xref: /openbmc/linux/drivers/tty/serial/lantiq.c (revision 81d67439)
1 /*
2  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 as published
6  * by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
16  *
17  * Copyright (C) 2004 Infineon IFAP DC COM CPE
18  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
19  * Copyright (C) 2007 John Crispin <blogic@openwrt.org>
20  * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/sysrq.h>
29 #include <linux/device.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial_core.h>
33 #include <linux/serial.h>
34 #include <linux/platform_device.h>
35 #include <linux/io.h>
36 #include <linux/clk.h>
37 
38 #include <lantiq_soc.h>
39 
40 #define PORT_LTQ_ASC		111
41 #define MAXPORTS		2
42 #define UART_DUMMY_UER_RX	1
43 #define DRVNAME			"ltq_asc"
44 #ifdef __BIG_ENDIAN
45 #define LTQ_ASC_TBUF		(0x0020 + 3)
46 #define LTQ_ASC_RBUF		(0x0024 + 3)
47 #else
48 #define LTQ_ASC_TBUF		0x0020
49 #define LTQ_ASC_RBUF		0x0024
50 #endif
51 #define LTQ_ASC_FSTAT		0x0048
52 #define LTQ_ASC_WHBSTATE	0x0018
53 #define LTQ_ASC_STATE		0x0014
54 #define LTQ_ASC_IRNCR		0x00F8
55 #define LTQ_ASC_CLC		0x0000
56 #define LTQ_ASC_ID		0x0008
57 #define LTQ_ASC_PISEL		0x0004
58 #define LTQ_ASC_TXFCON		0x0044
59 #define LTQ_ASC_RXFCON		0x0040
60 #define LTQ_ASC_CON		0x0010
61 #define LTQ_ASC_BG		0x0050
62 #define LTQ_ASC_IRNREN		0x00F4
63 
64 #define ASC_IRNREN_TX		0x1
65 #define ASC_IRNREN_RX		0x2
66 #define ASC_IRNREN_ERR		0x4
67 #define ASC_IRNREN_TX_BUF	0x8
68 #define ASC_IRNCR_TIR		0x1
69 #define ASC_IRNCR_RIR		0x2
70 #define ASC_IRNCR_EIR		0x4
71 
72 #define ASCOPT_CSIZE		0x3
73 #define TXFIFO_FL		1
74 #define RXFIFO_FL		1
75 #define ASCCLC_DISS		0x2
76 #define ASCCLC_RMCMASK		0x0000FF00
77 #define ASCCLC_RMCOFFSET	8
78 #define ASCCON_M_8ASYNC		0x0
79 #define ASCCON_M_7ASYNC		0x2
80 #define ASCCON_ODD		0x00000020
81 #define ASCCON_STP		0x00000080
82 #define ASCCON_BRS		0x00000100
83 #define ASCCON_FDE		0x00000200
84 #define ASCCON_R		0x00008000
85 #define ASCCON_FEN		0x00020000
86 #define ASCCON_ROEN		0x00080000
87 #define ASCCON_TOEN		0x00100000
88 #define ASCSTATE_PE		0x00010000
89 #define ASCSTATE_FE		0x00020000
90 #define ASCSTATE_ROE		0x00080000
91 #define ASCSTATE_ANY		(ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
92 #define ASCWHBSTATE_CLRREN	0x00000001
93 #define ASCWHBSTATE_SETREN	0x00000002
94 #define ASCWHBSTATE_CLRPE	0x00000004
95 #define ASCWHBSTATE_CLRFE	0x00000008
96 #define ASCWHBSTATE_CLRROE	0x00000020
97 #define ASCTXFCON_TXFEN		0x0001
98 #define ASCTXFCON_TXFFLU	0x0002
99 #define ASCTXFCON_TXFITLMASK	0x3F00
100 #define ASCTXFCON_TXFITLOFF	8
101 #define ASCRXFCON_RXFEN		0x0001
102 #define ASCRXFCON_RXFFLU	0x0002
103 #define ASCRXFCON_RXFITLMASK	0x3F00
104 #define ASCRXFCON_RXFITLOFF	8
105 #define ASCFSTAT_RXFFLMASK	0x003F
106 #define ASCFSTAT_TXFFLMASK	0x3F00
107 #define ASCFSTAT_TXFREEMASK	0x3F000000
108 #define ASCFSTAT_TXFREEOFF	24
109 
110 static void lqasc_tx_chars(struct uart_port *port);
111 static struct ltq_uart_port *lqasc_port[MAXPORTS];
112 static struct uart_driver lqasc_reg;
113 static DEFINE_SPINLOCK(ltq_asc_lock);
114 
115 struct ltq_uart_port {
116 	struct uart_port	port;
117 	struct clk		*clk;
118 	unsigned int		tx_irq;
119 	unsigned int		rx_irq;
120 	unsigned int		err_irq;
121 };
122 
123 static inline struct
124 ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
125 {
