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 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(5) 52 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(6) 53 54 55 /* flags */ 56 #define I2C_HID_STARTED 0 57 #define I2C_HID_RESET_PENDING 1 58 #define I2C_HID_READ_PENDING 2 59 60 #define I2C_HID_PWR_ON 0x00 61 #define I2C_HID_PWR_SLEEP 0x01 62 63 /* debug option */ 64 static bool debug; 65 module_param(debug, bool, 0444); 66 MODULE_PARM_DESC(debug, "print a lot of debug information"); 67 68 #define i2c_hid_dbg(ihid, fmt, arg...) \ 69 do { \ 70 if (debug) \ 71 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \ 72 } while (0) 73 74 struct i2c_hid_desc { 75 __le16 wHIDDescLength; 76 __le16 bcdVersion; 77 __le16 wReportDescLength; 78 __le16 wReportDescRegister; 79 __le16 wInputRegister; 80 __le16 wMaxInputLength; 81 __le16 wOutputRegister; 82 __le16 wMaxOutputLength; 83 __le16 wCommandRegister; 84 __le16 wDataRegister; 85 __le16 wVendorID; 86 __le16 wProductID; 87 __le16 wVersionID; 88 __le32 reserved; 89 } __packed; 90 91 struct i2c_hid_cmd { 92 unsigned int registerIndex; 93 __u8 opcode; 94 unsigned int length; 95 bool wait; 96 }; 97 98 union command { 99 u8 data[0]; 100 struct cmd { 101 __le16 reg; 102 __u8 reportTypeID; 103 __u8 opcode; 104 } __packed c; 105 }; 106 107 #define I2C_HID_CMD(opcode_) \ 108 .opcode = opcode_, .length = 4, \ 109 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister) 110 111 /* fetch HID descriptor */ 112 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 }; 113 /* fetch report descriptors */ 114 static const struct i2c_hid_cmd hid_report_descr_cmd = { 115 .registerIndex = offsetof(struct i2c_hid_desc, 116 wReportDescRegister), 117 .opcode = 0x00, 118 .length = 2 }; 119 /* commands */ 120 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01), 121 .wait = true }; 122 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) }; 123 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) }; 124 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) }; 125 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 }; 126 127 /* 128 * These definitions are not used here, but are defined by the spec. 129 * Keeping them here for documentation purposes. 130 * 131 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) }; 132 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) }; 133 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) }; 134 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) }; 135 */ 136 137 /* The main device structure */ 138 struct i2c_hid { 139 struct i2c_client *client; /* i2c client */ 140 struct hid_device *hid; /* pointer to corresponding HID dev */ 141 union { 142 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)]; 143 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 144 }; 145 __le16 wHIDDescRegister; /* location of the i2c 146 * register of the HID 147 * descriptor. */ 148 unsigned int bufsize; /* i2c buffer size */ 149 u8 *inbuf; /* Input buffer */ 150 u8 *rawbuf; /* Raw Input buffer */ 151 u8 *cmdbuf; /* Command buffer */ 152 u8 *argsbuf; /* Command arguments buffer */ 153 154 unsigned long flags; /* device flags */ 155 unsigned long quirks; /* Various quirks */ 156 157 wait_queue_head_t wait; /* For waiting the interrupt */ 158 159 struct i2c_hid_platform_data pdata; 160 161 bool irq_wake_enabled; 162 struct mutex reset_lock; 163 }; 164 165 static const struct i2c_hid_quirks { 166 __u16 idVendor; 167 __u16 idProduct; 168 __u32 quirks; 169 } i2c_hid_quirks[] = { 170 { USB_VENDOR_ID_WEIDA, HID_ANY_ID, 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_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118, 175 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 176 { USB_VENDOR_ID_ELAN, HID_ANY_ID, 177 I2C_HID_QUIRK_BOGUS_IRQ }, 178 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID, 179 I2C_HID_QUIRK_RESET_ON_RESUME }, 180 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393, 181 I2C_HID_QUIRK_RESET_ON_RESUME }, 182 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720, 183 I2C_HID_QUIRK_BAD_INPUT_SIZE }, 184 { 0, 0 } 185 }; 186 187 /* 188 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device 189 * @idVendor: the 16-bit vendor ID 190 * @idProduct: the 16-bit product ID 191 * 192 * Returns: a u32 quirks value. 