xref: /linux/drivers/tty/serial/imx.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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/io.h>
51 #include <linux/dma-mapping.h>
52 
53 #include <asm/irq.h>
54 #include <linux/platform_data/serial-imx.h>
55 #include <linux/platform_data/dma-imx.h>
56 
57 /* Register definitions */
58 #define URXD0 0x0  /* Receiver Register */
59 #define URTX0 0x40 /* Transmitter Register */
60 #define UCR1  0x80 /* Control Register 1 */
61 #define UCR2  0x84 /* Control Register 2 */
62 #define UCR3  0x88 /* Control Register 3 */
63 #define UCR4  0x8c /* Control Register 4 */
64 #define UFCR  0x90 /* FIFO Control Register */
65 #define USR1  0x94 /* Status Register 1 */
66 #define USR2  0x98 /* Status Register 2 */
67 #define UESC  0x9c /* Escape Character Register */
68 #define UTIM  0xa0 /* Escape Timer Register */
69 #define UBIR  0xa4 /* BRM Incremental Register */
70 #define UBMR  0xa8 /* BRM Modulator Register */
71 #define UBRC  0xac /* Baud Rate Count Register */
72 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
73 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
74 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
75 
76 /* UART Control Register Bit Fields.*/
77 #define URXD_CHARRDY	(1<<15)
78 #define URXD_ERR	(1<<14)
79 #define URXD_OVRRUN	(1<<13)
80 #define URXD_FRMERR	(1<<12)
81 #define URXD_BRK	(1<<11)
82 #define URXD_PRERR	(1<<10)
83 #define UCR1_ADEN	(1<<15) /* Auto detect interrupt */
84 #define UCR1_ADBR	(1<<14) /* Auto detect baud rate */
85 #define UCR1_TRDYEN	(1<<13) /* Transmitter ready interrupt enable */
86 #define UCR1_IDEN	(1<<12) /* Idle condition interrupt */
87 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
88 #define UCR1_RRDYEN	(1<<9)	/* Recv ready interrupt enable */
89 #define UCR1_RDMAEN	(1<<8)	/* Recv ready DMA enable */
90 #define UCR1_IREN	(1<<7)	/* Infrared interface enable */
91 #define UCR1_TXMPTYEN	(1<<6)	/* Transimitter empty interrupt enable */
92 #define UCR1_RTSDEN	(1<<5)	/* RTS delta interrupt enable */
93 #define UCR1_SNDBRK	(1<<4)	/* Send break */
94 #define UCR1_TDMAEN	(1<<3)	/* Transmitter ready DMA enable */
95 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
96 #define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
97 #define UCR1_DOZE	(1<<1)	/* Doze */
98 #define UCR1_UARTEN	(1<<0)	/* UART enabled */
99 #define UCR2_ESCI	(1<<15)	/* Escape seq interrupt enable */
100 #define UCR2_IRTS	(1<<14)	/* Ignore RTS pin */
101 #define UCR2_CTSC	(1<<13)	/* CTS pin control */
102 #define UCR2_CTS	(1<<12)	/* Clear to send */
103 #define UCR2_ESCEN	(1<<11)	/* Escape enable */
104 #define UCR2_PREN	(1<<8)	/* Parity enable */
105 #define UCR2_PROE	(1<<7)	/* Parity odd/even */
106 #define UCR2_STPB	(1<<6)	/* Stop */
107 #define UCR2_WS		(1<<5)	/* Word size */
108 #define UCR2_RTSEN	(1<<4)	/* Request to send interrupt enable */
109 #define UCR2_ATEN	(1<<3)	/* Aging Timer Enable */
110 #define UCR2_TXEN	(1<<2)	/* Transmitter enabled */
111 #define UCR2_RXEN	(1<<1)	/* Receiver enabled */
112 #define UCR2_SRST	(1<<0)	/* SW reset */
113 #define UCR3_DTREN	(1<<13) /* DTR interrupt enable */
114 #define UCR3_PARERREN	(1<<12) /* Parity enable */
115 #define UCR3_FRAERREN	(1<<11) /* Frame error interrupt enable */
116 #define UCR3_DSR	(1<<10) /* Data set ready */
117 #define UCR3_DCD	(1<<9)	/* Data carrier detect */
118 #define UCR3_RI		(1<<8)	/* Ring indicator */
119 #define UCR3_TIMEOUTEN	(1<<7)	/* Timeout interrupt enable */
120 #define UCR3_RXDSEN	(1<<6)	/* Receive status interrupt enable */
121 #define UCR3_AIRINTEN	(1<<5)	/* Async IR wake interrupt enable */
122 #define UCR3_AWAKEN	(1<<4)	/* Async wake interrupt enable */
123 #define IMX21_UCR3_RXDMUXSEL	(1<<2)	/* RXD Muxed Input Select */
124 #define UCR3_INVT	(1<<1)	/* Inverted Infrared transmission */
125 #define UCR3_BPEN	(1<<0)	/* Preset registers enable */
126 #define UCR4_CTSTL_SHF	10	/* CTS trigger level shift */
127 #define UCR4_CTSTL_MASK	0x3F	/* CTS trigger is 6 bits wide */
128 #define UCR4_INVR	(1<<9)	/* Inverted infrared reception */
129 #define UCR4_ENIRI	(1<<8)	/* Serial infrared interrupt enable */
130 #define UCR4_WKEN	(1<<7)	/* Wake interrupt enable */
131 #define UCR4_REF16	(1<<6)	/* Ref freq 16 MHz */
132 #define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
133 #define UCR4_IRSC	(1<<5)	/* IR special case */
134 #define UCR4_TCEN	(1<<3)	/* Transmit complete interrupt enable */
135 #define UCR4_BKEN	(1<<2)	/* Break condition interrupt enable */
136 #define UCR4_OREN	(1<<1)	/* Receiver overrun interrupt enable */
137 #define UCR4_DREN	(1<<0)	/* Recv data ready interrupt enable */
138 #define UFCR_RXTL_SHF	0	/* Receiver trigger level shift */
139 #define UFCR_DCEDTE	(1<<6)	/* DCE/DTE mode select */
140 #define UFCR_RFDIV	(7<<7)	/* Reference freq divider mask */
141 #define UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
142 #define UFCR_TXTL_SHF	10	/* Transmitter trigger level shift */
143 #define USR1_PARITYERR	(1<<15) /* Parity error interrupt flag */
144 #define USR1_RTSS	(1<<14) /* RTS pin status */
145 #define USR1_TRDY	(1<<13) /* Transmitter ready interrupt/dma flag */
146 #define USR1_RTSD	(1<<12) /* RTS delta */
147 #define USR1_ESCF	(1<<11) /* Escape seq interrupt flag */
148 #define USR1_FRAMERR	(1<<10) /* Frame error interrupt flag */
149 #define USR1_RRDY	(1<<9)	 /* Receiver ready interrupt/dma flag */
150 #define USR1_TIMEOUT	(1<<7)	 /* Receive timeout interrupt status */
151 #define USR1_RXDS	 (1<<6)	 /* Receiver idle interrupt flag */
152 #define USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
153 #define USR1_AWAKE	 (1<<4)	 /* Aysnc wake interrupt flag */
154 #define USR2_ADET	 (1<<15) /* Auto baud rate detect complete */
155 #define USR2_TXFE	 (1<<14) /* Transmit buffer FIFO empty */
156 #define USR2_DTRF	 (1<<13) /* DTR edge interrupt flag */
157 #define USR2_IDLE	 (1<<12) /* Idle condition */
158 #define USR2_IRINT	 (1<<8)	 /* Serial infrared interrupt flag */
159 #define USR2_WAKE	 (1<<7)	 /* Wake */
160 #define USR2_RTSF	 (1<<4)	 /* RTS edge interrupt flag */
161 #define USR2_TXDC	 (1<<3)	 /* Transmitter complete */
162 #define USR2_BRCD	 (1<<2)	 /* Break condition */
163 #define USR2_ORE	(1<<1)	 /* Overrun error */
164 #define USR2_RDR	(1<<0)	 /* Recv data ready */
165 #define UTS_FRCPERR	(1<<13) /* Force parity error */
166 #define UTS_LOOP	(1<<12)	 /* Loop tx and rx */
167 #define UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
168 #define UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
169 #define UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
170 #define UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
171 #define UTS_SOFTRST	 (1<<0)	 /* Software reset */
172 
173 /* We've been assigned a range on the "Low-density serial ports" major */
174 #define SERIAL_IMX_MAJOR	207
175 #define MINOR_START		16
176 #define DEV_NAME		"ttymxc"
177 
178 /*
179  * This determines how often we check the modem status signals
180  * for any change.  They generally aren't connected to an IRQ
181  * so we have to poll them.  We also check immediately before
182  * filling the TX fifo incase CTS has been dropped.
