2 * Device driver for the via-cuda on Apple Powermacs.
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.
9 * Copyright (C) 1996 Paul Mackerras.
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/sched.h>
17 #include <linux/adb.h>
18 #include <linux/cuda.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
23 #include <asm/machdep.h>
25 #include <asm/macintosh.h>
26 #include <asm/macints.h>
27 #include <asm/machw.h>
28 #include <asm/mac_via.h>
31 #include <asm/system.h>
32 #include <linux/init.h>
34 static volatile unsigned char __iomem *via;
35 static DEFINE_SPINLOCK(cuda_lock);
38 #define CUDA_IRQ IRQ_MAC_ADB
41 #define CUDA_IRQ vias->intrs[0].line
44 /* VIA registers - spaced 0x200 bytes apart */
45 #define RS 0x200 /* skip between registers */
46 #define B 0 /* B-side data */
47 #define A RS /* A-side data */
48 #define DIRB (2*RS) /* B-side direction (1=output) */
49 #define DIRA (3*RS) /* A-side direction (1=output) */
50 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
51 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
52 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
53 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
54 #define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */
55 #define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */
56 #define SR (10*RS) /* Shift register */
57 #define ACR (11*RS) /* Auxiliary control register */
58 #define PCR (12*RS) /* Peripheral control register */
59 #define IFR (13*RS) /* Interrupt flag register */
60 #define IER (14*RS) /* Interrupt enable register */
61 #define ANH (15*RS) /* A-side data, no handshake */
63 /* Bits in B data register: all active low */
64 #define TREQ 0x08 /* Transfer request (input) */
65 #define TACK 0x10 /* Transfer acknowledge (output) */
66 #define TIP 0x20 /* Transfer in progress (output) */
69 #define SR_CTRL 0x1c /* Shift register control bits */
70 #define SR_EXT 0x0c /* Shift on external clock */
71 #define SR_OUT 0x10 /* Shift out if 1 */
73 /* Bits in IFR and IER */
74 #define IER_SET 0x80 /* set bits in IER */
75 #define IER_CLR 0 /* clear bits in IER */
76 #define SR_INT 0x04 /* Shift register full/empty */
78 static enum cuda_state {
87 static struct adb_request *current_req;
88 static struct adb_request *last_req;
89 static unsigned char cuda_rbuf[16];
90 static unsigned char *reply_ptr;
91 static int reading_reply;
92 static int data_index;
94 static struct device_node *vias;
96 static int cuda_fully_inited = 0;
99 static int cuda_probe(void);
100 static int cuda_init(void);
101 static int cuda_send_request(struct adb_request *req, int sync);
102 static int cuda_adb_autopoll(int devs);
103 static int cuda_reset_adb_bus(void);
104 #endif /* CONFIG_ADB */
106 static int cuda_init_via(void);
107 static void cuda_start(void);
108 static irqreturn_t cuda_interrupt(int irq, void *arg, struct pt_regs *regs);
109 static void cuda_input(unsigned char *buf, int nb, struct pt_regs *regs);
110 void cuda_poll(void);
111 static int cuda_write(struct adb_request *req);
113 int cuda_request(struct adb_request *req,
114 void (*done)(struct adb_request *), int nbytes, ...);
117 struct adb_driver via_cuda_driver = {
126 #endif /* CONFIG_ADB */
129 int __init find_via_cuda(void)
131 struct adb_request req;
138 vias = of_find_node_by_name(NULL, "via-cuda");
142 reg = (u32 *)get_property(vias, "reg", NULL);
144 printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
147 taddr = of_translate_address(vias, reg);
149 printk(KERN_ERR "via-cuda: Can't translate address !\n");
152 via = ioremap(taddr, 0x2000);
154 printk(KERN_ERR "via-cuda: Can't map address !\n");
159 sys_ctrler = SYS_CTRLER_CUDA;
161 err = cuda_init_via();
163 printk(KERN_ERR "cuda_init_via() failed\n");
168 /* Clear and enable interrupts, but only on PPC. On 68K it's done */
169 /* for us by the main VIA driver in arch/m68k/mac/via.c */
172 out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */
173 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
176 /* enable autopoll */
177 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
178 while (!req.complete)
188 #endif /* CONFIG_PPC */
190 static int __init via_cuda_start(void)
195 if (request_irq(CUDA_IRQ, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
196 printk(KERN_ERR "cuda_init: can't get irq %d\n", CUDA_IRQ);
200 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
202 cuda_fully_inited = 1;
206 device_initcall(via_cuda_start);
213 if (sys_ctrler != SYS_CTRLER_CUDA)
216 if (macintosh_config->adb_type != MAC_ADB_CUDA)
231 int err = cuda_init_via();
233 printk(KERN_ERR "cuda_init_via() failed\n");
237 return via_cuda_start();
240 #endif /* CONFIG_ADB */
242 #define WAIT_FOR(cond, what) \
245 for (x = 1000; !(cond); --x) { \
247 printk("Timeout waiting for " what "\n"); \
257 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
258 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */
259 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
260 (void)in_8(&via[SR]); /* clear any left-over data */
262 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */
263 (void)in_8(&via[IER]);
266 /* delay 4ms and then clear any pending interrupt */
268 (void)in_8(&via[SR]);
269 out_8(&via[IFR], in_8(&via[IFR]) & 0x7f);
271 /* sync with the CUDA - assert TACK without TIP */
272 out_8(&via[B], in_8(&via[B]) & ~TACK);
274 /* wait for the CUDA to assert TREQ in response */
275 WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
277 /* wait for the interrupt and then clear it */
278 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
279 (void)in_8(&via[SR]);
280 out_8(&via[IFR], in_8(&via[IFR]) & 0x7f);
282 /* finish the sync by negating TACK */
283 out_8(&via[B], in_8(&via[B]) | TACK);
285 /* wait for the CUDA to negate TREQ and the corresponding interrupt */
286 WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
287 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
288 (void)in_8(&via[SR]);
289 out_8(&via[IFR], in_8(&via[IFR]) & 0x7f);
290 out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */
296 /* Send an ADB command */
298 cuda_send_request(struct adb_request *req, int sync)
302 if ((via == NULL) || !cuda_fully_inited) {
307 req->reply_expected = 1;
314 while (!req->complete)
321 /* Enable/disable autopolling */
323 cuda_adb_autopoll(int devs)
325 struct adb_request req;
327 if ((via == NULL) || !cuda_fully_inited)
330 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
331 while (!req.complete)
336 /* Reset adb bus - how do we do this?? */
338 cuda_reset_adb_bus(void)
340 struct adb_request req;
342 if ((via == NULL) || !cuda_fully_inited)
345 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */
346 while (!req.complete)
350 #endif /* CONFIG_ADB */
351 /* Construct and send a cuda request */
353 cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
364 req->nbytes = nbytes;
366 va_start(list, nbytes);
367 for (i = 0; i < nbytes; ++i)
368 req->data[i] = va_arg(list, int);
370 req->reply_expected = 1;
371 return cuda_write(req);
375 cuda_write(struct adb_request *req)
379 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
388 spin_lock_irqsave(&cuda_lock, flags);
389 if (current_req != 0) {
390 last_req->next = req;
395 if (cuda_state == idle)
398 spin_unlock_irqrestore(&cuda_lock, flags);
406 struct adb_request *req;
408 /* assert cuda_state == idle */
409 /* get the packet to send */
413 if ((in_8(&via[B]) & TREQ) == 0)
414 return; /* a byte is coming in from the CUDA */
416 /* set the shift register to shift out and send a byte */
417 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
418 out_8(&via[SR], req->data[0]);
419 out_8(&via[B], in_8(&via[B]) & ~TIP);
420 cuda_state = sent_first_byte;
428 /* cuda_interrupt only takes a normal lock, we disable
429 * interrupts here to avoid re-entering and thus deadlocking.
