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 53 /* flags */ 54 #define I2C_HID_STARTED 0 55 #define I2C_HID_RESET_PENDING 1 56 #define I2C_HID_READ_PENDING 2 57 58 #define I2C_HID_PWR_ON 0x00 59 #define I2C_HID_PWR_SLEEP 0x01 60 61 /* debug option */ 62 static bool debug; 63 module_param(debug, bool, 0444); 64 MODULE_PARM_DESC(debug, "print a lot of debug information"); 65 66 #define i2c_hid_dbg(ihid, fmt, arg...) \ 67 do { \ 68 if (debug) \ 69 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \ 70 } while (0) 71 72 struct i2c_hid_desc { 73 __le16 wHIDDescLength; 74 __le16 bcdVersion; 75 __le16 wReportDescLength; 76 __le16 wReportDescRegister; 77 __le16 wInputRegister; 78 __le16 wMaxInputLength; 79 __le16 wOutputRegister; 80 __le16 wMaxOutputLength; 81 __le16 wCommandRegister; 82 __le16 wDataRegister; 83 __le16 wVendorID; 84 __le16 wProductID; 85 __le16 wVersionID; 86 __le32 reserved; 87 } __packed; 88 89 struct i2c_hid_cmd { 90 unsigned int registerIndex; 91 __u8 opcode; 92 unsigned int length; 93 bool wait; 94 }; 95 96 union command { 97 u8 data[0]; 98 struct cmd { 99 __le16 reg; 100 __u8 reportTypeID; 101 __u8 opcode; 102 } __packed c; 103 }; 104 105 #define I2C_HID_CMD(opcode_) \ 106 .opcode = opcode_, .length = 4, \ 107 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister) 108 109 /* fetch HID descriptor */ 110 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 }; 111 /* fetch report descriptors */ 112 static const struct i2c_hid_cmd hid_report_descr_cmd = { 113 .registerIndex = offsetof(struct i2c_hid_desc, 114 wReportDescRegister), 115 .opcode = 0x00, 116 .length = 2 }; 117 /* commands */ 118 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01), 119 .wait = true }; 120 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) }; 121 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) }; 122 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) }; 123 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 }; 124 125 /* 126 * These definitions are not used here, but are defined by the spec. 127 * Keeping them here for documentation purposes. 128 * 129 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) }; 130 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) }; 131 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) }; 132 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) }; 133 */ 134 135 /* The main device structure */ 136 struct i2c_hid { 137 struct i2c_client *client; /* i2c client */ 138 struct hid_device *hid; /* pointer to corresponding HID dev */ 139 union { 140 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)]; 141 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 142 }; 143 __le16 wHIDDescRegister; /* location of the i2c 144 * register of the HID 145 * descriptor. */ 146 unsigned int bufsize; /* i2c buffer size */ 147 u8 *inbuf; /* Input buffer */ 148 u8 *rawbuf; /* Raw Input buffer */ 149 u8 *cmdbuf; /* Command buffer */ 150 u8 *argsbuf; /* Command arguments buffer */ 151 152 unsigned long flags; /* device flags */ 153 unsigned long quirks; /* Various quirks */ 154 155 wait_queue_head_t wait; /* For waiting the interrupt */ 156 157 struct i2c_hid_platform_data pdata; 158 159 bool irq_wake_enabled; 160 struct mutex reset_lock; 161 }; 162 163 static const struct i2c_hid_quirks { 164 __u16 idVendor; 165 __u16 idProduct; 166 __u32 quirks; 167 } i2c_hid_quirks[] = { 168 { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752, 169 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, 170 { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755, 171 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, 172 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 173 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET | 174 I2C_HID_QUIRK_NO_RUNTIME_PM }, 