1 /************************************************************************
2  * Copyright 2003 Digi International (www.digi.com)
3  *
4  * Copyright (C) 2004 IBM Corporation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2, or (at your option)
9  * any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
13  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
14  * PURPOSE.  See the GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
19  * MA  02111-1307, USA.
20  *
21  * Contact Information:
22  * Scott H Kilau <Scott_Kilau@digi.com>
23  * Wendy Xiong   <wendyx@us.ibm.com>
24  *
25  ***********************************************************************/
26 #include <linux/delay.h>	/* For udelay */
27 #include <linux/serial_reg.h>	/* For the various UART offsets */
28 #include <linux/tty.h>
29 #include <linux/pci.h>
30 #include <asm/io.h>
31 
32 #include "jsm.h"		/* Driver main header file */
33 
34 static u32 jsm_offset_table[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
35 
36 /*
37  * This function allows calls to ensure that all outstanding
38  * PCI writes have been completed, by doing a PCI read against
39  * a non-destructive, read-only location on the Neo card.
40  *
41  * In this case, we are reading the DVID (Read-only Device Identification)
42  * value of the Neo card.
43  */
neo_pci_posting_flush(struct jsm_board * bd)44 static inline void neo_pci_posting_flush(struct jsm_board *bd)
45 {
46       readb(bd->re_map_membase + 0x8D);
47 }
48 
neo_set_cts_flow_control(struct jsm_channel * ch)49 static void neo_set_cts_flow_control(struct jsm_channel *ch)
50 {
51 	u8 ier, efr;
52 	ier = readb(&ch->ch_neo_uart->ier);
53 	efr = readb(&ch->ch_neo_uart->efr);
54 
55 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting CTSFLOW\n");
56 
57 	/* Turn on auto CTS flow control */
58 	ier |= (UART_17158_IER_CTSDSR);
59 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_CTSDSR);
60 
61 	/* Turn off auto Xon flow control */
62 	efr &= ~(UART_17158_EFR_IXON);
63 
64 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
65 	writeb(0, &ch->ch_neo_uart->efr);
66 
67 	/* Turn on UART enhanced bits */
68 	writeb(efr, &ch->ch_neo_uart->efr);
69 
70 	/* Turn on table D, with 8 char hi/low watermarks */
71 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
72 
73 	/* Feed the UART our trigger levels */
74 	writeb(8, &ch->ch_neo_uart->tfifo);
75 	ch->ch_t_tlevel = 8;
76 
77 	writeb(ier, &ch->ch_neo_uart->ier);
78 }
79 
neo_set_rts_flow_control(struct jsm_channel * ch)80 static void neo_set_rts_flow_control(struct jsm_channel *ch)
81 {
82 	u8 ier, efr;
83 	ier = readb(&ch->ch_neo_uart->ier);
84 	efr = readb(&ch->ch_neo_uart->efr);
85 
86 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting RTSFLOW\n");
87 
88 	/* Turn on auto RTS flow control */
89 	ier |= (UART_17158_IER_RTSDTR);
90 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_RTSDTR);
91 
92 	/* Turn off auto Xoff flow control */
93 	ier &= ~(UART_17158_IER_XOFF);
94 	efr &= ~(UART_17158_EFR_IXOFF);
95 
96 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
97 	writeb(0, &ch->ch_neo_uart->efr);
98 
99 	/* Turn on UART enhanced bits */
100 	writeb(efr, &ch->ch_neo_uart->efr);
101 
102 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
103 	ch->ch_r_watermark = 4;
104 
105 	writeb(56, &ch->ch_neo_uart->rfifo);
106 	ch->ch_r_tlevel = 56;
107 
108 	writeb(ier, &ch->ch_neo_uart->ier);
109 
110 	/*
111 	 * From the Neo UART spec sheet:
112 	 * The auto RTS/DTR function must be started by asserting
113 	 * RTS/DTR# output pin (MCR bit-0 or 1 to logic 1 after
114 	 * it is enabled.
115 	 */
116 	ch->ch_mostat |= (UART_MCR_RTS);
117 }
118 
119 
neo_set_ixon_flow_control(struct jsm_channel * ch)120 static void neo_set_ixon_flow_control(struct jsm_channel *ch)
121 {
122 	u8 ier, efr;
123 	ier = readb(&ch->ch_neo_uart->ier);
124 	efr = readb(&ch->ch_neo_uart->efr);
125 
126 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting IXON FLOW\n");
127 
128 	/* Turn off auto CTS flow control */
129 	ier &= ~(UART_17158_IER_CTSDSR);
130 	efr &= ~(UART_17158_EFR_CTSDSR);
131 
132 	/* Turn on auto Xon flow control */
133 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXON);
134 
135 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
136 	writeb(0, &ch->ch_neo_uart->efr);
137 
138 	/* Turn on UART enhanced bits */
139 	writeb(efr, &ch->ch_neo_uart->efr);
140 
141 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
142 	ch->ch_r_watermark = 4;
143 
144 	writeb(32, &ch->ch_neo_uart->rfifo);
145 	ch->ch_r_tlevel = 32;
146 
147 	/* Tell UART what start/stop chars it should be looking for */
148 	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
149 	writeb(0, &ch->ch_neo_uart->xonchar2);
150 
151 	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
152 	writeb(0, &ch->ch_neo_uart->xoffchar2);
153 
154 	writeb(ier, &ch->ch_neo_uart->ier);
155 }
156 
neo_set_ixoff_flow_control(struct jsm_channel * ch)157 static void neo_set_ixoff_flow_control(struct jsm_channel *ch)
158 {
159 	u8 ier, efr;
160 	ier = readb(&ch->ch_neo_uart->ier);
161 	efr = readb(&ch->ch_neo_uart->efr);
162 
163 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting IXOFF FLOW\n");
164 
165 	/* Turn off auto RTS flow control */
166 	ier &= ~(UART_17158_IER_RTSDTR);
167 	efr &= ~(UART_17158_EFR_RTSDTR);
168 
169 	/* Turn on auto Xoff flow control */
