1 /*
2  * Wacom W8001 penabled serial touchscreen driver
3  *
4  * Copyright (c) 2008 Jaya Kumar
5  * Copyright (c) 2010 Red Hat, Inc.
6  * Copyright (c) 2010 - 2011 Ping Cheng, Wacom. <pingc@wacom.com>
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License. See the file COPYING in the main directory of this archive for
10  * more details.
11  *
12  * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
13  */
14 
15 #include <linux/errno.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/input/mt.h>
20 #include <linux/serio.h>
21 #include <linux/ctype.h>
22 #include <linux/delay.h>
23 
24 #define DRIVER_DESC	"Wacom W8001 serial touchscreen driver"
25 
26 MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
27 MODULE_DESCRIPTION(DRIVER_DESC);
28 MODULE_LICENSE("GPL");
29 
30 #define W8001_MAX_PHYS		42
31 
32 #define W8001_MAX_LENGTH	13
33 #define W8001_LEAD_MASK		0x80
34 #define W8001_LEAD_BYTE		0x80
35 #define W8001_TAB_MASK		0x40
36 #define W8001_TAB_BYTE		0x40
37 /* set in first byte of touch data packets */
38 #define W8001_TOUCH_MASK	(0x10 | W8001_LEAD_MASK)
39 #define W8001_TOUCH_BYTE	(0x10 | W8001_LEAD_BYTE)
40 
41 #define W8001_QUERY_PACKET	0x20
42 
43 #define W8001_CMD_STOP		'0'
44 #define W8001_CMD_START		'1'
45 #define W8001_CMD_QUERY		'*'
46 #define W8001_CMD_TOUCHQUERY	'%'
47 
48 /* length of data packets in bytes, depends on device. */
49 #define W8001_PKTLEN_TOUCH93	5
50 #define W8001_PKTLEN_TOUCH9A	7
51 #define W8001_PKTLEN_TPCPEN	9
52 #define W8001_PKTLEN_TPCCTL	11	/* control packet */
53 #define W8001_PKTLEN_TOUCH2FG	13
54 
55 /* resolution in points/mm */
56 #define W8001_PEN_RESOLUTION    100
57 #define W8001_TOUCH_RESOLUTION  10
58 
59 struct w8001_coord {
60 	u8 rdy;
61 	u8 tsw;
62 	u8 f1;
63 	u8 f2;
64 	u16 x;
65 	u16 y;
66 	u16 pen_pressure;
67 	u8 tilt_x;
68 	u8 tilt_y;
69 };
70 
71 /* touch query reply packet */
72 struct w8001_touch_query {
73 	u16 x;
74 	u16 y;
75 	u8 panel_res;
76 	u8 capacity_res;
77 	u8 sensor_id;
78 };
79 
80 /*
81  * Per-touchscreen data.
82  */
83 
84 struct w8001 {
85 	struct input_dev *pen_dev;
86 	struct input_dev *touch_dev;
87 	struct serio *serio;
88 	struct completion cmd_done;
89 	int id;
90 	int idx;
91 	unsigned char response_type;
92 	unsigned char response[W8001_MAX_LENGTH];
93 	unsigned char data[W8001_MAX_LENGTH];
94 	char phys[W8001_MAX_PHYS];
95 	int type;
96 	unsigned int pktlen;
97 	u16 max_touch_x;
98 	u16 max_touch_y;
99 	u16 max_pen_x;
100 	u16 max_pen_y;
101 	char pen_name[64];
102 	char touch_name[64];
103 	int open_count;
104 	struct mutex mutex;
105 };
106 
107 static void parse_pen_data(u8 *data, struct w8001_coord *coord)
108 {
109 	memset(coord, 0, sizeof(*coord));
110 
111 	coord->rdy = data[0] & 0x20;
112 	coord->tsw = data[0] & 0x01;
113 	coord->f1 = data[0] & 0x02;
114 	coord->f2 = data[0] & 0x04;
115 
116 	coord->x = (data[1] & 0x7F) << 9;
117 	coord->x |= (data[2] & 0x7F) << 2;
118 	coord->x |= (data[6] & 0x60) >> 5;
119 
120 	coord->y = (data[3] & 0x7F) << 9;
121 	coord->y |= (data[4] & 0x7F) << 2;
122 	coord->y |= (data[6] & 0x18) >> 3;
123 
124 	coord->pen_pressure = data[5] & 0x7F;