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 ((ret_size > size) || (ret_size < 2)) { 486 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n", 487 __func__, size, ret_size); 488 return; 489 } 490 491 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 492 493 if (test_bit(I2C_HID_STARTED, &ihid->flags)) 494 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2, 495 ret_size - 2, 1); 496 497 return; 498 } 499 500 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 501 { 502 struct i2c_hid *ihid = dev_id; 503 504 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) 505 return IRQ_HANDLED; 506 507 i2c_hid_get_input(ihid); 508 509 return IRQ_HANDLED; 510 } 511 512 static int i2c_hid_get_report_length(struct hid_report *report) 513 { 514 return ((report->size - 1) >> 3) + 1 + 515 report->device->report_enum[report->type].numbered + 2; 516 } 517 518 /* 519 * Traverse the supplied list of reports and find the longest 520 */ 521 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 522 unsigned int *max) 523 { 524 struct hid_report *report; 525 unsigned int size; 526 527 /* We should not rely on wMaxInputLength, as some devices may set it to 528 * a wrong length. */ 529 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 530 size = i2c_hid_get_report_length(report); 531 if (*max < size) 532 *max = size; 533 } 534 } 535 536 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 537 { 538 kfree(ihid->inbuf); 539 kfree(ihid->rawbuf); 540 kfree(ihid->argsbuf); 541 kfree(ihid->cmdbuf); 542 ihid->inbuf = NULL; 543 ihid->rawbuf = NULL; 544 ihid->cmdbuf = NULL; 545 ihid->argsbuf = NULL; 546 ihid->bufsize = 0; 547 } 548 549 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 550 { 551 /* the worst case is computed from the set_report command with a 552 * reportID > 15 and the maximum report length */ 553 int args_len = sizeof(__u8) + /* ReportID */ 554 sizeof(__u8) + /* optional ReportID byte */ 555 sizeof(__u16) + /* data register */ 556 sizeof(__u16) + /* size of the report */ 557 report_size; /* report */ 558 559 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 560 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 561 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL); 562 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL); 563 564 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) { 565 i2c_hid_free_buffers(ihid); 566 return -ENOMEM; 567 } 568 569 ihid->bufsize = report_size; 570 571 return 0; 572 } 573 574 static int i2c_hid_get_raw_report(struct hid_device *hid, 575 unsigned char report_number, __u8 *buf, size_t count, 576 unsigned char report_type) 577 { 578 struct i2c_client *client = hid->driver_data; 579 struct i2c_hid *ihid = i2c_get_clientdata(client); 580 size_t ret_count, ask_count; 581 int ret; 582 583 if (report_type == HID_OUTPUT_REPORT) 584 return -EINVAL; 585 586 /* +2 bytes to include the size of the reply in the query buffer */ 587 ask_count = min(count + 2, (size_t)ihid->bufsize); 588 589 ret = i2c_hid_get_report(client, 590 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 591 report_number, ihid->rawbuf, ask_count); 592 593 if (ret < 0) 594 return ret; 595 596 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8); 597 598 if (ret_count <= 2) 599 return 0; 600 601 ret_count = min(ret_count, ask_count); 602 603 /* The query buffer contains the size, dropping it in the reply */ 604 count = min(count, ret_count - 2); 605 memcpy(buf, ihid->rawbuf + 2, count); 606 607 return count; 608 } 609 610 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, 611 size_t count, unsigned char report_type, bool use_data) 612 { 613 struct i2c_client *client = hid->driver_data; 614 struct i2c_hid *ihid = i2c_get_clientdata(client); 615 int report_id = buf[0]; 616 int ret; 617 618 if (report_type == HID_INPUT_REPORT) 