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 <asm/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 54 /* Command opcodes */ 55 #define I2C_HID_OPCODE_RESET 0x01 56 #define I2C_HID_OPCODE_GET_REPORT 0x02 57 #define I2C_HID_OPCODE_SET_REPORT 0x03 58 #define I2C_HID_OPCODE_GET_IDLE 0x04 59 #define I2C_HID_OPCODE_SET_IDLE 0x05 60 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06 61 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07 62 #define I2C_HID_OPCODE_SET_POWER 0x08 63 64 /* flags */ 65 #define I2C_HID_STARTED 0 66 #define I2C_HID_RESET_PENDING 1 67 68 #define I2C_HID_PWR_ON 0x00 69 #define I2C_HID_PWR_SLEEP 0x01 70 71 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__) 72 73 struct i2c_hid_desc { 74 __le16 wHIDDescLength; 75 __le16 bcdVersion; 76 __le16 wReportDescLength; 77 __le16 wReportDescRegister; 78 __le16 wInputRegister; 79 __le16 wMaxInputLength; 80 __le16 wOutputRegister; 81 __le16 wMaxOutputLength; 82 __le16 wCommandRegister; 83 __le16 wDataRegister; 84 __le16 wVendorID; 85 __le16 wProductID; 86 __le16 wVersionID; 87 __le32 reserved; 88 } __packed; 89 90 /* The main device structure */ 91 struct i2c_hid { 92 struct i2c_client *client; /* i2c client */ 93 struct hid_device *hid; /* pointer to corresponding HID dev */ 94 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 95 __le16 wHIDDescRegister; /* location of the i2c 96 * register of the HID 97 * descriptor. */ 98 unsigned int bufsize; /* i2c buffer size */ 99 u8 *inbuf; /* Input buffer */ 100 u8 *rawbuf; /* Raw Input buffer */ 101 u8 *cmdbuf; /* Command buffer */ 102 103 unsigned long flags; /* device flags */ 104 unsigned long quirks; /* Various quirks */ 105 106 wait_queue_head_t wait; /* For waiting the interrupt */ 107 108 struct mutex reset_lock; 109 110 struct i2chid_ops *ops; 111 struct drm_panel_follower panel_follower; 112 struct work_struct panel_follower_prepare_work; 113 bool is_panel_follower; 114 bool prepare_work_finished; 115 }; 116 117 static const struct i2c_hid_quirks { 118 __u16 idVendor; 119 __u16 idProduct; 120 __u32 quirks; 121 } i2c_hid_quirks[] = { 122 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 123 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 124 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15, 125 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 126 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118, 127 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 128 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID, 129 I2C_HID_QUIRK_RESET_ON_RESUME }, 130 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393, 131 I2C_HID_QUIRK_RESET_ON_RESUME }, 132 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720, 133 I2C_HID_QUIRK_BAD_INPUT_SIZE }, 134 { I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063, 135 I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND }, 136 /* 137 * Sending the wakeup after reset actually break ELAN touchscreen controller 138 */ 139 { USB_VENDOR_ID_ELAN, HID_ANY_ID, 140 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET | 141 I2C_HID_QUIRK_BOGUS_IRQ }, 142 { 0, 0 } 143 }; 144 145 /* 146 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device 147 * @idVendor: the 16-bit vendor ID 148 * @idProduct: the 16-bit product ID 149 * 150 * Returns: a u32 quirks value. 151 */ 152 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) 153 { 154 u32 quirks = 0; 155 int n; 156 157 for (n = 0; i2c_hid_quirks[n].idVendor; n++) 158 if (i2c_hid_quirks[n].idVendor == idVendor && 159 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || 160 i2c_hid_quirks[n].idProduct == idProduct)) 161 quirks = i2c_hid_quirks[n].quirks; 162 163 return quirks; 164 } 165 166 static int i2c_hid_xfer(struct i2c_hid *ihid, 167 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len) 168 { 169 struct i2c_client *client = ihid->client; 170 struct i2c_msg msgs[2] = { 0 }; 171 int n = 0; 172 int ret; 173 174 if (send_len) { 175 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", 176 __func__, send_len, send_buf); 177 178 msgs[n].addr = client->addr; 179 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE; 180 msgs[n].len = send_len; 181 msgs[n].buf = send_buf; 182 n++; 183 } 184 185 if (recv_len) { 186 msgs[n].addr = client->addr; 187 msgs[n].flags = (client->flags & I2C_M_TEN) | 188 I2C_M_RD | I2C_M_DMA_SAFE; 189 msgs[n].len = recv_len; 190 msgs[n].buf = recv_buf; 191 n++; 192 } 193 194 ret = i2c_transfer(client->adapter, msgs, n); 