183  */
184 #define MCTRL_TIMEOUT	(250*HZ/1000)
185 
186 #define DRIVER_NAME "IMX-uart"
187 
188 #define UART_NR 8
189 
190 /* i.mx21 type uart runs on all i.mx except i.mx1 */
191 enum imx_uart_type {
192 	IMX1_UART,
193 	IMX21_UART,
194 	IMX6Q_UART,
195 };
196 
197 /* device type dependent stuff */
198 struct imx_uart_data {
199 	unsigned uts_reg;
200 	enum imx_uart_type devtype;
201 };
202 
203 struct imx_port {
204 	struct uart_port	port;
205 	struct timer_list	timer;
206 	unsigned int		old_status;
207 	int			txirq, rxirq, rtsirq;
208 	unsigned int		have_rtscts:1;
209 	unsigned int		dte_mode:1;
210 	unsigned int		use_irda:1;
211 	unsigned int		irda_inv_rx:1;
212 	unsigned int		irda_inv_tx:1;
213 	unsigned short		trcv_delay; /* transceiver delay */
214 	struct clk		*clk_ipg;
215 	struct clk		*clk_per;
216 	const struct imx_uart_data *devdata;
217 
218 	/* DMA fields */
219 	unsigned int		dma_is_inited:1;
220 	unsigned int		dma_is_enabled:1;
221 	unsigned int		dma_is_rxing:1;
222 	unsigned int		dma_is_txing:1;
223 	struct dma_chan		*dma_chan_rx, *dma_chan_tx;
224 	struct scatterlist	rx_sgl, tx_sgl[2];
225 	void			*rx_buf;
226 	unsigned int		tx_bytes;
227 	unsigned int		dma_tx_nents;
228 	wait_queue_head_t	dma_wait;
229 };
230 
231 struct imx_port_ucrs {
232 	unsigned int	ucr1;
233 	unsigned int	ucr2;
234 	unsigned int	ucr3;
235 };
236 
237 #ifdef CONFIG_IRDA
238 #define USE_IRDA(sport)	((sport)->use_irda)
239 #else
240 #define USE_IRDA(sport)	(0)
241 #endif
242 
243 static struct imx_uart_data imx_uart_devdata[] = {
244 	[IMX1_UART] = {
245 		.uts_reg = IMX1_UTS,
246 		.devtype = IMX1_UART,
247 	},
248 	[IMX21_UART] = {
249 		.uts_reg = IMX21_UTS,
250 		.devtype = IMX21_UART,
251 	},
252 	[IMX6Q_UART] = {
253 		.uts_reg = IMX21_UTS,
254 		.devtype = IMX6Q_UART,
255 	},
256 };
257 
258 static struct platform_device_id imx_uart_devtype[] = {
259 	{
260 		.name = "imx1-uart",
261 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
262 	}, {
263 		.name = "imx21-uart",
264 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
265 	}, {
266 		.name = "imx6q-uart",
267 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
268 	}, {
269 		/* sentinel */
270 	}
271 };
272 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
273 
274 static struct of_device_id imx_uart_dt_ids[] = {
275 	{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
276 	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
277 	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
278 	{ /* sentinel */ }
279 };
280 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
281 
282 static inline unsigned uts_reg(struct imx_port *sport)
283 {
284 	return sport->devdata->uts_reg;
285 }
286 
287 static inline int is_imx1_uart(struct imx_port *sport)
288 {
289 	return sport->devdata->devtype == IMX1_UART;
290 }
291 
292 static inline int is_imx21_uart(struct imx_port *sport)
293 {
294 	return sport->devdata->devtype == IMX21_UART;
295 }
296 
297 static inline int is_imx6q_uart(struct imx_port *sport)
298 {
299 	return sport->devdata->devtype == IMX6Q_UART;
300 }
301 /*
302  * Save and restore functions for UCR1, UCR2 and UCR3 registers
303  */
304 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
305 static void imx_port_ucrs_save(struct uart_port *port,
306 			       struct imx_port_ucrs *ucr)
307 {
308 	/* save control registers */
309 	ucr->ucr1 = readl(port->membase + UCR1);
310 	ucr->ucr2 = readl(port->membase + UCR2);
311 	ucr->ucr3 = readl(port->membase + UCR3);
312 }
313 
314 static void imx_port_ucrs_restore(struct uart_port *port,
315 				  struct imx_port_ucrs *ucr)
316 {
317 	/* restore control registers */
318 	writel(ucr->ucr1, port->membase + UCR1);
319 	writel(ucr->ucr2, port->membase + UCR2);
320 	writel(ucr->ucr3, port->membase + UCR3);
321 }
322 #endif
323 
324 /*
325  * Handle any change of modem status signal since we were last called.
326  */
327 static void imx_mctrl_check(struct imx_port *sport)
328 {
329 	unsigned int status, changed;
330 
331 	status = sport->port.ops->get_mctrl(&sport->port);
332 	changed = status ^ sport->old_status;
333 
334 	if (changed == 0)
335 		return;
336 
337 	sport->old_status = status;
338 
339 	if (changed & TIOCM_RI)
340 		sport->port.icount.rng++;
341 	if (changed & TIOCM_DSR)
342 		sport->port.icount.dsr++;
343 	if (changed & TIOCM_CAR)
344 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
345 	if (changed & TIOCM_CTS)
346 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
347 
348 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
349 }
350 
351 /*
352  * This is our per-port timeout handler, for checking the
353  * modem status signals.
354  */
355 static void imx_timeout(unsigned long data)
356 {
357 	struct imx_port *sport = (struct imx_port *)data;
358 	unsigned long flags;
359 
360 	if (sport->port.state) {
361 		spin_lock_irqsave(&sport->port.lock, flags);
362 		imx_mctrl_check(sport);
363 		spin_unlock_irqrestore(&sport->port.lock, flags);
364 
365 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
366 	}
367 }
368 
369 /*
370  * interrupts disabled on entry
371  */
372 static void imx_stop_tx(struct uart_port *port)
373 {
374 	struct imx_port *sport = (struct imx_port *)port;
375 	unsigned long temp;
376 
377 	if (USE_IRDA(sport)) {
378 		/* half duplex - wait for end of transmission */
379 		int n = 256;
380 		while ((--n > 0) &&
381 		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
382 			udelay(5);
383 			barrier();
384 		}
385 		/*
386 		 * irda transceiver - wait a bit more to avoid
387 		 * cutoff, hardware dependent
388 		 */
389 		udelay(sport->trcv_delay);
390 
391 		/*
392 		 * half duplex - reactivate receive mode,
393 		 * flush receive pipe echo crap
394 		 */
395 		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
396 			temp = readl(sport->port.membase + UCR1);
397 			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
398 			writel(temp, sport->port.membase + UCR1);
399 
400 			temp = readl(sport->port.membase + UCR4);
401 			temp &= ~(UCR4_TCEN);
402 			writel(temp, sport->port.membase + UCR4);
403 
404 			while (readl(sport->port.membase + URXD0) &
405 			       URXD_CHARRDY)
406 				barrier();
407 
408 			temp = readl(sport->port.membase + UCR1);
409 			temp |= UCR1_RRDYEN;
410 			writel(temp, sport->port.membase + UCR1);
411 
412 			temp = readl(sport->port.membase + UCR4);
413 			temp |= UCR4_DREN;
414 			writel(temp, sport->port.membase + UCR4);
415 		}
416 		return;
417 	}
418 
419 	/*
420 	 * We are maybe in the SMP context, so if the DMA TX thread is running
421 	 * on other cpu, we have to wait for it to finish.
422 	 */
423 	if (sport->dma_is_enabled && sport->dma_is_txing)
424 		return;
425 
426 	temp = readl(sport->port.membase + UCR1);
427 	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
428 }
429 
430 /*
431  * interrupts disabled on entry
432  */
433 static void imx_stop_rx(struct uart_port *port)
434 {
435 	struct imx_port *sport = (struct imx_port *)port;
436 	unsigned long temp;
437 
438 	/*
439 	 * We are maybe in the SMP context, so if the DMA TX thread is running
440 	 * on other cpu, we have to wait for it to finish.
441 	 */
442 	if (sport->dma_is_enabled && sport->dma_is_rxing)
443 		return;
444 
445 	temp = readl(sport->port.membase + UCR2);
446 	writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
447 }
448 
449 /*
450  * Set the modem control timer to fire immediately.
