xref: /linux/drivers/tty/amiserial.c (revision e70140ba0d2b1a30467d4af6bcfe761327b9ec95)
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 	u8			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 			 const 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 
rtsdtr_ctrl(int bits)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  */
rs_stop(struct tty_struct * tty)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 
rs_start(struct tty_struct * tty)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 
receive_chars(struct serial_state * info)177 static void receive_chars(struct serial_state *info)
178 {
179         int status;
180 	int serdatr;
181 	u8 ch, flag;
182 	struct	async_icount *icount;
183 	bool overrun = false;
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 		  return;
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 	     overrun = true;
255 	  }
256 	}
257 	tty_insert_flip_char(&info->tport, ch, flag);
258 	if (overrun)
259 		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
260 	tty_flip_buffer_push(&info->tport);
261 }
262 
transmit_chars(struct serial_state * info)263 static void transmit_chars(struct serial_state *info)
264 {
265 	amiga_custom.intreq = IF_TBE;
266 	mb();
267 	if (info->x_char) {
268 	        amiga_custom.serdat = info->x_char | 0x100;
269 		mb();
270 		info->icount.tx++;
271 		info->x_char = 0;
272 		return;
273 	}
274 	if (info->xmit.head == info->xmit.tail
275 	    || info->tport.tty->flow.stopped
276 	    || info->tport.tty->hw_stopped) {
277 		info->IER &= ~UART_IER_THRI;
278 	        amiga_custom.intena = IF_TBE;
279 		mb();
280 		return;
281 	}
282 
283 	amiga_custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
284 	mb();
285 	info->xmit.tail = info->xmit.tail & (UART_XMIT_SIZE - 1);
286 	info->icount.tx++;
287 
288 	if (CIRC_CNT(info->xmit.head,
289 		     info->xmit.tail,
290 		     UART_XMIT_SIZE) < WAKEUP_CHARS)
291 		tty_wakeup(info->tport.tty);
292 
293 #ifdef SERIAL_DEBUG_INTR
294 	printk("THRE...");
295 #endif
296 	if (info->xmit.head == info->xmit.tail) {
297 	        amiga_custom.intena = IF_TBE;
298 		mb();
299 		info->IER &= ~UART_IER_THRI;
300 	}
301 }
302 
check_modem_status(struct serial_state * info)303 static void check_modem_status(struct serial_state *info)
304 {
305 	struct tty_port *port = &info->tport;
306 	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
307 	unsigned char dstatus;
308 	struct	async_icount *icount;
309 
310 	/* Determine bits that have changed */
311 	dstatus = status ^ current_ctl_bits;
312 	current_ctl_bits = status;
313 
314 	if (dstatus) {
315 		icount = &info->icount;
316 		/* update input line counters */
317 		if (dstatus & SER_DSR)
318 			icount->dsr++;
319 		if (dstatus & SER_DCD) {
320 			icount->dcd++;
321 		}
322 		if (dstatus & SER_CTS)
323 			icount->cts++;
324 		wake_up_interruptible(&port->delta_msr_wait);
325 	}
326 
327 	if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
328 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
329 		printk("ttyS%d CD now %s...", info->line,
330 		       (!(status & SER_DCD)) ? "on" : "off");
331 #endif
332 		if (!(status & SER_DCD))
333 			wake_up_interruptible(&port->open_wait);
334 		else {
335 #ifdef SERIAL_DEBUG_OPEN
336 			printk("doing serial hangup...");
337 #endif
338 			if (port->tty)
339 				tty_hangup(port->tty);
340 		}
341 	}
342 	if (tty_port_cts_enabled(port)) {
343 		if (port->tty->hw_stopped) {
344 			if (!(status & SER_CTS)) {
345 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
346 				printk("CTS tx start...");
347 #endif
348 				port->tty->hw_stopped = false;
349 				info->IER |= UART_IER_THRI;
350 				amiga_custom.intena = IF_SETCLR | IF_TBE;
351 				mb();
352 				/* set a pending Tx Interrupt, transmitter should restart now */
353 				amiga_custom.intreq = IF_SETCLR | IF_TBE;
354 				mb();
355 				tty_wakeup(port->tty);
356 				return;
357 			}
358 		} else {
359 			if ((status & SER_CTS)) {
360 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
361 				printk("CTS tx stop...");
362 #endif
363 				port->tty->hw_stopped = true;
364 				info->IER &= ~UART_IER_THRI;
365 				/* disable Tx interrupt and remove any pending interrupts */
366 				amiga_custom.intena = IF_TBE;
367 				mb();
368 				amiga_custom.intreq = IF_TBE;
369 				mb();
370 			}
371 		}
372 	}
373 }
374 
ser_vbl_int(int irq,void * data)375 static irqreturn_t ser_vbl_int( int irq, void *data)
376 {
377         /* vbl is just a periodic interrupt we tie into to update modem status */
378 	struct serial_state *info = data;
379 	/*
380 	 * TBD - is it better to unregister from this interrupt or to
381 	 * ignore it if MSI is clear ?
382 	 */
383 	if(info->IER & UART_IER_MSI)
384 	  check_modem_status(info);
385 	return IRQ_HANDLED;
386 }
387 
ser_rx_int(int irq,void * dev_id)388 static irqreturn_t ser_rx_int(int irq, void *dev_id)
389 {
390 	struct serial_state *info = dev_id;
391 
392 #ifdef SERIAL_DEBUG_INTR
393 	printk("ser_rx_int...");
394 #endif
395 
396 	if (!info->tport.tty)
397 		return IRQ_NONE;
398 
399 	receive_chars(info);
400 #ifdef SERIAL_DEBUG_INTR
401 	printk("end.\n");
402 #endif
403 	return IRQ_HANDLED;
404 }
405 
ser_tx_int(int irq,void * dev_id)406 static irqreturn_t ser_tx_int(int irq, void *dev_id)
407 {
408 	struct serial_state *info = dev_id;
409 
410 	if (amiga_custom.serdatr & SDR_TBE) {
411 #ifdef SERIAL_DEBUG_INTR
412 	  printk("ser_tx_int...");
413 #endif
414 
415 	  if (!info->tport.tty)
416 		return IRQ_NONE;
417 
418 	  transmit_chars(info);
419 #ifdef SERIAL_DEBUG_INTR
420 	  printk("end.\n");
421 #endif
422 	}
423 	return IRQ_HANDLED;
424 }
425 
426 /*
427  * -------------------------------------------------------------------
428  * Here ends the serial interrupt routines.
