drivers/hid/hid-elan.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * HID Driver for ELAN Touchpad
0004  *
0005  * Currently only supports touchpad found on HP Pavilion X2 10
0006  *
0007  * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
0008  */
0009
0010 #include <linux/hid.h>
0011 #include <linux/input/mt.h>
0012 #include <linux/leds.h>
0013 #include <linux/module.h>
0014 #include <linux/usb.h>
0015
0016 #include "hid-ids.h"
0017
0018 #define ELAN_MT_I2C     0x5d
0019 #define ELAN_SINGLE_FINGER  0x81
0020 #define ELAN_MT_FIRST_FINGER    0x82
0021 #define ELAN_MT_SECOND_FINGER   0x83
0022 #define ELAN_INPUT_REPORT_SIZE  8
0023 #define ELAN_I2C_REPORT_SIZE    32
0024 #define ELAN_FINGER_DATA_LEN    5
0025 #define ELAN_MAX_FINGERS    5
0026 #define ELAN_MAX_PRESSURE   255
0027 #define ELAN_TP_USB_INTF    1
0028
0029 #define ELAN_FEATURE_REPORT 0x0d
0030 #define ELAN_FEATURE_SIZE   5
0031 #define ELAN_PARAM_MAX_X    6
0032 #define ELAN_PARAM_MAX_Y    7
0033 #define ELAN_PARAM_RES      8
0034
0035 #define ELAN_MUTE_LED_REPORT    0xBC
0036 #define ELAN_LED_REPORT_SIZE    8
0037
0038 #define ELAN_HAS_LED        BIT(0)
0039
0040 struct elan_drvdata {
0041     struct input_dev *input;
0042     u8 prev_report[ELAN_INPUT_REPORT_SIZE];
0043     struct led_classdev mute_led;
0044     u8 mute_led_state;
0045     u16 max_x;
0046     u16 max_y;
0047     u16 res_x;
0048     u16 res_y;
0049 };
0050
0051 static int is_not_elan_touchpad(struct hid_device *hdev)
0052 {
0053     if (hid_is_usb(hdev)) {
0054         struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
0055
0056         return (intf->altsetting->desc.bInterfaceNumber !=
0057             ELAN_TP_USB_INTF);
0058     }
0059
0060     return 0;
0061 }
0062
0063 static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
0064                   struct hid_field *field, struct hid_usage *usage,
0065                   unsigned long **bit, int *max)
0066 {
0067     if (is_not_elan_touchpad(hdev))
0068         return 0;
0069
0070     if (field->report->id == ELAN_SINGLE_FINGER ||
0071         field->report->id == ELAN_MT_FIRST_FINGER ||
0072         field->report->id == ELAN_MT_SECOND_FINGER ||
0073         field->report->id == ELAN_MT_I2C)
0074         return -1;
0075
0076     return 0;
0077 }
0078
0079 static int elan_get_device_param(struct hid_device *hdev,
0080                  unsigned char *dmabuf, unsigned char param)
0081 {
0082     int ret;
0083
0084     dmabuf[0] = ELAN_FEATURE_REPORT;
0085     dmabuf[1] = 0x05;
0086     dmabuf[2] = 0x03;
0087     dmabuf[3] = param;
0088     dmabuf[4] = 0x01;
0089
0090     ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
0091                  ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
0092                  HID_REQ_SET_REPORT);
0093     if (ret != ELAN_FEATURE_SIZE) {
0094         hid_err(hdev, "Set report error for parm %d: %d\n", param, ret);
0095         return ret;
0096     }
0097
0098     ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
0099                  ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
0100                  HID_REQ_GET_REPORT);
0101     if (ret != ELAN_FEATURE_SIZE) {
0102         hid_err(hdev, "Get report error for parm %d: %d\n", param, ret);
0103         return ret;
0104     }
0105
0106     return 0;
0107 }
0108
0109 static unsigned int elan_convert_res(char val)
0110 {
0111     /*
0112      * (value from firmware) * 10 + 790 = dpi
0113      * dpi * 10 / 254 = dots/mm
0114      */
0115     return (val * 10 + 790) * 10 / 254;
0116 }
0117
0118 static int elan_get_device_params(struct hid_device *hdev)
0119 {
0120     struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
0121     unsigned char *dmabuf;
0122     int ret;
0123
0124     dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL);
0125     if (!dmabuf)
0126         return -ENOMEM;
0127
0128     ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X);
0129     if (ret)
0130         goto err;
0131
0132     drvdata->max_x = (dmabuf[4] << 8) | dmabuf[3];
0133
0134     ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y);
0135     if (ret)
0136         goto err;
0137
0138     drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3];
0139
0140     ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES);
0141     if (ret)
0142         goto err;
0143
0144     drvdata->res_x = elan_convert_res(dmabuf[3]);
0145     drvdata->res_y = elan_convert_res(dmabuf[4]);
