drivers/hid/i2c-hid/i2c-hid-core.c

   1 /*
   2  * HID over I2C protocol implementation
   3  *
   4  * Copyright (c) 2012 Benjamin Tissoires <[email protected]>
   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 <[email protected]>
  12  *  Copyright (c) 2005 Michael Haboustak <[email protected]> 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
  49
  50 /* flags */
  51 #define I2C_HID_STARTED         0
  52 #define I2C_HID_RESET_PENDING   1
  53 #define I2C_HID_READ_PENDING    2
  54
  55 #define I2C_HID_PWR_ON          0x00
  56 #define I2C_HID_PWR_SLEEP       0x01
  57
  58 /* debug option */
  59 static bool debug;
  60 module_param(debug, bool, 0444);
  61 MODULE_PARM_DESC(debug, "print a lot of debug information");
  62
  63 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  64 do {                                                                      \
  65         if (debug)                                                        \
  66                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  67 } while (0)
  68
  69 struct i2c_hid_desc {
  70         __le16 wHIDDescLength;
  71         __le16 bcdVersion;
  72         __le16 wReportDescLength;
  73         __le16 wReportDescRegister;
  74         __le16 wInputRegister;
  75         __le16 wMaxInputLength;
  76         __le16 wOutputRegister;
  77         __le16 wMaxOutputLength;
  78         __le16 wCommandRegister;
  79         __le16 wDataRegister;
  80         __le16 wVendorID;
  81         __le16 wProductID;
  82         __le16 wVersionID;
  83         __le32 reserved;
  84 } __packed;
  85
  86 struct i2c_hid_cmd {
  87         unsigned int registerIndex;
  88         __u8 opcode;
  89         unsigned int length;
  90         bool wait;
  91 };
  92
  93 union command {
  94         u8 data[0];
  95         struct cmd {
  96                 __le16 reg;
  97                 __u8 reportTypeID;
  98                 __u8 opcode;
  99         } __packed c;
 100 };
 101
 102 #define I2C_HID_CMD(opcode_) \
 103         .opcode = opcode_, .length = 4, \
 104         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 105
 106 /* fetch HID descriptor */
 107 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 108 /* fetch report descriptors */
 109 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 110                 .registerIndex = offsetof(struct i2c_hid_desc,
 111                         wReportDescRegister),
 112                 .opcode = 0x00,
 113                 .length = 2 };
 114 /* commands */
 115 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 116                                                           .wait = true };
 117 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 118 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 119 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 120 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 121
 122 /*
 123  * These definitions are not used here, but are defined by the spec.
 124  * Keeping them here for documentation purposes.
 125  *
 126  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 127  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 128  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 129  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 130  */
 131
 132 /* 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_ELAN, HID_ANY_ID,
 174                  I2C_HID_QUIRK_BOGUS_IRQ },
 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         { 0, 0 }
 182 };
 183
 184 /*
 185  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 186  * @idVendor: the 16-bit vendor ID
 187  * @idProduct: the 16-bit product ID
 188  *
 189  * Returns: a u32 quirks value.
