xref: /openbmc/linux/drivers/tty/serial/imx.c (revision 615c36f5)
1 /*
2  *  Driver for Motorola IMX serial ports
3  *
4  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5  *
6  *  Author: Sascha Hauer <sascha@saschahauer.de>
7  *  Copyright (C) 2004 Pengutronix
8  *
9  *  Copyright (C) 2009 emlix GmbH
10  *  Author: Fabian Godehardt (added IrDA support for iMX)
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  * [29-Mar-2005] Mike Lee
27  * Added hardware handshake
28  */
29 
30 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
31 #define SUPPORT_SYSRQ
32 #endif
33 
34 #include <linux/module.h>
35 #include <linux/ioport.h>
36 #include <linux/init.h>
37 #include <linux/console.h>
38 #include <linux/sysrq.h>
39 #include <linux/platform_device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/serial.h>
44 #include <linux/clk.h>
45 #include <linux/delay.h>
46 #include <linux/rational.h>
47 #include <linux/slab.h>
48 #include <linux/of.h>
49 #include <linux/of_device.h>
50 
51 #include <asm/io.h>
52 #include <asm/irq.h>
53 #include <mach/imx-uart.h>
54 
55 /* Register definitions */
56 #define URXD0 0x0  /* Receiver Register */
57 #define URTX0 0x40 /* Transmitter Register */
58 #define UCR1  0x80 /* Control Register 1 */
59 #define UCR2  0x84 /* Control Register 2 */
60 #define UCR3  0x88 /* Control Register 3 */
61 #define UCR4  0x8c /* Control Register 4 */
62 #define UFCR  0x90 /* FIFO Control Register */
63 #define USR1  0x94 /* Status Register 1 */
64 #define USR2  0x98 /* Status Register 2 */
65 #define UESC  0x9c /* Escape Character Register */
66 #define UTIM  0xa0 /* Escape Timer Register */
67 #define UBIR  0xa4 /* BRM Incremental Register */
68 #define UBMR  0xa8 /* BRM Modulator Register */
69 #define UBRC  0xac /* Baud Rate Count Register */
70 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
71 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
72 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
73 
74 /* UART Control Register Bit Fields.*/
75 #define  URXD_CHARRDY    (1<<15)
76 #define  URXD_ERR        (1<<14)
77 #define  URXD_OVRRUN     (1<<13)
78 #define  URXD_FRMERR     (1<<12)
79 #define  URXD_BRK        (1<<11)
80 #define  URXD_PRERR      (1<<10)
81 #define  UCR1_ADEN       (1<<15) /* Auto detect interrupt */
82 #define  UCR1_ADBR       (1<<14) /* Auto detect baud rate */
83 #define  UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
84 #define  UCR1_IDEN       (1<<12) /* Idle condition interrupt */
85 #define  UCR1_RRDYEN     (1<<9)	 /* Recv ready interrupt enable */
86 #define  UCR1_RDMAEN     (1<<8)	 /* Recv ready DMA enable */
87 #define  UCR1_IREN       (1<<7)	 /* Infrared interface enable */
88 #define  UCR1_TXMPTYEN   (1<<6)	 /* Transimitter empty interrupt enable */
89 #define  UCR1_RTSDEN     (1<<5)	 /* RTS delta interrupt enable */
90 #define  UCR1_SNDBRK     (1<<4)	 /* Send break */
91 #define  UCR1_TDMAEN     (1<<3)	 /* Transmitter ready DMA enable */
92 #define  IMX1_UCR1_UARTCLKEN  (1<<2)  /* UART clock enabled, i.mx1 only */
93 #define  UCR1_DOZE       (1<<1)	 /* Doze */
94 #define  UCR1_UARTEN     (1<<0)	 /* UART enabled */
95 #define  UCR2_ESCI     	 (1<<15) /* Escape seq interrupt enable */
96 #define  UCR2_IRTS  	 (1<<14) /* Ignore RTS pin */
97 #define  UCR2_CTSC  	 (1<<13) /* CTS pin control */
98 #define  UCR2_CTS        (1<<12) /* Clear to send */
99 #define  UCR2_ESCEN      (1<<11) /* Escape enable */
100 #define  UCR2_PREN       (1<<8)  /* Parity enable */
101 #define  UCR2_PROE       (1<<7)  /* Parity odd/even */
102 #define  UCR2_STPB       (1<<6)	 /* Stop */
103 #define  UCR2_WS         (1<<5)	 /* Word size */
104 #define  UCR2_RTSEN      (1<<4)	 /* Request to send interrupt enable */
105 #define  UCR2_TXEN       (1<<2)	 /* Transmitter enabled */
106 #define  UCR2_RXEN       (1<<1)	 /* Receiver enabled */
107 #define  UCR2_SRST 	 (1<<0)	 /* SW reset */
108 #define  UCR3_DTREN 	 (1<<13) /* DTR interrupt enable */
109 #define  UCR3_PARERREN   (1<<12) /* Parity enable */
110 #define  UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
111 #define  UCR3_DSR        (1<<10) /* Data set ready */
112 #define  UCR3_DCD        (1<<9)  /* Data carrier detect */
113 #define  UCR3_RI         (1<<8)  /* Ring indicator */
114 #define  UCR3_TIMEOUTEN  (1<<7)  /* Timeout interrupt enable */
115 #define  UCR3_RXDSEN	 (1<<6)  /* Receive status interrupt enable */
116 #define  UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
117 #define  UCR3_AWAKEN	 (1<<4)  /* Async wake interrupt enable */
118 #define  IMX21_UCR3_RXDMUXSEL	 (1<<2)  /* RXD Muxed Input Select */
119 #define  UCR3_INVT  	 (1<<1)  /* Inverted Infrared transmission */
120 #define  UCR3_BPEN  	 (1<<0)  /* Preset registers enable */
121 #define  UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
122 #define  UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
123 #define  UCR4_INVR  	 (1<<9)  /* Inverted infrared reception */
124 #define  UCR4_ENIRI 	 (1<<8)  /* Serial infrared interrupt enable */
125 #define  UCR4_WKEN  	 (1<<7)  /* Wake interrupt enable */
126 #define  UCR4_REF16 	 (1<<6)  /* Ref freq 16 MHz */
127 #define  UCR4_IRSC  	 (1<<5)  /* IR special case */
128 #define  UCR4_TCEN  	 (1<<3)  /* Transmit complete interrupt enable */
129 #define  UCR4_BKEN  	 (1<<2)  /* Break condition interrupt enable */
130 #define  UCR4_OREN  	 (1<<1)  /* Receiver overrun interrupt enable */
131 #define  UCR4_DREN  	 (1<<0)  /* Recv data ready interrupt enable */
132 #define  UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
