?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
serial: sh-sci: Fix up break timer scheduling race.
[linux-2.6/libata-dev.git] / drivers / serial / sh-sci.c
blob999fe5f5d938800329c5ce7aba257f03b0f5811a
1 /*
2 * drivers/serial/sh-sci.c
3 *
4 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
5 *
6 * Copyright (C) 2002 - 2011 Paul Mundt
7 * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8 *
9 * based off of the old drivers/char/sh-sci.c by:
10 *
11 * Copyright (C) 1999, 2000 Niibe Yutaka
12 * Copyright (C) 2000 Sugioka Toshinobu
13 * Modified to support multiple serial ports. Stuart Menefy (May 2000).
14 * Modified to support SecureEdge. David McCullough (2002)
15 * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16 * Removed SH7300 support (Jul 2007).
17 *
18 * This file is subject to the terms and conditions of the GNU General Public
19 * License. See the file "COPYING" in the main directory of this archive
20 * for more details.
21 */
22 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
23 #define SUPPORT_SYSRQ
24 #endif
25
26 #undef DEBUG
27
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/timer.h>
31 #include <linux/interrupt.h>
32 #include <linux/tty.h>
33 #include <linux/tty_flip.h>
34 #include <linux/serial.h>
35 #include <linux/major.h>
36 #include <linux/string.h>
37 #include <linux/sysrq.h>
38 #include <linux/ioport.h>
39 #include <linux/mm.h>
40 #include <linux/init.h>
41 #include <linux/delay.h>
42 #include <linux/console.h>
43 #include <linux/platform_device.h>
44 #include <linux/serial_sci.h>
45 #include <linux/notifier.h>
46 #include <linux/cpufreq.h>
47 #include <linux/clk.h>
48 #include <linux/ctype.h>
49 #include <linux/err.h>
50 #include <linux/dmaengine.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 #ifdef CONFIG_H8300
59 #include <asm/gpio.h>
60 #endif
61
62 #include "sh-sci.h"
63
64 struct sci_port {
65 struct uart_port port;
66
67 /* Platform configuration */
68 struct plat_sci_port *cfg;
69
70 /* Port enable callback */
71 void (*enable)(struct uart_port *port);
72
73 /* Port disable callback */
74 void (*disable)(struct uart_port *port);
75
76 /* Break timer */
77 struct timer_list break_timer;
78 int break_flag;
79
80 /* Interface clock */
81 struct clk *iclk;
82 /* Function clock */
83 struct clk *fclk;
84
85 struct dma_chan *chan_tx;
86 struct dma_chan *chan_rx;
87
88 #ifdef CONFIG_SERIAL_SH_SCI_DMA
89 struct dma_async_tx_descriptor *desc_tx;
90 struct dma_async_tx_descriptor *desc_rx[2];
91 dma_cookie_t cookie_tx;
92 dma_cookie_t cookie_rx[2];
93 dma_cookie_t active_rx;
94 struct scatterlist sg_tx;
95 unsigned int sg_len_tx;
96 struct scatterlist sg_rx[2];
97 size_t buf_len_rx;
98 struct sh_dmae_slave param_tx;
99 struct sh_dmae_slave param_rx;
100 struct work_struct work_tx;
101 struct work_struct work_rx;
102 struct timer_list rx_timer;
103 unsigned int rx_timeout;
104 #endif
105
106 struct notifier_block freq_transition;
107 };
108
109 /* Function prototypes */
110 static void sci_start_tx(struct uart_port *port);
111 static void sci_stop_tx(struct uart_port *port);
112 static void sci_start_rx(struct uart_port *port);
113
114 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
115
116 static struct sci_port sci_ports[SCI_NPORTS];
117 static struct uart_driver sci_uart_driver;
118
119 static inline struct sci_port *
120 to_sci_port(struct uart_port *uart)
121 {
122 return container_of(uart, struct sci_port, port);
123 }
124
125 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
126
127 #ifdef CONFIG_CONSOLE_POLL
128 static int sci_poll_get_char(struct uart_port *port)
129 {
130 unsigned short status;
131 int c;
132
133 do {
134 status = sci_in(port, SCxSR);
135 if (status & SCxSR_ERRORS(port)) {
136 sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
137 continue;
138 }
139 break;
140 } while (1);
141
142 if (!(status & SCxSR_RDxF(port)))
143 return NO_POLL_CHAR;
144
145 c = sci_in(port, SCxRDR);
146
147 /* Dummy read */
148 sci_in(port, SCxSR);
149 sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
150
151 return c;
152 }
153 #endif
154
155 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
156 {
157 unsigned short status;
158
159 do {
160 status = sci_in(port, SCxSR);
161 } while (!(status & SCxSR_TDxE(port)));
162
163 sci_out(port, SCxTDR, c);
164 sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
165 }
166 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
167
168 #if defined(__H8300H__) || defined(__H8300S__)
169 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
170 {
171 int ch = (port->mapbase - SMR0) >> 3;
172
173 /* set DDR regs */
174 H8300_GPIO_DDR(h8300_sci_pins[ch].port,
175 h8300_sci_pins[ch].rx,
176 H8300_GPIO_INPUT);
177 H8300_GPIO_DDR(h8300_sci_pins[ch].port,
178 h8300_sci_pins[ch].tx,
179 H8300_GPIO_OUTPUT);
180
181 /* tx mark output*/
182 H8300_SCI_DR(ch) |= h8300_sci_pins[ch].tx;
183 }
184 #elif defined(CONFIG_CPU_SUBTYPE_SH7710) || defined(CONFIG_CPU_SUBTYPE_SH7712)
185 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
186 {
187 if (port->mapbase == 0xA4400000) {
188 __raw_writew(__raw_readw(PACR) & 0xffc0, PACR);
189 __raw_writew(__raw_readw(PBCR) & 0x0fff, PBCR);
190 } else if (port->mapbase == 0xA4410000)
191 __raw_writew(__raw_readw(PBCR) & 0xf003, PBCR);
192 }
193 #elif defined(CONFIG_CPU_SUBTYPE_SH7720) || defined(CONFIG_CPU_SUBTYPE_SH7721)
194 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
195 {
196 unsigned short data;
197
198 if (cflag & CRTSCTS) {
199 /* enable RTS/CTS */
200 if (port->mapbase == 0xa4430000) { /* SCIF0 */
201 /* Clear PTCR bit 9-2; enable all scif pins but sck */
202 data = __raw_readw(PORT_PTCR);
203 __raw_writew((data & 0xfc03), PORT_PTCR);
204 } else if (port->mapbase == 0xa4438000) { /* SCIF1 */
205 /* Clear PVCR bit 9-2 */
206 data = __raw_readw(PORT_PVCR);
207 __raw_writew((data & 0xfc03), PORT_PVCR);
208 }
209 } else {
210 if (port->mapbase == 0xa4430000) { /* SCIF0 */
211 /* Clear PTCR bit 5-2; enable only tx and rx */
212 data = __raw_readw(PORT_PTCR);
213 __raw_writew((data & 0xffc3), PORT_PTCR);
214 } else if (port->mapbase == 0xa4438000) { /* SCIF1 */
215 /* Clear PVCR bit 5-2 */
216 data = __raw_readw(PORT_PVCR);
217 __raw_writew((data & 0xffc3), PORT_PVCR);
218 }
219 }
220 }
221 #elif defined(CONFIG_CPU_SH3)
222 /* For SH7705, SH7706, SH7707, SH7709, SH7709A, SH7729 */
223 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
224 {
225 unsigned short data;
226
227 /* We need to set SCPCR to enable RTS/CTS */
228 data = __raw_readw(SCPCR);
229 /* Clear out SCP7MD1,0, SCP6MD1,0, SCP4MD1,0*/
230 __raw_writew(data & 0x0fcf, SCPCR);
231
232 if (!(cflag & CRTSCTS)) {
233 /* We need to set SCPCR to enable RTS/CTS */
234 data = __raw_readw(SCPCR);
235 /* Clear out SCP7MD1,0, SCP4MD1,0,
236 Set SCP6MD1,0 = {01} (output) */
237 __raw_writew((data & 0x0fcf) | 0x1000, SCPCR);
238
239 data = __raw_readb(SCPDR);
240 /* Set /RTS2 (bit6) = 0 */
241 __raw_writeb(data & 0xbf, SCPDR);
242 }
243 }
244 #elif defined(CONFIG_CPU_SUBTYPE_SH7722)
245 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
246 {
247 unsigned short data;
248
249 if (port->mapbase == 0xffe00000) {
250 data = __raw_readw(PSCR);
251 data &= ~0x03cf;
252 if (!(cflag & CRTSCTS))
253 data |= 0x0340;
254
255 __raw_writew(data, PSCR);
256 }
257 }
258 #elif defined(CONFIG_CPU_SUBTYPE_SH7757) || \
259 defined(CONFIG_CPU_SUBTYPE_SH7763) || \
260 defined(CONFIG_CPU_SUBTYPE_SH7780) || \
