xref: /linux/drivers/tty/amiserial.c (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Serial driver for the amiga builtin port.
4  *
5  * This code was created by taking serial.c version 4.30 from kernel
6  * release 2.3.22, replacing all hardware related stuff with the
7  * corresponding amiga hardware actions, and removing all irrelevant
8  * code. As a consequence, it uses many of the constants and names
9  * associated with the registers and bits of 16550 compatible UARTS -
10  * but only to keep track of status, etc in the state variables. It
11  * was done this was to make it easier to keep the code in line with
12  * (non hardware specific) changes to serial.c.
13  *
14  * The port is registered with the tty driver as minor device 64, and
15  * therefore other ports should should only use 65 upwards.
16  *
17  * Richard Lucock 28/12/99
18  *
19  *  Copyright (C) 1991, 1992  Linus Torvalds
20  *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
21  * 		1998, 1999  Theodore Ts'o
22  *
23  */
24 
25 /* Set of debugging defines */
26 
27 #undef SERIAL_DEBUG_INTR
28 #undef SERIAL_DEBUG_OPEN
29 #undef SERIAL_DEBUG_FLOW
30 #undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
31 
32 /*
33  * End of serial driver configuration section.
34  */
35 
36 #include <linux/bitops.h>
37 #include <linux/circ_buf.h>
38 #include <linux/console.h>
39 #include <linux/delay.h>
40 #include <linux/errno.h>
41 #include <linux/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/interrupt.h>
44 #include <linux/ioport.h>
45 #include <linux/kernel.h>
46 #include <linux/major.h>
47 #include <linux/mm.h>
48 #include <linux/module.h>
49 #include <linux/platform_device.h>
50 #include <linux/ptrace.h>
51 #include <linux/seq_file.h>
52 #include <linux/serial.h>
53 #include <linux/serial_reg.h>
54 #include <linux/sched.h>
55 #include <linux/signal.h>
56 #include <linux/slab.h>
57 #include <linux/string.h>
58 #include <linux/timer.h>
59 #include <linux/tty_flip.h>
60 #include <linux/tty.h>
61 #include <linux/types.h>
62 #include <linux/uaccess.h>
63 
64 #include <asm/amigahw.h>
65 #include <asm/amigaints.h>
66 #include <asm/irq.h>
67 #include <asm/setup.h>
68 
69 struct serial_state {
70 	struct tty_port		tport;
71 	struct circ_buf		xmit;
72 	struct async_icount	icount;
73 
74 	unsigned long		port;
75 	int			baud_base;
76 	int			custom_divisor;
77 	int			read_status_mask;
78 	int			ignore_status_mask;
79 	int			timeout;
80 	int			quot;
81 	int			IER; 	/* Interrupt Enable Register */
82 	int			MCR; 	/* Modem control register */
83 	int			x_char;	/* xon/xoff character */
84 };
85 
86 static struct tty_driver *serial_driver;
87 
88 /* number of characters left in xmit buffer before we ask for more */
89 #define WAKEUP_CHARS 256
90 
91 #define XMIT_FIFO_SIZE 1
92 
93 static unsigned char current_ctl_bits;
94 
95 static void change_speed(struct tty_struct *tty, struct serial_state *info,
96 		struct ktermios *old);
97 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
98 
99 
100 static struct serial_state serial_state;
101 
102 /* some serial hardware definitions */
103 #define SDR_OVRUN   (1<<15)
104 #define SDR_RBF     (1<<14)
105 #define SDR_TBE     (1<<13)
106 #define SDR_TSRE    (1<<12)
107 
108 #define SERPER_PARENB    (1<<15)
109 
110 #define AC_SETCLR   (1<<15)
111 #define AC_UARTBRK  (1<<11)
112 
113 #define SER_DTR     (1<<7)
114 #define SER_RTS     (1<<6)
115 #define SER_DCD     (1<<5)
116 #define SER_CTS     (1<<4)
117 #define SER_DSR     (1<<3)
118 
119 static __inline__ void rtsdtr_ctrl(int bits)
120 {
121     ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
122 }
123 
124 /*
125  * ------------------------------------------------------------
126  * rs_stop() and rs_start()
127  *
128  * This routines are called before setting or resetting tty->flow.stopped.
129  * They enable or disable transmitter interrupts, as necessary.
130  * ------------------------------------------------------------
131  */
132 static void rs_stop(struct tty_struct *tty)
133 {
134 	struct serial_state *info = tty->driver_data;
135 	unsigned long flags;
136 
137 	local_irq_save(flags);
138 	if (info->IER & UART_IER_THRI) {
139 		info->IER &= ~UART_IER_THRI;
140 		/* disable Tx interrupt and remove any pending interrupts */
141 		amiga_custom.intena = IF_TBE;
142 		mb();
143 		amiga_custom.intreq = IF_TBE;
144 		mb();
145 	}
146 	local_irq_restore(flags);
147 }
148 
149 static void rs_start(struct tty_struct *tty)
150 {
151 	struct serial_state *info = tty->driver_data;
152 	unsigned long flags;
153 
154 	local_irq_save(flags);
155 	if (info->xmit.head != info->xmit.tail
156 	    && info->xmit.buf
157 	    && !(info->IER & UART_IER_THRI)) {
158 		info->IER |= UART_IER_THRI;
159 		amiga_custom.intena = IF_SETCLR | IF_TBE;
160 		mb();
161 		/* set a pending Tx Interrupt, transmitter should restart now */
162 		amiga_custom.intreq = IF_SETCLR | IF_TBE;
163 		mb();
164 	}
165 	local_irq_restore(flags);
166 }
167 
168 /*
169  * ----------------------------------------------------------------------
170  *
171  * Here start the interrupt handling routines.
172  *
173  * -----------------------------------------------------------------------
174  */
175 
176 static void receive_chars(struct serial_state *info)
177 {
178         int status;
179 	int serdatr;
180 	unsigned char ch, flag;
181 	struct	async_icount *icount;
182 	int oe = 0;
183 
184 	icount = &info->icount;
185 
186 	status = UART_LSR_DR; /* We obviously have a character! */
187 	serdatr = amiga_custom.serdatr;
188 	mb();
189 	amiga_custom.intreq = IF_RBF;
190 	mb();
191 
192 	if((serdatr & 0x1ff) == 0)
193 	    status |= UART_LSR_BI;
194 	if(serdatr & SDR_OVRUN)
195 	    status |= UART_LSR_OE;
196 
197 	ch = serdatr & 0xff;
198 	icount->rx++;
199 
200 #ifdef SERIAL_DEBUG_INTR
201 	printk("DR%02x:%02x...", ch, status);
202 #endif
203 	flag = TTY_NORMAL;
204 
205 	/*
206 	 * We don't handle parity or frame errors - but I have left
207 	 * the code in, since I'm not sure that the errors can't be
208 	 * detected.
