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1/*
2 * Device driver for the via-cuda on Apple Powermacs.
3 *
4 * The VIA (versatile interface adapter) interfaces to the CUDA,
5 * a 6805 microprocessor core which controls the ADB (Apple Desktop
6 * Bus) which connects to the keyboard and mouse. The CUDA also
7 * controls system power and the RTC (real time clock) chip.
8 *
9 * Copyright (C) 1996 Paul Mackerras.
10 */
11#include <stdarg.h>
12#include <linux/types.h>
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/delay.h>
16#include <linux/adb.h>
17#include <linux/cuda.h>
18#include <linux/spinlock.h>
19#include <linux/interrupt.h>
20#ifdef CONFIG_PPC
21#include <asm/prom.h>
22#include <asm/machdep.h>
23#else
24#include <asm/macintosh.h>
25#include <asm/macints.h>
26#include <asm/mac_via.h>
27#endif
28#include <asm/io.h>
29#include <asm/system.h>
30#include <linux/init.h>
31
32static volatile unsigned char __iomem *via;
33static DEFINE_SPINLOCK(cuda_lock);
34
35/* VIA registers - spaced 0x200 bytes apart */
36#define RS 0x200 /* skip between registers */
37#define B 0 /* B-side data */
38#define A RS /* A-side data */
39#define DIRB (2*RS) /* B-side direction (1=output) */
40#define DIRA (3*RS) /* A-side direction (1=output) */
41#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
42#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
43#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
44#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
45#define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */
46#define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */
47#define SR (10*RS) /* Shift register */
48#define ACR (11*RS) /* Auxiliary control register */
49#define PCR (12*RS) /* Peripheral control register */
50#define IFR (13*RS) /* Interrupt flag register */
51#define IER (14*RS) /* Interrupt enable register */
52#define ANH (15*RS) /* A-side data, no handshake */
53
54/* Bits in B data register: all active low */
55#define TREQ 0x08 /* Transfer request (input) */
56#define TACK 0x10 /* Transfer acknowledge (output) */
57#define TIP 0x20 /* Transfer in progress (output) */
58
59/* Bits in ACR */
60#define SR_CTRL 0x1c /* Shift register control bits */
61#define SR_EXT 0x0c /* Shift on external clock */
62#define SR_OUT 0x10 /* Shift out if 1 */
63
64/* Bits in IFR and IER */
65#define IER_SET 0x80 /* set bits in IER */
66#define IER_CLR 0 /* clear bits in IER */
67#define SR_INT 0x04 /* Shift register full/empty */
68
69static enum cuda_state {
70 idle,
71 sent_first_byte,
72 sending,
73 reading,
74 read_done,
75 awaiting_reply
76} cuda_state;
77
78static struct adb_request *current_req;
79static struct adb_request *last_req;
80static unsigned char cuda_rbuf[16];
81static unsigned char *reply_ptr;
82static int reading_reply;
83static int data_index;
84static int cuda_irq;
85#ifdef CONFIG_PPC
86static struct device_node *vias;
87#endif
88static int cuda_fully_inited;
89
90#ifdef CONFIG_ADB
91static int cuda_probe(void);
92static int cuda_send_request(struct adb_request *req, int sync);
93static int cuda_adb_autopoll(int devs);
94static int cuda_reset_adb_bus(void);
95#endif /* CONFIG_ADB */
96
97static int cuda_init_via(void);
98static void cuda_start(void);
99static irqreturn_t cuda_interrupt(int irq, void *arg);
100static void cuda_input(unsigned char *buf, int nb);
101void cuda_poll(void);
102static int cuda_write(struct adb_request *req);
103
104int cuda_request(struct adb_request *req,
105 void (*done)(struct adb_request *), int nbytes, ...);
106
107#ifdef CONFIG_ADB
108struct adb_driver via_cuda_driver = {
109 .name = "CUDA",
110 .probe = cuda_probe,
111 .send_request = cuda_send_request,
112 .autopoll = cuda_adb_autopoll,
113 .poll = cuda_poll,
114 .reset_bus = cuda_reset_adb_bus,
115};
116#endif /* CONFIG_ADB */
117
118#ifdef CONFIG_MAC
119int __init find_via_cuda(void)
120{
121 struct adb_request req;
122 int err;
123
124 if (macintosh_config->adb_type != MAC_ADB_CUDA)
125 return 0;
126
127 via = via1;
128 cuda_state = idle;
129
130 err = cuda_init_via();
131 if (err) {
132 printk(KERN_ERR "cuda_init_via() failed\n");
133 via = NULL;
134 return 0;
135 }
136
137 /* enable autopoll */
138 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
139 while (!req.complete)
140 cuda_poll();
141
142 return 1;
143}
144#else
145int __init find_via_cuda(void)
146{
147 struct adb_request req;
148 phys_addr_t taddr;
149 const u32 *reg;
150 int err;
151
152 if (vias != 0)
153 return 1;
154 vias = of_find_node_by_name(NULL, "via-cuda");
155 if (vias == 0)
156 return 0;
157
158 reg = of_get_property(vias, "reg", NULL);
159 if (reg == NULL) {
160 printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
161 goto fail;
162 }
163 taddr = of_translate_address(vias, reg);