 190  */
 191 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 192 {
 193         u32 quirks = 0;
 194         int n;
 195
 196         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 197                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 198                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 199                      i2c_hid_quirks[n].idProduct == idProduct))
 200                         quirks = i2c_hid_quirks[n].quirks;
 201
 202         return quirks;
 203 }
 204
 205 static int __i2c_hid_command(struct i2c_client *client,
 206                 const struct i2c_hid_cmd *command, u8 reportID,
 207                 u8 reportType, u8 *args, int args_len,
 208                 unsigned char *buf_recv, int data_len)
 209 {
 210         struct i2c_hid *ihid = i2c_get_clientdata(client);
 211         union command *cmd = (union command *)ihid->cmdbuf;
 212         int ret;
 213         struct i2c_msg msg[2];
 214         int msg_num = 1;
 215
 216         int length = command->length;
 217         bool wait = command->wait;
 218         unsigned int registerIndex = command->registerIndex;
 219
 220         /* special case for hid_descr_cmd */
 221         if (command == &hid_descr_cmd) {
 222                 cmd->c.reg = ihid->wHIDDescRegister;
 223         } else {
 224                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 225                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 226         }
 227
 228         if (length > 2) {
 229                 cmd->c.opcode = command->opcode;
 230                 cmd->c.reportTypeID = reportID | reportType << 4;
 231         }
 232
 233         memcpy(cmd->data + length, args, args_len);
 234         length += args_len;
 235
 236         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 237
 238         msg[0].addr = client->addr;
 239         msg[0].flags = client->flags & I2C_M_TEN;
 240         msg[0].len = length;
 241         msg[0].buf = cmd->data;
 242         if (data_len > 0) {
 243                 msg[1].addr = client->addr;
 244                 msg[1].flags = client->flags & I2C_M_TEN;
 245                 msg[1].flags |= I2C_M_RD;
 246                 msg[1].len = data_len;
 247                 msg[1].buf = buf_recv;
 248                 msg_num = 2;
 249                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 250         }
 251
 252         if (wait)
 253                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 254
 255         ret = i2c_transfer(client->adapter, msg, msg_num);
 256
 257         if (data_len > 0)
 258                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 259
 260         if (ret != msg_num)
 261                 return ret < 0 ? ret : -EIO;
 262
 263         ret = 0;
 264
 265         if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
 266                 msleep(100);
 267         } else if (wait) {
 268                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 269                 if (!wait_event_timeout(ihid->wait,
 270                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 271                                 msecs_to_jiffies(5000)))
 272                         ret = -ENODATA;
 273                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 274         }
 275
 276         return ret;
 277 }
 278
 279 static int i2c_hid_command(struct i2c_client *client,
 280                 const struct i2c_hid_cmd *command,
 281                 unsigned char *buf_recv, int data_len)
 282 {
 283         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 284                                 buf_recv, data_len);
 285 }
 286
 287 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 288                 u8 reportID, unsigned char *buf_recv, int data_len)
 289 {
 290         struct i2c_hid *ihid = i2c_get_clientdata(client);
 291         u8 args[3];
 292         int ret;
 293         int args_len = 0;
 294         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 295
 296         i2c_hid_dbg(ihid, "%s\n", __func__);
 297
 298         if (reportID >= 0x0F) {
 299                 args[args_len++] = reportID;
 300                 reportID = 0x0F;
 301         }
 302
 303         args[args_len++] = readRegister & 0xFF;
 304         args[args_len++] = readRegister >> 8;
 305
 306         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 307                 reportType, args, args_len, buf_recv, data_len);
 308         if (ret) {
 309                 dev_err(&client->dev,
 310                         "failed to retrieve report from device.\n");
 311                 return ret;
 312         }
 313
 314         return 0;
 315 }
 316
 317 /**
 318  * i2c_hid_set_or_send_report: forward an incoming report to the device
 319  * @client: the i2c_client of the device
 320  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 321  * @reportID: the report ID
 322  * @buf: the actual data to transfer, without the report ID
 323  * @data_len: size of buf
 324  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 325  */
 326 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 327                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 328 {
 329         struct i2c_hid *ihid = i2c_get_clientdata(client);
 330         u8 *args = ihid->argsbuf;
 331         const struct i2c_hid_cmd *hidcmd;
 332         int ret;
 333         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 334         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 335         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 336         u16 size;
 337         int args_len;
 338         int index = 0;
 339
 340         i2c_hid_dbg(ihid, "%s\n", __func__);
 341
 342         if (data_len > ihid->bufsize)
 343                 return -EINVAL;
 344
 345         size =          2                       /* size */ +
 346                         (reportID ? 1 : 0)      /* reportID */ +
 347                         data_len                /* buf */;
 348         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 349                         2                       /* dataRegister */ +
 350                         size                    /* args */;
 351
 352         if (!use_data && maxOutputLength == 0)
 353                 return -ENOSYS;
 354
 355         if (reportID >= 0x0F) {
 356                 args[index++] = reportID;
 357                 reportID = 0x0F;
 358         }
 359
 360         /*
 361          * use the data register for feature reports or if the device does not
 362          * support the output register
 363          */
 364         if (use_data) {
 365                 args[index++] = dataRegister & 0xFF;
 366                 args[index++] = dataRegister >> 8;
 367                 hidcmd = &hid_set_report_cmd;
 368         } else {
 369                 args[index++] = outputRegister & 0xFF;
 370                 args[index++] = outputRegister >> 8;
 371                 hidcmd = &hid_no_cmd;
 372         }
 373
 374         args[index++] = size & 0xFF;
 375         args[index++] = size >> 8;
 376
 377         if (reportID)
 378                 args[index++] = reportID;
 379
 380         memcpy(&args[index], buf, data_len);
 381
 382         ret = __i2c_hid_command(client, hidcmd, reportID,
 383                 reportType, args, args_len, NULL, 0);
 384         if (ret) {
 385                 dev_err(&client->dev, "failed to set a report to device.\n");
 386                 return ret;
 387         }
 388
 389         return data_len;
 390 }
 391
 392 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 393 {
 394         struct i2c_hid *ihid = i2c_get_clientdata(client);
 395         int ret;
 396
 397         i2c_hid_dbg(ihid, "%s\n", __func__);
 398
 399         /*
 400          * Some devices require to send a command to wakeup before power on.
