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Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[deliverable/linux.git] / drivers / tty / serial / sh-sci.c
1 /*
2 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
3 *
4 * Copyright (C) 2002 - 2011 Paul Mundt
5 * Copyright (C) 2015 Glider bvba
6 * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
7 *
8 * based off of the old drivers/char/sh-sci.c by:
9 *
10 * Copyright (C) 1999, 2000 Niibe Yutaka
11 * Copyright (C) 2000 Sugioka Toshinobu
12 * Modified to support multiple serial ports. Stuart Menefy (May 2000).
13 * Modified to support SecureEdge. David McCullough (2002)
14 * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
15 * Removed SH7300 support (Jul 2007).
16 *
17 * This file is subject to the terms and conditions of the GNU General Public
18 * License. See the file "COPYING" in the main directory of this archive
19 * for more details.
20 */
21 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
22 #define SUPPORT_SYSRQ
23 #endif
24
25 #undef DEBUG
26
27 #include <linux/clk.h>
28 #include <linux/console.h>
29 #include <linux/ctype.h>
30 #include <linux/cpufreq.h>
31 #include <linux/delay.h>
32 #include <linux/dmaengine.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/err.h>
35 #include <linux/errno.h>
36 #include <linux/init.h>
37 #include <linux/interrupt.h>
38 #include <linux/ioport.h>
39 #include <linux/major.h>
40 #include <linux/module.h>
41 #include <linux/mm.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 enum SCI_CLKS {
80 SCI_FCK, /* Functional Clock */
81 SCI_SCK, /* Optional External Clock */
82 SCI_BRG_INT, /* Optional BRG Internal Clock Source */
83 SCI_SCIF_CLK, /* Optional BRG External Clock Source */
84 SCI_NUM_CLKS
85 };
86
87 struct sci_port {
88 struct uart_port port;
89
90 /* Platform configuration */
91 struct plat_sci_port *cfg;
92 unsigned int overrun_reg;
93 unsigned int overrun_mask;
94 unsigned int error_mask;
95 unsigned int error_clear;
96 unsigned int sampling_rate;
97 resource_size_t reg_size;
98
99 /* Break timer */
100 struct timer_list break_timer;
101 int break_flag;
102
103 /* Clocks */
104 struct clk *clks[SCI_NUM_CLKS];
105 unsigned long clk_rates[SCI_NUM_CLKS];
106
107 int irqs[SCIx_NR_IRQS];
108 char *irqstr[SCIx_NR_IRQS];
109
110 struct dma_chan *chan_tx;
111 struct dma_chan *chan_rx;
112
113 #ifdef CONFIG_SERIAL_SH_SCI_DMA
114 dma_cookie_t cookie_tx;
115 dma_cookie_t cookie_rx[2];
116 dma_cookie_t active_rx;
117 dma_addr_t tx_dma_addr;
118 unsigned int tx_dma_len;
119 struct scatterlist sg_rx[2];
120 void *rx_buf[2];
121 size_t buf_len_rx;
122 struct work_struct work_tx;
123 struct timer_list rx_timer;
124 unsigned int rx_timeout;
125 #endif
126 };
127
128 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
129
130 static struct sci_port sci_ports[SCI_NPORTS];
131 static struct uart_driver sci_uart_driver;
132
133 static inline struct sci_port *
134 to_sci_port(struct uart_port *uart)
135 {
136 return container_of(uart, struct sci_port, port);
137 }
138
139 struct plat_sci_reg {
140 u8 offset, size;
141 };
142
143 /* Helper for invalidating specific entries of an inherited map. */
144 #define sci_reg_invalid { .offset = 0, .size = 0 }
145
146 static const struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
147 [SCIx_PROBE_REGTYPE] = {
148 [0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
149 },
150
151 /*
152 * Common SCI definitions, dependent on the port's regshift
153 * value.
154 */
155 [SCIx_SCI_REGTYPE] = {
156 [SCSMR] = { 0x00, 8 },
157 [SCBRR] = { 0x01, 8 },
158 [SCSCR] = { 0x02, 8 },
159 [SCxTDR] = { 0x03, 8 },
160 [SCxSR] = { 0x04, 8 },
161 [SCxRDR] = { 0x05, 8 },
162 [SCFCR] = sci_reg_invalid,
163 [SCFDR] = sci_reg_invalid,
164 [SCTFDR] = sci_reg_invalid,
165 [SCRFDR] = sci_reg_invalid,
166 [SCSPTR] = sci_reg_invalid,
167 [SCLSR] = sci_reg_invalid,
168 [HSSRR] = sci_reg_invalid,
169 [SCPCR] = sci_reg_invalid,
170 [SCPDR] = sci_reg_invalid,
171 [SCDL] = sci_reg_invalid,
172 [SCCKS] = sci_reg_invalid,
173 },
174
175 /*
176 * Common definitions for legacy IrDA ports, dependent on
177 * regshift value.
178 */
179 [SCIx_IRDA_REGTYPE] = {
180 [SCSMR] = { 0x00, 8 },
181 [SCBRR] = { 0x01, 8 },
182 [SCSCR] = { 0x02, 8 },
183 [SCxTDR] = { 0x03, 8 },
184 [SCxSR] = { 0x04, 8 },
185 [SCxRDR] = { 0x05, 8 },
186 [SCFCR] = { 0x06, 8 },
187 [SCFDR] = { 0x07, 16 },
188 [SCTFDR] = sci_reg_invalid,
189 [SCRFDR] = sci_reg_invalid,
190 [SCSPTR] = sci_reg_invalid,
191 [SCLSR] = sci_reg_invalid,
192 [HSSRR] = sci_reg_invalid,
193 [SCPCR] = sci_reg_invalid,
194 [SCPDR] = sci_reg_invalid,
195 [SCDL] = sci_reg_invalid,
196 [SCCKS] = sci_reg_invalid,
197 },
198
199 /*
200 * Common SCIFA definitions.
201 */
202 [SCIx_SCIFA_REGTYPE] = {
203 [SCSMR] = { 0x00, 16 },
204 [SCBRR] = { 0x04, 8 },
205 [SCSCR] = { 0x08, 16 },
206 [SCxTDR] = { 0x20, 8 },
207 [SCxSR] = { 0x14, 16 },
208 [SCxRDR] = { 0x24, 8 },
209 [SCFCR] = { 0x18, 16 },
210 [SCFDR] = { 0x1c, 16 },
211 [SCTFDR] = sci_reg_invalid,
212 [SCRFDR] = sci_reg_invalid,
213 [SCSPTR] = sci_reg_invalid,
214 [SCLSR] = sci_reg_invalid,
215 [HSSRR] = sci_reg_invalid,
216 [SCPCR] = { 0x30, 16 },
217 [SCPDR] = { 0x34, 16 },
218 [SCDL] = sci_reg_invalid,
219 [SCCKS] = sci_reg_invalid,
220 },
221
222 /*
223 * Common SCIFB definitions.
224 */
225 [SCIx_SCIFB_REGTYPE] = {
226 [SCSMR] = { 0x00, 16 },
227 [SCBRR] = { 0x04, 8 },
228 [SCSCR] = { 0x08, 16 },
229 [SCxTDR] = { 0x40, 8 },
230 [SCxSR] = { 0x14, 16 },
231 [SCxRDR] = { 0x60, 8 },
232 [SCFCR] = { 0x18, 16 },
233 [SCFDR] = sci_reg_invalid,
234 [SCTFDR] = { 0x38, 16 },
235 [SCRFDR] = { 0x3c, 16 },
236 [SCSPTR] = sci_reg_invalid,
237 [SCLSR] = sci_reg_invalid,
238 [HSSRR] = sci_reg_invalid,
239 [SCPCR] = { 0x30, 16 },
240 [SCPDR] = { 0x34, 16 },
241 [SCDL] = sci_reg_invalid,
242 [SCCKS] = sci_reg_invalid,
243 },
244
245 /*
246 * Common SH-2(A) SCIF definitions for ports with FIFO data
247 * count registers.
248 */
249 [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
250 [SCSMR] = { 0x00, 16 },
251 [SCBRR] = { 0x04, 8 },
252 [SCSCR] = { 0x08, 16 },
253 [SCxTDR] = { 0x0c, 8 },
254 [SCxSR] = { 0x10, 16 },
255 [SCxRDR] = { 0x14, 8 },
256 [SCFCR] = { 0x18, 16 },
257 [SCFDR] = { 0x1c, 16 },
258 [SCTFDR] = sci_reg_invalid,
259 [SCRFDR] = sci_reg_invalid,
260 [SCSPTR] = { 0x20, 16 },
261 [SCLSR] = { 0x24, 16 },
262 [HSSRR] = sci_reg_invalid,
263 [SCPCR] = sci_reg_invalid,
264 [SCPDR] = sci_reg_invalid,
265 [SCDL] = sci_reg_invalid,
266 [SCCKS] = sci_reg_invalid,
267 },
268
269 /*
270 * Common SH-3 SCIF definitions.
271 */
272 [SCIx_SH3_SCIF_REGTYPE] = {
273 [SCSMR] = { 0x00, 8 },
274 [SCBRR] = { 0x02, 8 },
275 [SCSCR] = { 0x04, 8 },
276 [SCxTDR] = { 0x06, 8 },
277 [SCxSR] = { 0x08, 16 },
278 [SCxRDR] = { 0x0a, 8 },
279 [SCFCR] = { 0x0c, 8 },
280 [SCFDR] = { 0x0e, 16 },
281 [SCTFDR] = sci_reg_invalid,
282 [SCRFDR] = sci_reg_invalid,
283 [SCSPTR] = sci_reg_invalid,
284 [SCLSR] = sci_reg_invalid,
285 [HSSRR] = sci_reg_invalid,
286 [SCPCR] = sci_reg_invalid,
287 [SCPDR] = sci_reg_invalid,
288 [SCDL] = sci_reg_invalid,
289 [SCCKS] = sci_reg_invalid,
290 },
291
292 /*
293 * Common SH-4(A) SCIF(B) definitions.
294 */
295 [SCIx_SH4_SCIF_REGTYPE] = {
296 [SCSMR] = { 0x00, 16 },
297 [SCBRR] = { 0x04, 8 },
298 [SCSCR] = { 0x08, 16 },
299 [SCxTDR] = { 0x0c, 8 },
300 [SCxSR] = { 0x10, 16 },
301 [SCxRDR] = { 0x14, 8 },
302 [SCFCR] = { 0x18, 16 },
303 [SCFDR] = { 0x1c, 16 },
304 [SCTFDR] = sci_reg_invalid,
305 [SCRFDR] = sci_reg_invalid,
306 [SCSPTR] = { 0x20, 16 },
307 [SCLSR] = { 0x24, 16 },
308 [HSSRR] = sci_reg_invalid,
309 [SCPCR] = sci_reg_invalid,
310 [SCPDR] = sci_reg_invalid,
311 [SCDL] = sci_reg_invalid,
312 [SCCKS] = sci_reg_invalid,
313 },
314
315 /*
316 * Common SCIF definitions for ports with a Baud Rate Generator for
317 * External Clock (BRG).
318 */
319 [SCIx_SH4_SCIF_BRG_REGTYPE] = {
320 [SCSMR] = { 0x00, 16 },
321 [SCBRR] = { 0x04, 8 },
322 [SCSCR] = { 0x08, 16 },
323 [SCxTDR] = { 0x0c, 8 },
324 [SCxSR] = { 0x10, 16 },
325 [SCxRDR] = { 0x14, 8 },
326 [SCFCR] = { 0x18, 16 },
327 [SCFDR] = { 0x1c, 16 },
328 [SCTFDR] = sci_reg_invalid,
329 [SCRFDR] = sci_reg_invalid,
330 [SCSPTR] = { 0x20, 16 },
331 [SCLSR] = { 0x24, 16 },
332 [HSSRR] = sci_reg_invalid,
333 [SCPCR] = sci_reg_invalid,
334 [SCPDR] = sci_reg_invalid,
335 [SCDL] = { 0x30, 16 },
336 [SCCKS] = { 0x34, 16 },
337 },
338
339 /*
340 * Common HSCIF definitions.
