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_runtime.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 <linux/acpi.h> 40 #include <linux/of.h> 41 #include <linux/regulator/consumer.h> 42 43 #include <linux/platform_data/i2c-hid.h> 44 45 #include "../hid-ids.h" 46 #include "i2c-hid.h" 47 48 /* quirks to control the device */ 49 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0) 50 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1) 51 #define I2C_HID_QUIRK_NO_RUNTIME_PM BIT(2) 52 #define I2C_HID_QUIRK_DELAY_AFTER_SLEEP BIT(3) 53 54 /* flags */ 55 #define I2C_HID_STARTED 0 56 #define I2C_HID_RESET_PENDING 1 57 #define I2C_HID_READ_PENDING 2 58 59 #define I2C_HID_PWR_ON 0x00 60 #define I2C_HID_PWR_SLEEP 0x01 61 62 /* debug option */ 63 static bool debug; 64 module_param(debug, bool, 0444); 65 MODULE_PARM_DESC(debug, "print a lot of debug information"); 66 67 #define i2c_hid_dbg(ihid, fmt, arg...) \ 68 do { \ 69 if (debug) \ 70 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \ 71 } while (0) 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 struct i2c_hid_cmd { 91 unsigned int registerIndex; 92 __u8 opcode; 93 unsigned int length; 94 bool wait; 95 }; 96 97 union command { 98 u8 data[0]; 99 struct cmd { 100 __le16 reg; 101 __u8 reportTypeID; 102 __u8 opcode; 103 } __packed c; 104 }; 105 106 #define I2C_HID_CMD(opcode_) \ 107 .opcode = opcode_, .length = 4, \ 108 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister) 109 110 /* fetch HID descriptor */ 111 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 }; 112 /* fetch report descriptors */ 113 static const struct i2c_hid_cmd hid_report_descr_cmd = { 114 .registerIndex = offsetof(struct i2c_hid_desc, 115 wReportDescRegister), 116 .opcode = 0x00, 117 .length = 2 }; 118 /* commands */ 119 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01), 120 .wait = true }; 121 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) }; 122 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) }; 123 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) }; 124 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 }; 125 126 /* 127 * These definitions are not used here, but are defined by the spec. 128 * Keeping them here for documentation purposes. 129 * 130 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) }; 131 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) }; 132 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) }; 133 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) }; 134 */ 135 136 /* The main device structure */ 137 struct i2c_hid { 138 struct i2c_client *client; /* i2c client */ 139 struct hid_device *hid; /* pointer to corresponding HID dev */ 140 union { 141 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)]; 142 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 143 }; 144 __le16 wHIDDescRegister; /* location of the i2c 145 * register of the HID 146 * descriptor. */ 147 unsigned int bufsize; /* i2c buffer size */ 148 u8 *inbuf; /* Input buffer */ 149 u8 *rawbuf; /* Raw Input buffer */ 150 u8 *cmdbuf; /* Command buffer */ 151 u8 *argsbuf; /* Command arguments buffer */ 152 153 unsigned long flags; /* device flags */ 154 unsigned long quirks; /* Various quirks */ 155 156 wait_queue_head_t wait; /* For waiting the interrupt */ 157 158 struct i2c_hid_platform_data pdata; 159 160 bool irq_wake_enabled; 161 struct mutex reset_lock; 162 163 unsigned long sleep_delay; 164 }; 165 166 static const struct i2c_hid_quirks { 167 __u16 idVendor; 168 __u16 idProduct; 169 __u32 quirks; 170 } i2c_hid_quirks[] = { 171 { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752, 172 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, 173 { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755, 174 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, 175 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 176 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET | 177 I2C_HID_QUIRK_NO_RUNTIME_PM }, 178 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_4B33, 179 I2C_HID_QUIRK_DELAY_AFTER_SLEEP }, 180 { USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001, 181 I2C_HID_QUIRK_NO_RUNTIME_PM }, 182 { 0, 0 } 183 }; 184 185 /* 186 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device 187 * @idVendor: the 16-bit vendor ID 188 * @idProduct: the 16-bit product ID 189 * 190 * Returns: a u32 quirks value. 