xref: /openbmc/linux/drivers/tty/serial/imx.c (revision 73eb94a0)
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_ATEN       (1<<3)  /* Aging Timer Enable */
106 #define  UCR2_TXEN       (1<<2)	 /* Transmitter enabled */
107 #define  UCR2_RXEN       (1<<1)	 /* Receiver enabled */
108 #define  UCR2_SRST 	 (1<<0)	 /* SW reset */
109 #define  UCR3_DTREN 	 (1<<13) /* DTR interrupt enable */
110 #define  UCR3_PARERREN   (1<<12) /* Parity enable */
111 #define  UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
112 #define  UCR3_DSR        (1<<10) /* Data set ready */
113 #define  UCR3_DCD        (1<<9)  /* Data carrier detect */
114 #define  UCR3_RI         (1<<8)  /* Ring indicator */
115 #define  UCR3_TIMEOUTEN  (1<<7)  /* Timeout interrupt enable */
116 #define  UCR3_RXDSEN	 (1<<6)  /* Receive status interrupt enable */
117 #define  UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
118 #define  UCR3_AWAKEN	 (1<<4)  /* Async wake interrupt enable */
119 #define  IMX21_UCR3_RXDMUXSEL	 (1<<2)  /* RXD Muxed Input Select */
120 #define  UCR3_INVT  	 (1<<1)  /* Inverted Infrared transmission */
121 #define  UCR3_BPEN  	 (1<<0)  /* Preset registers enable */
122 #define  UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
123 #define  UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
124 #define  UCR4_INVR  	 (1<<9)  /* Inverted infrared reception */
125 #define  UCR4_ENIRI 	 (1<<8)  /* Serial infrared interrupt enable */
126 #define  UCR4_WKEN  	 (1<<7)  /* Wake interrupt enable */
127 #define  UCR4_REF16 	 (1<<6)  /* Ref freq 16 MHz */
128 #define  UCR4_IRSC  	 (1<<5)  /* IR special case */
129 #define  UCR4_TCEN  	 (1<<3)  /* Transmit complete interrupt enable */
130 #define  UCR4_BKEN  	 (1<<2)  /* Break condition interrupt enable */
131 #define  UCR4_OREN  	 (1<<1)  /* Receiver overrun interrupt enable */
132 #define  UCR4_DREN  	 (1<<0)  /* Recv data ready interrupt enable */
133 #define  UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
134 #define  UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
135 #define  UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
136 #define  UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
137 #define  USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
138 #define  USR1_RTSS  	 (1<<14) /* RTS pin status */
139 #define  USR1_TRDY  	 (1<<13) /* Transmitter ready interrupt/dma flag */
140 #define  USR1_RTSD  	 (1<<12) /* RTS delta */
141 #define  USR1_ESCF  	 (1<<11) /* Escape seq interrupt flag */
142 #define  USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
143 #define  USR1_RRDY       (1<<9)	 /* Receiver ready interrupt/dma flag */
144 #define  USR1_TIMEOUT    (1<<7)	 /* Receive timeout interrupt status */
145 #define  USR1_RXDS  	 (1<<6)	 /* Receiver idle interrupt flag */
146 #define  USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
147 #define  USR1_AWAKE 	 (1<<4)	 /* Aysnc wake interrupt flag */
148 #define  USR2_ADET  	 (1<<15) /* Auto baud rate detect complete */
149 #define  USR2_TXFE  	 (1<<14) /* Transmit buffer FIFO empty */
150 #define  USR2_DTRF  	 (1<<13) /* DTR edge interrupt flag */
151 #define  USR2_IDLE  	 (1<<12) /* Idle condition */
152 #define  USR2_IRINT 	 (1<<8)	 /* Serial infrared interrupt flag */
153 #define  USR2_WAKE  	 (1<<7)	 /* Wake */
154 #define  USR2_RTSF  	 (1<<4)	 /* RTS edge interrupt flag */
155 #define  USR2_TXDC  	 (1<<3)	 /* Transmitter complete */
156 #define  USR2_BRCD  	 (1<<2)	 /* Break condition */
157 #define  USR2_ORE        (1<<1)	 /* Overrun error */
158 #define  USR2_RDR        (1<<0)	 /* Recv data ready */
159 #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
160 #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
161 #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
162 #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
163 #define  UTS_TXFULL 	 (1<<4)	 /* TxFIFO full */
164 #define  UTS_RXFULL 	 (1<<3)	 /* RxFIFO full */
165 #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
166 
167 /* We've been assigned a range on the "Low-density serial ports" major */
168 #define SERIAL_IMX_MAJOR        207
169 #define MINOR_START	        16
170 #define DEV_NAME		"ttymxc"
171 #define MAX_INTERNAL_IRQ	MXC_INTERNAL_IRQS
172 
173 /*
174  * This determines how often we check the modem status signals
175  * for any change.  They generally aren't connected to an IRQ
176  * so we have to poll them.  We also check immediately before
177  * filling the TX fifo incase CTS has been dropped.