193 */ 194 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) 195 { 196 u32 quirks = 0; 197 int n; 198 199 for (n = 0; i2c_hid_quirks[n].idVendor; n++) 200 if (i2c_hid_quirks[n].idVendor == idVendor && 201 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || 202 i2c_hid_quirks[n].idProduct == idProduct)) 203 quirks = i2c_hid_quirks[n].quirks; 204 205 return quirks; 206 } 207 208 static int __i2c_hid_command(struct i2c_client *client, 209 const struct i2c_hid_cmd *command, u8 reportID, 210 u8 reportType, u8 *args, int args_len, 211 unsigned char *buf_recv, int data_len) 212 { 213 struct i2c_hid *ihid = i2c_get_clientdata(client); 214 union command *cmd = (union command *)ihid->cmdbuf; 215 int ret; 216 struct i2c_msg msg[2]; 217 int msg_num = 1; 218 219 int length = command->length; 220 bool wait = command->wait; 221 unsigned int registerIndex = command->registerIndex; 222 223 /* special case for hid_descr_cmd */ 224 if (command == &hid_descr_cmd) { 225 cmd->c.reg = ihid->wHIDDescRegister; 226 } else { 227 cmd->data[0] = ihid->hdesc_buffer[registerIndex]; 228 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1]; 229 } 230 231 if (length > 2) { 232 cmd->c.opcode = command->opcode; 233 cmd->c.reportTypeID = reportID | reportType << 4; 234 } 235 236 memcpy(cmd->data + length, args, args_len); 237 length += args_len; 238 239 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data); 240 241 msg[0].addr = client->addr; 242 msg[0].flags = client->flags & I2C_M_TEN; 243 msg[0].len = length; 244 msg[0].buf = cmd->data; 245 if (data_len > 0) { 246 msg[1].addr = client->addr; 247 msg[1].flags = client->flags & I2C_M_TEN; 248 msg[1].flags |= I2C_M_RD; 249 msg[1].len = data_len; 250 msg[1].buf = buf_recv; 251 msg_num = 2; 252 set_bit(I2C_HID_READ_PENDING, &ihid->flags); 253 } 254 255 if (wait) 256 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 257 258 ret = i2c_transfer(client->adapter, msg, msg_num); 259 260 if (data_len > 0) 261 clear_bit(I2C_HID_READ_PENDING, &ihid->flags); 262 263 if (ret != msg_num) 264 return ret < 0 ? ret : -EIO; 265 266 ret = 0; 267 268 if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) { 269 msleep(100); 270 } else if (wait) { 271 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 272 if (!wait_event_timeout(ihid->wait, 273 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 274 msecs_to_jiffies(5000))) 275 ret = -ENODATA; 276 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 277 } 278 279 return ret; 280 } 281 282 static int i2c_hid_command(struct i2c_client *client, 283 const struct i2c_hid_cmd *command, 284 unsigned char *buf_recv, int data_len) 285 { 286 return __i2c_hid_command(client, command, 0, 0, NULL, 0, 287 buf_recv, data_len); 288 } 289 290 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType, 291 u8 reportID, unsigned char *buf_recv, int data_len) 292 { 293 struct i2c_hid *ihid = i2c_get_clientdata(client); 294 u8 args[3]; 295 int ret; 296 int args_len = 0; 297 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister); 298 299 i2c_hid_dbg(ihid, "%s\n", __func__); 300 301 if (reportID >= 0x0F) { 302 args[args_len++] = reportID; 303 reportID = 0x0F; 304 } 305 306 args[args_len++] = readRegister & 0xFF; 307 args[args_len++] = readRegister >> 8; 308 309 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID, 310 reportType, args, args_len, buf_recv, data_len); 311 if (ret) { 312 dev_err(&client->dev, 313 "failed to retrieve report from device.\n"); 314 return ret; 315 } 316 317 return 0; 318 } 319 320 /** 321 * i2c_hid_set_or_send_report: forward an incoming report to the device 322 * @client: the i2c_client of the device 323 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 324 * @reportID: the report ID 325 * @buf: the actual data to transfer, without the report ID 326 * @len: size of buf 327 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report 328 */ 329 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType, 330 u8 reportID, unsigned char *buf, size_t data_len, bool use_data) 331 { 332 struct i2c_hid *ihid = i2c_get_clientdata(client); 333 u8 *args = ihid->argsbuf; 334 const struct i2c_hid_cmd *hidcmd; 335 int ret; 336 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister); 337 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister); 338 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength); 339 u16 size; 340 int args_len; 341 int index = 0; 342 343 i2c_hid_dbg(ihid, "%s\n", __func__); 344 345 if (data_len > ihid->bufsize) 346 return -EINVAL; 347 348 size = 2 /* size */ + 349 (reportID ? 