Merge remote-tracking branch 'moduleh/module.h-split'
[linux-2.6/next.git] / drivers / tty / serial / sh-sci.c
blob5ea6ec3442e64d2affe5f54d9871f1561624c2f9
1 /*
2 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
4 * Copyright (C) 2002 - 2011 Paul Mundt
5 * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
7 * based off of the old drivers/char/sh-sci.c by:
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).
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.
20 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
21 #define SUPPORT_SYSRQ
22 #endif
24 #undef DEBUG
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>
54 #ifdef CONFIG_SUPERH
55 #include <asm/sh_bios.h>
56 #endif
58 #include "sh-sci.h"
60 struct sci_port {
61 struct uart_port port;
63 /* Platform configuration */
64 struct plat_sci_port *cfg;
66 /* Break timer */
67 struct timer_list break_timer;
68 int break_flag;
70 /* Interface clock */
71 struct clk *iclk;
72 /* Function clock */
73 struct clk *fclk;
75 char *irqstr[SCIx_NR_IRQS];
77 struct dma_chan *chan_tx;
78 struct dma_chan *chan_rx;
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
98 struct notifier_block freq_transition;
100 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
101 unsigned short saved_smr;
102 unsigned short saved_fcr;
103 unsigned char saved_brr;
104 #endif
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);
112 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
114 static struct sci_port sci_ports[SCI_NPORTS];
115 static struct uart_driver sci_uart_driver;
117 static inline struct sci_port *
118 to_sci_port(struct uart_port *uart)
120 return container_of(uart, struct sci_port, port);
123 struct plat_sci_reg {
124 u8 offset, size;
127 /* Helper for invalidating specific entries of an inherited map. */
128 #define sci_reg_invalid { .offset = 0, .size = 0 }
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,
136 * Common SCI definitions, dependent on the port's regshift
137 * value.
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,
155 * Common definitions for legacy IrDA ports, dependent on
156 * regshift value.
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,
174 * Common SCIFA definitions.
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,
192 * Common SCIFB definitions.
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,
210 * Common SH-3 SCIF definitions.
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,
228 * Common SH-4(A) SCIF(B) definitions.
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 },
246 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
247 * register.
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 },
265 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
266 * count registers.
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 },
284 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
285 * registers.
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,
303 #define sci_getreg(up, offset) (sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
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.
311 static unsigned int sci_serial_in(struct uart_port *p, int offset)
313 struct plat_sci_reg *reg = sci_getreg(p, offset);
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");
322 return 0;
325 static void sci_serial_out(struct uart_port *p, int offset, int value)
327 struct plat_sci_reg *reg = sci_getreg(p, offset);
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");
337 #define sci_in(up, offset) (up->serial_in(up, offset))
338 #define sci_out(up, offset, value) (up->serial_out(up, offset, value))
340 static int sci_probe_regmap(struct plat_sci_port *cfg)
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:
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.
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;
369 return 0;
372 static void sci_port_enable(struct sci_port *sci_port)
374 if (!sci_port->port.dev)
375 return;
377 pm_runtime_get_sync(sci_port->port.dev);
379 clk_enable(sci_port->iclk);
380 sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
381 clk_enable(sci_port->fclk);
384 static void sci_port_disable(struct sci_port *sci_port)
386 if (!sci_port->port.dev)
387 return;
389 clk_disable(sci_port->fclk);
390 clk_disable(sci_port->iclk);
392 pm_runtime_put_sync(sci_port->port.dev);
395 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
397 #ifdef CONFIG_CONSOLE_POLL
398 static int sci_poll_get_char(struct uart_port *port)
400 unsigned short status;
401 int c;
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;
409 break;
410 } while (1);
412 if (!(status & SCxSR_RDxF(port)))
413 return NO_POLL_CHAR;
415 c = sci_in(port, SCxRDR);
417 /* Dummy read */
418 sci_in(port, SCxSR);
419 sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
421 return c;
423 #endif
425 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
427 unsigned short status;
429 do {
430 status = sci_in(port, SCxSR);
431 } while (!(status & SCxSR_TDxE(port)));
433 sci_out(port, SCxTDR, c);
434 sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
436 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
438 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
440 struct sci_port *s = to_sci_port(port);
441 struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
444 * Use port-specific handler if provided.
