664 lines
16 KiB
C
664 lines
16 KiB
C
/* -*- linux-c -*-
|
|
* dtlk.c - DoubleTalk PC driver for Linux
|
|
*
|
|
* Original author: Chris Pallotta <chris@allmedia.com>
|
|
* Current maintainer: Jim Van Zandt <jrv@vanzandt.mv.com>
|
|
*
|
|
* 2000-03-18 Jim Van Zandt: Fix polling.
|
|
* Eliminate dtlk_timer_active flag and separate dtlk_stop_timer
|
|
* function. Don't restart timer in dtlk_timer_tick. Restart timer
|
|
* in dtlk_poll after every poll. dtlk_poll returns mask (duh).
|
|
* Eliminate unused function dtlk_write_byte. Misc. code cleanups.
|
|
*/
|
|
|
|
/* This driver is for the DoubleTalk PC, a speech synthesizer
|
|
manufactured by RC Systems (http://www.rcsys.com/). It was written
|
|
based on documentation in their User's Manual file and Developer's
|
|
Tools disk.
|
|
|
|
The DoubleTalk PC contains four voice synthesizers: text-to-speech
|
|
(TTS), linear predictive coding (LPC), PCM/ADPCM, and CVSD. It
|
|
also has a tone generator. Output data for LPC are written to the
|
|
LPC port, and output data for the other modes are written to the
|
|
TTS port.
|
|
|
|
Two kinds of data can be read from the DoubleTalk: status
|
|
information (in response to the "\001?" interrogation command) is
|
|
read from the TTS port, and index markers (which mark the progress
|
|
of the speech) are read from the LPC port. Not all models of the
|
|
DoubleTalk PC implement index markers. Both the TTS and LPC ports
|
|
can also display status flags.
|
|
|
|
The DoubleTalk PC generates no interrupts.
|
|
|
|
These characteristics are mapped into the Unix stream I/O model as
|
|
follows:
|
|
|
|
"write" sends bytes to the TTS port. It is the responsibility of
|
|
the user program to switch modes among TTS, PCM/ADPCM, and CVSD.
|
|
This driver was written for use with the text-to-speech
|
|
synthesizer. If LPC output is needed some day, other minor device
|
|
numbers can be used to select among output modes.
|
|
|
|
"read" gets index markers from the LPC port. If the device does
|
|
not implement index markers, the read will fail with error EINVAL.
|
|
|
|
Status information is available using the DTLK_INTERROGATE ioctl.
|
|
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
|
|
#define KERNEL
|
|
#include <linux/types.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/errno.h> /* for -EBUSY */
|
|
#include <linux/ioport.h> /* for request_region */
|
|
#include <linux/delay.h> /* for loops_per_jiffy */
|
|
#include <linux/sched.h>
|
|
#include <linux/mutex.h>
|
|
#include <asm/io.h> /* for inb_p, outb_p, inb, outb, etc. */
|
|
#include <linux/uaccess.h> /* for get_user, etc. */
|
|
#include <linux/wait.h> /* for wait_queue */
|
|
#include <linux/init.h> /* for __init, module_{init,exit} */
|
|
#include <linux/poll.h> /* for POLLIN, etc. */
|
|
#include <linux/dtlk.h> /* local header file for DoubleTalk values */
|
|
|
|
#ifdef TRACING
|
|
#define TRACE_TEXT(str) printk(str);
|
|
#define TRACE_RET printk(")")
|
|
#else /* !TRACING */
|
|
#define TRACE_TEXT(str) ((void) 0)
|
|
#define TRACE_RET ((void) 0)
|
|
#endif /* TRACING */
|
|
|
|
static DEFINE_MUTEX(dtlk_mutex);
|
|
static void dtlk_timer_tick(struct timer_list *unused);