261 defined(CONFIG_CPU_SUBTYPE_SH7785) || \
262 defined(CONFIG_CPU_SUBTYPE_SH7786) || \
263 defined(CONFIG_CPU_SUBTYPE_SHX3)
264 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
265 {
266 if (!(cflag & CRTSCTS))
267 __raw_writew(0x0080, SCSPTR0); /* Set RTS = 1 */
268 }
269 #elif defined(CONFIG_CPU_SH4) && !defined(CONFIG_CPU_SH4A)
270 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
271 {
272 if (!(cflag & CRTSCTS))
273 __raw_writew(0x0080, SCSPTR2); /* Set RTS = 1 */
274 }
275 #else
276 static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
277 {
278 /* Nothing to do */
279 }
280 #endif
281
282 #if defined(CONFIG_CPU_SUBTYPE_SH7760) || \
283 defined(CONFIG_CPU_SUBTYPE_SH7780) || \
284 defined(CONFIG_CPU_SUBTYPE_SH7785) || \
285 defined(CONFIG_CPU_SUBTYPE_SH7786)
286 static int scif_txfill(struct uart_port *port)
287 {
288 return sci_in(port, SCTFDR) & 0xff;
289 }
290
291 static int scif_txroom(struct uart_port *port)
292 {
293 return SCIF_TXROOM_MAX - scif_txfill(port);
294 }
295
296 static int scif_rxfill(struct uart_port *port)
297 {
298 return sci_in(port, SCRFDR) & 0xff;
299 }
300 #elif defined(CONFIG_CPU_SUBTYPE_SH7763)
301 static int scif_txfill(struct uart_port *port)
302 {
303 if (port->mapbase == 0xffe00000 ||
304 port->mapbase == 0xffe08000)
305 /* SCIF0/1*/
306 return sci_in(port, SCTFDR) & 0xff;
307 else
308 /* SCIF2 */
309 return sci_in(port, SCFDR) >> 8;
310 }
311
312 static int scif_txroom(struct uart_port *port)
313 {
314 if (port->mapbase == 0xffe00000 ||
315 port->mapbase == 0xffe08000)
316 /* SCIF0/1*/
317 return SCIF_TXROOM_MAX - scif_txfill(port);
318 else
319 /* SCIF2 */
320 return SCIF2_TXROOM_MAX - scif_txfill(port);
321 }
322
323 static int scif_rxfill(struct uart_port *port)
324 {
325 if ((port->mapbase == 0xffe00000) ||
326 (port->mapbase == 0xffe08000)) {
327 /* SCIF0/1*/
328 return sci_in(port, SCRFDR) & 0xff;
329 } else {
330 /* SCIF2 */
331 return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
332 }
333 }
334 #elif defined(CONFIG_ARCH_SH7372)
335 static int scif_txfill(struct uart_port *port)
336 {
337 if (port->type == PORT_SCIFA)
338 return sci_in(port, SCFDR) >> 8;
339 else
340 return sci_in(port, SCTFDR);
341 }
342
343 static int scif_txroom(struct uart_port *port)
344 {
345 return port->fifosize - scif_txfill(port);
346 }
347
348 static int scif_rxfill(struct uart_port *port)
349 {
350 if (port->type == PORT_SCIFA)
351 return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
352 else
353 return sci_in(port, SCRFDR);
354 }
355 #else
356 static int scif_txfill(struct uart_port *port)
357 {
358 return sci_in(port, SCFDR) >> 8;
359 }
360
361 static int scif_txroom(struct uart_port *port)
362 {
363 return SCIF_TXROOM_MAX - scif_txfill(port);
364 }
365
366 static int scif_rxfill(struct uart_port *port)
367 {
368 return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
369 }
370 #endif
371
372 static int sci_txfill(struct uart_port *port)
373 {
374 return !(sci_in(port, SCxSR) & SCI_TDRE);
375 }
376
377 static int sci_txroom(struct uart_port *port)
378 {
379 return !sci_txfill(port);
380 }
381
382 static int sci_rxfill(struct uart_port *port)
383 {
384 return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
385 }
386
387 /* ********************************************************************** *
388 * the interrupt related routines *
389 * ********************************************************************** */
390
391 static void sci_transmit_chars(struct uart_port *port)
392 {
393 struct circ_buf *xmit = &port->state->xmit;
394 unsigned int stopped = uart_tx_stopped(port);
395 unsigned short status;
396 unsigned short ctrl;
397 int count;
398
399 status = sci_in(port, SCxSR);
400 if (!(status & SCxSR_TDxE(port))) {
401 ctrl = sci_in(port, SCSCR);
402 if (uart_circ_empty(xmit))
403 ctrl &= ~SCSCR_TIE;
404 else
405 ctrl |= SCSCR_TIE;
406 sci_out(port, SCSCR, ctrl);
407 return;
408 }
409
410 if (port->type == PORT_SCI)
411 count = sci_txroom(port);
412 else
413 count = scif_txroom(port);
414
415 do {
416 unsigned char c;
417
418 if (port->x_char) {
419 c = port->x_char;
420 port->x_char = 0;
421 } else if (!uart_circ_empty(xmit) && !stopped) {
422 c = xmit->buf[xmit->tail];
423 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
424 } else {
425 break;
426 }
427
428 sci_out(port, SCxTDR, c);
429
430 port->icount.tx++;
431 } while (--count > 0);
432
433 sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
434
435 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
436 uart_write_wakeup(port);
437 if (uart_circ_empty(xmit)) {
438 sci_stop_tx(port);
439 } else {
440 ctrl = sci_in(port, SCSCR);
441
442 if (port->type != PORT_SCI) {
443 sci_in(port, SCxSR); /* Dummy read */
444 sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
445 }
446
447 ctrl |= SCSCR_TIE;
448 sci_out(port, SCSCR, ctrl);
449 }
450 }
451
452 /* On SH3, SCIF may read end-of-break as a space->mark char */
453 #define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); })
454
455 static void sci_receive_chars(struct uart_port *port)
456 {
457 struct sci_port *sci_port = to_sci_port(port);
458 struct tty_struct *tty = port->state->port.tty;
459 int i, count, copied = 0;
460 unsigned short status;
461 unsigned char flag;
462
463 status = sci_in(port, SCxSR);
464 if (!(status & SCxSR_RDxF(port)))
465 return;
466
467 while (1) {
468 if (port->type == PORT_SCI)
469 count = sci_rxfill(port);
470 else
471 count = scif_rxfill(port);
472
473 /* Don't copy more bytes than there is room for in the buffer */
474 count = tty_buffer_request_room(tty, count);
475
476 /* If for any reason we can't copy more data, we're done! */
477 if (count == 0)
478 break;
479
480 if (port->type == PORT_SCI) {
481 char c = sci_in(port, SCxRDR);
482 if (uart_handle_sysrq_char(port, c) ||
483 sci_port->break_flag)
484 count = 0;
485 else
486 tty_insert_flip_char(tty, c, TTY_NORMAL);
487 } else {
488 for (i = 0; i < count; i++) {
489 char c = sci_in(port, SCxRDR);
490 status = sci_in(port, SCxSR);
491 #if defined(CONFIG_CPU_SH3)
492 /* Skip "chars" during break */
493 if (sci_port->break_flag) {
494 if ((c == 0) &&
495 (status & SCxSR_FER(port))) {
496 count--; i--;
497 continue;
498 }
499
500 /* Nonzero => end-of-break */
501 dev_dbg(port->dev, "debounce<%02x>\n", c);
502 sci_port->break_flag = 0;
503
504 if (STEPFN(c)) {
505 count--; i--;
506 continue;
507 }
508 }
509 #endif /* CONFIG_CPU_SH3 */
510 if (uart_handle_sysrq_char(port, c)) {
511 count--; i--;
512 continue;
513 }
514
515 /* Store data and status */
516 if (status & SCxSR_FER(port)) {
517 flag = TTY_FRAME;
518 dev_notice(port->dev, "frame error\n");
519 } else if (status & SCxSR_PER(port)) {
520 flag = TTY_PARITY;
521 dev_notice(port->dev, "parity error\n");
522 } else
523 flag = TTY_NORMAL;
524
525 tty_insert_flip_char(tty, c, flag);
526 }
527 }
528
529 sci_in(port, SCxSR); /* dummy read */
530 sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
531
532 copied += count;
533 port->icount.rx += count;
534 }
535
536 if (copied) {
537 /* Tell the rest of the system the news. New characters! */
538 tty_flip_buffer_push(tty);
539 } else {
540 sci_in(port, SCxSR); /* dummy read */
541 sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
542 }
543 }
544
545 #define SCI_BREAK_JIFFIES (HZ/20)
546
547 /*
548 * The sci generates interrupts during the break,
549 * 1 per millisecond or so during the break period, for 9600 baud.
