xref: /linux/drivers/tty/amiserial.c (revision 1dd0dd0b1fefd1e51cfaddf62316f759fde7de7d)
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 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/serial_core.h>
55 #include <linux/sched.h>
56 #include <linux/signal.h>
57 #include <linux/slab.h>
58 #include <linux/string.h>
59 #include <linux/timer.h>
60 #include <linux/tty_flip.h>
61 #include <linux/tty.h>
62 #include <linux/types.h>
63 #include <linux/uaccess.h>
64 
65 #include <asm/amigahw.h>
66 #include <asm/amigaints.h>
67 #include <asm/irq.h>
68 #include <asm/setup.h>
69 
70 struct serial_state {
71 	struct tty_port		tport;
72 	struct circ_buf		xmit;
73 	struct async_icount	icount;
74 
75 	unsigned long		port;
76 	int			baud_base;
77 	int			custom_divisor;
78 	int			read_status_mask;
79 	int			ignore_status_mask;
80 	int			timeout;
81 	int			quot;
82 	int			IER; 	/* Interrupt Enable Register */
83 	int			MCR; 	/* Modem control register */
84 	int			x_char;	/* xon/xoff character */
85 };
86 
87 static struct tty_driver *serial_driver;
88 
89 /* number of characters left in xmit buffer before we ask for more */
90 #define WAKEUP_CHARS 256
91 
92 #define XMIT_FIFO_SIZE 1
93 
94 static unsigned char current_ctl_bits;
95 
96 static void change_speed(struct tty_struct *tty, struct serial_state *info,
97 		struct ktermios *old);
98 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
99 
100 
101 static struct serial_state serial_state;
102 
103 /* some serial hardware definitions */
104 #define SDR_OVRUN   (1<<15)
105 #define SDR_RBF     (1<<14)
106 #define SDR_TBE     (1<<13)
107 #define SDR_TSRE    (1<<12)
108 
109 #define SERPER_PARENB    (1<<15)
110 
111 #define AC_SETCLR   (1<<15)
112 #define AC_UARTBRK  (1<<11)
113 
114 #define SER_DTR     (1<<7)
115 #define SER_RTS     (1<<6)
116 #define SER_DCD     (1<<5)
117 #define SER_CTS     (1<<4)
118 #define SER_DSR     (1<<3)
119 
120 static __inline__ void rtsdtr_ctrl(int bits)
121 {
122     ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
123 }
124 
125 /*
126  * ------------------------------------------------------------
127  * rs_stop() and rs_start()
128  *
129  * This routines are called before setting or resetting tty->flow.stopped.
130  * They enable or disable transmitter interrupts, as necessary.
131  * ------------------------------------------------------------
132  */
133 static void rs_stop(struct tty_struct *tty)
134 {
135 	struct serial_state *info = tty->driver_data;
136 	unsigned long flags;
137 
138 	local_irq_save(flags);
139 	if (info->IER & UART_IER_THRI) {
140 		info->IER &= ~UART_IER_THRI;
141 		/* disable Tx interrupt and remove any pending interrupts */
142 		amiga_custom.intena = IF_TBE;
143 		mb();
144 		amiga_custom.intreq = IF_TBE;
145 		mb();
146 	}
147 	local_irq_restore(flags);
148 }
149 
150 static void rs_start(struct tty_struct *tty)
151 {
152 	struct serial_state *info = tty->driver_data;
153 	unsigned long flags;
154 
155 	local_irq_save(flags);
156 	if (info->xmit.head != info->xmit.tail
157 	    && info->xmit.buf
158 	    && !(info->IER & UART_IER_THRI)) {
159 		info->IER |= UART_IER_THRI;
160 		amiga_custom.intena = IF_SETCLR | IF_TBE;
161 		mb();
162 		/* set a pending Tx Interrupt, transmitter should restart now */
163 		amiga_custom.intreq = IF_SETCLR | IF_TBE;
164 		mb();
165 	}
166 	local_irq_restore(flags);
167 }
168 
169 /*
170  * ----------------------------------------------------------------------
171  *
172  * Here start the interrupt handling routines.
173  *
174  * -----------------------------------------------------------------------
175  */
176 
177 static void receive_chars(struct serial_state *info)
178 {
179         int status;
180 	int serdatr;
181 	unsigned char ch, flag;
182 	struct	async_icount *icount;
183 	int oe = 0;
184 
185 	icount = &info->icount;
186 
187 	status = UART_LSR_DR; /* We obviously have a character! */
188 	serdatr = amiga_custom.serdatr;
189 	mb();
190 	amiga_custom.intreq = IF_RBF;
191 	mb();
192 
193 	if((serdatr & 0x1ff) == 0)
194 	    status |= UART_LSR_BI;
195 	if(serdatr & SDR_OVRUN)
196 	    status |= UART_LSR_OE;
197 
198 	ch = serdatr & 0xff;
199 	icount->rx++;
200 
201 #ifdef SERIAL_DEBUG_INTR
202 	printk("DR%02x:%02x...", ch, status);
203 #endif
204 	flag = TTY_NORMAL;
205 
206 	/*
207 	 * We don't handle parity or frame errors - but I have left
208 	 * the code in, since I'm not sure that the errors can't be
209 	 * detected.
210 	 */
211 
212 	if (status & (UART_LSR_BI | UART_LSR_PE |
213 		      UART_LSR_FE | UART_LSR_OE)) {
214 	  /*
215 	   * For statistics only
216 	   */
217 	  if (status & UART_LSR_BI) {
218 	    status &= ~(UART_LSR_FE | UART_LSR_PE);
219 	    icount->brk++;
220 	  } else if (status & UART_LSR_PE)
221 	    icount->parity++;
222 	  else if (status & UART_LSR_FE)
223 	    icount->frame++;
224 	  if (status & UART_LSR_OE)
225 	    icount->overrun++;
226 
227 	  /*
228 	   * Now check to see if character should be
229 	   * ignored, and mask off conditions which
230 	   * should be ignored.
