drivers/hid/i2c-hid/i2c-hid.c

   1 /*
   2  * HID over I2C protocol implementation
   3  *
   4  * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
   5  * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
   6  * Copyright (c) 2012 Red Hat, Inc
   7  *
   8  * This code is partly based on "USB HID support for Linux":
   9  *
  10  *  Copyright (c) 1999 Andreas Gal
  11  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
  12  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
  13  *  Copyright (c) 2007-2008 Oliver Neukum
  14  *  Copyright (c) 2006-2010 Jiri Kosina
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file COPYING in the main directory of this archive for
  18  * more details.
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/i2c.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/input.h>
  25 #include <linux/delay.h>
  26 #include <linux/slab.h>
  27 #include <linux/pm.h>
  28 #include <linux/pm_runtime.h>
  29 #include <linux/device.h>
  30 #include <linux/wait.h>
  31 #include <linux/err.h>
  32 #include <linux/string.h>
  33 #include <linux/list.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/kernel.h>
  36 #include <linux/hid.h>
  37 #include <linux/mutex.h>
  38 #include <linux/acpi.h>
  39 #include <linux/of.h>
  40 #include <linux/gpio/consumer.h>
  41
  42 #include <linux/i2c/i2c-hid.h>
  43
  44 /* flags */
  45 #define I2C_HID_STARTED         0
  46 #define I2C_HID_RESET_PENDING   1
  47 #define I2C_HID_READ_PENDING    2
  48
  49 #define I2C_HID_PWR_ON          0x00
  50 #define I2C_HID_PWR_SLEEP       0x01
  51
  52 /* debug option */
  53 static bool debug;
  54 module_param(debug, bool, 0444);
  55 MODULE_PARM_DESC(debug, "print a lot of debug information");
  56
  57 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  58 do {                                                                      \
  59         if (debug)                                                        \
  60                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  61 } while (0)
  62
  63 struct i2c_hid_desc {
  64         __le16 wHIDDescLength;
  65         __le16 bcdVersion;
  66         __le16 wReportDescLength;
  67         __le16 wReportDescRegister;
  68         __le16 wInputRegister;
  69         __le16 wMaxInputLength;
  70         __le16 wOutputRegister;
  71         __le16 wMaxOutputLength;
  72         __le16 wCommandRegister;
  73         __le16 wDataRegister;
  74         __le16 wVendorID;
  75         __le16 wProductID;
  76         __le16 wVersionID;
  77         __le32 reserved;
  78 } __packed;
  79
  80 struct i2c_hid_cmd {
  81         unsigned int registerIndex;
  82         __u8 opcode;
  83         unsigned int length;
  84         bool wait;
  85 };
  86
  87 union command {
  88         u8 data[0];
  89         struct cmd {
  90                 __le16 reg;
  91                 __u8 reportTypeID;
  92                 __u8 opcode;
  93         } __packed c;
  94 };
  95
  96 #define I2C_HID_CMD(opcode_) \
  97         .opcode = opcode_, .length = 4, \
  98         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
  99
 100 /* fetch HID descriptor */
 101 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 102 /* fetch report descriptors */
 103 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 104                 .registerIndex = offsetof(struct i2c_hid_desc,
 105                         wReportDescRegister),
 106                 .opcode = 0x00,
 107                 .length = 2 };
 108 /* commands */
 109 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 110                                                           .wait = true };
 111 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 112 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 113 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 114 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 115
 116 /*
 117  * These definitions are not used here, but are defined by the spec.
 118  * Keeping them here for documentation purposes.
