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 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
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 *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
105static 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
129static 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
136static 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
146static 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
186static 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
212static 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
261static 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
279static 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
357static 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
376static 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
395static 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
407static 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
420static 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
461static 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
550static 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
570static 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
591static 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
670fail4:
671 if (w8001->pen_dev)
672 input_unregister_device(w8001->pen_dev);
673fail3:
674 serio_close(serio);
675fail2:
676 serio_set_drvdata(serio, NULL);
677fail1:
678 input_free_device(input_dev_pen);
679 input_free_device(input_dev_touch);
680 kfree(w8001);
681 return err;
682}
683
684static 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
694MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
695
696static 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
707module_serio_driver(w8001_drv);
708