xref: /openbmc/linux/drivers/tty/serial/jsm/jsm_neo.c (revision 9a29f5fc)
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 	qleft = tail - head - 1;
295 	if (qleft < 0)
296 		qleft += RQUEUEMASK + 1;
297 
298 	/*
299 	 * If the UART is not in FIFO mode, force the FIFO copy to
300 	 * NOT be run, by setting total to 0.
301 	 *
302 	 * On the other hand, if the UART IS in FIFO mode, then ask
303 	 * the UART to give us an approximation of data it has RX'ed.
304 	 */
305 	if (!(ch->ch_flags & CH_FIFO_ENABLED))
306 		total = 0;
307 	else {
308 		total = readb(&ch->ch_neo_uart->rfifo);
309 
310 		/*
311 		 * EXAR chip bug - RX FIFO COUNT - Fudge factor.
312 		 *
313 		 * This resolves a problem/bug with the Exar chip that sometimes
314 		 * returns a bogus value in the rfifo register.
315 		 * The count can be any where from 0-3 bytes "off".
316 		 * Bizarre, but true.
317 		 */
318 		total -= 3;
319 	}
320 
321 	/*
322 	 * Finally, bound the copy to make sure we don't overflow
323 	 * our own queue...
324 	 * The byte by byte copy loop below this loop this will
325 	 * deal with the queue overflow possibility.
326 	 */
327 	total = min(total, qleft);
328 
329 	while (total > 0) {
330 		/*
331 		 * Grab the linestatus register, we need to check
332 		 * to see if there are any errors in the FIFO.
333 		 */
334 		linestatus = readb(&ch->ch_neo_uart->lsr);
335 
336 		/*
337 		 * Break out if there is a FIFO error somewhere.
338 		 * This will allow us to go byte by byte down below,
339 		 * finding the exact location of the error.
340 		 */
341 		if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
342 			break;
343 
344 		/* Make sure we don't go over the end of our queue */
345 		n = min(((u32) total), (RQUEUESIZE - (u32) head));
346 
347 		/*
348 		 * Cut down n even further if needed, this is to fix
349 		 * a problem with memcpy_fromio() with the Neo on the
350 		 * IBM pSeries platform.
351 		 * 15 bytes max appears to be the magic number.
352 		 */
353 		n = min((u32) n, (u32) 12);
354 
355 		/*
356 		 * Since we are grabbing the linestatus register, which
357 		 * will reset some bits after our read, we need to ensure
358 		 * we don't miss our TX FIFO emptys.
359 		 */
360 		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
361 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
362 
363 		linestatus = 0;
364 
365 		/* Copy data from uart to the queue */
366 		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
367 		/*
368 		 * Since RX_FIFO_DATA_ERROR was 0, we are guaranteed
369 		 * that all the data currently in the FIFO is free of
370 		 * breaks and parity/frame/orun errors.
371 		 */
372 		memset(ch->ch_equeue + head, 0, n);
373 
374 		/* Add to and flip head if needed */
375 		head = (head + n) & RQUEUEMASK;
376 		total -= n;
377 		qleft -= n;
378 		ch->ch_rxcount += n;
379 	}
380 
381 	/*
382 	 * Create a mask to determine whether we should
383 	 * insert the character (if any) into our queue.
384 	 */
385 	if (ch->ch_c_iflag & IGNBRK)
386 		error_mask |= UART_LSR_BI;
387 
388 	/*
389 	 * Now cleanup any leftover bytes still in the UART.
390 	 * Also deal with any possible queue overflow here as well.
391 	 */
392 	while (1) {
393 
394 		/*
395 		 * Its possible we have a linestatus from the loop above
396 		 * this, so we "OR" on any extra bits.
397 		 */
398 		linestatus |= readb(&ch->ch_neo_uart->lsr);
399 
400 		/*
401 		 * If the chip tells us there is no more data pending to
402 		 * be read, we can then leave.
403 		 * But before we do, cache the linestatus, just in case.
404 		 */
405 		if (!(linestatus & UART_LSR_DR)) {
406 			ch->ch_cached_lsr = linestatus;
407 			break;
408 		}
409 
410 		/* No need to store this bit */
411 		linestatus &= ~UART_LSR_DR;
412 
413 		/*
414 		 * Since we are grabbing the linestatus register, which
415 		 * will reset some bits after our read, we need to ensure
416 		 * we don't miss our TX FIFO emptys.
417 		 */
418 		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
419 			linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
420 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
421 		}
422 
423 		/*
424 		 * Discard character if we are ignoring the error mask.
