xref: /openbmc/linux/drivers/tty/serial/jsm/jsm_neo.c (revision 76a4f7cc)
1 // SPDX-License-Identifier: GPL-2.0+
2 /************************************************************************
3  * Copyright 2003 Digi International (www.digi.com)
4  *
5  * Copyright (C) 2004 IBM Corporation. All rights reserved.
6  *
7  * Contact Information:
8  * Scott H Kilau <Scott_Kilau@digi.com>
9  * Wendy Xiong   <wendyx@us.ibm.com>
10  *
11  ***********************************************************************/
12 #include <linux/delay.h>	/* For udelay */
13 #include <linux/serial_reg.h>	/* For the various UART offsets */
14 #include <linux/tty.h>
15 #include <linux/pci.h>
16 #include <asm/io.h>
17 
18 #include "jsm.h"		/* Driver main header file */
19 
20 static u32 jsm_offset_table[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
21 
22 /*
23  * This function allows calls to ensure that all outstanding
24  * PCI writes have been completed, by doing a PCI read against
25  * a non-destructive, read-only location on the Neo card.
26  *
27  * In this case, we are reading the DVID (Read-only Device Identification)
28  * value of the Neo card.
29  */
30 static inline void neo_pci_posting_flush(struct jsm_board *bd)
31 {
32       readb(bd->re_map_membase + 0x8D);
33 }
34 
35 static void neo_set_cts_flow_control(struct jsm_channel *ch)
36 {
37 	u8 ier, efr;
38 	ier = readb(&ch->ch_neo_uart->ier);
39 	efr = readb(&ch->ch_neo_uart->efr);
40 
41 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting CTSFLOW\n");
42 
43 	/* Turn on auto CTS flow control */
44 	ier |= (UART_17158_IER_CTSDSR);
45 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_CTSDSR);
46 
47 	/* Turn off auto Xon flow control */
48 	efr &= ~(UART_17158_EFR_IXON);
49 
50 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
51 	writeb(0, &ch->ch_neo_uart->efr);
52 
53 	/* Turn on UART enhanced bits */
54 	writeb(efr, &ch->ch_neo_uart->efr);
55 
56 	/* Turn on table D, with 8 char hi/low watermarks */
57 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
58 
59 	/* Feed the UART our trigger levels */
60 	writeb(8, &ch->ch_neo_uart->tfifo);
61 	ch->ch_t_tlevel = 8;
62 
63 	writeb(ier, &ch->ch_neo_uart->ier);
64 }
65 
66 static void neo_set_rts_flow_control(struct jsm_channel *ch)
67 {
68 	u8 ier, efr;
69 	ier = readb(&ch->ch_neo_uart->ier);
70 	efr = readb(&ch->ch_neo_uart->efr);
71 
72 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting RTSFLOW\n");
73 
74 	/* Turn on auto RTS flow control */
75 	ier |= (UART_17158_IER_RTSDTR);
76 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_RTSDTR);
77 
78 	/* Turn off auto Xoff flow control */
79 	ier &= ~(UART_17158_IER_XOFF);
80 	efr &= ~(UART_17158_EFR_IXOFF);
81 
82 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
83 	writeb(0, &ch->ch_neo_uart->efr);
84 
85 	/* Turn on UART enhanced bits */
86 	writeb(efr, &ch->ch_neo_uart->efr);
87 
88 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
89 	ch->ch_r_watermark = 4;
90 
91 	writeb(56, &ch->ch_neo_uart->rfifo);
92 	ch->ch_r_tlevel = 56;
93 
94 	writeb(ier, &ch->ch_neo_uart->ier);
95 
96 	/*
97 	 * From the Neo UART spec sheet:
98 	 * The auto RTS/DTR function must be started by asserting
99 	 * RTS/DTR# output pin (MCR bit-0 or 1 to logic 1 after
100 	 * it is enabled.
101 	 */
102 	ch->ch_mostat |= (UART_MCR_RTS);
103 }
104 
105 
106 static void neo_set_ixon_flow_control(struct jsm_channel *ch)
107 {
108 	u8 ier, efr;
109 	ier = readb(&ch->ch_neo_uart->ier);
110 	efr = readb(&ch->ch_neo_uart->efr);
111 
112 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting IXON FLOW\n");
113 
114 	/* Turn off auto CTS flow control */
115 	ier &= ~(UART_17158_IER_CTSDSR);
116 	efr &= ~(UART_17158_EFR_CTSDSR);
117 
118 	/* Turn on auto Xon flow control */
119 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXON);
120 
121 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
122 	writeb(0, &ch->ch_neo_uart->efr);
123 
124 	/* Turn on UART enhanced bits */
125 	writeb(efr, &ch->ch_neo_uart->efr);
126 
127 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
128 	ch->ch_r_watermark = 4;
129 
130 	writeb(32, &ch->ch_neo_uart->rfifo);
131 	ch->ch_r_tlevel = 32;
132 
133 	/* Tell UART what start/stop chars it should be looking for */
134 	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
135 	writeb(0, &ch->ch_neo_uart->xonchar2);
136 
137 	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
138 	writeb(0, &ch->ch_neo_uart->xoffchar2);
139 
140 	writeb(ier, &ch->ch_neo_uart->ier);
141 }
142 
143 static void neo_set_ixoff_flow_control(struct jsm_channel *ch)
144 {
145 	u8 ier, efr;
146 	ier = readb(&ch->ch_neo_uart->ier);
147 	efr = readb(&ch->ch_neo_uart->efr);
148 
149 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting IXOFF FLOW\n");
150 
151 	/* Turn off auto RTS flow control */
152 	ier &= ~(UART_17158_IER_RTSDTR);
153 	efr &= ~(UART_17158_EFR_RTSDTR);
154 
155 	/* Turn on auto Xoff flow control */
156 	ier |= (UART_17158_IER_XOFF);
157 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
158 
159 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
160 	writeb(0, &ch->ch_neo_uart->efr);
