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 <asm/unaligned.h> 39 40 #include "../hid-ids.h" 41 #include "i2c-hid.h" 42 43 /* quirks to control the device */ 44 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0) 45 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1) 46 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(4) 47 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(5) 48 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(6) 49 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(7) 50 51 /* Command opcodes */ 52 #define I2C_HID_OPCODE_RESET 0x01 53 #define I2C_HID_OPCODE_GET_REPORT 0x02 54 #define I2C_HID_OPCODE_SET_REPORT 0x03 55 #define I2C_HID_OPCODE_GET_IDLE 0x04 56 #define I2C_HID_OPCODE_SET_IDLE 0x05 57 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06 58 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07 59 #define I2C_HID_OPCODE_SET_POWER 0x08 60 61 /* flags */ 62 #define I2C_HID_STARTED 0 63 #define I2C_HID_RESET_PENDING 1 64 #define I2C_HID_READ_PENDING 2 65 66 #define I2C_HID_PWR_ON 0x00 67 #define I2C_HID_PWR_SLEEP 0x01 68 69 /* debug option */ 70 static bool debug; 71 module_param(debug, bool, 0444); 72 MODULE_PARM_DESC(debug, "print a lot of debug information"); 73 74 #define i2c_hid_dbg(ihid, fmt, arg...) \ 75 do { \ 76 if (debug) \ 77 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \ 78 } while (0) 79 80 struct i2c_hid_desc { 81 __le16 wHIDDescLength; 82 __le16 bcdVersion; 83 __le16 wReportDescLength; 84 __le16 wReportDescRegister; 85 __le16 wInputRegister; 86 __le16 wMaxInputLength; 87 __le16 wOutputRegister; 88 __le16 wMaxOutputLength; 89 __le16 wCommandRegister; 90 __le16 wDataRegister; 91 __le16 wVendorID; 92 __le16 wProductID; 93 __le16 wVersionID; 94 __le32 reserved; 95 } __packed; 96 97 /* The main device structure */ 98 struct i2c_hid { 99 struct i2c_client *client; /* i2c client */ 100 struct hid_device *hid; /* pointer to corresponding HID dev */ 101 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 102 __le16 wHIDDescRegister; /* location of the i2c 103 * register of the HID 104 * descriptor. */ 105 unsigned int bufsize; /* i2c buffer size */ 106 u8 *inbuf; /* Input buffer */ 107 u8 *rawbuf; /* Raw Input buffer */ 108 u8 *cmdbuf; /* Command buffer */ 109 110 unsigned long flags; /* device flags */ 111 unsigned long quirks; /* Various quirks */ 112 113 wait_queue_head_t wait; /* For waiting the interrupt */ 114 115 bool irq_wake_enabled; 116 struct mutex reset_lock; 117 118 struct i2chid_ops *ops; 119 }; 120 121 static const struct i2c_hid_quirks { 122 __u16 idVendor; 123 __u16 idProduct; 124 __u32 quirks; 125 } i2c_hid_quirks[] = { 126 { USB_VENDOR_ID_WEIDA, HID_ANY_ID, 127 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, 128 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 129 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 130 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15, 131 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 132 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118, 133 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 134 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID, 135 I2C_HID_QUIRK_RESET_ON_RESUME }, 136 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393, 137 I2C_HID_QUIRK_RESET_ON_RESUME }, 138 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720, 139 I2C_HID_QUIRK_BAD_INPUT_SIZE }, 140 /* 141 * Sending the wakeup after reset actually break ELAN touchscreen controller 142 */ 143 { USB_VENDOR_ID_ELAN, HID_ANY_ID, 144 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET | 145 I2C_HID_QUIRK_BOGUS_IRQ }, 146 { 0, 0 } 147 }; 148 149 /* 150 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device 151 * @idVendor: the 16-bit vendor ID 152 * @idProduct: the 16-bit product ID 153 * 154 * Returns: a u32 quirks value. 