xref: /linux/drivers/tty/serial/sh-sci.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #undef DEBUG
19 
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/minmax.h>
35 #include <linux/module.h>
36 #include <linux/mm.h>
37 #include <linux/of.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm_runtime.h>
40 #include <linux/reset.h>
41 #include <linux/scatterlist.h>
42 #include <linux/serial.h>
43 #include <linux/serial_sci.h>
44 #include <linux/sh_dma.h>
45 #include <linux/slab.h>
46 #include <linux/string.h>
47 #include <linux/sysrq.h>
48 #include <linux/timer.h>
49 #include <linux/tty.h>
50 #include <linux/tty_flip.h>
51 
52 #ifdef CONFIG_SUPERH
53 #include <asm/sh_bios.h>
54 #include <asm/platform_early.h>
55 #endif
56 
57 #include "serial_mctrl_gpio.h"
58 #include "sh-sci.h"
59 
60 /* Offsets into the sci_port->irqs array */
61 enum {
62 	SCIx_ERI_IRQ,
63 	SCIx_RXI_IRQ,
64 	SCIx_TXI_IRQ,
65 	SCIx_BRI_IRQ,
66 	SCIx_DRI_IRQ,
67 	SCIx_TEI_IRQ,
68 	SCIx_NR_IRQS,
69 
70 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
71 };
72 
73 #define SCIx_IRQ_IS_MUXED(port)			\
74 	((port)->irqs[SCIx_ERI_IRQ] ==	\
75 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
76 	((port)->irqs[SCIx_ERI_IRQ] &&	\
77 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
78 
79 enum SCI_CLKS {
80 	SCI_FCK,		/* Functional Clock */
81 	SCI_SCK,		/* Optional External Clock */
82 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
83 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
84 	SCI_NUM_CLKS
85 };
86 
87 /* Bit x set means sampling rate x + 1 is supported */
88 #define SCI_SR(x)		BIT((x) - 1)
89 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
90 
91 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
92 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
93 				SCI_SR(19) | SCI_SR(27)
94 
95 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
96 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
97 
98 /* Iterate over all supported sampling rates, from high to low */
99 #define for_each_sr(_sr, _port)						\
100 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
101 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
102 
103 struct plat_sci_reg {
104 	u8 offset, size;
105 };
106 
107 struct sci_port_params {
108 	const struct plat_sci_reg regs[SCIx_NR_REGS];
109 	unsigned int fifosize;
110 	unsigned int overrun_reg;
111 	unsigned int overrun_mask;
112 	unsigned int sampling_rate_mask;
113 	unsigned int error_mask;
114 	unsigned int error_clear;
115 };
116 
117 struct sci_port {
118 	struct uart_port	port;
119 
120 	/* Platform configuration */
121 	const struct sci_port_params *params;
122 	const struct plat_sci_port *cfg;
123 	unsigned int		sampling_rate_mask;
124 	resource_size_t		reg_size;
125 	struct mctrl_gpios	*gpios;
126 
127 	/* Clocks */
128 	struct clk		*clks[SCI_NUM_CLKS];
129 	unsigned long		clk_rates[SCI_NUM_CLKS];
130 
131 	int			irqs[SCIx_NR_IRQS];
132 	char			*irqstr[SCIx_NR_IRQS];
133 
134 	struct dma_chan			*chan_tx;
135 	struct dma_chan			*chan_rx;
136 
137 #ifdef CONFIG_SERIAL_SH_SCI_DMA
138 	struct dma_chan			*chan_tx_saved;
139 	struct dma_chan			*chan_rx_saved;
140 	dma_cookie_t			cookie_tx;
141 	dma_cookie_t			cookie_rx[2];
142 	dma_cookie_t			active_rx;
143 	dma_addr_t			tx_dma_addr;
144 	unsigned int			tx_dma_len;
145 	struct scatterlist		sg_rx[2];
146 	void				*rx_buf[2];
147 	size_t				buf_len_rx;
148 	struct work_struct		work_tx;
149 	struct hrtimer			rx_timer;
150 	unsigned int			rx_timeout;	/* microseconds */
151 #endif
152 	unsigned int			rx_frame;
153 	int				rx_trigger;
154 	struct timer_list		rx_fifo_timer;
155 	int				rx_fifo_timeout;
156 	u16				hscif_tot;
157 
158 	bool has_rtscts;
159 	bool autorts;
160 };
161 
162 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
163 
164 static struct sci_port sci_ports[SCI_NPORTS];
165 static unsigned long sci_ports_in_use;
166 static struct uart_driver sci_uart_driver;
167 
168 static inline struct sci_port *
169 to_sci_port(struct uart_port *uart)
170 {
171 	return container_of(uart, struct sci_port, port);
172 }
173 
174 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
175 	/*
176 	 * Common SCI definitions, dependent on the port's regshift
177 	 * value.
178 	 */
179 	[SCIx_SCI_REGTYPE] = {
180 		.regs = {
181 			[SCSMR]		= { 0x00,  8 },
182 			[SCBRR]		= { 0x01,  8 },
183 			[SCSCR]		= { 0x02,  8 },
184 			[SCxTDR]	= { 0x03,  8 },
185 			[SCxSR]		= { 0x04,  8 },
186 			[SCxRDR]	= { 0x05,  8 },
187 		},
188 		.fifosize = 1,
189 		.overrun_reg = SCxSR,
190 		.overrun_mask = SCI_ORER,
191 		.sampling_rate_mask = SCI_SR(32),
192 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
193 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
194 	},
195 
196 	/*
197 	 * Common definitions for legacy IrDA ports.
198 	 */
199 	[SCIx_IRDA_REGTYPE] = {
200 		.regs = {
201 			[SCSMR]		= { 0x00,  8 },
202 			[SCBRR]		= { 0x02,  8 },
203 			[SCSCR]		= { 0x04,  8 },
204 			[SCxTDR]	= { 0x06,  8 },
205 			[SCxSR]		= { 0x08, 16 },
206 			[SCxRDR]	= { 0x0a,  8 },
207 			[SCFCR]		= { 0x0c,  8 },
208 			[SCFDR]		= { 0x0e, 16 },
209 		},
210 		.fifosize = 1,
211 		.overrun_reg = SCxSR,
212 		.overrun_mask = SCI_ORER,
213 		.sampling_rate_mask = SCI_SR(32),
214 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
215 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
216 	},
217 
218 	/*
219 	 * Common SCIFA definitions.
220 	 */
221 	[SCIx_SCIFA_REGTYPE] = {
222 		.regs = {
223 			[SCSMR]		= { 0x00, 16 },
224 			[SCBRR]		= { 0x04,  8 },
225 			[SCSCR]		= { 0x08, 16 },
226 			[SCxTDR]	= { 0x20,  8 },
227 			[SCxSR]		= { 0x14, 16 },
228 			[SCxRDR]	= { 0x24,  8 },
229 			[SCFCR]		= { 0x18, 16 },
230 			[SCFDR]		= { 0x1c, 16 },
231 			[SCPCR]		= { 0x30, 16 },
232 			[SCPDR]		= { 0x34, 16 },
233 		},
234 		.fifosize = 64,
235 		.overrun_reg = SCxSR,
236 		.overrun_mask = SCIFA_ORER,
237 		.sampling_rate_mask = SCI_SR_SCIFAB,
238 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
239 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
240 	},
241 
242 	/*
243 	 * Common SCIFB definitions.
244 	 */
245 	[SCIx_SCIFB_REGTYPE] = {
246 		.regs = {
247 			[SCSMR]		= { 0x00, 16 },
248 			[SCBRR]		= { 0x04,  8 },
249 			[SCSCR]		= { 0x08, 16 },
250 			[SCxTDR]	= { 0x40,  8 },
251 			[SCxSR]		= { 0x14, 16 },
252 			[SCxRDR]	= { 0x60,  8 },
253 			[SCFCR]		= { 0x18, 16 },
254 			[SCTFDR]	= { 0x38, 16 },
255 			[SCRFDR]	= { 0x3c, 16 },
256 			[SCPCR]		= { 0x30, 16 },
257 			[SCPDR]		= { 0x34, 16 },
258 		},
259 		.fifosize = 256,
260 		.overrun_reg = SCxSR,
261 		.overrun_mask = SCIFA_ORER,
262 		.sampling_rate_mask = SCI_SR_SCIFAB,
263 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
264 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
265 	},
266 
267 	/*
268 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
269 	 * count registers.
270 	 */
271 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
272 		.regs = {
273 			[SCSMR]		= { 0x00, 16 },
274 			[SCBRR]		= { 0x04,  8 },
275 			[SCSCR]		= { 0x08, 16 },
276 			[SCxTDR]	= { 0x0c,  8 },
277 			[SCxSR]		= { 0x10, 16 },
278 			[SCxRDR]	= { 0x14,  8 },
279 			[SCFCR]		= { 0x18, 16 },
280 			[SCFDR]		= { 0x1c, 16 },
281 			[SCSPTR]	= { 0x20, 16 },
282 			[SCLSR]		= { 0x24, 16 },
283 		},
284 		.fifosize = 16,
285 		.overrun_reg = SCLSR,
286 		.overrun_mask = SCLSR_ORER,
287 		.sampling_rate_mask = SCI_SR(32),
288 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
289 		.error_clear = SCIF_ERROR_CLEAR,
290 	},
291 
292 	/*
293 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
294 	 * It looks like a normal SCIF with FIFO data, but with a
295 	 * compressed address space. Also, the break out of interrupts
296 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
297 	 */
298 	[SCIx_RZ_SCIFA_REGTYPE] = {
299 		.regs = {
300 			[SCSMR]		= { 0x00, 16 },
301 			[SCBRR]		= { 0x02,  8 },
302 			[SCSCR]		= { 0x04, 16 },
303 			[SCxTDR]	= { 0x06,  8 },
304 			[SCxSR]		= { 0x08, 16 },
305 			[SCxRDR]	= { 0x0A,  8 },
306 			[SCFCR]		= { 0x0C, 16 },
307 			[SCFDR]		= { 0x0E, 16 },
308 			[SCSPTR]	= { 0x10, 16 },
309 			[SCLSR]		= { 0x12, 16 },
310 			[SEMR]		= { 0x14, 8 },
311 		},
312 		.fifosize = 16,
313 		.overrun_reg = SCLSR,
314 		.overrun_mask = SCLSR_ORER,
315 		.sampling_rate_mask = SCI_SR(32),
316 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
317 		.error_clear = SCIF_ERROR_CLEAR,
318 	},
319 
320 	/*
321 	 * Common SH-3 SCIF definitions.
322 	 */
323 	[SCIx_SH3_SCIF_REGTYPE] = {
324 		.regs = {
325 			[SCSMR]		= { 0x00,  8 },
326 			[SCBRR]		= { 0x02,  8 },
327 			[SCSCR]		= { 0x04,  8 },
328 			[SCxTDR]	= { 0x06,  8 },
329 			[SCxSR]		= { 0x08, 16 },
330 			[SCxRDR]	= { 0x0a,  8 },
331 			[SCFCR]		= { 0x0c,  8 },
332 			[SCFDR]		= { 0x0e, 16 },
333 		},
334 		.fifosize = 16,
335 		.overrun_reg = SCLSR,
336 		.overrun_mask = SCLSR_ORER,
337 		.sampling_rate_mask = SCI_SR(32),
338 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
339 		.error_clear = SCIF_ERROR_CLEAR,
340 	},
341 
342 	/*
343 	 * Common SH-4(A) SCIF(B) definitions.
344 	 */
345 	[SCIx_SH4_SCIF_REGTYPE] = {
346 		.regs = {
347 			[SCSMR]		= { 0x00, 16 },
348 			[SCBRR]		= { 0x04,  8 },
349 			[SCSCR]		= { 0x08, 16 },
350 			[SCxTDR]	= { 0x0c,  8 },
351 			[SCxSR]		= { 0x10, 16 },
352 			[SCxRDR]	= { 0x14,  8 },
353 			[SCFCR]		= { 0x18, 16 },
354 			[SCFDR]		= { 0x1c, 16 },
355 			[SCSPTR]	= { 0x20, 16 },
356 			[SCLSR]		= { 0x24, 16 },
357 		},
358 		.fifosize = 16,
359 		.overrun_reg = SCLSR,
360 		.overrun_mask = SCLSR_ORER,
361 		.sampling_rate_mask = SCI_SR(32),
362 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
363 		.error_clear = SCIF_ERROR_CLEAR,
364 	},
365 
366 	/*
367 	 * Common SCIF definitions for ports with a Baud Rate Generator for
368 	 * External Clock (BRG).
369 	 */
370 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
371 		.regs = {
372 			[SCSMR]		= { 0x00, 16 },
373 			[SCBRR]		= { 0x04,  8 },
374 			[SCSCR]		= { 0x08, 16 },
375 			[SCxTDR]	= { 0x0c,  8 },
376 			[SCxSR]		= { 0x10, 16 },
377 			[SCxRDR]	= { 0x14,  8 },
378 			[SCFCR]		= { 0x18, 16 },
379 			[SCFDR]		= { 0x1c, 16 },
380 			[SCSPTR]	= { 0x20, 16 },
381 			[SCLSR]		= { 0x24, 16 },
382 			[SCDL]		= { 0x30, 16 },
383 			[SCCKS]		= { 0x34, 16 },
384 		},
385 		.fifosize = 16,
386 		.overrun_reg = SCLSR,
387 		.overrun_mask = SCLSR_ORER,
388 		.sampling_rate_mask = SCI_SR(32),
389 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
390 		.error_clear = SCIF_ERROR_CLEAR,
391 	},
392 
393 	/*
394 	 * Common HSCIF definitions.
