1/*
2 * Copyright 2003 Digi International (www.digi.com)
3 *	Scott H Kilau <Scott_Kilau at digi dot com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2, or (at your option)
8 * any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
13 * PURPOSE.  See the GNU General Public License for more details.
14 */
15
16
17#include <linux/kernel.h>
18#include <linux/sched.h>	/* For jiffies, task states */
19#include <linux/interrupt.h>    /* For tasklet and interrupt structs/defines */
20#include <linux/delay.h>	/* For udelay */
21#include <linux/io.h>		/* For read[bwl]/write[bwl] */
22#include <linux/serial.h>	/* For struct async_serial */
23#include <linux/serial_reg.h>	/* For the various UART offsets */
24
25#include "dgnc_driver.h"	/* Driver main header file */
26#include "dgnc_neo.h"		/* Our header file */
27#include "dgnc_tty.h"
28
29static inline void neo_parse_lsr(struct dgnc_board *brd, uint port);
30static inline void neo_parse_isr(struct dgnc_board *brd, uint port);
31static void neo_copy_data_from_uart_to_queue(struct channel_t *ch);
32static inline void neo_clear_break(struct channel_t *ch, int force);
33static inline void neo_set_cts_flow_control(struct channel_t *ch);
34static inline void neo_set_rts_flow_control(struct channel_t *ch);
35static inline void neo_set_ixon_flow_control(struct channel_t *ch);
36static inline void neo_set_ixoff_flow_control(struct channel_t *ch);
37static inline void neo_set_no_output_flow_control(struct channel_t *ch);
38static inline void neo_set_no_input_flow_control(struct channel_t *ch);
39static inline void neo_set_new_start_stop_chars(struct channel_t *ch);
40static void neo_parse_modem(struct channel_t *ch, unsigned char signals);
41static void neo_tasklet(unsigned long data);
42static void neo_vpd(struct dgnc_board *brd);
43static void neo_uart_init(struct channel_t *ch);
44static void neo_uart_off(struct channel_t *ch);
45static int neo_drain(struct tty_struct *tty, uint seconds);
46static void neo_param(struct tty_struct *tty);
47static void neo_assert_modem_signals(struct channel_t *ch);
48static void neo_flush_uart_write(struct channel_t *ch);
49static void neo_flush_uart_read(struct channel_t *ch);
50static void neo_disable_receiver(struct channel_t *ch);
51static void neo_enable_receiver(struct channel_t *ch);
52static void neo_send_break(struct channel_t *ch, int msecs);
53static void neo_send_start_character(struct channel_t *ch);
54static void neo_send_stop_character(struct channel_t *ch);
55static void neo_copy_data_from_queue_to_uart(struct channel_t *ch);
56static uint neo_get_uart_bytes_left(struct channel_t *ch);
57static void neo_send_immediate_char(struct channel_t *ch, unsigned char c);
58static irqreturn_t neo_intr(int irq, void *voidbrd);
59
60
61struct board_ops dgnc_neo_ops = {
62	.tasklet =			neo_tasklet,
63	.intr =				neo_intr,
64	.uart_init =			neo_uart_init,
65	.uart_off =			neo_uart_off,
66	.drain =			neo_drain,
67	.param =			neo_param,
68	.vpd =				neo_vpd,
69	.assert_modem_signals =		neo_assert_modem_signals,
70	.flush_uart_write =		neo_flush_uart_write,
71	.flush_uart_read =		neo_flush_uart_read,
72	.disable_receiver =		neo_disable_receiver,
73	.enable_receiver =		neo_enable_receiver,
74	.send_break =			neo_send_break,
75	.send_start_character =		neo_send_start_character,
76	.send_stop_character =		neo_send_stop_character,
77	.copy_data_from_queue_to_uart =	neo_copy_data_from_queue_to_uart,
78	.get_uart_bytes_left =		neo_get_uart_bytes_left,
79	.send_immediate_char =		neo_send_immediate_char
80};
81
82static uint dgnc_offset_table[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
83
84
85/*
86 * This function allows calls to ensure that all outstanding
87 * PCI writes have been completed, by doing a PCI read against
88 * a non-destructive, read-only location on the Neo card.
89 *
90 * In this case, we are reading the DVID (Read-only Device Identification)
91 * value of the Neo card.
92 */
93static inline void neo_pci_posting_flush(struct dgnc_board *bd)
94{
95	readb(bd->re_map_membase + 0x8D);
96}
97
98static inline void neo_set_cts_flow_control(struct channel_t *ch)
99{
100	unsigned char ier = readb(&ch->ch_neo_uart->ier);
101	unsigned char efr = readb(&ch->ch_neo_uart->efr);
102
103
104	/* Turn on auto CTS flow control */
105#if 1
106	ier |= UART_17158_IER_CTSDSR;
107#else
108	ier &= ~(UART_17158_IER_CTSDSR);
109#endif
110
111	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_CTSDSR);
112
113	/* Turn off auto Xon flow control */
114	efr &= ~UART_17158_EFR_IXON;
115
116	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
117	writeb(0, &ch->ch_neo_uart->efr);
118
119	/* Turn on UART enhanced bits */
120	writeb(efr, &ch->ch_neo_uart->efr);
121
122	/* Turn on table D, with 8 char hi/low watermarks */
123	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
124
125	/* Feed the UART our trigger levels */
126	writeb(8, &ch->ch_neo_uart->tfifo);
127	ch->ch_t_tlevel = 8;
128
129	writeb(ier, &ch->ch_neo_uart->ier);
130
131	neo_pci_posting_flush(ch->ch_bd);
132}
133
134
135static inline void neo_set_rts_flow_control(struct channel_t *ch)
136{
137	unsigned char ier = readb(&ch->ch_neo_uart->ier);
138	unsigned char efr = readb(&ch->ch_neo_uart->efr);
139
140	/* Turn on auto RTS flow control */
141#if 1
142	ier |= UART_17158_IER_RTSDTR;
143#else
144	ier &= ~(UART_17158_IER_RTSDTR);
145#endif
146	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_RTSDTR);
147
148	/* Turn off auto Xoff flow control */
149	ier &= ~UART_17158_IER_XOFF;
150	efr &= ~UART_17158_EFR_IXOFF;
151
152	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
153	writeb(0, &ch->ch_neo_uart->efr);
154
155	/* Turn on UART enhanced bits */
156	writeb(efr, &ch->ch_neo_uart->efr);
157
158	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
159	ch->ch_r_watermark = 4;
160
161	writeb(32, &ch->ch_neo_uart->rfifo);
162	ch->ch_r_tlevel = 32;
163
164	writeb(ier, &ch->ch_neo_uart->ier);
165
166	/*
167	 * From the Neo UART spec sheet:
168	 * The auto RTS/DTR function must be started by asserting
169	 * RTS/DTR# output pin (MCR bit-0 or 1 to logic 1 after
170	 * it is enabled.
