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         bool wait;
  92 };
  93
  94 union command {
  95         u8 data[0];
  96         struct cmd {
  97                 __le16 reg;
  98                 __u8 reportTypeID;
  99                 __u8 opcode;
 100                 __u8 reportID;
 101         } __packed c;
 102 };
 103
 104 #define I2C_HID_CMD(opcode_) \
 105         .opcode = opcode_, .length = 4, \
 106         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 107
 108 /* fetch HID descriptor */
 109 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 110 /* fetch report descriptors */
 111 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 112                 .registerIndex = offsetof(struct i2c_hid_desc,
 113                         wReportDescRegister),
 114                 .opcode = 0x00,
 115                 .length = 2 };
 116 /* commands */
 117 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 118                                                           .wait = true };
 119 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 120 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 121 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 122 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 123
 124 /*
 125  * These definitions are not used here, but are defined by the spec.
 126  * Keeping them here for documentation purposes.
 127  *
 128  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 129  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 130  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 131  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 132  */
 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         u8                      *inbuf;         /* Input buffer */
 147         u8                      *rawbuf;        /* Raw Input buffer */
 148         u8                      *cmdbuf;        /* Command buffer */
 149         u8                      *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         bool                    irq_wake_enabled;
 157         struct mutex            reset_lock;
 158
 159         struct i2chid_ops       *ops;
 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, HID_ANY_ID,
 168                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 169         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 170                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 171         { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
 172                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 173         { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
 174                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 175         { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
 176                  I2C_HID_QUIRK_RESET_ON_RESUME },
 177         { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
 178                  I2C_HID_QUIRK_RESET_ON_RESUME },
 179         { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 180                 I2C_HID_QUIRK_BAD_INPUT_SIZE },
 181         /*
 182          * Sending the wakeup after reset actually break ELAN touchscreen controller
 183          */
 184         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 185                  I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 186                  I2C_HID_QUIRK_BOGUS_IRQ },
 187         { 0, 0 }
 188 };
 189
 190 /*
 191  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 192  * @idVendor: the 16-bit vendor ID
 193  * @idProduct: the 16-bit product ID
 194  *
 195  * Returns: a u32 quirks value.
 196  */
 197 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 198 {
 199         u32 quirks = 0;
 200         int n;
 201
 202         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 203                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 204                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 205                      i2c_hid_quirks[n].idProduct == idProduct))
 206                         quirks = i2c_hid_quirks[n].quirks;
 207
 208         return quirks;
 209 }
 210
 211 static int __i2c_hid_command(struct i2c_client *client,
 212                 const struct i2c_hid_cmd *command, u8 reportID,
 213                 u8 reportType, u8 *args, int args_len,
 214                 unsigned char *buf_recv, int data_len)
 215 {
 216         struct i2c_hid *ihid = i2c_get_clientdata(client);
 217         union command *cmd = (union command *)ihid->cmdbuf;
 218         int ret;
 219         struct i2c_msg msg[2];
 220         int msg_num = 1;
 221
 222         int length = command->length;
 223         bool wait = command->wait;
 224         unsigned int registerIndex = command->registerIndex;
 225
 226         /* special case for hid_descr_cmd */
 227         if (command == &hid_descr_cmd) {
 228                 cmd->c.reg = ihid->wHIDDescRegister;
 229         } else {
 230                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 231                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 232         }
 233
 234         if (length > 2) {
 235                 cmd->c.opcode = command->opcode;
 236                 if (reportID < 0x0F) {
 237                         cmd->c.reportTypeID = reportType << 4 | reportID;
 238                 } else {
 239                         cmd->c.reportTypeID = reportType << 4 | 0x0F;
 240                         cmd->c.reportID = reportID;
 241                         length++;
 242                 }
 243         }
 244
 245         memcpy(cmd->data + length, args, args_len);
 246         length += args_len;
 247
 248         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 249
 250         msg[0].addr = client->addr;