195 196 if (ret != n) 197 return ret < 0 ? ret : -EIO; 198 199 return 0; 200 } 201 202 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg, 203 void *buf, size_t len) 204 { 205 *(__le16 *)ihid->cmdbuf = reg; 206 207 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len); 208 } 209 210 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode, 211 int report_type, int report_id) 212 { 213 size_t length = 0; 214 215 if (report_id < 0x0F) { 216 buf[length++] = report_type << 4 | report_id; 217 buf[length++] = opcode; 218 } else { 219 buf[length++] = report_type << 4 | 0x0F; 220 buf[length++] = opcode; 221 buf[length++] = report_id; 222 } 223 224 return length; 225 } 226 227 static int i2c_hid_get_report(struct i2c_hid *ihid, 228 u8 report_type, u8 report_id, 229 u8 *recv_buf, size_t recv_len) 230 { 231 size_t length = 0; 232 size_t ret_count; 233 int error; 234 235 i2c_hid_dbg(ihid, "%s\n", __func__); 236 237 /* Command register goes first */ 238 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 239 length += sizeof(__le16); 240 /* Next is GET_REPORT command */ 241 length += i2c_hid_encode_command(ihid->cmdbuf + length, 242 I2C_HID_OPCODE_GET_REPORT, 243 report_type, report_id); 244 /* 245 * Device will send report data through data register. Because 246 * command can be either 2 or 3 bytes destination for the data 247 * register may be not aligned. 248 */ 249 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 250 ihid->cmdbuf + length); 251 length += sizeof(__le16); 252 253 /* 254 * In addition to report data device will supply data length 255 * in the first 2 bytes of the response, so adjust . 256 */ 257 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, 258 ihid->rawbuf, recv_len + sizeof(__le16)); 259 if (error) { 260 dev_err(&ihid->client->dev, 261 "failed to set a report to device: %d\n", error); 262 return error; 263 } 264 265 /* The buffer is sufficiently aligned */ 266 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf); 267 268 /* Check for empty report response */ 269 if (ret_count <= sizeof(__le16)) 270 return 0; 271 272 recv_len = min(recv_len, ret_count - sizeof(__le16)); 273 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len); 274 275 if (report_id && recv_len != 0 && recv_buf[0] != report_id) { 276 dev_err(&ihid->client->dev, 277 "device returned incorrect report (%d vs %d expected)\n", 278 recv_buf[0], report_id); 279 return -EINVAL; 280 } 281 282 return recv_len; 283 } 284 285 static size_t i2c_hid_format_report(u8 *buf, int report_id, 286 const u8 *data, size_t size) 287 { 288 size_t length = sizeof(__le16); /* reserve space to store size */ 289 290 if (report_id) 291 buf[length++] = report_id; 292 293 memcpy(buf + length, data, size); 294 length += size; 295 296 /* Store overall size in the beginning of the buffer */ 297 put_unaligned_le16(length, buf); 298 299 return length; 300 } 301 302 /** 303 * i2c_hid_set_or_send_report: forward an incoming report to the device 304 * @ihid: the i2c hid device 305 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 306 * @report_id: the report ID 307 * @buf: the actual data to transfer, without the report ID 308 * @data_len: size of buf 309 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report 310 */ 311 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid, 312 u8 report_type, u8 report_id, 313 const u8 *buf, size_t data_len, 314 bool do_set) 315 { 316 size_t length = 0; 317 int error; 318 319 i2c_hid_dbg(ihid, "%s\n", __func__); 320 321 if (data_len > ihid->bufsize) 322 return -EINVAL; 323 324 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0) 325 return -ENOSYS; 326 327 if (do_set) { 328 /* Command register goes first */ 329 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 330 length += sizeof(__le16); 331 /* Next is SET_REPORT command */ 332 length += i2c_hid_encode_command(ihid->cmdbuf + length, 333 I2C_HID_OPCODE_SET_REPORT, 334 report_type, report_id); 335 /* 336 * Report data will go into the data register. Because 337 * command can be either 2 or 3 bytes destination for 338 * the data register may be not aligned. 339 */ 340 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 341 ihid->cmdbuf + length); 342 length += sizeof(__le16); 343 } else { 344 /* 345 * With simple "send report" all data goes into the output 346 * register. 