133 #define  UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
134 #define  UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
135 #define  UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
136 #define  USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
137 #define  USR1_RTSS  	 (1<<14) /* RTS pin status */
138 #define  USR1_TRDY  	 (1<<13) /* Transmitter ready interrupt/dma flag */
139 #define  USR1_RTSD  	 (1<<12) /* RTS delta */
140 #define  USR1_ESCF  	 (1<<11) /* Escape seq interrupt flag */
141 #define  USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
142 #define  USR1_RRDY       (1<<9)	 /* Receiver ready interrupt/dma flag */
143 #define  USR1_TIMEOUT    (1<<7)	 /* Receive timeout interrupt status */
144 #define  USR1_RXDS  	 (1<<6)	 /* Receiver idle interrupt flag */
145 #define  USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
146 #define  USR1_AWAKE 	 (1<<4)	 /* Aysnc wake interrupt flag */
147 #define  USR2_ADET  	 (1<<15) /* Auto baud rate detect complete */
148 #define  USR2_TXFE  	 (1<<14) /* Transmit buffer FIFO empty */
149 #define  USR2_DTRF  	 (1<<13) /* DTR edge interrupt flag */
150 #define  USR2_IDLE  	 (1<<12) /* Idle condition */
151 #define  USR2_IRINT 	 (1<<8)	 /* Serial infrared interrupt flag */
152 #define  USR2_WAKE  	 (1<<7)	 /* Wake */
153 #define  USR2_RTSF  	 (1<<4)	 /* RTS edge interrupt flag */
154 #define  USR2_TXDC  	 (1<<3)	 /* Transmitter complete */
155 #define  USR2_BRCD  	 (1<<2)	 /* Break condition */
156 #define  USR2_ORE        (1<<1)	 /* Overrun error */
157 #define  USR2_RDR        (1<<0)	 /* Recv data ready */
158 #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
159 #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
160 #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
161 #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
162 #define  UTS_TXFULL 	 (1<<4)	 /* TxFIFO full */
163 #define  UTS_RXFULL 	 (1<<3)	 /* RxFIFO full */
164 #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
165 
166 /* We've been assigned a range on the "Low-density serial ports" major */
167 #define SERIAL_IMX_MAJOR        207
168 #define MINOR_START	        16
169 #define DEV_NAME		"ttymxc"
170 #define MAX_INTERNAL_IRQ	MXC_INTERNAL_IRQS
171 
172 /*
173  * This determines how often we check the modem status signals
174  * for any change.  They generally aren't connected to an IRQ
175  * so we have to poll them.  We also check immediately before
176  * filling the TX fifo incase CTS has been dropped.
177  */
178 #define MCTRL_TIMEOUT	(250*HZ/1000)
179 
180 #define DRIVER_NAME "IMX-uart"
181 
182 #define UART_NR 8
183 
184 /* i.mx21 type uart runs on all i.mx except i.mx1 */
185 enum imx_uart_type {
186 	IMX1_UART,
187 	IMX21_UART,
188 };
189 
190 /* device type dependent stuff */
191 struct imx_uart_data {
192 	unsigned uts_reg;
193 	enum imx_uart_type devtype;
194 };
195 
196 struct imx_port {
197 	struct uart_port	port;
198 	struct timer_list	timer;
199 	unsigned int		old_status;
200 	int			txirq,rxirq,rtsirq;
201 	unsigned int		have_rtscts:1;
202 	unsigned int		use_irda:1;
203 	unsigned int		irda_inv_rx:1;
204 	unsigned int		irda_inv_tx:1;
205 	unsigned short		trcv_delay; /* transceiver delay */
206 	struct clk		*clk;
207 	struct imx_uart_data	*devdata;
208 };
209 
210 #ifdef CONFIG_IRDA
211 #define USE_IRDA(sport)	((sport)->use_irda)
212 #else
213 #define USE_IRDA(sport)	(0)
214 #endif
215 
216 static struct imx_uart_data imx_uart_devdata[] = {
217 	[IMX1_UART] = {
218 		.uts_reg = IMX1_UTS,
219 		.devtype = IMX1_UART,
220 	},
221 	[IMX21_UART] = {
222 		.uts_reg = IMX21_UTS,
223 		.devtype = IMX21_UART,
224 	},
225 };
226 
227 static struct platform_device_id imx_uart_devtype[] = {
228 	{
229 		.name = "imx1-uart",
230 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
231 	}, {
232 		.name = "imx21-uart",
233 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
234 	}, {
235 		/* sentinel */
236 	}
237 };
238 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
239 
240 static struct of_device_id imx_uart_dt_ids[] = {
241 	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
242 	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
243 	{ /* sentinel */ }
244 };
245 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
246 
247 static inline unsigned uts_reg(struct imx_port *sport)
248 {
249 	return sport->devdata->uts_reg;
250 }
251 
252 static inline int is_imx1_uart(struct imx_port *sport)
253 {
254 	return sport->devdata->devtype == IMX1_UART;
255 }
256 
257 static inline int is_imx21_uart(struct imx_port *sport)
258 {
259 	return sport->devdata->devtype == IMX21_UART;
260 }
261 
262 /*
263  * Handle any change of modem status signal since we were last called.
264  */
265 static void imx_mctrl_check(struct imx_port *sport)
266 {
267 	unsigned int status, changed;
268 
269 	status = sport->port.ops->get_mctrl(&sport->port);
270 	changed = status ^ sport->old_status;
271 
272 	if (changed == 0)
273 		return;
274 
275 	sport->old_status = status;
276 
277 	if (changed & TIOCM_RI)
278 		sport->port.icount.rng++;
279 	if (changed & TIOCM_DSR)
280 		sport->port.icount.dsr++;
281 	if (changed & TIOCM_CAR)
282 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
283 	if (changed & TIOCM_CTS)
284 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
285 
286 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
287 }
288 
289 /*
290  * This is our per-port timeout handler, for checking the
291  * modem status signals.