1 : 0) /* reportID */ + 350 data_len /* buf */; 351 args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ + 352 2 /* dataRegister */ + 353 size /* args */; 354 355 if (!use_data && maxOutputLength == 0) 356 return -ENOSYS; 357 358 if (reportID >= 0x0F) { 359 args[index++] = reportID; 360 reportID = 0x0F; 361 } 362 363 /* 364 * use the data register for feature reports or if the device does not 365 * support the output register 366 */ 367 if (use_data) { 368 args[index++] = dataRegister & 0xFF; 369 args[index++] = dataRegister >> 8; 370 hidcmd = &hid_set_report_cmd; 371 } else { 372 args[index++] = outputRegister & 0xFF; 373 args[index++] = outputRegister >> 8; 374 hidcmd = &hid_no_cmd; 375 } 376 377 args[index++] = size & 0xFF; 378 args[index++] = size >> 8; 379 380 if (reportID) 381 args[index++] = reportID; 382 383 memcpy(&args[index], buf, data_len); 384 385 ret = __i2c_hid_command(client, hidcmd, reportID, 386 reportType, args, args_len, NULL, 0); 387 if (ret) { 388 dev_err(&client->dev, "failed to set a report to device.\n"); 389 return ret; 390 } 391 392 return data_len; 393 } 394 395 static int i2c_hid_set_power(struct i2c_client *client, int power_state) 396 { 397 struct i2c_hid *ihid = i2c_get_clientdata(client); 398 int ret; 399 400 i2c_hid_dbg(ihid, "%s\n", __func__); 401 402 /* 403 * Some devices require to send a command to wakeup before power on. 404 * The call will get a return value (EREMOTEIO) but device will be 405 * triggered and activated. After that, it goes like a normal device. 406 */ 407 if (power_state == I2C_HID_PWR_ON && 408 ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) { 409 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0); 410 411 /* Device was already activated */ 412 if (!ret) 413 goto set_pwr_exit; 414 } 415 416 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state, 417 0, NULL, 0, NULL, 0); 418 419 if (ret) 420 dev_err(&client->dev, "failed to change power setting.\n"); 421 422 set_pwr_exit: 423 return ret; 424 } 425 426 static int i2c_hid_hwreset(struct i2c_client *client) 427 { 428 struct i2c_hid *ihid = i2c_get_clientdata(client); 429 int ret; 430 431 i2c_hid_dbg(ihid, "%s\n", __func__); 432 433 /* 434 * This prevents sending feature reports while the device is 435 * being reset. Otherwise we may lose the reset complete 436 * interrupt. 437 */ 438 mutex_lock(&ihid->reset_lock); 439 440 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 441 if (ret) 442 goto out_unlock; 443 444 /* 445 * The HID over I2C specification states that if a DEVICE needs time 446 * after the PWR_ON request, it should utilise CLOCK stretching. 447 * However, it has been observered that the Windows driver provides a 448 * 1ms sleep between the PWR_ON and RESET requests and that some devices 449 * rely on this. 450 */ 451 usleep_range(1000, 5000); 452 453 i2c_hid_dbg(ihid, "resetting...\n"); 454 455 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0); 456 if (ret) { 457 dev_err(&client->dev, "failed to reset device.\n"); 458 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 459 goto out_unlock; 460 } 461 462 /* At least some SIS devices need this after reset */ 463 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 464 465 out_unlock: 466 mutex_unlock(&ihid->reset_lock); 467 return ret; 468 } 469 470 static void i2c_hid_get_input(struct i2c_hid *ihid) 471 { 472 int ret; 473 u32 ret_size; 474 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 475 476 if (size > ihid->bufsize) 477 size = ihid->bufsize; 478 479 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 480 if (ret != size) { 481 if (ret < 0) 482 return; 483 484 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 485 __func__, ret, size); 486 return; 487 } 488 489 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8; 490 491 if (!ret_size) { 492 /* host or device initiated RESET completed */ 493 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 