451  */
452 static void imx_enable_ms(struct uart_port *port)
453 {
454 	struct imx_port *sport = (struct imx_port *)port;
455 
456 	mod_timer(&sport->timer, jiffies);
457 }
458 
459 static inline void imx_transmit_buffer(struct imx_port *sport)
460 {
461 	struct circ_buf *xmit = &sport->port.state->xmit;
462 
463 	while (!uart_circ_empty(xmit) &&
464 			!(readl(sport->port.membase + uts_reg(sport))
465 				& UTS_TXFULL)) {
466 		/* send xmit->buf[xmit->tail]
467 		 * out the port here */
468 		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
469 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
470 		sport->port.icount.tx++;
471 	}
472 
473 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
474 		uart_write_wakeup(&sport->port);
475 
476 	if (uart_circ_empty(xmit))
477 		imx_stop_tx(&sport->port);
478 }
479 
480 static void dma_tx_callback(void *data)
481 {
482 	struct imx_port *sport = data;
483 	struct scatterlist *sgl = &sport->tx_sgl[0];
484 	struct circ_buf *xmit = &sport->port.state->xmit;
485 	unsigned long flags;
486 
487 	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
488 
489 	sport->dma_is_txing = 0;
490 
491 	/* update the stat */
492 	spin_lock_irqsave(&sport->port.lock, flags);
493 	xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
494 	sport->port.icount.tx += sport->tx_bytes;
495 	spin_unlock_irqrestore(&sport->port.lock, flags);
496 
497 	dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
498 
499 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
500 		uart_write_wakeup(&sport->port);
501 
502 	if (waitqueue_active(&sport->dma_wait)) {
503 		wake_up(&sport->dma_wait);
504 		dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
505 		return;
506 	}
507 }
508 
509 static void imx_dma_tx(struct imx_port *sport)
510 {
511 	struct circ_buf *xmit = &sport->port.state->xmit;
512 	struct scatterlist *sgl = sport->tx_sgl;
513 	struct dma_async_tx_descriptor *desc;
514 	struct dma_chan	*chan = sport->dma_chan_tx;
515 	struct device *dev = sport->port.dev;
516 	enum dma_status status;
517 	int ret;
518 
519 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
520 	if (DMA_IN_PROGRESS == status)
521 		return;
522 
523 	sport->tx_bytes = uart_circ_chars_pending(xmit);
524 
525 	if (xmit->tail > xmit->head && xmit->head > 0) {
526 		sport->dma_tx_nents = 2;
527 		sg_init_table(sgl, 2);
528 		sg_set_buf(sgl, xmit->buf + xmit->tail,
529 				UART_XMIT_SIZE - xmit->tail);
530 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
531 	} else {
532 		sport->dma_tx_nents = 1;
533 		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
534 	}
535 
536 	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
537 	if (ret == 0) {
538 		dev_err(dev, "DMA mapping error for TX.\n");
539 		return;
540 	}
541 	desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
542 					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
543 	if (!desc) {
544 		dev_err(dev, "We cannot prepare for the TX slave dma!\n");
545 		return;
546 	}
547 	desc->callback = dma_tx_callback;
548 	desc->callback_param = sport;
549 
550 	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
551 			uart_circ_chars_pending(xmit));
552 	/* fire it */
553 	sport->dma_is_txing = 1;
554 	dmaengine_submit(desc);
555 	dma_async_issue_pending(chan);
556 	return;
557 }
558 
559 /*
560  * interrupts disabled on entry
561  */
562 static void imx_start_tx(struct uart_port *port)
563 {
564 	struct imx_port *sport = (struct imx_port *)port;
565 	unsigned long temp;
566 
567 	if (USE_IRDA(sport)) {
568 		/* half duplex in IrDA mode; have to disable receive mode */
569 		temp = readl(sport->port.membase + UCR4);
570 		temp &= ~(UCR4_DREN);
571 		writel(temp, sport->port.membase + UCR4);
572 
573 		temp = readl(sport->port.membase + UCR1);
574 		temp &= ~(UCR1_RRDYEN);
575 		writel(temp, sport->port.membase + UCR1);
576 	}
577 	/* Clear any pending ORE flag before enabling interrupt */
578 	temp = readl(sport->port.membase + USR2);
579 	writel(temp | USR2_ORE, sport->port.membase + USR2);
580 
581 	temp = readl(sport->port.membase + UCR4);
582 	temp |= UCR4_OREN;
583 	writel(temp, sport->port.membase + UCR4);
584 
585 	if (!sport->dma_is_enabled) {
586 		temp = readl(sport->port.membase + UCR1);
587 		writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
588 	}
589 
590 	if (USE_IRDA(sport)) {
591 		temp = readl(sport->port.membase + UCR1);
592 		temp |= UCR1_TRDYEN;
593 		writel(temp, sport->port.membase + UCR1);
594 
595 		temp = readl(sport->port.membase + UCR4);
596 		temp |= UCR4_TCEN;
597 		writel(temp, sport->port.membase + UCR4);
598 	}
599 
600 	if (sport->dma_is_enabled) {
601 		imx_dma_tx(sport);
602 		return;
603 	}
604 
605 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
606 		imx_transmit_buffer(sport);
607 }
608 
609 static irqreturn_t imx_rtsint(int irq, void *dev_id)
610 {
611 	struct imx_port *sport = dev_id;
612 	unsigned int val;
613 	unsigned long flags;
614 
615 	spin_lock_irqsave(&sport->port.lock, flags);
616 
617 	writel(USR1_RTSD, sport->port.membase + USR1);
618 	val = readl(sport->port.membase + USR1) & USR1_RTSS;
619 	uart_handle_cts_change(&sport->port, !!val);
620 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
621 
622 	spin_unlock_irqrestore(&sport->port.lock, flags);
623 	return IRQ_HANDLED;
624 }
625 
626 static irqreturn_t imx_txint(int irq, void *dev_id)
627 {
628 	struct imx_port *sport = dev_id;
629 	struct circ_buf *xmit = &sport->port.state->xmit;
630 	unsigned long flags;
631 
632 	spin_lock_irqsave(&sport->port.lock, flags);
633 	if (sport->port.x_char) {
634 		/* Send next char */
635 		writel(sport->port.x_char, sport->port.membase + URTX0);
636 		goto out;
637 	}
638 
639 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
640 		imx_stop_tx(&sport->port);
641 		goto out;
642 	}
643 
644 	imx_transmit_buffer(sport);
645 
646 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
647 		uart_write_wakeup(&sport->port);
648 
649 out:
650 	spin_unlock_irqrestore(&sport->port.lock, flags);
651 	return IRQ_HANDLED;
652 }
653 
654 static irqreturn_t imx_rxint(int irq, void *dev_id)
655 {
656 	struct imx_port *sport = dev_id;
657 	unsigned int rx, flg, ignored = 0;
658 	struct tty_port *port = &sport->port.state->port;
659 	unsigned long flags, temp;
660 
661 	spin_lock_irqsave(&sport->port.lock, flags);
662 
663 	while (readl(sport->port.membase + USR2) & USR2_RDR) {
664 		flg = TTY_NORMAL;
665 		sport->port.icount.rx++;
666 
667 		rx = readl(sport->port.membase + URXD0);
668 
669 		temp = readl(sport->port.membase + USR2);
670 		if (temp & USR2_BRCD) {
671 			writel(USR2_BRCD, sport->port.membase + USR2);
672 			if (uart_handle_break(&sport->port))
673 				continue;
674 		}
675 
676 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
677 			continue;
678 
679 		if (unlikely(rx & URXD_ERR)) {
680 			if (rx & URXD_BRK)
681 				sport->port.icount.brk++;
682 			else if (rx & URXD_PRERR)
683 				sport->port.icount.parity++;
684 			else if (rx & URXD_FRMERR)
685 				sport->port.icount.frame++;
686 			if (rx & URXD_OVRRUN)
687 				sport->port.icount.overrun++;
688 
689 			if (rx & sport->port.ignore_status_mask) {
690 				if (++ignored > 100)
691 					goto out;
692 				continue;
693 			}
694 
695 			rx &= sport->port.read_status_mask;
696 
697 			if (rx & URXD_BRK)
698 				flg = TTY_BREAK;
699 			else if (rx & URXD_PRERR)
700 				flg = TTY_PARITY;
701 			else if (rx & URXD_FRMERR)
702 				flg = TTY_FRAME;
703 			if (rx & URXD_OVRRUN)
704 				flg = TTY_OVERRUN;
705 
706 #ifdef SUPPORT_SYSRQ
707 			sport->port.sysrq = 0;
708 #endif
709 		}
710 
711 		tty_insert_flip_char(port, rx, flg);
712 	}
713 
714 out:
715 	spin_unlock_irqrestore(&sport->port.lock, flags);
716 	tty_flip_buffer_push(port);
717 	return IRQ_HANDLED;
718 }
719 
720 static int start_rx_dma(struct imx_port *sport);
721 /*
722  * If the RXFIFO is filled with some data, and then we
723  * arise a DMA operation to receive them.
