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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- linux-c -*-
2 * dtlk.c - DoubleTalk PC driver for Linux
3 *
4 * Original author: Chris Pallotta <chris@allmedia.com>
5 * Current maintainer: Jim Van Zandt <jrv@vanzandt.mv.com>
6 *
7 * 2000-03-18 Jim Van Zandt: Fix polling.
8 * Eliminate dtlk_timer_active flag and separate dtlk_stop_timer
9 * function. Don't restart timer in dtlk_timer_tick. Restart timer
10 * in dtlk_poll after every poll. dtlk_poll returns mask (duh).
11 * Eliminate unused function dtlk_write_byte. Misc. code cleanups.
12 */
13
14/* This driver is for the DoubleTalk PC, a speech synthesizer
15 manufactured by RC Systems (http://www.rcsys.com/). It was written
16 based on documentation in their User's Manual file and Developer's
17 Tools disk.
18
19 The DoubleTalk PC contains four voice synthesizers: text-to-speech
20 (TTS), linear predictive coding (LPC), PCM/ADPCM, and CVSD. It
21 also has a tone generator. Output data for LPC are written to the
22 LPC port, and output data for the other modes are written to the
23 TTS port.
24
25 Two kinds of data can be read from the DoubleTalk: status
26 information (in response to the "\001?" interrogation command) is
27 read from the TTS port, and index markers (which mark the progress
28 of the speech) are read from the LPC port. Not all models of the
29 DoubleTalk PC implement index markers. Both the TTS and LPC ports
30 can also display status flags.
31
32 The DoubleTalk PC generates no interrupts.
33
34 These characteristics are mapped into the Unix stream I/O model as
35 follows:
36
37 "write" sends bytes to the TTS port. It is the responsibility of
38 the user program to switch modes among TTS, PCM/ADPCM, and CVSD.
39 This driver was written for use with the text-to-speech
40 synthesizer. If LPC output is needed some day, other minor device
41 numbers can be used to select among output modes.
42
43 "read" gets index markers from the LPC port. If the device does
44 not implement index markers, the read will fail with error EINVAL.
45
46 Status information is available using the DTLK_INTERROGATE ioctl.
47
48 */
49
50#include <linux/module.h>
51
52#define KERNEL
53#include <linux/types.h>
54#include <linux/fs.h>
Jesper Juhle49332b2005-05-01 08:59:08 -070055#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#include <linux/errno.h> /* for -EBUSY */
57#include <linux/ioport.h> /* for request_region */
58#include <linux/delay.h> /* for loops_per_jiffy */
Alexey Dobriyana99bbaf2009-10-04 16:11:37 +040059#include <linux/sched.h>
Arnd Bergmann613655f2010-06-02 14:28:52 +020060#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#include <asm/io.h> /* for inb_p, outb_p, inb, outb, etc. */
62#include <asm/uaccess.h> /* for get_user, etc. */
63#include <linux/wait.h> /* for wait_queue */
64#include <linux/init.h> /* for __init, module_{init,exit} */
65#include <linux/poll.h> /* for POLLIN, etc. */
66#include <linux/dtlk.h> /* local header file for DoubleTalk values */
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68#ifdef TRACING
69#define TRACE_TEXT(str) printk(str);
70#define TRACE_RET printk(")")
71#else /* !TRACING */
72#define TRACE_TEXT(str) ((void) 0)
73#define TRACE_RET ((void) 0)
74#endif /* TRACING */
75
Arnd Bergmann613655f2010-06-02 14:28:52 +020076static DEFINE_MUTEX(dtlk_mutex);