161 
162 	/* Turn on UART enhanced bits */
163 	writeb(efr, &ch->ch_neo_uart->efr);
164 
165 	/* Turn on table D, with 8 char hi/low watermarks */
166 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
167 
168 	writeb(8, &ch->ch_neo_uart->tfifo);
169 	ch->ch_t_tlevel = 8;
170 
171 	/* Tell UART what start/stop chars it should be looking for */
172 	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
173 	writeb(0, &ch->ch_neo_uart->xonchar2);
174 
175 	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
176 	writeb(0, &ch->ch_neo_uart->xoffchar2);
177 
178 	writeb(ier, &ch->ch_neo_uart->ier);
179 }
180 
181 static void neo_set_no_input_flow_control(struct jsm_channel *ch)
182 {
183 	u8 ier, efr;
184 	ier = readb(&ch->ch_neo_uart->ier);
185 	efr = readb(&ch->ch_neo_uart->efr);
186 
187 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Unsetting Input FLOW\n");
188 
189 	/* Turn off auto RTS flow control */
190 	ier &= ~(UART_17158_IER_RTSDTR);
191 	efr &= ~(UART_17158_EFR_RTSDTR);
192 
193 	/* Turn off auto Xoff flow control */
194 	ier &= ~(UART_17158_IER_XOFF);
195 	if (ch->ch_c_iflag & IXON)
196 		efr &= ~(UART_17158_EFR_IXOFF);
197 	else
198 		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
199 
200 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
201 	writeb(0, &ch->ch_neo_uart->efr);
202 
203 	/* Turn on UART enhanced bits */
204 	writeb(efr, &ch->ch_neo_uart->efr);
205 
206 	/* Turn on table D, with 8 char hi/low watermarks */
207 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
208 
209 	ch->ch_r_watermark = 0;
210 
211 	writeb(16, &ch->ch_neo_uart->tfifo);
212 	ch->ch_t_tlevel = 16;
213 
214 	writeb(16, &ch->ch_neo_uart->rfifo);
215 	ch->ch_r_tlevel = 16;
216 
217 	writeb(ier, &ch->ch_neo_uart->ier);
218 }
219 
220 static void neo_set_no_output_flow_control(struct jsm_channel *ch)
221 {
222 	u8 ier, efr;
223 	ier = readb(&ch->ch_neo_uart->ier);
224 	efr = readb(&ch->ch_neo_uart->efr);
225 
226 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Unsetting Output FLOW\n");
227 
228 	/* Turn off auto CTS flow control */
229 	ier &= ~(UART_17158_IER_CTSDSR);
230 	efr &= ~(UART_17158_EFR_CTSDSR);
231 
232 	/* Turn off auto Xon flow control */
233 	if (ch->ch_c_iflag & IXOFF)
234 		efr &= ~(UART_17158_EFR_IXON);
235 	else
236 		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXON);
237 
238 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
239 	writeb(0, &ch->ch_neo_uart->efr);
240 
241 	/* Turn on UART enhanced bits */
242 	writeb(efr, &ch->ch_neo_uart->efr);
243 
244 	/* Turn on table D, with 8 char hi/low watermarks */
245 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
246 
247 	ch->ch_r_watermark = 0;
248 
249 	writeb(16, &ch->ch_neo_uart->tfifo);
250 	ch->ch_t_tlevel = 16;
251 
252 	writeb(16, &ch->ch_neo_uart->rfifo);
253 	ch->ch_r_tlevel = 16;
254 
255 	writeb(ier, &ch->ch_neo_uart->ier);
256 }
257 
258 static inline void neo_set_new_start_stop_chars(struct jsm_channel *ch)
259 {
260 
261 	/* if hardware flow control is set, then skip this whole thing */
262 	if (ch->ch_c_cflag & CRTSCTS)
263 		return;
264 
265 	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "start\n");
266 
267 	/* Tell UART what start/stop chars it should be looking for */
268 	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
269 	writeb(0, &ch->ch_neo_uart->xonchar2);
270 
271 	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
272 	writeb(0, &ch->ch_neo_uart->xoffchar2);
273 }
274 
275 static void neo_copy_data_from_uart_to_queue(struct jsm_channel *ch)
276 {
277 	int qleft = 0;
278 	u8 linestatus = 0;
279 	u8 error_mask = 0;
280 	int n = 0;
281 	int total = 0;
282 	u16 head;
283 	u16 tail;
284 
285 	/* cache head and tail of queue */
286 	head = ch->ch_r_head & RQUEUEMASK;
287 	tail = ch->ch_r_tail & RQUEUEMASK;
288 
289 	/* Get our cached LSR */
290 	linestatus = ch->ch_cached_lsr;
291 	ch->ch_cached_lsr = 0;
292 
293 	/* Store how much space we have left in the queue */
294 	if ((qleft = tail - head - 1) < 0)
295 		qleft += RQUEUEMASK + 1;
296 
297 	/*
298 	 * If the UART is not in FIFO mode, force the FIFO copy to
299 	 * NOT be run, by setting total to 0.
300 	 *
301 	 * On the other hand, if the UART IS in FIFO mode, then ask
302 	 * the UART to give us an approximation of data it has RX'ed.
303 	 */
304 	if (!(ch->ch_flags & CH_FIFO_ENABLED))
305 		total = 0;
306 	else {
307 		total = readb(&ch->ch_neo_uart->rfifo);
308 
309 		/*
310 		 * EXAR chip bug - RX FIFO COUNT - Fudge factor.
311 		 *
312 		 * This resolves a problem/bug with the Exar chip that sometimes
313 		 * returns a bogus value in the rfifo register.
314 		 * The count can be any where from 0-3 bytes "off".
315 		 * Bizarre, but true.
316 		 */
317 		total -= 3;
318 	}
319 
320 	/*
321 	 * Finally, bound the copy to make sure we don't overflow
322 	 * our own queue...
323 	 * The byte by byte copy loop below this loop this will
324 	 * deal with the queue overflow possibility.
325 	 */
326 	total = min(total, qleft);
327 
328 	while (total > 0) {
329 		/*
330 		 * Grab the linestatus register, we need to check
331 		 * to see if there are any errors in the FIFO.
