xref: /linux/drivers/tty/serial/sh-sci.c (revision 019b383d1132e4051de0d2e43254454b86538cf4)
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 = serial_port_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 			serial_port_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 = serial_port_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 		serial_port_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 = serial_port_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 	serial_port_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 = serial_port_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 	serial_port_out(port, SCSCR, ctrl);
649 }
650 
651 static void sci_stop_rx(struct uart_port *port)
652 {
653 	unsigned short ctrl;
654 
655 	ctrl = serial_port_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 	serial_port_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 		serial_port_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 		serial_port_out(port, SCxSR,
674 				serial_port_in(port, SCxSR) & mask);
675 	} else {
676 		/* Store the mask, clear parity/framing errors */
677 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
678 	}
679 }
680 
681 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
682     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
683 
684 #ifdef CONFIG_CONSOLE_POLL
685 static int sci_poll_get_char(struct uart_port *port)
686 {
687 	unsigned short status;
688 	int c;
689 
690 	do {
691 		status = serial_port_in(port, SCxSR);
692 		if (status & SCxSR_ERRORS(port)) {
693 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
694 			continue;
695 		}
696 		break;
697 	} while (1);
698 
699 	if (!(status & SCxSR_RDxF(port)))
700 		return NO_POLL_CHAR;
701 
702 	c = serial_port_in(port, SCxRDR);
703 
704 	/* Dummy read */
705 	serial_port_in(port, SCxSR);
706 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
707 
708 	return c;
709 }
710 #endif
711 
712 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
713 {
714 	unsigned short status;
715 
716 	do {
717 		status = serial_port_in(port, SCxSR);
718 	} while (!(status & SCxSR_TDxE(port)));
719 
720 	serial_port_out(port, SCxTDR, c);
721 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
722 }
723 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
724 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
725 
726 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
727 {
728 	struct sci_port *s = to_sci_port(port);
729 
730 	/*
731 	 * Use port-specific handler if provided.
732 	 */
733 	if (s->cfg->ops && s->cfg->ops->init_pins) {
734 		s->cfg->ops->init_pins(port, cflag);
735 		return;
736 	}
737 
738 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
739 		u16 data = serial_port_in(port, SCPDR);
740 		u16 ctrl = serial_port_in(port, SCPCR);
741 
742 		/* Enable RXD and TXD pin functions */
743 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
744 		if (to_sci_port(port)->has_rtscts) {
745 			/* RTS# is output, active low, unless autorts */
746 			if (!(port->mctrl & TIOCM_RTS)) {
747 				ctrl |= SCPCR_RTSC;
748 				data |= SCPDR_RTSD;
749 			} else if (!s->autorts) {
750 				ctrl |= SCPCR_RTSC;
751 				data &= ~SCPDR_RTSD;
752 			} else {
753 				/* Enable RTS# pin function */
754 				ctrl &= ~SCPCR_RTSC;
755 			}
756 			/* Enable CTS# pin function */
757 			ctrl &= ~SCPCR_CTSC;
758 		}
759 		serial_port_out(port, SCPDR, data);
760 		serial_port_out(port, SCPCR, ctrl);
761 	} else if (sci_getreg(port, SCSPTR)->size) {
762 		u16 status = serial_port_in(port, SCSPTR);
763 
764 		/* RTS# is always output; and active low, unless autorts */
765 		status |= SCSPTR_RTSIO;
766 		if (!(port->mctrl & TIOCM_RTS))
767 			status |= SCSPTR_RTSDT;
768 		else if (!s->autorts)
769 			status &= ~SCSPTR_RTSDT;
770 		/* CTS# and SCK are inputs */
771 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
772 		serial_port_out(port, SCSPTR, status);
773 	}
774 }
775 
776 static int sci_txfill(struct uart_port *port)
777 {
778 	struct sci_port *s = to_sci_port(port);
779 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
