xref: /openbmc/linux/drivers/tty/amiserial.c (revision 2cf1c348)
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 	if (info->xmit.buf) {
542 		free_page((unsigned long) info->xmit.buf);
543 		info->xmit.buf = NULL;
544 	}
545 
546 	info->IER = 0;
547 	amiga_custom.intena = IF_RBF | IF_TBE;
548 	mb();
549 
550 	/* disable break condition */
551 	amiga_custom.adkcon = AC_UARTBRK;
552 	mb();
553 
554 	if (C_HUPCL(tty))
555 		info->MCR &= ~(SER_DTR|SER_RTS);
556 	rtsdtr_ctrl(info->MCR);
557 
558 	set_bit(TTY_IO_ERROR, &tty->flags);
559 
560 	tty_port_set_initialized(&info->tport, 0);
561 	local_irq_restore(flags);
562 }
563 
564 
565 /*
566  * This routine is called to set the UART divisor registers to match
567  * the specified baud rate for a serial port.
568  */
569 static void change_speed(struct tty_struct *tty, struct serial_state *info,
570 			 struct ktermios *old_termios)
571 {
572 	struct tty_port *port = &info->tport;
573 	int	quot = 0, baud_base, baud;
574 	unsigned cflag, cval = 0;
575 	int	bits;
576 	unsigned long	flags;
577 
578 	cflag = tty->termios.c_cflag;
579 
580 	/* Byte size is always 8 bits plus parity bit if requested */
581 
582 	cval = 3; bits = 10;
583 	if (cflag & CSTOPB) {
584 		cval |= 0x04;
585 		bits++;
586 	}
587 	if (cflag & PARENB) {
588 		cval |= UART_LCR_PARITY;
589 		bits++;
590 	}
591 	if (!(cflag & PARODD))
592 		cval |= UART_LCR_EPAR;
593 #ifdef CMSPAR
594 	if (cflag & CMSPAR)
595 		cval |= UART_LCR_SPAR;
596 #endif
597 
598 	/* Determine divisor based on baud rate */
599 	baud = tty_get_baud_rate(tty);
600 	if (!baud)
601 		baud = 9600;	/* B0 transition handled in rs_set_termios */
602 	baud_base = info->baud_base;
603 	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
604 		quot = info->custom_divisor;
605 	else {
606 		if (baud == 134)
607 			/* Special case since 134 is really 134.5 */
608 			quot = (2*baud_base / 269);
609 		else if (baud)
610 			quot = baud_base / baud;
611 	}
612 	/* If the quotient is zero refuse the change */
613 	if (!quot && old_termios) {
614 		/* FIXME: Will need updating for new tty in the end */
615 		tty->termios.c_cflag &= ~CBAUD;
616 		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
617 		baud = tty_get_baud_rate(tty);
618 		if (!baud)
619 			baud = 9600;
620 		if (baud == 38400 &&
621 		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
622 			quot = info->custom_divisor;
623 		else {
624 			if (baud == 134)
625 				/* Special case since 134 is really 134.5 */
626 				quot = (2*baud_base / 269);
627 			else if (baud)
628 				quot = baud_base / baud;
629 		}
630 	}
631 	/* As a last resort, if the quotient is zero, default to 9600 bps */
632 	if (!quot)
633 		quot = baud_base / 9600;
634 	info->quot = quot;
635 	info->timeout = (XMIT_FIFO_SIZE*HZ*bits*quot) / baud_base;
636 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
637 
638 	/* CTS flow control flag and modem status interrupts */
639 	info->IER &= ~UART_IER_MSI;
640 	if (port->flags & ASYNC_HARDPPS_CD)
641 		info->IER |= UART_IER_MSI;
642 	tty_port_set_cts_flow(port, cflag & CRTSCTS);
643 	if (cflag & CRTSCTS)
644 		info->IER |= UART_IER_MSI;
645 	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
646 	if (~cflag & CLOCAL)
647 		info->IER |= UART_IER_MSI;
648 	/* TBD:
649 	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
650 	 */
651 
652 	/*
653 	 * Set up parity check flag
654 	 */
655 
656 	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
657 	if (I_INPCK(tty))
658 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
659 	if (I_BRKINT(tty) || I_PARMRK(tty))
660 		info->read_status_mask |= UART_LSR_BI;
661 
662 	/*
663 	 * Characters to ignore
664 	 */
665 	info->ignore_status_mask = 0;
666 	if (I_IGNPAR(tty))
667 		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
668 	if (I_IGNBRK(tty)) {
669 		info->ignore_status_mask |= UART_LSR_BI;
670 		/*
671 		 * If we're ignore parity and break indicators, ignore
672 		 * overruns too.  (For real raw support).