550 * So dont bother disabling interrupts.
551 * But dont want more than 1 break event.
552 * Use a kernel timer to periodically poll the rx line until
553 * the break is finished.
554 */
555 static inline void sci_schedule_break_timer(struct sci_port *port)
556 {
557 mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
558 }
559
560 /* Ensure that two consecutive samples find the break over. */
561 static void sci_break_timer(unsigned long data)
562 {
563 struct sci_port *port = (struct sci_port *)data;
564
565 if (sci_rxd_in(&port->port) == 0) {
566 port->break_flag = 1;
567 sci_schedule_break_timer(port);
568 } else if (port->break_flag == 1) {
569 /* break is over. */
570 port->break_flag = 2;
571 sci_schedule_break_timer(port);
572 } else
573 port->break_flag = 0;
574 }
575
576 static int sci_handle_errors(struct uart_port *port)
577 {
578 int copied = 0;
579 unsigned short status = sci_in(port, SCxSR);
580 struct tty_struct *tty = port->state->port.tty;
581
582 if (status & SCxSR_ORER(port)) {
583 /* overrun error */
584 if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
585 copied++;
586
587 dev_notice(port->dev, "overrun error");
588 }
589
590 if (status & SCxSR_FER(port)) {
591 if (sci_rxd_in(port) == 0) {
592 /* Notify of BREAK */
593 struct sci_port *sci_port = to_sci_port(port);
594
595 if (!sci_port->break_flag) {
596 sci_port->break_flag = 1;
597 sci_schedule_break_timer(sci_port);
598
599 /* Do sysrq handling. */
600 if (uart_handle_break(port))
601 return 0;
602
603 dev_dbg(port->dev, "BREAK detected\n");
604
605 if (tty_insert_flip_char(tty, 0, TTY_BREAK))
606 copied++;
607 }
608
609 } else {
610 /* frame error */
611 if (tty_insert_flip_char(tty, 0, TTY_FRAME))
612 copied++;
613
614 dev_notice(port->dev, "frame error\n");
615 }
616 }
617
618 if (status & SCxSR_PER(port)) {
619 /* parity error */
620 if (tty_insert_flip_char(tty, 0, TTY_PARITY))
621 copied++;
622
623 dev_notice(port->dev, "parity error");
624 }
625
626 if (copied)
627 tty_flip_buffer_push(tty);
628
629 return copied;
630 }
631
632 static int sci_handle_fifo_overrun(struct uart_port *port)
633 {
634 struct tty_struct *tty = port->state->port.tty;
635 int copied = 0;
636
637 if (port->type != PORT_SCIF)
638 return 0;
639
640 if ((sci_in(port, SCLSR) & SCIF_ORER) != 0) {
641 sci_out(port, SCLSR, 0);
642
643 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
644 tty_flip_buffer_push(tty);
645
646 dev_notice(port->dev, "overrun error\n");
647 copied++;
648 }
649
650 return copied;
651 }
652
653 static int sci_handle_breaks(struct uart_port *port)
654 {
655 int copied = 0;
656 unsigned short status = sci_in(port, SCxSR);
657 struct tty_struct *tty = port->state->port.tty;
658 struct sci_port *s = to_sci_port(port);
659
660 if (uart_handle_break(port))
661 return 0;
662
663 if (!s->break_flag && status & SCxSR_BRK(port)) {
664 #if defined(CONFIG_CPU_SH3)
665 /* Debounce break */
666 s->break_flag = 1;
667 #endif
668 /* Notify of BREAK */
669 if (tty_insert_flip_char(tty, 0, TTY_BREAK))
670 copied++;
671
672 dev_dbg(port->dev, "BREAK detected\n");
673 }
674
675 if (copied)
676 tty_flip_buffer_push(tty);
677
678 copied += sci_handle_fifo_overrun(port);
679
680 return copied;
681 }
682
683 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
684 {
685 #ifdef CONFIG_SERIAL_SH_SCI_DMA
686 struct uart_port *port = ptr;
687 struct sci_port *s = to_sci_port(port);
688
689 if (s->chan_rx) {
690 u16 scr = sci_in(port, SCSCR);
691 u16 ssr = sci_in(port, SCxSR);
692
693 /* Disable future Rx interrupts */
694 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
695 disable_irq_nosync(irq);
696 scr |= 0x4000;
697 } else {
698 scr &= ~SCSCR_RIE;
699 }
700 sci_out(port, SCSCR, scr);
701 /* Clear current interrupt */
702 sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
703 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
704 jiffies, s->rx_timeout);
705 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
706
707 return IRQ_HANDLED;
708 }
709 #endif
710
711 /* I think sci_receive_chars has to be called irrespective
712 * of whether the I_IXOFF is set, otherwise, how is the interrupt
713 * to be disabled?
714 */
715 sci_receive_chars(ptr);
716
717 return IRQ_HANDLED;
718 }
719
720 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
721 {
722 struct uart_port *port = ptr;
723 unsigned long flags;
724
725 spin_lock_irqsave(&port->lock, flags);
726 sci_transmit_chars(port);
727 spin_unlock_irqrestore(&port->lock, flags);
728
729 return IRQ_HANDLED;
730 }
731
732 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
733 {
734 struct uart_port *port = ptr;
735
736 /* Handle errors */
737 if (port->type == PORT_SCI) {
738 if (sci_handle_errors(port)) {
739 /* discard character in rx buffer */
740 sci_in(port, SCxSR);
741 sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
742 }
743 } else {
744 sci_handle_fifo_overrun(port);
745 sci_rx_interrupt(irq, ptr);
746 }
747
748 sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
749
750 /* Kick the transmission */
751 sci_tx_interrupt(irq, ptr);
752
753 return IRQ_HANDLED;
754 }
755
756 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
757 {
758 struct uart_port *port = ptr;
759
760 /* Handle BREAKs */
761 sci_handle_breaks(port);
762 sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
763
764 return IRQ_HANDLED;
765 }
766
767 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
768 {
769 /*
770 * Not all ports (such as SCIFA) will support REIE. Rather than
771 * special-casing the port type, we check the port initialization
772 * IRQ enable mask to see whether the IRQ is desired at all. If
773 * it's unset, it's logically inferred that there's no point in
774 * testing for it.