395 	 */
396 	[SCIx_HSCIF_REGTYPE] = {
397 		.regs = {
398 			[SCSMR]		= { 0x00, 16 },
399 			[SCBRR]		= { 0x04,  8 },
400 			[SCSCR]		= { 0x08, 16 },
401 			[SCxTDR]	= { 0x0c,  8 },
402 			[SCxSR]		= { 0x10, 16 },
403 			[SCxRDR]	= { 0x14,  8 },
404 			[SCFCR]		= { 0x18, 16 },
405 			[SCFDR]		= { 0x1c, 16 },
406 			[SCSPTR]	= { 0x20, 16 },
407 			[SCLSR]		= { 0x24, 16 },
408 			[HSSRR]		= { 0x40, 16 },
409 			[SCDL]		= { 0x30, 16 },
410 			[SCCKS]		= { 0x34, 16 },
411 			[HSRTRGR]	= { 0x54, 16 },
412 			[HSTTRGR]	= { 0x58, 16 },
413 		},
414 		.fifosize = 128,
415 		.overrun_reg = SCLSR,
416 		.overrun_mask = SCLSR_ORER,
417 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
418 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
419 		.error_clear = SCIF_ERROR_CLEAR,
420 	},
421 
422 	/*
423 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
424 	 * register.
425 	 */
426 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
427 		.regs = {
428 			[SCSMR]		= { 0x00, 16 },
429 			[SCBRR]		= { 0x04,  8 },
430 			[SCSCR]		= { 0x08, 16 },
431 			[SCxTDR]	= { 0x0c,  8 },
432 			[SCxSR]		= { 0x10, 16 },
433 			[SCxRDR]	= { 0x14,  8 },
434 			[SCFCR]		= { 0x18, 16 },
435 			[SCFDR]		= { 0x1c, 16 },
436 			[SCLSR]		= { 0x24, 16 },
437 		},
438 		.fifosize = 16,
439 		.overrun_reg = SCLSR,
440 		.overrun_mask = SCLSR_ORER,
441 		.sampling_rate_mask = SCI_SR(32),
442 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
443 		.error_clear = SCIF_ERROR_CLEAR,
444 	},
445 
446 	/*
447 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
448 	 * count registers.
449 	 */
450 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
451 		.regs = {
452 			[SCSMR]		= { 0x00, 16 },
453 			[SCBRR]		= { 0x04,  8 },
454 			[SCSCR]		= { 0x08, 16 },
455 			[SCxTDR]	= { 0x0c,  8 },
456 			[SCxSR]		= { 0x10, 16 },
457 			[SCxRDR]	= { 0x14,  8 },
458 			[SCFCR]		= { 0x18, 16 },
459 			[SCFDR]		= { 0x1c, 16 },
460 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
461 			[SCRFDR]	= { 0x20, 16 },
462 			[SCSPTR]	= { 0x24, 16 },
463 			[SCLSR]		= { 0x28, 16 },
464 		},
465 		.fifosize = 16,
466 		.overrun_reg = SCLSR,
467 		.overrun_mask = SCLSR_ORER,
468 		.sampling_rate_mask = SCI_SR(32),
469 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
470 		.error_clear = SCIF_ERROR_CLEAR,
471 	},
472 
473 	/*
474 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
475 	 * registers.
476 	 */
477 	[SCIx_SH7705_SCIF_REGTYPE] = {
478 		.regs = {
479 			[SCSMR]		= { 0x00, 16 },
480 			[SCBRR]		= { 0x04,  8 },
481 			[SCSCR]		= { 0x08, 16 },
482 			[SCxTDR]	= { 0x20,  8 },
483 			[SCxSR]		= { 0x14, 16 },
484 			[SCxRDR]	= { 0x24,  8 },
485 			[SCFCR]		= { 0x18, 16 },
486 			[SCFDR]		= { 0x1c, 16 },
487 		},
488 		.fifosize = 64,
489 		.overrun_reg = SCxSR,
490 		.overrun_mask = SCIFA_ORER,
491 		.sampling_rate_mask = SCI_SR(16),
492 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
493 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
494 	},
495 };
496 
497 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
498 
499 /*
500  * The "offset" here is rather misleading, in that it refers to an enum
501  * value relative to the port mapping rather than the fixed offset
502  * itself, which needs to be manually retrieved from the platform's
503  * register map for the given port.
504  */
505 static unsigned int sci_serial_in(struct uart_port *p, int offset)
506 {
507 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
508 
509 	if (reg->size == 8)
510 		return ioread8(p->membase + (reg->offset << p->regshift));
511 	else if (reg->size == 16)
512 		return ioread16(p->membase + (reg->offset << p->regshift));
513 	else
514 		WARN(1, "Invalid register access\n");
515 
516 	return 0;
517 }
518 
519 static void sci_serial_out(struct uart_port *p, int offset, int value)
520 {
521 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
522 
523 	if (reg->size == 8)
524 		iowrite8(value, p->membase + (reg->offset << p->regshift));
525 	else if (reg->size == 16)
526 		iowrite16(value, p->membase + (reg->offset << p->regshift));
527 	else
528 		WARN(1, "Invalid register access\n");
529 }
530 
531 static void sci_port_enable(struct sci_port *sci_port)
532 {
533 	unsigned int i;
534 
535 	if (!sci_port->port.dev)
536 		return;
537 
538 	pm_runtime_get_sync(sci_port->port.dev);
539 
540 	for (i = 0; i < SCI_NUM_CLKS; i++) {
541 		clk_prepare_enable(sci_port->clks[i]);
542 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
543 	}
544 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
545 }
546 
547 static void sci_port_disable(struct sci_port *sci_port)
548 {
549 	unsigned int i;
550 
551 	if (!sci_port->port.dev)
552 		return;
553 
554 	for (i = SCI_NUM_CLKS; i-- > 0; )
555 		clk_disable_unprepare(sci_port->clks[i]);
556 
557 	pm_runtime_put_sync(sci_port->port.dev);
558 }
559 
560 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
561 {
562 	/*
563 	 * Not all ports (such as SCIFA) will support REIE. Rather than
564 	 * special-casing the port type, we check the port initialization
565 	 * IRQ enable mask to see whether the IRQ is desired at all. If
566 	 * it's unset, it's logically inferred that there's no point in
567 	 * testing for it.
568 	 */
569 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
570 }
571 
572 static void sci_start_tx(struct uart_port *port)
573 {
574 	struct sci_port *s = to_sci_port(port);
575 	unsigned short ctrl;
576 
577 #ifdef CONFIG_SERIAL_SH_SCI_DMA
578 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
579 		u16 new, scr = sci_serial_in(port, SCSCR);
580 		if (s->chan_tx)
581 			new = scr | SCSCR_TDRQE;
582 		else
583 			new = scr & ~SCSCR_TDRQE;
584 		if (new != scr)
585 			sci_serial_out(port, SCSCR, new);
586 	}
587 
588 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
589 	    dma_submit_error(s->cookie_tx)) {
590 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
591 			/* Switch irq from SCIF to DMA */
592 			disable_irq_nosync(s->irqs[SCIx_TXI_IRQ]);
593 
594 		s->cookie_tx = 0;
595 		schedule_work(&s->work_tx);
596 	}
597 #endif
598 
599 	if (!s->chan_tx || s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE ||
600 	    port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
601 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
602 		ctrl = sci_serial_in(port, SCSCR);
603 
604 		/*
605 		 * For SCI, TE (transmit enable) must be set after setting TIE
606 		 * (transmit interrupt enable) or in the same instruction to start
607 		 * the transmit process.
608 		 */
609 		if (port->type == PORT_SCI)
610 			ctrl |= SCSCR_TE;
611 
612 		sci_serial_out(port, SCSCR, ctrl | SCSCR_TIE);
613 	}
614 }
615 
616 static void sci_stop_tx(struct uart_port *port)
617 {
618 	unsigned short ctrl;
619 
620 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
621 	ctrl = sci_serial_in(port, SCSCR);
622 
623 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
624 		ctrl &= ~SCSCR_TDRQE;
625 
626 	ctrl &= ~SCSCR_TIE;
627 
628 	sci_serial_out(port, SCSCR, ctrl);
629 
630 #ifdef CONFIG_SERIAL_SH_SCI_DMA
631 	if (to_sci_port(port)->chan_tx &&
632 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
633 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
634 		to_sci_port(port)->cookie_tx = -EINVAL;
635 	}
636 #endif
637 }
638 
639 static void sci_start_rx(struct uart_port *port)
640 {
641 	unsigned short ctrl;
642 
643 	ctrl = sci_serial_in(port, SCSCR) | port_rx_irq_mask(port);
644 
645 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
646 		ctrl &= ~SCSCR_RDRQE;
647 
648 	sci_serial_out(port, SCSCR, ctrl);
649 }
650 
651 static void sci_stop_rx(struct uart_port *port)
652 {
653 	unsigned short ctrl;
654 
655 	ctrl = sci_serial_in(port, SCSCR);
656 
657 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
658 		ctrl &= ~SCSCR_RDRQE;
659 
660 	ctrl &= ~port_rx_irq_mask(port);
661 
662 	sci_serial_out(port, SCSCR, ctrl);
663 }
664 
665 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
666 {
667 	if (port->type == PORT_SCI) {
668 		/* Just store the mask */
669 		sci_serial_out(port, SCxSR, mask);
670 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
671 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
672 		/* Only clear the status bits we want to clear */
673 		sci_serial_out(port, SCxSR, sci_serial_in(port, SCxSR) & mask);
674 	} else {
675 		/* Store the mask, clear parity/framing errors */
676 		sci_serial_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
677 	}
678 }
679 
680 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
681     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
682 
683 #ifdef CONFIG_CONSOLE_POLL
684 static int sci_poll_get_char(struct uart_port *port)
685 {
686 	unsigned short status;
687 	int c;
688 
689 	do {
690 		status = sci_serial_in(port, SCxSR);
691 		if (status & SCxSR_ERRORS(port)) {
692 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
693 			continue;
694 		}
695 		break;
696 	} while (1);
697 
698 	if (!(status & SCxSR_RDxF(port)))
699 		return NO_POLL_CHAR;
700 
701 	c = sci_serial_in(port, SCxRDR);
702 
703 	/* Dummy read */
704 	sci_serial_in(port, SCxSR);
705 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
706 
707 	return c;
708 }
709 #endif
710 
711 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
712 {
713 	unsigned short status;
714 
715 	do {
716 		status = sci_serial_in(port, SCxSR);
717 	} while (!(status & SCxSR_TDxE(port)));
718 
719 	sci_serial_out(port, SCxTDR, c);
720 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
721 }
722 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
723 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
724 
725 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
726 {
727 	struct sci_port *s = to_sci_port(port);
728 
729 	/*
730 	 * Use port-specific handler if provided.
