xref: /linux/drivers/tty/amiserial.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Serial driver for the amiga builtin port.
3  *
4  * This code was created by taking serial.c version 4.30 from kernel
5  * release 2.3.22, replacing all hardware related stuff with the
6  * corresponding amiga hardware actions, and removing all irrelevant
7  * code. As a consequence, it uses many of the constants and names
8  * associated with the registers and bits of 16550 compatible UARTS -
9  * but only to keep track of status, etc in the state variables. It
10  * was done this was to make it easier to keep the code in line with
11  * (non hardware specific) changes to serial.c.
12  *
13  * The port is registered with the tty driver as minor device 64, and
14  * therefore other ports should should only use 65 upwards.
15  *
16  * Richard Lucock 28/12/99
17  *
18  *  Copyright (C) 1991, 1992  Linus Torvalds
19  *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
20  * 		1998, 1999  Theodore Ts'o
21  *
22  */
23 
24 /*
25  * Serial driver configuration section.  Here are the various options:
26  *
27  * SERIAL_PARANOIA_CHECK
28  * 		Check the magic number for the async_structure where
29  * 		ever possible.
30  */
31 
32 #include <linux/delay.h>
33 
34 #undef SERIAL_PARANOIA_CHECK
35 #define SERIAL_DO_RESTART
36 
37 /* Set of debugging defines */
38 
39 #undef SERIAL_DEBUG_INTR
40 #undef SERIAL_DEBUG_OPEN
41 #undef SERIAL_DEBUG_FLOW
42 #undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
43 
44 /* Sanity checks */
45 
46 #if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
47 #define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
48  tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
49 #else
50 #define DBG_CNT(s)
51 #endif
52 
53 /*
54  * End of serial driver configuration section.
55  */
56 
57 #include <linux/module.h>
58 
59 #include <linux/types.h>
60 #include <linux/serial.h>
61 #include <linux/serial_reg.h>
62 static char *serial_version = "4.30";
63 
64 #include <linux/errno.h>
65 #include <linux/signal.h>
66 #include <linux/sched.h>
67 #include <linux/kernel.h>
68 #include <linux/timer.h>
69 #include <linux/interrupt.h>
70 #include <linux/tty.h>
71 #include <linux/tty_flip.h>
72 #include <linux/circ_buf.h>
73 #include <linux/console.h>
74 #include <linux/major.h>
75 #include <linux/string.h>
76 #include <linux/fcntl.h>
77 #include <linux/ptrace.h>
78 #include <linux/ioport.h>
79 #include <linux/mm.h>
80 #include <linux/seq_file.h>
81 #include <linux/slab.h>
82 #include <linux/init.h>
83 #include <linux/bitops.h>
84 #include <linux/platform_device.h>
85 
86 #include <asm/setup.h>
87 
88 
89 #include <asm/irq.h>
90 
91 #include <asm/amigahw.h>
92 #include <asm/amigaints.h>
93 
94 struct serial_state {
95 	struct tty_port		tport;
96 	struct circ_buf		xmit;
97 	struct async_icount	icount;
98 
99 	unsigned long		port;
100 	int			baud_base;
101 	int			xmit_fifo_size;
102 	int			custom_divisor;
103 	int			read_status_mask;
104 	int			ignore_status_mask;
105 	int			timeout;
106 	int			quot;
107 	int			IER; 	/* Interrupt Enable Register */
108 	int			MCR; 	/* Modem control register */
109 	int			x_char;	/* xon/xoff character */
110 };
111 
112 #define custom amiga_custom
113 static char *serial_name = "Amiga-builtin serial driver";
114 
115 static struct tty_driver *serial_driver;
116 
117 /* number of characters left in xmit buffer before we ask for more */
118 #define WAKEUP_CHARS 256
119 
120 static unsigned char current_ctl_bits;
121 
122 static void change_speed(struct tty_struct *tty, struct serial_state *info,
123 		struct ktermios *old);
124 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
125 
126 
127 static struct serial_state rs_table[1];
128 
129 #define NR_PORTS ARRAY_SIZE(rs_table)
130 
131 #include <asm/uaccess.h>
132 
133 #define serial_isroot()	(capable(CAP_SYS_ADMIN))
134 
135 
136 static inline int serial_paranoia_check(struct serial_state *info,
137 					char *name, const char *routine)
138 {
139 #ifdef SERIAL_PARANOIA_CHECK
140 	static const char *badmagic =
141 		"Warning: bad magic number for serial struct (%s) in %s\n";
142 	static const char *badinfo =
143 		"Warning: null async_struct for (%s) in %s\n";
144 
145 	if (!info) {
146 		printk(badinfo, name, routine);
147 		return 1;
148 	}
149 	if (info->magic != SERIAL_MAGIC) {
150 		printk(badmagic, name, routine);
151 		return 1;
152 	}
153 #endif
154 	return 0;
155 }
156 
157 /* some serial hardware definitions */
158 #define SDR_OVRUN   (1<<15)
159 #define SDR_RBF     (1<<14)
160 #define SDR_TBE     (1<<13)
161 #define SDR_TSRE    (1<<12)
162 
163 #define SERPER_PARENB    (1<<15)
164 
165 #define AC_SETCLR   (1<<15)
166 #define AC_UARTBRK  (1<<11)
167 
168 #define SER_DTR     (1<<7)
169 #define SER_RTS     (1<<6)
170 #define SER_DCD     (1<<5)
171 #define SER_CTS     (1<<4)
172 #define SER_DSR     (1<<3)
173 
174 static __inline__ void rtsdtr_ctrl(int bits)
175 {
176     ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
177 }
178 
179 /*
180  * ------------------------------------------------------------
181  * rs_stop() and rs_start()
182  *
183  * This routines are called before setting or resetting tty->stopped.
184  * They enable or disable transmitter interrupts, as necessary.
185  * ------------------------------------------------------------
186  */
187 static void rs_stop(struct tty_struct *tty)
188 {
189 	struct serial_state *info = tty->driver_data;
190 	unsigned long flags;
191 
192 	if (serial_paranoia_check(info, tty->name, "rs_stop"))
193 		return;
194 
195 	local_irq_save(flags);
196 	if (info->IER & UART_IER_THRI) {
197 		info->IER &= ~UART_IER_THRI;
198 		/* disable Tx interrupt and remove any pending interrupts */
199 		custom.intena = IF_TBE;
200 		mb();
201 		custom.intreq = IF_TBE;
202 		mb();
203 	}
204 	local_irq_restore(flags);
205 }
206 
207 static void rs_start(struct tty_struct *tty)
208 {
209 	struct serial_state *info = tty->driver_data;
210 	unsigned long flags;
211 
212 	if (serial_paranoia_check(info, tty->name, "rs_start"))
213 		return;
214 
215 	local_irq_save(flags);
216 	if (info->xmit.head != info->xmit.tail
217 	    && info->xmit.buf
218 	    && !(info->IER & UART_IER_THRI)) {
219 		info->IER |= UART_IER_THRI;
220 		custom.intena = IF_SETCLR | IF_TBE;
221 		mb();
222 		/* set a pending Tx Interrupt, transmitter should restart now */
223 		custom.intreq = IF_SETCLR | IF_TBE;
224 		mb();
225 	}
226 	local_irq_restore(flags);
227 }
228 
229 /*
230  * ----------------------------------------------------------------------
231  *
232  * Here starts the interrupt handling routines.  All of the following
233  * subroutines are declared as inline and are folded into
234  * rs_interrupt().  They were separated out for readability's sake.
235  *
236  * Note: rs_interrupt() is a "fast" interrupt, which means that it
237  * runs with interrupts turned off.  People who may want to modify
238  * rs_interrupt() should try to keep the interrupt handler as fast as
239  * possible.  After you are done making modifications, it is not a bad
240  * idea to do:
241  *
242  * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
243  *
244  * and look at the resulting assemble code in serial.s.
