xref: /openbmc/linux/drivers/tty/serial/lantiq.c (revision 12eb4683)
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/of_platform.h>
35 #include <linux/of_address.h>
36 #include <linux/of_irq.h>
37 #include <linux/io.h>
38 #include <linux/clk.h>
39 #include <linux/gpio.h>
40 
41 #include <lantiq_soc.h>
42 
43 #define PORT_LTQ_ASC		111
44 #define MAXPORTS		2
45 #define UART_DUMMY_UER_RX	1
46 #define DRVNAME			"lantiq,asc"
47 #ifdef __BIG_ENDIAN
48 #define LTQ_ASC_TBUF		(0x0020 + 3)
49 #define LTQ_ASC_RBUF		(0x0024 + 3)
50 #else
51 #define LTQ_ASC_TBUF		0x0020
52 #define LTQ_ASC_RBUF		0x0024
53 #endif
54 #define LTQ_ASC_FSTAT		0x0048
55 #define LTQ_ASC_WHBSTATE	0x0018
56 #define LTQ_ASC_STATE		0x0014
57 #define LTQ_ASC_IRNCR		0x00F8
58 #define LTQ_ASC_CLC		0x0000
59 #define LTQ_ASC_ID		0x0008
60 #define LTQ_ASC_PISEL		0x0004
61 #define LTQ_ASC_TXFCON		0x0044
62 #define LTQ_ASC_RXFCON		0x0040
63 #define LTQ_ASC_CON		0x0010
64 #define LTQ_ASC_BG		0x0050
65 #define LTQ_ASC_IRNREN		0x00F4
66 
67 #define ASC_IRNREN_TX		0x1
68 #define ASC_IRNREN_RX		0x2
69 #define ASC_IRNREN_ERR		0x4
70 #define ASC_IRNREN_TX_BUF	0x8
71 #define ASC_IRNCR_TIR		0x1
72 #define ASC_IRNCR_RIR		0x2
73 #define ASC_IRNCR_EIR		0x4
74 
75 #define ASCOPT_CSIZE		0x3
76 #define TXFIFO_FL		1
77 #define RXFIFO_FL		1
78 #define ASCCLC_DISS		0x2
79 #define ASCCLC_RMCMASK		0x0000FF00
80 #define ASCCLC_RMCOFFSET	8
81 #define ASCCON_M_8ASYNC		0x0
82 #define ASCCON_M_7ASYNC		0x2
83 #define ASCCON_ODD		0x00000020
84 #define ASCCON_STP		0x00000080
85 #define ASCCON_BRS		0x00000100
86 #define ASCCON_FDE		0x00000200
87 #define ASCCON_R		0x00008000
88 #define ASCCON_FEN		0x00020000
89 #define ASCCON_ROEN		0x00080000
90 #define ASCCON_TOEN		0x00100000
91 #define ASCSTATE_PE		0x00010000
92 #define ASCSTATE_FE		0x00020000
93 #define ASCSTATE_ROE		0x00080000
94 #define ASCSTATE_ANY		(ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
95 #define ASCWHBSTATE_CLRREN	0x00000001
96 #define ASCWHBSTATE_SETREN	0x00000002
97 #define ASCWHBSTATE_CLRPE	0x00000004
98 #define ASCWHBSTATE_CLRFE	0x00000008
99 #define ASCWHBSTATE_CLRROE	0x00000020
100 #define ASCTXFCON_TXFEN		0x0001
101 #define ASCTXFCON_TXFFLU	0x0002
102 #define ASCTXFCON_TXFITLMASK	0x3F00
103 #define ASCTXFCON_TXFITLOFF	8
104 #define ASCRXFCON_RXFEN		0x0001
105 #define ASCRXFCON_RXFFLU	0x0002
106 #define ASCRXFCON_RXFITLMASK	0x3F00
107 #define ASCRXFCON_RXFITLOFF	8
108 #define ASCFSTAT_RXFFLMASK	0x003F
109 #define ASCFSTAT_TXFFLMASK	0x3F00
110 #define ASCFSTAT_TXFREEMASK	0x3F000000
111 #define ASCFSTAT_TXFREEOFF	24
112 
113 static void lqasc_tx_chars(struct uart_port *port);
114 static struct ltq_uart_port *lqasc_port[MAXPORTS];
115 static struct uart_driver lqasc_reg;
116 static DEFINE_SPINLOCK(ltq_asc_lock);
117 
118 struct ltq_uart_port {
119 	struct uart_port	port;
120 	/* clock used to derive divider */
121 	struct clk		*fpiclk;
122 	/* clock gating of the ASC core */
123 	struct clk		*clk;
124 	unsigned int		tx_irq;
125 	unsigned int		rx_irq;
126 	unsigned int		err_irq;
127 };
128 
129 static inline struct
130 ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
131 {
132 	return container_of(port, struct ltq_uart_port, port);
133 }
134 
135 static void
136 lqasc_stop_tx(struct uart_port *port)
137 {
138 	return;
139 }
140 
141 static void
142 lqasc_start_tx(struct uart_port *port)
143 {
144 	unsigned long flags;
145 	spin_lock_irqsave(&ltq_asc_lock, flags);