Jiri Slaby40565f12007-02-12 00:52:31 -080077static void dtlk_timer_tick(unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79static int dtlk_major;
80static int dtlk_port_lpc;
81static int dtlk_port_tts;
82static int dtlk_busy;
83static int dtlk_has_indexing;
84static unsigned int dtlk_portlist[] =
85{0x25e, 0x29e, 0x2de, 0x31e, 0x35e, 0x39e, 0};
86static wait_queue_head_t dtlk_process_list;
Jiri Slaby40565f12007-02-12 00:52:31 -080087static DEFINE_TIMER(dtlk_timer, dtlk_timer_tick, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
89/* prototypes for file_operations struct */
90static ssize_t dtlk_read(struct file *, char __user *,
91 size_t nbytes, loff_t * ppos);
92static ssize_t dtlk_write(struct file *, const char __user *,
93 size_t nbytes, loff_t * ppos);
94static unsigned int dtlk_poll(struct file *, poll_table *);
95static int dtlk_open(struct inode *, struct file *);
96static int dtlk_release(struct inode *, struct file *);
Arnd Bergmann55929332010-04-27 00:24:05 +020097static long dtlk_ioctl(struct file *file,
98 unsigned int cmd, unsigned long arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
Arjan van de Ven62322d22006-07-03 00:24:21 -0700100static const struct file_operations dtlk_fops =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101{
102 .owner = THIS_MODULE,
103 .read = dtlk_read,
104 .write = dtlk_write,
105 .poll = dtlk_poll,
Arnd Bergmann55929332010-04-27 00:24:05 +0200106 .unlocked_ioctl = dtlk_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 .open = dtlk_open,
108 .release = dtlk_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200109 .llseek = no_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110};
111
112/* local prototypes */
113static int dtlk_dev_probe(void);
114static struct dtlk_settings *dtlk_interrogate(void);
115static int dtlk_readable(void);
116static char dtlk_read_lpc(void);
117static char dtlk_read_tts(void);
118static int dtlk_writeable(void);
119static char dtlk_write_bytes(const char *buf, int n);
120static char dtlk_write_tts(char);
121/*
122 static void dtlk_handle_error(char, char, unsigned int);
123 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125static ssize_t dtlk_read(struct file *file, char __user *buf,
126 size_t count, loff_t * ppos)
127{
Josef Sipeka7113a92006-12-08 02:36:55 -0800128 unsigned int minor = iminor(file->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 char ch;
130 int i = 0, retries;
131
132 TRACE_TEXT("(dtlk_read");
133 /* printk("DoubleTalk PC - dtlk_read()\n"); */
134
135 if (minor != DTLK_MINOR || !dtlk_has_indexing)
136 return -EINVAL;
137
138 for (retries = 0; retries < loops_per_jiffy; retries++) {
139 while (i < count && dtlk_readable()) {
140 ch = dtlk_read_lpc();
141 /* printk("dtlk_read() reads 0x%02x\n", ch); */
142 if (put_user(ch, buf++))
143 return -EFAULT;
144 i++;
145 }
146 if (i)
147 return i;
148 if (file->f_flags & O_NONBLOCK)
149 break;
150 msleep_interruptible(100);
151 }
152 if (retries == loops_per_jiffy)
153 printk(KERN_ERR "dtlk_read times out\n");
154 TRACE_RET;
155 return -EAGAIN;
156}
157
158static ssize_t dtlk_write(struct file *file, const char __user *buf,
159 size_t count, loff_t * ppos)
160{
161 int i = 0, retries = 0, ch;
162
163 TRACE_TEXT("(dtlk_write");
164#ifdef TRACING
165 printk(" \"");
166 {
