xref: /linux/drivers/input/touchscreen/wacom_w8001.c (revision a1087ef6abedf0bfd60e5e3fddf33192cb2c1325)
1 /*
2  * Wacom W8001 penabled serial touchscreen driver
3  *
4  * Copyright (c) 2008 Jaya Kumar
5  * Copyright (c) 2010 Red Hat, Inc.
6  *
7  * This file is subject to the terms and conditions of the GNU General Public
8  * License. See the file COPYING in the main directory of this archive for
9  * more details.
10  *
11  * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
12  */
13 
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/input.h>
19 #include <linux/serio.h>
20 #include <linux/init.h>
21 #include <linux/ctype.h>
22 
23 #define DRIVER_DESC	"Wacom W8001 serial touchscreen driver"
24 
25 MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
26 MODULE_DESCRIPTION(DRIVER_DESC);
27 MODULE_LICENSE("GPL");
28 
29 #define W8001_MAX_LENGTH	11
30 #define W8001_LEAD_MASK		0x80
31 #define W8001_LEAD_BYTE		0x80
32 #define W8001_TAB_MASK		0x40
33 #define W8001_TAB_BYTE		0x40
34 /* set in first byte of touch data packets */
35 #define W8001_TOUCH_MASK	(0x10 | W8001_LEAD_MASK)
36 #define W8001_TOUCH_BYTE	(0x10 | W8001_LEAD_BYTE)
37 
38 #define W8001_QUERY_PACKET	0x20
39 
40 #define W8001_CMD_START		'1'
41 #define W8001_CMD_QUERY		'*'
42 #define W8001_CMD_TOUCHQUERY	'%'
43 
44 /* length of data packets in bytes, depends on device. */
45 #define W8001_PKTLEN_TOUCH93	5
46 #define W8001_PKTLEN_TOUCH9A	7
47 #define W8001_PKTLEN_TPCPEN	9
48 #define W8001_PKTLEN_TPCCTL	11	/* control packet */
49 #define W8001_PKTLEN_TOUCH2FG	13
50 
51 #define MAX_TRACKING_ID		0xFF	/* arbitrarily chosen */
52 
53 struct w8001_coord {
54 	u8 rdy;
55 	u8 tsw;
56 	u8 f1;
57 	u8 f2;
58 	u16 x;
59 	u16 y;
60 	u16 pen_pressure;
61 	u8 tilt_x;
62 	u8 tilt_y;
63 };
64 
65 /* touch query reply packet */
66 struct w8001_touch_query {
67 	u8 panel_res;
68 	u8 capacity_res;
69 	u8 sensor_id;
70 	u16 x;
71 	u16 y;
72 };
73 
74 /*
75  * Per-touchscreen data.
76  */
77 
78 struct w8001 {
79 	struct input_dev *dev;
80 	struct serio *serio;
81 	struct completion cmd_done;
82 	int id;
83 	int idx;
84 	unsigned char response_type;
85 	unsigned char response[W8001_MAX_LENGTH];
86 	unsigned char data[W8001_MAX_LENGTH];
87 	char phys[32];
88 	int type;
89 	unsigned int pktlen;
90 	int trkid[2];
91 };
92 
93 static void parse_data(u8 *data, struct w8001_coord *coord)
94 {
95 	memset(coord, 0, sizeof(*coord));
96 
97 	coord->rdy = data[0] & 0x20;
98 	coord->tsw = data[0] & 0x01;
99 	coord->f1 = data[0] & 0x02;
100 	coord->f2 = data[0] & 0x04;
101 
102 	coord->x = (data[1] & 0x7F) << 9;
103 	coord->x |= (data[2] & 0x7F) << 2;
104 	coord->x |= (data[6] & 0x60) >> 5;
105 
106 	coord->y = (data[3] & 0x7F) << 9;
107 	coord->y |= (data[4] & 0x7F) << 2;
108 	coord->y |= (data[6] & 0x18) >> 3;
109 
110 	coord->pen_pressure = data[5] & 0x7F;
111 	coord->pen_pressure |= (data[6] & 0x07) << 7 ;
112 
113 	coord->tilt_x = data[7] & 0x7F;
114 	coord->tilt_y = data[8] & 0x7F;
115 }
116 
117 static void parse_touch(struct w8001 *w8001)
118 {
119 	static int trkid;
120 	struct input_dev *dev = w8001->dev;
121 	unsigned char *data = w8001->data;
122 	int i;
123 
124 	for (i = 0; i < 2; i++) {
125 		input_mt_slot(dev, i);
126 
127 		if (data[0] & (1 << i)) {
128 			int x = (data[6 * i + 1] << 7) | (data[6 * i + 2]);
