xref: /linux/drivers/tty/serial/sh-sci.c (revision b0d5c81e872ed21de1e56feb0fa6e4161da7be61)
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 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 #define SUPPORT_SYSRQ
20 #endif
21 
22 #undef DEBUG
23 
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>
38 #include <linux/mm.h>
39 #include <linux/of.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>
53 
54 #ifdef CONFIG_SUPERH
55 #include <asm/sh_bios.h>
56 #endif
57 
58 #include "serial_mctrl_gpio.h"
59 #include "sh-sci.h"
60 
61 /* Offsets into the sci_port->irqs array */
62 enum {
63 	SCIx_ERI_IRQ,
64 	SCIx_RXI_IRQ,
65 	SCIx_TXI_IRQ,
66 	SCIx_BRI_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 	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];
143 	void				*rx_buf[2];
144 	size_t				buf_len_rx;
145 	struct work_struct		work_tx;
146 	struct timer_list		rx_timer;
147 	unsigned int			rx_timeout;
148 #endif
149 	unsigned int			rx_frame;
150 	int				rx_trigger;
151 	struct timer_list		rx_fifo_timer;
152 	int				rx_fifo_timeout;
153 	u16				hscif_tot;
154 
155 	bool has_rtscts;
156 	bool autorts;
157 };
158 
159 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
160 
161 static struct sci_port sci_ports[SCI_NPORTS];
162 static struct uart_driver sci_uart_driver;
163 
164 static inline struct sci_port *
165 to_sci_port(struct uart_port *uart)
166 {
167 	return container_of(uart, struct sci_port, port);
168 }
169 
170 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
171 	/*
172 	 * Common SCI definitions, dependent on the port's regshift
173 	 * value.
174 	 */
175 	[SCIx_SCI_REGTYPE] = {
176 		.regs = {
177 			[SCSMR]		= { 0x00,  8 },
178 			[SCBRR]		= { 0x01,  8 },
179 			[SCSCR]		= { 0x02,  8 },
180 			[SCxTDR]	= { 0x03,  8 },
181 			[SCxSR]		= { 0x04,  8 },
182 			[SCxRDR]	= { 0x05,  8 },
183 		},
184 		.fifosize = 1,
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,
190 	},
191 
192 	/*
193 	 * Common definitions for legacy IrDA ports.
194 	 */
195 	[SCIx_IRDA_REGTYPE] = {
196 		.regs = {
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 },
205 		},
206 		.fifosize = 1,
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,
212 	},
213 
214 	/*
215 	 * Common SCIFA definitions.
216 	 */
217 	[SCIx_SCIFA_REGTYPE] = {
218 		.regs = {
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 },
229 		},
230 		.fifosize = 64,
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,
236 	},
237 
238 	/*
239 	 * Common SCIFB definitions.
240 	 */
241 	[SCIx_SCIFB_REGTYPE] = {
242 		.regs = {
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 },
254 		},
255 		.fifosize = 256,
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,
261 	},
262 
263 	/*
264 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
265 	 * count registers.
266 	 */
267 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
268 		.regs = {
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 },
279 		},
280 		.fifosize = 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,
286 	},
287 
288 	/*
289 	 * Common SH-3 SCIF definitions.
290 	 */
291 	[SCIx_SH3_SCIF_REGTYPE] = {
292 		.regs = {
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 },
301 		},
302 		.fifosize = 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,
308 	},
309 
310 	/*
311 	 * Common SH-4(A) SCIF(B) definitions.
312 	 */
313 	[SCIx_SH4_SCIF_REGTYPE] = {
314 		.regs = {
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 },
325 		},
326 		.fifosize = 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,
332 	},
333 
334 	/*
335 	 * Common SCIF definitions for ports with a Baud Rate Generator for
336 	 * External Clock (BRG).
337 	 */
338 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
339 		.regs = {
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 },
352 		},
353 		.fifosize = 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,
359 	},
360 
361 	/*
362 	 * Common HSCIF definitions.
363 	 */
364 	[SCIx_HSCIF_REGTYPE] = {
365 		.regs = {
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 },
381 		},
382 		.fifosize = 128,
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,
388 	},
389 
390 	/*
391 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
392 	 * register.
393 	 */
394 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
395 		.regs = {
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 },
405 		},
406 		.fifosize = 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,
412 	},
413 
414 	/*
415 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
416 	 * count registers.
417 	 */
418 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
419 		.regs = {
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 },
432 		},
433 		.fifosize = 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,
439 	},
440 
441 	/*
442 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
443 	 * registers.
444 	 */
445 	[SCIx_SH7705_SCIF_REGTYPE] = {
446 		.regs = {
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 },
455 		},
456 		.fifosize = 64,
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,
462 	},
463 };
464 
465 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
466 
467 /*
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.
472  */
473 static unsigned int sci_serial_in(struct uart_port *p, int offset)
474 {
475 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
476 
477 	if (reg->size == 8)
478 		return ioread8(p->membase + (reg->offset << p->regshift));
479 	else if (reg->size == 16)
480 		return ioread16(p->membase + (reg->offset << p->regshift));
481 	else
482 		WARN(1, "Invalid register access\n");
483 
484 	return 0;
485 }
486 
487 static void sci_serial_out(struct uart_port *p, int offset, int value)
488 {
489 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
490 
491 	if (reg->size == 8)
492 		iowrite8(value, p->membase + (reg->offset << p->regshift));
493 	else if (reg->size == 16)
494 		iowrite16(value, p->membase + (reg->offset << p->regshift));
495 	else
496 		WARN(1, "Invalid register access\n");
497 }
498 
499 static void sci_port_enable(struct sci_port *sci_port)
500 {
501 	unsigned int i;
502 
503 	if (!sci_port->port.dev)
504 		return;
505 
506 	pm_runtime_get_sync(sci_port->port.dev);
507 
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]);
511 	}
512 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
513 }
514 
515 static void sci_port_disable(struct sci_port *sci_port)
516 {
517 	unsigned int i;
518 
519 	if (!sci_port->port.dev)
520 		return;
521 
522 	for (i = SCI_NUM_CLKS; i-- > 0; )
523 		clk_disable_unprepare(sci_port->clks[i]);
524 
525 	pm_runtime_put_sync(sci_port->port.dev);
526 }
527 
528 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
529 {
530 	/*
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
535 	 * testing for it.
536 	 */
537 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
538 }
539 
540 static void sci_start_tx(struct uart_port *port)
541 {
542 	struct sci_port *s = to_sci_port(port);
543 	unsigned short ctrl;
544 
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);
548 		if (s->chan_tx)
549 			new = scr | SCSCR_TDRQE;
550 		else
551 			new = scr & ~SCSCR_TDRQE;
552 		if (new != scr)
553 			serial_port_out(port, SCSCR, new);
554 	}
555 
556 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
557 	    dma_submit_error(s->cookie_tx)) {
558 		s->cookie_tx = 0;
559 		schedule_work(&s->work_tx);
560 	}
561 #endif
562 
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);
567 	}
568 }
569 
570 static void sci_stop_tx(struct uart_port *port)
571 {
572 	unsigned short ctrl;
573 
574 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
575 	ctrl = serial_port_in(port, SCSCR);
576 
577 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
578 		ctrl &= ~SCSCR_TDRQE;
579 
580 	ctrl &= ~SCSCR_TIE;
581 
582 	serial_port_out(port, SCSCR, ctrl);
583 }
584 
585 static void sci_start_rx(struct uart_port *port)
586 {
587 	unsigned short ctrl;
588 
589 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
590 
591 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
592 		ctrl &= ~SCSCR_RDRQE;
593 
594 	serial_port_out(port, SCSCR, ctrl);
595 }
596 
597 static void sci_stop_rx(struct uart_port *port)
598 {
599 	unsigned short ctrl;
600 
601 	ctrl = serial_port_in(port, SCSCR);
602 
603 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
604 		ctrl &= ~SCSCR_RDRQE;
605 
606 	ctrl &= ~port_rx_irq_mask(port);
607 
608 	serial_port_out(port, SCSCR, ctrl);
609 }
610 
611 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
612 {
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);
621 	} else {
622 		/* Store the mask, clear parity/framing errors */
623 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
624 	}
625 }
626 
627 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
628     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
629 
630 #ifdef CONFIG_CONSOLE_POLL
631 static int sci_poll_get_char(struct uart_port *port)
632 {
633 	unsigned short status;
634 	int c;
635 
636 	do {
637 		status = serial_port_in(port, SCxSR);
638 		if (status & SCxSR_ERRORS(port)) {
639 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
640 			continue;
641 		}
642 		break;
643 	} while (1);
644 
645 	if (!(status & SCxSR_RDxF(port)))
646 		return NO_POLL_CHAR;
647 
648 	c = serial_port_in(port, SCxRDR);
649 
650 	/* Dummy read */
651 	serial_port_in(port, SCxSR);
652 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
653 
654 	return c;
655 }
656 #endif
657 
658 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
659 {
660 	unsigned short status;
661 
662 	do {
663 		status = serial_port_in(port, SCxSR);
664 	} while (!(status & SCxSR_TDxE(port)));
665 
666 	serial_port_out(port, SCxTDR, c);
667 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
668 }
669 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
670 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
671 
672 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
673 {
674 	struct sci_port *s = to_sci_port(port);
675 
676 	/*
677 	 * Use port-specific handler if provided.
