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_wakeirq.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/unaligned.h> 40 41 #include <drm/drm_panel.h> 42 43 #include "../hid-ids.h" 44 #include "i2c-hid.h" 45 46 /* quirks to control the device */ 47 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(0) 48 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(1) 49 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(2) 50 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(3) 51 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(4) 52 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND BIT(5) 53 #define I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME BIT(6) 54 55 /* Command opcodes */ 56 #define I2C_HID_OPCODE_RESET 0x01 57 #define I2C_HID_OPCODE_GET_REPORT 0x02 58 #define I2C_HID_OPCODE_SET_REPORT 0x03 59 #define I2C_HID_OPCODE_GET_IDLE 0x04 60 #define I2C_HID_OPCODE_SET_IDLE 0x05 61 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06 62 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07 63 #define I2C_HID_OPCODE_SET_POWER 0x08 64 65 /* flags */ 66 #define I2C_HID_STARTED 0 67 #define I2C_HID_RESET_PENDING 1 68 69 #define I2C_HID_PWR_ON 0x00 70 #define I2C_HID_PWR_SLEEP 0x01 71 72 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__) 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 /* The main device structure */ 92 struct i2c_hid { 93 struct i2c_client *client; /* i2c client */ 94 struct hid_device *hid; /* pointer to corresponding HID dev */ 95 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 96 __le16 wHIDDescRegister; /* location of the i2c 97 * register of the HID 98 * descriptor. */ 99 unsigned int bufsize; /* i2c buffer size */ 100 u8 *inbuf; /* Input buffer */ 101 u8 *rawbuf; /* Raw Input buffer */ 102 u8 *cmdbuf; /* Command buffer */ 103 104 unsigned long flags; /* device flags */ 105 unsigned long quirks; /* Various quirks */ 106 107 wait_queue_head_t wait; /* For waiting the interrupt */ 108 109 struct mutex cmd_lock; /* protects cmdbuf and rawbuf */ 110 struct mutex reset_lock; 111 112 struct i2chid_ops *ops; 113 struct drm_panel_follower panel_follower; 114 struct work_struct panel_follower_prepare_work; 115 bool is_panel_follower; 116 bool prepare_work_finished; 117 }; 118 119 static const struct i2c_hid_quirks { 120 __u16 idVendor; 121 __u16 idProduct; 122 __u32 quirks; 123 } i2c_hid_quirks[] = { 124 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 125 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 126 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15, 127 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 128 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118, 129 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 130 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID, 131 I2C_HID_QUIRK_RESET_ON_RESUME }, 132 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393, 133 I2C_HID_QUIRK_RESET_ON_RESUME }, 134 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720, 135 I2C_HID_QUIRK_BAD_INPUT_SIZE }, 136 { I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063, 137 I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND }, 138 /* 139 * Sending the wakeup after reset actually break ELAN touchscreen controller 140 */ 141 { USB_VENDOR_ID_ELAN, HID_ANY_ID, 142 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET | 143 I2C_HID_QUIRK_BOGUS_IRQ }, 144 { I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_0D42, 145 I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME }, 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_probe_address(struct i2c_hid *ihid) 171 { 172 int ret; 173 174 /* 175 * Some STM-based devices need 400µs after a rising clock edge to wake 176 * from deep sleep, in which case the first read will fail. Try after a 177 * short sleep to see if the device came alive on the bus. Certain 178 * Weida Tech devices also need this. 179 */ 180 ret = i2c_smbus_read_byte(ihid->client); 181 if (ret < 0) { 182 usleep_range(400, 500); 183 ret = i2c_smbus_read_byte(ihid->client); 184 } 185 return ret < 0 ? ret : 0; 186 } 187 188 static int i2c_hid_xfer(struct i2c_hid *ihid, 189 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len) 190 { 191 struct i2c_client *client = ihid->client; 192 struct i2c_msg msgs[2] = { 0 }; 193 int n = 0; 194 int ret; 195 196 if (send_len) { 197 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", 198 __func__, send_len, send_buf); 199 200 msgs[n].addr = client->addr; 201 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE; 202 