xref: /openbmc/linux/drivers/hid/hid-elan.c (revision 163a7fbf)
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