146 	lqasc_tx_chars(port);
147 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
148 	return;
149 }
150 
151 static void
152 lqasc_stop_rx(struct uart_port *port)
153 {
154 	ltq_w32(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
155 }
156 
157 static void
158 lqasc_enable_ms(struct uart_port *port)
159 {
160 }
161 
162 static int
163 lqasc_rx_chars(struct uart_port *port)
164 {
165 	struct tty_port *tport = &port->state->port;
166 	unsigned int ch = 0, rsr = 0, fifocnt;
167 
168 	fifocnt = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_RXFFLMASK;
169 	while (fifocnt--) {
170 		u8 flag = TTY_NORMAL;
171 		ch = ltq_r8(port->membase + LTQ_ASC_RBUF);
172 		rsr = (ltq_r32(port->membase + LTQ_ASC_STATE)
173 			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
174 		tty_flip_buffer_push(tport);
175 		port->icount.rx++;
176 
177 		/*
178 		 * Note that the error handling code is
179 		 * out of the main execution path
180 		 */
181 		if (rsr & ASCSTATE_ANY) {
182 			if (rsr & ASCSTATE_PE) {
183 				port->icount.parity++;
184 				ltq_w32_mask(0, ASCWHBSTATE_CLRPE,
185 					port->membase + LTQ_ASC_WHBSTATE);
186 			} else if (rsr & ASCSTATE_FE) {
187 				port->icount.frame++;
188 				ltq_w32_mask(0, ASCWHBSTATE_CLRFE,
189 					port->membase + LTQ_ASC_WHBSTATE);
190 			}
191 			if (rsr & ASCSTATE_ROE) {
192 				port->icount.overrun++;
193 				ltq_w32_mask(0, ASCWHBSTATE_CLRROE,
194 					port->membase + LTQ_ASC_WHBSTATE);
195 			}
196 
197 			rsr &= port->read_status_mask;
198 
199 			if (rsr & ASCSTATE_PE)
200 				flag = TTY_PARITY;
201 			else if (rsr & ASCSTATE_FE)
202 				flag = TTY_FRAME;
203 		}
204 
205 		if ((rsr & port->ignore_status_mask) == 0)
206 			tty_insert_flip_char(tport, ch, flag);
207 
208 		if (rsr & ASCSTATE_ROE)
209 			/*
210 			 * Overrun is special, since it's reported
211 			 * immediately, and doesn't affect the current
212 			 * character
213 			 */
214 			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
215 	}
216 
217 	if (ch != 0)
218 		tty_flip_buffer_push(tport);
219 
220 	return 0;
221 }
222 
223 static void
224 lqasc_tx_chars(struct uart_port *port)
225 {
226 	struct circ_buf *xmit = &port->state->xmit;
227 	if (uart_tx_stopped(port)) {
228 		lqasc_stop_tx(port);
229 		return;
230 	}
231 
232 	while (((ltq_r32(port->membase + LTQ_ASC_FSTAT) &
233 		ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
234 		if (port->x_char) {
235 			ltq_w8(port->x_char, port->membase + LTQ_ASC_TBUF);
236 			port->icount.tx++;
237 			port->x_char = 0;
238 			continue;
239 		}
240 
241 		if (uart_circ_empty(xmit))
242 			break;
243 
244 		ltq_w8(port->state->xmit.buf[port->state->xmit.tail],
245 			port->membase + LTQ_ASC_TBUF);
246 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
247 		port->icount.tx++;
248 	}
249 
250 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
251 		uart_write_wakeup(port);
252 }
253 
254 static irqreturn_t
255 lqasc_tx_int(int irq, void *_port)
256 {
257 	unsigned long flags;
258 	struct uart_port *port = (struct uart_port *)_port;
259 	spin_lock_irqsave(&ltq_asc_lock, flags);
260 	ltq_w32(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
261 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
262 	lqasc_start_tx(port);
263 	return IRQ_HANDLED;
264 }
265 
266 static irqreturn_t
267 lqasc_err_int(int irq, void *_port)
268 {
269 	unsigned long flags;
270 	struct uart_port *port = (struct uart_port *)_port;
