1 // SPDX-License-Identifier: GPL-2.0
3 * Device driver for the Cuda and Egret system controllers found on PowerMacs
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.
10 * Copyright (C) 1996 Paul Mackerras.
12 #include <linux/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 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
25 #include <asm/machdep.h>
26 #include <asm/pmac_feature.h>
28 #include <asm/macintosh.h>
29 #include <asm/macints.h>
30 #include <asm/mac_via.h>
33 #include <linux/init.h>
35 static volatile unsigned char __iomem
*via
;
36 static DEFINE_SPINLOCK(cuda_lock
);
38 /* VIA registers - spaced 0x200 bytes apart */
39 #define RS 0x200 /* skip between registers */
40 #define B 0 /* B-side data */
41 #define A RS /* A-side data */
42 #define DIRB (2*RS) /* B-side direction (1=output) */
43 #define DIRA (3*RS) /* A-side direction (1=output) */
44 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
45 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
46 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
47 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
48 #define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */
49 #define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */
50 #define SR (10*RS) /* Shift register */
51 #define ACR (11*RS) /* Auxiliary control register */
52 #define PCR (12*RS) /* Peripheral control register */
53 #define IFR (13*RS) /* Interrupt flag register */
54 #define IER (14*RS) /* Interrupt enable register */
55 #define ANH (15*RS) /* A-side data, no handshake */
58 * When the Cuda design replaced the Egret, some signal names and
59 * logic sense changed. They all serve the same purposes, however.
62 * ----------------+------------------------------------------
63 * PB3 (input) | Transceiver session (active low)
64 * PB4 (output) | VIA full (active high)
65 * PB5 (output) | System session (active high)
68 * ----------------+------------------------------------------
69 * PB3 (input) | Transfer request (active low)
70 * PB4 (output) | Byte acknowledge (active low)
71 * PB5 (output) | Transfer in progress (active low)
74 /* Bits in Port B data register */
75 #define TREQ 0x08 /* Transfer request */
76 #define TACK 0x10 /* Transfer acknowledge */
77 #define TIP 0x20 /* Transfer in progress */
80 #define SR_CTRL 0x1c /* Shift register control bits */
81 #define SR_EXT 0x0c /* Shift on external clock */
82 #define SR_OUT 0x10 /* Shift out if 1 */
84 /* Bits in IFR and IER */
85 #define IER_SET 0x80 /* set bits in IER */
86 #define IER_CLR 0 /* clear bits in IER */
87 #define SR_INT 0x04 /* Shift register full/empty */
89 /* Duration of byte acknowledgement pulse (us) */
90 #define EGRET_TACK_ASSERTED_DELAY 300
91 #define EGRET_TACK_NEGATED_DELAY 400
93 /* Interval from interrupt to start of session (us) */
94 #define EGRET_SESSION_DELAY 450
97 #define mcu_is_egret false
99 static bool mcu_is_egret
;
102 static inline bool TREQ_asserted(u8 portb
)
104 return !(portb
& TREQ
);
107 static inline void assert_TIP(void)
110 udelay(EGRET_SESSION_DELAY
);
111 out_8(&via
[B
], in_8(&via
[B
]) | TIP
);
113 out_8(&via
[B
], in_8(&via
[B
]) & ~TIP
);
116 static inline void assert_TIP_and_TACK(void)
119 udelay(EGRET_SESSION_DELAY
);
120 out_8(&via
[B
], in_8(&via
[B
]) | TIP
| TACK
);
122 out_8(&via
[B
], in_8(&via
[B
]) & ~(TIP
| TACK
));
