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 goto out_unlock; 451 } 452 453 /* At least some SIS devices need this after reset */ 454 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 455 456 out_unlock: 457 mutex_unlock(&ihid->reset_lock); 458 return ret; 459 } 460 461 static void i2c_hid_get_input(struct i2c_hid *ihid) 462 { 463 int ret; 464 u32 ret_size; 465 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 466 467 if (size > ihid->bufsize) 468 size = ihid->bufsize; 469 470 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 471 if (ret != size) { 472 if (ret < 0) 473 return; 474 475 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 476 __func__, ret, size); 477 return; 478 } 479 480 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8; 481 482 if (!ret_size) { 483 /* host or device initiated RESET completed */ 484 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 485 wake_up(&ihid->wait); 486 return; 487 } 488 489 if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) { 490 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but " 491 "there's no data\n", __func__); 492 return; 493 } 494 495 if ((ret_size > size) || (ret_size < 2)) { 496 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n", 497 __func__, size, ret_size); 498 return; 499 } 500 501 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 502 503 if (test_bit(I2C_HID_STARTED, &ihid->flags)) 504 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2, 505 ret_size - 2, 1); 506 507 return; 508 } 509 510 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 511 { 512 struct i2c_hid *ihid = dev_id; 513 514 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) 515 return IRQ_HANDLED; 516 517 i2c_hid_get_input(ihid); 518 519 return IRQ_HANDLED; 520 } 521 522 static int i2c_hid_get_report_length(struct hid_report *report) 523 { 524 return ((report->size - 1) >> 3) + 1 + 525 report->device->report_enum[report->type].numbered + 2; 526 } 527 528 /* 529 * Traverse the supplied list of reports and find the longest 530 */ 531 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 532 unsigned int *max) 533 { 534 struct hid_report *report; 535 unsigned int size; 536 537 /* We should not rely on wMaxInputLength, as some devices may set it to 538 * a wrong length. */ 539 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 540 size = i2c_hid_get_report_length(report); 541 if (*max < size) 542 *max = size; 543 } 544 } 545 546 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 547 { 548 kfree(ihid->inbuf); 549 kfree(ihid->rawbuf); 550 kfree(ihid->argsbuf); 551 kfree(ihid->cmdbuf); 552 ihid->inbuf = NULL; 553 ihid->rawbuf = NULL; 554 ihid->cmdbuf = NULL; 555 ihid->argsbuf = NULL; 556 ihid->bufsize = 0; 557 } 558 559 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 560 { 561 /* the worst case is computed from the set_report command with a 562 * reportID > 15 and the maximum report length */ 563 int args_len = sizeof(__u8) + /* ReportID */ 564 sizeof(__u8) + /* optional ReportID byte */ 565 sizeof(__u16) + /* data register */ 566 sizeof(__u16) + /* size of the report */ 567 report_size; /* report */ 568 569 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 570 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 571 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL); 572 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL); 573 574 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) { 575 i2c_hid_free_buffers(ihid); 576 return -ENOMEM; 577 } 578 579 ihid->bufsize = report_size; 580 581 return 0; 582 } 583 584 static int i2c_hid_get_raw_report(struct hid_device *hid, 585 unsigned char report_number, __u8 *buf, size_t count, 586 unsigned char report_type) 587 { 588 struct i2c_client *client = hid->driver_data; 589 struct i2c_hid *ihid = i2c_get_clientdata(client); 590 size_t ret_count, ask_count; 591 int ret; 592 593 if (report_type == HID_OUTPUT_REPORT) 594 return -EINVAL; 595 596 /* +2 bytes to include the size of the reply in the query buffer */ 597 ask_count = min(count + 2, (size_t)ihid->bufsize); 598 599 ret = i2c_hid_get_report(client, 600 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 601 report_number, ihid->rawbuf, ask_count); 602 603 if (ret < 0) 604 return ret; 605 606 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8); 607 608 if (ret_count <= 2) 609 