347 */ 348 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister; 349 length += sizeof(__le16); 350 } 351 352 length += i2c_hid_format_report(ihid->cmdbuf + length, 353 report_id, buf, data_len); 354 355 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 356 if (error) { 357 dev_err(&ihid->client->dev, 358 "failed to set a report to device: %d\n", error); 359 return error; 360 } 361 362 return data_len; 363 } 364 365 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state) 366 { 367 size_t length; 368 369 /* SET_POWER uses command register */ 370 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 371 length = sizeof(__le16); 372 373 /* Now the command itself */ 374 length += i2c_hid_encode_command(ihid->cmdbuf + length, 375 I2C_HID_OPCODE_SET_POWER, 376 0, power_state); 377 378 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 379 } 380 381 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state) 382 { 383 int ret; 384 385 i2c_hid_dbg(ihid, "%s\n", __func__); 386 387 /* 388 * Some devices require to send a command to wakeup before power on. 389 * The call will get a return value (EREMOTEIO) but device will be 390 * triggered and activated. After that, it goes like a normal device. 391 */ 392 if (power_state == I2C_HID_PWR_ON) { 393 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON); 394 395 /* Device was already activated */ 396 if (!ret) 397 goto set_pwr_exit; 398 } 399 400 ret = i2c_hid_set_power_command(ihid, power_state); 401 if (ret) 402 dev_err(&ihid->client->dev, 403 "failed to change power setting.\n"); 404 405 set_pwr_exit: 406 407 /* 408 * The HID over I2C specification states that if a DEVICE needs time 409 * after the PWR_ON request, it should utilise CLOCK stretching. 410 * However, it has been observered that the Windows driver provides a 411 * 1ms sleep between the PWR_ON and RESET requests. 412 * According to Goodix Windows even waits 60 ms after (other?) 413 * PWR_ON requests. Testing has confirmed that several devices 414 * will not work properly without a delay after a PWR_ON request. 415 */ 416 if (!ret && power_state == I2C_HID_PWR_ON) 417 msleep(60); 418 419 return ret; 420 } 421 422 static int i2c_hid_execute_reset(struct i2c_hid *ihid) 423 { 424 size_t length = 0; 425 int ret; 426 427 i2c_hid_dbg(ihid, "resetting...\n"); 428 429 /* Prepare reset command. Command register goes first. */ 430 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 431 length += sizeof(__le16); 432 /* Next is RESET command itself */ 433 length += i2c_hid_encode_command(ihid->cmdbuf + length, 434 I2C_HID_OPCODE_RESET, 0, 0); 435 436 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 437 438 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 439 if (ret) { 440 dev_err(&ihid->client->dev, "failed to reset device.\n"); 441 goto out; 442 } 443 444 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) { 445 msleep(100); 446 goto out; 447 } 448 449 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 450 if (!wait_event_timeout(ihid->wait, 451 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 452 msecs_to_jiffies(5000))) { 453 ret = -ENODATA; 454 goto out; 455 } 456 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 457 458 out: 459 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 460 return ret; 461 } 462 463 static int i2c_hid_hwreset(struct i2c_hid *ihid) 464 { 465 int ret; 466 467 i2c_hid_dbg(ihid, "%s\n", __func__); 468 469 /* 470 * This prevents sending feature reports while the device is 471 * being reset. Otherwise we may lose the reset complete 472 * interrupt. 473 */ 474 mutex_lock(&ihid->reset_lock); 475 476 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 477 if (ret) 478 goto out_unlock; 479 480 ret = i2c_hid_execute_reset(ihid); 481 if (ret) { 482 dev_err(&ihid->client->dev, 483 "failed to reset device: %d\n", ret); 484 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 485 goto out_unlock; 486 } 487 488 /* At least some SIS devices need this after reset */ 489 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET)) 490 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 491 492 out_unlock: 493 mutex_unlock(&ihid->reset_lock); 494 return ret; 495 } 496 497 static void i2c_hid_get_input(struct i2c_hid *ihid) 498 { 499 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 500 u16 ret_size; 501 int ret; 502 503 if (size > ihid->bufsize) 504 size = ihid->bufsize; 505 506 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 507 if (ret != size) { 508 if (ret < 0) 509 return; 510 511 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 512 __func__, ret, size); 513 return; 