/* * Device driver for the via ADB on (many) Mac II-class machines * * Based on the original ADB keyboard handler Copyright (c) 1997 Alan Cox * Also derived from code Copyright (C) 1996 Paul Mackerras. * * With various updates provided over the years by Michael Schmitz, * Guideo Koerber and others. * * Rewrite for Unified ADB by Joshua M. Thompson (funaho@jurai.org) * * 1999-08-02 (jmt) - Initial rewrite for Unified ADB. * 2000-03-29 Tony Mantler <tonym@mac.linux-m68k.org> * - Big overhaul, should actually work now. */ #include <stdarg.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/sched.h> #include <linux/adb.h> #include <linux/interrupt.h> #include <linux/init.h> #include <asm/macintosh.h> #include <asm/macints.h> #include <asm/machw.h> #include <asm/mac_via.h> #include <asm/io.h> #include <asm/system.h> static volatile unsigned char *via; /* VIA registers - spaced 0x200 bytes apart */ #define RS 0x200 /* skip between registers */ #define B 0 /* B-side data */ #define A RS /* A-side data */ #define DIRB (2*RS) /* B-side direction (1=output) */ #define DIRA (3*RS) /* A-side direction (1=output) */ #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ #define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */ #define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */ #define SR (10*RS) /* Shift register */ #define ACR (11*RS) /* Auxiliary control register */ #define PCR (12*RS) /* Peripheral control register */ #define IFR (13*RS) /* Interrupt flag register */ #define IER (14*RS) /* Interrupt enable register */ #define ANH (15*RS) /* A-side data, no handshake */ /* Bits in B data register: all active low */ #define TREQ 0x08 /* Transfer request (input) */ #define TACK 0x10 /* Transfer acknowledge (output) */ #define TIP 0x20 /* Transfer in progress (output) */ #define ST_MASK 0x30 /* mask for selecting ADB state bits */ /* Bits in ACR */ #define SR_CTRL 0x1c /* Shift register control bits */ #define SR_EXT 0x0c /* Shift on external clock */ #define SR_OUT 0x10 /* Shift out if 1 */ /* Bits in IFR and IER */ #define IER_SET 0x80 /* set bits in IER */ #define IER_CLR 0 /* clear bits in IER */ #define SR_INT 0x04 /* Shift register full/empty */ #define SR_DATA 0x08 /* Shift register data */ #define SR_CLOCK 0x10 /* Shift register clock */ /* ADB transaction states according to GMHW */ #define ST_CMD 0x00 /* ADB state: command byte */ #define ST_EVEN 0x10 /* ADB state: even data byte */ #define ST_ODD 0x20 /* ADB state: odd data byte */ #define ST_IDLE 0x30 /* ADB state: idle, nothing to send */ static int macii_init_via(void); static void macii_start(void); static irqreturn_t macii_interrupt(int irq, void *arg, struct pt_regs *regs); static void macii_retransmit(int); static void macii_queue_poll(void); static int macii_probe(void); static int macii_init(void); static int macii_send_request(struct adb_request *req, int sync); static int macii_write(struct adb_request *req); static int macii_autopoll(int devs); static void macii_poll(void); static int macii_reset_bus(void); struct adb_driver via_macii_driver = { "Mac II", macii_probe, macii_init, macii_send_request, macii_autopoll, macii_poll, macii_reset_bus }; static enum macii_state { idle, sending, reading, read_done, awaiting_reply } macii_state; static int need_poll = 0; static int command_byte = 0; static int last_reply = 0; static int last_active = 0; static struct adb_request *current_req; static struct adb_request *last_req; static struct adb_request *retry_req; static unsigned char reply_buf[16]; static unsigned char *reply_ptr; static int reply_len; static int reading_reply; static int data_index; static int first_byte; static int prefix_len; static int status = ST_IDLE|TREQ; static int last_status; static int driver_running = 0; /* debug level 10 required for ADB logging (should be && debug_adb, ideally) */ /* Check for MacII style ADB */ static int macii_probe(void) { if (macintosh_config->adb_type != MAC_ADB_II) return -ENODEV; via = via1; printk("adb: Mac II ADB Driver v1.0 for Unified ADB\n"); return 0; } /* Initialize the driver */ int macii_init(void) { unsigned long flags; int err; local_irq_save(flags); err = macii_init_via(); if (err) return err; err = request_irq(IRQ_MAC_ADB, macii_interrupt, IRQ_FLG_LOCK, "ADB", macii_interrupt); if (err) return err; macii_state = idle; local_irq_restore(flags); return 0; } /* initialize the hardware */ static int macii_init_via(void) { unsigned char x; /* Set the lines up. We want TREQ as input TACK|TIP as output */ via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ; /* Set up state: idle */ via[B] |= ST_IDLE; last_status = via[B] & (ST_MASK|TREQ); /* Shift register on input */ via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT; /* Wipe any pending data and int */ x = via[SR]; return 0; } /* Send an ADB poll (Talk Register 0 command, tagged on the front of the request queue) */ static void macii_queue_poll(void) { static int device = 0; static int in_poll=0; static struct adb_request req; unsigned long flags; if (in_poll) printk("macii_queue_poll: double poll!\n"); in_poll++; if (++device > 15) device = 1; adb_request(&req, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1, ADB_READREG(device, 0)); local_irq_save(flags); req.next = current_req; current_req = &req; local_irq_restore(flags); macii_start(); in_poll--; } /* Send an ADB retransmit (Talk, appended to the request queue) */ static void macii_retransmit(int device) { static int in_retransmit = 0; static struct adb_request rt; unsigned long flags; if (in_retransmit) printk("macii_retransmit: double retransmit!\n"); in_retransmit++; adb_request(&rt, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1, ADB_READREG(device, 0)); local_irq_save(flags); if (current_req != NULL) { last_req->next = &rt; last_req = &rt; } else { current_req = &rt; last_req = &rt; } if (macii_state == idle) macii_start(); local_irq_restore(flags); in_retransmit--; } /* Send an ADB request; if sync, poll out the reply 'till it's done */ static int macii_send_request(struct adb_request *req, int sync) { int i; i = macii_write(req); if (i) return i; if (sync) { while (!req->complete) macii_poll(); } return 0; } /* Send an ADB request */ static int macii_write(struct adb_request *req) { unsigned long flags; if (req->nbytes < 2 || req->data[0] != ADB_PACKET || req->nbytes > 15) { req->complete = 1; return -EINVAL; } req->next = 0; req->sent = 0; req->complete = 0; req->reply_len = 0; local_irq_save(flags); if (current_req != NULL) { last_req->next = req; last_req = req; } else { current_req = req; last_req = req; if (macii_state == idle) macii_start(); } local_irq_restore(flags); return 0; } /* Start auto-polling */ static int macii_autopoll(int devs) { /* Just ping a random default address */ if (!(current_req || retry_req)) macii_retransmit( (last_active < 16 && last_active > 0) ? last_active : 3); return 0; } /* Prod the chip without interrupts */ static void macii_poll(void) { unsigned long flags; local_irq_save(flags); if (via[IFR] & SR_INT) macii_interrupt(0, 0, 0); local_irq_restore(flags); } /* Reset the bus */ static int macii_reset_bus(void) { static struct adb_request req; /* Command = 0, Address = ignored */ adb_request(&req, NULL, 0, 1, ADB_BUSRESET); return 0; } /* Start sending ADB packet */ static void macii_start(void) { unsigned long flags; struct adb_request *req; req = current_req; if (!req) return; /* assert macii_state == idle */ if (macii_state != idle) { printk("macii_start: called while driver busy (%p %x %x)!\n", req, macii_state, (uint) via1[B] & (ST_MASK|TREQ)); return; } local_irq_save(flags); /* * IRQ signaled ?? (means ADB controller wants to send, or might * be end of packet if we were reading) */ #if 0 /* FIXME: This is broke broke broke, for some reason */ if ((via[B] & TREQ) == 0) { printk("macii_start: weird poll stuff. huh?