1 // SPDX-License-Identifier: GPL-2.0
3 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
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).
9 * based off of the old drivers/char/sh-sci.c by:
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).
18 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
24 #include <linux/clk.h>
25 #include <linux/console.h>
26 #include <linux/ctype.h>
27 #include <linux/cpufreq.h>
28 #include <linux/delay.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/err.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/ioport.h>
36 #include <linux/major.h>
37 #include <linux/module.h>
40 #include <linux/of_device.h>
41 #include <linux/platform_device.h>
42 #include <linux/pm_runtime.h>
43 #include <linux/scatterlist.h>
44 #include <linux/serial.h>
45 #include <linux/serial_sci.h>
46 #include <linux/sh_dma.h>
47 #include <linux/slab.h>
48 #include <linux/string.h>
49 #include <linux/sysrq.h>
50 #include <linux/timer.h>
51 #include <linux/tty.h>
52 #include <linux/tty_flip.h>
55 #include <asm/sh_bios.h>
58 #include "serial_mctrl_gpio.h"
61 /* Offsets into the sci_port->irqs array */
69 SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */
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))
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 */
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)
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)
94 #define min_sr(_port) ffs((_port)->sampling_rate_mask)
95 #define max_sr(_port) fls((_port)->sampling_rate_mask)
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)))
102 struct plat_sci_reg {
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;
117 struct uart_port port;
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;
127 struct clk *clks[SCI_NUM_CLKS];
128 unsigned long clk_rates[SCI_NUM_CLKS];
130 int irqs[SCIx_NR_IRQS];
131 char *irqstr[SCIx_NR_IRQS];
133 struct dma_chan *chan_tx;
134 struct dma_chan *chan_rx;
136 #ifdef CONFIG_SERIAL_SH_SCI_DMA
137 dma_cookie_t cookie_tx;
138 dma_cookie_t cookie_rx[2];
139 dma_cookie_t active_rx;
140 dma_addr_t tx_dma_addr;
141 unsigned int tx_dma_len;
142 struct scatterlist sg_rx[2];
145 struct work_struct work_tx;
146 struct timer_list rx_timer;
147 unsigned int rx_timeout;
149 unsigned int rx_frame;
151 struct timer_list rx_fifo_timer;
159 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
161 static struct sci_port sci_ports[SCI_NPORTS];
162 static struct uart_driver sci_uart_driver;
164 static inline struct sci_port *
165 to_sci_port(struct uart_port *uart)
167 return container_of(uart, struct sci_port, port);
170 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
172 * Common SCI definitions, dependent on the port's regshift
175 [SCIx_SCI_REGTYPE] = {
177 [SCSMR] = { 0x00, 8 },
178 [SCBRR] = { 0x01, 8 },
179 [SCSCR] = { 0x02, 8 },
180 [SCxTDR] = { 0x03, 8 },
181 [SCxSR] = { 0x04, 8 },
182 [SCxRDR] = { 0x05, 8 },
185 .overrun_reg = SCxSR,
186 .overrun_mask = SCI_ORER,
187 .sampling_rate_mask = SCI_SR(32),
188 .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
189 .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
193 * Common definitions for legacy IrDA ports.
195 [SCIx_IRDA_REGTYPE] = {
197 [SCSMR] = { 0x00, 8 },
198 [SCBRR] = { 0x02, 8 },
199 [SCSCR] = { 0x04, 8 },
200 [SCxTDR] = { 0x06, 8 },
201 [SCxSR] = { 0x08, 16 },
202 [SCxRDR] = { 0x0a, 8 },
203 [SCFCR] = { 0x0c, 8 },
204 [SCFDR] = { 0x0e, 16 },
207 .overrun_reg = SCxSR,
208 .overrun_mask = SCI_ORER,
209 .sampling_rate_mask = SCI_SR(32),
210 .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
211 .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
215 * Common SCIFA definitions.
217 [SCIx_SCIFA_REGTYPE] = {
219 [SCSMR] = { 0x00, 16 },
220 [SCBRR] = { 0x04, 8 },
221 [SCSCR] = { 0x08, 16 },
222 [SCxTDR] = { 0x20, 8 },
223 [SCxSR] = { 0x14, 16 },
224 [SCxRDR] = { 0x24, 8 },
225 [SCFCR] = { 0x18, 16 },
226 [SCFDR] = { 0x1c, 16 },
227 [SCPCR] = { 0x30, 16 },
228 [SCPDR] = { 0x34, 16 },
231 .overrun_reg = SCxSR,
232 .overrun_mask = SCIFA_ORER,
233 .sampling_rate_mask = SCI_SR_SCIFAB,
234 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
235 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
239 * Common SCIFB definitions.
241 [SCIx_SCIFB_REGTYPE] = {
243 [SCSMR] = { 0x00, 16 },
244 [SCBRR] = { 0x04, 8 },
245 [SCSCR] = { 0x08, 16 },
246 [SCxTDR] = { 0x40, 8 },
247 [SCxSR] = { 0x14, 16 },
248 [SCxRDR] = { 0x60, 8 },
249 [SCFCR] = { 0x18, 16 },
250 [SCTFDR] = { 0x38, 16 },
251 [SCRFDR] = { 0x3c, 16 },
252 [SCPCR] = { 0x30, 16 },
253 [SCPDR] = { 0x34, 16 },
256 .overrun_reg = SCxSR,
257 .overrun_mask = SCIFA_ORER,
258 .sampling_rate_mask = SCI_SR_SCIFAB,
259 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
260 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
264 * Common SH-2(A) SCIF definitions for ports with FIFO data
267 [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
269 [SCSMR] = { 0x00, 16 },
270 [SCBRR] = { 0x04, 8 },
271 [SCSCR] = { 0x08, 16 },
272 [SCxTDR] = { 0x0c, 8 },
273 [SCxSR] = { 0x10, 16 },
274 [SCxRDR] = { 0x14, 8 },
275 [SCFCR] = { 0x18, 16 },
276 [SCFDR] = { 0x1c, 16 },
277 [SCSPTR] = { 0x20, 16 },
278 [SCLSR] = { 0x24, 16 },
281 .overrun_reg = SCLSR,
282 .overrun_mask = SCLSR_ORER,
283 .sampling_rate_mask = SCI_SR(32),
284 .error_mask = SCIF_DEFAULT_ERROR_MASK,
285 .error_clear = SCIF_ERROR_CLEAR,
289 * Common SH-3 SCIF definitions.
291 [SCIx_SH3_SCIF_REGTYPE] = {
293 [SCSMR] = { 0x00, 8 },
294 [SCBRR] = { 0x02, 8 },
295 [SCSCR] = { 0x04, 8 },
296 [SCxTDR] = { 0x06, 8 },
297 [SCxSR] = { 0x08, 16 },
298 [SCxRDR] = { 0x0a, 8 },
299 [SCFCR] = { 0x0c, 8 },
300 [SCFDR] = { 0x0e, 16 },
303 .overrun_reg = SCLSR,
304 .overrun_mask = SCLSR_ORER,
305 .sampling_rate_mask = SCI_SR(32),
306 .error_mask = SCIF_DEFAULT_ERROR_MASK,
307 .error_clear = SCIF_ERROR_CLEAR,
311 * Common SH-4(A) SCIF(B) definitions.
313 [SCIx_SH4_SCIF_REGTYPE] = {
315 [SCSMR] = { 0x00, 16 },
316 [SCBRR] = { 0x04, 8 },
317 [SCSCR] = { 0x08, 16 },
318 [SCxTDR] = { 0x0c, 8 },
319 [SCxSR] = { 0x10, 16 },
320 [SCxRDR] = { 0x14, 8 },
321 [SCFCR] = { 0x18, 16 },
322 [SCFDR] = { 0x1c, 16 },
323 [SCSPTR] = { 0x20, 16 },
324 [SCLSR] = { 0x24, 16 },
327 .overrun_reg = SCLSR,
328 .overrun_mask = SCLSR_ORER,
329 .sampling_rate_mask = SCI_SR(32),
330 .error_mask = SCIF_DEFAULT_ERROR_MASK,
331 .error_clear = SCIF_ERROR_CLEAR,
335 * Common SCIF definitions for ports with a Baud Rate Generator for
336 * External Clock (BRG).
338 [SCIx_SH4_SCIF_BRG_REGTYPE] = {
340 [SCSMR] = { 0x00, 16 },
341 [SCBRR] = { 0x04, 8 },
342 [SCSCR] = { 0x08, 16 },
343 [SCxTDR] = { 0x0c, 8 },
344 [SCxSR] = { 0x10, 16 },
345 [SCxRDR] = { 0x14, 8 },
346 [SCFCR] = { 0x18, 16 },
347 [SCFDR] = { 0x1c, 16 },
348 [SCSPTR] = { 0x20, 16 },
349 [SCLSR] = { 0x24, 16 },
350 [SCDL] = { 0x30, 16 },
351 [SCCKS] = { 0x34, 16 },
354 .overrun_reg = SCLSR,
355 .overrun_mask = SCLSR_ORER,
356 .sampling_rate_mask = SCI_SR(32),
357 .error_mask = SCIF_DEFAULT_ERROR_MASK,
358 .error_clear = SCIF_ERROR_CLEAR,
362 * Common HSCIF definitions.
