drivers/hid/i2c-hid/i2c-hid-core.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/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
  39 #include "../hid-ids.h"
  40 #include "i2c-hid.h"
  41
  42 /* quirks to control the device */
  43 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV        BIT(0)
  44 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET        BIT(1)
  45 #define I2C_HID_QUIRK_BOGUS_IRQ                 BIT(4)
  46 #define I2C_HID_QUIRK_RESET_ON_RESUME           BIT(5)
  47 #define I2C_HID_QUIRK_BAD_INPUT_SIZE            BIT(6)
  48 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET     BIT(7)
  49
  50
  51 /* flags */
  52 #define I2C_HID_STARTED         0
  53 #define I2C_HID_RESET_PENDING   1
  54 #define I2C_HID_READ_PENDING    2
  55
  56 #define I2C_HID_PWR_ON          0x00
  57 #define I2C_HID_PWR_SLEEP       0x01
  58
  59 /* debug option */
  60 static bool debug;
  61 module_param(debug, bool, 0444);
  62 MODULE_PARM_DESC(debug, "print a lot of debug information");
  63
  64 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  65 do {                                                                      \
  66         if (debug)                                                        \
  67                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  68 } while (0)
  69
  70 struct i2c_hid_desc {
  71         __le16 wHIDDescLength;
  72         __le16 bcdVersion;
  73         __le16 wReportDescLength;
  74         __le16 wReportDescRegister;
  75         __le16 wInputRegister;
  76         __le16 wMaxInputLength;
  77         __le16 wOutputRegister;
  78         __le16 wMaxOutputLength;
  79         __le16 wCommandRegister;
  80         __le16 wDataRegister;
  81         __le16 wVendorID;
  82         __le16 wProductID;
  83         __le16 wVersionID;
  84         __le32 reserved;
  85 } __packed;
  86
  87 struct i2c_hid_cmd {
  88         unsigned int registerIndex;
  89         __u8 opcode;
  90         unsigned int length;
  91 };
  92
  93 union command {
  94         u8 data[0];
  95         struct cmd {
  96                 __le16 reg;
  97                 __u8 reportTypeID;
  98                 __u8 opcode;
  99                 __u8 reportID;
 100         } __packed c;
 101 };
 102
 103 #define I2C_HID_CMD(opcode_) \
 104         .opcode = opcode_, .length = 4, \
 105         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 106
 107 /* fetch HID descriptor */
 108 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 109 /* fetch report descriptors */
 110 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 111                 .registerIndex = offsetof(struct i2c_hid_desc,
 112                         wReportDescRegister),
 113                 .opcode = 0x00,
 114                 .length = 2 };
 115 /* commands */
 116 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01) };
 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 /* The main device structure */
 133 struct i2c_hid {
 134         struct i2c_client       *client;        /* i2c client */
 135         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 136         union {
 137                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 138                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 139         };
 140         __le16                  wHIDDescRegister; /* location of the i2c
 141                                                    * register of the HID
 142                                                    * descriptor. */
 143         unsigned int            bufsize;        /* i2c buffer size */
 144         u8                      *inbuf;         /* Input buffer */
 145         u8                      *rawbuf;        /* Raw Input buffer */
 146         u8                      *cmdbuf;        /* Command buffer */
 147         u8                      *argsbuf;       /* Command arguments buffer */
 148
 149         unsigned long           flags;          /* device flags */
 150         unsigned long           quirks;         /* Various quirks */
 151
 152         wait_queue_head_t       wait;           /* For waiting the interrupt */
 153
 154         bool                    irq_wake_enabled;
 155         struct mutex            reset_lock;
 156
 157         struct i2chid_ops       *ops;
 158 };
 159
 160 static const struct i2c_hid_quirks {
 161         __u16 idVendor;
 162         __u16 idProduct;
 163         __u32 quirks;
 164 } i2c_hid_quirks[] = {
 165         { USB_VENDOR_ID_WEIDA, HID_ANY_ID,
 166                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 167         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 168                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 169         { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
 170                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 171         { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
 172                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 173         { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
 174                  I2C_HID_QUIRK_RESET_ON_RESUME },
 175         { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
 176                  I2C_HID_QUIRK_RESET_ON_RESUME },
 177         { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 178                 I2C_HID_QUIRK_BAD_INPUT_SIZE },
 179         /*
 180          * Sending the wakeup after reset actually break ELAN touchscreen controller
 181          */
 182         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 183                  I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 184                  I2C_HID_QUIRK_BOGUS_IRQ },
 185         { 0, 0 }
 186 };
 187
 188 /*
 189  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 190  * @idVendor: the 16-bit vendor ID
 191  * @idProduct: the 16-bit product ID
 192  *
 193  * Returns: a u32 quirks value.
