xref: /openbmc/linux/drivers/tty/serial/imx.c (revision 33a03aad)
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 #include <linux/pinctrl/consumer.h>
51 
52 #include <asm/io.h>
53 #include <asm/irq.h>
54 #include <mach/imx-uart.h>
55 
56 /* Register definitions */
57 #define URXD0 0x0  /* Receiver Register */
58 #define URTX0 0x40 /* Transmitter Register */
59 #define UCR1  0x80 /* Control Register 1 */
60 #define UCR2  0x84 /* Control Register 2 */
61 #define UCR3  0x88 /* Control Register 3 */
62 #define UCR4  0x8c /* Control Register 4 */
63 #define UFCR  0x90 /* FIFO Control Register */
64 #define USR1  0x94 /* Status Register 1 */
65 #define USR2  0x98 /* Status Register 2 */
66 #define UESC  0x9c /* Escape Character Register */
67 #define UTIM  0xa0 /* Escape Timer Register */
68 #define UBIR  0xa4 /* BRM Incremental Register */
69 #define UBMR  0xa8 /* BRM Modulator Register */
70 #define UBRC  0xac /* Baud Rate Count Register */
71 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
72 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
73 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
74 
75 /* UART Control Register Bit Fields.*/
76 #define  URXD_CHARRDY    (1<<15)
77 #define  URXD_ERR        (1<<14)
78 #define  URXD_OVRRUN     (1<<13)
79 #define  URXD_FRMERR     (1<<12)
80 #define  URXD_BRK        (1<<11)
81 #define  URXD_PRERR      (1<<10)
82 #define  UCR1_ADEN       (1<<15) /* Auto detect interrupt */
83 #define  UCR1_ADBR       (1<<14) /* Auto detect baud rate */
84 #define  UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
85 #define  UCR1_IDEN       (1<<12) /* Idle condition interrupt */
86 #define  UCR1_RRDYEN     (1<<9)	 /* Recv ready interrupt enable */
87 #define  UCR1_RDMAEN     (1<<8)	 /* Recv ready DMA enable */
88 #define  UCR1_IREN       (1<<7)	 /* Infrared interface enable */
89 #define  UCR1_TXMPTYEN   (1<<6)	 /* Transimitter empty interrupt enable */
90 #define  UCR1_RTSDEN     (1<<5)	 /* RTS delta interrupt enable */
91 #define  UCR1_SNDBRK     (1<<4)	 /* Send break */
92 #define  UCR1_TDMAEN     (1<<3)	 /* Transmitter ready DMA enable */
93 #define  IMX1_UCR1_UARTCLKEN  (1<<2)  /* UART clock enabled, i.mx1 only */
94 #define  UCR1_DOZE       (1<<1)	 /* Doze */
95 #define  UCR1_UARTEN     (1<<0)	 /* UART enabled */
96 #define  UCR2_ESCI     	 (1<<15) /* Escape seq interrupt enable */
97 #define  UCR2_IRTS  	 (1<<14) /* Ignore RTS pin */
98 #define  UCR2_CTSC  	 (1<<13) /* CTS pin control */
99 #define  UCR2_CTS        (1<<12) /* Clear to send */
100 #define  UCR2_ESCEN      (1<<11) /* Escape enable */
101 #define  UCR2_PREN       (1<<8)  /* Parity enable */
102 #define  UCR2_PROE       (1<<7)  /* Parity odd/even */
103 #define  UCR2_STPB       (1<<6)	 /* Stop */
104 #define  UCR2_WS         (1<<5)	 /* Word size */
105 #define  UCR2_RTSEN      (1<<4)	 /* Request to send interrupt enable */
106 #define  UCR2_ATEN       (1<<3)  /* Aging Timer Enable */
107 #define  UCR2_TXEN       (1<<2)	 /* Transmitter enabled */
108 #define  UCR2_RXEN       (1<<1)	 /* Receiver enabled */
109 #define  UCR2_SRST 	 (1<<0)	 /* SW reset */
110 #define  UCR3_DTREN 	 (1<<13) /* DTR interrupt enable */
111 #define  UCR3_PARERREN   (1<<12) /* Parity enable */
112 #define  UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
113 #define  UCR3_DSR        (1<<10) /* Data set ready */
114 #define  UCR3_DCD        (1<<9)  /* Data carrier detect */
115 #define  UCR3_RI         (1<<8)  /* Ring indicator */
116 #define  UCR3_TIMEOUTEN  (1<<7)  /* Timeout interrupt enable */
117 #define  UCR3_RXDSEN	 (1<<6)  /* Receive status interrupt enable */
118 #define  UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
119 #define  UCR3_AWAKEN	 (1<<4)  /* Async wake interrupt enable */
120 #define  IMX21_UCR3_RXDMUXSEL	 (1<<2)  /* RXD Muxed Input Select */
121 #define  UCR3_INVT  	 (1<<1)  /* Inverted Infrared transmission */
122 #define  UCR3_BPEN  	 (1<<0)  /* Preset registers enable */
123 #define  UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
124 #define  UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
125 #define  UCR4_INVR  	 (1<<9)  /* Inverted infrared reception */
126 #define  UCR4_ENIRI 	 (1<<8)  /* Serial infrared interrupt enable */
127 #define  UCR4_WKEN  	 (1<<7)  /* Wake interrupt enable */
128 #define  UCR4_REF16 	 (1<<6)  /* Ref freq 16 MHz */
129 #define  UCR4_IRSC  	 (1<<5)  /* IR special case */
130 #define  UCR4_TCEN  	 (1<<3)  /* Transmit complete interrupt enable */
131 #define  UCR4_BKEN  	 (1<<2)  /* Break condition interrupt enable */
132 #define  UCR4_OREN  	 (1<<1)  /* Receiver overrun interrupt enable */
133 #define  UCR4_DREN  	 (1<<0)  /* Recv data ready interrupt enable */
134 #define  UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
135 #define  UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
136 #define  UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
137 #define  UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
138 #define  USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
139 #define  USR1_RTSS  	 (1<<14) /* RTS pin status */
140 #define  USR1_TRDY  	 (1<<13) /* Transmitter ready interrupt/dma flag */
141 #define  USR1_RTSD  	 (1<<12) /* RTS delta */
142 #define  USR1_ESCF  	 (1<<11) /* Escape seq interrupt flag */
143 #define  USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
144 #define  USR1_RRDY       (1<<9)	 /* Receiver ready interrupt/dma flag */
145 #define  USR1_TIMEOUT    (1<<7)	 /* Receive timeout interrupt status */
146 #define  USR1_RXDS  	 (1<<6)	 /* Receiver idle interrupt flag */
147 #define  USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
148 #define  USR1_AWAKE 	 (1<<4)	 /* Aysnc wake interrupt flag */
149 #define  USR2_ADET  	 (1<<15) /* Auto baud rate detect complete */
150 #define  USR2_TXFE  	 (1<<14) /* Transmit buffer FIFO empty */
151 #define  USR2_DTRF  	 (1<<13) /* DTR edge interrupt flag */
152 #define  USR2_IDLE  	 (1<<12) /* Idle condition */
153 #define  USR2_IRINT 	 (1<<8)	 /* Serial infrared interrupt flag */
154 #define  USR2_WAKE  	 (1<<7)	 /* Wake */
155 #define  USR2_RTSF  	 (1<<4)	 /* RTS edge interrupt flag */
156 #define  USR2_TXDC  	 (1<<3)	 /* Transmitter complete */
157 #define  USR2_BRCD  	 (1<<2)	 /* Break condition */
158 #define  USR2_ORE        (1<<1)	 /* Overrun error */
159 #define  USR2_RDR        (1<<0)	 /* Recv data ready */
160 #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
161 #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
162 #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
163 #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
164 #define  UTS_TXFULL 	 (1<<4)	 /* TxFIFO full */
165 #define  UTS_RXFULL 	 (1<<3)	 /* RxFIFO full */
166 #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
167 
168 /* We've been assigned a range on the "Low-density serial ports" major */
169 #define SERIAL_IMX_MAJOR        207
170 #define MINOR_START	        16
171 #define DEV_NAME		"ttymxc"
172 #define MAX_INTERNAL_IRQ	MXC_INTERNAL_IRQS
173 
174 /*
175  * This determines how often we check the modem status signals
176  * for any change.  They generally aren't connected to an IRQ
177  * so we have to poll them.  We also check immediately before
178  * filling the TX fifo incase CTS has been dropped.