429  * -------------------------------------------------------------------
430  */
431 
432 /*
433  * ---------------------------------------------------------------
434  * Low level utility subroutines for the serial driver:  routines to
435  * figure out the appropriate timeout for an interrupt chain, routines
436  * to initialize and startup a serial port, and routines to shutdown a
437  * serial port.  Useful stuff like that.
438  * ---------------------------------------------------------------
439  */
440 
startup(struct tty_struct * tty,struct serial_state * info)441 static int startup(struct tty_struct *tty, struct serial_state *info)
442 {
443 	struct tty_port *port = &info->tport;
444 	unsigned long flags;
445 	int	retval=0;
446 	unsigned long page;
447 
448 	page = get_zeroed_page(GFP_KERNEL);
449 	if (!page)
450 		return -ENOMEM;
451 
452 	local_irq_save(flags);
453 
454 	if (tty_port_initialized(port)) {
455 		free_page(page);
456 		goto errout;
457 	}
458 
459 	if (info->xmit.buf)
460 		free_page(page);
461 	else
462 		info->xmit.buf = (unsigned char *) page;
463 
464 #ifdef SERIAL_DEBUG_OPEN
465 	printk("starting up ttys%d ...", info->line);
466 #endif
467 
468 	/* Clear anything in the input buffer */
469 
470 	amiga_custom.intreq = IF_RBF;
471 	mb();
472 
473 	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
474 	if (retval) {
475 		if (capable(CAP_SYS_ADMIN)) {
476 			set_bit(TTY_IO_ERROR, &tty->flags);
477 			retval = 0;
478 		}
479 		goto errout;
480 	}
481 
482 	/* enable both Rx and Tx interrupts */
483 	amiga_custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
484 	mb();
485 	info->IER = UART_IER_MSI;
486 
487 	/* remember current state of the DCD and CTS bits */
488 	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
489 
490 	info->MCR = 0;
491 	if (C_BAUD(tty))
492 	  info->MCR = SER_DTR | SER_RTS;
493 	rtsdtr_ctrl(info->MCR);
494 
495 	clear_bit(TTY_IO_ERROR, &tty->flags);
496 	info->xmit.head = info->xmit.tail = 0;
497 
498 	/*
499 	 * and set the speed of the serial port
500 	 */
501 	change_speed(tty, info, NULL);
502 
503 	tty_port_set_initialized(port, true);
504 	local_irq_restore(flags);
505 	return 0;
506 
507 errout:
508 	local_irq_restore(flags);
509 	return retval;
510 }
511 
512 /*
513  * This routine will shutdown a serial port; interrupts are disabled, and
514  * DTR is dropped if the hangup on close termio flag is on.
515  */
shutdown(struct tty_struct * tty,struct serial_state * info)516 static void shutdown(struct tty_struct *tty, struct serial_state *info)
517 {
518 	unsigned long	flags;
519 
520 	if (!tty_port_initialized(&info->tport))
521 		return;
522 
523 #ifdef SERIAL_DEBUG_OPEN
524 	printk("Shutting down serial port %d ....\n", info->line);
525 #endif
526 
527 	local_irq_save(flags); /* Disable interrupts */
528 
529 	/*
530 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
531 	 * here so the queue might never be waken up
532 	 */
533 	wake_up_interruptible(&info->tport.delta_msr_wait);
534 
535 	/*
536 	 * Free the IRQ, if necessary
537 	 */
538 	free_irq(IRQ_AMIGA_VERTB, info);
539 
540 	free_page((unsigned long)info->xmit.buf);
541 	info->xmit.buf = NULL;
542 
543 	info->IER = 0;
544 	amiga_custom.intena = IF_RBF | IF_TBE;
545 	mb();
546 
547 	/* disable break condition */
548 	amiga_custom.adkcon = AC_UARTBRK;
549 	mb();
550 
551 	if (C_HUPCL(tty))
552 		info->MCR &= ~(SER_DTR|SER_RTS);
553 	rtsdtr_ctrl(info->MCR);
554 
555 	set_bit(TTY_IO_ERROR, &tty->flags);
556 
557 	tty_port_set_initialized(&info->tport, false);
558 	local_irq_restore(flags);
559 }
560 
561 
562 /*
563  * This routine is called to set the UART divisor registers to match
564  * the specified baud rate for a serial port.