 194  */
 195 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 196 {
 197         u32 quirks = 0;
 198         int n;
 199
 200         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 201                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 202                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 203                      i2c_hid_quirks[n].idProduct == idProduct))
 204                         quirks = i2c_hid_quirks[n].quirks;
 205
 206         return quirks;
 207 }
 208
 209 static int __i2c_hid_command(struct i2c_hid *ihid,
 210                 const struct i2c_hid_cmd *command, u8 reportID,
 211                 u8 reportType, u8 *args, int args_len,
 212                 unsigned char *buf_recv, int data_len)
 213 {
 214         struct i2c_client *client = ihid->client;
 215         union command *cmd = (union command *)ihid->cmdbuf;
 216         int ret;
 217         struct i2c_msg msg[2];
 218         int msg_num = 1;
 219
 220         int length = command->length;
 221         unsigned int registerIndex = command->registerIndex;
 222
 223         /* special case for hid_descr_cmd */
 224         if (command == &hid_descr_cmd) {
 225                 cmd->c.reg = ihid->wHIDDescRegister;
 226         } else {
 227                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 228                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 229         }
 230
 231         if (length > 2) {
 232                 cmd->c.opcode = command->opcode;
 233                 if (reportID < 0x0F) {
 234                         cmd->c.reportTypeID = reportType << 4 | reportID;
 235                 } else {
 236                         cmd->c.reportTypeID = reportType << 4 | 0x0F;
 237                         cmd->c.reportID = reportID;
 238                         length++;
 239                 }
 240         }
 241
 242         memcpy(cmd->data + length, args, args_len);
 243         length += args_len;
 244
 245         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 246
 247         msg[0].addr = client->addr;
 248         msg[0].flags = client->flags & I2C_M_TEN;
 249         msg[0].len = length;
 250         msg[0].buf = cmd->data;
 251         if (data_len > 0) {
 252                 msg[1].addr = client->addr;
 253                 msg[1].flags = client->flags & I2C_M_TEN;
 254                 msg[1].flags |= I2C_M_RD;
 255                 msg[1].len = data_len;
 256                 msg[1].buf = buf_recv;
 257                 msg_num = 2;
 258                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 259         }
 260
 261         ret = i2c_transfer(client->adapter, msg, msg_num);
 262
 263         if (data_len > 0)
 264                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 265
 266         if (ret != msg_num)
 267                 return ret < 0 ? ret : -EIO;
 268
 269         return 0;
 270 }
 271
 272 static int i2c_hid_command(struct i2c_hid *ihid,
 273                 const struct i2c_hid_cmd *command,
 274                 unsigned char *buf_recv, int data_len)
 275 {
 276         return __i2c_hid_command(ihid, command, 0, 0, NULL, 0,
 277                                 buf_recv, data_len);
 278 }
 279
 280 static int i2c_hid_get_report(struct i2c_hid *ihid, u8 reportType,
 281                 u8 reportID, unsigned char *buf_recv, int data_len)
 282 {
 283         u8 args[2];
 284         int ret;
 285         int args_len = 0;
 286         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 287
 288         i2c_hid_dbg(ihid, "%s\n", __func__);
 289
 290         args[args_len++] = readRegister & 0xFF;
 291         args[args_len++] = readRegister >> 8;
 292
 293         ret = __i2c_hid_command(ihid, &hid_get_report_cmd, reportID,
 294                 reportType, args, args_len, buf_recv, data_len);
 295         if (ret) {
 296                 dev_err(&ihid->client->dev,
 297                         "failed to retrieve report from device.\n");
 298                 return ret;
 299         }
 300
 301         return 0;
 302 }
 303
 304 /**
 305  * i2c_hid_set_or_send_report: forward an incoming report to the device
