1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright 2003 Digi International (www.digi.com)
  4 *	Scott H Kilau <Scott_Kilau at digi dot com>
  5 *
  6 *	NOTE TO LINUX KERNEL HACKERS:  DO NOT REFORMAT THIS CODE!
  7 *
  8 *	This is shared code between Digi's CVS archive and the
  9 *	Linux Kernel sources.
 10 *	Changing the source just for reformatting needlessly breaks
 11 *	our CVS diff history.
 12 *
 13 *	Send any bug fixes/changes to:  Eng.Linux at digi dot com.
 14 *	Thank you.
 15 *
 16 */
 17
 18#include <linux/delay.h>	/* For udelay */
 19#include <linux/io.h>		/* For read[bwl]/write[bwl] */
 20#include <linux/serial.h>	/* For struct async_serial */
 21#include <linux/serial_reg.h>	/* For the various UART offsets */
 22#include <linux/pci.h>
 23#include <linux/tty.h>
 24
 25#include "jsm.h"	/* Driver main header file */
 26
 27static struct {
 28	unsigned int rate;
 29	unsigned int cflag;
 30} baud_rates[] = {
 31	{ 921600, B921600 },
 32	{ 460800, B460800 },
 33	{ 230400, B230400 },
 34	{ 115200, B115200 },
 35	{  57600, B57600  },
 36	{  38400, B38400  },
 37	{  19200, B19200  },
 38	{   9600, B9600   },
 39	{   4800, B4800   },
 40	{   2400, B2400   },
 41	{   1200, B1200   },
 42	{    600, B600    },
 43	{    300, B300    },
 44	{    200, B200    },
 45	{    150, B150    },
 46	{    134, B134    },
 47	{    110, B110    },
 48	{     75, B75     },
 49	{     50, B50     },
 50};
 51
 52static void cls_set_cts_flow_control(struct jsm_channel *ch)
 53{
 54	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 55	u8 ier = readb(&ch->ch_cls_uart->ier);
 56	u8 isr_fcr = 0;
 57
 58	/*
 59	 * The Enhanced Register Set may only be accessed when
 60	 * the Line Control Register is set to 0xBFh.
 61	 */
 62	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 63
 64	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 65
 66	/* Turn on CTS flow control, turn off IXON flow control */
 67	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_CTSDSR);
 68	isr_fcr &= ~(UART_EXAR654_EFR_IXON);
 69
 70	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 71
 72	/* Write old LCR value back out, which turns enhanced access off */
 73	writeb(lcrb, &ch->ch_cls_uart->lcr);
 74
 75	/*
 76	 * Enable interrupts for CTS flow, turn off interrupts for
 77	 * received XOFF chars
 78	 */
 79	ier |= (UART_EXAR654_IER_CTSDSR);
 80	ier &= ~(UART_EXAR654_IER_XOFF);
 81	writeb(ier, &ch->ch_cls_uart->ier);
 82
 83	/* Set the usual FIFO values */
 84	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
 85
 86	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
 87		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
 88		&ch->ch_cls_uart->isr_fcr);
 89
 90	ch->ch_t_tlevel = 16;
 91}
 92
 93static void cls_set_ixon_flow_control(struct jsm_channel *ch)
 94{
 95	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 96	u8 ier = readb(&ch->ch_cls_uart->ier);
 97	u8 isr_fcr = 0;
 98
 99	/*
100	 * The Enhanced Register Set may only be accessed when
101	 * the Line Control Register is set to 0xBFh.
102	 */
103	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
104
105	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
106
107	/* Turn on IXON flow control, turn off CTS flow control */
108	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXON);
109	isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR);
110
111	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
112
113	/* Now set our current start/stop chars while in enhanced mode */
114	writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
115	writeb(0, &ch->ch_cls_uart->lsr);
116	writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
117	writeb(0, &ch->ch_cls_uart->spr);
118
119	/* Write old LCR value back out, which turns enhanced access off */
120	writeb(lcrb, &ch->ch_cls_uart->lcr);
121
122	/*
123	 * Disable interrupts for CTS flow, turn on interrupts for
124	 * received XOFF chars
125	 */
126	ier &= ~(UART_EXAR654_IER_CTSDSR);
127	ier |= (UART_EXAR654_IER_XOFF);
128	writeb(ier, &ch->ch_cls_uart->ier);
129
130	/* Set the usual FIFO values */
131	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
132
133	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
134		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
135		&ch->ch_cls_uart->isr_fcr);
136}
137
138static void cls_set_no_output_flow_control(struct jsm_channel *ch)
139{
140	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
141	u8 ier = readb(&ch->ch_cls_uart->ier);
142	u8 isr_fcr = 0;
143
144	/*
145	 * The Enhanced Register Set may only be accessed when
146	 * the Line Control Register is set to 0xBFh.
