2 * Copyright 2003 Digi International (www.digi.com)
3 * Scott H Kilau <Scott_Kilau at digi dot com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2, or (at your option)
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
13 * PURPOSE. See the GNU General Public License for more details.
17 * This file implements the tty driver functionality for the
18 * Neo and ClassicBoard PCI based product lines.
21 #include <linux/kernel.h>
22 #include <linux/sched/signal.h> /* For jiffies, task states, etc. */
23 #include <linux/interrupt.h> /* For tasklet and interrupt structs/defines */
24 #include <linux/module.h>
25 #include <linux/ctype.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28 #include <linux/types.h>
29 #include <linux/serial_reg.h>
30 #include <linux/slab.h>
31 #include <linux/delay.h> /* For udelay */
32 #include <linux/uaccess.h> /* For copy_from_user/copy_to_user */
33 #include <linux/pci.h>
34 #include "dgnc_driver.h"
38 #include "dgnc_utils.h"
40 /* Default transparent print information. */
42 static const struct digi_t dgnc_digi_init = {
43 .digi_flags = DIGI_COOK, /* Flags */
44 .digi_maxcps = 100, /* Max CPS */
45 .digi_maxchar = 50, /* Max chars in print queue */
46 .digi_bufsize = 100, /* Printer buffer size */
47 .digi_onlen = 4, /* size of printer on string */
48 .digi_offlen = 4, /* size of printer off string */
49 .digi_onstr = "\033[5i", /* ANSI printer on string ] */
50 .digi_offstr = "\033[4i", /* ANSI printer off string ] */
51 .digi_term = "ansi" /* default terminal type */
55 * Define a local default termios struct. All ports will be created
56 * with this termios initially.
58 * This defines a raw port at 9600 baud, 8 data bits, no parity,
61 static const struct ktermios default_termios = {
62 .c_iflag = (DEFAULT_IFLAGS), /* iflags */
63 .c_oflag = (DEFAULT_OFLAGS), /* oflags */
64 .c_cflag = (DEFAULT_CFLAGS), /* cflags */
65 .c_lflag = (DEFAULT_LFLAGS), /* lflags */
70 /* Our function prototypes */
71 static int dgnc_tty_open(struct tty_struct *tty, struct file *file);
72 static void dgnc_tty_close(struct tty_struct *tty, struct file *file);
73 static int dgnc_block_til_ready(struct tty_struct *tty, struct file *file,
74 struct channel_t *ch);
75 static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
77 static int dgnc_tty_digigeta(struct tty_struct *tty,
78 struct digi_t __user *retinfo);
79 static int dgnc_tty_digiseta(struct tty_struct *tty,
80 struct digi_t __user *new_info);
81 static int dgnc_tty_write_room(struct tty_struct *tty);
82 static int dgnc_tty_put_char(struct tty_struct *tty, unsigned char c);
83 static int dgnc_tty_chars_in_buffer(struct tty_struct *tty);
84 static void dgnc_tty_start(struct tty_struct *tty);
85 static void dgnc_tty_stop(struct tty_struct *tty);
86 static void dgnc_tty_throttle(struct tty_struct *tty);
87 static void dgnc_tty_unthrottle(struct tty_struct *tty);
88 static void dgnc_tty_flush_chars(struct tty_struct *tty);
89 static void dgnc_tty_flush_buffer(struct tty_struct *tty);
90 static void dgnc_tty_hangup(struct tty_struct *tty);
91 static int dgnc_set_modem_info(struct channel_t *ch, unsigned int command,
92 unsigned int __user *value);
93 static int dgnc_get_modem_info(struct channel_t *ch,
94 unsigned int __user *value);
95 static int dgnc_tty_tiocmget(struct tty_struct *tty);
96 static int dgnc_tty_tiocmset(struct tty_struct *tty, unsigned int set,
98 static int dgnc_tty_send_break(struct tty_struct *tty, int msec);
99 static void dgnc_tty_wait_until_sent(struct tty_struct *tty, int timeout);
100 static int dgnc_tty_write(struct tty_struct *tty, const unsigned char *buf,
102 static void dgnc_tty_set_termios(struct tty_struct *tty,
103 struct ktermios *old_termios);
104 static void dgnc_tty_send_xchar(struct tty_struct *tty, char ch);
105 static void dgnc_set_signal_low(struct channel_t *ch, const unsigned char line);
106 static void dgnc_wake_up_unit(struct un_t *unit);
108 static const struct tty_operations dgnc_tty_ops = {
109 .open = dgnc_tty_open,
110 .close = dgnc_tty_close,
111 .write = dgnc_tty_write,
112 .write_room = dgnc_tty_write_room,
113 .flush_buffer = dgnc_tty_flush_buffer,
114 .chars_in_buffer = dgnc_tty_chars_in_buffer,
115 .flush_chars = dgnc_tty_flush_chars,
116 .ioctl = dgnc_tty_ioctl,
117 .set_termios = dgnc_tty_set_termios,
118 .stop = dgnc_tty_stop,
119 .start = dgnc_tty_start,
120 .throttle = dgnc_tty_throttle,
121 .unthrottle = dgnc_tty_unthrottle,
122 .hangup = dgnc_tty_hangup,
123 .put_char = dgnc_tty_put_char,
124 .tiocmget = dgnc_tty_tiocmget,
125 .tiocmset = dgnc_tty_tiocmset,
126 .break_ctl = dgnc_tty_send_break,
127 .wait_until_sent = dgnc_tty_wait_until_sent,
128 .send_xchar = dgnc_tty_send_xchar
131 /* TTY Initialization/Cleanup Functions */
134 * dgnc_tty_register()
136 * Init the tty subsystem for this board.
138 int dgnc_tty_register(struct dgnc_board *brd)
142 brd->serial_driver = tty_alloc_driver(brd->maxports,
143 TTY_DRIVER_REAL_RAW |
144 TTY_DRIVER_DYNAMIC_DEV |
145 TTY_DRIVER_HARDWARE_BREAK);
146 if (IS_ERR(brd->serial_driver))
147 return PTR_ERR(brd->serial_driver);
149 snprintf(brd->serial_name, MAXTTYNAMELEN, "tty_dgnc_%d_",
152 brd->serial_driver->name = brd->serial_name;
153 brd->serial_driver->name_base = 0;
154 brd->serial_driver->major = 0;
155 brd->serial_driver->minor_start = 0;
156 brd->serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
157 brd->serial_driver->subtype = SERIAL_TYPE_NORMAL;
158 brd->serial_driver->init_termios = default_termios;
159 brd->serial_driver->driver_name = DRVSTR;
162 * Entry points for driver. Called by the kernel from
163 * tty_io.c and n_tty.c.
165 tty_set_operations(brd->serial_driver, &dgnc_tty_ops);
167 rc = tty_register_driver(brd->serial_driver);
169 dev_dbg(&brd->pdev->dev,
170 "Can't register tty device (%d)\n", rc);
171 goto free_serial_driver;
175 * If we're doing transparent print, we have to do all of the above
176 * again, separately so we don't get the LD confused about what major
177 * we are when we get into the dgnc_tty_open() routine.
179 brd->print_driver = tty_alloc_driver(brd->maxports,
180 TTY_DRIVER_REAL_RAW |
181 TTY_DRIVER_DYNAMIC_DEV |
182 TTY_DRIVER_HARDWARE_BREAK);
183 if (IS_ERR(brd->print_driver)) {
184 rc = PTR_ERR(brd->print_driver);
185 goto unregister_serial_driver;
188 snprintf(brd->print_name, MAXTTYNAMELEN, "pr_dgnc_%d_", brd->boardnum);
190 brd->print_driver->name = brd->print_name;
191 brd->print_driver->name_base = 0;
192 brd->print_driver->major = brd->serial_driver->major;
193 brd->print_driver->minor_start = 0x80;
194 brd->print_driver->type = TTY_DRIVER_TYPE_SERIAL;
195 brd->print_driver->subtype = SERIAL_TYPE_NORMAL;
196 brd->print_driver->init_termios = default_termios;
197 brd->print_driver->driver_name = DRVSTR;
200 * Entry points for driver. Called by the kernel from
201 * tty_io.c and n_tty.c.
203 tty_set_operations(brd->print_driver, &dgnc_tty_ops);
205 rc = tty_register_driver(brd->print_driver);
207 dev_dbg(&brd->pdev->dev,
208 "Can't register Transparent Print device(%d)\n",
210 goto free_print_driver;
216 put_tty_driver(brd->print_driver);
217 unregister_serial_driver:
218 tty_unregister_driver(brd->serial_driver);
220 put_tty_driver(brd->serial_driver);
224 void dgnc_tty_unregister(struct dgnc_board *brd)
226 tty_unregister_driver(brd->print_driver);
227 tty_unregister_driver(brd->serial_driver);
228 put_tty_driver(brd->print_driver);
229 put_tty_driver(brd->serial_driver);
235 * Init the tty subsystem. Called once per board after board has been
236 * downloaded and init'ed.
