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_LENGTH	11
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
57struct 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 */
70struct 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
82struct w8001 {
83	struct input_dev *dev;
84	struct serio *serio;
85	struct completion cmd_done;
86	int id;
87	int idx;
88	unsigned char response_type;
89	unsigned char response[W8001_MAX_LENGTH];
90	unsigned char data[W8001_MAX_LENGTH];
91	char phys[32];
92	int type;
93	unsigned int pktlen;
94	u16 max_touch_x;
95	u16 max_touch_y;
96	u16 max_pen_x;
97	u16 max_pen_y;
98	char name[64];
99};
100
101static void parse_pen_data(u8 *data, struct w8001_coord *coord)
102{
103	memset(coord, 0, sizeof(*coord));
104
105	coord->rdy = data[0] & 0x20;
106	coord->tsw = data[0] & 0x01;
107	coord->f1 = data[0] & 0x02;
108	coord->f2 = data[0] & 0x04;
109
110	coord->x = (data[1] & 0x7F) << 9;
111	coord->x |= (data[2] & 0x7F) << 2;
112	coord->x |= (data[6] & 0x60) >> 5;
113
114	coord->y = (data[3] & 0x7F) << 9;
115	coord->y |= (data[4] & 0x7F) << 2;
116	coord->y |= (data[6] & 0x18) >> 3;
117
118	coord->pen_pressure = data[5] & 0x7F;
119	coord->pen_pressure |= (data[6] & 0x07) << 7 ;
120
121	coord->tilt_x = data[7] & 0x7F;
122	coord->tilt_y = data[8] & 0x7F;
123}
124
125static void parse_single_touch(u8 *data, struct w8001_coord *coord)
126{
127	coord->x = (data[1] << 7) | data[2];
128	coord->y = (data[3] << 7) | data[4];
129	coord->tsw = data[0] & 0x01;
130}
131
132static void scale_touch_coordinates(struct w8001 *w8001,
133				    unsigned int *x, unsigned int *y)
134{
135	if (w8001->max_pen_x && w8001->max_touch_x)
136		*x = *x * w8001->max_pen_x / w8001->max_touch_x;
137
138	if (w8001->max_pen_y && w8001->max_touch_y)
139		*y = *y * w8001->max_pen_y / w8001->max_touch_y;
140}
141
142static void parse_multi_touch(struct w8001 *w8001)
143{
144	struct input_dev *dev = w8001->dev;
145	unsigned char *data = w8001->data;
146	unsigned int x, y;
147	int i;
148	int count = 0;
149
150	for (i = 0; i < 2; i++) {
151		bool touch = data[0] & (1 << i);
152
153		input_mt_slot(dev, i);
154		input_mt_report_slot_state(dev, MT_TOOL_FINGER, touch);
155		if (touch) {
156			x = (data[6 * i + 1] << 7) | data[6 * i + 2];
157			y = (data[6 * i + 3] << 7) | data[6 * i + 4];
158			/* data[5,6] and [11,12] is finger capacity */
159
160			/* scale to pen maximum */
161			scale_touch_coordinates(w8001, &x, &y);
162
163			input_report_abs(dev, ABS_MT_POSITION_X, x);
164			input_report_abs(dev, ABS_MT_POSITION_Y, y);
165			count++;
166		}
167	}
168
169	/* emulate single touch events when stylus is out of proximity.
170	 * This is to make single touch backward support consistent
171	 * across all Wacom single touch devices.
172	 */
173	if (w8001->type != BTN_TOOL_PEN &&
174			    w8001->type != BTN_TOOL_RUBBER) {
175		w8001->type = count == 1 ? BTN_TOOL_FINGER : KEY_RESERVED;
176		input_mt_report_pointer_emulation(dev, true);
177	}
178
179	input_sync(dev);
180}
181
182static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
183{
184	memset(query, 0, sizeof(*query));
185
186	query->panel_res = data[1];
187	query->sensor_id = data[2] & 0x7;
188	query->capacity_res = data[7];
189
190	query->x = data[3] << 9;
191	query->x |= data[4] << 2;
192	query->x |= (data[2] >> 5) & 0x3;
193
194	query->y = data[5] << 9;
195	query->y |= data[6] << 2;
196	query->y |= (data[2] >> 3) & 0x3;
197
198	/* Early days' single-finger touch models need the following defaults */
199	if (!query->x && !query->y) {
200		query->x = 1024;
201		query->y = 1024;
202		if (query->panel_res)
203			query->x = query->y = (1 << query->panel_res);
204		query->panel_res = W8001_TOUCH_RESOLUTION;
205	}
206}
207
208static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
209{
210	struct input_dev *dev = w8001->dev;
211
212	/*
213	 * We have 1 bit for proximity (rdy) and 3 bits for tip, side,
214	 * side2/eraser. If rdy && f2 are set, this can be either pen + side2,
215	 * or eraser. Assume:
216	 * - if dev is already in proximity and f2 is toggled → pen + side2
217	 * - if dev comes into proximity with f2 set → eraser
218	 * If f2 disappears after assuming eraser, fake proximity out for
219	 * eraser and in for pen.