|
|
|
|
static int dtlk_major;
|
|
static int dtlk_port_lpc;
|
|
static int dtlk_port_tts;
|
|
static int dtlk_busy;
|
|
static int dtlk_has_indexing;
|
|
static unsigned int dtlk_portlist[] =
|
|
{0x25e, 0x29e, 0x2de, 0x31e, 0x35e, 0x39e, 0};
|
|
static wait_queue_head_t dtlk_process_list;
|
|
static DEFINE_TIMER(dtlk_timer, dtlk_timer_tick);
|
|
|
|
/* prototypes for file_operations struct */
|
|
static ssize_t dtlk_read(struct file *, char __user *,
|
|
size_t nbytes, loff_t * ppos);
|
|
static ssize_t dtlk_write(struct file *, const char __user *,
|
|
size_t nbytes, loff_t * ppos);
|
|
static unsigned int dtlk_poll(struct file *, poll_table *);
|
|
static int dtlk_open(struct inode *, struct file *);
|
|
static int dtlk_release(struct inode *, struct file *);
|
|
static long dtlk_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg);
|
|
|
|
static const struct file_operations dtlk_fops =
|
|
{
|
|
.owner = THIS_MODULE,
|
|
.read = dtlk_read,
|
|
.write = dtlk_write,
|
|
.poll = dtlk_poll,
|
|
.unlocked_ioctl = dtlk_ioctl,
|
|
.open = dtlk_open,
|
|
.release = dtlk_release,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
/* local prototypes */
|
|
static int dtlk_dev_probe(void);
|
|
static struct dtlk_settings *dtlk_interrogate(void);
|
|
static int dtlk_readable(void);
|
|
static char dtlk_read_lpc(void);
|
|
static char dtlk_read_tts(void);
|
|
static int dtlk_writeable(void);
|
|
static char dtlk_write_bytes(const char *buf, int n);
|
|
static char dtlk_write_tts(char);
|
|
/*
|
|
static void dtlk_handle_error(char, char, unsigned int);
|
|
*/
|
|
|
|
static ssize_t dtlk_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t * ppos)
|
|
{
|
|
unsigned int minor = iminor(file_inode(file));
|
|
char ch;
|
|
int i = 0, retries;
|
|
|
|
TRACE_TEXT("(dtlk_read");
|
|
/* printk("DoubleTalk PC - dtlk_read()\n"); */
|
|
|
|
if (minor != DTLK_MINOR || !dtlk_has_indexing)
|
|
return -EINVAL;
|
|
|
|
for (retries = 0; retries < loops_per_jiffy; retries++) {
|
|
while (i < count && dtlk_readable()) {
|
|
ch = dtlk_read_lpc();
|
|
/* printk("dtlk_read() reads 0x%02x\n", ch); */
|
|
if (put_user(ch, buf++))
|
|
return -EFAULT;
|
|
i++;
|
|
}
|
|
if (i)
|
|
return i;
|
|
if (file->f_flags & O_NONBLOCK)
|
|
break;
|
|
msleep_interruptible(100);
|
|
}
|
|
if (retries == loops_per_jiffy)
|
|
printk(KERN_ERR "dtlk_read times out\n");
|
|
TRACE_RET;
|
|
return -EAGAIN;
|
|
}
|
|
|
|
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_inode(file)) != 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;
|
|
}
|
|
|
|
static unsigned int dtlk_poll(struct file *file, poll_table * wait)
|
|
{
|
|
int mask = 0;
|
|
unsigned long expires;
|
|
|
|
TRACE_TEXT(" dtlk_poll");
|
|
/*
|
|
static long int j;
|
|
printk(".");
|
|
printk("<%ld>", jiffies-j);
|
|
j=jiffies;
|
|
*/
|
|
poll_wait(file, &dtlk_process_list, wait);
|
|
|
|
if (dtlk_has_indexing && dtlk_readable()) {
|
|
del_timer(&dtlk_timer);
|
|
mask = POLLIN | POLLRDNORM;
|
|
}
|
|
if (dtlk_writeable()) {
|
|
del_timer(&dtlk_timer);
|
|
mask |= POLLOUT | POLLWRNORM;
|
|
}
|
|
/* there are no exception conditions */
|
|
|
|
/* There won't be any interrupts, so we set a timer instead. */