565  */
change_speed(struct tty_struct * tty,struct serial_state * info,const struct ktermios * old_termios)566 static void change_speed(struct tty_struct *tty, struct serial_state *info,
567 			 const struct ktermios *old_termios)
568 {
569 	struct tty_port *port = &info->tport;
570 	int	quot = 0, baud_base, baud;
571 	unsigned cflag, cval = 0;
572 	int	bits;
573 	unsigned long	flags;
574 
575 	cflag = tty->termios.c_cflag;
576 
577 	/* Byte size is always 8 bits plus parity bit if requested */
578 
579 	cval = 3; bits = 10;
580 	if (cflag & CSTOPB) {
581 		cval |= 0x04;
582 		bits++;
583 	}
584 	if (cflag & PARENB) {
585 		cval |= UART_LCR_PARITY;
586 		bits++;
587 	}
588 	if (!(cflag & PARODD))
589 		cval |= UART_LCR_EPAR;
590 	if (cflag & CMSPAR)
591 		cval |= UART_LCR_SPAR;
592 
593 	/* Determine divisor based on baud rate */
594 	baud = tty_get_baud_rate(tty);
595 	if (!baud)
596 		baud = 9600;	/* B0 transition handled in rs_set_termios */
597 	baud_base = info->baud_base;
598 	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
599 		quot = info->custom_divisor;
600 	else {
601 		if (baud == 134)
602 			/* Special case since 134 is really 134.5 */
603 			quot = (2*baud_base / 269);
604 		else if (baud)
605 			quot = baud_base / baud;
606 	}
607 	/* If the quotient is zero refuse the change */
608 	if (!quot && old_termios) {
609 		/* FIXME: Will need updating for new tty in the end */
610 		tty->termios.c_cflag &= ~CBAUD;
611 		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
612 		baud = tty_get_baud_rate(tty);
613 		if (!baud)
614 			baud = 9600;
615 		if (baud == 38400 &&
616 		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
617 			quot = info->custom_divisor;
618 		else {
619 			if (baud == 134)
620 				/* Special case since 134 is really 134.5 */
621 				quot = (2*baud_base / 269);
622 			else if (baud)
623 				quot = baud_base / baud;
624 		}
625 	}
626 	/* As a last resort, if the quotient is zero, default to 9600 bps */
627 	if (!quot)
628 		quot = baud_base / 9600;
629 	info->quot = quot;
630 	info->timeout = (XMIT_FIFO_SIZE*HZ*bits*quot) / baud_base;
631 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
632 
633 	/* CTS flow control flag and modem status interrupts */
634 	info->IER &= ~UART_IER_MSI;
635 	if (port->flags & ASYNC_HARDPPS_CD)
636 		info->IER |= UART_IER_MSI;
637 	tty_port_set_cts_flow(port, cflag & CRTSCTS);
638 	if (cflag & CRTSCTS)
639 		info->IER |= UART_IER_MSI;
640 	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
641 	if (~cflag & CLOCAL)
642 		info->IER |= UART_IER_MSI;
643 	/* TBD:
644 	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
645 	 */
646 
647 	/*
648 	 * Set up parity check flag
649 	 */
650 
651 	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
652 	if (I_INPCK(tty))
653 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
654 	if (I_BRKINT(tty) || I_PARMRK(tty))
655 		info->read_status_mask |= UART_LSR_BI;
656 
657 	/*
658 	 * Characters to ignore
659 	 */
660 	info->ignore_status_mask = 0;
661 	if (I_IGNPAR(tty))
662 		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
663 	if (I_IGNBRK(tty)) {
664 		info->ignore_status_mask |= UART_LSR_BI;
665 		/*
666 		 * If we're ignore parity and break indicators, ignore
667 		 * overruns too.  (For real raw support).
668 		 */
669 		if (I_IGNPAR(tty))
670 			info->ignore_status_mask |= UART_LSR_OE;
671 	}
672 	/*
673 	 * !!! ignore all characters if CREAD is not set
674 	 */
675 	if ((cflag & CREAD) == 0)
676 		info->ignore_status_mask |= UART_LSR_DR;
677 	local_irq_save(flags);
678 
679 	{
680 	  short serper;
681 
682 	/* Set up the baud rate */
683 	  serper = quot - 1;
684 
685 	/* Enable or disable parity bit */
686 
687 	if(cval & UART_LCR_PARITY)
688 	  serper |= (SERPER_PARENB);
689 
690 	amiga_custom.serper = serper;
691 	mb();
692 	}
693 
694 	local_irq_restore(flags);
695 }
696 
rs_put_char(struct tty_struct * tty,u8 ch)697 static int rs_put_char(struct tty_struct *tty, u8 ch)
698 {
699 	struct serial_state *info;
700 	unsigned long flags;
701 
702 	info = tty->driver_data;
703 
704 	if (!info->xmit.buf)
705 		return 0;
706 
707 	local_irq_save(flags);
708 	if (CIRC_SPACE(info->xmit.head,
709 		       info->xmit.tail,
710 		       UART_XMIT_SIZE) == 0) {
711 		local_irq_restore(flags);
712 		return 0;
713 	}
714 
715 	info->xmit.buf[info->xmit.head++] = ch;
716 	info->xmit.head &= UART_XMIT_SIZE - 1;
717 	local_irq_restore(flags);
718 	return 1;
719 }
720 
rs_flush_chars(struct tty_struct * tty)721 static void rs_flush_chars(struct tty_struct *tty)
722 {
723 	struct serial_state *info = tty->driver_data;
724 	unsigned long flags;
725 
726 	if (info->xmit.head == info->xmit.tail
727 	    || tty->flow.stopped
728 	    || tty->hw_stopped
729 	    || !info->xmit.buf)
730 		return;
731 
732 	local_irq_save(flags);
733 	info->IER |= UART_IER_THRI;
734 	amiga_custom.intena = IF_SETCLR | IF_TBE;
735 	mb();
736 	/* set a pending Tx Interrupt, transmitter should restart now */
737 	amiga_custom.intreq = IF_SETCLR | IF_TBE;
738 	mb();
739 	local_irq_restore(flags);
740 }
741 
rs_write(struct tty_struct * tty,const u8 * buf,size_t count)742 static ssize_t rs_write(struct tty_struct * tty, const u8 *buf, size_t count)
743 {
744 	int	c, ret = 0;
745 	struct serial_state *info = tty->driver_data;
746 	unsigned long flags;
747 
748 	if (!info->xmit.buf)
749 		return 0;
750 
751 	local_irq_save(flags);
752 	while (1) {
753 		c = CIRC_SPACE_TO_END(info->xmit.head,
754 				      info->xmit.tail,
755 				      UART_XMIT_SIZE);
756 		if (count < c)
757 			c = count;
758 		if (c <= 0) {
759 			break;
760 		}
761 		memcpy(info->xmit.buf + info->xmit.head, buf, c);
762 		info->xmit.head = (info->xmit.head + c) & (UART_XMIT_SIZE - 1);
763 		buf += c;
764 		count -= c;
765 		ret += c;
766 	}
767 	local_irq_restore(flags);
768 
769 	if (info->xmit.head != info->xmit.tail
770 	    && !tty->flow.stopped
771 	    && !tty->hw_stopped
