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/irq.h>
  26 #include <linux/delay.h>
  27 #include <linux/slab.h>
  28 #include <linux/pm.h>
  29 #include <linux/pm_runtime.h>
  30 #include <linux/device.h>
  31 #include <linux/wait.h>
  32 #include <linux/err.h>
  33 #include <linux/string.h>
  34 #include <linux/list.h>
  35 #include <linux/jiffies.h>
  36 #include <linux/kernel.h>
  37 #include <linux/hid.h>
  38 #include <linux/mutex.h>
  39 #include <linux/acpi.h>
  40 #include <linux/of.h>
  41 #include <linux/regulator/consumer.h>
  42
  43 #include <linux/i2c/i2c-hid.h>
  44
  45 #include "../hid-ids.h"
  46
  47 /* quirks to control the device */
  48 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV        BIT(0)
  49
  50 /* flags */
  51 #define I2C_HID_STARTED         0
  52 #define I2C_HID_RESET_PENDING   1
  53 #define I2C_HID_READ_PENDING    2
  54
  55 #define I2C_HID_PWR_ON          0x00
  56 #define I2C_HID_PWR_SLEEP       0x01
  57
  58 /* debug option */
  59 static bool debug;
  60 module_param(debug, bool, 0444);
  61 MODULE_PARM_DESC(debug, "print a lot of debug information");
  62
  63 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  64 do {                                                                      \
  65         if (debug)                                                        \
  66                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  67 } while (0)
  68
  69 struct i2c_hid_desc {
  70         __le16 wHIDDescLength;
  71         __le16 bcdVersion;
  72         __le16 wReportDescLength;
  73         __le16 wReportDescRegister;
  74         __le16 wInputRegister;
  75         __le16 wMaxInputLength;
  76         __le16 wOutputRegister;
  77         __le16 wMaxOutputLength;
  78         __le16 wCommandRegister;
  79         __le16 wDataRegister;
  80         __le16 wVendorID;
  81         __le16 wProductID;
  82         __le16 wVersionID;
  83         __le32 reserved;
  84 } __packed;
  85
  86 struct i2c_hid_cmd {
  87         unsigned int registerIndex;
  88         __u8 opcode;
  89         unsigned int length;
  90         bool wait;
  91 };
  92
  93 union command {
  94         u8 data[0];
  95         struct cmd {
  96                 __le16 reg;
  97                 __u8 reportTypeID;
  98                 __u8 opcode;
  99         } __packed c;
 100 };
 101
 102 #define I2C_HID_CMD(opcode_) \
 103         .opcode = opcode_, .length = 4, \
 104         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 105
 106 /* fetch HID descriptor */
 107 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 108 /* fetch report descriptors */
 109 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 110                 .registerIndex = offsetof(struct i2c_hid_desc,
 111                         wReportDescRegister),
 112                 .opcode = 0x00,
 113                 .length = 2 };
 114 /* commands */
 115 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 116                                                           .wait = true };
 117 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 118 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 119 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 120 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 121
 122 /*
 123  * These definitions are not used here, but are defined by the spec.
 124  * Keeping them here for documentation purposes.
 125  *
 126  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 127  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 128  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 129  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 130  */
 131
 132 static DEFINE_MUTEX(i2c_hid_open_mut);
 133
 134 /* The main device structure */
 135 struct i2c_hid {
 136         struct i2c_client       *client;        /* i2c client */
 137         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 138         union {
 139                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 140                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 141         };
 142         __le16                  wHIDDescRegister; /* location of the i2c
 143                                                    * register of the HID
 144                                                    * descriptor. */
 145         unsigned int            bufsize;        /* i2c buffer size */
 146         char                    *inbuf;         /* Input buffer */
 147         char                    *rawbuf;        /* Raw Input buffer */
 148         char                    *cmdbuf;        /* Command buffer */
 149         char                    *argsbuf;       /* Command arguments buffer */
 150
 151         unsigned long           flags;          /* device flags */
 152         unsigned long           quirks;         /* Various quirks */
 153
 154         wait_queue_head_t       wait;           /* For waiting the interrupt */
 155
 156         struct i2c_hid_platform_data pdata;
 157
 158         bool                    irq_wake_enabled;
 159         struct mutex            reset_lock;
 160 };
 161
 162 static const struct i2c_hid_quirks {
 163         __u16 idVendor;
 164         __u16 idProduct;
 165         __u32 quirks;
 166 } i2c_hid_quirks[] = {
 167         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
 168                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 169         { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
 170                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 171         { 0, 0 }
 172 };
 173
 174 /*
 175  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 176  * @idVendor: the 16-bit vendor ID
 177  * @idProduct: the 16-bit product ID
 178  *
 179  * Returns: a u32 quirks value.