245  *
246  * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
247  * -----------------------------------------------------------------------
248  */
249 
250 static void receive_chars(struct serial_state *info)
251 {
252         int status;
253 	int serdatr;
254 	struct tty_struct *tty = info->tport.tty;
255 	unsigned char ch, flag;
256 	struct	async_icount *icount;
257 	int oe = 0;
258 
259 	icount = &info->icount;
260 
261 	status = UART_LSR_DR; /* We obviously have a character! */
262 	serdatr = custom.serdatr;
263 	mb();
264 	custom.intreq = IF_RBF;
265 	mb();
266 
267 	if((serdatr & 0x1ff) == 0)
268 	    status |= UART_LSR_BI;
269 	if(serdatr & SDR_OVRUN)
270 	    status |= UART_LSR_OE;
271 
272 	ch = serdatr & 0xff;
273 	icount->rx++;
274 
275 #ifdef SERIAL_DEBUG_INTR
276 	printk("DR%02x:%02x...", ch, status);
277 #endif
278 	flag = TTY_NORMAL;
279 
280 	/*
281 	 * We don't handle parity or frame errors - but I have left
282 	 * the code in, since I'm not sure that the errors can't be
283 	 * detected.
284 	 */
285 
286 	if (status & (UART_LSR_BI | UART_LSR_PE |
287 		      UART_LSR_FE | UART_LSR_OE)) {
288 	  /*
289 	   * For statistics only
290 	   */
291 	  if (status & UART_LSR_BI) {
292 	    status &= ~(UART_LSR_FE | UART_LSR_PE);
293 	    icount->brk++;
294 	  } else if (status & UART_LSR_PE)
295 	    icount->parity++;
296 	  else if (status & UART_LSR_FE)
297 	    icount->frame++;
298 	  if (status & UART_LSR_OE)
299 	    icount->overrun++;
300 
301 	  /*
302 	   * Now check to see if character should be
303 	   * ignored, and mask off conditions which
304 	   * should be ignored.
305 	   */
306 	  if (status & info->ignore_status_mask)
307 	    goto out;
308 
309 	  status &= info->read_status_mask;
310 
311 	  if (status & (UART_LSR_BI)) {
312 #ifdef SERIAL_DEBUG_INTR
313 	    printk("handling break....");
314 #endif
315 	    flag = TTY_BREAK;
316 	    if (info->tport.flags & ASYNC_SAK)
317 	      do_SAK(tty);
318 	  } else if (status & UART_LSR_PE)
319 	    flag = TTY_PARITY;
320 	  else if (status & UART_LSR_FE)
321 	    flag = TTY_FRAME;
322 	  if (status & UART_LSR_OE) {
323 	    /*
324 	     * Overrun is special, since it's
325 	     * reported immediately, and doesn't
326 	     * affect the current character
327 	     */
328 	     oe = 1;
329 	  }
330 	}
331 	tty_insert_flip_char(tty, ch, flag);
332 	if (oe == 1)
333 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
334 	tty_flip_buffer_push(tty);
335 out:
336 	return;
337 }
338 
339 static void transmit_chars(struct serial_state *info)
340 {
341 	custom.intreq = IF_TBE;
342 	mb();
343 	if (info->x_char) {
344 	        custom.serdat = info->x_char | 0x100;
345 		mb();
346 		info->icount.tx++;
347 		info->x_char = 0;
348 		return;
349 	}
350 	if (info->xmit.head == info->xmit.tail
351 	    || info->tport.tty->stopped
352 	    || info->tport.tty->hw_stopped) {
353 		info->IER &= ~UART_IER_THRI;
354 	        custom.intena = IF_TBE;
355 		mb();
356 		return;
357 	}
358 
359 	custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
360 	mb();
361 	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
362 	info->icount.tx++;
363 
364 	if (CIRC_CNT(info->xmit.head,
365 		     info->xmit.tail,
366 		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
367 		tty_wakeup(info->tport.tty);
368 
369 #ifdef SERIAL_DEBUG_INTR
370 	printk("THRE...");
371 #endif
372 	if (info->xmit.head == info->xmit.tail) {
373 	        custom.intena = IF_TBE;
374 		mb();
375 		info->IER &= ~UART_IER_THRI;
376 	}
377 }
378 
379 static void check_modem_status(struct serial_state *info)
380 {
381 	struct tty_port *port = &info->tport;
382 	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
383 	unsigned char dstatus;
384 	struct	async_icount *icount;
385 
386 	/* Determine bits that have changed */
387 	dstatus = status ^ current_ctl_bits;
388 	current_ctl_bits = status;
389 
390 	if (dstatus) {
391 		icount = &info->icount;
392 		/* update input line counters */
393 		if (dstatus & SER_DSR)
394 			icount->dsr++;
395 		if (dstatus & SER_DCD) {
396 			icount->dcd++;
397 #ifdef CONFIG_HARD_PPS
398 			if ((port->flags & ASYNC_HARDPPS_CD) &&
399 			    !(status & SER_DCD))
400 				hardpps();
401 #endif
402 		}
403 		if (dstatus & SER_CTS)
404 			icount->cts++;
405 		wake_up_interruptible(&port->delta_msr_wait);
406 	}
407 
408 	if ((port->flags & ASYNC_CHECK_CD) && (dstatus & SER_DCD)) {
409 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
410 		printk("ttyS%d CD now %s...", info->line,
411 		       (!(status & SER_DCD)) ? "on" : "off");
412 #endif
413 		if (!(status & SER_DCD))
414 			wake_up_interruptible(&port->open_wait);
415 		else {
416 #ifdef SERIAL_DEBUG_OPEN
417 			printk("doing serial hangup...");
418 #endif
419 			if (port->tty)
420 				tty_hangup(port->tty);
421 		}
422 	}
423 	if (tty_port_cts_enabled(port)) {
424 		if (port->tty->hw_stopped) {
425 			if (!(status & SER_CTS)) {
426 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
427 				printk("CTS tx start...");
428 #endif
429 				port->tty->hw_stopped = 0;
430 				info->IER |= UART_IER_THRI;
431 				custom.intena = IF_SETCLR | IF_TBE;
432 				mb();
433 				/* set a pending Tx Interrupt, transmitter should restart now */
434 				custom.intreq = IF_SETCLR | IF_TBE;
435 				mb();
436 				tty_wakeup(port->tty);
437 				return;
438 			}
439 		} else {
440 			if ((status & SER_CTS)) {
441 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
442 				printk("CTS tx stop...");
443 #endif
444 				port->tty->hw_stopped = 1;
445 				info->IER &= ~UART_IER_THRI;
446 				/* disable Tx interrupt and remove any pending interrupts */
447 				custom.intena = IF_TBE;
448 				mb();
449 				custom.intreq = IF_TBE;
450 				mb();
451 			}
452 		}
453 	}
454 }
455 
456 static irqreturn_t ser_vbl_int( int irq, void *data)
457 {
458         /* vbl is just a periodic interrupt we tie into to update modem status */
459 	struct serial_state *info = data;
460 	/*
461 	 * TBD - is it better to unregister from this interrupt or to
462 	 * ignore it if MSI is clear ?
