1/*
2 * HID Driver for ELAN Touchpad
3 *
4 * Currently only supports touchpad found on HP Pavilion X2 10
5 *
6 * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 */
13
14#include <linux/hid.h>
15#include <linux/input/mt.h>
16#include <linux/leds.h>
17#include <linux/module.h>
18#include <linux/usb.h>
19
20#include "hid-ids.h"
21
22#define ELAN_MT_I2C 0x5d
23#define ELAN_SINGLE_FINGER 0x81
24#define ELAN_MT_FIRST_FINGER 0x82
25#define ELAN_MT_SECOND_FINGER 0x83
26#define ELAN_INPUT_REPORT_SIZE 8
27#define ELAN_I2C_REPORT_SIZE 32
28#define ELAN_FINGER_DATA_LEN 5
29#define ELAN_MAX_FINGERS 5
30#define ELAN_MAX_PRESSURE 255
31#define ELAN_TP_USB_INTF 1
32
33#define ELAN_FEATURE_REPORT 0x0d
34#define ELAN_FEATURE_SIZE 5
35#define ELAN_PARAM_MAX_X 6
36#define ELAN_PARAM_MAX_Y 7
37#define ELAN_PARAM_RES 8
38
39#define ELAN_MUTE_LED_REPORT 0xBC
40#define ELAN_LED_REPORT_SIZE 8
41
42#define ELAN_HAS_LED BIT(0)
43
44struct elan_drvdata {
45 struct input_dev *input;
46 u8 prev_report[ELAN_INPUT_REPORT_SIZE];
47 struct led_classdev mute_led;
48 u8 mute_led_state;
49 u16 max_x;
50 u16 max_y;
51 u16 res_x;
52 u16 res_y;
53};
54
55static int is_not_elan_touchpad(struct hid_device *hdev)
56{
57 if (hdev->bus == BUS_USB) {
58 struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
59
60 return (intf->altsetting->desc.bInterfaceNumber !=
61 ELAN_TP_USB_INTF);
62 }
63
64 return 0;
65}
66
67static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
68 struct hid_field *field, struct hid_usage *usage,
69 unsigned long **bit, int *max)
70{
71 if (is_not_elan_touchpad(hdev))
72 return 0;
73
74 if (field->report->id == ELAN_SINGLE_FINGER ||
75 field->report->id == ELAN_MT_FIRST_FINGER ||
76 field->report->id == ELAN_MT_SECOND_FINGER ||
77 field->report->id == ELAN_MT_I2C)
78 return -1;
79
80 return 0;
81}
82
83static int elan_get_device_param(struct hid_device *hdev,
84 unsigned char *dmabuf, unsigned char param)
85{
86 int ret;
87
88 dmabuf[0] = ELAN_FEATURE_REPORT;
89 dmabuf[1] = 0x05;
90 dmabuf[2] = 0x03;
91 dmabuf[3] = param;
92 dmabuf[4] = 0x01;
93
94 ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
95 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
96 HID_REQ_SET_REPORT);
97 if (ret != ELAN_FEATURE_SIZE) {
98 hid_err(hdev, "Set report error for parm %d: %d\n", param, ret);
99 return ret;
100 }
101
102 ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
103 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
104 HID_REQ_GET_REPORT);
105 if (ret != ELAN_FEATURE_SIZE) {
106 hid_err(hdev, "Get report error for parm %d: %d\n", param, ret);
107 return ret;
108 }
109
110 return 0;
111}
112
113static unsigned int elan_convert_res(char val)
114{
115 /*
116 * (value from firmware) * 10 + 790 = dpi
117 * dpi * 10 / 254 = dots/mm
118 */
119 return (val * 10 + 790) * 10 / 254;
120}
121
122static int elan_get_device_params(struct hid_device *hdev)
123{
124 struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
125 unsigned char *dmabuf;
126 int ret;
127
128 dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL);
129 if (!dmabuf)
130 return -ENOMEM;
131
132 ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X);
133 if (ret)
134 goto err;
135
136 drvdata->max_x = (dmabuf[4] << 8) | dmabuf[3];
137
138 ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y);
139 if (ret)
140 goto err;
141
142 drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3];
143
144 ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES);
145 if (ret)
146 goto err;
147
148 drvdata->res_x = elan_convert_res(dmabuf[3]);
149 drvdata->res_y = elan_convert_res(dmabuf[4]);