673 		 */
674 		if (I_IGNPAR(tty))
675 			info->ignore_status_mask |= UART_LSR_OE;
676 	}
677 	/*
678 	 * !!! ignore all characters if CREAD is not set
679 	 */
680 	if ((cflag & CREAD) == 0)
681 		info->ignore_status_mask |= UART_LSR_DR;
682 	local_irq_save(flags);
683 
684 	{
685 	  short serper;
686 
687 	/* Set up the baud rate */
688 	  serper = quot - 1;
689 
690 	/* Enable or disable parity bit */
691 
692 	if(cval & UART_LCR_PARITY)
693 	  serper |= (SERPER_PARENB);
694 
695 	amiga_custom.serper = serper;
696 	mb();
697 	}
698 
699 	local_irq_restore(flags);
700 }
701 
702 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
703 {
704 	struct serial_state *info;
705 	unsigned long flags;
706 
707 	info = tty->driver_data;
708 
709 	if (!info->xmit.buf)
710 		return 0;
711 
712 	local_irq_save(flags);
713 	if (CIRC_SPACE(info->xmit.head,
714 		       info->xmit.tail,
715 		       SERIAL_XMIT_SIZE) == 0) {
716 		local_irq_restore(flags);
717 		return 0;
718 	}
719 
720 	info->xmit.buf[info->xmit.head++] = ch;
721 	info->xmit.head &= SERIAL_XMIT_SIZE-1;
722 	local_irq_restore(flags);
723 	return 1;
724 }
725 
726 static void rs_flush_chars(struct tty_struct *tty)
727 {
728 	struct serial_state *info = tty->driver_data;
729 	unsigned long flags;
730 
731 	if (info->xmit.head == info->xmit.tail
732 	    || tty->flow.stopped
733 	    || tty->hw_stopped
734 	    || !info->xmit.buf)
735 		return;
736 
737 	local_irq_save(flags);
738 	info->IER |= UART_IER_THRI;
739 	amiga_custom.intena = IF_SETCLR | IF_TBE;
740 	mb();
741 	/* set a pending Tx Interrupt, transmitter should restart now */
742 	amiga_custom.intreq = IF_SETCLR | IF_TBE;
743 	mb();
744 	local_irq_restore(flags);
745 }
746 
747 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
748 {
749 	int	c, ret = 0;
750 	struct serial_state *info = tty->driver_data;
751 	unsigned long flags;
752 
753 	if (!info->xmit.buf)
754 		return 0;
755 
756 	local_irq_save(flags);
757 	while (1) {
758 		c = CIRC_SPACE_TO_END(info->xmit.head,
759 				      info->xmit.tail,
760 				      SERIAL_XMIT_SIZE);
761 		if (count < c)
762 			c = count;
763 		if (c <= 0) {
764 			break;
765 		}
766 		memcpy(info->xmit.buf + info->xmit.head, buf, c);
767 		info->xmit.head = ((info->xmit.head + c) &
768 				   (SERIAL_XMIT_SIZE-1));
769 		buf += c;
770 		count -= c;
771 		ret += c;
772 	}
773 	local_irq_restore(flags);
774 
775 	if (info->xmit.head != info->xmit.tail
776 	    && !tty->flow.stopped
777 	    && !tty->hw_stopped
778 	    && !(info->IER & UART_IER_THRI)) {
779 		info->IER |= UART_IER_THRI;
780 		local_irq_disable();
781 		amiga_custom.intena = IF_SETCLR | IF_TBE;
782 		mb();
783 		/* set a pending Tx Interrupt, transmitter should restart now */
784 		amiga_custom.intreq = IF_SETCLR | IF_TBE;
785 		mb();
786 		local_irq_restore(flags);
787 	}
788 	return ret;
789 }
790 
791 static unsigned int rs_write_room(struct tty_struct *tty)
792 {
793 	struct serial_state *info = tty->driver_data;
794 
795 	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
796 }
797 
798 static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
799 {
800 	struct serial_state *info = tty->driver_data;
801 
802 	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
803 }
804 
805 static void rs_flush_buffer(struct tty_struct *tty)
806 {
807 	struct serial_state *info = tty->driver_data;
808 	unsigned long flags;
809 
810 	local_irq_save(flags);
811 	info->xmit.head = info->xmit.tail = 0;
812 	local_irq_restore(flags);
813 	tty_wakeup(tty);
814 }
815 
816 /*
817  * This function is used to send a high-priority XON/XOFF character to
818  * the device
819  */
820 static void rs_send_xchar(struct tty_struct *tty, char ch)
821 {
822 	struct serial_state *info = tty->driver_data;
823         unsigned long flags;
824 
825 	info->x_char = ch;
826 	if (ch) {
827 		/* Make sure transmit interrupts are on */
828 
829 	        /* Check this ! */
830 	        local_irq_save(flags);
831 		if(!(amiga_custom.intenar & IF_TBE)) {
832 		    amiga_custom.intena = IF_SETCLR | IF_TBE;
833 		    mb();
834 		    /* set a pending Tx Interrupt, transmitter should restart now */
835 		    amiga_custom.intreq = IF_SETCLR | IF_TBE;
836 		    mb();
837 		}
838 		local_irq_restore(flags);
839 
840 		info->IER |= UART_IER_THRI;
841 	}
842 }
843 
844 /*
845  * ------------------------------------------------------------
846  * rs_throttle()
847  *
848  * This routine is called by the upper-layer tty layer to signal that
849  * incoming characters should be throttled.