332 		 */
333 		linestatus = readb(&ch->ch_neo_uart->lsr);
334 
335 		/*
336 		 * Break out if there is a FIFO error somewhere.
337 		 * This will allow us to go byte by byte down below,
338 		 * finding the exact location of the error.
339 		 */
340 		if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
341 			break;
342 
343 		/* Make sure we don't go over the end of our queue */
344 		n = min(((u32) total), (RQUEUESIZE - (u32) head));
345 
346 		/*
347 		 * Cut down n even further if needed, this is to fix
348 		 * a problem with memcpy_fromio() with the Neo on the
349 		 * IBM pSeries platform.
350 		 * 15 bytes max appears to be the magic number.
351 		 */
352 		n = min((u32) n, (u32) 12);
353 
354 		/*
355 		 * Since we are grabbing the linestatus register, which
356 		 * will reset some bits after our read, we need to ensure
357 		 * we don't miss our TX FIFO emptys.
358 		 */
359 		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
360 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
361 
362 		linestatus = 0;
363 
364 		/* Copy data from uart to the queue */
365 		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
366 		/*
367 		 * Since RX_FIFO_DATA_ERROR was 0, we are guaranteed
368 		 * that all the data currently in the FIFO is free of
369 		 * breaks and parity/frame/orun errors.
370 		 */
371 		memset(ch->ch_equeue + head, 0, n);
372 
373 		/* Add to and flip head if needed */
374 		head = (head + n) & RQUEUEMASK;
375 		total -= n;
376 		qleft -= n;
377 		ch->ch_rxcount += n;
378 	}
379 
380 	/*
381 	 * Create a mask to determine whether we should
382 	 * insert the character (if any) into our queue.
383 	 */
384 	if (ch->ch_c_iflag & IGNBRK)
385 		error_mask |= UART_LSR_BI;
386 
387 	/*
388 	 * Now cleanup any leftover bytes still in the UART.
389 	 * Also deal with any possible queue overflow here as well.
390 	 */
391 	while (1) {
392 
393 		/*
394 		 * Its possible we have a linestatus from the loop above
395 		 * this, so we "OR" on any extra bits.
396 		 */
397 		linestatus |= readb(&ch->ch_neo_uart->lsr);
398 
399 		/*
400 		 * If the chip tells us there is no more data pending to
401 		 * be read, we can then leave.
402 		 * But before we do, cache the linestatus, just in case.
403 		 */
404 		if (!(linestatus & UART_LSR_DR)) {
405 			ch->ch_cached_lsr = linestatus;
406 			break;
407 		}
408 
409 		/* No need to store this bit */
410 		linestatus &= ~UART_LSR_DR;
411 
412 		/*
413 		 * Since we are grabbing the linestatus register, which
414 		 * will reset some bits after our read, we need to ensure
415 		 * we don't miss our TX FIFO emptys.
416 		 */
417 		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
418 			linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
419 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
420 		}
421 
422 		/*
423 		 * Discard character if we are ignoring the error mask.
424 		 */
425 		if (linestatus & error_mask) {
426 			u8 discard;
427 			linestatus = 0;
428 			memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
429 			continue;
430 		}
431 
432 		/*
433 		 * If our queue is full, we have no choice but to drop some data.
434 		 * The assumption is that HWFLOW or SWFLOW should have stopped
435 		 * things way way before we got to this point.
436 		 *
437 		 * I decided that I wanted to ditch the oldest data first,
438 		 * I hope thats okay with everyone? Yes? Good.
439 		 */
440 		while (qleft < 1) {
441 			jsm_dbg(READ, &ch->ch_bd->pci_dev,
442 				"Queue full, dropping DATA:%x LSR:%x\n",
443 				ch->ch_rqueue[tail], ch->ch_equeue[tail]);
444 
445 			ch->ch_r_tail = tail = (tail + 1) & RQUEUEMASK;
446 			ch->ch_err_overrun++;
447 			qleft++;
448 		}
449 
450 		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
451 		ch->ch_equeue[head] = (u8) linestatus;
452 
453 		jsm_dbg(READ, &ch->ch_bd->pci_dev, "DATA/LSR pair: %x %x\n",
454 			ch->ch_rqueue[head], ch->ch_equeue[head]);
455 
456 		/* Ditch any remaining linestatus value. */
457 		linestatus = 0;
458 
459 		/* Add to and flip head if needed */
460 		head = (head + 1) & RQUEUEMASK;
461 
462 		qleft--;
463 		ch->ch_rxcount++;
464 	}
465 
466 	/*
467 	 * Write new final heads to channel structure.
468 	 */
469 	ch->ch_r_head = head & RQUEUEMASK;
470 	ch->ch_e_head = head & EQUEUEMASK;
471 	jsm_input(ch);
472 }
473 
474 static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
475 {
476 	u16 head;
477 	u16 tail;
478 	int n;
479 	int s;
480 	int qlen;
481 	u32 len_written = 0;
482 	struct circ_buf *circ;
483 
484 	if (!ch)
485 		return;
486 
487 	circ = &ch->uart_port.state->xmit;
488 
489 	/* No data to write to the UART */
490 	if (uart_circ_empty(circ))
491 		return;
492 
493 	/* If port is "stopped", don't send any data to the UART */
494 	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
495 		return;
496 	/*
497 	 * If FIFOs are disabled. Send data directly to txrx register
498 	 */
499 	if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
500 		u8 lsrbits = readb(&ch->ch_neo_uart->lsr);
501 
502 		ch->ch_cached_lsr |= lsrbits;
503 		if (ch->ch_cached_lsr & UART_LSR_THRE) {
504 			ch->ch_cached_lsr &= ~(UART_LSR_THRE);
505 
506 			writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
507 			jsm_dbg(WRITE, &ch->ch_bd->pci_dev,
508 				"Tx data: %x\n", circ->buf[circ->tail]);
509 			circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
510 			ch->ch_txcount++;
511 		}
512 		return;
513 	}
514 
515 	/*
516 	 * We have to do it this way, because of the EXAR TXFIFO count bug.