return 0; 610 611 ret_count = min(ret_count, ask_count); 612 613 /* The query buffer contains the size, dropping it in the reply */ 614 count = min(count, ret_count - 2); 615 memcpy(buf, ihid->rawbuf + 2, count); 616 617 return count; 618 } 619 620 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, 621 size_t count, unsigned char report_type, bool use_data) 622 { 623 struct i2c_client *client = hid->driver_data; 624 struct i2c_hid *ihid = i2c_get_clientdata(client); 625 int report_id = buf[0]; 626 int ret; 627 628 if (report_type == HID_INPUT_REPORT) 629 return -EINVAL; 630 631 mutex_lock(&ihid->reset_lock); 632 633 if (report_id) { 634 buf++; 635 count--; 636 } 637 638 ret = i2c_hid_set_or_send_report(client, 639 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 640 report_id, buf, count, use_data); 641 642 if (report_id && ret >= 0) 643 ret++; /* add report_id to the number of transfered bytes */ 644 645 mutex_unlock(&ihid->reset_lock); 646 647 return ret; 648 } 649 650 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf, 651 size_t count) 652 { 653 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT, 654 false); 655 } 656 657 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 658 __u8 *buf, size_t len, unsigned char rtype, 659 int reqtype) 660 { 661 switch (reqtype) { 662 case HID_REQ_GET_REPORT: 663 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype); 664 case HID_REQ_SET_REPORT: 665 if (buf[0] != reportnum) 666 return -EINVAL; 667 return i2c_hid_output_raw_report(hid, buf, len, rtype, true); 668 default: 669 return -EIO; 670 } 671 } 672 673 static int i2c_hid_parse(struct hid_device *hid) 674 { 675 struct i2c_client *client = hid->driver_data; 676 struct i2c_hid *ihid = i2c_get_clientdata(client); 677 struct i2c_hid_desc *hdesc = &ihid->hdesc; 678 unsigned int rsize; 679 char *rdesc; 680 int ret; 681 int tries = 3; 682 char *use_override; 683 684 i2c_hid_dbg(ihid, "entering %s\n", __func__); 685 686 rsize = le16_to_cpu(hdesc->wReportDescLength); 687 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 688 dbg_hid("weird size of report descriptor (%u)\n", rsize); 689 return -EINVAL; 690 } 691 692 do { 693 ret = i2c_hid_hwreset(client); 694 if (ret) 695 msleep(1000); 696 } while (tries-- > 0 && ret); 697 698 if (ret) 699 return ret; 700 701 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 702 &rsize); 703 704 if (use_override) { 705 rdesc = use_override; 706 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 707 } else { 708 rdesc = kzalloc(rsize, GFP_KERNEL); 709 710 if (!rdesc) { 711 dbg_hid("couldn't allocate rdesc memory\n"); 712 return -ENOMEM; 713 } 714 715 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 716 717 ret = i2c_hid_command(client, &hid_report_descr_cmd, 718 rdesc, rsize); 719 if (ret) { 720 hid_err(hid, "reading report descriptor failed\n"); 721 kfree(rdesc); 722 return -EIO; 723 } 724 } 725 726 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 727 728 ret = hid_parse_report(hid, rdesc, rsize); 729 if (!use_override) 730 kfree(rdesc); 731 732 if (ret) { 733 dbg_hid("parsing report descriptor failed\n"); 734 return ret; 735 } 736 737 return 0; 738 } 739 740 static int i2c_hid_start(struct hid_device *hid) 741 { 742 struct i2c_client *client = hid->driver_data; 743 struct i2c_hid *ihid = i2c_get_clientdata(client); 744 int ret; 745 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 746 747 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 748 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 749 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 750 751 if (bufsize > ihid->bufsize) { 752 disable_irq(client->irq); 753 i2c_hid_free_buffers(ihid); 754 755 ret = i2c_hid_alloc_buffers(ihid, bufsize); 756 enable_irq(client->irq); 757 758 if (ret) 759 return ret; 760 } 761 762 return 0; 763 } 764 765 static void i2c_hid_stop(struct hid_device *hid) 766 { 767 hid->claimed = 0; 768 } 769 770 static int i2c_hid_open(struct hid_device *hid) 771 { 772 struct i2c_client *client = hid->driver_data; 773 struct i2c_hid *ihid = i2c_get_clientdata(client); 774 775 set_bit(I2C_HID_STARTED, &ihid->flags); 776 return 0; 777 } 778 779 static void i2c_hid_close(struct hid_device *hid) 780 { 781 struct i2c_client *client = hid->driver_data; 782 struct i2c_hid *ihid = i2c_get_clientdata(client); 783 784 clear_bit(I2C_HID_STARTED, &ihid->flags); 