drivers/hid/i2c-hid/i2c-hid.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/delay.h>
  26 #include <linux/slab.h>
  27 #include <linux/pm.h>
  28 #include <linux/pm_runtime.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 #include <linux/acpi.h>
  39 #include <linux/of.h>
  40 #include <linux/gpio/consumer.h>
  41 #include <linux/fb.h>
  42 #include <linux/notifier.h>
  43 #include <linux/rk_keys.h>
  44
  45 #include <linux/i2c/i2c-hid.h>
  46
  47 /* flags */
  48 #define I2C_HID_STARTED         0
  49 #define I2C_HID_RESET_PENDING   1
  50 #define I2C_HID_READ_PENDING    2
  51
  52 #define I2C_HID_PWR_ON          0x00
  53 #define I2C_HID_PWR_SLEEP       0x01
  54
  55 /* debug option */
  56 static bool debug;
  57 module_param(debug, bool, 0444);
  58 MODULE_PARM_DESC(debug, "print a lot of debug information");
  59
  60 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  61 do {                                                                      \
  62         if (debug)                                                        \
  63                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  64 } while (0)
  65
  66 struct i2c_hid_desc {
  67         __le16 wHIDDescLength;
  68         __le16 bcdVersion;
  69         __le16 wReportDescLength;
  70         __le16 wReportDescRegister;
  71         __le16 wInputRegister;
  72         __le16 wMaxInputLength;
  73         __le16 wOutputRegister;
  74         __le16 wMaxOutputLength;
  75         __le16 wCommandRegister;
  76         __le16 wDataRegister;
  77         __le16 wVendorID;
  78         __le16 wProductID;
  79         __le16 wVersionID;
  80         __le32 reserved;
  81 } __packed;
  82
  83 struct i2c_hid_cmd {
  84         unsigned int registerIndex;
  85         __u8 opcode;
  86         unsigned int length;
  87         bool wait;
  88 };
  89
  90 union command {
  91         u8 data[0];
  92         struct cmd {
  93                 __le16 reg;
  94                 __u8 reportTypeID;
  95                 __u8 opcode;
  96         } __packed c;
  97 };
  98
  99 #define I2C_HID_CMD(opcode_) \
 100         .opcode = opcode_, .length = 4, \
 101         .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
 102
 103 /* fetch HID descriptor */
 104 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
 105 /* fetch report descriptors */
 106 static const struct i2c_hid_cmd hid_report_descr_cmd = {
 107                 .registerIndex = offsetof(struct i2c_hid_desc,
 108                         wReportDescRegister),
 109                 .opcode = 0x00,
 110                 .length = 2 };
 111 /* commands */
 112 static const struct i2c_hid_cmd hid_reset_cmd =         { I2C_HID_CMD(0x01),
 113                                                           .wait = true };
 114 static const struct i2c_hid_cmd hid_get_report_cmd =    { I2C_HID_CMD(0x02) };
 115 static const struct i2c_hid_cmd hid_set_report_cmd =    { I2C_HID_CMD(0x03) };
 116 static const struct i2c_hid_cmd hid_set_power_cmd =     { I2C_HID_CMD(0x08) };
 117 static const struct i2c_hid_cmd hid_no_cmd =            { .length = 0 };
 118
 119 /*
 120  * These definitions are not used here, but are defined by the spec.
 121  * Keeping them here for documentation purposes.