463 	 */
464 	if(info->IER & UART_IER_MSI)
465 	  check_modem_status(info);
466 	return IRQ_HANDLED;
467 }
468 
469 static irqreturn_t ser_rx_int(int irq, void *dev_id)
470 {
471 	struct serial_state *info = dev_id;
472 
473 #ifdef SERIAL_DEBUG_INTR
474 	printk("ser_rx_int...");
475 #endif
476 
477 	if (!info->tport.tty)
478 		return IRQ_NONE;
479 
480 	receive_chars(info);
481 #ifdef SERIAL_DEBUG_INTR
482 	printk("end.\n");
483 #endif
484 	return IRQ_HANDLED;
485 }
486 
487 static irqreturn_t ser_tx_int(int irq, void *dev_id)
488 {
489 	struct serial_state *info = dev_id;
490 
491 	if (custom.serdatr & SDR_TBE) {
492 #ifdef SERIAL_DEBUG_INTR
493 	  printk("ser_tx_int...");
494 #endif
495 
496 	  if (!info->tport.tty)
497 		return IRQ_NONE;
498 
499 	  transmit_chars(info);
500 #ifdef SERIAL_DEBUG_INTR
501 	  printk("end.\n");
502 #endif
503 	}
504 	return IRQ_HANDLED;
505 }
506 
507 /*
508  * -------------------------------------------------------------------
509  * Here ends the serial interrupt routines.
510  * -------------------------------------------------------------------
511  */
512 
513 /*
514  * ---------------------------------------------------------------
515  * Low level utility subroutines for the serial driver:  routines to
516  * figure out the appropriate timeout for an interrupt chain, routines
517  * to initialize and startup a serial port, and routines to shutdown a
518  * serial port.  Useful stuff like that.
519  * ---------------------------------------------------------------
520  */
521 
522 static int startup(struct tty_struct *tty, struct serial_state *info)
523 {
524 	struct tty_port *port = &info->tport;
525 	unsigned long flags;
526 	int	retval=0;
527 	unsigned long page;
528 
529 	page = get_zeroed_page(GFP_KERNEL);
530 	if (!page)
531 		return -ENOMEM;
532 
533 	local_irq_save(flags);
534 
535 	if (port->flags & ASYNC_INITIALIZED) {
536 		free_page(page);
537 		goto errout;
538 	}
539 
540 	if (info->xmit.buf)
541 		free_page(page);
542 	else
543 		info->xmit.buf = (unsigned char *) page;
544 
545 #ifdef SERIAL_DEBUG_OPEN
546 	printk("starting up ttys%d ...", info->line);
547 #endif
548 
549 	/* Clear anything in the input buffer */
550 
551 	custom.intreq = IF_RBF;
552 	mb();
553 
554 	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
555 	if (retval) {
556 	  if (serial_isroot()) {
557 	      set_bit(TTY_IO_ERROR, &tty->flags);
558 	    retval = 0;
559 	  }
560 	  goto errout;
561 	}
562 
563 	/* enable both Rx and Tx interrupts */
564 	custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
565 	mb();
566 	info->IER = UART_IER_MSI;
567 
568 	/* remember current state of the DCD and CTS bits */
569 	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
570 
571 	info->MCR = 0;
572 	if (C_BAUD(tty))
573 	  info->MCR = SER_DTR | SER_RTS;
574 	rtsdtr_ctrl(info->MCR);
575 
576 	clear_bit(TTY_IO_ERROR, &tty->flags);
577 	info->xmit.head = info->xmit.tail = 0;
578 
579 	/*
580 	 * Set up the tty->alt_speed kludge
581 	 */
582 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
583 		tty->alt_speed = 57600;
584 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
585 		tty->alt_speed = 115200;
586 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
587 		tty->alt_speed = 230400;
588 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
589 		tty->alt_speed = 460800;
590 
591 	/*
592 	 * and set the speed of the serial port
593 	 */
594 	change_speed(tty, info, NULL);
595 
596 	port->flags |= ASYNC_INITIALIZED;
597 	local_irq_restore(flags);
598 	return 0;
599 
600 errout:
601 	local_irq_restore(flags);
602 	return retval;
603 }
604 
605 /*
606  * This routine will shutdown a serial port; interrupts are disabled, and
607  * DTR is dropped if the hangup on close termio flag is on.
608  */
609 static void shutdown(struct tty_struct *tty, struct serial_state *info)
610 {
611 	unsigned long	flags;
612 	struct serial_state *state;
613 
614 	if (!(info->tport.flags & ASYNC_INITIALIZED))
615 		return;
616 
617 	state = info;
618 
619 #ifdef SERIAL_DEBUG_OPEN
620 	printk("Shutting down serial port %d ....\n", info->line);
621 #endif
622 
623 	local_irq_save(flags); /* Disable interrupts */
624 
625 	/*
626 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
627 	 * here so the queue might never be waken up
628 	 */
629 	wake_up_interruptible(&info->tport.delta_msr_wait);
630 
631 	/*
632 	 * Free the IRQ, if necessary
633 	 */
634 	free_irq(IRQ_AMIGA_VERTB, info);
635 
636 	if (info->xmit.buf) {
637 		free_page((unsigned long) info->xmit.buf);
638 		info->xmit.buf = NULL;
639 	}
640 
641 	info->IER = 0;
642 	custom.intena = IF_RBF | IF_TBE;
643 	mb();
644 
645 	/* disable break condition */
646 	custom.adkcon = AC_UARTBRK;
647 	mb();
648 
649 	if (tty->termios.c_cflag & HUPCL)
650 		info->MCR &= ~(SER_DTR|SER_RTS);
651 	rtsdtr_ctrl(info->MCR);
652 
653 	set_bit(TTY_IO_ERROR, &tty->flags);
654 
655 	info->tport.flags &= ~ASYNC_INITIALIZED;
656 	local_irq_restore(flags);
657 }
658 
659 
660 /*
661  * This routine is called to set the UART divisor registers to match
662  * the specified baud rate for a serial port.
663  */
664 static void change_speed(struct tty_struct *tty, struct serial_state *info,
665 			 struct ktermios *old_termios)
666 {
667 	struct tty_port *port = &info->tport;
668 	int	quot = 0, baud_base, baud;
669 	unsigned cflag, cval = 0;
670 	int	bits;
671 	unsigned long	flags;
672 
673 	cflag = tty->termios.c_cflag;
674 
675 	/* Byte size is always 8 bits plus parity bit if requested */
676 
677 	cval = 3; bits = 10;
678 	if (cflag & CSTOPB) {
679 		cval |= 0x04;
680 		bits++;
681 	}
682 	if (cflag & PARENB) {
683 		cval |= UART_LCR_PARITY;
684 		bits++;
685 	}
686 	if (!(cflag & PARODD))
687 		cval |= UART_LCR_EPAR;
688 #ifdef CMSPAR
689 	if (cflag & CMSPAR)
690 		cval |= UART_LCR_SPAR;
691 #endif
692 
693 	/* Determine divisor based on baud rate */
694 	baud = tty_get_baud_rate(tty);
695 	if (!baud)
696 		baud = 9600;	/* B0 transition handled in rs_set_termios */
697 	baud_base = info->baud_base;
698 	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
699 		quot = info->custom_divisor;
700 	else {
701 		if (baud == 134)
702 			/* Special case since 134 is really 134.5 */
703 			quot = (2*baud_base / 269);
704 		else if (baud)
705 			quot = baud_base / baud;
706 	}
707 	/* If the quotient is zero refuse the change */
708 	if (!quot && old_termios) {
709 		/* FIXME: Will need updating for new tty in the end */
710 		tty->termios.c_cflag &= ~CBAUD;
711 		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
712 		baud = tty_get_baud_rate(tty);
713 		if (!baud)
714 			baud = 9600;
715 		if (baud == 38400 &&
716 		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
717 			quot = info->custom_divisor;
718 		else {
719 			if (baud == 134)
720 				/* Special case since 134 is really 134.5 */
721 				quot = (2*baud_base / 269);
722 			else if (baud)
723 				quot = baud_base / baud;
724 		}
725 	}
726 	/* As a last resort, if the quotient is zero, default to 9600 bps */
727 	if (!quot)
728 		quot = baud_base / 9600;
729 	info->quot = quot;
730 	info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
731 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
732 
733 	/* CTS flow control flag and modem status interrupts */
734 	info->IER &= ~UART_IER_MSI;
735 	if (port->flags & ASYNC_HARDPPS_CD)
736 		info->IER |= UART_IER_MSI;
737 	if (cflag & CRTSCTS) {
738 		port->flags |= ASYNC_CTS_FLOW;
739 		info->IER |= UART_IER_MSI;
740 	} else
741 		port->flags &= ~ASYNC_CTS_FLOW;
742 	if (cflag & CLOCAL)
743 		port->flags &= ~ASYNC_CHECK_CD;
744 	else {
745 		port->flags |= ASYNC_CHECK_CD;
746 		info->IER |= UART_IER_MSI;
747 	}
748 	/* TBD:
749 	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
750 	 */
751 
752 	/*
753 	 * Set up parity check flag
754 	 */
755 
756 	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
757 	if (I_INPCK(tty))
758 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
759 	if (I_BRKINT(tty) || I_PARMRK(tty))
760 		info->read_status_mask |= UART_LSR_BI;
761 
762 	/*
763 	 * Characters to ignore
764 	 */
765 	info->ignore_status_mask = 0;
766 	if (I_IGNPAR(tty))
767 		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
768 	if (I_IGNBRK(tty)) {
769 		info->ignore_status_mask |= UART_LSR_BI;
770 		/*
771 		 * If we're ignore parity and break indicators, ignore
772 		 * overruns too.  (For real raw support).
