xref: /linux/drivers/tty/serial/mxs-auart.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /*
2  * Freescale STMP37XX/STMP378X Application UART driver
3  *
4  * Author: dmitry pervushin <dimka@embeddedalley.com>
5  *
6  * Copyright 2008-2010 Freescale Semiconductor, Inc.
7  * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
8  *
9  * The code contained herein is licensed under the GNU General Public
10  * License. You may obtain a copy of the GNU General Public License
11  * Version 2 or later at the following locations:
12  *
13  * http://www.opensource.org/licenses/gpl-license.html
14  * http://www.gnu.org/copyleft/gpl.html
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/init.h>
20 #include <linux/console.h>
21 #include <linux/interrupt.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/wait.h>
25 #include <linux/tty.h>
26 #include <linux/tty_driver.h>
27 #include <linux/tty_flip.h>
28 #include <linux/serial.h>
29 #include <linux/serial_core.h>
30 #include <linux/platform_device.h>
31 #include <linux/device.h>
32 #include <linux/clk.h>
33 #include <linux/delay.h>
34 #include <linux/io.h>
35 
36 #include <asm/cacheflush.h>
37 
38 #define MXS_AUART_PORTS 5
39 
40 #define AUART_CTRL0			0x00000000
41 #define AUART_CTRL0_SET			0x00000004
42 #define AUART_CTRL0_CLR			0x00000008
43 #define AUART_CTRL0_TOG			0x0000000c
44 #define AUART_CTRL1			0x00000010
45 #define AUART_CTRL1_SET			0x00000014
46 #define AUART_CTRL1_CLR			0x00000018
47 #define AUART_CTRL1_TOG			0x0000001c
48 #define AUART_CTRL2			0x00000020
49 #define AUART_CTRL2_SET			0x00000024
50 #define AUART_CTRL2_CLR			0x00000028
51 #define AUART_CTRL2_TOG			0x0000002c
52 #define AUART_LINECTRL			0x00000030
53 #define AUART_LINECTRL_SET		0x00000034
54 #define AUART_LINECTRL_CLR		0x00000038
55 #define AUART_LINECTRL_TOG		0x0000003c
56 #define AUART_LINECTRL2			0x00000040
57 #define AUART_LINECTRL2_SET		0x00000044
58 #define AUART_LINECTRL2_CLR		0x00000048
59 #define AUART_LINECTRL2_TOG		0x0000004c
60 #define AUART_INTR			0x00000050
61 #define AUART_INTR_SET			0x00000054
62 #define AUART_INTR_CLR			0x00000058
63 #define AUART_INTR_TOG			0x0000005c
64 #define AUART_DATA			0x00000060
65 #define AUART_STAT			0x00000070
66 #define AUART_DEBUG			0x00000080
67 #define AUART_VERSION			0x00000090
68 #define AUART_AUTOBAUD			0x000000a0
69 
70 #define AUART_CTRL0_SFTRST			(1 << 31)
71 #define AUART_CTRL0_CLKGATE			(1 << 30)
72 
73 #define AUART_CTRL2_CTSEN			(1 << 15)
74 #define AUART_CTRL2_RTS				(1 << 11)
75 #define AUART_CTRL2_RXE				(1 << 9)
76 #define AUART_CTRL2_TXE				(1 << 8)
77 #define AUART_CTRL2_UARTEN			(1 << 0)
78 
79 #define AUART_LINECTRL_BAUD_DIVINT_SHIFT	16
80 #define AUART_LINECTRL_BAUD_DIVINT_MASK		0xffff0000
81 #define AUART_LINECTRL_BAUD_DIVINT(v)		(((v) & 0xffff) << 16)
82 #define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT	8
83 #define AUART_LINECTRL_BAUD_DIVFRAC_MASK	0x00003f00
84 #define AUART_LINECTRL_BAUD_DIVFRAC(v)		(((v) & 0x3f) << 8)
85 #define AUART_LINECTRL_WLEN_MASK		0x00000060