494 wake_up(&ihid->wait); 495 return; 496 } 497 498 if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) { 499 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but " 500 "there's no data\n", __func__); 501 return; 502 } 503 504 if ((ret_size > size) || (ret_size < 2)) { 505 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) { 506 ihid->inbuf[0] = size & 0xff; 507 ihid->inbuf[1] = size >> 8; 508 ret_size = size; 509 } else { 510 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n", 511 __func__, size, ret_size); 512 return; 513 } 514 } 515 516 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 517 518 if (test_bit(I2C_HID_STARTED, &ihid->flags)) 519 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2, 520 ret_size - 2, 1); 521 522 return; 523 } 524 525 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 526 { 527 struct i2c_hid *ihid = dev_id; 528 529 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) 530 return IRQ_HANDLED; 531 532 i2c_hid_get_input(ihid); 533 534 return IRQ_HANDLED; 535 } 536 537 static int i2c_hid_get_report_length(struct hid_report *report) 538 { 539 return ((report->size - 1) >> 3) + 1 + 540 report->device->report_enum[report->type].numbered + 2; 541 } 542 543 /* 544 * Traverse the supplied list of reports and find the longest 545 */ 546 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 547 unsigned int *max) 548 { 549 struct hid_report *report; 550 unsigned int size; 551 552 /* We should not rely on wMaxInputLength, as some devices may set it to 553 * a wrong length. */ 554 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 555 size = i2c_hid_get_report_length(report); 556 if (*max < size) 557 *max = size; 558 } 559 } 560 561 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 562 { 563 kfree(ihid->inbuf); 564 kfree(ihid->rawbuf); 565 kfree(ihid->argsbuf); 566 kfree(ihid->cmdbuf); 567 ihid->inbuf = NULL; 568 ihid->rawbuf = NULL; 569 ihid->cmdbuf = NULL; 570 ihid->argsbuf = NULL; 571 ihid->bufsize = 0; 572 } 573 574 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 575 { 576 /* the worst case is computed from the set_report command with a 577 * reportID > 15 and the maximum report length */ 578 int args_len = sizeof(__u8) + /* ReportID */ 579 sizeof(__u8) + /* optional ReportID byte */ 580 sizeof(__u16) + /* data register */ 581 sizeof(__u16) + /* size of the report */ 582 report_size; /* report */ 583 584 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 585 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 586 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL); 587 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL); 588 589 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) { 590 i2c_hid_free_buffers(ihid); 591 return -ENOMEM; 592 } 593 594 ihid->bufsize = report_size; 595 596 return 0; 597 } 598 599 static int i2c_hid_get_raw_report(struct hid_device *hid, 600 unsigned char report_number, __u8 *buf, size_t count, 601 unsigned char report_type) 602 { 603 struct i2c_client *client = hid->driver_data; 604 struct i2c_hid *ihid = i2c_get_clientdata(client); 605 size_t ret_count, ask_count; 606 int ret; 607 608 if (report_type == HID_OUTPUT_REPORT) 609 return -EINVAL; 610 611 /* +2 bytes to include the size of the reply in the query buffer */ 612 ask_count = min(count + 2, (size_t)ihid->bufsize); 613 614 ret = i2c_hid_get_report(client, 615 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 616 report_number, ihid->rawbuf, ask_count); 617 618 if (ret < 0) 619 return ret; 620 621 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8); 622 623 if (ret_count <= 2) 624 return 0; 625 626 ret_count = min(ret_count, ask_count); 627 628 /* The query buffer contains the size, dropping it in the reply */ 629 count = min(count, ret_count - 2); 630 memcpy(buf, ihid->rawbuf + 2, count); 631 632 return count; 633 } 634 635 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, 636 size_t count, unsigned char report_type, bool use_data) 637 { 638 struct i2c_client *client = hid->driver_data; 639 struct i2c_hid *ihid = i2c_get_clientdata(client); 640 int report_id = buf[0]; 641 int ret; 642 643 if (report_type == HID_INPUT_REPORT) 644 return -EINVAL; 645 646 mutex_lock(&ihid->reset_lock); 647 648 if (report_id) { 