msgs[n].len = send_len; 203 msgs[n].buf = send_buf; 204 n++; 205 } 206 207 if (recv_len) { 208 msgs[n].addr = client->addr; 209 msgs[n].flags = (client->flags & I2C_M_TEN) | 210 I2C_M_RD | I2C_M_DMA_SAFE; 211 msgs[n].len = recv_len; 212 msgs[n].buf = recv_buf; 213 n++; 214 } 215 216 ret = i2c_transfer(client->adapter, msgs, n); 217 218 if (ret != n) 219 return ret < 0 ? ret : -EIO; 220 221 return 0; 222 } 223 224 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg, 225 void *buf, size_t len) 226 { 227 guard(mutex)(&ihid->cmd_lock); 228 229 *(__le16 *)ihid->cmdbuf = reg; 230 231 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len); 232 } 233 234 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode, 235 int report_type, int report_id) 236 { 237 size_t length = 0; 238 239 if (report_id < 0x0F) { 240 buf[length++] = report_type << 4 | report_id; 241 buf[length++] = opcode; 242 } else { 243 buf[length++] = report_type << 4 | 0x0F; 244 buf[length++] = opcode; 245 buf[length++] = report_id; 246 } 247 248 return length; 249 } 250 251 static int i2c_hid_get_report(struct i2c_hid *ihid, 252 u8 report_type, u8 report_id, 253 u8 *recv_buf, size_t recv_len) 254 { 255 size_t length = 0; 256 size_t ret_count; 257 int error; 258 259 i2c_hid_dbg(ihid, "%s\n", __func__); 260 261 guard(mutex)(&ihid->cmd_lock); 262 263 /* Command register goes first */ 264 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 265 length += sizeof(__le16); 266 /* Next is GET_REPORT command */ 267 length += i2c_hid_encode_command(ihid->cmdbuf + length, 268 I2C_HID_OPCODE_GET_REPORT, 269 report_type, report_id); 270 /* 271 * Device will send report data through data register. Because 272 * command can be either 2 or 3 bytes destination for the data 273 * register may be not aligned. 274 */ 275 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 276 ihid->cmdbuf + length); 277 length += sizeof(__le16); 278 279 /* 280 * In addition to report data device will supply data length 281 * in the first 2 bytes of the response, so adjust . 282 */ 283 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, 284 ihid->rawbuf, recv_len + sizeof(__le16)); 285 if (error) { 286 dev_err(&ihid->client->dev, 287 "failed to set a report to device: %d\n", error); 288 return error; 289 } 290 291 /* The buffer is sufficiently aligned */ 292 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf); 293 294 /* Check for empty report response */ 295 if (ret_count <= sizeof(__le16)) 296 return 0; 297 298 recv_len = min(recv_len, ret_count - sizeof(__le16)); 299 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len); 300 301 if (report_id && recv_len != 0 && recv_buf[0] != report_id) { 302 dev_err(&ihid->client->dev, 303 "device returned incorrect report (%d vs %d expected)\n", 304 recv_buf[0], report_id); 305 return -EINVAL; 306 } 307 308 return recv_len; 309 } 310 311 static size_t i2c_hid_format_report(u8 *buf, int report_id, 312 const u8 *data, size_t size) 313 { 314 size_t length = sizeof(__le16); /* reserve space to store size */ 315 316 if (report_id) 317 buf[length++] = report_id; 318 319 memcpy(buf + length, data, size); 320 length += size; 321 322 /* Store overall size in the beginning of the buffer */ 323 put_unaligned_le16(length, buf); 324 325 return length; 326 } 327 328 /** 329 * i2c_hid_set_or_send_report: forward an incoming report to the device 330 * @ihid: the i2c hid device 331 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 332 * @report_id: the report ID 333 * @buf: the actual data to transfer, without the report ID 334 * @data_len: size of buf 335 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report 336 */ 337 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid, 338 u8 report_type, u8 report_id, 339 const u8 *buf, size_t data_len, 340 bool do_set) 341 { 342 size_t length = 0; 343 int error; 344 345 i2c_hid_dbg(ihid, "%s\n", __func__); 346 347 if (data_len > ihid->bufsize) 348 return -EINVAL; 349 350 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0) 351 return -ENOSYS; 352 353 guard(mutex)(&ihid->cmd_lock); 354 355 if (do_set) { 356 /* Command register goes first */ 357 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 358 length += sizeof(__le16); 359 /* Next is SET_REPORT command */ 360 length += i2c_hid_encode_command(ihid->cmdbuf + length, 361 I2C_HID_OPCODE_SET_REPORT, 362 report_type, report_id); 363 /* 364 * Report data will go into the data register. Because 365 * command can be either 2 or 3 bytes destination for 366 * the data register may be not aligned. 