678 	 */
679 	if (s->cfg->ops && s->cfg->ops->init_pins) {
680 		s->cfg->ops->init_pins(port, cflag);
681 		return;
682 	}
683 
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);
687 
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)) {
693 				ctrl |= SCPCR_RTSC;
694 				data |= SCPDR_RTSD;
695 			} else if (!s->autorts) {
696 				ctrl |= SCPCR_RTSC;
697 				data &= ~SCPDR_RTSD;
698 			} else {
699 				/* Enable RTS# pin function */
700 				ctrl &= ~SCPCR_RTSC;
701 			}
702 			/* Enable CTS# pin function */
703 			ctrl &= ~SCPCR_CTSC;
704 		}
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);
709 
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);
719 	}
720 }
721 
722 static int sci_txfill(struct uart_port *port)
723 {
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;
727 
728 	reg = sci_getreg(port, SCTFDR);
729 	if (reg->size)
730 		return serial_port_in(port, SCTFDR) & fifo_mask;
731 
732 	reg = sci_getreg(port, SCFDR);
733 	if (reg->size)
734 		return serial_port_in(port, SCFDR) >> 8;
735 
736 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
737 }
738 
739 static int sci_txroom(struct uart_port *port)
740 {
741 	return port->fifosize - sci_txfill(port);
742 }
743 
744 static int sci_rxfill(struct uart_port *port)
745 {
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;
749 
750 	reg = sci_getreg(port, SCRFDR);
751 	if (reg->size)
752 		return serial_port_in(port, SCRFDR) & fifo_mask;
753 
754 	reg = sci_getreg(port, SCFDR);
755 	if (reg->size)
756 		return serial_port_in(port, SCFDR) & fifo_mask;
757 
758 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
759 }
760 
761 /* ********************************************************************** *
762  *                   the interrupt related routines                       *
763  * ********************************************************************** */
764 
765 static void sci_transmit_chars(struct uart_port *port)
766 {
767 	struct circ_buf *xmit = &port->state->xmit;
768 	unsigned int stopped = uart_tx_stopped(port);
769 	unsigned short status;
770 	unsigned short ctrl;
771 	int count;
772 
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))
777 			ctrl &= ~SCSCR_TIE;
778 		else
779 			ctrl |= SCSCR_TIE;
780 		serial_port_out(port, SCSCR, ctrl);
781 		return;
782 	}
783 
784 	count = sci_txroom(port);
785 
786 	do {
787 		unsigned char c;
788 
789 		if (port->x_char) {
790 			c = port->x_char;
791 			port->x_char = 0;
792 		} else if (!uart_circ_empty(xmit) && !stopped) {
793 			c = xmit->buf[xmit->tail];
794 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
795 		} else {
796 			break;
797 		}
798 
799 		serial_port_out(port, SCxTDR, c);
800 
801 		port->icount.tx++;
802 	} while (--count > 0);
803 
804 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
805 
806 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
807 		uart_write_wakeup(port);
808 	if (uart_circ_empty(xmit)) {
809 		sci_stop_tx(port);
810 	} else {
811 		ctrl = serial_port_in(port, SCSCR);
812 
813 		if (port->type != PORT_SCI) {
814 			serial_port_in(port, SCxSR); /* Dummy read */
815 			sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
816 		}
817 
818 		ctrl |= SCSCR_TIE;
819 		serial_port_out(port, SCSCR, ctrl);
820 	}
821 }
822 
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); })
825 
826 static void sci_receive_chars(struct uart_port *port)
827 {
828 	struct tty_port *tport = &port->state->port;
829 	int i, count, copied = 0;
830 	unsigned short status;
831 	unsigned char flag;
832 
833 	status = serial_port_in(port, SCxSR);
834 	if (!(status & SCxSR_RDxF(port)))
835 		return;
836 
837 	while (1) {
838 		/* Don't copy more bytes than there is room for in the buffer */
839 		count = tty_buffer_request_room(tport, sci_rxfill(port));
840 
841 		/* If for any reason we can't copy more data, we're done! */
842 		if (count == 0)
843 			break;
844 
845 		if (port->type == PORT_SCI) {
846 			char c = serial_port_in(port, SCxRDR);
847 			if (uart_handle_sysrq_char(port, c))
848 				count = 0;
849 			else
850 				tty_insert_flip_char(tport, c, TTY_NORMAL);
851 		} else {
852 			for (i = 0; i < count; i++) {
853 				char c = serial_port_in(port, SCxRDR);
854 
855 				status = serial_port_in(port, SCxSR);
856 				if (uart_handle_sysrq_char(port, c)) {
857 					count--; i--;
858 					continue;
859 				}
860 
861 				/* Store data and status */
862 				if (status & SCxSR_FER(port)) {
863 					flag = TTY_FRAME;
864 					port->icount.frame++;
865 					dev_notice(port->dev, "frame error\n");
866 				} else if (status & SCxSR_PER(port)) {
867 					flag = TTY_PARITY;
868 					port->icount.parity++;
869 					dev_notice(port->dev, "parity error\n");
870 				} else
871 					flag = TTY_NORMAL;
872 
873 				tty_insert_flip_char(tport, c, flag);
874 			}
875 		}
876 
877 		serial_port_in(port, SCxSR); /* dummy read */
878 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
879 
880 		copied += count;
881 		port->icount.rx += count;
882 	}
883 
884 	if (copied) {
885 		/* Tell the rest of the system the news. New characters! */
886 		tty_flip_buffer_push(tport);
887 	} else {
888 		/* TTY buffers full; read from RX reg to prevent lockup */
889 		serial_port_in(port, SCxRDR);
890 		serial_port_in(port, SCxSR); /* dummy read */
891 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
892 	}
893 }
894 
895 static int sci_handle_errors(struct uart_port *port)
896 {
897 	int copied = 0;
898 	unsigned short status = serial_port_in(port, SCxSR);
899 	struct tty_port *tport = &port->state->port;
900 	struct sci_port *s = to_sci_port(port);
901 
902 	/* Handle overruns */
903 	if (status & s->params->overrun_mask) {
904 		port->icount.overrun++;
905 
906 		/* overrun error */
907 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
908 			copied++;
909 
910 		dev_notice(port->dev, "overrun error\n");
911 	}
912 
913 	if (status & SCxSR_FER(port)) {
914 		/* frame error */
915 		port->icount.frame++;
916 
917 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
918 			copied++;
919 
920 		dev_notice(port->dev, "frame error\n");
921 	}
922 
923 	if (status & SCxSR_PER(port)) {
924 		/* parity error */
925 		port->icount.parity++;
926 
927 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
928 			copied++;
929 
930 		dev_notice(port->dev, "parity error\n");
931 	}
932 
933 	if (copied)
934 		tty_flip_buffer_push(tport);
935 
936 	return copied;
937 }
938 
939 static int sci_handle_fifo_overrun(struct uart_port *port)
940 {
941 	struct tty_port *tport = &port->state->port;
942 	struct sci_port *s = to_sci_port(port);
943 	const struct plat_sci_reg *reg;
944 	int copied = 0;
945 	u16 status;
946 
947 	reg = sci_getreg(port, s->params->overrun_reg);
948 	if (!reg->size)
949 		return 0;
950 
951 	status = serial_port_in(port, s->params->overrun_reg);
952 	if (status & s->params->overrun_mask) {
953 		status &= ~s->params->overrun_mask;
954 		serial_port_out(port, s->params->overrun_reg, status);
955 
956 		port->icount.overrun++;
957 
958 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
959 		tty_flip_buffer_push(tport);
960 
961 		dev_dbg(port->dev, "overrun error\n");
962 		copied++;
963 	}
964 
965 	return copied;
966 }
967 
968 static int sci_handle_breaks(struct uart_port *port)
969 {
970 	int copied = 0;
971 	unsigned short status = serial_port_in(port, SCxSR);
972 	struct tty_port *tport = &port->state->port;
973 
974 	if (uart_handle_break(port))
975 		return 0;
976 
977 	if (status & SCxSR_BRK(port)) {
978 		port->icount.brk++;
979 
980 		/* Notify of BREAK */
981 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
982 			copied++;
983 
984 		dev_dbg(port->dev, "BREAK detected\n");
985 	}
986 
987 	if (copied)
988 		tty_flip_buffer_push(tport);
989 
990 	copied += sci_handle_fifo_overrun(port);
991 
992 	return copied;
993 }
994 
995 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
996 {
997 	unsigned int bits;
998 
999 	if (rx_trig < 1)
1000 		rx_trig = 1;
1001 	if (rx_trig >= port->fifosize)
1002 		rx_trig = port->fifosize;
1003 
1004 	/* HSCIF can be set to an arbitrary level. */
1005 	if (sci_getreg(port, HSRTRGR)->size) {
1006 		serial_port_out(port, HSRTRGR, rx_trig);
1007 		return rx_trig;
1008 	}
1009 
1010 	switch (port->type) {
1011 	case PORT_SCIF:
1012 		if (rx_trig < 4) {
1013 			bits = 0;
1014 			rx_trig = 1;
1015 		} else if (rx_trig < 8) {
1016 			bits = SCFCR_RTRG0;
1017 			rx_trig = 4;
1018 		} else if (rx_trig < 14) {
1019 			bits = SCFCR_RTRG1;
1020 			rx_trig = 8;
1021 		} else {
1022 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1023 			rx_trig = 14;
1024 		}
1025 		break;
1026 	case PORT_SCIFA:
1027 	case PORT_SCIFB:
1028 		if (rx_trig < 16) {
1029 			bits = 0;
1030 			rx_trig = 1;
1031 		} else if (rx_trig < 32) {
1032 			bits = SCFCR_RTRG0;
1033 			rx_trig = 16;
1034 		} else if (rx_trig < 48) {
1035 			bits = SCFCR_RTRG1;
1036 			rx_trig = 32;
1037 		} else {
1038 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1039 			rx_trig = 48;
1040 		}
1041 		break;
1042 	default:
1043 		WARN(1, "unknown FIFO configuration");
1044 		return 1;
1045 	}
1046 
1047 	serial_port_out(port, SCFCR,
1048 		(serial_port_in(port, SCFCR) &
1049 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1050 
1051 	return rx_trig;
1052 }
1053 
1054 static int scif_rtrg_enabled(struct uart_port *port)
1055 {
1056 	if (sci_getreg(port, HSRTRGR)->size)
1057 		return serial_port_in(port, HSRTRGR) != 0;
1058 	else
1059 		return (serial_port_in(port, SCFCR) &
1060 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1061 }
1062 
1063 static void rx_fifo_timer_fn(struct timer_list *t)
1064 {
1065 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1066 	struct uart_port *port = &s->port;
1067 
1068 	dev_dbg(port->dev, "Rx timed out\n");
1069 	scif_set_rtrg(port, 1);
1070 }
1071 
1072 static ssize_t rx_trigger_show(struct device *dev,
1073 			       struct device_attribute *attr,
1074 			       char *buf)
1075 {
1076 	struct uart_port *port = dev_get_drvdata(dev);
1077 	struct sci_port *sci = to_sci_port(port);
1078 
1079 	return sprintf(buf, "%d\n", sci->rx_trigger);
1080 }
1081 
1082 static ssize_t rx_trigger_store(struct device *dev,
1083 				struct device_attribute *attr,
1084 				const char *buf,
1085 				size_t count)
1086 {
1087 	struct uart_port *port = dev_get_drvdata(dev);
1088 	struct sci_port *sci = to_sci_port(port);
1089 	int ret;
1090 	long r;
1091 
1092 	ret = kstrtol(buf, 0, &r);
1093 	if (ret)
1094 		return ret;
1095 
1096 	sci->rx_trigger = scif_set_rtrg(port, r);
1097 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1098 		scif_set_rtrg(port, 1);
1099 
1100 	return count;
1101 }
1102 
1103 static DEVICE_ATTR(rx_fifo_trigger, 0644, rx_trigger_show, rx_trigger_store);
1104 
1105 static ssize_t rx_fifo_timeout_show(struct device *dev,
1106 			       struct device_attribute *attr,
1107 			       char *buf)
1108 {
1109 	struct uart_port *port = dev_get_drvdata(dev);
1110 	struct sci_port *sci = to_sci_port(port);
1111 	int v;
1112 
1113 	if (port->type == PORT_HSCIF)
1114 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1115 	else
1116 		v = sci->rx_fifo_timeout;
1117 
1118 	return sprintf(buf, "%d\n", v);
1119 }
1120 
1121 static ssize_t rx_fifo_timeout_store(struct device *dev,
1122 				struct device_attribute *attr,
1123 				const char *buf,
1124 				size_t count)
1125 {
1126 	struct uart_port *port = dev_get_drvdata(dev);
1127 	struct sci_port *sci = to_sci_port(port);
1128 	int ret;
1129 	long r;
1130 
1131 	ret = kstrtol(buf, 0, &r);
1132 	if (ret)
1133 		return ret;
1134 
1135 	if (port->type == PORT_HSCIF) {
1136 		if (r < 0 || r > 3)
1137 			return -EINVAL;
1138 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1139 	} else {
1140 		sci->rx_fifo_timeout = r;
1141 		scif_set_rtrg(port, 1);
1142 		if (r > 0)
1143 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1144 	}
1145 
1146 	return count;
1147 }
1148 
1149 static DEVICE_ATTR_RW(rx_fifo_timeout);
1150 
1151 
1152 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1153 static void sci_dma_tx_complete(void *arg)
1154 {
1155 	struct sci_port *s = arg;
1156 	struct uart_port *port = &s->port;
1157 	struct circ_buf *xmit = &port->state->xmit;
1158 	unsigned long flags;
1159 
1160 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1161 
1162 	spin_lock_irqsave(&port->lock, flags);
1163 
1164 	xmit->tail += s->tx_dma_len;
1165 	xmit->tail &= UART_XMIT_SIZE - 1;
1166 
1167 	port->icount.tx += s->tx_dma_len;
1168 
1169 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1170 		uart_write_wakeup(port);
1171 
1172 	if (!uart_circ_empty(xmit)) {
1173 		s->cookie_tx = 0;
1174 		schedule_work(&s->work_tx);
1175 	} else {
1176 		s->cookie_tx = -EINVAL;
1177 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1178 			u16 ctrl = serial_port_in(port, SCSCR);
1179 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1180 		}
1181 	}
1182 
1183 	spin_unlock_irqrestore(&port->lock, flags);
1184 }
1185 
1186 /* Locking: called with port lock held */
1187 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1188 {
1189 	struct uart_port *port = &s->port;
1190 	struct tty_port *tport = &port->state->port;
1191 	int copied;
1192 
1193 	copied = tty_insert_flip_string(tport, buf, count);
1194 	if (copied < count)
1195 		port->icount.buf_overrun++;
1196 
1197 	port->icount.rx += copied;
1198 
1199 	return copied;
1200 }
1201 
1202 static int sci_dma_rx_find_active(struct sci_port *s)
1203 {
1204 	unsigned int i;
1205 
1206 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1207 		if (s->active_rx == s->cookie_rx[i])
1208 			return i;
1209 
1210 	return -1;
1211 }
1212 
1213 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1214 {
1215 	struct dma_chan *chan = s->chan_rx;
1216 	struct uart_port *port = &s->port;
1217 	unsigned long flags;
1218 
1219 	spin_lock_irqsave(&port->lock, flags);
1220 	s->chan_rx = NULL;
1221 	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1222 	spin_unlock_irqrestore(&port->lock, flags);
1223 	dmaengine_terminate_all(chan);
1224 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1225 			  sg_dma_address(&s->sg_rx[0]));
1226 	dma_release_channel(chan);
1227 	if (enable_pio) {
1228 		spin_lock_irqsave(&port->lock, flags);
1229 		sci_start_rx(port);
1230 		spin_unlock_irqrestore(&port->lock, flags);
1231 	}
1232 }
1233 
1234 static void sci_dma_rx_complete(void *arg)
1235 {
1236 	struct sci_port *s = arg;
1237 	struct dma_chan *chan = s->chan_rx;
1238 	struct uart_port *port = &s->port;
1239 	struct dma_async_tx_descriptor *desc;
1240 	unsigned long flags;
1241 	int active, count = 0;
1242 
1243 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1244 		s->active_rx);
1245 
1246 	spin_lock_irqsave(&port->lock, flags);
1247 
1248 	active = sci_dma_rx_find_active(s);
1249 	if (active >= 0)
1250 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1251 
1252 	mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1253 
1254 	if (count)
1255 		tty_flip_buffer_push(&port->state->port);
1256 
1257 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1258 				       DMA_DEV_TO_MEM,
1259 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1260 	if (!desc)
1261 		goto fail;
1262 
1263 	desc->callback = sci_dma_rx_complete;
1264 	desc->callback_param = s;
1265 	s->cookie_rx[active] = dmaengine_submit(desc);
1266 	if (dma_submit_error(s->cookie_rx[active]))
1267 		goto fail;
1268 
1269 	s->active_rx = s->cookie_rx[!active];
1270 
1271 	dma_async_issue_pending(chan);
1272 
1273 	spin_unlock_irqrestore(&port->lock, flags);
1274 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1275 		__func__, s->cookie_rx[active], active, s->active_rx);
1276 	return;
1277 
1278 fail:
1279 	spin_unlock_irqrestore(&port->lock, flags);
1280 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1281 	sci_rx_dma_release(s, true);
1282 }
1283 
1284 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1285 {
1286 	struct dma_chan *chan = s->chan_tx;
1287 	struct uart_port *port = &s->port;
1288 	unsigned long flags;
1289 
1290 	spin_lock_irqsave(&port->lock, flags);
1291 	s->chan_tx = NULL;
1292 	s->cookie_tx = -EINVAL;
1293 	spin_unlock_irqrestore(&port->lock, flags);
1294 	dmaengine_terminate_all(chan);
1295 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1296 			 DMA_TO_DEVICE);
1297 	dma_release_channel(chan);
1298 	if (enable_pio) {
1299 		spin_lock_irqsave(&port->lock, flags);
1300 		sci_start_tx(port);
1301 		spin_unlock_irqrestore(&port->lock, flags);
1302 	}
1303 }
1304 
1305 static void sci_submit_rx(struct sci_port *s)
1306 {
1307 	struct dma_chan *chan = s->chan_rx;
1308 	int i;
1309 
1310 	for (i = 0; i < 2; i++) {
1311 		struct scatterlist *sg = &s->sg_rx[i];
1312 		struct dma_async_tx_descriptor *desc;
1313 
1314 		desc = dmaengine_prep_slave_sg(chan,
1315 			sg, 1, DMA_DEV_TO_MEM,
1316 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1317 		if (!desc)
1318 			goto fail;
1319 
1320 		desc->callback = sci_dma_rx_complete;
1321 		desc->callback_param = s;
1322 		s->cookie_rx[i] = dmaengine_submit(desc);
1323 		if (dma_submit_error(s->cookie_rx[i]))
1324 			goto fail;
1325 
1326 	}
1327 
1328 	s->active_rx = s->cookie_rx[0];
1329 
1330 	dma_async_issue_pending(chan);
1331 	return;
1332 
1333 fail:
1334 	if (i)
1335 		dmaengine_terminate_all(chan);
1336 	for (i = 0; i < 2; i++)
1337 		s->cookie_rx[i] = -EINVAL;
1338 	s->active_rx = -EINVAL;
1339 	sci_rx_dma_release(s, true);
1340 }
1341 
1342 static void work_fn_tx(struct work_struct *work)
1343 {
1344 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1345 	struct dma_async_tx_descriptor *desc;
1346 	struct dma_chan *chan = s->chan_tx;
1347 	struct uart_port *port = &s->port;
1348 	struct circ_buf *xmit = &port->state->xmit;
1349 	dma_addr_t buf;
1350 
1351 	/*
1352 	 * DMA is idle now.
1353 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1354 	 * offsets and lengths. Since it is a circular buffer, we have to
1355 	 * transmit till the end, and then the rest. Take the port lock to get a
1356 	 * consistent xmit buffer state.
