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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for the Gravis Grip Multiport, a gamepad "hub" that
4 * connects up to four 9-pin digital gamepads/joysticks.
5 * Driver tested on SMP and UP kernel versions 2.4.18-4 and 2.4.18-5.
6 *
7 * Thanks to Chris Gassib for helpful advice.
8 *
9 * Copyright (c) 2002 Brian Bonnlander, Bill Soudan
10 * Copyright (c) 1998-2000 Vojtech Pavlik
11 */
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/gameport.h>
17#include <linux/input.h>
18#include <linux/delay.h>
19#include <linux/proc_fs.h>
20#include <linux/jiffies.h>
21
22#define DRIVER_DESC "Gravis Grip Multiport driver"
23
24MODULE_AUTHOR("Brian Bonnlander");
25MODULE_DESCRIPTION(DRIVER_DESC);
26MODULE_LICENSE("GPL");
27
28#ifdef GRIP_DEBUG
29#define dbg(format, arg...) printk(KERN_ERR __FILE__ ": " format "\n" , ## arg)
30#else
31#define dbg(format, arg...) do {} while (0)
32#endif
33
34#define GRIP_MAX_PORTS 4
35/*
36 * Grip multiport state
37 */
38
39struct grip_port {
40 struct input_dev *dev;
41 int mode;
42 int registered;
43
44 /* individual gamepad states */
45 int buttons;
46 int xaxes;
47 int yaxes;
48 int dirty; /* has the state been updated? */
49};
50
51struct grip_mp {
52 struct gameport *gameport;
53 struct grip_port *port[GRIP_MAX_PORTS];
54 int reads;
55 int bads;
56};
57
58/*
59 * Multiport packet interpretation
60 */
61
62#define PACKET_FULL 0x80000000 /* packet is full */
63#define PACKET_IO_FAST 0x40000000 /* 3 bits per gameport read */
64#define PACKET_IO_SLOW 0x20000000 /* 1 bit per gameport read */
65#define PACKET_MP_MORE 0x04000000 /* multiport wants to send more */
66#define PACKET_MP_DONE 0x02000000 /* multiport done sending */
67
68/*
69 * Packet status code interpretation
70 */
71
72#define IO_GOT_PACKET 0x0100 /* Got a packet */
73#define IO_MODE_FAST 0x0200 /* Used 3 data bits per gameport read */
74#define IO_SLOT_CHANGE 0x0800 /* Multiport physical slot status changed */
75#define IO_DONE 0x1000 /* Multiport is done sending packets */
76#define IO_RETRY 0x4000 /* Try again later to get packet */
77#define IO_RESET 0x8000 /* Force multiport to resend all packets */
78
79/*
80 * Gamepad configuration data. Other 9-pin digital joystick devices
81 * may work with the multiport, so this may not be an exhaustive list!
82 * Commodore 64 joystick remains untested.
83 */
84
85#define GRIP_INIT_DELAY 2000 /* 2 ms */
86
87#define GRIP_MODE_NONE 0
88#define GRIP_MODE_RESET 1
89#define GRIP_MODE_GP 2
90#define GRIP_MODE_C64 3
91
92static const int grip_btn_gp[] = { BTN_TR, BTN_TL, BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, -1 };
93static const int grip_btn_c64[] = { BTN_JOYSTICK, -1 };
94
95static const int grip_abs_gp[] = { ABS_X, ABS_Y, -1 };
96static const int grip_abs_c64[] = { ABS_X, ABS_Y, -1 };
97
98static const int *grip_abs[] = { NULL, NULL, grip_abs_gp, grip_abs_c64 };
99static const int *grip_btn[] = { NULL, NULL, grip_btn_gp, grip_btn_c64 };
100
101static const char *grip_name[] = { NULL, NULL, "Gravis Grip Pad", "Commodore 64 Joystick" };
102
103static const int init_seq[] = {
104 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1,
105 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,
106 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1,
107 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1 };
108
109/* Maps multiport directional values to X,Y axis values (each axis encoded in 3 bits) */
110
111static const int axis_map[] = { 5, 9, 1, 5, 6, 10, 2, 6, 4, 8, 0, 4, 5, 9, 1, 5 };
112
113static int register_slot(int i, struct grip_mp *grip);
114
115/*
116 * Returns whether an odd or even number of bits are on in pkt.