147	 */
148	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
149
150	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
151
152	/* Turn off IXON flow control, turn off CTS flow control */
153	isr_fcr |= (UART_EXAR654_EFR_ECB);
154	isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR | UART_EXAR654_EFR_IXON);
155
156	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
157
158	/* Write old LCR value back out, which turns enhanced access off */
159	writeb(lcrb, &ch->ch_cls_uart->lcr);
160
161	/*
162	 * Disable interrupts for CTS flow, turn off interrupts for
163	 * received XOFF chars
164	 */
165	ier &= ~(UART_EXAR654_IER_CTSDSR);
166	ier &= ~(UART_EXAR654_IER_XOFF);
167	writeb(ier, &ch->ch_cls_uart->ier);
168
169	/* Set the usual FIFO values */
170	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
171
172	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
173		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
174		&ch->ch_cls_uart->isr_fcr);
175
176	ch->ch_r_watermark = 0;
177	ch->ch_t_tlevel = 16;
178	ch->ch_r_tlevel = 16;
179}
180
181static void cls_set_rts_flow_control(struct jsm_channel *ch)
182{
183	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
184	u8 ier = readb(&ch->ch_cls_uart->ier);
185	u8 isr_fcr = 0;
186
187	/*
188	 * The Enhanced Register Set may only be accessed when
189	 * the Line Control Register is set to 0xBFh.
190	 */
191	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
192
193	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
194
195	/* Turn on RTS flow control, turn off IXOFF flow control */
196	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_RTSDTR);
197	isr_fcr &= ~(UART_EXAR654_EFR_IXOFF);
198
199	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
200
201	/* Write old LCR value back out, which turns enhanced access off */
202	writeb(lcrb, &ch->ch_cls_uart->lcr);
203
204	/* Enable interrupts for RTS flow */
205	ier |= (UART_EXAR654_IER_RTSDTR);
206	writeb(ier, &ch->ch_cls_uart->ier);
207
208	/* Set the usual FIFO values */
209	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
210
211	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
212		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
213		&ch->ch_cls_uart->isr_fcr);
214
215	ch->ch_r_watermark = 4;
216	ch->ch_r_tlevel = 8;
217}
218
219static void cls_set_ixoff_flow_control(struct jsm_channel *ch)
220{
221	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
222	u8 ier = readb(&ch->ch_cls_uart->ier);
223	u8 isr_fcr = 0;
224
225	/*
226	 * The Enhanced Register Set may only be accessed when
227	 * the Line Control Register is set to 0xBFh.
228	 */
229	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
230
231	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
232
233	/* Turn on IXOFF flow control, turn off RTS flow control */
234	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXOFF);
235	isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR);
236
237	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
238
239	/* Now set our current start/stop chars while in enhanced mode */
240	writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
241	writeb(0, &ch->ch_cls_uart->lsr);
242	writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
243	writeb(0, &ch->ch_cls_uart->spr);
244
245	/* Write old LCR value back out, which turns enhanced access off */
246	writeb(lcrb, &ch->ch_cls_uart->lcr);
247
248	/* Disable interrupts for RTS flow */
249	ier &= ~(UART_EXAR654_IER_RTSDTR);
250	writeb(ier, &ch->ch_cls_uart->ier);
251
252	/* Set the usual FIFO values */
253	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
254
255	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
256		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
257		&ch->ch_cls_uart->isr_fcr);
258}
259
260static void cls_set_no_input_flow_control(struct jsm_channel *ch)
261{
262	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
263	u8 ier = readb(&ch->ch_cls_uart->ier);
264	u8 isr_fcr = 0;
265
266	/*
267	 * The Enhanced Register Set may only be accessed when
268	 * the Line Control Register is set to 0xBFh.