772 	    && !(info->IER & UART_IER_THRI)) {
773 		info->IER |= UART_IER_THRI;
774 		local_irq_disable();
775 		amiga_custom.intena = IF_SETCLR | IF_TBE;
776 		mb();
777 		/* set a pending Tx Interrupt, transmitter should restart now */
778 		amiga_custom.intreq = IF_SETCLR | IF_TBE;
779 		mb();
780 		local_irq_restore(flags);
781 	}
782 	return ret;
783 }
784 
rs_write_room(struct tty_struct * tty)785 static unsigned int rs_write_room(struct tty_struct *tty)
786 {
787 	struct serial_state *info = tty->driver_data;
788 
789 	return CIRC_SPACE(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
790 }
791 
rs_chars_in_buffer(struct tty_struct * tty)792 static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
793 {
794 	struct serial_state *info = tty->driver_data;
795 
796 	return CIRC_CNT(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
797 }
798 
rs_flush_buffer(struct tty_struct * tty)799 static void rs_flush_buffer(struct tty_struct *tty)
800 {
801 	struct serial_state *info = tty->driver_data;
802 	unsigned long flags;
803 
804 	local_irq_save(flags);
805 	info->xmit.head = info->xmit.tail = 0;
806 	local_irq_restore(flags);
807 	tty_wakeup(tty);
808 }
809 
810 /*
811  * This function is used to send a high-priority XON/XOFF character to
812  * the device
813  */
rs_send_xchar(struct tty_struct * tty,u8 ch)814 static void rs_send_xchar(struct tty_struct *tty, u8 ch)
815 {
816 	struct serial_state *info = tty->driver_data;
817         unsigned long flags;
818 
819 	info->x_char = ch;
820 	if (ch) {
821 		/* Make sure transmit interrupts are on */
822 
823 	        /* Check this ! */
824 	        local_irq_save(flags);
825 		if(!(amiga_custom.intenar & IF_TBE)) {
826 		    amiga_custom.intena = IF_SETCLR | IF_TBE;
827 		    mb();
828 		    /* set a pending Tx Interrupt, transmitter should restart now */
829 		    amiga_custom.intreq = IF_SETCLR | IF_TBE;
830 		    mb();
831 		}
832 		local_irq_restore(flags);
833 
834 		info->IER |= UART_IER_THRI;
835 	}
836 }
837 
838 /*
839  * ------------------------------------------------------------
840  * rs_throttle()
841  *
842  * This routine is called by the upper-layer tty layer to signal that
843  * incoming characters should be throttled.
844  * ------------------------------------------------------------
845  */
rs_throttle(struct tty_struct * tty)846 static void rs_throttle(struct tty_struct * tty)
847 {
848 	struct serial_state *info = tty->driver_data;
849 	unsigned long flags;
850 #ifdef SERIAL_DEBUG_THROTTLE
851 	printk("throttle %s ....\n", tty_name(tty));
852 #endif
853 
854 	if (I_IXOFF(tty))
855 		rs_send_xchar(tty, STOP_CHAR(tty));
856 
857 	if (C_CRTSCTS(tty))
858 		info->MCR &= ~SER_RTS;
859 
860 	local_irq_save(flags);
861 	rtsdtr_ctrl(info->MCR);
862 	local_irq_restore(flags);
863 }
864 
rs_unthrottle(struct tty_struct * tty)865 static void rs_unthrottle(struct tty_struct * tty)
866 {
867 	struct serial_state *info = tty->driver_data;
868 	unsigned long flags;
869 #ifdef SERIAL_DEBUG_THROTTLE
870 	printk("unthrottle %s ....\n", tty_name(tty));
871 #endif
872 
873 	if (I_IXOFF(tty)) {
874 		if (info->x_char)
875 			info->x_char = 0;
876 		else
877 			rs_send_xchar(tty, START_CHAR(tty));
878 	}
879 	if (C_CRTSCTS(tty))
880 		info->MCR |= SER_RTS;
881 	local_irq_save(flags);
882 	rtsdtr_ctrl(info->MCR);
883 	local_irq_restore(flags);
884 }
885 
886 /*
887  * ------------------------------------------------------------
888  * rs_ioctl() and friends
889  * ------------------------------------------------------------
890  */
891 
get_serial_info(struct tty_struct * tty,struct serial_struct * ss)892 static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
893 {
894 	struct serial_state *state = tty->driver_data;
895 	unsigned int close_delay, closing_wait;
896 
897 	tty_lock(tty);
898 	close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
899 	closing_wait = state->tport.closing_wait;
900 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
901 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
902 
903 	ss->line = tty->index;
904 	ss->port = state->port;
905 	ss->flags = state->tport.flags;
906 	ss->xmit_fifo_size = XMIT_FIFO_SIZE;
907 	ss->baud_base = state->baud_base;
908 	ss->close_delay = close_delay;
909 	ss->closing_wait = closing_wait;
910 	ss->custom_divisor = state->custom_divisor;
911 	tty_unlock(tty);
912 	return 0;
913 }
914 
set_serial_info(struct tty_struct * tty,struct serial_struct * ss)915 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
916 {
917 	struct serial_state *state = tty->driver_data;
918 	struct tty_port *port = &state->tport;
919 	bool change_spd;
920 	int 			retval = 0;
921 	unsigned int close_delay, closing_wait;
922 
923 	tty_lock(tty);
924 	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
925 		ss->custom_divisor != state->custom_divisor;
926 	if (ss->irq || ss->port != state->port ||
927 			ss->xmit_fifo_size != XMIT_FIFO_SIZE) {
928 		tty_unlock(tty);
929 		return -EINVAL;
930 	}
931 
932 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
933 	closing_wait = ss->closing_wait;
934 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
935 		closing_wait = msecs_to_jiffies(closing_wait * 10);
936 
937 	if (!capable(CAP_SYS_ADMIN)) {
938 		if ((ss->baud_base != state->baud_base) ||
939 		    (close_delay != port->close_delay) ||
940 		    (closing_wait != port->closing_wait) ||
941 		    ((ss->flags & ~ASYNC_USR_MASK) !=
942 		     (port->flags & ~ASYNC_USR_MASK))) {
943 			tty_unlock(tty);
944 			return -EPERM;
945 		}
946 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
947 			       (ss->flags & ASYNC_USR_MASK));
948 		state->custom_divisor = ss->custom_divisor;
949 		goto check_and_exit;
950 	}
951 
952 	if (ss->baud_base < 9600) {
953 		tty_unlock(tty);
954 		return -EINVAL;
955 	}
956 
957 	/*
958 	 * OK, past this point, all the error checking has been done.
959 	 * At this point, we start making changes.....
