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 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__)
  71
  72 struct i2c_hid_desc {
  73         __le16 wHIDDescLength;
  74         __le16 bcdVersion;
  75         __le16 wReportDescLength;
  76         __le16 wReportDescRegister;
  77         __le16 wInputRegister;
  78         __le16 wMaxInputLength;
  79         __le16 wOutputRegister;
  80         __le16 wMaxOutputLength;
  81         __le16 wCommandRegister;
  82         __le16 wDataRegister;
  83         __le16 wVendorID;
  84         __le16 wProductID;
  85         __le16 wVersionID;
  86         __le32 reserved;
  87 } __packed;
  88
  89 /* The main device structure */
  90 struct i2c_hid {
  91         struct i2c_client       *client;        /* i2c client */
  92         struct hid_device       *hid;   /* pointer to corresponding HID dev */
  93         struct i2c_hid_desc hdesc;              /* the HID Descriptor */
  94         __le16                  wHIDDescRegister; /* location of the i2c
  95                                                    * register of the HID
  96                                                    * descriptor. */
  97         unsigned int            bufsize;        /* i2c buffer size */
  98         u8                      *inbuf;         /* Input buffer */
  99         u8                      *rawbuf;        /* Raw Input buffer */
 100         u8                      *cmdbuf;        /* Command buffer */
 101
 102         unsigned long           flags;          /* device flags */
 103         unsigned long           quirks;         /* Various quirks */
 104
 105         wait_queue_head_t       wait;           /* For waiting the interrupt */
 106
 107         struct mutex            reset_lock;
 108
 109         struct i2chid_ops       *ops;
 110 };
 111
 112 static const struct i2c_hid_quirks {
 113         __u16 idVendor;
 114         __u16 idProduct;
 115         __u32 quirks;
 116 } i2c_hid_quirks[] = {
 117         { USB_VENDOR_ID_WEIDA, HID_ANY_ID,
 118                 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
 119         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 120                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 121         { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
 122                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 123         { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
 124                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 125         { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
 126                  I2C_HID_QUIRK_RESET_ON_RESUME },
 127         { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
 128                  I2C_HID_QUIRK_RESET_ON_RESUME },
 129         { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 130                 I2C_HID_QUIRK_BAD_INPUT_SIZE },
 131         /*
 132          * Sending the wakeup after reset actually break ELAN touchscreen controller
 133          */
 134         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 135                  I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 136                  I2C_HID_QUIRK_BOGUS_IRQ },
 137         { 0, 0 }
 138 };
 139
 140 /*
 141  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 142  * @idVendor: the 16-bit vendor ID
 143  * @idProduct: the 16-bit product ID
 144  *
 145  * Returns: a u32 quirks value.
 146  */
 147 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 148 {
 149         u32 quirks = 0;
 150         int n;
 151
 152         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 153                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 154                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 155                      i2c_hid_quirks[n].idProduct == idProduct))
 156                         quirks = i2c_hid_quirks[n].quirks;
 157
 158         return quirks;
 159 }
 160
 161 static int i2c_hid_xfer(struct i2c_hid *ihid,
 162                         u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
 163 {
 164         struct i2c_client *client = ihid->client;
 165         struct i2c_msg msgs[2] = { 0 };
 166         int n = 0;
 167         int ret;
 168
 169         if (send_len) {
 170                 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
 171                             __func__, send_len, send_buf);
 172
 173                 msgs[n].addr = client->addr;
 174                 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
 175                 msgs[n].len = send_len;
 176                 msgs[n].buf = send_buf;
 177                 n++;
 178         }
 179
 180         if (recv_len) {
 181                 msgs[n].addr = client->addr;
 182                 msgs[n].flags = (client->flags & I2C_M_TEN) |
 183                                 I2C_M_RD | I2C_M_DMA_SAFE;
 184                 msgs[n].len = recv_len;
 185                 msgs[n].buf = recv_buf;
 186                 n++;
 187
 188                 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
 189         }
 190
 191         ret = i2c_transfer(client->adapter, msgs, n);
 192
 193         if (recv_len)
 194                 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
 195
 196         if (ret != n)
 197                 return ret < 0 ? ret : -EIO;
 198
 199         return 0;
 200 }
 201
 202 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