773 		 */
774 		if (I_IGNPAR(tty))
775 			info->ignore_status_mask |= UART_LSR_OE;
776 	}
777 	/*
778 	 * !!! ignore all characters if CREAD is not set
779 	 */
780 	if ((cflag & CREAD) == 0)
781 		info->ignore_status_mask |= UART_LSR_DR;
782 	local_irq_save(flags);
783 
784 	{
785 	  short serper;
786 
787 	/* Set up the baud rate */
788 	  serper = quot - 1;
789 
790 	/* Enable or disable parity bit */
791 
792 	if(cval & UART_LCR_PARITY)
793 	  serper |= (SERPER_PARENB);
794 
795 	custom.serper = serper;
796 	mb();
797 	}
798 
799 	local_irq_restore(flags);
800 }
801 
802 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
803 {
804 	struct serial_state *info;
805 	unsigned long flags;
806 
807 	info = tty->driver_data;
808 
809 	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
810 		return 0;
811 
812 	if (!info->xmit.buf)
813 		return 0;
814 
815 	local_irq_save(flags);
816 	if (CIRC_SPACE(info->xmit.head,
817 		       info->xmit.tail,
818 		       SERIAL_XMIT_SIZE) == 0) {
819 		local_irq_restore(flags);
820 		return 0;
821 	}
822 
823 	info->xmit.buf[info->xmit.head++] = ch;
824 	info->xmit.head &= SERIAL_XMIT_SIZE-1;
825 	local_irq_restore(flags);
826 	return 1;
827 }
828 
829 static void rs_flush_chars(struct tty_struct *tty)
830 {
831 	struct serial_state *info = tty->driver_data;
832 	unsigned long flags;
833 
834 	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
835 		return;
836 
837 	if (info->xmit.head == info->xmit.tail
838 	    || tty->stopped
839 	    || tty->hw_stopped
840 	    || !info->xmit.buf)
841 		return;
842 
843 	local_irq_save(flags);
844 	info->IER |= UART_IER_THRI;
845 	custom.intena = IF_SETCLR | IF_TBE;
846 	mb();
847 	/* set a pending Tx Interrupt, transmitter should restart now */
848 	custom.intreq = IF_SETCLR | IF_TBE;
849 	mb();
850 	local_irq_restore(flags);
851 }
852 
853 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
854 {
855 	int	c, ret = 0;
856 	struct serial_state *info = tty->driver_data;
857 	unsigned long flags;
858 
859 	if (serial_paranoia_check(info, tty->name, "rs_write"))
860 		return 0;
861 
862 	if (!info->xmit.buf)
863 		return 0;
864 
865 	local_irq_save(flags);
866 	while (1) {
867 		c = CIRC_SPACE_TO_END(info->xmit.head,
868 				      info->xmit.tail,
869 				      SERIAL_XMIT_SIZE);
870 		if (count < c)
871 			c = count;
872 		if (c <= 0) {
873 			break;
874 		}
875 		memcpy(info->xmit.buf + info->xmit.head, buf, c);
876 		info->xmit.head = ((info->xmit.head + c) &
877 				   (SERIAL_XMIT_SIZE-1));
878 		buf += c;
879 		count -= c;
880 		ret += c;
881 	}
882 	local_irq_restore(flags);
883 
884 	if (info->xmit.head != info->xmit.tail
885 	    && !tty->stopped
886 	    && !tty->hw_stopped
887 	    && !(info->IER & UART_IER_THRI)) {
888 		info->IER |= UART_IER_THRI;
889 		local_irq_disable();
890 		custom.intena = IF_SETCLR | IF_TBE;
891 		mb();
892 		/* set a pending Tx Interrupt, transmitter should restart now */
893 		custom.intreq = IF_SETCLR | IF_TBE;
894 		mb();
895 		local_irq_restore(flags);
896 	}
897 	return ret;
898 }
899 
900 static int rs_write_room(struct tty_struct *tty)
901 {
902 	struct serial_state *info = tty->driver_data;
903 
904 	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
905 		return 0;
906 	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
907 }
908 
909 static int rs_chars_in_buffer(struct tty_struct *tty)
910 {
911 	struct serial_state *info = tty->driver_data;
912 
913 	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
914 		return 0;
915 	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
916 }
917 
918 static void rs_flush_buffer(struct tty_struct *tty)
919 {
920 	struct serial_state *info = tty->driver_data;
921 	unsigned long flags;
922 
923 	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
924 		return;
925 	local_irq_save(flags);
926 	info->xmit.head = info->xmit.tail = 0;
927 	local_irq_restore(flags);
928 	tty_wakeup(tty);
929 }
930 
931 /*
932  * This function is used to send a high-priority XON/XOFF character to
933  * the device
934  */
935 static void rs_send_xchar(struct tty_struct *tty, char ch)
936 {
937 	struct serial_state *info = tty->driver_data;
938         unsigned long flags;
939 
940 	if (serial_paranoia_check(info, tty->name, "rs_send_char"))
941 		return;
942 
943 	info->x_char = ch;
944 	if (ch) {
945 		/* Make sure transmit interrupts are on */
946 
947 	        /* Check this ! */
948 	        local_irq_save(flags);
949 		if(!(custom.intenar & IF_TBE)) {
950 		    custom.intena = IF_SETCLR | IF_TBE;
951 		    mb();
952 		    /* set a pending Tx Interrupt, transmitter should restart now */
953 		    custom.intreq = IF_SETCLR | IF_TBE;
954 		    mb();
955 		}
956 		local_irq_restore(flags);
957 
958 		info->IER |= UART_IER_THRI;
959 	}
960 }
961 
962 /*
963  * ------------------------------------------------------------
964  * rs_throttle()
965  *
966  * This routine is called by the upper-layer tty layer to signal that
967  * incoming characters should be throttled.