150
151err:
152 kfree(dmabuf);
153 return ret;
154}
155
156static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
157{
158 int ret;
159 struct input_dev *input;
160 struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
161
162 if (is_not_elan_touchpad(hdev))
163 return 0;
164
165 ret = elan_get_device_params(hdev);
166 if (ret)
167 return ret;
168
169 input = devm_input_allocate_device(&hdev->dev);
170 if (!input)
171 return -ENOMEM;
172
173 input->name = "Elan Touchpad";
174 input->phys = hdev->phys;
175 input->uniq = hdev->uniq;
176 input->id.bustype = hdev->bus;
177 input->id.vendor = hdev->vendor;
178 input->id.product = hdev->product;
179 input->id.version = hdev->version;
180 input->dev.parent = &hdev->dev;
181
182 input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x,
183 0, 0);
184 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y,
185 0, 0);
186 input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE,
187 0, 0);
188
189 __set_bit(BTN_LEFT, input->keybit);
190 __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
191
192 ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER);
193 if (ret) {
194 hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
195 return ret;
196 }
197
198 input_abs_set_res(input, ABS_X, drvdata->res_x);
199 input_abs_set_res(input, ABS_Y, drvdata->res_y);
200
201 ret = input_register_device(input);
202 if (ret) {
203 hid_err(hdev, "Failed to register elan input device: %d\n",
204 ret);
205 input_free_device(input);
206 return ret;
207 }
208
209 drvdata->input = input;
210
211 return 0;
212}
213
214static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data,
215 unsigned int slot_num)
216{
217 struct input_dev *input = drvdata->input;
218 int x, y, p;
219
220 bool active = !!data;
221
222 input_mt_slot(input, slot_num);
223 input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
224 if (active) {
225 x = ((data[0] & 0xF0) << 4) | data[1];
226 y = drvdata->max_y -
227 (((data[0] & 0x07) << 8) | data[2]);
228 p = data[4];
229
230 input_report_abs(input, ABS_MT_POSITION_X, x);
231 input_report_abs(input, ABS_MT_POSITION_Y, y);
232 input_report_abs(input, ABS_MT_PRESSURE, p);
233 }
234}
235
236static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data)
237{
238 int i;
239 struct input_dev *input = drvdata->input;
240
241 /*
242 * There is 3 types of reports: for single touch,
243 * for multitouch - first finger and for multitouch - second finger
244 *
245 * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
246 *
247 * byte 1: 1 0 0 0 0 0 0 1 // 0x81 or 0x82
248 * byte 2: 0 0 0 0 0 0 0 0 // looks like unused
249 * byte 3: f5 f4 f3 f2 f1 0 0 L
250 * byte 4: x12 x11 x10 x9 0? y11 y10 y9
251 * byte 5: x8 x7 x6 x5 x4 x3 x2 x1
252 * byte 6: y8 y7 y6 y5 y4 y3 y2 y1
253 * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
254 * byte 8: p8 p7 p6 p5 p4 p3 p2 p1
255 *
256 * packet structure for ELAN_MT_SECOND_FINGER:
257 *
258 * byte 1: 1 0 0 0 0 0 1 1 // 0x83
259 * byte 2: x12 x11 x10 x9 0 y11 y10 y9
260 * byte 3: x8 x7 x6 x5 x4 x3 x2 x1
261 * byte 4: y8 y7 y6 y5 y4 y3 y2 y1
262 * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
263 * byte 6: p8 p7 p6 p5 p4 p3 p2 p1
264 * byte 7: 0 0 0 0 0 0 0 0
265 * byte 8: 0 0 0 0 0 0 0 0
266 *
267 * f5-f1: finger touch bits
268 * L: clickpad button
269 * sy / sx: finger width / height expressed in traces, the total number
270 * of traces can be queried by doing a HID_REQ_SET_REPORT
271 * { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the
272 * returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.
