xref: /openbmc/linux/drivers/tty/serial/mcf.c (revision 8dd3cdea) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /****************************************************************************/
3 
4 /*
5  *	mcf.c -- Freescale ColdFire UART driver
6  *
7  *	(C) Copyright 2003-2007, Greg Ungerer <gerg@uclinux.org>
8  */
9 
10 /****************************************************************************/
11 
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/console.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/serial.h>
20 #include <linux/serial_core.h>
21 #include <linux/io.h>
22 #include <linux/uaccess.h>
23 #include <linux/platform_device.h>
24 #include <asm/coldfire.h>
25 #include <asm/mcfsim.h>
26 #include <asm/mcfuart.h>
27 #include <asm/nettel.h>
28 
29 /****************************************************************************/
30 
31 /*
32  *	Some boards implement the DTR/DCD lines using GPIO lines, most
33  *	don't. Dummy out the access macros for those that don't. Those
34  *	that do should define these macros somewhere in there board
35  *	specific inlude files.
36  */
37 #if !defined(mcf_getppdcd)
38 #define	mcf_getppdcd(p)		(1)
39 #endif
40 #if !defined(mcf_getppdtr)
41 #define	mcf_getppdtr(p)		(1)
42 #endif
43 #if !defined(mcf_setppdtr)
44 #define	mcf_setppdtr(p, v)	do { } while (0)
45 #endif
46 
47 /****************************************************************************/
48 
49 /*
50  *	Local per-uart structure.
51  */
52 struct mcf_uart {
53 	struct uart_port	port;
54 	unsigned int		sigs;		/* Local copy of line sigs */
55 	unsigned char		imr;		/* Local IMR mirror */
56 };
57 
58 /****************************************************************************/
59 
60 static unsigned int mcf_tx_empty(struct uart_port *port)
61 {
62 	return (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXEMPTY) ?
63 		TIOCSER_TEMT : 0;
64 }
65 
66 /****************************************************************************/
67 
68 static unsigned int mcf_get_mctrl(struct uart_port *port)
69 {
70 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
71 	unsigned int sigs;
72 
73 	sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
74 		0 : TIOCM_CTS;
75 	sigs |= (pp->sigs & TIOCM_RTS);
76 	sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
77 	sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
78 
79 	return sigs;
80 }
81 
82 /****************************************************************************/
83 
84 static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
85 {
86 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
87 
88 	pp->sigs = sigs;
89 	mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
90 	if (sigs & TIOCM_RTS)
91 		writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
92 	else
93 		writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
94 }
95 
96 /****************************************************************************/
97 
98 static void mcf_start_tx(struct uart_port *port)
99 {
100 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
101 
102 	if (port->rs485.flags & SER_RS485_ENABLED) {
103 		/* Enable Transmitter */
104 		writeb(MCFUART_UCR_TXENABLE, port->membase + MCFUART_UCR);
105 		/* Manually assert RTS */
106 		writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
107 	}
108 	pp->imr |= MCFUART_UIR_TXREADY;
109 	writeb(pp->imr, port->membase + MCFUART_UIMR);
110 }
111 
112 /****************************************************************************/
113 
114 static void mcf_stop_tx(struct uart_port *port)
115 {
116 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
117 
118 	pp->imr &= ~MCFUART_UIR_TXREADY;
119 	writeb(pp->imr, port->membase + MCFUART_UIMR);
120 }
121 
122 /****************************************************************************/
123 
124 static void mcf_stop_rx(struct uart_port *port)
125 {
126 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
127 
128 	pp->imr &= ~MCFUART_UIR_RXREADY;
129 	writeb(pp->imr, port->membase + MCFUART_UIMR);
130 }
131 
132 /****************************************************************************/
133 
134 static void mcf_break_ctl(struct uart_port *port, int break_state)
135 {
136 	unsigned long flags;
137 
138 	spin_lock_irqsave(&port->lock, flags);
139 	if (break_state == -1)
140 		writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
141 	else
142 		writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
143 	spin_unlock_irqrestore(&port->lock, flags);
144 }
145 
146 /****************************************************************************/
147 
148 static int mcf_startup(struct uart_port *port)
149 {
150 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
151 	unsigned long flags;
152 