850  * ------------------------------------------------------------
851  */
852 static void rs_throttle(struct tty_struct * tty)
853 {
854 	struct serial_state *info = tty->driver_data;
855 	unsigned long flags;
856 #ifdef SERIAL_DEBUG_THROTTLE
857 	printk("throttle %s ....\n", tty_name(tty));
858 #endif
859 
860 	if (I_IXOFF(tty))
861 		rs_send_xchar(tty, STOP_CHAR(tty));
862 
863 	if (C_CRTSCTS(tty))
864 		info->MCR &= ~SER_RTS;
865 
866 	local_irq_save(flags);
867 	rtsdtr_ctrl(info->MCR);
868 	local_irq_restore(flags);
869 }
870 
871 static void rs_unthrottle(struct tty_struct * tty)
872 {
873 	struct serial_state *info = tty->driver_data;
874 	unsigned long flags;
875 #ifdef SERIAL_DEBUG_THROTTLE
876 	printk("unthrottle %s ....\n", tty_name(tty));
877 #endif
878 
879 	if (I_IXOFF(tty)) {
880 		if (info->x_char)
881 			info->x_char = 0;
882 		else
883 			rs_send_xchar(tty, START_CHAR(tty));
884 	}
885 	if (C_CRTSCTS(tty))
886 		info->MCR |= SER_RTS;
887 	local_irq_save(flags);
888 	rtsdtr_ctrl(info->MCR);
889 	local_irq_restore(flags);
890 }
891 
892 /*
893  * ------------------------------------------------------------
894  * rs_ioctl() and friends
895  * ------------------------------------------------------------
896  */
897 
898 static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
899 {
900 	struct serial_state *state = tty->driver_data;
901 	unsigned int close_delay, closing_wait;
902 
903 	tty_lock(tty);
904 	close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
905 	closing_wait = state->tport.closing_wait;
906 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
907 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
908 
909 	ss->line = tty->index;
910 	ss->port = state->port;
911 	ss->flags = state->tport.flags;
912 	ss->xmit_fifo_size = XMIT_FIFO_SIZE;
913 	ss->baud_base = state->baud_base;
914 	ss->close_delay = close_delay;
915 	ss->closing_wait = closing_wait;
916 	ss->custom_divisor = state->custom_divisor;
917 	tty_unlock(tty);
918 	return 0;
919 }
920 
921 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
922 {
923 	struct serial_state *state = tty->driver_data;
924 	struct tty_port *port = &state->tport;
925 	bool change_spd;
926 	int 			retval = 0;
927 	unsigned int close_delay, closing_wait;
928 
929 	tty_lock(tty);
930 	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
931 		ss->custom_divisor != state->custom_divisor;
932 	if (ss->irq || ss->port != state->port ||
933 			ss->xmit_fifo_size != XMIT_FIFO_SIZE) {
934 		tty_unlock(tty);
935 		return -EINVAL;
936 	}
937 
938 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
939 	closing_wait = ss->closing_wait;
940 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
941 		closing_wait = msecs_to_jiffies(closing_wait * 10);
942 
943 	if (!capable(CAP_SYS_ADMIN)) {
944 		if ((ss->baud_base != state->baud_base) ||
945 		    (close_delay != port->close_delay) ||
946 		    (closing_wait != port->closing_wait) ||
947 		    ((ss->flags & ~ASYNC_USR_MASK) !=
948 		     (port->flags & ~ASYNC_USR_MASK))) {
949 			tty_unlock(tty);
950 			return -EPERM;
951 		}
952 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
953 			       (ss->flags & ASYNC_USR_MASK));
954 		state->custom_divisor = ss->custom_divisor;
955 		goto check_and_exit;
956 	}
957 
958 	if (ss->baud_base < 9600) {
959 		tty_unlock(tty);
960 		return -EINVAL;
961 	}
962 
963 	/*
964 	 * OK, past this point, all the error checking has been done.
965 	 * At this point, we start making changes.....
