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 connected 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/interrupt.h>
114 #include <asm/macintosh.h>
115 #include <asm/macints.h>
116 #include <asm/mac_iop.h>
119 #define iop_pr_debug(fmt, ...) \
120 printk(KERN_DEBUG "%s: " fmt, __func__, ##__VA_ARGS__)
121 #define iop_pr_cont(fmt, ...) \
122 printk(KERN_CONT fmt, ##__VA_ARGS__)
124 #define iop_pr_debug(fmt, ...) \
125 no_printk(KERN_DEBUG "%s: " fmt, __func__, ##__VA_ARGS__)
126 #define iop_pr_cont(fmt, ...) \
127 no_printk(KERN_CONT fmt, ##__VA_ARGS__)
130 /* Non-zero if the IOPs are present */
132 int iop_scc_present, iop_ism_present;
134 /* structure for tracking channel listeners */
138 void (*handler)(struct iop_msg *);
142 * IOP structures for the two IOPs
144 * The SCC IOP controls both serial ports (A and B) as its two functions.
145 * The ISM IOP controls the SWIM (floppy drive) and ADB.
148 static volatile struct mac_iop *iop_base[NUM_IOPS];
154 static struct iop_msg iop_msg_pool[NUM_IOP_MSGS];
155 static struct iop_msg *iop_send_queue[NUM_IOPS][NUM_IOP_CHAN];
156 static struct listener iop_listeners[NUM_IOPS][NUM_IOP_CHAN];
158 irqreturn_t iop_ism_irq(int, void *);
161 * Private access functions
164 static __inline__ void iop_loadaddr(volatile struct mac_iop *iop, __u16 addr)
166 iop->ram_addr_lo = addr;
167 iop->ram_addr_hi = addr >> 8;
170 static __inline__ __u8 iop_readb(volatile struct mac_iop *iop, __u16 addr)
172 iop->ram_addr_lo = addr;
173 iop->ram_addr_hi = addr >> 8;
174 return iop->ram_data;
177 static __inline__ void iop_writeb(volatile struct mac_iop *iop, __u16 addr, __u8 data)
179 iop->ram_addr_lo = addr;
180 iop->ram_addr_hi = addr >> 8;
181 iop->ram_data = data;
184 static __inline__ void iop_stop(volatile struct mac_iop *iop)
186 iop->status_ctrl = IOP_AUTOINC;
189 static __inline__ void iop_start(volatile struct mac_iop *iop)
191 iop->status_ctrl = IOP_RUN | IOP_AUTOINC;
194 static __inline__ void iop_interrupt(volatile struct mac_iop *iop)
196 iop->status_ctrl = IOP_IRQ | IOP_RUN | IOP_AUTOINC;
199 static int iop_alive(volatile struct mac_iop *iop)
203 retval = (iop_readb(iop, IOP_ADDR_ALIVE) == 0xFF);
204 iop_writeb(iop, IOP_ADDR_ALIVE, 0);
208 static struct iop_msg *iop_get_unused_msg(void)
213 local_irq_save(flags);
215 for (i = 0 ; i < NUM_IOP_MSGS ; i++) {
216 if (iop_msg_pool[i].status == IOP_MSGSTATUS_UNUSED) {
217 iop_msg_pool[i].status = IOP_MSGSTATUS_WAITING;
218 local_irq_restore(flags);
219 return &iop_msg_pool[i];
223 local_irq_restore(flags);
228 * This is called by the startup code before anything else. Its purpose
229 * is to find and initialize the IOPs early in the boot sequence, so that
230 * the serial IOP can be placed into bypass mode _before_ we try to
231 * initialize the serial console.
234 void __init iop_preinit(void)
236 if (macintosh_config->scc_type == MAC_SCC_IOP) {
237 if (macintosh_config->ident == MAC_MODEL_IIFX) {
238 iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_IIFX;
240 iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA;
244 iop_base[IOP_NUM_SCC] = NULL;
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 iop_stop(iop_base[IOP_NUM_ISM]);
256 iop_base[IOP_NUM_ISM] = NULL;
262 * Initialize the IOPs, if present.
265 void __init iop_init(void)
269 if (iop_scc_present) {
270 pr_debug("SCC IOP detected at %p\n", iop_base[IOP_NUM_SCC]);
272 if (iop_ism_present) {
273 pr_debug("ISM IOP detected at %p\n", iop_base[IOP_NUM_ISM]);
274 iop_start(iop_base[IOP_NUM_ISM]);
275 iop_alive(iop_base[IOP_NUM_ISM]); /* clears the alive flag */
278 /* Make the whole pool available and empty the queues */
280 for (i = 0 ; i < NUM_IOP_MSGS ; i++) {
281 iop_msg_pool[i].status = IOP_MSGSTATUS_UNUSED;
284 for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
285 iop_send_queue[IOP_NUM_SCC][i] = NULL;
286 iop_send_queue[IOP_NUM_ISM][i] = NULL;
287 iop_listeners[IOP_NUM_SCC][i].devname = NULL;
288 iop_listeners[IOP_NUM_SCC][i].handler = NULL;
289 iop_listeners[IOP_NUM_ISM][i].devname = NULL;
290 iop_listeners[IOP_NUM_ISM][i].handler = NULL;
295 * Register the interrupt handler for the IOPs.
