xref: /openbmc/linux/drivers/tty/serial/imx.c (revision 8a10bc9d)
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 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
810 		tmp |= TIOCM_LOOP;
811 
812 	return tmp;
813 }
814 
815 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
816 {
817 	struct imx_port *sport = (struct imx_port *)port;
818 	unsigned long temp;
819 
820 	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
821 
822 	if (mctrl & TIOCM_RTS)
823 		if (!sport->dma_is_enabled)
824 			temp |= UCR2_CTS;
825 
826 	writel(temp, sport->port.membase + UCR2);
827 
828 	temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
829 	if (mctrl & TIOCM_LOOP)
830 		temp |= UTS_LOOP;
831 	writel(temp, sport->port.membase + uts_reg(sport));
832 }
833 
834 /*
835  * Interrupts always disabled.
836  */
837 static void imx_break_ctl(struct uart_port *port, int break_state)
838 {
839 	struct imx_port *sport = (struct imx_port *)port;
840 	unsigned long flags, temp;
841 
842 	spin_lock_irqsave(&sport->port.lock, flags);
843 
844 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
845 
846 	if (break_state != 0)
847 		temp |= UCR1_SNDBRK;
848 
849 	writel(temp, sport->port.membase + UCR1);
850 
851 	spin_unlock_irqrestore(&sport->port.lock, flags);
852 }
853 
854 #define TXTL 2 /* reset default */
855 #define RXTL 1 /* reset default */
856 
857 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
858 {
859 	unsigned int val;
860 
861 	/* set receiver / transmitter trigger level */
862 	val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
863 	val |= TXTL << UFCR_TXTL_SHF | RXTL;
864 	writel(val, sport->port.membase + UFCR);
865 	return 0;
866 }
867 
868 #define RX_BUF_SIZE	(PAGE_SIZE)
869 static void imx_rx_dma_done(struct imx_port *sport)
870 {
871 	unsigned long temp;
872 
873 	/* Enable this interrupt when the RXFIFO is empty. */
874 	temp = readl(sport->port.membase + UCR1);
875 	temp |= UCR1_RRDYEN;
876 	writel(temp, sport->port.membase + UCR1);
877 
878 	sport->dma_is_rxing = 0;
879 
880 	/* Is the shutdown waiting for us? */
881 	if (waitqueue_active(&sport->dma_wait))
882 		wake_up(&sport->dma_wait);
883 }
884 
885 /*
886  * There are three kinds of RX DMA interrupts(such as in the MX6Q):
887  *   [1] the RX DMA buffer is full.
888  *   [2] the Aging timer expires(wait for 8 bytes long)
889  *   [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
890  *
891  * The [2] is trigger when a character was been sitting in the FIFO
892  * meanwhile [3] can wait for 32 bytes long when the RX line is
893  * on IDLE state and RxFIFO is empty.
894  */
895 static void dma_rx_callback(void *data)
896 {
897 	struct imx_port *sport = data;
898 	struct dma_chan	*chan = sport->dma_chan_rx;
899 	struct scatterlist *sgl = &sport->rx_sgl;
900 	struct tty_port *port = &sport->port.state->port;
901 	struct dma_tx_state state;
902 	enum dma_status status;
903 	unsigned int count;
904 
905 	/* unmap it first */
906 	dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
907 
908 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
909 	count = RX_BUF_SIZE - state.residue;
910 	dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
911 
912 	if (count) {
913 		tty_insert_flip_string(port, sport->rx_buf, count);
914 		tty_flip_buffer_push(port);
915 
916 		start_rx_dma(sport);
917 	} else
918 		imx_rx_dma_done(sport);
919 }
920 
921 static int start_rx_dma(struct imx_port *sport)
922 {
923 	struct scatterlist *sgl = &sport->rx_sgl;
924 	struct dma_chan	*chan = sport->dma_chan_rx;
925 	struct device *dev = sport->port.dev;
926 	struct dma_async_tx_descriptor *desc;
927 	int ret;
928 
929 	sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
930 	ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
931 	if (ret == 0) {
932 		dev_err(dev, "DMA mapping error for RX.\n");
933 		return -EINVAL;
934 	}
935 	desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
936 					DMA_PREP_INTERRUPT);
937 	if (!desc) {
938 		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
939 		return -EINVAL;
940 	}
941 	desc->callback = dma_rx_callback;
942 	desc->callback_param = sport;
943 
944 	dev_dbg(dev, "RX: prepare for the DMA.\n");
945 	dmaengine_submit(desc);
946 	dma_async_issue_pending(chan);
947 	return 0;
948 }
949 
950 static void imx_uart_dma_exit(struct imx_port *sport)
951 {
952 	if (sport->dma_chan_rx) {
953 		dma_release_channel(sport->dma_chan_rx);
954 		sport->dma_chan_rx = NULL;
955 
956 		kfree(sport->rx_buf);
957 		sport->rx_buf = NULL;