 203                                  void *buf, size_t len)
 204 {
 205         *(__le16 *)ihid->cmdbuf = reg;
 206
 207         return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
 208 }
 209
 210 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
 211                                      int report_type, int report_id)
 212 {
 213         size_t length = 0;
 214
 215         if (report_id < 0x0F) {
 216                 buf[length++] = report_type << 4 | report_id;
 217                 buf[length++] = opcode;
 218         } else {
 219                 buf[length++] = report_type << 4 | 0x0F;
 220                 buf[length++] = opcode;
 221                 buf[length++] = report_id;
 222         }
 223
 224         return length;
 225 }
 226
 227 static int i2c_hid_get_report(struct i2c_hid *ihid,
 228                               u8 report_type, u8 report_id,
 229                               u8 *recv_buf, size_t recv_len)
 230 {
 231         size_t length = 0;
 232         size_t ret_count;
 233         int error;
 234
 235         i2c_hid_dbg(ihid, "%s\n", __func__);
 236
 237         /* Command register goes first */
 238         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 239         length += sizeof(__le16);
 240         /* Next is GET_REPORT command */
 241         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 242                                          I2C_HID_OPCODE_GET_REPORT,
 243                                          report_type, report_id);
 244         /*
 245          * Device will send report data through data register. Because
 246          * command can be either 2 or 3 bytes destination for the data
 247          * register may be not aligned.
 248          */
 249         put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
 250                            ihid->cmdbuf + length);
 251         length += sizeof(__le16);
 252
 253         /*
 254          * In addition to report data device will supply data length
 255          * in the first 2 bytes of the response, so adjust .
 256          */
 257         error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
 258                              ihid->rawbuf, recv_len + sizeof(__le16));
 259         if (error) {
 260                 dev_err(&ihid->client->dev,
 261                         "failed to set a report to device: %d\n", error);
 262                 return error;
 263         }
 264
 265         /* The buffer is sufficiently aligned */
 266         ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
 267
 268         /* Check for empty report response */
 269         if (ret_count <= sizeof(__le16))
 270                 return 0;
 271
 272         recv_len = min(recv_len, ret_count - sizeof(__le16));
 273         memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
 274
 275         if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
 276                 dev_err(&ihid->client->dev,
 277                         "device returned incorrect report (%d vs %d expected)\n",
 278                         recv_buf[0], report_id);
 279                 return -EINVAL;
 280         }
 281
 282         return recv_len;
 283 }
 284
 285 static size_t i2c_hid_format_report(u8 *buf, int report_id,
 286                                     const u8 *data, size_t size)
 287 {
 288         size_t length = sizeof(__le16); /* reserve space to store size */
 289
 290         if (report_id)
 291                 buf[length++] = report_id;
 292
 293         memcpy(buf + length, data, size);
 294         length += size;
 295
 296         /* Store overall size in the beginning of the buffer */
 297         put_unaligned_le16(length, buf);
 298
 299         return length;
 300 }
 301
 302 /**
 303  * i2c_hid_set_or_send_report: forward an incoming report to the device
 304  * @ihid: the i2c hid device
 305  * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 306  * @report_id: the report ID
 307  * @buf: the actual data to transfer, without the report ID
 308  * @data_len: size of buf
 309  * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
 310  */
 311 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
 312                                       u8 report_type, u8 report_id,
 313                                       const u8 *buf, size_t data_len,
 314                                       bool do_set)
 315 {
 316         size_t length = 0;
 317         int error;
 318
 319         i2c_hid_dbg(ihid, "%s\n", __func__);
 320
 321         if (data_len > ihid->bufsize)
 322                 return -EINVAL;
 323
 324         if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
 325                 return -ENOSYS;
 326
 327         if (do_set) {
 328                 /* Command register goes first */
 329                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 330                 length += sizeof(__le16);
 331                 /* Next is SET_REPORT command */
 332                 length += i2c_hid_encode_command(ihid->cmdbuf + length,
 333                                                  I2C_HID_OPCODE_SET_REPORT,
 334                                                  report_type, report_id);
 335                 /*
 336                  * Report data will go into the data register. Because
 337                  * command can be either 2 or 3 bytes destination for
 338                  * the data register may be not aligned.
