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 Something should be periodically checking iop_alive() to make sure the
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
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
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/proc_fs.h>
113 #include <linux/interrupt.h>
115 #include <asm/bootinfo.h>
116 #include <asm/macintosh.h>
117 #include <asm/macints.h>
118 #include <asm/mac_iop.h>
119 #include <asm/mac_oss.h>
121 /*#define DEBUG_IOP*/
123 /* Set to non-zero if the IOPs are present. Set by iop_init() */
125 int iop_scc_present,iop_ism_present;
127 #ifdef CONFIG_PROC_FS
128 static int iop_get_proc_info(char *, char **, off_t, int);
129 #endif /* CONFIG_PROC_FS */
131 /* structure for tracking channel listeners */
135 void (*handler)(struct iop_msg *);
139 * IOP structures for the two IOPs
141 * The SCC IOP controls both serial ports (A and B) as its two functions.
142 * The ISM IOP controls the SWIM (floppy drive) and ADB.
145 static volatile struct mac_iop *iop_base[NUM_IOPS];
151 static struct iop_msg iop_msg_pool[NUM_IOP_MSGS];
152 static struct iop_msg *iop_send_queue[NUM_IOPS][NUM_IOP_CHAN];
153 static struct listener iop_listeners[NUM_IOPS][NUM_IOP_CHAN];
155 irqreturn_t iop_ism_irq(int, void *);
157 extern void oss_irq_enable(int);
160 * Private access functions
163 static __inline__ void iop_loadaddr(volatile struct mac_iop *iop, __u16 addr)
165 iop->ram_addr_lo = addr;
166 iop->ram_addr_hi = addr >> 8;
169 static __inline__ __u8 iop_readb(volatile struct mac_iop *iop, __u16 addr)
171 iop->ram_addr_lo = addr;
172 iop->ram_addr_hi = addr >> 8;
173 return iop->ram_data;
176 static __inline__ void iop_writeb(volatile struct mac_iop *iop, __u16 addr, __u8 data)
178 iop->ram_addr_lo = addr;
179 iop->ram_addr_hi = addr >> 8;
180 iop->ram_data = data;
183 static __inline__ void iop_stop(volatile struct mac_iop *iop)
185 iop->status_ctrl &= ~IOP_RUN;
188 static __inline__ void iop_start(volatile struct mac_iop *iop)
190 iop->status_ctrl = IOP_RUN | IOP_AUTOINC;
193 static __inline__ void iop_bypass(volatile struct mac_iop *iop)
195 iop->status_ctrl |= IOP_BYPASS;
198 static __inline__ void iop_interrupt(volatile struct mac_iop *iop)
200 iop->status_ctrl |= IOP_IRQ;
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_alloc_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);
231 static void iop_free_msg(struct iop_msg *msg)
233 msg->status = IOP_MSGSTATUS_UNUSED;
237 * This is called by the startup code before anything else. Its purpose
238 * is to find and initialize the IOPs early in the boot sequence, so that
239 * the serial IOP can be placed into bypass mode _before_ we try to
240 * initialize the serial console.
243 void __init iop_preinit(void)
245 if (macintosh_config->scc_type == MAC_SCC_IOP) {
246 if (macintosh_config->ident == MAC_MODEL_IIFX) {
247 iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_IIFX;
249 iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA;
251 iop_base[IOP_NUM_SCC]->status_ctrl = 0x87;
254 iop_base[IOP_NUM_SCC] = NULL;
257 if (macintosh_config->adb_type == MAC_ADB_IOP) {
258 if (macintosh_config->ident == MAC_MODEL_IIFX) {
259 iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_IIFX;
261 iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_QUADRA;
263 iop_base[IOP_NUM_ISM]->status_ctrl = 0;
266 iop_base[IOP_NUM_ISM] = NULL;
272 * Initialize the IOPs, if present.
