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 #include <asm/unaligned.h>
  39
  40 #include "../hid-ids.h"
  41 #include "i2c-hid.h"
  42
  43 /* quirks to control the device */
  44 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV        BIT(0)
  45 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET        BIT(1)
  46 #define I2C_HID_QUIRK_BOGUS_IRQ                 BIT(4)
  47 #define I2C_HID_QUIRK_RESET_ON_RESUME           BIT(5)
  48 #define I2C_HID_QUIRK_BAD_INPUT_SIZE            BIT(6)
  49 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET     BIT(7)
  50
  51 /* Command opcodes */
  52 #define I2C_HID_OPCODE_RESET                    0x01
  53 #define I2C_HID_OPCODE_GET_REPORT               0x02
  54 #define I2C_HID_OPCODE_SET_REPORT               0x03
  55 #define I2C_HID_OPCODE_GET_IDLE                 0x04
  56 #define I2C_HID_OPCODE_SET_IDLE                 0x05
  57 #define I2C_HID_OPCODE_GET_PROTOCOL             0x06
  58 #define I2C_HID_OPCODE_SET_PROTOCOL             0x07
  59 #define I2C_HID_OPCODE_SET_POWER                0x08
  60
  61 /* flags */
  62 #define I2C_HID_STARTED         0
  63 #define I2C_HID_RESET_PENDING   1
  64 #define I2C_HID_READ_PENDING    2
  65
  66 #define I2C_HID_PWR_ON          0x00
  67 #define I2C_HID_PWR_SLEEP       0x01
  68
  69 /* debug option */
  70 static bool debug;
  71 module_param(debug, bool, 0444);
  72 MODULE_PARM_DESC(debug, "print a lot of debug information");
  73
  74 #define i2c_hid_dbg(ihid, fmt, arg...)                                    \
  75 do {                                                                      \
  76         if (debug)                                                        \
  77                 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
  78 } while (0)
  79
  80 struct i2c_hid_desc {
  81         __le16 wHIDDescLength;
  82         __le16 bcdVersion;
  83         __le16 wReportDescLength;
  84         __le16 wReportDescRegister;
  85         __le16 wInputRegister;
  86         __le16 wMaxInputLength;
  87         __le16 wOutputRegister;
  88         __le16 wMaxOutputLength;
  89         __le16 wCommandRegister;
  90         __le16 wDataRegister;
  91         __le16 wVendorID;
  92         __le16 wProductID;
  93         __le16 wVersionID;
  94         __le32 reserved;
  95 } __packed;
  96
  97 /* The main device structure */
  98 struct i2c_hid {
  99         struct i2c_client       *client;        /* i2c client */
 100         struct hid_device       *hid;   /* pointer to corresponding HID dev */
 101         struct i2c_hid_desc hdesc;              /* the HID Descriptor */
 102         __le16                  wHIDDescRegister; /* location of the i2c
 103                                                    * register of the HID
 104                                                    * descriptor. */
 105         unsigned int            bufsize;        /* i2c buffer size */
 106         u8                      *inbuf;         /* Input buffer */
 107         u8                      *rawbuf;        /* Raw Input buffer */
 108         u8                      *cmdbuf;        /* Command buffer */
 109
 110         unsigned long           flags;          /* device flags */
 111         unsigned long           quirks;         /* Various quirks */
 112
 113         wait_queue_head_t       wait;           /* For waiting the interrupt */
 114
 115         bool                    irq_wake_enabled;
 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                 pm_wakeup_event(&ihid->client->dev, 0);
 558
 559                 hid_input_report(ihid->hid, HID_INPUT_REPORT,
 560                                 ihid->inbuf + sizeof(__le16),
 561                                 ret_size - sizeof(__le16), 1);
 562         }
 563
 564         return;
 565 }
 566
 567 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 568 {
 569         struct i2c_hid *ihid = dev_id;
 570
 571         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 572                 return IRQ_HANDLED;
 573
 574         i2c_hid_get_input(ihid);
 575
 576         return IRQ_HANDLED;
 577 }
 578
 579 static int i2c_hid_get_report_length(struct hid_report *report)
 580 {
 581         return ((report->size - 1) >> 3) + 1 +
 582                 report->device->report_enum[report->type].numbered + 2;
 583 }
 584
 585 /*
 586  * Traverse the supplied list of reports and find the longest
 587  */
 588 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 589                 unsigned int *max)
 590 {
 591         struct hid_report *report;
 592         unsigned int size;
 593
 594         /* We should not rely on wMaxInputLength, as some devices may set it to
 595          * a wrong length. */
 596         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 597                 size = i2c_hid_get_report_length(report);
 598                 if (*max < size)
 599                         *max = size;
 600         }
 601 }
 602
 603 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 604 {
 605         kfree(ihid->inbuf);
 606         kfree(ihid->rawbuf);
 607         kfree(ihid->cmdbuf);
 608         ihid->inbuf = NULL;
 609         ihid->rawbuf = NULL;
 610         ihid->cmdbuf = NULL;
 611         ihid->bufsize = 0;
 612 }
 613
 614 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 615 {
 616         /*
 617          * The worst case is computed from the set_report command with a
 618          * reportID > 15 and the maximum report length.