164 if (taddr == 0) {
165 printk(KERN_ERR "via-cuda: Can't translate address !\n");
166 goto fail;
167 }
168 via = ioremap(taddr, 0x2000);
169 if (via == NULL) {
170 printk(KERN_ERR "via-cuda: Can't map address !\n");
171 goto fail;
172 }
173
174 cuda_state = idle;
175 sys_ctrler = SYS_CTRLER_CUDA;
176
177 err = cuda_init_via();
178 if (err) {
179 printk(KERN_ERR "cuda_init_via() failed\n");
180 via = NULL;
181 return 0;
182 }
183
184 /* Clear and enable interrupts, but only on PPC. On 68K it's done */
185 /* for us by the main VIA driver in arch/m68k/mac/via.c */
186
187 out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */
188 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
189
190 /* enable autopoll */
191 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
192 while (!req.complete)
193 cuda_poll();
194
195 return 1;
196
197 fail:
198 of_node_put(vias);
199 vias = NULL;
200 return 0;
201}
202#endif /* !defined CONFIG_MAC */
203
204static int __init via_cuda_start(void)
205{
206 if (via == NULL)
207 return -ENODEV;
208
209#ifdef CONFIG_MAC
210 cuda_irq = IRQ_MAC_ADB;
211#else
212 cuda_irq = irq_of_parse_and_map(vias, 0);
213 if (cuda_irq == NO_IRQ) {
214 printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
215 vias->full_name);
216 return -ENODEV;
217 }
218#endif
219
220 if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
221 printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
222 return -EAGAIN;
223 }
224
225 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
226
227 cuda_fully_inited = 1;
228 return 0;
229}
230
231device_initcall(via_cuda_start);
232
233#ifdef CONFIG_ADB
234static int
235cuda_probe(void)
236{
237#ifdef CONFIG_PPC
238 if (sys_ctrler != SYS_CTRLER_CUDA)
239 return -ENODEV;
240#else
241 if (macintosh_config->adb_type != MAC_ADB_CUDA)
242 return -ENODEV;
243#endif
244 if (via == NULL)
245 return -ENODEV;
246 return 0;
247}
248#endif /* CONFIG_ADB */
249
250#define WAIT_FOR(cond, what) \
251 do { \
252 int x; \
253 for (x = 1000; !(cond); --x) { \
254 if (x == 0) { \
255 printk("Timeout waiting for " what "\n"); \
256 return -ENXIO; \
257 } \
258 udelay(100); \
259 } \
260 } while (0)
261
262static int
263cuda_init_via(void)
264{
265 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
266 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */
267 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
268 (void)in_8(&via[SR]); /* clear any left-over data */
269#ifdef CONFIG_PPC
270 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */
271 (void)in_8(&via[IER]);
272#else
273 out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */
274#endif
275
276 /* delay 4ms and then clear any pending interrupt */
277 mdelay(4);
278 (void)in_8(&via[SR]);
279 out_8(&via[IFR], SR_INT);
280
281 /* sync with the CUDA - assert TACK without TIP */
282 out_8(&via[B], in_8(&via[B]) & ~TACK);
283
284 /* wait for the CUDA to assert TREQ in response */
285 WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
286
287 /* wait for the interrupt and then clear it */
288 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
289 (void)in_8(&via[SR]);
290 out_8(&via[IFR], SR_INT);
291
292 /* finish the sync by negating TACK */
293 out_8(&via[B], in_8(&via[B]) | TACK);
294
295 /* wait for the CUDA to negate TREQ and the corresponding interrupt */
296 WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
297 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
298 (void)in_8(&via[SR]);
299 out_8(&via[IFR], SR_INT);
300 out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */
301
302 return 0;
303}
304
305#ifdef CONFIG_ADB
306/* Send an ADB command */
307static int
308cuda_send_request(struct adb_request *req, int sync)
309{
310 int i;
311
312 if ((via == NULL) || !cuda_fully_inited) {
313 req->complete = 1;
314 return -ENXIO;
315 }
316
317 req->reply_expected = 1;
318
319 i = cuda_write(req);
320 if (i)
321 return i;
322
323 if (sync) {
324 while (!req->complete)
325 cuda_poll();
326 }
327 return 0;
328}
329
330
331/* Enable/disable autopolling */
332static int
333cuda_adb_autopoll(int devs)
334{
335 struct adb_request req;
336
337 if ((via == NULL) || !cuda_fully_inited)
338 return -ENXIO;
339
340 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
341 while (!req.complete)
342 cuda_poll();
343 return 0;
344}
345
346/* Reset adb bus - how do we do this?? */
347static int
348cuda_reset_adb_bus(void)
349{
350 struct adb_request req;
351
352 if ((via == NULL) || !cuda_fully_inited)
353 return -ENXIO;
354
355 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */
356 while (!req.complete)
357 cuda_poll();
358 return 0;
359}
360#endif /* CONFIG_ADB */
361/* Construct and send a cuda request */
362int
363cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
364 int nbytes, ...)