86 #define AUART_LINECTRL_WLEN(v)			(((v) & 0x3) << 5)
87 #define AUART_LINECTRL_FEN			(1 << 4)
88 #define AUART_LINECTRL_STP2			(1 << 3)
89 #define AUART_LINECTRL_EPS			(1 << 2)
90 #define AUART_LINECTRL_PEN			(1 << 1)
91 #define AUART_LINECTRL_BRK			(1 << 0)
92 
93 #define AUART_INTR_RTIEN			(1 << 22)
94 #define AUART_INTR_TXIEN			(1 << 21)
95 #define AUART_INTR_RXIEN			(1 << 20)
96 #define AUART_INTR_CTSMIEN			(1 << 17)
97 #define AUART_INTR_RTIS				(1 << 6)
98 #define AUART_INTR_TXIS				(1 << 5)
99 #define AUART_INTR_RXIS				(1 << 4)
100 #define AUART_INTR_CTSMIS			(1 << 1)
101 
102 #define AUART_STAT_BUSY				(1 << 29)
103 #define AUART_STAT_CTS				(1 << 28)
104 #define AUART_STAT_TXFE				(1 << 27)
105 #define AUART_STAT_TXFF				(1 << 25)
106 #define AUART_STAT_RXFE				(1 << 24)
107 #define AUART_STAT_OERR				(1 << 19)
108 #define AUART_STAT_BERR				(1 << 18)
109 #define AUART_STAT_PERR				(1 << 17)
110 #define AUART_STAT_FERR				(1 << 16)
111 
112 static struct uart_driver auart_driver;
113 
114 struct mxs_auart_port {
115 	struct uart_port port;
116 
117 	unsigned int flags;
118 	unsigned int ctrl;
119 
120 	unsigned int irq;
121 
122 	struct clk *clk;
123 	struct device *dev;
124 };
125 
126 static void mxs_auart_stop_tx(struct uart_port *u);
127 
128 #define to_auart_port(u) container_of(u, struct mxs_auart_port, port)
129 
130 static inline void mxs_auart_tx_chars(struct mxs_auart_port *s)
131 {
132 	struct circ_buf *xmit = &s->port.state->xmit;
133 
134 	while (!(readl(s->port.membase + AUART_STAT) &
135 		 AUART_STAT_TXFF)) {
136 		if (s->port.x_char) {
137 			s->port.icount.tx++;
138 			writel(s->port.x_char,
139 				     s->port.membase + AUART_DATA);
140 			s->port.x_char = 0;
141 			continue;
142 		}
143 		if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
144 			s->port.icount.tx++;
145 			writel(xmit->buf[xmit->tail],
146 				     s->port.membase + AUART_DATA);
147 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
148 		} else
149 			break;
150 	}
151 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
152 		uart_write_wakeup(&s->port);
153 
154 	if (uart_circ_empty(&(s->port.state->xmit)))
155 		writel(AUART_INTR_TXIEN,
156 			     s->port.membase + AUART_INTR_CLR);
157 	else
158 		writel(AUART_INTR_TXIEN,
159 			     s->port.membase + AUART_INTR_SET);
160 
161 	if (uart_tx_stopped(&s->port))
162 		mxs_auart_stop_tx(&s->port);
163 }
164 
165 static void mxs_auart_rx_char(struct mxs_auart_port *s)
166 {
167 	int flag;
168 	u32 stat;
169 	u8 c;
170 
171 	c = readl(s->port.membase + AUART_DATA);
172 	stat = readl(s->port.membase + AUART_STAT);
173 
174 	flag = TTY_NORMAL;
175 	s->port.icount.rx++;
176 
177 	if (stat & AUART_STAT_BERR) {
178 		s->port.icount.brk++;
179 		if (uart_handle_break(&s->port))
180 			goto out;
181 	} else if (stat & AUART_STAT_PERR) {
182 		s->port.icount.parity++;
183 	} else if (stat & AUART_STAT_FERR) {
184 		s->port.icount.frame++;
185 	}
186 
187 	/*
188 	 * Mask off conditions which should be ingored.