966 	 */
967 
968 	state->baud_base = ss->baud_base;
969 	port->flags = ((port->flags & ~ASYNC_FLAGS) |
970 			(ss->flags & ASYNC_FLAGS));
971 	state->custom_divisor = ss->custom_divisor;
972 	port->close_delay = close_delay;
973 	port->closing_wait = closing_wait;
974 
975 check_and_exit:
976 	if (tty_port_initialized(port)) {
977 		if (change_spd) {
978 			/* warn about deprecation unless clearing */
979 			if (ss->flags & ASYNC_SPD_MASK)
980 				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
981 			change_speed(tty, state, NULL);
982 		}
983 	} else
984 		retval = startup(tty, state);
985 	tty_unlock(tty);
986 	return retval;
987 }
988 
989 /*
990  * get_lsr_info - get line status register info
991  *
992  * Purpose: Let user call ioctl() to get info when the UART physically
993  * 	    is emptied.  On bus types like RS485, the transmitter must
994  * 	    release the bus after transmitting. This must be done when
995  * 	    the transmit shift register is empty, not be done when the
996  * 	    transmit holding register is empty.  This functionality
997  * 	    allows an RS485 driver to be written in user space.
998  */
999 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
1000 {
1001 	unsigned char status;
1002 	unsigned int result;
1003 	unsigned long flags;
1004 
1005 	local_irq_save(flags);
1006 	status = amiga_custom.serdatr;
1007 	mb();
1008 	local_irq_restore(flags);
1009 	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1010 	if (copy_to_user(value, &result, sizeof(int)))
1011 		return -EFAULT;
1012 	return 0;
1013 }
1014 
1015 
1016 static int rs_tiocmget(struct tty_struct *tty)
1017 {
1018 	struct serial_state *info = tty->driver_data;
1019 	unsigned char control, status;
1020 	unsigned long flags;
1021 
1022 	if (tty_io_error(tty))
1023 		return -EIO;
1024 
1025 	control = info->MCR;
1026 	local_irq_save(flags);
1027 	status = ciab.pra;
1028 	local_irq_restore(flags);
1029 	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1030 		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1031 		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1032 		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1033 		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1034 }
1035 
1036 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1037 						unsigned int clear)
1038 {
1039 	struct serial_state *info = tty->driver_data;
1040 	unsigned long flags;
1041 
1042 	if (tty_io_error(tty))
1043 		return -EIO;
1044 
1045 	local_irq_save(flags);
1046 	if (set & TIOCM_RTS)
1047 		info->MCR |= SER_RTS;
1048 	if (set & TIOCM_DTR)
1049 		info->MCR |= SER_DTR;
1050 	if (clear & TIOCM_RTS)
1051 		info->MCR &= ~SER_RTS;
1052 	if (clear & TIOCM_DTR)
1053 		info->MCR &= ~SER_DTR;
1054 	rtsdtr_ctrl(info->MCR);
1055 	local_irq_restore(flags);
1056 	return 0;
1057 }
1058 
1059 /*
1060  * rs_break() --- routine which turns the break handling on or off
1061  */
1062 static int rs_break(struct tty_struct *tty, int break_state)
1063 {
1064 	unsigned long flags;
1065 
1066 	local_irq_save(flags);
1067 	if (break_state == -1)
1068 	  amiga_custom.adkcon = AC_SETCLR | AC_UARTBRK;
1069 	else
1070 	  amiga_custom.adkcon = AC_UARTBRK;
1071 	mb();
1072 	local_irq_restore(flags);
1073 	return 0;
1074 }
1075 
1076 /*
1077  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1078  * Return: write counters to the user passed counter struct
1079  * NB: both 1->0 and 0->1 transitions are counted except for
1080  *     RI where only 0->1 is counted.