170 	ier |= (UART_17158_IER_XOFF);
171 	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
172 
173 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
174 	writeb(0, &ch->ch_neo_uart->efr);
175 
176 	/* Turn on UART enhanced bits */
177 	writeb(efr, &ch->ch_neo_uart->efr);
178 
179 	/* Turn on table D, with 8 char hi/low watermarks */
180 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
181 
182 	writeb(8, &ch->ch_neo_uart->tfifo);
183 	ch->ch_t_tlevel = 8;
184 
185 	/* Tell UART what start/stop chars it should be looking for */
186 	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
187 	writeb(0, &ch->ch_neo_uart->xonchar2);
188 
189 	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
190 	writeb(0, &ch->ch_neo_uart->xoffchar2);
191 
192 	writeb(ier, &ch->ch_neo_uart->ier);
193 }
194 
neo_set_no_input_flow_control(struct jsm_channel * ch)195 static void neo_set_no_input_flow_control(struct jsm_channel *ch)
196 {
197 	u8 ier, efr;
198 	ier = readb(&ch->ch_neo_uart->ier);
199 	efr = readb(&ch->ch_neo_uart->efr);
200 
201 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Unsetting Input FLOW\n");
202 
203 	/* Turn off auto RTS flow control */
204 	ier &= ~(UART_17158_IER_RTSDTR);
205 	efr &= ~(UART_17158_EFR_RTSDTR);
206 
207 	/* Turn off auto Xoff flow control */
208 	ier &= ~(UART_17158_IER_XOFF);
209 	if (ch->ch_c_iflag & IXON)
210 		efr &= ~(UART_17158_EFR_IXOFF);
211 	else
212 		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
213 
214 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
215 	writeb(0, &ch->ch_neo_uart->efr);
216 
217 	/* Turn on UART enhanced bits */
218 	writeb(efr, &ch->ch_neo_uart->efr);
219 
220 	/* Turn on table D, with 8 char hi/low watermarks */
221 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
222 
223 	ch->ch_r_watermark = 0;
224 
225 	writeb(16, &ch->ch_neo_uart->tfifo);
226 	ch->ch_t_tlevel = 16;
227 
228 	writeb(16, &ch->ch_neo_uart->rfifo);
229 	ch->ch_r_tlevel = 16;
230 
231 	writeb(ier, &ch->ch_neo_uart->ier);
232 }
233 
neo_set_no_output_flow_control(struct jsm_channel * ch)234 static void neo_set_no_output_flow_control(struct jsm_channel *ch)
235 {
236 	u8 ier, efr;
237 	ier = readb(&ch->ch_neo_uart->ier);
238 	efr = readb(&ch->ch_neo_uart->efr);
239 
240 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Unsetting Output FLOW\n");
241 
242 	/* Turn off auto CTS flow control */
243 	ier &= ~(UART_17158_IER_CTSDSR);
244 	efr &= ~(UART_17158_EFR_CTSDSR);
245 
246 	/* Turn off auto Xon flow control */
247 	if (ch->ch_c_iflag & IXOFF)
248 		efr &= ~(UART_17158_EFR_IXON);
249 	else
250 		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXON);
251 
252 	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
253 	writeb(0, &ch->ch_neo_uart->efr);
254 
255 	/* Turn on UART enhanced bits */
256 	writeb(efr, &ch->ch_neo_uart->efr);
257 
258 	/* Turn on table D, with 8 char hi/low watermarks */
259 	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
260 
261 	ch->ch_r_watermark = 0;
262 
263 	writeb(16, &ch->ch_neo_uart->tfifo);
264 	ch->ch_t_tlevel = 16;
265 
266 	writeb(16, &ch->ch_neo_uart->rfifo);
267 	ch->ch_r_tlevel = 16;
268 
269 	writeb(ier, &ch->ch_neo_uart->ier);
270 }
271 
neo_set_new_start_stop_chars(struct jsm_channel * ch)272 static inline void neo_set_new_start_stop_chars(struct jsm_channel *ch)
273 {
274 
275 	/* if hardware flow control is set, then skip this whole thing */
276 	if (ch->ch_c_cflag & CRTSCTS)
277 		return;
278 
279 	jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "start\n");
280 
281 	/* Tell UART what start/stop chars it should be looking for */
282 	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
283 	writeb(0, &ch->ch_neo_uart->xonchar2);
284 
285 	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
286 	writeb(0, &ch->ch_neo_uart->xoffchar2);
287 }
288 
neo_copy_data_from_uart_to_queue(struct jsm_channel * ch)289 static void neo_copy_data_from_uart_to_queue(struct jsm_channel *ch)
290 {
291 	int qleft = 0;
292 	u8 linestatus = 0;
293 	u8 error_mask = 0;
294 	int n = 0;
295 	int total = 0;
296 	u16 head;
297 	u16 tail;
298 
299 	if (!ch)
300 		return;
301 
302 	/* cache head and tail of queue */
303 	head = ch->ch_r_head & RQUEUEMASK;
304 	tail = ch->ch_r_tail & RQUEUEMASK;
305 
306 	/* Get our cached LSR */
307 	linestatus = ch->ch_cached_lsr;
308 	ch->ch_cached_lsr = 0;
309 
310 	/* Store how much space we have left in the queue */
311 	if ((qleft = tail - head - 1) < 0)
312 		qleft += RQUEUEMASK + 1;
313 
314 	/*
315 	 * If the UART is not in FIFO mode, force the FIFO copy to
316 	 * NOT be run, by setting total to 0.
317 	 *
318 	 * On the other hand, if the UART IS in FIFO mode, then ask
319 	 * the UART to give us an approximation of data it has RX'ed.
320 	 */
321 	if (!(ch->ch_flags & CH_FIFO_ENABLED))
322 		total = 0;
323 	else {
324 		total = readb(&ch->ch_neo_uart->rfifo);
325 
326 		/*
327 		 * EXAR chip bug - RX FIFO COUNT - Fudge factor.
328 		 *
329 		 * This resolves a problem/bug with the Exar chip that sometimes
330 		 * returns a bogus value in the rfifo register.
331 		 * The count can be any where from 0-3 bytes "off".
332 		 * Bizarre, but true.
333 		 */
334 		total -= 3;
335 	}
336 
337 	/*
338 	 * Finally, bound the copy to make sure we don't overflow
339 	 * our own queue...
340 	 * The byte by byte copy loop below this loop this will
341 	 * deal with the queue overflow possibility.