167 int i, ch;
168 for (i = 0; i < count; i++) {
169 if (get_user(ch, buf + i))
170 return -EFAULT;
171 if (' ' <= ch && ch <= '~')
172 printk("%c", ch);
173 else
174 printk("\\%03o", ch);
175 }
176 printk("\"");
177 }
178#endif
179
Josef Sipeka7113a92006-12-08 02:36:55 -0800180 if (iminor(file->f_path.dentry->d_inode) != DTLK_MINOR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 return -EINVAL;
182
183 while (1) {
184 while (i < count && !get_user(ch, buf) &&
185 (ch == DTLK_CLEAR || dtlk_writeable())) {
186 dtlk_write_tts(ch);
187 buf++;
188 i++;
189 if (i % 5 == 0)
190 /* We yield our time until scheduled
191 again. This reduces the transfer
192 rate to 500 bytes/sec, but that's
193 still enough to keep up with the
194 speech synthesizer. */
195 msleep_interruptible(1);
196 else {
197 /* the RDY bit goes zero 2-3 usec
198 after writing, and goes 1 again
199 180-190 usec later. Here, we wait
200 up to 250 usec for the RDY bit to
201 go nonzero. */
202 for (retries = 0;
203 retries < loops_per_jiffy / (4000/HZ);
204 retries++)
205 if (inb_p(dtlk_port_tts) &
206 TTS_WRITABLE)
207 break;
208 }
209 retries = 0;
210 }
211 if (i == count)
212 return i;
213 if (file->f_flags & O_NONBLOCK)
214 break;
215
216 msleep_interruptible(1);
217
218 if (++retries > 10 * HZ) { /* wait no more than 10 sec
219 from last write */
220 printk("dtlk: write timeout. "
221 "inb_p(dtlk_port_tts) = 0x%02x\n",
222 inb_p(dtlk_port_tts));
223 TRACE_RET;
224 return -EBUSY;
225 }
226 }
227 TRACE_RET;
228 return -EAGAIN;
229}
230
231static unsigned int dtlk_poll(struct file *file, poll_table * wait)
232{
233 int mask = 0;
234 unsigned long expires;
235
236 TRACE_TEXT(" dtlk_poll");
237 /*
238 static long int j;
239 printk(".");
240 printk("<%ld>", jiffies-j);
241 j=jiffies;
242 */
243 poll_wait(file, &dtlk_process_list, wait);
244
245 if (dtlk_has_indexing && dtlk_readable()) {
246 del_timer(&dtlk_timer);
247 mask = POLLIN | POLLRDNORM;
248 }
249 if (dtlk_writeable()) {
250 del_timer(&dtlk_timer);
251 mask |= POLLOUT | POLLWRNORM;
252 }
253 /* there are no exception conditions */
254
255 /* There won't be any interrupts, so we set a timer instead. */
256 expires = jiffies + 3*HZ / 100;
257 mod_timer(&dtlk_timer, expires);
258
259 return mask;
260}
261
262static void dtlk_timer_tick(unsigned long data)
263{
264 TRACE_TEXT(" dtlk_timer_tick");
265 wake_up_interruptible(&dtlk_process_list);
266}
267
Arnd Bergmann55929332010-04-27 00:24:05 +0200268static long dtlk_ioctl(struct file *file,
269 unsigned int cmd,
270 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
272 char __user *argp = (char __user *)arg;
273 struct dtlk_settings *sp;
274 char portval;
275 TRACE_TEXT(" dtlk_ioctl");
276
277 switch (cmd) {
278
279 case DTLK_INTERROGATE:
Arnd Bergmann613655f2010-06-02 14:28:52 +0200280 mutex_lock(&dtlk_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 sp = dtlk_interrogate();
Arnd Bergmann613655f2010-06-02 14:28:52 +0200282 mutex_unlock(&dtlk_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 if (copy_to_user(argp, sp, sizeof(struct dtlk_settings)))
284 return -EINVAL;
285 return 0;
286
287 case DTLK_STATUS:
288 portval = inb_p(dtlk_port_tts);
289 return put_user(portval, argp);
290
291 default:
292 return -EINVAL;
293 }
294}
295