178  */
179 #define MCTRL_TIMEOUT	(250*HZ/1000)
180 
181 #define DRIVER_NAME "IMX-uart"
182 
183 #define UART_NR 8
184 
185 /* i.mx21 type uart runs on all i.mx except i.mx1 */
186 enum imx_uart_type {
187 	IMX1_UART,
188 	IMX21_UART,
189 };
190 
191 /* device type dependent stuff */
192 struct imx_uart_data {
193 	unsigned uts_reg;
194 	enum imx_uart_type devtype;
195 };
196 
197 struct imx_port {
198 	struct uart_port	port;
199 	struct timer_list	timer;
200 	unsigned int		old_status;
201 	int			txirq,rxirq,rtsirq;
202 	unsigned int		have_rtscts:1;
203 	unsigned int		use_irda:1;
204 	unsigned int		irda_inv_rx:1;
205 	unsigned int		irda_inv_tx:1;
206 	unsigned short		trcv_delay; /* transceiver delay */
207 	struct clk		*clk;
208 	struct imx_uart_data	*devdata;
209 };
210 
211 struct imx_port_ucrs {
212 	unsigned int	ucr1;
213 	unsigned int	ucr2;
214 	unsigned int	ucr3;
215 };
216 
217 #ifdef CONFIG_IRDA
218 #define USE_IRDA(sport)	((sport)->use_irda)
219 #else
220 #define USE_IRDA(sport)	(0)
221 #endif
222 
223 static struct imx_uart_data imx_uart_devdata[] = {
224 	[IMX1_UART] = {
225 		.uts_reg = IMX1_UTS,
226 		.devtype = IMX1_UART,
227 	},
228 	[IMX21_UART] = {
229 		.uts_reg = IMX21_UTS,
230 		.devtype = IMX21_UART,
231 	},
232 };
233 
234 static struct platform_device_id imx_uart_devtype[] = {
235 	{
236 		.name = "imx1-uart",
237 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
238 	}, {
239 		.name = "imx21-uart",
240 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
241 	}, {
242 		/* sentinel */
243 	}
244 };
245 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
246 
247 static struct of_device_id imx_uart_dt_ids[] = {
248 	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
249 	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
250 	{ /* sentinel */ }
251 };
252 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
253 
254 static inline unsigned uts_reg(struct imx_port *sport)
255 {
256 	return sport->devdata->uts_reg;
257 }
258 
259 static inline int is_imx1_uart(struct imx_port *sport)
260 {
261 	return sport->devdata->devtype == IMX1_UART;
262 }
263 
264 static inline int is_imx21_uart(struct imx_port *sport)
265 {
266 	return sport->devdata->devtype == IMX21_UART;
267 }
268 
269 /*
270  * Save and restore functions for UCR1, UCR2 and UCR3 registers
271  */
272 static void imx_port_ucrs_save(struct uart_port *port,
273 			       struct imx_port_ucrs *ucr)
274 {
275 	/* save control registers */
276 	ucr->ucr1 = readl(port->membase + UCR1);
277 	ucr->ucr2 = readl(port->membase + UCR2);
278 	ucr->ucr3 = readl(port->membase + UCR3);
279 }
280 
281 static void imx_port_ucrs_restore(struct uart_port *port,
282 				  struct imx_port_ucrs *ucr)
283 {
284 	/* restore control registers */
285 	writel(ucr->ucr1, port->membase + UCR1);
286 	writel(ucr->ucr2, port->membase + UCR2);
287 	writel(ucr->ucr3, port->membase + UCR3);
288 }
289 
290 /*
291  * Handle any change of modem status signal since we were last called.
292  */
293 static void imx_mctrl_check(struct imx_port *sport)
294 {
295 	unsigned int status, changed;
296 
297 	status = sport->port.ops->get_mctrl(&sport->port);
298 	changed = status ^ sport->old_status;
299 
300 	if (changed == 0)
301 		return;
302 
303 	sport->old_status = status;
304 
305 	if (changed & TIOCM_RI)
306 		sport->port.icount.rng++;
307 	if (changed & TIOCM_DSR)
308 		sport->port.icount.dsr++;
309 	if (changed & TIOCM_CAR)
310 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
311 	if (changed & TIOCM_CTS)
312 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
313 
314 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
315 }
316 
317 /*
318  * This is our per-port timeout handler, for checking the
319  * modem status signals.
320  */
321 static void imx_timeout(unsigned long data)
322 {
323 	struct imx_port *sport = (struct imx_port *)data;
324 	unsigned long flags;
325 
326 	if (sport->port.state) {
327 		spin_lock_irqsave(&sport->port.lock, flags);
328 		imx_mctrl_check(sport);
329 		spin_unlock_irqrestore(&sport->port.lock, flags);
330 
331 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
332 	}
333 }
334 
335 /*
336  * interrupts disabled on entry
337  */
338 static void imx_stop_tx(struct uart_port *port)
339 {
340 	struct imx_port *sport = (struct imx_port *)port;
341 	unsigned long temp;
342 
343 	if (USE_IRDA(sport)) {
344 		/* half duplex - wait for end of transmission */
345 		int n = 256;
346 		while ((--n > 0) &&
347 		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
348 			udelay(5);
349 			barrier();
350 		}
351 		/*
352 		 * irda transceiver - wait a bit more to avoid
353 		 * cutoff, hardware dependent
354 		 */
355 		udelay(sport->trcv_delay);
356 
357 		/*
358 		 * half duplex - reactivate receive mode,
359 		 * flush receive pipe echo crap
360 		 */
361 		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
362 			temp = readl(sport->port.membase + UCR1);
363 			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
364 			writel(temp, sport->port.membase + UCR1);
365 
366 			temp = readl(sport->port.membase + UCR4);
367 			temp &= ~(UCR4_TCEN);
368 			writel(temp, sport->port.membase + UCR4);
369 
370 			while (readl(sport->port.membase + URXD0) &
371 			       URXD_CHARRDY)
372 				barrier();
373 
374 			temp = readl(sport->port.membase + UCR1);
375 			temp |= UCR1_RRDYEN;
376 			writel(temp, sport->port.membase + UCR1);
377 
378 			temp = readl(sport->port.membase + UCR4);
379 			temp |= UCR4_DREN;
380 			writel(temp, sport->port.membase + UCR4);
381 		}
382 		return;
383 	}
384 
385 	temp = readl(sport->port.membase + UCR1);
386 	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
387 }
388 
389 /*
390  * interrupts disabled on entry
391  */
392 static void imx_stop_rx(struct uart_port *port)
393 {
394 	struct imx_port *sport = (struct imx_port *)port;
395 	unsigned long temp;
396 
397 	temp = readl(sport->port.membase + UCR2);
398 	writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
399 }
400 
401 /*
402  * Set the modem control timer to fire immediately.