189 	 */
190 	stat &= s->port.read_status_mask;
191 
192 	if (stat & AUART_STAT_BERR) {
193 		flag = TTY_BREAK;
194 	} else if (stat & AUART_STAT_PERR)
195 		flag = TTY_PARITY;
196 	else if (stat & AUART_STAT_FERR)
197 		flag = TTY_FRAME;
198 
199 	if (stat & AUART_STAT_OERR)
200 		s->port.icount.overrun++;
201 
202 	if (uart_handle_sysrq_char(&s->port, c))
203 		goto out;
204 
205 	uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag);
206 out:
207 	writel(stat, s->port.membase + AUART_STAT);
208 }
209 
210 static void mxs_auart_rx_chars(struct mxs_auart_port *s)
211 {
212 	struct tty_struct *tty = s->port.state->port.tty;
213 	u32 stat = 0;
214 
215 	for (;;) {
216 		stat = readl(s->port.membase + AUART_STAT);
217 		if (stat & AUART_STAT_RXFE)
218 			break;
219 		mxs_auart_rx_char(s);
220 	}
221 
222 	writel(stat, s->port.membase + AUART_STAT);
223 	tty_flip_buffer_push(tty);
224 }
225 
226 static int mxs_auart_request_port(struct uart_port *u)
227 {
228 	return 0;
229 }
230 
231 static int mxs_auart_verify_port(struct uart_port *u,
232 				    struct serial_struct *ser)
233 {
234 	if (u->type != PORT_UNKNOWN && u->type != PORT_IMX)
235 		return -EINVAL;
236 	return 0;
237 }
238 
239 static void mxs_auart_config_port(struct uart_port *u, int flags)
240 {
241 }
242 
243 static const char *mxs_auart_type(struct uart_port *u)
244 {
245 	struct mxs_auart_port *s = to_auart_port(u);
246 
247 	return dev_name(s->dev);
248 }
249 
250 static void mxs_auart_release_port(struct uart_port *u)
251 {
252 }
253 
254 static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
255 {
256 	struct mxs_auart_port *s = to_auart_port(u);
257 
258 	u32 ctrl = readl(u->membase + AUART_CTRL2);
259 
260 	ctrl &= ~AUART_CTRL2_RTS;
261 	if (mctrl & TIOCM_RTS)
262 		ctrl |= AUART_CTRL2_RTS;
263 	s->ctrl = mctrl;
264 	writel(ctrl, u->membase + AUART_CTRL2);
265 }
266 
267 static u32 mxs_auart_get_mctrl(struct uart_port *u)
268 {
269 	struct mxs_auart_port *s = to_auart_port(u);
270 	u32 stat = readl(u->membase + AUART_STAT);
271 	int ctrl2 = readl(u->membase + AUART_CTRL2);
272 	u32 mctrl = s->ctrl;
273 
274 	mctrl &= ~TIOCM_CTS;
275 	if (stat & AUART_STAT_CTS)
276 		mctrl |= TIOCM_CTS;
277 
278 	if (ctrl2 & AUART_CTRL2_RTS)
279 		mctrl |= TIOCM_RTS;
280 
281 	return mctrl;
282 }
283 
284 static void mxs_auart_settermios(struct uart_port *u,
285 				 struct ktermios *termios,
286 				 struct ktermios *old)
287 {
288 	u32 bm, ctrl, ctrl2, div;
289 	unsigned int cflag, baud;
290 
291 	cflag = termios->c_cflag;
292 
293 	ctrl = AUART_LINECTRL_FEN;
294 	ctrl2 = readl(u->membase + AUART_CTRL2);
295 
296 	/* byte size */
297 	switch (cflag & CSIZE) {
298 	case CS5:
299 		bm = 0;
300 		break;
301 	case CS6:
302 		bm = 1;
303 		break;
304 	case CS7:
305 		bm = 2;
306 		break;
307 	case CS8:
308 		bm = 3;
309 		break;
310 	default:
311 		return;
312 	}
313 
314 	ctrl |= AUART_LINECTRL_WLEN(bm);
315 
316 	/* parity */
317 	if (cflag & PARENB) {
318 		ctrl |= AUART_LINECTRL_PEN;
319 		if ((cflag & PARODD) == 0)
320 			ctrl |= AUART_LINECTRL_EPS;
321 	}
322 
323 	u->read_status_mask = 0;
324 
325 	if (termios->c_iflag & INPCK)
326 		u->read_status_mask |= AUART_STAT_PERR;
327 	if (termios->c_iflag & (BRKINT | PARMRK))
328 		u->read_status_mask |= AUART_STAT_BERR;
329 
330 	/*
331 	 * Characters to ignore
332 	 */
333 	u->ignore_status_mask = 0;
334 	if (termios->c_iflag & IGNPAR)
335 		u->ignore_status_mask |= AUART_STAT_PERR;
336 	if (termios->c_iflag & IGNBRK) {
337 		u->ignore_status_mask |= AUART_STAT_BERR;
338 		/*
339 		 * If we're ignoring parity and break indicators,
340 		 * ignore overruns too (for real raw support).
