1 /*
2  * Wacom protocol 4 serial tablet driver
3  *
4  * Copyright 2014      Hans de Goede <hdegoede@redhat.com>
5  * Copyright 2011-2012 Julian Squires <julian@cipht.net>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the
9  * Free Software Foundation; either version of 2 of the License, or (at your
10  * option) any later version. See the file COPYING in the main directory of
11  * this archive for more details.
12  *
13  * Many thanks to Bill Seremetis, without whom PenPartner support
14  * would not have been possible. Thanks to Patrick Mahoney.
15  *
16  * This driver was developed with reference to much code written by others,
17  * particularly:
18  *  - elo, gunze drivers by Vojtech Pavlik <vojtech@ucw.cz>;
19  *  - wacom_w8001 driver by Jaya Kumar <jayakumar.lkml@gmail.com>;
20  *  - the USB wacom input driver, credited to many people
21  *    (see drivers/input/tablet/wacom.h);
22  *  - new and old versions of linuxwacom / xf86-input-wacom credited to
23  *    Frederic Lepied, France. <Lepied@XFree86.org> and
24  *    Ping Cheng, Wacom. <pingc@wacom.com>;
25  *  - and xf86wacom.c (a presumably ancient version of the linuxwacom code),
26  *    by Frederic Lepied and Raph Levien <raph@gtk.org>.
27  *
28  * To do:
29  *  - support pad buttons; (requires access to a model with pad buttons)
30  *  - support (protocol 4-style) tilt (requires access to a > 1.4 rom model)
31  */
32 
33 /*
34  * Wacom serial protocol 4 documentation taken from linuxwacom-0.9.9 code,
35  * protocol 4 uses 7 or 9 byte of data in the following format:
36  *
37  *	Byte 1
38  *	bit 7  Sync bit always 1
39  *	bit 6  Pointing device detected
40  *	bit 5  Cursor = 0 / Stylus = 1
41  *	bit 4  Reserved
42  *	bit 3  1 if a button on the pointing device has been pressed
43  *	bit 2  P0 (optional)
44  *	bit 1  X15
45  *	bit 0  X14
46  *
47  *	Byte 2
48  *	bit 7  Always 0
49  *	bits 6-0 = X13 - X7
50  *
51  *	Byte 3
52  *	bit 7  Always 0
53  *	bits 6-0 = X6 - X0
54  *
55  *	Byte 4
56  *	bit 7  Always 0
57  *	bit 6  B3
58  *	bit 5  B2
59  *	bit 4  B1
60  *	bit 3  B0
61  *	bit 2  P1 (optional)
62  *	bit 1  Y15
63  *	bit 0  Y14
64  *
65  *	Byte 5
66  *	bit 7  Always 0
67  *	bits 6-0 = Y13 - Y7
68  *
69  *	Byte 6
70  *	bit 7  Always 0
71  *	bits 6-0 = Y6 - Y0
72  *
73  *	Byte 7
74  *	bit 7 Always 0
75  *	bit 6  Sign of pressure data; or wheel-rel for cursor tool
76  *	bit 5  P7; or REL1 for cursor tool
77  *	bit 4  P6; or REL0 for cursor tool
78  *	bit 3  P5
79  *	bit 2  P4
80  *	bit 1  P3
81  *	bit 0  P2
82  *
83  *	byte 8 and 9 are optional and present only
84  *	in tilt mode.
85  *
86  *	Byte 8
87  *	bit 7 Always 0
88  *	bit 6 Sign of tilt X
89  *	bit 5  Xt6
90  *	bit 4  Xt5
91  *	bit 3  Xt4
92  *	bit 2  Xt3
93  *	bit 1  Xt2
94  *	bit 0  Xt1
95  *
96  *	Byte 9
97  *	bit 7 Always 0
98  *	bit 6 Sign of tilt Y
99  *	bit 5  Yt6
100  *	bit 4  Yt5
101  *	bit 3  Yt4
102  *	bit 2  Yt3
103  *	bit 1  Yt2
104  *	bit 0  Yt1
105  */
106 
107 #include <linux/completion.h>
108 #include <linux/init.h>
109 #include <linux/input.h>
110 #include <linux/interrupt.h>
111 #include <linux/kernel.h>
112 #include <linux/module.h>
113 #include <linux/serio.h>
114 #include <linux/slab.h>
115 #include <linux/string.h>
116 
117 MODULE_AUTHOR("Julian Squires <julian@cipht.net>, Hans de Goede <hdegoede@redhat.com>");
118 MODULE_DESCRIPTION("Wacom protocol 4 serial tablet driver");
119 MODULE_LICENSE("GPL");
120 
121 #define REQUEST_MODEL_AND_ROM_VERSION	"~#"
122 #define REQUEST_MAX_COORDINATES		"~C\r"
123 #define REQUEST_CONFIGURATION_STRING	"~R\r"
124 #define REQUEST_RESET_TO_PROTOCOL_IV	"\r#"
125 /*
126  * Note: sending "\r$\r" causes at least the Digitizer II to send
127  * packets in ASCII instead of binary.  "\r#" seems to undo that.