365{
366 va_list list;
367 int i;
368
369 if (via == NULL) {
370 req->complete = 1;
371 return -ENXIO;
372 }
373
374 req->nbytes = nbytes;
375 req->done = done;
376 va_start(list, nbytes);
377 for (i = 0; i < nbytes; ++i)
378 req->data[i] = va_arg(list, int);
379 va_end(list);
380 req->reply_expected = 1;
381 return cuda_write(req);
382}
383
384static int
385cuda_write(struct adb_request *req)
386{
387 unsigned long flags;
388
389 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
390 req->complete = 1;
391 return -EINVAL;
392 }
393 req->next = NULL;
394 req->sent = 0;
395 req->complete = 0;
396 req->reply_len = 0;
397
398 spin_lock_irqsave(&cuda_lock, flags);
399 if (current_req != 0) {
400 last_req->next = req;
401 last_req = req;
402 } else {
403 current_req = req;
404 last_req = req;
405 if (cuda_state == idle)
406 cuda_start();
407 }
408 spin_unlock_irqrestore(&cuda_lock, flags);
409
410 return 0;
411}
412
413static void
414cuda_start(void)
415{
416 struct adb_request *req;
417
418 /* assert cuda_state == idle */
419 /* get the packet to send */
420 req = current_req;
421 if (req == 0)
422 return;
423 if ((in_8(&via[B]) & TREQ) == 0)
424 return; /* a byte is coming in from the CUDA */
425
426 /* set the shift register to shift out and send a byte */
427 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
428 out_8(&via[SR], req->data[0]);
429 out_8(&via[B], in_8(&via[B]) & ~TIP);
430 cuda_state = sent_first_byte;
431}
432
433void
434cuda_poll(void)
435{
436 /* cuda_interrupt only takes a normal lock, we disable
437 * interrupts here to avoid re-entering and thus deadlocking.
438 */
439 if (cuda_irq)
440 disable_irq(cuda_irq);
441 cuda_interrupt(0, NULL);
442 if (cuda_irq)
443 enable_irq(cuda_irq);
444}
445
446static irqreturn_t
447cuda_interrupt(int irq, void *arg)
448{
449 int status;
450 struct adb_request *req = NULL;
451 unsigned char ibuf[16];
452 int ibuf_len = 0;
453 int complete = 0;
454
455 spin_lock(&cuda_lock);
456
457 /* On powermacs, this handler is registered for the VIA IRQ. But they use
458 * just the shift register IRQ -- other VIA interrupt sources are disabled.
459 * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
460 * we are polling, the shift register IRQ flag has already been cleared.
461 */
462
463#ifdef CONFIG_MAC
464 if (!arg)
465#endif
466 {
467 if ((in_8(&via[IFR]) & SR_INT) == 0) {
468 spin_unlock(&cuda_lock);
469 return IRQ_NONE;
470 } else {
471 out_8(&via[IFR], SR_INT);
472 }
473 }
474
475 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
476 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
477 switch (cuda_state) {
478 case idle:
479 /* CUDA has sent us the first byte of data - unsolicited */
480 if (status != TREQ)
481 printk("cuda: state=idle, status=%x\n", status);
482 (void)in_8(&via[SR]);
483 out_8(&via[B], in_8(&via[B]) & ~TIP);
484 cuda_state = reading;
485 reply_ptr = cuda_rbuf;
486 reading_reply = 0;
487 break;
488
489 case awaiting_reply:
490 /* CUDA has sent us the first byte of data of a reply */
491 if (status != TREQ)
492 printk("cuda: state=awaiting_reply, status=%x\n", status);
493 (void)in_8(&via[SR]);
494 out_8(&via[B], in_8(&via[B]) & ~TIP);
495 cuda_state = reading;
496 reply_ptr = current_req->reply;
497 reading_reply = 1;
498 break;
499
500 case sent_first_byte:
501 if (status == TREQ + TIP + SR_OUT) {
502 /* collision */
503 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
504 (void)in_8(&via[SR]);
505 out_8(&via[B], in_8(&via[B]) | TIP | TACK);
506 cuda_state = idle;
507 } else {
508 /* assert status == TIP + SR_OUT */
509 if (status != TIP + SR_OUT)
510 printk("cuda: state=sent_first_byte status=%x\n", status);
511 out_8(&via[SR], current_req->data[1]);
512 out_8(&via[B], in_8(&via[B]) ^ TACK);
513 data_index = 2;
514 cuda_state = sending;
515 }
516 break;
517
518 case sending:
519 req = current_req;
520 if (data_index >= req->nbytes) {
521 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
522 (void)in_8(&via[SR]);
523 out_8(&via[B], in_8(&via[B]) | TACK | TIP);
524 req->sent = 1;
525 if (req->reply_expected) {
526 cuda_state = awaiting_reply;
527 } else {
528 current_req = req->next;
529 complete = 1;
530 /* not sure about this */
531 cuda_state = idle;
532 cuda_start();
533 }
534 } else {
535 out_8(&via[SR], req->data[data_index++]);
536 out_8(&via[B], in_8(&via[B]) ^ TACK);
537 }
538 break;
539
540 case reading:
541 *reply_ptr++ = in_8(&via[SR]);
542 if (status == TIP) {
543 /* that's all folks */
544 out_8(&via[B], in_8(&via[B]) | TACK | TIP);
545 cuda_state = read_done;
546 } else {
547 /* assert status == TIP | TREQ */
548 if (status != TIP + TREQ)
549 printk("cuda: state=reading status=%x\n", status);
550 out_8(&via[B], in_8(&via[B]) ^ TACK);
551 }
552 break;
553
554 case read_done:
555 (void)in_8(&via[SR]);
556 if (reading_reply) {
557 req = current_req;
558 req->reply_len = reply_ptr - req->reply;
559 if (req->data[0] == ADB_PACKET) {
560 /* Have to adjust the reply from ADB commands */
561 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
562 /* the 0x2 bit indicates no response */
563 req->reply_len = 0;
564 } else {
565 /* leave just the command and result bytes in the reply */
566 req->reply_len -= 2;
567 memmove(req->reply, req->reply + 2, req->reply_len);
568 }
569 }
570 current_req = req->next;
571 complete = 1;
572 } else {
573 /* This is tricky. We must break the spinlock to call
574 * cuda_input. However, doing so means we might get
575 * re-entered from another CPU getting an interrupt
576 * or calling cuda_poll(). I ended up using the stack
577 * (it's only for 16 bytes) and moving the actual
578 * call to cuda_input to outside of the lock.