171	 */
172	ch->ch_mostat |= UART_MCR_RTS;
173
174	neo_pci_posting_flush(ch->ch_bd);
175}
176
177
178static inline void neo_set_ixon_flow_control(struct channel_t *ch)
179{
180	unsigned char ier = readb(&ch->ch_neo_uart->ier);
181	unsigned char efr = readb(&ch->ch_neo_uart->efr);
182
183	/* Turn off auto CTS flow control */
184	ier &= ~UART_17158_IER_CTSDSR;
185	efr &= ~UART_17158_EFR_CTSDSR;
186
187	/* Turn on auto Xon flow control */
188	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXON);
189
190	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
191	writeb(0, &ch->ch_neo_uart->efr);
192
193	/* Turn on UART enhanced bits */
194	writeb(efr, &ch->ch_neo_uart->efr);
195
196	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
197	ch->ch_r_watermark = 4;
198
199	writeb(32, &ch->ch_neo_uart->rfifo);
200	ch->ch_r_tlevel = 32;
201
202	/* Tell UART what start/stop chars it should be looking for */
203	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
204	writeb(0, &ch->ch_neo_uart->xonchar2);
205
206	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
207	writeb(0, &ch->ch_neo_uart->xoffchar2);
208
209	writeb(ier, &ch->ch_neo_uart->ier);
210
211	neo_pci_posting_flush(ch->ch_bd);
212}
213
214
215static inline void neo_set_ixoff_flow_control(struct channel_t *ch)
216{
217	unsigned char ier = readb(&ch->ch_neo_uart->ier);
218	unsigned char efr = readb(&ch->ch_neo_uart->efr);
219
220	/* Turn off auto RTS flow control */
221	ier &= ~UART_17158_IER_RTSDTR;
222	efr &= ~UART_17158_EFR_RTSDTR;
223
224	/* Turn on auto Xoff flow control */
225	ier |= UART_17158_IER_XOFF;
226	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
227
228	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
229	writeb(0, &ch->ch_neo_uart->efr);
230
231	/* Turn on UART enhanced bits */
232	writeb(efr, &ch->ch_neo_uart->efr);
233
234	/* Turn on table D, with 8 char hi/low watermarks */
235	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
236
237	writeb(8, &ch->ch_neo_uart->tfifo);
238	ch->ch_t_tlevel = 8;
239
240	/* Tell UART what start/stop chars it should be looking for */
241	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
242	writeb(0, &ch->ch_neo_uart->xonchar2);
243
244	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
245	writeb(0, &ch->ch_neo_uart->xoffchar2);
246
247	writeb(ier, &ch->ch_neo_uart->ier);
248
249	neo_pci_posting_flush(ch->ch_bd);
250}
251
252
253static inline void neo_set_no_input_flow_control(struct channel_t *ch)
254{
255	unsigned char ier = readb(&ch->ch_neo_uart->ier);
256	unsigned char efr = readb(&ch->ch_neo_uart->efr);
257
258	/* Turn off auto RTS flow control */
259	ier &= ~UART_17158_IER_RTSDTR;
260	efr &= ~UART_17158_EFR_RTSDTR;
261
262	/* Turn off auto Xoff flow control */
263	ier &= ~UART_17158_IER_XOFF;
264	if (ch->ch_c_iflag & IXON)
265		efr &= ~(UART_17158_EFR_IXOFF);
266	else
267		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
268
269
270	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
271	writeb(0, &ch->ch_neo_uart->efr);
272
273	/* Turn on UART enhanced bits */
274	writeb(efr, &ch->ch_neo_uart->efr);
275
276	/* Turn on table D, with 8 char hi/low watermarks */
277	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
278
279	ch->ch_r_watermark = 0;
280
281	writeb(16, &ch->ch_neo_uart->tfifo);
282	ch->ch_t_tlevel = 16;
283
284	writeb(16, &ch->ch_neo_uart->rfifo);
285	ch->ch_r_tlevel = 16;
286
287	writeb(ier, &ch->ch_neo_uart->ier);
288
289	neo_pci_posting_flush(ch->ch_bd);
290}
291
292
293static inline void neo_set_no_output_flow_control(struct channel_t *ch)
294{
295	unsigned char ier = readb(&ch->ch_neo_uart->ier);
296	unsigned char efr = readb(&ch->ch_neo_uart->efr);
297
298	/* Turn off auto CTS flow control */
299	ier &= ~UART_17158_IER_CTSDSR;
300	efr &= ~UART_17158_EFR_CTSDSR;
301
302	/* Turn off auto Xon flow control */
303	if (ch->ch_c_iflag & IXOFF)
304		efr &= ~UART_17158_EFR_IXON;
305	else
306		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXON);
307
308	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
309	writeb(0, &ch->ch_neo_uart->efr);
310
311	/* Turn on UART enhanced bits */
312	writeb(efr, &ch->ch_neo_uart->efr);
313
314	/* Turn on table D, with 8 char hi/low watermarks */
315	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
316
317	ch->ch_r_watermark = 0;
318
319	writeb(16, &ch->ch_neo_uart->tfifo);
320	ch->ch_t_tlevel = 16;
321
322	writeb(16, &ch->ch_neo_uart->rfifo);
323	ch->ch_r_tlevel = 16;
324
325	writeb(ier, &ch->ch_neo_uart->ier);
326
327	neo_pci_posting_flush(ch->ch_bd);
328}
329
330
331/* change UARTs start/stop chars */
332static inline void neo_set_new_start_stop_chars(struct channel_t *ch)
333{
334
335	/* if hardware flow control is set, then skip this whole thing */
336	if (ch->ch_digi.digi_flags & (CTSPACE | RTSPACE) || ch->ch_c_cflag & CRTSCTS)
337		return;
338
339	/* Tell UART what start/stop chars it should be looking for */
340	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
341	writeb(0, &ch->ch_neo_uart->xonchar2);
342
343	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
344	writeb(0, &ch->ch_neo_uart->xoffchar2);
345
346	neo_pci_posting_flush(ch->ch_bd);
347}
348
349
350/*
351 * No locks are assumed to be held when calling this function.
352 */
353static inline void neo_clear_break(struct channel_t *ch, int force)
354{
355	unsigned long flags;
356
357	spin_lock_irqsave(&ch->ch_lock, flags);
358
359	/* Bail if we aren't currently sending a break. */
360	if (!ch->ch_stop_sending_break) {
361		spin_unlock_irqrestore(&ch->ch_lock, flags);
362		return;
363	}
364
365	/* Turn break off, and unset some variables */
366	if (ch->ch_flags & CH_BREAK_SENDING) {
367		if (time_after_eq(jiffies, ch->ch_stop_sending_break)
368		    || force) {
369			unsigned char temp = readb(&ch->ch_neo_uart->lcr);
370
371			writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
372			neo_pci_posting_flush(ch->ch_bd);
373			ch->ch_flags &= ~(CH_BREAK_SENDING);
374			ch->ch_stop_sending_break = 0;
375		}
376	}
377	spin_unlock_irqrestore(&ch->ch_lock, flags);
378}
379
380
381/*
382 * Parse the ISR register.
383 */
384static inline void neo_parse_isr(struct dgnc_board *brd, uint port)
385{
386	struct channel_t *ch;
387	unsigned char isr;
388	unsigned char cause;
389	unsigned long flags;
390
391	if (!brd || brd->magic != DGNC_BOARD_MAGIC)
392		return;
393
394	if (port >= brd->maxports)
395		return;
396
397	ch = brd->channels[port];
398	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
399		return;
400
401	/* Here we try to figure out what caused the interrupt to happen */
402	while (1) {
403
404		isr = readb(&ch->ch_neo_uart->isr_fcr);
405
406		/* Bail if no pending interrupt */
407		if (isr & UART_IIR_NO_INT)
408			break;
409
410		/*
411		 * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
412		 */
413		isr &= ~(UART_17158_IIR_FIFO_ENABLED);
414
415		if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
416			/* Read data from uart -> queue */
417			brd->intr_rx++;
418			ch->ch_intr_rx++;
419			neo_copy_data_from_uart_to_queue(ch);
420
421			/* Call our tty layer to enforce queue flow control if needed. */
422			spin_lock_irqsave(&ch->ch_lock, flags);
423			dgnc_check_queue_flow_control(ch);
424			spin_unlock_irqrestore(&ch->ch_lock, flags);
425		}
426
427		if (isr & UART_IIR_THRI) {
428			brd->intr_tx++;
429			ch->ch_intr_tx++;
430			/* Transfer data (if any) from Write Queue -> UART. */
431			spin_lock_irqsave(&ch->ch_lock, flags);
432			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
433			spin_unlock_irqrestore(&ch->ch_lock, flags);
434			neo_copy_data_from_queue_to_uart(ch);
435		}
436
437		if (isr & UART_17158_IIR_XONXOFF) {
438			cause = readb(&ch->ch_neo_uart->xoffchar1);
439
440			/*
441			 * Since the UART detected either an XON or
442			 * XOFF match, we need to figure out which
443			 * one it was, so we can suspend or resume data flow.
