xref: /linux/drivers/input/mouse/vsxxxaa.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
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  * Building an adaptor to DE9 / DB25 RS232
17  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
18  *
19  * DISCLAIMER: Use this description AT YOUR OWN RISK! I'll not pay for
20  * anything if you break your mouse, your computer or whatever!
21  *
22  * In theory, this mouse is a simple RS232 device. In practice, it has got
23  * a quite uncommon plug and the requirement to additionally get a power
24  * supply at +5V and -12V.
25  *
26  * If you look at the socket/jack (_not_ at the plug), we use this pin
27  * numbering:
28  *    _______
29  *   / 7 6 5 \
30  *  | 4 --- 3 |
31  *   \  2 1  /
32  *    -------
33  *
34  *	DEC socket	DE9	DB25	Note
35  *	1 (GND)		5	7	-
36  *	2 (RxD)		2	3	-
37  *	3 (TxD)		3	2	-
38  *	4 (-12V)	-	-	Somewhere from the PSU. At ATX, it's
39  *					the thin blue wire at pin 12 of the
40  *					ATX power connector. Only required for
41  *					VSXXX-AA/-GA mice.
42  *	5 (+5V)		-	-	PSU (red wires of ATX power connector
43  *					on pin 4, 6, 19 or 20) or HDD power
44  *					connector (also red wire).
45  *	6 (+12V)	-	-	HDD power connector, yellow wire. Only
46  *					required for VSXXX-AB digitizer.
47  *	7 (dev. avail.)	-	-	The mouse shorts this one to pin 1.
48  *					This way, the host computer can detect
49  *					the mouse. To use it with the adaptor,
50  *					simply don't connect this pin.
51  *
52  * So to get a working adaptor, you need to connect the mouse with three
53  * wires to a RS232 port and two or three additional wires for +5V, +12V and
54  * -12V to the PSU.
55  *
56  * Flow specification for the link is 4800, 8o1.
57  *
58  * The mice and tablet are described in "VCB02 Video Subsystem - Technical
59  * Manual", DEC EK-104AA-TM-001. You'll find it at MANX, a search engine
60  * specific for DEC documentation. Try
61  * http://www.vt100.net/manx/details?pn=EK-104AA-TM-001;id=21;cp=1
62  */
63 
64 #include <linux/delay.h>
65 #include <linux/module.h>
66 #include <linux/slab.h>
67 #include <linux/interrupt.h>
68 #include <linux/input.h>
69 #include <linux/serio.h>
70 
71 #define DRIVER_DESC "Driver for DEC VSXXX-AA and -GA mice and VSXXX-AB tablet"
72 
73 MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
74 MODULE_DESCRIPTION(DRIVER_DESC);
75 MODULE_LICENSE("GPL");
76 
77 #undef VSXXXAA_DEBUG
78 #ifdef VSXXXAA_DEBUG
79 #define DBG(x...) printk(x)
80 #else
81 #define DBG(x...) do {} while (0)
82 #endif
83 
84 #define VSXXXAA_INTRO_MASK	0x80
85 #define VSXXXAA_INTRO_HEAD	0x80
86 #define IS_HDR_BYTE(x)			\
87 	(((x) & VSXXXAA_INTRO_MASK) == VSXXXAA_INTRO_HEAD)
88 
89 #define VSXXXAA_PACKET_MASK	0xe0
90 #define VSXXXAA_PACKET_REL	0x80
91 #define VSXXXAA_PACKET_ABS	0xc0
92 #define VSXXXAA_PACKET_POR	0xa0
93 #define MATCH_PACKET_TYPE(data, type)	\
94 	(((data) & VSXXXAA_PACKET_MASK) == (type))
95 
96 
97 
98 struct vsxxxaa {
99 	struct input_dev *dev;
100 	struct serio *serio;
101 #define BUFLEN 15 /* At least 5 is needed for a full tablet packet */
102 	unsigned char buf[BUFLEN];
103 	unsigned char count;
104 	unsigned char version;
105 	unsigned char country;
