]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/m68k/mac/iop.c
2 * I/O Processor (IOP) management
3 * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice and this list of conditions.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice and this list of conditions in the documentation and/or other
12 * materials provided with the distribution.
16 * The IOP chips are used in the IIfx and some Quadras (900, 950) to manage
17 * serial and ADB. They are actually a 6502 processor and some glue logic.
19 * 990429 (jmt) - Initial implementation, just enough to knock the SCC IOP
20 * into compatible mode so nobody has to fiddle with the
21 * Serial Switch control panel anymore.
22 * 990603 (jmt) - Added code to grab the correct ISM IOP interrupt for OSS
23 * and non-OSS machines (at least I hope it's correct on a
24 * non-OSS machine -- someone with a Q900 or Q950 needs to
26 * 990605 (jmt) - Rearranged things a bit wrt IOP detection; iop_present is
27 * gone, IOP base addresses are now in an array and the
28 * globally-visible functions take an IOP number instead of an
29 * an actual base address.
30 * 990610 (jmt) - Finished the message passing framework and it seems to work.
31 * Sending _definitely_ works; my adb-bus.c mods can send
32 * messages and receive the MSG_COMPLETED status back from the
33 * IOP. The trick now is figuring out the message formats.
34 * 990611 (jmt) - More cleanups. Fixed problem where unclaimed messages on a
35 * receive channel were never properly acknowledged. Bracketed
36 * the remaining debug printk's with #ifdef's and disabled
37 * debugging. I can now type on the console.
38 * 990612 (jmt) - Copyright notice added. Reworked the way replies are handled.
39 * It turns out that replies are placed back in the send buffer
40 * for that channel; messages on the receive channels are always
41 * unsolicited messages from the IOP (and our replies to them
42 * should go back in the receive channel.) Also added tracking
43 * of device names to the listener functions ala the interrupt
45 * 990729 (jmt) - Added passing of pt_regs structure to IOP handlers. This is
46 * used by the new unified ADB driver.
50 * o The SCC IOP has to be placed in bypass mode before the serial console
51 * gets initialized. iop_init() would be one place to do that. Or the
52 * bootloader could do that. For now, the Serial Switch control panel
53 * is needed for that -- contrary to the changelog above.
54 * o Something should be periodically checking iop_alive() to make sure the
56 * o Some of the IOP manager routines need better error checking and
57 * return codes. Nothing major, just prettying up.
61 * -----------------------
62 * IOP Message Passing 101
63 * -----------------------
65 * The host talks to the IOPs using a rather simple message-passing scheme via
66 * a shared memory area in the IOP RAM. Each IOP has seven "channels"; each
67 * channel is connected to a specific software driver on the IOP. For example
68 * on the SCC IOP there is one channel for each serial port. Each channel has
69 * an incoming and and outgoing message queue with a depth of one.
71 * A message is 32 bytes plus a state byte for the channel (MSG_IDLE, MSG_NEW,
72 * MSG_RCVD, MSG_COMPLETE). To send a message you copy the message into the
73 * buffer, set the state to MSG_NEW and signal the IOP by setting the IRQ flag
74 * in the IOP control to 1. The IOP will move the state to MSG_RCVD when it
75 * receives the message and then to MSG_COMPLETE when the message processing
76 * has completed. It is the host's responsibility at that point to read the
77 * reply back out of the send channel buffer and reset the channel state back
80 * To receive message from the IOP the same procedure is used except the roles
81 * are reversed. That is, the IOP puts message in the channel with a state of
82 * MSG_NEW, and the host receives the message and move its state to MSG_RCVD
83 * and then to MSG_COMPLETE when processing is completed and the reply (if any)
84 * has been placed back in the receive channel. The IOP will then reset the
85 * channel state to MSG_IDLE.
87 * Two sets of host interrupts are provided, INT0 and INT1. Both appear on one
88 * interrupt level; they are distinguished by a pair of bits in the IOP status
89 * register. The IOP will raise INT0 when one or more messages in the send
90 * channels have gone to the MSG_COMPLETE state and it will raise INT1 when one
91 * or more messages on the receive channels have gone to the MSG_NEW state.
93 * Since each channel handles only one message we have to implement a small
94 * interrupt-driven queue on our end. Messages to be sent are placed on the
95 * queue for sending and contain a pointer to an optional callback function.