517 	 */
518 	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
519 		return;
520 
521 	n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
522 
523 	/* cache head and tail of queue */
524 	head = circ->head & (UART_XMIT_SIZE - 1);
525 	tail = circ->tail & (UART_XMIT_SIZE - 1);
526 	qlen = uart_circ_chars_pending(circ);
527 
528 	/* Find minimum of the FIFO space, versus queue length */
529 	n = min(n, qlen);
530 
531 	while (n > 0) {
532 
533 		s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
534 		s = min(s, n);
535 
536 		if (s <= 0)
537 			break;
538 
539 		memcpy_toio(&ch->ch_neo_uart->txrxburst, circ->buf + tail, s);
540 		/* Add and flip queue if needed */
541 		tail = (tail + s) & (UART_XMIT_SIZE - 1);
542 		n -= s;
543 		ch->ch_txcount += s;
544 		len_written += s;
545 	}
546 
547 	/* Update the final tail */
548 	circ->tail = tail & (UART_XMIT_SIZE - 1);
549 
550 	if (len_written >= ch->ch_t_tlevel)
551 		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
552 
553 	if (uart_circ_empty(circ))
554 		uart_write_wakeup(&ch->uart_port);
555 }
556 
557 static void neo_parse_modem(struct jsm_channel *ch, u8 signals)
558 {
559 	u8 msignals = signals;
560 
561 	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
562 		"neo_parse_modem: port: %d msignals: %x\n",
563 		ch->ch_portnum, msignals);
564 
565 	/* Scrub off lower bits. They signify delta's, which I don't care about */
566 	/* Keep DDCD and DDSR though */
567 	msignals &= 0xf8;
568 
569 	if (msignals & UART_MSR_DDCD)
570 		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
571 	if (msignals & UART_MSR_DDSR)
572 		uart_handle_cts_change(&ch->uart_port, msignals & UART_MSR_CTS);
573 	if (msignals & UART_MSR_DCD)
574 		ch->ch_mistat |= UART_MSR_DCD;
575 	else
576 		ch->ch_mistat &= ~UART_MSR_DCD;
577 
578 	if (msignals & UART_MSR_DSR)
579 		ch->ch_mistat |= UART_MSR_DSR;
580 	else
581 		ch->ch_mistat &= ~UART_MSR_DSR;
582 
583 	if (msignals & UART_MSR_RI)
584 		ch->ch_mistat |= UART_MSR_RI;
585 	else
586 		ch->ch_mistat &= ~UART_MSR_RI;
587 
588 	if (msignals & UART_MSR_CTS)
589 		ch->ch_mistat |= UART_MSR_CTS;
590 	else
591 		ch->ch_mistat &= ~UART_MSR_CTS;
592 
593 	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
594 		"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
595 		ch->ch_portnum,
596 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
597 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
598 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
599 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
600 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
601 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
602 }
603 
604 /* Make the UART raise any of the output signals we want up */
605 static void neo_assert_modem_signals(struct jsm_channel *ch)
606 {
607 	if (!ch)
608 		return;
609 
610 	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
611 
612 	/* flush write operation */
613 	neo_pci_posting_flush(ch->ch_bd);
614 }
615 
616 /*
617  * Flush the WRITE FIFO on the Neo.
618  *
619  * NOTE: Channel lock MUST be held before calling this function!
620  */
621 static void neo_flush_uart_write(struct jsm_channel *ch)
622 {
623 	u8 tmp = 0;
624 	int i = 0;
625 
626 	if (!ch)
627 		return;
628 
629 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
630 
631 	for (i = 0; i < 10; i++) {
632 
633 		/* Check to see if the UART feels it completely flushed the FIFO. */
634 		tmp = readb(&ch->ch_neo_uart->isr_fcr);
635 		if (tmp & UART_FCR_CLEAR_XMIT) {
636 			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
637 				"Still flushing TX UART... i: %d\n", i);
638 			udelay(10);
639 		}
640 		else
641 			break;
642 	}
643 
644 	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
645 }
646 
647 
648 /*
649  * Flush the READ FIFO on the Neo.
650  *
651  * NOTE: Channel lock MUST be held before calling this function!
652  */
653 static void neo_flush_uart_read(struct jsm_channel *ch)
654 {
655 	u8 tmp = 0;
656 	int i = 0;
657 
658 	if (!ch)
659 		return;
660 
661 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
662 
663 	for (i = 0; i < 10; i++) {
664 
665 		/* Check to see if the UART feels it completely flushed the FIFO. */
666 		tmp = readb(&ch->ch_neo_uart->isr_fcr);
667 		if (tmp & 2) {
668 			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
669 				"Still flushing RX UART... i: %d\n", i);
670 			udelay(10);
671 		}
672 		else
673 			break;
674 	}
675 }
676 
677 /*
678  * No locks are assumed to be held when calling this function.
679  */
680 static void neo_clear_break(struct jsm_channel *ch)
681 {
682 	unsigned long lock_flags;
683 
684 	spin_lock_irqsave(&ch->ch_lock, lock_flags);
685 
686 	/* Turn break off, and unset some variables */
687 	if (ch->ch_flags & CH_BREAK_SENDING) {
688 		u8 temp = readb(&ch->ch_neo_uart->lcr);
689 		writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
690 
691 		ch->ch_flags &= ~(CH_BREAK_SENDING);
692 		jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
693 			"clear break Finishing UART_LCR_SBC! finished: %lx\n",
694 			jiffies);
695 
696 		/* flush write operation */
697 		neo_pci_posting_flush(ch->ch_bd);
698 	}
699 	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
700 }
701 
702 /*
703  * Parse the ISR register.
