summaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/via-maciisi.c
blob: 789ee52086fe862a173a204d204690330166a6fd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
/*
 * Device driver for the IIsi-style ADB on some Mac LC and II-class machines
 *
 * Based on via-cuda.c and via-macii.c, as well as the original
 * adb-bus.c, which in turn is somewhat influenced by (but uses no
 * code from) the NetBSD HWDIRECT ADB code.  Original IIsi driver work
 * was done by Robert Thompson and integrated into the old style
 * driver by Michael Schmitz.
 *
 * Original sources (c) Alan Cox, Paul Mackerras, and others.
 *
 * Rewritten for Unified ADB by David Huggins-Daines <dhd@debian.org>
 * 
 * 7/13/2000- extensive changes by Andrew McPherson <andrew@macduff.dhs.org>
 * Works about 30% of the time now.
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>

static volatile unsigned char *via;

/* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
#define RS		0x200		/* skip between registers */
#define B		0		/* B-side data */
#define A		RS		/* A-side data */
#define DIRB		(2*RS)		/* B-side direction (1=output) */
#define DIRA		(3*RS)		/* A-side direction (1=output) */
#define SR		(10*RS)		/* Shift register */
#define ACR		(11*RS)		/* Auxiliary control register */
#define IFR		(13*RS)		/* Interrupt flag register */
#define IER		(14*RS)		/* Interrupt enable register */

/* Bits in B data register: all active low */
#define TREQ		0x08		/* Transfer request (input) */
#define TACK		0x10		/* Transfer acknowledge (output) */
#define TIP		0x20		/* Transfer in progress (output) */
#define ST_MASK		0x30		/* mask for selecting ADB state bits */

/* Bits in ACR */
#define SR_CTRL		0x1c		/* Shift register control bits */
#define SR_EXT		0x0c		/* Shift on external clock */
#define SR_OUT		0x10		/* Shift out if 1 */

/* Bits in IFR and IER */
#define IER_SET		0x80		/* set bits in IER */
#define IER_CLR		0		/* clear bits in IER */
#define SR_INT		0x04		/* Shift register full/empty */
#define SR_DATA		0x08		/* Shift register data */
#define SR_CLOCK	0x10		/* Shift register clock */

#define ADB_DELAY 150

#undef DEBUG_MACIISI_ADB

static struct adb_request* current_req = NULL;
static struct adb_request* last_req = NULL;
static unsigned char maciisi_rbuf[16];
static unsigned char *reply_ptr = NULL;
static int data_index;
static int reading_reply;
static int reply_len;
static int tmp;
static int need_sync;

static enum maciisi_state {
    idle,
    sending,
    reading,
} maciisi_state;

static int maciisi_probe(void);
static int maciisi_init(void);
static int maciisi_send_request(struct adb_request* req, int sync);
static void maciisi_sync(struct adb_request *req);
static int maciisi_write(struct adb_request* req);
static irqreturn_t maciisi_interrupt(int irq, void* arg);
static void maciisi_input(unsigned char *buf, int nb);
static int maciisi_init_via(void);
static void maciisi_poll(void);
static int maciisi_start(void);

struct adb_driver via_maciisi_driver = {
	"Mac IIsi",
	maciisi_probe,
	maciisi_init,
	maciisi_send_request,
	NULL, /* maciisi_adb_autopoll, */
	maciisi_poll,
	NULL /* maciisi_reset_adb_bus */
};

static int
maciisi_probe(void)
{
	if (macintosh_config->adb_type != MAC_ADB_IISI)
		return -ENODEV;

	via = via1;
	return 0;
}

static int
maciisi_init(void)
{
	int err;

	if (via == NULL)
		return -ENODEV;

	if ((err = maciisi_init_via())) {
		printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
		via = NULL;
		return err;
	}

	if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK | IRQ_FLG_FAST, 
			"ADB", maciisi_interrupt)) {
		printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
		return -EAGAIN;
	}

	printk("adb: Mac IIsi driver v0.2 for Unified ADB.\n");
	return 0;
}

/* Flush data from the ADB controller */
static void
maciisi_stfu(void)
{
	int status = via[B] & (TIP|TREQ);

	if (status & TREQ) {
#ifdef DEBUG_MACIISI_ADB
		printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
#endif
		return;
	}
	
	udelay(ADB_DELAY);
	via[ACR] &= ~SR_OUT;
	via[IER] = IER_CLR | SR_INT;

	udelay(ADB_DELAY);

	status = via[B] & (TIP|TREQ);

	if (!(status & TREQ))
	{
		via[B] |= TIP;

		while(1)
		{
			int poll_timeout = ADB_DELAY * 5;
			/* Poll for SR interrupt */
			while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
				status = via[B] & (TIP|TREQ);

			tmp = via[SR]; /* Clear shift register */
#ifdef DEBUG_MACIISI_ADB
			printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d data %x\n",
			       status, poll_timeout, tmp);
#endif	
			if(via[B] & TREQ)
				break;
	