958 	}
959 
960 	if (sport->dma_chan_tx) {
961 		dma_release_channel(sport->dma_chan_tx);
962 		sport->dma_chan_tx = NULL;
963 	}
964 
965 	sport->dma_is_inited = 0;
966 }
967 
968 static int imx_uart_dma_init(struct imx_port *sport)
969 {
970 	struct dma_slave_config slave_config = {};
971 	struct device *dev = sport->port.dev;
972 	int ret;
973 
974 	/* Prepare for RX : */
975 	sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
976 	if (!sport->dma_chan_rx) {
977 		dev_dbg(dev, "cannot get the DMA channel.\n");
978 		ret = -EINVAL;
979 		goto err;
980 	}
981 
982 	slave_config.direction = DMA_DEV_TO_MEM;
983 	slave_config.src_addr = sport->port.mapbase + URXD0;
984 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
985 	slave_config.src_maxburst = RXTL;
986 	ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
987 	if (ret) {
988 		dev_err(dev, "error in RX dma configuration.\n");
989 		goto err;
990 	}
991 
992 	sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
993 	if (!sport->rx_buf) {
994 		dev_err(dev, "cannot alloc DMA buffer.\n");
995 		ret = -ENOMEM;
996 		goto err;
997 	}
998 
999 	/* Prepare for TX : */
1000 	sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1001 	if (!sport->dma_chan_tx) {
1002 		dev_err(dev, "cannot get the TX DMA channel!\n");
1003 		ret = -EINVAL;
1004 		goto err;
1005 	}
1006 
1007 	slave_config.direction = DMA_MEM_TO_DEV;
1008 	slave_config.dst_addr = sport->port.mapbase + URTX0;
1009 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1010 	slave_config.dst_maxburst = TXTL;
1011 	ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1012 	if (ret) {
1013 		dev_err(dev, "error in TX dma configuration.");
1014 		goto err;
1015 	}
1016 
1017 	sport->dma_is_inited = 1;
1018 
1019 	return 0;
1020 err:
1021 	imx_uart_dma_exit(sport);
1022 	return ret;
1023 }
1024 
1025 static void imx_enable_dma(struct imx_port *sport)
1026 {
1027 	unsigned long temp;
1028 
1029 	init_waitqueue_head(&sport->dma_wait);
1030 
1031 	/* set UCR1 */
1032 	temp = readl(sport->port.membase + UCR1);
1033 	temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1034 		/* wait for 32 idle frames for IDDMA interrupt */
1035 		UCR1_ICD_REG(3);
1036 	writel(temp, sport->port.membase + UCR1);
1037 
1038 	/* set UCR4 */
1039 	temp = readl(sport->port.membase + UCR4);
1040 	temp |= UCR4_IDDMAEN;
1041 	writel(temp, sport->port.membase + UCR4);
1042 
1043 	sport->dma_is_enabled = 1;
1044 }
1045 
1046 static void imx_disable_dma(struct imx_port *sport)
1047 {
1048 	unsigned long temp;
1049 
1050 	/* clear UCR1 */
1051 	temp = readl(sport->port.membase + UCR1);
1052 	temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1053 	writel(temp, sport->port.membase + UCR1);
1054 
1055 	/* clear UCR2 */
1056 	temp = readl(sport->port.membase + UCR2);
1057 	temp &= ~(UCR2_CTSC | UCR2_CTS);
1058 	writel(temp, sport->port.membase + UCR2);
1059 
1060 	/* clear UCR4 */
1061 	temp = readl(sport->port.membase + UCR4);
1062 	temp &= ~UCR4_IDDMAEN;
1063 	writel(temp, sport->port.membase + UCR4);
1064 
1065 	sport->dma_is_enabled = 0;
1066 }
1067 
1068 /* half the RX buffer size */
1069 #define CTSTL 16
1070 
1071 static int imx_startup(struct uart_port *port)
1072 {
1073 	struct imx_port *sport = (struct imx_port *)port;
1074 	int retval;
1075 	unsigned long flags, temp;
1076 
1077 	retval = clk_prepare_enable(sport->clk_per);
1078 	if (retval)
1079 		goto error_out1;
1080 	retval = clk_prepare_enable(sport->clk_ipg);
1081 	if (retval) {
1082 		clk_disable_unprepare(sport->clk_per);
1083 		goto error_out1;
1084 	}
1085 
1086 	imx_setup_ufcr(sport, 0);
1087 
1088 	/* disable the DREN bit (Data Ready interrupt enable) before
1089 	 * requesting IRQs
1090 	 */
1091 	temp = readl(sport->port.membase + UCR4);
1092 
1093 	if (USE_IRDA(sport))
1094 		temp |= UCR4_IRSC;
1095 
1096 	/* set the trigger level for CTS */
1097 	temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1098 	temp |= CTSTL << UCR4_CTSTL_SHF;
1099 
1100 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1101 
1102 	if (USE_IRDA(sport)) {
1103 		/* reset fifo's and state machines */
1104 		int i = 100;
1105 		temp = readl(sport->port.membase + UCR2);
1106 		temp &= ~UCR2_SRST;
1107 		writel(temp, sport->port.membase + UCR2);
1108 		while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
1109 		    (--i > 0)) {
1110 			udelay(1);
1111 		}
1112 	}
1113 
1114 	/*
1115 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1116 	 * chips only have one interrupt.