292  */
293 static void imx_timeout(unsigned long data)
294 {
295 	struct imx_port *sport = (struct imx_port *)data;
296 	unsigned long flags;
297 
298 	if (sport->port.state) {
299 		spin_lock_irqsave(&sport->port.lock, flags);
300 		imx_mctrl_check(sport);
301 		spin_unlock_irqrestore(&sport->port.lock, flags);
302 
303 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
304 	}
305 }
306 
307 /*
308  * interrupts disabled on entry
309  */
310 static void imx_stop_tx(struct uart_port *port)
311 {
312 	struct imx_port *sport = (struct imx_port *)port;
313 	unsigned long temp;
314 
315 	if (USE_IRDA(sport)) {
316 		/* half duplex - wait for end of transmission */
317 		int n = 256;
318 		while ((--n > 0) &&
319 		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
320 			udelay(5);
321 			barrier();
322 		}
323 		/*
324 		 * irda transceiver - wait a bit more to avoid
325 		 * cutoff, hardware dependent
326 		 */
327 		udelay(sport->trcv_delay);
328 
329 		/*
330 		 * half duplex - reactivate receive mode,
331 		 * flush receive pipe echo crap
332 		 */
333 		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
334 			temp = readl(sport->port.membase + UCR1);
335 			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
336 			writel(temp, sport->port.membase + UCR1);
337 
338 			temp = readl(sport->port.membase + UCR4);
339 			temp &= ~(UCR4_TCEN);
340 			writel(temp, sport->port.membase + UCR4);
341 
342 			while (readl(sport->port.membase + URXD0) &
343 			       URXD_CHARRDY)
344 				barrier();
345 
346 			temp = readl(sport->port.membase + UCR1);
347 			temp |= UCR1_RRDYEN;
348 			writel(temp, sport->port.membase + UCR1);
349 
350 			temp = readl(sport->port.membase + UCR4);
351 			temp |= UCR4_DREN;
352 			writel(temp, sport->port.membase + UCR4);
353 		}
354 		return;
355 	}
356 
357 	temp = readl(sport->port.membase + UCR1);
358 	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
359 }
360 
361 /*
362  * interrupts disabled on entry
363  */
364 static void imx_stop_rx(struct uart_port *port)
365 {
366 	struct imx_port *sport = (struct imx_port *)port;
367 	unsigned long temp;
368 
369 	temp = readl(sport->port.membase + UCR2);
370 	writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
371 }
372 
373 /*
374  * Set the modem control timer to fire immediately.
375  */
376 static void imx_enable_ms(struct uart_port *port)
377 {
378 	struct imx_port *sport = (struct imx_port *)port;
379 
380 	mod_timer(&sport->timer, jiffies);
381 }
382 
383 static inline void imx_transmit_buffer(struct imx_port *sport)
384 {
385 	struct circ_buf *xmit = &sport->port.state->xmit;
386 
387 	while (!uart_circ_empty(xmit) &&
388 			!(readl(sport->port.membase + uts_reg(sport))
389 				& UTS_TXFULL)) {
390 		/* send xmit->buf[xmit->tail]
391 		 * out the port here */
392 		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
393 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
394 		sport->port.icount.tx++;
395 	}
396 
397 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
398 		uart_write_wakeup(&sport->port);
399 
400 	if (uart_circ_empty(xmit))
401 		imx_stop_tx(&sport->port);
402 }
403 
404 /*
405  * interrupts disabled on entry
406  */
407 static void imx_start_tx(struct uart_port *port)
408 {
409 	struct imx_port *sport = (struct imx_port *)port;
410 	unsigned long temp;
411 
412 	if (USE_IRDA(sport)) {
413 		/* half duplex in IrDA mode; have to disable receive mode */
414 		temp = readl(sport->port.membase + UCR4);
415 		temp &= ~(UCR4_DREN);
416 		writel(temp, sport->port.membase + UCR4);
417 
418 		temp = readl(sport->port.membase + UCR1);
419 		temp &= ~(UCR1_RRDYEN);
420 		writel(temp, sport->port.membase + UCR1);
421 	}
422 
423 	temp = readl(sport->port.membase + UCR1);
424 	writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
425 
426 	if (USE_IRDA(sport)) {
427 		temp = readl(sport->port.membase + UCR1);
428 		temp |= UCR1_TRDYEN;
429 		writel(temp, sport->port.membase + UCR1);
430 
431 		temp = readl(sport->port.membase + UCR4);
432 		temp |= UCR4_TCEN;
433 		writel(temp, sport->port.membase + UCR4);
434 	}
435 
436 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
437 		imx_transmit_buffer(sport);
438 }
439 
440 static irqreturn_t imx_rtsint(int irq, void *dev_id)
441 {
442 	struct imx_port *sport = dev_id;
443 	unsigned int val;
444 	unsigned long flags;
445 
446 	spin_lock_irqsave(&sport->port.lock, flags);
447 
448 	writel(USR1_RTSD, sport->port.membase + USR1);
449 	val = readl(sport->port.membase + USR1) & USR1_RTSS;
450 	uart_handle_cts_change(&sport->port, !!val);
451 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
452 
453 	spin_unlock_irqrestore(&sport->port.lock, flags);
454 	return IRQ_HANDLED;
455 }
456 
457 static irqreturn_t imx_txint(int irq, void *dev_id)
458 {
459 	struct imx_port *sport = dev_id;
460 	struct circ_buf *xmit = &sport->port.state->xmit;
461 	unsigned long flags;
462 
463 	spin_lock_irqsave(&sport->port.lock,flags);
464 	if (sport->port.x_char)
465 	{
466 		/* Send next char */
467 		writel(sport->port.x_char, sport->port.membase + URTX0);
468 		goto out;
469 	}
470 
471 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
472 		imx_stop_tx(&sport->port);
473 		goto out;
474 	}
475 
476 	imx_transmit_buffer(sport);
477 
478 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
479 		uart_write_wakeup(&sport->port);
480 
481 out:
482 	spin_unlock_irqrestore(&sport->port.lock,flags);
483 	return IRQ_HANDLED;
484 }
485 