341 */
342 [SCIx_HSCIF_REGTYPE] = {
343 [SCSMR] = { 0x00, 16 },
344 [SCBRR] = { 0x04, 8 },
345 [SCSCR] = { 0x08, 16 },
346 [SCxTDR] = { 0x0c, 8 },
347 [SCxSR] = { 0x10, 16 },
348 [SCxRDR] = { 0x14, 8 },
349 [SCFCR] = { 0x18, 16 },
350 [SCFDR] = { 0x1c, 16 },
351 [SCTFDR] = sci_reg_invalid,
352 [SCRFDR] = sci_reg_invalid,
353 [SCSPTR] = { 0x20, 16 },
354 [SCLSR] = { 0x24, 16 },
355 [HSSRR] = { 0x40, 16 },
356 [SCPCR] = sci_reg_invalid,
357 [SCPDR] = sci_reg_invalid,
358 [SCDL] = { 0x30, 16 },
359 [SCCKS] = { 0x34, 16 },
360 },
361
362 /*
363 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
364 * register.
365 */
366 [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
367 [SCSMR] = { 0x00, 16 },
368 [SCBRR] = { 0x04, 8 },
369 [SCSCR] = { 0x08, 16 },
370 [SCxTDR] = { 0x0c, 8 },
371 [SCxSR] = { 0x10, 16 },
372 [SCxRDR] = { 0x14, 8 },
373 [SCFCR] = { 0x18, 16 },
374 [SCFDR] = { 0x1c, 16 },
375 [SCTFDR] = sci_reg_invalid,
376 [SCRFDR] = sci_reg_invalid,
377 [SCSPTR] = sci_reg_invalid,
378 [SCLSR] = { 0x24, 16 },
379 [HSSRR] = sci_reg_invalid,
380 [SCPCR] = sci_reg_invalid,
381 [SCPDR] = sci_reg_invalid,
382 [SCDL] = sci_reg_invalid,
383 [SCCKS] = sci_reg_invalid,
384 },
385
386 /*
387 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
388 * count registers.
389 */
390 [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
391 [SCSMR] = { 0x00, 16 },
392 [SCBRR] = { 0x04, 8 },
393 [SCSCR] = { 0x08, 16 },
394 [SCxTDR] = { 0x0c, 8 },
395 [SCxSR] = { 0x10, 16 },
396 [SCxRDR] = { 0x14, 8 },
397 [SCFCR] = { 0x18, 16 },
398 [SCFDR] = { 0x1c, 16 },
399 [SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */
400 [SCRFDR] = { 0x20, 16 },
401 [SCSPTR] = { 0x24, 16 },
402 [SCLSR] = { 0x28, 16 },
403 [HSSRR] = sci_reg_invalid,
404 [SCPCR] = sci_reg_invalid,
405 [SCPDR] = sci_reg_invalid,
406 [SCDL] = sci_reg_invalid,
407 [SCCKS] = sci_reg_invalid,
408 },
409
410 /*
411 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
412 * registers.
413 */
414 [SCIx_SH7705_SCIF_REGTYPE] = {
415 [SCSMR] = { 0x00, 16 },
416 [SCBRR] = { 0x04, 8 },
417 [SCSCR] = { 0x08, 16 },
418 [SCxTDR] = { 0x20, 8 },
419 [SCxSR] = { 0x14, 16 },
420 [SCxRDR] = { 0x24, 8 },
421 [SCFCR] = { 0x18, 16 },
422 [SCFDR] = { 0x1c, 16 },
423 [SCTFDR] = sci_reg_invalid,
424 [SCRFDR] = sci_reg_invalid,
425 [SCSPTR] = sci_reg_invalid,
426 [SCLSR] = sci_reg_invalid,
427 [HSSRR] = sci_reg_invalid,
428 [SCPCR] = sci_reg_invalid,
429 [SCPDR] = sci_reg_invalid,
430 [SCDL] = sci_reg_invalid,
431 [SCCKS] = sci_reg_invalid,
432 },
433 };
434
435 #define sci_getreg(up, offset) (sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
436
437 /*
438 * The "offset" here is rather misleading, in that it refers to an enum
439 * value relative to the port mapping rather than the fixed offset
440 * itself, which needs to be manually retrieved from the platform's
441 * register map for the given port.
442 */
443 static unsigned int sci_serial_in(struct uart_port *p, int offset)
444 {
445 const struct plat_sci_reg *reg = sci_getreg(p, offset);
446
447 if (reg->size == 8)
448 return ioread8(p->membase + (reg->offset << p->regshift));
449 else if (reg->size == 16)
450 return ioread16(p->membase + (reg->offset << p->regshift));
451 else
452 WARN(1, "Invalid register access\n");
453
454 return 0;
455 }
456
457 static void sci_serial_out(struct uart_port *p, int offset, int value)
458 {
459 const struct plat_sci_reg *reg = sci_getreg(p, offset);
460
461 if (reg->size == 8)
462 iowrite8(value, p->membase + (reg->offset << p->regshift));
463 else if (reg->size == 16)
464 iowrite16(value, p->membase + (reg->offset << p->regshift));
465 else
466 WARN(1, "Invalid register access\n");
467 }
468
469 static int sci_probe_regmap(struct plat_sci_port *cfg)
470 {
471 switch (cfg->type) {
472 case PORT_SCI:
473 cfg->regtype = SCIx_SCI_REGTYPE;
474 break;
475 case PORT_IRDA:
476 cfg->regtype = SCIx_IRDA_REGTYPE;
477 break;
478 case PORT_SCIFA:
479 cfg->regtype = SCIx_SCIFA_REGTYPE;
480 break;
481 case PORT_SCIFB:
482 cfg->regtype = SCIx_SCIFB_REGTYPE;
483 break;
484 case PORT_SCIF:
485 /*
486 * The SH-4 is a bit of a misnomer here, although that's
487 * where this particular port layout originated. This
488 * configuration (or some slight variation thereof)
489 * remains the dominant model for all SCIFs.
490 */
491 cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
492 break;
493 case PORT_HSCIF:
494 cfg->regtype = SCIx_HSCIF_REGTYPE;
495 break;
496 default:
497 pr_err("Can't probe register map for given port\n");
498 return -EINVAL;
499 }
500
501 return 0;
502 }
503
504 static void sci_port_enable(struct sci_port *sci_port)
505 {
506 unsigned int i;
507
508 if (!sci_port->port.dev)
509 return;
510
511 pm_runtime_get_sync(sci_port->port.dev);
512
513 for (i = 0; i < SCI_NUM_CLKS; i++) {
514 clk_prepare_enable(sci_port->clks[i]);
515 sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
516 }
517 sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
518 }
519
520 static void sci_port_disable(struct sci_port *sci_port)
521 {
522 unsigned int i;
523
524 if (!sci_port->port.dev)
525 return;
526
527 /* Cancel the break timer to ensure that the timer handler will not try
528 * to access the hardware with clocks and power disabled. Reset the
529 * break flag to make the break debouncing state machine ready for the
530 * next break.
531 */
532 del_timer_sync(&sci_port->break_timer);
533 sci_port->break_flag = 0;
534
535 for (i = SCI_NUM_CLKS; i-- > 0; )
536 clk_disable_unprepare(sci_port->clks[i]);
537
538 pm_runtime_put_sync(sci_port->port.dev);
539 }
540
541 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
542 {
543 /*
544 * Not all ports (such as SCIFA) will support REIE. Rather than
545 * special-casing the port type, we check the port initialization
546 * IRQ enable mask to see whether the IRQ is desired at all. If
547 * it's unset, it's logically inferred that there's no point in
548 * testing for it.
549 */
550 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
551 }
552
553 static void sci_start_tx(struct uart_port *port)
554 {
555 struct sci_port *s = to_sci_port(port);
556 unsigned short ctrl;
557
558 #ifdef CONFIG_SERIAL_SH_SCI_DMA
559 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
560 u16 new, scr = serial_port_in(port, SCSCR);
561 if (s->chan_tx)
562 new = scr | SCSCR_TDRQE;
563 else
564 new = scr & ~SCSCR_TDRQE;
565 if (new != scr)
566 serial_port_out(port, SCSCR, new);
567 }
568
569 if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
570 dma_submit_error(s->cookie_tx)) {
571 s->cookie_tx = 0;
572 schedule_work(&s->work_tx);
573 }
574 #endif
575
576 if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
577 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
578 ctrl = serial_port_in(port, SCSCR);
579 serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
580 }
581 }
582
583 static void sci_stop_tx(struct uart_port *port)
584 {
585 unsigned short ctrl;
586
587 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
588 ctrl = serial_port_in(port, SCSCR);
589
590 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
591 ctrl &= ~SCSCR_TDRQE;
592
593 ctrl &= ~SCSCR_TIE;
594
595 serial_port_out(port, SCSCR, ctrl);
596 }
597
598 static void sci_start_rx(struct uart_port *port)
599 {
600 unsigned short ctrl;
601
602 ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
603
604 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
605 ctrl &= ~SCSCR_RDRQE;
606
607 serial_port_out(port, SCSCR, ctrl);
608 }
609
610 static void sci_stop_rx(struct uart_port *port)
611 {
612 unsigned short ctrl;
613
614 ctrl = serial_port_in(port, SCSCR);
615
616 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
617 ctrl &= ~SCSCR_RDRQE;
618
619 ctrl &= ~port_rx_irq_mask(port);
620
621 serial_port_out(port, SCSCR, ctrl);
622 }
623
624 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
625 {
626 if (port->type == PORT_SCI) {
627 /* Just store the mask */
628 serial_port_out(port, SCxSR, mask);
629 } else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) {
630 /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
631 /* Only clear the status bits we want to clear */
632 serial_port_out(port, SCxSR,
633 serial_port_in(port, SCxSR) & mask);
634 } else {
635 /* Store the mask, clear parity/framing errors */
636 serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
637 }
638 }
639
640 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
641
642 #ifdef CONFIG_CONSOLE_POLL
643 static int sci_poll_get_char(struct uart_port *port)
644 {
645 unsigned short status;
646 int c;
647
648 do {
649 status = serial_port_in(port, SCxSR);
650 if (status & SCxSR_ERRORS(port)) {
651 sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
652 continue;
653 }
654 break;
655 } while (1);
656
657 if (!(status & SCxSR_RDxF(port)))
658 return NO_POLL_CHAR;
659
660 c = serial_port_in(port, SCxRDR);
661
662 /* Dummy read */
663 serial_port_in(port, SCxSR);
664 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
665
666 return c;
667 }
668 #endif
669
670 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
671 {
672 unsigned short status;
673
674 do {
675 status = serial_port_in(port, SCxSR);
676 } while (!(status & SCxSR_TDxE(port)));
677
678 serial_port_out(port, SCxTDR, c);
679 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
680 }
681 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
682
683 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
684 {
685 struct sci_port *s = to_sci_port(port);
686 const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
687
688 /*
689 * Use port-specific handler if provided.
690 */
691 if (s->cfg->ops && s->cfg->ops->init_pins) {
692 s->cfg->ops->init_pins(port, cflag);
693 return;
694 }
695
696 /*
697 * For the generic path SCSPTR is necessary. Bail out if that's
698 * unavailable, too.
