1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
4 *
5 * Copyright (C) 2002 - 2011 Paul Mundt
6 * Copyright (C) 2015 Glider bvba
7 * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8 *
9 * based off of the old drivers/char/sh-sci.c by:
10 *
11 * Copyright (C) 1999, 2000 Niibe Yutaka
12 * Copyright (C) 2000 Sugioka Toshinobu
13 * Modified to support multiple serial ports. Stuart Menefy (May 2000).
14 * Modified to support SecureEdge. David McCullough (2002)
15 * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16 * Removed SH7300 support (Jul 2007).
17 */
18 #undef DEBUG
19
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/module.h>
35 #include <linux/mm.h>
36 #include <linux/of.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm_runtime.h>
40 #include <linux/scatterlist.h>
41 #include <linux/serial.h>
42 #include <linux/serial_sci.h>
43 #include <linux/sh_dma.h>
44 #include <linux/slab.h>
45 #include <linux/string.h>
46 #include <linux/sysrq.h>
47 #include <linux/timer.h>
48 #include <linux/tty.h>
49 #include <linux/tty_flip.h>
50
51 #ifdef CONFIG_SUPERH
52 #include <asm/sh_bios.h>
53 #include <asm/platform_early.h>
54 #endif
55
56 #include "serial_mctrl_gpio.h"
57 #include "sh-sci.h"
58
59 /* Offsets into the sci_port->irqs array */
60 enum {
61 SCIx_ERI_IRQ,
62 SCIx_RXI_IRQ,
63 SCIx_TXI_IRQ,
64 SCIx_BRI_IRQ,
65 SCIx_DRI_IRQ,
66 SCIx_TEI_IRQ,
67 SCIx_NR_IRQS,
68
69 SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */
70 };
71
72 #define SCIx_IRQ_IS_MUXED(port) \
73 ((port)->irqs[SCIx_ERI_IRQ] == \
74 (port)->irqs[SCIx_RXI_IRQ]) || \
75 ((port)->irqs[SCIx_ERI_IRQ] && \
76 ((port)->irqs[SCIx_RXI_IRQ] < 0))
77
78 enum SCI_CLKS {
79 SCI_FCK, /* Functional Clock */
80 SCI_SCK, /* Optional External Clock */
81 SCI_BRG_INT, /* Optional BRG Internal Clock Source */
82 SCI_SCIF_CLK, /* Optional BRG External Clock Source */
83 SCI_NUM_CLKS
84 };
85
86 /* Bit x set means sampling rate x + 1 is supported */
87 #define SCI_SR(x) BIT((x) - 1)
88 #define SCI_SR_RANGE(x, y) GENMASK((y) - 1, (x) - 1)
89
90 #define SCI_SR_SCIFAB SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
91 SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
92 SCI_SR(19) | SCI_SR(27)
93
94 #define min_sr(_port) ffs((_port)->sampling_rate_mask)
95 #define max_sr(_port) fls((_port)->sampling_rate_mask)
96
97 /* Iterate over all supported sampling rates, from high to low */
98 #define for_each_sr(_sr, _port) \
99 for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--) \
100 if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
101
102 struct plat_sci_reg {
103 u8 offset, size;
104 };
105
106 struct sci_port_params {
107 const struct plat_sci_reg regs[SCIx_NR_REGS];
108 unsigned int fifosize;
109 unsigned int overrun_reg;
110 unsigned int overrun_mask;
111 unsigned int sampling_rate_mask;
112 unsigned int error_mask;
113 unsigned int error_clear;
114 };
115
116 struct sci_port {
117 struct uart_port port;
118
119 /* Platform configuration */
120 const struct sci_port_params *params;
121 const struct plat_sci_port *cfg;
122 unsigned int sampling_rate_mask;
123 resource_size_t reg_size;
124 struct mctrl_gpios *gpios;
125
126 /* Clocks */
127 struct clk *clks[SCI_NUM_CLKS];
128 unsigned long clk_rates[SCI_NUM_CLKS];
129
130 int irqs[SCIx_NR_IRQS];
131 char *irqstr[SCIx_NR_IRQS];
132
133 struct dma_chan *chan_tx;
134 struct dma_chan *chan_rx;
135
136 #ifdef CONFIG_SERIAL_SH_SCI_DMA
137 struct dma_chan *chan_tx_saved;
138 struct dma_chan *chan_rx_saved;
139 dma_cookie_t cookie_tx;
140 dma_cookie_t cookie_rx[2];
141 dma_cookie_t active_rx;
142 dma_addr_t tx_dma_addr;
143 unsigned int tx_dma_len;
144 struct scatterlist sg_rx[2];
145 void *rx_buf[2];
146 size_t buf_len_rx;
147 struct work_struct work_tx;
148 struct hrtimer rx_timer;
149 unsigned int rx_timeout; /* microseconds */
150 #endif
151 unsigned int rx_frame;
152 int rx_trigger;
153 struct timer_list rx_fifo_timer;
154 int rx_fifo_timeout;
155 u16 hscif_tot;
156
157 bool has_rtscts;
158 bool autorts;
159 };
160
161 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
162
163 static struct sci_port sci_ports[SCI_NPORTS];
164 static unsigned long sci_ports_in_use;
165 static struct uart_driver sci_uart_driver;
166
167 static inline struct sci_port *
to_sci_port(struct uart_port * uart)168 to_sci_port(struct uart_port *uart)
169 {
170 return container_of(uart, struct sci_port, port);
171 }
172
173 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
174 /*
175 * Common SCI definitions, dependent on the port's regshift
176 * value.
177 */
178 [SCIx_SCI_REGTYPE] = {
179 .regs = {
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 },
187 .fifosize = 1,
188 .overrun_reg = SCxSR,
189 .overrun_mask = SCI_ORER,
190 .sampling_rate_mask = SCI_SR(32),
191 .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
192 .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
193 },
194
195 /*
196 * Common definitions for legacy IrDA ports.
197 */
198 [SCIx_IRDA_REGTYPE] = {
199 .regs = {
200 [SCSMR] = { 0x00, 8 },
201 [SCBRR] = { 0x02, 8 },
202 [SCSCR] = { 0x04, 8 },
203 [SCxTDR] = { 0x06, 8 },
204 [SCxSR] = { 0x08, 16 },
205 [SCxRDR] = { 0x0a, 8 },
206 [SCFCR] = { 0x0c, 8 },
207 [SCFDR] = { 0x0e, 16 },
208 },
209 .fifosize = 1,
210 .overrun_reg = SCxSR,
211 .overrun_mask = SCI_ORER,
212 .sampling_rate_mask = SCI_SR(32),
213 .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
214 .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
215 },
216
217 /*
218 * Common SCIFA definitions.
219 */
220 [SCIx_SCIFA_REGTYPE] = {
221 .regs = {
222 [SCSMR] = { 0x00, 16 },
223 [SCBRR] = { 0x04, 8 },
224 [SCSCR] = { 0x08, 16 },
225 [SCxTDR] = { 0x20, 8 },
226 [SCxSR] = { 0x14, 16 },
227 [SCxRDR] = { 0x24, 8 },
228 [SCFCR] = { 0x18, 16 },
229 [SCFDR] = { 0x1c, 16 },
230 [SCPCR] = { 0x30, 16 },
231 [SCPDR] = { 0x34, 16 },
232 },
233 .fifosize = 64,
234 .overrun_reg = SCxSR,
235 .overrun_mask = SCIFA_ORER,
236 .sampling_rate_mask = SCI_SR_SCIFAB,
237 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
238 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
239 },
240
241 /*
242 * Common SCIFB definitions.
243 */
244 [SCIx_SCIFB_REGTYPE] = {
245 .regs = {
246 [SCSMR] = { 0x00, 16 },
247 [SCBRR] = { 0x04, 8 },
248 [SCSCR] = { 0x08, 16 },
249 [SCxTDR] = { 0x40, 8 },
250 [SCxSR] = { 0x14, 16 },
251 [SCxRDR] = { 0x60, 8 },
252 [SCFCR] = { 0x18, 16 },
253 [SCTFDR] = { 0x38, 16 },
254 [SCRFDR] = { 0x3c, 16 },
255 [SCPCR] = { 0x30, 16 },
256 [SCPDR] = { 0x34, 16 },
257 },
258 .fifosize = 256,
259 .overrun_reg = SCxSR,
260 .overrun_mask = SCIFA_ORER,
261 .sampling_rate_mask = SCI_SR_SCIFAB,
262 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
263 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
264 },
265
266 /*
267 * Common SH-2(A) SCIF definitions for ports with FIFO data
268 * count registers.
269 */
270 [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
271 .regs = {
272 [SCSMR] = { 0x00, 16 },
273 [SCBRR] = { 0x04, 8 },
274 [SCSCR] = { 0x08, 16 },
275 [SCxTDR] = { 0x0c, 8 },
276 [SCxSR] = { 0x10, 16 },
277 [SCxRDR] = { 0x14, 8 },
278 [SCFCR] = { 0x18, 16 },
279 [SCFDR] = { 0x1c, 16 },
280 [SCSPTR] = { 0x20, 16 },
281 [SCLSR] = { 0x24, 16 },
282 },
283 .fifosize = 16,
284 .overrun_reg = SCLSR,
285 .overrun_mask = SCLSR_ORER,
286 .sampling_rate_mask = SCI_SR(32),
287 .error_mask = SCIF_DEFAULT_ERROR_MASK,
288 .error_clear = SCIF_ERROR_CLEAR,
289 },
290
291 /*
292 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
293 * It looks like a normal SCIF with FIFO data, but with a
294 * compressed address space. Also, the break out of interrupts
295 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
296 */
297 [SCIx_RZ_SCIFA_REGTYPE] = {
298 .regs = {
299 [SCSMR] = { 0x00, 16 },
300 [SCBRR] = { 0x02, 8 },
301 [SCSCR] = { 0x04, 16 },
302 [SCxTDR] = { 0x06, 8 },
303 [SCxSR] = { 0x08, 16 },
304 [SCxRDR] = { 0x0A, 8 },
305 [SCFCR] = { 0x0C, 16 },
306 [SCFDR] = { 0x0E, 16 },
307 [SCSPTR] = { 0x10, 16 },
308 [SCLSR] = { 0x12, 16 },
309 [SEMR] = { 0x14, 8 },
310 },
311 .fifosize = 16,
312 .overrun_reg = SCLSR,
313 .overrun_mask = SCLSR_ORER,
314 .sampling_rate_mask = SCI_SR(32),
315 .error_mask = SCIF_DEFAULT_ERROR_MASK,
316 .error_clear = SCIF_ERROR_CLEAR,
317 },
318
319 /*
320 * Common SH-3 SCIF definitions.
321 */
322 [SCIx_SH3_SCIF_REGTYPE] = {
323 .regs = {
324 [SCSMR] = { 0x00, 8 },
325 [SCBRR] = { 0x02, 8 },
326 [SCSCR] = { 0x04, 8 },
327 [SCxTDR] = { 0x06, 8 },
328 [SCxSR] = { 0x08, 16 },
329 [SCxRDR] = { 0x0a, 8 },
330 [SCFCR] = { 0x0c, 8 },
331 [SCFDR] = { 0x0e, 16 },
332 },
333 .fifosize = 16,
334 .overrun_reg = SCLSR,
335 .overrun_mask = SCLSR_ORER,
336 .sampling_rate_mask = SCI_SR(32),
337 .error_mask = SCIF_DEFAULT_ERROR_MASK,
338 .error_clear = SCIF_ERROR_CLEAR,
339 },
340
341 /*
342 * Common SH-4(A) SCIF(B) definitions.
343 */
344 [SCIx_SH4_SCIF_REGTYPE] = {
345 .regs = {
346 [SCSMR] = { 0x00, 16 },
347 [SCBRR] = { 0x04, 8 },
348 [SCSCR] = { 0x08, 16 },
349 [SCxTDR] = { 0x0c, 8 },
350 [SCxSR] = { 0x10, 16 },
351 [SCxRDR] = { 0x14, 8 },
352 [SCFCR] = { 0x18, 16 },
353 [SCFDR] = { 0x1c, 16 },
354 [SCSPTR] = { 0x20, 16 },
355 [SCLSR] = { 0x24, 16 },
356 },
357 .fifosize = 16,
358 .overrun_reg = SCLSR,
359 .overrun_mask = SCLSR_ORER,
360 .sampling_rate_mask = SCI_SR(32),
361 .error_mask = SCIF_DEFAULT_ERROR_MASK,
362 .error_clear = SCIF_ERROR_CLEAR,
363 },
364
365 /*
366 * Common SCIF definitions for ports with a Baud Rate Generator for
367 * External Clock (BRG).
368 */
369 [SCIx_SH4_SCIF_BRG_REGTYPE] = {
370 .regs = {
371 [SCSMR] = { 0x00, 16 },
372 [SCBRR] = { 0x04, 8 },
373 [SCSCR] = { 0x08, 16 },
374 [SCxTDR] = { 0x0c, 8 },
375 [SCxSR] = { 0x10, 16 },
376 [SCxRDR] = { 0x14, 8 },
377 [SCFCR] = { 0x18, 16 },
378 [SCFDR] = { 0x1c, 16 },
379 [SCSPTR] = { 0x20, 16 },
380 [SCLSR] = { 0x24, 16 },
381 [SCDL] = { 0x30, 16 },
382 [SCCKS] = { 0x34, 16 },
383 },
384 .fifosize = 16,
385 .overrun_reg = SCLSR,
386 .overrun_mask = SCLSR_ORER,
387 .sampling_rate_mask = SCI_SR(32),
388 .error_mask = SCIF_DEFAULT_ERROR_MASK,
389 .error_clear = SCIF_ERROR_CLEAR,
390 },
391
392 /*
393 * Common HSCIF definitions.
