xref: /linux/drivers/tty/serial/sh-sci.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
3  *
4  *  Copyright (C) 2002 - 2011  Paul Mundt
5  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
6  *
7  * based off of the old drivers/char/sh-sci.c by:
8  *
9  *   Copyright (C) 1999, 2000  Niibe Yutaka
10  *   Copyright (C) 2000  Sugioka Toshinobu
11  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
12  *   Modified to support SecureEdge. David McCullough (2002)
13  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
14  *   Removed SH7300 support (Jul 2007).
15  *
16  * This file is subject to the terms and conditions of the GNU General Public
17  * License.  See the file "COPYING" in the main directory of this archive
18  * for more details.
19  */
20 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
21 #define SUPPORT_SYSRQ
22 #endif
23 
24 #undef DEBUG
25 
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/timer.h>
29 #include <linux/interrupt.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial.h>
33 #include <linux/major.h>
34 #include <linux/string.h>
35 #include <linux/sysrq.h>
36 #include <linux/ioport.h>
37 #include <linux/mm.h>
38 #include <linux/init.h>
39 #include <linux/delay.h>
40 #include <linux/console.h>
41 #include <linux/platform_device.h>
42 #include <linux/serial_sci.h>
43 #include <linux/notifier.h>
44 #include <linux/pm_runtime.h>
45 #include <linux/cpufreq.h>
46 #include <linux/clk.h>
47 #include <linux/ctype.h>
48 #include <linux/err.h>
49 #include <linux/dmaengine.h>
50 #include <linux/dma-mapping.h>
51 #include <linux/scatterlist.h>
52 #include <linux/slab.h>
53 
54 #ifdef CONFIG_SUPERH
55 #include <asm/sh_bios.h>
56 #endif
57 
58 #include "sh-sci.h"
59 
60 struct sci_port {
61 	struct uart_port	port;
62 
63 	/* Platform configuration */
64 	struct plat_sci_port	*cfg;
65 
66 	/* Break timer */
67 	struct timer_list	break_timer;
68 	int			break_flag;
69 
70 	/* Interface clock */
71 	struct clk		*iclk;
72 	/* Function clock */
73 	struct clk		*fclk;
74 
75 	char			*irqstr[SCIx_NR_IRQS];
76 
77 	struct dma_chan			*chan_tx;
78 	struct dma_chan			*chan_rx;
79 
80 #ifdef CONFIG_SERIAL_SH_SCI_DMA
81 	struct dma_async_tx_descriptor	*desc_tx;
82 	struct dma_async_tx_descriptor	*desc_rx[2];
83 	dma_cookie_t			cookie_tx;
84 	dma_cookie_t			cookie_rx[2];
85 	dma_cookie_t			active_rx;
86 	struct scatterlist		sg_tx;
87 	unsigned int			sg_len_tx;
88 	struct scatterlist		sg_rx[2];
89 	size_t				buf_len_rx;
90 	struct sh_dmae_slave		param_tx;
91 	struct sh_dmae_slave		param_rx;
92 	struct work_struct		work_tx;
93 	struct work_struct		work_rx;
94 	struct timer_list		rx_timer;
95 	unsigned int			rx_timeout;
96 #endif
97 
98 	struct notifier_block		freq_transition;
99 
100 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
101 	unsigned short saved_smr;
102 	unsigned short saved_fcr;
103 	unsigned char saved_brr;
104 #endif
105 };
106 
107 /* Function prototypes */
108 static void sci_start_tx(struct uart_port *port);
109 static void sci_stop_tx(struct uart_port *port);
110 static void sci_start_rx(struct uart_port *port);
111 
112 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
113 
114 static struct sci_port sci_ports[SCI_NPORTS];
115 static struct uart_driver sci_uart_driver;
116 
117 static inline struct sci_port *
118 to_sci_port(struct uart_port *uart)
119 {
120 	return container_of(uart, struct sci_port, port);
121 }
122 
123 struct plat_sci_reg {
124 	u8 offset, size;
125 };
126 
127 /* Helper for invalidating specific entries of an inherited map. */
128 #define sci_reg_invalid	{ .offset = 0, .size = 0 }
129 
130 static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
131 	[SCIx_PROBE_REGTYPE] = {
132 		[0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
133 	},
134 
135 	/*
136 	 * Common SCI definitions, dependent on the port's regshift
137 	 * value.
138 	 */
139 	[SCIx_SCI_REGTYPE] = {
140 		[SCSMR]		= { 0x00,  8 },
141 		[SCBRR]		= { 0x01,  8 },
142 		[SCSCR]		= { 0x02,  8 },
143 		[SCxTDR]	= { 0x03,  8 },
144 		[SCxSR]		= { 0x04,  8 },
145 		[SCxRDR]	= { 0x05,  8 },
146 		[SCFCR]		= sci_reg_invalid,
147 		[SCFDR]		= sci_reg_invalid,
148 		[SCTFDR]	= sci_reg_invalid,
149 		[SCRFDR]	= sci_reg_invalid,
150 		[SCSPTR]	= sci_reg_invalid,
151 		[SCLSR]		= sci_reg_invalid,
152 	},
153 
154 	/*
155 	 * Common definitions for legacy IrDA ports, dependent on
156 	 * regshift value.
157 	 */
158 	[SCIx_IRDA_REGTYPE] = {
159 		[SCSMR]		= { 0x00,  8 },
160 		[SCBRR]		= { 0x01,  8 },
161 		[SCSCR]		= { 0x02,  8 },
162 		[SCxTDR]	= { 0x03,  8 },
163 		[SCxSR]		= { 0x04,  8 },
164 		[SCxRDR]	= { 0x05,  8 },
165 		[SCFCR]		= { 0x06,  8 },
166 		[SCFDR]		= { 0x07, 16 },
167 		[SCTFDR]	= sci_reg_invalid,
168 		[SCRFDR]	= sci_reg_invalid,
169 		[SCSPTR]	= sci_reg_invalid,
170 		[SCLSR]		= sci_reg_invalid,
171 	},
172 
173 	/*
174 	 * Common SCIFA definitions.
175 	 */
176 	[SCIx_SCIFA_REGTYPE] = {
177 		[SCSMR]		= { 0x00, 16 },
178 		[SCBRR]		= { 0x04,  8 },
179 		[SCSCR]		= { 0x08, 16 },
180 		[SCxTDR]	= { 0x20,  8 },
181 		[SCxSR]		= { 0x14, 16 },
182 		[SCxRDR]	= { 0x24,  8 },
183 		[SCFCR]		= { 0x18, 16 },
184 		[SCFDR]		= { 0x1c, 16 },
185 		[SCTFDR]	= sci_reg_invalid,
186 		[SCRFDR]	= sci_reg_invalid,
187 		[SCSPTR]	= sci_reg_invalid,
188 		[SCLSR]		= sci_reg_invalid,
189 	},
190 
191 	/*
192 	 * Common SCIFB definitions.
193 	 */
194 	[SCIx_SCIFB_REGTYPE] = {
195 		[SCSMR]		= { 0x00, 16 },
196 		[SCBRR]		= { 0x04,  8 },
197 		[SCSCR]		= { 0x08, 16 },
198 		[SCxTDR]	= { 0x40,  8 },
199 		[SCxSR]		= { 0x14, 16 },
200 		[SCxRDR]	= { 0x60,  8 },
201 		[SCFCR]		= { 0x18, 16 },
202 		[SCFDR]		= { 0x1c, 16 },
203 		[SCTFDR]	= sci_reg_invalid,
204 		[SCRFDR]	= sci_reg_invalid,
205 		[SCSPTR]	= sci_reg_invalid,
206 		[SCLSR]		= sci_reg_invalid,
207 	},
208 
209 	/*
210 	 * Common SH-3 SCIF definitions.
211 	 */
212 	[SCIx_SH3_SCIF_REGTYPE] = {
213 		[SCSMR]		= { 0x00,  8 },
214 		[SCBRR]		= { 0x02,  8 },
215 		[SCSCR]		= { 0x04,  8 },
216 		[SCxTDR]	= { 0x06,  8 },
217 		[SCxSR]		= { 0x08, 16 },
218 		[SCxRDR]	= { 0x0a,  8 },
219 		[SCFCR]		= { 0x0c,  8 },
220 		[SCFDR]		= { 0x0e, 16 },
221 		[SCTFDR]	= sci_reg_invalid,
222 		[SCRFDR]	= sci_reg_invalid,
223 		[SCSPTR]	= sci_reg_invalid,
224 		[SCLSR]		= sci_reg_invalid,
225 	},
226 
227 	/*
228 	 * Common SH-4(A) SCIF(B) definitions.
229 	 */
230 	[SCIx_SH4_SCIF_REGTYPE] = {
231 		[SCSMR]		= { 0x00, 16 },
232 		[SCBRR]		= { 0x04,  8 },
233 		[SCSCR]		= { 0x08, 16 },
234 		[SCxTDR]	= { 0x0c,  8 },
235 		[SCxSR]		= { 0x10, 16 },
236 		[SCxRDR]	= { 0x14,  8 },
237 		[SCFCR]		= { 0x18, 16 },
238 		[SCFDR]		= { 0x1c, 16 },
239 		[SCTFDR]	= sci_reg_invalid,
240 		[SCRFDR]	= sci_reg_invalid,
241 		[SCSPTR]	= { 0x20, 16 },
242 		[SCLSR]		= { 0x24, 16 },
243 	},
244 
245 	/*
246 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
247 	 * register.