|
|
expires = jiffies + 3*HZ / 100;
|
|
mod_timer(&dtlk_timer, expires);
|
|
|
|
return mask;
|
|
}
|
|
|
|
static void dtlk_timer_tick(struct timer_list *unused)
|
|
{
|
|
TRACE_TEXT(" dtlk_timer_tick");
|
|
wake_up_interruptible(&dtlk_process_list);
|
|
}
|
|
|
|
static long dtlk_ioctl(struct file *file,
|
|
unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
char __user *argp = (char __user *)arg;
|
|
struct dtlk_settings *sp;
|
|
char portval;
|
|
TRACE_TEXT(" dtlk_ioctl");
|
|
|
|
switch (cmd) {
|
|
|
|
case DTLK_INTERROGATE:
|
|
mutex_lock(&dtlk_mutex);
|
|
sp = dtlk_interrogate();
|
|
mutex_unlock(&dtlk_mutex);
|
|
if (copy_to_user(argp, sp, sizeof(struct dtlk_settings)))
|
|
return -EINVAL;
|
|
return 0;
|
|
|
|
case DTLK_STATUS:
|
|
portval = inb_p(dtlk_port_tts);
|
|
return put_user(portval, argp);
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Note that nobody ever sets dtlk_busy... */
|
|
static int dtlk_open(struct inode *inode, struct file *file)
|
|
{
|
|
TRACE_TEXT("(dtlk_open");
|
|
|
|
nonseekable_open(inode, file);
|
|
switch (iminor(inode)) {
|
|
case DTLK_MINOR:
|
|
if (dtlk_busy)
|
|
return -EBUSY;
|
|
return nonseekable_open(inode, file);
|
|
|
|
default:
|
|
return -ENXIO;
|
|
}
|
|
}
|
|
|
|
static int dtlk_release(struct inode *inode, struct file *file)
|
|
{
|
|
TRACE_TEXT("(dtlk_release");
|
|
|
|
switch (iminor(inode)) {
|
|
case DTLK_MINOR:
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
TRACE_RET;
|
|
|
|
del_timer_sync(&dtlk_timer);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init dtlk_init(void)
|
|
{
|
|
int err;
|
|
|
|
dtlk_port_lpc = 0;
|
|
dtlk_port_tts = 0;
|
|
dtlk_busy = 0;
|
|
dtlk_major = register_chrdev(0, "dtlk", &dtlk_fops);
|
|
if (dtlk_major < 0) {
|
|
printk(KERN_ERR "DoubleTalk PC - cannot register device\n");
|
|
return dtlk_major;
|
|
}
|
|
err = dtlk_dev_probe();
|
|
if (err) {
|
|
unregister_chrdev(dtlk_major, "dtlk");
|
|
return err;
|
|
}
|
|
printk(", MAJOR %d\n", dtlk_major);
|
|
|
|
init_waitqueue_head(&dtlk_process_list);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
module_init(dtlk_init);
|
|
module_exit(dtlk_cleanup);
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
static int dtlk_readable(void)
|
|
{
|
|
#ifdef TRACING
|
|
printk(" dtlk_readable=%u@%u", inb_p(dtlk_port_lpc) != 0x7f, jiffies);
|
|
#endif
|
|
return inb_p(dtlk_port_lpc) != 0x7f;
|
|
}
|
|
|
|
static int dtlk_writeable(void)
|
|
{
|
|
/* TRACE_TEXT(" dtlk_writeable"); */
|
|
#ifdef TRACINGMORE
|
|
printk(" dtlk_writeable=%u", (inb_p(dtlk_port_tts) & TTS_WRITABLE)!=0);
|
|
#endif
|
|
return inb_p(dtlk_port_tts) & TTS_WRITABLE;
|
|
}
|
|
|
|
static int __init dtlk_dev_probe(void)
|
|
{
|
|
unsigned int testval = 0;
|
|
int i = 0;
|
|
struct dtlk_settings *sp;
|
|
|
|
if (dtlk_port_lpc | dtlk_port_tts)
|
|
return -EBUSY;
|
|
|
|
for (i = 0; dtlk_portlist[i]; i++) {
|
|
#if 0
|
|
printk("DoubleTalk PC - Port %03x = %04x\n",
|
|
dtlk_portlist[i], (testval = inw_p(dtlk_portlist[i])));
|
|
#endif
|
|
|
|
if (!request_region(dtlk_portlist[i], DTLK_IO_EXTENT,
|
|
"dtlk"))
|
|
continue;
|
|
testval = inw_p(dtlk_portlist[i]);
|
|
