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[linux-2.6/linux-acpi-2.6.git] / arch / m68k / mac / iop.c
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1 /*
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
7 * are met:
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
25 * check this.)
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
44 * handlers.
45 * 990729 (jmt) - Added passing of pt_regs structure to IOP handlers. This is
46 * used by the new unified ADB driver.
48 * TODO:
50 * o Something should be periodically checking iop_alive() to make sure the
51 * IOP hasn't died.
52 * o Some of the IOP manager routines need better error checking and
53 * return codes. Nothing major, just prettying up.
57 * -----------------------
58 * IOP Message Passing 101
59 * -----------------------
61 * The host talks to the IOPs using a rather simple message-passing scheme via
62 * a shared memory area in the IOP RAM. Each IOP has seven "channels"; each
63 * channel is conneced to a specific software driver on the IOP. For example
64 * on the SCC IOP there is one channel for each serial port. Each channel has
65 * an incoming and and outgoing message queue with a depth of one.
67 * A message is 32 bytes plus a state byte for the channel (MSG_IDLE, MSG_NEW,
68 * MSG_RCVD, MSG_COMPLETE). To send a message you copy the message into the
69 * buffer, set the state to MSG_NEW and signal the IOP by setting the IRQ flag
70 * in the IOP control to 1. The IOP will move the state to MSG_RCVD when it
71 * receives the message and then to MSG_COMPLETE when the message processing
72 * has completed. It is the host's responsibility at that point to read the
73 * reply back out of the send channel buffer and reset the channel state back
74 * to MSG_IDLE.
76 * To receive message from the IOP the same procedure is used except the roles
77 * are reversed. That is, the IOP puts message in the channel with a state of
78 * MSG_NEW, and the host receives the message and move its state to MSG_RCVD
79 * and then to MSG_COMPLETE when processing is completed and the reply (if any)
80 * has been placed back in the receive channel. The IOP will then reset the
81 * channel state to MSG_IDLE.
83 * Two sets of host interrupts are provided, INT0 and INT1. Both appear on one
84 * interrupt level; they are distinguished by a pair of bits in the IOP status
85 * register. The IOP will raise INT0 when one or more messages in the send
86 * channels have gone to the MSG_COMPLETE state and it will raise INT1 when one
87 * or more messages on the receive channels have gone to the MSG_NEW state.
89 * Since each channel handles only one message we have to implement a small
90 * interrupt-driven queue on our end. Messages to be sent are placed on the
91 * queue for sending and contain a pointer to an optional callback function.
92 * The handler for a message is called when the message state goes to
93 * MSG_COMPLETE.
95 * For receiving message we maintain a list of handler functions to call when
96 * a message is received on that IOP/channel combination. The handlers are
97 * called much like an interrupt handler and are passed a copy of the message
98 * from the IOP. The message state will be in MSG_RCVD while the handler runs;
99 * it is the handler's responsibility to call iop_complete_message() when
100 * finished; this function moves the message state to MSG_COMPLETE and signals
101 * the IOP. This two-step process is provided to allow the handler to defer
102 * message processing to a bottom-half handler if the processing will take
103 * a significant amount of time (handlers are called at interrupt time so they
104 * should execute quickly.)
107 #include <linux/types.h>
108 #include <linux/kernel.h>
109 #include <linux/mm.h>
110 #include <linux/delay.h>
111 #include <linux/init.h>
112 #include <linux/interrupt.h>
114 #include <asm/bootinfo.h>
115 #include <asm/macintosh.h>
116 #include <asm/macints.h>
117 #include <asm/mac_iop.h>
118 #include <asm/mac_oss.h>
120 /*#define DEBUG_IOP*/
122 /* Set to non-zero if the IOPs are present. Set by iop_init() */
124 int iop_scc_present,iop_ism_present;
126 /* structure for tracking channel listeners */
128 struct listener {
129 const char *devname;
130 void (*handler)(struct iop_msg *);
134 * IOP structures for the two IOPs
136 * The SCC IOP controls both serial ports (A and B) as its two functions.