 251         msg[0].flags = client->flags & I2C_M_TEN;
 252         msg[0].len = length;
 253         msg[0].buf = cmd->data;
 254         if (data_len > 0) {
 255                 msg[1].addr = client->addr;
 256                 msg[1].flags = client->flags & I2C_M_TEN;
 257                 msg[1].flags |= I2C_M_RD;
 258                 msg[1].len = data_len;
 259                 msg[1].buf = buf_recv;
 260                 msg_num = 2;
 261                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 262         }
 263
 264         if (wait)
 265                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 266
 267         ret = i2c_transfer(client->adapter, msg, msg_num);
 268
 269         if (data_len > 0)
 270                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 271
 272         if (ret != msg_num)
 273                 return ret < 0 ? ret : -EIO;
 274
 275         ret = 0;
 276
 277         if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
 278                 msleep(100);
 279         } else if (wait) {
 280                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 281                 if (!wait_event_timeout(ihid->wait,
 282                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 283                                 msecs_to_jiffies(5000)))
 284                         ret = -ENODATA;
 285                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 286         }
 287
 288         return ret;
 289 }
 290
 291 static int i2c_hid_command(struct i2c_client *client,
 292                 const struct i2c_hid_cmd *command,
 293                 unsigned char *buf_recv, int data_len)
 294 {
 295         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 296                                 buf_recv, data_len);
 297 }
 298
 299 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 300                 u8 reportID, unsigned char *buf_recv, int data_len)
 301 {
 302         struct i2c_hid *ihid = i2c_get_clientdata(client);
 303         u8 args[2];
 304         int ret;
 305         int args_len = 0;
 306         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 307
 308         i2c_hid_dbg(ihid, "%s\n", __func__);
 309
 310         args[args_len++] = readRegister & 0xFF;
 311         args[args_len++] = readRegister >> 8;
 312
 313         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 314                 reportType, args, args_len, buf_recv, data_len);
 315         if (ret) {
 316                 dev_err(&client->dev,
 317                         "failed to retrieve report from device.\n");
 318                 return ret;
 319         }
 320
 321         return 0;
 322 }
 323
 324 /**
 325  * i2c_hid_set_or_send_report: forward an incoming report to the device
 326  * @client: the i2c_client of the device
 327  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 328  * @reportID: the report ID
 329  * @buf: the actual data to transfer, without the report ID
 330  * @data_len: size of buf
 331  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 332  */
 333 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 334                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 335 {
 336         struct i2c_hid *ihid = i2c_get_clientdata(client);
 337         u8 *args = ihid->argsbuf;
 338         const struct i2c_hid_cmd *hidcmd;
 339         int ret;
 340         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 341         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 342         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 343         u16 size;
 344         int args_len;
 345         int index = 0;
 346
 347         i2c_hid_dbg(ihid, "%s\n", __func__);
 348
 349         if (data_len > ihid->bufsize)
 350                 return -EINVAL;
 351
 352         size =          2                       /* size */ +
 353                         (reportID ? 1 : 0)      /* reportID */ +
 354                         data_len                /* buf */;
 355         args_len =      2                       /* dataRegister */ +
 356                         size                    /* args */;
 357
 358         if (!use_data && maxOutputLength == 0)
 359                 return -ENOSYS;
 360
 361         /*
 362          * use the data register for feature reports or if the device does not
 363          * support the output register
 364          */
 365         if (use_data) {
 366                 args[index++] = dataRegister & 0xFF;
 367                 args[index++] = dataRegister >> 8;
 368                 hidcmd = &hid_set_report_cmd;
 369         } else {
 370                 args[index++] = outputRegister & 0xFF;
 371                 args[index++] = outputRegister >> 8;
 372                 hidcmd = &hid_no_cmd;
 373         }
 374
 375         args[index++] = size & 0xFF;
 376         args[index++] = size >> 8;
 377
 378         if (reportID)
 379                 args[index++] = reportID;
 380
 381         memcpy(&args[index], buf, data_len);
 382
 383         ret = __i2c_hid_command(client, hidcmd, reportID,
 384                 reportType, args, args_len, NULL, 0);
 385         if (ret) {
 386                 dev_err(&client->dev, "failed to set a report to device.\n");
 387                 return ret;
 388         }
 389
 390         return data_len;
 391 }
 392
 393 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 394 {
 395         struct i2c_hid *ihid = i2c_get_clientdata(client);
 396         int ret;
 397
 398         i2c_hid_dbg(ihid, "%s\n", __func__);
 399
 400         /*
 401          * Some devices require to send a command to wakeup before power on.
 402          * The call will get a return value (EREMOTEIO) but device will be
 403          * triggered and activated. After that, it goes like a normal device.