 180  */
 181 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 182 {
 183         u32 quirks = 0;
 184         int n;
 185
 186         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 187                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 188                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 189                      i2c_hid_quirks[n].idProduct == idProduct))
 190                         quirks = i2c_hid_quirks[n].quirks;
 191
 192         return quirks;
 193 }
 194
 195 static int __i2c_hid_command(struct i2c_client *client,
 196                 const struct i2c_hid_cmd *command, u8 reportID,
 197                 u8 reportType, u8 *args, int args_len,
 198                 unsigned char *buf_recv, int data_len)
 199 {
 200         struct i2c_hid *ihid = i2c_get_clientdata(client);
 201         union command *cmd = (union command *)ihid->cmdbuf;
 202         int ret;
 203         struct i2c_msg msg[2];
 204         int msg_num = 1;
 205
 206         int length = command->length;
 207         bool wait = command->wait;
 208         unsigned int registerIndex = command->registerIndex;
 209
 210         /* special case for hid_descr_cmd */
 211         if (command == &hid_descr_cmd) {
 212                 cmd->c.reg = ihid->wHIDDescRegister;
 213         } else {
 214                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 215                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 216         }
 217
 218         if (length > 2) {
 219                 cmd->c.opcode = command->opcode;
 220                 cmd->c.reportTypeID = reportID | reportType << 4;
 221         }
 222
 223         memcpy(cmd->data + length, args, args_len);
 224         length += args_len;
 225
 226         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 227
 228         msg[0].addr = client->addr;
 229         msg[0].flags = client->flags & I2C_M_TEN;
 230         msg[0].len = length;
 231         msg[0].buf = cmd->data;
 232         if (data_len > 0) {
 233                 msg[1].addr = client->addr;
 234                 msg[1].flags = client->flags & I2C_M_TEN;
 235                 msg[1].flags |= I2C_M_RD;
 236                 msg[1].len = data_len;
 237                 msg[1].buf = buf_recv;
 238                 msg_num = 2;
 239                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 240         }
 241
 242         if (wait)
 243                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 244
 245         ret = i2c_transfer(client->adapter, msg, msg_num);
 246
 247         if (data_len > 0)
 248                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 249
 250         if (ret != msg_num)
 251                 return ret < 0 ? ret : -EIO;
 252
 253         ret = 0;
 254
 255         if (wait) {
 256                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 257                 if (!wait_event_timeout(ihid->wait,
 258                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 259                                 msecs_to_jiffies(5000)))
 260                         ret = -ENODATA;
 261                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 262         }
 263
 264         return ret;
 265 }
 266
 267 static int i2c_hid_command(struct i2c_client *client,
 268                 const struct i2c_hid_cmd *command,
 269                 unsigned char *buf_recv, int data_len)
 270 {
 271         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 272                                 buf_recv, data_len);
 273 }
 274
 275 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 276                 u8 reportID, unsigned char *buf_recv, int data_len)
 277 {
 278         struct i2c_hid *ihid = i2c_get_clientdata(client);
 279         u8 args[3];
 280         int ret;
 281         int args_len = 0;
 282         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 283
 284         i2c_hid_dbg(ihid, "%s\n", __func__);
 285
 286         if (reportID >= 0x0F) {
 287                 args[args_len++] = reportID;
 288                 reportID = 0x0F;
 289         }
 290
 291         args[args_len++] = readRegister & 0xFF;
 292         args[args_len++] = readRegister >> 8;
 293
 294         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 295                 reportType, args, args_len, buf_recv, data_len);
 296         if (ret) {
 297                 dev_err(&client->dev,
 298                         "failed to retrieve report from device.\n");
 299                 return ret;
 300         }
 301
 302         return 0;
 303 }
 304
 305 /**
 306  * i2c_hid_set_or_send_report: forward an incoming report to the device
 307  * @client: the i2c_client of the device
