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