209 	 */
210 
211 	if (status & (UART_LSR_BI | UART_LSR_PE |
212 		      UART_LSR_FE | UART_LSR_OE)) {
213 	  /*
214 	   * For statistics only
215 	   */
216 	  if (status & UART_LSR_BI) {
217 	    status &= ~(UART_LSR_FE | UART_LSR_PE);
218 	    icount->brk++;
219 	  } else if (status & UART_LSR_PE)
220 	    icount->parity++;
221 	  else if (status & UART_LSR_FE)
222 	    icount->frame++;
223 	  if (status & UART_LSR_OE)
224 	    icount->overrun++;
225 
226 	  /*
227 	   * Now check to see if character should be
228 	   * ignored, and mask off conditions which
229 	   * should be ignored.
230 	   */
231 	  if (status & info->ignore_status_mask)
232 	    goto out;
233 
234 	  status &= info->read_status_mask;
235 
236 	  if (status & (UART_LSR_BI)) {
237 #ifdef SERIAL_DEBUG_INTR
238 	    printk("handling break....");
239 #endif
240 	    flag = TTY_BREAK;
241 	    if (info->tport.flags & ASYNC_SAK)
242 	      do_SAK(info->tport.tty);
243 	  } else if (status & UART_LSR_PE)
244 	    flag = TTY_PARITY;
245 	  else if (status & UART_LSR_FE)
246 	    flag = TTY_FRAME;
247 	  if (status & UART_LSR_OE) {
248 	    /*
249 	     * Overrun is special, since it's
250 	     * reported immediately, and doesn't
251 	     * affect the current character
252 	     */
253 	     oe = 1;
254 	  }
255 	}
256 	tty_insert_flip_char(&info->tport, ch, flag);
257 	if (oe == 1)
258 		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
259 	tty_flip_buffer_push(&info->tport);
260 out:
261 	return;
262 }
263 
264 static void transmit_chars(struct serial_state *info)
265 {
266 	amiga_custom.intreq = IF_TBE;
267 	mb();
268 	if (info->x_char) {
269 	        amiga_custom.serdat = info->x_char | 0x100;
270 		mb();
271 		info->icount.tx++;
272 		info->x_char = 0;
273 		return;
274 	}
275 	if (info->xmit.head == info->xmit.tail
276 	    || info->tport.tty->flow.stopped
277 	    || info->tport.tty->hw_stopped) {
278 		info->IER &= ~UART_IER_THRI;
279 	        amiga_custom.intena = IF_TBE;
280 		mb();
281 		return;
282 	}
283 
284 	amiga_custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
285 	mb();
286 	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
287 	info->icount.tx++;
288 
289 	if (CIRC_CNT(info->xmit.head,
290 		     info->xmit.tail,
291 		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
292 		tty_wakeup(info->tport.tty);
293 
294 #ifdef SERIAL_DEBUG_INTR
295 	printk("THRE...");
296 #endif
297 	if (info->xmit.head == info->xmit.tail) {
298 	        amiga_custom.intena = IF_TBE;
299 		mb();
300 		info->IER &= ~UART_IER_THRI;
301 	}
302 }
303 
304 static void check_modem_status(struct serial_state *info)
305 {
306 	struct tty_port *port = &info->tport;
307 	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
308 	unsigned char dstatus;
309 	struct	async_icount *icount;
310 
311 	/* Determine bits that have changed */
312 	dstatus = status ^ current_ctl_bits;
313 	current_ctl_bits = status;
314 
315 	if (dstatus) {
316 		icount = &info->icount;
317 		/* update input line counters */
318 		if (dstatus & SER_DSR)
319 			icount->dsr++;
320 		if (dstatus & SER_DCD) {
321 			icount->dcd++;
322 		}
323 		if (dstatus & SER_CTS)
324 			icount->cts++;
325 		wake_up_interruptible(&port->delta_msr_wait);
326 	}
327 
328 	if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
329 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
330 		printk("ttyS%d CD now %s...", info->line,
331 		       (!(status & SER_DCD)) ? "on" : "off");
332 #endif
333 		if (!(status & SER_DCD))
334 			wake_up_interruptible(&port->open_wait);
335 		else {
336 #ifdef SERIAL_DEBUG_OPEN
337 			printk("doing serial hangup...");
338 #endif
339 			if (port->tty)
340 				tty_hangup(port->tty);
341 		}
342 	}
343 	if (tty_port_cts_enabled(port)) {
344 		if (port->tty->hw_stopped) {
345 			if (!(status & SER_CTS)) {
346 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
347 				printk("CTS tx start...");
348 #endif
349 				port->tty->hw_stopped = 0;
350 				info->IER |= UART_IER_THRI;
351 				amiga_custom.intena = IF_SETCLR | IF_TBE;
352 				mb();
353 				/* set a pending Tx Interrupt, transmitter should restart now */
354 				amiga_custom.intreq = IF_SETCLR | IF_TBE;
355 				mb();
356 				tty_wakeup(port->tty);
357 				return;
358 			}
359 		} else {
360 			if ((status & SER_CTS)) {
361 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
362 				printk("CTS tx stop...");
363 #endif
364 				port->tty->hw_stopped = 1;
365 				info->IER &= ~UART_IER_THRI;
366 				/* disable Tx interrupt and remove any pending interrupts */
367 				amiga_custom.intena = IF_TBE;
368 				mb();
369 				amiga_custom.intreq = IF_TBE;
370 				mb();
371 			}
372 		}
373 	}
374 }
375 
376 static irqreturn_t ser_vbl_int( int irq, void *data)
377 {
378         /* vbl is just a periodic interrupt we tie into to update modem status */
379 	struct serial_state *info = data;
380 	/*
381 	 * TBD - is it better to unregister from this interrupt or to
382 	 * ignore it if MSI is clear ?
383 	 */
384 	if(info->IER & UART_IER_MSI)
385 	  check_modem_status(info);
386 	return IRQ_HANDLED;
387 }
388 
389 static irqreturn_t ser_rx_int(int irq, void *dev_id)
390 {
391 	struct serial_state *info = dev_id;
392 
393 #ifdef SERIAL_DEBUG_INTR
394 	printk("ser_rx_int...");
395 #endif
396 
397 	if (!info->tport.tty)
398 		return IRQ_NONE;
399 
400 	receive_chars(info);
401 #ifdef SERIAL_DEBUG_INTR
402 	printk("end.\n");
403 #endif
404 	return IRQ_HANDLED;
405 }
406 
407 static irqreturn_t ser_tx_int(int irq, void *dev_id)
408 {
409 	struct serial_state *info = dev_id;
410 
411 	if (amiga_custom.serdatr & SDR_TBE) {
412 #ifdef SERIAL_DEBUG_INTR
413 	  printk("ser_tx_int...");
414 #endif
415 
416 	  if (!info->tport.tty)
417 		return IRQ_NONE;
418 
419 	  transmit_chars(info);
420 #ifdef SERIAL_DEBUG_INTR
421 	  printk("end.\n");
422 #endif
423 	}
424 	return IRQ_HANDLED;
425 }
426 
427 /*
428  * -------------------------------------------------------------------
429  * Here ends the serial interrupt routines.