367 */ 368 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 369 ihid->cmdbuf + length); 370 length += sizeof(__le16); 371 } else { 372 /* 373 * With simple "send report" all data goes into the output 374 * register. 375 */ 376 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister; 377 length += sizeof(__le16); 378 } 379 380 length += i2c_hid_format_report(ihid->cmdbuf + length, 381 report_id, buf, data_len); 382 383 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 384 if (error) { 385 dev_err(&ihid->client->dev, 386 "failed to set a report to device: %d\n", error); 387 return error; 388 } 389 390 return data_len; 391 } 392 393 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state) 394 { 395 size_t length; 396 397 guard(mutex)(&ihid->cmd_lock); 398 399 /* SET_POWER uses command register */ 400 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 401 length = sizeof(__le16); 402 403 /* Now the command itself */ 404 length += i2c_hid_encode_command(ihid->cmdbuf + length, 405 I2C_HID_OPCODE_SET_POWER, 406 0, power_state); 407 408 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 409 } 410 411 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state) 412 { 413 int ret; 414 415 i2c_hid_dbg(ihid, "%s\n", __func__); 416 417 ret = i2c_hid_set_power_command(ihid, power_state); 418 if (ret) 419 dev_err(&ihid->client->dev, 420 "failed to change power setting.\n"); 421 422 /* 423 * The HID over I2C specification states that if a DEVICE needs time 424 * after the PWR_ON request, it should utilise CLOCK stretching. 425 * However, it has been observered that the Windows driver provides a 426 * 1ms sleep between the PWR_ON and RESET requests. 427 * According to Goodix Windows even waits 60 ms after (other?) 428 * PWR_ON requests. Testing has confirmed that several devices 429 * will not work properly without a delay after a PWR_ON request. 430 */ 431 if (!ret && power_state == I2C_HID_PWR_ON) 432 msleep(60); 433 434 return ret; 435 } 436 437 static int i2c_hid_start_hwreset(struct i2c_hid *ihid) 438 { 439 size_t length = 0; 440 int ret; 441 442 i2c_hid_dbg(ihid, "%s\n", __func__); 443 444 /* 445 * This prevents sending feature reports while the device is 446 * being reset. Otherwise we may lose the reset complete 447 * interrupt. 448 */ 449 lockdep_assert_held(&ihid->reset_lock); 450 451 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 452 if (ret) 453 return ret; 454 455 scoped_guard(mutex, &ihid->cmd_lock) { 456 /* Prepare reset command. Command register goes first. */ 457 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 458 length += sizeof(__le16); 459 /* Next is RESET command itself */ 460 length += i2c_hid_encode_command(ihid->cmdbuf + length, 461 I2C_HID_OPCODE_RESET, 0, 0); 462 463 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 464 465 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 466 if (ret) { 467 dev_err(&ihid->client->dev, 468 "failed to reset device: %d\n", ret); 469 break; 470 } 471 472 return 0; 473 } 474 475 /* Clean up if sending reset command failed */ 476 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 477 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 478 return ret; 479 } 480 481 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid) 482 { 483 int ret = 0; 484 485 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 486 487 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) { 488 msleep(100); 489 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 490 } else if (!wait_event_timeout(ihid->wait, 491 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 492 msecs_to_jiffies(1000))) { 493 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n"); 494 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 495 } 496 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 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 return ret; 503 } 504 505 static void i2c_hid_get_input(struct i2c_hid *ihid) 506 { 507 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 508 u16 ret_size; 509 int ret; 510 511 if (size > ihid->bufsize) 512 size = ihid->bufsize; 513 514 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 515 if (ret != size) { 516 if (ret < 0) 517 return; 518 519 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 520 __func__, ret, size); 521 return; 522 } 523 524 /* Receiving buffer is properly aligned */ 525 ret_size = le16_to_cpup((__le16 *)ihid->inbuf); 526 if (!ret_size) { 527 /* host or device initiated RESET completed */ 528 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 529 wake_up(&ihid->wait); 