106 	unsigned char type;
107 	char name[64];
108 	char phys[32];
109 };
110 
111 static void vsxxxaa_drop_bytes(struct vsxxxaa *mouse, int num)
112 {
113 	if (num >= mouse->count) {
114 		mouse->count = 0;
115 	} else {
116 		memmove(mouse->buf, mouse->buf + num, BUFLEN - num);
117 		mouse->count -= num;
118 	}
119 }
120 
121 static void vsxxxaa_queue_byte(struct vsxxxaa *mouse, unsigned char byte)
122 {
123 	if (mouse->count == BUFLEN) {
124 		printk(KERN_ERR "%s on %s: Dropping a byte of full buffer.\n",
125 			mouse->name, mouse->phys);
126 		vsxxxaa_drop_bytes(mouse, 1);
127 	}
128 
129 	DBG(KERN_INFO "Queueing byte 0x%02x\n", byte);
130 
131 	mouse->buf[mouse->count++] = byte;
132 }
133 
134 static void vsxxxaa_detection_done(struct vsxxxaa *mouse)
135 {
136 	switch (mouse->type) {
137 	case 0x02:
138 		strscpy(mouse->name, "DEC VSXXX-AA/-GA mouse",
139 			sizeof(mouse->name));
140 		break;
141 
142 	case 0x04:
143 		strscpy(mouse->name, "DEC VSXXX-AB digitizer",
144 			sizeof(mouse->name));
145 		break;
146 
147 	default:
148 		snprintf(mouse->name, sizeof(mouse->name),
149 			 "unknown DEC pointer device (type = 0x%02x)",
150 			 mouse->type);
151 		break;
152 	}
153 
154 	printk(KERN_INFO
155 		"Found %s version 0x%02x from country 0x%02x on port %s\n",
156 		mouse->name, mouse->version, mouse->country, mouse->phys);
157 }
158 
159 /*
160  * Returns number of bytes to be dropped, 0 if packet is okay.
161  */
162 static int vsxxxaa_check_packet(struct vsxxxaa *mouse, int packet_len)
163 {
164 	int i;
165 
166 	/* First byte must be a header byte */
167 	if (!IS_HDR_BYTE(mouse->buf[0])) {
168 		DBG("vsck: len=%d, 1st=0x%02x\n", packet_len, mouse->buf[0]);
169 		return 1;
170 	}
171 
172 	/* Check all following bytes */
173 	for (i = 1; i < packet_len; i++) {
174 		if (IS_HDR_BYTE(mouse->buf[i])) {
175 			printk(KERN_ERR
176 				"Need to drop %d bytes of a broken packet.\n",
177 				i - 1);
178 			DBG(KERN_INFO "check: len=%d, b[%d]=0x%02x\n",
179 			    packet_len, i, mouse->buf[i]);
180 			return i - 1;
181 		}
182 	}
183 
184 	return 0;
185 }
186 
187 static inline int vsxxxaa_smells_like_packet(struct vsxxxaa *mouse,
188 					     unsigned char type, size_t len)
189 {
190 	return mouse->count >= len && MATCH_PACKET_TYPE(mouse->buf[0], type);
191 }
192 
193 static void vsxxxaa_handle_REL_packet(struct vsxxxaa *mouse)
194 {
195 	struct input_dev *dev = mouse->dev;
196 	unsigned char *buf = mouse->buf;
197 	int left, middle, right;
198 	int dx, dy;
199 
200 	/*
201 	 * Check for normal stream packets. This is three bytes,
202 	 * with the first byte's 3 MSB set to 100.
203 	 *
204 	 * [0]:	1	0	0	SignX	SignY	Left	Middle	Right
205 	 * [1]: 0	dx	dx	dx	dx	dx	dx	dx
206 	 * [2]:	0	dy	dy	dy	dy	dy	dy	dy
207 	 */
208 
209 	/*
210 	 * Low 7 bit of byte 1 are abs(dx), bit 7 is
211 	 * 0, bit 4 of byte 0 is direction.
212 	 */
213 	dx = buf[1] & 0x7f;
214 	dx *= ((buf[0] >> 4) & 0x01) ? 1 : -1;
215 
216 	/*
217 	 * Low 7 bit of byte 2 are abs(dy), bit 7 is
218 	 * 0, bit 3 of byte 0 is direction.
219 	 */
220 	dy = buf[2] & 0x7f;
221 	dy *= ((buf[0] >> 3) & 0x01) ? -1 : 1;
222 
223 	/*
224 	 * Get button state. It's the low three bits
225 	 * (for three buttons) of byte 0.
