xref: /linux/drivers/tty/amiserial.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
1 /*
2  * Serial driver for the amiga builtin port.
3  *
4  * This code was created by taking serial.c version 4.30 from kernel
5  * release 2.3.22, replacing all hardware related stuff with the
6  * corresponding amiga hardware actions, and removing all irrelevant
7  * code. As a consequence, it uses many of the constants and names
8  * associated with the registers and bits of 16550 compatible UARTS -
9  * but only to keep track of status, etc in the state variables. It
10  * was done this was to make it easier to keep the code in line with
11  * (non hardware specific) changes to serial.c.
12  *
13  * The port is registered with the tty driver as minor device 64, and
14  * therefore other ports should should only use 65 upwards.
15  *
16  * Richard Lucock 28/12/99
17  *
18  *  Copyright (C) 1991, 1992  Linus Torvalds
19  *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
20  * 		1998, 1999  Theodore Ts'o
21  *
22  */
23 
24 /*
25  * Serial driver configuration section.  Here are the various options:
26  *
27  * SERIAL_PARANOIA_CHECK
28  * 		Check the magic number for the async_structure where
29  * 		ever possible.
30  */
31 
32 #include <linux/delay.h>
33 
34 #undef SERIAL_PARANOIA_CHECK
35 #define SERIAL_DO_RESTART
36 
37 /* Set of debugging defines */
38 
39 #undef SERIAL_DEBUG_INTR
40 #undef SERIAL_DEBUG_OPEN
41 #undef SERIAL_DEBUG_FLOW
42 #undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
43 
44 /* Sanity checks */
45 
46 #if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
47 #define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
48  tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
49 #else
50 #define DBG_CNT(s)
51 #endif
52 
53 /*
54  * End of serial driver configuration section.
55  */
56 
57 #include <linux/module.h>
58 
59 #include <linux/types.h>
60 #include <linux/serial.h>
61 #include <linux/serial_reg.h>
62 static char *serial_version = "4.30";
63 
64 #include <linux/errno.h>
65 #include <linux/signal.h>
66 #include <linux/sched.h>
67 #include <linux/kernel.h>
68 #include <linux/timer.h>
69 #include <linux/interrupt.h>
70 #include <linux/tty.h>
71 #include <linux/tty_flip.h>
72 #include <linux/circ_buf.h>
73 #include <linux/console.h>
74 #include <linux/major.h>
75 #include <linux/string.h>
76 #include <linux/fcntl.h>
77 #include <linux/ptrace.h>
78 #include <linux/ioport.h>
79 #include <linux/mm.h>
80 #include <linux/seq_file.h>
81 #include <linux/slab.h>
82 #include <linux/init.h>
83 #include <linux/bitops.h>
84 #include <linux/platform_device.h>
85 
86 #include <asm/setup.h>
87 
88 
89 #include <asm/irq.h>
90 
91 #include <asm/amigahw.h>
92 #include <asm/amigaints.h>
93 
94 struct serial_state {
95 	struct tty_port		tport;
96 	struct circ_buf		xmit;
97 	struct async_icount	icount;
98 
99 	unsigned long		port;
100 	int			baud_base;
101 	int			xmit_fifo_size;
102 	int			custom_divisor;
103 	int			read_status_mask;
104 	int			ignore_status_mask;
105 	int			timeout;
106 	int			quot;
107 	int			IER; 	/* Interrupt Enable Register */
108 	int			MCR; 	/* Modem control register */
109 	int			x_char;	/* xon/xoff character */
110 };
111 
112 #define custom amiga_custom
113 static char *serial_name = "Amiga-builtin serial driver";
114 
115 static struct tty_driver *serial_driver;
116 
117 /* number of characters left in xmit buffer before we ask for more */
118 #define WAKEUP_CHARS 256
119 
120 static unsigned char current_ctl_bits;
121 
122 static void change_speed(struct tty_struct *tty, struct serial_state *info,
123 		struct ktermios *old);
124 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
125 
126 
127 static struct serial_state rs_table[1];
128 
129 #define NR_PORTS ARRAY_SIZE(rs_table)
130 
131 #include <asm/uaccess.h>
132 
133 #define serial_isroot()	(capable(CAP_SYS_ADMIN))
134 
135 
136 static inline int serial_paranoia_check(struct serial_state *info,
137 					char *name, const char *routine)
138 {
139 #ifdef SERIAL_PARANOIA_CHECK
140 	static const char *badmagic =
141 		"Warning: bad magic number for serial struct (%s) in %s\n";
142 	static const char *badinfo =
143 		"Warning: null async_struct for (%s) in %s\n";
144 
145 	if (!info) {
146 		printk(badinfo, name, routine);
147 		return 1;
148 	}
149 	if (info->magic != SERIAL_MAGIC) {
150 		printk(badmagic, name, routine);
151 		return 1;
152 	}
153 #endif
154 	return 0;
155 }
156 
157 /* some serial hardware definitions */
158 #define SDR_OVRUN   (1<<15)
159 #define SDR_RBF     (1<<14)
160 #define SDR_TBE     (1<<13)
161 #define SDR_TSRE    (1<<12)
162 
163 #define SERPER_PARENB    (1<<15)
164 
165 #define AC_SETCLR   (1<<15)
166 #define AC_UARTBRK  (1<<11)
167 
168 #define SER_DTR     (1<<7)
169 #define SER_RTS     (1<<6)
170 #define SER_DCD     (1<<5)
171 #define SER_CTS     (1<<4)
172 #define SER_DSR     (1<<3)
173 
174 static __inline__ void rtsdtr_ctrl(int bits)
175 {
176     ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
177 }
178 
179 /*
180  * ------------------------------------------------------------
181  * rs_stop() and rs_start()
182  *
183  * This routines are called before setting or resetting tty->stopped.
184  * They enable or disable transmitter interrupts, as necessary.
185  * ------------------------------------------------------------
186  */
187 static void rs_stop(struct tty_struct *tty)
188 {
189 	struct serial_state *info = tty->driver_data;
190 	unsigned long flags;
191 
192 	if (serial_paranoia_check(info, tty->name, "rs_stop"))
193 		return;
194 
195 	local_irq_save(flags);
196 	if (info->IER & UART_IER_THRI) {
197 		info->IER &= ~UART_IER_THRI;
198 		/* disable Tx interrupt and remove any pending interrupts */
199 		custom.intena = IF_TBE;
200 		mb();
201 		custom.intreq = IF_TBE;
202 		mb();
203 	}
204 	local_irq_restore(flags);
205 }
206 
207 static void rs_start(struct tty_struct *tty)
208 {
209 	struct serial_state *info = tty->driver_data;
210 	unsigned long flags;
211 
212 	if (serial_paranoia_check(info, tty->name, "rs_start"))
213 		return;
214 
215 	local_irq_save(flags);
216 	if (info->xmit.head != info->xmit.tail
217 	    && info->xmit.buf
218 	    && !(info->IER & UART_IER_THRI)) {
219 		info->IER |= UART_IER_THRI;
220 		custom.intena = IF_SETCLR | IF_TBE;
221 		mb();
222 		/* set a pending Tx Interrupt, transmitter should restart now */
223 		custom.intreq = IF_SETCLR | IF_TBE;
224 		mb();
225 	}
226 	local_irq_restore(flags);
227 }
228 
229 /*
230  * ----------------------------------------------------------------------
231  *
232  * Here starts the interrupt handling routines.  All of the following
233  * subroutines are declared as inline and are folded into
234  * rs_interrupt().  They were separated out for readability's sake.