446 if (s->cfg->ops && s->cfg->ops->init_pins) {
447 s->cfg->ops->init_pins(port, cflag);
448 return;
452 * For the generic path SCSPTR is necessary. Bail out if that's
453 * unavailable, too.
455 if (!reg->size)
456 return;
458 if (!(cflag & CRTSCTS))
459 sci_out(port, SCSPTR, 0x0080); /* Set RTS = 1 */
462 static int sci_txfill(struct uart_port *port)
464 struct plat_sci_reg *reg;
466 reg = sci_getreg(port, SCTFDR);
467 if (reg->size)
468 return sci_in(port, SCTFDR) & 0xff;
470 reg = sci_getreg(port, SCFDR);
471 if (reg->size)
472 return sci_in(port, SCFDR) >> 8;
474 return !(sci_in(port, SCxSR) & SCI_TDRE);
477 static int sci_txroom(struct uart_port *port)
479 return port->fifosize - sci_txfill(port);
482 static int sci_rxfill(struct uart_port *port)
484 struct plat_sci_reg *reg;
486 reg = sci_getreg(port, SCRFDR);
487 if (reg->size)
488 return sci_in(port, SCRFDR) & 0xff;
490 reg = sci_getreg(port, SCFDR);
491 if (reg->size)
492 return sci_in(port, SCFDR) & ((port->fifosize << 1) - 1);
494 return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
498 * SCI helper for checking the state of the muxed port/RXD pins.
500 static inline int sci_rxd_in(struct uart_port *port)
502 struct sci_port *s = to_sci_port(port);
504 if (s->cfg->port_reg <= 0)
505 return 1;
507 return !!__raw_readb(s->cfg->port_reg);
510 /* ********************************************************************** *
511 * the interrupt related routines *
512 * ********************************************************************** */
514 static void sci_transmit_chars(struct uart_port *port)
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;
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;
533 count = sci_txroom(port);
535 do {
536 unsigned char c;
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;
548 sci_out(port, SCxTDR, c);
550 port->icount.tx++;
551 } while (--count > 0);
553 sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
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);
562 if (port->type != PORT_SCI) {
563 sci_in(port, SCxSR); /* Dummy read */
564 sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
567 ctrl |= SCSCR_TIE;
568 sci_out(port, SCSCR, ctrl);
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); })
575 static void sci_receive_chars(struct uart_port *port)
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;
583 status = sci_in(port, SCxSR);
584 if (!(status & SCxSR_RDxF(port)))
585 return;
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));
591 /* If for any reason we can't copy more data, we're done! */
592 if (count == 0)
593 break;
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;
615 /* Nonzero => end-of-break */
616 dev_dbg(port->dev, "debounce<%02x>\n", c);
617 sci_port->break_flag = 0;
619 if (STEPFN(c)) {
620 count--; i--;
621 continue;
624 #endif /* CONFIG_CPU_SH3 */
625 if (uart_handle_sysrq_char(port, c)) {
626 count--; i--;
627 continue;
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;
640 tty_insert_flip_char(tty, c, flag);
644 sci_in(port, SCxSR); /* dummy read */
645 sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
647 copied += count;
648 port->icount.rx += count;
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));
660 #define SCI_BREAK_JIFFIES (HZ/20)
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.
670 static inline void sci_schedule_break_timer(struct sci_port *port)
672 mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
675 /* Ensure that two consecutive samples find the break over. */
676 static void sci_break_timer(unsigned long data)
678 struct sci_port *port = (struct sci_port *)data;
680 sci_port_enable(port);
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;
692 sci_port_disable(port);
695 static int sci_handle_errors(struct uart_port *port)
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);
703 * Handle overruns, if supported.