486 static irqreturn_t imx_rxint(int irq, void *dev_id)
487 {
488 	struct imx_port *sport = dev_id;
489 	unsigned int rx,flg,ignored = 0;
490 	struct tty_struct *tty = sport->port.state->port.tty;
491 	unsigned long flags, temp;
492 
493 	spin_lock_irqsave(&sport->port.lock,flags);
494 
495 	while (readl(sport->port.membase + USR2) & USR2_RDR) {
496 		flg = TTY_NORMAL;
497 		sport->port.icount.rx++;
498 
499 		rx = readl(sport->port.membase + URXD0);
500 
501 		temp = readl(sport->port.membase + USR2);
502 		if (temp & USR2_BRCD) {
503 			writel(USR2_BRCD, sport->port.membase + USR2);
504 			if (uart_handle_break(&sport->port))
505 				continue;
506 		}
507 
508 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
509 			continue;
510 
511 		if (unlikely(rx & URXD_ERR)) {
512 			if (rx & URXD_BRK)
513 				sport->port.icount.brk++;
514 			else if (rx & URXD_PRERR)
515 				sport->port.icount.parity++;
516 			else if (rx & URXD_FRMERR)
517 				sport->port.icount.frame++;
518 			if (rx & URXD_OVRRUN)
519 				sport->port.icount.overrun++;
520 
521 			if (rx & sport->port.ignore_status_mask) {
522 				if (++ignored > 100)
523 					goto out;
524 				continue;
525 			}
526 
527 			rx &= sport->port.read_status_mask;
528 
529 			if (rx & URXD_BRK)
530 				flg = TTY_BREAK;
531 			else if (rx & URXD_PRERR)
532 				flg = TTY_PARITY;
533 			else if (rx & URXD_FRMERR)
534 				flg = TTY_FRAME;
535 			if (rx & URXD_OVRRUN)
536 				flg = TTY_OVERRUN;
537 
538 #ifdef SUPPORT_SYSRQ
539 			sport->port.sysrq = 0;
540 #endif
541 		}
542 
543 		tty_insert_flip_char(tty, rx, flg);
544 	}
545 
546 out:
547 	spin_unlock_irqrestore(&sport->port.lock,flags);
548 	tty_flip_buffer_push(tty);
549 	return IRQ_HANDLED;
550 }
551 
552 static irqreturn_t imx_int(int irq, void *dev_id)
553 {
554 	struct imx_port *sport = dev_id;
555 	unsigned int sts;
556 
557 	sts = readl(sport->port.membase + USR1);
558 
559 	if (sts & USR1_RRDY)
560 		imx_rxint(irq, dev_id);
561 
562 	if (sts & USR1_TRDY &&
563 			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
564 		imx_txint(irq, dev_id);
565 
566 	if (sts & USR1_RTSD)
567 		imx_rtsint(irq, dev_id);
568 
569 	return IRQ_HANDLED;
570 }
571 
572 /*
573  * Return TIOCSER_TEMT when transmitter is not busy.
574  */
575 static unsigned int imx_tx_empty(struct uart_port *port)
576 {
577 	struct imx_port *sport = (struct imx_port *)port;
578 
579 	return (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
580 }
581 
582 /*
583  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
584  */
585 static unsigned int imx_get_mctrl(struct uart_port *port)
586 {
587 	struct imx_port *sport = (struct imx_port *)port;
588 	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
589 
590 	if (readl(sport->port.membase + USR1) & USR1_RTSS)
591 		tmp |= TIOCM_CTS;
592 
593 	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
594 		tmp |= TIOCM_RTS;
595 
596 	return tmp;
597 }
598 
599 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
600 {
601 	struct imx_port *sport = (struct imx_port *)port;
602 	unsigned long temp;
603 
604 	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
605 
606 	if (mctrl & TIOCM_RTS)
607 		temp |= UCR2_CTS;
608 
609 	writel(temp, sport->port.membase + UCR2);
610 }
611 
612 /*
613  * Interrupts always disabled.
614  */
615 static void imx_break_ctl(struct uart_port *port, int break_state)
616 {
617 	struct imx_port *sport = (struct imx_port *)port;
618 	unsigned long flags, temp;
619 
620 	spin_lock_irqsave(&sport->port.lock, flags);
621 
622 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
623 
624 	if ( break_state != 0 )
625 		temp |= UCR1_SNDBRK;
626 
627 	writel(temp, sport->port.membase + UCR1);
628 
629 	spin_unlock_irqrestore(&sport->port.lock, flags);
630 }
631 
632 #define TXTL 2 /* reset default */
633 #define RXTL 1 /* reset default */
634 
635 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
636 {
637 	unsigned int val;
638 	unsigned int ufcr_rfdiv;
639 
640 	/* set receiver / transmitter trigger level.
641 	 * RFDIV is set such way to satisfy requested uartclk value
642 	 */
643 	val = TXTL << 10 | RXTL;
644 	ufcr_rfdiv = (clk_get_rate(sport->clk) + sport->port.uartclk / 2)
645 			/ sport->port.uartclk;
646 
647 	if(!ufcr_rfdiv)
648 		ufcr_rfdiv = 1;
649 
650 	val |= UFCR_RFDIV_REG(ufcr_rfdiv);
651 
652 	writel(val, sport->port.membase + UFCR);
653 
654 	return 0;
655 }
656 
657 /* half the RX buffer size */
658 #define CTSTL 16
659 
660 static int imx_startup(struct uart_port *port)
661 {
662 	struct imx_port *sport = (struct imx_port *)port;
663 	int retval;
664 	unsigned long flags, temp;
665 
666 	imx_setup_ufcr(sport, 0);
667 
668 	/* disable the DREN bit (Data Ready interrupt enable) before
669 	 * requesting IRQs
670 	 */
671 	temp = readl(sport->port.membase + UCR4);
672 
673 	if (USE_IRDA(sport))
674 		temp |= UCR4_IRSC;
675 
676 	/* set the trigger level for CTS */
677 	temp &= ~(UCR4_CTSTL_MASK<<  UCR4_CTSTL_SHF);
678 	temp |= CTSTL<<  UCR4_CTSTL_SHF;
679 
680 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
681 
682 	if (USE_IRDA(sport)) {
683 		/* reset fifo's and state machines */
684 		int i = 100;
685 		temp = readl(sport->port.membase + UCR2);
686 		temp &= ~UCR2_SRST;
687 		writel(temp, sport->port.membase + UCR2);
688 		while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
689 		    (--i > 0)) {
690 			udelay(1);
691 		}
692 	}
693 
694 	/*
695 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
696 	 * chips only have one interrupt.