298 void __init iop_register_interrupts(void)
300 if (iop_ism_present) {
301 if (macintosh_config->ident == MAC_MODEL_IIFX) {
302 if (request_irq(IRQ_MAC_ADB, iop_ism_irq, 0,
303 "ISM IOP", (void *)IOP_NUM_ISM))
304 pr_err("Couldn't register ISM IOP interrupt\n");
306 if (request_irq(IRQ_VIA2_0, iop_ism_irq, 0, "ISM IOP",
307 (void *)IOP_NUM_ISM))
308 pr_err("Couldn't register ISM IOP interrupt\n");
310 if (!iop_alive(iop_base[IOP_NUM_ISM])) {
311 pr_warn("IOP: oh my god, they killed the ISM IOP!\n");
313 pr_warn("IOP: the ISM IOP seems to be alive.\n");
319 * Register or unregister a listener for a specific IOP and channel
321 * If the handler pointer is NULL the current listener (if any) is
322 * unregistered. Otherwise the new listener is registered provided
323 * there is no existing listener registered.
326 int iop_listen(uint iop_num, uint chan,
327 void (*handler)(struct iop_msg *),
330 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
331 if (chan >= NUM_IOP_CHAN) return -EINVAL;
332 if (iop_listeners[iop_num][chan].handler && handler) return -EINVAL;
333 iop_listeners[iop_num][chan].devname = devname;
334 iop_listeners[iop_num][chan].handler = handler;
339 * Complete reception of a message, which just means copying the reply
340 * into the buffer, setting the channel state to MSG_COMPLETE and
344 void iop_complete_message(struct iop_msg *msg)
346 int iop_num = msg->iop_num;
347 int chan = msg->channel;
350 iop_pr_debug("iop_num %d chan %d reply %*ph\n",
351 msg->iop_num, msg->channel, IOP_MSG_LEN, msg->reply);
353 offset = IOP_ADDR_RECV_MSG + (msg->channel * IOP_MSG_LEN);
355 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
356 iop_writeb(iop_base[iop_num], offset, msg->reply[i]);
359 iop_writeb(iop_base[iop_num],
360 IOP_ADDR_RECV_STATE + chan, IOP_MSG_COMPLETE);
361 iop_interrupt(iop_base[msg->iop_num]);
363 msg->status = IOP_MSGSTATUS_UNUSED;
367 * Actually put a message into a send channel buffer
370 static void iop_do_send(struct iop_msg *msg)
372 volatile struct mac_iop *iop = iop_base[msg->iop_num];
375 iop_pr_debug("iop_num %d chan %d message %*ph\n",
376 msg->iop_num, msg->channel, IOP_MSG_LEN, msg->message);
378 offset = IOP_ADDR_SEND_MSG + (msg->channel * IOP_MSG_LEN);
380 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
381 iop_writeb(iop, offset, msg->message[i]);
384 iop_writeb(iop, IOP_ADDR_SEND_STATE + msg->channel, IOP_MSG_NEW);
390 * Handle sending a message on a channel that
391 * has gone into the IOP_MSG_COMPLETE state.
394 static void iop_handle_send(uint iop_num, uint chan)
396 volatile struct mac_iop *iop = iop_base[iop_num];
400 iop_writeb(iop, IOP_ADDR_SEND_STATE + chan, IOP_MSG_IDLE);
402 if (!(msg = iop_send_queue[iop_num][chan])) return;
404 msg->status = IOP_MSGSTATUS_COMPLETE;
405 offset = IOP_ADDR_SEND_MSG + (chan * IOP_MSG_LEN);
406 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
407 msg->reply[i] = iop_readb(iop, offset);
409 iop_pr_debug("iop_num %d chan %d reply %*ph\n",
410 iop_num, chan, IOP_MSG_LEN, msg->reply);
412 if (msg->handler) (*msg->handler)(msg);
413 msg->status = IOP_MSGSTATUS_UNUSED;
415 iop_send_queue[iop_num][chan] = msg;
416 if (msg && iop_readb(iop, IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE)
421 * Handle reception of a message on a channel that has
422 * gone into the IOP_MSG_NEW state.