137 * The ISM IOP controls the SWIM (floppy drive) and ADB.
140 static volatile struct mac_iop *iop_base[NUM_IOPS];
143 * IOP message queues
146 static struct iop_msg iop_msg_pool[NUM_IOP_MSGS];
147 static struct iop_msg *iop_send_queue[NUM_IOPS][NUM_IOP_CHAN];
148 static struct listener iop_listeners[NUM_IOPS][NUM_IOP_CHAN];
150 irqreturn_t iop_ism_irq(int, void *);
152 extern void oss_irq_enable(int);
155 * Private access functions
158 static __inline__ void iop_loadaddr(volatile struct mac_iop *iop, __u16 addr)
160 iop->ram_addr_lo = addr;
161 iop->ram_addr_hi = addr >> 8;
164 static __inline__ __u8 iop_readb(volatile struct mac_iop *iop, __u16 addr)
166 iop->ram_addr_lo = addr;
167 iop->ram_addr_hi = addr >> 8;
168 return iop->ram_data;
171 static __inline__ void iop_writeb(volatile struct mac_iop *iop, __u16 addr, __u8 data)
173 iop->ram_addr_lo = addr;
174 iop->ram_addr_hi = addr >> 8;
175 iop->ram_data = data;
178 static __inline__ void iop_stop(volatile struct mac_iop *iop)
180 iop->status_ctrl &= ~IOP_RUN;
183 static __inline__ void iop_start(volatile struct mac_iop *iop)
185 iop->status_ctrl = IOP_RUN | IOP_AUTOINC;
188 static __inline__ void iop_bypass(volatile struct mac_iop *iop)
190 iop->status_ctrl |= IOP_BYPASS;
193 static __inline__ void iop_interrupt(volatile struct mac_iop *iop)
195 iop->status_ctrl |= IOP_IRQ;
198 static int iop_alive(volatile struct mac_iop *iop)
200 int retval;
202 retval = (iop_readb(iop, IOP_ADDR_ALIVE) == 0xFF);
203 iop_writeb(iop, IOP_ADDR_ALIVE, 0);
204 return retval;
207 static struct iop_msg *iop_alloc_msg(void)
209 int i;
210 unsigned long flags;
212 local_irq_save(flags);
214 for (i = 0 ; i < NUM_IOP_MSGS ; i++) {
215 if (iop_msg_pool[i].status == IOP_MSGSTATUS_UNUSED) {
216 iop_msg_pool[i].status = IOP_MSGSTATUS_WAITING;
217 local_irq_restore(flags);
218 return &iop_msg_pool[i];
222 local_irq_restore(flags);
223 return NULL;
226 static void iop_free_msg(struct iop_msg *msg)
228 msg->status = IOP_MSGSTATUS_UNUSED;
232 * This is called by the startup code before anything else. Its purpose
233 * is to find and initialize the IOPs early in the boot sequence, so that
234 * the serial IOP can be placed into bypass mode _before_ we try to
235 * initialize the serial console.
238 void __init iop_preinit(void)
240 if (macintosh_config->scc_type == MAC_SCC_IOP) {
241 if (macintosh_config->ident == MAC_MODEL_IIFX) {
242 iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_IIFX;
243 } else {
244 iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA;
246 iop_base[IOP_NUM_SCC]->status_ctrl = 0x87;
247 iop_scc_present = 1;
248 } else {
249 iop_base[IOP_NUM_SCC] = NULL;
250 iop_scc_present = 0;
252 if (macintosh_config->adb_type == MAC_ADB_IOP) {
253 if (macintosh_config->ident == MAC_MODEL_IIFX) {
254 iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_IIFX;
255 } else {
256 iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_QUADRA;
258 iop_base[IOP_NUM_ISM]->status_ctrl = 0;
259 iop_ism_present = 1;
260 } else {
261 iop_base[IOP_NUM_ISM] = NULL;
262 iop_ism_present = 0;
267 * Initialize the IOPs, if present.