697 	 */
698 	if (sport->txirq > 0) {
699 		retval = request_irq(sport->rxirq, imx_rxint, 0,
700 				DRIVER_NAME, sport);
701 		if (retval)
702 			goto error_out1;
703 
704 		retval = request_irq(sport->txirq, imx_txint, 0,
705 				DRIVER_NAME, sport);
706 		if (retval)
707 			goto error_out2;
708 
709 		/* do not use RTS IRQ on IrDA */
710 		if (!USE_IRDA(sport)) {
711 			retval = request_irq(sport->rtsirq, imx_rtsint,
712 				     (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
713 				       IRQF_TRIGGER_FALLING |
714 				       IRQF_TRIGGER_RISING,
715 					DRIVER_NAME, sport);
716 			if (retval)
717 				goto error_out3;
718 		}
719 	} else {
720 		retval = request_irq(sport->port.irq, imx_int, 0,
721 				DRIVER_NAME, sport);
722 		if (retval) {
723 			free_irq(sport->port.irq, sport);
724 			goto error_out1;
725 		}
726 	}
727 
728 	/*
729 	 * Finally, clear and enable interrupts
730 	 */
731 	writel(USR1_RTSD, sport->port.membase + USR1);
732 
733 	temp = readl(sport->port.membase + UCR1);
734 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
735 
736 	if (USE_IRDA(sport)) {
737 		temp |= UCR1_IREN;
738 		temp &= ~(UCR1_RTSDEN);
739 	}
740 
741 	writel(temp, sport->port.membase + UCR1);
742 
743 	temp = readl(sport->port.membase + UCR2);
744 	temp |= (UCR2_RXEN | UCR2_TXEN);
745 	writel(temp, sport->port.membase + UCR2);
746 
747 	if (USE_IRDA(sport)) {
748 		/* clear RX-FIFO */
749 		int i = 64;
750 		while ((--i > 0) &&
751 			(readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
752 			barrier();
753 		}
754 	}
755 
756 	if (is_imx21_uart(sport)) {
757 		temp = readl(sport->port.membase + UCR3);
758 		temp |= IMX21_UCR3_RXDMUXSEL;
759 		writel(temp, sport->port.membase + UCR3);
760 	}
761 
762 	if (USE_IRDA(sport)) {
763 		temp = readl(sport->port.membase + UCR4);
764 		if (sport->irda_inv_rx)
765 			temp |= UCR4_INVR;
766 		else
767 			temp &= ~(UCR4_INVR);
768 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
769 
770 		temp = readl(sport->port.membase + UCR3);
771 		if (sport->irda_inv_tx)
772 			temp |= UCR3_INVT;
773 		else
774 			temp &= ~(UCR3_INVT);
775 		writel(temp, sport->port.membase + UCR3);
776 	}
777 
778 	/*
779 	 * Enable modem status interrupts
780 	 */
781 	spin_lock_irqsave(&sport->port.lock,flags);
782 	imx_enable_ms(&sport->port);
783 	spin_unlock_irqrestore(&sport->port.lock,flags);
784 
785 	if (USE_IRDA(sport)) {
786 		struct imxuart_platform_data *pdata;
787 		pdata = sport->port.dev->platform_data;
788 		sport->irda_inv_rx = pdata->irda_inv_rx;
789 		sport->irda_inv_tx = pdata->irda_inv_tx;
790 		sport->trcv_delay = pdata->transceiver_delay;
791 		if (pdata->irda_enable)
792 			pdata->irda_enable(1);
793 	}
794 
795 	return 0;
796 
797 error_out3:
798 	if (sport->txirq)
799 		free_irq(sport->txirq, sport);
800 error_out2:
801 	if (sport->rxirq)
802 		free_irq(sport->rxirq, sport);
803 error_out1:
804 	return retval;
805 }
806 
807 static void imx_shutdown(struct uart_port *port)
808 {
809 	struct imx_port *sport = (struct imx_port *)port;
810 	unsigned long temp;
811 
812 	temp = readl(sport->port.membase + UCR2);
813 	temp &= ~(UCR2_TXEN);
814 	writel(temp, sport->port.membase + UCR2);
815 
816 	if (USE_IRDA(sport)) {
817 		struct imxuart_platform_data *pdata;
818 		pdata = sport->port.dev->platform_data;
819 		if (pdata->irda_enable)
820 			pdata->irda_enable(0);
821 	}
822 
823 	/*
824 	 * Stop our timer.
825 	 */
826 	del_timer_sync(&sport->timer);
827 
828 	/*
829 	 * Free the interrupts
830 	 */
831 	if (sport->txirq > 0) {
832 		if (!USE_IRDA(sport))
833 			free_irq(sport->rtsirq, sport);
834 		free_irq(sport->txirq, sport);
835 		free_irq(sport->rxirq, sport);
836 	} else
837 		free_irq(sport->port.irq, sport);
838 
839 	/*
840 	 * Disable all interrupts, port and break condition.
841 	 */
842 
843 	temp = readl(sport->port.membase + UCR1);
844 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
845 	if (USE_IRDA(sport))
846 		temp &= ~(UCR1_IREN);
847 
848 	writel(temp, sport->port.membase + UCR1);
849 }
850 
851 static void
852 imx_set_termios(struct uart_port *port, struct ktermios *termios,
853 		   struct ktermios *old)
854 {
855 	struct imx_port *sport = (struct imx_port *)port;
856 	unsigned long flags;
857 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
858 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
859 	unsigned int div, ufcr;
860 	unsigned long num, denom;
861 	uint64_t tdiv64;
862 
863 	/*
864 	 * If we don't support modem control lines, don't allow
865 	 * these to be set.
866 	 */
867 	if (0) {
868 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
869 		termios->c_cflag |= CLOCAL;
870 	}
871 
872 	/*
873 	 * We only support CS7 and CS8.
874 	 */
875 	while ((termios->c_cflag & CSIZE) != CS7 &&
876 	       (termios->c_cflag & CSIZE) != CS8) {
877 		termios->c_cflag &= ~CSIZE;
878 		termios->c_cflag |= old_csize;
879 		old_csize = CS8;
880 	}
881 
882 	if ((termios->c_cflag & CSIZE) == CS8)
883 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
884 	else
885 		ucr2 = UCR2_SRST | UCR2_IRTS;
886 
887 	if (termios->c_cflag & CRTSCTS) {
888 		if( sport->have_rtscts ) {
889 			ucr2 &= ~UCR2_IRTS;
890 			ucr2 |= UCR2_CTSC;
891 		} else {
892 			termios->c_cflag &= ~CRTSCTS;
893 		}
894 	}
895 
896 	if (termios->c_cflag & CSTOPB)
897 		ucr2 |= UCR2_STPB;
898 	if (termios->c_cflag & PARENB) {
899 		ucr2 |= UCR2_PREN;
900 		if (termios->c_cflag & PARODD)
901 			ucr2 |= UCR2_PROE;
902 	}
903 
904 	/*
905 	 * Ask the core to calculate the divisor for us.