235  *
236  * Note: rs_interrupt() is a "fast" interrupt, which means that it
237  * runs with interrupts turned off.  People who may want to modify
238  * rs_interrupt() should try to keep the interrupt handler as fast as
239  * possible.  After you are done making modifications, it is not a bad
240  * idea to do:
241  *
242  * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
243  *
244  * and look at the resulting assemble code in serial.s.
245  *
246  * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
247  * -----------------------------------------------------------------------
248  */
249 
250 static void receive_chars(struct serial_state *info)
251 {
252         int status;
253 	int serdatr;
254 	unsigned char ch, flag;
255 	struct	async_icount *icount;
256 	int oe = 0;
257 
258 	icount = &info->icount;
259 
260 	status = UART_LSR_DR; /* We obviously have a character! */
261 	serdatr = custom.serdatr;
262 	mb();
263 	custom.intreq = IF_RBF;
264 	mb();
265 
266 	if((serdatr & 0x1ff) == 0)
267 	    status |= UART_LSR_BI;
268 	if(serdatr & SDR_OVRUN)
269 	    status |= UART_LSR_OE;
270 
271 	ch = serdatr & 0xff;
272 	icount->rx++;
273 
274 #ifdef SERIAL_DEBUG_INTR
275 	printk("DR%02x:%02x...", ch, status);
276 #endif
277 	flag = TTY_NORMAL;
278 
279 	/*
280 	 * We don't handle parity or frame errors - but I have left
281 	 * the code in, since I'm not sure that the errors can't be
282 	 * detected.
283 	 */
284 
285 	if (status & (UART_LSR_BI | UART_LSR_PE |
286 		      UART_LSR_FE | UART_LSR_OE)) {
287 	  /*
288 	   * For statistics only
289 	   */
290 	  if (status & UART_LSR_BI) {
291 	    status &= ~(UART_LSR_FE | UART_LSR_PE);
292 	    icount->brk++;
293 	  } else if (status & UART_LSR_PE)
294 	    icount->parity++;
295 	  else if (status & UART_LSR_FE)
296 	    icount->frame++;
297 	  if (status & UART_LSR_OE)
298 	    icount->overrun++;
299 
300 	  /*
301 	   * Now check to see if character should be
302 	   * ignored, and mask off conditions which
303 	   * should be ignored.
304 	   */
305 	  if (status & info->ignore_status_mask)
306 	    goto out;
307 
308 	  status &= info->read_status_mask;
309 
310 	  if (status & (UART_LSR_BI)) {
311 #ifdef SERIAL_DEBUG_INTR
312 	    printk("handling break....");
313 #endif
314 	    flag = TTY_BREAK;
315 	    if (info->tport.flags & ASYNC_SAK)
316 	      do_SAK(info->tport.tty);
317 	  } else if (status & UART_LSR_PE)
318 	    flag = TTY_PARITY;
319 	  else if (status & UART_LSR_FE)
320 	    flag = TTY_FRAME;
321 	  if (status & UART_LSR_OE) {
322 	    /*
323 	     * Overrun is special, since it's
324 	     * reported immediately, and doesn't
325 	     * affect the current character
326 	     */
327 	     oe = 1;
328 	  }
329 	}
330 	tty_insert_flip_char(&info->tport, ch, flag);
331 	if (oe == 1)
332 		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
333 	tty_flip_buffer_push(&info->tport);
334 out:
335 	return;
336 }
337 
338 static void transmit_chars(struct serial_state *info)
339 {
340 	custom.intreq = IF_TBE;
341 	mb();
342 	if (info->x_char) {
343 	        custom.serdat = info->x_char | 0x100;
344 		mb();
345 		info->icount.tx++;
346 		info->x_char = 0;
347 		return;
348 	}
349 	if (info->xmit.head == info->xmit.tail
350 	    || info->tport.tty->stopped
351 	    || info->tport.tty->hw_stopped) {
352 		info->IER &= ~UART_IER_THRI;
353 	        custom.intena = IF_TBE;
354 		mb();
355 		return;
356 	}
357 
358 	custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
359 	mb();
360 	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
361 	info->icount.tx++;
362 
363 	if (CIRC_CNT(info->xmit.head,
364 		     info->xmit.tail,
365 		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
366 		tty_wakeup(info->tport.tty);
367 
368 #ifdef SERIAL_DEBUG_INTR
369 	printk("THRE...");
370 #endif
371 	if (info->xmit.head == info->xmit.tail) {
372 	        custom.intena = IF_TBE;
373 		mb();
374 		info->IER &= ~UART_IER_THRI;
375 	}
376 }
377 
378 static void check_modem_status(struct serial_state *info)
379 {
380 	struct tty_port *port = &info->tport;
381 	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
382 	unsigned char dstatus;
383 	struct	async_icount *icount;
384 
385 	/* Determine bits that have changed */
386 	dstatus = status ^ current_ctl_bits;
387 	current_ctl_bits = status;
388 
389 	if (dstatus) {
390 		icount = &info->icount;
391 		/* update input line counters */
392 		if (dstatus & SER_DSR)
393 			icount->dsr++;
394 		if (dstatus & SER_DCD) {
395 			icount->dcd++;
396 		}
397 		if (dstatus & SER_CTS)
398 			icount->cts++;
399 		wake_up_interruptible(&port->delta_msr_wait);
400 	}
401 
402 	if ((port->flags & ASYNC_CHECK_CD) && (dstatus & SER_DCD)) {
403 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
404 		printk("ttyS%d CD now %s...", info->line,
405 		       (!(status & SER_DCD)) ? "on" : "off");
406 #endif
407 		if (!(status & SER_DCD))
408 			wake_up_interruptible(&port->open_wait);
409 		else {
410 #ifdef SERIAL_DEBUG_OPEN
411 			printk("doing serial hangup...");
412 #endif
413 			if (port->tty)
414 				tty_hangup(port->tty);
415 		}
416 	}
417 	if (tty_port_cts_enabled(port)) {
418 		if (port->tty->hw_stopped) {
419 			if (!(status & SER_CTS)) {
420 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
421 				printk("CTS tx start...");
422 #endif
423 				port->tty->hw_stopped = 0;
424 				info->IER |= UART_IER_THRI;
425 				custom.intena = IF_SETCLR | IF_TBE;
426 				mb();
427 				/* set a pending Tx Interrupt, transmitter should restart now */
428 				custom.intreq = IF_SETCLR | IF_TBE;
429 				mb();
430 				tty_wakeup(port->tty);
431 				return;
432 			}
433 		} else {
434 			if ((status & SER_CTS)) {
435 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
436 				printk("CTS tx stop...");
437 #endif
438 				port->tty->hw_stopped = 1;
439 				info->IER &= ~UART_IER_THRI;
440 				/* disable Tx interrupt and remove any pending interrupts */
441 				custom.intena = IF_TBE;
442 				mb();
443 				custom.intreq = IF_TBE;
444 				mb();
445 			}
446 		}
447 	}
448 }
449 
450 static irqreturn_t ser_vbl_int( int irq, void *data)
451 {
452         /* vbl is just a periodic interrupt we tie into to update modem status */
453 	struct serial_state *info = data;
454 	/*
455 	 * TBD - is it better to unregister from this interrupt or to
456 	 * ignore it if MSI is clear ?