 404          */
 405         if (power_state == I2C_HID_PWR_ON &&
 406             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 407                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
 408
 409                 /* Device was already activated */
 410                 if (!ret)
 411                         goto set_pwr_exit;
 412         }
 413
 414         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 415                 0, NULL, 0, NULL, 0);
 416
 417         if (ret)
 418                 dev_err(&client->dev, "failed to change power setting.\n");
 419
 420 set_pwr_exit:
 421
 422         /*
 423          * The HID over I2C specification states that if a DEVICE needs time
 424          * after the PWR_ON request, it should utilise CLOCK stretching.
 425          * However, it has been observered that the Windows driver provides a
 426          * 1ms sleep between the PWR_ON and RESET requests.
 427          * According to Goodix Windows even waits 60 ms after (other?)
 428          * PWR_ON requests. Testing has confirmed that several devices
 429          * will not work properly without a delay after a PWR_ON request.
 430          */
 431         if (!ret && power_state == I2C_HID_PWR_ON)
 432                 msleep(60);
 433
 434         return ret;
 435 }
 436
 437 static int i2c_hid_hwreset(struct i2c_client *client)
 438 {
 439         struct i2c_hid *ihid = i2c_get_clientdata(client);
 440         int ret;
 441
 442         i2c_hid_dbg(ihid, "%s\n", __func__);
 443
 444         /*
 445          * This prevents sending feature reports while the device is
 446          * being reset. Otherwise we may lose the reset complete
 447          * interrupt.
 448          */
 449         mutex_lock(&ihid->reset_lock);
 450
 451         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 452         if (ret)
 453                 goto out_unlock;
 454
 455         i2c_hid_dbg(ihid, "resetting...\n");
 456
 457         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 458         if (ret) {
 459                 dev_err(&client->dev, "failed to reset device.\n");
 460                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 461                 goto out_unlock;
 462         }
 463
 464         /* At least some SIS devices need this after reset */
 465         if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
 466                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 467
 468 out_unlock:
 469         mutex_unlock(&ihid->reset_lock);
 470         return ret;
 471 }
 472
 473 static void i2c_hid_get_input(struct i2c_hid *ihid)
 474 {
 475         int ret;
 476         u32 ret_size;
 477         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 478
 479         if (size > ihid->bufsize)
 480                 size = ihid->bufsize;
 481
 482         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 483         if (ret != size) {
 484                 if (ret < 0)
 485                         return;
 486
 487                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 488                         __func__, ret, size);
 489                 return;
 490         }
 491
 492         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 493
 494         if (!ret_size) {
 495                 /* host or device initiated RESET completed */
 496                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 497                         wake_up(&ihid->wait);
 498                 return;
 499         }
 500
 501         if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
 502                 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
 503                               "there's no data\n", __func__);
 504                 return;
 505         }
 506
 507         if ((ret_size > size) || (ret_size < 2)) {
 508                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 509                         ihid->inbuf[0] = size & 0xff;
 510                         ihid->inbuf[1] = size >> 8;
 511                         ret_size = size;
 512                 } else {
 513                         dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 514                                 __func__, size, ret_size);
 515                         return;
 516                 }
 517         }
 518
 519         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 520
 521         if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
 522                 pm_wakeup_event(&ihid->client->dev, 0);
 523
 524                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 525                                 ret_size - 2, 1);
 526         }
 527
 528         return;
 529 }
 530
 531 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 532 {
 533         struct i2c_hid *ihid = dev_id;
 534
 535         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 536                 return IRQ_HANDLED;
 537