364 [SCIx_HSCIF_REGTYPE] = {
366 [SCSMR] = { 0x00, 16 },
367 [SCBRR] = { 0x04, 8 },
368 [SCSCR] = { 0x08, 16 },
369 [SCxTDR] = { 0x0c, 8 },
370 [SCxSR] = { 0x10, 16 },
371 [SCxRDR] = { 0x14, 8 },
372 [SCFCR] = { 0x18, 16 },
373 [SCFDR] = { 0x1c, 16 },
374 [SCSPTR] = { 0x20, 16 },
375 [SCLSR] = { 0x24, 16 },
376 [HSSRR] = { 0x40, 16 },
377 [SCDL] = { 0x30, 16 },
378 [SCCKS] = { 0x34, 16 },
379 [HSRTRGR] = { 0x54, 16 },
380 [HSTTRGR] = { 0x58, 16 },
383 .overrun_reg = SCLSR,
384 .overrun_mask = SCLSR_ORER,
385 .sampling_rate_mask = SCI_SR_RANGE(8, 32),
386 .error_mask = SCIF_DEFAULT_ERROR_MASK,
387 .error_clear = SCIF_ERROR_CLEAR,
391 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
394 [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
396 [SCSMR] = { 0x00, 16 },
397 [SCBRR] = { 0x04, 8 },
398 [SCSCR] = { 0x08, 16 },
399 [SCxTDR] = { 0x0c, 8 },
400 [SCxSR] = { 0x10, 16 },
401 [SCxRDR] = { 0x14, 8 },
402 [SCFCR] = { 0x18, 16 },
403 [SCFDR] = { 0x1c, 16 },
404 [SCLSR] = { 0x24, 16 },
407 .overrun_reg = SCLSR,
408 .overrun_mask = SCLSR_ORER,
409 .sampling_rate_mask = SCI_SR(32),
410 .error_mask = SCIF_DEFAULT_ERROR_MASK,
411 .error_clear = SCIF_ERROR_CLEAR,
415 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
418 [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
420 [SCSMR] = { 0x00, 16 },
421 [SCBRR] = { 0x04, 8 },
422 [SCSCR] = { 0x08, 16 },
423 [SCxTDR] = { 0x0c, 8 },
424 [SCxSR] = { 0x10, 16 },
425 [SCxRDR] = { 0x14, 8 },
426 [SCFCR] = { 0x18, 16 },
427 [SCFDR] = { 0x1c, 16 },
428 [SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */
429 [SCRFDR] = { 0x20, 16 },
430 [SCSPTR] = { 0x24, 16 },
431 [SCLSR] = { 0x28, 16 },
434 .overrun_reg = SCLSR,
435 .overrun_mask = SCLSR_ORER,
436 .sampling_rate_mask = SCI_SR(32),
437 .error_mask = SCIF_DEFAULT_ERROR_MASK,
438 .error_clear = SCIF_ERROR_CLEAR,
442 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
445 [SCIx_SH7705_SCIF_REGTYPE] = {
447 [SCSMR] = { 0x00, 16 },
448 [SCBRR] = { 0x04, 8 },
449 [SCSCR] = { 0x08, 16 },
450 [SCxTDR] = { 0x20, 8 },
451 [SCxSR] = { 0x14, 16 },
452 [SCxRDR] = { 0x24, 8 },
453 [SCFCR] = { 0x18, 16 },
454 [SCFDR] = { 0x1c, 16 },
457 .overrun_reg = SCxSR,
458 .overrun_mask = SCIFA_ORER,
459 .sampling_rate_mask = SCI_SR(16),
460 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
461 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
465 #define sci_getreg(up, offset) (&to_sci_port(up)->params->regs[offset])
468 * The "offset" here is rather misleading, in that it refers to an enum
469 * value relative to the port mapping rather than the fixed offset
470 * itself, which needs to be manually retrieved from the platform's
471 * register map for the given port.
473 static unsigned int sci_serial_in(struct uart_port *p, int offset)
475 const struct plat_sci_reg *reg = sci_getreg(p, offset);
478 return ioread8(p->membase + (reg->offset << p->regshift));
479 else if (reg->size == 16)
480 return ioread16(p->membase + (reg->offset << p->regshift));
482 WARN(1, "Invalid register access\n");
487 static void sci_serial_out(struct uart_port *p, int offset, int value)
489 const struct plat_sci_reg *reg = sci_getreg(p, offset);
492 iowrite8(value, p->membase + (reg->offset << p->regshift));
493 else if (reg->size == 16)
494 iowrite16(value, p->membase + (reg->offset << p->regshift));
496 WARN(1, "Invalid register access\n");
499 static void sci_port_enable(struct sci_port *sci_port)
503 if (!sci_port->port.dev)
506 pm_runtime_get_sync(sci_port->port.dev);
508 for (i = 0; i < SCI_NUM_CLKS; i++) {
509 clk_prepare_enable(sci_port->clks[i]);
510 sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
512 sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
515 static void sci_port_disable(struct sci_port *sci_port)
519 if (!sci_port->port.dev)
522 for (i = SCI_NUM_CLKS; i-- > 0; )
523 clk_disable_unprepare(sci_port->clks[i]);
525 pm_runtime_put_sync(sci_port->port.dev);
528 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
531 * Not all ports (such as SCIFA) will support REIE. Rather than
532 * special-casing the port type, we check the port initialization
533 * IRQ enable mask to see whether the IRQ is desired at all. If
534 * it's unset, it's logically inferred that there's no point in
537 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
540 static void sci_start_tx(struct uart_port *port)
542 struct sci_port *s = to_sci_port(port);
545 #ifdef CONFIG_SERIAL_SH_SCI_DMA
546 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
547 u16 new, scr = serial_port_in(port, SCSCR);
549 new = scr | SCSCR_TDRQE;
551 new = scr & ~SCSCR_TDRQE;
553 serial_port_out(port, SCSCR, new);
556 if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
557 dma_submit_error(s->cookie_tx)) {
559 schedule_work(&s->work_tx);
563 if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
564 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
565 ctrl = serial_port_in(port, SCSCR);
566 serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
570 static void sci_stop_tx(struct uart_port *port)
574 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
575 ctrl = serial_port_in(port, SCSCR);
577 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
578 ctrl &= ~SCSCR_TDRQE;
582 serial_port_out(port, SCSCR, ctrl);
585 static void sci_start_rx(struct uart_port *port)
589 ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
591 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
592 ctrl &= ~SCSCR_RDRQE;
594 serial_port_out(port, SCSCR, ctrl);
597 static void sci_stop_rx(struct uart_port *port)
601 ctrl = serial_port_in(port, SCSCR);
603 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
604 ctrl &= ~SCSCR_RDRQE;
606 ctrl &= ~port_rx_irq_mask(port);
608 serial_port_out(port, SCSCR, ctrl);
611 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
613 if (port->type == PORT_SCI) {
614 /* Just store the mask */
615 serial_port_out(port, SCxSR, mask);
616 } else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
617 /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
618 /* Only clear the status bits we want to clear */
619 serial_port_out(port, SCxSR,
620 serial_port_in(port, SCxSR) & mask);
622 /* Store the mask, clear parity/framing errors */
623 serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
627 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
628 defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
630 #ifdef CONFIG_CONSOLE_POLL
631 static int sci_poll_get_char(struct uart_port *port)
633 unsigned short status;
637 status = serial_port_in(port, SCxSR);
638 if (status & SCxSR_ERRORS(port)) {
639 sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
645 if (!(status & SCxSR_RDxF(port)))
648 c = serial_port_in(port, SCxRDR);
651 serial_port_in(port, SCxSR);
652 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
658 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
660 unsigned short status;
663 status = serial_port_in(port, SCxSR);
664 } while (!(status & SCxSR_TDxE(port)));
666 serial_port_out(port, SCxTDR, c);
667 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
669 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
670 CONFIG_SERIAL_SH_SCI_EARLYCON */
672 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
674 struct sci_port *s = to_sci_port(port);
677 * Use port-specific handler if provided.