126 	return container_of(port, struct ltq_uart_port, port);
127 }
128 
129 static void
130 lqasc_stop_tx(struct uart_port *port)
131 {
132 	return;
133 }
134 
135 static void
136 lqasc_start_tx(struct uart_port *port)
137 {
138 	unsigned long flags;
139 	spin_lock_irqsave(&ltq_asc_lock, flags);
140 	lqasc_tx_chars(port);
141 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
142 	return;
143 }
144 
145 static void
146 lqasc_stop_rx(struct uart_port *port)
147 {
148 	ltq_w32(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
149 }
150 
151 static void
152 lqasc_enable_ms(struct uart_port *port)
153 {
154 }
155 
156 static int
157 lqasc_rx_chars(struct uart_port *port)
158 {
159 	struct tty_struct *tty = tty_port_tty_get(&port->state->port);
160 	unsigned int ch = 0, rsr = 0, fifocnt;
161 
162 	if (!tty) {
163 		dev_dbg(port->dev, "%s:tty is busy now", __func__);
164 		return -EBUSY;
165 	}
166 	fifocnt =
167 		ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_RXFFLMASK;
168 	while (fifocnt--) {
169 		u8 flag = TTY_NORMAL;
170 		ch = ltq_r8(port->membase + LTQ_ASC_RBUF);
171 		rsr = (ltq_r32(port->membase + LTQ_ASC_STATE)
172 			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
173 		tty_flip_buffer_push(tty);
174 		port->icount.rx++;
175 
176 		/*
177 		 * Note that the error handling code is
178 		 * out of the main execution path
179 		 */
180 		if (rsr & ASCSTATE_ANY) {
181 			if (rsr & ASCSTATE_PE) {
182 				port->icount.parity++;
183 				ltq_w32_mask(0, ASCWHBSTATE_CLRPE,
184 					port->membase + LTQ_ASC_WHBSTATE);
185 			} else if (rsr & ASCSTATE_FE) {
186 				port->icount.frame++;
187 				ltq_w32_mask(0, ASCWHBSTATE_CLRFE,
188 					port->membase + LTQ_ASC_WHBSTATE);
189 			}
190 			if (rsr & ASCSTATE_ROE) {
191 				port->icount.overrun++;
192 				ltq_w32_mask(0, ASCWHBSTATE_CLRROE,
193 					port->membase + LTQ_ASC_WHBSTATE);
194 			}
195 
196 			rsr &= port->read_status_mask;
197 
198 			if (rsr & ASCSTATE_PE)
199 				flag = TTY_PARITY;
200 			else if (rsr & ASCSTATE_FE)
201 				flag = TTY_FRAME;
202 		}
203 
204 		if ((rsr & port->ignore_status_mask) == 0)
205 			tty_insert_flip_char(tty, ch, flag);
206 
207 		if (rsr & ASCSTATE_ROE)
208 			/*
209 			 * Overrun is special, since it's reported
210 			 * immediately, and doesn't affect the current
211 			 * character
212 			 */
213 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
214 	}
215 	if (ch != 0)
216 		tty_flip_buffer_push(tty);
217 	tty_kref_put(tty);
218 	return 0;
219 }
220 
221 static void
222 lqasc_tx_chars(struct uart_port *port)
223 {
224 	struct circ_buf *xmit = &port->state->xmit;
225 	if (uart_tx_stopped(port)) {
226 		lqasc_stop_tx(port);
227 		return;
228 	}
229 
230 	while (((ltq_r32(port->membase + LTQ_ASC_FSTAT) &
231 		ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
232 		if (port->x_char) {
233 			ltq_w8(port->x_char, port->membase + LTQ_ASC_TBUF);
234 			port->icount.tx++;
235 			port->x_char = 0;
236 			continue;
237 		}
238 
239 		if (uart_circ_empty(xmit))
240 			break;
241 
242 		ltq_w8(port->state->xmit.buf[port->state->xmit.tail],
243 			port->membase + LTQ_ASC_TBUF);
244 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
245 		port->icount.tx++;
246 	}
247 
248 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
249 		uart_write_wakeup(port);
250 }
251 
252 static irqreturn_t
253 lqasc_tx_int(int irq, void *_port)
254 {
