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 <drm/drm_panel.h>
  42
  43 #include "../hid-ids.h"
  44 #include "i2c-hid.h"
  45
  46 /* quirks to control the device */
  47 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET        BIT(0)
  48 #define I2C_HID_QUIRK_BOGUS_IRQ                 BIT(1)
  49 #define I2C_HID_QUIRK_RESET_ON_RESUME           BIT(2)
  50 #define I2C_HID_QUIRK_BAD_INPUT_SIZE            BIT(3)
  51 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET     BIT(4)
  52 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND       BIT(5)
  53
  54 /* Command opcodes */
  55 #define I2C_HID_OPCODE_RESET                    0x01
  56 #define I2C_HID_OPCODE_GET_REPORT               0x02
  57 #define I2C_HID_OPCODE_SET_REPORT               0x03
  58 #define I2C_HID_OPCODE_GET_IDLE                 0x04
  59 #define I2C_HID_OPCODE_SET_IDLE                 0x05
  60 #define I2C_HID_OPCODE_GET_PROTOCOL             0x06
  61 #define I2C_HID_OPCODE_SET_PROTOCOL             0x07
  62 #define I2C_HID_OPCODE_SET_POWER                0x08
  63
  64 /* flags */
  65 #define I2C_HID_STARTED         0
  66 #define I2C_HID_RESET_PENDING   1
  67
  68 #define I2C_HID_PWR_ON          0x00
  69 #define I2C_HID_PWR_SLEEP       0x01
  70
  71 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__)
  72
  73 struct i2c_hid_desc {
  74         __le16 wHIDDescLength;
  75         __le16 bcdVersion;
  76         __le16 wReportDescLength;
  77         __le16 wReportDescRegister;
  78         __le16 wInputRegister;
  79         __le16 wMaxInputLength;
  80         __le16 wOutputRegister;
  81         __le16 wMaxOutputLength;
  82         __le16 wCommandRegister;
  83         __le16 wDataRegister;
  84         __le16 wVendorID;
  85         __le16 wProductID;
  86         __le16 wVersionID;
  87         __le32 reserved;
  88 } __packed;
  89
  90 /* The main device structure */
  91 struct i2c_hid {
  92         struct i2c_client       *client;        /* i2c client */
  93         struct hid_device       *hid;   /* pointer to corresponding HID dev */
  94         struct i2c_hid_desc hdesc;              /* the HID Descriptor */
  95         __le16                  wHIDDescRegister; /* location of the i2c
  96                                                    * register of the HID
  97                                                    * descriptor. */
  98         unsigned int            bufsize;        /* i2c buffer size */
  99         u8                      *inbuf;         /* Input buffer */
 100         u8                      *rawbuf;        /* Raw Input buffer */
 101         u8                      *cmdbuf;        /* Command buffer */
 102
 103         unsigned long           flags;          /* device flags */
 104         unsigned long           quirks;         /* Various quirks */
 105
 106         wait_queue_head_t       wait;           /* For waiting the interrupt */
 107
 108         struct mutex            cmd_lock;       /* protects cmdbuf and rawbuf */
 109         struct mutex            reset_lock;
 110
 111         struct i2chid_ops       *ops;
 112         struct drm_panel_follower panel_follower;
 113         struct work_struct      panel_follower_prepare_work;
 114         bool                    is_panel_follower;
 115         bool                    prepare_work_finished;
 116 };
 117
 118 static const struct i2c_hid_quirks {
 119         __u16 idVendor;
 120         __u16 idProduct;
 121         __u32 quirks;
 122 } i2c_hid_quirks[] = {
 123         { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 124                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 125         { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
 126                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 127         { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
 128                 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
 129         { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
 130                  I2C_HID_QUIRK_RESET_ON_RESUME },
 131         { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
 132                  I2C_HID_QUIRK_RESET_ON_RESUME },
 133         { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 134                 I2C_HID_QUIRK_BAD_INPUT_SIZE },
 135         { I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063,
 136                 I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND },
 137         /*
 138          * Sending the wakeup after reset actually break ELAN touchscreen controller
 139          */
 140         { USB_VENDOR_ID_ELAN, HID_ANY_ID,
 141                  I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 142                  I2C_HID_QUIRK_BOGUS_IRQ },
 143         { 0, 0 }
 144 };
 145
 146 /*
 147  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
 148  * @idVendor: the 16-bit vendor ID
 149  * @idProduct: the 16-bit product ID
 150  *
 151  * Returns: a u32 quirks value.