 401          * The call will get a return value (EREMOTEIO) but device will be
 402          * triggered and activated. After that, it goes like a normal device.
 403          */
 404         if (power_state == I2C_HID_PWR_ON &&
 405             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 406                 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
 407
 408                 /* Device was already activated */
 409                 if (!ret)
 410                         goto set_pwr_exit;
 411         }
 412
 413         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 414                 0, NULL, 0, NULL, 0);
 415
 416         if (ret)
 417                 dev_err(&client->dev, "failed to change power setting.\n");
 418
 419 set_pwr_exit:
 420
 421         /*
 422          * The HID over I2C specification states that if a DEVICE needs time
 423          * after the PWR_ON request, it should utilise CLOCK stretching.
 424          * However, it has been observered that the Windows driver provides a
 425          * 1ms sleep between the PWR_ON and RESET requests.
 426          * According to Goodix Windows even waits 60 ms after (other?)
 427          * PWR_ON requests. Testing has confirmed that several devices
 428          * will not work properly without a delay after a PWR_ON request.
 429          */
 430         if (!ret && power_state == I2C_HID_PWR_ON)
 431                 msleep(60);
 432
 433         return ret;
 434 }
 435
 436 static int i2c_hid_hwreset(struct i2c_client *client)
 437 {
 438         struct i2c_hid *ihid = i2c_get_clientdata(client);
 439         int ret;
 440
 441         i2c_hid_dbg(ihid, "%s\n", __func__);
 442
 443         /*
 444          * This prevents sending feature reports while the device is
 445          * being reset. Otherwise we may lose the reset complete
 446          * interrupt.
 447          */
 448         mutex_lock(&ihid->reset_lock);
 449
 450         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 451         if (ret)
 452                 goto out_unlock;
 453
 454         i2c_hid_dbg(ihid, "resetting...\n");
 455
 456         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 457         if (ret) {
 458                 dev_err(&client->dev, "failed to reset device.\n");
 459                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 460                 goto out_unlock;
 461         }
 462
 463         /* At least some SIS devices need this after reset */
 464         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 465
 466 out_unlock:
 467         mutex_unlock(&ihid->reset_lock);
 468         return ret;
 469 }
 470
 471 static void i2c_hid_get_input(struct i2c_hid *ihid)
 472 {
 473         int ret;
 474         u32 ret_size;
 475         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 476
 477         if (size > ihid->bufsize)
 478                 size = ihid->bufsize;
 479
 480         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 481         if (ret != size) {
 482                 if (ret < 0)
 483                         return;
 484
 485                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 486                         __func__, ret, size);
 487                 return;
 488         }
 489
 490         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 491
 492         if (!ret_size) {
 493                 /* host or device initiated RESET completed */
 494                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 495                         wake_up(&ihid->wait);
 496                 return;
 497         }
 498
 499         if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
 500                 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
 501                               "there's no data\n", __func__);
 502                 return;
 503         }
 504
 505         if ((ret_size > size) || (ret_size < 2)) {
 506                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 507                         ihid->inbuf[0] = size & 0xff;
 508                         ihid->inbuf[1] = size >> 8;
 509                         ret_size = size;
 510                 } else {
 511                         dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 512                                 __func__, size, ret_size);
 513                         return;
 514                 }
 515         }
 516
 517         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 518
 519         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 520                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 521                                 ret_size - 2, 1);
 522
 523         return;
 524 }
 525
 526 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 527 {
 528         struct i2c_hid *ihid = dev_id;
 529
 530         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 531                 return IRQ_HANDLED;
 532
 533         i2c_hid_get_input(ihid);
 534
 535         return IRQ_HANDLED;
 536 }
 537
 538 static int i2c_hid_get_report_length(struct hid_report *report)
 539 {
 540         return ((report->size - 1) >> 3) + 1 +
 541                 report->device->report_enum[report->type].numbered + 2;