457 	 */
458 	if(info->IER & UART_IER_MSI)
459 	  check_modem_status(info);
460 	return IRQ_HANDLED;
461 }
462 
463 static irqreturn_t ser_rx_int(int irq, void *dev_id)
464 {
465 	struct serial_state *info = dev_id;
466 
467 #ifdef SERIAL_DEBUG_INTR
468 	printk("ser_rx_int...");
469 #endif
470 
471 	if (!info->tport.tty)
472 		return IRQ_NONE;
473 
474 	receive_chars(info);
475 #ifdef SERIAL_DEBUG_INTR
476 	printk("end.\n");
477 #endif
478 	return IRQ_HANDLED;
479 }
480 
481 static irqreturn_t ser_tx_int(int irq, void *dev_id)
482 {
483 	struct serial_state *info = dev_id;
484 
485 	if (custom.serdatr & SDR_TBE) {
486 #ifdef SERIAL_DEBUG_INTR
487 	  printk("ser_tx_int...");
488 #endif
489 
490 	  if (!info->tport.tty)
491 		return IRQ_NONE;
492 
493 	  transmit_chars(info);
494 #ifdef SERIAL_DEBUG_INTR
495 	  printk("end.\n");
496 #endif
497 	}
498 	return IRQ_HANDLED;
499 }
500 
501 /*
502  * -------------------------------------------------------------------
503  * Here ends the serial interrupt routines.
504  * -------------------------------------------------------------------
505  */
506 
507 /*
508  * ---------------------------------------------------------------
509  * Low level utility subroutines for the serial driver:  routines to
510  * figure out the appropriate timeout for an interrupt chain, routines
511  * to initialize and startup a serial port, and routines to shutdown a
512  * serial port.  Useful stuff like that.
513  * ---------------------------------------------------------------
514  */
515 
516 static int startup(struct tty_struct *tty, struct serial_state *info)
517 {
518 	struct tty_port *port = &info->tport;
519 	unsigned long flags;
520 	int	retval=0;
521 	unsigned long page;
522 
523 	page = get_zeroed_page(GFP_KERNEL);
524 	if (!page)
525 		return -ENOMEM;
526 
527 	local_irq_save(flags);
528 
529 	if (port->flags & ASYNC_INITIALIZED) {
530 		free_page(page);
531 		goto errout;
532 	}
533 
534 	if (info->xmit.buf)
535 		free_page(page);
536 	else
537 		info->xmit.buf = (unsigned char *) page;
538 
539 #ifdef SERIAL_DEBUG_OPEN
540 	printk("starting up ttys%d ...", info->line);
541 #endif
542 
543 	/* Clear anything in the input buffer */
544 
545 	custom.intreq = IF_RBF;
546 	mb();
547 
548 	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
549 	if (retval) {
550 	  if (serial_isroot()) {
551 	      set_bit(TTY_IO_ERROR, &tty->flags);
552 	    retval = 0;
553 	  }
554 	  goto errout;
555 	}
556 
557 	/* enable both Rx and Tx interrupts */
558 	custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
559 	mb();
560 	info->IER = UART_IER_MSI;
561 
562 	/* remember current state of the DCD and CTS bits */
563 	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
564 
565 	info->MCR = 0;
566 	if (C_BAUD(tty))
567 	  info->MCR = SER_DTR | SER_RTS;
568 	rtsdtr_ctrl(info->MCR);
569 
570 	clear_bit(TTY_IO_ERROR, &tty->flags);
571 	info->xmit.head = info->xmit.tail = 0;
572 
573 	/*
574 	 * Set up the tty->alt_speed kludge
575 	 */
576 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
577 		tty->alt_speed = 57600;
578 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
579 		tty->alt_speed = 115200;
580 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
581 		tty->alt_speed = 230400;
582 	if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
583 		tty->alt_speed = 460800;
584 
585 	/*
586 	 * and set the speed of the serial port
587 	 */
588 	change_speed(tty, info, NULL);
589 
590 	port->flags |= ASYNC_INITIALIZED;
591 	local_irq_restore(flags);
592 	return 0;
593 
594 errout:
595 	local_irq_restore(flags);
596 	return retval;
597 }
598 
599 /*
600  * This routine will shutdown a serial port; interrupts are disabled, and
601  * DTR is dropped if the hangup on close termio flag is on.
602  */
603 static void shutdown(struct tty_struct *tty, struct serial_state *info)
604 {
605 	unsigned long	flags;
606 	struct serial_state *state;
607 
608 	if (!(info->tport.flags & ASYNC_INITIALIZED))
609 		return;
610 
611 	state = info;
612 
613 #ifdef SERIAL_DEBUG_OPEN
614 	printk("Shutting down serial port %d ....\n", info->line);
615 #endif
616 
617 	local_irq_save(flags); /* Disable interrupts */
618 
619 	/*
620 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
621 	 * here so the queue might never be waken up
622 	 */
623 	wake_up_interruptible(&info->tport.delta_msr_wait);
624 
625 	/*
626 	 * Free the IRQ, if necessary
627 	 */
628 	free_irq(IRQ_AMIGA_VERTB, info);
629 
630 	if (info->xmit.buf) {
631 		free_page((unsigned long) info->xmit.buf);
632 		info->xmit.buf = NULL;
633 	}
634 
635 	info->IER = 0;
636 	custom.intena = IF_RBF | IF_TBE;
637 	mb();
638 
639 	/* disable break condition */
640 	custom.adkcon = AC_UARTBRK;
641 	mb();
642 
643 	if (tty->termios.c_cflag & HUPCL)
644 		info->MCR &= ~(SER_DTR|SER_RTS);
645 	rtsdtr_ctrl(info->MCR);
646 
647 	set_bit(TTY_IO_ERROR, &tty->flags);
648 
649 	info->tport.flags &= ~ASYNC_INITIALIZED;
650 	local_irq_restore(flags);
651 }
652 
653 
654 /*
655  * This routine is called to set the UART divisor registers to match
656  * the specified baud rate for a serial port.
657  */
658 static void change_speed(struct tty_struct *tty, struct serial_state *info,
659 			 struct ktermios *old_termios)
660 {
661 	struct tty_port *port = &info->tport;
662 	int	quot = 0, baud_base, baud;
663 	unsigned cflag, cval = 0;
664 	int	bits;
665 	unsigned long	flags;
666 
667 	cflag = tty->termios.c_cflag;
668 
669 	/* Byte size is always 8 bits plus parity bit if requested */
670 
671 	cval = 3; bits = 10;
672 	if (cflag & CSTOPB) {
673 		cval |= 0x04;
674 		bits++;
675 	}
676 	if (cflag & PARENB) {
677 		cval |= UART_LCR_PARITY;
678 		bits++;
679 	}
680 	if (!(cflag & PARODD))
681 		cval |= UART_LCR_EPAR;
682 #ifdef CMSPAR
683 	if (cflag & CMSPAR)
684 		cval |= UART_LCR_SPAR;
685 #endif
686 
687 	/* Determine divisor based on baud rate */
688 	baud = tty_get_baud_rate(tty);
689 	if (!baud)
690 		baud = 9600;	/* B0 transition handled in rs_set_termios */
691 	baud_base = info->baud_base;
692 	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
693 		quot = info->custom_divisor;
694 	else {
695 		if (baud == 134)
696 			/* Special case since 134 is really 134.5 */
697 			quot = (2*baud_base / 269);
698 		else if (baud)
699 			quot = baud_base / baud;
700 	}
701 	/* If the quotient is zero refuse the change */
702 	if (!quot && old_termios) {
703 		/* FIXME: Will need updating for new tty in the end */
704 		tty->termios.c_cflag &= ~CBAUD;
705 		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
706 		baud = tty_get_baud_rate(tty);
707 		if (!baud)
708 			baud = 9600;
709 		if (baud == 38400 &&
710 		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
711 			quot = info->custom_divisor;
712 		else {
713 			if (baud == 134)
714 				/* Special case since 134 is really 134.5 */
715 				quot = (2*baud_base / 269);
716 			else if (baud)
717 				quot = baud_base / baud;
718 		}
719 	}
720 	/* As a last resort, if the quotient is zero, default to 9600 bps */
721 	if (!quot)
722 		quot = baud_base / 9600;
723 	info->quot = quot;
724 	info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
725 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
726 
727 	/* CTS flow control flag and modem status interrupts */
728 	info->IER &= ~UART_IER_MSI;
729 	if (port->flags & ASYNC_HARDPPS_CD)
730 		info->IER |= UART_IER_MSI;
731 	if (cflag & CRTSCTS) {
732 		port->flags |= ASYNC_CTS_FLOW;
733 		info->IER |= UART_IER_MSI;
734 	} else
735 		port->flags &= ~ASYNC_CTS_FLOW;
736 	if (cflag & CLOCAL)
737 		port->flags &= ~ASYNC_CHECK_CD;
738 	else {
739 		port->flags |= ASYNC_CHECK_CD;
740 		info->IER |= UART_IER_MSI;
741 	}
742 	/* TBD:
743 	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
744 	 */
745 
746 	/*
747 	 * Set up parity check flag
748 	 */
749 
750 	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
751 	if (I_INPCK(tty))
752 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
753 	if (I_BRKINT(tty) || I_PARMRK(tty))
754 		info->read_status_mask |= UART_LSR_BI;
755 
756 	/*
757 	 * Characters to ignore
758 	 */
759 	info->ignore_status_mask = 0;
760 	if (I_IGNPAR(tty))
761 		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
762 	if (I_IGNBRK(tty)) {
763 		info->ignore_status_mask |= UART_LSR_BI;
764 		/*
765 		 * If we're ignore parity and break indicators, ignore
766 		 * overruns too.  (For real raw support).
