1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) 1998-2005 Vojtech Pavlik
4  */
5 
6 /*
7  * Microsoft SideWinder joystick family driver for Linux
8  */
9 
10 /*
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/input.h>
18 #include <linux/gameport.h>
19 #include <linux/jiffies.h>
20 
21 #define DRIVER_DESC	"Microsoft SideWinder joystick family driver"
22 
23 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
24 MODULE_DESCRIPTION(DRIVER_DESC);
25 MODULE_LICENSE("GPL");
26 
27 /*
28  * These are really magic values. Changing them can make a problem go away,
29  * as well as break everything.
30  */
31 
32 #undef SW_DEBUG
33 #undef SW_DEBUG_DATA
34 
35 #define SW_START	600	/* The time we wait for the first bit [600 us] */
36 #define SW_STROBE	60	/* Max time per bit [60 us] */
37 #define SW_TIMEOUT	6	/* Wait for everything to settle [6 ms] */
38 #define SW_KICK		45	/* Wait after A0 fall till kick [45 us] */
39 #define SW_END		8	/* Number of bits before end of packet to kick */
40 #define SW_FAIL		16	/* Number of packet read errors to fail and reinitialize */
41 #define SW_BAD		2	/* Number of packet read errors to switch off 3d Pro optimization */
42 #define SW_OK		64	/* Number of packet read successes to switch optimization back on */
43 #define SW_LENGTH	512	/* Max number of bits in a packet */
44 
45 #ifdef SW_DEBUG
46 #define dbg(format, arg...) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg)
47 #else
48 #define dbg(format, arg...) do {} while (0)
49 #endif
50 
51 /*
52  * SideWinder joystick types ...
53  */
54 
55 #define SW_ID_3DP	0
56 #define SW_ID_GP	1
57 #define SW_ID_PP	2
58 #define SW_ID_FFP	3
59 #define SW_ID_FSP	4
60 #define SW_ID_FFW	5
61 
62 /*
63  * Names, buttons, axes ...
64  */
65 
66 static char *sw_name[] = {	"3D Pro", "GamePad", "Precision Pro", "Force Feedback Pro", "FreeStyle Pro",
67 				"Force Feedback Wheel" };
68 
69 static char sw_abs[][7] = {
70 	{ ABS_X, ABS_Y, ABS_RZ, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
71 	{ ABS_X, ABS_Y },
72 	{ ABS_X, ABS_Y, ABS_RZ, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
73 	{ ABS_X, ABS_Y, ABS_RZ, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
74 	{ ABS_X, ABS_Y,         ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
75 	{ ABS_RX, ABS_RUDDER,   ABS_THROTTLE }};
76 
77 static char sw_bit[][7] = {
78 	{ 10, 10,  9, 10,  1,  1 },
79 	{  1,  1                 },
80 	{ 10, 10,  6,  7,  1,  1 },
81 	{ 10, 10,  6,  7,  1,  1 },
82 	{ 10, 10,  6,  1,  1     },
83 	{ 10,  7,  7,  1,  1     }};
84 
85 static short sw_btn[][12] = {
86 	{ BTN_TRIGGER, BTN_TOP, BTN_THUMB, BTN_THUMB2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_MODE },
87 	{ BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_TL, BTN_TR, BTN_START, BTN_MODE },
88 	{ BTN_TRIGGER, BTN_THUMB, BTN_TOP, BTN_TOP2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_SELECT },
89 	{ BTN_TRIGGER, BTN_THUMB, BTN_TOP, BTN_TOP2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_SELECT },
90 	{ BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_TL, BTN_TR, BTN_START, BTN_MODE, BTN_SELECT },
91 	{ BTN_TRIGGER, BTN_TOP, BTN_THUMB, BTN_THUMB2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4 }};
92 
93 static struct {
94 	int x;
95 	int y;
96 } sw_hat_to_axis[] = {{ 0, 0}, { 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};
97 
98 struct sw {
99 	struct gameport *gameport;
100 	struct input_dev *dev[4];
101 	char name[64];
102 	char phys[4][32];
103 	int length;
104 	int type;
105 	int bits;
106 	int number;
107 	int fail;
108 	int ok;
109 	int reads;
110 	int bads;
111 };
112 
113 /*
114  * sw_read_packet() is a function which reads either a data packet, or an
115  * identification packet from a SideWinder joystick. The protocol is very,
116  * very, very braindamaged. Microsoft patented it in US patent #5628686.