 122  *
 123  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 124  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 125  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 126  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 127  */
 128
 129 static DEFINE_MUTEX(i2c_hid_open_mut);
 130
 131 /* The main device structure */
 132 struct i2c_hid {
 133         struct i2c_client       *client;        /* i2c client */
 134         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 135         union {
 136                 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
 137                 struct i2c_hid_desc hdesc;      /* the HID Descriptor */
 138         };
 139         __le16                  wHIDDescRegister; /* location of the i2c
 140                                                    * register of the HID
 141                                                    * descriptor. */
 142         unsigned int            bufsize;        /* i2c buffer size */
 143         char                    *inbuf;         /* Input buffer */
 144         char                    *rawbuf;        /* Raw Input buffer */
 145         char                    *cmdbuf;        /* Command buffer */
 146         char                    *argsbuf;       /* Command arguments buffer */
 147
 148         unsigned long           flags;          /* device flags */
 149
 150         wait_queue_head_t       wait;           /* For waiting the interrupt */
 151         struct gpio_desc        *desc;
 152         int                     irq;
 153
 154         struct i2c_hid_platform_data pdata;
 155
 156         bool                    irq_wake_enabled;
 157
 158         struct notifier_block fb_notif;
 159         int is_suspend;
 160 };
 161
 162 static int ihid_fb_notifier_callback(struct notifier_block *self,
 163                                      unsigned long action, void *data)
 164 {
 165         struct i2c_hid *ihid;
 166         struct fb_event *event = data;
 167
 168         ihid = container_of(self, struct i2c_hid, fb_notif);
 169
 170         if (action == FB_EARLY_EVENT_BLANK) {
 171                 switch (*((int *)event->data)) {
 172                 case FB_BLANK_UNBLANK:
 173                         break;
 174                 default:
 175                         ihid->is_suspend = 1;
 176                         break;
 177                 }
 178         } else if (action == FB_EVENT_BLANK) {
 179                 switch (*((int *)event->data)) {
 180                 case FB_BLANK_UNBLANK:
 181                         ihid->is_suspend = 0;
 182                         break;
 183                 default:
 184                         break;
 185                 }
 186         }
 187
 188         return NOTIFY_OK;
 189 }
 190
 191 static int __i2c_hid_command(struct i2c_client *client,
 192                 const struct i2c_hid_cmd *command, u8 reportID,
 193                 u8 reportType, u8 *args, int args_len,
 194                 unsigned char *buf_recv, int data_len)
 195 {
 196         struct i2c_hid *ihid = i2c_get_clientdata(client);
 197         union command *cmd = (union command *)ihid->cmdbuf;
 198         int ret;
 199         struct i2c_msg msg[2];
 200         int msg_num = 1;
 201
 202         int length = command->length;
 203         bool wait = command->wait;
 204         unsigned int registerIndex = command->registerIndex;
 205
 206         /* special case for hid_descr_cmd */
 207         if (command == &hid_descr_cmd) {
 208                 cmd->c.reg = ihid->wHIDDescRegister;
 209         } else {
 210                 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
 211                 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
 212         }
 213
 214         if (length > 2) {
 215                 cmd->c.opcode = command->opcode;
 216                 cmd->c.reportTypeID = reportID | reportType << 4;
 217         }
 218
 219         memcpy(cmd->data + length, args, args_len);
 220         length += args_len;
 221
 222         i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
 223
 224         msg[0].addr = client->addr;
 225         msg[0].flags = client->flags & I2C_M_TEN;
 226         msg[0].len = length;
 227         msg[0].buf = cmd->data;
 228         if (data_len > 0) {
 229                 msg[1].addr = client->addr;
 230                 msg[1].flags = client->flags & I2C_M_TEN;
 231                 msg[1].flags |= I2C_M_RD;
 232                 msg[1].len = data_len;
 233                 msg[1].buf = buf_recv;
 234                 msg_num = 2;
 235                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 236         }
 237
 238         if (wait)
 239                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 240
 241         ret = i2c_transfer(client->adapter, msg, msg_num);
 242
 243         if (data_len > 0)
 244                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 245
 246         if (ret != msg_num)
 247                 return ret < 0 ? ret : -EIO;
 248
 249         ret = 0;
 250
 251         if (wait) {
 252                 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 253                 if (!wait_event_timeout(ihid->wait,
 254                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 255                                 msecs_to_jiffies(5000)))
 256                         ret = -ENODATA;
 257                 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 258         }
 259
 260         return ret;
 261 }
 262
 263 static int i2c_hid_command(struct i2c_client *client,
 264                 const struct i2c_hid_cmd *command,
 265                 unsigned char *buf_recv, int data_len)
 266 {
 267         return __i2c_hid_command(client, command, 0, 0, NULL, 0,
 268                                 buf_recv, data_len);
 269 }
 270
 271 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 272                 u8 reportID, unsigned char *buf_recv, int data_len)
 273 {
 274         struct i2c_hid *ihid = i2c_get_clientdata(client);
 275         u8 args[3];
 276         int ret;
 277         int args_len = 0;
 278         u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 279
 280         i2c_hid_dbg(ihid, "%s\n", __func__);
 281
 282         if (reportID >= 0x0F) {
 283                 args[args_len++] = reportID;
 284                 reportID = 0x0F;
 285         }
 286
 287         args[args_len++] = readRegister & 0xFF;
 288         args[args_len++] = readRegister >> 8;
 289
 290         ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
 291                 reportType, args, args_len, buf_recv, data_len);
 292         if (ret) {
 293                 dev_err(&client->dev,
 294                         "failed to retrieve report from device.\n");
 295                 return ret;
 296         }
 297
 298         return 0;
 299 }
 300
 301 /**
 302  * i2c_hid_set_or_send_report: forward an incoming report to the device
 303  * @client: the i2c_client of the device
 304  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 305  * @reportID: the report ID
 306  * @buf: the actual data to transfer, without the report ID
 307  * @len: size of buf
 308  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 309  */
 310 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
 311                 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 312 {
 313         struct i2c_hid *ihid = i2c_get_clientdata(client);