117 */
118
119static int bit_parity(u32 pkt)
120{
121 int x = pkt ^ (pkt >> 16);
122 x ^= x >> 8;
123 x ^= x >> 4;
124 x ^= x >> 2;
125 x ^= x >> 1;
126 return x & 1;
127}
128
129/*
130 * Poll gameport; return true if all bits set in 'onbits' are on and
131 * all bits set in 'offbits' are off.
132 */
133
134static inline int poll_until(u8 onbits, u8 offbits, int u_sec, struct gameport* gp, u8 *data)
135{
136 int i, nloops;
137
138 nloops = gameport_time(gp, u_sec);
139 for (i = 0; i < nloops; i++) {
140 *data = gameport_read(gp);
141 if ((*data & onbits) == onbits &&
142 (~(*data) & offbits) == offbits)
143 return 1;
144 }
145 dbg("gameport timed out after %d microseconds.\n", u_sec);
146 return 0;
147}
148
149/*
150 * Gets a 28-bit packet from the multiport.
151 *
152 * After getting a packet successfully, commands encoded by sendcode may
153 * be sent to the multiport.
154 *
155 * The multiport clock value is reflected in gameport bit B4.
156 *
157 * Returns a packet status code indicating whether packet is valid, the transfer
158 * mode, and any error conditions.
159 *
160 * sendflags: current I/O status
161 * sendcode: data to send to the multiport if sendflags is nonzero
162 */
163
164static int mp_io(struct gameport* gameport, int sendflags, int sendcode, u32 *packet)
165{
166 u8 raw_data; /* raw data from gameport */
167 u8 data_mask; /* packet data bits from raw_data */
168 u32 pkt; /* packet temporary storage */
169 int bits_per_read; /* num packet bits per gameport read */
170 int portvals = 0; /* used for port value sanity check */
171 int i;
172
173 /* Gameport bits B0, B4, B5 should first be off, then B4 should come on. */
174
175 *packet = 0;
176 raw_data = gameport_read(gameport);
177 if (raw_data & 1)
178 return IO_RETRY;
179
180 for (i = 0; i < 64; i++) {
181 raw_data = gameport_read(gameport);
182 portvals |= 1 << ((raw_data >> 4) & 3); /* Demux B4, B5 */
183 }
184
185 if (portvals == 1) { /* B4, B5 off */
186 raw_data = gameport_read(gameport);
187 portvals = raw_data & 0xf0;
188
189 if (raw_data & 0x31)
190 return IO_RESET;
191 gameport_trigger(gameport);
192
193 if (!poll_until(0x10, 0, 308, gameport, &raw_data))
194 return IO_RESET;
195 } else
196 return IO_RETRY;
197
198 /* Determine packet transfer mode and prepare for packet construction. */
199
200 if (raw_data & 0x20) { /* 3 data bits/read */
201 portvals |= raw_data >> 4; /* Compare B4-B7 before & after trigger */
202
203 if (portvals != 0xb)
204 return 0;
205 data_mask = 7;
206 bits_per_read = 3;
207 pkt = (PACKET_FULL | PACKET_IO_FAST) >> 28;
208 } else { /* 1 data bit/read */
209 data_mask = 1;
210 bits_per_read = 1;
211 pkt = (PACKET_FULL | PACKET_IO_SLOW) >> 28;
212 }
213
214 /* Construct a packet. Final data bits must be zero. */
215
216 while (1) {
217 if (!poll_until(0, 0x10, 77, gameport, &raw_data))
218 return IO_RESET;
219 raw_data = (raw_data >> 5) & data_mask;
220
221 if (pkt & PACKET_FULL)
222 break;
223 pkt = (pkt << bits_per_read) | raw_data;
224
225 if (!poll_until(0x10, 0, 77, gameport, &raw_data))
226 return IO_RESET;
227 }
228
229 if (raw_data)
230 return IO_RESET;
231
232 /* If 3 bits/read used, drop from 30 bits to 28. */
233
234 if (bits_per_read == 3) {
235 pkt = (pkt & 0xffff0000) | ((pkt << 1) & 0xffff);
236 pkt = (pkt >> 2) | 0xf0000000;
237 }
238
239 if (bit_parity(pkt) == 1)
240 return IO_RESET;
241
242 /* Acknowledge packet receipt */
243
244 if (!poll_until(0x30, 0, 77, gameport, &raw_data))
245 return IO_RESET;
246
247 raw_data = gameport_read(gameport);
248
249 if (raw_data & 1)