231 	   */
232 	  if (status & info->ignore_status_mask)
233 	    goto out;
234 
235 	  status &= info->read_status_mask;
236 
237 	  if (status & (UART_LSR_BI)) {
238 #ifdef SERIAL_DEBUG_INTR
239 	    printk("handling break....");
240 #endif
241 	    flag = TTY_BREAK;
242 	    if (info->tport.flags & ASYNC_SAK)
243 	      do_SAK(info->tport.tty);
244 	  } else if (status & UART_LSR_PE)
245 	    flag = TTY_PARITY;
246 	  else if (status & UART_LSR_FE)
247 	    flag = TTY_FRAME;
248 	  if (status & UART_LSR_OE) {
249 	    /*
250 	     * Overrun is special, since it's
251 	     * reported immediately, and doesn't
252 	     * affect the current character
253 	     */
254 	     oe = 1;
255 	  }
256 	}
257 	tty_insert_flip_char(&info->tport, ch, flag);
258 	if (oe == 1)
259 		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
260 	tty_flip_buffer_push(&info->tport);
261 out:
262 	return;
263 }
264 
265 static void transmit_chars(struct serial_state *info)
266 {
267 	amiga_custom.intreq = IF_TBE;
268 	mb();
269 	if (info->x_char) {
270 	        amiga_custom.serdat = info->x_char | 0x100;
271 		mb();
272 		info->icount.tx++;
273 		info->x_char = 0;
274 		return;
275 	}
276 	if (info->xmit.head == info->xmit.tail
277 	    || info->tport.tty->flow.stopped
278 	    || info->tport.tty->hw_stopped) {
279 		info->IER &= ~UART_IER_THRI;
280 	        amiga_custom.intena = IF_TBE;
281 		mb();
282 		return;
283 	}
284 
285 	amiga_custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
286 	mb();
287 	info->xmit.tail = info->xmit.tail & (UART_XMIT_SIZE - 1);
288 	info->icount.tx++;
289 
290 	if (CIRC_CNT(info->xmit.head,
291 		     info->xmit.tail,
292 		     UART_XMIT_SIZE) < WAKEUP_CHARS)
293 		tty_wakeup(info->tport.tty);
294 
295 #ifdef SERIAL_DEBUG_INTR
296 	printk("THRE...");
297 #endif
298 	if (info->xmit.head == info->xmit.tail) {
299 	        amiga_custom.intena = IF_TBE;
300 		mb();
301 		info->IER &= ~UART_IER_THRI;
302 	}
303 }
304 
305 static void check_modem_status(struct serial_state *info)
306 {
307 	struct tty_port *port = &info->tport;
308 	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
309 	unsigned char dstatus;
310 	struct	async_icount *icount;
311 
312 	/* Determine bits that have changed */
313 	dstatus = status ^ current_ctl_bits;
314 	current_ctl_bits = status;
315 
316 	if (dstatus) {
317 		icount = &info->icount;
318 		/* update input line counters */
319 		if (dstatus & SER_DSR)
320 			icount->dsr++;
321 		if (dstatus & SER_DCD) {
322 			icount->dcd++;
323 		}
324 		if (dstatus & SER_CTS)
325 			icount->cts++;
326 		wake_up_interruptible(&port->delta_msr_wait);
327 	}
328 
329 	if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
330 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
331 		printk("ttyS%d CD now %s...", info->line,
332 		       (!(status & SER_DCD)) ? "on" : "off");
333 #endif
334 		if (!(status & SER_DCD))
335 			wake_up_interruptible(&port->open_wait);
336 		else {
337 #ifdef SERIAL_DEBUG_OPEN
338 			printk("doing serial hangup...");
339 #endif
340 			if (port->tty)
341 				tty_hangup(port->tty);
342 		}
343 	}
344 	if (tty_port_cts_enabled(port)) {
345 		if (port->tty->hw_stopped) {
346 			if (!(status & SER_CTS)) {
347 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
348 				printk("CTS tx start...");
349 #endif
350 				port->tty->hw_stopped = 0;
351 				info->IER |= UART_IER_THRI;
352 				amiga_custom.intena = IF_SETCLR | IF_TBE;
353 				mb();
354 				/* set a pending Tx Interrupt, transmitter should restart now */
355 				amiga_custom.intreq = IF_SETCLR | IF_TBE;
356 				mb();
357 				tty_wakeup(port->tty);
358 				return;
359 			}
360 		} else {
361 			if ((status & SER_CTS)) {
362 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
363 				printk("CTS tx stop...");
364 #endif
365 				port->tty->hw_stopped = 1;
366 				info->IER &= ~UART_IER_THRI;
367 				/* disable Tx interrupt and remove any pending interrupts */
368 				amiga_custom.intena = IF_TBE;
369 				mb();
370 				amiga_custom.intreq = IF_TBE;
371 				mb();
372 			}
373 		}
374 	}
375 }
376 
377 static irqreturn_t ser_vbl_int( int irq, void *data)
378 {
379         /* vbl is just a periodic interrupt we tie into to update modem status */
380 	struct serial_state *info = data;
381 	/*
382 	 * TBD - is it better to unregister from this interrupt or to
383 	 * ignore it if MSI is clear ?
384 	 */
385 	if(info->IER & UART_IER_MSI)
386 	  check_modem_status(info);
387 	return IRQ_HANDLED;
388 }
389 
390 static irqreturn_t ser_rx_int(int irq, void *dev_id)
391 {
392 	struct serial_state *info = dev_id;
393 
394 #ifdef SERIAL_DEBUG_INTR
395 	printk("ser_rx_int...");
396 #endif
397 
398 	if (!info->tport.tty)
399 		return IRQ_NONE;
400 
401 	receive_chars(info);
402 #ifdef SERIAL_DEBUG_INTR
403 	printk("end.\n");
404 #endif
405 	return IRQ_HANDLED;
406 }
407 
408 static irqreturn_t ser_tx_int(int irq, void *dev_id)
409 {
410 	struct serial_state *info = dev_id;
411 
412 	if (amiga_custom.serdatr & SDR_TBE) {
413 #ifdef SERIAL_DEBUG_INTR
414 	  printk("ser_tx_int...");
415 #endif
416 
417 	  if (!info->tport.tty)
418 		return IRQ_NONE;
419 
420 	  transmit_chars(info);
421 #ifdef SERIAL_DEBUG_INTR
422 	  printk("end.\n");
423 #endif
424 	}
425 	return IRQ_HANDLED;
426 }
427 
428 /*
429  * -------------------------------------------------------------------
430  * Here ends the serial interrupt routines.
431  * -------------------------------------------------------------------
432  */
433 
434 /*
435  * ---------------------------------------------------------------
436  * Low level utility subroutines for the serial driver:  routines to
437  * figure out the appropriate timeout for an interrupt chain, routines
438  * to initialize and startup a serial port, and routines to shutdown a
439  * serial port.  Useful stuff like that.