 308  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 309  * @reportID: the report ID
 310  * @buf: the actual data to transfer, without the report ID
 311  * @len: size of buf
 312  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 313  */
 314 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 315                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 316 {
 317         struct i2c_hid *ihid = i2c_get_clientdata(client);
 318         u8 *args = ihid->argsbuf;
 319         const struct i2c_hid_cmd *hidcmd;
 320         int ret;
 321         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 322         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 323         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 324         u16 size;
 325         int args_len;
 326         int index = 0;
 327
 328         i2c_hid_dbg(ihid, "%s\n", __func__);
 329
 330         if (data_len > ihid->bufsize)
 331                 return -EINVAL;
 332
 333         size =          2                       /* size */ +
 334                         (reportID ? 1 : 0)      /* reportID */ +
 335                         data_len                /* buf */;
 336         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 337                         2                       /* dataRegister */ +
 338                         size                    /* args */;
 339
 340         if (!use_data && maxOutputLength == 0)
 341                 return -ENOSYS;
 342
 343         if (reportID >= 0x0F) {
 344                 args[index++] = reportID;
 345                 reportID = 0x0F;
 346         }
 347
 348         /*
 349          * use the data register for feature reports or if the device does not
 350          * support the output register
 351          */
 352         if (use_data) {
 353                 args[index++] = dataRegister & 0xFF;
 354                 args[index++] = dataRegister >> 8;
 355                 hidcmd = &hid_set_report_cmd;
 356         } else {
 357                 args[index++] = outputRegister & 0xFF;
 358                 args[index++] = outputRegister >> 8;
 359                 hidcmd = &hid_no_cmd;
 360         }
 361
 362         args[index++] = size & 0xFF;
 363         args[index++] = size >> 8;
 364
 365         if (reportID)
 366                 args[index++] = reportID;
 367
 368         memcpy(&args[index], buf, data_len);
 369
 370         ret = __i2c_hid_command(client, hidcmd, reportID,
 371                 reportType, args, args_len, NULL, 0);
 372         if (ret) {
 373                 dev_err(&client->dev, "failed to set a report to device.\n");
 374                 return ret;
 375         }
 376
 377         return data_len;
 378 }
 379
 380 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 381 {
 382         struct i2c_hid *ihid = i2c_get_clientdata(client);
 383         int ret;
 384
 385         i2c_hid_dbg(ihid, "%s\n", __func__);
 386
 387         /*
 388          * Some devices require to send a command to wakeup before power on.
 389          * The call will get a return value (EREMOTEIO) but device will be
 390          * triggered and activated. After that, it goes like a normal device.
 391          */
 392         if (power_state == I2C_HID_PWR_ON &&
 393             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 394                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
 395
 396                 /* Device was already activated */
 397                 if (!ret)
 398                         goto set_pwr_exit;
 399         }
 400
 401         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 402                 0, NULL, 0, NULL, 0);
 403
 404         if (ret)
 405                 dev_err(&client->dev, "failed to change power setting.\n");
 406
 407 set_pwr_exit:
 408         return ret;
 409 }
 410
 411 static int i2c_hid_hwreset(struct i2c_client *client)
 412 {
 413         struct i2c_hid *ihid = i2c_get_clientdata(client);
 414         int ret;
 415
 416         i2c_hid_dbg(ihid, "%s\n", __func__);
 417
 418         /*
 419          * This prevents sending feature reports while the device is
 420          * being reset. Otherwise we may lose the reset complete
 421          * interrupt.
 422          */
 423         mutex_lock(&ihid->reset_lock);
 424
 425         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 426         if (ret)
 427                 goto out_unlock;
 428
 429         /*
 430          * The HID over I2C specification states that if a DEVICE needs time
 431          * after the PWR_ON request, it should utilise CLOCK stretching.
 432          * However, it has been observered that the Windows driver provides a
 433          * 1ms sleep between the PWR_ON and RESET requests and that some devices
 434          * rely on this.