394 */
395 [SCIx_HSCIF_REGTYPE] = {
396 .regs = {
397 [SCSMR] = { 0x00, 16 },
398 [SCBRR] = { 0x04, 8 },
399 [SCSCR] = { 0x08, 16 },
400 [SCxTDR] = { 0x0c, 8 },
401 [SCxSR] = { 0x10, 16 },
402 [SCxRDR] = { 0x14, 8 },
403 [SCFCR] = { 0x18, 16 },
404 [SCFDR] = { 0x1c, 16 },
405 [SCSPTR] = { 0x20, 16 },
406 [SCLSR] = { 0x24, 16 },
407 [HSSRR] = { 0x40, 16 },
408 [SCDL] = { 0x30, 16 },
409 [SCCKS] = { 0x34, 16 },
410 [HSRTRGR] = { 0x54, 16 },
411 [HSTTRGR] = { 0x58, 16 },
412 },
413 .fifosize = 128,
414 .overrun_reg = SCLSR,
415 .overrun_mask = SCLSR_ORER,
416 .sampling_rate_mask = SCI_SR_RANGE(8, 32),
417 .error_mask = SCIF_DEFAULT_ERROR_MASK,
418 .error_clear = SCIF_ERROR_CLEAR,
419 },
420
421 /*
422 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
423 * register.
424 */
425 [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
426 .regs = {
427 [SCSMR] = { 0x00, 16 },
428 [SCBRR] = { 0x04, 8 },
429 [SCSCR] = { 0x08, 16 },
430 [SCxTDR] = { 0x0c, 8 },
431 [SCxSR] = { 0x10, 16 },
432 [SCxRDR] = { 0x14, 8 },
433 [SCFCR] = { 0x18, 16 },
434 [SCFDR] = { 0x1c, 16 },
435 [SCLSR] = { 0x24, 16 },
436 },
437 .fifosize = 16,
438 .overrun_reg = SCLSR,
439 .overrun_mask = SCLSR_ORER,
440 .sampling_rate_mask = SCI_SR(32),
441 .error_mask = SCIF_DEFAULT_ERROR_MASK,
442 .error_clear = SCIF_ERROR_CLEAR,
443 },
444
445 /*
446 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
447 * count registers.
448 */
449 [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
450 .regs = {
451 [SCSMR] = { 0x00, 16 },
452 [SCBRR] = { 0x04, 8 },
453 [SCSCR] = { 0x08, 16 },
454 [SCxTDR] = { 0x0c, 8 },
455 [SCxSR] = { 0x10, 16 },
456 [SCxRDR] = { 0x14, 8 },
457 [SCFCR] = { 0x18, 16 },
458 [SCFDR] = { 0x1c, 16 },
459 [SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */
460 [SCRFDR] = { 0x20, 16 },
461 [SCSPTR] = { 0x24, 16 },
462 [SCLSR] = { 0x28, 16 },
463 },
464 .fifosize = 16,
465 .overrun_reg = SCLSR,
466 .overrun_mask = SCLSR_ORER,
467 .sampling_rate_mask = SCI_SR(32),
468 .error_mask = SCIF_DEFAULT_ERROR_MASK,
469 .error_clear = SCIF_ERROR_CLEAR,
470 },
471
472 /*
473 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
474 * registers.
475 */
476 [SCIx_SH7705_SCIF_REGTYPE] = {
477 .regs = {
478 [SCSMR] = { 0x00, 16 },
479 [SCBRR] = { 0x04, 8 },
480 [SCSCR] = { 0x08, 16 },
481 [SCxTDR] = { 0x20, 8 },
482 [SCxSR] = { 0x14, 16 },
483 [SCxRDR] = { 0x24, 8 },
484 [SCFCR] = { 0x18, 16 },
485 [SCFDR] = { 0x1c, 16 },
486 },
487 .fifosize = 64,
488 .overrun_reg = SCxSR,
489 .overrun_mask = SCIFA_ORER,
490 .sampling_rate_mask = SCI_SR(16),
491 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
492 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
493 },
494 };
495
496 #define sci_getreg(up, offset) (&to_sci_port(up)->params->regs[offset])
497
498 /*
499 * The "offset" here is rather misleading, in that it refers to an enum
500 * value relative to the port mapping rather than the fixed offset
501 * itself, which needs to be manually retrieved from the platform's
502 * register map for the given port.
503 */
sci_serial_in(struct uart_port * p,int offset)504 static unsigned int sci_serial_in(struct uart_port *p, int offset)
505 {
506 const struct plat_sci_reg *reg = sci_getreg(p, offset);
507
508 if (reg->size == 8)
509 return ioread8(p->membase + (reg->offset << p->regshift));
510 else if (reg->size == 16)
511 return ioread16(p->membase + (reg->offset << p->regshift));
512 else
513 WARN(1, "Invalid register access\n");
514
515 return 0;
516 }
517
sci_serial_out(struct uart_port * p,int offset,int value)518 static void sci_serial_out(struct uart_port *p, int offset, int value)
519 {
520 const struct plat_sci_reg *reg = sci_getreg(p, offset);
521
522 if (reg->size == 8)
523 iowrite8(value, p->membase + (reg->offset << p->regshift));
524 else if (reg->size == 16)
525 iowrite16(value, p->membase + (reg->offset << p->regshift));
526 else
527 WARN(1, "Invalid register access\n");
528 }
529
sci_port_enable(struct sci_port * sci_port)530 static void sci_port_enable(struct sci_port *sci_port)
531 {
532 unsigned int i;
533
534 if (!sci_port->port.dev)
535 return;
536
537 pm_runtime_get_sync(sci_port->port.dev);
538
539 for (i = 0; i < SCI_NUM_CLKS; i++) {
540 clk_prepare_enable(sci_port->clks[i]);
541 sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
542 }
543 sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
544 }
545
sci_port_disable(struct sci_port * sci_port)546 static void sci_port_disable(struct sci_port *sci_port)
547 {
548 unsigned int i;
549
550 if (!sci_port->port.dev)
551 return;
552
553 for (i = SCI_NUM_CLKS; i-- > 0; )
554 clk_disable_unprepare(sci_port->clks[i]);
555
556 pm_runtime_put_sync(sci_port->port.dev);
557 }
558
port_rx_irq_mask(struct uart_port * port)559 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
560 {
561 /*
562 * Not all ports (such as SCIFA) will support REIE. Rather than
563 * special-casing the port type, we check the port initialization
564 * IRQ enable mask to see whether the IRQ is desired at all. If
565 * it's unset, it's logically inferred that there's no point in
566 * testing for it.
567 */
568 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
569 }
570
sci_start_tx(struct uart_port * port)571 static void sci_start_tx(struct uart_port *port)
572 {
573 struct sci_port *s = to_sci_port(port);
574 unsigned short ctrl;
575
576 #ifdef CONFIG_SERIAL_SH_SCI_DMA
577 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
578 u16 new, scr = serial_port_in(port, SCSCR);
579 if (s->chan_tx)
580 new = scr | SCSCR_TDRQE;
581 else
582 new = scr & ~SCSCR_TDRQE;
583 if (new != scr)
584 serial_port_out(port, SCSCR, new);
585 }
586
587 if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
588 dma_submit_error(s->cookie_tx)) {
589 s->cookie_tx = 0;
590 schedule_work(&s->work_tx);
591 }
592 #endif
593
594 if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
595 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
596 ctrl = serial_port_in(port, SCSCR);
597 serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
598 }
599 }
600
sci_stop_tx(struct uart_port * port)601 static void sci_stop_tx(struct uart_port *port)
602 {
603 unsigned short ctrl;
604
605 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
606 ctrl = serial_port_in(port, SCSCR);
607
608 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
609 ctrl &= ~SCSCR_TDRQE;
610
611 ctrl &= ~SCSCR_TIE;
612
613 serial_port_out(port, SCSCR, ctrl);
614
615 #ifdef CONFIG_SERIAL_SH_SCI_DMA
616 if (to_sci_port(port)->chan_tx &&
617 !dma_submit_error(to_sci_port(port)->cookie_tx)) {
618 dmaengine_terminate_async(to_sci_port(port)->chan_tx);
619 to_sci_port(port)->cookie_tx = -EINVAL;
620 }
621 #endif
622 }
623
sci_start_rx(struct uart_port * port)624 static void sci_start_rx(struct uart_port *port)
625 {
626 unsigned short ctrl;
627
628 ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
629
630 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
631 ctrl &= ~SCSCR_RDRQE;
632
633 serial_port_out(port, SCSCR, ctrl);
634 }
635
sci_stop_rx(struct uart_port * port)636 static void sci_stop_rx(struct uart_port *port)
637 {
638 unsigned short ctrl;
639
640 ctrl = serial_port_in(port, SCSCR);
641
642 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
643 ctrl &= ~SCSCR_RDRQE;
644
645 ctrl &= ~port_rx_irq_mask(port);
646
647 serial_port_out(port, SCSCR, ctrl);
648 }
649
sci_clear_SCxSR(struct uart_port * port,unsigned int mask)650 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
651 {
652 if (port->type == PORT_SCI) {
653 /* Just store the mask */
654 serial_port_out(port, SCxSR, mask);
655 } else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
656 /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
657 /* Only clear the status bits we want to clear */
658 serial_port_out(port, SCxSR,
659 serial_port_in(port, SCxSR) & mask);
660 } else {
661 /* Store the mask, clear parity/framing errors */
662 serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
663 }
664 }
665
666 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
667 defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
668
669 #ifdef CONFIG_CONSOLE_POLL
sci_poll_get_char(struct uart_port * port)670 static int sci_poll_get_char(struct uart_port *port)
671 {
672 unsigned short status;
673 int c;
674
675 do {
676 status = serial_port_in(port, SCxSR);
677 if (status & SCxSR_ERRORS(port)) {
678 sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
679 continue;
680 }
681 break;
682 } while (1);
683
684 if (!(status & SCxSR_RDxF(port)))
685 return NO_POLL_CHAR;
686
687 c = serial_port_in(port, SCxRDR);
688
689 /* Dummy read */
690 serial_port_in(port, SCxSR);
691 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
692
693 return c;
694 }
695 #endif
696
sci_poll_put_char(struct uart_port * port,unsigned char c)697 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
698 {
699 unsigned short status;
700
701 do {
702 status = serial_port_in(port, SCxSR);
703 } while (!(status & SCxSR_TDxE(port)));
704
705 serial_port_out(port, SCxTDR, c);
706 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
707 }
708 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
709 CONFIG_SERIAL_SH_SCI_EARLYCON */
710
sci_init_pins(struct uart_port * port,unsigned int cflag)711 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
712 {
713 struct sci_port *s = to_sci_port(port);
714
715 /*
716 * Use port-specific handler if provided.