1357 	 */
1358 	spin_lock_irq(&port->lock);
1359 	buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1360 	s->tx_dma_len = min_t(unsigned int,
1361 		CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1362 		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1363 	spin_unlock_irq(&port->lock);
1364 
1365 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1366 					   DMA_MEM_TO_DEV,
1367 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1368 	if (!desc) {
1369 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1370 		/* switch to PIO */
1371 		sci_tx_dma_release(s, true);
1372 		return;
1373 	}
1374 
1375 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1376 				   DMA_TO_DEVICE);
1377 
1378 	spin_lock_irq(&port->lock);
1379 	desc->callback = sci_dma_tx_complete;
1380 	desc->callback_param = s;
1381 	spin_unlock_irq(&port->lock);
1382 	s->cookie_tx = dmaengine_submit(desc);
1383 	if (dma_submit_error(s->cookie_tx)) {
1384 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1385 		/* switch to PIO */
1386 		sci_tx_dma_release(s, true);
1387 		return;
1388 	}
1389 
1390 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1391 		__func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1392 
1393 	dma_async_issue_pending(chan);
1394 }
1395 
1396 static void rx_timer_fn(struct timer_list *t)
1397 {
1398 	struct sci_port *s = from_timer(s, t, rx_timer);
1399 	struct dma_chan *chan = s->chan_rx;
1400 	struct uart_port *port = &s->port;
1401 	struct dma_tx_state state;
1402 	enum dma_status status;
1403 	unsigned long flags;
1404 	unsigned int read;
1405 	int active, count;
1406 	u16 scr;
1407 
1408 	dev_dbg(port->dev, "DMA Rx timed out\n");
1409 
1410 	spin_lock_irqsave(&port->lock, flags);
1411 
1412 	active = sci_dma_rx_find_active(s);
1413 	if (active < 0) {
1414 		spin_unlock_irqrestore(&port->lock, flags);
1415 		return;
1416 	}
1417 
1418 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1419 	if (status == DMA_COMPLETE) {
1420 		spin_unlock_irqrestore(&port->lock, flags);
1421 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1422 			s->active_rx, active);
1423 
1424 		/* Let packet complete handler take care of the packet */
1425 		return;
1426 	}
1427 
1428 	dmaengine_pause(chan);
1429 
1430 	/*
1431 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1432 	 * data keeps on coming until transaction is complete so check
1433 	 * for DMA_COMPLETE again
1434 	 * Let packet complete handler take care of the packet
1435 	 */
1436 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1437 	if (status == DMA_COMPLETE) {
1438 		spin_unlock_irqrestore(&port->lock, flags);
1439 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1440 		return;
1441 	}
1442 
1443 	/* Handle incomplete DMA receive */
1444 	dmaengine_terminate_all(s->chan_rx);
1445 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1446 
1447 	if (read) {
1448 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1449 		if (count)
1450 			tty_flip_buffer_push(&port->state->port);
1451 	}
1452 
1453 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1454 		sci_submit_rx(s);
1455 
1456 	/* Direct new serial port interrupts back to CPU */
1457 	scr = serial_port_in(port, SCSCR);
1458 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1459 		scr &= ~SCSCR_RDRQE;
1460 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1461 	}
1462 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1463 
1464 	spin_unlock_irqrestore(&port->lock, flags);
1465 }
1466 
1467 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1468 					     enum dma_transfer_direction dir)
1469 {
1470 	struct dma_chan *chan;
1471 	struct dma_slave_config cfg;
1472 	int ret;
1473 
1474 	chan = dma_request_slave_channel(port->dev,
1475 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1476 	if (!chan) {
1477 		dev_warn(port->dev, "dma_request_slave_channel failed\n");
1478 		return NULL;
1479 	}
1480 
1481 	memset(&cfg, 0, sizeof(cfg));
1482 	cfg.direction = dir;
1483 	if (dir == DMA_MEM_TO_DEV) {
1484 		cfg.dst_addr = port->mapbase +
1485 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1486 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1487 	} else {
1488 		cfg.src_addr = port->mapbase +
1489 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1490 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1491 	}
1492 
1493 	ret = dmaengine_slave_config(chan, &cfg);
1494 	if (ret) {
1495 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1496 		dma_release_channel(chan);
1497 		return NULL;
1498 	}
1499 
1500 	return chan;
1501 }
1502 
1503 static void sci_request_dma(struct uart_port *port)
1504 {
1505 	struct sci_port *s = to_sci_port(port);
1506 	struct dma_chan *chan;
1507 
1508 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1509 
1510 	if (!port->dev->of_node)
1511 		return;
1512 
1513 	s->cookie_tx = -EINVAL;
1514 
1515 	/*
1516 	 * Don't request a dma channel if no channel was specified
1517 	 * in the device tree.
1518 	 */
1519 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1520 		return;
1521 
1522 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1523 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1524 	if (chan) {
1525 		s->chan_tx = chan;
1526 		/* UART circular tx buffer is an aligned page. */
1527 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1528 						port->state->xmit.buf,
1529 						UART_XMIT_SIZE,
1530 						DMA_TO_DEVICE);
1531 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1532 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1533 			dma_release_channel(chan);
1534 			s->chan_tx = NULL;
1535 		} else {
1536 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1537 				__func__, UART_XMIT_SIZE,
1538 				port->state->xmit.buf, &s->tx_dma_addr);
1539 		}
1540 
1541 		INIT_WORK(&s->work_tx, work_fn_tx);
1542 	}
1543 
1544 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1545 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1546 	if (chan) {
1547 		unsigned int i;
1548 		dma_addr_t dma;
1549 		void *buf;
1550 
1551 		s->chan_rx = chan;
1552 
1553 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1554 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1555 					 &dma, GFP_KERNEL);
1556 		if (!buf) {
1557 			dev_warn(port->dev,
1558 				 "Failed to allocate Rx dma buffer, using PIO\n");
1559 			dma_release_channel(chan);
1560 			s->chan_rx = NULL;
1561 			return;
1562 		}
1563 
1564 		for (i = 0; i < 2; i++) {
1565 			struct scatterlist *sg = &s->sg_rx[i];
1566 
1567 			sg_init_table(sg, 1);
1568 			s->rx_buf[i] = buf;
1569 			sg_dma_address(sg) = dma;
1570 			sg_dma_len(sg) = s->buf_len_rx;
1571 
1572 			buf += s->buf_len_rx;
1573 			dma += s->buf_len_rx;
1574 		}
1575 
1576 		timer_setup(&s->rx_timer, rx_timer_fn, 0);
1577 
1578 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1579 			sci_submit_rx(s);
1580 	}
1581 }
1582 
1583 static void sci_free_dma(struct uart_port *port)
1584 {
1585 	struct sci_port *s = to_sci_port(port);
1586 
1587 	if (s->chan_tx)
1588 		sci_tx_dma_release(s, false);
1589 	if (s->chan_rx)
1590 		sci_rx_dma_release(s, false);
1591 }
1592 
1593 static void sci_flush_buffer(struct uart_port *port)
1594 {
1595 	/*
1596 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1597 	 * cleared, so we have to reset tx_dma_len accordingly.
1598 	 */
1599 	to_sci_port(port)->tx_dma_len = 0;
1600 }
1601 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1602 static inline void sci_request_dma(struct uart_port *port)
1603 {
1604 }
1605 
1606 static inline void sci_free_dma(struct uart_port *port)
1607 {
1608 }
1609 
1610 #define sci_flush_buffer	NULL
1611 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1612 
1613 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1614 {
1615 	struct uart_port *port = ptr;
1616 	struct sci_port *s = to_sci_port(port);
1617 
1618 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1619 	if (s->chan_rx) {
1620 		u16 scr = serial_port_in(port, SCSCR);
1621 		u16 ssr = serial_port_in(port, SCxSR);
1622 
1623 		/* Disable future Rx interrupts */
1624 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1625 			disable_irq_nosync(irq);
1626 			scr |= SCSCR_RDRQE;
1627 		} else {
1628 			scr &= ~SCSCR_RIE;
1629 			sci_submit_rx(s);
1630 		}
1631 		serial_port_out(port, SCSCR, scr);
1632 		/* Clear current interrupt */
1633 		serial_port_out(port, SCxSR,
1634 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1635 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
1636 			jiffies, s->rx_timeout);
1637 		mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1638 
1639 		return IRQ_HANDLED;
1640 	}
1641 #endif
1642 
1643 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1644 		if (!scif_rtrg_enabled(port))
1645 			scif_set_rtrg(port, s->rx_trigger);
1646 
1647 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1648 			  s->rx_frame * s->rx_fifo_timeout, 1000));
1649 	}
1650 
1651 	/* I think sci_receive_chars has to be called irrespective
1652 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1653 	 * to be disabled?
1654 	 */
1655 	sci_receive_chars(ptr);
1656 
1657 	return IRQ_HANDLED;
1658 }
1659 
1660 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1661 {
1662 	struct uart_port *port = ptr;
1663 	unsigned long flags;
1664 
1665 	spin_lock_irqsave(&port->lock, flags);
1666 	sci_transmit_chars(port);
1667 	spin_unlock_irqrestore(&port->lock, flags);
1668 
1669 	return IRQ_HANDLED;
1670 }
1671 
1672 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1673 {
1674 	struct uart_port *port = ptr;
1675 	struct sci_port *s = to_sci_port(port);
1676 
1677 	/* Handle errors */
1678 	if (port->type == PORT_SCI) {
1679 		if (sci_handle_errors(port)) {
1680 			/* discard character in rx buffer */
1681 			serial_port_in(port, SCxSR);
1682 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1683 		}
1684 	} else {
1685 		sci_handle_fifo_overrun(port);
1686 		if (!s->chan_rx)
1687 			sci_receive_chars(ptr);
1688 	}
1689 
1690 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1691 
1692 	/* Kick the transmission */
1693 	if (!s->chan_tx)
1694 		sci_tx_interrupt(irq, ptr);
1695 
1696 	return IRQ_HANDLED;
1697 }
1698 
1699 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1700 {
1701 	struct uart_port *port = ptr;
1702 
1703 	/* Handle BREAKs */
1704 	sci_handle_breaks(port);
1705 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1706 
1707 	return IRQ_HANDLED;
1708 }
1709 
1710 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1711 {
1712 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1713 	struct uart_port *port = ptr;
1714 	struct sci_port *s = to_sci_port(port);
1715 	irqreturn_t ret = IRQ_NONE;
1716 
1717 	ssr_status = serial_port_in(port, SCxSR);
1718 	scr_status = serial_port_in(port, SCSCR);
1719 	if (s->params->overrun_reg == SCxSR)
1720 		orer_status = ssr_status;
1721 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1722 		orer_status = serial_port_in(port, s->params->overrun_reg);
1723 
1724 	err_enabled = scr_status & port_rx_irq_mask(port);
1725 
1726 	/* Tx Interrupt */
1727 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1728 	    !s->chan_tx)
1729 		ret = sci_tx_interrupt(irq, ptr);
1730 
1731 	/*
1732 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1733 	 * DR flags
1734 	 */
1735 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1736 	    (scr_status & SCSCR_RIE))
1737 		ret = sci_rx_interrupt(irq, ptr);
1738 
1739 	/* Error Interrupt */
1740 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1741 		ret = sci_er_interrupt(irq, ptr);
1742 
1743 	/* Break Interrupt */
1744 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1745 		ret = sci_br_interrupt(irq, ptr);
1746 
1747 	/* Overrun Interrupt */
1748 	if (orer_status & s->params->overrun_mask) {
1749 		sci_handle_fifo_overrun(port);
1750 		ret = IRQ_HANDLED;
1751 	}
1752 
1753 	return ret;
1754 }
1755 
1756 static const struct sci_irq_desc {
1757 	const char	*desc;
1758 	irq_handler_t	handler;
1759 } sci_irq_desc[] = {
1760 	/*
1761 	 * Split out handlers, the default case.