117  */
118 
119 static int sw_read_packet(struct gameport *gameport, unsigned char *buf, int length, int id)
120 {
121 	unsigned long flags;
122 	int timeout, bitout, sched, i, kick, start, strobe;
123 	unsigned char pending, u, v;
124 
125 	i = -id;						/* Don't care about data, only want ID */
126 	timeout = id ? gameport_time(gameport, SW_TIMEOUT * 1000) : 0; /* Set up global timeout for ID packet */
127 	kick = id ? gameport_time(gameport, SW_KICK) : 0;	/* Set up kick timeout for ID packet */
128 	start = gameport_time(gameport, SW_START);
129 	strobe = gameport_time(gameport, SW_STROBE);
130 	bitout = start;
131 	pending = 0;
132 	sched = 0;
133 
134         local_irq_save(flags);					/* Quiet, please */
135 
136 	gameport_trigger(gameport);				/* Trigger */
137 	v = gameport_read(gameport);
138 
139 	do {
140 		bitout--;
141 		u = v;
142 		v = gameport_read(gameport);
143 	} while (!(~v & u & 0x10) && (bitout > 0));		/* Wait for first falling edge on clock */
144 
145 	if (bitout > 0)
146 		bitout = strobe;				/* Extend time if not timed out */
147 
148 	while ((timeout > 0 || bitout > 0) && (i < length)) {
149 
150 		timeout--;
151 		bitout--;					/* Decrement timers */
152 		sched--;
153 
154 		u = v;
155 		v = gameport_read(gameport);
156 
157 		if ((~u & v & 0x10) && (bitout > 0)) {		/* Rising edge on clock - data bit */
158 			if (i >= 0)				/* Want this data */
159 				buf[i] = v >> 5;		/* Store it */
160 			i++;					/* Advance index */
161 			bitout = strobe;			/* Extend timeout for next bit */
162 		}
163 
164 		if (kick && (~v & u & 0x01)) {			/* Falling edge on axis 0 */
165 			sched = kick;				/* Schedule second trigger */
166 			kick = 0;				/* Don't schedule next time on falling edge */
167 			pending = 1;				/* Mark schedule */
168 		}
169 
170 		if (pending && sched < 0 && (i > -SW_END)) {	/* Second trigger time */
171 			gameport_trigger(gameport);		/* Trigger */
172 			bitout = start;				/* Long bit timeout */
173 			pending = 0;				/* Unmark schedule */
174 			timeout = 0;				/* Switch from global to bit timeouts */
175 		}
176 	}
177 
178 	local_irq_restore(flags);					/* Done - relax */
179 
180 #ifdef SW_DEBUG_DATA
181 	{
182 		int j;
183 		printk(KERN_DEBUG "sidewinder.c: Read %d triplets. [", i);
184 		for (j = 0; j < i; j++) printk("%d", buf[j]);
185 		printk("]\n");
186 	}
187 #endif
188 
189 	return i;
190 }
191 
192 /*
193  * sw_get_bits() and GB() compose bits from the triplet buffer into a __u64.
194  * Parameter 'pos' is bit number inside packet where to start at, 'num' is number
195  * of bits to be read, 'shift' is offset in the resulting __u64 to start at, bits
196  * is number of bits per triplet.