270 void __init iop_init(void)
272 int i;
274 if (iop_scc_present) {
275 printk("IOP: detected SCC IOP at %p\n", iop_base[IOP_NUM_SCC]);
277 if (iop_ism_present) {
278 printk("IOP: detected ISM IOP at %p\n", iop_base[IOP_NUM_ISM]);
279 iop_start(iop_base[IOP_NUM_ISM]);
280 iop_alive(iop_base[IOP_NUM_ISM]); /* clears the alive flag */
283 /* Make the whole pool available and empty the queues */
285 for (i = 0 ; i < NUM_IOP_MSGS ; i++) {
286 iop_msg_pool[i].status = IOP_MSGSTATUS_UNUSED;
289 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
290 iop_send_queue[IOP_NUM_SCC][i] = NULL;
291 iop_send_queue[IOP_NUM_ISM][i] = NULL;
292 iop_listeners[IOP_NUM_SCC][i].devname = NULL;
293 iop_listeners[IOP_NUM_SCC][i].handler = NULL;
294 iop_listeners[IOP_NUM_ISM][i].devname = NULL;
295 iop_listeners[IOP_NUM_ISM][i].handler = NULL;
300 * Register the interrupt handler for the IOPs.
301 * TODO: might be wrong for non-OSS machines. Anyone?
304 void __init iop_register_interrupts(void)
306 if (iop_ism_present) {
307 if (oss_present) {
308 if (request_irq(OSS_IRQLEV_IOPISM, iop_ism_irq,
309 IRQ_FLG_LOCK, "ISM IOP",
310 (void *) IOP_NUM_ISM))
311 pr_err("Couldn't register ISM IOP interrupt\n");
312 oss_irq_enable(IRQ_MAC_ADB);
313 } else {
314 if (request_irq(IRQ_VIA2_0, iop_ism_irq,
315 IRQ_FLG_LOCK|IRQ_FLG_FAST, "ISM IOP",
316 (void *) IOP_NUM_ISM))
317 pr_err("Couldn't register ISM IOP interrupt\n");
319 if (!iop_alive(iop_base[IOP_NUM_ISM])) {
320 printk("IOP: oh my god, they killed the ISM IOP!\n");
321 } else {
322 printk("IOP: the ISM IOP seems to be alive.\n");
328 * Register or unregister a listener for a specific IOP and channel
330 * If the handler pointer is NULL the current listener (if any) is
331 * unregistered. Otherwise the new listener is registered provided
332 * there is no existing listener registered.
335 int iop_listen(uint iop_num, uint chan,
336 void (*handler)(struct iop_msg *),
337 const char *devname)
339 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
340 if (chan >= NUM_IOP_CHAN) return -EINVAL;
341 if (iop_listeners[iop_num][chan].handler && handler) return -EINVAL;
342 iop_listeners[iop_num][chan].devname = devname;
343 iop_listeners[iop_num][chan].handler = handler;
344 return 0;
348 * Complete reception of a message, which just means copying the reply
349 * into the buffer, setting the channel state to MSG_COMPLETE and
350 * notifying the IOP.
