xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * drivers/serial/sh-sci.c
3  *
4  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
5  *
6  *  Copyright (C) 2002 - 2011  Paul Mundt
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  *
18  * This file is subject to the terms and conditions of the GNU General Public
19  * License.  See the file "COPYING" in the main directory of this archive
20  * for more details.
21  */
22 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
23 #define SUPPORT_SYSRQ
24 #endif
25 
26 #undef DEBUG
27 
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/timer.h>
31 #include <linux/interrupt.h>
32 #include <linux/tty.h>
33 #include <linux/tty_flip.h>
34 #include <linux/serial.h>
35 #include <linux/major.h>
36 #include <linux/string.h>
37 #include <linux/sysrq.h>
38 #include <linux/ioport.h>
39 #include <linux/mm.h>
40 #include <linux/init.h>
41 #include <linux/delay.h>
42 #include <linux/console.h>
43 #include <linux/platform_device.h>
44 #include <linux/serial_sci.h>
45 #include <linux/notifier.h>
46 #include <linux/cpufreq.h>
47 #include <linux/clk.h>
48 #include <linux/ctype.h>
49 #include <linux/err.h>
50 #include <linux/list.h>
51 #include <linux/dmaengine.h>
52 #include <linux/scatterlist.h>
53 #include <linux/slab.h>
54 
55 #ifdef CONFIG_SUPERH
56 #include <asm/sh_bios.h>
57 #endif
58 
59 #ifdef CONFIG_H8300
60 #include <asm/gpio.h>
61 #endif
62 
63 #include "sh-sci.h"
64 
65 struct sci_port {
66 	struct uart_port	port;
67 
68 	/* Port type */
69 	unsigned int		type;
70 
71 	/* Port IRQs: ERI, RXI, TXI, BRI (optional) */
72 	unsigned int		irqs[SCIx_NR_IRQS];
73 
74 	/* Port enable callback */
75 	void			(*enable)(struct uart_port *port);
76 
77 	/* Port disable callback */
78 	void			(*disable)(struct uart_port *port);
79 
80 	/* Break timer */
81 	struct timer_list	break_timer;
82 	int			break_flag;
83 
84 	/* SCSCR initialization */
85 	unsigned int		scscr;
86 
87 	/* SCBRR calculation algo */
88 	unsigned int		scbrr_algo_id;
89 
90 	/* Interface clock */
91 	struct clk		*iclk;
92 	/* Function clock */
93 	struct clk		*fclk;
94 
95 	struct list_head	node;
96 
97 	struct dma_chan			*chan_tx;
98 	struct dma_chan			*chan_rx;
99 
100 #ifdef CONFIG_SERIAL_SH_SCI_DMA
101 	struct device			*dma_dev;
102 	unsigned int			slave_tx;
103 	unsigned int			slave_rx;
104 	struct dma_async_tx_descriptor	*desc_tx;
105 	struct dma_async_tx_descriptor	*desc_rx[2];
106 	dma_cookie_t			cookie_tx;
107 	dma_cookie_t			cookie_rx[2];
108 	dma_cookie_t			active_rx;
109 	struct scatterlist		sg_tx;
110 	unsigned int			sg_len_tx;
111 	struct scatterlist		sg_rx[2];
112 	size_t				buf_len_rx;
113 	struct sh_dmae_slave		param_tx;
114 	struct sh_dmae_slave		param_rx;
115 	struct work_struct		work_tx;
116 	struct work_struct		work_rx;
117 	struct timer_list		rx_timer;
118 	unsigned int			rx_timeout;
119 #endif
120 };
121 
122 struct sh_sci_priv {
123 	spinlock_t lock;
124 	struct list_head ports;
125 	struct notifier_block clk_nb;
126 };
127 
128 /* Function prototypes */
129 static void sci_stop_tx(struct uart_port *port);
130 
131 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
132 
133 static struct sci_port sci_ports[SCI_NPORTS];
134 static struct uart_driver sci_uart_driver;
135 
136 static inline struct sci_port *
137 to_sci_port(struct uart_port *uart)
138 {
139 	return container_of(uart, struct sci_port, port);
140 }
141 
142 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
143 
144 #ifdef CONFIG_CONSOLE_POLL
145 static inline void handle_error(struct uart_port *port)
146 {
147 	/* Clear error flags */
148 	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
149 }
150 
151 static int sci_poll_get_char(struct uart_port *port)
152 {
153 	unsigned short status;
154 	int c;
155 
156 	do {
157 		status = sci_in(port, SCxSR);
158 		if (status & SCxSR_ERRORS(port)) {
159 			handle_error(port);
160 			continue;
161 		}
162 		break;
163 	} while (1);
164 
165 	if (!(status & SCxSR_RDxF(port)))
166 		return NO_POLL_CHAR;
167 
168 	c = sci_in(port, SCxRDR);
169 
170 	/* Dummy read */
171 	sci_in(port, SCxSR);
172 	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
173 
174 	return c;
175 }
176 #endif
177 
178 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
179 {
180 	unsigned short status;
181 
182 	do {
183 		status = sci_in(port, SCxSR);
184 	} while (!(status & SCxSR_TDxE(port)));
185 
186 	sci_out(port, SCxTDR, c);
187 	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
188 }
189 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
190 
191 #if defined(__H8300H__) || defined(__H8300S__)
192 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
193 {
194 	int ch = (port->mapbase - SMR0) >> 3;
195 
196 	/* set DDR regs */
197 	H8300_GPIO_DDR(h8300_sci_pins[ch].port,
198 		       h8300_sci_pins[ch].rx,
199 		       H8300_GPIO_INPUT);
200 	H8300_GPIO_DDR(h8300_sci_pins[ch].port,
201 		       h8300_sci_pins[ch].tx,
202 		       H8300_GPIO_OUTPUT);
203 
204 	/* tx mark output*/
205 	H8300_SCI_DR(ch) |= h8300_sci_pins[ch].tx;
206 }
207 #elif defined(CONFIG_CPU_SUBTYPE_SH7710) || defined(CONFIG_CPU_SUBTYPE_SH7712)
208 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
209 {
210 	if (port->mapbase == 0xA4400000) {
211 		__raw_writew(__raw_readw(PACR) & 0xffc0, PACR);
212 		__raw_writew(__raw_readw(PBCR) & 0x0fff, PBCR);
213 	} else if (port->mapbase == 0xA4410000)
214 		__raw_writew(__raw_readw(PBCR) & 0xf003, PBCR);
215 }
216 #elif defined(CONFIG_CPU_SUBTYPE_SH7720) || defined(CONFIG_CPU_SUBTYPE_SH7721)
217 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
218 {
219 	unsigned short data;
220 
221 	if (cflag & CRTSCTS) {
222 		/* enable RTS/CTS */
223 		if (port->mapbase == 0xa4430000) { /* SCIF0 */
224 			/* Clear PTCR bit 9-2; enable all scif pins but sck */
225 			data = __raw_readw(PORT_PTCR);
226 			__raw_writew((data & 0xfc03), PORT_PTCR);
227 		} else if (port->mapbase == 0xa4438000) { /* SCIF1 */
228 			/* Clear PVCR bit 9-2 */
229 			data = __raw_readw(PORT_PVCR);
230 			__raw_writew((data & 0xfc03), PORT_PVCR);
231 		}
232 	} else {
233 		if (port->mapbase == 0xa4430000) { /* SCIF0 */
234 			/* Clear PTCR bit 5-2; enable only tx and rx  */
235 			data = __raw_readw(PORT_PTCR);
236 			__raw_writew((data & 0xffc3), PORT_PTCR);
237 		} else if (port->mapbase == 0xa4438000) { /* SCIF1 */
238 			/* Clear PVCR bit 5-2 */
239 			data = __raw_readw(PORT_PVCR);
240 			__raw_writew((data & 0xffc3), PORT_PVCR);
241 		}
242 	}
243 }
244 #elif defined(CONFIG_CPU_SH3)
245 /* For SH7705, SH7706, SH7707, SH7709, SH7709A, SH7729 */
246 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
247 {
248 	unsigned short data;
249 
250 	/* We need to set SCPCR to enable RTS/CTS */
251 	data = __raw_readw(SCPCR);
252 	/* Clear out SCP7MD1,0, SCP6MD1,0, SCP4MD1,0*/
253 	__raw_writew(data & 0x0fcf, SCPCR);
254 
255 	if (!(cflag & CRTSCTS)) {
256 		/* We need to set SCPCR to enable RTS/CTS */
257 		data = __raw_readw(SCPCR);
258 		/* Clear out SCP7MD1,0, SCP4MD1,0,
259 		   Set SCP6MD1,0 = {01} (output)  */
260 		__raw_writew((data & 0x0fcf) | 0x1000, SCPCR);
261 
262 		data = __raw_readb(SCPDR);
263 		/* Set /RTS2 (bit6) = 0 */
264 		__raw_writeb(data & 0xbf, SCPDR);
265 	}
266 }
267 #elif defined(CONFIG_CPU_SUBTYPE_SH7722)
268 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
269 {
270 	unsigned short data;
271 
272 	if (port->mapbase == 0xffe00000) {
273 		data = __raw_readw(PSCR);
274 		data &= ~0x03cf;
275 		if (!(cflag & CRTSCTS))
276 			data |= 0x0340;
277 
278 		__raw_writew(data, PSCR);
279 	}
280 }
281 #elif defined(CONFIG_CPU_SUBTYPE_SH7757) || \
282       defined(CONFIG_CPU_SUBTYPE_SH7763) || \
283       defined(CONFIG_CPU_SUBTYPE_SH7780) || \
284       defined(CONFIG_CPU_SUBTYPE_SH7785) || \
285       defined(CONFIG_CPU_SUBTYPE_SH7786) || \
