1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2003 Digi International (www.digi.com)
4 * Scott H Kilau <Scott_Kilau at digi dot com>
6 * NOTE TO LINUX KERNEL HACKERS: DO NOT REFORMAT THIS CODE!
8 * This is shared code between Digi's CVS archive and the
9 * Linux Kernel sources.
10 * Changing the source just for reformatting needlessly breaks
11 * our CVS diff history.
13 * Send any bug fixes/changes to: Eng.Linux at digi dot com.
18 #include <linux/delay.h> /* For udelay */
19 #include <linux/io.h> /* For read[bwl]/write[bwl] */
20 #include <linux/serial.h> /* For struct async_serial */
21 #include <linux/serial_reg.h> /* For the various UART offsets */
22 #include <linux/pci.h>
23 #include <linux/tty.h>
25 #include "jsm.h" /* Driver main header file */
52 static void cls_set_cts_flow_control(struct jsm_channel *ch)
54 u8 lcrb = readb(&ch->ch_cls_uart->lcr);
55 u8 ier = readb(&ch->ch_cls_uart->ier);
59 * The Enhanced Register Set may only be accessed when
60 * the Line Control Register is set to 0xBFh.
62 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
64 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
66 /* Turn on CTS flow control, turn off IXON flow control */
67 isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_CTSDSR);
68 isr_fcr &= ~(UART_EXAR654_EFR_IXON);
70 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
72 /* Write old LCR value back out, which turns enhanced access off */
73 writeb(lcrb, &ch->ch_cls_uart->lcr);
76 * Enable interrupts for CTS flow, turn off interrupts for
79 ier |= (UART_EXAR654_IER_CTSDSR);
80 ier &= ~(UART_EXAR654_IER_XOFF);
81 writeb(ier, &ch->ch_cls_uart->ier);
83 /* Set the usual FIFO values */
84 writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
86 writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
87 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
88 &ch->ch_cls_uart->isr_fcr);
93 static void cls_set_ixon_flow_control(struct jsm_channel *ch)
95 u8 lcrb = readb(&ch->ch_cls_uart->lcr);
96 u8 ier = readb(&ch->ch_cls_uart->ier);
100 * The Enhanced Register Set may only be accessed when
101 * the Line Control Register is set to 0xBFh.
103 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
105 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
107 /* Turn on IXON flow control, turn off CTS flow control */
108 isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXON);
109 isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR);
111 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
113 /* Now set our current start/stop chars while in enhanced mode */
114 writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
115 writeb(0, &ch->ch_cls_uart->lsr);
116 writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
117 writeb(0, &ch->ch_cls_uart->spr);
119 /* Write old LCR value back out, which turns enhanced access off */
120 writeb(lcrb, &ch->ch_cls_uart->lcr);
123 * Disable interrupts for CTS flow, turn on interrupts for
124 * received XOFF chars
126 ier &= ~(UART_EXAR654_IER_CTSDSR);
127 ier |= (UART_EXAR654_IER_XOFF);
128 writeb(ier, &ch->ch_cls_uart->ier);
130 /* Set the usual FIFO values */
131 writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
133 writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
134 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
135 &ch->ch_cls_uart->isr_fcr);
138 static void cls_set_no_output_flow_control(struct jsm_channel *ch)
140 u8 lcrb = readb(&ch->ch_cls_uart->lcr);
141 u8 ier = readb(&ch->ch_cls_uart->ier);
145 * The Enhanced Register Set may only be accessed when
146 * the Line Control Register is set to 0xBFh.