444			 */
445			if (cause == UART_17158_XON_DETECT) {
446				/* Is output stopped right now, if so, resume it */
447				if (brd->channels[port]->ch_flags & CH_STOP) {
448					spin_lock_irqsave(&ch->ch_lock,
449							  flags);
450					ch->ch_flags &= ~(CH_STOP);
451					spin_unlock_irqrestore(&ch->ch_lock,
452							       flags);
453				}
454			} else if (cause == UART_17158_XOFF_DETECT) {
455				if (!(brd->channels[port]->ch_flags & CH_STOP)) {
456					spin_lock_irqsave(&ch->ch_lock,
457							  flags);
458					ch->ch_flags |= CH_STOP;
459					spin_unlock_irqrestore(&ch->ch_lock,
460							       flags);
461				}
462			}
463		}
464
465		if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
466			/*
467			 * If we get here, this means the hardware is doing auto flow control.
468			 * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
469			 */
470			brd->intr_modem++;
471			ch->ch_intr_modem++;
472			cause = readb(&ch->ch_neo_uart->mcr);
473			/* Which pin is doing auto flow? RTS or DTR? */
474			if ((cause & 0x4) == 0) {
475				if (cause & UART_MCR_RTS) {
476					spin_lock_irqsave(&ch->ch_lock,
477							  flags);
478					ch->ch_mostat |= UART_MCR_RTS;
479					spin_unlock_irqrestore(&ch->ch_lock,
480							       flags);
481				} else {
482					spin_lock_irqsave(&ch->ch_lock,
483							  flags);
484					ch->ch_mostat &= ~(UART_MCR_RTS);
485					spin_unlock_irqrestore(&ch->ch_lock,
486							       flags);
487				}
488			} else {
489				if (cause & UART_MCR_DTR) {
490					spin_lock_irqsave(&ch->ch_lock,
491							  flags);
492					ch->ch_mostat |= UART_MCR_DTR;
493					spin_unlock_irqrestore(&ch->ch_lock,
494							       flags);
495				} else {
496					spin_lock_irqsave(&ch->ch_lock,
497							  flags);
498					ch->ch_mostat &= ~(UART_MCR_DTR);
499					spin_unlock_irqrestore(&ch->ch_lock,
500							       flags);
501				}
502			}
503		}
504
505		/* Parse any modem signal changes */
506		neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
507	}
508}
509
510
511static inline void neo_parse_lsr(struct dgnc_board *brd, uint port)
512{
513	struct channel_t *ch;
514	int linestatus;
515	unsigned long flags;
516
517	/*
518	 * Check to make sure it didn't receive interrupt with a null board
519	 * associated or a board pointer that wasn't ours.
520	 */
521	if (!brd || brd->magic != DGNC_BOARD_MAGIC)
522		return;
523
524	if (port >= brd->maxports)
525		return;
526
527	ch = brd->channels[port];
528	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
529		return;
530
531	linestatus = readb(&ch->ch_neo_uart->lsr);
532
533	ch->ch_cached_lsr |= linestatus;
534
535	if (ch->ch_cached_lsr & UART_LSR_DR) {
536		brd->intr_rx++;
537		ch->ch_intr_rx++;
538		/* Read data from uart -> queue */
539		neo_copy_data_from_uart_to_queue(ch);
540		spin_lock_irqsave(&ch->ch_lock, flags);
541		dgnc_check_queue_flow_control(ch);
542		spin_unlock_irqrestore(&ch->ch_lock, flags);
543	}
544
545	/*
546	 * The next 3 tests should *NOT* happen, as the above test
547	 * should encapsulate all 3... At least, thats what Exar says.
548	 */
549
550	if (linestatus & UART_LSR_PE)
551		ch->ch_err_parity++;
552
553	if (linestatus & UART_LSR_FE)
554		ch->ch_err_frame++;
555
556	if (linestatus & UART_LSR_BI)
557		ch->ch_err_break++;
558
559	if (linestatus & UART_LSR_OE) {
560		/*
561		 * Rx Oruns. Exar says that an orun will NOT corrupt
562		 * the FIFO. It will just replace the holding register
563		 * with this new data byte. So basically just ignore this.
564		 * Probably we should eventually have an orun stat in our driver...
565		 */
566		ch->ch_err_overrun++;
567	}
568
569	if (linestatus & UART_LSR_THRE) {
570		brd->intr_tx++;
571		ch->ch_intr_tx++;
572		spin_lock_irqsave(&ch->ch_lock, flags);
573		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
574		spin_unlock_irqrestore(&ch->ch_lock, flags);
575
576		/* Transfer data (if any) from Write Queue -> UART. */
577		neo_copy_data_from_queue_to_uart(ch);
578	} else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
579		brd->intr_tx++;
580		ch->ch_intr_tx++;
581		spin_lock_irqsave(&ch->ch_lock, flags);
582		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
583		spin_unlock_irqrestore(&ch->ch_lock, flags);
584
585		/* Transfer data (if any) from Write Queue -> UART. */
586		neo_copy_data_from_queue_to_uart(ch);
587	}
588}
589
590
591/*
592 * neo_param()
593 * Send any/all changes to the line to the UART.
594 */
595static void neo_param(struct tty_struct *tty)
596{
597	unsigned char lcr = 0;
598	unsigned char uart_lcr = 0;
599	unsigned char ier = 0;
600	unsigned char uart_ier = 0;
601	uint baud = 9600;
602	int quot = 0;
603	struct dgnc_board *bd;
604	struct channel_t *ch;
605	struct un_t   *un;
606
607	if (!tty || tty->magic != TTY_MAGIC)
608		return;
609
610	un = (struct un_t *) tty->driver_data;
611	if (!un || un->magic != DGNC_UNIT_MAGIC)
612		return;
613
614	ch = un->un_ch;
615	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
616		return;
617
618	bd = ch->ch_bd;
619	if (!bd || bd->magic != DGNC_BOARD_MAGIC)
620		return;
621
622	/*
623	 * If baud rate is zero, flush queues, and set mval to drop DTR.
624	 */
625	if ((ch->ch_c_cflag & (CBAUD)) == 0) {
626		ch->ch_r_head = 0;
627		ch->ch_r_tail = 0;
628		ch->ch_e_head = 0;
629		ch->ch_e_tail = 0;
630		ch->ch_w_head = 0;
631		ch->ch_w_tail = 0;
632
633		neo_flush_uart_write(ch);
634		neo_flush_uart_read(ch);
635
636		/* The baudrate is B0 so all modem lines are to be dropped. */
637		ch->ch_flags |= (CH_BAUD0);
638		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
639		neo_assert_modem_signals(ch);
640		ch->ch_old_baud = 0;
641		return;
642
643	} else if (ch->ch_custom_speed) {
644
645		baud = ch->ch_custom_speed;
646		/* Handle transition from B0 */
647		if (ch->ch_flags & CH_BAUD0) {
648			ch->ch_flags &= ~(CH_BAUD0);
649
650			/*
651			 * Bring back up RTS and DTR...
652			 * Also handle RTS or DTR toggle if set.