430  * -------------------------------------------------------------------
431  */
432 
433 /*
434  * ---------------------------------------------------------------
435  * Low level utility subroutines for the serial driver:  routines to
436  * figure out the appropriate timeout for an interrupt chain, routines
437  * to initialize and startup a serial port, and routines to shutdown a
438  * serial port.  Useful stuff like that.
439  * ---------------------------------------------------------------
440  */
441 
442 static int startup(struct tty_struct *tty, struct serial_state *info)
443 {
444 	struct tty_port *port = &info->tport;
445 	unsigned long flags;
446 	int	retval=0;
447 	unsigned long page;
448 
449 	page = get_zeroed_page(GFP_KERNEL);
450 	if (!page)
451 		return -ENOMEM;
452 
453 	local_irq_save(flags);
454 
455 	if (tty_port_initialized(port)) {
456 		free_page(page);
457 		goto errout;
458 	}
459 
460 	if (info->xmit.buf)
461 		free_page(page);
462 	else
463 		info->xmit.buf = (unsigned char *) page;
464 
465 #ifdef SERIAL_DEBUG_OPEN
466 	printk("starting up ttys%d ...", info->line);
467 #endif
468 
469 	/* Clear anything in the input buffer */
470 
471 	amiga_custom.intreq = IF_RBF;
472 	mb();
473 
474 	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
475 	if (retval) {
476 		if (capable(CAP_SYS_ADMIN)) {
477 			set_bit(TTY_IO_ERROR, &tty->flags);
478 			retval = 0;
479 		}
480 		goto errout;
481 	}
482 
483 	/* enable both Rx and Tx interrupts */
484 	amiga_custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
485 	mb();
486 	info->IER = UART_IER_MSI;
487 
488 	/* remember current state of the DCD and CTS bits */
489 	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
490 
491 	info->MCR = 0;
492 	if (C_BAUD(tty))
493 	  info->MCR = SER_DTR | SER_RTS;
494 	rtsdtr_ctrl(info->MCR);
495 
496 	clear_bit(TTY_IO_ERROR, &tty->flags);
497 	info->xmit.head = info->xmit.tail = 0;
498 
499 	/*
500 	 * and set the speed of the serial port
501 	 */
502 	change_speed(tty, info, NULL);
503 
504 	tty_port_set_initialized(port, 1);
505 	local_irq_restore(flags);
506 	return 0;
507 
508 errout:
509 	local_irq_restore(flags);
510 	return retval;
511 }
512 
513 /*
514  * This routine will shutdown a serial port; interrupts are disabled, and
515  * DTR is dropped if the hangup on close termio flag is on.
516  */
517 static void shutdown(struct tty_struct *tty, struct serial_state *info)
518 {
519 	unsigned long	flags;
520 
521 	if (!tty_port_initialized(&info->tport))
522 		return;
523 
524 #ifdef SERIAL_DEBUG_OPEN
525 	printk("Shutting down serial port %d ....\n", info->line);
526 #endif
527 
528 	local_irq_save(flags); /* Disable interrupts */
529 
530 	/*
531 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
532 	 * here so the queue might never be waken up
533 	 */
534 	wake_up_interruptible(&info->tport.delta_msr_wait);
535 
536 	/*
537 	 * Free the IRQ, if necessary
538 	 */
539 	free_irq(IRQ_AMIGA_VERTB, info);
540 
541 	free_page((unsigned long)info->xmit.buf);
542 	info->xmit.buf = NULL;
543 
544 	info->IER = 0;
545 	amiga_custom.intena = IF_RBF | IF_TBE;
546 	mb();
547 
548 	/* disable break condition */
549 	amiga_custom.adkcon = AC_UARTBRK;
550 	mb();
551 
552 	if (C_HUPCL(tty))
553 		info->MCR &= ~(SER_DTR|SER_RTS);
554 	rtsdtr_ctrl(info->MCR);
555 
556 	set_bit(TTY_IO_ERROR, &tty->flags);
557 
558 	tty_port_set_initialized(&info->tport, 0);
559 	local_irq_restore(flags);
560 }
561 
562 
563 /*
564  * This routine is called to set the UART divisor registers to match
565  * the specified baud rate for a serial port.
566  */
567 static void change_speed(struct tty_struct *tty, struct serial_state *info,
568 			 struct ktermios *old_termios)
569 {
570 	struct tty_port *port = &info->tport;
571 	int	quot = 0, baud_base, baud;
572 	unsigned cflag, cval = 0;
573 	int	bits;
574 	unsigned long	flags;
575 
576 	cflag = tty->termios.c_cflag;
577 
578 	/* Byte size is always 8 bits plus parity bit if requested */
579 
580 	cval = 3; bits = 10;
581 	if (cflag & CSTOPB) {
582 		cval |= 0x04;
583 		bits++;
584 	}
585 	if (cflag & PARENB) {
586 		cval |= UART_LCR_PARITY;
587 		bits++;
588 	}
589 	if (!(cflag & PARODD))
590 		cval |= UART_LCR_EPAR;
591 #ifdef CMSPAR
592 	if (cflag & CMSPAR)
593 		cval |= UART_LCR_SPAR;
594 #endif
595 
596 	/* Determine divisor based on baud rate */
597 	baud = tty_get_baud_rate(tty);
598 	if (!baud)
599 		baud = 9600;	/* B0 transition handled in rs_set_termios */
600 	baud_base = info->baud_base;
601 	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
602 		quot = info->custom_divisor;
603 	else {
604 		if (baud == 134)
605 			/* Special case since 134 is really 134.5 */
606 			quot = (2*baud_base / 269);
607 		else if (baud)
608 			quot = baud_base / baud;
609 	}
610 	/* If the quotient is zero refuse the change */
611 	if (!quot && old_termios) {
612 		/* FIXME: Will need updating for new tty in the end */
613 		tty->termios.c_cflag &= ~CBAUD;
614 		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
615 		baud = tty_get_baud_rate(tty);
616 		if (!baud)
617 			baud = 9600;
618 		if (baud == 38400 &&
619 		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
620 			quot = info->custom_divisor;
621 		else {
622 			if (baud == 134)
623 				/* Special case since 134 is really 134.5 */
624 				quot = (2*baud_base / 269);
625 			else if (baud)
626 				quot = baud_base / baud;
627 		}
628 	}
629 	/* As a last resort, if the quotient is zero, default to 9600 bps */
630 	if (!quot)
631 		quot = baud_base / 9600;
632 	info->quot = quot;
633 	info->timeout = (XMIT_FIFO_SIZE*HZ*bits*quot) / baud_base;
634 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
635 
636 	/* CTS flow control flag and modem status interrupts */
637 	info->IER &= ~UART_IER_MSI;
638 	if (port->flags & ASYNC_HARDPPS_CD)
639 		info->IER |= UART_IER_MSI;
640 	tty_port_set_cts_flow(port, cflag & CRTSCTS);
641 	if (cflag & CRTSCTS)
642 		info->IER |= UART_IER_MSI;
643 	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
644 	if (~cflag & CLOCAL)
645 		info->IER |= UART_IER_MSI;
646 	/* TBD:
647 	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
648 	 */
649 
650 	/*
651 	 * Set up parity check flag
652 	 */
653 
654 	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
655 	if (I_INPCK(tty))
656 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
657 	if (I_BRKINT(tty) || I_PARMRK(tty))
658 		info->read_status_mask |= UART_LSR_BI;
659 
660 	/*
661 	 * Characters to ignore
662 	 */
663 	info->ignore_status_mask = 0;
664 	if (I_IGNPAR(tty))
665 		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
666 	if (I_IGNBRK(tty)) {
667 		info->ignore_status_mask |= UART_LSR_BI;
668 		/*
669 		 * If we're ignore parity and break indicators, ignore
670 		 * overruns too.  (For real raw support).