342 	 */
343 	total = min(total, qleft);
344 
345 	while (total > 0) {
346 		/*
347 		 * Grab the linestatus register, we need to check
348 		 * to see if there are any errors in the FIFO.
349 		 */
350 		linestatus = readb(&ch->ch_neo_uart->lsr);
351 
352 		/*
353 		 * Break out if there is a FIFO error somewhere.
354 		 * This will allow us to go byte by byte down below,
355 		 * finding the exact location of the error.
356 		 */
357 		if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
358 			break;
359 
360 		/* Make sure we don't go over the end of our queue */
361 		n = min(((u32) total), (RQUEUESIZE - (u32) head));
362 
363 		/*
364 		 * Cut down n even further if needed, this is to fix
365 		 * a problem with memcpy_fromio() with the Neo on the
366 		 * IBM pSeries platform.
367 		 * 15 bytes max appears to be the magic number.
368 		 */
369 		n = min((u32) n, (u32) 12);
370 
371 		/*
372 		 * Since we are grabbing the linestatus register, which
373 		 * will reset some bits after our read, we need to ensure
374 		 * we don't miss our TX FIFO emptys.
375 		 */
376 		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
377 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
378 
379 		linestatus = 0;
380 
381 		/* Copy data from uart to the queue */
382 		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
383 		/*
384 		 * Since RX_FIFO_DATA_ERROR was 0, we are guaranteed
385 		 * that all the data currently in the FIFO is free of
386 		 * breaks and parity/frame/orun errors.
387 		 */
388 		memset(ch->ch_equeue + head, 0, n);
389 
390 		/* Add to and flip head if needed */
391 		head = (head + n) & RQUEUEMASK;
392 		total -= n;
393 		qleft -= n;
394 		ch->ch_rxcount += n;
395 	}
396 
397 	/*
398 	 * Create a mask to determine whether we should
399 	 * insert the character (if any) into our queue.
400 	 */
401 	if (ch->ch_c_iflag & IGNBRK)
402 		error_mask |= UART_LSR_BI;
403 
404 	/*
405 	 * Now cleanup any leftover bytes still in the UART.
406 	 * Also deal with any possible queue overflow here as well.
407 	 */
408 	while (1) {
409 
410 		/*
411 		 * Its possible we have a linestatus from the loop above
412 		 * this, so we "OR" on any extra bits.
413 		 */
414 		linestatus |= readb(&ch->ch_neo_uart->lsr);
415 
416 		/*
417 		 * If the chip tells us there is no more data pending to
418 		 * be read, we can then leave.
419 		 * But before we do, cache the linestatus, just in case.
420 		 */
421 		if (!(linestatus & UART_LSR_DR)) {
422 			ch->ch_cached_lsr = linestatus;
423 			break;
424 		}
425 
426 		/* No need to store this bit */
427 		linestatus &= ~UART_LSR_DR;
428 
429 		/*
430 		 * Since we are grabbing the linestatus register, which
431 		 * will reset some bits after our read, we need to ensure
432 		 * we don't miss our TX FIFO emptys.
433 		 */
434 		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
435 			linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
436 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
437 		}
438 
439 		/*
440 		 * Discard character if we are ignoring the error mask.
441 		 */
442 		if (linestatus & error_mask) {
443 			u8 discard;
444 			linestatus = 0;
445 			memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
446 			continue;
447 		}
448 
449 		/*
450 		 * If our queue is full, we have no choice but to drop some data.
451 		 * The assumption is that HWFLOW or SWFLOW should have stopped
452 		 * things way way before we got to this point.
453 		 *
454 		 * I decided that I wanted to ditch the oldest data first,
455 		 * I hope thats okay with everyone? Yes? Good.
456 		 */
457 		while (qleft < 1) {
458 			jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
459 				"Queue full, dropping DATA:%x LSR:%x\n",
460 				ch->ch_rqueue[tail], ch->ch_equeue[tail]);
461 
462 			ch->ch_r_tail = tail = (tail + 1) & RQUEUEMASK;
463 			ch->ch_err_overrun++;
464 			qleft++;
465 		}
466 
467 		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
468 		ch->ch_equeue[head] = (u8) linestatus;
469 
470 		jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
471 				"DATA/LSR pair: %x %x\n", ch->ch_rqueue[head], ch->ch_equeue[head]);
472 
473 		/* Ditch any remaining linestatus value. */
474 		linestatus = 0;
475 
476 		/* Add to and flip head if needed */
477 		head = (head + 1) & RQUEUEMASK;
478 
479 		qleft--;
480 		ch->ch_rxcount++;
481 	}
482 
483 	/*
484 	 * Write new final heads to channel structure.
485 	 */
486 	ch->ch_r_head = head & RQUEUEMASK;
487 	ch->ch_e_head = head & EQUEUEMASK;
488 	jsm_input(ch);
489 }
490 
neo_copy_data_from_queue_to_uart(struct jsm_channel * ch)491 static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
492 {
493 	u16 head;
494 	u16 tail;
495 	int n;
496 	int s;
497 	int qlen;
498 	u32 len_written = 0;
499 	struct circ_buf *circ;
500 
501 	if (!ch)
502 		return;
503 
504 	circ = &ch->uart_port.state->xmit;
505 
506 	/* No data to write to the UART */
507 	if (uart_circ_empty(circ))
508 		return;
509 
510 	/* If port is "stopped", don't send any data to the UART */
511 	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
512 		return;
513 	/*
514 	 * If FIFOs are disabled. Send data directly to txrx register
515 	 */
516 	if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
517 		u8 lsrbits = readb(&ch->ch_neo_uart->lsr);
518 
519 		ch->ch_cached_lsr |= lsrbits;
520 		if (ch->ch_cached_lsr & UART_LSR_THRE) {
521 			ch->ch_cached_lsr &= ~(UART_LSR_THRE);
522 
523 			writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
524 			jsm_printk(WRITE, INFO, &ch->ch_bd->pci_dev,
525 					"Tx data: %x\n", circ->buf[circ->tail]);
526 			circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
527 			ch->ch_txcount++;
528 		}
529 		return;
530 	}
531 
532 	/*
533 	 * We have to do it this way, because of the EXAR TXFIFO count bug.