 306  * @ihid: the i2c hid device
 307  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 308  * @reportID: the report ID
 309  * @buf: the actual data to transfer, without the report ID
 310  * @data_len: size of buf
 311  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 312  */
 313 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid, u8 reportType,
 314                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 315 {
 316         u8 *args = ihid->argsbuf;
 317         const struct i2c_hid_cmd *hidcmd;
 318         int ret;
 319         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 320         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 321         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 322         u16 size;
 323         int args_len;
 324         int index = 0;
 325
 326         i2c_hid_dbg(ihid, "%s\n", __func__);
 327
 328         if (data_len > ihid->bufsize)
 329                 return -EINVAL;
 330
 331         size =          2                       /* size */ +
 332                         (reportID ? 1 : 0)      /* reportID */ +
 333                         data_len                /* buf */;
 334         args_len =      2                       /* dataRegister */ +
 335                         size                    /* args */;
 336
 337         if (!use_data && maxOutputLength == 0)
 338                 return -ENOSYS;
 339
 340         /*
 341          * use the data register for feature reports or if the device does not
 342          * support the output register
 343          */
 344         if (use_data) {
 345                 args[index++] = dataRegister & 0xFF;
 346                 args[index++] = dataRegister >> 8;
 347                 hidcmd = &hid_set_report_cmd;
 348         } else {
 349                 args[index++] = outputRegister & 0xFF;
 350                 args[index++] = outputRegister >> 8;
 351                 hidcmd = &hid_no_cmd;
 352         }
 353
 354         args[index++] = size & 0xFF;
 355         args[index++] = size >> 8;
 356
 357         if (reportID)
 358                 args[index++] = reportID;
 359
 360         memcpy(&args[index], buf, data_len);
 361
 362         ret = __i2c_hid_command(ihid, hidcmd, reportID,
 363                 reportType, args, args_len, NULL, 0);
 364         if (ret) {
 365                 dev_err(&ihid->client->dev,
 366                         "failed to set a report to device.\n");
 367                 return ret;
 368         }
 369
 370         return data_len;
 371 }
 372
 373 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
 374 {
 375         int ret;
 376
 377         i2c_hid_dbg(ihid, "%s\n", __func__);
 378
 379         /*
 380          * Some devices require to send a command to wakeup before power on.
 381          * The call will get a return value (EREMOTEIO) but device will be
 382          * triggered and activated. After that, it goes like a normal device.
 383          */
 384         if (power_state == I2C_HID_PWR_ON &&
 385             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 386                 ret = i2c_hid_command(ihid, &hid_set_power_cmd, NULL, 0);
 387
 388                 /* Device was already activated */
 389                 if (!ret)
 390                         goto set_pwr_exit;
 391         }
 392
 393         ret = __i2c_hid_command(ihid, &hid_set_power_cmd, power_state,
 394                 0, NULL, 0, NULL, 0);
 395         if (ret)
 396                 dev_err(&ihid->client->dev,
 397                         "failed to change power setting.\n");
 398
 399 set_pwr_exit:
 400
 401         /*
 402          * The HID over I2C specification states that if a DEVICE needs time
 403          * after the PWR_ON request, it should utilise CLOCK stretching.
 404          * However, it has been observered that the Windows driver provides a
 405          * 1ms sleep between the PWR_ON and RESET requests.
 406          * According to Goodix Windows even waits 60 ms after (other?)
 407          * PWR_ON requests. Testing has confirmed that several devices
 408          * will not work properly without a delay after a PWR_ON request.