671 		 */
672 		if (I_IGNPAR(tty))
673 			info->ignore_status_mask |= UART_LSR_OE;
674 	}
675 	/*
676 	 * !!! ignore all characters if CREAD is not set
677 	 */
678 	if ((cflag & CREAD) == 0)
679 		info->ignore_status_mask |= UART_LSR_DR;
680 	local_irq_save(flags);
681 
682 	{
683 	  short serper;
684 
685 	/* Set up the baud rate */
686 	  serper = quot - 1;
687 
688 	/* Enable or disable parity bit */
689 
690 	if(cval & UART_LCR_PARITY)
691 	  serper |= (SERPER_PARENB);
692 
693 	amiga_custom.serper = serper;
694 	mb();
695 	}
696 
697 	local_irq_restore(flags);
698 }
699 
700 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
701 {
702 	struct serial_state *info;
703 	unsigned long flags;
704 
705 	info = tty->driver_data;
706 
707 	if (!info->xmit.buf)
708 		return 0;
709 
710 	local_irq_save(flags);
711 	if (CIRC_SPACE(info->xmit.head,
712 		       info->xmit.tail,
713 		       SERIAL_XMIT_SIZE) == 0) {
714 		local_irq_restore(flags);
715 		return 0;
716 	}
717 
718 	info->xmit.buf[info->xmit.head++] = ch;
719 	info->xmit.head &= SERIAL_XMIT_SIZE-1;
720 	local_irq_restore(flags);
721 	return 1;
722 }
723 
724 static void rs_flush_chars(struct tty_struct *tty)
725 {
726 	struct serial_state *info = tty->driver_data;
727 	unsigned long flags;
728 
729 	if (info->xmit.head == info->xmit.tail
730 	    || tty->flow.stopped
731 	    || tty->hw_stopped
732 	    || !info->xmit.buf)
733 		return;
734 
735 	local_irq_save(flags);
736 	info->IER |= UART_IER_THRI;
737 	amiga_custom.intena = IF_SETCLR | IF_TBE;
738 	mb();
739 	/* set a pending Tx Interrupt, transmitter should restart now */
740 	amiga_custom.intreq = IF_SETCLR | IF_TBE;
741 	mb();
742 	local_irq_restore(flags);
743 }
744 
745 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
746 {
747 	int	c, ret = 0;
748 	struct serial_state *info = tty->driver_data;
749 	unsigned long flags;
750 
751 	if (!info->xmit.buf)
752 		return 0;
753 
754 	local_irq_save(flags);
755 	while (1) {
756 		c = CIRC_SPACE_TO_END(info->xmit.head,
757 				      info->xmit.tail,
758 				      SERIAL_XMIT_SIZE);
759 		if (count < c)
760 			c = count;
761 		if (c <= 0) {
762 			break;
763 		}
764 		memcpy(info->xmit.buf + info->xmit.head, buf, c);
765 		info->xmit.head = ((info->xmit.head + c) &
766 				   (SERIAL_XMIT_SIZE-1));
767 		buf += c;
768 		count -= c;
769 		ret += c;
770 	}
771 	local_irq_restore(flags);
772 
773 	if (info->xmit.head != info->xmit.tail
774 	    && !tty->flow.stopped
775 	    && !tty->hw_stopped
776 	    && !(info->IER & UART_IER_THRI)) {
777 		info->IER |= UART_IER_THRI;
778 		local_irq_disable();
779 		amiga_custom.intena = IF_SETCLR | IF_TBE;
780 		mb();
781 		/* set a pending Tx Interrupt, transmitter should restart now */
782 		amiga_custom.intreq = IF_SETCLR | IF_TBE;
783 		mb();
784 		local_irq_restore(flags);
785 	}
786 	return ret;
787 }
788 
789 static unsigned int rs_write_room(struct tty_struct *tty)
790 {
791 	struct serial_state *info = tty->driver_data;
792 
793 	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
794 }
795 
796 static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
797 {
798 	struct serial_state *info = tty->driver_data;
799 
800 	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
801 }
802 
803 static void rs_flush_buffer(struct tty_struct *tty)
804 {
805 	struct serial_state *info = tty->driver_data;
806 	unsigned long flags;
807 
808 	local_irq_save(flags);
809 	info->xmit.head = info->xmit.tail = 0;
810 	local_irq_restore(flags);
811 	tty_wakeup(tty);
812 }
813 
814 /*
815  * This function is used to send a high-priority XON/XOFF character to
816  * the device
817  */
818 static void rs_send_xchar(struct tty_struct *tty, char ch)
819 {
820 	struct serial_state *info = tty->driver_data;
821         unsigned long flags;
822 
823 	info->x_char = ch;
824 	if (ch) {
825 		/* Make sure transmit interrupts are on */
826 
827 	        /* Check this ! */
828 	        local_irq_save(flags);
829 		if(!(amiga_custom.intenar & IF_TBE)) {
830 		    amiga_custom.intena = IF_SETCLR | IF_TBE;
831 		    mb();
832 		    /* set a pending Tx Interrupt, transmitter should restart now */
833 		    amiga_custom.intreq = IF_SETCLR | IF_TBE;
834 		    mb();
835 		}
836 		local_irq_restore(flags);
837 
838 		info->IER |= UART_IER_THRI;
839 	}
840 }
841 
842 /*
843  * ------------------------------------------------------------
844  * rs_throttle()
845  *
846  * This routine is called by the upper-layer tty layer to signal that
847  * incoming characters should be throttled.
