diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/macintosh/via-macii.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/macintosh/via-macii.c')
-rw-r--r-- | drivers/macintosh/via-macii.c | 653 |
1 files changed, 653 insertions, 0 deletions
diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c new file mode 100644 index 00000000000..e9a159ad302 --- /dev/null +++ b/drivers/macintosh/via-macii.c @@ -0,0 +1,653 @@ +/* + * 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; +} |