717 */
718 if (s->cfg->ops && s->cfg->ops->init_pins) {
719 s->cfg->ops->init_pins(port, cflag);
720 return;
721 }
722
723 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
724 u16 data = serial_port_in(port, SCPDR);
725 u16 ctrl = serial_port_in(port, SCPCR);
726
727 /* Enable RXD and TXD pin functions */
728 ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
729 if (to_sci_port(port)->has_rtscts) {
730 /* RTS# is output, active low, unless autorts */
731 if (!(port->mctrl & TIOCM_RTS)) {
732 ctrl |= SCPCR_RTSC;
733 data |= SCPDR_RTSD;
734 } else if (!s->autorts) {
735 ctrl |= SCPCR_RTSC;
736 data &= ~SCPDR_RTSD;
737 } else {
738 /* Enable RTS# pin function */
739 ctrl &= ~SCPCR_RTSC;
740 }
741 /* Enable CTS# pin function */
742 ctrl &= ~SCPCR_CTSC;
743 }
744 serial_port_out(port, SCPDR, data);
745 serial_port_out(port, SCPCR, ctrl);
746 } else if (sci_getreg(port, SCSPTR)->size) {
747 u16 status = serial_port_in(port, SCSPTR);
748
749 /* RTS# is always output; and active low, unless autorts */
750 status |= SCSPTR_RTSIO;
751 if (!(port->mctrl & TIOCM_RTS))
752 status |= SCSPTR_RTSDT;
753 else if (!s->autorts)
754 status &= ~SCSPTR_RTSDT;
755 /* CTS# and SCK are inputs */
756 status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
757 serial_port_out(port, SCSPTR, status);
758 }
759 }
760
sci_txfill(struct uart_port * port)761 static int sci_txfill(struct uart_port *port)
762 {
763 struct sci_port *s = to_sci_port(port);
764 unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
765 const struct plat_sci_reg *reg;
766
767 reg = sci_getreg(port, SCTFDR);
768 if (reg->size)
769 return serial_port_in(port, SCTFDR) & fifo_mask;
770
771 reg = sci_getreg(port, SCFDR);
772 if (reg->size)
773 return serial_port_in(port, SCFDR) >> 8;
774
775 return !(serial_port_in(port, SCxSR) & SCI_TDRE);
776 }
777
sci_txroom(struct uart_port * port)778 static int sci_txroom(struct uart_port *port)
779 {
780 return port->fifosize - sci_txfill(port);
781 }
782
sci_rxfill(struct uart_port * port)783 static int sci_rxfill(struct uart_port *port)
784 {
785 struct sci_port *s = to_sci_port(port);
786 unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
787 const struct plat_sci_reg *reg;
788
789 reg = sci_getreg(port, SCRFDR);
790 if (reg->size)
791 return serial_port_in(port, SCRFDR) & fifo_mask;
792
793 reg = sci_getreg(port, SCFDR);
794 if (reg->size)
795 return serial_port_in(port, SCFDR) & fifo_mask;
796
797 return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
798 }
799
800 /* ********************************************************************** *
801 * the interrupt related routines *
802 * ********************************************************************** */
803
sci_transmit_chars(struct uart_port * port)804 static void sci_transmit_chars(struct uart_port *port)
805 {
806 struct circ_buf *xmit = &port->state->xmit;
807 unsigned int stopped = uart_tx_stopped(port);
808 unsigned short status;
809 unsigned short ctrl;
810 int count;
811
812 status = serial_port_in(port, SCxSR);
813 if (!(status & SCxSR_TDxE(port))) {
814 ctrl = serial_port_in(port, SCSCR);
815 if (uart_circ_empty(xmit))
816 ctrl &= ~SCSCR_TIE;
817 else
818 ctrl |= SCSCR_TIE;
819 serial_port_out(port, SCSCR, ctrl);
820 return;
821 }
822
823 count = sci_txroom(port);
824
825 do {
826 unsigned char c;
827
828 if (port->x_char) {
829 c = port->x_char;
830 port->x_char = 0;
831 } else if (!uart_circ_empty(xmit) && !stopped) {
832 c = xmit->buf[xmit->tail];
833 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
834 } else {
835 break;
836 }
837
838 serial_port_out(port, SCxTDR, c);
839
840 port->icount.tx++;
841 } while (--count > 0);
842
843 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
844
845 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
846 uart_write_wakeup(port);
847 if (uart_circ_empty(xmit))
848 sci_stop_tx(port);
849
850 }
851
sci_receive_chars(struct uart_port * port)852 static void sci_receive_chars(struct uart_port *port)
853 {
854 struct tty_port *tport = &port->state->port;
855 int i, count, copied = 0;
856 unsigned short status;
857 unsigned char flag;
858
859 status = serial_port_in(port, SCxSR);
860 if (!(status & SCxSR_RDxF(port)))
861 return;
862
863 while (1) {
864 /* Don't copy more bytes than there is room for in the buffer */
865 count = tty_buffer_request_room(tport, sci_rxfill(port));
866
867 /* If for any reason we can't copy more data, we're done! */
868 if (count == 0)
869 break;
870
871 if (port->type == PORT_SCI) {
872 char c = serial_port_in(port, SCxRDR);
873 if (uart_handle_sysrq_char(port, c))
874 count = 0;
875 else
876 tty_insert_flip_char(tport, c, TTY_NORMAL);
877 } else {
878 for (i = 0; i < count; i++) {
879 char c;
880
881 if (port->type == PORT_SCIF ||
882 port->type == PORT_HSCIF) {
883 status = serial_port_in(port, SCxSR);
884 c = serial_port_in(port, SCxRDR);
885 } else {
886 c = serial_port_in(port, SCxRDR);
887 status = serial_port_in(port, SCxSR);
888 }
889 if (uart_handle_sysrq_char(port, c)) {
890 count--; i--;
891 continue;
892 }
893
894 /* Store data and status */
895 if (status & SCxSR_FER(port)) {
896 flag = TTY_FRAME;
897 port->icount.frame++;
898 dev_notice(port->dev, "frame error\n");
899 } else if (status & SCxSR_PER(port)) {
900 flag = TTY_PARITY;
901 port->icount.parity++;
902 dev_notice(port->dev, "parity error\n");
903 } else
904 flag = TTY_NORMAL;
905
906 tty_insert_flip_char(tport, c, flag);
907 }
908 }
909
910 serial_port_in(port, SCxSR); /* dummy read */
911 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
912
913 copied += count;
914 port->icount.rx += count;
915 }
916
917 if (copied) {
918 /* Tell the rest of the system the news. New characters! */
919 tty_flip_buffer_push(tport);
920 } else {
921 /* TTY buffers full; read from RX reg to prevent lockup */
922 serial_port_in(port, SCxRDR);
923 serial_port_in(port, SCxSR); /* dummy read */
924 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
925 }
926 }
927
sci_handle_errors(struct uart_port * port)928 static int sci_handle_errors(struct uart_port *port)
929 {
930 int copied = 0;
931 unsigned short status = serial_port_in(port, SCxSR);
932 struct tty_port *tport = &port->state->port;
933 struct sci_port *s = to_sci_port(port);
934
935 /* Handle overruns */
936 if (status & s->params->overrun_mask) {
937 port->icount.overrun++;
938
939 /* overrun error */
940 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
941 copied++;
942
943 dev_notice(port->dev, "overrun error\n");
944 }
945
946 if (status & SCxSR_FER(port)) {
947 /* frame error */
948 port->icount.frame++;
949
950 if (tty_insert_flip_char(tport, 0, TTY_FRAME))
951 copied++;
952
953 dev_notice(port->dev, "frame error\n");
954 }
955
956 if (status & SCxSR_PER(port)) {
957 /* parity error */
958 port->icount.parity++;
959
960 if (tty_insert_flip_char(tport, 0, TTY_PARITY))
961 copied++;
962
963 dev_notice(port->dev, "parity error\n");
964 }
965
966 if (copied)
967 tty_flip_buffer_push(tport);
968
969 return copied;
970 }
971
sci_handle_fifo_overrun(struct uart_port * port)972 static int sci_handle_fifo_overrun(struct uart_port *port)
973 {
974 struct tty_port *tport = &port->state->port;
975 struct sci_port *s = to_sci_port(port);
976 const struct plat_sci_reg *reg;
977 int copied = 0;
978 u16 status;
979
980 reg = sci_getreg(port, s->params->overrun_reg);
981 if (!reg->size)
982 return 0;
983
984 status = serial_port_in(port, s->params->overrun_reg);
985 if (status & s->params->overrun_mask) {
986 status &= ~s->params->overrun_mask;
987 serial_port_out(port, s->params->overrun_reg, status);
988
989 port->icount.overrun++;
990
991 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
992 tty_flip_buffer_push(tport);
993
994 dev_dbg(port->dev, "overrun error\n");
995 copied++;
996 }
997
998 return copied;
999 }
1000
sci_handle_breaks(struct uart_port * port)1001 static int sci_handle_breaks(struct uart_port *port)
1002 {
1003 int copied = 0;
1004 unsigned short status = serial_port_in(port, SCxSR);
1005 struct tty_port *tport = &port->state->port;
1006
1007 if (uart_handle_break(port))
1008 return 0;
1009
1010 if (status & SCxSR_BRK(port)) {
1011 port->icount.brk++;
1012
1013 /* Notify of BREAK */
1014 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1015 copied++;
1016
1017 dev_dbg(port->dev, "BREAK detected\n");
1018 }
1019
1020 if (copied)
1021 tty_flip_buffer_push(tport);
1022
1023 copied += sci_handle_fifo_overrun(port);
1024
1025 return copied;
1026 }
1027
scif_set_rtrg(struct uart_port * port,int rx_trig)1028 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1029 {
1030 unsigned int bits;
1031
1032 if (rx_trig >= port->fifosize)
1033 rx_trig = port->fifosize - 1;
1034 if (rx_trig < 1)
1035 rx_trig = 1;
1036
1037 /* HSCIF can be set to an arbitrary level. */
1038 if (sci_getreg(port, HSRTRGR)->size) {
1039 serial_port_out(port, HSRTRGR, rx_trig);
1040 return rx_trig;
1041 }
1042
1043 switch (port->type) {
1044 case PORT_SCIF:
1045 if (rx_trig < 4) {
1046 bits = 0;
1047 rx_trig = 1;
1048 } else if (rx_trig < 8) {
1049 bits = SCFCR_RTRG0;
1050 rx_trig = 4;
1051 } else if (rx_trig < 14) {
1052 bits = SCFCR_RTRG1;
1053 rx_trig = 8;
1054 } else {
1055 bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1056 rx_trig = 14;
1057 }
1058 break;
1059 case PORT_SCIFA:
1060 case PORT_SCIFB:
1061 if (rx_trig < 16) {
1062 bits = 0;
1063 rx_trig = 1;
1064 } else if (rx_trig < 32) {
1065 bits = SCFCR_RTRG0;
1066 rx_trig = 16;
1067 } else if (rx_trig < 48) {
1068 bits = SCFCR_RTRG1;
1069 rx_trig = 32;
1070 } else {
1071 bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1072 rx_trig = 48;
1073 }
1074 break;
1075 default:
1076 WARN(1, "unknown FIFO configuration");
1077 return 1;
1078 }
1079
1080 serial_port_out(port, SCFCR,
1081 (serial_port_in(port, SCFCR) &
1082 ~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1083
1084 return rx_trig;
1085 }
1086
scif_rtrg_enabled(struct uart_port * port)1087 static int scif_rtrg_enabled(struct uart_port *port)
1088 {
1089 if (sci_getreg(port, HSRTRGR)->size)
1090 return serial_port_in(port, HSRTRGR) != 0;
1091 else
1092 return (serial_port_in(port, SCFCR) &
1093 (SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1094 }
1095
rx_fifo_timer_fn(struct timer_list * t)1096 static void rx_fifo_timer_fn(struct timer_list *t)
1097 {
1098 struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1099 struct uart_port *port = &s->port;
1100
1101 dev_dbg(port->dev, "Rx timed out\n");
1102 scif_set_rtrg(port, 1);
1103 }
1104
rx_fifo_trigger_show(struct device * dev,struct device_attribute * attr,char * buf)1105 static ssize_t rx_fifo_trigger_show(struct device *dev,
1106 struct device_attribute *attr, char *buf)
1107 {
1108 struct uart_port *port = dev_get_drvdata(dev);
1109 struct sci_port *sci = to_sci_port(port);
1110
1111 return sprintf(buf, "%d\n", sci->rx_trigger);
1112 }
1113
rx_fifo_trigger_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1114 static ssize_t rx_fifo_trigger_store(struct device *dev,
1115 struct device_attribute *attr,
1116 const char *buf, size_t count)
1117 {
1118 struct uart_port *port = dev_get_drvdata(dev);
1119 struct sci_port *sci = to_sci_port(port);
1120 int ret;
1121 long r;
1122
1123 ret = kstrtol(buf, 0, &r);
1124 if (ret)
1125 return ret;
1126
1127 sci->rx_trigger = scif_set_rtrg(port, r);
1128 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1129 scif_set_rtrg(port, 1);
1130
1131 return count;
1132 }
1133
1134 static DEVICE_ATTR_RW(rx_fifo_trigger);
1135
rx_fifo_timeout_show(struct device * dev,struct device_attribute * attr,char * buf)1136 static ssize_t rx_fifo_timeout_show(struct device *dev,
1137 struct device_attribute *attr,
1138 char *buf)
1139 {
1140 struct uart_port *port = dev_get_drvdata(dev);
1141 struct sci_port *sci = to_sci_port(port);
1142 int v;
1143
1144 if (port->type == PORT_HSCIF)
1145 v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1146 else
1147 v = sci->rx_fifo_timeout;
1148
1149 return sprintf(buf, "%d\n", v);
1150 }
1151
rx_fifo_timeout_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1152 static ssize_t rx_fifo_timeout_store(struct device *dev,
1153 struct device_attribute *attr,
1154 const char *buf,
1155 size_t count)
1156 {
1157 struct uart_port *port = dev_get_drvdata(dev);
1158 struct sci_port *sci = to_sci_port(port);
1159 int ret;
1160 long r;
1161
1162 ret = kstrtol(buf, 0, &r);
1163 if (ret)
1164 return ret;
1165
1166 if (port->type == PORT_HSCIF) {
1167 if (r < 0 || r > 3)
1168 return -EINVAL;
1169 sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1170 } else {
1171 sci->rx_fifo_timeout = r;
1172 scif_set_rtrg(port, 1);
1173 if (r > 0)
1174 timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1175 }
1176
1177 return count;
1178 }
1179
1180 static DEVICE_ATTR_RW(rx_fifo_timeout);
1181
1182
1183 #ifdef CONFIG_SERIAL_SH_SCI_DMA
sci_dma_tx_complete(void * arg)1184 static void sci_dma_tx_complete(void *arg)
1185 {
1186 struct sci_port *s = arg;
1187 struct uart_port *port = &s->port;
1188 struct circ_buf *xmit = &port->state->xmit;
1189 unsigned long flags;
1190
1191 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1192
1193 spin_lock_irqsave(&port->lock, flags);
1194
1195 xmit->tail += s->tx_dma_len;
1196 xmit->tail &= UART_XMIT_SIZE - 1;
1197
1198 port->icount.tx += s->tx_dma_len;
1199
1200 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1201 uart_write_wakeup(port);
1202
1203 if (!uart_circ_empty(xmit)) {
1204 s->cookie_tx = 0;
1205 schedule_work(&s->work_tx);
1206 } else {
1207 s->cookie_tx = -EINVAL;
1208 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1209 u16 ctrl = serial_port_in(port, SCSCR);
1210 serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1211 }
1212 }
1213
1214 spin_unlock_irqrestore(&port->lock, flags);
1215 }
1216
1217 /* Locking: called with port lock held */
sci_dma_rx_push(struct sci_port * s,void * buf,size_t count)1218 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1219 {
1220 struct uart_port *port = &s->port;
1221 struct tty_port *tport = &port->state->port;
1222 int copied;
1223
1224 copied = tty_insert_flip_string(tport, buf, count);
1225 if (copied < count)
1226 port->icount.buf_overrun++;
1227
1228 port->icount.rx += copied;
1229
1230 return copied;
1231 }
1232
sci_dma_rx_find_active(struct sci_port * s)1233 static int sci_dma_rx_find_active(struct sci_port *s)
1234 {
1235 unsigned int i;
1236
1237 for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1238 if (s->active_rx == s->cookie_rx[i])
1239 return i;
1240
1241 return -1;
1242 }
1243
sci_dma_rx_chan_invalidate(struct sci_port * s)1244 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1245 {
1246 unsigned int i;
1247
1248 s->chan_rx = NULL;
1249 for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1250 s->cookie_rx[i] = -EINVAL;
1251 s->active_rx = 0;
1252 }
1253