128  */
129 
130 #define COMMAND_START_SENDING_PACKETS		"ST\r"
131 #define COMMAND_STOP_SENDING_PACKETS		"SP\r"
132 #define COMMAND_MULTI_MODE_INPUT		"MU1\r"
133 #define COMMAND_ORIGIN_IN_UPPER_LEFT		"OC1\r"
134 #define COMMAND_ENABLE_ALL_MACRO_BUTTONS	"~M0\r"
135 #define COMMAND_DISABLE_GROUP_1_MACRO_BUTTONS	"~M1\r"
136 #define COMMAND_TRANSMIT_AT_MAX_RATE		"IT0\r"
137 #define COMMAND_DISABLE_INCREMENTAL_MODE	"IN0\r"
138 #define COMMAND_ENABLE_CONTINUOUS_MODE		"SR\r"
139 #define COMMAND_ENABLE_PRESSURE_MODE		"PH1\r"
140 #define COMMAND_Z_FILTER			"ZF1\r"
141 
142 /* Note that this is a protocol 4 packet without tilt information. */
143 #define PACKET_LENGTH		7
144 #define DATA_SIZE		32
145 
146 /* flags */
147 #define F_COVERS_SCREEN		0x01
148 #define F_HAS_STYLUS2		0x02
149 #define F_HAS_SCROLLWHEEL	0x04
150 
151 /* device IDs */
152 #define STYLUS_DEVICE_ID	0x02
153 #define CURSOR_DEVICE_ID	0x06
154 #define ERASER_DEVICE_ID	0x0A
155 
156 enum { STYLUS = 1, ERASER, CURSOR };
157 
158 static const struct {
159 	int device_id;
160 	int input_id;
161 } tools[] = {
162 	{ 0, 0 },
163 	{ STYLUS_DEVICE_ID, BTN_TOOL_PEN },
164 	{ ERASER_DEVICE_ID, BTN_TOOL_RUBBER },
165 	{ CURSOR_DEVICE_ID, BTN_TOOL_MOUSE },
166 };
167 
168 struct wacom {
169 	struct input_dev *dev;
170 	struct completion cmd_done;
171 	int result;
172 	u8 expect;
173 	u8 eraser_mask;
174 	unsigned int extra_z_bits;
175 	unsigned int flags;
176 	unsigned int res_x, res_y;
177 	unsigned int max_x, max_y;
178 	unsigned int tool;
179 	unsigned int idx;
180 	u8 data[DATA_SIZE];
181 	char phys[32];
182 };
183 
184 enum {
185 	MODEL_CINTIQ		= 0x504C, /* PL */
186 	MODEL_CINTIQ2		= 0x4454, /* DT */
187 	MODEL_DIGITIZER_II	= 0x5544, /* UD */
188 	MODEL_GRAPHIRE		= 0x4554, /* ET */
189 	MODEL_PENPARTNER	= 0x4354, /* CT */
190 };
191 
192 static void wacom_handle_model_response(struct wacom *wacom)
193 {
194 	int major_v, minor_v, r = 0;
195 	char *p;
196 
197 	p = strrchr(wacom->data, 'V');
198 	if (p)
199 		r = sscanf(p + 1, "%u.%u", &major_v, &minor_v);
200 	if (r != 2)
201 		major_v = minor_v = 0;
202 
203 	switch (wacom->data[2] << 8 | wacom->data[3]) {
204 	case MODEL_CINTIQ:	/* UNTESTED */
205 	case MODEL_CINTIQ2:
206 		if ((wacom->data[2] << 8 | wacom->data[3]) == MODEL_CINTIQ) {
207 			wacom->dev->name = "Wacom Cintiq";
208 			wacom->dev->id.version = MODEL_CINTIQ;
209 		} else {
210 			wacom->dev->name = "Wacom Cintiq II";
211 			wacom->dev->id.version = MODEL_CINTIQ2;
212 		}
213 		wacom->res_x = 508;
214 		wacom->res_y = 508;
215 
216 		switch (wacom->data[5] << 8 | wacom->data[6]) {
217 		case 0x3731: /* PL-710 */
218 			wacom->res_x = 2540;