425 		 */
426 		if (linestatus & error_mask) {
427 			u8 discard;
428 			linestatus = 0;
429 			memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
430 			continue;
431 		}
432 
433 		/*
434 		 * If our queue is full, we have no choice but to drop some data.
435 		 * The assumption is that HWFLOW or SWFLOW should have stopped
436 		 * things way way before we got to this point.
437 		 *
438 		 * I decided that I wanted to ditch the oldest data first,
439 		 * I hope thats okay with everyone? Yes? Good.
440 		 */
441 		while (qleft < 1) {
442 			jsm_dbg(READ, &ch->ch_bd->pci_dev,
443 				"Queue full, dropping DATA:%x LSR:%x\n",
444 				ch->ch_rqueue[tail], ch->ch_equeue[tail]);
445 
446 			ch->ch_r_tail = tail = (tail + 1) & RQUEUEMASK;
447 			ch->ch_err_overrun++;
448 			qleft++;
449 		}
450 
451 		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
452 		ch->ch_equeue[head] = (u8) linestatus;
453 
454 		jsm_dbg(READ, &ch->ch_bd->pci_dev, "DATA/LSR pair: %x %x\n",
455 			ch->ch_rqueue[head], ch->ch_equeue[head]);
456 
457 		/* Ditch any remaining linestatus value. */
458 		linestatus = 0;
459 
460 		/* Add to and flip head if needed */
461 		head = (head + 1) & RQUEUEMASK;
462 
463 		qleft--;
464 		ch->ch_rxcount++;
465 	}
466 
467 	/*
468 	 * Write new final heads to channel structure.
469 	 */
470 	ch->ch_r_head = head & RQUEUEMASK;
471 	ch->ch_e_head = head & EQUEUEMASK;
472 	jsm_input(ch);
473 }
474 
475 static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
476 {
477 	u16 head;
478 	u16 tail;
479 	int n;
480 	int s;
481 	int qlen;
482 	u32 len_written = 0;
483 	struct circ_buf *circ;
484 
485 	if (!ch)
486 		return;
487 
488 	circ = &ch->uart_port.state->xmit;
489 
490 	/* No data to write to the UART */
491 	if (uart_circ_empty(circ))
492 		return;
493 
494 	/* If port is "stopped", don't send any data to the UART */
495 	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
496 		return;
497 	/*
498 	 * If FIFOs are disabled. Send data directly to txrx register
499 	 */
500 	if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
501 		u8 lsrbits = readb(&ch->ch_neo_uart->lsr);
502 
503 		ch->ch_cached_lsr |= lsrbits;
504 		if (ch->ch_cached_lsr & UART_LSR_THRE) {
505 			ch->ch_cached_lsr &= ~(UART_LSR_THRE);
506 
507 			writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
508 			jsm_dbg(WRITE, &ch->ch_bd->pci_dev,
509 				"Tx data: %x\n", circ->buf[circ->tail]);
510 			circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
511 			ch->ch_txcount++;
512 		}
513 		return;
514 	}
515 
516 	/*
517 	 * We have to do it this way, because of the EXAR TXFIFO count bug.
518 	 */
519 	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
520 		return;
521 
522 	n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
523 
524 	/* cache head and tail of queue */
525 	head = circ->head & (UART_XMIT_SIZE - 1);
526 	tail = circ->tail & (UART_XMIT_SIZE - 1);
527 	qlen = uart_circ_chars_pending(circ);
528 
529 	/* Find minimum of the FIFO space, versus queue length */
530 	n = min(n, qlen);
531 
532 	while (n > 0) {
533 
534 		s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
535 		s = min(s, n);
536 
537 		if (s <= 0)
538 			break;
539 
540 		memcpy_toio(&ch->ch_neo_uart->txrxburst, circ->buf + tail, s);
541 		/* Add and flip queue if needed */
542 		tail = (tail + s) & (UART_XMIT_SIZE - 1);
543 		n -= s;
544 		ch->ch_txcount += s;
545 		len_written += s;
546 	}
547 
548 	/* Update the final tail */
549 	circ->tail = tail & (UART_XMIT_SIZE - 1);
550 
551 	if (len_written >= ch->ch_t_tlevel)
552 		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
553 
554 	if (uart_circ_empty(circ))
555 		uart_write_wakeup(&ch->uart_port);
556 }
557 
558 static void neo_parse_modem(struct jsm_channel *ch, u8 signals)
559 {
560 	u8 msignals = signals;
561 
562 	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
563 		"neo_parse_modem: port: %d msignals: %x\n",
564 		ch->ch_portnum, msignals);