 538         i2c_hid_get_input(ihid);
 539
 540         return IRQ_HANDLED;
 541 }
 542
 543 static int i2c_hid_get_report_length(struct hid_report *report)
 544 {
 545         return ((report->size - 1) >> 3) + 1 +
 546                 report->device->report_enum[report->type].numbered + 2;
 547 }
 548
 549 /*
 550  * Traverse the supplied list of reports and find the longest
 551  */
 552 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 553                 unsigned int *max)
 554 {
 555         struct hid_report *report;
 556         unsigned int size;
 557
 558         /* We should not rely on wMaxInputLength, as some devices may set it to
 559          * a wrong length. */
 560         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 561                 size = i2c_hid_get_report_length(report);
 562                 if (*max < size)
 563                         *max = size;
 564         }
 565 }
 566
 567 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 568 {
 569         kfree(ihid->inbuf);
 570         kfree(ihid->rawbuf);
 571         kfree(ihid->argsbuf);
 572         kfree(ihid->cmdbuf);
 573         ihid->inbuf = NULL;
 574         ihid->rawbuf = NULL;
 575         ihid->cmdbuf = NULL;
 576         ihid->argsbuf = NULL;
 577         ihid->bufsize = 0;
 578 }
 579
 580 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 581 {
 582         /* the worst case is computed from the set_report command with a
 583          * reportID > 15 and the maximum report length */
 584         int args_len = sizeof(__u8) + /* ReportID */
 585                        sizeof(__u8) + /* optional ReportID byte */
 586                        sizeof(__u16) + /* data register */
 587                        sizeof(__u16) + /* size of the report */
 588                        report_size; /* report */
 589
 590         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 591         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 592         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 593         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 594
 595         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 596                 i2c_hid_free_buffers(ihid);
 597                 return -ENOMEM;
 598         }
 599
 600         ihid->bufsize = report_size;
 601
 602         return 0;
 603 }
 604
 605 static int i2c_hid_get_raw_report(struct hid_device *hid,
 606                 unsigned char report_number, __u8 *buf, size_t count,
 607                 unsigned char report_type)
 608 {
 609         struct i2c_client *client = hid->driver_data;
 610         struct i2c_hid *ihid = i2c_get_clientdata(client);
 611         size_t ret_count, ask_count;
 612         int ret;
 613
 614         if (report_type == HID_OUTPUT_REPORT)
 615                 return -EINVAL;
 616
 617         /*
 618          * In case of unnumbered reports the response from the device will
 619          * not have the report ID that the upper layers expect, so we need
 620          * to stash it the buffer ourselves and adjust the data size.
 621          */
 622         if (!report_number) {
 623                 buf[0] = 0;
 624                 buf++;
 625                 count--;
 626         }
 627
 628         /* +2 bytes to include the size of the reply in the query buffer */
 629         ask_count = min(count + 2, (size_t)ihid->bufsize);
 630
 631         ret = i2c_hid_get_report(client,
 632                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 633                         report_number, ihid->rawbuf, ask_count);
 634
 635         if (ret < 0)
 636                 return ret;
 637
 638         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 639
 640         if (ret_count <= 2)
 641                 return 0;
 642
 643         ret_count = min(ret_count, ask_count);
 644
 645         /* The query buffer contains the size, dropping it in the reply */
 646         count = min(count, ret_count - 2);
 647         memcpy(buf, ihid->rawbuf + 2, count);
 648
 649         if (!report_number)
 650                 count++;
 651
 652         return count;
 653 }
 654
 655 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 656                 size_t count, unsigned char report_type, bool use_data)
 657 {
 658         struct i2c_client *client = hid->driver_data;
 659         struct i2c_hid *ihid = i2c_get_clientdata(client);
 660         int report_id = buf[0];
 661         int ret;
 662
 663         if (report_type == HID_INPUT_REPORT)
 664                 return -EINVAL;
 665
 666         mutex_lock(&ihid->reset_lock);
 667
 668         /*
 669          * Note that both numbered and unnumbered reports passed here
 670          * are supposed to have report ID stored in the 1st byte of the
 671          * buffer, so we strip it off unconditionally before passing payload
 672          * to i2c_hid_set_or_send_report which takes care of encoding
 673          * everything properly.