219 			wacom->res_y = 2540;
220 			/* fall through */
221 		case 0x3535: /* PL-550 */
222 		case 0x3830: /* PL-800 */
223 			wacom->extra_z_bits = 2;
224 		}
225 
226 		wacom->flags = F_COVERS_SCREEN;
227 		break;
228 
229 	case MODEL_PENPARTNER:
230 		wacom->dev->name = "Wacom Penpartner";
231 		wacom->dev->id.version = MODEL_PENPARTNER;
232 		wacom->res_x = 1000;
233 		wacom->res_y = 1000;
234 		break;
235 
236 	case MODEL_GRAPHIRE:
237 		wacom->dev->name = "Wacom Graphire";
238 		wacom->dev->id.version = MODEL_GRAPHIRE;
239 		wacom->res_x = 1016;
240 		wacom->res_y = 1016;
241 		wacom->max_x = 5103;
242 		wacom->max_y = 3711;
243 		wacom->extra_z_bits = 2;
244 		wacom->eraser_mask = 0x08;
245 		wacom->flags = F_HAS_STYLUS2 | F_HAS_SCROLLWHEEL;
246 		break;
247 
248 	case MODEL_DIGITIZER_II:
249 		wacom->dev->name = "Wacom Digitizer II";
250 		wacom->dev->id.version = MODEL_DIGITIZER_II;
251 		if (major_v == 1 && minor_v <= 2)
252 			wacom->extra_z_bits = 0; /* UNTESTED */
253 		break;
254 
255 	default:
256 		dev_err(&wacom->dev->dev, "Unsupported Wacom model %s\n",
257 			wacom->data);
258 		wacom->result = -ENODEV;
259 		return;
260 	}
261 
262 	dev_info(&wacom->dev->dev, "%s tablet, version %u.%u\n",
263 		 wacom->dev->name, major_v, minor_v);
264 }
265 
266 static void wacom_handle_configuration_response(struct wacom *wacom)
267 {
268 	int r, skip;
269 
270 	dev_dbg(&wacom->dev->dev, "Configuration string: %s\n", wacom->data);
271 	r = sscanf(wacom->data, "~R%x,%u,%u,%u,%u", &skip, &skip, &skip,
272 		   &wacom->res_x, &wacom->res_y);
273 	if (r != 5)
274 		dev_warn(&wacom->dev->dev, "could not get resolution\n");
275 }
276 
277 static void wacom_handle_coordinates_response(struct wacom *wacom)
278 {
279 	int r;
280 
281 	dev_dbg(&wacom->dev->dev, "Coordinates string: %s\n", wacom->data);
282 	r = sscanf(wacom->data, "~C%u,%u", &wacom->max_x, &wacom->max_y);
283 	if (r != 2)
284 		dev_warn(&wacom->dev->dev, "could not get max coordinates\n");
285 }
286 
287 static void wacom_handle_response(struct wacom *wacom)
288 {
289 	if (wacom->data[0] != '~' || wacom->data[1] != wacom->expect) {
290 		dev_err(&wacom->dev->dev,
291 			"Wacom got an unexpected response: %s\n", wacom->data);
292 		wacom->result = -EIO;
293 	} else {
294 		wacom->result = 0;
295 
296 		switch (wacom->data[1]) {
297 		case '#':
298 			wacom_handle_model_response(wacom);
299 			break;
300 		case 'R':
301 			wacom_handle_configuration_response(wacom);
302 			break;
303 		case 'C':
304 			wacom_handle_coordinates_response(wacom);
305 			break;
306 		}
307 	}
308 
309 	complete(&wacom->cmd_done);
310 }
311 
312 static void wacom_handle_packet(struct wacom *wacom)