699 */
700 if (!reg->size)
701 return;
702
703 if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
704 ((!(cflag & CRTSCTS)))) {
705 unsigned short status;
706
707 status = serial_port_in(port, SCSPTR);
708 status &= ~SCSPTR_CTSIO;
709 status |= SCSPTR_RTSIO;
710 serial_port_out(port, SCSPTR, status); /* Set RTS = 1 */
711 }
712 }
713
714 static int sci_txfill(struct uart_port *port)
715 {
716 const struct plat_sci_reg *reg;
717
718 reg = sci_getreg(port, SCTFDR);
719 if (reg->size)
720 return serial_port_in(port, SCTFDR) & ((port->fifosize << 1) - 1);
721
722 reg = sci_getreg(port, SCFDR);
723 if (reg->size)
724 return serial_port_in(port, SCFDR) >> 8;
725
726 return !(serial_port_in(port, SCxSR) & SCI_TDRE);
727 }
728
729 static int sci_txroom(struct uart_port *port)
730 {
731 return port->fifosize - sci_txfill(port);
732 }
733
734 static int sci_rxfill(struct uart_port *port)
735 {
736 const struct plat_sci_reg *reg;
737
738 reg = sci_getreg(port, SCRFDR);
739 if (reg->size)
740 return serial_port_in(port, SCRFDR) & ((port->fifosize << 1) - 1);
741
742 reg = sci_getreg(port, SCFDR);
743 if (reg->size)
744 return serial_port_in(port, SCFDR) & ((port->fifosize << 1) - 1);
745
746 return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
747 }
748
749 /*
750 * SCI helper for checking the state of the muxed port/RXD pins.
751 */
752 static inline int sci_rxd_in(struct uart_port *port)
753 {
754 struct sci_port *s = to_sci_port(port);
755
756 if (s->cfg->port_reg <= 0)
757 return 1;
758
759 /* Cast for ARM damage */
760 return !!__raw_readb((void __iomem *)(uintptr_t)s->cfg->port_reg);
761 }
762
763 /* ********************************************************************** *
764 * the interrupt related routines *
765 * ********************************************************************** */
766
767 static void sci_transmit_chars(struct uart_port *port)
768 {
769 struct circ_buf *xmit = &port->state->xmit;
770 unsigned int stopped = uart_tx_stopped(port);
771 unsigned short status;
772 unsigned short ctrl;
773 int count;
774
775 status = serial_port_in(port, SCxSR);
776 if (!(status & SCxSR_TDxE(port))) {
777 ctrl = serial_port_in(port, SCSCR);
778 if (uart_circ_empty(xmit))
779 ctrl &= ~SCSCR_TIE;
780 else
781 ctrl |= SCSCR_TIE;
782 serial_port_out(port, SCSCR, ctrl);
783 return;
784 }
785
786 count = sci_txroom(port);
787
788 do {
789 unsigned char c;
790
791 if (port->x_char) {
792 c = port->x_char;
793 port->x_char = 0;
794 } else if (!uart_circ_empty(xmit) && !stopped) {
795 c = xmit->buf[xmit->tail];
796 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
797 } else {
798 break;
799 }
800
801 serial_port_out(port, SCxTDR, c);
802
803 port->icount.tx++;
804 } while (--count > 0);
805
806 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
807
808 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
809 uart_write_wakeup(port);
810 if (uart_circ_empty(xmit)) {
811 sci_stop_tx(port);
812 } else {
813 ctrl = serial_port_in(port, SCSCR);
814
815 if (port->type != PORT_SCI) {
816 serial_port_in(port, SCxSR); /* Dummy read */
817 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
818 }
819
820 ctrl |= SCSCR_TIE;
821 serial_port_out(port, SCSCR, ctrl);
822 }
823 }
824
825 /* On SH3, SCIF may read end-of-break as a space->mark char */
826 #define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); })
827
828 static void sci_receive_chars(struct uart_port *port)
829 {
830 struct sci_port *sci_port = to_sci_port(port);
831 struct tty_port *tport = &port->state->port;
832 int i, count, copied = 0;
833 unsigned short status;
834 unsigned char flag;
835
836 status = serial_port_in(port, SCxSR);
837 if (!(status & SCxSR_RDxF(port)))
838 return;
839
840 while (1) {
841 /* Don't copy more bytes than there is room for in the buffer */
842 count = tty_buffer_request_room(tport, sci_rxfill(port));
843
844 /* If for any reason we can't copy more data, we're done! */
845 if (count == 0)
846 break;
847
848 if (port->type == PORT_SCI) {
849 char c = serial_port_in(port, SCxRDR);
850 if (uart_handle_sysrq_char(port, c) ||
851 sci_port->break_flag)
852 count = 0;
853 else
854 tty_insert_flip_char(tport, c, TTY_NORMAL);
855 } else {
856 for (i = 0; i < count; i++) {
857 char c = serial_port_in(port, SCxRDR);
858
859 status = serial_port_in(port, SCxSR);
860 #if defined(CONFIG_CPU_SH3)
861 /* Skip "chars" during break */
862 if (sci_port->break_flag) {
863 if ((c == 0) &&
864 (status & SCxSR_FER(port))) {
865 count--; i--;
866 continue;
867 }
868
869 /* Nonzero => end-of-break */
870 dev_dbg(port->dev, "debounce<%02x>\n", c);
871 sci_port->break_flag = 0;
872
873 if (STEPFN(c)) {
874 count--; i--;
875 continue;
876 }
877 }
878 #endif /* CONFIG_CPU_SH3 */
879 if (uart_handle_sysrq_char(port, c)) {
880 count--; i--;
881 continue;
882 }
883
884 /* Store data and status */
885 if (status & SCxSR_FER(port)) {
886 flag = TTY_FRAME;
887 port->icount.frame++;
888 dev_notice(port->dev, "frame error\n");
889 } else if (status & SCxSR_PER(port)) {
890 flag = TTY_PARITY;
891 port->icount.parity++;
892 dev_notice(port->dev, "parity error\n");
893 } else
894 flag = TTY_NORMAL;
895
896 tty_insert_flip_char(tport, c, flag);
897 }
898 }
899
900 serial_port_in(port, SCxSR); /* dummy read */
901 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
902
903 copied += count;
904 port->icount.rx += count;
905 }
906
907 if (copied) {
908 /* Tell the rest of the system the news. New characters! */
909 tty_flip_buffer_push(tport);
910 } else {
911 serial_port_in(port, SCxSR); /* dummy read */
912 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
913 }
914 }
915
916 #define SCI_BREAK_JIFFIES (HZ/20)
917
918 /*
919 * The sci generates interrupts during the break,
920 * 1 per millisecond or so during the break period, for 9600 baud.
921 * So dont bother disabling interrupts.
922 * But dont want more than 1 break event.
923 * Use a kernel timer to periodically poll the rx line until
924 * the break is finished.
925 */
926 static inline void sci_schedule_break_timer(struct sci_port *port)
927 {
928 mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
929 }
930
931 /* Ensure that two consecutive samples find the break over. */
932 static void sci_break_timer(unsigned long data)
933 {
934 struct sci_port *port = (struct sci_port *)data;
935
936 if (sci_rxd_in(&port->port) == 0) {
937 port->break_flag = 1;
938 sci_schedule_break_timer(port);
939 } else if (port->break_flag == 1) {
940 /* break is over. */
941 port->break_flag = 2;
942 sci_schedule_break_timer(port);
943 } else
944 port->break_flag = 0;
945 }
946
947 static int sci_handle_errors(struct uart_port *port)
948 {
949 int copied = 0;
950 unsigned short status = serial_port_in(port, SCxSR);
951 struct tty_port *tport = &port->state->port;
952 struct sci_port *s = to_sci_port(port);
953
954 /* Handle overruns */
955 if (status & s->overrun_mask) {
956 port->icount.overrun++;
957
958 /* overrun error */
959 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
960 copied++;
961
962 dev_notice(port->dev, "overrun error\n");
963 }
964
965 if (status & SCxSR_FER(port)) {
966 if (sci_rxd_in(port) == 0) {
967 /* Notify of BREAK */
968 struct sci_port *sci_port = to_sci_port(port);
969
970 if (!sci_port->break_flag) {
971 port->icount.brk++;
972
973 sci_port->break_flag = 1;
974 sci_schedule_break_timer(sci_port);
975
976 /* Do sysrq handling. */
977 if (uart_handle_break(port))
978 return 0;
979
980 dev_dbg(port->dev, "BREAK detected\n");
981
982 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
983 copied++;
984 }
985
986 } else {
987 /* frame error */
988 port->icount.frame++;
989
990 if (tty_insert_flip_char(tport, 0, TTY_FRAME))
991 copied++;
992
993 dev_notice(port->dev, "frame error\n");
994 }
995 }
996
997 if (status & SCxSR_PER(port)) {
998 /* parity error */
999 port->icount.parity++;
1000
1001 if (tty_insert_flip_char(tport, 0, TTY_PARITY))
1002 copied++;
1003
1004 dev_notice(port->dev, "parity error\n");
1005 }
1006
1007 if (copied)
1008 tty_flip_buffer_push(tport);
1009
1010 return copied;
1011 }
1012
1013 static int sci_handle_fifo_overrun(struct uart_port *port)
1014 {
1015 struct tty_port *tport = &port->state->port;
1016 struct sci_port *s = to_sci_port(port);
1017 const struct plat_sci_reg *reg;
1018 int copied = 0;
1019 u16 status;
1020
1021 reg = sci_getreg(port, s->overrun_reg);
1022 if (!reg->size)
1023 return 0;
1024
1025 status = serial_port_in(port, s->overrun_reg);
1026 if (status & s->overrun_mask) {
1027 status &= ~s->overrun_mask;
1028 serial_port_out(port, s->overrun_reg, status);
1029
1030 port->icount.overrun++;
1031
1032 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1033 tty_flip_buffer_push(tport);
1034
1035 dev_dbg(port->dev, "overrun error\n");
1036 copied++;
1037 }
1038
1039 return copied;
1040 }
1041
1042 static int sci_handle_breaks(struct uart_port *port)
1043 {
1044 int copied = 0;
1045 unsigned short status = serial_port_in(port, SCxSR);
1046 struct tty_port *tport = &port->state->port;
1047 struct sci_port *s = to_sci_port(port);
1048
1049 if (uart_handle_break(port))
1050 return 0;
1051
1052 if (!s->break_flag && status & SCxSR_BRK(port)) {
1053 #if defined(CONFIG_CPU_SH3)
1054 /* Debounce break */
1055 s->break_flag = 1;
1056 #endif
1057
1058 port->icount.brk++;
1059
1060 /* Notify of BREAK */
1061 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1062 copied++;
1063
1064 dev_dbg(port->dev, "BREAK detected\n");
1065 }
1066
1067 if (copied)
1068 tty_flip_buffer_push(tport);
1069
1070 copied += sci_handle_fifo_overrun(port);
1071
1072 return copied;
1073 }
1074
1075 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1076 static void sci_dma_tx_complete(void *arg)
1077 {
1078 struct sci_port *s = arg;
1079 struct uart_port *port = &s->port;
1080 struct circ_buf *xmit = &port->state->xmit;
1081 unsigned long flags;
1082
1083 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1084
1085 spin_lock_irqsave(&port->lock, flags);
1086
1087 xmit->tail += s->tx_dma_len;
1088 xmit->tail &= UART_XMIT_SIZE - 1;
1089
1090 port->icount.tx += s->tx_dma_len;
1091
1092 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1093 uart_write_wakeup(port);
1094
1095 if (!uart_circ_empty(xmit)) {
1096 s->cookie_tx = 0;
1097 schedule_work(&s->work_tx);
1098 } else {
1099 s->cookie_tx = -EINVAL;
1100 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1101 u16 ctrl = serial_port_in(port, SCSCR);
1102 serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1103 }
1104 }
1105
1106 spin_unlock_irqrestore(&port->lock, flags);
1107 }
1108
1109 /* Locking: called with port lock held */
1110 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1111 {
1112 struct uart_port *port = &s->port;
1113 struct tty_port *tport = &port->state->port;
1114 int copied;
1115
1116 copied = tty_insert_flip_string(tport, buf, count);
1117 if (copied < count) {
1118 dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n",
1119 count - copied);
1120 port->icount.buf_overrun++;
1121 }
1122
1123 port->icount.rx += copied;
1124
1125 return copied;
1126 }
1127
1128 static int sci_dma_rx_find_active(struct sci_port *s)
1129 {
1130 unsigned int i;
1131
1132 for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1133 if (s->active_rx == s->cookie_rx[i])
1134 return i;
1135
1136 dev_err(s->port.dev, "%s: Rx cookie %d not found!\n", __func__,
1137 s->active_rx);
1138 return -1;
1139 }
1140
1141 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1142 {
1143 struct dma_chan *chan = s->chan_rx;
1144 struct uart_port *port = &s->port;
1145 unsigned long flags;
1146
1147 spin_lock_irqsave(&port->lock, flags);
1148 s->chan_rx = NULL;
1149 s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1150 spin_unlock_irqrestore(&port->lock, flags);
1151 dmaengine_terminate_all(chan);
1152 dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1153 sg_dma_address(&s->sg_rx[0]));
1154 dma_release_channel(chan);
1155 if (enable_pio)
1156 sci_start_rx(port);
