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