 314         u8 *args = ihid->argsbuf;
 315         const struct i2c_hid_cmd *hidcmd;
 316         int ret;
 317         u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 318         u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
 319         u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
 320         u16 size;
 321         int args_len;
 322         int index = 0;
 323
 324         i2c_hid_dbg(ihid, "%s\n", __func__);
 325
 326         if (data_len > ihid->bufsize)
 327                 return -EINVAL;
 328
 329         size =          2                       /* size */ +
 330                         (reportID ? 1 : 0)      /* reportID */ +
 331                         data_len                /* buf */;
 332         args_len =      (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
 333                         2                       /* dataRegister */ +
 334                         size                    /* args */;
 335
 336         if (!use_data && maxOutputLength == 0)
 337                 return -ENOSYS;
 338
 339         if (reportID >= 0x0F) {
 340                 args[index++] = reportID;
 341                 reportID = 0x0F;
 342         }
 343
 344         /*
 345          * use the data register for feature reports or if the device does not
 346          * support the output register
 347          */
 348         if (use_data) {
 349                 args[index++] = dataRegister & 0xFF;
 350                 args[index++] = dataRegister >> 8;
 351                 hidcmd = &hid_set_report_cmd;
 352         } else {
 353                 args[index++] = outputRegister & 0xFF;
 354                 args[index++] = outputRegister >> 8;
 355                 hidcmd = &hid_no_cmd;
 356         }
 357
 358         args[index++] = size & 0xFF;
 359         args[index++] = size >> 8;
 360
 361         if (reportID)
 362                 args[index++] = reportID;
 363
 364         memcpy(&args[index], buf, data_len);
 365
 366         ret = __i2c_hid_command(client, hidcmd, reportID,
 367                 reportType, args, args_len, NULL, 0);
 368         if (ret) {
 369                 dev_err(&client->dev, "failed to set a report to device.\n");
 370                 return ret;
 371         }
 372
 373         return data_len;
 374 }
 375
 376 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 377 {
 378         struct i2c_hid *ihid = i2c_get_clientdata(client);
 379         int ret;
 380
 381         i2c_hid_dbg(ihid, "%s\n", __func__);
 382
 383         ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 384                 0, NULL, 0, NULL, 0);
 385         if (ret)
 386                 dev_err(&client->dev, "failed to change power setting.\n");
 387
 388         return ret;
 389 }
 390
 391 static int i2c_hid_hwreset(struct i2c_client *client)
 392 {
 393         struct i2c_hid *ihid = i2c_get_clientdata(client);
 394         int ret;
 395
 396         i2c_hid_dbg(ihid, "%s\n", __func__);
 397
 398         ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 399         if (ret)
 400                 return ret;
 401
 402         i2c_hid_dbg(ihid, "resetting...\n");
 403
 404         ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
 405         if (ret) {
 406                 dev_err(&client->dev, "failed to reset device.\n");
 407                 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
 408                 return ret;
 409         }
 410
 411         return 0;
 412 }
 413
 414 static void i2c_hid_get_input(struct i2c_hid *ihid)
 415 {
 416         int ret, ret_size;
 417         int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 418
 419         if (size > ihid->bufsize)
 420                 size = ihid->bufsize;
 421
 422         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 423         if (ret != size) {
 424                 if (ret < 0)
 425                         return;
 426
 427                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 428                         __func__, ret, size);
 429                 return;
 430         }
 431
 432         ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
 433
 434         if (!ret_size) {
 435                 /* host or device initiated RESET completed */
 436                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 437                         wake_up(&ihid->wait);
 438                 return;
 439         }
 440
 441         if (ret_size > size) {
 442                 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 443                         __func__, size, ret_size);
 444                 return;
 445         }
 446
 447         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 448
 449         if (test_bit(I2C_HID_STARTED, &ihid->flags))
 450                 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
 451                                 ret_size - 2, 1);
 452
 453         return;
 454 }
 455
 456 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 457 {
 458         struct i2c_hid *ihid = dev_id;
 459
 460         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 461                 return IRQ_HANDLED;
 462
 463         i2c_hid_get_input(ihid);
 464
 465         if (device_may_wakeup(&ihid->client->dev) && ihid->is_suspend == 1)
 466                 rk_send_wakeup_key();
 467
 468         return IRQ_HANDLED;
 469 }
 470
 471 static int i2c_hid_get_report_length(struct hid_report *report)
 472 {
 473         return ((report->size - 1) >> 3) + 1 +
 474                 report->device->report_enum[report->type].numbered + 2;
 475 }
 476
 477 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
 478         size_t bufsize)
 479 {
 480         struct hid_device *hid = report->device;
 481         struct i2c_client *client = hid->driver_data;
 482         struct i2c_hid *ihid = i2c_get_clientdata(client);
 483         unsigned int size, ret_size;
 484
 485         size = i2c_hid_get_report_length(report);
 486         if (i2c_hid_get_report(client,
 487                         report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 488                         report->id, buffer, size))
 489                 return;
 490
 491         i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
 492
 493         ret_size = buffer[0] | (buffer[1] << 8);
 494
 495         if (ret_size != size) {
 496                 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
 497                         __func__, size, ret_size);
 498                 return;
 499         }
 500
 501         /* hid->driver_lock is held as we are in probe function,
 502          * we just need to setup the input fields, so using
 503          * hid_report_raw_event is safe. */
 504         hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
 505 }
 506
 507 /*
 508  * Initialize all reports
 509  */
 510 static void i2c_hid_init_reports(struct hid_device *hid)
 511 {
 512         struct hid_report *report;
 513         struct i2c_client *client = hid->driver_data;
 514         struct i2c_hid *ihid = i2c_get_clientdata(client);
 515         u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
 516
 517         if (!inbuf) {
 518                 dev_err(&client->dev, "can not retrieve initial reports\n");
 519                 return;
 520         }
 521
 522         /*
 523          * The device must be powered on while we fetch initial reports
 524          * from it.