1081  */
1082 static int rs_get_icount(struct tty_struct *tty,
1083 				struct serial_icounter_struct *icount)
1084 {
1085 	struct serial_state *info = tty->driver_data;
1086 	struct async_icount cnow;
1087 	unsigned long flags;
1088 
1089 	local_irq_save(flags);
1090 	cnow = info->icount;
1091 	local_irq_restore(flags);
1092 	icount->cts = cnow.cts;
1093 	icount->dsr = cnow.dsr;
1094 	icount->rng = cnow.rng;
1095 	icount->dcd = cnow.dcd;
1096 	icount->rx = cnow.rx;
1097 	icount->tx = cnow.tx;
1098 	icount->frame = cnow.frame;
1099 	icount->overrun = cnow.overrun;
1100 	icount->parity = cnow.parity;
1101 	icount->brk = cnow.brk;
1102 	icount->buf_overrun = cnow.buf_overrun;
1103 
1104 	return 0;
1105 }
1106 
1107 static int rs_ioctl(struct tty_struct *tty,
1108 		    unsigned int cmd, unsigned long arg)
1109 {
1110 	struct serial_state *info = tty->driver_data;
1111 	struct async_icount cprev, cnow;	/* kernel counter temps */
1112 	void __user *argp = (void __user *)arg;
1113 	unsigned long flags;
1114 	DEFINE_WAIT(wait);
1115 	int ret;
1116 
1117 	if ((cmd != TIOCSERCONFIG) &&
1118 	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1119 		if (tty_io_error(tty))
1120 		    return -EIO;
1121 	}
1122 
1123 	switch (cmd) {
1124 		case TIOCSERCONFIG:
1125 			return 0;
1126 
1127 		case TIOCSERGETLSR: /* Get line status register */
1128 			return get_lsr_info(info, argp);
1129 
1130 		/*
1131 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1132 		 * - mask passed in arg for lines of interest
1133  		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1134 		 * Caller should use TIOCGICOUNT to see which one it was
1135 		 */
1136 		case TIOCMIWAIT:
1137 			local_irq_save(flags);
1138 			/* note the counters on entry */
1139 			cprev = info->icount;
1140 			local_irq_restore(flags);
1141 			while (1) {
1142 				prepare_to_wait(&info->tport.delta_msr_wait,
1143 						&wait, TASK_INTERRUPTIBLE);
1144 				local_irq_save(flags);
1145 				cnow = info->icount; /* atomic copy */
1146 				local_irq_restore(flags);
1147 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1148 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
1149 					ret = -EIO; /* no change => error */
1150 					break;
1151 				}
1152 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1153 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1154 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1155 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1156 					ret = 0;
1157 					break;
1158 				}
1159 				schedule();
1160 				/* see if a signal did it */
1161 				if (signal_pending(current)) {
1162 					ret = -ERESTARTSYS;
1163 					break;
1164 				}
1165 				cprev = cnow;
1166 			}
1167 			finish_wait(&info->tport.delta_msr_wait, &wait);
1168 			return ret;
1169 
1170 		default:
1171 			return -ENOIOCTLCMD;
1172 		}
1173 	return 0;
1174 }
1175 
1176 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1177 {
1178 	struct serial_state *info = tty->driver_data;
1179 	unsigned long flags;
1180 	unsigned int cflag = tty->termios.c_cflag;
1181 
1182 	change_speed(tty, info, old_termios);
1183 
1184 	/* Handle transition to B0 status */
1185 	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
1186 		info->MCR &= ~(SER_DTR|SER_RTS);
1187 		local_irq_save(flags);
1188 		rtsdtr_ctrl(info->MCR);
1189 		local_irq_restore(flags);
1190 	}
1191 
1192 	/* Handle transition away from B0 status */
1193 	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1194 		info->MCR |= SER_DTR;
1195 		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
1196 			info->MCR |= SER_RTS;
1197 		local_irq_save(flags);
1198 		rtsdtr_ctrl(info->MCR);
1199 		local_irq_restore(flags);
1200 	}
1201 
1202 	/* Handle turning off CRTSCTS */
1203 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1204 		tty->hw_stopped = 0;
1205 		rs_start(tty);
1206 	}
1207 
1208 #if 0
1209 	/*
1210 	 * No need to wake up processes in open wait, since they
1211 	 * sample the CLOCAL flag once, and don't recheck it.
1212 	 * XXX  It's not clear whether the current behavior is correct
1213 	 * or not.  Hence, this may change.....
1214 	 */
1215 	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
1216 		wake_up_interruptible(&info->open_wait);
1217 #endif
1218 }
1219 
1220 /*
1221  * ------------------------------------------------------------
1222  * rs_close()
1223  *
1224  * This routine is called when the serial port gets closed.  First, we
1225  * wait for the last remaining data to be sent.  Then, we unlink its
1226  * async structure from the interrupt chain if necessary, and we free
1227  * that IRQ if nothing is left in the chain.
1228  * ------------------------------------------------------------
1229  */
1230 static void rs_close(struct tty_struct *tty, struct file * filp)
1231 {
1232 	struct serial_state *state = tty->driver_data;
1233 	struct tty_port *port = &state->tport;
1234 
1235 	if (tty_port_close_start(port, tty, filp) == 0)
1236 		return;
1237 
1238 	/*
1239 	 * At this point we stop accepting input.  To do this, we
1240 	 * disable the receive line status interrupts, and tell the
1241 	 * interrupt driver to stop checking the data ready bit in the
1242 	 * line status register.