731 	 */
732 	if (s->cfg->ops && s->cfg->ops->init_pins) {
733 		s->cfg->ops->init_pins(port, cflag);
734 		return;
735 	}
736 
737 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
738 		u16 data = sci_serial_in(port, SCPDR);
739 		u16 ctrl = sci_serial_in(port, SCPCR);
740 
741 		/* Enable RXD and TXD pin functions */
742 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
743 		if (to_sci_port(port)->has_rtscts) {
744 			/* RTS# is output, active low, unless autorts */
745 			if (!(port->mctrl & TIOCM_RTS)) {
746 				ctrl |= SCPCR_RTSC;
747 				data |= SCPDR_RTSD;
748 			} else if (!s->autorts) {
749 				ctrl |= SCPCR_RTSC;
750 				data &= ~SCPDR_RTSD;
751 			} else {
752 				/* Enable RTS# pin function */
753 				ctrl &= ~SCPCR_RTSC;
754 			}
755 			/* Enable CTS# pin function */
756 			ctrl &= ~SCPCR_CTSC;
757 		}
758 		sci_serial_out(port, SCPDR, data);
759 		sci_serial_out(port, SCPCR, ctrl);
760 	} else if (sci_getreg(port, SCSPTR)->size) {
761 		u16 status = sci_serial_in(port, SCSPTR);
762 
763 		/* RTS# is always output; and active low, unless autorts */
764 		status |= SCSPTR_RTSIO;
765 		if (!(port->mctrl & TIOCM_RTS))
766 			status |= SCSPTR_RTSDT;
767 		else if (!s->autorts)
768 			status &= ~SCSPTR_RTSDT;
769 		/* CTS# and SCK are inputs */
770 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
771 		sci_serial_out(port, SCSPTR, status);
772 	}
773 }
774 
775 static int sci_txfill(struct uart_port *port)
776 {
777 	struct sci_port *s = to_sci_port(port);
778 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
779 	const struct plat_sci_reg *reg;
780 
781 	reg = sci_getreg(port, SCTFDR);
782 	if (reg->size)
783 		return sci_serial_in(port, SCTFDR) & fifo_mask;
784 
785 	reg = sci_getreg(port, SCFDR);
786 	if (reg->size)
787 		return sci_serial_in(port, SCFDR) >> 8;
788 
789 	return !(sci_serial_in(port, SCxSR) & SCI_TDRE);
790 }
791 
792 static int sci_txroom(struct uart_port *port)
793 {
794 	return port->fifosize - sci_txfill(port);
795 }
796 
797 static int sci_rxfill(struct uart_port *port)
798 {
799 	struct sci_port *s = to_sci_port(port);
800 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
801 	const struct plat_sci_reg *reg;
802 
803 	reg = sci_getreg(port, SCRFDR);
804 	if (reg->size)
805 		return sci_serial_in(port, SCRFDR) & fifo_mask;
806 
807 	reg = sci_getreg(port, SCFDR);
808 	if (reg->size)
809 		return sci_serial_in(port, SCFDR) & fifo_mask;
810 
811 	return (sci_serial_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
812 }
813 
814 /* ********************************************************************** *
815  *                   the interrupt related routines                       *
816  * ********************************************************************** */
817 
818 static void sci_transmit_chars(struct uart_port *port)
819 {
820 	struct circ_buf *xmit = &port->state->xmit;
821 	unsigned int stopped = uart_tx_stopped(port);
822 	unsigned short status;
823 	unsigned short ctrl;
824 	int count;
825 
826 	status = sci_serial_in(port, SCxSR);
827 	if (!(status & SCxSR_TDxE(port))) {
828 		ctrl = sci_serial_in(port, SCSCR);
829 		if (uart_circ_empty(xmit))
830 			ctrl &= ~SCSCR_TIE;
831 		else
832 			ctrl |= SCSCR_TIE;
833 		sci_serial_out(port, SCSCR, ctrl);
834 		return;
835 	}
836 
837 	count = sci_txroom(port);
838 
839 	do {
840 		unsigned char c;
841 
842 		if (port->x_char) {
843 			c = port->x_char;
844 			port->x_char = 0;
845 		} else if (!uart_circ_empty(xmit) && !stopped) {
846 			c = xmit->buf[xmit->tail];
847 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
848 		} else if (port->type == PORT_SCI && uart_circ_empty(xmit)) {
849 			ctrl = sci_serial_in(port, SCSCR);
850 			ctrl &= ~SCSCR_TE;
851 			sci_serial_out(port, SCSCR, ctrl);
852 			return;
853 		} else {
854 			break;
855 		}
856 
857 		sci_serial_out(port, SCxTDR, c);
858 
859 		port->icount.tx++;
860 	} while (--count > 0);
861 
862 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
863 
864 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
865 		uart_write_wakeup(port);
866 	if (uart_circ_empty(xmit)) {
867 		if (port->type == PORT_SCI) {
868 			ctrl = sci_serial_in(port, SCSCR);
869 			ctrl &= ~SCSCR_TIE;
870 			ctrl |= SCSCR_TEIE;
871 			sci_serial_out(port, SCSCR, ctrl);
872 		}
873 
874 		sci_stop_tx(port);
875 	}
876 }
877 
878 static void sci_receive_chars(struct uart_port *port)
879 {
880 	struct tty_port *tport = &port->state->port;
881 	int i, count, copied = 0;
882 	unsigned short status;
883 	unsigned char flag;
884 
885 	status = sci_serial_in(port, SCxSR);
886 	if (!(status & SCxSR_RDxF(port)))
887 		return;
888 
889 	while (1) {
890 		/* Don't copy more bytes than there is room for in the buffer */
891 		count = tty_buffer_request_room(tport, sci_rxfill(port));
892 
893 		/* If for any reason we can't copy more data, we're done! */
894 		if (count == 0)
895 			break;
896 
897 		if (port->type == PORT_SCI) {
898 			char c = sci_serial_in(port, SCxRDR);
899 			if (uart_handle_sysrq_char(port, c))
900 				count = 0;
901 			else
902 				tty_insert_flip_char(tport, c, TTY_NORMAL);
903 		} else {
904 			for (i = 0; i < count; i++) {
905 				char c;
906 
907 				if (port->type == PORT_SCIF ||
908 				    port->type == PORT_HSCIF) {
909 					status = sci_serial_in(port, SCxSR);
910 					c = sci_serial_in(port, SCxRDR);
911 				} else {
912 					c = sci_serial_in(port, SCxRDR);
913 					status = sci_serial_in(port, SCxSR);
914 				}
915 				if (uart_handle_sysrq_char(port, c)) {
916 					count--; i--;
917 					continue;
918 				}
919 
920 				/* Store data and status */
921 				if (status & SCxSR_FER(port)) {
922 					flag = TTY_FRAME;
923 					port->icount.frame++;
924 				} else if (status & SCxSR_PER(port)) {
925 					flag = TTY_PARITY;
926 					port->icount.parity++;
927 				} else
928 					flag = TTY_NORMAL;
929 
930 				tty_insert_flip_char(tport, c, flag);
931 			}
932 		}
933 
934 		sci_serial_in(port, SCxSR); /* dummy read */
935 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
936 
937 		copied += count;
938 		port->icount.rx += count;
939 	}
940 
941 	if (copied) {
942 		/* Tell the rest of the system the news. New characters! */
943 		tty_flip_buffer_push(tport);
944 	} else {
945 		/* TTY buffers full; read from RX reg to prevent lockup */
946 		sci_serial_in(port, SCxRDR);
947 		sci_serial_in(port, SCxSR); /* dummy read */
948 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
949 	}
950 }
951 
952 static int sci_handle_errors(struct uart_port *port)
953 {
954 	int copied = 0;
955 	unsigned short status = sci_serial_in(port, SCxSR);
956 	struct tty_port *tport = &port->state->port;
957 	struct sci_port *s = to_sci_port(port);
958 
959 	/* Handle overruns */
960 	if (status & s->params->overrun_mask) {
961 		port->icount.overrun++;
962 
963 		/* overrun error */
964 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
965 			copied++;
966 	}
967 
968 	if (status & SCxSR_FER(port)) {
969 		/* frame error */
970 		port->icount.frame++;
971 
972 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
973 			copied++;
974 	}
975 
976 	if (status & SCxSR_PER(port)) {
977 		/* parity error */
978 		port->icount.parity++;
979 
980 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
981 			copied++;
982 	}
983 
984 	if (copied)
985 		tty_flip_buffer_push(tport);
986 
987 	return copied;
988 }
989 
990 static int sci_handle_fifo_overrun(struct uart_port *port)
991 {
992 	struct tty_port *tport = &port->state->port;
993 	struct sci_port *s = to_sci_port(port);
994 	const struct plat_sci_reg *reg;
995 	int copied = 0;
996 	u16 status;
997 
998 	reg = sci_getreg(port, s->params->overrun_reg);
999 	if (!reg->size)
1000 		return 0;
1001 
1002 	status = sci_serial_in(port, s->params->overrun_reg);
1003 	if (status & s->params->overrun_mask) {
1004 		status &= ~s->params->overrun_mask;
1005 		sci_serial_out(port, s->params->overrun_reg, status);
1006 
1007 		port->icount.overrun++;
1008 
1009 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1010 		tty_flip_buffer_push(tport);
1011 		copied++;
1012 	}
1013 
1014 	return copied;
1015 }
1016 
1017 static int sci_handle_breaks(struct uart_port *port)
1018 {
1019 	int copied = 0;
1020 	unsigned short status = sci_serial_in(port, SCxSR);
1021 	struct tty_port *tport = &port->state->port;
1022 
1023 	if (uart_handle_break(port))
1024 		return 0;
1025 
1026 	if (status & SCxSR_BRK(port)) {
1027 		port->icount.brk++;
1028 
1029 		/* Notify of BREAK */
1030 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1031 			copied++;
1032 	}
1033 
1034 	if (copied)
1035 		tty_flip_buffer_push(tport);
1036 
1037 	copied += sci_handle_fifo_overrun(port);
1038 
1039 	return copied;
1040 }
1041 
1042 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1043 {
1044 	unsigned int bits;
1045 
1046 	if (rx_trig >= port->fifosize)
1047 		rx_trig = port->fifosize - 1;
1048 	if (rx_trig < 1)
1049 		rx_trig = 1;
1050 
1051 	/* HSCIF can be set to an arbitrary level. */
1052 	if (sci_getreg(port, HSRTRGR)->size) {
1053 		sci_serial_out(port, HSRTRGR, rx_trig);
1054 		return rx_trig;
1055 	}
1056 
1057 	switch (port->type) {
1058 	case PORT_SCIF:
1059 		if (rx_trig < 4) {
1060 			bits = 0;
1061 			rx_trig = 1;
1062 		} else if (rx_trig < 8) {
1063 			bits = SCFCR_RTRG0;
1064 			rx_trig = 4;
1065 		} else if (rx_trig < 14) {
1066 			bits = SCFCR_RTRG1;
1067 			rx_trig = 8;
1068 		} else {
1069 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1070 			rx_trig = 14;
1071 		}
1072 		break;
1073 	case PORT_SCIFA:
1074 	case PORT_SCIFB:
1075 		if (rx_trig < 16) {
1076 			bits = 0;
1077 			rx_trig = 1;
1078 		} else if (rx_trig < 32) {
1079 			bits = SCFCR_RTRG0;
1080 			rx_trig = 16;
1081 		} else if (rx_trig < 48) {
1082 			bits = SCFCR_RTRG1;
1083 			rx_trig = 32;
1084 		} else {
1085 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1086 			rx_trig = 48;
1087 		}
1088 		break;
1089 	default:
1090 		WARN(1, "unknown FIFO configuration");
1091 		return 1;
1092 	}
1093 
1094 	sci_serial_out(port, SCFCR,
1095 		       (sci_serial_in(port, SCFCR) &
1096 			~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1097 
1098 	return rx_trig;
1099 }
1100 
1101 static int scif_rtrg_enabled(struct uart_port *port)
1102 {
1103 	if (sci_getreg(port, HSRTRGR)->size)
1104 		return sci_serial_in(port, HSRTRGR) != 0;
1105 	else
1106 		return (sci_serial_in(port, SCFCR) &
1107 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1108 }
1109 
1110 static void rx_fifo_timer_fn(struct timer_list *t)
1111 {
1112 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1113 	struct uart_port *port = &s->port;
1114 
1115 	dev_dbg(port->dev, "Rx timed out\n");
1116 	scif_set_rtrg(port, 1);
1117 }
1118 
1119 static ssize_t rx_fifo_trigger_show(struct device *dev,
1120 				    struct device_attribute *attr, char *buf)
1121 {
1122 	struct uart_port *port = dev_get_drvdata(dev);
1123 	struct sci_port *sci = to_sci_port(port);
1124 
1125 	return sprintf(buf, "%d\n", sci->rx_trigger);
1126 }
1127 
1128 static ssize_t rx_fifo_trigger_store(struct device *dev,
1129 				     struct device_attribute *attr,
1130 				     const char *buf, size_t count)
1131 {
1132 	struct uart_port *port = dev_get_drvdata(dev);
1133 	struct sci_port *sci = to_sci_port(port);
1134 	int ret;
1135 	long r;
1136 
1137 	ret = kstrtol(buf, 0, &r);
1138 	if (ret)
1139 		return ret;
1140 
1141 	sci->rx_trigger = scif_set_rtrg(port, r);
1142 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1143 		scif_set_rtrg(port, 1);
1144 
1145 	return count;
1146 }
1147 
1148 static DEVICE_ATTR_RW(rx_fifo_trigger);
1149 
1150 static ssize_t rx_fifo_timeout_show(struct device *dev,
1151 			       struct device_attribute *attr,
1152 			       char *buf)
1153 {
1154 	struct uart_port *port = dev_get_drvdata(dev);
1155 	struct sci_port *sci = to_sci_port(port);
1156 	int v;
1157 
1158 	if (port->type == PORT_HSCIF)
1159 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1160 	else
1161 		v = sci->rx_fifo_timeout;
1162 
1163 	return sprintf(buf, "%d\n", v);
1164 }
1165 
1166 static ssize_t rx_fifo_timeout_store(struct device *dev,
1167 				struct device_attribute *attr,
1168 				const char *buf,
1169 				size_t count)
1170 {
1171 	struct uart_port *port = dev_get_drvdata(dev);
1172 	struct sci_port *sci = to_sci_port(port);
1173 	int ret;
1174 	long r;
1175 
1176 	ret = kstrtol(buf, 0, &r);
1177 	if (ret)
1178 		return ret;
1179 
1180 	if (port->type == PORT_HSCIF) {
1181 		if (r < 0 || r > 3)
1182 			return -EINVAL;
1183 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1184 	} else {
1185 		sci->rx_fifo_timeout = r;
1186 		scif_set_rtrg(port, 1);
1187 		if (r > 0)
1188 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1189 	}
1190 
1191 	return count;
1192 }
1193 
1194 static DEVICE_ATTR_RW(rx_fifo_timeout);
1195 
1196 
1197 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1198 static void sci_dma_tx_complete(void *arg)
1199 {
1200 	struct sci_port *s = arg;
1201 	struct uart_port *port = &s->port;
1202 	struct circ_buf *xmit = &port->state->xmit;
1203 	unsigned long flags;
1204 
1205 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1206 
1207 	uart_port_lock_irqsave(port, &flags);
1208 
1209 	uart_xmit_advance(port, s->tx_dma_len);
1210 
1211 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1212 		uart_write_wakeup(port);
1213 
1214 	if (!uart_circ_empty(xmit)) {
1215 		s->cookie_tx = 0;
1216 		schedule_work(&s->work_tx);
1217 	} else {
1218 		s->cookie_tx = -EINVAL;
1219 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1220 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1221 			u16 ctrl = sci_serial_in(port, SCSCR);
1222 			sci_serial_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1223 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1224 				/* Switch irq from DMA to SCIF */
1225 				dmaengine_pause(s->chan_tx_saved);
1226 				enable_irq(s->irqs[SCIx_TXI_IRQ]);
1227 			}
1228 		}
1229 	}
1230 
1231 	uart_port_unlock_irqrestore(port, flags);
1232 }
1233 
1234 /* Locking: called with port lock held */
1235 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1236 {
1237 	struct uart_port *port = &s->port;
1238 	struct tty_port *tport = &port->state->port;
1239 	int copied;
1240 
1241 	copied = tty_insert_flip_string(tport, buf, count);
1242 	if (copied < count)
1243 		port->icount.buf_overrun++;
1244 
1245 	port->icount.rx += copied;
1246 
1247 	return copied;
1248 }
1249 
1250 static int sci_dma_rx_find_active(struct sci_port *s)
1251 {
1252 	unsigned int i;
1253 
1254 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1255 		if (s->active_rx == s->cookie_rx[i])
1256 			return i;
1257 
1258 	return -1;
1259 }
1260 
1261 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1262 {
1263 	unsigned int i;
1264 
1265 	s->chan_rx = NULL;
1266 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1267 		s->cookie_rx[i] = -EINVAL;
1268 	s->active_rx = 0;
1269 }
1270 
1271 static void sci_dma_rx_release(struct sci_port *s)
1272 {
1273 	struct dma_chan *chan = s->chan_rx_saved;
1274 
1275 	s->chan_rx_saved = NULL;
1276 	sci_dma_rx_chan_invalidate(s);
1277 	dmaengine_terminate_sync(chan);
1278 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1279 			  sg_dma_address(&s->sg_rx[0]));
1280 	dma_release_channel(chan);
1281 }
1282 
1283 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1284 {
1285 	long sec = usec / 1000000;
1286 	long nsec = (usec % 1000000) * 1000;
1287 	ktime_t t = ktime_set(sec, nsec);
1288 
1289 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1290 }
1291 
1292 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1293 {
1294 	struct uart_port *port = &s->port;
1295 	u16 scr;
1296 
1297 	/* Direct new serial port interrupts back to CPU */
1298 	scr = sci_serial_in(port, SCSCR);
1299 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1300 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1301 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1302 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1303 			scif_set_rtrg(port, s->rx_trigger);
1304 		else
1305 			scr &= ~SCSCR_RDRQE;
1306 	}
1307 	sci_serial_out(port, SCSCR, scr | SCSCR_RIE);
1308 }
1309 
1310 static void sci_dma_rx_complete(void *arg)
1311 {
1312 	struct sci_port *s = arg;
1313 	struct dma_chan *chan = s->chan_rx;
1314 	struct uart_port *port = &s->port;
1315 	struct dma_async_tx_descriptor *desc;
1316 	unsigned long flags;
1317 	int active, count = 0;
1318 
1319 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1320 		s->active_rx);
1321 
1322 	uart_port_lock_irqsave(port, &flags);
1323 
1324 	active = sci_dma_rx_find_active(s);
1325 	if (active >= 0)
1326 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1327 
1328 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1329 
1330 	if (count)
1331 		tty_flip_buffer_push(&port->state->port);
1332 
1333 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1334 				       DMA_DEV_TO_MEM,
1335 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1336 	if (!desc)
1337 		goto fail;
1338 
1339 	desc->callback = sci_dma_rx_complete;
1340 	desc->callback_param = s;
1341 	s->cookie_rx[active] = dmaengine_submit(desc);
1342 	if (dma_submit_error(s->cookie_rx[active]))
1343 		goto fail;
1344 
1345 	s->active_rx = s->cookie_rx[!active];
1346 
1347 	dma_async_issue_pending(chan);
1348 
1349 	uart_port_unlock_irqrestore(port, flags);
1350 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1351 		__func__, s->cookie_rx[active], active, s->active_rx);
1352 	return;
1353 
1354 fail:
1355 	uart_port_unlock_irqrestore(port, flags);
1356 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1357 	/* Switch to PIO */
1358 	uart_port_lock_irqsave(port, &flags);
1359 	dmaengine_terminate_async(chan);
1360 	sci_dma_rx_chan_invalidate(s);
1361 	sci_dma_rx_reenable_irq(s);
1362 	uart_port_unlock_irqrestore(port, flags);
1363 }
1364 
1365 static void sci_dma_tx_release(struct sci_port *s)
1366 {
1367 	struct dma_chan *chan = s->chan_tx_saved;
1368 
1369 	cancel_work_sync(&s->work_tx);
1370 	s->chan_tx_saved = s->chan_tx = NULL;
1371 	s->cookie_tx = -EINVAL;
1372 	dmaengine_terminate_sync(chan);
1373 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1374 			 DMA_TO_DEVICE);
1375 	dma_release_channel(chan);
1376 }
1377 
1378 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1379 {
1380 	struct dma_chan *chan = s->chan_rx;
1381 	struct uart_port *port = &s->port;
1382 	unsigned long flags;
1383 	int i;
1384 
1385 	for (i = 0; i < 2; i++) {
1386 		struct scatterlist *sg = &s->sg_rx[i];
1387 		struct dma_async_tx_descriptor *desc;
1388 
1389 		desc = dmaengine_prep_slave_sg(chan,
1390 			sg, 1, DMA_DEV_TO_MEM,
1391 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1392 		if (!desc)
1393 			goto fail;
1394 
1395 		desc->callback = sci_dma_rx_complete;
1396 		desc->callback_param = s;
1397 		s->cookie_rx[i] = dmaengine_submit(desc);
1398 		if (dma_submit_error(s->cookie_rx[i]))
1399 			goto fail;
1400 
1401 	}
1402 
1403 	s->active_rx = s->cookie_rx[0];
1404 
1405 	dma_async_issue_pending(chan);
1406 	return 0;
1407 
1408 fail:
1409 	/* Switch to PIO */
1410 	if (!port_lock_held)
1411 		uart_port_lock_irqsave(port, &flags);
1412 	if (i)
1413 		dmaengine_terminate_async(chan);
1414 	sci_dma_rx_chan_invalidate(s);
1415 	sci_start_rx(port);
1416 	if (!port_lock_held)
1417 		uart_port_unlock_irqrestore(port, flags);
1418 	return -EAGAIN;
1419 }
1420 
1421 static void sci_dma_tx_work_fn(struct work_struct *work)
1422 {
1423 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1424 	struct dma_async_tx_descriptor *desc;
1425 	struct dma_chan *chan = s->chan_tx;
1426 	struct uart_port *port = &s->port;
1427 	struct circ_buf *xmit = &port->state->xmit;
1428 	unsigned long flags;
1429 	dma_addr_t buf;
1430 	int head, tail;
1431 
1432 	/*
1433 	 * DMA is idle now.