191 */ 192 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) 193 { 194 u32 quirks = 0; 195 int n; 196 197 for (n = 0; i2c_hid_quirks[n].idVendor; n++) 198 if (i2c_hid_quirks[n].idVendor == idVendor && 199 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || 200 i2c_hid_quirks[n].idProduct == idProduct)) 201 quirks = i2c_hid_quirks[n].quirks; 202 203 return quirks; 204 } 205 206 static int __i2c_hid_command(struct i2c_client *client, 207 const struct i2c_hid_cmd *command, u8 reportID, 208 u8 reportType, u8 *args, int args_len, 209 unsigned char *buf_recv, int data_len) 210 { 211 struct i2c_hid *ihid = i2c_get_clientdata(client); 212 union command *cmd = (union command *)ihid->cmdbuf; 213 int ret; 214 struct i2c_msg msg[2]; 215 int msg_num = 1; 216 217 int length = command->length; 218 bool wait = command->wait; 219 unsigned int registerIndex = command->registerIndex; 220 221 /* special case for hid_descr_cmd */ 222 if (command == &hid_descr_cmd) { 223 cmd->c.reg = ihid->wHIDDescRegister; 224 } else { 225 cmd->data[0] = ihid->hdesc_buffer[registerIndex]; 226 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1]; 227 } 228 229 if (length > 2) { 230 cmd->c.opcode = command->opcode; 231 cmd->c.reportTypeID = reportID | reportType << 4; 232 } 233 234 memcpy(cmd->data + length, args, args_len); 235 length += args_len; 236 237 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data); 238 239 msg[0].addr = client->addr; 240 msg[0].flags = client->flags & I2C_M_TEN; 241 msg[0].len = length; 242 msg[0].buf = cmd->data; 243 if (data_len > 0) { 244 msg[1].addr = client->addr; 245 msg[1].flags = client->flags & I2C_M_TEN; 246 msg[1].flags |= I2C_M_RD; 247 msg[1].len = data_len; 248 msg[1].buf = buf_recv; 249 msg_num = 2; 250 set_bit(I2C_HID_READ_PENDING, &ihid->flags); 251 } 252 253 if (wait) 254 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 255 256 ret = i2c_transfer(client->adapter, msg, msg_num); 257 258 if (data_len > 0) 259 clear_bit(I2C_HID_READ_PENDING, &ihid->flags); 260 261 if (ret != msg_num) 262 return ret < 0 ? ret : -EIO; 263 264 ret = 0; 265 266 if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) { 267 msleep(100); 268 } else if (wait) { 269 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 270 if (!wait_event_timeout(ihid->wait, 271 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 272 msecs_to_jiffies(5000))) 273 ret = -ENODATA; 274 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 275 } 276 277 return ret; 278 } 279 280 static int i2c_hid_command(struct i2c_client *client, 281 const struct i2c_hid_cmd *command, 282 unsigned char *buf_recv, int data_len) 283 { 284 return __i2c_hid_command(client, command, 0, 0, NULL, 0, 285 buf_recv, data_len); 286 } 287 288 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType, 289 u8 reportID, unsigned char *buf_recv, int data_len) 290 { 291 struct i2c_hid *ihid = i2c_get_clientdata(client); 292 u8 args[3]; 293 int ret; 294 int args_len = 0; 295 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister); 296 297 i2c_hid_dbg(ihid, "%s\n", __func__); 298 299 if (reportID >= 0x0F) { 300 args[args_len++] = reportID; 301 reportID = 0x0F; 302 } 303 304 args[args_len++] = readRegister & 0xFF; 305 args[args_len++] = readRegister >> 8; 306 307 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID, 308 reportType, args, args_len, buf_recv, data_len); 309 if (ret) { 310 dev_err(&client->dev, 311 "failed to retrieve report from device.\n"); 312 return ret; 313 } 314 315 return 0; 316 } 317 318 /** 319 * i2c_hid_set_or_send_report: forward an incoming report to the device 320 * @client: the i2c_client of the device 321 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 322 * @reportID: the report ID 323 * @buf: the actual data to transfer, without the report ID 324 * @len: size of buf 325 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report 326 */ 327 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType, 328 u8 reportID, unsigned char *buf, size_t data_len, bool use_data) 329 { 330 struct i2c_hid *ihid = i2c_get_clientdata(client); 331 u8 *args = ihid->argsbuf; 332 const struct i2c_hid_cmd *hidcmd; 333 int ret; 334 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister); 335 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister); 336 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength); 337 u16 size; 338 int args_len; 339 int index = 0; 340 341 i2c_hid_dbg(ihid, "%s\n", __func__); 342 343 if (data_len > ihid->bufsize) 344 return -EINVAL; 345 346 size = 2 /* size */ + 347 (reportID ? 