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Diffstat (limited to 'arch/m68k/mac/iop.c')
| -rw-r--r-- | arch/m68k/mac/iop.c | 623 |
1 files changed, 623 insertions, 0 deletions
diff --git a/arch/m68k/mac/iop.c b/arch/m68k/mac/iop.c new file mode 100644 index 000000000..4d2adfb32 --- /dev/null +++ b/arch/m68k/mac/iop.c @@ -0,0 +1,623 @@ +/* + * I/O Processor (IOP) management + * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org) + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice and this list of conditions. + * 2. Redistributions in binary form must reproduce the above copyright + * notice and this list of conditions in the documentation and/or other + * materials provided with the distribution. + */ + +/* + * The IOP chips are used in the IIfx and some Quadras (900, 950) to manage + * serial and ADB. They are actually a 6502 processor and some glue logic. + * + * 990429 (jmt) - Initial implementation, just enough to knock the SCC IOP + * into compatible mode so nobody has to fiddle with the + * Serial Switch control panel anymore. + * 990603 (jmt) - Added code to grab the correct ISM IOP interrupt for OSS + * and non-OSS machines (at least I hope it's correct on a + * non-OSS machine -- someone with a Q900 or Q950 needs to + * check this.) + * 990605 (jmt) - Rearranged things a bit wrt IOP detection; iop_present is + * gone, IOP base addresses are now in an array and the + * globally-visible functions take an IOP number instead of an + * an actual base address. + * 990610 (jmt) - Finished the message passing framework and it seems to work. + * Sending _definitely_ works; my adb-bus.c mods can send + * messages and receive the MSG_COMPLETED status back from the + * IOP. The trick now is figuring out the message formats. + * 990611 (jmt) - More cleanups. Fixed problem where unclaimed messages on a + * receive channel were never properly acknowledged. Bracketed + * the remaining debug printk's with #ifdef's and disabled + * debugging. I can now type on the console. + * 990612 (jmt) - Copyright notice added. Reworked the way replies are handled. + * It turns out that replies are placed back in the send buffer + * for that channel; messages on the receive channels are always + * unsolicited messages from the IOP (and our replies to them + * should go back in the receive channel.) Also added tracking + * of device names to the listener functions ala the interrupt + * handlers. + * 990729 (jmt) - Added passing of pt_regs structure to IOP handlers. This is + * used by the new unified ADB driver. + * + * TODO: + * + * o Something should be periodically checking iop_alive() to make sure the + * IOP hasn't died. + * o Some of the IOP manager routines need better error checking and + * return codes. Nothing major, just prettying up. + */ + +/* + * ----------------------- + * IOP Message Passing 101 + * ----------------------- + * + * The host talks to the IOPs using a rather simple message-passing scheme via + * a shared memory area in the IOP RAM. Each IOP has seven "channels"; each + * channel is conneced to a specific software driver on the IOP. For example + * on the SCC IOP there is one channel for each serial port. Each channel has + * an incoming and and outgoing message queue with a depth of one. + * + * A message is 32 bytes plus a state byte for the channel (MSG_IDLE, MSG_NEW, + * MSG_RCVD, MSG_COMPLETE). To send a message you copy the message into the + * buffer, set the state to MSG_NEW and signal the IOP by setting the IRQ flag + * in the IOP control to 1. The IOP will move the state to MSG_RCVD when it + * receives the message and then to MSG_COMPLETE when the message processing + * has completed. It