780 	const struct plat_sci_reg *reg;
781 
782 	reg = sci_getreg(port, SCTFDR);
783 	if (reg->size)
784 		return serial_port_in(port, SCTFDR) & fifo_mask;
785 
786 	reg = sci_getreg(port, SCFDR);
787 	if (reg->size)
788 		return serial_port_in(port, SCFDR) >> 8;
789 
790 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
791 }
792 
793 static int sci_txroom(struct uart_port *port)
794 {
795 	return port->fifosize - sci_txfill(port);
796 }
797 
798 static int sci_rxfill(struct uart_port *port)
799 {
800 	struct sci_port *s = to_sci_port(port);
801 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
802 	const struct plat_sci_reg *reg;
803 
804 	reg = sci_getreg(port, SCRFDR);
805 	if (reg->size)
806 		return serial_port_in(port, SCRFDR) & fifo_mask;
807 
808 	reg = sci_getreg(port, SCFDR);
809 	if (reg->size)
810 		return serial_port_in(port, SCFDR) & fifo_mask;
811 
812 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
813 }
814 
815 /* ********************************************************************** *
816  *                   the interrupt related routines                       *
817  * ********************************************************************** */
818 
819 static void sci_transmit_chars(struct uart_port *port)
820 {
821 	struct circ_buf *xmit = &port->state->xmit;
822 	unsigned int stopped = uart_tx_stopped(port);
823 	unsigned short status;
824 	unsigned short ctrl;
825 	int count;
826 
827 	status = serial_port_in(port, SCxSR);
828 	if (!(status & SCxSR_TDxE(port))) {
829 		ctrl = serial_port_in(port, SCSCR);
830 		if (uart_circ_empty(xmit))
831 			ctrl &= ~SCSCR_TIE;
832 		else
833 			ctrl |= SCSCR_TIE;
834 		serial_port_out(port, SCSCR, ctrl);
835 		return;
836 	}
837 
838 	count = sci_txroom(port);
839 
840 	do {
841 		unsigned char c;
842 
843 		if (port->x_char) {
844 			c = port->x_char;
845 			port->x_char = 0;
846 		} else if (!uart_circ_empty(xmit) && !stopped) {
847 			c = xmit->buf[xmit->tail];
848 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
849 		} else if (port->type == PORT_SCI && uart_circ_empty(xmit)) {
850 			ctrl = serial_port_in(port, SCSCR);
851 			ctrl &= ~SCSCR_TE;
852 			serial_port_out(port, SCSCR, ctrl);
853 			return;
854 		} else {
855 			break;
856 		}
857 
858 		serial_port_out(port, SCxTDR, c);
859 
860 		port->icount.tx++;
861 	} while (--count > 0);
862 
863 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
864 
865 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
866 		uart_write_wakeup(port);
867 	if (uart_circ_empty(xmit)) {
868 		if (port->type == PORT_SCI) {
869 			ctrl = serial_port_in(port, SCSCR);
870 			ctrl &= ~SCSCR_TIE;
871 			ctrl |= SCSCR_TEIE;
872 			serial_port_out(port, SCSCR, ctrl);
873 		}
874 
875 		sci_stop_tx(port);
876 	}
877 }
878 
879 static void sci_receive_chars(struct uart_port *port)
880 {
881 	struct tty_port *tport = &port->state->port;
882 	int i, count, copied = 0;
883 	unsigned short status;
884 	unsigned char flag;
885 
886 	status = serial_port_in(port, SCxSR);
887 	if (!(status & SCxSR_RDxF(port)))
888 		return;
889 
890 	while (1) {
891 		/* Don't copy more bytes than there is room for in the buffer */
892 		count = tty_buffer_request_room(tport, sci_rxfill(port));
893 
894 		/* If for any reason we can't copy more data, we're done! */
895 		if (count == 0)
896 			break;
897 
898 		if (port->type == PORT_SCI) {
899 			char c = serial_port_in(port, SCxRDR);
900 			if (uart_handle_sysrq_char(port, c))
901 				count = 0;
902 			else
903 				tty_insert_flip_char(tport, c, TTY_NORMAL);
904 		} else {
905 			for (i = 0; i < count; i++) {
906 				char c;
907 
908 				if (port->type == PORT_SCIF ||
909 				    port->type == PORT_HSCIF) {
910 					status = serial_port_in(port, SCxSR);
911 					c = serial_port_in(port, SCxRDR);
912 				} else {
913 					c = serial_port_in(port, SCxRDR);
914 					status = serial_port_in(port, SCxSR);
915 				}
916 				if (uart_handle_sysrq_char(port, c)) {
917 					count--; i--;
918 					continue;
919 				}
920 
921 				/* Store data and status */
