/* 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));
save_flags(flags);
cli();
if (current_req != NULL) {
last_req->next = &rt;
last_req = &rt;
} else {
current_req = &rt;
last_req = &rt;
}
if (macii_state == idle) macii_start();
restore_flags(flags);
in_retransmit--;
}
/* 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));
save_flags(flags);
cli();
req.next = current_req;
current_req = &req;
restore_flags(flags);
macii_start();
in_poll--;
}
/* XXX: move that to cuda ? */
int adb_poll(ADBBusState *s, uint8_t *obuf, uint16_t poll_mask)
{
ADBDevice *d;
int olen, i;
uint8_t buf[1];
olen = 0;
for(i = 0; i < s->nb_devices; i++) {
if (s->poll_index >= s->nb_devices)
s->poll_index = 0;
d = s->devices[s->poll_index];
if ((1 << d->devaddr) & poll_mask) {
buf[0] = ADB_READREG | (d->devaddr << 4);
olen = adb_request(s, obuf + 1, buf, 1);
/* if there is data, we poll again the same device */
if (olen > 0) {
obuf[0] = buf[0];
olen++;
break;
}
}
s->poll_index++;
}
return olen;
}
/* 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;
}
/* Try to change handler to new_id. Will return 1 if successful. */
static int try_handler_change(int address, int new_id)
{
struct adb_request req;
if (adb_handler[address].handler_id == new_id)
return 1;
adb_request(&req, NULL, ADBREQ_SYNC, 3,
ADB_WRITEREG(address, 3), address | 0x20, new_id);
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
ADB_READREG(address, 3));
if (req.reply_len < 2)
return 0;
if (req.reply[2] != new_id)
return 0;
adb_handler[address].handler_id = req.reply[2];
return 1;
}
static int adb_scan_bus(void)
{
int i, highFree=0, noMovement;
int devmask = 0;
struct adb_request req;
/* assumes adb_handler[] is all zeroes at this point */
for (i = 1; i < 16; i++) {
/* see if there is anything at address i */
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
(i << 4) | 0xf);
if (req.reply_len > 1)
/* one or more devices at this address */
adb_handler[i].original_address = i;
else if (i > highFree)
highFree = i;
}
/* Note we reset noMovement to 0 each time we move a device */
for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
for (i = 1; i < 16; i++) {
if (adb_handler[i].original_address == 0)
continue;
/*
* Send a "talk register 3" command to address i
* to provoke a collision if there is more than
* one device at this address.
*/
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
(i << 4) | 0xf);
/*
* Move the device(s) which didn't detect a
* collision to address `highFree'. Hopefully
* this only moves one device.
*/
adb_request(&req, NULL, ADBREQ_SYNC, 3,
(i<< 4) | 0xb, (highFree | 0x60), 0xfe);
/*
* See if anybody actually moved. This is suggested
* by HW TechNote 01:
*
* http://developer.apple.com/technotes/hw/hw_01.html
*/
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
(highFree << 4) | 0xf);
if (req.reply_len <= 1) continue;
/*
* Test whether there are any device(s) left
* at address i.
*/
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
(i << 4) | 0xf);
if (req.reply_len > 1) {
/*
* There are still one or more devices
* left at address i. Register the one(s)
* we moved to `highFree', and find a new
* value for highFree.
*/
adb_handler[highFree].original_address =
adb_handler[i].original_address;
while (highFree > 0 &&
adb_handler[highFree].original_address)
highFree--;
if (highFree <= 0)
break;
noMovement = 0;
}
else {
/*
* No devices left at address i; move the
* one(s) we moved to `highFree' back to i.
*/
adb_request(&req, NULL, ADBREQ_SYNC, 3,
(highFree << 4) | 0xb,
(i | 0x60), 0xfe);
}
}
}
/* Now fill in the handler_id field of the adb_handler entries. */
printk(KERN_DEBUG "adb devices:");
for (i = 1; i < 16; i++) {
if (adb_handler[i].original_address == 0)
continue;
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
(i << 4) | 0xf);
adb_handler[i].handler_id = req.reply[2];
printk(" [%d]: %d %x", i, adb_handler[i].original_address,
adb_handler[i].handler_id);
devmask |= 1 << i;
}
printk("\n");
return devmask;
}