269	 */
270	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
271
272	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
273
274	/* Turn off IXOFF flow control, turn off RTS flow control */
275	isr_fcr |= (UART_EXAR654_EFR_ECB);
276	isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR | UART_EXAR654_EFR_IXOFF);
277
278	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
279
280	/* Write old LCR value back out, which turns enhanced access off */
281	writeb(lcrb, &ch->ch_cls_uart->lcr);
282
283	/* Disable interrupts for RTS flow */
284	ier &= ~(UART_EXAR654_IER_RTSDTR);
285	writeb(ier, &ch->ch_cls_uart->ier);
286
287	/* Set the usual FIFO values */
288	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
289
290	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
291		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
292		&ch->ch_cls_uart->isr_fcr);
293
294	ch->ch_t_tlevel = 16;
295	ch->ch_r_tlevel = 16;
296}
297
298/*
299 * cls_clear_break.
300 * Determines whether its time to shut off break condition.
301 *
302 * No locks are assumed to be held when calling this function.
303 * channel lock is held and released in this function.
304 */
305static void cls_clear_break(struct jsm_channel *ch)
306{
307	unsigned long lock_flags;
308
309	spin_lock_irqsave(&ch->ch_lock, lock_flags);
310
311	/* Turn break off, and unset some variables */
312	if (ch->ch_flags & CH_BREAK_SENDING) {
313		u8 temp = readb(&ch->ch_cls_uart->lcr);
314
315		writeb((temp & ~UART_LCR_SBC), &ch->ch_cls_uart->lcr);
316
317		ch->ch_flags &= ~(CH_BREAK_SENDING);
318		jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
319			"clear break Finishing UART_LCR_SBC! finished: %lx\n",
320			jiffies);
321	}
322	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
323}
324
325static void cls_disable_receiver(struct jsm_channel *ch)
326{
327	u8 tmp = readb(&ch->ch_cls_uart->ier);
328
329	tmp &= ~(UART_IER_RDI);
330	writeb(tmp, &ch->ch_cls_uart->ier);
331}
332
333static void cls_enable_receiver(struct jsm_channel *ch)
334{
335	u8 tmp = readb(&ch->ch_cls_uart->ier);
336
337	tmp |= (UART_IER_RDI);
338	writeb(tmp, &ch->ch_cls_uart->ier);
339}
340
341/* Make the UART raise any of the output signals we want up */
342static void cls_assert_modem_signals(struct jsm_channel *ch)
343{
344	if (!ch)
345		return;
346
347	writeb(ch->ch_mostat, &ch->ch_cls_uart->mcr);
348}
349
350static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
351{
352	int qleft = 0;
353	u8 linestatus;
354	u8 error_mask = 0;
355	u16 head;
356	u16 tail;
357	unsigned long flags;
358
359	if (!ch)
360		return;
361
362	spin_lock_irqsave(&ch->ch_lock, flags);
363
364	/* cache head and tail of queue */
365	head = ch->ch_r_head & RQUEUEMASK;
366	tail = ch->ch_r_tail & RQUEUEMASK;
367
368	ch->ch_cached_lsr = 0;
369
370	/* Store how much space we have left in the queue */
371	qleft = tail - head - 1;
372	if (qleft < 0)
373		qleft += RQUEUEMASK + 1;
374
375	/*
376	 * Create a mask to determine whether we should
377	 * insert the character (if any) into our queue.
378	 */
379	if (ch->ch_c_iflag & IGNBRK)
380		error_mask |= UART_LSR_BI;
381
382	while (1) {
383		/*
384		 * Grab the linestatus register, we need to
385		 * check to see if there is any data to read
386		 */
387		linestatus = readb(&ch->ch_cls_uart->lsr);
388
389		/* Break out if there is no data to fetch */
390		if (!(linestatus & UART_LSR_DR))
391			break;
392
393		/*
394		 * Discard character if we are ignoring the error mask
395		 * which in this case is the break signal.