 152  */
 153 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 154 {
 155         u32 quirks = 0;
 156         int n;
 157
 158         for (n = 0; i2c_hid_quirks[n].idVendor; n++)
 159                 if (i2c_hid_quirks[n].idVendor == idVendor &&
 160                     (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
 161                      i2c_hid_quirks[n].idProduct == idProduct))
 162                         quirks = i2c_hid_quirks[n].quirks;
 163
 164         return quirks;
 165 }
 166
 167 static int i2c_hid_probe_address(struct i2c_hid *ihid)
 168 {
 169         int ret;
 170
 171         /*
 172          * Some STM-based devices need 400µs after a rising clock edge to wake
 173          * from deep sleep, in which case the first read will fail. Try after a
 174          * short sleep to see if the device came alive on the bus. Certain
 175          * Weida Tech devices also need this.
 176          */
 177         ret = i2c_smbus_read_byte(ihid->client);
 178         if (ret < 0) {
 179                 usleep_range(400, 500);
 180                 ret = i2c_smbus_read_byte(ihid->client);
 181         }
 182         return ret < 0 ? ret : 0;
 183 }
 184
 185 static int i2c_hid_xfer(struct i2c_hid *ihid,
 186                         u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
 187 {
 188         struct i2c_client *client = ihid->client;
 189         struct i2c_msg msgs[2] = { 0 };
 190         int n = 0;
 191         int ret;
 192
 193         if (send_len) {
 194                 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
 195                             __func__, send_len, send_buf);
 196
 197                 msgs[n].addr = client->addr;
 198                 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
 199                 msgs[n].len = send_len;
 200                 msgs[n].buf = send_buf;
 201                 n++;
 202         }
 203
 204         if (recv_len) {
 205                 msgs[n].addr = client->addr;
 206                 msgs[n].flags = (client->flags & I2C_M_TEN) |
 207                                 I2C_M_RD | I2C_M_DMA_SAFE;
 208                 msgs[n].len = recv_len;
 209                 msgs[n].buf = recv_buf;
 210                 n++;
 211         }
 212
 213         ret = i2c_transfer(client->adapter, msgs, n);
 214
 215         if (ret != n)
 216                 return ret < 0 ? ret : -EIO;
 217
 218         return 0;
 219 }
 220
 221 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
 222                                  void *buf, size_t len)
 223 {
 224         guard(mutex)(&ihid->cmd_lock);
 225
 226         *(__le16 *)ihid->cmdbuf = reg;
 227
 228         return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
 229 }
 230
 231 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
 232                                      int report_type, int report_id)
 233 {
 234         size_t length = 0;
 235
 236         if (report_id < 0x0F) {
 237                 buf[length++] = report_type << 4 | report_id;
 238                 buf[length++] = opcode;
 239         } else {
 240                 buf[length++] = report_type << 4 | 0x0F;
 241                 buf[length++] = opcode;
 242                 buf[length++] = report_id;
 243         }
 244
 245         return length;
 246 }
 247
 248 static int i2c_hid_get_report(struct i2c_hid *ihid,
 249                               u8 report_type, u8 report_id,
 250                               u8 *recv_buf, size_t recv_len)
 251 {
 252         size_t length = 0;
 253         size_t ret_count;
 254         int error;
 255
 256         i2c_hid_dbg(ihid, "%s\n", __func__);
 257
 258         guard(mutex)(&ihid->cmd_lock);
 259
 260         /* Command register goes first */
 261         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 262         length += sizeof(__le16);
 263         /* Next is GET_REPORT command */
 264         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 265                                          I2C_HID_OPCODE_GET_REPORT,
 266                                          report_type, report_id);
 267         /*
 268          * Device will send report data through data register. Because
 269          * command can be either 2 or 3 bytes destination for the data
 270          * register may be not aligned.
 271          */
 272         put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
 273                            ihid->cmdbuf + length);
 274         length += sizeof(__le16);
 275
 276         /*
 277          * In addition to report data device will supply data length
 278          * in the first 2 bytes of the response, so adjust .