 542 }
 543
 544 /*
 545  * Traverse the supplied list of reports and find the longest
 546  */
 547 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 548                 unsigned int *max)
 549 {
 550         struct hid_report *report;
 551         unsigned int size;
 552
 553         /* We should not rely on wMaxInputLength, as some devices may set it to
 554          * a wrong length. */
 555         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 556                 size = i2c_hid_get_report_length(report);
 557                 if (*max < size)
 558                         *max = size;
 559         }
 560 }
 561
 562 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 563 {
 564         kfree(ihid->inbuf);
 565         kfree(ihid->rawbuf);
 566         kfree(ihid->argsbuf);
 567         kfree(ihid->cmdbuf);
 568         ihid->inbuf = NULL;
 569         ihid->rawbuf = NULL;
 570         ihid->cmdbuf = NULL;
 571         ihid->argsbuf = NULL;
 572         ihid->bufsize = 0;
 573 }
 574
 575 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 576 {
 577         /* the worst case is computed from the set_report command with a
 578          * reportID > 15 and the maximum report length */
 579         int args_len = sizeof(__u8) + /* ReportID */
 580                        sizeof(__u8) + /* optional ReportID byte */
 581                        sizeof(__u16) + /* data register */
 582                        sizeof(__u16) + /* size of the report */
 583                        report_size; /* report */
 584
 585         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 586         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 587         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 588         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 589
 590         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 591                 i2c_hid_free_buffers(ihid);
 592                 return -ENOMEM;
 593         }
 594
 595         ihid->bufsize = report_size;
 596
 597         return 0;
 598 }
 599
 600 static int i2c_hid_get_raw_report(struct hid_device *hid,
 601                 unsigned char report_number, __u8 *buf, size_t count,
 602                 unsigned char report_type)
 603 {
 604         struct i2c_client *client = hid->driver_data;
 605         struct i2c_hid *ihid = i2c_get_clientdata(client);
 606         size_t ret_count, ask_count;
 607         int ret;
 608
 609         if (report_type == HID_OUTPUT_REPORT)
 610                 return -EINVAL;
 611
 612         /* +2 bytes to include the size of the reply in the query buffer */
 613         ask_count = min(count + 2, (size_t)ihid->bufsize);
 614
 615         ret = i2c_hid_get_report(client,
 616                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 617                         report_number, ihid->rawbuf, ask_count);
 618
 619         if (ret < 0)
 620                 return ret;
 621
 622         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 623
 624         if (ret_count <= 2)
 625                 return 0;
 626
 627         ret_count = min(ret_count, ask_count);
 628
 629         /* The query buffer contains the size, dropping it in the reply */
 630         count = min(count, ret_count - 2);
 631         memcpy(buf, ihid->rawbuf + 2, count);
 632
 633         return count;
 634 }
 635
 636 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 637                 size_t count, unsigned char report_type, bool use_data)
 638 {
 639         struct i2c_client *client = hid->driver_data;
 640         struct i2c_hid *ihid = i2c_get_clientdata(client);
 641         int report_id = buf[0];
 642         int ret;
 643
 644         if (report_type == HID_INPUT_REPORT)
 645                 return -EINVAL;
 646
 647         mutex_lock(&ihid->reset_lock);
 648
 649         if (report_id) {
 650                 buf++;
 651                 count--;
 652         }
 653
 654         ret = i2c_hid_set_or_send_report(client,
 655                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 656                                 report_id, buf, count, use_data);
 657
 658         if (report_id && ret >= 0)
 659                 ret++; /* add report_id to the number of transfered bytes */
 660
 661         mutex_unlock(&ihid->reset_lock);
 662
 663         return ret;
 664 }
 665
 666 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 667                 size_t count)
 668 {
 669         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 670                         false);
 671 }
 672
 673 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 674                                __u8 *buf, size_t len, unsigned char rtype,
 675                                int reqtype)
 676 {
 677         switch (reqtype) {
 678         case HID_REQ_GET_REPORT:
 679                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 680         case HID_REQ_SET_REPORT:
 681                 if (buf[0] != reportnum)
 682                         return -EINVAL;
 683                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 684         default:
 685                 return -EIO;
 686         }
 687 }
 688
 689 static int i2c_hid_parse(struct hid_device *hid)