530 return; 531 } 532 533 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) { 534 dev_warn_once(&ihid->client->dev, 535 "%s: IRQ triggered but there's no data\n", 536 __func__); 537 return; 538 } 539 540 if (ret_size > size || ret_size < sizeof(__le16)) { 541 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) { 542 *(__le16 *)ihid->inbuf = cpu_to_le16(size); 543 ret_size = size; 544 } else { 545 dev_err(&ihid->client->dev, 546 "%s: incomplete report (%d/%d)\n", 547 __func__, size, ret_size); 548 return; 549 } 550 } 551 552 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 553 554 if (test_bit(I2C_HID_STARTED, &ihid->flags)) { 555 if (ihid->hid->group != HID_GROUP_RMI) 556 pm_wakeup_event(&ihid->client->dev, 0); 557 558 hid_input_report(ihid->hid, HID_INPUT_REPORT, 559 ihid->inbuf + sizeof(__le16), 560 ret_size - sizeof(__le16), 1); 561 } 562 563 return; 564 } 565 566 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 567 { 568 struct i2c_hid *ihid = dev_id; 569 570 i2c_hid_get_input(ihid); 571 572 return IRQ_HANDLED; 573 } 574 575 static int i2c_hid_get_report_length(struct hid_report *report) 576 { 577 return ((report->size - 1) >> 3) + 1 + 578 report->device->report_enum[report->type].numbered + 2; 579 } 580 581 /* 582 * Traverse the supplied list of reports and find the longest 583 */ 584 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 585 unsigned int *max) 586 { 587 struct hid_report *report; 588 unsigned int size; 589 590 /* We should not rely on wMaxInputLength, as some devices may set it to 591 * a wrong length. */ 592 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 593 size = i2c_hid_get_report_length(report); 594 if (*max < size) 595 *max = size; 596 } 597 } 598 599 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 600 { 601 kfree(ihid->inbuf); 602 kfree(ihid->rawbuf); 603 kfree(ihid->cmdbuf); 604 ihid->inbuf = NULL; 605 ihid->rawbuf = NULL; 606 ihid->cmdbuf = NULL; 607 ihid->bufsize = 0; 608 } 609 610 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 611 { 612 /* 613 * The worst case is computed from the set_report command with a 614 * reportID > 15 and the maximum report length. 615 */ 616 int cmd_len = sizeof(__le16) + /* command register */ 617 sizeof(u8) + /* encoded report type/ID */ 618 sizeof(u8) + /* opcode */ 619 sizeof(u8) + /* optional 3rd byte report ID */ 620 sizeof(__le16) + /* data register */ 621 sizeof(__le16) + /* report data size */ 622 sizeof(u8) + /* report ID if numbered report */ 623 report_size; 624 625 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 626 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 627 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL); 628 629 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) { 630 i2c_hid_free_buffers(ihid); 631 return -ENOMEM; 632 } 633 634 ihid->bufsize = report_size; 635 636 return 0; 637 } 638 639 static int i2c_hid_get_raw_report(struct hid_device *hid, 640 u8 report_type, u8 report_id, 641 u8 *buf, size_t count) 642 { 643 struct i2c_client *client = hid->driver_data; 644 struct i2c_hid *ihid = i2c_get_clientdata(client); 645 int ret_count; 646 647 if (report_type == HID_OUTPUT_REPORT) 648 return -EINVAL; 649 650 /* 651 * In case of unnumbered reports the response from the device will 652 * not have the report ID that the upper layers expect, so we need 653 * to stash it the buffer ourselves and adjust the data size. 654 */ 655 if (!report_id) { 656 buf[0] = 0; 657 buf++; 658 count--; 659 } 660 661 ret_count = i2c_hid_get_report(ihid, 662 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 663 report_id, buf, count); 664 665 if (ret_count > 0 && !report_id) 666 ret_count++; 667 668 return ret_count; 669 } 670 671 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type, 672 const u8 *buf, size_t count, bool do_set) 673 { 674 struct i2c_client *client = hid->driver_data; 675 struct i2c_hid *ihid = i2c_get_clientdata(client); 676 int report_id = buf[0]; 677 int ret; 678 679 if (report_type == HID_INPUT_REPORT) 680 return -EINVAL; 681 682 mutex_lock(&ihid->reset_lock); 683 684 /* 685 * Note that both numbered and unnumbered reports passed here 686 * are supposed to have report ID stored in the 1st byte of the 687 * buffer, so we strip it off unconditionally before passing payload 688 * to i2c_hid_set_or_send_report which takes care of encoding 689 * everything properly. 