 119  *
 120  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 121  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 122  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 123  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 124  */
 125
 126 static DEFINE_MUTEX(i2c_hid_open_mut);
 127
 128 /* The main device structure */
 129 struct i2c_hid {
 130         struct i2c_client       *client;        /* i2c client */
 131         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 132         union {
 133                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 134                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 135         };
 136         __le16                  wHIDDescRegister; /* location of the i2c
 137                                                    * register of the HID
 138                                                    * descriptor. */
 139         unsigned int            bufsize;        /* i2c buffer size */
 140         u8                      *inbuf;         /* Input buffer */
 141         u8                      *rawbuf;        /* Raw Input buffer */
 142         u8                      *cmdbuf;        /* Command buffer */
 143         u8                      *argsbuf;       /* Command arguments buffer */
 144
 145         unsigned long           flags;          /* device flags */
 146
 147         wait_queue_head_t       wait;           /* For waiting the interrupt */
 148         struct gpio_desc        *desc;
 149         int                     irq;
 150
 151         struct i2c_hid_platform_data pdata;
 152
 153         bool                    irq_wake_enabled;
 154 };
 155
 156 static int __i2c_hid_command(struct i2c_client *client,
 157                 const struct i2c_hid_cmd *command, u8 reportID,
 158                 u8 reportType, u8 *args, int args_len,
 159                 unsigned char *buf_recv, int data_len)
 160 {
 161         struct i2c_hid *ihid = i2c_get_clientdata(client);
 162         union command *cmd = (union command *)ihid->cmdbuf;
 163         int ret;
 164         struct i2c_msg msg[2];
 165         int msg_num = 1;
 166
 167         int length = command->length;
 168         bool wait = command->wait;
 169         unsigned int registerIndex = command->registerIndex;
 170
 171         /* special case for hid_descr_cmd */
 172         if (command == &hid_descr_cmd) {
 173                 cmd->c.reg = ihid->wHIDDescRegister;
 174         } else {
 175                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 176                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 177         }
 178
 179         if (length > 2) {
 180                 cmd->c.opcode = command->opcode;
 181                 cmd->c.reportTypeID = reportID | reportType << 4;
 182         }
 183
 184         memcpy(cmd->data + length, args, args_len);
 185         length += args_len;
 186
 187         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 188
 189         msg[0].addr = client->addr;
 190         msg[0].flags = client->flags & I2C_M_TEN;
 191         msg[0].len = length;
 192         msg[0].buf = cmd->data;
 193         if (data_len > 0) {
 194                 msg[1].addr = client->addr;
 195                 msg[1].flags = client->flags & I2C_M_TEN;
 196                 msg[1].flags |= I2C_M_RD;
 197                 msg[1].len = data_len;
 198                 msg[1].buf = buf_recv;
 199                 msg_num = 2;
 200                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 201         }
 202
 203         if (wait)
 204                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 205
 206         ret = i2c_transfer(client->adapter, msg, msg_num);
 207
 208         if (data_len > 0)
 209                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 210
 211         if (ret != msg_num)
 212                 return ret < 0 ? ret : -EIO;
 213
 214         ret = 0;
 215
 216         if (wait) {
 217                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 218                 if (!wait_event_timeout(ihid->wait,
 219                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 220                                 msecs_to_jiffies(5000)))
 221                         ret = -ENODATA;
 222                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 223         }
 224
 225         return ret;
 226 }
 227
 228 static int i2c_hid_command(struct i2c_client *client,
 229                 const struct i2c_hid_cmd *command,
 230                 unsigned char *buf_recv, int data_len)
 231 {
 232         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 233                                 buf_recv, data_len);
 234 }
 235
 236 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 237                 u8 reportID, unsigned char *buf_recv, int data_len)
 238 {
 239         struct i2c_hid *ihid = i2c_get_clientdata(client);
 240         u8 args[3];
 241         int ret;
 242         int args_len = 0;
 243         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 244
 245         i2c_hid_dbg(ihid, "%s\n", __func__);
 246
 247         if (reportID >= 0x0F) {
 248                 args[args_len++] = reportID;
 249                 reportID = 0x0F;
 250         }
 251
 252         args[args_len++] = readRegister & 0xFF;
 253         args[args_len++] = readRegister >> 8;
 254
 255         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 256                 reportType, args, args_len, buf_recv, data_len);
 257         if (ret) {
 258                 dev_err(&client->dev,
 259                         "failed to retrieve report from device.\n");
 260                 return ret;
 261         }
 262
 263         return 0;
 264 }
 265
 266 /**
 267  * i2c_hid_set_or_send_report: forward an incoming report to the device
 268  * @client: the i2c_client of the device
 269  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 270  * @reportID: the report ID
 271  * @buf: the actual data to transfer, without the report ID
 272  * @len: size of buf
 273  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 274  */
 275 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 276                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 277 {
 278         struct i2c_hid *ihid = i2c_get_clientdata(client);
 279         u8 *args = ihid->argsbuf;
 280         const struct i2c_hid_cmd *hidcmd;
 281         int ret;
 282         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 283         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 284         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 285         u16 size;
 286         int args_len;
 287         int index = 0;
 288
 289         i2c_hid_dbg(ihid, "%s\n", __func__);
 290
 291         if (data_len > ihid->bufsize)
 292                 return -EINVAL;
 293
 294         size =          2                       /* size */ +
 295                         (reportID ? 1 : 0)      /* reportID */ +