155 */ 156 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) 157 { 158 u32 quirks = 0; 159 int n; 160 161 for (n = 0; i2c_hid_quirks[n].idVendor; n++) 162 if (i2c_hid_quirks[n].idVendor == idVendor && 163 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || 164 i2c_hid_quirks[n].idProduct == idProduct)) 165 quirks = i2c_hid_quirks[n].quirks; 166 167 return quirks; 168 } 169 170 static int i2c_hid_xfer(struct i2c_hid *ihid, 171 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len) 172 { 173 struct i2c_client *client = ihid->client; 174 struct i2c_msg msgs[2] = { 0 }; 175 int n = 0; 176 int ret; 177 178 if (send_len) { 179 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", 180 __func__, send_len, send_buf); 181 182 msgs[n].addr = client->addr; 183 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE; 184 msgs[n].len = send_len; 185 msgs[n].buf = send_buf; 186 n++; 187 } 188 189 if (recv_len) { 190 msgs[n].addr = client->addr; 191 msgs[n].flags = (client->flags & I2C_M_TEN) | 192 I2C_M_RD | I2C_M_DMA_SAFE; 193 msgs[n].len = recv_len; 194 msgs[n].buf = recv_buf; 195 n++; 196 197 set_bit(I2C_HID_READ_PENDING, &ihid->flags); 198 } 199 200 ret = i2c_transfer(client->adapter, msgs, n); 201 202 if (recv_len) 203 clear_bit(I2C_HID_READ_PENDING, &ihid->flags); 204 205 if (ret != n) 206 return ret < 0 ? ret : -EIO; 207 208 return 0; 209 } 210 211 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg, 212 void *buf, size_t len) 213 { 214 *(__le16 *)ihid->cmdbuf = reg; 215 216 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len); 217 } 218 219 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode, 220 int report_type, int report_id) 221 { 222 size_t length = 0; 223 224 if (report_id < 0x0F) { 225 buf[length++] = report_type << 4 | report_id; 226 buf[length++] = opcode; 227 } else { 228 buf[length++] = report_type << 4 | 0x0F; 229 buf[length++] = opcode; 230 buf[length++] = report_id; 231 } 232 233 return length; 234 } 235 236 static int i2c_hid_get_report(struct i2c_hid *ihid, 237 u8 report_type, u8 report_id, 238 u8 *recv_buf, size_t recv_len) 239 { 240 size_t length = 0; 241 size_t ret_count; 242 int error; 243 244 i2c_hid_dbg(ihid, "%s\n", __func__); 245 246 /* Command register goes first */ 247 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 248 length += sizeof(__le16); 249 /* Next is GET_REPORT command */ 250 length += i2c_hid_encode_command(ihid->cmdbuf + length, 251 I2C_HID_OPCODE_GET_REPORT, 252 report_type, report_id); 253 /* 254 * Device will send report data through data register. Because 255 * command can be either 2 or 3 bytes destination for the data 256 * register may be not aligned. 257 */ 258 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 259 ihid->cmdbuf + length); 260 length += sizeof(__le16); 261 262 /* 263 * In addition to report data device will supply data length 264 * in the first 2 bytes of the response, so adjust . 265 */ 266 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, 267 ihid->rawbuf, recv_len + sizeof(__le16)); 268 if (error) { 269 dev_err(&ihid->client->dev, 270 "failed to set a report to device: %d\n", error); 271 return error; 272 } 273 274 /* The buffer is sufficiently aligned */ 275 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf); 276 277 /* Check for empty report response */ 278 if (ret_count <= sizeof(__le16)) 279 return 0; 280 281 recv_len = min(recv_len, ret_count - sizeof(__le16)); 282 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len); 283 284 if (report_id && recv_len != 0 && recv_buf[0] != report_id) { 285 dev_err(&ihid->client->dev, 286 "device returned incorrect report (%d vs %d expected)\n", 287 recv_buf[0], report_id); 288 return -EINVAL; 289 } 290 291 return recv_len; 292 } 293 294 static size_t i2c_hid_format_report(u8 *buf, int report_id, 295 const u8 *data, size_t size) 296 { 297 size_t length = sizeof(__le16); /* reserve space to store size */ 298 299 if (report_id) 300 buf[length++] = report_id; 301 302 memcpy(buf + length, data, size); 303 length += size; 304 305 /* Store overall