565 
566 	/* Scrub off lower bits. They signify delta's, which I don't care about */
567 	/* Keep DDCD and DDSR though */
568 	msignals &= 0xf8;
569 
570 	if (msignals & UART_MSR_DDCD)
571 		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
572 	if (msignals & UART_MSR_DDSR)
573 		uart_handle_cts_change(&ch->uart_port, msignals & UART_MSR_CTS);
574 	if (msignals & UART_MSR_DCD)
575 		ch->ch_mistat |= UART_MSR_DCD;
576 	else
577 		ch->ch_mistat &= ~UART_MSR_DCD;
578 
579 	if (msignals & UART_MSR_DSR)
580 		ch->ch_mistat |= UART_MSR_DSR;
581 	else
582 		ch->ch_mistat &= ~UART_MSR_DSR;
583 
584 	if (msignals & UART_MSR_RI)
585 		ch->ch_mistat |= UART_MSR_RI;
586 	else
587 		ch->ch_mistat &= ~UART_MSR_RI;
588 
589 	if (msignals & UART_MSR_CTS)
590 		ch->ch_mistat |= UART_MSR_CTS;
591 	else
592 		ch->ch_mistat &= ~UART_MSR_CTS;
593 
594 	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
595 		"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
596 		ch->ch_portnum,
597 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
598 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
599 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
600 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
601 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
602 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
603 }
604 
605 /* Make the UART raise any of the output signals we want up */
606 static void neo_assert_modem_signals(struct jsm_channel *ch)
607 {
608 	if (!ch)
609 		return;
610 
611 	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
612 
613 	/* flush write operation */
614 	neo_pci_posting_flush(ch->ch_bd);
615 }
616 
617 /*
618  * Flush the WRITE FIFO on the Neo.
619  *
620  * NOTE: Channel lock MUST be held before calling this function!
621  */
622 static void neo_flush_uart_write(struct jsm_channel *ch)
623 {
624 	u8 tmp = 0;
625 	int i = 0;
626 
627 	if (!ch)
628 		return;
629 
630 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
631 
632 	for (i = 0; i < 10; i++) {
633 
634 		/* Check to see if the UART feels it completely flushed the FIFO. */
635 		tmp = readb(&ch->ch_neo_uart->isr_fcr);
636 		if (tmp & UART_FCR_CLEAR_XMIT) {
637 			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
638 				"Still flushing TX UART... i: %d\n", i);
639 			udelay(10);
640 		}
641 		else
642 			break;
643 	}
644 
645 	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
646 }
647 
648 
649 /*
650  * Flush the READ FIFO on the Neo.
651  *
652  * NOTE: Channel lock MUST be held before calling this function!
653  */
654 static void neo_flush_uart_read(struct jsm_channel *ch)
655 {
656 	u8 tmp = 0;
657 	int i = 0;
658 
659 	if (!ch)
660 		return;
661 
662 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
663 
664 	for (i = 0; i < 10; i++) {
665 
666 		/* Check to see if the UART feels it completely flushed the FIFO. */
667 		tmp = readb(&ch->ch_neo_uart->isr_fcr);
668 		if (tmp & 2) {
669 			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
670 				"Still flushing RX UART... i: %d\n", i);
671 			udelay(10);
672 		}
673 		else
674 			break;
675 	}
676 }
677 
678 /*
679  * No locks are assumed to be held when calling this function.
680  */
681 static void neo_clear_break(struct jsm_channel *ch)
682 {
683 	unsigned long lock_flags;
684 
685 	spin_lock_irqsave(&ch->ch_lock, lock_flags);
686 
687 	/* Turn break off, and unset some variables */
688 	if (ch->ch_flags & CH_BREAK_SENDING) {
689 		u8 temp = readb(&ch->ch_neo_uart->lcr);
690 		writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
691 
692 		ch->ch_flags &= ~(CH_BREAK_SENDING);
693 		jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
694 			"clear break Finishing UART_LCR_SBC! finished: %lx\n",
695 			jiffies);
696 
697 		/* flush write operation */
698 		neo_pci_posting_flush(ch->ch_bd);
699 	}
700 	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
701 }
702 
703 /*
704  * Parse the ISR register.