679 if (s->cfg->ops && s->cfg->ops->init_pins) {
680 s->cfg->ops->init_pins(port, cflag);
684 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
685 u16 data = serial_port_in(port, SCPDR);
686 u16 ctrl = serial_port_in(port, SCPCR);
688 /* Enable RXD and TXD pin functions */
689 ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
690 if (to_sci_port(port)->has_rtscts) {
691 /* RTS# is output, active low, unless autorts */
692 if (!(port->mctrl & TIOCM_RTS)) {
695 } else if (!s->autorts) {
699 /* Enable RTS# pin function */
702 /* Enable CTS# pin function */
705 serial_port_out(port, SCPDR, data);
706 serial_port_out(port, SCPCR, ctrl);
707 } else if (sci_getreg(port, SCSPTR)->size) {
708 u16 status = serial_port_in(port, SCSPTR);
710 /* RTS# is always output; and active low, unless autorts */
711 status |= SCSPTR_RTSIO;
712 if (!(port->mctrl & TIOCM_RTS))
713 status |= SCSPTR_RTSDT;
714 else if (!s->autorts)
715 status &= ~SCSPTR_RTSDT;
716 /* CTS# and SCK are inputs */
717 status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
718 serial_port_out(port, SCSPTR, status);
722 static int sci_txfill(struct uart_port *port)
724 struct sci_port *s = to_sci_port(port);
725 unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
726 const struct plat_sci_reg *reg;
728 reg = sci_getreg(port, SCTFDR);
730 return serial_port_in(port, SCTFDR) & fifo_mask;
732 reg = sci_getreg(port, SCFDR);
734 return serial_port_in(port, SCFDR) >> 8;
736 return !(serial_port_in(port, SCxSR) & SCI_TDRE);
739 static int sci_txroom(struct uart_port *port)
741 return port->fifosize - sci_txfill(port);
744 static int sci_rxfill(struct uart_port *port)
746 struct sci_port *s = to_sci_port(port);
747 unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
748 const struct plat_sci_reg *reg;
750 reg = sci_getreg(port, SCRFDR);
752 return serial_port_in(port, SCRFDR) & fifo_mask;
754 reg = sci_getreg(port, SCFDR);
756 return serial_port_in(port, SCFDR) & fifo_mask;
758 return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
761 /* ********************************************************************** *
762 * the interrupt related routines *
763 * ********************************************************************** */
765 static void sci_transmit_chars(struct uart_port *port)
767 struct circ_buf *xmit = &port->state->xmit;
768 unsigned int stopped = uart_tx_stopped(port);
769 unsigned short status;
773 status = serial_port_in(port, SCxSR);
774 if (!(status & SCxSR_TDxE(port))) {
775 ctrl = serial_port_in(port, SCSCR);
776 if (uart_circ_empty(xmit))
780 serial_port_out(port, SCSCR, ctrl);
784 count = sci_txroom(port);
792 } else if (!uart_circ_empty(xmit) && !stopped) {
793 c = xmit->buf[xmit->tail];
794 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
799 serial_port_out(port, SCxTDR, c);
802 } while (--count > 0);
804 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
806 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
807 uart_write_wakeup(port);
808 if (uart_circ_empty(xmit)) {
811 ctrl = serial_port_in(port, SCSCR);
813 if (port->type != PORT_SCI) {
814 serial_port_in(port, SCxSR); /* Dummy read */
815 sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
819 serial_port_out(port, SCSCR, ctrl);
823 /* On SH3, SCIF may read end-of-break as a space->mark char */
824 #define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); })
826 static void sci_receive_chars(struct uart_port *port)
828 struct tty_port *tport = &port->state->port;
829 int i, count, copied = 0;
830 unsigned short status;
833 status = serial_port_in(port, SCxSR);
834 if (!(status & SCxSR_RDxF(port)))
838 /* Don't copy more bytes than there is room for in the buffer */
839 count = tty_buffer_request_room(tport, sci_rxfill(port));
841 /* If for any reason we can't copy more data, we're done! */
845 if (port->type == PORT_SCI) {
846 char c = serial_port_in(port, SCxRDR);
847 if (uart_handle_sysrq_char(port, c))
850 tty_insert_flip_char(tport, c, TTY_NORMAL);
852 for (i = 0; i < count; i++) {
853 char c = serial_port_in(port, SCxRDR);
855 status = serial_port_in(port, SCxSR);
856 if (uart_handle_sysrq_char(port, c)) {
861 /* Store data and status */
862 if (status & SCxSR_FER(port)) {
864 port->icount.frame++;
865 dev_notice(port->dev, "frame error\n");
866 } else if (status & SCxSR_PER(port)) {
868 port->icount.parity++;
869 dev_notice(port->dev, "parity error\n");
873 tty_insert_flip_char(tport, c, flag);
877 serial_port_in(port, SCxSR); /* dummy read */
878 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
881 port->icount.rx += count;
885 /* Tell the rest of the system the news. New characters! */
886 tty_flip_buffer_push(tport);
888 serial_port_in(port, SCxSR); /* dummy read */
889 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
893 static int sci_handle_errors(struct uart_port *port)
896 unsigned short status = serial_port_in(port, SCxSR);
897 struct tty_port *tport = &port->state->port;
898 struct sci_port *s = to_sci_port(port);
900 /* Handle overruns */
901 if (status & s->params->overrun_mask) {
902 port->icount.overrun++;
905 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
908 dev_notice(port->dev, "overrun error\n");
911 if (status & SCxSR_FER(port)) {
913 port->icount.frame++;
915 if (tty_insert_flip_char(tport, 0, TTY_FRAME))
918 dev_notice(port->dev, "frame error\n");
921 if (status & SCxSR_PER(port)) {
923 port->icount.parity++;
925 if (tty_insert_flip_char(tport, 0, TTY_PARITY))
928 dev_notice(port->dev, "parity error\n");
932 tty_flip_buffer_push(tport);
937 static int sci_handle_fifo_overrun(struct uart_port *port)
939 struct tty_port *tport = &port->state->port;
940 struct sci_port *s = to_sci_port(port);
941 const struct plat_sci_reg *reg;
945 reg = sci_getreg(port, s->params->overrun_reg);
949 status = serial_port_in(port, s->params->overrun_reg);
950 if (status & s->params->overrun_mask) {
951 status &= ~s->params->overrun_mask;
952 serial_port_out(port, s->params->overrun_reg, status);
954 port->icount.overrun++;
956 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
957 tty_flip_buffer_push(tport);
959 dev_dbg(port->dev, "overrun error\n");
966 static int sci_handle_breaks(struct uart_port *port)
969 unsigned short status = serial_port_in(port, SCxSR);
970 struct tty_port *tport = &port->state->port;
972 if (uart_handle_break(port))
975 if (status & SCxSR_BRK(port)) {
978 /* Notify of BREAK */
979 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
982 dev_dbg(port->dev, "BREAK detected\n");
986 tty_flip_buffer_push(tport);
988 copied += sci_handle_fifo_overrun(port);
993 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
999 if (rx_trig >= port->fifosize)
1000 rx_trig = port->fifosize;
1002 /* HSCIF can be set to an arbitrary level. */
1003 if (sci_getreg(port, HSRTRGR)->size) {
1004 serial_port_out(port, HSRTRGR, rx_trig);
1008 switch (port->type) {
1013 } else if (rx_trig < 8) {
1016 } else if (rx_trig < 14) {
1020 bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1029 } else if (rx_trig < 32) {
1032 } else if (rx_trig < 48) {
1036 bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1041 WARN(1, "unknown FIFO configuration");
1045 serial_port_out(port, SCFCR,
1046 (serial_port_in(port, SCFCR) &
1047 ~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1052 static int scif_rtrg_enabled(struct uart_port *port)
1054 if (sci_getreg(port, HSRTRGR)->size)
1055 return serial_port_in(port, HSRTRGR) != 0;
1057 return (serial_port_in(port, SCFCR) &
1058 (SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1061 static void rx_fifo_timer_fn(unsigned long arg)
1063 struct sci_port *s = (struct sci_port *)arg;
1064 struct uart_port *port = &s->port;
1066 dev_dbg(port->dev, "Rx timed out\n");
1067 scif_set_rtrg(port, 1);
1070 static ssize_t rx_trigger_show(struct device *dev,
1071 struct device_attribute *attr,
1074 struct uart_port *port = dev_get_drvdata(dev);
1075 struct sci_port *sci = to_sci_port(port);
1077 return sprintf(buf, "%d\n", sci->rx_trigger);
1080 static ssize_t rx_trigger_store(struct device *dev,
1081 struct device_attribute *attr,
1085 struct uart_port *port = dev_get_drvdata(dev);
1086 struct sci_port *sci = to_sci_port(port);
1090 ret = kstrtol(buf, 0, &r);
1094 sci->rx_trigger = scif_set_rtrg(port, r);
1095 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1096 scif_set_rtrg(port, 1);
1101 static DEVICE_ATTR(rx_fifo_trigger, 0644, rx_trigger_show, rx_trigger_store);
1103 static ssize_t rx_fifo_timeout_show(struct device *dev,
1104 struct device_attribute *attr,
1107 struct uart_port *port = dev_get_drvdata(dev);
1108 struct sci_port *sci = to_sci_port(port);
1111 if (port->type == PORT_HSCIF)
1112 v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1114 v = sci->rx_fifo_timeout;
1116 return sprintf(buf, "%d\n", v);
1119 static ssize_t rx_fifo_timeout_store(struct device *dev,
1120 struct device_attribute *attr,
1124 struct uart_port *port = dev_get_drvdata(dev);
1125 struct sci_port *sci = to_sci_port(port);
1129 ret = kstrtol(buf, 0, &r);
1133 if (port->type == PORT_HSCIF) {
1136 sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1138 sci->rx_fifo_timeout = r;
1139 scif_set_rtrg(port, 1);
1141 setup_timer(&sci->rx_fifo_timer, rx_fifo_timer_fn,
1142 (unsigned long)sci);
1148 static DEVICE_ATTR(rx_fifo_timeout, 0644, rx_fifo_timeout_show, rx_fifo_timeout_store);
1151 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1152 static void sci_dma_tx_complete(void *arg)
1154 struct sci_port *s = arg;
1155 struct uart_port *port = &s->port;
1156 struct circ_buf *xmit = &port->state->xmit;
1157 unsigned long flags;
1159 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1161 spin_lock_irqsave(&port->lock, flags);
1163 xmit->tail += s->tx_dma_len;
1164 xmit->tail &= UART_XMIT_SIZE - 1;
1166 port->icount.tx += s->tx_dma_len;
1168 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1169 uart_write_wakeup(port);
1171 if (!uart_circ_empty(xmit)) {
1173 schedule_work(&s->work_tx);
1175 s->cookie_tx = -EINVAL;