514 } 515 516 /* Receiving buffer is properly aligned */ 517 ret_size = le16_to_cpup((__le16 *)ihid->inbuf); 518 if (!ret_size) { 519 /* host or device initiated RESET completed */ 520 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 521 wake_up(&ihid->wait); 522 return; 523 } 524 525 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) { 526 dev_warn_once(&ihid->client->dev, 527 "%s: IRQ triggered but there's no data\n", 528 __func__); 529 return; 530 } 531 532 if (ret_size > size || ret_size < sizeof(__le16)) { 533 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) { 534 *(__le16 *)ihid->inbuf = cpu_to_le16(size); 535 ret_size = size; 536 } else { 537 dev_err(&ihid->client->dev, 538 "%s: incomplete report (%d/%d)\n", 539 __func__, size, ret_size); 540 return; 541 } 542 } 543 544 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 545 546 if (test_bit(I2C_HID_STARTED, &ihid->flags)) { 547 if (ihid->hid->group != HID_GROUP_RMI) 548 pm_wakeup_event(&ihid->client->dev, 0); 549 550 hid_input_report(ihid->hid, HID_INPUT_REPORT, 551 ihid->inbuf + sizeof(__le16), 552 ret_size - sizeof(__le16), 1); 553 } 554 555 return; 556 } 557 558 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 559 { 560 struct i2c_hid *ihid = dev_id; 561 562 i2c_hid_get_input(ihid); 563 564 return IRQ_HANDLED; 565 } 566 567 static int i2c_hid_get_report_length(struct hid_report *report) 568 { 569 return ((report->size - 1) >> 3) + 1 + 570 report->device->report_enum[report->type].numbered + 2; 571 } 572 573 /* 574 * Traverse the supplied list of reports and find the longest 575 */ 576 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 577 unsigned int *max) 578 { 579 struct hid_report *report; 580 unsigned int size; 581 582 /* We should not rely on wMaxInputLength, as some devices may set it to 583 * a wrong length. */ 584 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 585 size = i2c_hid_get_report_length(report); 586 if (*max < size) 587 *max = size; 588 } 589 } 590 591 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 592 { 593 kfree(ihid->inbuf); 594 kfree(ihid->rawbuf); 595 kfree(ihid->cmdbuf); 596 ihid->inbuf = NULL; 597 ihid->rawbuf = NULL; 598 ihid->cmdbuf = NULL; 599 ihid->bufsize = 0; 600 } 601 602 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 603 { 604 /* 605 * The worst case is computed from the set_report command with a 606 * reportID > 15 and the maximum report length. 607 */ 608 int cmd_len = sizeof(__le16) + /* command register */ 609 sizeof(u8) + /* encoded report type/ID */ 610 sizeof(u8) + /* opcode */ 611 sizeof(u8) + /* optional 3rd byte report ID */ 612 sizeof(__le16) + /* data register */ 613 sizeof(__le16) + /* report data size */ 614 sizeof(u8) + /* report ID if numbered report */ 615 report_size; 616 617 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 618 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 619 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL); 620 621 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) { 622 i2c_hid_free_buffers(ihid); 623 return -ENOMEM; 624 } 625 626 ihid->bufsize = report_size; 627 628 return 0; 629 } 630 631 static int i2c_hid_get_raw_report(struct hid_device *hid, 632 u8 report_type, u8 report_id, 633 u8 *buf, size_t count) 634 { 635 struct i2c_client *client = hid->driver_data; 636 struct i2c_hid *ihid = i2c_get_clientdata(client); 637 int ret_count; 638 639 if (report_type == HID_OUTPUT_REPORT) 640 return -EINVAL; 641 642 /* 643 * In case of unnumbered reports the response from the device will 644 * not have the report ID that the upper layers expect, so we need 645 * to stash it the buffer ourselves and adjust the data size. 646 */ 647 if (!report_id) { 648 buf[0] = 0; 649 buf++; 650 count--; 651 } 652 653 ret_count = i2c_hid_get_report(ihid, 654 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 655 report_id, buf, count); 656 657 if (ret_count > 0 && !report_id) 658 ret_count++; 659 660 return ret_count; 661 } 662 663 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type, 664 const u8 *buf, size_t count, bool do_set) 665 { 666 struct i2c_client *client = hid->driver_data; 667 struct i2c_hid *ihid = i2c_get_clientdata(client); 668 int report_id = buf[0]; 669 int ret; 670 671 if (report_type == HID_INPUT_REPORT) 672 return -EINVAL; 673 674 mutex_lock(&ihid->reset_lock); 675 676 /* 677 * Note that both numbered and unnumbered reports passed here 678 * are supposed to have report ID stored in the 1st byte of the 679 * buffer, so we strip it off unconditionally before passing payload 680 * to i2c_hid_set_or_send_report which takes care of encoding 681 * everything properly. 