1 /************************************************************************
2 * Copyright 2003 Digi International (www.digi.com)
4 * Copyright (C) 2004 IBM Corporation. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2, or (at your option)
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
13 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
14 * PURPOSE. See the GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
21 * Contact Information:
22 * Scott H Kilau <Scott_Kilau@digi.com>
23 * Ananda Venkatarman <mansarov@us.ibm.com>
25 * 01/19/06: changed jsm_input routine to use the dynamically allocated
26 * tty_buffer changes. Contributors: Scott Kilau and Ananda V.
27 ***********************************************************************/
28 #include <linux/tty.h>
29 #include <linux/tty_flip.h>
30 #include <linux/serial_reg.h>
31 #include <linux/delay.h> /* For udelay */
32 #include <linux/pci.h>
36 static DECLARE_BITMAP(linemap, MAXLINES);
38 static void jsm_carrier(struct jsm_channel *ch);
40 static inline int jsm_get_mstat(struct jsm_channel *ch)
45 jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
47 mstat = (ch->ch_mostat | ch->ch_mistat);
51 if (mstat & UART_MCR_DTR)
53 if (mstat & UART_MCR_RTS)
55 if (mstat & UART_MSR_CTS)
57 if (mstat & UART_MSR_DSR)
59 if (mstat & UART_MSR_RI)
61 if (mstat & UART_MSR_DCD)
64 jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
68 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
74 * Return modem signals to ld.
76 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
79 struct jsm_channel *channel = (struct jsm_channel *)port;
81 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
83 result = jsm_get_mstat(channel);
88 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
94 * jsm_set_modem_info()
96 * Set modem signals, called by ld.
98 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
100 struct jsm_channel *channel = (struct jsm_channel *)port;
102 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
104 if (mctrl & TIOCM_RTS)
105 channel->ch_mostat |= UART_MCR_RTS;
107 channel->ch_mostat &= ~UART_MCR_RTS;
109 if (mctrl & TIOCM_DTR)
110 channel->ch_mostat |= UART_MCR_DTR;
112 channel->ch_mostat &= ~UART_MCR_DTR;
114 channel->ch_bd->bd_ops->assert_modem_signals(channel);
116 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
120 static void jsm_tty_start_tx(struct uart_port *port)
122 struct jsm_channel *channel = (struct jsm_channel *)port;
124 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
126 channel->ch_flags &= ~(CH_STOP);
129 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
132 static void jsm_tty_stop_tx(struct uart_port *port)
134 struct jsm_channel *channel = (struct jsm_channel *)port;
136 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
138 channel->ch_flags |= (CH_STOP);
140 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
143 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
145 unsigned long lock_flags;
146 struct jsm_channel *channel = (struct jsm_channel *)port;
147 struct ktermios *termios;
149 spin_lock_irqsave(&port->lock, lock_flags);
150 termios = port->state->port.tty->termios;
151 if (ch == termios->c_cc[VSTART])
152 channel->ch_bd->bd_ops->send_start_character(channel);
154 if (ch == termios->c_cc[VSTOP])
155 channel->ch_bd->bd_ops->send_stop_character(channel);
156 spin_unlock_irqrestore(&port->lock, lock_flags);
159 static void jsm_tty_stop_rx(struct uart_port *port)
161 struct jsm_channel *channel = (struct jsm_channel *)port;
163 channel->ch_bd->bd_ops->disable_receiver(channel);
166 static void jsm_tty_enable_ms(struct uart_port *port)
171 static void jsm_tty_break(struct uart_port *port, int break_state)
173 unsigned long lock_flags;
174 struct jsm_channel *channel = (struct jsm_channel *)port;
176 spin_lock_irqsave(&port->lock, lock_flags);
177 if (break_state == -1)
178 channel->ch_bd->bd_ops->send_break(channel);
180 channel->ch_bd->bd_ops->clear_break(channel, 0);
182 spin_unlock_irqrestore(&port->lock, lock_flags);
185 static int jsm_tty_open(struct uart_port *port)
187 struct jsm_board *brd;
188 struct jsm_channel *channel = (struct jsm_channel *)port;
189 struct ktermios *termios;
191 /* Get board pointer from our array of majors we have allocated */
192 brd = channel->ch_bd;
195 * Allocate channel buffers for read/write/error.