579 */
580 ibuf_len = reply_ptr - cuda_rbuf;
581 memcpy(ibuf, cuda_rbuf, ibuf_len);
582 }
583 if (status == TREQ) {
584 out_8(&via[B], in_8(&via[B]) & ~TIP);
585 cuda_state = reading;
586 reply_ptr = cuda_rbuf;
587 reading_reply = 0;
588 } else {
589 cuda_state = idle;
590 cuda_start();
591 }
592 break;
593
594 default:
595 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
596 }
597 spin_unlock(&cuda_lock);
598 if (complete && req) {
599 void (*done)(struct adb_request *) = req->done;
600 mb();
601 req->complete = 1;
602 /* Here, we assume that if the request has a done member, the
603 * struct request will survive to setting req->complete to 1
604 */
605 if (done)
606 (*done)(req);
607 }
608 if (ibuf_len)
609 cuda_input(ibuf, ibuf_len);
610 return IRQ_HANDLED;
611}
612
613static void
614cuda_input(unsigned char *buf, int nb)
615{
616 int i;
617
618 switch (buf[0]) {
619 case ADB_PACKET:
620#ifdef CONFIG_XMON
621 if (nb == 5 && buf[2] == 0x2c) {
622 extern int xmon_wants_key, xmon_adb_keycode;
623 if (xmon_wants_key) {
624 xmon_adb_keycode = buf[3];
625 return;
626 }
627 }
628#endif /* CONFIG_XMON */
629#ifdef CONFIG_ADB
630 adb_input(buf+2, nb-2, buf[1] & 0x40);
631#endif /* CONFIG_ADB */
632 break;
633
634 default:
635 printk("data from cuda (%d bytes):", nb);
636 for (i = 0; i < nb; ++i)
637 printk(" %.2x", buf[i]);
638 printk("\n");
639 }
640}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Device driver for the Cuda and Egret system controllers found on PowerMacs
4 * and 68k Macs.
5 *
6 * The Cuda or Egret is a 6805 microcontroller interfaced to the 6522 VIA.
7 * This MCU controls system power, Parameter RAM, Real Time Clock and the
8 * Apple Desktop Bus (ADB) that connects to the keyboard and mouse.
9 *
10 * Copyright (C) 1996 Paul Mackerras.
11 */
12#include <stdarg.h>
13#include <linux/types.h>
14#include <linux/errno.h>
15#include <linux/kernel.h>
16#include <linux/delay.h>
17#include <linux/adb.h>
18#include <linux/cuda.h>
19#include <linux/spinlock.h>
20#include <linux/interrupt.h>
21#ifdef CONFIG_PPC
22#include <asm/prom.h>
23#include <asm/machdep.h>
24#else
25#include <asm/macintosh.h>
26#include <asm/macints.h>
27#include <asm/mac_via.h>
28#endif
29#include <asm/io.h>
30#include <linux/init.h>
31
32static volatile unsigned char __iomem *via;
33static DEFINE_SPINLOCK(cuda_lock);
34
35/* VIA registers - spaced 0x200 bytes apart */
36#define RS 0x200 /* skip between registers */
37#define B 0 /* B-side data */
38#define A RS /* A-side data */
39#define DIRB (2*RS) /* B-side direction (1=output) */
40#define DIRA (3*RS) /* A-side direction (1=output) */
41#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
42#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
43#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
44#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
45#define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */
46#define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */
47#define SR (10*RS) /* Shift register */
48#define ACR (11*RS) /* Auxiliary control register */
49#define PCR (12*RS) /* Peripheral control register */
50#define IFR (13*RS) /* Interrupt flag register */
51#define IER (14*RS) /* Interrupt enable register */
52#define ANH (15*RS) /* A-side data, no handshake */
53
54/*
55 * When the Cuda design replaced the Egret, some signal names and
56 * logic sense changed. They all serve the same purposes, however.