255 	unsigned long flags;
256 	struct uart_port *port = (struct uart_port *)_port;
257 	spin_lock_irqsave(&ltq_asc_lock, flags);
258 	ltq_w32(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
259 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
260 	lqasc_start_tx(port);
261 	return IRQ_HANDLED;
262 }
263 
264 static irqreturn_t
265 lqasc_err_int(int irq, void *_port)
266 {
267 	unsigned long flags;
268 	struct uart_port *port = (struct uart_port *)_port;
269 	spin_lock_irqsave(&ltq_asc_lock, flags);
270 	/* clear any pending interrupts */
271 	ltq_w32_mask(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
272 		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
273 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
274 	return IRQ_HANDLED;
275 }
276 
277 static irqreturn_t
278 lqasc_rx_int(int irq, void *_port)
279 {
280 	unsigned long flags;
281 	struct uart_port *port = (struct uart_port *)_port;
282 	spin_lock_irqsave(&ltq_asc_lock, flags);
283 	ltq_w32(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
284 	lqasc_rx_chars(port);
285 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
286 	return IRQ_HANDLED;
287 }
288 
289 static unsigned int
290 lqasc_tx_empty(struct uart_port *port)
291 {
292 	int status;
293 	status = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFFLMASK;
294 	return status ? 0 : TIOCSER_TEMT;
295 }
296 
297 static unsigned int
298 lqasc_get_mctrl(struct uart_port *port)
299 {
300 	return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
301 }
302 
303 static void
304 lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
305 {
306 }
307 
308 static void
309 lqasc_break_ctl(struct uart_port *port, int break_state)
310 {
311 }
312 
313 static int
314 lqasc_startup(struct uart_port *port)
315 {
316 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
317 	int retval;
318 
319 	port->uartclk = clk_get_rate(ltq_port->clk);
320 
321 	ltq_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
322 		port->membase + LTQ_ASC_CLC);
323 
324 	ltq_w32(0, port->membase + LTQ_ASC_PISEL);
325 	ltq_w32(
326 		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
327 		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
328 		port->membase + LTQ_ASC_TXFCON);
329 	ltq_w32(
330 		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
331 		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
332 		port->membase + LTQ_ASC_RXFCON);
333 	/* make sure other settings are written to hardware before
334 	 * setting enable bits
335 	 */
336 	wmb();
337 	ltq_w32_mask(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
338 		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
339 
340 	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
341 		IRQF_DISABLED, "asc_tx", port);
342 	if (retval) {
343 		pr_err("failed to request lqasc_tx_int\n");
344 		return retval;
345 	}
346 
347 	retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
348 		IRQF_DISABLED, "asc_rx", port);
349 	if (retval) {
350 		pr_err("failed to request lqasc_rx_int\n");
351 		goto err1;
352 	}
353 
354 	retval = request_irq(ltq_port->err_irq, lqasc_err_int,
355 		IRQF_DISABLED, "asc_err", port);
356 	if (retval) {
357 		pr_err("failed to request lqasc_err_int\n");
358 		goto err2;
359 	}
360 
361 	ltq_w32(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
362 		port->membase + LTQ_ASC_IRNREN);
363 	return 0;
364 
365 err2:
366 	free_irq(ltq_port->rx_irq, port);
367 err1:
368 	free_irq(ltq_port->tx_irq, port);
369 	return retval;
370 }
371 
372 static void
373 lqasc_shutdown(struct uart_port *port)
374 {
375 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
376 	free_irq(ltq_port->tx_irq, port);
377 	free_irq(ltq_port->rx_irq, port);
378 	free_irq(ltq_port->err_irq, port);
379 
380 	ltq_w32(0, port->membase + LTQ_ASC_CON);
381 	ltq_w32_mask(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
382 		port->membase + LTQ_ASC_RXFCON);
383 	ltq_w32_mask(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
384 		port->membase + LTQ_ASC_TXFCON);
385 }
386 
387 static void
388 lqasc_set_termios(struct uart_port *port,
389 	struct ktermios *new, struct ktermios *old)
390 {
391 	unsigned int cflag;
392 	unsigned int iflag;
393 	unsigned int divisor;
394 	unsigned int baud;
395 	unsigned int con = 0;
396 	unsigned long flags;
397 
398 	cflag = new->c_cflag;
399 	iflag = new->c_iflag;
400 
401 	switch (cflag & CSIZE) {
402 	case CS7:
403 		con = ASCCON_M_7ASYNC;
404 		break;
405 
406 	case CS5:
407 	case CS6:
408 	default:
409 		new->c_cflag &= ~ CSIZE;
410 		new->c_cflag |= CS8;
411 		con = ASCCON_M_8ASYNC;
412 		break;
413 	}
414 
415 	cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
416 
417 	if (cflag & CSTOPB)
418 		con |= ASCCON_STP;
419 
420 	if (cflag & PARENB) {
421 		if (!(cflag & PARODD))
422 			con &= ~ASCCON_ODD;
423 		else
424 			con |= ASCCON_ODD;
425 	}
426 
427 	port->read_status_mask = ASCSTATE_ROE;
428 	if (iflag & INPCK)
429 		port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
430 
431 	port->ignore_status_mask = 0;
432 	if (iflag & IGNPAR)
433 		port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
434 
435 	if (iflag & IGNBRK) {
436 		/*
437 		 * If we're ignoring parity and break indicators,
438 		 * ignore overruns too (for real raw support).
439 		 */
440 		if (iflag & IGNPAR)
441 			port->ignore_status_mask |= ASCSTATE_ROE;
442 	}
443 
444 	if ((cflag & CREAD) == 0)
445 		port->ignore_status_mask |= UART_DUMMY_UER_RX;
446 
447 	/* set error signals  - framing, parity  and overrun, enable receiver */
448 	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
449 
450 	spin_lock_irqsave(&ltq_asc_lock, flags);
451 
452 	/* set up CON */
453 	ltq_w32_mask(0, con, port->membase + LTQ_ASC_CON);
454 
455 	/* Set baud rate - take a divider of 2 into account */
456 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
457 	divisor = uart_get_divisor(port, baud);
458 	divisor = divisor / 2 - 1;
459 
460 	/* disable the baudrate generator */
461 	ltq_w32_mask(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
462 
463 	/* make sure the fractional divider is off */
464 	ltq_w32_mask(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
465 
466 	/* set up to use divisor of 2 */
467 	ltq_w32_mask(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
468 
469 	/* now we can write the new baudrate into the register */
470 	ltq_w32(divisor, port->membase + LTQ_ASC_BG);
471 
472 	/* turn the baudrate generator back on */
473 	ltq_w32_mask(0, ASCCON_R, port->membase + LTQ_ASC_CON);
474 
475 	/* enable rx */
476 	ltq_w32(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
477 
478 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
479 
480 	/* Don't rewrite B0 */
481         if (tty_termios_baud_rate(new))
482 		tty_termios_encode_baud_rate(new, baud, baud);