785 } 786 787 struct hid_ll_driver i2c_hid_ll_driver = { 788 .parse = i2c_hid_parse, 789 .start = i2c_hid_start, 790 .stop = i2c_hid_stop, 791 .open = i2c_hid_open, 792 .close = i2c_hid_close, 793 .output_report = i2c_hid_output_report, 794 .raw_request = i2c_hid_raw_request, 795 }; 796 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); 797 798 static int i2c_hid_init_irq(struct i2c_client *client) 799 { 800 struct i2c_hid *ihid = i2c_get_clientdata(client); 801 unsigned long irqflags = 0; 802 int ret; 803 804 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); 805 806 if (!irq_get_trigger_type(client->irq)) 807 irqflags = IRQF_TRIGGER_LOW; 808 809 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 810 irqflags | IRQF_ONESHOT, client->name, ihid); 811 if (ret < 0) { 812 dev_warn(&client->dev, 813 "Could not register for %s interrupt, irq = %d," 814 " ret = %d\n", 815 client->name, client->irq, ret); 816 817 return ret; 818 } 819 820 return 0; 821 } 822 823 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 824 { 825 struct i2c_client *client = ihid->client; 826 struct i2c_hid_desc *hdesc = &ihid->hdesc; 827 unsigned int dsize; 828 int ret; 829 830 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 831 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 832 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 833 ihid->hdesc = 834 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 835 } else { 836 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 837 ret = i2c_hid_command(client, &hid_descr_cmd, 838 ihid->hdesc_buffer, 839 sizeof(struct i2c_hid_desc)); 840 if (ret) { 841 dev_err(&client->dev, "hid_descr_cmd failed\n"); 842 return -ENODEV; 843 } 844 } 845 846 /* Validate the length of HID descriptor, the 4 first bytes: 847 * bytes 0-1 -> length 848 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 849 /* check bcdVersion == 1.0 */ 850 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 851 dev_err(&client->dev, 852 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 853 le16_to_cpu(hdesc->bcdVersion)); 854 return -ENODEV; 855 } 856 857 /* Descriptor length should be 30 bytes as per the specification */ 858 dsize = le16_to_cpu(hdesc->wHIDDescLength); 859 if (dsize != sizeof(struct i2c_hid_desc)) { 860 dev_err(&client->dev, "weird size of HID descriptor (%u)\n", 861 dsize); 862 return -ENODEV; 863 } 864 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); 865 return 0; 866 } 867 868 #ifdef CONFIG_ACPI 869 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { 870 /* 871 * The CHPN0001 ACPI device, which is used to describe the Chipone 872 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. 873 */ 874 {"CHPN0001", 0 }, 875 { }, 876 }; 877 878 static int i2c_hid_acpi_pdata(struct i2c_client *client, 879 struct i2c_hid_platform_data *pdata) 880 { 881 static guid_t i2c_hid_guid = 882 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 883 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); 884 union acpi_object *obj; 885 struct acpi_device *adev; 886 acpi_handle handle; 887 888 handle = ACPI_HANDLE(&client->dev); 889 if (!handle || acpi_bus_get_device(handle, &adev)) { 890 dev_err(&client->dev, "Error could not get ACPI device\n"); 891 return -ENODEV; 892 } 893 894 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 895 return -ENODEV; 896 897 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 898 ACPI_TYPE_INTEGER); 899 if (!obj) { 900 dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n"); 901 return -ENODEV; 902 } 903 904 pdata->hid_descriptor_address = obj->integer.value; 905 ACPI_FREE(obj); 906 907 return 0; 908 } 909 910 static void i2c_hid_acpi_fix_up_power(struct device *dev) 911 { 912 struct acpi_device *adev; 913 914 adev = ACPI_COMPANION(dev); 915 if (adev) 916 acpi_device_fix_up_power(adev); 917 } 918 919 static const struct acpi_device_id i2c_hid_acpi_match[] = { 920 {"ACPI0C50", 0 }, 921 {"PNP0C50", 0 }, 922 { }, 923 }; 924 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 925 #else 926 static inline int i2c_hid_acpi_pdata(struct i2c_client *client, 927 struct i2c_hid_platform_data *pdata) 928 { 929 return -ENODEV; 930 } 931 932 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} 933 #endif 934 935 #ifdef CONFIG_OF 936 static int i2c_hid_of_probe(struct i2c_client *client, 937 struct i2c_hid_platform_data *pdata) 938 { 939 struct device *dev = &client->dev; 940 u32 val; 941 int ret; 942 943 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); 944 if (ret) { 945 dev_err(&client->dev, "HID register address not provided\n"); 946 return -ENODEV; 947 } 948 if (val >> 16) { 949 dev_err(&client->dev, "Bad HID register address: 0x%08x\n", 950 val); 951 return -EINVAL; 952 } 953 pdata->hid_descriptor_address = val; 954 955 return 0; 956 } 957 958 static const struct of_device_id i2c_hid_of_match[] = { 959 { .compatible = "hid-over-i2c" }, 960 {}, 961 }; 962 MODULE_DEVICE_TABLE(of, i2c_hid_of_match); 963 #else 964 static inline int i2c_hid_of_probe(struct i2c_client *client, 965 struct i2c_hid_platform_data *pdata) 966 { 967 return -ENODEV; 968 } 969 #endif 970 971 static void i2c_hid_fwnode_probe(struct i2c_client *client, 972 struct i2c_hid_platform_data *pdata) 973 { 974 u32 val; 975 976 if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms", 977 &val)) 978 pdata->post_power_delay_ms = val; 979 } 980 981 static int i2c_hid_probe(struct i2c_client *client, 982 const struct i2c_device_id *dev_id) 983 { 984 int ret; 985 struct i2c_hid *ihid; 986 struct hid_device *hid; 987 __u16 hidRegister; 988 struct i2c_hid_platform_data *platform_data = client->dev.platform_data; 989 990 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 991 992 if (!client->irq) { 993 dev_err(&client->dev, 994 "HID over i2c has not been provided an Int IRQ\n"); 995 return -EINVAL; 996 } 997 998 if (client->irq < 0) { 999 if (client->irq != -EPROBE_DEFER) 1000 dev_err(&client->dev, 1001 "HID over i2c doesn't have a valid IRQ\n"); 1002 return client->irq; 1003 } 1004 1005 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1006 if (!ihid) 1007 return -ENOMEM; 1008 1009 if (client->dev.of_node) { 1010 ret = i2c_hid_of_probe(client, &ihid->pdata); 1011 if (ret) 1012 return ret; 1013 } else if (!platform_data) { 1014 ret = i2c_hid_acpi_pdata(client, &ihid->pdata); 1015 if (ret) 1016 return ret; 1017 } else { 1018 ihid->pdata = *platform_data; 1019 } 1020 1021 /* Parse platform agnostic common properties from ACPI / device tree */ 1022 i2c_hid_fwnode_probe(client, &ihid->pdata); 1023 1024 ihid->pdata.supplies[0].supply = "vdd"; 1025 ihid->pdata.supplies[1].supply = "vddl"; 1026 1027 ret = devm_regulator_bulk_get(&client->dev, 1028 ARRAY_SIZE(ihid->pdata.supplies), 1029 ihid->pdata.supplies); 1030 if (ret) 1031 return ret; 1032 1033 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1034 ihid->pdata.supplies); 1035 if (ret < 0) 1036 return ret; 1037 1038 if (ihid->pdata.post_power_delay_ms) 1039 msleep(ihid->pdata.post_power_delay_ms); 1040 1041 i2c_set_clientdata(client, ihid); 1042 1043 ihid->client = client; 1044 1045 hidRegister = ihid->pdata.hid_descriptor_address; 1046 ihid->wHIDDescRegister = cpu_to_le16(hidRegister); 1047 1048 init_waitqueue_head(&ihid->wait); 1049 mutex_init(&ihid->reset_lock); 1050 1051 /* we need to allocate the command buffer without knowing the maximum 1052 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1053 * real computation later. */ 1054 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1055 if (ret < 0) 1056 goto err_regulator; 1057 1058 i2c_hid_acpi_fix_up_power(&client->dev); 1059 1060 device_enable_async_suspend(&client->dev); 1061 1062 /* Make sure there is something at this address */ 1063 ret = i2c_smbus_read_byte(client); 1064 if (ret < 0) { 1065 dev_dbg(&client->dev, "nothing at this address: %d\n", ret); 1066 ret = -ENXIO; 1067 goto err_regulator; 1068 } 1069 1070 ret = i2c_hid_fetch_hid_descriptor(ihid); 1071 if (ret < 0) 1072 goto err_regulator; 1073 1074 ret = i2c_hid_init_irq(client); 1075 if (ret < 0) 1076 goto err_regulator; 1077 1078 hid = hid_allocate_device(); 1079 if (IS_ERR(hid)) { 1080 ret = PTR_ERR(hid); 1081 goto err_irq; 1082 } 1083 1084 ihid->hid = hid; 1085 1086 hid->driver_data = client; 1087 hid->ll_driver = &i2c_hid_ll_driver; 1088 hid->dev.parent = &client->dev; 1089 hid->bus = BUS_I2C; 1090 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1091 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1092 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1093 1094 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX", 1095 client->name, hid->vendor, hid->product); 1096 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1097 