724  */
725 static void imx_dma_rxint(struct imx_port *sport)
726 {
727 	unsigned long temp;
728 
729 	temp = readl(sport->port.membase + USR2);
730 	if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
731 		sport->dma_is_rxing = 1;
732 
733 		/* disable the `Recerver Ready Interrrupt` */
734 		temp = readl(sport->port.membase + UCR1);
735 		temp &= ~(UCR1_RRDYEN);
736 		writel(temp, sport->port.membase + UCR1);
737 
738 		/* tell the DMA to receive the data. */
739 		start_rx_dma(sport);
740 	}
741 }
742 
743 static irqreturn_t imx_int(int irq, void *dev_id)
744 {
745 	struct imx_port *sport = dev_id;
746 	unsigned int sts;
747 	unsigned int sts2;
748 
749 	sts = readl(sport->port.membase + USR1);
750 
751 	if (sts & USR1_RRDY) {
752 		if (sport->dma_is_enabled)
753 			imx_dma_rxint(sport);
754 		else
755 			imx_rxint(irq, dev_id);
756 	}
757 
758 	if (sts & USR1_TRDY &&
759 			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
760 		imx_txint(irq, dev_id);
761 
762 	if (sts & USR1_RTSD)
763 		imx_rtsint(irq, dev_id);
764 
765 	if (sts & USR1_AWAKE)
766 		writel(USR1_AWAKE, sport->port.membase + USR1);
767 
768 	sts2 = readl(sport->port.membase + USR2);
769 	if (sts2 & USR2_ORE) {
770 		dev_err(sport->port.dev, "Rx FIFO overrun\n");
771 		sport->port.icount.overrun++;
772 		writel(sts2 | USR2_ORE, sport->port.membase + USR2);
773 	}
774 
775 	return IRQ_HANDLED;
776 }
777 
778 /*
779  * Return TIOCSER_TEMT when transmitter is not busy.
780  */
781 static unsigned int imx_tx_empty(struct uart_port *port)
782 {
783 	struct imx_port *sport = (struct imx_port *)port;
784 	unsigned int ret;
785 
786 	ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
787 
788 	/* If the TX DMA is working, return 0. */
789 	if (sport->dma_is_enabled && sport->dma_is_txing)
790 		ret = 0;
791 
792 	return ret;
793 }
794 
795 /*
796  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
797  */
798 static unsigned int imx_get_mctrl(struct uart_port *port)
799 {
800 	struct imx_port *sport = (struct imx_port *)port;
801 	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
802 
803 	if (readl(sport->port.membase + USR1) & USR1_RTSS)
804 		tmp |= TIOCM_CTS;
805 
806 	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
807 		tmp |= TIOCM_RTS;
808 
809 	return tmp;
810 }
811 
812 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
813 {
814 	struct imx_port *sport = (struct imx_port *)port;
815 	unsigned long temp;
816 
817 	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
818 
819 	if (mctrl & TIOCM_RTS)
820 		if (!sport->dma_is_enabled)
821 			temp |= UCR2_CTS;
822 
823 	writel(temp, sport->port.membase + UCR2);
824 }
825 
826 /*
827  * Interrupts always disabled.
828  */
829 static void imx_break_ctl(struct uart_port *port, int break_state)
830 {
831 	struct imx_port *sport = (struct imx_port *)port;
832 	unsigned long flags, temp;
833 
834 	spin_lock_irqsave(&sport->port.lock, flags);
835 
836 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
837 
838 	if (break_state != 0)
839 		temp |= UCR1_SNDBRK;
840 
841 	writel(temp, sport->port.membase + UCR1);
842 
843 	spin_unlock_irqrestore(&sport->port.lock, flags);
844 }
845 
846 #define TXTL 2 /* reset default */
847 #define RXTL 1 /* reset default */
848 
849 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
850 {
851 	unsigned int val;
852 
853 	/* set receiver / transmitter trigger level */
854 	val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
855 	val |= TXTL << UFCR_TXTL_SHF | RXTL;
856 	writel(val, sport->port.membase + UFCR);
857 	return 0;
858 }
859 
860 #define RX_BUF_SIZE	(PAGE_SIZE)
861 static void imx_rx_dma_done(struct imx_port *sport)
862 {
863 	unsigned long temp;
864 
865 	/* Enable this interrupt when the RXFIFO is empty. */
866 	temp = readl(sport->port.membase + UCR1);
867 	temp |= UCR1_RRDYEN;
868 	writel(temp, sport->port.membase + UCR1);
869 
870 	sport->dma_is_rxing = 0;
871 
872 	/* Is the shutdown waiting for us? */
873 	if (waitqueue_active(&sport->dma_wait))
874 		wake_up(&sport->dma_wait);
875 }
876 
877 /*
878  * There are three kinds of RX DMA interrupts(such as in the MX6Q):
879  *   [1] the RX DMA buffer is full.
880  *   [2] the Aging timer expires(wait for 8 bytes long)
881  *   [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
882  *
883  * The [2] is trigger when a character was been sitting in the FIFO
884  * meanwhile [3] can wait for 32 bytes long when the RX line is
885  * on IDLE state and RxFIFO is empty.
886  */
887 static void dma_rx_callback(void *data)
888 {
889 	struct imx_port *sport = data;
890 	struct dma_chan	*chan = sport->dma_chan_rx;
891 	struct scatterlist *sgl = &sport->rx_sgl;
892 	struct tty_port *port = &sport->port.state->port;
893 	struct dma_tx_state state;
894 	enum dma_status status;
895 	unsigned int count;
896 
897 	/* unmap it first */
898 	dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
899 
900 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
901 	count = RX_BUF_SIZE - state.residue;
902 	dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
903 
904 	if (count) {
905 		tty_insert_flip_string(port, sport->rx_buf, count);
906 		tty_flip_buffer_push(port);
907 
908 		start_rx_dma(sport);
909 	} else
910 		imx_rx_dma_done(sport);
911 }
912 
913 static int start_rx_dma(struct imx_port *sport)
914 {
915 	struct scatterlist *sgl = &sport->rx_sgl;
916 	struct dma_chan	*chan = sport->dma_chan_rx;
917 	struct device *dev = sport->port.dev;
918 	struct dma_async_tx_descriptor *desc;
919 	int ret;
920 
921 	sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
922 	ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
923 	if (ret == 0) {
924 		dev_err(dev, "DMA mapping error for RX.\n");
925 		return -EINVAL;
926 	}
927 	desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
928 					DMA_PREP_INTERRUPT);
929 	if (!desc) {
930 		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
931 		return -EINVAL;
932 	}
933 	desc->callback = dma_rx_callback;
934 	desc->callback_param = sport;
935 
936 	dev_dbg(dev, "RX: prepare for the DMA.\n");
937 	dmaengine_submit(desc);
938 	dma_async_issue_pending(chan);
939 	return 0;
940 }
941 
942 static void imx_uart_dma_exit(struct imx_port *sport)
943 {
944 	if (sport->dma_chan_rx) {
945 		dma_release_channel(sport->dma_chan_rx);
946 		sport->dma_chan_rx = NULL;
947 
948 		kfree(sport->rx_buf);
949 		sport->rx_buf = NULL;
950 	}
951 
952 	if (sport->dma_chan_tx) {
953 		dma_release_channel(sport->dma_chan_tx);
954 		sport->dma_chan_tx = NULL;
955 	}
956 
957 	sport->dma_is_inited = 0;
958 }
959 
960 static int imx_uart_dma_init(struct imx_port *sport)
961 {
962 	struct dma_slave_config slave_config = {};
963 	struct device *dev = sport->port.dev;
964 	int ret;
965 
966 	/* Prepare for RX : */
967 	sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
968 	if (!sport->dma_chan_rx) {
969 		dev_dbg(dev, "cannot get the DMA channel.\n");
970 		ret = -EINVAL;
971 		goto err;
972 	}
973 
974 	slave_config.direction = DMA_DEV_TO_MEM;
975 	slave_config.src_addr = sport->port.mapbase + URXD0;
976 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
977 	slave_config.src_maxburst = RXTL;
978 	ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
979 	if (ret) {
980 		dev_err(dev, "error in RX dma configuration.\n");
981 		goto err;
982 	}
983 
984 	sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
985 	if (!sport->rx_buf) {
986 		dev_err(dev, "cannot alloc DMA buffer.\n");
987 		ret = -ENOMEM;
988 		goto err;
989 	}
990 
991 	/* Prepare for TX : */
992 	sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