 339                 */
 340                 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
 341                                    ihid->cmdbuf + length);
 342                 length += sizeof(__le16);
 343         } else {
 344                 /*
 345                  * With simple "send report" all data goes into the output
 346                  * register.
 347                  */
 348                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
 349                 length += sizeof(__le16);
 350         }
 351
 352         length += i2c_hid_format_report(ihid->cmdbuf + length,
 353                                         report_id, buf, data_len);
 354
 355         error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 356         if (error) {
 357                 dev_err(&ihid->client->dev,
 358                         "failed to set a report to device: %d\n", error);
 359                 return error;
 360         }
 361
 362         return data_len;
 363 }
 364
 365 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
 366 {
 367         size_t length;
 368
 369         /* SET_POWER uses command register */
 370         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 371         length = sizeof(__le16);
 372
 373         /* Now the command itself */
 374         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 375                                          I2C_HID_OPCODE_SET_POWER,
 376                                          0, power_state);
 377
 378         return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 379 }
 380
 381 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
 382 {
 383         int ret;
 384
 385         i2c_hid_dbg(ihid, "%s\n", __func__);
 386
 387         /*
 388          * Some devices require to send a command to wakeup before power on.
 389          * The call will get a return value (EREMOTEIO) but device will be
 390          * triggered and activated. After that, it goes like a normal device.
 391          */
 392         if (power_state == I2C_HID_PWR_ON &&
 393             ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
 394                 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
 395
 396                 /* Device was already activated */
 397                 if (!ret)
 398                         goto set_pwr_exit;
 399         }
 400
 401         ret = i2c_hid_set_power_command(ihid, power_state);
 402         if (ret)
 403                 dev_err(&ihid->client->dev,
 404                         "failed to change power setting.\n");
 405
 406 set_pwr_exit:
 407
 408         /*
 409          * The HID over I2C specification states that if a DEVICE needs time
 410          * after the PWR_ON request, it should utilise CLOCK stretching.
 411          * However, it has been observered that the Windows driver provides a
 412          * 1ms sleep between the PWR_ON and RESET requests.
 413          * According to Goodix Windows even waits 60 ms after (other?)
 414          * PWR_ON requests. Testing has confirmed that several devices
 415          * will not work properly without a delay after a PWR_ON request.
 416          */
 417         if (!ret && power_state == I2C_HID_PWR_ON)
 418                 msleep(60);
 419
 420         return ret;
 421 }
 422
 423 static int i2c_hid_execute_reset(struct i2c_hid *ihid)
 424 {
 425         size_t length = 0;
 426         int ret;
 427
 428         i2c_hid_dbg(ihid, "resetting...\n");
 429
 430         /* Prepare reset command. Command register goes first. */
 431         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 432         length += sizeof(__le16);
 433         /* Next is RESET command itself */
 434         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 435                                          I2C_HID_OPCODE_RESET, 0, 0);
 436
 437         set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 438
 439         ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 440         if (ret) {
 441                 dev_err(&ihid->client->dev, "failed to reset device.\n");
 442                 goto out;
 443         }
 444
 445         if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
 446                 msleep(100);
 447                 goto out;
 448         }
 449
 450         i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 451         if (!wait_event_timeout(ihid->wait,
 452                                 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 453                                 msecs_to_jiffies(5000))) {
 454                 ret = -ENODATA;
 455                 goto out;
 456         }
 457         i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 458
 459 out:
 460         clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 461         return ret;
 462 }
 463
 464 static int i2c_hid_hwreset(struct i2c_hid *ihid)
 465 {
 466         int ret;
 467
 468         i2c_hid_dbg(ihid, "%s\n", __func__);
 469
 470         /*
 471          * This prevents sending feature reports while the device is
 472          * being reset. Otherwise we may lose the reset complete
 473          * interrupt.