960 	 */
961 
962 	state->baud_base = ss->baud_base;
963 	port->flags = ((port->flags & ~ASYNC_FLAGS) |
964 			(ss->flags & ASYNC_FLAGS));
965 	state->custom_divisor = ss->custom_divisor;
966 	port->close_delay = close_delay;
967 	port->closing_wait = closing_wait;
968 
969 check_and_exit:
970 	if (tty_port_initialized(port)) {
971 		if (change_spd) {
972 			/* warn about deprecation unless clearing */
973 			if (ss->flags & ASYNC_SPD_MASK)
974 				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
975 			change_speed(tty, state, NULL);
976 		}
977 	} else
978 		retval = startup(tty, state);
979 	tty_unlock(tty);
980 	return retval;
981 }
982 
983 /*
984  * get_lsr_info - get line status register info
985  *
986  * Purpose: Let user call ioctl() to get info when the UART physically
987  * 	    is emptied.  On bus types like RS485, the transmitter must
988  * 	    release the bus after transmitting. This must be done when
989  * 	    the transmit shift register is empty, not be done when the
990  * 	    transmit holding register is empty.  This functionality
991  * 	    allows an RS485 driver to be written in user space.
992  */
get_lsr_info(struct serial_state * info,unsigned int __user * value)993 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
994 {
995 	unsigned char status;
996 	unsigned int result;
997 	unsigned long flags;
998 
999 	local_irq_save(flags);
1000 	status = amiga_custom.serdatr;
1001 	mb();
1002 	local_irq_restore(flags);
1003 	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1004 	if (copy_to_user(value, &result, sizeof(int)))
1005 		return -EFAULT;
1006 	return 0;
1007 }
1008 
1009 
rs_tiocmget(struct tty_struct * tty)1010 static int rs_tiocmget(struct tty_struct *tty)
1011 {
1012 	struct serial_state *info = tty->driver_data;
1013 	unsigned char control, status;
1014 	unsigned long flags;
1015 
1016 	if (tty_io_error(tty))
1017 		return -EIO;
1018 
1019 	control = info->MCR;
1020 	local_irq_save(flags);
1021 	status = ciab.pra;
1022 	local_irq_restore(flags);
1023 	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1024 		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1025 		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1026 		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1027 		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1028 }
1029 
rs_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)1030 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1031 						unsigned int clear)
1032 {
1033 	struct serial_state *info = tty->driver_data;
1034 	unsigned long flags;
1035 
1036 	if (tty_io_error(tty))
1037 		return -EIO;
1038 
1039 	local_irq_save(flags);
1040 	if (set & TIOCM_RTS)
1041 		info->MCR |= SER_RTS;
1042 	if (set & TIOCM_DTR)
1043 		info->MCR |= SER_DTR;
1044 	if (clear & TIOCM_RTS)
1045 		info->MCR &= ~SER_RTS;
1046 	if (clear & TIOCM_DTR)
1047 		info->MCR &= ~SER_DTR;
1048 	rtsdtr_ctrl(info->MCR);
1049 	local_irq_restore(flags);
1050 	return 0;
1051 }
1052 
1053 /*
1054  * rs_break() --- routine which turns the break handling on or off
1055  */
rs_break(struct tty_struct * tty,int break_state)1056 static int rs_break(struct tty_struct *tty, int break_state)
1057 {
1058 	unsigned long flags;
1059 
1060 	local_irq_save(flags);
1061 	if (break_state == -1)
1062 	  amiga_custom.adkcon = AC_SETCLR | AC_UARTBRK;
1063 	else
1064 	  amiga_custom.adkcon = AC_UARTBRK;
1065 	mb();
1066 	local_irq_restore(flags);
1067 	return 0;
1068 }
1069 
1070 /*
1071  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1072  * Return: write counters to the user passed counter struct
1073  * NB: both 1->0 and 0->1 transitions are counted except for
1074  *     RI where only 0->1 is counted.
1075  */
rs_get_icount(struct tty_struct * tty,struct serial_icounter_struct * icount)1076 static int rs_get_icount(struct tty_struct *tty,
1077 				struct serial_icounter_struct *icount)
1078 {
1079 	struct serial_state *info = tty->driver_data;
1080 	struct async_icount cnow;
1081 	unsigned long flags;
1082 
1083 	local_irq_save(flags);
1084 	cnow = info->icount;
1085 	local_irq_restore(flags);
1086 	icount->cts = cnow.cts;
1087 	icount->dsr = cnow.dsr;
1088 	icount->rng = cnow.rng;
1089 	icount->dcd = cnow.dcd;
1090 	icount->rx = cnow.rx;
1091 	icount->tx = cnow.tx;
1092 	icount->frame = cnow.frame;
1093 	icount->overrun = cnow.overrun;
1094 	icount->parity = cnow.parity;
1095 	icount->brk = cnow.brk;
1096 	icount->buf_overrun = cnow.buf_overrun;
1097 
1098 	return 0;
1099 }
1100 
rs_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)1101 static int rs_ioctl(struct tty_struct *tty,
1102 		    unsigned int cmd, unsigned long arg)
1103 {
1104 	struct serial_state *info = tty->driver_data;
1105 	struct async_icount cprev, cnow;	/* kernel counter temps */
1106 	void __user *argp = (void __user *)arg;
1107 	unsigned long flags;
1108 	DEFINE_WAIT(wait);
1109 	int ret;
1110 
1111 	if ((cmd != TIOCSERCONFIG) &&
1112 	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1113 		if (tty_io_error(tty))
1114 		    return -EIO;
1115 	}
1116 
1117 	switch (cmd) {
1118 		case TIOCSERCONFIG:
1119 			return 0;
1120 
1121 		case TIOCSERGETLSR: /* Get line status register */
1122 			return get_lsr_info(info, argp);
1123 
1124 		/*
1125 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1126 		 * - mask passed in arg for lines of interest
1127  		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1128 		 * Caller should use TIOCGICOUNT to see which one it was
1129 		 */
1130 		case TIOCMIWAIT:
1131 			local_irq_save(flags);
1132 			/* note the counters on entry */
1133 			cprev = info->icount;