682 */ 683 ret = i2c_hid_set_or_send_report(ihid, 684 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 685 report_id, buf + 1, count - 1, do_set); 686 687 if (ret >= 0) 688 ret++; /* add report_id to the number of transferred bytes */ 689 690 mutex_unlock(&ihid->reset_lock); 691 692 return ret; 693 } 694 695 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count) 696 { 697 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count, 698 false); 699 } 700 701 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 702 __u8 *buf, size_t len, unsigned char rtype, 703 int reqtype) 704 { 705 switch (reqtype) { 706 case HID_REQ_GET_REPORT: 707 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len); 708 case HID_REQ_SET_REPORT: 709 if (buf[0] != reportnum) 710 return -EINVAL; 711 return i2c_hid_output_raw_report(hid, rtype, buf, len, true); 712 default: 713 return -EIO; 714 } 715 } 716 717 static int i2c_hid_parse(struct hid_device *hid) 718 { 719 struct i2c_client *client = hid->driver_data; 720 struct i2c_hid *ihid = i2c_get_clientdata(client); 721 struct i2c_hid_desc *hdesc = &ihid->hdesc; 722 unsigned int rsize; 723 char *rdesc; 724 int ret; 725 int tries = 3; 726 char *use_override; 727 728 i2c_hid_dbg(ihid, "entering %s\n", __func__); 729 730 rsize = le16_to_cpu(hdesc->wReportDescLength); 731 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 732 dbg_hid("weird size of report descriptor (%u)\n", rsize); 733 return -EINVAL; 734 } 735 736 do { 737 ret = i2c_hid_hwreset(ihid); 738 if (ret) 739 msleep(1000); 740 } while (tries-- > 0 && ret); 741 742 if (ret) 743 return ret; 744 745 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 746 &rsize); 747 748 if (use_override) { 749 rdesc = use_override; 750 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 751 } else { 752 rdesc = kzalloc(rsize, GFP_KERNEL); 753 754 if (!rdesc) { 755 dbg_hid("couldn't allocate rdesc memory\n"); 756 return -ENOMEM; 757 } 758 759 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 760 761 ret = i2c_hid_read_register(ihid, 762 ihid->hdesc.wReportDescRegister, 763 rdesc, rsize); 764 if (ret) { 765 hid_err(hid, "reading report descriptor failed\n"); 766 kfree(rdesc); 767 return -EIO; 768 } 769 } 770 771 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 772 773 ret = hid_parse_report(hid, rdesc, rsize); 774 if (!use_override) 775 kfree(rdesc); 776 777 if (ret) { 778 dbg_hid("parsing report descriptor failed\n"); 779 return ret; 780 } 781 782 return 0; 783 } 784 785 static int i2c_hid_start(struct hid_device *hid) 786 { 787 struct i2c_client *client = hid->driver_data; 788 struct i2c_hid *ihid = i2c_get_clientdata(client); 789 int ret; 790 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 791 792 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 793 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 794 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 795 796 if (bufsize > ihid->bufsize) { 797 disable_irq(client->irq); 798 i2c_hid_free_buffers(ihid); 799 800 ret = i2c_hid_alloc_buffers(ihid, bufsize); 801 enable_irq(client->irq); 802 803 if (ret) 804 return ret; 805 } 806 807 return 0; 808 } 809 810 static void i2c_hid_stop(struct hid_device *hid) 811 { 812 hid->claimed = 0; 813 } 814 815 static int i2c_hid_open(struct hid_device *hid) 816 { 817 struct i2c_client *client = hid->driver_data; 818 struct i2c_hid *ihid = i2c_get_clientdata(client); 819 820 set_bit(I2C_HID_STARTED, &ihid->flags); 821 return 0; 822 } 823 824 static void i2c_hid_close(struct hid_device *hid) 825 { 826 struct i2c_client *client = hid->driver_data; 827 struct i2c_hid *ihid = i2c_get_clientdata(client); 828 829 clear_bit(I2C_HID_STARTED, &ihid->flags); 830 } 831 832 static const struct hid_ll_driver i2c_hid_ll_driver = { 833 .parse = i2c_hid_parse, 834 .start = i2c_hid_start, 835 .stop = i2c_hid_stop, 836 .open = i2c_hid_open, 837 .close = i2c_hid_close, 838 .output_report = i2c_hid_output_report, 839 .raw_request = i2c_hid_raw_request, 840 }; 841 842 static int i2c_hid_init_irq(struct i2c_client *client) 843 { 844 struct i2c_hid *ihid = i2c_get_clientdata(client); 845 unsigned long irqflags = 0; 846 int ret; 847 848 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq); 849 850 if (!irq_get_trigger_type(client->irq)) 851 irqflags = IRQF_TRIGGER_LOW; 