 474          */
 475         mutex_lock(&ihid->reset_lock);
 476
 477         ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 478         if (ret)
 479                 goto out_unlock;
 480
 481         ret = i2c_hid_execute_reset(ihid);
 482         if (ret) {
 483                 dev_err(&ihid->client->dev,
 484                         "failed to reset device: %d\n", ret);
 485                 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 486                 goto out_unlock;
 487         }
 488
 489         /* At least some SIS devices need this after reset */
 490         if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
 491                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 492
 493 out_unlock:
 494         mutex_unlock(&ihid->reset_lock);
 495         return ret;
 496 }
 497
 498 static void i2c_hid_get_input(struct i2c_hid *ihid)
 499 {
 500         u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 501         u16 ret_size;
 502         int ret;
 503
 504         if (size > ihid->bufsize)
 505                 size = ihid->bufsize;
 506
 507         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 508         if (ret != size) {
 509                 if (ret < 0)
 510                         return;
 511
 512                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 513                         __func__, ret, size);
 514                 return;
 515         }
 516
 517         /* Receiving buffer is properly aligned */
 518         ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
 519         if (!ret_size) {
 520                 /* host or device initiated RESET completed */
 521                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 522                         wake_up(&ihid->wait);
 523                 return;
 524         }
 525
 526         if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
 527                 dev_warn_once(&ihid->client->dev,
 528                               "%s: IRQ triggered but there's no data\n",
 529                               __func__);
 530                 return;
 531         }
 532
 533         if (ret_size > size || ret_size < sizeof(__le16)) {
 534                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 535                         *(__le16 *)ihid->inbuf = cpu_to_le16(size);
 536                         ret_size = size;
 537                 } else {
 538                         dev_err(&ihid->client->dev,
 539                                 "%s: incomplete report (%d/%d)\n",
 540                                 __func__, size, ret_size);
 541                         return;
 542                 }
 543         }
 544
 545         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 546
 547         if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
 548                 if (ihid->hid->group != HID_GROUP_RMI)
 549                         pm_wakeup_event(&ihid->client->dev, 0);
 550
 551                 hid_input_report(ihid->hid, HID_INPUT_REPORT,
 552                                 ihid->inbuf + sizeof(__le16),
 553                                 ret_size - sizeof(__le16), 1);
 554         }
 555
 556         return;
 557 }
 558
 559 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 560 {
 561         struct i2c_hid *ihid = dev_id;
 562
 563         if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
 564                 return IRQ_HANDLED;
 565
 566         i2c_hid_get_input(ihid);
 567
 568         return IRQ_HANDLED;
 569 }
 570
 571 static int i2c_hid_get_report_length(struct hid_report *report)
 572 {
 573         return ((report->size - 1) >> 3) + 1 +
 574                 report->device->report_enum[report->type].numbered + 2;
 575 }
 576
 577 /*
 578  * Traverse the supplied list of reports and find the longest
 579  */
 580 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 581                 unsigned int *max)
 582 {
 583         struct hid_report *report;
 584         unsigned int size;
 585
 586         /* We should not rely on wMaxInputLength, as some devices may set it to
 587          * a wrong length. */
 588         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 589                 size = i2c_hid_get_report_length(report);
 590                 if (*max < size)
 591                         *max = size;
 592         }
 593 }
 594
 595 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 596 {
 597         kfree(ihid->inbuf);
 598         kfree(ihid->rawbuf);
 599         kfree(ihid->cmdbuf);
 600         ihid->inbuf = NULL;
 601         ihid->rawbuf = NULL;
 602         ihid->cmdbuf = NULL;
 603         ihid->bufsize = 0;
 604 }
 605
 606 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 607 {
 608         /*
 609          * The worst case is computed from the set_report command with a
 610          * reportID > 15 and the maximum report length.