248 	 */
249 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
250 		[SCSMR]		= { 0x00, 16 },
251 		[SCBRR]		= { 0x04,  8 },
252 		[SCSCR]		= { 0x08, 16 },
253 		[SCxTDR]	= { 0x0c,  8 },
254 		[SCxSR]		= { 0x10, 16 },
255 		[SCxRDR]	= { 0x14,  8 },
256 		[SCFCR]		= { 0x18, 16 },
257 		[SCFDR]		= { 0x1c, 16 },
258 		[SCTFDR]	= sci_reg_invalid,
259 		[SCRFDR]	= sci_reg_invalid,
260 		[SCSPTR]	= sci_reg_invalid,
261 		[SCLSR]		= { 0x24, 16 },
262 	},
263 
264 	/*
265 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
266 	 * count registers.
267 	 */
268 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
269 		[SCSMR]		= { 0x00, 16 },
270 		[SCBRR]		= { 0x04,  8 },
271 		[SCSCR]		= { 0x08, 16 },
272 		[SCxTDR]	= { 0x0c,  8 },
273 		[SCxSR]		= { 0x10, 16 },
274 		[SCxRDR]	= { 0x14,  8 },
275 		[SCFCR]		= { 0x18, 16 },
276 		[SCFDR]		= { 0x1c, 16 },
277 		[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
278 		[SCRFDR]	= { 0x20, 16 },
279 		[SCSPTR]	= { 0x24, 16 },
280 		[SCLSR]		= { 0x28, 16 },
281 	},
282 
283 	/*
284 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
285 	 * registers.
286 	 */
287 	[SCIx_SH7705_SCIF_REGTYPE] = {
288 		[SCSMR]		= { 0x00, 16 },
289 		[SCBRR]		= { 0x04,  8 },
290 		[SCSCR]		= { 0x08, 16 },
291 		[SCxTDR]	= { 0x20,  8 },
292 		[SCxSR]		= { 0x14, 16 },
293 		[SCxRDR]	= { 0x24,  8 },
294 		[SCFCR]		= { 0x18, 16 },
295 		[SCFDR]		= { 0x1c, 16 },
296 		[SCTFDR]	= sci_reg_invalid,
297 		[SCRFDR]	= sci_reg_invalid,
298 		[SCSPTR]	= sci_reg_invalid,
299 		[SCLSR]		= sci_reg_invalid,
300 	},
301 };
302 
303 #define sci_getreg(up, offset)		(sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
304 
305 /*
306  * The "offset" here is rather misleading, in that it refers to an enum
307  * value relative to the port mapping rather than the fixed offset
308  * itself, which needs to be manually retrieved from the platform's
309  * register map for the given port.
310  */
311 static unsigned int sci_serial_in(struct uart_port *p, int offset)
312 {
313 	struct plat_sci_reg *reg = sci_getreg(p, offset);
314 
315 	if (reg->size == 8)
316 		return ioread8(p->membase + (reg->offset << p->regshift));
317 	else if (reg->size == 16)
318 		return ioread16(p->membase + (reg->offset << p->regshift));
319 	else
320 		WARN(1, "Invalid register access\n");
321 
322 	return 0;
323 }
324 
325 static void sci_serial_out(struct uart_port *p, int offset, int value)
326 {
327 	struct plat_sci_reg *reg = sci_getreg(p, offset);
328 
329 	if (reg->size == 8)
330 		iowrite8(value, p->membase + (reg->offset << p->regshift));
331 	else if (reg->size == 16)
332 		iowrite16(value, p->membase + (reg->offset << p->regshift));
333 	else
334 		WARN(1, "Invalid register access\n");
335 }
336 
337 #define sci_in(up, offset)		(up->serial_in(up, offset))
338 #define sci_out(up, offset, value)	(up->serial_out(up, offset, value))
339 
340 static int sci_probe_regmap(struct plat_sci_port *cfg)
341 {
342 	switch (cfg->type) {
343 	case PORT_SCI:
344 		cfg->regtype = SCIx_SCI_REGTYPE;
345 		break;
346 	case PORT_IRDA:
347 		cfg->regtype = SCIx_IRDA_REGTYPE;
348 		break;
349 	case PORT_SCIFA:
350 		cfg->regtype = SCIx_SCIFA_REGTYPE;
351 		break;
352 	case PORT_SCIFB:
353 		cfg->regtype = SCIx_SCIFB_REGTYPE;
354 		break;
355 	case PORT_SCIF:
356 		/*
357 		 * The SH-4 is a bit of a misnomer here, although that's
358 		 * where this particular port layout originated. This
359 		 * configuration (or some slight variation thereof)
360 		 * remains the dominant model for all SCIFs.
361 		 */
362 		cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
363 		break;
364 	default:
365 		printk(KERN_ERR "Can't probe register map for given port\n");
366 		return -EINVAL;
367 	}
368 
369 	return 0;
370 }
371 
372 static void sci_port_enable(struct sci_port *sci_port)
373 {
374 	if (!sci_port->port.dev)
375 		return;
376 
377 	pm_runtime_get_sync(sci_port->port.dev);
378 
379 	clk_enable(sci_port->iclk);
380 	sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
381 	clk_enable(sci_port->fclk);
382 }
383 
384 static void sci_port_disable(struct sci_port *sci_port)
385 {
386 	if (!sci_port->port.dev)
387 		return;
388 
389 	clk_disable(sci_port->fclk);
390 	clk_disable(sci_port->iclk);
391 
392 	pm_runtime_put_sync(sci_port->port.dev);
393 }
394 
395 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
396 
397 #ifdef CONFIG_CONSOLE_POLL
398 static int sci_poll_get_char(struct uart_port *port)
399 {
400 	unsigned short status;
401 	int c;
402 
403 	do {
404 		status = sci_in(port, SCxSR);
405 		if (status & SCxSR_ERRORS(port)) {
406 			sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
407 			continue;
408 		}
409 		break;
410 	} while (1);
411 
412 	if (!(status & SCxSR_RDxF(port)))
413 		return NO_POLL_CHAR;
414 
415 	c = sci_in(port, SCxRDR);
416 
417 	/* Dummy read */
418 	sci_in(port, SCxSR);
419 	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
420 
421 	return c;
422 }
423 #endif
424 
425 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
426 {
427 	unsigned short status;
428 
429 	do {
430 		status = sci_in(port, SCxSR);
431 	} while (!(status & SCxSR_TDxE(port)));
432 
433 	sci_out(port, SCxTDR, c);
434 	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
435 }
436 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
437 
438 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
439 {
440 	struct sci_port *s = to_sci_port(port);
441 	struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
442 
443 	/*
444 	 * Use port-specific handler if provided.
445 	 */
446 	if (s->cfg->ops && s->cfg->ops->init_pins) {
447 		s->cfg->ops->init_pins(port, cflag);
448 		return;
449 	}
450 
451 	/*
452 	 * For the generic path SCSPTR is necessary. Bail out if that's
453 	 * unavailable, too.
454 	 */
455 	if (!reg->size)
456 		return;
457 
458 	if (!(cflag & CRTSCTS))
459 		sci_out(port, SCSPTR, 0x0080); /* Set RTS = 1 */
460 }
461 
462 static int sci_txfill(struct uart_port *port)
463 {
464 	struct plat_sci_reg *reg;
465 
466 	reg = sci_getreg(port, SCTFDR);
467 	if (reg->size)
468 		return sci_in(port, SCTFDR) & 0xff;
469 
470 	reg = sci_getreg(port, SCFDR);
471 	if (reg->size)
472 		return sci_in(port, SCFDR) >> 8;
473 
474 	return !(sci_in(port, SCxSR) & SCI_TDRE);
475 }
476 
477 static int sci_txroom(struct uart_port *port)
478 {
479 	return port->fifosize - sci_txfill(port);
480 }
481 
482 static int sci_rxfill(struct uart_port *port)
483 {
484 	struct plat_sci_reg *reg;
485 
486 	reg = sci_getreg(port, SCRFDR);
487 	if (reg->size)
488 		return sci_in(port, SCRFDR) & 0xff;
489 
490 	reg = sci_getreg(port, SCFDR);
491 	if (reg->size)
492 		return sci_in(port, SCFDR) & ((port->fifosize << 1) - 1);
493 
494 	return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
495 }
496 
497 /*
498  * SCI helper for checking the state of the muxed port/RXD pins.