238 int dgnc_tty_init(struct dgnc_board *brd)
243 struct channel_t *ch;
248 /* Initialize board structure elements. */
250 vaddr = brd->re_map_membase;
252 brd->nasync = brd->maxports;
254 for (i = 0; i < brd->nasync; i++) {
256 * Okay to malloc with GFP_KERNEL, we are not at
257 * interrupt context, and there are no locks held.
259 brd->channels[i] = kzalloc(sizeof(*brd->channels[i]),
261 if (!brd->channels[i]) {
263 goto err_free_channels;
267 ch = brd->channels[0];
268 vaddr = brd->re_map_membase;
270 /* Set up channel variables */
271 for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
272 spin_lock_init(&ch->ch_lock);
274 /* Store all our magic numbers */
275 ch->magic = DGNC_CHANNEL_MAGIC;
276 ch->ch_tun.magic = DGNC_UNIT_MAGIC;
277 ch->ch_tun.un_ch = ch;
278 ch->ch_tun.un_type = DGNC_SERIAL;
279 ch->ch_tun.un_dev = i;
281 ch->ch_pun.magic = DGNC_UNIT_MAGIC;
282 ch->ch_pun.un_ch = ch;
283 ch->ch_pun.un_type = DGNC_PRINT;
284 ch->ch_pun.un_dev = i + 128;
286 if (brd->bd_uart_offset == 0x200)
287 ch->ch_neo_uart = vaddr + (brd->bd_uart_offset * i);
289 ch->ch_cls_uart = vaddr + (brd->bd_uart_offset * i);
293 ch->ch_digi = dgnc_digi_init;
295 /* .25 second delay */
296 ch->ch_close_delay = 250;
298 init_waitqueue_head(&ch->ch_flags_wait);
299 init_waitqueue_head(&ch->ch_tun.un_flags_wait);
300 init_waitqueue_head(&ch->ch_pun.un_flags_wait);
303 struct device *classp;
305 classp = tty_register_device(brd->serial_driver, i,
306 &ch->ch_bd->pdev->dev);
307 ch->ch_tun.un_sysfs = classp;
309 classp = tty_register_device(brd->print_driver, i,
310 &ch->ch_bd->pdev->dev);
311 ch->ch_pun.un_sysfs = classp;
318 for (i = i - 1; i >= 0; --i) {
319 kfree(brd->channels[i]);
320 brd->channels[i] = NULL;
328 * Uninitialize the TTY portion of this driver. Free all memory and
331 void dgnc_cleanup_tty(struct dgnc_board *brd)
335 for (i = 0; i < brd->nasync; i++)
336 tty_unregister_device(brd->serial_driver, i);
338 tty_unregister_driver(brd->serial_driver);
340 for (i = 0; i < brd->nasync; i++)
341 tty_unregister_device(brd->print_driver, i);
343 tty_unregister_driver(brd->print_driver);
345 put_tty_driver(brd->serial_driver);
346 put_tty_driver(brd->print_driver);
350 * dgnc_wmove - Write data to transmit queue.
352 * ch - Pointer to channel structure.
353 * buf - Pointer to characters to be moved.
354 * n - Number of characters to move.
356 static void dgnc_wmove(struct channel_t *ch, char *buf, uint n)
361 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
364 head = ch->ch_w_head & WQUEUEMASK;
367 * If the write wraps over the top of the circular buffer,
368 * move the portion up to the wrap point, and reset the
369 * pointers to the bottom.
371 remain = WQUEUESIZE - head;
375 memcpy(ch->ch_wqueue + head, buf, remain);
381 /* Move rest of data. */
383 memcpy(ch->ch_wqueue + head, buf, remain);
388 ch->ch_w_head = head;
392 * dgnc_input - Process received data.
394 * ch - Pointer to channel structure.
396 void dgnc_input(struct channel_t *ch)
398 struct dgnc_board *bd;
399 struct tty_struct *tp;
400 struct tty_ldisc *ld = NULL;
412 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
415 tp = ch->ch_tun.un_tty;
418 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
421 spin_lock_irqsave(&ch->ch_lock, flags);
424 * Figure the number of characters in the buffer.
425 * Exit immediately if none.
428 head = ch->ch_r_head & rmask;
429 tail = ch->ch_r_tail & rmask;
430 data_len = (head - tail) & rmask;
436 * If the device is not open, or CREAD is off,
437 * flush input data and return immediately.
439 if (!tp || (tp->magic != TTY_MAGIC) ||
440 !(ch->ch_tun.un_flags & UN_ISOPEN) ||
442 (ch->ch_tun.un_flags & UN_CLOSING)) {
443 ch->ch_r_head = tail;
445 /* Force queue flow control to be released, if needed */
446 dgnc_check_queue_flow_control(ch);
451 /* If we are throttled, simply don't read any data. */
453 if (ch->ch_flags & CH_FORCED_STOPI)
456 flip_len = TTY_FLIPBUF_SIZE;
458 /* Chop down the length, if needed */
459 len = min(data_len, flip_len);
460 len = min(len, (N_TTY_BUF_SIZE - 1));
462 ld = tty_ldisc_ref(tp);
465 * If we were unable to get a reference to the ld,
466 * don't flush our buffer, and act like the ld doesn't
467 * have any space to put the data right now.
473 * If ld doesn't have a pointer to a receive_buf function,
474 * flush the data, then act like the ld doesn't have any
475 * space to put the data right now.
477 if (!ld->ops->receive_buf) {
478 ch->ch_r_head = ch->ch_r_tail;
487 * The tty layer in the kernel has changed in 2.6.16+.
489 * The flip buffers in the tty structure are no longer exposed,
490 * and probably will be going away eventually.
492 * If we are completely raw, we don't need to go through a lot
493 * of the tty layers that exist.
494 * In this case, we take the shortest and fastest route we
495 * can to relay the data to the user.
497 * On the other hand, if we are not raw, we need to go through
498 * the new 2.6.16+ tty layer, which has its API more well defined.
500 len = tty_buffer_request_room(tp->port, len);
504 * n now contains the most amount of data we can copy,
505 * bounded either by how much the Linux tty layer can handle,
506 * or the amount of data the card actually has pending...
509 unsigned char *ch_pos = ch->ch_equeue + tail;
511 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
518 * If conditions are such that ld needs to see all
519 * UART errors, we will have to walk each character
520 * and error byte and send them to the buffer one at
523 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
524 for (i = 0; i < s; i++) {
525 unsigned char ch = *(ch_pos + i);
526 char flag = TTY_NORMAL;
528 if (ch & UART_LSR_BI)
530 else if (ch & UART_LSR_PE)
532 else if (ch & UART_LSR_FE)
535 tty_insert_flip_char(tp->port, ch, flag);
538 tty_insert_flip_string(tp->port, ch_pos, s);
543 /* Flip queue if needed */
547 ch->ch_r_tail = tail & rmask;
548 ch->ch_e_tail = tail & rmask;
549 dgnc_check_queue_flow_control(ch);
550 spin_unlock_irqrestore(&ch->ch_lock, flags);
552 /* Tell the tty layer its okay to "eat" the data now */
553 tty_flip_buffer_push(tp->port);
560 spin_unlock_irqrestore(&ch->ch_lock, flags);
566 * Determines when CARRIER changes state and takes appropriate
569 void dgnc_carrier(struct channel_t *ch)
571 int virt_carrier = 0;
572 int phys_carrier = 0;
574 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
577 if (ch->ch_mistat & UART_MSR_DCD)
580 if (ch->ch_digi.digi_flags & DIGI_FORCEDCD)
583 if (ch->ch_c_cflag & CLOCAL)
586 /* Test for a VIRTUAL carrier transition to HIGH. */
588 if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
590 * When carrier rises, wake any threads waiting
591 * for carrier in the open routine.
593 if (waitqueue_active(&ch->ch_flags_wait))
594 wake_up_interruptible(&ch->ch_flags_wait);
597 /* Test for a PHYSICAL carrier transition to HIGH. */
599 if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
601 * When carrier rises, wake any threads waiting
602 * for carrier in the open routine.
604 if (waitqueue_active(&ch->ch_flags_wait))
605 wake_up_interruptible(&ch->ch_flags_wait);
609 * Test for a PHYSICAL transition to low, so long as we aren't
610 * currently ignoring physical transitions (which is what "virtual
611 * carrier" indicates).
613 * The transition of the virtual carrier to low really doesn't
614 * matter... it really only means "ignore carrier state", not
615 * "make pretend that carrier is there".
617 if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0) &&
618 (phys_carrier == 0)) {
620 * When carrier drops:
622 * Drop carrier on all open units.
624 * Flush queues, waking up any task waiting in the
627 * Send a hangup to the control terminal.
629 * Enable all select calls.