197  */
198 
199 #define GB(pos,num) sw_get_bits(buf, pos, num, sw->bits)
200 
201 static __u64 sw_get_bits(unsigned char *buf, int pos, int num, char bits)
202 {
203 	__u64 data = 0;
204 	int tri = pos % bits;						/* Start position */
205 	int i   = pos / bits;
206 	int bit = 0;
207 
208 	while (num--) {
209 		data |= (__u64)((buf[i] >> tri++) & 1) << bit++;	/* Transfer bit */
210 		if (tri == bits) {
211 			i++;						/* Next triplet */
212 			tri = 0;
213 		}
214 	}
215 
216 	return data;
217 }
218 
219 /*
220  * sw_init_digital() initializes a SideWinder 3D Pro joystick
221  * into digital mode.
222  */
223 
224 static void sw_init_digital(struct gameport *gameport)
225 {
226 	static const int seq[] = { 140, 140+725, 140+300, 0 };
227 	unsigned long flags;
228 	int i, t;
229 
230         local_irq_save(flags);
231 
232 	i = 0;
233         do {
234                 gameport_trigger(gameport);			/* Trigger */
235 		t = gameport_time(gameport, SW_TIMEOUT * 1000);
236 		while ((gameport_read(gameport) & 1) && t) t--;	/* Wait for axis to fall back to 0 */
237                 udelay(seq[i]);					/* Delay magic time */
238         } while (seq[++i]);
239 
240 	gameport_trigger(gameport);				/* Last trigger */
241 
242 	local_irq_restore(flags);
243 }
244 
245 /*
246  * sw_parity() computes parity of __u64
247  */
248 
249 static int sw_parity(__u64 t)
250 {
251 	int x = t ^ (t >> 32);
252 
253 	x ^= x >> 16;
254 	x ^= x >> 8;
255 	x ^= x >> 4;
256 	x ^= x >> 2;
257 	x ^= x >> 1;
258 	return x & 1;
259 }
260 
261 /*
262  * sw_ccheck() checks synchronization bits and computes checksum of nibbles.
263  */
264 
265 static int sw_check(__u64 t)
266 {
267 	unsigned char sum = 0;
268 
269 	if ((t & 0x8080808080808080ULL) ^ 0x80)			/* Sync */
270 		return -1;
271 
272 	while (t) {						/* Sum */
273 		sum += t & 0xf;
274 		t >>= 4;
275 	}
276 
277 	return sum & 0xf;
278 }
279 
280 /*
281  * sw_parse() analyzes SideWinder joystick data, and writes the results into
282  * the axes and buttons arrays.
283  */
284 
285 static int sw_parse(unsigned char *buf, struct sw *sw)
286 {
287 	int hat, i, j;
288 	struct input_dev *dev;
289 
290 	switch (sw->type) {
291 
292 		case SW_ID_3DP:
293 
294 			if (sw_check(GB(0,64)) || (hat = (GB(6,1) << 3) | GB(60,3)) > 8)
295 				return -1;
296 
297 			dev = sw->dev[0];
298 
299 			input_report_abs(dev, ABS_X,        (GB( 3,3) << 7) | GB(16,7));
300 			input_report_abs(dev, ABS_Y,        (GB( 0,3) << 7) | GB(24,7));
301 			input_report_abs(dev, ABS_RZ,       (GB(35,2) << 7) | GB(40,7));
302 			input_report_abs(dev, ABS_THROTTLE, (GB(32,3) << 7) | GB(48,7));
303 
304 			input_report_abs(dev, ABS_HAT0X, sw_hat_to_axis[hat].x);
305 			input_report_abs(dev, ABS_HAT0Y, sw_hat_to_axis[hat].y);
306 
307 			for (j = 0; j < 7; j++)