 279          */
 280         error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
 281                              ihid->rawbuf, recv_len + sizeof(__le16));
 282         if (error) {
 283                 dev_err(&ihid->client->dev,
 284                         "failed to set a report to device: %d\n", error);
 285                 return error;
 286         }
 287
 288         /* The buffer is sufficiently aligned */
 289         ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
 290
 291         /* Check for empty report response */
 292         if (ret_count <= sizeof(__le16))
 293                 return 0;
 294
 295         recv_len = min(recv_len, ret_count - sizeof(__le16));
 296         memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
 297
 298         if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
 299                 dev_err(&ihid->client->dev,
 300                         "device returned incorrect report (%d vs %d expected)\n",
 301                         recv_buf[0], report_id);
 302                 return -EINVAL;
 303         }
 304
 305         return recv_len;
 306 }
 307
 308 static size_t i2c_hid_format_report(u8 *buf, int report_id,
 309                                     const u8 *data, size_t size)
 310 {
 311         size_t length = sizeof(__le16); /* reserve space to store size */
 312
 313         if (report_id)
 314                 buf[length++] = report_id;
 315
 316         memcpy(buf + length, data, size);
 317         length += size;
 318
 319         /* Store overall size in the beginning of the buffer */
 320         put_unaligned_le16(length, buf);
 321
 322         return length;
 323 }
 324
 325 /**
 326  * i2c_hid_set_or_send_report: forward an incoming report to the device
 327  * @ihid: the i2c hid device
 328  * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 329  * @report_id: the report ID
 330  * @buf: the actual data to transfer, without the report ID
 331  * @data_len: size of buf
 332  * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
 333  */
 334 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
 335                                       u8 report_type, u8 report_id,
 336                                       const u8 *buf, size_t data_len,
 337                                       bool do_set)
 338 {
 339         size_t length = 0;
 340         int error;
 341
 342         i2c_hid_dbg(ihid, "%s\n", __func__);
 343
 344         if (data_len > ihid->bufsize)
 345                 return -EINVAL;
 346
 347         if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
 348                 return -ENOSYS;
 349
 350         guard(mutex)(&ihid->cmd_lock);
 351
 352         if (do_set) {
 353                 /* Command register goes first */
 354                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 355                 length += sizeof(__le16);
 356                 /* Next is SET_REPORT command */
 357                 length += i2c_hid_encode_command(ihid->cmdbuf + length,
 358                                                  I2C_HID_OPCODE_SET_REPORT,
 359                                                  report_type, report_id);
 360                 /*
 361                  * Report data will go into the data register. Because
 362                  * command can be either 2 or 3 bytes destination for
 363                  * the data register may be not aligned.
 364                 */
 365                 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
 366                                    ihid->cmdbuf + length);
 367                 length += sizeof(__le16);
 368         } else {
 369                 /*
 370                  * With simple "send report" all data goes into the output
 371                  * register.
 372                  */
 373                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
 374                 length += sizeof(__le16);
 375         }
 376
 377         length += i2c_hid_format_report(ihid->cmdbuf + length,
 378                                         report_id, buf, data_len);
 379
 380         error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 381         if (error) {
 382                 dev_err(&ihid->client->dev,
 383                         "failed to set a report to device: %d\n", error);
 384                 return error;
 385         }
 386
 387         return data_len;
 388 }
 389
 390 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
 391 {
 392         size_t length;
 393
 394         guard(mutex)(&ihid->cmd_lock);
 395
 396         /* SET_POWER uses command register */
 397         *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 398         length = sizeof(__le16);
 399
 400         /* Now the command itself */
 401         length += i2c_hid_encode_command(ihid->cmdbuf + length,
 402                                          I2C_HID_OPCODE_SET_POWER,
 403                                          0, power_state);
 404
 405         return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 406 }
 407
 408 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
 409 {
 410         int ret;
 411
 412         i2c_hid_dbg(ihid, "%s\n", __func__);
 413
 414         ret = i2c_hid_set_power_command(ihid, power_state);
 415         if (ret)
 416                 dev_err(&ihid->client->dev,
 417                         "failed to change power setting.\n");
 418
 419         /*
 420          * The HID over I2C specification states that if a DEVICE needs time
 421          * after the PWR_ON request, it should utilise CLOCK stretching.
 422          * However, it has been observered that the Windows driver provides a
 423          * 1ms sleep between the PWR_ON and RESET requests.
 424          * According to Goodix Windows even waits 60 ms after (other?)
 425          * PWR_ON requests. Testing has confirmed that several devices
 426          * will not work properly without a delay after a PWR_ON request.
 427          */
 428         if (!ret && power_state == I2C_HID_PWR_ON)
 429                 msleep(60);
 430
 431         return ret;
 432 }
 433
 434 static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
 435 {
 436         size_t length = 0;
 437         int ret;
 438
 439         i2c_hid_dbg(ihid, "%s\n", __func__);
 440
 441         /*
 442          * This prevents sending feature reports while the device is
 443          * being reset. Otherwise we may lose the reset complete
 444          * interrupt.