403  */
404 static void imx_enable_ms(struct uart_port *port)
405 {
406 	struct imx_port *sport = (struct imx_port *)port;
407 
408 	mod_timer(&sport->timer, jiffies);
409 }
410 
411 static inline void imx_transmit_buffer(struct imx_port *sport)
412 {
413 	struct circ_buf *xmit = &sport->port.state->xmit;
414 
415 	while (!uart_circ_empty(xmit) &&
416 			!(readl(sport->port.membase + uts_reg(sport))
417 				& UTS_TXFULL)) {
418 		/* send xmit->buf[xmit->tail]
419 		 * out the port here */
420 		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
421 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
422 		sport->port.icount.tx++;
423 	}
424 
425 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
426 		uart_write_wakeup(&sport->port);
427 
428 	if (uart_circ_empty(xmit))
429 		imx_stop_tx(&sport->port);
430 }
431 
432 /*
433  * interrupts disabled on entry
434  */
435 static void imx_start_tx(struct uart_port *port)
436 {
437 	struct imx_port *sport = (struct imx_port *)port;
438 	unsigned long temp;
439 
440 	if (USE_IRDA(sport)) {
441 		/* half duplex in IrDA mode; have to disable receive mode */
442 		temp = readl(sport->port.membase + UCR4);
443 		temp &= ~(UCR4_DREN);
444 		writel(temp, sport->port.membase + UCR4);
445 
446 		temp = readl(sport->port.membase + UCR1);
447 		temp &= ~(UCR1_RRDYEN);
448 		writel(temp, sport->port.membase + UCR1);
449 	}
450 
451 	temp = readl(sport->port.membase + UCR1);
452 	writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
453 
454 	if (USE_IRDA(sport)) {
455 		temp = readl(sport->port.membase + UCR1);
456 		temp |= UCR1_TRDYEN;
457 		writel(temp, sport->port.membase + UCR1);
458 
459 		temp = readl(sport->port.membase + UCR4);
460 		temp |= UCR4_TCEN;
461 		writel(temp, sport->port.membase + UCR4);
462 	}
463 
464 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
465 		imx_transmit_buffer(sport);
466 }
467 
468 static irqreturn_t imx_rtsint(int irq, void *dev_id)
469 {
470 	struct imx_port *sport = dev_id;
471 	unsigned int val;
472 	unsigned long flags;
473 
474 	spin_lock_irqsave(&sport->port.lock, flags);
475 
476 	writel(USR1_RTSD, sport->port.membase + USR1);
477 	val = readl(sport->port.membase + USR1) & USR1_RTSS;
478 	uart_handle_cts_change(&sport->port, !!val);
479 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
480 
481 	spin_unlock_irqrestore(&sport->port.lock, flags);
482 	return IRQ_HANDLED;
483 }
484 
485 static irqreturn_t imx_txint(int irq, void *dev_id)
486 {
487 	struct imx_port *sport = dev_id;
488 	struct circ_buf *xmit = &sport->port.state->xmit;
489 	unsigned long flags;
490 
491 	spin_lock_irqsave(&sport->port.lock,flags);
492 	if (sport->port.x_char)
493 	{
494 		/* Send next char */
495 		writel(sport->port.x_char, sport->port.membase + URTX0);
496 		goto out;
497 	}
498 
499 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
500 		imx_stop_tx(&sport->port);
501 		goto out;
502 	}
503 
504 	imx_transmit_buffer(sport);
505 
506 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
507 		uart_write_wakeup(&sport->port);
508 
509 out:
510 	spin_unlock_irqrestore(&sport->port.lock,flags);
511 	return IRQ_HANDLED;
512 }
513 
514 static irqreturn_t imx_rxint(int irq, void *dev_id)
515 {
516 	struct imx_port *sport = dev_id;
517 	unsigned int rx,flg,ignored = 0;
518 	struct tty_struct *tty = sport->port.state->port.tty;
519 	unsigned long flags, temp;
520 
521 	spin_lock_irqsave(&sport->port.lock,flags);
522 
523 	while (readl(sport->port.membase + USR2) & USR2_RDR) {
524 		flg = TTY_NORMAL;
525 		sport->port.icount.rx++;
526 
527 		rx = readl(sport->port.membase + URXD0);
528 
529 		temp = readl(sport->port.membase + USR2);
530 		if (temp & USR2_BRCD) {
531 			writel(USR2_BRCD, sport->port.membase + USR2);
532 			if (uart_handle_break(&sport->port))
533 				continue;
534 		}
535 
536 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
537 			continue;
538 
539 		if (unlikely(rx & URXD_ERR)) {
540 			if (rx & URXD_BRK)
541 				sport->port.icount.brk++;
542 			else if (rx & URXD_PRERR)
543 				sport->port.icount.parity++;
544 			else if (rx & URXD_FRMERR)
545 				sport->port.icount.frame++;
546 			if (rx & URXD_OVRRUN)
547 				sport->port.icount.overrun++;
548 
549 			if (rx & sport->port.ignore_status_mask) {
550 				if (++ignored > 100)
551 					goto out;
552 				continue;
553 			}
554 
555 			rx &= sport->port.read_status_mask;
556 
557 			if (rx & URXD_BRK)
558 				flg = TTY_BREAK;
559 			else if (rx & URXD_PRERR)
560 				flg = TTY_PARITY;
561 			else if (rx & URXD_FRMERR)
562 				flg = TTY_FRAME;
563 			if (rx & URXD_OVRRUN)
564 				flg = TTY_OVERRUN;
565 
566 #ifdef SUPPORT_SYSRQ
567 			sport->port.sysrq = 0;
568 #endif
569 		}
570 
571 		tty_insert_flip_char(tty, rx, flg);
572 	}
573 
574 out:
575 	spin_unlock_irqrestore(&sport->port.lock,flags);
576 	tty_flip_buffer_push(tty);
577 	return IRQ_HANDLED;
578 }
579 
580 static irqreturn_t imx_int(int irq, void *dev_id)
581 {
582 	struct imx_port *sport = dev_id;
583 	unsigned int sts;
584 
585 	sts = readl(sport->port.membase + USR1);
586 
587 	if (sts & USR1_RRDY)
588 		imx_rxint(irq, dev_id);
589 
590 	if (sts & USR1_TRDY &&
591 			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
592 		imx_txint(irq, dev_id);
593 
594 	if (sts & USR1_RTSD)
595 		imx_rtsint(irq, dev_id);
596 
597 	if (sts & USR1_AWAKE)
598 		writel(USR1_AWAKE, sport->port.membase + USR1);
599 
600 	return IRQ_HANDLED;
601 }
602 
603 /*
604  * Return TIOCSER_TEMT when transmitter is not busy.
605  */
606 static unsigned int imx_tx_empty(struct uart_port *port)
607 {
608 	struct imx_port *sport = (struct imx_port *)port;
609 
610 	return (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
611 }
612 
613 /*
614  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
615  */
616 static unsigned int imx_get_mctrl(struct uart_port *port)
617 {
618 	struct imx_port *sport = (struct imx_port *)port;
619 	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
620 
621 	if (readl(sport->port.membase + USR1) & USR1_RTSS)
622 		tmp |= TIOCM_CTS;
623 
624 	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
625 		tmp |= TIOCM_RTS;
626 
627 	return tmp;
628 }
629 
630 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
631 {
632 	struct imx_port *sport = (struct imx_port *)port;
633 	unsigned long temp;
634 
635 	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
636 
637 	if (mctrl & TIOCM_RTS)
638 		temp |= UCR2_CTS;
639 
640 	writel(temp, sport->port.membase + UCR2);
641 }
642 
643 /*
644  * Interrupts always disabled.