313 {
314 	u8 in_proximity_p, stylus_p, button;
315 	unsigned int tool;
316 	int x, y, z;
317 
318 	in_proximity_p = wacom->data[0] & 0x40;
319 	stylus_p = wacom->data[0] & 0x20;
320 	button = (wacom->data[3] & 0x78) >> 3;
321 	x = (wacom->data[0] & 3) << 14 | wacom->data[1]<<7 | wacom->data[2];
322 	y = (wacom->data[3] & 3) << 14 | wacom->data[4]<<7 | wacom->data[5];
323 
324 	if (in_proximity_p && stylus_p) {
325 		z = wacom->data[6] & 0x7f;
326 		if (wacom->extra_z_bits >= 1)
327 			z = z << 1 | (wacom->data[3] & 0x4) >> 2;
328 		if (wacom->extra_z_bits > 1)
329 			z = z << 1 | (wacom->data[0] & 0x4) >> 2;
330 		z = z ^ (0x40 << wacom->extra_z_bits);
331 	} else {
332 		z = -1;
333 	}
334 
335 	if (stylus_p)
336 		tool = (button & wacom->eraser_mask) ? ERASER : STYLUS;
337 	else
338 		tool = CURSOR;
339 
340 	if (tool != wacom->tool && wacom->tool != 0) {
341 		input_report_key(wacom->dev, tools[wacom->tool].input_id, 0);
342 		input_sync(wacom->dev);
343 	}
344 	wacom->tool = tool;
345 
346 	input_report_key(wacom->dev, tools[tool].input_id, in_proximity_p);
347 	input_report_abs(wacom->dev, ABS_MISC,
348 			 in_proximity_p ? tools[tool].device_id : 0);
349 	input_report_abs(wacom->dev, ABS_X, x);
350 	input_report_abs(wacom->dev, ABS_Y, y);
351 	input_report_abs(wacom->dev, ABS_PRESSURE, z);
352 	if (stylus_p) {
353 		input_report_key(wacom->dev, BTN_TOUCH, button & 1);
354 		input_report_key(wacom->dev, BTN_STYLUS, button & 2);
355 		input_report_key(wacom->dev, BTN_STYLUS2, button & 4);
356 	} else {
357 		input_report_key(wacom->dev, BTN_LEFT, button & 1);
358 		input_report_key(wacom->dev, BTN_RIGHT, button & 2);
359 		input_report_key(wacom->dev, BTN_MIDDLE, button & 4);
360 		/* handle relative wheel for non-stylus device */
361 		z = (wacom->data[6] & 0x30) >> 4;
362 		if (wacom->data[6] & 0x40)
363 			z = -z;
364 		input_report_rel(wacom->dev, REL_WHEEL, z);
365 	}
366 	input_sync(wacom->dev);
367 }
368 
369 static void wacom_clear_data_buf(struct wacom *wacom)
370 {
371 	memset(wacom->data, 0, DATA_SIZE);
372 	wacom->idx = 0;
373 }
374 
375 static irqreturn_t wacom_interrupt(struct serio *serio, unsigned char data,
376 				   unsigned int flags)
377 {
378 	struct wacom *wacom = serio_get_drvdata(serio);
379 
380 	if (data & 0x80)
381 		wacom->idx = 0;
382 
383 	/*
384 	 * We're either expecting a carriage return-terminated ASCII
385 	 * response string, or a seven-byte packet with the MSB set on
386 	 * the first byte.
387 	 *
388 	 * Note however that some tablets (the PenPartner, for
389 	 * example) don't send a carriage return at the end of a
390 	 * command.  We handle these by waiting for timeout.