 409          */
 410         if (!ret && power_state == I2C_HID_PWR_ON)
 411                 msleep(60);
 412
 413         return ret;
 414 }
 415
 416 static int i2c_hid_execute_reset(struct i2c_hid *ihid)
 417 {
 418         int ret;
 419
 420         i2c_hid_dbg(ihid, "resetting...\n");
 421
 422         set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 423
 424         ret = i2c_hid_command(ihid, &hid_reset_cmd, NULL, 0);
 425         if (ret) {
 426                 dev_err(&ihid->client->dev, "failed to reset device.\n");
 427                 goto out;
 428         }
 429
 430         if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
 431                 msleep(100);
 432                 goto out;
 433         }
 434
 435         i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 436         if (!wait_event_timeout(ihid->wait,
 437                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 438                                 msecs_to_jiffies(5000))) {
 439                 ret = -ENODATA;
 440                 goto out;
 441         }
 442         i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 443
 444 out:
 445         clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 446         return ret;
 447 }
 448
 449 static int i2c_hid_hwreset(struct i2c_hid *ihid)
 450 {
 451         int ret;
 452
 453         i2c_hid_dbg(ihid, "%s\n", __func__);
 454
 455         /*
 456          * This prevents sending feature reports while the device is
 457          * being reset. Otherwise we may lose the reset complete
 458          * interrupt.
 459          */
 460         mutex_lock(&ihid->reset_lock);
 461
 462         ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 463         if (ret)
 464                 goto out_unlock;
 465
 466         ret = i2c_hid_execute_reset(ihid);
 467         if (ret) {
 468                 dev_err(&ihid->client->dev,
 469                         "failed to reset device: %d\n", ret);
 470                 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 471                 goto out_unlock;
 472         }
 473
 474         /* At least some SIS devices need this after reset */
 475         if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
 476                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 477
 478 out_unlock:
 479         mutex_unlock(&ihid->reset_lock);
 480         return ret;
 481 }
 482
 483 static void i2c_hid_get_input(struct i2c_hid *ihid)
 484 {
 485         int ret;
 486         u32 ret_size;
 487         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 488
 489         if (size > ihid->bufsize)
 490                 size = ihid->bufsize;
 491
 492         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 493         if (ret != size) {
 494                 if (ret < 0)
 495                         return;
 496
 497                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 498                         __func__, ret, size);
 499                 return;
 500         }
 501
 502         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 503
 504         if (!ret_size) {
 505                 /* host or device initiated RESET completed */
 506                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 507                         wake_up(&ihid->wait);
 508                 return;
 509         }
 510
 511         if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
 512                 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
 513                               "there's no data\n", __func__);
 514                 return;
 515         }
 516
 517         if ((ret_size > size) || (ret_size < 2)) {
 518                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 519                         ihid->inbuf[0] = size & 0xff;
 520                         ihid->inbuf[1] = size >> 8;
 521                         ret_size = size;
 522                 } else {
 523                         dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 524                                 __func__, size, ret_size);
 525                         return;
 526                 }
 527         }
 528
 529         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 530
 531         if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
 532                 pm_wakeup_event(&ihid->client->dev, 0);
 533
 534                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 535                                 ret_size - 2, 1);
 536         }
 537
 538         return;
 539 }
 540
 541 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 542 {
 543         struct i2c_hid *ihid = dev_id;
 544
 545         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 546                 return IRQ_HANDLED;
 547
 548         i2c_hid_get_input(ihid);
 549
 550         return IRQ_HANDLED;
 551 }
