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/device.h>
  29 #include <linux/wait.h>
  30 #include <linux/err.h>
  31 #include <linux/string.h>
  32 #include <linux/list.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/kernel.h>
  35 #include <linux/hid.h>
  36 #include <linux/mutex.h>
  37 #include <linux/acpi.h>
  38
  39 #include <linux/i2c/i2c-hid.h>
  40
  41 /* flags */
  42 #define I2C_HID_STARTED         (1 << 0)
  43 #define I2C_HID_RESET_PENDING   (1 << 1)
  44 #define I2C_HID_READ_PENDING    (1 << 2)
  45
  46 #define I2C_HID_PWR_ON          0x00
  47 #define I2C_HID_PWR_SLEEP       0x01
  48
  49 /* debug option */
  50 static bool debug;
  51 module_param(debug, bool, 0444);
  52 MODULE_PARM_DESC(debug, "print a lot of debug information");
  53
  54 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  55 do {                                                                      \
  56         if (debug)                                                        \
  57                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  58 } while (0)
  59
  60 struct i2c_hid_desc {
  61         __le16 wHIDDescLength;
  62         __le16 bcdVersion;
  63         __le16 wReportDescLength;
  64         __le16 wReportDescRegister;
  65         __le16 wInputRegister;
  66         __le16 wMaxInputLength;
  67         __le16 wOutputRegister;
  68         __le16 wMaxOutputLength;
  69         __le16 wCommandRegister;
  70         __le16 wDataRegister;
  71         __le16 wVendorID;
  72         __le16 wProductID;
  73         __le16 wVersionID;
  74         __le32 reserved;
  75 } __packed;
  76
  77 struct i2c_hid_cmd {
  78         unsigned int registerIndex;
  79         __u8 opcode;
  80         unsigned int length;
  81         bool wait;
  82 };
  83
  84 union command {
  85         u8 data[0];
  86         struct cmd {
  87                 __le16 reg;
  88                 __u8 reportTypeID;
  89                 __u8 opcode;
  90         } __packed c;
  91 };
  92
  93 #define I2C_HID_CMD(opcode_) \
  94         .opcode = opcode_, .length = 4, \
  95         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
  96
  97 /* fetch HID descriptor */
  98 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
  99 /* fetch report descriptors */
 100 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 101                 .registerIndex = offsetof(struct i2c_hid_desc,
 102                         wReportDescRegister),
 103                 .opcode = 0x00,
 104                 .length = 2 };
 105 /* commands */
 106 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 107                                                           .wait = true };
 108 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 109 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 110 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 111
 112 /*
 113  * These definitions are not used here, but are defined by the spec.
 114  * Keeping them here for documentation purposes.
 115  *
 116  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 117  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 118  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 119  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 120  */
 121
 122 static DEFINE_MUTEX(i2c_hid_open_mut);
 123
 124 /* The main device structure */
 125 struct i2c_hid {
 126         struct i2c_client       *client;        /* i2c client */
 127         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 128         union {
 129                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 130                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 131         };
 132         __le16                  wHIDDescRegister; /* location of the i2c
 133                                                    * register of the HID
 134                                                    * descriptor. */
 135         unsigned int            bufsize;        /* i2c buffer size */
 136         char                    *inbuf;         /* Input buffer */
 137         char                    *rawbuf;        /* Raw Input buffer */
 138         char                    *cmdbuf;        /* Command buffer */
 139         char                    *argsbuf;       /* Command arguments buffer */
 140
 141         unsigned long           flags;          /* device flags */
 142
 143         wait_queue_head_t       wait;           /* For waiting the interrupt */
 144
 145         struct i2c_hid_platform_data pdata;
 146 };
 147
 148 static int __i2c_hid_command(struct i2c_client *client,
 149                 const struct i2c_hid_cmd *command, u8 reportID,
 150                 u8 reportType, u8 *args, int args_len,
 151                 unsigned char *buf_recv, int data_len)
 152 {
 153         struct i2c_hid *ihid = i2c_get_clientdata(client);
 154         union command *cmd = (union command *)ihid->cmdbuf;
 155         int ret;
 156         struct i2c_msg msg[2];
 157         int msg_num = 1;
 158
 159         int length = command->length;
 160         bool wait = command->wait;
 161         unsigned int registerIndex = command->registerIndex;
 162
 163         /* special case for hid_descr_cmd */
 164         if (command == &hid_descr_cmd) {
 165                 cmd->c.reg = ihid->wHIDDescRegister;
 166         } else {