1 : 0) /* reportID */ + 348 data_len /* buf */; 349 args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ + 350 2 /* dataRegister */ + 351 size /* args */; 352 353 if (!use_data && maxOutputLength == 0) 354 return -ENOSYS; 355 356 if (reportID >= 0x0F) { 357 args[index++] = reportID; 358 reportID = 0x0F; 359 } 360 361 /* 362 * use the data register for feature reports or if the device does not 363 * support the output register 364 */ 365 if (use_data) { 366 args[index++] = dataRegister & 0xFF; 367 args[index++] = dataRegister >> 8; 368 hidcmd = &hid_set_report_cmd; 369 } else { 370 args[index++] = outputRegister & 0xFF; 371 args[index++] = outputRegister >> 8; 372 hidcmd = &hid_no_cmd; 373 } 374 375 args[index++] = size & 0xFF; 376 args[index++] = size >> 8; 377 378 if (reportID) 379 args[index++] = reportID; 380 381 memcpy(&args[index], buf, data_len); 382 383 ret = __i2c_hid_command(client, hidcmd, reportID, 384 reportType, args, args_len, NULL, 0); 385 if (ret) { 386 dev_err(&client->dev, "failed to set a report to device.\n"); 387 return ret; 388 } 389 390 return data_len; 391 } 392 393 static int i2c_hid_set_power(struct i2c_client *client, int power_state) 394 { 395 struct i2c_hid *ihid = i2c_get_clientdata(client); 396 int ret; 397 unsigned long now, delay; 398 399 i2c_hid_dbg(ihid, "%s\n", __func__); 400 401 /* 402 * Some devices require to send a command to wakeup before power on. 403 * The call will get a return value (EREMOTEIO) but device will be 404 * triggered and activated. After that, it goes like a normal device. 405 */ 406 if (power_state == I2C_HID_PWR_ON && 407 ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) { 408 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0); 409 410 /* Device was already activated */ 411 if (!ret) 412 goto set_pwr_exit; 413 } 414 415 if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP && 416 power_state == I2C_HID_PWR_ON) { 417 now = jiffies; 418 if (time_after(ihid->sleep_delay, now)) { 419 delay = jiffies_to_usecs(ihid->sleep_delay - now); 420 usleep_range(delay, delay + 1); 421 } 422 } 423 424 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state, 425 0, NULL, 0, NULL, 0); 426 427 if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP && 428 power_state == I2C_HID_PWR_SLEEP) 429 ihid->sleep_delay = jiffies + msecs_to_jiffies(20); 430 431 if (ret) 432 dev_err(&client->dev, "failed to change power setting.\n"); 433 434 set_pwr_exit: 435 return ret; 436 } 437 438 static int i2c_hid_hwreset(struct i2c_client *client) 439 { 440 struct i2c_hid *ihid = i2c_get_clientdata(client); 441 int ret; 442 443 i2c_hid_dbg(ihid, "%s\n", __func__); 444 445 /* 446 * This prevents sending feature reports while the device is 447 * being reset. Otherwise we may lose the reset complete 448 * interrupt. 449 */ 450 mutex_lock(&ihid->reset_lock); 451 452 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 453 if (ret) 454 goto out_unlock; 455 456 /* 457 * The HID over I2C specification states that if a DEVICE needs time 458 * after the PWR_ON request, it should utilise CLOCK stretching. 459 * However, it has been observered that the Windows driver provides a 460 * 1ms sleep between the PWR_ON and RESET requests and that some devices 461 * rely on this. 462 */ 463 usleep_range(1000, 5000); 464 465 i2c_hid_dbg(ihid, "resetting...\n"); 466 467 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0); 468 if (ret) { 469 dev_err(&client->dev, "failed to reset device.\n"); 470 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 471 } 472 473 out_unlock: 474 mutex_unlock(&ihid->reset_lock); 475 return ret; 476 } 477 478 static void i2c_hid_get_input(struct i2c_hid *ihid) 479 { 480 int ret; 481 u32 ret_size; 482 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 483 484 if (size > ihid->bufsize) 485 size = ihid->bufsize; 486 487 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 488 if (ret != size) { 489 if (ret < 0) 490 return; 491 492 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 493 __func__, ret, size); 494 return; 495 } 496 497 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8; 498 499 if (!ret_size) { 500 /* host or device initiated RESET completed */ 501 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 502 wake_up(&ihid->wait); 503 return; 504 } 505 506 if ((ret_size > size) || (ret_size < 2)) { 507 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n", 508 __func__, size, ret_size); 509 return; 510 } 511 512 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 513 514 if (test_bit(I2C_HID_STARTED, &ihid->flags)) 