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

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