 296                         data_len                /* buf */;
 297         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 298                         2                       /* dataRegister */ +
 299                         size                    /* args */;
 300
 301         if (!use_data && maxOutputLength == 0)
 302                 return -ENOSYS;
 303
 304         if (reportID >= 0x0F) {
 305                 args[index++] = reportID;
 306                 reportID = 0x0F;
 307         }
 308
 309         /*
 310          * use the data register for feature reports or if the device does not
 311          * support the output register
 312          */
 313         if (use_data) {
 314                 args[index++] = dataRegister & 0xFF;
 315                 args[index++] = dataRegister >> 8;
 316                 hidcmd = &hid_set_report_cmd;
 317         } else {
 318                 args[index++] = outputRegister & 0xFF;
 319                 args[index++] = outputRegister >> 8;
 320                 hidcmd = &hid_no_cmd;
 321         }
 322
 323         args[index++] = size & 0xFF;
 324         args[index++] = size >> 8;
 325
 326         if (reportID)
 327                 args[index++] = reportID;
 328
 329         memcpy(&args[index], buf, data_len);
 330
 331         ret = __i2c_hid_command(client, hidcmd, reportID,
 332                 reportType, args, args_len, NULL, 0);
 333         if (ret) {
 334                 dev_err(&client->dev, "failed to set a report to device.\n");
 335                 return ret;
 336         }
 337
 338         return data_len;
 339 }
 340
 341 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 342 {
 343         struct i2c_hid *ihid = i2c_get_clientdata(client);
 344         int ret;
 345
 346         i2c_hid_dbg(ihid, "%s\n", __func__);
 347
 348         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 349                 0, NULL, 0, NULL, 0);
 350         if (ret)
 351                 dev_err(&client->dev, "failed to change power setting.\n");
 352
 353         return ret;
 354 }
 355
 356 static int i2c_hid_hwreset(struct i2c_client *client)
 357 {
 358         struct i2c_hid *ihid = i2c_get_clientdata(client);
 359         int ret;
 360
 361         i2c_hid_dbg(ihid, "%s\n", __func__);
 362
 363         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 364         if (ret)
 365                 return ret;
 366
 367         /*
 368          * The HID over I2C specification states that if a DEVICE needs time
 369          * after the PWR_ON request, it should utilise CLOCK stretching.
 370          * However, it has been observered that the Windows driver provides a
 371          * 1ms sleep between the PWR_ON and RESET requests and that some devices
 372          * rely on this.
 373          */
 374         usleep_range(1000, 5000);
 375
 376         i2c_hid_dbg(ihid, "resetting...\n");
 377
 378         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 379         if (ret) {
 380                 dev_err(&client->dev, "failed to reset device.\n");
 381                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 382                 return ret;
 383         }
 384
 385         return 0;
 386 }
 387
 388 static void i2c_hid_get_input(struct i2c_hid *ihid)
 389 {
 390         int ret;
 391         u32 ret_size;
 392         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 393
 394         if (size > ihid->bufsize)
 395                 size = ihid->bufsize;
 396
 397         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 398         if (ret != size) {
 399                 if (ret < 0)
 400                         return;
 401
 402                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 403                         __func__, ret, size);
 404                 return;
 405         }
 406
 407         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 408
 409         if (!ret_size) {
 410                 /* host or device initiated RESET completed */
 411                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 412                         wake_up(&ihid->wait);
 413                 return;
 414         }
 415
 416         if ((ret_size > size) || (ret_size < 2)) {
 417                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 418                         __func__, size, ret_size);
 419                 return;
 420         }
 421
 422         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 423
 424         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 425                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 426                                 ret_size - 2, 1);
 427
 428         return;
 429 }
 430
 431 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 432 {
 433         struct i2c_hid *ihid = dev_id;
 434
 435         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 436                 return IRQ_HANDLED;
 437
 438         i2c_hid_get_input(ihid);
 439
 440         return IRQ_HANDLED;
 441 }
 442
 443 static int i2c_hid_get_report_length(struct hid_report *report)
 444 {
 445         return ((report->size - 1) >> 3) + 1 +
 446                 report->device->report_enum[report->type].numbered + 2;
 447 }
 448
 449 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 450         size_t bufsize)
 451 {
 452         struct hid_device *hid = report->device;
 453         struct i2c_client *client = hid->driver_data;
 454         struct i2c_hid *ihid = i2c_get_clientdata(client);
 455         unsigned int size, ret_size;
 456
 457         size = i2c_hid_get_report_length(report);
 458         if (i2c_hid_get_report(client,
 459                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 460                         report->id, buffer, size))
 461                 return;
 462
 463         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
 464
 465         ret_size = buffer[0] | (buffer[1] << 8);
 466
 467         if (ret_size != size) {
 468                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 469                         __func__, size, ret_size);
 470                 return;
 471         }
 472
 473         /* hid->driver_lock is held as we are in probe function,
 474          * we just need to setup the input fields, so using
 475          * hid_report_raw_event is safe. */
 476         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 477 }
 478
 479 /*
 480  * Initialize all reports
 481  */
 482 static void i2c_hid_init_reports(struct hid_device *hid)
 483 {
 484         struct hid_report *report;
 485         struct i2c_client *client = hid->driver_data;
 486         struct i2c_hid *ihid = i2c_get_clientdata(client);
 487         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 488
 489         if (!inbuf) {
 490                 dev_err(&client->dev, "can not retrieve initial reports\n");
 491                 return;
 492         }
 493
 494         /*
 495          * The device must be powered on while we fetch initial reports
 496          * from it.