 167                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 168                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 169         }
 170
 171         if (length > 2) {
 172                 cmd->c.opcode = command->opcode;
 173                 cmd->c.reportTypeID = reportID | reportType << 4;
 174         }
 175
 176         memcpy(cmd->data + length, args, args_len);
 177         length += args_len;
 178
 179         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 180
 181         msg[0].addr = client->addr;
 182         msg[0].flags = client->flags & I2C_M_TEN;
 183         msg[0].len = length;
 184         msg[0].buf = cmd->data;
 185         if (data_len > 0) {
 186                 msg[1].addr = client->addr;
 187                 msg[1].flags = client->flags & I2C_M_TEN;
 188                 msg[1].flags |= I2C_M_RD;
 189                 msg[1].len = data_len;
 190                 msg[1].buf = buf_recv;
 191                 msg_num = 2;
 192                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 193         }
 194
 195         if (wait)
 196                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 197
 198         ret = i2c_transfer(client->adapter, msg, msg_num);
 199
 200         if (data_len > 0)
 201                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 202
 203         if (ret != msg_num)
 204                 return ret < 0 ? ret : -EIO;
 205
 206         ret = 0;
 207
 208         if (wait) {
 209                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 210                 if (!wait_event_timeout(ihid->wait,
 211                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 212                                 msecs_to_jiffies(5000)))
 213                         ret = -ENODATA;
 214                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 215         }
 216
 217         return ret;
 218 }
 219
 220 static int i2c_hid_command(struct i2c_client *client,
 221                 const struct i2c_hid_cmd *command,
 222                 unsigned char *buf_recv, int data_len)
 223 {
 224         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 225                                 buf_recv, data_len);
 226 }
 227
 228 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 229                 u8 reportID, unsigned char *buf_recv, int data_len)
 230 {
 231         struct i2c_hid *ihid = i2c_get_clientdata(client);
 232         u8 args[3];
 233         int ret;
 234         int args_len = 0;
 235         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 236
 237         i2c_hid_dbg(ihid, "%s\n", __func__);
 238
 239         if (reportID >= 0x0F) {
 240                 args[args_len++] = reportID;
 241                 reportID = 0x0F;
 242         }
 243
 244         args[args_len++] = readRegister & 0xFF;
 245         args[args_len++] = readRegister >> 8;
 246
 247         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 248                 reportType, args, args_len, buf_recv, data_len);
 249         if (ret) {
 250                 dev_err(&client->dev,
 251                         "failed to retrieve report from device.\n");
 252                 return ret;
 253         }
 254
 255         return 0;
 256 }
 257
 258 static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
 259                 u8 reportID, unsigned char *buf, size_t data_len)
 260 {
 261         struct i2c_hid *ihid = i2c_get_clientdata(client);
 262         u8 *args = ihid->argsbuf;
 263         int ret;
 264         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 265
 266         /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
 267         u16 size =      2                       /* size */ +
 268                         (reportID ? 1 : 0)      /* reportID */ +
 269                         data_len                /* buf */;
 270         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 271                         2                       /* dataRegister */ +
 272                         size                    /* args */;
 273         int index = 0;
 274
 275         i2c_hid_dbg(ihid, "%s\n", __func__);
 276
 277         if (reportID >= 0x0F) {
 278                 args[index++] = reportID;
 279                 reportID = 0x0F;
 280         }
 281
 282         args[index++] = dataRegister & 0xFF;
 283         args[index++] = dataRegister >> 8;
 284
 285         args[index++] = size & 0xFF;
 286         args[index++] = size >> 8;
 287
 288         if (reportID)
 289                 args[index++] = reportID;
 290
 291         memcpy(&args[index], buf, data_len);
 292
 293         ret = __i2c_hid_command(client, &hid_set_report_cmd, reportID,
 294                 reportType, args, args_len, NULL, 0);
 295         if (ret) {
 296                 dev_err(&client->dev, "failed to set a report to device.\n");
 297                 return ret;
 298         }
 299
 300         return data_len;
 301 }
 302
 303 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 304 {
 305         struct i2c_hid *ihid = i2c_get_clientdata(client);
 306         int ret;
 307
 308         i2c_hid_dbg(ihid, "%s\n", __func__);
 309
 310         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 311                 0, NULL, 0, NULL, 0);
 312         if (ret)
 313                 dev_err(&client->dev, "failed to change power setting.\n");