440  * ---------------------------------------------------------------
441  */
442 
443 static int startup(struct tty_struct *tty, struct serial_state *info)
444 {
445 	struct tty_port *port = &info->tport;
446 	unsigned long flags;
447 	int	retval=0;
448 	unsigned long page;
449 
450 	page = get_zeroed_page(GFP_KERNEL);
451 	if (!page)
452 		return -ENOMEM;
453 
454 	local_irq_save(flags);
455 
456 	if (tty_port_initialized(port)) {
457 		free_page(page);
458 		goto errout;
459 	}
460 
461 	if (info->xmit.buf)
462 		free_page(page);
463 	else
464 		info->xmit.buf = (unsigned char *) page;
465 
466 #ifdef SERIAL_DEBUG_OPEN
467 	printk("starting up ttys%d ...", info->line);
468 #endif
469 
470 	/* Clear anything in the input buffer */
471 
472 	amiga_custom.intreq = IF_RBF;
473 	mb();
474 
475 	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
476 	if (retval) {
477 		if (capable(CAP_SYS_ADMIN)) {
478 			set_bit(TTY_IO_ERROR, &tty->flags);
479 			retval = 0;
480 		}
481 		goto errout;
482 	}
483 
484 	/* enable both Rx and Tx interrupts */
485 	amiga_custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
486 	mb();
487 	info->IER = UART_IER_MSI;
488 
489 	/* remember current state of the DCD and CTS bits */
490 	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
491 
492 	info->MCR = 0;
493 	if (C_BAUD(tty))
494 	  info->MCR = SER_DTR | SER_RTS;
495 	rtsdtr_ctrl(info->MCR);
496 
497 	clear_bit(TTY_IO_ERROR, &tty->flags);
498 	info->xmit.head = info->xmit.tail = 0;
499 
500 	/*
501 	 * and set the speed of the serial port
502 	 */
503 	change_speed(tty, info, NULL);
504 
505 	tty_port_set_initialized(port, 1);
506 	local_irq_restore(flags);
507 	return 0;
508 
509 errout:
510 	local_irq_restore(flags);
511 	return retval;
512 }
513 
514 /*
515  * This routine will shutdown a serial port; interrupts are disabled, and
516  * DTR is dropped if the hangup on close termio flag is on.
517  */
518 static void shutdown(struct tty_struct *tty, struct serial_state *info)
519 {
520 	unsigned long	flags;
521 
522 	if (!tty_port_initialized(&info->tport))
523 		return;
524 
525 #ifdef SERIAL_DEBUG_OPEN
526 	printk("Shutting down serial port %d ....\n", info->line);
527 #endif
528 
529 	local_irq_save(flags); /* Disable interrupts */
530 
531 	/*
532 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
533 	 * here so the queue might never be waken up
534 	 */
535 	wake_up_interruptible(&info->tport.delta_msr_wait);
536 
537 	/*
538 	 * Free the IRQ, if necessary
539 	 */
540 	free_irq(IRQ_AMIGA_VERTB, info);
541 
542 	free_page((unsigned long)info->xmit.buf);
543 	info->xmit.buf = NULL;
544 
545 	info->IER = 0;
546 	amiga_custom.intena = IF_RBF | IF_TBE;
547 	mb();
548 
549 	/* disable break condition */
550 	amiga_custom.adkcon = AC_UARTBRK;
551 	mb();
552 
553 	if (C_HUPCL(tty))
554 		info->MCR &= ~(SER_DTR|SER_RTS);
555 	rtsdtr_ctrl(info->MCR);
556 
557 	set_bit(TTY_IO_ERROR, &tty->flags);
558 
559 	tty_port_set_initialized(&info->tport, 0);
560 	local_irq_restore(flags);
561 }
562 
563 
564 /*
565  * This routine is called to set the UART divisor registers to match
566  * the specified baud rate for a serial port.
567  */
568 static void change_speed(struct tty_struct *tty, struct serial_state *info,
569 			 struct ktermios *old_termios)
570 {
571 	struct tty_port *port = &info->tport;
572 	int	quot = 0, baud_base, baud;
573 	unsigned cflag, cval = 0;
574 	int	bits;
575 	unsigned long	flags;
576 
577 	cflag = tty->termios.c_cflag;
578 
579 	/* Byte size is always 8 bits plus parity bit if requested */
580 
581 	cval = 3; bits = 10;
582 	if (cflag & CSTOPB) {
583 		cval |= 0x04;
584 		bits++;
585 	}
586 	if (cflag & PARENB) {
587 		cval |= UART_LCR_PARITY;
588 		bits++;
589 	}
590 	if (!(cflag & PARODD))
591 		cval |= UART_LCR_EPAR;
592 	if (cflag & CMSPAR)
593 		cval |= UART_LCR_SPAR;
594 
595 	/* Determine divisor based on baud rate */
596 	baud = tty_get_baud_rate(tty);
597 	if (!baud)
598 		baud = 9600;	/* B0 transition handled in rs_set_termios */
599 	baud_base = info->baud_base;
600 	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
601 		quot = info->custom_divisor;
602 	else {
603 		if (baud == 134)
604 			/* Special case since 134 is really 134.5 */
605 			quot = (2*baud_base / 269);
606 		else if (baud)
607 			quot = baud_base / baud;
608 	}
609 	/* If the quotient is zero refuse the change */
610 	if (!quot && old_termios) {
611 		/* FIXME: Will need updating for new tty in the end */
612 		tty->termios.c_cflag &= ~CBAUD;
613 		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
614 		baud = tty_get_baud_rate(tty);
615 		if (!baud)
616 			baud = 9600;
617 		if (baud == 38400 &&
618 		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
619 			quot = info->custom_divisor;
620 		else {
621 			if (baud == 134)
622 				/* Special case since 134 is really 134.5 */
623 				quot = (2*baud_base / 269);
624 			else if (baud)
625 				quot = baud_base / baud;
626 		}
627 	}
628 	/* As a last resort, if the quotient is zero, default to 9600 bps */
629 	if (!quot)
630 		quot = baud_base / 9600;
631 	info->quot = quot;
632 	info->timeout = (XMIT_FIFO_SIZE*HZ*bits*quot) / baud_base;
633 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
634 
635 	/* CTS flow control flag and modem status interrupts */
636 	info->IER &= ~UART_IER_MSI;
637 	if (port->flags & ASYNC_HARDPPS_CD)
638 		info->IER |= UART_IER_MSI;
639 	tty_port_set_cts_flow(port, cflag & CRTSCTS);
640 	if (cflag & CRTSCTS)
641 		info->IER |= UART_IER_MSI;
642 	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
643 	if (~cflag & CLOCAL)
644 		info->IER |= UART_IER_MSI;
645 	/* TBD:
646 	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
647 	 */
648 
649 	/*
650 	 * Set up parity check flag
651 	 */
652 
653 	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
654 	if (I_INPCK(tty))
655 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
656 	if (I_BRKINT(tty) || I_PARMRK(tty))
657 		info->read_status_mask |= UART_LSR_BI;
658 
659 	/*
660 	 * Characters to ignore
661 	 */
662 	info->ignore_status_mask = 0;
663 	if (I_IGNPAR(tty))
664 		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
665 	if (I_IGNBRK(tty)) {
666 		info->ignore_status_mask |= UART_LSR_BI;
667 		/*
668 		 * If we're ignore parity and break indicators, ignore
669 		 * overruns too.  (For real raw support).
