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

   1 /*
   2  * HID over I2C protocol implementation
   3  *
   4  * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
   5  * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
   6  * Copyright (c) 2012 Red Hat, Inc
   7  *
   8  * This code is partly based on "USB HID support for Linux":
   9  *
  10  *  Copyright (c) 1999 Andreas Gal
  11  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
  12  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
  13  *  Copyright (c) 2007-2008 Oliver Neukum
  14  *  Copyright (c) 2006-2010 Jiri Kosina
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file COPYING in the main directory of this archive for
  18  * more details.
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/i2c.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/input.h>
  25 #include <linux/irq.h>
  26 #include <linux/delay.h>
  27 #include <linux/slab.h>
  28 #include <linux/pm.h>
  29 #include <linux/pm_wakeirq.h>
  30 #include <linux/device.h>
  31 #include <linux/wait.h>
  32 #include <linux/err.h>
  33 #include <linux/string.h>
  34 #include <linux/list.h>
  35 #include <linux/jiffies.h>
  36 #include <linux/kernel.h>
  37 #include <linux/hid.h>
  38 #include <linux/mutex.h>
  39 #include <asm/unaligned.h>
  40
  41 #include "../hid-ids.h"
  42 #include "i2c-hid.h"
  43
  44 /* quirks to control the device */
  45 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV        BIT(0)
  46 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET        BIT(1)
  47 #define I2C_HID_QUIRK_BOGUS_IRQ                 BIT(4)
  48 #define I2C_HID_QUIRK_RESET_ON_RESUME           BIT(5)
  49 #define I2C_HID_QUIRK_BAD_INPUT_SIZE            BIT(6)
  50 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET     BIT(7)
  51
  52 /* Command opcodes */
  53 #define I2C_HID_OPCODE_RESET                    0x01
  54 #define I2C_HID_OPCODE_GET_REPORT               0x02
  55 #define I2C_HID_OPCODE_SET_REPORT               0x03
  56 #define I2C_HID_OPCODE_GET_IDLE                 0x04
  57 #define I2C_HID_OPCODE_SET_IDLE                 0x05
  58 #define I2C_HID_OPCODE_GET_PROTOCOL             0x06
  59 #define I2C_HID_OPCODE_SET_PROTOCOL             0x07
  60 #define I2C_HID_OPCODE_SET_POWER                0x08
  61
  62 /* flags */
  63 #define I2C_HID_STARTED         0
  64 #define I2C_HID_RESET_PENDING   1
  65 #define I2C_HID_READ_PENDING    2
  66
  67 #define I2C_HID_PWR_ON          0x00
  68 #define I2C_HID_PWR_SLEEP       0x01
  69
  70 /* debug option */
  71 static bool debug;
  72 module_param(debug, bool, 0444);
  73 MODULE_PARM_DESC(debug, "print a lot of debug information");
  74
  75 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  76 do {                                                                      \
  77         if (debug)                                                        \
  78                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  79 } while (0)
  80
  81 struct i2c_hid_desc {
  82         __le16 wHIDDescLength;
  83         __le16 bcdVersion;
  84         __le16 wReportDescLength;
  85         __le16 wReportDescRegister;
  86         __le16 wInputRegister;
  87         __le16 wMaxInputLength;
  88         __le16 wOutputRegister;
  89         __le16 wMaxOutputLength;
  90         __le16 wCommandRegister;
  91         __le16 wDataRegister;
  92         __le16 wVendorID;
  93         __le16 wProductID;
  94         __le16 wVersionID;
  95         __le32 reserved;
  96 } __packed;
  97
  98 /* The main device structure */
  99 struct i2c_hid {
 100         struct i2c_client       *client;        /* i2c client */
 101         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 102         struct i2c_hid_desc hdesc;              /* the HID Descriptor */
 103         __le16                  wHIDDescRegister; /* location of the i2c
 104                                                    * register of the HID
 105                                                    * descriptor. */
 106         unsigned int            bufsize;        /* i2c buffer size */
 107         u8                      *inbuf;         /* Input buffer */
 108         u8                      *rawbuf;        /* Raw Input buffer */
 109         u8                      *cmdbuf;        /* Command buffer */
 110
 111         unsigned long           flags;          /* device flags */
 112         unsigned long           quirks;         /* Various quirks */
 113
 114         wait_queue_head_t       wait;           /* For waiting the interrupt */
 115
 116         struct mutex            reset_lock;
 117
 118         struct i2chid_ops       *ops;
 119 };
 120
 121 static const struct i2c_hid_quirks {
 122         __u16 idVendor;
 123         __u16 idProduct;
 124         __u32 quirks;
 125 } i2c_hid_quirks[] = {
 126         { USB_VENDOR_ID_WEIDA, HID_ANY_ID,
 127                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 128         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 129                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 130         { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
 131                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 132         { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
 133                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 134         { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
 135                  I2C_HID_QUIRK_RESET_ON_RESUME },
 136         { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
 137                  I2C_HID_QUIRK_RESET_ON_RESUME },
 138         { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 139                 I2C_HID_QUIRK_BAD_INPUT_SIZE },
 140         /*
 141          * Sending the wakeup after reset actually break ELAN touchscreen controller
 142          */
 143         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 144                  I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 145                  I2C_HID_QUIRK_BOGUS_IRQ },
 146         { 0, 0 }
 147 };
 148
 149 /*
 150  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 151  * @idVendor: the 16-bit vendor ID
 152  * @idProduct: the 16-bit product ID
 153  *
 154  * Returns: a u32 quirks value.