271 	spin_lock_irqsave(&ltq_asc_lock, flags);
272 	/* clear any pending interrupts */
273 	ltq_w32_mask(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
274 		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
275 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
276 	return IRQ_HANDLED;
277 }
278 
279 static irqreturn_t
280 lqasc_rx_int(int irq, void *_port)
281 {
282 	unsigned long flags;
283 	struct uart_port *port = (struct uart_port *)_port;
284 	spin_lock_irqsave(&ltq_asc_lock, flags);
285 	ltq_w32(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
286 	lqasc_rx_chars(port);
287 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
288 	return IRQ_HANDLED;
289 }
290 
291 static unsigned int
292 lqasc_tx_empty(struct uart_port *port)
293 {
294 	int status;
295 	status = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFFLMASK;
296 	return status ? 0 : TIOCSER_TEMT;
297 }
298 
299 static unsigned int
300 lqasc_get_mctrl(struct uart_port *port)
301 {
302 	return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
303 }
304 
305 static void
306 lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
307 {
308 }
309 
310 static void
311 lqasc_break_ctl(struct uart_port *port, int break_state)
312 {
313 }
314 
315 static int
316 lqasc_startup(struct uart_port *port)
317 {
318 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
319 	int retval;
320 
321 	if (!IS_ERR(ltq_port->clk))
322 		clk_enable(ltq_port->clk);
323 	port->uartclk = clk_get_rate(ltq_port->fpiclk);
324 
325 	ltq_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
326 		port->membase + LTQ_ASC_CLC);
327 
328 	ltq_w32(0, port->membase + LTQ_ASC_PISEL);
329 	ltq_w32(
330 		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
331 		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
332 		port->membase + LTQ_ASC_TXFCON);
333 	ltq_w32(
334 		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
335 		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
336 		port->membase + LTQ_ASC_RXFCON);
337 	/* make sure other settings are written to hardware before
338 	 * setting enable bits
339 	 */
340 	wmb();
341 	ltq_w32_mask(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
342 		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
343 
344 	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
345 		0, "asc_tx", port);
346 	if (retval) {
347 		pr_err("failed to request lqasc_tx_int\n");
348 		return retval;
349 	}
350 
351 	retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
352 		0, "asc_rx", port);
353 	if (retval) {
354 		pr_err("failed to request lqasc_rx_int\n");
355 		goto err1;
356 	}
357 
358 	retval = request_irq(ltq_port->err_irq, lqasc_err_int,
359 		0, "asc_err", port);
360 	if (retval) {
361 		pr_err("failed to request lqasc_err_int\n");
362 		goto err2;
363 	}
364 
365 	ltq_w32(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
366 		port->membase + LTQ_ASC_IRNREN);
367 	return 0;
368 
369 err2:
370 	free_irq(ltq_port->rx_irq, port);
371 err1:
372 	free_irq(ltq_port->tx_irq, port);
373 	return retval;
374 }
375 
376 static void
377 lqasc_shutdown(struct uart_port *port)
378 {
379 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
380 	free_irq(ltq_port->tx_irq, port);
381 	free_irq(ltq_port->rx_irq, port);
382 	free_irq(ltq_port->err_irq, port);
383 
384 	ltq_w32(0, port->membase + LTQ_ASC_CON);
385 	ltq_w32_mask(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