196 * Set flag, so we don't get trounced on.
198 channel->ch_flags |= (CH_OPENING);
200 /* Drop locks, as malloc with GFP_KERNEL can sleep */
202 if (!channel->ch_rqueue) {
203 channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
204 if (!channel->ch_rqueue) {
205 jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
206 "unable to allocate read queue buf");
210 if (!channel->ch_equeue) {
211 channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
212 if (!channel->ch_equeue) {
213 jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
214 "unable to allocate error queue buf");
218 if (!channel->ch_wqueue) {
219 channel->ch_wqueue = kzalloc(WQUEUESIZE, GFP_KERNEL);
220 if (!channel->ch_wqueue) {
221 jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
222 "unable to allocate write queue buf");
227 channel->ch_flags &= ~(CH_OPENING);
229 * Initialize if neither terminal is open.
231 jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
232 "jsm_open: initializing channel in open...\n");
235 * Flush input queues.
237 channel->ch_r_head = channel->ch_r_tail = 0;
238 channel->ch_e_head = channel->ch_e_tail = 0;
239 channel->ch_w_head = channel->ch_w_tail = 0;
241 brd->bd_ops->flush_uart_write(channel);
242 brd->bd_ops->flush_uart_read(channel);
244 channel->ch_flags = 0;
245 channel->ch_cached_lsr = 0;
246 channel->ch_stops_sent = 0;
248 termios = port->state->port.tty->termios;
249 channel->ch_c_cflag = termios->c_cflag;
250 channel->ch_c_iflag = termios->c_iflag;
251 channel->ch_c_oflag = termios->c_oflag;
252 channel->ch_c_lflag = termios->c_lflag;
253 channel->ch_startc = termios->c_cc[VSTART];
254 channel->ch_stopc = termios->c_cc[VSTOP];
256 /* Tell UART to init itself */
257 brd->bd_ops->uart_init(channel);
260 * Run param in case we changed anything
262 brd->bd_ops->param(channel);
264 jsm_carrier(channel);
266 channel->ch_open_count++;
268 jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
272 static void jsm_tty_close(struct uart_port *port)
274 struct jsm_board *bd;
276 struct jsm_channel *channel = (struct jsm_channel *)port;
278 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
281 ts = port->state->port.tty->termios;
283 channel->ch_flags &= ~(CH_STOPI);
285 channel->ch_open_count--;
288 * If we have HUPCL set, lower DTR and RTS
290 if (channel->ch_c_cflag & HUPCL) {
291 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
292 "Close. HUPCL set, dropping DTR/RTS\n");
295 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
296 bd->bd_ops->assert_modem_signals(channel);
299 /* Turn off UART interrupts for this port */
300 channel->ch_bd->bd_ops->uart_off(channel);
302 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
305 static void jsm_tty_set_termios(struct uart_port *port,
306 struct ktermios *termios,
307 struct ktermios *old_termios)
309 unsigned long lock_flags;
310 struct jsm_channel *channel = (struct jsm_channel *)port;
312 spin_lock_irqsave(&port->lock, lock_flags);
313 channel->ch_c_cflag = termios->c_cflag;
314 channel->ch_c_iflag = termios->c_iflag;
315 channel->ch_c_oflag = termios->c_oflag;
316 channel->ch_c_lflag = termios->c_lflag;
317 channel->ch_startc = termios->c_cc[VSTART];
318 channel->ch_stopc = termios->c_cc[VSTOP];
320 channel->ch_bd->bd_ops->param(channel);
321 jsm_carrier(channel);
322 spin_unlock_irqrestore(&port->lock, lock_flags);
325 static const char *jsm_tty_type(struct uart_port *port)