 445          */
 446         lockdep_assert_held(&ihid->reset_lock);
 447
 448         ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 449         if (ret)
 450                 return ret;
 451
 452         scoped_guard(mutex, &ihid->cmd_lock) {
 453                 /* Prepare reset command. Command register goes first. */
 454                 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 455                 length += sizeof(__le16);
 456                 /* Next is RESET command itself */
 457                 length += i2c_hid_encode_command(ihid->cmdbuf + length,
 458                                                  I2C_HID_OPCODE_RESET, 0, 0);
 459
 460                 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 461
 462                 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
 463                 if (ret) {
 464                         dev_err(&ihid->client->dev,
 465                                 "failed to reset device: %d\n", ret);
 466                         break;
 467                 }
 468
 469                 return 0;
 470         }
 471
 472         /* Clean up if sending reset command failed */
 473         clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 474         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 475         return ret;
 476 }
 477
 478 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
 479 {
 480         int ret = 0;
 481
 482         i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
 483
 484         if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
 485                 msleep(100);
 486                 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 487         } else if (!wait_event_timeout(ihid->wait,
 488                                        !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
 489                                        msecs_to_jiffies(1000))) {
 490                 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
 491                 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 492         }
 493         i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
 494
 495         /* At least some SIS devices need this after reset */
 496         if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
 497                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 498
 499         return ret;
 500 }
 501
 502 static void i2c_hid_get_input(struct i2c_hid *ihid)
 503 {
 504         u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 505         u16 ret_size;
 506         int ret;
 507
 508         if (size > ihid->bufsize)
 509                 size = ihid->bufsize;
 510
 511         ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
 512         if (ret != size) {
 513                 if (ret < 0)
 514                         return;
 515
 516                 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
 517                         __func__, ret, size);
 518                 return;
 519         }
 520
 521         /* Receiving buffer is properly aligned */
 522         ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
 523         if (!ret_size) {
 524                 /* host or device initiated RESET completed */
 525                 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
 526                         wake_up(&ihid->wait);
 527                 return;
 528         }
 529
 530         if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
 531                 dev_warn_once(&ihid->client->dev,
 532                               "%s: IRQ triggered but there's no data\n",
 533                               __func__);
 534                 return;
 535         }
 536
 537         if (ret_size > size || ret_size < sizeof(__le16)) {
 538                 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
 539                         *(__le16 *)ihid->inbuf = cpu_to_le16(size);
 540                         ret_size = size;
 541                 } else {
 542                         dev_err(&ihid->client->dev,
 543                                 "%s: incomplete report (%d/%d)\n",
 544                                 __func__, size, ret_size);
 545                         return;
 546                 }
 547         }
 548
 549         i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 550
 551         if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
 552                 if (ihid->hid->group != HID_GROUP_RMI)
 553                         pm_wakeup_event(&ihid->client->dev, 0);
 554
 555                 hid_input_report(ihid->hid, HID_INPUT_REPORT,
 556                                 ihid->inbuf + sizeof(__le16),
 557                                 ret_size - sizeof(__le16), 1);
 558         }
 559
 560         return;
 561 }
 562
 563 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
 564 {
 565         struct i2c_hid *ihid = dev_id;
 566
 567         i2c_hid_get_input(ihid);
 568
 569         return IRQ_HANDLED;
 570 }
 571
 572 static int i2c_hid_get_report_length(struct hid_report *report)
 573 {
 574         return ((report->size - 1) >> 3) + 1 +
 575                 report->device->report_enum[report->type].numbered + 2;
 576 }
 577
 578 /*
 579  * Traverse the supplied list of reports and find the longest
 580  */
 581 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
 582                 unsigned int *max)
 583 {
 584         struct hid_report *report;
 585         unsigned int size;
 586
 587         /* We should not rely on wMaxInputLength, as some devices may set it to
 588          * a wrong length. */
 589         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 590                 size = i2c_hid_get_report_length(report);
 591                 if (*max < size)
 592                         *max = size;
 593         }
 594 }
 595
 596 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
 597 {
 598         kfree(ihid->inbuf);
 599         kfree(ihid->rawbuf);
 600         kfree(ihid->cmdbuf);
 601         ihid->inbuf = NULL;
 602         ihid->rawbuf = NULL;
 603         ihid->cmdbuf = NULL;
 604         ihid->bufsize = 0;
 605 }
 606
 607 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 608 {
 609         /*
 610          * The worst case is computed from the set_report command with a
 611          * reportID > 15 and the maximum report length.
 612          */
 613         int cmd_len = sizeof(__le16) +  /* command register */
 614                       sizeof(u8) +      /* encoded report type/ID */
 615                       sizeof(u8) +      /* opcode */
 616                       sizeof(u8) +      /* optional 3rd byte report ID */
 617                       sizeof(__le16) +  /* data register */
 618                       sizeof(__le16) +  /* report data size */
 619                       sizeof(u8) +      /* report ID if numbered report */
 620                       report_size;
 621
 622         ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
 623         ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
 624         ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
 625
 626         if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
 627                 i2c_hid_free_buffers(ihid);
 628                 return -ENOMEM;
 629         }
 630
 631         ihid->bufsize = report_size;
 632
 633         return 0;
 634 }
 635
 636 static int i2c_hid_get_raw_report(struct hid_device *hid,
 637                                   u8 report_type, u8 report_id,
 638                                   u8 *buf, size_t count)
 639 {
 640         struct i2c_client *client = hid->driver_data;
 641         struct i2c_hid *ihid = i2c_get_clientdata(client);
 642         int ret_count;
 643
 644         if (report_type == HID_OUTPUT_REPORT)
 645                 return -EINVAL;
 646
 647         /*
 648          * In case of unnumbered reports the response from the device will
 649          * not have the report ID that the upper layers expect, so we need
 650          * to stash it the buffer ourselves and adjust the data size.