705  */
706 static void neo_parse_isr(struct jsm_board *brd, u32 port)
707 {
708 	struct jsm_channel *ch;
709 	u8 isr;
710 	u8 cause;
711 	unsigned long lock_flags;
712 
713 	if (!brd)
714 		return;
715 
716 	if (port >= brd->maxports)
717 		return;
718 
719 	ch = brd->channels[port];
720 	if (!ch)
721 		return;
722 
723 	/* Here we try to figure out what caused the interrupt to happen */
724 	while (1) {
725 
726 		isr = readb(&ch->ch_neo_uart->isr_fcr);
727 
728 		/* Bail if no pending interrupt */
729 		if (isr & UART_IIR_NO_INT)
730 			break;
731 
732 		/*
733 		 * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
734 		 */
735 		isr &= ~(UART_17158_IIR_FIFO_ENABLED);
736 
737 		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d isr: %x\n",
738 			__FILE__, __LINE__, isr);
739 
740 		if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
741 			/* Read data from uart -> queue */
742 			neo_copy_data_from_uart_to_queue(ch);
743 
744 			/* Call our tty layer to enforce queue flow control if needed. */
745 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
746 			jsm_check_queue_flow_control(ch);
747 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
748 		}
749 
750 		if (isr & UART_IIR_THRI) {
751 			/* Transfer data (if any) from Write Queue -> UART. */
752 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
753 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
754 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
755 			neo_copy_data_from_queue_to_uart(ch);
756 		}
757 
758 		if (isr & UART_17158_IIR_XONXOFF) {
759 			cause = readb(&ch->ch_neo_uart->xoffchar1);
760 
761 			jsm_dbg(INTR, &ch->ch_bd->pci_dev,
762 				"Port %d. Got ISR_XONXOFF: cause:%x\n",
763 				port, cause);
764 
765 			/*
766 			 * Since the UART detected either an XON or
767 			 * XOFF match, we need to figure out which
768 			 * one it was, so we can suspend or resume data flow.
769 			 */
770 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
771 			if (cause == UART_17158_XON_DETECT) {
772 				/* Is output stopped right now, if so, resume it */
773 				if (brd->channels[port]->ch_flags & CH_STOP) {
774 					ch->ch_flags &= ~(CH_STOP);
775 				}
776 				jsm_dbg(INTR, &ch->ch_bd->pci_dev,
777 					"Port %d. XON detected in incoming data\n",
778 					port);
779 			}
780 			else if (cause == UART_17158_XOFF_DETECT) {
781 				if (!(brd->channels[port]->ch_flags & CH_STOP)) {
782 					ch->ch_flags |= CH_STOP;
783 					jsm_dbg(INTR, &ch->ch_bd->pci_dev,
784 						"Setting CH_STOP\n");
785 				}
786 				jsm_dbg(INTR, &ch->ch_bd->pci_dev,
787 					"Port: %d. XOFF detected in incoming data\n",
788 					port);
789 			}
790 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
791 		}
792 
793 		if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
794 			/*
795 			 * If we get here, this means the hardware is doing auto flow control.
796 			 * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
797 			 */
798 			cause = readb(&ch->ch_neo_uart->mcr);
799 
800 			/* Which pin is doing auto flow? RTS or DTR? */
801 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
802 			if ((cause & 0x4) == 0) {
803 				if (cause & UART_MCR_RTS)
804 					ch->ch_mostat |= UART_MCR_RTS;
805 				else
806 					ch->ch_mostat &= ~(UART_MCR_RTS);
807 			} else {
808 				if (cause & UART_MCR_DTR)
809 					ch->ch_mostat |= UART_MCR_DTR;
810 				else
811 					ch->ch_mostat &= ~(UART_MCR_DTR);
812 			}
813 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
814 		}
815 
816 		/* Parse any modem signal changes */
817 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
818 			"MOD_STAT: sending to parse_modem_sigs\n");
819 		spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
820 		neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
821 		spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
822 	}
823 }
824 
825 static inline void neo_parse_lsr(struct jsm_board *brd, u32 port)
826 {
827 	struct jsm_channel *ch;
828 	int linestatus;
829 	unsigned long lock_flags;
830 
831 	if (!brd)
832 		return;
833 
834 	if (port >= brd->maxports)
835 		return;
836 
837 	ch = brd->channels[port];
838 	if (!ch)
839 		return;
840 
841 	linestatus = readb(&ch->ch_neo_uart->lsr);
842 
843 	jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d port: %d linestatus: %x\n",
844 		__FILE__, __LINE__, port, linestatus);
845 
846 	ch->ch_cached_lsr |= linestatus;
847 
848 	if (ch->ch_cached_lsr & UART_LSR_DR) {
849 		/* Read data from uart -> queue */
850 		neo_copy_data_from_uart_to_queue(ch);
851 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
852 		jsm_check_queue_flow_control(ch);
853 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
854 	}
855 
856 	/*
857 	 * This is a special flag. It indicates that at least 1
858 	 * RX error (parity, framing, or break) has happened.
859 	 * Mark this in our struct, which will tell me that I have
860 	 *to do the special RX+LSR read for this FIFO load.
861 	 */
862 	if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
863 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
864 			"%s:%d Port: %d Got an RX error, need to parse LSR\n",
865 			__FILE__, __LINE__, port);
866 
867 	/*
868 	 * The next 3 tests should *NOT* happen, as the above test
869 	 * should encapsulate all 3... At least, thats what Exar says.
