 905         { },
 906 };
 907 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 908 #else
 909 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 910                 struct i2c_hid_platform_data *pdata)
 911 {
 912         return -ENODEV;
 913 }
 914
 915 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {}
 916 #endif
 917
 918 #ifdef CONFIG_OF
 919 static int i2c_hid_of_probe(struct i2c_client *client,
 920                 struct i2c_hid_platform_data *pdata)
 921 {
 922         struct device *dev = &client->dev;
 923         u32 val;
 924         int ret;
 925
 926         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 927         if (ret) {
 928                 dev_err(&client->dev, "HID register address not provided\n");
 929                 return -ENODEV;
 930         }
 931         if (val >> 16) {
 932                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 933                         val);
 934                 return -EINVAL;
 935         }
 936         pdata->hid_descriptor_address = val;
 937
 938         return 0;
 939 }
 940
 941 static const struct of_device_id i2c_hid_of_match[] = {
 942         { .compatible = "hid-over-i2c" },
 943         {},
 944 };
 945 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 946 #else
 947 static inline int i2c_hid_of_probe(struct i2c_client *client,
 948                 struct i2c_hid_platform_data *pdata)
 949 {
 950         return -ENODEV;
 951 }
 952 #endif
 953
 954 static void i2c_hid_fwnode_probe(struct i2c_client *client,
 955                                  struct i2c_hid_platform_data *pdata)
 956 {
 957         u32 val;
 958
 959         if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms",
 960                                       &val))
 961                 pdata->post_power_delay_ms = val;
 962 }
 963
 964 static int i2c_hid_probe(struct i2c_client *client,
 965                          const struct i2c_device_id *dev_id)
 966 {
 967         int ret;
 968         struct i2c_hid *ihid;
 969         struct hid_device *hid;
 970         __u16 hidRegister;
 971         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 972
 973         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 974
 975         if (!client->irq) {
 976                 dev_err(&client->dev,
 977                         "HID over i2c has not been provided an Int IRQ\n");
 978                 return -EINVAL;
 979         }
 980
 981         if (client->irq < 0) {
 982                 if (client->irq != -EPROBE_DEFER)
 983                         dev_err(&client->dev,
 984                                 "HID over i2c doesn't have a valid IRQ\n");
 985                 return client->irq;
 986         }
 987
 988         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 989         if (!ihid)
 990                 return -ENOMEM;
 991
 992         if (client->dev.of_node) {
 993                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 994                 if (ret)
 995                         goto err;
 996         } else if (!platform_data) {
 997                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 998                 if (ret) {
 999                         dev_err(&client->dev,
1000                                 "HID register address not provided\n");
1001                         goto err;
1002                 }
1003         } else {
1004                 ihid->pdata = *platform_data;
1005         }
1006
1007         /* Parse platform agnostic common properties from ACPI / device tree */
1008         i2c_hid_fwnode_probe(client, &ihid->pdata);
1009
1010         ihid->pdata.supply = devm_regulator_get(&client->dev, "vdd");
1011         if (IS_ERR(ihid->pdata.supply)) {
1012                 ret = PTR_ERR(ihid->pdata.supply);
1013                 if (ret != -EPROBE_DEFER)
1014                         dev_err(&client->dev, "Failed to get regulator: %d\n",
1015                                 ret);
1016                 goto err;
1017         }
1018
1019         ret = regulator_enable(ihid->pdata.supply);
1020         if (ret < 0) {
1021                 dev_err(&client->dev, "Failed to enable regulator: %d\n",
1022                         ret);
1023                 goto err;
1024         }
1025         if (ihid->pdata.post_power_delay_ms)
