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/*
* Device driver for the IIsi-style ADB on some Mac LC and II-class machines
*
* Based on via-cuda.c and via-macii.c, as well as the original
* adb-bus.c, which in turn is somewhat influenced by (but uses no
* code from) the NetBSD HWDIRECT ADB code. Original IIsi driver work
* was done by Robert Thompson and integrated into the old style
* driver by Michael Schmitz.
*
* Original sources (c) Alan Cox, Paul Mackerras, and others.
*
* Rewritten for Unified ADB by David Huggins-Daines <dhd@debian.org> */
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/delay.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>
static volatile unsigned char *via;
/* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
#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 SR (10*RS) /* Shift register */
#define ACR (11*RS) /* Auxiliary control register */
#define IFR (13*RS) /* Interrupt flag register */
#define IER (14*RS) /* Interrupt enable register */
/* 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 */
#define ADB_DELAY 150
static struct adb_request* current_req = NULL;
static struct adb_request* last_req = NULL;
static unsigned char maciisi_rbuf[16];
static unsigned char *reply_ptr = NULL;
static int data_index;
static int reading_reply;
static int reply_len;
static enum maciisi_state {
idle,
sending,
reading,
} maciisi_state;
static int maciisi_probe(void);
static int maciisi_init(void);
static int maciisi_send_request(struct adb_request* req, int sync);
static int maciisi_write(struct adb_request* req);
static void maciisi_interrupt(int irq, void* arg, struct pt_regs* regs);
static void maciisi_input(unsigned char *buf, int nb, struct pt_regs *regs);
static int maciisi_init_via(void);
static void maciisi_poll(void);
static void maciisi_start(void);
struct adb_driver via_maciisi_driver = {
"Mac IIsi",
maciisi_probe,
maciisi_init,
maciisi_send_request,
NULL, /* maciisi_adb_autopoll, */
maciisi_poll,
NULL /* maciisi_reset_adb_bus */
};
static int
maciisi_probe(void)
{
if (macintosh_config->adb_type != MAC_ADB_IISI)
return -ENODEV;
via = via1;
return 0;
}
static int
maciisi_init(void)
{
int err;
if (via == NULL)
return -ENODEV;
if ((err = maciisi_init_via())) {
printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
via = NULL;
return err;
}
if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK,
"ADB", maciisi_interrupt)) {
printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
return -EAGAIN;
}
printk("adb: Mac IIsi driver v0.1 for Unified ADB.\n");
return 0;
}
static void
maciisi_stfu(void)
{
int status = via[B] & (TIP|TREQ);
if (status & TREQ) {
printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
return;
}
/* start transfer */
via[B] |= TIP;
while (!(status & TREQ)) {
int poll_timeout = ADB_DELAY * 5;
/* Poll for SR interrupt */
while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
status = via[B] & (TIP|TREQ);
via[SR]; /* Clear shift register */
printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d\n",
status, poll_timeout);
/* ACK on-off */
via[B] |= TACK;
udelay(ADB_DELAY);
via[B] &= ~TACK;
}
/* end frame */
via[B] &= ~TIP;
}
/* All specifically VIA-related initialization goes here */
static int
maciisi_init_via(void)
{
/* Set the lines up. We want TREQ as input TACK|TIP as output */
via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
/* Shift register on input */
via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT;
printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
/* Set initial state: idle */
via[B] &= ~(TACK|TIP);
/* Wipe any pending data and int */
via[SR];
if (!(via[B] & TREQ))
maciisi_stfu();
via[IER] = IER_SET | SR_INT;
maciisi_state = idle;
return 0;
}
/* Send a request, possibly waiting for a reply */
static int
maciisi_send_request(struct adb_request* req, int sync)
{
int i;
static int dump_packet = 1;
if (via == NULL) {
req->complete = 1;
return -ENXIO;
}
if (dump_packet) {
printk(KERN_DEBUG "maciisi_send_request:");
for (i = 0; i < req->nbytes; i++) {
printk(" %.2x", req->data[i]);
}
printk("\n");
}
req->reply_expected = 1;
i = maciisi_write(req);
if (i)
return i;
if (sync) {
while (!req->complete) {
maciisi_poll();
}
}
return 0;
}
/* Enqueue a request, and run the queue if possible */
static int
maciisi_write(struct adb_request* req)
{
unsigned long flags;
printk(KERN_DEBUG "maciisi_write called, state=%d ifr=%x\n", maciisi_state, via[IFR]);
/* We will accept CUDA packets - the VIA sends them to us, so
it figures that we should be able to send them to it */
if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
req->complete = 1;
return -EINVAL;
}
req->next = 0;
req->sent = 0;
req->complete = 0;
req->reply_len = 0;
save_flags(flags); cli();
if (current_req) {
last_req->next = req;
last_req = req;
} else {
current_req = req;
last_req = req;
}
if (maciisi_state == idle)
maciisi_start();
else
printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
restore_flags(flags);
return 0;
}
static void
maciisi_start(void)
{
struct adb_request* req;
int status;
printk(KERN_DEBUG "maciisi_start called, state=%d, ifr=%x\n", maciisi_state, via[IFR]);