619 return -EINVAL; 620 621 mutex_lock(&ihid->reset_lock); 622 623 if (report_id) { 624 buf++; 625 count--; 626 } 627 628 ret = i2c_hid_set_or_send_report(client, 629 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 630 report_id, buf, count, use_data); 631 632 if (report_id && ret >= 0) 633 ret++; /* add report_id to the number of transfered bytes */ 634 635 mutex_unlock(&ihid->reset_lock); 636 637 return ret; 638 } 639 640 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf, 641 size_t count) 642 { 643 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT, 644 false); 645 } 646 647 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 648 __u8 *buf, size_t len, unsigned char rtype, 649 int reqtype) 650 { 651 switch (reqtype) { 652 case HID_REQ_GET_REPORT: 653 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype); 654 case HID_REQ_SET_REPORT: 655 if (buf[0] != reportnum) 656 return -EINVAL; 657 return i2c_hid_output_raw_report(hid, buf, len, rtype, true); 658 default: 659 return -EIO; 660 } 661 } 662 663 static int i2c_hid_parse(struct hid_device *hid) 664 { 665 struct i2c_client *client = hid->driver_data; 666 struct i2c_hid *ihid = i2c_get_clientdata(client); 667 struct i2c_hid_desc *hdesc = &ihid->hdesc; 668 unsigned int rsize; 669 char *rdesc; 670 int ret; 671 int tries = 3; 672 char *use_override; 673 674 i2c_hid_dbg(ihid, "entering %s\n", __func__); 675 676 rsize = le16_to_cpu(hdesc->wReportDescLength); 677 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 678 dbg_hid("weird size of report descriptor (%u)\n", rsize); 679 return -EINVAL; 680 } 681 682 do { 683 ret = i2c_hid_hwreset(client); 684 if (ret) 685 msleep(1000); 686 } while (tries-- > 0 && ret); 687 688 if (ret) 689 return ret; 690 691 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 692 &rsize); 693 694 if (use_override) { 695 rdesc = use_override; 696 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 697 } else { 698 rdesc = kzalloc(rsize, GFP_KERNEL); 699 700 if (!rdesc) { 701 dbg_hid("couldn't allocate rdesc memory\n"); 702 return -ENOMEM; 703 } 704 705 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 706 707 ret = i2c_hid_command(client, &hid_report_descr_cmd, 708 rdesc, rsize); 709 if (ret) { 710 hid_err(hid, "reading report descriptor failed\n"); 711 kfree(rdesc); 712 return -EIO; 713 } 714 } 715 716 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 717 718 ret = hid_parse_report(hid, rdesc, rsize); 719 if (!use_override) 720 kfree(rdesc); 721 722 if (ret) { 723 dbg_hid("parsing report descriptor failed\n"); 724 return ret; 725 } 726 727 return 0; 728 } 729 730 static int i2c_hid_start(struct hid_device *hid) 731 { 732 struct i2c_client *client = hid->driver_data; 733 struct i2c_hid *ihid = i2c_get_clientdata(client); 734 int ret; 735 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 736 737 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 738 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 739 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 740 741 if (bufsize > ihid->bufsize) { 742 disable_irq(client->irq); 743 i2c_hid_free_buffers(ihid); 744 745 ret = i2c_hid_alloc_buffers(ihid, bufsize); 746 enable_irq(client->irq); 747 748 if (ret) 749 return ret; 750 } 751 752 return 0; 753 } 754 755 static void i2c_hid_stop(struct hid_device *hid) 756 { 757 hid->claimed = 0; 758 } 759 760 static int i2c_hid_open(struct hid_device *hid) 761 { 762 struct i2c_client *client = hid->driver_data; 763 struct i2c_hid *ihid = i2c_get_clientdata(client); 764 int ret = 0; 765 766 ret = pm_runtime_get_sync(&client->dev); 767 if (ret < 0) 768 return ret; 769 770 set_bit(I2C_HID_STARTED, &ihid->flags); 771 return 0; 772 } 773 774 static void i2c_hid_close(struct hid_device *hid) 775 { 776 struct i2c_client *client = hid->driver_data; 777 struct i2c_hid *ihid = i2c_get_clientdata(client); 778 779 clear_bit(I2C_HID_STARTED, &ihid->flags); 780 781 /* Save some power */ 782 pm_runtime_put(&client->dev); 783 } 784 785 static int i2c_hid_power(struct hid_device *hid, int lvl) 786 { 787 struct i2c_client *client = hid->driver_data; 788 struct i2c_hid *ihid = i2c_get_clientdata(client); 789 790 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl); 791 792 switch (lvl) { 793 case PM_HINT_FULLON: 794 pm_runtime_get_sync(&client->dev); 795 break; 796 case PM_HINT_NORMAL: 797 pm_runtime_put(&client->dev); 798 break; 799 } 800 return 0; 801 } 802 803 struct hid_ll_driver i2c_hid_ll_driver = { 804 .parse = i2c_hid_parse, 805 .start = i2c_hid_start, 806 .stop = i2c_hid_stop, 807 .open = i2c_hid_open, 808 .close = i2c_hid_close, 809 .power = i2c_hid_power, 810 .output_report = i2c_hid_output_report, 811 .raw_request = i2c_hid_raw_request, 812 }; 813 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); 814 815 static int i2c_hid_init_irq(struct i2c_client *client) 816 { 817 struct i2c_hid *ihid = i2c_get_clientdata(client); 818 unsigned long irqflags = 0; 819 int ret; 820 821 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); 822 823 if (!irq_get_trigger_type(client->irq)) 824 irqflags = IRQF_TRIGGER_LOW; 825 826 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 827 irqflags | IRQF_ONESHOT, client->name, ihid); 828 if (ret < 0) { 829 dev_warn(&client->dev, 830 "Could not register for %s interrupt, irq = %d," 831 " ret = %d\n", 832 client->name, client->irq, ret); 833 834 return ret; 835 } 836 837 return 0; 838 } 839 840 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 841 { 842 struct i2c_client *client = ihid->client; 843 struct i2c_hid_desc *hdesc = &ihid->hdesc; 844 unsigned int dsize; 845 int ret; 846 847 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 848 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 849 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 850 ihid->hdesc = 851 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 852 } else { 853 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 854 ret = i2c_hid_command(client, &hid_descr_cmd, 855 ihid->hdesc_buffer, 856 sizeof(struct i2c_hid_desc)); 857 if (ret) { 858 dev_err(&client->dev, "hid_descr_cmd failed\n"); 859 return -ENODEV; 860 } 861 } 862 863 /* Validate the length of HID descriptor, the 4 first bytes: 864 * bytes 0-1 -> length 865 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 866 /* check bcdVersion == 1.0 */ 867 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 868 dev_err(&client->dev, 869 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 870 le16_to_cpu(hdesc->bcdVersion)); 871 return -ENODEV; 872 } 873 874 /* Descriptor length should be 30 bytes as per the specification */ 875 dsize = le16_to_cpu(hdesc->wHIDDescLength); 876 if (dsize != sizeof(struct i2c_hid_desc)) { 877 dev_err(&client->dev, "weird size of HID descriptor (%u)\n", 878 dsize); 879 return -ENODEV; 880 } 881 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); 882 return 0; 883 } 884 885 #ifdef CONFIG_ACPI 886 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { 887 /* 888 * The CHPN0001 ACPI device, which is used to describe the Chipone 889 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. 