645  */
646 static void imx_break_ctl(struct uart_port *port, int break_state)
647 {
648 	struct imx_port *sport = (struct imx_port *)port;
649 	unsigned long flags, temp;
650 
651 	spin_lock_irqsave(&sport->port.lock, flags);
652 
653 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
654 
655 	if ( break_state != 0 )
656 		temp |= UCR1_SNDBRK;
657 
658 	writel(temp, sport->port.membase + UCR1);
659 
660 	spin_unlock_irqrestore(&sport->port.lock, flags);
661 }
662 
663 #define TXTL 2 /* reset default */
664 #define RXTL 1 /* reset default */
665 
666 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
667 {
668 	unsigned int val;
669 	unsigned int ufcr_rfdiv;
670 
671 	/* set receiver / transmitter trigger level.
672 	 * RFDIV is set such way to satisfy requested uartclk value
673 	 */
674 	val = TXTL << 10 | RXTL;
675 	ufcr_rfdiv = (clk_get_rate(sport->clk) + sport->port.uartclk / 2)
676 			/ sport->port.uartclk;
677 
678 	if(!ufcr_rfdiv)
679 		ufcr_rfdiv = 1;
680 
681 	val |= UFCR_RFDIV_REG(ufcr_rfdiv);
682 
683 	writel(val, sport->port.membase + UFCR);
684 
685 	return 0;
686 }
687 
688 /* half the RX buffer size */
689 #define CTSTL 16
690 
691 static int imx_startup(struct uart_port *port)
692 {
693 	struct imx_port *sport = (struct imx_port *)port;
694 	int retval;
695 	unsigned long flags, temp;
696 
697 	imx_setup_ufcr(sport, 0);
698 
699 	/* disable the DREN bit (Data Ready interrupt enable) before
700 	 * requesting IRQs
701 	 */
702 	temp = readl(sport->port.membase + UCR4);
703 
704 	if (USE_IRDA(sport))
705 		temp |= UCR4_IRSC;
706 
707 	/* set the trigger level for CTS */
708 	temp &= ~(UCR4_CTSTL_MASK<<  UCR4_CTSTL_SHF);
709 	temp |= CTSTL<<  UCR4_CTSTL_SHF;
710 
711 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
712 
713 	if (USE_IRDA(sport)) {
714 		/* reset fifo's and state machines */
715 		int i = 100;
716 		temp = readl(sport->port.membase + UCR2);
717 		temp &= ~UCR2_SRST;
718 		writel(temp, sport->port.membase + UCR2);
719 		while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
720 		    (--i > 0)) {
721 			udelay(1);
722 		}
723 	}
724 
725 	/*
726 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
727 	 * chips only have one interrupt.
728 	 */
729 	if (sport->txirq > 0) {
730 		retval = request_irq(sport->rxirq, imx_rxint, 0,
731 				DRIVER_NAME, sport);
732 		if (retval)
733 			goto error_out1;
734 
735 		retval = request_irq(sport->txirq, imx_txint, 0,
736 				DRIVER_NAME, sport);
737 		if (retval)
738 			goto error_out2;
739 
740 		/* do not use RTS IRQ on IrDA */
741 		if (!USE_IRDA(sport)) {
742 			retval = request_irq(sport->rtsirq, imx_rtsint,
743 				     (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
744 				       IRQF_TRIGGER_FALLING |
745 				       IRQF_TRIGGER_RISING,
746 					DRIVER_NAME, sport);
747 			if (retval)
748 				goto error_out3;
749 		}
750 	} else {
751 		retval = request_irq(sport->port.irq, imx_int, 0,
752 				DRIVER_NAME, sport);
753 		if (retval) {
754 			free_irq(sport->port.irq, sport);
755 			goto error_out1;
756 		}
757 	}
758 
759 	/*
760 	 * Finally, clear and enable interrupts
761 	 */
762 	writel(USR1_RTSD, sport->port.membase + USR1);
763 
764 	temp = readl(sport->port.membase + UCR1);
765 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
766 
767 	if (USE_IRDA(sport)) {
768 		temp |= UCR1_IREN;
769 		temp &= ~(UCR1_RTSDEN);
770 	}
771 
772 	writel(temp, sport->port.membase + UCR1);
773 
774 	temp = readl(sport->port.membase + UCR2);
775 	temp |= (UCR2_RXEN | UCR2_TXEN);
776 	writel(temp, sport->port.membase + UCR2);
777 
778 	if (USE_IRDA(sport)) {
779 		/* clear RX-FIFO */
780 		int i = 64;
781 		while ((--i > 0) &&
782 			(readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
783 			barrier();
784 		}
785 	}
786 
787 	if (is_imx21_uart(sport)) {
788 		temp = readl(sport->port.membase + UCR3);
789 		temp |= IMX21_UCR3_RXDMUXSEL;
790 		writel(temp, sport->port.membase + UCR3);
791 	}
792 
793 	if (USE_IRDA(sport)) {
794 		temp = readl(sport->port.membase + UCR4);
795 		if (sport->irda_inv_rx)
796 			temp |= UCR4_INVR;
797 		else
798 			temp &= ~(UCR4_INVR);
799 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
800 
801 		temp = readl(sport->port.membase + UCR3);
802 		if (sport->irda_inv_tx)
803 			temp |= UCR3_INVT;
804 		else
805 			temp &= ~(UCR3_INVT);
806 		writel(temp, sport->port.membase + UCR3);
807 	}
808 
809 	/*
810 	 * Enable modem status interrupts
811 	 */
812 	spin_lock_irqsave(&sport->port.lock,flags);
813 	imx_enable_ms(&sport->port);
814 	spin_unlock_irqrestore(&sport->port.lock,flags);
815 
816 	if (USE_IRDA(sport)) {
817 		struct imxuart_platform_data *pdata;
818 		pdata = sport->port.dev->platform_data;
819 		sport->irda_inv_rx = pdata->irda_inv_rx;
820 		sport->irda_inv_tx = pdata->irda_inv_tx;
821 		sport->trcv_delay = pdata->transceiver_delay;
822 		if (pdata->irda_enable)
823 			pdata->irda_enable(1);
824 	}
825 
826 	return 0;
827 
828 error_out3:
829 	if (sport->txirq)
830 		free_irq(sport->txirq, sport);
831 error_out2:
832 	if (sport->rxirq)
833 		free_irq(sport->rxirq, sport);
834 error_out1:
835 	return retval;
836 }
837 
838 static void imx_shutdown(struct uart_port *port)
839 {
840 	struct imx_port *sport = (struct imx_port *)port;
841 	unsigned long temp;
842 
843 	temp = readl(sport->port.membase + UCR2);
844 	temp &= ~(UCR2_TXEN);
845 	writel(temp, sport->port.membase + UCR2);
846 
847 	if (USE_IRDA(sport)) {
848 		struct imxuart_platform_data *pdata;
849 		pdata = sport->port.dev->platform_data;
850 		if (pdata->irda_enable)
851 			pdata->irda_enable(0);
852 	}
853 
854 	/*
855 	 * Stop our timer.
