1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for	DEC VSXXX-AA mouse (hockey-puck mouse, ball or two rollers)
4  *		DEC VSXXX-GA mouse (rectangular mouse, with ball)
5  *		DEC VSXXX-AB tablet (digitizer with hair cross or stylus)
6  *
7  * Copyright (C) 2003-2004 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
8  *
9  * The packet format was initially taken from a patch to GPM which is (C) 2001
10  * by	Karsten Merker <merker@linuxtag.org>
11  * and	Maciej W. Rozycki <macro@ds2.pg.gda.pl>
12  * Later on, I had access to the device's documentation (referenced below).
13  */
14 
15 /*
16  */
17 
18 /*
19  * Building an adaptor to DE9 / DB25 RS232
20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21  *
22  * DISCLAIMER: Use this description AT YOUR OWN RISK! I'll not pay for
23  * anything if you break your mouse, your computer or whatever!
24  *
25  * In theory, this mouse is a simple RS232 device. In practice, it has got
26  * a quite uncommon plug and the requirement to additionally get a power
27  * supply at +5V and -12V.
28  *
29  * If you look at the socket/jack (_not_ at the plug), we use this pin
30  * numbering:
31  *    _______
32  *   / 7 6 5 \
33  *  | 4 --- 3 |
34  *   \  2 1  /
35  *    -------
36  *
37  *	DEC socket	DE9	DB25	Note
38  *	1 (GND)		5	7	-
39  *	2 (RxD)		2	3	-
40  *	3 (TxD)		3	2	-
41  *	4 (-12V)	-	-	Somewhere from the PSU. At ATX, it's
42  *					the thin blue wire at pin 12 of the
43  *					ATX power connector. Only required for
44  *					VSXXX-AA/-GA mice.
45  *	5 (+5V)		-	-	PSU (red wires of ATX power connector
46  *					on pin 4, 6, 19 or 20) or HDD power
47  *					connector (also red wire).
48  *	6 (+12V)	-	-	HDD power connector, yellow wire. Only
49  *					required for VSXXX-AB digitizer.
50  *	7 (dev. avail.)	-	-	The mouse shorts this one to pin 1.
51  *					This way, the host computer can detect
52  *					the mouse. To use it with the adaptor,
53  *					simply don't connect this pin.
54  *
55  * So to get a working adaptor, you need to connect the mouse with three
56  * wires to a RS232 port and two or three additional wires for +5V, +12V and
57  * -12V to the PSU.
58  *
59  * Flow specification for the link is 4800, 8o1.
60  *
61  * The mice and tablet are described in "VCB02 Video Subsystem - Technical
62  * Manual", DEC EK-104AA-TM-001. You'll find it at MANX, a search engine
63  * specific for DEC documentation. Try
64  * http://www.vt100.net/manx/details?pn=EK-104AA-TM-001;id=21;cp=1
65  */
66 
67 #include <linux/delay.h>
68 #include <linux/module.h>
69 #include <linux/slab.h>
70 #include <linux/interrupt.h>
71 #include <linux/input.h>
72 #include <linux/serio.h>
73 
74 #define DRIVER_DESC "Driver for DEC VSXXX-AA and -GA mice and VSXXX-AB tablet"
75 
76 MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
77 MODULE_DESCRIPTION(DRIVER_DESC);
78 MODULE_LICENSE("GPL");
79 
80 #undef VSXXXAA_DEBUG
81 #ifdef VSXXXAA_DEBUG
82 #define DBG(x...) printk(x)
83 #else
84 #define DBG(x...) do {} while (0)
85 #endif
86 
87 #define VSXXXAA_INTRO_MASK	0x80
88 #define VSXXXAA_INTRO_HEAD	0x80
89 #define IS_HDR_BYTE(x)			\
90 	(((x) & VSXXXAA_INTRO_MASK) == VSXXXAA_INTRO_HEAD)
91 
92 #define VSXXXAA_PACKET_MASK	0xe0
93 #define VSXXXAA_PACKET_REL	0x80
94 #define VSXXXAA_PACKET_ABS	0xc0
95 #define VSXXXAA_PACKET_POR	0xa0
96 #define MATCH_PACKET_TYPE(data, type)	\
97 	(((data) & VSXXXAA_PACKET_MASK) == (type))
98 
99 
100 
101 struct vsxxxaa {