852 853 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 854 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN, 855 client->name, ihid); 856 if (ret < 0) { 857 dev_warn(&client->dev, 858 "Could not register for %s interrupt, irq = %d," 859 " ret = %d\n", 860 client->name, client->irq, ret); 861 862 return ret; 863 } 864 865 return 0; 866 } 867 868 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 869 { 870 struct i2c_client *client = ihid->client; 871 struct i2c_hid_desc *hdesc = &ihid->hdesc; 872 unsigned int dsize; 873 int error; 874 875 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 876 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 877 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 878 ihid->hdesc = 879 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 880 } else { 881 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 882 error = i2c_hid_read_register(ihid, 883 ihid->wHIDDescRegister, 884 &ihid->hdesc, 885 sizeof(ihid->hdesc)); 886 if (error) { 887 dev_err(&ihid->client->dev, 888 "failed to fetch HID descriptor: %d\n", 889 error); 890 return -ENODEV; 891 } 892 } 893 894 /* Validate the length of HID descriptor, the 4 first bytes: 895 * bytes 0-1 -> length 896 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 897 /* check bcdVersion == 1.0 */ 898 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 899 dev_err(&ihid->client->dev, 900 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 901 le16_to_cpu(hdesc->bcdVersion)); 902 return -ENODEV; 903 } 904 905 /* Descriptor length should be 30 bytes as per the specification */ 906 dsize = le16_to_cpu(hdesc->wHIDDescLength); 907 if (dsize != sizeof(struct i2c_hid_desc)) { 908 dev_err(&ihid->client->dev, 909 "weird size of HID descriptor (%u)\n", dsize); 910 return -ENODEV; 911 } 912 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc); 913 return 0; 914 } 915 916 static int i2c_hid_core_power_up(struct i2c_hid *ihid) 917 { 918 if (!ihid->ops->power_up) 919 return 0; 920 921 return ihid->ops->power_up(ihid->ops); 922 } 923 924 static void i2c_hid_core_power_down(struct i2c_hid *ihid) 925 { 926 if (!ihid->ops->power_down) 927 return; 928 929 ihid->ops->power_down(ihid->ops); 930 } 931 932 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid) 933 { 934 if (!ihid->ops->shutdown_tail) 935 return; 936 937 ihid->ops->shutdown_tail(ihid->ops); 938 } 939 940 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff) 941 { 942 struct i2c_client *client = ihid->client; 943 struct hid_device *hid = ihid->hid; 944 int ret; 945 946 ret = hid_driver_suspend(hid, PMSG_SUSPEND); 947 if (ret < 0) 948 return ret; 949 950 /* Save some power */ 951 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND)) 952 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 953 954 disable_irq(client->irq); 955 956 if (force_poweroff || !device_may_wakeup(&client->dev)) 957 i2c_hid_core_power_down(ihid); 958 959 return 0; 960 } 961 962 static int i2c_hid_core_resume(struct i2c_hid *ihid) 963 { 964 struct i2c_client *client = ihid->client; 965 struct hid_device *hid = ihid->hid; 966 int ret; 967 968 if (!device_may_wakeup(&client->dev)) 969 i2c_hid_core_power_up(ihid); 970 971 enable_irq(client->irq); 972 973 /* Instead of resetting device, simply powers the device on. This 974 * solves "incomplete reports" on Raydium devices 2386:3118 and 975 * 2386:4B33 and fixes various SIS touchscreens no longer sending 976 * data after a suspend/resume. 977 * 978 * However some ALPS touchpads generate IRQ storm without reset, so 979 * let's still reset them here. 980 */ 981 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) 982 ret = i2c_hid_hwreset(ihid); 983 else 984 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 985 986 if (ret) 987 return ret; 988 989 return hid_driver_reset_resume(hid); 990 } 991 992 /* 993 * Check that the device exists and parse the HID descriptor. 