670 		 */
671 		if (I_IGNPAR(tty))
672 			info->ignore_status_mask |= UART_LSR_OE;
673 	}
674 	/*
675 	 * !!! ignore all characters if CREAD is not set
676 	 */
677 	if ((cflag & CREAD) == 0)
678 		info->ignore_status_mask |= UART_LSR_DR;
679 	local_irq_save(flags);
680 
681 	{
682 	  short serper;
683 
684 	/* Set up the baud rate */
685 	  serper = quot - 1;
686 
687 	/* Enable or disable parity bit */
688 
689 	if(cval & UART_LCR_PARITY)
690 	  serper |= (SERPER_PARENB);
691 
692 	amiga_custom.serper = serper;
693 	mb();
694 	}
695 
696 	local_irq_restore(flags);
697 }
698 
699 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
700 {
701 	struct serial_state *info;
702 	unsigned long flags;
703 
704 	info = tty->driver_data;
705 
706 	if (!info->xmit.buf)
707 		return 0;
708 
709 	local_irq_save(flags);
710 	if (CIRC_SPACE(info->xmit.head,
711 		       info->xmit.tail,
712 		       UART_XMIT_SIZE) == 0) {
713 		local_irq_restore(flags);
714 		return 0;
715 	}
716 
717 	info->xmit.buf[info->xmit.head++] = ch;
718 	info->xmit.head &= UART_XMIT_SIZE - 1;
719 	local_irq_restore(flags);
720 	return 1;
721 }
722 
723 static void rs_flush_chars(struct tty_struct *tty)
724 {
725 	struct serial_state *info = tty->driver_data;
726 	unsigned long flags;
727 
728 	if (info->xmit.head == info->xmit.tail
729 	    || tty->flow.stopped
730 	    || tty->hw_stopped
731 	    || !info->xmit.buf)
732 		return;
733 
734 	local_irq_save(flags);
735 	info->IER |= UART_IER_THRI;
736 	amiga_custom.intena = IF_SETCLR | IF_TBE;
737 	mb();
738 	/* set a pending Tx Interrupt, transmitter should restart now */
739 	amiga_custom.intreq = IF_SETCLR | IF_TBE;
740 	mb();
741 	local_irq_restore(flags);
742 }
743 
744 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
745 {
746 	int	c, ret = 0;
747 	struct serial_state *info = tty->driver_data;
748 	unsigned long flags;
749 
750 	if (!info->xmit.buf)
751 		return 0;
752 
753 	local_irq_save(flags);
754 	while (1) {
755 		c = CIRC_SPACE_TO_END(info->xmit.head,
756 				      info->xmit.tail,
757 				      UART_XMIT_SIZE);
758 		if (count < c)
759 			c = count;
760 		if (c <= 0) {
761 			break;
762 		}
763 		memcpy(info->xmit.buf + info->xmit.head, buf, c);
764 		info->xmit.head = (info->xmit.head + c) & (UART_XMIT_SIZE - 1);
765 		buf += c;
766 		count -= c;
767 		ret += c;
768 	}
769 	local_irq_restore(flags);
770 
771 	if (info->xmit.head != info->xmit.tail
772 	    && !tty->flow.stopped
773 	    && !tty->hw_stopped
774 	    && !(info->IER & UART_IER_THRI)) {
775 		info->IER |= UART_IER_THRI;
776 		local_irq_disable();
777 		amiga_custom.intena = IF_SETCLR | IF_TBE;
778 		mb();
779 		/* set a pending Tx Interrupt, transmitter should restart now */
780 		amiga_custom.intreq = IF_SETCLR | IF_TBE;
781 		mb();
782 		local_irq_restore(flags);
783 	}
784 	return ret;
785 }
786 
787 static unsigned int rs_write_room(struct tty_struct *tty)
788 {
789 	struct serial_state *info = tty->driver_data;
790 
791 	return CIRC_SPACE(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
792 }
793 
794 static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
795 {
796 	struct serial_state *info = tty->driver_data;
797 
798 	return CIRC_CNT(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
799 }
800 
801 static void rs_flush_buffer(struct tty_struct *tty)
802 {
803 	struct serial_state *info = tty->driver_data;
804 	unsigned long flags;
805 
806 	local_irq_save(flags);
807 	info->xmit.head = info->xmit.tail = 0;
808 	local_irq_restore(flags);
809 	tty_wakeup(tty);
810 }
811 
812 /*
813  * This function is used to send a high-priority XON/XOFF character to
814  * the device
815  */
816 static void rs_send_xchar(struct tty_struct *tty, char ch)
817 {
818 	struct serial_state *info = tty->driver_data;
819         unsigned long flags;
820 
821 	info->x_char = ch;
822 	if (ch) {
823 		/* Make sure transmit interrupts are on */
824 
825 	        /* Check this ! */
826 	        local_irq_save(flags);
827 		if(!(amiga_custom.intenar & IF_TBE)) {
828 		    amiga_custom.intena = IF_SETCLR | IF_TBE;
829 		    mb();
830 		    /* set a pending Tx Interrupt, transmitter should restart now */
831 		    amiga_custom.intreq = IF_SETCLR | IF_TBE;
832 		    mb();
833 		}
834 		local_irq_restore(flags);
835 
836 		info->IER |= UART_IER_THRI;
837 	}
838 }
839 
840 /*
841  * ------------------------------------------------------------
842  * rs_throttle()
843  *
844  * This routine is called by the upper-layer tty layer to signal that
845  * incoming characters should be throttled.