 690 {
 691         struct i2c_client *client = hid->driver_data;
 692         struct i2c_hid *ihid = i2c_get_clientdata(client);
 693         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 694         unsigned int rsize;
 695         char *rdesc;
 696         int ret;
 697         int tries = 3;
 698         char *use_override;
 699
 700         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 701
 702         rsize = le16_to_cpu(hdesc->wReportDescLength);
 703         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 704                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 705                 return -EINVAL;
 706         }
 707
 708         do {
 709                 ret = i2c_hid_hwreset(client);
 710                 if (ret)
 711                         msleep(1000);
 712         } while (tries-- > 0 && ret);
 713
 714         if (ret)
 715                 return ret;
 716
 717         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 718                                                                 &rsize);
 719
 720         if (use_override) {
 721                 rdesc = use_override;
 722                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 723         } else {
 724                 rdesc = kzalloc(rsize, GFP_KERNEL);
 725
 726                 if (!rdesc) {
 727                         dbg_hid("couldn't allocate rdesc memory\n");
 728                         return -ENOMEM;
 729                 }
 730
 731                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 732
 733                 ret = i2c_hid_command(client, &hid_report_descr_cmd,
 734                                       rdesc, rsize);
 735                 if (ret) {
 736                         hid_err(hid, "reading report descriptor failed\n");
 737                         kfree(rdesc);
 738                         return -EIO;
 739                 }
 740         }
 741
 742         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 743
 744         ret = hid_parse_report(hid, rdesc, rsize);
 745         if (!use_override)
 746                 kfree(rdesc);
 747
 748         if (ret) {
 749                 dbg_hid("parsing report descriptor failed\n");
 750                 return ret;
 751         }
 752
 753         return 0;
 754 }
 755
 756 static int i2c_hid_start(struct hid_device *hid)
 757 {
 758         struct i2c_client *client = hid->driver_data;
 759         struct i2c_hid *ihid = i2c_get_clientdata(client);
 760         int ret;
 761         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 762
 763         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 764         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 765         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 766
 767         if (bufsize > ihid->bufsize) {
 768                 disable_irq(client->irq);
 769                 i2c_hid_free_buffers(ihid);
 770
 771                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 772                 enable_irq(client->irq);
 773
 774                 if (ret)
 775                         return ret;
 776         }
 777
 778         return 0;
 779 }
 780
 781 static void i2c_hid_stop(struct hid_device *hid)
 782 {
 783         hid->claimed = 0;
 784 }
 785
 786 static int i2c_hid_open(struct hid_device *hid)
 787 {
 788         struct i2c_client *client = hid->driver_data;
 789         struct i2c_hid *ihid = i2c_get_clientdata(client);
 790
 791         set_bit(I2C_HID_STARTED, &ihid->flags);
 792         return 0;
 793 }
 794
 795 static void i2c_hid_close(struct hid_device *hid)
 796 {
 797         struct i2c_client *client = hid->driver_data;
 798         struct i2c_hid *ihid = i2c_get_clientdata(client);
 799
 800         clear_bit(I2C_HID_STARTED, &ihid->flags);
 801 }
 802
 803 struct hid_ll_driver i2c_hid_ll_driver = {
 804         .parse = i2c_hid_parse,
 805         .start = i2c_hid_start,
 806         .stop = i2c_hid_stop,
 807         .open = i2c_hid_open,
 808         .close = i2c_hid_close,
 809         .output_report = i2c_hid_output_report,
 810         .raw_request = i2c_hid_raw_request,
 811 };
 812 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 813
 814 static int i2c_hid_init_irq(struct i2c_client *client)
 815 {
 816         struct i2c_hid *ihid = i2c_get_clientdata(client);
 817         unsigned long irqflags = 0;
 818         int ret;
 819
 820         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 821
 822         if (!irq_get_trigger_type(client->irq))
 823                 irqflags = IRQF_TRIGGER_LOW;
 824
 825         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 826                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 827         if (ret < 0) {
 828                 dev_warn(&client->dev,
 829                         "Could not register for %s interrupt, irq = %d,"
 830                         " ret = %d\n",
 831                         client->name, client->irq, ret);
 832
 833                 return ret;
 834         }
 835
 836         return 0;
 837 }
 838
 839 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 840 {
 841         struct i2c_client *client = ihid->client;