 674          */
 675         ret = i2c_hid_set_or_send_report(client,
 676                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 677                                 report_id, buf + 1, count - 1, use_data);
 678
 679         if (ret >= 0)
 680                 ret++; /* add report_id to the number of transferred bytes */
 681
 682         mutex_unlock(&ihid->reset_lock);
 683
 684         return ret;
 685 }
 686
 687 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 688                 size_t count)
 689 {
 690         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 691                         false);
 692 }
 693
 694 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 695                                __u8 *buf, size_t len, unsigned char rtype,
 696                                int reqtype)
 697 {
 698         switch (reqtype) {
 699         case HID_REQ_GET_REPORT:
 700                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 701         case HID_REQ_SET_REPORT:
 702                 if (buf[0] != reportnum)
 703                         return -EINVAL;
 704                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 705         default:
 706                 return -EIO;
 707         }
 708 }
 709
 710 static int i2c_hid_parse(struct hid_device *hid)
 711 {
 712         struct i2c_client *client = hid->driver_data;
 713         struct i2c_hid *ihid = i2c_get_clientdata(client);
 714         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 715         unsigned int rsize;
 716         char *rdesc;
 717         int ret;
 718         int tries = 3;
 719         char *use_override;
 720
 721         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 722
 723         rsize = le16_to_cpu(hdesc->wReportDescLength);
 724         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 725                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 726                 return -EINVAL;
 727         }
 728
 729         do {
 730                 ret = i2c_hid_hwreset(client);
 731                 if (ret)
 732                         msleep(1000);
 733         } while (tries-- > 0 && ret);
 734
 735         if (ret)
 736                 return ret;
 737
 738         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 739                                                                 &rsize);
 740
 741         if (use_override) {
 742                 rdesc = use_override;
 743                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 744         } else {
 745                 rdesc = kzalloc(rsize, GFP_KERNEL);
 746
 747                 if (!rdesc) {
 748                         dbg_hid("couldn't allocate rdesc memory\n");
 749                         return -ENOMEM;
 750                 }
 751
 752                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 753
 754                 ret = i2c_hid_command(client, &hid_report_descr_cmd,
 755                                       rdesc, rsize);
 756                 if (ret) {
 757                         hid_err(hid, "reading report descriptor failed\n");
 758                         kfree(rdesc);
 759                         return -EIO;
 760                 }
 761         }
 762
 763         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 764
 765         ret = hid_parse_report(hid, rdesc, rsize);
 766         if (!use_override)
 767                 kfree(rdesc);
 768
 769         if (ret) {
 770                 dbg_hid("parsing report descriptor failed\n");
 771                 return ret;
 772         }
 773
 774         return 0;
 775 }
 776
 777 static int i2c_hid_start(struct hid_device *hid)
 778 {
 779         struct i2c_client *client = hid->driver_data;
 780         struct i2c_hid *ihid = i2c_get_clientdata(client);
 781         int ret;
 782         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 783
 784         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 785         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 786         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 787
 788         if (bufsize > ihid->bufsize) {
 789                 disable_irq(client->irq);
 790                 i2c_hid_free_buffers(ihid);
 791
 792                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 793                 enable_irq(client->irq);
 794
 795                 if (ret)
 796                         return ret;
 797         }
 798
 799         return 0;
 800 }
 801
 802 static void i2c_hid_stop(struct hid_device *hid)
 803 {
 804         hid->claimed = 0;
 805 }
 806
 807 static int i2c_hid_open(struct hid_device *hid)
 808 {
 809         struct i2c_client *client = hid->driver_data;
 810         struct i2c_hid *ihid = i2c_get_clientdata(client);
 811
 812         set_bit(I2C_HID_STARTED, &ihid->flags);
 813         return 0;
 814 }
 815
 816 static void i2c_hid_close(struct hid_device *hid)
 817 {
 818         struct i2c_client *client = hid->driver_data;
 819         struct i2c_hid *ihid = i2c_get_clientdata(client);
 820
 821         clear_bit(I2C_HID_STARTED, &ihid->flags);
 822 }
 823
 824 struct hid_ll_driver i2c_hid_ll_driver = {
 825         .parse = i2c_hid_parse,
 826         .start = i2c_hid_start,
 827         .stop = i2c_hid_stop,
 828         .open = i2c_hid_open,
 829         .close = i2c_hid_close,
 830         .output_report = i2c_hid_output_report,
 831         .raw_request = i2c_hid_raw_request,
 832 };
 833 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 834
 835 static int i2c_hid_init_irq(struct i2c_client *client)
 836 {
