/* write n bytes to tts port */
static char dtlk_write_bytes(const char *buf, int n)
{
char val = 0;
/* printk("dtlk_write_bytes(\"%-*s\", %d)\n", n, buf, n); */
TRACE_TEXT("(dtlk_write_bytes");
while (n-- > 0)
val = dtlk_write_tts(*buf++);
TRACE_RET;
return val;
}
static void __exit dtlk_cleanup (void)
{
dtlk_write_bytes("goodbye", 8);
msleep_interruptible(500); /* nap 0.50 sec but
could be awakened
earlier by
signals... */
dtlk_write_tts(DTLK_CLEAR);
unregister_chrdev(dtlk_major, "dtlk");
release_region(dtlk_port_lpc, DTLK_IO_EXTENT);
}
static void __exit dtlk_cleanup (void)
{
dtlk_write_bytes("goodbye", 8);
current->state = TASK_INTERRUPTIBLE;
schedule_timeout(5 * HZ / 10); /* nap 0.50 sec but
could be awakened
earlier by
signals... */
dtlk_write_tts(DTLK_CLEAR);
devfs_unregister_chrdev(dtlk_major, "dtlk");
devfs_unregister(devfs_handle);
release_region(dtlk_port_lpc, DTLK_IO_EXTENT);
}
static ssize_t dtlk_write(struct file *file, const char __user *buf,
size_t count, loff_t * ppos)
{
int i = 0, retries = 0, ch;
TRACE_TEXT("(dtlk_write");
#ifdef TRACING
printk(" \"");
{
int i, ch;
for (i = 0; i < count; i++) {
if (get_user(ch, buf + i))
return -EFAULT;
if (' ' <= ch && ch <= '~')
printk("%c", ch);
else
printk("\\%03o", ch);
}
printk("\"");
}
#endif
if (iminor(file->f_path.dentry->d_inode) != DTLK_MINOR)
return -EINVAL;
while (1) {
while (i < count && !get_user(ch, buf) &&
(ch == DTLK_CLEAR || dtlk_writeable())) {
dtlk_write_tts(ch);
buf++;
i++;
if (i % 5 == 0)
/* We yield our time until scheduled
again. This reduces the transfer
rate to 500 bytes/sec, but that's
still enough to keep up with the
speech synthesizer. */
msleep_interruptible(1);
else {
/* the RDY bit goes zero 2-3 usec
after writing, and goes 1 again
180-190 usec later. Here, we wait
up to 250 usec for the RDY bit to
go nonzero. */
for (retries = 0;
retries < loops_per_jiffy / (4000/HZ);
retries++)
if (inb_p(dtlk_port_tts) &
TTS_WRITABLE)
break;
}
retries = 0;
}
if (i == count)
return i;
if (file->f_flags & O_NONBLOCK)
break;
msleep_interruptible(1);
if (++retries > 10 * HZ) { /* wait no more than 10 sec
from last write */
printk("dtlk: write timeout. "
"inb_p(dtlk_port_tts) = 0x%02x\n",
inb_p(dtlk_port_tts));
TRACE_RET;
return -EBUSY;
}
}
TRACE_RET;
return -EAGAIN;
}