148 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
150 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
152 /* Turn off IXON flow control, turn off CTS flow control */
153 isr_fcr |= (UART_EXAR654_EFR_ECB);
154 isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR | UART_EXAR654_EFR_IXON);
156 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
158 /* Write old LCR value back out, which turns enhanced access off */
159 writeb(lcrb, &ch->ch_cls_uart->lcr);
162 * Disable interrupts for CTS flow, turn off interrupts for
163 * received XOFF chars
165 ier &= ~(UART_EXAR654_IER_CTSDSR);
166 ier &= ~(UART_EXAR654_IER_XOFF);
167 writeb(ier, &ch->ch_cls_uart->ier);
169 /* Set the usual FIFO values */
170 writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
172 writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
173 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
174 &ch->ch_cls_uart->isr_fcr);
176 ch->ch_r_watermark = 0;
177 ch->ch_t_tlevel = 16;
178 ch->ch_r_tlevel = 16;
181 static void cls_set_rts_flow_control(struct jsm_channel *ch)
183 u8 lcrb = readb(&ch->ch_cls_uart->lcr);
184 u8 ier = readb(&ch->ch_cls_uart->ier);
188 * The Enhanced Register Set may only be accessed when
189 * the Line Control Register is set to 0xBFh.
191 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
193 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
195 /* Turn on RTS flow control, turn off IXOFF flow control */
196 isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_RTSDTR);
197 isr_fcr &= ~(UART_EXAR654_EFR_IXOFF);
199 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
201 /* Write old LCR value back out, which turns enhanced access off */
202 writeb(lcrb, &ch->ch_cls_uart->lcr);
204 /* Enable interrupts for RTS flow */
205 ier |= (UART_EXAR654_IER_RTSDTR);
206 writeb(ier, &ch->ch_cls_uart->ier);
208 /* Set the usual FIFO values */
209 writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
211 writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
212 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
213 &ch->ch_cls_uart->isr_fcr);
215 ch->ch_r_watermark = 4;
219 static void cls_set_ixoff_flow_control(struct jsm_channel *ch)
221 u8 lcrb = readb(&ch->ch_cls_uart->lcr);
222 u8 ier = readb(&ch->ch_cls_uart->ier);
226 * The Enhanced Register Set may only be accessed when
227 * the Line Control Register is set to 0xBFh.
229 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
231 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
233 /* Turn on IXOFF flow control, turn off RTS flow control */
234 isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXOFF);
235 isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR);
237 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
239 /* Now set our current start/stop chars while in enhanced mode */
240 writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
241 writeb(0, &ch->ch_cls_uart->lsr);
242 writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
243 writeb(0, &ch->ch_cls_uart->spr);
245 /* Write old LCR value back out, which turns enhanced access off */
246 writeb(lcrb, &ch->ch_cls_uart->lcr);
248 /* Disable interrupts for RTS flow */
249 ier &= ~(UART_EXAR654_IER_RTSDTR);
250 writeb(ier, &ch->ch_cls_uart->ier);
252 /* Set the usual FIFO values */
253 writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
255 writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
256 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
257 &ch->ch_cls_uart->isr_fcr);
260 static void cls_set_no_input_flow_control(struct jsm_channel *ch)
262 u8 lcrb = readb(&ch->ch_cls_uart->lcr);
263 u8 ier = readb(&ch->ch_cls_uart->ier);
267 * The Enhanced Register Set may only be accessed when
268 * the Line Control Register is set to 0xBFh.
270 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
272 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
274 /* Turn off IXOFF flow control, turn off RTS flow control */
275 isr_fcr |= (UART_EXAR654_EFR_ECB);
276 isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR | UART_EXAR654_EFR_IXOFF);
278 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
280 /* Write old LCR value back out, which turns enhanced access off */
281 writeb(lcrb, &ch->ch_cls_uart->lcr);
283 /* Disable interrupts for RTS flow */
284 ier &= ~(UART_EXAR654_IER_RTSDTR);
285 writeb(ier, &ch->ch_cls_uart->ier);
287 /* Set the usual FIFO values */
288 writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
290 writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
291 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
292 &ch->ch_cls_uart->isr_fcr);
294 ch->ch_t_tlevel = 16;
295 ch->ch_r_tlevel = 16;
300 * Determines whether its time to shut off break condition.
302 * No locks are assumed to be held when calling this function.
303 * channel lock is held and released in this function.