993 	if (!sport->dma_chan_tx) {
994 		dev_err(dev, "cannot get the TX DMA channel!\n");
995 		ret = -EINVAL;
996 		goto err;
997 	}
998 
999 	slave_config.direction = DMA_MEM_TO_DEV;
1000 	slave_config.dst_addr = sport->port.mapbase + URTX0;
1001 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1002 	slave_config.dst_maxburst = TXTL;
1003 	ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1004 	if (ret) {
1005 		dev_err(dev, "error in TX dma configuration.");
1006 		goto err;
1007 	}
1008 
1009 	sport->dma_is_inited = 1;
1010 
1011 	return 0;
1012 err:
1013 	imx_uart_dma_exit(sport);
1014 	return ret;
1015 }
1016 
1017 static void imx_enable_dma(struct imx_port *sport)
1018 {
1019 	unsigned long temp;
1020 
1021 	init_waitqueue_head(&sport->dma_wait);
1022 
1023 	/* set UCR1 */
1024 	temp = readl(sport->port.membase + UCR1);
1025 	temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1026 		/* wait for 32 idle frames for IDDMA interrupt */
1027 		UCR1_ICD_REG(3);
1028 	writel(temp, sport->port.membase + UCR1);
1029 
1030 	/* set UCR4 */
1031 	temp = readl(sport->port.membase + UCR4);
1032 	temp |= UCR4_IDDMAEN;
1033 	writel(temp, sport->port.membase + UCR4);
1034 
1035 	sport->dma_is_enabled = 1;
1036 }
1037 
1038 static void imx_disable_dma(struct imx_port *sport)
1039 {
1040 	unsigned long temp;
1041 
1042 	/* clear UCR1 */
1043 	temp = readl(sport->port.membase + UCR1);
1044 	temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1045 	writel(temp, sport->port.membase + UCR1);
1046 
1047 	/* clear UCR2 */
1048 	temp = readl(sport->port.membase + UCR2);
1049 	temp &= ~(UCR2_CTSC | UCR2_CTS);
1050 	writel(temp, sport->port.membase + UCR2);
1051 
1052 	/* clear UCR4 */
1053 	temp = readl(sport->port.membase + UCR4);
1054 	temp &= ~UCR4_IDDMAEN;
1055 	writel(temp, sport->port.membase + UCR4);
1056 
1057 	sport->dma_is_enabled = 0;
1058 }
1059 
1060 /* half the RX buffer size */
1061 #define CTSTL 16
1062 
1063 static int imx_startup(struct uart_port *port)
1064 {
1065 	struct imx_port *sport = (struct imx_port *)port;
1066 	int retval;
1067 	unsigned long flags, temp;
1068 
1069 	retval = clk_prepare_enable(sport->clk_per);
1070 	if (retval)
1071 		goto error_out1;
1072 	retval = clk_prepare_enable(sport->clk_ipg);
1073 	if (retval) {
1074 		clk_disable_unprepare(sport->clk_per);
1075 		goto error_out1;
1076 	}
1077 
1078 	imx_setup_ufcr(sport, 0);
1079 
1080 	/* disable the DREN bit (Data Ready interrupt enable) before
1081 	 * requesting IRQs
1082 	 */
1083 	temp = readl(sport->port.membase + UCR4);
1084 
1085 	if (USE_IRDA(sport))
1086 		temp |= UCR4_IRSC;
1087 
1088 	/* set the trigger level for CTS */
1089 	temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1090 	temp |= CTSTL << UCR4_CTSTL_SHF;
1091 
1092 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1093 
1094 	if (USE_IRDA(sport)) {
1095 		/* reset fifo's and state machines */
1096 		int i = 100;
1097 		temp = readl(sport->port.membase + UCR2);
1098 		temp &= ~UCR2_SRST;
1099 		writel(temp, sport->port.membase + UCR2);
1100 		while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
1101 		    (--i > 0)) {
1102 			udelay(1);
1103 		}
1104 	}
1105 
1106 	/*
1107 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1108 	 * chips only have one interrupt.
1109 	 */
1110 	if (sport->txirq > 0) {
1111 		retval = request_irq(sport->rxirq, imx_rxint, 0,
1112 				DRIVER_NAME, sport);
1113 		if (retval)
1114 			goto error_out1;
1115 
1116 		retval = request_irq(sport->txirq, imx_txint, 0,
1117 				DRIVER_NAME, sport);
1118 		if (retval)
1119 			goto error_out2;
1120 
1121 		/* do not use RTS IRQ on IrDA */
1122 		if (!USE_IRDA(sport)) {
1123 			retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1124 					DRIVER_NAME, sport);
1125 			if (retval)
1126 				goto error_out3;
1127 		}
1128 	} else {
1129 		retval = request_irq(sport->port.irq, imx_int, 0,
1130 				DRIVER_NAME, sport);
1131 		if (retval) {
1132 			free_irq(sport->port.irq, sport);
1133 			goto error_out1;
1134 		}
1135 	}
1136 
1137 	spin_lock_irqsave(&sport->port.lock, flags);
1138 	/*
1139 	 * Finally, clear and enable interrupts
1140 	 */
1141 	writel(USR1_RTSD, sport->port.membase + USR1);
1142 
1143 	temp = readl(sport->port.membase + UCR1);
1144 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1145 
1146 	if (USE_IRDA(sport)) {
1147 		temp |= UCR1_IREN;
1148 		temp &= ~(UCR1_RTSDEN);
1149 	}
1150 
1151 	writel(temp, sport->port.membase + UCR1);
1152 
1153 	temp = readl(sport->port.membase + UCR2);
1154 	temp |= (UCR2_RXEN | UCR2_TXEN);
1155 	if (!sport->have_rtscts)
1156 		temp |= UCR2_IRTS;
1157 	writel(temp, sport->port.membase + UCR2);
1158 
1159 	if (USE_IRDA(sport)) {
1160 		/* clear RX-FIFO */
1161 		int i = 64;
1162 		while ((--i > 0) &&
1163 			(readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
1164 			barrier();
1165 		}
1166 	}
1167 
1168 	if (!is_imx1_uart(sport)) {
1169 		temp = readl(sport->port.membase + UCR3);
1170 		temp |= IMX21_UCR3_RXDMUXSEL;
1171 		writel(temp, sport->port.membase + UCR3);
1172 	}
1173 
1174 	if (USE_IRDA(sport)) {
1175 		temp = readl(sport->port.membase + UCR4);
1176 		if (sport->irda_inv_rx)
1177 			temp |= UCR4_INVR;
1178 		else
1179 			temp &= ~(UCR4_INVR);
1180 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1181 
1182 		temp = readl(sport->port.membase + UCR3);
1183 		if (sport->irda_inv_tx)
1184 			temp |= UCR3_INVT;
1185 		else
1186 			temp &= ~(UCR3_INVT);
1187 		writel(temp, sport->port.membase + UCR3);
1188 	}
1189 
1190 	/*
1191 	 * Enable modem status interrupts
1192 	 */
1193 	imx_enable_ms(&sport->port);
1194 	spin_unlock_irqrestore(&sport->port.lock, flags);
1195 
1196 	if (USE_IRDA(sport)) {
1197 		struct imxuart_platform_data *pdata;
1198 		pdata = dev_get_platdata(sport->port.dev);
1199 		sport->irda_inv_rx = pdata->irda_inv_rx;
1200 		sport->irda_inv_tx = pdata->irda_inv_tx;
1201 		sport->trcv_delay = pdata->transceiver_delay;
1202 		if (pdata->irda_enable)
1203 			pdata->irda_enable(1);
1204 	}
1205 
1206 	return 0;
1207 
1208 error_out3:
1209 	if (sport->txirq)
1210 		free_irq(sport->txirq, sport);
1211 error_out2:
1212 	if (sport->rxirq)
1213 		free_irq(sport->rxirq, sport);
1214 error_out1:
1215 	return retval;
1216 }
1217 
1218 static void imx_shutdown(struct uart_port *port)
1219 {
1220 	struct imx_port *sport = (struct imx_port *)port;
1221 	unsigned long temp;
1222 	unsigned long flags;
1223 
1224 	if (sport->dma_is_enabled) {
1225 		/* We have to wait for the DMA to finish. */
1226 		wait_event(sport->dma_wait,
1227 			!sport->dma_is_rxing && !sport->dma_is_txing);
1228 		imx_stop_rx(port);
1229 		imx_disable_dma(sport);
1230 		imx_uart_dma_exit(sport);
1231 	}
1232 
1233 	spin_lock_irqsave(&sport->port.lock, flags);
1234 	temp = readl(sport->port.membase + UCR2);
1235 	temp &= ~(UCR2_TXEN);
1236 	writel(temp, sport->port.membase + UCR2);
1237 	spin_unlock_irqrestore(&sport->port.lock, flags);
1238 
1239 	if (USE_IRDA(sport)) {
1240 		struct imxuart_platform_data *pdata;
1241 		pdata = dev_get_platdata(sport->port.dev);
1242 		if (pdata->irda_enable)
1243 			pdata->irda_enable(0);
1244 	}
1245 
1246 	/*
1247 	 * Stop our timer.
1248 	 */
1249 	del_timer_sync(&sport->timer);
1250 
1251 	/*
1252 	 * Free the interrupts
1253 	 */
1254 	if (sport->txirq > 0) {
1255 		if (!USE_IRDA(sport))
1256 			free_irq(sport->rtsirq, sport);
1257 		free_irq(sport->txirq, sport);
1258 		free_irq(sport->rxirq, sport);
1259 	} else
1260 		free_irq(sport->port.irq, sport);
1261 
1262 	/*
1263 	 * Disable all interrupts, port and break condition.