size in the beginning of the buffer */ 306 put_unaligned_le16(length, buf); 307 308 return length; 309 } 310 311 /** 312 * i2c_hid_set_or_send_report: forward an incoming report to the device 313 * @ihid: the i2c hid device 314 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 315 * @report_id: the report ID 316 * @buf: the actual data to transfer, without the report ID 317 * @data_len: size of buf 318 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report 319 */ 320 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid, 321 u8 report_type, u8 report_id, 322 const u8 *buf, size_t data_len, 323 bool do_set) 324 { 325 size_t length = 0; 326 int error; 327 328 i2c_hid_dbg(ihid, "%s\n", __func__); 329 330 if (data_len > ihid->bufsize) 331 return -EINVAL; 332 333 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0) 334 return -ENOSYS; 335 336 if (do_set) { 337 /* Command register goes first */ 338 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 339 length += sizeof(__le16); 340 /* Next is SET_REPORT command */ 341 length += i2c_hid_encode_command(ihid->cmdbuf + length, 342 I2C_HID_OPCODE_SET_REPORT, 343 report_type, report_id); 344 /* 345 * Report data will go into the data register. Because 346 * command can be either 2 or 3 bytes destination for 347 * the data register may be not aligned. 348 */ 349 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 350 ihid->cmdbuf + length); 351 length += sizeof(__le16); 352 } else { 353 /* 354 * With simple "send report" all data goes into the output 355 * register. 356 */ 357 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister; 358 length += sizeof(__le16); 359 } 360 361 length += i2c_hid_format_report(ihid->cmdbuf + length, 362 report_id, buf, data_len); 363 364 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 365 if (error) { 366 dev_err(&ihid->client->dev, 367 "failed to set a report to device: %d\n", error); 368 return error; 369 } 370 371 return data_len; 372 } 373 374 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state) 375 { 376 size_t length; 377 378 /* SET_POWER uses command register */ 379 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 380 length = sizeof(__le16); 381 382 /* Now the command itself */ 383 length += i2c_hid_encode_command(ihid->cmdbuf + length, 384 I2C_HID_OPCODE_SET_POWER, 385 0, power_state); 386 387 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 388 } 389 390 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state) 391 { 392 int ret; 393 394 i2c_hid_dbg(ihid, "%s\n", __func__); 395 396 /* 397 * Some devices require to send a command to wakeup before power on. 398 * The call will get a return value (EREMOTEIO) but device will be 399 * triggered and activated. After that, it goes like a normal device. 400 */ 401 if (power_state == I2C_HID_PWR_ON && 402 ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) { 403 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON); 404 405 /* Device was already activated */ 406 if (!ret) 407 goto set_pwr_exit; 408 } 409 410 ret = i2c_hid_set_power_command(ihid, power_state); 411 if (ret) 412 dev_err(&ihid->client->dev, 413 "failed to change power setting.\n"); 414 415 set_pwr_exit: 416 417 /* 418 * The HID over I2C specification states that if a DEVICE needs time 419 * after the PWR_ON request, it should utilise CLOCK stretching. 420 * However, it has been observered that the Windows driver provides a 421 * 1ms sleep between the PWR_ON and RESET requests. 422 * According to Goodix Windows even waits 60 ms after (other?) 423 * PWR_ON requests. Testing has confirmed that several devices 424 * will not work properly without a delay after a PWR_ON request. 425 */ 426 if (!ret && power_state == I2C_HID_PWR_ON) 427 msleep(60); 428 429 return ret; 430 } 431 432 static int i2c_hid_execute_reset(struct i2c_hid *ihid) 433 { 434 size_t length = 0; 435 int ret; 436 437 i2c_hid_dbg(ihid, "resetting...