 837         struct i2c_hid *ihid = i2c_get_clientdata(client);
 838         unsigned long irqflags = 0;
 839         int ret;
 840
 841         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 842
 843         if (!irq_get_trigger_type(client->irq))
 844                 irqflags = IRQF_TRIGGER_LOW;
 845
 846         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 847                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 848         if (ret < 0) {
 849                 dev_warn(&client->dev,
 850                         "Could not register for %s interrupt, irq = %d,"
 851                         " ret = %d\n",
 852                         client->name, client->irq, ret);
 853
 854                 return ret;
 855         }
 856
 857         return 0;
 858 }
 859
 860 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 861 {
 862         struct i2c_client *client = ihid->client;
 863         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 864         unsigned int dsize;
 865         int ret;
 866
 867         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 868         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 869                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 870                 ihid->hdesc =
 871                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 872         } else {
 873                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 874                 ret = i2c_hid_command(client, &hid_descr_cmd,
 875                                       ihid->hdesc_buffer,
 876                                       sizeof(struct i2c_hid_desc));
 877                 if (ret) {
 878                         dev_err(&client->dev, "hid_descr_cmd failed\n");
 879                         return -ENODEV;
 880                 }
 881         }
 882
 883         /* Validate the length of HID descriptor, the 4 first bytes:
 884          * bytes 0-1 -> length
 885          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 886         /* check bcdVersion == 1.0 */
 887         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 888                 dev_err(&client->dev,
 889                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 890                         le16_to_cpu(hdesc->bcdVersion));
 891                 return -ENODEV;
 892         }
 893
 894         /* Descriptor length should be 30 bytes as per the specification */
 895         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 896         if (dsize != sizeof(struct i2c_hid_desc)) {
 897                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 898                         dsize);
 899                 return -ENODEV;
 900         }
 901         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 902         return 0;
 903 }
 904
 905 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 906 {
 907         if (!ihid->ops->power_up)
 908                 return 0;
 909
 910         return ihid->ops->power_up(ihid->ops);
 911 }
 912
 913 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 914 {
 915         if (!ihid->ops->power_down)
 916                 return;
 917
 918         ihid->ops->power_down(ihid->ops);
 919 }
 920
 921 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 922 {
 923         if (!ihid->ops->shutdown_tail)
 924                 return;
 925
 926         ihid->ops->shutdown_tail(ihid->ops);
 927 }
 928
 929 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 930                        u16 hid_descriptor_address, u32 quirks)
 931 {
 932         int ret;
 933         struct i2c_hid *ihid;
 934         struct hid_device *hid;
 935
 936         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 937
 938         if (!client->irq) {
 939                 dev_err(&client->dev,
 940                         "HID over i2c has not been provided an Int IRQ\n");
 941                 return -EINVAL;
 942         }
 943
 944         if (client->irq < 0) {
 945                 if (client->irq != -EPROBE_DEFER)
 946                         dev_err(&client->dev,
 947                                 "HID over i2c doesn't have a valid IRQ\n");
 948                 return client->irq;
 949         }
 950
 951         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 952         if (!ihid)
 953                 return -ENOMEM;
 954
 955         ihid->ops = ops;
 956
 957         ret = i2c_hid_core_power_up(ihid);
 958         if (ret)
 959                 return ret;
 960
 961         i2c_set_clientdata(client, ihid);
 962
 963         ihid->client = client;
 964
 965         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 966
 967         init_waitqueue_head(&ihid->wait);
 968         mutex_init(&ihid->reset_lock);
 969
 970         /* we need to allocate the command buffer without knowing the maximum
 971          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 972          * real computation later. */
 973         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 974         if (ret < 0)
 975                 goto err_powered;
 976
 977         device_enable_async_suspend(&client->dev);
 978
 979         /* Make sure there is something at this address */
 980         ret = i2c_smbus_read_byte(client);
 981         if (ret < 0) {
 982                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
 983                 ret = -ENXIO;
 984                 goto err_powered;
 985         }
 986
 987         ret = i2c_hid_fetch_hid_descriptor(ihid);
 988         if (ret < 0) {
 989                 dev_err(&client->dev,