286       defined(CONFIG_CPU_SUBTYPE_SHX3)
287 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
288 {
289 	if (!(cflag & CRTSCTS))
290 		__raw_writew(0x0080, SCSPTR0); /* Set RTS = 1 */
291 }
292 #elif defined(CONFIG_CPU_SH4) && !defined(CONFIG_CPU_SH4A)
293 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
294 {
295 	if (!(cflag & CRTSCTS))
296 		__raw_writew(0x0080, SCSPTR2); /* Set RTS = 1 */
297 }
298 #else
299 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
300 {
301 	/* Nothing to do */
302 }
303 #endif
304 
305 #if defined(CONFIG_CPU_SUBTYPE_SH7760) || \
306     defined(CONFIG_CPU_SUBTYPE_SH7780) || \
307     defined(CONFIG_CPU_SUBTYPE_SH7785) || \
308     defined(CONFIG_CPU_SUBTYPE_SH7786)
309 static int scif_txfill(struct uart_port *port)
310 {
311 	return sci_in(port, SCTFDR) & 0xff;
312 }
313 
314 static int scif_txroom(struct uart_port *port)
315 {
316 	return SCIF_TXROOM_MAX - scif_txfill(port);
317 }
318 
319 static int scif_rxfill(struct uart_port *port)
320 {
321 	return sci_in(port, SCRFDR) & 0xff;
322 }
323 #elif defined(CONFIG_CPU_SUBTYPE_SH7763)
324 static int scif_txfill(struct uart_port *port)
325 {
326 	if (port->mapbase == 0xffe00000 ||
327 	    port->mapbase == 0xffe08000)
328 		/* SCIF0/1*/
329 		return sci_in(port, SCTFDR) & 0xff;
330 	else
331 		/* SCIF2 */
332 		return sci_in(port, SCFDR) >> 8;
333 }
334 
335 static int scif_txroom(struct uart_port *port)
336 {
337 	if (port->mapbase == 0xffe00000 ||
338 	    port->mapbase == 0xffe08000)
339 		/* SCIF0/1*/
340 		return SCIF_TXROOM_MAX - scif_txfill(port);
341 	else
342 		/* SCIF2 */
343 		return SCIF2_TXROOM_MAX - scif_txfill(port);
344 }
345 
346 static int scif_rxfill(struct uart_port *port)
347 {
348 	if ((port->mapbase == 0xffe00000) ||
349 	    (port->mapbase == 0xffe08000)) {
350 		/* SCIF0/1*/
351 		return sci_in(port, SCRFDR) & 0xff;
352 	} else {
353 		/* SCIF2 */
354 		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
355 	}
356 }
357 #elif defined(CONFIG_ARCH_SH7372)
358 static int scif_txfill(struct uart_port *port)
359 {
360 	if (port->type == PORT_SCIFA)
361 		return sci_in(port, SCFDR) >> 8;
362 	else
363 		return sci_in(port, SCTFDR);
364 }
365 
366 static int scif_txroom(struct uart_port *port)
367 {
368 	return port->fifosize - scif_txfill(port);
369 }
370 
371 static int scif_rxfill(struct uart_port *port)
372 {
373 	if (port->type == PORT_SCIFA)
374 		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
375 	else
376 		return sci_in(port, SCRFDR);
377 }
378 #else
379 static int scif_txfill(struct uart_port *port)
380 {
381 	return sci_in(port, SCFDR) >> 8;
382 }
383 
384 static int scif_txroom(struct uart_port *port)
385 {
386 	return SCIF_TXROOM_MAX - scif_txfill(port);
387 }
388 
389 static int scif_rxfill(struct uart_port *port)
390 {
391 	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
392 }
393 #endif
394 
395 static int sci_txfill(struct uart_port *port)
396 {
397 	return !(sci_in(port, SCxSR) & SCI_TDRE);
398 }
399 
400 static int sci_txroom(struct uart_port *port)
401 {
402 	return !sci_txfill(port);
403 }
404 
405 static int sci_rxfill(struct uart_port *port)
406 {
407 	return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
408 }
409 
410 /* ********************************************************************** *
411  *                   the interrupt related routines                       *
412  * ********************************************************************** */
413 
414 static void sci_transmit_chars(struct uart_port *port)
415 {
416 	struct circ_buf *xmit = &port->state->xmit;
417 	unsigned int stopped = uart_tx_stopped(port);
418 	unsigned short status;
419 	unsigned short ctrl;
420 	int count;
421 
422 	status = sci_in(port, SCxSR);
423 	if (!(status & SCxSR_TDxE(port))) {
424 		ctrl = sci_in(port, SCSCR);
425 		if (uart_circ_empty(xmit))
426 			ctrl &= ~SCSCR_TIE;
427 		else
428 			ctrl |= SCSCR_TIE;
429 		sci_out(port, SCSCR, ctrl);
430 		return;
431 	}
432 
433 	if (port->type == PORT_SCI)
434 		count = sci_txroom(port);
435 	else
436 		count = scif_txroom(port);
437 
438 	do {
439 		unsigned char c;
440 
441 		if (port->x_char) {
442 			c = port->x_char;
443 			port->x_char = 0;
444 		} else if (!uart_circ_empty(xmit) && !stopped) {
445 			c = xmit->buf[xmit->tail];
446 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
447 		} else {
448 			break;
449 		}
450 
451 		sci_out(port, SCxTDR, c);
452 
453 		port->icount.tx++;
454 	} while (--count > 0);
455 
456 	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
457 
458 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
459 		uart_write_wakeup(port);
460 	if (uart_circ_empty(xmit)) {
461 		sci_stop_tx(port);
462 	} else {
463 		ctrl = sci_in(port, SCSCR);
464 
465 		if (port->type != PORT_SCI) {
466 			sci_in(port, SCxSR); /* Dummy read */
467 			sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
468 		}
469 
470 		ctrl |= SCSCR_TIE;
471 		sci_out(port, SCSCR, ctrl);
472 	}
473 }
474 
475 /* On SH3, SCIF may read end-of-break as a space->mark char */
476 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
477 
478 static inline void sci_receive_chars(struct uart_port *port)
479 {
480 	struct sci_port *sci_port = to_sci_port(port);
481 	struct tty_struct *tty = port->state->port.tty;
482 	int i, count, copied = 0;
483 	unsigned short status;
484 	unsigned char flag;
485 
486 	status = sci_in(port, SCxSR);
487 	if (!(status & SCxSR_RDxF(port)))
488 		return;
489 
490 	while (1) {
491 		if (port->type == PORT_SCI)
492 			count = sci_rxfill(port);
493 		else
494 			count = scif_rxfill(port);
495 
496 		/* Don't copy more bytes than there is room for in the buffer */
497 		count = tty_buffer_request_room(tty, count);
498 
499 		/* If for any reason we can't copy more data, we're done! */
500 		if (count == 0)
501 			break;
502 
503 		if (port->type == PORT_SCI) {
504 			char c = sci_in(port, SCxRDR);
505 			if (uart_handle_sysrq_char(port, c) ||
506 			    sci_port->break_flag)
507 				count = 0;
508 			else
509 				tty_insert_flip_char(tty, c, TTY_NORMAL);
510 		} else {
511 			for (i = 0; i < count; i++) {
512 				char c = sci_in(port, SCxRDR);
513 				status = sci_in(port, SCxSR);
514 #if defined(CONFIG_CPU_SH3)
515 				/* Skip "chars" during break */
516 				if (sci_port->break_flag) {
517 					if ((c == 0) &&
518 					    (status & SCxSR_FER(port))) {
519 						count--; i--;
520 						continue;
521 					}
522 
523 					/* Nonzero => end-of-break */
524 					dev_dbg(port->dev, "debounce<%02x>\n", c);
525 					sci_port->break_flag = 0;
526 
527 					if (STEPFN(c)) {
528 						count--; i--;
529 						continue;
530 					}
531 				}
532 #endif /* CONFIG_CPU_SH3 */
533 				if (uart_handle_sysrq_char(port, c)) {
534 					count--; i--;
535 					continue;
536 				}
537 
538 				/* Store data and status */
539 				if (status & SCxSR_FER(port)) {
540 					flag = TTY_FRAME;
541 					dev_notice(port->dev, "frame error\n");
542 				} else if (status & SCxSR_PER(port)) {
543 					flag = TTY_PARITY;
544 					dev_notice(port->dev, "parity error\n");
545 				} else
546 					flag = TTY_NORMAL;
547 
548 				tty_insert_flip_char(tty, c, flag);
549 			}
550 		}
551 
552 		sci_in(port, SCxSR); /* dummy read */
553 		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
554 
555 		copied += count;
556 		port->icount.rx += count;
557 	}
558 
559 	if (copied) {
560 		/* Tell the rest of the system the news. New characters! */
561 		tty_flip_buffer_push(tty);
562 	} else {
563 		sci_in(port, SCxSR); /* dummy read */
564 		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
565 	}
566 }
567 
568 #define SCI_BREAK_JIFFIES (HZ/20)
569 /* The sci generates interrupts during the break,
570  * 1 per millisecond or so during the break period, for 9600 baud.