179  */
180 #define MCTRL_TIMEOUT	(250*HZ/1000)
181 
182 #define DRIVER_NAME "IMX-uart"
183 
184 #define UART_NR 8
185 
186 /* i.mx21 type uart runs on all i.mx except i.mx1 */
187 enum imx_uart_type {
188 	IMX1_UART,
189 	IMX21_UART,
190 };
191 
192 /* device type dependent stuff */
193 struct imx_uart_data {
194 	unsigned uts_reg;
195 	enum imx_uart_type devtype;
196 };
197 
198 struct imx_port {
199 	struct uart_port	port;
200 	struct timer_list	timer;
201 	unsigned int		old_status;
202 	int			txirq,rxirq,rtsirq;
203 	unsigned int		have_rtscts:1;
204 	unsigned int		use_irda:1;
205 	unsigned int		irda_inv_rx:1;
206 	unsigned int		irda_inv_tx:1;
207 	unsigned short		trcv_delay; /* transceiver delay */
208 	struct clk		*clk_ipg;
209 	struct clk		*clk_per;
210 	struct imx_uart_data	*devdata;
211 };
212 
213 struct imx_port_ucrs {
214 	unsigned int	ucr1;
215 	unsigned int	ucr2;
216 	unsigned int	ucr3;
217 };
218 
219 #ifdef CONFIG_IRDA
220 #define USE_IRDA(sport)	((sport)->use_irda)
221 #else
222 #define USE_IRDA(sport)	(0)
223 #endif
224 
225 static struct imx_uart_data imx_uart_devdata[] = {
226 	[IMX1_UART] = {
227 		.uts_reg = IMX1_UTS,
228 		.devtype = IMX1_UART,
229 	},
230 	[IMX21_UART] = {
231 		.uts_reg = IMX21_UTS,
232 		.devtype = IMX21_UART,
233 	},
234 };
235 
236 static struct platform_device_id imx_uart_devtype[] = {
237 	{
238 		.name = "imx1-uart",
239 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
240 	}, {
241 		.name = "imx21-uart",
242 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
243 	}, {
244 		/* sentinel */
245 	}
246 };
247 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
248 
249 static struct of_device_id imx_uart_dt_ids[] = {
250 	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
251 	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
252 	{ /* sentinel */ }
253 };
254 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
255 
256 static inline unsigned uts_reg(struct imx_port *sport)
257 {
258 	return sport->devdata->uts_reg;
259 }
260 
261 static inline int is_imx1_uart(struct imx_port *sport)
262 {
263 	return sport->devdata->devtype == IMX1_UART;
264 }
265 
266 static inline int is_imx21_uart(struct imx_port *sport)
267 {
268 	return sport->devdata->devtype == IMX21_UART;
269 }
270 
271 /*
272  * Save and restore functions for UCR1, UCR2 and UCR3 registers
273  */
274 static void imx_port_ucrs_save(struct uart_port *port,
275 			       struct imx_port_ucrs *ucr)
276 {
277 	/* save control registers */
278 	ucr->ucr1 = readl(port->membase + UCR1);
279 	ucr->ucr2 = readl(port->membase + UCR2);
280 	ucr->ucr3 = readl(port->membase + UCR3);
281 }
282 
283 static void imx_port_ucrs_restore(struct uart_port *port,
284 				  struct imx_port_ucrs *ucr)
285 {
286 	/* restore control registers */
287 	writel(ucr->ucr1, port->membase + UCR1);
288 	writel(ucr->ucr2, port->membase + UCR2);
289 	writel(ucr->ucr3, port->membase + UCR3);
290 }
291 
292 /*
293  * Handle any change of modem status signal since we were last called.
294  */
295 static void imx_mctrl_check(struct imx_port *sport)
296 {
297 	unsigned int status, changed;
298 
299 	status = sport->port.ops->get_mctrl(&sport->port);
300 	changed = status ^ sport->old_status;
301 
302 	if (changed == 0)
303 		return;
304 
305 	sport->old_status = status;
306 
307 	if (changed & TIOCM_RI)
308 		sport->port.icount.rng++;
309 	if (changed & TIOCM_DSR)
310 		sport->port.icount.dsr++;
311 	if (changed & TIOCM_CAR)
312 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
313 	if (changed & TIOCM_CTS)
314 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
315 
316 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
317 }
318 
319 /*
320  * This is our per-port timeout handler, for checking the
321  * modem status signals.