848  * ------------------------------------------------------------
849  */
850 static void rs_throttle(struct tty_struct * tty)
851 {
852 	struct serial_state *info = tty->driver_data;
853 	unsigned long flags;
854 #ifdef SERIAL_DEBUG_THROTTLE
855 	printk("throttle %s ....\n", tty_name(tty));
856 #endif
857 
858 	if (I_IXOFF(tty))
859 		rs_send_xchar(tty, STOP_CHAR(tty));
860 
861 	if (C_CRTSCTS(tty))
862 		info->MCR &= ~SER_RTS;
863 
864 	local_irq_save(flags);
865 	rtsdtr_ctrl(info->MCR);
866 	local_irq_restore(flags);
867 }
868 
869 static void rs_unthrottle(struct tty_struct * tty)
870 {
871 	struct serial_state *info = tty->driver_data;
872 	unsigned long flags;
873 #ifdef SERIAL_DEBUG_THROTTLE
874 	printk("unthrottle %s ....\n", tty_name(tty));
875 #endif
876 
877 	if (I_IXOFF(tty)) {
878 		if (info->x_char)
879 			info->x_char = 0;
880 		else
881 			rs_send_xchar(tty, START_CHAR(tty));
882 	}
883 	if (C_CRTSCTS(tty))
884 		info->MCR |= SER_RTS;
885 	local_irq_save(flags);
886 	rtsdtr_ctrl(info->MCR);
887 	local_irq_restore(flags);
888 }
889 
890 /*
891  * ------------------------------------------------------------
892  * rs_ioctl() and friends
893  * ------------------------------------------------------------
894  */
895 
896 static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
897 {
898 	struct serial_state *state = tty->driver_data;
899 	unsigned int close_delay, closing_wait;
900 
901 	tty_lock(tty);
902 	close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
903 	closing_wait = state->tport.closing_wait;
904 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
905 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
906 
907 	ss->line = tty->index;
908 	ss->port = state->port;
909 	ss->flags = state->tport.flags;
910 	ss->xmit_fifo_size = XMIT_FIFO_SIZE;
911 	ss->baud_base = state->baud_base;
912 	ss->close_delay = close_delay;
913 	ss->closing_wait = closing_wait;
914 	ss->custom_divisor = state->custom_divisor;
915 	tty_unlock(tty);
916 	return 0;
917 }
918 
919 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
920 {
921 	struct serial_state *state = tty->driver_data;
922 	struct tty_port *port = &state->tport;
923 	bool change_spd;
924 	int 			retval = 0;
925 	unsigned int close_delay, closing_wait;
926 
927 	tty_lock(tty);
928 	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
929 		ss->custom_divisor != state->custom_divisor;
930 	if (ss->irq || ss->port != state->port ||
931 			ss->xmit_fifo_size != XMIT_FIFO_SIZE) {
932 		tty_unlock(tty);
933 		return -EINVAL;
934 	}
935 
936 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
937 	closing_wait = ss->closing_wait;
938 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
939 		closing_wait = msecs_to_jiffies(closing_wait * 10);
940 
941 	if (!capable(CAP_SYS_ADMIN)) {
942 		if ((ss->baud_base != state->baud_base) ||
943 		    (close_delay != port->close_delay) ||
944 		    (closing_wait != port->closing_wait) ||
945 		    ((ss->flags & ~ASYNC_USR_MASK) !=
946 		     (port->flags & ~ASYNC_USR_MASK))) {
947 			tty_unlock(tty);
948 			return -EPERM;
949 		}
950 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
951 			       (ss->flags & ASYNC_USR_MASK));
952 		state->custom_divisor = ss->custom_divisor;
953 		goto check_and_exit;
954 	}
955 
956 	if (ss->baud_base < 9600) {
957 		tty_unlock(tty);
958 		return -EINVAL;
959 	}
960 
961 	/*
962 	 * OK, past this point, all the error checking has been done.
963 	 * At this point, we start making changes.....
964 	 */
965 
966 	state->baud_base = ss->baud_base;
967 	port->flags = ((port->flags & ~ASYNC_FLAGS) |
968 			(ss->flags & ASYNC_FLAGS));
969 	state->custom_divisor = ss->custom_divisor;
970 	port->close_delay = close_delay;
971 	port->closing_wait = closing_wait;
972 
973 check_and_exit:
974 	if (tty_port_initialized(port)) {
975 		if (change_spd) {
976 			/* warn about deprecation unless clearing */
977 			if (ss->flags & ASYNC_SPD_MASK)
978 				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
979 			change_speed(tty, state, NULL);
980 		}
981 	} else
982 		retval = startup(tty, state);
983 	tty_unlock(tty);
984 	return retval;
985 }
986 
987 /*
988  * get_lsr_info - get line status register info
989  *
990  * Purpose: Let user call ioctl() to get info when the UART physically
991  * 	    is emptied.  On bus types like RS485, the transmitter must
992  * 	    release the bus after transmitting. This must be done when
993  * 	    the transmit shift register is empty, not be done when the
994  * 	    transmit holding register is empty.  This functionality
995  * 	    allows an RS485 driver to be written in user space.
996  */
997 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
998 {
999 	unsigned char status;
1000 	unsigned int result;
1001 	unsigned long flags;
1002 
1003 	local_irq_save(flags);
1004 	status = amiga_custom.serdatr;
1005 	mb();
1006 	local_irq_restore(flags);
1007 	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1008 	if (copy_to_user(value, &result, sizeof(int)))
1009 		return -EFAULT;
1010 	return 0;
1011 }
1012 
1013 
1014 static int rs_tiocmget(struct tty_struct *tty)
1015 {
1016 	struct serial_state *info = tty->driver_data;
1017 	unsigned char control, status;
1018 	unsigned long flags;
1019 
1020 	if (tty_io_error(tty))
1021 		return -EIO;
1022 
1023 	control = info->MCR;
1024 	local_irq_save(flags);
1025 	status = ciab.pra;
1026 	local_irq_restore(flags);
1027 	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1028 		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1029 		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1030 		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1031 		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1032 }
1033 
1034 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1035 						unsigned int clear)
1036 {
1037 	struct serial_state *info = tty->driver_data;
1038 	unsigned long flags;
1039 
1040 	if (tty_io_error(tty))
1041 		return -EIO;
1042 
1043 	local_irq_save(flags);
1044 	if (set & TIOCM_RTS)
1045 		info->MCR |= SER_RTS;
1046 	if (set & TIOCM_DTR)
1047 		info->MCR |= SER_DTR;
1048 	if (clear & TIOCM_RTS)
1049 		info->MCR &= ~SER_RTS;
1050 	if (clear & TIOCM_DTR)
1051 		info->MCR &= ~SER_DTR;
1052 	rtsdtr_ctrl(info->MCR);
1053 	local_irq_restore(flags);
1054 	return 0;
1055 }
1056 
1057 /*
1058  * rs_break() --- routine which turns the break handling on or off
1059  */
1060 static int rs_break(struct tty_struct *tty, int break_state)
1061 {
1062 	unsigned long flags;
1063 
1064 	local_irq_save(flags);
1065 	if (break_state == -1)
1066 	  amiga_custom.adkcon = AC_SETCLR | AC_UARTBRK;
1067 	else
1068 	  amiga_custom.adkcon = AC_UARTBRK;
1069 	mb();
1070 	local_irq_restore(flags);
1071 	return 0;
1072 }
1073 
1074 /*
1075  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1076  * Return: write counters to the user passed counter struct
1077  * NB: both 1->0 and 0->1 transitions are counted except for
1078  *     RI where only 0->1 is counted.