906 	 */
907 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
908 	quot = uart_get_divisor(port, baud);
909 
910 	spin_lock_irqsave(&sport->port.lock, flags);
911 
912 	sport->port.read_status_mask = 0;
913 	if (termios->c_iflag & INPCK)
914 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
915 	if (termios->c_iflag & (BRKINT | PARMRK))
916 		sport->port.read_status_mask |= URXD_BRK;
917 
918 	/*
919 	 * Characters to ignore
920 	 */
921 	sport->port.ignore_status_mask = 0;
922 	if (termios->c_iflag & IGNPAR)
923 		sport->port.ignore_status_mask |= URXD_PRERR;
924 	if (termios->c_iflag & IGNBRK) {
925 		sport->port.ignore_status_mask |= URXD_BRK;
926 		/*
927 		 * If we're ignoring parity and break indicators,
928 		 * ignore overruns too (for real raw support).
929 		 */
930 		if (termios->c_iflag & IGNPAR)
931 			sport->port.ignore_status_mask |= URXD_OVRRUN;
932 	}
933 
934 	del_timer_sync(&sport->timer);
935 
936 	/*
937 	 * Update the per-port timeout.
938 	 */
939 	uart_update_timeout(port, termios->c_cflag, baud);
940 
941 	/*
942 	 * disable interrupts and drain transmitter
943 	 */
944 	old_ucr1 = readl(sport->port.membase + UCR1);
945 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
946 			sport->port.membase + UCR1);
947 
948 	while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
949 		barrier();
950 
951 	/* then, disable everything */
952 	old_txrxen = readl(sport->port.membase + UCR2);
953 	writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
954 			sport->port.membase + UCR2);
955 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
956 
957 	if (USE_IRDA(sport)) {
958 		/*
959 		 * use maximum available submodule frequency to
960 		 * avoid missing short pulses due to low sampling rate
961 		 */
962 		div = 1;
963 	} else {
964 		div = sport->port.uartclk / (baud * 16);
965 		if (div > 7)
966 			div = 7;
967 		if (!div)
968 			div = 1;
969 	}
970 
971 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
972 		1 << 16, 1 << 16, &num, &denom);
973 
974 	tdiv64 = sport->port.uartclk;
975 	tdiv64 *= num;
976 	do_div(tdiv64, denom * 16 * div);
977 	tty_termios_encode_baud_rate(termios,
978 				(speed_t)tdiv64, (speed_t)tdiv64);
979 
980 	num -= 1;
981 	denom -= 1;
982 
983 	ufcr = readl(sport->port.membase + UFCR);
984 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
985 	writel(ufcr, sport->port.membase + UFCR);
986 
987 	writel(num, sport->port.membase + UBIR);
988 	writel(denom, sport->port.membase + UBMR);
989 
990 	if (is_imx21_uart(sport))
991 		writel(sport->port.uartclk / div / 1000,
992 				sport->port.membase + IMX21_ONEMS);
993 
994 	writel(old_ucr1, sport->port.membase + UCR1);
995 
996 	/* set the parity, stop bits and data size */
997 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
998 
999 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1000 		imx_enable_ms(&sport->port);
1001 
1002 	spin_unlock_irqrestore(&sport->port.lock, flags);
1003 }
1004 
1005 static const char *imx_type(struct uart_port *port)
1006 {
1007 	struct imx_port *sport = (struct imx_port *)port;
1008 
1009 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1010 }
1011 
1012 /*
1013  * Release the memory region(s) being used by 'port'.
1014  */
1015 static void imx_release_port(struct uart_port *port)
1016 {
1017 	struct platform_device *pdev = to_platform_device(port->dev);
1018 	struct resource *mmres;
1019 
1020 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1021 	release_mem_region(mmres->start, resource_size(mmres));
1022 }
1023 
1024 /*
1025  * Request the memory region(s) being used by 'port'.
1026  */
1027 static int imx_request_port(struct uart_port *port)
1028 {
1029 	struct platform_device *pdev = to_platform_device(port->dev);
1030 	struct resource *mmres;
1031 	void *ret;
1032 
1033 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1034 	if (!mmres)
1035 		return -ENODEV;
1036 
1037 	ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
1038 
1039 	return  ret ? 0 : -EBUSY;
1040 }
1041 
1042 /*
1043  * Configure/autoconfigure the port.
1044  */
1045 static void imx_config_port(struct uart_port *port, int flags)
1046 {
1047 	struct imx_port *sport = (struct imx_port *)port;
1048 
1049 	if (flags & UART_CONFIG_TYPE &&
1050 	    imx_request_port(&sport->port) == 0)
1051 		sport->port.type = PORT_IMX;
1052 }
1053 
1054 /*
1055  * Verify the new serial_struct (for TIOCSSERIAL).