 155  */
 156 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 157 {
 158         u32 quirks = 0;
 159         int n;
 160
 161         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 162                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 163                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 164                      i2c_hid_quirks[n].idProduct == idProduct))
 165                         quirks = i2c_hid_quirks[n].quirks;
 166
 167         return quirks;
 168 }
 169
 170 static int i2c_hid_xfer(struct i2c_hid *ihid,
 171                         u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
 172 {
 173         struct i2c_client *client = ihid->client;
 174         struct i2c_msg msgs[2] = { 0 };
 175         int n = 0;
 176         int ret;
 177
 178         if (send_len) {
 179                 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
 180                             __func__, send_len, send_buf);
 181
 182                 msgs[n].addr = client->addr;
 183                 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
 184                 msgs[n].len = send_len;
 185                 msgs[n].buf = send_buf;
 186                 n++;
 187         }
 188
 189         if (recv_len) {
 190                 msgs[n].addr = client->addr;
 191                 msgs[n].flags = (client->flags & I2C_M_TEN) |
 192                                 I2C_M_RD | I2C_M_DMA_SAFE;
 193                 msgs[n].len = recv_len;
 194                 msgs[n].buf = recv_buf;
 195                 n++;
 196
 197                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 198         }
 199
 200         ret = i2c_transfer(client->adapter, msgs, n);
 201
 202         if (recv_len)
 203                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 204
 205         if (ret != n)
 206                 return ret < 0 ? ret : -EIO;
 207
 208         return 0;
 209 }
 210
 211 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
 212                                  void *buf, size_t len)
 213 {
 214         *(__le16 *)ihid->cmdbuf = reg;
 215
 216         return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
 217 }
 218
 219 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
 220                                      int report_type, int report_id)
 221 {
 222         size_t length = 0;
 223
 224         if (report_id < 0x0F) {
 225                 buf[length++] = report_type << 4 | report_id;
 226                 buf[length++] = opcode;
 227         } else {
 228                 buf[length++] = report_type << 4 | 0x0F;
 229                 buf[length++] = opcode;
 230                 buf[length++] = report_id;
 231         }
 232
 233         return length;
 234 }
 235
 236 static int i2c_hid_get_report(struct i2c_hid *ihid,
 237                               u8 report_type, u8 report_id,
 238                               u8 *recv_buf, size_t recv_len)
 239 {
 240         size_t length = 0;
 241         size_t ret_count;
 242         int error;
 243
 244         i2c_hid_dbg(ihid, "%s\n", __func__);
 245
 246         /* Command register goes first */
 247         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 248         length += sizeof(__le16);
 249         /* Next is GET_REPORT command */
 250         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 251                                          I2C_HID_OPCODE_GET_REPORT,
 252                                          report_type, report_id);
 253         /*
 254          * Device will send report data through data register. Because
 255          * command can be either 2 or 3 bytes destination for the data
 256          * register may be not aligned.
 257          */
 258         put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
 259                            ihid->cmdbuf + length);
 260         length += sizeof(__le16);
 261
 262         /*
 263          * In addition to report data device will supply data length
 264          * in the first 2 bytes of the response, so adjust .