125 	coord->pen_pressure |= (data[6] & 0x07) << 7 ;
126 
127 	coord->tilt_x = data[7] & 0x7F;
128 	coord->tilt_y = data[8] & 0x7F;
129 }
130 
131 static void parse_single_touch(u8 *data, struct w8001_coord *coord)
132 {
133 	coord->x = (data[1] << 7) | data[2];
134 	coord->y = (data[3] << 7) | data[4];
135 	coord->tsw = data[0] & 0x01;
136 }
137 
138 static void scale_touch_coordinates(struct w8001 *w8001,
139 				    unsigned int *x, unsigned int *y)
140 {
141 	if (w8001->max_pen_x && w8001->max_touch_x)
142 		*x = *x * w8001->max_pen_x / w8001->max_touch_x;
143 
144 	if (w8001->max_pen_y && w8001->max_touch_y)
145 		*y = *y * w8001->max_pen_y / w8001->max_touch_y;
146 }
147 
148 static void parse_multi_touch(struct w8001 *w8001)
149 {
150 	struct input_dev *dev = w8001->touch_dev;
151 	unsigned char *data = w8001->data;
152 	unsigned int x, y;
153 	int i;
154 	int count = 0;
155 
156 	for (i = 0; i < 2; i++) {
157 		bool touch = data[0] & (1 << i);
158 
159 		input_mt_slot(dev, i);
160 		input_mt_report_slot_state(dev, MT_TOOL_FINGER, touch);
161 		if (touch) {
162 			x = (data[6 * i + 1] << 7) | data[6 * i + 2];
163 			y = (data[6 * i + 3] << 7) | data[6 * i + 4];
164 			/* data[5,6] and [11,12] is finger capacity */
165 
166 			/* scale to pen maximum */
167 			scale_touch_coordinates(w8001, &x, &y);
168 
169 			input_report_abs(dev, ABS_MT_POSITION_X, x);
170 			input_report_abs(dev, ABS_MT_POSITION_Y, y);
171 			count++;
172 		}
173 	}
174 
175 	/* emulate single touch events when stylus is out of proximity.
176 	 * This is to make single touch backward support consistent
177 	 * across all Wacom single touch devices.
178 	 */
179 	if (w8001->type != BTN_TOOL_PEN &&
180 			    w8001->type != BTN_TOOL_RUBBER) {
181 		w8001->type = count == 1 ? BTN_TOOL_FINGER : KEY_RESERVED;
182 		input_mt_report_pointer_emulation(dev, true);
183 	}
184 
185 	input_sync(dev);
186 }
187 
188 static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
189 {
190 	memset(query, 0, sizeof(*query));
191 
192 	query->panel_res = data[1];
193 	query->sensor_id = data[2] & 0x7;
194 	query->capacity_res = data[7];
195 
196 	query->x = data[3] << 9;
197 	query->x |= data[4] << 2;
198 	query->x |= (data[2] >> 5) & 0x3;
199 
200 	query->y = data[5] << 9;
201 	query->y |= data[6] << 2;
202 	query->y |= (data[2] >> 3) & 0x3;
203 
204 	/* Early days' single-finger touch models need the following defaults */
205 	if (!query->x && !query->y) {
206 		query->x = 1024;
207 		query->y = 1024;
208 		if (query->panel_res)
209 			query->x = query->y = (1 << query->panel_res);
210 		query->panel_res = W8001_TOUCH_RESOLUTION;
211 	}
212 }
213 
214 static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
215 {
216 	struct input_dev *dev = w8001->pen_dev;
217 
218 	/*
219 	 * We have 1 bit for proximity (rdy) and 3 bits for tip, side,
220 	 * side2/eraser. If rdy && f2 are set, this can be either pen + side2,
221 	 * or eraser. Assume:
222 	 * - if dev is already in proximity and f2 is toggled → pen + side2
223 	 * - if dev comes into proximity with f2 set → eraser
224 	 * If f2 disappears after assuming eraser, fake proximity out for
225 	 * eraser and in for pen.