846  * ------------------------------------------------------------
847  */
848 static void rs_throttle(struct tty_struct * tty)
849 {
850 	struct serial_state *info = tty->driver_data;
851 	unsigned long flags;
852 #ifdef SERIAL_DEBUG_THROTTLE
853 	printk("throttle %s ....\n", tty_name(tty));
854 #endif
855 
856 	if (I_IXOFF(tty))
857 		rs_send_xchar(tty, STOP_CHAR(tty));
858 
859 	if (C_CRTSCTS(tty))
860 		info->MCR &= ~SER_RTS;
861 
862 	local_irq_save(flags);
863 	rtsdtr_ctrl(info->MCR);
864 	local_irq_restore(flags);
865 }
866 
867 static void rs_unthrottle(struct tty_struct * tty)
868 {
869 	struct serial_state *info = tty->driver_data;
870 	unsigned long flags;
871 #ifdef SERIAL_DEBUG_THROTTLE
872 	printk("unthrottle %s ....\n", tty_name(tty));
873 #endif
874 
875 	if (I_IXOFF(tty)) {
876 		if (info->x_char)
877 			info->x_char = 0;
878 		else
879 			rs_send_xchar(tty, START_CHAR(tty));
880 	}
881 	if (C_CRTSCTS(tty))
882 		info->MCR |= SER_RTS;
883 	local_irq_save(flags);
884 	rtsdtr_ctrl(info->MCR);
885 	local_irq_restore(flags);
886 }
887 
888 /*
889  * ------------------------------------------------------------
890  * rs_ioctl() and friends
891  * ------------------------------------------------------------
892  */
893 
894 static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
895 {
896 	struct serial_state *state = tty->driver_data;
897 	unsigned int close_delay, closing_wait;
898 
899 	tty_lock(tty);
900 	close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
901 	closing_wait = state->tport.closing_wait;
902 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
903 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
904 
905 	ss->line = tty->index;
906 	ss->port = state->port;
907 	ss->flags = state->tport.flags;
908 	ss->xmit_fifo_size = XMIT_FIFO_SIZE;
909 	ss->baud_base = state->baud_base;
910 	ss->close_delay = close_delay;
911 	ss->closing_wait = closing_wait;
912 	ss->custom_divisor = state->custom_divisor;
913 	tty_unlock(tty);
914 	return 0;
915 }
916 
917 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
918 {
919 	struct serial_state *state = tty->driver_data;
920 	struct tty_port *port = &state->tport;
921 	bool change_spd;
922 	int 			retval = 0;
923 	unsigned int close_delay, closing_wait;
924 
925 	tty_lock(tty);
926 	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
927 		ss->custom_divisor != state->custom_divisor;
928 	if (ss->irq || ss->port != state->port ||
929 			ss->xmit_fifo_size != XMIT_FIFO_SIZE) {
930 		tty_unlock(tty);
931 		return -EINVAL;
932 	}
933 
934 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
935 	closing_wait = ss->closing_wait;
936 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
937 		closing_wait = msecs_to_jiffies(closing_wait * 10);
938 
939 	if (!capable(CAP_SYS_ADMIN)) {
940 		if ((ss->baud_base != state->baud_base) ||
941 		    (close_delay != port->close_delay) ||
942 		    (closing_wait != port->closing_wait) ||
943 		    ((ss->flags & ~ASYNC_USR_MASK) !=
944 		     (port->flags & ~ASYNC_USR_MASK))) {
945 			tty_unlock(tty);
946 			return -EPERM;
947 		}
948 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
949 			       (ss->flags & ASYNC_USR_MASK));
950 		state->custom_divisor = ss->custom_divisor;
951 		goto check_and_exit;
952 	}
953 
954 	if (ss->baud_base < 9600) {
955 		tty_unlock(tty);
956 		return -EINVAL;
957 	}
958 
959 	/*
960 	 * OK, past this point, all the error checking has been done.
961 	 * At this point, we start making changes.....
962 	 */
963 
964 	state->baud_base = ss->baud_base;
965 	port->flags = ((port->flags & ~ASYNC_FLAGS) |
966 			(ss->flags & ASYNC_FLAGS));
967 	state->custom_divisor = ss->custom_divisor;
968 	port->close_delay = close_delay;
969 	port->closing_wait = closing_wait;
970 
971 check_and_exit:
972 	if (tty_port_initialized(port)) {
973 		if (change_spd) {
974 			/* warn about deprecation unless clearing */
975 			if (ss->flags & ASYNC_SPD_MASK)
976 				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
977 			change_speed(tty, state, NULL);
978 		}
979 	} else
980 		retval = startup(tty, state);
981 	tty_unlock(tty);
982 	return retval;
983 }
984 
985 /*
986  * get_lsr_info - get line status register info
987  *
988  * Purpose: Let user call ioctl() to get info when the UART physically
989  * 	    is emptied.  On bus types like RS485, the transmitter must
990  * 	    release the bus after transmitting. This must be done when
991  * 	    the transmit shift register is empty, not be done when the
992  * 	    transmit holding register is empty.  This functionality
993  * 	    allows an RS485 driver to be written in user space.
994  */
995 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
996 {
997 	unsigned char status;
998 	unsigned int result;
999 	unsigned long flags;
1000 
1001 	local_irq_save(flags);
1002 	status = amiga_custom.serdatr;
1003 	mb();
1004 	local_irq_restore(flags);
1005 	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1006 	if (copy_to_user(value, &result, sizeof(int)))
1007 		return -EFAULT;
1008 	return 0;
1009 }
1010 
1011 
1012 static int rs_tiocmget(struct tty_struct *tty)
1013 {
1014 	struct serial_state *info = tty->driver_data;
1015 	unsigned char control, status;
1016 	unsigned long flags;
1017 
1018 	if (tty_io_error(tty))
1019 		return -EIO;
1020 
1021 	control = info->MCR;
1022 	local_irq_save(flags);
1023 	status = ciab.pra;
1024 	local_irq_restore(flags);
1025 	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1026 		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1027 		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1028 		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1029 		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1030 }
1031 
1032 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1033 						unsigned int clear)
1034 {
1035 	struct serial_state *info = tty->driver_data;
1036 	unsigned long flags;
1037 
1038 	if (tty_io_error(tty))
1039 		return -EIO;
1040 
1041 	local_irq_save(flags);
1042 	if (set & TIOCM_RTS)
1043 		info->MCR |= SER_RTS;
1044 	if (set & TIOCM_DTR)
1045 		info->MCR |= SER_DTR;
1046 	if (clear & TIOCM_RTS)
1047 		info->MCR &= ~SER_RTS;
1048 	if (clear & TIOCM_DTR)
1049 		info->MCR &= ~SER_DTR;
1050 	rtsdtr_ctrl(info->MCR);
1051 	local_irq_restore(flags);
1052 	return 0;
1053 }
1054 
1055 /*
1056  * rs_break() --- routine which turns the break handling on or off
1057  */
1058 static int rs_break(struct tty_struct *tty, int break_state)
1059 {
1060 	unsigned long flags;
1061 
1062 	local_irq_save(flags);
1063 	if (break_state == -1)
1064 	  amiga_custom.adkcon = AC_SETCLR | AC_UARTBRK;
1065 	else
1066 	  amiga_custom.adkcon = AC_UARTBRK;
1067 	mb();
1068 	local_irq_restore(flags);
1069 	return 0;
1070 }
1071 
1072 /*
1073  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1074  * Return: write counters to the user passed counter struct
1075  * NB: both 1->0 and 0->1 transitions are counted except for
1076  *     RI where only 0->1 is counted.