305 static void cls_clear_break(struct jsm_channel *ch)
307 unsigned long lock_flags;
309 spin_lock_irqsave(&ch->ch_lock, lock_flags);
311 /* Turn break off, and unset some variables */
312 if (ch->ch_flags & CH_BREAK_SENDING) {
313 u8 temp = readb(&ch->ch_cls_uart->lcr);
315 writeb((temp & ~UART_LCR_SBC), &ch->ch_cls_uart->lcr);
317 ch->ch_flags &= ~(CH_BREAK_SENDING);
318 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
319 "clear break Finishing UART_LCR_SBC! finished: %lx\n",
322 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
325 static void cls_disable_receiver(struct jsm_channel *ch)
327 u8 tmp = readb(&ch->ch_cls_uart->ier);
329 tmp &= ~(UART_IER_RDI);
330 writeb(tmp, &ch->ch_cls_uart->ier);
333 static void cls_enable_receiver(struct jsm_channel *ch)
335 u8 tmp = readb(&ch->ch_cls_uart->ier);
337 tmp |= (UART_IER_RDI);
338 writeb(tmp, &ch->ch_cls_uart->ier);
341 /* Make the UART raise any of the output signals we want up */
342 static void cls_assert_modem_signals(struct jsm_channel *ch)
347 writeb(ch->ch_mostat, &ch->ch_cls_uart->mcr);
350 static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
362 spin_lock_irqsave(&ch->ch_lock, flags);
364 /* cache head and tail of queue */
365 head = ch->ch_r_head & RQUEUEMASK;
366 tail = ch->ch_r_tail & RQUEUEMASK;
368 /* Get our cached LSR */
369 linestatus = ch->ch_cached_lsr;
370 ch->ch_cached_lsr = 0;
372 /* Store how much space we have left in the queue */
373 qleft = tail - head - 1;
375 qleft += RQUEUEMASK + 1;
378 * Create a mask to determine whether we should
379 * insert the character (if any) into our queue.
381 if (ch->ch_c_iflag & IGNBRK)
382 error_mask |= UART_LSR_BI;
386 * Grab the linestatus register, we need to
387 * check to see if there is any data to read
389 linestatus = readb(&ch->ch_cls_uart->lsr);
391 /* Break out if there is no data to fetch */
392 if (!(linestatus & UART_LSR_DR))
396 * Discard character if we are ignoring the error mask
397 * which in this case is the break signal.
399 if (linestatus & error_mask) {
403 discard = readb(&ch->ch_cls_uart->txrx);
408 * If our queue is full, we have no choice but to drop some
409 * data. The assumption is that HWFLOW or SWFLOW should have
410 * stopped things way way before we got to this point.
412 * I decided that I wanted to ditch the oldest data first,
413 * I hope thats okay with everyone? Yes? Good.
416 tail = (tail + 1) & RQUEUEMASK;
417 ch->ch_r_tail = tail;
418 ch->ch_err_overrun++;
422 ch->ch_equeue[head] = linestatus & (UART_LSR_BI | UART_LSR_PE
424 ch->ch_rqueue[head] = readb(&ch->ch_cls_uart->txrx);
428 if (ch->ch_equeue[head] & UART_LSR_PE)
430 if (ch->ch_equeue[head] & UART_LSR_BI)
432 if (ch->ch_equeue[head] & UART_LSR_FE)
435 /* Add to, and flip head if needed */
436 head = (head + 1) & RQUEUEMASK;
441 * Write new final heads to channel structure.
443 ch->ch_r_head = head & RQUEUEMASK;
444 ch->ch_e_head = head & EQUEUEMASK;
446 spin_unlock_irqrestore(&ch->ch_lock, flags);
449 static void cls_copy_data_from_queue_to_uart(struct jsm_channel *ch)
455 struct circ_buf *circ;
460 circ = &ch->uart_port.state->xmit;
462 /* No data to write to the UART */
463 if (uart_circ_empty(circ))
466 /* If port is "stopped", don't send any data to the UART */
467 if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
470 /* We have to do it this way, because of the EXAR TXFIFO count bug. */
471 if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
476 /* cache tail of queue */
477 tail = circ->tail & (UART_XMIT_SIZE - 1);
478 qlen = uart_circ_chars_pending(circ);
480 /* Find minimum of the FIFO space, versus queue length */
484 writeb(circ->buf[tail], &ch->ch_cls_uart->txrx);
485 tail = (tail + 1) & (UART_XMIT_SIZE - 1);
491 /* Update the final tail */
492 circ->tail = tail & (UART_XMIT_SIZE - 1);
494 if (len_written > ch->ch_t_tlevel)
495 ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
497 if (uart_circ_empty(circ))
498 uart_write_wakeup(&ch->uart_port);
501 static void cls_parse_modem(struct jsm_channel *ch, u8 signals)
503 u8 msignals = signals;
505 jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
506 "neo_parse_modem: port: %d msignals: %x\n",
507 ch->ch_portnum, msignals);
510 * Scrub off lower bits.