534 	 */
535 	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
536 		return;
537 
538 	n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
539 
540 	/* cache head and tail of queue */
541 	head = circ->head & (UART_XMIT_SIZE - 1);
542 	tail = circ->tail & (UART_XMIT_SIZE - 1);
543 	qlen = uart_circ_chars_pending(circ);
544 
545 	/* Find minimum of the FIFO space, versus queue length */
546 	n = min(n, qlen);
547 
548 	while (n > 0) {
549 
550 		s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
551 		s = min(s, n);
552 
553 		if (s <= 0)
554 			break;
555 
556 		memcpy_toio(&ch->ch_neo_uart->txrxburst, circ->buf + tail, s);
557 		/* Add and flip queue if needed */
558 		tail = (tail + s) & (UART_XMIT_SIZE - 1);
559 		n -= s;
560 		ch->ch_txcount += s;
561 		len_written += s;
562 	}
563 
564 	/* Update the final tail */
565 	circ->tail = tail & (UART_XMIT_SIZE - 1);
566 
567 	if (len_written >= ch->ch_t_tlevel)
568 		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
569 
570 	if (uart_circ_empty(circ))
571 		uart_write_wakeup(&ch->uart_port);
572 }
573 
neo_parse_modem(struct jsm_channel * ch,u8 signals)574 static void neo_parse_modem(struct jsm_channel *ch, u8 signals)
575 {
576 	u8 msignals = signals;
577 
578 	jsm_printk(MSIGS, INFO, &ch->ch_bd->pci_dev,
579 			"neo_parse_modem: port: %d msignals: %x\n", ch->ch_portnum, msignals);
580 
581 	/* Scrub off lower bits. They signify delta's, which I don't care about */
582 	/* Keep DDCD and DDSR though */
583 	msignals &= 0xf8;
584 
585 	if (msignals & UART_MSR_DDCD)
586 		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
587 	if (msignals & UART_MSR_DDSR)
588 		uart_handle_cts_change(&ch->uart_port, msignals & UART_MSR_CTS);
589 	if (msignals & UART_MSR_DCD)
590 		ch->ch_mistat |= UART_MSR_DCD;
591 	else
592 		ch->ch_mistat &= ~UART_MSR_DCD;
593 
594 	if (msignals & UART_MSR_DSR)
595 		ch->ch_mistat |= UART_MSR_DSR;
596 	else
597 		ch->ch_mistat &= ~UART_MSR_DSR;
598 
599 	if (msignals & UART_MSR_RI)
600 		ch->ch_mistat |= UART_MSR_RI;
601 	else
602 		ch->ch_mistat &= ~UART_MSR_RI;
603 
604 	if (msignals & UART_MSR_CTS)
605 		ch->ch_mistat |= UART_MSR_CTS;
606 	else
607 		ch->ch_mistat &= ~UART_MSR_CTS;
608 
609 	jsm_printk(MSIGS, INFO, &ch->ch_bd->pci_dev,
610 			"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
611 		ch->ch_portnum,
612 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
613 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
614 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
615 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
616 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
617 		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
618 }
619 
620 /* Make the UART raise any of the output signals we want up */
neo_assert_modem_signals(struct jsm_channel * ch)621 static void neo_assert_modem_signals(struct jsm_channel *ch)
622 {
623 	if (!ch)
624 		return;
625 
626 	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
627 
628 	/* flush write operation */
629 	neo_pci_posting_flush(ch->ch_bd);
630 }
631 
632 /*
633  * Flush the WRITE FIFO on the Neo.
634  *
635  * NOTE: Channel lock MUST be held before calling this function!
636  */
neo_flush_uart_write(struct jsm_channel * ch)637 static void neo_flush_uart_write(struct jsm_channel *ch)
638 {
639 	u8 tmp = 0;
640 	int i = 0;
641 
642 	if (!ch)
643 		return;
644 
645 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
646 
647 	for (i = 0; i < 10; i++) {
648 
649 		/* Check to see if the UART feels it completely flushed the FIFO. */
650 		tmp = readb(&ch->ch_neo_uart->isr_fcr);
651 		if (tmp & 4) {
652 			jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev,
653 					"Still flushing TX UART... i: %d\n", i);
654 			udelay(10);
655 		}
656 		else
657 			break;
658 	}
659 
660 	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
661 }
662 
663 
664 /*
665  * Flush the READ FIFO on the Neo.
666  *
667  * NOTE: Channel lock MUST be held before calling this function!
668  */
neo_flush_uart_read(struct jsm_channel * ch)669 static void neo_flush_uart_read(struct jsm_channel *ch)
670 {
671 	u8 tmp = 0;
672 	int i = 0;
673 
674 	if (!ch)
675 		return;
676 
677 	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
678 
679 	for (i = 0; i < 10; i++) {
680 
681 		/* Check to see if the UART feels it completely flushed the FIFO. */
682 		tmp = readb(&ch->ch_neo_uart->isr_fcr);
683 		if (tmp & 2) {
684 			jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev,
685 					"Still flushing RX UART... i: %d\n", i);
686 			udelay(10);
687 		}
688 		else
689 			break;
690 	}
691 }
692 
693 /*
694  * No locks are assumed to be held when calling this function.
695  */
neo_clear_break(struct jsm_channel * ch,int force)696 static void neo_clear_break(struct jsm_channel *ch, int force)
697 {
698 	unsigned long lock_flags;
699 
700 	spin_lock_irqsave(&ch->ch_lock, lock_flags);
701 
702 	/* Turn break off, and unset some variables */
703 	if (ch->ch_flags & CH_BREAK_SENDING) {
704 		u8 temp = readb(&ch->ch_neo_uart->lcr);
705 		writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
706 
707 		ch->ch_flags &= ~(CH_BREAK_SENDING);
708 		jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev,
709 				"clear break Finishing UART_LCR_SBC! finished: %lx\n", jiffies);
710 
711 		/* flush write operation */
712 		neo_pci_posting_flush(ch->ch_bd);
713 	}
714 	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
715 }
716 
717 /*
718  * Parse the ISR register.