\n"); 438 439 /* Prepare reset command. Command register goes first. */ 440 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 441 length += sizeof(__le16); 442 /* Next is RESET command itself */ 443 length += i2c_hid_encode_command(ihid->cmdbuf + length, 444 I2C_HID_OPCODE_RESET, 0, 0); 445 446 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 447 448 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 449 if (ret) { 450 dev_err(&ihid->client->dev, "failed to reset device.\n"); 451 goto out; 452 } 453 454 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) { 455 msleep(100); 456 goto out; 457 } 458 459 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 460 if (!wait_event_timeout(ihid->wait, 461 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 462 msecs_to_jiffies(5000))) { 463 ret = -ENODATA; 464 goto out; 465 } 466 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 467 468 out: 469 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 470 return ret; 471 } 472 473 static int i2c_hid_hwreset(struct i2c_hid *ihid) 474 { 475 int ret; 476 477 i2c_hid_dbg(ihid, "%s\n", __func__); 478 479 /* 480 * This prevents sending feature reports while the device is 481 * being reset. Otherwise we may lose the reset complete 482 * interrupt. 483 */ 484 mutex_lock(&ihid->reset_lock); 485 486 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 487 if (ret) 488 goto out_unlock; 489 490 ret = i2c_hid_execute_reset(ihid); 491 if (ret) { 492 dev_err(&ihid->client->dev, 493 "failed to reset device: %d\n", ret); 494 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 495 goto out_unlock; 496 } 497 498 /* At least some SIS devices need this after reset */ 499 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET)) 500 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 501 502 out_unlock: 503 mutex_unlock(&ihid->reset_lock); 504 return ret; 505 } 506 507 static void i2c_hid_get_input(struct i2c_hid *ihid) 508 { 509 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 510 u16 ret_size; 511 int ret; 512 513 if (size > ihid->bufsize) 514 size = ihid->bufsize; 515 516 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 517 if (ret != size) { 518 if (ret < 0) 519 return; 520 521 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 522 __func__, ret, size); 523 return; 524 } 525 526 /* Receiving buffer is properly aligned */ 527 ret_size = le16_to_cpup((__le16 *)ihid->inbuf); 528 if (!ret_size) { 529 /* host or device initiated RESET completed */ 530 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 531 wake_up(&ihid->wait); 532 return; 533 } 534 535 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) { 536 dev_warn_once(&ihid->client->dev, 537 "%s: IRQ triggered but there's no data\n", 538 __func__); 539 return; 540 } 541 542 if (ret_size > size || ret_size < sizeof(__le16)) { 543 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) { 544 *(__le16 *)ihid->inbuf = cpu_to_le16(size); 545 ret_size = size; 546 } else { 547 dev_err(&ihid->client->dev, 548 "%s: incomplete report (%d/%d)\n", 549 __func__, size, ret_size); 550 return; 551 } 552 } 553 554 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 555 556 if (test_bit(I2C_HID_STARTED, &ihid->flags)) { 557 pm_wakeup_event(&ihid->client->dev, 0); 558 559 hid_input_report(ihid->hid, HID_INPUT_REPORT, 560 ihid->inbuf + sizeof(__le16), 561 ret_size - sizeof(__le16), 1); 562 } 563 564 return; 565 } 566 567 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 568 { 569 struct i2c_hid *ihid = dev_id; 570 571 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) 572 return IRQ_HANDLED; 573 574 i2c_hid_get_input(ihid); 575 576 return IRQ_HANDLED; 577 } 578 579 static int i2c_hid_get_report_length(struct hid_report *report) 580 { 581 return ((report->size - 1) >> 3) + 1 + 582 report->device->report_enum[report->type].numbered + 2; 583 } 584 585 /* 586 * Traverse the supplied list of reports and find the longest 587 */ 588 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 