1762 	 */
1763 	[SCIx_ERI_IRQ] = {
1764 		.desc = "rx err",
1765 		.handler = sci_er_interrupt,
1766 	},
1767 
1768 	[SCIx_RXI_IRQ] = {
1769 		.desc = "rx full",
1770 		.handler = sci_rx_interrupt,
1771 	},
1772 
1773 	[SCIx_TXI_IRQ] = {
1774 		.desc = "tx empty",
1775 		.handler = sci_tx_interrupt,
1776 	},
1777 
1778 	[SCIx_BRI_IRQ] = {
1779 		.desc = "break",
1780 		.handler = sci_br_interrupt,
1781 	},
1782 
1783 	/*
1784 	 * Special muxed handler.
1785 	 */
1786 	[SCIx_MUX_IRQ] = {
1787 		.desc = "mux",
1788 		.handler = sci_mpxed_interrupt,
1789 	},
1790 };
1791 
1792 static int sci_request_irq(struct sci_port *port)
1793 {
1794 	struct uart_port *up = &port->port;
1795 	int i, j, ret = 0;
1796 
1797 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1798 		const struct sci_irq_desc *desc;
1799 		int irq;
1800 
1801 		if (SCIx_IRQ_IS_MUXED(port)) {
1802 			i = SCIx_MUX_IRQ;
1803 			irq = up->irq;
1804 		} else {
1805 			irq = port->irqs[i];
1806 
1807 			/*
1808 			 * Certain port types won't support all of the
1809 			 * available interrupt sources.
1810 			 */
1811 			if (unlikely(irq < 0))
1812 				continue;
1813 		}
1814 
1815 		desc = sci_irq_desc + i;
1816 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1817 					    dev_name(up->dev), desc->desc);
1818 		if (!port->irqstr[j]) {
1819 			ret = -ENOMEM;
1820 			goto out_nomem;
1821 		}
1822 
1823 		ret = request_irq(irq, desc->handler, up->irqflags,
1824 				  port->irqstr[j], port);
1825 		if (unlikely(ret)) {
1826 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1827 			goto out_noirq;
1828 		}
1829 	}
1830 
1831 	return 0;
1832 
1833 out_noirq:
1834 	while (--i >= 0)
1835 		free_irq(port->irqs[i], port);
1836 
1837 out_nomem:
1838 	while (--j >= 0)
1839 		kfree(port->irqstr[j]);
1840 
1841 	return ret;
1842 }
1843 
1844 static void sci_free_irq(struct sci_port *port)
1845 {
1846 	int i;
1847 
1848 	/*
1849 	 * Intentionally in reverse order so we iterate over the muxed
1850 	 * IRQ first.
1851 	 */
1852 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1853 		int irq = port->irqs[i];
1854 
1855 		/*
1856 		 * Certain port types won't support all of the available
1857 		 * interrupt sources.
1858 		 */
1859 		if (unlikely(irq < 0))
1860 			continue;
1861 
1862 		free_irq(port->irqs[i], port);
1863 		kfree(port->irqstr[i]);
1864 
1865 		if (SCIx_IRQ_IS_MUXED(port)) {
1866 			/* If there's only one IRQ, we're done. */
1867 			return;
1868 		}
1869 	}
1870 }
1871 
1872 static unsigned int sci_tx_empty(struct uart_port *port)
1873 {
1874 	unsigned short status = serial_port_in(port, SCxSR);
1875 	unsigned short in_tx_fifo = sci_txfill(port);
1876 
1877 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1878 }
1879 
1880 static void sci_set_rts(struct uart_port *port, bool state)
1881 {
1882 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1883 		u16 data = serial_port_in(port, SCPDR);
1884 
1885 		/* Active low */
1886 		if (state)
1887 			data &= ~SCPDR_RTSD;
1888 		else
1889 			data |= SCPDR_RTSD;
1890 		serial_port_out(port, SCPDR, data);
1891 
1892 		/* RTS# is output */
1893 		serial_port_out(port, SCPCR,
1894 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
1895 	} else if (sci_getreg(port, SCSPTR)->size) {
1896 		u16 ctrl = serial_port_in(port, SCSPTR);
1897 
1898 		/* Active low */
1899 		if (state)
1900 			ctrl &= ~SCSPTR_RTSDT;
1901 		else
1902 			ctrl |= SCSPTR_RTSDT;
1903 		serial_port_out(port, SCSPTR, ctrl);
1904 	}
1905 }
1906 
1907 static bool sci_get_cts(struct uart_port *port)
1908 {
1909 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1910 		/* Active low */
1911 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
1912 	} else if (sci_getreg(port, SCSPTR)->size) {
1913 		/* Active low */
1914 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
1915 	}
1916 
1917 	return true;
1918 }
1919 
1920 /*
1921  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1922  * CTS/RTS is supported in hardware by at least one port and controlled
1923  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1924  * handled via the ->init_pins() op, which is a bit of a one-way street,
1925  * lacking any ability to defer pin control -- this will later be
1926  * converted over to the GPIO framework).
1927  *
1928  * Other modes (such as loopback) are supported generically on certain
1929  * port types, but not others. For these it's sufficient to test for the
1930  * existence of the support register and simply ignore the port type.
1931  */
1932 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1933 {
1934 	struct sci_port *s = to_sci_port(port);
1935 
1936 	if (mctrl & TIOCM_LOOP) {
1937 		const struct plat_sci_reg *reg;
1938 
1939 		/*
1940 		 * Standard loopback mode for SCFCR ports.
1941 		 */
1942 		reg = sci_getreg(port, SCFCR);
1943 		if (reg->size)
1944 			serial_port_out(port, SCFCR,
1945 					serial_port_in(port, SCFCR) |
1946 					SCFCR_LOOP);
1947 	}
1948 
1949 	mctrl_gpio_set(s->gpios, mctrl);
1950 
1951 	if (!s->has_rtscts)
1952 		return;
1953 
1954 	if (!(mctrl & TIOCM_RTS)) {
1955 		/* Disable Auto RTS */
1956 		serial_port_out(port, SCFCR,
1957 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
1958 
1959 		/* Clear RTS */
1960 		sci_set_rts(port, 0);
1961 	} else if (s->autorts) {
1962 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1963 			/* Enable RTS# pin function */
1964 			serial_port_out(port, SCPCR,
1965 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
1966 		}
1967 
1968 		/* Enable Auto RTS */
1969 		serial_port_out(port, SCFCR,
1970 				serial_port_in(port, SCFCR) | SCFCR_MCE);
1971 	} else {
1972 		/* Set RTS */
1973 		sci_set_rts(port, 1);
1974 	}
1975 }
1976 
1977 static unsigned int sci_get_mctrl(struct uart_port *port)
1978 {
1979 	struct sci_port *s = to_sci_port(port);
1980 	struct mctrl_gpios *gpios = s->gpios;
1981 	unsigned int mctrl = 0;
1982 
1983 	mctrl_gpio_get(gpios, &mctrl);
1984 
1985 	/*
1986 	 * CTS/RTS is handled in hardware when supported, while nothing
1987 	 * else is wired up.
1988 	 */
1989 	if (s->autorts) {
1990 		if (sci_get_cts(port))
1991 			mctrl |= TIOCM_CTS;
1992 	} else if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS))) {
1993 		mctrl |= TIOCM_CTS;
1994 	}
1995 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))
1996 		mctrl |= TIOCM_DSR;
1997 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))
1998 		mctrl |= TIOCM_CAR;
1999 
2000 	return mctrl;
2001 }
2002 
2003 static void sci_enable_ms(struct uart_port *port)
2004 {
2005 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2006 }
2007 
2008 static void sci_break_ctl(struct uart_port *port, int break_state)
2009 {
2010 	unsigned short scscr, scsptr;
2011 	unsigned long flags;
2012 
2013 	/* check wheter the port has SCSPTR */
2014 	if (!sci_getreg(port, SCSPTR)->size) {
2015 		/*
2016 		 * Not supported by hardware. Most parts couple break and rx
2017 		 * interrupts together, with break detection always enabled.
2018 		 */
2019 		return;
2020 	}
2021 
2022 	spin_lock_irqsave(&port->lock, flags);
2023 	scsptr = serial_port_in(port, SCSPTR);
2024 	scscr = serial_port_in(port, SCSCR);
2025 
2026 	if (break_state == -1) {
2027 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2028 		scscr &= ~SCSCR_TE;
2029 	} else {
2030 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2031 		scscr |= SCSCR_TE;
2032 	}
2033 
2034 	serial_port_out(port, SCSPTR, scsptr);
2035 	serial_port_out(port, SCSCR, scscr);
2036 	spin_unlock_irqrestore(&port->lock, flags);
2037 }
2038 
2039 static int sci_startup(struct uart_port *port)
2040 {
2041 	struct sci_port *s = to_sci_port(port);
2042 	int ret;
2043 
2044 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2045 
2046 	sci_request_dma(port);
2047 
2048 	ret = sci_request_irq(s);
2049 	if (unlikely(ret < 0)) {
2050 		sci_free_dma(port);
2051 		return ret;
2052 	}
2053 
2054 	return 0;
2055 }
2056 
2057 static void sci_shutdown(struct uart_port *port)
2058 {
2059 	struct sci_port *s = to_sci_port(port);
2060 	unsigned long flags;
2061 	u16 scr;
2062 
2063 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2064 
2065 	s->autorts = false;
2066 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2067 
2068 	spin_lock_irqsave(&port->lock, flags);
2069 	sci_stop_rx(port);
2070 	sci_stop_tx(port);
2071 	/*
2072 	 * Stop RX and TX, disable related interrupts, keep clock source
2073 	 * and HSCIF TOT bits
2074 	 */
2075 	scr = serial_port_in(port, SCSCR);
2076 	serial_port_out(port, SCSCR, scr &
2077 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2078 	spin_unlock_irqrestore(&port->lock, flags);
2079 
2080 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2081 	if (s->chan_rx) {
2082 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2083 			port->line);
2084 		del_timer_sync(&s->rx_timer);
2085 	}
2086 #endif
2087 
2088 	sci_free_irq(s);
2089 	sci_free_dma(port);
2090 }
2091 
2092 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2093 			unsigned int *srr)
2094 {
2095 	unsigned long freq = s->clk_rates[SCI_SCK];
2096 	int err, min_err = INT_MAX;
2097 	unsigned int sr;
2098 
2099 	if (s->port.type != PORT_HSCIF)
2100 		freq *= 2;
2101 
2102 	for_each_sr(sr, s) {
2103 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2104 		if (abs(err) >= abs(min_err))
2105 			continue;
2106 
2107 		min_err = err;
2108 		*srr = sr - 1;
2109 
2110 		if (!err)
2111 			break;
2112 	}
2113 
2114 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2115 		*srr + 1);
2116 	return min_err;
2117 }
2118 
2119 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2120 			unsigned long freq, unsigned int *dlr,
2121 			unsigned int *srr)
2122 {
2123 	int err, min_err = INT_MAX;
2124 	unsigned int sr, dl;
2125 
2126 	if (s->port.type != PORT_HSCIF)
2127 		freq *= 2;
2128 
2129 	for_each_sr(sr, s) {
2130 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2131 		dl = clamp(dl, 1U, 65535U);
2132 
2133 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2134 		if (abs(err) >= abs(min_err))
2135 			continue;
2136 
2137 		min_err = err;
2138 		*dlr = dl;
2139 		*srr = sr - 1;
2140 
2141 		if (!err)
2142 			break;
2143 	}
2144 
2145 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2146 		min_err, *dlr, *srr + 1);
2147 	return min_err;
2148 }
2149 
2150 /* calculate sample rate, BRR, and clock select */
2151 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2152 			  unsigned int *brr, unsigned int *srr,
2153 			  unsigned int *cks)
2154 {
2155 	unsigned long freq = s->clk_rates[SCI_FCK];
2156 	unsigned int sr, br, prediv, scrate, c;
2157 	int err, min_err = INT_MAX;
2158 
2159 	if (s->port.type != PORT_HSCIF)
2160 		freq *= 2;
2161 
2162 	/*
2163 	 * Find the combination of sample rate and clock select with the
2164 	 * smallest deviation from the desired baud rate.