1117 	 */
1118 	if (sport->txirq > 0) {
1119 		retval = request_irq(sport->rxirq, imx_rxint, 0,
1120 				DRIVER_NAME, sport);
1121 		if (retval)
1122 			goto error_out1;
1123 
1124 		retval = request_irq(sport->txirq, imx_txint, 0,
1125 				DRIVER_NAME, sport);
1126 		if (retval)
1127 			goto error_out2;
1128 
1129 		/* do not use RTS IRQ on IrDA */
1130 		if (!USE_IRDA(sport)) {
1131 			retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1132 					DRIVER_NAME, sport);
1133 			if (retval)
1134 				goto error_out3;
1135 		}
1136 	} else {
1137 		retval = request_irq(sport->port.irq, imx_int, 0,
1138 				DRIVER_NAME, sport);
1139 		if (retval) {
1140 			free_irq(sport->port.irq, sport);
1141 			goto error_out1;
1142 		}
1143 	}
1144 
1145 	spin_lock_irqsave(&sport->port.lock, flags);
1146 	/*
1147 	 * Finally, clear and enable interrupts
1148 	 */
1149 	writel(USR1_RTSD, sport->port.membase + USR1);
1150 
1151 	temp = readl(sport->port.membase + UCR1);
1152 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1153 
1154 	if (USE_IRDA(sport)) {
1155 		temp |= UCR1_IREN;
1156 		temp &= ~(UCR1_RTSDEN);
1157 	}
1158 
1159 	writel(temp, sport->port.membase + UCR1);
1160 
1161 	temp = readl(sport->port.membase + UCR2);
1162 	temp |= (UCR2_RXEN | UCR2_TXEN);
1163 	if (!sport->have_rtscts)
1164 		temp |= UCR2_IRTS;
1165 	writel(temp, sport->port.membase + UCR2);
1166 
1167 	if (USE_IRDA(sport)) {
1168 		/* clear RX-FIFO */
1169 		int i = 64;
1170 		while ((--i > 0) &&
1171 			(readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
1172 			barrier();
1173 		}
1174 	}
1175 
1176 	if (!is_imx1_uart(sport)) {
1177 		temp = readl(sport->port.membase + UCR3);
1178 		temp |= IMX21_UCR3_RXDMUXSEL;
1179 		writel(temp, sport->port.membase + UCR3);
1180 	}
1181 
1182 	if (USE_IRDA(sport)) {
1183 		temp = readl(sport->port.membase + UCR4);
1184 		if (sport->irda_inv_rx)
1185 			temp |= UCR4_INVR;
1186 		else
1187 			temp &= ~(UCR4_INVR);
1188 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1189 
1190 		temp = readl(sport->port.membase + UCR3);
1191 		if (sport->irda_inv_tx)
1192 			temp |= UCR3_INVT;
1193 		else
1194 			temp &= ~(UCR3_INVT);
1195 		writel(temp, sport->port.membase + UCR3);
1196 	}
1197 
1198 	/*
1199 	 * Enable modem status interrupts
1200 	 */
1201 	imx_enable_ms(&sport->port);
1202 	spin_unlock_irqrestore(&sport->port.lock, flags);
1203 
1204 	if (USE_IRDA(sport)) {
1205 		struct imxuart_platform_data *pdata;
1206 		pdata = dev_get_platdata(sport->port.dev);
1207 		sport->irda_inv_rx = pdata->irda_inv_rx;
1208 		sport->irda_inv_tx = pdata->irda_inv_tx;
1209 		sport->trcv_delay = pdata->transceiver_delay;
1210 		if (pdata->irda_enable)
1211 			pdata->irda_enable(1);
1212 	}
1213 
1214 	return 0;
1215 
1216 error_out3:
1217 	if (sport->txirq)
1218 		free_irq(sport->txirq, sport);
1219 error_out2:
1220 	if (sport->rxirq)
1221 		free_irq(sport->rxirq, sport);
1222 error_out1:
1223 	return retval;
1224 }
1225 
1226 static void imx_shutdown(struct uart_port *port)
1227 {
1228 	struct imx_port *sport = (struct imx_port *)port;
1229 	unsigned long temp;
1230 	unsigned long flags;
1231 
1232 	if (sport->dma_is_enabled) {
1233 		/* We have to wait for the DMA to finish. */
1234 		wait_event(sport->dma_wait,
1235 			!sport->dma_is_rxing && !sport->dma_is_txing);
1236 		imx_stop_rx(port);
1237 		imx_disable_dma(sport);
1238 		imx_uart_dma_exit(sport);
1239 	}
1240 
1241 	spin_lock_irqsave(&sport->port.lock, flags);
1242 	temp = readl(sport->port.membase + UCR2);
1243 	temp &= ~(UCR2_TXEN);
1244 	writel(temp, sport->port.membase + UCR2);
1245 	spin_unlock_irqrestore(&sport->port.lock, flags);
1246 
1247 	if (USE_IRDA(sport)) {
1248 		struct imxuart_platform_data *pdata;
1249 		pdata = dev_get_platdata(sport->port.dev);
1250 		if (pdata->irda_enable)
1251 			pdata->irda_enable(0);
1252 	}
1253 
1254 	/*
1255 	 * Stop our timer.
1256 	 */
1257 	del_timer_sync(&sport->timer);
1258 
1259 	/*
1260 	 * Free the interrupts
1261 	 */
1262 	if (sport->txirq > 0) {
1263 		if (!USE_IRDA(sport))
1264 			free_irq(sport->rtsirq, sport);
1265 		free_irq(sport->txirq, sport);
1266 		free_irq(sport->rxirq, sport);
1267 	} else
1268 		free_irq(sport->port.irq, sport);
1269 
1270 	/*
1271 	 * Disable all interrupts, port and break condition.