153 	spin_lock_irqsave(&port->lock, flags);
154 
155 	/* Reset UART, get it into known state... */
156 	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
157 	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
158 
159 	/* Enable the UART transmitter and receiver */
160 	writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
161 		port->membase + MCFUART_UCR);
162 
163 	/* Enable RX interrupts now */
164 	pp->imr = MCFUART_UIR_RXREADY;
165 	writeb(pp->imr, port->membase + MCFUART_UIMR);
166 
167 	spin_unlock_irqrestore(&port->lock, flags);
168 
169 	return 0;
170 }
171 
172 /****************************************************************************/
173 
174 static void mcf_shutdown(struct uart_port *port)
175 {
176 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
177 	unsigned long flags;
178 
179 	spin_lock_irqsave(&port->lock, flags);
180 
181 	/* Disable all interrupts now */
182 	pp->imr = 0;
183 	writeb(pp->imr, port->membase + MCFUART_UIMR);
184 
185 	/* Disable UART transmitter and receiver */
186 	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
187 	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
188 
189 	spin_unlock_irqrestore(&port->lock, flags);
190 }
191 
192 /****************************************************************************/
193 
194 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
195 	struct ktermios *old)
196 {
197 	unsigned long flags;
198 	unsigned int baud, baudclk;
199 #if defined(CONFIG_M5272)
200 	unsigned int baudfr;
201 #endif
202 	unsigned char mr1, mr2;
203 
204 	baud = uart_get_baud_rate(port, termios, old, 0, 230400);
205 #if defined(CONFIG_M5272)
206 	baudclk = (MCF_BUSCLK / baud) / 32;
207 	baudfr = (((MCF_BUSCLK / baud) + 1) / 2) % 16;
208 #else
209 	baudclk = ((MCF_BUSCLK / baud) + 16) / 32;
210 #endif
211 
212 	mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
213 	mr2 = 0;
214 
215 	switch (termios->c_cflag & CSIZE) {
216 	case CS5: mr1 |= MCFUART_MR1_CS5; break;
217 	case CS6: mr1 |= MCFUART_MR1_CS6; break;
218 	case CS7: mr1 |= MCFUART_MR1_CS7; break;
219 	case CS8:
220 	default:  mr1 |= MCFUART_MR1_CS8; break;
221 	}
222 
223 	if (termios->c_cflag & PARENB) {
224 		if (termios->c_cflag & CMSPAR) {
225 			if (termios->c_cflag & PARODD)
226 				mr1 |= MCFUART_MR1_PARITYMARK;
227 			else
228 				mr1 |= MCFUART_MR1_PARITYSPACE;
229 		} else {
230 			if (termios->c_cflag & PARODD)
231 				mr1 |= MCFUART_MR1_PARITYODD;
232 			else
233 				mr1 |= MCFUART_MR1_PARITYEVEN;
234 		}
235 	} else {
236 		mr1 |= MCFUART_MR1_PARITYNONE;
237 	}
238 
239 	/*
240 	 * FIXME: port->read_status_mask and port->ignore_status_mask
241 	 * need to be initialized based on termios settings for
242 	 * INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
243 	 */
244 
245 	if (termios->c_cflag & CSTOPB)
246 		mr2 |= MCFUART_MR2_STOP2;
247 	else
248 		mr2 |= MCFUART_MR2_STOP1;
249 
250 	if (termios->c_cflag & CRTSCTS) {
251 		mr1 |= MCFUART_MR1_RXRTS;
252 		mr2 |= MCFUART_MR2_TXCTS;
253 	}
254 
255 	spin_lock_irqsave(&port->lock, flags);
256 	if (port->rs485.flags & SER_RS485_ENABLED) {
257 		dev_dbg(port->dev, "Setting UART to RS485\n");
258 		mr2 |= MCFUART_MR2_TXRTS;
259 	}
260 
261 	uart_update_timeout(port, termios->c_cflag, baud);
262 	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
263 	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
264 	writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
265 	writeb(mr1, port->membase + MCFUART_UMR);
266 	writeb(mr2, port->membase + MCFUART_UMR);
267 	writeb((baudclk & 0xff00) >> 8, port->membase + MCFUART_UBG1);
268 	writeb((baudclk & 0xff), port->membase + MCFUART_UBG2);
269 #if defined(CONFIG_M5272)
270 	writeb((baudfr & 0x0f), port->membase + MCFUART_UFPD);
271 #endif
272 	writeb(MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER,
273 		port->membase + MCFUART_UCSR);
274 	writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
275 		port->membase + MCFUART_UCR);
276 	spin_unlock_irqrestore(&port->lock, flags);
277 }
278 
279 /****************************************************************************/
280 
281 static void mcf_rx_chars(struct mcf_uart *pp)
282 {
283 	struct uart_port *port = &pp->port;
284 	unsigned char status, ch, flag;
285 
286 	while ((status = readb(port->membase + MCFUART_USR)) & MCFUART_USR_RXREADY) {
287 		ch = readb(port->membase + MCFUART_URB);
288 		flag = TTY_NORMAL;
289 		port->icount.rx++;
290 
291 		if (status & MCFUART_USR_RXERR) {
292 			writeb(MCFUART_UCR_CMDRESETERR,
293 				port->membase + MCFUART_UCR);
294 
295 			if (status & MCFUART_USR_RXBREAK) {
296 				port->icount.brk++;
297 				if (uart_handle_break(port))
298 					continue;
299 			} else if (status & MCFUART_USR_RXPARITY) {
300 				port->icount.parity++;