 525          */
 526         pm_runtime_get_sync(&client->dev);
 527
 528         list_for_each_entry(report,
 529                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 530                 i2c_hid_init_report(report, inbuf, ihid->bufsize);
 531
 532         pm_runtime_put(&client->dev);
 533
 534         kfree(inbuf);
 535 }
 536
 537 /*
 538  * Traverse the supplied list of reports and find the longest
 539  */
 540 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 541                 unsigned int *max)
 542 {
 543         struct hid_report *report;
 544         unsigned int size;
 545
 546         /* We should not rely on wMaxInputLength, as some devices may set it to
 547          * a wrong length. */
 548         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 549                 size = i2c_hid_get_report_length(report);
 550                 if (*max < size)
 551                         *max = size;
 552         }
 553 }
 554
 555 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 556 {
 557         kfree(ihid->inbuf);
 558         kfree(ihid->rawbuf);
 559         kfree(ihid->argsbuf);
 560         kfree(ihid->cmdbuf);
 561         ihid->inbuf = NULL;
 562         ihid->rawbuf = NULL;
 563         ihid->cmdbuf = NULL;
 564         ihid->argsbuf = NULL;
 565         ihid->bufsize = 0;
 566 }
 567
 568 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 569 {
 570         /* the worst case is computed from the set_report command with a
 571          * reportID > 15 and the maximum report length */
 572         int args_len = sizeof(__u8) + /* optional ReportID byte */
 573                        sizeof(__u16) + /* data register */
 574                        sizeof(__u16) + /* size of the report */
 575                        report_size; /* report */
 576
 577         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 578         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 579         ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
 580         ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
 581
 582         if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
 583                 i2c_hid_free_buffers(ihid);
 584                 return -ENOMEM;
 585         }
 586
 587         ihid->bufsize = report_size;
 588
 589         return 0;
 590 }
 591
 592 static int i2c_hid_get_raw_report(struct hid_device *hid,
 593                 unsigned char report_number, __u8 *buf, size_t count,
 594                 unsigned char report_type)
 595 {
 596         struct i2c_client *client = hid->driver_data;
 597         struct i2c_hid *ihid = i2c_get_clientdata(client);
 598         size_t ret_count, ask_count;
 599         int ret;
 600
 601         if (report_type == HID_OUTPUT_REPORT)
 602                 return -EINVAL;
 603
 604         /* +2 bytes to include the size of the reply in the query buffer */
 605         ask_count = min(count + 2, (size_t)ihid->bufsize);
 606
 607         ret = i2c_hid_get_report(client,
 608                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 609                         report_number, ihid->rawbuf, ask_count);
 610
 611         if (ret < 0)
 612                 return ret;
 613
 614         ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
 615
 616         if (ret_count <= 2)
 617                 return 0;
 618
 619         ret_count = min(ret_count, ask_count);
 620
 621         /* The query buffer contains the size, dropping it in the reply */
 622         count = min(count, ret_count - 2);
 623         memcpy(buf, ihid->rawbuf + 2, count);
 624
 625         return count;
 626 }
 627
 628 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 629                 size_t count, unsigned char report_type, bool use_data)
 630 {
 631         struct i2c_client *client = hid->driver_data;
 632         int report_id = buf[0];
 633         int ret;
 634
 635         if (report_type == HID_INPUT_REPORT)
 636                 return -EINVAL;
 637
 638         if (report_id) {
 639                 buf++;
 640                 count--;
 641         }
 642
 643         ret = i2c_hid_set_or_send_report(client,
 644                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 645                                 report_id, buf, count, use_data);
 646
 647         if (report_id && ret >= 0)
 648                 ret++; /* add report_id to the number of transfered bytes */
 649
 650         return ret;
 651 }
 652
 653 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
 654                 size_t count)
 655 {
 656         return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
 657                         false);
 658 }
 659
 660 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 661                                __u8 *buf, size_t len, unsigned char rtype,
 662                                int reqtype)
 663 {
 664         switch (reqtype) {
 665         case HID_REQ_GET_REPORT:
 666                 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 667         case HID_REQ_SET_REPORT:
 668                 if (buf[0] != reportnum)
 669                         return -EINVAL;
 670                 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
 671         default:
 672                 return -EIO;
 673         }
 674 }
 675
 676 static int i2c_hid_parse(struct hid_device *hid)
 677 {
 678         struct i2c_client *client = hid->driver_data;
 679         struct i2c_hid *ihid = i2c_get_clientdata(client);
 680         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 681         unsigned int rsize;
 682         char *rdesc;
 683         int ret;
 684         int tries = 3;
 685
 686         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 687
 688         rsize = le16_to_cpu(hdesc->wReportDescLength);
 689         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 690                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 691                 return -EINVAL;
 692         }
 693
 694         do {
 695                 ret = i2c_hid_hwreset(client);
 696                 if (ret)
 697                         msleep(1000);
 698         } while (tries-- > 0 && ret);
 699
 700         if (ret)
 701                 return ret;
 702
 703         rdesc = kzalloc(rsize, GFP_KERNEL);
 704
 705         if (!rdesc) {
 706                 dbg_hid("couldn't allocate rdesc memory\n");
 707                 return -ENOMEM;
 708         }
 709
 710         i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 711
 712         ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
 713         if (ret) {
 714                 hid_err(hid, "reading report descriptor failed\n");
 715                 kfree(rdesc);
 716                 return -EIO;
 717         }
 718
 719         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 720
 721         ret = hid_parse_report(hid, rdesc, rsize);
 722         kfree(rdesc);
 723         if (ret) {
 724                 dbg_hid("parsing report descriptor failed\n");
 725                 return ret;
 726         }
 727
 728         return 0;
 729 }
 730
 731 static int i2c_hid_start(struct hid_device *hid)
 732 {
 733         struct i2c_client *client = hid->driver_data;
 734         struct i2c_hid *ihid = i2c_get_clientdata(client);
 735         int ret;
 736         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 737
 738         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 739         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 740         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 741
 742         if (bufsize > ihid->bufsize) {
 743                 i2c_hid_free_buffers(ihid);
 744
 745                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 746
 747                 if (ret)
 748                         return ret;
 749         }
 750
 751         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 752                 i2c_hid_init_reports(hid);
 753
 754         return 0;
 755 }
 756
 757 static void i2c_hid_stop(struct hid_device *hid)
 758 {
 759         hid->claimed = 0;
 760 }
 761
 762 static int i2c_hid_open(struct hid_device *hid)
 763 {
 764         struct i2c_client *client = hid->driver_data;
 765         struct i2c_hid *ihid = i2c_get_clientdata(client);
 766         int ret = 0;
 767
 768         mutex_lock(&i2c_hid_open_mut);
 769         if (!hid->open++) {
 770                 ret = pm_runtime_get_sync(&client->dev);
 771                 if (ret < 0) {
 772                         hid->open--;
 773                         goto done;
 774                 }
 775                 set_bit(I2C_HID_STARTED, &ihid->flags);
 776         }
 777 done:
 778         mutex_unlock(&i2c_hid_open_mut);
 779         return ret < 0 ? ret : 0;
 780 }
 781
 782 static void i2c_hid_close(struct hid_device *hid)
 783 {
 784         struct i2c_client *client = hid->driver_data;
 785         struct i2c_hid *ihid = i2c_get_clientdata(client);
 786
 787         /* protecting hid->open to make sure we don't restart
 788          * data acquistion due to a resumption we no longer
 789          * care about
 790          */
 791         mutex_lock(&i2c_hid_open_mut);
 792         if (!--hid->open) {
 793                 clear_bit(I2C_HID_STARTED, &ihid->flags);
 794
 795                 /* Save some power */
 796                 pm_runtime_put(&client->dev);
 797         }
 798         mutex_unlock(&i2c_hid_open_mut);
 799 }
 800
 801 static int i2c_hid_power(struct hid_device *hid, int lvl)
 802 {
 803         struct i2c_client *client = hid->driver_data;
 804         struct i2c_hid *ihid = i2c_get_clientdata(client);
 805
 806         i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
 807
 808         switch (lvl) {
 809         case PM_HINT_FULLON:
 810                 pm_runtime_get_sync(&client->dev);
 811                 break;
 812         case PM_HINT_NORMAL:
 813                 pm_runtime_put(&client->dev);
 814                 break;
 815         }
 816         return 0;
 817 }
 818
 819 static struct hid_ll_driver i2c_hid_ll_driver = {
 820         .parse = i2c_hid_parse,