sci_dma_rx_release(struct sci_port * s)1254 static void sci_dma_rx_release(struct sci_port *s)
1255 {
1256 struct dma_chan *chan = s->chan_rx_saved;
1257
1258 s->chan_rx_saved = NULL;
1259 sci_dma_rx_chan_invalidate(s);
1260 dmaengine_terminate_sync(chan);
1261 dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1262 sg_dma_address(&s->sg_rx[0]));
1263 dma_release_channel(chan);
1264 }
1265
start_hrtimer_us(struct hrtimer * hrt,unsigned long usec)1266 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1267 {
1268 long sec = usec / 1000000;
1269 long nsec = (usec % 1000000) * 1000;
1270 ktime_t t = ktime_set(sec, nsec);
1271
1272 hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1273 }
1274
sci_dma_rx_reenable_irq(struct sci_port * s)1275 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1276 {
1277 struct uart_port *port = &s->port;
1278 u16 scr;
1279
1280 /* Direct new serial port interrupts back to CPU */
1281 scr = serial_port_in(port, SCSCR);
1282 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1283 scr &= ~SCSCR_RDRQE;
1284 enable_irq(s->irqs[SCIx_RXI_IRQ]);
1285 }
1286 serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1287 }
1288
sci_dma_rx_complete(void * arg)1289 static void sci_dma_rx_complete(void *arg)
1290 {
1291 struct sci_port *s = arg;
1292 struct dma_chan *chan = s->chan_rx;
1293 struct uart_port *port = &s->port;
1294 struct dma_async_tx_descriptor *desc;
1295 unsigned long flags;
1296 int active, count = 0;
1297
1298 dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1299 s->active_rx);
1300
1301 spin_lock_irqsave(&port->lock, flags);
1302
1303 active = sci_dma_rx_find_active(s);
1304 if (active >= 0)
1305 count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1306
1307 start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1308
1309 if (count)
1310 tty_flip_buffer_push(&port->state->port);
1311
1312 desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1313 DMA_DEV_TO_MEM,
1314 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1315 if (!desc)
1316 goto fail;
1317
1318 desc->callback = sci_dma_rx_complete;
1319 desc->callback_param = s;
1320 s->cookie_rx[active] = dmaengine_submit(desc);
1321 if (dma_submit_error(s->cookie_rx[active]))
1322 goto fail;
1323
1324 s->active_rx = s->cookie_rx[!active];
1325
1326 dma_async_issue_pending(chan);
1327
1328 spin_unlock_irqrestore(&port->lock, flags);
1329 dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1330 __func__, s->cookie_rx[active], active, s->active_rx);
1331 return;
1332
1333 fail:
1334 spin_unlock_irqrestore(&port->lock, flags);
1335 dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1336 /* Switch to PIO */
1337 spin_lock_irqsave(&port->lock, flags);
1338 dmaengine_terminate_async(chan);
1339 sci_dma_rx_chan_invalidate(s);
1340 sci_dma_rx_reenable_irq(s);
1341 spin_unlock_irqrestore(&port->lock, flags);
1342 }
1343
sci_dma_tx_release(struct sci_port * s)1344 static void sci_dma_tx_release(struct sci_port *s)
1345 {
1346 struct dma_chan *chan = s->chan_tx_saved;
1347
1348 cancel_work_sync(&s->work_tx);
1349 s->chan_tx_saved = s->chan_tx = NULL;
1350 s->cookie_tx = -EINVAL;
1351 dmaengine_terminate_sync(chan);
1352 dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1353 DMA_TO_DEVICE);
1354 dma_release_channel(chan);
1355 }
1356
sci_dma_rx_submit(struct sci_port * s,bool port_lock_held)1357 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1358 {
1359 struct dma_chan *chan = s->chan_rx;
1360 struct uart_port *port = &s->port;
1361 unsigned long flags;
1362 int i;
1363
1364 for (i = 0; i < 2; i++) {
1365 struct scatterlist *sg = &s->sg_rx[i];
1366 struct dma_async_tx_descriptor *desc;
1367
1368 desc = dmaengine_prep_slave_sg(chan,
1369 sg, 1, DMA_DEV_TO_MEM,
1370 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1371 if (!desc)
1372 goto fail;
1373
1374 desc->callback = sci_dma_rx_complete;
1375 desc->callback_param = s;
1376 s->cookie_rx[i] = dmaengine_submit(desc);
1377 if (dma_submit_error(s->cookie_rx[i]))
1378 goto fail;
1379
1380 }
1381
1382 s->active_rx = s->cookie_rx[0];
1383
1384 dma_async_issue_pending(chan);
1385 return 0;
1386
1387 fail:
1388 /* Switch to PIO */
1389 if (!port_lock_held)
1390 spin_lock_irqsave(&port->lock, flags);
1391 if (i)
1392 dmaengine_terminate_async(chan);
1393 sci_dma_rx_chan_invalidate(s);
1394 sci_start_rx(port);
1395 if (!port_lock_held)
1396 spin_unlock_irqrestore(&port->lock, flags);
1397 return -EAGAIN;
1398 }
1399
sci_dma_tx_work_fn(struct work_struct * work)1400 static void sci_dma_tx_work_fn(struct work_struct *work)
1401 {
1402 struct sci_port *s = container_of(work, struct sci_port, work_tx);
1403 struct dma_async_tx_descriptor *desc;
1404 struct dma_chan *chan = s->chan_tx;
1405 struct uart_port *port = &s->port;
1406 struct circ_buf *xmit = &port->state->xmit;
1407 unsigned long flags;
1408 dma_addr_t buf;
1409 int head, tail;
1410
1411 /*
1412 * DMA is idle now.
1413 * Port xmit buffer is already mapped, and it is one page... Just adjust
1414 * offsets and lengths. Since it is a circular buffer, we have to
1415 * transmit till the end, and then the rest. Take the port lock to get a
1416 * consistent xmit buffer state.
1417 */
1418 spin_lock_irq(&port->lock);
1419 head = xmit->head;
1420 tail = xmit->tail;
1421 buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1422 s->tx_dma_len = min_t(unsigned int,
1423 CIRC_CNT(head, tail, UART_XMIT_SIZE),
1424 CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1425 if (!s->tx_dma_len) {
1426 /* Transmit buffer has been flushed */
1427 spin_unlock_irq(&port->lock);
1428 return;
1429 }
1430
1431 desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1432 DMA_MEM_TO_DEV,
1433 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1434 if (!desc) {
1435 spin_unlock_irq(&port->lock);
1436 dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1437 goto switch_to_pio;
1438 }
1439
1440 dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1441 DMA_TO_DEVICE);
1442
1443 desc->callback = sci_dma_tx_complete;
1444 desc->callback_param = s;
1445 s->cookie_tx = dmaengine_submit(desc);
1446 if (dma_submit_error(s->cookie_tx)) {
1447 spin_unlock_irq(&port->lock);
1448 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1449 goto switch_to_pio;
1450 }
1451
1452 spin_unlock_irq(&port->lock);
1453 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1454 __func__, xmit->buf, tail, head, s->cookie_tx);
1455
1456 dma_async_issue_pending(chan);
1457 return;
1458
1459 switch_to_pio:
1460 spin_lock_irqsave(&port->lock, flags);
1461 s->chan_tx = NULL;
1462 sci_start_tx(port);
1463 spin_unlock_irqrestore(&port->lock, flags);
1464 return;
1465 }
1466
sci_dma_rx_timer_fn(struct hrtimer * t)1467 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1468 {
1469 struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1470 struct dma_chan *chan = s->chan_rx;
1471 struct uart_port *port = &s->port;
1472 struct dma_tx_state state;
1473 enum dma_status status;
1474 unsigned long flags;
1475 unsigned int read;
1476 int active, count;
1477
1478 dev_dbg(port->dev, "DMA Rx timed out\n");
1479
1480 spin_lock_irqsave(&port->lock, flags);
1481
1482 active = sci_dma_rx_find_active(s);
1483 if (active < 0) {
1484 spin_unlock_irqrestore(&port->lock, flags);
1485 return HRTIMER_NORESTART;
1486 }
1487
1488 status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1489 if (status == DMA_COMPLETE) {
1490 spin_unlock_irqrestore(&port->lock, flags);
1491 dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1492 s->active_rx, active);
1493
1494 /* Let packet complete handler take care of the packet */
1495 return HRTIMER_NORESTART;
1496 }
1497
1498 dmaengine_pause(chan);
1499
1500 /*
1501 * sometimes DMA transfer doesn't stop even if it is stopped and
1502 * data keeps on coming until transaction is complete so check
1503 * for DMA_COMPLETE again
1504 * Let packet complete handler take care of the packet
1505 */
1506 status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1507 if (status == DMA_COMPLETE) {
1508 spin_unlock_irqrestore(&port->lock, flags);
1509 dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1510 return HRTIMER_NORESTART;
1511 }
1512
1513 /* Handle incomplete DMA receive */
1514 dmaengine_terminate_async(s->chan_rx);
1515 read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1516
1517 if (read) {
1518 count = sci_dma_rx_push(s, s->rx_buf[active], read);
1519 if (count)
1520 tty_flip_buffer_push(&port->state->port);
1521 }
1522
1523 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1524 sci_dma_rx_submit(s, true);
1525
1526 sci_dma_rx_reenable_irq(s);
1527
1528 spin_unlock_irqrestore(&port->lock, flags);
1529
1530 return HRTIMER_NORESTART;
1531 }
1532
sci_request_dma_chan(struct uart_port * port,enum dma_transfer_direction dir)1533 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1534 enum dma_transfer_direction dir)
1535 {
1536 struct dma_chan *chan;
1537 struct dma_slave_config cfg;
1538 int ret;
1539
1540 chan = dma_request_slave_channel(port->dev,
1541 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1542 if (!chan) {
1543 dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1544 return NULL;
1545 }
1546
1547 memset(&cfg, 0, sizeof(cfg));
1548 cfg.direction = dir;
1549 if (dir == DMA_MEM_TO_DEV) {
1550 cfg.dst_addr = port->mapbase +
1551 (sci_getreg(port, SCxTDR)->offset << port->regshift);
1552 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1553 } else {
1554 cfg.src_addr = port->mapbase +
1555 (sci_getreg(port, SCxRDR)->offset << port->regshift);
1556 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1557 }
1558
1559 ret = dmaengine_slave_config(chan, &cfg);
1560 if (ret) {
1561 dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1562 dma_release_channel(chan);
1563 return NULL;
1564 }
1565
1566 return chan;
1567 }
1568
sci_request_dma(struct uart_port * port)1569 static void sci_request_dma(struct uart_port *port)
1570 {
1571 struct sci_port *s = to_sci_port(port);
1572 struct dma_chan *chan;
1573
1574 dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1575
1576 /*
1577 * DMA on console may interfere with Kernel log messages which use
1578 * plain putchar(). So, simply don't use it with a console.
1579 */
1580 if (uart_console(port))
1581 return;
1582
1583 if (!port->dev->of_node)
1584 return;
1585
1586 s->cookie_tx = -EINVAL;
1587
1588 /*
1589 * Don't request a dma channel if no channel was specified
1590 * in the device tree.
1591 */
1592 if (!of_find_property(port->dev->of_node, "dmas", NULL))
1593 return;
1594
1595 chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1596 dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1597 if (chan) {
1598 /* UART circular tx buffer is an aligned page. */
1599 s->tx_dma_addr = dma_map_single(chan->device->dev,
1600 port->state->xmit.buf,
1601 UART_XMIT_SIZE,
1602 DMA_TO_DEVICE);
1603 if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1604 dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1605 dma_release_channel(chan);
1606 } else {
1607 dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1608 __func__, UART_XMIT_SIZE,
1609 port->state->xmit.buf, &s->tx_dma_addr);
1610
1611 INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1612 s->chan_tx_saved = s->chan_tx = chan;
1613 }
1614 }
1615
1616 chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1617 dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1618 if (chan) {
1619 unsigned int i;
1620 dma_addr_t dma;
1621 void *buf;
1622
1623 s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1624 buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1625 &dma, GFP_KERNEL);
1626 if (!buf) {
1627 dev_warn(port->dev,
1628 "Failed to allocate Rx dma buffer, using PIO\n");
1629 dma_release_channel(chan);
1630 return;
1631 }
1632
1633 for (i = 0; i < 2; i++) {
1634 struct scatterlist *sg = &s->sg_rx[i];
1635
1636 sg_init_table(sg, 1);
1637 s->rx_buf[i] = buf;
1638 sg_dma_address(sg) = dma;
1639 sg_dma_len(sg) = s->buf_len_rx;
1640
1641 buf += s->buf_len_rx;
1642 dma += s->buf_len_rx;
1643 }
1644
1645 hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1646 s->rx_timer.function = sci_dma_rx_timer_fn;
1647
1648 s->chan_rx_saved = s->chan_rx = chan;
1649
1650 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1651 sci_dma_rx_submit(s, false);
1652 }
1653 }
1654
sci_free_dma(struct uart_port * port)1655 static void sci_free_dma(struct uart_port *port)
1656 {
1657 struct sci_port *s = to_sci_port(port);
1658
1659 if (s->chan_tx_saved)
1660 sci_dma_tx_release(s);
1661 if (s->chan_rx_saved)
1662 sci_dma_rx_release(s);
1663 }
1664
sci_flush_buffer(struct uart_port * port)1665 static void sci_flush_buffer(struct uart_port *port)
1666 {
1667 struct sci_port *s = to_sci_port(port);
1668
1669 /*
1670 * In uart_flush_buffer(), the xmit circular buffer has just been
1671 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1672 * pending transfers
1673 */
1674 s->tx_dma_len = 0;
1675 if (s->chan_tx) {
1676 dmaengine_terminate_async(s->chan_tx);
1677 s->cookie_tx = -EINVAL;
1678 }
1679 }
1680 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
sci_request_dma(struct uart_port * port)1681 static inline void sci_request_dma(struct uart_port *port)
1682 {
1683 }
1684
sci_free_dma(struct uart_port * port)1685 static inline void sci_free_dma(struct uart_port *port)
1686 {
1687 }
1688
1689 #define sci_flush_buffer NULL
1690 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1691
sci_rx_interrupt(int irq,void * ptr)1692 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1693 {
1694 struct uart_port *port = ptr;
1695 struct sci_port *s = to_sci_port(port);
1696
1697 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1698 if (s->chan_rx) {
1699 u16 scr = serial_port_in(port, SCSCR);
1700 u16 ssr = serial_port_in(port, SCxSR);
1701
1702 /* Disable future Rx interrupts */
1703 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1704 disable_irq_nosync(irq);
1705 scr |= SCSCR_RDRQE;
1706 } else {
1707 if (sci_dma_rx_submit(s, false) < 0)
1708 goto handle_pio;
1709
1710 scr &= ~SCSCR_RIE;
1711 }
1712 serial_port_out(port, SCSCR, scr);
1713 /* Clear current interrupt */
1714 serial_port_out(port, SCxSR,
1715 ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1716 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1717 jiffies, s->rx_timeout);
1718 start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1719
1720 return IRQ_HANDLED;
1721 }
1722
1723 handle_pio:
1724 #endif
1725
1726 if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1727 if (!scif_rtrg_enabled(port))
1728 scif_set_rtrg(port, s->rx_trigger);
1729
1730 mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1731 s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1732 }
1733
1734 /* I think sci_receive_chars has to be called irrespective
1735 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1736 * to be disabled?