 552
 553 static int i2c_hid_get_report_length(struct hid_report *report)
 554 {
 555         return ((report->size - 1) >> 3) + 1 +
 556                 report->device->report_enum[report->type].numbered + 2;
 557 }
 558
 559 /*
 560  * Traverse the supplied list of reports and find the longest
 561  */
 562 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 563                 unsigned int *max)
 564 {
 565         struct hid_report *report;
 566         unsigned int size;
 567
 568         /* We should not rely on wMaxInputLength, as some devices may set it to
 569          * a wrong length. */
 570         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 571                 size = i2c_hid_get_report_length(report);
 572                 if (*max < size)
 573                         *max = size;
 574         }
 575 }
 576
 577 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 578 {
 579         kfree(ihid->inbuf);
 580         kfree(ihid->rawbuf);
 581         kfree(ihid->argsbuf);
 582         kfree(ihid->cmdbuf);
 583         ihid->inbuf = NULL;
 584         ihid->rawbuf = NULL;
 585         ihid->cmdbuf = NULL;
 586         ihid->argsbuf = NULL;
 587         ihid->bufsize = 0;
 588 }
 589
 590 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 591 {
 592         /* the worst case is computed from the set_report command with a
 593          * reportID > 15 and the maximum report length */
 594         int args_len = sizeof(__u8) + /* ReportID */
 595                        sizeof(__u8) + /* optional ReportID byte */
 596                        sizeof(__u16) + /* data register */
 597                        sizeof(__u16) + /* size of the report */
 598                        report_size; /* report */
 599
 600         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 601         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 602         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 603         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 604
 605         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 606                 i2c_hid_free_buffers(ihid);
 607                 return -ENOMEM;
 608         }
 609
 610         ihid->bufsize = report_size;
 611
 612         return 0;
 613 }
 614
 615 static int i2c_hid_get_raw_report(struct hid_device *hid,
 616                 unsigned char report_number, __u8 *buf, size_t count,
 617                 unsigned char report_type)
 618 {
 619         struct i2c_client *client = hid->driver_data;
 620         struct i2c_hid *ihid = i2c_get_clientdata(client);
 621         size_t ret_count, ask_count;
 622         int ret;
 623
 624         if (report_type == HID_OUTPUT_REPORT)
 625                 return -EINVAL;
 626
 627         /*
 628          * In case of unnumbered reports the response from the device will
 629          * not have the report ID that the upper layers expect, so we need
 630          * to stash it the buffer ourselves and adjust the data size.
 631          */
 632         if (!report_number) {
 633                 buf[0] = 0;
 634                 buf++;
 635                 count--;
 636         }
 637
 638         /* +2 bytes to include the size of the reply in the query buffer */
 639         ask_count = min(count + 2, (size_t)ihid->bufsize);
 640
 641         ret = i2c_hid_get_report(ihid,
 642                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 643                         report_number, ihid->rawbuf, ask_count);
 644
 645         if (ret < 0)
 646                 return ret;
 647
 648         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 649
 650         if (ret_count <= 2)
 651                 return 0;
 652
 653         ret_count = min(ret_count, ask_count);
 654
 655         /* The query buffer contains the size, dropping it in the reply */
 656         count = min(count, ret_count - 2);
 657         memcpy(buf, ihid->rawbuf + 2, count);
 658
 659         if (!report_number)
 660                 count++;
 661
 662         return count;
 663 }
 664
 665 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 666                 size_t count, unsigned char report_type, bool use_data)
 667 {
 668         struct i2c_client *client = hid->driver_data;
 669         struct i2c_hid *ihid = i2c_get_clientdata(client);
 670         int report_id = buf[0];
 671         int ret;
 672
 673         if (report_type == HID_INPUT_REPORT)
 674                 return -EINVAL;
 675
 676         mutex_lock(&ihid->reset_lock);
 677
 678         /*
 679          * Note that both numbered and unnumbered reports passed here
 680          * are supposed to have report ID stored in the 1st byte of the
 681          * buffer, so we strip it off unconditionally before passing payload
 682          * to i2c_hid_set_or_send_report which takes care of encoding
 683          * everything properly.