if ((testval &= 0xfbff) == 0x107f) {
|
|
dtlk_port_lpc = dtlk_portlist[i];
|
|
dtlk_port_tts = dtlk_port_lpc + 1;
|
|
|
|
sp = dtlk_interrogate();
|
|
printk("DoubleTalk PC at %03x-%03x, "
|
|
"ROM version %s, serial number %u",
|
|
dtlk_portlist[i], dtlk_portlist[i] +
|
|
DTLK_IO_EXTENT - 1,
|
|
sp->rom_version, sp->serial_number);
|
|
|
|
/* put LPC port into known state, so
|
|
dtlk_readable() gives valid result */
|
|
outb_p(0xff, dtlk_port_lpc);
|
|
|
|
/* INIT string and index marker */
|
|
dtlk_write_bytes("\036\1@\0\0012I\r", 8);
|
|
/* posting an index takes 18 msec. Here, we
|
|
wait up to 100 msec to see whether it
|
|
appears. */
|
|
msleep_interruptible(100);
|
|
dtlk_has_indexing = dtlk_readable();
|
|
#ifdef TRACING
|
|
printk(", indexing %d\n", dtlk_has_indexing);
|
|
#endif
|
|
#ifdef INSCOPE
|
|
{
|
|
/* This macro records ten samples read from the LPC port, for later display */
|
|
#define LOOK \
|
|
for (i = 0; i < 10; i++) \
|
|
{ \
|
|
buffer[b++] = inb_p(dtlk_port_lpc); \
|
|
__delay(loops_per_jiffy/(1000000/HZ)); \
|
|
}
|
|
char buffer[1000];
|
|
int b = 0, i, j;
|
|
|
|
LOOK
|
|
outb_p(0xff, dtlk_port_lpc);
|
|
buffer[b++] = 0;
|
|
LOOK
|
|
dtlk_write_bytes("\0012I\r", 4);
|
|
buffer[b++] = 0;
|
|
__delay(50 * loops_per_jiffy / (1000/HZ));
|
|
outb_p(0xff, dtlk_port_lpc);
|
|
buffer[b++] = 0;
|
|
LOOK
|
|
|
|
printk("\n");
|
|
for (j = 0; j < b; j++)
|
|
printk(" %02x", buffer[j]);
|
|
printk("\n");
|
|
}
|
|
#endif /* INSCOPE */
|
|
|
|
#ifdef OUTSCOPE
|
|
{
|
|
/* This macro records ten samples read from the TTS port, for later display */
|
|
#define LOOK \
|
|
for (i = 0; i < 10; i++) \
|
|
{ \
|
|
buffer[b++] = inb_p(dtlk_port_tts); \
|
|
__delay(loops_per_jiffy/(1000000/HZ)); /* 1 us */ \
|
|
}
|
|
char buffer[1000];
|
|
int b = 0, i, j;
|
|
|
|
mdelay(10); /* 10 ms */
|
|
LOOK
|
|
outb_p(0x03, dtlk_port_tts);
|
|
buffer[b++] = 0;
|
|
LOOK
|
|
LOOK
|
|
|
|
printk("\n");
|
|
for (j = 0; j < b; j++)
|
|
printk(" %02x", buffer[j]);
|
|
printk("\n");
|
|
}
|
|
#endif /* OUTSCOPE */
|
|
|
|
dtlk_write_bytes("Double Talk found", 18);
|
|
|
|
return 0;
|
|
}
|
|
release_region(dtlk_portlist[i], DTLK_IO_EXTENT);
|
|
}
|
|
|
|
printk(KERN_INFO "DoubleTalk PC - not found\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/*
|
|
static void dtlk_handle_error(char op, char rc, unsigned int minor)
|
|
{
|
|
printk(KERN_INFO"\nDoubleTalk PC - MINOR: %d, OPCODE: %d, ERROR: %d\n",
|
|
minor, op, rc);
|
|
return;
|
|
}
|
|
*/
|
|
|
|
/* interrogate the DoubleTalk PC and return its settings */
|
|
static struct dtlk_settings *dtlk_interrogate(void)
|
|
{
|
|
unsigned char *t;
|
|
static char buf[sizeof(struct dtlk_settings) + 1];
|
|
int total, i;
|
|
static struct dtlk_settings status;
|
|
TRACE_TEXT("(dtlk_interrogate");
|
|
dtlk_write_bytes("\030\001?", 3);
|
|
for (total = 0, i = 0; i < 50; i++) {
|
|
buf[total] = dtlk_read_tts();
|
|
if (total > 2 && buf[total] == 0x7f)
|
|
break;
|
|
if (total < sizeof(struct dtlk_settings))
|
|
total++;
|
|
}
|
|
/*
|
|
if (i==50) printk("interrogate() read overrun\n");
|
|
for (i=0; i<sizeof(buf); i++)
|
|
printk(" %02x", buf[i]);
|
|
printk("\n");
|
|
*/
|
|