968  * ------------------------------------------------------------
969  */
970 static void rs_throttle(struct tty_struct * tty)
971 {
972 	struct serial_state *info = tty->driver_data;
973 	unsigned long flags;
974 #ifdef SERIAL_DEBUG_THROTTLE
975 	char	buf[64];
976 
977 	printk("throttle %s: %d....\n", tty_name(tty, buf),
978 	       tty->ldisc.chars_in_buffer(tty));
979 #endif
980 
981 	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
982 		return;
983 
984 	if (I_IXOFF(tty))
985 		rs_send_xchar(tty, STOP_CHAR(tty));
986 
987 	if (tty->termios.c_cflag & CRTSCTS)
988 		info->MCR &= ~SER_RTS;
989 
990 	local_irq_save(flags);
991 	rtsdtr_ctrl(info->MCR);
992 	local_irq_restore(flags);
993 }
994 
995 static void rs_unthrottle(struct tty_struct * tty)
996 {
997 	struct serial_state *info = tty->driver_data;
998 	unsigned long flags;
999 #ifdef SERIAL_DEBUG_THROTTLE
1000 	char	buf[64];
1001 
1002 	printk("unthrottle %s: %d....\n", tty_name(tty, buf),
1003 	       tty->ldisc.chars_in_buffer(tty));
1004 #endif
1005 
1006 	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
1007 		return;
1008 
1009 	if (I_IXOFF(tty)) {
1010 		if (info->x_char)
1011 			info->x_char = 0;
1012 		else
1013 			rs_send_xchar(tty, START_CHAR(tty));
1014 	}
1015 	if (tty->termios.c_cflag & CRTSCTS)
1016 		info->MCR |= SER_RTS;
1017 	local_irq_save(flags);
1018 	rtsdtr_ctrl(info->MCR);
1019 	local_irq_restore(flags);
1020 }
1021 
1022 /*
1023  * ------------------------------------------------------------
1024  * rs_ioctl() and friends
1025  * ------------------------------------------------------------
1026  */
1027 
1028 static int get_serial_info(struct tty_struct *tty, struct serial_state *state,
1029 			   struct serial_struct __user * retinfo)
1030 {
1031 	struct serial_struct tmp;
1032 
1033 	if (!retinfo)
1034 		return -EFAULT;
1035 	memset(&tmp, 0, sizeof(tmp));
1036 	tty_lock(tty);
1037 	tmp.line = tty->index;
1038 	tmp.port = state->port;
1039 	tmp.flags = state->tport.flags;
1040 	tmp.xmit_fifo_size = state->xmit_fifo_size;
1041 	tmp.baud_base = state->baud_base;
1042 	tmp.close_delay = state->tport.close_delay;
1043 	tmp.closing_wait = state->tport.closing_wait;
1044 	tmp.custom_divisor = state->custom_divisor;
1045 	tty_unlock(tty);
1046 	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
1047 		return -EFAULT;
1048 	return 0;
1049 }
1050 
1051 static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
1052 			   struct serial_struct __user * new_info)
1053 {
1054 	struct tty_port *port = &state->tport;
1055 	struct serial_struct new_serial;
1056 	bool change_spd;
1057 	int 			retval = 0;
1058 
1059 	if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
1060 		return -EFAULT;
1061 
1062 	tty_lock(tty);
1063 	change_spd = ((new_serial.flags ^ port->flags) & ASYNC_SPD_MASK) ||
1064 		new_serial.custom_divisor != state->custom_divisor;
1065 	if (new_serial.irq || new_serial.port != state->port ||
1066 			new_serial.xmit_fifo_size != state->xmit_fifo_size) {
1067 		tty_unlock(tty);
1068 		return -EINVAL;
1069 	}
1070 
1071 	if (!serial_isroot()) {
1072 		if ((new_serial.baud_base != state->baud_base) ||
1073 		    (new_serial.close_delay != port->close_delay) ||
1074 		    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
1075 		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
1076 		     (port->flags & ~ASYNC_USR_MASK))) {
1077 			tty_unlock(tty);
1078 			return -EPERM;
1079 		}
1080 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
1081 			       (new_serial.flags & ASYNC_USR_MASK));
1082 		state->custom_divisor = new_serial.custom_divisor;
1083 		goto check_and_exit;
1084 	}
1085 
1086 	if (new_serial.baud_base < 9600) {
1087 		tty_unlock(tty);
1088 		return -EINVAL;
1089 	}
1090 
1091 	/*
1092 	 * OK, past this point, all the error checking has been done.
1093 	 * At this point, we start making changes.....
1094 	 */
1095 
1096 	state->baud_base = new_serial.baud_base;
1097 	port->flags = ((port->flags & ~ASYNC_FLAGS) |
1098 			(new_serial.flags & ASYNC_FLAGS));
1099 	state->custom_divisor = new_serial.custom_divisor;
1100 	port->close_delay = new_serial.close_delay * HZ/100;
1101 	port->closing_wait = new_serial.closing_wait * HZ/100;
1102 	tty->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1103 
1104 check_and_exit:
1105 	if (port->flags & ASYNC_INITIALIZED) {
1106 		if (change_spd) {
1107 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
1108 				tty->alt_speed = 57600;
1109 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
1110 				tty->alt_speed = 115200;
1111 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
1112 				tty->alt_speed = 230400;
1113 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
1114 				tty->alt_speed = 460800;
1115 			change_speed(tty, state, NULL);
1116 		}
1117 	} else
1118 		retval = startup(tty, state);
1119 	tty_unlock(tty);
1120 	return retval;
1121 }
1122 
1123 
1124 /*
1125  * get_lsr_info - get line status register info
1126  *
1127  * Purpose: Let user call ioctl() to get info when the UART physically
1128  * 	    is emptied.  On bus types like RS485, the transmitter must
1129  * 	    release the bus after transmitting. This must be done when
1130  * 	    the transmit shift register is empty, not be done when the
1131  * 	    transmit holding register is empty.  This functionality
1132  * 	    allows an RS485 driver to be written in user space.
1133  */
1134 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
1135 {
1136 	unsigned char status;
1137 	unsigned int result;
1138 	unsigned long flags;
1139 
1140 	local_irq_save(flags);
1141 	status = custom.serdatr;
1142 	mb();
1143 	local_irq_restore(flags);
1144 	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1145 	if (copy_to_user(value, &result, sizeof(int)))
1146 		return -EFAULT;
1147 	return 0;
1148 }
1149 
1150 
1151 static int rs_tiocmget(struct tty_struct *tty)
1152 {
1153 	struct serial_state *info = tty->driver_data;
1154 	unsigned char control, status;
1155 	unsigned long flags;
1156 
1157 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1158 		return -ENODEV;
1159 	if (tty->flags & (1 << TTY_IO_ERROR))
1160 		return -EIO;
1161 
1162 	control = info->MCR;
1163 	local_irq_save(flags);
1164 	status = ciab.pra;
1165 	local_irq_restore(flags);
1166 	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1167 		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1168 		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1169 		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1170 		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1171 }
1172 
1173 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1174 						unsigned int clear)
1175 {
1176 	struct serial_state *info = tty->driver_data;
1177 	unsigned long flags;
1178 
1179 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1180 		return -ENODEV;
1181 	if (tty->flags & (1 << TTY_IO_ERROR))
1182 		return -EIO;
1183 
1184 	local_irq_save(flags);
1185 	if (set & TIOCM_RTS)
1186 		info->MCR |= SER_RTS;
1187 	if (set & TIOCM_DTR)
1188 		info->MCR |= SER_DTR;
1189 	if (clear & TIOCM_RTS)
1190 		info->MCR &= ~SER_RTS;
1191 	if (clear & TIOCM_DTR)
1192 		info->MCR &= ~SER_DTR;
1193 	rtsdtr_ctrl(info->MCR);
1194 	local_irq_restore(flags);
1195 	return 0;
1196 }
1197 
1198 /*
1199  * rs_break() --- routine which turns the break handling on or off
1200  */
1201 static int rs_break(struct tty_struct *tty, int break_state)
1202 {
1203 	struct serial_state *info = tty->driver_data;
1204 	unsigned long flags;
1205 
1206 	if (serial_paranoia_check(info, tty->name, "rs_break"))
1207 		return -EINVAL;
1208 
1209 	local_irq_save(flags);
1210 	if (break_state == -1)
1211 	  custom.adkcon = AC_SETCLR | AC_UARTBRK;
1212 	else
1213 	  custom.adkcon = AC_UARTBRK;
1214 	mb();
1215 	local_irq_restore(flags);
1216 	return 0;
1217 }
1218 
1219 /*
1220  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1221  * Return: write counters to the user passed counter struct
1222  * NB: both 1->0 and 0->1 transitions are counted except for
1223  *     RI where only 0->1 is counted.
