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spi: Drop owner assignment from spi_drivers
[linux-2.6/btrfs-unstable.git] / drivers / tty / serial / sh-sci.c
blob1b2f894bdc9e0e6ed15cf93feb405337b1d0d07b
1 /*
2 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
3 *
4 * Copyright (C) 2002 - 2011 Paul Mundt
5 * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
6 *
7 * based off of the old drivers/char/sh-sci.c by:
8 *
9 * Copyright (C) 1999, 2000 Niibe Yutaka
10 * Copyright (C) 2000 Sugioka Toshinobu
11 * Modified to support multiple serial ports. Stuart Menefy (May 2000).
12 * Modified to support SecureEdge. David McCullough (2002)
13 * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
14 * Removed SH7300 support (Jul 2007).
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License. See the file "COPYING" in the main directory of this archive
18 * for more details.
19 */
20 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
21 #define SUPPORT_SYSRQ
22 #endif
23
24 #undef DEBUG
25
26 #include <linux/clk.h>
27 #include <linux/console.h>
28 #include <linux/ctype.h>
29 #include <linux/cpufreq.h>
30 #include <linux/delay.h>
31 #include <linux/dmaengine.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/err.h>
34 #include <linux/errno.h>
35 #include <linux/init.h>
36 #include <linux/interrupt.h>
37 #include <linux/ioport.h>
38 #include <linux/major.h>
39 #include <linux/module.h>
40 #include <linux/mm.h>
41 #include <linux/notifier.h>
42 #include <linux/of.h>
43 #include <linux/platform_device.h>
44 #include <linux/pm_runtime.h>
45 #include <linux/scatterlist.h>
46 #include <linux/serial.h>
47 #include <linux/serial_sci.h>
48 #include <linux/sh_dma.h>
49 #include <linux/slab.h>
50 #include <linux/string.h>
51 #include <linux/sysrq.h>
52 #include <linux/timer.h>
53 #include <linux/tty.h>
54 #include <linux/tty_flip.h>
55
56 #ifdef CONFIG_SUPERH
57 #include <asm/sh_bios.h>
58 #endif
59
60 #include "sh-sci.h"
61
62 /* Offsets into the sci_port->irqs array */
63 enum {
64 SCIx_ERI_IRQ,
65 SCIx_RXI_IRQ,
66 SCIx_TXI_IRQ,
67 SCIx_BRI_IRQ,
68 SCIx_NR_IRQS,
69
70 SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */
71 };
72
73 #define SCIx_IRQ_IS_MUXED(port) \
74 ((port)->irqs[SCIx_ERI_IRQ] == \
75 (port)->irqs[SCIx_RXI_IRQ]) || \
76 ((port)->irqs[SCIx_ERI_IRQ] && \
77 ((port)->irqs[SCIx_RXI_IRQ] < 0))
78
79 struct sci_port {
80 struct uart_port port;
81
82 /* Platform configuration */
83 struct plat_sci_port *cfg;
84 unsigned int overrun_reg;
85 unsigned int overrun_mask;
86 unsigned int error_mask;
87 unsigned int sampling_rate;
88 resource_size_t reg_size;
89
90 /* Break timer */
91 struct timer_list break_timer;
92 int break_flag;
93
94 /* Interface clock */
95 struct clk *iclk;
96 /* Function clock */
97 struct clk *fclk;
98
99 int irqs[SCIx_NR_IRQS];
100 char *irqstr[SCIx_NR_IRQS];
101
102 struct dma_chan *chan_tx;
103 struct dma_chan *chan_rx;
104
105 #ifdef CONFIG_SERIAL_SH_SCI_DMA
106 struct dma_async_tx_descriptor *desc_tx;
107 struct dma_async_tx_descriptor *desc_rx[2];
108 dma_cookie_t cookie_tx;
109 dma_cookie_t cookie_rx[2];
110 dma_cookie_t active_rx;
111 struct scatterlist sg_tx;
112 unsigned int sg_len_tx;
113 struct scatterlist sg_rx[2];
114 size_t buf_len_rx;
115 struct sh_dmae_slave param_tx;
116 struct sh_dmae_slave param_rx;
117 struct work_struct work_tx;
118 struct work_struct work_rx;
119 struct timer_list rx_timer;
120 unsigned int rx_timeout;
121 #endif
122
123 struct notifier_block freq_transition;
124 };
125
126 /* Function prototypes */
127 static void sci_start_tx(struct uart_port *port);
128 static void sci_stop_tx(struct uart_port *port);
129 static void sci_start_rx(struct uart_port *port);
130
131 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
132
133 static struct sci_port sci_ports[SCI_NPORTS];
134 static struct uart_driver sci_uart_driver;
135
136 static inline struct sci_port *
137 to_sci_port(struct uart_port *uart)
138 {
139 return container_of(uart, struct sci_port, port);
140 }
141
142 struct plat_sci_reg {
143 u8 offset, size;
144 };
145
146 /* Helper for invalidating specific entries of an inherited map. */
147 #define sci_reg_invalid { .offset = 0, .size = 0 }
148
149 static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
150 [SCIx_PROBE_REGTYPE] = {
151 [0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
152 },
153
154 /*
155 * Common SCI definitions, dependent on the port's regshift
156 * value.
157 */
158 [SCIx_SCI_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] = sci_reg_invalid,
166 [SCFDR] = sci_reg_invalid,
167 [SCTFDR] = sci_reg_invalid,
168 [SCRFDR] = sci_reg_invalid,
169 [SCSPTR] = sci_reg_invalid,
170 [SCLSR] = sci_reg_invalid,
171 [HSSRR] = sci_reg_invalid,
172 [SCPCR] = sci_reg_invalid,
173 [SCPDR] = sci_reg_invalid,
174 },
175
176 /*
177 * Common definitions for legacy IrDA ports, dependent on
178 * regshift value.
179 */
180 [SCIx_IRDA_REGTYPE] = {
181 [SCSMR] = { 0x00, 8 },
182 [SCBRR] = { 0x01, 8 },
183 [SCSCR] = { 0x02, 8 },
184 [SCxTDR] = { 0x03, 8 },
185 [SCxSR] = { 0x04, 8 },
186 [SCxRDR] = { 0x05, 8 },
187 [SCFCR] = { 0x06, 8 },
188 [SCFDR] = { 0x07, 16 },
189 [SCTFDR] = sci_reg_invalid,
190 [SCRFDR] = sci_reg_invalid,
191 [SCSPTR] = sci_reg_invalid,
192 [SCLSR] = sci_reg_invalid,
193 [HSSRR] = sci_reg_invalid,
194 [SCPCR] = sci_reg_invalid,
195 [SCPDR] = sci_reg_invalid,
196 },
197
198 /*
199 * Common SCIFA definitions.
200 */
201 [SCIx_SCIFA_REGTYPE] = {
202 [SCSMR] = { 0x00, 16 },
203 [SCBRR] = { 0x04, 8 },
204 [SCSCR] = { 0x08, 16 },
205 [SCxTDR] = { 0x20, 8 },
206 [SCxSR] = { 0x14, 16 },
207 [SCxRDR] = { 0x24, 8 },
208 [SCFCR] = { 0x18, 16 },
209 [SCFDR] = { 0x1c, 16 },
210 [SCTFDR] = sci_reg_invalid,
211 [SCRFDR] = sci_reg_invalid,
212 [SCSPTR] = sci_reg_invalid,
213 [SCLSR] = sci_reg_invalid,
214 [HSSRR] = sci_reg_invalid,
215 [SCPCR] = { 0x30, 16 },
216 [SCPDR] = { 0x34, 16 },
217 },
218
219 /*
220 * Common SCIFB definitions.
221 */
222 [SCIx_SCIFB_REGTYPE] = {
223 [SCSMR] = { 0x00, 16 },
224 [SCBRR] = { 0x04, 8 },
225 [SCSCR] = { 0x08, 16 },
226 [SCxTDR] = { 0x40, 8 },
227 [SCxSR] = { 0x14, 16 },
228 [SCxRDR] = { 0x60, 8 },
229 [SCFCR] = { 0x18, 16 },
230 [SCFDR] = sci_reg_invalid,
231 [SCTFDR] = { 0x38, 16 },
232 [SCRFDR] = { 0x3c, 16 },
233 [SCSPTR] = sci_reg_invalid,
234 [SCLSR] = sci_reg_invalid,
235 [HSSRR] = sci_reg_invalid,
236 [SCPCR] = { 0x30, 16 },
237 [SCPDR] = { 0x34, 16 },
238 },
239
240 /*
241 * Common SH-2(A) SCIF definitions for ports with FIFO data
242 * count registers.
243 */
244 [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
245 [SCSMR] = { 0x00, 16 },
246 [SCBRR] = { 0x04, 8 },
247 [SCSCR] = { 0x08, 16 },
248 [SCxTDR] = { 0x0c, 8 },
249 [SCxSR] = { 0x10, 16 },
250 [SCxRDR] = { 0x14, 8 },
251 [SCFCR] = { 0x18, 16 },
252 [SCFDR] = { 0x1c, 16 },
253 [SCTFDR] = sci_reg_invalid,
254 [SCRFDR] = sci_reg_invalid,
255 [SCSPTR] = { 0x20, 16 },
256 [SCLSR] = { 0x24, 16 },
257 [HSSRR] = sci_reg_invalid,
258 [SCPCR] = sci_reg_invalid,
259 [SCPDR] = sci_reg_invalid,
260 },
261
262 /*
263 * Common SH-3 SCIF definitions.
264 */
265 [SCIx_SH3_SCIF_REGTYPE] = {
266 [SCSMR] = { 0x00, 8 },
267 [SCBRR] = { 0x02, 8 },
268 [SCSCR] = { 0x04, 8 },
269 [SCxTDR] = { 0x06, 8 },
270 [SCxSR] = { 0x08, 16 },
271 [SCxRDR] = { 0x0a, 8 },
272 [SCFCR] = { 0x0c, 8 },
273 [SCFDR] = { 0x0e, 16 },
274 [SCTFDR] = sci_reg_invalid,
275 [SCRFDR] = sci_reg_invalid,
276 [SCSPTR] = sci_reg_invalid,
277 [SCLSR] = sci_reg_invalid,
278 [HSSRR] = sci_reg_invalid,
279 [SCPCR] = sci_reg_invalid,
280 [SCPDR] = sci_reg_invalid,
281 },
282
283 /*
284 * Common SH-4(A) SCIF(B) definitions.