226 	 */
227 
228 	switch (w8001->type) {
229 	case BTN_TOOL_RUBBER:
230 		if (!coord->f2) {
231 			input_report_abs(dev, ABS_PRESSURE, 0);
232 			input_report_key(dev, BTN_TOUCH, 0);
233 			input_report_key(dev, BTN_STYLUS, 0);
234 			input_report_key(dev, BTN_STYLUS2, 0);
235 			input_report_key(dev, BTN_TOOL_RUBBER, 0);
236 			input_sync(dev);
237 			w8001->type = BTN_TOOL_PEN;
238 		}
239 		break;
240 
241 	case BTN_TOOL_FINGER:
242 	case KEY_RESERVED:
243 		w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
244 		break;
245 
246 	default:
247 		input_report_key(dev, BTN_STYLUS2, coord->f2);
248 		break;
249 	}
250 
251 	input_report_abs(dev, ABS_X, coord->x);
252 	input_report_abs(dev, ABS_Y, coord->y);
253 	input_report_abs(dev, ABS_PRESSURE, coord->pen_pressure);
254 	input_report_key(dev, BTN_TOUCH, coord->tsw);
255 	input_report_key(dev, BTN_STYLUS, coord->f1);
256 	input_report_key(dev, w8001->type, coord->rdy);
257 	input_sync(dev);
258 
259 	if (!coord->rdy)
260 		w8001->type = KEY_RESERVED;
261 }
262 
263 static void report_single_touch(struct w8001 *w8001, struct w8001_coord *coord)
264 {
265 	struct input_dev *dev = w8001->touch_dev;
266 	unsigned int x = coord->x;
267 	unsigned int y = coord->y;
268 
269 	/* scale to pen maximum */
270 	scale_touch_coordinates(w8001, &x, &y);
271 
272 	input_report_abs(dev, ABS_X, x);
273 	input_report_abs(dev, ABS_Y, y);
274 	input_report_key(dev, BTN_TOUCH, coord->tsw);
275 
276 	input_sync(dev);
277 
278 	w8001->type = coord->tsw ? BTN_TOOL_FINGER : KEY_RESERVED;
279 }
280 
281 static irqreturn_t w8001_interrupt(struct serio *serio,
282 				   unsigned char data, unsigned int flags)
283 {
284 	struct w8001 *w8001 = serio_get_drvdata(serio);
285 	struct w8001_coord coord;
286 	unsigned char tmp;
287 
288 	w8001->data[w8001->idx] = data;
289 	switch (w8001->idx++) {
290 	case 0:
291 		if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
292 			pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
293 			w8001->idx = 0;
294 		}
295 		break;
296 
297 	case W8001_PKTLEN_TOUCH93 - 1:
298 	case W8001_PKTLEN_TOUCH9A - 1:
299 		tmp = w8001->data[0] & W8001_TOUCH_BYTE;
300 		if (tmp != W8001_TOUCH_BYTE)
301 			break;
302 
303 		if (w8001->pktlen == w8001->idx) {
304 			w8001->idx = 0;
305 			if (w8001->type != BTN_TOOL_PEN &&
306 			    w8001->type != BTN_TOOL_RUBBER) {
307 				parse_single_touch(w8001->data, &coord);
308 				report_single_touch(w8001, &coord);
309 			}
310 		}
311 		break;
312 
313 	/* Pen coordinates packet */
314 	case W8001_PKTLEN_TPCPEN - 1:
315 		tmp = w8001->data[0] & W8001_TAB_MASK;
316 		if (unlikely(tmp == W8001_TAB_BYTE))
317 			break;
318 
319 		tmp = w8001->data[0] & W8001_TOUCH_BYTE;
320 		if (tmp == W8001_TOUCH_BYTE)
321 			break;
322 
323 		w8001->idx = 0;
324 		parse_pen_data(w8001->data, &coord);
325 		report_pen_events(w8001, &coord);
326 		break;
327 
328 	/* control packet */
329 	case W8001_PKTLEN_TPCCTL - 1:
330 		tmp = w8001->data[0] & W8001_TOUCH_MASK;
331 		if (tmp == W8001_TOUCH_BYTE)
332 			break;
333 
334 		w8001->idx = 0;
335 		memcpy(w8001->response, w8001->data, W8001_MAX_LENGTH);
336 		w8001->response_type = W8001_QUERY_PACKET;
337 		complete(&w8001->cmd_done);
338 		break;
339 
340 	/* 2 finger touch packet */
341 	case W8001_PKTLEN_TOUCH2FG - 1:
342 		w8001->idx = 0;
343 		parse_multi_touch(w8001);
344 		break;
345 
346 	default:
347 		/*
348 		 * ThinkPad X60 Tablet PC (pen only device) sometimes
349 		 * sends invalid data packets that are larger than
350 		 * W8001_PKTLEN_TPCPEN. Let's start over again.