767 		 */
768 		if (I_IGNPAR(tty))
769 			info->ignore_status_mask |= UART_LSR_OE;
770 	}
771 	/*
772 	 * !!! ignore all characters if CREAD is not set
773 	 */
774 	if ((cflag & CREAD) == 0)
775 		info->ignore_status_mask |= UART_LSR_DR;
776 	local_irq_save(flags);
777 
778 	{
779 	  short serper;
780 
781 	/* Set up the baud rate */
782 	  serper = quot - 1;
783 
784 	/* Enable or disable parity bit */
785 
786 	if(cval & UART_LCR_PARITY)
787 	  serper |= (SERPER_PARENB);
788 
789 	custom.serper = serper;
790 	mb();
791 	}
792 
793 	local_irq_restore(flags);
794 }
795 
796 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
797 {
798 	struct serial_state *info;
799 	unsigned long flags;
800 
801 	info = tty->driver_data;
802 
803 	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
804 		return 0;
805 
806 	if (!info->xmit.buf)
807 		return 0;
808 
809 	local_irq_save(flags);
810 	if (CIRC_SPACE(info->xmit.head,
811 		       info->xmit.tail,
812 		       SERIAL_XMIT_SIZE) == 0) {
813 		local_irq_restore(flags);
814 		return 0;
815 	}
816 
817 	info->xmit.buf[info->xmit.head++] = ch;
818 	info->xmit.head &= SERIAL_XMIT_SIZE-1;
819 	local_irq_restore(flags);
820 	return 1;
821 }
822 
823 static void rs_flush_chars(struct tty_struct *tty)
824 {
825 	struct serial_state *info = tty->driver_data;
826 	unsigned long flags;
827 
828 	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
829 		return;
830 
831 	if (info->xmit.head == info->xmit.tail
832 	    || tty->stopped
833 	    || tty->hw_stopped
834 	    || !info->xmit.buf)
835 		return;
836 
837 	local_irq_save(flags);
838 	info->IER |= UART_IER_THRI;
839 	custom.intena = IF_SETCLR | IF_TBE;
840 	mb();
841 	/* set a pending Tx Interrupt, transmitter should restart now */
842 	custom.intreq = IF_SETCLR | IF_TBE;
843 	mb();
844 	local_irq_restore(flags);
845 }
846 
847 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
848 {
849 	int	c, ret = 0;
850 	struct serial_state *info = tty->driver_data;
851 	unsigned long flags;
852 
853 	if (serial_paranoia_check(info, tty->name, "rs_write"))
854 		return 0;
855 
856 	if (!info->xmit.buf)
857 		return 0;
858 
859 	local_irq_save(flags);
860 	while (1) {
861 		c = CIRC_SPACE_TO_END(info->xmit.head,
862 				      info->xmit.tail,
863 				      SERIAL_XMIT_SIZE);
864 		if (count < c)
865 			c = count;
866 		if (c <= 0) {
867 			break;
868 		}
869 		memcpy(info->xmit.buf + info->xmit.head, buf, c);
870 		info->xmit.head = ((info->xmit.head + c) &
871 				   (SERIAL_XMIT_SIZE-1));
872 		buf += c;
873 		count -= c;
874 		ret += c;
875 	}
876 	local_irq_restore(flags);
877 
878 	if (info->xmit.head != info->xmit.tail
879 	    && !tty->stopped
880 	    && !tty->hw_stopped
881 	    && !(info->IER & UART_IER_THRI)) {
882 		info->IER |= UART_IER_THRI;
883 		local_irq_disable();
884 		custom.intena = IF_SETCLR | IF_TBE;
885 		mb();
886 		/* set a pending Tx Interrupt, transmitter should restart now */
887 		custom.intreq = IF_SETCLR | IF_TBE;
888 		mb();
889 		local_irq_restore(flags);
890 	}
891 	return ret;
892 }
893 
894 static int rs_write_room(struct tty_struct *tty)
895 {
896 	struct serial_state *info = tty->driver_data;
897 
898 	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
899 		return 0;
900 	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
901 }
902 
903 static int rs_chars_in_buffer(struct tty_struct *tty)
904 {
905 	struct serial_state *info = tty->driver_data;
906 
907 	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
908 		return 0;
909 	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
910 }
911 
912 static void rs_flush_buffer(struct tty_struct *tty)
913 {
914 	struct serial_state *info = tty->driver_data;
915 	unsigned long flags;
916 
917 	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
918 		return;
919 	local_irq_save(flags);
920 	info->xmit.head = info->xmit.tail = 0;
921 	local_irq_restore(flags);
922 	tty_wakeup(tty);
923 }
924 
925 /*
926  * This function is used to send a high-priority XON/XOFF character to
927  * the device
928  */
929 static void rs_send_xchar(struct tty_struct *tty, char ch)
930 {
931 	struct serial_state *info = tty->driver_data;
932         unsigned long flags;
933 
934 	if (serial_paranoia_check(info, tty->name, "rs_send_char"))
935 		return;
936 
937 	info->x_char = ch;
938 	if (ch) {
939 		/* Make sure transmit interrupts are on */
940 
941 	        /* Check this ! */
942 	        local_irq_save(flags);
943 		if(!(custom.intenar & IF_TBE)) {
944 		    custom.intena = IF_SETCLR | IF_TBE;
945 		    mb();
946 		    /* set a pending Tx Interrupt, transmitter should restart now */
947 		    custom.intreq = IF_SETCLR | IF_TBE;
948 		    mb();
949 		}
950 		local_irq_restore(flags);
951 
952 		info->IER |= UART_IER_THRI;
953 	}
954 }
955 
956 /*
957  * ------------------------------------------------------------
958  * rs_throttle()
959  *
960  * This routine is called by the upper-layer tty layer to signal that
961  * incoming characters should be throttled.