870 	 */
871 
872 	if (linestatus & UART_LSR_PE) {
873 		ch->ch_err_parity++;
874 		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. PAR ERR!\n",
875 			__FILE__, __LINE__, port);
876 	}
877 
878 	if (linestatus & UART_LSR_FE) {
879 		ch->ch_err_frame++;
880 		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. FRM ERR!\n",
881 			__FILE__, __LINE__, port);
882 	}
883 
884 	if (linestatus & UART_LSR_BI) {
885 		ch->ch_err_break++;
886 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
887 			"%s:%d Port: %d. BRK INTR!\n",
888 			__FILE__, __LINE__, port);
889 	}
890 
891 	if (linestatus & UART_LSR_OE) {
892 		/*
893 		 * Rx Oruns. Exar says that an orun will NOT corrupt
894 		 * the FIFO. It will just replace the holding register
895 		 * with this new data byte. So basically just ignore this.
896 		 * Probably we should eventually have an orun stat in our driver...
897 		 */
898 		ch->ch_err_overrun++;
899 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
900 			"%s:%d Port: %d. Rx Overrun!\n",
901 			__FILE__, __LINE__, port);
902 	}
903 
904 	if (linestatus & UART_LSR_THRE) {
905 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
906 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
907 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
908 
909 		/* Transfer data (if any) from Write Queue -> UART. */
910 		neo_copy_data_from_queue_to_uart(ch);
911 	}
912 	else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
913 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
914 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
915 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
916 
917 		/* Transfer data (if any) from Write Queue -> UART. */
918 		neo_copy_data_from_queue_to_uart(ch);
919 	}
920 }
921 
922 /*
923  * neo_param()
924  * Send any/all changes to the line to the UART.
925  */
926 static void neo_param(struct jsm_channel *ch)
927 {
928 	u8 lcr = 0;
929 	u8 uart_lcr, ier;
930 	u32 baud;
931 	int quot;
932 	struct jsm_board *bd;
933 
934 	bd = ch->ch_bd;
935 	if (!bd)
936 		return;
937 
938 	/*
939 	 * If baud rate is zero, flush queues, and set mval to drop DTR.
940 	 */
941 	if ((ch->ch_c_cflag & CBAUD) == B0) {
942 		ch->ch_r_head = ch->ch_r_tail = 0;
943 		ch->ch_e_head = ch->ch_e_tail = 0;
944 
945 		neo_flush_uart_write(ch);
946 		neo_flush_uart_read(ch);
947 
948 		ch->ch_flags |= (CH_BAUD0);
949 		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
950 		neo_assert_modem_signals(ch);
951 		return;
952 
953 	} else {
954 		int i;
955 		unsigned int cflag;
956 		static struct {
957 			unsigned int rate;
958 			unsigned int cflag;
959 		} baud_rates[] = {
960 			{ 921600, B921600 },
961 			{ 460800, B460800 },
962 			{ 230400, B230400 },
963 			{ 115200, B115200 },
964 			{  57600, B57600  },
965 			{  38400, B38400  },
966 			{  19200, B19200  },
967 			{   9600, B9600   },
968 			{   4800, B4800   },
969 			{   2400, B2400   },
970 			{   1200, B1200   },
971 			{    600, B600    },
972 			{    300, B300    },
973 			{    200, B200    },
974 			{    150, B150    },
975 			{    134, B134    },
976 			{    110, B110    },
977 			{     75, B75     },
978 			{     50, B50     },
979 		};
980 
981 		cflag = C_BAUD(ch->uart_port.state->port.tty);
982 		baud = 9600;
983 		for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
984 			if (baud_rates[i].cflag == cflag) {
985 				baud = baud_rates[i].rate;
986 				break;
987 			}
988 		}
989 
990 		if (ch->ch_flags & CH_BAUD0)
991 			ch->ch_flags &= ~(CH_BAUD0);
992 	}
993 
994 	if (ch->ch_c_cflag & PARENB)
995 		lcr |= UART_LCR_PARITY;
996 
997 	if (!(ch->ch_c_cflag & PARODD))
998 		lcr |= UART_LCR_EPAR;
999 
1000 	if (ch->ch_c_cflag & CMSPAR)
1001 		lcr |= UART_LCR_SPAR;
1002 
1003 	if (ch->ch_c_cflag & CSTOPB)
1004 		lcr |= UART_LCR_STOP;
1005 
1006 	lcr |= UART_LCR_WLEN(tty_get_char_size(ch->ch_c_cflag));
1007 
1008 	ier = readb(&ch->ch_neo_uart->ier);
1009 	uart_lcr = readb(&ch->ch_neo_uart->lcr);
1010 
1011 	quot = ch->ch_bd->bd_dividend / baud;
1012 
1013 	if (quot != 0) {
1014 		writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
1015 		writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