775 */
776 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
777 }
778
779 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
780 {
781 unsigned short ssr_status, scr_status, err_enabled;
782 struct uart_port *port = ptr;
783 struct sci_port *s = to_sci_port(port);
784 irqreturn_t ret = IRQ_NONE;
785
786 ssr_status = sci_in(port, SCxSR);
787 scr_status = sci_in(port, SCSCR);
788 err_enabled = scr_status & port_rx_irq_mask(port);
789
790 /* Tx Interrupt */
791 if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
792 !s->chan_tx)
793 ret = sci_tx_interrupt(irq, ptr);
794
795 /*
796 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
797 * DR flags
798 */
799 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
800 (scr_status & SCSCR_RIE))
801 ret = sci_rx_interrupt(irq, ptr);
802
803 /* Error Interrupt */
804 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
805 ret = sci_er_interrupt(irq, ptr);
806
807 /* Break Interrupt */
808 if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
809 ret = sci_br_interrupt(irq, ptr);
810
811 return ret;
812 }
813
814 /*
815 * Here we define a transistion notifier so that we can update all of our
816 * ports' baud rate when the peripheral clock changes.
817 */
818 static int sci_notifier(struct notifier_block *self,
819 unsigned long phase, void *p)
820 {
821 struct sci_port *sci_port;
822 unsigned long flags;
823
824 sci_port = container_of(self, struct sci_port, freq_transition);
825
826 if ((phase == CPUFREQ_POSTCHANGE) ||
827 (phase == CPUFREQ_RESUMECHANGE)) {
828 struct uart_port *port = &sci_port->port;
829
830 spin_lock_irqsave(&port->lock, flags);
831 port->uartclk = clk_get_rate(sci_port->iclk);
832 spin_unlock_irqrestore(&port->lock, flags);
833 }
834
835 return NOTIFY_OK;
836 }
837
838 static void sci_clk_enable(struct uart_port *port)
839 {
840 struct sci_port *sci_port = to_sci_port(port);
841
842 clk_enable(sci_port->iclk);
843 sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
844 clk_enable(sci_port->fclk);
845 }
846
847 static void sci_clk_disable(struct uart_port *port)
848 {
849 struct sci_port *sci_port = to_sci_port(port);
850
851 clk_disable(sci_port->fclk);
852 clk_disable(sci_port->iclk);
853 }
854
855 static int sci_request_irq(struct sci_port *port)
856 {
857 int i;
858 irqreturn_t (*handlers[4])(int irq, void *ptr) = {
859 sci_er_interrupt, sci_rx_interrupt, sci_tx_interrupt,
860 sci_br_interrupt,
861 };
862 const char *desc[] = { "SCI Receive Error", "SCI Receive Data Full",
863 "SCI Transmit Data Empty", "SCI Break" };
864
865 if (port->cfg->irqs[0] == port->cfg->irqs[1]) {
866 if (unlikely(!port->cfg->irqs[0]))
867 return -ENODEV;
868
869 if (request_irq(port->cfg->irqs[0], sci_mpxed_interrupt,
870 IRQF_DISABLED, "sci", port)) {
871 dev_err(port->port.dev, "Can't allocate IRQ\n");
872 return -ENODEV;
873 }
874 } else {
875 for (i = 0; i < ARRAY_SIZE(handlers); i++) {
876 if (unlikely(!port->cfg->irqs[i]))
877 continue;
878
879 if (request_irq(port->cfg->irqs[i], handlers[i],
880 IRQF_DISABLED, desc[i], port)) {
881 dev_err(port->port.dev, "Can't allocate IRQ\n");
882 return -ENODEV;
883 }
884 }
885 }
886
887 return 0;
888 }
889
890 static void sci_free_irq(struct sci_port *port)
891 {
892 int i;
893
894 if (port->cfg->irqs[0] == port->cfg->irqs[1])
895 free_irq(port->cfg->irqs[0], port);
896 else {
897 for (i = 0; i < ARRAY_SIZE(port->cfg->irqs); i++) {
898 if (!port->cfg->irqs[i])
899 continue;
900
901 free_irq(port->cfg->irqs[i], port);
902 }
903 }
904 }
905
906 static unsigned int sci_tx_empty(struct uart_port *port)
907 {
908 unsigned short status = sci_in(port, SCxSR);
909 unsigned short in_tx_fifo = scif_txfill(port);
910
911 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
912 }
913
914 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
915 {
916 /* This routine is used for seting signals of: DTR, DCD, CTS/RTS */
917 /* We use SCIF's hardware for CTS/RTS, so don't need any for that. */
918 /* If you have signals for DTR and DCD, please implement here. */
919 }
920
921 static unsigned int sci_get_mctrl(struct uart_port *port)
922 {
923 /* This routine is used for getting signals of: DTR, DCD, DSR, RI,
924 and CTS/RTS */
925
926 return TIOCM_DTR | TIOCM_RTS | TIOCM_DSR;
927 }
928
929 #ifdef CONFIG_SERIAL_SH_SCI_DMA
930 static void sci_dma_tx_complete(void *arg)
931 {
932 struct sci_port *s = arg;
933 struct uart_port *port = &s->port;
934 struct circ_buf *xmit = &port->state->xmit;
935 unsigned long flags;
936
937 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
938
939 spin_lock_irqsave(&port->lock, flags);
940
941 xmit->tail += sg_dma_len(&s->sg_tx);
942 xmit->tail &= UART_XMIT_SIZE - 1;
943
944 port->icount.tx += sg_dma_len(&s->sg_tx);
945
946 async_tx_ack(s->desc_tx);
947 s->cookie_tx = -EINVAL;
948 s->desc_tx = NULL;
949
950 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
951 uart_write_wakeup(port);
952
953 if (!uart_circ_empty(xmit)) {
954 schedule_work(&s->work_tx);
955 } else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
956 u16 ctrl = sci_in(port, SCSCR);
957 sci_out(port, SCSCR, ctrl & ~SCSCR_TIE);
958 }
959
960 spin_unlock_irqrestore(&port->lock, flags);
961 }
962
963 /* Locking: called with port lock held */
964 static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,
965 size_t count)
966 {
967 struct uart_port *port = &s->port;
968 int i, active, room;
969
970 room = tty_buffer_request_room(tty, count);
971
972 if (s->active_rx == s->cookie_rx[0]) {
973 active = 0;
974 } else if (s->active_rx == s->cookie_rx[1]) {
975 active = 1;
976 } else {
977 dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
978 return 0;
979 }
980
981 if (room < count)
982 dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
983 count - room);
984 if (!room)
985 return room;
986
987 for (i = 0; i < room; i++)
988 tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
989 TTY_NORMAL);
990
991 port->icount.rx += room;
992
993 return room;
994 }
995
996 static void sci_dma_rx_complete(void *arg)
997 {
998 struct sci_port *s = arg;
999 struct uart_port *port = &s->port;
1000 struct tty_struct *tty = port->state->port.tty;
1001 unsigned long flags;
1002 int count;
1003
1004 dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
1005
1006 spin_lock_irqsave(&port->lock, flags);
1007
1008 count = sci_dma_rx_push(s, tty, s->buf_len_rx);
1009
1010 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1011
1012 spin_unlock_irqrestore(&port->lock, flags);
1013
1014 if (count)
1015 tty_flip_buffer_push(tty);
1016
1017 schedule_work(&s->work_rx);
1018 }
1019
1020 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1021 {
1022 struct dma_chan *chan = s->chan_rx;
1023 struct uart_port *port = &s->port;
1024
1025 s->chan_rx = NULL;
1026 s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1027 dma_release_channel(chan);
1028 if (sg_dma_address(&s->sg_rx[0]))
1029 dma_free_coherent(port->dev, s->buf_len_rx * 2,
1030 sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
1031 if (enable_pio)
1032 sci_start_rx(port);
1033 }
1034
1035 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1036 {
1037 struct dma_chan *chan = s->chan_tx;
1038 struct uart_port *port = &s->port;
1039
1040 s->chan_tx = NULL;
1041 s->cookie_tx = -EINVAL;