 314
 315         return ret;
 316 }
 317
 318 static int i2c_hid_hwreset(struct i2c_client *client)
 319 {
 320         struct i2c_hid *ihid = i2c_get_clientdata(client);
 321         int ret;
 322
 323         i2c_hid_dbg(ihid, "%s\n", __func__);
 324
 325         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 326         if (ret)
 327                 return ret;
 328
 329         i2c_hid_dbg(ihid, "resetting...\n");
 330
 331         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 332         if (ret) {
 333                 dev_err(&client->dev, "failed to reset device.\n");
 334                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 335                 return ret;
 336         }
 337
 338         return 0;
 339 }
 340
 341 static void i2c_hid_get_input(struct i2c_hid *ihid)
 342 {
 343         int ret, ret_size;
 344         int size = ihid->bufsize;
 345
 346         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 347         if (ret != size) {
 348                 if (ret < 0)
 349                         return;
 350
 351                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 352                         __func__, ret, size);
 353                 return;
 354         }
 355
 356         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 357
 358         if (!ret_size) {
 359                 /* host or device initiated RESET completed */
 360                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 361                         wake_up(&ihid->wait);
 362                 return;
 363         }
 364
 365         if (ret_size > size) {
 366                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 367                         __func__, size, ret_size);
 368                 return;
 369         }
 370
 371         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 372
 373         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 374                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 375                                 ret_size - 2, 1);
 376
 377         return;
 378 }
 379
 380 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 381 {
 382         struct i2c_hid *ihid = dev_id;
 383
 384         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 385                 return IRQ_HANDLED;
 386
 387         i2c_hid_get_input(ihid);
 388
 389         return IRQ_HANDLED;
 390 }
 391
 392 static int i2c_hid_get_report_length(struct hid_report *report)
 393 {
 394         return ((report->size - 1) >> 3) + 1 +
 395                 report->device->report_enum[report->type].numbered + 2;
 396 }
 397
 398 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 399         size_t bufsize)
 400 {
 401         struct hid_device *hid = report->device;
 402         struct i2c_client *client = hid->driver_data;
 403         struct i2c_hid *ihid = i2c_get_clientdata(client);
 404         unsigned int size, ret_size;
 405
 406         size = i2c_hid_get_report_length(report);
 407         if (i2c_hid_get_report(client,
 408                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 409                         report->id, buffer, size))
 410                 return;
 411
 412         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);
 413
 414         ret_size = buffer[0] | (buffer[1] << 8);
 415
 416         if (ret_size != size) {
 417                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 418                         __func__, size, ret_size);
 419                 return;
 420         }
 421
 422         /* hid->driver_lock is held as we are in probe function,
 423          * we just need to setup the input fields, so using
 424          * hid_report_raw_event is safe. */
 425         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 426 }
 427
 428 /*
 429  * Initialize all reports
 430  */
 431 static void i2c_hid_init_reports(struct hid_device *hid)
 432 {
 433         struct hid_report *report;
 434         struct i2c_client *client = hid->driver_data;
 435         struct i2c_hid *ihid = i2c_get_clientdata(client);
 436         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 437
 438         if (!inbuf) {
 439                 dev_err(&client->dev, "can not retrieve initial reports\n");
 440                 return;
 441         }
 442
 443         list_for_each_entry(report,
 444                 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
 445                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 446
 447         list_for_each_entry(report,
 448                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 449                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 450
 451         kfree(inbuf);
 452 }
 453
 454 /*
 455  * Traverse the supplied list of reports and find the longest
 456  */
 457 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 458                 unsigned int *max)
 459 {
 460         struct hid_report *report;
 461         unsigned int size;
 462
 463         /* We should not rely on wMaxInputLength, as some devices may set it to
 464          * a wrong length. */
 465         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 466                 size = i2c_hid_get_report_length(report);
 467                 if (*max < size)
 468                         *max = size;