890 */ 891 {"CHPN0001", 0 }, 892 { }, 893 }; 894 895 static int i2c_hid_acpi_pdata(struct i2c_client *client, 896 struct i2c_hid_platform_data *pdata) 897 { 898 static guid_t i2c_hid_guid = 899 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 900 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); 901 union acpi_object *obj; 902 struct acpi_device *adev; 903 acpi_handle handle; 904 905 handle = ACPI_HANDLE(&client->dev); 906 if (!handle || acpi_bus_get_device(handle, &adev)) { 907 dev_err(&client->dev, "Error could not get ACPI device\n"); 908 return -ENODEV; 909 } 910 911 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 912 return -ENODEV; 913 914 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 915 ACPI_TYPE_INTEGER); 916 if (!obj) { 917 dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n"); 918 return -ENODEV; 919 } 920 921 pdata->hid_descriptor_address = obj->integer.value; 922 ACPI_FREE(obj); 923 924 return 0; 925 } 926 927 static void i2c_hid_acpi_fix_up_power(struct device *dev) 928 { 929 struct acpi_device *adev; 930 931 adev = ACPI_COMPANION(dev); 932 if (adev) 933 acpi_device_fix_up_power(adev); 934 } 935 936 static const struct acpi_device_id i2c_hid_acpi_match[] = { 937 {"ACPI0C50", 0 }, 938 {"PNP0C50", 0 }, 939 { }, 940 }; 941 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 942 #else 943 static inline int i2c_hid_acpi_pdata(struct i2c_client *client, 944 struct i2c_hid_platform_data *pdata) 945 { 946 return -ENODEV; 947 } 948 949 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} 950 #endif 951 952 #ifdef CONFIG_OF 953 static int i2c_hid_of_probe(struct i2c_client *client, 954 struct i2c_hid_platform_data *pdata) 955 { 956 struct device *dev = &client->dev; 957 u32 val; 958 int ret; 959 960 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); 961 if (ret) { 962 dev_err(&client->dev, "HID register address not provided\n"); 963 return -ENODEV; 964 } 965 if (val >> 16) { 966 dev_err(&client->dev, "Bad HID register address: 0x%08x\n", 967 val); 968 return -EINVAL; 969 } 970 pdata->hid_descriptor_address = val; 971 972 return 0; 973 } 974 975 static const struct of_device_id i2c_hid_of_match[] = { 976 { .compatible = "hid-over-i2c" }, 977 {}, 978 }; 979 MODULE_DEVICE_TABLE(of, i2c_hid_of_match); 980 #else 981 static inline int i2c_hid_of_probe(struct i2c_client *client, 982 struct i2c_hid_platform_data *pdata) 983 { 984 return -ENODEV; 985 } 986 #endif 987 988 static void i2c_hid_fwnode_probe(struct i2c_client *client, 989 struct i2c_hid_platform_data *pdata) 990 { 991 u32 val; 992 993 if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms", 994 &val)) 995 pdata->post_power_delay_ms = val; 996 } 997 998 static int i2c_hid_probe(struct i2c_client *client, 999 const struct i2c_device_id *dev_id) 1000 { 1001 int ret; 1002 struct i2c_hid *ihid; 1003 struct hid_device *hid; 1004 __u16 hidRegister; 1005 struct i2c_hid_platform_data *platform_data = client->dev.platform_data; 1006 1007 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 1008 1009 if (!client->irq) { 1010 dev_err(&client->dev, 1011 "HID over i2c has not been provided an Int IRQ\n"); 1012 return -EINVAL; 1013 } 1014 1015 if (client->irq < 0) { 1016 if (client->irq != -EPROBE_DEFER) 1017 dev_err(&client->dev, 1018 "HID over i2c doesn't have a valid IRQ\n"); 1019 return client->irq; 1020 } 1021 1022 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1023 if (!ihid) 1024 return -ENOMEM; 1025 1026 if (client->dev.of_node) { 1027 ret = i2c_hid_of_probe(client, &ihid->pdata); 1028 if (ret) 1029 return ret; 1030 } else if (!platform_data) { 1031 ret = i2c_hid_acpi_pdata(client, &ihid->pdata); 1032 if (ret) 1033 return ret; 1034 } else { 1035 ihid->pdata = *platform_data; 1036 } 1037 1038 /* Parse platform agnostic common properties from ACPI / device tree */ 1039 i2c_hid_fwnode_probe(client, &ihid->pdata); 1040 1041 ihid->pdata.supplies[0].supply = "vdd"; 1042 ihid->pdata.supplies[1].supply = "vddl"; 1043 1044 ret = devm_regulator_bulk_get(&client->dev, 1045 ARRAY_SIZE(ihid->pdata.supplies), 1046 ihid->pdata.supplies); 1047 if (ret) 1048 return ret; 1049 1050 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1051 ihid->pdata.supplies); 1052 if (ret < 0) 1053 return ret; 1054 1055 if (ihid->pdata.post_power_delay_ms) 1056 msleep(ihid->pdata.post_power_delay_ms); 1057 1058 i2c_set_clientdata(client, ihid); 1059 1060 ihid->client = client; 1061 1062 hidRegister = ihid->pdata.hid_descriptor_address; 1063 ihid->wHIDDescRegister = cpu_to_le16(hidRegister); 1064 1065 init_waitqueue_head(&ihid->wait); 1066 mutex_init(&ihid->reset_lock); 1067 1068 /* we need to allocate the command buffer without knowing the maximum 1069 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1070 * real computation later. */ 1071 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1072 if (ret < 0) 1073 goto err_regulator; 1074 1075 i2c_hid_acpi_fix_up_power(&client->dev); 1076 1077 pm_runtime_get_noresume(&client->dev); 1078 pm_runtime_set_active(&client->dev); 1079 pm_runtime_enable(&client->dev); 1080 device_enable_async_suspend(&client->dev); 1081 1082 /* Make sure there is something at this address */ 1083 ret = i2c_smbus_read_byte(client); 1084 if (ret < 0) { 1085 dev_dbg(&client->dev, "nothing at this address: %d\n", ret); 1086 ret = -ENXIO; 1087 goto err_pm; 1088 } 1089 1090 ret = i2c_hid_fetch_hid_descriptor(ihid); 1091 if (ret < 0) 1092 goto err_pm; 1093 1094 ret = i2c_hid_init_irq(client); 1095 if (ret < 0) 1096 goto err_pm; 1097 1098 hid = hid_allocate_device(); 1099 if (IS_ERR(hid)) { 1100 ret = PTR_ERR(hid); 1101 goto err_irq; 1102 } 1103 1104 ihid->hid = hid; 1105 1106 hid->driver_data = client; 1107 hid->ll_driver = &i2c_hid_ll_driver; 1108 hid->dev.parent = &client->dev; 1109 hid->bus = BUS_I2C; 1110 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1111 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1112 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1113 1114 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX", 1115 client->name, hid->vendor, hid->product); 1116 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1117 1118 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1119 1120 ret = hid_add_device(hid); 1121 if (ret) { 1122 if (ret != -ENODEV) 1123 hid_err(client, "can't add hid device: %d\n", ret); 1124 goto err_mem_free; 1125 } 1126 1127 if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM)) 1128 pm_runtime_put(&client->dev); 1129 1130 return 0; 1131 1132 err_mem_free: 1133 hid_destroy_device(hid); 1134 1135 err_irq: 1136 free_irq(client->irq, ihid); 1137 1138 err_pm: 1139 pm_runtime_put_noidle(&client->dev); 1140 pm_runtime_disable(&client->dev); 1141 1142 err_regulator: 1143 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1144 ihid->pdata.supplies); 1145 i2c_hid_free_buffers(ihid); 1146 return ret; 1147 } 1148 1149 static int i2c_hid_remove(struct i2c_client *client) 1150 { 1151 struct i2c_hid *ihid = i2c_get_clientdata(client); 1152 struct hid_device *hid; 1153 1154 if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM)) 1155 pm_runtime_get_sync(&client->dev); 1156 pm_runtime_disable(&client->dev); 1157 pm_runtime_set_suspended(&client->dev); 1158 pm_runtime_put_noidle(&client->dev); 1159 1160 hid = ihid->hid; 1161 hid_destroy_device(hid); 1162 1163 free_irq(client->irq, ihid); 1164 1165 if (ihid->bufsize) 1166 i2c_hid_free_buffers(ihid); 1167 1168 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1169 ihid->pdata.supplies); 1170 1171 return 0; 1172 } 1173 1174 static void i2c_hid_shutdown(struct i2c_client *client) 1175 { 1176 struct i2c_hid *ihid = i2c_get_clientdata(client); 1177 1178 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1179 free_irq(client->irq, ihid); 1180 } 1181 1182 #ifdef CONFIG_PM_SLEEP 1183 static int i2c_hid_suspend(struct device *dev) 1184 { 1185 struct i2c_client *client = to_i2c_client(dev); 1186 struct i2c_hid *ihid = i2c_get_clientdata(client); 1187 struct hid_device *hid = ihid->hid; 1188 int ret; 1189 int wake_status; 1190 1191 if (hid->driver && hid->driver->suspend) { 1192 /* 1193 * Wake up the device so that IO issues in 1194 * HID driver's suspend code can succeed. 