96 * The handler for a message is called when the message state goes to
99 * For receiving message we maintain a list of handler functions to call when
100 * a message is received on that IOP/channel combination. The handlers are
101 * called much like an interrupt handler and are passed a copy of the message
102 * from the IOP. The message state will be in MSG_RCVD while the handler runs;
103 * it is the handler's responsibility to call iop_complete_message() when
104 * finished; this function moves the message state to MSG_COMPLETE and signals
105 * the IOP. This two-step process is provided to allow the handler to defer
106 * message processing to a bottom-half handler if the processing will take
107 * a significant amount of time (handlers are called at interrupt time so they
108 * should execute quickly.)
111 #include <linux/types.h>
112 #include <linux/kernel.h>
113 #include <linux/mm.h>
114 #include <linux/delay.h>
115 #include <linux/init.h>
116 #include <linux/interrupt.h>
118 #include <asm/macintosh.h>
119 #include <asm/macints.h>
120 #include <asm/mac_iop.h>
123 #define iop_pr_debug(fmt, ...) \
124 printk(KERN_DEBUG "%s: " fmt, __func__, ##__VA_ARGS__)
125 #define iop_pr_cont(fmt, ...) \
126 printk(KERN_CONT fmt, ##__VA_ARGS__)
128 #define iop_pr_debug(fmt, ...) \
129 no_printk(KERN_DEBUG "%s: " fmt, __func__, ##__VA_ARGS__)
130 #define iop_pr_cont(fmt, ...) \
131 no_printk(KERN_CONT fmt, ##__VA_ARGS__)
134 /* Non-zero if the IOPs are present */
136 int iop_scc_present
, iop_ism_present
;
138 /* structure for tracking channel listeners */
142 void (*handler
)(struct iop_msg
*);
146 * IOP structures for the two IOPs
148 * The SCC IOP controls both serial ports (A and B) as its two functions.
149 * The ISM IOP controls the SWIM (floppy drive) and ADB.
152 static volatile struct mac_iop
*iop_base
[NUM_IOPS
];
158 static struct iop_msg iop_msg_pool
[NUM_IOP_MSGS
];
159 static struct iop_msg
*iop_send_queue
[NUM_IOPS
][NUM_IOP_CHAN
];
160 static struct listener iop_listeners
[NUM_IOPS
][NUM_IOP_CHAN
];
162 irqreturn_t
iop_ism_irq(int, void *);
165 * Private access functions
168 static __inline__
void iop_loadaddr(volatile struct mac_iop
*iop
, __u16 addr
)
170 iop
->ram_addr_lo
= addr
;
171 iop
->ram_addr_hi
= addr
>> 8;
174 static __inline__ __u8
iop_readb(volatile struct mac_iop
*iop
, __u16 addr
)
176 iop
->ram_addr_lo
= addr
;
177 iop
->ram_addr_hi
= addr
>> 8;
178 return iop
->ram_data
;
181 static __inline__
void iop_writeb(volatile struct mac_iop
*iop
, __u16 addr
, __u8 data
)
183 iop
->ram_addr_lo
= addr
;
184 iop
->ram_addr_hi
= addr
>> 8;
185 iop
->ram_data
= data
;
188 static __inline__
void iop_stop(volatile struct mac_iop
*iop
)
190 iop
->status_ctrl
= IOP_AUTOINC
;
193 static __inline__
void iop_start(volatile struct mac_iop
*iop
)
195 iop
->status_ctrl
= IOP_RUN
| IOP_AUTOINC
;
198 static __inline__
void iop_interrupt(volatile struct mac_iop
*iop
)
200 iop
->status_ctrl
= IOP_IRQ
| IOP_RUN
| IOP_AUTOINC
;
203 static int iop_alive(volatile struct mac_iop
*iop
)
207 retval
= (iop_readb(iop
, IOP_ADDR_ALIVE
) == 0xFF);
208 iop_writeb(iop
, IOP_ADDR_ALIVE
, 0);
212 static struct iop_msg
*iop_get_unused_msg(void)
217 local_irq_save(flags
);
219 for (i
= 0 ; i
< NUM_IOP_MSGS
; i
++) {
220 if (iop_msg_pool
[i
].status
== IOP_MSGSTATUS_UNUSED
) {
221 iop_msg_pool
[i
].status
= IOP_MSGSTATUS_WAITING
;
222 local_irq_restore(flags
);
223 return &iop_msg_pool
[i
];
227 local_irq_restore(flags
);
232 * Initialize the IOPs, if present.