 265          */
 266         error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
 267                              ihid->rawbuf, recv_len + sizeof(__le16));
 268         if (error) {
 269                 dev_err(&ihid->client->dev,
 270                         "failed to set a report to device: %d\n", error);
 271                 return error;
 272         }
 273
 274         /* The buffer is sufficiently aligned */
 275         ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
 276
 277         /* Check for empty report response */
 278         if (ret_count <= sizeof(__le16))
 279                 return 0;
 280
 281         recv_len = min(recv_len, ret_count - sizeof(__le16));
 282         memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
 283
 284         if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
 285                 dev_err(&ihid->client->dev,
 286                         "device returned incorrect report (%d vs %d expected)\n",
 287                         recv_buf[0], report_id);
 288                 return -EINVAL;
 289         }
 290
 291         return recv_len;
 292 }
 293
 294 static size_t i2c_hid_format_report(u8 *buf, int report_id,
 295                                     const u8 *data, size_t size)
 296 {
 297         size_t length = sizeof(__le16); /* reserve space to store size */
 298
 299         if (report_id)
 300                 buf[length++] = report_id;
 301
 302         memcpy(buf + length, data, size);
 303         length += size;
 304
 305         /* Store overall size in the beginning of the buffer */
 306         put_unaligned_le16(length, buf);
 307
 308         return length;
 309 }
 310
 311 /**
 312  * i2c_hid_set_or_send_report: forward an incoming report to the device
 313  * @ihid: the i2c hid device
 314  * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 315  * @report_id: the report ID
 316  * @buf: the actual data to transfer, without the report ID
 317  * @data_len: size of buf
 318  * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
 319  */
 320 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
 321                                       u8 report_type, u8 report_id,
 322                                       const u8 *buf, size_t data_len,
 323                                       bool do_set)
 324 {
 325         size_t length = 0;
 326         int error;
 327
 328         i2c_hid_dbg(ihid, "%s\n", __func__);
 329
 330         if (data_len > ihid->bufsize)
 331                 return -EINVAL;
 332
 333         if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
 334                 return -ENOSYS;
 335
 336         if (do_set) {
 337                 /* Command register goes first */
 338                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 339                 length += sizeof(__le16);
 340                 /* Next is SET_REPORT command */
 341                 length += i2c_hid_encode_command(ihid->cmdbuf + length,
 342                                                  I2C_HID_OPCODE_SET_REPORT,
 343                                                  report_type, report_id);
 344                 /*
 345                  * Report data will go into the data register. Because
 346                  * command can be either 2 or 3 bytes destination for
 347                  * the data register may be not aligned.
 348                 */
 349                 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
 350                                    ihid->cmdbuf + length);
 351                 length += sizeof(__le16);
 352         } else {
 353                 /*
 354                  * With simple "send report" all data goes into the output
 355                  * register.
 356                  */
 357                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
 358                 length += sizeof(__le16);
 359         }
 360
 361         length += i2c_hid_format_report(ihid->cmdbuf + length,
 362                                         report_id, buf, data_len);
 363
 364         error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 365         if (error) {
 366                 dev_err(&ihid->client->dev,
 367                         "failed to set a report to device: %d\n", error);
 368                 return error;
 369         }
 370
 371         return data_len;
 372 }
 373
 374 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
 375 {
 376         size_t length;
 377
 378         /* SET_POWER uses command register */
 379         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 380         length = sizeof(__le16);
 381
 382         /* Now the command itself */
 383         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 384                                          I2C_HID_OPCODE_SET_POWER,
 385                                          0, power_state);
 386
 387         return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 388 }
 389
 390 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
 391 {
 392         int ret;
 393
 394         i2c_hid_dbg(ihid, "%s\n", __func__);
 395
 396         /*
 397          * Some devices require to send a command to wakeup before power on.
 398          * The call will get a return value (EREMOTEIO) but device will be
 399          * triggered and activated. After that, it goes like a normal device.
 400          */
 401         if (power_state == I2C_HID_PWR_ON &&
 402             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 403                 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
 404
 405                 /* Device was already activated */
 406                 if (!ret)
 407                         goto set_pwr_exit;
 408         }
 409
 410         ret = i2c_hid_set_power_command(ihid, power_state);
 411         if (ret)
 412                 dev_err(&ihid->client->dev,
 413                         "failed to change power setting.\n");
 414
 415 set_pwr_exit:
 416
 417         /*
 418          * The HID over I2C specification states that if a DEVICE needs time
 419          * after the PWR_ON request, it should utilise CLOCK stretching.