 611          */
 612         int cmd_len = sizeof(__le16) +  /* command register */
 613                       sizeof(u8) +      /* encoded report type/ID */
 614                       sizeof(u8) +      /* opcode */
 615                       sizeof(u8) +      /* optional 3rd byte report ID */
 616                       sizeof(__le16) +  /* data register */
 617                       sizeof(__le16) +  /* report data size */
 618                       sizeof(u8) +      /* report ID if numbered report */
 619                       report_size;
 620
 621         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 622         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 623         ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
 624
 625         if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
 626                 i2c_hid_free_buffers(ihid);
 627                 return -ENOMEM;
 628         }
 629
 630         ihid->bufsize = report_size;
 631
 632         return 0;
 633 }
 634
 635 static int i2c_hid_get_raw_report(struct hid_device *hid,
 636                                   u8 report_type, u8 report_id,
 637                                   u8 *buf, size_t count)
 638 {
 639         struct i2c_client *client = hid->driver_data;
 640         struct i2c_hid *ihid = i2c_get_clientdata(client);
 641         int ret_count;
 642
 643         if (report_type == HID_OUTPUT_REPORT)
 644                 return -EINVAL;
 645
 646         /*
 647          * In case of unnumbered reports the response from the device will
 648          * not have the report ID that the upper layers expect, so we need
 649          * to stash it the buffer ourselves and adjust the data size.
 650          */
 651         if (!report_id) {
 652                 buf[0] = 0;
 653                 buf++;
 654                 count--;
 655         }
 656
 657         ret_count = i2c_hid_get_report(ihid,
 658                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 659                         report_id, buf, count);
 660
 661         if (ret_count > 0 && !report_id)
 662                 ret_count++;
 663
 664         return ret_count;
 665 }
 666
 667 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
 668                                      const u8 *buf, size_t count, bool do_set)
 669 {
 670         struct i2c_client *client = hid->driver_data;
 671         struct i2c_hid *ihid = i2c_get_clientdata(client);
 672         int report_id = buf[0];
 673         int ret;
 674
 675         if (report_type == HID_INPUT_REPORT)
 676                 return -EINVAL;
 677
 678         mutex_lock(&ihid->reset_lock);
 679
 680         /*
 681          * Note that both numbered and unnumbered reports passed here
 682          * are supposed to have report ID stored in the 1st byte of the
 683          * buffer, so we strip it off unconditionally before passing payload
 684          * to i2c_hid_set_or_send_report which takes care of encoding
 685          * everything properly.
 686          */
 687         ret = i2c_hid_set_or_send_report(ihid,
 688                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 689                                 report_id, buf + 1, count - 1, do_set);
 690
 691         if (ret >= 0)
 692                 ret++; /* add report_id to the number of transferred bytes */
 693
 694         mutex_unlock(&ihid->reset_lock);
 695
 696         return ret;
 697 }
 698
 699 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
 700 {
 701         return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
 702                                          false);
 703 }
 704
 705 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 706                                __u8 *buf, size_t len, unsigned char rtype,
 707                                int reqtype)
 708 {
 709         switch (reqtype) {
 710         case HID_REQ_GET_REPORT:
 711                 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
 712         case HID_REQ_SET_REPORT:
 713                 if (buf[0] != reportnum)
 714                         return -EINVAL;
 715                 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
 716         default:
 717                 return -EIO;
 718         }
 719 }
 720
 721 static int i2c_hid_parse(struct hid_device *hid)
 722 {
 723         struct i2c_client *client = hid->driver_data;
 724         struct i2c_hid *ihid = i2c_get_clientdata(client);
 725         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 726         unsigned int rsize;
 727         char *rdesc;
 728         int ret;
 729         int tries = 3;
 730         char *use_override;
 731
 732         i2c_hid_dbg(ihid, "entering %s\n", __func__);
 733
 734         rsize = le16_to_cpu(hdesc->wReportDescLength);