1264 	 */
1265 
1266 	spin_lock_irqsave(&sport->port.lock, flags);
1267 	temp = readl(sport->port.membase + UCR1);
1268 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1269 	if (USE_IRDA(sport))
1270 		temp &= ~(UCR1_IREN);
1271 
1272 	writel(temp, sport->port.membase + UCR1);
1273 	spin_unlock_irqrestore(&sport->port.lock, flags);
1274 
1275 	clk_disable_unprepare(sport->clk_per);
1276 	clk_disable_unprepare(sport->clk_ipg);
1277 }
1278 
1279 static void imx_flush_buffer(struct uart_port *port)
1280 {
1281 	struct imx_port *sport = (struct imx_port *)port;
1282 
1283 	if (sport->dma_is_enabled) {
1284 		sport->tx_bytes = 0;
1285 		dmaengine_terminate_all(sport->dma_chan_tx);
1286 	}
1287 }
1288 
1289 static void
1290 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1291 		   struct ktermios *old)
1292 {
1293 	struct imx_port *sport = (struct imx_port *)port;
1294 	unsigned long flags;
1295 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1296 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1297 	unsigned int div, ufcr;
1298 	unsigned long num, denom;
1299 	uint64_t tdiv64;
1300 
1301 	/*
1302 	 * If we don't support modem control lines, don't allow
1303 	 * these to be set.
1304 	 */
1305 	if (0) {
1306 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1307 		termios->c_cflag |= CLOCAL;
1308 	}
1309 
1310 	/*
1311 	 * We only support CS7 and CS8.
1312 	 */
1313 	while ((termios->c_cflag & CSIZE) != CS7 &&
1314 	       (termios->c_cflag & CSIZE) != CS8) {
1315 		termios->c_cflag &= ~CSIZE;
1316 		termios->c_cflag |= old_csize;
1317 		old_csize = CS8;
1318 	}
1319 
1320 	if ((termios->c_cflag & CSIZE) == CS8)
1321 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1322 	else
1323 		ucr2 = UCR2_SRST | UCR2_IRTS;
1324 
1325 	if (termios->c_cflag & CRTSCTS) {
1326 		if (sport->have_rtscts) {
1327 			ucr2 &= ~UCR2_IRTS;
1328 			ucr2 |= UCR2_CTSC;
1329 
1330 			/* Can we enable the DMA support? */
1331 			if (is_imx6q_uart(sport) && !uart_console(port)
1332 				&& !sport->dma_is_inited)
1333 				imx_uart_dma_init(sport);
1334 		} else {
1335 			termios->c_cflag &= ~CRTSCTS;
1336 		}
1337 	}
1338 
1339 	if (termios->c_cflag & CSTOPB)
1340 		ucr2 |= UCR2_STPB;
1341 	if (termios->c_cflag & PARENB) {
1342 		ucr2 |= UCR2_PREN;
1343 		if (termios->c_cflag & PARODD)
1344 			ucr2 |= UCR2_PROE;
1345 	}
1346 
1347 	del_timer_sync(&sport->timer);
1348 
1349 	/*
1350 	 * Ask the core to calculate the divisor for us.
1351 	 */
1352 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1353 	quot = uart_get_divisor(port, baud);
1354 
1355 	spin_lock_irqsave(&sport->port.lock, flags);
1356 
1357 	sport->port.read_status_mask = 0;
1358 	if (termios->c_iflag & INPCK)
1359 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1360 	if (termios->c_iflag & (BRKINT | PARMRK))
1361 		sport->port.read_status_mask |= URXD_BRK;
1362 
1363 	/*
1364 	 * Characters to ignore
1365 	 */
1366 	sport->port.ignore_status_mask = 0;
1367 	if (termios->c_iflag & IGNPAR)
1368 		sport->port.ignore_status_mask |= URXD_PRERR;
1369 	if (termios->c_iflag & IGNBRK) {
1370 		sport->port.ignore_status_mask |= URXD_BRK;
1371 		/*
1372 		 * If we're ignoring parity and break indicators,
1373 		 * ignore overruns too (for real raw support).
1374 		 */
1375 		if (termios->c_iflag & IGNPAR)
1376 			sport->port.ignore_status_mask |= URXD_OVRRUN;
1377 	}
1378 
1379 	/*
1380 	 * Update the per-port timeout.
1381 	 */
1382 	uart_update_timeout(port, termios->c_cflag, baud);
1383 
1384 	/*
1385 	 * disable interrupts and drain transmitter
1386 	 */
1387 	old_ucr1 = readl(sport->port.membase + UCR1);
1388 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1389 			sport->port.membase + UCR1);
1390 
1391 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1392 		barrier();
1393 
1394 	/* then, disable everything */
1395 	old_txrxen = readl(sport->port.membase + UCR2);
1396 	writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1397 			sport->port.membase + UCR2);
1398 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1399 
1400 	if (USE_IRDA(sport)) {
1401 		/*
1402 		 * use maximum available submodule frequency to
1403 		 * avoid missing short pulses due to low sampling rate
1404 		 */
1405 		div = 1;
1406 	} else {
1407 		/* custom-baudrate handling */
1408 		div = sport->port.uartclk / (baud * 16);
1409 		if (baud == 38400 && quot != div)
1410 			baud = sport->port.uartclk / (quot * 16);
1411 
1412 		div = sport->port.uartclk / (baud * 16);
1413 		if (div > 7)
1414 			div = 7;
1415 		if (!div)
1416 			div = 1;
1417 	}
1418 
1419 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1420 		1 << 16, 1 << 16, &num, &denom);
1421 
1422 	tdiv64 = sport->port.uartclk;
1423 	tdiv64 *= num;
1424 	do_div(tdiv64, denom * 16 * div);
1425 	tty_termios_encode_baud_rate(termios,
1426 				(speed_t)tdiv64, (speed_t)tdiv64);
1427 
1428 	num -= 1;
1429 	denom -= 1;
1430 
1431 	ufcr = readl(sport->port.membase + UFCR);
1432 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1433 	if (sport->dte_mode)
1434 		ufcr |= UFCR_DCEDTE;
1435 	writel(ufcr, sport->port.membase + UFCR);
1436 
1437 	writel(num, sport->port.membase + UBIR);
1438 	writel(denom, sport->port.membase + UBMR);
1439 
1440 	if (!is_imx1_uart(sport))
1441 		writel(sport->port.uartclk / div / 1000,
1442 				sport->port.membase + IMX21_ONEMS);
1443 
1444 	writel(old_ucr1, sport->port.membase + UCR1);
1445 
1446 	/* set the parity, stop bits and data size */
1447 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1448 
1449 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1450 		imx_enable_ms(&sport->port);
1451 
1452 	if (sport->dma_is_inited && !sport->dma_is_enabled)
1453 		imx_enable_dma(sport);
1454 	spin_unlock_irqrestore(&sport->port.lock, flags);
1455 }
1456 
1457 static const char *imx_type(struct uart_port *port)
1458 {
1459 	struct imx_port *sport = (struct imx_port *)port;
1460 
1461 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1462 }
1463 
1464 /*
1465  * Release the memory region(s) being used by 'port'.
1466  */
1467 static void imx_release_port(struct uart_port *port)
1468 {
1469 	struct platform_device *pdev = to_platform_device(port->dev);
1470 	struct resource *mmres;
1471 
1472 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1473 	release_mem_region(mmres->start, resource_size(mmres));
1474 }
1475 
1476 /*
1477  * Request the memory region(s) being used by 'port'.
1478  */
1479 static int imx_request_port(struct uart_port *port)
1480 {
1481 	struct platform_device *pdev = to_platform_device(port->dev);
1482 	struct resource *mmres;
1483 	void *ret;
1484 
1485 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1486 	if (!mmres)
1487 		return -ENODEV;
1488 
1489 	ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
1490 
1491 	return  ret ? 0 : -EBUSY;
1492 }
1493 
1494 /*
1495  * Configure/autoconfigure the port.
1496  */
1497 static void imx_config_port(struct uart_port *port, int flags)
1498 {
1499 	struct imx_port *sport = (struct imx_port *)port;
1500 
1501 	if (flags & UART_CONFIG_TYPE &&
1502 	    imx_request_port(&sport->port) == 0)
1503 		sport->port.type = PORT_IMX;
1504 }
1505 
1506 /*
1507  * Verify the new serial_struct (for TIOCSSERIAL).
