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         } __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                                                           .wait = true };
 118 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 119 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 120 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 121 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 122
 123 /*
 124  * These definitions are not used here, but are defined by the spec.
 125  * Keeping them here for documentation purposes.
 126  *
 127  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 128  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 129  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 130  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 131  */
 132
 133 /* The main device structure */
 134 struct i2c_hid {
 135         struct i2c_client       *client;        /* i2c client */
 136         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 137         union {
 138                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 139                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 140         };
 141         __le16                  wHIDDescRegister; /* location of the i2c
 142                                                    * register of the HID
 143                                                    * descriptor. */
 144         unsigned int            bufsize;        /* i2c buffer size */
 145         u8                      *inbuf;         /* Input buffer */
 146         u8                      *rawbuf;        /* Raw Input buffer */
 147         u8                      *cmdbuf;        /* Command buffer */
 148         u8                      *argsbuf;       /* Command arguments buffer */
 149
 150         unsigned long           flags;          /* device flags */
 151         unsigned long           quirks;         /* Various quirks */
 152
 153         wait_queue_head_t       wait;           /* For waiting the interrupt */
 154
 155         bool                    irq_wake_enabled;
 156         struct mutex            reset_lock;
 157
 158         struct i2chid_ops       *ops;
 159 };
 160
 161 static const struct i2c_hid_quirks {
 162         __u16 idVendor;
 163         __u16 idProduct;
 164         __u32 quirks;
 165 } i2c_hid_quirks[] = {
 166         { USB_VENDOR_ID_WEIDA, HID_ANY_ID,
 167                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 168         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 169                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 170         { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
 171                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 172         { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
 173                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 174         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 175                  I2C_HID_QUIRK_BOGUS_IRQ },
 176         { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
 177                  I2C_HID_QUIRK_RESET_ON_RESUME },
 178         { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
 179                  I2C_HID_QUIRK_RESET_ON_RESUME },
 180         { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 181                 I2C_HID_QUIRK_BAD_INPUT_SIZE },
 182         /*
 183          * Sending the wakeup after reset actually break ELAN touchscreen controller
 184          */
 185         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 186                  I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET },
 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                 cmd->c.reportTypeID = reportID | reportType << 4;
 237         }
 238
 239         memcpy(cmd->data + length, args, args_len);
 240         length += args_len;
 241
 242         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 243
 244         msg[0].addr = client->addr;
 245         msg[0].flags = client->flags & I2C_M_TEN;
 246         msg[0].len = length;
 247         msg[0].buf = cmd->data;
 248         if (data_len > 0) {
 249                 msg[1].addr = client->addr;
 250                 msg[1].flags = client->flags & I2C_M_TEN;
 251                 msg[1].flags |= I2C_M_RD;
 252                 msg[1].len = data_len;
 253                 msg[1].buf = buf_recv;
 254                 msg_num = 2;
 255                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 256         }
 257
 258         if (wait)
 259                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 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         ret = 0;
 270
 271         if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
 272                 msleep(100);
 273         } else if (wait) {
 274                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 275                 if (!wait_event_timeout(ihid->wait,
 276                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 277                                 msecs_to_jiffies(5000)))
 278                         ret = -ENODATA;
 279                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 280         }
 281
 282         return ret;
 283 }
 284
 285 static int i2c_hid_command(struct i2c_client *client,
 286                 const struct i2c_hid_cmd *command,
 287                 unsigned char *buf_recv, int data_len)
 288 {