226 	 */
227 	left	= buf[0] & 0x04;
228 	middle	= buf[0] & 0x02;
229 	right	= buf[0] & 0x01;
230 
231 	vsxxxaa_drop_bytes(mouse, 3);
232 
233 	DBG(KERN_INFO "%s on %s: dx=%d, dy=%d, buttons=%s%s%s\n",
234 	    mouse->name, mouse->phys, dx, dy,
235 	    left ? "L" : "l", middle ? "M" : "m", right ? "R" : "r");
236 
237 	/*
238 	 * Report what we've found so far...
239 	 */
240 	input_report_key(dev, BTN_LEFT, left);
241 	input_report_key(dev, BTN_MIDDLE, middle);
242 	input_report_key(dev, BTN_RIGHT, right);
243 	input_report_key(dev, BTN_TOUCH, 0);
244 	input_report_rel(dev, REL_X, dx);
245 	input_report_rel(dev, REL_Y, dy);
246 	input_sync(dev);
247 }
248 
249 static void vsxxxaa_handle_ABS_packet(struct vsxxxaa *mouse)
250 {
251 	struct input_dev *dev = mouse->dev;
252 	unsigned char *buf = mouse->buf;
253 	int left, middle, right, touch;
254 	int x, y;
255 
256 	/*
257 	 * Tablet position / button packet
258 	 *
259 	 * [0]:	1	1	0	B4	B3	B2	B1	Pr
260 	 * [1]:	0	0	X5	X4	X3	X2	X1	X0
261 	 * [2]:	0	0	X11	X10	X9	X8	X7	X6
262 	 * [3]:	0	0	Y5	Y4	Y3	Y2	Y1	Y0
263 	 * [4]:	0	0	Y11	Y10	Y9	Y8	Y7	Y6
264 	 */
265 
266 	/*
267 	 * Get X/Y position. Y axis needs to be inverted since VSXXX-AB
268 	 * counts down->top while monitor counts top->bottom.
269 	 */
270 	x = ((buf[2] & 0x3f) << 6) | (buf[1] & 0x3f);
271 	y = ((buf[4] & 0x3f) << 6) | (buf[3] & 0x3f);
272 	y = 1023 - y;
273 
274 	/*
275 	 * Get button state. It's bits <4..1> of byte 0.
276 	 */
277 	left	= buf[0] & 0x02;
278 	middle	= buf[0] & 0x04;
279 	right	= buf[0] & 0x08;
280 	touch	= buf[0] & 0x10;
281 
282 	vsxxxaa_drop_bytes(mouse, 5);
283 
284 	DBG(KERN_INFO "%s on %s: x=%d, y=%d, buttons=%s%s%s%s\n",
285 	    mouse->name, mouse->phys, x, y,
286 	    left ? "L" : "l", middle ? "M" : "m",
287 	    right ? "R" : "r", touch ? "T" : "t");
288 
289 	/*
290 	 * Report what we've found so far...
291 	 */
292 	input_report_key(dev, BTN_LEFT, left);
293 	input_report_key(dev, BTN_MIDDLE, middle);
294 	input_report_key(dev, BTN_RIGHT, right);
295 	input_report_key(dev, BTN_TOUCH, touch);
296 	input_report_abs(dev, ABS_X, x);
297 	input_report_abs(dev, ABS_Y, y);
298 	input_sync(dev);
299 }
300 
301 static void vsxxxaa_handle_POR_packet(struct vsxxxaa *mouse)
302 {
303 	struct input_dev *dev = mouse->dev;
304 	unsigned char *buf = mouse->buf;
305 	int left, middle, right;
306 	unsigned char error;
307 
308 	/*
309 	 * Check for Power-On-Reset packets. These are sent out
310 	 * after plugging the mouse in, or when explicitly
311 	 * requested by sending 'T'.
312 	 *
313 	 * [0]:	1	0	1	0	R3	R2	R1	R0
314 	 * [1]:	0	M2	M1	M0	D3	D2	D1	D0
315 	 * [2]:	0	E6	E5	E4	E3	E2	E1	E0
316 	 * [3]:	0	0	0	0	0	Left	Middle	Right
317 	 *
318 	 * M: manufacturer location code
319 	 * R: revision code
320 	 * E: Error code. If it's in the range of 0x00..0x1f, only some
321 	 *    minor problem occurred. Errors >= 0x20 are considered bad
322 	 *    and the device may not work properly...
