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
is_not_elan_touchpad(struct hid_device * hdev)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
elan_input_mapping(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)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
elan_get_device_param(struct hid_device * hdev,unsigned char * dmabuf,unsigned char param)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
elan_convert_res(char val)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
elan_get_device_params(struct hid_device * hdev)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
elan_input_configured(struct hid_device * hdev,struct hid_input * hi)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
elan_report_mt_slot(struct elan_drvdata * drvdata,u8 * data,unsigned int slot_num)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
elan_usb_report_input(struct elan_drvdata * drvdata,u8 * data)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
elan_i2c_report_input(struct elan_drvdata * drvdata,u8 * data)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
elan_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)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
elan_start_multitouch(struct hid_device * hdev)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
elan_mute_led_set_brigtness(struct led_classdev * led_cdev,enum led_brightness value)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
elan_init_mute_led(struct hid_device * hdev)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
elan_probe(struct hid_device * hdev,const struct hid_device_id * id)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 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 };
518 MODULE_DEVICE_TABLE(hid, elan_devices);
519
520 static 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
529 module_hid_driver(elan_driver);
530
531 MODULE_LICENSE("GPL");
532 MODULE_AUTHOR("Alexandrov Stanislav");
533 MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");
534