2165 	 * Prefer high sample rates to maximise the receive margin.
2166 	 *
2167 	 * M: Receive margin (%)
2168 	 * N: Ratio of bit rate to clock (N = sampling rate)
2169 	 * D: Clock duty (D = 0 to 1.0)
2170 	 * L: Frame length (L = 9 to 12)
2171 	 * F: Absolute value of clock frequency deviation
2172 	 *
2173 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2174 	 *      (|D - 0.5| / N * (1 + F))|
2175 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2176 	 */
2177 	for_each_sr(sr, s) {
2178 		for (c = 0; c <= 3; c++) {
2179 			/* integerized formulas from HSCIF documentation */
2180 			prediv = sr * (1 << (2 * c + 1));
2181 
2182 			/*
2183 			 * We need to calculate:
2184 			 *
2185 			 *     br = freq / (prediv * bps) clamped to [1..256]
2186 			 *     err = freq / (br * prediv) - bps
2187 			 *
2188 			 * Watch out for overflow when calculating the desired
2189 			 * sampling clock rate!
2190 			 */
2191 			if (bps > UINT_MAX / prediv)
2192 				break;
2193 
2194 			scrate = prediv * bps;
2195 			br = DIV_ROUND_CLOSEST(freq, scrate);
2196 			br = clamp(br, 1U, 256U);
2197 
2198 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2199 			if (abs(err) >= abs(min_err))
2200 				continue;
2201 
2202 			min_err = err;
2203 			*brr = br - 1;
2204 			*srr = sr - 1;
2205 			*cks = c;
2206 
2207 			if (!err)
2208 				goto found;
2209 		}
2210 	}
2211 
2212 found:
2213 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2214 		min_err, *brr, *srr + 1, *cks);
2215 	return min_err;
2216 }
2217 
2218 static void sci_reset(struct uart_port *port)
2219 {
2220 	const struct plat_sci_reg *reg;
2221 	unsigned int status;
2222 	struct sci_port *s = to_sci_port(port);
2223 
2224 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2225 
2226 	reg = sci_getreg(port, SCFCR);
2227 	if (reg->size)
2228 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2229 
2230 	sci_clear_SCxSR(port,
2231 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2232 			SCxSR_BREAK_CLEAR(port));
2233 	if (sci_getreg(port, SCLSR)->size) {
2234 		status = serial_port_in(port, SCLSR);
2235 		status &= ~(SCLSR_TO | SCLSR_ORER);
2236 		serial_port_out(port, SCLSR, status);
2237 	}
2238 
2239 	if (s->rx_trigger > 1) {
2240 		if (s->rx_fifo_timeout) {
2241 			scif_set_rtrg(port, 1);
2242 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2243 		} else {
2244 			if (port->type == PORT_SCIFA ||
2245 			    port->type == PORT_SCIFB)
2246 				scif_set_rtrg(port, 1);
2247 			else
2248 				scif_set_rtrg(port, s->rx_trigger);
2249 		}
2250 	}
2251 }
2252 
2253 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2254 			    struct ktermios *old)
2255 {
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;
2263 	int best_clk = -1;
2264 	unsigned long flags;
2265 
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;
2274 
2275 	/*
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.
2282 	 */
2283 	if (!port->uartclk) {
2284 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2285 		goto done;
2286 	}
2287 
2288 	for (i = 0; i < SCI_NUM_CLKS; i++)
2289 		max_freq = max(max_freq, s->clk_rates[i]);
2290 
2291 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2292 	if (!baud)
2293 		goto done;
2294 
2295 	/*
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.
2298 	 */
2299 
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)) {
2305 			best_clk = SCI_SCK;
2306 			scr_val = SCSCR_CKE1;
2307 			sccks = SCCKS_CKS;
2308 			min_err = err;
2309 			srr = srr1;
2310 			if (!err)
2311 				goto done;
2312 		}
2313 	}
2314 
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,
2318 				   &srr1);
2319 		if (abs(err) < abs(min_err)) {
2320 			best_clk = SCI_SCIF_CLK;
2321 			scr_val = SCSCR_CKE1;
2322 			sccks = 0;
2323 			min_err = err;
2324 			dl = dl1;
2325 			srr = srr1;
2326 			if (!err)
2327 				goto done;
2328 		}
2329 	}
2330 
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,
2334 				   &srr1);
2335 		if (abs(err) < abs(min_err)) {
2336 			best_clk = SCI_BRG_INT;
2337 			scr_val = SCSCR_CKE1;
2338 			sccks = SCCKS_XIN;
2339 			min_err = err;
2340 			dl = dl1;
2341 			srr = srr1;
2342 			if (!min_err)
2343 				goto done;
2344 		}
2345 	}
2346 
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)) {
2350 		best_clk = SCI_FCK;
2351 		scr_val = 0;
2352 		min_err = err;
2353 		brr = brr1;
2354 		srr = srr1;
2355 		cks = cks1;
2356 	}
2357 
2358 done:
2359 	if (best_clk >= 0)
2360 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2361 			s->clks[best_clk], baud, min_err);
2362 
2363 	sci_port_enable(s);
2364 
2365 	/*
2366 	 * Program the optional External Baud Rate Generator (BRG) first.
2367 	 * It controls the mux to select (H)SCK or frequency divided clock.
2368 	 */
2369 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2370 		serial_port_out(port, SCDL, dl);
2371 		serial_port_out(port, SCCKS, sccks);
2372 	}
2373 
2374 	spin_lock_irqsave(&port->lock, flags);
2375 
2376 	sci_reset(port);
2377 
2378 	uart_update_timeout(port, termios->c_cflag, baud);
2379 
2380 	if (best_clk >= 0) {
2381 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2382 			switch (srr + 1) {
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;
2391 			}
2392 		smr_val |= cks;
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);
2398 
2399 		/* Wait one bit interval */
2400 		udelay((1000000 + (baud - 1)) / baud);
2401 	} else {
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);
2408 	}
2409 
2410 	sci_init_pins(port, termios->c_cflag);
2411 
2412 	port->status &= ~UPSTAT_AUTOCTS;
2413 	s->autorts = false;
2414 	reg = sci_getreg(port, SCFCR);
2415 	if (reg->size) {
2416 		unsigned short ctrl = serial_port_in(port, SCFCR);
2417 
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 */
2423 			s->autorts = true;
2424 		}
2425 
2426 		/*
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.
2430 		 */
2431 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2432 
2433 		serial_port_out(port, SCFCR, ctrl);
2434 	}
2435 	if (port->flags & UPF_HARD_FLOW) {
2436 		/* Refresh (Auto) RTS */
2437 		sci_set_mctrl(port, port->mctrl);
2438 	}
2439 
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)) {
2445 		/*
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.
2450 		 */
2451 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2452 	}
2453 
2454 	/*
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.
2463 	 */
2464 	/* byte size and parity */
2465 	switch (termios->c_cflag & CSIZE) {
2466 	case CS5:
2467 		bits = 7;
2468 		break;
2469 	case CS6:
2470 		bits = 8;
2471 		break;
2472 	case CS7:
2473 		bits = 9;
2474 		break;
2475 	default:
2476 		bits = 10;
2477 		break;
2478 	}
2479 
2480 	if (termios->c_cflag & CSTOPB)
2481 		bits++;
2482 	if (termios->c_cflag & PARENB)
2483 		bits++;
2484 
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);
2490 #endif
2491 
2492 	if ((termios->c_cflag & CREAD) != 0)
2493 		sci_start_rx(port);
2494 
2495 	spin_unlock_irqrestore(&port->lock, flags);
2496 
2497 	sci_port_disable(s);
2498 
2499 	if (UART_ENABLE_MS(port, termios->c_cflag))
2500 		sci_enable_ms(port);
2501 }
2502 
2503 static void sci_pm(struct uart_port *port, unsigned int state,
2504 		   unsigned int oldstate)
2505 {
2506 	struct sci_port *sci_port = to_sci_port(port);
2507 
2508 	switch (state) {
2509 	case UART_PM_STATE_OFF:
2510 		sci_port_disable(sci_port);
2511 		break;
2512 	default:
2513 		sci_port_enable(sci_port);
2514 		break;
2515 	}
2516 }
2517 
2518 static const char *sci_type(struct uart_port *port)
2519 {
2520 	switch (port->type) {
2521 	case PORT_IRDA:
2522 		return "irda";
2523 	case PORT_SCI:
2524 		return "sci";
2525 	case PORT_SCIF:
2526 		return "scif";
2527 	case PORT_SCIFA:
2528 		return "scifa";
2529 	case PORT_SCIFB:
2530 		return "scifb";
2531 	case PORT_HSCIF:
2532 		return "hscif";
2533 	}
2534 
2535 	return NULL;
2536 }
2537 
2538 static int sci_remap_port(struct uart_port *port)
2539 {
2540 	struct sci_port *sport = to_sci_port(port);
2541 
2542 	/*
2543 	 * Nothing to do if there's already an established membase.