856 	 */
857 	del_timer_sync(&sport->timer);
858 
859 	/*
860 	 * Free the interrupts
861 	 */
862 	if (sport->txirq > 0) {
863 		if (!USE_IRDA(sport))
864 			free_irq(sport->rtsirq, sport);
865 		free_irq(sport->txirq, sport);
866 		free_irq(sport->rxirq, sport);
867 	} else
868 		free_irq(sport->port.irq, sport);
869 
870 	/*
871 	 * Disable all interrupts, port and break condition.
872 	 */
873 
874 	temp = readl(sport->port.membase + UCR1);
875 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
876 	if (USE_IRDA(sport))
877 		temp &= ~(UCR1_IREN);
878 
879 	writel(temp, sport->port.membase + UCR1);
880 }
881 
882 static void
883 imx_set_termios(struct uart_port *port, struct ktermios *termios,
884 		   struct ktermios *old)
885 {
886 	struct imx_port *sport = (struct imx_port *)port;
887 	unsigned long flags;
888 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
889 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
890 	unsigned int div, ufcr;
891 	unsigned long num, denom;
892 	uint64_t tdiv64;
893 
894 	/*
895 	 * If we don't support modem control lines, don't allow
896 	 * these to be set.
897 	 */
898 	if (0) {
899 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
900 		termios->c_cflag |= CLOCAL;
901 	}
902 
903 	/*
904 	 * We only support CS7 and CS8.
905 	 */
906 	while ((termios->c_cflag & CSIZE) != CS7 &&
907 	       (termios->c_cflag & CSIZE) != CS8) {
908 		termios->c_cflag &= ~CSIZE;
909 		termios->c_cflag |= old_csize;
910 		old_csize = CS8;
911 	}
912 
913 	if ((termios->c_cflag & CSIZE) == CS8)
914 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
915 	else
916 		ucr2 = UCR2_SRST | UCR2_IRTS;
917 
918 	if (termios->c_cflag & CRTSCTS) {
919 		if( sport->have_rtscts ) {
920 			ucr2 &= ~UCR2_IRTS;
921 			ucr2 |= UCR2_CTSC;
922 		} else {
923 			termios->c_cflag &= ~CRTSCTS;
924 		}
925 	}
926 
927 	if (termios->c_cflag & CSTOPB)
928 		ucr2 |= UCR2_STPB;
929 	if (termios->c_cflag & PARENB) {
930 		ucr2 |= UCR2_PREN;
931 		if (termios->c_cflag & PARODD)
932 			ucr2 |= UCR2_PROE;
933 	}
934 
935 	del_timer_sync(&sport->timer);
936 
937 	/*
938 	 * Ask the core to calculate the divisor for us.
939 	 */
940 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
941 	quot = uart_get_divisor(port, baud);
942 
943 	spin_lock_irqsave(&sport->port.lock, flags);
944 
945 	sport->port.read_status_mask = 0;
946 	if (termios->c_iflag & INPCK)
947 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
948 	if (termios->c_iflag & (BRKINT | PARMRK))
949 		sport->port.read_status_mask |= URXD_BRK;
950 
951 	/*
952 	 * Characters to ignore
953 	 */
954 	sport->port.ignore_status_mask = 0;
955 	if (termios->c_iflag & IGNPAR)
956 		sport->port.ignore_status_mask |= URXD_PRERR;
957 	if (termios->c_iflag & IGNBRK) {
958 		sport->port.ignore_status_mask |= URXD_BRK;
959 		/*
960 		 * If we're ignoring parity and break indicators,
961 		 * ignore overruns too (for real raw support).
962 		 */
963 		if (termios->c_iflag & IGNPAR)
964 			sport->port.ignore_status_mask |= URXD_OVRRUN;
965 	}
966 
967 	/*
968 	 * Update the per-port timeout.
969 	 */
970 	uart_update_timeout(port, termios->c_cflag, baud);
971 
972 	/*
973 	 * disable interrupts and drain transmitter
974 	 */
975 	old_ucr1 = readl(sport->port.membase + UCR1);
976 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
977 			sport->port.membase + UCR1);
978 
979 	while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
980 		barrier();
981 
982 	/* then, disable everything */
983 	old_txrxen = readl(sport->port.membase + UCR2);
984 	writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
985 			sport->port.membase + UCR2);
986 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
987 
988 	if (USE_IRDA(sport)) {
989 		/*
990 		 * use maximum available submodule frequency to
991 		 * avoid missing short pulses due to low sampling rate
992 		 */
993 		div = 1;
994 	} else {
995 		div = sport->port.uartclk / (baud * 16);
996 		if (div > 7)
997 			div = 7;
998 		if (!div)
999 			div = 1;
1000 	}
1001 
1002 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1003 		1 << 16, 1 << 16, &num, &denom);
1004 
1005 	tdiv64 = sport->port.uartclk;
1006 	tdiv64 *= num;
1007 	do_div(tdiv64, denom * 16 * div);
1008 	tty_termios_encode_baud_rate(termios,
1009 				(speed_t)tdiv64, (speed_t)tdiv64);
1010 
1011 	num -= 1;
1012 	denom -= 1;
1013 
1014 	ufcr = readl(sport->port.membase + UFCR);
1015 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1016 	writel(ufcr, sport->port.membase + UFCR);
1017 
1018 	writel(num, sport->port.membase + UBIR);
1019 	writel(denom, sport->port.membase + UBMR);
1020 
1021 	if (is_imx21_uart(sport))
1022 		writel(sport->port.uartclk / div / 1000,
1023 				sport->port.membase + IMX21_ONEMS);
1024 
1025 	writel(old_ucr1, sport->port.membase + UCR1);
1026 
1027 	/* set the parity, stop bits and data size */
1028 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1029 
1030 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1031 		imx_enable_ms(&sport->port);
1032 
1033 	spin_unlock_irqrestore(&sport->port.lock, flags);
1034 }
1035 
1036 static const char *imx_type(struct uart_port *port)
1037 {
1038 	struct imx_port *sport = (struct imx_port *)port;
1039 
1040 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1041 }
1042 
1043 /*
1044  * Release the memory region(s) being used by 'port'.