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++;
711 dev_notice(port->dev, "overrun error");
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);
720 if (!sci_port->break_flag) {
721 sci_port->break_flag = 1;
722 sci_schedule_break_timer(sci_port);
724 /* Do sysrq handling. */
725 if (uart_handle_break(port))
726 return 0;
728 dev_dbg(port->dev, "BREAK detected\n");
730 if (tty_insert_flip_char(tty, 0, TTY_BREAK))
731 copied++;
734 } else {
735 /* frame error */
736 if (tty_insert_flip_char(tty, 0, TTY_FRAME))
737 copied++;
739 dev_notice(port->dev, "frame error\n");
743 if (status & SCxSR_PER(port)) {
744 /* parity error */
745 if (tty_insert_flip_char(tty, 0, TTY_PARITY))
746 copied++;
748 dev_notice(port->dev, "parity error");
751 if (copied)
752 tty_flip_buffer_push(tty);
754 return copied;
757 static int sci_handle_fifo_overrun(struct uart_port *port)
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;
764 reg = sci_getreg(port, SCLSR);
765 if (!reg->size)
766 return 0;
768 if ((sci_in(port, SCLSR) & (1 << s->cfg->overrun_bit))) {
769 sci_out(port, SCLSR, 0);
771 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
772 tty_flip_buffer_push(tty);
774 dev_notice(port->dev, "overrun error\n");
775 copied++;
778 return copied;
781 static int sci_handle_breaks(struct uart_port *port)
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);
788 if (uart_handle_break(port))
789 return 0;
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++;
800 dev_dbg(port->dev, "BREAK detected\n");
803 if (copied)
804 tty_flip_buffer_push(tty);
806 copied += sci_handle_fifo_overrun(port);
808 return copied;
811 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
813 #ifdef CONFIG_SERIAL_SH_SCI_DMA
814 struct uart_port *port = ptr;
815 struct sci_port *s = to_sci_port(port);
817 if (s->chan_rx) {
818 u16 scr = sci_in(port, SCSCR);
819 u16 ssr = sci_in(port, SCxSR);
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;
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);
835 return IRQ_HANDLED;
837 #endif
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?
843 sci_receive_chars(ptr);
845 return IRQ_HANDLED;
848 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
850 struct uart_port *port = ptr;
851 unsigned long flags;
853 spin_lock_irqsave(&port->lock, flags);
854 sci_transmit_chars(port);
855 spin_unlock_irqrestore(&port->lock, flags);
857 return IRQ_HANDLED;
860 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
862 struct uart_port *port = ptr;
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));
871 } else {
872 sci_handle_fifo_overrun(port);
873 sci_rx_interrupt(irq, ptr);
876 sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
878 /* Kick the transmission */
879 sci_tx_interrupt(irq, ptr);
881 return IRQ_HANDLED;
884 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
886 struct uart_port *port = ptr;
888 /* Handle BREAKs */
889 sci_handle_breaks(port);
890 sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
892 return IRQ_HANDLED;
895 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
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.
904 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
907 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
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;
914 ssr_status = sci_in(port, SCxSR);
915 scr_status = sci_in(port, SCSCR);
916 err_enabled = scr_status & port_rx_irq_mask(port);
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);
924 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
925 * DR flags
927 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
928 (scr_status & SCSCR_RIE))
929 ret = sci_rx_interrupt(irq, ptr);
931 /* Error Interrupt */
932 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
933 ret = sci_er_interrupt(irq, ptr);
935 /* Break Interrupt */
936 if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
937 ret = sci_br_interrupt(irq, ptr);
939 return ret;
943 * Here we define a transition notifier so that we can update all of our
944 * ports' baud rate when the peripheral clock changes.
946 static int sci_notifier(struct notifier_block *self,
947 unsigned long phase, void *p)
949 struct sci_port *sci_port;
950 unsigned long flags;
952 sci_port = container_of(self, struct sci_port, freq_transition);
954 if ((phase == CPUFREQ_POSTCHANGE) ||
955 (phase == CPUFREQ_RESUMECHANGE)) {
956 struct uart_port *port = &sci_port->port;
958 spin_lock_irqsave(&port->lock, flags);
959 port->uartclk = clk_get_rate(sci_port->iclk);
960 spin_unlock_irqrestore(&port->lock, flags);
963 return NOTIFY_OK;
966 static struct sci_irq_desc {
967 const char *desc;
968 irq_handler_t handler;
969 } sci_irq_desc[] = {
971 * Split out handlers, the default case.
