1/*
2 * Driver for	DEC VSXXX-AA mouse (hockey-puck mouse, ball or two rollers)
3 *		DEC VSXXX-GA mouse (rectangular mouse, with ball)
4 *		DEC VSXXX-AB tablet (digitizer with hair cross or stylus)
5 *
6 * Copyright (C) 2003-2004 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
7 *
8 * The packet format was initially taken from a patch to GPM which is (C) 2001
9 * by	Karsten Merker <merker@linuxtag.org>
10 * and	Maciej W. Rozycki <macro@ds2.pg.gda.pl>
11 * Later on, I had access to the device's documentation (referenced below).
12 */
13
14/*
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or
18 * (at your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 */
29
30/*
31 * Building an adaptor to DE9 / DB25 RS232
32 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
33 *
34 * DISCLAIMER: Use this description AT YOUR OWN RISK! I'll not pay for
35 * anything if you break your mouse, your computer or whatever!
36 *
37 * In theory, this mouse is a simple RS232 device. In practice, it has got
38 * a quite uncommon plug and the requirement to additionally get a power
39 * supply at +5V and -12V.
40 *
41 * If you look at the socket/jack (_not_ at the plug), we use this pin
42 * numbering:
43 *    _______
44 *   / 7 6 5 \
45 *  | 4 --- 3 |
46 *   \  2 1  /
47 *    -------
48 *
49 *	DEC socket	DE9	DB25	Note
50 *	1 (GND)		5	7	-
51 *	2 (RxD)		2	3	-
52 *	3 (TxD)		3	2	-
53 *	4 (-12V)	-	-	Somewhere from the PSU. At ATX, it's
54 *					the thin blue wire at pin 12 of the
55 *					ATX power connector. Only required for
56 *					VSXXX-AA/-GA mice.
57 *	5 (+5V)		-	-	PSU (red wires of ATX power connector
58 *					on pin 4, 6, 19 or 20) or HDD power
59 *					connector (also red wire).
60 *	6 (+12V)	-	-	HDD power connector, yellow wire. Only
61 *					required for VSXXX-AB digitizer.
62 *	7 (dev. avail.)	-	-	The mouse shorts this one to pin 1.
63 *					This way, the host computer can detect
64 *					the mouse. To use it with the adaptor,
65 *					simply don't connect this pin.
66 *
67 * So to get a working adaptor, you need to connect the mouse with three
68 * wires to a RS232 port and two or three additional wires for +5V, +12V and
69 * -12V to the PSU.
70 *
71 * Flow specification for the link is 4800, 8o1.
72 *
73 * The mice and tablet are described in "VCB02 Video Subsystem - Technical
74 * Manual", DEC EK-104AA-TM-001. You'll find it at MANX, a search engine
75 * specific for DEC documentation. Try
76 * http://www.vt100.net/manx/details?pn=EK-104AA-TM-001;id=21;cp=1
77 */
78
79#include <linux/delay.h>
80#include <linux/module.h>
81#include <linux/slab.h>
82#include <linux/interrupt.h>
83#include <linux/input.h>
84#include <linux/serio.h>
85
86#define DRIVER_DESC "Driver for DEC VSXXX-AA and -GA mice and VSXXX-AB tablet"
87
88MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
89MODULE_DESCRIPTION(DRIVER_DESC);
90MODULE_LICENSE("GPL");
91
92#undef VSXXXAA_DEBUG
93#ifdef VSXXXAA_DEBUG
94#define DBG(x...) printk(x)
95#else
96#define DBG(x...) do {} while (0)
97#endif
98
99#define VSXXXAA_INTRO_MASK	0x80
100#define VSXXXAA_INTRO_HEAD	0x80
101#define IS_HDR_BYTE(x)			\
102	(((x) & VSXXXAA_INTRO_MASK) == VSXXXAA_INTRO_HEAD)
103
104#define VSXXXAA_PACKET_MASK	0xe0