719  */
neo_parse_isr(struct jsm_board * brd,u32 port)720 static inline void neo_parse_isr(struct jsm_board *brd, u32 port)
721 {
722 	struct jsm_channel *ch;
723 	u8 isr;
724 	u8 cause;
725 	unsigned long lock_flags;
726 
727 	if (!brd)
728 		return;
729 
730 	if (port > brd->maxports)
731 		return;
732 
733 	ch = brd->channels[port];
734 	if (!ch)
735 		return;
736 
737 	/* Here we try to figure out what caused the interrupt to happen */
738 	while (1) {
739 
740 		isr = readb(&ch->ch_neo_uart->isr_fcr);
741 
742 		/* Bail if no pending interrupt */
743 		if (isr & UART_IIR_NO_INT)
744 			break;
745 
746 		/*
747 		 * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
748 		 */
749 		isr &= ~(UART_17158_IIR_FIFO_ENABLED);
750 
751 		jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
752 				"%s:%d isr: %x\n", __FILE__, __LINE__, isr);
753 
754 		if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
755 			/* Read data from uart -> queue */
756 			neo_copy_data_from_uart_to_queue(ch);
757 
758 			/* Call our tty layer to enforce queue flow control if needed. */
759 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
760 			jsm_check_queue_flow_control(ch);
761 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
762 		}
763 
764 		if (isr & UART_IIR_THRI) {
765 			/* Transfer data (if any) from Write Queue -> UART. */
766 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
767 			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
768 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
769 			neo_copy_data_from_queue_to_uart(ch);
770 		}
771 
772 		if (isr & UART_17158_IIR_XONXOFF) {
773 			cause = readb(&ch->ch_neo_uart->xoffchar1);
774 
775 			jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
776 					"Port %d. Got ISR_XONXOFF: cause:%x\n", port, cause);
777 
778 			/*
779 			 * Since the UART detected either an XON or
780 			 * XOFF match, we need to figure out which
781 			 * one it was, so we can suspend or resume data flow.
782 			 */
783 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
784 			if (cause == UART_17158_XON_DETECT) {
785 				/* Is output stopped right now, if so, resume it */
786 				if (brd->channels[port]->ch_flags & CH_STOP) {
787 					ch->ch_flags &= ~(CH_STOP);
788 				}
789 				jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
790 						"Port %d. XON detected in incoming data\n", port);
791 			}
792 			else if (cause == UART_17158_XOFF_DETECT) {
793 				if (!(brd->channels[port]->ch_flags & CH_STOP)) {
794 					ch->ch_flags |= CH_STOP;
795 					jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
796 							"Setting CH_STOP\n");
797 				}
798 				jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
799 						"Port: %d. XOFF detected in incoming data\n", port);
800 			}
801 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
802 		}
803 
804 		if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
805 			/*
806 			 * If we get here, this means the hardware is doing auto flow control.
807 			 * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
808 			 */
809 			cause = readb(&ch->ch_neo_uart->mcr);
810 
811 			/* Which pin is doing auto flow? RTS or DTR? */
812 			spin_lock_irqsave(&ch->ch_lock, lock_flags);
813 			if ((cause & 0x4) == 0) {
814 				if (cause & UART_MCR_RTS)
815 					ch->ch_mostat |= UART_MCR_RTS;
816 				else
817 					ch->ch_mostat &= ~(UART_MCR_RTS);
818 			} else {
819 				if (cause & UART_MCR_DTR)
820 					ch->ch_mostat |= UART_MCR_DTR;
821 				else
822 					ch->ch_mostat &= ~(UART_MCR_DTR);
823 			}
824 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
825 		}
826 
827 		/* Parse any modem signal changes */
828 		jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
829 				"MOD_STAT: sending to parse_modem_sigs\n");
830 		neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
831 	}
832 }
833 
neo_parse_lsr(struct jsm_board * brd,u32 port)834 static inline void neo_parse_lsr(struct jsm_board *brd, u32 port)
835 {
836 	struct jsm_channel *ch;
837 	int linestatus;
838 	unsigned long lock_flags;
839 
840 	if (!brd)
841 		return;
842 
843 	if (port > brd->maxports)
844 		return;
845 
846 	ch = brd->channels[port];
847 	if (!ch)
848 		return;
849 
850 	linestatus = readb(&ch->ch_neo_uart->lsr);
851 
852 	jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
853 			"%s:%d port: %d linestatus: %x\n", __FILE__, __LINE__, port, linestatus);
854 
855 	ch->ch_cached_lsr |= linestatus;
856 
857 	if (ch->ch_cached_lsr & UART_LSR_DR) {
858 		/* Read data from uart -> queue */
859 		neo_copy_data_from_uart_to_queue(ch);
860 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
861 		jsm_check_queue_flow_control(ch);
862 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
863 	}
864 
865 	/*
866 	 * This is a special flag. It indicates that at least 1
867 	 * RX error (parity, framing, or break) has happened.
868 	 * Mark this in our struct, which will tell me that I have
869 	 *to do the special RX+LSR read for this FIFO load.
870 	 */
871 	if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
872 		jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
873 			"%s:%d Port: %d Got an RX error, need to parse LSR\n",
874 			__FILE__, __LINE__, port);
875 
876 	/*
877 	 * The next 3 tests should *NOT* happen, as the above test
878 	 * should encapsulate all 3... At least, thats what Exar says.
879 	 */
880 
881 	if (linestatus & UART_LSR_PE) {
882 		ch->ch_err_parity++;
883 		jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
884 			"%s:%d Port: %d. PAR ERR!\n", __FILE__, __LINE__, port);
885 	}
886 
887 	if (linestatus & UART_LSR_FE) {
888 		ch->ch_err_frame++;
889 		jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
890 			"%s:%d Port: %d. FRM ERR!\n", __FILE__, __LINE__, port);
891 	}
892 
893 	if (linestatus & UART_LSR_BI) {
894 		ch->ch_err_break++;
895 		jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
896 			"%s:%d Port: %d. BRK INTR!\n", __FILE__, __LINE__, port);
897 	}
898 
899 	if (linestatus & UART_LSR_OE) {
900 		/*
901 		 * Rx Oruns. Exar says that an orun will NOT corrupt
902 		 * the FIFO. It will just replace the holding register
903 		 * with this new data byte. So basically just ignore this.
904 		 * Probably we should eventually have an orun stat in our driver...