 619          */
 620         int cmd_len = sizeof(__le16) +  /* command register */
 621                       sizeof(u8) +      /* encoded report type/ID */
 622                       sizeof(u8) +      /* opcode */
 623                       sizeof(u8) +      /* optional 3rd byte report ID */
 624                       sizeof(__le16) +  /* data register */
 625                       sizeof(__le16) +  /* report data size */
 626                       sizeof(u8) +      /* report ID if numbered report */
 627                       report_size;
 628
 629         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 630         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 631         ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
 632
 633         if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
 634                 i2c_hid_free_buffers(ihid);
 635                 return -ENOMEM;
 636         }
 637
 638         ihid->bufsize = report_size;
 639
 640         return 0;
 641 }
 642
 643 static int i2c_hid_get_raw_report(struct hid_device *hid,
 644                                   u8 report_type, u8 report_id,
 645                                   u8 *buf, size_t count)
 646 {
 647         struct i2c_client *client = hid->driver_data;
 648         struct i2c_hid *ihid = i2c_get_clientdata(client);
 649         int ret_count;
 650
 651         if (report_type == HID_OUTPUT_REPORT)
 652                 return -EINVAL;
 653
 654         /*
 655          * In case of unnumbered reports the response from the device will
 656          * not have the report ID that the upper layers expect, so we need
 657          * to stash it the buffer ourselves and adjust the data size.
 658          */
 659         if (!report_id) {
 660                 buf[0] = 0;
 661                 buf++;
 662                 count--;
 663         }
 664
 665         ret_count = i2c_hid_get_report(ihid,
 666                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 667                         report_id, buf, count);
 668
 669         if (ret_count > 0 && !report_id)
 670                 ret_count++;
 671
 672         return ret_count;
 673 }
 674
 675 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
 676                                      const u8 *buf, size_t count, bool do_set)
 677 {
 678         struct i2c_client *client = hid->driver_data;
 679         struct i2c_hid *ihid = i2c_get_clientdata(client);
 680         int report_id = buf[0];
 681         int ret;
 682
 683         if (report_type == HID_INPUT_REPORT)
 684                 return -EINVAL;
 685
 686         mutex_lock(&ihid->reset_lock);
 687
 688         /*
 689          * Note that both numbered and unnumbered reports passed here
 690          * are supposed to have report ID stored in the 1st byte of the
 691          * buffer, so we strip it off unconditionally before passing payload
 692          * to i2c_hid_set_or_send_report which takes care of encoding
 693          * everything properly.