322  */
323 static void imx_timeout(unsigned long data)
324 {
325 	struct imx_port *sport = (struct imx_port *)data;
326 	unsigned long flags;
327 
328 	if (sport->port.state) {
329 		spin_lock_irqsave(&sport->port.lock, flags);
330 		imx_mctrl_check(sport);
331 		spin_unlock_irqrestore(&sport->port.lock, flags);
332 
333 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
334 	}
335 }
336 
337 /*
338  * interrupts disabled on entry
339  */
340 static void imx_stop_tx(struct uart_port *port)
341 {
342 	struct imx_port *sport = (struct imx_port *)port;
343 	unsigned long temp;
344 
345 	if (USE_IRDA(sport)) {
346 		/* half duplex - wait for end of transmission */
347 		int n = 256;
348 		while ((--n > 0) &&
349 		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
350 			udelay(5);
351 			barrier();
352 		}
353 		/*
354 		 * irda transceiver - wait a bit more to avoid
355 		 * cutoff, hardware dependent
356 		 */
357 		udelay(sport->trcv_delay);
358 
359 		/*
360 		 * half duplex - reactivate receive mode,
361 		 * flush receive pipe echo crap
362 		 */
363 		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
364 			temp = readl(sport->port.membase + UCR1);
365 			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
366 			writel(temp, sport->port.membase + UCR1);
367 
368 			temp = readl(sport->port.membase + UCR4);
369 			temp &= ~(UCR4_TCEN);
370 			writel(temp, sport->port.membase + UCR4);
371 
372 			while (readl(sport->port.membase + URXD0) &
373 			       URXD_CHARRDY)
374 				barrier();
375 
376 			temp = readl(sport->port.membase + UCR1);
377 			temp |= UCR1_RRDYEN;
378 			writel(temp, sport->port.membase + UCR1);
379 
380 			temp = readl(sport->port.membase + UCR4);
381 			temp |= UCR4_DREN;
382 			writel(temp, sport->port.membase + UCR4);
383 		}
384 		return;
385 	}
386 
387 	temp = readl(sport->port.membase + UCR1);
388 	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
389 }
390 
391 /*
392  * interrupts disabled on entry
393  */
394 static void imx_stop_rx(struct uart_port *port)
395 {
396 	struct imx_port *sport = (struct imx_port *)port;
397 	unsigned long temp;
398 
399 	temp = readl(sport->port.membase + UCR2);
400 	writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
401 }
402 
403 /*
404  * Set the modem control timer to fire immediately.
405  */
406 static void imx_enable_ms(struct uart_port *port)
407 {
408 	struct imx_port *sport = (struct imx_port *)port;
409 
410 	mod_timer(&sport->timer, jiffies);
411 }
412 
413 static inline void imx_transmit_buffer(struct imx_port *sport)
414 {
415 	struct circ_buf *xmit = &sport->port.state->xmit;
416 
417 	while (!uart_circ_empty(xmit) &&
418 			!(readl(sport->port.membase + uts_reg(sport))
419 				& UTS_TXFULL)) {
420 		/* send xmit->buf[xmit->tail]
421 		 * out the port here */
422 		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
423 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
424 		sport->port.icount.tx++;
425 	}
426 
427 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
428 		uart_write_wakeup(&sport->port);
429 
430 	if (uart_circ_empty(xmit))
431 		imx_stop_tx(&sport->port);
432 }
433 
434 /*
435  * interrupts disabled on entry
436  */
437 static void imx_start_tx(struct uart_port *port)
438 {
439 	struct imx_port *sport = (struct imx_port *)port;
440 	unsigned long temp;
441 
442 	if (USE_IRDA(sport)) {
443 		/* half duplex in IrDA mode; have to disable receive mode */
444 		temp = readl(sport->port.membase + UCR4);
445 		temp &= ~(UCR4_DREN);
446 		writel(temp, sport->port.membase + UCR4);
447 
448 		temp = readl(sport->port.membase + UCR1);
449 		temp &= ~(UCR1_RRDYEN);
450 		writel(temp, sport->port.membase + UCR1);
451 	}
452 
453 	temp = readl(sport->port.membase + UCR1);
454 	writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
455 
456 	if (USE_IRDA(sport)) {
457 		temp = readl(sport->port.membase + UCR1);
458 		temp |= UCR1_TRDYEN;
459 		writel(temp, sport->port.membase + UCR1);
460 
461 		temp = readl(sport->port.membase + UCR4);
462 		temp |= UCR4_TCEN;
463 		writel(temp, sport->port.membase + UCR4);
464 	}
465 
466 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
467 		imx_transmit_buffer(sport);
468 }
469 
470 static irqreturn_t imx_rtsint(int irq, void *dev_id)
471 {
472 	struct imx_port *sport = dev_id;
473 	unsigned int val;
474 	unsigned long flags;
475 
476 	spin_lock_irqsave(&sport->port.lock, flags);
477 
478 	writel(USR1_RTSD, sport->port.membase + USR1);
479 	val = readl(sport->port.membase + USR1) & USR1_RTSS;
480 	uart_handle_cts_change(&sport->port, !!val);
481 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
482 
483 	spin_unlock_irqrestore(&sport->port.lock, flags);
484 	return IRQ_HANDLED;
485 }
486 
487 static irqreturn_t imx_txint(int irq, void *dev_id)
488 {
489 	struct imx_port *sport = dev_id;
490 	struct circ_buf *xmit = &sport->port.state->xmit;
491 	unsigned long flags;
492 
493 	spin_lock_irqsave(&sport->port.lock,flags);
494 	if (sport->port.x_char)
495 	{
496 		/* Send next char */
497 		writel(sport->port.x_char, sport->port.membase + URTX0);
498 		goto out;
499 	}
500 
501 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
502 		imx_stop_tx(&sport->port);
503 		goto out;
504 	}
505 
506 	imx_transmit_buffer(sport);
507 
508 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
509 		uart_write_wakeup(&sport->port);
510 
511 out:
512 	spin_unlock_irqrestore(&sport->port.lock,flags);
513 	return IRQ_HANDLED;
514 }
515 
516 static irqreturn_t imx_rxint(int irq, void *dev_id)
517 {
518 	struct imx_port *sport = dev_id;
519 	unsigned int rx,flg,ignored = 0;
520 	struct tty_struct *tty = sport->port.state->port.tty;
521 	unsigned long flags, temp;
522 
523 	spin_lock_irqsave(&sport->port.lock,flags);
524 
525 	while (readl(sport->port.membase + USR2) & USR2_RDR) {
526 		flg = TTY_NORMAL;
527 		sport->port.icount.rx++;
528 
529 		rx = readl(sport->port.membase + URXD0);
530 
531 		temp = readl(sport->port.membase + USR2);
532 		if (temp & USR2_BRCD) {
533 			writel(USR2_BRCD, sport->port.membase + USR2);
534 			if (uart_handle_break(&sport->port))
535 				continue;
536 		}
537 
538 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
539 			continue;
540 
541 		if (unlikely(rx & URXD_ERR)) {
542 			if (rx & URXD_BRK)
543 				sport->port.icount.brk++;
544 			else if (rx & URXD_PRERR)
545 				sport->port.icount.parity++;
546 			else if (rx & URXD_FRMERR)
547 				sport->port.icount.frame++;
548 			if (rx & URXD_OVRRUN)
549 				sport->port.icount.overrun++;
550 
551 			if (rx & sport->port.ignore_status_mask) {
552 				if (++ignored > 100)
553 					goto out;
554 				continue;
555 			}
556 
557 			rx &= sport->port.read_status_mask;
558 
559 			if (rx & URXD_BRK)
560 				flg = TTY_BREAK;
561 			else if (rx & URXD_PRERR)
562 				flg = TTY_PARITY;
563 			else if (rx & URXD_FRMERR)
564 				flg = TTY_FRAME;
565 			if (rx & URXD_OVRRUN)
566 				flg = TTY_OVERRUN;
567 
568 #ifdef SUPPORT_SYSRQ
569 			sport->port.sysrq = 0;
570 #endif
571 		}
572 
573 		tty_insert_flip_char(tty, rx, flg);
574 	}
575 
576 out:
577 	spin_unlock_irqrestore(&sport->port.lock,flags);
578 	tty_flip_buffer_push(tty);
579 	return IRQ_HANDLED;
580 }
581 
582 static irqreturn_t imx_int(int irq, void *dev_id)
583 {
584 	struct imx_port *sport = dev_id;
585 	unsigned int sts;
586 
587 	sts = readl(sport->port.membase + USR1);
588 
589 	if (sts & USR1_RRDY)
590 		imx_rxint(irq, dev_id);
591 
592 	if (sts & USR1_TRDY &&
593 			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
594 		imx_txint(irq, dev_id);
595 
596 	if (sts & USR1_RTSD)
597 		imx_rtsint(irq, dev_id);
598 
599 	if (sts & USR1_AWAKE)
600 		writel(USR1_AWAKE, sport->port.membase + USR1);
601 
602 	return IRQ_HANDLED;
603 }
604 
605 /*
606  * Return TIOCSER_TEMT when transmitter is not busy.