1045  */
1046 static void imx_release_port(struct uart_port *port)
1047 {
1048 	struct platform_device *pdev = to_platform_device(port->dev);
1049 	struct resource *mmres;
1050 
1051 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1052 	release_mem_region(mmres->start, resource_size(mmres));
1053 }
1054 
1055 /*
1056  * Request the memory region(s) being used by 'port'.
1057  */
1058 static int imx_request_port(struct uart_port *port)
1059 {
1060 	struct platform_device *pdev = to_platform_device(port->dev);
1061 	struct resource *mmres;
1062 	void *ret;
1063 
1064 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1065 	if (!mmres)
1066 		return -ENODEV;
1067 
1068 	ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
1069 
1070 	return  ret ? 0 : -EBUSY;
1071 }
1072 
1073 /*
1074  * Configure/autoconfigure the port.
1075  */
1076 static void imx_config_port(struct uart_port *port, int flags)
1077 {
1078 	struct imx_port *sport = (struct imx_port *)port;
1079 
1080 	if (flags & UART_CONFIG_TYPE &&
1081 	    imx_request_port(&sport->port) == 0)
1082 		sport->port.type = PORT_IMX;
1083 }
1084 
1085 /*
1086  * Verify the new serial_struct (for TIOCSSERIAL).
1087  * The only change we allow are to the flags and type, and
1088  * even then only between PORT_IMX and PORT_UNKNOWN
1089  */
1090 static int
1091 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1092 {
1093 	struct imx_port *sport = (struct imx_port *)port;
1094 	int ret = 0;
1095 
1096 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1097 		ret = -EINVAL;
1098 	if (sport->port.irq != ser->irq)
1099 		ret = -EINVAL;
1100 	if (ser->io_type != UPIO_MEM)
1101 		ret = -EINVAL;
1102 	if (sport->port.uartclk / 16 != ser->baud_base)
1103 		ret = -EINVAL;
1104 	if ((void *)sport->port.mapbase != ser->iomem_base)
1105 		ret = -EINVAL;
1106 	if (sport->port.iobase != ser->port)
1107 		ret = -EINVAL;
1108 	if (ser->hub6 != 0)
1109 		ret = -EINVAL;
1110 	return ret;
1111 }
1112 
1113 #if defined(CONFIG_CONSOLE_POLL)
1114 static int imx_poll_get_char(struct uart_port *port)
1115 {
1116 	struct imx_port_ucrs old_ucr;
1117 	unsigned int status;
1118 	unsigned char c;
1119 
1120 	/* save control registers */
1121 	imx_port_ucrs_save(port, &old_ucr);
1122 
1123 	/* disable interrupts */
1124 	writel(UCR1_UARTEN, port->membase + UCR1);
1125 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1126 	       port->membase + UCR2);
1127 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1128 	       port->membase + UCR3);
1129 
1130 	/* poll */
1131 	do {
1132 		status = readl(port->membase + USR2);
1133 	} while (~status & USR2_RDR);
1134 
1135 	/* read */
1136 	c = readl(port->membase + URXD0);
1137 
1138 	/* restore control registers */
1139 	imx_port_ucrs_restore(port, &old_ucr);
1140 
1141 	return c;
1142 }
1143 
1144 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1145 {
1146 	struct imx_port_ucrs old_ucr;
1147 	unsigned int status;
1148 
1149 	/* save control registers */
1150 	imx_port_ucrs_save(port, &old_ucr);
1151 
1152 	/* disable interrupts */
1153 	writel(UCR1_UARTEN, port->membase + UCR1);
1154 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1155 	       port->membase + UCR2);
1156 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1157 	       port->membase + UCR3);
1158 
1159 	/* drain */
1160 	do {
1161 		status = readl(port->membase + USR1);
1162 	} while (~status & USR1_TRDY);
1163 
1164 	/* write */
1165 	writel(c, port->membase + URTX0);
1166 
1167 	/* flush */
1168 	do {
1169 		status = readl(port->membase + USR2);
1170 	} while (~status & USR2_TXDC);
1171 
1172 	/* restore control registers */
1173 	imx_port_ucrs_restore(port, &old_ucr);
1174 }
1175 #endif
1176 
1177 static struct uart_ops imx_pops = {
1178 	.tx_empty	= imx_tx_empty,
1179 	.set_mctrl	= imx_set_mctrl,
1180 	.get_mctrl	= imx_get_mctrl,
1181 	.stop_tx	= imx_stop_tx,
1182 	.start_tx	= imx_start_tx,
1183 	.stop_rx	= imx_stop_rx,
1184 	.enable_ms	= imx_enable_ms,
1185 	.break_ctl	= imx_break_ctl,
1186 	.startup	= imx_startup,
1187 	.shutdown	= imx_shutdown,
1188 	.set_termios	= imx_set_termios,
1189 	.type		= imx_type,
1190 	.release_port	= imx_release_port,
1191 	.request_port	= imx_request_port,
1192 	.config_port	= imx_config_port,
1193 	.verify_port	= imx_verify_port,
1194 #if defined(CONFIG_CONSOLE_POLL)
1195 	.poll_get_char  = imx_poll_get_char,
1196 	.poll_put_char  = imx_poll_put_char,
1197 #endif
1198 };
1199 
1200 static struct imx_port *imx_ports[UART_NR];
1201 
1202 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1203 static void imx_console_putchar(struct uart_port *port, int ch)
1204 {
1205 	struct imx_port *sport = (struct imx_port *)port;
1206 
1207 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1208 		barrier();
1209 
1210 	writel(ch, sport->port.membase + URTX0);
1211 }
1212 
1213 /*
1214  * Interrupts are disabled on entering
1215  */
1216 static void
1217 imx_console_write(struct console *co, const char *s, unsigned int count)
1218 {
1219 	struct imx_port *sport = imx_ports[co->index];
1220 	struct imx_port_ucrs old_ucr;
1221 	unsigned int ucr1;
1222 
1223 	/*
1224 	 *	First, save UCR1/2/3 and then disable interrupts
1225 	 */
1226 	imx_port_ucrs_save(&sport->port, &old_ucr);
1227 	ucr1 = old_ucr.ucr1;
1228 
1229 	if (is_imx1_uart(sport))
1230 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1231 	ucr1 |= UCR1_UARTEN;
1232 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1233 
1234 	writel(ucr1, sport->port.membase + UCR1);
1235 
1236 	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1237 
1238 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1239 
1240 	/*
1241 	 *	Finally, wait for transmitter to become empty
1242 	 *	and restore UCR1/2/3
1243 	 */
1244 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1245 
1246 	imx_port_ucrs_restore(&sport->port, &old_ucr);
1247 }
1248 
1249 /*
1250  * If the port was already initialised (eg, by a boot loader),
1251  * try to determine the current setup.