Jonathan Corbetf2b98572008-05-18 15:32:43 -0600296/* Note that nobody ever sets dtlk_busy... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297static int dtlk_open(struct inode *inode, struct file *file)
298{
299 TRACE_TEXT("(dtlk_open");
300
301 nonseekable_open(inode, file);
302 switch (iminor(inode)) {
303 case DTLK_MINOR:
304 if (dtlk_busy)
305 return -EBUSY;
306 return nonseekable_open(inode, file);
307
308 default:
309 return -ENXIO;
310 }
311}
312
313static int dtlk_release(struct inode *inode, struct file *file)
314{
315 TRACE_TEXT("(dtlk_release");
316
317 switch (iminor(inode)) {
318 case DTLK_MINOR:
319 break;
320
321 default:
322 break;
323 }
324 TRACE_RET;
325
Jiri Slaby40565f12007-02-12 00:52:31 -0800326 del_timer_sync(&dtlk_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
328 return 0;
329}
330
331static int __init dtlk_init(void)
332{
Akinobu Mitab2bbe382007-05-08 00:29:18 -0700333 int err;
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 dtlk_port_lpc = 0;
336 dtlk_port_tts = 0;
337 dtlk_busy = 0;
338 dtlk_major = register_chrdev(0, "dtlk", &dtlk_fops);
Akinobu Mitab2bbe382007-05-08 00:29:18 -0700339 if (dtlk_major < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 printk(KERN_ERR "DoubleTalk PC - cannot register device\n");
Akinobu Mitab2bbe382007-05-08 00:29:18 -0700341 return dtlk_major;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 }
Akinobu Mitab2bbe382007-05-08 00:29:18 -0700343 err = dtlk_dev_probe();
344 if (err) {
345 unregister_chrdev(dtlk_major, "dtlk");
346 return err;
347 }
348 printk(", MAJOR %d\n", dtlk_major);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 init_waitqueue_head(&dtlk_process_list);
351
352 return 0;
353}
354
355static void __exit dtlk_cleanup (void)
356{
357 dtlk_write_bytes("goodbye", 8);
358 msleep_interruptible(500); /* nap 0.50 sec but
359 could be awakened
360 earlier by
361 signals... */
362
363 dtlk_write_tts(DTLK_CLEAR);
364 unregister_chrdev(dtlk_major, "dtlk");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 release_region(dtlk_port_lpc, DTLK_IO_EXTENT);
366}
367
368module_init(dtlk_init);
369module_exit(dtlk_cleanup);
370
371/* ------------------------------------------------------------------------ */
372
373static int dtlk_readable(void)
374{
375#ifdef TRACING
376 printk(" dtlk_readable=%u@%u", inb_p(dtlk_port_lpc) != 0x7f, jiffies);
377#endif
378 return inb_p(dtlk_port_lpc) != 0x7f;
379}
380
381static int dtlk_writeable(void)
382{
383 /* TRACE_TEXT(" dtlk_writeable"); */
384#ifdef TRACINGMORE
385 printk(" dtlk_writeable=%u", (inb_p(dtlk_port_tts) & TTS_WRITABLE)!=0);
386#endif
387 return inb_p(dtlk_port_tts) & TTS_WRITABLE;
388}
389
390static int __init dtlk_dev_probe(void)
391{
392 unsigned int testval = 0;
393 int i = 0;
394 struct dtlk_settings *sp;
395
396 if (dtlk_port_lpc | dtlk_port_tts)
397 return -EBUSY;
398
399 for (i = 0; dtlk_portlist[i]; i++) {
400#if 0
401 printk("DoubleTalk PC - Port %03x = %04x\n",
402 dtlk_portlist[i], (testval = inw_p(dtlk_portlist[i])));
403#endif
404
405 if (!request_region(dtlk_portlist[i], DTLK_IO_EXTENT,
406 "dtlk"))
407 continue;
408 testval = inw_p(dtlk_portlist[i]);
409 if ((testval &= 0xfbff) == 0x107f) {
410 dtlk_port_lpc = dtlk_portlist[i];
411 dtlk_port_tts = dtlk_port_lpc + 1;
412
413 sp = dtlk_interrogate();
414 printk("DoubleTalk PC at %03x-%03x, "
415 "ROM version %s, serial number %u",