250 return IO_RESET;
251
252 gameport_trigger(gameport);
253
254 if (!poll_until(0, 0x20, 77, gameport, &raw_data))
255 return IO_RESET;
256
257 /* Return if we just wanted the packet or multiport wants to send more */
258
259 *packet = pkt;
260 if ((sendflags == 0) || ((sendflags & IO_RETRY) && !(pkt & PACKET_MP_DONE)))
261 return IO_GOT_PACKET;
262
263 if (pkt & PACKET_MP_MORE)
264 return IO_GOT_PACKET | IO_RETRY;
265
266 /* Multiport is done sending packets and is ready to receive data */
267
268 if (!poll_until(0x20, 0, 77, gameport, &raw_data))
269 return IO_GOT_PACKET | IO_RESET;
270
271 raw_data = gameport_read(gameport);
272 if (raw_data & 1)
273 return IO_GOT_PACKET | IO_RESET;
274
275 /* Trigger gameport based on bits in sendcode */
276
277 gameport_trigger(gameport);
278 do {
279 if (!poll_until(0x20, 0x10, 116, gameport, &raw_data))
280 return IO_GOT_PACKET | IO_RESET;
281
282 if (!poll_until(0x30, 0, 193, gameport, &raw_data))
283 return IO_GOT_PACKET | IO_RESET;
284
285 if (raw_data & 1)
286 return IO_GOT_PACKET | IO_RESET;
287
288 if (sendcode & 1)
289 gameport_trigger(gameport);
290
291 sendcode >>= 1;
292 } while (sendcode);
293
294 return IO_GOT_PACKET | IO_MODE_FAST;
295}
296
297/*
298 * Disables and restores interrupts for mp_io(), which does the actual I/O.
299 */
300
301static int multiport_io(struct gameport* gameport, int sendflags, int sendcode, u32 *packet)
302{
303 int status;
304 unsigned long flags;
305
306 local_irq_save(flags);
307 status = mp_io(gameport, sendflags, sendcode, packet);
308 local_irq_restore(flags);
309
310 return status;
311}
312
313/*
314 * Puts multiport into digital mode. Multiport LED turns green.
315 *
316 * Returns true if a valid digital packet was received, false otherwise.
317 */
318
319static int dig_mode_start(struct gameport *gameport, u32 *packet)
320{
321 int i;
322 int flags, tries = 0, bads = 0;
323
324 for (i = 0; i < ARRAY_SIZE(init_seq); i++) { /* Send magic sequence */
325 if (init_seq[i])
326 gameport_trigger(gameport);
327 udelay(GRIP_INIT_DELAY);
328 }
329
330 for (i = 0; i < 16; i++) /* Wait for multiport to settle */
331 udelay(GRIP_INIT_DELAY);
332
333 while (tries < 64 && bads < 8) { /* Reset multiport and try getting a packet */
334
335 flags = multiport_io(gameport, IO_RESET, 0x27, packet);
336
337 if (flags & IO_MODE_FAST)
338 return 1;
339
340 if (flags & IO_RETRY)
341 tries++;
342 else
343 bads++;
344 }
345 return 0;
346}
347
348/*
349 * Packet structure: B0-B15 => gamepad state
350 * B16-B20 => gamepad device type
351 * B21-B24 => multiport slot index (1-4)
352 *
353 * Known device types: 0x1f (grip pad), 0x0 (no device). Others may exist.
354 *
355 * Returns the packet status.
356 */
357
358static int get_and_decode_packet(struct grip_mp *grip, int flags)
359{
360 struct grip_port *port;
361 u32 packet;
362 int joytype = 0;
363 int slot;
364
365 /* Get a packet and check for validity */
366
367 flags &= IO_RESET | IO_RETRY;
368 flags = multiport_io(grip->gameport, flags, 0, &packet);
369 grip->reads++;
370
371 if (packet & PACKET_MP_DONE)
372 flags |= IO_DONE;
373
374 if (flags && !(flags & IO_GOT_PACKET)) {
375 grip->bads++;
376 return flags;
377 }
378
379 /* Ignore non-gamepad packets, e.g. multiport hardware version */
380
381 slot = ((packet >> 21) & 0xf) - 1;
382 if ((slot < 0) || (slot > 3))
383 return flags;
384
385 port = grip->port[slot];
386
387 /*
388 * Handle "reset" packets, which occur at startup, and when gamepads
389 * are removed or plugged in. May contain configuration of a new gamepad.