 497          */
 498         pm_runtime_get_sync(&client->dev);
 499
 500         list_for_each_entry(report,
 501                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 502                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 503
 504         pm_runtime_put(&client->dev);
 505
 506         kfree(inbuf);
 507 }
 508
 509 /*
 510  * Traverse the supplied list of reports and find the longest
 511  */
 512 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 513                 unsigned int *max)
 514 {
 515         struct hid_report *report;
 516         unsigned int size;
 517
 518         /* We should not rely on wMaxInputLength, as some devices may set it to
 519          * a wrong length. */
 520         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 521                 size = i2c_hid_get_report_length(report);
 522                 if (*max < size)
 523                         *max = size;
 524         }
 525 }
 526
 527 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 528 {
 529         kfree(ihid->inbuf);
 530         kfree(ihid->rawbuf);
 531         kfree(ihid->argsbuf);
 532         kfree(ihid->cmdbuf);
 533         ihid->inbuf = NULL;
 534         ihid->rawbuf = NULL;
 535         ihid->cmdbuf = NULL;
 536         ihid->argsbuf = NULL;
 537         ihid->bufsize = 0;
 538 }
 539
 540 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 541 {
 542         /* the worst case is computed from the set_report command with a
 543          * reportID > 15 and the maximum report length */
 544         int args_len = sizeof(__u8) + /* ReportID */
 545                        sizeof(__u8) + /* optional ReportID byte */
 546                        sizeof(__u16) + /* data register */
 547                        sizeof(__u16) + /* size of the report */
 548                        report_size; /* report */
 549
 550         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 551         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 552         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 553         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 554
 555         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 556                 i2c_hid_free_buffers(ihid);
 557                 return -ENOMEM;
 558         }
 559
 560         ihid->bufsize = report_size;
 561
 562         return 0;
 563 }
 564
 565 static int i2c_hid_get_raw_report(struct hid_device *hid,
 566                 unsigned char report_number, __u8 *buf, size_t count,
 567                 unsigned char report_type)
 568 {
 569         struct i2c_client *client = hid->driver_data;
 570         struct i2c_hid *ihid = i2c_get_clientdata(client);
 571         size_t ret_count, ask_count;
 572         int ret;
 573
 574         if (report_type == HID_OUTPUT_REPORT)
 575                 return -EINVAL;
 576
 577         /* +2 bytes to include the size of the reply in the query buffer */
 578         ask_count = min(count + 2, (size_t)ihid->bufsize);
 579
 580         ret = i2c_hid_get_report(client,
 581                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 582                         report_number, ihid->rawbuf, ask_count);
 583
 584         if (ret < 0)
 585                 return ret;
 586
 587         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 588
 589         if (ret_count <= 2)
 590                 return 0;
 591
 592         ret_count = min(ret_count, ask_count);
 593
 594         /* The query buffer contains the size, dropping it in the reply */
 595         count = min(count, ret_count - 2);
 596         memcpy(buf, ihid->rawbuf + 2, count);
 597
 598         return count;
 599 }
 600
 601 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 602                 size_t count, unsigned char report_type, bool use_data)
 603 {
 604         struct i2c_client *client = hid->driver_data;
 605         int report_id = buf[0];
 606         int ret;
 607
 608         if (report_type == HID_INPUT_REPORT)
 609                 return -EINVAL;
 610
 611         if (report_id) {
 612                 buf++;
 613                 count--;
 614         }
 615
 616         ret = i2c_hid_set_or_send_report(client,
 617                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 618                                 report_id, buf, count, use_data);
 619
 620         if (report_id && ret >= 0)
 621                 ret++; /* add report_id to the number of transfered bytes */
 622
 623         return ret;
 624 }
 625
 626 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 627                 size_t count)
 628 {
 629         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 630                         false);
 631 }
 632
 633 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 634                                __u8 *buf, size_t len, unsigned char rtype,
 635                                int reqtype)
 636 {
 637         switch (reqtype) {
 638         case HID_REQ_GET_REPORT:
 639                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 640         case HID_REQ_SET_REPORT:
 641                 if (buf[0] != reportnum)
 642                         return -EINVAL;
 643                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 644         default:
 645                 return -EIO;
 646         }
 647 }
 648
 649 static int i2c_hid_parse(struct hid_device *hid)
 650 {
 651         struct i2c_client *client = hid->driver_data;
 652         struct i2c_hid *ihid = i2c_get_clientdata(client);
 653         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 654         unsigned int rsize;
 655         char *rdesc;
 656         int ret;
 657         int tries = 3;
 658
 659         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 660
 661         rsize = le16_to_cpu(hdesc->wReportDescLength);
 662         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 663                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 664                 return -EINVAL;
 665         }
 666
 667         do {
 668                 ret = i2c_hid_hwreset(client);
 669                 if (ret)
 670                         msleep(1000);
 671         } while (tries-- > 0 && ret);
 672
 673         if (ret)
 674                 return ret;
 675
 676         rdesc = kzalloc(rsize, GFP_KERNEL);
 677
 678         if (!rdesc) {
 679                 dbg_hid("couldn't allocate rdesc memory\n");
 680                 return -ENOMEM;
 681         }
 682
 683         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 684
 685         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 686         if (ret) {
 687                 hid_err(hid, "reading report descriptor failed\n");
 688                 kfree(rdesc);
 689                 return -EIO;
 690         }
 691
 692         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 693
 694         ret = hid_parse_report(hid, rdesc, rsize);
 695         kfree(rdesc);
 696         if (ret) {
 697                 dbg_hid("parsing report descriptor failed\n");
 698                 return ret;
 699         }
 700
 701         return 0;
 702 }
 703
 704 static int i2c_hid_start(struct hid_device *hid)
 705 {
 706         struct i2c_client *client = hid->driver_data;
 707         struct i2c_hid *ihid = i2c_get_clientdata(client);
 708         int ret;
 709         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 710
 711         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 712         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 713         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 714
 715         if (bufsize > ihid->bufsize) {
 716                 i2c_hid_free_buffers(ihid);
 717
 718                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 719
 720                 if (ret)
 721                         return ret;
 722         }
 723
 724         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 725                 i2c_hid_init_reports(hid);
 726
 727         return 0;
 728 }
 729
 730 static void i2c_hid_stop(struct hid_device *hid)
 731 {
 732         hid->claimed = 0;
 733 }
 734
 735 static int i2c_hid_open(struct hid_device *hid)
 736 {
 737         struct i2c_client *client = hid->driver_data;
 738         struct i2c_hid *ihid = i2c_get_clientdata(client);
 739         int ret = 0;
 740
 741         mutex_lock(&i2c_hid_open_mut);
 742         if (!hid->open++) {
 743                 ret = pm_runtime_get_sync(&client->dev);
 744                 if (ret < 0) {
 745                         hid->open--;
 746                         goto done;
 747                 }
 748                 set_bit(I2C_HID_STARTED, &ihid->flags);
 749         }
 750 done:
 751         mutex_unlock(&i2c_hid_open_mut);
 752         return ret < 0 ? ret : 0;
 753 }
 754
 755 static void i2c_hid_close(struct hid_device *hid)
 756 {
 757         struct i2c_client *client = hid->driver_data;
 758         struct i2c_hid *ihid = i2c_get_clientdata(client);
 759
 760         /* protecting hid->open to make sure we don't restart
 761          * data acquistion due to a resumption we no longer
 762          * care about
 763          */
 764         mutex_lock(&i2c_hid_open_mut);
 765         if (!--hid->open) {
 766                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 767
 768                 /* Save some power */
 769                 pm_runtime_put(&client->dev);
 770         }
 771         mutex_unlock(&i2c_hid_open_mut);
 772 }
 773
 774 static int i2c_hid_power(struct hid_device *hid, int lvl)
 775 {
 776         struct i2c_client *client = hid->driver_data;
 777         struct i2c_hid *ihid = i2c_get_clientdata(client);
 778
 779         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 780
 781         switch (lvl) {
 782         case PM_HINT_FULLON:
 783                 pm_runtime_get_sync(&client->dev);
 784                 break;
 785         case PM_HINT_NORMAL:
 786                 pm_runtime_put(&client->dev);
 787                 break;
 788         }
 789         return 0;