905 		 */
906 		ch->ch_err_overrun++;
907 		jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
908 			"%s:%d Port: %d. Rx Overrun!\n", __FILE__, __LINE__, port);
909 	}
910 
911 	if (linestatus & UART_LSR_THRE) {
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 	else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
920 		spin_lock_irqsave(&ch->ch_lock, lock_flags);
921 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
922 		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
923 
924 		/* Transfer data (if any) from Write Queue -> UART. */
925 		neo_copy_data_from_queue_to_uart(ch);
926 	}
927 }
928 
929 /*
930  * neo_param()
931  * Send any/all changes to the line to the UART.
932  */
neo_param(struct jsm_channel * ch)933 static void neo_param(struct jsm_channel *ch)
934 {
935 	u8 lcr = 0;
936 	u8 uart_lcr, ier;
937 	u32 baud;
938 	int quot;
939 	struct jsm_board *bd;
940 
941 	bd = ch->ch_bd;
942 	if (!bd)
943 		return;
944 
945 	/*
946 	 * If baud rate is zero, flush queues, and set mval to drop DTR.
947 	 */
948 	if ((ch->ch_c_cflag & (CBAUD)) == 0) {
949 		ch->ch_r_head = ch->ch_r_tail = 0;
950 		ch->ch_e_head = ch->ch_e_tail = 0;
951 
952 		neo_flush_uart_write(ch);
953 		neo_flush_uart_read(ch);
954 
955 		ch->ch_flags |= (CH_BAUD0);
956 		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
957 		neo_assert_modem_signals(ch);
958 		return;
959 
960 	} else {
961 		int i;
962 		unsigned int cflag;
963 		static struct {
964 			unsigned int rate;
965 			unsigned int cflag;
966 		} baud_rates[] = {
967 			{ 921600, B921600 },
968 			{ 460800, B460800 },
969 			{ 230400, B230400 },
970 			{ 115200, B115200 },
971 			{  57600, B57600  },
972 			{  38400, B38400  },
973 			{  19200, B19200  },
974 			{   9600, B9600   },
975 			{   4800, B4800   },
976 			{   2400, B2400   },
977 			{   1200, B1200   },
978 			{    600, B600    },
979 			{    300, B300    },
980 			{    200, B200    },
981 			{    150, B150    },
982 			{    134, B134    },
983 			{    110, B110    },
984 			{     75, B75     },
985 			{     50, B50     },
986 		};
987 
988 		cflag = C_BAUD(ch->uart_port.state->port.tty);
989 		baud = 9600;
990 		for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
991 			if (baud_rates[i].cflag == cflag) {
992 				baud = baud_rates[i].rate;
993 				break;
994 			}
995 		}
996 
997 		if (ch->ch_flags & CH_BAUD0)
998 			ch->ch_flags &= ~(CH_BAUD0);
999 	}
1000 
1001 	if (ch->ch_c_cflag & PARENB)
1002 		lcr |= UART_LCR_PARITY;
1003 
1004 	if (!(ch->ch_c_cflag & PARODD))
1005 		lcr |= UART_LCR_EPAR;
1006 
1007 	/*
1008 	 * Not all platforms support mark/space parity,
1009 	 * so this will hide behind an ifdef.
1010 	 */
1011 #ifdef CMSPAR
1012 	if (ch->ch_c_cflag & CMSPAR)
1013 		lcr |= UART_LCR_SPAR;
1014 #endif
1015 
1016 	if (ch->ch_c_cflag & CSTOPB)
1017 		lcr |= UART_LCR_STOP;
1018 
1019 	switch (ch->ch_c_cflag & CSIZE) {
1020 		case CS5:
1021 			lcr |= UART_LCR_WLEN5;
1022 			break;
1023 		case CS6:
1024 			lcr |= UART_LCR_WLEN6;
1025 			break;
1026 		case CS7:
1027 			lcr |= UART_LCR_WLEN7;
1028 			break;
1029 		case CS8:
1030 		default:
1031 			lcr |= UART_LCR_WLEN8;
1032 		break;
1033 	}
1034 
1035 	ier = readb(&ch->ch_neo_uart->ier);
1036 	uart_lcr = readb(&ch->ch_neo_uart->lcr);
1037 
1038 	if (baud == 0)
1039 		baud = 9600;
1040 
1041 	quot = ch->ch_bd->bd_dividend / baud;
1042 
1043 	if (quot != 0) {
1044 		writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
1045 		writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
1046 		writeb((quot >> 8), &ch->ch_neo_uart->ier);
1047 		writeb(lcr, &ch->ch_neo_uart->lcr);
1048 	}
1049 
1050 	if (uart_lcr != lcr)
1051 		writeb(lcr, &ch->ch_neo_uart->lcr);
1052 
1053 	if (ch->ch_c_cflag & CREAD)
1054 		ier |= (UART_IER_RDI | UART_IER_RLSI);
1055 
1056 	ier |= (UART_IER_THRI | UART_IER_MSI);
1057 
1058 	writeb(ier, &ch->ch_neo_uart->ier);
1059 
1060 	/* Set new start/stop chars */
1061 	neo_set_new_start_stop_chars(ch);
1062 
1063 	if (ch->ch_c_cflag & CRTSCTS)
1064 		neo_set_cts_flow_control(ch);
1065 	else if (ch->ch_c_iflag & IXON) {
1066 		/* If start/stop is set to disable, then we should disable flow control */
1067 		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1068 			neo_set_no_output_flow_control(ch);
1069 		else
1070 			neo_set_ixon_flow_control(ch);
1071 	}
1072 	else
1073 		neo_set_no_output_flow_control(ch);
1074 
1075 	if (ch->ch_c_cflag & CRTSCTS)
1076 		neo_set_rts_flow_control(ch);
1077 	else if (ch->ch_c_iflag & IXOFF) {
1078 		/* If start/stop is set to disable, then we should disable flow control */
1079 		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1080 			neo_set_no_input_flow_control(ch);
1081 		else
1082 			neo_set_ixoff_flow_control(ch);
1083 	}
1084 	else
1085 		neo_set_no_input_flow_control(ch);
1086 	/*
1087 	 * Adjust the RX FIFO Trigger level if baud is less than 9600.
