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