// SPDX-License-Identifier: GPL-2.0-or-later /* * HID Driver for ELAN Touchpad * * Currently only supports touchpad found on HP Pavilion X2 10 * * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai> */ #include <linux/hid.h> #include <linux/input/mt.h> #include <linux/leds.h> #include <linux/module.h> #include <linux/usb.h> #include "hid-ids.h" #define ELAN_MT_I2C 0x5d #define ELAN_SINGLE_FINGER 0x81 #define ELAN_MT_FIRST_FINGER 0x82 #define ELAN_MT_SECOND_FINGER 0x83 #define ELAN_INPUT_REPORT_SIZE 8 #define ELAN_I2C_REPORT_SIZE 32 #define ELAN_FINGER_DATA_LEN 5 #define ELAN_MAX_FINGERS 5 #define ELAN_MAX_PRESSURE 255 #define ELAN_TP_USB_INTF 1 #define ELAN_FEATURE_REPORT 0x0d #define ELAN_FEATURE_SIZE 5 #define ELAN_PARAM_MAX_X 6 #define ELAN_PARAM_MAX_Y 7 #define ELAN_PARAM_RES 8 #define ELAN_MUTE_LED_REPORT 0xBC #define ELAN_LED_REPORT_SIZE 8 #define ELAN_HAS_LED BIT(0) struct elan_drvdata { struct input_dev *input; u8 prev_report[ELAN_INPUT_REPORT_SIZE]; struct led_classdev mute_led; u8 mute_led_state; u16 max_x; u16 max_y; u16 res_x; u16 res_y; }; static int is_not_elan_touchpad(struct hid_device *hdev) { if (hid_is_usb(hdev)) { struct usb_interface *intf = to_usb_interface(hdev->dev.parent); return (intf->altsetting->desc.bInterfaceNumber != ELAN_TP_USB_INTF); } return 0; } static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi, struct hid_field *field, struct hid_usage *usage, unsigned long **bit, int *max) { if (is_not_elan_touchpad(hdev)) return 0; if (field->report->id == ELAN_SINGLE_FINGER || field->report->id == ELAN_MT_FIRST_FINGER || field->report->id == ELAN_MT_SECOND_FINGER || field->report->id == ELAN_MT_I2C) return -1; return 0; } static int elan_get_device_param(struct hid_device *hdev, unsigned char *dmabuf, unsigned char param) { int ret; dmabuf[0] = ELAN_FEATURE_REPORT; dmabuf[1] = 0x05; dmabuf[2] = 0x03; dmabuf[3] = param; dmabuf[4] = 0x01; ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf, ELAN_FEATURE_SIZE, HID_FEATURE_REPORT, HID_REQ_SET_REPORT); if (ret != ELAN_FEATURE_SIZE) { hid_err(hdev, "Set report error for parm %d: %d\n", param, ret); return ret; } ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf, ELAN_FEATURE_SIZE, HID_FEATURE_REPORT, HID_REQ_GET_REPORT); if (ret != ELAN_FEATURE_SIZE) { hid_err(hdev, "Get report error for parm %d: %d\n", param, ret); return ret; } return 0; } static unsigned int elan_convert_res(char val) { /* * (value from firmware) * 10 + 790 = dpi * dpi * 10 / 254 = dots/mm */ return (val * 10 + 790) * 10 / 254; } static int elan_get_device_params(struct hid_device *hdev) { struct elan_drvdata *drvdata = hid_get_drvdata(hdev); unsigned char *dmabuf; int ret; dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL); if (!dmabuf) return -ENOMEM; ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X); if (ret) goto err; drvdata->max_x = (dmabuf[4] << 8) | dmabuf[3]; ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y); if (ret) goto err; drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3]; ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES); if (ret) goto err; drvdata->res_x = elan_convert_res(dmabuf[3]); drvdata->res_y = elan_convert_res(dmabuf[4]); err: kfree(dmabuf); return ret; } static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi) { int ret; struct input_dev *input; struct elan_drvdata *drvdata = hid_get_drvdata(hdev); if (is_not_elan_touchpad(hdev)) return 0; ret = elan_get_device_params(hdev); if (ret) return ret; input = devm_input_allocate_device(&hdev->dev); if (!input) return -ENOMEM; input->name = "Elan Touchpad"; input->phys = hdev->phys; input->uniq = hdev->uniq; input->id.bustype = hdev->bus; input->id.vendor = hdev->vendor; input->id.product = hdev->product; input->id.version = hdev->version; input->dev.parent = &hdev->dev; input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x, 0, 0); input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y, 0, 0); input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE, 0, 0); __set_bit(BTN_LEFT, input->keybit); __set_bit(INPUT_PROP_BUTTONPAD, input->propbit); ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER); if (ret) { hid_err(hdev, "Failed to init elan MT slots: %d\n", ret); return ret; } input_abs_set_res(input, ABS_X, drvdata->res_x); input_abs_set_res(input, ABS_Y, drvdata->res_y); ret = input_register_device(input); if (ret) { hid_err(hdev, "Failed to register elan input device: %d\n", ret); input_mt_destroy_slots(input); return ret; } drvdata->input = input; return 0; } static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data, unsigned int slot_num) { struct input_dev *input = drvdata->input; int x, y, p; bool active = !!data; input_mt_slot(input, slot_num); input_mt_report_slot_state(input, MT_TOOL_FINGER, active); if (active) { x = ((data[0] & 0xF0) << 4) | data[1]; y = drvdata->max_y - (((data[0] & 0x07) << 8) | data[2]); p = data[4]; input_report_abs(input, ABS_MT_POSITION_X, x); input_report_abs(input, ABS_MT_POSITION_Y, y); input_report_abs(input, ABS_MT_PRESSURE, p); } } static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data) { int i; struct input_dev *input = drvdata->input; /* * There is 3 types of reports: for single touch, * for multitouch - first finger and for multitouch - second finger * * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER: * * byte 1: 1 0 0 0 0 0 0 1 // 0x81 or 0x82 * byte 2: 0 0 0 0 0 0 0 0 // looks like unused * byte 3: f5 f4 f3 f2 f1 0 0 L * byte 4: x12 x11 x10 x9 0? y11 y10 y9 * byte 5: x8 x7 x6 x5 x4 x3 x2 x1 * byte 6: y8 y7 y6 y5 y4 y3 y2 y1 * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1 * byte 8: p8 p7 p6 p5 p4 p3 p2 p1 * * packet structure for ELAN_MT_SECOND_FINGER: * * byte 1: 1 0 0 0 0 0 1 1 // 0x83 * byte 2: x12 x11 x10 x9 0 y11 y10 y9 * byte 3: x8 x7 x6 x5 x4 x3 x2 x1 * byte 4: y8 y7 y6 y5 y4 y3 y2 y1 * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1 * byte 6: p8 p7 p6 p5 p4 p3 p2 p1 * byte 7: 0 0 0 0 0 0 0 0 * byte 8: 0 0 0 0 0 0 0 0 * * f5-f1: finger touch bits * L: clickpad button * sy / sx: finger width / height expressed in traces, the total number * of traces can be queried by doing a HID_REQ_SET_REPORT * { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the * returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces. * p: pressure */ if (data[0] == ELAN_SINGLE_FINGER) { for (i = 0; i < ELAN_MAX_FINGERS; i++) { if (data[2] & BIT(i + 3)) elan_report_mt_slot(drvdata, data + 3, i); else elan_report_mt_slot(drvdata, NULL, i); } input_report_key(input, BTN_LEFT, data[2] & 0x01); } /* * When touched with two fingers Elan touchpad will emit two HID reports * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER * we will save ELAN_MT_FIRST_FINGER report and wait for * ELAN_MT_SECOND_FINGER to finish multitouch */ if (data[0] == ELAN_MT_FIRST_FINGER) { memcpy(drvdata->prev_report, data, sizeof(drvdata->prev_report)); return; } if (data[0] == ELAN_MT_SECOND_FINGER) { int first = 0; u8 *prev_report = drvdata->prev_report; if (prev_report[0] != ELAN_MT_FIRST_FINGER) return; for (i = 0; i < ELAN_MAX_FINGERS; i++) { if (prev_report[2] & BIT(i + 3)) { if (!first) { first = 1; elan_report_mt_slot(drvdata, prev_report + 3, i); } else { elan_report_mt_slot(drvdata, data + 1, i); } } else { elan_report_mt_slot(drvdata, NULL, i); } } input_report_key(input, BTN_LEFT, prev_report[2] & 0x01); } input_mt_sync_frame(input); input_sync(input); } static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data) { struct input_dev *input = drvdata->input; u8 *finger_data; int i; /* * Elan MT touchpads in i2c mode send finger data in the same format * as in USB mode, but then with all fingers in a single packet. * * packet structure for ELAN_MT_I2C: * * byte 1: 1 0 0 1 1 1 0 1 // 0x5d * byte 2: f5 f4 f3 f2 f1 0 0 L * byte 3: x12 x11 x10 x9 0? y11 y10 y9 * byte 4: x8 x7 x6 x5 x4 x3 x2 x1 * byte 5: y8 y7 y6 y5 y4 y3 y2 y1 * byte 6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1 * byte 7: p8 p7 p6 p5 p4 p3 p2 p1 * byte 8-12: Same as byte 3-7 for second finger down * byte 13-17: Same as byte 3-7 for third finger down * byte 18-22: Same as byte 3-7 for fourth finger