1243 	 */
1244 	state->read_status_mask &= ~UART_LSR_DR;
1245 	if (tty_port_initialized(port)) {
1246 	        /* disable receive interrupts */
1247 	        amiga_custom.intena = IF_RBF;
1248 		mb();
1249 		/* clear any pending receive interrupt */
1250 		amiga_custom.intreq = IF_RBF;
1251 		mb();
1252 
1253 		/*
1254 		 * Before we drop DTR, make sure the UART transmitter
1255 		 * has completely drained; this is especially
1256 		 * important if there is a transmit FIFO!
1257 		 */
1258 		rs_wait_until_sent(tty, state->timeout);
1259 	}
1260 	shutdown(tty, state);
1261 	rs_flush_buffer(tty);
1262 
1263 	tty_ldisc_flush(tty);
1264 	port->tty = NULL;
1265 
1266 	tty_port_close_end(port, tty);
1267 }
1268 
1269 /*
1270  * rs_wait_until_sent() --- wait until the transmitter is empty
1271  */
1272 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1273 {
1274 	struct serial_state *info = tty->driver_data;
1275 	unsigned long orig_jiffies, char_time;
1276 	int lsr;
1277 
1278 	orig_jiffies = jiffies;
1279 
1280 	/*
1281 	 * Set the check interval to be 1/5 of the estimated time to
1282 	 * send a single character, and make it at least 1.  The check
1283 	 * interval should also be less than the timeout.
1284 	 *
1285 	 * Note: we have to use pretty tight timings here to satisfy
1286 	 * the NIST-PCTS.
1287 	 */
1288 	char_time = (info->timeout - HZ/50) / XMIT_FIFO_SIZE;
1289 	char_time = char_time / 5;
1290 	if (char_time == 0)
1291 		char_time = 1;
1292 	if (timeout)
1293 	  char_time = min_t(unsigned long, char_time, timeout);
1294 	/*
1295 	 * If the transmitter hasn't cleared in twice the approximate
1296 	 * amount of time to send the entire FIFO, it probably won't
1297 	 * ever clear.  This assumes the UART isn't doing flow
1298 	 * control, which is currently the case.  Hence, if it ever
1299 	 * takes longer than info->timeout, this is probably due to a
1300 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1301 	 * 2*info->timeout.
1302 	 */
1303 	if (!timeout || timeout > 2*info->timeout)
1304 		timeout = 2*info->timeout;
1305 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1306 	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1307 	printk("jiff=%lu...", jiffies);
1308 #endif
1309 	while(!((lsr = amiga_custom.serdatr) & SDR_TSRE)) {
1310 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1311 		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1312 #endif
1313 		msleep_interruptible(jiffies_to_msecs(char_time));
1314 		if (signal_pending(current))
1315 			break;
1316 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1317 			break;
1318 	}
1319 	__set_current_state(TASK_RUNNING);
1320 
1321 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1322 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1323 #endif
1324 }
1325 
1326 /*
1327  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1328  */
1329 static void rs_hangup(struct tty_struct *tty)
1330 {
1331 	struct serial_state *info = tty->driver_data;
1332 
1333 	rs_flush_buffer(tty);
1334 	shutdown(tty, info);
1335 	info->tport.count = 0;
1336 	tty_port_set_active(&info->tport, 0);
1337 	info->tport.tty = NULL;
1338 	wake_up_interruptible(&info->tport.open_wait);
1339 }
1340 
1341 /*
1342  * This routine is called whenever a serial port is opened.  It
1343  * enables interrupts for a serial port, linking in its async structure into
1344  * the IRQ chain.   It also performs the serial-specific
1345  * initialization for the tty structure.
1346  */
1347 static int rs_open(struct tty_struct *tty, struct file * filp)
1348 {
1349 	struct tty_port *port = tty->port;
1350 	struct serial_state *info = container_of(port, struct serial_state,
1351 			tport);
1352 	int retval;
1353 
1354 	port->count++;
1355 	port->tty = tty;
1356 	tty->driver_data = info;
1357 
1358 	retval = startup(tty, info);
1359 	if (retval) {
1360 		return retval;
1361 	}
1362 
1363 	return tty_port_block_til_ready(port, tty, filp);
1364 }
1365 
1366 /*
1367  * /proc fs routines....