57 *
58 * VIA pin | Egret pin
59 * ----------------+------------------------------------------
60 * PB3 (input) | Transceiver session (active low)
61 * PB4 (output) | VIA full (active high)
62 * PB5 (output) | System session (active high)
63 *
64 * VIA pin | Cuda pin
65 * ----------------+------------------------------------------
66 * PB3 (input) | Transfer request (active low)
67 * PB4 (output) | Byte acknowledge (active low)
68 * PB5 (output) | Transfer in progress (active low)
69 */
70
71/* Bits in Port B data register */
72#define TREQ 0x08 /* Transfer request */
73#define TACK 0x10 /* Transfer acknowledge */
74#define TIP 0x20 /* Transfer in progress */
75
76/* Bits in ACR */
77#define SR_CTRL 0x1c /* Shift register control bits */
78#define SR_EXT 0x0c /* Shift on external clock */
79#define SR_OUT 0x10 /* Shift out if 1 */
80
81/* Bits in IFR and IER */
82#define IER_SET 0x80 /* set bits in IER */
83#define IER_CLR 0 /* clear bits in IER */
84#define SR_INT 0x04 /* Shift register full/empty */
85
86/* Duration of byte acknowledgement pulse (us) */
87#define EGRET_TACK_ASSERTED_DELAY 300
88#define EGRET_TACK_NEGATED_DELAY 400
89
90/* Interval from interrupt to start of session (us) */
91#define EGRET_SESSION_DELAY 450
92
93#ifdef CONFIG_PPC
94#define mcu_is_egret false
95#else
96static bool mcu_is_egret;
97#endif
98
99static inline bool TREQ_asserted(u8 portb)
100{
101 return !(portb & TREQ);
102}
103
104static inline void assert_TIP(void)
105{
106 if (mcu_is_egret) {
107 udelay(EGRET_SESSION_DELAY);
108 out_8(&via[B], in_8(&via[B]) | TIP);
109 } else
110 out_8(&via[B], in_8(&via[B]) & ~TIP);
111}
112
113static inline void assert_TIP_and_TACK(void)
114{
115 if (mcu_is_egret) {
116 udelay(EGRET_SESSION_DELAY);
117 out_8(&via[B], in_8(&via[B]) | TIP | TACK);
118 } else
119 out_8(&via[B], in_8(&via[B]) & ~(TIP | TACK));
120}
121
122static inline void assert_TACK(void)
123{
124 if (mcu_is_egret) {
125 udelay(EGRET_TACK_NEGATED_DELAY);
126 out_8(&via[B], in_8(&via[B]) | TACK);
127 } else
128 out_8(&via[B], in_8(&via[B]) & ~TACK);
129}
130
131static inline void toggle_TACK(void)
132{
133 out_8(&via[B], in_8(&via[B]) ^ TACK);
134}
135
136static inline void negate_TACK(void)
137{
138 if (mcu_is_egret) {
139 udelay(EGRET_TACK_ASSERTED_DELAY);
140 out_8(&via[B], in_8(&via[B]) & ~TACK);
141 } else
142 out_8(&via[B], in_8(&via[B]) | TACK);
143}
144
145static inline void negate_TIP_and_TACK(void)
146{
147 if (mcu_is_egret) {
148 udelay(EGRET_TACK_ASSERTED_DELAY);
149 out_8(&via[B], in_8(&via[B]) & ~(TIP | TACK));
150 } else
151 out_8(&via[B], in_8(&via[B]) | TIP | TACK);
152}
153
154static enum cuda_state {
155 idle,
156 sent_first_byte,
157 sending,
158 reading,
159 read_done,
160 awaiting_reply
161} cuda_state;
162
163static struct adb_request *current_req;
164static struct adb_request *last_req;
165static unsigned char cuda_rbuf[16];
166static unsigned char *reply_ptr;
167static int reading_reply;
168static int data_index;
169static int cuda_irq;
170#ifdef CONFIG_PPC
171static struct device_node *vias;
172#endif
173static int cuda_fully_inited;
174
175#ifdef CONFIG_ADB
176static int cuda_probe(void);
177static int cuda_send_request(struct adb_request *req, int sync);
178static int cuda_adb_autopoll(int devs);
179static int cuda_reset_adb_bus(void);
180#endif /* CONFIG_ADB */
181
182static int cuda_init_via(void);
183static void cuda_start(void);
184static irqreturn_t cuda_interrupt(int irq, void *arg);
185static void cuda_input(unsigned char *buf, int nb);
186void cuda_poll(void);
187static int cuda_write(struct adb_request *req);
188
189int cuda_request(struct adb_request *req,
190 void (*done)(struct adb_request *), int nbytes, ...);
191
192#ifdef CONFIG_ADB
193struct adb_driver via_cuda_driver = {
194 .name = "CUDA",
195 .probe = cuda_probe,
196 .send_request = cuda_send_request,
197 .autopoll = cuda_adb_autopoll,
198 .poll = cuda_poll,
199 .reset_bus = cuda_reset_adb_bus,
200};
201#endif /* CONFIG_ADB */
202
203#ifdef CONFIG_MAC
204int __init find_via_cuda(void)
205{
206 struct adb_request req;
207 int err;
208
209 if (macintosh_config->adb_type != MAC_ADB_CUDA &&
210 macintosh_config->adb_type != MAC_ADB_EGRET)
211 return 0;
212
213 via = via1;
214 cuda_state = idle;
215 mcu_is_egret = macintosh_config->adb_type == MAC_ADB_EGRET;
216
217 err = cuda_init_via();
218 if (err) {
219 printk(KERN_ERR "cuda_init_via() failed\n");
220 via = NULL;
221 return 0;
222 }
223
224 /* enable autopoll */
225 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
226 while (!req.complete)
227 cuda_poll();
228
229 return 1;
230}
231#else
232int __init find_via_cuda(void)
233{
234 struct adb_request req;
235 phys_addr_t taddr;
236 const u32 *reg;
237 int err;
238
239 if (vias != 0)
240 return 1;
241 vias = of_find_node_by_name(NULL, "via-cuda");
242 if (vias == 0)
243 return 0;
244
245 reg = of_get_property(vias, "reg", NULL);
246 if (reg == NULL) {
247 printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
248 goto fail;
249 }
250 taddr = of_translate_address(vias, reg);
251 if (taddr == 0) {
252 printk(KERN_ERR "via-cuda: Can't translate address !\n");
253 goto fail;
254 }
255 via = ioremap(taddr, 0x2000);
256 if (via == NULL) {