0146
0147 err:
0148     kfree(dmabuf);
0149     return ret;
0150 }
0151
0152 static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
0153 {
0154     int ret;
0155     struct input_dev *input;
0156     struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
0157
0158     if (is_not_elan_touchpad(hdev))
0159         return 0;
0160
0161     ret = elan_get_device_params(hdev);
0162     if (ret)
0163         return ret;
0164
0165     input = devm_input_allocate_device(&hdev->dev);
0166     if (!input)
0167         return -ENOMEM;
0168
0169     input->name = "Elan Touchpad";
0170     input->phys = hdev->phys;
0171     input->uniq = hdev->uniq;
0172     input->id.bustype = hdev->bus;
0173     input->id.vendor  = hdev->vendor;
0174     input->id.product = hdev->product;
0175     input->id.version = hdev->version;
0176     input->dev.parent = &hdev->dev;
0177
0178     input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x,
0179                  0, 0);
0180     input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y,
0181                  0, 0);
0182     input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE,
0183                  0, 0);
0184
0185     __set_bit(BTN_LEFT, input->keybit);
0186     __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
0187
0188     ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER);
0189     if (ret) {
0190         hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
0191         return ret;
0192     }
0193
0194     input_abs_set_res(input, ABS_X, drvdata->res_x);
0195     input_abs_set_res(input, ABS_Y, drvdata->res_y);
0196
0197     ret = input_register_device(input);
0198     if (ret) {
0199         hid_err(hdev, "Failed to register elan input device: %d\n",
0200             ret);
0201         input_mt_destroy_slots(input);
0202         return ret;
0203     }
0204
0205     drvdata->input = input;
0206
0207     return 0;
0208 }
0209
0210 static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data,
0211                 unsigned int slot_num)
0212 {
0213     struct input_dev *input = drvdata->input;
0214     int x, y, p;
0215
0216     bool active = !!data;
0217
0218     input_mt_slot(input, slot_num);
0219     input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
0220     if (active) {
0221         x = ((data[0] & 0xF0) << 4) | data[1];
0222         y = drvdata->max_y -
0223             (((data[0] & 0x07) << 8) | data[2]);
0224         p = data[4];
0225
0226         input_report_abs(input, ABS_MT_POSITION_X, x);
0227         input_report_abs(input, ABS_MT_POSITION_Y, y);
0228         input_report_abs(input, ABS_MT_PRESSURE, p);
0229     }
0230 }
0231
0232 static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data)
0233 {
0234     int i;
0235     struct input_dev *input = drvdata->input;
0236
0237     /*
0238      * There is 3 types of reports: for single touch,
0239      * for multitouch - first finger and for multitouch - second finger
0240      *
0241      * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
0242      *
0243      * byte 1: 1   0   0   0   0   0   0   1  // 0x81 or 0x82
0244      * byte 2: 0   0   0   0   0   0   0   0  // looks like unused
0245      * byte 3: f5  f4  f3  f2  f1  0   0   L
0246      * byte 4: x12 x11 x10 x9  0?  y11 y10 y9
0247      * byte 5: x8  x7  x6  x5  x4  x3  x2  x1
0248      * byte 6: y8  y7  y6  y5  y4  y3  y2  y1
0249      * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
0250      * byte 8: p8  p7  p6  p5  p4  p3  p2  p1
0251      *
0252      * packet structure for ELAN_MT_SECOND_FINGER:
0253      *
0254      * byte 1: 1   0   0   0   0   0   1   1  // 0x83
0255      * byte 2: x12 x11 x10 x9  0   y11 y10 y9
0256      * byte 3: x8  x7  x6  x5  x4  x3  x2  x1
0257      * byte 4: y8  y7  y6  y5  y4  y3  y2  y1
0258      * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
0259      * byte 6: p8  p7  p6  p5  p4  p3  p2  p1
0260      * byte 7: 0   0   0   0   0   0   0   0
0261      * byte 8: 0   0   0   0   0   0   0   0
0262      *
0263      * f5-f1: finger touch bits
0264      * L: clickpad button
0265      * sy / sx: finger width / height expressed in traces, the total number
0266      *          of traces can be queried by doing a HID_REQ_SET_REPORT
0267      *          { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the
0268      *          returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.