631 if (waitqueue_active(&ch->ch_flags_wait))
632 wake_up_interruptible(&ch->ch_flags_wait);
634 if (ch->ch_tun.un_open_count > 0)
635 tty_hangup(ch->ch_tun.un_tty);
637 if (ch->ch_pun.un_open_count > 0)
638 tty_hangup(ch->ch_pun.un_tty);
641 /* Make sure that our cached values reflect the current reality. */
643 if (virt_carrier == 1)
644 ch->ch_flags |= CH_FCAR;
646 ch->ch_flags &= ~CH_FCAR;
648 if (phys_carrier == 1)
649 ch->ch_flags |= CH_CD;
651 ch->ch_flags &= ~CH_CD;
654 /* Assign the custom baud rate to the channel structure */
656 static void dgnc_set_custom_speed(struct channel_t *ch, uint newrate)
665 ch->ch_custom_speed = 0;
670 * Since the divisor is stored in a 16-bit integer, we make sure
671 * we don't allow any rates smaller than a 16-bit integer would allow.
672 * And of course, rates above the dividend won't fly.
674 if (newrate && newrate < ((ch->ch_bd->bd_dividend / 0xFFFF) + 1))
675 newrate = (ch->ch_bd->bd_dividend / 0xFFFF) + 1;
677 if (newrate && newrate > ch->ch_bd->bd_dividend)
678 newrate = ch->ch_bd->bd_dividend;
681 testdiv = ch->ch_bd->bd_dividend / newrate;
684 * If we try to figure out what rate the board would use
685 * with the test divisor, it will be either equal or higher
686 * than the requested baud rate. If we then determine the
687 * rate with a divisor one higher, we will get the next lower
688 * supported rate below the requested.
690 testrate_high = ch->ch_bd->bd_dividend / testdiv;
691 testrate_low = ch->ch_bd->bd_dividend / (testdiv + 1);
694 * If the rate for the requested divisor is correct, just
695 * use it and be done.
697 if (testrate_high != newrate) {
699 * Otherwise, pick the rate that is closer
700 * (i.e. whichever rate has a smaller delta).
702 deltahigh = testrate_high - newrate;
703 deltalow = newrate - testrate_low;
705 if (deltahigh < deltalow)
706 newrate = testrate_high;
708 newrate = testrate_low;
712 ch->ch_custom_speed = newrate;
715 void dgnc_check_queue_flow_control(struct channel_t *ch)
719 /* Store how much space we have left in the queue */
720 qleft = ch->ch_r_tail - ch->ch_r_head - 1;
722 qleft += RQUEUEMASK + 1;
725 * Check to see if we should enforce flow control on our queue because
726 * the ld (or user) isn't reading data out of our queue fast enuf.
728 * NOTE: This is done based on what the current flow control of the
731 * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
732 * This will cause the UART's FIFO to back up, and force
733 * the RTS signal to be dropped.
734 * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
735 * the other side, in hopes it will stop sending data to us.
736 * 3) NONE - Nothing we can do. We will simply drop any extra data
737 * that gets sent into us when the queue fills up.
741 if (ch->ch_digi.digi_flags & CTSPACE ||
742 ch->ch_c_cflag & CRTSCTS) {
743 if (!(ch->ch_flags & CH_RECEIVER_OFF)) {
744 ch->ch_bd->bd_ops->disable_receiver(ch);
745 ch->ch_flags |= (CH_RECEIVER_OFF);
749 else if (ch->ch_c_iflag & IXOFF) {
750 if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
751 ch->ch_bd->bd_ops->send_stop_character(ch);
758 * Check to see if we should unenforce flow control because
759 * ld (or user) finally read enuf data out of our queue.
761 * NOTE: This is done based on what the current flow control of the
764 * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
765 * This will cause the UART's FIFO to raise RTS back up,
766 * which will allow the other side to start sending data again.
767 * 2) SWFLOW (IXOFF) - Send a start character to
768 * the other side, so it will start sending data to us again.
769 * 3) NONE - Do nothing. Since we didn't do anything to turn off the
770 * other side, we don't need to do anything now.
772 if (qleft > (RQUEUESIZE / 2)) {
774 if (ch->ch_digi.digi_flags & RTSPACE ||
775 ch->ch_c_cflag & CRTSCTS) {
776 if (ch->ch_flags & CH_RECEIVER_OFF) {
777 ch->ch_bd->bd_ops->enable_receiver(ch);
778 ch->ch_flags &= ~(CH_RECEIVER_OFF);
782 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
783 ch->ch_stops_sent = 0;
784 ch->ch_bd->bd_ops->send_start_character(ch);
789 static void dgnc_set_signal_low(struct channel_t *ch, const unsigned char sig)
791 ch->ch_mostat &= ~(sig);
792 ch->ch_bd->bd_ops->assert_modem_signals(ch);
795 void dgnc_wakeup_writes(struct channel_t *ch)
800 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
803 spin_lock_irqsave(&ch->ch_lock, flags);
805 /* If channel now has space, wake up anyone waiting on the condition. */
807 qlen = ch->ch_w_head - ch->ch_w_tail;
811 if (qlen >= (WQUEUESIZE - 256)) {
812 spin_unlock_irqrestore(&ch->ch_lock, flags);
816 if (ch->ch_tun.un_flags & UN_ISOPEN) {
817 tty_wakeup(ch->ch_tun.un_tty);
820 * If unit is set to wait until empty, check to make sure
821 * the queue AND FIFO are both empty.
823 if (ch->ch_tun.un_flags & UN_EMPTY) {
825 (ch->ch_bd->bd_ops->get_uart_bytes_left(ch) == 0)) {
826 ch->ch_tun.un_flags &= ~(UN_EMPTY);
829 * If RTS Toggle mode is on, whenever
830 * the queue and UART is empty, keep RTS low.
832 if (ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE)
833 dgnc_set_signal_low(ch, UART_MCR_RTS);
836 * If DTR Toggle mode is on, whenever
837 * the queue and UART is empty, keep DTR low.
839 if (ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE)
840 dgnc_set_signal_low(ch, UART_MCR_DTR);
844 wake_up_interruptible(&ch->ch_tun.un_flags_wait);
847 if (ch->ch_pun.un_flags & UN_ISOPEN) {
848 tty_wakeup(ch->ch_pun.un_tty);
851 * If unit is set to wait until empty, check to make sure
852 * the queue AND FIFO are both empty.
854 if (ch->ch_pun.un_flags & UN_EMPTY) {
856 (ch->ch_bd->bd_ops->get_uart_bytes_left(ch) == 0))
857 ch->ch_pun.un_flags &= ~(UN_EMPTY);
860 wake_up_interruptible(&ch->ch_pun.un_flags_wait);
863 spin_unlock_irqrestore(&ch->ch_lock, flags);
866 static struct dgnc_board *find_board_by_major(unsigned int major)
870 for (i = 0; i < MAXBOARDS; i++) {
871 struct dgnc_board *brd = dgnc_board[i];
876 if (major == brd->serial_driver->major ||
877 major == brd->print_driver->major)
884 /* TTY Entry points and helper functions */
886 /* dgnc_tty_open() */
888 static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
890 struct dgnc_board *brd;
891 struct channel_t *ch;
900 major = MAJOR(tty_devnum(tty));
901 minor = MINOR(tty_devnum(tty));
906 /* Get board pointer from our array of majors we have allocated */
907 brd = find_board_by_major(major);
912 * If board is not yet up to a state of READY, go to
913 * sleep waiting for it to happen or they cancel the open.
915 rc = wait_event_interruptible(brd->state_wait,
916 (brd->state & BOARD_READY));
920 spin_lock_irqsave(&brd->bd_lock, flags);
922 /* If opened device is greater than our number of ports, bail. */
923 if (PORT_NUM(minor) >= brd->nasync) {
928 ch = brd->channels[PORT_NUM(minor)];
934 /* Drop board lock */
935 spin_unlock_irqrestore(&brd->bd_lock, flags);
937 /* Grab channel lock */
938 spin_lock_irqsave(&ch->ch_lock, flags);
940 /* Figure out our type */
941 if (!IS_PRINT(minor)) {
942 un = &brd->channels[PORT_NUM(minor)]->ch_tun;
943 un->un_type = DGNC_SERIAL;
944 } else if (IS_PRINT(minor)) {
945 un = &brd->channels[PORT_NUM(minor)]->ch_pun;
946 un->un_type = DGNC_PRINT;
953 * If the port is still in a previous open, and in a state
954 * where we simply cannot safely keep going, wait until the
957 spin_unlock_irqrestore(&ch->ch_lock, flags);
959 rc = wait_event_interruptible(ch->ch_flags_wait,
960 ((ch->ch_flags & CH_OPENING) == 0));
961 /* If ret is non-zero, user ctrl-c'ed us */
966 * If either unit is in the middle of the fragile part of close,
967 * we just cannot touch the channel safely.
968 * Go to sleep, knowing that when the channel can be
969 * touched safely, the close routine will signal the
970 * ch_flags_wait to wake us back up.
972 rc = wait_event_interruptible(
974 (((ch->ch_tun.un_flags |
975 ch->ch_pun.un_flags) & UN_CLOSING) == 0));
976 /* If ret is non-zero, user ctrl-c'ed us */
980 spin_lock_irqsave(&ch->ch_lock, flags);
982 /* Store our unit into driver_data, so we always have it available. */
983 tty->driver_data = un;
985 /* Initialize tty's */
987 if (!(un->un_flags & UN_ISOPEN)) {
988 /* Store important variables. */
991 /* Maybe do something here to the TTY struct as well? */
995 * Allocate channel buffers for read/write/error.