653			 */
654			if (!(ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE))
655				ch->ch_mostat |= (UART_MCR_RTS);
656			if (!(ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE))
657				ch->ch_mostat |= (UART_MCR_DTR);
658		}
659	} else {
660		int iindex = 0;
661		int jindex = 0;
662
663		ulong bauds[4][16] = {
664			{ /* slowbaud */
665				0,      50,     75,     110,
666				134,    150,    200,    300,
667				600,    1200,   1800,   2400,
668				4800,   9600,   19200,  38400 },
669			{ /* slowbaud & CBAUDEX */
670				0,      57600,  115200, 230400,
671				460800, 150,    200,    921600,
672				600,    1200,   1800,   2400,
673				4800,   9600,   19200,  38400 },
674			{ /* fastbaud */
675				0,      57600,   76800, 115200,
676				131657, 153600, 230400, 460800,
677				921600, 1200,   1800,   2400,
678				4800,   9600,   19200,  38400 },
679			{ /* fastbaud & CBAUDEX */
680				0,      57600,  115200, 230400,
681				460800, 150,    200,    921600,
682				600,    1200,   1800,   2400,
683				4800,   9600,   19200,  38400 }
684		};
685
686		/* Only use the TXPrint baud rate if the terminal unit is NOT open */
687		if (!(ch->ch_tun.un_flags & UN_ISOPEN) && (un->un_type == DGNC_PRINT))
688			baud = C_BAUD(ch->ch_pun.un_tty) & 0xff;
689		else
690			baud = C_BAUD(ch->ch_tun.un_tty) & 0xff;
691
692		if (ch->ch_c_cflag & CBAUDEX)
693			iindex = 1;
694
695		if (ch->ch_digi.digi_flags & DIGI_FAST)
696			iindex += 2;
697
698		jindex = baud;
699
700		if ((iindex >= 0) && (iindex < 4) && (jindex >= 0) && (jindex < 16))
701			baud = bauds[iindex][jindex];
702		else
703			baud = 0;
704
705		if (baud == 0)
706			baud = 9600;
707
708		/* Handle transition from B0 */
709		if (ch->ch_flags & CH_BAUD0) {
710			ch->ch_flags &= ~(CH_BAUD0);
711
712			/*
713			 * Bring back up RTS and DTR...
714			 * Also handle RTS or DTR toggle if set.
715			 */
716			if (!(ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE))
717				ch->ch_mostat |= (UART_MCR_RTS);
718			if (!(ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE))
719				ch->ch_mostat |= (UART_MCR_DTR);
720		}
721	}
722
723	if (ch->ch_c_cflag & PARENB)
724		lcr |= UART_LCR_PARITY;
725
726	if (!(ch->ch_c_cflag & PARODD))
727		lcr |= UART_LCR_EPAR;
728
729	/*
730	 * Not all platforms support mark/space parity,
731	 * so this will hide behind an ifdef.
732	 */
733#ifdef CMSPAR
734	if (ch->ch_c_cflag & CMSPAR)
735		lcr |= UART_LCR_SPAR;
736#endif
737
738	if (ch->ch_c_cflag & CSTOPB)
739		lcr |= UART_LCR_STOP;
740
741	switch (ch->ch_c_cflag & CSIZE) {
742	case CS5:
743		lcr |= UART_LCR_WLEN5;
744		break;
745	case CS6:
746		lcr |= UART_LCR_WLEN6;
747		break;
748	case CS7:
749		lcr |= UART_LCR_WLEN7;
750		break;
751	case CS8:
752	default:
753		lcr |= UART_LCR_WLEN8;
754		break;
755	}
756
757	uart_ier = readb(&ch->ch_neo_uart->ier);
758	ier = uart_ier;
759
760	uart_lcr = readb(&ch->ch_neo_uart->lcr);
761
762	if (baud == 0)
763		baud = 9600;
764
765	quot = ch->ch_bd->bd_dividend / baud;
766
767	if (quot != 0 && ch->ch_old_baud != baud) {
768		ch->ch_old_baud = baud;
769		writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
770		writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
771		writeb((quot >> 8), &ch->ch_neo_uart->ier);
772		writeb(lcr, &ch->ch_neo_uart->lcr);
773	}
774
775	if (uart_lcr != lcr)
776		writeb(lcr, &ch->ch_neo_uart->lcr);
777
778	if (ch->ch_c_cflag & CREAD)
779		ier |= (UART_IER_RDI | UART_IER_RLSI);
780	else
781		ier &= ~(UART_IER_RDI | UART_IER_RLSI);
782
783	/*
784	 * Have the UART interrupt on modem signal changes ONLY when
785	 * we are in hardware flow control mode, or CLOCAL/FORCEDCD is not set.
786	 */
787	if ((ch->ch_digi.digi_flags & CTSPACE) ||
788	    (ch->ch_digi.digi_flags & RTSPACE) ||
789	    (ch->ch_c_cflag & CRTSCTS) ||
790	    !(ch->ch_digi.digi_flags & DIGI_FORCEDCD) ||
791	    !(ch->ch_c_cflag & CLOCAL))
792		ier |= UART_IER_MSI;
793	else
794		ier &= ~UART_IER_MSI;
795
796	ier |= UART_IER_THRI;
797
798	if (ier != uart_ier)
799		writeb(ier, &ch->ch_neo_uart->ier);
800
801	/* Set new start/stop chars */
802	neo_set_new_start_stop_chars(ch);
803
804	if (ch->ch_digi.digi_flags & CTSPACE || ch->ch_c_cflag & CRTSCTS) {
805		neo_set_cts_flow_control(ch);
806	} else if (ch->ch_c_iflag & IXON) {
807		/* If start/stop is set to disable, then we should disable flow control */
808		if ((ch->ch_startc == _POSIX_VDISABLE) || (ch->ch_stopc == _POSIX_VDISABLE))
809			neo_set_no_output_flow_control(ch);
810		else
811			neo_set_ixon_flow_control(ch);
812	} else {
813		neo_set_no_output_flow_control(ch);
814	}
815
816	if (ch->ch_digi.digi_flags & RTSPACE || ch->ch_c_cflag & CRTSCTS) {
817		neo_set_rts_flow_control(ch);
818	} else if (ch->ch_c_iflag & IXOFF) {
819		/* If start/stop is set to disable, then we should disable flow control */
820		if ((ch->ch_startc == _POSIX_VDISABLE) || (ch->ch_stopc == _POSIX_VDISABLE))
821			neo_set_no_input_flow_control(ch);
822		else
823			neo_set_ixoff_flow_control(ch);
824	} else {
825		neo_set_no_input_flow_control(ch);
826	}
827
828	/*
829	 * Adjust the RX FIFO Trigger level if baud is less than 9600.
830	 * Not exactly elegant, but this is needed because of the Exar chip's
831	 * delay on firing off the RX FIFO interrupt on slower baud rates.
832	 */
833	if (baud < 9600) {
834		writeb(1, &ch->ch_neo_uart->rfifo);
835		ch->ch_r_tlevel = 1;
836	}
837
838	neo_assert_modem_signals(ch);
839
840	/* Get current status of the modem signals now */
841	neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
842}
843
844
845/*
846 * Our board poller function.
847 */
848static void neo_tasklet(unsigned long data)
849{
850	struct dgnc_board *bd = (struct dgnc_board *) data;
851	struct channel_t *ch;
852	unsigned long flags;
853	int i;
854	int state = 0;
855	int ports = 0;
856
857	if (!bd || bd->magic != DGNC_BOARD_MAGIC)
858		return;
859
860	/* Cache a couple board values */
861	spin_lock_irqsave(&bd->bd_lock, flags);
862	state = bd->state;
863	ports = bd->nasync;
864	spin_unlock_irqrestore(&bd->bd_lock, flags);
865
866	/*
867	 * Do NOT allow the interrupt routine to read the intr registers
868	 * Until we release this lock.
869	 */
870	spin_lock_irqsave(&bd->bd_intr_lock, flags);
871
872	/*
873	 * If board is ready, parse deeper to see if there is anything to do.
874	 */
875	if ((state == BOARD_READY) && (ports > 0)) {
876		/* Loop on each port */
877		for (i = 0; i < ports; i++) {
878			ch = bd->channels[i];
879
880			/* Just being careful... */
881			if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
882				continue;
883
884			/*
885			 * NOTE: Remember you CANNOT hold any channel
886			 * locks when calling the input routine.
887			 *
888			 * During input processing, its possible we
889			 * will call the Linux ld, which might in turn,
890			 * do a callback right back into us, resulting
891			 * in us trying to grab the channel lock twice!