690 */ 691 ret = i2c_hid_set_or_send_report(ihid, 692 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 693 report_id, buf + 1, count - 1, do_set); 694 695 if (ret >= 0) 696 ret++; /* add report_id to the number of transferred bytes */ 697 698 mutex_unlock(&ihid->reset_lock); 699 700 return ret; 701 } 702 703 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count) 704 { 705 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count, 706 false); 707 } 708 709 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 710 __u8 *buf, size_t len, unsigned char rtype, 711 int reqtype) 712 { 713 switch (reqtype) { 714 case HID_REQ_GET_REPORT: 715 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len); 716 case HID_REQ_SET_REPORT: 717 if (buf[0] != reportnum) 718 return -EINVAL; 719 return i2c_hid_output_raw_report(hid, rtype, buf, len, true); 720 default: 721 return -EIO; 722 } 723 } 724 725 static int i2c_hid_parse(struct hid_device *hid) 726 { 727 struct i2c_client *client = hid->driver_data; 728 struct i2c_hid *ihid = i2c_get_clientdata(client); 729 struct i2c_hid_desc *hdesc = &ihid->hdesc; 730 char *rdesc = NULL, *use_override = NULL; 731 unsigned int rsize; 732 int ret; 733 int tries = 3; 734 735 i2c_hid_dbg(ihid, "entering %s\n", __func__); 736 737 rsize = le16_to_cpu(hdesc->wReportDescLength); 738 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 739 dbg_hid("weird size of report descriptor (%u)\n", rsize); 740 return -EINVAL; 741 } 742 743 mutex_lock(&ihid->reset_lock); 744 do { 745 ret = i2c_hid_start_hwreset(ihid); 746 if (ret == 0) 747 ret = i2c_hid_finish_hwreset(ihid); 748 else 749 msleep(1000); 750 } while (tries-- > 0 && ret); 751 mutex_unlock(&ihid->reset_lock); 752 753 if (ret) 754 return ret; 755 756 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 757 &rsize); 758 759 if (use_override) { 760 rdesc = use_override; 761 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 762 } else { 763 rdesc = kzalloc(rsize, GFP_KERNEL); 764 if (!rdesc) 765 return -ENOMEM; 766 767 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 768 769 ret = i2c_hid_read_register(ihid, 770 ihid->hdesc.wReportDescRegister, 771 rdesc, rsize); 772 if (ret) { 773 hid_err(hid, "reading report descriptor failed\n"); 774 goto out; 775 } 776 } 777 778 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 779 780 ret = hid_parse_report(hid, rdesc, rsize); 781 if (ret) 782 dbg_hid("parsing report descriptor failed\n"); 783 784 out: 785 if (!use_override) 786 kfree(rdesc); 787 788 return ret; 789 } 790 791 static int i2c_hid_start(struct hid_device *hid) 792 { 793 struct i2c_client *client = hid->driver_data; 794 struct i2c_hid *ihid = i2c_get_clientdata(client); 795 int ret; 796 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 797 798 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 799 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 800 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 801 802 if (bufsize > ihid->bufsize) { 803 disable_irq(client->irq); 804 i2c_hid_free_buffers(ihid); 805 806 ret = i2c_hid_alloc_buffers(ihid, bufsize); 807 enable_irq(client->irq); 808 809 if (ret) 810 return ret; 811 } 812 813 return 0; 814 } 815 816 static void i2c_hid_stop(struct hid_device *hid) 817 { 818 hid->claimed = 0; 819 } 820 821 static int i2c_hid_open(struct hid_device *hid) 822 { 823 struct i2c_client *client = hid->driver_data; 824 struct i2c_hid *ihid = i2c_get_clientdata(client); 825 826 set_bit(I2C_HID_STARTED, &ihid->flags); 827 return 0; 828 } 829 830 static void i2c_hid_close(struct hid_device *hid) 831 { 832 struct i2c_client *client = hid->driver_data; 833 struct i2c_hid *ihid = i2c_get_clientdata(client); 834 835 clear_bit(I2C_HID_STARTED, &ihid->flags); 836 } 837 838 static const struct hid_ll_driver i2c_hid_ll_driver = { 839 .parse = i2c_hid_parse, 840 .start = i2c_hid_start, 841 .stop = i2c_hid_stop, 842 .open = i2c_hid_open, 843 .close = i2c_hid_close, 844 .output_report = i2c_hid_output_report, 845 .raw_request = i2c_hid_raw_request, 846 }; 847 848 static int i2c_hid_init_irq(struct i2c_client *client) 849 { 850 struct i2c_hid *ihid = i2c_get_clientdata(client); 851 unsigned long irqflags = 0; 852 int ret; 853 854 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq); 855 856 if (!irq_get_trigger_type(client->irq)) 857 irqflags = IRQF_TRIGGER_LOW; 858 859 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 860 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN, 861 client->name, ihid); 862 if (ret < 0) { 863 dev_warn(&client->dev, 864 "Could not register for %s interrupt, irq = %d," 865 " ret = %d\n", 866 client->name, client->irq, ret); 867 868 return ret; 869 } 870 871 return 0; 872 } 873 874 