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
 286         /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
 287         u16 size =      2                       /* size */ +
 288                         (reportID ? 1 : 0)      /* reportID */ +
 289                         data_len                /* buf */;
 290         int args_len =  (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 291                         2                       /* dataRegister */ +
 292                         size                    /* args */;
 293         int index = 0;
 294
 295         i2c_hid_dbg(ihid, "%s\n", __func__);
 296
 297         if (!use_data && maxOutputLength == 0)
 298                 return -ENOSYS;
 299
 300         if (reportID >= 0x0F) {
 301                 args[index++] = reportID;
 302                 reportID = 0x0F;
 303         }
 304
 305         /*
 306          * use the data register for feature reports or if the device does not
 307          * support the output register
 308          */
 309         if (use_data) {
 310                 args[index++] = dataRegister & 0xFF;
 311                 args[index++] = dataRegister >> 8;
 312                 hidcmd = &hid_set_report_cmd;
 313         } else {
 314                 args[index++] = outputRegister & 0xFF;
 315                 args[index++] = outputRegister >> 8;
 316                 hidcmd = &hid_no_cmd;
 317         }
 318
 319         args[index++] = size & 0xFF;
 320         args[index++] = size >> 8;
 321
 322         if (reportID)
 323                 args[index++] = reportID;
 324
 325         memcpy(&args[index], buf, data_len);
 326
 327         ret = __i2c_hid_command(client, hidcmd, reportID,
 328                 reportType, args, args_len, NULL, 0);
 329         if (ret) {
 330                 dev_err(&client->dev, "failed to set a report to device.\n");
 331                 return ret;
 332         }
 333
 334         return data_len;
 335 }
 336
 337 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 338 {
 339         struct i2c_hid *ihid = i2c_get_clientdata(client);
 340         int ret;
 341
 342         i2c_hid_dbg(ihid, "%s\n", __func__);
 343
 344         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 345                 0, NULL, 0, NULL, 0);
 346         if (ret)
 347                 dev_err(&client->dev, "failed to change power setting.\n");
 348
 349         return ret;
 350 }
 351
 352 static int i2c_hid_hwreset(struct i2c_client *client)
 353 {
 354         struct i2c_hid *ihid = i2c_get_clientdata(client);
 355         int ret;
 356
 357         i2c_hid_dbg(ihid, "%s\n", __func__);
 358
 359         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 360         if (ret)
 361                 return ret;
 362
 363         i2c_hid_dbg(ihid, "resetting...\n");
 364
 365         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 366         if (ret) {
 367                 dev_err(&client->dev, "failed to reset device.\n");
 368                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 369                 return ret;
 370         }
 371
 372         return 0;
 373 }
 374
 375 static void i2c_hid_get_input(struct i2c_hid *ihid)
 376 {
 377         int ret, ret_size;
 378         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 379
 380         if (size > ihid->bufsize)
 381                 size = ihid->bufsize;
 382
 383         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 384         if (ret != size) {
 385                 if (ret < 0)
 386                         return;
 387
 388                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 389                         __func__, ret, size);
 390                 return;
 391         }
 392
 393         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 394
 395         if (!ret_size) {
 396                 /* host or device initiated RESET completed */
 397                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 398                         wake_up(&ihid->wait);
 399                 return;
 400         }
 401
 402         if (ret_size > size) {
 403                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 404                         __func__, size, ret_size);
 405                 return;
 406         }
 407
 408         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 409
 410         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 411                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 412                                 ret_size - 2, 1);
 413
 414         return;
 415 }
 416
 417 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 418 {
 419         struct i2c_hid *ihid = dev_id;
 420
 421         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 422                 return IRQ_HANDLED;
 423
 424         i2c_hid_get_input(ihid);
 425
 426         return IRQ_HANDLED;
 427 }
 428
 429 static int i2c_hid_get_report_length(struct hid_report *report)
 430 {
 431         return ((report->size - 1) >> 3) + 1 +
 432                 report->device->report_enum[report->type].numbered + 2;
 433 }
 434
 435 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 436         size_t bufsize)
 437 {
 438         struct hid_device *hid = report->device;
 439         struct i2c_client *client = hid->driver_data;
 440         struct i2c_hid *ihid = i2c_get_clientdata(client);
 441         unsigned int size, ret_size;
 442
 443         size = i2c_hid_get_report_length(report);
 444         if (i2c_hid_get_report(client,
 445                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 446                         report->id, buffer, size))
 447                 return;
 448
 449         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
 450
 451         ret_size = buffer[0] | (buffer[1] << 8);
 452
 453         if (ret_size != size) {
 454                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 455                         __func__, size, ret_size);
 456                 return;
 457         }
 458
 459         /* hid->driver_lock is held as we are in probe function,
 460          * we just need to setup the input fields, so using
 461          * hid_report_raw_event is safe. */
 462         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 463 }
 464
 465 /*
 466  * Initialize all reports
 467  */
 468 static void i2c_hid_init_reports(struct hid_device *hid)
 469 {
 470         struct hid_report *report;
 471         struct i2c_client *client = hid->driver_data;
 472         struct i2c_hid *ihid = i2c_get_clientdata(client);
 473         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 474
 475         if (!inbuf) {
 476                 dev_err(&client->dev, "can not retrieve initial reports\n");
 477                 return;
 478         }
 479
 480         /*
 481          * The device must be powered on while we fetch initial reports
 482          * from it.