125 static inline void assert_TACK(void)
128 udelay(EGRET_TACK_NEGATED_DELAY
);
129 out_8(&via
[B
], in_8(&via
[B
]) | TACK
);
131 out_8(&via
[B
], in_8(&via
[B
]) & ~TACK
);
134 static inline void toggle_TACK(void)
136 out_8(&via
[B
], in_8(&via
[B
]) ^ TACK
);
139 static inline void negate_TACK(void)
142 udelay(EGRET_TACK_ASSERTED_DELAY
);
143 out_8(&via
[B
], in_8(&via
[B
]) & ~TACK
);
145 out_8(&via
[B
], in_8(&via
[B
]) | TACK
);
148 static inline void negate_TIP_and_TACK(void)
151 udelay(EGRET_TACK_ASSERTED_DELAY
);
152 out_8(&via
[B
], in_8(&via
[B
]) & ~(TIP
| TACK
));
154 out_8(&via
[B
], in_8(&via
[B
]) | TIP
| TACK
);
157 static enum cuda_state
{
166 static struct adb_request
*current_req
;
167 static struct adb_request
*last_req
;
168 static unsigned char cuda_rbuf
[16];
169 static unsigned char *reply_ptr
;
170 static int reading_reply
;
171 static int data_index
;
174 static struct device_node
*vias
;
176 static int cuda_fully_inited
;
179 static int cuda_probe(void);
180 static int cuda_send_request(struct adb_request
*req
, int sync
);
181 static int cuda_adb_autopoll(int devs
);
182 static int cuda_reset_adb_bus(void);
183 #endif /* CONFIG_ADB */
185 static int cuda_init_via(void);
186 static void cuda_start(void);
187 static irqreturn_t
cuda_interrupt(int irq
, void *arg
);
188 static void cuda_input(unsigned char *buf
, int nb
);
189 void cuda_poll(void);
190 static int cuda_write(struct adb_request
*req
);
192 int cuda_request(struct adb_request
*req
,
193 void (*done
)(struct adb_request
*), int nbytes
, ...);
196 struct adb_driver via_cuda_driver
= {
199 .send_request
= cuda_send_request
,
200 .autopoll
= cuda_adb_autopoll
,
202 .reset_bus
= cuda_reset_adb_bus
,
204 #endif /* CONFIG_ADB */
207 int __init
find_via_cuda(void)
209 struct adb_request req
;
212 if (macintosh_config
->adb_type
!= MAC_ADB_CUDA
&&
213 macintosh_config
->adb_type
!= MAC_ADB_EGRET
)
218 mcu_is_egret
= macintosh_config
->adb_type
== MAC_ADB_EGRET
;
220 err
= cuda_init_via();
222 printk(KERN_ERR
"cuda_init_via() failed\n");
227 /* enable autopoll */
228 cuda_request(&req
, NULL
, 3, CUDA_PACKET
, CUDA_AUTOPOLL
, 1);
229 while (!req
.complete
)
235 int __init
find_via_cuda(void)
237 struct adb_request req
;
243 vias
= of_find_node_by_name(NULL
, "via-cuda");
247 err
= of_address_to_resource(vias
, 0, &res
);
249 printk(KERN_ERR
"via-cuda: Error getting \"reg\" property !\n");
252 via
= ioremap(res
.start
, 0x2000);
254 printk(KERN_ERR
"via-cuda: Can't map address !\n");
259 sys_ctrler
= SYS_CTRLER_CUDA
;
261 err
= cuda_init_via();
263 printk(KERN_ERR
"cuda_init_via() failed\n");
268 /* Clear and enable interrupts, but only on PPC. On 68K it's done */
269 /* for us by the main VIA driver in arch/m68k/mac/via.c */
271 out_8(&via
[IFR
], 0x7f); /* clear interrupts by writing 1s */
272 out_8(&via
[IER
], IER_SET
|SR_INT
); /* enable interrupt from SR */
274 /* enable autopoll */
275 cuda_request(&req
, NULL
, 3, CUDA_PACKET
, CUDA_AUTOPOLL
, 1);
276 while (!req
.complete
)
286 #endif /* !defined CONFIG_MAC */
288 static int __init
via_cuda_start(void)
294 cuda_irq
= IRQ_MAC_ADB
;
296 cuda_irq
= irq_of_parse_and_map(vias
, 0);
298 printk(KERN_ERR
"via-cuda: can't map interrupts for %pOF\n",
304 if (request_irq(cuda_irq
, cuda_interrupt
, 0, "ADB", cuda_interrupt
)) {
305 printk(KERN_ERR
"via-cuda: can't request irq %d\n", cuda_irq