892			 */
893			dgnc_input(ch);
894
895			/*
896			 * Channel lock is grabbed and then released
897			 * inside both of these routines, but neither
898			 * call anything else that could call back into us.
899			 */
900			neo_copy_data_from_queue_to_uart(ch);
901			dgnc_wakeup_writes(ch);
902
903			/*
904			 * Call carrier carrier function, in case something
905			 * has changed.
906			 */
907			dgnc_carrier(ch);
908
909			/*
910			 * Check to see if we need to turn off a sending break.
911			 * The timing check is done inside clear_break()
912			 */
913			if (ch->ch_stop_sending_break)
914				neo_clear_break(ch, 0);
915		}
916	}
917
918	/* Allow interrupt routine to access the interrupt register again */
919	spin_unlock_irqrestore(&bd->bd_intr_lock, flags);
920
921}
922
923
924/*
925 * dgnc_neo_intr()
926 *
927 * Neo specific interrupt handler.
928 */
929static irqreturn_t neo_intr(int irq, void *voidbrd)
930{
931	struct dgnc_board *brd = voidbrd;
932	struct channel_t *ch;
933	int port = 0;
934	int type = 0;
935	int current_port;
936	u32 tmp;
937	u32 uart_poll;
938	unsigned long flags;
939	unsigned long flags2;
940
941	/*
942	 * Check to make sure it didn't receive interrupt with a null board
943	 * associated or a board pointer that wasn't ours.
944	 */
945	if (!brd || brd->magic != DGNC_BOARD_MAGIC)
946		return IRQ_NONE;
947
948	brd->intr_count++;
949
950	/* Lock out the slow poller from running on this board. */
951	spin_lock_irqsave(&brd->bd_intr_lock, flags);
952
953	/*
954	 * Read in "extended" IRQ information from the 32bit Neo register.
955	 * Bits 0-7: What port triggered the interrupt.
956	 * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
957	 */
958	uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
959
960	/*
961	 * If 0, no interrupts pending.
962	 * This can happen if the IRQ is shared among a couple Neo/Classic boards.
963	 */
964	if (!uart_poll) {
965		spin_unlock_irqrestore(&brd->bd_intr_lock, flags);
966		return IRQ_NONE;
967	}
968
969	/* At this point, we have at least SOMETHING to service, dig further... */
970
971	current_port = 0;
972
973	/* Loop on each port */
974	while ((uart_poll & 0xff) != 0) {
975
976		tmp = uart_poll;
977
978		/* Check current port to see if it has interrupt pending */
979		if ((tmp & dgnc_offset_table[current_port]) != 0) {
980			port = current_port;
981			type = tmp >> (8 + (port * 3));
982			type &= 0x7;
983		} else {
984			current_port++;
985			continue;
986		}
987
988		/* Remove this port + type from uart_poll */
989		uart_poll &= ~(dgnc_offset_table[port]);
990
991		if (!type) {
992			/* If no type, just ignore it, and move onto next port */
993			continue;
994		}
995
996		/* Switch on type of interrupt we have */
997		switch (type) {
998
999		case UART_17158_RXRDY_TIMEOUT:
1000			/*
1001			 * RXRDY Time-out is cleared by reading data in the
1002			 * RX FIFO until it falls below the trigger level.
1003			 */
1004
1005			/* Verify the port is in range. */
1006			if (port >= brd->nasync)
1007				continue;
1008
1009			ch = brd->channels[port];
1010			neo_copy_data_from_uart_to_queue(ch);
1011
1012			/* Call our tty layer to enforce queue flow control if needed. */
1013			spin_lock_irqsave(&ch->ch_lock, flags2);
1014			dgnc_check_queue_flow_control(ch);
1015			spin_unlock_irqrestore(&ch->ch_lock, flags2);
1016
1017			continue;
1018
1019		case UART_17158_RX_LINE_STATUS:
1020			/*
1021			 * RXRDY and RX LINE Status (logic OR of LSR[4:1])
1022			 */
1023			neo_parse_lsr(brd, port);
1024			continue;
1025
1026		case UART_17158_TXRDY:
1027			/*
1028			 * TXRDY interrupt clears after reading ISR register for the UART channel.
1029			 */
1030
1031			/*
1032			 * Yes, this is odd...
1033			 * Why would I check EVERY possibility of type of
1034			 * interrupt, when we know its TXRDY???
1035			 * Becuz for some reason, even tho we got triggered for TXRDY,
1036			 * it seems to be occasionally wrong. Instead of TX, which
1037			 * it should be, I was getting things like RXDY too. Weird.
1038			 */
1039			neo_parse_isr(brd, port);
1040			continue;
1041
1042		case UART_17158_MSR:
1043			/*
1044			 * MSR or flow control was seen.
1045			 */
1046			neo_parse_isr(brd, port);
1047			continue;
1048
1049		default:
1050			/*
1051			 * The UART triggered us with a bogus interrupt type.
1052			 * It appears the Exar chip, when REALLY bogged down, will throw
1053			 * these once and awhile.
1054			 * Its harmless, just ignore it and move on.
1055			 */
1056			continue;
1057		}
1058	}
1059
1060	/*
1061	 * Schedule tasklet to more in-depth servicing at a better time.
1062	 */
1063	tasklet_schedule(&brd->helper_tasklet);
1064
1065	spin_unlock_irqrestore(&brd->bd_intr_lock, flags);
1066
1067	return IRQ_HANDLED;
1068}
1069
1070
1071/*
1072 * Neo specific way of turning off the receiver.
1073 * Used as a way to enforce queue flow control when in
1074 * hardware flow control mode.
1075 */
1076static void neo_disable_receiver(struct channel_t *ch)
1077{
1078	unsigned char tmp = readb(&ch->ch_neo_uart->ier);
1079
1080	tmp &= ~(UART_IER_RDI);
1081	writeb(tmp, &ch->ch_neo_uart->ier);
1082	neo_pci_posting_flush(ch->ch_bd);
1083}
1084
1085
1086/*
1087 * Neo specific way of turning on the receiver.
1088 * Used as a way to un-enforce queue flow control when in
1089 * hardware flow control mode.
1090 */
1091static void neo_enable_receiver(struct channel_t *ch)
1092{
1093	unsigned char tmp = readb(&ch->ch_neo_uart->ier);
1094
1095	tmp |= (UART_IER_RDI);
1096	writeb(tmp, &ch->ch_neo_uart->ier);
1097	neo_pci_posting_flush(ch->ch_bd);
1098}
1099
1100
1101static void neo_copy_data_from_uart_to_queue(struct channel_t *ch)
1102{
1103	int qleft = 0;
1104	unsigned char linestatus = 0;
1105	unsigned char error_mask = 0;
1106	int n = 0;
1107	int total = 0;
1108	ushort head;
1109	ushort tail;
1110	unsigned long flags;
1111
1112	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1113		return;
1114
1115	spin_lock_irqsave(&ch->ch_lock, flags);
1116
1117	/* cache head and tail of queue */
1118	head = ch->ch_r_head & RQUEUEMASK;
1119	tail = ch->ch_r_tail & RQUEUEMASK;
1120
1121	/* Get our cached LSR */
1122	linestatus = ch->ch_cached_lsr;
1123	ch->ch_cached_lsr = 0;
1124
1125	/* Store how much space we have left in the queue */
1126	qleft = tail - head - 1;
1127	if (qleft < 0)
1128		qleft += RQUEUEMASK + 1;
1129
1130	/*
1131	 * If the UART is not in FIFO mode, force the FIFO copy to
1132	 * NOT be run, by setting total to 0.
1133	 *
1134	 * On the other hand, if the UART IS in FIFO mode, then ask
1135	 * the UART to give us an approximation of data it has RX'ed.
1136	 */
1137	if (!(ch->ch_flags & CH_FIFO_ENABLED))
1138		total = 0;
1139	else {
1140		total = readb(&ch->ch_neo_uart->rfifo);
1141
1142		/*
1143		 * EXAR chip bug - RX FIFO COUNT - Fudge factor.