102 	struct input_dev *dev;
103 	struct serio *serio;
104 #define BUFLEN 15 /* At least 5 is needed for a full tablet packet */
105 	unsigned char buf[BUFLEN];
106 	unsigned char count;
107 	unsigned char version;
108 	unsigned char country;
109 	unsigned char type;
110 	char name[64];
111 	char phys[32];
112 };
113 
vsxxxaa_drop_bytes(struct vsxxxaa * mouse,int num)114 static void vsxxxaa_drop_bytes(struct vsxxxaa *mouse, int num)
115 {
116 	if (num >= mouse->count) {
117 		mouse->count = 0;
118 	} else {
119 		memmove(mouse->buf, mouse->buf + num, BUFLEN - num);
120 		mouse->count -= num;
121 	}
122 }
123 
vsxxxaa_queue_byte(struct vsxxxaa * mouse,unsigned char byte)124 static void vsxxxaa_queue_byte(struct vsxxxaa *mouse, unsigned char byte)
125 {
126 	if (mouse->count == BUFLEN) {
127 		printk(KERN_ERR "%s on %s: Dropping a byte of full buffer.\n",
128 			mouse->name, mouse->phys);
129 		vsxxxaa_drop_bytes(mouse, 1);
130 	}
131 
132 	DBG(KERN_INFO "Queueing byte 0x%02x\n", byte);
133 
134 	mouse->buf[mouse->count++] = byte;
135 }
136 
vsxxxaa_detection_done(struct vsxxxaa * mouse)137 static void vsxxxaa_detection_done(struct vsxxxaa *mouse)
138 {
139 	switch (mouse->type) {
140 	case 0x02:
141 		strlcpy(mouse->name, "DEC VSXXX-AA/-GA mouse",
142 			sizeof(mouse->name));
143 		break;
144 
145 	case 0x04:
146 		strlcpy(mouse->name, "DEC VSXXX-AB digitizer",
147 			sizeof(mouse->name));
148 		break;
149 
150 	default:
151 		snprintf(mouse->name, sizeof(mouse->name),
152 			 "unknown DEC pointer device (type = 0x%02x)",
153 			 mouse->type);
154 		break;
155 	}
156 
157 	printk(KERN_INFO
158 		"Found %s version 0x%02x from country 0x%02x on port %s\n",
159 		mouse->name, mouse->version, mouse->country, mouse->phys);
160 }
161 
162 /*
163  * Returns number of bytes to be dropped, 0 if packet is okay.
164  */
vsxxxaa_check_packet(struct vsxxxaa * mouse,int packet_len)165 static int vsxxxaa_check_packet(struct vsxxxaa *mouse, int packet_len)
166 {
167 	int i;
168 
169 	/* First byte must be a header byte */
170 	if (!IS_HDR_BYTE(mouse->buf[0])) {
171 		DBG("vsck: len=%d, 1st=0x%02x\n", packet_len, mouse->buf[0]);
172 		return 1;
173 	}
174 
175 	/* Check all following bytes */
176 	for (i = 1; i < packet_len; i++) {
177 		if (IS_HDR_BYTE(mouse->buf[i])) {
178 			printk(KERN_ERR
179 				"Need to drop %d bytes of a broken packet.\n",
180 				i - 1);
181 			DBG(KERN_INFO "check: len=%d, b[%d]=0x%02x\n",
182 			    packet_len, i, mouse->buf[i]);
183 			return i - 1;
184 		}
185 	}
186 
187 	return 0;
188 }
189 
vsxxxaa_smells_like_packet(struct vsxxxaa * mouse,unsigned char type,size_t len)190 static inline int vsxxxaa_smells_like_packet(struct vsxxxaa *mouse,
191 					     unsigned char type, size_t len)
192 {
193 	return mouse->count >= len && MATCH_PACKET_TYPE(mouse->buf[0], type);
194 }
195 
vsxxxaa_handle_REL_packet(struct vsxxxaa * mouse)196 static void vsxxxaa_handle_REL_packet(struct vsxxxaa *mouse)
197 {
198 	struct input_dev *dev = mouse->dev;
199 	unsigned char *buf = mouse->buf;
200 	int left, middle, right;
201 	int dx, dy;
202 
203 	/*
204 	 * Check for normal stream packets. This is three bytes,
205 	 * with the first byte's 3 MSB set to 100.
206 	 *
207 	 * [0]:	1	0	0	SignX	SignY	Left	Middle	Right
208 	 * [1]: 0	dx	dx	dx	dx	dx	dx	dx
209 	 * [2]:	0	dy	dy	dy	dy	dy	dy	dy
210 	 */
211 
212 	/*
213 	 * Low 7 bit of byte 1 are abs(dx), bit 7 is
214 	 * 0, bit 4 of byte 0 is direction.