499  */
500 static inline int sci_rxd_in(struct uart_port *port)
501 {
502 	struct sci_port *s = to_sci_port(port);
503 
504 	if (s->cfg->port_reg <= 0)
505 		return 1;
506 
507 	return !!__raw_readb(s->cfg->port_reg);
508 }
509 
510 /* ********************************************************************** *
511  *                   the interrupt related routines                       *
512  * ********************************************************************** */
513 
514 static void sci_transmit_chars(struct uart_port *port)
515 {
516 	struct circ_buf *xmit = &port->state->xmit;
517 	unsigned int stopped = uart_tx_stopped(port);
518 	unsigned short status;
519 	unsigned short ctrl;
520 	int count;
521 
522 	status = sci_in(port, SCxSR);
523 	if (!(status & SCxSR_TDxE(port))) {
524 		ctrl = sci_in(port, SCSCR);
525 		if (uart_circ_empty(xmit))
526 			ctrl &= ~SCSCR_TIE;
527 		else
528 			ctrl |= SCSCR_TIE;
529 		sci_out(port, SCSCR, ctrl);
530 		return;
531 	}
532 
533 	count = sci_txroom(port);
534 
535 	do {
536 		unsigned char c;
537 
538 		if (port->x_char) {
539 			c = port->x_char;
540 			port->x_char = 0;
541 		} else if (!uart_circ_empty(xmit) && !stopped) {
542 			c = xmit->buf[xmit->tail];
543 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
544 		} else {
545 			break;
546 		}
547 
548 		sci_out(port, SCxTDR, c);
549 
550 		port->icount.tx++;
551 	} while (--count > 0);
552 
553 	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
554 
555 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
556 		uart_write_wakeup(port);
557 	if (uart_circ_empty(xmit)) {
558 		sci_stop_tx(port);
559 	} else {
560 		ctrl = sci_in(port, SCSCR);
561 
562 		if (port->type != PORT_SCI) {
563 			sci_in(port, SCxSR); /* Dummy read */
564 			sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
565 		}
566 
567 		ctrl |= SCSCR_TIE;
568 		sci_out(port, SCSCR, ctrl);
569 	}
570 }
571 
572 /* On SH3, SCIF may read end-of-break as a space->mark char */
573 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
574 
575 static void sci_receive_chars(struct uart_port *port)
576 {
577 	struct sci_port *sci_port = to_sci_port(port);
578 	struct tty_struct *tty = port->state->port.tty;
579 	int i, count, copied = 0;
580 	unsigned short status;
581 	unsigned char flag;
582 
583 	status = sci_in(port, SCxSR);
584 	if (!(status & SCxSR_RDxF(port)))
585 		return;
586 
587 	while (1) {
588 		/* Don't copy more bytes than there is room for in the buffer */
589 		count = tty_buffer_request_room(tty, sci_rxfill(port));
590 
591 		/* If for any reason we can't copy more data, we're done! */
592 		if (count == 0)
593 			break;
594 
595 		if (port->type == PORT_SCI) {
596 			char c = sci_in(port, SCxRDR);
597 			if (uart_handle_sysrq_char(port, c) ||
598 			    sci_port->break_flag)
599 				count = 0;
600 			else
601 				tty_insert_flip_char(tty, c, TTY_NORMAL);
602 		} else {
603 			for (i = 0; i < count; i++) {
604 				char c = sci_in(port, SCxRDR);
605 				status = sci_in(port, SCxSR);
606 #if defined(CONFIG_CPU_SH3)
607 				/* Skip "chars" during break */
608 				if (sci_port->break_flag) {
609 					if ((c == 0) &&
610 					    (status & SCxSR_FER(port))) {
611 						count--; i--;
612 						continue;
613 					}
614 
615 					/* Nonzero => end-of-break */
616 					dev_dbg(port->dev, "debounce<%02x>\n", c);
617 					sci_port->break_flag = 0;
618 
619 					if (STEPFN(c)) {
620 						count--; i--;
621 						continue;
622 					}
623 				}
624 #endif /* CONFIG_CPU_SH3 */
625 				if (uart_handle_sysrq_char(port, c)) {
626 					count--; i--;
627 					continue;
628 				}
629 
630 				/* Store data and status */
631 				if (status & SCxSR_FER(port)) {
632 					flag = TTY_FRAME;
633 					dev_notice(port->dev, "frame error\n");
634 				} else if (status & SCxSR_PER(port)) {
635 					flag = TTY_PARITY;
636 					dev_notice(port->dev, "parity error\n");
637 				} else
638 					flag = TTY_NORMAL;
639 
640 				tty_insert_flip_char(tty, c, flag);
641 			}
642 		}
643 
644 		sci_in(port, SCxSR); /* dummy read */
645 		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
646 
647 		copied += count;
648 		port->icount.rx += count;
649 	}
650 
651 	if (copied) {
652 		/* Tell the rest of the system the news. New characters! */
653 		tty_flip_buffer_push(tty);
654 	} else {
655 		sci_in(port, SCxSR); /* dummy read */
656 		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
657 	}
658 }
659 
660 #define SCI_BREAK_JIFFIES (HZ/20)
661 
662 /*
663  * The sci generates interrupts during the break,
664  * 1 per millisecond or so during the break period, for 9600 baud.
665  * So dont bother disabling interrupts.
666  * But dont want more than 1 break event.
667  * Use a kernel timer to periodically poll the rx line until
668  * the break is finished.
669  */
670 static inline void sci_schedule_break_timer(struct sci_port *port)
671 {
672 	mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
673 }
674 
675 /* Ensure that two consecutive samples find the break over. */
676 static void sci_break_timer(unsigned long data)
677 {
678 	struct sci_port *port = (struct sci_port *)data;
679 
680 	sci_port_enable(port);
681 
682 	if (sci_rxd_in(&port->port) == 0) {
683 		port->break_flag = 1;
684 		sci_schedule_break_timer(port);
685 	} else if (port->break_flag == 1) {
686 		/* break is over. */
687 		port->break_flag = 2;
688 		sci_schedule_break_timer(port);
689 	} else
690 		port->break_flag = 0;
691 
692 	sci_port_disable(port);
693 }
694 
695 static int sci_handle_errors(struct uart_port *port)
696 {
697 	int copied = 0;
698 	unsigned short status = sci_in(port, SCxSR);
699 	struct tty_struct *tty = port->state->port.tty;
700 	struct sci_port *s = to_sci_port(port);
701 
702 	/*
703 	 * Handle overruns, if supported.
704 	 */
705 	if (s->cfg->overrun_bit != SCIx_NOT_SUPPORTED) {
706 		if (status & (1 << s->cfg->overrun_bit)) {
707 			/* overrun error */
708 			if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
709 				copied++;
710 
711 			dev_notice(port->dev, "overrun error");
712 		}
713 	}
714 
715 	if (status & SCxSR_FER(port)) {
716 		if (sci_rxd_in(port) == 0) {
717 			/* Notify of BREAK */
718 			struct sci_port *sci_port = to_sci_port(port);
719 
720 			if (!sci_port->break_flag) {
721 				sci_port->break_flag = 1;
722 				sci_schedule_break_timer(sci_port);
723 
724 				/* Do sysrq handling. */
725 				if (uart_handle_break(port))
726 					return 0;
727 
728 				dev_dbg(port->dev, "BREAK detected\n");
729 
730 				if (tty_insert_flip_char(tty, 0, TTY_BREAK))
731 					copied++;
732 			}
733 
734 		} else {
735 			/* frame error */
736 			if (tty_insert_flip_char(tty, 0, TTY_FRAME))
737 				copied++;
738 
739 			dev_notice(port->dev, "frame error\n");
740 		}
741 	}
742 
743 	if (status & SCxSR_PER(port)) {
744 		/* parity error */
745 		if (tty_insert_flip_char(tty, 0, TTY_PARITY))
746 			copied++;
747 
748 		dev_notice(port->dev, "parity error");
749 	}
750 
751 	if (copied)
752 		tty_flip_buffer_push(tty);
753 
754 	return copied;
755 }
756 
757 static int sci_handle_fifo_overrun(struct uart_port *port)
758 {
759 	struct tty_struct *tty = port->state->port.tty;
760 	struct sci_port *s = to_sci_port(port);
761 	struct plat_sci_reg *reg;
762 	int copied = 0;
763 
764 	reg = sci_getreg(port, SCLSR);
765 	if (!reg->size)
766 		return 0;
767 
768 	if ((sci_in(port, SCLSR) & (1 << s->cfg->overrun_bit))) {
769 		sci_out(port, SCLSR, 0);
770 
771 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
772 		tty_flip_buffer_push(tty);
773 
774 		dev_notice(port->dev, "overrun error\n");
775 		copied++;
776 	}
777 
778 	return copied;
779 }
780 
781 static int sci_handle_breaks(struct uart_port *port)
782 {
783 	int copied = 0;
784 	unsigned short status = sci_in(port, SCxSR);
785 	struct tty_struct *tty = port->state->port.tty;
786 	struct sci_port *s = to_sci_port(port);
787 
788 	if (uart_handle_break(port))
789 		return 0;
790 
791 	if (!s->break_flag && status & SCxSR_BRK(port)) {
792 #if defined(CONFIG_CPU_SH3)
793 		/* Debounce break */
794 		s->break_flag = 1;
795 #endif
796 		/* Notify of BREAK */
797 		if (tty_insert_flip_char(tty, 0, TTY_BREAK))
798 			copied++;
799 
800 		dev_dbg(port->dev, "BREAK detected\n");
801 	}
802 
803 	if (copied)
804 		tty_flip_buffer_push(tty);
805 
806 	copied += sci_handle_fifo_overrun(port);
807 
808 	return copied;
809 }
810 
811 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
812 {
813 #ifdef CONFIG_SERIAL_SH_SCI_DMA
814 	struct uart_port *port = ptr;
815 	struct sci_port *s = to_sci_port(port);
816 
817 	if (s->chan_rx) {
818 		u16 scr = sci_in(port, SCSCR);
819 		u16 ssr = sci_in(port, SCxSR);
820 
821 		/* Disable future Rx interrupts */
822 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
823 			disable_irq_nosync(irq);
824 			scr |= 0x4000;
825 		} else {
826 			scr &= ~SCSCR_RIE;
827 		}
828 		sci_out(port, SCSCR, scr);
829 		/* Clear current interrupt */
830 		sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
831 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
832 			jiffies, s->rx_timeout);
833 		mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
834 
835 		return IRQ_HANDLED;
836 	}
837 #endif
838 
839 	/* I think sci_receive_chars has to be called irrespective
840 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
841 	 * to be disabled?