1056  * The only change we allow are to the flags and type, and
1057  * even then only between PORT_IMX and PORT_UNKNOWN
1058  */
1059 static int
1060 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1061 {
1062 	struct imx_port *sport = (struct imx_port *)port;
1063 	int ret = 0;
1064 
1065 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1066 		ret = -EINVAL;
1067 	if (sport->port.irq != ser->irq)
1068 		ret = -EINVAL;
1069 	if (ser->io_type != UPIO_MEM)
1070 		ret = -EINVAL;
1071 	if (sport->port.uartclk / 16 != ser->baud_base)
1072 		ret = -EINVAL;
1073 	if ((void *)sport->port.mapbase != ser->iomem_base)
1074 		ret = -EINVAL;
1075 	if (sport->port.iobase != ser->port)
1076 		ret = -EINVAL;
1077 	if (ser->hub6 != 0)
1078 		ret = -EINVAL;
1079 	return ret;
1080 }
1081 
1082 static struct uart_ops imx_pops = {
1083 	.tx_empty	= imx_tx_empty,
1084 	.set_mctrl	= imx_set_mctrl,
1085 	.get_mctrl	= imx_get_mctrl,
1086 	.stop_tx	= imx_stop_tx,
1087 	.start_tx	= imx_start_tx,
1088 	.stop_rx	= imx_stop_rx,
1089 	.enable_ms	= imx_enable_ms,
1090 	.break_ctl	= imx_break_ctl,
1091 	.startup	= imx_startup,
1092 	.shutdown	= imx_shutdown,
1093 	.set_termios	= imx_set_termios,
1094 	.type		= imx_type,
1095 	.release_port	= imx_release_port,
1096 	.request_port	= imx_request_port,
1097 	.config_port	= imx_config_port,
1098 	.verify_port	= imx_verify_port,
1099 };
1100 
1101 static struct imx_port *imx_ports[UART_NR];
1102 
1103 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1104 static void imx_console_putchar(struct uart_port *port, int ch)
1105 {
1106 	struct imx_port *sport = (struct imx_port *)port;
1107 
1108 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1109 		barrier();
1110 
1111 	writel(ch, sport->port.membase + URTX0);
1112 }
1113 
1114 /*
1115  * Interrupts are disabled on entering
1116  */
1117 static void
1118 imx_console_write(struct console *co, const char *s, unsigned int count)
1119 {
1120 	struct imx_port *sport = imx_ports[co->index];
1121 	unsigned int old_ucr1, old_ucr2, ucr1;
1122 
1123 	/*
1124 	 *	First, save UCR1/2 and then disable interrupts
1125 	 */
1126 	ucr1 = old_ucr1 = readl(sport->port.membase + UCR1);
1127 	old_ucr2 = readl(sport->port.membase + UCR2);
1128 
1129 	if (is_imx1_uart(sport))
1130 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1131 	ucr1 |= UCR1_UARTEN;
1132 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1133 
1134 	writel(ucr1, sport->port.membase + UCR1);
1135 
1136 	writel(old_ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1137 
1138 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1139 
1140 	/*
1141 	 *	Finally, wait for transmitter to become empty
1142 	 *	and restore UCR1/2
1143 	 */
1144 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1145 
1146 	writel(old_ucr1, sport->port.membase + UCR1);
1147 	writel(old_ucr2, sport->port.membase + UCR2);
1148 }
1149 
1150 /*
1151  * If the port was already initialised (eg, by a boot loader),
1152  * try to determine the current setup.
1153  */
1154 static void __init
1155 imx_console_get_options(struct imx_port *sport, int *baud,
1156 			   int *parity, int *bits)
1157 {
1158 
1159 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1160 		/* ok, the port was enabled */
1161 		unsigned int ucr2, ubir,ubmr, uartclk;
1162 		unsigned int baud_raw;
1163 		unsigned int ucfr_rfdiv;
1164 
1165 		ucr2 = readl(sport->port.membase + UCR2);
1166 
1167 		*parity = 'n';
1168 		if (ucr2 & UCR2_PREN) {
1169 			if (ucr2 & UCR2_PROE)
1170 				*parity = 'o';
1171 			else
1172 				*parity = 'e';
1173 		}
1174 
1175 		if (ucr2 & UCR2_WS)
1176 			*bits = 8;
1177 		else
1178 			*bits = 7;
1179 
1180 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1181 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1182 
1183 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1184 		if (ucfr_rfdiv == 6)
1185 			ucfr_rfdiv = 7;
1186 		else
1187 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1188 
1189 		uartclk = clk_get_rate(sport->clk);
1190 		uartclk /= ucfr_rfdiv;
1191 
1192 		{	/*
1193 			 * The next code provides exact computation of
1194 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1195 			 * without need of float support or long long division,
1196 			 * which would be required to prevent 32bit arithmetic overflow
1197 			 */
1198 			unsigned int mul = ubir + 1;
1199 			unsigned int div = 16 * (ubmr + 1);
1200 			unsigned int rem = uartclk % div;
1201 
1202 			baud_raw = (uartclk / div) * mul;
1203 			baud_raw += (rem * mul + div / 2) / div;
1204 			*baud = (baud_raw + 50) / 100 * 100;
1205 		}
1206 
1207 		if(*baud != baud_raw)
1208 			printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
1209 				baud_raw, *baud);
1210 	}
1211 }
1212 
1213 static int __init
1214 imx_console_setup(struct console *co, char *options)
1215 {
1216 	struct imx_port *sport;
1217 	int baud = 9600;
1218 	int bits = 8;
1219 	int parity = 'n';
1220 	int flow = 'n';
1221 
1222 	/*
1223 	 * Check whether an invalid uart number has been specified, and
1224 	 * if so, search for the first available port that does have
1225 	 * console support.
1226 	 */
1227 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1228 		co->index = 0;
1229 	sport = imx_ports[co->index];
1230 	if(sport == NULL)
1231 		return -ENODEV;
1232 
1233 	if (options)
1234 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1235 	else
1236 		imx_console_get_options(sport, &baud, &parity, &bits);
1237 
1238 	imx_setup_ufcr(sport, 0);
1239 
1240 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
1241 }
1242 
1243 static struct uart_driver imx_reg;
1244 static struct console imx_console = {
1245 	.name		= DEV_NAME,
1246 	.write		= imx_console_write,
1247 	.device		= uart_console_device,
1248 	.setup		= imx_console_setup,
1249 	.flags		= CON_PRINTBUFFER,
1250 	.index		= -1,
1251 	.data		= &imx_reg,
1252 };
1253 
1254 #define IMX_CONSOLE	&imx_console
1255 #else
1256 #define IMX_CONSOLE	NULL
1257 #endif
1258 
1259 static struct uart_driver imx_reg = {
1260 	.owner          = THIS_MODULE,