\n"); /* * FIXME - we need to restart this on a timer * or a collision at boot hangs us. * Never set macii_state to idle here, or macii_start * won't be called again from send_request! * (need to re-check other cases ...) */ /* * if the interrupt handler set the need_poll * flag, it's hopefully a SRQ poll or re-Talk * so we try to send here anyway */ if (!need_poll) { if (console_loglevel == 10) printk("macii_start: device busy - retry %p state %d status %x!\n", req, macii_state, (uint) via[B] & (ST_MASK|TREQ)); retry_req = req; /* set ADB status here ? */ local_irq_restore(flags); return; } else { need_poll = 0; } } #endif /* * Another retry pending? (sanity check) */ if (retry_req) { retry_req = NULL; } /* Now send it. Be careful though, that first byte of the request */ /* is actually ADB_PACKET; the real data begins at index 1! */ /* store command byte */ command_byte = req->data[1]; /* Output mode */ via[ACR] |= SR_OUT; /* Load data */ via[SR] = req->data[1]; /* set ADB state to 'command' */ via[B] = (via[B] & ~ST_MASK) | ST_CMD; macii_state = sending; data_index = 2; local_irq_restore(flags); } /* * The notorious ADB interrupt handler - does all of the protocol handling, * except for starting new send operations. Relies heavily on the ADB * controller sending and receiving data, thereby generating SR interrupts * for us. This means there has to be always activity on the ADB bus, otherwise * the whole process dies and has to be re-kicked by sending TALK requests ... * CUDA-based Macs seem to solve this with the autopoll option, for MacII-type * ADB the problem isn't solved yet (retransmit of the latest active TALK seems * a good choice; either on timeout or on a timer interrupt). * * The basic ADB state machine was left unchanged from the original MacII code * by Alan Cox, which was based on the CUDA driver for PowerMac. * The syntax of the ADB status lines seems to be totally different on MacII, * though. MacII uses the states Command -> Even -> Odd -> Even ->...-> Idle for * sending, and Idle -> Even -> Odd -> Even ->...-> Idle for receiving. Start * and end of a receive packet are signaled by asserting /IRQ on the interrupt * line. Timeouts are signaled by a sequence of 4 0xFF, with /IRQ asserted on * every other byte. SRQ is probably signaled by 3 or more 0xFF tacked on the * end of a packet. (Thanks to Guido Koerber for eavesdropping on the ADB * protocol with a logic analyzer!!) * * Note: As of 21/10/97, the MacII ADB part works including timeout detection * and retransmit (Talk to the last active device). */ static irqreturn_t macii_interrupt(int irq, void *arg, struct pt_regs *regs) { int x, adbdir; unsigned long flags; struct adb_request *req; last_status = status; /* prevent races due to SCSI enabling ints */ local_irq_save(flags); if (driver_running) { local_irq_restore(flags); return IRQ_NONE; } driver_running = 1; status = via[B] & (ST_MASK|TREQ); adbdir = via[ACR] & SR_OUT; switch (macii_state) { case idle: x = via[SR]; first_byte = x; /* set ADB state = even for first data byte */ via[B] = (via[B] & ~ST_MASK) | ST_EVEN; reply_buf[0] = first_byte; /* was command_byte?? */ reply_ptr = reply_buf + 1; reply_len = 1; prefix_len = 1; reading_reply = 0; macii_state = reading; break; case awaiting_reply: /* handshake etc. for II ?? */ x = via[SR]; first_byte = x; /* set ADB state = even for first data byte */ via[B] = (via[B] & ~ST_MASK) | ST_EVEN; current_req->reply[0] = first_byte; reply_ptr = current_req->reply + 1; reply_len = 1; prefix_len = 1; reading_reply = 1; macii_state = reading; break; case sending: req = current_req; if (data_index >= req->nbytes) { /* print an error message if a listen command has no data */ if (((command_byte & 0x0C) == 0x08) /* && (console_loglevel == 10) */ && (data_index == 2)) printk("MacII ADB: listen command with no data: %x!