571  * So dont bother disabling interrupts.
572  * But dont want more than 1 break event.
573  * Use a kernel timer to periodically poll the rx line until
574  * the break is finished.
575  */
576 static void sci_schedule_break_timer(struct sci_port *port)
577 {
578 	port->break_timer.expires = jiffies + SCI_BREAK_JIFFIES;
579 	add_timer(&port->break_timer);
580 }
581 /* Ensure that two consecutive samples find the break over. */
582 static void sci_break_timer(unsigned long data)
583 {
584 	struct sci_port *port = (struct sci_port *)data;
585 
586 	if (sci_rxd_in(&port->port) == 0) {
587 		port->break_flag = 1;
588 		sci_schedule_break_timer(port);
589 	} else if (port->break_flag == 1) {
590 		/* break is over. */
591 		port->break_flag = 2;
592 		sci_schedule_break_timer(port);
593 	} else
594 		port->break_flag = 0;
595 }
596 
597 static inline int sci_handle_errors(struct uart_port *port)
598 {
599 	int copied = 0;
600 	unsigned short status = sci_in(port, SCxSR);
601 	struct tty_struct *tty = port->state->port.tty;
602 
603 	if (status & SCxSR_ORER(port)) {
604 		/* overrun error */
605 		if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
606 			copied++;
607 
608 		dev_notice(port->dev, "overrun error");
609 	}
610 
611 	if (status & SCxSR_FER(port)) {
612 		if (sci_rxd_in(port) == 0) {
613 			/* Notify of BREAK */
614 			struct sci_port *sci_port = to_sci_port(port);
615 
616 			if (!sci_port->break_flag) {
617 				sci_port->break_flag = 1;
618 				sci_schedule_break_timer(sci_port);
619 
620 				/* Do sysrq handling. */
621 				if (uart_handle_break(port))
622 					return 0;
623 
624 				dev_dbg(port->dev, "BREAK detected\n");
625 
626 				if (tty_insert_flip_char(tty, 0, TTY_BREAK))
627 					copied++;
628 			}
629 
630 		} else {
631 			/* frame error */
632 			if (tty_insert_flip_char(tty, 0, TTY_FRAME))
633 				copied++;
634 
635 			dev_notice(port->dev, "frame error\n");
636 		}
637 	}
638 
639 	if (status & SCxSR_PER(port)) {
640 		/* parity error */
641 		if (tty_insert_flip_char(tty, 0, TTY_PARITY))
642 			copied++;
643 
644 		dev_notice(port->dev, "parity error");
645 	}
646 
647 	if (copied)
648 		tty_flip_buffer_push(tty);
649 
650 	return copied;
651 }
652 
653 static inline int sci_handle_fifo_overrun(struct uart_port *port)
654 {
655 	struct tty_struct *tty = port->state->port.tty;
656 	int copied = 0;
657 
658 	if (port->type != PORT_SCIF)
659 		return 0;
660 
661 	if ((sci_in(port, SCLSR) & SCIF_ORER) != 0) {
662 		sci_out(port, SCLSR, 0);
663 
664 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
665 		tty_flip_buffer_push(tty);
666 
667 		dev_notice(port->dev, "overrun error\n");
668 		copied++;
669 	}
670 
671 	return copied;
672 }
673 
674 static inline int sci_handle_breaks(struct uart_port *port)
675 {
676 	int copied = 0;
677 	unsigned short status = sci_in(port, SCxSR);
678 	struct tty_struct *tty = port->state->port.tty;
679 	struct sci_port *s = to_sci_port(port);
680 
681 	if (uart_handle_break(port))
682 		return 0;
683 
684 	if (!s->break_flag && status & SCxSR_BRK(port)) {
685 #if defined(CONFIG_CPU_SH3)
686 		/* Debounce break */
687 		s->break_flag = 1;
688 #endif
689 		/* Notify of BREAK */
690 		if (tty_insert_flip_char(tty, 0, TTY_BREAK))
691 			copied++;
692 
693 		dev_dbg(port->dev, "BREAK detected\n");
694 	}
695 
696 	if (copied)
697 		tty_flip_buffer_push(tty);
698 
699 	copied += sci_handle_fifo_overrun(port);
700 
701 	return copied;
702 }
703 
704 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
705 {
706 #ifdef CONFIG_SERIAL_SH_SCI_DMA
707 	struct uart_port *port = ptr;
708 	struct sci_port *s = to_sci_port(port);
709 
710 	if (s->chan_rx) {
711 		u16 scr = sci_in(port, SCSCR);
712 		u16 ssr = sci_in(port, SCxSR);
713 
714 		/* Disable future Rx interrupts */
715 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
716 			disable_irq_nosync(irq);
717 			scr |= 0x4000;
718 		} else {
719 			scr &= ~SCSCR_RIE;
720 		}
721 		sci_out(port, SCSCR, scr);
722 		/* Clear current interrupt */
723 		sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
724 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
725 			jiffies, s->rx_timeout);
726 		mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
727 
728 		return IRQ_HANDLED;
729 	}
730 #endif
731 
732 	/* I think sci_receive_chars has to be called irrespective
733 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
734 	 * to be disabled?
735 	 */
736 	sci_receive_chars(ptr);
737 
738 	return IRQ_HANDLED;
739 }
740 
741 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
742 {
743 	struct uart_port *port = ptr;
744 	unsigned long flags;
745 
746 	spin_lock_irqsave(&port->lock, flags);
747 	sci_transmit_chars(port);
748 	spin_unlock_irqrestore(&port->lock, flags);
749 
750 	return IRQ_HANDLED;
751 }
752 
753 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
754 {
755 	struct uart_port *port = ptr;
756 
757 	/* Handle errors */
758 	if (port->type == PORT_SCI) {
759 		if (sci_handle_errors(port)) {
760 			/* discard character in rx buffer */
761 			sci_in(port, SCxSR);
762 			sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
763 		}
764 	} else {
765 		sci_handle_fifo_overrun(port);
766 		sci_rx_interrupt(irq, ptr);
767 	}
768 
769 	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
770 
771 	/* Kick the transmission */
772 	sci_tx_interrupt(irq, ptr);
773 
774 	return IRQ_HANDLED;
775 }
776 
777 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
778 {
779 	struct uart_port *port = ptr;
780 
781 	/* Handle BREAKs */
782 	sci_handle_breaks(port);
783 	sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
784 
785 	return IRQ_HANDLED;
786 }
787 
788 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
789 {
790 	/*
791 	 * Not all ports (such as SCIFA) will support REIE. Rather than
792 	 * special-casing the port type, we check the port initialization
793 	 * IRQ enable mask to see whether the IRQ is desired at all. If
794 	 * it's unset, it's logically inferred that there's no point in
795 	 * testing for it.