962  * ------------------------------------------------------------
963  */
964 static void rs_throttle(struct tty_struct * tty)
965 {
966 	struct serial_state *info = tty->driver_data;
967 	unsigned long flags;
968 #ifdef SERIAL_DEBUG_THROTTLE
969 	char	buf[64];
970 
971 	printk("throttle %s: %d....\n", tty_name(tty, buf),
972 	       tty->ldisc.chars_in_buffer(tty));
973 #endif
974 
975 	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
976 		return;
977 
978 	if (I_IXOFF(tty))
979 		rs_send_xchar(tty, STOP_CHAR(tty));
980 
981 	if (tty->termios.c_cflag & CRTSCTS)
982 		info->MCR &= ~SER_RTS;
983 
984 	local_irq_save(flags);
985 	rtsdtr_ctrl(info->MCR);
986 	local_irq_restore(flags);
987 }
988 
989 static void rs_unthrottle(struct tty_struct * tty)
990 {
991 	struct serial_state *info = tty->driver_data;
992 	unsigned long flags;
993 #ifdef SERIAL_DEBUG_THROTTLE
994 	char	buf[64];
995 
996 	printk("unthrottle %s: %d....\n", tty_name(tty, buf),
997 	       tty->ldisc.chars_in_buffer(tty));
998 #endif
999 
1000 	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
1001 		return;
1002 
1003 	if (I_IXOFF(tty)) {
1004 		if (info->x_char)
1005 			info->x_char = 0;
1006 		else
1007 			rs_send_xchar(tty, START_CHAR(tty));
1008 	}
1009 	if (tty->termios.c_cflag & CRTSCTS)
1010 		info->MCR |= SER_RTS;
1011 	local_irq_save(flags);
1012 	rtsdtr_ctrl(info->MCR);
1013 	local_irq_restore(flags);
1014 }
1015 
1016 /*
1017  * ------------------------------------------------------------
1018  * rs_ioctl() and friends
1019  * ------------------------------------------------------------
1020  */
1021 
1022 static int get_serial_info(struct tty_struct *tty, struct serial_state *state,
1023 			   struct serial_struct __user * retinfo)
1024 {
1025 	struct serial_struct tmp;
1026 
1027 	if (!retinfo)
1028 		return -EFAULT;
1029 	memset(&tmp, 0, sizeof(tmp));
1030 	tty_lock(tty);
1031 	tmp.line = tty->index;
1032 	tmp.port = state->port;
1033 	tmp.flags = state->tport.flags;
1034 	tmp.xmit_fifo_size = state->xmit_fifo_size;
1035 	tmp.baud_base = state->baud_base;
1036 	tmp.close_delay = state->tport.close_delay;
1037 	tmp.closing_wait = state->tport.closing_wait;
1038 	tmp.custom_divisor = state->custom_divisor;
1039 	tty_unlock(tty);
1040 	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
1041 		return -EFAULT;
1042 	return 0;
1043 }
1044 
1045 static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
1046 			   struct serial_struct __user * new_info)
1047 {
1048 	struct tty_port *port = &state->tport;
1049 	struct serial_struct new_serial;
1050 	bool change_spd;
1051 	int 			retval = 0;
1052 
1053 	if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
1054 		return -EFAULT;
1055 
1056 	tty_lock(tty);
1057 	change_spd = ((new_serial.flags ^ port->flags) & ASYNC_SPD_MASK) ||
1058 		new_serial.custom_divisor != state->custom_divisor;
1059 	if (new_serial.irq || new_serial.port != state->port ||
1060 			new_serial.xmit_fifo_size != state->xmit_fifo_size) {
1061 		tty_unlock(tty);
1062 		return -EINVAL;
1063 	}
1064 
1065 	if (!serial_isroot()) {
1066 		if ((new_serial.baud_base != state->baud_base) ||
1067 		    (new_serial.close_delay != port->close_delay) ||
1068 		    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
1069 		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
1070 		     (port->flags & ~ASYNC_USR_MASK))) {
1071 			tty_unlock(tty);
1072 			return -EPERM;
1073 		}
1074 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
1075 			       (new_serial.flags & ASYNC_USR_MASK));
1076 		state->custom_divisor = new_serial.custom_divisor;
1077 		goto check_and_exit;
1078 	}
1079 
1080 	if (new_serial.baud_base < 9600) {
1081 		tty_unlock(tty);
1082 		return -EINVAL;
1083 	}
1084 
1085 	/*
1086 	 * OK, past this point, all the error checking has been done.
1087 	 * At this point, we start making changes.....
1088 	 */
1089 
1090 	state->baud_base = new_serial.baud_base;
1091 	port->flags = ((port->flags & ~ASYNC_FLAGS) |
1092 			(new_serial.flags & ASYNC_FLAGS));
1093 	state->custom_divisor = new_serial.custom_divisor;
1094 	port->close_delay = new_serial.close_delay * HZ/100;
1095 	port->closing_wait = new_serial.closing_wait * HZ/100;
1096 	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1097 
1098 check_and_exit:
1099 	if (port->flags & ASYNC_INITIALIZED) {
1100 		if (change_spd) {
1101 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
1102 				tty->alt_speed = 57600;
1103 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
1104 				tty->alt_speed = 115200;
1105 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
1106 				tty->alt_speed = 230400;
1107 			if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
1108 				tty->alt_speed = 460800;
1109 			change_speed(tty, state, NULL);
1110 		}
1111 	} else
1112 		retval = startup(tty, state);
1113 	tty_unlock(tty);
1114 	return retval;
1115 }
1116 
1117 
1118 /*
1119  * get_lsr_info - get line status register info
1120  *
1121  * Purpose: Let user call ioctl() to get info when the UART physically
1122  * 	    is emptied.  On bus types like RS485, the transmitter must
1123  * 	    release the bus after transmitting. This must be done when
1124  * 	    the transmit shift register is empty, not be done when the
1125  * 	    transmit holding register is empty.  This functionality
1126  * 	    allows an RS485 driver to be written in user space.
1127  */
1128 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
1129 {
1130 	unsigned char status;
1131 	unsigned int result;
1132 	unsigned long flags;
1133 
1134 	local_irq_save(flags);
1135 	status = custom.serdatr;
1136 	mb();
1137 	local_irq_restore(flags);
1138 	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1139 	if (copy_to_user(value, &result, sizeof(int)))
1140 		return -EFAULT;
1141 	return 0;
1142 }
1143 
1144 
1145 static int rs_tiocmget(struct tty_struct *tty)
1146 {
1147 	struct serial_state *info = tty->driver_data;
1148 	unsigned char control, status;
1149 	unsigned long flags;
1150 
1151 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1152 		return -ENODEV;
1153 	if (tty->flags & (1 << TTY_IO_ERROR))
1154 		return -EIO;
1155 
1156 	control = info->MCR;
1157 	local_irq_save(flags);
1158 	status = ciab.pra;
1159 	local_irq_restore(flags);
1160 	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1161 		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1162 		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1163 		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1164 		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1165 }
1166 
1167 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1168 						unsigned int clear)
1169 {
1170 	struct serial_state *info = tty->driver_data;
1171 	unsigned long flags;
1172 
1173 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1174 		return -ENODEV;
1175 	if (tty->flags & (1 << TTY_IO_ERROR))
1176 		return -EIO;
1177 
1178 	local_irq_save(flags);
1179 	if (set & TIOCM_RTS)
1180 		info->MCR |= SER_RTS;
1181 	if (set & TIOCM_DTR)
1182 		info->MCR |= SER_DTR;
1183 	if (clear & TIOCM_RTS)
1184 		info->MCR &= ~SER_RTS;
1185 	if (clear & TIOCM_DTR)
1186 		info->MCR &= ~SER_DTR;
1187 	rtsdtr_ctrl(info->MCR);
1188 	local_irq_restore(flags);
1189 	return 0;
1190 }
1191 
1192 /*
1193  * rs_break() --- routine which turns the break handling on or off
1194  */
1195 static int rs_break(struct tty_struct *tty, int break_state)
1196 {
1197 	struct serial_state *info = tty->driver_data;
1198 	unsigned long flags;
1199 
1200 	if (serial_paranoia_check(info, tty->name, "rs_break"))
1201 		return -EINVAL;
1202 
1203 	local_irq_save(flags);
1204 	if (break_state == -1)
1205 	  custom.adkcon = AC_SETCLR | AC_UARTBRK;
1206 	else
1207 	  custom.adkcon = AC_UARTBRK;
1208 	mb();
1209 	local_irq_restore(flags);
1210 	return 0;
1211 }
1212 
1213 /*
1214  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1215  * Return: write counters to the user passed counter struct
1216  * NB: both 1->0 and 0->1 transitions are counted except for
1217  *     RI where only 0->1 is counted.