607  */
608 static unsigned int imx_tx_empty(struct uart_port *port)
609 {
610 	struct imx_port *sport = (struct imx_port *)port;
611 
612 	return (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
613 }
614 
615 /*
616  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
617  */
618 static unsigned int imx_get_mctrl(struct uart_port *port)
619 {
620 	struct imx_port *sport = (struct imx_port *)port;
621 	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
622 
623 	if (readl(sport->port.membase + USR1) & USR1_RTSS)
624 		tmp |= TIOCM_CTS;
625 
626 	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
627 		tmp |= TIOCM_RTS;
628 
629 	return tmp;
630 }
631 
632 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
633 {
634 	struct imx_port *sport = (struct imx_port *)port;
635 	unsigned long temp;
636 
637 	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
638 
639 	if (mctrl & TIOCM_RTS)
640 		temp |= UCR2_CTS;
641 
642 	writel(temp, sport->port.membase + UCR2);
643 }
644 
645 /*
646  * Interrupts always disabled.
647  */
648 static void imx_break_ctl(struct uart_port *port, int break_state)
649 {
650 	struct imx_port *sport = (struct imx_port *)port;
651 	unsigned long flags, temp;
652 
653 	spin_lock_irqsave(&sport->port.lock, flags);
654 
655 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
656 
657 	if ( break_state != 0 )
658 		temp |= UCR1_SNDBRK;
659 
660 	writel(temp, sport->port.membase + UCR1);
661 
662 	spin_unlock_irqrestore(&sport->port.lock, flags);
663 }
664 
665 #define TXTL 2 /* reset default */
666 #define RXTL 1 /* reset default */
667 
668 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
669 {
670 	unsigned int val;
671 	unsigned int ufcr_rfdiv;
672 
673 	/* set receiver / transmitter trigger level.
674 	 * RFDIV is set such way to satisfy requested uartclk value
675 	 */
676 	val = TXTL << 10 | RXTL;
677 	ufcr_rfdiv = (clk_get_rate(sport->clk_per) + sport->port.uartclk / 2)
678 			/ sport->port.uartclk;
679 
680 	if(!ufcr_rfdiv)
681 		ufcr_rfdiv = 1;
682 
683 	val |= UFCR_RFDIV_REG(ufcr_rfdiv);
684 
685 	writel(val, sport->port.membase + UFCR);
686 
687 	return 0;
688 }
689 
690 /* half the RX buffer size */
691 #define CTSTL 16
692 
693 static int imx_startup(struct uart_port *port)
694 {
695 	struct imx_port *sport = (struct imx_port *)port;
696 	int retval;
697 	unsigned long flags, temp;
698 
699 	imx_setup_ufcr(sport, 0);
700 
701 	/* disable the DREN bit (Data Ready interrupt enable) before
702 	 * requesting IRQs
703 	 */
704 	temp = readl(sport->port.membase + UCR4);
705 
706 	if (USE_IRDA(sport))
707 		temp |= UCR4_IRSC;
708 
709 	/* set the trigger level for CTS */
710 	temp &= ~(UCR4_CTSTL_MASK<<  UCR4_CTSTL_SHF);
711 	temp |= CTSTL<<  UCR4_CTSTL_SHF;
712 
713 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
714 
715 	if (USE_IRDA(sport)) {
716 		/* reset fifo's and state machines */
717 		int i = 100;
718 		temp = readl(sport->port.membase + UCR2);
719 		temp &= ~UCR2_SRST;
720 		writel(temp, sport->port.membase + UCR2);
721 		while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
722 		    (--i > 0)) {
723 			udelay(1);
724 		}
725 	}
726 
727 	/*
728 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
729 	 * chips only have one interrupt.