275 void __init iop_init(void)
279 if (iop_scc_present) {
280 printk("IOP: detected SCC IOP at %p\n", iop_base[IOP_NUM_SCC]);
282 if (iop_ism_present) {
283 printk("IOP: detected ISM IOP at %p\n", iop_base[IOP_NUM_ISM]);
284 iop_start(iop_base[IOP_NUM_ISM]);
285 iop_alive(iop_base[IOP_NUM_ISM]); /* clears the alive flag */
288 /* Make the whole pool available and empty the queues */
290 for (i = 0 ; i < NUM_IOP_MSGS ; i++) {
291 iop_msg_pool[i].status = IOP_MSGSTATUS_UNUSED;
294 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
295 iop_send_queue[IOP_NUM_SCC][i] = NULL;
296 iop_send_queue[IOP_NUM_ISM][i] = NULL;
297 iop_listeners[IOP_NUM_SCC][i].devname = NULL;
298 iop_listeners[IOP_NUM_SCC][i].handler = NULL;
299 iop_listeners[IOP_NUM_ISM][i].devname = NULL;
300 iop_listeners[IOP_NUM_ISM][i].handler = NULL;
303 #if 0 /* Crashing in 2.4 now, not yet sure why. --jmt */
304 #ifdef CONFIG_PROC_FS
305 create_proc_info_entry("mac_iop", 0, &proc_root, iop_get_proc_info);
311 * Register the interrupt handler for the IOPs.
312 * TODO: might be wrong for non-OSS machines. Anyone?
315 void __init iop_register_interrupts(void)
317 if (iop_ism_present) {
319 request_irq(OSS_IRQLEV_IOPISM, iop_ism_irq,
320 IRQ_FLG_LOCK, "ISM IOP",
321 (void *) IOP_NUM_ISM);
322 oss_irq_enable(IRQ_MAC_ADB);
324 request_irq(IRQ_VIA2_0, iop_ism_irq,
325 IRQ_FLG_LOCK|IRQ_FLG_FAST, "ISM IOP",
326 (void *) IOP_NUM_ISM);
328 if (!iop_alive(iop_base[IOP_NUM_ISM])) {
329 printk("IOP: oh my god, they killed the ISM IOP!\n");
331 printk("IOP: the ISM IOP seems to be alive.\n");
337 * Register or unregister a listener for a specific IOP and channel
339 * If the handler pointer is NULL the current listener (if any) is
340 * unregistered. Otherwise the new listener is registered provided
341 * there is no existing listener registered.
344 int iop_listen(uint iop_num, uint chan,
345 void (*handler)(struct iop_msg *),
348 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
349 if (chan >= NUM_IOP_CHAN) return -EINVAL;
350 if (iop_listeners[iop_num][chan].handler && handler) return -EINVAL;
351 iop_listeners[iop_num][chan].devname = devname;
352 iop_listeners[iop_num][chan].handler = handler;
357 * Complete reception of a message, which just means copying the reply
358 * into the buffer, setting the channel state to MSG_COMPLETE and
362 void iop_complete_message(struct iop_msg *msg)
364 int iop_num = msg->iop_num;
365 int chan = msg->channel;
369 printk("iop_complete(%p): iop %d chan %d\n", msg, msg->iop_num, msg->channel);
372 offset = IOP_ADDR_RECV_MSG + (msg->channel * IOP_MSG_LEN);
374 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
375 iop_writeb(iop_base[iop_num], offset, msg->reply[i]);
378 iop_writeb(iop_base[iop_num],
379 IOP_ADDR_RECV_STATE + chan, IOP_MSG_COMPLETE);
380 iop_interrupt(iop_base[msg->iop_num]);
386 * Actually put a message into a send channel buffer
389 static void iop_do_send(struct iop_msg *msg)
391 volatile struct mac_iop *iop = iop_base[msg->iop_num];
394 offset = IOP_ADDR_SEND_MSG + (msg->channel * IOP_MSG_LEN);
396 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
397 iop_writeb(iop, offset, msg->message[i]);
400 iop_writeb(iop, IOP_ADDR_SEND_STATE + msg->channel, IOP_MSG_NEW);
406 * Handle sending a message on a channel that
407 * has gone into the IOP_MSG_COMPLETE state.