842 	 */
843 	sci_receive_chars(ptr);
844 
845 	return IRQ_HANDLED;
846 }
847 
848 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
849 {
850 	struct uart_port *port = ptr;
851 	unsigned long flags;
852 
853 	spin_lock_irqsave(&port->lock, flags);
854 	sci_transmit_chars(port);
855 	spin_unlock_irqrestore(&port->lock, flags);
856 
857 	return IRQ_HANDLED;
858 }
859 
860 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
861 {
862 	struct uart_port *port = ptr;
863 
864 	/* Handle errors */
865 	if (port->type == PORT_SCI) {
866 		if (sci_handle_errors(port)) {
867 			/* discard character in rx buffer */
868 			sci_in(port, SCxSR);
869 			sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
870 		}
871 	} else {
872 		sci_handle_fifo_overrun(port);
873 		sci_rx_interrupt(irq, ptr);
874 	}
875 
876 	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
877 
878 	/* Kick the transmission */
879 	sci_tx_interrupt(irq, ptr);
880 
881 	return IRQ_HANDLED;
882 }
883 
884 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
885 {
886 	struct uart_port *port = ptr;
887 
888 	/* Handle BREAKs */
889 	sci_handle_breaks(port);
890 	sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
891 
892 	return IRQ_HANDLED;
893 }
894 
895 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
896 {
897 	/*
898 	 * Not all ports (such as SCIFA) will support REIE. Rather than
899 	 * special-casing the port type, we check the port initialization
900 	 * IRQ enable mask to see whether the IRQ is desired at all. If
901 	 * it's unset, it's logically inferred that there's no point in
902 	 * testing for it.
903 	 */
904 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
905 }
906 
907 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
908 {
909 	unsigned short ssr_status, scr_status, err_enabled;
910 	struct uart_port *port = ptr;
911 	struct sci_port *s = to_sci_port(port);
912 	irqreturn_t ret = IRQ_NONE;
913 
914 	ssr_status = sci_in(port, SCxSR);
915 	scr_status = sci_in(port, SCSCR);
916 	err_enabled = scr_status & port_rx_irq_mask(port);
917 
918 	/* Tx Interrupt */
919 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
920 	    !s->chan_tx)
921 		ret = sci_tx_interrupt(irq, ptr);
922 
923 	/*
924 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
925 	 * DR flags
926 	 */
927 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
928 	    (scr_status & SCSCR_RIE))
929 		ret = sci_rx_interrupt(irq, ptr);
930 
931 	/* Error Interrupt */
932 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
933 		ret = sci_er_interrupt(irq, ptr);
934 
935 	/* Break Interrupt */
936 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
937 		ret = sci_br_interrupt(irq, ptr);
938 
939 	return ret;
940 }
941 
942 /*
943  * Here we define a transition notifier so that we can update all of our
944  * ports' baud rate when the peripheral clock changes.
945  */
946 static int sci_notifier(struct notifier_block *self,
947 			unsigned long phase, void *p)
948 {
949 	struct sci_port *sci_port;
950 	unsigned long flags;
951 
952 	sci_port = container_of(self, struct sci_port, freq_transition);
953 
954 	if ((phase == CPUFREQ_POSTCHANGE) ||
955 	    (phase == CPUFREQ_RESUMECHANGE)) {
956 		struct uart_port *port = &sci_port->port;
957 
958 		spin_lock_irqsave(&port->lock, flags);
959 		port->uartclk = clk_get_rate(sci_port->iclk);
960 		spin_unlock_irqrestore(&port->lock, flags);
961 	}
962 
963 	return NOTIFY_OK;
964 }
965 
966 static struct sci_irq_desc {
967 	const char	*desc;
968 	irq_handler_t	handler;
969 } sci_irq_desc[] = {
970 	/*
971 	 * Split out handlers, the default case.
972 	 */
973 	[SCIx_ERI_IRQ] = {
974 		.desc = "rx err",
975 		.handler = sci_er_interrupt,
976 	},
977 
978 	[SCIx_RXI_IRQ] = {
979 		.desc = "rx full",
980 		.handler = sci_rx_interrupt,
981 	},
982 
983 	[SCIx_TXI_IRQ] = {
984 		.desc = "tx empty",
985 		.handler = sci_tx_interrupt,
986 	},
987 
988 	[SCIx_BRI_IRQ] = {
989 		.desc = "break",
990 		.handler = sci_br_interrupt,
991 	},
992 
993 	/*
994 	 * Special muxed handler.
995 	 */
996 	[SCIx_MUX_IRQ] = {
997 		.desc = "mux",
998 		.handler = sci_mpxed_interrupt,
999 	},
1000 };
1001 
1002 static int sci_request_irq(struct sci_port *port)
1003 {
1004 	struct uart_port *up = &port->port;
1005 	int i, j, ret = 0;
1006 
1007 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1008 		struct sci_irq_desc *desc;
1009 		unsigned int irq;
1010 
1011 		if (SCIx_IRQ_IS_MUXED(port)) {
1012 			i = SCIx_MUX_IRQ;
1013 			irq = up->irq;
1014 		} else
1015 			irq = port->cfg->irqs[i];
1016 
1017 		desc = sci_irq_desc + i;
1018 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1019 					    dev_name(up->dev), desc->desc);
1020 		if (!port->irqstr[j]) {
1021 			dev_err(up->dev, "Failed to allocate %s IRQ string\n",
1022 				desc->desc);
1023 			goto out_nomem;
1024 		}
1025 
1026 		ret = request_irq(irq, desc->handler, up->irqflags,
1027 				  port->irqstr[j], port);
1028 		if (unlikely(ret)) {
1029 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1030 			goto out_noirq;
1031 		}
1032 	}
1033 
1034 	return 0;
1035 
1036 out_noirq:
1037 	while (--i >= 0)
1038 		free_irq(port->cfg->irqs[i], port);
1039 
1040 out_nomem:
1041 	while (--j >= 0)
1042 		kfree(port->irqstr[j]);
1043 
1044 	return ret;
1045 }
1046 
1047 static void sci_free_irq(struct sci_port *port)
1048 {
1049 	int i;
1050 
1051 	/*
1052 	 * Intentionally in reverse order so we iterate over the muxed
1053 	 * IRQ first.
1054 	 */
1055 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1056 		free_irq(port->cfg->irqs[i], port);
1057 		kfree(port->irqstr[i]);
1058 
1059 		if (SCIx_IRQ_IS_MUXED(port)) {
1060 			/* If there's only one IRQ, we're done. */
1061 			return;
1062 		}
1063 	}
1064 }
1065 
1066 static unsigned int sci_tx_empty(struct uart_port *port)
1067 {
1068 	unsigned short status = sci_in(port, SCxSR);
1069 	unsigned short in_tx_fifo = sci_txfill(port);
1070 
1071 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1072 }
1073 
1074 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1075 {
1076 	/* This routine is used for seting signals of: DTR, DCD, CTS/RTS */
1077 	/* We use SCIF's hardware for CTS/RTS, so don't need any for that. */
1078 	/* If you have signals for DTR and DCD, please implement here. */
1079 }
1080 
1081 static unsigned int sci_get_mctrl(struct uart_port *port)
1082 {
1083 	/* This routine is used for getting signals of: DTR, DCD, DSR, RI,
1084 	   and CTS/RTS */
1085 
1086 	return TIOCM_DTR | TIOCM_RTS | TIOCM_CTS | TIOCM_DSR;
1087 }
1088 
1089 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1090 static void sci_dma_tx_complete(void *arg)
1091 {
1092 	struct sci_port *s = arg;
1093 	struct uart_port *port = &s->port;
1094 	struct circ_buf *xmit = &port->state->xmit;
1095 	unsigned long flags;
1096 
1097 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1098 
1099 	spin_lock_irqsave(&port->lock, flags);
1100 
1101 	xmit->tail += sg_dma_len(&s->sg_tx);
1102 	xmit->tail &= UART_XMIT_SIZE - 1;
1103 
1104 	port->icount.tx += sg_dma_len(&s->sg_tx);
1105 
1106 	async_tx_ack(s->desc_tx);
1107 	s->cookie_tx = -EINVAL;
1108 	s->desc_tx = NULL;
1109 
1110 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1111 		uart_write_wakeup(port);
1112 
1113 	if (!uart_circ_empty(xmit)) {
1114 		schedule_work(&s->work_tx);
1115 	} else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1116 		u16 ctrl = sci_in(port, SCSCR);
1117 		sci_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1118 	}
1119 
1120 	spin_unlock_irqrestore(&port->lock, flags);
1121 }
1122 
1123 /* Locking: called with port lock held */
1124 static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,
1125 			   size_t count)
1126 {
1127 	struct uart_port *port = &s->port;
1128 	int i, active, room;
1129 
1130 	room = tty_buffer_request_room(tty, count);
1131 
1132 	if (s->active_rx == s->cookie_rx[0]) {
1133 		active = 0;
1134 	} else if (s->active_rx == s->cookie_rx[1]) {
1135 		active = 1;
1136 	} else {
1137 		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1138 		return 0;
1139 	}
1140 
1141 	if (room < count)
1142 		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
1143 			 count - room);
1144 	if (!room)
1145 		return room;
1146 
1147 	for (i = 0; i < room; i++)
1148 		tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
1149 				     TTY_NORMAL);