1195 */ 1196 ret = pm_runtime_resume(dev); 1197 if (ret < 0) 1198 return ret; 1199 1200 ret = hid->driver->suspend(hid, PMSG_SUSPEND); 1201 if (ret < 0) 1202 return ret; 1203 } 1204 1205 if (!pm_runtime_suspended(dev)) { 1206 /* Save some power */ 1207 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1208 1209 disable_irq(client->irq); 1210 } 1211 1212 if (device_may_wakeup(&client->dev)) { 1213 wake_status = enable_irq_wake(client->irq); 1214 if (!wake_status) 1215 ihid->irq_wake_enabled = true; 1216 else 1217 hid_warn(hid, "Failed to enable irq wake: %d\n", 1218 wake_status); 1219 } else { 1220 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1221 ihid->pdata.supplies); 1222 } 1223 1224 return 0; 1225 } 1226 1227 static int i2c_hid_resume(struct device *dev) 1228 { 1229 int ret; 1230 struct i2c_client *client = to_i2c_client(dev); 1231 struct i2c_hid *ihid = i2c_get_clientdata(client); 1232 struct hid_device *hid = ihid->hid; 1233 int wake_status; 1234 1235 if (!device_may_wakeup(&client->dev)) { 1236 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1237 ihid->pdata.supplies); 1238 if (ret) 1239 hid_warn(hid, "Failed to enable supplies: %d\n", ret); 1240 1241 if (ihid->pdata.post_power_delay_ms) 1242 msleep(ihid->pdata.post_power_delay_ms); 1243 } else if (ihid->irq_wake_enabled) { 1244 wake_status = disable_irq_wake(client->irq); 1245 if (!wake_status) 1246 ihid->irq_wake_enabled = false; 1247 else 1248 hid_warn(hid, "Failed to disable irq wake: %d\n", 1249 wake_status); 1250 } 1251 1252 /* We'll resume to full power */ 1253 pm_runtime_disable(dev); 1254 pm_runtime_set_active(dev); 1255 pm_runtime_enable(dev); 1256 1257 enable_irq(client->irq); 1258 1259 /* Instead of resetting device, simply powers the device on. This 1260 * solves "incomplete reports" on Raydium devices 2386:3118 and 1261 * 2386:4B33 and fixes various SIS touchscreens no longer sending 1262 * data after a suspend/resume. 1263 */ 1264 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 1265 if (ret) 1266 return ret; 1267 1268 if (hid->driver && hid->driver->reset_resume) { 1269 ret = hid->driver->reset_resume(hid); 1270 return ret; 1271 } 1272 1273 return 0; 1274 } 1275 #endif 1276 1277 #ifdef CONFIG_PM 1278 static int i2c_hid_runtime_suspend(struct device *dev) 1279 { 1280 struct i2c_client *client = to_i2c_client(dev); 1281 1282 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1283 disable_irq(client->irq); 1284 return 0; 1285 } 1286 1287 static int i2c_hid_runtime_resume(struct device *dev) 1288 { 1289 struct i2c_client *client = to_i2c_client(dev); 1290 1291 enable_irq(client->irq); 1292 i2c_hid_set_power(client, I2C_HID_PWR_ON); 1293 return 0; 1294 } 1295 #endif 1296 1297 static const struct dev_pm_ops i2c_hid_pm = { 1298 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume) 1299 SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume, 1300 NULL) 1301 }; 1302 1303 static const struct i2c_device_id i2c_hid_id_table[] = { 1304 { "hid", 0 }, 1305 { "hid-over-i2c", 0 }, 1306 { }, 1307 }; 1308 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); 1309 1310 1311 static struct i2c_driver i2c_hid_driver = { 1312 .driver = { 1313 .name = "i2c_hid", 1314 .pm = &i2c_hid_pm, 1315 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), 1316 .of_match_table = of_match_ptr(i2c_hid_of_match), 1317 }, 1318 1319 .probe = i2c_hid_probe, 1320 .remove = i2c_hid_remove, 1321 .shutdown = i2c_hid_shutdown, 1322 .id_table = i2c_hid_id_table, 1323 }; 1324 1325 module_i2c_driver(i2c_hid_driver); 1326 1327 MODULE_DESCRIPTION("HID over I2C core driver"); 1328 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1329 MODULE_LICENSE("GPL"); 1330