1272 	 */
1273 
1274 	spin_lock_irqsave(&sport->port.lock, flags);
1275 	temp = readl(sport->port.membase + UCR1);
1276 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1277 	if (USE_IRDA(sport))
1278 		temp &= ~(UCR1_IREN);
1279 
1280 	writel(temp, sport->port.membase + UCR1);
1281 	spin_unlock_irqrestore(&sport->port.lock, flags);
1282 
1283 	clk_disable_unprepare(sport->clk_per);
1284 	clk_disable_unprepare(sport->clk_ipg);
1285 }
1286 
1287 static void imx_flush_buffer(struct uart_port *port)
1288 {
1289 	struct imx_port *sport = (struct imx_port *)port;
1290 
1291 	if (sport->dma_is_enabled) {
1292 		sport->tx_bytes = 0;
1293 		dmaengine_terminate_all(sport->dma_chan_tx);
1294 	}
1295 }
1296 
1297 static void
1298 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1299 		   struct ktermios *old)
1300 {
1301 	struct imx_port *sport = (struct imx_port *)port;
1302 	unsigned long flags;
1303 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1304 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1305 	unsigned int div, ufcr;
1306 	unsigned long num, denom;
1307 	uint64_t tdiv64;
1308 
1309 	/*
1310 	 * If we don't support modem control lines, don't allow
1311 	 * these to be set.
1312 	 */
1313 	if (0) {
1314 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1315 		termios->c_cflag |= CLOCAL;
1316 	}
1317 
1318 	/*
1319 	 * We only support CS7 and CS8.
1320 	 */
1321 	while ((termios->c_cflag & CSIZE) != CS7 &&
1322 	       (termios->c_cflag & CSIZE) != CS8) {
1323 		termios->c_cflag &= ~CSIZE;
1324 		termios->c_cflag |= old_csize;
1325 		old_csize = CS8;
1326 	}
1327 
1328 	if ((termios->c_cflag & CSIZE) == CS8)
1329 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1330 	else
1331 		ucr2 = UCR2_SRST | UCR2_IRTS;
1332 
1333 	if (termios->c_cflag & CRTSCTS) {
1334 		if (sport->have_rtscts) {
1335 			ucr2 &= ~UCR2_IRTS;
1336 			ucr2 |= UCR2_CTSC;
1337 
1338 			/* Can we enable the DMA support? */
1339 			if (is_imx6q_uart(sport) && !uart_console(port)
1340 				&& !sport->dma_is_inited)
1341 				imx_uart_dma_init(sport);
1342 		} else {
1343 			termios->c_cflag &= ~CRTSCTS;
1344 		}
1345 	}
1346 
1347 	if (termios->c_cflag & CSTOPB)
1348 		ucr2 |= UCR2_STPB;
1349 	if (termios->c_cflag & PARENB) {
1350 		ucr2 |= UCR2_PREN;
1351 		if (termios->c_cflag & PARODD)
1352 			ucr2 |= UCR2_PROE;
1353 	}
1354 
1355 	del_timer_sync(&sport->timer);
1356 
1357 	/*
1358 	 * Ask the core to calculate the divisor for us.
1359 	 */
1360 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1361 	quot = uart_get_divisor(port, baud);
1362 
1363 	spin_lock_irqsave(&sport->port.lock, flags);
1364 
1365 	sport->port.read_status_mask = 0;
1366 	if (termios->c_iflag & INPCK)
1367 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1368 	if (termios->c_iflag & (BRKINT | PARMRK))
1369 		sport->port.read_status_mask |= URXD_BRK;
1370 
1371 	/*
1372 	 * Characters to ignore
1373 	 */
1374 	sport->port.ignore_status_mask = 0;
1375 	if (termios->c_iflag & IGNPAR)
1376 		sport->port.ignore_status_mask |= URXD_PRERR;
1377 	if (termios->c_iflag & IGNBRK) {
1378 		sport->port.ignore_status_mask |= URXD_BRK;
1379 		/*
1380 		 * If we're ignoring parity and break indicators,
1381 		 * ignore overruns too (for real raw support).
1382 		 */
1383 		if (termios->c_iflag & IGNPAR)
1384 			sport->port.ignore_status_mask |= URXD_OVRRUN;
1385 	}
1386 
1387 	/*
1388 	 * Update the per-port timeout.