1157 }
1158
1159 static void sci_dma_rx_complete(void *arg)
1160 {
1161 struct sci_port *s = arg;
1162 struct dma_chan *chan = s->chan_rx;
1163 struct uart_port *port = &s->port;
1164 struct dma_async_tx_descriptor *desc;
1165 unsigned long flags;
1166 int active, count = 0;
1167
1168 dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1169 s->active_rx);
1170
1171 spin_lock_irqsave(&port->lock, flags);
1172
1173 active = sci_dma_rx_find_active(s);
1174 if (active >= 0)
1175 count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1176
1177 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1178
1179 if (count)
1180 tty_flip_buffer_push(&port->state->port);
1181
1182 desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1183 DMA_DEV_TO_MEM,
1184 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1185 if (!desc)
1186 goto fail;
1187
1188 desc->callback = sci_dma_rx_complete;
1189 desc->callback_param = s;
1190 s->cookie_rx[active] = dmaengine_submit(desc);
1191 if (dma_submit_error(s->cookie_rx[active]))
1192 goto fail;
1193
1194 s->active_rx = s->cookie_rx[!active];
1195
1196 dma_async_issue_pending(chan);
1197
1198 dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1199 __func__, s->cookie_rx[active], active, s->active_rx);
1200 spin_unlock_irqrestore(&port->lock, flags);
1201 return;
1202
1203 fail:
1204 spin_unlock_irqrestore(&port->lock, flags);
1205 dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1206 sci_rx_dma_release(s, true);
1207 }
1208
1209 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1210 {
1211 struct dma_chan *chan = s->chan_tx;
1212 struct uart_port *port = &s->port;
1213 unsigned long flags;
1214
1215 spin_lock_irqsave(&port->lock, flags);
1216 s->chan_tx = NULL;
1217 s->cookie_tx = -EINVAL;
1218 spin_unlock_irqrestore(&port->lock, flags);
1219 dmaengine_terminate_all(chan);
1220 dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1221 DMA_TO_DEVICE);
1222 dma_release_channel(chan);
1223 if (enable_pio)
1224 sci_start_tx(port);
1225 }
1226
1227 static void sci_submit_rx(struct sci_port *s)
1228 {
1229 struct dma_chan *chan = s->chan_rx;
1230 int i;
1231
1232 for (i = 0; i < 2; i++) {
1233 struct scatterlist *sg = &s->sg_rx[i];
1234 struct dma_async_tx_descriptor *desc;
1235
1236 desc = dmaengine_prep_slave_sg(chan,
1237 sg, 1, DMA_DEV_TO_MEM,
1238 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1239 if (!desc)
1240 goto fail;
1241
1242 desc->callback = sci_dma_rx_complete;
1243 desc->callback_param = s;
1244 s->cookie_rx[i] = dmaengine_submit(desc);
1245 if (dma_submit_error(s->cookie_rx[i]))
1246 goto fail;
1247
1248 dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1249 s->cookie_rx[i], i);
1250 }
1251
1252 s->active_rx = s->cookie_rx[0];
1253
1254 dma_async_issue_pending(chan);
1255 return;
1256
1257 fail:
1258 if (i)
1259 dmaengine_terminate_all(chan);
1260 for (i = 0; i < 2; i++)
1261 s->cookie_rx[i] = -EINVAL;
1262 s->active_rx = -EINVAL;
1263 dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n");
1264 sci_rx_dma_release(s, true);
1265 }
1266
1267 static void work_fn_tx(struct work_struct *work)
1268 {
1269 struct sci_port *s = container_of(work, struct sci_port, work_tx);
1270 struct dma_async_tx_descriptor *desc;
1271 struct dma_chan *chan = s->chan_tx;
1272 struct uart_port *port = &s->port;
1273 struct circ_buf *xmit = &port->state->xmit;
1274 dma_addr_t buf;
1275
1276 /*
1277 * DMA is idle now.
1278 * Port xmit buffer is already mapped, and it is one page... Just adjust
1279 * offsets and lengths. Since it is a circular buffer, we have to
1280 * transmit till the end, and then the rest. Take the port lock to get a
1281 * consistent xmit buffer state.
1282 */
1283 spin_lock_irq(&port->lock);
1284 buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1285 s->tx_dma_len = min_t(unsigned int,
1286 CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1287 CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1288 spin_unlock_irq(&port->lock);
1289
1290 desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1291 DMA_MEM_TO_DEV,
1292 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1293 if (!desc) {
1294 dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1295 /* switch to PIO */
1296 sci_tx_dma_release(s, true);
1297 return;
1298 }
1299
1300 dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1301 DMA_TO_DEVICE);
1302
1303 spin_lock_irq(&port->lock);
1304 desc->callback = sci_dma_tx_complete;
1305 desc->callback_param = s;
1306 spin_unlock_irq(&port->lock);
1307 s->cookie_tx = dmaengine_submit(desc);
1308 if (dma_submit_error(s->cookie_tx)) {
1309 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1310 /* switch to PIO */
1311 sci_tx_dma_release(s, true);
1312 return;
1313 }
1314
1315 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1316 __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1317
1318 dma_async_issue_pending(chan);
1319 }
1320
1321 static void rx_timer_fn(unsigned long arg)
1322 {
1323 struct sci_port *s = (struct sci_port *)arg;
1324 struct dma_chan *chan = s->chan_rx;
1325 struct uart_port *port = &s->port;
1326 struct dma_tx_state state;
1327 enum dma_status status;
1328 unsigned long flags;
1329 unsigned int read;
1330 int active, count;
1331 u16 scr;
1332
1333 spin_lock_irqsave(&port->lock, flags);
1334
1335 dev_dbg(port->dev, "DMA Rx timed out\n");
1336
1337 active = sci_dma_rx_find_active(s);
1338 if (active < 0) {
1339 spin_unlock_irqrestore(&port->lock, flags);
1340 return;
1341 }
1342
1343 status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1344 if (status == DMA_COMPLETE) {
1345 dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1346 s->active_rx, active);
1347 spin_unlock_irqrestore(&port->lock, flags);
1348
1349 /* Let packet complete handler take care of the packet */
1350 return;
1351 }
1352
1353 dmaengine_pause(chan);
1354
1355 /*
1356 * sometimes DMA transfer doesn't stop even if it is stopped and
1357 * data keeps on coming until transaction is complete so check
1358 * for DMA_COMPLETE again
1359 * Let packet complete handler take care of the packet
1360 */
1361 status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1362 if (status == DMA_COMPLETE) {
1363 spin_unlock_irqrestore(&port->lock, flags);
1364 dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1365 return;
1366 }
1367
1368 /* Handle incomplete DMA receive */
1369 dmaengine_terminate_all(s->chan_rx);
1370 read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1371 dev_dbg(port->dev, "Read %u bytes with cookie %d\n", read,
1372 s->active_rx);
1373
1374 if (read) {
1375 count = sci_dma_rx_push(s, s->rx_buf[active], read);
1376 if (count)
1377 tty_flip_buffer_push(&port->state->port);
1378 }
1379
1380 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1381 sci_submit_rx(s);
1382
1383 /* Direct new serial port interrupts back to CPU */
1384 scr = serial_port_in(port, SCSCR);
1385 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1386 scr &= ~SCSCR_RDRQE;
1387 enable_irq(s->irqs[SCIx_RXI_IRQ]);
1388 }
1389 serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1390
1391 spin_unlock_irqrestore(&port->lock, flags);
1392 }
1393
1394 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1395 enum dma_transfer_direction dir,
1396 unsigned int id)
1397 {
1398 dma_cap_mask_t mask;
1399 struct dma_chan *chan;
1400 struct dma_slave_config cfg;
1401 int ret;
1402
1403 dma_cap_zero(mask);
1404 dma_cap_set(DMA_SLAVE, mask);
1405
1406 chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1407 (void *)(unsigned long)id, port->dev,
1408 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1409 if (!chan) {
1410 dev_warn(port->dev,
1411 "dma_request_slave_channel_compat failed\n");
1412 return NULL;
1413 }
1414
1415 memset(&cfg, 0, sizeof(cfg));
1416 cfg.direction = dir;
1417 if (dir == DMA_MEM_TO_DEV) {
1418 cfg.dst_addr = port->mapbase +
1419 (sci_getreg(port, SCxTDR)->offset << port->regshift);
1420 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1421 } else {
1422 cfg.src_addr = port->mapbase +
1423 (sci_getreg(port, SCxRDR)->offset << port->regshift);
1424 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1425 }
1426
1427 ret = dmaengine_slave_config(chan, &cfg);
1428 if (ret) {
1429 dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1430 dma_release_channel(chan);
1431 return NULL;
1432 }
1433
1434 return chan;
1435 }
1436
1437 static void sci_request_dma(struct uart_port *port)
1438 {
1439 struct sci_port *s = to_sci_port(port);
1440 struct dma_chan *chan;
1441
1442 dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1443
1444 if (!port->dev->of_node &&
1445 (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0))
1446 return;
1447
1448 s->cookie_tx = -EINVAL;
1449 chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV, s->cfg->dma_slave_tx);
1450 dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1451 if (chan) {
1452 s->chan_tx = chan;
1453 /* UART circular tx buffer is an aligned page. */
1454 s->tx_dma_addr = dma_map_single(chan->device->dev,
1455 port->state->xmit.buf,
1456 UART_XMIT_SIZE,
1457 DMA_TO_DEVICE);
1458 if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1459 dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1460 dma_release_channel(chan);
1461 s->chan_tx = NULL;
1462 } else {
1463 dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1464 __func__, UART_XMIT_SIZE,
1465 port->state->xmit.buf, &s->tx_dma_addr);
1466 }
1467
1468 INIT_WORK(&s->work_tx, work_fn_tx);
1469 }
1470
1471 chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM, s->cfg->dma_slave_rx);
1472 dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1473 if (chan) {
1474 unsigned int i;
1475 dma_addr_t dma;
1476 void *buf;
1477
1478 s->chan_rx = chan;
1479
1480 s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1481 buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1482 &dma, GFP_KERNEL);
1483 if (!buf) {
1484 dev_warn(port->dev,
1485 "Failed to allocate Rx dma buffer, using PIO\n");
1486 dma_release_channel(chan);
1487 s->chan_rx = NULL;
1488 return;
1489 }
1490
1491 for (i = 0; i < 2; i++) {
1492 struct scatterlist *sg = &s->sg_rx[i];
1493
1494 sg_init_table(sg, 1);
1495 s->rx_buf[i] = buf;
1496 sg_dma_address(sg) = dma;
1497 sg_dma_len(sg) = s->buf_len_rx;
1498
1499 buf += s->buf_len_rx;
1500 dma += s->buf_len_rx;
1501 }
1502
1503 setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1504
1505 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1506 sci_submit_rx(s);
1507 }
1508 }
1509
1510 static void sci_free_dma(struct uart_port *port)
1511 {
1512 struct sci_port *s = to_sci_port(port);
1513
1514 if (s->chan_tx)
1515 sci_tx_dma_release(s, false);
1516 if (s->chan_rx)
1517 sci_rx_dma_release(s, false);
1518 }
1519 #else
1520 static inline void sci_request_dma(struct uart_port *port)
1521 {
1522 }
1523
1524 static inline void sci_free_dma(struct uart_port *port)
1525 {
1526 }
1527 #endif
1528
1529 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1530 {
1531 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1532 struct uart_port *port = ptr;
1533 struct sci_port *s = to_sci_port(port);
1534
1535 if (s->chan_rx) {
1536 u16 scr = serial_port_in(port, SCSCR);
1537 u16 ssr = serial_port_in(port, SCxSR);
1538
1539 /* Disable future Rx interrupts */
1540 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1541 disable_irq_nosync(irq);
1542 scr |= SCSCR_RDRQE;
1543 } else {
1544 scr &= ~SCSCR_RIE;
1545 sci_submit_rx(s);
1546 }
1547 serial_port_out(port, SCSCR, scr);
1548 /* Clear current interrupt */
1549 serial_port_out(port, SCxSR,
1550 ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1551 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
1552 jiffies, s->rx_timeout);
1553 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1554
1555 return IRQ_HANDLED;
1556 }
1557 #endif
1558
1559 /* I think sci_receive_chars has to be called irrespective
1560 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1561 * to be disabled?