730 	 */
731 	if (sport->txirq > 0) {
732 		retval = request_irq(sport->rxirq, imx_rxint, 0,
733 				DRIVER_NAME, sport);
734 		if (retval)
735 			goto error_out1;
736 
737 		retval = request_irq(sport->txirq, imx_txint, 0,
738 				DRIVER_NAME, sport);
739 		if (retval)
740 			goto error_out2;
741 
742 		/* do not use RTS IRQ on IrDA */
743 		if (!USE_IRDA(sport)) {
744 			retval = request_irq(sport->rtsirq, imx_rtsint,
745 				     (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
746 				       IRQF_TRIGGER_FALLING |
747 				       IRQF_TRIGGER_RISING,
748 					DRIVER_NAME, sport);
749 			if (retval)
750 				goto error_out3;
751 		}
752 	} else {
753 		retval = request_irq(sport->port.irq, imx_int, 0,
754 				DRIVER_NAME, sport);
755 		if (retval) {
756 			free_irq(sport->port.irq, sport);
757 			goto error_out1;
758 		}
759 	}
760 
761 	/*
762 	 * Finally, clear and enable interrupts
763 	 */
764 	writel(USR1_RTSD, sport->port.membase + USR1);
765 
766 	temp = readl(sport->port.membase + UCR1);
767 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
768 
769 	if (USE_IRDA(sport)) {
770 		temp |= UCR1_IREN;
771 		temp &= ~(UCR1_RTSDEN);
772 	}
773 
774 	writel(temp, sport->port.membase + UCR1);
775 
776 	temp = readl(sport->port.membase + UCR2);
777 	temp |= (UCR2_RXEN | UCR2_TXEN);
778 	writel(temp, sport->port.membase + UCR2);
779 
780 	if (USE_IRDA(sport)) {
781 		/* clear RX-FIFO */
782 		int i = 64;
783 		while ((--i > 0) &&
784 			(readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
785 			barrier();
786 		}
787 	}
788 
789 	if (is_imx21_uart(sport)) {
790 		temp = readl(sport->port.membase + UCR3);
791 		temp |= IMX21_UCR3_RXDMUXSEL;
792 		writel(temp, sport->port.membase + UCR3);
793 	}
794 
795 	if (USE_IRDA(sport)) {
796 		temp = readl(sport->port.membase + UCR4);
797 		if (sport->irda_inv_rx)
798 			temp |= UCR4_INVR;
799 		else
800 			temp &= ~(UCR4_INVR);
801 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
802 
803 		temp = readl(sport->port.membase + UCR3);
804 		if (sport->irda_inv_tx)
805 			temp |= UCR3_INVT;
806 		else
807 			temp &= ~(UCR3_INVT);
808 		writel(temp, sport->port.membase + UCR3);
809 	}
810 
811 	/*
812 	 * Enable modem status interrupts
813 	 */
814 	spin_lock_irqsave(&sport->port.lock,flags);
815 	imx_enable_ms(&sport->port);
816 	spin_unlock_irqrestore(&sport->port.lock,flags);
817 
818 	if (USE_IRDA(sport)) {
819 		struct imxuart_platform_data *pdata;
820 		pdata = sport->port.dev->platform_data;
821 		sport->irda_inv_rx = pdata->irda_inv_rx;
822 		sport->irda_inv_tx = pdata->irda_inv_tx;
823 		sport->trcv_delay = pdata->transceiver_delay;
824 		if (pdata->irda_enable)
825 			pdata->irda_enable(1);
826 	}
827 
828 	return 0;
829 
830 error_out3:
831 	if (sport->txirq)
832 		free_irq(sport->txirq, sport);
833 error_out2:
834 	if (sport->rxirq)
835 		free_irq(sport->rxirq, sport);
836 error_out1:
837 	return retval;
838 }
839 
840 static void imx_shutdown(struct uart_port *port)
841 {
842 	struct imx_port *sport = (struct imx_port *)port;
843 	unsigned long temp;
844 
845 	temp = readl(sport->port.membase + UCR2);
846 	temp &= ~(UCR2_TXEN);
847 	writel(temp, sport->port.membase + UCR2);
848 
849 	if (USE_IRDA(sport)) {
850 		struct imxuart_platform_data *pdata;
851 		pdata = sport->port.dev->platform_data;
852 		if (pdata->irda_enable)
853 			pdata->irda_enable(0);
854 	}
855 
856 	/*
857 	 * Stop our timer.
858 	 */
859 	del_timer_sync(&sport->timer);
860 
861 	/*
862 	 * Free the interrupts
863 	 */
864 	if (sport->txirq > 0) {
865 		if (!USE_IRDA(sport))
866 			free_irq(sport->rtsirq, sport);
867 		free_irq(sport->txirq, sport);
868 		free_irq(sport->rxirq, sport);
869 	} else
870 		free_irq(sport->port.irq, sport);
871 
872 	/*
873 	 * Disable all interrupts, port and break condition.
874 	 */
875 
876 	temp = readl(sport->port.membase + UCR1);
877 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
878 	if (USE_IRDA(sport))
879 		temp &= ~(UCR1_IREN);
880 
881 	writel(temp, sport->port.membase + UCR1);
882 }
883 
884 static void
885 imx_set_termios(struct uart_port *port, struct ktermios *termios,
886 		   struct ktermios *old)
887 {
888 	struct imx_port *sport = (struct imx_port *)port;
889 	unsigned long flags;
890 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
891 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
892 	unsigned int div, ufcr;
893 	unsigned long num, denom;
894 	uint64_t tdiv64;
895 
896 	/*
897 	 * If we don't support modem control lines, don't allow
898 	 * these to be set.
899 	 */
900 	if (0) {
901 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
902 		termios->c_cflag |= CLOCAL;
903 	}
904 
905 	/*
906 	 * We only support CS7 and CS8.
907 	 */
908 	while ((termios->c_cflag & CSIZE) != CS7 &&
909 	       (termios->c_cflag & CSIZE) != CS8) {
910 		termios->c_cflag &= ~CSIZE;
911 		termios->c_cflag |= old_csize;
912 		old_csize = CS8;
913 	}
914 
915 	if ((termios->c_cflag & CSIZE) == CS8)
916 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
917 	else
918 		ucr2 = UCR2_SRST | UCR2_IRTS;
919 
920 	if (termios->c_cflag & CRTSCTS) {
921 		if( sport->have_rtscts ) {
922 			ucr2 &= ~UCR2_IRTS;
923 			ucr2 |= UCR2_CTSC;
924 		} else {
925 			termios->c_cflag &= ~CRTSCTS;
926 		}
927 	}
928 
929 	if (termios->c_cflag & CSTOPB)
930 		ucr2 |= UCR2_STPB;
931 	if (termios->c_cflag & PARENB) {
932 		ucr2 |= UCR2_PREN;
933 		if (termios->c_cflag & PARODD)
934 			ucr2 |= UCR2_PROE;
935 	}
936 
937 	del_timer_sync(&sport->timer);
938 
939 	/*
940 	 * Ask the core to calculate the divisor for us.
941 	 */
942 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
943 	quot = uart_get_divisor(port, baud);
944 
945 	spin_lock_irqsave(&sport->port.lock, flags);
946 
947 	sport->port.read_status_mask = 0;
948 	if (termios->c_iflag & INPCK)
949 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
950 	if (termios->c_iflag & (BRKINT | PARMRK))
951 		sport->port.read_status_mask |= URXD_BRK;
952 
953 	/*
954 	 * Characters to ignore
955 	 */
956 	sport->port.ignore_status_mask = 0;
957 	if (termios->c_iflag & IGNPAR)
958 		sport->port.ignore_status_mask |= URXD_PRERR;
959 	if (termios->c_iflag & IGNBRK) {
960 		sport->port.ignore_status_mask |= URXD_BRK;
961 		/*
962 		 * If we're ignoring parity and break indicators,
963 		 * ignore overruns too (for real raw support).
964 		 */
965 		if (termios->c_iflag & IGNPAR)
966 			sport->port.ignore_status_mask |= URXD_OVRRUN;
967 	}
968 
969 	/*
970 	 * Update the per-port timeout.