1434 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1435 	 * offsets and lengths. Since it is a circular buffer, we have to
1436 	 * transmit till the end, and then the rest. Take the port lock to get a
1437 	 * consistent xmit buffer state.
1438 	 */
1439 	uart_port_lock_irq(port);
1440 	head = xmit->head;
1441 	tail = xmit->tail;
1442 	buf = s->tx_dma_addr + tail;
1443 	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
1444 	if (!s->tx_dma_len) {
1445 		/* Transmit buffer has been flushed */
1446 		uart_port_unlock_irq(port);
1447 		return;
1448 	}
1449 
1450 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1451 					   DMA_MEM_TO_DEV,
1452 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1453 	if (!desc) {
1454 		uart_port_unlock_irq(port);
1455 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1456 		goto switch_to_pio;
1457 	}
1458 
1459 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1460 				   DMA_TO_DEVICE);
1461 
1462 	desc->callback = sci_dma_tx_complete;
1463 	desc->callback_param = s;
1464 	s->cookie_tx = dmaengine_submit(desc);
1465 	if (dma_submit_error(s->cookie_tx)) {
1466 		uart_port_unlock_irq(port);
1467 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1468 		goto switch_to_pio;
1469 	}
1470 
1471 	uart_port_unlock_irq(port);
1472 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1473 		__func__, xmit->buf, tail, head, s->cookie_tx);
1474 
1475 	dma_async_issue_pending(chan);
1476 	return;
1477 
1478 switch_to_pio:
1479 	uart_port_lock_irqsave(port, &flags);
1480 	s->chan_tx = NULL;
1481 	sci_start_tx(port);
1482 	uart_port_unlock_irqrestore(port, flags);
1483 	return;
1484 }
1485 
1486 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1487 {
1488 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1489 	struct dma_chan *chan = s->chan_rx;
1490 	struct uart_port *port = &s->port;
1491 	struct dma_tx_state state;
1492 	enum dma_status status;
1493 	unsigned long flags;
1494 	unsigned int read;
1495 	int active, count;
1496 
1497 	dev_dbg(port->dev, "DMA Rx timed out\n");
1498 
1499 	uart_port_lock_irqsave(port, &flags);
1500 
1501 	active = sci_dma_rx_find_active(s);
1502 	if (active < 0) {
1503 		uart_port_unlock_irqrestore(port, flags);
1504 		return HRTIMER_NORESTART;
1505 	}
1506 
1507 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1508 	if (status == DMA_COMPLETE) {
1509 		uart_port_unlock_irqrestore(port, flags);
1510 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1511 			s->active_rx, active);
1512 
1513 		/* Let packet complete handler take care of the packet */
1514 		return HRTIMER_NORESTART;
1515 	}
1516 
1517 	dmaengine_pause(chan);
1518 
1519 	/*
1520 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1521 	 * data keeps on coming until transaction is complete so check
1522 	 * for DMA_COMPLETE again
1523 	 * Let packet complete handler take care of the packet
1524 	 */
1525 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1526 	if (status == DMA_COMPLETE) {
1527 		uart_port_unlock_irqrestore(port, flags);
1528 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1529 		return HRTIMER_NORESTART;
1530 	}
1531 
1532 	/* Handle incomplete DMA receive */
1533 	dmaengine_terminate_async(s->chan_rx);
1534 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1535 
1536 	if (read) {
1537 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1538 		if (count)
1539 			tty_flip_buffer_push(&port->state->port);
1540 	}
1541 
1542 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1543 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1544 		sci_dma_rx_submit(s, true);
1545 
1546 	sci_dma_rx_reenable_irq(s);
1547 
1548 	uart_port_unlock_irqrestore(port, flags);
1549 
1550 	return HRTIMER_NORESTART;
1551 }
1552 
1553 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1554 					     enum dma_transfer_direction dir)
1555 {
1556 	struct dma_chan *chan;
1557 	struct dma_slave_config cfg;
1558 	int ret;
1559 
1560 	chan = dma_request_chan(port->dev, dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1561 	if (IS_ERR(chan)) {
1562 		dev_dbg(port->dev, "dma_request_chan failed\n");
1563 		return NULL;
1564 	}
1565 
1566 	memset(&cfg, 0, sizeof(cfg));
1567 	cfg.direction = dir;
1568 	cfg.dst_addr = port->mapbase +
1569 		(sci_getreg(port, SCxTDR)->offset << port->regshift);
1570 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1571 	cfg.src_addr = port->mapbase +
1572 		(sci_getreg(port, SCxRDR)->offset << port->regshift);
1573 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1574 
1575 	ret = dmaengine_slave_config(chan, &cfg);
1576 	if (ret) {
1577 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1578 		dma_release_channel(chan);
1579 		return NULL;
1580 	}
1581 
1582 	return chan;
1583 }
1584 
1585 static void sci_request_dma(struct uart_port *port)
1586 {
1587 	struct sci_port *s = to_sci_port(port);
1588 	struct dma_chan *chan;
1589 
1590 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1591 
1592 	/*
1593 	 * DMA on console may interfere with Kernel log messages which use
1594 	 * plain putchar(). So, simply don't use it with a console.
1595 	 */
1596 	if (uart_console(port))
1597 		return;
1598 
1599 	if (!port->dev->of_node)
1600 		return;
1601 
1602 	s->cookie_tx = -EINVAL;
1603 
1604 	/*
1605 	 * Don't request a dma channel if no channel was specified
1606 	 * in the device tree.
1607 	 */
1608 	if (!of_property_present(port->dev->of_node, "dmas"))
1609 		return;
1610 
1611 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1612 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1613 	if (chan) {
1614 		/* UART circular tx buffer is an aligned page. */
1615 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1616 						port->state->xmit.buf,
1617 						UART_XMIT_SIZE,
1618 						DMA_TO_DEVICE);
1619 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1620 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1621 			dma_release_channel(chan);
1622 		} else {
1623 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1624 				__func__, UART_XMIT_SIZE,
1625 				port->state->xmit.buf, &s->tx_dma_addr);
1626 
1627 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1628 			s->chan_tx_saved = s->chan_tx = chan;
1629 		}
1630 	}
1631 
1632 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1633 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1634 	if (chan) {
1635 		unsigned int i;
1636 		dma_addr_t dma;
1637 		void *buf;
1638 
1639 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1640 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1641 					 &dma, GFP_KERNEL);
1642 		if (!buf) {
1643 			dev_warn(port->dev,
1644 				 "Failed to allocate Rx dma buffer, using PIO\n");
1645 			dma_release_channel(chan);
1646 			return;
1647 		}
1648 
1649 		for (i = 0; i < 2; i++) {
1650 			struct scatterlist *sg = &s->sg_rx[i];
1651 
1652 			sg_init_table(sg, 1);
1653 			s->rx_buf[i] = buf;
1654 			sg_dma_address(sg) = dma;
1655 			sg_dma_len(sg) = s->buf_len_rx;
1656 
1657 			buf += s->buf_len_rx;
1658 			dma += s->buf_len_rx;
1659 		}
1660 
1661 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1662 		s->rx_timer.function = sci_dma_rx_timer_fn;
1663 
1664 		s->chan_rx_saved = s->chan_rx = chan;
1665 
1666 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1667 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1668 			sci_dma_rx_submit(s, false);
1669 	}
1670 }
1671 
1672 static void sci_free_dma(struct uart_port *port)
1673 {
1674 	struct sci_port *s = to_sci_port(port);
1675 
1676 	if (s->chan_tx_saved)
1677 		sci_dma_tx_release(s);
1678 	if (s->chan_rx_saved)
1679 		sci_dma_rx_release(s);
1680 }
1681 
1682 static void sci_flush_buffer(struct uart_port *port)
1683 {
1684 	struct sci_port *s = to_sci_port(port);
1685 
1686 	/*
1687 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1688 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1689 	 * pending transfers
1690 	 */
1691 	s->tx_dma_len = 0;
1692 	if (s->chan_tx) {
1693 		dmaengine_terminate_async(s->chan_tx);
1694 		s->cookie_tx = -EINVAL;
1695 	}
1696 }
1697 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1698 static inline void sci_request_dma(struct uart_port *port)
1699 {
1700 }
1701 
1702 static inline void sci_free_dma(struct uart_port *port)
1703 {
1704 }
1705 
1706 #define sci_flush_buffer	NULL
1707 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1708 
1709 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1710 {
1711 	struct uart_port *port = ptr;
1712 	struct sci_port *s = to_sci_port(port);
1713 
1714 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1715 	if (s->chan_rx) {
1716 		u16 scr = sci_serial_in(port, SCSCR);
1717 		u16 ssr = sci_serial_in(port, SCxSR);
1718 
1719 		/* Disable future Rx interrupts */
1720 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1721 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1722 			disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
1723 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1724 				scif_set_rtrg(port, 1);
1725 				scr |= SCSCR_RIE;
1726 			} else {
1727 				scr |= SCSCR_RDRQE;
1728 			}
1729 		} else {
1730 			if (sci_dma_rx_submit(s, false) < 0)
1731 				goto handle_pio;
1732 
1733 			scr &= ~SCSCR_RIE;
1734 		}
1735 		sci_serial_out(port, SCSCR, scr);
1736 		/* Clear current interrupt */
1737 		sci_serial_out(port, SCxSR,
1738 			       ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1739 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1740 			jiffies, s->rx_timeout);
1741 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1742 
1743 		return IRQ_HANDLED;
1744 	}
1745 
1746 handle_pio:
1747 #endif
1748 
1749 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1750 		if (!scif_rtrg_enabled(port))
1751 			scif_set_rtrg(port, s->rx_trigger);
1752 
1753 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1754 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1755 	}
1756 
1757 	/* I think sci_receive_chars has to be called irrespective
1758 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1759 	 * to be disabled?