285 */
286 [SCIx_SH4_SCIF_REGTYPE] = {
287 [SCSMR] = { 0x00, 16 },
288 [SCBRR] = { 0x04, 8 },
289 [SCSCR] = { 0x08, 16 },
290 [SCxTDR] = { 0x0c, 8 },
291 [SCxSR] = { 0x10, 16 },
292 [SCxRDR] = { 0x14, 8 },
293 [SCFCR] = { 0x18, 16 },
294 [SCFDR] = { 0x1c, 16 },
295 [SCTFDR] = sci_reg_invalid,
296 [SCRFDR] = sci_reg_invalid,
297 [SCSPTR] = { 0x20, 16 },
298 [SCLSR] = { 0x24, 16 },
299 [HSSRR] = sci_reg_invalid,
300 [SCPCR] = sci_reg_invalid,
301 [SCPDR] = sci_reg_invalid,
302 },
303
304 /*
305 * Common HSCIF definitions.
306 */
307 [SCIx_HSCIF_REGTYPE] = {
308 [SCSMR] = { 0x00, 16 },
309 [SCBRR] = { 0x04, 8 },
310 [SCSCR] = { 0x08, 16 },
311 [SCxTDR] = { 0x0c, 8 },
312 [SCxSR] = { 0x10, 16 },
313 [SCxRDR] = { 0x14, 8 },
314 [SCFCR] = { 0x18, 16 },
315 [SCFDR] = { 0x1c, 16 },
316 [SCTFDR] = sci_reg_invalid,
317 [SCRFDR] = sci_reg_invalid,
318 [SCSPTR] = { 0x20, 16 },
319 [SCLSR] = { 0x24, 16 },
320 [HSSRR] = { 0x40, 16 },
321 [SCPCR] = sci_reg_invalid,
322 [SCPDR] = sci_reg_invalid,
323 },
324
325 /*
326 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
327 * register.
328 */
329 [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
330 [SCSMR] = { 0x00, 16 },
331 [SCBRR] = { 0x04, 8 },
332 [SCSCR] = { 0x08, 16 },
333 [SCxTDR] = { 0x0c, 8 },
334 [SCxSR] = { 0x10, 16 },
335 [SCxRDR] = { 0x14, 8 },
336 [SCFCR] = { 0x18, 16 },
337 [SCFDR] = { 0x1c, 16 },
338 [SCTFDR] = sci_reg_invalid,
339 [SCRFDR] = sci_reg_invalid,
340 [SCSPTR] = sci_reg_invalid,
341 [SCLSR] = { 0x24, 16 },
342 [HSSRR] = sci_reg_invalid,
343 [SCPCR] = sci_reg_invalid,
344 [SCPDR] = sci_reg_invalid,
345 },
346
347 /*
348 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
349 * count registers.
350 */
351 [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
352 [SCSMR] = { 0x00, 16 },
353 [SCBRR] = { 0x04, 8 },
354 [SCSCR] = { 0x08, 16 },
355 [SCxTDR] = { 0x0c, 8 },
356 [SCxSR] = { 0x10, 16 },
357 [SCxRDR] = { 0x14, 8 },
358 [SCFCR] = { 0x18, 16 },
359 [SCFDR] = { 0x1c, 16 },
360 [SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */
361 [SCRFDR] = { 0x20, 16 },
362 [SCSPTR] = { 0x24, 16 },
363 [SCLSR] = { 0x28, 16 },
364 [HSSRR] = sci_reg_invalid,
365 [SCPCR] = sci_reg_invalid,
366 [SCPDR] = sci_reg_invalid,
367 },
368
369 /*
370 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
371 * registers.
372 */
373 [SCIx_SH7705_SCIF_REGTYPE] = {
374 [SCSMR] = { 0x00, 16 },
375 [SCBRR] = { 0x04, 8 },
376 [SCSCR] = { 0x08, 16 },
377 [SCxTDR] = { 0x20, 8 },
378 [SCxSR] = { 0x14, 16 },
379 [SCxRDR] = { 0x24, 8 },
380 [SCFCR] = { 0x18, 16 },
381 [SCFDR] = { 0x1c, 16 },
382 [SCTFDR] = sci_reg_invalid,
383 [SCRFDR] = sci_reg_invalid,
384 [SCSPTR] = sci_reg_invalid,
385 [SCLSR] = sci_reg_invalid,
386 [HSSRR] = sci_reg_invalid,
387 [SCPCR] = sci_reg_invalid,
388 [SCPDR] = sci_reg_invalid,
389 },
390 };
391
392 #define sci_getreg(up, offset) (sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
393
394 /*
395 * The "offset" here is rather misleading, in that it refers to an enum
396 * value relative to the port mapping rather than the fixed offset
397 * itself, which needs to be manually retrieved from the platform's
398 * register map for the given port.
399 */
400 static unsigned int sci_serial_in(struct uart_port *p, int offset)
401 {
402 struct plat_sci_reg *reg = sci_getreg(p, offset);
403
404 if (reg->size == 8)
405 return ioread8(p->membase + (reg->offset << p->regshift));
406 else if (reg->size == 16)
407 return ioread16(p->membase + (reg->offset << p->regshift));
408 else
409 WARN(1, "Invalid register access\n");
410
411 return 0;
412 }
413
414 static void sci_serial_out(struct uart_port *p, int offset, int value)
415 {
416 struct plat_sci_reg *reg = sci_getreg(p, offset);
417
418 if (reg->size == 8)
419 iowrite8(value, p->membase + (reg->offset << p->regshift));
420 else if (reg->size == 16)
421 iowrite16(value, p->membase + (reg->offset << p->regshift));
422 else
423 WARN(1, "Invalid register access\n");
424 }
425
426 static int sci_probe_regmap(struct plat_sci_port *cfg)
427 {
428 switch (cfg->type) {
429 case PORT_SCI:
430 cfg->regtype = SCIx_SCI_REGTYPE;
431 break;
432 case PORT_IRDA:
433 cfg->regtype = SCIx_IRDA_REGTYPE;
434 break;
435 case PORT_SCIFA:
436 cfg->regtype = SCIx_SCIFA_REGTYPE;
437 break;
438 case PORT_SCIFB:
439 cfg->regtype = SCIx_SCIFB_REGTYPE;
440 break;
441 case PORT_SCIF:
442 /*
443 * The SH-4 is a bit of a misnomer here, although that's
444 * where this particular port layout originated. This
445 * configuration (or some slight variation thereof)
446 * remains the dominant model for all SCIFs.
447 */
448 cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
449 break;
450 case PORT_HSCIF:
451 cfg->regtype = SCIx_HSCIF_REGTYPE;
452 break;
453 default:
454 pr_err("Can't probe register map for given port\n");
455 return -EINVAL;
456 }
457
458 return 0;
459 }
460
461 static void sci_port_enable(struct sci_port *sci_port)
462 {
463 if (!sci_port->port.dev)
464 return;
465
466 pm_runtime_get_sync(sci_port->port.dev);
467
468 clk_prepare_enable(sci_port->iclk);
469 sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
470 clk_prepare_enable(sci_port->fclk);
471 }
472
473 static void sci_port_disable(struct sci_port *sci_port)
474 {
475 if (!sci_port->port.dev)
476 return;
477
478 /* Cancel the break timer to ensure that the timer handler will not try
479 * to access the hardware with clocks and power disabled. Reset the
480 * break flag to make the break debouncing state machine ready for the
481 * next break.
482 */
483 del_timer_sync(&sci_port->break_timer);
484 sci_port->break_flag = 0;
485
486 clk_disable_unprepare(sci_port->fclk);
487 clk_disable_unprepare(sci_port->iclk);
488
489 pm_runtime_put_sync(sci_port->port.dev);
490 }
491
492 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
493
494 #ifdef CONFIG_CONSOLE_POLL
495 static int sci_poll_get_char(struct uart_port *port)
496 {
497 unsigned short status;
498 int c;
499
500 do {
501 status = serial_port_in(port, SCxSR);
502 if (status & SCxSR_ERRORS(port)) {
503 serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
504 continue;
505 }
506 break;
507 } while (1);
508
509 if (!(status & SCxSR_RDxF(port)))
510 return NO_POLL_CHAR;
511
512 c = serial_port_in(port, SCxRDR);
513
514 /* Dummy read */
515 serial_port_in(port, SCxSR);
516 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
517
518 return c;
519 }
520 #endif
521
522 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
523 {
524 unsigned short status;
525
526 do {
527 status = serial_port_in(port, SCxSR);
528 } while (!(status & SCxSR_TDxE(port)));
529
530 serial_port_out(port, SCxTDR, c);
531 serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
532 }
533 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
534
535 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
536 {
537 struct sci_port *s = to_sci_port(port);
538 struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
539
540 /*
541 * Use port-specific handler if provided.
542 */
543 if (s->cfg->ops && s->cfg->ops->init_pins) {
544 s->cfg->ops->init_pins(port, cflag);
545 return;
546 }
547
548 /*
549 * For the generic path SCSPTR is necessary. Bail out if that's
550 * unavailable, too.
551 */
552 if (!reg->size)
553 return;
554
555 if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
556 ((!(cflag & CRTSCTS)))) {
557 unsigned short status;
558
559 status = serial_port_in(port, SCSPTR);
560 status &= ~SCSPTR_CTSIO;
561 status |= SCSPTR_RTSIO;
562 serial_port_out(port, SCSPTR, status); /* Set RTS = 1 */
563 }
564 }
565
566 static int sci_txfill(struct uart_port *port)
567 {
568 struct plat_sci_reg *reg;
569
570 reg = sci_getreg(port, SCTFDR);
571 if (reg->size)
572 return serial_port_in(port, SCTFDR) & ((port->fifosize << 1) - 1);
573
574 reg = sci_getreg(port, SCFDR);
575 if (reg->size)
576 return serial_port_in(port, SCFDR) >> 8;
577
578 return !(serial_port_in(port, SCxSR) & SCI_TDRE);
579 }
580
581 static int sci_txroom(struct uart_port *port)
582 {
583 return port->fifosize - sci_txfill(port);
584 }
585
586 static int sci_rxfill(struct uart_port *port)
587 {
588 struct plat_sci_reg *reg;
589
590 reg = sci_getreg(port, SCRFDR);
591 if (reg->size)
592 return serial_port_in(port, SCRFDR) & ((port->fifosize << 1) - 1);
593
594 reg = sci_getreg(port, SCFDR);
595 if (reg->size)
596 return serial_port_in(port, SCFDR) & ((port->fifosize << 1) - 1);
597
598 return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
599 }
600
601 /*
602 * SCI helper for checking the state of the muxed port/RXD pins.