511 * They signify delta's, which I don't care about
512 * Keep DDCD and DDSR though
516 if (msignals & UART_MSR_DDCD)
517 uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
518 if (msignals & UART_MSR_DDSR)
519 uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_CTS);
521 if (msignals & UART_MSR_DCD)
522 ch->ch_mistat |= UART_MSR_DCD;
524 ch->ch_mistat &= ~UART_MSR_DCD;
526 if (msignals & UART_MSR_DSR)
527 ch->ch_mistat |= UART_MSR_DSR;
529 ch->ch_mistat &= ~UART_MSR_DSR;
531 if (msignals & UART_MSR_RI)
532 ch->ch_mistat |= UART_MSR_RI;
534 ch->ch_mistat &= ~UART_MSR_RI;
536 if (msignals & UART_MSR_CTS)
537 ch->ch_mistat |= UART_MSR_CTS;
539 ch->ch_mistat &= ~UART_MSR_CTS;
541 jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
542 "Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
544 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
545 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
546 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
547 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
548 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
549 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
552 /* Parse the ISR register for the specific port */
553 static inline void cls_parse_isr(struct jsm_board *brd, uint port)
555 struct jsm_channel *ch;
560 * No need to verify board pointer, it was already
561 * verified in the interrupt routine.
564 if (port >= brd->nasync)
567 ch = brd->channels[port];
571 /* Here we try to figure out what caused the interrupt to happen */
573 isr = readb(&ch->ch_cls_uart->isr_fcr);
575 /* Bail if no pending interrupt on port */
576 if (isr & UART_IIR_NO_INT)
579 /* Receive Interrupt pending */
580 if (isr & (UART_IIR_RDI | UART_IIR_RDI_TIMEOUT)) {
581 /* Read data from uart -> queue */
582 cls_copy_data_from_uart_to_queue(ch);
583 jsm_check_queue_flow_control(ch);
586 /* Transmit Hold register empty pending */
587 if (isr & UART_IIR_THRI) {
588 /* Transfer data (if any) from Write Queue -> UART. */
589 spin_lock_irqsave(&ch->ch_lock, flags);
590 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
591 spin_unlock_irqrestore(&ch->ch_lock, flags);
592 cls_copy_data_from_queue_to_uart(ch);
596 * CTS/RTS change of state:
597 * Don't need to do anything, the cls_parse_modem
598 * below will grab the updated modem signals.
601 /* Parse any modem signal changes */
602 cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
606 /* Channel lock MUST be held before calling this function! */
607 static void cls_flush_uart_write(struct jsm_channel *ch)
615 writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT),
616 &ch->ch_cls_uart->isr_fcr);
618 for (i = 0; i < 10; i++) {
619 /* Check to see if the UART feels it completely flushed FIFO */
620 tmp = readb(&ch->ch_cls_uart->isr_fcr);
621 if (tmp & UART_FCR_CLEAR_XMIT) {
622 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
623 "Still flushing TX UART... i: %d\n", i);
629 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
632 /* Channel lock MUST be held before calling this function! */
633 static void cls_flush_uart_read(struct jsm_channel *ch)
639 * For complete POSIX compatibility, we should be purging the
640 * read FIFO in the UART here.
642 * However, clearing the read FIFO (UART_FCR_CLEAR_RCVR) also
643 * incorrectly flushes write data as well as just basically trashing the
646 * Presumably, this is a bug in this UART.
