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/device.h> 30 #include <linux/wait.h> 31 #include <linux/err.h> 32 #include <linux/string.h> 33 #include <linux/list.h> 34 #include <linux/jiffies.h> 35 #include <linux/kernel.h> 36 #include <linux/hid.h> 37 #include <linux/mutex.h> 38 #include <linux/acpi.h> 39 #include <linux/of.h> 40 #include <linux/regulator/consumer.h> 41 42 #include <linux/platform_data/i2c-hid.h> 43 44 #include "../hid-ids.h" 45 #include "i2c-hid.h" 46 47 /* quirks to control the device */ 48 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0) 49 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1) 50 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(4) 51 52 /* flags */ 53 #define I2C_HID_STARTED 0 54 #define I2C_HID_RESET_PENDING 1 55 #define I2C_HID_READ_PENDING 2 56 57 #define I2C_HID_PWR_ON 0x00 58 #define I2C_HID_PWR_SLEEP 0x01 59 60 /* debug option */ 61 static bool debug; 62 module_param(debug, bool, 0444); 63 MODULE_PARM_DESC(debug, "print a lot of debug information"); 64 65 #define i2c_hid_dbg(ihid, fmt, arg...) \ 66 do { \ 67 if (debug) \ 68 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \ 69 } while (0) 70 71 struct i2c_hid_desc { 72 __le16 wHIDDescLength; 73 __le16 bcdVersion; 74 __le16 wReportDescLength; 75 __le16 wReportDescRegister; 76 __le16 wInputRegister; 77 __le16 wMaxInputLength; 78 __le16 wOutputRegister; 79 __le16 wMaxOutputLength; 80 __le16 wCommandRegister; 81 __le16 wDataRegister; 82 __le16 wVendorID; 83 __le16 wProductID; 84 __le16 wVersionID; 85 __le32 reserved; 86 } __packed; 87 88 struct i2c_hid_cmd { 89 unsigned int registerIndex; 90 __u8 opcode; 91 unsigned int length; 92 bool wait; 93 }; 94 95 union command { 96 u8 data[0]; 97 struct cmd { 98 __le16 reg; 99 __u8 reportTypeID; 100 __u8 opcode; 101 } __packed c; 102 }; 103 104 #define I2C_HID_CMD(opcode_) \ 105 .opcode = opcode_, .length = 4, \ 106 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister) 107 108 /* fetch HID descriptor */ 109 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 }; 110 /* fetch report descriptors */ 111 static const struct i2c_hid_cmd hid_report_descr_cmd = { 112 .registerIndex = offsetof(struct i2c_hid_desc, 113 wReportDescRegister), 114 .opcode = 0x00, 115 .length = 2 }; 116 /* commands */ 117 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01), 118 .wait = true }; 119 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) }; 120 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) }; 121 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) }; 122 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 }; 123 124 /* 125 * These definitions are not used here, but are defined by the spec. 126 * Keeping them here for documentation purposes. 127 * 128 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) }; 129 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) }; 130 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) }; 131 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) }; 132 */ 133 134 /* The main device structure */ 135 struct i2c_hid { 136 struct i2c_client *client; /* i2c client */ 137 struct hid_device *hid; /* pointer to corresponding HID dev */ 138 union { 139 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)]; 140 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 141 }; 142 __le16 wHIDDescRegister; /* location of the i2c 143 * register of the HID 144 * descriptor. */ 145 unsigned int bufsize; /* i2c buffer size */ 146 u8 *inbuf; /* Input buffer */ 147 u8 *rawbuf; /* Raw Input buffer */ 148 u8 *cmdbuf; /* Command buffer */ 149 u8 *argsbuf; /* Command arguments buffer */ 150 151 unsigned long flags; /* device flags */ 152 unsigned long quirks; /* Various quirks */ 153 154 wait_queue_head_t wait; /* For waiting the interrupt */ 155 156 struct i2c_hid_platform_data pdata; 157 158 bool irq_wake_enabled; 159 struct mutex reset_lock; 160 161 unsigned long sleep_delay; 162 }; 163 164 static const struct i2c_hid_quirks { 165 __u16 idVendor; 166 __u16 idProduct; 167 __u32 quirks; 168 } i2c_hid_quirks[] = { 169 { USB_VENDOR_ID_WEIDA, HID_ANY_ID, 170 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, 171 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 172 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 173 { USB_VENDOR_ID_ELAN, HID_ANY_ID, 174 I2C_HID_QUIRK_BOGUS_IRQ }, 175 { 0, 0 } 176 }; 177 178 /* 179 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device 180 * @idVendor: the 16-bit vendor ID 181 * @idProduct: the 16-bit product ID 182 * 183 * Returns: a u32 quirks value. 