353 void iop_complete_message(struct iop_msg *msg)
355 int iop_num = msg->iop_num;
356 int chan = msg->channel;
357 int i,offset;
359 #ifdef DEBUG_IOP
360 printk("iop_complete(%p): iop %d chan %d\n", msg, msg->iop_num, msg->channel);
361 #endif
363 offset = IOP_ADDR_RECV_MSG + (msg->channel * IOP_MSG_LEN);
365 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
366 iop_writeb(iop_base[iop_num], offset, msg->reply[i]);
369 iop_writeb(iop_base[iop_num],
370 IOP_ADDR_RECV_STATE + chan, IOP_MSG_COMPLETE);
371 iop_interrupt(iop_base[msg->iop_num]);
373 iop_free_msg(msg);
377 * Actually put a message into a send channel buffer
380 static void iop_do_send(struct iop_msg *msg)
382 volatile struct mac_iop *iop = iop_base[msg->iop_num];
383 int i,offset;
385 offset = IOP_ADDR_SEND_MSG + (msg->channel * IOP_MSG_LEN);
387 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
388 iop_writeb(iop, offset, msg->message[i]);
391 iop_writeb(iop, IOP_ADDR_SEND_STATE + msg->channel, IOP_MSG_NEW);
393 iop_interrupt(iop);
397 * Handle sending a message on a channel that
398 * has gone into the IOP_MSG_COMPLETE state.
401 static void iop_handle_send(uint iop_num, uint chan)
403 volatile struct mac_iop *iop = iop_base[iop_num];
404 struct iop_msg *msg,*msg2;
405 int i,offset;
407 #ifdef DEBUG_IOP
408 printk("iop_handle_send: iop %d channel %d\n", iop_num, chan);
409 #endif
411 iop_writeb(iop, IOP_ADDR_SEND_STATE + chan, IOP_MSG_IDLE);
413 if (!(msg = iop_send_queue[iop_num][chan])) return;
415 msg->status = IOP_MSGSTATUS_COMPLETE;
416 offset = IOP_ADDR_SEND_MSG + (chan * IOP_MSG_LEN);
417 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
418 msg->reply[i] = iop_readb(iop, offset);
420 if (msg->handler) (*msg->handler)(msg);
421 msg2 = msg;
422 msg = msg->next;
423 iop_free_msg(msg2);
425 iop_send_queue[iop_num][chan] = msg;
426 if (msg) iop_do_send(msg);
430 * Handle reception of a message on a channel that has
431 * gone into the IOP_MSG_NEW state.
434 static void iop_handle_recv(uint iop_num, uint chan)
436 volatile struct mac_iop *iop = iop_base[iop_num];
437 int i,offset;
438 struct iop_msg *msg;
440 #ifdef DEBUG_IOP
441 printk("iop_handle_recv: iop %d channel %d\n", iop_num, chan);
442 #endif
444 msg = iop_alloc_msg();
445 msg->iop_num = iop_num;
446 msg->channel = chan;
447 msg->status = IOP_MSGSTATUS_UNSOL;
448 msg->handler = iop_listeners[iop_num][chan].handler;
450 offset = IOP_ADDR_RECV_MSG + (chan * IOP_MSG_LEN);
452 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
453 msg->message[i] = iop_readb(iop, offset);
456 iop_writeb(iop, IOP_ADDR_RECV_STATE + chan, IOP_MSG_RCVD);
458 /* If there is a listener, call it now. Otherwise complete */
459 /* the message ourselves to avoid possible stalls. */
461 if (msg->handler) {
462 (*msg->handler)(msg);
463 } else {
464 #ifdef DEBUG_IOP
465 printk("iop_handle_recv: unclaimed message on iop %d channel %d\n", iop_num, chan);
466 printk("iop_handle_recv:");
467 for (i = 0 ; i < IOP_MSG_LEN ; i++) {
468 printk(" %02X", (uint) msg->message[i]);
470 printk("\n");
471 #endif
472 iop_complete_message(msg);
477 * Send a message
479 * The message is placed at the end of the send queue. Afterwards if the
480 * channel is idle we force an immediate send of the next message in the
481 * queue.