796 	 */
797 	return SCSCR_RIE | (to_sci_port(port)->scscr & SCSCR_REIE);
798 }
799 
800 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
801 {
802 	unsigned short ssr_status, scr_status, err_enabled;
803 	struct uart_port *port = ptr;
804 	struct sci_port *s = to_sci_port(port);
805 	irqreturn_t ret = IRQ_NONE;
806 
807 	ssr_status = sci_in(port, SCxSR);
808 	scr_status = sci_in(port, SCSCR);
809 	err_enabled = scr_status & port_rx_irq_mask(port);
810 
811 	/* Tx Interrupt */
812 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
813 	    !s->chan_tx)
814 		ret = sci_tx_interrupt(irq, ptr);
815 
816 	/*
817 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
818 	 * DR flags
819 	 */
820 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
821 	    (scr_status & SCSCR_RIE))
822 		ret = sci_rx_interrupt(irq, ptr);
823 
824 	/* Error Interrupt */
825 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
826 		ret = sci_er_interrupt(irq, ptr);
827 
828 	/* Break Interrupt */
829 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
830 		ret = sci_br_interrupt(irq, ptr);
831 
832 	return ret;
833 }
834 
835 /*
836  * Here we define a transistion notifier so that we can update all of our
837  * ports' baud rate when the peripheral clock changes.
838  */
839 static int sci_notifier(struct notifier_block *self,
840 			unsigned long phase, void *p)
841 {
842 	struct sh_sci_priv *priv = container_of(self,
843 						struct sh_sci_priv, clk_nb);
844 	struct sci_port *sci_port;
845 	unsigned long flags;
846 
847 	if ((phase == CPUFREQ_POSTCHANGE) ||
848 	    (phase == CPUFREQ_RESUMECHANGE)) {
849 		spin_lock_irqsave(&priv->lock, flags);
850 		list_for_each_entry(sci_port, &priv->ports, node)
851 			sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
852 		spin_unlock_irqrestore(&priv->lock, flags);
853 	}
854 
855 	return NOTIFY_OK;
856 }
857 
858 static void sci_clk_enable(struct uart_port *port)
859 {
860 	struct sci_port *sci_port = to_sci_port(port);
861 
862 	clk_enable(sci_port->iclk);
863 	sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
864 	clk_enable(sci_port->fclk);
865 }
866 
867 static void sci_clk_disable(struct uart_port *port)
868 {
869 	struct sci_port *sci_port = to_sci_port(port);
870 
871 	clk_disable(sci_port->fclk);
872 	clk_disable(sci_port->iclk);
873 }
874 
875 static int sci_request_irq(struct sci_port *port)
876 {
877 	int i;
878 	irqreturn_t (*handlers[4])(int irq, void *ptr) = {
879 		sci_er_interrupt, sci_rx_interrupt, sci_tx_interrupt,
880 		sci_br_interrupt,
881 	};
882 	const char *desc[] = { "SCI Receive Error", "SCI Receive Data Full",
883 			       "SCI Transmit Data Empty", "SCI Break" };
884 
885 	if (port->irqs[0] == port->irqs[1]) {
886 		if (unlikely(!port->irqs[0]))
887 			return -ENODEV;
888 
889 		if (request_irq(port->irqs[0], sci_mpxed_interrupt,
890 				IRQF_DISABLED, "sci", port)) {
891 			dev_err(port->port.dev, "Can't allocate IRQ\n");
892 			return -ENODEV;
893 		}
894 	} else {
895 		for (i = 0; i < ARRAY_SIZE(handlers); i++) {
896 			if (unlikely(!port->irqs[i]))
897 				continue;
898 
899 			if (request_irq(port->irqs[i], handlers[i],
900 					IRQF_DISABLED, desc[i], port)) {
901 				dev_err(port->port.dev, "Can't allocate IRQ\n");
902 				return -ENODEV;
903 			}
904 		}
905 	}
906 
907 	return 0;
908 }
909 
910 static void sci_free_irq(struct sci_port *port)
911 {
912 	int i;
913 
914 	if (port->irqs[0] == port->irqs[1])
915 		free_irq(port->irqs[0], port);
916 	else {
917 		for (i = 0; i < ARRAY_SIZE(port->irqs); i++) {
918 			if (!port->irqs[i])
919 				continue;
920 
921 			free_irq(port->irqs[i], port);
922 		}
923 	}
924 }
925 
926 static unsigned int sci_tx_empty(struct uart_port *port)
927 {
928 	unsigned short status = sci_in(port, SCxSR);
929 	unsigned short in_tx_fifo = scif_txfill(port);
930 
931 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
932 }
933 
934 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
935 {
936 	/* This routine is used for seting signals of: DTR, DCD, CTS/RTS */
937 	/* We use SCIF's hardware for CTS/RTS, so don't need any for that. */
938 	/* If you have signals for DTR and DCD, please implement here. */
939 }
940 
941 static unsigned int sci_get_mctrl(struct uart_port *port)
942 {
943 	/* This routine is used for getting signals of: DTR, DCD, DSR, RI,
944 	   and CTS/RTS */
945 
946 	return TIOCM_DTR | TIOCM_RTS | TIOCM_DSR;
947 }
948 
949 #ifdef CONFIG_SERIAL_SH_SCI_DMA
950 static void sci_dma_tx_complete(void *arg)
951 {
952 	struct sci_port *s = arg;
953 	struct uart_port *port = &s->port;
954 	struct circ_buf *xmit = &port->state->xmit;
955 	unsigned long flags;
956 
957 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
958 
959 	spin_lock_irqsave(&port->lock, flags);
960 
961 	xmit->tail += sg_dma_len(&s->sg_tx);
962 	xmit->tail &= UART_XMIT_SIZE - 1;
963 
964 	port->icount.tx += sg_dma_len(&s->sg_tx);
965 
966 	async_tx_ack(s->desc_tx);
967 	s->cookie_tx = -EINVAL;
968 	s->desc_tx = NULL;
969 
970 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
971 		uart_write_wakeup(port);
972 
973 	if (!uart_circ_empty(xmit)) {
974 		schedule_work(&s->work_tx);
975 	} else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
976 		u16 ctrl = sci_in(port, SCSCR);
977 		sci_out(port, SCSCR, ctrl & ~SCSCR_TIE);
978 	}
979 
980 	spin_unlock_irqrestore(&port->lock, flags);
981 }
982 
983 /* Locking: called with port lock held */
984 static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,
985 			   size_t count)
986 {
987 	struct uart_port *port = &s->port;
988 	int i, active, room;
989 
990 	room = tty_buffer_request_room(tty, count);
991 
992 	if (s->active_rx == s->cookie_rx[0]) {
993 		active = 0;
994 	} else if (s->active_rx == s->cookie_rx[1]) {
995 		active = 1;
996 	} else {
997 		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
998 		return 0;
999 	}
1000 
1001 	if (room < count)
1002 		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
1003 			 count - room);
1004 	if (!room)
1005 		return room;
1006 
1007 	for (i = 0; i < room; i++)
1008 		tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
1009 				     TTY_NORMAL);
1010 
1011 	port->icount.rx += room;
1012 
1013 	return room;
1014 }
1015 
1016 static void sci_dma_rx_complete(void *arg)
1017 {
1018 	struct sci_port *s = arg;
1019 	struct uart_port *port = &s->port;
1020 	struct tty_struct *tty = port->state->port.tty;
1021 	unsigned long flags;
1022 	int count;
1023 
1024 	dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
1025 
1026 	spin_lock_irqsave(&port->lock, flags);
1027 
1028 	count = sci_dma_rx_push(s, tty, s->buf_len_rx);
1029 
1030 	mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1031 
1032 	spin_unlock_irqrestore(&port->lock, flags);
1033 
1034 	if (count)
1035 		tty_flip_buffer_push(tty);
1036 
1037 	schedule_work(&s->work_rx);
1038 }
1039 
1040 static void sci_start_rx(struct uart_port *port);
1041 static void sci_start_tx(struct uart_port *port);
1042 
1043 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1044 {
1045 	struct dma_chan *chan = s->chan_rx;
1046 	struct uart_port *port = &s->port;
1047 
1048 	s->chan_rx = NULL;
1049 	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1050 	dma_release_channel(chan);
1051 	if (sg_dma_address(&s->sg_rx[0]))
1052 		dma_free_coherent(port->dev, s->buf_len_rx * 2,
1053 				  sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
1054 	if (enable_pio)
1055 		sci_start_rx(port);
1056 }
1057 
1058 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1059 {