 684          */
 685         ret = i2c_hid_set_or_send_report(ihid,
 686                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 687                                 report_id, buf + 1, count - 1, use_data);
 688
 689         if (ret >= 0)
 690                 ret++; /* add report_id to the number of transferred bytes */
 691
 692         mutex_unlock(&ihid->reset_lock);
 693
 694         return ret;
 695 }
 696
 697 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 698                 size_t count)
 699 {
 700         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 701                         false);
 702 }
 703
 704 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 705                                __u8 *buf, size_t len, unsigned char rtype,
 706                                int reqtype)
 707 {
 708         switch (reqtype) {
 709         case HID_REQ_GET_REPORT:
 710                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 711         case HID_REQ_SET_REPORT:
 712                 if (buf[0] != reportnum)
 713                         return -EINVAL;
 714                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 715         default:
 716                 return -EIO;
 717         }
 718 }
 719
 720 static int i2c_hid_parse(struct hid_device *hid)
 721 {
 722         struct i2c_client *client = hid->driver_data;
 723         struct i2c_hid *ihid = i2c_get_clientdata(client);
 724         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 725         unsigned int rsize;
 726         char *rdesc;
 727         int ret;
 728         int tries = 3;
 729         char *use_override;
 730
 731         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 732
 733         rsize = le16_to_cpu(hdesc->wReportDescLength);
 734         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 735                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 736                 return -EINVAL;
 737         }
 738
 739         do {
 740                 ret = i2c_hid_hwreset(ihid);
 741                 if (ret)
 742                         msleep(1000);
 743         } while (tries-- > 0 && ret);
 744
 745         if (ret)
 746                 return ret;
 747
 748         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 749                                                                 &rsize);
 750
 751         if (use_override) {
 752                 rdesc = use_override;
 753                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 754         } else {
 755                 rdesc = kzalloc(rsize, GFP_KERNEL);
 756
 757                 if (!rdesc) {
 758                         dbg_hid("couldn't allocate rdesc memory\n");
 759                         return -ENOMEM;
 760                 }
 761
 762                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 763
 764                 ret = i2c_hid_command(ihid, &hid_report_descr_cmd,
 765                                       rdesc, rsize);
 766                 if (ret) {
 767                         hid_err(hid, "reading report descriptor failed\n");
 768                         kfree(rdesc);
 769                         return -EIO;
 770                 }
 771         }
 772
 773         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 774
 775         ret = hid_parse_report(hid, rdesc, rsize);
 776         if (!use_override)
 777                 kfree(rdesc);
 778
 779         if (ret) {
 780                 dbg_hid("parsing report descriptor failed\n");
 781                 return ret;
 782         }
 783
 784         return 0;
 785 }
 786
 787 static int i2c_hid_start(struct hid_device *hid)
 788 {
 789         struct i2c_client *client = hid->driver_data;
 790         struct i2c_hid *ihid = i2c_get_clientdata(client);
 791         int ret;
 792         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 793
 794         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 795         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 796         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 797
 798         if (bufsize > ihid->bufsize) {
 799                 disable_irq(client->irq);
 800                 i2c_hid_free_buffers(ihid);
 801
 802                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 803                 enable_irq(client->irq);
 804
 805                 if (ret)
 806                         return ret;
 807         }
 808
 809         return 0;
 810 }
 811
 812 static void i2c_hid_stop(struct hid_device *hid)
 813 {
 814         hid->claimed = 0;
 815 }
 816
 817 static int i2c_hid_open(struct hid_device *hid)
 818 {
 819         struct i2c_client *client = hid->driver_data;
 820         struct i2c_hid *ihid = i2c_get_clientdata(client);
 821
 822         set_bit(I2C_HID_STARTED, &ihid->flags);
 823         return 0;
 824 }
 825
 826 static void i2c_hid_close(struct hid_device *hid)
 827 {
 828         struct i2c_client *client = hid->driver_data;
 829         struct i2c_hid *ihid = i2c_get_clientdata(client);
 830
 831         clear_bit(I2C_HID_STARTED, &ihid->flags);
 832 }
 833
 834 struct hid_ll_driver i2c_hid_ll_driver = {
 835         .parse = i2c_hid_parse,
 836         .start = i2c_hid_start,
 837         .stop = i2c_hid_stop,
 838         .open = i2c_hid_open,
 839         .close = i2c_hid_close,
 840         .output_report = i2c_hid_output_report,
 841         .raw_request = i2c_hid_raw_request,
 842 };
 843 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 844
 845 static int i2c_hid_init_irq(struct i2c_client *client)
 846 {