 821         .start = i2c_hid_start,
 822         .stop = i2c_hid_stop,
 823         .open = i2c_hid_open,
 824         .close = i2c_hid_close,
 825         .power = i2c_hid_power,
 826         .output_report = i2c_hid_output_report,
 827         .raw_request = i2c_hid_raw_request,
 828 };
 829
 830 static int i2c_hid_init_irq(struct i2c_client *client)
 831 {
 832         struct i2c_hid *ihid = i2c_get_clientdata(client);
 833         int ret;
 834
 835         dev_dbg(&client->dev, "Requesting IRQ: %d\n", ihid->irq);
 836
 837         ret = request_threaded_irq(ihid->irq, NULL, i2c_hid_irq,
 838                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 839                         client->name, ihid);
 840         if (ret < 0) {
 841                 dev_warn(&client->dev,
 842                         "Could not register for %s interrupt, irq = %d,"
 843                         " ret = %d\n",
 844                         client->name, ihid->irq, ret);
 845
 846                 return ret;
 847         }
 848
 849         return 0;
 850 }
 851
 852 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 853 {
 854         struct i2c_client *client = ihid->client;
 855         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 856         unsigned int dsize;
 857         int ret;
 858
 859         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 860         i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 861         ret = i2c_hid_command(client, &hid_descr_cmd, 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         /* Validate the length of HID descriptor, the 4 first bytes:
 869          * bytes 0-1 -> length
 870          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 871         /* check bcdVersion == 1.0 */
 872         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 873                 dev_err(&client->dev,
 874                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 875                         le16_to_cpu(hdesc->bcdVersion));
 876                 return -ENODEV;
 877         }
 878
 879         /* Descriptor length should be 30 bytes as per the specification */
 880         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 881         if (dsize != sizeof(struct i2c_hid_desc)) {
 882                 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
 883                         dsize);
 884                 return -ENODEV;
 885         }
 886         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
 887         return 0;
 888 }
 889
 890 #ifdef CONFIG_ACPI
 891
 892 /* Default GPIO mapping */
 893 static const struct acpi_gpio_params i2c_hid_irq_gpio = { 0, 0, true };
 894 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios[] = {
 895         { "gpios", &i2c_hid_irq_gpio, 1 },
 896         { },
 897 };
 898
 899 static int i2c_hid_acpi_pdata(struct i2c_client *client,
 900                 struct i2c_hid_platform_data *pdata)
 901 {
 902         static u8 i2c_hid_guid[] = {
 903                 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
 904                 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
 905         };
 906         union acpi_object *obj;
 907         struct acpi_device *adev;
 908         acpi_handle handle;
 909         int ret;
 910
 911         handle = ACPI_HANDLE(&client->dev);
 912         if (!handle || acpi_bus_get_device(handle, &adev))
 913                 return -ENODEV;
 914
 915         obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
 916                                       ACPI_TYPE_INTEGER);
 917         if (!obj) {
 918                 dev_err(&client->dev, "device _DSM execution failed\n");
 919                 return -ENODEV;
 920         }
 921
 922         pdata->hid_descriptor_address = obj->integer.value;
 923         ACPI_FREE(obj);
 924
 925         /* GPIOs are optional */
 926         ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
 927         return ret < 0 && ret != -ENXIO ? ret : 0;
 928 }
 929
 930 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 931         {"ACPI0C50", 0 },
 932         {"PNP0C50", 0 },
 933         { },
 934 };
 935 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 936 #else
 937 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
 938                 struct i2c_hid_platform_data *pdata)
 939 {
 940         return -ENODEV;
 941 }
 942 #endif
 943
 944 #ifdef CONFIG_OF
 945 static int i2c_hid_of_probe(struct i2c_client *client,
 946                 struct i2c_hid_platform_data *pdata)
 947 {
 948         struct device *dev = &client->dev;
 949         u32 val;
 950         int ret;
 951
 952         ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
 953         if (ret) {
 954                 dev_err(&client->dev, "HID register address not provided\n");
 955                 return -ENODEV;
 956         }
 957         if (val >> 16) {
 958                 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
 959                         val);
 960                 return -EINVAL;