308 				input_report_key(dev, sw_btn[SW_ID_3DP][j], !GB(j+8,1));
309 
310 			input_report_key(dev, BTN_BASE4, !GB(38,1));
311 			input_report_key(dev, BTN_BASE5, !GB(37,1));
312 
313 			input_sync(dev);
314 
315 			return 0;
316 
317 		case SW_ID_GP:
318 
319 			for (i = 0; i < sw->number; i ++) {
320 
321 				if (sw_parity(GB(i*15,15)))
322 					return -1;
323 
324 				input_report_abs(sw->dev[i], ABS_X, GB(i*15+3,1) - GB(i*15+2,1));
325 				input_report_abs(sw->dev[i], ABS_Y, GB(i*15+0,1) - GB(i*15+1,1));
326 
327 				for (j = 0; j < 10; j++)
328 					input_report_key(sw->dev[i], sw_btn[SW_ID_GP][j], !GB(i*15+j+4,1));
329 
330 				input_sync(sw->dev[i]);
331 			}
332 
333 			return 0;
334 
335 		case SW_ID_PP:
336 		case SW_ID_FFP:
337 
338 			if (!sw_parity(GB(0,48)) || (hat = GB(42,4)) > 8)
339 				return -1;
340 
341 			dev = sw->dev[0];
342 			input_report_abs(dev, ABS_X,        GB( 9,10));
343 			input_report_abs(dev, ABS_Y,        GB(19,10));
344 			input_report_abs(dev, ABS_RZ,       GB(36, 6));
345 			input_report_abs(dev, ABS_THROTTLE, GB(29, 7));
346 
347 			input_report_abs(dev, ABS_HAT0X, sw_hat_to_axis[hat].x);
348 			input_report_abs(dev, ABS_HAT0Y, sw_hat_to_axis[hat].y);
349 
350 			for (j = 0; j < 9; j++)
351 				input_report_key(dev, sw_btn[SW_ID_PP][j], !GB(j,1));
352 
353 			input_sync(dev);
354 
355 			return 0;
356 
357 		case SW_ID_FSP:
358 
359 			if (!sw_parity(GB(0,43)) || (hat = GB(28,4)) > 8)
360 				return -1;
361 
362 			dev = sw->dev[0];
363 			input_report_abs(dev, ABS_X,        GB( 0,10));
364 			input_report_abs(dev, ABS_Y,        GB(16,10));
365 			input_report_abs(dev, ABS_THROTTLE, GB(32, 6));
366 
367 			input_report_abs(dev, ABS_HAT0X, sw_hat_to_axis[hat].x);
368 			input_report_abs(dev, ABS_HAT0Y, sw_hat_to_axis[hat].y);
369 
370 			for (j = 0; j < 6; j++)
371 				input_report_key(dev, sw_btn[SW_ID_FSP][j], !GB(j+10,1));
372 
373 			input_report_key(dev, BTN_TR,     !GB(26,1));
374 			input_report_key(dev, BTN_START,  !GB(27,1));
375 			input_report_key(dev, BTN_MODE,   !GB(38,1));
376 			input_report_key(dev, BTN_SELECT, !GB(39,1));
377 
378 			input_sync(dev);
379 
380 			return 0;
381 
382 		case SW_ID_FFW:
383 
384 			if (!sw_parity(GB(0,33)))
385 				return -1;
386 
387 			dev = sw->dev[0];
388 			input_report_abs(dev, ABS_RX,       GB( 0,10));
389 			input_report_abs(dev, ABS_RUDDER,   GB(10, 6));
390 			input_report_abs(dev, ABS_THROTTLE, GB(16, 6));
391 
392 			for (j = 0; j < 8; j++)
393 				input_report_key(dev, sw_btn[SW_ID_FFW][j], !GB(j+22,1));
394 
395 			input_sync(dev);
396 
397 			return 0;
398 	}
399 
400 	return -1;
401 }
402 
403 /*
404  * sw_read() reads SideWinder joystick data, and reinitializes
405  * the joystick in case of persistent problems. This is the function that is
406  * called from the generic code to poll the joystick.