341 		 */
342 		if (termios->c_iflag & IGNPAR)
343 			u->ignore_status_mask |= AUART_STAT_OERR;
344 	}
345 
346 	/*
347 	 * ignore all characters if CREAD is not set
348 	 */
349 	if (cflag & CREAD)
350 		ctrl2 |= AUART_CTRL2_RXE;
351 	else
352 		ctrl2 &= ~AUART_CTRL2_RXE;
353 
354 	/* figure out the stop bits requested */
355 	if (cflag & CSTOPB)
356 		ctrl |= AUART_LINECTRL_STP2;
357 
358 	/* figure out the hardware flow control settings */
359 	if (cflag & CRTSCTS)
360 		ctrl2 |= AUART_CTRL2_CTSEN;
361 	else
362 		ctrl2 &= ~AUART_CTRL2_CTSEN;
363 
364 	/* set baud rate */
365 	baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk);
366 	div = u->uartclk * 32 / baud;
367 	ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F);
368 	ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6);
369 
370 	writel(ctrl, u->membase + AUART_LINECTRL);
371 	writel(ctrl2, u->membase + AUART_CTRL2);
372 }
373 
374 static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
375 {
376 	u32 istatus, istat;
377 	struct mxs_auart_port *s = context;
378 	u32 stat = readl(s->port.membase + AUART_STAT);
379 
380 	istatus = istat = readl(s->port.membase + AUART_INTR);
381 
382 	if (istat & AUART_INTR_CTSMIS) {
383 		uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS);
384 		writel(AUART_INTR_CTSMIS,
385 				s->port.membase + AUART_INTR_CLR);
386 		istat &= ~AUART_INTR_CTSMIS;
387 	}
388 
389 	if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) {
390 		mxs_auart_rx_chars(s);
391 		istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS);
392 	}
393 
394 	if (istat & AUART_INTR_TXIS) {
395 		mxs_auart_tx_chars(s);
396 		istat &= ~AUART_INTR_TXIS;
397 	}
398 
399 	writel(istatus & (AUART_INTR_RTIS
400 		| AUART_INTR_TXIS
401 		| AUART_INTR_RXIS
402 		| AUART_INTR_CTSMIS),
403 			s->port.membase + AUART_INTR_CLR);
404 
405 	return IRQ_HANDLED;
406 }
407 
408 static void mxs_auart_reset(struct uart_port *u)
409 {
410 	int i;
411 	unsigned int reg;
412 
413 	writel(AUART_CTRL0_SFTRST, u->membase + AUART_CTRL0_CLR);
414 
415 	for (i = 0; i < 10000; i++) {
416 		reg = readl(u->membase + AUART_CTRL0);
417 		if (!(reg & AUART_CTRL0_SFTRST))
418 			break;
419 		udelay(3);
420 	}
421 	writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
422 }
423 
424 static int mxs_auart_startup(struct uart_port *u)
425 {
426 	struct mxs_auart_port *s = to_auart_port(u);
427 
428 	clk_prepare_enable(s->clk);
429 
430 	writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
431 
432 	writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_SET);
433 
434 	writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
435 			u->membase + AUART_INTR);
436 
437 	/*
438 	 * Enable fifo so all four bytes of a DMA word are written to
439 	 * output (otherwise, only the LSB is written, ie. 1 in 4 bytes)
440 	 */
441 	writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET);
442 
443 	return 0;
444 }
445 
446 static void mxs_auart_shutdown(struct uart_port *u)
447 {
448 	struct mxs_auart_port *s = to_auart_port(u);
449 