996 * Set flag, so we don't get trounced on.
998 ch->ch_flags |= (CH_OPENING);
1000 /* Drop locks, as malloc with GFP_KERNEL can sleep */
1001 spin_unlock_irqrestore(&ch->ch_lock, flags);
1004 ch->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
1006 ch->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
1008 ch->ch_wqueue = kzalloc(WQUEUESIZE, GFP_KERNEL);
1010 if (!ch->ch_rqueue || !ch->ch_equeue || !ch->ch_wqueue) {
1011 kfree(ch->ch_rqueue);
1012 kfree(ch->ch_equeue);
1013 kfree(ch->ch_wqueue);
1017 spin_lock_irqsave(&ch->ch_lock, flags);
1019 ch->ch_flags &= ~(CH_OPENING);
1020 wake_up_interruptible(&ch->ch_flags_wait);
1022 /* Initialize if neither terminal or printer is open. */
1024 if (!((ch->ch_tun.un_flags | ch->ch_pun.un_flags) & UN_ISOPEN)) {
1025 /* Flush input queues. */
1033 brd->bd_ops->flush_uart_write(ch);
1034 brd->bd_ops->flush_uart_read(ch);
1037 ch->ch_cached_lsr = 0;
1038 ch->ch_stop_sending_break = 0;
1039 ch->ch_stops_sent = 0;
1041 ch->ch_c_cflag = tty->termios.c_cflag;
1042 ch->ch_c_iflag = tty->termios.c_iflag;
1043 ch->ch_c_oflag = tty->termios.c_oflag;
1044 ch->ch_c_lflag = tty->termios.c_lflag;
1045 ch->ch_startc = tty->termios.c_cc[VSTART];
1046 ch->ch_stopc = tty->termios.c_cc[VSTOP];
1049 * Bring up RTS and DTR...
1050 * Also handle RTS or DTR toggle if set.
1052 if (!(ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE))
1053 ch->ch_mostat |= (UART_MCR_RTS);
1054 if (!(ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE))
1055 ch->ch_mostat |= (UART_MCR_DTR);
1057 /* Tell UART to init itself */
1058 brd->bd_ops->uart_init(ch);
1061 /* Run param in case we changed anything */
1063 brd->bd_ops->param(tty);
1067 /* follow protocol for opening port */
1069 spin_unlock_irqrestore(&ch->ch_lock, flags);
1071 rc = dgnc_block_til_ready(tty, file, ch);
1073 /* No going back now, increment our unit and channel counters */
1074 spin_lock_irqsave(&ch->ch_lock, flags);
1075 ch->ch_open_count++;
1076 un->un_open_count++;
1077 un->un_flags |= (UN_ISOPEN);
1078 spin_unlock_irqrestore(&ch->ch_lock, flags);
1083 spin_unlock_irqrestore(&brd->bd_lock, flags);
1086 spin_unlock_irqrestore(&ch->ch_lock, flags);
1092 * dgnc_block_til_ready()
1094 * Wait for DCD, if needed.
1096 static int dgnc_block_til_ready(struct tty_struct *tty,
1098 struct channel_t *ch)
1101 struct un_t *un = tty->driver_data;
1102 unsigned long flags;
1104 int sleep_on_un_flags = 0;
1109 spin_lock_irqsave(&ch->ch_lock, flags);
1115 sleep_on_un_flags = 0;
1118 * If board has failed somehow during our sleep,
1121 if (ch->ch_bd->state == BOARD_FAILED) {
1126 /* If tty was hung up, break out of loop and set error. */
1127 if (tty_hung_up_p(file)) {
1133 * If either unit is in the middle of the fragile part of close,
1134 * we just cannot touch the channel safely.
1135 * Go back to sleep, knowing that when the channel can be
1136 * touched safely, the close routine will signal the
1137 * ch_wait_flags to wake us back up.
1139 if (!((ch->ch_tun.un_flags |
1140 ch->ch_pun.un_flags) &
1143 * Our conditions to leave cleanly and happily:
1144 * 1) NONBLOCKING on the tty is set.
1146 * 3) DCD (fake or real) is active.
1149 if (file->f_flags & O_NONBLOCK)
1152 if (tty_io_error(tty)) {
1157 if (ch->ch_flags & CH_CD)
1160 if (ch->ch_flags & CH_FCAR)
1163 sleep_on_un_flags = 1;
1167 * If there is a signal pending, the user probably
1168 * interrupted (ctrl-c) us.
1169 * Leave loop with error set.
1171 if (signal_pending(current)) {
1176 /* Store the flags before we let go of channel lock */
1178 if (sleep_on_un_flags)
1179 old_flags = ch->ch_tun.un_flags | ch->ch_pun.un_flags;
1181 old_flags = ch->ch_flags;
1184 * Let go of channel lock before calling schedule.
1185 * Our poller will get any FEP events and wake us up when DCD
1186 * eventually goes active.
1189 spin_unlock_irqrestore(&ch->ch_lock, flags);
1192 * Wait for something in the flags to change
1193 * from the current value.
1195 if (sleep_on_un_flags)
1196 rc = wait_event_interruptible
1198 (old_flags != (ch->ch_tun.un_flags |
1199 ch->ch_pun.un_flags)));
1201 rc = wait_event_interruptible(
1203 (old_flags != ch->ch_flags));
1206 * We got woken up for some reason.
1207 * Before looping around, grab our channel lock.
1209 spin_lock_irqsave(&ch->ch_lock, flags);
1214 spin_unlock_irqrestore(&ch->ch_lock, flags);
1221 * Hangup the port. Like a close, but don't wait for output to drain.
1223 static void dgnc_tty_hangup(struct tty_struct *tty)
1225 if (!tty || tty->magic != TTY_MAGIC)
1228 /* flush the transmit queues */
1229 dgnc_tty_flush_buffer(tty);
1232 /* dgnc_tty_close() */
1234 static void dgnc_tty_close(struct tty_struct *tty, struct file *file)
1236 struct dgnc_board *bd;
1237 struct channel_t *ch;
1239 unsigned long flags;
1241 if (!tty || tty->magic != TTY_MAGIC)
1244 un = tty->driver_data;
1245 if (!un || un->magic != DGNC_UNIT_MAGIC)
1249 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1253 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
1256 spin_lock_irqsave(&ch->ch_lock, flags);
1259 * Determine if this is the last close or not - and if we agree about
1260 * which type of close it is with the Line Discipline
1262 if ((tty->count == 1) && (un->un_open_count != 1)) {
1264 * Uh, oh. tty->count is 1, which means that the tty
1265 * structure will be freed. un_open_count should always
1266 * be one in these conditions. If it's greater than
1267 * one, we've got real problems, since it means the
1268 * serial port won't be shutdown.
1271 "tty->count is 1, un open count is %d\n",
1273 un->un_open_count = 1;
1276 if (un->un_open_count)
1277 un->un_open_count--;
1280 "bad serial port open count of %d\n",
1283 ch->ch_open_count--;
1285 if (ch->ch_open_count && un->un_open_count) {
1286 spin_unlock_irqrestore(&ch->ch_lock, flags);
1290 /* OK, its the last close on the unit */
1291 un->un_flags |= UN_CLOSING;
1296 * Only officially close channel if count is 0 and
1297 * DIGI_PRINTER bit is not set.
1299 if ((ch->ch_open_count == 0) &&
1300 !(ch->ch_digi.digi_flags & DIGI_PRINTER)) {
1301 ch->ch_flags &= ~(CH_STOPI | CH_FORCED_STOPI);
1303 /* turn off print device when closing print device. */
1305 if ((un->un_type == DGNC_PRINT) && (ch->ch_flags & CH_PRON)) {
1306 dgnc_wmove(ch, ch->ch_digi.digi_offstr,
1307 (int)ch->ch_digi.digi_offlen);
1308 ch->ch_flags &= ~CH_PRON;
1311 spin_unlock_irqrestore(&ch->ch_lock, flags);
1312 /* wait for output to drain */
1313 /* This will also return if we take an interrupt */
1315 bd->bd_ops->drain(tty, 0);
1317 dgnc_tty_flush_buffer(tty);
1318 tty_ldisc_flush(tty);
1320 spin_lock_irqsave(&ch->ch_lock, flags);
1324 /* If we have HUPCL set, lower DTR and RTS */
1326 if (ch->ch_c_cflag & HUPCL) {
1328 ch->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
1329 bd->bd_ops->assert_modem_signals(ch);
1332 * Go to sleep to ensure RTS/DTR
1333 * have been dropped for modems to see it.