2544 	 */
2545 	if (port->membase)
2546 		return 0;
2547 
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);
2552 			return -ENXIO;
2553 		}
2554 	} else {
2555 		/*
2556 		 * For the simple (and majority of) cases where we don't
2557 		 * need to do any remapping, just cast the cookie
2558 		 * directly.
2559 		 */
2560 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2561 	}
2562 
2563 	return 0;
2564 }
2565 
2566 static void sci_release_port(struct uart_port *port)
2567 {
2568 	struct sci_port *sport = to_sci_port(port);
2569 
2570 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2571 		iounmap(port->membase);
2572 		port->membase = NULL;
2573 	}
2574 
2575 	release_mem_region(port->mapbase, sport->reg_size);
2576 }
2577 
2578 static int sci_request_port(struct uart_port *port)
2579 {
2580 	struct resource *res;
2581 	struct sci_port *sport = to_sci_port(port);
2582 	int ret;
2583 
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.");
2588 		return -EBUSY;
2589 	}
2590 
2591 	ret = sci_remap_port(port);
2592 	if (unlikely(ret != 0)) {
2593 		release_resource(res);
2594 		return ret;
2595 	}
2596 
2597 	return 0;
2598 }
2599 
2600 static void sci_config_port(struct uart_port *port, int flags)
2601 {
2602 	if (flags & UART_CONFIG_TYPE) {
2603 		struct sci_port *sport = to_sci_port(port);
2604 
2605 		port->type = sport->cfg->type;
2606 		sci_request_port(port);
2607 	}
2608 }
2609 
2610 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2611 {
2612 	if (ser->baud_base < 2400)
2613 		/* No paper tape reader for Mitch.. */
2614 		return -EINVAL;
2615 
2616 	return 0;
2617 }
2618 
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,
2632 	.pm		= sci_pm,
2633 	.type		= sci_type,
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,
2641 #endif
2642 };
2643 
2644 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2645 {
2646 	const char *clk_names[] = {
2647 		[SCI_FCK] = "fck",
2648 		[SCI_SCK] = "sck",
2649 		[SCI_BRG_INT] = "brg_int",
2650 		[SCI_SCIF_CLK] = "scif_clk",
2651 	};
2652 	struct clk *clk;
2653 	unsigned int i;
2654 
2655 	if (sci_port->cfg->type == PORT_HSCIF)
2656 		clk_names[SCI_SCK] = "hsck";
2657 
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;
2662 
2663 		if (IS_ERR(clk) && i == SCI_FCK) {
2664 			/*
2665 			 * "fck" used to be called "sci_ick", and we need to
2666 			 * maintain DT backward compatibility.
2667 			 */
2668 			clk = devm_clk_get(dev, "sci_ick");
2669 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2670 				return -EPROBE_DEFER;
2671 
2672 			if (!IS_ERR(clk))
2673 				goto found;
2674 
2675 			/*
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.
2679 			 */
2680 			clk = devm_clk_get(dev, "peripheral_clk");
2681 			if (!IS_ERR(clk))
2682 				goto found;
2683 
2684 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2685 				PTR_ERR(clk));
2686 			return PTR_ERR(clk);
2687 		}
2688 
2689 found:
2690 		if (IS_ERR(clk))
2691 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2692 				PTR_ERR(clk));
2693 		else
2694 			dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
2695 				clk, clk);
2696 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2697 	}
2698 	return 0;
2699 }
2700 
2701 static const struct sci_port_params *
2702 sci_probe_regmap(const struct plat_sci_port *cfg)
2703 {
2704 	unsigned int regtype;
2705 
2706 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2707 		return &sci_port_params[cfg->regtype];
2708 
2709 	switch (cfg->type) {
2710 	case PORT_SCI:
2711 		regtype = SCIx_SCI_REGTYPE;
2712 		break;
2713 	case PORT_IRDA:
2714 		regtype = SCIx_IRDA_REGTYPE;
2715 		break;
2716 	case PORT_SCIFA:
2717 		regtype = SCIx_SCIFA_REGTYPE;
2718 		break;
2719 	case PORT_SCIFB:
2720 		regtype = SCIx_SCIFB_REGTYPE;
2721 		break;
2722 	case PORT_SCIF:
2723 		/*
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.
2728 		 */
2729 		regtype = SCIx_SH4_SCIF_REGTYPE;
2730 		break;
2731 	case PORT_HSCIF:
2732 		regtype = SCIx_HSCIF_REGTYPE;
2733 		break;
2734 	default:
2735 		pr_err("Can't probe register map for given port\n");
2736 		return NULL;
2737 	}
2738 
2739 	return &sci_port_params[regtype];
2740 }
2741 
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)
2745 {
2746 	struct uart_port *port = &sci_port->port;
2747 	const struct resource *res;
2748 	unsigned int i;
2749 	int ret;
2750 
2751 	sci_port->cfg	= p;
2752 
2753 	port->ops	= &sci_uart_ops;
2754 	port->iotype	= UPIO_MEM;
2755 	port->line	= index;
2756 
2757 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2758 	if (res == NULL)
2759 		return -ENOMEM;
2760 
2761 	port->mapbase = res->start;
2762 	sci_port->reg_size = resource_size(res);
2763 
2764 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2765 		sci_port->irqs[i] = platform_get_irq(dev, i);
2766 
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.
2771 	 */
2772 	if (sci_port->irqs[0] < 0)
2773 		return -ENXIO;
2774 
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];
2779 	}
2780 
2781 	sci_port->params = sci_probe_regmap(p);
2782 	if (unlikely(sci_port->params == NULL))
2783 		return -EINVAL;
2784 
2785 	switch (p->type) {
2786 	case PORT_SCIFB:
2787 		sci_port->rx_trigger = 48;
2788 		break;
2789 	case PORT_HSCIF:
2790 		sci_port->rx_trigger = 64;
2791 		break;
2792 	case PORT_SCIFA:
2793 		sci_port->rx_trigger = 32;
2794 		break;
2795 	case PORT_SCIF:
2796 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2797 			/* RX triggering not implemented for this IP */
2798 			sci_port->rx_trigger = 1;
2799 		else
2800 			sci_port->rx_trigger = 8;
2801 		break;
2802 	default:
2803 		sci_port->rx_trigger = 1;
2804 		break;
2805 	}
2806 
2807 	sci_port->rx_fifo_timeout = 0;
2808 	sci_port->hscif_tot = 0;
2809 
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.
2813 	 */
2814 	sci_port->sampling_rate_mask = p->sampling_rate
2815 				     ? SCI_SR(p->sampling_rate)
2816 				     : sci_port->params->sampling_rate_mask;
2817 
2818 	if (!early) {
2819 		ret = sci_init_clocks(sci_port, &dev->dev);
2820 		if (ret < 0)
2821 			return ret;
2822 
2823 		port->dev = &dev->dev;
2824 
2825 		pm_runtime_enable(&dev->dev);
2826 	}
2827 
2828 	port->type		= p->type;
2829 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2830 	port->fifosize		= sci_port->params->fifosize;
2831 
2832 	if (port->type == PORT_SCI) {
2833 		if (sci_port->reg_size >= 0x20)
2834 			port->regshift = 2;
2835 		else
2836 			port->regshift = 1;
2837 	}
2838 
2839 	/*
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.
2843 	 *
2844 	 * For the muxed case there's nothing more to do.
2845 	 */
2846 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2847 	port->irqflags		= 0;
2848 
2849 	port->serial_in		= sci_serial_in;
2850 	port->serial_out	= sci_serial_out;
2851 
2852 	return 0;
2853 }
2854 
2855 static void sci_cleanup_single(struct sci_port *port)
2856 {
2857 	pm_runtime_disable(port->port.dev);
2858 }
2859 
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)
2863 {
2864 	sci_poll_put_char(port, ch);
2865 }
2866 
2867 /*
2868  *	Print a string to the serial port trying not to disturb
2869  *	any possible real use of the port...
2870  */
2871 static void serial_console_write(struct console *co, const char *s,
2872 				 unsigned count)
2873 {
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;
2878 	int locked = 1;
2879 
2880 	local_irq_save(flags);
2881 #if defined(SUPPORT_SYSRQ)
2882 	if (port->sysrq)
2883 		locked = 0;
2884 	else
2885 #endif
2886 	if (oops_in_progress)
2887 		locked = spin_trylock(&port->lock);
2888 	else
2889 		spin_lock(&port->lock);
2890 
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);
2897 
2898 	uart_console_write(port, s, count, serial_console_putchar);
2899 
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)
2903 		cpu_relax();
2904 
2905 	/* restore the SCSCR */
2906 	serial_port_out(port, SCSCR, ctrl);
2907 
2908 	if (locked)
2909 		spin_unlock(&port->lock);
2910 	local_irq_restore(flags);
2911 }
2912 
2913 static int serial_console_setup(struct console *co, char *options)
2914 {
2915 	struct sci_port *sci_port;
2916 	struct uart_port *port;
2917 	int baud = 115200;
2918 	int bits = 8;
2919 	int parity = 'n';
2920 	int flow = 'n';
2921 	int ret;
2922 
2923 	/*
2924 	 * Refuse to handle any bogus ports.
2925 	 */
2926 	if (co->index < 0 || co->index >= SCI_NPORTS)
2927 		return -ENODEV;
2928 
2929 	sci_port = &sci_ports[co->index];
2930 	port = &sci_port->port;
2931 
2932 	/*
2933 	 * Refuse to handle uninitialized ports.