589 unsigned int *max) 590 { 591 struct hid_report *report; 592 unsigned int size; 593 594 /* We should not rely on wMaxInputLength, as some devices may set it to 595 * a wrong length. */ 596 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 597 size = i2c_hid_get_report_length(report); 598 if (*max < size) 599 *max = size; 600 } 601 } 602 603 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 604 { 605 kfree(ihid->inbuf); 606 kfree(ihid->rawbuf); 607 kfree(ihid->cmdbuf); 608 ihid->inbuf = NULL; 609 ihid->rawbuf = NULL; 610 ihid->cmdbuf = NULL; 611 ihid->bufsize = 0; 612 } 613 614 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 615 { 616 /* 617 * The worst case is computed from the set_report command with a 618 * reportID > 15 and the maximum report length. 619 */ 620 int cmd_len = sizeof(__le16) + /* command register */ 621 sizeof(u8) + /* encoded report type/ID */ 622 sizeof(u8) + /* opcode */ 623 sizeof(u8) + /* optional 3rd byte report ID */ 624 sizeof(__le16) + /* data register */ 625 sizeof(__le16) + /* report data size */ 626 sizeof(u8) + /* report ID if numbered report */ 627 report_size; 628 629 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 630 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 631 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL); 632 633 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) { 634 i2c_hid_free_buffers(ihid); 635 return -ENOMEM; 636 } 637 638 ihid->bufsize = report_size; 639 640 return 0; 641 } 642 643 static int i2c_hid_get_raw_report(struct hid_device *hid, 644 u8 report_type, u8 report_id, 645 u8 *buf, size_t count) 646 { 647 struct i2c_client *client = hid->driver_data; 648 struct i2c_hid *ihid = i2c_get_clientdata(client); 649 int ret_count; 650 651 if (report_type == HID_OUTPUT_REPORT) 652 return -EINVAL; 653 654 /* 655 * In case of unnumbered reports the response from the device will 656 * not have the report ID that the upper layers expect, so we need 657 * to stash it the buffer ourselves and adjust the data size. 658 */ 659 if (!report_id) { 660 buf[0] = 0; 661 buf++; 662 count--; 663 } 664 665 ret_count = i2c_hid_get_report(ihid, 666 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 667 report_id, buf, count); 668 669 if (ret_count > 0 && !report_id) 670 ret_count++; 671 672 return ret_count; 673 } 674 675 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type, 676 const u8 *buf, size_t count, bool do_set) 677 { 678 struct i2c_client *client = hid->driver_data; 679 struct i2c_hid *ihid = i2c_get_clientdata(client); 680 int report_id = buf[0]; 681 int ret; 682 683 if (report_type == HID_INPUT_REPORT) 684 return -EINVAL; 685 686 mutex_lock(&ihid->reset_lock); 687 688 /* 689 * Note that both numbered and unnumbered reports passed here 690 * are supposed to have report ID stored in the 1st byte of the 691 * buffer, so we strip it off unconditionally before passing payload 692 * to i2c_hid_set_or_send_report which takes care of encoding 693 * everything properly. 694 */ 695 ret = i2c_hid_set_or_send_report(ihid, 696 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 697 report_id, buf + 1, count - 1, do_set); 698 699 if (ret >= 0) 700 ret++; /* add report_id to the number of transferred bytes */ 701 702 mutex_unlock(&ihid->reset_lock); 703 704 return ret; 705 } 706 707 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count) 708 { 709 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count, 710 false); 711 } 712 713 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 714 __u8 *buf, size_t len, unsigned char rtype, 715 int reqtype) 716 { 717 switch (reqtype) { 718 case HID_REQ_GET_REPORT: 719 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len); 720 case HID_REQ_SET_REPORT: 721 if (buf[0] != reportnum) 722 return -EINVAL; 723 return i2c_hid_output_raw_report(hid, rtype, buf, len, true); 724 default: 725 return -EIO; 726 } 727 } 728 729 static int i2c_hid_parse(struct