 469         }
 470 }
 471
 472 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 473 {
 474         kfree(ihid->inbuf);
 475         kfree(ihid->rawbuf);
 476         kfree(ihid->argsbuf);
 477         kfree(ihid->cmdbuf);
 478         ihid->inbuf = NULL;
 479         ihid->rawbuf = NULL;
 480         ihid->cmdbuf = NULL;
 481         ihid->argsbuf = NULL;
 482         ihid->bufsize = 0;
 483 }
 484
 485 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 486 {
 487         /* the worst case is computed from the set_report command with a
 488          * reportID > 15 and the maximum report length */
 489         int args_len = sizeof(__u8) + /* optional ReportID byte */
 490                        sizeof(__u16) + /* data register */
 491                        sizeof(__u16) + /* size of the report */
 492                        report_size; /* report */
 493
 494         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 495         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 496         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 497         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 498
 499         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 500                 i2c_hid_free_buffers(ihid);
 501                 return -ENOMEM;
 502         }
 503
 504         ihid->bufsize = report_size;
 505
 506         return 0;
 507 }
 508
 509 static int i2c_hid_get_raw_report(struct hid_device *hid,
 510                 unsigned char report_number, __u8 *buf, size_t count,
 511                 unsigned char report_type)
 512 {
 513         struct i2c_client *client = hid->driver_data;
 514         struct i2c_hid *ihid = i2c_get_clientdata(client);
 515         size_t ret_count, ask_count;
 516         int ret;
 517
 518         if (report_type == HID_OUTPUT_REPORT)
 519                 return -EINVAL;
 520
 521         /* +2 bytes to include the size of the reply in the query buffer */
 522         ask_count = min(count + 2, (size_t)ihid->bufsize);
 523
 524         ret = i2c_hid_get_report(client,
 525                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 526                         report_number, ihid->rawbuf, ask_count);
 527
 528         if (ret < 0)
 529                 return ret;
 530
 531         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 532
 533         if (ret_count <= 2)
 534                 return 0;
 535
 536         ret_count = min(ret_count, ask_count);
 537
 538         /* The query buffer contains the size, dropping it in the reply */
 539         count = min(count, ret_count - 2);
 540         memcpy(buf, ihid->rawbuf + 2, count);
 541
 542         return count;
 543 }
 544
 545 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 546                 size_t count, unsigned char report_type)
 547 {
 548         struct i2c_client *client = hid->driver_data;
 549         int report_id = buf[0];
 550         int ret;
 551
 552         if (report_type == HID_INPUT_REPORT)
 553                 return -EINVAL;
 554
 555         if (report_id) {
 556                 buf++;
 557                 count--;
 558         }
 559
 560         ret = i2c_hid_set_report(client,
 561                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 562                                 report_id, buf, count);
 563
 564         if (report_id && ret >= 0)
 565                 ret++; /* add report_id to the number of transfered bytes */
 566
 567         return ret;
 568 }
 569
 570 static void i2c_hid_request(struct hid_device *hid, struct hid_report *rep,
 571                 int reqtype)
 572 {
 573         struct i2c_client *client = hid->driver_data;
 574         char *buf;
 575         int ret;
 576         int len = i2c_hid_get_report_length(rep) - 2;
 577
 578         buf = kzalloc(len, GFP_KERNEL);
 579         if (!buf)
 580                 return;
 581
 582         switch (reqtype) {
 583         case HID_REQ_GET_REPORT:
 584                 ret = i2c_hid_get_raw_report(hid, rep->id, buf, len, rep->type);
 585                 if (ret < 0)
 586                         dev_err(&client->dev, "%s: unable to get report: %d\n",
 587                                 __func__, ret);
 588                 else
 589                         hid_input_report(hid, rep->type, buf, ret, 0);
 590                 break;
 591         case HID_REQ_SET_REPORT:
 592                 hid_output_report(rep, buf);
 593                 i2c_hid_output_raw_report(hid, buf, len, rep->type);
 594                 break;
 595         }
 596
 597         kfree(buf);
 598 }
 599
 600 static int i2c_hid_parse(struct hid_device *hid)
 601 {
 602         struct i2c_client *client = hid->driver_data;
 603         struct i2c_hid *ihid = i2c_get_clientdata(client);
 604         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 605         unsigned int rsize;
 606         char *rdesc;
 607         int ret;
 608         int tries = 3;
 609
 610         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 611
 612         rsize = le16_to_cpu(hdesc->wReportDescLength);
 613         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 614                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 615                 return -EINVAL;
 616         }
 617
 618         do {
 619                 ret = i2c_hid_hwreset(client);