1224  */
1225 static int rs_get_icount(struct tty_struct *tty,
1226 				struct serial_icounter_struct *icount)
1227 {
1228 	struct serial_state *info = tty->driver_data;
1229 	struct async_icount cnow;
1230 	unsigned long flags;
1231 
1232 	local_irq_save(flags);
1233 	cnow = info->icount;
1234 	local_irq_restore(flags);
1235 	icount->cts = cnow.cts;
1236 	icount->dsr = cnow.dsr;
1237 	icount->rng = cnow.rng;
1238 	icount->dcd = cnow.dcd;
1239 	icount->rx = cnow.rx;
1240 	icount->tx = cnow.tx;
1241 	icount->frame = cnow.frame;
1242 	icount->overrun = cnow.overrun;
1243 	icount->parity = cnow.parity;
1244 	icount->brk = cnow.brk;
1245 	icount->buf_overrun = cnow.buf_overrun;
1246 
1247 	return 0;
1248 }
1249 
1250 static int rs_ioctl(struct tty_struct *tty,
1251 		    unsigned int cmd, unsigned long arg)
1252 {
1253 	struct serial_state *info = tty->driver_data;
1254 	struct async_icount cprev, cnow;	/* kernel counter temps */
1255 	void __user *argp = (void __user *)arg;
1256 	unsigned long flags;
1257 
1258 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1259 		return -ENODEV;
1260 
1261 	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1262 	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
1263 	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1264 		if (tty->flags & (1 << TTY_IO_ERROR))
1265 		    return -EIO;
1266 	}
1267 
1268 	switch (cmd) {
1269 		case TIOCGSERIAL:
1270 			return get_serial_info(tty, info, argp);
1271 		case TIOCSSERIAL:
1272 			return set_serial_info(tty, info, argp);
1273 		case TIOCSERCONFIG:
1274 			return 0;
1275 
1276 		case TIOCSERGETLSR: /* Get line status register */
1277 			return get_lsr_info(info, argp);
1278 
1279 		case TIOCSERGSTRUCT:
1280 			if (copy_to_user(argp,
1281 					 info, sizeof(struct serial_state)))
1282 				return -EFAULT;
1283 			return 0;
1284 
1285 		/*
1286 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1287 		 * - mask passed in arg for lines of interest
1288  		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1289 		 * Caller should use TIOCGICOUNT to see which one it was
1290 		 */
1291 		case TIOCMIWAIT:
1292 			local_irq_save(flags);
1293 			/* note the counters on entry */
1294 			cprev = info->icount;
1295 			local_irq_restore(flags);
1296 			while (1) {
1297 				interruptible_sleep_on(&info->tport.delta_msr_wait);
1298 				/* see if a signal did it */
1299 				if (signal_pending(current))
1300 					return -ERESTARTSYS;
1301 				local_irq_save(flags);
1302 				cnow = info->icount; /* atomic copy */
1303 				local_irq_restore(flags);
1304 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1305 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
1306 					return -EIO; /* no change => error */
1307 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1308 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1309 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1310 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1311 					return 0;
1312 				}
1313 				cprev = cnow;
1314 			}
1315 			/* NOTREACHED */
1316 
1317 		case TIOCSERGWILD:
1318 		case TIOCSERSWILD:
1319 			/* "setserial -W" is called in Debian boot */
1320 			printk ("TIOCSER?WILD ioctl obsolete, ignored.\n");
1321 			return 0;
1322 
1323 		default:
1324 			return -ENOIOCTLCMD;
1325 		}
1326 	return 0;
1327 }
1328 
1329 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1330 {
1331 	struct serial_state *info = tty->driver_data;
1332 	unsigned long flags;
1333 	unsigned int cflag = tty->termios.c_cflag;
1334 
1335 	change_speed(tty, info, old_termios);
1336 
1337 	/* Handle transition to B0 status */
1338 	if ((old_termios->c_cflag & CBAUD) &&
1339 	    !(cflag & CBAUD)) {
1340 		info->MCR &= ~(SER_DTR|SER_RTS);
1341 		local_irq_save(flags);
1342 		rtsdtr_ctrl(info->MCR);
1343 		local_irq_restore(flags);
1344 	}
1345 
1346 	/* Handle transition away from B0 status */
1347 	if (!(old_termios->c_cflag & CBAUD) &&
1348 	    (cflag & CBAUD)) {
1349 		info->MCR |= SER_DTR;
1350 		if (!(tty->termios.c_cflag & CRTSCTS) ||
1351 		    !test_bit(TTY_THROTTLED, &tty->flags)) {
1352 			info->MCR |= SER_RTS;
1353 		}
1354 		local_irq_save(flags);
1355 		rtsdtr_ctrl(info->MCR);
1356 		local_irq_restore(flags);
1357 	}
1358 
1359 	/* Handle turning off CRTSCTS */
1360 	if ((old_termios->c_cflag & CRTSCTS) &&
1361 	    !(tty->termios.c_cflag & CRTSCTS)) {
1362 		tty->hw_stopped = 0;
1363 		rs_start(tty);
1364 	}
1365 
1366 #if 0
1367 	/*
1368 	 * No need to wake up processes in open wait, since they
1369 	 * sample the CLOCAL flag once, and don't recheck it.
1370 	 * XXX  It's not clear whether the current behavior is correct
1371 	 * or not.  Hence, this may change.....
1372 	 */
1373 	if (!(old_termios->c_cflag & CLOCAL) &&
1374 	    (tty->termios.c_cflag & CLOCAL))
1375 		wake_up_interruptible(&info->open_wait);
1376 #endif
1377 }
1378 
1379 /*
1380  * ------------------------------------------------------------
1381  * rs_close()
1382  *
1383  * This routine is called when the serial port gets closed.  First, we
1384  * wait for the last remaining data to be sent.  Then, we unlink its
1385  * async structure from the interrupt chain if necessary, and we free
1386  * that IRQ if nothing is left in the chain.
1387  * ------------------------------------------------------------
1388  */
1389 static void rs_close(struct tty_struct *tty, struct file * filp)
1390 {
1391 	struct serial_state *state = tty->driver_data;
1392 	struct tty_port *port = &state->tport;
1393 
1394 	if (serial_paranoia_check(state, tty->name, "rs_close"))
1395 		return;
1396 
1397 	if (tty_port_close_start(port, tty, filp) == 0)
1398 		return;
1399 
1400 	/*
1401 	 * At this point we stop accepting input.  To do this, we
1402 	 * disable the receive line status interrupts, and tell the
1403 	 * interrupt driver to stop checking the data ready bit in the
1404 	 * line status register.
1405 	 */
1406 	state->read_status_mask &= ~UART_LSR_DR;
1407 	if (port->flags & ASYNC_INITIALIZED) {
1408 	        /* disable receive interrupts */
1409 	        custom.intena = IF_RBF;
1410 		mb();
1411 		/* clear any pending receive interrupt */
1412 		custom.intreq = IF_RBF;
1413 		mb();
1414 
1415 		/*
1416 		 * Before we drop DTR, make sure the UART transmitter
1417 		 * has completely drained; this is especially
1418 		 * important if there is a transmit FIFO!