220	 */
221
222	switch (w8001->type) {
223	case BTN_TOOL_RUBBER:
224		if (!coord->f2) {
225			input_report_abs(dev, ABS_PRESSURE, 0);
226			input_report_key(dev, BTN_TOUCH, 0);
227			input_report_key(dev, BTN_STYLUS, 0);
228			input_report_key(dev, BTN_STYLUS2, 0);
229			input_report_key(dev, BTN_TOOL_RUBBER, 0);
230			input_sync(dev);
231			w8001->type = BTN_TOOL_PEN;
232		}
233		break;
234
235	case BTN_TOOL_FINGER:
236		input_report_key(dev, BTN_TOUCH, 0);
237		input_report_key(dev, BTN_TOOL_FINGER, 0);
238		input_sync(dev);
239		/* fall through */
240
241	case KEY_RESERVED:
242		w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
243		break;
244
245	default:
246		input_report_key(dev, BTN_STYLUS2, coord->f2);
247		break;
248	}
249
250	input_report_abs(dev, ABS_X, coord->x);
251	input_report_abs(dev, ABS_Y, coord->y);
252	input_report_abs(dev, ABS_PRESSURE, coord->pen_pressure);
253	input_report_key(dev, BTN_TOUCH, coord->tsw);
254	input_report_key(dev, BTN_STYLUS, coord->f1);
255	input_report_key(dev, w8001->type, coord->rdy);
256	input_sync(dev);
257
258	if (!coord->rdy)
259		w8001->type = KEY_RESERVED;
260}
261
262static void report_single_touch(struct w8001 *w8001, struct w8001_coord *coord)
263{
264	struct input_dev *dev = w8001->dev;
265	unsigned int x = coord->x;
266	unsigned int y = coord->y;
267
268	/* scale to pen maximum */
269	scale_touch_coordinates(w8001, &x, &y);
270
271	input_report_abs(dev, ABS_X, x);
272	input_report_abs(dev, ABS_Y, y);
273	input_report_key(dev, BTN_TOUCH, coord->tsw);
274	input_report_key(dev, BTN_TOOL_FINGER, 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
347	return IRQ_HANDLED;
348}
349
350static int w8001_command(struct w8001 *w8001, unsigned char command,
351			 bool wait_response)
352{
353	int rc;
354
355	w8001->response_type = 0;
356	init_completion(&w8001->cmd_done);
357
358	rc = serio_write(w8001->serio, command);
359	if (rc == 0 && wait_response) {
360
361		wait_for_completion_timeout(&w8001->cmd_done, HZ);
362		if (w8001->response_type != W8001_QUERY_PACKET)
363			rc = -EIO;
364	}
365
366	return rc;
367}
368
369static int w8001_open(struct input_dev *dev)
370{
371	struct w8001 *w8001 = input_get_drvdata(dev);
372
373	return w8001_command(w8001, W8001_CMD_START, false);
374}
375
376static void w8001_close(struct input_dev *dev)
377{
378	struct w8001 *w8001 = input_get_drvdata(dev);
379
380	w8001_command(w8001, W8001_CMD_STOP, false);
381}
382
383static int w8001_setup(struct w8001 *w8001)
384{
385	struct input_dev *dev = w8001->dev;
386	struct w8001_coord coord;
387	struct w8001_touch_query touch;
388	int error;
389
390	error = w8001_command(w8001, W8001_CMD_STOP, false);
391	if (error)
392		return error;
393
394	msleep(250);	/* wait 250ms before querying the device */
395
396	dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
397	strlcat(w8001->name, "Wacom Serial", sizeof(w8001->name));
398
399	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
400
401	/* penabled? */
402	error = w8001_command(w8001, W8001_CMD_QUERY, true);
403	if (!error) {
404		__set_bit(BTN_TOUCH, dev->keybit);
405		__set_bit(BTN_TOOL_PEN, dev->keybit);
406		__set_bit(BTN_TOOL_RUBBER, dev->keybit);
407		__set_bit(BTN_STYLUS, dev->keybit);
408		__set_bit(BTN_STYLUS2, dev->keybit);
409
410		parse_pen_data(w8001->response, &coord);
411		w8001->max_pen_x = coord.x;
412		w8001->max_pen_y = coord.y;
413
414		input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
415		input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
416		input_abs_set_res(dev, ABS_X, W8001_PEN_RESOLUTION);
417		input_abs_set_res(dev, ABS_Y, W8001_PEN_RESOLUTION);
418		input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
419		if (coord.tilt_x && coord.tilt_y) {
420			input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
421			input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
422		}
423		w8001->id = 0x90;
424		strlcat(w8001->name, " Penabled", sizeof(w8001->name));
425	}
426
427	/* Touch enabled? */
428	error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
429
430	/*
431	 * Some non-touch devices may reply to the touch query. But their
432	 * second byte is empty, which indicates touch is not supported.
