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

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