1060 	struct dma_chan *chan = s->chan_tx;
1061 	struct uart_port *port = &s->port;
1062 
1063 	s->chan_tx = NULL;
1064 	s->cookie_tx = -EINVAL;
1065 	dma_release_channel(chan);
1066 	if (enable_pio)
1067 		sci_start_tx(port);
1068 }
1069 
1070 static void sci_submit_rx(struct sci_port *s)
1071 {
1072 	struct dma_chan *chan = s->chan_rx;
1073 	int i;
1074 
1075 	for (i = 0; i < 2; i++) {
1076 		struct scatterlist *sg = &s->sg_rx[i];
1077 		struct dma_async_tx_descriptor *desc;
1078 
1079 		desc = chan->device->device_prep_slave_sg(chan,
1080 			sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);
1081 
1082 		if (desc) {
1083 			s->desc_rx[i] = desc;
1084 			desc->callback = sci_dma_rx_complete;
1085 			desc->callback_param = s;
1086 			s->cookie_rx[i] = desc->tx_submit(desc);
1087 		}
1088 
1089 		if (!desc || s->cookie_rx[i] < 0) {
1090 			if (i) {
1091 				async_tx_ack(s->desc_rx[0]);
1092 				s->cookie_rx[0] = -EINVAL;
1093 			}
1094 			if (desc) {
1095 				async_tx_ack(desc);
1096 				s->cookie_rx[i] = -EINVAL;
1097 			}
1098 			dev_warn(s->port.dev,
1099 				 "failed to re-start DMA, using PIO\n");
1100 			sci_rx_dma_release(s, true);
1101 			return;
1102 		}
1103 		dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1104 			s->cookie_rx[i], i);
1105 	}
1106 
1107 	s->active_rx = s->cookie_rx[0];
1108 
1109 	dma_async_issue_pending(chan);
1110 }
1111 
1112 static void work_fn_rx(struct work_struct *work)
1113 {
1114 	struct sci_port *s = container_of(work, struct sci_port, work_rx);
1115 	struct uart_port *port = &s->port;
1116 	struct dma_async_tx_descriptor *desc;
1117 	int new;
1118 
1119 	if (s->active_rx == s->cookie_rx[0]) {
1120 		new = 0;
1121 	} else if (s->active_rx == s->cookie_rx[1]) {
1122 		new = 1;
1123 	} else {
1124 		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1125 		return;
1126 	}
1127 	desc = s->desc_rx[new];
1128 
1129 	if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
1130 	    DMA_SUCCESS) {
1131 		/* Handle incomplete DMA receive */
1132 		struct tty_struct *tty = port->state->port.tty;
1133 		struct dma_chan *chan = s->chan_rx;
1134 		struct sh_desc *sh_desc = container_of(desc, struct sh_desc,
1135 						       async_tx);
1136 		unsigned long flags;
1137 		int count;
1138 
1139 		chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
1140 		dev_dbg(port->dev, "Read %u bytes with cookie %d\n",
1141 			sh_desc->partial, sh_desc->cookie);
1142 
1143 		spin_lock_irqsave(&port->lock, flags);
1144 		count = sci_dma_rx_push(s, tty, sh_desc->partial);
1145 		spin_unlock_irqrestore(&port->lock, flags);
1146 
1147 		if (count)
1148 			tty_flip_buffer_push(tty);
1149 
1150 		sci_submit_rx(s);
1151 
1152 		return;
1153 	}
1154 
1155 	s->cookie_rx[new] = desc->tx_submit(desc);
1156 	if (s->cookie_rx[new] < 0) {
1157 		dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1158 		sci_rx_dma_release(s, true);
1159 		return;
1160 	}
1161 
1162 	s->active_rx = s->cookie_rx[!new];
1163 
1164 	dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
1165 		s->cookie_rx[new], new, s->active_rx);
1166 }
1167 
1168 static void work_fn_tx(struct work_struct *work)
1169 {
1170 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1171 	struct dma_async_tx_descriptor *desc;
1172 	struct dma_chan *chan = s->chan_tx;
1173 	struct uart_port *port = &s->port;
1174 	struct circ_buf *xmit = &port->state->xmit;
1175 	struct scatterlist *sg = &s->sg_tx;
1176 
1177 	/*
1178 	 * DMA is idle now.
1179 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1180 	 * offsets and lengths. Since it is a circular buffer, we have to
1181 	 * transmit till the end, and then the rest. Take the port lock to get a
1182 	 * consistent xmit buffer state.
1183 	 */
1184 	spin_lock_irq(&port->lock);
1185 	sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
1186 	sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
1187 		sg->offset;
1188 	sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1189 		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1190 	spin_unlock_irq(&port->lock);
1191 
1192 	BUG_ON(!sg_dma_len(sg));
1193 
1194 	desc = chan->device->device_prep_slave_sg(chan,
1195 			sg, s->sg_len_tx, DMA_TO_DEVICE,
1196 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1197 	if (!desc) {
1198 		/* switch to PIO */
1199 		sci_tx_dma_release(s, true);
1200 		return;
1201 	}
1202 
1203 	dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
1204 
1205 	spin_lock_irq(&port->lock);
1206 	s->desc_tx = desc;
1207 	desc->callback = sci_dma_tx_complete;
1208 	desc->callback_param = s;
1209 	spin_unlock_irq(&port->lock);
1210 	s->cookie_tx = desc->tx_submit(desc);
1211 	if (s->cookie_tx < 0) {
1212 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1213 		/* switch to PIO */
1214 		sci_tx_dma_release(s, true);
1215 		return;
1216 	}
1217 
1218 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,
1219 		xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1220 
1221 	dma_async_issue_pending(chan);
1222 }
1223 #endif
1224 
1225 static void sci_start_tx(struct uart_port *port)
1226 {
1227 	struct sci_port *s = to_sci_port(port);
1228 	unsigned short ctrl;
1229 
1230 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1231 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1232 		u16 new, scr = sci_in(port, SCSCR);
1233 		if (s->chan_tx)
1234 			new = scr | 0x8000;
1235 		else
1236 			new = scr & ~0x8000;
1237 		if (new != scr)
1238 			sci_out(port, SCSCR, new);
1239 	}
1240 
1241 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
1242 	    s->cookie_tx < 0)
1243 		schedule_work(&s->work_tx);
1244 #endif
1245 
1246 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1247 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
1248 		ctrl = sci_in(port, SCSCR);
1249 		sci_out(port, SCSCR, ctrl | SCSCR_TIE);
1250 	}
1251 }
1252 
1253 static void sci_stop_tx(struct uart_port *port)
1254 {
1255 	unsigned short ctrl;
1256 
1257 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
1258 	ctrl = sci_in(port, SCSCR);
1259 
1260 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1261 		ctrl &= ~0x8000;
1262 
1263 	ctrl &= ~SCSCR_TIE;
1264 
1265 	sci_out(port, SCSCR, ctrl);
1266 }
1267 
1268 static void sci_start_rx(struct uart_port *port)
1269 {
1270 	unsigned short ctrl;
1271 
1272 	ctrl = sci_in(port, SCSCR) | port_rx_irq_mask(port);
1273 
1274 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1275 		ctrl &= ~0x4000;
1276 
1277 	sci_out(port, SCSCR, ctrl);
1278 }
1279 
1280 static void sci_stop_rx(struct uart_port *port)
1281 {
1282 	unsigned short ctrl;
1283 
1284 	ctrl = sci_in(port, SCSCR);
1285 
1286 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1287 		ctrl &= ~0x4000;
1288 
1289 	ctrl &= ~port_rx_irq_mask(port);
1290 
1291 	sci_out(port, SCSCR, ctrl);
1292 }
1293 
1294 static void sci_enable_ms(struct uart_port *port)
1295 {
1296 	/* Nothing here yet .. */
1297 }
1298 
1299 static void sci_break_ctl(struct uart_port *port, int break_state)
1300 {
1301 	/* Nothing here yet .. */
1302 }
1303 
1304 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1305 static bool filter(struct dma_chan *chan, void *slave)
1306 {
1307 	struct sh_dmae_slave *param = slave;
1308 
1309 	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
1310 		param->slave_id);
1311 
1312 	if (param->dma_dev == chan->device->dev) {
1313 		chan->private = param;
1314 		return true;
1315 	} else {
1316 		return false;
1317 	}
1318 }
1319 
1320 static void rx_timer_fn(unsigned long arg)
1321 {
1322 	struct sci_port *s = (struct sci_port *)arg;
1323 	struct uart_port *port = &s->port;