 790 }
 791
 792 static struct hid_ll_driver i2c_hid_ll_driver = {
 793         .parse = i2c_hid_parse,
 794         .start = i2c_hid_start,
 795         .stop = i2c_hid_stop,
 796         .open = i2c_hid_open,
 797         .close = i2c_hid_close,
 798         .power = i2c_hid_power,
 799         .output_report = i2c_hid_output_report,
 800         .raw_request = i2c_hid_raw_request,
 801 };
 802
 803 static int i2c_hid_init_irq(struct i2c_client *client)
 804 {
 805         struct i2c_hid *ihid = i2c_get_clientdata(client);
 806         int ret;
 807
 808         dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
 809
 810         ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
 811                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 812                         client->name, ihid);
 813         if (ret < 0) {
 814                 dev_warn(&client->dev,
 815                         "Could not register for %s interrupt, irq = %d,"
 816                         " ret = %d\n",
 817                         client->name, ihid->irq, ret);
 818
 819                 return ret;
 820         }
 821
 822         return 0;
 823 }
 824
 825 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 826 {
 827         struct i2c_client *client = ihid->client;
 828         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 829         unsigned int dsize;
 830         int ret;
 831
 832         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 833         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 834         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 835                                 sizeof(struct i2c_hid_desc));
 836         if (ret) {
 837                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 838                 return -ENODEV;
 839         }
 840
 841         /* Validate the length of HID descriptor, the 4 first bytes:
 842          * bytes 0-1 -> length
 843          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 844         /* check bcdVersion == 1.0 */
 845         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 846                 dev_err(&client->dev,
 847                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 848                         le16_to_cpu(hdesc->bcdVersion));
 849                 return -ENODEV;
 850         }
 851
 852         /* Descriptor length should be 30 bytes as per the specification */
 853         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 854         if (dsize != sizeof(struct i2c_hid_desc)) {
 855                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 856                         dsize);
 857                 return -ENODEV;
 858         }
 859         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 860         return 0;
 861 }
 862
 863 #ifdef CONFIG_ACPI
 864
 865 /* Default GPIO mapping */
 866 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
 867 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
 868         { "gpios", &i2c_hid_irq_gpio, 1 },
 869         { },
 870 };
 871
 872 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 873                 struct i2c_hid_platform_data *pdata)
 874 {
 875         static u8 i2c_hid_guid[] = {
 876                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 877                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 878         };
 879         union acpi_object *obj;
 880         struct acpi_device *adev;
 881         acpi_handle handle;
 882         int ret;
 883
 884         handle = ACPI_HANDLE(&client->dev);
 885         if (!handle || acpi_bus_get_device(handle, &adev))
 886                 return -ENODEV;
 887
 888         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 889                                       ACPI_TYPE_INTEGER);
 890         if (!obj) {
 891                 dev_err(&client->dev, "device _DSM execution failed\n");
 892                 return -ENODEV;
 893         }
 894
 895         pdata->hid_descriptor_address = obj->integer.value;
 896         ACPI_FREE(obj);
 897
 898         /* GPIOs are optional */
 899         ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
 900         return ret < 0 && ret != -ENXIO ? ret : 0;
 901 }
 902
 903 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 904         {"ACPI0C50", 0 },
 905         {"PNP0C50", 0 },
 906         { },
 907 };
 908 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 909 #else
 910 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 911                 struct i2c_hid_platform_data *pdata)
 912 {
 913         return -ENODEV;
 914 }
 915 #endif
 916
 917 #ifdef CONFIG_OF
 918 static int i2c_hid_of_probe(struct i2c_client *client,
 919                 struct i2c_hid_platform_data *pdata)
 920 {
 921         struct device *dev = &client->dev;
 922         u32 val;
 923         int ret;
 924
 925         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 926         if (ret) {
 927                 dev_err(&client->dev, "HID register address not provided\n");