 961         }
 962         pdata->hid_descriptor_address = val;
 963
 964         return 0;
 965 }
 966
 967 static const struct of_device_id i2c_hid_of_match[] = {
 968         { .compatible = "hid-over-i2c" },
 969         {},
 970 };
 971 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 972 #else
 973 static inline int i2c_hid_of_probe(struct i2c_client *client,
 974                 struct i2c_hid_platform_data *pdata)
 975 {
 976         return -ENODEV;
 977 }
 978 #endif
 979
 980 static int i2c_hid_probe(struct i2c_client *client,
 981                          const struct i2c_device_id *dev_id)
 982 {
 983         int ret;
 984         struct i2c_hid *ihid;
 985         struct hid_device *hid;
 986         __u16 hidRegister;
 987         struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
 988
 989         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 990
 991         ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
 992         if (!ihid)
 993                 return -ENOMEM;
 994
 995         if (client->dev.of_node) {
 996                 ret = i2c_hid_of_probe(client, &ihid->pdata);
 997                 if (ret)
 998                         goto err;
 999         } else if (!platform_data) {
1000                 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
1001                 if (ret) {
1002                         dev_err(&client->dev,
1003                                 "HID register address not provided\n");
1004                         goto err;
1005                 }
1006         } else {
1007                 ihid->pdata = *platform_data;
1008         }
1009
1010         if (client->irq > 0) {
1011                 ihid->irq = client->irq;
1012         } else if (ACPI_COMPANION(&client->dev)) {
1013                 ihid->desc = gpiod_get(&client->dev, NULL, GPIOD_IN);
1014                 if (IS_ERR(ihid->desc)) {
1015                         dev_err(&client->dev, "Failed to get GPIO interrupt\n");
1016                         return PTR_ERR(ihid->desc);
1017                 }
1018
1019                 ihid->irq = gpiod_to_irq(ihid->desc);
1020                 if (ihid->irq < 0) {
1021                         gpiod_put(ihid->desc);
1022                         dev_err(&client->dev, "Failed to convert GPIO to IRQ\n");
1023                         return ihid->irq;
1024                 }
1025         }
1026
1027         i2c_set_clientdata(client, ihid);
1028
1029         ihid->client = client;
1030
1031         hidRegister = ihid->pdata.hid_descriptor_address;
1032         ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1033
1034         init_waitqueue_head(&ihid->wait);
1035
1036         /* we need to allocate the command buffer without knowing the maximum
1037          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1038          * real computation later. */
1039         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1040         if (ret < 0)
1041                 goto err;
1042
1043         pm_runtime_get_noresume(&client->dev);
1044         pm_runtime_set_active(&client->dev);
1045         pm_runtime_enable(&client->dev);
1046
1047         ret = i2c_hid_fetch_hid_descriptor(ihid);
1048         if (ret < 0)
1049                 goto err_pm;
1050
1051         ret = i2c_hid_init_irq(client);
1052         if (ret < 0)
1053                 goto err_pm;
1054
1055         if (client->dev.of_node) {
1056                 ret = of_property_read_bool(client->dev.of_node, "hid-support-wakeup");
1057                 if (ret) {
1058                         device_init_wakeup(&client->dev, true);
1059                         ihid->is_suspend = 0;
1060                         ihid->fb_notif.notifier_call = ihid_fb_notifier_callback;
1061                         fb_register_client(&ihid->fb_notif);
1062                 }
1063         }
1064
1065         hid = hid_allocate_device();
1066         if (IS_ERR(hid)) {
1067                 ret = PTR_ERR(hid);
1068                 goto err_irq;
1069         }
1070
1071         ihid->hid = hid;
1072
1073         hid->driver_data = client;
1074         hid->ll_driver = &i2c_hid_ll_driver;
1075         hid->dev.parent = &client->dev;
1076         hid->bus = BUS_I2C;
1077         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1078         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1079         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1080
1081         snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1082                  client->name, hid->vendor, hid->product);
1083         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1084
1085         ret = hid_add_device(hid);
1086         if (ret) {
1087                 if (ret != -ENODEV)
1088                         hid_err(client, "can't add hid device: %d\n", ret);
1089                 goto err_mem_free;
1090         }
1091
1092         pm_runtime_put(&client->dev);
1093         return 0;
1094
1095 err_mem_free:
1096         hid_destroy_device(hid);
1097
1098 err_irq:
1099         free_irq(ihid->irq, ihid);
1100
1101 err_pm:
1102         pm_runtime_put_noidle(&client->dev);
1103         pm_runtime_disable(&client->dev);
1104
1105 err:
1106         if (ihid->desc)
1107                 gpiod_put(ihid->desc);
1108
1109         i2c_hid_free_buffers(ihid);
1110         kfree(ihid);
1111         return ret;
1112 }
1113
1114 static int i2c_hid_remove(struct i2c_client *client)
1115 {
1116         struct i2c_hid *ihid = i2c_get_clientdata(client);
1117         struct hid_device *hid;
1118
1119         pm_runtime_get_sync(&client->dev);
1120         pm_runtime_disable(&client->dev);
1121         pm_runtime_set_suspended(&client->dev);
1122         pm_runtime_put_noidle(&client->dev);
1123
1124         hid = ihid->hid;
1125         hid_destroy_device(hid);
1126
1127         free_irq(ihid->irq, ihid);
1128
1129         if (ihid->bufsize)
1130                 i2c_hid_free_buffers(ihid);
1131
1132         if (ihid->desc)
1133                 gpiod_put(ihid->desc);
1134
1135         kfree(ihid);
1136
1137         acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
1138
1139         return 0;
1140 }
1141
1142 #ifdef CONFIG_PM_SLEEP
1143 static int i2c_hid_suspend(struct device *dev)
1144 {
1145         struct i2c_client *client = to_i2c_client(dev);
1146         struct i2c_hid *ihid = i2c_get_clientdata(client);
1147         struct hid_device *hid = ihid->hid;
1148         int ret = 0;
1149         int wake_status;
1150
1151         if (hid->driver && hid->driver->suspend)
1152                 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1153
1154         disable_irq(ihid->irq);
1155         if (device_may_wakeup(&client->dev)) {
1156                 wake_status = enable_irq_wake(ihid->irq);
1157                 if (!wake_status)
1158                         ihid->irq_wake_enabled = true;
1159                 else
1160                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1161                                 wake_status);
1162         }
1163
1164         /* Save some power */
1165         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1166
1167         return ret;
1168 }
1169
1170 static int i2c_hid_resume(struct device *dev)
1171 {
1172         int ret;
1173         struct i2c_client *client = to_i2c_client(dev);
1174         struct i2c_hid *ihid = i2c_get_clientdata(client);
1175         struct hid_device *hid = ihid->hid;
1176         int wake_status;
1177
1178         enable_irq(ihid->irq);
1179         if (!device_may_wakeup(&client->dev)) {
1180                 ret = i2c_hid_hwreset(client);
1181                 if (ret)
1182                         return ret;
1183         }
1184
1185         if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1186                 wake_status = disable_irq_wake(ihid->irq);
1187                 if (!wake_status)
1188                         ihid->irq_wake_enabled = false;
1189                 else
1190                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1191                                 wake_status);
1192         }
1193
1194         if (hid->driver && hid->driver->reset_resume) {
1195                 ret = hid->driver->reset_resume(hid);
1196                 return ret;
1197         }
1198
1199         return 0;
1200 }
1201 #endif
1202
1203 #ifdef CONFIG_PM
1204 static int i2c_hid_runtime_suspend(struct device *dev)
1205 {
1206         struct i2c_client *client = to_i2c_client(dev);
1207         struct i2c_hid *ihid = i2c_get_clientdata(client);
1208
1209         i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1210         disable_irq(ihid->irq);
1211         return 0;
1212 }
1213
1214 static int i2c_hid_runtime_resume(struct device *dev)
1215 {
1216         struct i2c_client *client = to_i2c_client(dev);
1217         struct i2c_hid *ihid = i2c_get_clientdata(client);
1218
1219         enable_irq(ihid->irq);
1220         i2c_hid_set_power(client, I2C_HID_PWR_ON);
1221         return 0;
1222 }
1223 #endif
1224
1225 static const struct dev_pm_ops i2c_hid_pm = {
1226         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1227         SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1228                            NULL)
1229 };
1230
1231 static const struct i2c_device_id i2c_hid_id_table[] = {
1232         { "hid", 0 },
1233         { },
1234 };
1235 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1236
1237
1238 static struct i2c_driver i2c_hid_driver = {
1239         .driver = {
1240                 .name   = "i2c_hid",
1241                 .owner  = THIS_MODULE,
1242                 .pm     = &i2c_hid_pm,
1243                 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1244                 .of_match_table = of_match_ptr(i2c_hid_of_match),
1245         },
1246
1247         .probe          = i2c_hid_probe,
1248         .remove         = i2c_hid_remove,
1249
1250         .id_table       = i2c_hid_id_table,
1251 };
1252
1253 module_i2c_driver(i2c_hid_driver);
1254
1255 MODULE_DESCRIPTION("HID over I2C core driver");
1256 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1257 MODULE_LICENSE("GPL");