 289         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 290                                 buf_recv, data_len);
 291 }
 292
 293 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 294                 u8 reportID, unsigned char *buf_recv, int data_len)
 295 {
 296         struct i2c_hid *ihid = i2c_get_clientdata(client);
 297         u8 args[3];
 298         int ret;
 299         int args_len = 0;
 300         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 301
 302         i2c_hid_dbg(ihid, "%s\n", __func__);
 303
 304         if (reportID >= 0x0F) {
 305                 args[args_len++] = reportID;
 306                 reportID = 0x0F;
 307         }
 308
 309         args[args_len++] = readRegister & 0xFF;
 310         args[args_len++] = readRegister >> 8;
 311
 312         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 313                 reportType, args, args_len, buf_recv, data_len);
 314         if (ret) {
 315                 dev_err(&client->dev,
 316                         "failed to retrieve report from device.\n");
 317                 return ret;
 318         }
 319
 320         return 0;
 321 }
 322
 323 /**
 324  * i2c_hid_set_or_send_report: forward an incoming report to the device
 325  * @client: the i2c_client of the device
 326  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 327  * @reportID: the report ID
 328  * @buf: the actual data to transfer, without the report ID
 329  * @data_len: size of buf
 330  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 331  */
 332 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 333                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 334 {
 335         struct i2c_hid *ihid = i2c_get_clientdata(client);
 336         u8 *args = ihid->argsbuf;
 337         const struct i2c_hid_cmd *hidcmd;
 338         int ret;
 339         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 340         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 341         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 342         u16 size;
 343         int args_len;
 344         int index = 0;
 345
 346         i2c_hid_dbg(ihid, "%s\n", __func__);
 347
 348         if (data_len > ihid->bufsize)
 349                 return -EINVAL;
 350
 351         size =          2                       /* size */ +
 352                         (reportID ? 1 : 0)      /* reportID */ +
 353                         data_len                /* buf */;
 354         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 355                         2                       /* dataRegister */ +
 356                         size                    /* args */;
 357
 358         if (!use_data && maxOutputLength == 0)
 359                 return -ENOSYS;
 360
 361         if (reportID >= 0x0F) {
 362                 args[index++] = reportID;
 363                 reportID = 0x0F;
 364         }
 365
 366         /*
 367          * use the data register for feature reports or if the device does not
 368          * support the output register
 369          */
 370         if (use_data) {
 371                 args[index++] = dataRegister & 0xFF;
 372                 args[index++] = dataRegister >> 8;
 373                 hidcmd = &hid_set_report_cmd;
 374         } else {
 375                 args[index++] = outputRegister & 0xFF;
 376                 args[index++] = outputRegister >> 8;
 377                 hidcmd = &hid_no_cmd;
 378         }
 379
 380         args[index++] = size & 0xFF;
 381         args[index++] = size >> 8;
 382
 383         if (reportID)
 384                 args[index++] = reportID;
 385
 386         memcpy(&args[index], buf, data_len);
 387
 388         ret = __i2c_hid_command(client, hidcmd, reportID,
 389                 reportType, args, args_len, NULL, 0);
 390         if (ret) {
 391                 dev_err(&client->dev, "failed to set a report to device.\n");
 392                 return ret;
 393         }
 394
 395         return data_len;
 396 }
 397
 398 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 399 {
 400         struct i2c_hid *ihid = i2c_get_clientdata(client);
 401         int ret;
 402
 403         i2c_hid_dbg(ihid, "%s\n", __func__);
 404
 405         /*
 406          * Some devices require to send a command to wakeup before power on.
 407          * The call will get a return value (EREMOTEIO) but device will be
 408          * triggered and activated. After that, it goes like a normal device.
 409          */
 410         if (power_state == I2C_HID_PWR_ON &&
 411             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 412                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
 413
 414                 /* Device was already activated */
 415                 if (!ret)
 416                         goto set_pwr_exit;
 417         }
 418
 419         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 420                 0, NULL, 0, NULL, 0);
 421
 422         if (ret)
 423                 dev_err(&client->dev, "failed to change power setting.\n");
 424
 425 set_pwr_exit:
 426
 427         /*
 428          * The HID over I2C specification states that if a DEVICE needs time
 429          * after the PWR_ON request, it should utilise CLOCK stretching.
 430          * However, it has been observered that the Windows driver provides a
 431          * 1ms sleep between the PWR_ON and RESET requests.
 432          * According to Goodix Windows even waits 60 ms after (other?)
