summaryrefslogtreecommitdiff
path: root/drivers/hid/hid-elan.c
blob: 803a725785cfda738da2fde0d00802cc3990d1da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
/*
 * HID Driver for ELAN Touchpad
 *
 * Currently only supports touchpad found on HP Pavilion X2 10
 *
 * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#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_SINGLE_FINGER	0x81
#define ELAN_MT_FIRST_FINGER	0x82
#define ELAN_MT_SECOND_FINGER	0x83
#define ELAN_INPUT_REPORT_SIZE	8

#define ELAN_MUTE_LED_REPORT	0xBC
#define ELAN_LED_REPORT_SIZE	8

struct elan_touchpad_settings {
	u8 max_fingers;
	u16 max_x;
	u16 max_y;
	u8 max_area_x;
	u8 max_area_y;
	u8 max_w;
	int usb_bInterfaceNumber;
};

struct elan_drvdata {
	struct input_dev *input;
	u8 prev_report[ELAN_INPUT_REPORT_SIZE];
	struct led_classdev mute_led;
	u8 mute_led_state;
	struct elan_touchpad_settings *settings;
};

static int is_not_elan_touchpad(struct hid_device *hdev)
{
	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

	return (intf->altsetting->desc.bInterfaceNumber != drvdata->settings->usb_bInterfaceNumber);
}

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)
		return -1;

	return 0;
}

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;

	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->settings->max_x, 0, 0);
	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
			     drvdata->settings->max_y, 0, 0);
	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0,
			     drvdata->settings->max_fingers, 0, 0);
	input_set_abs_params(input, ABS_TOOL_WIDTH, 0,
			     drvdata->settings->max_w, 0, 0);

	__set_bit(BTN_LEFT, input->keybit);
	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

	ret = input_mt_init_slots(input, drvdata->settings->max_fingers,
				  INPUT_MT_POINTER);
	if (ret) {
		hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
		return ret;
	}

	ret = input_register_device(input);
	if (ret) {
		hid_err(hdev, "Failed to register elan input device: %d\n",
			ret);
		input_free_device(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, w;

	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->settings->max_y -
		    (((data[0] & 0x07) << 8) | data[2]);
		w = 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_TOOL_WIDTH, w);
	}
}

static void elan_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: w8  w7  w6  w5  w4  w3  w2  w1
	 *
	 * 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: w8  w7  w6  w5  w4  w3  w2  w1
	 * 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: not sure yet, but this looks like rectangular
	 * area for finger
	 * w: looks like finger width
	 */

	if (data[0] == ELAN_SINGLE_FINGER) {
		for (i = 0; i < drvdata->settings->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 < drvdata->settings->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 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_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
	 */
	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 enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
{
	struct device *dev = led_cdev->dev->parent;
	struct hid_device *hdev = to_hid_device(dev);
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

	return drvdata->mute_led_state;
}

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) {
		hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
		return ret;
	}

	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->brightness_get = elan_mute_led_get_brigtness;
	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
	mute_led->max_brightness = LED_ON;
	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;

	drvdata->settings = (struct elan_touchpad_settings *)id->driver_data;
	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 registred\n");
		ret = -ENAVAIL;
		goto err;
	}

	ret = elan_start_multitouch(hdev);
	if (ret)
		goto err;

	ret = elan_init_mute_led(hdev);
	if (ret)
		goto err;

	return 0;
err:
	hid_hw_stop(hdev);
	return ret;
}

static void elan_remove(struct hid_device *hdev)
{
	hid_hw_stop(hdev);
}

static const struct elan_touchpad_settings hp_x2_10_touchpad_data = {
	.max_fingers = 5,
	.max_x = 2930,
	.max_y = 1250,
	.max_area_x = 15,
	.max_area_y = 15,
	.max_w = 255,
	.usb_bInterfaceNumber = 1,
};

static const struct hid_device_id elan_devices[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
		(kernel_ulong_t)&hp_x2_10_touchpad_data},
	{ }
};

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,
	.remove = elan_remove,
};

module_hid_driver(elan_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexandrov Stanislav");
MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");