973 [SCIx_ERI_IRQ] = {
974 .desc = "rx err",
975 .handler = sci_er_interrupt,
978 [SCIx_RXI_IRQ] = {
979 .desc = "rx full",
980 .handler = sci_rx_interrupt,
983 [SCIx_TXI_IRQ] = {
984 .desc = "tx empty",
985 .handler = sci_tx_interrupt,
988 [SCIx_BRI_IRQ] = {
989 .desc = "break",
990 .handler = sci_br_interrupt,
994 * Special muxed handler.
996 [SCIx_MUX_IRQ] = {
997 .desc = "mux",
998 .handler = sci_mpxed_interrupt,
1002 static int sci_request_irq(struct sci_port *port)
1004 struct uart_port *up = &port->port;
1005 int i, j, ret = 0;
1007 for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1008 struct sci_irq_desc *desc;
1009 unsigned int irq;
1011 if (SCIx_IRQ_IS_MUXED(port)) {
1012 i = SCIx_MUX_IRQ;
1013 irq = up->irq;
1014 } else
1015 irq = port->cfg->irqs[i];
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;
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;
1034 return 0;
1036 out_noirq:
1037 while (--i >= 0)
1038 free_irq(port->cfg->irqs[i], port);
1040 out_nomem:
1041 while (--j >= 0)
1042 kfree(port->irqstr[j]);
1044 return ret;
1047 static void sci_free_irq(struct sci_port *port)
1049 int i;
1052 * Intentionally in reverse order so we iterate over the muxed
1053 * IRQ first.
1055 for (i = 0; i < SCIx_NR_IRQS; i++) {
1056 free_irq(port->cfg->irqs[i], port);
1057 kfree(port->irqstr[i]);
1059 if (SCIx_IRQ_IS_MUXED(port)) {
1060 /* If there's only one IRQ, we're done. */
1061 return;
1066 static unsigned int sci_tx_empty(struct uart_port *port)
1068 unsigned short status = sci_in(port, SCxSR);
1069 unsigned short in_tx_fifo = sci_txfill(port);
1071 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1074 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
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. */
1081 static unsigned int sci_get_mctrl(struct uart_port *port)
1083 /* This routine is used for getting signals of: DTR, DCD, DSR, RI,
1084 and CTS/RTS */
1086 return TIOCM_DTR | TIOCM_RTS | TIOCM_CTS | TIOCM_DSR;
1089 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1090 static void sci_dma_tx_complete(void *arg)
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;
1097 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1099 spin_lock_irqsave(&port->lock, flags);
1101 xmit->tail += sg_dma_len(&s->sg_tx);
1102 xmit->tail &= UART_XMIT_SIZE - 1;
1104 port->icount.tx += sg_dma_len(&s->sg_tx);
1106 async_tx_ack(s->desc_tx);
1107 s->cookie_tx = -EINVAL;
1108 s->desc_tx = NULL;
1110 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1111 uart_write_wakeup(port);
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);
1120 spin_unlock_irqrestore(&port->lock, flags);
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)
1127 struct uart_port *port = &s->port;
1128 int i, active, room;
1130 room = tty_buffer_request_room(tty, count);
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;
1141 if (room < count)
1142 dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
1143 count - room);
1144 if (!room)
1145 return room;
1147 for (i = 0; i < room; i++)
1148 tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
1149 TTY_NORMAL);
1151 port->icount.rx += room;
1153 return room;
1156 static void sci_dma_rx_complete(void *arg)
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;
1164 dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
1166 spin_lock_irqsave(&port->lock, flags);
1168 count = sci_dma_rx_push(s, tty, s->buf_len_rx);
1170 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1172 spin_unlock_irqrestore(&port->lock, flags);
1174 if (count)
1175 tty_flip_buffer_push(tty);
1177 schedule_work(&s->work_rx);
1180 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1182 struct dma_chan *chan = s->chan_rx;
1183 struct uart_port *port = &s->port;
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);
1195 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1197 struct dma_chan *chan = s->chan_tx;
1198 struct uart_port *port = &s->port;
1200 s->chan_tx = NULL;
1201 s->cookie_tx = -EINVAL;
1202 dma_release_channel(chan);
1203 if (enable_pio)
1204 sci_start_tx(port);
1207 static void sci_submit_rx(struct sci_port *s)
1209 struct dma_chan *chan = s->chan_rx;
1210 int i;
1212 for (i = 0; i < 2; i++) {
1213 struct scatterlist *sg = &s->sg_rx[i];