433	 */
434	if (!error && w8001->response[1]) {
435		__set_bit(BTN_TOUCH, dev->keybit);
436		__set_bit(BTN_TOOL_FINGER, dev->keybit);
437
438		parse_touchquery(w8001->response, &touch);
439		w8001->max_touch_x = touch.x;
440		w8001->max_touch_y = touch.y;
441
442		if (w8001->max_pen_x && w8001->max_pen_y) {
443			/* if pen is supported scale to pen maximum */
444			touch.x = w8001->max_pen_x;
445			touch.y = w8001->max_pen_y;
446			touch.panel_res = W8001_PEN_RESOLUTION;
447		}
448
449		input_set_abs_params(dev, ABS_X, 0, touch.x, 0, 0);
450		input_set_abs_params(dev, ABS_Y, 0, touch.y, 0, 0);
451		input_abs_set_res(dev, ABS_X, touch.panel_res);
452		input_abs_set_res(dev, ABS_Y, touch.panel_res);
453
454		switch (touch.sensor_id) {
455		case 0:
456		case 2:
457			w8001->pktlen = W8001_PKTLEN_TOUCH93;
458			w8001->id = 0x93;
459			strlcat(w8001->name, " 1FG", sizeof(w8001->name));
460			break;
461
462		case 1:
463		case 3:
464		case 4:
465			w8001->pktlen = W8001_PKTLEN_TOUCH9A;
466			strlcat(w8001->name, " 1FG", sizeof(w8001->name));
467			w8001->id = 0x9a;
468			break;
469
470		case 5:
471			w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
472
473			input_mt_init_slots(dev, 2, 0);
474			input_set_abs_params(dev, ABS_MT_POSITION_X,
475						0, touch.x, 0, 0);
476			input_set_abs_params(dev, ABS_MT_POSITION_Y,
477						0, touch.y, 0, 0);
478			input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
479						0, MT_TOOL_MAX, 0, 0);
480
481			strlcat(w8001->name, " 2FG", sizeof(w8001->name));
482			if (w8001->max_pen_x && w8001->max_pen_y)
483				w8001->id = 0xE3;
484			else
485				w8001->id = 0xE2;
486			break;
487		}
488	}
489
490	strlcat(w8001->name, " Touchscreen", sizeof(w8001->name));
491
492	return 0;
493}
494
495/*
496 * w8001_disconnect() is the opposite of w8001_connect()
497 */
498
499static void w8001_disconnect(struct serio *serio)
500{
501	struct w8001 *w8001 = serio_get_drvdata(serio);
502
503	serio_close(serio);
504
505	input_unregister_device(w8001->dev);
506	kfree(w8001);
507
508	serio_set_drvdata(serio, NULL);
509}
510
511/*
512 * w8001_connect() is the routine that is called when someone adds a
513 * new serio device that supports the w8001 protocol and registers it as
514 * an input device.
515 */
516
517static int w8001_connect(struct serio *serio, struct serio_driver *drv)
518{
519	struct w8001 *w8001;
520	struct input_dev *input_dev;
521	int err;
522
523	w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
524	input_dev = input_allocate_device();
525	if (!w8001 || !input_dev) {
526		err = -ENOMEM;
527		goto fail1;
528	}
529
530	w8001->serio = serio;
531	w8001->dev = input_dev;
532	init_completion(&w8001->cmd_done);
533	snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
534
535	serio_set_drvdata(serio, w8001);
536	err = serio_open(serio, drv);
537	if (err)
538		goto fail2;
539
540	err = w8001_setup(w8001);
541	if (err)
542		goto fail3;
543
544	input_dev->name = w8001->name;
545	input_dev->phys = w8001->phys;
546	input_dev->id.product = w8001->id;
547	input_dev->id.bustype = BUS_RS232;
548	input_dev->id.vendor = 0x056a;
549	input_dev->id.version = 0x0100;
550	input_dev->dev.parent = &serio->dev;
551
552	input_dev->open = w8001_open;
553	input_dev->close = w8001_close;
554
555	input_set_drvdata(input_dev, w8001);
556
557	err = input_register_device(w8001->dev);
558	if (err)
559		goto fail3;
560
561	return 0;
562
563fail3:
564	serio_close(serio);
565fail2:
566	serio_set_drvdata(serio, NULL);
567fail1:
568	input_free_device(input_dev);
569	kfree(w8001);
570	return err;
571}
572
573static struct serio_device_id w8001_serio_ids[] = {
574	{
575		.type	= SERIO_RS232,
576		.proto	= SERIO_W8001,
577		.id	= SERIO_ANY,
578		.extra	= SERIO_ANY,
579	},
580	{ 0 }
581};
582
583MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
584
585static struct serio_driver w8001_drv = {
586	.driver		= {
587		.name	= "w8001",
588	},
589	.description	= DRIVER_DESC,
590	.id_table	= w8001_serio_ids,
591	.interrupt	= w8001_interrupt,
592	.connect	= w8001_connect,
593	.disconnect	= w8001_disconnect,
594};
595
596module_serio_driver(w8001_drv);
597