1324 	u16 scr = sci_in(port, SCSCR);
1325 
1326 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1327 		scr &= ~0x4000;
1328 		enable_irq(s->irqs[1]);
1329 	}
1330 	sci_out(port, SCSCR, scr | SCSCR_RIE);
1331 	dev_dbg(port->dev, "DMA Rx timed out\n");
1332 	schedule_work(&s->work_rx);
1333 }
1334 
1335 static void sci_request_dma(struct uart_port *port)
1336 {
1337 	struct sci_port *s = to_sci_port(port);
1338 	struct sh_dmae_slave *param;
1339 	struct dma_chan *chan;
1340 	dma_cap_mask_t mask;
1341 	int nent;
1342 
1343 	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
1344 		port->line, s->dma_dev);
1345 
1346 	if (!s->dma_dev)
1347 		return;
1348 
1349 	dma_cap_zero(mask);
1350 	dma_cap_set(DMA_SLAVE, mask);
1351 
1352 	param = &s->param_tx;
1353 
1354 	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
1355 	param->slave_id = s->slave_tx;
1356 	param->dma_dev = s->dma_dev;
1357 
1358 	s->cookie_tx = -EINVAL;
1359 	chan = dma_request_channel(mask, filter, param);
1360 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1361 	if (chan) {
1362 		s->chan_tx = chan;
1363 		sg_init_table(&s->sg_tx, 1);
1364 		/* UART circular tx buffer is an aligned page. */
1365 		BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);
1366 		sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
1367 			    UART_XMIT_SIZE, (int)port->state->xmit.buf & ~PAGE_MASK);
1368 		nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
1369 		if (!nent)
1370 			sci_tx_dma_release(s, false);
1371 		else
1372 			dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
1373 				sg_dma_len(&s->sg_tx),
1374 				port->state->xmit.buf, sg_dma_address(&s->sg_tx));
1375 
1376 		s->sg_len_tx = nent;
1377 
1378 		INIT_WORK(&s->work_tx, work_fn_tx);
1379 	}
1380 
1381 	param = &s->param_rx;
1382 
1383 	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
1384 	param->slave_id = s->slave_rx;
1385 	param->dma_dev = s->dma_dev;
1386 
1387 	chan = dma_request_channel(mask, filter, param);
1388 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1389 	if (chan) {
1390 		dma_addr_t dma[2];
1391 		void *buf[2];
1392 		int i;
1393 
1394 		s->chan_rx = chan;
1395 
1396 		s->buf_len_rx = 2 * max(16, (int)port->fifosize);
1397 		buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
1398 					    &dma[0], GFP_KERNEL);
1399 
1400 		if (!buf[0]) {
1401 			dev_warn(port->dev,
1402 				 "failed to allocate dma buffer, using PIO\n");
1403 			sci_rx_dma_release(s, true);
1404 			return;
1405 		}
1406 
1407 		buf[1] = buf[0] + s->buf_len_rx;
1408 		dma[1] = dma[0] + s->buf_len_rx;
1409 
1410 		for (i = 0; i < 2; i++) {
1411 			struct scatterlist *sg = &s->sg_rx[i];
1412 
1413 			sg_init_table(sg, 1);
1414 			sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
1415 				    (int)buf[i] & ~PAGE_MASK);
1416 			sg_dma_address(sg) = dma[i];
1417 		}
1418 
1419 		INIT_WORK(&s->work_rx, work_fn_rx);
1420 		setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1421 
1422 		sci_submit_rx(s);
1423 	}
1424 }
1425 
1426 static void sci_free_dma(struct uart_port *port)
1427 {
1428 	struct sci_port *s = to_sci_port(port);
1429 
1430 	if (!s->dma_dev)
1431 		return;
1432 
1433 	if (s->chan_tx)
1434 		sci_tx_dma_release(s, false);
1435 	if (s->chan_rx)
1436 		sci_rx_dma_release(s, false);
1437 }
1438 #endif
1439 
1440 static int sci_startup(struct uart_port *port)
1441 {
1442 	struct sci_port *s = to_sci_port(port);
1443 
1444 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1445 
1446 	if (s->enable)
1447 		s->enable(port);
1448 
1449 	sci_request_irq(s);
1450 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1451 	sci_request_dma(port);
1452 #endif
1453 	sci_start_tx(port);
1454 	sci_start_rx(port);
1455 
1456 	return 0;
1457 }
1458 
1459 static void sci_shutdown(struct uart_port *port)
1460 {
1461 	struct sci_port *s = to_sci_port(port);
1462 
1463 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1464 
1465 	sci_stop_rx(port);
1466 	sci_stop_tx(port);
1467 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1468 	sci_free_dma(port);
1469 #endif
1470 	sci_free_irq(s);
1471 
1472 	if (s->disable)
1473 		s->disable(port);
1474 }
1475 
1476 static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps,
1477 				   unsigned long freq)
1478 {
1479 	switch (algo_id) {
1480 	case SCBRR_ALGO_1:
1481 		return ((freq + 16 * bps) / (16 * bps) - 1);
1482 	case SCBRR_ALGO_2:
1483 		return ((freq + 16 * bps) / (32 * bps) - 1);
1484 	case SCBRR_ALGO_3:
1485 		return (((freq * 2) + 16 * bps) / (16 * bps) - 1);
1486 	case SCBRR_ALGO_4:
1487 		return (((freq * 2) + 16 * bps) / (32 * bps) - 1);
1488 	case SCBRR_ALGO_5:
1489 		return (((freq * 1000 / 32) / bps) - 1);
1490 	}
1491 
1492 	/* Warn, but use a safe default */
1493 	WARN_ON(1);
1494 	return ((freq + 16 * bps) / (32 * bps) - 1);
1495 }
1496 
1497 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
1498 			    struct ktermios *old)
1499 {
1500 	struct sci_port *s = to_sci_port(port);
1501 	unsigned int status, baud, smr_val, max_baud;
1502 	int t = -1;
1503 	u16 scfcr = 0;
1504 
1505 	/*
1506 	 * earlyprintk comes here early on with port->uartclk set to zero.
1507 	 * the clock framework is not up and running at this point so here
1508 	 * we assume that 115200 is the maximum baud rate. please note that
1509 	 * the baud rate is not programmed during earlyprintk - it is assumed
1510 	 * that the previous boot loader has enabled required clocks and
1511 	 * setup the baud rate generator hardware for us already.
1512 	 */
1513 	max_baud = port->uartclk ? port->uartclk / 16 : 115200;
1514 
1515 	baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
1516 	if (likely(baud && port->uartclk))
1517 		t = sci_scbrr_calc(s->scbrr_algo_id, baud, port->uartclk);
1518 
1519 	do {
1520 		status = sci_in(port, SCxSR);
1521 	} while (!(status & SCxSR_TEND(port)));
1522 
1523 	sci_out(port, SCSCR, 0x00);	/* TE=0, RE=0, CKE1=0 */
1524 
1525 	if (port->type != PORT_SCI)
1526 		sci_out(port, SCFCR, scfcr | SCFCR_RFRST | SCFCR_TFRST);
1527 
1528 	smr_val = sci_in(port, SCSMR) & 3;
1529 	if ((termios->c_cflag & CSIZE) == CS7)
1530 		smr_val |= 0x40;
1531 	if (termios->c_cflag & PARENB)
1532 		smr_val |= 0x20;
1533 	if (termios->c_cflag & PARODD)
1534 		smr_val |= 0x30;
1535 	if (termios->c_cflag & CSTOPB)
1536 		smr_val |= 0x08;
1537 
1538 	uart_update_timeout(port, termios->c_cflag, baud);
1539 
1540 	sci_out(port, SCSMR, smr_val);
1541 
1542 	dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,
1543 		s->scscr);
1544 
1545 	if (t > 0) {
1546 		if (t >= 256) {
1547 			sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
1548 			t >>= 2;
1549 		} else
1550 			sci_out(port, SCSMR, sci_in(port, SCSMR) & ~3);
1551 
1552 		sci_out(port, SCBRR, t);
1553 		udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
1554 	}
1555 
1556 	sci_init_pins(port, termios->c_cflag);
1557 	sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
1558 
1559 	sci_out(port, SCSCR, s->scscr);
1560 
1561 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1562 	/*
1563 	 * Calculate delay for 1.5 DMA buffers: see
1564 	 * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
1565 	 * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
1566 	 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
1567 	 * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
1568 	 * sizes), but it has been found out experimentally, that this is not
1569 	 * enough: the driver too often needlessly runs on a DMA timeout. 20ms
1570 	 * as a minimum seem to work perfectly.