994 */ 995 static int __i2c_hid_core_probe(struct i2c_hid *ihid) 996 { 997 struct i2c_client *client = ihid->client; 998 struct hid_device *hid = ihid->hid; 999 int ret; 1000 1001 /* Make sure there is something at this address */ 1002 ret = i2c_smbus_read_byte(client); 1003 if (ret < 0) { 1004 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret); 1005 return -ENXIO; 1006 } 1007 1008 ret = i2c_hid_fetch_hid_descriptor(ihid); 1009 if (ret < 0) { 1010 dev_err(&client->dev, 1011 "Failed to fetch the HID Descriptor\n"); 1012 return ret; 1013 } 1014 1015 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1016 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1017 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1018 1019 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor, 1020 hid->product); 1021 1022 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", 1023 client->name, (u16)hid->vendor, (u16)hid->product); 1024 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1025 1026 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1027 1028 return 0; 1029 } 1030 1031 static int i2c_hid_core_register_hid(struct i2c_hid *ihid) 1032 { 1033 struct i2c_client *client = ihid->client; 1034 struct hid_device *hid = ihid->hid; 1035 int ret; 1036 1037 enable_irq(client->irq); 1038 1039 ret = hid_add_device(hid); 1040 if (ret) { 1041 if (ret != -ENODEV) 1042 hid_err(client, "can't add hid device: %d\n", ret); 1043 disable_irq(client->irq); 1044 return ret; 1045 } 1046 1047 return 0; 1048 } 1049 1050 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid) 1051 { 1052 int ret; 1053 1054 ret = i2c_hid_core_power_up(ihid); 1055 if (ret) 1056 return ret; 1057 1058 ret = __i2c_hid_core_probe(ihid); 1059 if (ret) 1060 goto err_power_down; 1061 1062 ret = i2c_hid_core_register_hid(ihid); 1063 if (ret) 1064 goto err_power_down; 1065 1066 return 0; 1067 1068 err_power_down: 1069 i2c_hid_core_power_down(ihid); 1070 1071 return ret; 1072 } 1073 1074 static void ihid_core_panel_prepare_work(struct work_struct *work) 1075 { 1076 struct i2c_hid *ihid = container_of(work, struct i2c_hid, 1077 panel_follower_prepare_work); 1078 struct hid_device *hid = ihid->hid; 1079 int ret; 1080 1081 /* 1082 * hid->version is set on the first power up. If it's still zero then 1083 * this is the first power on so we should perform initial power up 1084 * steps. 1085 */ 1086 if (!hid->version) 1087 ret = i2c_hid_core_probe_panel_follower(ihid); 1088 else 1089 ret = i2c_hid_core_resume(ihid); 1090 1091 if (ret) 1092 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret); 1093 else 1094 WRITE_ONCE(ihid->prepare_work_finished, true); 1095 1096 /* 1097 * The work APIs provide a number of memory ordering guarantees 1098 * including one that says that memory writes before schedule_work() 1099 * are always visible to the work function, but they don't appear to 1100 * guarantee that a write that happened in the work is visible after 1101 * cancel_work_sync(). We'll add a write memory barrier here to match 1102 * with i2c_hid_core_panel_unpreparing() to ensure that our write to 1103 * prepare_work_finished is visible there. 1104 */ 1105 smp_wmb(); 1106 } 1107 1108 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower) 1109 { 1110 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); 1111 1112 /* 1113 * Powering on a touchscreen can be a slow process. Queue the work to 1114 * the system workqueue so we don't block the panel's power up. 1115 */ 1116 WRITE_ONCE(ihid->prepare_work_finished, false); 1117 schedule_work(&ihid->panel_follower_prepare_work); 1118 1119 return 0; 1120 } 1121 1122 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower) 1123 { 1124 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); 1125 1126 cancel_work_sync(&ihid->panel_follower_prepare_work); 1127 1128 /* Match with ihid_core_panel_prepare_work() */ 1129 smp_rmb(); 1130 if (!READ_ONCE(ihid->prepare_work_finished)) 1131 return 0; 1132 1133 return i2c_hid_core_suspend(ihid, true); 1134 } 1135 1136 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = { 1137 .panel_prepared = i2c_hid_core_panel_prepared, 1138 .panel_unpreparing = i2c_hid_core_panel_unpreparing, 1139 }; 1140 1141 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid) 1142 { 1143 struct device *dev = &ihid->client->dev; 1144 int ret; 1145 1146 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs; 1147 1148 /* 1149 * If we're not in control of our own power up/power down then we can't 1150 * do the logic to manage wakeups. Give a warning if a user thought 1151 * that was possible then force the capability off. 1152 */ 1153 if (device_can_wakeup(dev)) { 1154 dev_warn(dev, "Can't wakeup if following panel\n"); 1155 device_set_wakeup_capable(dev, false); 1156 } 1157 1158 ret = drm_panel_add_follower(dev, &ihid->panel_follower); 1159 if (ret) 1160 return ret; 1161 1162 return 0; 1163 } 1164 1165 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, 1166 u16 hid_descriptor_address, u32 quirks) 1167 { 1168 int ret; 1169 struct