1088 	 * Not exactly elegant, but this is needed because of the Exar chip's
1089 	 * delay on firing off the RX FIFO interrupt on slower baud rates.
1090 	 */
1091 	if (baud < 9600) {
1092 		writeb(1, &ch->ch_neo_uart->rfifo);
1093 		ch->ch_r_tlevel = 1;
1094 	}
1095 
1096 	neo_assert_modem_signals(ch);
1097 
1098 	/* Get current status of the modem signals now */
1099 	neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
1100 	return;
1101 }
1102 
1103 /*
1104  * jsm_neo_intr()
1105  *
1106  * Neo specific interrupt handler.
1107  */
neo_intr(int irq,void * voidbrd)1108 static irqreturn_t neo_intr(int irq, void *voidbrd)
1109 {
1110 	struct jsm_board *brd = voidbrd;
1111 	struct jsm_channel *ch;
1112 	int port = 0;
1113 	int type = 0;
1114 	int current_port;
1115 	u32 tmp;
1116 	u32 uart_poll;
1117 	unsigned long lock_flags;
1118 	unsigned long lock_flags2;
1119 	int outofloop_count = 0;
1120 
1121 	/* Lock out the slow poller from running on this board. */
1122 	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
1123 
1124 	/*
1125 	 * Read in "extended" IRQ information from the 32bit Neo register.
1126 	 * Bits 0-7: What port triggered the interrupt.
1127 	 * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
1128 	 */
1129 	uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
1130 
1131 	jsm_printk(INTR, INFO, &brd->pci_dev,
1132 		"%s:%d uart_poll: %x\n", __FILE__, __LINE__, uart_poll);
1133 
1134 	if (!uart_poll) {
1135 		jsm_printk(INTR, INFO, &brd->pci_dev,
1136 			"Kernel interrupted to me, but no pending interrupts...\n");
1137 		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1138 		return IRQ_NONE;
1139 	}
1140 
1141 	/* At this point, we have at least SOMETHING to service, dig further... */
1142 
1143 	current_port = 0;
1144 
1145 	/* Loop on each port */
1146 	while (((uart_poll & 0xff) != 0) && (outofloop_count < 0xff)){
1147 
1148 		tmp = uart_poll;
1149 		outofloop_count++;
1150 
1151 		/* Check current port to see if it has interrupt pending */
1152 		if ((tmp & jsm_offset_table[current_port]) != 0) {
1153 			port = current_port;
1154 			type = tmp >> (8 + (port * 3));
1155 			type &= 0x7;
1156 		} else {
1157 			current_port++;
1158 			continue;
1159 		}
1160 
1161 		jsm_printk(INTR, INFO, &brd->pci_dev,
1162 		"%s:%d port: %x type: %x\n", __FILE__, __LINE__, port, type);
1163 
1164 		/* Remove this port + type from uart_poll */
1165 		uart_poll &= ~(jsm_offset_table[port]);
1166 
1167 		if (!type) {
1168 			/* If no type, just ignore it, and move onto next port */
1169 			jsm_printk(INTR, ERR, &brd->pci_dev,
1170 				"Interrupt with no type! port: %d\n", port);
1171 			continue;
1172 		}
1173 
1174 		/* Switch on type of interrupt we have */
1175 		switch (type) {
1176 
1177 		case UART_17158_RXRDY_TIMEOUT:
1178 			/*
1179 			 * RXRDY Time-out is cleared by reading data in the
1180 			* RX FIFO until it falls below the trigger level.
1181 			 */
1182 
1183 			/* Verify the port is in range. */
1184 			if (port > brd->nasync)
1185 				continue;
1186 
1187 			ch = brd->channels[port];
1188 			neo_copy_data_from_uart_to_queue(ch);
1189 
1190 			/* Call our tty layer to enforce queue flow control if needed. */
1191 			spin_lock_irqsave(&ch->ch_lock, lock_flags2);
1192 			jsm_check_queue_flow_control(ch);
1193 			spin_unlock_irqrestore(&ch->ch_lock, lock_flags2);
1194 
1195 			continue;
1196 
1197 		case UART_17158_RX_LINE_STATUS:
1198 			/*
1199 			 * RXRDY and RX LINE Status (logic OR of LSR[4:1])
1200 			 */
1201 			neo_parse_lsr(brd, port);
1202 			continue;
1203 
1204 		case UART_17158_TXRDY:
1205 			/*
1206 			 * TXRDY interrupt clears after reading ISR register for the UART channel.
1207 			 */
1208 
1209 			/*
1210 			 * Yes, this is odd...
1211 			 * Why would I check EVERY possibility of type of
1212 			 * interrupt, when we know its TXRDY???
1213 			 * Becuz for some reason, even tho we got triggered for TXRDY,
1214 			 * it seems to be occasionally wrong. Instead of TX, which
1215 			 * it should be, I was getting things like RXDY too. Weird.
1216 			 */
1217 			neo_parse_isr(brd, port);
1218 			continue;
1219 
1220 		case UART_17158_MSR:
1221 			/*
1222 			 * MSR or flow control was seen.
1223 			 */
1224 			neo_parse_isr(brd, port);
1225 			continue;
1226 
1227 		default:
1228 			/*
1229 			 * The UART triggered us with a bogus interrupt type.
1230 			 * It appears the Exar chip, when REALLY bogged down, will throw
1231 			 * these once and awhile.
1232 			 * Its harmless, just ignore it and move on.
1233 			 */
1234 			jsm_printk(INTR, ERR, &brd->pci_dev,
1235 				"%s:%d Unknown Interrupt type: %x\n", __FILE__, __LINE__, type);
1236 			continue;
1237 		}
1238 	}
1239 
1240 	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1241 
1242 	jsm_printk(INTR, INFO, &brd->pci_dev, "finish.\n");
1243 	return IRQ_HANDLED;
1244 }
1245 
1246 /*
1247  * Neo specific way of turning off the receiver.
1248  * Used as a way to enforce queue flow control when in
1249  * hardware flow control mode.