1176 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1177 u16 ctrl = serial_port_in(port, SCSCR);
1178 serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1182 spin_unlock_irqrestore(&port->lock, flags);
1185 /* Locking: called with port lock held */
1186 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1188 struct uart_port *port = &s->port;
1189 struct tty_port *tport = &port->state->port;
1192 copied = tty_insert_flip_string(tport, buf, count);
1194 port->icount.buf_overrun++;
1196 port->icount.rx += copied;
1201 static int sci_dma_rx_find_active(struct sci_port *s)
1205 for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1206 if (s->active_rx == s->cookie_rx[i])
1212 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1214 struct dma_chan *chan = s->chan_rx;
1215 struct uart_port *port = &s->port;
1216 unsigned long flags;
1218 spin_lock_irqsave(&port->lock, flags);
1220 s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1221 spin_unlock_irqrestore(&port->lock, flags);
1222 dmaengine_terminate_all(chan);
1223 dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1224 sg_dma_address(&s->sg_rx[0]));
1225 dma_release_channel(chan);
1227 spin_lock_irqsave(&port->lock, flags);
1229 spin_unlock_irqrestore(&port->lock, flags);
1233 static void sci_dma_rx_complete(void *arg)
1235 struct sci_port *s = arg;
1236 struct dma_chan *chan = s->chan_rx;
1237 struct uart_port *port = &s->port;
1238 struct dma_async_tx_descriptor *desc;
1239 unsigned long flags;
1240 int active, count = 0;
1242 dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1245 spin_lock_irqsave(&port->lock, flags);
1247 active = sci_dma_rx_find_active(s);
1249 count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1251 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1254 tty_flip_buffer_push(&port->state->port);
1256 desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1258 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1262 desc->callback = sci_dma_rx_complete;
1263 desc->callback_param = s;
1264 s->cookie_rx[active] = dmaengine_submit(desc);
1265 if (dma_submit_error(s->cookie_rx[active]))
1268 s->active_rx = s->cookie_rx[!active];
1270 dma_async_issue_pending(chan);
1272 spin_unlock_irqrestore(&port->lock, flags);
1273 dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1274 __func__, s->cookie_rx[active], active, s->active_rx);
1278 spin_unlock_irqrestore(&port->lock, flags);
1279 dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1280 sci_rx_dma_release(s, true);
1283 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1285 struct dma_chan *chan = s->chan_tx;
1286 struct uart_port *port = &s->port;
1287 unsigned long flags;
1289 spin_lock_irqsave(&port->lock, flags);
1291 s->cookie_tx = -EINVAL;
1292 spin_unlock_irqrestore(&port->lock, flags);
1293 dmaengine_terminate_all(chan);
1294 dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1296 dma_release_channel(chan);
1298 spin_lock_irqsave(&port->lock, flags);
1300 spin_unlock_irqrestore(&port->lock, flags);
1304 static void sci_submit_rx(struct sci_port *s)
1306 struct dma_chan *chan = s->chan_rx;
1309 for (i = 0; i < 2; i++) {
1310 struct scatterlist *sg = &s->sg_rx[i];
1311 struct dma_async_tx_descriptor *desc;
1313 desc = dmaengine_prep_slave_sg(chan,
1314 sg, 1, DMA_DEV_TO_MEM,
1315 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1319 desc->callback = sci_dma_rx_complete;
1320 desc->callback_param = s;
1321 s->cookie_rx[i] = dmaengine_submit(desc);
1322 if (dma_submit_error(s->cookie_rx[i]))
1327 s->active_rx = s->cookie_rx[0];
1329 dma_async_issue_pending(chan);
1334 dmaengine_terminate_all(chan);
1335 for (i = 0; i < 2; i++)
1336 s->cookie_rx[i] = -EINVAL;
1337 s->active_rx = -EINVAL;
1338 sci_rx_dma_release(s, true);
1341 static void work_fn_tx(struct work_struct *work)
1343 struct sci_port *s = container_of(work, struct sci_port, work_tx);
1344 struct dma_async_tx_descriptor *desc;
1345 struct dma_chan *chan = s->chan_tx;
1346 struct uart_port *port = &s->port;
1347 struct circ_buf *xmit = &port->state->xmit;
1352 * Port xmit buffer is already mapped, and it is one page... Just adjust
1353 * offsets and lengths. Since it is a circular buffer, we have to
1354 * transmit till the end, and then the rest. Take the port lock to get a
1355 * consistent xmit buffer state.
1357 spin_lock_irq(&port->lock);
1358 buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1359 s->tx_dma_len = min_t(unsigned int,
1360 CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1361 CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1362 spin_unlock_irq(&port->lock);
1364 desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1366 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1368 dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1370 sci_tx_dma_release(s, true);
1374 dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1377 spin_lock_irq(&port->lock);
1378 desc->callback = sci_dma_tx_complete;
1379 desc->callback_param = s;
1380 spin_unlock_irq(&port->lock);
1381 s->cookie_tx = dmaengine_submit(desc);
1382 if (dma_submit_error(s->cookie_tx)) {
1383 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1385 sci_tx_dma_release(s, true);
1389 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1390 __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1392 dma_async_issue_pending(chan);
1395 static void rx_timer_fn(unsigned long arg)
1397 struct sci_port *s = (struct sci_port *)arg;
1398 struct dma_chan *chan = s->chan_rx;
1399 struct uart_port *port = &s->port;
1400 struct dma_tx_state state;
1401 enum dma_status status;
1402 unsigned long flags;
1407 dev_dbg(port->dev, "DMA Rx timed out\n");
1409 spin_lock_irqsave(&port->lock, flags);
1411 active = sci_dma_rx_find_active(s);
1413 spin_unlock_irqrestore(&port->lock, flags);
1417 status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1418 if (status == DMA_COMPLETE) {
1419 spin_unlock_irqrestore(&port->lock, flags);
1420 dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1421 s->active_rx, active);
1423 /* Let packet complete handler take care of the packet */
1427 dmaengine_pause(chan);
1430 * sometimes DMA transfer doesn't stop even if it is stopped and
1431 * data keeps on coming until transaction is complete so check
1432 * for DMA_COMPLETE again
1433 * Let packet complete handler take care of the packet
1435 status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1436 if (status == DMA_COMPLETE) {
1437 spin_unlock_irqrestore(&port->lock, flags);
1438 dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1442 /* Handle incomplete DMA receive */
1443 dmaengine_terminate_all(s->chan_rx);
1444 read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1447 count = sci_dma_rx_push(s, s->rx_buf[active], read);
1449 tty_flip_buffer_push(&port->state->port);
1452 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1455 /* Direct new serial port interrupts back to CPU */
1456 scr = serial_port_in(port, SCSCR);
1457 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1458 scr &= ~SCSCR_RDRQE;
1459 enable_irq(s->irqs[SCIx_RXI_IRQ]);
1461 serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1463 spin_unlock_irqrestore(&port->lock, flags);
1466 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1467 enum dma_transfer_direction dir)
1469 struct dma_chan *chan;
1470 struct dma_slave_config cfg;
1473 chan = dma_request_slave_channel(port->dev,
1474 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1476 dev_warn(port->dev, "dma_request_slave_channel failed\n");
1480 memset(&cfg, 0, sizeof(cfg));
1481 cfg.direction = dir;
1482 if (dir == DMA_MEM_TO_DEV) {
1483 cfg.dst_addr = port->mapbase +
1484 (sci_getreg(port, SCxTDR)->offset << port->regshift);
1485 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1487 cfg.src_addr = port->mapbase +
1488 (sci_getreg(port, SCxRDR)->offset << port->regshift);
1489 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1492 ret = dmaengine_slave_config(chan, &cfg);
1494 dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1495 dma_release_channel(chan);
1502 static void sci_request_dma(struct uart_port *port)
1504 struct sci_port *s = to_sci_port(port);
1505 struct dma_chan *chan;
1507 dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1509 if (!port->dev->of_node)
1512 s->cookie_tx = -EINVAL;
1515 * Don't request a dma channel if no channel was specified
1516 * in the device tree.
1518 if (!of_find_property(port->dev->of_node, "dmas", NULL))
1521 chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1522 dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1525 /* UART circular tx buffer is an aligned page. */
1526 s->tx_dma_addr = dma_map_single(chan->device->dev,
1527 port->state->xmit.buf,
1530 if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1531 dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1532 dma_release_channel(chan);
1535 dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1536 __func__, UART_XMIT_SIZE,
1537 port->state->xmit.buf, &s->tx_dma_addr);
1540 INIT_WORK(&s->work_tx, work_fn_tx);
1543 chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1544 dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1552 s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1553 buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1557 "Failed to allocate Rx dma buffer, using PIO\n");
1558 dma_release_channel(chan);
1563 for (i = 0; i < 2; i++) {
1564 struct scatterlist *sg = &s->sg_rx[i];
1566 sg_init_table(sg, 1);
1568 sg_dma_address(sg) = dma;
1569 sg_dma_len(sg) = s->buf_len_rx;
1571 buf += s->buf_len_rx;
1572 dma += s->buf_len_rx;
1575 setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1577 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1582 static void sci_free_dma(struct uart_port *port)
1584 struct sci_port *s = to_sci_port(port);
1587 sci_tx_dma_release(s, false);
1589 sci_rx_dma_release(s, false);
1592 static void sci_flush_buffer(struct uart_port *port)
1595 * In uart_flush_buffer(), the xmit circular buffer has just been
1596 * cleared, so we have to reset tx_dma_len accordingly.
