diff options
Diffstat (limited to 'drivers/macintosh/via-macii.c')
| -rw-r--r-- | drivers/macintosh/via-macii.c | 582 |
1 files changed, 241 insertions, 341 deletions
diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c index 1b3bad62a1b..01b8eca7ccd 100644 --- a/drivers/macintosh/via-macii.c +++ b/drivers/macintosh/via-macii.c @@ -12,6 +12,15 @@ * 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. + * 2006-12-31 Finn Thain <fthain@telegraphics.com.au> - Another overhaul. + * + * Suggested reading: + * Inside Macintosh, ch. 5 ADB Manager + * Guide to the Macinstosh Family Hardware, ch. 8 Apple Desktop Bus + * Rockwell R6522 VIA datasheet + * + * Apple's "ADB Analyzer" bus sniffer is invaluable: + * ftp://ftp.apple.com/developer/Tool_Chest/Devices_-_Hardware/Apple_Desktop_Bus/ */ #include <stdarg.h> @@ -26,7 +35,6 @@ #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; @@ -51,9 +59,7 @@ static volatile unsigned char *via; #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 CTLR_IRQ 0x08 /* Controller rcv status (input) */ #define ST_MASK 0x30 /* mask for selecting ADB state bits */ /* Bits in ACR */ @@ -65,8 +71,6 @@ static volatile unsigned char *via; #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 */ @@ -77,7 +81,6 @@ static volatile unsigned char *via; static int macii_init_via(void); static void macii_start(void); static irqreturn_t macii_interrupt(int irq, void *arg); -static void macii_retransmit(int); static void macii_queue_poll(void); static int macii_probe(void); @@ -103,29 +106,37 @@ static enum macii_state { sending, reading, read_done, - awaiting_reply } macii_state; -static int need_poll; -static int command_byte; -static int last_reply; -static int last_active; - -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; - -/* debug level 10 required for ADB logging (should be && debug_adb, ideally) */ +static struct adb_request *current_req; /* first request struct in the queue */ +static struct adb_request *last_req; /* last request struct in the queue */ +static unsigned char reply_buf[16]; /* storage for autopolled replies */ +static unsigned char *reply_ptr; /* next byte in req->data or reply_buf */ +static int reading_reply; /* store reply in reply_buf else req->reply */ +static int data_index; /* index of the next byte to send from req->data */ +static int reply_len; /* number of bytes received in reply_buf or req->reply */ +static int status; /* VIA's ADB status bits captured upon interrupt */ +static int last_status; /* status bits as at previous interrupt */ +static int srq_asserted; /* have to poll for the device that asserted it */ +static int command_byte; /* the most recent command byte transmitted */ +static int autopoll_devs; /* bits set are device addresses to be polled */ + +/* Sanity check for request queue. Doesn't check for cycles. */ +static int request_is_queued(struct adb_request *req) { + struct adb_request *cur; + unsigned long flags; + local_irq_save(flags); + cur = current_req; + while (cur) { + if (cur == req) { + local_irq_restore(flags); + return 1; + } + cur = cur->next; + } + local_irq_restore(flags); + return 0; +} /* Check for MacII style ADB */ static int macii_probe(void) @@ -147,15 +158,16 @@ int macii_init(void) local_irq_save(flags); err = macii_init_via(); - if (err) return err; + if (err) goto out; err = request_irq(IRQ_MAC_ADB, macii_interrupt, IRQ_FLG_LOCK, "ADB", macii_interrupt); - if (err) return err; + if (err) goto out; macii_state = idle; +out: local_irq_restore(flags); - return 0; + return err; } /* initialize the hardware */ @@ -163,12 +175,12 @@ 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; + /* We want CTLR_IRQ as input and ST_EVEN | ST_ODD as output lines. */ + via[DIRB] = (via[DIRB] | ST_EVEN | ST_ODD) & ~CTLR_IRQ; /* Set up state: idle */ via[B] |= ST_IDLE; - last_status = via[B] & (ST_MASK|TREQ); + last_status = via[B] & (ST_MASK|CTLR_IRQ); /* Shift register on input */ via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT; @@ -179,81 +191,72 @@ static int macii_init_via(void) return 0; } -/* Send an ADB poll (Talk Register 0 command, tagged on the front of the request queue) */ +/* Send an ADB poll (Talk Register 0 command prepended to the request queue) */ static void