1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * HID Driver for ELAN Touchpad 4 * 5 * Currently only supports touchpad found on HP Pavilion X2 10 6 * 7 * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai> 8 */ 9 10 #include <linux/hid.h> 11 #include <linux/input/mt.h> 12 #include <linux/leds.h> 13 #include <linux/module.h> 14 #include <linux/usb.h> 15 16 #include "hid-ids.h" 17 18 #define ELAN_MT_I2C 0x5d 19 #define ELAN_SINGLE_FINGER 0x81 20 #define ELAN_MT_FIRST_FINGER 0x82 21 #define ELAN_MT_SECOND_FINGER 0x83 22 #define ELAN_INPUT_REPORT_SIZE 8 23 #define ELAN_I2C_REPORT_SIZE 32 24 #define ELAN_FINGER_DATA_LEN 5 25 #define ELAN_MAX_FINGERS 5 26 #define ELAN_MAX_PRESSURE 255 27 #define ELAN_TP_USB_INTF 1 28 29 #define ELAN_FEATURE_REPORT 0x0d 30 #define ELAN_FEATURE_SIZE 5 31 #define ELAN_PARAM_MAX_X 6 32 #define ELAN_PARAM_MAX_Y 7 33 #define ELAN_PARAM_RES 8 34 35 #define ELAN_MUTE_LED_REPORT 0xBC 36 #define ELAN_LED_REPORT_SIZE 8 37 38 #define ELAN_HAS_LED BIT(0) 39 40 struct elan_drvdata { 41 struct input_dev *input; 42 u8 prev_report[ELAN_INPUT_REPORT_SIZE]; 43 struct led_classdev mute_led; 44 u8 mute_led_state; 45 u16 max_x; 46 u16 max_y; 47 u16 res_x; 48 u16 res_y; 49 }; 50 51 static int is_not_elan_touchpad(struct hid_device *hdev) 52 { 53 if (hid_is_usb(hdev)) { 54 struct usb_interface *intf = to_usb_interface(hdev->dev.parent); 55 56 return (intf->altsetting->desc.bInterfaceNumber != 57 ELAN_TP_USB_INTF); 58 } 59 60 return 0; 61 } 62 63 static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi, 64 struct hid_field *field, struct hid_usage *usage, 65 unsigned long **bit, int *max) 66 { 67 if (is_not_elan_touchpad(hdev)) 68 return 0; 69 70 if (field->report->id == ELAN_SINGLE_FINGER || 71 field->report->id == ELAN_MT_FIRST_FINGER || 72 field->report->id == ELAN_MT_SECOND_FINGER || 73 field->report->id == ELAN_MT_I2C) 74 return -1; 75 76 return 0; 77 } 78 79 static int elan_get_device_param(struct hid_device *hdev, 80 unsigned char *dmabuf, unsigned char param) 81 { 82 int ret; 83 84 dmabuf[0] = ELAN_FEATURE_REPORT; 85 dmabuf[1] = 0x05; 86 dmabuf[2] = 0x03; 87 dmabuf[3] = param; 88 dmabuf[4] = 0x01; 89 90 ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf, 91 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT, 92 HID_REQ_SET_REPORT); 93 if (ret != ELAN_FEATURE_SIZE) { 94 hid_err(hdev, "Set report error for parm %d: %d\n", param, ret); 95 return ret; 96 } 97 98 ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf, 99 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT, 100 HID_REQ_GET_REPORT); 101 if (ret != ELAN_FEATURE_SIZE) { 102 hid_err(hdev, "Get report error for parm %d: %d\n", param, ret); 103 return ret; 104 } 105 106 return 0; 107 } 108 109 static unsigned int elan_convert_res(char val) 110 { 111 /* 112 * (value from firmware) * 10 + 790 = dpi 113 * dpi * 10 / 254 = dots/mm 114 */ 115 return (val * 10 + 790) * 10 / 254; 116 } 117 118 static int elan_get_device_params(struct hid_device *hdev) 119 { 120 struct elan_drvdata *drvdata = hid_get_drvdata(hdev); 121 unsigned char *dmabuf; 122 int ret; 123 124 dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL); 125 if (!dmabuf) 126 return -ENOMEM; 127 128 ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X); 129 if (ret) 130 goto err; 131 132 drvdata->max_x = (dmabuf[4] << 8) | dmabuf[3]; 133 134 ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y); 135 if (ret) 136 goto err; 137 138 drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3]; 139 140 ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES); 141 if (ret) 142 goto err; 143 144 drvdata->res_x = elan_convert_res(dmabuf[3]); 145 drvdata->res_y = elan_convert_res(dmabuf[4]); 146 147 err: 148 kfree(dmabuf); 149 return ret; 150 } 151 152 static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi) 153 { 154 int ret; 155 struct input_dev *input; 156 struct elan_drvdata *drvdata = hid_get_drvdata(hdev); 157 158 if (is_not_elan_touchpad(hdev)) 159 return 0; 160 161 ret = elan_get_device_params(hdev); 162 if (ret) 163 return ret; 164 165 input = devm_input_allocate_device(&hdev->dev); 166 if (!input) 167 return -ENOMEM; 168 169 input->name = "Elan Touchpad"; 170 input->phys = hdev->phys; 171 input->uniq = hdev->uniq; 172 input->id.bustype = hdev->bus; 173 input->id.vendor = hdev->vendor; 174 input->id.product = hdev->product; 175 input->id.version = hdev->version; 176 input->dev.parent = &hdev->dev; 177 178 input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x, 179 0, 0); 180 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y, 181 0, 0); 182 input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE, 183 0, 0); 184 185 __set_bit(BTN_LEFT, input->keybit); 186 __set_bit(INPUT_PROP_BUTTONPAD, input->propbit); 187 188 ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER); 189 if (ret) { 190 hid_err(hdev, "Failed to init elan MT slots: %d\n", ret); 191 return ret; 192 } 193 194 input_abs_set_res(input, ABS_X, drvdata->res_x); 195 input_abs_set_res(input, ABS_Y, drvdata->res_y); 196 197 ret = input_register_device(input); 198 if (ret) { 199 hid_err(hdev, "Failed to register elan input device: %d\n", 200 ret); 201 input_mt_destroy_slots(input); 202 return ret; 203 } 204 205 drvdata->input = input; 206 207 return 0; 208 } 209 210 static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data, 211 unsigned int slot_num) 212 { 213 struct input_dev *input = drvdata->input; 214 int x, y, p; 215 216 bool active = !!data; 217 218 input_mt_slot(input, slot_num); 219 input_mt_report_slot_state(input, MT_TOOL_FINGER, active); 220 if (active) { 221 x = ((data[0] & 0xF0) << 4) | data[1]; 222 y = drvdata->max_y - 223 (((data[0] & 0x07) << 8) | data[2]); 224 p = data[4]; 225 226 input_report_abs(input, ABS_MT_POSITION_X, x); 227 input_report_abs(input, ABS_MT_POSITION_Y, y); 228 input_report_abs(input, ABS_MT_PRESSURE, p); 229 } 230 } 231 232 static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data) 233 { 234 int i; 235 struct input_dev *input = drvdata->input; 236 237 /* 238 * There is 3 types of reports: for single touch, 239 * for multitouch - first finger and for multitouch - second finger 240 * 241 * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER: 242 * 243 * byte 1: 1 0 0 0 0 0 0 1 // 0x81 or 0x82 244 * byte 2: 0 0 0 0 0 0 0 0 // looks like unused 245 * byte 3: f5 f4 f3 f2 f1 0 0 L 246 * byte 4: x12 x11 x10 x9 0? y11 y10 y9 247 * byte 5: x8 x7 x6 x5 x4 x3 x2 x1 248 * byte 6: y8 y7 y6 y5 y4 y3 y2 y1 249 * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1 250 * byte 8: p8 p7 p6 p5 p4 p3 p2 p1 251 * 252 * packet structure for ELAN_MT_SECOND_FINGER: 253 * 254 * byte 1: 1 0 0 0 0 0 1 1 // 0x83 255 * byte 2: x12 x11 x10 x9 0 y11 y10 y9 256 * byte 3: x8 x7 x6 x5 x4 x3 x2 x1 257 * byte 4: y8 y7 y6 y5 y4 y3 y2 y1 258 * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1 259 * byte 6: p8 p7 p6 p5 p4 p3 p2 p1 260 * byte 7: 0 0 0 0 0 0 0 0 261 * byte 8: 0 0 0 0 0 0 0 0 262 * 263 * f5-f1: finger touch bits 264 * L: clickpad button 265 * sy / sx: finger width / height expressed in traces, the total number 266 * of traces can be queried by doing a HID_REQ_SET_REPORT 267 * { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the 268 * returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces. 269 * p: pressure 270 */ 271 272 if (data[0] == ELAN_SINGLE_FINGER) { 273 for (i = 0; i < ELAN_MAX_FINGERS; i++) { 274 if (data[2] & BIT(i + 3)) 275 elan_report_mt_slot(drvdata, data + 3, i); 276 else 277 elan_report_mt_slot(drvdata, NULL, i); 278 } 279 input_report_key(input, BTN_LEFT, data[2] & 0x01); 280 } 281 /* 282 * When touched with two fingers Elan touchpad will emit two HID reports 283 * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER 284 * we will save ELAN_MT_FIRST_FINGER report and wait for 285 * ELAN_MT_SECOND_FINGER to finish multitouch 286 */ 287 if (data[0] == ELAN_MT_FIRST_FINGER) { 288 memcpy(drvdata->prev_report, data, 289 sizeof(drvdata->prev_report)); 290 return; 291 } 292 293 if (data[0] == ELAN_MT_SECOND_FINGER) { 294 int first = 0; 295 u8 *prev_report = drvdata->prev_report; 296 297 if (prev_report[0] != ELAN_MT_FIRST_FINGER) 298 return; 299 300 for (i = 0; i < ELAN_MAX_FINGERS; i++) { 301 if (prev_report[2] & BIT(i + 3)) { 302 if (!first) { 303 first = 1; 304 elan_report_mt_slot(drvdata, prev_report + 3, i); 305 } else { 306 elan_report_mt_slot(drvdata, data + 1, i); 307 } 308 } else { 309 elan_report_mt_slot(drvdata, NULL, i); 310 } 311 } 312 input_report_key(input, BTN_LEFT, prev_report[2] & 0x01); 313 } 314 315 input_mt_sync_frame(input); 316 input_sync(input); 317 } 318 319 static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data) 320 { 321 struct input_dev *input = drvdata->input; 322 u8 *finger_data; 323 int i; 324 325 /* 326 * Elan MT touchpads in i2c mode send finger data in the same format 327 * as in USB mode, but then with all fingers in a single packet. 328 * 329 * packet structure for ELAN_MT_I2C: 330 * 331 * byte 1: 1 0 0 1 1 1 0 1 // 0x5d 332 * byte 2: f5 f4 f3 f2 f1 0 0 L 333 * byte 3: x12 x11 x10 x9 0? y11 y10 y9 334 * byte 4: x8 x7 x6 x5 x4 x3 x2 x1 335 * byte 5: y8 y7 y6 y5 y4 y3 y2 y1 336 * byte 6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1 337 * byte 7: p8 p7 p6 p5 p4 p3 p2 p1 338 * byte 8-12: Same as byte 3-7 for second finger down 339 * byte 13-17: Same as byte 3-7 for third finger down 340 * byte 18-22: Same as byte 3-7 for fourth finger down 341 * byte 23-27: Same as byte 3-7 for fifth finger down 342 */ 343 344 finger_data = data + 2; 345 for (i = 0; i < ELAN_MAX_FINGERS; i++) { 346 if (data[1] & BIT(i + 3)) { 347 elan_report_mt_slot(drvdata, finger_data, i); 348 finger_data += ELAN_FINGER_DATA_LEN; 349 } else { 350 elan_report_mt_slot(drvdata, NULL, i); 351 } 352 } 353 354 input_report_key(input, BTN_LEFT, data[1] & 0x01); 355 input_mt_sync_frame(input); 356 input_sync(input); 357 } 358 359 static int elan_raw_event(struct hid_device *hdev, 360 struct hid_report *report, u8 *data, int size) 361 { 362 struct elan_drvdata *drvdata = hid_get_drvdata(hdev); 363 364 if (is_not_elan_touchpad(hdev)) 365 return 0; 366 367 if (data[0] == ELAN_SINGLE_FINGER || 368 data[0] == ELAN_MT_FIRST_FINGER || 369 data[0] == ELAN_MT_SECOND_FINGER) { 370 if (size == ELAN_INPUT_REPORT_SIZE) { 371 elan_usb_report_input(drvdata, data); 372 return 1; 373 } 374 } 375 376 if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) { 377 elan_i2c_report_input(drvdata, data); 378 return 1; 379 } 380 381 return 0; 382 } 383 384 static int elan_start_multitouch(struct hid_device *hdev) 385 { 386 int ret; 387 388 /* 389 * This byte sequence will enable multitouch mode and disable 390 * mouse emulation 391 */ 392 static const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 }; 393 unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL); 394 395 if (!dmabuf) 