971 	 */
972 	uart_update_timeout(port, termios->c_cflag, baud);
973 
974 	/*
975 	 * disable interrupts and drain transmitter
976 	 */
977 	old_ucr1 = readl(sport->port.membase + UCR1);
978 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
979 			sport->port.membase + UCR1);
980 
981 	while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
982 		barrier();
983 
984 	/* then, disable everything */
985 	old_txrxen = readl(sport->port.membase + UCR2);
986 	writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
987 			sport->port.membase + UCR2);
988 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
989 
990 	if (USE_IRDA(sport)) {
991 		/*
992 		 * use maximum available submodule frequency to
993 		 * avoid missing short pulses due to low sampling rate
994 		 */
995 		div = 1;
996 	} else {
997 		div = sport->port.uartclk / (baud * 16);
998 		if (div > 7)
999 			div = 7;
1000 		if (!div)
1001 			div = 1;
1002 	}
1003 
1004 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1005 		1 << 16, 1 << 16, &num, &denom);
1006 
1007 	tdiv64 = sport->port.uartclk;
1008 	tdiv64 *= num;
1009 	do_div(tdiv64, denom * 16 * div);
1010 	tty_termios_encode_baud_rate(termios,
1011 				(speed_t)tdiv64, (speed_t)tdiv64);
1012 
1013 	num -= 1;
1014 	denom -= 1;
1015 
1016 	ufcr = readl(sport->port.membase + UFCR);
1017 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1018 	writel(ufcr, sport->port.membase + UFCR);
1019 
1020 	writel(num, sport->port.membase + UBIR);
1021 	writel(denom, sport->port.membase + UBMR);
1022 
1023 	if (is_imx21_uart(sport))
1024 		writel(sport->port.uartclk / div / 1000,
1025 				sport->port.membase + IMX21_ONEMS);
1026 
1027 	writel(old_ucr1, sport->port.membase + UCR1);
1028 
1029 	/* set the parity, stop bits and data size */
1030 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1031 
1032 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1033 		imx_enable_ms(&sport->port);
1034 
1035 	spin_unlock_irqrestore(&sport->port.lock, flags);
1036 }
1037 
1038 static const char *imx_type(struct uart_port *port)
1039 {
1040 	struct imx_port *sport = (struct imx_port *)port;
1041 
1042 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1043 }
1044 
1045 /*
1046  * Release the memory region(s) being used by 'port'.
1047  */
1048 static void imx_release_port(struct uart_port *port)
1049 {
1050 	struct platform_device *pdev = to_platform_device(port->dev);
1051 	struct resource *mmres;
1052 
1053 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1054 	release_mem_region(mmres->start, resource_size(mmres));
1055 }
1056 
1057 /*
1058  * Request the memory region(s) being used by 'port'.
1059  */
1060 static int imx_request_port(struct uart_port *port)
1061 {
1062 	struct platform_device *pdev = to_platform_device(port->dev);
1063 	struct resource *mmres;
1064 	void *ret;
1065 
1066 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1067 	if (!mmres)
1068 		return -ENODEV;
1069 
1070 	ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
1071 
1072 	return  ret ? 0 : -EBUSY;
1073 }
1074 
1075 /*
1076  * Configure/autoconfigure the port.
1077  */
1078 static void imx_config_port(struct uart_port *port, int flags)
1079 {
1080 	struct imx_port *sport = (struct imx_port *)port;
1081 
1082 	if (flags & UART_CONFIG_TYPE &&
1083 	    imx_request_port(&sport->port) == 0)
1084 		sport->port.type = PORT_IMX;
1085 }
1086 
1087 /*
1088  * Verify the new serial_struct (for TIOCSSERIAL).
1089  * The only change we allow are to the flags and type, and
1090  * even then only between PORT_IMX and PORT_UNKNOWN
1091  */
1092 static int
1093 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1094 {
1095 	struct imx_port *sport = (struct imx_port *)port;
1096 	int ret = 0;
1097 
1098 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1099 		ret = -EINVAL;
1100 	if (sport->port.irq != ser->irq)
1101 		ret = -EINVAL;
1102 	if (ser->io_type != UPIO_MEM)
1103 		ret = -EINVAL;
1104 	if (sport->port.uartclk / 16 != ser->baud_base)
1105 		ret = -EINVAL;
1106 	if ((void *)sport->port.mapbase != ser->iomem_base)
1107 		ret = -EINVAL;
1108 	if (sport->port.iobase != ser->port)
1109 		ret = -EINVAL;
1110 	if (ser->hub6 != 0)
1111 		ret = -EINVAL;
1112 	return ret;
1113 }
1114 
1115 #if defined(CONFIG_CONSOLE_POLL)
1116 static int imx_poll_get_char(struct uart_port *port)
1117 {
1118 	struct imx_port_ucrs old_ucr;
1119 	unsigned int status;
1120 	unsigned char c;
1121 
1122 	/* save control registers */
1123 	imx_port_ucrs_save(port, &old_ucr);
1124 
1125 	/* disable interrupts */
1126 	writel(UCR1_UARTEN, port->membase + UCR1);
1127 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1128 	       port->membase + UCR2);
1129 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1130 	       port->membase + UCR3);
1131 
1132 	/* poll */
1133 	do {
1134 		status = readl(port->membase + USR2);
1135 	} while (~status & USR2_RDR);
1136 
1137 	/* read */
1138 	c = readl(port->membase + URXD0);
1139 
1140 	/* restore control registers */
1141 	imx_port_ucrs_restore(port, &old_ucr);
1142 
1143 	return c;
1144 }
1145 
1146 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1147 {
1148 	struct imx_port_ucrs old_ucr;
1149 	unsigned int status;
1150 
1151 	/* save control registers */
1152 	imx_port_ucrs_save(port, &old_ucr);
1153 
1154 	/* disable interrupts */
1155 	writel(UCR1_UARTEN, port->membase + UCR1);
1156 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1157 	       port->membase + UCR2);
1158 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1159 	       port->membase + UCR3);
1160 
1161 	/* drain */
1162 	do {
1163 		status = readl(port->membase + USR1);
1164 	} while (~status & USR1_TRDY);
1165 
1166 	/* write */
1167 	writel(c, port->membase + URTX0);
1168 
1169 	/* flush */
1170 	do {
1171 		status = readl(port->membase + USR2);
1172 	} while (~status & USR2_TXDC);
1173 
1174 	/* restore control registers */
1175 	imx_port_ucrs_restore(port, &old_ucr);
1176 }
1177 #endif
1178 
1179 static struct uart_ops imx_pops = {
1180 	.tx_empty	= imx_tx_empty,
1181 	.set_mctrl	= imx_set_mctrl,
1182 	.get_mctrl	= imx_get_mctrl,
1183 	.stop_tx	= imx_stop_tx,
1184 	.start_tx	= imx_start_tx,
1185 	.stop_rx	= imx_stop_rx,
1186 	.enable_ms	= imx_enable_ms,
1187 	.break_ctl	= imx_break_ctl,
1188 	.startup	= imx_startup,
1189 	.shutdown	= imx_shutdown,
1190 	.set_termios	= imx_set_termios,
1191 	.type		= imx_type,
1192 	.release_port	= imx_release_port,
1193 	.request_port	= imx_request_port,
1194 	.config_port	= imx_config_port,
1195 	.verify_port	= imx_verify_port,
1196 #if defined(CONFIG_CONSOLE_POLL)
1197 	.poll_get_char  = imx_poll_get_char,
1198 	.poll_put_char  = imx_poll_put_char,
1199 #endif
1200 };
1201 
1202 static struct imx_port *imx_ports[UART_NR];
1203 
1204 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1205 static void imx_console_putchar(struct uart_port *port, int ch)
1206 {
1207 	struct imx_port *sport = (struct imx_port *)port;
1208 
1209 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1210 		barrier();
1211 
1212 	writel(ch, sport->port.membase + URTX0);
1213 }
1214 
1215 /*
1216  * Interrupts are disabled on entering
1217  */
1218 static void
1219 imx_console_write(struct console *co, const char *s, unsigned int count)
1220 {
1221 	struct imx_port *sport = imx_ports[co->index];
1222 	struct imx_port_ucrs old_ucr;
1223 	unsigned int ucr1;
1224 
1225 	/*
1226 	 *	First, save UCR1/2/3 and then disable interrupts
1227 	 */
1228 	imx_port_ucrs_save(&sport->port, &old_ucr);
1229 	ucr1 = old_ucr.ucr1;
1230 
1231 	if (is_imx1_uart(sport))
1232 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1233 	ucr1 |= UCR1_UARTEN;
1234 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1235 
1236 	writel(ucr1, sport->port.membase + UCR1);
1237 
1238 	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1239 
1240 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1241 
1242 	/*
1243 	 *	Finally, wait for transmitter to become empty
1244 	 *	and restore UCR1/2/3
1245 	 */
1246 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1247 
1248 	imx_port_ucrs_restore(&sport->port, &old_ucr);
1249 }
1250 
1251 /*
1252  * If the port was already initialised (eg, by a boot loader),
1253  * try to determine the current setup.