235 void __init
iop_init(void)
239 if (macintosh_config
->scc_type
== MAC_SCC_IOP
) {
240 if (macintosh_config
->ident
== MAC_MODEL_IIFX
)
241 iop_base
[IOP_NUM_SCC
] = (struct mac_iop
*)SCC_IOP_BASE_IIFX
;
243 iop_base
[IOP_NUM_SCC
] = (struct mac_iop
*)SCC_IOP_BASE_QUADRA
;
245 pr_debug("SCC IOP detected at %p\n", iop_base
[IOP_NUM_SCC
]);
247 if (macintosh_config
->adb_type
== MAC_ADB_IOP
) {
248 if (macintosh_config
->ident
== MAC_MODEL_IIFX
)
249 iop_base
[IOP_NUM_ISM
] = (struct mac_iop
*)ISM_IOP_BASE_IIFX
;
251 iop_base
[IOP_NUM_ISM
] = (struct mac_iop
*)ISM_IOP_BASE_QUADRA
;
253 pr_debug("ISM IOP detected at %p\n", iop_base
[IOP_NUM_ISM
]);
255 iop_stop(iop_base
[IOP_NUM_ISM
]);
256 iop_start(iop_base
[IOP_NUM_ISM
]);
257 iop_alive(iop_base
[IOP_NUM_ISM
]); /* clears the alive flag */
260 /* Make the whole pool available and empty the queues */
262 for (i
= 0 ; i
< NUM_IOP_MSGS
; i
++) {
263 iop_msg_pool
[i
].status
= IOP_MSGSTATUS_UNUSED
;
266 for (i
= 0 ; i
< NUM_IOP_CHAN
; i
++) {
267 iop_send_queue
[IOP_NUM_SCC
][i
] = NULL
;
268 iop_send_queue
[IOP_NUM_ISM
][i
] = NULL
;
269 iop_listeners
[IOP_NUM_SCC
][i
].devname
= NULL
;
270 iop_listeners
[IOP_NUM_SCC
][i
].handler
= NULL
;
271 iop_listeners
[IOP_NUM_ISM
][i
].devname
= NULL
;
272 iop_listeners
[IOP_NUM_ISM
][i
].handler
= NULL
;
277 * Register the interrupt handler for the IOPs.
280 void __init
iop_register_interrupts(void)
282 if (iop_ism_present
) {
283 if (macintosh_config
->ident
== MAC_MODEL_IIFX
) {
284 if (request_irq(IRQ_MAC_ADB
, iop_ism_irq
, 0,
285 "ISM IOP", (void *)IOP_NUM_ISM
))
286 pr_err("Couldn't register ISM IOP interrupt\n");
288 if (request_irq(IRQ_VIA2_0
, iop_ism_irq
, 0, "ISM IOP",
289 (void *)IOP_NUM_ISM
))
290 pr_err("Couldn't register ISM IOP interrupt\n");
292 if (!iop_alive(iop_base
[IOP_NUM_ISM
])) {
293 pr_warn("IOP: oh my god, they killed the ISM IOP!\n");
295 pr_warn("IOP: the ISM IOP seems to be alive.\n");
301 * Register or unregister a listener for a specific IOP and channel
303 * If the handler pointer is NULL the current listener (if any) is
304 * unregistered. Otherwise the new listener is registered provided
305 * there is no existing listener registered.