129 			int y = (data[6 * i + 3] << 7) | (data[6 * i + 4]);
130 			/* data[5,6] and [11,12] is finger capacity */
131 
132 			input_report_abs(dev, ABS_MT_POSITION_X, x);
133 			input_report_abs(dev, ABS_MT_POSITION_Y, y);
134 			input_report_abs(dev, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER);
135 			if (w8001->trkid[i] < 0)
136 				w8001->trkid[i] = trkid++ & MAX_TRACKING_ID;
137 		} else {
138 			w8001->trkid[i] = -1;
139 		}
140 		input_report_abs(dev, ABS_MT_TRACKING_ID, w8001->trkid[i]);
141 	}
142 
143 	input_sync(dev);
144 }
145 
146 static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
147 {
148 	memset(query, 0, sizeof(*query));
149 
150 	query->panel_res = data[1];
151 	query->sensor_id = data[2] & 0x7;
152 	query->capacity_res = data[7];
153 
154 	query->x = data[3] << 9;
155 	query->x |= data[4] << 2;
156 	query->x |= (data[2] >> 5) & 0x3;
157 
158 	query->y = data[5] << 9;
159 	query->y |= data[6] << 2;
160 	query->y |= (data[2] >> 3) & 0x3;
161 }
162 
163 static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
164 {
165 	struct input_dev *dev = w8001->dev;
166 
167 	/*
168 	 * We have 1 bit for proximity (rdy) and 3 bits for tip, side,
169 	 * side2/eraser. If rdy && f2 are set, this can be either pen + side2,
170 	 * or eraser. assume
171 	 * - if dev is already in proximity and f2 is toggled → pen + side2
172 	 * - if dev comes into proximity with f2 set → eraser
173 	 * If f2 disappears after assuming eraser, fake proximity out for
174 	 * eraser and in for pen.
175 	 */
176 
177 	if (!w8001->type) {
178 		w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
179 	} else if (w8001->type == BTN_TOOL_RUBBER) {
180 		if (!coord->f2) {
181 			input_report_abs(dev, ABS_PRESSURE, 0);
182 			input_report_key(dev, BTN_TOUCH, 0);
183 			input_report_key(dev, BTN_STYLUS, 0);
184 			input_report_key(dev, BTN_STYLUS2, 0);
185 			input_report_key(dev, BTN_TOOL_RUBBER, 0);
186 			input_sync(dev);
187 			w8001->type = BTN_TOOL_PEN;
188 		}
189 	} else {
190 		input_report_key(dev, BTN_STYLUS2, coord->f2);
191 	}
192 
193 	input_report_abs(dev, ABS_X, coord->x);
194 	input_report_abs(dev, ABS_Y, coord->y);
195 	input_report_abs(dev, ABS_PRESSURE, coord->pen_pressure);
196 	input_report_key(dev, BTN_TOUCH, coord->tsw);
197 	input_report_key(dev, BTN_STYLUS, coord->f1);
198 	input_report_key(dev, w8001->type, coord->rdy);
199 	input_sync(dev);
200 
201 	if (!coord->rdy)
202 		w8001->type = 0;
203 }
204 
205 static irqreturn_t w8001_interrupt(struct serio *serio,
206 				   unsigned char data, unsigned int flags)
207 {
208 	struct w8001 *w8001 = serio_get_drvdata(serio);
209 	struct w8001_coord coord;
210 	unsigned char tmp;
211 
212 	w8001->data[w8001->idx] = data;
213 	switch (w8001->idx++) {
214 	case 0:
215 		if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
216 			pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
217 			w8001->idx = 0;
218 		}
219 		break;
220 
221 	case W8001_PKTLEN_TOUCH93 - 1:
222 	case W8001_PKTLEN_TOUCH9A - 1:
223 		/* ignore one-finger touch packet. */
224 		if (w8001->pktlen == w8001->idx)
225 			w8001->idx = 0;
226 		break;
227 
228 	/* Pen coordinates packet */
229 	case W8001_PKTLEN_TPCPEN - 1:
230 		tmp = w8001->data[0] & W8001_TAB_MASK;
231 		if (unlikely(tmp == W8001_TAB_BYTE))
232 			break;
233 
234 		tmp = (w8001->data[0] & W8001_TOUCH_BYTE);