 694          */
 695         ret = i2c_hid_set_or_send_report(ihid,
 696                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 697                                 report_id, buf + 1, count - 1, do_set);
 698
 699         if (ret >= 0)
 700                 ret++; /* add report_id to the number of transferred bytes */
 701
 702         mutex_unlock(&ihid->reset_lock);
 703
 704         return ret;
 705 }
 706
 707 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
 708 {
 709         return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
 710                                          false);
 711 }
 712
 713 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 714                                __u8 *buf, size_t len, unsigned char rtype,
 715                                int reqtype)
 716 {
 717         switch (reqtype) {
 718         case HID_REQ_GET_REPORT:
 719                 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
 720         case HID_REQ_SET_REPORT:
 721                 if (buf[0] != reportnum)
 722                         return -EINVAL;
 723                 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
 724         default:
 725                 return -EIO;
 726         }
 727 }
 728
 729 static int i2c_hid_parse(struct hid_device *hid)
 730 {
 731         struct i2c_client *client = hid->driver_data;
 732         struct i2c_hid *ihid = i2c_get_clientdata(client);
 733         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 734         unsigned int rsize;
 735         char *rdesc;
 736         int ret;
 737         int tries = 3;
 738         char *use_override;
 739
 740         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 741
 742         rsize = le16_to_cpu(hdesc->wReportDescLength);
 743         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 744                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 745                 return -EINVAL;
 746         }
 747
 748         do {
 749                 ret = i2c_hid_hwreset(ihid);
 750                 if (ret)
 751                         msleep(1000);
 752         } while (tries-- > 0 && ret);
 753
 754         if (ret)
 755                 return ret;
 756
 757         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 758                                                                 &rsize);
 759
 760         if (use_override) {
 761                 rdesc = use_override;
 762                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 763         } else {
 764                 rdesc = kzalloc(rsize, GFP_KERNEL);
 765
 766                 if (!rdesc) {
 767                         dbg_hid("couldn't allocate rdesc memory\n");
 768                         return -ENOMEM;
 769                 }
 770
 771                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 772
 773                 ret = i2c_hid_read_register(ihid,
 774                                             ihid->hdesc.wReportDescRegister,
 775                                             rdesc, rsize);
 776                 if (ret) {
 777                         hid_err(hid, "reading report descriptor failed\n");
 778                         kfree(rdesc);
 779                         return -EIO;
 780                 }
 781         }
 782
 783         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 784
 785         ret = hid_parse_report(hid, rdesc, rsize);
 786         if (!use_override)
 787                 kfree(rdesc);
 788
 789         if (ret) {
 790                 dbg_hid("parsing report descriptor failed\n");
 791                 return ret;
 792         }
 793
 794         return 0;
 795 }
 796
 797 static int i2c_hid_start(struct hid_device *hid)
 798 {
 799         struct i2c_client *client = hid->driver_data;
 800         struct i2c_hid *ihid = i2c_get_clientdata(client);
 801         int ret;
 802         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 803
 804         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 805         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 806         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 807
 808         if (bufsize > ihid->bufsize) {
 809                 disable_irq(client->irq);
 810                 i2c_hid_free_buffers(ihid);
 811
 812                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 813                 enable_irq(client->irq);
 814
 815                 if (ret)
 816                         return ret;
 817         }
 818
 819         return 0;
 820 }
 821
 822 static void i2c_hid_stop(struct hid_device *hid)
 823 {
 824         hid->claimed = 0;
 825 }
 826
 827 static int i2c_hid_open(struct hid_device *hid)
 828 {
 829         struct i2c_client *client = hid->driver_data;
 830         struct i2c_hid *ihid = i2c_get_clientdata(client);
 831
 832         set_bit(I2C_HID_STARTED, &ihid->flags);
 833         return 0;
 834 }
 835
 836 static void i2c_hid_close(struct hid_device *hid)
 837 {
 838         struct i2c_client *client = hid->driver_data;
 839         struct i2c_hid *ihid = i2c_get_clientdata(client);
 840
 841         clear_bit(I2C_HID_STARTED, &ihid->flags);
 842 }
 843
 844 struct hid_ll_driver i2c_hid_ll_driver = {
 845         .parse = i2c_hid_parse,
 846         .start = i2c_hid_start,
 847         .stop = i2c_hid_stop,
 848         .open = i2c_hid_open,
 849         .close = i2c_hid_close,
 850         .output_report = i2c_hid_output_report,
 851         .raw_request = i2c_hid_raw_request,
 852 };
 853 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
 854
 855 static int i2c_hid_init_irq(struct i2c_client *client)
 856 {
 857         struct i2c_hid *ihid = i2c_get_clientdata(client);