1598 to_sci_port(port)->tx_dma_len = 0;
1600 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1601 static inline void sci_request_dma(struct uart_port *port)
1605 static inline void sci_free_dma(struct uart_port *port)
1609 #define sci_flush_buffer NULL
1610 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1612 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1614 struct uart_port *port = ptr;
1615 struct sci_port *s = to_sci_port(port);
1617 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1619 u16 scr = serial_port_in(port, SCSCR);
1620 u16 ssr = serial_port_in(port, SCxSR);
1622 /* Disable future Rx interrupts */
1623 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1624 disable_irq_nosync(irq);
1630 serial_port_out(port, SCSCR, scr);
1631 /* Clear current interrupt */
1632 serial_port_out(port, SCxSR,
1633 ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1634 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
1635 jiffies, s->rx_timeout);
1636 mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1642 if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1643 if (!scif_rtrg_enabled(port))
1644 scif_set_rtrg(port, s->rx_trigger);
1646 mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1647 s->rx_frame * s->rx_fifo_timeout, 1000));
1650 /* I think sci_receive_chars has to be called irrespective
1651 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1654 sci_receive_chars(ptr);
1659 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1661 struct uart_port *port = ptr;
1662 unsigned long flags;
1664 spin_lock_irqsave(&port->lock, flags);
1665 sci_transmit_chars(port);
1666 spin_unlock_irqrestore(&port->lock, flags);
1671 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1673 struct uart_port *port = ptr;
1674 struct sci_port *s = to_sci_port(port);
1677 if (port->type == PORT_SCI) {
1678 if (sci_handle_errors(port)) {
1679 /* discard character in rx buffer */
1680 serial_port_in(port, SCxSR);
1681 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1684 sci_handle_fifo_overrun(port);
1686 sci_receive_chars(ptr);
1689 sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1691 /* Kick the transmission */
1693 sci_tx_interrupt(irq, ptr);
1698 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1700 struct uart_port *port = ptr;
1703 sci_handle_breaks(port);
1704 sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1709 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1711 unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1712 struct uart_port *port = ptr;
1713 struct sci_port *s = to_sci_port(port);
1714 irqreturn_t ret = IRQ_NONE;
1716 ssr_status = serial_port_in(port, SCxSR);
1717 scr_status = serial_port_in(port, SCSCR);
1718 if (s->params->overrun_reg == SCxSR)
1719 orer_status = ssr_status;
1720 else if (sci_getreg(port, s->params->overrun_reg)->size)
1721 orer_status = serial_port_in(port, s->params->overrun_reg);
1723 err_enabled = scr_status & port_rx_irq_mask(port);
1726 if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1728 ret = sci_tx_interrupt(irq, ptr);
1731 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1734 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1735 (scr_status & SCSCR_RIE))
1736 ret = sci_rx_interrupt(irq, ptr);
1738 /* Error Interrupt */
1739 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1740 ret = sci_er_interrupt(irq, ptr);
1742 /* Break Interrupt */
1743 if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1744 ret = sci_br_interrupt(irq, ptr);
1746 /* Overrun Interrupt */
1747 if (orer_status & s->params->overrun_mask) {
1748 sci_handle_fifo_overrun(port);
1755 static const struct sci_irq_desc {
1757 irq_handler_t handler;
1758 } sci_irq_desc[] = {
1760 * Split out handlers, the default case.
1764 .handler = sci_er_interrupt,
1769 .handler = sci_rx_interrupt,
1774 .handler = sci_tx_interrupt,
1779 .handler = sci_br_interrupt,
1783 * Special muxed handler.
1787 .handler = sci_mpxed_interrupt,
1791 static int sci_request_irq(struct sci_port *port)
1793 struct uart_port *up = &port->port;
1796 for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1797 const struct sci_irq_desc *desc;
1800 if (SCIx_IRQ_IS_MUXED(port)) {
1804 irq = port->irqs[i];
1807 * Certain port types won't support all of the
1808 * available interrupt sources.
1810 if (unlikely(irq < 0))
1814 desc = sci_irq_desc + i;
1815 port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1816 dev_name(up->dev), desc->desc);
1817 if (!port->irqstr[j]) {
1822 ret = request_irq(irq, desc->handler, up->irqflags,
1823 port->irqstr[j], port);
1824 if (unlikely(ret)) {
1825 dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1834 free_irq(port->irqs[i], port);
1838 kfree(port->irqstr[j]);
1843 static void sci_free_irq(struct sci_port *port)
1848 * Intentionally in reverse order so we iterate over the muxed
1851 for (i = 0; i < SCIx_NR_IRQS; i++) {
1852 int irq = port->irqs[i];
1855 * Certain port types won't support all of the available
1856 * interrupt sources.
1858 if (unlikely(irq < 0))
1861 free_irq(port->irqs[i], port);
1862 kfree(port->irqstr[i]);
1864 if (SCIx_IRQ_IS_MUXED(port)) {
1865 /* If there's only one IRQ, we're done. */
1871 static unsigned int sci_tx_empty(struct uart_port *port)
1873 unsigned short status = serial_port_in(port, SCxSR);
1874 unsigned short in_tx_fifo = sci_txfill(port);
1876 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1879 static void sci_set_rts(struct uart_port *port, bool state)
1881 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1882 u16 data = serial_port_in(port, SCPDR);
1886 data &= ~SCPDR_RTSD;
1889 serial_port_out(port, SCPDR, data);
1891 /* RTS# is output */
1892 serial_port_out(port, SCPCR,
1893 serial_port_in(port, SCPCR) | SCPCR_RTSC);
1894 } else if (sci_getreg(port, SCSPTR)->size) {
1895 u16 ctrl = serial_port_in(port, SCSPTR);
1899 ctrl &= ~SCSPTR_RTSDT;
1901 ctrl |= SCSPTR_RTSDT;
1902 serial_port_out(port, SCSPTR, ctrl);
1906 static bool sci_get_cts(struct uart_port *port)
1908 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1910 return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
1911 } else if (sci_getreg(port, SCSPTR)->size) {
1913 return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
1920 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1921 * CTS/RTS is supported in hardware by at least one port and controlled
1922 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1923 * handled via the ->init_pins() op, which is a bit of a one-way street,
1924 * lacking any ability to defer pin control -- this will later be
1925 * converted over to the GPIO framework).
1927 * Other modes (such as loopback) are supported generically on certain
1928 * port types, but not others. For these it's sufficient to test for the
1929 * existence of the support register and simply ignore the port type.
1931 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1933 struct sci_port *s = to_sci_port(port);
1935 if (mctrl & TIOCM_LOOP) {
1936 const struct plat_sci_reg *reg;
1939 * Standard loopback mode for SCFCR ports.
1941 reg = sci_getreg(port, SCFCR);
1943 serial_port_out(port, SCFCR,
1944 serial_port_in(port, SCFCR) |
1948 mctrl_gpio_set(s->gpios, mctrl);
1953 if (!(mctrl & TIOCM_RTS)) {
1954 /* Disable Auto RTS */
1955 serial_port_out(port, SCFCR,
1956 serial_port_in(port, SCFCR) & ~SCFCR_MCE);
1959 sci_set_rts(port, 0);
1960 } else if (s->autorts) {
1961 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1962 /* Enable RTS# pin function */
1963 serial_port_out(port, SCPCR,
1964 serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
1967 /* Enable Auto RTS */
1968 serial_port_out(port, SCFCR,
1969 serial_port_in(port, SCFCR) | SCFCR_MCE);
1972 sci_set_rts(port, 1);
1976 static unsigned int sci_get_mctrl(struct uart_port *port)
1978 struct sci_port *s = to_sci_port(port);
1979 struct mctrl_gpios *gpios = s->gpios;
1980 unsigned int mctrl = 0;
1982 mctrl_gpio_get(gpios, &mctrl);
1985 * CTS/RTS is handled in hardware when supported, while nothing
1989 if (sci_get_cts(port))
1991 } else if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS))) {
1994 if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))
1996 if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))
2002 static void sci_enable_ms(struct uart_port *port)
2004 mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2007 static void sci_break_ctl(struct uart_port *port, int break_state)
2009 unsigned short scscr, scsptr;
2010 unsigned long flags;
2012 /* check wheter the port has SCSPTR */
2013 if (!sci_getreg(port, SCSPTR)->size) {
2015 * Not supported by hardware. Most parts couple break and rx
2016 * interrupts together, with break detection always enabled.
2021 spin_lock_irqsave(&port->lock, flags);
2022 scsptr = serial_port_in(port, SCSPTR);
2023 scscr = serial_port_in(port, SCSCR);
2025 if (break_state == -1) {
2026 scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2029 scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2033 serial_port_out(port, SCSPTR, scsptr);
2034 serial_port_out(port, SCSCR, scscr);
2035 spin_unlock_irqrestore(&port->lock, flags);
2038 static int sci_startup(struct uart_port *port)
2040 struct sci_port *s = to_sci_port(port);
2043 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2045 sci_request_dma(port);
2047 ret = sci_request_irq(s);
2048 if (unlikely(ret < 0)) {
2056 static void sci_shutdown(struct uart_port *port)
2058 struct sci_port *s = to_sci_port(port);
2059 unsigned long flags;
2062 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2065 mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2067 spin_lock_irqsave(&port->lock, flags);
2071 * Stop RX and TX, disable related interrupts, keep clock source
2072 * and HSCIF TOT bits
2074 scr = serial_port_in(port, SCSCR);
2075 serial_port_out(port, SCSCR, scr &
2076 (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2077 spin_unlock_irqrestore(&port->lock, flags);
2079 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2081 dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2083 del_timer_sync(&s->rx_timer);
2091 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2094 unsigned long freq = s->clk_rates[SCI_SCK];
2095 int err, min_err = INT_MAX;
2098 if (s->port.type != PORT_HSCIF)
2101 for_each_sr(sr, s) {
2102 err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2103 if (abs(err) >= abs(min_err))
2113 dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2118 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2119 unsigned long freq, unsigned int *dlr,
2122 int err, min_err = INT_MAX;
2123 unsigned int sr, dl;
2125 if (s->port.type != PORT_HSCIF)
2128 for_each_sr(sr, s) {
2129 dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2130 dl = clamp(dl, 1U, 65535U);
2132 err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2133 if (abs(err) >= abs(min_err))
2144 dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2145 min_err, *dlr, *srr + 1);
2149 /* calculate sample rate, BRR, and clock select */
2150 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2151 unsigned int *brr, unsigned int *srr,
2154 unsigned long freq = s->clk_rates[SCI_FCK];
2155 unsigned int sr, br, prediv, scrate, c;
2156 int err, min_err = INT_MAX;
2158 if (s->port.type != PORT_HSCIF)
2162 * Find the combination of sample rate and clock select with the
2163 * smallest deviation from the desired baud rate.