235 		if (tmp == W8001_TOUCH_BYTE)
236 			break;
237 
238 		w8001->idx = 0;
239 		parse_data(w8001->data, &coord);
240 		report_pen_events(w8001, &coord);
241 		break;
242 
243 	/* control packet */
244 	case W8001_PKTLEN_TPCCTL - 1:
245 		tmp = (w8001->data[0] & W8001_TOUCH_MASK);
246 		if (tmp == W8001_TOUCH_BYTE)
247 			break;
248 
249 		w8001->idx = 0;
250 		memcpy(w8001->response, w8001->data, W8001_MAX_LENGTH);
251 		w8001->response_type = W8001_QUERY_PACKET;
252 		complete(&w8001->cmd_done);
253 		break;
254 
255 	/* 2 finger touch packet */
256 	case W8001_PKTLEN_TOUCH2FG - 1:
257 		w8001->idx = 0;
258 		parse_touch(w8001);
259 		break;
260 	}
261 
262 	return IRQ_HANDLED;
263 }
264 
265 static int w8001_command(struct w8001 *w8001, unsigned char command,
266 			 bool wait_response)
267 {
268 	int rc;
269 
270 	w8001->response_type = 0;
271 	init_completion(&w8001->cmd_done);
272 
273 	rc = serio_write(w8001->serio, command);
274 	if (rc == 0 && wait_response) {
275 
276 		wait_for_completion_timeout(&w8001->cmd_done, HZ);
277 		if (w8001->response_type != W8001_QUERY_PACKET)
278 			rc = -EIO;
279 	}
280 
281 	return rc;
282 }
283 
284 static int w8001_setup(struct w8001 *w8001)
285 {
286 	struct input_dev *dev = w8001->dev;
287 	struct w8001_coord coord;
288 	int error;
289 
290 	error = w8001_command(w8001, W8001_CMD_QUERY, true);
291 	if (error)
292 		return error;
293 
294 	parse_data(w8001->response, &coord);
295 
296 	input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
297 	input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
298 	input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
299 	input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
300 	input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
301 
302 	error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
303 	if (!error) {
304 		struct w8001_touch_query touch;
305 
306 		parse_touchquery(w8001->response, &touch);
307 
308 		switch (touch.sensor_id) {
309 		case 0:
310 		case 2:
311 			w8001->pktlen = W8001_PKTLEN_TOUCH93;
312 			break;
313 		case 1:
314 		case 3:
315 		case 4:
316 			w8001->pktlen = W8001_PKTLEN_TOUCH9A;
317 			break;
318 		case 5:
319 			w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
320 
321 			input_mt_create_slots(dev, 2);
322 			input_set_abs_params(dev, ABS_MT_TRACKING_ID,
323 						0, MAX_TRACKING_ID, 0, 0);
324 			input_set_abs_params(dev, ABS_MT_POSITION_X,
325 						0, touch.x, 0, 0);
326 			input_set_abs_params(dev, ABS_MT_POSITION_Y,
327 						0, touch.y, 0, 0);
328 			input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
329 						0, 0, 0, 0);
330 			break;
331 		}
332 	}
333 
334 	return w8001_command(w8001, W8001_CMD_START, false);
335 }
336 
337 /*
338  * w8001_disconnect() is the opposite of w8001_connect()
339  */
340 
341 static void w8001_disconnect(struct serio *serio)
342 {
343 	struct w8001 *w8001 = serio_get_drvdata(serio);
344 
345 	input_get_device(w8001->dev);
346 	input_unregister_device(w8001->dev);
347 	serio_close(serio);
348 	serio_set_drvdata(serio, NULL);
349 	input_put_device(w8001->dev);
350 	kfree(w8001);
351 }
352 
353 /*
354  * w8001_connect() is the routine that is called when someone adds a
355  * new serio device that supports the w8001 protocol and registers it as
356  * an input device.