1042 dma_release_channel(chan);
1043 if (enable_pio)
1044 sci_start_tx(port);
1045 }
1046
1047 static void sci_submit_rx(struct sci_port *s)
1048 {
1049 struct dma_chan *chan = s->chan_rx;
1050 int i;
1051
1052 for (i = 0; i < 2; i++) {
1053 struct scatterlist *sg = &s->sg_rx[i];
1054 struct dma_async_tx_descriptor *desc;
1055
1056 desc = chan->device->device_prep_slave_sg(chan,
1057 sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);
1058
1059 if (desc) {
1060 s->desc_rx[i] = desc;
1061 desc->callback = sci_dma_rx_complete;
1062 desc->callback_param = s;
1063 s->cookie_rx[i] = desc->tx_submit(desc);
1064 }
1065
1066 if (!desc || s->cookie_rx[i] < 0) {
1067 if (i) {
1068 async_tx_ack(s->desc_rx[0]);
1069 s->cookie_rx[0] = -EINVAL;
1070 }
1071 if (desc) {
1072 async_tx_ack(desc);
1073 s->cookie_rx[i] = -EINVAL;
1074 }
1075 dev_warn(s->port.dev,
1076 "failed to re-start DMA, using PIO\n");
1077 sci_rx_dma_release(s, true);
1078 return;
1079 }
1080 dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1081 s->cookie_rx[i], i);
1082 }
1083
1084 s->active_rx = s->cookie_rx[0];
1085
1086 dma_async_issue_pending(chan);
1087 }
1088
1089 static void work_fn_rx(struct work_struct *work)
1090 {
1091 struct sci_port *s = container_of(work, struct sci_port, work_rx);
1092 struct uart_port *port = &s->port;
1093 struct dma_async_tx_descriptor *desc;
1094 int new;
1095
1096 if (s->active_rx == s->cookie_rx[0]) {
1097 new = 0;
1098 } else if (s->active_rx == s->cookie_rx[1]) {
1099 new = 1;
1100 } else {
1101 dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1102 return;
1103 }
1104 desc = s->desc_rx[new];
1105
1106 if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
1107 DMA_SUCCESS) {
1108 /* Handle incomplete DMA receive */
1109 struct tty_struct *tty = port->state->port.tty;
1110 struct dma_chan *chan = s->chan_rx;
1111 struct sh_desc *sh_desc = container_of(desc, struct sh_desc,
1112 async_tx);
1113 unsigned long flags;
1114 int count;
1115
1116 chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
1117 dev_dbg(port->dev, "Read %u bytes with cookie %d\n",
1118 sh_desc->partial, sh_desc->cookie);
1119
1120 spin_lock_irqsave(&port->lock, flags);
1121 count = sci_dma_rx_push(s, tty, sh_desc->partial);
1122 spin_unlock_irqrestore(&port->lock, flags);
1123
1124 if (count)
1125 tty_flip_buffer_push(tty);
1126
1127 sci_submit_rx(s);
1128
1129 return;
1130 }
1131
1132 s->cookie_rx[new] = desc->tx_submit(desc);
1133 if (s->cookie_rx[new] < 0) {
1134 dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1135 sci_rx_dma_release(s, true);
1136 return;
1137 }
1138
1139 s->active_rx = s->cookie_rx[!new];
1140
1141 dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
1142 s->cookie_rx[new], new, s->active_rx);
1143 }
1144
1145 static void work_fn_tx(struct work_struct *work)
1146 {
1147 struct sci_port *s = container_of(work, struct sci_port, work_tx);
1148 struct dma_async_tx_descriptor *desc;
1149 struct dma_chan *chan = s->chan_tx;
1150 struct uart_port *port = &s->port;
1151 struct circ_buf *xmit = &port->state->xmit;
1152 struct scatterlist *sg = &s->sg_tx;
1153
1154 /*
1155 * DMA is idle now.
1156 * Port xmit buffer is already mapped, and it is one page... Just adjust
1157 * offsets and lengths. Since it is a circular buffer, we have to
1158 * transmit till the end, and then the rest. Take the port lock to get a
1159 * consistent xmit buffer state.
1160 */
1161 spin_lock_irq(&port->lock);
1162 sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
1163 sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
1164 sg->offset;
1165 sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1166 CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1167 spin_unlock_irq(&port->lock);
1168
1169 BUG_ON(!sg_dma_len(sg));
1170
1171 desc = chan->device->device_prep_slave_sg(chan,
1172 sg, s->sg_len_tx, DMA_TO_DEVICE,
1173 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1174 if (!desc) {
1175 /* switch to PIO */
1176 sci_tx_dma_release(s, true);
1177 return;
1178 }
1179
1180 dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
1181
1182 spin_lock_irq(&port->lock);
1183 s->desc_tx = desc;
1184 desc->callback = sci_dma_tx_complete;
1185 desc->callback_param = s;
1186 spin_unlock_irq(&port->lock);
1187 s->cookie_tx = desc->tx_submit(desc);
1188 if (s->cookie_tx < 0) {
1189 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1190 /* switch to PIO */
1191 sci_tx_dma_release(s, true);
1192 return;
1193 }
1194
1195 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,
1196 xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1197
1198 dma_async_issue_pending(chan);
1199 }
1200 #endif
1201
1202 static void sci_start_tx(struct uart_port *port)
1203 {
1204 struct sci_port *s = to_sci_port(port);
1205 unsigned short ctrl;
1206
1207 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1208 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1209 u16 new, scr = sci_in(port, SCSCR);
1210 if (s->chan_tx)
1211 new = scr | 0x8000;
1212 else
1213 new = scr & ~0x8000;
1214 if (new != scr)
1215 sci_out(port, SCSCR, new);
1216 }
1217
1218 if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
1219 s->cookie_tx < 0)
1220 schedule_work(&s->work_tx);
1221 #endif
1222
1223 if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1224 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
1225 ctrl = sci_in(port, SCSCR);
1226 sci_out(port, SCSCR, ctrl | SCSCR_TIE);
1227 }
1228 }
1229
1230 static void sci_stop_tx(struct uart_port *port)
1231 {
1232 unsigned short ctrl;
1233
1234 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
1235 ctrl = sci_in(port, SCSCR);
1236
1237 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1238 ctrl &= ~0x8000;
1239
1240 ctrl &= ~SCSCR_TIE;
1241
1242 sci_out(port, SCSCR, ctrl);
1243 }
1244
1245 static void sci_start_rx(struct uart_port *port)
1246 {
1247 unsigned short ctrl;
1248
1249 ctrl = sci_in(port, SCSCR) | port_rx_irq_mask(port);
1250
1251 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1252 ctrl &= ~0x4000;
1253
1254 sci_out(port, SCSCR, ctrl);
1255 }
1256
1257 static void sci_stop_rx(struct uart_port *port)
1258 {
1259 unsigned short ctrl;
1260
1261 ctrl = sci_in(port, SCSCR);
1262
1263 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1264 ctrl &= ~0x4000;
1265
1266 ctrl &= ~port_rx_irq_mask(port);
1267
1268 sci_out(port, SCSCR, ctrl);
1269 }
1270
1271 static void sci_enable_ms(struct uart_port *port)
1272 {
1273 /* Nothing here yet .. */
1274 }
1275
1276 static void sci_break_ctl(struct uart_port *port, int break_state)
1277 {
1278 /* Nothing here yet .. */
1279 }
1280
1281 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1282 static bool filter(struct dma_chan *chan, void *slave)
1283 {
1284 struct sh_dmae_slave *param = slave;
1285
1286 dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
1287 param->slave_id);
1288
1289 if (param->dma_dev == chan->device->dev) {
1290 chan->private = param;
1291 return true;
1292 } else {
1293 return false;
1294 }
1295 }
1296
1297 static void rx_timer_fn(unsigned long arg)
1298 {
1299 struct sci_port *s = (struct sci_port *)arg;
1300 struct uart_port *port = &s->port;
1301 u16 scr = sci_in(port, SCSCR);
1302
1303 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1304 scr &= ~0x4000;