0269      * p: pressure
0270      */
0271
0272     if (data[0] == ELAN_SINGLE_FINGER) {
0273         for (i = 0; i < ELAN_MAX_FINGERS; i++) {
0274             if (data[2] & BIT(i + 3))
0275                 elan_report_mt_slot(drvdata, data + 3, i);
0276             else
0277                 elan_report_mt_slot(drvdata, NULL, i);
0278         }
0279         input_report_key(input, BTN_LEFT, data[2] & 0x01);
0280     }
0281     /*
0282      * When touched with two fingers Elan touchpad will emit two HID reports
0283      * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
0284      * we will save ELAN_MT_FIRST_FINGER report and wait for
0285      * ELAN_MT_SECOND_FINGER to finish multitouch
0286      */
0287     if (data[0] == ELAN_MT_FIRST_FINGER) {
0288         memcpy(drvdata->prev_report, data,
0289                sizeof(drvdata->prev_report));
0290         return;
0291     }
0292
0293     if (data[0] == ELAN_MT_SECOND_FINGER) {
0294         int first = 0;
0295         u8 *prev_report = drvdata->prev_report;
0296
0297         if (prev_report[0] != ELAN_MT_FIRST_FINGER)
0298             return;
0299
0300         for (i = 0; i < ELAN_MAX_FINGERS; i++) {
0301             if (prev_report[2] & BIT(i + 3)) {
0302                 if (!first) {
0303                     first = 1;
0304                     elan_report_mt_slot(drvdata, prev_report + 3, i);
0305                 } else {
0306                     elan_report_mt_slot(drvdata, data + 1, i);
0307                 }
0308             } else {
0309                 elan_report_mt_slot(drvdata, NULL, i);
0310             }
0311         }
0312         input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
0313     }
0314
0315     input_mt_sync_frame(input);
0316     input_sync(input);
0317 }
0318
0319 static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data)
0320 {
0321     struct input_dev *input = drvdata->input;
0322     u8 *finger_data;
0323     int i;
0324
0325     /*
0326      * Elan MT touchpads in i2c mode send finger data in the same format
0327      * as in USB mode, but then with all fingers in a single packet.
0328      *
0329      * packet structure for ELAN_MT_I2C:
0330      *
0331      * byte     1: 1   0   0   1   1   1   0   1   // 0x5d
0332      * byte     2: f5  f4  f3  f2  f1  0   0   L
0333      * byte     3: x12 x11 x10 x9  0?  y11 y10 y9
0334      * byte     4: x8  x7  x6  x5  x4  x3  x2  x1
0335      * byte     5: y8  y7  y6  y5  y4  y3  y2  y1
0336      * byte     6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
0337      * byte     7: p8  p7  p6  p5  p4  p3  p2  p1
0338      * byte  8-12: Same as byte 3-7 for second finger down
0339      * byte 13-17: Same as byte 3-7 for third finger down
0340      * byte 18-22: Same as byte 3-7 for fourth finger down
0341      * byte 23-27: Same as byte 3-7 for fifth finger down
0342      */
0343
0344     finger_data = data + 2;
0345     for (i = 0; i < ELAN_MAX_FINGERS; i++) {
0346         if (data[1] & BIT(i + 3)) {
0347             elan_report_mt_slot(drvdata, finger_data, i);
0348             finger_data += ELAN_FINGER_DATA_LEN;
0349         } else {
0350             elan_report_mt_slot(drvdata, NULL, i);
0351         }
0352     }
0353
0354     input_report_key(input, BTN_LEFT, data[1] & 0x01);
0355     input_mt_sync_frame(input);
0356     input_sync(input);
0357 }
0358
0359 static int elan_raw_event(struct hid_device *hdev,
0360               struct hid_report *report, u8 *data, int size)
0361 {
0362     struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
0363
0364     if (is_not_elan_touchpad(hdev))
0365         return 0;
0366
0367     if (data[0] == ELAN_SINGLE_FINGER ||
0368         data[0] == ELAN_MT_FIRST_FINGER ||
0369         data[0] == ELAN_MT_SECOND_FINGER) {
0370         if (size == ELAN_INPUT_REPORT_SIZE) {
0371             elan_usb_report_input(drvdata, data);
0372             return 1;
0373         }
0374     }
0375
0376     if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) {
0377         elan_i2c_report_input(drvdata, data);
0378         return 1;
0379     }
0380
0381     return 0;
0382 }
0383
0384 static int elan_start_multitouch(struct hid_device *hdev)
0385 {
0386     int ret;
0387
0388     /*
0389      * This byte sequence will enable multitouch mode and disable
0390      * mouse emulation
0391      */