184 */ 185 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) 186 { 187 u32 quirks = 0; 188 int n; 189 190 for (n = 0; i2c_hid_quirks[n].idVendor; n++) 191 if (i2c_hid_quirks[n].idVendor == idVendor && 192 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || 193 i2c_hid_quirks[n].idProduct == idProduct)) 194 quirks = i2c_hid_quirks[n].quirks; 195 196 return quirks; 197 } 198 199 static int __i2c_hid_command(struct i2c_client *client, 200 const struct i2c_hid_cmd *command, u8 reportID, 201 u8 reportType, u8 *args, int args_len, 202 unsigned char *buf_recv, int data_len) 203 { 204 struct i2c_hid *ihid = i2c_get_clientdata(client); 205 union command *cmd = (union command *)ihid->cmdbuf; 206 int ret; 207 struct i2c_msg msg[2]; 208 int msg_num = 1; 209 210 int length = command->length; 211 bool wait = command->wait; 212 unsigned int registerIndex = command->registerIndex; 213 214 /* special case for hid_descr_cmd */ 215 if (command == &hid_descr_cmd) { 216 cmd->c.reg = ihid->wHIDDescRegister; 217 } else { 218 cmd->data[0] = ihid->hdesc_buffer[registerIndex]; 219 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1]; 220 } 221 222 if (length > 2) { 223 cmd->c.opcode = command->opcode; 224 cmd->c.reportTypeID = reportID | reportType << 4; 225 } 226 227 memcpy(cmd->data + length, args, args_len); 228 length += args_len; 229 230 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data); 231 232 msg[0].addr = client->addr; 233 msg[0].flags = client->flags & I2C_M_TEN; 234 msg[0].len = length; 235 msg[0].buf = cmd->data; 236 if (data_len > 0) { 237 msg[1].addr = client->addr; 238 msg[1].flags = client->flags & I2C_M_TEN; 239 msg[1].flags |= I2C_M_RD; 240 msg[1].len = data_len; 241 msg[1].buf = buf_recv; 242 msg_num = 2; 243 set_bit(I2C_HID_READ_PENDING, &ihid->flags); 244 } 245 246 if (wait) 247 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 248 249 ret = i2c_transfer(client->adapter, msg, msg_num); 250 251 if (data_len > 0) 252 clear_bit(I2C_HID_READ_PENDING, &ihid->flags); 253 254 if (ret != msg_num) 255 return ret < 0 ? ret : -EIO; 256 257 ret = 0; 258 259 if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) { 260 msleep(100); 261 } else if (wait) { 262 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 263 if (!wait_event_timeout(ihid->wait, 264 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 265 msecs_to_jiffies(5000))) 266 ret = -ENODATA; 267 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 268 } 269 270 return ret; 271 } 272 273 static int i2c_hid_command(struct i2c_client *client, 274 const struct i2c_hid_cmd *command, 275 unsigned char *buf_recv, int data_len) 276 { 277 return __i2c_hid_command(client, command, 0, 0, NULL, 0, 278 buf_recv, data_len); 279 } 280 281 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType, 282 u8 reportID, unsigned char *buf_recv, int data_len) 283 { 284 struct i2c_hid *ihid = i2c_get_clientdata(client); 285 u8 args[3]; 286 int ret; 287 int args_len = 0; 288 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister); 289 290 i2c_hid_dbg(ihid, "%s\n", __func__); 291 292 if (reportID >= 0x0F) { 293 args[args_len++] = reportID; 294 reportID = 0x0F; 295 } 296 297 args[args_len++] = readRegister & 0xFF; 298 args[args_len++] = readRegister >> 8; 299 300 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID, 301 reportType, args, args_len, buf_recv, data_len); 302 if (ret) { 303 dev_err(&client->dev, 304 "failed to retrieve report from device.