430 * An option would be to disable only the IRQ source with
431 * disable_irq(), would that work on m68k ? --BenH
433 local_irq_save(flags);
434 cuda_interrupt(0, NULL, NULL);
435 local_irq_restore(flags);
439 cuda_interrupt(int irq, void *arg, struct pt_regs *regs)
442 struct adb_request *req = NULL;
443 unsigned char ibuf[16];
448 spin_lock(&cuda_lock);
450 virq = in_8(&via[IFR]) & 0x7f;
451 out_8(&via[IFR], virq);
452 if ((virq & SR_INT) == 0) {
453 spin_unlock(&cuda_lock);
457 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
458 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
459 switch (cuda_state) {
461 /* CUDA has sent us the first byte of data - unsolicited */
463 printk("cuda: state=idle, status=%x\n", status);
464 (void)in_8(&via[SR]);
465 out_8(&via[B], in_8(&via[B]) & ~TIP);
466 cuda_state = reading;
467 reply_ptr = cuda_rbuf;
472 /* CUDA has sent us the first byte of data of a reply */
474 printk("cuda: state=awaiting_reply, status=%x\n", status);
475 (void)in_8(&via[SR]);
476 out_8(&via[B], in_8(&via[B]) & ~TIP);
477 cuda_state = reading;
478 reply_ptr = current_req->reply;
482 case sent_first_byte:
483 if (status == TREQ + TIP + SR_OUT) {
485 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
486 (void)in_8(&via[SR]);
487 out_8(&via[B], in_8(&via[B]) | TIP | TACK);
490 /* assert status == TIP + SR_OUT */
491 if (status != TIP + SR_OUT)
492 printk("cuda: state=sent_first_byte status=%x\n", status);
493 out_8(&via[SR], current_req->data[1]);
494 out_8(&via[B], in_8(&via[B]) ^ TACK);
496 cuda_state = sending;
502 if (data_index >= req->nbytes) {
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]) | TACK | TIP);
507 if (req->reply_expected) {
508 cuda_state = awaiting_reply;
510 current_req = req->next;
512 /* not sure about this */
517 out_8(&via[SR], req->data[data_index++]);
518 out_8(&via[B], in_8(&via[B]) ^ TACK);
523 *reply_ptr++ = in_8(&via[SR]);
525 /* that's all folks */
526 out_8(&via[B], in_8(&via[B]) | TACK | TIP);
527 cuda_state = read_done;
529 /* assert status == TIP | TREQ */
530 if (status != TIP + TREQ)
531 printk("cuda: state=reading status=%x\n", status);
532 out_8(&via[B], in_8(&via[B]) ^ TACK);
537 (void)in_8(&via[SR]);
540 req->reply_len = reply_ptr - req->reply;
541 if (req->data[0] == ADB_PACKET) {
542 /* Have to adjust the reply from ADB commands */
543 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
544 /* the 0x2 bit indicates no response */
547 /* leave just the command and result bytes in the reply */
549 memmove(req->reply, req->reply + 2, req->reply_len);
552 current_req = req->next;
555 /* This is tricky. We must break the spinlock to call
556 * cuda_input. However, doing so means we might get
557 * re-entered from another CPU getting an interrupt
558 * or calling cuda_poll(). I ended up using the stack
559 * (it's only for 16 bytes) and moving the actual
560 * call to cuda_input to outside of the lock.
562 ibuf_len = reply_ptr - cuda_rbuf;
563 memcpy(ibuf, cuda_rbuf, ibuf_len);
565 if (status == TREQ) {
566 out_8(&via[B], in_8(&via[B]) & ~TIP);
567 cuda_state = reading;
568 reply_ptr = cuda_rbuf;
577 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
579 spin_unlock(&cuda_lock);
580 if (complete && req) {
581 void (*done)(struct adb_request *) = req->done;
584 /* Here, we assume that if the request has a done member, the
585 * struct request will survive to setting req->complete to 1
591 cuda_input(ibuf, ibuf_len, regs);
596 cuda_input(unsigned char *buf, int nb, struct pt_regs *regs)
603 if (nb == 5 && buf[2] == 0x2c) {
604 extern int xmon_wants_key, xmon_adb_keycode;
605 if (xmon_wants_key) {
606 xmon_adb_keycode = buf[3];
610 #endif /* CONFIG_XMON */
612 adb_input(buf+2, nb-2, regs, buf[1] & 0x40);
613 #endif /* CONFIG_ADB */
617 printk("data from cuda (%d bytes):", nb);
618 for (i = 0; i < nb; ++i)
619 printk(" %.2x", buf[i]);