515 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2, 516 ret_size - 2, 1); 517 518 return; 519 } 520 521 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 522 { 523 struct i2c_hid *ihid = dev_id; 524 525 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) 526 return IRQ_HANDLED; 527 528 i2c_hid_get_input(ihid); 529 530 return IRQ_HANDLED; 531 } 532 533 static int i2c_hid_get_report_length(struct hid_report *report) 534 { 535 return ((report->size - 1) >> 3) + 1 + 536 report->device->report_enum[report->type].numbered + 2; 537 } 538 539 /* 540 * Traverse the supplied list of reports and find the longest 541 */ 542 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 543 unsigned int *max) 544 { 545 struct hid_report *report; 546 unsigned int size; 547 548 /* We should not rely on wMaxInputLength, as some devices may set it to 549 * a wrong length. */ 550 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 551 size = i2c_hid_get_report_length(report); 552 if (*max < size) 553 *max = size; 554 } 555 } 556 557 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 558 { 559 kfree(ihid->inbuf); 560 kfree(ihid->rawbuf); 561 kfree(ihid->argsbuf); 562 kfree(ihid->cmdbuf); 563 ihid->inbuf = NULL; 564 ihid->rawbuf = NULL; 565 ihid->cmdbuf = NULL; 566 ihid->argsbuf = NULL; 567 ihid->bufsize = 0; 568 } 569 570 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 571 { 572 /* the worst case is computed from the set_report command with a 573 * reportID > 15 and the maximum report length */ 574 int args_len = sizeof(__u8) + /* ReportID */ 575 sizeof(__u8) + /* optional ReportID byte */ 576 sizeof(__u16) + /* data register */ 577 sizeof(__u16) + /* size of the report */ 578 report_size; /* report */ 579 580 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 581 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 582 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL); 583 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL); 584 585 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) { 586 i2c_hid_free_buffers(ihid); 587 return -ENOMEM; 588 } 589 590 ihid->bufsize = report_size; 591 592 return 0; 593 } 594 595 static int i2c_hid_get_raw_report(struct hid_device *hid, 596 unsigned char report_number, __u8 *buf, size_t count, 597 unsigned char report_type) 598 { 599 struct i2c_client *client = hid->driver_data; 600 struct i2c_hid *ihid = i2c_get_clientdata(client); 601 size_t ret_count, ask_count; 602 int ret; 603 604 if (report_type == HID_OUTPUT_REPORT) 605 return -EINVAL; 606 607 /* +2 bytes to include the size of the reply in the query buffer */ 608 ask_count = min(count + 2, (size_t)ihid->bufsize); 609 610 ret = i2c_hid_get_report(client, 611 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 612 report_number, ihid->rawbuf, ask_count); 613 614 if (ret < 0) 615 return ret; 616 617 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8); 618 619 if (ret_count <= 2) 620 return 0; 621 622 ret_count = min(ret_count, ask_count); 623 624 /* The query buffer contains the size, dropping it in the reply */ 625 count = min(count, ret_count - 2); 626 memcpy(buf, ihid->rawbuf + 2, count); 627 628 return count; 629 } 630 631 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, 632 size_t count, unsigned char report_type, bool use_data) 633 { 634 struct i2c_client *client = hid->driver_data; 635 struct i2c_hid *ihid = i2c_get_clientdata(client); 636 int report_id = buf[0]; 637 int ret; 638 639 if (report_type == HID_INPUT_REPORT) 640 return -EINVAL; 641 642 mutex_lock(&ihid->reset_lock); 643 644 if (report_id) { 645 buf++; 646 count--; 647 } 648 649 ret = i2c_hid_set_or_send_report(client, 650 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 651 report_id, buf, count, use_data); 652 653 if (report_id && ret >= 0) 654 ret++; /* add report_id to the number of transfered bytes */ 655 656 mutex_unlock(&ihid->reset_lock); 657 658 return ret; 659 } 660 661 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf, 662 size_t count) 663 { 664 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT, 665 false); 666 } 667 668 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 669 __u8 *buf, size_t len, unsigned char rtype, 670 int reqtype) 671 { 672 switch (reqtype) { 673 case HID_REQ_GET_REPORT: 674 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype); 675 case HID_REQ_SET_REPORT: 676 if (buf[0] != reportnum) 677 return -EINVAL; 678 return i2c_hid_output_raw_report(hid, buf, len, rtype, true); 679 