1508  * The only change we allow are to the flags and type, and
1509  * even then only between PORT_IMX and PORT_UNKNOWN
1510  */
1511 static int
1512 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1513 {
1514 	struct imx_port *sport = (struct imx_port *)port;
1515 	int ret = 0;
1516 
1517 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1518 		ret = -EINVAL;
1519 	if (sport->port.irq != ser->irq)
1520 		ret = -EINVAL;
1521 	if (ser->io_type != UPIO_MEM)
1522 		ret = -EINVAL;
1523 	if (sport->port.uartclk / 16 != ser->baud_base)
1524 		ret = -EINVAL;
1525 	if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1526 		ret = -EINVAL;
1527 	if (sport->port.iobase != ser->port)
1528 		ret = -EINVAL;
1529 	if (ser->hub6 != 0)
1530 		ret = -EINVAL;
1531 	return ret;
1532 }
1533 
1534 #if defined(CONFIG_CONSOLE_POLL)
1535 static int imx_poll_get_char(struct uart_port *port)
1536 {
1537 	struct imx_port_ucrs old_ucr;
1538 	unsigned int status;
1539 	unsigned char c;
1540 
1541 	/* save control registers */
1542 	imx_port_ucrs_save(port, &old_ucr);
1543 
1544 	/* disable interrupts */
1545 	writel(UCR1_UARTEN, port->membase + UCR1);
1546 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1547 	       port->membase + UCR2);
1548 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1549 	       port->membase + UCR3);
1550 
1551 	/* poll */
1552 	do {
1553 		status = readl(port->membase + USR2);
1554 	} while (~status & USR2_RDR);
1555 
1556 	/* read */
1557 	c = readl(port->membase + URXD0);
1558 
1559 	/* restore control registers */
1560 	imx_port_ucrs_restore(port, &old_ucr);
1561 
1562 	return c;
1563 }
1564 
1565 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1566 {
1567 	struct imx_port_ucrs old_ucr;
1568 	unsigned int status;
1569 
1570 	/* save control registers */
1571 	imx_port_ucrs_save(port, &old_ucr);
1572 
1573 	/* disable interrupts */
1574 	writel(UCR1_UARTEN, port->membase + UCR1);
1575 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1576 	       port->membase + UCR2);
1577 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1578 	       port->membase + UCR3);
1579 
1580 	/* drain */
1581 	do {
1582 		status = readl(port->membase + USR1);
1583 	} while (~status & USR1_TRDY);
1584 
1585 	/* write */
1586 	writel(c, port->membase + URTX0);
1587 
1588 	/* flush */
1589 	do {
1590 		status = readl(port->membase + USR2);
1591 	} while (~status & USR2_TXDC);
1592 
1593 	/* restore control registers */
1594 	imx_port_ucrs_restore(port, &old_ucr);
1595 }
1596 #endif
1597 
1598 static struct uart_ops imx_pops = {
1599 	.tx_empty	= imx_tx_empty,
1600 	.set_mctrl	= imx_set_mctrl,
1601 	.get_mctrl	= imx_get_mctrl,
1602 	.stop_tx	= imx_stop_tx,
1603 	.start_tx	= imx_start_tx,
1604 	.stop_rx	= imx_stop_rx,
1605 	.enable_ms	= imx_enable_ms,
1606 	.break_ctl	= imx_break_ctl,
1607 	.startup	= imx_startup,
1608 	.shutdown	= imx_shutdown,
1609 	.flush_buffer	= imx_flush_buffer,
1610 	.set_termios	= imx_set_termios,
1611 	.type		= imx_type,
1612 	.release_port	= imx_release_port,
1613 	.request_port	= imx_request_port,
1614 	.config_port	= imx_config_port,
1615 	.verify_port	= imx_verify_port,
1616 #if defined(CONFIG_CONSOLE_POLL)
1617 	.poll_get_char  = imx_poll_get_char,
1618 	.poll_put_char  = imx_poll_put_char,
1619 #endif
1620 };
1621 
1622 static struct imx_port *imx_ports[UART_NR];
1623 
1624 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1625 static void imx_console_putchar(struct uart_port *port, int ch)
1626 {
1627 	struct imx_port *sport = (struct imx_port *)port;
1628 
1629 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1630 		barrier();
1631 
1632 	writel(ch, sport->port.membase + URTX0);
1633 }
1634 
1635 /*
1636  * Interrupts are disabled on entering
1637  */
1638 static void
1639 imx_console_write(struct console *co, const char *s, unsigned int count)
1640 {
1641 	struct imx_port *sport = imx_ports[co->index];
1642 	struct imx_port_ucrs old_ucr;
1643 	unsigned int ucr1;
1644 	unsigned long flags = 0;
1645 	int locked = 1;
1646 	int retval;
1647 
1648 	retval = clk_enable(sport->clk_per);
1649 	if (retval)
1650 		return;
1651 	retval = clk_enable(sport->clk_ipg);
1652 	if (retval) {
1653 		clk_disable(sport->clk_per);
1654 		return;
1655 	}
1656 
1657 	if (sport->port.sysrq)
1658 		locked = 0;
1659 	else if (oops_in_progress)
1660 		locked = spin_trylock_irqsave(&sport->port.lock, flags);
1661 	else
1662 		spin_lock_irqsave(&sport->port.lock, flags);
1663 
1664 	/*
1665 	 *	First, save UCR1/2/3 and then disable interrupts
1666 	 */
1667 	imx_port_ucrs_save(&sport->port, &old_ucr);
1668 	ucr1 = old_ucr.ucr1;
1669 
1670 	if (is_imx1_uart(sport))
1671 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1672 	ucr1 |= UCR1_UARTEN;
1673 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1674 
1675 	writel(ucr1, sport->port.membase + UCR1);
1676 
1677 	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1678 
1679 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1680 
1681 	/*
1682 	 *	Finally, wait for transmitter to become empty
1683 	 *	and restore UCR1/2/3
1684 	 */
1685 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1686 
1687 	imx_port_ucrs_restore(&sport->port, &old_ucr);
1688 
1689 	if (locked)
1690 		spin_unlock_irqrestore(&sport->port.lock, flags);
1691 
1692 	clk_disable(sport->clk_ipg);
1693 	clk_disable(sport->clk_per);
1694 }
1695 
1696 /*
1697  * If the port was already initialised (eg, by a boot loader),
1698  * try to determine the current setup.
1699  */
1700 static void __init
1701 imx_console_get_options(struct imx_port *sport, int *baud,
1702 			   int *parity, int *bits)
1703 {
1704 
1705 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1706 		/* ok, the port was enabled */
1707 		unsigned int ucr2, ubir, ubmr, uartclk;
1708 		unsigned int baud_raw;
1709 		unsigned int ucfr_rfdiv;
1710 
1711 		ucr2 = readl(sport->port.membase + UCR2);
1712 
1713 		*parity = 'n';
1714 		if (ucr2 & UCR2_PREN) {
1715 			if (ucr2 & UCR2_PROE)
1716 				*parity = 'o';
1717 			else
1718 				*parity = 'e';
1719 		}
1720 
1721 		if (ucr2 & UCR2_WS)
1722 			*bits = 8;
1723 		else
1724 			*bits = 7;
1725 
1726 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1727 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1728 
1729 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1730 		if (ucfr_rfdiv == 6)
1731 			ucfr_rfdiv = 7;
1732 		else
1733 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1734 
1735 		uartclk = clk_get_rate(sport->clk_per);
1736 		uartclk /= ucfr_rfdiv;
1737 
1738 		{	/*
1739 			 * The next code provides exact computation of
1740 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1741 			 * without need of float support or long long division,
1742 			 * which would be required to prevent 32bit arithmetic overflow
1743 			 */
1744 			unsigned int mul = ubir + 1;
1745 			unsigned int div = 16 * (ubmr + 1);
1746 			unsigned int rem = uartclk % div;
1747 
1748 			baud_raw = (uartclk / div) * mul;
1749 			baud_raw += (rem * mul + div / 2) / div;
1750 			*baud = (baud_raw + 50) / 100 * 100;
1751 		}
1752 
1753 		if (*baud != baud_raw)
1754 			pr_info("Console IMX rounded baud rate from %d to %d\n",
1755 				baud_raw, *baud);
1756 	}
1757 }
1758 
1759 static int __init
1760 imx_console_setup(struct console *co, char *options)
1761 {
1762 	struct imx_port *sport;
1763 	int baud = 9600;
1764 	int bits = 8;
1765 	int parity = 'n';
1766 	int flow = 'n';
1767 	int retval;
1768 
1769 	/*
1770 	 * Check whether an invalid uart number has been specified, and
1771 	 * if so, search for the first available port that does have
1772 	 * console support.