257 printk(KERN_ERR "via-cuda: Can't map address !\n");
258 goto fail;
259 }
260
261 cuda_state = idle;
262 sys_ctrler = SYS_CTRLER_CUDA;
263
264 err = cuda_init_via();
265 if (err) {
266 printk(KERN_ERR "cuda_init_via() failed\n");
267 via = NULL;
268 return 0;
269 }
270
271 /* Clear and enable interrupts, but only on PPC. On 68K it's done */
272 /* for us by the main VIA driver in arch/m68k/mac/via.c */
273
274 out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */
275 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
276
277 /* enable autopoll */
278 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
279 while (!req.complete)
280 cuda_poll();
281
282 return 1;
283
284 fail:
285 of_node_put(vias);
286 vias = NULL;
287 return 0;
288}
289#endif /* !defined CONFIG_MAC */
290
291static int __init via_cuda_start(void)
292{
293 if (via == NULL)
294 return -ENODEV;
295
296#ifdef CONFIG_MAC
297 cuda_irq = IRQ_MAC_ADB;
298#else
299 cuda_irq = irq_of_parse_and_map(vias, 0);
300 if (!cuda_irq) {
301 printk(KERN_ERR "via-cuda: can't map interrupts for %pOF\n",
302 vias);
303 return -ENODEV;
304 }
305#endif
306
307 if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
308 printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
309 return -EAGAIN;
310 }
311
312 pr_info("Macintosh Cuda and Egret driver.\n");
313
314 cuda_fully_inited = 1;
315 return 0;
316}
317
318device_initcall(via_cuda_start);
319
320#ifdef CONFIG_ADB
321static int
322cuda_probe(void)
323{
324#ifdef CONFIG_PPC
325 if (sys_ctrler != SYS_CTRLER_CUDA)
326 return -ENODEV;
327#else
328 if (macintosh_config->adb_type != MAC_ADB_CUDA &&
329 macintosh_config->adb_type != MAC_ADB_EGRET)
330 return -ENODEV;
331#endif
332 if (via == NULL)
333 return -ENODEV;
334 return 0;
335}
336#endif /* CONFIG_ADB */
337
338static int __init sync_egret(void)
339{
340 if (TREQ_asserted(in_8(&via[B]))) {
341 /* Complete the inbound transfer */
342 assert_TIP_and_TACK();
343 while (1) {
344 negate_TACK();
345 mdelay(1);
346 (void)in_8(&via[SR]);
347 assert_TACK();
348 if (!TREQ_asserted(in_8(&via[B])))
349 break;
350 }
351 negate_TIP_and_TACK();
352 } else if (in_8(&via[B]) & TIP) {
353 /* Terminate the outbound transfer */
354 negate_TACK();
355 assert_TACK();
356 mdelay(1);
357 negate_TIP_and_TACK();
358 }
359 /* Clear shift register interrupt */
360 if (in_8(&via[IFR]) & SR_INT)
361 (void)in_8(&via[SR]);
362 return 0;
363}
364
365#define WAIT_FOR(cond, what) \
366 do { \
367 int x; \
368 for (x = 1000; !(cond); --x) { \
369 if (x == 0) { \
370 pr_err("Timeout waiting for " what "\n"); \
371 return -ENXIO; \
372 } \
373 udelay(100); \
374 } \
375 } while (0)
376
377static int
378__init cuda_init_via(void)
379{
380#ifdef CONFIG_PPC
381 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */
382 (void)in_8(&via[IER]);
383#else
384 out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */
385#endif
386
387 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
388 out_8(&via[ACR], (in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
389 (void)in_8(&via[SR]); /* clear any left-over data */
390
391 if (mcu_is_egret)
392 return sync_egret();
393
394 negate_TIP_and_TACK();
395
396 /* delay 4ms and then clear any pending interrupt */
397 mdelay(4);
398 (void)in_8(&via[SR]);
399 out_8(&via[IFR], SR_INT);
400
401 /* sync with the CUDA - assert TACK without TIP */
402 assert_TACK();
403
404 /* wait for the CUDA to assert TREQ in response */
405 WAIT_FOR(TREQ_asserted(in_8(&via[B])), "CUDA response to sync");
406
407 /* wait for the interrupt and then clear it */
408 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
409 (void)in_8(&via[SR]);
410 out_8(&via[IFR], SR_INT);
411
412 /* finish the sync by negating TACK */
413 negate_TACK();
414
415 /* wait for the CUDA to negate TREQ and the corresponding interrupt */
416 WAIT_FOR(!TREQ_asserted(in_8(&via[B])), "CUDA response to sync (3)");
417 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
418 (void)in_8(&via[SR]);
419 out_8(&via[IFR], SR_INT);
420
421 return 0;
422}
423
424#ifdef CONFIG_ADB
425/* Send an ADB command */
426static int
427cuda_send_request(struct adb_request *req, int sync)
428{
429 int i;
430
431 if ((via == NULL) || !cuda_fully_inited) {
432 req->complete = 1;
433 return -ENXIO;
434 }
435
436 req->reply_expected = 1;
437
438 i = cuda_write(req);
439 if (i)
440 return i;
441
442 if (sync) {
443 while (!req->complete)
444 cuda_poll();
445 }
446 return 0;
447}
448
449
450/* Enable/disable autopolling */
451static int
452cuda_adb_autopoll(int devs)
453{
454 struct adb_request req;
455
456 if ((via == NULL) || !cuda_fully_inited)
457 return -ENXIO;
458
459 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
460 while (!req.complete)
461 cuda_poll();
462 return 0;
463}
464
465/* Reset adb bus - how do we do this?? */
466static int
467cuda_reset_adb_bus(void)
468{
469 struct adb_request req;
470
471 if ((via == NULL) || !cuda_fully_inited)
472 return -ENXIO;
473
474 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */
475 while (!req.complete)
476 cuda_poll();
477 return 0;
478}
479#endif /* CONFIG_ADB */
480
481/* Construct and send a cuda request */
482int
483cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
484 int nbytes, ...)