105#define VSXXXAA_PACKET_REL	0x80
106#define VSXXXAA_PACKET_ABS	0xc0
107#define VSXXXAA_PACKET_POR	0xa0
108#define MATCH_PACKET_TYPE(data, type)	\
109	(((data) & VSXXXAA_PACKET_MASK) == (type))
110
111
112
113struct vsxxxaa {
114	struct input_dev *dev;
115	struct serio *serio;
116#define BUFLEN 15 /* At least 5 is needed for a full tablet packet */
117	unsigned char buf[BUFLEN];
118	unsigned char count;
119	unsigned char version;
120	unsigned char country;
121	unsigned char type;
122	char name[64];
123	char phys[32];
124};
125
126static void vsxxxaa_drop_bytes(struct vsxxxaa *mouse, int num)
127{
128	if (num >= mouse->count) {
129		mouse->count = 0;
130	} else {
131		memmove(mouse->buf, mouse->buf + num, BUFLEN - num);
132		mouse->count -= num;
133	}
134}
135
136static void vsxxxaa_queue_byte(struct vsxxxaa *mouse, unsigned char byte)
137{
138	if (mouse->count == BUFLEN) {
139		printk(KERN_ERR "%s on %s: Dropping a byte of full buffer.\n",
140			mouse->name, mouse->phys);
141		vsxxxaa_drop_bytes(mouse, 1);
142	}
143
144	DBG(KERN_INFO "Queueing byte 0x%02x\n", byte);
145
146	mouse->buf[mouse->count++] = byte;
147}
148
149static void vsxxxaa_detection_done(struct vsxxxaa *mouse)
150{
151	switch (mouse->type) {
152	case 0x02:
153		strlcpy(mouse->name, "DEC VSXXX-AA/-GA mouse",
154			sizeof(mouse->name));
155		break;
156
157	case 0x04:
158		strlcpy(mouse->name, "DEC VSXXX-AB digitizer",
159			sizeof(mouse->name));
160		break;
161
162	default:
163		snprintf(mouse->name, sizeof(mouse->name),
164			 "unknown DEC pointer device (type = 0x%02x)",
165			 mouse->type);
166		break;
167	}
168
169	printk(KERN_INFO
170		"Found %s version 0x%02x from country 0x%02x on port %s\n",
171		mouse->name, mouse->version, mouse->country, mouse->phys);
172}
173
174/*
175 * Returns number of bytes to be dropped, 0 if packet is okay.
176 */
177static int vsxxxaa_check_packet(struct vsxxxaa *mouse, int packet_len)
178{
179	int i;
180
181	/* First byte must be a header byte */
182	if (!IS_HDR_BYTE(mouse->buf[0])) {
183		DBG("vsck: len=%d, 1st=0x%02x\n", packet_len, mouse->buf[0]);
184		return 1;
185	}
186
187	/* Check all following bytes */
188	for (i = 1; i < packet_len; i++) {
189		if (IS_HDR_BYTE(mouse->buf[i])) {
190			printk(KERN_ERR
191				"Need to drop %d bytes of a broken packet.\n",
192				i - 1);
193			DBG(KERN_INFO "check: len=%d, b[%d]=0x%02x\n",
194			    packet_len, i, mouse->buf[i]);
195			return i - 1;
196		}
197	}
198
199	return 0;
200}
201
202static inline int vsxxxaa_smells_like_packet(struct vsxxxaa *mouse,
203					     unsigned char type, size_t len)
204{
205	return mouse->count >= len && MATCH_PACKET_TYPE(mouse->buf[0], type);
206}
207
208static void vsxxxaa_handle_REL_packet(struct vsxxxaa *mouse)
209{
210	struct input_dev *dev = mouse->dev;
211	unsigned char *buf = mouse->buf;
212	int left, middle, right;
213	int dx, dy;
214
215	/*
216	 * Check for normal stream packets. This is three bytes,
217	 * with the first byte's 3 MSB set to 100.
218	 *
219	 * [0]:	1	0	0	SignX	SignY	Left	Middle	Right
220	 * [1]: 0	dx	dx	dx	dx	dx	dx	dx
221	 * [2]:	0	dy	dy	dy	dy	dy	dy	dy
222	 */
223
224	/*
225	 * Low 7 bit of byte 1 are abs(dx), bit 7 is
226	 * 0, bit 4 of byte 0 is direction.