2164 * Prefer high sample rates to maximise the receive margin.
2166 * M: Receive margin (%)
2167 * N: Ratio of bit rate to clock (N = sampling rate)
2168 * D: Clock duty (D = 0 to 1.0)
2169 * L: Frame length (L = 9 to 12)
2170 * F: Absolute value of clock frequency deviation
2172 * M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2173 * (|D - 0.5| / N * (1 + F))|
2174 * NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2176 for_each_sr(sr, s) {
2177 for (c = 0; c <= 3; c++) {
2178 /* integerized formulas from HSCIF documentation */
2179 prediv = sr * (1 << (2 * c + 1));
2182 * We need to calculate:
2184 * br = freq / (prediv * bps) clamped to [1..256]
2185 * err = freq / (br * prediv) - bps
2187 * Watch out for overflow when calculating the desired
2188 * sampling clock rate!
2190 if (bps > UINT_MAX / prediv)
2193 scrate = prediv * bps;
2194 br = DIV_ROUND_CLOSEST(freq, scrate);
2195 br = clamp(br, 1U, 256U);
2197 err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2198 if (abs(err) >= abs(min_err))
2212 dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2213 min_err, *brr, *srr + 1, *cks);
2217 static void sci_reset(struct uart_port *port)
2219 const struct plat_sci_reg *reg;
2220 unsigned int status;
2221 struct sci_port *s = to_sci_port(port);
2223 serial_port_out(port, SCSCR, s->hscif_tot); /* TE=0, RE=0, CKE1=0 */
2225 reg = sci_getreg(port, SCFCR);
2227 serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2229 sci_clear_SCxSR(port,
2230 SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2231 SCxSR_BREAK_CLEAR(port));
2232 if (sci_getreg(port, SCLSR)->size) {
2233 status = serial_port_in(port, SCLSR);
2234 status &= ~(SCLSR_TO | SCLSR_ORER);
2235 serial_port_out(port, SCLSR, status);
2238 if (s->rx_trigger > 1) {
2239 if (s->rx_fifo_timeout) {
2240 scif_set_rtrg(port, 1);
2241 setup_timer(&s->rx_fifo_timer, rx_fifo_timer_fn,
2244 if (port->type == PORT_SCIFA ||
2245 port->type == PORT_SCIFB)
2246 scif_set_rtrg(port, 1);
2248 scif_set_rtrg(port, s->rx_trigger);
2253 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2254 struct ktermios *old)
2256 unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2257 unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2258 unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2259 struct sci_port *s = to_sci_port(port);
2260 const struct plat_sci_reg *reg;
2261 int min_err = INT_MAX, err;
2262 unsigned long max_freq = 0;
2264 unsigned long flags;
2266 if ((termios->c_cflag & CSIZE) == CS7)
2267 smr_val |= SCSMR_CHR;
2268 if (termios->c_cflag & PARENB)
2269 smr_val |= SCSMR_PE;
2270 if (termios->c_cflag & PARODD)
2271 smr_val |= SCSMR_PE | SCSMR_ODD;
2272 if (termios->c_cflag & CSTOPB)
2273 smr_val |= SCSMR_STOP;
2276 * earlyprintk comes here early on with port->uartclk set to zero.
2277 * the clock framework is not up and running at this point so here
2278 * we assume that 115200 is the maximum baud rate. please note that
2279 * the baud rate is not programmed during earlyprintk - it is assumed
2280 * that the previous boot loader has enabled required clocks and
2281 * setup the baud rate generator hardware for us already.
2283 if (!port->uartclk) {
2284 baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2288 for (i = 0; i < SCI_NUM_CLKS; i++)
2289 max_freq = max(max_freq, s->clk_rates[i]);
2291 baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2296 * There can be multiple sources for the sampling clock. Find the one
2297 * that gives us the smallest deviation from the desired baud rate.
2300 /* Optional Undivided External Clock */
2301 if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2302 port->type != PORT_SCIFB) {
2303 err = sci_sck_calc(s, baud, &srr1);
2304 if (abs(err) < abs(min_err)) {
2306 scr_val = SCSCR_CKE1;
2315 /* Optional BRG Frequency Divided External Clock */
2316 if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2317 err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2319 if (abs(err) < abs(min_err)) {
2320 best_clk = SCI_SCIF_CLK;
2321 scr_val = SCSCR_CKE1;
2331 /* Optional BRG Frequency Divided Internal Clock */
2332 if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2333 err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2335 if (abs(err) < abs(min_err)) {
2336 best_clk = SCI_BRG_INT;
2337 scr_val = SCSCR_CKE1;
2347 /* Divided Functional Clock using standard Bit Rate Register */
2348 err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2349 if (abs(err) < abs(min_err)) {
2360 dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2361 s->clks[best_clk], baud, min_err);
2366 * Program the optional External Baud Rate Generator (BRG) first.
2367 * It controls the mux to select (H)SCK or frequency divided clock.
2369 if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2370 serial_port_out(port, SCDL, dl);
2371 serial_port_out(port, SCCKS, sccks);
2374 spin_lock_irqsave(&port->lock, flags);
2378 uart_update_timeout(port, termios->c_cflag, baud);
2380 if (best_clk >= 0) {
2381 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2383 case 5: smr_val |= SCSMR_SRC_5; break;
2384 case 7: smr_val |= SCSMR_SRC_7; break;
2385 case 11: smr_val |= SCSMR_SRC_11; break;
2386 case 13: smr_val |= SCSMR_SRC_13; break;
2387 case 16: smr_val |= SCSMR_SRC_16; break;
2388 case 17: smr_val |= SCSMR_SRC_17; break;
2389 case 19: smr_val |= SCSMR_SRC_19; break;
2390 case 27: smr_val |= SCSMR_SRC_27; break;
2393 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2394 serial_port_out(port, SCSMR, smr_val);
2395 serial_port_out(port, SCBRR, brr);
2396 if (sci_getreg(port, HSSRR)->size)
2397 serial_port_out(port, HSSRR, srr | HSCIF_SRE);
2399 /* Wait one bit interval */
2400 udelay((1000000 + (baud - 1)) / baud);
2402 /* Don't touch the bit rate configuration */
2403 scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2404 smr_val |= serial_port_in(port, SCSMR) &
2405 (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2406 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2407 serial_port_out(port, SCSMR, smr_val);
2410 sci_init_pins(port, termios->c_cflag);
2412 port->status &= ~UPSTAT_AUTOCTS;
2414 reg = sci_getreg(port, SCFCR);
2416 unsigned short ctrl = serial_port_in(port, SCFCR);
2418 if ((port->flags & UPF_HARD_FLOW) &&
2419 (termios->c_cflag & CRTSCTS)) {
2420 /* There is no CTS interrupt to restart the hardware */
2421 port->status |= UPSTAT_AUTOCTS;
2422 /* MCE is enabled when RTS is raised */
2427 * As we've done a sci_reset() above, ensure we don't
2428 * interfere with the FIFOs while toggling MCE. As the
2429 * reset values could still be set, simply mask them out.
2431 ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2433 serial_port_out(port, SCFCR, ctrl);
2435 if (port->flags & UPF_HARD_FLOW) {
2436 /* Refresh (Auto) RTS */
2437 sci_set_mctrl(port, port->mctrl);
2440 scr_val |= SCSCR_RE | SCSCR_TE |
2441 (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2442 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2443 if ((srr + 1 == 5) &&
2444 (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2446 * In asynchronous mode, when the sampling rate is 1/5, first
2447 * received data may become invalid on some SCIFA and SCIFB.
2448 * To avoid this problem wait more than 1 serial data time (1
2449 * bit time x serial data number) after setting SCSCR.RE = 1.
2451 udelay(DIV_ROUND_UP(10 * 1000000, baud));
2455 * Calculate delay for 2 DMA buffers (4 FIFO).
2456 * See serial_core.c::uart_update_timeout().