 433          * PWR_ON requests. Testing has confirmed that several devices
 434          * will not work properly without a delay after a PWR_ON request.
 435          */
 436         if (!ret && power_state == I2C_HID_PWR_ON)
 437                 msleep(60);
 438
 439         return ret;
 440 }
 441
 442 static int i2c_hid_hwreset(struct i2c_client *client)
 443 {
 444         struct i2c_hid *ihid = i2c_get_clientdata(client);
 445         int ret;
 446
 447         i2c_hid_dbg(ihid, "%s\n", __func__);
 448
 449         /*
 450          * This prevents sending feature reports while the device is
 451          * being reset. Otherwise we may lose the reset complete
 452          * interrupt.
 453          */
 454         mutex_lock(&ihid->reset_lock);
 455
 456         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 457         if (ret)
 458                 goto out_unlock;
 459
 460         i2c_hid_dbg(ihid, "resetting...\n");
 461
 462         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 463         if (ret) {
 464                 dev_err(&client->dev, "failed to reset device.\n");
 465                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 466                 goto out_unlock;
 467         }
 468
 469         /* At least some SIS devices need this after reset */
 470         if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
 471                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 472
 473 out_unlock:
 474         mutex_unlock(&ihid->reset_lock);
 475         return ret;
 476 }
 477
 478 static void i2c_hid_get_input(struct i2c_hid *ihid)
 479 {
 480         int ret;
 481         u32 ret_size;
 482         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 483
 484         if (size > ihid->bufsize)
 485                 size = ihid->bufsize;
 486
 487         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 488         if (ret != size) {
 489                 if (ret < 0)
 490                         return;
 491
 492                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 493                         __func__, ret, size);
 494                 return;
 495         }
 496
 497         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 498
 499         if (!ret_size) {
 500                 /* host or device initiated RESET completed */
 501                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 502                         wake_up(&ihid->wait);
 503                 return;
 504         }
 505
 506         if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
 507                 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
 508                               "there's no data\n", __func__);
 509                 return;
 510         }
 511
 512         if ((ret_size > size) || (ret_size < 2)) {
 513                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 514                         ihid->inbuf[0] = size & 0xff;
 515                         ihid->inbuf[1] = size >> 8;
 516                         ret_size = size;
 517                 } else {
 518                         dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 519                                 __func__, size, ret_size);
 520                         return;
 521                 }
 522         }
 523
 524         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 525
 526         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 527                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 528                                 ret_size - 2, 1);
 529
 530         return;
 531 }
 532
 533 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 534 {
 535         struct i2c_hid *ihid = dev_id;
 536
 537         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 538                 return IRQ_HANDLED;
 539
 540         i2c_hid_get_input(ihid);
 541
 542         return IRQ_HANDLED;
 543 }
 544
 545 static int i2c_hid_get_report_length(struct hid_report *report)
 546 {
 547         return ((report->size - 1) >> 3) + 1 +
 548                 report->device->report_enum[report->type].numbered + 2;
 549 }
 550
 551 /*
 552  * Traverse the supplied list of reports and find the longest
 553  */
 554 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 555                 unsigned int *max)
 556 {
 557         struct hid_report *report;
 558         unsigned int size;
 559
 560         /* We should not rely on wMaxInputLength, as some devices may set it to
 561          * a wrong length. */
 562         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 563                 size = i2c_hid_get_report_length(report);
 564                 if (*max < size)
 565                         *max = size;
 566         }
 567 }
 568
 569 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 570 {
 571         kfree(ihid->inbuf);
 572         kfree(ihid->rawbuf);
 573         kfree(ihid->argsbuf);
 574         kfree(ihid->cmdbuf);
 575         ihid->inbuf = NULL;