227	 */
228	dx = buf[1] & 0x7f;
229	dx *= ((buf[0] >> 4) & 0x01) ? 1 : -1;
230
231	/*
232	 * Low 7 bit of byte 2 are abs(dy), bit 7 is
233	 * 0, bit 3 of byte 0 is direction.
234	 */
235	dy = buf[2] & 0x7f;
236	dy *= ((buf[0] >> 3) & 0x01) ? -1 : 1;
237
238	/*
239	 * Get button state. It's the low three bits
240	 * (for three buttons) of byte 0.
241	 */
242	left	= buf[0] & 0x04;
243	middle	= buf[0] & 0x02;
244	right	= buf[0] & 0x01;
245
246	vsxxxaa_drop_bytes(mouse, 3);
247
248	DBG(KERN_INFO "%s on %s: dx=%d, dy=%d, buttons=%s%s%s\n",
249	    mouse->name, mouse->phys, dx, dy,
250	    left ? "L" : "l", middle ? "M" : "m", right ? "R" : "r");
251
252	/*
253	 * Report what we've found so far...
254	 */
255	input_report_key(dev, BTN_LEFT, left);
256	input_report_key(dev, BTN_MIDDLE, middle);
257	input_report_key(dev, BTN_RIGHT, right);
258	input_report_key(dev, BTN_TOUCH, 0);
259	input_report_rel(dev, REL_X, dx);
260	input_report_rel(dev, REL_Y, dy);
261	input_sync(dev);
262}
263
264static void vsxxxaa_handle_ABS_packet(struct vsxxxaa *mouse)
265{
266	struct input_dev *dev = mouse->dev;
267	unsigned char *buf = mouse->buf;
268	int left, middle, right, touch;
269	int x, y;
270
271	/*
272	 * Tablet position / button packet
273	 *
274	 * [0]:	1	1	0	B4	B3	B2	B1	Pr
275	 * [1]:	0	0	X5	X4	X3	X2	X1	X0
276	 * [2]:	0	0	X11	X10	X9	X8	X7	X6
277	 * [3]:	0	0	Y5	Y4	Y3	Y2	Y1	Y0
278	 * [4]:	0	0	Y11	Y10	Y9	Y8	Y7	Y6
279	 */
280
281	/*
282	 * Get X/Y position. Y axis needs to be inverted since VSXXX-AB
283	 * counts down->top while monitor counts top->bottom.
284	 */
285	x = ((buf[2] & 0x3f) << 6) | (buf[1] & 0x3f);
286	y = ((buf[4] & 0x3f) << 6) | (buf[3] & 0x3f);
287	y = 1023 - y;
288
289	/*
290	 * Get button state. It's bits <4..1> of byte 0.
291	 */
292	left	= buf[0] & 0x02;
293	middle	= buf[0] & 0x04;
294	right	= buf[0] & 0x08;
295	touch	= buf[0] & 0x10;
296
297	vsxxxaa_drop_bytes(mouse, 5);
298
299	DBG(KERN_INFO "%s on %s: x=%d, y=%d, buttons=%s%s%s%s\n",
300	    mouse->name, mouse->phys, x, y,
301	    left ? "L" : "l", middle ? "M" : "m",
302	    right ? "R" : "r", touch ? "T" : "t");
303
304	/*
305	 * Report what we've found so far...
306	 */
307	input_report_key(dev, BTN_LEFT, left);
308	input_report_key(dev, BTN_MIDDLE, middle);
309	input_report_key(dev, BTN_RIGHT, right);
310	input_report_key(dev, BTN_TOUCH, touch);
311	input_report_abs(dev, ABS_X, x);
312	input_report_abs(dev, ABS_Y, y);
313	input_sync(dev);
314}
315
316static void vsxxxaa_handle_POR_packet(struct vsxxxaa *mouse)
317{
318	struct input_dev *dev = mouse->dev;
319	unsigned char *buf = mouse->buf;
320	int left, middle, right;
321	unsigned char error;
322
323	/*
324	 * Check for Power-On-Reset packets. These are sent out
325	 * after plugging the mouse in, or when explicitly
326	 * requested by sending 'T'.