308 int iop_listen(uint iop_num
, uint chan
,
309 void (*handler
)(struct iop_msg
*),
312 if ((iop_num
>= NUM_IOPS
) || !iop_base
[iop_num
]) return -EINVAL
;
313 if (chan
>= NUM_IOP_CHAN
) return -EINVAL
;
314 if (iop_listeners
[iop_num
][chan
].handler
&& handler
) return -EINVAL
;
315 iop_listeners
[iop_num
][chan
].devname
= devname
;
316 iop_listeners
[iop_num
][chan
].handler
= handler
;
321 * Complete reception of a message, which just means copying the reply
322 * into the buffer, setting the channel state to MSG_COMPLETE and
326 void iop_complete_message(struct iop_msg
*msg
)
328 int iop_num
= msg
->iop_num
;
329 int chan
= msg
->channel
;
332 iop_pr_debug("iop_num %d chan %d reply %*ph\n",
333 msg
->iop_num
, msg
->channel
, IOP_MSG_LEN
, msg
->reply
);
335 offset
= IOP_ADDR_RECV_MSG
+ (msg
->channel
* IOP_MSG_LEN
);
337 for (i
= 0 ; i
< IOP_MSG_LEN
; i
++, offset
++) {
338 iop_writeb(iop_base
[iop_num
], offset
, msg
->reply
[i
]);
341 iop_writeb(iop_base
[iop_num
],
342 IOP_ADDR_RECV_STATE
+ chan
, IOP_MSG_COMPLETE
);
343 iop_interrupt(iop_base
[msg
->iop_num
]);
345 msg
->status
= IOP_MSGSTATUS_UNUSED
;
349 * Actually put a message into a send channel buffer
352 static void iop_do_send(struct iop_msg
*msg
)
354 volatile struct mac_iop
*iop
= iop_base
[msg
->iop_num
];
357 iop_pr_debug("iop_num %d chan %d message %*ph\n",
358 msg
->iop_num
, msg
->channel
, IOP_MSG_LEN
, msg
->message
);
360 offset
= IOP_ADDR_SEND_MSG
+ (msg
->channel
* IOP_MSG_LEN
);
362 for (i
= 0 ; i
< IOP_MSG_LEN
; i
++, offset
++) {
363 iop_writeb(iop
, offset
, msg
->message
[i
]);
366 iop_writeb(iop
, IOP_ADDR_SEND_STATE
+ msg
->channel
, IOP_MSG_NEW
);
372 * Handle sending a message on a channel that
373 * has gone into the IOP_MSG_COMPLETE state.
376 static void iop_handle_send(uint iop_num
, uint chan
)
378 volatile struct mac_iop
*iop
= iop_base
[iop_num
];
382 iop_writeb(iop
, IOP_ADDR_SEND_STATE
+ chan
, IOP_MSG_IDLE
);
384 if (!(msg
= iop_send_queue
[iop_num
][chan
])) return;
386 msg
->status
= IOP_MSGSTATUS_COMPLETE
;
387 offset
= IOP_ADDR_SEND_MSG
+ (chan
* IOP_MSG_LEN
);
388 for (i
= 0 ; i
< IOP_MSG_LEN
; i
++, offset
++) {
389 msg
->reply
[i
] = iop_readb(iop
, offset
);
391 iop_pr_debug("iop_num %d chan %d reply %*ph\n",
392 iop_num
, chan
, IOP_MSG_LEN
, msg
->reply
);
394 if (msg
->handler
) (*msg
->handler
)(msg
);
395 msg
->status
= IOP_MSGSTATUS_UNUSED
;
397 iop_send_queue
[iop_num
][chan
] = msg
;
398 if (msg
&& iop_readb(iop
, IOP_ADDR_SEND_STATE
+ chan
) == IOP_MSG_IDLE
)
403 * Handle reception of a message on a channel that has
404 * gone into the IOP_MSG_NEW state.
407 static void iop_handle_recv(uint iop_num
, uint chan
)
409 volatile struct mac_iop
*iop
= iop_base
[iop_num
];
413 msg
= iop_get_unused_msg();
414 msg
->iop_num
= iop_num
;
416 msg
->status
= IOP_MSGSTATUS_UNSOL
;
417 msg
->handler
= iop_listeners
[iop_num
][chan
].handler
;
419 offset
= IOP_ADDR_RECV_MSG
+ (chan
* IOP_MSG_LEN
);
421 for (i
= 0 ; i
< IOP_MSG_LEN
; i
++, offset
++) {
422 msg
->message
[i
] = iop_readb(iop
, offset
);
424 iop_pr_debug("iop_num %d chan %d message %*ph\n",
425 iop_num
, chan
, IOP_MSG_LEN
, msg
->message
);
427 iop_writeb(iop
, IOP_ADDR_RECV_STATE
+ chan
, IOP_MSG_RCVD
);
429 /* If there is a listener, call it now. Otherwise complete */
430 /* the message ourselves to avoid possible stalls. */
433 (*msg
->handler
)(msg
);
435 memset(msg
->reply
, 0, IOP_MSG_LEN
);
436 iop_complete_message(msg
);
443 * The message is placed at the end of the send queue. Afterwards if the
444 * channel is idle we force an immediate send of the next message in the
448 int iop_send_message(uint iop_num
, uint chan
, void *privdata
,
449 uint msg_len
, __u8
*msg_data
,
450 void (*handler
)(struct iop_msg
*))
452 struct iop_msg
*msg
, *q
;
454 if ((iop_num
>= NUM_IOPS
) || !iop_base
[iop_num
]) return -EINVAL
;
455 if (chan
>= NUM_IOP_CHAN
) return -EINVAL
;
456 if (msg_len
> IOP_MSG_LEN
) return -EINVAL
;
458 msg
= iop_get_unused_msg();
459 if (!msg
) return -ENOMEM
;
462 msg
->status
= IOP_MSGSTATUS_WAITING
;
463 msg
->iop_num
= iop_num
;
465 msg
->caller_priv
= privdata
;
466 memcpy(msg
->message
, msg_data
, msg_len
);
467 msg
->handler
= handler
;
469 if (!(q
= iop_send_queue
[iop_num
][chan
])) {
470 iop_send_queue
[iop_num
][chan
] = msg
;
473 while (q
->next
) q
= q
->next
;
481 * Upload code to the shared RAM of an IOP.