386 		port->membase + LTQ_ASC_RXFCON);
387 	ltq_w32_mask(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
388 		port->membase + LTQ_ASC_TXFCON);
389 	if (!IS_ERR(ltq_port->clk))
390 		clk_disable(ltq_port->clk);
391 }
392 
393 static void
394 lqasc_set_termios(struct uart_port *port,
395 	struct ktermios *new, struct ktermios *old)
396 {
397 	unsigned int cflag;
398 	unsigned int iflag;
399 	unsigned int divisor;
400 	unsigned int baud;
401 	unsigned int con = 0;
402 	unsigned long flags;
403 
404 	cflag = new->c_cflag;
405 	iflag = new->c_iflag;
406 
407 	switch (cflag & CSIZE) {
408 	case CS7:
409 		con = ASCCON_M_7ASYNC;
410 		break;
411 
412 	case CS5:
413 	case CS6:
414 	default:
415 		new->c_cflag &= ~ CSIZE;
416 		new->c_cflag |= CS8;
417 		con = ASCCON_M_8ASYNC;
418 		break;
419 	}
420 
421 	cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
422 
423 	if (cflag & CSTOPB)
424 		con |= ASCCON_STP;
425 
426 	if (cflag & PARENB) {
427 		if (!(cflag & PARODD))
428 			con &= ~ASCCON_ODD;
429 		else
430 			con |= ASCCON_ODD;
431 	}
432 
433 	port->read_status_mask = ASCSTATE_ROE;
434 	if (iflag & INPCK)
435 		port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
436 
437 	port->ignore_status_mask = 0;
438 	if (iflag & IGNPAR)
439 		port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
440 
441 	if (iflag & IGNBRK) {
442 		/*
443 		 * If we're ignoring parity and break indicators,
444 		 * ignore overruns too (for real raw support).
445 		 */
446 		if (iflag & IGNPAR)
447 			port->ignore_status_mask |= ASCSTATE_ROE;
448 	}
449 
450 	if ((cflag & CREAD) == 0)
451 		port->ignore_status_mask |= UART_DUMMY_UER_RX;
452 
453 	/* set error signals  - framing, parity  and overrun, enable receiver */
454 	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
455 
456 	spin_lock_irqsave(&ltq_asc_lock, flags);
457 
458 	/* set up CON */
459 	ltq_w32_mask(0, con, port->membase + LTQ_ASC_CON);
460 
461 	/* Set baud rate - take a divider of 2 into account */
462 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
463 	divisor = uart_get_divisor(port, baud);
464 	divisor = divisor / 2 - 1;
465 
466 	/* disable the baudrate generator */
467 	ltq_w32_mask(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
468 
469 	/* make sure the fractional divider is off */
470 	ltq_w32_mask(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
471 
472 	/* set up to use divisor of 2 */
473 	ltq_w32_mask(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
474 
475 	/* now we can write the new baudrate into the register */
476 	ltq_w32(divisor, port->membase + LTQ_ASC_BG);
477 
478 	/* turn the baudrate generator back on */
479 	ltq_w32_mask(0, ASCCON_R, port->membase + LTQ_ASC_CON);
480 
481 	/* enable rx */
482 	ltq_w32(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
483 
484 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
485 
486 	/* Don't rewrite B0 */
487 	if (tty_termios_baud_rate(new))
488 		tty_termios_encode_baud_rate(new, baud, baud);
489 
490 	uart_update_timeout(port, cflag, baud);
491 }
492 
493 static const char*
494 lqasc_type(struct uart_port *port)
495 {
496 	if (port->type == PORT_LTQ_ASC)
497 		return DRVNAME;
498 	else
499 		return NULL;
500 }
501 
502 static void
503 lqasc_release_port(struct uart_port *port)
504 {
505 	if (port->flags & UPF_IOREMAP) {
506 		iounmap(port->membase);
507 		port->membase = NULL;
508 	}
