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
26MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
27MODULE_DESCRIPTION(DRIVER_DESC);
28MODULE_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
59struct 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 */
72struct 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
84struct 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
107static 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
131static 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
138static 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
148static 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
188static 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
214static 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
263static 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
281static 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
359static 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
378static 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
397static 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
409static 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
422static 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
463static 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
552static 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
572static 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
593static 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	strscpy(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		strscpy(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		strscpy(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
672fail4:
673	if (w8001->pen_dev)
674		input_unregister_device(w8001->pen_dev);
675fail3:
676	serio_close(serio);
677fail2:
678	serio_set_drvdata(serio, NULL);
679fail1:
680	input_free_device(input_dev_pen);
681	input_free_device(input_dev_touch);
682	kfree(w8001);
683	return err;
684}
685
686static 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
696MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
697
698static 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
709module_serio_driver(w8001_drv);
710