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 875 { 876 struct i2c_client *client = ihid->client; 877 struct i2c_hid_desc *hdesc = &ihid->hdesc; 878 unsigned int dsize; 879 int error; 880 881 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 882 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 883 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 884 ihid->hdesc = 885 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 886 } else { 887 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 888 error = i2c_hid_read_register(ihid, 889 ihid->wHIDDescRegister, 890 &ihid->hdesc, 891 sizeof(ihid->hdesc)); 892 if (error) { 893 dev_err(&ihid->client->dev, 894 "failed to fetch HID descriptor: %d\n", 895 error); 896 return -ENODEV; 897 } 898 } 899 900 /* Validate the length of HID descriptor, the 4 first bytes: 901 * bytes 0-1 -> length 902 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 903 /* check bcdVersion == 1.0 */ 904 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 905 dev_err(&ihid->client->dev, 906 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 907 le16_to_cpu(hdesc->bcdVersion)); 908 return -ENODEV; 909 } 910 911 /* Descriptor length should be 30 bytes as per the specification */ 912 dsize = le16_to_cpu(hdesc->wHIDDescLength); 913 if (dsize != sizeof(struct i2c_hid_desc)) { 914 dev_err(&ihid->client->dev, 915 "weird size of HID descriptor (%u)\n", dsize); 916 return -ENODEV; 917 } 918 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc); 919 return 0; 920 } 921 922 static int i2c_hid_core_power_up(struct i2c_hid *ihid) 923 { 924 if (!ihid->ops->power_up) 925 return 0; 926 927 return ihid->ops->power_up(ihid->ops); 928 } 929 930 static void i2c_hid_core_power_down(struct i2c_hid *ihid) 931 { 932 if (!ihid->ops->power_down) 933 return; 934 935 ihid->ops->power_down(ihid->ops); 936 } 937 938 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid) 939 { 940 if (!ihid->ops->shutdown_tail) 941 return; 942 943 ihid->ops->shutdown_tail(ihid->ops); 944 } 945 946 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff) 947 { 948 struct i2c_client *client = ihid->client; 949 struct hid_device *hid = ihid->hid; 950 int ret; 951 952 ret = hid_driver_suspend(hid, PMSG_SUSPEND); 953 if (ret < 0) 954 return ret; 955 956 /* Save some power */ 957 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND)) 958 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 959 960 disable_irq(client->irq); 961 962 if (force_poweroff || !device_may_wakeup(&client->dev)) 963 i2c_hid_core_power_down(ihid); 964 965 return 0; 966 } 967 968 static int i2c_hid_core_resume(struct i2c_hid *ihid) 969 { 970 struct i2c_client *client = ihid->client; 971 struct hid_device *hid = ihid->hid; 972 int ret; 973 974 if (!device_may_wakeup(&client->dev)) 975 i2c_hid_core_power_up(ihid); 976 977 enable_irq(client->irq); 978 979 /* Make sure the device is awake on the bus */ 980 ret = i2c_hid_probe_address(ihid); 981 if (ret < 0) { 982 dev_err(&client->dev, "nothing at address after resume: %d\n", 983 ret); 984 return -ENXIO; 985 } 986 987 /* On Goodix 27c6:0d42 wait extra time before device wakeup. 988 * It's not clear why but if we send wakeup too early, the device will 989 * never trigger input interrupts. 990 */ 991 if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME) 992 msleep(1500); 993 994 /* Instead of resetting device, simply powers the device on. This 995 * solves "incomplete reports" on Raydium devices 2386:3118 and 996 * 2386:4B33 and fixes various SIS touchscreens no longer sending 997 * data after a suspend/resume. 998 * 999 * However some ALPS touchpads generate IRQ storm without reset, so 1000 * let's still reset them here. 1001 */ 1002 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) { 1003 mutex_lock(&ihid->reset_lock); 1004 ret = i2c_hid_start_hwreset(ihid); 1005 if (ret == 0) 1006 ret = i2c_hid_finish_hwreset(ihid); 1007 mutex_unlock(&ihid->reset_lock); 1008 } else { 1009 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 1010 } 1011 1012 if (ret) 1013 return ret; 1014 1015 return hid_driver_reset_resume(hid); 1016 } 1017 1018 /* 1019 * Check that the device exists and parse the HID descriptor. 