1214 struct dma_async_tx_descriptor *desc;
1216 desc = chan->device->device_prep_slave_sg(chan,
1217 sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);
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);
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;
1231 if (desc) {
1232 async_tx_ack(desc);
1233 s->cookie_rx[i] = -EINVAL;
1235 dev_warn(s->port.dev,
1236 "failed to re-start DMA, using PIO\n");
1237 sci_rx_dma_release(s, true);
1238 return;
1240 dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1241 s->cookie_rx[i], i);
1244 s->active_rx = s->cookie_rx[0];
1246 dma_async_issue_pending(chan);
1249 static void work_fn_rx(struct work_struct *work)
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;
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;
1264 desc = s->desc_rx[new];
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;
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);
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);
1284 if (count)
1285 tty_flip_buffer_push(tty);
1287 sci_submit_rx(s);
1289 return;
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;
1299 s->active_rx = s->cookie_rx[!new];
1301 dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
1302 s->cookie_rx[new], new, s->active_rx);
1305 static void work_fn_tx(struct work_struct *work)
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;
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.
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);
1329 BUG_ON(!sg_dma_len(sg));
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;
1340 dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
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;
1355 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,
1356 xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1358 dma_async_issue_pending(chan);
1360 #endif
1362 static void sci_start_tx(struct uart_port *port)
1364 struct sci_port *s = to_sci_port(port);
1365 unsigned short ctrl;
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);
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
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);
1390 static void sci_stop_tx(struct uart_port *port)
1392 unsigned short ctrl;
1394 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
1395 ctrl = sci_in(port, SCSCR);
1397 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1398 ctrl &= ~0x8000;
1400 ctrl &= ~SCSCR_TIE;
1402 sci_out(port, SCSCR, ctrl);
1405 static void sci_start_rx(struct uart_port *port)
1407 unsigned short ctrl;
1409 ctrl = sci_in(port, SCSCR) | port_rx_irq_mask(port);
1411 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1412 ctrl &= ~0x4000;
1414 sci_out(port, SCSCR, ctrl);
1417 static void sci_stop_rx(struct uart_port *port)
1419 unsigned short ctrl;
1421 ctrl = sci_in(port, SCSCR);
1423 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1424 ctrl &= ~0x4000;
1426 ctrl &= ~port_rx_irq_mask(port);
1428 sci_out(port, SCSCR, ctrl);
1431 static void sci_enable_ms(struct uart_port *port)
1433 /* Nothing here yet .. */
1436 static void sci_break_ctl(struct uart_port *port, int break_state)
1438 /* Nothing here yet .. */
1441 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1442 static bool filter(struct dma_chan *chan, void *slave)
1444 struct sh_dmae_slave *param = slave;
1446 dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
1447 param->slave_id);
1449 if (param->dma_dev == chan->device->dev) {
1450 chan->private = param;
1451 return true;
1452 } else {
1453 return false;
1457 static void rx_timer_fn(unsigned long arg)
1459 struct sci_port *s = (struct sci_port *)arg;
1460 struct uart_port *port = &s->port;
1461 u16 scr = sci_in(port, SCSCR);
1463 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1464 scr &= ~0x4000;
1465 enable_irq(s->cfg->irqs[1]);
1467 sci_out(port, SCSCR, scr | SCSCR_RIE);
1468 dev_dbg(port->dev, "DMA Rx timed out\n");
1469 schedule_work(&s->work_rx);
1472 static void sci_request_dma(struct uart_port *port)
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;
1480 dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
1481 port->line, s->cfg->dma_dev);
1483 if (!s->cfg->dma_dev)
1484 return;
1486 dma_cap_zero(mask);
1487 dma_cap_set(DMA_SLAVE, mask);
1489 param = &s->param_tx;