1562 */
1563 sci_receive_chars(ptr);
1564
1565 return IRQ_HANDLED;
1566 }
1567
1568 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1569 {
1570 struct uart_port *port = ptr;
1571 unsigned long flags;
1572
1573 spin_lock_irqsave(&port->lock, flags);
1574 sci_transmit_chars(port);
1575 spin_unlock_irqrestore(&port->lock, flags);
1576
1577 return IRQ_HANDLED;
1578 }
1579
1580 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1581 {
1582 struct uart_port *port = ptr;
1583 struct sci_port *s = to_sci_port(port);
1584
1585 /* Handle errors */
1586 if (port->type == PORT_SCI) {
1587 if (sci_handle_errors(port)) {
1588 /* discard character in rx buffer */
1589 serial_port_in(port, SCxSR);
1590 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1591 }
1592 } else {
1593 sci_handle_fifo_overrun(port);
1594 if (!s->chan_rx)
1595 sci_receive_chars(ptr);
1596 }
1597
1598 sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1599
1600 /* Kick the transmission */
1601 if (!s->chan_tx)
1602 sci_tx_interrupt(irq, ptr);
1603
1604 return IRQ_HANDLED;
1605 }
1606
1607 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1608 {
1609 struct uart_port *port = ptr;
1610
1611 /* Handle BREAKs */
1612 sci_handle_breaks(port);
1613 sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1614
1615 return IRQ_HANDLED;
1616 }
1617
1618 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1619 {
1620 unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1621 struct uart_port *port = ptr;
1622 struct sci_port *s = to_sci_port(port);
1623 irqreturn_t ret = IRQ_NONE;
1624
1625 ssr_status = serial_port_in(port, SCxSR);
1626 scr_status = serial_port_in(port, SCSCR);
1627 if (s->overrun_reg == SCxSR)
1628 orer_status = ssr_status;
1629 else {
1630 if (sci_getreg(port, s->overrun_reg)->size)
1631 orer_status = serial_port_in(port, s->overrun_reg);
1632 }
1633
1634 err_enabled = scr_status & port_rx_irq_mask(port);
1635
1636 /* Tx Interrupt */
1637 if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1638 !s->chan_tx)
1639 ret = sci_tx_interrupt(irq, ptr);
1640
1641 /*
1642 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1643 * DR flags
1644 */
1645 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1646 (scr_status & SCSCR_RIE))
1647 ret = sci_rx_interrupt(irq, ptr);
1648
1649 /* Error Interrupt */
1650 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1651 ret = sci_er_interrupt(irq, ptr);
1652
1653 /* Break Interrupt */
1654 if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1655 ret = sci_br_interrupt(irq, ptr);
1656
1657 /* Overrun Interrupt */
1658 if (orer_status & s->overrun_mask) {
1659 sci_handle_fifo_overrun(port);
1660 ret = IRQ_HANDLED;
1661 }
1662
1663 return ret;
1664 }
1665
1666 static const struct sci_irq_desc {
1667 const char *desc;
1668 irq_handler_t handler;
1669 } sci_irq_desc[] = {
1670 /*
1671 * Split out handlers, the default case.
1672 */
1673 [SCIx_ERI_IRQ] = {
1674 .desc = "rx err",
1675 .handler = sci_er_interrupt,
1676 },
1677
1678 [SCIx_RXI_IRQ] = {
1679 .desc = "rx full",
1680 .handler = sci_rx_interrupt,
1681 },
1682
1683 [SCIx_TXI_IRQ] = {
1684 .desc = "tx empty",
1685 .handler = sci_tx_interrupt,
1686 },
1687
1688 [SCIx_BRI_IRQ] = {
1689 .desc = "break",
1690 .handler = sci_br_interrupt,
1691 },
1692
1693 /*
1694 * Special muxed handler.
1695 */
1696 [SCIx_MUX_IRQ] = {
1697 .desc = "mux",
1698 .handler = sci_mpxed_interrupt,
1699 },
1700 };
1701
1702 static int sci_request_irq(struct sci_port *port)
1703 {
1704 struct uart_port *up = &port->port;
1705 int i, j, ret = 0;
1706
1707 for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1708 const struct sci_irq_desc *desc;
1709 int irq;
1710
1711 if (SCIx_IRQ_IS_MUXED(port)) {
1712 i = SCIx_MUX_IRQ;
1713 irq = up->irq;
1714 } else {
1715 irq = port->irqs[i];
1716
1717 /*
1718 * Certain port types won't support all of the
1719 * available interrupt sources.
1720 */
1721 if (unlikely(irq < 0))
1722 continue;
1723 }
1724
1725 desc = sci_irq_desc + i;
1726 port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1727 dev_name(up->dev), desc->desc);
1728 if (!port->irqstr[j])
1729 goto out_nomem;
1730
1731 ret = request_irq(irq, desc->handler, up->irqflags,
1732 port->irqstr[j], port);
1733 if (unlikely(ret)) {
1734 dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1735 goto out_noirq;
1736 }
1737 }
1738
1739 return 0;
1740
1741 out_noirq:
1742 while (--i >= 0)
1743 free_irq(port->irqs[i], port);
1744
1745 out_nomem:
1746 while (--j >= 0)
1747 kfree(port->irqstr[j]);
1748
1749 return ret;
1750 }
1751
1752 static void sci_free_irq(struct sci_port *port)
1753 {
1754 int i;
1755
1756 /*
1757 * Intentionally in reverse order so we iterate over the muxed
1758 * IRQ first.
1759 */
1760 for (i = 0; i < SCIx_NR_IRQS; i++) {
1761 int irq = port->irqs[i];
1762
1763 /*
1764 * Certain port types won't support all of the available
1765 * interrupt sources.
1766 */
1767 if (unlikely(irq < 0))
1768 continue;
1769
1770 free_irq(port->irqs[i], port);
1771 kfree(port->irqstr[i]);
1772
1773 if (SCIx_IRQ_IS_MUXED(port)) {
1774 /* If there's only one IRQ, we're done. */
1775 return;
1776 }
1777 }
1778 }
1779
1780 static unsigned int sci_tx_empty(struct uart_port *port)
1781 {
1782 unsigned short status = serial_port_in(port, SCxSR);
1783 unsigned short in_tx_fifo = sci_txfill(port);
1784
1785 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1786 }
1787
1788 /*
1789 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1790 * CTS/RTS is supported in hardware by at least one port and controlled
1791 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1792 * handled via the ->init_pins() op, which is a bit of a one-way street,
1793 * lacking any ability to defer pin control -- this will later be
1794 * converted over to the GPIO framework).
1795 *
1796 * Other modes (such as loopback) are supported generically on certain
1797 * port types, but not others. For these it's sufficient to test for the
1798 * existence of the support register and simply ignore the port type.
1799 */
1800 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1801 {
1802 if (mctrl & TIOCM_LOOP) {
1803 const struct plat_sci_reg *reg;
1804
1805 /*
1806 * Standard loopback mode for SCFCR ports.
1807 */
1808 reg = sci_getreg(port, SCFCR);
1809 if (reg->size)
1810 serial_port_out(port, SCFCR,
1811 serial_port_in(port, SCFCR) |
1812 SCFCR_LOOP);
1813 }
1814 }
1815
1816 static unsigned int sci_get_mctrl(struct uart_port *port)
1817 {
1818 /*
1819 * CTS/RTS is handled in hardware when supported, while nothing
1820 * else is wired up. Keep it simple and simply assert DSR/CAR.
1821 */
1822 return TIOCM_DSR | TIOCM_CAR;
1823 }
1824
1825 static void sci_break_ctl(struct uart_port *port, int break_state)
1826 {
1827 struct sci_port *s = to_sci_port(port);
1828 const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
1829 unsigned short scscr, scsptr;
1830
1831 /* check wheter the port has SCSPTR */
1832 if (!reg->size) {
1833 /*
1834 * Not supported by hardware. Most parts couple break and rx
1835 * interrupts together, with break detection always enabled.