922 				if (status & SCxSR_FER(port)) {
923 					flag = TTY_FRAME;
924 					port->icount.frame++;
925 				} else if (status & SCxSR_PER(port)) {
926 					flag = TTY_PARITY;
927 					port->icount.parity++;
928 				} else
929 					flag = TTY_NORMAL;
930 
931 				tty_insert_flip_char(tport, c, flag);
932 			}
933 		}
934 
935 		serial_port_in(port, SCxSR); /* dummy read */
936 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
937 
938 		copied += count;
939 		port->icount.rx += count;
940 	}
941 
942 	if (copied) {
943 		/* Tell the rest of the system the news. New characters! */
944 		tty_flip_buffer_push(tport);
945 	} else {
946 		/* TTY buffers full; read from RX reg to prevent lockup */
947 		serial_port_in(port, SCxRDR);
948 		serial_port_in(port, SCxSR); /* dummy read */
949 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
950 	}
951 }
952 
953 static int sci_handle_errors(struct uart_port *port)
954 {
955 	int copied = 0;
956 	unsigned short status = serial_port_in(port, SCxSR);
957 	struct tty_port *tport = &port->state->port;
958 	struct sci_port *s = to_sci_port(port);
959 
960 	/* Handle overruns */
961 	if (status & s->params->overrun_mask) {
962 		port->icount.overrun++;
963 
964 		/* overrun error */
965 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
966 			copied++;
967 	}
968 
969 	if (status & SCxSR_FER(port)) {
970 		/* frame error */
971 		port->icount.frame++;
972 
973 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
974 			copied++;
975 	}
976 
977 	if (status & SCxSR_PER(port)) {
978 		/* parity error */
979 		port->icount.parity++;
980 
981 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
982 			copied++;
983 	}
984 
985 	if (copied)
986 		tty_flip_buffer_push(tport);
987 
988 	return copied;
989 }
990 
991 static int sci_handle_fifo_overrun(struct uart_port *port)
992 {
993 	struct tty_port *tport = &port->state->port;
994 	struct sci_port *s = to_sci_port(port);
995 	const struct plat_sci_reg *reg;
996 	int copied = 0;
997 	u16 status;
998 
999 	reg = sci_getreg(port, s->params->overrun_reg);
1000 	if (!reg->size)
1001 		return 0;
1002 
1003 	status = serial_port_in(port, s->params->overrun_reg);
1004 	if (status & s->params->overrun_mask) {
1005 		status &= ~s->params->overrun_mask;
1006 		serial_port_out(port, s->params->overrun_reg, status);
1007 
1008 		port->icount.overrun++;
1009 
1010 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1011 		tty_flip_buffer_push(tport);
1012 		copied++;
1013 	}
1014 
1015 	return copied;
1016 }
1017 
1018 static int sci_handle_breaks(struct uart_port *port)
1019 {
1020 	int copied = 0;
1021 	unsigned short status = serial_port_in(port, SCxSR);
1022 	struct tty_port *tport = &port->state->port;
1023 
1024 	if (uart_handle_break(port))
1025 		return 0;
1026 
1027 	if (status & SCxSR_BRK(port)) {
1028 		port->icount.brk++;
1029 
1030 		/* Notify of BREAK */
1031 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1032 			copied++;
1033 	}
1034 
1035 	if (copied)
1036 		tty_flip_buffer_push(tport);
1037 
1038 	copied += sci_handle_fifo_overrun(port);
1039 
1040 	return copied;
1041 }
1042 
1043 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1044 {
1045 	unsigned int bits;
1046 
1047 	if (rx_trig >= port->fifosize)
1048 		rx_trig = port->fifosize - 1;
1049 	if (rx_trig < 1)
1050 		rx_trig = 1;
1051 
1052 	/* HSCIF can be set to an arbitrary level. */
1053 	if (sci_getreg(port, HSRTRGR)->size) {
1054 		serial_port_out(port, HSRTRGR, rx_trig);
1055 		return rx_trig;
1056 	}
1057 
1058 	switch (port->type) {
1059 	case PORT_SCIF:
1060 		if (rx_trig < 4) {
1061 			bits = 0;
1062 			rx_trig = 1;
1063 		} else if (rx_trig < 8) {
1064 			bits = SCFCR_RTRG0;
1065 			rx_trig = 4;
1066 		} else if (rx_trig < 14) {
1067 			bits = SCFCR_RTRG1;
1068 			rx_trig = 8;
1069 		} else {
1070 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1071 			rx_trig = 14;
1072 		}
1073 		break;
1074 	case PORT_SCIFA:
1075 	case PORT_SCIFB:
1076 		if (rx_trig < 16) {
1077 			bits = 0;
1078 			rx_trig = 1;
1079 		} else if (rx_trig < 32) {