 620                 if (ret)
 621                         msleep(1000);
 622         } while (tries-- > 0 && ret);
 623
 624         if (ret)
 625                 return ret;
 626
 627         rdesc = kzalloc(rsize, GFP_KERNEL);
 628
 629         if (!rdesc) {
 630                 dbg_hid("couldn't allocate rdesc memory\n");
 631                 return -ENOMEM;
 632         }
 633
 634         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 635
 636         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 637         if (ret) {
 638                 hid_err(hid, "reading report descriptor failed\n");
 639                 kfree(rdesc);
 640                 return -EIO;
 641         }
 642
 643         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 644
 645         ret = hid_parse_report(hid, rdesc, rsize);
 646         kfree(rdesc);
 647         if (ret) {
 648                 dbg_hid("parsing report descriptor failed\n");
 649                 return ret;
 650         }
 651
 652         return 0;
 653 }
 654
 655 static int i2c_hid_start(struct hid_device *hid)
 656 {
 657         struct i2c_client *client = hid->driver_data;
 658         struct i2c_hid *ihid = i2c_get_clientdata(client);
 659         int ret;
 660         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 661
 662         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 663         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 664         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 665
 666         if (bufsize > ihid->bufsize) {
 667                 i2c_hid_free_buffers(ihid);
 668
 669                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 670
 671                 if (ret)
 672                         return ret;
 673         }
 674
 675         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 676                 i2c_hid_init_reports(hid);
 677
 678         return 0;
 679 }
 680
 681 static void i2c_hid_stop(struct hid_device *hid)
 682 {
 683         struct i2c_client *client = hid->driver_data;
 684         struct i2c_hid *ihid = i2c_get_clientdata(client);
 685
 686         hid->claimed = 0;
 687
 688         i2c_hid_free_buffers(ihid);
 689 }
 690
 691 static int i2c_hid_open(struct hid_device *hid)
 692 {
 693         struct i2c_client *client = hid->driver_data;
 694         struct i2c_hid *ihid = i2c_get_clientdata(client);
 695         int ret = 0;
 696
 697         mutex_lock(&i2c_hid_open_mut);
 698         if (!hid->open++) {
 699                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 700                 if (ret) {
 701                         hid->open--;
 702                         goto done;
 703                 }
 704                 set_bit(I2C_HID_STARTED, &ihid->flags);
 705         }
 706 done:
 707         mutex_unlock(&i2c_hid_open_mut);
 708         return ret;
 709 }
 710
 711 static void i2c_hid_close(struct hid_device *hid)
 712 {
 713         struct i2c_client *client = hid->driver_data;
 714         struct i2c_hid *ihid = i2c_get_clientdata(client);
 715
 716         /* protecting hid->open to make sure we don't restart
 717          * data acquistion due to a resumption we no longer
 718          * care about
 719          */
 720         mutex_lock(&i2c_hid_open_mut);
 721         if (!--hid->open) {
 722                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 723
 724                 /* Save some power */
 725                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 726         }
 727         mutex_unlock(&i2c_hid_open_mut);
 728 }
 729
 730 static int i2c_hid_power(struct hid_device *hid, int lvl)
 731 {
 732         struct i2c_client *client = hid->driver_data;
 733         struct i2c_hid *ihid = i2c_get_clientdata(client);
 734         int ret = 0;
 735
 736         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 737
 738         switch (lvl) {
 739         case PM_HINT_FULLON:
 740                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 741                 break;
 742         case PM_HINT_NORMAL:
 743                 ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 744                 break;
 745         }
 746         return ret;
 747 }
 748
 749 static int i2c_hid_hidinput_input_event(struct input_dev *dev,
 750                 unsigned int type, unsigned int code, int value)
 751 {
 752         struct hid_device *hid = input_get_drvdata(dev);
 753         struct hid_field *field;
 754         int offset;
 755
 756         if (type == EV_FF)
 757                 return input_ff_event(dev, type, code, value);
 758
 759         if (type != EV_LED)
 760                 return -1;
 761
 762         offset = hidinput_find_field(hid, type, code, &field);
 763
 764         if (offset == -1) {
 765                 hid_warn(dev, "event field not found\n");
 766                 return -1;
 767         }
 768
 769         return hid_set_field(field, offset, value);
 770 }
 771
 772 static struct hid_ll_driver i2c_hid_ll_driver = {
 773         .parse = i2c_hid_parse,
 774         .start = i2c_hid_start,
 775         .stop = i2c_hid_stop,
 776         .open = i2c_hid_open,
 777         .close = i2c_hid_close,
 778         .power = i2c_hid_power,
 779         .request = i2c_hid_request,
 780         .hidinput_input_event = i2c_hid_hidinput_input_event,
 781 };
 782