 576         ihid->rawbuf = NULL;
 577         ihid->cmdbuf = NULL;
 578         ihid->argsbuf = NULL;
 579         ihid->bufsize = 0;
 580 }
 581
 582 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 583 {
 584         /* the worst case is computed from the set_report command with a
 585          * reportID > 15 and the maximum report length */
 586         int args_len = sizeof(__u8) + /* ReportID */
 587                        sizeof(__u8) + /* optional ReportID byte */
 588                        sizeof(__u16) + /* data register */
 589                        sizeof(__u16) + /* size of the report */
 590                        report_size; /* report */
 591
 592         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 593         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 594         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 595         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 596
 597         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 598                 i2c_hid_free_buffers(ihid);
 599                 return -ENOMEM;
 600         }
 601
 602         ihid->bufsize = report_size;
 603
 604         return 0;
 605 }
 606
 607 static int i2c_hid_get_raw_report(struct hid_device *hid,
 608                 unsigned char report_number, __u8 *buf, size_t count,
 609                 unsigned char report_type)
 610 {
 611         struct i2c_client *client = hid->driver_data;
 612         struct i2c_hid *ihid = i2c_get_clientdata(client);
 613         size_t ret_count, ask_count;
 614         int ret;
 615
 616         if (report_type == HID_OUTPUT_REPORT)
 617                 return -EINVAL;
 618
 619         /* +2 bytes to include the size of the reply in the query buffer */
 620         ask_count = min(count + 2, (size_t)ihid->bufsize);
 621
 622         ret = i2c_hid_get_report(client,
 623                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 624                         report_number, ihid->rawbuf, ask_count);
 625
 626         if (ret < 0)
 627                 return ret;
 628
 629         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 630
 631         if (ret_count <= 2)
 632                 return 0;
 633
 634         ret_count = min(ret_count, ask_count);
 635
 636         /* The query buffer contains the size, dropping it in the reply */
 637         count = min(count, ret_count - 2);
 638         memcpy(buf, ihid->rawbuf + 2, count);
 639
 640         return count;
 641 }
 642
 643 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 644                 size_t count, unsigned char report_type, bool use_data)
 645 {
 646         struct i2c_client *client = hid->driver_data;
 647         struct i2c_hid *ihid = i2c_get_clientdata(client);
 648         int report_id = buf[0];
 649         int ret;
 650
 651         if (report_type == HID_INPUT_REPORT)
 652                 return -EINVAL;
 653
 654         mutex_lock(&ihid->reset_lock);
 655
 656         if (report_id) {
 657                 buf++;
 658                 count--;
 659         }
 660
 661         ret = i2c_hid_set_or_send_report(client,
 662                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 663                                 report_id, buf, count, use_data);
 664
 665         if (report_id && ret >= 0)
 666                 ret++; /* add report_id to the number of transfered bytes */
 667
 668         mutex_unlock(&ihid->reset_lock);
 669
 670         return ret;
 671 }
 672
 673 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 674                 size_t count)
 675 {
 676         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 677                         false);
 678 }
 679
 680 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 681                                __u8 *buf, size_t len, unsigned char rtype,
 682                                int reqtype)
 683 {
 684         switch (reqtype) {
 685         case HID_REQ_GET_REPORT:
 686                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 687         case HID_REQ_SET_REPORT:
 688                 if (buf[0] != reportnum)
 689                         return -EINVAL;
 690                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 691         default:
 692                 return -EIO;
 693         }
 694 }
 695
 696 static int i2c_hid_parse(struct hid_device *hid)
 697 {
 698         struct i2c_client *client = hid->driver_data;
 699         struct i2c_hid *ihid = i2c_get_clientdata(client);
 700         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 701         unsigned int rsize;
 702         char *rdesc;
 703         int ret;
 704         int tries = 3;
 705         char *use_override;
 706
 707         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 708
 709         rsize = le16_to_cpu(hdesc->wReportDescLength);
 710         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 711                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 712                 return -EINVAL;