396 return -ENOMEM; 397 398 ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf), 399 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 400 401 kfree(dmabuf); 402 403 if (ret != sizeof(buf)) { 404 hid_err(hdev, "Failed to start multitouch: %d\n", ret); 405 return ret; 406 } 407 408 return 0; 409 } 410 411 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev, 412 enum led_brightness value) 413 { 414 int ret; 415 u8 led_state; 416 struct device *dev = led_cdev->dev->parent; 417 struct hid_device *hdev = to_hid_device(dev); 418 struct elan_drvdata *drvdata = hid_get_drvdata(hdev); 419 420 unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL); 421 422 if (!dmabuf) 423 return -ENOMEM; 424 425 led_state = !!value; 426 427 dmabuf[0] = ELAN_MUTE_LED_REPORT; 428 dmabuf[1] = 0x02; 429 dmabuf[2] = led_state; 430 431 ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE, 432 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 433 434 kfree(dmabuf); 435 436 if (ret != ELAN_LED_REPORT_SIZE) { 437 if (ret != -ENODEV) 438 hid_err(hdev, "Failed to set mute led brightness: %d\n", ret); 439 return ret < 0 ? ret : -EIO; 440 } 441 442 drvdata->mute_led_state = led_state; 443 return 0; 444 } 445 446 static int elan_init_mute_led(struct hid_device *hdev) 447 { 448 struct elan_drvdata *drvdata = hid_get_drvdata(hdev); 449 struct led_classdev *mute_led = &drvdata->mute_led; 450 451 mute_led->name = "elan:red:mute"; 452 mute_led->default_trigger = "audio-mute"; 453 mute_led->brightness_set_blocking = elan_mute_led_set_brigtness; 454 mute_led->max_brightness = LED_ON; 455 mute_led->flags = LED_HW_PLUGGABLE; 456 mute_led->dev = &hdev->dev; 457 458 return devm_led_classdev_register(&hdev->dev, mute_led); 459 } 460 461 static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id) 462 { 463 int ret; 464 struct elan_drvdata *drvdata; 465 466 drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL); 467 468 if (!drvdata) 469 return -ENOMEM; 470 471 hid_set_drvdata(hdev, drvdata); 472 473 ret = hid_parse(hdev); 474 if (ret) { 475 hid_err(hdev, "Hid Parse failed\n"); 476 return ret; 477 } 478 479 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); 480 if (ret) { 481 hid_err(hdev, "Hid hw start failed\n"); 482 return ret; 483 } 484 485 if (is_not_elan_touchpad(hdev)) 486 return 0; 487 488 if (!drvdata->input) { 489 hid_err(hdev, "Input device is not registered\n"); 490 ret = -ENAVAIL; 491 goto err; 492 } 493 494 ret = elan_start_multitouch(hdev); 495 if (ret) 496 goto err; 497 498 if (id->driver_data & ELAN_HAS_LED) { 499 ret = elan_init_mute_led(hdev); 500 if (ret) 501 goto err; 502 } 503 504 return 0; 505 err: 506 hid_hw_stop(hdev); 507 return ret; 508 } 509 510 static void elan_remove(struct hid_device *hdev) 511 { 512 hid_hw_stop(hdev); 513 } 514 515 static const struct hid_device_id elan_devices[] = { 516 { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2), 517 .driver_data = ELAN_HAS_LED }, 518 { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER), 519 .driver_data = ELAN_HAS_LED }, 520 { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) }, 521 { } 522 }; 523 MODULE_DEVICE_TABLE(hid, elan_devices); 524 525 static struct hid_driver elan_driver = { 526 .name = "elan", 527 .id_table = elan_devices, 528 .input_mapping = elan_input_mapping, 529 .input_configured = elan_input_configured, 530 .raw_event = elan_raw_event, 531 .probe = elan_probe, 532 .remove = elan_remove, 533 }; 534 535 module_hid_driver(elan_driver); 536 537 MODULE_LICENSE("GPL"); 538 MODULE_AUTHOR("Alexandrov Stanislav"); 539 MODULE_DESCRIPTION("Driver for HID ELAN Touchpads"); 540