2457 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2458 * function calculates 1 jiffie for the data plus 5 jiffies for the
2459 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2460 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2461 * value obtained by this formula is too small. Therefore, if the value
2462 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2464 /* byte size and parity */
2465 switch (termios->c_cflag & CSIZE) {
2480 if (termios->c_cflag & CSTOPB)
2482 if (termios->c_cflag & PARENB)
2485 s->rx_frame = (100 * bits * HZ) / (baud / 10);
2486 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2487 s->rx_timeout = DIV_ROUND_UP(s->buf_len_rx * 2 * s->rx_frame, 1000);
2488 if (s->rx_timeout < msecs_to_jiffies(20))
2489 s->rx_timeout = msecs_to_jiffies(20);
2492 if ((termios->c_cflag & CREAD) != 0)
2495 spin_unlock_irqrestore(&port->lock, flags);
2497 sci_port_disable(s);
2499 if (UART_ENABLE_MS(port, termios->c_cflag))
2500 sci_enable_ms(port);
2503 static void sci_pm(struct uart_port *port, unsigned int state,
2504 unsigned int oldstate)
2506 struct sci_port *sci_port = to_sci_port(port);
2509 case UART_PM_STATE_OFF:
2510 sci_port_disable(sci_port);
2513 sci_port_enable(sci_port);
2518 static const char *sci_type(struct uart_port *port)
2520 switch (port->type) {
2538 static int sci_remap_port(struct uart_port *port)
2540 struct sci_port *sport = to_sci_port(port);
2543 * Nothing to do if there's already an established membase.
2548 if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2549 port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2550 if (unlikely(!port->membase)) {
2551 dev_err(port->dev, "can't remap port#%d\n", port->line);
2556 * For the simple (and majority of) cases where we don't
2557 * need to do any remapping, just cast the cookie
2560 port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2566 static void sci_release_port(struct uart_port *port)
2568 struct sci_port *sport = to_sci_port(port);
2570 if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2571 iounmap(port->membase);
2572 port->membase = NULL;
2575 release_mem_region(port->mapbase, sport->reg_size);
2578 static int sci_request_port(struct uart_port *port)
2580 struct resource *res;
2581 struct sci_port *sport = to_sci_port(port);
2584 res = request_mem_region(port->mapbase, sport->reg_size,
2585 dev_name(port->dev));
2586 if (unlikely(res == NULL)) {
2587 dev_err(port->dev, "request_mem_region failed.");
2591 ret = sci_remap_port(port);
2592 if (unlikely(ret != 0)) {
2593 release_resource(res);
2600 static void sci_config_port(struct uart_port *port, int flags)
2602 if (flags & UART_CONFIG_TYPE) {
2603 struct sci_port *sport = to_sci_port(port);
2605 port->type = sport->cfg->type;
2606 sci_request_port(port);
2610 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2612 if (ser->baud_base < 2400)
2613 /* No paper tape reader for Mitch.. */
2619 static const struct uart_ops sci_uart_ops = {
2620 .tx_empty = sci_tx_empty,
2621 .set_mctrl = sci_set_mctrl,
2622 .get_mctrl = sci_get_mctrl,
2623 .start_tx = sci_start_tx,
2624 .stop_tx = sci_stop_tx,
2625 .stop_rx = sci_stop_rx,
2626 .enable_ms = sci_enable_ms,
2627 .break_ctl = sci_break_ctl,
2628 .startup = sci_startup,
2629 .shutdown = sci_shutdown,
2630 .flush_buffer = sci_flush_buffer,
2631 .set_termios = sci_set_termios,
2634 .release_port = sci_release_port,
2635 .request_port = sci_request_port,
2636 .config_port = sci_config_port,
2637 .verify_port = sci_verify_port,
2638 #ifdef CONFIG_CONSOLE_POLL
2639 .poll_get_char = sci_poll_get_char,
2640 .poll_put_char = sci_poll_put_char,
2644 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2646 const char *clk_names[] = {
2649 [SCI_BRG_INT] = "brg_int",
2650 [SCI_SCIF_CLK] = "scif_clk",
2655 if (sci_port->cfg->type == PORT_HSCIF)
2656 clk_names[SCI_SCK] = "hsck";
2658 for (i = 0; i < SCI_NUM_CLKS; i++) {
2659 clk = devm_clk_get(dev, clk_names[i]);
2660 if (PTR_ERR(clk) == -EPROBE_DEFER)
2661 return -EPROBE_DEFER;
2663 if (IS_ERR(clk) && i == SCI_FCK) {
2665 * "fck" used to be called "sci_ick", and we need to
2666 * maintain DT backward compatibility.
2668 clk = devm_clk_get(dev, "sci_ick");
2669 if (PTR_ERR(clk) == -EPROBE_DEFER)
2670 return -EPROBE_DEFER;
2676 * Not all SH platforms declare a clock lookup entry
2677 * for SCI devices, in which case we need to get the
2678 * global "peripheral_clk" clock.
2680 clk = devm_clk_get(dev, "peripheral_clk");
2684 dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2686 return PTR_ERR(clk);
2691 dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2694 dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
2696 sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2701 static const struct sci_port_params *
2702 sci_probe_regmap(const struct plat_sci_port *cfg)
2704 unsigned int regtype;
2706 if (cfg->regtype != SCIx_PROBE_REGTYPE)
2707 return &sci_port_params[cfg->regtype];
2709 switch (cfg->type) {
2711 regtype = SCIx_SCI_REGTYPE;
2714 regtype = SCIx_IRDA_REGTYPE;
2717 regtype = SCIx_SCIFA_REGTYPE;
2720 regtype = SCIx_SCIFB_REGTYPE;
2724 * The SH-4 is a bit of a misnomer here, although that's
2725 * where this particular port layout originated. This
2726 * configuration (or some slight variation thereof)
2727 * remains the dominant model for all SCIFs.
2729 regtype = SCIx_SH4_SCIF_REGTYPE;
2732 regtype = SCIx_HSCIF_REGTYPE;
2735 pr_err("Can't probe register map for given port\n");
2739 return &sci_port_params[regtype];
2742 static int sci_init_single(struct platform_device *dev,
2743 struct sci_port *sci_port, unsigned int index,
2744 const struct plat_sci_port *p, bool early)
2746 struct uart_port *port = &sci_port->port;
2747 const struct resource *res;
2753 port->ops = &sci_uart_ops;
2754 port->iotype = UPIO_MEM;
2757 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2761 port->mapbase = res->start;
2762 sci_port->reg_size = resource_size(res);
2764 for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2765 sci_port->irqs[i] = platform_get_irq(dev, i);
2767 /* The SCI generates several interrupts. They can be muxed together or
2768 * connected to different interrupt lines. In the muxed case only one
2769 * interrupt resource is specified. In the non-muxed case three or four
2770 * interrupt resources are specified, as the BRI interrupt is optional.
2772 if (sci_port->irqs[0] < 0)
2775 if (sci_port->irqs[1] < 0) {
2776 sci_port->irqs[1] = sci_port->irqs[0];
2777 sci_port->irqs[2] = sci_port->irqs[0];
2778 sci_port->irqs[3] = sci_port->irqs[0];
2781 sci_port->params = sci_probe_regmap(p);
2782 if (unlikely(sci_port->params == NULL))
2787 sci_port->rx_trigger = 48;
2790 sci_port->rx_trigger = 64;
2793 sci_port->rx_trigger = 32;
2796 if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2797 /* RX triggering not implemented for this IP */
2798 sci_port->rx_trigger = 1;
2800 sci_port->rx_trigger = 8;
2803 sci_port->rx_trigger = 1;
2807 sci_port->rx_fifo_timeout = 0;
2808 sci_port->hscif_tot = 0;
2810 /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2811 * match the SoC datasheet, this should be investigated. Let platform
2812 * data override the sampling rate for now.
2814 sci_port->sampling_rate_mask = p->sampling_rate
2815 ? SCI_SR(p->sampling_rate)
2816 : sci_port->params->sampling_rate_mask;
2819 ret = sci_init_clocks(sci_port, &dev->dev);
2823 port->dev = &dev->dev;
2825 pm_runtime_enable(&dev->dev);
2828 port->type = p->type;
2829 port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2830 port->fifosize = sci_port->params->fifosize;
2832 if (port->type == PORT_SCI) {
2833 if (sci_port->reg_size >= 0x20)
2840 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2841 * for the multi-IRQ ports, which is where we are primarily
2842 * concerned with the shutdown path synchronization.
2844 * For the muxed case there's nothing more to do.
2846 port->irq = sci_port->irqs[SCIx_RXI_IRQ];
2849 port->serial_in = sci_serial_in;
2850 port->serial_out = sci_serial_out;
2855 static void sci_cleanup_single(struct sci_port *port)
2857 pm_runtime_disable(port->port.dev);
2860 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2861 defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2862 static void serial_console_putchar(struct uart_port *port, int ch)
2864 sci_poll_put_char(port, ch);
2868 * Print a string to the serial port trying not to disturb
2869 * any possible real use of the port...
2871 static void serial_console_write(struct console *co, const char *s,
2874 struct sci_port *sci_port = &sci_ports[co->index];
2875 struct uart_port *port = &sci_port->port;
2876 unsigned short bits, ctrl, ctrl_temp;
2877 unsigned long flags;
2880 local_irq_save(flags);
2881 #if defined(SUPPORT_SYSRQ)
2886 if (oops_in_progress)
2887 locked = spin_trylock(&port->lock);
2889 spin_lock(&port->lock);
2891 /* first save SCSCR then disable interrupts, keep clock source */
2892 ctrl = serial_port_in(port, SCSCR);
2893 ctrl_temp = SCSCR_RE | SCSCR_TE |
2894 (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2895 (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2896 serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
2898 uart_console_write(port, s, count, serial_console_putchar);
2900 /* wait until fifo is empty and last bit has been transmitted */
2901 bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2902 while ((serial_port_in(port, SCxSR) & bits) != bits)
2905 /* restore the SCSCR */
2906 serial_port_out(port, SCSCR, ctrl);
2909 spin_unlock(&port->lock);
2910 local_irq_restore(flags);
2913 static int serial_console_setup(struct console *co, char *options)
2915 struct sci_port *sci_port;
2916 struct uart_port *port;
2924 * Refuse to handle any bogus ports.