 783 static int i2c_hid_init_irq(struct i2c_client *client)
 784 {
 785         struct i2c_hid *ihid = i2c_get_clientdata(client);
 786         int ret;
 787
 788         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 789
 790         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 791                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 792                         client->name, ihid);
 793         if (ret < 0) {
 794                 dev_warn(&client->dev,
 795                         "Could not register for %s interrupt, irq = %d,"
 796                         " ret = %d\n",
 797                         client->name, client->irq, ret);
 798
 799                 return ret;
 800         }
 801
 802         return 0;
 803 }
 804
 805 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 806 {
 807         struct i2c_client *client = ihid->client;
 808         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 809         unsigned int dsize;
 810         int ret;
 811
 812         /* Fetch the length of HID description, retrieve the 4 first bytes:
 813          * bytes 0-1 -> length
 814          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 815         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
 816
 817         i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %*ph\n",
 818                         __func__, 4, ihid->hdesc_buffer);
 819
 820         if (ret) {
 821                 dev_err(&client->dev,
 822                         "unable to fetch the size of HID descriptor (ret=%d)\n",
 823                         ret);
 824                 return -ENODEV;
 825         }
 826
 827         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 828         /*
 829          * the size of the HID descriptor should at least contain
 830          * its size and the bcdVersion (4 bytes), and should not be greater
 831          * than sizeof(struct i2c_hid_desc) as we directly fill this struct
 832          * through i2c_hid_command.
 833          */
 834         if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
 835                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 836                         dsize);
 837                 return -ENODEV;
 838         }
 839
 840         /* check bcdVersion == 1.0 */
 841         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 842                 dev_err(&client->dev,
 843                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 844                         le16_to_cpu(hdesc->bcdVersion));
 845                 return -ENODEV;
 846         }
 847
 848         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 849
 850         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 851                                 dsize);
 852         if (ret) {
 853                 dev_err(&client->dev, "hid_descr_cmd Fail\n");
 854                 return -ENODEV;
 855         }
 856
 857         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 858
 859         return 0;
 860 }
 861
 862 #ifdef CONFIG_ACPI
 863 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 864                 struct i2c_hid_platform_data *pdata)
 865 {
 866         static u8 i2c_hid_guid[] = {
 867                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 868                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 869         };
 870         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
 871         union acpi_object params[4], *obj;
 872         struct acpi_object_list input;
 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         input.count = ARRAY_SIZE(params);
 881         input.pointer = params;
 882
 883         params[0].type = ACPI_TYPE_BUFFER;
 884         params[0].buffer.length = sizeof(i2c_hid_guid);
 885         params[0].buffer.pointer = i2c_hid_guid;
 886         params[1].type = ACPI_TYPE_INTEGER;
 887         params[1].integer.value = 1;
 888         params[2].type = ACPI_TYPE_INTEGER;
 889         params[2].integer.value = 1; /* HID function */
 890         params[3].type = ACPI_TYPE_INTEGER;
 891         params[3].integer.value = 0;
 892
 893         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
 894                 dev_err(&client->dev, "device _DSM execution failed\n");
 895                 return -ENODEV;
 896         }
 897
 898         obj = (union acpi_object *)buf.pointer;
 899         if (obj->type != ACPI_TYPE_INTEGER) {
 900                 dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
 901                         obj->type);
 902                 kfree(buf.pointer);
 903                 return -EINVAL;
 904         }
 905
 906         pdata->hid_descriptor_address = obj->integer.value;
 907
 908         kfree(buf.pointer);
 909         return 0;
 910 }
 911
 912 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 913         {"ACPI0C50", 0 },
 914         {"PNP0C50", 0 },
 915         { },
 916 };
 917 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 918 #else
 919 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 920                 struct i2c_hid_platform_data *pdata)
 921 {
 922         return -ENODEV;
 923 }
 924 #endif
 925
 926 static int i2c_hid_probe(struct i2c_client *client,
 927                          const struct i2c_device_id *dev_id)
 928 {
 929         int ret;
 930         struct i2c_hid *ihid;