1836 */
1837 return;
1838 }
1839
1840 scsptr = serial_port_in(port, SCSPTR);
1841 scscr = serial_port_in(port, SCSCR);
1842
1843 if (break_state == -1) {
1844 scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
1845 scscr &= ~SCSCR_TE;
1846 } else {
1847 scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
1848 scscr |= SCSCR_TE;
1849 }
1850
1851 serial_port_out(port, SCSPTR, scsptr);
1852 serial_port_out(port, SCSCR, scscr);
1853 }
1854
1855 static int sci_startup(struct uart_port *port)
1856 {
1857 struct sci_port *s = to_sci_port(port);
1858 unsigned long flags;
1859 int ret;
1860
1861 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1862
1863 ret = sci_request_irq(s);
1864 if (unlikely(ret < 0))
1865 return ret;
1866
1867 sci_request_dma(port);
1868
1869 spin_lock_irqsave(&port->lock, flags);
1870 sci_start_tx(port);
1871 sci_start_rx(port);
1872 spin_unlock_irqrestore(&port->lock, flags);
1873
1874 return 0;
1875 }
1876
1877 static void sci_shutdown(struct uart_port *port)
1878 {
1879 struct sci_port *s = to_sci_port(port);
1880 unsigned long flags;
1881
1882 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1883
1884 spin_lock_irqsave(&port->lock, flags);
1885 sci_stop_rx(port);
1886 sci_stop_tx(port);
1887 spin_unlock_irqrestore(&port->lock, flags);
1888
1889 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1890 if (s->chan_rx) {
1891 dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
1892 port->line);
1893 del_timer_sync(&s->rx_timer);
1894 }
1895 #endif
1896
1897 sci_free_dma(port);
1898 sci_free_irq(s);
1899 }
1900
1901 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
1902 unsigned int *srr)
1903 {
1904 unsigned long freq = s->clk_rates[SCI_SCK];
1905 unsigned int min_sr, max_sr, sr;
1906 int err, min_err = INT_MAX;
1907
1908 if (s->sampling_rate) {
1909 /* SCI(F) has a fixed sampling rate */
1910 min_sr = max_sr = s->sampling_rate / 2;
1911 } else {
1912 /* HSCIF has a variable 1/(8..32) sampling rate */
1913 min_sr = 8;
1914 max_sr = 32;
1915 }
1916
1917 for (sr = max_sr; sr >= min_sr; sr--) {
1918 err = DIV_ROUND_CLOSEST(freq, sr) - bps;
1919 if (abs(err) >= abs(min_err))
1920 continue;
1921
1922 min_err = err;
1923 *srr = sr - 1;
1924
1925 if (!err)
1926 break;
1927 }
1928
1929 dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
1930 *srr + 1);
1931 return min_err;
1932 }
1933
1934 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
1935 unsigned long freq, unsigned int *dlr,
1936 unsigned int *srr)
1937 {
1938 unsigned int min_sr, max_sr, sr, dl;
1939 int err, min_err = INT_MAX;
1940
1941 if (s->sampling_rate) {
1942 /* SCIF has a fixed sampling rate */
1943 min_sr = max_sr = s->sampling_rate / 2;
1944 } else {
1945 /* HSCIF has a variable 1/(8..32) sampling rate */
1946 min_sr = 8;
1947 max_sr = 32;
1948 }
1949
1950 for (sr = max_sr; sr >= min_sr; sr--) {
1951 dl = DIV_ROUND_CLOSEST(freq, sr * bps);
1952 dl = clamp(dl, 1U, 65535U);
1953
1954 err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
1955 if (abs(err) >= abs(min_err))
1956 continue;
1957
1958 min_err = err;
1959 *dlr = dl;
1960 *srr = sr - 1;
1961
1962 if (!err)
1963 break;
1964 }
1965
1966 dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
1967 min_err, *dlr, *srr + 1);
1968 return min_err;
1969 }
1970
1971 /* calculate sample rate, BRR, and clock select */
1972 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
1973 unsigned int *brr, unsigned int *srr,
1974 unsigned int *cks)
1975 {
1976 unsigned int min_sr, max_sr, shift, sr, br, prediv, scrate, c;
1977 unsigned long freq = s->clk_rates[SCI_FCK];
1978 int err, min_err = INT_MAX;
1979
1980 if (s->sampling_rate) {
1981 min_sr = max_sr = s->sampling_rate;
1982 shift = 0;
1983 } else {
1984 /* HSCIF has a variable sample rate */
1985 min_sr = 8;
1986 max_sr = 32;
1987 shift = 1;
1988 }
1989
1990 /*
1991 * Find the combination of sample rate and clock select with the
1992 * smallest deviation from the desired baud rate.
1993 * Prefer high sample rates to maximise the receive margin.
1994 *
1995 * M: Receive margin (%)
1996 * N: Ratio of bit rate to clock (N = sampling rate)
1997 * D: Clock duty (D = 0 to 1.0)
1998 * L: Frame length (L = 9 to 12)
1999 * F: Absolute value of clock frequency deviation
2000 *
2001 * M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2002 * (|D - 0.5| / N * (1 + F))|
2003 * NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2004 */
2005 for (sr = max_sr; sr >= min_sr; sr--) {
2006 for (c = 0; c <= 3; c++) {
2007 /* integerized formulas from HSCIF documentation */
2008 prediv = sr * (1 << (2 * c + shift));
2009
2010 /*
2011 * We need to calculate:
2012 *
2013 * br = freq / (prediv * bps) clamped to [1..256]
2014 * err = freq / (br * prediv) - bps
2015 *
2016 * Watch out for overflow when calculating the desired
2017 * sampling clock rate!
2018 */
2019 if (bps > UINT_MAX / prediv)
2020 break;
2021
2022 scrate = prediv * bps;
2023 br = DIV_ROUND_CLOSEST(freq, scrate);
2024 br = clamp(br, 1U, 256U);
2025
2026 err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2027 if (abs(err) >= abs(min_err))
2028 continue;
2029
2030 min_err = err;
2031 *brr = br - 1;
2032 *srr = sr - 1;
2033 *cks = c;
2034
2035 if (!err)
2036 goto found;
2037 }
2038 }
2039
2040 found:
2041 dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2042 min_err, *brr, *srr + 1, *cks);
2043 return min_err;
2044 }
2045
2046 static void sci_reset(struct uart_port *port)
2047 {
2048 const struct plat_sci_reg *reg;
2049 unsigned int status;
2050
2051 do {
2052 status = serial_port_in(port, SCxSR);
2053 } while (!(status & SCxSR_TEND(port)));
2054
2055 serial_port_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */
2056
2057 reg = sci_getreg(port, SCFCR);
2058 if (reg->size)
2059 serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2060 }
2061
2062 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2063 struct ktermios *old)
2064 {
2065 unsigned int baud, smr_val = 0, scr_val = 0, i;
2066 unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2067 unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2068 struct sci_port *s = to_sci_port(port);
2069 const struct plat_sci_reg *reg;
2070 int min_err = INT_MAX, err;
2071 unsigned long max_freq = 0;
2072 int best_clk = -1;
2073
2074 if ((termios->c_cflag & CSIZE) == CS7)
2075 smr_val |= SCSMR_CHR;
2076 if (termios->c_cflag & PARENB)
2077 smr_val |= SCSMR_PE;
2078 if (termios->c_cflag & PARODD)
2079 smr_val |= SCSMR_PE | SCSMR_ODD;
2080 if (termios->c_cflag & CSTOPB)
2081 smr_val |= SCSMR_STOP;
2082
2083 /*
2084 * earlyprintk comes here early on with port->uartclk set to zero.
2085 * the clock framework is not up and running at this point so here
2086 * we assume that 115200 is the maximum baud rate. please note that
2087 * the baud rate is not programmed during earlyprintk - it is assumed
2088 * that the previous boot loader has enabled required clocks and
2089 * setup the baud rate generator hardware for us already.
2090 */
2091 if (!port->uartclk) {
2092 baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2093 goto done;
2094 }
2095
2096 for (i = 0; i < SCI_NUM_CLKS; i++)
2097 max_freq = max(max_freq, s->clk_rates[i]);
2098
2099 baud = uart_get_baud_rate(port, termios, old, 0,
2100 max_freq / max(s->sampling_rate, 8U));
2101 if (!baud)
2102 goto done;
2103
2104 /*
2105 * There can be multiple sources for the sampling clock. Find the one
2106 * that gives us the smallest deviation from the desired baud rate.
2107 */
2108
2109 /* Optional Undivided External Clock */
2110 if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2111 port->type != PORT_SCIFB) {
2112 err = sci_sck_calc(s, baud, &srr1);
2113 if (abs(err) < abs(min_err)) {
2114 best_clk = SCI_SCK;
2115 scr_val = SCSCR_CKE1;
2116 sccks = SCCKS_CKS;
2117 min_err = err;
2118 srr = srr1;
2119 if (!err)
2120 goto done;
2121 }
2122 }
2123
2124 /* Optional BRG Frequency Divided External Clock */
2125 if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2126 err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2127 &srr1);
2128 if (abs(err) < abs(min_err)) {
2129 best_clk = SCI_SCIF_CLK;
2130 scr_val = SCSCR_CKE1;
2131 sccks = 0;
2132 min_err = err;
2133 dl = dl1;
2134 srr = srr1;
2135 if (!err)
2136 goto done;
2137 }
2138 }
2139
2140 /* Optional BRG Frequency Divided Internal Clock */
2141 if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2142 err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2143 &srr1);
2144 if (abs(err) < abs(min_err)) {
2145 best_clk = SCI_BRG_INT;
2146 scr_val = SCSCR_CKE1;
2147 sccks = SCCKS_XIN;
2148 min_err = err;
2149 dl = dl1;
2150 srr = srr1;
2151 if (!min_err)
2152 goto done;
2153 }
2154 }
2155
2156 /* Divided Functional Clock using standard Bit Rate Register */
2157 err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2158 if (abs(err) < abs(min_err)) {
2159 best_clk = SCI_FCK;
2160 scr_val = 0;
2161 min_err = err;
2162 brr = brr1;
2163 srr = srr1;
2164 cks = cks1;
2165 }
2166
2167 done:
2168 if (best_clk >= 0)
2169 dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2170 s->clks[best_clk], baud, min_err);
2171
2172 sci_port_enable(s);
2173
2174 /*
2175 * Program the optional External Baud Rate Generator (BRG) first.
2176 * It controls the mux to select (H)SCK or frequency divided clock.
2177 */
2178 if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2179 serial_port_out(port, SCDL, dl);
2180 serial_port_out(port, SCCKS, sccks);
2181 }
2182
2183 sci_reset(port);
2184
2185 uart_update_timeout(port, termios->c_cflag, baud);
2186
2187 if (best_clk >= 0) {
2188 smr_val |= cks;
2189 dev_dbg(port->dev,
2190 "SCR 0x%x SMR 0x%x BRR %u CKS 0x%x DL %u SRR %u\n",
2191 scr_val, smr_val, brr, sccks, dl, srr);
2192 serial_port_out(port, SCSCR, scr_val);
2193 serial_port_out(port, SCSMR, smr_val);
2194 serial_port_out(port, SCBRR, brr);
2195 if (sci_getreg(port, HSSRR)->size)
2196 serial_port_out(port, HSSRR, srr | HSCIF_SRE);
2197
2198 /* Wait one bit interval */
2199 udelay((1000000 + (baud - 1)) / baud);
2200 } else {
2201 /* Don't touch the bit rate configuration */
2202 scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2203 smr_val |= serial_port_in(port, SCSMR) & SCSMR_CKS;
2204 dev_dbg(port->dev, "SCR 0x%x SMR 0x%x\n", scr_val, smr_val);
2205 serial_port_out(port, SCSCR, scr_val);
2206 serial_port_out(port, SCSMR, smr_val);
2207 }
2208
2209 sci_init_pins(port, termios->c_cflag);
2210
2211 reg = sci_getreg(port, SCFCR);
2212 if (reg->size) {
2213 unsigned short ctrl = serial_port_in(port, SCFCR);
2214
2215 if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) {
2216 if (termios->c_cflag & CRTSCTS)
2217 ctrl |= SCFCR_MCE;
2218 else
2219 ctrl &= ~SCFCR_MCE;
2220 }
2221
2222 /*
2223 * As we've done a sci_reset() above, ensure we don't
2224 * interfere with the FIFOs while toggling MCE. As the
2225 * reset values could still be set, simply mask them out.
2226 */
2227 ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2228
2229 serial_port_out(port, SCFCR, ctrl);
2230 }
2231
2232 scr_val |= s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0);
2233 dev_dbg(port->dev, "SCSCR 0x%x\n", scr_val);
2234 serial_port_out(port, SCSCR, scr_val);
2235
2236 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2237 /*
2238 * Calculate delay for 2 DMA buffers (4 FIFO).
2239 * See serial_core.c::uart_update_timeout().