450 	writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR);
451 
452 	writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET);
453 
454 	writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
455 			u->membase + AUART_INTR_CLR);
456 
457 	clk_disable_unprepare(s->clk);
458 }
459 
460 static unsigned int mxs_auart_tx_empty(struct uart_port *u)
461 {
462 	if (readl(u->membase + AUART_STAT) & AUART_STAT_TXFE)
463 		return TIOCSER_TEMT;
464 	else
465 		return 0;
466 }
467 
468 static void mxs_auart_start_tx(struct uart_port *u)
469 {
470 	struct mxs_auart_port *s = to_auart_port(u);
471 
472 	/* enable transmitter */
473 	writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_SET);
474 
475 	mxs_auart_tx_chars(s);
476 }
477 
478 static void mxs_auart_stop_tx(struct uart_port *u)
479 {
480 	writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_CLR);
481 }
482 
483 static void mxs_auart_stop_rx(struct uart_port *u)
484 {
485 	writel(AUART_CTRL2_RXE, u->membase + AUART_CTRL2_CLR);
486 }
487 
488 static void mxs_auart_break_ctl(struct uart_port *u, int ctl)
489 {
490 	if (ctl)
491 		writel(AUART_LINECTRL_BRK,
492 			     u->membase + AUART_LINECTRL_SET);
493 	else
494 		writel(AUART_LINECTRL_BRK,
495 			     u->membase + AUART_LINECTRL_CLR);
496 }
497 
498 static void mxs_auart_enable_ms(struct uart_port *port)
499 {
500 	/* just empty */
501 }
502 
503 static struct uart_ops mxs_auart_ops = {
504 	.tx_empty       = mxs_auart_tx_empty,
505 	.start_tx       = mxs_auart_start_tx,
506 	.stop_tx	= mxs_auart_stop_tx,
507 	.stop_rx	= mxs_auart_stop_rx,
508 	.enable_ms      = mxs_auart_enable_ms,
509 	.break_ctl      = mxs_auart_break_ctl,
510 	.set_mctrl	= mxs_auart_set_mctrl,
511 	.get_mctrl      = mxs_auart_get_mctrl,
512 	.startup	= mxs_auart_startup,
513 	.shutdown       = mxs_auart_shutdown,
514 	.set_termios    = mxs_auart_settermios,
515 	.type	   	= mxs_auart_type,
516 	.release_port   = mxs_auart_release_port,
517 	.request_port   = mxs_auart_request_port,
518 	.config_port    = mxs_auart_config_port,
519 	.verify_port    = mxs_auart_verify_port,
520 };
521 
522 static struct mxs_auart_port *auart_port[MXS_AUART_PORTS];
523 
524 #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
525 static void mxs_auart_console_putchar(struct uart_port *port, int ch)
526 {
527 	unsigned int to = 1000;
528 
529 	while (readl(port->membase + AUART_STAT) & AUART_STAT_TXFF) {
530 		if (!to--)
531 			break;
532 		udelay(1);
533 	}
534 
535 	writel(ch, port->membase + AUART_DATA);
536 }
537 
538 static void
539 auart_console_write(struct console *co, const char *str, unsigned int count)
540 {
541 	struct mxs_auart_port *s;
542 	struct uart_port *port;
543 	unsigned int old_ctrl0, old_ctrl2;
544 	unsigned int to = 1000;
545 
546 	if (co->index >	MXS_AUART_PORTS || co->index < 0)
547 		return;
548 
549 	s = auart_port[co->index];
550 	port = &s->port;
551 
552 	clk_enable(s->clk);
553 
554 	/* First save the CR then disable the interrupts */
555 	old_ctrl2 = readl(port->membase + AUART_CTRL2);
556 	old_ctrl0 = readl(port->membase + AUART_CTRL0);
557 