1077  */
1078 static int rs_get_icount(struct tty_struct *tty,
1079 				struct serial_icounter_struct *icount)
1080 {
1081 	struct serial_state *info = tty->driver_data;
1082 	struct async_icount cnow;
1083 	unsigned long flags;
1084 
1085 	local_irq_save(flags);
1086 	cnow = info->icount;
1087 	local_irq_restore(flags);
1088 	icount->cts = cnow.cts;
1089 	icount->dsr = cnow.dsr;
1090 	icount->rng = cnow.rng;
1091 	icount->dcd = cnow.dcd;
1092 	icount->rx = cnow.rx;
1093 	icount->tx = cnow.tx;
1094 	icount->frame = cnow.frame;
1095 	icount->overrun = cnow.overrun;
1096 	icount->parity = cnow.parity;
1097 	icount->brk = cnow.brk;
1098 	icount->buf_overrun = cnow.buf_overrun;
1099 
1100 	return 0;
1101 }
1102 
1103 static int rs_ioctl(struct tty_struct *tty,
1104 		    unsigned int cmd, unsigned long arg)
1105 {
1106 	struct serial_state *info = tty->driver_data;
1107 	struct async_icount cprev, cnow;	/* kernel counter temps */
1108 	void __user *argp = (void __user *)arg;
1109 	unsigned long flags;
1110 	DEFINE_WAIT(wait);
1111 	int ret;
1112 
1113 	if ((cmd != TIOCSERCONFIG) &&
1114 	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1115 		if (tty_io_error(tty))
1116 		    return -EIO;
1117 	}
1118 
1119 	switch (cmd) {
1120 		case TIOCSERCONFIG:
1121 			return 0;
1122 
1123 		case TIOCSERGETLSR: /* Get line status register */
1124 			return get_lsr_info(info, argp);
1125 
1126 		/*
1127 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1128 		 * - mask passed in arg for lines of interest
1129  		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1130 		 * Caller should use TIOCGICOUNT to see which one it was
1131 		 */
1132 		case TIOCMIWAIT:
1133 			local_irq_save(flags);
1134 			/* note the counters on entry */
1135 			cprev = info->icount;
1136 			local_irq_restore(flags);
1137 			while (1) {
1138 				prepare_to_wait(&info->tport.delta_msr_wait,
1139 						&wait, TASK_INTERRUPTIBLE);
1140 				local_irq_save(flags);
1141 				cnow = info->icount; /* atomic copy */
1142 				local_irq_restore(flags);
1143 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1144 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
1145 					ret = -EIO; /* no change => error */
1146 					break;
1147 				}
1148 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1149 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1150 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1151 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1152 					ret = 0;
1153 					break;
1154 				}
1155 				schedule();
1156 				/* see if a signal did it */
1157 				if (signal_pending(current)) {
1158 					ret = -ERESTARTSYS;
1159 					break;
1160 				}
1161 				cprev = cnow;
1162 			}
1163 			finish_wait(&info->tport.delta_msr_wait, &wait);
1164 			return ret;
1165 
1166 		default:
1167 			return -ENOIOCTLCMD;
1168 		}
1169 	return 0;
1170 }
1171 
1172 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1173 {
1174 	struct serial_state *info = tty->driver_data;
1175 	unsigned long flags;
1176 	unsigned int cflag = tty->termios.c_cflag;
1177 
1178 	change_speed(tty, info, old_termios);
1179 
1180 	/* Handle transition to B0 status */
1181 	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
1182 		info->MCR &= ~(SER_DTR|SER_RTS);
1183 		local_irq_save(flags);
1184 		rtsdtr_ctrl(info->MCR);
1185 		local_irq_restore(flags);
1186 	}
1187 
1188 	/* Handle transition away from B0 status */
1189 	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1190 		info->MCR |= SER_DTR;
1191 		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
1192 			info->MCR |= SER_RTS;
1193 		local_irq_save(flags);
1194 		rtsdtr_ctrl(info->MCR);
1195 		local_irq_restore(flags);
1196 	}
1197 
1198 	/* Handle turning off CRTSCTS */
1199 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1200 		tty->hw_stopped = 0;
1201 		rs_start(tty);
1202 	}
1203 
1204 #if 0
1205 	/*
1206 	 * No need to wake up processes in open wait, since they
1207 	 * sample the CLOCAL flag once, and don't recheck it.
1208 	 * XXX  It's not clear whether the current behavior is correct
1209 	 * or not.  Hence, this may change.....
1210 	 */
1211 	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
1212 		wake_up_interruptible(&info->open_wait);
1213 #endif
1214 }
1215 
1216 /*
1217  * ------------------------------------------------------------
1218  * rs_close()
1219  *
1220  * This routine is called when the serial port gets closed.  First, we
1221  * wait for the last remaining data to be sent.  Then, we unlink its
1222  * async structure from the interrupt chain if necessary, and we free
1223  * that IRQ if nothing is left in the chain.
1224  * ------------------------------------------------------------
1225  */
1226 static void rs_close(struct tty_struct *tty, struct file * filp)
1227 {
1228 	struct serial_state *state = tty->driver_data;
1229 	struct tty_port *port = &state->tport;
1230 
1231 	if (tty_port_close_start(port, tty, filp) == 0)
1232 		return;
1233 
1234 	/*
1235 	 * At this point we stop accepting input.  To do this, we
1236 	 * disable the receive line status interrupts, and tell the
1237 	 * interrupt driver to stop checking the data ready bit in the
1238 	 * line status register.
1239 	 */
1240 	state->read_status_mask &= ~UART_LSR_DR;
1241 	if (tty_port_initialized(port)) {
1242 	        /* disable receive interrupts */
1243 	        amiga_custom.intena = IF_RBF;
1244 		mb();
1245 		/* clear any pending receive interrupt */
1246 		amiga_custom.intreq = IF_RBF;
1247 		mb();
1248 
1249 		/*
1250 		 * Before we drop DTR, make sure the UART transmitter
1251 		 * has completely drained; this is especially
1252 		 * important if there is a transmit FIFO!
1253 		 */
1254 		rs_wait_until_sent(tty, state->timeout);
1255 	}
1256 	shutdown(tty, state);
1257 	rs_flush_buffer(tty);
1258 
1259 	tty_ldisc_flush(tty);
1260 	port->tty = NULL;
1261 
1262 	tty_port_close_end(port, tty);
1263 }
1264 
1265 /*
1266  * rs_wait_until_sent() --- wait until the transmitter is empty
1267  */
1268 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1269 {
1270 	struct serial_state *info = tty->driver_data;
1271 	unsigned long orig_jiffies, char_time;
1272 	int lsr;
1273 
1274 	orig_jiffies = jiffies;
1275 
1276 	/*
1277 	 * Set the check interval to be 1/5 of the estimated time to
1278 	 * send a single character, and make it at least 1.  The check
1279 	 * interval should also be less than the timeout.