301 			} else if (status & MCFUART_USR_RXOVERRUN) {
302 				port->icount.overrun++;
303 			} else if (status & MCFUART_USR_RXFRAMING) {
304 				port->icount.frame++;
305 			}
306 
307 			status &= port->read_status_mask;
308 
309 			if (status & MCFUART_USR_RXBREAK)
310 				flag = TTY_BREAK;
311 			else if (status & MCFUART_USR_RXPARITY)
312 				flag = TTY_PARITY;
313 			else if (status & MCFUART_USR_RXFRAMING)
314 				flag = TTY_FRAME;
315 		}
316 
317 		if (uart_handle_sysrq_char(port, ch))
318 			continue;
319 		uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
320 	}
321 
322 	tty_flip_buffer_push(&port->state->port);
323 }
324 
325 /****************************************************************************/
326 
327 static void mcf_tx_chars(struct mcf_uart *pp)
328 {
329 	struct uart_port *port = &pp->port;
330 	struct circ_buf *xmit = &port->state->xmit;
331 
332 	if (port->x_char) {
333 		/* Send special char - probably flow control */
334 		writeb(port->x_char, port->membase + MCFUART_UTB);
335 		port->x_char = 0;
336 		port->icount.tx++;
337 		return;
338 	}
339 
340 	while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
341 		if (uart_circ_empty(xmit))
342 			break;
343 		writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
344 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
345 		port->icount.tx++;
346 	}
347 
348 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
349 		uart_write_wakeup(port);
350 
351 	if (uart_circ_empty(xmit)) {
352 		mcf_stop_tx(port);
353 		/* Disable TX to negate RTS automatically */
354 		if (port->rs485.flags & SER_RS485_ENABLED)
355 			writeb(MCFUART_UCR_TXDISABLE,
356 				port->membase + MCFUART_UCR);
357 	}
358 }
359 
360 /****************************************************************************/
361 
362 static irqreturn_t mcf_interrupt(int irq, void *data)
363 {
364 	struct uart_port *port = data;
365 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
366 	unsigned int isr;
367 	irqreturn_t ret = IRQ_NONE;
368 
369 	isr = readb(port->membase + MCFUART_UISR) & pp->imr;
370 
371 	spin_lock(&port->lock);
372 	if (isr & MCFUART_UIR_RXREADY) {
373 		mcf_rx_chars(pp);
374 		ret = IRQ_HANDLED;
375 	}
376 	if (isr & MCFUART_UIR_TXREADY) {
377 		mcf_tx_chars(pp);
378 		ret = IRQ_HANDLED;
379 	}
380 	spin_unlock(&port->lock);
381 
382 	return ret;
383 }
384 
385 /****************************************************************************/
386 
387 static void mcf_config_port(struct uart_port *port, int flags)
388 {
389 	port->type = PORT_MCF;
390 	port->fifosize = MCFUART_TXFIFOSIZE;
391 
392 	/* Clear mask, so no surprise interrupts. */
393 	writeb(0, port->membase + MCFUART_UIMR);
394 
395 	if (request_irq(port->irq, mcf_interrupt, 0, "UART", port))
396 		printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
397 			"interrupt vector=%d\n", port->line, port->irq);
398 }
399 
400 /****************************************************************************/
401 
402 static const char *mcf_type(struct uart_port *port)
403 {
404 	return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
405 }
406 
407 /****************************************************************************/
408 
409 static int mcf_request_port(struct uart_port *port)
410 {
411 	/* UARTs always present */
412 	return 0;
413 }
414 
415 /****************************************************************************/
416 
417 static void mcf_release_port(struct uart_port *port)
418 {
419 	/* Nothing to release... */
420 }
421 
422 /****************************************************************************/
423 
424 static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
425 {
426 	if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
427 		return -EINVAL;
428 	return 0;
429 }
430 
431 /****************************************************************************/
432 
433 /* Enable or disable the RS485 support */
434 static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
435 {
436 	unsigned char mr1, mr2;
437 
438 	/* Get mode registers */
439 	mr1 = readb(port->membase + MCFUART_UMR);
440 	mr2 = readb(port->membase + MCFUART_UMR);
441 	if (rs485->flags & SER_RS485_ENABLED) {
442 		dev_dbg(port->dev, "Setting UART to RS485\n");
443 		/* Automatically negate RTS after TX completes */
444 		mr2 |= MCFUART_MR2_TXRTS;
445 	} else {
446 		dev_dbg(port->dev, "Setting UART to RS232\n");
447 		mr2 &= ~MCFUART_MR2_TXRTS;
448 	}
449 	writeb(mr1, port->membase + MCFUART_UMR);
450 	writeb(mr2, port->membase + MCFUART_UMR);
451 	port->rs485 = *rs485;
452 
453 	return 0;
454 }
455 
456 /****************************************************************************/
457 
458 /*
459  *	Define the basic serial functions we support.