407  */
408 
409 static int sw_read(struct sw *sw)
410 {
411 	unsigned char buf[SW_LENGTH];
412 	int i;
413 
414 	i = sw_read_packet(sw->gameport, buf, sw->length, 0);
415 
416 	if (sw->type == SW_ID_3DP && sw->length == 66 && i != 66) {		/* Broken packet, try to fix */
417 
418 		if (i == 64 && !sw_check(sw_get_bits(buf,0,64,1))) {		/* Last init failed, 1 bit mode */
419 			printk(KERN_WARNING "sidewinder.c: Joystick in wrong mode on %s"
420 				" - going to reinitialize.\n", sw->gameport->phys);
421 			sw->fail = SW_FAIL;					/* Reinitialize */
422 			i = 128;						/* Bogus value */
423 		}
424 
425 		if (i < 66 && GB(0,64) == GB(i*3-66,64))			/* 1 == 3 */
426 			i = 66;							/* Everything is fine */
427 
428 		if (i < 66 && GB(0,64) == GB(66,64))				/* 1 == 2 */
429 			i = 66;							/* Everything is fine */
430 
431 		if (i < 66 && GB(i*3-132,64) == GB(i*3-66,64)) {		/* 2 == 3 */
432 			memmove(buf, buf + i - 22, 22);				/* Move data */
433 			i = 66;							/* Carry on */
434 		}
435 	}
436 
437 	if (i == sw->length && !sw_parse(buf, sw)) {				/* Parse data */
438 
439 		sw->fail = 0;
440 		sw->ok++;
441 
442 		if (sw->type == SW_ID_3DP && sw->length == 66			/* Many packets OK */
443 			&& sw->ok > SW_OK) {
444 
445 			printk(KERN_INFO "sidewinder.c: No more trouble on %s"
446 				" - enabling optimization again.\n", sw->gameport->phys);
447 			sw->length = 22;
448 		}
449 
450 		return 0;
451 	}
452 
453 	sw->ok = 0;
454 	sw->fail++;
455 
456 	if (sw->type == SW_ID_3DP && sw->length == 22 && sw->fail > SW_BAD) {	/* Consecutive bad packets */
457 
458 		printk(KERN_INFO "sidewinder.c: Many bit errors on %s"
459 			" - disabling optimization.\n", sw->gameport->phys);
460 		sw->length = 66;
461 	}
462 
463 	if (sw->fail < SW_FAIL)
464 		return -1;							/* Not enough, don't reinitialize yet */
465 
466 	printk(KERN_WARNING "sidewinder.c: Too many bit errors on %s"
467 		" - reinitializing joystick.\n", sw->gameport->phys);
468 
469 	if (!i && sw->type == SW_ID_3DP) {					/* 3D Pro can be in analog mode */
470 		mdelay(3 * SW_TIMEOUT);
471 		sw_init_digital(sw->gameport);
472 	}
473 
474 	mdelay(SW_TIMEOUT);
475 	i = sw_read_packet(sw->gameport, buf, SW_LENGTH, 0);			/* Read normal data packet */
476 	mdelay(SW_TIMEOUT);
477 	sw_read_packet(sw->gameport, buf, SW_LENGTH, i);			/* Read ID packet, this initializes the stick */
478 
479 	sw->fail = SW_FAIL;
480 
481 	return -1;
482 }
483 
484 static void sw_poll(struct gameport *gameport)
485 {
486 	struct sw *sw = gameport_get_drvdata(gameport);
487 
488 	sw->reads++;
489 	if (sw_read(sw))
490 		sw->bads++;
491 }
492 
493 static int sw_open(struct input_dev *dev)
494 {
495 	struct sw *sw = input_get_drvdata(dev);
496 
497 	gameport_start_polling(sw->gameport);
498 	return 0;
499 }
500 
501 static void sw_close(struct input_dev *dev)
502 {
503 	struct sw *sw = input_get_drvdata(dev);
504 
505 	gameport_stop_polling(sw->gameport);
506 }
507 
508 /*
509  * sw_print_packet() prints the contents of a SideWinder packet.