483 }
484 
485 static const char*
486 lqasc_type(struct uart_port *port)
487 {
488 	if (port->type == PORT_LTQ_ASC)
489 		return DRVNAME;
490 	else
491 		return NULL;
492 }
493 
494 static void
495 lqasc_release_port(struct uart_port *port)
496 {
497 	if (port->flags & UPF_IOREMAP) {
498 		iounmap(port->membase);
499 		port->membase = NULL;
500 	}
501 }
502 
503 static int
504 lqasc_request_port(struct uart_port *port)
505 {
506 	struct platform_device *pdev = to_platform_device(port->dev);
507 	struct resource *res;
508 	int size;
509 
510 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
511 	if (!res) {
512 		dev_err(&pdev->dev, "cannot obtain I/O memory region");
513 		return -ENODEV;
514 	}
515 	size = resource_size(res);
516 
517 	res = devm_request_mem_region(&pdev->dev, res->start,
518 		size, dev_name(&pdev->dev));
519 	if (!res) {
520 		dev_err(&pdev->dev, "cannot request I/O memory region");
521 		return -EBUSY;
522 	}
523 
524 	if (port->flags & UPF_IOREMAP) {
525 		port->membase = devm_ioremap_nocache(&pdev->dev,
526 			port->mapbase, size);
527 		if (port->membase == NULL)
528 			return -ENOMEM;
529 	}
530 	return 0;
531 }
532 
533 static void
534 lqasc_config_port(struct uart_port *port, int flags)
535 {
536 	if (flags & UART_CONFIG_TYPE) {
537 		port->type = PORT_LTQ_ASC;
538 		lqasc_request_port(port);
539 	}
540 }
541 
542 static int
543 lqasc_verify_port(struct uart_port *port,
544 	struct serial_struct *ser)
545 {
546 	int ret = 0;
547 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
548 		ret = -EINVAL;
549 	if (ser->irq < 0 || ser->irq >= NR_IRQS)
550 		ret = -EINVAL;
551 	if (ser->baud_base < 9600)
552 		ret = -EINVAL;
553 	return ret;
554 }
555 
556 static struct uart_ops lqasc_pops = {
557 	.tx_empty =	lqasc_tx_empty,
558 	.set_mctrl =	lqasc_set_mctrl,
559 	.get_mctrl =	lqasc_get_mctrl,
560 	.stop_tx =	lqasc_stop_tx,
561 	.start_tx =	lqasc_start_tx,
562 	.stop_rx =	lqasc_stop_rx,
563 	.enable_ms =	lqasc_enable_ms,
564 	.break_ctl =	lqasc_break_ctl,
565 	.startup =	lqasc_startup,
566 	.shutdown =	lqasc_shutdown,
567 	.set_termios =	lqasc_set_termios,
568 	.type =		lqasc_type,
569 	.release_port =	lqasc_release_port,
570 	.request_port =	lqasc_request_port,
571 	.config_port =	lqasc_config_port,
572 	.verify_port =	lqasc_verify_port,
573 };
574 
575 static void
576 lqasc_console_putchar(struct uart_port *port, int ch)
577 {
578 	int fifofree;
579 
580 	if (!port->membase)
581 		return;
582 
583 	do {
584 		fifofree = (ltq_r32(port->membase + LTQ_ASC_FSTAT)
585 			& ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
586 	} while (fifofree == 0);
587 	ltq_w8(ch, port->membase + LTQ_ASC_TBUF);
588 }
589 
590 
591 static void
592 lqasc_console_write(struct console *co, const char *s, u_int count)
593 {
594 	struct ltq_uart_port *ltq_port;
595 	struct uart_port *port;
596 	unsigned long flags;
597 
598 	if (co->index >= MAXPORTS)
599 		return;
600 
601 	ltq_port = lqasc_port[co->index];
602 	if (!ltq_port)
603 		return;
604 
605 	port = &ltq_port->port;
606 
607 	spin_lock_irqsave(&ltq_asc_lock, flags);
608 	uart_console_write(port, s, count, lqasc_console_putchar);
609 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
610 }
611 
612 static int __init
613 lqasc_console_setup(struct console *co, char *options)
614 {
615 	struct ltq_uart_port *ltq_port;
616 	struct uart_port *port;
617 	int baud = 115200;