\n"); 305 return ret; 306 } 307 308 return 0; 309 } 310 311 /** 312 * i2c_hid_set_or_send_report: forward an incoming report to the device 313 * @client: the i2c_client of the device 314 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 315 * @reportID: the report ID 316 * @buf: the actual data to transfer, without the report ID 317 * @len: size of buf 318 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report 319 */ 320 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType, 321 u8 reportID, unsigned char *buf, size_t data_len, bool use_data) 322 { 323 struct i2c_hid *ihid = i2c_get_clientdata(client); 324 u8 *args = ihid->argsbuf; 325 const struct i2c_hid_cmd *hidcmd; 326 int ret; 327 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister); 328 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister); 329 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength); 330 u16 size; 331 int args_len; 332 int index = 0; 333 334 i2c_hid_dbg(ihid, "%s\n", __func__); 335 336 if (data_len > ihid->bufsize) 337 return -EINVAL; 338 339 size = 2 /* size */ + 340 (reportID ? 1 : 0) /* reportID */ + 341 data_len /* buf */; 342 args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ + 343 2 /* dataRegister */ + 344 size /* args */; 345 346 if (!use_data && maxOutputLength == 0) 347 return -ENOSYS; 348 349 if (reportID >= 0x0F) { 350 args[index++] = reportID; 351 reportID = 0x0F; 352 } 353 354 /* 355 * use the data register for feature reports or if the device does not 356 * support the output register 357 */ 358 if (use_data) { 359 args[index++] = dataRegister & 0xFF; 360 args[index++] = dataRegister >> 8; 361 hidcmd = &hid_set_report_cmd; 362 } else { 363 args[index++] = outputRegister & 0xFF; 364 args[index++] = outputRegister >> 8; 365 hidcmd = &hid_no_cmd; 366 } 367 368 args[index++] = size & 0xFF; 369 args[index++] = size >> 8; 370 371 if (reportID) 372 args[index++] = reportID; 373 374 memcpy(&args[index], buf, data_len); 375 376 ret = __i2c_hid_command(client, hidcmd, reportID, 377 reportType, args, args_len, NULL, 0); 378 if (ret) { 379 dev_err(&client->dev, "failed to set a report to device.\n"); 380 return ret; 381 } 382 383 return data_len; 384 } 385 386 static int i2c_hid_set_power(struct i2c_client *client, int power_state) 387 { 388 struct i2c_hid *ihid = i2c_get_clientdata(client); 389 int ret; 390 391 i2c_hid_dbg(ihid, "%s\n", __func__); 392 393 /* 394 * Some devices require to send a command to wakeup before power on. 395 * The call will get a return value (EREMOTEIO) but device will be 396 * triggered and activated. After that, it goes like a normal device. 397 */ 398 if (power_state == I2C_HID_PWR_ON && 399 ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) { 400 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0); 401 402 /* Device was already activated */ 403 if (!ret) 404 goto set_pwr_exit; 405 } 406 407 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state, 408 0, NULL, 0, NULL, 0); 409 410 if (ret) 411 dev_err(&client->dev, "failed to change power setting.\n"); 412 413 set_pwr_exit: 414 return ret; 415 } 416 417 static int i2c_hid_hwreset(struct i2c_client *client) 418 { 419 struct i2c_hid *ihid = i2c_get_clientdata(client); 420 int ret; 421 422 i2c_hid_dbg(ihid, "%s\n", __func__); 423 424 /* 425 * This prevents sending feature reports while the device is 426 * being reset. Otherwise we may lose the reset complete 427 * interrupt. 428 */ 429 mutex_lock(&ihid->reset_lock); 430 431 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 432 if (ret) 433 goto out_unlock; 434 435 /* 436 * The HID over I2C specification states that if a DEVICE needs time 437 * after the PWR_ON request, it should utilise CLOCK stretching. 438 * However, it has been observered that the Windows driver provides a 439 * 1ms sleep between the PWR_ON and RESET requests and that some devices 440 * rely on this. 441 */ 442 usleep_range(1000, 5000); 443 444 i2c_hid_dbg(ihid, "resetting...\n"); 445 446 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0); 447 if (ret) { 448 dev_err(&client->dev, "failed to reset device.