down * byte 23-27: Same as byte 3-7 for fifth finger down */ finger_data = data + 2; for (i = 0; i < ELAN_MAX_FINGERS; i++) { if (data[1] & BIT(i + 3)) { elan_report_mt_slot(drvdata, finger_data, i); finger_data += ELAN_FINGER_DATA_LEN; } else { elan_report_mt_slot(drvdata, NULL, i); } } input_report_key(input, BTN_LEFT, data[1] & 0x01); input_mt_sync_frame(input); input_sync(input); } static int elan_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size) { struct elan_drvdata *drvdata = hid_get_drvdata(hdev); if (is_not_elan_touchpad(hdev)) return 0; if (data[0] == ELAN_SINGLE_FINGER || data[0] == ELAN_MT_FIRST_FINGER || data[0] == ELAN_MT_SECOND_FINGER) { if (size == ELAN_INPUT_REPORT_SIZE) { elan_usb_report_input(drvdata, data); return 1; } } if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) { elan_i2c_report_input(drvdata, data); return 1; } return 0; } static int elan_start_multitouch(struct hid_device *hdev) { int ret; /* * This byte sequence will enable multitouch mode and disable * mouse emulation */ static const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 }; unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL); if (!dmabuf) return -ENOMEM; ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_SET_REPORT); kfree(dmabuf); if (ret != sizeof(buf)) { hid_err(hdev, "Failed to start multitouch: %d\n", ret); return ret; } return 0; } static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev, enum led_brightness value) { int ret; u8 led_state; struct device *dev = led_cdev->dev->parent; struct hid_device *hdev = to_hid_device(dev); struct elan_drvdata *drvdata = hid_get_drvdata(hdev); unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL); if (!dmabuf) return -ENOMEM; led_state = !!value; dmabuf[0] = ELAN_MUTE_LED_REPORT; dmabuf[1] = 0x02; dmabuf[2] = led_state; ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE, HID_FEATURE_REPORT, HID_REQ_SET_REPORT); kfree(dmabuf); if (ret != ELAN_LED_REPORT_SIZE) { if (ret != -ENODEV) hid_err(hdev, "Failed to set mute led brightness: %d\n", ret); return ret < 0 ? ret : -EIO; } drvdata->mute_led_state = led_state; return 0; } static int elan_init_mute_led(struct hid_device *hdev) { struct elan_drvdata *drvdata = hid_get_drvdata(hdev); struct led_classdev *mute_led = &drvdata->mute_led; mute_led->name = "elan:red:mute"; mute_led->default_trigger = "audio-mute"; mute_led->brightness_set_blocking = elan_mute_led_set_brigtness; mute_led->max_brightness = LED_ON; mute_led->flags = LED_HW_PLUGGABLE; mute_led->dev = &hdev->dev; return devm_led_classdev_register(&hdev->dev, mute_led); } static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id) { int ret; struct elan_drvdata *drvdata; drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL); if (!drvdata) return -ENOMEM; hid_set_drvdata(hdev, drvdata); ret = hid_parse(hdev); if (ret) { hid_err(hdev, "Hid Parse failed\n"); return ret; } ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); if (ret) { hid_err(hdev, "Hid hw start failed\n"); return ret; } if (is_not_elan_touchpad(hdev)) return 0; if (!drvdata->input) { hid_err(hdev, "Input device is not registered\n"); ret = -ENAVAIL; goto err; } ret = elan_start_multitouch(hdev); if (ret) goto err; if (id->driver_data & ELAN_HAS_LED) { ret = elan_init_mute_led(hdev); if (ret) goto err; } return 0; err: hid_hw_stop(hdev); return ret; } static const struct hid_device_id elan_devices[] = { { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2), .driver_data = ELAN_HAS_LED }, { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER), .driver_data = ELAN_HAS_LED }, { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) }, { } }; MODULE_DEVICE_TABLE(hid, elan_devices); static struct hid_driver elan_driver = { .name = "elan", .id_table = elan_devices, .input_mapping = elan_input_mapping, .input_configured = elan_input_configured, .raw_event = elan_raw_event, .probe = elan_probe, }; module_hid_driver(elan_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Alexandrov Stanislav"); MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");