 651          */
 652         if (!report_id) {
 653                 buf[0] = 0;
 654                 buf++;
 655                 count--;
 656         }
 657
 658         ret_count = i2c_hid_get_report(ihid,
 659                         report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
 660                         report_id, buf, count);
 661
 662         if (ret_count > 0 && !report_id)
 663                 ret_count++;
 664
 665         return ret_count;
 666 }
 667
 668 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
 669                                      const u8 *buf, size_t count, bool do_set)
 670 {
 671         struct i2c_client *client = hid->driver_data;
 672         struct i2c_hid *ihid = i2c_get_clientdata(client);
 673         int report_id = buf[0];
 674         int ret;
 675
 676         if (report_type == HID_INPUT_REPORT)
 677                 return -EINVAL;
 678
 679         mutex_lock(&ihid->reset_lock);
 680
 681         /*
 682          * Note that both numbered and unnumbered reports passed here
 683          * are supposed to have report ID stored in the 1st byte of the
 684          * buffer, so we strip it off unconditionally before passing payload
 685          * to i2c_hid_set_or_send_report which takes care of encoding
 686          * everything properly.
 687          */
 688         ret = i2c_hid_set_or_send_report(ihid,
 689                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
 690                                 report_id, buf + 1, count - 1, do_set);
 691
 692         if (ret >= 0)
 693                 ret++; /* add report_id to the number of transferred bytes */
 694
 695         mutex_unlock(&ihid->reset_lock);
 696
 697         return ret;
 698 }
 699
 700 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
 701 {
 702         return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
 703                                          false);
 704 }
 705
 706 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 707                                __u8 *buf, size_t len, unsigned char rtype,
 708                                int reqtype)
 709 {
 710         switch (reqtype) {
 711         case HID_REQ_GET_REPORT:
 712                 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
 713         case HID_REQ_SET_REPORT:
 714                 if (buf[0] != reportnum)
 715                         return -EINVAL;
 716                 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
 717         default:
 718                 return -EIO;
 719         }
 720 }
 721
 722 static int i2c_hid_parse(struct hid_device *hid)
 723 {
 724         struct i2c_client *client = hid->driver_data;
 725         struct i2c_hid *ihid = i2c_get_clientdata(client);
 726         struct i2c_hid_desc *hdesc = &ihid->hdesc;
 727         char *rdesc = NULL, *use_override = NULL;
 728         unsigned int rsize;
 729         int ret;
 730         int tries = 3;
 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         mutex_lock(&ihid->reset_lock);
 741         do {
 742                 ret = i2c_hid_start_hwreset(ihid);
 743                 if (ret == 0)
 744                         ret = i2c_hid_finish_hwreset(ihid);
 745                 else
 746                         msleep(1000);
 747         } while (tries-- > 0 && ret);
 748         mutex_unlock(&ihid->reset_lock);
 749
 750         if (ret)
 751                 return ret;
 752
 753         use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
 754                                                                 &rsize);
 755
 756         if (use_override) {
 757                 rdesc = use_override;
 758                 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
 759         } else {
 760                 rdesc = kzalloc(rsize, GFP_KERNEL);
 761                 if (!rdesc)
 762                         return -ENOMEM;
 763
 764                 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
 765
 766                 ret = i2c_hid_read_register(ihid,
 767                                             ihid->hdesc.wReportDescRegister,
 768                                             rdesc, rsize);
 769                 if (ret) {
 770                         hid_err(hid, "reading report descriptor failed\n");
 771                         goto out;
 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 (ret)
 779                 dbg_hid("parsing report descriptor failed\n");
 780
 781 out:
 782         if (!use_override)
 783                 kfree(rdesc);
 784
 785         return ret;
 786 }
 787
 788 static int i2c_hid_start(struct hid_device *hid)
 789 {
 790         struct i2c_client *client = hid->driver_data;
 791         struct i2c_hid *ihid = i2c_get_clientdata(client);