hid_device *hid) 730 { 731 struct i2c_client *client = hid->driver_data; 732 struct i2c_hid *ihid = i2c_get_clientdata(client); 733 struct i2c_hid_desc *hdesc = &ihid->hdesc; 734 unsigned int rsize; 735 char *rdesc; 736 int ret; 737 int tries = 3; 738 char *use_override; 739 740 i2c_hid_dbg(ihid, "entering %s\n", __func__); 741 742 rsize = le16_to_cpu(hdesc->wReportDescLength); 743 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 744 dbg_hid("weird size of report descriptor (%u)\n", rsize); 745 return -EINVAL; 746 } 747 748 do { 749 ret = i2c_hid_hwreset(ihid); 750 if (ret) 751 msleep(1000); 752 } while (tries-- > 0 && ret); 753 754 if (ret) 755 return ret; 756 757 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 758 &rsize); 759 760 if (use_override) { 761 rdesc = use_override; 762 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 763 } else { 764 rdesc = kzalloc(rsize, GFP_KERNEL); 765 766 if (!rdesc) { 767 dbg_hid("couldn't allocate rdesc memory\n"); 768 return -ENOMEM; 769 } 770 771 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 772 773 ret = i2c_hid_read_register(ihid, 774 ihid->hdesc.wReportDescRegister, 775 rdesc, rsize); 776 if (ret) { 777 hid_err(hid, "reading report descriptor failed\n"); 778 kfree(rdesc); 779 return -EIO; 780 } 781 } 782 783 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 784 785 ret = hid_parse_report(hid, rdesc, rsize); 786 if (!use_override) 787 kfree(rdesc); 788 789 if (ret) { 790 dbg_hid("parsing report descriptor failed\n"); 791 return ret; 792 } 793 794 return 0; 795 } 796 797 static int i2c_hid_start(struct hid_device *hid) 798 { 799 struct i2c_client *client = hid->driver_data; 800 struct i2c_hid *ihid = i2c_get_clientdata(client); 801 int ret; 802 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 803 804 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 805 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 806 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 807 808 if (bufsize > ihid->bufsize) { 809 disable_irq(client->irq); 810 i2c_hid_free_buffers(ihid); 811 812 ret = i2c_hid_alloc_buffers(ihid, bufsize); 813 enable_irq(client->irq); 814 815 if (ret) 816 return ret; 817 } 818 819 return 0; 820 } 821 822 static void i2c_hid_stop(struct hid_device *hid) 823 { 824 hid->claimed = 0; 825 } 826 827 static int i2c_hid_open(struct hid_device *hid) 828 { 829 struct i2c_client *client = hid->driver_data; 830 struct i2c_hid *ihid = i2c_get_clientdata(client); 831 832 set_bit(I2C_HID_STARTED, &ihid->flags); 833 return 0; 834 } 835 836 static void i2c_hid_close(struct hid_device *hid) 837 { 838 struct i2c_client *client = hid->driver_data; 839 struct i2c_hid *ihid = i2c_get_clientdata(client); 840 841 clear_bit(I2C_HID_STARTED, &ihid->flags); 842 } 843 844 struct hid_ll_driver i2c_hid_ll_driver = { 845 .parse = i2c_hid_parse, 846 .start = i2c_hid_start, 847 .stop = i2c_hid_stop, 848 .open = i2c_hid_open, 849 .close = i2c_hid_close, 850 .output_report = i2c_hid_output_report, 851 .raw_request = i2c_hid_raw_request, 852 }; 853 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); 854 855 static int i2c_hid_init_irq(struct i2c_client *client) 856 { 857 struct i2c_hid *ihid = i2c_get_clientdata(client); 858 unsigned long irqflags = 0; 859 int ret; 860 861 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); 862 863 if (!irq_get_trigger_type(client->irq)) 864 irqflags = IRQF_TRIGGER_LOW; 865 866 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 867 irqflags | IRQF_ONESHOT, client->name, ihid); 868 if (ret < 0) { 869 dev_warn(&client->dev, 870 "Could not register for %s interrupt, irq = %d," 871 " ret = %d\n", 872 client->name, client->irq, ret); 873 874 return ret; 875 } 876 877 return 0; 878 } 879 880 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 881 { 882 struct i2c_client *client = ihid->client; 883 struct i2c_hid_desc *hdesc = &ihid->hdesc; 884 unsigned int dsize; 885 int error; 886 887 