1134 			local_irq_restore(flags);
1135 			while (1) {
1136 				prepare_to_wait(&info->tport.delta_msr_wait,
1137 						&wait, TASK_INTERRUPTIBLE);
1138 				local_irq_save(flags);
1139 				cnow = info->icount; /* atomic copy */
1140 				local_irq_restore(flags);
1141 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1142 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
1143 					ret = -EIO; /* no change => error */
1144 					break;
1145 				}
1146 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1147 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1148 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1149 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1150 					ret = 0;
1151 					break;
1152 				}
1153 				schedule();
1154 				/* see if a signal did it */
1155 				if (signal_pending(current)) {
1156 					ret = -ERESTARTSYS;
1157 					break;
1158 				}
1159 				cprev = cnow;
1160 			}
1161 			finish_wait(&info->tport.delta_msr_wait, &wait);
1162 			return ret;
1163 
1164 		default:
1165 			return -ENOIOCTLCMD;
1166 		}
1167 	return 0;
1168 }
1169 
rs_set_termios(struct tty_struct * tty,const struct ktermios * old_termios)1170 static void rs_set_termios(struct tty_struct *tty, const struct ktermios *old_termios)
1171 {
1172 	struct serial_state *info = tty->driver_data;
1173 	unsigned long flags;
1174 	unsigned int cflag = tty->termios.c_cflag;
1175 
1176 	change_speed(tty, info, old_termios);
1177 
1178 	/* Handle transition to B0 status */
1179 	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
1180 		info->MCR &= ~(SER_DTR|SER_RTS);
1181 		local_irq_save(flags);
1182 		rtsdtr_ctrl(info->MCR);
1183 		local_irq_restore(flags);
1184 	}
1185 
1186 	/* Handle transition away from B0 status */
1187 	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1188 		info->MCR |= SER_DTR;
1189 		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
1190 			info->MCR |= SER_RTS;
1191 		local_irq_save(flags);
1192 		rtsdtr_ctrl(info->MCR);
1193 		local_irq_restore(flags);
1194 	}
1195 
1196 	/* Handle turning off CRTSCTS */
1197 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1198 		tty->hw_stopped = false;
1199 		rs_start(tty);
1200 	}
1201 
1202 #if 0
1203 	/*
1204 	 * No need to wake up processes in open wait, since they
1205 	 * sample the CLOCAL flag once, and don't recheck it.
1206 	 * XXX  It's not clear whether the current behavior is correct
1207 	 * or not.  Hence, this may change.....
1208 	 */
1209 	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
1210 		wake_up_interruptible(&info->open_wait);
1211 #endif
1212 }
1213 
1214 /*
1215  * ------------------------------------------------------------
1216  * rs_close()
1217  *
1218  * This routine is called when the serial port gets closed.  First, we
1219  * wait for the last remaining data to be sent.  Then, we unlink its
1220  * async structure from the interrupt chain if necessary, and we free
1221  * that IRQ if nothing is left in the chain.
1222  * ------------------------------------------------------------
1223  */
rs_close(struct tty_struct * tty,struct file * filp)1224 static void rs_close(struct tty_struct *tty, struct file * filp)
1225 {
1226 	struct serial_state *state = tty->driver_data;
1227 	struct tty_port *port = &state->tport;
1228 
1229 	if (tty_port_close_start(port, tty, filp) == 0)
1230 		return;
1231 
1232 	/*
1233 	 * At this point we stop accepting input.  To do this, we
1234 	 * disable the receive line status interrupts, and tell the
1235 	 * interrupt driver to stop checking the data ready bit in the
1236 	 * line status register.
1237 	 */
1238 	state->read_status_mask &= ~UART_LSR_DR;
1239 	if (tty_port_initialized(port)) {
1240 	        /* disable receive interrupts */
1241 	        amiga_custom.intena = IF_RBF;
1242 		mb();
1243 		/* clear any pending receive interrupt */
1244 		amiga_custom.intreq = IF_RBF;
1245 		mb();
1246 
1247 		/*
1248 		 * Before we drop DTR, make sure the UART transmitter
1249 		 * has completely drained; this is especially
1250 		 * important if there is a transmit FIFO!
1251 		 */
1252 		rs_wait_until_sent(tty, state->timeout);
1253 	}
1254 	shutdown(tty, state);
1255 	rs_flush_buffer(tty);
1256 
1257 	tty_ldisc_flush(tty);
1258 	port->tty = NULL;
1259 
1260 	tty_port_close_end(port, tty);
1261 }
1262 
1263 /*
1264  * rs_wait_until_sent() --- wait until the transmitter is empty
1265  */
rs_wait_until_sent(struct tty_struct * tty,int timeout)1266 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1267 {
1268 	struct serial_state *info = tty->driver_data;
1269 	unsigned long orig_jiffies, char_time;
1270 	int lsr;
1271 
1272 	orig_jiffies = jiffies;
1273 
1274 	/*
1275 	 * Set the check interval to be 1/5 of the estimated time to
1276 	 * send a single character, and make it at least 1.  The check
1277 	 * interval should also be less than the timeout.
1278 	 *
1279 	 * Note: we have to use pretty tight timings here to satisfy
1280 	 * the NIST-PCTS.
1281 	 */
1282 	char_time = (info->timeout - HZ/50) / XMIT_FIFO_SIZE;
1283 	char_time = char_time / 5;
1284 	if (char_time == 0)
1285 		char_time = 1;
1286 	if (timeout)
1287 	  char_time = min_t(unsigned long, char_time, timeout);
1288 	/*
1289 	 * If the transmitter hasn't cleared in twice the approximate
1290 	 * amount of time to send the entire FIFO, it probably won't
1291 	 * ever clear.  This assumes the UART isn't doing flow
1292 	 * control, which is currently the case.  Hence, if it ever
1293 	 * takes longer than info->timeout, this is probably due to a
1294 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1295 	 * 2*info->timeout.