 483          */
 484         pm_runtime_get_sync(&client->dev);
 485
 486         list_for_each_entry(report,
 487                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 488                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 489
 490         pm_runtime_put(&client->dev);
 491
 492         kfree(inbuf);
 493 }
 494
 495 /*
 496  * Traverse the supplied list of reports and find the longest
 497  */
 498 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 499                 unsigned int *max)
 500 {
 501         struct hid_report *report;
 502         unsigned int size;
 503
 504         /* We should not rely on wMaxInputLength, as some devices may set it to
 505          * a wrong length. */
 506         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 507                 size = i2c_hid_get_report_length(report);
 508                 if (*max < size)
 509                         *max = size;
 510         }
 511 }
 512
 513 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 514 {
 515         kfree(ihid->inbuf);
 516         kfree(ihid->rawbuf);
 517         kfree(ihid->argsbuf);
 518         kfree(ihid->cmdbuf);
 519         ihid->inbuf = NULL;
 520         ihid->rawbuf = NULL;
 521         ihid->cmdbuf = NULL;
 522         ihid->argsbuf = NULL;
 523         ihid->bufsize = 0;
 524 }
 525
 526 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 527 {
 528         /* the worst case is computed from the set_report command with a
 529          * reportID > 15 and the maximum report length */
 530         int args_len = sizeof(__u8) + /* optional ReportID byte */
 531                        sizeof(__u16) + /* data register */
 532                        sizeof(__u16) + /* size of the report */
 533                        report_size; /* report */
 534
 535         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 536         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 537         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 538         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 539
 540         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 541                 i2c_hid_free_buffers(ihid);
 542                 return -ENOMEM;
 543         }
 544
 545         ihid->bufsize = report_size;
 546
 547         return 0;
 548 }
 549
 550 static int i2c_hid_get_raw_report(struct hid_device *hid,
 551                 unsigned char report_number, __u8 *buf, size_t count,
 552                 unsigned char report_type)
 553 {
 554         struct i2c_client *client = hid->driver_data;
 555         struct i2c_hid *ihid = i2c_get_clientdata(client);
 556         size_t ret_count, ask_count;
 557         int ret;
 558
 559         if (report_type == HID_OUTPUT_REPORT)
 560                 return -EINVAL;
 561
 562         /* +2 bytes to include the size of the reply in the query buffer */
 563         ask_count = min(count + 2, (size_t)ihid->bufsize);
 564
 565         ret = i2c_hid_get_report(client,
 566                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 567                         report_number, ihid->rawbuf, ask_count);
 568
 569         if (ret < 0)
 570                 return ret;
 571
 572         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 573
 574         if (ret_count <= 2)
 575                 return 0;
 576
 577         ret_count = min(ret_count, ask_count);
 578
 579         /* The query buffer contains the size, dropping it in the reply */
 580         count = min(count, ret_count - 2);
 581         memcpy(buf, ihid->rawbuf + 2, count);
 582
 583         return count;
 584 }
 585
 586 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 587                 size_t count, unsigned char report_type, bool use_data)
 588 {
 589         struct i2c_client *client = hid->driver_data;
 590         int report_id = buf[0];
 591         int ret;
 592
 593         if (report_type == HID_INPUT_REPORT)
 594                 return -EINVAL;
 595
 596         if (report_id) {
 597                 buf++;
 598                 count--;
 599         }
 600
 601         ret = i2c_hid_set_or_send_report(client,
 602                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 603                                 report_id, buf, count, use_data);
 604
 605         if (report_id && ret >= 0)
 606                 ret++; /* add report_id to the number of transfered bytes */
 607
 608         return ret;
 609 }
 610
 611 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 612                 size_t count)
 613 {
 614         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 615                         false);
 616 }
 617
 618 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 619                                __u8 *buf, size_t len, unsigned char rtype,
 620                                int reqtype)
 621 {
 622         switch (reqtype) {
 623         case HID_REQ_GET_REPORT:
 624                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 625         case HID_REQ_SET_REPORT:
 626                 if (buf[0] != reportnum)
 627                         return -EINVAL;
 628                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 629         default:
 630                 return -EIO;
 631         }
 632 }
 633
 634 static int i2c_hid_parse(struct hid_device *hid)
 635 {
 636         struct i2c_client *client = hid->driver_data;
 637         struct i2c_hid *ihid = i2c_get_clientdata(client);
 638         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 639         unsigned int rsize;
 640         char *rdesc;
 641         int ret;
 642         int tries = 3;
 643
 644         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 645
 646         rsize = le16_to_cpu(hdesc->wReportDescLength);
 647         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 648                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 649                 return -EINVAL;
 650         }
 651
 652         do {
 653                 ret = i2c_hid_hwreset(client);
 654                 if (ret)
 655                         msleep(1000);
 656         } while (tries-- > 0 && ret);
 657
 658         if (ret)
 659                 return ret;
 660
 661         rdesc = kzalloc(rsize, GFP_KERNEL);
 662
 663         if (!rdesc) {
 664                 dbg_hid("couldn't allocate rdesc memory\n");
 665                 return -ENOMEM;
 666         }
 667
 668         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 669
 670         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 671         if (ret) {
 672                 hid_err(hid, "reading report descriptor failed\n");
 673                 kfree(rdesc);
 674                 return -EIO;
 675         }
 676
 677         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 678
 679         ret = hid_parse_report(hid, rdesc, rsize);
 680         kfree(rdesc);
 681         if (ret) {
 682                 dbg_hid("parsing report descriptor failed\n");
 683                 return ret;
 684         }
 685
 686         return 0;
 687 }
 688
 689 static int i2c_hid_start(struct hid_device *hid)
 690 {
 691         struct i2c_client *client = hid->driver_data;
 692         struct i2c_hid *ihid = i2c_get_clientdata(client);
 693         int ret;
 694         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 695
 696         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 697         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 698         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 699
 700         if (bufsize > ihid->bufsize) {
 701                 i2c_hid_free_buffers(ihid);
 702
 703                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 704
 705                 if (ret)
 706                         return ret;
 707         }
 708
 709         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 710                 i2c_hid_init_reports(hid);
 711
 712         return 0;
 713 }
 714
 715 static void i2c_hid_stop(struct hid_device *hid)
 716 {
 717         hid->claimed = 0;
 718 }
 719
 720 static int i2c_hid_open(struct hid_device *hid)
 721 {
 722         struct i2c_client *client = hid->driver_data;
 723         struct i2c_hid *ihid = i2c_get_clientdata(client);
 724         int ret = 0;
 725
 726         mutex_lock(&i2c_hid_open_mut);
 727         if (!hid->open++) {
 728                 ret = pm_runtime_get_sync(&client->dev);
 729                 if (ret < 0) {
 730                         hid->open--;
 731                         goto done;
 732                 }
 733                 set_bit(I2C_HID_STARTED, &ihid->flags);
 734         }
 735 done:
 736         mutex_unlock(&i2c_hid_open_mut);
 737         return ret < 0 ? ret : 0;
 738 }
 739
 740 static void i2c_hid_close(struct hid_device *hid)
 741 {
 742         struct i2c_client *client = hid->driver_data;
 743         struct i2c_hid *ihid = i2c_get_clientdata(client);
 744
 745         /* protecting hid->open to make sure we don't restart
 746          * data acquistion due to a resumption we no longer
 747          * care about
 748          */
 749         mutex_lock(&i2c_hid_open_mut);
 750         if (!--hid->open) {
 751                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 752
 753                 /* Save some power */
 754                 pm_runtime_put(&client->dev);
 755         }
 756         mutex_unlock(&i2c_hid_open_mut);
 757 }
 758
 759 static int i2c_hid_power(struct hid_device *hid, int lvl)
 760 {
 761         struct i2c_client *client = hid->driver_data;
 762         struct i2c_hid *ihid = i2c_get_clientdata(client);
 763
 764         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 765
 766         switch (lvl) {
 767         case PM_HINT_FULLON:
 768                 pm_runtime_get_sync(&client->dev);
 769                 break;
 770         case PM_HINT_NORMAL:
 771                 pm_runtime_put(&client->dev);