t = buf;
|
|
status.serial_number = t[0] + t[1] * 256; /* serial number is
|
|
little endian */
|
|
t += 2;
|
|
|
|
i = 0;
|
|
while (*t != '\r') {
|
|
status.rom_version[i] = *t;
|
|
if (i < sizeof(status.rom_version) - 1)
|
|
i++;
|
|
t++;
|
|
}
|
|
status.rom_version[i] = 0;
|
|
t++;
|
|
|
|
status.mode = *t++;
|
|
status.punc_level = *t++;
|
|
status.formant_freq = *t++;
|
|
status.pitch = *t++;
|
|
status.speed = *t++;
|
|
status.volume = *t++;
|
|
status.tone = *t++;
|
|
status.expression = *t++;
|
|
status.ext_dict_loaded = *t++;
|
|
status.ext_dict_status = *t++;
|
|
status.free_ram = *t++;
|
|
status.articulation = *t++;
|
|
status.reverb = *t++;
|
|
status.eob = *t++;
|
|
status.has_indexing = dtlk_has_indexing;
|
|
TRACE_RET;
|
|
return &status;
|
|
}
|
|
|
|
static char dtlk_read_tts(void)
|
|
{
|
|
int portval, retries = 0;
|
|
char ch;
|
|
TRACE_TEXT("(dtlk_read_tts");
|
|
|
|
/* verify DT is ready, read char, wait for ACK */
|
|
do {
|
|
portval = inb_p(dtlk_port_tts);
|
|
} while ((portval & TTS_READABLE) == 0 &&
|
|
retries++ < DTLK_MAX_RETRIES);
|
|
if (retries > DTLK_MAX_RETRIES)
|
|
printk(KERN_ERR "dtlk_read_tts() timeout\n");
|
|
|
|
ch = inb_p(dtlk_port_tts); /* input from TTS port */
|
|
ch &= 0x7f;
|
|
outb_p(ch, dtlk_port_tts);
|
|
|
|
retries = 0;
|
|
do {
|
|
portval = inb_p(dtlk_port_tts);
|
|
} while ((portval & TTS_READABLE) != 0 &&
|
|
retries++ < DTLK_MAX_RETRIES);
|
|
if (retries > DTLK_MAX_RETRIES)
|
|
printk(KERN_ERR "dtlk_read_tts() timeout\n");
|
|
|
|
TRACE_RET;
|
|
return ch;
|
|
}
|
|
|
|
static char dtlk_read_lpc(void)
|
|
{
|
|
int retries = 0;
|
|
char ch;
|
|
TRACE_TEXT("(dtlk_read_lpc");
|
|
|
|
/* no need to test -- this is only called when the port is readable */
|
|
|
|
ch = inb_p(dtlk_port_lpc); /* input from LPC port */
|
|
|
|
outb_p(0xff, dtlk_port_lpc);
|
|
|
|
/* acknowledging a read takes 3-4
|
|
usec. Here, we wait up to 20 usec
|
|
for the acknowledgement */
|
|
retries = (loops_per_jiffy * 20) / (1000000/HZ);
|
|
while (inb_p(dtlk_port_lpc) != 0x7f && --retries > 0);
|
|
if (retries == 0)
|
|
printk(KERN_ERR "dtlk_read_lpc() timeout\n");
|
|
|
|
TRACE_RET;
|
|
return ch;
|
|
}
|
|
|
|
/* 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 char dtlk_write_tts(char ch)
|
|
{
|
|
int retries = 0;
|
|
#ifdef TRACINGMORE
|
|
printk(" dtlk_write_tts(");
|
|
if (' ' <= ch && ch <= '~')
|
|
printk("'%c'", ch);
|
|
else
|
|
printk("0x%02x", ch);
|
|
#endif
|
|
if (ch != DTLK_CLEAR) /* no flow control for CLEAR command */
|
|
while ((inb_p(dtlk_port_tts) & TTS_WRITABLE) == 0 &&
|
|
retries++ < DTLK_MAX_RETRIES) /* DT ready? */
|
|
;
|
|
if (retries > DTLK_MAX_RETRIES)
|
|
printk(KERN_ERR "dtlk_write_tts() timeout\n");
|
|
|
|
outb_p(ch, dtlk_port_tts); /* output to TTS port */
|
|
/* the RDY bit goes zero 2-3 usec after writing, and goes
|
|
1 again 180-190 usec later. Here, we wait up to 10
|
|
usec for the RDY bit to go zero. */
|
|
for (retries = 0; retries < loops_per_jiffy / (100000/HZ); retries++)
|
|
if ((inb_p(dtlk_port_tts) & TTS_WRITABLE) == 0)
|
|
break;
|
|
|
|
#ifdef TRACINGMORE
|
|
printk(")\n");
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|