396		 */
397		if (linestatus & error_mask)  {
398			linestatus = 0;
399			readb(&ch->ch_cls_uart->txrx);
400			continue;
401		}
402
403		/*
404		 * If our queue is full, we have no choice but to drop some
405		 * data. The assumption is that HWFLOW or SWFLOW should have
406		 * stopped things way way before we got to this point.
407		 *
408		 * I decided that I wanted to ditch the oldest data first,
409		 * I hope thats okay with everyone? Yes? Good.
410		 */
411		while (qleft < 1) {
412			tail = (tail + 1) & RQUEUEMASK;
413			ch->ch_r_tail = tail;
414			ch->ch_err_overrun++;
415			qleft++;
416		}
417
418		ch->ch_equeue[head] = linestatus & (UART_LSR_BI | UART_LSR_PE
419								 | UART_LSR_FE);
420		ch->ch_rqueue[head] = readb(&ch->ch_cls_uart->txrx);
421
422		qleft--;
423
424		if (ch->ch_equeue[head] & UART_LSR_PE)
425			ch->ch_err_parity++;
426		if (ch->ch_equeue[head] & UART_LSR_BI)
427			ch->ch_err_break++;
428		if (ch->ch_equeue[head] & UART_LSR_FE)
429			ch->ch_err_frame++;
430
431		/* Add to, and flip head if needed */
432		head = (head + 1) & RQUEUEMASK;
433		ch->ch_rxcount++;
434	}
435
436	/*
437	 * Write new final heads to channel structure.
438	 */
439	ch->ch_r_head = head & RQUEUEMASK;
440	ch->ch_e_head = head & EQUEUEMASK;
441
442	spin_unlock_irqrestore(&ch->ch_lock, flags);
443}
444
445static void cls_copy_data_from_queue_to_uart(struct jsm_channel *ch)
446{
447	u16 tail;
448	int n;
449	int qlen;
450	u32 len_written = 0;
451	struct circ_buf *circ;
452
453	if (!ch)
454		return;
455
456	circ = &ch->uart_port.state->xmit;
457
458	/* No data to write to the UART */
459	if (uart_circ_empty(circ))
460		return;
461
462	/* If port is "stopped", don't send any data to the UART */
463	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
464		return;
465
466	/* We have to do it this way, because of the EXAR TXFIFO count bug. */
467	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
468		return;
469
470	n = 32;
471
472	/* cache tail of queue */
473	tail = circ->tail & (UART_XMIT_SIZE - 1);
474	qlen = uart_circ_chars_pending(circ);
475
476	/* Find minimum of the FIFO space, versus queue length */
477	n = min(n, qlen);
478
479	while (n > 0) {
480		writeb(circ->buf[tail], &ch->ch_cls_uart->txrx);
481		tail = (tail + 1) & (UART_XMIT_SIZE - 1);
482		n--;
483		ch->ch_txcount++;
484		len_written++;
485	}
486
487	/* Update the final tail */
488	circ->tail = tail & (UART_XMIT_SIZE - 1);
489
490	if (len_written > ch->ch_t_tlevel)
491		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
492
493	if (uart_circ_empty(circ))
494		uart_write_wakeup(&ch->uart_port);
495}
496
497static void cls_parse_modem(struct jsm_channel *ch, u8 signals)
498{
499	u8 msignals = signals;
500
501	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
502		"neo_parse_modem: port: %d msignals: %x\n",
503		ch->ch_portnum, msignals);
504
505	/*
506	 * Scrub off lower bits.