 735         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 736                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 737                 return -EINVAL;
 738         }
 739
 740         do {
 741                 ret = i2c_hid_hwreset(ihid);
 742                 if (ret)
 743                         msleep(1000);
 744         } while (tries-- > 0 && ret);
 745
 746         if (ret)
 747                 return ret;
 748
 749         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 750                                                                 &rsize);
 751
 752         if (use_override) {
 753                 rdesc = use_override;
 754                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 755         } else {
 756                 rdesc = kzalloc(rsize, GFP_KERNEL);
 757
 758                 if (!rdesc) {
 759                         dbg_hid("couldn't allocate rdesc memory\n");
 760                         return -ENOMEM;
 761                 }
 762
 763                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 764
 765                 ret = i2c_hid_read_register(ihid,
 766                                             ihid->hdesc.wReportDescRegister,
 767                                             rdesc, rsize);
 768                 if (ret) {
 769                         hid_err(hid, "reading report descriptor failed\n");
 770                         kfree(rdesc);
 771                         return -EIO;
 772                 }
 773         }
 774
 775         i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
 776
 777         ret = hid_parse_report(hid, rdesc, rsize);
 778         if (!use_override)
 779                 kfree(rdesc);
 780
 781         if (ret) {
 782                 dbg_hid("parsing report descriptor failed\n");
 783                 return ret;
 784         }
 785
 786         return 0;
 787 }
 788
 789 static int i2c_hid_start(struct hid_device *hid)
 790 {
 791         struct i2c_client *client = hid->driver_data;
 792         struct i2c_hid *ihid = i2c_get_clientdata(client);
 793         int ret;
 794         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 795
 796         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 797         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 798         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 799
 800         if (bufsize > ihid->bufsize) {
 801                 disable_irq(client->irq);
 802                 i2c_hid_free_buffers(ihid);
 803
 804                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 805                 enable_irq(client->irq);
 806
 807                 if (ret)
 808                         return ret;
 809         }
 810
 811         return 0;
 812 }
 813
 814 static void i2c_hid_stop(struct hid_device *hid)
 815 {
 816         hid->claimed = 0;
 817 }
 818
 819 static int i2c_hid_open(struct hid_device *hid)
 820 {
 821         struct i2c_client *client = hid->driver_data;
 822         struct i2c_hid *ihid = i2c_get_clientdata(client);
 823
 824         set_bit(I2C_HID_STARTED, &ihid->flags);
 825         return 0;
 826 }
 827
 828 static void i2c_hid_close(struct hid_device *hid)
 829 {
 830         struct i2c_client *client = hid->driver_data;
 831         struct i2c_hid *ihid = i2c_get_clientdata(client);
 832
 833         clear_bit(I2C_HID_STARTED, &ihid->flags);
 834 }
 835
 836 static const struct hid_ll_driver i2c_hid_ll_driver = {
 837         .parse = i2c_hid_parse,
 838         .start = i2c_hid_start,
 839         .stop = i2c_hid_stop,
 840         .open = i2c_hid_open,
 841         .close = i2c_hid_close,
 842         .output_report = i2c_hid_output_report,
 843         .raw_request = i2c_hid_raw_request,
 844 };
 845
 846 static int i2c_hid_init_irq(struct i2c_client *client)
 847 {
 848         struct i2c_hid *ihid = i2c_get_clientdata(client);
 849         unsigned long irqflags = 0;
 850         int ret;
 851
 852         i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
 853
 854         if (!irq_get_trigger_type(client->irq))
 855                 irqflags = IRQF_TRIGGER_LOW;
 856
 857         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 858                                    irqflags | IRQF_ONESHOT, client->name, ihid);
 859         if (ret < 0) {
 860                 dev_warn(&client->dev,
 861                         "Could not register for %s interrupt, irq = %d,"
 862                         " ret = %d\n",
 863                         client->name, client->irq, ret);
 864
 865                 return ret;
 866         }
 867
 868         return 0;
 869 }
 870
 871 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
 872 {
 873         struct i2c_client *client = ihid->client;
 874         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 875         unsigned int dsize;
 876         int error;
 877