603 */
604 static inline int sci_rxd_in(struct uart_port *port)
605 {
606 struct sci_port *s = to_sci_port(port);
607
608 if (s->cfg->port_reg <= 0)
609 return 1;
610
611 /* Cast for ARM damage */
612 return !!__raw_readb((void __iomem *)(uintptr_t)s->cfg->port_reg);
613 }
614
615 /* ********************************************************************** *
616 * the interrupt related routines *
617 * ********************************************************************** */
618
619 static void sci_transmit_chars(struct uart_port *port)
620 {
621 struct circ_buf *xmit = &port->state->xmit;
622 unsigned int stopped = uart_tx_stopped(port);
623 unsigned short status;
624 unsigned short ctrl;
625 int count;
626
627 status = serial_port_in(port, SCxSR);
628 if (!(status & SCxSR_TDxE(port))) {
629 ctrl = serial_port_in(port, SCSCR);
630 if (uart_circ_empty(xmit))
631 ctrl &= ~SCSCR_TIE;
632 else
633 ctrl |= SCSCR_TIE;
634 serial_port_out(port, SCSCR, ctrl);
635 return;
636 }
637
638 count = sci_txroom(port);
639
640 do {
641 unsigned char c;
642
643 if (port->x_char) {
644 c = port->x_char;
645 port->x_char = 0;
646 } else if (!uart_circ_empty(xmit) && !stopped) {
647 c = xmit->buf[xmit->tail];
648 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
649 } else {
650 break;
651 }
652
653 serial_port_out(port, SCxTDR, c);
654
655 port->icount.tx++;
656 } while (--count > 0);
657
658 serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
659
660 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
661 uart_write_wakeup(port);
662 if (uart_circ_empty(xmit)) {
663 sci_stop_tx(port);
664 } else {
665 ctrl = serial_port_in(port, SCSCR);
666
667 if (port->type != PORT_SCI) {
668 serial_port_in(port, SCxSR); /* Dummy read */
669 serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
670 }
671
672 ctrl |= SCSCR_TIE;
673 serial_port_out(port, SCSCR, ctrl);
674 }
675 }
676
677 /* On SH3, SCIF may read end-of-break as a space->mark char */
678 #define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); })
679
680 static void sci_receive_chars(struct uart_port *port)
681 {
682 struct sci_port *sci_port = to_sci_port(port);
683 struct tty_port *tport = &port->state->port;
684 int i, count, copied = 0;
685 unsigned short status;
686 unsigned char flag;
687
688 status = serial_port_in(port, SCxSR);
689 if (!(status & SCxSR_RDxF(port)))
690 return;
691
692 while (1) {
693 /* Don't copy more bytes than there is room for in the buffer */
694 count = tty_buffer_request_room(tport, sci_rxfill(port));
695
696 /* If for any reason we can't copy more data, we're done! */
697 if (count == 0)
698 break;
699
700 if (port->type == PORT_SCI) {
701 char c = serial_port_in(port, SCxRDR);
702 if (uart_handle_sysrq_char(port, c) ||
703 sci_port->break_flag)
704 count = 0;
705 else
706 tty_insert_flip_char(tport, c, TTY_NORMAL);
707 } else {
708 for (i = 0; i < count; i++) {
709 char c = serial_port_in(port, SCxRDR);
710
711 status = serial_port_in(port, SCxSR);
712 #if defined(CONFIG_CPU_SH3)
713 /* Skip "chars" during break */
714 if (sci_port->break_flag) {
715 if ((c == 0) &&
716 (status & SCxSR_FER(port))) {
717 count--; i--;
718 continue;
719 }
720
721 /* Nonzero => end-of-break */
722 dev_dbg(port->dev, "debounce<%02x>\n", c);
723 sci_port->break_flag = 0;
724
725 if (STEPFN(c)) {
726 count--; i--;
727 continue;
728 }
729 }
730 #endif /* CONFIG_CPU_SH3 */
731 if (uart_handle_sysrq_char(port, c)) {
732 count--; i--;
733 continue;
734 }
735
736 /* Store data and status */
737 if (status & SCxSR_FER(port)) {
738 flag = TTY_FRAME;
739 port->icount.frame++;
740 dev_notice(port->dev, "frame error\n");
741 } else if (status & SCxSR_PER(port)) {
742 flag = TTY_PARITY;
743 port->icount.parity++;
744 dev_notice(port->dev, "parity error\n");
745 } else
746 flag = TTY_NORMAL;
747
748 tty_insert_flip_char(tport, c, flag);
749 }
750 }
751
752 serial_port_in(port, SCxSR); /* dummy read */
753 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
754
755 copied += count;
756 port->icount.rx += count;
757 }
758
759 if (copied) {
760 /* Tell the rest of the system the news. New characters! */
761 tty_flip_buffer_push(tport);
762 } else {
763 serial_port_in(port, SCxSR); /* dummy read */
764 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
765 }
766 }
767
768 #define SCI_BREAK_JIFFIES (HZ/20)
769
770 /*
771 * The sci generates interrupts during the break,
772 * 1 per millisecond or so during the break period, for 9600 baud.
773 * So dont bother disabling interrupts.
774 * But dont want more than 1 break event.
775 * Use a kernel timer to periodically poll the rx line until
776 * the break is finished.
777 */
778 static inline void sci_schedule_break_timer(struct sci_port *port)
779 {
780 mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
781 }
782
783 /* Ensure that two consecutive samples find the break over. */
784 static void sci_break_timer(unsigned long data)
785 {
786 struct sci_port *port = (struct sci_port *)data;
787
788 if (sci_rxd_in(&port->port) == 0) {
789 port->break_flag = 1;
790 sci_schedule_break_timer(port);
791 } else if (port->break_flag == 1) {
792 /* break is over. */
793 port->break_flag = 2;
794 sci_schedule_break_timer(port);
795 } else
796 port->break_flag = 0;
797 }
798
799 static int sci_handle_errors(struct uart_port *port)
800 {
801 int copied = 0;
802 unsigned short status = serial_port_in(port, SCxSR);
803 struct tty_port *tport = &port->state->port;
804 struct sci_port *s = to_sci_port(port);
805
806 /* Handle overruns */
807 if (status & s->overrun_mask) {
808 port->icount.overrun++;
809
810 /* overrun error */
811 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
812 copied++;
813
814 dev_notice(port->dev, "overrun error\n");
815 }
816
817 if (status & SCxSR_FER(port)) {
818 if (sci_rxd_in(port) == 0) {
819 /* Notify of BREAK */
820 struct sci_port *sci_port = to_sci_port(port);
821
822 if (!sci_port->break_flag) {
823 port->icount.brk++;
824
825 sci_port->break_flag = 1;
826 sci_schedule_break_timer(sci_port);
827
828 /* Do sysrq handling. */
829 if (uart_handle_break(port))
830 return 0;
831
832 dev_dbg(port->dev, "BREAK detected\n");
833
834 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
835 copied++;
836 }
837
838 } else {
839 /* frame error */
840 port->icount.frame++;
841
842 if (tty_insert_flip_char(tport, 0, TTY_FRAME))
843 copied++;
844
845 dev_notice(port->dev, "frame error\n");
846 }
847 }
848
849 if (status & SCxSR_PER(port)) {
850 /* parity error */
851 port->icount.parity++;
852
853 if (tty_insert_flip_char(tport, 0, TTY_PARITY))
854 copied++;
855
856 dev_notice(port->dev, "parity error\n");
857 }
858
859 if (copied)
860 tty_flip_buffer_push(tport);
861
862 return copied;
863 }
864
865 static int sci_handle_fifo_overrun(struct uart_port *port)
866 {
867 struct tty_port *tport = &port->state->port;
868 struct sci_port *s = to_sci_port(port);
869 struct plat_sci_reg *reg;
870 int copied = 0;
871 u16 status;
872
873 reg = sci_getreg(port, s->overrun_reg);
874 if (!reg->size)
875 return 0;
876
877 status = serial_port_in(port, s->overrun_reg);
878 if (status & s->overrun_mask) {
879 status &= ~s->overrun_mask;
880 serial_port_out(port, s->overrun_reg, status);
881
882 port->icount.overrun++;
883
884 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
885 tty_flip_buffer_push(tport);
886
887 dev_dbg(port->dev, "overrun error\n");
888 copied++;
889 }
890
891 return copied;
892 }
893
894 static int sci_handle_breaks(struct uart_port *port)
895 {
896 int copied = 0;
897 unsigned short status = serial_port_in(port, SCxSR);
898 struct tty_port *tport = &port->state->port;
899 struct sci_port *s = to_sci_port(port);
900
901 if (uart_handle_break(port))
902 return 0;
903
904 if (!s->break_flag && status & SCxSR_BRK(port)) {
905 #if defined(CONFIG_CPU_SH3)
906 /* Debounce break */
907 s->break_flag = 1;
908 #endif
909
910 port->icount.brk++;
911
912 /* Notify of BREAK */
913 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
914 copied++;
915
916 dev_dbg(port->dev, "BREAK detected\n");
917 }
918
919 if (copied)
920 tty_flip_buffer_push(tport);
921
922 copied += sci_handle_fifo_overrun(port);
923
924 return copied;
925 }
926
927 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
928 {
929 #ifdef CONFIG_SERIAL_SH_SCI_DMA
930 struct uart_port *port = ptr;
931 struct sci_port *s = to_sci_port(port);
932
933 if (s->chan_rx) {
934 u16 scr = serial_port_in(port, SCSCR);
935 u16 ssr = serial_port_in(port, SCxSR);
936
937 /* Disable future Rx interrupts */
938 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
939 disable_irq_nosync(irq);
940 scr |= SCSCR_RDRQE;
941 } else {
942 scr &= ~SCSCR_RIE;
943 }
944 serial_port_out(port, SCSCR, scr);
945 /* Clear current interrupt */
946 serial_port_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
947 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
948 jiffies, s->rx_timeout);
949 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
950
951 return IRQ_HANDLED;
952 }
953 #endif
954
955 /* I think sci_receive_chars has to be called irrespective
956 * of whether the I_IXOFF is set, otherwise, how is the interrupt
957 * to be disabled?
958 */
959 sci_receive_chars(ptr);
960
961 return IRQ_HANDLED;
962 }
963
964 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
965 {
966 struct uart_port *port = ptr;
967 unsigned long flags;
968
969 spin_lock_irqsave(&port->lock, flags);
970 sci_transmit_chars(port);
971 spin_unlock_irqrestore(&port->lock, flags);
972
973 return IRQ_HANDLED;
974 }
975
976 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
977 {
978 struct uart_port *port = ptr;
979
980 /* Handle errors */
981 if (port->type == PORT_SCI) {
982 if (sci_handle_errors(port)) {
983 /* discard character in rx buffer */
984 serial_port_in(port, SCxSR);
985 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
986 }
987 } else {
988 sci_handle_fifo_overrun(port);
989 sci_rx_interrupt(irq, ptr);
990 }
991
992 serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
993
994 /* Kick the transmission */
995 sci_tx_interrupt(irq, ptr);
996
997 return IRQ_HANDLED;
998 }
999
1000 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1001 {
1002 struct uart_port *port = ptr;
1003
1004 /* Handle BREAKs */
1005 sci_handle_breaks(port);
1006 serial_port_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
1007
1008 return IRQ_HANDLED;
1009 }
1010
1011 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
1012 {
1013 /*
1014 * Not all ports (such as SCIFA) will support REIE. Rather than
1015 * special-casing the port type, we check the port initialization
1016 * IRQ enable mask to see whether the IRQ is desired at all. If
1017 * it's unset, it's logically inferred that there's no point in
1018 * testing for it.