507	 * They signify delta's, which I don't care about
508	 * Keep DDCD and DDSR though
509	 */
510	msignals &= 0xf8;
511
512	if (msignals & UART_MSR_DDCD)
513		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
514	if (msignals & UART_MSR_DDSR)
515		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_CTS);
516
517	if (msignals & UART_MSR_DCD)
518		ch->ch_mistat |= UART_MSR_DCD;
519	else
520		ch->ch_mistat &= ~UART_MSR_DCD;
521
522	if (msignals & UART_MSR_DSR)
523		ch->ch_mistat |= UART_MSR_DSR;
524	else
525		ch->ch_mistat &= ~UART_MSR_DSR;
526
527	if (msignals & UART_MSR_RI)
528		ch->ch_mistat |= UART_MSR_RI;
529	else
530		ch->ch_mistat &= ~UART_MSR_RI;
531
532	if (msignals & UART_MSR_CTS)
533		ch->ch_mistat |= UART_MSR_CTS;
534	else
535		ch->ch_mistat &= ~UART_MSR_CTS;
536
537	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
538		"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
539		ch->ch_portnum,
540		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
541		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
542		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
543		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
544		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
545		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
546}
547
548/* Parse the ISR register for the specific port */
549static inline void cls_parse_isr(struct jsm_board *brd, uint port)
550{
551	struct jsm_channel *ch;
552	u8 isr = 0;
553	unsigned long flags;
554
555	/*
556	 * No need to verify board pointer, it was already
557	 * verified in the interrupt routine.
558	 */
559
560	if (port >= brd->nasync)
561		return;
562
563	ch = brd->channels[port];
564	if (!ch)
565		return;
566
567	/* Here we try to figure out what caused the interrupt to happen */
568	while (1) {
569		isr = readb(&ch->ch_cls_uart->isr_fcr);
570
571		/* Bail if no pending interrupt on port */
572		if (isr & UART_IIR_NO_INT)
573			break;
574
575		/* Receive Interrupt pending */
576		if (isr & (UART_IIR_RDI | UART_IIR_RDI_TIMEOUT)) {
577			/* Read data from uart -> queue */
578			cls_copy_data_from_uart_to_queue(ch);
579			jsm_check_queue_flow_control(ch);
580		}
581
582		/* Transmit Hold register empty pending */
583		if (isr & UART_IIR_THRI) {
584			/* Transfer data (if any) from Write Queue -> UART. */
585			spin_lock_irqsave(&ch->ch_lock, flags);
586			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
587			spin_unlock_irqrestore(&ch->ch_lock, flags);
588			cls_copy_data_from_queue_to_uart(ch);
589		}
590
591		/*
592		 * CTS/RTS change of state:
593		 * Don't need to do anything, the cls_parse_modem
594		 * below will grab the updated modem signals.
595		 */
596
597		/* Parse any modem signal changes */
598		cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
599	}
600}
601
602/* Channel lock MUST be held before calling this function! */
603static void cls_flush_uart_write(struct jsm_channel *ch)
604{
605	u8 tmp = 0;
606	u8 i = 0;
607
608	if (!ch)
609		return;
610
611	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT),
612						&ch->ch_cls_uart->isr_fcr);
613
614	for (i = 0; i < 10; i++) {
615		/* Check to see if the UART feels it completely flushed FIFO */
616		tmp = readb(&ch->ch_cls_uart->isr_fcr);
617		if (tmp & UART_FCR_CLEAR_XMIT) {
618			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
619				"Still flushing TX UART... i: %d\n", i);
620			udelay(10);
621		} else
622			break;
623	}
624
625	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
626}
627
628/* Channel lock MUST be held before calling this function! */
629static void cls_flush_uart_read(struct jsm_channel *ch)
630{
631	if (!ch)
632		return;
633
634	/*
635	 * For complete POSIX compatibility, we should be purging the
636	 * read FIFO in the UART here.
637	 *
638	 * However, clearing the read FIFO (UART_FCR_CLEAR_RCVR) also
639	 * incorrectly flushes write data as well as just basically trashing the
640	 * FIFO.
641	 *
642	 * Presumably, this is a bug in this UART.
643	 */
644
645	udelay(10);
646}
647
648static void cls_send_start_character(struct jsm_channel *ch)
649{
650	if (!ch)
651		return;
652
653	if (ch->ch_startc != __DISABLED_CHAR) {
654		ch->ch_xon_sends++;
655		writeb(ch->ch_startc, &ch->ch_cls_uart->txrx);
656	}
657}
658
659static void cls_send_stop_character(struct jsm_channel *ch)
660{
661	if (!ch)
662		return;
663
664	if (ch->ch_stopc != __DISABLED_CHAR) {
665		ch->ch_xoff_sends++;
666		writeb(ch->ch_stopc, &ch->ch_cls_uart->txrx);
667	}
668}
669
670/*
671 * cls_param()
672 * Send any/all changes to the line to the UART.