510  */
511 
512 static void sw_print_packet(char *name, int length, unsigned char *buf, char bits)
513 {
514 	int i;
515 
516 	printk(KERN_INFO "sidewinder.c: %s packet, %d bits. [", name, length);
517 	for (i = (((length + 3) >> 2) - 1); i >= 0; i--)
518 		printk("%x", (int)sw_get_bits(buf, i << 2, 4, bits));
519 	printk("]\n");
520 }
521 
522 /*
523  * sw_3dp_id() translates the 3DP id into a human legible string.
524  * Unfortunately I don't know how to do this for the other SW types.
525  */
526 
527 static void sw_3dp_id(unsigned char *buf, char *comment, size_t size)
528 {
529 	int i;
530 	char pnp[8], rev[9];
531 
532 	for (i = 0; i < 7; i++)						/* ASCII PnP ID */
533 		pnp[i] = sw_get_bits(buf, 24+8*i, 8, 1);
534 
535 	for (i = 0; i < 8; i++)						/* ASCII firmware revision */
536 		rev[i] = sw_get_bits(buf, 88+8*i, 8, 1);
537 
538 	pnp[7] = rev[8] = 0;
539 
540 	snprintf(comment, size, " [PnP %d.%02d id %s rev %s]",
541 		(int) ((sw_get_bits(buf, 8, 6, 1) << 6) |		/* Two 6-bit values */
542 			sw_get_bits(buf, 16, 6, 1)) / 100,
543 		(int) ((sw_get_bits(buf, 8, 6, 1) << 6) |
544 			sw_get_bits(buf, 16, 6, 1)) % 100,
545 		 pnp, rev);
546 }
547 
548 /*
549  * sw_guess_mode() checks the upper two button bits for toggling -
550  * indication of that the joystick is in 3-bit mode. This is documented
551  * behavior for 3DP ID packet, and for example the FSP does this in
552  * normal packets instead. Fun ...
553  */
554 
555 static int sw_guess_mode(unsigned char *buf, int len)
556 {
557 	int i;
558 	unsigned char xor = 0;
559 
560 	for (i = 1; i < len; i++)
561 		xor |= (buf[i - 1] ^ buf[i]) & 6;
562 
563 	return !!xor * 2 + 1;
564 }
565 
566 /*
567  * sw_connect() probes for SideWinder type joysticks.
568  */
569 
570 static int sw_connect(struct gameport *gameport, struct gameport_driver *drv)
571 {
572 	struct sw *sw;
573 	struct input_dev *input_dev;
574 	int i, j, k, l;
575 	int err = 0;
576 	unsigned char *buf = NULL;	/* [SW_LENGTH] */
577 	unsigned char *idbuf = NULL;	/* [SW_LENGTH] */
578 	unsigned char m = 1;
579 	char comment[40];
580 
581 	comment[0] = 0;
582 
583 	sw = kzalloc(sizeof(struct sw), GFP_KERNEL);
584 	buf = kmalloc(SW_LENGTH, GFP_KERNEL);
585 	idbuf = kmalloc(SW_LENGTH, GFP_KERNEL);
586 	if (!sw || !buf || !idbuf) {
587 		err = -ENOMEM;
588 		goto fail1;
589 	}
590 
591 	sw->gameport = gameport;
592 
593 	gameport_set_drvdata(gameport, sw);
594 
595 	err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
596 	if (err)
597 		goto fail1;
598 
599 	dbg("Init 0: Opened %s, io %#x, speed %d",
600 		gameport->phys, gameport->io, gameport->speed);
601 
602 	i = sw_read_packet(gameport, buf, SW_LENGTH, 0);		/* Read normal packet */
603 	msleep(SW_TIMEOUT);
604 	dbg("Init 1: Mode %d. Length %d.", m , i);
605 
606 	if (!i) {							/* No data. 3d Pro analog mode? */
607 		sw_init_digital(gameport);				/* Switch to digital */