1254  */
1255 static void __init
1256 imx_console_get_options(struct imx_port *sport, int *baud,
1257 			   int *parity, int *bits)
1258 {
1259 
1260 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1261 		/* ok, the port was enabled */
1262 		unsigned int ucr2, ubir,ubmr, uartclk;
1263 		unsigned int baud_raw;
1264 		unsigned int ucfr_rfdiv;
1265 
1266 		ucr2 = readl(sport->port.membase + UCR2);
1267 
1268 		*parity = 'n';
1269 		if (ucr2 & UCR2_PREN) {
1270 			if (ucr2 & UCR2_PROE)
1271 				*parity = 'o';
1272 			else
1273 				*parity = 'e';
1274 		}
1275 
1276 		if (ucr2 & UCR2_WS)
1277 			*bits = 8;
1278 		else
1279 			*bits = 7;
1280 
1281 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1282 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1283 
1284 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1285 		if (ucfr_rfdiv == 6)
1286 			ucfr_rfdiv = 7;
1287 		else
1288 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1289 
1290 		uartclk = clk_get_rate(sport->clk_per);
1291 		uartclk /= ucfr_rfdiv;
1292 
1293 		{	/*
1294 			 * The next code provides exact computation of
1295 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1296 			 * without need of float support or long long division,
1297 			 * which would be required to prevent 32bit arithmetic overflow
1298 			 */
1299 			unsigned int mul = ubir + 1;
1300 			unsigned int div = 16 * (ubmr + 1);
1301 			unsigned int rem = uartclk % div;
1302 
1303 			baud_raw = (uartclk / div) * mul;
1304 			baud_raw += (rem * mul + div / 2) / div;
1305 			*baud = (baud_raw + 50) / 100 * 100;
1306 		}
1307 
1308 		if(*baud != baud_raw)
1309 			printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
1310 				baud_raw, *baud);
1311 	}
1312 }
1313 
1314 static int __init
1315 imx_console_setup(struct console *co, char *options)
1316 {
1317 	struct imx_port *sport;
1318 	int baud = 9600;
1319 	int bits = 8;
1320 	int parity = 'n';
1321 	int flow = 'n';
1322 
1323 	/*
1324 	 * Check whether an invalid uart number has been specified, and
1325 	 * if so, search for the first available port that does have
1326 	 * console support.
1327 	 */
1328 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1329 		co->index = 0;
1330 	sport = imx_ports[co->index];
1331 	if(sport == NULL)
1332 		return -ENODEV;
1333 
1334 	if (options)
1335 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1336 	else
1337 		imx_console_get_options(sport, &baud, &parity, &bits);
1338 
1339 	imx_setup_ufcr(sport, 0);
1340 
1341 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
1342 }
1343 
1344 static struct uart_driver imx_reg;
1345 static struct console imx_console = {
1346 	.name		= DEV_NAME,
1347 	.write		= imx_console_write,
1348 	.device		= uart_console_device,
1349 	.setup		= imx_console_setup,
1350 	.flags		= CON_PRINTBUFFER,
1351 	.index		= -1,
1352 	.data		= &imx_reg,
1353 };
1354 
1355 #define IMX_CONSOLE	&imx_console
1356 #else
1357 #define IMX_CONSOLE	NULL
1358 #endif
1359 
1360 static struct uart_driver imx_reg = {
1361 	.owner          = THIS_MODULE,
1362 	.driver_name    = DRIVER_NAME,
1363 	.dev_name       = DEV_NAME,
1364 	.major          = SERIAL_IMX_MAJOR,
1365 	.minor          = MINOR_START,
1366 	.nr             = ARRAY_SIZE(imx_ports),
1367 	.cons           = IMX_CONSOLE,
1368 };
1369 
1370 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1371 {
1372 	struct imx_port *sport = platform_get_drvdata(dev);
1373 	unsigned int val;
1374 
1375 	/* enable wakeup from i.MX UART */
1376 	val = readl(sport->port.membase + UCR3);
1377 	val |= UCR3_AWAKEN;
1378 	writel(val, sport->port.membase + UCR3);
1379 
1380 	if (sport)
1381 		uart_suspend_port(&imx_reg, &sport->port);
1382 
1383 	return 0;
1384 }
1385 
1386 static int serial_imx_resume(struct platform_device *dev)
1387 {
1388 	struct imx_port *sport = platform_get_drvdata(dev);
1389 	unsigned int val;
1390 
1391 	/* disable wakeup from i.MX UART */
1392 	val = readl(sport->port.membase + UCR3);
1393 	val &= ~UCR3_AWAKEN;
1394 	writel(val, sport->port.membase + UCR3);
1395 
1396 	if (sport)
1397 		uart_resume_port(&imx_reg, &sport->port);
1398 
1399 	return 0;
1400 }
1401 
1402 #ifdef CONFIG_OF
1403 /*
1404  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1405  * could successfully get all information from dt or a negative errno.