1218  */
1219 static int rs_get_icount(struct tty_struct *tty,
1220 				struct serial_icounter_struct *icount)
1221 {
1222 	struct serial_state *info = tty->driver_data;
1223 	struct async_icount cnow;
1224 	unsigned long flags;
1225 
1226 	local_irq_save(flags);
1227 	cnow = info->icount;
1228 	local_irq_restore(flags);
1229 	icount->cts = cnow.cts;
1230 	icount->dsr = cnow.dsr;
1231 	icount->rng = cnow.rng;
1232 	icount->dcd = cnow.dcd;
1233 	icount->rx = cnow.rx;
1234 	icount->tx = cnow.tx;
1235 	icount->frame = cnow.frame;
1236 	icount->overrun = cnow.overrun;
1237 	icount->parity = cnow.parity;
1238 	icount->brk = cnow.brk;
1239 	icount->buf_overrun = cnow.buf_overrun;
1240 
1241 	return 0;
1242 }
1243 
1244 static int rs_ioctl(struct tty_struct *tty,
1245 		    unsigned int cmd, unsigned long arg)
1246 {
1247 	struct serial_state *info = tty->driver_data;
1248 	struct async_icount cprev, cnow;	/* kernel counter temps */
1249 	void __user *argp = (void __user *)arg;
1250 	unsigned long flags;
1251 
1252 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1253 		return -ENODEV;
1254 
1255 	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1256 	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
1257 	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1258 		if (tty->flags & (1 << TTY_IO_ERROR))
1259 		    return -EIO;
1260 	}
1261 
1262 	switch (cmd) {
1263 		case TIOCGSERIAL:
1264 			return get_serial_info(tty, info, argp);
1265 		case TIOCSSERIAL:
1266 			return set_serial_info(tty, info, argp);
1267 		case TIOCSERCONFIG:
1268 			return 0;
1269 
1270 		case TIOCSERGETLSR: /* Get line status register */
1271 			return get_lsr_info(info, argp);
1272 
1273 		case TIOCSERGSTRUCT:
1274 			if (copy_to_user(argp,
1275 					 info, sizeof(struct serial_state)))
1276 				return -EFAULT;
1277 			return 0;
1278 
1279 		/*
1280 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1281 		 * - mask passed in arg for lines of interest
1282  		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1283 		 * Caller should use TIOCGICOUNT to see which one it was
1284 		 */
1285 		case TIOCMIWAIT:
1286 			local_irq_save(flags);
1287 			/* note the counters on entry */
1288 			cprev = info->icount;
1289 			local_irq_restore(flags);
1290 			while (1) {
1291 				interruptible_sleep_on(&info->tport.delta_msr_wait);
1292 				/* see if a signal did it */
1293 				if (signal_pending(current))
1294 					return -ERESTARTSYS;
1295 				local_irq_save(flags);
1296 				cnow = info->icount; /* atomic copy */
1297 				local_irq_restore(flags);
1298 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1299 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
1300 					return -EIO; /* no change => error */
1301 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1302 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1303 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1304 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1305 					return 0;
1306 				}
1307 				cprev = cnow;
1308 			}
1309 			/* NOTREACHED */
1310 
1311 		case TIOCSERGWILD:
1312 		case TIOCSERSWILD:
1313 			/* "setserial -W" is called in Debian boot */
1314 			printk ("TIOCSER?WILD ioctl obsolete, ignored.\n");
1315 			return 0;
1316 
1317 		default:
1318 			return -ENOIOCTLCMD;
1319 		}
1320 	return 0;
1321 }
1322 
1323 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1324 {
1325 	struct serial_state *info = tty->driver_data;
1326 	unsigned long flags;
1327 	unsigned int cflag = tty->termios.c_cflag;
1328 
1329 	change_speed(tty, info, old_termios);
1330 
1331 	/* Handle transition to B0 status */
1332 	if ((old_termios->c_cflag & CBAUD) &&
1333 	    !(cflag & CBAUD)) {
1334 		info->MCR &= ~(SER_DTR|SER_RTS);
1335 		local_irq_save(flags);
1336 		rtsdtr_ctrl(info->MCR);
1337 		local_irq_restore(flags);
1338 	}
1339 
1340 	/* Handle transition away from B0 status */
1341 	if (!(old_termios->c_cflag & CBAUD) &&
1342 	    (cflag & CBAUD)) {
1343 		info->MCR |= SER_DTR;
1344 		if (!(tty->termios.c_cflag & CRTSCTS) ||
1345 		    !test_bit(TTY_THROTTLED, &tty->flags)) {
1346 			info->MCR |= SER_RTS;
1347 		}
1348 		local_irq_save(flags);
1349 		rtsdtr_ctrl(info->MCR);
1350 		local_irq_restore(flags);
1351 	}
1352 
1353 	/* Handle turning off CRTSCTS */
1354 	if ((old_termios->c_cflag & CRTSCTS) &&
1355 	    !(tty->termios.c_cflag & CRTSCTS)) {
1356 		tty->hw_stopped = 0;
1357 		rs_start(tty);
1358 	}
1359 
1360 #if 0
1361 	/*
1362 	 * No need to wake up processes in open wait, since they
1363 	 * sample the CLOCAL flag once, and don't recheck it.
1364 	 * XXX  It's not clear whether the current behavior is correct
1365 	 * or not.  Hence, this may change.....
1366 	 */
1367 	if (!(old_termios->c_cflag & CLOCAL) &&
1368 	    (tty->termios.c_cflag & CLOCAL))
1369 		wake_up_interruptible(&info->open_wait);
1370 #endif
1371 }
1372 
1373 /*
1374  * ------------------------------------------------------------
1375  * rs_close()
1376  *
1377  * This routine is called when the serial port gets closed.  First, we
1378  * wait for the last remaining data to be sent.  Then, we unlink its
1379  * async structure from the interrupt chain if necessary, and we free
1380  * that IRQ if nothing is left in the chain.
1381  * ------------------------------------------------------------
1382  */
1383 static void rs_close(struct tty_struct *tty, struct file * filp)
1384 {
1385 	struct serial_state *state = tty->driver_data;
1386 	struct tty_port *port = &state->tport;
1387 
1388 	if (serial_paranoia_check(state, tty->name, "rs_close"))
1389 		return;
1390 
1391 	if (tty_port_close_start(port, tty, filp) == 0)
1392 		return;
1393 
1394 	/*
1395 	 * At this point we stop accepting input.  To do this, we
1396 	 * disable the receive line status interrupts, and tell the
1397 	 * interrupt driver to stop checking the data ready bit in the
1398 	 * line status register.