2934 	 */
2935 	if (!port->ops)
2936 		return -ENODEV;
2937 
2938 	ret = sci_remap_port(port);
2939 	if (unlikely(ret != 0))
2940 		return ret;
2941 
2942 	if (options)
2943 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2944 
2945 	return uart_set_options(port, co, baud, parity, bits, flow);
2946 }
2947 
2948 static struct console serial_console = {
2949 	.name		= "ttySC",
2950 	.device		= uart_console_device,
2951 	.write		= serial_console_write,
2952 	.setup		= serial_console_setup,
2953 	.flags		= CON_PRINTBUFFER,
2954 	.index		= -1,
2955 	.data		= &sci_uart_driver,
2956 };
2957 
2958 static struct console early_serial_console = {
2959 	.name           = "early_ttySC",
2960 	.write          = serial_console_write,
2961 	.flags          = CON_PRINTBUFFER,
2962 	.index		= -1,
2963 };
2964 
2965 static char early_serial_buf[32];
2966 
2967 static int sci_probe_earlyprintk(struct platform_device *pdev)
2968 {
2969 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
2970 
2971 	if (early_serial_console.data)
2972 		return -EEXIST;
2973 
2974 	early_serial_console.index = pdev->id;
2975 
2976 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
2977 
2978 	serial_console_setup(&early_serial_console, early_serial_buf);
2979 
2980 	if (!strstr(early_serial_buf, "keep"))
2981 		early_serial_console.flags |= CON_BOOT;
2982 
2983 	register_console(&early_serial_console);
2984 	return 0;
2985 }
2986 
2987 #define SCI_CONSOLE	(&serial_console)
2988 
2989 #else
2990 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
2991 {
2992 	return -EINVAL;
2993 }
2994 
2995 #define SCI_CONSOLE	NULL
2996 
2997 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
2998 
2999 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3000 
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",
3006 	.major		= SCI_MAJOR,
3007 	.minor		= SCI_MINOR_START,
3008 	.nr		= SCI_NPORTS,
3009 	.cons		= SCI_CONSOLE,
3010 };
3011 
3012 static int sci_remove(struct platform_device *dev)
3013 {
3014 	struct sci_port *port = platform_get_drvdata(dev);
3015 
3016 	uart_remove_one_port(&sci_uart_driver, &port->port);
3017 
3018 	sci_cleanup_single(port);
3019 
3020 	if (port->port.fifosize > 1) {
3021 		sysfs_remove_file(&dev->dev.kobj,
3022 				  &dev_attr_rx_fifo_trigger.attr);
3023 	}
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);
3028 	}
3029 
3030 	return 0;
3031 }
3032 
3033 
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)
3037 
3038 static const struct of_device_id of_sci_match[] = {
3039 	/* SoC-specific types */
3040 	{
3041 		.compatible = "renesas,scif-r7s72100",
3042 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3043 	},
3044 	/* Family-specific types */
3045 	{
3046 		.compatible = "renesas,rcar-gen1-scif",
3047 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3048 	}, {
3049 		.compatible = "renesas,rcar-gen2-scif",
3050 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3051 	}, {
3052 		.compatible = "renesas,rcar-gen3-scif",
3053 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3054 	},
3055 	/* Generic types */
3056 	{
3057 		.compatible = "renesas,scif",
3058 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3059 	}, {
3060 		.compatible = "renesas,scifa",
3061 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3062 	}, {
3063 		.compatible = "renesas,scifb",
3064 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3065 	}, {
3066 		.compatible = "renesas,hscif",
3067 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3068 	}, {
3069 		.compatible = "renesas,sci",
3070 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3071 	}, {
3072 		/* Terminator */
3073 	},
3074 };
3075 MODULE_DEVICE_TABLE(of, of_sci_match);
3076 
3077 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3078 					  unsigned int *dev_id)
3079 {
3080 	struct device_node *np = pdev->dev.of_node;
3081 	struct plat_sci_port *p;
3082 	struct sci_port *sp;
3083 	const void *data;
3084 	int id;
3085 
3086 	if (!IS_ENABLED(CONFIG_OF) || !np)
3087 		return NULL;
3088 
3089 	data = of_device_get_match_data(&pdev->dev);
3090 
3091 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3092 	if (!p)
3093 		return NULL;
3094 
3095 	/* Get the line number from the aliases node. */
3096 	id = of_alias_get_id(np, "serial");
3097 	if (id < 0) {
3098 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3099 		return NULL;
3100 	}
3101 
3102 	sp = &sci_ports[id];
3103 	*dev_id = id;
3104 
3105 	p->type = SCI_OF_TYPE(data);
3106 	p->regtype = SCI_OF_REGTYPE(data);
3107 
3108 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3109 
3110 	return p;
3111 }
3112 
3113 static int sci_probe_single(struct platform_device *dev,
3114 				      unsigned int index,
3115 				      struct plat_sci_port *p,
3116 				      struct sci_port *sciport)
3117 {
3118 	int ret;
3119 
3120 	/* Sanity check */
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");
3125 		return -EINVAL;
3126 	}
3127 
3128 	mutex_lock(&sci_uart_registration_lock);
3129 	if (!sci_uart_driver.state) {
3130 		ret = uart_register_driver(&sci_uart_driver);
3131 		if (ret) {
3132 			mutex_unlock(&sci_uart_registration_lock);
3133 			return ret;
3134 		}
3135 	}
3136 	mutex_unlock(&sci_uart_registration_lock);
3137 
3138 	ret = sci_init_single(dev, sciport, index, p, false);
3139 	if (ret)
3140 		return ret;
3141 
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);
3145 
3146 	if (sciport->has_rtscts) {
3147 		if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3148 							UART_GPIO_CTS)) ||
3149 		    !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3150 							UART_GPIO_RTS))) {
3151 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3152 			return -EINVAL;
3153 		}
3154 		sciport->port.flags |= UPF_HARD_FLOW;
3155 	}
3156 
3157 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3158 	if (ret) {
3159 		sci_cleanup_single(sciport);
3160 		return ret;
3161 	}
3162 
3163 	return 0;
3164 }
3165 
3166 static int sci_probe(struct platform_device *dev)
3167 {
3168 	struct plat_sci_port *p;
3169 	struct sci_port *sp;
3170 	unsigned int dev_id;
3171 	int ret;
3172 
3173 	/*
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.
3177 	 */
3178 	if (is_early_platform_device(dev))
3179 		return sci_probe_earlyprintk(dev);
3180 
3181 	if (dev->dev.of_node) {
3182 		p = sci_parse_dt(dev, &dev_id);
3183 		if (p == NULL)
3184 			return -EINVAL;
3185 	} else {
3186 		p = dev->dev.platform_data;
3187 		if (p == NULL) {
3188 			dev_err(&dev->dev, "no platform data supplied\n");
3189 			return -EINVAL;
3190 		}
3191 
3192 		dev_id = dev->id;
3193 	}
3194 
3195 	sp = &sci_ports[dev_id];
3196 	platform_set_drvdata(dev, sp);
3197 
3198 	ret = sci_probe_single(dev, dev_id, p, sp);
3199 	if (ret)
3200 		return ret;
3201 
3202 	if (sp->port.fifosize > 1) {
3203 		ret = sysfs_create_file(&dev->dev.kobj,
3204 				&dev_attr_rx_fifo_trigger.attr);
3205 		if (ret)
3206 			return ret;
3207 	}
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);
3212 		if (ret) {
3213 			if (sp->port.fifosize > 1) {
3214 				sysfs_remove_file(&dev->dev.kobj,
3215 					&dev_attr_rx_fifo_trigger.attr);
3216 			}
3217 			return ret;
3218 		}
3219 	}
3220 
3221 #ifdef CONFIG_SH_STANDARD_BIOS
3222 	sh_bios_gdb_detach();
3223 #endif
3224 
3225 	return 0;
3226 }
3227 
3228 static __maybe_unused int sci_suspend(struct device *dev)
3229 {
3230 	struct sci_port *sport = dev_get_drvdata(dev);
3231 
3232 	if (sport)
3233 		uart_suspend_port(&sci_uart_driver, &sport->port);
3234 
3235 	return 0;
3236 }
3237 
3238 static __maybe_unused int sci_resume(struct device *dev)
3239 {
3240 	struct sci_port *sport = dev_get_drvdata(dev);
3241 
3242 	if (sport)
3243 		uart_resume_port(&sci_uart_driver, &sport->port);
3244 
3245 	return 0;
3246 }
3247 
3248 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3249 
3250 static struct platform_driver sci_driver = {
3251 	.probe		= sci_probe,
3252 	.remove		= sci_remove,
3253 	.driver		= {
3254 		.name	= "sh-sci",
3255 		.pm	= &sci_dev_pm_ops,
3256 		.of_match_table = of_match_ptr(of_sci_match),
3257 	},
3258 };
3259 
3260 static int __init sci_init(void)
3261 {
3262 	pr_info("%s\n", banner);
3263 
3264 	return platform_driver_register(&sci_driver);
3265 }
3266 
3267 static void __exit sci_exit(void)
3268 {
3269 	platform_driver_unregister(&sci_driver);
3270 
3271 	if (sci_uart_driver.state)
3272 		uart_unregister_driver(&sci_uart_driver);
3273 }
3274 
3275 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3276 early_platform_init_buffer("earlyprintk", &sci_driver,
3277 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3278 #endif
3279 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3280 static struct plat_sci_port port_cfg __initdata;
3281 
3282 static int __init early_console_setup(struct earlycon_device *device,
3283 				      int type)
3284 {
3285 	if (!device->port.membase)
3286 		return -ENODEV;
3287 
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);
3298 
3299 	device->con->write = serial_console_write;
3300 	return 0;
3301 }
3302 static int __init sci_early_console_setup(struct earlycon_device *device,
3303 					  const char *opt)
3304 {
3305 	return early_console_setup(device, PORT_SCI);
3306 }
3307 static int __init scif_early_console_setup(struct earlycon_device *device,
3308 					  const char *opt)
3309 {
3310 	return early_console_setup(device, PORT_SCIF);
3311 }
3312 static int __init scifa_early_console_setup(struct earlycon_device *device,
3313 					  const char *opt)
3314 {
3315 	return early_console_setup(device, PORT_SCIFA);
3316 }
3317 static int __init scifb_early_console_setup(struct earlycon_device *device,
3318 					  const char *opt)
3319 {
3320 	return early_console_setup(device, PORT_SCIFB);
3321 }
3322 static int __init hscif_early_console_setup(struct earlycon_device *device,
3323 					  const char *opt)
3324 {
3325 	return early_console_setup(device, PORT_HSCIF);
3326 }
3327 
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 */
3334 
3335 module_init(sci_init);
3336 module_exit(sci_exit);
3337 
3338 MODULE_LICENSE("GPL");
3339 MODULE_ALIAS("platform:sh-sci");
3340 MODULE_AUTHOR("Paul Mundt");
3341 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3342