 847         struct i2c_hid *ihid = i2c_get_clientdata(client);
 848         unsigned long irqflags = 0;
 849         int ret;
 850
 851         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 852
 853         if (!irq_get_trigger_type(client->irq))
 854                 irqflags = IRQF_TRIGGER_LOW;
 855
 856         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 857                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 858         if (ret < 0) {
 859                 dev_warn(&client->dev,
 860                         "Could not register for %s interrupt, irq = %d,"
 861                         " ret = %d\n",
 862                         client->name, client->irq, ret);
 863
 864                 return ret;
 865         }
 866
 867         return 0;
 868 }
 869
 870 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 871 {
 872         struct i2c_client *client = ihid->client;
 873         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 874         unsigned int dsize;
 875         int ret;
 876
 877         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 878         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 879                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 880                 ihid->hdesc =
 881                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 882         } else {
 883                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 884                 ret = i2c_hid_command(ihid, &hid_descr_cmd,
 885                                       ihid->hdesc_buffer,
 886                                       sizeof(struct i2c_hid_desc));
 887                 if (ret) {
 888                         dev_err(&ihid->client->dev, "hid_descr_cmd failed\n");
 889                         return -ENODEV;
 890                 }
 891         }
 892
 893         /* Validate the length of HID descriptor, the 4 first bytes:
 894          * bytes 0-1 -> length
 895          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 896         /* check bcdVersion == 1.0 */
 897         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 898                 dev_err(&ihid->client->dev,
 899                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 900                         le16_to_cpu(hdesc->bcdVersion));
 901                 return -ENODEV;
 902         }
 903
 904         /* Descriptor length should be 30 bytes as per the specification */
 905         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 906         if (dsize != sizeof(struct i2c_hid_desc)) {
 907                 dev_err(&ihid->client->dev,
 908                         "weird size of HID descriptor (%u)\n", dsize);
 909                 return -ENODEV;
 910         }
 911         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 912         return 0;
 913 }
 914
 915 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 916 {
 917         if (!ihid->ops->power_up)
 918                 return 0;
 919
 920         return ihid->ops->power_up(ihid->ops);
 921 }
 922
 923 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 924 {
 925         if (!ihid->ops->power_down)
 926                 return;
 927
 928         ihid->ops->power_down(ihid->ops);
 929 }
 930
 931 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 932 {
 933         if (!ihid->ops->shutdown_tail)
 934                 return;
 935
 936         ihid->ops->shutdown_tail(ihid->ops);
 937 }
 938
 939 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 940                        u16 hid_descriptor_address, u32 quirks)
 941 {
 942         int ret;
 943         struct i2c_hid *ihid;
 944         struct hid_device *hid;
 945
 946         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 947
 948         if (!client->irq) {
 949                 dev_err(&client->dev,
 950                         "HID over i2c has not been provided an Int IRQ\n");
 951                 return -EINVAL;
 952         }
 953
 954         if (client->irq < 0) {
 955                 if (client->irq != -EPROBE_DEFER)
 956                         dev_err(&client->dev,
 957                                 "HID over i2c doesn't have a valid IRQ\n");
 958                 return client->irq;
 959         }
 960
 961         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 962         if (!ihid)
 963                 return -ENOMEM;
 964
 965         ihid->ops = ops;
 966
 967         ret = i2c_hid_core_power_up(ihid);
 968         if (ret)
 969                 return ret;
 970
 971         i2c_set_clientdata(client, ihid);
 972
 973         ihid->client = client;
 974
 975         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 976
 977         init_waitqueue_head(&ihid->wait);
 978         mutex_init(&ihid->reset_lock);
 979
 980         /* we need to allocate the command buffer without knowing the maximum
 981          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 982          * real computation later. */
 983         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 984         if (ret < 0)
 985                 goto err_powered;
 986
 987         device_enable_async_suspend(&client->dev);
 988
 989         /* Make sure there is something at this address */
 990         ret = i2c_smbus_read_byte(client);
 991         if (ret < 0) {
 992                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
 993                 ret = -ENXIO;
 994                 goto err_powered;
 995         }
 996
 997         ret = i2c_hid_fetch_hid_descriptor(ihid);
 998         if (ret < 0) {
 999                 dev_err(&client->dev,