215 	 */
216 	dx = buf[1] & 0x7f;
217 	dx *= ((buf[0] >> 4) & 0x01) ? 1 : -1;
218 
219 	/*
220 	 * Low 7 bit of byte 2 are abs(dy), bit 7 is
221 	 * 0, bit 3 of byte 0 is direction.
222 	 */
223 	dy = buf[2] & 0x7f;
224 	dy *= ((buf[0] >> 3) & 0x01) ? -1 : 1;
225 
226 	/*
227 	 * Get button state. It's the low three bits
228 	 * (for three buttons) of byte 0.
229 	 */
230 	left	= buf[0] & 0x04;
231 	middle	= buf[0] & 0x02;
232 	right	= buf[0] & 0x01;
233 
234 	vsxxxaa_drop_bytes(mouse, 3);
235 
236 	DBG(KERN_INFO "%s on %s: dx=%d, dy=%d, buttons=%s%s%s\n",
237 	    mouse->name, mouse->phys, dx, dy,
238 	    left ? "L" : "l", middle ? "M" : "m", right ? "R" : "r");
239 
240 	/*
241 	 * Report what we've found so far...
242 	 */
243 	input_report_key(dev, BTN_LEFT, left);
244 	input_report_key(dev, BTN_MIDDLE, middle);
245 	input_report_key(dev, BTN_RIGHT, right);
246 	input_report_key(dev, BTN_TOUCH, 0);
247 	input_report_rel(dev, REL_X, dx);
248 	input_report_rel(dev, REL_Y, dy);
249 	input_sync(dev);
250 }
251 
vsxxxaa_handle_ABS_packet(struct vsxxxaa * mouse)252 static void vsxxxaa_handle_ABS_packet(struct vsxxxaa *mouse)
253 {
254 	struct input_dev *dev = mouse->dev;
255 	unsigned char *buf = mouse->buf;
256 	int left, middle, right, touch;
257 	int x, y;
258 
259 	/*
260 	 * Tablet position / button packet
261 	 *
262 	 * [0]:	1	1	0	B4	B3	B2	B1	Pr
263 	 * [1]:	0	0	X5	X4	X3	X2	X1	X0
264 	 * [2]:	0	0	X11	X10	X9	X8	X7	X6
265 	 * [3]:	0	0	Y5	Y4	Y3	Y2	Y1	Y0
266 	 * [4]:	0	0	Y11	Y10	Y9	Y8	Y7	Y6
267 	 */
268 
269 	/*
270 	 * Get X/Y position. Y axis needs to be inverted since VSXXX-AB
271 	 * counts down->top while monitor counts top->bottom.
272 	 */
273 	x = ((buf[2] & 0x3f) << 6) | (buf[1] & 0x3f);
274 	y = ((buf[4] & 0x3f) << 6) | (buf[3] & 0x3f);
275 	y = 1023 - y;
276 
277 	/*
278 	 * Get button state. It's bits <4..1> of byte 0.
279 	 */
280 	left	= buf[0] & 0x02;
281 	middle	= buf[0] & 0x04;
282 	right	= buf[0] & 0x08;
283 	touch	= buf[0] & 0x10;
284 
285 	vsxxxaa_drop_bytes(mouse, 5);
286 
287 	DBG(KERN_INFO "%s on %s: x=%d, y=%d, buttons=%s%s%s%s\n",
288 	    mouse->name, mouse->phys, x, y,
289 	    left ? "L" : "l", middle ? "M" : "m",
290 	    right ? "R" : "r", touch ? "T" : "t");
291 
292 	/*
293 	 * Report what we've found so far...
294 	 */
295 	input_report_key(dev, BTN_LEFT, left);
296 	input_report_key(dev, BTN_MIDDLE, middle);
297 	input_report_key(dev, BTN_RIGHT, right);
298 	input_report_key(dev, BTN_TOUCH, touch);
299 	input_report_abs(dev, ABS_X, x);
300 	input_report_abs(dev, ABS_Y, y);
301 	input_sync(dev);
302 }
303 
vsxxxaa_handle_POR_packet(struct vsxxxaa * mouse)304 static void vsxxxaa_handle_POR_packet(struct vsxxxaa *mouse)
305 {
306 	struct input_dev *dev = mouse->dev;
307 	unsigned char *buf = mouse->buf;
308 	int left, middle, right;
309 	unsigned char error;
310 
311 	/*
312 	 * Check for Power-On-Reset packets. These are sent out
313 	 * after plugging the mouse in, or when explicitly
314 	 * requested by sending 'T'.