1389 	 */
1390 	uart_update_timeout(port, termios->c_cflag, baud);
1391 
1392 	/*
1393 	 * disable interrupts and drain transmitter
1394 	 */
1395 	old_ucr1 = readl(sport->port.membase + UCR1);
1396 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1397 			sport->port.membase + UCR1);
1398 
1399 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1400 		barrier();
1401 
1402 	/* then, disable everything */
1403 	old_txrxen = readl(sport->port.membase + UCR2);
1404 	writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1405 			sport->port.membase + UCR2);
1406 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1407 
1408 	if (USE_IRDA(sport)) {
1409 		/*
1410 		 * use maximum available submodule frequency to
1411 		 * avoid missing short pulses due to low sampling rate
1412 		 */
1413 		div = 1;
1414 	} else {
1415 		/* custom-baudrate handling */
1416 		div = sport->port.uartclk / (baud * 16);
1417 		if (baud == 38400 && quot != div)
1418 			baud = sport->port.uartclk / (quot * 16);
1419 
1420 		div = sport->port.uartclk / (baud * 16);
1421 		if (div > 7)
1422 			div = 7;
1423 		if (!div)
1424 			div = 1;
1425 	}
1426 
1427 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1428 		1 << 16, 1 << 16, &num, &denom);
1429 
1430 	tdiv64 = sport->port.uartclk;
1431 	tdiv64 *= num;
1432 	do_div(tdiv64, denom * 16 * div);
1433 	tty_termios_encode_baud_rate(termios,
1434 				(speed_t)tdiv64, (speed_t)tdiv64);
1435 
1436 	num -= 1;
1437 	denom -= 1;
1438 
1439 	ufcr = readl(sport->port.membase + UFCR);
1440 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1441 	if (sport->dte_mode)
1442 		ufcr |= UFCR_DCEDTE;
1443 	writel(ufcr, sport->port.membase + UFCR);
1444 
1445 	writel(num, sport->port.membase + UBIR);
1446 	writel(denom, sport->port.membase + UBMR);
1447 
1448 	if (!is_imx1_uart(sport))
1449 		writel(sport->port.uartclk / div / 1000,
1450 				sport->port.membase + IMX21_ONEMS);
1451 
1452 	writel(old_ucr1, sport->port.membase + UCR1);
1453 
1454 	/* set the parity, stop bits and data size */
1455 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1456 
1457 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1458 		imx_enable_ms(&sport->port);
1459 
1460 	if (sport->dma_is_inited && !sport->dma_is_enabled)
1461 		imx_enable_dma(sport);
1462 	spin_unlock_irqrestore(&sport->port.lock, flags);
1463 }
1464 
1465 static const char *imx_type(struct uart_port *port)
1466 {
1467 	struct imx_port *sport = (struct imx_port *)port;
1468 
1469 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1470 }
1471 
1472 /*
1473  * Release the memory region(s) being used by 'port'.
1474  */
1475 static void imx_release_port(struct uart_port *port)
1476 {
1477 	struct platform_device *pdev = to_platform_device(port->dev);
1478 	struct resource *mmres;
1479 
1480 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1481 	release_mem_region(mmres->start, resource_size(mmres));
1482 }
1483 
1484 /*
1485  * Request the memory region(s) being used by 'port'.
1486  */
1487 static int imx_request_port(struct uart_port *port)
1488 {
1489 	struct platform_device *pdev = to_platform_device(port->dev);
1490 	struct resource *mmres;
1491 	void *ret;
1492 
1493 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1494 	if (!mmres)
1495 		return -ENODEV;
1496 
1497 	ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
1498 
1499 	return  ret ? 0 : -EBUSY;
1500 }
1501 
1502 /*
1503  * Configure/autoconfigure the port.
1504  */
1505 static void imx_config_port(struct uart_port *port, int flags)
1506 {
1507 	struct imx_port *sport = (struct imx_port *)port;
1508 
1509 	if (flags & UART_CONFIG_TYPE &&
1510 	    imx_request_port(&sport->port) == 0)
1511 		sport->port.type = PORT_IMX;
1512 }
1513 
1514 /*
1515  * Verify the new serial_struct (for TIOCSSERIAL).
1516  * The only change we allow are to the flags and type, and
1517  * even then only between PORT_IMX and PORT_UNKNOWN
1518  */
1519 static int
1520 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1521 {
1522 	struct imx_port *sport = (struct imx_port *)port;
1523 	int ret = 0;
1524 
1525 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1526 		ret = -EINVAL;
1527 	if (sport->port.irq != ser->irq)
1528 		ret = -EINVAL;
1529 	if (ser->io_type != UPIO_MEM)
1530 		ret = -EINVAL;
1531 	if (sport->port.uartclk / 16 != ser->baud_base)
1532 		ret = -EINVAL;
1533 	if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1534 		ret = -EINVAL;
1535 	if (sport->port.iobase != ser->port)
1536 		ret = -EINVAL;
1537 	if (ser->hub6 != 0)
1538 		ret = -EINVAL;
1539 	return ret;
1540 }
1541 
1542 #if defined(CONFIG_CONSOLE_POLL)
1543 static int imx_poll_get_char(struct uart_port *port)
1544 {
1545 	struct imx_port_ucrs old_ucr;
1546 	unsigned int status;
1547 	unsigned char c;
1548 
1549 	/* save control registers */
1550 	imx_port_ucrs_save(port, &old_ucr);
1551 
1552 	/* disable interrupts */
1553 	writel(UCR1_UARTEN, port->membase + UCR1);
1554 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1555 	       port->membase + UCR2);
1556 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1557 	       port->membase + UCR3);
1558 
1559 	/* poll */
1560 	do {
1561 		status = readl(port->membase + USR2);
1562 	} while (~status & USR2_RDR);
1563 
1564 	/* read */
1565 	c = readl(port->membase + URXD0);
1566 
1567 	/* restore control registers */
1568 	imx_port_ucrs_restore(port, &old_ucr);
1569 
1570 	return c;
1571 }
1572 
1573 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1574 {
1575 	struct imx_port_ucrs old_ucr;
1576 	unsigned int status;
1577 
1578 	/* save control registers */
1579 	imx_port_ucrs_save(port, &old_ucr);
1580 
1581 	/* disable interrupts */
1582 	writel(UCR1_UARTEN, port->membase + UCR1);