 420          * However, it has been observered that the Windows driver provides a
 421          * 1ms sleep between the PWR_ON and RESET requests.
 422          * According to Goodix Windows even waits 60 ms after (other?)
 423          * PWR_ON requests. Testing has confirmed that several devices
 424          * will not work properly without a delay after a PWR_ON request.
 425          */
 426         if (!ret && power_state == I2C_HID_PWR_ON)
 427                 msleep(60);
 428
 429         return ret;
 430 }
 431
 432 static int i2c_hid_execute_reset(struct i2c_hid *ihid)
 433 {
 434         size_t length = 0;
 435         int ret;
 436
 437         i2c_hid_dbg(ihid, "resetting...\n");
 438
 439         /* Prepare reset command. Command register goes first. */
 440         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 441         length += sizeof(__le16);
 442         /* Next is RESET command itself */
 443         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 444                                          I2C_HID_OPCODE_RESET, 0, 0);
 445
 446         set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 447
 448         ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 449         if (ret) {
 450                 dev_err(&ihid->client->dev, "failed to reset device.\n");
 451                 goto out;
 452         }
 453
 454         if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
 455                 msleep(100);
 456                 goto out;
 457         }
 458
 459         i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 460         if (!wait_event_timeout(ihid->wait,
 461                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 462                                 msecs_to_jiffies(5000))) {
 463                 ret = -ENODATA;
 464                 goto out;
 465         }
 466         i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 467
 468 out:
 469         clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 470         return ret;
 471 }
 472
 473 static int i2c_hid_hwreset(struct i2c_hid *ihid)
 474 {
 475         int ret;
 476
 477         i2c_hid_dbg(ihid, "%s\n", __func__);
 478
 479         /*
 480          * This prevents sending feature reports while the device is
 481          * being reset. Otherwise we may lose the reset complete
 482          * interrupt.
 483          */
 484         mutex_lock(&ihid->reset_lock);
 485
 486         ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 487         if (ret)
 488                 goto out_unlock;
 489
 490         ret = i2c_hid_execute_reset(ihid);
 491         if (ret) {
 492                 dev_err(&ihid->client->dev,
 493                         "failed to reset device: %d\n", ret);
 494                 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 495                 goto out_unlock;
 496         }
 497
 498         /* At least some SIS devices need this after reset */
 499         if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
 500                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 501
 502 out_unlock:
 503         mutex_unlock(&ihid->reset_lock);
 504         return ret;
 505 }
 506
 507 static void i2c_hid_get_input(struct i2c_hid *ihid)
 508 {
 509         u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 510         u16 ret_size;
 511         int ret;
 512
 513         if (size > ihid->bufsize)
 514                 size = ihid->bufsize;
 515
 516         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 517         if (ret != size) {
 518                 if (ret < 0)
 519                         return;
 520
 521                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 522                         __func__, ret, size);
 523                 return;
 524         }
 525
 526         /* Receiving buffer is properly aligned */
 527         ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
 528         if (!ret_size) {
 529                 /* host or device initiated RESET completed */
 530                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 531                         wake_up(&ihid->wait);
 532                 return;
 533         }
 534
 535         if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
 536                 dev_warn_once(&ihid->client->dev,
 537                               "%s: IRQ triggered but there's no data\n",
 538                               __func__);
 539                 return;
 540         }
 541
 542         if (ret_size > size || ret_size < sizeof(__le16)) {
 543                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 544                         *(__le16 *)ihid->inbuf = cpu_to_le16(size);
 545                         ret_size = size;
 546                 } else {
 547                         dev_err(&ihid->client->dev,
 548                                 "%s: incomplete report (%d/%d)\n",
 549                                 __func__, size, ret_size);
 550                         return;
 551                 }
 552         }
 553
 554         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 555