1737 */
1738 sci_receive_chars(port);
1739
1740 return IRQ_HANDLED;
1741 }
1742
sci_tx_interrupt(int irq,void * ptr)1743 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1744 {
1745 struct uart_port *port = ptr;
1746 unsigned long flags;
1747
1748 spin_lock_irqsave(&port->lock, flags);
1749 sci_transmit_chars(port);
1750 spin_unlock_irqrestore(&port->lock, flags);
1751
1752 return IRQ_HANDLED;
1753 }
1754
sci_br_interrupt(int irq,void * ptr)1755 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1756 {
1757 struct uart_port *port = ptr;
1758
1759 /* Handle BREAKs */
1760 sci_handle_breaks(port);
1761
1762 /* drop invalid character received before break was detected */
1763 serial_port_in(port, SCxRDR);
1764
1765 sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1766
1767 return IRQ_HANDLED;
1768 }
1769
sci_er_interrupt(int irq,void * ptr)1770 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1771 {
1772 struct uart_port *port = ptr;
1773 struct sci_port *s = to_sci_port(port);
1774
1775 if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1776 /* Break and Error interrupts are muxed */
1777 unsigned short ssr_status = serial_port_in(port, SCxSR);
1778
1779 /* Break Interrupt */
1780 if (ssr_status & SCxSR_BRK(port))
1781 sci_br_interrupt(irq, ptr);
1782
1783 /* Break only? */
1784 if (!(ssr_status & SCxSR_ERRORS(port)))
1785 return IRQ_HANDLED;
1786 }
1787
1788 /* Handle errors */
1789 if (port->type == PORT_SCI) {
1790 if (sci_handle_errors(port)) {
1791 /* discard character in rx buffer */
1792 serial_port_in(port, SCxSR);
1793 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1794 }
1795 } else {
1796 sci_handle_fifo_overrun(port);
1797 if (!s->chan_rx)
1798 sci_receive_chars(port);
1799 }
1800
1801 sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1802
1803 /* Kick the transmission */
1804 if (!s->chan_tx)
1805 sci_tx_interrupt(irq, ptr);
1806
1807 return IRQ_HANDLED;
1808 }
1809
sci_mpxed_interrupt(int irq,void * ptr)1810 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1811 {
1812 unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1813 struct uart_port *port = ptr;
1814 struct sci_port *s = to_sci_port(port);
1815 irqreturn_t ret = IRQ_NONE;
1816
1817 ssr_status = serial_port_in(port, SCxSR);
1818 scr_status = serial_port_in(port, SCSCR);
1819 if (s->params->overrun_reg == SCxSR)
1820 orer_status = ssr_status;
1821 else if (sci_getreg(port, s->params->overrun_reg)->size)
1822 orer_status = serial_port_in(port, s->params->overrun_reg);
1823
1824 err_enabled = scr_status & port_rx_irq_mask(port);
1825
1826 /* Tx Interrupt */
1827 if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1828 !s->chan_tx)
1829 ret = sci_tx_interrupt(irq, ptr);
1830
1831 /*
1832 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1833 * DR flags
1834 */
1835 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1836 (scr_status & SCSCR_RIE))
1837 ret = sci_rx_interrupt(irq, ptr);
1838
1839 /* Error Interrupt */
1840 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1841 ret = sci_er_interrupt(irq, ptr);
1842
1843 /* Break Interrupt */
1844 if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1845 (ssr_status & SCxSR_BRK(port)) && err_enabled)
1846 ret = sci_br_interrupt(irq, ptr);
1847
1848 /* Overrun Interrupt */
1849 if (orer_status & s->params->overrun_mask) {
1850 sci_handle_fifo_overrun(port);
1851 ret = IRQ_HANDLED;
1852 }
1853
1854 return ret;
1855 }
1856
1857 static const struct sci_irq_desc {
1858 const char *desc;
1859 irq_handler_t handler;
1860 } sci_irq_desc[] = {
1861 /*
1862 * Split out handlers, the default case.
1863 */
1864 [SCIx_ERI_IRQ] = {
1865 .desc = "rx err",
1866 .handler = sci_er_interrupt,
1867 },
1868
1869 [SCIx_RXI_IRQ] = {
1870 .desc = "rx full",
1871 .handler = sci_rx_interrupt,
1872 },
1873
1874 [SCIx_TXI_IRQ] = {
1875 .desc = "tx empty",
1876 .handler = sci_tx_interrupt,
1877 },
1878
1879 [SCIx_BRI_IRQ] = {
1880 .desc = "break",
1881 .handler = sci_br_interrupt,
1882 },
1883
1884 [SCIx_DRI_IRQ] = {
1885 .desc = "rx ready",
1886 .handler = sci_rx_interrupt,
1887 },
1888
1889 [SCIx_TEI_IRQ] = {
1890 .desc = "tx end",
1891 .handler = sci_tx_interrupt,
1892 },
1893
1894 /*
1895 * Special muxed handler.
1896 */
1897 [SCIx_MUX_IRQ] = {
1898 .desc = "mux",
1899 .handler = sci_mpxed_interrupt,
1900 },
1901 };
1902
sci_request_irq(struct sci_port * port)1903 static int sci_request_irq(struct sci_port *port)
1904 {
1905 struct uart_port *up = &port->port;
1906 int i, j, w, ret = 0;
1907
1908 for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1909 const struct sci_irq_desc *desc;
1910 int irq;
1911
1912 /* Check if already registered (muxed) */
1913 for (w = 0; w < i; w++)
1914 if (port->irqs[w] == port->irqs[i])
1915 w = i + 1;
1916 if (w > i)
1917 continue;
1918
1919 if (SCIx_IRQ_IS_MUXED(port)) {
1920 i = SCIx_MUX_IRQ;
1921 irq = up->irq;
1922 } else {
1923 irq = port->irqs[i];
1924
1925 /*
1926 * Certain port types won't support all of the
1927 * available interrupt sources.
1928 */
1929 if (unlikely(irq < 0))
1930 continue;
1931 }
1932
1933 desc = sci_irq_desc + i;
1934 port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1935 dev_name(up->dev), desc->desc);
1936 if (!port->irqstr[j]) {
1937 ret = -ENOMEM;
1938 goto out_nomem;
1939 }
1940
1941 ret = request_irq(irq, desc->handler, up->irqflags,
1942 port->irqstr[j], port);
1943 if (unlikely(ret)) {
1944 dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1945 goto out_noirq;
1946 }
1947 }
1948
1949 return 0;
1950
1951 out_noirq:
1952 while (--i >= 0)
1953 free_irq(port->irqs[i], port);
1954
1955 out_nomem:
1956 while (--j >= 0)
1957 kfree(port->irqstr[j]);
1958
1959 return ret;
1960 }
1961
sci_free_irq(struct sci_port * port)1962 static void sci_free_irq(struct sci_port *port)
1963 {
1964 int i, j;
1965
1966 /*
1967 * Intentionally in reverse order so we iterate over the muxed
1968 * IRQ first.
1969 */
1970 for (i = 0; i < SCIx_NR_IRQS; i++) {
1971 int irq = port->irqs[i];
1972
1973 /*
1974 * Certain port types won't support all of the available
1975 * interrupt sources.
1976 */
1977 if (unlikely(irq < 0))
1978 continue;
1979
1980 /* Check if already freed (irq was muxed) */
1981 for (j = 0; j < i; j++)
1982 if (port->irqs[j] == irq)
1983 j = i + 1;
1984 if (j > i)
1985 continue;
1986
1987 free_irq(port->irqs[i], port);
1988 kfree(port->irqstr[i]);
1989
1990 if (SCIx_IRQ_IS_MUXED(port)) {
1991 /* If there's only one IRQ, we're done. */
1992 return;
1993 }
1994 }
1995 }
1996
sci_tx_empty(struct uart_port * port)1997 static unsigned int sci_tx_empty(struct uart_port *port)
1998 {
1999 unsigned short status = serial_port_in(port, SCxSR);
2000 unsigned short in_tx_fifo = sci_txfill(port);
2001
2002 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2003 }
2004
sci_set_rts(struct uart_port * port,bool state)2005 static void sci_set_rts(struct uart_port *port, bool state)
2006 {
2007 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2008 u16 data = serial_port_in(port, SCPDR);
2009
2010 /* Active low */
2011 if (state)
2012 data &= ~SCPDR_RTSD;
2013 else
2014 data |= SCPDR_RTSD;
2015 serial_port_out(port, SCPDR, data);
2016
2017 /* RTS# is output */
2018 serial_port_out(port, SCPCR,
2019 serial_port_in(port, SCPCR) | SCPCR_RTSC);
2020 } else if (sci_getreg(port, SCSPTR)->size) {
2021 u16 ctrl = serial_port_in(port, SCSPTR);
2022
2023 /* Active low */
2024 if (state)
2025 ctrl &= ~SCSPTR_RTSDT;
2026 else
2027 ctrl |= SCSPTR_RTSDT;
2028 serial_port_out(port, SCSPTR, ctrl);
2029 }
2030 }
2031
sci_get_cts(struct uart_port * port)2032 static bool sci_get_cts(struct uart_port *port)
2033 {
2034 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2035 /* Active low */
2036 return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2037 } else if (sci_getreg(port, SCSPTR)->size) {
2038 /* Active low */
2039 return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2040 }
2041
2042 return true;
2043 }
2044
2045 /*
2046 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2047 * CTS/RTS is supported in hardware by at least one port and controlled
2048 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2049 * handled via the ->init_pins() op, which is a bit of a one-way street,
2050 * lacking any ability to defer pin control -- this will later be
2051 * converted over to the GPIO framework).
2052 *
2053 * Other modes (such as loopback) are supported generically on certain
2054 * port types, but not others. For these it's sufficient to test for the
2055 * existence of the support register and simply ignore the port type.
2056 */
sci_set_mctrl(struct uart_port * port,unsigned int mctrl)2057 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2058 {
2059 struct sci_port *s = to_sci_port(port);
2060
2061 if (mctrl & TIOCM_LOOP) {
2062 const struct plat_sci_reg *reg;
2063
2064 /*
2065 * Standard loopback mode for SCFCR ports.
2066 */
2067 reg = sci_getreg(port, SCFCR);
2068 if (reg->size)
2069 serial_port_out(port, SCFCR,
2070 serial_port_in(port, SCFCR) |
2071 SCFCR_LOOP);
2072 }
2073
2074 mctrl_gpio_set(s->gpios, mctrl);
2075
2076 if (!s->has_rtscts)
2077 return;
2078
2079 if (!(mctrl & TIOCM_RTS)) {
2080 /* Disable Auto RTS */
2081 serial_port_out(port, SCFCR,
2082 serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2083
2084 /* Clear RTS */
2085 sci_set_rts(port, 0);
2086 } else if (s->autorts) {
2087 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2088 /* Enable RTS# pin function */
2089 serial_port_out(port, SCPCR,
2090 serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2091 }
2092
2093 /* Enable Auto RTS */
2094 serial_port_out(port, SCFCR,
2095 serial_port_in(port, SCFCR) | SCFCR_MCE);
2096 } else {
2097 /* Set RTS */
2098 sci_set_rts(port, 1);
2099 }
2100 }
2101
sci_get_mctrl(struct uart_port * port)2102 static unsigned int sci_get_mctrl(struct uart_port *port)
2103 {
2104 struct sci_port *s = to_sci_port(port);
2105 struct mctrl_gpios *gpios = s->gpios;
2106 unsigned int mctrl = 0;
2107
2108 mctrl_gpio_get(gpios, &mctrl);
2109
2110 /*
2111 * CTS/RTS is handled in hardware when supported, while nothing
2112 * else is wired up.
2113 */
2114 if (s->autorts) {
2115 if (sci_get_cts(port))
2116 mctrl |= TIOCM_CTS;
2117 } else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2118 mctrl |= TIOCM_CTS;
2119 }
2120 if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2121 mctrl |= TIOCM_DSR;
2122 if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2123 mctrl |= TIOCM_CAR;
2124
2125 return mctrl;
2126 }
2127
sci_enable_ms(struct uart_port * port)2128 static void sci_enable_ms(struct uart_port *port)
2129 {
2130 mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2131 }
2132
sci_break_ctl(struct uart_port * port,int break_state)2133 static void sci_break_ctl(struct uart_port *port, int break_state)
2134 {
2135 unsigned short scscr, scsptr;
2136 unsigned long flags;
2137
2138 /* check whether the port has SCSPTR */
2139 if (!sci_getreg(port, SCSPTR)->size) {
2140 /*
2141 * Not supported by hardware. Most parts couple break and rx
2142 * interrupts together, with break detection always enabled.