1305 enable_irq(s->cfg->irqs[1]);
1306 }
1307 sci_out(port, SCSCR, scr | SCSCR_RIE);
1308 dev_dbg(port->dev, "DMA Rx timed out\n");
1309 schedule_work(&s->work_rx);
1310 }
1311
1312 static void sci_request_dma(struct uart_port *port)
1313 {
1314 struct sci_port *s = to_sci_port(port);
1315 struct sh_dmae_slave *param;
1316 struct dma_chan *chan;
1317 dma_cap_mask_t mask;
1318 int nent;
1319
1320 dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
1321 port->line, s->cfg->dma_dev);
1322
1323 if (!s->cfg->dma_dev)
1324 return;
1325
1326 dma_cap_zero(mask);
1327 dma_cap_set(DMA_SLAVE, mask);
1328
1329 param = &s->param_tx;
1330
1331 /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
1332 param->slave_id = s->cfg->dma_slave_tx;
1333 param->dma_dev = s->cfg->dma_dev;
1334
1335 s->cookie_tx = -EINVAL;
1336 chan = dma_request_channel(mask, filter, param);
1337 dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1338 if (chan) {
1339 s->chan_tx = chan;
1340 sg_init_table(&s->sg_tx, 1);
1341 /* UART circular tx buffer is an aligned page. */
1342 BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);
1343 sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
1344 UART_XMIT_SIZE, (int)port->state->xmit.buf & ~PAGE_MASK);
1345 nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
1346 if (!nent)
1347 sci_tx_dma_release(s, false);
1348 else
1349 dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
1350 sg_dma_len(&s->sg_tx),
1351 port->state->xmit.buf, sg_dma_address(&s->sg_tx));
1352
1353 s->sg_len_tx = nent;
1354
1355 INIT_WORK(&s->work_tx, work_fn_tx);
1356 }
1357
1358 param = &s->param_rx;
1359
1360 /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
1361 param->slave_id = s->cfg->dma_slave_rx;
1362 param->dma_dev = s->cfg->dma_dev;
1363
1364 chan = dma_request_channel(mask, filter, param);
1365 dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1366 if (chan) {
1367 dma_addr_t dma[2];
1368 void *buf[2];
1369 int i;
1370
1371 s->chan_rx = chan;
1372
1373 s->buf_len_rx = 2 * max(16, (int)port->fifosize);
1374 buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
1375 &dma[0], GFP_KERNEL);
1376
1377 if (!buf[0]) {
1378 dev_warn(port->dev,
1379 "failed to allocate dma buffer, using PIO\n");
1380 sci_rx_dma_release(s, true);
1381 return;
1382 }
1383
1384 buf[1] = buf[0] + s->buf_len_rx;
1385 dma[1] = dma[0] + s->buf_len_rx;
1386
1387 for (i = 0; i < 2; i++) {
1388 struct scatterlist *sg = &s->sg_rx[i];
1389
1390 sg_init_table(sg, 1);
1391 sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
1392 (int)buf[i] & ~PAGE_MASK);
1393 sg_dma_address(sg) = dma[i];
1394 }
1395
1396 INIT_WORK(&s->work_rx, work_fn_rx);
1397 setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1398
1399 sci_submit_rx(s);
1400 }
1401 }
1402
1403 static void sci_free_dma(struct uart_port *port)
1404 {
1405 struct sci_port *s = to_sci_port(port);
1406
1407 if (!s->cfg->dma_dev)
1408 return;
1409
1410 if (s->chan_tx)
1411 sci_tx_dma_release(s, false);
1412 if (s->chan_rx)
1413 sci_rx_dma_release(s, false);
1414 }
1415 #else
1416 static inline void sci_request_dma(struct uart_port *port)
1417 {
1418 }
1419
1420 static inline void sci_free_dma(struct uart_port *port)
1421 {
1422 }
1423 #endif
1424
1425 static int sci_startup(struct uart_port *port)
1426 {
1427 struct sci_port *s = to_sci_port(port);
1428 int ret;
1429
1430 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1431
1432 if (s->enable)
1433 s->enable(port);
1434
1435 ret = sci_request_irq(s);
1436 if (unlikely(ret < 0))
1437 return ret;
1438
1439 sci_request_dma(port);
1440
1441 sci_start_tx(port);
1442 sci_start_rx(port);
1443
1444 return 0;
1445 }
1446
1447 static void sci_shutdown(struct uart_port *port)
1448 {
1449 struct sci_port *s = to_sci_port(port);
1450
1451 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1452
1453 sci_stop_rx(port);
1454 sci_stop_tx(port);
1455
1456 sci_free_dma(port);
1457 sci_free_irq(s);
1458
1459 if (s->disable)
1460 s->disable(port);
1461 }
1462
1463 static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps,
1464 unsigned long freq)
1465 {
1466 switch (algo_id) {
1467 case SCBRR_ALGO_1:
1468 return ((freq + 16 * bps) / (16 * bps) - 1);
1469 case SCBRR_ALGO_2:
1470 return ((freq + 16 * bps) / (32 * bps) - 1);
1471 case SCBRR_ALGO_3:
1472 return (((freq * 2) + 16 * bps) / (16 * bps) - 1);
1473 case SCBRR_ALGO_4:
1474 return (((freq * 2) + 16 * bps) / (32 * bps) - 1);
1475 case SCBRR_ALGO_5:
1476 return (((freq * 1000 / 32) / bps) - 1);
1477 }
1478
1479 /* Warn, but use a safe default */
1480 WARN_ON(1);
1481
1482 return ((freq + 16 * bps) / (32 * bps) - 1);
1483 }
1484
1485 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
1486 struct ktermios *old)
1487 {
1488 struct sci_port *s = to_sci_port(port);
1489 unsigned int status, baud, smr_val, max_baud;
1490 int t = -1;
1491 u16 scfcr = 0;
1492
1493 /*
1494 * earlyprintk comes here early on with port->uartclk set to zero.
1495 * the clock framework is not up and running at this point so here
1496 * we assume that 115200 is the maximum baud rate. please note that
1497 * the baud rate is not programmed during earlyprintk - it is assumed
1498 * that the previous boot loader has enabled required clocks and
1499 * setup the baud rate generator hardware for us already.
1500 */
1501 max_baud = port->uartclk ? port->uartclk / 16 : 115200;
1502
1503 baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
1504 if (likely(baud && port->uartclk))
1505 t = sci_scbrr_calc(s->cfg->scbrr_algo_id, baud, port->uartclk);
1506
1507 do {
1508 status = sci_in(port, SCxSR);
1509 } while (!(status & SCxSR_TEND(port)));
1510
1511 sci_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */
1512
1513 if (port->type != PORT_SCI)
1514 sci_out(port, SCFCR, scfcr | SCFCR_RFRST | SCFCR_TFRST);
1515
1516 smr_val = sci_in(port, SCSMR) & 3;
1517
1518 if ((termios->c_cflag & CSIZE) == CS7)
1519 smr_val |= 0x40;
1520 if (termios->c_cflag & PARENB)
1521 smr_val |= 0x20;
1522 if (termios->c_cflag & PARODD)
1523 smr_val |= 0x30;
1524 if (termios->c_cflag & CSTOPB)
1525 smr_val |= 0x08;
1526
1527 uart_update_timeout(port, termios->c_cflag, baud);
1528
1529 sci_out(port, SCSMR, smr_val);
1530
1531 dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,
1532 s->cfg->scscr);
1533
1534 if (t > 0) {
1535 if (t >= 256) {
1536 sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
1537 t >>= 2;
1538 } else
1539 sci_out(port, SCSMR, sci_in(port, SCSMR) & ~3);
1540
1541 sci_out(port, SCBRR, t);
1542 udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
1543 }
1544
1545 sci_init_pins(port, termios->c_cflag);
1546 sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
1547
1548 sci_out(port, SCSCR, s->cfg->scscr);
1549
1550 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1551 /*
1552 * Calculate delay for 1.5 DMA buffers: see
1553 * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
1554 * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
1555 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
1556 * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
1557 * sizes), but it has been found out experimentally, that this is not
1558 * enough: the driver too often needlessly runs on a DMA timeout. 20ms
1559 * as a minimum seem to work perfectly.