1280 	 *
1281 	 * Note: we have to use pretty tight timings here to satisfy
1282 	 * the NIST-PCTS.
1283 	 */
1284 	char_time = (info->timeout - HZ/50) / XMIT_FIFO_SIZE;
1285 	char_time = char_time / 5;
1286 	if (char_time == 0)
1287 		char_time = 1;
1288 	if (timeout)
1289 	  char_time = min_t(unsigned long, char_time, timeout);
1290 	/*
1291 	 * If the transmitter hasn't cleared in twice the approximate
1292 	 * amount of time to send the entire FIFO, it probably won't
1293 	 * ever clear.  This assumes the UART isn't doing flow
1294 	 * control, which is currently the case.  Hence, if it ever
1295 	 * takes longer than info->timeout, this is probably due to a
1296 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1297 	 * 2*info->timeout.
1298 	 */
1299 	if (!timeout || timeout > 2*info->timeout)
1300 		timeout = 2*info->timeout;
1301 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1302 	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1303 	printk("jiff=%lu...", jiffies);
1304 #endif
1305 	while(!((lsr = amiga_custom.serdatr) & SDR_TSRE)) {
1306 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1307 		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1308 #endif
1309 		msleep_interruptible(jiffies_to_msecs(char_time));
1310 		if (signal_pending(current))
1311 			break;
1312 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1313 			break;
1314 	}
1315 	__set_current_state(TASK_RUNNING);
1316 
1317 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1318 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1319 #endif
1320 }
1321 
1322 /*
1323  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1324  */
1325 static void rs_hangup(struct tty_struct *tty)
1326 {
1327 	struct serial_state *info = tty->driver_data;
1328 
1329 	rs_flush_buffer(tty);
1330 	shutdown(tty, info);
1331 	info->tport.count = 0;
1332 	tty_port_set_active(&info->tport, 0);
1333 	info->tport.tty = NULL;
1334 	wake_up_interruptible(&info->tport.open_wait);
1335 }
1336 
1337 /*
1338  * This routine is called whenever a serial port is opened.  It
1339  * enables interrupts for a serial port, linking in its async structure into
1340  * the IRQ chain.   It also performs the serial-specific
1341  * initialization for the tty structure.
1342  */
1343 static int rs_open(struct tty_struct *tty, struct file * filp)
1344 {
1345 	struct tty_port *port = tty->port;
1346 	struct serial_state *info = container_of(port, struct serial_state,
1347 			tport);
1348 	int retval;
1349 
1350 	port->count++;
1351 	port->tty = tty;
1352 	tty->driver_data = info;
1353 
1354 	retval = startup(tty, info);
1355 	if (retval) {
1356 		return retval;
1357 	}
1358 
1359 	return tty_port_block_til_ready(port, tty, filp);
1360 }
1361 
1362 /*
1363  * /proc fs routines....
1364  */
1365 
1366 static inline void line_info(struct seq_file *m, int line,
1367 		struct serial_state *state)
1368 {
1369 	char	stat_buf[30], control, status;
1370 	unsigned long flags;
1371 
1372 	seq_printf(m, "%d: uart:amiga_builtin", line);
1373 
1374 	local_irq_save(flags);
1375 	status = ciab.pra;
1376 	control = tty_port_initialized(&state->tport) ? state->MCR : status;
1377 	local_irq_restore(flags);
1378 
1379 	stat_buf[0] = 0;
1380 	stat_buf[1] = 0;
1381 	if(!(control & SER_RTS))
1382 		strcat(stat_buf, "|RTS");
1383 	if(!(status & SER_CTS))
1384 		strcat(stat_buf, "|CTS");
1385 	if(!(control & SER_DTR))
1386 		strcat(stat_buf, "|DTR");
1387 	if(!(status & SER_DSR))
1388 		strcat(stat_buf, "|DSR");
1389 	if(!(status & SER_DCD))
1390 		strcat(stat_buf, "|CD");
1391 
1392 	if (state->quot)
1393 		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1394 
1395 	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1396 
1397 	if (state->icount.frame)
1398 		seq_printf(m, " fe:%d", state->icount.frame);
1399 
1400 	if (state->icount.parity)
1401 		seq_printf(m, " pe:%d", state->icount.parity);
1402 
1403 	if (state->icount.brk)
1404 		seq_printf(m, " brk:%d", state->icount.brk);
1405 
1406 	if (state->icount.overrun)
1407 		seq_printf(m, " oe:%d", state->icount.overrun);
1408 
1409 	/*
1410 	 * Last thing is the RS-232 status lines
1411 	 */
1412 	seq_printf(m, " %s\n", stat_buf+1);
1413 }
1414 
1415 static int rs_proc_show(struct seq_file *m, void *v)
1416 {
1417 	seq_printf(m, "serinfo:1.0 driver:4.30\n");
1418 	line_info(m, 0, &serial_state);
1419 	return 0;
1420 }
1421 
1422 /*
1423  * ---------------------------------------------------------------------
1424  * rs_init() and friends
1425  *
1426  * rs_init() is called at boot-time to initialize the serial driver.
1427  * ---------------------------------------------------------------------
1428  */
1429 
1430 static const struct tty_operations serial_ops = {
1431 	.open = rs_open,
1432 	.close = rs_close,
1433 	.write = rs_write,
1434 	.put_char = rs_put_char,
1435 	.flush_chars = rs_flush_chars,
1436 	.write_room = rs_write_room,
1437 	.chars_in_buffer = rs_chars_in_buffer,
1438 	.flush_buffer = rs_flush_buffer,
1439 	.ioctl = rs_ioctl,
1440 	.throttle = rs_throttle,
1441 	.unthrottle = rs_unthrottle,
1442 	.set_termios = rs_set_termios,
1443 	.stop = rs_stop,
1444 	.start = rs_start,
1445 	.hangup = rs_hangup,
1446 	.break_ctl = rs_break,
1447 	.send_xchar = rs_send_xchar,
1448 	.wait_until_sent = rs_wait_until_sent,
1449 	.tiocmget = rs_tiocmget,
1450 	.tiocmset = rs_tiocmset,
1451 	.get_icount = rs_get_icount,
1452 	.set_serial = set_serial_info,
1453 	.get_serial = get_serial_info,
1454 	.proc_show = rs_proc_show,
1455 };
1456 
1457 static int amiga_carrier_raised(struct tty_port *port)
1458 {
1459 	return !(ciab.pra & SER_DCD);
1460 }
1461 
1462 static void amiga_dtr_rts(struct tty_port *port, int raise)
1463 {
1464 	struct serial_state *info = container_of(port, struct serial_state,
1465 			tport);
1466 	unsigned long flags;
1467 
1468 	if (raise)
1469 		info->MCR |= SER_DTR|SER_RTS;
1470 	else
1471 		info->MCR &= ~(SER_DTR|SER_RTS);
1472 
1473 	local_irq_save(flags);
1474 	rtsdtr_ctrl(info->MCR);
1475 	local_irq_restore(flags);
1476 }
1477 
1478 static const struct tty_port_operations amiga_port_ops = {
1479 	.carrier_raised = amiga_carrier_raised,
1480 	.dtr_rts = amiga_dtr_rts,
1481 };
1482 
1483 /*
1484  * The serial driver boot-time initialization code!