330 static void jsm_tty_release_port(struct uart_port *port)
334 static int jsm_tty_request_port(struct uart_port *port)
339 static void jsm_config_port(struct uart_port *port, int flags)
341 port->type = PORT_JSM;
344 static struct uart_ops jsm_ops = {
345 .tx_empty = jsm_tty_tx_empty,
346 .set_mctrl = jsm_tty_set_mctrl,
347 .get_mctrl = jsm_tty_get_mctrl,
348 .stop_tx = jsm_tty_stop_tx,
349 .start_tx = jsm_tty_start_tx,
350 .send_xchar = jsm_tty_send_xchar,
351 .stop_rx = jsm_tty_stop_rx,
352 .enable_ms = jsm_tty_enable_ms,
353 .break_ctl = jsm_tty_break,
354 .startup = jsm_tty_open,
355 .shutdown = jsm_tty_close,
356 .set_termios = jsm_tty_set_termios,
357 .type = jsm_tty_type,
358 .release_port = jsm_tty_release_port,
359 .request_port = jsm_tty_request_port,
360 .config_port = jsm_config_port,
366 * Init the tty subsystem. Called once per board after board has been
367 * downloaded and init'ed.
369 int __devinit jsm_tty_init(struct jsm_board *brd)
373 struct jsm_channel *ch;
378 jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
381 * Initialize board structure elements.
384 brd->nasync = brd->maxports;
387 * Allocate channel memory that might not have been allocated
388 * when the driver was first loaded.
390 for (i = 0; i < brd->nasync; i++) {
391 if (!brd->channels[i]) {
394 * Okay to malloc with GFP_KERNEL, we are not at
395 * interrupt context, and there are no locks held.
397 brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL);
398 if (!brd->channels[i]) {
399 jsm_printk(CORE, ERR, &brd->pci_dev,
400 "%s:%d Unable to allocate memory for channel struct\n",
406 ch = brd->channels[0];
407 vaddr = brd->re_map_membase;
409 /* Set up channel variables */
410 for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
412 if (!brd->channels[i])
415 spin_lock_init(&ch->ch_lock);
417 if (brd->bd_uart_offset == 0x200)
418 ch->ch_neo_uart = vaddr + (brd->bd_uart_offset * i);
423 /* .25 second delay */
424 ch->ch_close_delay = 250;
426 init_waitqueue_head(&ch->ch_flags_wait);
429 jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
433 int jsm_uart_port_init(struct jsm_board *brd)
437 struct jsm_channel *ch;
442 jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
445 * Initialize board structure elements.
448 brd->nasync = brd->maxports;
450 /* Set up channel variables */
451 for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
453 if (!brd->channels[i])
456 brd->channels[i]->uart_port.irq = brd->irq;
457 brd->channels[i]->uart_port.uartclk = 14745600;
458 brd->channels[i]->uart_port.type = PORT_JSM;
459 brd->channels[i]->uart_port.iotype = UPIO_MEM;
460 brd->channels[i]->uart_port.membase = brd->re_map_membase;
461 brd->channels[i]->uart_port.fifosize = 16;
462 brd->channels[i]->uart_port.ops = &jsm_ops;
463 line = find_first_zero_bit(linemap, MAXLINES);
464 if (line >= MAXLINES) {
465 printk(KERN_INFO "jsm: linemap is full, added device failed\n");
468 set_bit(line, linemap);
469 brd->channels[i]->uart_port.line = line;
470 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
471 printk(KERN_INFO "jsm: add device failed\n");
473 printk(KERN_INFO "jsm: Port %d added\n", i);
476 jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
480 int jsm_remove_uart_port(struct jsm_board *brd)
483 struct jsm_channel *ch;
488 jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
491 * Initialize board structure elements.