1571 	 */
1572 	if (s->chan_rx) {
1573 		s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
1574 			port->fifosize / 2;
1575 		dev_dbg(port->dev,
1576 			"DMA Rx t-out %ums, tty t-out %u jiffies\n",
1577 			s->rx_timeout * 1000 / HZ, port->timeout);
1578 		if (s->rx_timeout < msecs_to_jiffies(20))
1579 			s->rx_timeout = msecs_to_jiffies(20);
1580 	}
1581 #endif
1582 
1583 	if ((termios->c_cflag & CREAD) != 0)
1584 		sci_start_rx(port);
1585 }
1586 
1587 static const char *sci_type(struct uart_port *port)
1588 {
1589 	switch (port->type) {
1590 	case PORT_IRDA:
1591 		return "irda";
1592 	case PORT_SCI:
1593 		return "sci";
1594 	case PORT_SCIF:
1595 		return "scif";
1596 	case PORT_SCIFA:
1597 		return "scifa";
1598 	case PORT_SCIFB:
1599 		return "scifb";
1600 	}
1601 
1602 	return NULL;
1603 }
1604 
1605 static void sci_release_port(struct uart_port *port)
1606 {
1607 	/* Nothing here yet .. */
1608 }
1609 
1610 static int sci_request_port(struct uart_port *port)
1611 {
1612 	/* Nothing here yet .. */
1613 	return 0;
1614 }
1615 
1616 static void sci_config_port(struct uart_port *port, int flags)
1617 {
1618 	struct sci_port *s = to_sci_port(port);
1619 
1620 	port->type = s->type;
1621 
1622 	if (port->membase)
1623 		return;
1624 
1625 	if (port->flags & UPF_IOREMAP) {
1626 		port->membase = ioremap_nocache(port->mapbase, 0x40);
1627 
1628 		if (IS_ERR(port->membase))
1629 			dev_err(port->dev, "can't remap port#%d\n", port->line);
1630 	} else {
1631 		/*
1632 		 * For the simple (and majority of) cases where we don't
1633 		 * need to do any remapping, just cast the cookie
1634 		 * directly.
1635 		 */
1636 		port->membase = (void __iomem *)port->mapbase;
1637 	}
1638 }
1639 
1640 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
1641 {
1642 	struct sci_port *s = to_sci_port(port);
1643 
1644 	if (ser->irq != s->irqs[SCIx_TXI_IRQ] || ser->irq > nr_irqs)
1645 		return -EINVAL;
1646 	if (ser->baud_base < 2400)
1647 		/* No paper tape reader for Mitch.. */
1648 		return -EINVAL;
1649 
1650 	return 0;
1651 }
1652 
1653 static struct uart_ops sci_uart_ops = {
1654 	.tx_empty	= sci_tx_empty,
1655 	.set_mctrl	= sci_set_mctrl,
1656 	.get_mctrl	= sci_get_mctrl,
1657 	.start_tx	= sci_start_tx,
1658 	.stop_tx	= sci_stop_tx,
1659 	.stop_rx	= sci_stop_rx,
1660 	.enable_ms	= sci_enable_ms,
1661 	.break_ctl	= sci_break_ctl,
1662 	.startup	= sci_startup,
1663 	.shutdown	= sci_shutdown,
1664 	.set_termios	= sci_set_termios,
1665 	.type		= sci_type,
1666 	.release_port	= sci_release_port,
1667 	.request_port	= sci_request_port,
1668 	.config_port	= sci_config_port,
1669 	.verify_port	= sci_verify_port,
1670 #ifdef CONFIG_CONSOLE_POLL
1671 	.poll_get_char	= sci_poll_get_char,
1672 	.poll_put_char	= sci_poll_put_char,
1673 #endif
1674 };
1675 
1676 static int __devinit sci_init_single(struct platform_device *dev,
1677 				     struct sci_port *sci_port,
1678 				     unsigned int index,
1679 				     struct plat_sci_port *p)
1680 {
1681 	struct uart_port *port = &sci_port->port;
1682 
1683 	port->ops	= &sci_uart_ops;
1684 	port->iotype	= UPIO_MEM;
1685 	port->line	= index;
1686 
1687 	switch (p->type) {
1688 	case PORT_SCIFB:
1689 		port->fifosize = 256;
1690 		break;
1691 	case PORT_SCIFA:
1692 		port->fifosize = 64;
1693 		break;
1694 	case PORT_SCIF:
1695 		port->fifosize = 16;
1696 		break;
1697 	default:
1698 		port->fifosize = 1;
1699 		break;
1700 	}
1701 
1702 	if (dev) {
1703 		sci_port->iclk = clk_get(&dev->dev, "sci_ick");
1704 		if (IS_ERR(sci_port->iclk)) {
1705 			sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
1706 			if (IS_ERR(sci_port->iclk)) {
1707 				dev_err(&dev->dev, "can't get iclk\n");
1708 				return PTR_ERR(sci_port->iclk);
1709 			}
1710 		}
1711 
1712 		/*
1713 		 * The function clock is optional, ignore it if we can't
1714 		 * find it.
1715 		 */
1716 		sci_port->fclk = clk_get(&dev->dev, "sci_fck");
1717 		if (IS_ERR(sci_port->fclk))
1718 			sci_port->fclk = NULL;
1719 
1720 		sci_port->enable = sci_clk_enable;
1721 		sci_port->disable = sci_clk_disable;
1722 		port->dev = &dev->dev;
1723 	}
1724 
1725 	sci_port->break_timer.data = (unsigned long)sci_port;
1726 	sci_port->break_timer.function = sci_break_timer;
1727 	init_timer(&sci_port->break_timer);
1728 
1729 	port->mapbase	= p->mapbase;
1730 	port->membase	= p->membase;
1731 
1732 	port->irq		= p->irqs[SCIx_TXI_IRQ];
1733 	port->flags		= p->flags;
1734 	sci_port->type		= port->type = p->type;
1735 	sci_port->scscr		= p->scscr;
1736 	sci_port->scbrr_algo_id	= p->scbrr_algo_id;
1737 
1738 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1739 	sci_port->dma_dev	= p->dma_dev;
1740 	sci_port->slave_tx	= p->dma_slave_tx;
1741 	sci_port->slave_rx	= p->dma_slave_rx;
1742 
1743 	dev_dbg(port->dev, "%s: DMA device %p, tx %d, rx %d\n", __func__,
1744 		p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
1745 #endif
1746 
1747 	memcpy(&sci_port->irqs, &p->irqs, sizeof(p->irqs));
1748 	return 0;
1749 }
1750 
1751 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
1752 static struct tty_driver *serial_console_device(struct console *co, int *index)
1753 {
1754 	struct uart_driver *p = &sci_uart_driver;
1755 	*index = co->index;
1756 	return p->tty_driver;
1757 }
1758 
1759 static void serial_console_putchar(struct uart_port *port, int ch)
1760 {
1761 	sci_poll_put_char(port, ch);
1762 }
1763 
1764 /*
1765  *	Print a string to the serial port trying not to disturb
1766  *	any possible real use of the port...
1767  */
1768 static void serial_console_write(struct console *co, const char *s,
1769 				 unsigned count)
1770 {
1771 	struct uart_port *port = co->data;
1772 	struct sci_port *sci_port = to_sci_port(port);
1773 	unsigned short bits;
1774 
1775 	if (sci_port->enable)
1776 		sci_port->enable(port);
1777 
1778 	uart_console_write(port, s, count, serial_console_putchar);
1779 
1780 	/* wait until fifo is empty and last bit has been transmitted */
1781 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
1782 	while ((sci_in(port, SCxSR) & bits) != bits)
1783 		cpu_relax();
1784 
1785 	if (sci_port->disable)
1786 		sci_port->disable(port);
1787 }
1788 
1789 static int __devinit serial_console_setup(struct console *co, char *options)
1790 {
1791 	struct sci_port *sci_port;
1792 	struct uart_port *port;
1793 	int baud = 115200;
1794 	int bits = 8;
1795 	int parity = 'n';
1796 	int flow = 'n';
1797 	int ret;
1798 
1799 	/*
1800 	 * Check whether an invalid uart number has been specified, and
1801 	 * if so, search for the first available port that does have
1802 	 * console support.
1803 	 */
1804 	if (co->index >= SCI_NPORTS)
1805 		co->index = 0;
1806 
1807 	if (co->data) {
1808 		port = co->data;
1809 		sci_port = to_sci_port(port);
1810 	} else {
1811 		sci_port = &sci_ports[co->index];
1812 		port = &sci_port->port;
1813 		co->data = port;
1814 	}
1815 
1816 	/*
1817 	 * Also need to check port->type, we don't actually have any
1818 	 * UPIO_PORT ports, but uart_report_port() handily misreports
1819 	 * it anyways if we don't have a port available by the time this is
1820 	 * called.