1250  */
neo_disable_receiver(struct jsm_channel * ch)1251 static void neo_disable_receiver(struct jsm_channel *ch)
1252 {
1253 	u8 tmp = readb(&ch->ch_neo_uart->ier);
1254 	tmp &= ~(UART_IER_RDI);
1255 	writeb(tmp, &ch->ch_neo_uart->ier);
1256 
1257 	/* flush write operation */
1258 	neo_pci_posting_flush(ch->ch_bd);
1259 }
1260 
1261 
1262 /*
1263  * Neo specific way of turning on the receiver.
1264  * Used as a way to un-enforce queue flow control when in
1265  * hardware flow control mode.
1266  */
neo_enable_receiver(struct jsm_channel * ch)1267 static void neo_enable_receiver(struct jsm_channel *ch)
1268 {
1269 	u8 tmp = readb(&ch->ch_neo_uart->ier);
1270 	tmp |= (UART_IER_RDI);
1271 	writeb(tmp, &ch->ch_neo_uart->ier);
1272 
1273 	/* flush write operation */
1274 	neo_pci_posting_flush(ch->ch_bd);
1275 }
1276 
neo_send_start_character(struct jsm_channel * ch)1277 static void neo_send_start_character(struct jsm_channel *ch)
1278 {
1279 	if (!ch)
1280 		return;
1281 
1282 	if (ch->ch_startc != __DISABLED_CHAR) {
1283 		ch->ch_xon_sends++;
1284 		writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
1285 
1286 		/* flush write operation */
1287 		neo_pci_posting_flush(ch->ch_bd);
1288 	}
1289 }
1290 
neo_send_stop_character(struct jsm_channel * ch)1291 static void neo_send_stop_character(struct jsm_channel *ch)
1292 {
1293 	if (!ch)
1294 		return;
1295 
1296 	if (ch->ch_stopc != __DISABLED_CHAR) {
1297 		ch->ch_xoff_sends++;
1298 		writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
1299 
1300 		/* flush write operation */
1301 		neo_pci_posting_flush(ch->ch_bd);
1302 	}
1303 }
1304 
1305 /*
1306  * neo_uart_init
1307  */
neo_uart_init(struct jsm_channel * ch)1308 static void neo_uart_init(struct jsm_channel *ch)
1309 {
1310 	writeb(0, &ch->ch_neo_uart->ier);
1311 	writeb(0, &ch->ch_neo_uart->efr);
1312 	writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
1313 
1314 	/* Clear out UART and FIFO */
1315 	readb(&ch->ch_neo_uart->txrx);
1316 	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1317 	readb(&ch->ch_neo_uart->lsr);
1318 	readb(&ch->ch_neo_uart->msr);
1319 
1320 	ch->ch_flags |= CH_FIFO_ENABLED;
1321 
1322 	/* Assert any signals we want up */
1323 	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
1324 }
1325 
1326 /*
1327  * Make the UART completely turn off.
1328  */
neo_uart_off(struct jsm_channel * ch)1329 static void neo_uart_off(struct jsm_channel *ch)
1330 {
1331 	/* Turn off UART enhanced bits */
1332 	writeb(0, &ch->ch_neo_uart->efr);
1333 
1334 	/* Stop all interrupts from occurring. */
1335 	writeb(0, &ch->ch_neo_uart->ier);
1336 }
1337 
neo_get_uart_bytes_left(struct jsm_channel * ch)1338 static u32 neo_get_uart_bytes_left(struct jsm_channel *ch)
1339 {
1340 	u8 left = 0;
1341 	u8 lsr = readb(&ch->ch_neo_uart->lsr);
1342 
1343 	/* We must cache the LSR as some of the bits get reset once read... */
1344 	ch->ch_cached_lsr |= lsr;
1345 
1346 	/* Determine whether the Transmitter is empty or not */
1347 	if (!(lsr & UART_LSR_TEMT))
1348 		left = 1;
1349 	else {
1350 		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1351 		left = 0;
1352 	}
1353 
1354 	return left;
1355 }
1356 
1357 /* Channel lock MUST be held by the calling function! */
neo_send_break(struct jsm_channel * ch)1358 static void neo_send_break(struct jsm_channel *ch)
1359 {
1360 	/*
1361 	 * Set the time we should stop sending the break.
1362 	 * If we are already sending a break, toss away the existing
1363 	 * time to stop, and use this new value instead.
1364 	 */
1365 
1366 	/* Tell the UART to start sending the break */
1367 	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
1368 		u8 temp = readb(&ch->ch_neo_uart->lcr);
1369 		writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1370 		ch->ch_flags |= (CH_BREAK_SENDING);
1371 
1372 		/* flush write operation */
1373 		neo_pci_posting_flush(ch->ch_bd);
1374 	}
1375 }
1376 
1377 /*
1378  * neo_send_immediate_char.
1379  *
1380  * Sends a specific character as soon as possible to the UART,
1381  * jumping over any bytes that might be in the write queue.
1382  *
1383  * The channel lock MUST be held by the calling function.
1384  */
neo_send_immediate_char(struct jsm_channel * ch,unsigned char c)1385 static void neo_send_immediate_char(struct jsm_channel *ch, unsigned char c)
1386 {
1387 	if (!ch)
1388 		return;
1389 
1390 	writeb(c, &ch->ch_neo_uart->txrx);
1391 
1392 	/* flush write operation */
1393 	neo_pci_posting_flush(ch->ch_bd);
1394 }
1395 
1396 struct board_ops jsm_neo_ops = {
1397 	.intr				= neo_intr,
1398 	.uart_init			= neo_uart_init,
1399 	.uart_off			= neo_uart_off,
1400 	.param				= neo_param,
1401 	.assert_modem_signals		= neo_assert_modem_signals,
1402 	.flush_uart_write		= neo_flush_uart_write,
1403 	.flush_uart_read		= neo_flush_uart_read,
1404 	.disable_receiver		= neo_disable_receiver,
1405 	.enable_receiver		= neo_enable_receiver,
1406 	.send_break			= neo_send_break,
1407 	.clear_break			= neo_clear_break,
1408 	.send_start_character		= neo_send_start_character,
1409 	.send_stop_character		= neo_send_stop_character,
1410 	.copy_data_from_queue_to_uart	= neo_copy_data_from_queue_to_uart,
1411 	.get_uart_bytes_left		= neo_get_uart_bytes_left,
1412 	.send_immediate_char		= neo_send_immediate_char
1413 };
1414