460  */
461 static const struct uart_ops mcf_uart_ops = {
462 	.tx_empty	= mcf_tx_empty,
463 	.get_mctrl	= mcf_get_mctrl,
464 	.set_mctrl	= mcf_set_mctrl,
465 	.start_tx	= mcf_start_tx,
466 	.stop_tx	= mcf_stop_tx,
467 	.stop_rx	= mcf_stop_rx,
468 	.break_ctl	= mcf_break_ctl,
469 	.startup	= mcf_startup,
470 	.shutdown	= mcf_shutdown,
471 	.set_termios	= mcf_set_termios,
472 	.type		= mcf_type,
473 	.request_port	= mcf_request_port,
474 	.release_port	= mcf_release_port,
475 	.config_port	= mcf_config_port,
476 	.verify_port	= mcf_verify_port,
477 };
478 
479 static struct mcf_uart mcf_ports[4];
480 
481 #define	MCF_MAXPORTS	ARRAY_SIZE(mcf_ports)
482 
483 /****************************************************************************/
484 #if defined(CONFIG_SERIAL_MCF_CONSOLE)
485 /****************************************************************************/
486 
487 int __init early_mcf_setup(struct mcf_platform_uart *platp)
488 {
489 	struct uart_port *port;
490 	int i;
491 
492 	for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
493 		port = &mcf_ports[i].port;
494 
495 		port->line = i;
496 		port->type = PORT_MCF;
497 		port->mapbase = platp[i].mapbase;
498 		port->membase = (platp[i].membase) ? platp[i].membase :
499 			(unsigned char __iomem *) port->mapbase;
500 		port->iotype = SERIAL_IO_MEM;
501 		port->irq = platp[i].irq;
502 		port->uartclk = MCF_BUSCLK;
503 		port->flags = UPF_BOOT_AUTOCONF;
504 		port->rs485_config = mcf_config_rs485;
505 		port->ops = &mcf_uart_ops;
506 	}
507 
508 	return 0;
509 }
510 
511 /****************************************************************************/
512 
513 static void mcf_console_putc(struct console *co, const char c)
514 {
515 	struct uart_port *port = &(mcf_ports + co->index)->port;
516 	int i;
517 
518 	for (i = 0; (i < 0x10000); i++) {
519 		if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
520 			break;
521 	}
522 	writeb(c, port->membase + MCFUART_UTB);
523 	for (i = 0; (i < 0x10000); i++) {
524 		if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
525 			break;
526 	}
527 }
528 
529 /****************************************************************************/
530 
531 static void mcf_console_write(struct console *co, const char *s, unsigned int count)
532 {
533 	for (; (count); count--, s++) {
534 		mcf_console_putc(co, *s);
535 		if (*s == '\n')
536 			mcf_console_putc(co, '\r');
537 	}
538 }
539 
540 /****************************************************************************/
541 
542 static int __init mcf_console_setup(struct console *co, char *options)
543 {
544 	struct uart_port *port;
545 	int baud = CONFIG_SERIAL_MCF_BAUDRATE;
546 	int bits = 8;
547 	int parity = 'n';
548 	int flow = 'n';
549 
550 	if ((co->index < 0) || (co->index >= MCF_MAXPORTS))
551 		co->index = 0;
552 	port = &mcf_ports[co->index].port;
553 	if (port->membase == 0)
554 		return -ENODEV;
555 
556 	if (options)
557 		uart_parse_options(options, &baud, &parity, &bits, &flow);
558 
559 	return uart_set_options(port, co, baud, parity, bits, flow);
560 }
561 
562 /****************************************************************************/
563 
564 static struct uart_driver mcf_driver;
565 
566 static struct console mcf_console = {
567 	.name		= "ttyS",
568 	.write		= mcf_console_write,
569 	.device		= uart_console_device,
570 	.setup		= mcf_console_setup,
571 	.flags		= CON_PRINTBUFFER,
572 	.index		= -1,
573 	.data		= &mcf_driver,
574 };
575 
576 static int __init mcf_console_init(void)
577 {
578 	register_console(&mcf_console);
579 	return 0;
580 }
581 
582 console_initcall(mcf_console_init);
583 
584 #define	MCF_CONSOLE	&mcf_console
585 
586 /****************************************************************************/
587 #else
588 /****************************************************************************/
589 
590 #define	MCF_CONSOLE	NULL
591 
592 /****************************************************************************/
593 #endif /* CONFIG_SERIAL_MCF_CONSOLE */
594 /****************************************************************************/
595 
596 /*
597  *	Define the mcf UART driver structure.