484 void iop_upload_code(uint iop_num
, __u8
*code_start
,
485 uint code_len
, __u16 shared_ram_start
)
487 if ((iop_num
>= NUM_IOPS
) || !iop_base
[iop_num
]) return;
489 iop_loadaddr(iop_base
[iop_num
], shared_ram_start
);
492 iop_base
[iop_num
]->ram_data
= *code_start
++;
497 * Download code from the shared RAM of an IOP.
500 void iop_download_code(uint iop_num
, __u8
*code_start
,
501 uint code_len
, __u16 shared_ram_start
)
503 if ((iop_num
>= NUM_IOPS
) || !iop_base
[iop_num
]) return;
505 iop_loadaddr(iop_base
[iop_num
], shared_ram_start
);
508 *code_start
++ = iop_base
[iop_num
]->ram_data
;
513 * Compare the code in the shared RAM of an IOP with a copy in system memory
514 * and return 0 on match or the first nonmatching system memory address on
518 __u8
*iop_compare_code(uint iop_num
, __u8
*code_start
,
519 uint code_len
, __u16 shared_ram_start
)
521 if ((iop_num
>= NUM_IOPS
) || !iop_base
[iop_num
]) return code_start
;
523 iop_loadaddr(iop_base
[iop_num
], shared_ram_start
);
526 if (*code_start
!= iop_base
[iop_num
]->ram_data
) {
535 * Handle an ISM IOP interrupt
538 irqreturn_t
iop_ism_irq(int irq
, void *dev_id
)
540 uint iop_num
= (uint
) dev_id
;
541 volatile struct mac_iop
*iop
= iop_base
[iop_num
];
543 u8 events
= iop
->status_ctrl
& (IOP_INT0
| IOP_INT1
);
546 iop_pr_debug("iop_num %d status %02X\n", iop_num
,
549 /* INT0 indicates state change on an outgoing message channel */
550 if (events
& IOP_INT0
) {
551 iop
->status_ctrl
= IOP_INT0
| IOP_RUN
| IOP_AUTOINC
;
552 for (i
= 0; i
< NUM_IOP_CHAN
; i
++) {
553 state
= iop_readb(iop
, IOP_ADDR_SEND_STATE
+ i
);
554 if (state
== IOP_MSG_COMPLETE
)
555 iop_handle_send(iop_num
, i
);
556 else if (state
!= IOP_MSG_IDLE
)
557 iop_pr_debug("chan %d send state %02X\n",
562 /* INT1 for incoming messages */
563 if (events
& IOP_INT1
) {
564 iop
->status_ctrl
= IOP_INT1
| IOP_RUN
| IOP_AUTOINC
;
565 for (i
= 0; i
< NUM_IOP_CHAN
; i
++) {
566 state
= iop_readb(iop
, IOP_ADDR_RECV_STATE
+ i
);
567 if (state
== IOP_MSG_NEW
)
568 iop_handle_recv(iop_num
, i
);
569 else if (state
!= IOP_MSG_IDLE
)
570 iop_pr_debug("chan %d recv state %02X\n",
575 events
= iop
->status_ctrl
& (IOP_INT0
| IOP_INT1
);
581 void iop_ism_irq_poll(uint iop_num
)
585 local_irq_save(flags
);
586 iop_ism_irq(0, (void *)iop_num
);
587 local_irq_restore(flags
);