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