1583 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1584 	       port->membase + UCR2);
1585 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1586 	       port->membase + UCR3);
1587 
1588 	/* drain */
1589 	do {
1590 		status = readl(port->membase + USR1);
1591 	} while (~status & USR1_TRDY);
1592 
1593 	/* write */
1594 	writel(c, port->membase + URTX0);
1595 
1596 	/* flush */
1597 	do {
1598 		status = readl(port->membase + USR2);
1599 	} while (~status & USR2_TXDC);
1600 
1601 	/* restore control registers */
1602 	imx_port_ucrs_restore(port, &old_ucr);
1603 }
1604 #endif
1605 
1606 static struct uart_ops imx_pops = {
1607 	.tx_empty	= imx_tx_empty,
1608 	.set_mctrl	= imx_set_mctrl,
1609 	.get_mctrl	= imx_get_mctrl,
1610 	.stop_tx	= imx_stop_tx,
1611 	.start_tx	= imx_start_tx,
1612 	.stop_rx	= imx_stop_rx,
1613 	.enable_ms	= imx_enable_ms,
1614 	.break_ctl	= imx_break_ctl,
1615 	.startup	= imx_startup,
1616 	.shutdown	= imx_shutdown,
1617 	.flush_buffer	= imx_flush_buffer,
1618 	.set_termios	= imx_set_termios,
1619 	.type		= imx_type,
1620 	.release_port	= imx_release_port,
1621 	.request_port	= imx_request_port,
1622 	.config_port	= imx_config_port,
1623 	.verify_port	= imx_verify_port,
1624 #if defined(CONFIG_CONSOLE_POLL)
1625 	.poll_get_char  = imx_poll_get_char,
1626 	.poll_put_char  = imx_poll_put_char,
1627 #endif
1628 };
1629 
1630 static struct imx_port *imx_ports[UART_NR];
1631 
1632 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1633 static void imx_console_putchar(struct uart_port *port, int ch)
1634 {
1635 	struct imx_port *sport = (struct imx_port *)port;
1636 
1637 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1638 		barrier();
1639 
1640 	writel(ch, sport->port.membase + URTX0);
1641 }
1642 
1643 /*
1644  * Interrupts are disabled on entering
1645  */
1646 static void
1647 imx_console_write(struct console *co, const char *s, unsigned int count)
1648 {
1649 	struct imx_port *sport = imx_ports[co->index];
1650 	struct imx_port_ucrs old_ucr;
1651 	unsigned int ucr1;
1652 	unsigned long flags = 0;
1653 	int locked = 1;
1654 	int retval;
1655 
1656 	retval = clk_enable(sport->clk_per);
1657 	if (retval)
1658 		return;
1659 	retval = clk_enable(sport->clk_ipg);
1660 	if (retval) {
1661 		clk_disable(sport->clk_per);
1662 		return;
1663 	}
1664 
1665 	if (sport->port.sysrq)
1666 		locked = 0;
1667 	else if (oops_in_progress)
1668 		locked = spin_trylock_irqsave(&sport->port.lock, flags);
1669 	else
1670 		spin_lock_irqsave(&sport->port.lock, flags);
1671 
1672 	/*
1673 	 *	First, save UCR1/2/3 and then disable interrupts
1674 	 */
1675 	imx_port_ucrs_save(&sport->port, &old_ucr);
1676 	ucr1 = old_ucr.ucr1;
1677 
1678 	if (is_imx1_uart(sport))
1679 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1680 	ucr1 |= UCR1_UARTEN;
1681 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1682 
1683 	writel(ucr1, sport->port.membase + UCR1);
1684 
1685 	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1686 
1687 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1688 
1689 	/*
1690 	 *	Finally, wait for transmitter to become empty
1691 	 *	and restore UCR1/2/3
1692 	 */
1693 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1694 
1695 	imx_port_ucrs_restore(&sport->port, &old_ucr);
1696 
1697 	if (locked)
1698 		spin_unlock_irqrestore(&sport->port.lock, flags);
1699 
1700 	clk_disable(sport->clk_ipg);
1701 	clk_disable(sport->clk_per);
1702 }
1703 
1704 /*
1705  * If the port was already initialised (eg, by a boot loader),
1706  * try to determine the current setup.
1707  */
1708 static void __init
1709 imx_console_get_options(struct imx_port *sport, int *baud,
1710 			   int *parity, int *bits)
1711 {
1712 
1713 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1714 		/* ok, the port was enabled */
1715 		unsigned int ucr2, ubir, ubmr, uartclk;
1716 		unsigned int baud_raw;
1717 		unsigned int ucfr_rfdiv;
1718 
1719 		ucr2 = readl(sport->port.membase + UCR2);
1720 
1721 		*parity = 'n';
1722 		if (ucr2 & UCR2_PREN) {
1723 			if (ucr2 & UCR2_PROE)
1724 				*parity = 'o';
1725 			else
1726 				*parity = 'e';
1727 		}
1728 
1729 		if (ucr2 & UCR2_WS)
1730 			*bits = 8;
1731 		else
1732 			*bits = 7;
1733 
1734 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1735 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1736 
1737 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1738 		if (ucfr_rfdiv == 6)
1739 			ucfr_rfdiv = 7;
1740 		else
1741 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1742 
1743 		uartclk = clk_get_rate(sport->clk_per);
1744 		uartclk /= ucfr_rfdiv;
1745 
1746 		{	/*
1747 			 * The next code provides exact computation of
1748 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1749 			 * without need of float support or long long division,
1750 			 * which would be required to prevent 32bit arithmetic overflow
1751 			 */
1752 			unsigned int mul = ubir + 1;
1753 			unsigned int div = 16 * (ubmr + 1);
1754 			unsigned int rem = uartclk % div;
1755 
1756 			baud_raw = (uartclk / div) * mul;
1757 			baud_raw += (rem * mul + div / 2) / div;
1758 			*baud = (baud_raw + 50) / 100 * 100;
1759 		}
1760 
1761 		if (*baud != baud_raw)
1762 			pr_info("Console IMX rounded baud rate from %d to %d\n",
1763 				baud_raw, *baud);
1764 	}
1765 }
1766 
1767 static int __init
1768 imx_console_setup(struct console *co, char *options)
1769 {
1770 	struct imx_port *sport;
1771 	int baud = 9600;
1772 	int bits = 8;
1773 	int parity = 'n';
1774 	int flow = 'n';
1775 	int retval;
1776 
1777 	/*
1778 	 * Check whether an invalid uart number has been specified, and
1779 	 * if so, search for the first available port that does have
1780 	 * console support.