 878         /* i2c hid fetch using a fixed descriptor size (30 bytes) */
 879         if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
 880                 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
 881                 ihid->hdesc =
 882                         *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
 883         } else {
 884                 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
 885                 error = i2c_hid_read_register(ihid,
 886                                               ihid->wHIDDescRegister,
 887                                               &ihid->hdesc,
 888                                               sizeof(ihid->hdesc));
 889                 if (error) {
 890                         dev_err(&ihid->client->dev,
 891                                 "failed to fetch HID descriptor: %d\n",
 892                                 error);
 893                         return -ENODEV;
 894                 }
 895         }
 896
 897         /* Validate the length of HID descriptor, the 4 first bytes:
 898          * bytes 0-1 -> length
 899          * bytes 2-3 -> bcdVersion (has to be 1.00) */
 900         /* check bcdVersion == 1.0 */
 901         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
 902                 dev_err(&ihid->client->dev,
 903                         "unexpected HID descriptor bcdVersion (0x%04hx)\n",
 904                         le16_to_cpu(hdesc->bcdVersion));
 905                 return -ENODEV;
 906         }
 907
 908         /* Descriptor length should be 30 bytes as per the specification */
 909         dsize = le16_to_cpu(hdesc->wHIDDescLength);
 910         if (dsize != sizeof(struct i2c_hid_desc)) {
 911                 dev_err(&ihid->client->dev,
 912                         "weird size of HID descriptor (%u)\n", dsize);
 913                 return -ENODEV;
 914         }
 915         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
 916         return 0;
 917 }
 918
 919 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
 920 {
 921         if (!ihid->ops->power_up)
 922                 return 0;
 923
 924         return ihid->ops->power_up(ihid->ops);
 925 }
 926
 927 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
 928 {
 929         if (!ihid->ops->power_down)
 930                 return;
 931
 932         ihid->ops->power_down(ihid->ops);
 933 }
 934
 935 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 936 {
 937         if (!ihid->ops->shutdown_tail)
 938                 return;
 939
 940         ihid->ops->shutdown_tail(ihid->ops);
 941 }
 942
 943 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 944                        u16 hid_descriptor_address, u32 quirks)
 945 {
 946         int ret;
 947         struct i2c_hid *ihid;
 948         struct hid_device *hid;
 949
 950         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
 951
 952         if (!client->irq) {
 953                 dev_err(&client->dev,
 954                         "HID over i2c has not been provided an Int IRQ\n");
 955                 return -EINVAL;
 956         }
 957
 958         if (client->irq < 0) {
 959                 if (client->irq != -EPROBE_DEFER)
 960                         dev_err(&client->dev,
 961                                 "HID over i2c doesn't have a valid IRQ\n");
 962                 return client->irq;
 963         }
 964
 965         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
 966         if (!ihid)
 967                 return -ENOMEM;
 968
 969         ihid->ops = ops;
 970
 971         ret = i2c_hid_core_power_up(ihid);
 972         if (ret)
 973                 return ret;
 974
 975         i2c_set_clientdata(client, ihid);
 976
 977         ihid->client = client;
 978
 979         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 980
 981         init_waitqueue_head(&ihid->wait);
 982         mutex_init(&ihid->reset_lock);
 983
 984         /* we need to allocate the command buffer without knowing the maximum
 985          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 986          * real computation later. */
 987         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 988         if (ret < 0)
 989                 goto err_powered;
 990
 991         device_enable_async_suspend(&client->dev);
 992
 993         /* Make sure there is something at this address */
 994         ret = i2c_smbus_read_byte(client);
 995         if (ret < 0) {
 996                 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
 997                 ret = -ENXIO;
 998                 goto err_powered;
 999         }
1000
1001         ret = i2c_hid_fetch_hid_descriptor(ihid);
1002         if (ret < 0) {
1003                 dev_err(&client->dev,
1004                         "Failed to fetch the HID Descriptor\n");
1005                 goto err_powered;