2926 if (co->index < 0 || co->index >= SCI_NPORTS)
2929 sci_port = &sci_ports[co->index];
2930 port = &sci_port->port;
2933 * Refuse to handle uninitialized ports.
2938 ret = sci_remap_port(port);
2939 if (unlikely(ret != 0))
2943 uart_parse_options(options, &baud, &parity, &bits, &flow);
2945 return uart_set_options(port, co, baud, parity, bits, flow);
2948 static struct console serial_console = {
2950 .device = uart_console_device,
2951 .write = serial_console_write,
2952 .setup = serial_console_setup,
2953 .flags = CON_PRINTBUFFER,
2955 .data = &sci_uart_driver,
2958 static struct console early_serial_console = {
2959 .name = "early_ttySC",
2960 .write = serial_console_write,
2961 .flags = CON_PRINTBUFFER,
2965 static char early_serial_buf[32];
2967 static int sci_probe_earlyprintk(struct platform_device *pdev)
2969 const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
2971 if (early_serial_console.data)
2974 early_serial_console.index = pdev->id;
2976 sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
2978 serial_console_setup(&early_serial_console, early_serial_buf);
2980 if (!strstr(early_serial_buf, "keep"))
2981 early_serial_console.flags |= CON_BOOT;
2983 register_console(&early_serial_console);
2987 #define SCI_CONSOLE (&serial_console)
2990 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
2995 #define SCI_CONSOLE NULL
2997 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
2999 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3001 static DEFINE_MUTEX(sci_uart_registration_lock);
3002 static struct uart_driver sci_uart_driver = {
3003 .owner = THIS_MODULE,
3004 .driver_name = "sci",
3005 .dev_name = "ttySC",
3007 .minor = SCI_MINOR_START,
3009 .cons = SCI_CONSOLE,
3012 static int sci_remove(struct platform_device *dev)
3014 struct sci_port *port = platform_get_drvdata(dev);
3016 uart_remove_one_port(&sci_uart_driver, &port->port);
3018 sci_cleanup_single(port);
3020 if (port->port.fifosize > 1) {
3021 sysfs_remove_file(&dev->dev.kobj,
3022 &dev_attr_rx_fifo_trigger.attr);
3024 if (port->port.type == PORT_SCIFA || port->port.type == PORT_SCIFB ||
3025 port->port.type == PORT_HSCIF) {
3026 sysfs_remove_file(&dev->dev.kobj,
3027 &dev_attr_rx_fifo_timeout.attr);
3034 #define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
3035 #define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
3036 #define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
3038 static const struct of_device_id of_sci_match[] = {
3039 /* SoC-specific types */
3041 .compatible = "renesas,scif-r7s72100",
3042 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3044 /* Family-specific types */
3046 .compatible = "renesas,rcar-gen1-scif",
3047 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3049 .compatible = "renesas,rcar-gen2-scif",
3050 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3052 .compatible = "renesas,rcar-gen3-scif",
3053 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3057 .compatible = "renesas,scif",
3058 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3060 .compatible = "renesas,scifa",
3061 .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3063 .compatible = "renesas,scifb",
3064 .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3066 .compatible = "renesas,hscif",
3067 .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3069 .compatible = "renesas,sci",
3070 .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3075 MODULE_DEVICE_TABLE(of, of_sci_match);
3077 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3078 unsigned int *dev_id)
3080 struct device_node *np = pdev->dev.of_node;
3081 struct plat_sci_port *p;
3082 struct sci_port *sp;
3086 if (!IS_ENABLED(CONFIG_OF) || !np)
3089 data = of_device_get_match_data(&pdev->dev);
3091 p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3095 /* Get the line number from the aliases node. */
3096 id = of_alias_get_id(np, "serial");
3098 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3102 sp = &sci_ports[id];
3105 p->type = SCI_OF_TYPE(data);
3106 p->regtype = SCI_OF_REGTYPE(data);
3108 sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3113 static int sci_probe_single(struct platform_device *dev,
3115 struct plat_sci_port *p,
3116 struct sci_port *sciport)
3121 if (unlikely(index >= SCI_NPORTS)) {
3122 dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3123 index+1, SCI_NPORTS);
3124 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3128 mutex_lock(&sci_uart_registration_lock);
3129 if (!sci_uart_driver.state) {
3130 ret = uart_register_driver(&sci_uart_driver);
3132 mutex_unlock(&sci_uart_registration_lock);
3136 mutex_unlock(&sci_uart_registration_lock);
3138 ret = sci_init_single(dev, sciport, index, p, false);
3142 sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3143 if (IS_ERR(sciport->gpios) && PTR_ERR(sciport->gpios) != -ENOSYS)
3144 return PTR_ERR(sciport->gpios);
3146 if (sciport->has_rtscts) {
3147 if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3149 !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3151 dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3154 sciport->port.flags |= UPF_HARD_FLOW;
3157 ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3159 sci_cleanup_single(sciport);
3166 static int sci_probe(struct platform_device *dev)
3168 struct plat_sci_port *p;
3169 struct sci_port *sp;
3170 unsigned int dev_id;
3174 * If we've come here via earlyprintk initialization, head off to
3175 * the special early probe. We don't have sufficient device state
3176 * to make it beyond this yet.
3178 if (is_early_platform_device(dev))
3179 return sci_probe_earlyprintk(dev);
3181 if (dev->dev.of_node) {
3182 p = sci_parse_dt(dev, &dev_id);
3186 p = dev->dev.platform_data;
3188 dev_err(&dev->dev, "no platform data supplied\n");
3195 sp = &sci_ports[dev_id];
3196 platform_set_drvdata(dev, sp);
3198 ret = sci_probe_single(dev, dev_id, p, sp);
3202 if (sp->port.fifosize > 1) {
3203 ret = sysfs_create_file(&dev->dev.kobj,
3204 &dev_attr_rx_fifo_trigger.attr);
3208 if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3209 sp->port.type == PORT_HSCIF) {
3210 ret = sysfs_create_file(&dev->dev.kobj,
3211 &dev_attr_rx_fifo_timeout.attr);
3213 if (sp->port.fifosize > 1) {
3214 sysfs_remove_file(&dev->dev.kobj,
3215 &dev_attr_rx_fifo_trigger.attr);
3221 #ifdef CONFIG_SH_STANDARD_BIOS
3222 sh_bios_gdb_detach();
3228 static __maybe_unused int sci_suspend(struct device *dev)
3230 struct sci_port *sport = dev_get_drvdata(dev);
3233 uart_suspend_port(&sci_uart_driver, &sport->port);
3238 static __maybe_unused int sci_resume(struct device *dev)
3240 struct sci_port *sport = dev_get_drvdata(dev);
3243 uart_resume_port(&sci_uart_driver, &sport->port);
3248 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3250 static struct platform_driver sci_driver = {
3252 .remove = sci_remove,
3255 .pm = &sci_dev_pm_ops,
3256 .of_match_table = of_match_ptr(of_sci_match),
3260 static int __init sci_init(void)
3262 pr_info("%s\n", banner);
3264 return platform_driver_register(&sci_driver);
3267 static void __exit sci_exit(void)
3269 platform_driver_unregister(&sci_driver);
3271 if (sci_uart_driver.state)
3272 uart_unregister_driver(&sci_uart_driver);
3275 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3276 early_platform_init_buffer("earlyprintk", &sci_driver,
3277 early_serial_buf, ARRAY_SIZE(early_serial_buf));
3279 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3280 static struct plat_sci_port port_cfg __initdata;
3282 static int __init early_console_setup(struct earlycon_device *device,
3285 if (!device->port.membase)
3288 device->port.serial_in = sci_serial_in;
3289 device->port.serial_out = sci_serial_out;
3290 device->port.type = type;
3291 memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3292 port_cfg.type = type;
3293 sci_ports[0].cfg = &port_cfg;
3294 sci_ports[0].params = sci_probe_regmap(&port_cfg);
3295 port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3296 sci_serial_out(&sci_ports[0].port, SCSCR,
3297 SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3299 device->con->write = serial_console_write;
3302 static int __init sci_early_console_setup(struct earlycon_device *device,
3305 return early_console_setup(device, PORT_SCI);
3307 static int __init scif_early_console_setup(struct earlycon_device *device,
3310 return early_console_setup(device, PORT_SCIF);
3312 static int __init scifa_early_console_setup(struct earlycon_device *device,
3315 return early_console_setup(device, PORT_SCIFA);
3317 static int __init scifb_early_console_setup(struct earlycon_device *device,
3320 return early_console_setup(device, PORT_SCIFB);
3322 static int __init hscif_early_console_setup(struct earlycon_device *device,
3325 return early_console_setup(device, PORT_HSCIF);
3328 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3329 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3330 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3331 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3332 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3333 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3335 module_init(sci_init);
3336 module_exit(sci_exit);
3338 MODULE_LICENSE("GPL");
3339 MODULE_ALIAS("platform:sh-sci");
3340 MODULE_AUTHOR("Paul Mundt");
3341 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");