1419 		 */
1420 		rs_wait_until_sent(tty, state->timeout);
1421 	}
1422 	shutdown(tty, state);
1423 	rs_flush_buffer(tty);
1424 
1425 	tty_ldisc_flush(tty);
1426 	port->tty = NULL;
1427 
1428 	tty_port_close_end(port, tty);
1429 }
1430 
1431 /*
1432  * rs_wait_until_sent() --- wait until the transmitter is empty
1433  */
1434 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1435 {
1436 	struct serial_state *info = tty->driver_data;
1437 	unsigned long orig_jiffies, char_time;
1438 	int lsr;
1439 
1440 	if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1441 		return;
1442 
1443 	if (info->xmit_fifo_size == 0)
1444 		return; /* Just in case.... */
1445 
1446 	orig_jiffies = jiffies;
1447 
1448 	/*
1449 	 * Set the check interval to be 1/5 of the estimated time to
1450 	 * send a single character, and make it at least 1.  The check
1451 	 * interval should also be less than the timeout.
1452 	 *
1453 	 * Note: we have to use pretty tight timings here to satisfy
1454 	 * the NIST-PCTS.
1455 	 */
1456 	char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1457 	char_time = char_time / 5;
1458 	if (char_time == 0)
1459 		char_time = 1;
1460 	if (timeout)
1461 	  char_time = min_t(unsigned long, char_time, timeout);
1462 	/*
1463 	 * If the transmitter hasn't cleared in twice the approximate
1464 	 * amount of time to send the entire FIFO, it probably won't
1465 	 * ever clear.  This assumes the UART isn't doing flow
1466 	 * control, which is currently the case.  Hence, if it ever
1467 	 * takes longer than info->timeout, this is probably due to a
1468 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1469 	 * 2*info->timeout.
1470 	 */
1471 	if (!timeout || timeout > 2*info->timeout)
1472 		timeout = 2*info->timeout;
1473 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1474 	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1475 	printk("jiff=%lu...", jiffies);
1476 #endif
1477 	while(!((lsr = custom.serdatr) & SDR_TSRE)) {
1478 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1479 		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1480 #endif
1481 		msleep_interruptible(jiffies_to_msecs(char_time));
1482 		if (signal_pending(current))
1483 			break;
1484 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1485 			break;
1486 	}
1487 	__set_current_state(TASK_RUNNING);
1488 
1489 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1490 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1491 #endif
1492 }
1493 
1494 /*
1495  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1496  */
1497 static void rs_hangup(struct tty_struct *tty)
1498 {
1499 	struct serial_state *info = tty->driver_data;
1500 
1501 	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1502 		return;
1503 
1504 	rs_flush_buffer(tty);
1505 	shutdown(tty, info);
1506 	info->tport.count = 0;
1507 	info->tport.flags &= ~ASYNC_NORMAL_ACTIVE;
1508 	info->tport.tty = NULL;
1509 	wake_up_interruptible(&info->tport.open_wait);
1510 }
1511 
1512 /*
1513  * This routine is called whenever a serial port is opened.  It
1514  * enables interrupts for a serial port, linking in its async structure into
1515  * the IRQ chain.   It also performs the serial-specific
1516  * initialization for the tty structure.
1517  */
1518 static int rs_open(struct tty_struct *tty, struct file * filp)
1519 {
1520 	struct serial_state *info = rs_table + tty->index;
1521 	struct tty_port *port = &info->tport;
1522 	int retval;
1523 
1524 	port->count++;
1525 	port->tty = tty;
1526 	tty->driver_data = info;
1527 	tty->port = port;
1528 	if (serial_paranoia_check(info, tty->name, "rs_open"))
1529 		return -ENODEV;
1530 
1531 	tty->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1532 
1533 	retval = startup(tty, info);
1534 	if (retval) {
1535 		return retval;
1536 	}
1537 
1538 	return tty_port_block_til_ready(port, tty, filp);
1539 }
1540 
1541 /*
1542  * /proc fs routines....
1543  */
1544 
1545 static inline void line_info(struct seq_file *m, int line,
1546 		struct serial_state *state)
1547 {
1548 	char	stat_buf[30], control, status;
1549 	unsigned long flags;
1550 
1551 	seq_printf(m, "%d: uart:amiga_builtin", line);
1552 
1553 	local_irq_save(flags);
1554 	status = ciab.pra;
1555 	control = (state->tport.flags & ASYNC_INITIALIZED) ? state->MCR : status;
1556 	local_irq_restore(flags);
1557 
1558 	stat_buf[0] = 0;
1559 	stat_buf[1] = 0;
1560 	if(!(control & SER_RTS))
1561 		strcat(stat_buf, "|RTS");
1562 	if(!(status & SER_CTS))
1563 		strcat(stat_buf, "|CTS");
1564 	if(!(control & SER_DTR))
1565 		strcat(stat_buf, "|DTR");
1566 	if(!(status & SER_DSR))
1567 		strcat(stat_buf, "|DSR");
1568 	if(!(status & SER_DCD))
1569 		strcat(stat_buf, "|CD");
1570 
1571 	if (state->quot)
1572 		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1573 
1574 	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1575 
1576 	if (state->icount.frame)
1577 		seq_printf(m, " fe:%d", state->icount.frame);
1578 
1579 	if (state->icount.parity)
1580 		seq_printf(m, " pe:%d", state->icount.parity);
1581 
1582 	if (state->icount.brk)
1583 		seq_printf(m, " brk:%d", state->icount.brk);
1584 
1585 	if (state->icount.overrun)
1586 		seq_printf(m, " oe:%d", state->icount.overrun);
1587 
1588 	/*
1589 	 * Last thing is the RS-232 status lines
1590 	 */
1591 	seq_printf(m, " %s\n", stat_buf+1);
1592 }
1593 
1594 static int rs_proc_show(struct seq_file *m, void *v)
1595 {
1596 	seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
1597 	line_info(m, 0, &rs_table[0]);
1598 	return 0;
1599 }
1600 
1601 static int rs_proc_open(struct inode *inode, struct file *file)
1602 {
1603 	return single_open(file, rs_proc_show, NULL);
1604 }
1605 
1606 static const struct file_operations rs_proc_fops = {
1607 	.owner		= THIS_MODULE,
1608 	.open		= rs_proc_open,
1609 	.read		= seq_read,
1610 	.llseek		= seq_lseek,
1611 	.release	= single_release,
1612 };
1613 
1614 /*
1615  * ---------------------------------------------------------------------
1616  * rs_init() and friends
1617  *
1618  * rs_init() is called at boot-time to initialize the serial driver.
1619  * ---------------------------------------------------------------------
1620  */
1621 
1622 /*
1623  * This routine prints out the appropriate serial driver version
1624  * number, and identifies which options were configured into this
1625  * driver.