273 * p: pressure
274 */
275
276 if (data[0] == ELAN_SINGLE_FINGER) {
277 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
278 if (data[2] & BIT(i + 3))
279 elan_report_mt_slot(drvdata, data + 3, i);
280 else
281 elan_report_mt_slot(drvdata, NULL, i);
282 }
283 input_report_key(input, BTN_LEFT, data[2] & 0x01);
284 }
285 /*
286 * When touched with two fingers Elan touchpad will emit two HID reports
287 * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
288 * we will save ELAN_MT_FIRST_FINGER report and wait for
289 * ELAN_MT_SECOND_FINGER to finish multitouch
290 */
291 if (data[0] == ELAN_MT_FIRST_FINGER) {
292 memcpy(drvdata->prev_report, data,
293 sizeof(drvdata->prev_report));
294 return;
295 }
296
297 if (data[0] == ELAN_MT_SECOND_FINGER) {
298 int first = 0;
299 u8 *prev_report = drvdata->prev_report;
300
301 if (prev_report[0] != ELAN_MT_FIRST_FINGER)
302 return;
303
304 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
305 if (prev_report[2] & BIT(i + 3)) {
306 if (!first) {
307 first = 1;
308 elan_report_mt_slot(drvdata, prev_report + 3, i);
309 } else {
310 elan_report_mt_slot(drvdata, data + 1, i);
311 }
312 } else {
313 elan_report_mt_slot(drvdata, NULL, i);
314 }
315 }
316 input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
317 }
318
319 input_mt_sync_frame(input);
320 input_sync(input);
321}
322
323static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data)
324{
325 struct input_dev *input = drvdata->input;
326 u8 *finger_data;
327 int i;
328
329 /*
330 * Elan MT touchpads in i2c mode send finger data in the same format
331 * as in USB mode, but then with all fingers in a single packet.
332 *
333 * packet structure for ELAN_MT_I2C:
334 *
335 * byte 1: 1 0 0 1 1 1 0 1 // 0x5d
336 * byte 2: f5 f4 f3 f2 f1 0 0 L
337 * byte 3: x12 x11 x10 x9 0? y11 y10 y9
338 * byte 4: x8 x7 x6 x5 x4 x3 x2 x1
339 * byte 5: y8 y7 y6 y5 y4 y3 y2 y1
340 * byte 6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
341 * byte 7: p8 p7 p6 p5 p4 p3 p2 p1
342 * byte 8-12: Same as byte 3-7 for second finger down
343 * byte 13-17: Same as byte 3-7 for third finger down
344 * byte 18-22: Same as byte 3-7 for fourth finger down
345 * byte 23-27: Same as byte 3-7 for fifth finger down
346 */
347
348 finger_data = data + 2;
349 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
350 if (data[1] & BIT(i + 3)) {
351 elan_report_mt_slot(drvdata, finger_data, i);
352 finger_data += ELAN_FINGER_DATA_LEN;
353 } else {
354 elan_report_mt_slot(drvdata, NULL, i);
355 }
356 }
357
358 input_report_key(input, BTN_LEFT, data[1] & 0x01);
359 input_mt_sync_frame(input);
360 input_sync(input);
361}
362
363static int elan_raw_event(struct hid_device *hdev,
364 struct hid_report *report, u8 *data, int size)
365{
366 struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
367
368 if (is_not_elan_touchpad(hdev))
369 return 0;
370
371 if (data[0] == ELAN_SINGLE_FINGER ||
372 data[0] == ELAN_MT_FIRST_FINGER ||
373 data[0] == ELAN_MT_SECOND_FINGER) {
374 if (size == ELAN_INPUT_REPORT_SIZE) {
375 elan_usb_report_input(drvdata, data);
376 return 1;
377 }
378 }
379
380 if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) {
381 elan_i2c_report_input(drvdata, data);
382 return 1;
383 }
384
385 return 0;
386}
387
388static int elan_start_multitouch(struct hid_device *hdev)
389{
390 int ret;
391
392 /*
393 * This byte sequence will enable multitouch mode and disable
394 * mouse emulation
395 */
396 static const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
397 unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);
398
399 if (!dmabuf)
400 return -ENOMEM;
401
402 ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