315 	 *
316 	 * [0]:	1	0	1	0	R3	R2	R1	R0
317 	 * [1]:	0	M2	M1	M0	D3	D2	D1	D0
318 	 * [2]:	0	E6	E5	E4	E3	E2	E1	E0
319 	 * [3]:	0	0	0	0	0	Left	Middle	Right
320 	 *
321 	 * M: manufacturer location code
322 	 * R: revision code
323 	 * E: Error code. If it's in the range of 0x00..0x1f, only some
324 	 *    minor problem occurred. Errors >= 0x20 are considered bad
325 	 *    and the device may not work properly...
326 	 * D: <0010> == mouse, <0100> == tablet
327 	 */
328 
329 	mouse->version = buf[0] & 0x0f;
330 	mouse->country = (buf[1] >> 4) & 0x07;
331 	mouse->type = buf[1] & 0x0f;
332 	error = buf[2] & 0x7f;
333 
334 	/*
335 	 * Get button state. It's the low three bits
336 	 * (for three buttons) of byte 0. Maybe even the bit <3>
337 	 * has some meaning if a tablet is attached.
338 	 */
339 	left	= buf[0] & 0x04;
340 	middle	= buf[0] & 0x02;
341 	right	= buf[0] & 0x01;
342 
343 	vsxxxaa_drop_bytes(mouse, 4);
344 	vsxxxaa_detection_done(mouse);
345 
346 	if (error <= 0x1f) {
347 		/* No (serious) error. Report buttons */
348 		input_report_key(dev, BTN_LEFT, left);
349 		input_report_key(dev, BTN_MIDDLE, middle);
350 		input_report_key(dev, BTN_RIGHT, right);
351 		input_report_key(dev, BTN_TOUCH, 0);
352 		input_sync(dev);
353 
354 		if (error != 0)
355 			printk(KERN_INFO "Your %s on %s reports error=0x%02x\n",
356 				mouse->name, mouse->phys, error);
357 
358 	}
359 
360 	/*
361 	 * If the mouse was hot-plugged, we need to force differential mode
362 	 * now... However, give it a second to recover from it's reset.
363 	 */
364 	printk(KERN_NOTICE
365 		"%s on %s: Forcing standard packet format, "
366 		"incremental streaming mode and 72 samples/sec\n",
367 		mouse->name, mouse->phys);
368 	serio_write(mouse->serio, 'S');	/* Standard format */
369 	mdelay(50);
370 	serio_write(mouse->serio, 'R');	/* Incremental */
371 	mdelay(50);
372 	serio_write(mouse->serio, 'L');	/* 72 samples/sec */
373 }
374 
vsxxxaa_parse_buffer(struct vsxxxaa * mouse)375 static void vsxxxaa_parse_buffer(struct vsxxxaa *mouse)
376 {
377 	unsigned char *buf = mouse->buf;
378 	int stray_bytes;
379 
380 	/*
381 	 * Parse buffer to death...
382 	 */
383 	do {
384 		/*
385 		 * Out of sync? Throw away what we don't understand. Each
386 		 * packet starts with a byte whose bit 7 is set. Unhandled
387 		 * packets (ie. which we don't know about or simply b0rk3d
388 		 * data...) will get shifted out of the buffer after some
389 		 * activity on the mouse.
390 		 */
391 		while (mouse->count > 0 && !IS_HDR_BYTE(buf[0])) {
392 			printk(KERN_ERR "%s on %s: Dropping a byte to regain "
393 				"sync with mouse data stream...\n",
394 				mouse->name, mouse->phys);
395 			vsxxxaa_drop_bytes(mouse, 1);
396 		}
397 
398 		/*
399 		 * Check for packets we know about.