598  */
599 static struct uart_driver mcf_driver = {
600 	.owner		= THIS_MODULE,
601 	.driver_name	= "mcf",
602 	.dev_name	= "ttyS",
603 	.major		= TTY_MAJOR,
604 	.minor		= 64,
605 	.nr		= MCF_MAXPORTS,
606 	.cons		= MCF_CONSOLE,
607 };
608 
609 /****************************************************************************/
610 
611 static int mcf_probe(struct platform_device *pdev)
612 {
613 	struct mcf_platform_uart *platp = dev_get_platdata(&pdev->dev);
614 	struct uart_port *port;
615 	int i;
616 
617 	for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
618 		port = &mcf_ports[i].port;
619 
620 		port->line = i;
621 		port->type = PORT_MCF;
622 		port->mapbase = platp[i].mapbase;
623 		port->membase = (platp[i].membase) ? platp[i].membase :
624 			(unsigned char __iomem *) platp[i].mapbase;
625 		port->dev = &pdev->dev;
626 		port->iotype = SERIAL_IO_MEM;
627 		port->irq = platp[i].irq;
628 		port->uartclk = MCF_BUSCLK;
629 		port->ops = &mcf_uart_ops;
630 		port->flags = UPF_BOOT_AUTOCONF;
631 		port->rs485_config = mcf_config_rs485;
632 		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MCF_CONSOLE);
633 
634 		uart_add_one_port(&mcf_driver, port);
635 	}
636 
637 	return 0;
638 }
639 
640 /****************************************************************************/
641 
642 static int mcf_remove(struct platform_device *pdev)
643 {
644 	struct uart_port *port;
645 	int i;
646 
647 	for (i = 0; (i < MCF_MAXPORTS); i++) {
648 		port = &mcf_ports[i].port;
649 		if (port)
650 			uart_remove_one_port(&mcf_driver, port);
651 	}
652 
653 	return 0;
654 }
655 
656 /****************************************************************************/
657 
658 static struct platform_driver mcf_platform_driver = {
659 	.probe		= mcf_probe,
660 	.remove		= mcf_remove,
661 	.driver		= {
662 		.name	= "mcfuart",
663 	},
664 };
665 
666 /****************************************************************************/
667 
668 static int __init mcf_init(void)
669 {
670 	int rc;
671 
672 	printk("ColdFire internal UART serial driver\n");
673 
674 	rc = uart_register_driver(&mcf_driver);
675 	if (rc)
676 		return rc;
677 	rc = platform_driver_register(&mcf_platform_driver);
678 	if (rc) {
679 		uart_unregister_driver(&mcf_driver);
680 		return rc;
681 	}
682 	return 0;
683 }
684 
685 /****************************************************************************/
686 
687 static void __exit mcf_exit(void)
688 {
689 	platform_driver_unregister(&mcf_platform_driver);
690 	uart_unregister_driver(&mcf_driver);
691 }
692 
693 /****************************************************************************/
694 
695 module_init(mcf_init);
696 module_exit(mcf_exit);
697 
698 MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
699 MODULE_DESCRIPTION("Freescale ColdFire UART driver");
700 MODULE_LICENSE("GPL");
701 MODULE_ALIAS("platform:mcfuart");
702 
703 /****************************************************************************/
704