391 	 */
392 	if (data == '\r' && !(wacom->data[0] & 0x80)) {
393 		wacom_handle_response(wacom);
394 		wacom_clear_data_buf(wacom);
395 		return IRQ_HANDLED;
396 	}
397 
398 	/* Leave place for 0 termination */
399 	if (wacom->idx > (DATA_SIZE - 2)) {
400 		dev_dbg(&wacom->dev->dev,
401 			"throwing away %d bytes of garbage\n", wacom->idx);
402 		wacom_clear_data_buf(wacom);
403 	}
404 	wacom->data[wacom->idx++] = data;
405 
406 	if (wacom->idx == PACKET_LENGTH && (wacom->data[0] & 0x80)) {
407 		wacom_handle_packet(wacom);
408 		wacom_clear_data_buf(wacom);
409 	}
410 
411 	return IRQ_HANDLED;
412 }
413 
414 static void wacom_disconnect(struct serio *serio)
415 {
416 	struct wacom *wacom = serio_get_drvdata(serio);
417 
418 	serio_close(serio);
419 	serio_set_drvdata(serio, NULL);
420 	input_unregister_device(wacom->dev);
421 	kfree(wacom);
422 }
423 
424 static int wacom_send(struct serio *serio, const u8 *command)
425 {
426 	int err = 0;
427 
428 	for (; !err && *command; command++)
429 		err = serio_write(serio, *command);
430 
431 	return err;
432 }
433 
434 static int wacom_send_setup_string(struct wacom *wacom, struct serio *serio)
435 {
436 	const u8 *cmd;
437 
438 	switch (wacom->dev->id.version) {
439 	case MODEL_CINTIQ:	/* UNTESTED */
440 		cmd = COMMAND_ORIGIN_IN_UPPER_LEFT
441 			COMMAND_TRANSMIT_AT_MAX_RATE
442 			COMMAND_ENABLE_CONTINUOUS_MODE
443 			COMMAND_START_SENDING_PACKETS;
444 		break;
445 
446 	case MODEL_PENPARTNER:
447 		cmd = COMMAND_ENABLE_PRESSURE_MODE
448 			COMMAND_START_SENDING_PACKETS;
449 		break;
450 
451 	default:
452 		cmd = COMMAND_MULTI_MODE_INPUT
453 			COMMAND_ORIGIN_IN_UPPER_LEFT
454 			COMMAND_ENABLE_ALL_MACRO_BUTTONS
455 			COMMAND_DISABLE_GROUP_1_MACRO_BUTTONS
456 			COMMAND_TRANSMIT_AT_MAX_RATE
457 			COMMAND_DISABLE_INCREMENTAL_MODE
458 			COMMAND_ENABLE_CONTINUOUS_MODE
459 			COMMAND_Z_FILTER
460 			COMMAND_START_SENDING_PACKETS;
461 		break;
462 	}
463 
464 	return wacom_send(serio, cmd);
465 }
466 
467 static int wacom_send_and_wait(struct wacom *wacom, struct serio *serio,
468 			       const u8 *cmd, const char *desc)
469 {
470 	int err;
471 	unsigned long u;
472 
473 	wacom->expect = cmd[1];
474 	init_completion(&wacom->cmd_done);
475 
476 	err = wacom_send(serio, cmd);
477 	if (err)
478 		return err;
479 
480 	u = wait_for_completion_timeout(&wacom->cmd_done, HZ);
481 	if (u == 0) {
482 		/* Timeout, process what we've received. */
483 		wacom_handle_response(wacom);
484 	}
485 
486 	wacom->expect = 0;
487 	return wacom->result;
488 }
489 
490 static int wacom_setup(struct wacom *wacom, struct serio *serio)
491 {
492 	int err;
493 
494 	/* Note that setting the link speed is the job of inputattach.