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 888 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 889 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 890 ihid->hdesc = 891 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 892 } else { 893 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 894 error = i2c_hid_read_register(ihid, 895 ihid->wHIDDescRegister, 896 &ihid->hdesc, 897 sizeof(ihid->hdesc)); 898 if (error) { 899 dev_err(&ihid->client->dev, 900 "failed to fetch HID descriptor: %d\n", 901 error); 902 return -ENODEV; 903 } 904 } 905 906 /* Validate the length of HID descriptor, the 4 first bytes: 907 * bytes 0-1 -> length 908 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 909 /* check bcdVersion == 1.0 */ 910 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 911 dev_err(&ihid->client->dev, 912 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 913 le16_to_cpu(hdesc->bcdVersion)); 914 return -ENODEV; 915 } 916 917 /* Descriptor length should be 30 bytes as per the specification */ 918 dsize = le16_to_cpu(hdesc->wHIDDescLength); 919 if (dsize != sizeof(struct i2c_hid_desc)) { 920 dev_err(&ihid->client->dev, 921 "weird size of HID descriptor (%u)\n", dsize); 922 return -ENODEV; 923 } 924 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc); 925 return 0; 926 } 927 928 static int i2c_hid_core_power_up(struct i2c_hid *ihid) 929 { 930 if (!ihid->ops->power_up) 931 return 0; 932 933 return ihid->ops->power_up(ihid->ops); 934 } 935 936 static void i2c_hid_core_power_down(struct i2c_hid *ihid) 937 { 938 if (!ihid->ops->power_down) 939 return; 940 941 ihid->ops->power_down(ihid->ops); 942 } 943 944 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid) 945 { 946 if (!ihid->ops->shutdown_tail) 947 return; 948 949 ihid->ops->shutdown_tail(ihid->ops); 950 } 951 952 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, 953 u16 hid_descriptor_address, u32 quirks) 954 { 955 int ret; 956 struct i2c_hid *ihid; 957 struct hid_device *hid; 958 959 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 960 961 if (!client->irq) { 962 dev_err(&client->dev, 963 "HID over i2c has not been provided an Int IRQ\n"); 964 return -EINVAL; 965 } 966 967 if (client->irq < 0) { 968 if (client->irq != -EPROBE_DEFER) 969 dev_err(&client->dev, 970 "HID over i2c doesn't have a valid IRQ\n"); 971 return client->irq; 972 } 973 974 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 975 if (!ihid) 976 return -ENOMEM; 977 978 ihid->ops = ops; 979 980 ret = i2c_hid_core_power_up(ihid); 981 if (ret) 982 return ret; 983 984 i2c_set_clientdata(client, ihid); 985 986 ihid->client = client; 987 988 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address); 989 990 init_waitqueue_head(&ihid->wait); 991 mutex_init(&ihid->reset_lock); 992 993 /* we need to allocate the command buffer without knowing the maximum 994 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 995 * real computation later. */ 996 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 997 if (ret < 0) 998 goto err_powered; 999 1000 device_enable_async_suspend(&client->dev); 1001 1002 /* Make sure there is something at this address */ 1003 ret = i2c_smbus_read_byte(client); 1004 if (ret < 0) { 1005 dev_dbg(&client->dev, "nothing at this address: %d\n", ret); 1006 ret = -ENXIO; 1007 goto err_powered; 1008 } 1009 1010 ret = i2c_hid_fetch_hid_descriptor(ihid); 1011 if (ret < 0) { 1012 dev_err(&client->dev, 1013 "Failed to fetch the HID Descriptor\n"); 1014 goto err_powered; 1015 } 1016 1017 ret = i2c_hid_init_irq(client); 1018 if (ret < 0) 1019 goto err_powered; 1020 1021 hid = hid_allocate_device(); 1022 if (IS_ERR(hid)) { 1023 ret = PTR_ERR(hid); 1024 goto err_irq; 1025 } 1026 1027 ihid->hid = hid; 1028 1029 hid->driver_data = client; 1030 hid->ll_driver = &i2c_hid_ll_driver; 1031 hid->dev.parent = &client->dev; 1032 hid->bus = BUS_I2C; 1033 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1034 