\n"); 449 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 450 } 451 452 out_unlock: 453 mutex_unlock(&ihid->reset_lock); 454 return ret; 455 } 456 457 static void i2c_hid_get_input(struct i2c_hid *ihid) 458 { 459 int ret; 460 u32 ret_size; 461 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 462 463 if (size > ihid->bufsize) 464 size = ihid->bufsize; 465 466 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 467 if (ret != size) { 468 if (ret < 0) 469 return; 470 471 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 472 __func__, ret, size); 473 return; 474 } 475 476 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8; 477 478 if (!ret_size) { 479 /* host or device initiated RESET completed */ 480 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 481 wake_up(&ihid->wait); 482 return; 483 } 484 485 if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) { 486 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but " 487 "there's no data\n", __func__); 488 return; 489 } 490 491 if ((ret_size > size) || (ret_size < 2)) { 492 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n", 493 __func__, size, ret_size); 494 return; 495 } 496 497 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 498 499 if (test_bit(I2C_HID_STARTED, &ihid->flags)) 500 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2, 501 ret_size - 2, 1); 502 503 return; 504 } 505 506 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 507 { 508 struct i2c_hid *ihid = dev_id; 509 510 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) 511 return IRQ_HANDLED; 512 513 i2c_hid_get_input(ihid); 514 515 return IRQ_HANDLED; 516 } 517 518 static int i2c_hid_get_report_length(struct hid_report *report) 519 { 520 return ((report->size - 1) >> 3) + 1 + 521 report->device->report_enum[report->type].numbered + 2; 522 } 523 524 /* 525 * Traverse the supplied list of reports and find the longest 526 */ 527 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 528 unsigned int *max) 529 { 530 struct hid_report *report; 531 unsigned int size; 532 533 /* We should not rely on wMaxInputLength, as some devices may set it to 534 * a wrong length. */ 535 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 536 size = i2c_hid_get_report_length(report); 537 if (*max < size) 538 *max = size; 539 } 540 } 541 542 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 543 { 544 kfree(ihid->inbuf); 545 kfree(ihid->rawbuf); 546 kfree(ihid->argsbuf); 547 kfree(ihid->cmdbuf); 548 ihid->inbuf = NULL; 549 ihid->rawbuf = NULL; 550 ihid->cmdbuf = NULL; 551 ihid->argsbuf = NULL; 552 ihid->bufsize = 0; 553 } 554 555 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 556 { 557 /* the worst case is computed from the set_report command with a 558 * reportID > 15 and the maximum report length */ 559 int args_len = sizeof(__u8) + /* ReportID */ 560 sizeof(__u8) + /* optional ReportID byte */ 561 sizeof(__u16) + /* data register */ 562 sizeof(__u16) + /* size of the report */ 563 report_size; /* report */ 564 565 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 566 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 567 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL); 568 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL); 569 570 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) { 571 i2c_hid_free_buffers(ihid); 572 return -ENOMEM; 573 } 574 575 ihid->bufsize = report_size; 576 577 return 0; 578 } 579 580 static int i2c_hid_get_raw_report(struct hid_device *hid, 581 unsigned char report_number, __u8 *buf, size_t count, 582 unsigned char report_type) 583 { 584 struct i2c_client *client = hid->driver_data; 585 struct i2c_hid *ihid = i2c_get_clientdata(client); 586 size_t ret_count, ask_count; 587 int ret; 588 589 if (report_type == HID_OUTPUT_REPORT) 590 return -EINVAL; 591 592 /* +2 bytes to include the size of the reply in the query buffer */ 593 ask_count = min(count + 2, (size_t)ihid->bufsize); 594 595 ret = i2c_hid_get_report(client, 596 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 597 report_number, ihid->rawbuf, ask_count); 598 599 if (ret < 0) 600 return ret; 601 602 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8); 603 604 if (ret_count <= 2) 605 return 0; 606 607 ret_count = min(ret_count, ask_count); 608 609 /* The query buffer contains the size, dropping it in the reply */ 610 count = min(count, ret_count - 2); 611 memcpy(buf, ihid->rawbuf + 2, count); 612 613 return count; 614 } 615 616 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, 617 size_t count, unsigned char report_type, bool use_data) 618 { 619 struct i2c_client *client = hid->driver_data; 620 struct i2c_hid *ihid = i2c_get_clientdata(client); 621 int report_id = buf[0]; 622 int ret; 623 624 if (report_type == HID_INPUT_REPORT) 625 return -EINVAL; 626 627 mutex_lock(&ihid->reset_lock); 628 629 if (report_id) { 630 buf++; 631 count--; 632 } 633 634 ret = i2c_hid_set_or_send_report(client, 635 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 636 report_id, buf, count, use_data); 637 638 if (report_id && ret >= 0) 639 ret++; /* add report_id to the number of transfered bytes */ 640 641 mutex_unlock(&ihid->reset_lock); 642 643 return ret; 644 } 645 646 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf, 647 size_t count) 648 { 649 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT, 650 false); 651 } 652 653 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 654 __u8 *buf, size_t len, unsigned char rtype, 655 int reqtype) 656 { 657 switch (reqtype) { 658 case HID_REQ_GET_REPORT: 659 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype); 660 case HID_REQ_SET_REPORT: 661 if (buf[0] != reportnum) 662 return -EINVAL; 663 return i2c_hid_output_raw_report(hid, buf, len, rtype, true); 664 default: 665 return -EIO; 666 } 667 } 668 669 static int i2c_hid_parse(struct hid_device *hid) 670 { 671 struct i2c_client *client = hid->driver_data; 672 struct i2c_hid *ihid = i2c_get_clientdata(client); 673 struct i2c_hid_desc *hdesc = &ihid->hdesc; 674 unsigned int rsize; 675 char *rdesc; 676 int ret; 677 int tries = 3; 678 char *use_override; 679 680 i2c_hid_dbg(ihid, "entering %s\n", __func__); 681 682 rsize = le16_to_cpu(hdesc->wReportDescLength); 683 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 684 dbg_hid("weird size of report descriptor (%u)\n", rsize); 685 return -EINVAL; 686 } 687 688 do { 689 ret = i2c_hid_hwreset(client); 690 if (ret) 691 msleep(1000); 692 } while (tries-- > 0 && ret); 693 694 if (ret) 695 return ret; 696 697 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 698 &rsize); 699 700 if (use_override) { 701 rdesc = use_override; 702 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 703 } else { 704 rdesc = kzalloc(rsize, GFP_KERNEL); 705 706 if (!rdesc) { 707 dbg_hid("couldn't allocate rdesc memory\n"); 708 return -ENOMEM; 709 } 710 711 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 712 713 ret = i2c_hid_command(client, &hid_report_descr_cmd, 714 rdesc, rsize); 715 if (ret) { 716 hid_err(hid, "reading report descriptor failed\n"); 717 kfree(rdesc); 718 return -EIO; 719 } 720 } 721 722 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 723 724 ret = hid_parse_report(hid, rdesc, rsize); 725 if (!use_override) 726 kfree(rdesc); 727 728 if (ret) { 729 dbg_hid("parsing report descriptor failed\n"); 730 return ret; 731 } 732 733 return 0; 734 } 735 736 static int i2c_hid_start(struct hid_device *hid) 737 { 738 struct i2c_client *client = hid->driver_data; 739 struct i2c_hid *ihid = i2c_get_clientdata(client); 740 int ret; 741 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 742 743 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 744 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 745 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 746 747 if (bufsize > ihid->bufsize) { 748 disable_irq(client->irq); 749 i2c_hid_free_buffers(ihid); 750 751 ret = i2c_hid_alloc_buffers(ihid, bufsize); 752 enable_irq(client->irq); 753 754 if (ret) 755 return ret; 756 } 757 758 return 0; 759 } 760 761 static void i2c_hid_stop(struct hid_device *hid) 762 { 763 hid->claimed = 0; 764 } 765 766 static int i2c_hid_open(struct hid_device *hid) 767 { 768 struct i2c_client *client = hid->driver_data; 769 struct i2c_hid *ihid = i2c_get_clientdata(client); 770 771 set_bit(I2C_HID_STARTED, &ihid->flags); 772 return 0; 773 } 774 775 static void i2c_hid_close(struct hid_device *hid) 776 { 777 struct i2c_client *client = hid->driver_data; 778 struct i2c_hid *ihid = i2c_get_clientdata(client); 779 780 clear_bit(I2C_HID_STARTED, &ihid->flags); 781 } 782 783 struct hid_ll_driver i2c_hid_ll_driver = { 784 .parse = i2c_hid_parse, 785 .start = i2c_hid_start, 786 .stop = i2c_hid_stop, 787 .open = i2c_hid_open, 788 .close = i2c_hid_close, 789 .output_report = i2c_hid_output_report, 790 .raw_request = i2c_hid_raw_request, 791 }; 792 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); 793 794 static int i2c_hid_init_irq(struct