1079  */
1080 static int rs_get_icount(struct tty_struct *tty,
1081 				struct serial_icounter_struct *icount)
1082 {
1083 	struct serial_state *info = tty->driver_data;
1084 	struct async_icount cnow;
1085 	unsigned long flags;
1086 
1087 	local_irq_save(flags);
1088 	cnow = info->icount;
1089 	local_irq_restore(flags);
1090 	icount->cts = cnow.cts;
1091 	icount->dsr = cnow.dsr;
1092 	icount->rng = cnow.rng;
1093 	icount->dcd = cnow.dcd;
1094 	icount->rx = cnow.rx;
1095 	icount->tx = cnow.tx;
1096 	icount->frame = cnow.frame;
1097 	icount->overrun = cnow.overrun;
1098 	icount->parity = cnow.parity;
1099 	icount->brk = cnow.brk;
1100 	icount->buf_overrun = cnow.buf_overrun;
1101 
1102 	return 0;
1103 }
1104 
1105 static int rs_ioctl(struct tty_struct *tty,
1106 		    unsigned int cmd, unsigned long arg)
1107 {
1108 	struct serial_state *info = tty->driver_data;
1109 	struct async_icount cprev, cnow;	/* kernel counter temps */
1110 	void __user *argp = (void __user *)arg;
1111 	unsigned long flags;
1112 	DEFINE_WAIT(wait);
1113 	int ret;
1114 
1115 	if ((cmd != TIOCSERCONFIG) &&
1116 	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1117 		if (tty_io_error(tty))
1118 		    return -EIO;
1119 	}
1120 
1121 	switch (cmd) {
1122 		case TIOCSERCONFIG:
1123 			return 0;
1124 
1125 		case TIOCSERGETLSR: /* Get line status register */
1126 			return get_lsr_info(info, argp);
1127 
1128 		/*
1129 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1130 		 * - mask passed in arg for lines of interest
1131  		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1132 		 * Caller should use TIOCGICOUNT to see which one it was
1133 		 */
1134 		case TIOCMIWAIT:
1135 			local_irq_save(flags);
1136 			/* note the counters on entry */
1137 			cprev = info->icount;
1138 			local_irq_restore(flags);
1139 			while (1) {
1140 				prepare_to_wait(&info->tport.delta_msr_wait,
1141 						&wait, TASK_INTERRUPTIBLE);
1142 				local_irq_save(flags);
1143 				cnow = info->icount; /* atomic copy */
1144 				local_irq_restore(flags);
1145 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1146 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
1147 					ret = -EIO; /* no change => error */
1148 					break;
1149 				}
1150 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1151 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1152 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1153 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1154 					ret = 0;
1155 					break;
1156 				}
1157 				schedule();
1158 				/* see if a signal did it */
1159 				if (signal_pending(current)) {
1160 					ret = -ERESTARTSYS;
1161 					break;
1162 				}
1163 				cprev = cnow;
1164 			}
1165 			finish_wait(&info->tport.delta_msr_wait, &wait);
1166 			return ret;
1167 
1168 		default:
1169 			return -ENOIOCTLCMD;
1170 		}
1171 	return 0;
1172 }
1173 
1174 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1175 {
1176 	struct serial_state *info = tty->driver_data;
1177 	unsigned long flags;
1178 	unsigned int cflag = tty->termios.c_cflag;
1179 
1180 	change_speed(tty, info, old_termios);
1181 
1182 	/* Handle transition to B0 status */
1183 	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
1184 		info->MCR &= ~(SER_DTR|SER_RTS);
1185 		local_irq_save(flags);
1186 		rtsdtr_ctrl(info->MCR);
1187 		local_irq_restore(flags);
1188 	}
1189 
1190 	/* Handle transition away from B0 status */
1191 	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1192 		info->MCR |= SER_DTR;
1193 		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
1194 			info->MCR |= SER_RTS;
1195 		local_irq_save(flags);
1196 		rtsdtr_ctrl(info->MCR);
1197 		local_irq_restore(flags);
1198 	}
1199 
1200 	/* Handle turning off CRTSCTS */
1201 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1202 		tty->hw_stopped = 0;
1203 		rs_start(tty);
1204 	}
1205 
1206 #if 0
1207 	/*
1208 	 * No need to wake up processes in open wait, since they
1209 	 * sample the CLOCAL flag once, and don't recheck it.
1210 	 * XXX  It's not clear whether the current behavior is correct
1211 	 * or not.  Hence, this may change.....
1212 	 */
1213 	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
1214 		wake_up_interruptible(&info->open_wait);
1215 #endif
1216 }
1217 
1218 /*
1219  * ------------------------------------------------------------
1220  * rs_close()
1221  *
1222  * This routine is called when the serial port gets closed.  First, we
1223  * wait for the last remaining data to be sent.  Then, we unlink its
1224  * async structure from the interrupt chain if necessary, and we free
1225  * that IRQ if nothing is left in the chain.
1226  * ------------------------------------------------------------
1227  */
1228 static void rs_close(struct tty_struct *tty, struct file * filp)
1229 {
1230 	struct serial_state *state = tty->driver_data;
1231 	struct tty_port *port = &state->tport;
1232 
1233 	if (tty_port_close_start(port, tty, filp) == 0)
1234 		return;
1235 
1236 	/*
1237 	 * At this point we stop accepting input.  To do this, we
1238 	 * disable the receive line status interrupts, and tell the
1239 	 * interrupt driver to stop checking the data ready bit in the
1240 	 * line status register.
1241 	 */
1242 	state->read_status_mask &= ~UART_LSR_DR;
1243 	if (tty_port_initialized(port)) {
1244 	        /* disable receive interrupts */
1245 	        amiga_custom.intena = IF_RBF;
1246 		mb();
1247 		/* clear any pending receive interrupt */
1248 		amiga_custom.intreq = IF_RBF;
1249 		mb();
1250 
1251 		/*
1252 		 * Before we drop DTR, make sure the UART transmitter
1253 		 * has completely drained; this is especially
1254 		 * important if there is a transmit FIFO!