1296 	 */
1297 	if (!timeout || timeout > 2*info->timeout)
1298 		timeout = 2*info->timeout;
1299 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1300 	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1301 	printk("jiff=%lu...", jiffies);
1302 #endif
1303 	while(!((lsr = amiga_custom.serdatr) & SDR_TSRE)) {
1304 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1305 		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1306 #endif
1307 		msleep_interruptible(jiffies_to_msecs(char_time));
1308 		if (signal_pending(current))
1309 			break;
1310 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1311 			break;
1312 	}
1313 	__set_current_state(TASK_RUNNING);
1314 
1315 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1316 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1317 #endif
1318 }
1319 
1320 /*
1321  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1322  */
rs_hangup(struct tty_struct * tty)1323 static void rs_hangup(struct tty_struct *tty)
1324 {
1325 	struct serial_state *info = tty->driver_data;
1326 
1327 	rs_flush_buffer(tty);
1328 	shutdown(tty, info);
1329 	info->tport.count = 0;
1330 	tty_port_set_active(&info->tport, false);
1331 	info->tport.tty = NULL;
1332 	wake_up_interruptible(&info->tport.open_wait);
1333 }
1334 
1335 /*
1336  * This routine is called whenever a serial port is opened.  It
1337  * enables interrupts for a serial port, linking in its async structure into
1338  * the IRQ chain.   It also performs the serial-specific
1339  * initialization for the tty structure.
1340  */
rs_open(struct tty_struct * tty,struct file * filp)1341 static int rs_open(struct tty_struct *tty, struct file * filp)
1342 {
1343 	struct tty_port *port = tty->port;
1344 	struct serial_state *info = container_of(port, struct serial_state,
1345 			tport);
1346 	int retval;
1347 
1348 	port->count++;
1349 	port->tty = tty;
1350 	tty->driver_data = info;
1351 
1352 	retval = startup(tty, info);
1353 	if (retval) {
1354 		return retval;
1355 	}
1356 
1357 	return tty_port_block_til_ready(port, tty, filp);
1358 }
1359 
1360 /*
1361  * /proc fs routines....
1362  */
1363 
line_info(struct seq_file * m,int line,struct serial_state * state)1364 static inline void line_info(struct seq_file *m, int line,
1365 		struct serial_state *state)
1366 {
1367 	char	stat_buf[30], control, status;
1368 	unsigned long flags;
1369 
1370 	seq_printf(m, "%d: uart:amiga_builtin", line);
1371 
1372 	local_irq_save(flags);
1373 	status = ciab.pra;
1374 	control = tty_port_initialized(&state->tport) ? state->MCR : status;
1375 	local_irq_restore(flags);
1376 
1377 	stat_buf[0] = 0;
1378 	stat_buf[1] = 0;
1379 	if(!(control & SER_RTS))
1380 		strcat(stat_buf, "|RTS");
1381 	if(!(status & SER_CTS))
1382 		strcat(stat_buf, "|CTS");
1383 	if(!(control & SER_DTR))
1384 		strcat(stat_buf, "|DTR");
1385 	if(!(status & SER_DSR))
1386 		strcat(stat_buf, "|DSR");
1387 	if(!(status & SER_DCD))
1388 		strcat(stat_buf, "|CD");
1389 
1390 	if (state->quot)
1391 		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1392 
1393 	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1394 
1395 	if (state->icount.frame)
1396 		seq_printf(m, " fe:%d", state->icount.frame);
1397 
1398 	if (state->icount.parity)
1399 		seq_printf(m, " pe:%d", state->icount.parity);
1400 
1401 	if (state->icount.brk)
1402 		seq_printf(m, " brk:%d", state->icount.brk);
1403 
1404 	if (state->icount.overrun)
1405 		seq_printf(m, " oe:%d", state->icount.overrun);
1406 
1407 	/*
1408 	 * Last thing is the RS-232 status lines
1409 	 */
1410 	seq_printf(m, " %s\n", stat_buf+1);
1411 }
1412 
rs_proc_show(struct seq_file * m,void * v)1413 static int rs_proc_show(struct seq_file *m, void *v)
1414 {
1415 	seq_printf(m, "serinfo:1.0 driver:4.30\n");
1416 	line_info(m, 0, &serial_state);
1417 	return 0;
1418 }
1419 
1420 /*
1421  * ---------------------------------------------------------------------
1422  * rs_init() and friends
1423  *
1424  * rs_init() is called at boot-time to initialize the serial driver.
1425  * ---------------------------------------------------------------------
1426  */
1427 
1428 static const struct tty_operations serial_ops = {
1429 	.open = rs_open,
1430 	.close = rs_close,
1431 	.write = rs_write,
1432 	.put_char = rs_put_char,
1433 	.flush_chars = rs_flush_chars,
1434 	.write_room = rs_write_room,
1435 	.chars_in_buffer = rs_chars_in_buffer,
1436 	.flush_buffer = rs_flush_buffer,
1437 	.ioctl = rs_ioctl,
1438 	.throttle = rs_throttle,
1439 	.unthrottle = rs_unthrottle,
1440 	.set_termios = rs_set_termios,
1441 	.stop = rs_stop,
1442 	.start = rs_start,
1443 	.hangup = rs_hangup,
1444 	.break_ctl = rs_break,
1445 	.send_xchar = rs_send_xchar,
1446 	.wait_until_sent = rs_wait_until_sent,
1447 	.tiocmget = rs_tiocmget,
1448 	.tiocmset = rs_tiocmset,
1449 	.get_icount = rs_get_icount,
1450 	.set_serial = set_serial_info,
1451 	.get_serial = get_serial_info,
1452 	.proc_show = rs_proc_show,
1453 };
1454 
amiga_carrier_raised(struct tty_port * port)1455 static bool amiga_carrier_raised(struct tty_port *port)
1456 {
1457 	return !(ciab.pra & SER_DCD);
1458 }
1459 
amiga_dtr_rts(struct tty_port * port,bool active)1460 static void amiga_dtr_rts(struct tty_port *port, bool active)
1461 {
1462 	struct serial_state *info = container_of(port, struct serial_state,
1463 			tport);
1464 	unsigned long flags;
1465 
1466 	if (active)
1467 		info->MCR |= SER_DTR|SER_RTS;
1468 	else
1469 		info->MCR &= ~(SER_DTR|SER_RTS);
1470 
1471 	local_irq_save(flags);
1472 	rtsdtr_ctrl(info->MCR);
1473 	local_irq_restore(flags);
1474 }
1475 
1476 static const struct tty_port_operations amiga_port_ops = {
1477 	.carrier_raised = amiga_carrier_raised,
1478 	.dtr_rts = amiga_dtr_rts,
1479 };
1480 
1481 /*
1482  * The serial driver boot-time initialization code!