			/* ACK on-off */
			via[B] |= TACK;
			udelay(ADB_DELAY);
			via[B] &= ~TACK;
		}

		/* end frame */
		via[B] &= ~TIP;
		udelay(ADB_DELAY);
	}

	via[IER] = IER_SET | SR_INT;	
}

/* All specifically VIA-related initialization goes here */
static int
maciisi_init_via(void)
{
	int	i;
	
	/* Set the lines up. We want TREQ as input TACK|TIP as output */
	via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
	/* Shift register on input */
	via[ACR]  = (via[ACR] & ~SR_CTRL) | SR_EXT;
#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
#endif
	/* Wipe any pending data and int */
	tmp = via[SR];
	/* Enable keyboard interrupts */
	via[IER] = IER_SET | SR_INT;
	/* Set initial state: idle */
	via[B] &= ~(TACK|TIP);
	/* Clear interrupt bit */
	via[IFR] = SR_INT;

	for(i = 0; i < 60; i++) {
		udelay(ADB_DELAY);
		maciisi_stfu();
		udelay(ADB_DELAY);
		if(via[B] & TREQ)
			break;
	}
	if (i == 60)
		printk(KERN_ERR "maciisi_init_via: bus jam?\n");

	maciisi_state = idle;
	need_sync = 0;

	return 0;
}

/* Send a request, possibly waiting for a reply */
static int
maciisi_send_request(struct adb_request* req, int sync)
{
	int i;

#ifdef DEBUG_MACIISI_ADB
	static int dump_packet = 0;
#endif

	if (via == NULL) {
		req->complete = 1;
		return -ENXIO;
	}

#ifdef DEBUG_MACIISI_ADB
	if (dump_packet) {
		printk(KERN_DEBUG "maciisi_send_request:");
		for (i = 0; i < req->nbytes; i++) {
			printk(" %.2x", req->data[i]);
		}
		printk(" sync %d\n", sync);
	}
#endif

	req->reply_expected = 1;
	
	i = maciisi_write(req);
	if (i)
	{
		/* Normally, if a packet requires syncing, that happens at the end of
		 * maciisi_send_request. But if the transfer fails, it will be restarted
		 * by maciisi_interrupt(). We use need_sync to tell maciisi_interrupt
		 * when to sync a packet that it sends out.
		 * 
		 * Suggestions on a better way to do this are welcome.
		 */
		if(i == -EBUSY && sync)
			need_sync = 1;
		else
			need_sync = 0;
		return i;
	}
	if(sync)
		maciisi_sync(req);
	
	return 0;
}

/* Poll the ADB chip until the request completes */
static void maciisi_sync(struct adb_request *req)
{
	int count = 0; 

#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "maciisi_sync called\n");
#endif

	/* If for some reason the ADB chip shuts up on us, we want to avoid an endless loop. */
	while (!req->complete && count++ < 50) {
		maciisi_poll();
	}
	/* This could be BAD... when the ADB controller doesn't respond
	 * for this long, it's probably not coming back :-( */
	if(count >= 50) /* Hopefully shouldn't happen */
		printk(KERN_ERR "maciisi_send_request: poll timed out!\n");
}

int
maciisi_request(struct adb_request *req, void (*done)(struct adb_request *),
	    int nbytes, ...)
{
	va_list list;
	int i;

	req->nbytes = nbytes;
	req->done = done;
	req->reply_expected = 0;
	va_start(list, nbytes);
	for (i = 0; i < nbytes; i++)
		req->data[i++] = va_arg(list, int);
	va_end(list);

	return maciisi_send_request(req, 1);
}

/* Enqueue a request, and run the queue if possible */
static int
maciisi_write(struct adb_request* req)
{
	unsigned long flags;
	int i;