is the host's responsibility at that point to read the + * reply back out of the send channel buffer and reset the channel state back + * to MSG_IDLE. + * + * To receive message from the IOP the same procedure is used except the roles + * are reversed. That is, the IOP puts message in the channel with a state of + * MSG_NEW, and the host receives the message and move its state to MSG_RCVD + * and then to MSG_COMPLETE when processing is completed and the reply (if any) + * has been placed back in the receive channel. The IOP will then reset the + * channel state to MSG_IDLE. + * + * Two sets of host interrupts are provided, INT0 and INT1. Both appear on one + * interrupt level; they are distinguished by a pair of bits in the IOP status + * register. The IOP will raise INT0 when one or more messages in the send + * channels have gone to the MSG_COMPLETE state and it will raise INT1 when one + * or more messages on the receive channels have gone to the MSG_NEW state. + * + * Since each channel handles only one message we have to implement a small + * interrupt-driven queue on our end. Messages to be sent are placed on the + * queue for sending and contain a pointer to an optional callback function. + * The handler for a message is called when the message state goes to + * MSG_COMPLETE. + * + * For receiving message we maintain a list of handler functions to call when + * a message is received on that IOP/channel combination. The handlers are + * called much like an interrupt handler and are passed a copy of the message + * from the IOP. The message state will be in MSG_RCVD while the handler runs; + * it is the handler's responsibility to call iop_complete_message() when + * finished; this function moves the message state to MSG_COMPLETE and signals + * the IOP. This two-step process is provided to allow the handler to defer + * message processing to a bottom-half handler if the processing will take + * a significant amount of time (handlers are called at interrupt time so they + * should execute quickly.) + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> + +#include <asm/macintosh.h> +#include <asm/macints.h> +#include <asm/mac_iop.h> + +/*#define DEBUG_IOP*/ + +/* Non-zero if the IOPs are present */ + +int iop_scc_present, iop_ism_present; + +/* structure for tracking channel listeners */ + +struct listener { + const char *devname; + void (*handler)(struct iop_msg *); +}; + +/* + * IOP structures for the two IOPs + * + * The SCC IOP controls both serial ports (A and B) as its two functions. + * The ISM IOP controls the SWIM (floppy drive) and ADB. + */ + +static volatile struct mac_iop *iop_base[NUM_IOPS]; + +/* + * IOP message queues + */ + +static struct iop_msg iop_msg_pool[NUM_IOP_MSGS]; +static struct iop_msg *iop_send_queue[NUM_IOPS][NUM_IOP_CHAN]; +static struct listener iop_listeners[NUM_IOPS][NUM_IOP_CHAN]; + +irqreturn_t iop_ism_irq(int, void *); + +/* + * Private access functions + */ + +static __inline__ void iop_loadaddr(volatile struct mac_iop *iop, __u16 addr) +{ + iop->ram_addr_lo = addr; + iop->ram_addr_hi = addr >> 8; +} + +static __inline__ __u8 iop_readb(volatile struct mac_iop *iop, __u16 addr) +{ + iop->ram_addr_lo = addr; + iop->ram_addr_hi = addr >> 8; + return iop->ram_data; +} + +static __inline__ void iop_writeb(volatile struct mac_iop *iop, __u16 addr, __u8 data) +{ + iop->ram_addr_lo = addr; + iop->ram_addr_hi = addr >> 8; + iop->ram_data = data; +} + +static __inline__ void iop_stop(volatile struct mac_iop *iop) +{ + iop->status_ctrl &= ~IOP_RUN; +} + +static __inline__ void iop_start(volatile struct mac_iop *iop) +{ + iop->status_ctrl = IOP_RUN | IOP_AUTOINC; +} + +static __inline__ void iop_bypass(volatile struct mac_iop *iop) +{ + iop->status_ctrl |= IOP_BYPASS; +} + +static __inline__ void iop_interrupt(volatile struct mac_iop *iop) +{ + iop->status_ctrl |= IOP_IRQ; +} + +static int iop_alive(volatile struct mac_iop *iop) +{ + int retval; + + retval = (iop_readb(iop, IOP_ADDR_ALIVE) == 0xFF); + iop_writeb(iop, IOP_ADDR_ALIVE, 0); + return retval; +} + +static struct iop_msg *iop_alloc_msg(void) +{ + int i; + unsigned long flags; + + local_irq_save(flags); + + for (i = 0 ; i < NUM_IOP_MSGS ; i++) { + if (iop_msg_pool[i].status == IOP_MSGSTATUS_UNUSED) { + iop_msg_pool[i].status = IOP_MSGSTATUS_WAITING; + local_irq_restore(flags); + return &iop_msg_pool[i]; + } + } + + local_irq_restore(flags); + return NULL; +} + +static void iop_free_msg(struct iop_msg *msg) +{ + msg->status = IOP_MSGSTATUS_UNUSED; +} + +/* + * This is called by the startup code before anything else. Its purpose + * is to find and initialize the IOPs early in the boot sequence, so that + * the serial IOP can be placed into bypass mode _before_ we try to + * initialize the serial console. + */ + +void __init iop_preinit(void) +{ + if (macintosh_config->scc_type == MAC_SCC_IOP) { + if (macintosh_config->ident == MAC_MODEL_IIFX) { + iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_IIFX; + } else { + iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA; + } + iop_base[IOP_NUM_SCC]->status_ctrl = 0x87; + iop_scc_present = 1; + } else { + iop_base[IOP_NUM_SCC] = NULL; + iop_scc_present = 0; + } + if (macintosh_config->adb_type == MAC_ADB_IOP) { + if (macintosh_config->ident == MAC_MODEL_IIFX) { + iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_IIFX; + } else { + iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_QUADRA; + } + iop_base[IOP_NUM_ISM]->status_ctrl = 0; + iop_ism_present = 1; + } else { + iop_base[IOP_NUM_ISM] = NULL; + iop_ism_present = 0; + } +} + +/* + * Initialize the IOPs, if present. + */ + +void __init iop_init(void) +{ + int i; + + if (iop_scc_present) { + printk("IOP: detected SCC IOP at %p\n", iop_base[IOP_NUM_SCC]); + } + if (iop_ism_present) { + printk("IOP: detected ISM IOP at %p\n", iop_base[IOP_NUM_ISM]); + iop_start(iop_base[IOP_NUM_ISM]); + iop_alive(iop_base[IOP_NUM_ISM]); /* clears the alive flag */ + } + + /* Make the whole pool available and empty the queues */ + + for (i = 0 ; i < NUM_IOP_MSGS ; i++) { + iop_msg_pool[i].status = IOP_MSGSTATUS_UNUSED; + } + + for (i = 0 ; i < NUM_IOP_CHAN ; i++) { + iop_send_queue[IOP_NUM_SCC][i] = NULL; + iop_send_queue[IOP_NUM_ISM][i] = NULL; + iop_listeners[IOP_NUM_SCC][i].devname = NULL; + iop_listeners[IOP_NUM_SCC][i].handler = NULL; + iop_listeners[IOP_NUM_ISM][i].devname = NULL; + iop_listeners[IOP_NUM_ISM][i].handler = NULL; + } +} + +/* + * Register the interrupt handler for the IOPs. + * TODO: might be wrong for non-OSS machines. Anyone? + */ + +void __init iop_register_interrupts(void) +{ + if (iop_ism_present) { + if (macintosh_config->ident == MAC_MODEL_IIFX) { + if (request_irq(IRQ_MAC_ADB, iop_ism_irq, 0, + "ISM IOP", (void *)IOP_NUM_ISM)) + pr_err("Couldn't register ISM IOP interrupt\n"); + } else { + if (request_irq(IRQ_VIA2_0, iop_ism_irq, 0, "ISM IOP", + (void *)IOP_NUM_ISM)) + pr_err("Couldn't register ISM IOP interrupt\n"); + } + if (!iop_alive(iop_base[IOP_NUM_ISM])) { + printk("IOP: oh my god, they killed the ISM IOP!\n"); + } else { + printk("IOP: the ISM IOP seems to be alive.