323 	 * D: <0010> == mouse, <0100> == tablet
324 	 */
325 
326 	mouse->version = buf[0] & 0x0f;
327 	mouse->country = (buf[1] >> 4) & 0x07;
328 	mouse->type = buf[1] & 0x0f;
329 	error = buf[2] & 0x7f;
330 
331 	/*
332 	 * Get button state. It's the low three bits
333 	 * (for three buttons) of byte 0. Maybe even the bit <3>
334 	 * has some meaning if a tablet is attached.
335 	 */
336 	left	= buf[0] & 0x04;
337 	middle	= buf[0] & 0x02;
338 	right	= buf[0] & 0x01;
339 
340 	vsxxxaa_drop_bytes(mouse, 4);
341 	vsxxxaa_detection_done(mouse);
342 
343 	if (error <= 0x1f) {
344 		/* No (serious) error. Report buttons */
345 		input_report_key(dev, BTN_LEFT, left);
346 		input_report_key(dev, BTN_MIDDLE, middle);
347 		input_report_key(dev, BTN_RIGHT, right);
348 		input_report_key(dev, BTN_TOUCH, 0);
349 		input_sync(dev);
350 
351 		if (error != 0)
352 			printk(KERN_INFO "Your %s on %s reports error=0x%02x\n",
353 				mouse->name, mouse->phys, error);
354 
355 	}
356 
357 	/*
358 	 * If the mouse was hot-plugged, we need to force differential mode
359 	 * now... However, give it a second to recover from it's reset.
360 	 */
361 	printk(KERN_NOTICE
362 		"%s on %s: Forcing standard packet format, "
363 		"incremental streaming mode and 72 samples/sec\n",
364 		mouse->name, mouse->phys);
365 	serio_write(mouse->serio, 'S');	/* Standard format */
366 	mdelay(50);
367 	serio_write(mouse->serio, 'R');	/* Incremental */
368 	mdelay(50);
369 	serio_write(mouse->serio, 'L');	/* 72 samples/sec */
370 }
371 
372 static void vsxxxaa_parse_buffer(struct vsxxxaa *mouse)
373 {
374 	unsigned char *buf = mouse->buf;
375 	int stray_bytes;
376 
377 	/*
378 	 * Parse buffer to death...
379 	 */
380 	do {
381 		/*
382 		 * Out of sync? Throw away what we don't understand. Each
383 		 * packet starts with a byte whose bit 7 is set. Unhandled
384 		 * packets (ie. which we don't know about or simply b0rk3d
385 		 * data...) will get shifted out of the buffer after some
386 		 * activity on the mouse.
387 		 */
388 		while (mouse->count > 0 && !IS_HDR_BYTE(buf[0])) {
389 			printk(KERN_ERR "%s on %s: Dropping a byte to regain "
390 				"sync with mouse data stream...\n",
391 				mouse->name, mouse->phys);
392 			vsxxxaa_drop_bytes(mouse, 1);
393 		}
394 
395 		/*
396 		 * Check for packets we know about.