 792         int ret;
 793         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 794
 795         i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 796         i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 797         i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 798
 799         if (bufsize > ihid->bufsize) {
 800                 disable_irq(client->irq);
 801                 i2c_hid_free_buffers(ihid);
 802
 803                 ret = i2c_hid_alloc_buffers(ihid, bufsize);
 804                 enable_irq(client->irq);
 805
 806                 if (ret)
 807                         return ret;
 808         }
 809
 810         return 0;
 811 }
 812
 813 static void i2c_hid_stop(struct hid_device *hid)
 814 {
 815         hid->claimed = 0;
 816 }
 817
 818 static int i2c_hid_open(struct hid_device *hid)
 819 {
 820         struct i2c_client *client = hid->driver_data;
 821         struct i2c_hid *ihid = i2c_get_clientdata(client);
 822
 823         set_bit(I2C_HID_STARTED, &ihid->flags);
 824         return 0;
 825 }
 826
 827 static void i2c_hid_close(struct hid_device *hid)
 828 {
 829         struct i2c_client *client = hid->driver_data;
 830         struct i2c_hid *ihid = i2c_get_clientdata(client);
 831
 832         clear_bit(I2C_HID_STARTED, &ihid->flags);
 833 }
 834
 835 static const struct hid_ll_driver i2c_hid_ll_driver = {
 836         .parse = i2c_hid_parse,
 837         .start = i2c_hid_start,
 838         .stop = i2c_hid_stop,
 839         .open = i2c_hid_open,
 840         .close = i2c_hid_close,
 841         .output_report = i2c_hid_output_report,
 842         .raw_request = i2c_hid_raw_request,
 843 };
 844
 845 static int i2c_hid_init_irq(struct i2c_client *client)
 846 {
 847         struct i2c_hid *ihid = i2c_get_clientdata(client);
 848         unsigned long irqflags = 0;
 849         int ret;
 850
 851         i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
 852
 853         if (!irq_get_trigger_type(client->irq))
 854                 irqflags = IRQF_TRIGGER_LOW;
 855
 856         ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
 857                                    irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
 858                                    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 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
 944 {
 945         struct i2c_client *client = ihid->client;
 946         struct hid_device *hid = ihid->hid;
 947         int ret;
 948
 949         ret = hid_driver_suspend(hid, PMSG_SUSPEND);
 950         if (ret < 0)
 951                 return ret;
 952
 953         /* Save some power */
 954         if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
 955                 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 956
 957         disable_irq(client->irq);
 958
 959         if (force_poweroff || !device_may_wakeup(&client->dev))
 960                 i2c_hid_core_power_down(ihid);
 961
 962         return 0;
 963 }
 964
 965 static int i2c_hid_core_resume(struct i2c_hid *ihid)
 966 {
 967         struct i2c_client *client = ihid->client;
 968         struct hid_device *hid = ihid->hid;
 969         int ret;
 970
 971         if (!device_may_wakeup(&client->dev))
 972                 i2c_hid_core_power_up(ihid);
 973
 974         enable_irq(client->irq);
 975
 976         /* Make sure the device is awake on the bus */
 977         ret = i2c_hid_probe_address(ihid);
 978         if (ret < 0) {
 979                 dev_err(&client->dev, "nothing at address after resume: %d\n",
 980                         ret);
 981                 return -ENXIO;
 982         }
 983
 984         /* Instead of resetting device, simply powers the device on. This
 985          * solves "incomplete reports" on Raydium devices 2386:3118 and
 986          * 2386:4B33 and fixes various SIS touchscreens no longer sending
 987          * data after a suspend/resume.
 988          *
 989          * However some ALPS touchpads generate IRQ storm without reset, so
 990          * let's still reset them here.
 991          */
 992         if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) {
 993                 mutex_lock(&ihid->reset_lock);
 994                 ret = i2c_hid_start_hwreset(ihid);
 995                 if (ret == 0)
 996                         ret = i2c_hid_finish_hwreset(ihid);
 997                 mutex_unlock(&ihid->reset_lock);
 998         } else {
 999                 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1000         }
1001
1002         if (ret)
1003                 return ret;
1004
1005         return hid_driver_reset_resume(hid);
1006 }
1007
1008 /*
1009  * Check that the device exists and parse the HID descriptor.