652 static void cls_send_start_character(struct jsm_channel *ch)
657 if (ch->ch_startc != __DISABLED_CHAR) {
659 writeb(ch->ch_startc, &ch->ch_cls_uart->txrx);
663 static void cls_send_stop_character(struct jsm_channel *ch)
668 if (ch->ch_stopc != __DISABLED_CHAR) {
670 writeb(ch->ch_stopc, &ch->ch_cls_uart->txrx);
676 * Send any/all changes to the line to the UART.
678 static void cls_param(struct jsm_channel *ch)
685 struct jsm_board *bd;
694 * If baud rate is zero, flush queues, and set mval to drop DTR.
696 if ((ch->ch_c_cflag & (CBAUD)) == 0) {
702 cls_flush_uart_write(ch);
703 cls_flush_uart_read(ch);
705 /* The baudrate is B0 so all modem lines are to be dropped. */
706 ch->ch_flags |= (CH_BAUD0);
707 ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
708 cls_assert_modem_signals(ch);
712 cflag = C_BAUD(ch->uart_port.state->port.tty);
714 for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
715 if (baud_rates[i].cflag == cflag) {
716 baud = baud_rates[i].rate;
721 if (ch->ch_flags & CH_BAUD0)
722 ch->ch_flags &= ~(CH_BAUD0);
724 if (ch->ch_c_cflag & PARENB)
725 lcr |= UART_LCR_PARITY;
727 if (!(ch->ch_c_cflag & PARODD))
728 lcr |= UART_LCR_EPAR;
731 * Not all platforms support mark/space parity,
732 * so this will hide behind an ifdef.
735 if (ch->ch_c_cflag & CMSPAR)
736 lcr |= UART_LCR_SPAR;
739 if (ch->ch_c_cflag & CSTOPB)
740 lcr |= UART_LCR_STOP;
742 switch (ch->ch_c_cflag & CSIZE) {
744 lcr |= UART_LCR_WLEN5;
747 lcr |= UART_LCR_WLEN6;
750 lcr |= UART_LCR_WLEN7;
754 lcr |= UART_LCR_WLEN8;
758 ier = readb(&ch->ch_cls_uart->ier);
759 uart_lcr = readb(&ch->ch_cls_uart->lcr);
761 quot = ch->ch_bd->bd_dividend / baud;
764 writeb(UART_LCR_DLAB, &ch->ch_cls_uart->lcr);
765 writeb((quot & 0xff), &ch->ch_cls_uart->txrx);
766 writeb((quot >> 8), &ch->ch_cls_uart->ier);
767 writeb(lcr, &ch->ch_cls_uart->lcr);
771 writeb(lcr, &ch->ch_cls_uart->lcr);
773 if (ch->ch_c_cflag & CREAD)
774 ier |= (UART_IER_RDI | UART_IER_RLSI);
776 ier |= (UART_IER_THRI | UART_IER_MSI);
778 writeb(ier, &ch->ch_cls_uart->ier);
780 if (ch->ch_c_cflag & CRTSCTS)
781 cls_set_cts_flow_control(ch);
782 else if (ch->ch_c_iflag & IXON) {
784 * If start/stop is set to disable,
785 * then we should disable flow control.
787 if ((ch->ch_startc == __DISABLED_CHAR) ||
788 (ch->ch_stopc == __DISABLED_CHAR))
789 cls_set_no_output_flow_control(ch);
791 cls_set_ixon_flow_control(ch);
793 cls_set_no_output_flow_control(ch);
795 if (ch->ch_c_cflag & CRTSCTS)
796 cls_set_rts_flow_control(ch);
797 else if (ch->ch_c_iflag & IXOFF) {
799 * If start/stop is set to disable,
800 * then we should disable flow control.
802 if ((ch->ch_startc == __DISABLED_CHAR) ||
803 (ch->ch_stopc == __DISABLED_CHAR))
804 cls_set_no_input_flow_control(ch);
806 cls_set_ixoff_flow_control(ch);
808 cls_set_no_input_flow_control(ch);
810 cls_assert_modem_signals(ch);
812 /* get current status of the modem signals now */
813 cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
819 * Classic specific interrupt handler.