397 		 */
398 
399 		if (vsxxxaa_smells_like_packet(mouse, VSXXXAA_PACKET_REL, 3)) {
400 			/* Check for broken packet */
401 			stray_bytes = vsxxxaa_check_packet(mouse, 3);
402 			if (!stray_bytes)
403 				vsxxxaa_handle_REL_packet(mouse);
404 
405 		} else if (vsxxxaa_smells_like_packet(mouse,
406 						      VSXXXAA_PACKET_ABS, 5)) {
407 			/* Check for broken packet */
408 			stray_bytes = vsxxxaa_check_packet(mouse, 5);
409 			if (!stray_bytes)
410 				vsxxxaa_handle_ABS_packet(mouse);
411 
412 		} else if (vsxxxaa_smells_like_packet(mouse,
413 						      VSXXXAA_PACKET_POR, 4)) {
414 			/* Check for broken packet */
415 			stray_bytes = vsxxxaa_check_packet(mouse, 4);
416 			if (!stray_bytes)
417 				vsxxxaa_handle_POR_packet(mouse);
418 
419 		} else {
420 			break; /* No REL, ABS or POR packet found */
421 		}
422 
423 		if (stray_bytes > 0) {
424 			printk(KERN_ERR "Dropping %d bytes now...\n",
425 				stray_bytes);
426 			vsxxxaa_drop_bytes(mouse, stray_bytes);
427 		}
428 
429 	} while (1);
430 }
431 
432 static irqreturn_t vsxxxaa_interrupt(struct serio *serio,
433 				     unsigned char data, unsigned int flags)
434 {
435 	struct vsxxxaa *mouse = serio_get_drvdata(serio);
436 
437 	vsxxxaa_queue_byte(mouse, data);
438 	vsxxxaa_parse_buffer(mouse);
439 
440 	return IRQ_HANDLED;
441 }
442 
443 static void vsxxxaa_disconnect(struct serio *serio)
444 {
445 	struct vsxxxaa *mouse = serio_get_drvdata(serio);
446 
447 	serio_close(serio);
448 	serio_set_drvdata(serio, NULL);
449 	input_unregister_device(mouse->dev);
450 	kfree(mouse);
451 }
452 
453 static int vsxxxaa_connect(struct serio *serio, struct serio_driver *drv)
454 {
455 	struct vsxxxaa *mouse;
456 	struct input_dev *input_dev;
457 	int err = -ENOMEM;
458 
459 	mouse = kzalloc(sizeof(struct vsxxxaa), GFP_KERNEL);
460 	input_dev = input_allocate_device();
461 	if (!mouse || !input_dev)
462 		goto fail1;
463 
464 	mouse->dev = input_dev;
465 	mouse->serio = serio;
466 	strlcat(mouse->name, "DEC VSXXX-AA/-GA mouse or VSXXX-AB digitizer",
467 		 sizeof(mouse->name));
468 	snprintf(mouse->phys, sizeof(mouse->phys), "%s/input0", serio->phys);
469 
470 	input_dev->name = mouse->name;
471 	input_dev->phys = mouse->phys;
472 	input_dev->id.bustype = BUS_RS232;
473 	input_dev->dev.parent = &serio->dev;
474 
475 	__set_bit(EV_KEY, input_dev->evbit);		/* We have buttons */
476 	__set_bit(EV_REL, input_dev->evbit);
477 	__set_bit(EV_ABS, input_dev->evbit);
478 	__set_bit(BTN_LEFT, input_dev->keybit);		/* We have 3 buttons */
479 	__set_bit(BTN_MIDDLE, input_dev->keybit);
480 	__set_bit(BTN_RIGHT, input_dev->keybit);
481 	__set_bit(BTN_TOUCH, input_dev->keybit);	/* ...and Tablet */
482 	__set_bit(REL_X, input_dev->relbit);
483 	__set_bit(REL_Y, input_dev->relbit);
484 	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
485 	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
486 
487 	serio_set_drvdata(serio, mouse);
488 
489 	err = serio_open(serio, drv);
490 	if (err)
491 		goto fail2;
492 
493 	/*
494 	 * Request selftest. Standard packet format and differential
495 	 * mode will be requested after the device ID'ed successfully.
496 	 */
497 	serio_write(serio, 'T'); /* Test */
498 
499 	err = input_register_device(input_dev);
500 	if (err)
501 		goto fail3;
502 
503 	return 0;
504 
505  fail3:	serio_close(serio);
506  fail2:	serio_set_drvdata(serio, NULL);
507  fail1:	input_free_device(input_dev);
508 	kfree(mouse);
509 	return err;
510 }
511 
512 static struct serio_device_id vsxxaa_serio_ids[] = {
513 	{
514 		.type	= SERIO_RS232,
515 		.proto	= SERIO_VSXXXAA,
516 		.id	= SERIO_ANY,
517 		.extra	= SERIO_ANY,
518 	},
519 	{ 0 }
520 };
521 
522 MODULE_DEVICE_TABLE(serio, vsxxaa_serio_ids);
523 
524 static struct serio_driver vsxxxaa_drv = {
525 	.driver		= {
526 		.name	= "vsxxxaa",
527 	},
528 	.description	= DRIVER_DESC,
529 	.id_table	= vsxxaa_serio_ids,
530 	.connect	= vsxxxaa_connect,
531 	.interrupt	= vsxxxaa_interrupt,
532 	.disconnect	= vsxxxaa_disconnect,
533 };
534 
535 module_serio_driver(vsxxxaa_drv);
536