1010  */
1011 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1012 {
1013         struct i2c_client *client = ihid->client;
1014         struct hid_device *hid = ihid->hid;
1015         int ret;
1016
1017         ret = i2c_hid_probe_address(ihid);
1018         if (ret < 0) {
1019                 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1020                 return -ENXIO;
1021         }
1022
1023         ret = i2c_hid_fetch_hid_descriptor(ihid);
1024         if (ret < 0) {
1025                 dev_err(&client->dev,
1026                         "Failed to fetch the HID Descriptor\n");
1027                 return ret;
1028         }
1029
1030         hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1031         hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1032         hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1033
1034         hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1035                                                       hid->product);
1036
1037         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1038                  client->name, (u16)hid->vendor, (u16)hid->product);
1039         strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1040
1041         ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1042
1043         return 0;
1044 }
1045
1046 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1047 {
1048         struct i2c_client *client = ihid->client;
1049         struct hid_device *hid = ihid->hid;
1050         int ret;
1051
1052         enable_irq(client->irq);
1053
1054         ret = hid_add_device(hid);
1055         if (ret) {
1056                 if (ret != -ENODEV)
1057                         hid_err(client, "can't add hid device: %d\n", ret);
1058                 disable_irq(client->irq);
1059                 return ret;
1060         }
1061
1062         return 0;
1063 }
1064
1065 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1066 {
1067         int ret;
1068
1069         ret = i2c_hid_core_power_up(ihid);
1070         if (ret)
1071                 return ret;
1072
1073         ret = __i2c_hid_core_probe(ihid);
1074         if (ret)
1075                 goto err_power_down;
1076
1077         ret = i2c_hid_core_register_hid(ihid);
1078         if (ret)
1079                 goto err_power_down;
1080
1081         return 0;
1082
1083 err_power_down:
1084         i2c_hid_core_power_down(ihid);
1085
1086         return ret;
1087 }
1088
1089 static void ihid_core_panel_prepare_work(struct work_struct *work)
1090 {
1091         struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1092                                             panel_follower_prepare_work);
1093         struct hid_device *hid = ihid->hid;
1094         int ret;
1095
1096         /*
1097          * hid->version is set on the first power up. If it's still zero then
1098          * this is the first power on so we should perform initial power up
1099          * steps.
1100          */
1101         if (!hid->version)
1102                 ret = i2c_hid_core_probe_panel_follower(ihid);
1103         else
1104                 ret = i2c_hid_core_resume(ihid);
1105
1106         if (ret)
1107                 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1108         else
1109                 WRITE_ONCE(ihid->prepare_work_finished, true);
1110
1111         /*
1112          * The work APIs provide a number of memory ordering guarantees
1113          * including one that says that memory writes before schedule_work()
1114          * are always visible to the work function, but they don't appear to
1115          * guarantee that a write that happened in the work is visible after
1116          * cancel_work_sync(). We'll add a write memory barrier here to match
1117          * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1118          * prepare_work_finished is visible there.
1119          */
1120         smp_wmb();
1121 }
1122
1123 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
1124 {
1125         struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1126
1127         /*
1128          * Powering on a touchscreen can be a slow process. Queue the work to
1129          * the system workqueue so we don't block the panel's power up.
1130          */
1131         WRITE_ONCE(ihid->prepare_work_finished, false);
1132         schedule_work(&ihid->panel_follower_prepare_work);
1133
1134         return 0;
1135 }
1136
1137 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
1138 {
1139         struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1140
1141         cancel_work_sync(&ihid->panel_follower_prepare_work);
1142
1143         /* Match with ihid_core_panel_prepare_work() */
1144         smp_rmb();
1145         if (!READ_ONCE(ihid->prepare_work_finished))
1146                 return 0;
1147
1148         return i2c_hid_core_suspend(ihid, true);
1149 }
1150
1151 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
1152         .panel_prepared = i2c_hid_core_panel_prepared,
1153         .panel_unpreparing = i2c_hid_core_panel_unpreparing,
1154 };
1155
1156 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1157 {
1158         struct device *dev = &ihid->client->dev;
1159         int ret;
1160
1161         ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
1162
1163         /*
1164          * If we're not in control of our own power up/power down then we can't
1165          * do the logic to manage wakeups. Give a warning if a user thought
1166          * that was possible then force the capability off.