1019 */
1020 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
1021 }
1022
1023 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1024 {
1025 unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1026 struct uart_port *port = ptr;
1027 struct sci_port *s = to_sci_port(port);
1028 irqreturn_t ret = IRQ_NONE;
1029
1030 ssr_status = serial_port_in(port, SCxSR);
1031 scr_status = serial_port_in(port, SCSCR);
1032 if (s->overrun_reg == SCxSR)
1033 orer_status = ssr_status;
1034 else {
1035 if (sci_getreg(port, s->overrun_reg)->size)
1036 orer_status = serial_port_in(port, s->overrun_reg);
1037 }
1038
1039 err_enabled = scr_status & port_rx_irq_mask(port);
1040
1041 /* Tx Interrupt */
1042 if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1043 !s->chan_tx)
1044 ret = sci_tx_interrupt(irq, ptr);
1045
1046 /*
1047 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1048 * DR flags
1049 */
1050 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1051 (scr_status & SCSCR_RIE)) {
1052 if (port->type == PORT_SCIF || port->type == PORT_HSCIF)
1053 sci_handle_fifo_overrun(port);
1054 ret = sci_rx_interrupt(irq, ptr);
1055 }
1056
1057 /* Error Interrupt */
1058 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1059 ret = sci_er_interrupt(irq, ptr);
1060
1061 /* Break Interrupt */
1062 if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1063 ret = sci_br_interrupt(irq, ptr);
1064
1065 /* Overrun Interrupt */
1066 if (orer_status & s->overrun_mask)
1067 sci_handle_fifo_overrun(port);
1068
1069 return ret;
1070 }
1071
1072 /*
1073 * Here we define a transition notifier so that we can update all of our
1074 * ports' baud rate when the peripheral clock changes.
1075 */
1076 static int sci_notifier(struct notifier_block *self,
1077 unsigned long phase, void *p)
1078 {
1079 struct sci_port *sci_port;
1080 unsigned long flags;
1081
1082 sci_port = container_of(self, struct sci_port, freq_transition);
1083
1084 if (phase == CPUFREQ_POSTCHANGE) {
1085 struct uart_port *port = &sci_port->port;
1086
1087 spin_lock_irqsave(&port->lock, flags);
1088 port->uartclk = clk_get_rate(sci_port->iclk);
1089 spin_unlock_irqrestore(&port->lock, flags);
1090 }
1091
1092 return NOTIFY_OK;
1093 }
1094
1095 static struct sci_irq_desc {
1096 const char *desc;
1097 irq_handler_t handler;
1098 } sci_irq_desc[] = {
1099 /*
1100 * Split out handlers, the default case.
1101 */
1102 [SCIx_ERI_IRQ] = {
1103 .desc = "rx err",
1104 .handler = sci_er_interrupt,
1105 },
1106
1107 [SCIx_RXI_IRQ] = {
1108 .desc = "rx full",
1109 .handler = sci_rx_interrupt,
1110 },
1111
1112 [SCIx_TXI_IRQ] = {
1113 .desc = "tx empty",
1114 .handler = sci_tx_interrupt,
1115 },
1116
1117 [SCIx_BRI_IRQ] = {
1118 .desc = "break",
1119 .handler = sci_br_interrupt,
1120 },
1121
1122 /*
1123 * Special muxed handler.
1124 */
1125 [SCIx_MUX_IRQ] = {
1126 .desc = "mux",
1127 .handler = sci_mpxed_interrupt,
1128 },
1129 };
1130
1131 static int sci_request_irq(struct sci_port *port)
1132 {
1133 struct uart_port *up = &port->port;
1134 int i, j, ret = 0;
1135
1136 for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1137 struct sci_irq_desc *desc;
1138 int irq;
1139
1140 if (SCIx_IRQ_IS_MUXED(port)) {
1141 i = SCIx_MUX_IRQ;
1142 irq = up->irq;
1143 } else {
1144 irq = port->irqs[i];
1145
1146 /*
1147 * Certain port types won't support all of the
1148 * available interrupt sources.
1149 */
1150 if (unlikely(irq < 0))
1151 continue;
1152 }
1153
1154 desc = sci_irq_desc + i;
1155 port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1156 dev_name(up->dev), desc->desc);
1157 if (!port->irqstr[j]) {
1158 dev_err(up->dev, "Failed to allocate %s IRQ string\n",
1159 desc->desc);
1160 goto out_nomem;
1161 }
1162
1163 ret = request_irq(irq, desc->handler, up->irqflags,
1164 port->irqstr[j], port);
1165 if (unlikely(ret)) {
1166 dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1167 goto out_noirq;
1168 }
1169 }
1170
1171 return 0;
1172
1173 out_noirq:
1174 while (--i >= 0)
1175 free_irq(port->irqs[i], port);
1176
1177 out_nomem:
1178 while (--j >= 0)
1179 kfree(port->irqstr[j]);
1180
1181 return ret;
1182 }
1183
1184 static void sci_free_irq(struct sci_port *port)
1185 {
1186 int i;
1187
1188 /*
1189 * Intentionally in reverse order so we iterate over the muxed
1190 * IRQ first.
1191 */
1192 for (i = 0; i < SCIx_NR_IRQS; i++) {
1193 int irq = port->irqs[i];
1194
1195 /*
1196 * Certain port types won't support all of the available
1197 * interrupt sources.
1198 */
1199 if (unlikely(irq < 0))
1200 continue;
1201
1202 free_irq(port->irqs[i], port);
1203 kfree(port->irqstr[i]);
1204
1205 if (SCIx_IRQ_IS_MUXED(port)) {
1206 /* If there's only one IRQ, we're done. */
1207 return;
1208 }
1209 }
1210 }
1211
1212 static unsigned int sci_tx_empty(struct uart_port *port)
1213 {
1214 unsigned short status = serial_port_in(port, SCxSR);
1215 unsigned short in_tx_fifo = sci_txfill(port);
1216
1217 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1218 }
1219
1220 /*
1221 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1222 * CTS/RTS is supported in hardware by at least one port and controlled
1223 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1224 * handled via the ->init_pins() op, which is a bit of a one-way street,
1225 * lacking any ability to defer pin control -- this will later be
1226 * converted over to the GPIO framework).
1227 *
1228 * Other modes (such as loopback) are supported generically on certain
1229 * port types, but not others. For these it's sufficient to test for the
1230 * existence of the support register and simply ignore the port type.
1231 */
1232 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1233 {
1234 if (mctrl & TIOCM_LOOP) {
1235 struct plat_sci_reg *reg;
1236
1237 /*
1238 * Standard loopback mode for SCFCR ports.
1239 */
1240 reg = sci_getreg(port, SCFCR);
1241 if (reg->size)
1242 serial_port_out(port, SCFCR,
1243 serial_port_in(port, SCFCR) |
1244 SCFCR_LOOP);
1245 }
1246 }
1247
1248 static unsigned int sci_get_mctrl(struct uart_port *port)
1249 {
1250 /*
1251 * CTS/RTS is handled in hardware when supported, while nothing
1252 * else is wired up. Keep it simple and simply assert DSR/CAR.
1253 */
1254 return TIOCM_DSR | TIOCM_CAR;
1255 }
1256
1257 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1258 static void sci_dma_tx_complete(void *arg)
1259 {
1260 struct sci_port *s = arg;
1261 struct uart_port *port = &s->port;
1262 struct circ_buf *xmit = &port->state->xmit;
1263 unsigned long flags;
1264
1265 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1266
1267 spin_lock_irqsave(&port->lock, flags);
1268
1269 xmit->tail += sg_dma_len(&s->sg_tx);
1270 xmit->tail &= UART_XMIT_SIZE - 1;
1271
1272 port->icount.tx += sg_dma_len(&s->sg_tx);
1273
1274 async_tx_ack(s->desc_tx);
1275 s->desc_tx = NULL;
1276
1277 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1278 uart_write_wakeup(port);
1279
1280 if (!uart_circ_empty(xmit)) {
1281 s->cookie_tx = 0;
1282 schedule_work(&s->work_tx);
1283 } else {
1284 s->cookie_tx = -EINVAL;
1285 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1286 u16 ctrl = serial_port_in(port, SCSCR);
1287 serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1288 }
1289 }
1290
1291 spin_unlock_irqrestore(&port->lock, flags);
1292 }
1293
1294 /* Locking: called with port lock held */
1295 static int sci_dma_rx_push(struct sci_port *s, size_t count)
1296 {
1297 struct uart_port *port = &s->port;
1298 struct tty_port *tport = &port->state->port;
1299 int i, active, room;
1300
1301 room = tty_buffer_request_room(tport, count);
1302
1303 if (s->active_rx == s->cookie_rx[0]) {
1304 active = 0;
1305 } else if (s->active_rx == s->cookie_rx[1]) {
1306 active = 1;
1307 } else {
1308 dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1309 return 0;
1310 }
1311
1312 if (room < count)
1313 dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n",
1314 count - room);
1315 if (!room)
1316 return room;
1317
1318 for (i = 0; i < room; i++)
1319 tty_insert_flip_char(tport, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
1320 TTY_NORMAL);
1321
1322 port->icount.rx += room;
1323
1324 return room;
1325 }
1326