558 	writel(AUART_CTRL0_CLKGATE,
559 		     port->membase + AUART_CTRL0_CLR);
560 	writel(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE,
561 		     port->membase + AUART_CTRL2_SET);
562 
563 	uart_console_write(port, str, count, mxs_auart_console_putchar);
564 
565 	/*
566 	 * Finally, wait for transmitter to become empty
567 	 * and restore the TCR
568 	 */
569 	while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) {
570 		if (!to--)
571 			break;
572 		udelay(1);
573 	}
574 
575 	writel(old_ctrl0, port->membase + AUART_CTRL0);
576 	writel(old_ctrl2, port->membase + AUART_CTRL2);
577 
578 	clk_disable(s->clk);
579 }
580 
581 static void __init
582 auart_console_get_options(struct uart_port *port, int *baud,
583 			  int *parity, int *bits)
584 {
585 	unsigned int lcr_h, quot;
586 
587 	if (!(readl(port->membase + AUART_CTRL2) & AUART_CTRL2_UARTEN))
588 		return;
589 
590 	lcr_h = readl(port->membase + AUART_LINECTRL);
591 
592 	*parity = 'n';
593 	if (lcr_h & AUART_LINECTRL_PEN) {
594 		if (lcr_h & AUART_LINECTRL_EPS)
595 			*parity = 'e';
596 		else
597 			*parity = 'o';
598 	}
599 
600 	if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2))
601 		*bits = 7;
602 	else
603 		*bits = 8;
604 
605 	quot = ((readl(port->membase + AUART_LINECTRL)
606 			& AUART_LINECTRL_BAUD_DIVINT_MASK))
607 			    >> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6);
608 	quot |= ((readl(port->membase + AUART_LINECTRL)
609 			& AUART_LINECTRL_BAUD_DIVFRAC_MASK))
610 				>> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT;
611 	if (quot == 0)
612 		quot = 1;
613 
614 	*baud = (port->uartclk << 2) / quot;
615 }
616 
617 static int __init
618 auart_console_setup(struct console *co, char *options)
619 {
620 	struct mxs_auart_port *s;
621 	int baud = 9600;
622 	int bits = 8;
623 	int parity = 'n';
624 	int flow = 'n';
625 	int ret;
626 
627 	/*
628 	 * Check whether an invalid uart number has been specified, and
629 	 * if so, search for the first available port that does have
630 	 * console support.
631 	 */
632 	if (co->index == -1 || co->index >= ARRAY_SIZE(auart_port))
633 		co->index = 0;
634 	s = auart_port[co->index];
635 	if (!s)
636 		return -ENODEV;
637 
638 	clk_prepare_enable(s->clk);
639 
640 	if (options)
641 		uart_parse_options(options, &baud, &parity, &bits, &flow);
642 	else
643 		auart_console_get_options(&s->port, &baud, &parity, &bits);
644 
645 	ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
646 
647 	clk_disable_unprepare(s->clk);
648 
649 	return ret;
650 }
651 
652 static struct console auart_console = {
653 	.name		= "ttyAPP",
654 	.write		= auart_console_write,
655 	.device		= uart_console_device,
656 	.setup		= auart_console_setup,
657 	.flags		= CON_PRINTBUFFER,
658 	.index		= -1,
659 	.data		= &auart_driver,
660 };
661 #endif
662 
663 static struct uart_driver auart_driver = {
664 	.owner		= THIS_MODULE,
665 	.driver_name	= "ttyAPP",
666 	.dev_name	= "ttyAPP",
667 	.major		= 0,
668 	.minor		= 0,
669 	.nr		= MXS_AUART_PORTS,
670 #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