416 dtlk_portlist[i], dtlk_portlist[i] +
417 DTLK_IO_EXTENT - 1,
418 sp->rom_version, sp->serial_number);
419
420 /* put LPC port into known state, so
421 dtlk_readable() gives valid result */
422 outb_p(0xff, dtlk_port_lpc);
423
424 /* INIT string and index marker */
425 dtlk_write_bytes("\036\1@\0\0012I\r", 8);
426 /* posting an index takes 18 msec. Here, we
427 wait up to 100 msec to see whether it
428 appears. */
429 msleep_interruptible(100);
430 dtlk_has_indexing = dtlk_readable();
431#ifdef TRACING
432 printk(", indexing %d\n", dtlk_has_indexing);
433#endif
434#ifdef INSCOPE
435 {
436/* This macro records ten samples read from the LPC port, for later display */
437#define LOOK \
438for (i = 0; i < 10; i++) \
439 { \
440 buffer[b++] = inb_p(dtlk_port_lpc); \
441 __delay(loops_per_jiffy/(1000000/HZ)); \
442 }
443 char buffer[1000];
444 int b = 0, i, j;
445
446 LOOK
447 outb_p(0xff, dtlk_port_lpc);
448 buffer[b++] = 0;
449 LOOK
450 dtlk_write_bytes("\0012I\r", 4);
451 buffer[b++] = 0;
452 __delay(50 * loops_per_jiffy / (1000/HZ));
453 outb_p(0xff, dtlk_port_lpc);
454 buffer[b++] = 0;
455 LOOK
456
457 printk("\n");
458 for (j = 0; j < b; j++)
459 printk(" %02x", buffer[j]);
460 printk("\n");
461 }
462#endif /* INSCOPE */
463
464#ifdef OUTSCOPE
465 {
466/* This macro records ten samples read from the TTS port, for later display */
467#define LOOK \
468for (i = 0; i < 10; i++) \
469 { \
470 buffer[b++] = inb_p(dtlk_port_tts); \
471 __delay(loops_per_jiffy/(1000000/HZ)); /* 1 us */ \
472 }
473 char buffer[1000];
474 int b = 0, i, j;
475
476 mdelay(10); /* 10 ms */
477 LOOK
478 outb_p(0x03, dtlk_port_tts);
479 buffer[b++] = 0;
480 LOOK
481 LOOK
482
483 printk("\n");
484 for (j = 0; j < b; j++)
485 printk(" %02x", buffer[j]);
486 printk("\n");
487 }
488#endif /* OUTSCOPE */
489
490 dtlk_write_bytes("Double Talk found", 18);
491
492 return 0;
493 }
494 release_region(dtlk_portlist[i], DTLK_IO_EXTENT);
495 }
496
Dave Jones49b6e2a2006-04-10 22:54:06 -0700497 printk(KERN_INFO "DoubleTalk PC - not found\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 return -ENODEV;
499}
500
501/*
502 static void dtlk_handle_error(char op, char rc, unsigned int minor)
503 {
504 printk(KERN_INFO"\nDoubleTalk PC - MINOR: %d, OPCODE: %d, ERROR: %d\n",
505 minor, op, rc);
506 return;
507 }
508 */
509
510/* interrogate the DoubleTalk PC and return its settings */
511static struct dtlk_settings *dtlk_interrogate(void)
512{
513 unsigned char *t;
514 static char buf[sizeof(struct dtlk_settings) + 1];
515 int total, i;
516 static struct dtlk_settings status;
517 TRACE_TEXT("(dtlk_interrogate");
518 dtlk_write_bytes("\030\001?", 3);
519 for (total = 0, i = 0; i < 50; i++) {
520 buf[total] = dtlk_read_tts();
521 if (total > 2 && buf[total] == 0x7f)
522 break;
523 if (total < sizeof(struct dtlk_settings))
524 total++;
525 }
526 /*
527 if (i==50) printk("interrogate() read overrun\n");
528 for (i=0; i<sizeof(buf); i++)
529 printk(" %02x", buf[i]);
530 printk("\n");
531 */
532 t = buf;
533 status.serial_number = t[0] + t[1] * 256; /* serial number is
534 little endian */
535 t += 2;
536
537 i = 0;
538 while (*t != '\r') {
539 status.rom_version[i] = *t;
540 if (i < sizeof(status.rom_version) - 1)
541 i++;
542 t++;
543 }
544 status.rom_version[i] = 0;
545 t++;
546
547 status.mode = *t++;
548 status.punc_level = *t++;