 931         struct hid_device *hid;
 932         __u16 hidRegister;
 933         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 934
 935         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 936
 937         if (!client->irq) {
 938                 dev_err(&client->dev,
 939                         "HID over i2c has not been provided an Int IRQ\n");
 940                 return -EINVAL;
 941         }
 942
 943         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 944         if (!ihid)
 945                 return -ENOMEM;
 946
 947         if (!platform_data) {
 948                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 949                 if (ret) {
 950                         dev_err(&client->dev,
 951                                 "HID register address not provided\n");
 952                         goto err;
 953                 }
 954         } else {
 955                 ihid->pdata = *platform_data;
 956         }
 957
 958         i2c_set_clientdata(client, ihid);
 959
 960         ihid->client = client;
 961
 962         hidRegister = ihid->pdata.hid_descriptor_address;
 963         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
 964
 965         init_waitqueue_head(&ihid->wait);
 966
 967         /* we need to allocate the command buffer without knowing the maximum
 968          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 969          * real computation later. */
 970         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 971         if (ret < 0)
 972                 goto err;
 973
 974         ret = i2c_hid_fetch_hid_descriptor(ihid);
 975         if (ret < 0)
 976                 goto err;
 977
 978         ret = i2c_hid_init_irq(client);
 979         if (ret < 0)
 980                 goto err;
 981
 982         hid = hid_allocate_device();
 983         if (IS_ERR(hid)) {
 984                 ret = PTR_ERR(hid);
 985                 goto err_irq;
 986         }
 987
 988         ihid->hid = hid;
 989
 990         hid->driver_data = client;
 991         hid->ll_driver = &i2c_hid_ll_driver;
 992         hid->hid_get_raw_report = i2c_hid_get_raw_report;
 993         hid->hid_output_raw_report = i2c_hid_output_raw_report;
 994         hid->dev.parent = &client->dev;
 995         ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
 996         hid->bus = BUS_I2C;
 997         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 998         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 999         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1000
1001         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1002                  client->name, hid->vendor, hid->product);
1003
1004         ret = hid_add_device(hid);
1005         if (ret) {
1006                 if (ret != -ENODEV)
1007                         hid_err(client, "can't add hid device: %d\n", ret);
1008                 goto err_mem_free;
1009         }
1010
1011         return 0;
1012
1013 err_mem_free:
1014         hid_destroy_device(hid);
1015
1016 err_irq:
1017         free_irq(client->irq, ihid);
1018
1019 err:
1020         i2c_hid_free_buffers(ihid);
1021         kfree(ihid);
1022         return ret;
1023 }
1024
1025 static int i2c_hid_remove(struct i2c_client *client)
1026 {
1027         struct i2c_hid *ihid = i2c_get_clientdata(client);
1028         struct hid_device *hid;
1029
1030         hid = ihid->hid;
1031         hid_destroy_device(hid);
1032
1033         free_irq(client->irq, ihid);
1034
1035         if (ihid->bufsize)
1036                 i2c_hid_free_buffers(ihid);
1037
1038         kfree(ihid);
1039
1040         return 0;
1041 }
1042
1043 #ifdef CONFIG_PM_SLEEP
1044 static int i2c_hid_suspend(struct device *dev)
1045 {
1046         struct i2c_client *client = to_i2c_client(dev);
1047
1048         if (device_may_wakeup(&client->dev))
1049                 enable_irq_wake(client->irq);
1050
1051         /* Save some power */
1052         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1053
1054         return 0;
1055 }
1056
1057 static int i2c_hid_resume(struct device *dev)
1058 {
1059         int ret;
1060         struct i2c_client *client = to_i2c_client(dev);
1061
1062         ret = i2c_hid_hwreset(client);
1063         if (ret)
1064                 return ret;
1065
1066         if (device_may_wakeup(&client->dev))
1067                 disable_irq_wake(client->irq);
1068
1069         return 0;
1070 }
1071 #endif
1072
1073 static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);
1074
1075 static const struct i2c_device_id i2c_hid_id_table[] = {
1076         { "hid", 0 },
1077         { },
1078 };
1079 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1080
1081
1082 static struct i2c_driver i2c_hid_driver = {
1083         .driver = {
1084                 .name   = "i2c_hid",
1085                 .owner  = THIS_MODULE,
1086                 .pm     = &i2c_hid_pm,
1087                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1088         },
1089
1090         .probe          = i2c_hid_probe,
1091         .remove         = i2c_hid_remove,
1092
1093         .id_table       = i2c_hid_id_table,
1094 };
1095
1096 module_i2c_driver(i2c_hid_driver);
1097
1098 MODULE_DESCRIPTION("HID over I2C core driver");
1099 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1100 MODULE_LICENSE("GPL");