 928                 return -ENODEV;
 929         }
 930         if (val >> 16) {
 931                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 932                         val);
 933                 return -EINVAL;
 934         }
 935         pdata->hid_descriptor_address = val;
 936
 937         return 0;
 938 }
 939
 940 static const struct of_device_id i2c_hid_of_match[] = {
 941         { .compatible = "hid-over-i2c" },
 942         {},
 943 };
 944 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 945 #else
 946 static inline int i2c_hid_of_probe(struct i2c_client *client,
 947                 struct i2c_hid_platform_data *pdata)
 948 {
 949         return -ENODEV;
 950 }
 951 #endif
 952
 953 static int i2c_hid_probe(struct i2c_client *client,
 954                          const struct i2c_device_id *dev_id)
 955 {
 956         int ret;
 957         struct i2c_hid *ihid;
 958         struct hid_device *hid;
 959         __u16 hidRegister;
 960         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 961
 962         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 963
 964         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 965         if (!ihid)
 966                 return -ENOMEM;
 967
 968         if (client->dev.of_node) {
 969                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 970                 if (ret)
 971                         goto err;
 972         } else if (!platform_data) {
 973                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 974                 if (ret) {
 975                         dev_err(&client->dev,
 976                                 "HID register address not provided\n");
 977                         goto err;
 978                 }
 979         } else {
 980                 ihid->pdata = *platform_data;
 981         }
 982
 983         if (client->irq > 0) {
 984                 ihid->irq = client->irq;
 985         } else if (ACPI_COMPANION(&client->dev)) {
 986                 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
 987                 if (IS_ERR(ihid->desc)) {
 988                         dev_err(&client->dev, "Failed to get GPIO interrupt\n");
 989                         return PTR_ERR(ihid->desc);
 990                 }
 991
 992                 ihid->irq = gpiod_to_irq(ihid->desc);
 993                 if (ihid->irq < 0) {
 994                         gpiod_put(ihid->desc);
 995                         dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
 996                         return ihid->irq;
 997                 }
 998         }
 999
1000         i2c_set_clientdata(client, ihid);
1001
1002         ihid->client = client;
1003
1004         hidRegister = ihid->pdata.hid_descriptor_address;
1005         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1006
1007         init_waitqueue_head(&ihid->wait);
1008
1009         /* we need to allocate the command buffer without knowing the maximum
1010          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1011          * real computation later. */
1012         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1013         if (ret < 0)
1014                 goto err;
1015
1016         pm_runtime_get_noresume(&client->dev);
1017         pm_runtime_set_active(&client->dev);
1018         pm_runtime_enable(&client->dev);
1019
1020         /* Make sure there is something at this address */
1021         ret = i2c_smbus_read_byte(client);
1022         if (ret < 0) {
1023                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
1024                 ret = -ENXIO;
1025                 goto err_pm;
1026         }
1027
1028         ret = i2c_hid_fetch_hid_descriptor(ihid);
1029         if (ret < 0)
1030                 goto err_pm;
1031
1032         ret = i2c_hid_init_irq(client);
1033         if (ret < 0)
1034                 goto err_pm;
1035
1036         hid = hid_allocate_device();
1037         if (IS_ERR(hid)) {
1038                 ret = PTR_ERR(hid);
1039                 goto err_irq;
1040         }
1041
1042         ihid->hid = hid;
1043
1044         hid->driver_data = client;
1045         hid->ll_driver = &i2c_hid_ll_driver;
1046         hid->dev.parent = &client->dev;
1047         hid->bus = BUS_I2C;
1048         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1049         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1050         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1051
1052         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1053                  client->name, hid->vendor, hid->product);
1054         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1055
1056         ret = hid_add_device(hid);
1057         if (ret) {
1058                 if (ret != -ENODEV)
1059                         hid_err(client, "can't add hid device: %d\n", ret);
1060                 goto err_mem_free;
1061         }
1062
1063         pm_runtime_put(&client->dev);
1064         return 0;
1065
1066 err_mem_free:
1067         hid_destroy_device(hid);
1068