1335 if (ch->ch_close_delay) {
1336 spin_unlock_irqrestore(&ch->ch_lock,
1338 dgnc_ms_sleep(ch->ch_close_delay);
1339 spin_lock_irqsave(&ch->ch_lock, flags);
1343 ch->ch_old_baud = 0;
1345 /* Turn off UART interrupts for this port */
1346 ch->ch_bd->bd_ops->uart_off(ch);
1348 /* turn off print device when closing print device. */
1350 if ((un->un_type == DGNC_PRINT) && (ch->ch_flags & CH_PRON)) {
1351 dgnc_wmove(ch, ch->ch_digi.digi_offstr,
1352 (int)ch->ch_digi.digi_offlen);
1353 ch->ch_flags &= ~CH_PRON;
1358 un->un_flags &= ~(UN_ISOPEN | UN_CLOSING);
1360 wake_up_interruptible(&ch->ch_flags_wait);
1361 wake_up_interruptible(&un->un_flags_wait);
1363 spin_unlock_irqrestore(&ch->ch_lock, flags);
1367 * dgnc_tty_chars_in_buffer()
1369 * Return number of characters that have not been transmitted yet.
1371 * This routine is used by the line discipline to determine if there
1372 * is data waiting to be transmitted/drained/flushed or not.
1374 static int dgnc_tty_chars_in_buffer(struct tty_struct *tty)
1376 struct channel_t *ch = NULL;
1377 struct un_t *un = NULL;
1382 unsigned long flags;
1387 un = tty->driver_data;
1388 if (!un || un->magic != DGNC_UNIT_MAGIC)
1392 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1395 spin_lock_irqsave(&ch->ch_lock, flags);
1398 thead = ch->ch_w_head & tmask;
1399 ttail = ch->ch_w_tail & tmask;
1401 spin_unlock_irqrestore(&ch->ch_lock, flags);
1405 else if (thead > ttail)
1406 chars = thead - ttail;
1408 chars = thead - ttail + WQUEUESIZE;
1416 * Reduces bytes_available to the max number of characters
1417 * that can be sent currently given the maxcps value, and
1418 * returns the new bytes_available. This only affects printer
1421 static int dgnc_maxcps_room(struct channel_t *ch, int bytes_available)
1423 int rc = bytes_available;
1425 if (ch->ch_digi.digi_maxcps > 0 && ch->ch_digi.digi_bufsize > 0) {
1427 unsigned long current_time = jiffies;
1428 unsigned long buffer_time = current_time +
1429 (HZ * ch->ch_digi.digi_bufsize) /
1430 ch->ch_digi.digi_maxcps;
1432 if (ch->ch_cpstime < current_time) {
1433 /* buffer is empty */
1434 ch->ch_cpstime = current_time; /* reset ch_cpstime */
1435 cps_limit = ch->ch_digi.digi_bufsize;
1436 } else if (ch->ch_cpstime < buffer_time) {
1437 /* still room in the buffer */
1438 cps_limit = ((buffer_time - ch->ch_cpstime) *
1439 ch->ch_digi.digi_maxcps) / HZ;
1441 /* no room in the buffer */
1445 rc = min(cps_limit, bytes_available);
1452 * dgnc_tty_write_room()
1454 * Return room available in Tx buffer
1456 static int dgnc_tty_write_room(struct tty_struct *tty)
1458 struct channel_t *ch = NULL;
1459 struct un_t *un = NULL;
1464 unsigned long flags;
1469 un = tty->driver_data;
1470 if (!un || un->magic != DGNC_UNIT_MAGIC)
1474 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1477 spin_lock_irqsave(&ch->ch_lock, flags);
1480 head = (ch->ch_w_head) & tmask;
1481 tail = (ch->ch_w_tail) & tmask;
1483 room = tail - head - 1;
1487 /* Limit printer to maxcps */
1488 if (un->un_type != DGNC_PRINT)
1489 room = dgnc_maxcps_room(ch, room);
1492 * If we are printer device, leave room for
1493 * possibly both the on and off strings.
1495 if (un->un_type == DGNC_PRINT) {
1496 if (!(ch->ch_flags & CH_PRON))
1497 room -= ch->ch_digi.digi_onlen;
1498 room -= ch->ch_digi.digi_offlen;
1500 if (ch->ch_flags & CH_PRON)
1501 room -= ch->ch_digi.digi_offlen;
1507 spin_unlock_irqrestore(&ch->ch_lock, flags);
1512 * dgnc_tty_put_char()
1514 * Put a character into ch->ch_buf
1516 * - used by the line discipline for OPOST processing
1518 static int dgnc_tty_put_char(struct tty_struct *tty, unsigned char c)
1520 /* Simply call tty_write. */
1522 dgnc_tty_write(tty, &c, 1);
1529 * Take data from the user or kernel and send it out to the FEP.
1530 * In here exists all the Transparent Print magic as well.
1532 static int dgnc_tty_write(struct tty_struct *tty,
1533 const unsigned char *buf, int count)
1535 struct channel_t *ch = NULL;
1536 struct un_t *un = NULL;
1537 int bufcount = 0, n = 0;
1538 unsigned long flags;
1547 un = tty->driver_data;
1548 if (!un || un->magic != DGNC_UNIT_MAGIC)
1552 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1559 * Store original amount of characters passed in.
1560 * This helps to figure out if we should ask the FEP
1561 * to send us an event when it has more space available.
1564 spin_lock_irqsave(&ch->ch_lock, flags);
1566 /* Get our space available for the channel from the board */
1568 head = (ch->ch_w_head) & tmask;
1569 tail = (ch->ch_w_tail) & tmask;
1571 bufcount = tail - head - 1;
1573 bufcount += WQUEUESIZE;
1576 * Limit printer output to maxcps overall, with bursts allowed
1577 * up to bufsize characters.
1579 if (un->un_type != DGNC_PRINT)
1580 bufcount = dgnc_maxcps_room(ch, bufcount);
1583 * Take minimum of what the user wants to send, and the
1584 * space available in the FEP buffer.
1586 count = min(count, bufcount);
1588 /* Bail if no space left. */
1594 * Output the printer ON string, if we are in terminal mode, but
1595 * need to be in printer mode.
1597 if ((un->un_type == DGNC_PRINT) && !(ch->ch_flags & CH_PRON)) {
1598 dgnc_wmove(ch, ch->ch_digi.digi_onstr,
1599 (int)ch->ch_digi.digi_onlen);
1600 head = (ch->ch_w_head) & tmask;
1601 ch->ch_flags |= CH_PRON;
1605 * On the other hand, output the printer OFF string, if we are
1606 * currently in printer mode, but need to output to the terminal.
1608 if ((un->un_type != DGNC_PRINT) && (ch->ch_flags & CH_PRON)) {
1609 dgnc_wmove(ch, ch->ch_digi.digi_offstr,
1610 (int)ch->ch_digi.digi_offlen);
1611 head = (ch->ch_w_head) & tmask;
1612 ch->ch_flags &= ~CH_PRON;
1618 * If the write wraps over the top of the circular buffer,
1619 * move the portion up to the wrap point, and reset the
1620 * pointers to the bottom.
1622 remain = WQUEUESIZE - head;
1626 memcpy(ch->ch_wqueue + head, buf, remain);
1632 /* Move rest of data. */
1634 memcpy(ch->ch_wqueue + head, buf, remain);
1640 ch->ch_w_head = head;
1643 /* Update printer buffer empty time. */
1644 if ((un->un_type == DGNC_PRINT) && (ch->ch_digi.digi_maxcps > 0) &&
1645 (ch->ch_digi.digi_bufsize > 0)) {
1646 ch->ch_cpstime += (HZ * count) / ch->ch_digi.digi_maxcps;
1649 spin_unlock_irqrestore(&ch->ch_lock, flags);
1653 * Channel lock is grabbed and then released
1654 * inside this routine.
1656 ch->ch_bd->bd_ops->copy_data_from_queue_to_uart(ch);
1662 spin_unlock_irqrestore(&ch->ch_lock, flags);
1666 /* Return modem signals to ld. */
1668 static int dgnc_tty_tiocmget(struct tty_struct *tty)
1670 struct channel_t *ch;
1673 unsigned char mstat = 0;
1674 unsigned long flags;
1676 if (!tty || tty->magic != TTY_MAGIC)
1679 un = tty->driver_data;
1680 if (!un || un->magic != DGNC_UNIT_MAGIC)
1684 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1687 spin_lock_irqsave(&ch->ch_lock, flags);
1689 mstat = ch->ch_mostat | ch->ch_mistat;
1691 spin_unlock_irqrestore(&ch->ch_lock, flags);
1695 if (mstat & UART_MCR_DTR)
1697 if (mstat & UART_MCR_RTS)
1699 if (mstat & UART_MSR_CTS)
1701 if (mstat & UART_MSR_DSR)
1703 if (mstat & UART_MSR_RI)
1705 if (mstat & UART_MSR_DCD)
1712 * dgnc_tty_tiocmset()
1714 * Set modem signals, called by ld.