1255 		 */
1256 		rs_wait_until_sent(tty, state->timeout);
1257 	}
1258 	shutdown(tty, state);
1259 	rs_flush_buffer(tty);
1260 
1261 	tty_ldisc_flush(tty);
1262 	port->tty = NULL;
1263 
1264 	tty_port_close_end(port, tty);
1265 }
1266 
1267 /*
1268  * rs_wait_until_sent() --- wait until the transmitter is empty
1269  */
1270 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1271 {
1272 	struct serial_state *info = tty->driver_data;
1273 	unsigned long orig_jiffies, char_time;
1274 	int lsr;
1275 
1276 	orig_jiffies = jiffies;
1277 
1278 	/*
1279 	 * Set the check interval to be 1/5 of the estimated time to
1280 	 * send a single character, and make it at least 1.  The check
1281 	 * interval should also be less than the timeout.
1282 	 *
1283 	 * Note: we have to use pretty tight timings here to satisfy
1284 	 * the NIST-PCTS.
1285 	 */
1286 	char_time = (info->timeout - HZ/50) / XMIT_FIFO_SIZE;
1287 	char_time = char_time / 5;
1288 	if (char_time == 0)
1289 		char_time = 1;
1290 	if (timeout)
1291 	  char_time = min_t(unsigned long, char_time, timeout);
1292 	/*
1293 	 * If the transmitter hasn't cleared in twice the approximate
1294 	 * amount of time to send the entire FIFO, it probably won't
1295 	 * ever clear.  This assumes the UART isn't doing flow
1296 	 * control, which is currently the case.  Hence, if it ever
1297 	 * takes longer than info->timeout, this is probably due to a
1298 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1299 	 * 2*info->timeout.
1300 	 */
1301 	if (!timeout || timeout > 2*info->timeout)
1302 		timeout = 2*info->timeout;
1303 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1304 	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1305 	printk("jiff=%lu...", jiffies);
1306 #endif
1307 	while(!((lsr = amiga_custom.serdatr) & SDR_TSRE)) {
1308 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1309 		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1310 #endif
1311 		msleep_interruptible(jiffies_to_msecs(char_time));
1312 		if (signal_pending(current))
1313 			break;
1314 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1315 			break;
1316 	}
1317 	__set_current_state(TASK_RUNNING);
1318 
1319 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1320 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1321 #endif
1322 }
1323 
1324 /*
1325  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1326  */
1327 static void rs_hangup(struct tty_struct *tty)
1328 {
1329 	struct serial_state *info = tty->driver_data;
1330 
1331 	rs_flush_buffer(tty);
1332 	shutdown(tty, info);
1333 	info->tport.count = 0;
1334 	tty_port_set_active(&info->tport, 0);
1335 	info->tport.tty = NULL;
1336 	wake_up_interruptible(&info->tport.open_wait);
1337 }
1338 
1339 /*
1340  * This routine is called whenever a serial port is opened.  It
1341  * enables interrupts for a serial port, linking in its async structure into
1342  * the IRQ chain.   It also performs the serial-specific
1343  * initialization for the tty structure.
1344  */
1345 static int rs_open(struct tty_struct *tty, struct file * filp)
1346 {
1347 	struct tty_port *port = tty->port;
1348 	struct serial_state *info = container_of(port, struct serial_state,
1349 			tport);
1350 	int retval;
1351 
1352 	port->count++;
1353 	port->tty = tty;
1354 	tty->driver_data = info;
1355 
1356 	retval = startup(tty, info);
1357 	if (retval) {
1358 		return retval;
1359 	}
1360 
1361 	return tty_port_block_til_ready(port, tty, filp);
1362 }
1363 
1364 /*
1365  * /proc fs routines....
1366  */
1367 
1368 static inline void line_info(struct seq_file *m, int line,
1369 		struct serial_state *state)
1370 {
1371 	char	stat_buf[30], control, status;
1372 	unsigned long flags;
1373 
1374 	seq_printf(m, "%d: uart:amiga_builtin", line);
1375 
1376 	local_irq_save(flags);
1377 	status = ciab.pra;
1378 	control = tty_port_initialized(&state->tport) ? state->MCR : status;
1379 	local_irq_restore(flags);
1380 
1381 	stat_buf[0] = 0;
1382 	stat_buf[1] = 0;
1383 	if(!(control & SER_RTS))
1384 		strcat(stat_buf, "|RTS");
1385 	if(!(status & SER_CTS))
1386 		strcat(stat_buf, "|CTS");
1387 	if(!(control & SER_DTR))
1388 		strcat(stat_buf, "|DTR");
1389 	if(!(status & SER_DSR))
1390 		strcat(stat_buf, "|DSR");
1391 	if(!(status & SER_DCD))
1392 		strcat(stat_buf, "|CD");
1393 
1394 	if (state->quot)
1395 		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1396 
1397 	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1398 
1399 	if (state->icount.frame)
1400 		seq_printf(m, " fe:%d", state->icount.frame);
1401 
1402 	if (state->icount.parity)
1403 		seq_printf(m, " pe:%d", state->icount.parity);
1404 
1405 	if (state->icount.brk)
1406 		seq_printf(m, " brk:%d", state->icount.brk);
1407 
1408 	if (state->icount.overrun)
1409 		seq_printf(m, " oe:%d", state->icount.overrun);
1410 
1411 	/*
1412 	 * Last thing is the RS-232 status lines
1413 	 */
1414 	seq_printf(m, " %s\n", stat_buf+1);
1415 }
1416 
1417 static int rs_proc_show(struct seq_file *m, void *v)
1418 {
1419 	seq_printf(m, "serinfo:1.0 driver:4.30\n");
1420 	line_info(m, 0, &serial_state);
1421 	return 0;
1422 }
1423 
1424 /*
1425  * ---------------------------------------------------------------------
1426  * rs_init() and friends
1427  *
1428  * rs_init() is called at boot-time to initialize the serial driver.