351 		 */
352 		if (!w8001->touch_dev && w8001->idx > W8001_PKTLEN_TPCPEN - 1)
353 			w8001->idx = 0;
354 	}
355 
356 	return IRQ_HANDLED;
357 }
358 
359 static int w8001_command(struct w8001 *w8001, unsigned char command,
360 			 bool wait_response)
361 {
362 	int rc;
363 
364 	w8001->response_type = 0;
365 	init_completion(&w8001->cmd_done);
366 
367 	rc = serio_write(w8001->serio, command);
368 	if (rc == 0 && wait_response) {
369 
370 		wait_for_completion_timeout(&w8001->cmd_done, HZ);
371 		if (w8001->response_type != W8001_QUERY_PACKET)
372 			rc = -EIO;
373 	}
374 
375 	return rc;
376 }
377 
378 static int w8001_open(struct input_dev *dev)
379 {
380 	struct w8001 *w8001 = input_get_drvdata(dev);
381 	int err;
382 
383 	err = mutex_lock_interruptible(&w8001->mutex);
384 	if (err)
385 		return err;
386 
387 	if (w8001->open_count++ == 0) {
388 		err = w8001_command(w8001, W8001_CMD_START, false);
389 		if (err)
390 			w8001->open_count--;
391 	}
392 
393 	mutex_unlock(&w8001->mutex);
394 	return err;
395 }
396 
397 static void w8001_close(struct input_dev *dev)
398 {
399 	struct w8001 *w8001 = input_get_drvdata(dev);
400 
401 	mutex_lock(&w8001->mutex);
402 
403 	if (--w8001->open_count == 0)
404 		w8001_command(w8001, W8001_CMD_STOP, false);
405 
406 	mutex_unlock(&w8001->mutex);
407 }
408 
409 static int w8001_detect(struct w8001 *w8001)
410 {
411 	int error;
412 
413 	error = w8001_command(w8001, W8001_CMD_STOP, false);
414 	if (error)
415 		return error;
416 
417 	msleep(250);	/* wait 250ms before querying the device */
418 
419 	return 0;
420 }
421 
422 static int w8001_setup_pen(struct w8001 *w8001, char *basename,
423 			   size_t basename_sz)
424 {
425 	struct input_dev *dev = w8001->pen_dev;
426 	struct w8001_coord coord;
427 	int error;
428 
429 	/* penabled? */
430 	error = w8001_command(w8001, W8001_CMD_QUERY, true);
431 	if (error)
432 		return error;
433 
434 	__set_bit(EV_KEY, dev->evbit);
435 	__set_bit(EV_ABS, dev->evbit);
436 	__set_bit(BTN_TOUCH, dev->keybit);
437 	__set_bit(BTN_TOOL_PEN, dev->keybit);
438 	__set_bit(BTN_TOOL_RUBBER, dev->keybit);
439 	__set_bit(BTN_STYLUS, dev->keybit);
440 	__set_bit(BTN_STYLUS2, dev->keybit);
441 	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
442 
443 	parse_pen_data(w8001->response, &coord);
444 	w8001->max_pen_x = coord.x;
445 	w8001->max_pen_y = coord.y;
446 
447 	input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
448 	input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
449 	input_abs_set_res(dev, ABS_X, W8001_PEN_RESOLUTION);
450 	input_abs_set_res(dev, ABS_Y, W8001_PEN_RESOLUTION);
451 	input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
452 	if (coord.tilt_x && coord.tilt_y) {
453 		input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
454 		input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
455 	}
456 
457 	w8001->id = 0x90;
458 	strlcat(basename, " Penabled", basename_sz);
459 
460 	return 0;
461 }
462 
463 static int w8001_setup_touch(struct w8001 *w8001, char *basename,
464 			     size_t basename_sz)
465 {
466 	struct input_dev *dev = w8001->touch_dev;
467 	struct w8001_touch_query touch;
468 	int error;
469 
470 
471 	/* Touch enabled? */
472 	error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
473 	if (error)
474 		return error;
475 	/*
476 	 * Some non-touch devices may reply to the touch query. But their
477 	 * second byte is empty, which indicates touch is not supported.