1144		 *
1145		 * This resolves a problem/bug with the Exar chip that sometimes
1146		 * returns a bogus value in the rfifo register.
1147		 * The count can be any where from 0-3 bytes "off".
1148		 * Bizarre, but true.
1149		 */
1150		if ((ch->ch_bd->dvid & 0xf0) >= UART_XR17E158_DVID)
1151			total -= 1;
1152		else
1153			total -= 3;
1154	}
1155
1156
1157	/*
1158	 * Finally, bound the copy to make sure we don't overflow
1159	 * our own queue...
1160	 * The byte by byte copy loop below this loop this will
1161	 * deal with the queue overflow possibility.
1162	 */
1163	total = min(total, qleft);
1164
1165	while (total > 0) {
1166
1167		/*
1168		 * Grab the linestatus register, we need to check
1169		 * to see if there are any errors in the FIFO.
1170		 */
1171		linestatus = readb(&ch->ch_neo_uart->lsr);
1172
1173		/*
1174		 * Break out if there is a FIFO error somewhere.
1175		 * This will allow us to go byte by byte down below,
1176		 * finding the exact location of the error.
1177		 */
1178		if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
1179			break;
1180
1181		/* Make sure we don't go over the end of our queue */
1182		n = min(((uint) total), (RQUEUESIZE - (uint) head));
1183
1184		/*
1185		 * Cut down n even further if needed, this is to fix
1186		 * a problem with memcpy_fromio() with the Neo on the
1187		 * IBM pSeries platform.
1188		 * 15 bytes max appears to be the magic number.
1189		 */
1190		n = min_t(uint, n, 12);
1191
1192		/*
1193		 * Since we are grabbing the linestatus register, which
1194		 * will reset some bits after our read, we need to ensure
1195		 * we don't miss our TX FIFO emptys.
1196		 */
1197		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
1198			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1199
1200		linestatus = 0;
1201
1202		/* Copy data from uart to the queue */
1203		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
1204
1205		/*
1206		 * Since RX_FIFO_DATA_ERROR was 0, we are guarenteed
1207		 * that all the data currently in the FIFO is free of
1208		 * breaks and parity/frame/orun errors.
1209		 */
1210		memset(ch->ch_equeue + head, 0, n);
1211
1212		/* Add to and flip head if needed */
1213		head = (head + n) & RQUEUEMASK;
1214		total -= n;
1215		qleft -= n;
1216		ch->ch_rxcount += n;
1217	}
1218
1219	/*
1220	 * Create a mask to determine whether we should
1221	 * insert the character (if any) into our queue.
1222	 */
1223	if (ch->ch_c_iflag & IGNBRK)
1224		error_mask |= UART_LSR_BI;
1225
1226	/*
1227	 * Now cleanup any leftover bytes still in the UART.
1228	 * Also deal with any possible queue overflow here as well.
1229	 */
1230	while (1) {
1231
1232		/*
1233		 * Its possible we have a linestatus from the loop above
1234		 * this, so we "OR" on any extra bits.
1235		 */
1236		linestatus |= readb(&ch->ch_neo_uart->lsr);
1237
1238		/*
1239		 * If the chip tells us there is no more data pending to
1240		 * be read, we can then leave.
1241		 * But before we do, cache the linestatus, just in case.
1242		 */
1243		if (!(linestatus & UART_LSR_DR)) {
1244			ch->ch_cached_lsr = linestatus;
1245			break;
1246		}
1247
1248		/* No need to store this bit */
1249		linestatus &= ~UART_LSR_DR;
1250
1251		/*
1252		 * Since we are grabbing the linestatus register, which
1253		 * will reset some bits after our read, we need to ensure
1254		 * we don't miss our TX FIFO emptys.
1255		 */
1256		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
1257			linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
1258			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1259		}
1260
1261		/*
1262		 * Discard character if we are ignoring the error mask.
1263		 */
1264		if (linestatus & error_mask)  {
1265			unsigned char discard;
1266
1267			linestatus = 0;
1268			memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
1269			continue;
1270		}
1271
1272		/*
1273		 * If our queue is full, we have no choice but to drop some data.
1274		 * The assumption is that HWFLOW or SWFLOW should have stopped
1275		 * things way way before we got to this point.
1276		 *
1277		 * I decided that I wanted to ditch the oldest data first,
1278		 * I hope thats okay with everyone? Yes? Good.
1279		 */
1280		while (qleft < 1) {
1281			tail = (tail + 1) & RQUEUEMASK;
1282			ch->ch_r_tail = tail;
1283			ch->ch_err_overrun++;
1284			qleft++;
1285		}
1286
1287		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
1288		ch->ch_equeue[head] = (unsigned char) linestatus;
1289
1290		/* Ditch any remaining linestatus value. */
1291		linestatus = 0;
1292
1293		/* Add to and flip head if needed */
1294		head = (head + 1) & RQUEUEMASK;
1295
1296		qleft--;
1297		ch->ch_rxcount++;
1298	}
1299
1300	/*
1301	 * Write new final heads to channel structure.
1302	 */
1303	ch->ch_r_head = head & RQUEUEMASK;
1304	ch->ch_e_head = head & EQUEUEMASK;
1305
1306	spin_unlock_irqrestore(&ch->ch_lock, flags);
1307}
1308
1309
1310/*
1311 * This function basically goes to sleep for secs, or until
1312 * it gets signalled that the port has fully drained.
1313 */
1314static int neo_drain(struct tty_struct *tty, uint seconds)
1315{
1316	unsigned long flags;
1317	struct channel_t *ch;
1318	struct un_t *un;
1319	int rc = 0;
1320
1321	if (!tty || tty->magic != TTY_MAGIC)
1322		return -ENXIO;
1323
1324	un = (struct un_t *) tty->driver_data;
1325	if (!un || un->magic != DGNC_UNIT_MAGIC)
1326		return -ENXIO;
1327
1328	ch = un->un_ch;
1329	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1330		return -ENXIO;
1331
1332	spin_lock_irqsave(&ch->ch_lock, flags);
1333	un->un_flags |= UN_EMPTY;
1334	spin_unlock_irqrestore(&ch->ch_lock, flags);
1335
1336	/*
1337	 * Go to sleep waiting for the tty layer to wake me back up when
1338	 * the empty flag goes away.
1339	 *
1340	 * NOTE: TODO: Do something with time passed in.
1341	 */
1342	rc = wait_event_interruptible(un->un_flags_wait, ((un->un_flags & UN_EMPTY) == 0));
1343
1344	/* If ret is non-zero, user ctrl-c'ed us */
1345	return rc;
1346}
1347
1348
1349/*
1350 * Flush the WRITE FIFO on the Neo.
1351 *
1352 * NOTE: Channel lock MUST be held before calling this function!
1353 */
1354static void neo_flush_uart_write(struct channel_t *ch)
1355{
1356	unsigned char tmp = 0;
1357	int i = 0;
1358
1359	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1360		return;
1361
1362	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1363	neo_pci_posting_flush(ch->ch_bd);
1364
1365	for (i = 0; i < 10; i++) {
1366
1367		/* Check to see if the UART feels it completely flushed the FIFO. */
1368		tmp = readb(&ch->ch_neo_uart->isr_fcr);
1369		if (tmp & 4)
1370			udelay(10);
1371		else
1372			break;
1373	}
1374
1375	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1376}
1377
1378
1379/*
1380 * Flush the READ FIFO on the Neo.
1381 *
1382 * NOTE: Channel lock MUST be held before calling this function!