1080 			bits = SCFCR_RTRG0;
1081 			rx_trig = 16;
1082 		} else if (rx_trig < 48) {
1083 			bits = SCFCR_RTRG1;
1084 			rx_trig = 32;
1085 		} else {
1086 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1087 			rx_trig = 48;
1088 		}
1089 		break;
1090 	default:
1091 		WARN(1, "unknown FIFO configuration");
1092 		return 1;
1093 	}
1094 
1095 	serial_port_out(port, SCFCR,
1096 		(serial_port_in(port, SCFCR) &
1097 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1098 
1099 	return rx_trig;
1100 }
1101 
1102 static int scif_rtrg_enabled(struct uart_port *port)
1103 {
1104 	if (sci_getreg(port, HSRTRGR)->size)
1105 		return serial_port_in(port, HSRTRGR) != 0;
1106 	else
1107 		return (serial_port_in(port, SCFCR) &
1108 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1109 }
1110 
1111 static void rx_fifo_timer_fn(struct timer_list *t)
1112 {
1113 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1114 	struct uart_port *port = &s->port;
1115 
1116 	dev_dbg(port->dev, "Rx timed out\n");
1117 	scif_set_rtrg(port, 1);
1118 }
1119 
1120 static ssize_t rx_fifo_trigger_show(struct device *dev,
1121 				    struct device_attribute *attr, char *buf)
1122 {
1123 	struct uart_port *port = dev_get_drvdata(dev);
1124 	struct sci_port *sci = to_sci_port(port);
1125 
1126 	return sprintf(buf, "%d\n", sci->rx_trigger);
1127 }
1128 
1129 static ssize_t rx_fifo_trigger_store(struct device *dev,
1130 				     struct device_attribute *attr,
1131 				     const char *buf, size_t count)
1132 {
1133 	struct uart_port *port = dev_get_drvdata(dev);
1134 	struct sci_port *sci = to_sci_port(port);
1135 	int ret;
1136 	long r;
1137 
1138 	ret = kstrtol(buf, 0, &r);
1139 	if (ret)
1140 		return ret;
1141 
1142 	sci->rx_trigger = scif_set_rtrg(port, r);
1143 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1144 		scif_set_rtrg(port, 1);
1145 
1146 	return count;
1147 }
1148 
1149 static DEVICE_ATTR_RW(rx_fifo_trigger);
1150 
1151 static ssize_t rx_fifo_timeout_show(struct device *dev,
1152 			       struct device_attribute *attr,
1153 			       char *buf)
1154 {
1155 	struct uart_port *port = dev_get_drvdata(dev);
1156 	struct sci_port *sci = to_sci_port(port);
1157 	int v;
1158 
1159 	if (port->type == PORT_HSCIF)
1160 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1161 	else
1162 		v = sci->rx_fifo_timeout;
1163 
1164 	return sprintf(buf, "%d\n", v);
1165 }
1166 
1167 static ssize_t rx_fifo_timeout_store(struct device *dev,
1168 				struct device_attribute *attr,
1169 				const char *buf,
1170 				size_t count)
1171 {
1172 	struct uart_port *port = dev_get_drvdata(dev);
1173 	struct sci_port *sci = to_sci_port(port);
1174 	int ret;
1175 	long r;
1176 
1177 	ret = kstrtol(buf, 0, &r);
1178 	if (ret)
1179 		return ret;
1180 
1181 	if (port->type == PORT_HSCIF) {
1182 		if (r < 0 || r > 3)
1183 			return -EINVAL;
1184 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1185 	} else {
1186 		sci->rx_fifo_timeout = r;
1187 		scif_set_rtrg(port, 1);
1188 		if (r > 0)
1189 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1190 	}
1191 
1192 	return count;
1193 }
1194 
1195 static DEVICE_ATTR_RW(rx_fifo_timeout);
1196 
1197 
1198 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1199 static void sci_dma_tx_complete(void *arg)
1200 {
1201 	struct sci_port *s = arg;
1202 	struct uart_port *port = &s->port;
1203 	struct circ_buf *xmit = &port->state->xmit;
1204 	unsigned long flags;
1205 
1206 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1207 
1208 	spin_lock_irqsave(&port->lock, flags);
1209 
1210 	uart_xmit_advance(port, s->tx_dma_len);
1211 
1212 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1213 		uart_write_wakeup(port);
1214 
1215 	if (!uart_circ_empty(xmit)) {
1216 		s->cookie_tx = 0;
1217 		schedule_work(&s->work_tx);
1218 	} else {
1219 		s->cookie_tx = -EINVAL;
1220 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1221 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1222 			u16 ctrl = serial_port_in(port, SCSCR);
1223 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1224 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1225 				/* Switch irq from DMA to SCIF */