671 	.cons =		&auart_console,
672 #endif
673 };
674 
675 static int __devinit mxs_auart_probe(struct platform_device *pdev)
676 {
677 	struct mxs_auart_port *s;
678 	u32 version;
679 	int ret = 0;
680 	struct resource *r;
681 
682 	s = kzalloc(sizeof(struct mxs_auart_port), GFP_KERNEL);
683 	if (!s) {
684 		ret = -ENOMEM;
685 		goto out;
686 	}
687 
688 	s->clk = clk_get(&pdev->dev, NULL);
689 	if (IS_ERR(s->clk)) {
690 		ret = PTR_ERR(s->clk);
691 		goto out_free;
692 	}
693 
694 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
695 	if (!r) {
696 		ret = -ENXIO;
697 		goto out_free_clk;
698 	}
699 
700 	s->port.mapbase = r->start;
701 	s->port.membase = ioremap(r->start, resource_size(r));
702 	s->port.ops = &mxs_auart_ops;
703 	s->port.iotype = UPIO_MEM;
704 	s->port.line = pdev->id < 0 ? 0 : pdev->id;
705 	s->port.fifosize = 16;
706 	s->port.uartclk = clk_get_rate(s->clk);
707 	s->port.type = PORT_IMX;
708 	s->port.dev = s->dev = get_device(&pdev->dev);
709 
710 	s->flags = 0;
711 	s->ctrl = 0;
712 
713 	s->irq = platform_get_irq(pdev, 0);
714 	s->port.irq = s->irq;
715 	ret = request_irq(s->irq, mxs_auart_irq_handle, 0, dev_name(&pdev->dev), s);
716 	if (ret)
717 		goto out_free_clk;
718 
719 	platform_set_drvdata(pdev, s);
720 
721 	auart_port[pdev->id] = s;
722 
723 	mxs_auart_reset(&s->port);
724 
725 	ret = uart_add_one_port(&auart_driver, &s->port);
726 	if (ret)
727 		goto out_free_irq;
728 
729 	version = readl(s->port.membase + AUART_VERSION);
730 	dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n",
731 	       (version >> 24) & 0xff,
732 	       (version >> 16) & 0xff, version & 0xffff);
733 
734 	return 0;
735 
736 out_free_irq:
737 	auart_port[pdev->id] = NULL;
738 	free_irq(s->irq, s);
739 out_free_clk:
740 	clk_put(s->clk);
741 out_free:
742 	kfree(s);
743 out:
744 	return ret;
745 }
746 
747 static int __devexit mxs_auart_remove(struct platform_device *pdev)
748 {
749 	struct mxs_auart_port *s = platform_get_drvdata(pdev);
750 
751 	uart_remove_one_port(&auart_driver, &s->port);
752 
753 	auart_port[pdev->id] = NULL;
754 
755 	clk_put(s->clk);
756 	free_irq(s->irq, s);
757 	kfree(s);
758 
759 	return 0;
760 }
761 
762 static struct platform_driver mxs_auart_driver = {
763 	.probe = mxs_auart_probe,
764 	.remove = __devexit_p(mxs_auart_remove),
765 	.driver = {
766 		.name = "mxs-auart",
767 		.owner = THIS_MODULE,
768 	},
769 };
770 
771 static int __init mxs_auart_init(void)
772 {
773 	int r;
774 
775 	r = uart_register_driver(&auart_driver);
776 	if (r)
777 		goto out;
778 
779 	r = platform_driver_register(&mxs_auart_driver);
780 	if (r)
781 		goto out_err;
782 
783 	return 0;
784 out_err:
785 	uart_unregister_driver(&auart_driver);
786 out:
787 	return r;
788 }
789 
790 static void __exit mxs_auart_exit(void)
791 {
792 	platform_driver_unregister(&mxs_auart_driver);
793 	uart_unregister_driver(&auart_driver);
794 }
795 
796 module_init(mxs_auart_init);
797 module_exit(mxs_auart_exit);
798 MODULE_LICENSE("GPL");
799 MODULE_DESCRIPTION("Freescale MXS application uart driver");
800