2143 */
2144 return;
2145 }
2146
2147 spin_lock_irqsave(&port->lock, flags);
2148 scsptr = serial_port_in(port, SCSPTR);
2149 scscr = serial_port_in(port, SCSCR);
2150
2151 if (break_state == -1) {
2152 scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2153 scscr &= ~SCSCR_TE;
2154 } else {
2155 scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2156 scscr |= SCSCR_TE;
2157 }
2158
2159 serial_port_out(port, SCSPTR, scsptr);
2160 serial_port_out(port, SCSCR, scscr);
2161 spin_unlock_irqrestore(&port->lock, flags);
2162 }
2163
sci_startup(struct uart_port * port)2164 static int sci_startup(struct uart_port *port)
2165 {
2166 struct sci_port *s = to_sci_port(port);
2167 int ret;
2168
2169 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2170
2171 sci_request_dma(port);
2172
2173 ret = sci_request_irq(s);
2174 if (unlikely(ret < 0)) {
2175 sci_free_dma(port);
2176 return ret;
2177 }
2178
2179 return 0;
2180 }
2181
sci_shutdown(struct uart_port * port)2182 static void sci_shutdown(struct uart_port *port)
2183 {
2184 struct sci_port *s = to_sci_port(port);
2185 unsigned long flags;
2186 u16 scr;
2187
2188 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2189
2190 s->autorts = false;
2191 mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2192
2193 spin_lock_irqsave(&port->lock, flags);
2194 sci_stop_rx(port);
2195 sci_stop_tx(port);
2196 /*
2197 * Stop RX and TX, disable related interrupts, keep clock source
2198 * and HSCIF TOT bits
2199 */
2200 scr = serial_port_in(port, SCSCR);
2201 serial_port_out(port, SCSCR, scr &
2202 (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2203 spin_unlock_irqrestore(&port->lock, flags);
2204
2205 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2206 if (s->chan_rx_saved) {
2207 dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2208 port->line);
2209 hrtimer_cancel(&s->rx_timer);
2210 }
2211 #endif
2212
2213 if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2214 del_timer_sync(&s->rx_fifo_timer);
2215 sci_free_irq(s);
2216 sci_free_dma(port);
2217 }
2218
sci_sck_calc(struct sci_port * s,unsigned int bps,unsigned int * srr)2219 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2220 unsigned int *srr)
2221 {
2222 unsigned long freq = s->clk_rates[SCI_SCK];
2223 int err, min_err = INT_MAX;
2224 unsigned int sr;
2225
2226 if (s->port.type != PORT_HSCIF)
2227 freq *= 2;
2228
2229 for_each_sr(sr, s) {
2230 err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2231 if (abs(err) >= abs(min_err))
2232 continue;
2233
2234 min_err = err;
2235 *srr = sr - 1;
2236
2237 if (!err)
2238 break;
2239 }
2240
2241 dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2242 *srr + 1);
2243 return min_err;
2244 }
2245
sci_brg_calc(struct sci_port * s,unsigned int bps,unsigned long freq,unsigned int * dlr,unsigned int * srr)2246 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2247 unsigned long freq, unsigned int *dlr,
2248 unsigned int *srr)
2249 {
2250 int err, min_err = INT_MAX;
2251 unsigned int sr, dl;
2252
2253 if (s->port.type != PORT_HSCIF)
2254 freq *= 2;
2255
2256 for_each_sr(sr, s) {
2257 dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2258 dl = clamp(dl, 1U, 65535U);
2259
2260 err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2261 if (abs(err) >= abs(min_err))
2262 continue;
2263
2264 min_err = err;
2265 *dlr = dl;
2266 *srr = sr - 1;
2267
2268 if (!err)
2269 break;
2270 }
2271
2272 dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2273 min_err, *dlr, *srr + 1);
2274 return min_err;
2275 }
2276
2277 /* calculate sample rate, BRR, and clock select */
sci_scbrr_calc(struct sci_port * s,unsigned int bps,unsigned int * brr,unsigned int * srr,unsigned int * cks)2278 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2279 unsigned int *brr, unsigned int *srr,
2280 unsigned int *cks)
2281 {
2282 unsigned long freq = s->clk_rates[SCI_FCK];
2283 unsigned int sr, br, prediv, scrate, c;
2284 int err, min_err = INT_MAX;
2285
2286 if (s->port.type != PORT_HSCIF)
2287 freq *= 2;
2288
2289 /*
2290 * Find the combination of sample rate and clock select with the
2291 * smallest deviation from the desired baud rate.
2292 * Prefer high sample rates to maximise the receive margin.
2293 *
2294 * M: Receive margin (%)
2295 * N: Ratio of bit rate to clock (N = sampling rate)
2296 * D: Clock duty (D = 0 to 1.0)
2297 * L: Frame length (L = 9 to 12)
2298 * F: Absolute value of clock frequency deviation
2299 *
2300 * M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2301 * (|D - 0.5| / N * (1 + F))|
2302 * NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2303 */
2304 for_each_sr(sr, s) {
2305 for (c = 0; c <= 3; c++) {
2306 /* integerized formulas from HSCIF documentation */
2307 prediv = sr * (1 << (2 * c + 1));
2308
2309 /*
2310 * We need to calculate:
2311 *
2312 * br = freq / (prediv * bps) clamped to [1..256]
2313 * err = freq / (br * prediv) - bps
2314 *
2315 * Watch out for overflow when calculating the desired
2316 * sampling clock rate!
2317 */
2318 if (bps > UINT_MAX / prediv)
2319 break;
2320
2321 scrate = prediv * bps;
2322 br = DIV_ROUND_CLOSEST(freq, scrate);
2323 br = clamp(br, 1U, 256U);
2324
2325 err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2326 if (abs(err) >= abs(min_err))
2327 continue;
2328
2329 min_err = err;
2330 *brr = br - 1;
2331 *srr = sr - 1;
2332 *cks = c;
2333
2334 if (!err)
2335 goto found;
2336 }
2337 }
2338
2339 found:
2340 dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2341 min_err, *brr, *srr + 1, *cks);
2342 return min_err;
2343 }
2344
sci_reset(struct uart_port * port)2345 static void sci_reset(struct uart_port *port)
2346 {
2347 const struct plat_sci_reg *reg;
2348 unsigned int status;
2349 struct sci_port *s = to_sci_port(port);
2350
2351 serial_port_out(port, SCSCR, s->hscif_tot); /* TE=0, RE=0, CKE1=0 */
2352
2353 reg = sci_getreg(port, SCFCR);
2354 if (reg->size)
2355 serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2356
2357 sci_clear_SCxSR(port,
2358 SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2359 SCxSR_BREAK_CLEAR(port));
2360 if (sci_getreg(port, SCLSR)->size) {
2361 status = serial_port_in(port, SCLSR);
2362 status &= ~(SCLSR_TO | SCLSR_ORER);
2363 serial_port_out(port, SCLSR, status);
2364 }
2365
2366 if (s->rx_trigger > 1) {
2367 if (s->rx_fifo_timeout) {
2368 scif_set_rtrg(port, 1);
2369 timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2370 } else {
2371 if (port->type == PORT_SCIFA ||
2372 port->type == PORT_SCIFB)
2373 scif_set_rtrg(port, 1);
2374 else
2375 scif_set_rtrg(port, s->rx_trigger);
2376 }
2377 }
2378 }
2379
sci_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)2380 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2381 struct ktermios *old)
2382 {
2383 unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2384 unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2385 unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2386 struct sci_port *s = to_sci_port(port);
2387 const struct plat_sci_reg *reg;
2388 int min_err = INT_MAX, err;
2389 unsigned long max_freq = 0;
2390 int best_clk = -1;
2391 unsigned long flags;
2392
2393 if ((termios->c_cflag & CSIZE) == CS7)
2394 smr_val |= SCSMR_CHR;
2395 if (termios->c_cflag & PARENB)
2396 smr_val |= SCSMR_PE;
2397 if (termios->c_cflag & PARODD)
2398 smr_val |= SCSMR_PE | SCSMR_ODD;
2399 if (termios->c_cflag & CSTOPB)
2400 smr_val |= SCSMR_STOP;
2401
2402 /*
2403 * earlyprintk comes here early on with port->uartclk set to zero.
2404 * the clock framework is not up and running at this point so here
2405 * we assume that 115200 is the maximum baud rate. please note that
2406 * the baud rate is not programmed during earlyprintk - it is assumed
2407 * that the previous boot loader has enabled required clocks and
2408 * setup the baud rate generator hardware for us already.
2409 */
2410 if (!port->uartclk) {
2411 baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2412 goto done;
2413 }
2414
2415 for (i = 0; i < SCI_NUM_CLKS; i++)
2416 max_freq = max(max_freq, s->clk_rates[i]);
2417
2418 baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2419 if (!baud)
2420 goto done;
2421
2422 /*
2423 * There can be multiple sources for the sampling clock. Find the one
2424 * that gives us the smallest deviation from the desired baud rate.
2425 */
2426
2427 /* Optional Undivided External Clock */
2428 if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2429 port->type != PORT_SCIFB) {
2430 err = sci_sck_calc(s, baud, &srr1);
2431 if (abs(err) < abs(min_err)) {
2432 best_clk = SCI_SCK;
2433 scr_val = SCSCR_CKE1;
2434 sccks = SCCKS_CKS;
2435 min_err = err;
2436 srr = srr1;
2437 if (!err)
2438 goto done;
2439 }
2440 }
2441
2442 /* Optional BRG Frequency Divided External Clock */
2443 if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2444 err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2445 &srr1);
2446 if (abs(err) < abs(min_err)) {
2447 best_clk = SCI_SCIF_CLK;
2448 scr_val = SCSCR_CKE1;
2449 sccks = 0;
2450 min_err = err;
2451 dl = dl1;
2452 srr = srr1;
2453 if (!err)
2454 goto done;
2455 }
2456 }
2457
2458 /* Optional BRG Frequency Divided Internal Clock */
2459 if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2460 err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2461 &srr1);
2462 if (abs(err) < abs(min_err)) {
2463 best_clk = SCI_BRG_INT;
2464 scr_val = SCSCR_CKE1;
2465 sccks = SCCKS_XIN;
2466 min_err = err;
2467 dl = dl1;
2468 srr = srr1;
2469 if (!min_err)
2470 goto done;
2471 }
2472 }
2473
2474 /* Divided Functional Clock using standard Bit Rate Register */
2475 err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2476 if (abs(err) < abs(min_err)) {
2477 best_clk = SCI_FCK;
2478 scr_val = 0;
2479 min_err = err;
2480 brr = brr1;
2481 srr = srr1;
2482 cks = cks1;
2483 }
2484
2485 done:
2486 if (best_clk >= 0)
2487 dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2488 s->clks[best_clk], baud, min_err);
2489
2490 sci_port_enable(s);
2491
2492 /*
2493 * Program the optional External Baud Rate Generator (BRG) first.
2494 * It controls the mux to select (H)SCK or frequency divided clock.
2495 */
2496 if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2497 serial_port_out(port, SCDL, dl);
2498 serial_port_out(port, SCCKS, sccks);
2499 }
2500
2501 spin_lock_irqsave(&port->lock, flags);
2502
2503 sci_reset(port);
2504
2505 uart_update_timeout(port, termios->c_cflag, baud);
2506
2507 /* byte size and parity */
2508 bits = tty_get_frame_size(termios->c_cflag);
2509
2510 if (sci_getreg(port, SEMR)->size)
2511 serial_port_out(port, SEMR, 0);
2512
2513 if (best_clk >= 0) {
2514 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2515 switch (srr + 1) {
2516 case 5: smr_val |= SCSMR_SRC_5; break;
2517 case 7: smr_val |= SCSMR_SRC_7; break;
2518 case 11: smr_val |= SCSMR_SRC_11; break;
2519 case 13: smr_val |= SCSMR_SRC_13; break;
2520 case 16: smr_val |= SCSMR_SRC_16; break;
2521 case 17: smr_val |= SCSMR_SRC_17; break;
2522 case 19: smr_val |= SCSMR_SRC_19; break;
2523 case 27: smr_val |= SCSMR_SRC_27; break;
2524 }
2525 smr_val |= cks;
2526 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2527 serial_port_out(port, SCSMR, smr_val);
2528 serial_port_out(port, SCBRR, brr);
2529 if (sci_getreg(port, HSSRR)->size) {
2530 unsigned int hssrr = srr | HSCIF_SRE;
2531 /* Calculate deviation from intended rate at the
2532 * center of the last stop bit in sampling clocks.
2533 */
2534 int last_stop = bits * 2 - 1;
2535 int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2536 (int)(srr + 1),
2537 2 * (int)baud);
2538
2539 if (abs(deviation) >= 2) {
2540 /* At least two sampling clocks off at the
2541 * last stop bit; we can increase the error
2542 * margin by shifting the sampling point.
2543 */
2544 int shift = clamp(deviation / 2, -8, 7);
2545
2546 hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2547 HSCIF_SRHP_MASK;
2548 hssrr |= HSCIF_SRDE;
2549 }
2550 serial_port_out(port, HSSRR, hssrr);
2551 }
2552
2553 /* Wait one bit interval */
2554 udelay((1000000 + (baud - 1)) / baud);
2555 } else {
2556 /* Don't touch the bit rate configuration */
2557 scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2558 smr_val |= serial_port_in(port, SCSMR) &
2559 (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2560 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2561 serial_port_out(port, SCSMR, smr_val);
2562 }
2563
2564 sci_init_pins(port, termios->c_cflag);
2565
2566 port->status &= ~UPSTAT_AUTOCTS;
2567 s->autorts = false;
2568 reg = sci_getreg(port, SCFCR);
2569 if (reg->size) {
2570 unsigned short ctrl = serial_port_in(port, SCFCR);
2571
2572 if ((port->flags & UPF_HARD_FLOW) &&
2573 (termios->c_cflag & CRTSCTS)) {
2574 /* There is no CTS interrupt to restart the hardware */
2575 port->status |= UPSTAT_AUTOCTS;
2576 /* MCE is enabled when RTS is raised */
2577 s->autorts = true;
2578 }
2579
2580 /*
2581 * As we've done a sci_reset() above, ensure we don't
2582 * interfere with the FIFOs while toggling MCE. As the
2583 * reset values could still be set, simply mask them out.
2584 */
2585 ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2586
2587 serial_port_out(port, SCFCR, ctrl);
2588 }
2589 if (port->flags & UPF_HARD_FLOW) {
2590 /* Refresh (Auto) RTS */
2591 sci_set_mctrl(port, port->mctrl);
2592 }
2593
2594 scr_val |= SCSCR_RE | SCSCR_TE |
2595 (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2596 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2597 if ((srr + 1 == 5) &&
2598 (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2599 /*
2600 * In asynchronous mode, when the sampling rate is 1/5, first
2601 * received data may become invalid on some SCIFA and SCIFB.