327	 *
328	 * [0]:	1	0	1	0	R3	R2	R1	R0
329	 * [1]:	0	M2	M1	M0	D3	D2	D1	D0
330	 * [2]:	0	E6	E5	E4	E3	E2	E1	E0
331	 * [3]:	0	0	0	0	0	Left	Middle	Right
332	 *
333	 * M: manufacturer location code
334	 * R: revision code
335	 * E: Error code. If it's in the range of 0x00..0x1f, only some
336	 *    minor problem occurred. Errors >= 0x20 are considered bad
337	 *    and the device may not work properly...
338	 * D: <0010> == mouse, <0100> == tablet
339	 */
340
341	mouse->version = buf[0] & 0x0f;
342	mouse->country = (buf[1] >> 4) & 0x07;
343	mouse->type = buf[1] & 0x0f;
344	error = buf[2] & 0x7f;
345
346	/*
347	 * Get button state. It's the low three bits
348	 * (for three buttons) of byte 0. Maybe even the bit <3>
349	 * has some meaning if a tablet is attached.
350	 */
351	left	= buf[0] & 0x04;
352	middle	= buf[0] & 0x02;
353	right	= buf[0] & 0x01;
354
355	vsxxxaa_drop_bytes(mouse, 4);
356	vsxxxaa_detection_done(mouse);
357
358	if (error <= 0x1f) {
359		/* No (serious) error. Report buttons */
360		input_report_key(dev, BTN_LEFT, left);
361		input_report_key(dev, BTN_MIDDLE, middle);
362		input_report_key(dev, BTN_RIGHT, right);
363		input_report_key(dev, BTN_TOUCH, 0);
364		input_sync(dev);
365
366		if (error != 0)
367			printk(KERN_INFO "Your %s on %s reports error=0x%02x\n",
368				mouse->name, mouse->phys, error);
369
370	}
371
372	/*
373	 * If the mouse was hot-plugged, we need to force differential mode
374	 * now... However, give it a second to recover from it's reset.
375	 */
376	printk(KERN_NOTICE
377		"%s on %s: Forcing standard packet format, "
378		"incremental streaming mode and 72 samples/sec\n",
379		mouse->name, mouse->phys);
380	serio_write(mouse->serio, 'S');	/* Standard format */
381	mdelay(50);
382	serio_write(mouse->serio, 'R');	/* Incremental */
383	mdelay(50);
384	serio_write(mouse->serio, 'L');	/* 72 samples/sec */
385}
386
387static void vsxxxaa_parse_buffer(struct vsxxxaa *mouse)
388{
389	unsigned char *buf = mouse->buf;
390	int stray_bytes;
391
392	/*
393	 * Parse buffer to death...
394	 */
395	do {
396		/*
397		 * Out of sync? Throw away what we don't understand. Each
398		 * packet starts with a byte whose bit 7 is set. Unhandled
399		 * packets (ie. which we don't know about or simply b0rk3d
400		 * data...) will get shifted out of the buffer after some
401		 * activity on the mouse.
402		 */
403		while (mouse->count > 0 && !IS_HDR_BYTE(buf[0])) {
404			printk(KERN_ERR "%s on %s: Dropping a byte to regain "
405				"sync with mouse data stream...\n",
406				mouse->name, mouse->phys);
407			vsxxxaa_drop_bytes(mouse, 1);
408		}
409
410		/*
411		 * Check for packets we know about.