 435          */
 436         usleep_range(1000, 5000);
 437
 438         i2c_hid_dbg(ihid, "resetting...\n");
 439
 440         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 441         if (ret) {
 442                 dev_err(&client->dev, "failed to reset device.\n");
 443                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 444         }
 445
 446 out_unlock:
 447         mutex_unlock(&ihid->reset_lock);
 448         return ret;
 449 }
 450
 451 static void i2c_hid_get_input(struct i2c_hid *ihid)
 452 {
 453         int ret, ret_size;
 454         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 455
 456         if (size > ihid->bufsize)
 457                 size = ihid->bufsize;
 458
 459         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 460         if (ret != size) {
 461                 if (ret < 0)
 462                         return;
 463
 464                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 465                         __func__, ret, size);
 466                 return;
 467         }
 468
 469         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 470
 471         if (!ret_size) {
 472                 /* host or device initiated RESET completed */
 473                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 474                         wake_up(&ihid->wait);
 475                 return;
 476         }
 477
 478         if (ret_size > size) {
 479                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 480                         __func__, size, ret_size);
 481                 return;
 482         }
 483
 484         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 485
 486         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 487                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 488                                 ret_size - 2, 1);
 489
 490         return;
 491 }
 492
 493 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 494 {
 495         struct i2c_hid *ihid = dev_id;
 496
 497         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 498                 return IRQ_HANDLED;
 499
 500         i2c_hid_get_input(ihid);
 501
 502         return IRQ_HANDLED;
 503 }
 504
 505 static int i2c_hid_get_report_length(struct hid_report *report)
 506 {
 507         return ((report->size - 1) >> 3) + 1 +
 508                 report->device->report_enum[report->type].numbered + 2;
 509 }
 510
 511 /*
 512  * Traverse the supplied list of reports and find the longest
 513  */
 514 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 515                 unsigned int *max)
 516 {
 517         struct hid_report *report;
 518         unsigned int size;
 519
 520         /* We should not rely on wMaxInputLength, as some devices may set it to
 521          * a wrong length. */
 522         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 523                 size = i2c_hid_get_report_length(report);
 524                 if (*max < size)
 525                         *max = size;
 526         }
 527 }
 528
 529 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 530 {
 531         kfree(ihid->inbuf);
 532         kfree(ihid->rawbuf);
 533         kfree(ihid->argsbuf);
 534         kfree(ihid->cmdbuf);
 535         ihid->inbuf = NULL;
 536         ihid->rawbuf = NULL;
 537         ihid->cmdbuf = NULL;
 538         ihid->argsbuf = NULL;
 539         ihid->bufsize = 0;
 540 }
 541
 542 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 543 {
 544         /* the worst case is computed from the set_report command with a
 545          * reportID > 15 and the maximum report length */
 546         int args_len = sizeof(__u8) + /* optional ReportID byte */
 547                        sizeof(__u16) + /* data register */
 548                        sizeof(__u16) + /* size of the report */
 549                        report_size; /* report */
 550
 551         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 552         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 553         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 554         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 555
 556         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 557                 i2c_hid_free_buffers(ihid);
 558                 return -ENOMEM;
 559         }
 560
 561         ihid->bufsize = report_size;
 562
 563         return 0;
 564 }
 565
 566 static int i2c_hid_get_raw_report(struct hid_device *hid,
 567                 unsigned char report_number, __u8 *buf, size_t count,
 568                 unsigned char report_type)
 569 {
 570         struct i2c_client *client = hid->driver_data;
 571         struct i2c_hid *ihid = i2c_get_clientdata(client);
 572         size_t ret_count, ask_count;
 573         int ret;
 574
 575         if (report_type == HID_OUTPUT_REPORT)
 576                 return -EINVAL;
 577
 578         /* +2 bytes to include the size of the reply in the query buffer */
 579         ask_count = min(count + 2, (size_t)ihid->bufsize);
 580
 581         ret = i2c_hid_get_report(client,
 582                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 583                         report_number, ihid->rawbuf, ask_count);
 584
 585         if (ret < 0)
 586                 return ret;
 587
 588         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 589
 590         if (ret_count <= 2)
 591                 return 0;
 592
 593         ret_count = min(ret_count, ask_count);
 594
 595         /* The query buffer contains the size, dropping it in the reply */
 596         count = min(count, ret_count - 2);
 597         memcpy(buf, ihid->rawbuf + 2, count);
 598
 599         return count;
 600 }
 601
 602 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 603                 size_t count, unsigned char report_type, bool use_data)
 604 {
 605         struct i2c_client *client = hid->driver_data;
 606         struct i2c_hid *ihid = i2c_get_clientdata(client);
 607         int report_id = buf[0];
 608         int ret;
 609
 610         if (report_type == HID_INPUT_REPORT)