484 int iop_send_message(uint iop_num, uint chan, void *privdata,
485 uint msg_len, __u8 *msg_data,
486 void (*handler)(struct iop_msg *))
488 struct iop_msg *msg, *q;
490 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
491 if (chan >= NUM_IOP_CHAN) return -EINVAL;
492 if (msg_len > IOP_MSG_LEN) return -EINVAL;
494 msg = iop_alloc_msg();
495 if (!msg) return -ENOMEM;
497 msg->next = NULL;
498 msg->status = IOP_MSGSTATUS_WAITING;
499 msg->iop_num = iop_num;
500 msg->channel = chan;
501 msg->caller_priv = privdata;
502 memcpy(msg->message, msg_data, msg_len);
503 msg->handler = handler;
505 if (!(q = iop_send_queue[iop_num][chan])) {
506 iop_send_queue[iop_num][chan] = msg;
507 } else {
508 while (q->next) q = q->next;
509 q->next = msg;
512 if (iop_readb(iop_base[iop_num],
513 IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) {
514 iop_do_send(msg);
517 return 0;
521 * Upload code to the shared RAM of an IOP.
524 void iop_upload_code(uint iop_num, __u8 *code_start,
525 uint code_len, __u16 shared_ram_start)
527 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;
529 iop_loadaddr(iop_base[iop_num], shared_ram_start);
531 while (code_len--) {
532 iop_base[iop_num]->ram_data = *code_start++;
537 * Download code from the shared RAM of an IOP.
540 void iop_download_code(uint iop_num, __u8 *code_start,
541 uint code_len, __u16 shared_ram_start)
543 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;
545 iop_loadaddr(iop_base[iop_num], shared_ram_start);
547 while (code_len--) {
548 *code_start++ = iop_base[iop_num]->ram_data;
553 * Compare the code in the shared RAM of an IOP with a copy in system memory
554 * and return 0 on match or the first nonmatching system memory address on
555 * failure.
558 __u8 *iop_compare_code(uint iop_num, __u8 *code_start,
559 uint code_len, __u16 shared_ram_start)
561 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return code_start;
563 iop_loadaddr(iop_base[iop_num], shared_ram_start);
565 while (code_len--) {
566 if (*code_start != iop_base[iop_num]->ram_data) {
567 return code_start;
569 code_start++;
571 return (__u8 *) 0;
575 * Handle an ISM IOP interrupt
578 irqreturn_t iop_ism_irq(int irq, void *dev_id)
580 uint iop_num = (uint) dev_id;
581 volatile struct mac_iop *iop = iop_base[iop_num];
582 int i,state;
584 #ifdef DEBUG_IOP
585 printk("iop_ism_irq: status = %02X\n", (uint) iop->status_ctrl);
586 #endif
588 /* INT0 indicates a state change on an outgoing message channel */
590 if (iop->status_ctrl & IOP_INT0) {
591 iop->status_ctrl = IOP_INT0 | IOP_RUN | IOP_AUTOINC;
592 #ifdef DEBUG_IOP
593 printk("iop_ism_irq: new status = %02X, send states",
594 (uint) iop->status_ctrl);
595 #endif
596 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
597 state = iop_readb(iop, IOP_ADDR_SEND_STATE + i);
598 #ifdef DEBUG_IOP
599 printk(" %02X", state);
600 #endif
601 if (state == IOP_MSG_COMPLETE) {
602 iop_handle_send(iop_num, i);
605 #ifdef DEBUG_IOP
606 printk("\n");
607 #endif
610 if (iop->status_ctrl & IOP_INT1) { /* INT1 for incoming msgs */
611 iop->status_ctrl = IOP_INT1 | IOP_RUN | IOP_AUTOINC;
612 #ifdef DEBUG_IOP
613 printk("iop_ism_irq: new status = %02X, recv states",
614 (uint) iop->status_ctrl);
615 #endif
616 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
617 state = iop_readb(iop, IOP_ADDR_RECV_STATE + i);
618 #ifdef DEBUG_IOP
619 printk(" %02X", state);
620 #endif
621 if (state == IOP_MSG_NEW) {
622 iop_handle_recv(iop_num, i);
625 #ifdef DEBUG_IOP
626 printk("\n");
627 #endif
629 return IRQ_HANDLED;