1760 	 */
1761 	sci_receive_chars(port);
1762 
1763 	return IRQ_HANDLED;
1764 }
1765 
1766 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1767 {
1768 	struct uart_port *port = ptr;
1769 	unsigned long flags;
1770 
1771 	uart_port_lock_irqsave(port, &flags);
1772 	sci_transmit_chars(port);
1773 	uart_port_unlock_irqrestore(port, flags);
1774 
1775 	return IRQ_HANDLED;
1776 }
1777 
1778 static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
1779 {
1780 	struct uart_port *port = ptr;
1781 	unsigned long flags;
1782 	unsigned short ctrl;
1783 
1784 	if (port->type != PORT_SCI)
1785 		return sci_tx_interrupt(irq, ptr);
1786 
1787 	uart_port_lock_irqsave(port, &flags);
1788 	ctrl = sci_serial_in(port, SCSCR);
1789 	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
1790 	sci_serial_out(port, SCSCR, ctrl);
1791 	uart_port_unlock_irqrestore(port, flags);
1792 
1793 	return IRQ_HANDLED;
1794 }
1795 
1796 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1797 {
1798 	struct uart_port *port = ptr;
1799 
1800 	/* Handle BREAKs */
1801 	sci_handle_breaks(port);
1802 
1803 	/* drop invalid character received before break was detected */
1804 	sci_serial_in(port, SCxRDR);
1805 
1806 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1807 
1808 	return IRQ_HANDLED;
1809 }
1810 
1811 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1812 {
1813 	struct uart_port *port = ptr;
1814 	struct sci_port *s = to_sci_port(port);
1815 
1816 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1817 		/* Break and Error interrupts are muxed */
1818 		unsigned short ssr_status = sci_serial_in(port, SCxSR);
1819 
1820 		/* Break Interrupt */
1821 		if (ssr_status & SCxSR_BRK(port))
1822 			sci_br_interrupt(irq, ptr);
1823 
1824 		/* Break only? */
1825 		if (!(ssr_status & SCxSR_ERRORS(port)))
1826 			return IRQ_HANDLED;
1827 	}
1828 
1829 	/* Handle errors */
1830 	if (port->type == PORT_SCI) {
1831 		if (sci_handle_errors(port)) {
1832 			/* discard character in rx buffer */
1833 			sci_serial_in(port, SCxSR);
1834 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1835 		}
1836 	} else {
1837 		sci_handle_fifo_overrun(port);
1838 		if (!s->chan_rx)
1839 			sci_receive_chars(port);
1840 	}
1841 
1842 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1843 
1844 	/* Kick the transmission */
1845 	if (!s->chan_tx)
1846 		sci_tx_interrupt(irq, ptr);
1847 
1848 	return IRQ_HANDLED;
1849 }
1850 
1851 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1852 {
1853 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1854 	struct uart_port *port = ptr;
1855 	struct sci_port *s = to_sci_port(port);
1856 	irqreturn_t ret = IRQ_NONE;
1857 
1858 	ssr_status = sci_serial_in(port, SCxSR);
1859 	scr_status = sci_serial_in(port, SCSCR);
1860 	if (s->params->overrun_reg == SCxSR)
1861 		orer_status = ssr_status;
1862 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1863 		orer_status = sci_serial_in(port, s->params->overrun_reg);
1864 
1865 	err_enabled = scr_status & port_rx_irq_mask(port);
1866 
1867 	/* Tx Interrupt */
1868 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1869 	    !s->chan_tx)
1870 		ret = sci_tx_interrupt(irq, ptr);
1871 
1872 	/*
1873 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1874 	 * DR flags
1875 	 */
1876 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1877 	    (scr_status & SCSCR_RIE))
1878 		ret = sci_rx_interrupt(irq, ptr);
1879 
1880 	/* Error Interrupt */
1881 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1882 		ret = sci_er_interrupt(irq, ptr);
1883 
1884 	/* Break Interrupt */
1885 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1886 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1887 		ret = sci_br_interrupt(irq, ptr);
1888 
1889 	/* Overrun Interrupt */
1890 	if (orer_status & s->params->overrun_mask) {
1891 		sci_handle_fifo_overrun(port);
1892 		ret = IRQ_HANDLED;
1893 	}
1894 
1895 	return ret;
1896 }
1897 
1898 static const struct sci_irq_desc {
1899 	const char	*desc;
1900 	irq_handler_t	handler;
1901 } sci_irq_desc[] = {
1902 	/*
1903 	 * Split out handlers, the default case.
1904 	 */
1905 	[SCIx_ERI_IRQ] = {
1906 		.desc = "rx err",
1907 		.handler = sci_er_interrupt,
1908 	},
1909 
1910 	[SCIx_RXI_IRQ] = {
1911 		.desc = "rx full",
1912 		.handler = sci_rx_interrupt,
1913 	},
1914 
1915 	[SCIx_TXI_IRQ] = {
1916 		.desc = "tx empty",
1917 		.handler = sci_tx_interrupt,
1918 	},
1919 
1920 	[SCIx_BRI_IRQ] = {
1921 		.desc = "break",
1922 		.handler = sci_br_interrupt,
1923 	},
1924 
1925 	[SCIx_DRI_IRQ] = {
1926 		.desc = "rx ready",
1927 		.handler = sci_rx_interrupt,
1928 	},
1929 
1930 	[SCIx_TEI_IRQ] = {
1931 		.desc = "tx end",
1932 		.handler = sci_tx_end_interrupt,
1933 	},
1934 
1935 	/*
1936 	 * Special muxed handler.
1937 	 */
1938 	[SCIx_MUX_IRQ] = {
1939 		.desc = "mux",
1940 		.handler = sci_mpxed_interrupt,
1941 	},
1942 };
1943 
1944 static int sci_request_irq(struct sci_port *port)
1945 {
1946 	struct uart_port *up = &port->port;
1947 	int i, j, w, ret = 0;
1948 
1949 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1950 		const struct sci_irq_desc *desc;
1951 		int irq;
1952 
1953 		/* Check if already registered (muxed) */
1954 		for (w = 0; w < i; w++)
1955 			if (port->irqs[w] == port->irqs[i])
1956 				w = i + 1;
1957 		if (w > i)
1958 			continue;
1959 
1960 		if (SCIx_IRQ_IS_MUXED(port)) {
1961 			i = SCIx_MUX_IRQ;
1962 			irq = up->irq;
1963 		} else {
1964 			irq = port->irqs[i];
1965 
1966 			/*
1967 			 * Certain port types won't support all of the
1968 			 * available interrupt sources.
1969 			 */
1970 			if (unlikely(irq < 0))
1971 				continue;
1972 		}
1973 
1974 		desc = sci_irq_desc + i;
1975 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1976 					    dev_name(up->dev), desc->desc);
1977 		if (!port->irqstr[j]) {
1978 			ret = -ENOMEM;
1979 			goto out_nomem;
1980 		}
1981 
1982 		ret = request_irq(irq, desc->handler, up->irqflags,
1983 				  port->irqstr[j], port);
1984 		if (unlikely(ret)) {
1985 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1986 			goto out_noirq;
1987 		}
1988 	}
1989 
1990 	return 0;
1991 
1992 out_noirq:
1993 	while (--i >= 0)
1994 		free_irq(port->irqs[i], port);
1995 
1996 out_nomem:
1997 	while (--j >= 0)
1998 		kfree(port->irqstr[j]);
1999 
2000 	return ret;
2001 }
2002 
2003 static void sci_free_irq(struct sci_port *port)
2004 {
2005 	int i, j;
2006 
2007 	/*
2008 	 * Intentionally in reverse order so we iterate over the muxed
2009 	 * IRQ first.
2010 	 */
2011 	for (i = 0; i < SCIx_NR_IRQS; i++) {
2012 		int irq = port->irqs[i];
2013 
2014 		/*
2015 		 * Certain port types won't support all of the available
2016 		 * interrupt sources.
2017 		 */
2018 		if (unlikely(irq < 0))
2019 			continue;
2020 
2021 		/* Check if already freed (irq was muxed) */
2022 		for (j = 0; j < i; j++)
2023 			if (port->irqs[j] == irq)
2024 				j = i + 1;
2025 		if (j > i)
2026 			continue;
2027 
2028 		free_irq(port->irqs[i], port);
2029 		kfree(port->irqstr[i]);
2030 
2031 		if (SCIx_IRQ_IS_MUXED(port)) {
2032 			/* If there's only one IRQ, we're done. */
2033 			return;
2034 		}
2035 	}
2036 }
2037 
2038 static unsigned int sci_tx_empty(struct uart_port *port)
2039 {
2040 	unsigned short status = sci_serial_in(port, SCxSR);
2041 	unsigned short in_tx_fifo = sci_txfill(port);
2042 
2043 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2044 }
2045 
2046 static void sci_set_rts(struct uart_port *port, bool state)
2047 {
2048 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2049 		u16 data = sci_serial_in(port, SCPDR);
2050 
2051 		/* Active low */
2052 		if (state)
2053 			data &= ~SCPDR_RTSD;
2054 		else
2055 			data |= SCPDR_RTSD;
2056 		sci_serial_out(port, SCPDR, data);
2057 
2058 		/* RTS# is output */
2059 		sci_serial_out(port, SCPCR,
2060 			       sci_serial_in(port, SCPCR) | SCPCR_RTSC);
2061 	} else if (sci_getreg(port, SCSPTR)->size) {
2062 		u16 ctrl = sci_serial_in(port, SCSPTR);
2063 
2064 		/* Active low */
2065 		if (state)
2066 			ctrl &= ~SCSPTR_RTSDT;
2067 		else
2068 			ctrl |= SCSPTR_RTSDT;
2069 		sci_serial_out(port, SCSPTR, ctrl);
2070 	}
2071 }
2072 
2073 static bool sci_get_cts(struct uart_port *port)
2074 {
2075 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2076 		/* Active low */
2077 		return !(sci_serial_in(port, SCPDR) & SCPDR_CTSD);
2078 	} else if (sci_getreg(port, SCSPTR)->size) {
2079 		/* Active low */
2080 		return !(sci_serial_in(port, SCSPTR) & SCSPTR_CTSDT);
2081 	}
2082 
2083 	return true;
2084 }
2085 
2086 /*
2087  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2088  * CTS/RTS is supported in hardware by at least one port and controlled
2089  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2090  * handled via the ->init_pins() op, which is a bit of a one-way street,
2091  * lacking any ability to defer pin control -- this will later be
2092  * converted over to the GPIO framework).
2093  *
2094  * Other modes (such as loopback) are supported generically on certain
2095  * port types, but not others. For these it's sufficient to test for the
2096  * existence of the support register and simply ignore the port type.
2097  */
2098 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2099 {
2100 	struct sci_port *s = to_sci_port(port);
2101 
2102 	if (mctrl & TIOCM_LOOP) {
2103 		const struct plat_sci_reg *reg;
2104 
2105 		/*
2106 		 * Standard loopback mode for SCFCR ports.
2107 		 */
2108 		reg = sci_getreg(port, SCFCR);
2109 		if (reg->size)
2110 			sci_serial_out(port, SCFCR,
2111 				       sci_serial_in(port, SCFCR) | SCFCR_LOOP);
2112 	}
2113 
2114 	mctrl_gpio_set(s->gpios, mctrl);
2115 
2116 	if (!s->has_rtscts)
2117 		return;
2118 
2119 	if (!(mctrl & TIOCM_RTS)) {
2120 		/* Disable Auto RTS */
2121 		sci_serial_out(port, SCFCR,
2122 			       sci_serial_in(port, SCFCR) & ~SCFCR_MCE);
2123 
2124 		/* Clear RTS */
2125 		sci_set_rts(port, 0);
2126 	} else if (s->autorts) {
2127 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2128 			/* Enable RTS# pin function */
2129 			sci_serial_out(port, SCPCR,
2130 				sci_serial_in(port, SCPCR) & ~SCPCR_RTSC);
2131 		}
2132 
2133 		/* Enable Auto RTS */
2134 		sci_serial_out(port, SCFCR,
2135 			       sci_serial_in(port, SCFCR) | SCFCR_MCE);
2136 	} else {
2137 		/* Set RTS */
2138 		sci_set_rts(port, 1);
2139 	}
2140 }
2141 
2142 static unsigned int sci_get_mctrl(struct uart_port *port)
2143 {
2144 	struct sci_port *s = to_sci_port(port);
2145 	struct mctrl_gpios *gpios = s->gpios;
2146 	unsigned int mctrl = 0;
2147 
2148 	mctrl_gpio_get(gpios, &mctrl);
2149 
2150 	/*
2151 	 * CTS/RTS is handled in hardware when supported, while nothing
2152 	 * else is wired up.
2153 	 */
2154 	if (s->autorts) {
2155 		if (sci_get_cts(port))
2156 			mctrl |= TIOCM_CTS;
2157 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2158 		mctrl |= TIOCM_CTS;
2159 	}
2160 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2161 		mctrl |= TIOCM_DSR;
2162 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2163 		mctrl |= TIOCM_CAR;
2164 
2165 	return mctrl;
2166 }
2167 
2168 static void sci_enable_ms(struct uart_port *port)
2169 {
2170 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2171 }
2172 
2173 static void sci_break_ctl(struct uart_port *port, int break_state)
2174 {
2175 	unsigned short scscr, scsptr;
2176 	unsigned long flags;
2177 
2178 	/* check whether the port has SCSPTR */
2179 	if (!sci_getreg(port, SCSPTR)->size) {
2180 		/*
2181 		 * Not supported by hardware. Most parts couple break and rx
2182 		 * interrupts together, with break detection always enabled.