1327 static void sci_dma_rx_complete(void *arg)
1328 {
1329 struct sci_port *s = arg;
1330 struct uart_port *port = &s->port;
1331 unsigned long flags;
1332 int count;
1333
1334 dev_dbg(port->dev, "%s(%d) active #%d\n",
1335 __func__, port->line, s->active_rx);
1336
1337 spin_lock_irqsave(&port->lock, flags);
1338
1339 count = sci_dma_rx_push(s, s->buf_len_rx);
1340
1341 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1342
1343 spin_unlock_irqrestore(&port->lock, flags);
1344
1345 if (count)
1346 tty_flip_buffer_push(&port->state->port);
1347
1348 schedule_work(&s->work_rx);
1349 }
1350
1351 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1352 {
1353 struct dma_chan *chan = s->chan_rx;
1354 struct uart_port *port = &s->port;
1355
1356 s->chan_rx = NULL;
1357 s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1358 dma_release_channel(chan);
1359 if (sg_dma_address(&s->sg_rx[0]))
1360 dma_free_coherent(port->dev, s->buf_len_rx * 2,
1361 sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
1362 if (enable_pio)
1363 sci_start_rx(port);
1364 }
1365
1366 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1367 {
1368 struct dma_chan *chan = s->chan_tx;
1369 struct uart_port *port = &s->port;
1370
1371 s->chan_tx = NULL;
1372 s->cookie_tx = -EINVAL;
1373 dma_release_channel(chan);
1374 if (enable_pio)
1375 sci_start_tx(port);
1376 }
1377
1378 static void sci_submit_rx(struct sci_port *s)
1379 {
1380 struct dma_chan *chan = s->chan_rx;
1381 int i;
1382
1383 for (i = 0; i < 2; i++) {
1384 struct scatterlist *sg = &s->sg_rx[i];
1385 struct dma_async_tx_descriptor *desc;
1386
1387 desc = dmaengine_prep_slave_sg(chan,
1388 sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1389
1390 if (desc) {
1391 s->desc_rx[i] = desc;
1392 desc->callback = sci_dma_rx_complete;
1393 desc->callback_param = s;
1394 s->cookie_rx[i] = desc->tx_submit(desc);
1395 }
1396
1397 if (!desc || s->cookie_rx[i] < 0) {
1398 if (i) {
1399 async_tx_ack(s->desc_rx[0]);
1400 s->cookie_rx[0] = -EINVAL;
1401 }
1402 if (desc) {
1403 async_tx_ack(desc);
1404 s->cookie_rx[i] = -EINVAL;
1405 }
1406 dev_warn(s->port.dev,
1407 "failed to re-start DMA, using PIO\n");
1408 sci_rx_dma_release(s, true);
1409 return;
1410 }
1411 dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n",
1412 __func__, s->cookie_rx[i], i);
1413 }
1414
1415 s->active_rx = s->cookie_rx[0];
1416
1417 dma_async_issue_pending(chan);
1418 }
1419
1420 static void work_fn_rx(struct work_struct *work)
1421 {
1422 struct sci_port *s = container_of(work, struct sci_port, work_rx);
1423 struct uart_port *port = &s->port;
1424 struct dma_async_tx_descriptor *desc;
1425 int new;
1426
1427 if (s->active_rx == s->cookie_rx[0]) {
1428 new = 0;
1429 } else if (s->active_rx == s->cookie_rx[1]) {
1430 new = 1;
1431 } else {
1432 dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1433 return;
1434 }
1435 desc = s->desc_rx[new];
1436
1437 if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
1438 DMA_COMPLETE) {
1439 /* Handle incomplete DMA receive */
1440 struct dma_chan *chan = s->chan_rx;
1441 struct shdma_desc *sh_desc = container_of(desc,
1442 struct shdma_desc, async_tx);
1443 unsigned long flags;
1444 int count;
1445
1446 dmaengine_terminate_all(chan);
1447 dev_dbg(port->dev, "Read %zu bytes with cookie %d\n",
1448 sh_desc->partial, sh_desc->cookie);
1449
1450 spin_lock_irqsave(&port->lock, flags);
1451 count = sci_dma_rx_push(s, sh_desc->partial);
1452 spin_unlock_irqrestore(&port->lock, flags);
1453
1454 if (count)
1455 tty_flip_buffer_push(&port->state->port);
1456
1457 sci_submit_rx(s);
1458
1459 return;
1460 }
1461
1462 s->cookie_rx[new] = desc->tx_submit(desc);
1463 if (s->cookie_rx[new] < 0) {
1464 dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1465 sci_rx_dma_release(s, true);
1466 return;
1467 }
1468
1469 s->active_rx = s->cookie_rx[!new];
1470
1471 dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n",
1472 __func__, s->cookie_rx[new], new, s->active_rx);
1473 }
1474
1475 static void work_fn_tx(struct work_struct *work)
1476 {
1477 struct sci_port *s = container_of(work, struct sci_port, work_tx);
1478 struct dma_async_tx_descriptor *desc;
1479 struct dma_chan *chan = s->chan_tx;
1480 struct uart_port *port = &s->port;
1481 struct circ_buf *xmit = &port->state->xmit;
1482 struct scatterlist *sg = &s->sg_tx;
1483
1484 /*
1485 * DMA is idle now.
1486 * Port xmit buffer is already mapped, and it is one page... Just adjust
1487 * offsets and lengths. Since it is a circular buffer, we have to
1488 * transmit till the end, and then the rest. Take the port lock to get a
1489 * consistent xmit buffer state.
1490 */
1491 spin_lock_irq(&port->lock);
1492 sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
1493 sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
1494 sg->offset;
1495 sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1496 CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1497 spin_unlock_irq(&port->lock);
1498
1499 BUG_ON(!sg_dma_len(sg));
1500
1501 desc = dmaengine_prep_slave_sg(chan,
1502 sg, s->sg_len_tx, DMA_MEM_TO_DEV,
1503 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1504 if (!desc) {
1505 /* switch to PIO */
1506 sci_tx_dma_release(s, true);
1507 return;
1508 }
1509
1510 dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
1511
1512 spin_lock_irq(&port->lock);
1513 s->desc_tx = desc;
1514 desc->callback = sci_dma_tx_complete;
1515 desc->callback_param = s;
1516 spin_unlock_irq(&port->lock);
1517 s->cookie_tx = desc->tx_submit(desc);
1518 if (s->cookie_tx < 0) {
1519 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1520 /* switch to PIO */
1521 sci_tx_dma_release(s, true);
1522 return;
1523 }
1524
1525 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1526 __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1527
1528 dma_async_issue_pending(chan);
1529 }
1530 #endif
1531
1532 static void sci_start_tx(struct uart_port *port)
1533 {
1534 struct sci_port *s = to_sci_port(port);
1535 unsigned short ctrl;
1536
1537 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1538 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1539 u16 new, scr = serial_port_in(port, SCSCR);
1540 if (s->chan_tx)
1541 new = scr | SCSCR_TDRQE;
1542 else
1543 new = scr & ~SCSCR_TDRQE;
1544 if (new != scr)
1545 serial_port_out(port, SCSCR, new);
1546 }
1547
1548 if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
1549 s->cookie_tx < 0) {
1550 s->cookie_tx = 0;
1551 schedule_work(&s->work_tx);
1552 }
1553 #endif
1554
1555 if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1556 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
1557 ctrl = serial_port_in(port, SCSCR);
1558 serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
1559 }
1560 }
1561
1562 static void sci_stop_tx(struct uart_port *port)
1563 {
1564 unsigned short ctrl;
1565
1566 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
1567 ctrl = serial_port_in(port, SCSCR);
1568
1569 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1570 ctrl &= ~SCSCR_TDRQE;
1571
1572 ctrl &= ~SCSCR_TIE;
1573
1574 serial_port_out(port, SCSCR, ctrl);
1575 }
1576
1577 static void sci_start_rx(struct uart_port *port)
1578 {
1579 unsigned short ctrl;
1580
1581 ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
1582
1583 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1584 ctrl &= ~SCSCR_RDRQE;
1585
1586 serial_port_out(port, SCSCR, ctrl);
1587 }
1588
1589 static void sci_stop_rx(struct uart_port *port)
1590 {
1591 unsigned short ctrl;
1592
1593 ctrl = serial_port_in(port, SCSCR);
1594
1595 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1596 ctrl &= ~SCSCR_RDRQE;
1597
1598 ctrl &= ~port_rx_irq_mask(port);
1599
1600 serial_port_out(port, SCSCR, ctrl);
1601 }
1602
1603 static void sci_break_ctl(struct uart_port *port, int break_state)
1604 {
1605 struct sci_port *s = to_sci_port(port);
1606 struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
1607 unsigned short scscr, scsptr;
1608
1609 /* check wheter the port has SCSPTR */
1610 if (!reg->size) {
1611 /*
1612 * Not supported by hardware. Most parts couple break and rx
1613 * interrupts together, with break detection always enabled.