410 static void iop_handle_send(uint iop_num, uint chan)
412 volatile struct mac_iop *iop = iop_base[iop_num];
413 struct iop_msg *msg,*msg2;
417 printk("iop_handle_send: iop %d channel %d\n", iop_num, chan);
420 iop_writeb(iop, IOP_ADDR_SEND_STATE + chan, IOP_MSG_IDLE);
422 if (!(msg = iop_send_queue[iop_num][chan])) return;
424 msg->status = IOP_MSGSTATUS_COMPLETE;
425 offset = IOP_ADDR_SEND_MSG + (chan * IOP_MSG_LEN);
426 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
427 msg->reply[i] = iop_readb(iop, offset);
429 if (msg->handler) (*msg->handler)(msg);
434 iop_send_queue[iop_num][chan] = msg;
435 if (msg) iop_do_send(msg);
439 * Handle reception of a message on a channel that has
440 * gone into the IOP_MSG_NEW state.
443 static void iop_handle_recv(uint iop_num, uint chan)
445 volatile struct mac_iop *iop = iop_base[iop_num];
450 printk("iop_handle_recv: iop %d channel %d\n", iop_num, chan);
453 msg = iop_alloc_msg();
454 msg->iop_num = iop_num;
456 msg->status = IOP_MSGSTATUS_UNSOL;
457 msg->handler = iop_listeners[iop_num][chan].handler;
459 offset = IOP_ADDR_RECV_MSG + (chan * IOP_MSG_LEN);
461 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
462 msg->message[i] = iop_readb(iop, offset);
465 iop_writeb(iop, IOP_ADDR_RECV_STATE + chan, IOP_MSG_RCVD);
467 /* If there is a listener, call it now. Otherwise complete */
468 /* the message ourselves to avoid possible stalls. */
471 (*msg->handler)(msg);
474 printk("iop_handle_recv: unclaimed message on iop %d channel %d\n", iop_num, chan);
475 printk("iop_handle_recv:");
476 for (i = 0 ; i < IOP_MSG_LEN ; i++) {
477 printk(" %02X", (uint) msg->message[i]);
481 iop_complete_message(msg);
488 * The message is placed at the end of the send queue. Afterwards if the
489 * channel is idle we force an immediate send of the next message in the
493 int iop_send_message(uint iop_num, uint chan, void *privdata,
494 uint msg_len, __u8 *msg_data,
495 void (*handler)(struct iop_msg *))
497 struct iop_msg *msg, *q;
499 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
500 if (chan >= NUM_IOP_CHAN) return -EINVAL;
501 if (msg_len > IOP_MSG_LEN) return -EINVAL;
503 msg = iop_alloc_msg();
504 if (!msg) return -ENOMEM;
507 msg->status = IOP_MSGSTATUS_WAITING;
508 msg->iop_num = iop_num;
510 msg->caller_priv = privdata;
511 memcpy(msg->message, msg_data, msg_len);
512 msg->handler = handler;
514 if (!(q = iop_send_queue[iop_num][chan])) {
515 iop_send_queue[iop_num][chan] = msg;
517 while (q->next) q = q->next;
521 if (iop_readb(iop_base[iop_num],
522 IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) {
530 * Upload code to the shared RAM of an IOP.
533 void iop_upload_code(uint iop_num, __u8 *code_start,
534 uint code_len, __u16 shared_ram_start)
536 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;
538 iop_loadaddr(iop_base[iop_num], shared_ram_start);
541 iop_base[iop_num]->ram_data = *code_start++;
546 * Download code from the shared RAM of an IOP.