2183 		 */
2184 		return;
2185 	}
2186 
2187 	uart_port_lock_irqsave(port, &flags);
2188 	scsptr = sci_serial_in(port, SCSPTR);
2189 	scscr = sci_serial_in(port, SCSCR);
2190 
2191 	if (break_state == -1) {
2192 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2193 		scscr &= ~SCSCR_TE;
2194 	} else {
2195 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2196 		scscr |= SCSCR_TE;
2197 	}
2198 
2199 	sci_serial_out(port, SCSPTR, scsptr);
2200 	sci_serial_out(port, SCSCR, scscr);
2201 	uart_port_unlock_irqrestore(port, flags);
2202 }
2203 
2204 static int sci_startup(struct uart_port *port)
2205 {
2206 	struct sci_port *s = to_sci_port(port);
2207 	int ret;
2208 
2209 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2210 
2211 	sci_request_dma(port);
2212 
2213 	ret = sci_request_irq(s);
2214 	if (unlikely(ret < 0)) {
2215 		sci_free_dma(port);
2216 		return ret;
2217 	}
2218 
2219 	return 0;
2220 }
2221 
2222 static void sci_shutdown(struct uart_port *port)
2223 {
2224 	struct sci_port *s = to_sci_port(port);
2225 	unsigned long flags;
2226 	u16 scr;
2227 
2228 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2229 
2230 	s->autorts = false;
2231 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2232 
2233 	uart_port_lock_irqsave(port, &flags);
2234 	sci_stop_rx(port);
2235 	sci_stop_tx(port);
2236 	/*
2237 	 * Stop RX and TX, disable related interrupts, keep clock source
2238 	 * and HSCIF TOT bits
2239 	 */
2240 	scr = sci_serial_in(port, SCSCR);
2241 	sci_serial_out(port, SCSCR,
2242 		       scr & (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2243 	uart_port_unlock_irqrestore(port, flags);
2244 
2245 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2246 	if (s->chan_rx_saved) {
2247 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2248 			port->line);
2249 		hrtimer_cancel(&s->rx_timer);
2250 	}
2251 #endif
2252 
2253 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2254 		del_timer_sync(&s->rx_fifo_timer);
2255 	sci_free_irq(s);
2256 	sci_free_dma(port);
2257 }
2258 
2259 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2260 			unsigned int *srr)
2261 {
2262 	unsigned long freq = s->clk_rates[SCI_SCK];
2263 	int err, min_err = INT_MAX;
2264 	unsigned int sr;
2265 
2266 	if (s->port.type != PORT_HSCIF)
2267 		freq *= 2;
2268 
2269 	for_each_sr(sr, s) {
2270 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2271 		if (abs(err) >= abs(min_err))
2272 			continue;
2273 
2274 		min_err = err;
2275 		*srr = sr - 1;
2276 
2277 		if (!err)
2278 			break;
2279 	}
2280 
2281 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2282 		*srr + 1);
2283 	return min_err;
2284 }
2285 
2286 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2287 			unsigned long freq, unsigned int *dlr,
2288 			unsigned int *srr)
2289 {
2290 	int err, min_err = INT_MAX;
2291 	unsigned int sr, dl;
2292 
2293 	if (s->port.type != PORT_HSCIF)
2294 		freq *= 2;
2295 
2296 	for_each_sr(sr, s) {
2297 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2298 		dl = clamp(dl, 1U, 65535U);
2299 
2300 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2301 		if (abs(err) >= abs(min_err))
2302 			continue;
2303 
2304 		min_err = err;
2305 		*dlr = dl;
2306 		*srr = sr - 1;
2307 
2308 		if (!err)
2309 			break;
2310 	}
2311 
2312 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2313 		min_err, *dlr, *srr + 1);
2314 	return min_err;
2315 }
2316 
2317 /* calculate sample rate, BRR, and clock select */
2318 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2319 			  unsigned int *brr, unsigned int *srr,
2320 			  unsigned int *cks)
2321 {
2322 	unsigned long freq = s->clk_rates[SCI_FCK];
2323 	unsigned int sr, br, prediv, scrate, c;
2324 	int err, min_err = INT_MAX;
2325 
2326 	if (s->port.type != PORT_HSCIF)
2327 		freq *= 2;
2328 
2329 	/*
2330 	 * Find the combination of sample rate and clock select with the
2331 	 * smallest deviation from the desired baud rate.
2332 	 * Prefer high sample rates to maximise the receive margin.
2333 	 *
2334 	 * M: Receive margin (%)
2335 	 * N: Ratio of bit rate to clock (N = sampling rate)
2336 	 * D: Clock duty (D = 0 to 1.0)
2337 	 * L: Frame length (L = 9 to 12)
2338 	 * F: Absolute value of clock frequency deviation
2339 	 *
2340 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2341 	 *      (|D - 0.5| / N * (1 + F))|
2342 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2343 	 */
2344 	for_each_sr(sr, s) {
2345 		for (c = 0; c <= 3; c++) {
2346 			/* integerized formulas from HSCIF documentation */
2347 			prediv = sr << (2 * c + 1);
2348 
2349 			/*
2350 			 * We need to calculate:
2351 			 *
2352 			 *     br = freq / (prediv * bps) clamped to [1..256]
2353 			 *     err = freq / (br * prediv) - bps
2354 			 *
2355 			 * Watch out for overflow when calculating the desired
2356 			 * sampling clock rate!
2357 			 */
2358 			if (bps > UINT_MAX / prediv)
2359 				break;
2360 
2361 			scrate = prediv * bps;
2362 			br = DIV_ROUND_CLOSEST(freq, scrate);
2363 			br = clamp(br, 1U, 256U);
2364 
2365 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2366 			if (abs(err) >= abs(min_err))
2367 				continue;
2368 
2369 			min_err = err;
2370 			*brr = br - 1;
2371 			*srr = sr - 1;
2372 			*cks = c;
2373 
2374 			if (!err)
2375 				goto found;
2376 		}
2377 	}
2378 
2379 found:
2380 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2381 		min_err, *brr, *srr + 1, *cks);
2382 	return min_err;
2383 }
2384 
2385 static void sci_reset(struct uart_port *port)
2386 {
2387 	const struct plat_sci_reg *reg;
2388 	unsigned int status;
2389 	struct sci_port *s = to_sci_port(port);
2390 
2391 	sci_serial_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2392 
2393 	reg = sci_getreg(port, SCFCR);
2394 	if (reg->size)
2395 		sci_serial_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2396 
2397 	sci_clear_SCxSR(port,
2398 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2399 			SCxSR_BREAK_CLEAR(port));
2400 	if (sci_getreg(port, SCLSR)->size) {
2401 		status = sci_serial_in(port, SCLSR);
2402 		status &= ~(SCLSR_TO | SCLSR_ORER);
2403 		sci_serial_out(port, SCLSR, status);
2404 	}
2405 
2406 	if (s->rx_trigger > 1) {
2407 		if (s->rx_fifo_timeout) {
2408 			scif_set_rtrg(port, 1);
2409 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2410 		} else {
2411 			if (port->type == PORT_SCIFA ||
2412 			    port->type == PORT_SCIFB)
2413 				scif_set_rtrg(port, 1);
2414 			else
2415 				scif_set_rtrg(port, s->rx_trigger);
2416 		}
2417 	}
2418 }
2419 
2420 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2421 		            const struct ktermios *old)
2422 {
2423 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2424 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2425 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2426 	struct sci_port *s = to_sci_port(port);
2427 	const struct plat_sci_reg *reg;
2428 	int min_err = INT_MAX, err;
2429 	unsigned long max_freq = 0;
2430 	int best_clk = -1;
2431 	unsigned long flags;
2432 
2433 	if ((termios->c_cflag & CSIZE) == CS7) {
2434 		smr_val |= SCSMR_CHR;
2435 	} else {
2436 		termios->c_cflag &= ~CSIZE;
2437 		termios->c_cflag |= CS8;
2438 	}
2439 	if (termios->c_cflag & PARENB)
2440 		smr_val |= SCSMR_PE;
2441 	if (termios->c_cflag & PARODD)
2442 		smr_val |= SCSMR_PE | SCSMR_ODD;
2443 	if (termios->c_cflag & CSTOPB)
2444 		smr_val |= SCSMR_STOP;
2445 
2446 	/*
2447 	 * earlyprintk comes here early on with port->uartclk set to zero.
2448 	 * the clock framework is not up and running at this point so here
2449 	 * we assume that 115200 is the maximum baud rate. please note that
2450 	 * the baud rate is not programmed during earlyprintk - it is assumed
2451 	 * that the previous boot loader has enabled required clocks and
2452 	 * setup the baud rate generator hardware for us already.
2453 	 */
2454 	if (!port->uartclk) {
2455 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2456 		goto done;
2457 	}
2458 
2459 	for (i = 0; i < SCI_NUM_CLKS; i++)
2460 		max_freq = max(max_freq, s->clk_rates[i]);
2461 
2462 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2463 	if (!baud)
2464 		goto done;
2465 
2466 	/*
2467 	 * There can be multiple sources for the sampling clock.  Find the one
2468 	 * that gives us the smallest deviation from the desired baud rate.
2469 	 */
2470 
2471 	/* Optional Undivided External Clock */
2472 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2473 	    port->type != PORT_SCIFB) {
2474 		err = sci_sck_calc(s, baud, &srr1);
2475 		if (abs(err) < abs(min_err)) {
2476 			best_clk = SCI_SCK;
2477 			scr_val = SCSCR_CKE1;
2478 			sccks = SCCKS_CKS;
2479 			min_err = err;
2480 			srr = srr1;
2481 			if (!err)
2482 				goto done;
2483 		}
2484 	}
2485 
2486 	/* Optional BRG Frequency Divided External Clock */
2487 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2488 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2489 				   &srr1);
2490 		if (abs(err) < abs(min_err)) {
2491 			best_clk = SCI_SCIF_CLK;
2492 			scr_val = SCSCR_CKE1;
2493 			sccks = 0;
2494 			min_err = err;
2495 			dl = dl1;
2496 			srr = srr1;
2497 			if (!err)
2498 				goto done;
2499 		}
2500 	}
2501 
2502 	/* Optional BRG Frequency Divided Internal Clock */
2503 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2504 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2505 				   &srr1);
2506 		if (abs(err) < abs(min_err)) {
2507 			best_clk = SCI_BRG_INT;
2508 			scr_val = SCSCR_CKE1;
2509 			sccks = SCCKS_XIN;
2510 			min_err = err;
2511 			dl = dl1;
2512 			srr = srr1;
2513 			if (!min_err)
2514 				goto done;
2515 		}
2516 	}
2517 
2518 	/* Divided Functional Clock using standard Bit Rate Register */
2519 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2520 	if (abs(err) < abs(min_err)) {
2521 		best_clk = SCI_FCK;
2522 		scr_val = 0;
2523 		min_err = err;
2524 		brr = brr1;
2525 		srr = srr1;
2526 		cks = cks1;
2527 	}
2528 
2529 done:
2530 	if (best_clk >= 0)
2531 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2532 			s->clks[best_clk], baud, min_err);
2533 
2534 	sci_port_enable(s);
2535 
2536 	/*
2537 	 * Program the optional External Baud Rate Generator (BRG) first.
2538 	 * It controls the mux to select (H)SCK or frequency divided clock.
2539 	 */
2540 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2541 		sci_serial_out(port, SCDL, dl);
2542 		sci_serial_out(port, SCCKS, sccks);
2543 	}
2544 
2545 	uart_port_lock_irqsave(port, &flags);
2546 
2547 	sci_reset(port);
2548 
2549 	uart_update_timeout(port, termios->c_cflag, baud);
2550 
2551 	/* byte size and parity */
2552 	bits = tty_get_frame_size(termios->c_cflag);
2553 
2554 	if (sci_getreg(port, SEMR)->size)
2555 		sci_serial_out(port, SEMR, 0);
2556 
2557 	if (best_clk >= 0) {
2558 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2559 			switch (srr + 1) {
2560 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2561 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2562 			case 11: smr_val |= SCSMR_SRC_11; break;
2563 			case 13: smr_val |= SCSMR_SRC_13; break;
2564 			case 16: smr_val |= SCSMR_SRC_16; break;
2565 			case 17: smr_val |= SCSMR_SRC_17; break;
2566 			case 19: smr_val |= SCSMR_SRC_19; break;
2567 			case 27: smr_val |= SCSMR_SRC_27; break;
2568 			}
2569 		smr_val |= cks;
2570 		sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2571 		sci_serial_out(port, SCSMR, smr_val);
2572 		sci_serial_out(port, SCBRR, brr);
2573 		if (sci_getreg(port, HSSRR)->size) {
2574 			unsigned int hssrr = srr | HSCIF_SRE;
2575 			/* Calculate deviation from intended rate at the
2576 			 * center of the last stop bit in sampling clocks.
2577 			 */
2578 			int last_stop = bits * 2 - 1;
2579 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2580 							  (int)(srr + 1),
2581 							  2 * (int)baud);
2582 
2583 			if (abs(deviation) >= 2) {
2584 				/* At least two sampling clocks off at the
2585 				 * last stop bit; we can increase the error
2586 				 * margin by shifting the sampling point.
2587 				 */
2588 				int shift = clamp(deviation / 2, -8, 7);
2589 
2590 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2591 					 HSCIF_SRHP_MASK;
2592 				hssrr |= HSCIF_SRDE;
2593 			}
2594 			sci_serial_out(port, HSSRR, hssrr);
2595 		}
2596 
2597 		/* Wait one bit interval */
2598 		udelay((1000000 + (baud - 1)) / baud);
2599 	} else {
2600 		/* Don't touch the bit rate configuration */
2601 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2602 		smr_val |= sci_serial_in(port, SCSMR) &
2603 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2604 		sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2605 		sci_serial_out(port, SCSMR, smr_val);
2606 	}
2607 
2608 	sci_init_pins(port, termios->c_cflag);
2609 
2610 	port->status &= ~UPSTAT_AUTOCTS;
2611 	s->autorts = false;
2612 	reg = sci_getreg(port, SCFCR);
2613 	if (reg->size) {
2614 		unsigned short ctrl = sci_serial_in(port, SCFCR);
2615 
2616 		if ((port->flags & UPF_HARD_FLOW) &&
2617 		    (termios->c_cflag & CRTSCTS)) {
2618 			/* There is no CTS interrupt to restart the hardware */
2619 			port->status |= UPSTAT_AUTOCTS;
2620 			/* MCE is enabled when RTS is raised */
2621 			s->autorts = true;
2622 		}
2623 
2624 		/*
2625 		 * As we've done a sci_reset() above, ensure we don't
2626 		 * interfere with the FIFOs while toggling MCE. As the
2627 		 * reset values could still be set, simply mask them out.
2628 		 */
2629 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2630 
2631 		sci_serial_out(port, SCFCR, ctrl);
2632 	}
2633 	if (port->flags & UPF_HARD_FLOW) {
2634 		/* Refresh (Auto) RTS */
2635 		sci_set_mctrl(port, port->mctrl);
2636 	}
2637 
2638 	/*
2639 	 * For SCI, TE (transmit enable) must be set after setting TIE
2640 	 * (transmit interrupt enable) or in the same instruction to
2641 	 * start the transmitting process. So skip setting TE here for SCI.