1000                         "Failed to fetch the HID Descriptor\n");
1001                 goto err_powered;
1002         }
1003
1004         ret = i2c_hid_init_irq(client);
1005         if (ret < 0)
1006                 goto err_powered;
1007
1008         hid = hid_allocate_device();
1009         if (IS_ERR(hid)) {
1010                 ret = PTR_ERR(hid);
1011                 goto err_irq;
1012         }
1013
1014         ihid->hid = hid;
1015
1016         hid->driver_data = client;
1017         hid->ll_driver = &i2c_hid_ll_driver;
1018         hid->dev.parent = &client->dev;
1019         hid->bus = BUS_I2C;
1020         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1021         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1022         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1023
1024         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1025                  client->name, (u16)hid->vendor, (u16)hid->product);
1026         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1027
1028         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1029
1030         ret = hid_add_device(hid);
1031         if (ret) {
1032                 if (ret != -ENODEV)
1033                         hid_err(client, "can't add hid device: %d\n", ret);
1034                 goto err_mem_free;
1035         }
1036
1037         hid->quirks |= quirks;
1038
1039         return 0;
1040
1041 err_mem_free:
1042         hid_destroy_device(hid);
1043
1044 err_irq:
1045         free_irq(client->irq, ihid);
1046
1047 err_powered:
1048         i2c_hid_core_power_down(ihid);
1049         i2c_hid_free_buffers(ihid);
1050         return ret;
1051 }
1052 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1053
1054 int i2c_hid_core_remove(struct i2c_client *client)
1055 {
1056         struct i2c_hid *ihid = i2c_get_clientdata(client);
1057         struct hid_device *hid;
1058
1059         hid = ihid->hid;
1060         hid_destroy_device(hid);
1061
1062         free_irq(client->irq, ihid);
1063
1064         if (ihid->bufsize)
1065                 i2c_hid_free_buffers(ihid);
1066
1067         i2c_hid_core_power_down(ihid);
1068
1069         return 0;
1070 }
1071 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1072
1073 void i2c_hid_core_shutdown(struct i2c_client *client)
1074 {
1075         struct i2c_hid *ihid = i2c_get_clientdata(client);
1076
1077         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1078         free_irq(client->irq, ihid);
1079
1080         i2c_hid_core_shutdown_tail(ihid);
1081 }
1082 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1083
1084 #ifdef CONFIG_PM_SLEEP
1085 static int i2c_hid_core_suspend(struct device *dev)
1086 {
1087         struct i2c_client *client = to_i2c_client(dev);
1088         struct i2c_hid *ihid = i2c_get_clientdata(client);
1089         struct hid_device *hid = ihid->hid;
1090         int ret;
1091         int wake_status;
1092
1093         ret = hid_driver_suspend(hid, PMSG_SUSPEND);
1094         if (ret < 0)
1095                 return ret;
1096
1097         /* Save some power */
1098         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1099
1100         disable_irq(client->irq);
1101
1102         if (device_may_wakeup(&client->dev)) {
1103                 wake_status = enable_irq_wake(client->irq);
1104                 if (!wake_status)
1105                         ihid->irq_wake_enabled = true;
1106                 else
1107                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1108                                 wake_status);
1109         } else {
1110                 i2c_hid_core_power_down(ihid);
1111         }
1112
1113         return 0;
1114 }
1115
1116 static int i2c_hid_core_resume(struct device *dev)
1117 {
1118         int ret;
1119         struct i2c_client *client = to_i2c_client(dev);
1120         struct i2c_hid *ihid = i2c_get_clientdata(client);
1121         struct hid_device *hid = ihid->hid;
1122         int wake_status;
1123
1124         if (!device_may_wakeup(&client->dev)) {
1125                 i2c_hid_core_power_up(ihid);
1126         } else if (ihid->irq_wake_enabled) {
1127                 wake_status = disable_irq_wake(client->irq);
1128                 if (!wake_status)
1129                         ihid->irq_wake_enabled = false;
1130                 else
1131                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1132                                 wake_status);
1133         }
1134
1135         enable_irq(client->irq);
1136
1137         /* Instead of resetting device, simply powers the device on. This
1138          * solves "incomplete reports" on Raydium devices 2386:3118 and
1139          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1140          * data after a suspend/resume.
1141          *
1142          * However some ALPS touchpads generate IRQ storm without reset, so
1143          * let's still reset them here.
1144          */
1145         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1146                 ret = i2c_hid_hwreset(ihid);
1147         else
1148                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1149
1150         if (ret)
1151                 return ret;
1152
1153         return hid_driver_reset_resume(hid);
1154 }
1155 #endif
1156
1157 const struct dev_pm_ops i2c_hid_core_pm = {
1158         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1159 };
1160 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1161
1162 MODULE_DESCRIPTION("HID over I2C core driver");
1163 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1164 MODULE_LICENSE("GPL");