\n", command_byte); /* reset to shift in */ via[ACR] &= ~SR_OUT; x = via[SR]; /* set ADB state idle - might get SRQ */ via[B] = (via[B] & ~ST_MASK) | ST_IDLE; req->sent = 1; if (req->reply_expected) { macii_state = awaiting_reply; } else { req->complete = 1; current_req = req->next; if (req->done) (*req->done)(req); macii_state = idle; if (current_req || retry_req) macii_start(); else macii_retransmit((command_byte & 0xF0) >> 4); } } else { via[SR] = req->data[data_index++]; if ( (via[B] & ST_MASK) == ST_CMD ) { /* just sent the command byte, set to EVEN */ via[B] = (via[B] & ~ST_MASK) | ST_EVEN; } else { /* invert state bits, toggle ODD/EVEN */ via[B] ^= ST_MASK; } } break; case reading: /* timeout / SRQ handling for II hw */ if( (first_byte == 0xFF && (reply_len-prefix_len)==2 && memcmp(reply_ptr-2,"\xFF\xFF",2)==0) || ((reply_len-prefix_len)==3 && memcmp(reply_ptr-3,"\xFF\xFF\xFF",3)==0)) { /* * possible timeout (in fact, most probably a * timeout, since SRQ can't be signaled without * transfer on the bus). * The last three bytes seen were FF, together * with the starting byte (in case we started * on 'idle' or 'awaiting_reply') this probably * makes four. So this is mostl likely #5! * The timeout signal is a pattern 1 0 1 0 0.. * on /INT, meaning we missed it :-( */ x = via[SR]; if (x != 0xFF) printk("MacII ADB: mistaken timeout/SRQ!\n"); if ((status & TREQ) == (last_status & TREQ)) { /* Not a timeout. Unsolicited SRQ? weird. */ /* Terminate the SRQ packet and poll */ need_poll = 1; } /* There's no packet to get, so reply is blank */ via[B] ^= ST_MASK; reply_ptr -= (reply_len-prefix_len); reply_len = prefix_len; macii_state = read_done; break; } /* end timeout / SRQ handling for II hw. */ if((reply_len-prefix_len)>3 && memcmp(reply_ptr-3,"\xFF\xFF\xFF",3)==0) { /* SRQ tacked on data packet */ /* Terminate the packet (SRQ never ends) */ x = via[SR]; macii_state = read_done; reply_len -= 3; reply_ptr -= 3; need_poll = 1; /* need to continue; next byte not seen else */ } else { /* Sanity check */ if (reply_len > 15) reply_len = 0; /* read byte */ x = via[SR]; *reply_ptr = x; reply_ptr++; reply_len++; } /* The usual handshake ... */ /* * NetBSD hints that the next to last byte * is sent with IRQ !! * Guido found out it's the last one (0x0), * but IRQ should be asserted already. * Problem with timeout detection: First * transition to /IRQ might be second * byte of timeout packet! * Timeouts are signaled by 4x FF. */ if (((status & TREQ) == 0) && (x == 0x00)) { /* != 0xFF */ /* invert state bits, toggle ODD/EVEN */ via[B] ^= ST_MASK; /* adjust packet length */ reply_len--; reply_ptr--; macii_state = read_done; } else { /* not caught: ST_CMD */ /* required for re-entry 'reading'! */ if ((status & ST_MASK) == ST_IDLE) { /* (in)sanity check - set even */ via[B] = (via[B] & ~ST_MASK) | ST_EVEN; } else { /* invert state bits */ via[B] ^= ST_MASK; } } break; case read_done: x = via[SR]; if (reading_reply) { req = current_req; req->reply_len = reply_ptr - req->reply; req->complete = 1; current_req = req->next; if (req->done) (*req->done)(req); } else { adb_input(reply_buf, reply_ptr - reply_buf, regs, 0); } /* * remember this device ID; it's the latest we got a * reply from! */ last_reply = command_byte; last_active = (command_byte & 0xF0) >> 4; /* SRQ seen before, initiate poll now */ if (need_poll) { macii_state = idle; macii_queue_poll(); need_poll = 0; break; } /* set ADB state to idle */ via[B] = (via[B] & ~ST_MASK) | ST_IDLE; /* /IRQ seen, so the ADB controller has data for us */ if ((via[B] & TREQ) != 0) { macii_state = reading; reply_buf[0] = command_byte; reply_ptr = reply_buf + 1; reply_len = 1; prefix_len = 1; reading_reply = 0; } else { /* no IRQ, send next packet or wait */ macii_state = idle; if (current_req) macii_start(); else macii_retransmit(last_active); } break; default: break; } /* reset mutex and interrupts */ driver_running = 0; local_irq_restore(flags); return IRQ_HANDLED; }