 611                 return -EINVAL;
 612
 613         mutex_lock(&ihid->reset_lock);
 614
 615         if (report_id) {
 616                 buf++;
 617                 count--;
 618         }
 619
 620         ret = i2c_hid_set_or_send_report(client,
 621                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 622                                 report_id, buf, count, use_data);
 623
 624         if (report_id && ret >= 0)
 625                 ret++; /* add report_id to the number of transfered bytes */
 626
 627         mutex_unlock(&ihid->reset_lock);
 628
 629         return ret;
 630 }
 631
 632 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 633                 size_t count)
 634 {
 635         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 636                         false);
 637 }
 638
 639 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 640                                __u8 *buf, size_t len, unsigned char rtype,
 641                                int reqtype)
 642 {
 643         switch (reqtype) {
 644         case HID_REQ_GET_REPORT:
 645                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 646         case HID_REQ_SET_REPORT:
 647                 if (buf[0] != reportnum)
 648                         return -EINVAL;
 649                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 650         default:
 651                 return -EIO;
 652         }
 653 }
 654
 655 static int i2c_hid_parse(struct hid_device *hid)
 656 {
 657         struct i2c_client *client = hid->driver_data;
 658         struct i2c_hid *ihid = i2c_get_clientdata(client);
 659         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 660         unsigned int rsize;
 661         char *rdesc;
 662         int ret;
 663         int tries = 3;
 664
 665         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 666
 667         rsize = le16_to_cpu(hdesc->wReportDescLength);
 668         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 669                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 670                 return -EINVAL;
 671         }
 672
 673         do {
 674                 ret = i2c_hid_hwreset(client);
 675                 if (ret)
 676                         msleep(1000);
 677         } while (tries-- > 0 && ret);
 678
 679         if (ret)
 680                 return ret;
 681
 682         rdesc = kzalloc(rsize, GFP_KERNEL);
 683
 684         if (!rdesc) {
 685                 dbg_hid("couldn't allocate rdesc memory\n");
 686                 return -ENOMEM;
 687         }
 688
 689         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 690
 691         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 692         if (ret) {
 693                 hid_err(hid, "reading report descriptor failed\n");
 694                 kfree(rdesc);
 695                 return -EIO;
 696         }
 697
 698         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 699
 700         ret = hid_parse_report(hid, rdesc, rsize);
 701         kfree(rdesc);
 702         if (ret) {
 703                 dbg_hid("parsing report descriptor failed\n");
 704                 return ret;
 705         }
 706
 707         return 0;
 708 }
 709
 710 static int i2c_hid_start(struct hid_device *hid)
 711 {
 712         struct i2c_client *client = hid->driver_data;
 713         struct i2c_hid *ihid = i2c_get_clientdata(client);
 714         int ret;
 715         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 716
 717         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 718         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 719         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 720
 721         if (bufsize > ihid->bufsize) {
 722                 disable_irq(client->irq);
 723                 i2c_hid_free_buffers(ihid);
 724
 725                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 726                 enable_irq(client->irq);
 727
 728                 if (ret)
 729                         return ret;
 730         }
 731
 732         return 0;
 733 }
 734
 735 static void i2c_hid_stop(struct hid_device *hid)
 736 {
 737         hid->claimed = 0;
 738 }
 739
 740 static int i2c_hid_open(struct hid_device *hid)
 741 {
 742         struct i2c_client *client = hid->driver_data;
 743         struct i2c_hid *ihid = i2c_get_clientdata(client);
 744         int ret = 0;
 745
 746         mutex_lock(&i2c_hid_open_mut);
 747         if (!hid->open++) {
 748                 ret = pm_runtime_get_sync(&client->dev);
 749                 if (ret < 0) {
 750                         hid->open--;
 751                         goto done;
 752                 }
 753                 set_bit(I2C_HID_STARTED, &ihid->flags);
 754         }
 755 done:
 756         mutex_unlock(&i2c_hid_open_mut);
 757         return ret < 0 ? ret : 0;
 758 }
 759
 760 static void i2c_hid_close(struct hid_device *hid)
 761 {
 762         struct i2c_client *client = hid->driver_data;
 763         struct i2c_hid *ihid = i2c_get_clientdata(client);
 764
 765         /* protecting hid->open to make sure we don't restart
 766          * data acquistion due to a resumption we no longer
 767          * care about
 768          */
 769         mutex_lock(&i2c_hid_open_mut);
 770         if (!--hid->open) {
 771                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 772
 773                 /* Save some power */
 774                 pm_runtime_put(&client->dev);
 775         }
 776         mutex_unlock(&i2c_hid_open_mut);
 777 }
 778
 779 static int i2c_hid_power(struct hid_device *hid, int lvl)
 780 {
 781         struct i2c_client *client = hid->driver_data;
 782         struct i2c_hid *ihid = i2c_get_clientdata(client);
 783
 784         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 785
 786         switch (lvl) {
 787         case PM_HINT_FULLON:
 788                 pm_runtime_get_sync(&client->dev);
 789                 break;
 790         case PM_HINT_NORMAL:
 791                 pm_runtime_put(&client->dev);
 792                 break;
 793         }