549 status.formant_freq = *t++;
550 status.pitch = *t++;
551 status.speed = *t++;
552 status.volume = *t++;
553 status.tone = *t++;
554 status.expression = *t++;
555 status.ext_dict_loaded = *t++;
556 status.ext_dict_status = *t++;
557 status.free_ram = *t++;
558 status.articulation = *t++;
559 status.reverb = *t++;
560 status.eob = *t++;
561 status.has_indexing = dtlk_has_indexing;
562 TRACE_RET;
563 return &status;
564}
565
566static char dtlk_read_tts(void)
567{
568 int portval, retries = 0;
569 char ch;
570 TRACE_TEXT("(dtlk_read_tts");
571
572 /* verify DT is ready, read char, wait for ACK */
573 do {
574 portval = inb_p(dtlk_port_tts);
575 } while ((portval & TTS_READABLE) == 0 &&
576 retries++ < DTLK_MAX_RETRIES);
Roel Kluin4390b9e2009-06-18 16:49:13 -0700577 if (retries > DTLK_MAX_RETRIES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 printk(KERN_ERR "dtlk_read_tts() timeout\n");
579
580 ch = inb_p(dtlk_port_tts); /* input from TTS port */
581 ch &= 0x7f;
582 outb_p(ch, dtlk_port_tts);
583
584 retries = 0;
585 do {
586 portval = inb_p(dtlk_port_tts);
587 } while ((portval & TTS_READABLE) != 0 &&
588 retries++ < DTLK_MAX_RETRIES);
Roel Kluin4390b9e2009-06-18 16:49:13 -0700589 if (retries > DTLK_MAX_RETRIES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 printk(KERN_ERR "dtlk_read_tts() timeout\n");
591
592 TRACE_RET;
593 return ch;
594}
595
596static char dtlk_read_lpc(void)
597{
598 int retries = 0;
599 char ch;
600 TRACE_TEXT("(dtlk_read_lpc");
601
602 /* no need to test -- this is only called when the port is readable */
603
604 ch = inb_p(dtlk_port_lpc); /* input from LPC port */
605
606 outb_p(0xff, dtlk_port_lpc);
607
608 /* acknowledging a read takes 3-4
609 usec. Here, we wait up to 20 usec
610 for the acknowledgement */
611 retries = (loops_per_jiffy * 20) / (1000000/HZ);
612 while (inb_p(dtlk_port_lpc) != 0x7f && --retries > 0);
613 if (retries == 0)
614 printk(KERN_ERR "dtlk_read_lpc() timeout\n");
615
616 TRACE_RET;
617 return ch;
618}
619
620/* write n bytes to tts port */
621static char dtlk_write_bytes(const char *buf, int n)
622{
623 char val = 0;
624 /* printk("dtlk_write_bytes(\"%-*s\", %d)\n", n, buf, n); */
625 TRACE_TEXT("(dtlk_write_bytes");
626 while (n-- > 0)
627 val = dtlk_write_tts(*buf++);
628 TRACE_RET;
629 return val;
630}
631
632static char dtlk_write_tts(char ch)
633{
634 int retries = 0;
635#ifdef TRACINGMORE
636 printk(" dtlk_write_tts(");
637 if (' ' <= ch && ch <= '~')
638 printk("'%c'", ch);
639 else
640 printk("0x%02x", ch);
641#endif
642 if (ch != DTLK_CLEAR) /* no flow control for CLEAR command */
643 while ((inb_p(dtlk_port_tts) & TTS_WRITABLE) == 0 &&
644 retries++ < DTLK_MAX_RETRIES) /* DT ready? */
645 ;
Roel Kluin4390b9e2009-06-18 16:49:13 -0700646 if (retries > DTLK_MAX_RETRIES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 printk(KERN_ERR "dtlk_write_tts() timeout\n");
648
649 outb_p(ch, dtlk_port_tts); /* output to TTS port */
650 /* the RDY bit goes zero 2-3 usec after writing, and goes
651 1 again 180-190 usec later. Here, we wait up to 10
652 usec for the RDY bit to go zero. */
653 for (retries = 0; retries < loops_per_jiffy / (100000/HZ); retries++)
654 if ((inb_p(dtlk_port_tts) & TTS_WRITABLE) == 0)
655 break;
656
657#ifdef TRACINGMORE
658 printk(")\n");
659#endif
660 return 0;
661}
662
663MODULE_LICENSE("GPL");