1560 */
1561 if (s->chan_rx) {
1562 s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
1563 port->fifosize / 2;
1564 dev_dbg(port->dev,
1565 "DMA Rx t-out %ums, tty t-out %u jiffies\n",
1566 s->rx_timeout * 1000 / HZ, port->timeout);
1567 if (s->rx_timeout < msecs_to_jiffies(20))
1568 s->rx_timeout = msecs_to_jiffies(20);
1569 }
1570 #endif
1571
1572 if ((termios->c_cflag & CREAD) != 0)
1573 sci_start_rx(port);
1574 }
1575
1576 static const char *sci_type(struct uart_port *port)
1577 {
1578 switch (port->type) {
1579 case PORT_IRDA:
1580 return "irda";
1581 case PORT_SCI:
1582 return "sci";
1583 case PORT_SCIF:
1584 return "scif";
1585 case PORT_SCIFA:
1586 return "scifa";
1587 case PORT_SCIFB:
1588 return "scifb";
1589 }
1590
1591 return NULL;
1592 }
1593
1594 static inline unsigned long sci_port_size(struct uart_port *port)
1595 {
1596 /*
1597 * Pick an arbitrary size that encapsulates all of the base
1598 * registers by default. This can be optimized later, or derived
1599 * from platform resource data at such a time that ports begin to
1600 * behave more erratically.
1601 */
1602 return 64;
1603 }
1604
1605 static void sci_release_port(struct uart_port *port)
1606 {
1607 if (port->flags & UPF_IOREMAP) {
1608 iounmap(port->membase);
1609 port->membase = NULL;
1610 }
1611
1612 release_mem_region(port->mapbase, sci_port_size(port));
1613 }
1614
1615 static int sci_request_port(struct uart_port *port)
1616 {
1617 unsigned long size = sci_port_size(port);
1618 struct resource *res;
1619
1620 res = request_mem_region(port->mapbase, size, sci_type(port));
1621 if (unlikely(res == NULL))
1622 return -EBUSY;
1623
1624 if (port->flags & UPF_IOREMAP) {
1625 port->membase = ioremap_nocache(port->mapbase, size);
1626 if (unlikely(!port->membase)) {
1627 dev_err(port->dev, "can't remap port#%d\n", port->line);
1628 release_resource(res);
1629 return -ENXIO;
1630 }
1631 } else {
1632 /*
1633 * For the simple (and majority of) cases where we don't
1634 * need to do any remapping, just cast the cookie
1635 * directly.
1636 */
1637 port->membase = (void __iomem *)port->mapbase;
1638 }
1639
1640 return 0;
1641 }
1642
1643 static void sci_config_port(struct uart_port *port, int flags)
1644 {
1645 if (flags & UART_CONFIG_TYPE) {
1646 struct sci_port *sport = to_sci_port(port);
1647
1648 port->type = sport->cfg->type;
1649 sci_request_port(port);
1650 }
1651 }
1652
1653 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
1654 {
1655 struct sci_port *s = to_sci_port(port);
1656
1657 if (ser->irq != s->cfg->irqs[SCIx_TXI_IRQ] || ser->irq > nr_irqs)
1658 return -EINVAL;
1659 if (ser->baud_base < 2400)
1660 /* No paper tape reader for Mitch.. */
1661 return -EINVAL;
1662
1663 return 0;
1664 }
1665
1666 static struct uart_ops sci_uart_ops = {
1667 .tx_empty = sci_tx_empty,
1668 .set_mctrl = sci_set_mctrl,
1669 .get_mctrl = sci_get_mctrl,
1670 .start_tx = sci_start_tx,
1671 .stop_tx = sci_stop_tx,
1672 .stop_rx = sci_stop_rx,
1673 .enable_ms = sci_enable_ms,
1674 .break_ctl = sci_break_ctl,
1675 .startup = sci_startup,
1676 .shutdown = sci_shutdown,
1677 .set_termios = sci_set_termios,
1678 .type = sci_type,
1679 .release_port = sci_release_port,
1680 .request_port = sci_request_port,
1681 .config_port = sci_config_port,
1682 .verify_port = sci_verify_port,
1683 #ifdef CONFIG_CONSOLE_POLL
1684 .poll_get_char = sci_poll_get_char,
1685 .poll_put_char = sci_poll_put_char,
1686 #endif
1687 };
1688
1689 static int __devinit sci_init_single(struct platform_device *dev,
1690 struct sci_port *sci_port,
1691 unsigned int index,
1692 struct plat_sci_port *p)
1693 {
1694 struct uart_port *port = &sci_port->port;
1695
1696 port->ops = &sci_uart_ops;
1697 port->iotype = UPIO_MEM;
1698 port->line = index;
1699
1700 switch (p->type) {
1701 case PORT_SCIFB:
1702 port->fifosize = 256;
1703 break;
1704 case PORT_SCIFA:
1705 port->fifosize = 64;
1706 break;
1707 case PORT_SCIF:
1708 port->fifosize = 16;
1709 break;
1710 default:
1711 port->fifosize = 1;
1712 break;
1713 }
1714
1715 if (dev) {
1716 sci_port->iclk = clk_get(&dev->dev, "sci_ick");
1717 if (IS_ERR(sci_port->iclk)) {
1718 sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
1719 if (IS_ERR(sci_port->iclk)) {
1720 dev_err(&dev->dev, "can't get iclk\n");
1721 return PTR_ERR(sci_port->iclk);
1722 }
1723 }
1724
1725 /*
1726 * The function clock is optional, ignore it if we can't
1727 * find it.
1728 */
1729 sci_port->fclk = clk_get(&dev->dev, "sci_fck");
1730 if (IS_ERR(sci_port->fclk))
1731 sci_port->fclk = NULL;
1732
1733 sci_port->enable = sci_clk_enable;
1734 sci_port->disable = sci_clk_disable;
1735 port->dev = &dev->dev;
1736 }
1737
1738 sci_port->break_timer.data = (unsigned long)sci_port;
1739 sci_port->break_timer.function = sci_break_timer;
1740 init_timer(&sci_port->break_timer);
1741
1742 sci_port->cfg = p;
1743
1744 port->mapbase = p->mapbase;
1745 port->type = p->type;
1746 port->flags = p->flags;
1747
1748 /*
1749 * The UART port needs an IRQ value, so we peg this to the TX IRQ
1750 * for the multi-IRQ ports, which is where we are primarily
1751 * concerned with the shutdown path synchronization.
1752 *
1753 * For the muxed case there's nothing more to do.
1754 */
1755 port->irq = p->irqs[SCIx_TXI_IRQ];
1756
1757 if (p->dma_dev)
1758 dev_dbg(port->dev, "DMA device %p, tx %d, rx %d\n",
1759 p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
1760
1761 return 0;
1762 }
1763
1764 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
1765 static struct tty_driver *serial_console_device(struct console *co, int *index)
1766 {
1767 struct uart_driver *p = &sci_uart_driver;
1768 *index = co->index;
1769 return p->tty_driver;
1770 }
1771
1772 static void serial_console_putchar(struct uart_port *port, int ch)
1773 {
1774 sci_poll_put_char(port, ch);
1775 }
1776
1777 /*
1778 * Print a string to the serial port trying not to disturb
1779 * any possible real use of the port...
1780 */
1781 static void serial_console_write(struct console *co, const char *s,
1782 unsigned count)
1783 {
1784 struct uart_port *port = co->data;
1785 struct sci_port *sci_port = to_sci_port(port);
1786 unsigned short bits;
1787
1788 if (sci_port->enable)
1789 sci_port->enable(port);
1790
1791 uart_console_write(port, s, count, serial_console_putchar);
1792
1793 /* wait until fifo is empty and last bit has been transmitted */
1794 bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
1795 while ((sci_in(port, SCxSR) & bits) != bits)
1796 cpu_relax();
1797
1798 if (sci_port->disable)
1799 sci_port->disable(port);
1800 }
1801
1802 static int __devinit serial_console_setup(struct console *co, char *options)
1803 {
1804 struct sci_port *sci_port;
1805 struct uart_port *port;
1806 int baud = 115200;
1807 int bits = 8;
1808 int parity = 'n';
1809 int flow = 'n';
1810 int ret;
1811
1812 /*
1813 * Check whether an invalid uart number has been specified, and
1814 * if so, search for the first available port that does have
1815 * console support.