1069 err_irq:
1070         free_irq(ihid->irq, ihid);
1071
1072 err_pm:
1073         pm_runtime_put_noidle(&client->dev);
1074         pm_runtime_disable(&client->dev);
1075
1076 err:
1077         if (ihid->desc)
1078                 gpiod_put(ihid->desc);
1079
1080         i2c_hid_free_buffers(ihid);
1081         kfree(ihid);
1082         return ret;
1083 }
1084
1085 static int i2c_hid_remove(struct i2c_client *client)
1086 {
1087         struct i2c_hid *ihid = i2c_get_clientdata(client);
1088         struct hid_device *hid;
1089
1090         pm_runtime_get_sync(&client->dev);
1091         pm_runtime_disable(&client->dev);
1092         pm_runtime_set_suspended(&client->dev);
1093         pm_runtime_put_noidle(&client->dev);
1094
1095         hid = ihid->hid;
1096         hid_destroy_device(hid);
1097
1098         free_irq(ihid->irq, ihid);
1099
1100         if (ihid->bufsize)
1101                 i2c_hid_free_buffers(ihid);
1102
1103         if (ihid->desc)
1104                 gpiod_put(ihid->desc);
1105
1106         kfree(ihid);
1107
1108         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1109
1110         return 0;
1111 }
1112
1113 #ifdef CONFIG_PM_SLEEP
1114 static int i2c_hid_suspend(struct device *dev)
1115 {
1116         struct i2c_client *client = to_i2c_client(dev);
1117         struct i2c_hid *ihid = i2c_get_clientdata(client);
1118         struct hid_device *hid = ihid->hid;
1119         int ret = 0;
1120         int wake_status;
1121
1122         if (hid->driver && hid->driver->suspend)
1123                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1124
1125         disable_irq(ihid->irq);
1126         if (device_may_wakeup(&client->dev)) {
1127                 wake_status = enable_irq_wake(ihid->irq);
1128                 if (!wake_status)
1129                         ihid->irq_wake_enabled = true;
1130                 else
1131                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1132                                 wake_status);
1133         }
1134
1135         /* Save some power */
1136         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1137
1138         return ret;
1139 }
1140
1141 static int i2c_hid_resume(struct device *dev)
1142 {
1143         int ret;
1144         struct i2c_client *client = to_i2c_client(dev);
1145         struct i2c_hid *ihid = i2c_get_clientdata(client);
1146         struct hid_device *hid = ihid->hid;
1147         int wake_status;
1148
1149         enable_irq(ihid->irq);
1150         ret = i2c_hid_hwreset(client);
1151         if (ret)
1152                 return ret;
1153
1154         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1155                 wake_status = disable_irq_wake(ihid->irq);
1156                 if (!wake_status)
1157                         ihid->irq_wake_enabled = false;
1158                 else
1159                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1160                                 wake_status);
1161         }
1162
1163         if (hid->driver && hid->driver->reset_resume) {
1164                 ret = hid->driver->reset_resume(hid);
1165                 return ret;
1166         }
1167
1168         return 0;
1169 }
1170 #endif
1171
1172 #ifdef CONFIG_PM
1173 static int i2c_hid_runtime_suspend(struct device *dev)
1174 {
1175         struct i2c_client *client = to_i2c_client(dev);
1176         struct i2c_hid *ihid = i2c_get_clientdata(client);
1177
1178         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1179         disable_irq(ihid->irq);
1180         return 0;
1181 }
1182
1183 static int i2c_hid_runtime_resume(struct device *dev)
1184 {
1185         struct i2c_client *client = to_i2c_client(dev);
1186         struct i2c_hid *ihid = i2c_get_clientdata(client);
1187
1188         enable_irq(ihid->irq);
1189         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1190         return 0;
1191 }
1192 #endif
1193
1194 static const struct dev_pm_ops i2c_hid_pm = {
1195         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1196         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1197                            NULL)
1198 };
1199
1200 static const struct i2c_device_id i2c_hid_id_table[] = {
1201         { "hid", 0 },
1202         { },
1203 };
1204 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1205
1206
1207 static struct i2c_driver i2c_hid_driver = {
1208         .driver = {
1209                 .name   = "i2c_hid",
1210                 .owner  = THIS_MODULE,
1211                 .pm     = &i2c_hid_pm,
1212                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1213                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1214         },
1215
1216         .probe          = i2c_hid_probe,
1217         .remove         = i2c_hid_remove,
1218
1219         .id_table       = i2c_hid_id_table,
1220 };
1221
1222 module_i2c_driver(i2c_hid_driver);
1223
1224 MODULE_DESCRIPTION("HID over I2C core driver");
1225 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1226 MODULE_LICENSE("GPL");