357  */
358 
359 static int w8001_connect(struct serio *serio, struct serio_driver *drv)
360 {
361 	struct w8001 *w8001;
362 	struct input_dev *input_dev;
363 	int err;
364 
365 	w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
366 	input_dev = input_allocate_device();
367 	if (!w8001 || !input_dev) {
368 		err = -ENOMEM;
369 		goto fail1;
370 	}
371 
372 	w8001->serio = serio;
373 	w8001->id = serio->id.id;
374 	w8001->dev = input_dev;
375 	w8001->trkid[0] = w8001->trkid[1] = -1;
376 	init_completion(&w8001->cmd_done);
377 	snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
378 
379 	input_dev->name = "Wacom W8001 Penabled Serial TouchScreen";
380 	input_dev->phys = w8001->phys;
381 	input_dev->id.bustype = BUS_RS232;
382 	input_dev->id.vendor = SERIO_W8001;
383 	input_dev->id.product = w8001->id;
384 	input_dev->id.version = 0x0100;
385 	input_dev->dev.parent = &serio->dev;
386 
387 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
388 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
389 	input_dev->keybit[BIT_WORD(BTN_TOOL_PEN)] |= BIT_MASK(BTN_TOOL_PEN);
390 	input_dev->keybit[BIT_WORD(BTN_TOOL_RUBBER)] |= BIT_MASK(BTN_TOOL_RUBBER);
391 	input_dev->keybit[BIT_WORD(BTN_STYLUS)] |= BIT_MASK(BTN_STYLUS);
392 	input_dev->keybit[BIT_WORD(BTN_STYLUS2)] |= BIT_MASK(BTN_STYLUS2);
393 
394 	serio_set_drvdata(serio, w8001);
395 	err = serio_open(serio, drv);
396 	if (err)
397 		goto fail2;
398 
399 	err = w8001_setup(w8001);
400 	if (err)
401 		goto fail3;
402 
403 	err = input_register_device(w8001->dev);
404 	if (err)
405 		goto fail3;
406 
407 	return 0;
408 
409 fail3:
410 	serio_close(serio);
411 fail2:
412 	serio_set_drvdata(serio, NULL);
413 fail1:
414 	input_free_device(input_dev);
415 	kfree(w8001);
416 	return err;
417 }
418 
419 static struct serio_device_id w8001_serio_ids[] = {
420 	{
421 		.type	= SERIO_RS232,
422 		.proto	= SERIO_W8001,
423 		.id	= SERIO_ANY,
424 		.extra	= SERIO_ANY,
425 	},
426 	{ 0 }
427 };
428 
429 MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
430 
431 static struct serio_driver w8001_drv = {
432 	.driver		= {
433 		.name	= "w8001",
434 	},
435 	.description	= DRIVER_DESC,
436 	.id_table	= w8001_serio_ids,
437 	.interrupt	= w8001_interrupt,
438 	.connect	= w8001_connect,
439 	.disconnect	= w8001_disconnect,
440 };
441 
442 static int __init w8001_init(void)
443 {
444 	return serio_register_driver(&w8001_drv);
445 }
446 
447 static void __exit w8001_exit(void)
448 {
449 	serio_unregister_driver(&w8001_drv);
450 }
451 
452 module_init(w8001_init);
453 module_exit(w8001_exit);
454