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	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 
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 *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 
101 static 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 
125 static 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 
132 static 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 
142 static 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 
182 static 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 
208 static 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 
262 static 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 
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 
347 	return IRQ_HANDLED;
348 }
349 
350 static 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 
369 static 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 
376 static 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 
383 static 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 
499 static 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 
517 static 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 
563 fail3:
564 	serio_close(serio);
565 fail2:
566 	serio_set_drvdata(serio, NULL);
567 fail1:
568 	input_free_device(input_dev);
569 	kfree(w8001);
570 	return err;
571 }
572 
573 static 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 
583 MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
584 
585 static 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 
596 module_serio_driver(w8001_drv);
597