2642 	 */
2643 	if (port->type != PORT_SCI)
2644 		scr_val |= SCSCR_TE;
2645 	scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2646 	sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2647 	if ((srr + 1 == 5) &&
2648 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2649 		/*
2650 		 * In asynchronous mode, when the sampling rate is 1/5, first
2651 		 * received data may become invalid on some SCIFA and SCIFB.
2652 		 * To avoid this problem wait more than 1 serial data time (1
2653 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2654 		 */
2655 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2656 	}
2657 
2658 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2659 	s->rx_frame = (10000 * bits) / (baud / 100);
2660 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2661 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2662 #endif
2663 
2664 	if ((termios->c_cflag & CREAD) != 0)
2665 		sci_start_rx(port);
2666 
2667 	uart_port_unlock_irqrestore(port, flags);
2668 
2669 	sci_port_disable(s);
2670 
2671 	if (UART_ENABLE_MS(port, termios->c_cflag))
2672 		sci_enable_ms(port);
2673 }
2674 
2675 static void sci_pm(struct uart_port *port, unsigned int state,
2676 		   unsigned int oldstate)
2677 {
2678 	struct sci_port *sci_port = to_sci_port(port);
2679 
2680 	switch (state) {
2681 	case UART_PM_STATE_OFF:
2682 		sci_port_disable(sci_port);
2683 		break;
2684 	default:
2685 		sci_port_enable(sci_port);
2686 		break;
2687 	}
2688 }
2689 
2690 static const char *sci_type(struct uart_port *port)
2691 {
2692 	switch (port->type) {
2693 	case PORT_IRDA:
2694 		return "irda";
2695 	case PORT_SCI:
2696 		return "sci";
2697 	case PORT_SCIF:
2698 		return "scif";
2699 	case PORT_SCIFA:
2700 		return "scifa";
2701 	case PORT_SCIFB:
2702 		return "scifb";
2703 	case PORT_HSCIF:
2704 		return "hscif";
2705 	}
2706 
2707 	return NULL;
2708 }
2709 
2710 static int sci_remap_port(struct uart_port *port)
2711 {
2712 	struct sci_port *sport = to_sci_port(port);
2713 
2714 	/*
2715 	 * Nothing to do if there's already an established membase.
2716 	 */
2717 	if (port->membase)
2718 		return 0;
2719 
2720 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2721 		port->membase = ioremap(port->mapbase, sport->reg_size);
2722 		if (unlikely(!port->membase)) {
2723 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2724 			return -ENXIO;
2725 		}
2726 	} else {
2727 		/*
2728 		 * For the simple (and majority of) cases where we don't
2729 		 * need to do any remapping, just cast the cookie
2730 		 * directly.
2731 		 */
2732 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2733 	}
2734 
2735 	return 0;
2736 }
2737 
2738 static void sci_release_port(struct uart_port *port)
2739 {
2740 	struct sci_port *sport = to_sci_port(port);
2741 
2742 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2743 		iounmap(port->membase);
2744 		port->membase = NULL;
2745 	}
2746 
2747 	release_mem_region(port->mapbase, sport->reg_size);
2748 }
2749 
2750 static int sci_request_port(struct uart_port *port)
2751 {
2752 	struct resource *res;
2753 	struct sci_port *sport = to_sci_port(port);
2754 	int ret;
2755 
2756 	res = request_mem_region(port->mapbase, sport->reg_size,
2757 				 dev_name(port->dev));
2758 	if (unlikely(res == NULL)) {
2759 		dev_err(port->dev, "request_mem_region failed.");
2760 		return -EBUSY;
2761 	}
2762 
2763 	ret = sci_remap_port(port);
2764 	if (unlikely(ret != 0)) {
2765 		release_resource(res);
2766 		return ret;
2767 	}
2768 
2769 	return 0;
2770 }
2771 
2772 static void sci_config_port(struct uart_port *port, int flags)
2773 {
2774 	if (flags & UART_CONFIG_TYPE) {
2775 		struct sci_port *sport = to_sci_port(port);
2776 
2777 		port->type = sport->cfg->type;
2778 		sci_request_port(port);
2779 	}
2780 }
2781 
2782 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2783 {
2784 	if (ser->baud_base < 2400)
2785 		/* No paper tape reader for Mitch.. */
2786 		return -EINVAL;
2787 
2788 	return 0;
2789 }
2790 
2791 static const struct uart_ops sci_uart_ops = {
2792 	.tx_empty	= sci_tx_empty,
2793 	.set_mctrl	= sci_set_mctrl,
2794 	.get_mctrl	= sci_get_mctrl,
2795 	.start_tx	= sci_start_tx,
2796 	.stop_tx	= sci_stop_tx,
2797 	.stop_rx	= sci_stop_rx,
2798 	.enable_ms	= sci_enable_ms,
2799 	.break_ctl	= sci_break_ctl,
2800 	.startup	= sci_startup,
2801 	.shutdown	= sci_shutdown,
2802 	.flush_buffer	= sci_flush_buffer,
2803 	.set_termios	= sci_set_termios,
2804 	.pm		= sci_pm,
2805 	.type		= sci_type,
2806 	.release_port	= sci_release_port,
2807 	.request_port	= sci_request_port,
2808 	.config_port	= sci_config_port,
2809 	.verify_port	= sci_verify_port,
2810 #ifdef CONFIG_CONSOLE_POLL
2811 	.poll_get_char	= sci_poll_get_char,
2812 	.poll_put_char	= sci_poll_put_char,
2813 #endif
2814 };
2815 
2816 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2817 {
2818 	const char *clk_names[] = {
2819 		[SCI_FCK] = "fck",
2820 		[SCI_SCK] = "sck",
2821 		[SCI_BRG_INT] = "brg_int",
2822 		[SCI_SCIF_CLK] = "scif_clk",
2823 	};
2824 	struct clk *clk;
2825 	unsigned int i;
2826 
2827 	if (sci_port->cfg->type == PORT_HSCIF)
2828 		clk_names[SCI_SCK] = "hsck";
2829 
2830 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2831 		clk = devm_clk_get_optional(dev, clk_names[i]);
2832 		if (IS_ERR(clk))
2833 			return PTR_ERR(clk);
2834 
2835 		if (!clk && i == SCI_FCK) {
2836 			/*
2837 			 * Not all SH platforms declare a clock lookup entry
2838 			 * for SCI devices, in which case we need to get the
2839 			 * global "peripheral_clk" clock.
2840 			 */
2841 			clk = devm_clk_get(dev, "peripheral_clk");
2842 			if (IS_ERR(clk))
2843 				return dev_err_probe(dev, PTR_ERR(clk),
2844 						     "failed to get %s\n",
2845 						     clk_names[i]);
2846 		}
2847 
2848 		if (!clk)
2849 			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2850 		else
2851 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2852 				clk, clk_get_rate(clk));
2853 		sci_port->clks[i] = clk;
2854 	}
2855 	return 0;
2856 }
2857 
2858 static const struct sci_port_params *
2859 sci_probe_regmap(const struct plat_sci_port *cfg)
2860 {
2861 	unsigned int regtype;
2862 
2863 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2864 		return &sci_port_params[cfg->regtype];
2865 
2866 	switch (cfg->type) {
2867 	case PORT_SCI:
2868 		regtype = SCIx_SCI_REGTYPE;
2869 		break;
2870 	case PORT_IRDA:
2871 		regtype = SCIx_IRDA_REGTYPE;
2872 		break;
2873 	case PORT_SCIFA:
2874 		regtype = SCIx_SCIFA_REGTYPE;
2875 		break;
2876 	case PORT_SCIFB:
2877 		regtype = SCIx_SCIFB_REGTYPE;
2878 		break;
2879 	case PORT_SCIF:
2880 		/*
2881 		 * The SH-4 is a bit of a misnomer here, although that's
2882 		 * where this particular port layout originated. This
2883 		 * configuration (or some slight variation thereof)
2884 		 * remains the dominant model for all SCIFs.
2885 		 */
2886 		regtype = SCIx_SH4_SCIF_REGTYPE;
2887 		break;
2888 	case PORT_HSCIF:
2889 		regtype = SCIx_HSCIF_REGTYPE;
2890 		break;
2891 	default:
2892 		pr_err("Can't probe register map for given port\n");
2893 		return NULL;
2894 	}
2895 
2896 	return &sci_port_params[regtype];
2897 }
2898 
2899 static int sci_init_single(struct platform_device *dev,
2900 			   struct sci_port *sci_port, unsigned int index,
2901 			   const struct plat_sci_port *p, bool early)
2902 {
2903 	struct uart_port *port = &sci_port->port;
2904 	const struct resource *res;
2905 	unsigned int i;
2906 	int ret;
2907 
2908 	sci_port->cfg	= p;
2909 
2910 	port->ops	= &sci_uart_ops;
2911 	port->iotype	= UPIO_MEM;
2912 	port->line	= index;
2913 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2914 
2915 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2916 	if (res == NULL)
2917 		return -ENOMEM;
2918 
2919 	port->mapbase = res->start;
2920 	sci_port->reg_size = resource_size(res);
2921 
2922 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2923 		if (i)
2924 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2925 		else
2926 			sci_port->irqs[i] = platform_get_irq(dev, i);
2927 	}
2928 
2929 	/*
2930 	 * The fourth interrupt on SCI port is transmit end interrupt, so
2931 	 * shuffle the interrupts.
2932 	 */
2933 	if (p->type == PORT_SCI)
2934 		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
2935 
2936 	/* The SCI generates several interrupts. They can be muxed together or
2937 	 * connected to different interrupt lines. In the muxed case only one
2938 	 * interrupt resource is specified as there is only one interrupt ID.
2939 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2940 	 * from the SCI, however those signals might have their own individual
2941 	 * interrupt ID numbers, or muxed together with another interrupt.
2942 	 */
2943 	if (sci_port->irqs[0] < 0)
2944 		return -ENXIO;
2945 
2946 	if (sci_port->irqs[1] < 0)
2947 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2948 			sci_port->irqs[i] = sci_port->irqs[0];
2949 
2950 	sci_port->params = sci_probe_regmap(p);
2951 	if (unlikely(sci_port->params == NULL))
2952 		return -EINVAL;
2953 
2954 	switch (p->type) {
2955 	case PORT_SCIFB:
2956 		sci_port->rx_trigger = 48;
2957 		break;
2958 	case PORT_HSCIF:
2959 		sci_port->rx_trigger = 64;
2960 		break;
2961 	case PORT_SCIFA:
2962 		sci_port->rx_trigger = 32;
2963 		break;
2964 	case PORT_SCIF:
2965 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2966 			/* RX triggering not implemented for this IP */
2967 			sci_port->rx_trigger = 1;
2968 		else
2969 			sci_port->rx_trigger = 8;
2970 		break;
2971 	default:
2972 		sci_port->rx_trigger = 1;
2973 		break;
2974 	}
2975 
2976 	sci_port->rx_fifo_timeout = 0;
2977 	sci_port->hscif_tot = 0;
2978 
2979 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2980 	 * match the SoC datasheet, this should be investigated. Let platform
2981 	 * data override the sampling rate for now.
2982 	 */
2983 	sci_port->sampling_rate_mask = p->sampling_rate
2984 				     ? SCI_SR(p->sampling_rate)
2985 				     : sci_port->params->sampling_rate_mask;
2986 
2987 	if (!early) {
2988 		ret = sci_init_clocks(sci_port, &dev->dev);
2989 		if (ret < 0)
2990 			return ret;
2991 
2992 		port->dev = &dev->dev;
2993 
2994 		pm_runtime_enable(&dev->dev);
2995 	}
2996 
2997 	port->type		= p->type;
2998 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2999 	port->fifosize		= sci_port->params->fifosize;
3000 
3001 	if (port->type == PORT_SCI && !dev->dev.of_node) {
3002 		if (sci_port->reg_size >= 0x20)
3003 			port->regshift = 2;
3004 		else
3005 			port->regshift = 1;
3006 	}
3007 
3008 	/*
3009 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
3010 	 * for the multi-IRQ ports, which is where we are primarily
3011 	 * concerned with the shutdown path synchronization.
3012 	 *
3013 	 * For the muxed case there's nothing more to do.
3014 	 */
3015 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
3016 	port->irqflags		= 0;
3017 
3018 	return 0;
3019 }
3020 
3021 static void sci_cleanup_single(struct sci_port *port)
3022 {
3023 	pm_runtime_disable(port->port.dev);
3024 }
3025 
3026 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3027     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3028 static void serial_console_putchar(struct uart_port *port, unsigned char ch)
3029 {
3030 	sci_poll_put_char(port, ch);
3031 }
3032 
3033 /*
3034  *	Print a string to the serial port trying not to disturb
3035  *	any possible real use of the port...
3036  */
3037 static void serial_console_write(struct console *co, const char *s,
3038 				 unsigned count)
3039 {
3040 	struct sci_port *sci_port = &sci_ports[co->index];
3041 	struct uart_port *port = &sci_port->port;
3042 	unsigned short bits, ctrl, ctrl_temp;
3043 	unsigned long flags;
3044 	int locked = 1;
3045 
3046 	if (port->sysrq)
3047 		locked = 0;
3048 	else if (oops_in_progress)
3049 		locked = uart_port_trylock_irqsave(port, &flags);
3050 	else
3051 		uart_port_lock_irqsave(port, &flags);
3052 
3053 	/* first save SCSCR then disable interrupts, keep clock source */
3054 	ctrl = sci_serial_in(port, SCSCR);
3055 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3056 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3057 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3058 	sci_serial_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3059 
3060 	uart_console_write(port, s, count, serial_console_putchar);
3061 
3062 	/* wait until fifo is empty and last bit has been transmitted */
3063 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3064 	while ((sci_serial_in(port, SCxSR) & bits) != bits)
3065 		cpu_relax();
3066 
3067 	/* restore the SCSCR */
3068 	sci_serial_out(port, SCSCR, ctrl);
3069 
3070 	if (locked)
3071 		uart_port_unlock_irqrestore(port, flags);
3072 }
3073 
3074 static int serial_console_setup(struct console *co, char *options)
3075 {
3076 	struct sci_port *sci_port;
3077 	struct uart_port *port;
3078 	int baud = 115200;
3079 	int bits = 8;
3080 	int parity = 'n';
3081 	int flow = 'n';
3082 	int ret;
3083 
3084 	/*
3085 	 * Refuse to handle any bogus ports.