 794         return 0;
 795 }
 796
 797 static struct hid_ll_driver i2c_hid_ll_driver = {
 798         .parse = i2c_hid_parse,
 799         .start = i2c_hid_start,
 800         .stop = i2c_hid_stop,
 801         .open = i2c_hid_open,
 802         .close = i2c_hid_close,
 803         .power = i2c_hid_power,
 804         .output_report = i2c_hid_output_report,
 805         .raw_request = i2c_hid_raw_request,
 806 };
 807
 808 static int i2c_hid_init_irq(struct i2c_client *client)
 809 {
 810         struct i2c_hid *ihid = i2c_get_clientdata(client);
 811         unsigned long irqflags = 0;
 812         int ret;
 813
 814         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 815
 816         if (!irq_get_trigger_type(client->irq))
 817                 irqflags = IRQF_TRIGGER_LOW;
 818
 819         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 820                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 821         if (ret < 0) {
 822                 dev_warn(&client->dev,
 823                         "Could not register for %s interrupt, irq = %d,"
 824                         " ret = %d\n",
 825                         client->name, client->irq, ret);
 826
 827                 return ret;
 828         }
 829
 830         return 0;
 831 }
 832
 833 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 834 {
 835         struct i2c_client *client = ihid->client;
 836         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 837         unsigned int dsize;
 838         int ret;
 839
 840         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 841         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 842         ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
 843                                 sizeof(struct i2c_hid_desc));
 844         if (ret) {
 845                 dev_err(&client->dev, "hid_descr_cmd failed\n");
 846                 return -ENODEV;
 847         }
 848
 849         /* Validate the length of HID descriptor, the 4 first bytes:
 850          * bytes 0-1 -> length
 851          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 852         /* check bcdVersion == 1.0 */
 853         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 854                 dev_err(&client->dev,
 855                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 856                         le16_to_cpu(hdesc->bcdVersion));
 857                 return -ENODEV;
 858         }
 859
 860         /* Descriptor length should be 30 bytes as per the specification */
 861         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 862         if (dsize != sizeof(struct i2c_hid_desc)) {
 863                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 864                         dsize);
 865                 return -ENODEV;
 866         }
 867         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 868         return 0;
 869 }
 870
 871 #ifdef CONFIG_ACPI
 872 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 873                 struct i2c_hid_platform_data *pdata)
 874 {
 875         static u8 i2c_hid_guid[] = {
 876                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 877                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 878         };
 879         union acpi_object *obj;
 880         struct acpi_device *adev;
 881         acpi_handle handle;
 882
 883         handle = ACPI_HANDLE(&client->dev);
 884         if (!handle || acpi_bus_get_device(handle, &adev))
 885                 return -ENODEV;
 886
 887         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 888                                       ACPI_TYPE_INTEGER);
 889         if (!obj) {
 890                 dev_err(&client->dev, "device _DSM execution failed\n");
 891                 return -ENODEV;
 892         }
 893
 894         pdata->hid_descriptor_address = obj->integer.value;
 895         ACPI_FREE(obj);
 896
 897         return 0;
 898 }
 899
 900 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 901         {"ACPI0C50", 0 },
 902         {"PNP0C50", 0 },
 903         { },
 904 };
 905 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 906 #else
 907 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 908                 struct i2c_hid_platform_data *pdata)
 909 {
 910         return -ENODEV;
 911 }
 912 #endif
 913
 914 #ifdef CONFIG_OF
 915 static int i2c_hid_of_probe(struct i2c_client *client,
 916                 struct i2c_hid_platform_data *pdata)
 917 {
 918         struct device *dev = &client->dev;
 919         u32 val;
 920         int ret;
 921
 922         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 923         if (ret) {
 924                 dev_err(&client->dev, "HID register address not provided\n");
 925                 return -ENODEV;
 926         }
 927         if (val >> 16) {
 928                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 929                         val);
 930                 return -EINVAL;
 931         }
 932         pdata->hid_descriptor_address = val;
 933
 934         ret = of_property_read_u32(dev->of_node, "post-power-on-delay-ms",
 935                                    &val);
 936         if (!ret)
 937                 pdata->post_power_delay_ms = val;
 938
 939         return 0;
 940 }
 941
 942 static const struct of_device_id i2c_hid_of_match[] = {
 943         { .compatible = "hid-over-i2c" },
 944         {},
 945 };
 946 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 947 #else
 948 static inline int i2c_hid_of_probe(struct i2c_client *client,
 949                 struct i2c_hid_platform_data *pdata)
 950 {
 951         return -ENODEV;
 952 }
 953 #endif
 954
 955 static int i2c_hid_probe(struct i2c_client *client,
 956                          const struct i2c_device_id *dev_id)
 957 {
 958         int ret;
 959         struct i2c_hid *ihid;
 960         struct hid_device *hid;
 961         __u16 hidRegister;
 962         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 963
 964         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 965
 966         if (!client->irq) {