1098 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1099 1100 ret = hid_add_device(hid); 1101 if (ret) { 1102 if (ret != -ENODEV) 1103 hid_err(client, "can't add hid device: %d\n", ret); 1104 goto err_mem_free; 1105 } 1106 1107 return 0; 1108 1109 err_mem_free: 1110 hid_destroy_device(hid); 1111 1112 err_irq: 1113 free_irq(client->irq, ihid); 1114 1115 err_regulator: 1116 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1117 ihid->pdata.supplies); 1118 i2c_hid_free_buffers(ihid); 1119 return ret; 1120 } 1121 1122 static int i2c_hid_remove(struct i2c_client *client) 1123 { 1124 struct i2c_hid *ihid = i2c_get_clientdata(client); 1125 struct hid_device *hid; 1126 1127 hid = ihid->hid; 1128 hid_destroy_device(hid); 1129 1130 free_irq(client->irq, ihid); 1131 1132 if (ihid->bufsize) 1133 i2c_hid_free_buffers(ihid); 1134 1135 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1136 ihid->pdata.supplies); 1137 1138 return 0; 1139 } 1140 1141 static void i2c_hid_shutdown(struct i2c_client *client) 1142 { 1143 struct i2c_hid *ihid = i2c_get_clientdata(client); 1144 1145 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1146 free_irq(client->irq, ihid); 1147 } 1148 1149 #ifdef CONFIG_PM_SLEEP 1150 static int i2c_hid_suspend(struct device *dev) 1151 { 1152 struct i2c_client *client = to_i2c_client(dev); 1153 struct i2c_hid *ihid = i2c_get_clientdata(client); 1154 struct hid_device *hid = ihid->hid; 1155 int ret; 1156 int wake_status; 1157 1158 if (hid->driver && hid->driver->suspend) { 1159 ret = hid->driver->suspend(hid, PMSG_SUSPEND); 1160 if (ret < 0) 1161 return ret; 1162 } 1163 1164 /* Save some power */ 1165 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1166 1167 disable_irq(client->irq); 1168 1169 if (device_may_wakeup(&client->dev)) { 1170 wake_status = enable_irq_wake(client->irq); 1171 if (!wake_status) 1172 ihid->irq_wake_enabled = true; 1173 else 1174 hid_warn(hid, "Failed to enable irq wake: %d\n", 1175 wake_status); 1176 } else { 1177 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1178 ihid->pdata.supplies); 1179 } 1180 1181 return 0; 1182 } 1183 1184 static int i2c_hid_resume(struct device *dev) 1185 { 1186 int ret; 1187 struct i2c_client *client = to_i2c_client(dev); 1188 struct i2c_hid *ihid = i2c_get_clientdata(client); 1189 struct hid_device *hid = ihid->hid; 1190 int wake_status; 1191 1192 if (!device_may_wakeup(&client->dev)) { 1193 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1194 ihid->pdata.supplies); 1195 if (ret) 1196 hid_warn(hid, "Failed to enable supplies: %d\n", ret); 1197 1198 if (ihid->pdata.post_power_delay_ms) 1199 msleep(ihid->pdata.post_power_delay_ms); 1200 } else if (ihid->irq_wake_enabled) { 1201 wake_status = disable_irq_wake(client->irq); 1202 if (!wake_status) 1203 ihid->irq_wake_enabled = false; 1204 else 1205 hid_warn(hid, "Failed to disable irq wake: %d\n", 1206 wake_status); 1207 } 1208 1209 enable_irq(client->irq); 1210 1211 /* Instead of resetting device, simply powers the device on. This 1212 * solves "incomplete reports" on Raydium devices 2386:3118 and 1213 * 2386:4B33 and fixes various SIS touchscreens no longer sending 1214 * data after a suspend/resume. 1215 */ 1216 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 1217 if (ret) 1218 return ret; 1219 1220 if (hid->driver && hid->driver->reset_resume) { 1221 ret = hid->driver->reset_resume(hid); 1222 return ret; 1223 } 1224 1225 return 0; 1226 } 1227 #endif 1228 1229 static const struct dev_pm_ops i2c_hid_pm = { 1230 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume) 1231 }; 1232 1233 static const struct i2c_device_id i2c_hid_id_table[] = { 1234 { "hid", 0 }, 1235 { "hid-over-i2c", 0 }, 1236 { }, 1237 }; 1238 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); 1239 1240 1241 static struct i2c_driver i2c_hid_driver = { 1242 .driver = { 1243 .name = "i2c_hid", 1244 .pm = &i2c_hid_pm, 1245 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), 1246 .of_match_table = of_match_ptr(i2c_hid_of_match), 1247 }, 1248 1249 .probe = i2c_hid_probe, 1250 .remove = i2c_hid_remove, 1251 .shutdown = i2c_hid_shutdown, 1252 .id_table = i2c_hid_id_table, 1253 }; 1254 1255 module_i2c_driver(i2c_hid_driver); 1256 1257 MODULE_DESCRIPTION("HID over I2C core driver"); 1258 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1259 MODULE_LICENSE("GPL"); 1260