1821 	 */
1822 	if (!port->type)
1823 		return -ENODEV;
1824 
1825 	sci_config_port(port, 0);
1826 
1827 	if (sci_port->enable)
1828 		sci_port->enable(port);
1829 
1830 	if (options)
1831 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1832 
1833 	ret = uart_set_options(port, co, baud, parity, bits, flow);
1834 #if defined(__H8300H__) || defined(__H8300S__)
1835 	/* disable rx interrupt */
1836 	if (ret == 0)
1837 		sci_stop_rx(port);
1838 #endif
1839 	/* TODO: disable clock */
1840 	return ret;
1841 }
1842 
1843 static struct console serial_console = {
1844 	.name		= "ttySC",
1845 	.device		= serial_console_device,
1846 	.write		= serial_console_write,
1847 	.setup		= serial_console_setup,
1848 	.flags		= CON_PRINTBUFFER,
1849 	.index		= -1,
1850 };
1851 
1852 static int __init sci_console_init(void)
1853 {
1854 	register_console(&serial_console);
1855 	return 0;
1856 }
1857 console_initcall(sci_console_init);
1858 
1859 static struct sci_port early_serial_port;
1860 static struct console early_serial_console = {
1861 	.name           = "early_ttySC",
1862 	.write          = serial_console_write,
1863 	.flags          = CON_PRINTBUFFER,
1864 };
1865 static char early_serial_buf[32];
1866 
1867 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
1868 
1869 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
1870 #define SCI_CONSOLE	(&serial_console)
1871 #else
1872 #define SCI_CONSOLE	0
1873 #endif
1874 
1875 static char banner[] __initdata =
1876 	KERN_INFO "SuperH SCI(F) driver initialized\n";
1877 
1878 static struct uart_driver sci_uart_driver = {
1879 	.owner		= THIS_MODULE,
1880 	.driver_name	= "sci",
1881 	.dev_name	= "ttySC",
1882 	.major		= SCI_MAJOR,
1883 	.minor		= SCI_MINOR_START,
1884 	.nr		= SCI_NPORTS,
1885 	.cons		= SCI_CONSOLE,
1886 };
1887 
1888 
1889 static int sci_remove(struct platform_device *dev)
1890 {
1891 	struct sh_sci_priv *priv = platform_get_drvdata(dev);
1892 	struct sci_port *p;
1893 	unsigned long flags;
1894 
1895 	cpufreq_unregister_notifier(&priv->clk_nb, CPUFREQ_TRANSITION_NOTIFIER);
1896 
1897 	spin_lock_irqsave(&priv->lock, flags);
1898 	list_for_each_entry(p, &priv->ports, node) {
1899 		uart_remove_one_port(&sci_uart_driver, &p->port);
1900 		clk_put(p->iclk);
1901 		clk_put(p->fclk);
1902 	}
1903 	spin_unlock_irqrestore(&priv->lock, flags);
1904 
1905 	kfree(priv);
1906 	return 0;
1907 }
1908 
1909 static int __devinit sci_probe_single(struct platform_device *dev,
1910 				      unsigned int index,
1911 				      struct plat_sci_port *p,
1912 				      struct sci_port *sciport)
1913 {
1914 	struct sh_sci_priv *priv = platform_get_drvdata(dev);
1915 	unsigned long flags;
1916 	int ret;
1917 
1918 	/* Sanity check */
1919 	if (unlikely(index >= SCI_NPORTS)) {
1920 		dev_notice(&dev->dev, "Attempting to register port "
1921 			   "%d when only %d are available.\n",
1922 			   index+1, SCI_NPORTS);
1923 		dev_notice(&dev->dev, "Consider bumping "
1924 			   "CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
1925 		return 0;
1926 	}
1927 
1928 	ret = sci_init_single(dev, sciport, index, p);
1929 	if (ret)
1930 		return ret;
1931 
1932 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
1933 	if (ret)
1934 		return ret;
1935 
1936 	INIT_LIST_HEAD(&sciport->node);
1937 
1938 	spin_lock_irqsave(&priv->lock, flags);
1939 	list_add(&sciport->node, &priv->ports);
1940 	spin_unlock_irqrestore(&priv->lock, flags);
1941 
1942 	return 0;
1943 }
1944 
1945 /*
1946  * Register a set of serial devices attached to a platform device.  The
1947  * list is terminated with a zero flags entry, which means we expect
1948  * all entries to have at least UPF_BOOT_AUTOCONF set. Platforms that need
1949  * remapping (such as sh64) should also set UPF_IOREMAP.
1950  */
1951 static int __devinit sci_probe(struct platform_device *dev)
1952 {
1953 	struct plat_sci_port *p = dev->dev.platform_data;
1954 	struct sh_sci_priv *priv;
1955 	int i, ret = -EINVAL;
1956 
1957 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
1958 	if (is_early_platform_device(dev)) {
1959 		if (dev->id == -1)
1960 			return -ENOTSUPP;
1961 		early_serial_console.index = dev->id;
1962 		early_serial_console.data = &early_serial_port.port;
1963 		sci_init_single(NULL, &early_serial_port, dev->id, p);
1964 		serial_console_setup(&early_serial_console, early_serial_buf);
1965 		if (!strstr(early_serial_buf, "keep"))
1966 			early_serial_console.flags |= CON_BOOT;
1967 		register_console(&early_serial_console);
1968 		return 0;
1969 	}
1970 #endif
1971 
1972 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1973 	if (!priv)
1974 		return -ENOMEM;
1975 
1976 	INIT_LIST_HEAD(&priv->ports);
1977 	spin_lock_init(&priv->lock);
1978 	platform_set_drvdata(dev, priv);
1979 
1980 	priv->clk_nb.notifier_call = sci_notifier;
1981 	cpufreq_register_notifier(&priv->clk_nb, CPUFREQ_TRANSITION_NOTIFIER);
1982 
1983 	if (dev->id != -1) {
1984 		ret = sci_probe_single(dev, dev->id, p, &sci_ports[dev->id]);
1985 		if (ret)
1986 			goto err_unreg;
1987 	} else {
1988 		for (i = 0; p && p->flags != 0; p++, i++) {
1989 			ret = sci_probe_single(dev, i, p, &sci_ports[i]);
1990 			if (ret)
1991 				goto err_unreg;
1992 		}
1993 	}
1994 
1995 #ifdef CONFIG_SH_STANDARD_BIOS
1996 	sh_bios_gdb_detach();
1997 #endif
1998 
1999 	return 0;
2000 
2001 err_unreg:
2002 	sci_remove(dev);
2003 	return ret;
2004 }
2005 
2006 static int sci_suspend(struct device *dev)
2007 {
2008 	struct sh_sci_priv *priv = dev_get_drvdata(dev);
2009 	struct sci_port *p;
2010 	unsigned long flags;
2011 
2012 	spin_lock_irqsave(&priv->lock, flags);
2013 	list_for_each_entry(p, &priv->ports, node)
2014 		uart_suspend_port(&sci_uart_driver, &p->port);
2015 	spin_unlock_irqrestore(&priv->lock, flags);
2016 
2017 	return 0;
2018 }
2019 
2020 static int sci_resume(struct device *dev)
2021 {
2022 	struct sh_sci_priv *priv = dev_get_drvdata(dev);
2023 	struct sci_port *p;
2024 	unsigned long flags;
2025 
2026 	spin_lock_irqsave(&priv->lock, flags);
2027 	list_for_each_entry(p, &priv->ports, node)
2028 		uart_resume_port(&sci_uart_driver, &p->port);
2029 	spin_unlock_irqrestore(&priv->lock, flags);
2030 
2031 	return 0;
2032 }
2033 
2034 static const struct dev_pm_ops sci_dev_pm_ops = {
2035 	.suspend	= sci_suspend,
2036 	.resume		= sci_resume,
2037 };
2038 
2039 static struct platform_driver sci_driver = {
2040 	.probe		= sci_probe,
2041 	.remove		= sci_remove,
2042 	.driver		= {
2043 		.name	= "sh-sci",
2044 		.owner	= THIS_MODULE,
2045 		.pm	= &sci_dev_pm_ops,
2046 	},
2047 };
2048 
2049 static int __init sci_init(void)
2050 {
2051 	int ret;
2052 
2053 	printk(banner);
2054 
2055 	ret = uart_register_driver(&sci_uart_driver);
2056 	if (likely(ret == 0)) {
2057 		ret = platform_driver_register(&sci_driver);
2058 		if (unlikely(ret))
2059 			uart_unregister_driver(&sci_uart_driver);
2060 	}
2061 
2062 	return ret;
2063 }
2064 
2065 static void __exit sci_exit(void)
2066 {
2067 	platform_driver_unregister(&sci_driver);
2068 	uart_unregister_driver(&sci_uart_driver);
2069 }
2070 
2071 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2072 early_platform_init_buffer("earlyprintk", &sci_driver,
2073 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
2074 #endif
2075 module_init(sci_init);
2076 module_exit(sci_exit);
2077 
2078 MODULE_LICENSE("GPL");
2079 MODULE_ALIAS("platform:sh-sci");
2080