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;
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));
1513 s->sg_len_tx = nent;
1515 INIT_WORK(&s->work_tx, work_fn_tx);
1518 param = &s->param_rx;
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;
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;
1531 s->chan_rx = chan;
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);
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;
1544 buf[1] = buf[0] + s->buf_len_rx;
1545 dma[1] = dma[0] + s->buf_len_rx;
1547 for (i = 0; i < 2; i++) {
1548 struct scatterlist *sg = &s->sg_rx[i];
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];
1556 INIT_WORK(&s->work_rx, work_fn_rx);
1557 setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1559 sci_submit_rx(s);
1563 static void sci_free_dma(struct uart_port *port)
1565 struct sci_port *s = to_sci_port(port);
1567 if (!s->cfg->dma_dev)
1568 return;
1570 if (s->chan_tx)
1571 sci_tx_dma_release(s, false);
1572 if (s->chan_rx)
1573 sci_rx_dma_release(s, false);
1575 #else
1576 static inline void sci_request_dma(struct uart_port *port)
1580 static inline void sci_free_dma(struct uart_port *port)
1583 #endif
1585 static int sci_startup(struct uart_port *port)
1587 struct sci_port *s = to_sci_port(port);
1588 int ret;
1590 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1592 sci_port_enable(s);
1594 ret = sci_request_irq(s);
1595 if (unlikely(ret < 0))
1596 return ret;
1598 sci_request_dma(port);
1600 sci_start_tx(port);
1601 sci_start_rx(port);
1603 return 0;
1606 static void sci_shutdown(struct uart_port *port)
1608 struct sci_port *s = to_sci_port(port);
1610 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1612 sci_stop_rx(port);
1613 sci_stop_tx(port);
1615 sci_free_dma(port);
1616 sci_free_irq(s);
1618 sci_port_disable(s);
1621 static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps,
1622 unsigned long freq)
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);
1637 /* Warn, but use a safe default */
1638 WARN_ON(1);
1640 return ((freq + 16 * bps) / (32 * bps) - 1);
1643 static void sci_reset(struct uart_port *port)
1645 unsigned int status;
1647 do {
1648 status = sci_in(port, SCxSR);
1649 } while (!(status & SCxSR_TEND(port)));
1651 sci_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */
1653 if (port->type != PORT_SCI)
1654 sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
1657 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
1658 struct ktermios *old)
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;
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.
1673 max_baud = port->uartclk ? port->uartclk / 16 : 115200;
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);
1679 sci_port_enable(s);
1681 sci_reset(port);
1683 smr_val = sci_in(port, SCSMR) & 3;
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;
1694 uart_update_timeout(port, termios->c_cflag, baud);
1696 sci_out(port, SCSMR, smr_val);
1698 dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,
1699 s->cfg->scscr);
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);
1708 sci_out(port, SCBRR, t);
1709 udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
1712 sci_init_pins(port, termios->c_cflag);
1713 sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
1715 sci_out(port, SCSCR, s->cfg->scscr);
1717 #ifdef CONFIG_SERIAL_SH_SCI_DMA
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.
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);
1737 #endif
1739 if ((termios->c_cflag & CREAD) != 0)
1740 sci_start_rx(port);
1742 sci_port_disable(s);
1745 static const char *sci_type(struct uart_port *port)
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";
1760 return NULL;
1763 static inline unsigned long sci_port_size(struct uart_port *port)
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.
1771 return 64;
1774 static int sci_remap_port(struct uart_port *port)
1776 unsigned long size = sci_port_size(port);
1779 * Nothing to do if there's already an established membase.
1781 if (port->membase)
1782 return 0;
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;
1790 } else {
1792 * For the simple (and majority of) cases where we don't
1793 * need to do any remapping, just cast the cookie
1794 * directly.