1399 	 */
1400 	state->read_status_mask &= ~UART_LSR_DR;
1401 	if (port->flags & ASYNC_INITIALIZED) {
1402 	        /* disable receive interrupts */
1403 	        custom.intena = IF_RBF;
1404 		mb();
1405 		/* clear any pending receive interrupt */
1406 		custom.intreq = IF_RBF;
1407 		mb();
1408 
1409 		/*
1410 		 * Before we drop DTR, make sure the UART transmitter
1411 		 * has completely drained; this is especially
1412 		 * important if there is a transmit FIFO!
1413 		 */
1414 		rs_wait_until_sent(tty, state->timeout);
1415 	}
1416 	shutdown(tty, state);
1417 	rs_flush_buffer(tty);
1418 
1419 	tty_ldisc_flush(tty);
1420 	port->tty = NULL;
1421 
1422 	tty_port_close_end(port, tty);
1423 }
1424 
1425 /*
1426  * rs_wait_until_sent() --- wait until the transmitter is empty
1427  */
1428 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1429 {
1430 	struct serial_state *info = tty->driver_data;
1431 	unsigned long orig_jiffies, char_time;
1432 	int lsr;
1433 
1434 	if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1435 		return;
1436 
1437 	if (info->xmit_fifo_size == 0)
1438 		return; /* Just in case.... */
1439 
1440 	orig_jiffies = jiffies;
1441 
1442 	/*
1443 	 * Set the check interval to be 1/5 of the estimated time to
1444 	 * send a single character, and make it at least 1.  The check
1445 	 * interval should also be less than the timeout.
1446 	 *
1447 	 * Note: we have to use pretty tight timings here to satisfy
1448 	 * the NIST-PCTS.
1449 	 */
1450 	char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1451 	char_time = char_time / 5;
1452 	if (char_time == 0)
1453 		char_time = 1;
1454 	if (timeout)
1455 	  char_time = min_t(unsigned long, char_time, timeout);
1456 	/*
1457 	 * If the transmitter hasn't cleared in twice the approximate
1458 	 * amount of time to send the entire FIFO, it probably won't
1459 	 * ever clear.  This assumes the UART isn't doing flow
1460 	 * control, which is currently the case.  Hence, if it ever
1461 	 * takes longer than info->timeout, this is probably due to a
1462 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1463 	 * 2*info->timeout.
1464 	 */
1465 	if (!timeout || timeout > 2*info->timeout)
1466 		timeout = 2*info->timeout;
1467 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1468 	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1469 	printk("jiff=%lu...", jiffies);
1470 #endif
1471 	while(!((lsr = custom.serdatr) & SDR_TSRE)) {
1472 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1473 		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1474 #endif
1475 		msleep_interruptible(jiffies_to_msecs(char_time));
1476 		if (signal_pending(current))
1477 			break;
1478 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1479 			break;
1480 	}
1481 	__set_current_state(TASK_RUNNING);
1482 
1483 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1484 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1485 #endif
1486 }
1487 
1488 /*
1489  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1490  */
1491 static void rs_hangup(struct tty_struct *tty)
1492 {
1493 	struct serial_state *info = tty->driver_data;
1494 
1495 	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1496 		return;
1497 
1498 	rs_flush_buffer(tty);
1499 	shutdown(tty, info);
1500 	info->tport.count = 0;
1501 	info->tport.flags &= ~ASYNC_NORMAL_ACTIVE;
1502 	info->tport.tty = NULL;
1503 	wake_up_interruptible(&info->tport.open_wait);
1504 }
1505 
1506 /*
1507  * This routine is called whenever a serial port is opened.  It
1508  * enables interrupts for a serial port, linking in its async structure into
1509  * the IRQ chain.   It also performs the serial-specific
1510  * initialization for the tty structure.
1511  */
1512 static int rs_open(struct tty_struct *tty, struct file * filp)
1513 {
1514 	struct serial_state *info = rs_table + tty->index;
1515 	struct tty_port *port = &info->tport;
1516 	int retval;
1517 
1518 	port->count++;
1519 	port->tty = tty;
1520 	tty->driver_data = info;
1521 	tty->port = port;
1522 	if (serial_paranoia_check(info, tty->name, "rs_open"))
1523 		return -ENODEV;
1524 
1525 	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1526 
1527 	retval = startup(tty, info);
1528 	if (retval) {
1529 		return retval;
1530 	}
1531 
1532 	return tty_port_block_til_ready(port, tty, filp);
1533 }
1534 
1535 /*
1536  * /proc fs routines....
1537  */
1538 
1539 static inline void line_info(struct seq_file *m, int line,
1540 		struct serial_state *state)
1541 {
1542 	char	stat_buf[30], control, status;
1543 	unsigned long flags;
1544 
1545 	seq_printf(m, "%d: uart:amiga_builtin", line);
1546 
1547 	local_irq_save(flags);
1548 	status = ciab.pra;
1549 	control = (state->tport.flags & ASYNC_INITIALIZED) ? state->MCR : status;
1550 	local_irq_restore(flags);
1551 
1552 	stat_buf[0] = 0;
1553 	stat_buf[1] = 0;
1554 	if(!(control & SER_RTS))
1555 		strcat(stat_buf, "|RTS");
1556 	if(!(status & SER_CTS))
1557 		strcat(stat_buf, "|CTS");
1558 	if(!(control & SER_DTR))
1559 		strcat(stat_buf, "|DTR");
1560 	if(!(status & SER_DSR))
1561 		strcat(stat_buf, "|DSR");
1562 	if(!(status & SER_DCD))
1563 		strcat(stat_buf, "|CD");
1564 
1565 	if (state->quot)
1566 		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1567 
1568 	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1569 
1570 	if (state->icount.frame)
1571 		seq_printf(m, " fe:%d", state->icount.frame);
1572 
1573 	if (state->icount.parity)
1574 		seq_printf(m, " pe:%d", state->icount.parity);
1575 
1576 	if (state->icount.brk)
1577 		seq_printf(m, " brk:%d", state->icount.brk);
1578 
1579 	if (state->icount.overrun)
1580 		seq_printf(m, " oe:%d", state->icount.overrun);
1581 
1582 	/*
1583 	 * Last thing is the RS-232 status lines
1584 	 */
1585 	seq_printf(m, " %s\n", stat_buf+1);
1586 }
1587 
1588 static int rs_proc_show(struct seq_file *m, void *v)
1589 {
1590 	seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
1591 	line_info(m, 0, &rs_table[0]);
1592 	return 0;
1593 }
1594 
1595 static int rs_proc_open(struct inode *inode, struct file *file)
1596 {
1597 	return single_open(file, rs_proc_show, NULL);
1598 }
1599 
1600 static const struct file_operations rs_proc_fops = {
1601 	.owner		= THIS_MODULE,
1602 	.open		= rs_proc_open,
1603 	.read		= seq_read,
1604 	.llseek		= seq_lseek,
1605 	.release	= single_release,
1606 };
1607 
1608 /*
1609  * ---------------------------------------------------------------------
1610  * rs_init() and friends
1611  *
1612  * rs_init() is called at boot-time to initialize the serial driver.
1613  * ---------------------------------------------------------------------
1614  */
1615 
1616 /*
1617  * This routine prints out the appropriate serial driver version
1618  * number, and identifies which options were configured into this
1619  * driver.