1368  */
1369 
1370 static inline void line_info(struct seq_file *m, int line,
1371 		struct serial_state *state)
1372 {
1373 	char	stat_buf[30], control, status;
1374 	unsigned long flags;
1375 
1376 	seq_printf(m, "%d: uart:amiga_builtin", line);
1377 
1378 	local_irq_save(flags);
1379 	status = ciab.pra;
1380 	control = tty_port_initialized(&state->tport) ? state->MCR : status;
1381 	local_irq_restore(flags);
1382 
1383 	stat_buf[0] = 0;
1384 	stat_buf[1] = 0;
1385 	if(!(control & SER_RTS))
1386 		strcat(stat_buf, "|RTS");
1387 	if(!(status & SER_CTS))
1388 		strcat(stat_buf, "|CTS");
1389 	if(!(control & SER_DTR))
1390 		strcat(stat_buf, "|DTR");
1391 	if(!(status & SER_DSR))
1392 		strcat(stat_buf, "|DSR");
1393 	if(!(status & SER_DCD))
1394 		strcat(stat_buf, "|CD");
1395 
1396 	if (state->quot)
1397 		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1398 
1399 	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1400 
1401 	if (state->icount.frame)
1402 		seq_printf(m, " fe:%d", state->icount.frame);
1403 
1404 	if (state->icount.parity)
1405 		seq_printf(m, " pe:%d", state->icount.parity);
1406 
1407 	if (state->icount.brk)
1408 		seq_printf(m, " brk:%d", state->icount.brk);
1409 
1410 	if (state->icount.overrun)
1411 		seq_printf(m, " oe:%d", state->icount.overrun);
1412 
1413 	/*
1414 	 * Last thing is the RS-232 status lines
1415 	 */
1416 	seq_printf(m, " %s\n", stat_buf+1);
1417 }
1418 
1419 static int rs_proc_show(struct seq_file *m, void *v)
1420 {
1421 	seq_printf(m, "serinfo:1.0 driver:4.30\n");
1422 	line_info(m, 0, &serial_state);
1423 	return 0;
1424 }
1425 
1426 /*
1427  * ---------------------------------------------------------------------
1428  * rs_init() and friends
1429  *
1430  * rs_init() is called at boot-time to initialize the serial driver.
1431  * ---------------------------------------------------------------------
1432  */
1433 
1434 static const struct tty_operations serial_ops = {
1435 	.open = rs_open,
1436 	.close = rs_close,
1437 	.write = rs_write,
1438 	.put_char = rs_put_char,
1439 	.flush_chars = rs_flush_chars,
1440 	.write_room = rs_write_room,
1441 	.chars_in_buffer = rs_chars_in_buffer,
1442 	.flush_buffer = rs_flush_buffer,
1443 	.ioctl = rs_ioctl,
1444 	.throttle = rs_throttle,
1445 	.unthrottle = rs_unthrottle,
1446 	.set_termios = rs_set_termios,
1447 	.stop = rs_stop,
1448 	.start = rs_start,
1449 	.hangup = rs_hangup,
1450 	.break_ctl = rs_break,
1451 	.send_xchar = rs_send_xchar,
1452 	.wait_until_sent = rs_wait_until_sent,
1453 	.tiocmget = rs_tiocmget,
1454 	.tiocmset = rs_tiocmset,
1455 	.get_icount = rs_get_icount,
1456 	.set_serial = set_serial_info,
1457 	.get_serial = get_serial_info,
1458 	.proc_show = rs_proc_show,
1459 };
1460 
1461 static int amiga_carrier_raised(struct tty_port *port)
1462 {
1463 	return !(ciab.pra & SER_DCD);
1464 }
1465 
1466 static void amiga_dtr_rts(struct tty_port *port, int raise)
1467 {
1468 	struct serial_state *info = container_of(port, struct serial_state,
1469 			tport);
1470 	unsigned long flags;
1471 
1472 	if (raise)
1473 		info->MCR |= SER_DTR|SER_RTS;
1474 	else
1475 		info->MCR &= ~(SER_DTR|SER_RTS);
1476 
1477 	local_irq_save(flags);
1478 	rtsdtr_ctrl(info->MCR);
1479 	local_irq_restore(flags);
1480 }
1481 
1482 static const struct tty_port_operations amiga_port_ops = {
1483 	.carrier_raised = amiga_carrier_raised,
1484 	.dtr_rts = amiga_dtr_rts,
1485 };
1486 
1487 /*
1488  * The serial driver boot-time initialization code!