1150 
1151 	port->icount.rx += room;
1152 
1153 	return room;
1154 }
1155 
1156 static void sci_dma_rx_complete(void *arg)
1157 {
1158 	struct sci_port *s = arg;
1159 	struct uart_port *port = &s->port;
1160 	struct tty_struct *tty = port->state->port.tty;
1161 	unsigned long flags;
1162 	int count;
1163 
1164 	dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
1165 
1166 	spin_lock_irqsave(&port->lock, flags);
1167 
1168 	count = sci_dma_rx_push(s, tty, s->buf_len_rx);
1169 
1170 	mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1171 
1172 	spin_unlock_irqrestore(&port->lock, flags);
1173 
1174 	if (count)
1175 		tty_flip_buffer_push(tty);
1176 
1177 	schedule_work(&s->work_rx);
1178 }
1179 
1180 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1181 {
1182 	struct dma_chan *chan = s->chan_rx;
1183 	struct uart_port *port = &s->port;
1184 
1185 	s->chan_rx = NULL;
1186 	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1187 	dma_release_channel(chan);
1188 	if (sg_dma_address(&s->sg_rx[0]))
1189 		dma_free_coherent(port->dev, s->buf_len_rx * 2,
1190 				  sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
1191 	if (enable_pio)
1192 		sci_start_rx(port);
1193 }
1194 
1195 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1196 {
1197 	struct dma_chan *chan = s->chan_tx;
1198 	struct uart_port *port = &s->port;
1199 
1200 	s->chan_tx = NULL;
1201 	s->cookie_tx = -EINVAL;
1202 	dma_release_channel(chan);
1203 	if (enable_pio)
1204 		sci_start_tx(port);
1205 }
1206 
1207 static void sci_submit_rx(struct sci_port *s)
1208 {
1209 	struct dma_chan *chan = s->chan_rx;
1210 	int i;
1211 
1212 	for (i = 0; i < 2; i++) {
1213 		struct scatterlist *sg = &s->sg_rx[i];
1214 		struct dma_async_tx_descriptor *desc;
1215 
1216 		desc = chan->device->device_prep_slave_sg(chan,
1217 			sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);
1218 
1219 		if (desc) {
1220 			s->desc_rx[i] = desc;
1221 			desc->callback = sci_dma_rx_complete;
1222 			desc->callback_param = s;
1223 			s->cookie_rx[i] = desc->tx_submit(desc);
1224 		}
1225 
1226 		if (!desc || s->cookie_rx[i] < 0) {
1227 			if (i) {
1228 				async_tx_ack(s->desc_rx[0]);
1229 				s->cookie_rx[0] = -EINVAL;
1230 			}
1231 			if (desc) {
1232 				async_tx_ack(desc);
1233 				s->cookie_rx[i] = -EINVAL;
1234 			}
1235 			dev_warn(s->port.dev,
1236 				 "failed to re-start DMA, using PIO\n");
1237 			sci_rx_dma_release(s, true);
1238 			return;
1239 		}
1240 		dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1241 			s->cookie_rx[i], i);
1242 	}
1243 
1244 	s->active_rx = s->cookie_rx[0];
1245 
1246 	dma_async_issue_pending(chan);
1247 }
1248 
1249 static void work_fn_rx(struct work_struct *work)
1250 {
1251 	struct sci_port *s = container_of(work, struct sci_port, work_rx);
1252 	struct uart_port *port = &s->port;
1253 	struct dma_async_tx_descriptor *desc;
1254 	int new;
1255 
1256 	if (s->active_rx == s->cookie_rx[0]) {
1257 		new = 0;
1258 	} else if (s->active_rx == s->cookie_rx[1]) {
1259 		new = 1;
1260 	} else {
1261 		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1262 		return;
1263 	}
1264 	desc = s->desc_rx[new];
1265 
1266 	if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
1267 	    DMA_SUCCESS) {
1268 		/* Handle incomplete DMA receive */
1269 		struct tty_struct *tty = port->state->port.tty;
1270 		struct dma_chan *chan = s->chan_rx;
1271 		struct sh_desc *sh_desc = container_of(desc, struct sh_desc,
1272 						       async_tx);
1273 		unsigned long flags;
1274 		int count;
1275 
1276 		chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
1277 		dev_dbg(port->dev, "Read %u bytes with cookie %d\n",
1278 			sh_desc->partial, sh_desc->cookie);
1279 
1280 		spin_lock_irqsave(&port->lock, flags);
1281 		count = sci_dma_rx_push(s, tty, sh_desc->partial);
1282 		spin_unlock_irqrestore(&port->lock, flags);
1283 
1284 		if (count)
1285 			tty_flip_buffer_push(tty);
1286 
1287 		sci_submit_rx(s);
1288 
1289 		return;
1290 	}
1291 
1292 	s->cookie_rx[new] = desc->tx_submit(desc);
1293 	if (s->cookie_rx[new] < 0) {
1294 		dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1295 		sci_rx_dma_release(s, true);
1296 		return;
1297 	}
1298 
1299 	s->active_rx = s->cookie_rx[!new];
1300 
1301 	dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
1302 		s->cookie_rx[new], new, s->active_rx);
1303 }
1304 
1305 static void work_fn_tx(struct work_struct *work)
1306 {
1307 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1308 	struct dma_async_tx_descriptor *desc;
1309 	struct dma_chan *chan = s->chan_tx;
1310 	struct uart_port *port = &s->port;
1311 	struct circ_buf *xmit = &port->state->xmit;
1312 	struct scatterlist *sg = &s->sg_tx;
1313 
1314 	/*
1315 	 * DMA is idle now.
1316 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1317 	 * offsets and lengths. Since it is a circular buffer, we have to
1318 	 * transmit till the end, and then the rest. Take the port lock to get a
1319 	 * consistent xmit buffer state.
1320 	 */
1321 	spin_lock_irq(&port->lock);
1322 	sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
1323 	sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
1324 		sg->offset;
1325 	sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1326 		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1327 	spin_unlock_irq(&port->lock);
1328 
1329 	BUG_ON(!sg_dma_len(sg));
1330 
1331 	desc = chan->device->device_prep_slave_sg(chan,
1332 			sg, s->sg_len_tx, DMA_TO_DEVICE,
1333 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1334 	if (!desc) {
1335 		/* switch to PIO */
1336 		sci_tx_dma_release(s, true);
1337 		return;
1338 	}
1339 
1340 	dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
1341 
1342 	spin_lock_irq(&port->lock);
1343 	s->desc_tx = desc;
1344 	desc->callback = sci_dma_tx_complete;
1345 	desc->callback_param = s;
1346 	spin_unlock_irq(&port->lock);
1347 	s->cookie_tx = desc->tx_submit(desc);
1348 	if (s->cookie_tx < 0) {
1349 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1350 		/* switch to PIO */
1351 		sci_tx_dma_release(s, true);
1352 		return;
1353 	}
1354 
1355 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,
1356 		xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1357 
1358 	dma_async_issue_pending(chan);
1359 }
1360 #endif
1361 
1362 static void sci_start_tx(struct uart_port *port)
1363 {
1364 	struct sci_port *s = to_sci_port(port);
1365 	unsigned short ctrl;
1366 
1367 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1368 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1369 		u16 new, scr = sci_in(port, SCSCR);
1370 		if (s->chan_tx)
1371 			new = scr | 0x8000;
1372 		else
1373 			new = scr & ~0x8000;
1374 		if (new != scr)
1375 			sci_out(port, SCSCR, new);
1376 	}
1377 
1378 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
1379 	    s->cookie_tx < 0)
1380 		schedule_work(&s->work_tx);
1381 #endif
1382 
1383 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1384 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
1385 		ctrl = sci_in(port, SCSCR);
1386 		sci_out(port, SCSCR, ctrl | SCSCR_TIE);
1387 	}
1388 }
1389 
1390 static void sci_stop_tx(struct uart_port *port)
1391 {
1392 	unsigned short ctrl;
1393 
1394 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
1395 	ctrl = sci_in(port, SCSCR);
1396 
1397 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1398 		ctrl &= ~0x8000;
1399 
1400 	ctrl &= ~SCSCR_TIE;
1401 
1402 	sci_out(port, SCSCR, ctrl);
1403 }
1404 
1405 static void sci_start_rx(struct uart_port *port)
1406 {
1407 	unsigned short ctrl;
1408 
1409 	ctrl = sci_in(port, SCSCR) | port_rx_irq_mask(port);
1410 
1411 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1412 		ctrl &= ~0x4000;
1413 
1414 	sci_out(port, SCSCR, ctrl);
1415 }
1416 
1417 static void sci_stop_rx(struct uart_port *port)
1418 {
1419 	unsigned short ctrl;
1420 
1421 	ctrl = sci_in(port, SCSCR);
1422 
1423 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1424 		ctrl &= ~0x4000;
1425 
1426 	ctrl &= ~port_rx_irq_mask(port);
1427 
1428 	sci_out(port, SCSCR, ctrl);
1429 }
1430 
1431 static void sci_enable_ms(struct uart_port *port)
1432 {
1433 	/* Nothing here yet .. */
1434 }
1435 
1436 static void sci_break_ctl(struct uart_port *port, int break_state)
1437 {
1438 	/* Nothing here yet .. */
1439 }
1440 