 713         }
 714
 715         do {
 716                 ret = i2c_hid_hwreset(client);
 717                 if (ret)
 718                         msleep(1000);
 719         } while (tries-- > 0 && ret);
 720
 721         if (ret)
 722                 return ret;
 723
 724         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 725                                                                 &rsize);
 726
 727         if (use_override) {
 728                 rdesc = use_override;
 729                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 730         } else {
 731                 rdesc = kzalloc(rsize, GFP_KERNEL);
 732
 733                 if (!rdesc) {
 734                         dbg_hid("couldn't allocate rdesc memory\n");
 735                         return -ENOMEM;
 736                 }
 737
 738                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 739
 740                 ret = i2c_hid_command(client, &hid_report_descr_cmd,
 741                                       rdesc, rsize);
 742                 if (ret) {
 743                         hid_err(hid, "reading report descriptor failed\n");
 744                         kfree(rdesc);
 745                         return -EIO;
 746                 }
 747         }
 748
 749         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 750
 751         ret = hid_parse_report(hid, rdesc, rsize);
 752         if (!use_override)
 753                 kfree(rdesc);
 754
 755         if (ret) {
 756                 dbg_hid("parsing report descriptor failed\n");
 757                 return ret;
 758         }
 759
 760         return 0;
 761 }
 762
 763 static int i2c_hid_start(struct hid_device *hid)
 764 {
 765         struct i2c_client *client = hid->driver_data;
 766         struct i2c_hid *ihid = i2c_get_clientdata(client);
 767         int ret;
 768         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 769
 770         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 771         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 772         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 773
 774         if (bufsize > ihid->bufsize) {
 775                 disable_irq(client->irq);
 776                 i2c_hid_free_buffers(ihid);
 777
 778                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 779                 enable_irq(client->irq);
 780
 781                 if (ret)
 782                         return ret;
 783         }
 784
 785         return 0;
 786 }
 787
 788 static void i2c_hid_stop(struct hid_device *hid)
 789 {
 790         hid->claimed = 0;
 791 }
 792
 793 static int i2c_hid_open(struct hid_device *hid)
 794 {
 795         struct i2c_client *client = hid->driver_data;
 796         struct i2c_hid *ihid = i2c_get_clientdata(client);
 797
 798         set_bit(I2C_HID_STARTED, &ihid->flags);
 799         return 0;
 800 }
 801
 802 static void i2c_hid_close(struct hid_device *hid)
 803 {
 804         struct i2c_client *client = hid->driver_data;
 805         struct i2c_hid *ihid = i2c_get_clientdata(client);
 806
 807         clear_bit(I2C_HID_STARTED, &ihid->flags);
 808 }
 809
 810 struct hid_ll_driver i2c_hid_ll_driver = {
 811         .parse = i2c_hid_parse,
 812         .start = i2c_hid_start,
 813         .stop = i2c_hid_stop,
 814         .open = i2c_hid_open,
 815         .close = i2c_hid_close,
 816         .output_report = i2c_hid_output_report,
 817         .raw_request = i2c_hid_raw_request,
 818 };
 819 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 820
 821 static int i2c_hid_init_irq(struct i2c_client *client)
 822 {
 823         struct i2c_hid *ihid = i2c_get_clientdata(client);
 824         unsigned long irqflags = 0;
 825         int ret;
 826
 827         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 828
 829         if (!irq_get_trigger_type(client->irq))
 830                 irqflags = IRQF_TRIGGER_LOW;
 831
 832         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 833                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 834         if (ret < 0) {
 835                 dev_warn(&client->dev,
 836                         "Could not register for %s interrupt, irq = %d,"
 837                         " ret = %d\n",
 838                         client->name, client->irq, ret);
 839
 840                 return ret;
 841         }
 842
 843         return 0;
 844 }
 845
 846 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 847 {
 848         struct i2c_client *client = ihid->client;
 849         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 850         unsigned int dsize;
 851         int ret;
 852
 853         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 854         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 855                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 856                 ihid->hdesc =
 857                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 858         } else {