390 */
391
392 joytype = (packet >> 16) & 0x1f;
393 if (!joytype) {
394
395 if (port->registered) {
396 printk(KERN_INFO "grip_mp: removing %s, slot %d\n",
397 grip_name[port->mode], slot);
398 input_unregister_device(port->dev);
399 port->registered = 0;
400 }
401 dbg("Reset: grip multiport slot %d\n", slot);
402 port->mode = GRIP_MODE_RESET;
403 flags |= IO_SLOT_CHANGE;
404 return flags;
405 }
406
407 /* Interpret a grip pad packet */
408
409 if (joytype == 0x1f) {
410
411 int dir = (packet >> 8) & 0xf; /* eight way directional value */
412 port->buttons = (~packet) & 0xff;
413 port->yaxes = ((axis_map[dir] >> 2) & 3) - 1;
414 port->xaxes = (axis_map[dir] & 3) - 1;
415 port->dirty = 1;
416
417 if (port->mode == GRIP_MODE_RESET)
418 flags |= IO_SLOT_CHANGE;
419
420 port->mode = GRIP_MODE_GP;
421
422 if (!port->registered) {
423 dbg("New Grip pad in multiport slot %d.\n", slot);
424 if (register_slot(slot, grip)) {
425 port->mode = GRIP_MODE_RESET;
426 port->dirty = 0;
427 }
428 }
429 return flags;
430 }
431
432 /* Handle non-grip device codes. For now, just print diagnostics. */
433
434 {
435 static int strange_code = 0;
436 if (strange_code != joytype) {
437 printk(KERN_INFO "Possible non-grip pad/joystick detected.\n");
438 printk(KERN_INFO "Got joy type 0x%x and packet 0x%x.\n", joytype, packet);
439 strange_code = joytype;
440 }
441 }
442 return flags;
443}
444
445/*
446 * Returns true if all multiport slot states appear valid.
447 */
448
449static int slots_valid(struct grip_mp *grip)
450{
451 int flags, slot, invalid = 0, active = 0;
452
453 flags = get_and_decode_packet(grip, 0);
454 if (!(flags & IO_GOT_PACKET))
455 return 0;
456
457 for (slot = 0; slot < 4; slot++) {
458 if (grip->port[slot]->mode == GRIP_MODE_RESET)
459 invalid = 1;
460 if (grip->port[slot]->mode != GRIP_MODE_NONE)
461 active = 1;
462 }
463
464 /* Return true if no active slot but multiport sent all its data */
465 if (!active)
466 return (flags & IO_DONE) ? 1 : 0;
467
468 /* Return false if invalid device code received */
469 return invalid ? 0 : 1;
470}
471
472/*
473 * Returns whether the multiport was placed into digital mode and
474 * able to communicate its state successfully.
475 */
476
477static int multiport_init(struct grip_mp *grip)
478{
479 int dig_mode, initialized = 0, tries = 0;
480 u32 packet;
481
482 dig_mode = dig_mode_start(grip->gameport, &packet);
483 while (!dig_mode && tries < 4) {
484 dig_mode = dig_mode_start(grip->gameport, &packet);
485 tries++;
486 }
487
488 if (dig_mode)
489 dbg("multiport_init(): digital mode activated.\n");
490 else {
491 dbg("multiport_init(): unable to activate digital mode.\n");
492 return 0;
493 }
494
495 /* Get packets, store multiport state, and check state's validity */
496 for (tries = 0; tries < 4096; tries++) {
497 if (slots_valid(grip)) {
498 initialized = 1;
499 break;
500 }
501 }
502 dbg("multiport_init(): initialized == %d\n", initialized);
503 return initialized;
504}
505
506/*
507 * Reports joystick state to the linux input layer.
508 */
509
510static void report_slot(struct grip_mp *grip, int slot)
511{
512 struct grip_port *port = grip->port[slot];
513 int i;
514
515 /* Store button states with linux input driver */
516
517 for (i = 0; i < 8; i++)
518 input_report_key(port->dev, grip_btn_gp[i], (port->buttons >> i) & 1);
519
520 /* Store axis states with linux driver */
521
522 input_report_abs(port->dev, ABS_X, port->xaxes);
523 input_report_abs(port->dev, ABS_Y, port->yaxes);
524
525 /* Tell the receiver of the events to process them */
526
527 input_sync(port->dev);
528
529 port->dirty = 0;
530}
531
532/*
533 * Get the multiport state.