608 		msleep(SW_TIMEOUT);
609 		i = sw_read_packet(gameport, buf, SW_LENGTH, 0);	/* Retry reading packet */
610 		msleep(SW_TIMEOUT);
611 		dbg("Init 1b: Length %d.", i);
612 		if (!i) {						/* No data -> FAIL */
613 			err = -ENODEV;
614 			goto fail2;
615 		}
616 	}
617 
618 	j = sw_read_packet(gameport, idbuf, SW_LENGTH, i);		/* Read ID. This initializes the stick */
619 	m |= sw_guess_mode(idbuf, j);					/* ID packet should carry mode info [3DP] */
620 	dbg("Init 2: Mode %d. ID Length %d.", m, j);
621 
622 	if (j <= 0) {							/* Read ID failed. Happens in 1-bit mode on PP */
623 		msleep(SW_TIMEOUT);
624 		i = sw_read_packet(gameport, buf, SW_LENGTH, 0);	/* Retry reading packet */
625 		m |= sw_guess_mode(buf, i);
626 		dbg("Init 2b: Mode %d. Length %d.", m, i);
627 		if (!i) {
628 			err = -ENODEV;
629 			goto fail2;
630 		}
631 		msleep(SW_TIMEOUT);
632 		j = sw_read_packet(gameport, idbuf, SW_LENGTH, i);	/* Retry reading ID */
633 		dbg("Init 2c: ID Length %d.", j);
634 	}
635 
636 	sw->type = -1;
637 	k = SW_FAIL;							/* Try SW_FAIL times */
638 	l = 0;
639 
640 	do {
641 		k--;
642 		msleep(SW_TIMEOUT);
643 		i = sw_read_packet(gameport, buf, SW_LENGTH, 0);	/* Read data packet */
644 		dbg("Init 3: Mode %d. Length %d. Last %d. Tries %d.", m, i, l, k);
645 
646 		if (i > l) {						/* Longer? As we can only lose bits, it makes */
647 									/* no sense to try detection for a packet shorter */
648 			l = i;						/* than the previous one */
649 
650 			sw->number = 1;
651 			sw->gameport = gameport;
652 			sw->length = i;
653 			sw->bits = m;
654 
655 			dbg("Init 3a: Case %d.\n", i * m);
656 
657 			switch (i * m) {
658 				case 60:
659 					sw->number++;
660 					fallthrough;
661 				case 45:				/* Ambiguous packet length */
662 					if (j <= 40) {			/* ID length less or eq 40 -> FSP */
663 				case 43:
664 						sw->type = SW_ID_FSP;
665 						break;
666 					}
667 					sw->number++;
668 					fallthrough;
669 				case 30:
670 					sw->number++;
671 					fallthrough;
672 				case 15:
673 					sw->type = SW_ID_GP;
674 					break;
675 				case 33:
676 				case 31:
677 					sw->type = SW_ID_FFW;
678 					break;
679 				case 48:				/* Ambiguous */
680 					if (j == 14) {			/* ID length 14*3 -> FFP */
681 						sw->type = SW_ID_FFP;
682 						sprintf(comment, " [AC %s]", sw_get_bits(idbuf,38,1,3) ? "off" : "on");
683 					} else
684 						sw->type = SW_ID_PP;
685 					break;
686 				case 66:
687 					sw->bits = 3;
688 					fallthrough;
689 				case 198:
690 					sw->length = 22;
691 					fallthrough;
692 				case 64:
693 					sw->type = SW_ID_3DP;
694 					if (j == 160)
695 						sw_3dp_id(idbuf, comment, sizeof(comment));
696 					break;
697 			}
698 		}
699 
700 	} while (k && sw->type == -1);
701 
702 	if (sw->type == -1) {
703 		printk(KERN_WARNING "sidewinder.c: unknown joystick device detected "
704 			"on %s, contact <vojtech@ucw.cz>\n", gameport->phys);