1383 */
1384static void neo_flush_uart_read(struct channel_t *ch)
1385{
1386	unsigned char tmp = 0;
1387	int i = 0;
1388
1389	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1390		return;
1391
1392	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
1393	neo_pci_posting_flush(ch->ch_bd);
1394
1395	for (i = 0; i < 10; i++) {
1396
1397		/* Check to see if the UART feels it completely flushed the FIFO. */
1398		tmp = readb(&ch->ch_neo_uart->isr_fcr);
1399		if (tmp & 2)
1400			udelay(10);
1401		else
1402			break;
1403	}
1404}
1405
1406
1407static void neo_copy_data_from_queue_to_uart(struct channel_t *ch)
1408{
1409	ushort head;
1410	ushort tail;
1411	int n;
1412	int s;
1413	int qlen;
1414	uint len_written = 0;
1415	unsigned long flags;
1416
1417	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1418		return;
1419
1420	spin_lock_irqsave(&ch->ch_lock, flags);
1421
1422	/* No data to write to the UART */
1423	if (ch->ch_w_tail == ch->ch_w_head)
1424		goto exit_unlock;
1425
1426	/* If port is "stopped", don't send any data to the UART */
1427	if ((ch->ch_flags & CH_FORCED_STOP) ||
1428		 (ch->ch_flags & CH_BREAK_SENDING))
1429		goto exit_unlock;
1430
1431	/*
1432	 * If FIFOs are disabled. Send data directly to txrx register
1433	 */
1434	if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
1435		unsigned char lsrbits = readb(&ch->ch_neo_uart->lsr);
1436
1437		/* Cache the LSR bits for later parsing */
1438		ch->ch_cached_lsr |= lsrbits;
1439		if (ch->ch_cached_lsr & UART_LSR_THRE) {
1440			ch->ch_cached_lsr &= ~(UART_LSR_THRE);
1441
1442			/*
1443			 * If RTS Toggle mode is on, turn on RTS now if not already set,
1444			 * and make sure we get an event when the data transfer has completed.
1445			 */
1446			if (ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) {
1447				if (!(ch->ch_mostat & UART_MCR_RTS)) {
1448					ch->ch_mostat |= (UART_MCR_RTS);
1449					neo_assert_modem_signals(ch);
1450				}
1451				ch->ch_tun.un_flags |= (UN_EMPTY);
1452			}
1453			/*
1454			 * If DTR Toggle mode is on, turn on DTR now if not already set,
1455			 * and make sure we get an event when the data transfer has completed.
1456			 */
1457			if (ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) {
1458				if (!(ch->ch_mostat & UART_MCR_DTR)) {
1459					ch->ch_mostat |= (UART_MCR_DTR);
1460					neo_assert_modem_signals(ch);
1461				}
1462				ch->ch_tun.un_flags |= (UN_EMPTY);
1463			}
1464
1465			writeb(ch->ch_wqueue[ch->ch_w_tail], &ch->ch_neo_uart->txrx);
1466			ch->ch_w_tail++;
1467			ch->ch_w_tail &= WQUEUEMASK;
1468			ch->ch_txcount++;
1469		}
1470
1471		goto exit_unlock;
1472	}
1473
1474	/*
1475	 * We have to do it this way, because of the EXAR TXFIFO count bug.
1476	 */
1477	if ((ch->ch_bd->dvid & 0xf0) < UART_XR17E158_DVID) {
1478		if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
1479			goto exit_unlock;
1480
1481		len_written = 0;
1482
1483		n = readb(&ch->ch_neo_uart->tfifo);
1484
1485		if ((unsigned int) n > ch->ch_t_tlevel)
1486			goto exit_unlock;
1487
1488		n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
1489	} else {
1490		n = UART_17158_TX_FIFOSIZE - readb(&ch->ch_neo_uart->tfifo);
1491	}
1492
1493	/* cache head and tail of queue */
1494	head = ch->ch_w_head & WQUEUEMASK;
1495	tail = ch->ch_w_tail & WQUEUEMASK;
1496	qlen = (head - tail) & WQUEUEMASK;
1497
1498	/* Find minimum of the FIFO space, versus queue length */
1499	n = min(n, qlen);
1500
1501	while (n > 0) {
1502
1503		s = ((head >= tail) ? head : WQUEUESIZE) - tail;
1504		s = min(s, n);
1505
1506		if (s <= 0)
1507			break;
1508
1509		/*
1510		 * If RTS Toggle mode is on, turn on RTS now if not already set,
1511		 * and make sure we get an event when the data transfer has completed.
1512		 */
1513		if (ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) {
1514			if (!(ch->ch_mostat & UART_MCR_RTS)) {
1515				ch->ch_mostat |= (UART_MCR_RTS);
1516				neo_assert_modem_signals(ch);
1517			}
1518			ch->ch_tun.un_flags |= (UN_EMPTY);
1519		}
1520
1521		/*
1522		 * If DTR Toggle mode is on, turn on DTR now if not already set,
1523		 * and make sure we get an event when the data transfer has completed.
1524		 */
1525		if (ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) {
1526			if (!(ch->ch_mostat & UART_MCR_DTR)) {
1527				ch->ch_mostat |= (UART_MCR_DTR);
1528				neo_assert_modem_signals(ch);
1529			}
1530			ch->ch_tun.un_flags |= (UN_EMPTY);
1531		}
1532
1533		memcpy_toio(&ch->ch_neo_uart->txrxburst, ch->ch_wqueue + tail, s);
1534
1535		/* Add and flip queue if needed */
1536		tail = (tail + s) & WQUEUEMASK;
1537		n -= s;
1538		ch->ch_txcount += s;
1539		len_written += s;
1540	}
1541
1542	/* Update the final tail */
1543	ch->ch_w_tail = tail & WQUEUEMASK;
1544
1545	if (len_written > 0) {
1546		neo_pci_posting_flush(ch->ch_bd);
1547		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1548	}
1549
1550exit_unlock:
1551	spin_unlock_irqrestore(&ch->ch_lock, flags);
1552}
1553
1554
1555static void neo_parse_modem(struct channel_t *ch, unsigned char signals)
1556{
1557	unsigned char msignals = signals;
1558
1559	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1560		return;
1561
1562	/*
1563	 * Do altpin switching. Altpin switches DCD and DSR.
1564	 * This prolly breaks DSRPACE, so we should be more clever here.