default: 680 return -EIO; 681 } 682 } 683 684 static int i2c_hid_parse(struct hid_device *hid) 685 { 686 struct i2c_client *client = hid->driver_data; 687 struct i2c_hid *ihid = i2c_get_clientdata(client); 688 struct i2c_hid_desc *hdesc = &ihid->hdesc; 689 unsigned int rsize; 690 char *rdesc; 691 int ret; 692 int tries = 3; 693 char *use_override; 694 695 i2c_hid_dbg(ihid, "entering %s\n", __func__); 696 697 rsize = le16_to_cpu(hdesc->wReportDescLength); 698 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 699 dbg_hid("weird size of report descriptor (%u)\n", rsize); 700 return -EINVAL; 701 } 702 703 do { 704 ret = i2c_hid_hwreset(client); 705 if (ret) 706 msleep(1000); 707 } while (tries-- > 0 && ret); 708 709 if (ret) 710 return ret; 711 712 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 713 &rsize); 714 715 if (use_override) { 716 rdesc = use_override; 717 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 718 } else { 719 rdesc = kzalloc(rsize, GFP_KERNEL); 720 721 if (!rdesc) { 722 dbg_hid("couldn't allocate rdesc memory\n"); 723 return -ENOMEM; 724 } 725 726 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 727 728 ret = i2c_hid_command(client, &hid_report_descr_cmd, 729 rdesc, rsize); 730 if (ret) { 731 hid_err(hid, "reading report descriptor failed\n"); 732 kfree(rdesc); 733 return -EIO; 734 } 735 } 736 737 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 738 739 ret = hid_parse_report(hid, rdesc, rsize); 740 if (!use_override) 741 kfree(rdesc); 742 743 if (ret) { 744 dbg_hid("parsing report descriptor failed\n"); 745 return ret; 746 } 747 748 return 0; 749 } 750 751 static int i2c_hid_start(struct hid_device *hid) 752 { 753 struct i2c_client *client = hid->driver_data; 754 struct i2c_hid *ihid = i2c_get_clientdata(client); 755 int ret; 756 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 757 758 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 759 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 760 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 761 762 if (bufsize > ihid->bufsize) { 763 disable_irq(client->irq); 764 i2c_hid_free_buffers(ihid); 765 766 ret = i2c_hid_alloc_buffers(ihid, bufsize); 767 enable_irq(client->irq); 768 769 if (ret) 770 return ret; 771 } 772 773 return 0; 774 } 775 776 static void i2c_hid_stop(struct hid_device *hid) 777 { 778 hid->claimed = 0; 779 } 780 781 static int i2c_hid_open(struct hid_device *hid) 782 { 783 struct i2c_client *client = hid->driver_data; 784 struct i2c_hid *ihid = i2c_get_clientdata(client); 785 int ret = 0; 786 787 ret = pm_runtime_get_sync(&client->dev); 788 if (ret < 0) 789 return ret; 790 791 set_bit(I2C_HID_STARTED, &ihid->flags); 792 return 0; 793 } 794 795 static void i2c_hid_close(struct hid_device *hid) 796 { 797 struct i2c_client *client = hid->driver_data; 798 struct i2c_hid *ihid = i2c_get_clientdata(client); 799 800 clear_bit(I2C_HID_STARTED, &ihid->flags); 801 802 /* Save some power */ 803 pm_runtime_put(&client->dev); 804 } 805 806 static int i2c_hid_power(struct hid_device *hid, int lvl) 807 { 808 struct i2c_client *client = hid->driver_data; 809 struct i2c_hid *ihid = i2c_get_clientdata(client); 810 811 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl); 812 813 switch (lvl) { 814 case PM_HINT_FULLON: 815 pm_runtime_get_sync(&client->dev); 816 break; 817 case PM_HINT_NORMAL: 818 pm_runtime_put(&client->dev); 819 break; 820 } 821 return 0; 822 } 823 824 struct hid_ll_driver i2c_hid_ll_driver = { 825 .parse = i2c_hid_parse, 826 .start = i2c_hid_start, 827 .stop = i2c_hid_stop, 828 .open = i2c_hid_open, 829 .close = i2c_hid_close, 830 .power = i2c_hid_power, 831 .output_report = i2c_hid_output_report, 832 .raw_request = i2c_hid_raw_request, 833 }; 834 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); 835 836 static int i2c_hid_init_irq(struct i2c_client *client) 837 { 838 struct i2c_hid *ihid = i2c_get_clientdata(client); 839 unsigned long irqflags = 0; 840 int ret; 841 842 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); 843 844 if (!irq_get_trigger_type(client->irq)) 845 irqflags = IRQF_TRIGGER_LOW; 846 847 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 848 irqflags | IRQF_ONESHOT, client->name, ihid); 849 if (ret < 0) { 850 dev_warn(&client->dev, 851 "Could not register for %s interrupt, irq = %d," 852 " ret = %d\n", 853 client->name, client->irq, ret); 854 855 return ret; 856 } 857 858 return 0; 859 } 860 861 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 862 { 863 struct