1485  */
1486 static int __init amiga_serial_probe(struct platform_device *pdev)
1487 {
1488 	struct serial_state *state = &serial_state;
1489 	struct tty_driver *driver;
1490 	unsigned long flags;
1491 	int error;
1492 
1493 	driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
1494 	if (IS_ERR(driver))
1495 		return PTR_ERR(driver);
1496 
1497 	/* Initialize the tty_driver structure */
1498 
1499 	driver->driver_name = "amiserial";
1500 	driver->name = "ttyS";
1501 	driver->major = TTY_MAJOR;
1502 	driver->minor_start = 64;
1503 	driver->type = TTY_DRIVER_TYPE_SERIAL;
1504 	driver->subtype = SERIAL_TYPE_NORMAL;
1505 	driver->init_termios = tty_std_termios;
1506 	driver->init_termios.c_cflag =
1507 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1508 	tty_set_operations(driver, &serial_ops);
1509 
1510 	memset(state, 0, sizeof(*state));
1511 	state->port = (int)&amiga_custom.serdatr; /* Just to give it a value */
1512 	tty_port_init(&state->tport);
1513 	state->tport.ops = &amiga_port_ops;
1514 	tty_port_link_device(&state->tport, driver, 0);
1515 
1516 	error = tty_register_driver(driver);
1517 	if (error)
1518 		goto fail_tty_driver_kref_put;
1519 
1520 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1521 
1522 	/* Hardware set up */
1523 
1524 	state->baud_base = amiga_colorclock;
1525 
1526 	/* set ISRs, and then disable the rx interrupts */
1527 	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1528 	if (error)
1529 		goto fail_unregister;
1530 
1531 	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1532 			    "serial RX", state);
1533 	if (error)
1534 		goto fail_free_irq;
1535 
1536 	local_irq_save(flags);
1537 
1538 	/* turn off Rx and Tx interrupts */
1539 	amiga_custom.intena = IF_RBF | IF_TBE;
1540 	mb();
1541 
1542 	/* clear any pending interrupt */
1543 	amiga_custom.intreq = IF_RBF | IF_TBE;
1544 	mb();
1545 
1546 	local_irq_restore(flags);
1547 
1548 	/*
1549 	 * set the appropriate directions for the modem control flags,
1550 	 * and clear RTS and DTR
1551 	 */
1552 	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1553 	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1554 
1555 	platform_set_drvdata(pdev, state);
1556 
1557 	serial_driver = driver;
1558 
1559 	return 0;
1560 
1561 fail_free_irq:
1562 	free_irq(IRQ_AMIGA_TBE, state);
1563 fail_unregister:
1564 	tty_unregister_driver(driver);
1565 fail_tty_driver_kref_put:
1566 	tty_port_destroy(&state->tport);
1567 	tty_driver_kref_put(driver);
1568 	return error;
1569 }
1570 
1571 static int __exit amiga_serial_remove(struct platform_device *pdev)
1572 {
1573 	struct serial_state *state = platform_get_drvdata(pdev);
1574 
1575 	tty_unregister_driver(serial_driver);
1576 	tty_driver_kref_put(serial_driver);
1577 	tty_port_destroy(&state->tport);
1578 
1579 	free_irq(IRQ_AMIGA_TBE, state);
1580 	free_irq(IRQ_AMIGA_RBF, state);
1581 
1582 	return 0;
1583 }
1584 
1585 static struct platform_driver amiga_serial_driver = {
1586 	.remove = __exit_p(amiga_serial_remove),
1587 	.driver   = {
1588 		.name	= "amiga-serial",
1589 	},
1590 };
1591 
1592 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1593 
1594 
1595 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1596 
1597 /*
1598  * ------------------------------------------------------------
1599  * Serial console driver
1600  * ------------------------------------------------------------
1601  */
1602 
1603 static void amiga_serial_putc(char c)
1604 {
1605 	amiga_custom.serdat = (unsigned char)c | 0x100;
1606 	while (!(amiga_custom.serdatr & 0x2000))
1607 		barrier();
1608 }
1609 
1610 /*
1611  *	Print a string to the serial port trying not to disturb
1612  *	any possible real use of the port...
1613  *
1614  *	The console must be locked when we get here.
1615  */
1616 static void serial_console_write(struct console *co, const char *s,
1617 				unsigned count)
1618 {
1619 	unsigned short intena = amiga_custom.intenar;
1620 
1621 	amiga_custom.intena = IF_TBE;
1622 
1623 	while (count--) {
1624 		if (*s == '\n')
1625 			amiga_serial_putc('\r');
1626 		amiga_serial_putc(*s++);
1627 	}
1628 
1629 	amiga_custom.intena = IF_SETCLR | (intena & IF_TBE);
1630 }
1631 
1632 static struct tty_driver *serial_console_device(struct console *c, int *index)
1633 {
1634 	*index = 0;
1635 	return serial_driver;
1636 }
1637 
1638 static struct console sercons = {
1639 	.name =		"ttyS",
1640 	.write =	serial_console_write,
1641 	.device =	serial_console_device,
1642 	.flags =	CON_PRINTBUFFER,
1643 	.index =	-1,
1644 };
1645 
1646 /*
1647  *	Register console.
1648  */
1649 static int __init amiserial_console_init(void)
1650 {
1651 	if (!MACH_IS_AMIGA)
1652 		return -ENODEV;
1653 
1654 	register_console(&sercons);
1655 	return 0;
1656 }
1657 console_initcall(amiserial_console_init);
1658 
1659 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1660 
1661 MODULE_LICENSE("GPL");
1662 MODULE_ALIAS("platform:amiga-serial");
1663