1565	 */
1566	if (ch->ch_digi.digi_flags & DIGI_ALTPIN) {
1567		unsigned char mswap = msignals;
1568
1569		if (mswap & UART_MSR_DDCD) {
1570			msignals &= ~UART_MSR_DDCD;
1571			msignals |= UART_MSR_DDSR;
1572		}
1573		if (mswap & UART_MSR_DDSR) {
1574			msignals &= ~UART_MSR_DDSR;
1575			msignals |= UART_MSR_DDCD;
1576		}
1577		if (mswap & UART_MSR_DCD) {
1578			msignals &= ~UART_MSR_DCD;
1579			msignals |= UART_MSR_DSR;
1580		}
1581		if (mswap & UART_MSR_DSR) {
1582			msignals &= ~UART_MSR_DSR;
1583			msignals |= UART_MSR_DCD;
1584		}
1585	}
1586
1587	/* Scrub off lower bits. They signify delta's, which I don't care about */
1588	msignals &= 0xf0;
1589
1590	if (msignals & UART_MSR_DCD)
1591		ch->ch_mistat |= UART_MSR_DCD;
1592	else
1593		ch->ch_mistat &= ~UART_MSR_DCD;
1594
1595	if (msignals & UART_MSR_DSR)
1596		ch->ch_mistat |= UART_MSR_DSR;
1597	else
1598		ch->ch_mistat &= ~UART_MSR_DSR;
1599
1600	if (msignals & UART_MSR_RI)
1601		ch->ch_mistat |= UART_MSR_RI;
1602	else
1603		ch->ch_mistat &= ~UART_MSR_RI;
1604
1605	if (msignals & UART_MSR_CTS)
1606		ch->ch_mistat |= UART_MSR_CTS;
1607	else
1608		ch->ch_mistat &= ~UART_MSR_CTS;
1609}
1610
1611
1612/* Make the UART raise any of the output signals we want up */
1613static void neo_assert_modem_signals(struct channel_t *ch)
1614{
1615	unsigned char out;
1616
1617	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1618		return;
1619
1620	out = ch->ch_mostat;
1621
1622	if (ch->ch_flags & CH_LOOPBACK)
1623		out |= UART_MCR_LOOP;
1624
1625	writeb(out, &ch->ch_neo_uart->mcr);
1626	neo_pci_posting_flush(ch->ch_bd);
1627
1628	/* Give time for the UART to actually raise/drop the signals */
1629	udelay(10);
1630}
1631
1632
1633static void neo_send_start_character(struct channel_t *ch)
1634{
1635	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1636		return;
1637
1638	if (ch->ch_startc != _POSIX_VDISABLE) {
1639		ch->ch_xon_sends++;
1640		writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
1641		neo_pci_posting_flush(ch->ch_bd);
1642		udelay(10);
1643	}
1644}
1645
1646
1647static void neo_send_stop_character(struct channel_t *ch)
1648{
1649	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1650		return;
1651
1652	if (ch->ch_stopc != _POSIX_VDISABLE) {
1653		ch->ch_xoff_sends++;
1654		writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
1655		neo_pci_posting_flush(ch->ch_bd);
1656		udelay(10);
1657	}
1658}
1659
1660
1661/*
1662 * neo_uart_init
1663 */
1664static void neo_uart_init(struct channel_t *ch)
1665{
1666
1667	writeb(0, &ch->ch_neo_uart->ier);
1668	writeb(0, &ch->ch_neo_uart->efr);
1669	writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
1670
1671
1672	/* Clear out UART and FIFO */
1673	readb(&ch->ch_neo_uart->txrx);
1674	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1675	readb(&ch->ch_neo_uart->lsr);
1676	readb(&ch->ch_neo_uart->msr);
1677
1678	ch->ch_flags |= CH_FIFO_ENABLED;
1679
1680	/* Assert any signals we want up */
1681	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
1682	neo_pci_posting_flush(ch->ch_bd);
1683}
1684
1685
1686/*
1687 * Make the UART completely turn off.
1688 */
1689static void neo_uart_off(struct channel_t *ch)
1690{
1691	/* Turn off UART enhanced bits */
1692	writeb(0, &ch->ch_neo_uart->efr);
1693
1694	/* Stop all interrupts from occurring. */
1695	writeb(0, &ch->ch_neo_uart->ier);
1696	neo_pci_posting_flush(ch->ch_bd);
1697}
1698
1699
1700static uint neo_get_uart_bytes_left(struct channel_t *ch)
1701{
1702	unsigned char left = 0;
1703	unsigned char lsr = readb(&ch->ch_neo_uart->lsr);
1704
1705	/* We must cache the LSR as some of the bits get reset once read... */
1706	ch->ch_cached_lsr |= lsr;
1707
1708	/* Determine whether the Transmitter is empty or not */
1709	if (!(lsr & UART_LSR_TEMT)) {
1710		if (ch->ch_flags & CH_TX_FIFO_EMPTY)
1711			tasklet_schedule(&ch->ch_bd->helper_tasklet);
1712		left = 1;
1713	} else {
1714		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1715		left = 0;
1716	}
1717
1718	return left;
1719}
1720
1721
1722/* Channel lock MUST be held by the calling function! */
1723static void neo_send_break(struct channel_t *ch, int msecs)
1724{
1725	/*
1726	 * If we receive a time of 0, this means turn off the break.
1727	 */
1728	if (msecs == 0) {
1729		if (ch->ch_flags & CH_BREAK_SENDING) {
1730			unsigned char temp = readb(&ch->ch_neo_uart->lcr);
1731
1732			writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1733			neo_pci_posting_flush(ch->ch_bd);
1734			ch->ch_flags &= ~(CH_BREAK_SENDING);
1735			ch->ch_stop_sending_break = 0;
1736		}
1737		return;
1738	}
1739
1740	/*
1741	 * Set the time we should stop sending the break.
1742	 * If we are already sending a break, toss away the existing
1743	 * time to stop, and use this new value instead.
1744	 */
1745	ch->ch_stop_sending_break = jiffies + dgnc_jiffies_from_ms(msecs);
1746
1747	/* Tell the UART to start sending the break */
1748	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
1749		unsigned char temp = readb(&ch->ch_neo_uart->lcr);
1750
1751		writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1752		neo_pci_posting_flush(ch->ch_bd);
1753		ch->ch_flags |= (CH_BREAK_SENDING);
1754	}
1755}
1756
1757
1758/*
1759 * neo_send_immediate_char.
1760 *
1761 * Sends a specific character as soon as possible to the UART,
1762 * jumping over any bytes that might be in the write queue.
1763 *
1764 * The channel lock MUST be held by the calling function.
1765 */
1766static void neo_send_immediate_char(struct channel_t *ch, unsigned char c)
1767{
1768	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
1769		return;
1770
1771	writeb(c, &ch->ch_neo_uart->txrx);
1772	neo_pci_posting_flush(ch->ch_bd);
1773}
1774
1775
1776static unsigned int neo_read_eeprom(unsigned char __iomem *base, unsigned int address)
1777{
1778	unsigned int enable;
1779	unsigned int bits;
1780	unsigned int databit;
1781	unsigned int val;
1782
1783	/* enable chip select */
1784	writeb(NEO_EECS, base + NEO_EEREG);
1785	/* READ */
1786	enable = (address | 0x180);
1787
1788	for (bits = 9; bits--; ) {
1789		databit = (enable & (1 << bits)) ? NEO_EEDI : 0;
1790		/* Set read address */
1791		writeb(databit | NEO_EECS, base + NEO_EEREG);
1792		writeb(databit | NEO_EECS | NEO_EECK, base + NEO_EEREG);
1793	}
1794
1795	val = 0;
1796
1797	for (bits = 17; bits--; ) {
1798		/* clock to EEPROM */
1799		writeb(NEO_EECS, base + NEO_EEREG);
1800		writeb(NEO_EECS | NEO_EECK, base + NEO_EEREG);
1801		val <<= 1;
1802		/* read EEPROM */
1803		if (readb(base + NEO_EEREG) & NEO_EEDO)
1804			val |= 1;
1805	}
1806
1807	/* clock falling edge */
1808	writeb(NEO_EECS, base + NEO_EEREG);
1809
1810	/* drop chip select */
1811	writeb(0x00, base + NEO_EEREG);
1812
1813	return val;
1814}
1815
1816
1817static void neo_vpd(struct dgnc_board *brd)
1818{
1819	unsigned int i = 0;
1820	unsigned int a;
1821
1822	if (!brd || brd->magic != DGNC_BOARD_MAGIC)
1823		return;
1824
1825	if (!brd->re_map_membase)
1826		return;
1827
1828	/* Store the VPD into our buffer */
1829	for (i = 0; i < NEO_VPD_IMAGESIZE; i++) {
1830		a = neo_read_eeprom(brd->re_map_membase, i);
1831		brd->vpd[i*2] = a & 0xff;
1832		brd->vpd[(i*2)+1] = (a >> 8) & 0xff;
1833	}
1834
1835	if  (((brd->vpd[0x08] != 0x82)	   /* long resource name tag */
1836		&&  (brd->vpd[0x10] != 0x82))   /* long resource name tag (PCI-66 files)*/
1837		||  (brd->vpd[0x7F] != 0x78)) { /* small resource end tag */
1838
1839		memset(brd->vpd, '\0', NEO_VPD_IMAGESIZE);
1840	} else {
1841		/* Search for the serial number */
1842		for (i = 0; i < NEO_VPD_IMAGEBYTES - 3; i++)
1843			if (brd->vpd[i] == 'S' && brd->vpd[i + 1] == 'N')
1844				strncpy(brd->serial_num, &(brd->vpd[i + 3]), 9);
1845	}
1846}
1847