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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * HID Driver for ELAN Touchpad4 *5 * Currently only supports touchpad found on HP Pavilion X2 106 *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 0x5d19#define ELAN_SINGLE_FINGER 0x8120#define ELAN_MT_FIRST_FINGER 0x8221#define ELAN_MT_SECOND_FINGER 0x8322#define ELAN_INPUT_REPORT_SIZE 823#define ELAN_I2C_REPORT_SIZE 3224#define ELAN_FINGER_DATA_LEN 525#define ELAN_MAX_FINGERS 526#define ELAN_MAX_PRESSURE 25527#define ELAN_TP_USB_INTF 128 29#define ELAN_FEATURE_REPORT 0x0d30#define ELAN_FEATURE_SIZE 531#define ELAN_PARAM_MAX_X 632#define ELAN_PARAM_MAX_Y 733#define ELAN_PARAM_RES 834 35#define ELAN_MUTE_LED_REPORT 0xBC36#define ELAN_LED_REPORT_SIZE 837 38#define ELAN_HAS_LED BIT(0)39 40struct 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 51static 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 63static 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 79static 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 109static unsigned int elan_convert_res(char val)110{111 /*112 * (value from firmware) * 10 + 790 = dpi113 * dpi * 10 / 254 = dots/mm114 */115 return (val * 10 + 790) * 10 / 254;116}117 118static 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 147err:148 kfree(dmabuf);149 return ret;150}151 152static 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 210static 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 232static 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 finger240 *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 0x82244 * byte 2: 0 0 0 0 0 0 0 0 // looks like unused245 * byte 3: f5 f4 f3 f2 f1 0 0 L246 * byte 4: x12 x11 x10 x9 0? y11 y10 y9247 * byte 5: x8 x7 x6 x5 x4 x3 x2 x1248 * byte 6: y8 y7 y6 y5 y4 y3 y2 y1249 * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1250 * byte 8: p8 p7 p6 p5 p4 p3 p2 p1251 *252 * packet structure for ELAN_MT_SECOND_FINGER:253 *254 * byte 1: 1 0 0 0 0 0 1 1 // 0x83255 * byte 2: x12 x11 x10 x9 0 y11 y10 y9256 * byte 3: x8 x7 x6 x5 x4 x3 x2 x1257 * byte 4: y8 y7 y6 y5 y4 y3 y2 y1258 * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1259 * byte 6: p8 p7 p6 p5 p4 p3 p2 p1260 * byte 7: 0 0 0 0 0 0 0 0261 * byte 8: 0 0 0 0 0 0 0 0262 *263 * f5-f1: finger touch bits264 * L: clickpad button265 * sy / sx: finger width / height expressed in traces, the total number266 * of traces can be queried by doing a HID_REQ_SET_REPORT267 * { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the268 * returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.269 * p: pressure270 */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 else277 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 reports283 * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER284 * we will save ELAN_MT_FIRST_FINGER report and wait for285 * ELAN_MT_SECOND_FINGER to finish multitouch286 */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 319static 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 format327 * 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 // 0x5d332 * byte 2: f5 f4 f3 f2 f1 0 0 L333 * byte 3: x12 x11 x10 x9 0? y11 y10 y9334 * byte 4: x8 x7 x6 x5 x4 x3 x2 x1335 * byte 5: y8 y7 y6 y5 y4 y3 y2 y1336 * byte 6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1337 * byte 7: p8 p7 p6 p5 p4 p3 p2 p1338 * byte 8-12: Same as byte 3-7 for second finger down339 * byte 13-17: Same as byte 3-7 for third finger down340 * byte 18-22: Same as byte 3-7 for fourth finger down341 * byte 23-27: Same as byte 3-7 for fifth finger down342 */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 359static 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 384static int elan_start_multitouch(struct hid_device *hdev)385{386 int ret;387 388 /*389 * This byte sequence will enable multitouch mode and disable390 * mouse emulation391 */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 411static 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 446static 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 461static 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;505err:506 hid_hw_stop(hdev);507 return ret;508}509 510static const struct hid_device_id elan_devices[] = {511 { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),512 .driver_data = ELAN_HAS_LED },513 { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),514 .driver_data = ELAN_HAS_LED },515 { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },516 { }517};518MODULE_DEVICE_TABLE(hid, elan_devices);519 520static struct hid_driver elan_driver = {521 .name = "elan",522 .id_table = elan_devices,523 .input_mapping = elan_input_mapping,524 .input_configured = elan_input_configured,525 .raw_event = elan_raw_event,526 .probe = elan_probe,527};528 529module_hid_driver(elan_driver);530 531MODULE_LICENSE("GPL");532MODULE_AUTHOR("Alexandrov Stanislav");533MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");534