2240 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2241 * function calculates 1 jiffie for the data plus 5 jiffies for the
2242 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2243 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2244 * value obtained by this formula is too small. Therefore, if the value
2245 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2246 */
2247 if (s->chan_rx) {
2248 unsigned int bits;
2249
2250 /* byte size and parity */
2251 switch (termios->c_cflag & CSIZE) {
2252 case CS5:
2253 bits = 7;
2254 break;
2255 case CS6:
2256 bits = 8;
2257 break;
2258 case CS7:
2259 bits = 9;
2260 break;
2261 default:
2262 bits = 10;
2263 break;
2264 }
2265
2266 if (termios->c_cflag & CSTOPB)
2267 bits++;
2268 if (termios->c_cflag & PARENB)
2269 bits++;
2270 s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
2271 (baud / 10), 10);
2272 dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n",
2273 s->rx_timeout * 1000 / HZ, port->timeout);
2274 if (s->rx_timeout < msecs_to_jiffies(20))
2275 s->rx_timeout = msecs_to_jiffies(20);
2276 }
2277 #endif
2278
2279 if ((termios->c_cflag & CREAD) != 0)
2280 sci_start_rx(port);
2281
2282 sci_port_disable(s);
2283 }
2284
2285 static void sci_pm(struct uart_port *port, unsigned int state,
2286 unsigned int oldstate)
2287 {
2288 struct sci_port *sci_port = to_sci_port(port);
2289
2290 switch (state) {
2291 case UART_PM_STATE_OFF:
2292 sci_port_disable(sci_port);
2293 break;
2294 default:
2295 sci_port_enable(sci_port);
2296 break;
2297 }
2298 }
2299
2300 static const char *sci_type(struct uart_port *port)
2301 {
2302 switch (port->type) {
2303 case PORT_IRDA:
2304 return "irda";
2305 case PORT_SCI:
2306 return "sci";
2307 case PORT_SCIF:
2308 return "scif";
2309 case PORT_SCIFA:
2310 return "scifa";
2311 case PORT_SCIFB:
2312 return "scifb";
2313 case PORT_HSCIF:
2314 return "hscif";
2315 }
2316
2317 return NULL;
2318 }
2319
2320 static int sci_remap_port(struct uart_port *port)
2321 {
2322 struct sci_port *sport = to_sci_port(port);
2323
2324 /*
2325 * Nothing to do if there's already an established membase.
2326 */
2327 if (port->membase)
2328 return 0;
2329
2330 if (port->flags & UPF_IOREMAP) {
2331 port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2332 if (unlikely(!port->membase)) {
2333 dev_err(port->dev, "can't remap port#%d\n", port->line);
2334 return -ENXIO;
2335 }
2336 } else {
2337 /*
2338 * For the simple (and majority of) cases where we don't
2339 * need to do any remapping, just cast the cookie
2340 * directly.
2341 */
2342 port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2343 }
2344
2345 return 0;
2346 }
2347
2348 static void sci_release_port(struct uart_port *port)
2349 {
2350 struct sci_port *sport = to_sci_port(port);
2351
2352 if (port->flags & UPF_IOREMAP) {
2353 iounmap(port->membase);
2354 port->membase = NULL;
2355 }
2356
2357 release_mem_region(port->mapbase, sport->reg_size);
2358 }
2359
2360 static int sci_request_port(struct uart_port *port)
2361 {
2362 struct resource *res;
2363 struct sci_port *sport = to_sci_port(port);
2364 int ret;
2365
2366 res = request_mem_region(port->mapbase, sport->reg_size,
2367 dev_name(port->dev));
2368 if (unlikely(res == NULL)) {
2369 dev_err(port->dev, "request_mem_region failed.");
2370 return -EBUSY;
2371 }
2372
2373 ret = sci_remap_port(port);
2374 if (unlikely(ret != 0)) {
2375 release_resource(res);
2376 return ret;
2377 }
2378
2379 return 0;
2380 }
2381
2382 static void sci_config_port(struct uart_port *port, int flags)
2383 {
2384 if (flags & UART_CONFIG_TYPE) {
2385 struct sci_port *sport = to_sci_port(port);
2386
2387 port->type = sport->cfg->type;
2388 sci_request_port(port);
2389 }
2390 }
2391
2392 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2393 {
2394 if (ser->baud_base < 2400)
2395 /* No paper tape reader for Mitch.. */
2396 return -EINVAL;
2397
2398 return 0;
2399 }
2400
2401 static struct uart_ops sci_uart_ops = {
2402 .tx_empty = sci_tx_empty,
2403 .set_mctrl = sci_set_mctrl,
2404 .get_mctrl = sci_get_mctrl,
2405 .start_tx = sci_start_tx,
2406 .stop_tx = sci_stop_tx,
2407 .stop_rx = sci_stop_rx,
2408 .break_ctl = sci_break_ctl,
2409 .startup = sci_startup,
2410 .shutdown = sci_shutdown,
2411 .set_termios = sci_set_termios,
2412 .pm = sci_pm,
2413 .type = sci_type,
2414 .release_port = sci_release_port,
2415 .request_port = sci_request_port,
2416 .config_port = sci_config_port,
2417 .verify_port = sci_verify_port,
2418 #ifdef CONFIG_CONSOLE_POLL
2419 .poll_get_char = sci_poll_get_char,
2420 .poll_put_char = sci_poll_put_char,
2421 #endif
2422 };
2423
2424 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2425 {
2426 const char *clk_names[] = {
2427 [SCI_FCK] = "fck",
2428 [SCI_SCK] = "sck",
2429 [SCI_BRG_INT] = "brg_int",
2430 [SCI_SCIF_CLK] = "scif_clk",
2431 };
2432 struct clk *clk;
2433 unsigned int i;
2434
2435 if (sci_port->cfg->type == PORT_HSCIF)
2436 clk_names[SCI_SCK] = "hsck";
2437
2438 for (i = 0; i < SCI_NUM_CLKS; i++) {
2439 clk = devm_clk_get(dev, clk_names[i]);
2440 if (PTR_ERR(clk) == -EPROBE_DEFER)
2441 return -EPROBE_DEFER;
2442
2443 if (IS_ERR(clk) && i == SCI_FCK) {
2444 /*
2445 * "fck" used to be called "sci_ick", and we need to
2446 * maintain DT backward compatibility.
2447 */
2448 clk = devm_clk_get(dev, "sci_ick");
2449 if (PTR_ERR(clk) == -EPROBE_DEFER)
2450 return -EPROBE_DEFER;
2451
2452 if (!IS_ERR(clk))
2453 goto found;
2454
2455 /*
2456 * Not all SH platforms declare a clock lookup entry
2457 * for SCI devices, in which case we need to get the
2458 * global "peripheral_clk" clock.
2459 */
2460 clk = devm_clk_get(dev, "peripheral_clk");
2461 if (!IS_ERR(clk))
2462 goto found;
2463
2464 dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2465 PTR_ERR(clk));
2466 return PTR_ERR(clk);
2467 }
2468
2469 found:
2470 if (IS_ERR(clk))
2471 dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2472 PTR_ERR(clk));
2473 else
2474 dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
2475 clk, clk);
2476 sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2477 }
2478 return 0;
2479 }
2480
2481 static int sci_init_single(struct platform_device *dev,
2482 struct sci_port *sci_port, unsigned int index,
2483 struct plat_sci_port *p, bool early)
2484 {
2485 struct uart_port *port = &sci_port->port;
2486 const struct resource *res;
2487 unsigned int i;
2488 int ret;
2489
2490 sci_port->cfg = p;
2491
2492 port->ops = &sci_uart_ops;
2493 port->iotype = UPIO_MEM;
2494 port->line = index;
2495
2496 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2497 if (res == NULL)
2498 return -ENOMEM;
2499
2500 port->mapbase = res->start;
2501 sci_port->reg_size = resource_size(res);
2502
2503 for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2504 sci_port->irqs[i] = platform_get_irq(dev, i);
2505
2506 /* The SCI generates several interrupts. They can be muxed together or
2507 * connected to different interrupt lines. In the muxed case only one
2508 * interrupt resource is specified. In the non-muxed case three or four
2509 * interrupt resources are specified, as the BRI interrupt is optional.
2510 */
2511 if (sci_port->irqs[0] < 0)
2512 return -ENXIO;
2513
2514 if (sci_port->irqs[1] < 0) {
2515 sci_port->irqs[1] = sci_port->irqs[0];
2516 sci_port->irqs[2] = sci_port->irqs[0];
2517 sci_port->irqs[3] = sci_port->irqs[0];
2518 }
2519
2520 if (p->regtype == SCIx_PROBE_REGTYPE) {
2521 ret = sci_probe_regmap(p);
2522 if (unlikely(ret))
2523 return ret;
2524 }
2525
2526 switch (p->type) {
2527 case PORT_SCIFB:
2528 port->fifosize = 256;
2529 sci_port->overrun_reg = SCxSR;
2530 sci_port->overrun_mask = SCIFA_ORER;
2531 sci_port->sampling_rate = 16;
2532 break;
2533 case PORT_HSCIF:
2534 port->fifosize = 128;
2535 sci_port->overrun_reg = SCLSR;
2536 sci_port->overrun_mask = SCLSR_ORER;
2537 sci_port->sampling_rate = 0;
2538 break;
2539 case PORT_SCIFA:
2540 port->fifosize = 64;
2541 sci_port->overrun_reg = SCxSR;
2542 sci_port->overrun_mask = SCIFA_ORER;
2543 sci_port->sampling_rate = 16;
2544 break;
2545 case PORT_SCIF:
2546 port->fifosize = 16;
2547 if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) {
2548 sci_port->overrun_reg = SCxSR;
2549 sci_port->overrun_mask = SCIFA_ORER;
2550 sci_port->sampling_rate = 16;
2551 } else {
2552 sci_port->overrun_reg = SCLSR;
2553 sci_port->overrun_mask = SCLSR_ORER;
2554 sci_port->sampling_rate = 32;
2555 }
2556 break;
2557 default:
2558 port->fifosize = 1;
2559 sci_port->overrun_reg = SCxSR;
2560 sci_port->overrun_mask = SCI_ORER;
2561 sci_port->sampling_rate = 32;
2562 break;
2563 }
2564
2565 /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2566 * match the SoC datasheet, this should be investigated. Let platform
2567 * data override the sampling rate for now.
2568 */
2569 if (p->sampling_rate)
2570 sci_port->sampling_rate = p->sampling_rate;
2571
2572 if (!early) {
2573 ret = sci_init_clocks(sci_port, &dev->dev);
2574 if (ret < 0)
2575 return ret;
2576
2577 port->dev = &dev->dev;
2578
2579 pm_runtime_enable(&dev->dev);
2580 }
2581
2582 sci_port->break_timer.data = (unsigned long)sci_port;
2583 sci_port->break_timer.function = sci_break_timer;
2584 init_timer(&sci_port->break_timer);
2585
2586 /*
2587 * Establish some sensible defaults for the error detection.
2588 */
2589 if (p->type == PORT_SCI) {
2590 sci_port->error_mask = SCI_DEFAULT_ERROR_MASK;
2591 sci_port->error_clear = SCI_ERROR_CLEAR;
2592 } else {
2593 sci_port->error_mask = SCIF_DEFAULT_ERROR_MASK;
2594 sci_port->error_clear = SCIF_ERROR_CLEAR;
2595 }
2596
2597 /*
2598 * Make the error mask inclusive of overrun detection, if
2599 * supported.