1167          */
1168         if (device_can_wakeup(dev)) {
1169                 dev_warn(dev, "Can't wakeup if following panel\n");
1170                 device_set_wakeup_capable(dev, false);
1171         }
1172
1173         ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1174         if (ret)
1175                 return ret;
1176
1177         return 0;
1178 }
1179
1180 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1181                        u16 hid_descriptor_address, u32 quirks)
1182 {
1183         int ret;
1184         struct i2c_hid *ihid;
1185         struct hid_device *hid;
1186
1187         dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1188
1189         if (!client->irq) {
1190                 dev_err(&client->dev,
1191                         "HID over i2c has not been provided an Int IRQ\n");
1192                 return -EINVAL;
1193         }
1194
1195         if (client->irq < 0) {
1196                 if (client->irq != -EPROBE_DEFER)
1197                         dev_err(&client->dev,
1198                                 "HID over i2c doesn't have a valid IRQ\n");
1199                 return client->irq;
1200         }
1201
1202         ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1203         if (!ihid)
1204                 return -ENOMEM;
1205
1206         i2c_set_clientdata(client, ihid);
1207
1208         ihid->ops = ops;
1209         ihid->client = client;
1210         ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1211         ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1212
1213         init_waitqueue_head(&ihid->wait);
1214         mutex_init(&ihid->cmd_lock);
1215         mutex_init(&ihid->reset_lock);
1216         INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
1217
1218         /* we need to allocate the command buffer without knowing the maximum
1219          * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1220          * real computation later. */
1221         ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1222         if (ret < 0)
1223                 return ret;
1224         device_enable_async_suspend(&client->dev);
1225
1226         hid = hid_allocate_device();
1227         if (IS_ERR(hid)) {
1228                 ret = PTR_ERR(hid);
1229                 goto err_free_buffers;
1230         }
1231
1232         ihid->hid = hid;
1233
1234         hid->driver_data = client;
1235         hid->ll_driver = &i2c_hid_ll_driver;
1236         hid->dev.parent = &client->dev;
1237         hid->bus = BUS_I2C;
1238         hid->initial_quirks = quirks;
1239
1240         /* Power on and probe unless device is a panel follower. */
1241         if (!ihid->is_panel_follower) {
1242                 ret = i2c_hid_core_power_up(ihid);
1243                 if (ret < 0)
1244                         goto err_destroy_device;
1245
1246                 ret = __i2c_hid_core_probe(ihid);
1247                 if (ret < 0)
1248                         goto err_power_down;
1249         }
1250
1251         ret = i2c_hid_init_irq(client);
1252         if (ret < 0)
1253                 goto err_power_down;
1254
1255         /*
1256          * If we're a panel follower, we'll register when the panel turns on;
1257          * otherwise we do it right away.
1258          */
1259         if (ihid->is_panel_follower)
1260                 ret = i2c_hid_core_register_panel_follower(ihid);
1261         else
1262                 ret = i2c_hid_core_register_hid(ihid);
1263         if (ret)
1264                 goto err_free_irq;
1265
1266         return 0;
1267
1268 err_free_irq:
1269         free_irq(client->irq, ihid);
1270 err_power_down:
1271         if (!ihid->is_panel_follower)
1272                 i2c_hid_core_power_down(ihid);
1273 err_destroy_device:
1274         hid_destroy_device(hid);
1275 err_free_buffers:
1276         i2c_hid_free_buffers(ihid);
1277
1278         return ret;
1279 }
1280 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1281
1282 void i2c_hid_core_remove(struct i2c_client *client)
1283 {
1284         struct i2c_hid *ihid = i2c_get_clientdata(client);
1285         struct hid_device *hid;
1286
1287         /*
1288          * If we're a follower, the act of unfollowing will cause us to be
1289          * powered down. Otherwise we need to manually do it.
1290          */
1291         if (ihid->is_panel_follower)
1292                 drm_panel_remove_follower(&ihid->panel_follower);
1293         else
1294                 i2c_hid_core_suspend(ihid, true);
1295
1296         hid = ihid->hid;
1297         hid_destroy_device(hid);
1298
1299         free_irq(client->irq, ihid);
1300
1301         if (ihid->bufsize)
1302                 i2c_hid_free_buffers(ihid);
1303 }
1304 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1305
1306 void i2c_hid_core_shutdown(struct i2c_client *client)
1307 {
1308         struct i2c_hid *ihid = i2c_get_clientdata(client);
1309
1310         i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1311         free_irq(client->irq, ihid);
1312
1313         i2c_hid_core_shutdown_tail(ihid);
1314 }
1315 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1316
1317 static int i2c_hid_core_pm_suspend(struct device *dev)
1318 {
1319         struct i2c_client *client = to_i2c_client(dev);
1320         struct i2c_hid *ihid = i2c_get_clientdata(client);
1321
1322         if (ihid->is_panel_follower)
1323                 return 0;
1324
1325         return i2c_hid_core_suspend(ihid, false);
1326 }
1327
1328 static int i2c_hid_core_pm_resume(struct device *dev)
1329 {
1330         struct i2c_client *client = to_i2c_client(dev);
1331         struct i2c_hid *ihid = i2c_get_clientdata(client);
1332
1333         if (ihid->is_panel_follower)
1334                 return 0;
1335
1336         return i2c_hid_core_resume(ihid);
1337 }
1338
1339 const struct dev_pm_ops i2c_hid_core_pm = {
1340         SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
1341 };
1342 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1343
1344 MODULE_DESCRIPTION("HID over I2C core driver");
1345 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1346 MODULE_LICENSE("GPL");