1016 		writeb((quot >> 8), &ch->ch_neo_uart->ier);
1017 		writeb(lcr, &ch->ch_neo_uart->lcr);
1018 	}
1019 
1020 	if (uart_lcr != lcr)
1021 		writeb(lcr, &ch->ch_neo_uart->lcr);
1022 
1023 	if (ch->ch_c_cflag & CREAD)
1024 		ier |= (UART_IER_RDI | UART_IER_RLSI);
1025 
1026 	ier |= (UART_IER_THRI | UART_IER_MSI);
1027 
1028 	writeb(ier, &ch->ch_neo_uart->ier);
1029 
1030 	/* Set new start/stop chars */
1031 	neo_set_new_start_stop_chars(ch);
1032 
1033 	if (ch->ch_c_cflag & CRTSCTS)
1034 		neo_set_cts_flow_control(ch);
1035 	else if (ch->ch_c_iflag & IXON) {
1036 		/* If start/stop is set to disable, then we should disable flow control */
1037 		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1038 			neo_set_no_output_flow_control(ch);
1039 		else
1040 			neo_set_ixon_flow_control(ch);
1041 	}
1042 	else
1043 		neo_set_no_output_flow_control(ch);
1044 
1045 	if (ch->ch_c_cflag & CRTSCTS)
1046 		neo_set_rts_flow_control(ch);
1047 	else if (ch->ch_c_iflag & IXOFF) {
1048 		/* If start/stop is set to disable, then we should disable flow control */
1049 		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1050 			neo_set_no_input_flow_control(ch);
1051 		else
1052 			neo_set_ixoff_flow_control(ch);
1053 	}
1054 	else
1055 		neo_set_no_input_flow_control(ch);
1056 	/*
1057 	 * Adjust the RX FIFO Trigger level if baud is less than 9600.
1058 	 * Not exactly elegant, but this is needed because of the Exar chip's
1059 	 * delay on firing off the RX FIFO interrupt on slower baud rates.
1060 	 */
1061 	if (baud < 9600) {
1062 		writeb(1, &ch->ch_neo_uart->rfifo);
1063 		ch->ch_r_tlevel = 1;
1064 	}
1065 
1066 	neo_assert_modem_signals(ch);
1067 
1068 	/* Get current status of the modem signals now */
1069 	neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
1070 	return;
1071 }
1072 
1073 /*
1074  * jsm_neo_intr()
1075  *
1076  * Neo specific interrupt handler.
1077  */
1078 static irqreturn_t neo_intr(int irq, void *voidbrd)
1079 {
1080 	struct jsm_board *brd = voidbrd;
1081 	struct jsm_channel *ch;
1082 	int port = 0;
1083 	int type = 0;
1084 	int current_port;
1085 	u32 tmp;
1086 	u32 uart_poll;
1087 	unsigned long lock_flags;
1088 	unsigned long lock_flags2;
1089 	int outofloop_count = 0;
1090 
1091 	/* Lock out the slow poller from running on this board. */
1092 	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
1093 
1094 	/*
1095 	 * Read in "extended" IRQ information from the 32bit Neo register.
1096 	 * Bits 0-7: What port triggered the interrupt.
1097 	 * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
1098 	 */
1099 	uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
1100 
1101 	jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
1102 		__FILE__, __LINE__, uart_poll);
1103 
1104 	if (!uart_poll) {
1105 		jsm_dbg(INTR, &brd->pci_dev,
1106 			"Kernel interrupted to me, but no pending interrupts...\n");
1107 		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1108 		return IRQ_NONE;
1109 	}
1110 
1111 	/* At this point, we have at least SOMETHING to service, dig further... */
1112 
1113 	current_port = 0;
1114 
1115 	/* Loop on each port */
1116 	while (((uart_poll & 0xff) != 0) && (outofloop_count < 0xff)){
1117 
1118 		tmp = uart_poll;
1119 		outofloop_count++;
1120 
1121 		/* Check current port to see if it has interrupt pending */
1122 		if ((tmp & jsm_offset_table[current_port]) != 0) {
1123 			port = current_port;
1124 			type = tmp >> (8 + (port * 3));
1125 			type &= 0x7;
1126 		} else {
1127 			current_port++;
1128 			continue;
1129 		}
1130 
1131 		jsm_dbg(INTR, &brd->pci_dev, "%s:%d port: %x type: %x\n",
1132 			__FILE__, __LINE__, port, type);
1133 
1134 		/* Remove this port + type from uart_poll */
1135 		uart_poll &= ~(jsm_offset_table[port]);
1136 
1137 		if (!type) {
1138 			/* If no type, just ignore it, and move onto next port */
1139 			jsm_dbg(INTR, &brd->pci_dev,
1140 				"Interrupt with no type! port: %d\n", port);
1141 			continue;
1142 		}
1143 
1144 		/* Switch on type of interrupt we have */
1145 		switch (type) {
1146 
1147 		case UART_17158_RXRDY_TIMEOUT:
1148 			/*
1149 			 * RXRDY Time-out is cleared by reading data in the
1150 			* RX FIFO until it falls below the trigger level.