549 void iop_download_code(uint iop_num, __u8 *code_start,
550 uint code_len, __u16 shared_ram_start)
552 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;
554 iop_loadaddr(iop_base[iop_num], shared_ram_start);
557 *code_start++ = iop_base[iop_num]->ram_data;
562 * Compare the code in the shared RAM of an IOP with a copy in system memory
563 * and return 0 on match or the first nonmatching system memory address on
567 __u8 *iop_compare_code(uint iop_num, __u8 *code_start,
568 uint code_len, __u16 shared_ram_start)
570 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return code_start;
572 iop_loadaddr(iop_base[iop_num], shared_ram_start);
575 if (*code_start != iop_base[iop_num]->ram_data) {
584 * Handle an ISM IOP interrupt
587 irqreturn_t iop_ism_irq(int irq, void *dev_id)
589 uint iop_num = (uint) dev_id;
590 volatile struct mac_iop *iop = iop_base[iop_num];
594 printk("iop_ism_irq: status = %02X\n", (uint) iop->status_ctrl);
597 /* INT0 indicates a state change on an outgoing message channel */
599 if (iop->status_ctrl & IOP_INT0) {
600 iop->status_ctrl = IOP_INT0 | IOP_RUN | IOP_AUTOINC;
602 printk("iop_ism_irq: new status = %02X, send states",
603 (uint) iop->status_ctrl);
605 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
606 state = iop_readb(iop, IOP_ADDR_SEND_STATE + i);
608 printk(" %02X", state);
610 if (state == IOP_MSG_COMPLETE) {
611 iop_handle_send(iop_num, i);
619 if (iop->status_ctrl & IOP_INT1) { /* INT1 for incoming msgs */
620 iop->status_ctrl = IOP_INT1 | IOP_RUN | IOP_AUTOINC;
622 printk("iop_ism_irq: new status = %02X, recv states",
623 (uint) iop->status_ctrl);
625 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
626 state = iop_readb(iop, IOP_ADDR_RECV_STATE + i);
628 printk(" %02X", state);
630 if (state == IOP_MSG_NEW) {
631 iop_handle_recv(iop_num, i);
641 #ifdef CONFIG_PROC_FS
643 char *iop_chan_state(int state)
646 case IOP_MSG_IDLE : return "idle ";
647 case IOP_MSG_NEW : return "new ";
648 case IOP_MSG_RCVD : return "received ";
649 case IOP_MSG_COMPLETE : return "completed ";
650 default : return "unknown ";
654 int iop_dump_one_iop(char *buf, int iop_num, char *iop_name)
657 volatile struct mac_iop *iop = iop_base[iop_num];
659 len += sprintf(buf+len, "%s IOP channel states:\n\n", iop_name);
660 len += sprintf(buf+len, "## send_state recv_state device\n");
661 len += sprintf(buf+len, "------------------------------------------------\n");
662 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
663 len += sprintf(buf+len, "%2d %10s %10s %s\n", i,
664 iop_chan_state(iop_readb(iop, IOP_ADDR_SEND_STATE+i)),
665 iop_chan_state(iop_readb(iop, IOP_ADDR_RECV_STATE+i)),
666 iop_listeners[iop_num][i].handler?
667 iop_listeners[iop_num][i].devname : "");
670 len += sprintf(buf+len, "\n");
674 static int iop_get_proc_info(char *buf, char **start, off_t pos, int count)
679 len = sprintf(buf, "IOPs detected:\n\n");
681 if (iop_scc_present) {
682 len += sprintf(buf+len, "SCC IOP (%p): status %02X\n",
683 iop_base[IOP_NUM_SCC],
684 (uint) iop_base[IOP_NUM_SCC]->status_ctrl);
686 if (iop_ism_present) {
687 len += sprintf(buf+len, "ISM IOP (%p): status %02X\n\n",
688 iop_base[IOP_NUM_ISM],
689 (uint) iop_base[IOP_NUM_ISM]->status_ctrl);
692 if (iop_scc_present) {
693 len += iop_dump_one_iop(buf+len, IOP_NUM_SCC, "SCC");
697 if (iop_ism_present) {
698 len += iop_dump_one_iop(buf+len, IOP_NUM_ISM, "ISM");
710 return (count > cnt) ? cnt : count;
713 #endif /* CONFIG_PROC_FS */