1261 	.driver_name    = DRIVER_NAME,
1262 	.dev_name       = DEV_NAME,
1263 	.major          = SERIAL_IMX_MAJOR,
1264 	.minor          = MINOR_START,
1265 	.nr             = ARRAY_SIZE(imx_ports),
1266 	.cons           = IMX_CONSOLE,
1267 };
1268 
1269 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1270 {
1271 	struct imx_port *sport = platform_get_drvdata(dev);
1272 
1273 	if (sport)
1274 		uart_suspend_port(&imx_reg, &sport->port);
1275 
1276 	return 0;
1277 }
1278 
1279 static int serial_imx_resume(struct platform_device *dev)
1280 {
1281 	struct imx_port *sport = platform_get_drvdata(dev);
1282 
1283 	if (sport)
1284 		uart_resume_port(&imx_reg, &sport->port);
1285 
1286 	return 0;
1287 }
1288 
1289 #ifdef CONFIG_OF
1290 static int serial_imx_probe_dt(struct imx_port *sport,
1291 		struct platform_device *pdev)
1292 {
1293 	struct device_node *np = pdev->dev.of_node;
1294 	const struct of_device_id *of_id =
1295 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1296 	int ret;
1297 
1298 	if (!np)
1299 		return -ENODEV;
1300 
1301 	ret = of_alias_get_id(np, "serial");
1302 	if (ret < 0) {
1303 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1304 		return -ENODEV;
1305 	}
1306 	sport->port.line = ret;
1307 
1308 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1309 		sport->have_rtscts = 1;
1310 
1311 	if (of_get_property(np, "fsl,irda-mode", NULL))
1312 		sport->use_irda = 1;
1313 
1314 	sport->devdata = of_id->data;
1315 
1316 	return 0;
1317 }
1318 #else
1319 static inline int serial_imx_probe_dt(struct imx_port *sport,
1320 		struct platform_device *pdev)
1321 {
1322 	return -ENODEV;
1323 }
1324 #endif
1325 
1326 static void serial_imx_probe_pdata(struct imx_port *sport,
1327 		struct platform_device *pdev)
1328 {
1329 	struct imxuart_platform_data *pdata = pdev->dev.platform_data;
1330 
1331 	sport->port.line = pdev->id;
1332 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1333 
1334 	if (!pdata)
1335 		return;
1336 
1337 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1338 		sport->have_rtscts = 1;
1339 
1340 	if (pdata->flags & IMXUART_IRDA)
1341 		sport->use_irda = 1;
1342 }
1343 
1344 static int serial_imx_probe(struct platform_device *pdev)
1345 {
1346 	struct imx_port *sport;
1347 	struct imxuart_platform_data *pdata;
1348 	void __iomem *base;
1349 	int ret = 0;
1350 	struct resource *res;
1351 
1352 	sport = kzalloc(sizeof(*sport), GFP_KERNEL);
1353 	if (!sport)
1354 		return -ENOMEM;
1355 
1356 	ret = serial_imx_probe_dt(sport, pdev);
1357 	if (ret == -ENODEV)
1358 		serial_imx_probe_pdata(sport, pdev);
1359 
1360 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1361 	if (!res) {
1362 		ret = -ENODEV;
1363 		goto free;
1364 	}
1365 
1366 	base = ioremap(res->start, PAGE_SIZE);
1367 	if (!base) {
1368 		ret = -ENOMEM;
1369 		goto free;
1370 	}
1371 
1372 	sport->port.dev = &pdev->dev;
1373 	sport->port.mapbase = res->start;
1374 	sport->port.membase = base;
1375 	sport->port.type = PORT_IMX,
1376 	sport->port.iotype = UPIO_MEM;
1377 	sport->port.irq = platform_get_irq(pdev, 0);
1378 	sport->rxirq = platform_get_irq(pdev, 0);
1379 	sport->txirq = platform_get_irq(pdev, 1);
1380 	sport->rtsirq = platform_get_irq(pdev, 2);
1381 	sport->port.fifosize = 32;
1382 	sport->port.ops = &imx_pops;
1383 	sport->port.flags = UPF_BOOT_AUTOCONF;
1384 	init_timer(&sport->timer);
1385 	sport->timer.function = imx_timeout;
1386 	sport->timer.data     = (unsigned long)sport;
1387 
1388 	sport->clk = clk_get(&pdev->dev, "uart");
1389 	if (IS_ERR(sport->clk)) {
1390 		ret = PTR_ERR(sport->clk);
1391 		goto unmap;
1392 	}
1393 	clk_enable(sport->clk);
1394 
1395 	sport->port.uartclk = clk_get_rate(sport->clk);
1396 
1397 	imx_ports[sport->port.line] = sport;
1398 
1399 	pdata = pdev->dev.platform_data;
1400 	if (pdata && pdata->init) {
1401 		ret = pdata->init(pdev);
1402 		if (ret)
1403 			goto clkput;
1404 	}
1405 
1406 	ret = uart_add_one_port(&imx_reg, &sport->port);
1407 	if (ret)
1408 		goto deinit;
1409 	platform_set_drvdata(pdev, &sport->port);
1410 
1411 	return 0;
1412 deinit:
1413 	if (pdata && pdata->exit)
1414 		pdata->exit(pdev);
1415 clkput:
1416 	clk_put(sport->clk);
1417 	clk_disable(sport->clk);
1418 unmap:
1419 	iounmap(sport->port.membase);
1420 free:
1421 	kfree(sport);
1422 
1423 	return ret;
1424 }
1425 
1426 static int serial_imx_remove(struct platform_device *pdev)
1427 {
1428 	struct imxuart_platform_data *pdata;
1429 	struct imx_port *sport = platform_get_drvdata(pdev);
1430 
1431 	pdata = pdev->dev.platform_data;
1432 
1433 	platform_set_drvdata(pdev, NULL);
1434 
1435 	if (sport) {
1436 		uart_remove_one_port(&imx_reg, &sport->port);
1437 		clk_put(sport->clk);
1438 	}
1439 
1440 	clk_disable(sport->clk);
1441 
1442 	if (pdata && pdata->exit)
1443 		pdata->exit(pdev);
1444 
1445 	iounmap(sport->port.membase);
1446 	kfree(sport);
1447 
1448 	return 0;
1449 }
1450 
1451 static struct platform_driver serial_imx_driver = {
1452 	.probe		= serial_imx_probe,
1453 	.remove		= serial_imx_remove,
1454 
1455 	.suspend	= serial_imx_suspend,
1456 	.resume		= serial_imx_resume,
1457 	.id_table	= imx_uart_devtype,
1458 	.driver		= {
1459 		.name	= "imx-uart",
1460 		.owner	= THIS_MODULE,
1461 		.of_match_table = imx_uart_dt_ids,
1462 	},
1463 };
1464 
1465 static int __init imx_serial_init(void)
1466 {
1467 	int ret;
1468 
1469 	printk(KERN_INFO "Serial: IMX driver\n");
1470 
1471 	ret = uart_register_driver(&imx_reg);
1472 	if (ret)
1473 		return ret;
1474 
1475 	ret = platform_driver_register(&serial_imx_driver);
1476 	if (ret != 0)
1477 		uart_unregister_driver(&imx_reg);
1478 
1479 	return 0;
1480 }
1481 
1482 static void __exit imx_serial_exit(void)
1483 {
1484 	platform_driver_unregister(&serial_imx_driver);
1485 	uart_unregister_driver(&imx_reg);
1486 }
1487 
1488 module_init(imx_serial_init);
1489 module_exit(imx_serial_exit);
1490 
1491 MODULE_AUTHOR("Sascha Hauer");
1492 MODULE_DESCRIPTION("IMX generic serial port driver");
1493 MODULE_LICENSE("GPL");
1494 MODULE_ALIAS("platform:imx-uart");
1495