649 buf++; 650 count--; 651 } 652 653 ret = i2c_hid_set_or_send_report(client, 654 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 655 report_id, buf, count, use_data); 656 657 if (report_id && ret >= 0) 658 ret++; /* add report_id to the number of transfered bytes */ 659 660 mutex_unlock(&ihid->reset_lock); 661 662 return ret; 663 } 664 665 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf, 666 size_t count) 667 { 668 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT, 669 false); 670 } 671 672 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 673 __u8 *buf, size_t len, unsigned char rtype, 674 int reqtype) 675 { 676 switch (reqtype) { 677 case HID_REQ_GET_REPORT: 678 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype); 679 case HID_REQ_SET_REPORT: 680 if (buf[0] != reportnum) 681 return -EINVAL; 682 return i2c_hid_output_raw_report(hid, buf, len, rtype, true); 683 default: 684 return -EIO; 685 } 686 } 687 688 static int i2c_hid_parse(struct hid_device *hid) 689 { 690 struct i2c_client *client = hid->driver_data; 691 struct i2c_hid *ihid = i2c_get_clientdata(client); 692 struct i2c_hid_desc *hdesc = &ihid->hdesc; 693 unsigned int rsize; 694 char *rdesc; 695 int ret; 696 int tries = 3; 697 char *use_override; 698 699 i2c_hid_dbg(ihid, "entering %s\n", __func__); 700 701 rsize = le16_to_cpu(hdesc->wReportDescLength); 702 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 703 dbg_hid("weird size of report descriptor (%u)\n", rsize); 704 return -EINVAL; 705 } 706 707 do { 708 ret = i2c_hid_hwreset(client); 709 if (ret) 710 msleep(1000); 711 } while (tries-- > 0 && ret); 712 713 if (ret) 714 return ret; 715 716 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 717 &rsize); 718 719 if (use_override) { 720 rdesc = use_override; 721 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 722 } else { 723 rdesc = kzalloc(rsize, GFP_KERNEL); 724 725 if (!rdesc) { 726 dbg_hid("couldn't allocate rdesc memory\n"); 727 return -ENOMEM; 728 } 729 730 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 731 732 ret = i2c_hid_command(client, &hid_report_descr_cmd, 733 rdesc, rsize); 734 if (ret) { 735 hid_err(hid, "reading report descriptor failed\n"); 736 kfree(rdesc); 737 return -EIO; 738 } 739 } 740 741 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 742 743 ret = hid_parse_report(hid, rdesc, rsize); 744 if (!use_override) 745 kfree(rdesc); 746 747 if (ret) { 748 dbg_hid("parsing report descriptor failed\n"); 749 return ret; 750 } 751 752 return 0; 753 } 754 755 static int i2c_hid_start(struct hid_device *hid) 756 { 757 struct i2c_client *client = hid->driver_data; 758 struct i2c_hid *ihid = i2c_get_clientdata(client); 759 int ret; 760 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 761 762 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 763 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 764 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 765 766 if (bufsize > ihid->bufsize) { 767 disable_irq(client->irq); 768 i2c_hid_free_buffers(ihid); 769 770 ret = i2c_hid_alloc_buffers(ihid, bufsize); 771 enable_irq(client->irq); 772 773 if (ret) 774 return ret; 775 } 776 777 return 0; 778 } 779 780 static void i2c_hid_stop(struct hid_device *hid) 781 { 782 hid->claimed = 0; 783 } 784 785 static int i2c_hid_open(struct hid_device *hid) 786 { 787 struct i2c_client *client = hid->driver_data; 788 struct i2c_hid *ihid = i2c_get_clientdata(client); 789 790 set_bit(I2C_HID_STARTED, &ihid->flags); 791 return 0; 792 } 793 794 static void i2c_hid_close(struct hid_device *hid) 795 { 796 struct i2c_client *client = hid->driver_data; 797 struct i2c_hid *ihid = i2c_get_clientdata(client); 798 799 clear_bit(I2C_HID_STARTED, &ihid->flags); 800 } 801 802 struct hid_ll_driver i2c_hid_ll_driver = { 803 .parse = i2c_hid_parse, 804 .start = i2c_hid_start, 805 .stop = i2c_hid_stop, 806 .open = i2c_hid_open, 807 .close = i2c_hid_close, 808 .output_report = i2c_hid_output_report, 809 .raw_request = i2c_hid_raw_request, 810 }; 811 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); 812 813 static int i2c_hid_init_irq(struct i2c_client *client) 814 { 815 struct i2c_hid *ihid = i2c_get_clientdata(client); 816 unsigned long irqflags = 0; 817 int ret; 818 819 