 859                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 860                 ret = i2c_hid_command(client, &hid_descr_cmd,
 861                                       ihid->hdesc_buffer,
 862                                       sizeof(struct i2c_hid_desc));
 863                 if (ret) {
 864                         dev_err(&client->dev, "hid_descr_cmd failed\n");
 865                         return -ENODEV;
 866                 }
 867         }
 868
 869         /* Validate the length of HID descriptor, the 4 first bytes:
 870          * bytes 0-1 -> length
 871          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 872         /* check bcdVersion == 1.0 */
 873         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 874                 dev_err(&client->dev,
 875                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 876                         le16_to_cpu(hdesc->bcdVersion));
 877                 return -ENODEV;
 878         }
 879
 880         /* Descriptor length should be 30 bytes as per the specification */
 881         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 882         if (dsize != sizeof(struct i2c_hid_desc)) {
 883                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 884                         dsize);
 885                 return -ENODEV;
 886         }
 887         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 888         return 0;
 889 }
 890
 891 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 892 {
 893         if (!ihid->ops->power_up)
 894                 return 0;
 895
 896         return ihid->ops->power_up(ihid->ops);
 897 }
 898
 899 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 900 {
 901         if (!ihid->ops->power_down)
 902                 return;
 903
 904         ihid->ops->power_down(ihid->ops);
 905 }
 906
 907 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 908 {
 909         if (!ihid->ops->shutdown_tail)
 910                 return;
 911
 912         ihid->ops->shutdown_tail(ihid->ops);
 913 }
 914
 915 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 916                        u16 hid_descriptor_address)
 917 {
 918         int ret;
 919         struct i2c_hid *ihid;
 920         struct hid_device *hid;
 921
 922         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 923
 924         if (!client->irq) {
 925                 dev_err(&client->dev,
 926                         "HID over i2c has not been provided an Int IRQ\n");
 927                 return -EINVAL;
 928         }
 929
 930         if (client->irq < 0) {
 931                 if (client->irq != -EPROBE_DEFER)
 932                         dev_err(&client->dev,
 933                                 "HID over i2c doesn't have a valid IRQ\n");
 934                 return client->irq;
 935         }
 936
 937         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 938         if (!ihid)
 939                 return -ENOMEM;
 940
 941         ihid->ops = ops;
 942
 943         ret = i2c_hid_core_power_up(ihid);
 944         if (ret)
 945                 return ret;
 946
 947         i2c_set_clientdata(client, ihid);
 948
 949         ihid->client = client;
 950
 951         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 952
 953         init_waitqueue_head(&ihid->wait);
 954         mutex_init(&ihid->reset_lock);
 955
 956         /* we need to allocate the command buffer without knowing the maximum
 957          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 958          * real computation later. */
 959         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 960         if (ret < 0)
 961                 goto err_powered;
 962
 963         device_enable_async_suspend(&client->dev);
 964
 965         /* Make sure there is something at this address */
 966         ret = i2c_smbus_read_byte(client);
 967         if (ret < 0) {
 968                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
 969                 ret = -ENXIO;
 970                 goto err_powered;
 971         }
 972
 973         ret = i2c_hid_fetch_hid_descriptor(ihid);
 974         if (ret < 0) {
 975                 dev_err(&client->dev,
 976                         "Failed to fetch the HID Descriptor\n");
 977                 goto err_powered;
 978         }
 979
 980         ret = i2c_hid_init_irq(client);
 981         if (ret < 0)
 982                 goto err_powered;
 983
 984         hid = hid_allocate_device();
 985         if (IS_ERR(hid)) {
 986                 ret = PTR_ERR(hid);
 987                 goto err_irq;
 988         }
 989
 990         ihid->hid = hid;
 991
 992         hid->driver_data = client;
 993         hid->ll_driver = &i2c_hid_ll_driver;
 994         hid->dev.parent = &client->dev;
 995         hid->bus = BUS_I2C;
 996         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 997         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 998         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