1441 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1442 static bool filter(struct dma_chan *chan, void *slave)
1443 {
1444 	struct sh_dmae_slave *param = slave;
1445 
1446 	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
1447 		param->slave_id);
1448 
1449 	if (param->dma_dev == chan->device->dev) {
1450 		chan->private = param;
1451 		return true;
1452 	} else {
1453 		return false;
1454 	}
1455 }
1456 
1457 static void rx_timer_fn(unsigned long arg)
1458 {
1459 	struct sci_port *s = (struct sci_port *)arg;
1460 	struct uart_port *port = &s->port;
1461 	u16 scr = sci_in(port, SCSCR);
1462 
1463 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1464 		scr &= ~0x4000;
1465 		enable_irq(s->cfg->irqs[1]);
1466 	}
1467 	sci_out(port, SCSCR, scr | SCSCR_RIE);
1468 	dev_dbg(port->dev, "DMA Rx timed out\n");
1469 	schedule_work(&s->work_rx);
1470 }
1471 
1472 static void sci_request_dma(struct uart_port *port)
1473 {
1474 	struct sci_port *s = to_sci_port(port);
1475 	struct sh_dmae_slave *param;
1476 	struct dma_chan *chan;
1477 	dma_cap_mask_t mask;
1478 	int nent;
1479 
1480 	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
1481 		port->line, s->cfg->dma_dev);
1482 
1483 	if (!s->cfg->dma_dev)
1484 		return;
1485 
1486 	dma_cap_zero(mask);
1487 	dma_cap_set(DMA_SLAVE, mask);
1488 
1489 	param = &s->param_tx;
1490 
1491 	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
1492 	param->slave_id = s->cfg->dma_slave_tx;
1493 	param->dma_dev = s->cfg->dma_dev;
1494 
1495 	s->cookie_tx = -EINVAL;
1496 	chan = dma_request_channel(mask, filter, param);
1497 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1498 	if (chan) {
1499 		s->chan_tx = chan;
1500 		sg_init_table(&s->sg_tx, 1);
1501 		/* UART circular tx buffer is an aligned page. */
1502 		BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);
1503 		sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
1504 			    UART_XMIT_SIZE, (int)port->state->xmit.buf & ~PAGE_MASK);
1505 		nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
1506 		if (!nent)
1507 			sci_tx_dma_release(s, false);
1508 		else
1509 			dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
1510 				sg_dma_len(&s->sg_tx),
1511 				port->state->xmit.buf, sg_dma_address(&s->sg_tx));
1512 
1513 		s->sg_len_tx = nent;
1514 
1515 		INIT_WORK(&s->work_tx, work_fn_tx);
1516 	}
1517 
1518 	param = &s->param_rx;
1519 
1520 	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
1521 	param->slave_id = s->cfg->dma_slave_rx;
1522 	param->dma_dev = s->cfg->dma_dev;
1523 
1524 	chan = dma_request_channel(mask, filter, param);
1525 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1526 	if (chan) {
1527 		dma_addr_t dma[2];
1528 		void *buf[2];
1529 		int i;
1530 
1531 		s->chan_rx = chan;
1532 
1533 		s->buf_len_rx = 2 * max(16, (int)port->fifosize);
1534 		buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
1535 					    &dma[0], GFP_KERNEL);
1536 
1537 		if (!buf[0]) {
1538 			dev_warn(port->dev,
1539 				 "failed to allocate dma buffer, using PIO\n");
1540 			sci_rx_dma_release(s, true);
1541 			return;
1542 		}
1543 
1544 		buf[1] = buf[0] + s->buf_len_rx;
1545 		dma[1] = dma[0] + s->buf_len_rx;
1546 
1547 		for (i = 0; i < 2; i++) {
1548 			struct scatterlist *sg = &s->sg_rx[i];
1549 
1550 			sg_init_table(sg, 1);
1551 			sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
1552 				    (int)buf[i] & ~PAGE_MASK);
1553 			sg_dma_address(sg) = dma[i];
1554 		}
1555 
1556 		INIT_WORK(&s->work_rx, work_fn_rx);
1557 		setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1558 
1559 		sci_submit_rx(s);
1560 	}
1561 }
1562 
1563 static void sci_free_dma(struct uart_port *port)
1564 {
1565 	struct sci_port *s = to_sci_port(port);
1566 
1567 	if (!s->cfg->dma_dev)
1568 		return;
1569 
1570 	if (s->chan_tx)
1571 		sci_tx_dma_release(s, false);
1572 	if (s->chan_rx)
1573 		sci_rx_dma_release(s, false);
1574 }
1575 #else
1576 static inline void sci_request_dma(struct uart_port *port)
1577 {
1578 }
1579 
1580 static inline void sci_free_dma(struct uart_port *port)
1581 {
1582 }
1583 #endif
1584 
1585 static int sci_startup(struct uart_port *port)
1586 {
1587 	struct sci_port *s = to_sci_port(port);
1588 	int ret;
1589 
1590 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1591 
1592 	sci_port_enable(s);
1593 
1594 	ret = sci_request_irq(s);
1595 	if (unlikely(ret < 0))
1596 		return ret;
1597 
1598 	sci_request_dma(port);
1599 
1600 	sci_start_tx(port);
1601 	sci_start_rx(port);
1602 
1603 	return 0;
1604 }
1605 
1606 static void sci_shutdown(struct uart_port *port)
1607 {
1608 	struct sci_port *s = to_sci_port(port);
1609 
1610 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1611 
1612 	sci_stop_rx(port);
1613 	sci_stop_tx(port);
1614 
1615 	sci_free_dma(port);
1616 	sci_free_irq(s);
1617 
1618 	sci_port_disable(s);
1619 }
1620 
1621 static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps,
1622 				   unsigned long freq)
1623 {
1624 	switch (algo_id) {
1625 	case SCBRR_ALGO_1:
1626 		return ((freq + 16 * bps) / (16 * bps) - 1);
1627 	case SCBRR_ALGO_2:
1628 		return ((freq + 16 * bps) / (32 * bps) - 1);
1629 	case SCBRR_ALGO_3:
1630 		return (((freq * 2) + 16 * bps) / (16 * bps) - 1);
1631 	case SCBRR_ALGO_4:
1632 		return (((freq * 2) + 16 * bps) / (32 * bps) - 1);
1633 	case SCBRR_ALGO_5:
1634 		return (((freq * 1000 / 32) / bps) - 1);
1635 	}
1636 
1637 	/* Warn, but use a safe default */
1638 	WARN_ON(1);
1639 
1640 	return ((freq + 16 * bps) / (32 * bps) - 1);
1641 }
1642 
1643 static void sci_reset(struct uart_port *port)
1644 {
1645 	unsigned int status;
1646 
1647 	do {
1648 		status = sci_in(port, SCxSR);
1649 	} while (!(status & SCxSR_TEND(port)));
1650 
1651 	sci_out(port, SCSCR, 0x00);	/* TE=0, RE=0, CKE1=0 */
1652 
1653 	if (port->type != PORT_SCI)
1654 		sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
1655 }
1656 
1657 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
1658 			    struct ktermios *old)
1659 {
1660 	struct sci_port *s = to_sci_port(port);
1661 	unsigned int baud, smr_val, max_baud;
1662 	int t = -1;
1663 	u16 scfcr = 0;
1664 
1665 	/*
1666 	 * earlyprintk comes here early on with port->uartclk set to zero.
1667 	 * the clock framework is not up and running at this point so here
1668 	 * we assume that 115200 is the maximum baud rate. please note that
1669 	 * the baud rate is not programmed during earlyprintk - it is assumed
1670 	 * that the previous boot loader has enabled required clocks and
1671 	 * setup the baud rate generator hardware for us already.
1672 	 */
1673 	max_baud = port->uartclk ? port->uartclk / 16 : 115200;
1674 
1675 	baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
1676 	if (likely(baud && port->uartclk))
1677 		t = sci_scbrr_calc(s->cfg->scbrr_algo_id, baud, port->uartclk);
1678 
1679 	sci_port_enable(s);
1680 
1681 	sci_reset(port);
1682 
1683 	smr_val = sci_in(port, SCSMR) & 3;
1684 
1685 	if ((termios->c_cflag & CSIZE) == CS7)
1686 		smr_val |= 0x40;
1687 	if (termios->c_cflag & PARENB)
1688 		smr_val |= 0x20;
1689 	if (termios->c_cflag & PARODD)
1690 		smr_val |= 0x30;
1691 	if (termios->c_cflag & CSTOPB)
1692 		smr_val |= 0x08;
1693 
1694 	uart_update_timeout(port, termios->c_cflag, baud);
1695 
1696 	sci_out(port, SCSMR, smr_val);
1697 
1698 	dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,
1699 		s->cfg->scscr);
1700 
1701 	if (t > 0) {
1702 		if (t >= 256) {
1703 			sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
1704 			t >>= 2;
1705 		} else
1706 			sci_out(port, SCSMR, sci_in(port, SCSMR) & ~3);
1707 
1708 		sci_out(port, SCBRR, t);
1709 		udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
1710 	}
1711 
1712 	sci_init_pins(port, termios->c_cflag);
1713 	sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
1714 
1715 	sci_out(port, SCSCR, s->cfg->scscr);
1716 
1717 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1718 	/*
1719 	 * Calculate delay for 1.5 DMA buffers: see
1720 	 * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
1721 	 * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
1722 	 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
1723 	 * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
1724 	 * sizes), but it has been found out experimentally, that this is not
1725 	 * enough: the driver too often needlessly runs on a DMA timeout. 20ms
1726 	 * as a minimum seem to work perfectly.