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); 820 821 if (!irq_get_trigger_type(client->irq)) 822 irqflags = IRQF_TRIGGER_LOW; 823 824 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 825 irqflags | IRQF_ONESHOT, client->name, ihid); 826 if (ret < 0) { 827 dev_warn(&client->dev, 828 "Could not register for %s interrupt, irq = %d," 829 " ret = %d\n", 830 client->name, client->irq, ret); 831 832 return ret; 833 } 834 835 return 0; 836 } 837 838 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 839 { 840 struct i2c_client *client = ihid->client; 841 struct i2c_hid_desc *hdesc = &ihid->hdesc; 842 unsigned int dsize; 843 int ret; 844 845 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 846 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 847 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 848 ihid->hdesc = 849 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 850 } else { 851 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 852 ret = i2c_hid_command(client, &hid_descr_cmd, 853 ihid->hdesc_buffer, 854 sizeof(struct i2c_hid_desc)); 855 if (ret) { 856 dev_err(&client->dev, "hid_descr_cmd failed\n"); 857 return -ENODEV; 858 } 859 } 860 861 /* Validate the length of HID descriptor, the 4 first bytes: 862 * bytes 0-1 -> length 863 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 864 /* check bcdVersion == 1.0 */ 865 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 866 dev_err(&client->dev, 867 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 868 le16_to_cpu(hdesc->bcdVersion)); 869 return -ENODEV; 870 } 871 872 /* Descriptor length should be 30 bytes as per the specification */ 873 dsize = le16_to_cpu(hdesc->wHIDDescLength); 874 if (dsize != sizeof(struct i2c_hid_desc)) { 875 dev_err(&client->dev, "weird size of HID descriptor (%u)\n", 876 dsize); 877 return -ENODEV; 878 } 879 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); 880 return 0; 881 } 882 883 #ifdef CONFIG_ACPI 884 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { 885 /* 886 * The CHPN0001 ACPI device, which is used to describe the Chipone 887 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. 888 */ 889 {"CHPN0001", 0 }, 890 { }, 891 }; 892 893 static int i2c_hid_acpi_pdata(struct i2c_client *client, 894 struct i2c_hid_platform_data *pdata) 895 { 896 static guid_t i2c_hid_guid = 897 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 898 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); 899 union acpi_object *obj; 900 struct acpi_device *adev; 901 acpi_handle handle; 902 903 handle = ACPI_HANDLE(&client->dev); 904 if (!handle || acpi_bus_get_device(handle, &adev)) { 905 dev_err(&client->dev, "Error could not get ACPI device\n"); 906 return -ENODEV; 907 } 908 909 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) 910 return -ENODEV; 911 912 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, 913 ACPI_TYPE_INTEGER); 914 if (!obj) { 915 dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n"); 916 return -ENODEV; 917 } 918 919 pdata->hid_descriptor_address = obj->integer.value; 920 ACPI_FREE(obj); 921 922 return 0; 923 } 924 925 static void i2c_hid_acpi_fix_up_power(struct device *dev) 926 { 927 struct acpi_device *adev; 928 929 adev = ACPI_COMPANION(dev); 930 if (adev) 931 acpi_device_fix_up_power(adev); 932 } 933 934 static const struct acpi_device_id i2c_hid_acpi_match[] = { 935 {"ACPI0C50", 0 }, 936 {"PNP0C50", 0 }, 937 { }, 938 }; 939 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); 940 #else 941 static inline int i2c_hid_acpi_pdata(struct i2c_client *client, 942 struct i2c_hid_platform_data *pdata) 943 { 944 return -ENODEV; 945 } 946 947 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} 948 #endif 949 950 #ifdef CONFIG_OF 951 static int i2c_hid_of_probe(struct i2c_client *client, 952 struct i2c_hid_platform_data *pdata) 953 { 954 struct device *dev = &client->dev; 955 u32 val; 956 int ret; 957 958 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); 959 if (ret) { 960 dev_err(&client->dev, "HID register address not provided\n"); 961 return -ENODEV; 962 } 963 if (val >> 16) { 964 dev_err(&client->dev, "Bad HID register address: 0x%08x\n", 965 val); 966 return -EINVAL; 967 } 968 pdata->hid_descriptor_address = val; 969 970 return 0; 971 } 972 973 static const struct of_device_id i2c_hid_of_match[] = { 974 { .compatible = "hid-over-i2c" }, 975 {}, 976 }; 977 MODULE_DEVICE_TABLE(of, i2c_hid_of_match); 978 #else 979 static inline int i2c_hid_of_probe(struct i2c_client *client, 980 struct i2c_hid_platform_data *pdata) 981 { 982 return -ENODEV; 983 } 984 #endif 985 986 static void i2c_hid_fwnode_probe(struct i2c_client *client, 987 struct i2c_hid_platform_data *pdata) 988 { 989 u32 val; 990 991 if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms", 992 &val)) 993 pdata->post_power_delay_ms = val; 994 } 995 996 static int i2c_hid_probe(struct i2c_client *client, 997 const struct i2c_device_id *dev_id) 998 { 999 int ret; 1000 struct i2c_hid *ihid; 1001 struct hid_device *hid; 1002 __u16 hidRegister; 1003 struct i2c_hid_platform_data *platform_data = client->dev.platform_data; 1004 1005 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 1006 1007 if (!client->irq) { 1008 dev_err(&client->dev, 1009 "HID over i2c has not been provided an Int IRQ\n"); 1010 return -EINVAL; 1011 } 1012 1013 if (client->irq < 0) { 1014 if (client->irq != -EPROBE_DEFER) 1015 dev_err(&client->dev, 1016 "HID over i2c doesn't have a valid IRQ\n"); 1017 return client->irq; 1018 } 1019 1020 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1021 if (!ihid) 1022 return -ENOMEM; 1023 1024 if (client->dev.of_node) { 1025 ret = i2c_hid_of_probe(client, &ihid->pdata); 1026 if (ret) 1027 return ret; 1028 } else if (!platform_data) { 1029 ret = i2c_hid_acpi_pdata(client, &ihid->pdata); 1030 if (ret) 1031 return ret; 1032 } else { 1033 ihid->pdata = *platform_data; 1034 } 1035 1036 /* Parse platform agnostic common properties from ACPI / device tree */ 1037 i2c_hid_fwnode_probe(client, &ihid->pdata); 1038 1039 ihid->pdata.supplies[0].supply = "vdd"; 1040 ihid->pdata.supplies[1].supply = "vddl"; 1041 1042 ret = devm_regulator_bulk_get(&client->dev, 1043 ARRAY_SIZE(ihid->pdata.supplies), 1044 ihid->pdata.supplies); 1045 if (ret) 1046 return ret; 1047 1048 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1049 ihid->pdata.supplies); 1050 if (ret < 0) 1051 return ret; 1052 1053 if (ihid->pdata.post_power_delay_ms) 1054 msleep(ihid->pdata.post_power_delay_ms); 1055 1056 i2c_set_clientdata(client, ihid); 1057 1058 ihid->client = client; 1059 1060 hidRegister = ihid->pdata.hid_descriptor_address; 1061 ihid->wHIDDescRegister = cpu_to_le16(hidRegister); 1062 1063 init_waitqueue_head(&ihid->wait); 1064 mutex_init(&ihid->reset_lock); 1065 1066 /* we need to allocate the command buffer without knowing the maximum 1067 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1068 * real computation later. */ 1069 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1070 if (ret < 0) 1071 goto err_regulator; 1072 1073 i2c_hid_acpi_fix_up_power(&client->dev); 1074 1075 device_enable_async_suspend(&client->dev); 1076 1077 /* Make sure there is something at this address */ 1078 ret = i2c_smbus_read_byte(client); 1079 if (ret < 0) { 1080 dev_dbg(&client->dev, "nothing at this address: %d\n", ret); 1081 ret = -ENXIO; 1082 goto err_regulator; 1083 } 1084 1085 ret = i2c_hid_fetch_hid_descriptor(ihid); 1086 if (ret < 0) 1087 goto err_regulator; 1088 1089 ret = i2c_hid_init_irq(client); 1090 if (ret < 0) 1091 goto err_regulator; 1092 1093 hid = hid_allocate_device(); 1094 if (IS_ERR(hid)) { 1095 ret = PTR_ERR(hid); 1096 goto err_irq; 1097 } 1098 1099 ihid->hid = hid; 1100 1101 hid->driver_data = client; 1102 hid->ll_driver = &i2c_hid_ll_driver; 1103 hid->dev.parent = &client->dev; 1104 hid->bus = BUS_I2C; 1105 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1106 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1107 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1108 1109 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX", 1110 client->name, hid->vendor, hid->product); 1111 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1112 1113 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1114 1115 ret = hid_add_device(hid); 1116 if (ret) { 1117 if (ret != -ENODEV) 1118 hid_err(client, "can't add hid device: %d\n", ret); 1119 goto err_mem_free; 1120 } 1121 1122 return 0; 1123 1124 err_mem_free: 1125 hid_destroy_device(hid); 1126 1127 err_irq: 1128 