 999
1000         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1001                  client->name, (u16)hid->vendor, (u16)hid->product);
1002         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1003
1004         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1005
1006         ret = hid_add_device(hid);
1007         if (ret) {
1008                 if (ret != -ENODEV)
1009                         hid_err(client, "can't add hid device: %d\n", ret);
1010                 goto err_mem_free;
1011         }
1012
1013         return 0;
1014
1015 err_mem_free:
1016         hid_destroy_device(hid);
1017
1018 err_irq:
1019         free_irq(client->irq, ihid);
1020
1021 err_powered:
1022         i2c_hid_core_power_down(ihid);
1023         i2c_hid_free_buffers(ihid);
1024         return ret;
1025 }
1026 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1027
1028 int i2c_hid_core_remove(struct i2c_client *client)
1029 {
1030         struct i2c_hid *ihid = i2c_get_clientdata(client);
1031         struct hid_device *hid;
1032
1033         hid = ihid->hid;
1034         hid_destroy_device(hid);
1035
1036         free_irq(client->irq, ihid);
1037
1038         if (ihid->bufsize)
1039                 i2c_hid_free_buffers(ihid);
1040
1041         i2c_hid_core_power_down(ihid);
1042
1043         return 0;
1044 }
1045 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1046
1047 void i2c_hid_core_shutdown(struct i2c_client *client)
1048 {
1049         struct i2c_hid *ihid = i2c_get_clientdata(client);
1050
1051         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1052         free_irq(client->irq, ihid);
1053
1054         i2c_hid_core_shutdown_tail(ihid);
1055 }
1056 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1057
1058 #ifdef CONFIG_PM_SLEEP
1059 static int i2c_hid_core_suspend(struct device *dev)
1060 {
1061         struct i2c_client *client = to_i2c_client(dev);
1062         struct i2c_hid *ihid = i2c_get_clientdata(client);
1063         struct hid_device *hid = ihid->hid;
1064         int ret;
1065         int wake_status;
1066
1067         if (hid->driver && hid->driver->suspend) {
1068                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1069                 if (ret < 0)
1070                         return ret;
1071         }
1072
1073         /* Save some power */
1074         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1075
1076         disable_irq(client->irq);
1077
1078         if (device_may_wakeup(&client->dev)) {
1079                 wake_status = enable_irq_wake(client->irq);
1080                 if (!wake_status)
1081                         ihid->irq_wake_enabled = true;
1082                 else
1083                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1084                                 wake_status);
1085         } else {
1086                 i2c_hid_core_power_down(ihid);
1087         }
1088
1089         return 0;
1090 }
1091
1092 static int i2c_hid_core_resume(struct device *dev)
1093 {
1094         int ret;
1095         struct i2c_client *client = to_i2c_client(dev);
1096         struct i2c_hid *ihid = i2c_get_clientdata(client);
1097         struct hid_device *hid = ihid->hid;
1098         int wake_status;
1099
1100         if (!device_may_wakeup(&client->dev)) {
1101                 i2c_hid_core_power_up(ihid);
1102         } else if (ihid->irq_wake_enabled) {
1103                 wake_status = disable_irq_wake(client->irq);
1104                 if (!wake_status)
1105                         ihid->irq_wake_enabled = false;
1106                 else
1107                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1108                                 wake_status);
1109         }
1110
1111         enable_irq(client->irq);
1112
1113         /* Instead of resetting device, simply powers the device on. This
1114          * solves "incomplete reports" on Raydium devices 2386:3118 and
1115          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1116          * data after a suspend/resume.
1117          *
1118          * However some ALPS touchpads generate IRQ storm without reset, so
1119          * let's still reset them here.
1120          */
1121         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1122                 ret = i2c_hid_hwreset(client);
1123         else
1124                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
1125
1126         if (ret)
1127                 return ret;
1128
1129         if (hid->driver && hid->driver->reset_resume) {
1130                 ret = hid->driver->reset_resume(hid);
1131                 return ret;
1132         }
1133
1134         return 0;
1135 }
1136 #endif
1137
1138 const struct dev_pm_ops i2c_hid_core_pm = {
1139         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1140 };
1141 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1142
1143 MODULE_DESCRIPTION("HID over I2C core driver");
1144 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1145 MODULE_LICENSE("GPL");