1796 port->membase = (void __iomem *)port->mapbase;
1799 return 0;
1802 static void sci_release_port(struct uart_port *port)
1804 if (port->flags & UPF_IOREMAP) {
1805 iounmap(port->membase);
1806 port->membase = NULL;
1809 release_mem_region(port->mapbase, sci_port_size(port));
1812 static int sci_request_port(struct uart_port *port)
1814 unsigned long size = sci_port_size(port);
1815 struct resource *res;
1816 int ret;
1818 res = request_mem_region(port->mapbase, size, dev_name(port->dev));
1819 if (unlikely(res == NULL))
1820 return -EBUSY;
1822 ret = sci_remap_port(port);
1823 if (unlikely(ret != 0)) {
1824 release_resource(res);
1825 return ret;
1828 return 0;
1831 static void sci_config_port(struct uart_port *port, int flags)
1833 if (flags & UART_CONFIG_TYPE) {
1834 struct sci_port *sport = to_sci_port(port);
1836 port->type = sport->cfg->type;
1837 sci_request_port(port);
1841 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
1843 struct sci_port *s = to_sci_port(port);
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;
1851 return 0;
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
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)
1882 struct uart_port *port = &sci_port->port;
1883 int ret;
1885 port->ops = &sci_uart_ops;
1886 port->iotype = UPIO_MEM;
1887 port->line = index;
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;
1904 if (p->regtype == SCIx_PROBE_REGTYPE) {
1905 ret = sci_probe_regmap(p);
1906 if (unlikely(ret))
1907 return ret;
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);
1921 * The function clock is optional, ignore it if we can't
1922 * find it.
1924 sci_port->fclk = clk_get(&dev->dev, "sci_fck");
1925 if (IS_ERR(sci_port->fclk))
1926 sci_port->fclk = NULL;
1928 port->dev = &dev->dev;
1930 pm_runtime_irq_safe(&dev->dev);
1931 pm_runtime_enable(&dev->dev);
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);
1939 * Establish some sensible defaults for the error detection.
1941 if (!p->error_mask)
1942 p->error_mask = (p->type == PORT_SCI) ?
1943 SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK;
1946 * Establish sensible defaults for the overrun detection, unless
1947 * the part has explicitly disabled support for it.
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;
1958 * Make the error mask inclusive of overrun detection, if
1959 * supported.
1961 p->error_mask |= (1 << p->overrun_bit);
1964 sci_port->cfg = p;
1966 port->mapbase = p->mapbase;
1967 port->type = p->type;
1968 port->flags = p->flags;
1969 port->regshift = p->regshift;
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.
1976 * For the muxed case there's nothing more to do.
1978 port->irq = p->irqs[SCIx_RXI_IRQ];
1979 port->irqflags = IRQF_DISABLED;
1981 port->serial_in = sci_serial_in;
1982 port->serial_out = sci_serial_out;
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);
1988 return 0;
1991 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
1992 static void serial_console_putchar(struct uart_port *port, int ch)
1994 sci_poll_put_char(port, ch);
1998 * Print a string to the serial port trying not to disturb
1999 * any possible real use of the port...
2001 static void serial_console_write(struct console *co, const char *s,
2002 unsigned count)
2004 struct sci_port *sci_port = &sci_ports[co->index];
2005 struct uart_port *port = &sci_port->port;
2006 unsigned short bits;
2008 sci_port_enable(sci_port);
2010 uart_console_write(port, s, count, serial_console_putchar);
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();
2017 sci_port_disable(sci_port);
2020 static int __devinit serial_console_setup(struct console *co, char *options)
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;
2031 * Refuse to handle any bogus ports.
2033 if (co->index < 0 || co->index >= SCI_NPORTS)
2034 return -ENODEV;
2036 sci_port = &sci_ports[co->index];
2037 port = &sci_port->port;
2040 * Refuse to handle uninitialized ports.