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1035 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1036 1037 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", 1038 client->name, (u16)hid->vendor, (u16)hid->product); 1039 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1040 1041 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1042 1043 ret = hid_add_device(hid); 1044 if (ret) { 1045 if (ret != -ENODEV) 1046 hid_err(client, "can't add hid device: %d\n", ret); 1047 goto err_mem_free; 1048 } 1049 1050 hid->quirks |= quirks; 1051 1052 return 0; 1053 1054 err_mem_free: 1055 hid_destroy_device(hid); 1056 1057 err_irq: 1058 free_irq(client->irq, ihid); 1059 1060 err_powered: 1061 i2c_hid_core_power_down(ihid); 1062 i2c_hid_free_buffers(ihid); 1063 return ret; 1064 } 1065 EXPORT_SYMBOL_GPL(i2c_hid_core_probe); 1066 1067 void i2c_hid_core_remove(struct i2c_client *client) 1068 { 1069 struct i2c_hid *ihid = i2c_get_clientdata(client); 1070 struct hid_device *hid; 1071 1072 hid = ihid->hid; 1073 hid_destroy_device(hid); 1074 1075 free_irq(client->irq, ihid); 1076 1077 if (ihid->bufsize) 1078 i2c_hid_free_buffers(ihid); 1079 1080 i2c_hid_core_power_down(ihid); 1081 } 1082 EXPORT_SYMBOL_GPL(i2c_hid_core_remove); 1083 1084 void i2c_hid_core_shutdown(struct i2c_client *client) 1085 { 1086 struct i2c_hid *ihid = i2c_get_clientdata(client); 1087 1088 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 1089 free_irq(client->irq, ihid); 1090 1091 i2c_hid_core_shutdown_tail(ihid); 1092 } 1093 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown); 1094 1095 #ifdef CONFIG_PM_SLEEP 1096 static int i2c_hid_core_suspend(struct device *dev) 1097 { 1098 struct i2c_client *client = to_i2c_client(dev); 1099 struct i2c_hid *ihid = i2c_get_clientdata(client); 1100 struct hid_device *hid = ihid->hid; 1101 int ret; 1102 int wake_status; 1103 1104 ret = hid_driver_suspend(hid, PMSG_SUSPEND); 1105 if (ret < 0) 1106 return ret; 1107 1108 /* Save some power */ 1109 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 1110 1111 disable_irq(client->irq); 1112 1113 if (device_may_wakeup(&client->dev)) { 1114 wake_status = enable_irq_wake(client->irq); 1115 if (!wake_status) 1116 ihid->irq_wake_enabled = true; 1117 else 1118 hid_warn(hid, "Failed to enable irq wake: %d\n", 1119 wake_status); 1120 } else { 1121 i2c_hid_core_power_down(ihid); 1122 } 1123 1124 return 0; 1125 } 1126 1127 static int i2c_hid_core_resume(struct device *dev) 1128 { 1129 int ret; 1130 struct i2c_client *client = to_i2c_client(dev); 1131 struct i2c_hid *ihid = i2c_get_clientdata(client); 1132 struct hid_device *hid = ihid->hid; 1133 int wake_status; 1134 1135 if (!device_may_wakeup(&client->dev)) { 1136 i2c_hid_core_power_up(ihid); 1137 } else if (ihid->irq_wake_enabled) { 1138 wake_status = disable_irq_wake(client->irq); 1139 if (!wake_status) 1140 ihid->irq_wake_enabled = false; 1141 else 1142 hid_warn(hid, "Failed to disable irq wake: %d\n", 1143 wake_status); 1144 } 1145 1146 enable_irq(client->irq); 1147 1148 /* Instead of resetting device, simply powers the device on. This 1149 * solves "incomplete reports" on Raydium devices 2386:3118 and 1150 * 2386:4B33 and fixes various SIS touchscreens no longer sending 1151 * data after a suspend/resume. 1152 * 1153 * However some ALPS touchpads generate IRQ storm without reset, so 1154 * let's still reset them here. 1155 */ 1156 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) 1157 ret = i2c_hid_hwreset(ihid); 1158 else 1159 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 1160 1161 if (ret) 1162 return ret; 1163 1164 return hid_driver_reset_resume(hid); 1165 } 1166 #endif 1167 1168 const struct dev_pm_ops i2c_hid_core_pm = { 1169 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume) 1170 }; 1171 EXPORT_SYMBOL_GPL(i2c_hid_core_pm); 1172 1173 MODULE_DESCRIPTION("HID over I2C core driver"); 1174 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1175 MODULE_LICENSE("GPL"); 1176