509 }
510 
511 static int
512 lqasc_request_port(struct uart_port *port)
513 {
514 	struct platform_device *pdev = to_platform_device(port->dev);
515 	struct resource *res;
516 	int size;
517 
518 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
519 	if (!res) {
520 		dev_err(&pdev->dev, "cannot obtain I/O memory region");
521 		return -ENODEV;
522 	}
523 	size = resource_size(res);
524 
525 	res = devm_request_mem_region(&pdev->dev, res->start,
526 		size, dev_name(&pdev->dev));
527 	if (!res) {
528 		dev_err(&pdev->dev, "cannot request I/O memory region");
529 		return -EBUSY;
530 	}
531 
532 	if (port->flags & UPF_IOREMAP) {
533 		port->membase = devm_ioremap_nocache(&pdev->dev,
534 			port->mapbase, size);
535 		if (port->membase == NULL)
536 			return -ENOMEM;
537 	}
538 	return 0;
539 }
540 
541 static void
542 lqasc_config_port(struct uart_port *port, int flags)
543 {
544 	if (flags & UART_CONFIG_TYPE) {
545 		port->type = PORT_LTQ_ASC;
546 		lqasc_request_port(port);
547 	}
548 }
549 
550 static int
551 lqasc_verify_port(struct uart_port *port,
552 	struct serial_struct *ser)
553 {
554 	int ret = 0;
555 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
556 		ret = -EINVAL;
557 	if (ser->irq < 0 || ser->irq >= NR_IRQS)
558 		ret = -EINVAL;
559 	if (ser->baud_base < 9600)
560 		ret = -EINVAL;
561 	return ret;
562 }
563 
564 static struct uart_ops lqasc_pops = {
565 	.tx_empty =	lqasc_tx_empty,
566 	.set_mctrl =	lqasc_set_mctrl,
567 	.get_mctrl =	lqasc_get_mctrl,
568 	.stop_tx =	lqasc_stop_tx,
569 	.start_tx =	lqasc_start_tx,
570 	.stop_rx =	lqasc_stop_rx,
571 	.enable_ms =	lqasc_enable_ms,
572 	.break_ctl =	lqasc_break_ctl,
573 	.startup =	lqasc_startup,
574 	.shutdown =	lqasc_shutdown,
575 	.set_termios =	lqasc_set_termios,
576 	.type =		lqasc_type,
577 	.release_port =	lqasc_release_port,
578 	.request_port =	lqasc_request_port,
579 	.config_port =	lqasc_config_port,
580 	.verify_port =	lqasc_verify_port,
581 };
582 
583 static void
584 lqasc_console_putchar(struct uart_port *port, int ch)
585 {
586 	int fifofree;
587 
588 	if (!port->membase)
589 		return;
590 
591 	do {
592 		fifofree = (ltq_r32(port->membase + LTQ_ASC_FSTAT)
593 			& ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
594 	} while (fifofree == 0);
595 	ltq_w8(ch, port->membase + LTQ_ASC_TBUF);
596 }
597 
598 
599 static void
600 lqasc_console_write(struct console *co, const char *s, u_int count)
601 {
602 	struct ltq_uart_port *ltq_port;
603 	struct uart_port *port;
604 	unsigned long flags;
605 
606 	if (co->index >= MAXPORTS)
607 		return;
608 
609 	ltq_port = lqasc_port[co->index];
610 	if (!ltq_port)
611 		return;
612 
613 	port = &ltq_port->port;
614 
615 	spin_lock_irqsave(&ltq_asc_lock, flags);
616 	uart_console_write(port, s, count, lqasc_console_putchar);
617 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
618 }
619 
620 static int __init
621 lqasc_console_setup(struct console *co, char *options)
622 {
623 	struct ltq_uart_port *ltq_port;
624 	struct uart_port *port;
625 	int baud = 115200;
626 	int bits = 8;
627 	int parity = 'n';
628 	int flow = 'n';
629 
630 	if (co->index >= MAXPORTS)
631 		return -ENODEV;
632 
633 	ltq_port = lqasc_port[co->index];
634 	if (!ltq_port)
635 		return -ENODEV;
636 
637 	port = &ltq_port->port;
638 
639 	if (!IS_ERR(ltq_port->clk))
640 		clk_enable(ltq_port->clk);
641 
642 	port->uartclk = clk_get_rate(ltq_port->fpiclk);
643 