 556         if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
 557                 if (ihid->hid->group != HID_GROUP_RMI)
 558                         pm_wakeup_event(&ihid->client->dev, 0);
 559
 560                 hid_input_report(ihid->hid, HID_INPUT_REPORT,
 561                                 ihid->inbuf + sizeof(__le16),
 562                                 ret_size - sizeof(__le16), 1);
 563         }
 564
 565         return;
 566 }
 567
 568 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 569 {
 570         struct i2c_hid *ihid = dev_id;
 571
 572         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 573                 return IRQ_HANDLED;
 574
 575         i2c_hid_get_input(ihid);
 576
 577         return IRQ_HANDLED;
 578 }
 579
 580 static int i2c_hid_get_report_length(struct hid_report *report)
 581 {
 582         return ((report->size - 1) >> 3) + 1 +
 583                 report->device->report_enum[report->type].numbered + 2;
 584 }
 585
 586 /*
 587  * Traverse the supplied list of reports and find the longest
 588  */
 589 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 590                 unsigned int *max)
 591 {
 592         struct hid_report *report;
 593         unsigned int size;
 594
 595         /* We should not rely on wMaxInputLength, as some devices may set it to
 596          * a wrong length. */
 597         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 598                 size = i2c_hid_get_report_length(report);
 599                 if (*max < size)
 600                         *max = size;
 601         }
 602 }
 603
 604 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 605 {
 606         kfree(ihid->inbuf);
 607         kfree(ihid->rawbuf);
 608         kfree(ihid->cmdbuf);
 609         ihid->inbuf = NULL;
 610         ihid->rawbuf = NULL;
 611         ihid->cmdbuf = NULL;
 612         ihid->bufsize = 0;
 613 }
 614
 615 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 616 {
 617         /*
 618          * The worst case is computed from the set_report command with a
 619          * reportID > 15 and the maximum report length.
 620          */
 621         int cmd_len = sizeof(__le16) +  /* command register */
 622                       sizeof(u8) +      /* encoded report type/ID */
 623                       sizeof(u8) +      /* opcode */
 624                       sizeof(u8) +      /* optional 3rd byte report ID */
 625                       sizeof(__le16) +  /* data register */
 626                       sizeof(__le16) +  /* report data size */
 627                       sizeof(u8) +      /* report ID if numbered report */
 628                       report_size;
 629
 630         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 631         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 632         ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
 633
 634         if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
 635                 i2c_hid_free_buffers(ihid);
 636                 return -ENOMEM;
 637         }
 638
 639         ihid->bufsize = report_size;
 640
 641         return 0;
 642 }
 643
 644 static int i2c_hid_get_raw_report(struct hid_device *hid,
 645                                   u8 report_type, u8 report_id,
 646                                   u8 *buf, size_t count)
 647 {
 648         struct i2c_client *client = hid->driver_data;
 649         struct i2c_hid *ihid = i2c_get_clientdata(client);
 650         int ret_count;
 651
 652         if (report_type == HID_OUTPUT_REPORT)
 653                 return -EINVAL;
 654
 655         /*
 656          * In case of unnumbered reports the response from the device will
 657          * not have the report ID that the upper layers expect, so we need
 658          * to stash it the buffer ourselves and adjust the data size.
 659          */
 660         if (!report_id) {
 661                 buf[0] = 0;
 662                 buf++;
 663                 count--;
 664         }
 665
 666         ret_count = i2c_hid_get_report(ihid,
 667                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 668                         report_id, buf, count);
 669
 670         if (ret_count > 0 && !report_id)
 671                 ret_count++;
 672
 673         return ret_count;
 674 }
 675
 676 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
 677                                      const u8 *buf, size_t count, bool do_set)
 678 {
 679         struct i2c_client *client = hid->driver_data;
 680         struct i2c_hid *ihid = i2c_get_clientdata(client);
 681         int report_id = buf[0];
 682         int ret;
 683
 684         if (report_type == HID_INPUT_REPORT)
 685                 return -EINVAL;
 686
 687         mutex_lock(&ihid->reset_lock);
 688
 689         /*
 690          * Note that both numbered and unnumbered reports passed here
 691          * are supposed to have report ID stored in the 1st byte of the
 692          * buffer, so we strip it off unconditionally before passing payload
 693          * to i2c_hid_set_or_send_report which takes care of encoding
 694          * everything properly.