macii_queue_poll(void) { - static int device = 0; - static int in_poll=0; + /* No point polling the active device as it will never assert SRQ, so + * poll the next device in the autopoll list. This could leave us + * stuck in a polling loop if an unprobed device is asserting SRQ. + * In theory, that could only happen if a device was plugged in after + * probing started. Unplugging it again will break the cycle. + * (Simply polling the next higher device often ends up polling almost + * every device (after wrapping around), which takes too long.) + */ + int device_mask; + int next_device; 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--; -} + if (!autopoll_devs) return; -/* 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"); + device_mask = (1 << (((command_byte & 0xF0) >> 4) + 1)) - 1; + if (autopoll_devs & ~device_mask) + next_device = ffs(autopoll_devs & ~device_mask) - 1; + else + next_device = ffs(autopoll_devs) - 1; - in_retransmit++; + BUG_ON(request_is_queued(&req)); - adb_request(&rt, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1, - ADB_READREG(device, 0)); + adb_request(&req, NULL, ADBREQ_NOSEND, 1, + ADB_READREG(next_device, 0)); - local_irq_save(flags); + req.sent = 0; + req.complete = 0; + req.reply_len = 0; + req.next = current_req; if (current_req != NULL) { - last_req->next = &rt; - last_req = &rt; + current_req = &req; } else { - current_req = &rt; - last_req = &rt; + current_req = &req; + last_req = &req; } - - 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; + int err; + unsigned long flags; - i = macii_write(req); - if (i) return i; + BUG_ON(request_is_queued(req)); - if (sync) { - while (!req->complete) macii_poll(); + local_irq_save(flags); + err = macii_write(req); + local_irq_restore(flags); + + if (!err && sync) { + while (!req->complete) { + macii_poll(); + } + BUG_ON(request_is_queued(req)); } - return 0; + + return err; } -/* Send an ADB request */ +/* Send an ADB request (append to request queue) */ 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; @@ -264,8 +267,6 @@ static int macii_write(struct adb_request *req) req->complete = 0; req->reply_len = 0; - local_irq_save(flags); - if (current_req != NULL) { last_req->next = req; last_req = req; @@ -274,28 +275,52 @@ static int macii_write(struct adb_request *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; + static struct adb_request req; + unsigned long flags; + int err = 0; + + /* bit 1 == device 1, and so on. */ + autopoll_devs = devs & 0xFFFE; + + if (!autopoll_devs) return 0; + + local_irq_save(flags); + + if (current_req == NULL) { + /* Send a Talk Reg 0. The controller will repeatedly transmit + * this as long as it is idle. + */ + adb_request(&req, NULL, ADBREQ_NOSEND, 1, + ADB_READREG(ffs(autopoll_devs) - 1, 0)); + err = macii_write(&req); + } + + local_irq_restore(flags); + return err; +} + +static inline int need_autopoll(void) { + /* Was the last command Talk Reg 0 + * and is the target on the autopoll list? + */ + if ((command_byte & 0x0F) == 0x0C && + ((1 << ((command_byte & 0xF0) >> 4)) & autopoll_devs)) + return 0; + return 1; } /* 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, NULL); - local_irq_restore(flags); + disable_irq(IRQ_MAC_ADB); + macii_interrupt(0, NULL); + enable_irq(IRQ_MAC_ADB); } /* Reset the bus */ @@ -303,73 +328,34 @@ static int macii_reset_bus(void) { static struct adb_request req; + if (request_is_queued(&req)) + return 0; + /* Command = 0, Address = ignored */ adb_request(&req, NULL, 0, 1, ADB_BUSRESET); + /* Don't want any more requests during the Global Reset low time. */ + udelay(3000); + 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) + BUG_ON(req == NULL); + + BUG_ON(macii_state != idle); + + /* Now send it. Be careful though, that first byte of the request + * is actually ADB_PACKET; the real data begins at index 1! + * And req->nbytes is the number of bytes of real data plus one. */ - 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 */ @@ -381,115 +367,97 @@ static void macii_start(void) 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 notorious ADB interrupt handler - does all of the protocol handling. + * Relies on the ADB controller sending and receiving data, thereby + * generating shift register interrupts (SR_INT) for