1006         }
1007
1008         ret = i2c_hid_init_irq(client);
1009         if (ret < 0)
1010                 goto err_powered;
1011
1012         hid = hid_allocate_device();
1013         if (IS_ERR(hid)) {
1014                 ret = PTR_ERR(hid);
1015                 goto err_irq;
1016         }
1017
1018         ihid->hid = hid;
1019
1020         hid->driver_data = client;
1021         hid->ll_driver = &i2c_hid_ll_driver;
1022         hid->dev.parent = &client->dev;
1023         hid->bus = BUS_I2C;
1024         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1025         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1026         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1027
1028         hid->initial_quirks = quirks;
1029         hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1030                                                       hid->product);
1031
1032         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1033                  client->name, (u16)hid->vendor, (u16)hid->product);
1034         strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1035
1036         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1037
1038         ret = hid_add_device(hid);
1039         if (ret) {
1040                 if (ret != -ENODEV)
1041                         hid_err(client, "can't add hid device: %d\n", ret);
1042                 goto err_mem_free;
1043         }
1044
1045         return 0;
1046
1047 err_mem_free:
1048         hid_destroy_device(hid);
1049
1050 err_irq:
1051         free_irq(client->irq, ihid);
1052
1053 err_powered:
1054         i2c_hid_core_power_down(ihid);
1055         i2c_hid_free_buffers(ihid);
1056         return ret;
1057 }
1058 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1059
1060 void i2c_hid_core_remove(struct i2c_client *client)
1061 {
1062         struct i2c_hid *ihid = i2c_get_clientdata(client);
1063         struct hid_device *hid;
1064
1065         hid = ihid->hid;
1066         hid_destroy_device(hid);
1067
1068         free_irq(client->irq, ihid);
1069
1070         if (ihid->bufsize)
1071                 i2c_hid_free_buffers(ihid);
1072
1073         i2c_hid_core_power_down(ihid);
1074 }
1075 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1076
1077 void i2c_hid_core_shutdown(struct i2c_client *client)
1078 {
1079         struct i2c_hid *ihid = i2c_get_clientdata(client);
1080
1081         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1082         free_irq(client->irq, ihid);
1083
1084         i2c_hid_core_shutdown_tail(ihid);
1085 }
1086 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1087
1088 #ifdef CONFIG_PM_SLEEP
1089 static int i2c_hid_core_suspend(struct device *dev)
1090 {
1091         struct i2c_client *client = to_i2c_client(dev);
1092         struct i2c_hid *ihid = i2c_get_clientdata(client);
1093         struct hid_device *hid = ihid->hid;
1094         int ret;
1095
1096         ret = hid_driver_suspend(hid, PMSG_SUSPEND);
1097         if (ret < 0)
1098                 return ret;
1099
1100         /* Save some power */
1101         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1102
1103         disable_irq(client->irq);
1104
1105         if (!device_may_wakeup(&client->dev))
1106                 i2c_hid_core_power_down(ihid);
1107
1108         return 0;
1109 }
1110
1111 static int i2c_hid_core_resume(struct device *dev)
1112 {
1113         int ret;
1114         struct i2c_client *client = to_i2c_client(dev);
1115         struct i2c_hid *ihid = i2c_get_clientdata(client);
1116         struct hid_device *hid = ihid->hid;
1117
1118         if (!device_may_wakeup(&client->dev))
1119                 i2c_hid_core_power_up(ihid);
1120
1121         enable_irq(client->irq);
1122
1123         /* Instead of resetting device, simply powers the device on. This
1124          * solves "incomplete reports" on Raydium devices 2386:3118 and
1125          * 2386:4B33 and fixes various SIS touchscreens no longer sending
1126          * data after a suspend/resume.
1127          *
1128          * However some ALPS touchpads generate IRQ storm without reset, so
1129          * let's still reset them here.
1130          */
1131         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1132                 ret = i2c_hid_hwreset(ihid);
1133         else
1134                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1135
1136         if (ret)
1137                 return ret;
1138
1139         return hid_driver_reset_resume(hid);
1140 }
1141 #endif
1142
1143 const struct dev_pm_ops i2c_hid_core_pm = {
1144         SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1145 };
1146 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1147
1148 MODULE_DESCRIPTION("HID over I2C core driver");
1149 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1150 MODULE_LICENSE("GPL");