1483  */
amiga_serial_probe(struct platform_device * pdev)1484 static int __init amiga_serial_probe(struct platform_device *pdev)
1485 {
1486 	struct serial_state *state = &serial_state;
1487 	struct tty_driver *driver;
1488 	unsigned long flags;
1489 	int error;
1490 
1491 	driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
1492 	if (IS_ERR(driver))
1493 		return PTR_ERR(driver);
1494 
1495 	/* Initialize the tty_driver structure */
1496 
1497 	driver->driver_name = "amiserial";
1498 	driver->name = "ttyS";
1499 	driver->major = TTY_MAJOR;
1500 	driver->minor_start = 64;
1501 	driver->type = TTY_DRIVER_TYPE_SERIAL;
1502 	driver->subtype = SERIAL_TYPE_NORMAL;
1503 	driver->init_termios = tty_std_termios;
1504 	driver->init_termios.c_cflag =
1505 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1506 	tty_set_operations(driver, &serial_ops);
1507 
1508 	memset(state, 0, sizeof(*state));
1509 	state->port = (int)&amiga_custom.serdatr; /* Just to give it a value */
1510 	tty_port_init(&state->tport);
1511 	state->tport.ops = &amiga_port_ops;
1512 	tty_port_link_device(&state->tport, driver, 0);
1513 
1514 	error = tty_register_driver(driver);
1515 	if (error)
1516 		goto fail_tty_driver_kref_put;
1517 
1518 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1519 
1520 	/* Hardware set up */
1521 
1522 	state->baud_base = amiga_colorclock;
1523 
1524 	/* set ISRs, and then disable the rx interrupts */
1525 	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1526 	if (error)
1527 		goto fail_unregister;
1528 
1529 	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1530 			    "serial RX", state);
1531 	if (error)
1532 		goto fail_free_irq;
1533 
1534 	local_irq_save(flags);
1535 
1536 	/* turn off Rx and Tx interrupts */
1537 	amiga_custom.intena = IF_RBF | IF_TBE;
1538 	mb();
1539 
1540 	/* clear any pending interrupt */
1541 	amiga_custom.intreq = IF_RBF | IF_TBE;
1542 	mb();
1543 
1544 	local_irq_restore(flags);
1545 
1546 	/*
1547 	 * set the appropriate directions for the modem control flags,
1548 	 * and clear RTS and DTR
1549 	 */
1550 	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1551 	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1552 
1553 	platform_set_drvdata(pdev, state);
1554 
1555 	serial_driver = driver;
1556 
1557 	return 0;
1558 
1559 fail_free_irq:
1560 	free_irq(IRQ_AMIGA_TBE, state);
1561 fail_unregister:
1562 	tty_unregister_driver(driver);
1563 fail_tty_driver_kref_put:
1564 	tty_port_destroy(&state->tport);
1565 	tty_driver_kref_put(driver);
1566 	return error;
1567 }
1568 
amiga_serial_remove(struct platform_device * pdev)1569 static void __exit amiga_serial_remove(struct platform_device *pdev)
1570 {
1571 	struct serial_state *state = platform_get_drvdata(pdev);
1572 
1573 	tty_unregister_driver(serial_driver);
1574 	tty_driver_kref_put(serial_driver);
1575 	tty_port_destroy(&state->tport);
1576 
1577 	free_irq(IRQ_AMIGA_TBE, state);
1578 	free_irq(IRQ_AMIGA_RBF, state);
1579 }
1580 
1581 /*
1582  * amiga_serial_remove() lives in .exit.text. For drivers registered via
1583  * module_platform_driver_probe() this is ok because they cannot get unbound at
1584  * runtime. So mark the driver struct with __refdata to prevent modpost
1585  * triggering a section mismatch warning.
1586  */
1587 static struct platform_driver amiga_serial_driver __refdata = {
1588 	.remove = __exit_p(amiga_serial_remove),
1589 	.driver   = {
1590 		.name	= "amiga-serial",
1591 	},
1592 };
1593 
1594 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1595 
1596 
1597 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1598 
1599 /*
1600  * ------------------------------------------------------------
1601  * Serial console driver
1602  * ------------------------------------------------------------
1603  */
1604 
amiga_serial_putc(char c)1605 static void amiga_serial_putc(char c)
1606 {
1607 	amiga_custom.serdat = (unsigned char)c | 0x100;
1608 	while (!(amiga_custom.serdatr & 0x2000))
1609 		barrier();
1610 }
1611 
1612 /*
1613  *	Print a string to the serial port trying not to disturb
1614  *	any possible real use of the port...
1615  *
1616  *	The console must be locked when we get here.
1617  */
serial_console_write(struct console * co,const char * s,unsigned count)1618 static void serial_console_write(struct console *co, const char *s,
1619 				unsigned count)
1620 {
1621 	unsigned short intena = amiga_custom.intenar;
1622 
1623 	amiga_custom.intena = IF_TBE;
1624 
1625 	while (count--) {
1626 		if (*s == '\n')
1627 			amiga_serial_putc('\r');
1628 		amiga_serial_putc(*s++);
1629 	}
1630 
1631 	amiga_custom.intena = IF_SETCLR | (intena & IF_TBE);
1632 }
1633 
serial_console_device(struct console * c,int * index)1634 static struct tty_driver *serial_console_device(struct console *c, int *index)
1635 {
1636 	*index = 0;
1637 	return serial_driver;
1638 }
1639 
1640 static struct console sercons = {
1641 	.name =		"ttyS",
1642 	.write =	serial_console_write,
1643 	.device =	serial_console_device,
1644 	.flags =	CON_PRINTBUFFER,
1645 	.index =	-1,
1646 };
1647 
1648 /*
1649  *	Register console.
1650  */
amiserial_console_init(void)1651 static int __init amiserial_console_init(void)
1652 {
1653 	if (!MACH_IS_AMIGA)
1654 		return -ENODEV;
1655 
1656 	register_console(&sercons);
1657 	return 0;
1658 }
1659 console_initcall(amiserial_console_init);
1660 
1661 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1662 
1663 MODULE_DESCRIPTION("Serial driver for the amiga builtin port");
1664 MODULE_LICENSE("GPL");
1665 MODULE_ALIAS("platform:amiga-serial");
1666