us. This means there has + * to be activity on the ADB bus. The chip will poll to achieve this. * * 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). + * The syntax of the ADB status lines is 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 signalled by asserting /IRQ on the + * interrupt line (/IRQ means the CTLR_IRQ bit in port B; not to be confused + * with the VIA shift register interrupt. /IRQ never actually interrupts the + * processor, it's just an ordinary input.) */ static irqreturn_t macii_interrupt(int irq, void *arg) { - int x, adbdir; - unsigned long flags; + int x; + static int entered; 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; + if (!arg) { + /* Clear the SR IRQ flag when polling. */ + if (via[IFR] & SR_INT) + via[IFR] = SR_INT; + else + return IRQ_NONE; } - driver_running = 1; - - status = via[B] & (ST_MASK|TREQ); - adbdir = via[ACR] & SR_OUT; + BUG_ON(entered++); + + last_status = status; + status = via[B] & (ST_MASK|CTLR_IRQ); switch (macii_state) { case idle: + if (reading_reply) { + reply_ptr = current_req->reply; + } else { + BUG_ON(current_req != NULL); + reply_ptr = reply_buf; + } + 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; + if ((status & CTLR_IRQ) && (x == 0xFF)) { + /* Bus timeout without SRQ sequence: + * data is "FF" while CTLR_IRQ is "H" + */ + reply_len = 0; + srq_asserted = 0; + macii_state = read_done; + } else { + macii_state = reading; + *reply_ptr = x; + reply_len = 1; + } - 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; + macii_state = idle; if (req->reply_expected) { - macii_state = awaiting_reply; + reading_reply = 1; } else { req->complete = 1; current_req = req->next; if (req->done) (*req->done)(req); - macii_state = idle; - if (current_req || retry_req) + + if (current_req) macii_start(); else - macii_retransmit((command_byte & 0xF0) >> 4); + if (need_autopoll()) + macii_autopoll(autopoll_devs); + } + + if (macii_state == idle) { + /* 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; } } else { via[SR] = req->data[data_index++]; @@ -505,147 +473,79 @@ static irqreturn_t macii_interrupt(int irq, void *arg) break; case reading: + x = via[SR]; + BUG_ON((status & ST_MASK) == ST_CMD || + (status & ST_MASK) == ST_IDLE); + + /* Bus timeout with SRQ sequence: + * data is "XX FF" while CTLR_IRQ is "L L" + * End of packet without SRQ sequence: + * data is "XX...YY 00" while CTLR_IRQ is "L...H L" + * End of packet SRQ sequence: + * data is "XX...YY 00" while CTLR_IRQ is "L...L L" + * (where XX is the first response byte and + * YY is the last byte of valid response data.) + */ - /* 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; + srq_asserted = 0; + if (!(status & CTLR_IRQ)) { + if (x == 0xFF) { + if (!(last_status & CTLR_IRQ)) { + macii_state = read_done; + reply_len = 0; + srq_asserted = 1; + } + } else if (x == 0x00) { + macii_state = read_done; + if (!(last_status & CTLR_IRQ)) + srq_asserted = 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; + } + + if (macii_state == reading) { + BUG_ON(reply_len > 15); reply_ptr++; + *reply_ptr = x; 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; - } - } + /* invert state bits, toggle ODD/EVEN */ + via[B] ^= ST_MASK; break; case read_done: x = via[SR]; + if (reading_reply) { + reading_reply = 0; req = current_req; - req->reply_len = reply_ptr - req->reply; + req->reply_len = reply_len; req->complete = 1; current_req = req->next; if (req->done) (*req->done)(req); - } else { - adb_input(reply_buf, reply_ptr - reply_buf, 0); - } + } else if (reply_len && autopoll_devs) + adb_input(reply_buf, reply_len, 0); - /* - * remember this device ID; it's the latest we got a - * reply from! - */ - last_reply = command_byte; - last_active = (command_byte & 0xF0) >> 4; + macii_state = idle; /* SRQ seen before, initiate poll now */ - if (need_poll) { - macii_state = idle; + if (srq_asserted) 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); - } + if (current_req) + macii_start(); + else + if (need_autopoll()) + macii_autopoll(autopoll_devs); + + if (macii_state == idle) + via[B] = (via[B] & ~ST_MASK) | ST_IDLE; break; default: break; } - /* reset mutex and interrupts */ - driver_running = 0; - local_irq_restore(flags); + + entered--; return IRQ_HANDLED; } |