495 	 * We assume that reset negotiation has already happened,
496 	 * here. */
497 	err = wacom_send_and_wait(wacom, serio, REQUEST_MODEL_AND_ROM_VERSION,
498 				  "model and version");
499 	if (err)
500 		return err;
501 
502 	if (!(wacom->res_x && wacom->res_y)) {
503 		err = wacom_send_and_wait(wacom, serio,
504 					  REQUEST_CONFIGURATION_STRING,
505 					  "configuration string");
506 		if (err)
507 			return err;
508 	}
509 
510 	if (!(wacom->max_x && wacom->max_y)) {
511 		err = wacom_send_and_wait(wacom, serio,
512 					  REQUEST_MAX_COORDINATES,
513 					  "coordinates string");
514 		if (err)
515 			return err;
516 	}
517 
518 	return wacom_send_setup_string(wacom, serio);
519 }
520 
521 static int wacom_connect(struct serio *serio, struct serio_driver *drv)
522 {
523 	struct wacom *wacom;
524 	struct input_dev *input_dev;
525 	int err = -ENOMEM;
526 
527 	wacom = kzalloc(sizeof(struct wacom), GFP_KERNEL);
528 	input_dev = input_allocate_device();
529 	if (!wacom || !input_dev)
530 		goto free_device;
531 
532 	wacom->dev = input_dev;
533 	wacom->extra_z_bits = 1;
534 	wacom->eraser_mask = 0x04;
535 	wacom->tool = wacom->idx = 0;
536 	snprintf(wacom->phys, sizeof(wacom->phys), "%s/input0", serio->phys);
537 	input_dev->phys = wacom->phys;
538 	input_dev->id.bustype = BUS_RS232;
539 	input_dev->id.vendor  = SERIO_WACOM_IV;
540 	input_dev->id.product = serio->id.extra;
541 	input_dev->dev.parent = &serio->dev;
542 
543 	input_dev->evbit[0] =
544 		BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) | BIT_MASK(EV_REL);
545 	set_bit(ABS_MISC, input_dev->absbit);
546 	set_bit(BTN_TOOL_PEN, input_dev->keybit);
547 	set_bit(BTN_TOOL_RUBBER, input_dev->keybit);
548 	set_bit(BTN_TOOL_MOUSE, input_dev->keybit);
549 	set_bit(BTN_TOUCH, input_dev->keybit);
550 	set_bit(BTN_STYLUS, input_dev->keybit);
551 	set_bit(BTN_LEFT, input_dev->keybit);
552 	set_bit(BTN_RIGHT, input_dev->keybit);
553 	set_bit(BTN_MIDDLE, input_dev->keybit);
554 
555 	serio_set_drvdata(serio, wacom);
556 
557 	err = serio_open(serio, drv);
558 	if (err)
559 		goto free_device;
560 
561 	err = wacom_setup(wacom, serio);
562 	if (err)
563 		goto close_serio;
564 
565 	set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
566 	if (!(wacom->flags & F_COVERS_SCREEN))
567 		__set_bit(INPUT_PROP_POINTER, input_dev->propbit);
568 
569 	if (wacom->flags & F_HAS_STYLUS2)
570 		__set_bit(BTN_STYLUS2, input_dev->keybit);
571 
572 	if (wacom->flags & F_HAS_SCROLLWHEEL)
573 		__set_bit(REL_WHEEL, input_dev->relbit);
574 
575 	input_abs_set_res(wacom->dev, ABS_X, wacom->res_x);
576 	input_abs_set_res(wacom->dev, ABS_Y, wacom->res_y);
577 	input_set_abs_params(wacom->dev, ABS_X, 0, wacom->max_x, 0, 0);
578 	input_set_abs_params(wacom->dev, ABS_Y, 0, wacom->max_y, 0, 0);
579 	input_set_abs_params(wacom->dev, ABS_PRESSURE, -1,
580 			     (1 << (7 + wacom->extra_z_bits)) - 1, 0, 0);
581 
582 	err = input_register_device(wacom->dev);
583 	if (err)
584 		goto close_serio;
585 
586 	return 0;
587 
588 close_serio:
589 	serio_close(serio);
590 free_device:
591 	serio_set_drvdata(serio, NULL);
592 	input_free_device(input_dev);
593 	kfree(wacom);
594 	return err;
595 }
596 
597 static struct serio_device_id wacom_serio_ids[] = {
598 	{
599 		.type	= SERIO_RS232,
600 		.proto	= SERIO_WACOM_IV,
601 		.id	= SERIO_ANY,
602 		.extra	= SERIO_ANY,
603 	},
604 	{ 0 }
605 };
606 
607 MODULE_DEVICE_TABLE(serio, wacom_serio_ids);
608 
609 static struct serio_driver wacom_drv = {
610 	.driver		= {
611 		.name	= "wacom_serial4",
612 	},
613 	.description	= "Wacom protocol 4 serial tablet driver",
614 	.id_table	= wacom_serio_ids,
615 	.interrupt	= wacom_interrupt,
616 	.connect	= wacom_connect,
617 	.disconnect	= wacom_disconnect,
618 };
619 
620 module_serio_driver(wacom_drv);
621