1252  */
1253 static void __init
1254 imx_console_get_options(struct imx_port *sport, int *baud,
1255 			   int *parity, int *bits)
1256 {
1257 
1258 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1259 		/* ok, the port was enabled */
1260 		unsigned int ucr2, ubir,ubmr, uartclk;
1261 		unsigned int baud_raw;
1262 		unsigned int ucfr_rfdiv;
1263 
1264 		ucr2 = readl(sport->port.membase + UCR2);
1265 
1266 		*parity = 'n';
1267 		if (ucr2 & UCR2_PREN) {
1268 			if (ucr2 & UCR2_PROE)
1269 				*parity = 'o';
1270 			else
1271 				*parity = 'e';
1272 		}
1273 
1274 		if (ucr2 & UCR2_WS)
1275 			*bits = 8;
1276 		else
1277 			*bits = 7;
1278 
1279 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1280 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1281 
1282 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1283 		if (ucfr_rfdiv == 6)
1284 			ucfr_rfdiv = 7;
1285 		else
1286 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1287 
1288 		uartclk = clk_get_rate(sport->clk);
1289 		uartclk /= ucfr_rfdiv;
1290 
1291 		{	/*
1292 			 * The next code provides exact computation of
1293 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1294 			 * without need of float support or long long division,
1295 			 * which would be required to prevent 32bit arithmetic overflow
1296 			 */
1297 			unsigned int mul = ubir + 1;
1298 			unsigned int div = 16 * (ubmr + 1);
1299 			unsigned int rem = uartclk % div;
1300 
1301 			baud_raw = (uartclk / div) * mul;
1302 			baud_raw += (rem * mul + div / 2) / div;
1303 			*baud = (baud_raw + 50) / 100 * 100;
1304 		}
1305 
1306 		if(*baud != baud_raw)
1307 			printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
1308 				baud_raw, *baud);
1309 	}
1310 }
1311 
1312 static int __init
1313 imx_console_setup(struct console *co, char *options)
1314 {
1315 	struct imx_port *sport;
1316 	int baud = 9600;
1317 	int bits = 8;
1318 	int parity = 'n';
1319 	int flow = 'n';
1320 
1321 	/*
1322 	 * Check whether an invalid uart number has been specified, and
1323 	 * if so, search for the first available port that does have
1324 	 * console support.
1325 	 */
1326 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1327 		co->index = 0;
1328 	sport = imx_ports[co->index];
1329 	if(sport == NULL)
1330 		return -ENODEV;
1331 
1332 	if (options)
1333 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1334 	else
1335 		imx_console_get_options(sport, &baud, &parity, &bits);
1336 
1337 	imx_setup_ufcr(sport, 0);
1338 
1339 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
1340 }
1341 
1342 static struct uart_driver imx_reg;
1343 static struct console imx_console = {
1344 	.name		= DEV_NAME,
1345 	.write		= imx_console_write,
1346 	.device		= uart_console_device,
1347 	.setup		= imx_console_setup,
1348 	.flags		= CON_PRINTBUFFER,
1349 	.index		= -1,
1350 	.data		= &imx_reg,
1351 };
1352 
1353 #define IMX_CONSOLE	&imx_console
1354 #else
1355 #define IMX_CONSOLE	NULL
1356 #endif
1357 
1358 static struct uart_driver imx_reg = {
1359 	.owner          = THIS_MODULE,
1360 	.driver_name    = DRIVER_NAME,
1361 	.dev_name       = DEV_NAME,
1362 	.major          = SERIAL_IMX_MAJOR,
1363 	.minor          = MINOR_START,
1364 	.nr             = ARRAY_SIZE(imx_ports),
1365 	.cons           = IMX_CONSOLE,
1366 };
1367 
1368 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1369 {
1370 	struct imx_port *sport = platform_get_drvdata(dev);
1371 	unsigned int val;
1372 
1373 	/* enable wakeup from i.MX UART */
1374 	val = readl(sport->port.membase + UCR3);
1375 	val |= UCR3_AWAKEN;
1376 	writel(val, sport->port.membase + UCR3);
1377 
1378 	if (sport)
1379 		uart_suspend_port(&imx_reg, &sport->port);
1380 
1381 	return 0;
1382 }
1383 
1384 static int serial_imx_resume(struct platform_device *dev)
1385 {
1386 	struct imx_port *sport = platform_get_drvdata(dev);
1387 	unsigned int val;
1388 
1389 	/* disable wakeup from i.MX UART */
1390 	val = readl(sport->port.membase + UCR3);
1391 	val &= ~UCR3_AWAKEN;
1392 	writel(val, sport->port.membase + UCR3);
1393 
1394 	if (sport)
1395 		uart_resume_port(&imx_reg, &sport->port);
1396 
1397 	return 0;
1398 }
1399 
1400 #ifdef CONFIG_OF
1401 /*
1402  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1403  * could successfully get all information from dt or a negative errno.