1020 */ 1021 static int __i2c_hid_core_probe(struct i2c_hid *ihid) 1022 { 1023 struct i2c_client *client = ihid->client; 1024 struct hid_device *hid = ihid->hid; 1025 int ret; 1026 1027 ret = i2c_hid_probe_address(ihid); 1028 if (ret < 0) { 1029 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret); 1030 return -ENXIO; 1031 } 1032 1033 ret = i2c_hid_fetch_hid_descriptor(ihid); 1034 if (ret < 0) { 1035 dev_err(&client->dev, 1036 "Failed to fetch the HID Descriptor\n"); 1037 return ret; 1038 } 1039 1040 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1041 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1042 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1043 1044 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor, 1045 hid->product); 1046 1047 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", 1048 client->name, (u16)hid->vendor, (u16)hid->product); 1049 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1050 1051 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1052 1053 return 0; 1054 } 1055 1056 static int i2c_hid_core_register_hid(struct i2c_hid *ihid) 1057 { 1058 struct i2c_client *client = ihid->client; 1059 struct hid_device *hid = ihid->hid; 1060 int ret; 1061 1062 enable_irq(client->irq); 1063 1064 ret = hid_add_device(hid); 1065 if (ret) { 1066 if (ret != -ENODEV) 1067 hid_err(client, "can't add hid device: %d\n", ret); 1068 disable_irq(client->irq); 1069 return ret; 1070 } 1071 1072 return 0; 1073 } 1074 1075 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid) 1076 { 1077 int ret; 1078 1079 ret = i2c_hid_core_power_up(ihid); 1080 if (ret) 1081 return ret; 1082 1083 ret = __i2c_hid_core_probe(ihid); 1084 if (ret) 1085 goto err_power_down; 1086 1087 ret = i2c_hid_core_register_hid(ihid); 1088 if (ret) 1089 goto err_power_down; 1090 1091 return 0; 1092 1093 err_power_down: 1094 i2c_hid_core_power_down(ihid); 1095 1096 return ret; 1097 } 1098 1099 static void ihid_core_panel_prepare_work(struct work_struct *work) 1100 { 1101 struct i2c_hid *ihid = container_of(work, struct i2c_hid, 1102 panel_follower_prepare_work); 1103 struct hid_device *hid = ihid->hid; 1104 int ret; 1105 1106 /* 1107 * hid->version is set on the first power up. If it's still zero then 1108 * this is the first power on so we should perform initial power up 1109 * steps. 1110 */ 1111 if (!hid->version) 1112 ret = i2c_hid_core_probe_panel_follower(ihid); 1113 else 1114 ret = i2c_hid_core_resume(ihid); 1115 1116 if (ret) 1117 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret); 1118 else 1119 WRITE_ONCE(ihid->prepare_work_finished, true); 1120 1121 /* 1122 * The work APIs provide a number of memory ordering guarantees 1123 * including one that says that memory writes before schedule_work() 1124 * are always visible to the work function, but they don't appear to 1125 * guarantee that a write that happened in the work is visible after 1126 * cancel_work_sync(). We'll add a write memory barrier here to match 1127 * with i2c_hid_core_panel_unpreparing() to ensure that our write to 1128 * prepare_work_finished is visible there. 1129 */ 1130 smp_wmb(); 1131 } 1132 1133 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower) 1134 { 1135 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); 1136 1137 /* 1138 * Powering on a touchscreen can be a slow process. Queue the work to 1139 * the system workqueue so we don't block the panel's power up. 1140 */ 1141 WRITE_ONCE(ihid->prepare_work_finished, false); 1142 schedule_work(&ihid->panel_follower_prepare_work); 1143 1144 return 0; 1145 } 1146 1147 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower) 1148 { 1149 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); 1150 1151 cancel_work_sync(&ihid->panel_follower_prepare_work); 1152 1153 /* Match with ihid_core_panel_prepare_work() */ 1154 smp_rmb(); 1155 if (!READ_ONCE(ihid->prepare_work_finished)) 1156 return 0; 1157 1158 return i2c_hid_core_suspend(ihid, true); 1159 } 1160 1161 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = { 1162 .panel_prepared = i2c_hid_core_panel_prepared, 1163 .panel_unpreparing = i2c_hid_core_panel_unpreparing, 1164 }; 1165 1166 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid) 1167 { 1168 struct device *dev = &ihid->client->dev; 1169 int ret; 1170 1171 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs; 1172 1173 /* 1174 * If we're not in control of our own power up/power down then we can't 1175 * do the logic to manage wakeups. Give a warning if a user thought 1176 * that was possible then force the capability off. 1177 */ 1178 if (device_can_wakeup(dev)) { 1179 dev_warn(dev, "Can't wakeup if following panel\n"); 1180 device_set_wakeup_capable(dev, false); 1181 } 1182 1183 ret = drm_panel_add_follower(dev, &ihid->panel_follower); 1184 if (ret) 1185 return ret; 1186 1187 return 0; 1188 } 1189 1190 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, 1191 u16 hid_descriptor_address, u32 