\n"); + } + } +} + +/* + * Register or unregister a listener for a specific IOP and channel + * + * If the handler pointer is NULL the current listener (if any) is + * unregistered. Otherwise the new listener is registered provided + * there is no existing listener registered. + */ + +int iop_listen(uint iop_num, uint chan, + void (*handler)(struct iop_msg *), + const char *devname) +{ + if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL; + if (chan >= NUM_IOP_CHAN) return -EINVAL; + if (iop_listeners[iop_num][chan].handler && handler) return -EINVAL; + iop_listeners[iop_num][chan].devname = devname; + iop_listeners[iop_num][chan].handler = handler; + return 0; +} + +/* + * Complete reception of a message, which just means copying the reply + * into the buffer, setting the channel state to MSG_COMPLETE and + * notifying the IOP. + */ + +void iop_complete_message(struct iop_msg *msg) +{ + int iop_num = msg->iop_num; + int chan = msg->channel; + int i,offset; + +#ifdef DEBUG_IOP + printk("iop_complete(%p): iop %d chan %d\n", msg, msg->iop_num, msg->channel); +#endif + + offset = IOP_ADDR_RECV_MSG + (msg->channel * IOP_MSG_LEN); + + for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { + iop_writeb(iop_base[iop_num], offset, msg->reply[i]); + } + + iop_writeb(iop_base[iop_num], + IOP_ADDR_RECV_STATE + chan, IOP_MSG_COMPLETE); + iop_interrupt(iop_base[msg->iop_num]); + + iop_free_msg(msg); +} + +/* + * Actually put a message into a send channel buffer + */ + +static void iop_do_send(struct iop_msg *msg) +{ + volatile struct mac_iop *iop = iop_base[msg->iop_num]; + int i,offset; + + offset = IOP_ADDR_SEND_MSG + (msg->channel * IOP_MSG_LEN); + + for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { + iop_writeb(iop, offset, msg->message[i]); + } + + iop_writeb(iop, IOP_ADDR_SEND_STATE + msg->channel, IOP_MSG_NEW); + + iop_interrupt(iop); +} + +/* + * Handle sending a message on a channel that + * has gone into the IOP_MSG_COMPLETE state. + */ + +static void iop_handle_send(uint iop_num, uint chan) +{ + volatile struct mac_iop *iop = iop_base[iop_num]; + struct iop_msg *msg,*msg2; + int i,offset; + +#ifdef DEBUG_IOP + printk("iop_handle_send: iop %d channel %d\n", iop_num, chan); +#endif + + iop_writeb(iop, IOP_ADDR_SEND_STATE + chan, IOP_MSG_IDLE); + + if (!(msg = iop_send_queue[iop_num][chan])) return; + + msg->status = IOP_MSGSTATUS_COMPLETE; + offset = IOP_ADDR_SEND_MSG + (chan * IOP_MSG_LEN); + for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { + msg->reply[i] = iop_readb(iop, offset); + } + if (msg->handler) (*msg->handler)(msg); + msg2 = msg; + msg = msg->next; + iop_free_msg(msg2); + + iop_send_queue[iop_num][chan] = msg; + if (msg) iop_do_send(msg); +} + +/* + * Handle reception of a message on a channel that has + * gone into the IOP_MSG_NEW state. + */ + +static void iop_handle_recv(uint iop_num, uint chan) +{ + volatile struct mac_iop *iop = iop_base[iop_num]; + int i,offset; + struct iop_msg *msg; + +#ifdef DEBUG_IOP + printk("iop_handle_recv: iop %d channel %d\n", iop_num, chan); +#endif + + msg = iop_alloc_msg(); + msg->iop_num = iop_num; + msg->channel = chan; + msg->status = IOP_MSGSTATUS_UNSOL; + msg->handler = iop_listeners[iop_num][chan].handler; + + offset = IOP_ADDR_RECV_MSG + (chan * IOP_MSG_LEN); + + for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { + msg->message[i] = iop_readb(iop, offset); + } + + iop_writeb(iop, IOP_ADDR_RECV_STATE + chan, IOP_MSG_RCVD); + + /* If there is a listener, call it now. Otherwise complete */ + /* the message ourselves to avoid possible stalls. */ + + if (msg->handler) { + (*msg->handler)(msg); + } else { +#ifdef DEBUG_IOP + printk("iop_handle_recv: unclaimed message on iop %d channel %d\n", iop_num, chan); + printk("iop_handle_recv:"); + for (i = 0 ; i < IOP_MSG_LEN ; i++) { + printk(" %02X", (uint) msg->message[i]); + } + printk("\n"); +#endif + iop_complete_message(msg); + } +} + +/* + * Send