400 		 */
401 
402 		if (vsxxxaa_smells_like_packet(mouse, VSXXXAA_PACKET_REL, 3)) {
403 			/* Check for broken packet */
404 			stray_bytes = vsxxxaa_check_packet(mouse, 3);
405 			if (!stray_bytes)
406 				vsxxxaa_handle_REL_packet(mouse);
407 
408 		} else if (vsxxxaa_smells_like_packet(mouse,
409 						      VSXXXAA_PACKET_ABS, 5)) {
410 			/* Check for broken packet */
411 			stray_bytes = vsxxxaa_check_packet(mouse, 5);
412 			if (!stray_bytes)
413 				vsxxxaa_handle_ABS_packet(mouse);
414 
415 		} else if (vsxxxaa_smells_like_packet(mouse,
416 						      VSXXXAA_PACKET_POR, 4)) {
417 			/* Check for broken packet */
418 			stray_bytes = vsxxxaa_check_packet(mouse, 4);
419 			if (!stray_bytes)
420 				vsxxxaa_handle_POR_packet(mouse);
421 
422 		} else {
423 			break; /* No REL, ABS or POR packet found */
424 		}
425 
426 		if (stray_bytes > 0) {
427 			printk(KERN_ERR "Dropping %d bytes now...\n",
428 				stray_bytes);
429 			vsxxxaa_drop_bytes(mouse, stray_bytes);
430 		}
431 
432 	} while (1);
433 }
434 
vsxxxaa_interrupt(struct serio * serio,unsigned char data,unsigned int flags)435 static irqreturn_t vsxxxaa_interrupt(struct serio *serio,
436 				     unsigned char data, unsigned int flags)
437 {
438 	struct vsxxxaa *mouse = serio_get_drvdata(serio);
439 
440 	vsxxxaa_queue_byte(mouse, data);
441 	vsxxxaa_parse_buffer(mouse);
442 
443 	return IRQ_HANDLED;
444 }
445 
vsxxxaa_disconnect(struct serio * serio)446 static void vsxxxaa_disconnect(struct serio *serio)
447 {
448 	struct vsxxxaa *mouse = serio_get_drvdata(serio);
449 
450 	serio_close(serio);
451 	serio_set_drvdata(serio, NULL);
452 	input_unregister_device(mouse->dev);
453 	kfree(mouse);
454 }
455 
vsxxxaa_connect(struct serio * serio,struct serio_driver * drv)456 static int vsxxxaa_connect(struct serio *serio, struct serio_driver *drv)
457 {
458 	struct vsxxxaa *mouse;
459 	struct input_dev *input_dev;
460 	int err = -ENOMEM;
461 
462 	mouse = kzalloc(sizeof(struct vsxxxaa), GFP_KERNEL);
463 	input_dev = input_allocate_device();
464 	if (!mouse || !input_dev)
465 		goto fail1;
466 
467 	mouse->dev = input_dev;
468 	mouse->serio = serio;
469 	strlcat(mouse->name, "DEC VSXXX-AA/-GA mouse or VSXXX-AB digitizer",
470 		 sizeof(mouse->name));
471 	snprintf(mouse->phys, sizeof(mouse->phys), "%s/input0", serio->phys);
472 
473 	input_dev->name = mouse->name;
474 	input_dev->phys = mouse->phys;
475 	input_dev->id.bustype = BUS_RS232;
476 	input_dev->dev.parent = &serio->dev;
477 
478 	__set_bit(EV_KEY, input_dev->evbit);		/* We have buttons */
479 	__set_bit(EV_REL, input_dev->evbit);
480 	__set_bit(EV_ABS, input_dev->evbit);
481 	__set_bit(BTN_LEFT, input_dev->keybit);		/* We have 3 buttons */
482 	__set_bit(BTN_MIDDLE, input_dev->keybit);
483 	__set_bit(BTN_RIGHT, input_dev->keybit);
484 	__set_bit(BTN_TOUCH, input_dev->keybit);	/* ...and Tablet */
485 	__set_bit(REL_X, input_dev->relbit);
486 	__set_bit(REL_Y, input_dev->relbit);
487 	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
488 	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
489 
490 	serio_set_drvdata(serio, mouse);
491 
492 	err = serio_open(serio, drv);
493 	if (err)
494 		goto fail2;
495 
496 	/*
497 	 * Request selftest. Standard packet format and differential
498 	 * mode will be requested after the device ID'ed successfully.
499 	 */
500 	serio_write(serio, 'T'); /* Test */
501 
502 	err = input_register_device(input_dev);
503 	if (err)
504 		goto fail3;
505 
506 	return 0;
507 
508  fail3:	serio_close(serio);
509  fail2:	serio_set_drvdata(serio, NULL);
510  fail1:	input_free_device(input_dev);
511 	kfree(mouse);
512 	return err;
513 }
514 
515 static struct serio_device_id vsxxaa_serio_ids[] = {
516 	{
517 		.type	= SERIO_RS232,
518 		.proto	= SERIO_VSXXXAA,
519 		.id	= SERIO_ANY,
520 		.extra	= SERIO_ANY,
521 	},
522 	{ 0 }
523 };
524 
525 MODULE_DEVICE_TABLE(serio, vsxxaa_serio_ids);
526 
527 static struct serio_driver vsxxxaa_drv = {
528 	.driver		= {
529 		.name	= "vsxxxaa",
530 	},
531 	.description	= DRIVER_DESC,
532 	.id_table	= vsxxaa_serio_ids,
533 	.connect	= vsxxxaa_connect,
534 	.interrupt	= vsxxxaa_interrupt,
535 	.disconnect	= vsxxxaa_disconnect,
536 };
537 
538 module_serio_driver(vsxxxaa_drv);
539