 858         unsigned long irqflags = 0;
 859         int ret;
 860
 861         dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
 862
 863         if (!irq_get_trigger_type(client->irq))
 864                 irqflags = IRQF_TRIGGER_LOW;
 865
 866         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 867                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 868         if (ret < 0) {
 869                 dev_warn(&client->dev,
 870                         "Could not register for %s interrupt, irq = %d,"
 871                         " ret = %d\n",
 872                         client->name, client->irq, ret);
 873
 874                 return ret;
 875         }
 876
 877         return 0;
 878 }
 879
 880 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 881 {
 882         struct i2c_client *client = ihid->client;
 883         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 884         unsigned int dsize;
 885         int error;
 886
 887         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 888         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 889                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 890                 ihid->hdesc =
 891                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 892         } else {
 893                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 894                 error = i2c_hid_read_register(ihid,
 895                                               ihid->wHIDDescRegister,
 896                                               &ihid->hdesc,
 897                                               sizeof(ihid->hdesc));
 898                 if (error) {
 899                         dev_err(&ihid->client->dev,
 900                                 "failed to fetch HID descriptor: %d\n",
 901                                 error);
 902                         return -ENODEV;
 903                 }
 904         }
 905
 906         /* Validate the length of HID descriptor, the 4 first bytes:
 907          * bytes 0-1 -> length
 908          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 909         /* check bcdVersion == 1.0 */
 910         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 911                 dev_err(&ihid->client->dev,
 912                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 913                         le16_to_cpu(hdesc->bcdVersion));
 914                 return -ENODEV;
 915         }
 916
 917         /* Descriptor length should be 30 bytes as per the specification */
 918         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 919         if (dsize != sizeof(struct i2c_hid_desc)) {
 920                 dev_err(&ihid->client->dev,
 921                         "weird size of HID descriptor (%u)\n", dsize);
 922                 return -ENODEV;
 923         }
 924         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
 925         return 0;
 926 }
 927
 928 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 929 {
 930         if (!ihid->ops->power_up)
 931                 return 0;
 932
 933         return ihid->ops->power_up(ihid->ops);
 934 }
 935
 936 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 937 {
 938         if (!ihid->ops->power_down)
 939                 return;
 940
 941         ihid->ops->power_down(ihid->ops);
 942 }
 943
 944 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 945 {
 946         if (!ihid->ops->shutdown_tail)
 947                 return;
 948
 949         ihid->ops->shutdown_tail(ihid->ops);
 950 }
 951
 952 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 953                        u16 hid_descriptor_address, u32 quirks)
 954 {
 955         int ret;
 956         struct i2c_hid *ihid;
 957         struct hid_device *hid;
 958
 959         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 960
 961         if (!client->irq) {
 962                 dev_err(&client->dev,
 963                         "HID over i2c has not been provided an Int IRQ\n");
 964                 return -EINVAL;
 965         }
 966
 967         if (client->irq < 0) {
 968                 if (client->irq != -EPROBE_DEFER)
 969                         dev_err(&client->dev,
 970                                 "HID over i2c doesn't have a valid IRQ\n");
 971                 return client->irq;
 972         }
 973
 974         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 975         if (!ihid)
 976                 return -ENOMEM;
 977
 978         ihid->ops = ops;
 979
 980         ret = i2c_hid_core_power_up(ihid);
 981         if (ret)
 982                 return ret;
 983
 984         i2c_set_clientdata(client, ihid);
 985
 986         ihid->client = client;
 987
 988         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 989
 990         init_waitqueue_head(&ihid->wait);
 991         mutex_init(&ihid->reset_lock);
 992
 993         /* we need to allocate the command buffer without knowing the maximum
 994          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 995          * real computation later. */
 996         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 997         if (ret < 0)
 998                 goto err_powered;
 999
1000         device_enable_async_suspend(&client->dev);
1001
1002         /* Make sure there is something at this address */
1003         ret = i2c_smbus_read_byte(client);
1004         if (ret < 0) {
1005                 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
1006                 ret = -ENXIO;
1007                 goto err_powered;
1008         }
1009
1010         ret = i2c_hid_fetch_hid_descriptor(ihid);