704  */
705 static void neo_parse_isr(struct jsm_board *brd, u32 port)
706 {
707 	struct jsm_channel *ch;
708 	u8 isr;
709 	u8 cause;
710 	unsigned long lock_flags;
711 
712 	if (!brd)
713 		return;
714 
715 	if (port >= brd->maxports)
716 		return;
717 
718 	ch = brd->channels[port];
719 	if (!ch)
720 		return;
721 
722 	/* Here we try to figure out what caused the interrupt to happen */
723 	while (1) {
724 
725 		isr = readb(&ch->ch_neo_uart->isr_fcr);
726 
727 		/* Bail if no pending interrupt */
728 		if (isr & UART_IIR_NO_INT)
729 			break;
730 
731 		/*
732 		 * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
733 		 */
734 		isr &= ~(UART_17158_IIR_FIFO_ENABLED);
735 
736 		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d isr: %x\n",
737 			__FILE__, __LINE__, isr);
738 
739 		if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
740 			/* Read data from uart -> queue */
741 			neo_copy_data_from_uart_to_queue(ch);
742 
743 			/* Call our tty layer to enforce queue flow control if needed. */
744 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
745 			jsm_check_queue_flow_control(ch);
746 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
747 		}
748 
749 		if (isr & UART_IIR_THRI) {
750 			/* Transfer data (if any) from Write Queue -> UART. */
751 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
752 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
753 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
754 			neo_copy_data_from_queue_to_uart(ch);
755 		}
756 
757 		if (isr & UART_17158_IIR_XONXOFF) {
758 			cause = readb(&ch->ch_neo_uart->xoffchar1);
759 
760 			jsm_dbg(INTR, &ch->ch_bd->pci_dev,
761 				"Port %d. Got ISR_XONXOFF: cause:%x\n",
762 				port, cause);
763 
764 			/*
765 			 * Since the UART detected either an XON or
766 			 * XOFF match, we need to figure out which
767 			 * one it was, so we can suspend or resume data flow.
768 			 */
769 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
770 			if (cause == UART_17158_XON_DETECT) {
771 				/* Is output stopped right now, if so, resume it */
772 				if (brd->channels[port]->ch_flags & CH_STOP) {
773 					ch->ch_flags &= ~(CH_STOP);
774 				}
775 				jsm_dbg(INTR, &ch->ch_bd->pci_dev,
776 					"Port %d. XON detected in incoming data\n",
777 					port);
778 			}
779 			else if (cause == UART_17158_XOFF_DETECT) {
780 				if (!(brd->channels[port]->ch_flags & CH_STOP)) {
781 					ch->ch_flags |= CH_STOP;
782 					jsm_dbg(INTR, &ch->ch_bd->pci_dev,
783 						"Setting CH_STOP\n");
784 				}
785 				jsm_dbg(INTR, &ch->ch_bd->pci_dev,
786 					"Port: %d. XOFF detected in incoming data\n",
787 					port);
788 			}
789 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
790 		}
791 
792 		if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
793 			/*
794 			 * If we get here, this means the hardware is doing auto flow control.
795 			 * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
796 			 */
797 			cause = readb(&ch->ch_neo_uart->mcr);
798 
799 			/* Which pin is doing auto flow? RTS or DTR? */
800 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
801 			if ((cause & 0x4) == 0) {
802 				if (cause & UART_MCR_RTS)
803 					ch->ch_mostat |= UART_MCR_RTS;
804 				else
805 					ch->ch_mostat &= ~(UART_MCR_RTS);
806 			} else {
807 				if (cause & UART_MCR_DTR)
808 					ch->ch_mostat |= UART_MCR_DTR;
809 				else
810 					ch->ch_mostat &= ~(UART_MCR_DTR);
811 			}
812 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
813 		}
814 
815 		/* Parse any modem signal changes */
816 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
817 			"MOD_STAT: sending to parse_modem_sigs\n");
818 		spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
819 		neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
820 		spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
821 	}
822 }
823 
824 static inline void neo_parse_lsr(struct jsm_board *brd, u32 port)
825 {
826 	struct jsm_channel *ch;
827 	int linestatus;
828 	unsigned long lock_flags;
829 
830 	if (!brd)
831 		return;
832 
833 	if (port >= brd->maxports)
834 		return;
835 
836 	ch = brd->channels[port];
837 	if (!ch)
838 		return;
839 
840 	linestatus = readb(&ch->ch_neo_uart->lsr);
841 
842 	jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d port: %d linestatus: %x\n",
843 		__FILE__, __LINE__, port, linestatus);
844 
845 	ch->ch_cached_lsr |= linestatus;
846 
847 	if (ch->ch_cached_lsr & UART_LSR_DR) {
848 		/* Read data from uart -> queue */
849 		neo_copy_data_from_uart_to_queue(ch);
850 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
851 		jsm_check_queue_flow_control(ch);
852 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
853 	}
854 
855 	/*
856 	 * This is a special flag. It indicates that at least 1
857 	 * RX error (parity, framing, or break) has happened.
858 	 * Mark this in our struct, which will tell me that I have
859 	 *to do the special RX+LSR read for this FIFO load.
860 	 */
861 	if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
862 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
863 			"%s:%d Port: %d Got an RX error, need to parse LSR\n",
864 			__FILE__, __LINE__, port);
865 
866 	/*
867 	 * The next 3 tests should *NOT* happen, as the above test
868 	 * should encapsulate all 3... At least, thats what Exar says.
869 	 */
870 
871 	if (linestatus & UART_LSR_PE) {
872 		ch->ch_err_parity++;
873 		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. PAR ERR!\n",
874 			__FILE__, __LINE__, port);
875 	}
876 
877 	if (linestatus & UART_LSR_FE) {
878 		ch->ch_err_frame++;
879 		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. FRM ERR!\n",
880 			__FILE__, __LINE__, port);
881 	}
882 
883 	if (linestatus & UART_LSR_BI) {
884 		ch->ch_err_break++;
885 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
886 			"%s:%d Port: %d. BRK INTR!\n",
887 			__FILE__, __LINE__, port);
888 	}
889 
890 	if (linestatus & UART_LSR_OE) {
891 		/*
892 		 * Rx Oruns. Exar says that an orun will NOT corrupt
893 		 * the FIFO. It will just replace the holding register
894 		 * with this new data byte. So basically just ignore this.