);
309 pr_info("Macintosh Cuda and Egret driver.\n");
311 cuda_fully_inited
= 1;
315 device_initcall(via_cuda_start
);
322 if (sys_ctrler
!= SYS_CTRLER_CUDA
)
325 if (macintosh_config
->adb_type
!= MAC_ADB_CUDA
&&
326 macintosh_config
->adb_type
!= MAC_ADB_EGRET
)
333 #endif /* CONFIG_ADB */
335 static int __init
sync_egret(void)
337 if (TREQ_asserted(in_8(&via
[B
]))) {
338 /* Complete the inbound transfer */
339 assert_TIP_and_TACK();
343 (void)in_8(&via
[SR
]);
345 if (!TREQ_asserted(in_8(&via
[B
])))
348 negate_TIP_and_TACK();
349 } else if (in_8(&via
[B
]) & TIP
) {
350 /* Terminate the outbound transfer */
354 negate_TIP_and_TACK();
356 /* Clear shift register interrupt */
357 if (in_8(&via
[IFR
]) & SR_INT
)
358 (void)in_8(&via
[SR
]);
362 #define WAIT_FOR(cond, what) \
365 for (x = 1000; !(cond); --x) { \
367 pr_err("Timeout waiting for " what "\n"); \
375 __init
cuda_init_via(void)
378 out_8(&via
[IER
], 0x7f); /* disable interrupts from VIA */
379 (void)in_8(&via
[IER
]);
381 out_8(&via
[IER
], SR_INT
); /* disable SR interrupt from VIA */
384 out_8(&via
[DIRB
], (in_8(&via
[DIRB
]) | TACK
| TIP
) & ~TREQ
); /* TACK & TIP out */
385 out_8(&via
[ACR
], (in_8(&via
[ACR
]) & ~SR_CTRL
) | SR_EXT
); /* SR data in */
386 (void)in_8(&via
[SR
]); /* clear any left-over data */
391 negate_TIP_and_TACK();
393 /* delay 4ms and then clear any pending interrupt */
395 (void)in_8(&via
[SR
]);
396 out_8(&via
[IFR
], SR_INT
);
398 /* sync with the CUDA - assert TACK without TIP */
401 /* wait for the CUDA to assert TREQ in response */
402 WAIT_FOR(TREQ_asserted(in_8(&via
[B
])), "CUDA response to sync");
404 /* wait for the interrupt and then clear it */
405 WAIT_FOR(in_8(&via
[IFR
]) & SR_INT
, "CUDA response to sync (2)");
406 (void)in_8(&via
[SR
]);
407 out_8(&via
[IFR
], SR_INT
);
409 /* finish the sync by negating TACK */
412 /* wait for the CUDA to negate TREQ and the corresponding interrupt */
413 WAIT_FOR(!TREQ_asserted(in_8(&via
[B
])), "CUDA response to sync (3)");
414 WAIT_FOR(in_8(&via
[IFR
]) & SR_INT
, "CUDA response to sync (4)");
415 (void)in_8(&via
[SR
]);
416 out_8(&via
[IFR
], SR_INT
);
422 /* Send an ADB command */
424 cuda_send_request(struct adb_request
*req
, int sync
)
428 if ((via
== NULL
) || !cuda_fully_inited
) {
433 req
->reply_expected
= 1;
440 while (!req
->complete
)
447 /* Enable/disable autopolling */
449 cuda_adb_autopoll(int devs
)
451 struct adb_request req
;
453 if ((via
== NULL
) || !cuda_fully_inited
)
456 cuda_request(&req
, NULL
, 3, CUDA_PACKET
, CUDA_AUTOPOLL
, (devs
? 1: 0));
457 while (!req
.complete
)
462 /* Reset adb bus - how do we do this?? */
464 cuda_reset_adb_bus(void)
466 struct adb_request req
;
468 if ((via
== NULL
) || !cuda_fully_inited
)
471 cuda_request(&req
, NULL
, 2, ADB_PACKET
, 0); /* maybe? */
472 while (!req
.complete
)
476 #endif /* CONFIG_ADB */
478 /* Construct and send a cuda request */
480 cuda_request(struct adb_request
*req
, void (*done
)(struct adb_request
*),
491 req
->nbytes
= nbytes
;
493 va_start(list
, nbytes
);
494 for (i
= 0; i
< nbytes
; ++i
)
495 req
->data
[i
] = va_arg(list
, int);
497 req
->reply_expected
= 1;
498 return cuda_write(req
);
500 EXPORT_SYMBOL(cuda_request
);
503 cuda_write(struct adb_request
*req
)
507 if (req
->nbytes
< 2 || req
->data
[0] > CUDA_PACKET
) {
516 spin_lock_irqsave(&cuda_lock