673 */
674static void cls_param(struct jsm_channel *ch)
675{
676	u8 lcr = 0;
677	u8 uart_lcr = 0;
678	u8 ier = 0;
679	u32 baud = 9600;
680	int quot = 0;
681	struct jsm_board *bd;
682	int i;
683	unsigned int cflag;
684
685	bd = ch->ch_bd;
686	if (!bd)
687		return;
688
689	/*
690	 * If baud rate is zero, flush queues, and set mval to drop DTR.
691	 */
692	if ((ch->ch_c_cflag & CBAUD) == B0) {
693		ch->ch_r_head = 0;
694		ch->ch_r_tail = 0;
695		ch->ch_e_head = 0;
696		ch->ch_e_tail = 0;
697
698		cls_flush_uart_write(ch);
699		cls_flush_uart_read(ch);
700
701		/* The baudrate is B0 so all modem lines are to be dropped. */
702		ch->ch_flags |= (CH_BAUD0);
703		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
704		cls_assert_modem_signals(ch);
705		return;
706	}
707
708	cflag = C_BAUD(ch->uart_port.state->port.tty);
709	baud = 9600;
710	for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
711		if (baud_rates[i].cflag == cflag) {
712			baud = baud_rates[i].rate;
713			break;
714		}
715	}
716
717	if (ch->ch_flags & CH_BAUD0)
718		ch->ch_flags &= ~(CH_BAUD0);
719
720	if (ch->ch_c_cflag & PARENB)
721		lcr |= UART_LCR_PARITY;
722
723	if (!(ch->ch_c_cflag & PARODD))
724		lcr |= UART_LCR_EPAR;
725
726	if (ch->ch_c_cflag & CMSPAR)
727		lcr |= UART_LCR_SPAR;
728
729	if (ch->ch_c_cflag & CSTOPB)
730		lcr |= UART_LCR_STOP;
731
732	lcr |= UART_LCR_WLEN(tty_get_char_size(ch->ch_c_cflag));
733
734	ier = readb(&ch->ch_cls_uart->ier);
735	uart_lcr = readb(&ch->ch_cls_uart->lcr);
736
737	quot = ch->ch_bd->bd_dividend / baud;
738
739	if (quot != 0) {
740		writeb(UART_LCR_DLAB, &ch->ch_cls_uart->lcr);
741		writeb((quot & 0xff), &ch->ch_cls_uart->txrx);
742		writeb((quot >> 8), &ch->ch_cls_uart->ier);
743		writeb(lcr, &ch->ch_cls_uart->lcr);
744	}
745
746	if (uart_lcr != lcr)
747		writeb(lcr, &ch->ch_cls_uart->lcr);
748
749	if (ch->ch_c_cflag & CREAD)
750		ier |= (UART_IER_RDI | UART_IER_RLSI);
751
752	ier |= (UART_IER_THRI | UART_IER_MSI);
753
754	writeb(ier, &ch->ch_cls_uart->ier);
755
756	if (ch->ch_c_cflag & CRTSCTS)
757		cls_set_cts_flow_control(ch);
758	else if (ch->ch_c_iflag & IXON) {
759		/*
760		 * If start/stop is set to disable,
761		 * then we should disable flow control.
762		 */
763		if ((ch->ch_startc == __DISABLED_CHAR) ||
764			(ch->ch_stopc == __DISABLED_CHAR))
765			cls_set_no_output_flow_control(ch);
766		else
767			cls_set_ixon_flow_control(ch);
768	} else
769		cls_set_no_output_flow_control(ch);
770
771	if (ch->ch_c_cflag & CRTSCTS)
772		cls_set_rts_flow_control(ch);
773	else if (ch->ch_c_iflag & IXOFF) {
774		/*
775		 * If start/stop is set to disable,
776		 * then we should disable flow control.
777		 */
778		if ((ch->ch_startc == __DISABLED_CHAR) ||
779			(ch->ch_stopc == __DISABLED_CHAR))
780			cls_set_no_input_flow_control(ch);
781		else
782			cls_set_ixoff_flow_control(ch);
783	} else
784		cls_set_no_input_flow_control(ch);
785
786	cls_assert_modem_signals(ch);
787
788	/* get current status of the modem signals now */
789	cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
790}
791
792/*
793 * cls_intr()
794 *
795 * Classic specific interrupt handler.