1614 */
1615 return;
1616 }
1617
1618 scsptr = serial_port_in(port, SCSPTR);
1619 scscr = serial_port_in(port, SCSCR);
1620
1621 if (break_state == -1) {
1622 scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
1623 scscr &= ~SCSCR_TE;
1624 } else {
1625 scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
1626 scscr |= SCSCR_TE;
1627 }
1628
1629 serial_port_out(port, SCSPTR, scsptr);
1630 serial_port_out(port, SCSCR, scscr);
1631 }
1632
1633 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1634 static bool filter(struct dma_chan *chan, void *slave)
1635 {
1636 struct sh_dmae_slave *param = slave;
1637
1638 dev_dbg(chan->device->dev, "%s: slave ID %d\n",
1639 __func__, param->shdma_slave.slave_id);
1640
1641 chan->private = &param->shdma_slave;
1642 return true;
1643 }
1644
1645 static void rx_timer_fn(unsigned long arg)
1646 {
1647 struct sci_port *s = (struct sci_port *)arg;
1648 struct uart_port *port = &s->port;
1649 u16 scr = serial_port_in(port, SCSCR);
1650
1651 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1652 scr &= ~SCSCR_RDRQE;
1653 enable_irq(s->irqs[SCIx_RXI_IRQ]);
1654 }
1655 serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1656 dev_dbg(port->dev, "DMA Rx timed out\n");
1657 schedule_work(&s->work_rx);
1658 }
1659
1660 static void sci_request_dma(struct uart_port *port)
1661 {
1662 struct sci_port *s = to_sci_port(port);
1663 struct sh_dmae_slave *param;
1664 struct dma_chan *chan;
1665 dma_cap_mask_t mask;
1666 int nent;
1667
1668 dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1669
1670 if (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0)
1671 return;
1672
1673 dma_cap_zero(mask);
1674 dma_cap_set(DMA_SLAVE, mask);
1675
1676 param = &s->param_tx;
1677
1678 /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
1679 param->shdma_slave.slave_id = s->cfg->dma_slave_tx;
1680
1681 s->cookie_tx = -EINVAL;
1682 chan = dma_request_channel(mask, filter, param);
1683 dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1684 if (chan) {
1685 s->chan_tx = chan;
1686 sg_init_table(&s->sg_tx, 1);
1687 /* UART circular tx buffer is an aligned page. */
1688 BUG_ON((uintptr_t)port->state->xmit.buf & ~PAGE_MASK);
1689 sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
1690 UART_XMIT_SIZE,
1691 (uintptr_t)port->state->xmit.buf & ~PAGE_MASK);
1692 nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
1693 if (!nent)
1694 sci_tx_dma_release(s, false);
1695 else
1696 dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n",
1697 __func__,
1698 sg_dma_len(&s->sg_tx), port->state->xmit.buf,
1699 &sg_dma_address(&s->sg_tx));
1700
1701 s->sg_len_tx = nent;
1702
1703 INIT_WORK(&s->work_tx, work_fn_tx);
1704 }
1705
1706 param = &s->param_rx;
1707
1708 /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
1709 param->shdma_slave.slave_id = s->cfg->dma_slave_rx;
1710
1711 chan = dma_request_channel(mask, filter, param);
1712 dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1713 if (chan) {
1714 dma_addr_t dma[2];
1715 void *buf[2];
1716 int i;
1717
1718 s->chan_rx = chan;
1719
1720 s->buf_len_rx = 2 * max(16, (int)port->fifosize);
1721 buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
1722 &dma[0], GFP_KERNEL);
1723
1724 if (!buf[0]) {
1725 dev_warn(port->dev,
1726 "failed to allocate dma buffer, using PIO\n");
1727 sci_rx_dma_release(s, true);
1728 return;
1729 }
1730
1731 buf[1] = buf[0] + s->buf_len_rx;
1732 dma[1] = dma[0] + s->buf_len_rx;
1733
1734 for (i = 0; i < 2; i++) {
1735 struct scatterlist *sg = &s->sg_rx[i];
1736
1737 sg_init_table(sg, 1);
1738 sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
1739 (uintptr_t)buf[i] & ~PAGE_MASK);
1740 sg_dma_address(sg) = dma[i];
1741 }
1742
1743 INIT_WORK(&s->work_rx, work_fn_rx);
1744 setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1745
1746 sci_submit_rx(s);
1747 }
1748 }
1749
1750 static void sci_free_dma(struct uart_port *port)
1751 {
1752 struct sci_port *s = to_sci_port(port);
1753
1754 if (s->chan_tx)
1755 sci_tx_dma_release(s, false);
1756 if (s->chan_rx)
1757 sci_rx_dma_release(s, false);
1758 }
1759 #else
1760 static inline void sci_request_dma(struct uart_port *port)
1761 {
1762 }
1763
1764 static inline void sci_free_dma(struct uart_port *port)
1765 {
1766 }
1767 #endif
1768
1769 static int sci_startup(struct uart_port *port)
1770 {
1771 struct sci_port *s = to_sci_port(port);
1772 unsigned long flags;
1773 int ret;
1774
1775 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1776
1777 ret = sci_request_irq(s);
1778 if (unlikely(ret < 0))
1779 return ret;
1780
1781 sci_request_dma(port);
1782
1783 spin_lock_irqsave(&port->lock, flags);
1784 sci_start_tx(port);
1785 sci_start_rx(port);
1786 spin_unlock_irqrestore(&port->lock, flags);
1787
1788 return 0;
1789 }
1790
1791 static void sci_shutdown(struct uart_port *port)
1792 {
1793 struct sci_port *s = to_sci_port(port);
1794 unsigned long flags;
1795
1796 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1797
1798 spin_lock_irqsave(&port->lock, flags);
1799 sci_stop_rx(port);
1800 sci_stop_tx(port);
1801 spin_unlock_irqrestore(&port->lock, flags);
1802
1803 sci_free_dma(port);
1804 sci_free_irq(s);
1805 }
1806
1807 static unsigned int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
1808 unsigned long freq)
1809 {
1810 if (s->sampling_rate)
1811 return DIV_ROUND_CLOSEST(freq, s->sampling_rate * bps) - 1;
1812
1813 /* Warn, but use a safe default */
1814 WARN_ON(1);
1815
1816 return ((freq + 16 * bps) / (32 * bps) - 1);
1817 }
1818
1819 /* calculate frame length from SMR */
1820 static int sci_baud_calc_frame_len(unsigned int smr_val)
1821 {
1822 int len = 10;
1823
1824 if (smr_val & SCSMR_CHR)
1825 len--;
1826 if (smr_val & SCSMR_PE)
1827 len++;
1828 if (smr_val & SCSMR_STOP)
1829 len++;
1830
1831 return len;
1832 }
1833
1834
1835 /* calculate sample rate, BRR, and clock select for HSCIF */
1836 static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq,
1837 int *brr, unsigned int *srr,
1838 unsigned int *cks, int frame_len)
1839 {
1840 int sr, c, br, err, recv_margin;
1841 int min_err = 1000; /* 100% */
1842 int recv_max_margin = 0;
1843
1844 /* Find the combination of sample rate and clock select with the
1845 smallest deviation from the desired baud rate. */
1846 for (sr = 8; sr <= 32; sr++) {
1847 for (c = 0; c <= 3; c++) {
1848 /* integerized formulas from HSCIF documentation */
1849 br = DIV_ROUND_CLOSEST(freq, (sr *
1850 (1 << (2 * c + 1)) * bps)) - 1;
1851 br = clamp(br, 0, 255);
1852 err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr *
1853 (1 << (2 * c + 1)) / 1000)) -
1854 1000;
1855 /* Calc recv margin
1856 * M: Receive margin (%)
1857 * N: Ratio of bit rate to clock (N = sampling rate)
1858 * D: Clock duty (D = 0 to 1.0)
1859 * L: Frame length (L = 9 to 12)
1860 * F: Absolute value of clock frequency deviation
1861 *
1862 * M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
1863 * (|D - 0.5| / N * (1 + F))|
1864 * NOTE: Usually, treat D for 0.5, F is 0 by this
1865 * calculation.
1866 */
1867 recv_margin = abs((500 -
1868 DIV_ROUND_CLOSEST(1000, sr << 1)) / 10);
1869 if (abs(min_err) > abs(err)) {
1870 min_err = err;
1871 recv_max_margin = recv_margin;
1872 } else if ((min_err == err) &&
1873 (recv_margin > recv_max_margin))
1874 recv_max_margin = recv_margin;
1875 else
1876 continue;
1877
1878 *brr = br;
1879 *srr = sr - 1;
1880 *cks = c;
1881 }
1882 }
1883
1884 if (min_err == 1000) {
1885 WARN_ON(1);
1886 /* use defaults */
1887 *brr = 255;
1888 *srr = 15;
1889 *cks = 0;
1890 }
1891 }
1892
1893 static void sci_reset(struct uart_port *port)
1894 {
1895 struct plat_sci_reg *reg;
1896 unsigned int status;
1897
1898 do {
1899 status = serial_port_in(port, SCxSR);
1900 } while (!(status & SCxSR_TEND(port)));
1901
1902 serial_port_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */
1903
1904 reg = sci_getreg(port, SCFCR);
1905 if (reg->size)
1906 serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
1907 }
1908
1909 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
1910 struct ktermios *old)
1911 {
1912 struct sci_port *s = to_sci_port(port);
1913 struct plat_sci_reg *reg;
1914 unsigned int baud, smr_val = 0, max_baud, cks = 0;
1915 int t = -1;
1916 unsigned int srr = 15;
1917
1918 if ((termios->c_cflag & CSIZE) == CS7)
1919 smr_val |= SCSMR_CHR;
1920 if (termios->c_cflag & PARENB)
1921 smr_val |= SCSMR_PE;
1922 if (termios->c_cflag & PARODD)
1923 smr_val |= SCSMR_PE | SCSMR_ODD;
1924 if (termios->c_cflag & CSTOPB)
1925 smr_val |= SCSMR_STOP;
1926
1927 /*
1928 * earlyprintk comes here early on with port->uartclk set to zero.
1929 * the clock framework is not up and running at this point so here
1930 * we assume that 115200 is the maximum baud rate. please note that
1931 * the baud rate is not programmed during earlyprintk - it is assumed
1932 * that the previous boot loader has enabled required clocks and
1933 * setup the baud rate generator hardware for us already.
1934 */
1935 max_baud = port->uartclk ? port->uartclk / 16 : 115200;
1936
1937 baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
1938 if (likely(baud && port->uartclk)) {
1939 if (s->cfg->type == PORT_HSCIF) {
1940 int frame_len = sci_baud_calc_frame_len(smr_val);
1941 sci_baud_calc_hscif(baud, port->uartclk, &t, &srr,
1942 &cks, frame_len);
1943 } else {
1944 t = sci_scbrr_calc(s, baud, port->uartclk);
1945 for (cks = 0; t >= 256 && cks <= 3; cks++)
1946 t >>= 2;
1947 }
1948 }
1949
1950 sci_port_enable(s);
1951
1952 sci_reset(port);
1953
1954 smr_val |= serial_port_in(port, SCSMR) & 3;
1955
1956 uart_update_timeout(port, termios->c_cflag, baud);
1957
1958 dev_dbg(port->dev, "%s: SMR %x, cks %x, t %x, SCSCR %x\n",
1959 __func__, smr_val, cks, t, s->cfg->scscr);
1960
1961 if (t >= 0) {
1962 serial_port_out(port, SCSMR, (smr_val & ~SCSMR_CKS) | cks);
1963 serial_port_out(port, SCBRR, t);
1964 reg = sci_getreg(port, HSSRR);
1965 if (reg->size)
1966 serial_port_out(port, HSSRR, srr | HSCIF_SRE);
1967 udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
1968 } else
1969 serial_port_out(port, SCSMR, smr_val);
1970
1971 sci_init_pins(port, termios->c_cflag);
1972
1973 reg = sci_getreg(port, SCFCR);
1974 if (reg->size) {
1975 unsigned short ctrl = serial_port_in(port, SCFCR);
1976
1977 if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) {
1978 if (termios->c_cflag & CRTSCTS)
1979 ctrl |= SCFCR_MCE;
1980 else
1981 ctrl &= ~SCFCR_MCE;
1982 }
1983
1984 /*
1985 * As we've done a sci_reset() above, ensure we don't
1986 * interfere with the FIFOs while toggling MCE. As the
1987 * reset values could still be set, simply mask them out.
1988 */
1989 ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
1990
1991 serial_port_out(port, SCFCR, ctrl);
1992 }
1993
1994 serial_port_out(port, SCSCR, s->cfg->scscr);
1995
1996 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1997 /*
1998 * Calculate delay for 2 DMA buffers (4 FIFO).
1999 * See drivers/serial/serial_core.c::uart_update_timeout(). With 10
2000 * bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
2001 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
2002 * Then below we calculate 5 jiffies (20ms) for 2 DMA buffers (4 FIFO
2003 * sizes), but when performing a faster transfer, value obtained by
2004 * this formula is may not enough. Therefore, if value is smaller than
2005 * 20msec, this sets 20msec as timeout of DMA.