821 static irqreturn_t cls_intr(int irq, void *voidbrd)
823 struct jsm_board *brd = voidbrd;
824 unsigned long lock_flags;
825 unsigned char uart_poll;
828 /* Lock out the slow poller from running on this board. */
829 spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
832 * Check the board's global interrupt offset to see if we
833 * acctually do have an interrupt pending on us.
835 uart_poll = readb(brd->re_map_membase + UART_CLASSIC_POLL_ADDR_OFFSET);
837 jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
838 __FILE__, __LINE__, uart_poll);
841 jsm_dbg(INTR, &brd->pci_dev,
842 "Kernel interrupted to me, but no pending interrupts...\n");
843 spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
847 /* At this point, we have at least SOMETHING to service, dig further. */
849 /* Parse each port to find out what caused the interrupt */
850 for (i = 0; i < brd->nasync; i++)
851 cls_parse_isr(brd, i);
853 spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
859 static void cls_uart_init(struct jsm_channel *ch)
861 unsigned char lcrb = readb(&ch->ch_cls_uart->lcr);
862 unsigned char isr_fcr = 0;
864 writeb(0, &ch->ch_cls_uart->ier);
867 * The Enhanced Register Set may only be accessed when
868 * the Line Control Register is set to 0xBFh.
870 writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
872 isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
874 /* Turn on Enhanced/Extended controls */
875 isr_fcr |= (UART_EXAR654_EFR_ECB);
877 writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
879 /* Write old LCR value back out, which turns enhanced access off */
880 writeb(lcrb, &ch->ch_cls_uart->lcr);
882 /* Clear out UART and FIFO */
883 readb(&ch->ch_cls_uart->txrx);
885 writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT),
886 &ch->ch_cls_uart->isr_fcr);
889 ch->ch_flags |= (CH_FIFO_ENABLED | CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
891 readb(&ch->ch_cls_uart->lsr);
892 readb(&ch->ch_cls_uart->msr);
898 static void cls_uart_off(struct jsm_channel *ch)
900 /* Stop all interrupts from accurring. */
901 writeb(0, &ch->ch_cls_uart->ier);
905 * cls_get_uarts_bytes_left.
906 * Returns 0 is nothing left in the FIFO, returns 1 otherwise.
908 * The channel lock MUST be held by the calling function.
910 static u32 cls_get_uart_bytes_left(struct jsm_channel *ch)
913 u8 lsr = readb(&ch->ch_cls_uart->lsr);
915 /* Determine whether the Transmitter is empty or not */
916 if (!(lsr & UART_LSR_TEMT))
919 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
928 * Starts sending a break thru the UART.
930 * The channel lock MUST be held by the calling function.
932 static void cls_send_break(struct jsm_channel *ch)
934 /* Tell the UART to start sending the break */
935 if (!(ch->ch_flags & CH_BREAK_SENDING)) {
936 u8 temp = readb(&ch->ch_cls_uart->lcr);
938 writeb((temp | UART_LCR_SBC), &ch->ch_cls_uart->lcr);
939 ch->ch_flags |= (CH_BREAK_SENDING);
944 * cls_send_immediate_char.
945 * Sends a specific character as soon as possible to the UART,
946 * jumping over any bytes that might be in the write queue.
948 * The channel lock MUST be held by the calling function.
950 static void cls_send_immediate_char(struct jsm_channel *ch, unsigned char c)
952 writeb(c, &ch->ch_cls_uart->txrx);
955 struct board_ops jsm_cls_ops = {
957 .uart_init = cls_uart_init,
958 .uart_off = cls_uart_off,
960 .assert_modem_signals = cls_assert_modem_signals,
961 .flush_uart_write = cls_flush_uart_write,
962 .flush_uart_read = cls_flush_uart_read,
963 .disable_receiver = cls_disable_receiver,
964 .enable_receiver = cls_enable_receiver,
965 .send_break = cls_send_break,
966 .clear_break = cls_clear_break,
967 .send_start_character = cls_send_start_character,
968 .send_stop_character = cls_send_stop_character,
969 .copy_data_from_queue_to_uart = cls_copy_data_from_queue_to_uart,
970 .get_uart_bytes_left = cls_get_uart_bytes_left,
971 .send_immediate_char = cls_send_immediate_char