403 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
404
405 kfree(dmabuf);
406
407 if (ret != sizeof(buf)) {
408 hid_err(hdev, "Failed to start multitouch: %d\n", ret);
409 return ret;
410 }
411
412 return 0;
413}
414
415static enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
416{
417 struct device *dev = led_cdev->dev->parent;
418 struct hid_device *hdev = to_hid_device(dev);
419 struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
420
421 return drvdata->mute_led_state;
422}
423
424static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
425 enum led_brightness value)
426{
427 int ret;
428 u8 led_state;
429 struct device *dev = led_cdev->dev->parent;
430 struct hid_device *hdev = to_hid_device(dev);
431 struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
432
433 unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);
434
435 if (!dmabuf)
436 return -ENOMEM;
437
438 led_state = !!value;
439
440 dmabuf[0] = ELAN_MUTE_LED_REPORT;
441 dmabuf[1] = 0x02;
442 dmabuf[2] = led_state;
443
444 ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
445 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
446
447 kfree(dmabuf);
448
449 if (ret != ELAN_LED_REPORT_SIZE) {
450 hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
451 return ret;
452 }
453
454 drvdata->mute_led_state = led_state;
455 return 0;
456}
457
458static int elan_init_mute_led(struct hid_device *hdev)
459{
460 struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
461 struct led_classdev *mute_led = &drvdata->mute_led;
462
463 mute_led->name = "elan:red:mute";
464 mute_led->brightness_get = elan_mute_led_get_brigtness;
465 mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
466 mute_led->max_brightness = LED_ON;
467 mute_led->dev = &hdev->dev;
468
469 return devm_led_classdev_register(&hdev->dev, mute_led);
470}
471
472static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id)
473{
474 int ret;
475 struct elan_drvdata *drvdata;
476
477 drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
478
479 if (!drvdata)
480 return -ENOMEM;
481
482 hid_set_drvdata(hdev, drvdata);
483
484 ret = hid_parse(hdev);
485 if (ret) {
486 hid_err(hdev, "Hid Parse failed\n");
487 return ret;
488 }
489
490 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
491 if (ret) {
492 hid_err(hdev, "Hid hw start failed\n");
493 return ret;
494 }
495
496 if (is_not_elan_touchpad(hdev))
497 return 0;
498
499 if (!drvdata->input) {
500 hid_err(hdev, "Input device is not registered\n");
501 ret = -ENAVAIL;
502 goto err;
503 }
504
505 ret = elan_start_multitouch(hdev);
506 if (ret)
507 goto err;
508
509 if (id->driver_data & ELAN_HAS_LED) {
510 ret = elan_init_mute_led(hdev);
511 if (ret)
512 goto err;
513 }
514
515 return 0;
516err:
517 hid_hw_stop(hdev);
518 return ret;
519}
520
521static void elan_remove(struct hid_device *hdev)
522{
523 hid_hw_stop(hdev);
524}
525
526static const struct hid_device_id elan_devices[] = {
527 { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),
528 .driver_data = ELAN_HAS_LED },
529 { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
530 .driver_data = ELAN_HAS_LED },
531 { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
532 { }
533};
534MODULE_DEVICE_TABLE(hid, elan_devices);
535
536static struct hid_driver elan_driver = {
537 .name = "elan",
538 .id_table = elan_devices,
539 .input_mapping = elan_input_mapping,
540 .input_configured = elan_input_configured,
541 .raw_event = elan_raw_event,
542 .probe = elan_probe,
543 .remove = elan_remove,
544};
545
546module_hid_driver(elan_driver);
547
548MODULE_LICENSE("GPL");
549MODULE_AUTHOR("Alexandrov Stanislav");
550MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");
551