478 	 */
479 	if (!w8001->response[1])
480 		return -ENXIO;
481 
482 	__set_bit(EV_KEY, dev->evbit);
483 	__set_bit(EV_ABS, dev->evbit);
484 	__set_bit(BTN_TOUCH, dev->keybit);
485 	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
486 
487 	parse_touchquery(w8001->response, &touch);
488 	w8001->max_touch_x = touch.x;
489 	w8001->max_touch_y = touch.y;
490 
491 	if (w8001->max_pen_x && w8001->max_pen_y) {
492 		/* if pen is supported scale to pen maximum */
493 		touch.x = w8001->max_pen_x;
494 		touch.y = w8001->max_pen_y;
495 		touch.panel_res = W8001_PEN_RESOLUTION;
496 	}
497 
498 	input_set_abs_params(dev, ABS_X, 0, touch.x, 0, 0);
499 	input_set_abs_params(dev, ABS_Y, 0, touch.y, 0, 0);
500 	input_abs_set_res(dev, ABS_X, touch.panel_res);
501 	input_abs_set_res(dev, ABS_Y, touch.panel_res);
502 
503 	switch (touch.sensor_id) {
504 	case 0:
505 	case 2:
506 		w8001->pktlen = W8001_PKTLEN_TOUCH93;
507 		w8001->id = 0x93;
508 		strlcat(basename, " 1FG", basename_sz);
509 		break;
510 
511 	case 1:
512 	case 3:
513 	case 4:
514 		w8001->pktlen = W8001_PKTLEN_TOUCH9A;
515 		strlcat(basename, " 1FG", basename_sz);
516 		w8001->id = 0x9a;
517 		break;
518 
519 	case 5:
520 		w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
521 
522 		__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
523 		error = input_mt_init_slots(dev, 2, 0);
524 		if (error) {
525 			dev_err(&w8001->serio->dev,
526 				"failed to initialize MT slots: %d\n", error);
527 			return error;
528 		}
529 
530 		input_set_abs_params(dev, ABS_MT_POSITION_X,
531 					0, touch.x, 0, 0);
532 		input_set_abs_params(dev, ABS_MT_POSITION_Y,
533 					0, touch.y, 0, 0);
534 		input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
535 					0, MT_TOOL_MAX, 0, 0);
536 		input_abs_set_res(dev, ABS_MT_POSITION_X, touch.panel_res);
537 		input_abs_set_res(dev, ABS_MT_POSITION_Y, touch.panel_res);
538 
539 		strlcat(basename, " 2FG", basename_sz);
540 		if (w8001->max_pen_x && w8001->max_pen_y)
541 			w8001->id = 0xE3;
542 		else
543 			w8001->id = 0xE2;
544 		break;
545 	}
546 
547 	strlcat(basename, " Touchscreen", basename_sz);
548 
549 	return 0;
550 }
551 
552 static void w8001_set_devdata(struct input_dev *dev, struct w8001 *w8001,
553 			      struct serio *serio)
554 {
555 	dev->phys = w8001->phys;
556 	dev->id.bustype = BUS_RS232;
557 	dev->id.product = w8001->id;
558 	dev->id.vendor = 0x056a;
559 	dev->id.version = 0x0100;
560 	dev->open = w8001_open;
561 	dev->close = w8001_close;
562 
563 	dev->dev.parent = &serio->dev;
564 
565 	input_set_drvdata(dev, w8001);
566 }
567 
568 /*
569  * w8001_disconnect() is the opposite of w8001_connect()
570  */
571 
572 static void w8001_disconnect(struct serio *serio)
573 {
574 	struct w8001 *w8001 = serio_get_drvdata(serio);
575 
576 	serio_close(serio);
577 
578 	if (w8001->pen_dev)
579 		input_unregister_device(w8001->pen_dev);
580 	if (w8001->touch_dev)
581 		input_unregister_device(w8001->touch_dev);
582 	kfree(w8001);
583 
584 	serio_set_drvdata(serio, NULL);
585 }
586 
587 /*
588  * w8001_connect() is the routine that is called when someone adds a
589  * new serio device that supports the w8001 protocol and registers it as
590  * an input device.