1626  */
1627 static void show_serial_version(void)
1628 {
1629  	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
1630 }
1631 
1632 
1633 static const struct tty_operations serial_ops = {
1634 	.open = rs_open,
1635 	.close = rs_close,
1636 	.write = rs_write,
1637 	.put_char = rs_put_char,
1638 	.flush_chars = rs_flush_chars,
1639 	.write_room = rs_write_room,
1640 	.chars_in_buffer = rs_chars_in_buffer,
1641 	.flush_buffer = rs_flush_buffer,
1642 	.ioctl = rs_ioctl,
1643 	.throttle = rs_throttle,
1644 	.unthrottle = rs_unthrottle,
1645 	.set_termios = rs_set_termios,
1646 	.stop = rs_stop,
1647 	.start = rs_start,
1648 	.hangup = rs_hangup,
1649 	.break_ctl = rs_break,
1650 	.send_xchar = rs_send_xchar,
1651 	.wait_until_sent = rs_wait_until_sent,
1652 	.tiocmget = rs_tiocmget,
1653 	.tiocmset = rs_tiocmset,
1654 	.get_icount = rs_get_icount,
1655 	.proc_fops = &rs_proc_fops,
1656 };
1657 
1658 static int amiga_carrier_raised(struct tty_port *port)
1659 {
1660 	return !(ciab.pra & SER_DCD);
1661 }
1662 
1663 static void amiga_dtr_rts(struct tty_port *port, int raise)
1664 {
1665 	struct serial_state *info = container_of(port, struct serial_state,
1666 			tport);
1667 	unsigned long flags;
1668 
1669 	if (raise)
1670 		info->MCR |= SER_DTR|SER_RTS;
1671 	else
1672 		info->MCR &= ~(SER_DTR|SER_RTS);
1673 
1674 	local_irq_save(flags);
1675 	rtsdtr_ctrl(info->MCR);
1676 	local_irq_restore(flags);
1677 }
1678 
1679 static const struct tty_port_operations amiga_port_ops = {
1680 	.carrier_raised = amiga_carrier_raised,
1681 	.dtr_rts = amiga_dtr_rts,
1682 };
1683 
1684 /*
1685  * The serial driver boot-time initialization code!
1686  */
1687 static int __init amiga_serial_probe(struct platform_device *pdev)
1688 {
1689 	unsigned long flags;
1690 	struct serial_state * state;
1691 	int error;
1692 
1693 	serial_driver = alloc_tty_driver(NR_PORTS);
1694 	if (!serial_driver)
1695 		return -ENOMEM;
1696 
1697 	show_serial_version();
1698 
1699 	/* Initialize the tty_driver structure */
1700 
1701 	serial_driver->driver_name = "amiserial";
1702 	serial_driver->name = "ttyS";
1703 	serial_driver->major = TTY_MAJOR;
1704 	serial_driver->minor_start = 64;
1705 	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1706 	serial_driver->subtype = SERIAL_TYPE_NORMAL;
1707 	serial_driver->init_termios = tty_std_termios;
1708 	serial_driver->init_termios.c_cflag =
1709 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1710 	serial_driver->flags = TTY_DRIVER_REAL_RAW;
1711 	tty_set_operations(serial_driver, &serial_ops);
1712 
1713 	state = rs_table;
1714 	state->port = (int)&custom.serdatr; /* Just to give it a value */
1715 	state->custom_divisor = 0;
1716 	state->icount.cts = state->icount.dsr =
1717 	  state->icount.rng = state->icount.dcd = 0;
1718 	state->icount.rx = state->icount.tx = 0;
1719 	state->icount.frame = state->icount.parity = 0;
1720 	state->icount.overrun = state->icount.brk = 0;
1721 	tty_port_init(&state->tport);
1722 	state->tport.ops = &amiga_port_ops;
1723 	tty_port_link_device(&state->tport, serial_driver, 0);
1724 
1725 	error = tty_register_driver(serial_driver);
1726 	if (error)
1727 		goto fail_put_tty_driver;
1728 
1729 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1730 
1731 	/* Hardware set up */
1732 
1733 	state->baud_base = amiga_colorclock;
1734 	state->xmit_fifo_size = 1;
1735 
1736 	/* set ISRs, and then disable the rx interrupts */
1737 	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1738 	if (error)
1739 		goto fail_unregister;
1740 
1741 	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1742 			    "serial RX", state);
1743 	if (error)
1744 		goto fail_free_irq;
1745 
1746 	local_irq_save(flags);
1747 
1748 	/* turn off Rx and Tx interrupts */
1749 	custom.intena = IF_RBF | IF_TBE;
1750 	mb();
1751 
1752 	/* clear any pending interrupt */
1753 	custom.intreq = IF_RBF | IF_TBE;
1754 	mb();
1755 
1756 	local_irq_restore(flags);
1757 
1758 	/*
1759 	 * set the appropriate directions for the modem control flags,
1760 	 * and clear RTS and DTR
1761 	 */
1762 	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1763 	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1764 
1765 	platform_set_drvdata(pdev, state);
1766 
1767 	return 0;
1768 
1769 fail_free_irq:
1770 	free_irq(IRQ_AMIGA_TBE, state);
1771 fail_unregister:
1772 	tty_unregister_driver(serial_driver);
1773 fail_put_tty_driver:
1774 	tty_port_destroy(&state->tport);
1775 	put_tty_driver(serial_driver);
1776 	return error;
1777 }
1778 
1779 static int __exit amiga_serial_remove(struct platform_device *pdev)
1780 {
1781 	int error;
1782 	struct serial_state *state = platform_get_drvdata(pdev);
1783 
1784 	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
1785 	if ((error = tty_unregister_driver(serial_driver)))
1786 		printk("SERIAL: failed to unregister serial driver (%d)\n",
1787 		       error);
1788 	put_tty_driver(serial_driver);
1789 	tty_port_destroy(&state->tport);
1790 
1791 	free_irq(IRQ_AMIGA_TBE, state);
1792 	free_irq(IRQ_AMIGA_RBF, state);
1793 
1794 	platform_set_drvdata(pdev, NULL);
1795 
1796 	return error;
1797 }
1798 
1799 static struct platform_driver amiga_serial_driver = {
1800 	.remove = __exit_p(amiga_serial_remove),
1801 	.driver   = {
1802 		.name	= "amiga-serial",
1803 		.owner	= THIS_MODULE,
1804 	},
1805 };
1806 
1807 static int __init amiga_serial_init(void)
1808 {
1809 	return platform_driver_probe(&amiga_serial_driver, amiga_serial_probe);
1810 }
1811 
1812 module_init(amiga_serial_init);
1813 
1814 static void __exit amiga_serial_exit(void)
1815 {
1816 	platform_driver_unregister(&amiga_serial_driver);
1817 }
1818 
1819 module_exit(amiga_serial_exit);
1820 
1821 
1822 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1823 
1824 /*
1825  * ------------------------------------------------------------
1826  * Serial console driver
1827  * ------------------------------------------------------------
1828  */
1829 
1830 static void amiga_serial_putc(char c)
1831 {
1832 	custom.serdat = (unsigned char)c | 0x100;
1833 	while (!(custom.serdatr & 0x2000))
1834 		barrier();
1835 }
1836 
1837 /*
1838  *	Print a string to the serial port trying not to disturb
1839  *	any possible real use of the port...
1840  *
1841  *	The console must be locked when we get here.
1842  */
1843 static void serial_console_write(struct console *co, const char *s,
1844 				unsigned count)
1845 {
1846 	unsigned short intena = custom.intenar;
1847 
1848 	custom.intena = IF_TBE;
1849 
1850 	while (count--) {
1851 		if (*s == '\n')
1852 			amiga_serial_putc('\r');
1853 		amiga_serial_putc(*s++);
1854 	}
1855 
1856 	custom.intena = IF_SETCLR | (intena & IF_TBE);
1857 }
1858 
1859 static struct tty_driver *serial_console_device(struct console *c, int *index)
1860 {
1861 	*index = 0;
1862 	return serial_driver;
1863 }
1864 
1865 static struct console sercons = {
1866 	.name =		"ttyS",
1867 	.write =	serial_console_write,
1868 	.device =	serial_console_device,
1869 	.flags =	CON_PRINTBUFFER,
1870 	.index =	-1,
1871 };
1872 
1873 /*
1874  *	Register console.
1875  */
1876 static int __init amiserial_console_init(void)
1877 {
1878 	register_console(&sercons);
1879 	return 0;
1880 }
1881 console_initcall(amiserial_console_init);
1882 
1883 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1884 
1885 MODULE_LICENSE("GPL");
1886 MODULE_ALIAS("platform:amiga-serial");
1887