 842         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 843         unsigned int dsize;
 844         int ret;
 845
 846         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 847         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 848                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 849                 ihid->hdesc =
 850                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 851         } else {
 852                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 853                 ret = i2c_hid_command(client, &hid_descr_cmd,
 854                                       ihid->hdesc_buffer,
 855                                       sizeof(struct i2c_hid_desc));
 856                 if (ret) {
 857                         dev_err(&client->dev, "hid_descr_cmd failed\n");
 858                         return -ENODEV;
 859                 }
 860         }
 861
 862         /* Validate the length of HID descriptor, the 4 first bytes:
 863          * bytes 0-1 -> length
 864          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 865         /* check bcdVersion == 1.0 */
 866         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 867                 dev_err(&client->dev,
 868                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 869                         le16_to_cpu(hdesc->bcdVersion));
 870                 return -ENODEV;
 871         }
 872
 873         /* Descriptor length should be 30 bytes as per the specification */
 874         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 875         if (dsize != sizeof(struct i2c_hid_desc)) {
 876                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 877                         dsize);
 878                 return -ENODEV;
 879         }
 880         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 881         return 0;
 882 }
 883
 884 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 885 {
 886         if (!ihid->ops->power_up)
 887                 return 0;
 888
 889         return ihid->ops->power_up(ihid->ops);
 890 }
 891
 892 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 893 {
 894         if (!ihid->ops->power_down)
 895                 return;
 896
 897         ihid->ops->power_down(ihid->ops);
 898 }
 899
 900 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 901 {
 902         if (!ihid->ops->shutdown_tail)
 903                 return;
 904
 905         ihid->ops->shutdown_tail(ihid->ops);
 906 }
 907
 908 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 909                        u16 hid_descriptor_address)
 910 {
 911         int ret;
 912         struct i2c_hid *ihid;
 913         struct hid_device *hid;
 914
 915         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 916
 917         if (!client->irq) {
 918                 dev_err(&client->dev,
 919                         "HID over i2c has not been provided an Int IRQ\n");
 920                 return -EINVAL;
 921         }
 922
 923         if (client->irq < 0) {
 924                 if (client->irq != -EPROBE_DEFER)
 925                         dev_err(&client->dev,
 926                                 "HID over i2c doesn't have a valid IRQ\n");
 927                 return client->irq;
 928         }
 929
 930         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 931         if (!ihid)
 932                 return -ENOMEM;
 933
 934         ihid->ops = ops;
 935
 936         ret = i2c_hid_core_power_up(ihid);
 937         if (ret)
 938                 return ret;
 939
 940         i2c_set_clientdata(client, ihid);
 941
 942         ihid->client = client;
 943
 944         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 945
 946         init_waitqueue_head(&ihid->wait);
 947         mutex_init(&ihid->reset_lock);
 948
 949         /* we need to allocate the command buffer without knowing the maximum
 950          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 951          * real computation later. */
 952         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 953         if (ret < 0)
 954                 goto err_powered;
 955
 956         device_enable_async_suspend(&client->dev);
 957
 958         /* Make sure there is something at this address */
 959         ret = i2c_smbus_read_byte(client);
 960         if (ret < 0) {
 961                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
 962                 ret = -ENXIO;
 963                 goto err_powered;
 964         }
 965
 966         ret = i2c_hid_fetch_hid_descriptor(ihid);
 967         if (ret < 0) {
 968                 dev_err(&client->dev,
 969                         "Failed to fetch the HID Descriptor\n");
 970                 goto err_powered;
 971         }
 972
 973         ret = i2c_hid_init_irq(client);
 974         if (ret < 0)
 975                 goto err_powered;
 976
 977         hid = hid_allocate_device();
 978         if (IS_ERR(hid)) {
 979                 ret = PTR_ERR(hid);
 980                 goto err_irq;
 981         }
 982
 983         ihid->hid = hid;
 984
 985         hid->driver_data = client;
 986         hid->ll_driver = &i2c_hid_ll_driver;
 987         hid->dev.parent = &client->dev;