534 */
535
536static void grip_poll(struct gameport *gameport)
537{
538 struct grip_mp *grip = gameport_get_drvdata(gameport);
539 int i, npkts, flags;
540
541 for (npkts = 0; npkts < 4; npkts++) {
542 flags = IO_RETRY;
543 for (i = 0; i < 32; i++) {
544 flags = get_and_decode_packet(grip, flags);
545 if ((flags & IO_GOT_PACKET) || !(flags & IO_RETRY))
546 break;
547 }
548 if (flags & IO_DONE)
549 break;
550 }
551
552 for (i = 0; i < 4; i++)
553 if (grip->port[i]->dirty)
554 report_slot(grip, i);
555}
556
557/*
558 * Called when a joystick device file is opened
559 */
560
561static int grip_open(struct input_dev *dev)
562{
563 struct grip_mp *grip = input_get_drvdata(dev);
564
565 gameport_start_polling(grip->gameport);
566 return 0;
567}
568
569/*
570 * Called when a joystick device file is closed
571 */
572
573static void grip_close(struct input_dev *dev)
574{
575 struct grip_mp *grip = input_get_drvdata(dev);
576
577 gameport_stop_polling(grip->gameport);
578}
579
580/*
581 * Tell the linux input layer about a newly plugged-in gamepad.
582 */
583
584static int register_slot(int slot, struct grip_mp *grip)
585{
586 struct grip_port *port = grip->port[slot];
587 struct input_dev *input_dev;
588 int j, t;
589 int err;
590
591 port->dev = input_dev = input_allocate_device();
592 if (!input_dev)
593 return -ENOMEM;
594
595 input_dev->name = grip_name[port->mode];
596 input_dev->id.bustype = BUS_GAMEPORT;
597 input_dev->id.vendor = GAMEPORT_ID_VENDOR_GRAVIS;
598 input_dev->id.product = 0x0100 + port->mode;
599 input_dev->id.version = 0x0100;
600 input_dev->dev.parent = &grip->gameport->dev;
601
602 input_set_drvdata(input_dev, grip);
603
604 input_dev->open = grip_open;
605 input_dev->close = grip_close;
606
607 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
608
609 for (j = 0; (t = grip_abs[port->mode][j]) >= 0; j++)
610 input_set_abs_params(input_dev, t, -1, 1, 0, 0);
611
612 for (j = 0; (t = grip_btn[port->mode][j]) >= 0; j++)
613 if (t > 0)
614 set_bit(t, input_dev->keybit);
615
616 err = input_register_device(port->dev);
617 if (err) {
618 input_free_device(port->dev);
619 return err;
620 }
621
622 port->registered = 1;
623
624 if (port->dirty) /* report initial state, if any */
625 report_slot(grip, slot);
626
627 return 0;
628}
629
630static int grip_connect(struct gameport *gameport, struct gameport_driver *drv)
631{
632 struct grip_mp *grip;
633 int err;
634
635 grip = kzalloc_obj(*grip);
636 if (!grip)
637 return -ENOMEM;
638
639 grip->gameport = gameport;
640
641 gameport_set_drvdata(gameport, grip);
642
643 err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
644 if (err)
645 goto fail1;
646
647 gameport_set_poll_handler(gameport, grip_poll);
648 gameport_set_poll_interval(gameport, 20);
649
650 if (!multiport_init(grip)) {
651 err = -ENODEV;
652 goto fail2;
653 }
654
655 if (!grip->port[0]->mode && !grip->port[1]->mode && !grip->port[2]->mode && !grip->port[3]->mode) {
656 /* nothing plugged in */
657 err = -ENODEV;
658 goto fail2;
659 }
660
661 return 0;
662
663fail2: gameport_close(gameport);
664fail1: gameport_set_drvdata(gameport, NULL);
665 kfree(grip);
666 return err;
667}
668
669static void grip_disconnect(struct gameport *gameport)
670{
671 struct grip_mp *grip = gameport_get_drvdata(gameport);
672 int i;
673
674 for (i = 0; i < 4; i++)
675 if (grip->port[i]->registered)
676 input_unregister_device(grip->port[i]->dev);
677 gameport_close(gameport);
678 gameport_set_drvdata(gameport, NULL);
679 kfree(grip);
680}
681
682static struct gameport_driver grip_drv = {
683 .driver = {
684 .name = "grip_mp",
685 },
686 .description = DRIVER_DESC,
687 .connect = grip_connect,
688 .disconnect = grip_disconnect,
689};
690
691module_gameport_driver(grip_drv);