i2c_hid *ihid; 1170 struct hid_device *hid; 1171 1172 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 1173 1174 if (!client->irq) { 1175 dev_err(&client->dev, 1176 "HID over i2c has not been provided an Int IRQ\n"); 1177 return -EINVAL; 1178 } 1179 1180 if (client->irq < 0) { 1181 if (client->irq != -EPROBE_DEFER) 1182 dev_err(&client->dev, 1183 "HID over i2c doesn't have a valid IRQ\n"); 1184 return client->irq; 1185 } 1186 1187 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1188 if (!ihid) 1189 return -ENOMEM; 1190 1191 i2c_set_clientdata(client, ihid); 1192 1193 ihid->ops = ops; 1194 ihid->client = client; 1195 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address); 1196 ihid->is_panel_follower = drm_is_panel_follower(&client->dev); 1197 1198 init_waitqueue_head(&ihid->wait); 1199 mutex_init(&ihid->reset_lock); 1200 INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work); 1201 1202 /* we need to allocate the command buffer without knowing the maximum 1203 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1204 * real computation later. */ 1205 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1206 if (ret < 0) 1207 return ret; 1208 device_enable_async_suspend(&client->dev); 1209 1210 hid = hid_allocate_device(); 1211 if (IS_ERR(hid)) { 1212 ret = PTR_ERR(hid); 1213 goto err_free_buffers; 1214 } 1215 1216 ihid->hid = hid; 1217 1218 hid->driver_data = client; 1219 hid->ll_driver = &i2c_hid_ll_driver; 1220 hid->dev.parent = &client->dev; 1221 hid->bus = BUS_I2C; 1222 hid->initial_quirks = quirks; 1223 1224 /* Power on and probe unless device is a panel follower. */ 1225 if (!ihid->is_panel_follower) { 1226 ret = i2c_hid_core_power_up(ihid); 1227 if (ret < 0) 1228 goto err_destroy_device; 1229 1230 ret = __i2c_hid_core_probe(ihid); 1231 if (ret < 0) 1232 goto err_power_down; 1233 } 1234 1235 ret = i2c_hid_init_irq(client); 1236 if (ret < 0) 1237 goto err_power_down; 1238 1239 /* 1240 * If we're a panel follower, we'll register when the panel turns on; 1241 * otherwise we do it right away. 1242 */ 1243 if (ihid->is_panel_follower) 1244 ret = i2c_hid_core_register_panel_follower(ihid); 1245 else 1246 ret = i2c_hid_core_register_hid(ihid); 1247 if (ret) 1248 goto err_free_irq; 1249 1250 return 0; 1251 1252 err_free_irq: 1253 free_irq(client->irq, ihid); 1254 err_power_down: 1255 if (!ihid->is_panel_follower) 1256 i2c_hid_core_power_down(ihid); 1257 err_destroy_device: 1258 hid_destroy_device(hid); 1259 err_free_buffers: 1260 i2c_hid_free_buffers(ihid); 1261 1262 return ret; 1263 } 1264 EXPORT_SYMBOL_GPL(i2c_hid_core_probe); 1265 1266 void i2c_hid_core_remove(struct i2c_client *client) 1267 { 1268 struct i2c_hid *ihid = i2c_get_clientdata(client); 1269 struct hid_device *hid; 1270 1271 /* 1272 * If we're a follower, the act of unfollowing will cause us to be 1273 * powered down. Otherwise we need to manually do it. 1274 */ 1275 if (ihid->is_panel_follower) 1276 drm_panel_remove_follower(&ihid->panel_follower); 1277 else 1278 i2c_hid_core_suspend(ihid, true); 1279 1280 hid = ihid->hid; 1281 hid_destroy_device(hid); 1282 1283 free_irq(client->irq, ihid); 1284 1285 if (ihid->bufsize) 1286 i2c_hid_free_buffers(ihid); 1287 } 1288 EXPORT_SYMBOL_GPL(i2c_hid_core_remove); 1289 1290 void i2c_hid_core_shutdown(struct i2c_client *client) 1291 { 1292 struct i2c_hid *ihid = i2c_get_clientdata(client); 1293 1294 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 1295 free_irq(client->irq, ihid); 1296 1297 i2c_hid_core_shutdown_tail(ihid); 1298 } 1299 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown); 1300 1301 static int i2c_hid_core_pm_suspend(struct device *dev) 1302 { 1303 struct i2c_client *client = to_i2c_client(dev); 1304 struct i2c_hid *ihid = i2c_get_clientdata(client); 1305 1306 if (ihid->is_panel_follower) 1307 return 0; 1308 1309 return i2c_hid_core_suspend(ihid, false); 1310 } 1311 1312 static int i2c_hid_core_pm_resume(struct device *dev) 1313 { 1314 struct i2c_client *client = to_i2c_client(dev); 1315 struct i2c_hid *ihid = i2c_get_clientdata(client); 1316 1317 if (ihid->is_panel_follower) 1318 return 0; 1319 1320 return i2c_hid_core_resume(ihid); 1321 } 1322 1323 const struct dev_pm_ops i2c_hid_core_pm = { 1324 SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume) 1325 }; 1326 EXPORT_SYMBOL_GPL(i2c_hid_core_pm); 1327 1328 MODULE_DESCRIPTION("HID over I2C core driver"); 1329 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1330 MODULE_LICENSE("GPL"); 1331