1816 */
1817 if (co->index >= SCI_NPORTS)
1818 co->index = 0;
1819
1820 if (co->data) {
1821 port = co->data;
1822 sci_port = to_sci_port(port);
1823 } else {
1824 sci_port = &sci_ports[co->index];
1825 port = &sci_port->port;
1826 co->data = port;
1827 }
1828
1829 /*
1830 * Also need to check port->type, we don't actually have any
1831 * UPIO_PORT ports, but uart_report_port() handily misreports
1832 * it anyways if we don't have a port available by the time this is
1833 * called.
1834 */
1835 if (!port->type)
1836 return -ENODEV;
1837
1838 sci_config_port(port, 0);
1839
1840 if (sci_port->enable)
1841 sci_port->enable(port);
1842
1843 if (options)
1844 uart_parse_options(options, &baud, &parity, &bits, &flow);
1845
1846 ret = uart_set_options(port, co, baud, parity, bits, flow);
1847 #if defined(__H8300H__) || defined(__H8300S__)
1848 /* disable rx interrupt */
1849 if (ret == 0)
1850 sci_stop_rx(port);
1851 #endif
1852 /* TODO: disable clock */
1853 return ret;
1854 }
1855
1856 static struct console serial_console = {
1857 .name = "ttySC",
1858 .device = serial_console_device,
1859 .write = serial_console_write,
1860 .setup = serial_console_setup,
1861 .flags = CON_PRINTBUFFER,
1862 .index = -1,
1863 };
1864
1865 static int __init sci_console_init(void)
1866 {
1867 register_console(&serial_console);
1868 return 0;
1869 }
1870 console_initcall(sci_console_init);
1871
1872 static struct sci_port early_serial_port;
1873 static struct console early_serial_console = {
1874 .name = "early_ttySC",
1875 .write = serial_console_write,
1876 .flags = CON_PRINTBUFFER,
1877 };
1878 static char early_serial_buf[32];
1879
1880 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
1881
1882 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
1883 #define SCI_CONSOLE (&serial_console)
1884 #else
1885 #define SCI_CONSOLE 0
1886 #endif
1887
1888 static char banner[] __initdata =
1889 KERN_INFO "SuperH SCI(F) driver initialized\n";
1890
1891 static struct uart_driver sci_uart_driver = {
1892 .owner = THIS_MODULE,
1893 .driver_name = "sci",
1894 .dev_name = "ttySC",
1895 .major = SCI_MAJOR,
1896 .minor = SCI_MINOR_START,
1897 .nr = SCI_NPORTS,
1898 .cons = SCI_CONSOLE,
1899 };
1900
1901 static int sci_remove(struct platform_device *dev)
1902 {
1903 struct sci_port *port = platform_get_drvdata(dev);
1904
1905 cpufreq_unregister_notifier(&port->freq_transition,
1906 CPUFREQ_TRANSITION_NOTIFIER);
1907
1908 uart_remove_one_port(&sci_uart_driver, &port->port);
1909
1910 clk_put(port->iclk);
1911 clk_put(port->fclk);
1912
1913 return 0;
1914 }
1915
1916 static int __devinit sci_probe_single(struct platform_device *dev,
1917 unsigned int index,
1918 struct plat_sci_port *p,
1919 struct sci_port *sciport)
1920 {
1921 int ret;
1922
1923 /* Sanity check */
1924 if (unlikely(index >= SCI_NPORTS)) {
1925 dev_notice(&dev->dev, "Attempting to register port "
1926 "%d when only %d are available.\n",
1927 index+1, SCI_NPORTS);
1928 dev_notice(&dev->dev, "Consider bumping "
1929 "CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
1930 return 0;
1931 }
1932
1933 ret = sci_init_single(dev, sciport, index, p);
1934 if (ret)
1935 return ret;
1936
1937 return uart_add_one_port(&sci_uart_driver, &sciport->port);
1938 }
1939
1940 /*
1941 * Register a set of serial devices attached to a platform device. The
1942 * list is terminated with a zero flags entry, which means we expect
1943 * all entries to have at least UPF_BOOT_AUTOCONF set. Platforms that need
1944 * remapping (such as sh64) should also set UPF_IOREMAP.
1945 */
1946 static int __devinit sci_probe(struct platform_device *dev)
1947 {
1948 struct plat_sci_port *p = dev->dev.platform_data;
1949 struct sci_port *sp = &sci_ports[dev->id];
1950 int ret = -EINVAL;
1951
1952 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
1953 if (is_early_platform_device(dev)) {
1954 early_serial_console.index = dev->id;
1955 early_serial_console.data = &early_serial_port.port;
1956
1957 sci_init_single(NULL, &early_serial_port, dev->id, p);
1958
1959 serial_console_setup(&early_serial_console, early_serial_buf);
1960
1961 if (!strstr(early_serial_buf, "keep"))
1962 early_serial_console.flags |= CON_BOOT;
1963
1964 register_console(&early_serial_console);
1965 return 0;
1966 }
1967 #endif
1968
1969 platform_set_drvdata(dev, sp);
1970
1971 ret = sci_probe_single(dev, dev->id, p, &sci_ports[dev->id]);
1972 if (ret)
1973 goto err_unreg;
1974
1975 sp->freq_transition.notifier_call = sci_notifier;
1976
1977 ret = cpufreq_register_notifier(&sp->freq_transition,
1978 CPUFREQ_TRANSITION_NOTIFIER);
1979 if (unlikely(ret < 0))
1980 goto err_unreg;
1981
1982 #ifdef CONFIG_SH_STANDARD_BIOS
1983 sh_bios_gdb_detach();
1984 #endif
1985
1986 return 0;
1987
1988 err_unreg:
1989 sci_remove(dev);
1990 return ret;
1991 }
1992
1993 static int sci_suspend(struct device *dev)
1994 {
1995 struct sci_port *sport = dev_get_drvdata(dev);
1996
1997 if (sport)
1998 uart_suspend_port(&sci_uart_driver, &sport->port);
1999
2000 return 0;
2001 }
2002
2003 static int sci_resume(struct device *dev)
2004 {
2005 struct sci_port *sport = dev_get_drvdata(dev);
2006
2007 if (sport)
2008 uart_resume_port(&sci_uart_driver, &sport->port);
2009
2010 return 0;
2011 }
2012
2013 static const struct dev_pm_ops sci_dev_pm_ops = {
2014 .suspend = sci_suspend,
2015 .resume = sci_resume,
2016 };
2017
2018 static struct platform_driver sci_driver = {
2019 .probe = sci_probe,
2020 .remove = sci_remove,
2021 .driver = {
2022 .name = "sh-sci",
2023 .owner = THIS_MODULE,
2024 .pm = &sci_dev_pm_ops,
2025 },
2026 };
2027
2028 static int __init sci_init(void)
2029 {
2030 int ret;
2031
2032 printk(banner);
2033
2034 ret = uart_register_driver(&sci_uart_driver);
2035 if (likely(ret == 0)) {
2036 ret = platform_driver_register(&sci_driver);
2037 if (unlikely(ret))
2038 uart_unregister_driver(&sci_uart_driver);
2039 }
2040
2041 return ret;
2042 }
2043
2044 static void __exit sci_exit(void)
2045 {
2046 platform_driver_unregister(&sci_driver);
2047 uart_unregister_driver(&sci_uart_driver);
2048 }
2049
2050 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2051 early_platform_init_buffer("earlyprintk", &sci_driver,
2052 early_serial_buf, ARRAY_SIZE(early_serial_buf));
2053 #endif
2054 module_init(sci_init);
2055 module_exit(sci_exit);
2056
2057 MODULE_LICENSE("GPL");
2058 MODULE_ALIAS("platform:sh-sci");
Linux 2.6 libata-dev (mirror)