	/* We will accept CUDA packets - the VIA sends them to us, so
           it figures that we should be able to send them to it */
	if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
		printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
		req->complete = 1;
		return -EINVAL;
	}
	req->next = NULL;
	req->sent = 0;
	req->complete = 0;
	req->reply_len = 0;
	
	local_irq_save(flags);

	if (current_req) {
		last_req->next = req;
		last_req = req;
	} else {
		current_req = req;
		last_req = req;
	}
	if (maciisi_state == idle)
	{
		i = maciisi_start();
		if(i != 0)
		{
			local_irq_restore(flags);
			return i;
		}
	}
	else
	{
#ifdef DEBUG_MACIISI_ADB
		printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
#endif
		local_irq_restore(flags);
		return -EBUSY;
	}

	local_irq_restore(flags);

	return 0;
}

static int
maciisi_start(void)
{
	struct adb_request* req;
	int status;

#ifdef DEBUG_MACIISI_ADB
	status = via[B] & (TIP | TREQ);

	printk(KERN_DEBUG "maciisi_start called, state=%d, status=%x, ifr=%x\n", maciisi_state, status, via[IFR]);
#endif

	if (maciisi_state != idle) {
		/* shouldn't happen */
		printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
		return -EBUSY;
	}

	req = current_req;
	if (req == NULL)
		return -EINVAL;

	status = via[B] & (TIP|TREQ);
	if (!(status & TREQ)) {
#ifdef DEBUG_MACIISI_ADB
		printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
#endif
		return -EBUSY;
	}

	/* Okay, send */
#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "maciisi_start: sending\n");
#endif
	/* Set state to active */
	via[B] |= TIP;
	/* ACK off */
	via[B] &= ~TACK;
	/* Delay */
	udelay(ADB_DELAY);
	/* Shift out and send */
	via[ACR] |= SR_OUT;
	via[SR] = req->data[0];
	data_index = 1;
	/* ACK on */
	via[B] |= TACK;
	maciisi_state = sending;

	return 0;
}

void
maciisi_poll(void)
{
	unsigned long flags;

	local_irq_save(flags);
	if (via[IFR] & SR_INT) {
		maciisi_interrupt(0, NULL, NULL);
	}
	else /* avoid calling this function too quickly in a loop */
		udelay(ADB_DELAY);

	local_irq_restore(flags);
}

/* Shift register interrupt - this is *supposed* to mean that the
   register is either full or empty. In practice, I have no idea what
   it means :( */
static irqreturn_t
maciisi_interrupt(int irq, void* arg)
{
	int status;
	struct adb_request *req;
#ifdef DEBUG_MACIISI_ADB
	static int dump_reply = 0;
#endif
	int i;
	unsigned long flags;

	local_irq_save(flags);

	status = via[B] & (TIP|TREQ);
#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
#endif

	if (!(via[IFR] & SR_INT)) {
		/* Shouldn't happen, we hope */
		printk(KERN_ERR "maciisi_interrupt: called without interrupt flag set\n");
		local_irq_restore(flags);
		return IRQ_NONE;
	}

	/* Clear the interrupt */
	/* via[IFR] = SR_INT; */

 switch_start:
	switch (maciisi_state) {
	case idle:
		if (status & TIP)
			printk(KERN_ERR "maciisi_interrupt: state is idle but TIP asserted!\n");

		if(!reading_reply)
			udelay(ADB_DELAY);
		/* Shift in */
		via[ACR] &= ~SR_OUT;
 		/* Signal start of frame */
		via[B] |= TIP;
		/* Clear the interrupt (throw this value on the floor, it's useless) */
		tmp = via[SR];
		/* ACK adb chip, high-low */
		via[B] |= TACK;
		udelay(ADB_DELAY);
		via[B] &= ~TACK;
		reply_len = 0;
		maciisi_state = reading;
		if (reading_reply) {
			reply_ptr = current_req->reply;
		} else {
			reply_ptr = maciisi_rbuf;
		}
		break;

	case sending:
		/* via[SR]; */
		/* Set ACK off */
		via[B] &= ~TACK;
		req = current_req;

		if (!(status & TREQ)) {
			/* collision */
			printk(KERN_ERR "maciisi_interrupt: send collision\n");
			/* Set idle and input */
			via[ACR] &= ~SR_OUT;
			tmp = via[SR];
			via[B] &= ~TIP;
			/* Must re-send */
			reading_reply = 0;
			reply_len = 0;
			maciisi_state = idle;
			udelay(ADB_DELAY);
			/* process this now, because the IFR has been cleared */
			goto switch_start;
		}

		udelay(ADB_DELAY);