796 */
797static irqreturn_t cls_intr(int irq, void *voidbrd)
798{
799	struct jsm_board *brd = voidbrd;
800	unsigned long lock_flags;
801	unsigned char uart_poll;
802	uint i = 0;
803
804	/* Lock out the slow poller from running on this board. */
805	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
806
807	/*
808	 * Check the board's global interrupt offset to see if we
809	 * acctually do have an interrupt pending on us.
810	 */
811	uart_poll = readb(brd->re_map_membase + UART_CLASSIC_POLL_ADDR_OFFSET);
812
813	jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
814		__FILE__, __LINE__, uart_poll);
815
816	if (!uart_poll) {
817		jsm_dbg(INTR, &brd->pci_dev,
818			"Kernel interrupted to me, but no pending interrupts...\n");
819		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
820		return IRQ_NONE;
821	}
822
823	/* At this point, we have at least SOMETHING to service, dig further. */
824
825	/* Parse each port to find out what caused the interrupt */
826	for (i = 0; i < brd->nasync; i++)
827		cls_parse_isr(brd, i);
828
829	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
830
831	return IRQ_HANDLED;
832}
833
834/* Inits UART */
835static void cls_uart_init(struct jsm_channel *ch)
836{
837	unsigned char lcrb = readb(&ch->ch_cls_uart->lcr);
838	unsigned char isr_fcr = 0;
839
840	writeb(0, &ch->ch_cls_uart->ier);
841
842	/*
843	 * The Enhanced Register Set may only be accessed when
844	 * the Line Control Register is set to 0xBFh.
845	 */
846	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
847
848	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
849
850	/* Turn on Enhanced/Extended controls */
851	isr_fcr |= (UART_EXAR654_EFR_ECB);
852
853	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
854
855	/* Write old LCR value back out, which turns enhanced access off */
856	writeb(lcrb, &ch->ch_cls_uart->lcr);
857
858	/* Clear out UART and FIFO */
859	readb(&ch->ch_cls_uart->txrx);
860
861	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT),
862						 &ch->ch_cls_uart->isr_fcr);
863	udelay(10);
864
865	ch->ch_flags |= (CH_FIFO_ENABLED | CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
866
867	readb(&ch->ch_cls_uart->lsr);
868	readb(&ch->ch_cls_uart->msr);
869}
870
871/*
872 * Turns off UART.
873 */
874static void cls_uart_off(struct jsm_channel *ch)
875{
876	/* Stop all interrupts from accurring. */
877	writeb(0, &ch->ch_cls_uart->ier);
878}
879
880/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
881 * cls_send_break.
882 * Starts sending a break thru the UART.
883 *
884 * The channel lock MUST be held by the calling function.
885 */
886static void cls_send_break(struct jsm_channel *ch)
887{
888	/* Tell the UART to start sending the break */
889	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
890		u8 temp = readb(&ch->ch_cls_uart->lcr);
891
892		writeb((temp | UART_LCR_SBC), &ch->ch_cls_uart->lcr);
893		ch->ch_flags |= (CH_BREAK_SENDING);
894	}
895}
896
 
 
 
 
 
 
 
 
 
 
 
 
897struct board_ops jsm_cls_ops = {
898	.intr =				cls_intr,
899	.uart_init =			cls_uart_init,
900	.uart_off =			cls_uart_off,
901	.param =			cls_param,
902	.assert_modem_signals =		cls_assert_modem_signals,
903	.flush_uart_write =		cls_flush_uart_write,
904	.flush_uart_read =		cls_flush_uart_read,
905	.disable_receiver =		cls_disable_receiver,
906	.enable_receiver =		cls_enable_receiver,
907	.send_break =			cls_send_break,
908	.clear_break =			cls_clear_break,
909	.send_start_character =		cls_send_start_character,
910	.send_stop_character =		cls_send_stop_character,
911	.copy_data_from_queue_to_uart = cls_copy_data_from_queue_to_uart,
 
 
912};
913