705 		sw_print_packet("ID", j * 3, idbuf, 3);
706 		sw_print_packet("Data", i * m, buf, m);
707 		err = -ENODEV;
708 		goto fail2;
709 	}
710 
711 #ifdef SW_DEBUG
712 	sw_print_packet("ID", j * 3, idbuf, 3);
713 	sw_print_packet("Data", i * m, buf, m);
714 #endif
715 
716 	gameport_set_poll_handler(gameport, sw_poll);
717 	gameport_set_poll_interval(gameport, 20);
718 
719 	k = i;
720 	l = j;
721 
722 	for (i = 0; i < sw->number; i++) {
723 		int bits, code;
724 
725 		snprintf(sw->name, sizeof(sw->name),
726 			 "Microsoft SideWinder %s", sw_name[sw->type]);
727 		snprintf(sw->phys[i], sizeof(sw->phys[i]),
728 			 "%s/input%d", gameport->phys, i);
729 
730 		sw->dev[i] = input_dev = input_allocate_device();
731 		if (!input_dev) {
732 			err = -ENOMEM;
733 			goto fail3;
734 		}
735 
736 		input_dev->name = sw->name;
737 		input_dev->phys = sw->phys[i];
738 		input_dev->id.bustype = BUS_GAMEPORT;
739 		input_dev->id.vendor = GAMEPORT_ID_VENDOR_MICROSOFT;
740 		input_dev->id.product = sw->type;
741 		input_dev->id.version = 0x0100;
742 		input_dev->dev.parent = &gameport->dev;
743 
744 		input_set_drvdata(input_dev, sw);
745 
746 		input_dev->open = sw_open;
747 		input_dev->close = sw_close;
748 
749 		input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
750 
751 		for (j = 0; (bits = sw_bit[sw->type][j]); j++) {
752 			int min, max, fuzz, flat;
753 
754 			code = sw_abs[sw->type][j];
755 			min = bits == 1 ? -1 : 0;
756 			max = (1 << bits) - 1;
757 			fuzz = (bits >> 1) >= 2 ? 1 << ((bits >> 1) - 2) : 0;
758 			flat = code == ABS_THROTTLE || bits < 5 ?
759 				0 : 1 << (bits - 5);
760 
761 			input_set_abs_params(input_dev, code,
762 					     min, max, fuzz, flat);
763 		}
764 
765 		for (j = 0; (code = sw_btn[sw->type][j]); j++)
766 			__set_bit(code, input_dev->keybit);
767 
768 		dbg("%s%s [%d-bit id %d data %d]\n", sw->name, comment, m, l, k);
769 
770 		err = input_register_device(sw->dev[i]);
771 		if (err)
772 			goto fail4;
773 	}
774 
775  out:	kfree(buf);
776 	kfree(idbuf);
777 
778 	return err;
779 
780  fail4:	input_free_device(sw->dev[i]);
781  fail3:	while (--i >= 0)
782 		input_unregister_device(sw->dev[i]);
783  fail2:	gameport_close(gameport);
784  fail1:	gameport_set_drvdata(gameport, NULL);
785 	kfree(sw);
786 	goto out;
787 }
788 
789 static void sw_disconnect(struct gameport *gameport)
790 {
791 	struct sw *sw = gameport_get_drvdata(gameport);
792 	int i;
793 
794 	for (i = 0; i < sw->number; i++)
795 		input_unregister_device(sw->dev[i]);
796 	gameport_close(gameport);
797 	gameport_set_drvdata(gameport, NULL);
798 	kfree(sw);
799 }
800 
801 static struct gameport_driver sw_drv = {
802 	.driver		= {
803 		.name	= "sidewinder",
804 		.owner	= THIS_MODULE,
805 	},
806 	.description	= DRIVER_DESC,
807 	.connect	= sw_connect,
808 	.disconnect	= sw_disconnect,
809 };
810 
811 module_gameport_driver(sw_drv);
812