quirks) 1192 { 1193 int ret; 1194 struct i2c_hid *ihid; 1195 struct hid_device *hid; 1196 1197 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 1198 1199 if (!client->irq) { 1200 dev_err(&client->dev, 1201 "HID over i2c has not been provided an Int IRQ\n"); 1202 return -EINVAL; 1203 } 1204 1205 if (client->irq < 0) { 1206 if (client->irq != -EPROBE_DEFER) 1207 dev_err(&client->dev, 1208 "HID over i2c doesn't have a valid IRQ\n"); 1209 return client->irq; 1210 } 1211 1212 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1213 if (!ihid) 1214 return -ENOMEM; 1215 1216 i2c_set_clientdata(client, ihid); 1217 1218 ihid->ops = ops; 1219 ihid->client = client; 1220 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address); 1221 ihid->is_panel_follower = drm_is_panel_follower(&client->dev); 1222 1223 init_waitqueue_head(&ihid->wait); 1224 mutex_init(&ihid->cmd_lock); 1225 mutex_init(&ihid->reset_lock); 1226 INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work); 1227 1228 /* we need to allocate the command buffer without knowing the maximum 1229 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1230 * real computation later. */ 1231 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1232 if (ret < 0) 1233 return ret; 1234 device_enable_async_suspend(&client->dev); 1235 1236 hid = hid_allocate_device(); 1237 if (IS_ERR(hid)) { 1238 ret = PTR_ERR(hid); 1239 goto err_free_buffers; 1240 } 1241 1242 ihid->hid = hid; 1243 1244 hid->driver_data = client; 1245 hid->ll_driver = &i2c_hid_ll_driver; 1246 hid->dev.parent = &client->dev; 1247 hid->bus = BUS_I2C; 1248 hid->initial_quirks = quirks; 1249 1250 /* Power on and probe unless device is a panel follower. */ 1251 if (!ihid->is_panel_follower) { 1252 ret = i2c_hid_core_power_up(ihid); 1253 if (ret < 0) 1254 goto err_destroy_device; 1255 1256 ret = __i2c_hid_core_probe(ihid); 1257 if (ret < 0) 1258 goto err_power_down; 1259 } 1260 1261 ret = i2c_hid_init_irq(client); 1262 if (ret < 0) 1263 goto err_power_down; 1264 1265 /* 1266 * If we're a panel follower, we'll register when the panel turns on; 1267 * otherwise we do it right away. 1268 */ 1269 if (ihid->is_panel_follower) 1270 ret = i2c_hid_core_register_panel_follower(ihid); 1271 else 1272 ret = i2c_hid_core_register_hid(ihid); 1273 if (ret) 1274 goto err_free_irq; 1275 1276 return 0; 1277 1278 err_free_irq: 1279 free_irq(client->irq, ihid); 1280 err_power_down: 1281 if (!ihid->is_panel_follower) 1282 i2c_hid_core_power_down(ihid); 1283 err_destroy_device: 1284 hid_destroy_device(hid); 1285 err_free_buffers: 1286 i2c_hid_free_buffers(ihid); 1287 1288 return ret; 1289 } 1290 EXPORT_SYMBOL_GPL(i2c_hid_core_probe); 1291 1292 void i2c_hid_core_remove(struct i2c_client *client) 1293 { 1294 struct i2c_hid *ihid = i2c_get_clientdata(client); 1295 struct hid_device *hid; 1296 1297 /* 1298 * If we're a follower, the act of unfollowing will cause us to be 1299 * powered down. Otherwise we need to manually do it. 1300 */ 1301 if (ihid->is_panel_follower) 1302 drm_panel_remove_follower(&ihid->panel_follower); 1303 else 1304 i2c_hid_core_suspend(ihid, true); 1305 1306 hid = ihid->hid; 1307 hid_destroy_device(hid); 1308 1309 free_irq(client->irq, ihid); 1310 1311 if (ihid->bufsize) 1312 i2c_hid_free_buffers(ihid); 1313 } 1314 EXPORT_SYMBOL_GPL(i2c_hid_core_remove); 1315 1316 void i2c_hid_core_shutdown(struct i2c_client *client) 1317 { 1318 struct i2c_hid *ihid = i2c_get_clientdata(client); 1319 1320 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 1321 free_irq(client->irq, ihid); 1322 1323 i2c_hid_core_shutdown_tail(ihid); 1324 } 1325 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown); 1326 1327 static int i2c_hid_core_pm_suspend(struct device *dev) 1328 { 1329 struct i2c_client *client = to_i2c_client(dev); 1330 struct i2c_hid *ihid = i2c_get_clientdata(client); 1331 1332 if (ihid->is_panel_follower) 1333 return 0; 1334 1335 return i2c_hid_core_suspend(ihid, false); 1336 } 1337 1338 static int i2c_hid_core_pm_resume(struct device *dev) 1339 { 1340 struct i2c_client *client = to_i2c_client(dev); 1341 struct i2c_hid *ihid = i2c_get_clientdata(client); 1342 1343 if (ihid->is_panel_follower) 1344 return 0; 1345 1346 return i2c_hid_core_resume(ihid); 1347 } 1348 1349 const struct dev_pm_ops i2c_hid_core_pm = { 1350 SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume) 1351 }; 1352 EXPORT_SYMBOL_GPL(i2c_hid_core_pm); 1353 1354 MODULE_DESCRIPTION("HID over I2C core driver"); 1355 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1356 MODULE_LICENSE("GPL"); 1357