2602 * To avoid this problem wait more than 1 serial data time (1
2603 * bit time x serial data number) after setting SCSCR.RE = 1.
2604 */
2605 udelay(DIV_ROUND_UP(10 * 1000000, baud));
2606 }
2607
2608 /* Calculate delay for 2 DMA buffers (4 FIFO). */
2609 s->rx_frame = (10000 * bits) / (baud / 100);
2610 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2611 s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2612 #endif
2613
2614 if ((termios->c_cflag & CREAD) != 0)
2615 sci_start_rx(port);
2616
2617 spin_unlock_irqrestore(&port->lock, flags);
2618
2619 sci_port_disable(s);
2620
2621 if (UART_ENABLE_MS(port, termios->c_cflag))
2622 sci_enable_ms(port);
2623 }
2624
sci_pm(struct uart_port * port,unsigned int state,unsigned int oldstate)2625 static void sci_pm(struct uart_port *port, unsigned int state,
2626 unsigned int oldstate)
2627 {
2628 struct sci_port *sci_port = to_sci_port(port);
2629
2630 switch (state) {
2631 case UART_PM_STATE_OFF:
2632 sci_port_disable(sci_port);
2633 break;
2634 default:
2635 sci_port_enable(sci_port);
2636 break;
2637 }
2638 }
2639
sci_type(struct uart_port * port)2640 static const char *sci_type(struct uart_port *port)
2641 {
2642 switch (port->type) {
2643 case PORT_IRDA:
2644 return "irda";
2645 case PORT_SCI:
2646 return "sci";
2647 case PORT_SCIF:
2648 return "scif";
2649 case PORT_SCIFA:
2650 return "scifa";
2651 case PORT_SCIFB:
2652 return "scifb";
2653 case PORT_HSCIF:
2654 return "hscif";
2655 }
2656
2657 return NULL;
2658 }
2659
sci_remap_port(struct uart_port * port)2660 static int sci_remap_port(struct uart_port *port)
2661 {
2662 struct sci_port *sport = to_sci_port(port);
2663
2664 /*
2665 * Nothing to do if there's already an established membase.
2666 */
2667 if (port->membase)
2668 return 0;
2669
2670 if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2671 port->membase = ioremap(port->mapbase, sport->reg_size);
2672 if (unlikely(!port->membase)) {
2673 dev_err(port->dev, "can't remap port#%d\n", port->line);
2674 return -ENXIO;
2675 }
2676 } else {
2677 /*
2678 * For the simple (and majority of) cases where we don't
2679 * need to do any remapping, just cast the cookie
2680 * directly.
2681 */
2682 port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2683 }
2684
2685 return 0;
2686 }
2687
sci_release_port(struct uart_port * port)2688 static void sci_release_port(struct uart_port *port)
2689 {
2690 struct sci_port *sport = to_sci_port(port);
2691
2692 if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2693 iounmap(port->membase);
2694 port->membase = NULL;
2695 }
2696
2697 release_mem_region(port->mapbase, sport->reg_size);
2698 }
2699
sci_request_port(struct uart_port * port)2700 static int sci_request_port(struct uart_port *port)
2701 {
2702 struct resource *res;
2703 struct sci_port *sport = to_sci_port(port);
2704 int ret;
2705
2706 res = request_mem_region(port->mapbase, sport->reg_size,
2707 dev_name(port->dev));
2708 if (unlikely(res == NULL)) {
2709 dev_err(port->dev, "request_mem_region failed.");
2710 return -EBUSY;
2711 }
2712
2713 ret = sci_remap_port(port);
2714 if (unlikely(ret != 0)) {
2715 release_resource(res);
2716 return ret;
2717 }
2718
2719 return 0;
2720 }
2721
sci_config_port(struct uart_port * port,int flags)2722 static void sci_config_port(struct uart_port *port, int flags)
2723 {
2724 if (flags & UART_CONFIG_TYPE) {
2725 struct sci_port *sport = to_sci_port(port);
2726
2727 port->type = sport->cfg->type;
2728 sci_request_port(port);
2729 }
2730 }
2731
sci_verify_port(struct uart_port * port,struct serial_struct * ser)2732 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2733 {
2734 if (ser->baud_base < 2400)
2735 /* No paper tape reader for Mitch.. */
2736 return -EINVAL;
2737
2738 return 0;
2739 }
2740
2741 static const struct uart_ops sci_uart_ops = {
2742 .tx_empty = sci_tx_empty,
2743 .set_mctrl = sci_set_mctrl,
2744 .get_mctrl = sci_get_mctrl,
2745 .start_tx = sci_start_tx,
2746 .stop_tx = sci_stop_tx,
2747 .stop_rx = sci_stop_rx,
2748 .enable_ms = sci_enable_ms,
2749 .break_ctl = sci_break_ctl,
2750 .startup = sci_startup,
2751 .shutdown = sci_shutdown,
2752 .flush_buffer = sci_flush_buffer,
2753 .set_termios = sci_set_termios,
2754 .pm = sci_pm,
2755 .type = sci_type,
2756 .release_port = sci_release_port,
2757 .request_port = sci_request_port,
2758 .config_port = sci_config_port,
2759 .verify_port = sci_verify_port,
2760 #ifdef CONFIG_CONSOLE_POLL
2761 .poll_get_char = sci_poll_get_char,
2762 .poll_put_char = sci_poll_put_char,
2763 #endif
2764 };
2765
sci_init_clocks(struct sci_port * sci_port,struct device * dev)2766 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2767 {
2768 const char *clk_names[] = {
2769 [SCI_FCK] = "fck",
2770 [SCI_SCK] = "sck",
2771 [SCI_BRG_INT] = "brg_int",
2772 [SCI_SCIF_CLK] = "scif_clk",
2773 };
2774 struct clk *clk;
2775 unsigned int i;
2776
2777 if (sci_port->cfg->type == PORT_HSCIF)
2778 clk_names[SCI_SCK] = "hsck";
2779
2780 for (i = 0; i < SCI_NUM_CLKS; i++) {
2781 clk = devm_clk_get(dev, clk_names[i]);
2782 if (PTR_ERR(clk) == -EPROBE_DEFER)
2783 return -EPROBE_DEFER;
2784
2785 if (IS_ERR(clk) && i == SCI_FCK) {
2786 /*
2787 * "fck" used to be called "sci_ick", and we need to
2788 * maintain DT backward compatibility.
2789 */
2790 clk = devm_clk_get(dev, "sci_ick");
2791 if (PTR_ERR(clk) == -EPROBE_DEFER)
2792 return -EPROBE_DEFER;
2793
2794 if (!IS_ERR(clk))
2795 goto found;
2796
2797 /*
2798 * Not all SH platforms declare a clock lookup entry
2799 * for SCI devices, in which case we need to get the
2800 * global "peripheral_clk" clock.
2801 */
2802 clk = devm_clk_get(dev, "peripheral_clk");
2803 if (!IS_ERR(clk))
2804 goto found;
2805
2806 dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2807 PTR_ERR(clk));
2808 return PTR_ERR(clk);
2809 }
2810
2811 found:
2812 if (IS_ERR(clk))
2813 dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2814 PTR_ERR(clk));
2815 else
2816 dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2817 clk, clk_get_rate(clk));
2818 sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2819 }
2820 return 0;
2821 }
2822
2823 static const struct sci_port_params *
sci_probe_regmap(const struct plat_sci_port * cfg)2824 sci_probe_regmap(const struct plat_sci_port *cfg)
2825 {
2826 unsigned int regtype;
2827
2828 if (cfg->regtype != SCIx_PROBE_REGTYPE)
2829 return &sci_port_params[cfg->regtype];
2830
2831 switch (cfg->type) {
2832 case PORT_SCI:
2833 regtype = SCIx_SCI_REGTYPE;
2834 break;
2835 case PORT_IRDA:
2836 regtype = SCIx_IRDA_REGTYPE;
2837 break;
2838 case PORT_SCIFA:
2839 regtype = SCIx_SCIFA_REGTYPE;
2840 break;
2841 case PORT_SCIFB:
2842 regtype = SCIx_SCIFB_REGTYPE;
2843 break;
2844 case PORT_SCIF:
2845 /*
2846 * The SH-4 is a bit of a misnomer here, although that's
2847 * where this particular port layout originated. This
2848 * configuration (or some slight variation thereof)
2849 * remains the dominant model for all SCIFs.
2850 */
2851 regtype = SCIx_SH4_SCIF_REGTYPE;
2852 break;
2853 case PORT_HSCIF:
2854 regtype = SCIx_HSCIF_REGTYPE;
2855 break;
2856 default:
2857 pr_err("Can't probe register map for given port\n");
2858 return NULL;
2859 }
2860
2861 return &sci_port_params[regtype];
2862 }
2863
sci_init_single(struct platform_device * dev,struct sci_port * sci_port,unsigned int index,const struct plat_sci_port * p,bool early)2864 static int sci_init_single(struct platform_device *dev,
2865 struct sci_port *sci_port, unsigned int index,
2866 const struct plat_sci_port *p, bool early)
2867 {
2868 struct uart_port *port = &sci_port->port;
2869 const struct resource *res;
2870 unsigned int i;
2871 int ret;
2872
2873 sci_port->cfg = p;
2874
2875 port->ops = &sci_uart_ops;
2876 port->iotype = UPIO_MEM;
2877 port->line = index;
2878 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2879
2880 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2881 if (res == NULL)
2882 return -ENOMEM;
2883
2884 port->mapbase = res->start;
2885 sci_port->reg_size = resource_size(res);
2886
2887 for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2888 if (i)
2889 sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2890 else
2891 sci_port->irqs[i] = platform_get_irq(dev, i);
2892 }
2893
2894 /* The SCI generates several interrupts. They can be muxed together or
2895 * connected to different interrupt lines. In the muxed case only one
2896 * interrupt resource is specified as there is only one interrupt ID.
2897 * In the non-muxed case, up to 6 interrupt signals might be generated
2898 * from the SCI, however those signals might have their own individual
2899 * interrupt ID numbers, or muxed together with another interrupt.
2900 */
2901 if (sci_port->irqs[0] < 0)
2902 return -ENXIO;
2903
2904 if (sci_port->irqs[1] < 0)
2905 for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2906 sci_port->irqs[i] = sci_port->irqs[0];
2907
2908 sci_port->params = sci_probe_regmap(p);
2909 if (unlikely(sci_port->params == NULL))
2910 return -EINVAL;
2911
2912 switch (p->type) {
2913 case PORT_SCIFB:
2914 sci_port->rx_trigger = 48;
2915 break;
2916 case PORT_HSCIF:
2917 sci_port->rx_trigger = 64;
2918 break;
2919 case PORT_SCIFA:
2920 sci_port->rx_trigger = 32;
2921 break;
2922 case PORT_SCIF:
2923 if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2924 /* RX triggering not implemented for this IP */
2925 sci_port->rx_trigger = 1;
2926 else
2927 sci_port->rx_trigger = 8;
2928 break;
2929 default:
2930 sci_port->rx_trigger = 1;
2931 break;
2932 }
2933
2934 sci_port->rx_fifo_timeout = 0;
2935 sci_port->hscif_tot = 0;
2936
2937 /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2938 * match the SoC datasheet, this should be investigated. Let platform
2939 * data override the sampling rate for now.
2940 */
2941 sci_port->sampling_rate_mask = p->sampling_rate
2942 ? SCI_SR(p->sampling_rate)
2943 : sci_port->params->sampling_rate_mask;
2944
2945 if (!early) {
2946 ret = sci_init_clocks(sci_port, &dev->dev);
2947 if (ret < 0)
2948 return ret;
2949
2950 port->dev = &dev->dev;
2951
2952 pm_runtime_enable(&dev->dev);
2953 }
2954
2955 port->type = p->type;
2956 port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2957 port->fifosize = sci_port->params->fifosize;
2958
2959 if (port->type == PORT_SCI) {
2960 if (sci_port->reg_size >= 0x20)
2961 port->regshift = 2;
2962 else
2963 port->regshift = 1;
2964 }
2965
2966 /*
2967 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2968 * for the multi-IRQ ports, which is where we are primarily
2969 * concerned with the shutdown path synchronization.
2970 *
2971 * For the muxed case there's nothing more to do.
2972 */
2973 port->irq = sci_port->irqs[SCIx_RXI_IRQ];
2974 port->irqflags = 0;
2975
2976 port->serial_in = sci_serial_in;
2977 port->serial_out = sci_serial_out;
2978
2979 return 0;
2980 }
2981
sci_cleanup_single(struct sci_port * port)2982 static void sci_cleanup_single(struct sci_port *port)
2983 {
2984 pm_runtime_disable(port->port.dev);
2985 }
2986
2987 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2988 defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
serial_console_putchar(struct uart_port * port,int ch)2989 static void serial_console_putchar(struct uart_port *port, int ch)
2990 {
2991 sci_poll_put_char(port, ch);
2992 }
2993
2994 /*
2995 * Print a string to the serial port trying not to disturb
2996 * any possible real use of the port...
2997 */
serial_console_write(struct console * co,const char * s,unsigned count)2998 static void serial_console_write(struct console *co, const char *s,
2999 unsigned count)
3000 {
3001 struct sci_port *sci_port = &sci_ports[co->index];
3002 struct uart_port *port = &sci_port->port;
3003 unsigned short bits, ctrl, ctrl_temp;
3004 unsigned long flags;
3005 int locked = 1;
3006
3007 if (port->sysrq)
3008 locked = 0;
3009 else if (oops_in_progress)
3010 locked = spin_trylock_irqsave(&port->lock, flags);
3011 else
3012 spin_lock_irqsave(&port->lock, flags);
3013
3014 /* first save SCSCR then disable interrupts, keep clock source */
3015 ctrl = serial_port_in(port, SCSCR);
3016 ctrl_temp = SCSCR_RE | SCSCR_TE |
3017 (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3018 (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3019 serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3020
3021 uart_console_write(port, s, count, serial_console_putchar);
3022
3023 /* wait until fifo is empty and last bit has been transmitted */
3024 bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3025 while ((serial_port_in(port, SCxSR) & bits) != bits)
3026 cpu_relax();
3027
3028 /* restore the SCSCR */
3029 serial_port_out(port, SCSCR, ctrl);
3030
3031 if (locked)
3032 spin_unlock_irqrestore(&port->lock, flags);
3033 }
3034
serial_console_setup(struct console * co,char * options)3035 static int serial_console_setup(struct console *co, char *options)
3036 {
3037 struct sci_port *sci_port;
3038 struct uart_port *port;
3039 int baud = 115200;
3040 int bits = 8;
3041 int parity = 'n';
3042 int flow = 'n';
3043 int ret;
3044
3045 /*
3046 * Refuse to handle any bogus ports.