1620  */
1621 static void show_serial_version(void)
1622 {
1623  	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
1624 }
1625 
1626 
1627 static const struct tty_operations serial_ops = {
1628 	.open = rs_open,
1629 	.close = rs_close,
1630 	.write = rs_write,
1631 	.put_char = rs_put_char,
1632 	.flush_chars = rs_flush_chars,
1633 	.write_room = rs_write_room,
1634 	.chars_in_buffer = rs_chars_in_buffer,
1635 	.flush_buffer = rs_flush_buffer,
1636 	.ioctl = rs_ioctl,
1637 	.throttle = rs_throttle,
1638 	.unthrottle = rs_unthrottle,
1639 	.set_termios = rs_set_termios,
1640 	.stop = rs_stop,
1641 	.start = rs_start,
1642 	.hangup = rs_hangup,
1643 	.break_ctl = rs_break,
1644 	.send_xchar = rs_send_xchar,
1645 	.wait_until_sent = rs_wait_until_sent,
1646 	.tiocmget = rs_tiocmget,
1647 	.tiocmset = rs_tiocmset,
1648 	.get_icount = rs_get_icount,
1649 	.proc_fops = &rs_proc_fops,
1650 };
1651 
1652 static int amiga_carrier_raised(struct tty_port *port)
1653 {
1654 	return !(ciab.pra & SER_DCD);
1655 }
1656 
1657 static void amiga_dtr_rts(struct tty_port *port, int raise)
1658 {
1659 	struct serial_state *info = container_of(port, struct serial_state,
1660 			tport);
1661 	unsigned long flags;
1662 
1663 	if (raise)
1664 		info->MCR |= SER_DTR|SER_RTS;
1665 	else
1666 		info->MCR &= ~(SER_DTR|SER_RTS);
1667 
1668 	local_irq_save(flags);
1669 	rtsdtr_ctrl(info->MCR);
1670 	local_irq_restore(flags);
1671 }
1672 
1673 static const struct tty_port_operations amiga_port_ops = {
1674 	.carrier_raised = amiga_carrier_raised,
1675 	.dtr_rts = amiga_dtr_rts,
1676 };
1677 
1678 /*
1679  * The serial driver boot-time initialization code!
1680  */
1681 static int __init amiga_serial_probe(struct platform_device *pdev)
1682 {
1683 	unsigned long flags;
1684 	struct serial_state * state;
1685 	int error;
1686 
1687 	serial_driver = alloc_tty_driver(NR_PORTS);
1688 	if (!serial_driver)
1689 		return -ENOMEM;
1690 
1691 	show_serial_version();
1692 
1693 	/* Initialize the tty_driver structure */
1694 
1695 	serial_driver->driver_name = "amiserial";
1696 	serial_driver->name = "ttyS";
1697 	serial_driver->major = TTY_MAJOR;
1698 	serial_driver->minor_start = 64;
1699 	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1700 	serial_driver->subtype = SERIAL_TYPE_NORMAL;
1701 	serial_driver->init_termios = tty_std_termios;
1702 	serial_driver->init_termios.c_cflag =
1703 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1704 	serial_driver->flags = TTY_DRIVER_REAL_RAW;
1705 	tty_set_operations(serial_driver, &serial_ops);
1706 
1707 	state = rs_table;
1708 	state->port = (int)&custom.serdatr; /* Just to give it a value */
1709 	state->custom_divisor = 0;
1710 	state->icount.cts = state->icount.dsr =
1711 	  state->icount.rng = state->icount.dcd = 0;
1712 	state->icount.rx = state->icount.tx = 0;
1713 	state->icount.frame = state->icount.parity = 0;
1714 	state->icount.overrun = state->icount.brk = 0;
1715 	tty_port_init(&state->tport);
1716 	state->tport.ops = &amiga_port_ops;
1717 	tty_port_link_device(&state->tport, serial_driver, 0);
1718 
1719 	error = tty_register_driver(serial_driver);
1720 	if (error)
1721 		goto fail_put_tty_driver;
1722 
1723 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1724 
1725 	/* Hardware set up */
1726 
1727 	state->baud_base = amiga_colorclock;
1728 	state->xmit_fifo_size = 1;
1729 
1730 	/* set ISRs, and then disable the rx interrupts */
1731 	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1732 	if (error)
1733 		goto fail_unregister;
1734 
1735 	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1736 			    "serial RX", state);
1737 	if (error)
1738 		goto fail_free_irq;
1739 
1740 	local_irq_save(flags);
1741 
1742 	/* turn off Rx and Tx interrupts */
1743 	custom.intena = IF_RBF | IF_TBE;
1744 	mb();
1745 
1746 	/* clear any pending interrupt */
1747 	custom.intreq = IF_RBF | IF_TBE;
1748 	mb();
1749 
1750 	local_irq_restore(flags);
1751 
1752 	/*
1753 	 * set the appropriate directions for the modem control flags,
1754 	 * and clear RTS and DTR
1755 	 */
1756 	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1757 	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1758 
1759 	platform_set_drvdata(pdev, state);
1760 
1761 	return 0;
1762 
1763 fail_free_irq:
1764 	free_irq(IRQ_AMIGA_TBE, state);
1765 fail_unregister:
1766 	tty_unregister_driver(serial_driver);
1767 fail_put_tty_driver:
1768 	tty_port_destroy(&state->tport);
1769 	put_tty_driver(serial_driver);
1770 	return error;
1771 }
1772 
1773 static int __exit amiga_serial_remove(struct platform_device *pdev)
1774 {
1775 	int error;
1776 	struct serial_state *state = platform_get_drvdata(pdev);
1777 
1778 	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
1779 	if ((error = tty_unregister_driver(serial_driver)))
1780 		printk("SERIAL: failed to unregister serial driver (%d)\n",
1781 		       error);
1782 	put_tty_driver(serial_driver);
1783 	tty_port_destroy(&state->tport);
1784 
1785 	free_irq(IRQ_AMIGA_TBE, state);
1786 	free_irq(IRQ_AMIGA_RBF, state);
1787 
1788 	platform_set_drvdata(pdev, NULL);
1789 
1790 	return error;
1791 }
1792 
1793 static struct platform_driver amiga_serial_driver = {
1794 	.remove = __exit_p(amiga_serial_remove),
1795 	.driver   = {
1796 		.name	= "amiga-serial",
1797 		.owner	= THIS_MODULE,
1798 	},
1799 };
1800 
1801 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1802 
1803 
1804 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1805 
1806 /*
1807  * ------------------------------------------------------------
1808  * Serial console driver
1809  * ------------------------------------------------------------
1810  */
1811 
1812 static void amiga_serial_putc(char c)
1813 {
1814 	custom.serdat = (unsigned char)c | 0x100;
1815 	while (!(custom.serdatr & 0x2000))
1816 		barrier();
1817 }
1818 
1819 /*
1820  *	Print a string to the serial port trying not to disturb
1821  *	any possible real use of the port...
1822  *
1823  *	The console must be locked when we get here.
1824  */
1825 static void serial_console_write(struct console *co, const char *s,
1826 				unsigned count)
1827 {
1828 	unsigned short intena = custom.intenar;
1829 
1830 	custom.intena = IF_TBE;
1831 
1832 	while (count--) {
1833 		if (*s == '\n')
1834 			amiga_serial_putc('\r');
1835 		amiga_serial_putc(*s++);
1836 	}
1837 
1838 	custom.intena = IF_SETCLR | (intena & IF_TBE);
1839 }
1840 
1841 static struct tty_driver *serial_console_device(struct console *c, int *index)
1842 {
1843 	*index = 0;
1844 	return serial_driver;
1845 }
1846 
1847 static struct console sercons = {
1848 	.name =		"ttyS",
1849 	.write =	serial_console_write,
1850 	.device =	serial_console_device,
1851 	.flags =	CON_PRINTBUFFER,
1852 	.index =	-1,
1853 };
1854 
1855 /*
1856  *	Register console.
1857  */
1858 static int __init amiserial_console_init(void)
1859 {
1860 	register_console(&sercons);
1861 	return 0;
1862 }
1863 console_initcall(amiserial_console_init);
1864 
1865 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1866 
1867 MODULE_LICENSE("GPL");
1868 MODULE_ALIAS("platform:amiga-serial");
1869