618 	int bits = 8;
619 	int parity = 'n';
620 	int flow = 'n';
621 
622 	if (co->index >= MAXPORTS)
623 		return -ENODEV;
624 
625 	ltq_port = lqasc_port[co->index];
626 	if (!ltq_port)
627 		return -ENODEV;
628 
629 	port = &ltq_port->port;
630 
631 	port->uartclk = clk_get_rate(ltq_port->clk);
632 
633 	if (options)
634 		uart_parse_options(options, &baud, &parity, &bits, &flow);
635 	return uart_set_options(port, co, baud, parity, bits, flow);
636 }
637 
638 static struct console lqasc_console = {
639 	.name =		"ttyLTQ",
640 	.write =	lqasc_console_write,
641 	.device =	uart_console_device,
642 	.setup =	lqasc_console_setup,
643 	.flags =	CON_PRINTBUFFER,
644 	.index =	-1,
645 	.data =		&lqasc_reg,
646 };
647 
648 static int __init
649 lqasc_console_init(void)
650 {
651 	register_console(&lqasc_console);
652 	return 0;
653 }
654 console_initcall(lqasc_console_init);
655 
656 static struct uart_driver lqasc_reg = {
657 	.owner =	THIS_MODULE,
658 	.driver_name =	DRVNAME,
659 	.dev_name =	"ttyLTQ",
660 	.major =	0,
661 	.minor =	0,
662 	.nr =		MAXPORTS,
663 	.cons =		&lqasc_console,
664 };
665 
666 static int __init
667 lqasc_probe(struct platform_device *pdev)
668 {
669 	struct ltq_uart_port *ltq_port;
670 	struct uart_port *port;
671 	struct resource *mmres, *irqres;
672 	int tx_irq, rx_irq, err_irq;
673 	struct clk *clk;
674 	int ret;
675 
676 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
677 	irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
678 	if (!mmres || !irqres)
679 		return -ENODEV;
680 
681 	if (pdev->id >= MAXPORTS)
682 		return -EBUSY;
683 
684 	if (lqasc_port[pdev->id] != NULL)
685 		return -EBUSY;
686 
687 	clk = clk_get(&pdev->dev, "fpi");
688 	if (IS_ERR(clk)) {
689 		pr_err("failed to get fpi clk\n");
690 		return -ENOENT;
691 	}
692 
693 	tx_irq = platform_get_irq_byname(pdev, "tx");
694 	rx_irq = platform_get_irq_byname(pdev, "rx");
695 	err_irq = platform_get_irq_byname(pdev, "err");
696 	if ((tx_irq < 0) | (rx_irq < 0) | (err_irq < 0))
697 		return -ENODEV;
698 
699 	ltq_port = kzalloc(sizeof(struct ltq_uart_port), GFP_KERNEL);
700 	if (!ltq_port)
701 		return -ENOMEM;
702 
703 	port = &ltq_port->port;
704 
705 	port->iotype	= SERIAL_IO_MEM;
706 	port->flags	= ASYNC_BOOT_AUTOCONF | UPF_IOREMAP;
707 	port->ops	= &lqasc_pops;
708 	port->fifosize	= 16;
709 	port->type	= PORT_LTQ_ASC,
710 	port->line	= pdev->id;
711 	port->dev	= &pdev->dev;
712 
713 	port->irq	= tx_irq; /* unused, just to be backward-compatibe */
714 	port->mapbase	= mmres->start;
715 
716 	ltq_port->clk	= clk;
717 
718 	ltq_port->tx_irq = tx_irq;
719 	ltq_port->rx_irq = rx_irq;
720 	ltq_port->err_irq = err_irq;
721 
722 	lqasc_port[pdev->id] = ltq_port;
723 	platform_set_drvdata(pdev, ltq_port);
724 
725 	ret = uart_add_one_port(&lqasc_reg, port);
726 
727 	return ret;
728 }
729 
730 static struct platform_driver lqasc_driver = {
731 	.driver		= {
732 		.name	= DRVNAME,
733 		.owner	= THIS_MODULE,
734 	},
735 };
736 
737 int __init
738 init_lqasc(void)
739 {
740 	int ret;
741 
742 	ret = uart_register_driver(&lqasc_reg);
743 	if (ret != 0)
744 		return ret;
745 
746 	ret = platform_driver_probe(&lqasc_driver, lqasc_probe);
747 	if (ret != 0)
748 		uart_unregister_driver(&lqasc_reg);
749 
750 	return ret;
751 }
752 
753 module_init(init_lqasc);
754 
755 MODULE_DESCRIPTION("Lantiq serial port driver");
756 MODULE_LICENSE("GPL");
757