1773 	 */
1774 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1775 		co->index = 0;
1776 	sport = imx_ports[co->index];
1777 	if (sport == NULL)
1778 		return -ENODEV;
1779 
1780 	/* For setting the registers, we only need to enable the ipg clock. */
1781 	retval = clk_prepare_enable(sport->clk_ipg);
1782 	if (retval)
1783 		goto error_console;
1784 
1785 	if (options)
1786 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1787 	else
1788 		imx_console_get_options(sport, &baud, &parity, &bits);
1789 
1790 	imx_setup_ufcr(sport, 0);
1791 
1792 	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1793 
1794 	clk_disable(sport->clk_ipg);
1795 	if (retval) {
1796 		clk_unprepare(sport->clk_ipg);
1797 		goto error_console;
1798 	}
1799 
1800 	retval = clk_prepare(sport->clk_per);
1801 	if (retval)
1802 		clk_disable_unprepare(sport->clk_ipg);
1803 
1804 error_console:
1805 	return retval;
1806 }
1807 
1808 static struct uart_driver imx_reg;
1809 static struct console imx_console = {
1810 	.name		= DEV_NAME,
1811 	.write		= imx_console_write,
1812 	.device		= uart_console_device,
1813 	.setup		= imx_console_setup,
1814 	.flags		= CON_PRINTBUFFER,
1815 	.index		= -1,
1816 	.data		= &imx_reg,
1817 };
1818 
1819 #define IMX_CONSOLE	&imx_console
1820 #else
1821 #define IMX_CONSOLE	NULL
1822 #endif
1823 
1824 static struct uart_driver imx_reg = {
1825 	.owner          = THIS_MODULE,
1826 	.driver_name    = DRIVER_NAME,
1827 	.dev_name       = DEV_NAME,
1828 	.major          = SERIAL_IMX_MAJOR,
1829 	.minor          = MINOR_START,
1830 	.nr             = ARRAY_SIZE(imx_ports),
1831 	.cons           = IMX_CONSOLE,
1832 };
1833 
1834 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1835 {
1836 	struct imx_port *sport = platform_get_drvdata(dev);
1837 	unsigned int val;
1838 
1839 	/* enable wakeup from i.MX UART */
1840 	val = readl(sport->port.membase + UCR3);
1841 	val |= UCR3_AWAKEN;
1842 	writel(val, sport->port.membase + UCR3);
1843 
1844 	uart_suspend_port(&imx_reg, &sport->port);
1845 
1846 	return 0;
1847 }
1848 
1849 static int serial_imx_resume(struct platform_device *dev)
1850 {
1851 	struct imx_port *sport = platform_get_drvdata(dev);
1852 	unsigned int val;
1853 
1854 	/* disable wakeup from i.MX UART */
1855 	val = readl(sport->port.membase + UCR3);
1856 	val &= ~UCR3_AWAKEN;
1857 	writel(val, sport->port.membase + UCR3);
1858 
1859 	uart_resume_port(&imx_reg, &sport->port);
1860 
1861 	return 0;
1862 }
1863 
1864 #ifdef CONFIG_OF
1865 /*
1866  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1867  * could successfully get all information from dt or a negative errno.
1868  */
1869 static int serial_imx_probe_dt(struct imx_port *sport,
1870 		struct platform_device *pdev)
1871 {
1872 	struct device_node *np = pdev->dev.of_node;
1873 	const struct of_device_id *of_id =
1874 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1875 	int ret;
1876 
1877 	if (!np)
1878 		/* no device tree device */
1879 		return 1;
1880 
1881 	ret = of_alias_get_id(np, "serial");
1882 	if (ret < 0) {
1883 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1884 		return ret;
1885 	}
1886 	sport->port.line = ret;
1887 
1888 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1889 		sport->have_rtscts = 1;
1890 
1891 	if (of_get_property(np, "fsl,irda-mode", NULL))
1892 		sport->use_irda = 1;
1893 
1894 	if (of_get_property(np, "fsl,dte-mode", NULL))
1895 		sport->dte_mode = 1;
1896 
1897 	sport->devdata = of_id->data;
1898 
1899 	return 0;
1900 }
1901 #else
1902 static inline int serial_imx_probe_dt(struct imx_port *sport,
1903 		struct platform_device *pdev)
1904 {
1905 	return 1;
1906 }
1907 #endif
1908 
1909 static void serial_imx_probe_pdata(struct imx_port *sport,
1910 		struct platform_device *pdev)
1911 {
1912 	struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1913 
1914 	sport->port.line = pdev->id;
1915 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1916 
1917 	if (!pdata)
1918 		return;
1919 
1920 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1921 		sport->have_rtscts = 1;
1922 
1923 	if (pdata->flags & IMXUART_IRDA)
1924 		sport->use_irda = 1;
1925 }
1926 
1927 static int serial_imx_probe(struct platform_device *pdev)
1928 {
1929 	struct imx_port *sport;
1930 	struct imxuart_platform_data *pdata;
1931 	void __iomem *base;
1932 	int ret = 0;
1933 	struct resource *res;
1934 
1935 	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1936 	if (!sport)
1937 		return -ENOMEM;
1938 
1939 	ret = serial_imx_probe_dt(sport, pdev);
1940 	if (ret > 0)
1941 		serial_imx_probe_pdata(sport, pdev);
1942 	else if (ret < 0)
1943 		return ret;
1944 
1945 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1946 	if (!res)
1947 		return -ENODEV;
1948 
1949 	base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE);
1950 	if (!base)
1951 		return -ENOMEM;
1952 
1953 	sport->port.dev = &pdev->dev;
1954 	sport->port.mapbase = res->start;
1955 	sport->port.membase = base;
1956 	sport->port.type = PORT_IMX,
1957 	sport->port.iotype = UPIO_MEM;
1958 	sport->port.irq = platform_get_irq(pdev, 0);
1959 	sport->rxirq = platform_get_irq(pdev, 0);
1960 	sport->txirq = platform_get_irq(pdev, 1);
1961 	sport->rtsirq = platform_get_irq(pdev, 2);
1962 	sport->port.fifosize = 32;
1963 	sport->port.ops = &imx_pops;
1964 	sport->port.flags = UPF_BOOT_AUTOCONF;
1965 	init_timer(&sport->timer);
1966 	sport->timer.function = imx_timeout;
1967 	sport->timer.data     = (unsigned long)sport;
1968 
1969 	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1970 	if (IS_ERR(sport->clk_ipg)) {
1971 		ret = PTR_ERR(sport->clk_ipg);
1972 		dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1973 		return ret;
1974 	}
1975 
1976 	sport->clk_per = devm_clk_get(&pdev->dev, "per");
1977 	if (IS_ERR(sport->clk_per)) {
1978 		ret = PTR_ERR(sport->clk_per);
1979 		dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1980 		return ret;
1981 	}
1982 
1983 	sport->port.uartclk = clk_get_rate(sport->clk_per);
1984 
1985 	imx_ports[sport->port.line] = sport;
1986 
1987 	pdata = dev_get_platdata(&pdev->dev);
1988 	if (pdata && pdata->init) {
1989 		ret = pdata->init(pdev);
1990 		if (ret)
1991 			return ret;
1992 	}
1993 
1994 	ret = uart_add_one_port(&imx_reg, &sport->port);
1995 	if (ret)
1996 		goto deinit;
1997 	platform_set_drvdata(pdev, sport);
1998 
1999 	return 0;
2000 deinit:
2001 	if (pdata && pdata->exit)
2002 		pdata->exit(pdev);
2003 	return ret;
2004 }
2005 
2006 static int serial_imx_remove(struct platform_device *pdev)
2007 {
2008 	struct imxuart_platform_data *pdata;
2009 	struct imx_port *sport = platform_get_drvdata(pdev);
2010 
2011 	pdata = dev_get_platdata(&pdev->dev);
2012 
2013 	uart_remove_one_port(&imx_reg, &sport->port);
2014 
2015 	if (pdata && pdata->exit)
2016 		pdata->exit(pdev);
2017 
2018 	return 0;
2019 }
2020 
2021 static struct platform_driver serial_imx_driver = {
2022 	.probe		= serial_imx_probe,
2023 	.remove		= serial_imx_remove,
2024 
2025 	.suspend	= serial_imx_suspend,
2026 	.resume		= serial_imx_resume,
2027 	.id_table	= imx_uart_devtype,
2028 	.driver		= {
2029 		.name	= "imx-uart",
2030 		.owner	= THIS_MODULE,
2031 		.of_match_table = imx_uart_dt_ids,
2032 	},
2033 };
2034 
2035 static int __init imx_serial_init(void)
2036 {
2037 	int ret;
2038 
2039 	pr_info("Serial: IMX driver\n");
2040 
2041 	ret = uart_register_driver(&imx_reg);
2042 	if (ret)
2043 		return ret;
2044 
2045 	ret = platform_driver_register(&serial_imx_driver);
2046 	if (ret != 0)
2047 		uart_unregister_driver(&imx_reg);
2048 
2049 	return ret;
2050 }
2051 
2052 static void __exit imx_serial_exit(void)
2053 {
2054 	platform_driver_unregister(&serial_imx_driver);
2055 	uart_unregister_driver(&imx_reg);
2056 }
2057 
2058 module_init(imx_serial_init);
2059 module_exit(imx_serial_exit);
2060 
2061 MODULE_AUTHOR("Sascha Hauer");
2062 MODULE_DESCRIPTION("IMX generic serial port driver");
2063 MODULE_LICENSE("GPL");
2064 MODULE_ALIAS("platform:imx-uart");
2065