free_irq(client->irq, ihid); 1129 1130 err_regulator: 1131 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1132 ihid->pdata.supplies); 1133 i2c_hid_free_buffers(ihid); 1134 return ret; 1135 } 1136 1137 static int i2c_hid_remove(struct i2c_client *client) 1138 { 1139 struct i2c_hid *ihid = i2c_get_clientdata(client); 1140 struct hid_device *hid; 1141 1142 hid = ihid->hid; 1143 hid_destroy_device(hid); 1144 1145 free_irq(client->irq, ihid); 1146 1147 if (ihid->bufsize) 1148 i2c_hid_free_buffers(ihid); 1149 1150 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1151 ihid->pdata.supplies); 1152 1153 return 0; 1154 } 1155 1156 static void i2c_hid_shutdown(struct i2c_client *client) 1157 { 1158 struct i2c_hid *ihid = i2c_get_clientdata(client); 1159 1160 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1161 free_irq(client->irq, ihid); 1162 } 1163 1164 #ifdef CONFIG_PM_SLEEP 1165 static int i2c_hid_suspend(struct device *dev) 1166 { 1167 struct i2c_client *client = to_i2c_client(dev); 1168 struct i2c_hid *ihid = i2c_get_clientdata(client); 1169 struct hid_device *hid = ihid->hid; 1170 int ret; 1171 int wake_status; 1172 1173 if (hid->driver && hid->driver->suspend) { 1174 ret = hid->driver->suspend(hid, PMSG_SUSPEND); 1175 if (ret < 0) 1176 return ret; 1177 } 1178 1179 /* Save some power */ 1180 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); 1181 1182 disable_irq(client->irq); 1183 1184 if (device_may_wakeup(&client->dev)) { 1185 wake_status = enable_irq_wake(client->irq); 1186 if (!wake_status) 1187 ihid->irq_wake_enabled = true; 1188 else 1189 hid_warn(hid, "Failed to enable irq wake: %d\n", 1190 wake_status); 1191 } else { 1192 regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), 1193 ihid->pdata.supplies); 1194 } 1195 1196 return 0; 1197 } 1198 1199 static int i2c_hid_resume(struct device *dev) 1200 { 1201 int ret; 1202 struct i2c_client *client = to_i2c_client(dev); 1203 struct i2c_hid *ihid = i2c_get_clientdata(client); 1204 struct hid_device *hid = ihid->hid; 1205 int wake_status; 1206 1207 if (!device_may_wakeup(&client->dev)) { 1208 ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), 1209 ihid->pdata.supplies); 1210 if (ret) 1211 hid_warn(hid, "Failed to enable supplies: %d\n", ret); 1212 1213 if (ihid->pdata.post_power_delay_ms) 1214 msleep(ihid->pdata.post_power_delay_ms); 1215 } else if (ihid->irq_wake_enabled) { 1216 wake_status = disable_irq_wake(client->irq); 1217 if (!wake_status) 1218 ihid->irq_wake_enabled = false; 1219 else 1220 hid_warn(hid, "Failed to disable irq wake: %d\n", 1221 wake_status); 1222 } 1223 1224 enable_irq(client->irq); 1225 1226 /* Instead of resetting device, simply powers the device on. This 1227 * solves "incomplete reports" on Raydium devices 2386:3118 and 1228 * 2386:4B33 and fixes various SIS touchscreens no longer sending 1229 * data after a suspend/resume. 1230 * 1231 * However some ALPS touchpads generate IRQ storm without reset, so 1232 * let's still reset them here. 1233 */ 1234 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) 1235 ret = i2c_hid_hwreset(client); 1236 else 1237 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); 1238 1239 if (ret) 1240 return ret; 1241 1242 if (hid->driver && hid->driver->reset_resume) { 1243 ret = hid->driver->reset_resume(hid); 1244 return ret; 1245 } 1246 1247 return 0; 1248 } 1249 #endif 1250 1251 static const struct dev_pm_ops i2c_hid_pm = { 1252 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume) 1253 }; 1254 1255 static const struct i2c_device_id i2c_hid_id_table[] = { 1256 { "hid", 0 }, 1257 { "hid-over-i2c", 0 }, 1258 { }, 1259 }; 1260 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); 1261 1262 1263 static struct i2c_driver i2c_hid_driver = { 1264 .driver = { 1265 .name = "i2c_hid", 1266 .pm = &i2c_hid_pm, 1267 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), 1268 .of_match_table = of_match_ptr(i2c_hid_of_match), 1269 }, 1270 1271 .probe = i2c_hid_probe, 1272 .remove = i2c_hid_remove, 1273 .shutdown = i2c_hid_shutdown, 1274 .id_table = i2c_hid_id_table, 1275 }; 1276 1277 module_i2c_driver(i2c_hid_driver); 1278 1279 MODULE_DESCRIPTION("HID over I2C core driver"); 1280 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1281 MODULE_LICENSE("GPL"); 1282