895 		 * Probably we should eventually have an orun stat in our driver...
896 		 */
897 		ch->ch_err_overrun++;
898 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
899 			"%s:%d Port: %d. Rx Overrun!\n",
900 			__FILE__, __LINE__, port);
901 	}
902 
903 	if (linestatus & UART_LSR_THRE) {
904 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
905 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
906 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
907 
908 		/* Transfer data (if any) from Write Queue -> UART. */
909 		neo_copy_data_from_queue_to_uart(ch);
910 	}
911 	else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
912 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
913 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
914 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
915 
916 		/* Transfer data (if any) from Write Queue -> UART. */
917 		neo_copy_data_from_queue_to_uart(ch);
918 	}
919 }
920 
921 /*
922  * neo_param()
923  * Send any/all changes to the line to the UART.
924  */
925 static void neo_param(struct jsm_channel *ch)
926 {
927 	u8 lcr = 0;
928 	u8 uart_lcr, ier;
929 	u32 baud;
930 	int quot;
931 	struct jsm_board *bd;
932 
933 	bd = ch->ch_bd;
934 	if (!bd)
935 		return;
936 
937 	/*
938 	 * If baud rate is zero, flush queues, and set mval to drop DTR.
939 	 */
940 	if ((ch->ch_c_cflag & (CBAUD)) == 0) {
941 		ch->ch_r_head = ch->ch_r_tail = 0;
942 		ch->ch_e_head = ch->ch_e_tail = 0;
943 
944 		neo_flush_uart_write(ch);
945 		neo_flush_uart_read(ch);
946 
947 		ch->ch_flags |= (CH_BAUD0);
948 		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
949 		neo_assert_modem_signals(ch);
950 		return;
951 
952 	} else {
953 		int i;
954 		unsigned int cflag;
955 		static struct {
956 			unsigned int rate;
957 			unsigned int cflag;
958 		} baud_rates[] = {
959 			{ 921600, B921600 },
960 			{ 460800, B460800 },
961 			{ 230400, B230400 },
962 			{ 115200, B115200 },
963 			{  57600, B57600  },
964 			{  38400, B38400  },
965 			{  19200, B19200  },
966 			{   9600, B9600   },
967 			{   4800, B4800   },
968 			{   2400, B2400   },
969 			{   1200, B1200   },
970 			{    600, B600    },
971 			{    300, B300    },
972 			{    200, B200    },
973 			{    150, B150    },
974 			{    134, B134    },
975 			{    110, B110    },
976 			{     75, B75     },
977 			{     50, B50     },
978 		};
979 
980 		cflag = C_BAUD(ch->uart_port.state->port.tty);
981 		baud = 9600;
982 		for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
983 			if (baud_rates[i].cflag == cflag) {
984 				baud = baud_rates[i].rate;
985 				break;
986 			}
987 		}
988 
989 		if (ch->ch_flags & CH_BAUD0)
990 			ch->ch_flags &= ~(CH_BAUD0);
991 	}
992 
993 	if (ch->ch_c_cflag & PARENB)
994 		lcr |= UART_LCR_PARITY;
995 
996 	if (!(ch->ch_c_cflag & PARODD))
997 		lcr |= UART_LCR_EPAR;
998 
999 	/*
1000 	 * Not all platforms support mark/space parity,
1001 	 * so this will hide behind an ifdef.
1002 	 */
1003 #ifdef CMSPAR
1004 	if (ch->ch_c_cflag & CMSPAR)
1005 		lcr |= UART_LCR_SPAR;
1006 #endif
1007 
1008 	if (ch->ch_c_cflag & CSTOPB)
1009 		lcr |= UART_LCR_STOP;
1010 
1011 	switch (ch->ch_c_cflag & CSIZE) {
1012 	case CS5:
1013 		lcr |= UART_LCR_WLEN5;
1014 		break;
1015 	case CS6:
1016 		lcr |= UART_LCR_WLEN6;
1017 		break;
1018 	case CS7:
1019 		lcr |= UART_LCR_WLEN7;
1020 		break;
1021 	case CS8:
1022 	default:
1023 		lcr |= UART_LCR_WLEN8;
1024 	break;
1025 	}
1026 
1027 	ier = readb(&ch->ch_neo_uart->ier);
1028 	uart_lcr = readb(&ch->ch_neo_uart->lcr);
1029 
1030 	quot = ch->ch_bd->bd_dividend / baud;
1031 
1032 	if (quot != 0) {
1033 		writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
1034 		writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
1035 		writeb((quot >> 8), &ch->ch_neo_uart->ier);
1036 		writeb(lcr, &ch->ch_neo_uart->lcr);
1037 	}
1038 
1039 	if (uart_lcr != lcr)
1040 		writeb(lcr, &ch->ch_neo_uart->lcr);
1041 
1042 	if (ch->ch_c_cflag & CREAD)
1043 		ier |= (UART_IER_RDI | UART_IER_RLSI);
1044 
1045 	ier |= (UART_IER_THRI | UART_IER_MSI);
1046 
1047 	writeb(ier, &ch->ch_neo_uart->ier);
1048 
1049 	/* Set new start/stop chars */
1050 	neo_set_new_start_stop_chars(ch);
1051 
1052 	if (ch->ch_c_cflag & CRTSCTS)
1053 		neo_set_cts_flow_control(ch);
1054 	else if (ch->ch_c_iflag & IXON) {
1055 		/* If start/stop is set to disable, then we should disable flow control */
1056 		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1057 			neo_set_no_output_flow_control(ch);
1058 		else
1059 			neo_set_ixon_flow_control(ch);
1060 	}
1061 	else
1062 		neo_set_no_output_flow_control(ch);
1063 
1064 	if (ch->ch_c_cflag & CRTSCTS)
1065 		neo_set_rts_flow_control(ch);
1066 	else if (ch->ch_c_iflag & IXOFF) {
1067 		/* If start/stop is set to disable, then we should disable flow control */
1068 		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1069 			neo_set_no_input_flow_control(ch);
1070 		else
1071 			neo_set_ixoff_flow_control(ch);
1072 	}
1073 	else
1074 		neo_set_no_input_flow_control(ch);
1075 	/*
1076 	 * Adjust the RX FIFO Trigger level if baud is less than 9600.