1717 static int dgnc_tty_tiocmset(struct tty_struct *tty,
1718 unsigned int set, unsigned int clear)
1720 struct dgnc_board *bd;
1721 struct channel_t *ch;
1724 unsigned long flags;
1726 if (!tty || tty->magic != TTY_MAGIC)
1729 un = tty->driver_data;
1730 if (!un || un->magic != DGNC_UNIT_MAGIC)
1734 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1738 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
1741 spin_lock_irqsave(&ch->ch_lock, flags);
1743 if (set & TIOCM_RTS)
1744 ch->ch_mostat |= UART_MCR_RTS;
1746 if (set & TIOCM_DTR)
1747 ch->ch_mostat |= UART_MCR_DTR;
1749 if (clear & TIOCM_RTS)
1750 ch->ch_mostat &= ~(UART_MCR_RTS);
1752 if (clear & TIOCM_DTR)
1753 ch->ch_mostat &= ~(UART_MCR_DTR);
1755 ch->ch_bd->bd_ops->assert_modem_signals(ch);
1757 spin_unlock_irqrestore(&ch->ch_lock, flags);
1763 * dgnc_tty_send_break()
1765 * Send a Break, called by ld.
1767 static int dgnc_tty_send_break(struct tty_struct *tty, int msec)
1769 struct dgnc_board *bd;
1770 struct channel_t *ch;
1773 unsigned long flags;
1775 if (!tty || tty->magic != TTY_MAGIC)
1778 un = tty->driver_data;
1779 if (!un || un->magic != DGNC_UNIT_MAGIC)
1783 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1787 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
1801 spin_lock_irqsave(&ch->ch_lock, flags);
1803 ch->ch_bd->bd_ops->send_break(ch, msec);
1805 spin_unlock_irqrestore(&ch->ch_lock, flags);
1811 * dgnc_tty_wait_until_sent()
1813 * wait until data has been transmitted, called by ld.
1815 static void dgnc_tty_wait_until_sent(struct tty_struct *tty, int timeout)
1817 struct dgnc_board *bd;
1818 struct channel_t *ch;
1821 if (!tty || tty->magic != TTY_MAGIC)
1824 un = tty->driver_data;
1825 if (!un || un->magic != DGNC_UNIT_MAGIC)
1829 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1833 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
1836 bd->bd_ops->drain(tty, 0);
1842 * send a high priority character, called by ld.
1844 static void dgnc_tty_send_xchar(struct tty_struct *tty, char c)
1846 struct dgnc_board *bd;
1847 struct channel_t *ch;
1849 unsigned long flags;
1851 if (!tty || tty->magic != TTY_MAGIC)
1854 un = tty->driver_data;
1855 if (!un || un->magic != DGNC_UNIT_MAGIC)
1859 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1863 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
1866 dev_dbg(tty->dev, "dgnc_tty_send_xchar start\n");
1868 spin_lock_irqsave(&ch->ch_lock, flags);
1869 bd->bd_ops->send_immediate_char(ch, c);
1870 spin_unlock_irqrestore(&ch->ch_lock, flags);
1872 dev_dbg(tty->dev, "dgnc_tty_send_xchar finish\n");
1875 /* Return modem signals to ld. */
1877 static inline int dgnc_get_mstat(struct channel_t *ch)
1879 unsigned char mstat;
1881 unsigned long flags;
1883 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1886 spin_lock_irqsave(&ch->ch_lock, flags);
1888 mstat = ch->ch_mostat | ch->ch_mistat;
1890 spin_unlock_irqrestore(&ch->ch_lock, flags);
1894 if (mstat & UART_MCR_DTR)
1896 if (mstat & UART_MCR_RTS)
1898 if (mstat & UART_MSR_CTS)
1900 if (mstat & UART_MSR_DSR)
1902 if (mstat & UART_MSR_RI)
1904 if (mstat & UART_MSR_DCD)
1910 /* Return modem signals to ld. */
1912 static int dgnc_get_modem_info(struct channel_t *ch,
1913 unsigned int __user *value)
1915 return put_user(dgnc_get_mstat(ch), value);
1919 * dgnc_set_modem_info()
1921 * Set modem signals, called by ld.
1923 static int dgnc_set_modem_info(struct channel_t *ch,
1924 unsigned int command,
1925 unsigned int __user *value)
1928 unsigned int arg = 0;
1929 unsigned long flags;
1931 rc = get_user(arg, value);
1937 if (arg & TIOCM_RTS)
1938 ch->ch_mostat |= UART_MCR_RTS;
1940 if (arg & TIOCM_DTR)
1941 ch->ch_mostat |= UART_MCR_DTR;
1946 if (arg & TIOCM_RTS)
1947 ch->ch_mostat &= ~(UART_MCR_RTS);
1949 if (arg & TIOCM_DTR)
1950 ch->ch_mostat &= ~(UART_MCR_DTR);
1956 if (arg & TIOCM_RTS)
1957 ch->ch_mostat |= UART_MCR_RTS;
1959 ch->ch_mostat &= ~(UART_MCR_RTS);
1961 if (arg & TIOCM_DTR)
1962 ch->ch_mostat |= UART_MCR_DTR;
1964 ch->ch_mostat &= ~(UART_MCR_DTR);
1972 spin_lock_irqsave(&ch->ch_lock, flags);
1974 ch->ch_bd->bd_ops->assert_modem_signals(ch);
1976 spin_unlock_irqrestore(&ch->ch_lock, flags);
1982 * dgnc_tty_digigeta()
1984 * Ioctl to get the information for ditty.
1986 static int dgnc_tty_digigeta(struct tty_struct *tty,
1987 struct digi_t __user *retinfo)
1989 struct channel_t *ch;
1992 unsigned long flags;
1998 if (!tty || tty->magic != TTY_MAGIC)
2001 un = tty->driver_data;
2002 if (!un || un->magic != DGNC_UNIT_MAGIC)
2006 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2009 memset(&tmp, 0, sizeof(tmp));
2011 spin_lock_irqsave(&ch->ch_lock, flags);
2012 memcpy(&tmp, &ch->ch_digi, sizeof(tmp));
2013 spin_unlock_irqrestore(&ch->ch_lock, flags);
2015 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
2022 * dgnc_tty_digiseta()
2024 * Ioctl to set the information for ditty.
2026 static int dgnc_tty_digiseta(struct tty_struct *tty,
2027 struct digi_t __user *new_info)
2029 struct dgnc_board *bd;
2030 struct channel_t *ch;
2032 struct digi_t new_digi;
2033 unsigned long flags;
2036 if (!tty || tty->magic != TTY_MAGIC)
2039 un = tty->driver_data;
2040 if (!un || un->magic != DGNC_UNIT_MAGIC)
2044 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2048 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
2051 if (copy_from_user(&new_digi, new_info, sizeof(new_digi)))
2054 spin_lock_irqsave(&ch->ch_lock, flags);
2056 /* Handle transitions to and from RTS Toggle. */
2058 if (!(ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) &&
2059 (new_digi.digi_flags & DIGI_RTS_TOGGLE))
2060 ch->ch_mostat &= ~(UART_MCR_RTS);
2061 if ((ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) &&
2062 !(new_digi.digi_flags & DIGI_RTS_TOGGLE))
2063 ch->ch_mostat |= (UART_MCR_RTS);
2065 /* Handle transitions to and from DTR Toggle. */
2067 if (!(ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) &&
2068 (new_digi.digi_flags & DIGI_DTR_TOGGLE))
2069 ch->ch_mostat &= ~(UART_MCR_DTR);
2070 if ((ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) &&
2071 !(new_digi.digi_flags & DIGI_DTR_TOGGLE))
2072 ch->ch_mostat |= (UART_MCR_DTR);
2074 memcpy(&ch->ch_digi, &new_digi, sizeof(new_digi));
2076 if (ch->ch_digi.digi_maxcps < 1)
2077 ch->ch_digi.digi_maxcps = 1;
2079 if (ch->ch_digi.digi_maxcps > 10000)
2080 ch->ch_digi.digi_maxcps = 10000;
2082 if (ch->ch_digi.digi_bufsize < 10)
2083 ch->ch_digi.digi_bufsize = 10;
2085 if (ch->ch_digi.digi_maxchar < 1)
2086 ch->ch_digi.digi_maxchar = 1;
2088 if (ch->ch_digi.digi_maxchar > ch->ch_digi.digi_bufsize)