3047 */
3048 if (co->index < 0 || co->index >= SCI_NPORTS)
3049 return -ENODEV;
3050
3051 sci_port = &sci_ports[co->index];
3052 port = &sci_port->port;
3053
3054 /*
3055 * Refuse to handle uninitialized ports.
3056 */
3057 if (!port->ops)
3058 return -ENODEV;
3059
3060 ret = sci_remap_port(port);
3061 if (unlikely(ret != 0))
3062 return ret;
3063
3064 if (options)
3065 uart_parse_options(options, &baud, &parity, &bits, &flow);
3066
3067 return uart_set_options(port, co, baud, parity, bits, flow);
3068 }
3069
3070 static struct console serial_console = {
3071 .name = "ttySC",
3072 .device = uart_console_device,
3073 .write = serial_console_write,
3074 .setup = serial_console_setup,
3075 .flags = CON_PRINTBUFFER,
3076 .index = -1,
3077 .data = &sci_uart_driver,
3078 };
3079
3080 #ifdef CONFIG_SUPERH
3081 static struct console early_serial_console = {
3082 .name = "early_ttySC",
3083 .write = serial_console_write,
3084 .flags = CON_PRINTBUFFER,
3085 .index = -1,
3086 };
3087
3088 static char early_serial_buf[32];
3089
sci_probe_earlyprintk(struct platform_device * pdev)3090 static int sci_probe_earlyprintk(struct platform_device *pdev)
3091 {
3092 const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3093
3094 if (early_serial_console.data)
3095 return -EEXIST;
3096
3097 early_serial_console.index = pdev->id;
3098
3099 sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3100
3101 serial_console_setup(&early_serial_console, early_serial_buf);
3102
3103 if (!strstr(early_serial_buf, "keep"))
3104 early_serial_console.flags |= CON_BOOT;
3105
3106 register_console(&early_serial_console);
3107 return 0;
3108 }
3109 #endif
3110
3111 #define SCI_CONSOLE (&serial_console)
3112
3113 #else
sci_probe_earlyprintk(struct platform_device * pdev)3114 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3115 {
3116 return -EINVAL;
3117 }
3118
3119 #define SCI_CONSOLE NULL
3120
3121 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3122
3123 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3124
3125 static DEFINE_MUTEX(sci_uart_registration_lock);
3126 static struct uart_driver sci_uart_driver = {
3127 .owner = THIS_MODULE,
3128 .driver_name = "sci",
3129 .dev_name = "ttySC",
3130 .major = SCI_MAJOR,
3131 .minor = SCI_MINOR_START,
3132 .nr = SCI_NPORTS,
3133 .cons = SCI_CONSOLE,
3134 };
3135
sci_remove(struct platform_device * dev)3136 static int sci_remove(struct platform_device *dev)
3137 {
3138 struct sci_port *port = platform_get_drvdata(dev);
3139 unsigned int type = port->port.type; /* uart_remove_... clears it */
3140
3141 sci_ports_in_use &= ~BIT(port->port.line);
3142 uart_remove_one_port(&sci_uart_driver, &port->port);
3143
3144 sci_cleanup_single(port);
3145
3146 if (port->port.fifosize > 1)
3147 device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3148 if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3149 device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3150
3151 return 0;
3152 }
3153
3154
3155 #define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
3156 #define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
3157 #define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
3158
3159 static const struct of_device_id of_sci_match[] = {
3160 /* SoC-specific types */
3161 {
3162 .compatible = "renesas,scif-r7s72100",
3163 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3164 },
3165 {
3166 .compatible = "renesas,scif-r7s9210",
3167 .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3168 },
3169 {
3170 .compatible = "renesas,scif-r9a07g044",
3171 .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3172 },
3173 /* Family-specific types */
3174 {
3175 .compatible = "renesas,rcar-gen1-scif",
3176 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3177 }, {
3178 .compatible = "renesas,rcar-gen2-scif",
3179 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3180 }, {
3181 .compatible = "renesas,rcar-gen3-scif",
3182 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3183 },
3184 /* Generic types */
3185 {
3186 .compatible = "renesas,scif",
3187 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3188 }, {
3189 .compatible = "renesas,scifa",
3190 .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3191 }, {
3192 .compatible = "renesas,scifb",
3193 .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3194 }, {
3195 .compatible = "renesas,hscif",
3196 .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3197 }, {
3198 .compatible = "renesas,sci",
3199 .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3200 }, {
3201 /* Terminator */
3202 },
3203 };
3204 MODULE_DEVICE_TABLE(of, of_sci_match);
3205
sci_parse_dt(struct platform_device * pdev,unsigned int * dev_id)3206 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3207 unsigned int *dev_id)
3208 {
3209 struct device_node *np = pdev->dev.of_node;
3210 struct plat_sci_port *p;
3211 struct sci_port *sp;
3212 const void *data;
3213 int id;
3214
3215 if (!IS_ENABLED(CONFIG_OF) || !np)
3216 return NULL;
3217
3218 data = of_device_get_match_data(&pdev->dev);
3219
3220 p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3221 if (!p)
3222 return NULL;
3223
3224 /* Get the line number from the aliases node. */
3225 id = of_alias_get_id(np, "serial");
3226 if (id < 0 && ~sci_ports_in_use)
3227 id = ffz(sci_ports_in_use);
3228 if (id < 0) {
3229 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3230 return NULL;
3231 }
3232 if (id >= ARRAY_SIZE(sci_ports)) {
3233 dev_err(&pdev->dev, "serial%d out of range\n", id);
3234 return NULL;
3235 }
3236
3237 sp = &sci_ports[id];
3238 *dev_id = id;
3239
3240 p->type = SCI_OF_TYPE(data);
3241 p->regtype = SCI_OF_REGTYPE(data);
3242
3243 sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3244
3245 return p;
3246 }
3247
sci_probe_single(struct platform_device * dev,unsigned int index,struct plat_sci_port * p,struct sci_port * sciport)3248 static int sci_probe_single(struct platform_device *dev,
3249 unsigned int index,
3250 struct plat_sci_port *p,
3251 struct sci_port *sciport)
3252 {
3253 int ret;
3254
3255 /* Sanity check */
3256 if (unlikely(index >= SCI_NPORTS)) {
3257 dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3258 index+1, SCI_NPORTS);
3259 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3260 return -EINVAL;
3261 }
3262 BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3263 if (sci_ports_in_use & BIT(index))
3264 return -EBUSY;
3265
3266 mutex_lock(&sci_uart_registration_lock);
3267 if (!sci_uart_driver.state) {
3268 ret = uart_register_driver(&sci_uart_driver);
3269 if (ret) {
3270 mutex_unlock(&sci_uart_registration_lock);
3271 return ret;
3272 }
3273 }
3274 mutex_unlock(&sci_uart_registration_lock);
3275
3276 ret = sci_init_single(dev, sciport, index, p, false);
3277 if (ret)
3278 return ret;
3279
3280 sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3281 if (IS_ERR(sciport->gpios))
3282 return PTR_ERR(sciport->gpios);
3283
3284 if (sciport->has_rtscts) {
3285 if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3286 mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3287 dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3288 return -EINVAL;
3289 }
3290 sciport->port.flags |= UPF_HARD_FLOW;
3291 }
3292
3293 ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3294 if (ret) {
3295 sci_cleanup_single(sciport);
3296 return ret;
3297 }
3298
3299 return 0;
3300 }
3301
sci_probe(struct platform_device * dev)3302 static int sci_probe(struct platform_device *dev)
3303 {
3304 struct plat_sci_port *p;
3305 struct sci_port *sp;
3306 unsigned int dev_id;
3307 int ret;
3308
3309 /*
3310 * If we've come here via earlyprintk initialization, head off to
3311 * the special early probe. We don't have sufficient device state
3312 * to make it beyond this yet.
3313 */
3314 #ifdef CONFIG_SUPERH
3315 if (is_sh_early_platform_device(dev))
3316 return sci_probe_earlyprintk(dev);
3317 #endif
3318
3319 if (dev->dev.of_node) {
3320 p = sci_parse_dt(dev, &dev_id);
3321 if (p == NULL)
3322 return -EINVAL;
3323 } else {
3324 p = dev->dev.platform_data;
3325 if (p == NULL) {
3326 dev_err(&dev->dev, "no platform data supplied\n");
3327 return -EINVAL;
3328 }
3329
3330 dev_id = dev->id;
3331 }
3332
3333 sp = &sci_ports[dev_id];
3334 platform_set_drvdata(dev, sp);
3335
3336 ret = sci_probe_single(dev, dev_id, p, sp);
3337 if (ret)
3338 return ret;
3339
3340 if (sp->port.fifosize > 1) {
3341 ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3342 if (ret)
3343 return ret;
3344 }
3345 if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3346 sp->port.type == PORT_HSCIF) {
3347 ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3348 if (ret) {
3349 if (sp->port.fifosize > 1) {
3350 device_remove_file(&dev->dev,
3351 &dev_attr_rx_fifo_trigger);
3352 }
3353 return ret;
3354 }
3355 }
3356
3357 #ifdef CONFIG_SH_STANDARD_BIOS
3358 sh_bios_gdb_detach();
3359 #endif
3360
3361 sci_ports_in_use |= BIT(dev_id);
3362 return 0;
3363 }
3364
sci_suspend(struct device * dev)3365 static __maybe_unused int sci_suspend(struct device *dev)
3366 {
3367 struct sci_port *sport = dev_get_drvdata(dev);
3368
3369 if (sport)
3370 uart_suspend_port(&sci_uart_driver, &sport->port);
3371
3372 return 0;
3373 }
3374
sci_resume(struct device * dev)3375 static __maybe_unused int sci_resume(struct device *dev)
3376 {
3377 struct sci_port *sport = dev_get_drvdata(dev);
3378
3379 if (sport)
3380 uart_resume_port(&sci_uart_driver, &sport->port);
3381
3382 return 0;
3383 }
3384
3385 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3386
3387 static struct platform_driver sci_driver = {
3388 .probe = sci_probe,
3389 .remove = sci_remove,
3390 .driver = {
3391 .name = "sh-sci",
3392 .pm = &sci_dev_pm_ops,
3393 .of_match_table = of_match_ptr(of_sci_match),
3394 },
3395 };
3396
sci_init(void)3397 static int __init sci_init(void)
3398 {
3399 pr_info("%s\n", banner);
3400
3401 return platform_driver_register(&sci_driver);
3402 }
3403
sci_exit(void)3404 static void __exit sci_exit(void)
3405 {
3406 platform_driver_unregister(&sci_driver);
3407
3408 if (sci_uart_driver.state)
3409 uart_unregister_driver(&sci_uart_driver);
3410 }
3411
3412 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3413 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3414 early_serial_buf, ARRAY_SIZE(early_serial_buf));
3415 #endif
3416 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3417 static struct plat_sci_port port_cfg __initdata;
3418
early_console_setup(struct earlycon_device * device,int type)3419 static int __init early_console_setup(struct earlycon_device *device,
3420 int type)
3421 {
3422 if (!device->port.membase)
3423 return -ENODEV;
3424
3425 device->port.serial_in = sci_serial_in;
3426 device->port.serial_out = sci_serial_out;
3427 device->port.type = type;
3428 memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3429 port_cfg.type = type;
3430 sci_ports[0].cfg = &port_cfg;
3431 sci_ports[0].params = sci_probe_regmap(&port_cfg);
3432 port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3433 sci_serial_out(&sci_ports[0].port, SCSCR,
3434 SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3435
3436 device->con->write = serial_console_write;
3437 return 0;
3438 }
sci_early_console_setup(struct earlycon_device * device,const char * opt)3439 static int __init sci_early_console_setup(struct earlycon_device *device,
3440 const char *opt)
3441 {
3442 return early_console_setup(device, PORT_SCI);
3443 }
scif_early_console_setup(struct earlycon_device * device,const char * opt)3444 static int __init scif_early_console_setup(struct earlycon_device *device,
3445 const char *opt)
3446 {
3447 return early_console_setup(device, PORT_SCIF);
3448 }
rzscifa_early_console_setup(struct earlycon_device * device,const char * opt)3449 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3450 const char *opt)
3451 {
3452 port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3453 return early_console_setup(device, PORT_SCIF);
3454 }
3455
scifa_early_console_setup(struct earlycon_device * device,const char * opt)3456 static int __init scifa_early_console_setup(struct earlycon_device *device,
3457 const char *opt)
3458 {
3459 return early_console_setup(device, PORT_SCIFA);
3460 }
scifb_early_console_setup(struct earlycon_device * device,const char * opt)3461 static int __init scifb_early_console_setup(struct earlycon_device *device,
3462 const char *opt)
3463 {
3464 return early_console_setup(device, PORT_SCIFB);
3465 }
hscif_early_console_setup(struct earlycon_device * device,const char * opt)3466 static int __init hscif_early_console_setup(struct earlycon_device *device,
3467 const char *opt)
3468 {
3469 return early_console_setup(device, PORT_HSCIF);
3470 }
3471
3472 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3473 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3474 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3475 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3476 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3477 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3478 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3479 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3480
3481 module_init(sci_init);
3482 module_exit(sci_exit);
3483
3484 MODULE_LICENSE("GPL");
3485 MODULE_ALIAS("platform:sh-sci");
3486 MODULE_AUTHOR("Paul Mundt");
3487 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3488