485{
486 va_list list;
487 int i;
488
489 if (via == NULL) {
490 req->complete = 1;
491 return -ENXIO;
492 }
493
494 req->nbytes = nbytes;
495 req->done = done;
496 va_start(list, nbytes);
497 for (i = 0; i < nbytes; ++i)
498 req->data[i] = va_arg(list, int);
499 va_end(list);
500 req->reply_expected = 1;
501 return cuda_write(req);
502}
503EXPORT_SYMBOL(cuda_request);
504
505static int
506cuda_write(struct adb_request *req)
507{
508 unsigned long flags;
509
510 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
511 req->complete = 1;
512 return -EINVAL;
513 }
514 req->next = NULL;
515 req->sent = 0;
516 req->complete = 0;
517 req->reply_len = 0;
518
519 spin_lock_irqsave(&cuda_lock, flags);
520 if (current_req != 0) {
521 last_req->next = req;
522 last_req = req;
523 } else {
524 current_req = req;
525 last_req = req;
526 if (cuda_state == idle)
527 cuda_start();
528 }
529 spin_unlock_irqrestore(&cuda_lock, flags);
530
531 return 0;
532}
533
534static void
535cuda_start(void)
536{
537 /* assert cuda_state == idle */
538 if (current_req == NULL)
539 return;
540 data_index = 0;
541 if (TREQ_asserted(in_8(&via[B])))
542 return; /* a byte is coming in from the CUDA */
543
544 /* set the shift register to shift out and send a byte */
545 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
546 out_8(&via[SR], current_req->data[data_index++]);
547 if (mcu_is_egret)
548 assert_TIP_and_TACK();
549 else
550 assert_TIP();
551 cuda_state = sent_first_byte;
552}
553
554void
555cuda_poll(void)
556{
557 cuda_interrupt(0, NULL);
558}
559EXPORT_SYMBOL(cuda_poll);
560
561#define ARRAY_FULL(a, p) ((p) - (a) == ARRAY_SIZE(a))
562
563static irqreturn_t
564cuda_interrupt(int irq, void *arg)
565{
566 unsigned long flags;
567 u8 status;
568 struct adb_request *req = NULL;
569 unsigned char ibuf[16];
570 int ibuf_len = 0;
571 int complete = 0;
572 bool full;
573
574 spin_lock_irqsave(&cuda_lock, flags);
575
576 /* On powermacs, this handler is registered for the VIA IRQ. But they use
577 * just the shift register IRQ -- other VIA interrupt sources are disabled.
578 * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
579 * we are polling, the shift register IRQ flag has already been cleared.
580 */
581
582#ifdef CONFIG_MAC
583 if (!arg)
584#endif
585 {
586 if ((in_8(&via[IFR]) & SR_INT) == 0) {
587 spin_unlock_irqrestore(&cuda_lock, flags);
588 return IRQ_NONE;
589 } else {
590 out_8(&via[IFR], SR_INT);
591 }
592 }
593
594 status = in_8(&via[B]) & (TIP | TACK | TREQ);
595
596 switch (cuda_state) {
597 case idle:
598 /* System controller has unsolicited data for us */
599 (void)in_8(&via[SR]);
600idle_state:
601 assert_TIP();
602 cuda_state = reading;
603 reply_ptr = cuda_rbuf;
604 reading_reply = 0;
605 break;
606
607 case awaiting_reply:
608 /* System controller has reply data for us */
609 (void)in_8(&via[SR]);
610 assert_TIP();
611 cuda_state = reading;
612 reply_ptr = current_req->reply;
613 reading_reply = 1;
614 break;
615
616 case sent_first_byte:
617 if (TREQ_asserted(status)) {
618 /* collision */
619 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
620 (void)in_8(&via[SR]);
621 negate_TIP_and_TACK();
622 cuda_state = idle;
623 /* Egret does not raise an "aborted" interrupt */
624 if (mcu_is_egret)
625 goto idle_state;
626 } else {
627 out_8(&via[SR], current_req->data[data_index++]);
628 toggle_TACK();
629 if (mcu_is_egret)
630 assert_TACK();
631 cuda_state = sending;
632 }
633 break;
634
635 case sending:
636 req = current_req;
637 if (data_index >= req->nbytes) {
638 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
639 (void)in_8(&via[SR]);
640 negate_TIP_and_TACK();
641 req->sent = 1;
642 if (req->reply_expected) {
643 cuda_state = awaiting_reply;
644 } else {
645 current_req = req->next;
646 complete = 1;
647 /* not sure about this */
648 cuda_state = idle;
649 cuda_start();
650 }
651 } else {
652 out_8(&via[SR], req->data[data_index++]);
653 toggle_TACK();
654 if (mcu_is_egret)
655 assert_TACK();
656 }
657 break;
658
659 case reading:
660 full = reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr)
661 : ARRAY_FULL(cuda_rbuf, reply_ptr);
662 if (full)
663 (void)in_8(&via[SR]);
664 else
665 *reply_ptr++ = in_8(&via[SR]);
666 if (!TREQ_asserted(status) || full) {
667 if (mcu_is_egret)
668 assert_TACK();
669 /* that's all folks */
670 negate_TIP_and_TACK();
671 cuda_state = read_done;
672 /* Egret does not raise a "read done" interrupt */
673 if (mcu_is_egret)
674 goto read_done_state;
675 } else {
676 toggle_TACK();
677 if (mcu_is_egret)
678 negate_TACK();
679 }
680 break;
681
682 case read_done:
683 (void)in_8(&via[SR]);
684read_done_state:
685 if (reading_reply) {
686 req = current_req;
687 req->reply_len = reply_ptr - req->reply;
688 if (req->data[0] == ADB_PACKET) {
689 /* Have to adjust the reply from ADB commands */
690 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
691 /* the 0x2 bit indicates no response */
692 req->reply_len = 0;
693 } else {
694 /* leave just the command and result bytes in the reply */
695 req->reply_len -= 2;
696 memmove(req->reply, req->reply + 2, req->reply_len);
697 }
698 }
699 current_req = req->next;
700 complete = 1;
701 reading_reply = 0;
702 } else {
703 /* This is tricky. We must break the spinlock to call
704 * cuda_input. However, doing so means we might get
705 * re-entered from another CPU getting an interrupt
706 * or calling cuda_poll(). I ended up using the stack
707 * (it's only for 16 bytes) and moving the actual
708 * call to cuda_input to outside of the lock.
709 */
710 ibuf_len = reply_ptr - cuda_rbuf;
711 memcpy(ibuf, cuda_rbuf, ibuf_len);
712 }
713 reply_ptr = cuda_rbuf;
714 cuda_state = idle;
715 cuda_start();
716 if (cuda_state == idle && TREQ_asserted(in_8(&via[B]))) {
717 assert_TIP();
718 cuda_state = reading;
719 }
720 break;
721
722 default:
723 pr_err("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
724 }
725 spin_unlock_irqrestore(&cuda_lock, flags);
726 if (complete && req) {
727 void (*done)(struct adb_request *) = req->done;
728 mb();
729 req->complete = 1;
730 /* Here, we assume that if the request has a done member, the
731 * struct request will survive to setting req->complete to 1
732 */
733 if (done)
734 (*done)(req);
735 }
736 if (ibuf_len)
737 cuda_input(ibuf, ibuf_len);
738 return IRQ_HANDLED;
739}
740
741static void
742cuda_input(unsigned char *buf, int nb)
743{
744 switch (buf[0]) {
745 case ADB_PACKET:
746#ifdef CONFIG_XMON
747 if (nb == 5 && buf[2] == 0x2c) {
748 extern int xmon_wants_key, xmon_adb_keycode;
749 if (xmon_wants_key) {
750 xmon_adb_keycode = buf[3];
751 return;
752 }
753 }
754#endif /* CONFIG_XMON */
755#ifdef CONFIG_ADB
756 adb_input(buf+2, nb-2, buf[1] & 0x40);
757#endif /* CONFIG_ADB */
758 break;
759
760 case TIMER_PACKET:
761 /* Egret sends these periodically. Might be useful as a 'heartbeat'
762 * to trigger a recovery for the VIA shift register errata.
763 */
764 break;
765
766 default:
767 print_hex_dump(KERN_INFO, "cuda_input: ", DUMP_PREFIX_NONE, 32, 1,
768 buf, nb, false);
769 }
770}
771
772/* Offset between Unix time (1970-based) and Mac time (1904-based) */
773#define RTC_OFFSET 2082844800
774
775time64_t cuda_get_time(void)
776{
777 struct adb_request req;
778 u32 now;
779
780 if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
781 return 0;
782 while (!req.complete)
783 cuda_poll();
784 if (req.reply_len != 7)
785 pr_err("%s: got %d byte reply\n", __func__, req.reply_len);
786 now = (req.reply[3] << 24) + (req.reply[4] << 16) +
787 (req.reply[5] << 8) + req.reply[6];
788 return (time64_t)now - RTC_OFFSET;
789}
790
791int cuda_set_rtc_time(struct rtc_time *tm)
792{
793 u32 now;
794 struct adb_request req;
795
796 now = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET);
797 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
798 now >> 24, now >> 16, now >> 8, now) < 0)
799 return -ENXIO;
800 while (!req.complete)
801 cuda_poll();
802 if ((req.reply_len != 3) && (req.reply_len != 7))
803 pr_err("%s: got %d byte reply\n", __func__, req.reply_len);
804 return 0;
805}