1026                 msleep(ihid->pdata.post_power_delay_ms);
1027
1028         i2c_set_clientdata(client, ihid);
1029
1030         ihid->client = client;
1031
1032         hidRegister = ihid->pdata.hid_descriptor_address;
1033         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1034
1035         init_waitqueue_head(&ihid->wait);
1036         mutex_init(&ihid->reset_lock);
1037
1038         /* we need to allocate the command buffer without knowing the maximum
1039          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1040          * real computation later. */
1041         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1042         if (ret < 0)
1043                 goto err_regulator;
1044
1045         i2c_hid_acpi_fix_up_power(&client->dev);
1046
1047         pm_runtime_get_noresume(&client->dev);
1048         pm_runtime_set_active(&client->dev);
1049         pm_runtime_enable(&client->dev);
1050         device_enable_async_suspend(&client->dev);
1051
1052         ret = i2c_hid_fetch_hid_descriptor(ihid);
1053         if (ret < 0)
1054                 goto err_pm;
1055
1056         ret = i2c_hid_init_irq(client);
1057         if (ret < 0)
1058                 goto err_pm;
1059
1060         hid = hid_allocate_device();
1061         if (IS_ERR(hid)) {
1062                 ret = PTR_ERR(hid);
1063                 goto err_irq;
1064         }
1065
1066         ihid->hid = hid;
1067
1068         hid->driver_data = client;
1069         hid->ll_driver = &i2c_hid_ll_driver;
1070         hid->dev.parent = &client->dev;
1071         hid->bus = BUS_I2C;
1072         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1073         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1074         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1075
1076         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1077                  client->name, hid->vendor, hid->product);
1078         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1079
1080         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1081
1082         ret = hid_add_device(hid);
1083         if (ret) {
1084                 if (ret != -ENODEV)
1085                         hid_err(client, "can't add hid device: %d\n", ret);
1086                 goto err_mem_free;
1087         }
1088
1089         pm_runtime_put(&client->dev);
1090         return 0;
1091
1092 err_mem_free:
1093         hid_destroy_device(hid);
1094
1095 err_irq:
1096         free_irq(client->irq, ihid);
1097
1098 err_pm:
1099         pm_runtime_put_noidle(&client->dev);
1100         pm_runtime_disable(&client->dev);
1101
1102 err_regulator:
1103         regulator_disable(ihid->pdata.supply);
1104
1105 err:
1106         i2c_hid_free_buffers(ihid);
1107         kfree(ihid);
1108         return ret;
1109 }
1110
1111 static int i2c_hid_remove(struct i2c_client *client)
1112 {
1113         struct i2c_hid *ihid = i2c_get_clientdata(client);
1114         struct hid_device *hid;
1115
1116         pm_runtime_get_sync(&client->dev);
1117         pm_runtime_disable(&client->dev);
1118         pm_runtime_set_suspended(&client->dev);
1119         pm_runtime_put_noidle(&client->dev);
1120
1121         hid = ihid->hid;
1122         hid_destroy_device(hid);
1123
1124         free_irq(client->irq, ihid);
1125
1126         if (ihid->bufsize)
1127                 i2c_hid_free_buffers(ihid);
1128
1129         regulator_disable(ihid->pdata.supply);
1130
1131         kfree(ihid);
1132
1133         return 0;
1134 }
1135
1136 static void i2c_hid_shutdown(struct i2c_client *client)
1137 {
1138         struct i2c_hid *ihid = i2c_get_clientdata(client);
1139
1140         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1141         free_irq(client->irq, ihid);
1142 }
1143
1144 #ifdef CONFIG_PM_SLEEP
1145 static int i2c_hid_suspend(struct device *dev)
1146 {
1147         struct i2c_client *client = to_i2c_client(dev);
1148         struct i2c_hid *ihid = i2c_get_clientdata(client);
1149         struct hid_device *hid = ihid->hid;
1150         int ret;
1151         int wake_status;
1152
1153         if (hid->driver && hid->driver->suspend) {
1154                 /*
1155                  * Wake up the device so that IO issues in
1156                  * HID driver's suspend code can succeed.