1151 			 */
1152 
1153 			/* Verify the port is in range. */
1154 			if (port >= brd->nasync)
1155 				continue;
1156 
1157 			ch = brd->channels[port];
1158 			if (!ch)
1159 				continue;
1160 
1161 			neo_copy_data_from_uart_to_queue(ch);
1162 
1163 			/* Call our tty layer to enforce queue flow control if needed. */
1164 			spin_lock_irqsave(&ch->ch_lock, lock_flags2);
1165 			jsm_check_queue_flow_control(ch);
1166 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags2);
1167 
1168 			continue;
1169 
1170 		case UART_17158_RX_LINE_STATUS:
1171 			/*
1172 			 * RXRDY and RX LINE Status (logic OR of LSR[4:1])
1173 			 */
1174 			neo_parse_lsr(brd, port);
1175 			continue;
1176 
1177 		case UART_17158_TXRDY:
1178 			/*
1179 			 * TXRDY interrupt clears after reading ISR register for the UART channel.
1180 			 */
1181 
1182 			/*
1183 			 * Yes, this is odd...
1184 			 * Why would I check EVERY possibility of type of
1185 			 * interrupt, when we know its TXRDY???
1186 			 * Becuz for some reason, even tho we got triggered for TXRDY,
1187 			 * it seems to be occasionally wrong. Instead of TX, which
1188 			 * it should be, I was getting things like RXDY too. Weird.
1189 			 */
1190 			neo_parse_isr(brd, port);
1191 			continue;
1192 
1193 		case UART_17158_MSR:
1194 			/*
1195 			 * MSR or flow control was seen.
1196 			 */
1197 			neo_parse_isr(brd, port);
1198 			continue;
1199 
1200 		default:
1201 			/*
1202 			 * The UART triggered us with a bogus interrupt type.
1203 			 * It appears the Exar chip, when REALLY bogged down, will throw
1204 			 * these once and awhile.
1205 			 * Its harmless, just ignore it and move on.
1206 			 */
1207 			jsm_dbg(INTR, &brd->pci_dev,
1208 				"%s:%d Unknown Interrupt type: %x\n",
1209 				__FILE__, __LINE__, type);
1210 			continue;
1211 		}
1212 	}
1213 
1214 	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1215 
1216 	jsm_dbg(INTR, &brd->pci_dev, "finish\n");
1217 	return IRQ_HANDLED;
1218 }
1219 
1220 /*
1221  * Neo specific way of turning off the receiver.
1222  * Used as a way to enforce queue flow control when in
1223  * hardware flow control mode.
1224  */
1225 static void neo_disable_receiver(struct jsm_channel *ch)
1226 {
1227 	u8 tmp = readb(&ch->ch_neo_uart->ier);
1228 	tmp &= ~(UART_IER_RDI);
1229 	writeb(tmp, &ch->ch_neo_uart->ier);
1230 
1231 	/* flush write operation */
1232 	neo_pci_posting_flush(ch->ch_bd);
1233 }
1234 
1235 
1236 /*
1237  * Neo specific way of turning on the receiver.
1238  * Used as a way to un-enforce queue flow control when in
1239  * hardware flow control mode.