1781 	 */
1782 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1783 		co->index = 0;
1784 	sport = imx_ports[co->index];
1785 	if (sport == NULL)
1786 		return -ENODEV;
1787 
1788 	/* For setting the registers, we only need to enable the ipg clock. */
1789 	retval = clk_prepare_enable(sport->clk_ipg);
1790 	if (retval)
1791 		goto error_console;
1792 
1793 	if (options)
1794 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1795 	else
1796 		imx_console_get_options(sport, &baud, &parity, &bits);
1797 
1798 	imx_setup_ufcr(sport, 0);
1799 
1800 	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1801 
1802 	clk_disable(sport->clk_ipg);
1803 	if (retval) {
1804 		clk_unprepare(sport->clk_ipg);
1805 		goto error_console;
1806 	}
1807 
1808 	retval = clk_prepare(sport->clk_per);
1809 	if (retval)
1810 		clk_disable_unprepare(sport->clk_ipg);
1811 
1812 error_console:
1813 	return retval;
1814 }
1815 
1816 static struct uart_driver imx_reg;
1817 static struct console imx_console = {
1818 	.name		= DEV_NAME,
1819 	.write		= imx_console_write,
1820 	.device		= uart_console_device,
1821 	.setup		= imx_console_setup,
1822 	.flags		= CON_PRINTBUFFER,
1823 	.index		= -1,
1824 	.data		= &imx_reg,
1825 };
1826 
1827 #define IMX_CONSOLE	&imx_console
1828 #else
1829 #define IMX_CONSOLE	NULL
1830 #endif
1831 
1832 static struct uart_driver imx_reg = {
1833 	.owner          = THIS_MODULE,
1834 	.driver_name    = DRIVER_NAME,
1835 	.dev_name       = DEV_NAME,
1836 	.major          = SERIAL_IMX_MAJOR,
1837 	.minor          = MINOR_START,
1838 	.nr             = ARRAY_SIZE(imx_ports),
1839 	.cons           = IMX_CONSOLE,
1840 };
1841 
1842 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1843 {
1844 	struct imx_port *sport = platform_get_drvdata(dev);
1845 	unsigned int val;
1846 
1847 	/* enable wakeup from i.MX UART */
1848 	val = readl(sport->port.membase + UCR3);
1849 	val |= UCR3_AWAKEN;
1850 	writel(val, sport->port.membase + UCR3);
1851 
1852 	uart_suspend_port(&imx_reg, &sport->port);
1853 
1854 	return 0;
1855 }
1856 
1857 static int serial_imx_resume(struct platform_device *dev)
1858 {
1859 	struct imx_port *sport = platform_get_drvdata(dev);
1860 	unsigned int val;
1861 
1862 	/* disable wakeup from i.MX UART */
1863 	val = readl(sport->port.membase + UCR3);
1864 	val &= ~UCR3_AWAKEN;
1865 	writel(val, sport->port.membase + UCR3);
1866 
1867 	uart_resume_port(&imx_reg, &sport->port);
1868 
1869 	return 0;
1870 }
1871 
1872 #ifdef CONFIG_OF
1873 /*
1874  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1875  * could successfully get all information from dt or a negative errno.