, flags
);
518 last_req
->next
= req
;
523 if (cuda_state
== idle
)
526 spin_unlock_irqrestore(&cuda_lock
, flags
);
534 /* assert cuda_state == idle */
535 if (current_req
== NULL
)
538 if (TREQ_asserted(in_8(&via
[B
])))
539 return; /* a byte is coming in from the CUDA */
541 /* set the shift register to shift out and send a byte */
542 out_8(&via
[ACR
], in_8(&via
[ACR
]) | SR_OUT
);
543 out_8(&via
[SR
], current_req
->data
[data_index
++]);
545 assert_TIP_and_TACK();
548 cuda_state
= sent_first_byte
;
554 cuda_interrupt(0, NULL
);
556 EXPORT_SYMBOL(cuda_poll
);
558 #define ARRAY_FULL(a, p) ((p) - (a) == ARRAY_SIZE(a))
561 cuda_interrupt(int irq
, void *arg
)
565 struct adb_request
*req
= NULL
;
566 unsigned char ibuf
[16];
571 spin_lock_irqsave(&cuda_lock
, flags
);
573 /* On powermacs, this handler is registered for the VIA IRQ. But they use
574 * just the shift register IRQ -- other VIA interrupt sources are disabled.
575 * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
576 * we are polling, the shift register IRQ flag has already been cleared.
583 if ((in_8(&via
[IFR
]) & SR_INT
) == 0) {
584 spin_unlock_irqrestore(&cuda_lock
, flags
);
587 out_8(&via
[IFR
], SR_INT
);
591 status
= in_8(&via
[B
]) & (TIP
| TACK
| TREQ
);
593 switch (cuda_state
) {
595 /* System controller has unsolicited data for us */
596 (void)in_8(&via
[SR
]);
599 cuda_state
= reading
;
600 reply_ptr
= cuda_rbuf
;
605 /* System controller has reply data for us */
606 (void)in_8(&via
[SR
]);
608 cuda_state
= reading
;
609 reply_ptr
= current_req
->reply
;
613 case sent_first_byte
:
614 if (TREQ_asserted(status
)) {
616 out_8(&via
[ACR
], in_8(&via
[ACR
]) & ~SR_OUT
);
617 (void)in_8(&via
[SR
]);
618 negate_TIP_and_TACK();
620 /* Egret does not raise an "aborted" interrupt */
624 out_8(&via
[SR
], current_req
->data
[data_index
++]);
628 cuda_state
= sending
;
634 if (data_index
>= req
->nbytes
) {
635 out_8(&via
[ACR
], in_8(&via
[ACR
]) & ~SR_OUT
);
636 (void)in_8(&via
[SR
]);
637 negate_TIP_and_TACK();
639 if (req
->reply_expected
) {
640 cuda_state
= awaiting_reply
;
642 current_req
= req
->next
;
644 /* not sure about this */
649 out_8(&via
[SR
], req
->data
[data_index
++]);
657 full
= reading_reply
? ARRAY_FULL(current_req
->reply
, reply_ptr
)
658 : ARRAY_FULL(cuda_rbuf
, reply_ptr
);
660 (void)in_8(&via
[SR
]);
662 *reply_ptr
++ = in_8(&via
[SR
]);
663 if (!TREQ_asserted(status
) || full
) {
666 /* that's all folks */
667 negate_TIP_and_TACK();
668 cuda_state
= read_done
;
669 /* Egret does not raise a "read done" interrupt */
671 goto read_done_state
;
680 (void)in_8(&via
[SR
]);
684 req
->reply_len
= reply_ptr
- req
->reply
;
685 if (req
->data
[0] == ADB_PACKET
) {
686 /* Have to adjust the reply from ADB commands */
687 if (req
->reply_len
<= 2 || (req
->reply
[1] & 2) != 0) {
688 /* the 0x2 bit indicates no response */
691 /* leave just the command and result bytes in the reply */
693 memmove(req
->reply
, req
->reply
+ 2, req
->reply_len
);
696 current_req
= req
->next
;
700 /* This is tricky. We must break the spinlock to call
701 * cuda_input. However, doing so means we might get
702 * re-entered from another CPU getting an interrupt
703 * or calling cuda_poll(). I ended up using the stack
704 * (it's only for 16 bytes) and moving the actual
705 * call to cuda_input to outside of the lock.