 695          */
 696         ret = i2c_hid_set_or_send_report(ihid,
 697                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 698                                 report_id, buf + 1, count - 1, do_set);
 699
 700         if (ret >= 0)
 701                 ret++; /* add report_id to the number of transferred bytes */
 702
 703         mutex_unlock(&ihid->reset_lock);
 704
 705         return ret;
 706 }
 707
 708 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
 709 {
 710         return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
 711                                          false);
 712 }
 713
 714 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 715                                __u8 *buf, size_t len, unsigned char rtype,
 716                                int reqtype)
 717 {
 718         switch (reqtype) {
 719         case HID_REQ_GET_REPORT:
 720                 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
 721         case HID_REQ_SET_REPORT:
 722                 if (buf[0] != reportnum)
 723                         return -EINVAL;
 724                 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
 725         default:
 726                 return -EIO;
 727         }
 728 }
 729
 730 static int i2c_hid_parse(struct hid_device *hid)
 731 {
 732         struct i2c_client *client = hid->driver_data;
 733         struct i2c_hid *ihid = i2c_get_clientdata(client);
 734         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 735         unsigned int rsize;
 736         char *rdesc;
 737         int ret;
 738         int tries = 3;
 739         char *use_override;
 740
 741         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 742
 743         rsize = le16_to_cpu(hdesc->wReportDescLength);
 744         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 745                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 746                 return -EINVAL;
 747         }
 748
 749         do {
 750                 ret = i2c_hid_hwreset(ihid);
 751                 if (ret)
 752                         msleep(1000);
 753         } while (tries-- > 0 && ret);
 754
 755         if (ret)
 756                 return ret;
 757
 758         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 759                                                                 &rsize);
 760
 761         if (use_override) {
 762                 rdesc = use_override;
 763                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 764         } else {
 765                 rdesc = kzalloc(rsize, GFP_KERNEL);
 766
 767                 if (!rdesc) {
 768                         dbg_hid("couldn't allocate rdesc memory\n");
 769                         return -ENOMEM;
 770                 }
 771
 772                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 773
 774                 ret = i2c_hid_read_register(ihid,
 775                                             ihid->hdesc.wReportDescRegister,
 776                                             rdesc, rsize);
 777                 if (ret) {
 778                         hid_err(hid, "reading report descriptor failed\n");
 779                         kfree(rdesc);
 780                         return -EIO;
 781                 }
 782         }
 783
 784         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 785
 786         ret = hid_parse_report(hid, rdesc, rsize);
 787         if (!use_override)
 788                 kfree(rdesc);
 789
 790         if (ret) {
 791                 dbg_hid("parsing report descriptor failed\n");
 792                 return ret;
 793         }
 794
 795         return 0;
 796 }
 797
 798 static int i2c_hid_start(struct hid_device *hid)
 799 {
 800         struct i2c_client *client = hid->driver_data;
 801         struct i2c_hid *ihid = i2c_get_clientdata(client);
 802         int ret;
 803         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 804
 805         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 806         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 807         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 808
 809         if (bufsize > ihid->bufsize) {
 810                 disable_irq(client->irq);
 811                 i2c_hid_free_buffers(ihid);
 812
 813                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 814                 enable_irq(client->irq);
 815
 816                 if (ret)
 817                         return ret;
 818         }
 819
 820         return 0;
 821 }
 822
 823 static void i2c_hid_stop(struct hid_device *hid)
 824 {
 825         hid->claimed = 0;
 826 }
 827
 828 static int i2c_hid_open(struct hid_device *hid)
 829 {
 830         struct i2c_client *client = hid->driver_data;
 831         struct i2c_hid *ihid = i2c_get_clientdata(client);
 832
 833         set_bit(I2C_HID_STARTED, &ihid->flags);
 834         return 0;
 835 }
 836
 837 static void i2c_hid_close(struct hid_device *hid)
 838 {
 839         struct i2c_client *client = hid->driver_data;
 840         struct i2c_hid *ihid = i2c_get_clientdata(client);
 841
 842         clear_bit(I2C_HID_STARTED, &ihid->flags);
 843 }
 844
 845 struct hid_ll_driver i2c_hid_ll_driver = {
 846         .parse = i2c_hid_parse,
 847         .start = i2c_hid_start,
 848         .stop = i2c_hid_stop,
 849         .open = i2c_hid_open,
 850         .close = i2c_hid_close,