2089 ch->ch_digi.digi_maxchar = ch->ch_digi.digi_bufsize;
2091 if (ch->ch_digi.digi_onlen > DIGI_PLEN)
2092 ch->ch_digi.digi_onlen = DIGI_PLEN;
2094 if (ch->ch_digi.digi_offlen > DIGI_PLEN)
2095 ch->ch_digi.digi_offlen = DIGI_PLEN;
2097 ch->ch_bd->bd_ops->param(tty);
2099 spin_unlock_irqrestore(&ch->ch_lock, flags);
2104 /* dgnc_set_termios() */
2106 static void dgnc_tty_set_termios(struct tty_struct *tty,
2107 struct ktermios *old_termios)
2109 struct dgnc_board *bd;
2110 struct channel_t *ch;
2112 unsigned long flags;
2114 if (!tty || tty->magic != TTY_MAGIC)
2117 un = tty->driver_data;
2118 if (!un || un->magic != DGNC_UNIT_MAGIC)
2122 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2126 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
2129 spin_lock_irqsave(&ch->ch_lock, flags);
2131 ch->ch_c_cflag = tty->termios.c_cflag;
2132 ch->ch_c_iflag = tty->termios.c_iflag;
2133 ch->ch_c_oflag = tty->termios.c_oflag;
2134 ch->ch_c_lflag = tty->termios.c_lflag;
2135 ch->ch_startc = tty->termios.c_cc[VSTART];
2136 ch->ch_stopc = tty->termios.c_cc[VSTOP];
2138 ch->ch_bd->bd_ops->param(tty);
2141 spin_unlock_irqrestore(&ch->ch_lock, flags);
2144 static void dgnc_tty_throttle(struct tty_struct *tty)
2146 struct channel_t *ch;
2148 unsigned long flags;
2150 if (!tty || tty->magic != TTY_MAGIC)
2153 un = tty->driver_data;
2154 if (!un || un->magic != DGNC_UNIT_MAGIC)
2158 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2161 spin_lock_irqsave(&ch->ch_lock, flags);
2163 ch->ch_flags |= (CH_FORCED_STOPI);
2165 spin_unlock_irqrestore(&ch->ch_lock, flags);
2168 static void dgnc_tty_unthrottle(struct tty_struct *tty)
2170 struct channel_t *ch;
2172 unsigned long flags;
2174 if (!tty || tty->magic != TTY_MAGIC)
2177 un = tty->driver_data;
2178 if (!un || un->magic != DGNC_UNIT_MAGIC)
2182 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2185 spin_lock_irqsave(&ch->ch_lock, flags);
2187 ch->ch_flags &= ~(CH_FORCED_STOPI);
2189 spin_unlock_irqrestore(&ch->ch_lock, flags);
2192 static void dgnc_tty_start(struct tty_struct *tty)
2194 struct dgnc_board *bd;
2195 struct channel_t *ch;
2197 unsigned long flags;
2199 if (!tty || tty->magic != TTY_MAGIC)
2202 un = tty->driver_data;
2203 if (!un || un->magic != DGNC_UNIT_MAGIC)
2207 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2211 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
2214 spin_lock_irqsave(&ch->ch_lock, flags);
2216 ch->ch_flags &= ~(CH_FORCED_STOP);
2218 spin_unlock_irqrestore(&ch->ch_lock, flags);
2221 static void dgnc_tty_stop(struct tty_struct *tty)
2223 struct dgnc_board *bd;
2224 struct channel_t *ch;
2226 unsigned long flags;
2228 if (!tty || tty->magic != TTY_MAGIC)
2231 un = tty->driver_data;
2232 if (!un || un->magic != DGNC_UNIT_MAGIC)
2236 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2240 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
2243 spin_lock_irqsave(&ch->ch_lock, flags);
2245 ch->ch_flags |= (CH_FORCED_STOP);
2247 spin_unlock_irqrestore(&ch->ch_lock, flags);
2251 * dgnc_tty_flush_chars()
2253 * Flush the cook buffer
2255 * Note to self, and any other poor souls who venture here:
2257 * flush in this case DOES NOT mean dispose of the data.
2258 * instead, it means "stop buffering and send it if you
2259 * haven't already." Just guess how I figured that out... SRW 2-Jun-98
2261 * It is also always called in interrupt context - JAR 8-Sept-99
2263 static void dgnc_tty_flush_chars(struct tty_struct *tty)
2265 struct dgnc_board *bd;
2266 struct channel_t *ch;
2268 unsigned long flags;
2270 if (!tty || tty->magic != TTY_MAGIC)
2273 un = tty->driver_data;
2274 if (!un || un->magic != DGNC_UNIT_MAGIC)
2278 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2282 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
2285 spin_lock_irqsave(&ch->ch_lock, flags);
2287 /* Do something maybe here */
2289 spin_unlock_irqrestore(&ch->ch_lock, flags);
2293 * dgnc_tty_flush_buffer()
2295 * Flush Tx buffer (make in == out)
2297 static void dgnc_tty_flush_buffer(struct tty_struct *tty)
2299 struct channel_t *ch;
2301 unsigned long flags;
2303 if (!tty || tty->magic != TTY_MAGIC)
2306 un = tty->driver_data;
2307 if (!un || un->magic != DGNC_UNIT_MAGIC)
2311 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2314 spin_lock_irqsave(&ch->ch_lock, flags);
2316 ch->ch_flags &= ~CH_STOP;
2318 /* Flush our write queue */
2319 ch->ch_w_head = ch->ch_w_tail;
2321 /* Flush UARTs transmit FIFO */
2322 ch->ch_bd->bd_ops->flush_uart_write(ch);
2324 if (ch->ch_tun.un_flags & (UN_LOW | UN_EMPTY)) {
2325 ch->ch_tun.un_flags &= ~(UN_LOW | UN_EMPTY);
2326 wake_up_interruptible(&ch->ch_tun.un_flags_wait);
2328 if (ch->ch_pun.un_flags & (UN_LOW | UN_EMPTY)) {
2329 ch->ch_pun.un_flags &= ~(UN_LOW | UN_EMPTY);
2330 wake_up_interruptible(&ch->ch_pun.un_flags_wait);
2333 spin_unlock_irqrestore(&ch->ch_lock, flags);
2337 * dgnc_wake_up_unit()
2339 * Wakes up processes waiting in the unit's (teminal/printer) wait queue
2341 static void dgnc_wake_up_unit(struct un_t *unit)
2343 unit->un_flags &= ~(UN_LOW | UN_EMPTY);
2344 wake_up_interruptible(&unit->un_flags_wait);
2347 /* The IOCTL function and all of its helpers */
2352 * The usual assortment of ioctl's
2354 static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
2357 struct dgnc_board *bd;
2358 struct board_ops *ch_bd_ops;
2359 struct channel_t *ch;
2362 unsigned long flags;
2363 void __user *uarg = (void __user *)arg;
2365 if (!tty || tty->magic != TTY_MAGIC)
2368 un = tty->driver_data;
2369 if (!un || un->magic != DGNC_UNIT_MAGIC)
2373 if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
2377 if (!bd || bd->magic != DGNC_BOARD_MAGIC)
2380 ch_bd_ops = bd->bd_ops;
2382 spin_lock_irqsave(&ch->ch_lock, flags);
2384 if (un->un_open_count <= 0) {
2390 /* Here are all the standard ioctl's that we MUST implement */
2394 * TCSBRK is SVID version: non-zero arg --> no break
2395 * this behaviour is exploited by tcdrain().
2397 * According to POSIX.1 spec (7.2.2.1.2) breaks should be
2398 * between 0.25 and 0.5 seconds so we'll ask for something
2399 * in the middle: 0.375 seconds.
2401 rc = tty_check_change(tty);
2402 spin_unlock_irqrestore(&ch->ch_lock, flags);
2406 rc = ch_bd_ops->drain(tty, 0);
2411 spin_lock_irqsave(&ch->ch_lock, flags);
2413 if (((cmd == TCSBRK) && (!arg)) || (cmd == TCSBRKP))
2414 ch_bd_ops->send_break(ch, 250);
2416 spin_unlock_irqrestore(&ch->ch_lock, flags);
2422 * support for POSIX tcsendbreak()
2423 * According to POSIX.1 spec (7.2.2.1.2) breaks should be
2424 * between 0.25 and 0.5 seconds so we'll ask for something
2425 * in the middle: 0.375 seconds.