2006 */
2007 if (s->chan_rx) {
2008 unsigned int bits;
2009
2010 /* byte size and parity */
2011 switch (termios->c_cflag & CSIZE) {
2012 case CS5:
2013 bits = 7;
2014 break;
2015 case CS6:
2016 bits = 8;
2017 break;
2018 case CS7:
2019 bits = 9;
2020 break;
2021 default:
2022 bits = 10;
2023 break;
2024 }
2025
2026 if (termios->c_cflag & CSTOPB)
2027 bits++;
2028 if (termios->c_cflag & PARENB)
2029 bits++;
2030 s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
2031 (baud / 10), 10);
2032 dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n",
2033 s->rx_timeout * 1000 / HZ, port->timeout);
2034 if (s->rx_timeout < msecs_to_jiffies(20))
2035 s->rx_timeout = msecs_to_jiffies(20);
2036 }
2037 #endif
2038
2039 if ((termios->c_cflag & CREAD) != 0)
2040 sci_start_rx(port);
2041
2042 sci_port_disable(s);
2043 }
2044
2045 static void sci_pm(struct uart_port *port, unsigned int state,
2046 unsigned int oldstate)
2047 {
2048 struct sci_port *sci_port = to_sci_port(port);
2049
2050 switch (state) {
2051 case UART_PM_STATE_OFF:
2052 sci_port_disable(sci_port);
2053 break;
2054 default:
2055 sci_port_enable(sci_port);
2056 break;
2057 }
2058 }
2059
2060 static const char *sci_type(struct uart_port *port)
2061 {
2062 switch (port->type) {
2063 case PORT_IRDA:
2064 return "irda";
2065 case PORT_SCI:
2066 return "sci";
2067 case PORT_SCIF:
2068 return "scif";
2069 case PORT_SCIFA:
2070 return "scifa";
2071 case PORT_SCIFB:
2072 return "scifb";
2073 case PORT_HSCIF:
2074 return "hscif";
2075 }
2076
2077 return NULL;
2078 }
2079
2080 static int sci_remap_port(struct uart_port *port)
2081 {
2082 struct sci_port *sport = to_sci_port(port);
2083
2084 /*
2085 * Nothing to do if there's already an established membase.
2086 */
2087 if (port->membase)
2088 return 0;
2089
2090 if (port->flags & UPF_IOREMAP) {
2091 port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2092 if (unlikely(!port->membase)) {
2093 dev_err(port->dev, "can't remap port#%d\n", port->line);
2094 return -ENXIO;
2095 }
2096 } else {
2097 /*
2098 * For the simple (and majority of) cases where we don't
2099 * need to do any remapping, just cast the cookie
2100 * directly.
2101 */
2102 port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2103 }
2104
2105 return 0;
2106 }
2107
2108 static void sci_release_port(struct uart_port *port)
2109 {
2110 struct sci_port *sport = to_sci_port(port);
2111
2112 if (port->flags & UPF_IOREMAP) {
2113 iounmap(port->membase);
2114 port->membase = NULL;
2115 }
2116
2117 release_mem_region(port->mapbase, sport->reg_size);
2118 }
2119
2120 static int sci_request_port(struct uart_port *port)
2121 {
2122 struct resource *res;
2123 struct sci_port *sport = to_sci_port(port);
2124 int ret;
2125
2126 res = request_mem_region(port->mapbase, sport->reg_size,
2127 dev_name(port->dev));
2128 if (unlikely(res == NULL)) {
2129 dev_err(port->dev, "request_mem_region failed.");
2130 return -EBUSY;
2131 }
2132
2133 ret = sci_remap_port(port);
2134 if (unlikely(ret != 0)) {
2135 release_resource(res);
2136 return ret;
2137 }
2138
2139 return 0;
2140 }
2141
2142 static void sci_config_port(struct uart_port *port, int flags)
2143 {
2144 if (flags & UART_CONFIG_TYPE) {
2145 struct sci_port *sport = to_sci_port(port);
2146
2147 port->type = sport->cfg->type;
2148 sci_request_port(port);
2149 }
2150 }
2151
2152 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2153 {
2154 if (ser->baud_base < 2400)
2155 /* No paper tape reader for Mitch.. */
2156 return -EINVAL;
2157
2158 return 0;
2159 }
2160
2161 static struct uart_ops sci_uart_ops = {
2162 .tx_empty = sci_tx_empty,
2163 .set_mctrl = sci_set_mctrl,
2164 .get_mctrl = sci_get_mctrl,
2165 .start_tx = sci_start_tx,
2166 .stop_tx = sci_stop_tx,
2167 .stop_rx = sci_stop_rx,
2168 .break_ctl = sci_break_ctl,
2169 .startup = sci_startup,
2170 .shutdown = sci_shutdown,
2171 .set_termios = sci_set_termios,
2172 .pm = sci_pm,
2173 .type = sci_type,
2174 .release_port = sci_release_port,
2175 .request_port = sci_request_port,
2176 .config_port = sci_config_port,
2177 .verify_port = sci_verify_port,
2178 #ifdef CONFIG_CONSOLE_POLL
2179 .poll_get_char = sci_poll_get_char,
2180 .poll_put_char = sci_poll_put_char,
2181 #endif
2182 };
2183
2184 static int sci_init_single(struct platform_device *dev,
2185 struct sci_port *sci_port, unsigned int index,
2186 struct plat_sci_port *p, bool early)
2187 {
2188 struct uart_port *port = &sci_port->port;
2189 const struct resource *res;
2190 unsigned int sampling_rate;
2191 unsigned int i;
2192 int ret;
2193
2194 sci_port->cfg = p;
2195
2196 port->ops = &sci_uart_ops;
2197 port->iotype = UPIO_MEM;
2198 port->line = index;
2199
2200 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2201 if (res == NULL)
2202 return -ENOMEM;
2203
2204 port->mapbase = res->start;
2205 sci_port->reg_size = resource_size(res);
2206
2207 for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2208 sci_port->irqs[i] = platform_get_irq(dev, i);
2209
2210 /* The SCI generates several interrupts. They can be muxed together or
2211 * connected to different interrupt lines. In the muxed case only one
2212 * interrupt resource is specified. In the non-muxed case three or four
2213 * interrupt resources are specified, as the BRI interrupt is optional.
2214 */
2215 if (sci_port->irqs[0] < 0)
2216 return -ENXIO;
2217
2218 if (sci_port->irqs[1] < 0) {
2219 sci_port->irqs[1] = sci_port->irqs[0];
2220 sci_port->irqs[2] = sci_port->irqs[0];
2221 sci_port->irqs[3] = sci_port->irqs[0];
2222 }
2223
2224 if (p->regtype == SCIx_PROBE_REGTYPE) {
2225 ret = sci_probe_regmap(p);
2226 if (unlikely(ret))
2227 return ret;
2228 }
2229
2230 switch (p->type) {
2231 case PORT_SCIFB:
2232 port->fifosize = 256;
2233 sci_port->overrun_reg = SCxSR;
2234 sci_port->overrun_mask = SCIFA_ORER;
2235 sampling_rate = 16;
2236 break;
2237 case PORT_HSCIF:
2238 port->fifosize = 128;
2239 sampling_rate = 0;
2240 sci_port->overrun_reg = SCLSR;
2241 sci_port->overrun_mask = SCLSR_ORER;
2242 break;
2243 case PORT_SCIFA:
2244 port->fifosize = 64;
2245 sci_port->overrun_reg = SCxSR;
2246 sci_port->overrun_mask = SCIFA_ORER;
2247 sampling_rate = 16;
2248 break;
2249 case PORT_SCIF:
2250 port->fifosize = 16;
2251 if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) {
2252 sci_port->overrun_reg = SCxSR;
2253 sci_port->overrun_mask = SCIFA_ORER;
2254 sampling_rate = 16;
2255 } else {
2256 sci_port->overrun_reg = SCLSR;
2257 sci_port->overrun_mask = SCLSR_ORER;
2258 sampling_rate = 32;
2259 }
2260 break;
2261 default:
2262 port->fifosize = 1;
2263 sci_port->overrun_reg = SCxSR;
2264 sci_port->overrun_mask = SCI_ORER;
2265 sampling_rate = 32;
2266 break;
2267 }
2268
2269 /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2270 * match the SoC datasheet, this should be investigated. Let platform
2271 * data override the sampling rate for now.
2272 */
2273 sci_port->sampling_rate = p->sampling_rate ? p->sampling_rate
2274 : sampling_rate;
2275
2276 if (!early) {
2277 sci_port->iclk = clk_get(&dev->dev, "sci_ick");
2278 if (IS_ERR(sci_port->iclk)) {
2279 sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
2280 if (IS_ERR(sci_port->iclk)) {
2281 dev_err(&dev->dev, "can't get iclk\n");
2282 return PTR_ERR(sci_port->iclk);
2283 }
2284 }
2285
2286 /*
2287 * The function clock is optional, ignore it if we can't
2288 * find it.
2289 */
2290 sci_port->fclk = clk_get(&dev->dev, "sci_fck");
2291 if (IS_ERR(sci_port->fclk))
2292 sci_port->fclk = NULL;
2293
2294 port->dev = &dev->dev;
2295
2296 pm_runtime_enable(&dev->dev);
2297 }
2298
2299 sci_port->break_timer.data = (unsigned long)sci_port;
2300 sci_port->break_timer.function = sci_break_timer;
2301 init_timer(&sci_port->break_timer);
2302
2303 /*
2304 * Establish some sensible defaults for the error detection.
2305 */
2306 sci_port->error_mask = (p->type == PORT_SCI) ?
2307 SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK;
2308
2309 /*
2310 * Make the error mask inclusive of overrun detection, if
2311 * supported.
2312 */
2313 if (sci_port->overrun_reg == SCxSR)
2314 sci_port->error_mask |= sci_port->overrun_mask;
2315
2316 port->type = p->type;
2317 port->flags = UPF_FIXED_PORT | p->flags;
2318 port->regshift = p->regshift;
2319
2320 /*
2321 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2322 * for the multi-IRQ ports, which is where we are primarily
2323 * concerned with the shutdown path synchronization.
2324 *
2325 * For the muxed case there's nothing more to do.
2326 */
2327 port->irq = sci_port->irqs[SCIx_RXI_IRQ];
2328 port->irqflags = 0;
2329
2330 port->serial_in = sci_serial_in;
2331 port->serial_out = sci_serial_out;
2332
2333 if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
2334 dev_dbg(port->dev, "DMA tx %d, rx %d\n",
2335 p->dma_slave_tx, p->dma_slave_rx);
2336
2337 return 0;
2338 }
2339
2340 static void sci_cleanup_single(struct sci_port *port)
2341 {
2342 clk_put(port->iclk);
2343 clk_put(port->fclk);
2344
2345 pm_runtime_disable(port->port.dev);
2346 }
2347
2348 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2349 static void serial_console_putchar(struct uart_port *port, int ch)
2350 {
2351 sci_poll_put_char(port, ch);
2352 }
2353
2354 /*
2355 * Print a string to the serial port trying not to disturb
2356 * any possible real use of the port...