1157                  */
1158                 ret = pm_runtime_resume(dev);
1159                 if (ret < 0)
1160                         return ret;
1161
1162                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1163                 if (ret < 0)
1164                         return ret;
1165         }
1166
1167         if (!pm_runtime_suspended(dev)) {
1168                 /* Save some power */
1169                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1170
1171                 disable_irq(client->irq);
1172         }
1173
1174         if (device_may_wakeup(&client->dev)) {
1175                 wake_status = enable_irq_wake(client->irq);
1176                 if (!wake_status)
1177                         ihid->irq_wake_enabled = true;
1178                 else
1179                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1180                                 wake_status);
1181         } else {
1182                 ret = regulator_disable(ihid->pdata.supply);
1183                 if (ret < 0)
1184                         hid_warn(hid, "Failed to disable supply: %d\n", ret);
1185         }
1186
1187         return 0;
1188 }
1189
1190 static int i2c_hid_resume(struct device *dev)
1191 {
1192         int ret;
1193         struct i2c_client *client = to_i2c_client(dev);
1194         struct i2c_hid *ihid = i2c_get_clientdata(client);
1195         struct hid_device *hid = ihid->hid;
1196         int wake_status;
1197
1198         if (!device_may_wakeup(&client->dev)) {
1199                 ret = regulator_enable(ihid->pdata.supply);
1200                 if (ret < 0)
1201                         hid_warn(hid, "Failed to enable supply: %d\n", ret);
1202                 if (ihid->pdata.post_power_delay_ms)
1203                         msleep(ihid->pdata.post_power_delay_ms);
1204         } else if (ihid->irq_wake_enabled) {
1205                 wake_status = disable_irq_wake(client->irq);
1206                 if (!wake_status)
1207                         ihid->irq_wake_enabled = false;
1208                 else
1209                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1210                                 wake_status);
1211         }
1212
1213         /* We'll resume to full power */
1214         pm_runtime_disable(dev);
1215         pm_runtime_set_active(dev);
1216         pm_runtime_enable(dev);
1217
1218         enable_irq(client->irq);
1219         ret = i2c_hid_hwreset(client);
1220         if (ret)
1221                 return ret;
1222
1223         if (hid->driver && hid->driver->reset_resume) {
1224                 ret = hid->driver->reset_resume(hid);
1225                 return ret;
1226         }
1227
1228         return 0;
1229 }
1230 #endif
1231
1232 #ifdef CONFIG_PM
1233 static int i2c_hid_runtime_suspend(struct device *dev)
1234 {
1235         struct i2c_client *client = to_i2c_client(dev);
1236
1237         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1238         disable_irq(client->irq);
1239         return 0;
1240 }
1241
1242 static int i2c_hid_runtime_resume(struct device *dev)
1243 {
1244         struct i2c_client *client = to_i2c_client(dev);
1245
1246         enable_irq(client->irq);
1247         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1248         return 0;
1249 }
1250 #endif
1251
1252 static const struct dev_pm_ops i2c_hid_pm = {
1253         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1254         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1255                            NULL)
1256 };
1257
1258 static const struct i2c_device_id i2c_hid_id_table[] = {
1259         { "hid", 0 },
1260         { "hid-over-i2c", 0 },
1261         { },
1262 };
1263 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1264
1265
1266 static struct i2c_driver i2c_hid_driver = {
1267         .driver = {
1268                 .name   = "i2c_hid",
1269                 .pm     = &i2c_hid_pm,
1270                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1271                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1272         },
1273
1274         .probe          = i2c_hid_probe,
1275         .remove         = i2c_hid_remove,
1276         .shutdown       = i2c_hid_shutdown,
1277         .id_table       = i2c_hid_id_table,
1278 };
1279
1280 module_i2c_driver(i2c_hid_driver);
1281
1282 MODULE_DESCRIPTION("HID over I2C core driver");
1283 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1284 MODULE_LICENSE("GPL");