494 brd->nasync = brd->maxports;
496 /* Set up channel variables */
497 for (i = 0; i < brd->nasync; i++) {
499 if (!brd->channels[i])
502 ch = brd->channels[i];
504 clear_bit(ch->uart_port.line, linemap);
505 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
508 jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
512 void jsm_input(struct jsm_channel *ch)
514 struct jsm_board *bd;
515 struct tty_struct *tp;
520 unsigned long lock_flags;
526 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
531 tp = ch->uart_port.state->port.tty;
537 spin_lock_irqsave(&ch->ch_lock, lock_flags);
540 *Figure the number of characters in the buffer.
541 *Exit immediately if none.
546 head = ch->ch_r_head & rmask;
547 tail = ch->ch_r_tail & rmask;
549 data_len = (head - tail) & rmask;
551 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
555 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
558 *If the device is not open, or CREAD is off, flush
559 *input data and return immediately.
562 !(tp->termios->c_cflag & CREAD) ) {
564 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
565 "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
566 ch->ch_r_head = tail;
568 /* Force queue flow control to be released, if needed */
569 jsm_check_queue_flow_control(ch);
571 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
576 * If we are throttled, simply don't read any data.
578 if (ch->ch_flags & CH_STOPI) {
579 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
580 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
581 "Port %d throttled, not reading any data. head: %x tail: %x\n",
582 ch->ch_portnum, head, tail);
586 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
589 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
590 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
594 len = tty_buffer_request_room(tp, data_len);
598 * n now contains the most amount of data we can copy,
599 * bounded either by the flip buffer size or the amount
600 * of data the card actually has pending...
603 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
610 * If conditions are such that ld needs to see all
611 * UART errors, we will have to walk each character
612 * and error byte and send them to the buffer one at
616 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
617 for (i = 0; i < s; i++) {
619 * Give the Linux ld the flags in the
622 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
623 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_BREAK);
624 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
625 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
626 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
627 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
629 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
632 tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
636 /* Flip queue if needed */
640 ch->ch_r_tail = tail & rmask;
641 ch->ch_e_tail = tail & rmask;
642 jsm_check_queue_flow_control(ch);
643 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
645 /* Tell the tty layer its okay to "eat" the data now */
646 tty_flip_buffer_push(tp);
648 jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
651 static void jsm_carrier(struct jsm_channel *ch)
653 struct jsm_board *bd;
655 int virt_carrier = 0;
656 int phys_carrier = 0;
658 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
667 if (ch->ch_mistat & UART_MSR_DCD) {
668 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
669 "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
673 if (ch->ch_c_cflag & CLOCAL)
676 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
677 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
680 * Test for a VIRTUAL carrier transition to HIGH.
682 if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
685 * When carrier rises, wake any threads waiting
686 * for carrier in the open routine.
689 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
690 "carrier: virt DCD rose\n");
692 if (waitqueue_active(&(ch->ch_flags_wait)))
693 wake_up_interruptible(&ch->ch_flags_wait);
697 * Test for a PHYSICAL carrier transition to HIGH.
699 if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
702 * When carrier rises, wake any threads waiting
703 * for carrier in the open routine.
706 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
707 "carrier: physical DCD rose\n");
709 if (waitqueue_active(&(ch->ch_flags_wait)))
710 wake_up_interruptible(&ch->ch_flags_wait);
714 * Test for a PHYSICAL transition to low, so long as we aren't
715 * currently ignoring physical transitions (which is what "virtual
716 * carrier" indicates).
718 * The transition of the virtual carrier to low really doesn't
719 * matter... it really only means "ignore carrier state", not
720 * "make pretend that carrier is there".
722 if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
723 && (phys_carrier == 0)) {
725 * When carrier drops:
727 * Drop carrier on all open units.
729 * Flush queues, waking up any task waiting in the
732 * Send a hangup to the control terminal.
734 * Enable all select calls.