2357 */
2358 static void serial_console_write(struct console *co, const char *s,
2359 unsigned count)
2360 {
2361 struct sci_port *sci_port = &sci_ports[co->index];
2362 struct uart_port *port = &sci_port->port;
2363 unsigned short bits, ctrl;
2364 unsigned long flags;
2365 int locked = 1;
2366
2367 local_irq_save(flags);
2368 if (port->sysrq)
2369 locked = 0;
2370 else if (oops_in_progress)
2371 locked = spin_trylock(&port->lock);
2372 else
2373 spin_lock(&port->lock);
2374
2375 /* first save the SCSCR then disable the interrupts */
2376 ctrl = serial_port_in(port, SCSCR);
2377 serial_port_out(port, SCSCR, sci_port->cfg->scscr);
2378
2379 uart_console_write(port, s, count, serial_console_putchar);
2380
2381 /* wait until fifo is empty and last bit has been transmitted */
2382 bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2383 while ((serial_port_in(port, SCxSR) & bits) != bits)
2384 cpu_relax();
2385
2386 /* restore the SCSCR */
2387 serial_port_out(port, SCSCR, ctrl);
2388
2389 if (locked)
2390 spin_unlock(&port->lock);
2391 local_irq_restore(flags);
2392 }
2393
2394 static int serial_console_setup(struct console *co, char *options)
2395 {
2396 struct sci_port *sci_port;
2397 struct uart_port *port;
2398 int baud = 115200;
2399 int bits = 8;
2400 int parity = 'n';
2401 int flow = 'n';
2402 int ret;
2403
2404 /*
2405 * Refuse to handle any bogus ports.
2406 */
2407 if (co->index < 0 || co->index >= SCI_NPORTS)
2408 return -ENODEV;
2409
2410 sci_port = &sci_ports[co->index];
2411 port = &sci_port->port;
2412
2413 /*
2414 * Refuse to handle uninitialized ports.
2415 */
2416 if (!port->ops)
2417 return -ENODEV;
2418
2419 ret = sci_remap_port(port);
2420 if (unlikely(ret != 0))
2421 return ret;
2422
2423 if (options)
2424 uart_parse_options(options, &baud, &parity, &bits, &flow);
2425
2426 return uart_set_options(port, co, baud, parity, bits, flow);
2427 }
2428
2429 static struct console serial_console = {
2430 .name = "ttySC",
2431 .device = uart_console_device,
2432 .write = serial_console_write,
2433 .setup = serial_console_setup,
2434 .flags = CON_PRINTBUFFER,
2435 .index = -1,
2436 .data = &sci_uart_driver,
2437 };
2438
2439 static struct console early_serial_console = {
2440 .name = "early_ttySC",
2441 .write = serial_console_write,
2442 .flags = CON_PRINTBUFFER,
2443 .index = -1,
2444 };
2445
2446 static char early_serial_buf[32];
2447
2448 static int sci_probe_earlyprintk(struct platform_device *pdev)
2449 {
2450 struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
2451
2452 if (early_serial_console.data)
2453 return -EEXIST;
2454
2455 early_serial_console.index = pdev->id;
2456
2457 sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
2458
2459 serial_console_setup(&early_serial_console, early_serial_buf);
2460
2461 if (!strstr(early_serial_buf, "keep"))
2462 early_serial_console.flags |= CON_BOOT;
2463
2464 register_console(&early_serial_console);
2465 return 0;
2466 }
2467
2468 #define SCI_CONSOLE (&serial_console)
2469
2470 #else
2471 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
2472 {
2473 return -EINVAL;
2474 }
2475
2476 #define SCI_CONSOLE NULL
2477
2478 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
2479
2480 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
2481
2482 static struct uart_driver sci_uart_driver = {
2483 .owner = THIS_MODULE,
2484 .driver_name = "sci",
2485 .dev_name = "ttySC",
2486 .major = SCI_MAJOR,
2487 .minor = SCI_MINOR_START,
2488 .nr = SCI_NPORTS,
2489 .cons = SCI_CONSOLE,
2490 };
2491
2492 static int sci_remove(struct platform_device *dev)
2493 {
2494 struct sci_port *port = platform_get_drvdata(dev);
2495
2496 cpufreq_unregister_notifier(&port->freq_transition,
2497 CPUFREQ_TRANSITION_NOTIFIER);
2498
2499 uart_remove_one_port(&sci_uart_driver, &port->port);
2500
2501 sci_cleanup_single(port);
2502
2503 return 0;
2504 }
2505
2506 struct sci_port_info {
2507 unsigned int type;
2508 unsigned int regtype;
2509 };
2510
2511 static const struct of_device_id of_sci_match[] = {
2512 {
2513 .compatible = "renesas,scif",
2514 .data = &(const struct sci_port_info) {
2515 .type = PORT_SCIF,
2516 .regtype = SCIx_SH4_SCIF_REGTYPE,
2517 },
2518 }, {
2519 .compatible = "renesas,scifa",
2520 .data = &(const struct sci_port_info) {
2521 .type = PORT_SCIFA,
2522 .regtype = SCIx_SCIFA_REGTYPE,
2523 },
2524 }, {
2525 .compatible = "renesas,scifb",
2526 .data = &(const struct sci_port_info) {
2527 .type = PORT_SCIFB,
2528 .regtype = SCIx_SCIFB_REGTYPE,
2529 },
2530 }, {
2531 .compatible = "renesas,hscif",
2532 .data = &(const struct sci_port_info) {
2533 .type = PORT_HSCIF,
2534 .regtype = SCIx_HSCIF_REGTYPE,
2535 },
2536 }, {
2537 .compatible = "renesas,sci",
2538 .data = &(const struct sci_port_info) {
2539 .type = PORT_SCI,
2540 .regtype = SCIx_SCI_REGTYPE,
2541 },
2542 }, {
2543 /* Terminator */
2544 },
2545 };
2546 MODULE_DEVICE_TABLE(of, of_sci_match);
2547
2548 static struct plat_sci_port *
2549 sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id)
2550 {
2551 struct device_node *np = pdev->dev.of_node;
2552 const struct of_device_id *match;
2553 const struct sci_port_info *info;
2554 struct plat_sci_port *p;
2555 int id;
2556
2557 if (!IS_ENABLED(CONFIG_OF) || !np)
2558 return NULL;
2559
2560 match = of_match_node(of_sci_match, pdev->dev.of_node);
2561 if (!match)
2562 return NULL;
2563
2564 info = match->data;
2565
2566 p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
2567 if (!p) {
2568 dev_err(&pdev->dev, "failed to allocate DT config data\n");
2569 return NULL;
2570 }
2571
2572 /* Get the line number for the aliases node. */
2573 id = of_alias_get_id(np, "serial");
2574 if (id < 0) {
2575 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
2576 return NULL;
2577 }
2578
2579 *dev_id = id;
2580
2581 p->flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
2582 p->type = info->type;
2583 p->regtype = info->regtype;
2584 p->scscr = SCSCR_RE | SCSCR_TE;
2585
2586 return p;
2587 }
2588
2589 static int sci_probe_single(struct platform_device *dev,
2590 unsigned int index,
2591 struct plat_sci_port *p,
2592 struct sci_port *sciport)
2593 {
2594 int ret;
2595
2596 /* Sanity check */
2597 if (unlikely(index >= SCI_NPORTS)) {
2598 dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
2599 index+1, SCI_NPORTS);
2600 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
2601 return -EINVAL;
2602 }
2603
2604 ret = sci_init_single(dev, sciport, index, p, false);
2605 if (ret)
2606 return ret;
2607
2608 ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
2609 if (ret) {
2610 sci_cleanup_single(sciport);
2611 return ret;
2612 }
2613
2614 return 0;
2615 }
2616
2617 static int sci_probe(struct platform_device *dev)
2618 {
2619 struct plat_sci_port *p;
2620 struct sci_port *sp;
2621 unsigned int dev_id;
2622 int ret;
2623
2624 /*
2625 * If we've come here via earlyprintk initialization, head off to
2626 * the special early probe. We don't have sufficient device state
2627 * to make it beyond this yet.
2628 */
2629 if (is_early_platform_device(dev))
2630 return sci_probe_earlyprintk(dev);
2631
2632 if (dev->dev.of_node) {
2633 p = sci_parse_dt(dev, &dev_id);
2634 if (p == NULL)
2635 return -EINVAL;
2636 } else {
2637 p = dev->dev.platform_data;
2638 if (p == NULL) {
2639 dev_err(&dev->dev, "no platform data supplied\n");
2640 return -EINVAL;
2641 }
2642
2643 dev_id = dev->id;
2644 }
2645
2646 sp = &sci_ports[dev_id];
2647 platform_set_drvdata(dev, sp);
2648
2649 ret = sci_probe_single(dev, dev_id, p, sp);
2650 if (ret)
2651 return ret;
2652
2653 sp->freq_transition.notifier_call = sci_notifier;
2654
2655 ret = cpufreq_register_notifier(&sp->freq_transition,
2656 CPUFREQ_TRANSITION_NOTIFIER);
2657 if (unlikely(ret < 0)) {
2658 uart_remove_one_port(&sci_uart_driver, &sp->port);
2659 sci_cleanup_single(sp);
2660 return ret;
2661 }
2662
2663 #ifdef CONFIG_SH_STANDARD_BIOS
2664 sh_bios_gdb_detach();
2665 #endif
2666
2667 return 0;
2668 }
2669
2670 static __maybe_unused int sci_suspend(struct device *dev)
2671 {
2672 struct sci_port *sport = dev_get_drvdata(dev);
2673
2674 if (sport)
2675 uart_suspend_port(&sci_uart_driver, &sport->port);
2676
2677 return 0;
2678 }
2679
2680 static __maybe_unused int sci_resume(struct device *dev)
2681 {
2682 struct sci_port *sport = dev_get_drvdata(dev);
2683
2684 if (sport)
2685 uart_resume_port(&sci_uart_driver, &sport->port);
2686
2687 return 0;
2688 }
2689
2690 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
2691
2692 static struct platform_driver sci_driver = {
2693 .probe = sci_probe,
2694 .remove = sci_remove,
2695 .driver = {
2696 .name = "sh-sci",
2697 .pm = &sci_dev_pm_ops,
2698 .of_match_table = of_match_ptr(of_sci_match),
2699 },
2700 };
2701
2702 static int __init sci_init(void)
2703 {
2704 int ret;
2705
2706 pr_info("%s\n", banner);
2707
2708 ret = uart_register_driver(&sci_uart_driver);
2709 if (likely(ret == 0)) {
2710 ret = platform_driver_register(&sci_driver);
2711 if (unlikely(ret))
2712 uart_unregister_driver(&sci_uart_driver);
2713 }
2714
2715 return ret;
2716 }
2717
2718 static void __exit sci_exit(void)
2719 {
2720 platform_driver_unregister(&sci_driver);
2721 uart_unregister_driver(&sci_uart_driver);
2722 }
2723
2724 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2725 early_platform_init_buffer("earlyprintk", &sci_driver,
2726 early_serial_buf, ARRAY_SIZE(early_serial_buf));
2727 #endif
2728 module_init(sci_init);
2729 module_exit(sci_exit);
2730
2731 MODULE_LICENSE("GPL");
2732 MODULE_ALIAS("platform:sh-sci");
2733 MODULE_AUTHOR("Paul Mundt");
2734 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
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