i2c_client *client = ihid->client; 864 struct i2c_hid_desc *hdesc = &ihid->hdesc; 865 unsigned int dsize; 866 int ret; 867 868 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 869 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 870 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 871 ihid->hdesc = 872 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 873 } else { 874 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 875 ret = i2c_hid_command(client, &hid_descr_cmd, 876 ihid->hdesc_buffer, 877 sizeof(struct i2c_hid_desc)); 878 if (ret) { 879 dev_err(&client->dev, "hid_descr_cmd failed\n"); 880 return -ENODEV; 881 } 882 } 883 884 /* Validate the length of HID descriptor, the 4 first bytes: 885 * bytes 0-1 -> length 886 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 887 /* check bcdVersion == 1.0 */ 888 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 889 dev_err(&client->dev, 890 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 891 le16_to_cpu(hdesc->bcdVersion)); 892 return -ENODEV; 893 } 894 895 /* Descriptor length should be 30 bytes as per the specification */ 896 dsize = le16_to_cpu(hdesc->wHIDDescLength); 897 if (dsize != sizeof(struct i2c_hid_desc)) { 898 dev_err(&client->dev, "weird size of HID descriptor (%u)\n", 899 dsize); 900 return -ENODEV; 901 } 902 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); 903 return 0; 904 } 905 906 #ifdef CONFIG_ACPI 907 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { 908 /* 909 * The CHPN0001 ACPI device, which is used to describe the Chipone 910 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. 911 */ 912 {"CHPN0001", 0 }, 913 { }, 914 }; 915 916 static int i2c_hid_acpi_pdata(struct i2c_client *client, 917 struct i2c_hid_platform_data *pdata) 918 { 919 static guid_t i2c_hid_guid = 920 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 921 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); 922 union acpi_object *obj; 923 struct acpi_device *adev; 924 acpi_handle handle; 925 926 handle = ACPI_HANDLE(&client->dev); 927 if (!handle || acpi_bus_get_device(handle, &adev)) { 928 dev_err(&client->dev, "Error could not get ACPI device\n"); 929 return -ENODEV; 930 } 931 932 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 933 return -ENODEV; 934 935 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 936 ACPI_TYPE_INTEGER); 937 if (!obj) { 938 dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n"); 939 return -ENODEV; 940 } 941 942 pdata->hid_descriptor_address = obj->integer.value; 943 ACPI_FREE(obj); 944 945 return 0; 946 } 947 948 static void i2c_hid_acpi_fix_up_power(struct device *dev) 949 { 950 struct acpi_device *adev; 951 952 adev = ACPI_COMPANION(dev); 953 if (adev) 954 acpi_device_fix_up_power(adev); 955 } 956 957 static const struct acpi_device_id i2c_hid_acpi_match[] = { 958 {"ACPI0C50", 0 }, 959 {"PNP0C50", 0 }, 960 { }, 961 }; 962 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 963 #else 964 static inline int i2c_hid_acpi_pdata(struct i2c_client *client, 965 struct i2c_hid_platform_data *pdata) 966 { 967 return -ENODEV; 968 } 969 970 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} 971 #endif 972 973 #ifdef CONFIG_OF 974 static int i2c_hid_of_probe(struct i2c_client *client, 975 struct i2c_hid_platform_data *pdata) 976 { 977 struct device *dev = &client->dev; 978 u32 val; 979 int ret; 980 981 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); 982 if (ret) { 983 dev_err(&client->dev, "HID register address not provided\n"); 984 return -ENODEV; 985 } 986 if (val >> 16) { 987 dev_err(&client->dev, "Bad HID register address: 0x%08x\n", 988 val); 989 return -EINVAL; 990 } 991 pdata->hid_descriptor_address = val; 992 993 return 0; 994 } 995 996 static const struct of_device_id i2c_hid_of_match[] = { 997 { .compatible = "hid-over-i2c" }, 998 {}, 999 }; 1000 MODULE_DEVICE_TABLE(of, i2c_hid_of_match); 1001 #else 1002 static inline int i2c_hid_of_probe(struct i2c_client *client, 1003 struct i2c_hid_platform_data *pdata) 1004 { 1005 return -ENODEV; 1006 } 1007 #endif 1008 1009 static void i2c_hid_fwnode_probe(struct i2c_client *client, 1010 struct i2c_hid_platform_data *pdata) 1011 { 1012 u32 val; 1013 1014 if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms", 1015 &val)) 1016 pdata->post_power_delay_ms = val; 1017 } 1018 1019 static int i2c_hid_probe(struct i2c_client *client, 1020 const struct i2c_device_id *dev_id) 1021 { 1022 int ret; 1023 struct i2c_hid *ihid; 1024 struct hid_device *hid; 1025 __u16 hidRegister; 1026 struct i2c_hid_platform_data *platform_data = client->dev.platform_data; 1027 1028 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 1029 1030 if (!client->irq) { 1031 dev_err(&client->dev, 1032 "HID over i2c has not been provided an Int IRQ\n"); 1033 return -EINVAL; 1034 } 1035 1036 if (client->irq < 0) { 1037 if (client->irq != -EPROBE_DEFER) 1038 dev_err(&client->dev, 1039 "HID over i2c doesn't have a valid IRQ\n"); 1040 return client->irq; 1041 } 1042 1043 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1044 if (!ihid) 1045 return -ENOMEM; 1046 1047 if (client->dev.of_node) { 1048 ret = i2c_hid_of_probe(client, &ihid->pdata); 1049 if (ret) 1050 return ret; 1051 } else if (!platform_data) { 1052 ret = i2c_hid_acpi_pdata(client, &ihid->pdata); 1053 if (ret) 1054 return ret; 1055 } else { 1056 ihid->pdata = *platform_data; 1057 } 1058 1059 /* Parse platform agnostic common properties from ACPI / device tree */ 1060 i2c_hid_fwnode_probe(client, &ihid->pdata); 1061 1062 ihid->pdata.supplies[0].supply = "vdd"; 1063 ihid->pdata.supplies[1].supply = "vddl"; 1064 1065 ret = devm_regulator_bulk_get(&client->dev, 1066 ARRAY_SIZE(ihid->pdata.supplies), 1067 ihid->pdata.supplies); 1068 if (ret) 1069 return ret; 1070 1071 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1072 ihid->pdata.supplies); 1073 if (ret < 0) 1074 return ret; 1075 1076 if (ihid->pdata.post_power_delay_ms) 1077 msleep(ihid->pdata.post_power_delay_ms); 1078 1079 i2c_set_clientdata(client, ihid); 1080 1081 ihid->client = client; 1082 1083 hidRegister = ihid->pdata.hid_descriptor_address; 1084 ihid->wHIDDescRegister = cpu_to_le16(hidRegister); 1085 1086 init_waitqueue_head(&ihid->wait); 1087 mutex_init(&ihid->reset_lock); 1088 1089 /* we need to allocate the command buffer without knowing the maximum 1090 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1091 * real computation later. */ 1092 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1093 if (ret < 0) 1094 goto err_regulator; 1095 1096 i2c_hid_acpi_fix_up_power(&client->dev); 1097 1098 pm_runtime_get_noresume(&client->dev); 1099 pm_runtime_set_active(&client->dev); 1100 pm_runtime_enable(&client->dev); 1101 device_enable_async_suspend(&client->dev); 1102 1103 /* Make sure there is something at this address */ 1104 ret = i2c_smbus_read_byte(client); 1105 if (ret < 0) { 1106 dev_dbg(&client->dev, "nothing at this address: %d\n", ret); 1107 ret = -ENXIO; 1108 goto err_pm; 1109 } 1110 1111 ret = i2c_hid_fetch_hid_descriptor(ihid); 1112 if (ret < 0) 1113 goto err_pm; 1114 1115 ret = i2c_hid_init_irq(client); 1116 if (ret < 0) 1117 goto err_pm; 1118 1119 hid = hid_allocate_device(); 1120 if (IS_ERR(hid)) { 1121 ret = PTR_ERR(hid); 1122 goto err_irq; 1123 } 1124 1125 ihid->hid = hid; 1126 1127 hid->driver_data = client; 1128 hid->ll_driver = &i2c_hid_ll_driver; 1129 hid->dev.parent = &client->dev; 1130 hid->bus = BUS_I2C; 1131 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1132 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1133 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1134 1135 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX", 1136 client->name, hid->vendor, hid->product); 1137 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1138 1139 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1140 1141 ret = hid_add_device(hid); 1142 if (ret) { 1143 if (ret != -ENODEV) 1144 hid_err(client, "can't add hid device: %d\n", ret); 1145 goto err_mem_free; 1146 } 1147 1148 if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM)) 1149 pm_runtime_put(&client->dev); 1150 1151 return 0; 1152 1153 err_mem_free: 1154 hid_destroy_device(hid); 1155 1156 err_irq: 1157 free_irq(client->irq, ihid); 1158 1159 err_pm: 1160 pm_runtime_put_noidle(&client->dev); 1161 pm_runtime_disable(&client->dev); 1162 1163 err_regulator: 1164 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1165 ihid->pdata.supplies); 1166 i2c_hid_free_buffers(ihid); 1167 return ret; 1168 } 1169 1170 static int i2c_hid_remove(struct i2c_client *client) 1171 { 1172 struct i2c_hid *ihid = i2c_get_clientdata(client); 1173 struct hid_device *hid; 1174 1175 if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM)) 1176 pm_runtime_get_sync(&client->dev); 1177 pm_runtime_disable(&client->dev); 1178 pm_runtime_set_suspended(&client->dev); 1179 pm_runtime_put_noidle(&client->dev); 1180 1181 hid = ihid->hid; 1182 hid_destroy_device(hid); 1183 1184 free_irq(client->irq, ihid); 1185 1186 if (ihid->bufsize) 1187 i2c_hid_free_buffers(ihid); 1188 1189 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1190 ihid->pdata.supplies); 1191 1192 return 0; 1193 } 1194 1195 static void i2c_hid_shutdown(struct i2c_client *client) 1196 { 1197 struct i2c_hid *ihid = i2c_get_clientdata(client); 1198 1199 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1200 free_irq(client->irq, ihid); 1201 } 1202 1203 #ifdef CONFIG_PM_SLEEP 1204 static int i2c_hid_suspend(struct device *dev) 1205 { 1206 struct i2c_client *client = to_i2c_client(dev); 1207 struct i2c_hid *ihid = i2c_get_clientdata(client); 1208 struct hid_device *hid = ihid->hid; 1209 int ret; 1210 int wake_status; 1211 1212 if (hid->driver && hid->driver->suspend) { 1213 /* 1214 * Wake up the device so that IO issues in 1215 * HID driver's suspend code can succeed. 1216 */ 1217 ret = pm_runtime_resume(dev); 1218 if (ret < 0) 1219 return ret; 1220 1221 ret = hid->driver->suspend(hid, PMSG_SUSPEND); 1222 if (ret < 0) 1223 return ret; 1224 } 1225 1226 if (!pm_runtime_suspended(dev)) { 1227 /* Save some power */ 1228 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1229 1230 disable_irq(client->irq); 1231 } 1232 1233 if (device_may_wakeup(&client->dev)) { 1234 wake_status = enable_irq_wake(client->irq); 1235 if (!wake_status) 1236 ihid->irq_wake_enabled = true; 1237 else 1238 hid_warn(hid, "Failed to enable irq wake: %d\n", 1239 wake_status); 1240 } else { 1241 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1242 ihid->pdata.supplies); 1243 } 1244 1245 return 0; 1246 } 1247 1248 static int i2c_hid_resume(struct device *dev) 1249 { 1250 int ret; 1251 struct i2c_client *client = to_i2c_client(dev); 1252 struct i2c_hid *ihid = i2c_get_clientdata(client); 1253 struct hid_device *hid = ihid->hid; 1254 int wake_status; 1255 1256 if (!device_may_wakeup(&client->dev)) { 1257 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1258 ihid->pdata.supplies); 1259 if (ret) 1260 hid_warn(hid, "Failed to enable supplies: %d\n", ret); 1261 1262 if (ihid->pdata.post_power_delay_ms) 1263 msleep(ihid->pdata.post_power_delay_ms); 1264 } else if (ihid->irq_wake_enabled) { 1265 wake_status = disable_irq_wake(client->irq); 1266 if (!wake_status) 1267 ihid->irq_wake_enabled = false; 1268 else 1269 hid_warn(hid, "Failed to disable irq wake: %d\n", 1270 wake_status); 1271 } 1272 1273 /* We'll resume to full power */ 1274 pm_runtime_disable(dev); 1275 pm_runtime_set_active(dev); 1276 pm_runtime_enable(dev); 1277 1278 enable_irq(client->irq); 1279 1280 /* Instead of resetting device, simply powers the device on. This 1281 * solves "incomplete reports" on Raydium devices 2386:3118 and 1282 * 2386:4B33 and fixes various SIS touchscreens no longer sending 1283 * data after a suspend/resume. 1284 */ 1285 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 1286 if (ret) 1287 return ret; 1288 1289 if (hid->driver && hid->driver->reset_resume) { 1290 ret = hid->driver->reset_resume(hid); 1291 return ret; 1292 } 1293 1294 return 0; 1295 } 1296 #endif 1297 1298 #ifdef CONFIG_PM 1299 static int i2c_hid_runtime_suspend(struct device *dev) 1300 { 1301 struct i2c_client *client = to_i2c_client(dev); 1302 1303 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1304 disable_irq(client->irq); 1305 return 0; 1306 } 1307 1308 static int i2c_hid_runtime_resume(struct device *dev) 1309 { 1310 struct i2c_client *client = to_i2c_client(dev); 1311 1312 enable_irq(client->irq); 1313 i2c_hid_set_power(client, I2C_HID_PWR_ON); 1314 return 0; 1315 } 1316 #endif 1317 1318 static const struct dev_pm_ops i2c_hid_pm = { 1319 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume) 1320 SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume, 1321 NULL) 1322 }; 1323 1324 static const struct i2c_device_id i2c_hid_id_table[] = { 1325 { "hid", 0 }, 1326 { "hid-over-i2c", 0 }, 1327 { }, 1328 }; 1329 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); 1330 1331 1332 static struct i2c_driver i2c_hid_driver = { 1333 .driver = { 1334 .name = "i2c_hid", 1335 .pm = &i2c_hid_pm, 1336 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), 1337 .of_match_table = of_match_ptr(i2c_hid_of_match), 1338 }, 1339 1340 .probe = i2c_hid_probe, 1341 .remove = i2c_hid_remove, 1342 .shutdown = i2c_hid_shutdown, 1343 .id_table = i2c_hid_id_table, 1344 }; 1345 1346 module_i2c_driver(i2c_hid_driver); 1347 1348 MODULE_DESCRIPTION("HID over I2C core driver"); 1349 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1350 MODULE_LICENSE("GPL"); 1351