1429  * ---------------------------------------------------------------------
1430  */
1431 
1432 static const struct tty_operations serial_ops = {
1433 	.open = rs_open,
1434 	.close = rs_close,
1435 	.write = rs_write,
1436 	.put_char = rs_put_char,
1437 	.flush_chars = rs_flush_chars,
1438 	.write_room = rs_write_room,
1439 	.chars_in_buffer = rs_chars_in_buffer,
1440 	.flush_buffer = rs_flush_buffer,
1441 	.ioctl = rs_ioctl,
1442 	.throttle = rs_throttle,
1443 	.unthrottle = rs_unthrottle,
1444 	.set_termios = rs_set_termios,
1445 	.stop = rs_stop,
1446 	.start = rs_start,
1447 	.hangup = rs_hangup,
1448 	.break_ctl = rs_break,
1449 	.send_xchar = rs_send_xchar,
1450 	.wait_until_sent = rs_wait_until_sent,
1451 	.tiocmget = rs_tiocmget,
1452 	.tiocmset = rs_tiocmset,
1453 	.get_icount = rs_get_icount,
1454 	.set_serial = set_serial_info,
1455 	.get_serial = get_serial_info,
1456 	.proc_show = rs_proc_show,
1457 };
1458 
1459 static int amiga_carrier_raised(struct tty_port *port)
1460 {
1461 	return !(ciab.pra & SER_DCD);
1462 }
1463 
1464 static void amiga_dtr_rts(struct tty_port *port, int raise)
1465 {
1466 	struct serial_state *info = container_of(port, struct serial_state,
1467 			tport);
1468 	unsigned long flags;
1469 
1470 	if (raise)
1471 		info->MCR |= SER_DTR|SER_RTS;
1472 	else
1473 		info->MCR &= ~(SER_DTR|SER_RTS);
1474 
1475 	local_irq_save(flags);
1476 	rtsdtr_ctrl(info->MCR);
1477 	local_irq_restore(flags);
1478 }
1479 
1480 static const struct tty_port_operations amiga_port_ops = {
1481 	.carrier_raised = amiga_carrier_raised,
1482 	.dtr_rts = amiga_dtr_rts,
1483 };
1484 
1485 /*
1486  * The serial driver boot-time initialization code!
1487  */
1488 static int __init amiga_serial_probe(struct platform_device *pdev)
1489 {
1490 	struct serial_state *state = &serial_state;
1491 	struct tty_driver *driver;
1492 	unsigned long flags;
1493 	int error;
1494 
1495 	driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
1496 	if (IS_ERR(driver))
1497 		return PTR_ERR(driver);
1498 
1499 	/* Initialize the tty_driver structure */
1500 
1501 	driver->driver_name = "amiserial";
1502 	driver->name = "ttyS";
1503 	driver->major = TTY_MAJOR;
1504 	driver->minor_start = 64;
1505 	driver->type = TTY_DRIVER_TYPE_SERIAL;
1506 	driver->subtype = SERIAL_TYPE_NORMAL;
1507 	driver->init_termios = tty_std_termios;
1508 	driver->init_termios.c_cflag =
1509 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1510 	tty_set_operations(driver, &serial_ops);
1511 
1512 	memset(state, 0, sizeof(*state));
1513 	state->port = (int)&amiga_custom.serdatr; /* Just to give it a value */
1514 	tty_port_init(&state->tport);
1515 	state->tport.ops = &amiga_port_ops;
1516 	tty_port_link_device(&state->tport, driver, 0);
1517 
1518 	error = tty_register_driver(driver);
1519 	if (error)
1520 		goto fail_tty_driver_kref_put;
1521 
1522 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1523 
1524 	/* Hardware set up */
1525 
1526 	state->baud_base = amiga_colorclock;
1527 
1528 	/* set ISRs, and then disable the rx interrupts */
1529 	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1530 	if (error)
1531 		goto fail_unregister;
1532 
1533 	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1534 			    "serial RX", state);
1535 	if (error)
1536 		goto fail_free_irq;
1537 
1538 	local_irq_save(flags);
1539 
1540 	/* turn off Rx and Tx interrupts */
1541 	amiga_custom.intena = IF_RBF | IF_TBE;
1542 	mb();
1543 
1544 	/* clear any pending interrupt */
1545 	amiga_custom.intreq = IF_RBF | IF_TBE;
1546 	mb();
1547 
1548 	local_irq_restore(flags);
1549 
1550 	/*
1551 	 * set the appropriate directions for the modem control flags,
1552 	 * and clear RTS and DTR
1553 	 */
1554 	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1555 	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1556 
1557 	platform_set_drvdata(pdev, state);
1558 
1559 	serial_driver = driver;
1560 
1561 	return 0;
1562 
1563 fail_free_irq:
1564 	free_irq(IRQ_AMIGA_TBE, state);
1565 fail_unregister:
1566 	tty_unregister_driver(driver);
1567 fail_tty_driver_kref_put:
1568 	tty_port_destroy(&state->tport);
1569 	tty_driver_kref_put(driver);
1570 	return error;
1571 }
1572 
1573 static int __exit amiga_serial_remove(struct platform_device *pdev)
1574 {
1575 	struct serial_state *state = platform_get_drvdata(pdev);
1576 
1577 	tty_unregister_driver(serial_driver);
1578 	tty_driver_kref_put(serial_driver);
1579 	tty_port_destroy(&state->tport);
1580 
1581 	free_irq(IRQ_AMIGA_TBE, state);
1582 	free_irq(IRQ_AMIGA_RBF, state);
1583 
1584 	return 0;
1585 }
1586 
1587 static struct platform_driver amiga_serial_driver = {
1588 	.remove = __exit_p(amiga_serial_remove),
1589 	.driver   = {
1590 		.name	= "amiga-serial",
1591 	},
1592 };
1593 
1594 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1595 
1596 
1597 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1598 
1599 /*
1600  * ------------------------------------------------------------
1601  * Serial console driver
1602  * ------------------------------------------------------------
1603  */
1604 
1605 static void amiga_serial_putc(char c)
1606 {
1607 	amiga_custom.serdat = (unsigned char)c | 0x100;
1608 	while (!(amiga_custom.serdatr & 0x2000))
1609 		barrier();
1610 }
1611 
1612 /*
1613  *	Print a string to the serial port trying not to disturb
1614  *	any possible real use of the port...
1615  *
1616  *	The console must be locked when we get here.
1617  */
1618 static void serial_console_write(struct console *co, const char *s,
1619 				unsigned count)
1620 {
1621 	unsigned short intena = amiga_custom.intenar;
1622 
1623 	amiga_custom.intena = IF_TBE;
1624 
1625 	while (count--) {
1626 		if (*s == '\n')
1627 			amiga_serial_putc('\r');
1628 		amiga_serial_putc(*s++);
1629 	}
1630 
1631 	amiga_custom.intena = IF_SETCLR | (intena & IF_TBE);
1632 }
1633 
1634 static struct tty_driver *serial_console_device(struct console *c, int *index)
1635 {
1636 	*index = 0;
1637 	return serial_driver;
1638 }
1639 
1640 static struct console sercons = {
1641 	.name =		"ttyS",
1642 	.write =	serial_console_write,
1643 	.device =	serial_console_device,
1644 	.flags =	CON_PRINTBUFFER,
1645 	.index =	-1,
1646 };
1647 
1648 /*
1649  *	Register console.
1650  */
1651 static int __init amiserial_console_init(void)
1652 {
1653 	if (!MACH_IS_AMIGA)
1654 		return -ENODEV;
1655 
1656 	register_console(&sercons);
1657 	return 0;
1658 }
1659 console_initcall(amiserial_console_init);
1660 
1661 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1662 
1663 MODULE_LICENSE("GPL");
1664 MODULE_ALIAS("platform:amiga-serial");
1665