1404  */
1405 static int serial_imx_probe_dt(struct imx_port *sport,
1406 		struct platform_device *pdev)
1407 {
1408 	struct device_node *np = pdev->dev.of_node;
1409 	const struct of_device_id *of_id =
1410 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1411 	int ret;
1412 
1413 	if (!np)
1414 		/* no device tree device */
1415 		return 1;
1416 
1417 	ret = of_alias_get_id(np, "serial");
1418 	if (ret < 0) {
1419 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1420 		return ret;
1421 	}
1422 	sport->port.line = ret;
1423 
1424 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1425 		sport->have_rtscts = 1;
1426 
1427 	if (of_get_property(np, "fsl,irda-mode", NULL))
1428 		sport->use_irda = 1;
1429 
1430 	sport->devdata = of_id->data;
1431 
1432 	return 0;
1433 }
1434 #else
1435 static inline int serial_imx_probe_dt(struct imx_port *sport,
1436 		struct platform_device *pdev)
1437 {
1438 	return 1;
1439 }
1440 #endif
1441 
1442 static void serial_imx_probe_pdata(struct imx_port *sport,
1443 		struct platform_device *pdev)
1444 {
1445 	struct imxuart_platform_data *pdata = pdev->dev.platform_data;
1446 
1447 	sport->port.line = pdev->id;
1448 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1449 
1450 	if (!pdata)
1451 		return;
1452 
1453 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1454 		sport->have_rtscts = 1;
1455 
1456 	if (pdata->flags & IMXUART_IRDA)
1457 		sport->use_irda = 1;
1458 }
1459 
1460 static int serial_imx_probe(struct platform_device *pdev)
1461 {
1462 	struct imx_port *sport;
1463 	struct imxuart_platform_data *pdata;
1464 	void __iomem *base;
1465 	int ret = 0;
1466 	struct resource *res;
1467 
1468 	sport = kzalloc(sizeof(*sport), GFP_KERNEL);
1469 	if (!sport)
1470 		return -ENOMEM;
1471 
1472 	ret = serial_imx_probe_dt(sport, pdev);
1473 	if (ret > 0)
1474 		serial_imx_probe_pdata(sport, pdev);
1475 	else if (ret < 0)
1476 		goto free;
1477 
1478 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1479 	if (!res) {
1480 		ret = -ENODEV;
1481 		goto free;
1482 	}
1483 
1484 	base = ioremap(res->start, PAGE_SIZE);
1485 	if (!base) {
1486 		ret = -ENOMEM;
1487 		goto free;
1488 	}
1489 
1490 	sport->port.dev = &pdev->dev;
1491 	sport->port.mapbase = res->start;
1492 	sport->port.membase = base;
1493 	sport->port.type = PORT_IMX,
1494 	sport->port.iotype = UPIO_MEM;
1495 	sport->port.irq = platform_get_irq(pdev, 0);
1496 	sport->rxirq = platform_get_irq(pdev, 0);
1497 	sport->txirq = platform_get_irq(pdev, 1);
1498 	sport->rtsirq = platform_get_irq(pdev, 2);
1499 	sport->port.fifosize = 32;
1500 	sport->port.ops = &imx_pops;
1501 	sport->port.flags = UPF_BOOT_AUTOCONF;
1502 	init_timer(&sport->timer);
1503 	sport->timer.function = imx_timeout;
1504 	sport->timer.data     = (unsigned long)sport;
1505 
1506 	sport->clk = clk_get(&pdev->dev, "uart");
1507 	if (IS_ERR(sport->clk)) {
1508 		ret = PTR_ERR(sport->clk);
1509 		goto unmap;
1510 	}
1511 	clk_prepare_enable(sport->clk);
1512 
1513 	sport->port.uartclk = clk_get_rate(sport->clk);
1514 
1515 	imx_ports[sport->port.line] = sport;
1516 
1517 	pdata = pdev->dev.platform_data;
1518 	if (pdata && pdata->init) {
1519 		ret = pdata->init(pdev);
1520 		if (ret)
1521 			goto clkput;
1522 	}
1523 
1524 	ret = uart_add_one_port(&imx_reg, &sport->port);
1525 	if (ret)
1526 		goto deinit;
1527 	platform_set_drvdata(pdev, &sport->port);
1528 
1529 	return 0;
1530 deinit:
1531 	if (pdata && pdata->exit)
1532 		pdata->exit(pdev);
1533 clkput:
1534 	clk_disable_unprepare(sport->clk);
1535 	clk_put(sport->clk);
1536 unmap:
1537 	iounmap(sport->port.membase);
1538 free:
1539 	kfree(sport);
1540 
1541 	return ret;
1542 }
1543 
1544 static int serial_imx_remove(struct platform_device *pdev)
1545 {
1546 	struct imxuart_platform_data *pdata;
1547 	struct imx_port *sport = platform_get_drvdata(pdev);
1548 
1549 	pdata = pdev->dev.platform_data;
1550 
1551 	platform_set_drvdata(pdev, NULL);
1552 
1553 	if (sport) {
1554 		uart_remove_one_port(&imx_reg, &sport->port);
1555 		clk_disable_unprepare(sport->clk);
1556 		clk_put(sport->clk);
1557 	}
1558 
1559 	if (pdata && pdata->exit)
1560 		pdata->exit(pdev);
1561 
1562 	iounmap(sport->port.membase);
1563 	kfree(sport);
1564 
1565 	return 0;
1566 }
1567 
1568 static struct platform_driver serial_imx_driver = {
1569 	.probe		= serial_imx_probe,
1570 	.remove		= serial_imx_remove,
1571 
1572 	.suspend	= serial_imx_suspend,
1573 	.resume		= serial_imx_resume,
1574 	.id_table	= imx_uart_devtype,
1575 	.driver		= {
1576 		.name	= "imx-uart",
1577 		.owner	= THIS_MODULE,
1578 		.of_match_table = imx_uart_dt_ids,
1579 	},
1580 };
1581 
1582 static int __init imx_serial_init(void)
1583 {
1584 	int ret;
1585 
1586 	printk(KERN_INFO "Serial: IMX driver\n");
1587 
1588 	ret = uart_register_driver(&imx_reg);
1589 	if (ret)
1590 		return ret;
1591 
1592 	ret = platform_driver_register(&serial_imx_driver);
1593 	if (ret != 0)
1594 		uart_unregister_driver(&imx_reg);
1595 
1596 	return ret;
1597 }
1598 
1599 static void __exit imx_serial_exit(void)
1600 {
1601 	platform_driver_unregister(&serial_imx_driver);
1602 	uart_unregister_driver(&imx_reg);
1603 }
1604 
1605 module_init(imx_serial_init);
1606 module_exit(imx_serial_exit);
1607 
1608 MODULE_AUTHOR("Sascha Hauer");
1609 MODULE_DESCRIPTION("IMX generic serial port driver");
1610 MODULE_LICENSE("GPL");
1611 MODULE_ALIAS("platform:imx-uart");
1612