 851         .output_report = i2c_hid_output_report,
 852         .raw_request = i2c_hid_raw_request,
 853 };
 854 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 855
 856 static int i2c_hid_init_irq(struct i2c_client *client)
 857 {
 858         struct i2c_hid *ihid = i2c_get_clientdata(client);
 859         unsigned long irqflags = 0;
 860         int ret;
 861
 862         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 863
 864         if (!irq_get_trigger_type(client->irq))
 865                 irqflags = IRQF_TRIGGER_LOW;
 866
 867         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 868                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 869         if (ret < 0) {
 870                 dev_warn(&client->dev,
 871                         "Could not register for %s interrupt, irq = %d,"
 872                         " ret = %d\n",
 873                         client->name, client->irq, ret);
 874
 875                 return ret;
 876         }
 877
 878         return 0;
 879 }
 880
 881 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 882 {
 883         struct i2c_client *client = ihid->client;
 884         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 885         unsigned int dsize;
 886         int error;
 887
 888         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 889         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 890                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 891                 ihid->hdesc =
 892                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 893         } else {
 894                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 895                 error = i2c_hid_read_register(ihid,
 896                                               ihid->wHIDDescRegister,
 897                                               &ihid->hdesc,
 898                                               sizeof(ihid->hdesc));
 899                 if (error) {
 900                         dev_err(&ihid->client->dev,
 901                                 "failed to fetch HID descriptor: %d\n",
 902                                 error);
 903                         return -ENODEV;
 904                 }
 905         }
 906
 907         /* Validate the length of HID descriptor, the 4 first bytes:
 908          * bytes 0-1 -> length
 909          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 910         /* check bcdVersion == 1.0 */
 911         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 912                 dev_err(&ihid->client->dev,
 913                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 914                         le16_to_cpu(hdesc->bcdVersion));
 915                 return -ENODEV;
 916         }
 917
 918         /* Descriptor length should be 30 bytes as per the specification */
 919         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 920         if (dsize != sizeof(struct i2c_hid_desc)) {
 921                 dev_err(&ihid->client->dev,
 922                         "weird size of HID descriptor (%u)\n", dsize);
 923                 return -ENODEV;
 924         }
 925         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
 926         return 0;
 927 }
 928
 929 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 930 {
 931         if (!ihid->ops->power_up)
 932                 return 0;
 933
 934         return ihid->ops->power_up(ihid->ops);
 935 }
 936
 937 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 938 {
 939         if (!ihid->ops->power_down)
 940                 return;
 941
 942         ihid->ops->power_down(ihid->ops);
 943 }
 944
 945 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 946 {
 947         if (!ihid->ops->shutdown_tail)
 948                 return;
 949
 950         ihid->ops->shutdown_tail(ihid->ops);
 951 }
 952
 953 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 954                        u16 hid_descriptor_address, u32 quirks)
 955 {
 956         int ret;
 957         struct i2c_hid *ihid;
 958         struct hid_device *hid;
 959
 960         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 961
 962         if (!client->irq) {
 963                 dev_err(&client->dev,
 964                         "HID over i2c has not been provided an Int IRQ\n");
 965                 return -EINVAL;
 966         }
 967
 968         if (client->irq < 0) {
 969                 if (client->irq != -EPROBE_DEFER)
 970                         dev_err(&client->dev,
 971                                 "HID over i2c doesn't have a valid IRQ\n");
 972                 return client->irq;
 973         }
 974
 975         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 976         if (!ihid)
 977                 return -ENOMEM;
 978
 979         ihid->ops = ops;
 980
 981         ret = i2c_hid_core_power_up(ihid);
 982         if (ret)
 983                 return ret;
 984
 985         i2c_set_clientdata(client, ihid);
 986
 987         ihid->client = client;
 988
 989         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 990
 991         init_waitqueue_head(&ihid->wait);
 992         mutex_init(&ihid->reset_lock);
 993
 994         /* we need to allocate the command buffer without knowing the maximum
 995          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 996          * real computation later. */