1406  */
1407 static int serial_imx_probe_dt(struct imx_port *sport,
1408 		struct platform_device *pdev)
1409 {
1410 	struct device_node *np = pdev->dev.of_node;
1411 	const struct of_device_id *of_id =
1412 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1413 	int ret;
1414 
1415 	if (!np)
1416 		/* no device tree device */
1417 		return 1;
1418 
1419 	ret = of_alias_get_id(np, "serial");
1420 	if (ret < 0) {
1421 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1422 		return ret;
1423 	}
1424 	sport->port.line = ret;
1425 
1426 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1427 		sport->have_rtscts = 1;
1428 
1429 	if (of_get_property(np, "fsl,irda-mode", NULL))
1430 		sport->use_irda = 1;
1431 
1432 	sport->devdata = of_id->data;
1433 
1434 	return 0;
1435 }
1436 #else
1437 static inline int serial_imx_probe_dt(struct imx_port *sport,
1438 		struct platform_device *pdev)
1439 {
1440 	return 1;
1441 }
1442 #endif
1443 
1444 static void serial_imx_probe_pdata(struct imx_port *sport,
1445 		struct platform_device *pdev)
1446 {
1447 	struct imxuart_platform_data *pdata = pdev->dev.platform_data;
1448 
1449 	sport->port.line = pdev->id;
1450 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1451 
1452 	if (!pdata)
1453 		return;
1454 
1455 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1456 		sport->have_rtscts = 1;
1457 
1458 	if (pdata->flags & IMXUART_IRDA)
1459 		sport->use_irda = 1;
1460 }
1461 
1462 static int serial_imx_probe(struct platform_device *pdev)
1463 {
1464 	struct imx_port *sport;
1465 	struct imxuart_platform_data *pdata;
1466 	void __iomem *base;
1467 	int ret = 0;
1468 	struct resource *res;
1469 	struct pinctrl *pinctrl;
1470 
1471 	sport = kzalloc(sizeof(*sport), GFP_KERNEL);
1472 	if (!sport)
1473 		return -ENOMEM;
1474 
1475 	ret = serial_imx_probe_dt(sport, pdev);
1476 	if (ret > 0)
1477 		serial_imx_probe_pdata(sport, pdev);
1478 	else if (ret < 0)
1479 		goto free;
1480 
1481 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1482 	if (!res) {
1483 		ret = -ENODEV;
1484 		goto free;
1485 	}
1486 
1487 	base = ioremap(res->start, PAGE_SIZE);
1488 	if (!base) {
1489 		ret = -ENOMEM;
1490 		goto free;
1491 	}
1492 
1493 	sport->port.dev = &pdev->dev;
1494 	sport->port.mapbase = res->start;
1495 	sport->port.membase = base;
1496 	sport->port.type = PORT_IMX,
1497 	sport->port.iotype = UPIO_MEM;
1498 	sport->port.irq = platform_get_irq(pdev, 0);
1499 	sport->rxirq = platform_get_irq(pdev, 0);
1500 	sport->txirq = platform_get_irq(pdev, 1);
1501 	sport->rtsirq = platform_get_irq(pdev, 2);
1502 	sport->port.fifosize = 32;
1503 	sport->port.ops = &imx_pops;
1504 	sport->port.flags = UPF_BOOT_AUTOCONF;
1505 	init_timer(&sport->timer);
1506 	sport->timer.function = imx_timeout;
1507 	sport->timer.data     = (unsigned long)sport;
1508 
1509 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
1510 	if (IS_ERR(pinctrl)) {
1511 		ret = PTR_ERR(pinctrl);
1512 		goto unmap;
1513 	}
1514 
1515 	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1516 	if (IS_ERR(sport->clk_ipg)) {
1517 		ret = PTR_ERR(sport->clk_ipg);
1518 		goto unmap;
1519 	}
1520 
1521 	sport->clk_per = devm_clk_get(&pdev->dev, "per");
1522 	if (IS_ERR(sport->clk_per)) {
1523 		ret = PTR_ERR(sport->clk_per);
1524 		goto unmap;
1525 	}
1526 
1527 	clk_prepare_enable(sport->clk_per);
1528 	clk_prepare_enable(sport->clk_ipg);
1529 
1530 	sport->port.uartclk = clk_get_rate(sport->clk_per);
1531 
1532 	imx_ports[sport->port.line] = sport;
1533 
1534 	pdata = pdev->dev.platform_data;
1535 	if (pdata && pdata->init) {
1536 		ret = pdata->init(pdev);
1537 		if (ret)
1538 			goto clkput;
1539 	}
1540 
1541 	ret = uart_add_one_port(&imx_reg, &sport->port);
1542 	if (ret)
1543 		goto deinit;
1544 	platform_set_drvdata(pdev, &sport->port);
1545 
1546 	return 0;
1547 deinit:
1548 	if (pdata && pdata->exit)
1549 		pdata->exit(pdev);
1550 clkput:
1551 	clk_disable_unprepare(sport->clk_per);
1552 	clk_disable_unprepare(sport->clk_ipg);
1553 unmap:
1554 	iounmap(sport->port.membase);
1555 free:
1556 	kfree(sport);
1557 
1558 	return ret;
1559 }
1560 
1561 static int serial_imx_remove(struct platform_device *pdev)
1562 {
1563 	struct imxuart_platform_data *pdata;
1564 	struct imx_port *sport = platform_get_drvdata(pdev);
1565 
1566 	pdata = pdev->dev.platform_data;
1567 
1568 	platform_set_drvdata(pdev, NULL);
1569 
1570 	uart_remove_one_port(&imx_reg, &sport->port);
1571 
1572 	clk_disable_unprepare(sport->clk_per);
1573 	clk_disable_unprepare(sport->clk_ipg);
1574 
1575 	if (pdata && pdata->exit)
1576 		pdata->exit(pdev);
1577 
1578 	iounmap(sport->port.membase);
1579 	kfree(sport);
1580 
1581 	return 0;
1582 }
1583 
1584 static struct platform_driver serial_imx_driver = {
1585 	.probe		= serial_imx_probe,
1586 	.remove		= serial_imx_remove,
1587 
1588 	.suspend	= serial_imx_suspend,
1589 	.resume		= serial_imx_resume,
1590 	.id_table	= imx_uart_devtype,
1591 	.driver		= {
1592 		.name	= "imx-uart",
1593 		.owner	= THIS_MODULE,
1594 		.of_match_table = imx_uart_dt_ids,
1595 	},
1596 };
1597 
1598 static int __init imx_serial_init(void)
1599 {
1600 	int ret;
1601 
1602 	printk(KERN_INFO "Serial: IMX driver\n");
1603 
1604 	ret = uart_register_driver(&imx_reg);
1605 	if (ret)
1606 		return ret;
1607 
1608 	ret = platform_driver_register(&serial_imx_driver);
1609 	if (ret != 0)
1610 		uart_unregister_driver(&imx_reg);
1611 
1612 	return ret;
1613 }
1614 
1615 static void __exit imx_serial_exit(void)
1616 {
1617 	platform_driver_unregister(&serial_imx_driver);
1618 	uart_unregister_driver(&imx_reg);
1619 }
1620 
1621 module_init(imx_serial_init);
1622 module_exit(imx_serial_exit);
1623 
1624 MODULE_AUTHOR("Sascha Hauer");
1625 MODULE_DESCRIPTION("IMX generic serial port driver");
1626 MODULE_LICENSE("GPL");
1627 MODULE_ALIAS("platform:imx-uart");
1628