a message + * + * The message is placed at the end of the send queue. Afterwards if the + * channel is idle we force an immediate send of the next message in the + * queue. + */ + +int iop_send_message(uint iop_num, uint chan, void *privdata, + uint msg_len, __u8 *msg_data, + void (*handler)(struct iop_msg *)) +{ + struct iop_msg *msg, *q; + + if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL; + if (chan >= NUM_IOP_CHAN) return -EINVAL; + if (msg_len > IOP_MSG_LEN) return -EINVAL; + + msg = iop_alloc_msg(); + if (!msg) return -ENOMEM; + + msg->next = NULL; + msg->status = IOP_MSGSTATUS_WAITING; + msg->iop_num = iop_num; + msg->channel = chan; + msg->caller_priv = privdata; + memcpy(msg->message, msg_data, msg_len); + msg->handler = handler; + + if (!(q = iop_send_queue[iop_num][chan])) { + iop_send_queue[iop_num][chan] = msg; + } else { + while (q->next) q = q->next; + q->next = msg; + } + + if (iop_readb(iop_base[iop_num], + IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) { + iop_do_send(msg); + } + + return 0; +} + +/* + * Upload code to the shared RAM of an IOP. + */ + +void iop_upload_code(uint iop_num, __u8 *code_start, + uint code_len, __u16 shared_ram_start) +{ + if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return; + + iop_loadaddr(iop_base[iop_num], shared_ram_start); + + while (code_len--) { + iop_base[iop_num]->ram_data = *code_start++; + } +} + +/* + * Download code from the shared RAM of an IOP. + */ + +void iop_download_code(uint iop_num, __u8 *code_start, + uint code_len, __u16 shared_ram_start) +{ + if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return; + + iop_loadaddr(iop_base[iop_num], shared_ram_start); + + while (code_len--) { + *code_start++ = iop_base[iop_num]->ram_data; + } +} + +/* + * Compare the code in the shared RAM of an IOP with a copy in system memory + * and return 0 on match or the first nonmatching system memory address on + * failure. + */ + +__u8 *iop_compare_code(uint iop_num, __u8 *code_start, + uint code_len, __u16 shared_ram_start) +{ + if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return code_start; + + iop_loadaddr(iop_base[iop_num], shared_ram_start); + + while (code_len--) { + if (*code_start != iop_base[iop_num]->ram_data) { + return code_start; + } + code_start++; + } + return (__u8 *) 0; +} + +/* + * Handle an ISM IOP interrupt + */ + +irqreturn_t iop_ism_irq(int irq, void *dev_id) +{ + uint iop_num = (uint) dev_id; + volatile struct mac_iop *iop = iop_base[iop_num]; + int i,state; + +#ifdef DEBUG_IOP + printk("iop_ism_irq: status = %02X\n", (uint) iop->status_ctrl); +#endif + + /* INT0 indicates a state change on an outgoing message channel */ + + if (iop->status_ctrl & IOP_INT0) { + iop->status_ctrl = IOP_INT0 | IOP_RUN | IOP_AUTOINC; +#ifdef DEBUG_IOP + printk("iop_ism_irq: new status = %02X, send states", + (uint) iop->status_ctrl); +#endif + for (i = 0 ; i < NUM_IOP_CHAN ; i++) { + state = iop_readb(iop, IOP_ADDR_SEND_STATE + i); +#ifdef DEBUG_IOP + printk(" %02X", state); +#endif + if (state == IOP_MSG_COMPLETE) { + iop_handle_send(iop_num, i); + } + } +#ifdef DEBUG_IOP + printk("\n"); +#endif + } + + if (iop->status_ctrl & IOP_INT1) { /* INT1 for incoming msgs */ + iop->status_ctrl = IOP_INT1 | IOP_RUN | IOP_AUTOINC; +#ifdef DEBUG_IOP + printk("iop_ism_irq: new status = %02X, recv states", + (uint) iop->status_ctrl); +#endif + for (i = 0 ; i < NUM_IOP_CHAN ; i++) { + state = iop_readb(iop, IOP_ADDR_RECV_STATE + i); +#ifdef DEBUG_IOP + printk(" %02X", state); +#endif + if (state == IOP_MSG_NEW) { + iop_handle_recv(iop_num, i); + } + } +#ifdef DEBUG_IOP + printk("\n"); +#endif + } + return IRQ_HANDLED; +} |