1240  */
1241 static void neo_enable_receiver(struct jsm_channel *ch)
1242 {
1243 	u8 tmp = readb(&ch->ch_neo_uart->ier);
1244 	tmp |= (UART_IER_RDI);
1245 	writeb(tmp, &ch->ch_neo_uart->ier);
1246 
1247 	/* flush write operation */
1248 	neo_pci_posting_flush(ch->ch_bd);
1249 }
1250 
1251 static void neo_send_start_character(struct jsm_channel *ch)
1252 {
1253 	if (!ch)
1254 		return;
1255 
1256 	if (ch->ch_startc != __DISABLED_CHAR) {
1257 		ch->ch_xon_sends++;
1258 		writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
1259 
1260 		/* flush write operation */
1261 		neo_pci_posting_flush(ch->ch_bd);
1262 	}
1263 }
1264 
1265 static void neo_send_stop_character(struct jsm_channel *ch)
1266 {
1267 	if (!ch)
1268 		return;
1269 
1270 	if (ch->ch_stopc != __DISABLED_CHAR) {
1271 		ch->ch_xoff_sends++;
1272 		writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
1273 
1274 		/* flush write operation */
1275 		neo_pci_posting_flush(ch->ch_bd);
1276 	}
1277 }
1278 
1279 /*
1280  * neo_uart_init
1281  */
1282 static void neo_uart_init(struct jsm_channel *ch)
1283 {
1284 	writeb(0, &ch->ch_neo_uart->ier);
1285 	writeb(0, &ch->ch_neo_uart->efr);
1286 	writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
1287 
1288 	/* Clear out UART and FIFO */
1289 	readb(&ch->ch_neo_uart->txrx);
1290 	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1291 	readb(&ch->ch_neo_uart->lsr);
1292 	readb(&ch->ch_neo_uart->msr);
1293 
1294 	ch->ch_flags |= CH_FIFO_ENABLED;
1295 
1296 	/* Assert any signals we want up */
1297 	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
1298 }
1299 
1300 /*
1301  * Make the UART completely turn off.
1302  */
1303 static void neo_uart_off(struct jsm_channel *ch)
1304 {
1305 	/* Turn off UART enhanced bits */
1306 	writeb(0, &ch->ch_neo_uart->efr);
1307 
1308 	/* Stop all interrupts from occurring. */
1309 	writeb(0, &ch->ch_neo_uart->ier);
1310 }
1311 
1312 static u32 neo_get_uart_bytes_left(struct jsm_channel *ch)
1313 {
1314 	u8 left = 0;
1315 	u8 lsr = readb(&ch->ch_neo_uart->lsr);
1316 
1317 	/* We must cache the LSR as some of the bits get reset once read... */
1318 	ch->ch_cached_lsr |= lsr;
1319 
1320 	/* Determine whether the Transmitter is empty or not */
1321 	if (!(lsr & UART_LSR_TEMT))
1322 		left = 1;
1323 	else {
1324 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1325 		left = 0;
1326 	}
1327 
1328 	return left;
1329 }
1330 
1331 /* Channel lock MUST be held by the calling function! */
1332 static void neo_send_break(struct jsm_channel *ch)
1333 {
1334 	/*
1335 	 * Set the time we should stop sending the break.
1336 	 * If we are already sending a break, toss away the existing
1337 	 * time to stop, and use this new value instead.
1338 	 */
1339 
1340 	/* Tell the UART to start sending the break */
1341 	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
1342 		u8 temp = readb(&ch->ch_neo_uart->lcr);
1343 		writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1344 		ch->ch_flags |= (CH_BREAK_SENDING);
1345 
1346 		/* flush write operation */
1347 		neo_pci_posting_flush(ch->ch_bd);
1348 	}
1349 }
1350 
1351 /*
1352  * neo_send_immediate_char.
1353  *
1354  * Sends a specific character as soon as possible to the UART,
1355  * jumping over any bytes that might be in the write queue.
1356  *
1357  * The channel lock MUST be held by the calling function.
1358  */
1359 static void neo_send_immediate_char(struct jsm_channel *ch, unsigned char c)
1360 {
1361 	if (!ch)
1362 		return;
1363 
1364 	writeb(c, &ch->ch_neo_uart->txrx);
1365 
1366 	/* flush write operation */
1367 	neo_pci_posting_flush(ch->ch_bd);
1368 }
1369 
1370 struct board_ops jsm_neo_ops = {
1371 	.intr				= neo_intr,
1372 	.uart_init			= neo_uart_init,
1373 	.uart_off			= neo_uart_off,
1374 	.param				= neo_param,
1375 	.assert_modem_signals		= neo_assert_modem_signals,
1376 	.flush_uart_write		= neo_flush_uart_write,
1377 	.flush_uart_read		= neo_flush_uart_read,
1378 	.disable_receiver		= neo_disable_receiver,
1379 	.enable_receiver		= neo_enable_receiver,
1380 	.send_break			= neo_send_break,
1381 	.clear_break			= neo_clear_break,
1382 	.send_start_character		= neo_send_start_character,
1383 	.send_stop_character		= neo_send_stop_character,
1384 	.copy_data_from_queue_to_uart	= neo_copy_data_from_queue_to_uart,
1385 	.get_uart_bytes_left		= neo_get_uart_bytes_left,
1386 	.send_immediate_char		= neo_send_immediate_char
1387 };
1388