1077 	 * Not exactly elegant, but this is needed because of the Exar chip's
1078 	 * delay on firing off the RX FIFO interrupt on slower baud rates.
1079 	 */
1080 	if (baud < 9600) {
1081 		writeb(1, &ch->ch_neo_uart->rfifo);
1082 		ch->ch_r_tlevel = 1;
1083 	}
1084 
1085 	neo_assert_modem_signals(ch);
1086 
1087 	/* Get current status of the modem signals now */
1088 	neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
1089 	return;
1090 }
1091 
1092 /*
1093  * jsm_neo_intr()
1094  *
1095  * Neo specific interrupt handler.
1096  */
1097 static irqreturn_t neo_intr(int irq, void *voidbrd)
1098 {
1099 	struct jsm_board *brd = voidbrd;
1100 	struct jsm_channel *ch;
1101 	int port = 0;
1102 	int type = 0;
1103 	int current_port;
1104 	u32 tmp;
1105 	u32 uart_poll;
1106 	unsigned long lock_flags;
1107 	unsigned long lock_flags2;
1108 	int outofloop_count = 0;
1109 
1110 	/* Lock out the slow poller from running on this board. */
1111 	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
1112 
1113 	/*
1114 	 * Read in "extended" IRQ information from the 32bit Neo register.
1115 	 * Bits 0-7: What port triggered the interrupt.
1116 	 * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
1117 	 */
1118 	uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
1119 
1120 	jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
1121 		__FILE__, __LINE__, uart_poll);
1122 
1123 	if (!uart_poll) {
1124 		jsm_dbg(INTR, &brd->pci_dev,
1125 			"Kernel interrupted to me, but no pending interrupts...\n");
1126 		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1127 		return IRQ_NONE;
1128 	}
1129 
1130 	/* At this point, we have at least SOMETHING to service, dig further... */
1131 
1132 	current_port = 0;
1133 
1134 	/* Loop on each port */
1135 	while (((uart_poll & 0xff) != 0) && (outofloop_count < 0xff)){
1136 
1137 		tmp = uart_poll;
1138 		outofloop_count++;
1139 
1140 		/* Check current port to see if it has interrupt pending */
1141 		if ((tmp & jsm_offset_table[current_port]) != 0) {
1142 			port = current_port;
1143 			type = tmp >> (8 + (port * 3));
1144 			type &= 0x7;
1145 		} else {
1146 			current_port++;
1147 			continue;
1148 		}
1149 
1150 		jsm_dbg(INTR, &brd->pci_dev, "%s:%d port: %x type: %x\n",
1151 			__FILE__, __LINE__, port, type);
1152 
1153 		/* Remove this port + type from uart_poll */
1154 		uart_poll &= ~(jsm_offset_table[port]);
1155 
1156 		if (!type) {
1157 			/* If no type, just ignore it, and move onto next port */
1158 			jsm_dbg(INTR, &brd->pci_dev,
1159 				"Interrupt with no type! port: %d\n", port);
1160 			continue;
1161 		}
1162 
1163 		/* Switch on type of interrupt we have */
1164 		switch (type) {
1165 
1166 		case UART_17158_RXRDY_TIMEOUT:
1167 			/*
1168 			 * RXRDY Time-out is cleared by reading data in the
1169 			* RX FIFO until it falls below the trigger level.
1170 			 */
1171 
1172 			/* Verify the port is in range. */
1173 			if (port >= brd->nasync)
1174 				continue;
1175 
1176 			ch = brd->channels[port];
1177 			if (!ch)
1178 				continue;
1179 
1180 			neo_copy_data_from_uart_to_queue(ch);
1181 
1182 			/* Call our tty layer to enforce queue flow control if needed. */
1183 			spin_lock_irqsave(&ch->ch_lock, lock_flags2);
1184 			jsm_check_queue_flow_control(ch);
1185 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags2);
1186 
1187 			continue;
1188 
1189 		case UART_17158_RX_LINE_STATUS:
1190 			/*
1191 			 * RXRDY and RX LINE Status (logic OR of LSR[4:1])
1192 			 */
1193 			neo_parse_lsr(brd, port);
1194 			continue;
1195 
1196 		case UART_17158_TXRDY:
1197 			/*
1198 			 * TXRDY interrupt clears after reading ISR register for the UART channel.
1199 			 */
1200 
1201 			/*
1202 			 * Yes, this is odd...
1203 			 * Why would I check EVERY possibility of type of
1204 			 * interrupt, when we know its TXRDY???
1205 			 * Becuz for some reason, even tho we got triggered for TXRDY,
1206 			 * it seems to be occasionally wrong. Instead of TX, which
1207 			 * it should be, I was getting things like RXDY too. Weird.
1208 			 */
1209 			neo_parse_isr(brd, port);
1210 			continue;
1211 
1212 		case UART_17158_MSR:
1213 			/*
1214 			 * MSR or flow control was seen.
1215 			 */
1216 			neo_parse_isr(brd, port);
1217 			continue;
1218 
1219 		default:
1220 			/*
1221 			 * The UART triggered us with a bogus interrupt type.
1222 			 * It appears the Exar chip, when REALLY bogged down, will throw
1223 			 * these once and awhile.
1224 			 * Its harmless, just ignore it and move on.
1225 			 */
1226 			jsm_dbg(INTR, &brd->pci_dev,
1227 				"%s:%d Unknown Interrupt type: %x\n",
1228 				__FILE__, __LINE__, type);
1229 			continue;
1230 		}
1231 	}
1232 
1233 	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1234 
1235 	jsm_dbg(INTR, &brd->pci_dev, "finish\n");
1236 	return IRQ_HANDLED;
1237 }
1238 
1239 /*
1240  * Neo specific way of turning off the receiver.