 772                 break;
 773         }
 774         return 0;
 775 }
 776
 777 static struct hid_ll_driver i2c_hid_ll_driver = {
 778         .parse = i2c_hid_parse,
 779         .start = i2c_hid_start,
 780         .stop = i2c_hid_stop,
 781         .open = i2c_hid_open,
 782         .close = i2c_hid_close,
 783         .power = i2c_hid_power,
 784         .output_report = i2c_hid_output_report,
 785         .raw_request = i2c_hid_raw_request,
 786 };
 787
 788 static int i2c_hid_init_irq(struct i2c_client *client)
 789 {
 790         struct i2c_hid *ihid = i2c_get_clientdata(client);
 791         int ret;
 792
 793         dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
 794
 795         ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
 796                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 797                         client->name, ihid);
 798         if (ret < 0) {
 799                 dev_warn(&client->dev,
 800                         "Could not register for %s interrupt, irq = %d,"
 801                         " ret = %d\n",
 802                         client->name, ihid->irq, ret);
 803
 804                 return ret;
 805         }
 806
 807         return 0;
 808 }
 809
 810 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 811 {
 812         struct i2c_client *client = ihid->client;
 813         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 814         unsigned int dsize;
 815         int ret;
 816
 817         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 818         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 819         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 820                                 sizeof(struct i2c_hid_desc));
 821         if (ret) {
 822                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 823                 return -ENODEV;
 824         }
 825
 826         /* Validate the length of HID descriptor, the 4 first bytes:
 827          * bytes 0-1 -> length
 828          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 829         /* check bcdVersion == 1.0 */
 830         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 831                 dev_err(&client->dev,
 832                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 833                         le16_to_cpu(hdesc->bcdVersion));
 834                 return -ENODEV;
 835         }
 836
 837         /* Descriptor length should be 30 bytes as per the specification */
 838         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 839         if (dsize != sizeof(struct i2c_hid_desc)) {
 840                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 841                         dsize);
 842                 return -ENODEV;
 843         }
 844         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 845         return 0;
 846 }
 847
 848 #ifdef CONFIG_ACPI
 849
 850 /* Default GPIO mapping */
 851 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
 852 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
 853         { "gpios", &i2c_hid_irq_gpio, 1 },
 854         { },
 855 };
 856
 857 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 858                 struct i2c_hid_platform_data *pdata)
 859 {
 860         static u8 i2c_hid_guid[] = {
 861                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 862                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 863         };
 864         union acpi_object *obj;
 865         struct acpi_device *adev;
 866         acpi_handle handle;
 867         int ret;
 868
 869         handle = ACPI_HANDLE(&client->dev);
 870         if (!handle || acpi_bus_get_device(handle, &adev))
 871                 return -ENODEV;
 872
 873         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 874                                       ACPI_TYPE_INTEGER);
 875         if (!obj) {
 876                 dev_err(&client->dev, "device _DSM execution failed\n");
 877                 return -ENODEV;
 878         }
 879
 880         pdata->hid_descriptor_address = obj->integer.value;
 881         ACPI_FREE(obj);
 882
 883         /* GPIOs are optional */
 884         ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
 885         return ret < 0 && ret != -ENXIO ? ret : 0;
 886 }
 887
 888 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 889         {"ACPI0C50", 0 },
 890         {"PNP0C50", 0 },
 891         { },
 892 };
 893 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 894 #else
 895 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 896                 struct i2c_hid_platform_data *pdata)
 897 {
 898         return -ENODEV;
 899 }
 900 #endif
 901
 902 #ifdef CONFIG_OF
 903 static int i2c_hid_of_probe(struct i2c_client *client,
 904                 struct i2c_hid_platform_data *pdata)
 905 {
 906         struct device *dev = &client->dev;
 907         u32 val;
 908         int ret;
 909