1489  */
1490 static int __init amiga_serial_probe(struct platform_device *pdev)
1491 {
1492 	struct serial_state *state = &serial_state;
1493 	struct tty_driver *driver;
1494 	unsigned long flags;
1495 	int error;
1496 
1497 	driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
1498 	if (IS_ERR(driver))
1499 		return PTR_ERR(driver);
1500 
1501 	/* Initialize the tty_driver structure */
1502 
1503 	driver->driver_name = "amiserial";
1504 	driver->name = "ttyS";
1505 	driver->major = TTY_MAJOR;
1506 	driver->minor_start = 64;
1507 	driver->type = TTY_DRIVER_TYPE_SERIAL;
1508 	driver->subtype = SERIAL_TYPE_NORMAL;
1509 	driver->init_termios = tty_std_termios;
1510 	driver->init_termios.c_cflag =
1511 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1512 	tty_set_operations(driver, &serial_ops);
1513 
1514 	memset(state, 0, sizeof(*state));
1515 	state->port = (int)&amiga_custom.serdatr; /* Just to give it a value */
1516 	tty_port_init(&state->tport);
1517 	state->tport.ops = &amiga_port_ops;
1518 	tty_port_link_device(&state->tport, driver, 0);
1519 
1520 	error = tty_register_driver(driver);
1521 	if (error)
1522 		goto fail_tty_driver_kref_put;
1523 
1524 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1525 
1526 	/* Hardware set up */
1527 
1528 	state->baud_base = amiga_colorclock;
1529 
1530 	/* set ISRs, and then disable the rx interrupts */
1531 	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1532 	if (error)
1533 		goto fail_unregister;
1534 
1535 	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1536 			    "serial RX", state);
1537 	if (error)
1538 		goto fail_free_irq;
1539 
1540 	local_irq_save(flags);
1541 
1542 	/* turn off Rx and Tx interrupts */
1543 	amiga_custom.intena = IF_RBF | IF_TBE;
1544 	mb();
1545 
1546 	/* clear any pending interrupt */
1547 	amiga_custom.intreq = IF_RBF | IF_TBE;
1548 	mb();
1549 
1550 	local_irq_restore(flags);
1551 
1552 	/*
1553 	 * set the appropriate directions for the modem control flags,
1554 	 * and clear RTS and DTR
1555 	 */
1556 	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1557 	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1558 
1559 	platform_set_drvdata(pdev, state);
1560 
1561 	serial_driver = driver;
1562 
1563 	return 0;
1564 
1565 fail_free_irq:
1566 	free_irq(IRQ_AMIGA_TBE, state);
1567 fail_unregister:
1568 	tty_unregister_driver(driver);
1569 fail_tty_driver_kref_put:
1570 	tty_port_destroy(&state->tport);
1571 	tty_driver_kref_put(driver);
1572 	return error;
1573 }
1574 
1575 static int __exit amiga_serial_remove(struct platform_device *pdev)
1576 {
1577 	struct serial_state *state = platform_get_drvdata(pdev);
1578 
1579 	tty_unregister_driver(serial_driver);
1580 	tty_driver_kref_put(serial_driver);
1581 	tty_port_destroy(&state->tport);
1582 
1583 	free_irq(IRQ_AMIGA_TBE, state);
1584 	free_irq(IRQ_AMIGA_RBF, state);
1585 
1586 	return 0;
1587 }
1588 
1589 static struct platform_driver amiga_serial_driver = {
1590 	.remove = __exit_p(amiga_serial_remove),
1591 	.driver   = {
1592 		.name	= "amiga-serial",
1593 	},
1594 };
1595 
1596 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1597 
1598 
1599 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1600 
1601 /*
1602  * ------------------------------------------------------------
1603  * Serial console driver
1604  * ------------------------------------------------------------
1605  */
1606 
1607 static void amiga_serial_putc(char c)
1608 {
1609 	amiga_custom.serdat = (unsigned char)c | 0x100;
1610 	while (!(amiga_custom.serdatr & 0x2000))
1611 		barrier();
1612 }
1613 
1614 /*
1615  *	Print a string to the serial port trying not to disturb
1616  *	any possible real use of the port...
1617  *
1618  *	The console must be locked when we get here.
1619  */
1620 static void serial_console_write(struct console *co, const char *s,
1621 				unsigned count)
1622 {
1623 	unsigned short intena = amiga_custom.intenar;
1624 
1625 	amiga_custom.intena = IF_TBE;
1626 
1627 	while (count--) {
1628 		if (*s == '\n')
1629 			amiga_serial_putc('\r');
1630 		amiga_serial_putc(*s++);
1631 	}
1632 
1633 	amiga_custom.intena = IF_SETCLR | (intena & IF_TBE);
1634 }
1635 
1636 static struct tty_driver *serial_console_device(struct console *c, int *index)
1637 {
1638 	*index = 0;
1639 	return serial_driver;
1640 }
1641 
1642 static struct console sercons = {
1643 	.name =		"ttyS",
1644 	.write =	serial_console_write,
1645 	.device =	serial_console_device,
1646 	.flags =	CON_PRINTBUFFER,
1647 	.index =	-1,
1648 };
1649 
1650 /*
1651  *	Register console.
1652  */
1653 static int __init amiserial_console_init(void)
1654 {
1655 	if (!MACH_IS_AMIGA)
1656 		return -ENODEV;
1657 
1658 	register_console(&sercons);
1659 	return 0;
1660 }
1661 console_initcall(amiserial_console_init);
1662 
1663 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1664 
1665 MODULE_LICENSE("GPL");
1666 MODULE_ALIAS("platform:amiga-serial");
1667