i2c_client *client) 795 { 796 struct i2c_hid *ihid = i2c_get_clientdata(client); 797 unsigned long irqflags = 0; 798 int ret; 799 800 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); 801 802 if (!irq_get_trigger_type(client->irq)) 803 irqflags = IRQF_TRIGGER_LOW; 804 805 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 806 irqflags | IRQF_ONESHOT, client->name, ihid); 807 if (ret < 0) { 808 dev_warn(&client->dev, 809 "Could not register for %s interrupt, irq = %d," 810 " ret = %d\n", 811 client->name, client->irq, ret); 812 813 return ret; 814 } 815 816 return 0; 817 } 818 819 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 820 { 821 struct i2c_client *client = ihid->client; 822 struct i2c_hid_desc *hdesc = &ihid->hdesc; 823 unsigned int dsize; 824 int ret; 825 826 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 827 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 828 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 829 ihid->hdesc = 830 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 831 } else { 832 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 833 ret = i2c_hid_command(client, &hid_descr_cmd, 834 ihid->hdesc_buffer, 835 sizeof(struct i2c_hid_desc)); 836 if (ret) { 837 dev_err(&client->dev, "hid_descr_cmd failed\n"); 838 return -ENODEV; 839 } 840 } 841 842 /* Validate the length of HID descriptor, the 4 first bytes: 843 * bytes 0-1 -> length 844 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 845 /* check bcdVersion == 1.0 */ 846 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 847 dev_err(&client->dev, 848 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 849 le16_to_cpu(hdesc->bcdVersion)); 850 return -ENODEV; 851 } 852 853 /* Descriptor length should be 30 bytes as per the specification */ 854 dsize = le16_to_cpu(hdesc->wHIDDescLength); 855 if (dsize != sizeof(struct i2c_hid_desc)) { 856 dev_err(&client->dev, "weird size of HID descriptor (%u)\n", 857 dsize); 858 return -ENODEV; 859 } 860 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); 861 return 0; 862 } 863 864 #ifdef CONFIG_ACPI 865 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { 866 /* 867 * The CHPN0001 ACPI device, which is used to describe the Chipone 868 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. 869 */ 870 {"CHPN0001", 0 }, 871 { }, 872 }; 873 874 static int i2c_hid_acpi_pdata(struct i2c_client *client, 875 struct i2c_hid_platform_data *pdata) 876 { 877 static guid_t i2c_hid_guid = 878 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 879 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); 880 union acpi_object *obj; 881 struct acpi_device *adev; 882 acpi_handle handle; 883 884 handle = ACPI_HANDLE(&client->dev); 885 if (!handle || acpi_bus_get_device(handle, &adev)) { 886 dev_err(&client->dev, "Error could not get ACPI device\n"); 887 return -ENODEV; 888 } 889 890 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 891 return -ENODEV; 892 893 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 894 ACPI_TYPE_INTEGER); 895 if (!obj) { 896 dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n"); 897 return -ENODEV; 898 } 899 900 pdata->hid_descriptor_address = obj->integer.value; 901 ACPI_FREE(obj); 902 903 return 0; 904 } 905 906 static void i2c_hid_acpi_fix_up_power(struct device *dev) 907 { 908 struct acpi_device *adev; 909 910 adev = ACPI_COMPANION(dev); 911 if (adev) 912 acpi_device_fix_up_power(adev); 913 } 914 915 static const struct acpi_device_id i2c_hid_acpi_match[] = { 916 {"ACPI0C50", 0 }, 917 {"PNP0C50", 0 }, 918 { }, 919 }; 920 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 921 #else 922 static inline int i2c_hid_acpi_pdata(struct i2c_client *client, 923 struct i2c_hid_platform_data *pdata) 924 { 925 return -ENODEV; 926 } 927 928 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} 929 #endif 930 931 #ifdef CONFIG_OF 932 static int i2c_hid_of_probe(struct i2c_client *client, 933 struct i2c_hid_platform_data *pdata) 934 { 935 struct device *dev = &client->dev; 936 u32 val; 937 int ret; 938 939 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); 940 if (ret) { 941 dev_err(&client->dev, "HID register address not provided\n"); 942 return -ENODEV; 943 } 