2427 rc = tty_check_change(tty);
2428 spin_unlock_irqrestore(&ch->ch_lock, flags);
2432 rc = ch_bd_ops->drain(tty, 0);
2436 spin_lock_irqsave(&ch->ch_lock, flags);
2438 ch_bd_ops->send_break(ch, 250);
2440 spin_unlock_irqrestore(&ch->ch_lock, flags);
2445 rc = tty_check_change(tty);
2446 spin_unlock_irqrestore(&ch->ch_lock, flags);
2450 rc = ch_bd_ops->drain(tty, 0);
2454 spin_lock_irqsave(&ch->ch_lock, flags);
2456 ch_bd_ops->send_break(ch, 250);
2458 spin_unlock_irqrestore(&ch->ch_lock, flags);
2464 spin_unlock_irqrestore(&ch->ch_lock, flags);
2469 spin_unlock_irqrestore(&ch->ch_lock, flags);
2471 return put_user(C_CLOCAL(tty) ? 1 : 0,
2472 (unsigned long __user *)arg);
2476 spin_unlock_irqrestore(&ch->ch_lock, flags);
2477 rc = get_user(arg, (unsigned long __user *)arg);
2481 spin_lock_irqsave(&ch->ch_lock, flags);
2482 tty->termios.c_cflag = ((tty->termios.c_cflag & ~CLOCAL) |
2483 (arg ? CLOCAL : 0));
2484 ch_bd_ops->param(tty);
2485 spin_unlock_irqrestore(&ch->ch_lock, flags);
2490 spin_unlock_irqrestore(&ch->ch_lock, flags);
2491 return dgnc_get_modem_info(ch, uarg);
2496 spin_unlock_irqrestore(&ch->ch_lock, flags);
2497 return dgnc_set_modem_info(ch, cmd, uarg);
2499 /* Here are any additional ioctl's that we want to implement */
2503 * The linux tty driver doesn't have a flush
2504 * input routine for the driver, assuming all backed
2505 * up data is in the line disc. buffers. However,
2506 * we all know that's not the case. Here, we
2507 * act on the ioctl, but then lie and say we didn't
2508 * so the line discipline will process the flush
2511 rc = tty_check_change(tty);
2515 if ((arg == TCIFLUSH) || (arg == TCIOFLUSH)) {
2516 ch->ch_r_head = ch->ch_r_tail;
2517 ch_bd_ops->flush_uart_read(ch);
2518 /* Force queue flow control to be released, if needed */
2519 dgnc_check_queue_flow_control(ch);
2522 if ((arg == TCOFLUSH) || (arg == TCIOFLUSH)) {
2523 if (!(un->un_type == DGNC_PRINT)) {
2524 ch->ch_w_head = ch->ch_w_tail;
2525 ch_bd_ops->flush_uart_write(ch);
2527 if (ch->ch_tun.un_flags & (UN_LOW | UN_EMPTY))
2528 dgnc_wake_up_unit(&ch->ch_tun);
2530 if (ch->ch_pun.un_flags & (UN_LOW | UN_EMPTY))
2531 dgnc_wake_up_unit(&ch->ch_pun);
2535 /* pretend we didn't recognize this IOCTL */
2536 spin_unlock_irqrestore(&ch->ch_lock, flags);
2537 return -ENOIOCTLCMD;
2541 * The linux tty driver doesn't have a flush
2542 * input routine for the driver, assuming all backed
2543 * up data is in the line disc. buffers. However,
2544 * we all know that's not the case. Here, we
2545 * act on the ioctl, but then lie and say we didn't
2546 * so the line discipline will process the flush
2549 if (cmd == TCSETSF) {
2551 ch->ch_flags &= ~CH_STOP;
2552 ch->ch_r_head = ch->ch_r_tail;
2553 ch_bd_ops->flush_uart_read(ch);
2554 /* Force queue flow control to be released, if needed */
2555 dgnc_check_queue_flow_control(ch);
2558 /* now wait for all the output to drain */
2559 spin_unlock_irqrestore(&ch->ch_lock, flags);
2560 rc = ch_bd_ops->drain(tty, 0);
2564 /* pretend we didn't recognize this */
2565 return -ENOIOCTLCMD;
2569 spin_unlock_irqrestore(&ch->ch_lock, flags);
2570 rc = ch_bd_ops->drain(tty, 0);
2574 /* pretend we didn't recognize this */
2575 return -ENOIOCTLCMD;
2578 spin_unlock_irqrestore(&ch->ch_lock, flags);
2579 /* Make the ld do it */
2580 return -ENOIOCTLCMD;
2583 /* get information for ditty */
2584 spin_unlock_irqrestore(&ch->ch_lock, flags);
2585 return dgnc_tty_digigeta(tty, uarg);
2590 /* set information for ditty */
2591 if (cmd == (DIGI_SETAW)) {
2592 spin_unlock_irqrestore(&ch->ch_lock, flags);
2593 rc = ch_bd_ops->drain(tty, 0);
2597 spin_lock_irqsave(&ch->ch_lock, flags);
2599 tty_ldisc_flush(tty);
2604 spin_unlock_irqrestore(&ch->ch_lock, flags);
2605 return dgnc_tty_digiseta(tty, uarg);
2611 * Let go of locks when accessing user space,
2614 spin_unlock_irqrestore(&ch->ch_lock, flags);
2615 rc = get_user(loopback, (unsigned int __user *)arg);
2618 spin_lock_irqsave(&ch->ch_lock, flags);
2620 /* Enable/disable internal loopback for this port */
2622 ch->ch_flags |= CH_LOOPBACK;
2624 ch->ch_flags &= ~(CH_LOOPBACK);
2626 ch_bd_ops->param(tty);
2627 spin_unlock_irqrestore(&ch->ch_lock, flags);
2631 case DIGI_GETCUSTOMBAUD:
2632 spin_unlock_irqrestore(&ch->ch_lock, flags);
2633 return put_user(ch->ch_custom_speed,
2634 (unsigned int __user *)arg);
2636 case DIGI_SETCUSTOMBAUD:
2639 /* Let go of locks when accessing user space, could sleep */
2640 spin_unlock_irqrestore(&ch->ch_lock, flags);
2641 rc = get_user(new_rate, (int __user *)arg);
2644 spin_lock_irqsave(&ch->ch_lock, flags);
2645 dgnc_set_custom_speed(ch, new_rate);
2646 ch_bd_ops->param(tty);
2647 spin_unlock_irqrestore(&ch->ch_lock, flags);
2652 * This ioctl allows insertion of a character into the front
2653 * of any pending data to be transmitted.
2655 * This ioctl is to satisfy the "Send Character Immediate"
2656 * call that the RealPort protocol spec requires.
2658 case DIGI_REALPORT_SENDIMMEDIATE:
2662 spin_unlock_irqrestore(&ch->ch_lock, flags);
2663 rc = get_user(c, (unsigned char __user *)arg);
2666 spin_lock_irqsave(&ch->ch_lock, flags);
2667 ch_bd_ops->send_immediate_char(ch, c);
2668 spin_unlock_irqrestore(&ch->ch_lock, flags);
2673 * This ioctl returns all the current counts for the port.
2675 * This ioctl is to satisfy the "Line Error Counters"
2676 * call that the RealPort protocol spec requires.
2678 case DIGI_REALPORT_GETCOUNTERS:
2680 struct digi_getcounter buf;
2682 buf.norun = ch->ch_err_overrun;
2683 buf.noflow = 0; /* The driver doesn't keep this stat */
2684 buf.nframe = ch->ch_err_frame;
2685 buf.nparity = ch->ch_err_parity;
2686 buf.nbreak = ch->ch_err_break;
2687 buf.rbytes = ch->ch_rxcount;
2688 buf.tbytes = ch->ch_txcount;
2690 spin_unlock_irqrestore(&ch->ch_lock, flags);
2692 if (copy_to_user(uarg, &buf, sizeof(buf)))
2699 * This ioctl returns all current events.
2701 * This ioctl is to satisfy the "Event Reporting"
2702 * call that the RealPort protocol spec requires.
2704 case DIGI_REALPORT_GETEVENTS:
2706 unsigned int events = 0;
2708 /* NOTE: MORE EVENTS NEEDS TO BE ADDED HERE */
2709 if (ch->ch_flags & CH_BREAK_SENDING)
2711 if ((ch->ch_flags & CH_STOP) ||
2712 (ch->ch_flags & CH_FORCED_STOP))
2713 events |= (EV_OPU | EV_OPS);
2715 if ((ch->ch_flags & CH_STOPI) ||
2716 (ch->ch_flags & CH_FORCED_STOPI))
2717 events |= (EV_IPU | EV_IPS);
2719 spin_unlock_irqrestore(&ch->ch_lock, flags);
2720 return put_user(events, (unsigned int __user *)arg);
2724 * This ioctl returns TOUT and TIN counters based
2725 * upon the values passed in by the RealPort Server.
2726 * It also passes back whether the UART Transmitter is
2729 case DIGI_REALPORT_GETBUFFERS:
2731 struct digi_getbuffer buf;
2735 spin_unlock_irqrestore(&ch->ch_lock, flags);
2737 /* Get data from user first. */
2739 if (copy_from_user(&buf, uarg, sizeof(buf)))
2742 spin_lock_irqsave(&ch->ch_lock, flags);
2744 /* Figure out how much data is in our RX and TX queues. */
2746 buf.rxbuf = (ch->ch_r_head - ch->ch_r_tail) & RQUEUEMASK;
2747 buf.txbuf = (ch->ch_w_head - ch->ch_w_tail) & WQUEUEMASK;
2750 * Is the UART empty?
2751 * Add that value to whats in our TX queue.
2754 count = buf.txbuf + ch_bd_ops->get_uart_bytes_left(ch);
2757 * Figure out how much data the RealPort Server believes should
2758 * be in our TX queue.
2760 tdist = (buf.tx_in - buf.tx_out) & 0xffff;
2763 * If we have more data than the RealPort Server believes we
2764 * should have, reduce our count to its amount.
2766 * This count difference CAN happen because the Linux LD can
2767 * insert more characters into our queue for OPOST processing
2768 * that the RealPort Server doesn't know about.
2770 if (buf.txbuf > tdist)
2773 /* Report whether our queue and UART TX are completely empty. */
2780 spin_unlock_irqrestore(&ch->ch_lock, flags);
2782 if (copy_to_user(uarg, &buf, sizeof(buf)))
2788 spin_unlock_irqrestore(&ch->ch_lock, flags);
2790 return -ENOIOCTLCMD;
2793 spin_unlock_irqrestore(&ch->ch_lock, flags);