412		 */
413
414		if (vsxxxaa_smells_like_packet(mouse, VSXXXAA_PACKET_REL, 3)) {
415			/* Check for broken packet */
416			stray_bytes = vsxxxaa_check_packet(mouse, 3);
417			if (!stray_bytes)
418				vsxxxaa_handle_REL_packet(mouse);
419
420		} else if (vsxxxaa_smells_like_packet(mouse,
421						      VSXXXAA_PACKET_ABS, 5)) {
422			/* Check for broken packet */
423			stray_bytes = vsxxxaa_check_packet(mouse, 5);
424			if (!stray_bytes)
425				vsxxxaa_handle_ABS_packet(mouse);
426
427		} else if (vsxxxaa_smells_like_packet(mouse,
428						      VSXXXAA_PACKET_POR, 4)) {
429			/* Check for broken packet */
430			stray_bytes = vsxxxaa_check_packet(mouse, 4);
431			if (!stray_bytes)
432				vsxxxaa_handle_POR_packet(mouse);
433
434		} else {
435			break; /* No REL, ABS or POR packet found */
436		}
437
438		if (stray_bytes > 0) {
439			printk(KERN_ERR "Dropping %d bytes now...\n",
440				stray_bytes);
441			vsxxxaa_drop_bytes(mouse, stray_bytes);
442		}
443
444	} while (1);
445}
446
447static irqreturn_t vsxxxaa_interrupt(struct serio *serio,
448				     unsigned char data, unsigned int flags)
449{
450	struct vsxxxaa *mouse = serio_get_drvdata(serio);
451
452	vsxxxaa_queue_byte(mouse, data);
453	vsxxxaa_parse_buffer(mouse);
454
455	return IRQ_HANDLED;
456}
457
458static void vsxxxaa_disconnect(struct serio *serio)
459{
460	struct vsxxxaa *mouse = serio_get_drvdata(serio);
461
462	serio_close(serio);
463	serio_set_drvdata(serio, NULL);
464	input_unregister_device(mouse->dev);
465	kfree(mouse);
466}
467
468static int vsxxxaa_connect(struct serio *serio, struct serio_driver *drv)
469{
470	struct vsxxxaa *mouse;
471	struct input_dev *input_dev;
472	int err = -ENOMEM;
473
474	mouse = kzalloc(sizeof(struct vsxxxaa), GFP_KERNEL);
475	input_dev = input_allocate_device();
476	if (!mouse || !input_dev)
477		goto fail1;
478
479	mouse->dev = input_dev;
480	mouse->serio = serio;
481	strlcat(mouse->name, "DEC VSXXX-AA/-GA mouse or VSXXX-AB digitizer",
482		 sizeof(mouse->name));
483	snprintf(mouse->phys, sizeof(mouse->phys), "%s/input0", serio->phys);
484
485	input_dev->name = mouse->name;
486	input_dev->phys = mouse->phys;
487	input_dev->id.bustype = BUS_RS232;
488	input_dev->dev.parent = &serio->dev;
489
490	__set_bit(EV_KEY, input_dev->evbit);		/* We have buttons */
491	__set_bit(EV_REL, input_dev->evbit);
492	__set_bit(EV_ABS, input_dev->evbit);
493	__set_bit(BTN_LEFT, input_dev->keybit);		/* We have 3 buttons */
494	__set_bit(BTN_MIDDLE, input_dev->keybit);
495	__set_bit(BTN_RIGHT, input_dev->keybit);
496	__set_bit(BTN_TOUCH, input_dev->keybit);	/* ...and Tablet */
497	__set_bit(REL_X, input_dev->relbit);
498	__set_bit(REL_Y, input_dev->relbit);
499	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
500	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
501
502	serio_set_drvdata(serio, mouse);
503
504	err = serio_open(serio, drv);
505	if (err)
506		goto fail2;
507
508	/*
509	 * Request selftest. Standard packet format and differential
510	 * mode will be requested after the device ID'ed successfully.
511	 */
512	serio_write(serio, 'T'); /* Test */
513
514	err = input_register_device(input_dev);
515	if (err)
516		goto fail3;
517
518	return 0;
519
520 fail3:	serio_close(serio);
521 fail2:	serio_set_drvdata(serio, NULL);
522 fail1:	input_free_device(input_dev);
523	kfree(mouse);
524	return err;
525}
526
527static struct serio_device_id vsxxaa_serio_ids[] = {
528	{
529		.type	= SERIO_RS232,
530		.proto	= SERIO_VSXXXAA,
531		.id	= SERIO_ANY,
532		.extra	= SERIO_ANY,
533	},
534	{ 0 }
535};
536
537MODULE_DEVICE_TABLE(serio, vsxxaa_serio_ids);
538
539static struct serio_driver vsxxxaa_drv = {
540	.driver		= {
541		.name	= "vsxxxaa",
542	},
543	.description	= DRIVER_DESC,
544	.id_table	= vsxxaa_serio_ids,
545	.connect	= vsxxxaa_connect,
546	.interrupt	= vsxxxaa_interrupt,
547	.disconnect	= vsxxxaa_disconnect,
548};
549
550module_serio_driver(vsxxxaa_drv);
551