425 static void iop_handle_recv(uint iop_num, uint chan)
427 volatile struct mac_iop *iop = iop_base[iop_num];
431 msg = iop_get_unused_msg();
432 msg->iop_num = iop_num;
434 msg->status = IOP_MSGSTATUS_UNSOL;
435 msg->handler = iop_listeners[iop_num][chan].handler;
437 offset = IOP_ADDR_RECV_MSG + (chan * IOP_MSG_LEN);
439 for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
440 msg->message[i] = iop_readb(iop, offset);
442 iop_pr_debug("iop_num %d chan %d message %*ph\n",
443 iop_num, chan, IOP_MSG_LEN, msg->message);
445 iop_writeb(iop, IOP_ADDR_RECV_STATE + chan, IOP_MSG_RCVD);
447 /* If there is a listener, call it now. Otherwise complete */
448 /* the message ourselves to avoid possible stalls. */
451 (*msg->handler)(msg);
453 memset(msg->reply, 0, IOP_MSG_LEN);
454 iop_complete_message(msg);
461 * The message is placed at the end of the send queue. Afterwards if the
462 * channel is idle we force an immediate send of the next message in the
466 int iop_send_message(uint iop_num, uint chan, void *privdata,
467 uint msg_len, __u8 *msg_data,
468 void (*handler)(struct iop_msg *))
470 struct iop_msg *msg, *q;
472 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
473 if (chan >= NUM_IOP_CHAN) return -EINVAL;
474 if (msg_len > IOP_MSG_LEN) return -EINVAL;
476 msg = iop_get_unused_msg();
477 if (!msg) return -ENOMEM;
480 msg->status = IOP_MSGSTATUS_WAITING;
481 msg->iop_num = iop_num;
483 msg->caller_priv = privdata;
484 memcpy(msg->message, msg_data, msg_len);
485 msg->handler = handler;
487 if (!(q = iop_send_queue[iop_num][chan])) {
488 iop_send_queue[iop_num][chan] = msg;
491 while (q->next) q = q->next;
499 * Upload code to the shared RAM of an IOP.
502 void iop_upload_code(uint iop_num, __u8 *code_start,
503 uint code_len, __u16 shared_ram_start)
505 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;
507 iop_loadaddr(iop_base[iop_num], shared_ram_start);
510 iop_base[iop_num]->ram_data = *code_start++;
515 * Download code from the shared RAM of an IOP.
518 void iop_download_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;
523 iop_loadaddr(iop_base[iop_num], shared_ram_start);
526 *code_start++ = iop_base[iop_num]->ram_data;
531 * Compare the code in the shared RAM of an IOP with a copy in system memory
532 * and return 0 on match or the first nonmatching system memory address on
536 __u8 *iop_compare_code(uint iop_num, __u8 *code_start,
537 uint code_len, __u16 shared_ram_start)
539 if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return code_start;
541 iop_loadaddr(iop_base[iop_num], shared_ram_start);
544 if (*code_start != iop_base[iop_num]->ram_data) {
553 * Handle an ISM IOP interrupt
556 irqreturn_t iop_ism_irq(int irq, void *dev_id)
558 uint iop_num = (uint) dev_id;
559 volatile struct mac_iop *iop = iop_base[iop_num];
561 u8 events = iop->status_ctrl & (IOP_INT0 | IOP_INT1);
564 iop_pr_debug("iop_num %d status %02X\n", iop_num,
567 /* INT0 indicates state change on an outgoing message channel */
568 if (events & IOP_INT0) {
569 iop->status_ctrl = IOP_INT0 | IOP_RUN | IOP_AUTOINC;
570 for (i = 0; i < NUM_IOP_CHAN; i++) {
571 state = iop_readb(iop, IOP_ADDR_SEND_STATE + i);
572 if (state == IOP_MSG_COMPLETE)
573 iop_handle_send(iop_num, i);
574 else if (state != IOP_MSG_IDLE)
575 iop_pr_debug("chan %d send state %02X\n",
580 /* INT1 for incoming messages */
581 if (events & IOP_INT1) {
582 iop->status_ctrl = IOP_INT1 | IOP_RUN | IOP_AUTOINC;
583 for (i = 0; i < NUM_IOP_CHAN; i++) {
584 state = iop_readb(iop, IOP_ADDR_RECV_STATE + i);
585 if (state == IOP_MSG_NEW)
586 iop_handle_recv(iop_num, i);
587 else if (state != IOP_MSG_IDLE)
588 iop_pr_debug("chan %d recv state %02X\n",
593 events = iop->status_ctrl & (IOP_INT0 | IOP_INT1);
599 void iop_ism_irq_poll(uint iop_num)
603 local_irq_save(flags);
604 iop_ism_irq(0, (void *)iop_num);
605 local_irq_restore(flags);