 997         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 998         if (ret < 0)
 999                 goto err_powered;
1000
1001         device_enable_async_suspend(&client->dev);
1002
1003         /* Make sure there is something at this address */
1004         ret = i2c_smbus_read_byte(client);
1005         if (ret < 0) {
1006                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
1007                 ret = -ENXIO;
1008                 goto err_powered;
1009         }
1010
1011         ret = i2c_hid_fetch_hid_descriptor(ihid);
1012         if (ret < 0) {
1013                 dev_err(&client->dev,
1014                         "Failed to fetch the HID Descriptor\n");
1015                 goto err_powered;
1016         }
1017
1018         ret = i2c_hid_init_irq(client);
1019         if (ret < 0)
1020                 goto err_powered;
1021
1022         hid = hid_allocate_device();
1023         if (IS_ERR(hid)) {
1024                 ret = PTR_ERR(hid);
1025                 goto err_irq;
1026         }
1027
1028         ihid->hid = hid;
1029
1030         hid->driver_data = client;
1031         hid->ll_driver = &i2c_hid_ll_driver;
1032         hid->dev.parent = &client->dev;
1033         hid->bus = BUS_I2C;
1034         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1035         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1036         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1037
1038         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1039                  client->name, (u16)hid->vendor, (u16)hid->product);
1040         strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1041
1042         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1043
1044         ret = hid_add_device(hid);
1045         if (ret) {
1046                 if (ret != -ENODEV)
1047                         hid_err(client, "can't add hid device: %d\n", ret);
1048                 goto err_mem_free;
1049         }
1050
1051         hid->quirks |= quirks;
1052
1053         return 0;
1054
1055 err_mem_free:
1056         hid_destroy_device(hid);
1057
1058 err_irq:
1059         free_irq(client->irq, ihid);
1060
1061 err_powered:
1062         i2c_hid_core_power_down(ihid);
1063         i2c_hid_free_buffers(ihid);
1064         return ret;
1065 }
1066 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1067
1068 void i2c_hid_core_remove(struct i2c_client *client)
1069 {
1070         struct i2c_hid *ihid = i2c_get_clientdata(client);
1071         struct hid_device *hid;
1072
1073         hid = ihid->hid;
1074         hid_destroy_device(hid);
1075
1076         free_irq(client->irq, ihid);
1077
1078         if (ihid->bufsize)
1079                 i2c_hid_free_buffers(ihid);
1080
1081         i2c_hid_core_power_down(ihid);
1082 }
1083 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1084
1085 void i2c_hid_core_shutdown(struct i2c_client *client)
1086 {
1087         struct i2c_hid *ihid = i2c_get_clientdata(client);
1088
1089         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1090         free_irq(client->irq, ihid);
1091
1092         i2c_hid_core_shutdown_tail(ihid);
1093 }
1094 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1095
1096 #ifdef CONFIG_PM_SLEEP
1097 static int i2c_hid_core_suspend(struct device *dev)
1098 {
1099         struct i2c_client *client = to_i2c_client(dev);
1100         struct i2c_hid *ihid = i2c_get_clientdata(client);
1101         struct hid_device *hid = ihid->hid;
1102         int ret;
1103
1104         ret = hid_driver_suspend(hid, PMSG_SUSPEND);
1105         if (ret < 0)
1106                 return ret;
1107
1108         /* Save some power */
1109         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1110
1111         disable_irq(client->irq);
1112
1113         if (!device_may_wakeup(&client->dev))
1114                 i2c_hid_core_power_down(ihid);
1115
1116         return 0;
1117 }
1118
1119 static int i2c_hid_core_resume(struct device *dev)
1120 {
1121         int ret;
1122         struct i2c_client *client = to_i2c_client(dev);
1123         struct i2c_hid *ihid = i2c_get_clientdata(client);
1124         struct hid_device *hid = ihid->hid;
1125
1126         if (!device_may_wakeup(&client->dev))
1127                 i2c_hid_core_power_up(ihid);
1128
1129         enable_irq(client->irq);
1130
1131         /* Instead of resetting device, simply powers the device on. This
1132          * solves "incomplete reports" on Raydium devices 2386:3118 and
1133          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1134          * data after a suspend/resume.
1135          *
1136          * However some ALPS touchpads generate IRQ storm without reset, so
1137          * let's still reset them here.
1138          */
1139         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1140                 ret = i2c_hid_hwreset(ihid);
1141         else
1142                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1143
1144         if (ret)
1145                 return ret;
1146
1147         return hid_driver_reset_resume(hid);
1148 }
1149 #endif
1150
1151 const struct dev_pm_ops i2c_hid_core_pm = {
1152         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1153 };
1154 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1155
1156 MODULE_DESCRIPTION("HID over I2C core driver");
1157 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1158 MODULE_LICENSE("GPL");