1876  */
1877 static int serial_imx_probe_dt(struct imx_port *sport,
1878 		struct platform_device *pdev)
1879 {
1880 	struct device_node *np = pdev->dev.of_node;
1881 	const struct of_device_id *of_id =
1882 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1883 	int ret;
1884 
1885 	if (!np)
1886 		/* no device tree device */
1887 		return 1;
1888 
1889 	ret = of_alias_get_id(np, "serial");
1890 	if (ret < 0) {
1891 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1892 		return ret;
1893 	}
1894 	sport->port.line = ret;
1895 
1896 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1897 		sport->have_rtscts = 1;
1898 
1899 	if (of_get_property(np, "fsl,irda-mode", NULL))
1900 		sport->use_irda = 1;
1901 
1902 	if (of_get_property(np, "fsl,dte-mode", NULL))
1903 		sport->dte_mode = 1;
1904 
1905 	sport->devdata = of_id->data;
1906 
1907 	return 0;
1908 }
1909 #else
1910 static inline int serial_imx_probe_dt(struct imx_port *sport,
1911 		struct platform_device *pdev)
1912 {
1913 	return 1;
1914 }
1915 #endif
1916 
1917 static void serial_imx_probe_pdata(struct imx_port *sport,
1918 		struct platform_device *pdev)
1919 {
1920 	struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1921 
1922 	sport->port.line = pdev->id;
1923 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1924 
1925 	if (!pdata)
1926 		return;
1927 
1928 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1929 		sport->have_rtscts = 1;
1930 
1931 	if (pdata->flags & IMXUART_IRDA)
1932 		sport->use_irda = 1;
1933 }
1934 
1935 static int serial_imx_probe(struct platform_device *pdev)
1936 {
1937 	struct imx_port *sport;
1938 	struct imxuart_platform_data *pdata;
1939 	void __iomem *base;
1940 	int ret = 0;
1941 	struct resource *res;
1942 
1943 	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1944 	if (!sport)
1945 		return -ENOMEM;
1946 
1947 	ret = serial_imx_probe_dt(sport, pdev);
1948 	if (ret > 0)
1949 		serial_imx_probe_pdata(sport, pdev);
1950 	else if (ret < 0)
1951 		return ret;
1952 
1953 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1954 	if (!res)
1955 		return -ENODEV;
1956 
1957 	base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE);
1958 	if (!base)
1959 		return -ENOMEM;
1960 
1961 	sport->port.dev = &pdev->dev;
1962 	sport->port.mapbase = res->start;
1963 	sport->port.membase = base;
1964 	sport->port.type = PORT_IMX,
1965 	sport->port.iotype = UPIO_MEM;
1966 	sport->port.irq = platform_get_irq(pdev, 0);
1967 	sport->rxirq = platform_get_irq(pdev, 0);
1968 	sport->txirq = platform_get_irq(pdev, 1);
1969 	sport->rtsirq = platform_get_irq(pdev, 2);
1970 	sport->port.fifosize = 32;
1971 	sport->port.ops = &imx_pops;
1972 	sport->port.flags = UPF_BOOT_AUTOCONF;
1973 	init_timer(&sport->timer);
1974 	sport->timer.function = imx_timeout;
1975 	sport->timer.data     = (unsigned long)sport;
1976 
1977 	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1978 	if (IS_ERR(sport->clk_ipg)) {
1979 		ret = PTR_ERR(sport->clk_ipg);
1980 		dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1981 		return ret;
1982 	}
1983 
1984 	sport->clk_per = devm_clk_get(&pdev->dev, "per");
1985 	if (IS_ERR(sport->clk_per)) {
1986 		ret = PTR_ERR(sport->clk_per);
1987 		dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1988 		return ret;
1989 	}
1990 
1991 	sport->port.uartclk = clk_get_rate(sport->clk_per);
1992 
1993 	imx_ports[sport->port.line] = sport;
1994 
1995 	pdata = dev_get_platdata(&pdev->dev);
1996 	if (pdata && pdata->init) {
1997 		ret = pdata->init(pdev);
1998 		if (ret)
1999 			return ret;
2000 	}
2001 
2002 	ret = uart_add_one_port(&imx_reg, &sport->port);
2003 	if (ret)
2004 		goto deinit;
2005 	platform_set_drvdata(pdev, sport);
2006 
2007 	return 0;
2008 deinit:
2009 	if (pdata && pdata->exit)
2010 		pdata->exit(pdev);
2011 	return ret;
2012 }
2013 
2014 static int serial_imx_remove(struct platform_device *pdev)
2015 {
2016 	struct imxuart_platform_data *pdata;
2017 	struct imx_port *sport = platform_get_drvdata(pdev);
2018 
2019 	pdata = dev_get_platdata(&pdev->dev);
2020 
2021 	uart_remove_one_port(&imx_reg, &sport->port);
2022 
2023 	if (pdata && pdata->exit)
2024 		pdata->exit(pdev);
2025 
2026 	return 0;
2027 }
2028 
2029 static struct platform_driver serial_imx_driver = {
2030 	.probe		= serial_imx_probe,
2031 	.remove		= serial_imx_remove,
2032 
2033 	.suspend	= serial_imx_suspend,
2034 	.resume		= serial_imx_resume,
2035 	.id_table	= imx_uart_devtype,
2036 	.driver		= {
2037 		.name	= "imx-uart",
2038 		.owner	= THIS_MODULE,
2039 		.of_match_table = imx_uart_dt_ids,
2040 	},
2041 };
2042 
2043 static int __init imx_serial_init(void)
2044 {
2045 	int ret;
2046 
2047 	pr_info("Serial: IMX driver\n");
2048 
2049 	ret = uart_register_driver(&imx_reg);
2050 	if (ret)
2051 		return ret;
2052 
2053 	ret = platform_driver_register(&serial_imx_driver);
2054 	if (ret != 0)
2055 		uart_unregister_driver(&imx_reg);
2056 
2057 	return ret;
2058 }
2059 
2060 static void __exit imx_serial_exit(void)
2061 {
2062 	platform_driver_unregister(&serial_imx_driver);
2063 	uart_unregister_driver(&imx_reg);
2064 }
2065 
2066 module_init(imx_serial_init);
2067 module_exit(imx_serial_exit);
2068 
2069 MODULE_AUTHOR("Sascha Hauer");
2070 MODULE_DESCRIPTION("IMX generic serial port driver");
2071 MODULE_LICENSE("GPL");
2072 MODULE_ALIAS("platform:imx-uart");
2073