591  */
592 
593 static int w8001_connect(struct serio *serio, struct serio_driver *drv)
594 {
595 	struct w8001 *w8001;
596 	struct input_dev *input_dev_pen;
597 	struct input_dev *input_dev_touch;
598 	char basename[64];
599 	int err, err_pen, err_touch;
600 
601 	w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
602 	input_dev_pen = input_allocate_device();
603 	input_dev_touch = input_allocate_device();
604 	if (!w8001 || !input_dev_pen || !input_dev_touch) {
605 		err = -ENOMEM;
606 		goto fail1;
607 	}
608 
609 	w8001->serio = serio;
610 	w8001->pen_dev = input_dev_pen;
611 	w8001->touch_dev = input_dev_touch;
612 	mutex_init(&w8001->mutex);
613 	init_completion(&w8001->cmd_done);
614 	snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
615 
616 	serio_set_drvdata(serio, w8001);
617 	err = serio_open(serio, drv);
618 	if (err)
619 		goto fail2;
620 
621 	err = w8001_detect(w8001);
622 	if (err)
623 		goto fail3;
624 
625 	/* For backwards-compatibility we compose the basename based on
626 	 * capabilities and then just append the tool type
627 	 */
628 	strlcpy(basename, "Wacom Serial", sizeof(basename));
629 
630 	err_pen = w8001_setup_pen(w8001, basename, sizeof(basename));
631 	err_touch = w8001_setup_touch(w8001, basename, sizeof(basename));
632 	if (err_pen && err_touch) {
633 		err = -ENXIO;
634 		goto fail3;
635 	}
636 
637 	if (!err_pen) {
638 		strlcpy(w8001->pen_name, basename, sizeof(w8001->pen_name));
639 		strlcat(w8001->pen_name, " Pen", sizeof(w8001->pen_name));
640 		input_dev_pen->name = w8001->pen_name;
641 
642 		w8001_set_devdata(input_dev_pen, w8001, serio);
643 
644 		err = input_register_device(w8001->pen_dev);
645 		if (err)
646 			goto fail3;
647 	} else {
648 		input_free_device(input_dev_pen);
649 		input_dev_pen = NULL;
650 		w8001->pen_dev = NULL;
651 	}
652 
653 	if (!err_touch) {
654 		strlcpy(w8001->touch_name, basename, sizeof(w8001->touch_name));
655 		strlcat(w8001->touch_name, " Finger",
656 			sizeof(w8001->touch_name));
657 		input_dev_touch->name = w8001->touch_name;
658 
659 		w8001_set_devdata(input_dev_touch, w8001, serio);
660 
661 		err = input_register_device(w8001->touch_dev);
662 		if (err)
663 			goto fail4;
664 	} else {
665 		input_free_device(input_dev_touch);
666 		input_dev_touch = NULL;
667 		w8001->touch_dev = NULL;
668 	}
669 
670 	return 0;
671 
672 fail4:
673 	if (w8001->pen_dev)
674 		input_unregister_device(w8001->pen_dev);
675 fail3:
676 	serio_close(serio);
677 fail2:
678 	serio_set_drvdata(serio, NULL);
679 fail1:
680 	input_free_device(input_dev_pen);
681 	input_free_device(input_dev_touch);
682 	kfree(w8001);
683 	return err;
684 }
685 
686 static const struct serio_device_id w8001_serio_ids[] = {
687 	{
688 		.type	= SERIO_RS232,
689 		.proto	= SERIO_W8001,
690 		.id	= SERIO_ANY,
691 		.extra	= SERIO_ANY,
692 	},
693 	{ 0 }
694 };
695 
696 MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
697 
698 static struct serio_driver w8001_drv = {
699 	.driver		= {
700 		.name	= "w8001",
701 	},
702 	.description	= DRIVER_DESC,
703 	.id_table	= w8001_serio_ids,
704 	.interrupt	= w8001_interrupt,
705 	.connect	= w8001_connect,
706 	.disconnect	= w8001_disconnect,
707 };
708 
709 module_serio_driver(w8001_drv);
710