3086 	 */
3087 	if (co->index < 0 || co->index >= SCI_NPORTS)
3088 		return -ENODEV;
3089 
3090 	sci_port = &sci_ports[co->index];
3091 	port = &sci_port->port;
3092 
3093 	/*
3094 	 * Refuse to handle uninitialized ports.
3095 	 */
3096 	if (!port->ops)
3097 		return -ENODEV;
3098 
3099 	ret = sci_remap_port(port);
3100 	if (unlikely(ret != 0))
3101 		return ret;
3102 
3103 	if (options)
3104 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3105 
3106 	return uart_set_options(port, co, baud, parity, bits, flow);
3107 }
3108 
3109 static struct console serial_console = {
3110 	.name		= "ttySC",
3111 	.device		= uart_console_device,
3112 	.write		= serial_console_write,
3113 	.setup		= serial_console_setup,
3114 	.flags		= CON_PRINTBUFFER,
3115 	.index		= -1,
3116 	.data		= &sci_uart_driver,
3117 };
3118 
3119 #ifdef CONFIG_SUPERH
3120 static char early_serial_buf[32];
3121 
3122 static int early_serial_console_setup(struct console *co, char *options)
3123 {
3124 	/*
3125 	 * This early console is always registered using the earlyprintk=
3126 	 * parameter, which does not call add_preferred_console(). Thus
3127 	 * @options is always NULL and the options for this early console
3128 	 * are passed using a custom buffer.
3129 	 */
3130 	WARN_ON(options);
3131 
3132 	return serial_console_setup(co, early_serial_buf);
3133 }
3134 
3135 static struct console early_serial_console = {
3136 	.name           = "early_ttySC",
3137 	.write          = serial_console_write,
3138 	.setup		= early_serial_console_setup,
3139 	.flags          = CON_PRINTBUFFER,
3140 	.index		= -1,
3141 };
3142 
3143 static int sci_probe_earlyprintk(struct platform_device *pdev)
3144 {
3145 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3146 
3147 	if (early_serial_console.data)
3148 		return -EEXIST;
3149 
3150 	early_serial_console.index = pdev->id;
3151 
3152 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3153 
3154 	if (!strstr(early_serial_buf, "keep"))
3155 		early_serial_console.flags |= CON_BOOT;
3156 
3157 	register_console(&early_serial_console);
3158 	return 0;
3159 }
3160 #endif
3161 
3162 #define SCI_CONSOLE	(&serial_console)
3163 
3164 #else
3165 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3166 {
3167 	return -EINVAL;
3168 }
3169 
3170 #define SCI_CONSOLE	NULL
3171 
3172 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3173 
3174 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3175 
3176 static DEFINE_MUTEX(sci_uart_registration_lock);
3177 static struct uart_driver sci_uart_driver = {
3178 	.owner		= THIS_MODULE,
3179 	.driver_name	= "sci",
3180 	.dev_name	= "ttySC",
3181 	.major		= SCI_MAJOR,
3182 	.minor		= SCI_MINOR_START,
3183 	.nr		= SCI_NPORTS,
3184 	.cons		= SCI_CONSOLE,
3185 };
3186 
3187 static void sci_remove(struct platform_device *dev)
3188 {
3189 	struct sci_port *port = platform_get_drvdata(dev);
3190 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3191 
3192 	sci_ports_in_use &= ~BIT(port->port.line);
3193 	uart_remove_one_port(&sci_uart_driver, &port->port);
3194 
3195 	sci_cleanup_single(port);
3196 
3197 	if (port->port.fifosize > 1)
3198 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3199 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3200 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3201 }
3202 
3203 
3204 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3205 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3206 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3207 
3208 static const struct of_device_id of_sci_match[] __maybe_unused = {
3209 	/* SoC-specific types */
3210 	{
3211 		.compatible = "renesas,scif-r7s72100",
3212 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3213 	},
3214 	{
3215 		.compatible = "renesas,scif-r7s9210",
3216 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3217 	},
3218 	{
3219 		.compatible = "renesas,scif-r9a07g044",
3220 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3221 	},
3222 	/* Family-specific types */
3223 	{
3224 		.compatible = "renesas,rcar-gen1-scif",
3225 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3226 	}, {
3227 		.compatible = "renesas,rcar-gen2-scif",
3228 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3229 	}, {
3230 		.compatible = "renesas,rcar-gen3-scif",
3231 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3232 	}, {
3233 		.compatible = "renesas,rcar-gen4-scif",
3234 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3235 	},
3236 	/* Generic types */
3237 	{
3238 		.compatible = "renesas,scif",
3239 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3240 	}, {
3241 		.compatible = "renesas,scifa",
3242 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3243 	}, {
3244 		.compatible = "renesas,scifb",
3245 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3246 	}, {
3247 		.compatible = "renesas,hscif",
3248 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3249 	}, {
3250 		.compatible = "renesas,sci",
3251 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3252 	}, {
3253 		/* Terminator */
3254 	},
3255 };
3256 MODULE_DEVICE_TABLE(of, of_sci_match);
3257 
3258 static void sci_reset_control_assert(void *data)
3259 {
3260 	reset_control_assert(data);
3261 }
3262 
3263 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3264 					  unsigned int *dev_id)
3265 {
3266 	struct device_node *np = pdev->dev.of_node;
3267 	struct reset_control *rstc;
3268 	struct plat_sci_port *p;
3269 	struct sci_port *sp;
3270 	const void *data;
3271 	int id, ret;
3272 
3273 	if (!IS_ENABLED(CONFIG_OF) || !np)
3274 		return ERR_PTR(-EINVAL);
3275 
3276 	data = of_device_get_match_data(&pdev->dev);
3277 
3278 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3279 	if (IS_ERR(rstc))
3280 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3281 					     "failed to get reset ctrl\n"));
3282 
3283 	ret = reset_control_deassert(rstc);
3284 	if (ret) {
3285 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3286 		return ERR_PTR(ret);
3287 	}
3288 
3289 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3290 	if (ret) {
3291 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3292 			ret);
3293 		return ERR_PTR(ret);
3294 	}
3295 
3296 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3297 	if (!p)
3298 		return ERR_PTR(-ENOMEM);
3299 
3300 	/* Get the line number from the aliases node. */
3301 	id = of_alias_get_id(np, "serial");
3302 	if (id < 0 && ~sci_ports_in_use)
3303 		id = ffz(sci_ports_in_use);
3304 	if (id < 0) {
3305 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3306 		return ERR_PTR(-EINVAL);
3307 	}
3308 	if (id >= ARRAY_SIZE(sci_ports)) {
3309 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3310 		return ERR_PTR(-EINVAL);
3311 	}
3312 
3313 	sp = &sci_ports[id];
3314 	*dev_id = id;
3315 
3316 	p->type = SCI_OF_TYPE(data);
3317 	p->regtype = SCI_OF_REGTYPE(data);
3318 
3319 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3320 
3321 	return p;
3322 }
3323 
3324 static int sci_probe_single(struct platform_device *dev,
3325 				      unsigned int index,
3326 				      struct plat_sci_port *p,
3327 				      struct sci_port *sciport)
3328 {
3329 	int ret;
3330 
3331 	/* Sanity check */
3332 	if (unlikely(index >= SCI_NPORTS)) {
3333 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3334 			   index+1, SCI_NPORTS);
3335 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3336 		return -EINVAL;
3337 	}
3338 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3339 	if (sci_ports_in_use & BIT(index))
3340 		return -EBUSY;
3341 
3342 	mutex_lock(&sci_uart_registration_lock);
3343 	if (!sci_uart_driver.state) {
3344 		ret = uart_register_driver(&sci_uart_driver);
3345 		if (ret) {
3346 			mutex_unlock(&sci_uart_registration_lock);
3347 			return ret;
3348 		}
3349 	}
3350 	mutex_unlock(&sci_uart_registration_lock);
3351 
3352 	ret = sci_init_single(dev, sciport, index, p, false);
3353 	if (ret)
3354 		return ret;
3355 
3356 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3357 	if (IS_ERR(sciport->gpios))
3358 		return PTR_ERR(sciport->gpios);
3359 
3360 	if (sciport->has_rtscts) {
3361 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3362 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3363 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3364 			return -EINVAL;
3365 		}
3366 		sciport->port.flags |= UPF_HARD_FLOW;
3367 	}
3368 
3369 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3370 	if (ret) {
3371 		sci_cleanup_single(sciport);
3372 		return ret;
3373 	}
3374 
3375 	return 0;
3376 }
3377 
3378 static int sci_probe(struct platform_device *dev)
3379 {
3380 	struct plat_sci_port *p;
3381 	struct sci_port *sp;
3382 	unsigned int dev_id;
3383 	int ret;
3384 
3385 	/*
3386 	 * If we've come here via earlyprintk initialization, head off to
3387 	 * the special early probe. We don't have sufficient device state
3388 	 * to make it beyond this yet.
3389 	 */
3390 #ifdef CONFIG_SUPERH
3391 	if (is_sh_early_platform_device(dev))
3392 		return sci_probe_earlyprintk(dev);
3393 #endif
3394 
3395 	if (dev->dev.of_node) {
3396 		p = sci_parse_dt(dev, &dev_id);
3397 		if (IS_ERR(p))
3398 			return PTR_ERR(p);
3399 	} else {
3400 		p = dev->dev.platform_data;
3401 		if (p == NULL) {
3402 			dev_err(&dev->dev, "no platform data supplied\n");
3403 			return -EINVAL;
3404 		}
3405 
3406 		dev_id = dev->id;
3407 	}
3408 
3409 	sp = &sci_ports[dev_id];
3410 	platform_set_drvdata(dev, sp);
3411 
3412 	ret = sci_probe_single(dev, dev_id, p, sp);
3413 	if (ret)
3414 		return ret;
3415 
3416 	if (sp->port.fifosize > 1) {
3417 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3418 		if (ret)
3419 			return ret;
3420 	}
3421 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3422 	    sp->port.type == PORT_HSCIF) {
3423 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3424 		if (ret) {
3425 			if (sp->port.fifosize > 1) {
3426 				device_remove_file(&dev->dev,
3427 						   &dev_attr_rx_fifo_trigger);
3428 			}
3429 			return ret;
3430 		}
3431 	}
3432 
3433 #ifdef CONFIG_SH_STANDARD_BIOS
3434 	sh_bios_gdb_detach();
3435 #endif
3436 
3437 	sci_ports_in_use |= BIT(dev_id);
3438 	return 0;
3439 }
3440 
3441 static __maybe_unused int sci_suspend(struct device *dev)
3442 {
3443 	struct sci_port *sport = dev_get_drvdata(dev);
3444 
3445 	if (sport)
3446 		uart_suspend_port(&sci_uart_driver, &sport->port);
3447 
3448 	return 0;
3449 }
3450 
3451 static __maybe_unused int sci_resume(struct device *dev)
3452 {
3453 	struct sci_port *sport = dev_get_drvdata(dev);
3454 
3455 	if (sport)
3456 		uart_resume_port(&sci_uart_driver, &sport->port);
3457 
3458 	return 0;
3459 }
3460 
3461 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3462 
3463 static struct platform_driver sci_driver = {
3464 	.probe		= sci_probe,
3465 	.remove_new	= sci_remove,
3466 	.driver		= {
3467 		.name	= "sh-sci",
3468 		.pm	= &sci_dev_pm_ops,
3469 		.of_match_table = of_match_ptr(of_sci_match),
3470 	},
3471 };
3472 
3473 static int __init sci_init(void)
3474 {
3475 	pr_info("%s\n", banner);
3476 
3477 	return platform_driver_register(&sci_driver);
3478 }
3479 
3480 static void __exit sci_exit(void)
3481 {
3482 	platform_driver_unregister(&sci_driver);
3483 
3484 	if (sci_uart_driver.state)
3485 		uart_unregister_driver(&sci_uart_driver);
3486 }
3487 
3488 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3489 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3490 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3491 #endif
3492 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3493 static struct plat_sci_port port_cfg __initdata;
3494 
3495 static int __init early_console_setup(struct earlycon_device *device,
3496 				      int type)
3497 {
3498 	if (!device->port.membase)
3499 		return -ENODEV;
3500 
3501 	device->port.type = type;
3502 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3503 	port_cfg.type = type;
3504 	sci_ports[0].cfg = &port_cfg;
3505 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3506 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3507 	sci_serial_out(&sci_ports[0].port, SCSCR,
3508 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3509 
3510 	device->con->write = serial_console_write;
3511 	return 0;
3512 }
3513 static int __init sci_early_console_setup(struct earlycon_device *device,
3514 					  const char *opt)
3515 {
3516 	return early_console_setup(device, PORT_SCI);
3517 }
3518 static int __init scif_early_console_setup(struct earlycon_device *device,
3519 					  const char *opt)
3520 {
3521 	return early_console_setup(device, PORT_SCIF);
3522 }
3523 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3524 					  const char *opt)
3525 {
3526 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3527 	return early_console_setup(device, PORT_SCIF);
3528 }
3529 
3530 static int __init scifa_early_console_setup(struct earlycon_device *device,
3531 					  const char *opt)
3532 {
3533 	return early_console_setup(device, PORT_SCIFA);
3534 }
3535 static int __init scifb_early_console_setup(struct earlycon_device *device,
3536 					  const char *opt)
3537 {
3538 	return early_console_setup(device, PORT_SCIFB);
3539 }
3540 static int __init hscif_early_console_setup(struct earlycon_device *device,
3541 					  const char *opt)
3542 {
3543 	return early_console_setup(device, PORT_HSCIF);
3544 }
3545 
3546 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3547 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3548 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3549 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3550 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3551 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3552 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3553 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3554 
3555 module_init(sci_init);
3556 module_exit(sci_exit);
3557 
3558 MODULE_LICENSE("GPL");
3559 MODULE_ALIAS("platform:sh-sci");
3560 MODULE_AUTHOR("Paul Mundt");
3561 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3562