1727 	 */
1728 	if (s->chan_rx) {
1729 		s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
1730 			port->fifosize / 2;
1731 		dev_dbg(port->dev,
1732 			"DMA Rx t-out %ums, tty t-out %u jiffies\n",
1733 			s->rx_timeout * 1000 / HZ, port->timeout);
1734 		if (s->rx_timeout < msecs_to_jiffies(20))
1735 			s->rx_timeout = msecs_to_jiffies(20);
1736 	}
1737 #endif
1738 
1739 	if ((termios->c_cflag & CREAD) != 0)
1740 		sci_start_rx(port);
1741 
1742 	sci_port_disable(s);
1743 }
1744 
1745 static const char *sci_type(struct uart_port *port)
1746 {
1747 	switch (port->type) {
1748 	case PORT_IRDA:
1749 		return "irda";
1750 	case PORT_SCI:
1751 		return "sci";
1752 	case PORT_SCIF:
1753 		return "scif";
1754 	case PORT_SCIFA:
1755 		return "scifa";
1756 	case PORT_SCIFB:
1757 		return "scifb";
1758 	}
1759 
1760 	return NULL;
1761 }
1762 
1763 static inline unsigned long sci_port_size(struct uart_port *port)
1764 {
1765 	/*
1766 	 * Pick an arbitrary size that encapsulates all of the base
1767 	 * registers by default. This can be optimized later, or derived
1768 	 * from platform resource data at such a time that ports begin to
1769 	 * behave more erratically.
1770 	 */
1771 	return 64;
1772 }
1773 
1774 static int sci_remap_port(struct uart_port *port)
1775 {
1776 	unsigned long size = sci_port_size(port);
1777 
1778 	/*
1779 	 * Nothing to do if there's already an established membase.
1780 	 */
1781 	if (port->membase)
1782 		return 0;
1783 
1784 	if (port->flags & UPF_IOREMAP) {
1785 		port->membase = ioremap_nocache(port->mapbase, size);
1786 		if (unlikely(!port->membase)) {
1787 			dev_err(port->dev, "can't remap port#%d\n", port->line);
1788 			return -ENXIO;
1789 		}
1790 	} else {
1791 		/*
1792 		 * For the simple (and majority of) cases where we don't
1793 		 * need to do any remapping, just cast the cookie
1794 		 * directly.
1795 		 */
1796 		port->membase = (void __iomem *)port->mapbase;
1797 	}
1798 
1799 	return 0;
1800 }
1801 
1802 static void sci_release_port(struct uart_port *port)
1803 {
1804 	if (port->flags & UPF_IOREMAP) {
1805 		iounmap(port->membase);
1806 		port->membase = NULL;
1807 	}
1808 
1809 	release_mem_region(port->mapbase, sci_port_size(port));
1810 }
1811 
1812 static int sci_request_port(struct uart_port *port)
1813 {
1814 	unsigned long size = sci_port_size(port);
1815 	struct resource *res;
1816 	int ret;
1817 
1818 	res = request_mem_region(port->mapbase, size, dev_name(port->dev));
1819 	if (unlikely(res == NULL))
1820 		return -EBUSY;
1821 
1822 	ret = sci_remap_port(port);
1823 	if (unlikely(ret != 0)) {
1824 		release_resource(res);
1825 		return ret;
1826 	}
1827 
1828 	return 0;
1829 }
1830 
1831 static void sci_config_port(struct uart_port *port, int flags)
1832 {
1833 	if (flags & UART_CONFIG_TYPE) {
1834 		struct sci_port *sport = to_sci_port(port);
1835 
1836 		port->type = sport->cfg->type;
1837 		sci_request_port(port);
1838 	}
1839 }
1840 
1841 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
1842 {
1843 	struct sci_port *s = to_sci_port(port);
1844 
1845 	if (ser->irq != s->cfg->irqs[SCIx_TXI_IRQ] || ser->irq > nr_irqs)
1846 		return -EINVAL;
1847 	if (ser->baud_base < 2400)
1848 		/* No paper tape reader for Mitch.. */
1849 		return -EINVAL;
1850 
1851 	return 0;
1852 }
1853 
1854 static struct uart_ops sci_uart_ops = {
1855 	.tx_empty	= sci_tx_empty,
1856 	.set_mctrl	= sci_set_mctrl,
1857 	.get_mctrl	= sci_get_mctrl,
1858 	.start_tx	= sci_start_tx,
1859 	.stop_tx	= sci_stop_tx,
1860 	.stop_rx	= sci_stop_rx,
1861 	.enable_ms	= sci_enable_ms,
1862 	.break_ctl	= sci_break_ctl,
1863 	.startup	= sci_startup,
1864 	.shutdown	= sci_shutdown,
1865 	.set_termios	= sci_set_termios,
1866 	.type		= sci_type,
1867 	.release_port	= sci_release_port,
1868 	.request_port	= sci_request_port,
1869 	.config_port	= sci_config_port,
1870 	.verify_port	= sci_verify_port,
1871 #ifdef CONFIG_CONSOLE_POLL
1872 	.poll_get_char	= sci_poll_get_char,
1873 	.poll_put_char	= sci_poll_put_char,
1874 #endif
1875 };
1876 
1877 static int __devinit sci_init_single(struct platform_device *dev,
1878 				     struct sci_port *sci_port,
1879 				     unsigned int index,
1880 				     struct plat_sci_port *p)
1881 {
1882 	struct uart_port *port = &sci_port->port;
1883 	int ret;
1884 
1885 	port->ops	= &sci_uart_ops;
1886 	port->iotype	= UPIO_MEM;
1887 	port->line	= index;
1888 
1889 	switch (p->type) {
1890 	case PORT_SCIFB:
1891 		port->fifosize = 256;
1892 		break;
1893 	case PORT_SCIFA:
1894 		port->fifosize = 64;
1895 		break;
1896 	case PORT_SCIF:
1897 		port->fifosize = 16;
1898 		break;
1899 	default:
1900 		port->fifosize = 1;
1901 		break;
1902 	}
1903 
1904 	if (p->regtype == SCIx_PROBE_REGTYPE) {
1905 		ret = sci_probe_regmap(p);
1906 		if (unlikely(ret))
1907 			return ret;
1908 	}
1909 
1910 	if (dev) {
1911 		sci_port->iclk = clk_get(&dev->dev, "sci_ick");
1912 		if (IS_ERR(sci_port->iclk)) {
1913 			sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
1914 			if (IS_ERR(sci_port->iclk)) {
1915 				dev_err(&dev->dev, "can't get iclk\n");
1916 				return PTR_ERR(sci_port->iclk);
1917 			}
1918 		}
1919 
1920 		/*
1921 		 * The function clock is optional, ignore it if we can't
1922 		 * find it.
1923 		 */
1924 		sci_port->fclk = clk_get(&dev->dev, "sci_fck");
1925 		if (IS_ERR(sci_port->fclk))
1926 			sci_port->fclk = NULL;
1927 
1928 		port->dev = &dev->dev;
1929 
1930 		pm_runtime_irq_safe(&dev->dev);
1931 		pm_runtime_enable(&dev->dev);
1932 	}
1933 
1934 	sci_port->break_timer.data = (unsigned long)sci_port;
1935 	sci_port->break_timer.function = sci_break_timer;
1936 	init_timer(&sci_port->break_timer);
1937 
1938 	/*
1939 	 * Establish some sensible defaults for the error detection.
1940 	 */
1941 	if (!p->error_mask)
1942 		p->error_mask = (p->type == PORT_SCI) ?
1943 			SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK;
1944 
1945 	/*
1946 	 * Establish sensible defaults for the overrun detection, unless
1947 	 * the part has explicitly disabled support for it.
1948 	 */
1949 	if (p->overrun_bit != SCIx_NOT_SUPPORTED) {
1950 		if (p->type == PORT_SCI)
1951 			p->overrun_bit = 5;
1952 		else if (p->scbrr_algo_id == SCBRR_ALGO_4)
1953 			p->overrun_bit = 9;
1954 		else
1955 			p->overrun_bit = 0;
1956 
1957 		/*
1958 		 * Make the error mask inclusive of overrun detection, if
1959 		 * supported.
1960 		 */
1961 		p->error_mask |= (1 << p->overrun_bit);
1962 	}
1963 
1964 	sci_port->cfg		= p;
1965 
1966 	port->mapbase		= p->mapbase;
1967 	port->type		= p->type;
1968 	port->flags		= p->flags;
1969 	port->regshift		= p->regshift;
1970 
1971 	/*
1972 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
1973 	 * for the multi-IRQ ports, which is where we are primarily
1974 	 * concerned with the shutdown path synchronization.
1975 	 *
1976 	 * For the muxed case there's nothing more to do.
1977 	 */
1978 	port->irq		= p->irqs[SCIx_RXI_IRQ];
1979 	port->irqflags		= IRQF_DISABLED;
1980 
1981 	port->serial_in		= sci_serial_in;
1982 	port->serial_out	= sci_serial_out;
1983 
1984 	if (p->dma_dev)
1985 		dev_dbg(port->dev, "DMA device %p, tx %d, rx %d\n",
1986 			p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
1987 
1988 	return 0;
1989 }
1990 
1991 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
1992 static void serial_console_putchar(struct uart_port *port, int ch)
1993 {
1994 	sci_poll_put_char(port, ch);
1995 }
1996 
1997 /*
1998  *	Print a string to the serial port trying not to disturb
1999  *	any possible real use of the port...
2000  */
2001 static void serial_console_write(struct console *co, const char *s,
2002 				 unsigned count)
2003 {
2004 	struct sci_port *sci_port = &sci_ports[co->index];
2005 	struct uart_port *port = &sci_port->port;
2006 	unsigned short bits;
2007 
2008 	sci_port_enable(sci_port);
2009 
2010 	uart_console_write(port, s, count, serial_console_putchar);
2011 
2012 	/* wait until fifo is empty and last bit has been transmitted */
2013 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2014 	while ((sci_in(port, SCxSR) & bits) != bits)
2015 		cpu_relax();
2016 
2017 	sci_port_disable(sci_port);
2018 }
2019 
2020 static int __devinit serial_console_setup(struct console *co, char *options)
2021 {
2022 	struct sci_port *sci_port;
2023 	struct uart_port *port;
2024 	int baud = 115200;
2025 	int bits = 8;
2026 	int parity = 'n';
2027 	int flow = 'n';
2028 	int ret;
2029 
2030 	/*
2031 	 * Refuse to handle any bogus ports.