644 	if (options)
645 		uart_parse_options(options, &baud, &parity, &bits, &flow);
646 	return uart_set_options(port, co, baud, parity, bits, flow);
647 }
648 
649 static struct console lqasc_console = {
650 	.name =		"ttyLTQ",
651 	.write =	lqasc_console_write,
652 	.device =	uart_console_device,
653 	.setup =	lqasc_console_setup,
654 	.flags =	CON_PRINTBUFFER,
655 	.index =	-1,
656 	.data =		&lqasc_reg,
657 };
658 
659 static int __init
660 lqasc_console_init(void)
661 {
662 	register_console(&lqasc_console);
663 	return 0;
664 }
665 console_initcall(lqasc_console_init);
666 
667 static struct uart_driver lqasc_reg = {
668 	.owner =	THIS_MODULE,
669 	.driver_name =	DRVNAME,
670 	.dev_name =	"ttyLTQ",
671 	.major =	0,
672 	.minor =	0,
673 	.nr =		MAXPORTS,
674 	.cons =		&lqasc_console,
675 };
676 
677 static int __init
678 lqasc_probe(struct platform_device *pdev)
679 {
680 	struct device_node *node = pdev->dev.of_node;
681 	struct ltq_uart_port *ltq_port;
682 	struct uart_port *port;
683 	struct resource *mmres, irqres[3];
684 	int line = 0;
685 	int ret;
686 
687 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
688 	ret = of_irq_to_resource_table(node, irqres, 3);
689 	if (!mmres || (ret != 3)) {
690 		dev_err(&pdev->dev,
691 			"failed to get memory/irq for serial port\n");
692 		return -ENODEV;
693 	}
694 
695 	/* check if this is the console port */
696 	if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC))
697 		line = 1;
698 
699 	if (lqasc_port[line]) {
700 		dev_err(&pdev->dev, "port %d already allocated\n", line);
701 		return -EBUSY;
702 	}
703 
704 	ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
705 			GFP_KERNEL);
706 	if (!ltq_port)
707 		return -ENOMEM;
708 
709 	port = &ltq_port->port;
710 
711 	port->iotype	= SERIAL_IO_MEM;
712 	port->flags	= ASYNC_BOOT_AUTOCONF | UPF_IOREMAP;
713 	port->ops	= &lqasc_pops;
714 	port->fifosize	= 16;
715 	port->type	= PORT_LTQ_ASC,
716 	port->line	= line;
717 	port->dev	= &pdev->dev;
718 	/* unused, just to be backward-compatible */
719 	port->irq	= irqres[0].start;
720 	port->mapbase	= mmres->start;
721 
722 	ltq_port->fpiclk = clk_get_fpi();
723 	if (IS_ERR(ltq_port->fpiclk)) {
724 		pr_err("failed to get fpi clk\n");
725 		return -ENOENT;
726 	}
727 
728 	/* not all asc ports have clock gates, lets ignore the return code */
729 	ltq_port->clk = clk_get(&pdev->dev, NULL);
730 
731 	ltq_port->tx_irq = irqres[0].start;
732 	ltq_port->rx_irq = irqres[1].start;
733 	ltq_port->err_irq = irqres[2].start;
734 
735 	lqasc_port[line] = ltq_port;
736 	platform_set_drvdata(pdev, ltq_port);
737 
738 	ret = uart_add_one_port(&lqasc_reg, port);
739 
740 	return ret;
741 }
742 
743 static const struct of_device_id ltq_asc_match[] = {
744 	{ .compatible = DRVNAME },
745 	{},
746 };
747 MODULE_DEVICE_TABLE(of, ltq_asc_match);
748 
749 static struct platform_driver lqasc_driver = {
750 	.driver		= {
751 		.name	= DRVNAME,
752 		.owner	= THIS_MODULE,
753 		.of_match_table = ltq_asc_match,
754 	},
755 };
756 
757 int __init
758 init_lqasc(void)
759 {
760 	int ret;
761 
762 	ret = uart_register_driver(&lqasc_reg);
763 	if (ret != 0)
764 		return ret;
765 
766 	ret = platform_driver_probe(&lqasc_driver, lqasc_probe);
767 	if (ret != 0)
768 		uart_unregister_driver(&lqasc_reg);
769 
770 	return ret;
771 }
772 
773 module_init(init_lqasc);
774 
775 MODULE_DESCRIPTION("Lantiq serial port driver");
776 MODULE_LICENSE("GPL");
777