 988         hid->bus = BUS_I2C;
 989         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 990         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 991         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
 992
 993         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
 994                  client->name, hid->vendor, hid->product);
 995         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
 996
 997         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
 998
 999         ret = hid_add_device(hid);
1000         if (ret) {
1001                 if (ret != -ENODEV)
1002                         hid_err(client, "can't add hid device: %d\n", ret);
1003                 goto err_mem_free;
1004         }
1005
1006         return 0;
1007
1008 err_mem_free:
1009         hid_destroy_device(hid);
1010
1011 err_irq:
1012         free_irq(client->irq, ihid);
1013
1014 err_powered:
1015         i2c_hid_core_power_down(ihid);
1016         i2c_hid_free_buffers(ihid);
1017         return ret;
1018 }
1019 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1020
1021 int i2c_hid_core_remove(struct i2c_client *client)
1022 {
1023         struct i2c_hid *ihid = i2c_get_clientdata(client);
1024         struct hid_device *hid;
1025
1026         hid = ihid->hid;
1027         hid_destroy_device(hid);
1028
1029         free_irq(client->irq, ihid);
1030
1031         if (ihid->bufsize)
1032                 i2c_hid_free_buffers(ihid);
1033
1034         i2c_hid_core_power_down(ihid);
1035
1036         return 0;
1037 }
1038 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1039
1040 void i2c_hid_core_shutdown(struct i2c_client *client)
1041 {
1042         struct i2c_hid *ihid = i2c_get_clientdata(client);
1043
1044         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1045         free_irq(client->irq, ihid);
1046
1047         i2c_hid_core_shutdown_tail(ihid);
1048 }
1049 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1050
1051 #ifdef CONFIG_PM_SLEEP
1052 static int i2c_hid_core_suspend(struct device *dev)
1053 {
1054         struct i2c_client *client = to_i2c_client(dev);
1055         struct i2c_hid *ihid = i2c_get_clientdata(client);
1056         struct hid_device *hid = ihid->hid;
1057         int ret;
1058         int wake_status;
1059
1060         if (hid->driver && hid->driver->suspend) {
1061                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1062                 if (ret < 0)
1063                         return ret;
1064         }
1065
1066         /* Save some power */
1067         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1068
1069         disable_irq(client->irq);
1070
1071         if (device_may_wakeup(&client->dev)) {
1072                 wake_status = enable_irq_wake(client->irq);
1073                 if (!wake_status)
1074                         ihid->irq_wake_enabled = true;
1075                 else
1076                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1077                                 wake_status);
1078         } else {
1079                 i2c_hid_core_power_down(ihid);
1080         }
1081
1082         return 0;
1083 }
1084
1085 static int i2c_hid_core_resume(struct device *dev)
1086 {
1087         int ret;
1088         struct i2c_client *client = to_i2c_client(dev);
1089         struct i2c_hid *ihid = i2c_get_clientdata(client);
1090         struct hid_device *hid = ihid->hid;
1091         int wake_status;
1092
1093         if (!device_may_wakeup(&client->dev)) {
1094                 i2c_hid_core_power_up(ihid);
1095         } else if (ihid->irq_wake_enabled) {
1096                 wake_status = disable_irq_wake(client->irq);
1097                 if (!wake_status)
1098                         ihid->irq_wake_enabled = false;
1099                 else
1100                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1101                                 wake_status);
1102         }
1103
1104         enable_irq(client->irq);
1105
1106         /* Instead of resetting device, simply powers the device on. This
1107          * solves "incomplete reports" on Raydium devices 2386:3118 and
1108          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1109          * data after a suspend/resume.
1110          *
1111          * However some ALPS touchpads generate IRQ storm without reset, so
1112          * let's still reset them here.
1113          */
1114         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1115                 ret = i2c_hid_hwreset(client);
1116         else
1117                 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
1118
1119         if (ret)
1120                 return ret;
1121
1122         if (hid->driver && hid->driver->reset_resume) {
1123                 ret = hid->driver->reset_resume(hid);
1124                 return ret;
1125         }
1126
1127         return 0;
1128 }
1129 #endif
1130
1131 const struct dev_pm_ops i2c_hid_core_pm = {
1132         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1133 };
1134 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1135
1136 MODULE_DESCRIPTION("HID over I2C core driver");
1137 MODULE_AUTHOR("Benjamin Tissoires <[email protected]>");
1138 MODULE_LICENSE("GPL");