2042 if (!port->ops)
2043 return -ENODEV;
2045 ret = sci_remap_port(port);
2046 if (unlikely(ret != 0))
2047 return ret;
2049 sci_port_enable(sci_port);
2051 if (options)
2052 uart_parse_options(options, &baud, &parity, &bits, &flow);
2054 sci_port_disable(sci_port);
2056 return uart_set_options(port, co, baud, parity, bits, flow);
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,
2069 static struct console early_serial_console = {
2070 .name = "early_ttySC",
2071 .write = serial_console_write,
2072 .flags = CON_PRINTBUFFER,
2073 .index = -1,
2076 static char early_serial_buf[32];
2078 static int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
2080 struct plat_sci_port *cfg = pdev->dev.platform_data;
2082 if (early_serial_console.data)
2083 return -EEXIST;
2085 early_serial_console.index = pdev->id;
2087 sci_init_single(NULL, &sci_ports[pdev->id], pdev->id, cfg);
2089 serial_console_setup(&early_serial_console, early_serial_buf);
2091 if (!strstr(early_serial_buf, "keep"))
2092 early_serial_console.flags |= CON_BOOT;
2094 register_console(&early_serial_console);
2095 return 0;
2098 #define uart_console(port) ((port)->cons->index == (port)->line)
2100 static int sci_runtime_suspend(struct device *dev)
2102 struct sci_port *sci_port = dev_get_drvdata(dev);
2103 struct uart_port *port = &sci_port->port;
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);
2110 return 0;
2113 static int sci_runtime_resume(struct device *dev)
2115 struct sci_port *sci_port = dev_get_drvdata(dev);
2116 struct uart_port *port = &sci_port->port;
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);
2125 return 0;
2128 #define SCI_CONSOLE (&serial_console)
2130 #else
2131 static inline int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
2133 return -EINVAL;
2136 #define SCI_CONSOLE NULL
2137 #define sci_runtime_suspend NULL
2138 #define sci_runtime_resume NULL
2140 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
2142 static char banner[] __initdata =
2143 KERN_INFO "SuperH SCI(F) driver initialized\n";
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,
2155 static int sci_remove(struct platform_device *dev)
2157 struct sci_port *port = platform_get_drvdata(dev);
2159 cpufreq_unregister_notifier(&port->freq_transition,
2160 CPUFREQ_TRANSITION_NOTIFIER);
2162 uart_remove_one_port(&sci_uart_driver, &port->port);
2164 clk_put(port->iclk);
2165 clk_put(port->fclk);
2167 pm_runtime_disable(&dev->dev);
2168 return 0;
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)
2176 int ret;
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;
2188 ret = sci_init_single(dev, sciport, index, p);
2189 if (ret)
2190 return ret;
2192 return uart_add_one_port(&sci_uart_driver, &sciport->port);
2195 static int __devinit sci_probe(struct platform_device *dev)
2197 struct plat_sci_port *p = dev->dev.platform_data;
2198 struct sci_port *sp = &sci_ports[dev->id];
2199 int ret;
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.
2206 if (is_early_platform_device(dev))
2207 return sci_probe_earlyprintk(dev);
2209 platform_set_drvdata(dev, sp);
2211 ret = sci_probe_single(dev, dev->id, p, sp);
2212 if (ret)
2213 goto err_unreg;
2215 sp->freq_transition.notifier_call = sci_notifier;
2217 ret = cpufreq_register_notifier(&sp->freq_transition,
2218 CPUFREQ_TRANSITION_NOTIFIER);
2219 if (unlikely(ret < 0))
2220 goto err_unreg;
2222 #ifdef CONFIG_SH_STANDARD_BIOS
2223 sh_bios_gdb_detach();
2224 #endif
2226 return 0;
2228 err_unreg:
2229 sci_remove(dev);
2230 return ret;
2233 static int sci_suspend(struct device *dev)
2235 struct sci_port *sport = dev_get_drvdata(dev);
2237 if (sport)
2238 uart_suspend_port(&sci_uart_driver, &sport->port);
2240 return 0;
2243 static int sci_resume(struct device *dev)
2245 struct sci_port *sport = dev_get_drvdata(dev);
2247 if (sport)
2248 uart_resume_port(&sci_uart_driver, &sport->port);
2250 return 0;
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,
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,
2270 static int __init sci_init(void)
2272 int ret;
2274 printk(banner);
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);
2283 return ret;
2286 static void __exit sci_exit(void)
2288 platform_driver_unregister(&sci_driver);
2289 uart_unregister_driver(&sci_uart_driver);
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);
2299 MODULE_LICENSE("GPL");
2300 MODULE_ALIAS("platform:sh-sci");
2301 MODULE_AUTHOR("Paul Mundt");
2302 MODULE_DESCRIPTION("SuperH SCI(F) serial driver");