1241  * Used as a way to enforce queue flow control when in
1242  * hardware flow control mode.
1243  */
1244 static void neo_disable_receiver(struct jsm_channel *ch)
1245 {
1246 	u8 tmp = readb(&ch->ch_neo_uart->ier);
1247 	tmp &= ~(UART_IER_RDI);
1248 	writeb(tmp, &ch->ch_neo_uart->ier);
1249 
1250 	/* flush write operation */
1251 	neo_pci_posting_flush(ch->ch_bd);
1252 }
1253 
1254 
1255 /*
1256  * Neo specific way of turning on the receiver.
1257  * Used as a way to un-enforce queue flow control when in
1258  * hardware flow control mode.
1259  */
1260 static void neo_enable_receiver(struct jsm_channel *ch)
1261 {
1262 	u8 tmp = readb(&ch->ch_neo_uart->ier);
1263 	tmp |= (UART_IER_RDI);
1264 	writeb(tmp, &ch->ch_neo_uart->ier);
1265 
1266 	/* flush write operation */
1267 	neo_pci_posting_flush(ch->ch_bd);
1268 }
1269 
1270 static void neo_send_start_character(struct jsm_channel *ch)
1271 {
1272 	if (!ch)
1273 		return;
1274 
1275 	if (ch->ch_startc != __DISABLED_CHAR) {
1276 		ch->ch_xon_sends++;
1277 		writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
1278 
1279 		/* flush write operation */
1280 		neo_pci_posting_flush(ch->ch_bd);
1281 	}
1282 }
1283 
1284 static void neo_send_stop_character(struct jsm_channel *ch)
1285 {
1286 	if (!ch)
1287 		return;
1288 
1289 	if (ch->ch_stopc != __DISABLED_CHAR) {
1290 		ch->ch_xoff_sends++;
1291 		writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
1292 
1293 		/* flush write operation */
1294 		neo_pci_posting_flush(ch->ch_bd);
1295 	}
1296 }
1297 
1298 /*
1299  * neo_uart_init
1300  */
1301 static void neo_uart_init(struct jsm_channel *ch)
1302 {
1303 	writeb(0, &ch->ch_neo_uart->ier);
1304 	writeb(0, &ch->ch_neo_uart->efr);
1305 	writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
1306 
1307 	/* Clear out UART and FIFO */
1308 	readb(&ch->ch_neo_uart->txrx);
1309 	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1310 	readb(&ch->ch_neo_uart->lsr);
1311 	readb(&ch->ch_neo_uart->msr);
1312 
1313 	ch->ch_flags |= CH_FIFO_ENABLED;
1314 
1315 	/* Assert any signals we want up */
1316 	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
1317 }
1318 
1319 /*
1320  * Make the UART completely turn off.
1321  */
1322 static void neo_uart_off(struct jsm_channel *ch)
1323 {
1324 	/* Turn off UART enhanced bits */
1325 	writeb(0, &ch->ch_neo_uart->efr);
1326 
1327 	/* Stop all interrupts from occurring. */
1328 	writeb(0, &ch->ch_neo_uart->ier);
1329 }
1330 
1331 static u32 neo_get_uart_bytes_left(struct jsm_channel *ch)
1332 {
1333 	u8 left = 0;
1334 	u8 lsr = readb(&ch->ch_neo_uart->lsr);
1335 
1336 	/* We must cache the LSR as some of the bits get reset once read... */
1337 	ch->ch_cached_lsr |= lsr;
1338 
1339 	/* Determine whether the Transmitter is empty or not */
1340 	if (!(lsr & UART_LSR_TEMT))
1341 		left = 1;
1342 	else {
1343 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1344 		left = 0;
1345 	}
1346 
1347 	return left;
1348 }
1349 
1350 /* Channel lock MUST be held by the calling function! */
1351 static void neo_send_break(struct jsm_channel *ch)
1352 {
1353 	/*
1354 	 * Set the time we should stop sending the break.
1355 	 * If we are already sending a break, toss away the existing
1356 	 * time to stop, and use this new value instead.
1357 	 */
1358 
1359 	/* Tell the UART to start sending the break */
1360 	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
1361 		u8 temp = readb(&ch->ch_neo_uart->lcr);
1362 		writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1363 		ch->ch_flags |= (CH_BREAK_SENDING);
1364 
1365 		/* flush write operation */
1366 		neo_pci_posting_flush(ch->ch_bd);
1367 	}
1368 }
1369 
1370 /*
1371  * neo_send_immediate_char.
1372  *
1373  * Sends a specific character as soon as possible to the UART,
1374  * jumping over any bytes that might be in the write queue.
1375  *
1376  * The channel lock MUST be held by the calling function.
1377  */
1378 static void neo_send_immediate_char(struct jsm_channel *ch, unsigned char c)
1379 {
1380 	if (!ch)
1381 		return;
1382 
1383 	writeb(c, &ch->ch_neo_uart->txrx);
1384 
1385 	/* flush write operation */
1386 	neo_pci_posting_flush(ch->ch_bd);
1387 }
1388 
1389 struct board_ops jsm_neo_ops = {
1390 	.intr				= neo_intr,
1391 	.uart_init			= neo_uart_init,
1392 	.uart_off			= neo_uart_off,
1393 	.param				= neo_param,
1394 	.assert_modem_signals		= neo_assert_modem_signals,
1395 	.flush_uart_write		= neo_flush_uart_write,
1396 	.flush_uart_read		= neo_flush_uart_read,
1397 	.disable_receiver		= neo_disable_receiver,
1398 	.enable_receiver		= neo_enable_receiver,
1399 	.send_break			= neo_send_break,
1400 	.clear_break			= neo_clear_break,
1401 	.send_start_character		= neo_send_start_character,
1402 	.send_stop_character		= neo_send_stop_character,
1403 	.copy_data_from_queue_to_uart	= neo_copy_data_from_queue_to_uart,
1404 	.get_uart_bytes_left		= neo_get_uart_bytes_left,
1405 	.send_immediate_char		= neo_send_immediate_char
1406 };
1407