 967                 dev_err(&client->dev,
 968                         "HID over i2c has not been provided an Int IRQ\n");
 969                 return -EINVAL;
 970         }
 971
 972         if (client->irq < 0) {
 973                 if (client->irq != -EPROBE_DEFER)
 974                         dev_err(&client->dev,
 975                                 "HID over i2c doesn't have a valid IRQ\n");
 976                 return client->irq;
 977         }
 978
 979         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 980         if (!ihid)
 981                 return -ENOMEM;
 982
 983         if (client->dev.of_node) {
 984                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 985                 if (ret)
 986                         goto err;
 987         } else if (!platform_data) {
 988                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
 989                 if (ret) {
 990                         dev_err(&client->dev,
 991                                 "HID register address not provided\n");
 992                         goto err;
 993                 }
 994         } else {
 995                 ihid->pdata = *platform_data;
 996         }
 997
 998         ihid->pdata.supply = devm_regulator_get(&client->dev, "vdd");
 999         if (IS_ERR(ihid->pdata.supply)) {
1000                 ret = PTR_ERR(ihid->pdata.supply);
1001                 if (ret != -EPROBE_DEFER)
1002                         dev_err(&client->dev, "Failed to get regulator: %d\n",
1003                                 ret);
1004                 goto err;
1005         }
1006
1007         ret = regulator_enable(ihid->pdata.supply);
1008         if (ret < 0) {
1009                 dev_err(&client->dev, "Failed to enable regulator: %d\n",
1010                         ret);
1011                 goto err;
1012         }
1013         if (ihid->pdata.post_power_delay_ms)
1014                 msleep(ihid->pdata.post_power_delay_ms);
1015
1016         i2c_set_clientdata(client, ihid);
1017
1018         ihid->client = client;
1019
1020         hidRegister = ihid->pdata.hid_descriptor_address;
1021         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1022
1023         init_waitqueue_head(&ihid->wait);
1024         mutex_init(&ihid->reset_lock);
1025
1026         /* we need to allocate the command buffer without knowing the maximum
1027          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1028          * real computation later. */
1029         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1030         if (ret < 0)
1031                 goto err_regulator;
1032
1033         pm_runtime_get_noresume(&client->dev);
1034         pm_runtime_set_active(&client->dev);
1035         pm_runtime_enable(&client->dev);
1036         device_enable_async_suspend(&client->dev);
1037
1038         ret = i2c_hid_fetch_hid_descriptor(ihid);
1039         if (ret < 0)
1040                 goto err_pm;
1041
1042         ret = i2c_hid_init_irq(client);
1043         if (ret < 0)
1044                 goto err_pm;
1045
1046         hid = hid_allocate_device();
1047         if (IS_ERR(hid)) {
1048                 ret = PTR_ERR(hid);
1049                 goto err_irq;
1050         }
1051
1052         ihid->hid = hid;
1053
1054         hid->driver_data = client;
1055         hid->ll_driver = &i2c_hid_ll_driver;
1056         hid->dev.parent = &client->dev;
1057         hid->bus = BUS_I2C;
1058         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1059         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1060         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1061
1062         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1063                  client->name, hid->vendor, hid->product);
1064         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1065
1066         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1067
1068         ret = hid_add_device(hid);
1069         if (ret) {
1070                 if (ret != -ENODEV)
1071                         hid_err(client, "can't add hid device: %d\n", ret);
1072                 goto err_mem_free;
1073         }
1074
1075         pm_runtime_put(&client->dev);
1076         return 0;
1077
1078 err_mem_free:
1079         hid_destroy_device(hid);
1080
1081 err_irq:
1082         free_irq(client->irq, ihid);
1083
1084 err_pm:
1085         pm_runtime_put_noidle(&client->dev);
1086         pm_runtime_disable(&client->dev);
1087
1088 err_regulator:
1089         regulator_disable(ihid->pdata.supply);
1090
1091 err:
1092         i2c_hid_free_buffers(ihid);
1093         kfree(ihid);
1094         return ret;
1095 }
1096
1097 static int i2c_hid_remove(struct i2c_client *client)
1098 {
1099         struct i2c_hid *ihid = i2c_get_clientdata(client);
1100         struct hid_device *hid;
1101
1102         pm_runtime_get_sync(&client->dev);
1103         pm_runtime_disable(&client->dev);
1104         pm_runtime_set_suspended(&client->dev);
1105         pm_runtime_put_noidle(&client->dev);
1106
1107         hid = ihid->hid;
1108         hid_destroy_device(hid);
1109
1110         free_irq(client->irq, ihid);
1111
1112         if (ihid->bufsize)
1113                 i2c_hid_free_buffers(ihid);
1114
1115         regulator_disable(ihid->pdata.supply);
1116
1117         kfree(ihid);
1118
1119         return 0;
1120 }
1121
1122 static void i2c_hid_shutdown(struct i2c_client *client)
1123 {
1124         struct i2c_hid *ihid = i2c_get_clientdata(client);
1125
1126         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1127         free_irq(client->irq, ihid);
1128 }
1129
1130 #ifdef CONFIG_PM_SLEEP
1131 static int i2c_hid_suspend(struct device *dev)
1132 {
1133         struct i2c_client *client = to_i2c_client(dev);
1134         struct i2c_hid *ihid = i2c_get_clientdata(client);
1135         struct hid_device *hid = ihid->hid;
1136         int ret;
1137         int wake_status;
1138
1139         if (hid->driver && hid->driver->suspend) {
1140                 /*
1141                  * Wake up the device so that IO issues in
1142                  * HID driver's suspend code can succeed.