2600 */
2601 if (sci_port->overrun_reg == SCxSR) {
2602 sci_port->error_mask |= sci_port->overrun_mask;
2603 sci_port->error_clear &= ~sci_port->overrun_mask;
2604 }
2605
2606 port->type = p->type;
2607 port->flags = UPF_FIXED_PORT | p->flags;
2608 port->regshift = p->regshift;
2609
2610 /*
2611 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2612 * for the multi-IRQ ports, which is where we are primarily
2613 * concerned with the shutdown path synchronization.
2614 *
2615 * For the muxed case there's nothing more to do.
2616 */
2617 port->irq = sci_port->irqs[SCIx_RXI_IRQ];
2618 port->irqflags = 0;
2619
2620 port->serial_in = sci_serial_in;
2621 port->serial_out = sci_serial_out;
2622
2623 if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
2624 dev_dbg(port->dev, "DMA tx %d, rx %d\n",
2625 p->dma_slave_tx, p->dma_slave_rx);
2626
2627 return 0;
2628 }
2629
2630 static void sci_cleanup_single(struct sci_port *port)
2631 {
2632 pm_runtime_disable(port->port.dev);
2633 }
2634
2635 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2636 static void serial_console_putchar(struct uart_port *port, int ch)
2637 {
2638 sci_poll_put_char(port, ch);
2639 }
2640
2641 /*
2642 * Print a string to the serial port trying not to disturb
2643 * any possible real use of the port...
2644 */
2645 static void serial_console_write(struct console *co, const char *s,
2646 unsigned count)
2647 {
2648 struct sci_port *sci_port = &sci_ports[co->index];
2649 struct uart_port *port = &sci_port->port;
2650 unsigned short bits, ctrl, ctrl_temp;
2651 unsigned long flags;
2652 int locked = 1;
2653
2654 local_irq_save(flags);
2655 if (port->sysrq)
2656 locked = 0;
2657 else if (oops_in_progress)
2658 locked = spin_trylock(&port->lock);
2659 else
2660 spin_lock(&port->lock);
2661
2662 /* first save SCSCR then disable interrupts, keep clock source */
2663 ctrl = serial_port_in(port, SCSCR);
2664 ctrl_temp = (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2665 (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2666 serial_port_out(port, SCSCR, ctrl_temp);
2667
2668 uart_console_write(port, s, count, serial_console_putchar);
2669
2670 /* wait until fifo is empty and last bit has been transmitted */
2671 bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2672 while ((serial_port_in(port, SCxSR) & bits) != bits)
2673 cpu_relax();
2674
2675 /* restore the SCSCR */
2676 serial_port_out(port, SCSCR, ctrl);
2677
2678 if (locked)
2679 spin_unlock(&port->lock);
2680 local_irq_restore(flags);
2681 }
2682
2683 static int serial_console_setup(struct console *co, char *options)
2684 {
2685 struct sci_port *sci_port;
2686 struct uart_port *port;
2687 int baud = 115200;
2688 int bits = 8;
2689 int parity = 'n';
2690 int flow = 'n';
2691 int ret;
2692
2693 /*
2694 * Refuse to handle any bogus ports.
2695 */
2696 if (co->index < 0 || co->index >= SCI_NPORTS)
2697 return -ENODEV;
2698
2699 sci_port = &sci_ports[co->index];
2700 port = &sci_port->port;
2701
2702 /*
2703 * Refuse to handle uninitialized ports.
2704 */
2705 if (!port->ops)
2706 return -ENODEV;
2707
2708 ret = sci_remap_port(port);
2709 if (unlikely(ret != 0))
2710 return ret;
2711
2712 if (options)
2713 uart_parse_options(options, &baud, &parity, &bits, &flow);
2714
2715 return uart_set_options(port, co, baud, parity, bits, flow);
2716 }
2717
2718 static struct console serial_console = {
2719 .name = "ttySC",
2720 .device = uart_console_device,
2721 .write = serial_console_write,
2722 .setup = serial_console_setup,
2723 .flags = CON_PRINTBUFFER,
2724 .index = -1,
2725 .data = &sci_uart_driver,
2726 };
2727
2728 static struct console early_serial_console = {
2729 .name = "early_ttySC",
2730 .write = serial_console_write,
2731 .flags = CON_PRINTBUFFER,
2732 .index = -1,
2733 };
2734
2735 static char early_serial_buf[32];
2736
2737 static int sci_probe_earlyprintk(struct platform_device *pdev)
2738 {
2739 struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
2740
2741 if (early_serial_console.data)
2742 return -EEXIST;
2743
2744 early_serial_console.index = pdev->id;
2745
2746 sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
2747
2748 serial_console_setup(&early_serial_console, early_serial_buf);
2749
2750 if (!strstr(early_serial_buf, "keep"))
2751 early_serial_console.flags |= CON_BOOT;
2752
2753 register_console(&early_serial_console);
2754 return 0;
2755 }
2756
2757 #define SCI_CONSOLE (&serial_console)
2758
2759 #else
2760 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
2761 {
2762 return -EINVAL;
2763 }
2764
2765 #define SCI_CONSOLE NULL
2766
2767 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
2768
2769 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
2770
2771 static struct uart_driver sci_uart_driver = {
2772 .owner = THIS_MODULE,
2773 .driver_name = "sci",
2774 .dev_name = "ttySC",
2775 .major = SCI_MAJOR,
2776 .minor = SCI_MINOR_START,
2777 .nr = SCI_NPORTS,
2778 .cons = SCI_CONSOLE,
2779 };
2780
2781 static int sci_remove(struct platform_device *dev)
2782 {
2783 struct sci_port *port = platform_get_drvdata(dev);
2784
2785 uart_remove_one_port(&sci_uart_driver, &port->port);
2786
2787 sci_cleanup_single(port);
2788
2789 return 0;
2790 }
2791
2792
2793 #define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
2794 #define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
2795 #define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
2796
2797 static const struct of_device_id of_sci_match[] = {
2798 /* SoC-specific types */
2799 {
2800 .compatible = "renesas,scif-r7s72100",
2801 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
2802 },
2803 /* Family-specific types */
2804 {
2805 .compatible = "renesas,rcar-gen1-scif",
2806 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2807 }, {
2808 .compatible = "renesas,rcar-gen2-scif",
2809 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2810 }, {
2811 .compatible = "renesas,rcar-gen3-scif",
2812 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2813 },
2814 /* Generic types */
2815 {
2816 .compatible = "renesas,scif",
2817 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
2818 }, {
2819 .compatible = "renesas,scifa",
2820 .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
2821 }, {
2822 .compatible = "renesas,scifb",
2823 .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
2824 }, {
2825 .compatible = "renesas,hscif",
2826 .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
2827 }, {
2828 .compatible = "renesas,sci",
2829 .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
2830 }, {
2831 /* Terminator */
2832 },
2833 };
2834 MODULE_DEVICE_TABLE(of, of_sci_match);
2835
2836 static struct plat_sci_port *
2837 sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id)
2838 {
2839 struct device_node *np = pdev->dev.of_node;
2840 const struct of_device_id *match;
2841 struct plat_sci_port *p;
2842 int id;
2843
2844 if (!IS_ENABLED(CONFIG_OF) || !np)
2845 return NULL;
2846
2847 match = of_match_node(of_sci_match, np);
2848 if (!match)
2849 return NULL;
2850
2851 p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
2852 if (!p)
2853 return NULL;
2854
2855 /* Get the line number from the aliases node. */
2856 id = of_alias_get_id(np, "serial");
2857 if (id < 0) {
2858 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
2859 return NULL;
2860 }
2861
2862 *dev_id = id;
2863
2864 p->flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
2865 p->type = SCI_OF_TYPE(match->data);
2866 p->regtype = SCI_OF_REGTYPE(match->data);
2867 p->scscr = SCSCR_RE | SCSCR_TE;
2868
2869 return p;
2870 }
2871
2872 static int sci_probe_single(struct platform_device *dev,
2873 unsigned int index,
2874 struct plat_sci_port *p,
2875 struct sci_port *sciport)
2876 {
2877 int ret;
2878
2879 /* Sanity check */
2880 if (unlikely(index >= SCI_NPORTS)) {
2881 dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
2882 index+1, SCI_NPORTS);
2883 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
2884 return -EINVAL;
2885 }
2886
2887 ret = sci_init_single(dev, sciport, index, p, false);
2888 if (ret)
2889 return ret;
2890
2891 ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
2892 if (ret) {
2893 sci_cleanup_single(sciport);
2894 return ret;
2895 }
2896
2897 return 0;
2898 }
2899
2900 static int sci_probe(struct platform_device *dev)
2901 {
2902 struct plat_sci_port *p;
2903 struct sci_port *sp;
2904 unsigned int dev_id;
2905 int ret;
2906
2907 /*
2908 * If we've come here via earlyprintk initialization, head off to
2909 * the special early probe. We don't have sufficient device state
2910 * to make it beyond this yet.
2911 */
2912 if (is_early_platform_device(dev))
2913 return sci_probe_earlyprintk(dev);
2914
2915 if (dev->dev.of_node) {
2916 p = sci_parse_dt(dev, &dev_id);
2917 if (p == NULL)
2918 return -EINVAL;
2919 } else {
2920 p = dev->dev.platform_data;
2921 if (p == NULL) {
2922 dev_err(&dev->dev, "no platform data supplied\n");
2923 return -EINVAL;
2924 }
2925
2926 dev_id = dev->id;
2927 }
2928
2929 sp = &sci_ports[dev_id];
2930 platform_set_drvdata(dev, sp);
2931
2932 ret = sci_probe_single(dev, dev_id, p, sp);
2933 if (ret)
2934 return ret;
2935
2936 #ifdef CONFIG_SH_STANDARD_BIOS
2937 sh_bios_gdb_detach();
2938 #endif
2939
2940 return 0;
2941 }
2942
2943 static __maybe_unused int sci_suspend(struct device *dev)
2944 {
2945 struct sci_port *sport = dev_get_drvdata(dev);
2946
2947 if (sport)
2948 uart_suspend_port(&sci_uart_driver, &sport->port);
2949
2950 return 0;
2951 }
2952
2953 static __maybe_unused int sci_resume(struct device *dev)
2954 {
2955 struct sci_port *sport = dev_get_drvdata(dev);
2956
2957 if (sport)
2958 uart_resume_port(&sci_uart_driver, &sport->port);
2959
2960 return 0;
2961 }
2962
2963 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
2964
2965 static struct platform_driver sci_driver = {
2966 .probe = sci_probe,
2967 .remove = sci_remove,
2968 .driver = {
2969 .name = "sh-sci",
2970 .pm = &sci_dev_pm_ops,
2971 .of_match_table = of_match_ptr(of_sci_match),
2972 },
2973 };
2974
2975 static int __init sci_init(void)
2976 {
2977 int ret;
2978
2979 pr_info("%s\n", banner);
2980
2981 ret = uart_register_driver(&sci_uart_driver);
2982 if (likely(ret == 0)) {
2983 ret = platform_driver_register(&sci_driver);
2984 if (unlikely(ret))
2985 uart_unregister_driver(&sci_uart_driver);
2986 }
2987
2988 return ret;
2989 }
2990
2991 static void __exit sci_exit(void)
2992 {
2993 platform_driver_unregister(&sci_driver);
2994 uart_unregister_driver(&sci_uart_driver);
2995 }
2996
2997 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2998 early_platform_init_buffer("earlyprintk", &sci_driver,
2999 early_serial_buf, ARRAY_SIZE(early_serial_buf));
3000 #endif
3001 module_init(sci_init);
3002 module_exit(sci_exit);
3003
3004 MODULE_LICENSE("GPL");
3005 MODULE_ALIAS("platform:sh-sci");
3006 MODULE_AUTHOR("Paul Mundt");
3007 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
Linux kernel - Deliverables
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