1011         if (ret < 0) {
1012                 dev_err(&client->dev,
1013                         "Failed to fetch the HID Descriptor\n");
1014                 goto err_powered;
1015         }
1016
1017         ret = i2c_hid_init_irq(client);
1018         if (ret < 0)
1019                 goto err_powered;
1020
1021         hid = hid_allocate_device();
1022         if (IS_ERR(hid)) {
1023                 ret = PTR_ERR(hid);
1024                 goto err_irq;
1025         }
1026
1027         ihid->hid = hid;
1028
1029         hid->driver_data = client;
1030         hid->ll_driver = &i2c_hid_ll_driver;
1031         hid->dev.parent = &client->dev;
1032         hid->bus = BUS_I2C;
1033         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1034         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1035         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1036
1037         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1038                  client->name, (u16)hid->vendor, (u16)hid->product);
1039         strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1040
1041         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1042
1043         ret = hid_add_device(hid);
1044         if (ret) {
1045                 if (ret != -ENODEV)
1046                         hid_err(client, "can't add hid device: %d\n", ret);
1047                 goto err_mem_free;
1048         }
1049
1050         hid->quirks |= quirks;
1051
1052         return 0;
1053
1054 err_mem_free:
1055         hid_destroy_device(hid);
1056
1057 err_irq:
1058         free_irq(client->irq, ihid);
1059
1060 err_powered:
1061         i2c_hid_core_power_down(ihid);
1062         i2c_hid_free_buffers(ihid);
1063         return ret;
1064 }
1065 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1066
1067 int i2c_hid_core_remove(struct i2c_client *client)
1068 {
1069         struct i2c_hid *ihid = i2c_get_clientdata(client);
1070         struct hid_device *hid;
1071
1072         hid = ihid->hid;
1073         hid_destroy_device(hid);
1074
1075         free_irq(client->irq, ihid);
1076
1077         if (ihid->bufsize)
1078                 i2c_hid_free_buffers(ihid);
1079
1080         i2c_hid_core_power_down(ihid);
1081
1082         return 0;
1083 }
1084 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1085
1086 void i2c_hid_core_shutdown(struct i2c_client *client)
1087 {
1088         struct i2c_hid *ihid = i2c_get_clientdata(client);
1089
1090         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1091         free_irq(client->irq, ihid);
1092
1093         i2c_hid_core_shutdown_tail(ihid);
1094 }
1095 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1096
1097 #ifdef CONFIG_PM_SLEEP
1098 static int i2c_hid_core_suspend(struct device *dev)
1099 {
1100         struct i2c_client *client = to_i2c_client(dev);
1101         struct i2c_hid *ihid = i2c_get_clientdata(client);
1102         struct hid_device *hid = ihid->hid;
1103         int ret;
1104         int wake_status;
1105
1106         ret = hid_driver_suspend(hid, PMSG_SUSPEND);
1107         if (ret < 0)
1108                 return ret;
1109
1110         /* Save some power */
1111         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1112
1113         disable_irq(client->irq);
1114
1115         if (device_may_wakeup(&client->dev)) {
1116                 wake_status = enable_irq_wake(client->irq);
1117                 if (!wake_status)
1118                         ihid->irq_wake_enabled = true;
1119                 else
1120                         hid_warn(hid, "Failed to enable irq wake: %d\n",
1121                                 wake_status);
1122         } else {
1123                 i2c_hid_core_power_down(ihid);
1124         }
1125
1126         return 0;
1127 }
1128
1129 static int i2c_hid_core_resume(struct device *dev)
1130 {
1131         int ret;
1132         struct i2c_client *client = to_i2c_client(dev);
1133         struct i2c_hid *ihid = i2c_get_clientdata(client);
1134         struct hid_device *hid = ihid->hid;
1135         int wake_status;
1136
1137         if (!device_may_wakeup(&client->dev)) {
1138                 i2c_hid_core_power_up(ihid);
1139         } else if (ihid->irq_wake_enabled) {
1140                 wake_status = disable_irq_wake(client->irq);
1141                 if (!wake_status)
1142                         ihid->irq_wake_enabled = false;
1143                 else
1144                         hid_warn(hid, "Failed to disable irq wake: %d\n",
1145                                 wake_status);
1146         }
1147
1148         enable_irq(client->irq);
1149
1150         /* Instead of resetting device, simply powers the device on. This
1151          * solves "incomplete reports" on Raydium devices 2386:3118 and
1152          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1153          * data after a suspend/resume.
1154          *
1155          * However some ALPS touchpads generate IRQ storm without reset, so
1156          * let's still reset them here.
1157          */
1158         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1159                 ret = i2c_hid_hwreset(ihid);
1160         else
1161                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1162
1163         if (ret)
1164                 return ret;
1165
1166         return hid_driver_reset_resume(hid);
1167 }
1168 #endif
1169
1170 const struct dev_pm_ops i2c_hid_core_pm = {
1171         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1172 };
1173 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1174
1175 MODULE_DESCRIPTION("HID over I2C core driver");
1176 MODULE_AUTHOR("Benjamin Tissoires <[email protected]>");
1177 MODULE_LICENSE("GPL");