		if (data_index >= req->nbytes) {
			/* Sent the whole packet, put the bus back in idle state */
			/* Shift in, we are about to read a reply (hopefully) */
			via[ACR] &= ~SR_OUT;
			tmp = via[SR];
			/* End of frame */
			via[B] &= ~TIP;
			req->sent = 1;
			maciisi_state = idle;
			if (req->reply_expected) {
				/* Note: only set this once we've
                                   successfully sent the packet */
				reading_reply = 1;
			} else {
				current_req = req->next;
				if (req->done)
					(*req->done)(req);
				/* Do any queued requests now */
				i = maciisi_start();
				if(i == 0 && need_sync) {
					/* Packet needs to be synced */
					maciisi_sync(current_req);
				}
				if(i != -EBUSY)
					need_sync = 0;
			}
		} else {
			/* Sending more stuff */
			/* Shift out */
			via[ACR] |= SR_OUT;
			/* Write */
			via[SR] = req->data[data_index++];
			/* Signal 'byte ready' */
			via[B] |= TACK;
		}
		break;

	case reading:
		/* Shift in */
		/* via[ACR] &= ~SR_OUT; */ /* Not in 2.2 */
		if (reply_len++ > 16) {
			printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
			via[B] |= TACK;
			udelay(ADB_DELAY);
			via[B] &= ~(TACK|TIP);
			maciisi_state = idle;
			i = maciisi_start();
			if(i == 0 && need_sync) {
				/* Packet needs to be synced */
				maciisi_sync(current_req);
			}
			if(i != -EBUSY)
				need_sync = 0;
			break;
		}
		/* Read data */
		*reply_ptr++ = via[SR];
		status = via[B] & (TIP|TREQ);
		/* ACK on/off */
		via[B] |= TACK;
		udelay(ADB_DELAY);
		via[B] &= ~TACK;	
		if (!(status & TREQ))
			break; /* more stuff to deal with */
		
		/* end of frame */
		via[B] &= ~TIP;
		tmp = via[SR]; /* That's what happens in 2.2 */
		udelay(ADB_DELAY); /* Give controller time to recover */

		/* end of packet, deal with it */
		if (reading_reply) {
			req = current_req;
			req->reply_len = reply_ptr - req->reply;
			if (req->data[0] == ADB_PACKET) {
				/* Have to adjust the reply from ADB commands */
				if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
					/* the 0x2 bit indicates no response */
					req->reply_len = 0;
				} else {
					/* leave just the command and result bytes in the reply */
					req->reply_len -= 2;
					memmove(req->reply, req->reply + 2, req->reply_len);
				}
			}
#ifdef DEBUG_MACIISI_ADB
			if (dump_reply) {
				int i;
				printk(KERN_DEBUG "maciisi_interrupt: reply is ");
				for (i = 0; i < req->reply_len; ++i)
					printk(" %.2x", req->reply[i]);
				printk("\n");
			}
#endif
			req->complete = 1;
			current_req = req->next;
			if (req->done)
				(*req->done)(req);
			/* Obviously, we got it */
			reading_reply = 0;
		} else {
			maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf);
		}
		maciisi_state = idle;
		status = via[B] & (TIP|TREQ);
		if (!(status & TREQ)) {
			/* Timeout?! More likely, another packet coming in already */
#ifdef DEBUG_MACIISI_ADB
			printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
			       status, via[IFR]);
#endif
#if 0
			udelay(ADB_DELAY);
			via[B] |= TIP;

			maciisi_state = reading;
			reading_reply = 0;
			reply_ptr = maciisi_rbuf;
#else
			/* Process the packet now */
			reading_reply = 0;
			goto switch_start;
#endif
			/* We used to do this... but the controller might actually have data for us */
			/* maciisi_stfu(); */
		}
		else {
			/* Do any queued requests now if possible */
			i = maciisi_start();
			if(i == 0 && need_sync) {
				/* Packet needs to be synced */
				maciisi_sync(current_req);
			}
			if(i != -EBUSY)
				need_sync = 0;
		}
		break;

	default:
		printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
	}
	local_irq_restore(flags);
	return IRQ_HANDLED;
}

static void
maciisi_input(unsigned char *buf, int nb)
{
#ifdef DEBUG_MACIISI_ADB
    int i;
#endif

    switch (buf[0]) {
    case ADB_PACKET:
	    adb_input(buf+2, nb-2, buf[1] & 0x40);
	    break;
    default:
#ifdef DEBUG_MACIISI_ADB
	    printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
	    for (i = 0; i < nb; ++i)
		    printk(" %.2x", buf[i]);
	    printk("\n");
#endif
	    break;
    }
}