2032 	 */
2033 	if (co->index < 0 || co->index >= SCI_NPORTS)
2034 		return -ENODEV;
2035 
2036 	sci_port = &sci_ports[co->index];
2037 	port = &sci_port->port;
2038 
2039 	/*
2040 	 * Refuse to handle uninitialized ports.
2041 	 */
2042 	if (!port->ops)
2043 		return -ENODEV;
2044 
2045 	ret = sci_remap_port(port);
2046 	if (unlikely(ret != 0))
2047 		return ret;
2048 
2049 	sci_port_enable(sci_port);
2050 
2051 	if (options)
2052 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2053 
2054 	sci_port_disable(sci_port);
2055 
2056 	return uart_set_options(port, co, baud, parity, bits, flow);
2057 }
2058 
2059 static struct console serial_console = {
2060 	.name		= "ttySC",
2061 	.device		= uart_console_device,
2062 	.write		= serial_console_write,
2063 	.setup		= serial_console_setup,
2064 	.flags		= CON_PRINTBUFFER,
2065 	.index		= -1,
2066 	.data		= &sci_uart_driver,
2067 };
2068 
2069 static struct console early_serial_console = {
2070 	.name           = "early_ttySC",
2071 	.write          = serial_console_write,
2072 	.flags          = CON_PRINTBUFFER,
2073 	.index		= -1,
2074 };
2075 
2076 static char early_serial_buf[32];
2077 
2078 static int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
2079 {
2080 	struct plat_sci_port *cfg = pdev->dev.platform_data;
2081 
2082 	if (early_serial_console.data)
2083 		return -EEXIST;
2084 
2085 	early_serial_console.index = pdev->id;
2086 
2087 	sci_init_single(NULL, &sci_ports[pdev->id], pdev->id, cfg);
2088 
2089 	serial_console_setup(&early_serial_console, early_serial_buf);
2090 
2091 	if (!strstr(early_serial_buf, "keep"))
2092 		early_serial_console.flags |= CON_BOOT;
2093 
2094 	register_console(&early_serial_console);
2095 	return 0;
2096 }
2097 
2098 #define uart_console(port)	((port)->cons->index == (port)->line)
2099 
2100 static int sci_runtime_suspend(struct device *dev)
2101 {
2102 	struct sci_port *sci_port = dev_get_drvdata(dev);
2103 	struct uart_port *port = &sci_port->port;
2104 
2105 	if (uart_console(port)) {
2106 		sci_port->saved_smr = sci_in(port, SCSMR);
2107 		sci_port->saved_brr = sci_in(port, SCBRR);
2108 		sci_port->saved_fcr = sci_in(port, SCFCR);
2109 	}
2110 	return 0;
2111 }
2112 
2113 static int sci_runtime_resume(struct device *dev)
2114 {
2115 	struct sci_port *sci_port = dev_get_drvdata(dev);
2116 	struct uart_port *port = &sci_port->port;
2117 
2118 	if (uart_console(port)) {
2119 		sci_reset(port);
2120 		sci_out(port, SCSMR, sci_port->saved_smr);
2121 		sci_out(port, SCBRR, sci_port->saved_brr);
2122 		sci_out(port, SCFCR, sci_port->saved_fcr);
2123 		sci_out(port, SCSCR, sci_port->cfg->scscr);
2124 	}
2125 	return 0;
2126 }
2127 
2128 #define SCI_CONSOLE	(&serial_console)
2129 
2130 #else
2131 static inline int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
2132 {
2133 	return -EINVAL;
2134 }
2135 
2136 #define SCI_CONSOLE	NULL
2137 #define sci_runtime_suspend	NULL
2138 #define sci_runtime_resume	NULL
2139 
2140 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
2141 
2142 static char banner[] __initdata =
2143 	KERN_INFO "SuperH SCI(F) driver initialized\n";
2144 
2145 static struct uart_driver sci_uart_driver = {
2146 	.owner		= THIS_MODULE,
2147 	.driver_name	= "sci",
2148 	.dev_name	= "ttySC",
2149 	.major		= SCI_MAJOR,
2150 	.minor		= SCI_MINOR_START,
2151 	.nr		= SCI_NPORTS,
2152 	.cons		= SCI_CONSOLE,
2153 };
2154 
2155 static int sci_remove(struct platform_device *dev)
2156 {
2157 	struct sci_port *port = platform_get_drvdata(dev);
2158 
2159 	cpufreq_unregister_notifier(&port->freq_transition,
2160 				    CPUFREQ_TRANSITION_NOTIFIER);
2161 
2162 	uart_remove_one_port(&sci_uart_driver, &port->port);
2163 
2164 	clk_put(port->iclk);
2165 	clk_put(port->fclk);
2166 
2167 	pm_runtime_disable(&dev->dev);
2168 	return 0;
2169 }
2170 
2171 static int __devinit sci_probe_single(struct platform_device *dev,
2172 				      unsigned int index,
2173 				      struct plat_sci_port *p,
2174 				      struct sci_port *sciport)
2175 {
2176 	int ret;
2177 
2178 	/* Sanity check */
2179 	if (unlikely(index >= SCI_NPORTS)) {
2180 		dev_notice(&dev->dev, "Attempting to register port "
2181 			   "%d when only %d are available.\n",
2182 			   index+1, SCI_NPORTS);
2183 		dev_notice(&dev->dev, "Consider bumping "
2184 			   "CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
2185 		return 0;
2186 	}
2187 
2188 	ret = sci_init_single(dev, sciport, index, p);
2189 	if (ret)
2190 		return ret;
2191 
2192 	return uart_add_one_port(&sci_uart_driver, &sciport->port);
2193 }
2194 
2195 static int __devinit sci_probe(struct platform_device *dev)
2196 {
2197 	struct plat_sci_port *p = dev->dev.platform_data;
2198 	struct sci_port *sp = &sci_ports[dev->id];
2199 	int ret;
2200 
2201 	/*
2202 	 * If we've come here via earlyprintk initialization, head off to
2203 	 * the special early probe. We don't have sufficient device state
2204 	 * to make it beyond this yet.
2205 	 */
2206 	if (is_early_platform_device(dev))
2207 		return sci_probe_earlyprintk(dev);
2208 
2209 	platform_set_drvdata(dev, sp);
2210 
2211 	ret = sci_probe_single(dev, dev->id, p, sp);
2212 	if (ret)
2213 		goto err_unreg;
2214 
2215 	sp->freq_transition.notifier_call = sci_notifier;
2216 
2217 	ret = cpufreq_register_notifier(&sp->freq_transition,
2218 					CPUFREQ_TRANSITION_NOTIFIER);
2219 	if (unlikely(ret < 0))
2220 		goto err_unreg;
2221 
2222 #ifdef CONFIG_SH_STANDARD_BIOS
2223 	sh_bios_gdb_detach();
2224 #endif
2225 
2226 	return 0;
2227 
2228 err_unreg:
2229 	sci_remove(dev);
2230 	return ret;
2231 }
2232 
2233 static int sci_suspend(struct device *dev)
2234 {
2235 	struct sci_port *sport = dev_get_drvdata(dev);
2236 
2237 	if (sport)
2238 		uart_suspend_port(&sci_uart_driver, &sport->port);
2239 
2240 	return 0;
2241 }
2242 
2243 static int sci_resume(struct device *dev)
2244 {
2245 	struct sci_port *sport = dev_get_drvdata(dev);
2246 
2247 	if (sport)
2248 		uart_resume_port(&sci_uart_driver, &sport->port);
2249 
2250 	return 0;
2251 }
2252 
2253 static const struct dev_pm_ops sci_dev_pm_ops = {
2254 	.runtime_suspend = sci_runtime_suspend,
2255 	.runtime_resume = sci_runtime_resume,
2256 	.suspend	= sci_suspend,
2257 	.resume		= sci_resume,
2258 };
2259 
2260 static struct platform_driver sci_driver = {
2261 	.probe		= sci_probe,
2262 	.remove		= sci_remove,
2263 	.driver		= {
2264 		.name	= "sh-sci",
2265 		.owner	= THIS_MODULE,
2266 		.pm	= &sci_dev_pm_ops,
2267 	},
2268 };
2269 
2270 static int __init sci_init(void)
2271 {
2272 	int ret;
2273 
2274 	printk(banner);
2275 
2276 	ret = uart_register_driver(&sci_uart_driver);
2277 	if (likely(ret == 0)) {
2278 		ret = platform_driver_register(&sci_driver);
2279 		if (unlikely(ret))
2280 			uart_unregister_driver(&sci_uart_driver);
2281 	}
2282 
2283 	return ret;
2284 }
2285 
2286 static void __exit sci_exit(void)
2287 {
2288 	platform_driver_unregister(&sci_driver);
2289 	uart_unregister_driver(&sci_uart_driver);
2290 }
2291 
2292 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2293 early_platform_init_buffer("earlyprintk", &sci_driver,
2294 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
2295 #endif
2296 module_init(sci_init);
2297 module_exit(sci_exit);
2298 
2299 MODULE_LICENSE("GPL");
2300 MODULE_ALIAS("platform:sh-sci");
2301 MODULE_AUTHOR("Paul Mundt");
2302 MODULE_DESCRIPTION("SuperH SCI(F) serial driver");
2303