707 ibuf_len
= reply_ptr
- cuda_rbuf
;
708 memcpy(ibuf
, cuda_rbuf
, ibuf_len
);
710 reply_ptr
= cuda_rbuf
;
713 if (cuda_state
== idle
&& TREQ_asserted(in_8(&via
[B
]))) {
715 cuda_state
= reading
;
720 pr_err("cuda_interrupt: unknown cuda_state %d?\n", cuda_state
);
722 spin_unlock_irqrestore(&cuda_lock
, flags
);
723 if (complete
&& req
) {
724 void (*done
)(struct adb_request
*) = req
->done
;
727 /* Here, we assume that if the request has a done member, the
728 * struct request will survive to setting req->complete to 1
734 cuda_input(ibuf
, ibuf_len
);
739 cuda_input(unsigned char *buf
, int nb
)
744 if (nb
== 5 && buf
[2] == 0x2c) {
745 extern int xmon_wants_key
, xmon_adb_keycode
;
746 if (xmon_wants_key
) {
747 xmon_adb_keycode
= buf
[3];
751 #endif /* CONFIG_XMON */
753 adb_input(buf
+2, nb
-2, buf
[1] & 0x40);
754 #endif /* CONFIG_ADB */
758 /* Egret sends these periodically. Might be useful as a 'heartbeat'
759 * to trigger a recovery for the VIA shift register errata.
764 print_hex_dump(KERN_INFO
, "cuda_input: ", DUMP_PREFIX_NONE
, 32, 1,
769 /* Offset between Unix time (1970-based) and Mac time (1904-based) */
770 #define RTC_OFFSET 2082844800
772 time64_t
cuda_get_time(void)
774 struct adb_request req
;
777 if (cuda_request(&req
, NULL
, 2, CUDA_PACKET
, CUDA_GET_TIME
) < 0)
779 while (!req
.complete
)
781 if (req
.reply_len
!= 7)
782 pr_err("%s: got %d byte reply\n", __func__
, req
.reply_len
);
783 now
= (req
.reply
[3] << 24) + (req
.reply
[4] << 16) +
784 (req
.reply
[5] << 8) + req
.reply
[6];
785 return (time64_t
)now
- RTC_OFFSET
;
788 int cuda_set_rtc_time(struct rtc_time
*tm
)
791 struct adb_request req
;
793 now
= lower_32_bits(rtc_tm_to_time64(tm
) + RTC_OFFSET
);
794 if (cuda_request(&req
, NULL
, 6, CUDA_PACKET
, CUDA_SET_TIME
,
795 now
>> 24, now
>> 16, now
>> 8, now
) < 0)
797 while (!req
.complete
)
799 if ((req
.reply_len
!= 3) && (req
.reply_len
!= 7))
800 pr_err("%s: got %d byte reply\n", __func__
, req
.reply_len
);