0392     static const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
0393     unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);
0394
0395     if (!dmabuf)
0396         return -ENOMEM;
0397
0398     ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
0399                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
0400
0401     kfree(dmabuf);
0402
0403     if (ret != sizeof(buf)) {
0404         hid_err(hdev, "Failed to start multitouch: %d\n", ret);
0405         return ret;
0406     }
0407
0408     return 0;
0409 }
0410
0411 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
0412                        enum led_brightness value)
0413 {
0414     int ret;
0415     u8 led_state;
0416     struct device *dev = led_cdev->dev->parent;
0417     struct hid_device *hdev = to_hid_device(dev);
0418     struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
0419
0420     unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);
0421
0422     if (!dmabuf)
0423         return -ENOMEM;
0424
0425     led_state = !!value;
0426
0427     dmabuf[0] = ELAN_MUTE_LED_REPORT;
0428     dmabuf[1] = 0x02;
0429     dmabuf[2] = led_state;
0430
0431     ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
0432                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
0433
0434     kfree(dmabuf);
0435
0436     if (ret != ELAN_LED_REPORT_SIZE) {
0437         if (ret != -ENODEV)
0438             hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
0439         return ret < 0 ? ret : -EIO;
0440     }
0441
0442     drvdata->mute_led_state = led_state;
0443     return 0;
0444 }
0445
0446 static int elan_init_mute_led(struct hid_device *hdev)
0447 {
0448     struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
0449     struct led_classdev *mute_led = &drvdata->mute_led;
0450
0451     mute_led->name = "elan:red:mute";
0452     mute_led->default_trigger = "audio-mute";
0453     mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
0454     mute_led->max_brightness = LED_ON;
0455     mute_led->flags = LED_HW_PLUGGABLE;
0456     mute_led->dev = &hdev->dev;
0457
0458     return devm_led_classdev_register(&hdev->dev, mute_led);
0459 }
0460
0461 static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id)
0462 {
0463     int ret;
0464     struct elan_drvdata *drvdata;
0465
0466     drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
0467
0468     if (!drvdata)
0469         return -ENOMEM;
0470
0471     hid_set_drvdata(hdev, drvdata);
0472
0473     ret = hid_parse(hdev);
0474     if (ret) {
0475         hid_err(hdev, "Hid Parse failed\n");
0476         return ret;
0477     }
0478
0479     ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
0480     if (ret) {
0481         hid_err(hdev, "Hid hw start failed\n");
0482         return ret;
0483     }
0484
0485     if (is_not_elan_touchpad(hdev))
0486         return 0;
0487
0488     if (!drvdata->input) {
0489         hid_err(hdev, "Input device is not registered\n");
0490         ret = -ENAVAIL;
0491         goto err;
0492     }
0493
0494     ret = elan_start_multitouch(hdev);
0495     if (ret)
0496         goto err;
0497
0498     if (id->driver_data & ELAN_HAS_LED) {
0499         ret = elan_init_mute_led(hdev);
0500         if (ret)
0501             goto err;
0502     }
0503
0504     return 0;
0505 err:
0506     hid_hw_stop(hdev);
0507     return ret;
0508 }
0509
0510 static void elan_remove(struct hid_device *hdev)
0511 {
0512     hid_hw_stop(hdev);
0513 }
0514
0515 static const struct hid_device_id elan_devices[] = {
0516     { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),
0517       .driver_data = ELAN_HAS_LED },
0518     { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
0519       .driver_data = ELAN_HAS_LED },
0520     { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
0521     { }
0522 };
0523 MODULE_DEVICE_TABLE(hid, elan_devices);
0524
0525 static struct hid_driver elan_driver = {
0526     .name = "elan",
0527     .id_table = elan_devices,
0528     .input_mapping = elan_input_mapping,
0529     .input_configured = elan_input_configured,
0530     .raw_event = elan_raw_event,
0531     .probe = elan_probe,
0532     .remove = elan_remove,
0533 };
0534
0535 module_hid_driver(elan_driver);
0536
0537 MODULE_LICENSE("GPL");
0538 MODULE_AUTHOR("Alexandrov Stanislav");
0539 MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");