 910         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 911         if (ret) {
 912                 dev_err(&client->dev, "HID register address not provided\n");
 913                 return -ENODEV;
 914         }
 915         if (val >> 16) {
 916                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 917                         val);
 918                 return -EINVAL;
 919         }
 920         pdata->hid_descriptor_address = val;
 921
 922         return 0;
 923 }
 924
 925 static const struct of_device_id i2c_hid_of_match[] = {
 926         { .compatible = "hid-over-i2c" },
 927         {},
 928 };
 929 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 930 #else
 931 static inline int i2c_hid_of_probe(struct i2c_client *client,
 932                 struct i2c_hid_platform_data *pdata)
 933 {
 934         return -ENODEV;
 935 }
 936 #endif
 937
 938 static int i2c_hid_probe(struct i2c_client *client,
 939                          const struct i2c_device_id *dev_id)
 940 {
 941         int ret;
 942         struct i2c_hid *ihid;
 943         struct hid_device *hid;
 944         __u16 hidRegister;
 945         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 946
 947         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 948
 949         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 950         if (!ihid)
 951                 return -ENOMEM;
 952
 953         if (client->dev.of_node) {
 954                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 955                 if (ret)
 956                         goto err;
 957         } else if (!platform_data) {
 958                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 959                 if (ret) {
 960                         dev_err(&client->dev,
 961                                 "HID register address not provided\n");
 962                         goto err;
 963                 }
 964         } else {
 965                 ihid->pdata = *platform_data;
 966         }
 967
 968         if (client->irq > 0) {
 969                 ihid->irq = client->irq;
 970         } else if (ACPI_COMPANION(&client->dev)) {
 971                 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
 972                 if (IS_ERR(ihid->desc)) {
 973                         dev_err(&client->dev, "Failed to get GPIO interrupt\n");
 974                         return PTR_ERR(ihid->desc);
 975                 }
 976
 977                 ihid->irq = gpiod_to_irq(ihid->desc);
 978                 if (ihid->irq < 0) {
 979                         gpiod_put(ihid->desc);
 980                         dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
 981                         return ihid->irq;
 982                 }
 983         }
 984
 985         i2c_set_clientdata(client, ihid);
 986
 987         ihid->client = client;
 988
 989         hidRegister = ihid->pdata.hid_descriptor_address;
 990         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
 991
 992         init_waitqueue_head(&ihid->wait);
 993
 994         /* we need to allocate the command buffer without knowing the maximum
 995          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 996          * real computation later. */
 997         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 998         if (ret < 0)
 999                 goto err;
1000
1001         pm_runtime_get_noresume(&client->dev);
1002         pm_runtime_set_active(&client->dev);
1003         pm_runtime_enable(&client->dev);
1004
1005         ret = i2c_hid_fetch_hid_descriptor(ihid);
1006         if (ret < 0)
1007                 goto err_pm;
1008
1009         ret = i2c_hid_init_irq(client);
1010         if (ret < 0)
1011                 goto err_pm;
1012
1013         hid = hid_allocate_device();
1014         if (IS_ERR(hid)) {
1015                 ret = PTR_ERR(hid);
1016                 goto err_irq;
1017         }
1018
1019         ihid->hid = hid;
1020
1021         hid->driver_data = client;
1022         hid->ll_driver = &i2c_hid_ll_driver;
1023         hid->dev.parent = &client->dev;
1024         hid->bus = BUS_I2C;
1025         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1026         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1027         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1028
1029         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1030                  client->name, hid->vendor, hid->product);
1031         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1032
1033         ret = hid_add_device(hid);
1034         if (ret) {
1035                 if (ret != -ENODEV)
1036                         hid_err(client, "can't add hid device: %d\n", ret);
1037                 goto err_mem_free;
1038         }
1039
1040         pm_runtime_put(&client->dev);
1041         return 0;
1042
1043 err_mem_free:
1044         hid_destroy_device(hid);
1045
1046 err_irq:
1047         free_irq(ihid->irq, ihid);
1048
1049 err_pm:
1050         pm_runtime_put_noidle(&client->dev);
1051         pm_runtime_disable(&client->dev);
1052
1053 err:
1054         if (ihid->desc)
1055                 gpiod_put(ihid->desc);
1056
1057         i2c_hid_free_buffers(ihid);
1058         kfree(ihid);
1059         return ret;
1060 }
1061
1062 static int i2c_hid_remove(struct i2c_client *client)
1063 {
1064         struct i2c_hid *ihid = i2c_get_clientdata(client);
1065         struct hid_device *hid;
1066
1067         pm_runtime_get_sync(&client->dev);
1068         pm_runtime_disable(&client->dev);
1069         pm_runtime_set_suspended(&client->dev);
1070         pm_runtime_put_noidle(&client->dev);
1071
1072         hid = ihid->hid;
1073         hid_destroy_device(hid);
1074
1075         free_irq(ihid->irq, ihid);
1076
1077         if (ihid->bufsize)
1078                 i2c_hid_free_buffers(ihid);
1079
1080         if (ihid->desc)
1081                 gpiod_put(ihid->desc);
1082
1083         kfree(ihid);
1084
1085         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1086
1087         return 0;
1088 }
1089
1090 #ifdef CONFIG_PM_SLEEP
1091 static int i2c_hid_suspend(struct device *dev)
1092 {
1093         struct i2c_client *client = to_i2c_client(dev);
1094         struct i2c_hid *ihid = i2c_get_clientdata(client);
1095         struct hid_device *hid = ihid->hid;
1096         int ret = 0;
1097         int wake_status;
1098
1099         if (hid->driver && hid->driver->suspend)
1100                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1101
1102         disable_irq(ihid->irq);
1103         if (device_may_wakeup(&client->dev)) {
1104                 wake_status = enable_irq_wake(ihid->irq);
1105                 if (!wake_status)
1106                         ihid->irq_wake_enabled = true;
1107                 else
1108                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1109                                 wake_status);
1110         }
1111
1112         /* Save some power */
1113         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1114
1115         return ret;
1116 }
1117
1118 static int i2c_hid_resume(struct device *dev)
1119 {
1120         int ret;
1121         struct i2c_client *client = to_i2c_client(dev);
1122         struct i2c_hid *ihid = i2c_get_clientdata(client);
1123         struct hid_device *hid = ihid->hid;
1124         int wake_status;
1125
1126         enable_irq(ihid->irq);
1127         ret = i2c_hid_hwreset(client);
1128         if (ret)
1129                 return ret;
1130
1131         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1132                 wake_status = disable_irq_wake(ihid->irq);
1133                 if (!wake_status)
1134                         ihid->irq_wake_enabled = false;
1135                 else
1136                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1137                                 wake_status);
1138         }
1139
1140         if (hid->driver && hid->driver->reset_resume) {
1141                 ret = hid->driver->reset_resume(hid);
1142                 return ret;
1143         }
1144
1145         return 0;
1146 }
1147 #endif
1148
1149 #ifdef CONFIG_PM
1150 static int i2c_hid_runtime_suspend(struct device *dev)
1151 {
1152         struct i2c_client *client = to_i2c_client(dev);
1153         struct i2c_hid *ihid = i2c_get_clientdata(client);
1154
1155         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1156         disable_irq(ihid->irq);
1157         return 0;
1158 }
1159
1160 static int i2c_hid_runtime_resume(struct device *dev)
1161 {
1162         struct i2c_client *client = to_i2c_client(dev);
1163         struct i2c_hid *ihid = i2c_get_clientdata(client);
1164
1165         enable_irq(ihid->irq);
1166         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1167         return 0;
1168 }
1169 #endif
1170
1171 static const struct dev_pm_ops i2c_hid_pm = {
1172         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1173         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1174                            NULL)
1175 };
1176
1177 static const struct i2c_device_id i2c_hid_id_table[] = {
1178         { "hid", 0 },
1179         { },
1180 };
1181 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1182
1183
1184 static struct i2c_driver i2c_hid_driver = {
1185         .driver = {
1186                 .name   = "i2c_hid",
1187                 .owner  = THIS_MODULE,
1188                 .pm     = &i2c_hid_pm,
1189                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1190                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1191         },
1192
1193         .probe          = i2c_hid_probe,
1194         .remove         = i2c_hid_remove,
1195
1196         .id_table       = i2c_hid_id_table,
1197 };
1198
1199 module_i2c_driver(i2c_hid_driver);
1200
1201 MODULE_DESCRIPTION("HID over I2C core driver");
1202 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1203 MODULE_LICENSE("GPL");