736 if (waitqueue_active(&(ch->ch_flags_wait)))
737 wake_up_interruptible(&ch->ch_flags_wait);
741 * Make sure that our cached values reflect the current reality.
743 if (virt_carrier == 1)
744 ch->ch_flags |= CH_FCAR;
746 ch->ch_flags &= ~CH_FCAR;
748 if (phys_carrier == 1)
749 ch->ch_flags |= CH_CD;
751 ch->ch_flags &= ~CH_CD;
755 void jsm_check_queue_flow_control(struct jsm_channel *ch)
757 struct board_ops *bd_ops = ch->ch_bd->bd_ops;
760 /* Store how much space we have left in the queue */
761 if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
762 qleft += RQUEUEMASK + 1;
765 * Check to see if we should enforce flow control on our queue because
766 * the ld (or user) isn't reading data out of our queue fast enuf.
768 * NOTE: This is done based on what the current flow control of the
771 * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
772 * This will cause the UART's FIFO to back up, and force
773 * the RTS signal to be dropped.
774 * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
775 * the other side, in hopes it will stop sending data to us.
776 * 3) NONE - Nothing we can do. We will simply drop any extra data
777 * that gets sent into us when the queue fills up.
781 if (ch->ch_c_cflag & CRTSCTS) {
782 if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
783 bd_ops->disable_receiver(ch);
784 ch->ch_flags |= (CH_RECEIVER_OFF);
785 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
786 "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
791 else if (ch->ch_c_iflag & IXOFF) {
792 if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
793 bd_ops->send_stop_character(ch);
795 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
796 "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
802 * Check to see if we should unenforce flow control because
803 * ld (or user) finally read enuf data out of our queue.
805 * NOTE: This is done based on what the current flow control of the
808 * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
809 * This will cause the UART's FIFO to raise RTS back up,
810 * which will allow the other side to start sending data again.
811 * 2) SWFLOW (IXOFF) - Send a start character to
812 * the other side, so it will start sending data to us again.
813 * 3) NONE - Do nothing. Since we didn't do anything to turn off the
814 * other side, we don't need to do anything now.
816 if (qleft > (RQUEUESIZE / 2)) {
818 if (ch->ch_c_cflag & CRTSCTS) {
819 if (ch->ch_flags & CH_RECEIVER_OFF) {
820 bd_ops->enable_receiver(ch);
821 ch->ch_flags &= ~(CH_RECEIVER_OFF);
822 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
823 "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
828 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
829 ch->ch_stops_sent = 0;
830 bd_ops->send_start_character(ch);
831 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
839 * Take data from the user or kernel and send it out to the FEP.
840 * In here exists all the Transparent Print magic as well.
842 int jsm_tty_write(struct uart_port *port)
845 int data_count = 0,data_count1 =0;
850 int temp_tail = port->state->xmit.tail;
851 struct jsm_channel *channel = (struct jsm_channel *)port;
854 head = (channel->ch_w_head) & tmask;
855 tail = (channel->ch_w_tail) & tmask;
857 if ((bufcount = tail - head - 1) < 0)
858 bufcount += WQUEUESIZE;
860 bufcount = min(bufcount, 56);
861 remain = WQUEUESIZE - head;
864 if (bufcount >= remain) {
866 while ((port->state->xmit.head != temp_tail) &&
867 (data_count < remain)) {
868 channel->ch_wqueue[head++] =
869 port->state->xmit.buf[temp_tail];
872 temp_tail &= (UART_XMIT_SIZE - 1);
875 if (data_count == remain) head = 0;
881 while ((port->state->xmit.head != temp_tail) &&
882 (data_count1 < remain)) {
883 channel->ch_wqueue[head++] =
884 port->state->xmit.buf[temp_tail];
887 temp_tail &= (UART_XMIT_SIZE - 1);
893 port->state->xmit.tail = temp_tail;
895 data_count += data_count1;
898 channel->ch_w_head = head;
902 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);