1143                  */
1144                 ret = pm_runtime_resume(dev);
1145                 if (ret < 0)
1146                         return ret;
1147
1148                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1149                 if (ret < 0)
1150                         return ret;
1151         }
1152
1153         if (!pm_runtime_suspended(dev)) {
1154                 /* Save some power */
1155                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1156
1157                 disable_irq(client->irq);
1158         }
1159
1160         if (device_may_wakeup(&client->dev)) {
1161                 wake_status = enable_irq_wake(client->irq);
1162                 if (!wake_status)
1163                         ihid->irq_wake_enabled = true;
1164                 else
1165                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1166                                 wake_status);
1167         } else {
1168                 ret = regulator_disable(ihid->pdata.supply);
1169                 if (ret < 0)
1170                         hid_warn(hid, "Failed to disable supply: %d\n", ret);
1171         }
1172
1173         return 0;
1174 }
1175
1176 static int i2c_hid_resume(struct device *dev)
1177 {
1178         int ret;
1179         struct i2c_client *client = to_i2c_client(dev);
1180         struct i2c_hid *ihid = i2c_get_clientdata(client);
1181         struct hid_device *hid = ihid->hid;
1182         int wake_status;
1183
1184         if (!device_may_wakeup(&client->dev)) {
1185                 ret = regulator_enable(ihid->pdata.supply);
1186                 if (ret < 0)
1187                         hid_warn(hid, "Failed to enable supply: %d\n", ret);
1188                 if (ihid->pdata.post_power_delay_ms)
1189                         msleep(ihid->pdata.post_power_delay_ms);
1190         } else if (ihid->irq_wake_enabled) {
1191                 wake_status = disable_irq_wake(client->irq);
1192                 if (!wake_status)
1193                         ihid->irq_wake_enabled = false;
1194                 else
1195                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1196                                 wake_status);
1197         }
1198
1199         /* We'll resume to full power */
1200         pm_runtime_disable(dev);
1201         pm_runtime_set_active(dev);
1202         pm_runtime_enable(dev);
1203
1204         enable_irq(client->irq);
1205         ret = i2c_hid_hwreset(client);
1206         if (ret)
1207                 return ret;
1208
1209         if (hid->driver && hid->driver->reset_resume) {
1210                 ret = hid->driver->reset_resume(hid);
1211                 return ret;
1212         }
1213
1214         return 0;
1215 }
1216 #endif
1217
1218 #ifdef CONFIG_PM
1219 static int i2c_hid_runtime_suspend(struct device *dev)
1220 {
1221         struct i2c_client *client = to_i2c_client(dev);
1222
1223         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1224         disable_irq(client->irq);
1225         return 0;
1226 }
1227
1228 static int i2c_hid_runtime_resume(struct device *dev)
1229 {
1230         struct i2c_client *client = to_i2c_client(dev);
1231
1232         enable_irq(client->irq);
1233         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1234         return 0;
1235 }
1236 #endif
1237
1238 static const struct dev_pm_ops i2c_hid_pm = {
1239         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1240         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1241                            NULL)
1242 };
1243
1244 static const struct i2c_device_id i2c_hid_id_table[] = {
1245         { "hid", 0 },
1246         { "hid-over-i2c", 0 },
1247         { },
1248 };
1249 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1250
1251
1252 static struct i2c_driver i2c_hid_driver = {
1253         .driver = {
1254                 .name   = "i2c_hid",
1255                 .pm     = &i2c_hid_pm,
1256                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1257                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1258         },
1259
1260         .probe          = i2c_hid_probe,
1261         .remove         = i2c_hid_remove,
1262         .shutdown       = i2c_hid_shutdown,
1263         .id_table       = i2c_hid_id_table,
1264 };
1265
1266 module_i2c_driver(i2c_hid_driver);
1267
1268 MODULE_DESCRIPTION("HID over I2C core driver");
1269 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1270 MODULE_LICENSE("GPL");