 990                         "Failed to fetch the HID Descriptor\n");
 991                 goto err_powered;
 992         }
 993
 994         ret = i2c_hid_init_irq(client);
 995         if (ret < 0)
 996                 goto err_powered;
 997
 998         hid = hid_allocate_device();
 999         if (IS_ERR(hid)) {
1000                 ret = PTR_ERR(hid);
1001                 goto err_irq;
1002         }
1003
1004         ihid->hid = hid;
1005
1006         hid->driver_data = client;
1007         hid->ll_driver = &i2c_hid_ll_driver;
1008         hid->dev.parent = &client->dev;
1009         hid->bus = BUS_I2C;
1010         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1011         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1012         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1013
1014         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1015                  client->name, (u16)hid->vendor, (u16)hid->product);
1016         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1017
1018         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1019
1020         ret = hid_add_device(hid);
1021         if (ret) {
1022                 if (ret != -ENODEV)
1023                         hid_err(client, "can't add hid device: %d\n", ret);
1024                 goto err_mem_free;
1025         }
1026
1027         hid->quirks |= quirks;
1028
1029         return 0;
1030
1031 err_mem_free:
1032         hid_destroy_device(hid);
1033
1034 err_irq:
1035         free_irq(client->irq, ihid);
1036
1037 err_powered:
1038         i2c_hid_core_power_down(ihid);
1039         i2c_hid_free_buffers(ihid);
1040         return ret;
1041 }
1042 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1043
1044 int i2c_hid_core_remove(struct i2c_client *client)
1045 {
1046         struct i2c_hid *ihid = i2c_get_clientdata(client);
1047         struct hid_device *hid;
1048
1049         hid = ihid->hid;
1050         hid_destroy_device(hid);
1051
1052         free_irq(client->irq, ihid);
1053
1054         if (ihid->bufsize)
1055                 i2c_hid_free_buffers(ihid);
1056
1057         i2c_hid_core_power_down(ihid);
1058
1059         return 0;
1060 }
1061 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1062
1063 void i2c_hid_core_shutdown(struct i2c_client *client)
1064 {
1065         struct i2c_hid *ihid = i2c_get_clientdata(client);
1066
1067         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1068         free_irq(client->irq, ihid);
1069
1070         i2c_hid_core_shutdown_tail(ihid);
1071 }
1072 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1073
1074 #ifdef CONFIG_PM_SLEEP
1075 static int i2c_hid_core_suspend(struct device *dev)
1076 {
1077         struct i2c_client *client = to_i2c_client(dev);
1078         struct i2c_hid *ihid = i2c_get_clientdata(client);
1079         struct hid_device *hid = ihid->hid;
1080         int ret;
1081         int wake_status;
1082
1083         ret = hid_driver_suspend(hid, PMSG_SUSPEND);
1084         if (ret < 0)
1085                 return ret;
1086
1087         /* Save some power */
1088         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1089
1090         disable_irq(client->irq);
1091
1092         if (device_may_wakeup(&client->dev)) {
1093                 wake_status = enable_irq_wake(client->irq);
1094                 if (!wake_status)
1095                         ihid->irq_wake_enabled = true;
1096                 else
1097                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1098                                 wake_status);
1099         } else {
1100                 i2c_hid_core_power_down(ihid);
1101         }
1102
1103         return 0;
1104 }
1105
1106 static int i2c_hid_core_resume(struct device *dev)
1107 {
1108         int ret;
1109         struct i2c_client *client = to_i2c_client(dev);
1110         struct i2c_hid *ihid = i2c_get_clientdata(client);
1111         struct hid_device *hid = ihid->hid;
1112         int wake_status;
1113
1114         if (!device_may_wakeup(&client->dev)) {
1115                 i2c_hid_core_power_up(ihid);
1116         } else if (ihid->irq_wake_enabled) {
1117                 wake_status = disable_irq_wake(client->irq);
1118                 if (!wake_status)
1119                         ihid->irq_wake_enabled = false;
1120                 else
1121                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1122                                 wake_status);
1123         }
1124
1125         enable_irq(client->irq);
1126
1127         /* Instead of resetting device, simply powers the device on. This
1128          * solves "incomplete reports" on Raydium devices 2386:3118 and
1129          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1130          * data after a suspend/resume.
1131          *
1132          * However some ALPS touchpads generate IRQ storm without reset, so
1133          * let's still reset them here.
1134          */
1135         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1136                 ret = i2c_hid_hwreset(client);
1137         else
1138                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
1139
1140         if (ret)
1141                 return ret;
1142
1143         return hid_driver_reset_resume(hid);
1144 }
1145 #endif
1146
1147 const struct dev_pm_ops i2c_hid_core_pm = {
1148         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1149 };
1150 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1151
1152 MODULE_DESCRIPTION("HID over I2C core driver");
1153 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1154 MODULE_LICENSE("GPL");