if (maciisi_state != idle) {
/* shouldn't happen */
printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
return;
}
req = current_req;
if (req == NULL)
return;
status = via[B] & (TIP|TREQ);
if (!(status & TREQ)) {
/* Bus is busy, set up for reading */
printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
return;
}
/* Okay, send */
printk(KERN_DEBUG "maciisi_start: sending\n");
/* Set state to active */
via[B] |= TIP;
/* ACK off */
via[B] &= ~TACK;
/* Shift out and send */
via[ACR] |= SR_OUT;
via[SR] = req->data[0];
data_index = 1;
/* ACK on */
via[B] |= TACK;
maciisi_state = sending;
}
void
maciisi_poll(void)
{
unsigned long flags;
save_flags(flags);
cli();
if (via[IFR] & SR_INT) {
maciisi_interrupt(0, 0, 0);
}
restore_flags(flags);
}
/* Shift register interrupt - this is *supposed* to mean that the
register is either full or empty. In practice, I have no idea what
it means :( */
static void
maciisi_interrupt(int irq, void* arg, struct pt_regs* regs)
{
int status;
struct adb_request *req;
static int dump_reply = 1;
if (!(via[IFR] & SR_INT)) {
/* Shouldn't happen, we hope */
printk(KERN_DEBUG "maciisi_interrupt: called without interrupt flag set\n");
return;
}
status = via[B] & (TIP|TREQ);
printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
switch_start:
switch (maciisi_state) {
case idle:
printk(KERN_DEBUG "maciisi_interrupt: state=idle, status %x\n", status);
if (status & TIP)
printk(KERN_DEBUG "maciisi_interrupt: state is idle but TIP asserted!\n");
udelay(ADB_DELAY);
/* Shift in */
via[ACR] &= ~SR_OUT;
/* Signal start of frame */
via[B] |= TIP;
/* Clear the interrupt (throw this value on the floor, it's useless) */
via[SR];
/* ACK adb chip, high-low */
via[B] |= TACK;
udelay(ADB_DELAY);
via[B] &= ~TACK;
reply_len = 0;
maciisi_state = reading;
if (reading_reply) {
reply_ptr = current_req->reply;
} else {
printk(KERN_DEBUG "maciisi_interrupt: received unsolicited packet\n");
reply_ptr = maciisi_rbuf;
}
break;
case sending:
printk(KERN_DEBUG "maciisi_interrupt: state=sending, status=%x\n", status);
/* Clear interrupt */
via[SR];
/* Set ACK off */
via[B] &= ~TACK;
req = current_req;
if (!(status & TREQ)) {
/* collision */
printk(KERN_DEBUG "maciisi_interrupt: send collision\n");
/* Set idle and input */
via[B] &= ~TIP;
via[ACR] &= ~SR_OUT;
/* Must re-send */
reading_reply = 0;
reply_len = 0;
maciisi_state = idle;
/* process this now, because the IFR has been cleared */
goto switch_start;
}
if (data_index >= req->nbytes) {
/* Sent the whole packet, put the bus back in idle state */
/* Shift in, we are about to read a reply (hopefully) */
via[ACR] &= ~SR_OUT;
/* End of frame */
via[B] &= ~TIP;
req->sent = 1;
maciisi_state = idle;
if (req->reply_expected) {
/* Note: only set this once we've
successfully sent the packet */
reading_reply = 1;
} else {
current_req = req->next;
if (req->done)
(*req->done)(req);
}
} else {
/* Sending more stuff */
/* Shift out */
via[ACR] |= SR_OUT;
/* Delay */
udelay(ADB_DELAY);
/* Write */
via[SR] = req->data[data_index++];
/* Signal 'byte ready' */
via[B] |= TACK;
}
break;
case reading:
printk(KERN_DEBUG "maciisi_interrupt: state=reading, status=%x\n", status);
/* Shift in */
via[ACR] &= ~SR_OUT;
if (reply_len++ > 16) {
printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
via[B] |= TACK;
udelay(ADB_DELAY);
via[B] &= ~(TACK|TIP);
maciisi_state = idle;
maciisi_start();
break;
}
*reply_ptr++ = via[SR];
status = via[B] & (TIP|TREQ);
/* ACK on/off */
via[B] |= TACK;
udelay(ADB_DELAY);
via[B] &= ~TACK;
if (!(status & TREQ))
break; /* more stuff to deal with */
/* end of frame */
via[B] &= ~TIP;
/* end of packet, deal with it */
if (reading_reply) {
req = current_req;
req->reply_len = reply_ptr - req->reply;
if (req->data[0] == ADB_PACKET) {
/* Have to adjust the reply from ADB commands */
if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
/* the 0x2 bit indicates no response */
req->reply_len = 0;
} else {
/* leave just the command and result bytes in the reply */
req->reply_len -= 2;
memmove(req->reply, req->reply + 2, req->reply_len);
}
}
if (dump_reply) {
int i;
printk(KERN_DEBUG "maciisi_interrupt: reply is ");
for (i = 0; i < req->reply_len; ++i)
printk(" %.2x", req->reply[i]);
printk("\n");
}
req->complete = 1;
current_req = req->next;
if (req->done)
(*req->done)(req);
/* Obviously, we got it */
reading_reply = 0;
} else {
maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf, regs);
}
maciisi_state = idle;
status = via[B] & (TIP|TREQ);
if (!(status & TREQ)) {
/* Timeout?! */
printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
status, via[IFR]);
maciisi_stfu();
}
/* Do any queued requests now if possible */
maciisi_start();
break;
default:
printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
}
}
static void
maciisi_input(unsigned char *buf, int nb, struct pt_regs *regs)
{
int i;
switch (buf[0]) {
case ADB_PACKET:
adb_input(buf+2, nb-2, regs, buf[1] & 0x40);
break;
default:
printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
for (i = 0; i < nb; ++i)
printk(" %.2x", buf[i]);
printk("\n");
}
}
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