944 if (val >> 16) { 945 dev_err(&client->dev, "Bad HID register address: 0x%08x\n", 946 val); 947 return -EINVAL; 948 } 949 pdata->hid_descriptor_address = val; 950 951 return 0; 952 } 953 954 static const struct of_device_id i2c_hid_of_match[] = { 955 { .compatible = "hid-over-i2c" }, 956 {}, 957 }; 958 MODULE_DEVICE_TABLE(of, i2c_hid_of_match); 959 #else 960 static inline int i2c_hid_of_probe(struct i2c_client *client, 961 struct i2c_hid_platform_data *pdata) 962 { 963 return -ENODEV; 964 } 965 #endif 966 967 static void i2c_hid_fwnode_probe(struct i2c_client *client, 968 struct i2c_hid_platform_data *pdata) 969 { 970 u32 val; 971 972 if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms", 973 &val)) 974 pdata->post_power_delay_ms = val; 975 } 976 977 static int i2c_hid_probe(struct i2c_client *client, 978 const struct i2c_device_id *dev_id) 979 { 980 int ret; 981 struct i2c_hid *ihid; 982 struct hid_device *hid; 983 __u16 hidRegister; 984 struct i2c_hid_platform_data *platform_data = client->dev.platform_data; 985 986 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 987 988 if (!client->irq) { 989 dev_err(&client->dev, 990 "HID over i2c has not been provided an Int IRQ\n"); 991 return -EINVAL; 992 } 993 994 if (client->irq < 0) { 995 if (client->irq != -EPROBE_DEFER) 996 dev_err(&client->dev, 997 "HID over i2c doesn't have a valid IRQ\n"); 998 return client->irq; 999 } 1000 1001 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1002 if (!ihid) 1003 return -ENOMEM; 1004 1005 if (client->dev.of_node) { 1006 ret = i2c_hid_of_probe(client, &ihid->pdata); 1007 if (ret) 1008 return ret; 1009 } else if (!platform_data) { 1010 ret = i2c_hid_acpi_pdata(client, &ihid->pdata); 1011 if (ret) 1012 return ret; 1013 } else { 1014 ihid->pdata = *platform_data; 1015 } 1016 1017 /* Parse platform agnostic common properties from ACPI / device tree */ 1018 i2c_hid_fwnode_probe(client, &ihid->pdata); 1019 1020 ihid->pdata.supplies[0].supply = "vdd"; 1021 ihid->pdata.supplies[1].supply = "vddl"; 1022 1023 ret = devm_regulator_bulk_get(&client->dev, 1024 ARRAY_SIZE(ihid->pdata.supplies), 1025 ihid->pdata.supplies); 1026 if (ret) 1027 return ret; 1028 1029 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1030 ihid->pdata.supplies); 1031 if (ret < 0) 1032 return ret; 1033 1034 if (ihid->pdata.post_power_delay_ms) 1035 msleep(ihid->pdata.post_power_delay_ms); 1036 1037 i2c_set_clientdata(client, ihid); 1038 1039 ihid->client = client; 1040 1041 hidRegister = ihid->pdata.hid_descriptor_address; 1042 ihid->wHIDDescRegister = cpu_to_le16(hidRegister); 1043 1044 init_waitqueue_head(&ihid->wait); 1045 mutex_init(&ihid->reset_lock); 1046 1047 /* we need to allocate the command buffer without knowing the maximum 1048 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1049 * real computation later. */ 1050 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1051 if (ret < 0) 1052 goto err_regulator; 1053 1054 i2c_hid_acpi_fix_up_power(&client->dev); 1055 1056 device_enable_async_suspend(&client->dev); 1057 1058 /* Make sure there is something at this address */ 1059 ret = i2c_smbus_read_byte(client); 1060 if (ret < 0) { 1061 dev_dbg(&client->dev, "nothing at this address: %d\n", ret); 1062 ret = -ENXIO; 1063 goto err_regulator; 1064 } 1065 1066 ret = i2c_hid_fetch_hid_descriptor(ihid); 1067 if (ret < 0) 1068 goto err_regulator; 1069 1070 ret = i2c_hid_init_irq(client); 1071 if (ret < 0) 1072 goto err_regulator; 1073 1074 hid = hid_allocate_device(); 1075 if (IS_ERR(hid)) { 1076 ret = PTR_ERR(hid); 1077 goto err_irq; 1078 } 1079 1080 ihid->hid = hid; 1081 1082 hid->driver_data = client; 1083 hid->ll_driver = &i2c_hid_ll_driver; 1084 hid->dev.parent = &client->dev; 1085 hid->bus = BUS_I2C; 1086 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1087 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1088 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1089 1090 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX", 1091 client->name, hid->vendor, hid->product); 1092 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1093 1094 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1095 1096 ret = hid_add_device(hid); 1097 if (ret) { 1098 if (ret != -ENODEV) 1099 hid_err(client, "can't add hid device: %d\n", ret); 1100 goto err_mem_free; 1101 } 1102 1103 return 0; 1104 1105 err_mem_free: 1106 hid_destroy_device(hid); 1107 1108 err_irq: 1109 free_irq(client->irq, ihid); 1110 1111 err_regulator: 1112 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1113 ihid->pdata.supplies); 1114 i2c_hid_free_buffers(ihid); 1115 return ret; 1116 } 1117 1118 static int i2c_hid_remove(struct i2c_client *client) 1119 { 1120 struct i2c_hid *ihid = i2c_get_clientdata(client); 1121 struct hid_device *hid; 1122 1123 hid = ihid->hid; 1124 hid_destroy_device(hid); 1125 1126 free_irq(client->irq, ihid); 1127 1128 if (ihid->bufsize) 1129 i2c_hid_free_buffers(ihid); 1130 1131 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1132 ihid->pdata.supplies); 1133 1134 return 0; 1135 } 1136 1137 static void i2c_hid_shutdown(struct i2c_client *client) 1138 { 1139 struct i2c_hid *ihid = i2c_get_clientdata(client); 1140 1141 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1142 free_irq(client->irq, ihid); 1143 } 1144 1145 #ifdef CONFIG_PM_SLEEP 1146 static int i2c_hid_suspend(struct device *dev) 1147 { 1148 struct i2c_client *client = to_i2c_client(dev); 1149 struct i2c_hid *ihid = i2c_get_clientdata(client); 1150 struct hid_device *hid = ihid->hid; 1151 int ret; 1152 int wake_status; 1153 1154 if (hid->driver && hid->driver->suspend) { 1155 ret = hid->driver->suspend(hid, PMSG_SUSPEND); 1156 if (ret < 0) 1157 return ret; 1158 } 1159 1160 /* Save some power */ 1161 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1162 1163 disable_irq(client->irq); 1164 1165 if (device_may_wakeup(&client->dev)) { 1166 wake_status = enable_irq_wake(client->irq); 1167 if (!wake_status) 1168 ihid->irq_wake_enabled = true; 1169 else 1170 hid_warn(hid, "Failed to enable irq wake: %d\n", 1171 wake_status); 1172 } else { 1173 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1174 ihid->pdata.supplies); 1175 } 1176 1177 return 0; 1178 } 1179 1180 static int i2c_hid_resume(struct device *dev) 1181 { 1182 int ret; 1183 struct i2c_client *client = to_i2c_client(dev); 1184 struct i2c_hid *ihid = i2c_get_clientdata(client); 1185 struct hid_device *hid = ihid->hid; 1186 int wake_status; 1187 1188 if (!device_may_wakeup(&client->dev)) { 1189 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1190 ihid->pdata.supplies); 1191 if (ret) 1192 hid_warn(hid, "Failed to enable supplies: %d\n", ret); 1193 1194 if (ihid->pdata.post_power_delay_ms) 1195 msleep(ihid->pdata.post_power_delay_ms); 1196 } else if (ihid->irq_wake_enabled) { 1197 wake_status = disable_irq_wake(client->irq); 1198 if (!wake_status) 1199 ihid->irq_wake_enabled = false; 1200 else 1201 hid_warn(hid, "Failed to disable irq wake: %d\n", 1202 wake_status); 1203 } 1204 1205 enable_irq(client->irq); 1206 1207 /* Instead of resetting device, simply powers the device on. This 1208 * solves "incomplete reports" on Raydium devices 2386:3118 and 1209 * 2386:4B33 and fixes various SIS touchscreens no longer sending 1210 * data after a suspend/resume. 1211 */ 1212 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 1213 if (ret) 1214 return ret; 1215 1216 if (hid->driver && hid->driver->reset_resume) { 1217 ret = hid->driver->reset_resume(hid); 1218 return ret; 1219 } 1220 1221 return 0; 1222 } 1223 #endif 1224 1225 static const struct dev_pm_ops i2c_hid_pm = { 1226 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume) 1227 }; 1228 1229 static const struct i2c_device_id i2c_hid_id_table[] = { 1230 { "hid", 0 }, 1231 { "hid-over-i2c", 0 }, 1232 { }, 1233 }; 1234 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); 1235 1236 1237 static struct i2c_driver i2c_hid_driver = { 1238 .driver = { 1239 .name = "i2c_hid", 1240 .pm = &i2c_hid_pm, 1241 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), 1242 .of_match_table = of_match_ptr(i2c_hid_of_match), 1243 }, 1244 1245 .probe = i2c_hid_probe, 1246 .remove = i2c_hid_remove, 1247 .shutdown = i2c_hid_shutdown, 1248 .id_table = i2c_hid_id_table, 1249 }; 1250 1251 module_i2c_driver(i2c_hid_driver); 1252 1253 MODULE_DESCRIPTION("HID over I2C core driver"); 1254 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1255 MODULE_LICENSE("GPL"); 1256