1226 				dmaengine_pause(s->chan_tx_saved);
1227 				enable_irq(s->irqs[SCIx_TXI_IRQ]);
1228 			}
1229 		}
1230 	}
1231 
1232 	spin_unlock_irqrestore(&port->lock, flags);
1233 }
1234 
1235 /* Locking: called with port lock held */
1236 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1237 {
1238 	struct uart_port *port = &s->port;
1239 	struct tty_port *tport = &port->state->port;
1240 	int copied;
1241 
1242 	copied = tty_insert_flip_string(tport, buf, count);
1243 	if (copied < count)
1244 		port->icount.buf_overrun++;
1245 
1246 	port->icount.rx += copied;
1247 
1248 	return copied;
1249 }
1250 
1251 static int sci_dma_rx_find_active(struct sci_port *s)
1252 {
1253 	unsigned int i;
1254 
1255 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1256 		if (s->active_rx == s->cookie_rx[i])
1257 			return i;
1258 
1259 	return -1;
1260 }
1261 
1262 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1263 {
1264 	unsigned int i;
1265 
1266 	s->chan_rx = NULL;
1267 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1268 		s->cookie_rx[i] = -EINVAL;
1269 	s->active_rx = 0;
1270 }
1271 
1272 static void sci_dma_rx_release(struct sci_port *s)
1273 {
1274 	struct dma_chan *chan = s->chan_rx_saved;
1275 
1276 	s->chan_rx_saved = NULL;
1277 	sci_dma_rx_chan_invalidate(s);
1278 	dmaengine_terminate_sync(chan);
1279 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1280 			  sg_dma_address(&s->sg_rx[0]));
1281 	dma_release_channel(chan);
1282 }
1283 
1284 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1285 {
1286 	long sec = usec / 1000000;
1287 	long nsec = (usec % 1000000) * 1000;
1288 	ktime_t t = ktime_set(sec, nsec);
1289 
1290 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1291 }
1292 
1293 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1294 {
1295 	struct uart_port *port = &s->port;
1296 	u16 scr;
1297 
1298 	/* Direct new serial port interrupts back to CPU */
1299 	scr = serial_port_in(port, SCSCR);
1300 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1301 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1302 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1303 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1304 			scif_set_rtrg(port, s->rx_trigger);
1305 		else
1306 			scr &= ~SCSCR_RDRQE;
1307 	}
1308 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1309 }
1310 
1311 static void sci_dma_rx_complete(void *arg)
1312 {
1313 	struct sci_port *s = arg;
1314 	struct dma_chan *chan = s->chan_rx;
1315 	struct uart_port *port = &s->port;
1316 	struct dma_async_tx_descriptor *desc;
1317 	unsigned long flags;
1318 	int active, count = 0;
1319 
1320 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1321 		s->active_rx);
1322 
1323 	spin_lock_irqsave(&port->lock, flags);
1324 
1325 	active = sci_dma_rx_find_active(s);
1326 	if (active >= 0)
1327 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1328 
1329 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1330 
1331 	if (count)
1332 		tty_flip_buffer_push(&port->state->port);
1333 
1334 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1335 				       DMA_DEV_TO_MEM,
1336 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1337 	if (!desc)
1338 		goto fail;
1339 
1340 	desc->callback = sci_dma_rx_complete;
1341 	desc->callback_param = s;
1342 	s->cookie_rx[active] = dmaengine_submit(desc);
1343 	if (dma_submit_error(s->cookie_rx[active]))
1344 		goto fail;
1345 
1346 	s->active_rx = s->cookie_rx[!active];
1347 
1348 	dma_async_issue_pending(chan);
1349 
1350 	spin_unlock_irqrestore(&port->lock, flags);
1351 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1352 		__func__, s->cookie_rx[active], active, s->active_rx);
1353 	return;
1354 
1355 fail:
1356 	spin_unlock_irqrestore(&port->lock, flags);
1357 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1358 	/* Switch to PIO */
1359 	spin_lock_irqsave(&port->lock, flags);
1360 	dmaengine_terminate_async(chan);
1361 	sci_dma_rx_chan_invalidate(s);
1362 	sci_dma_rx_reenable_irq(s);
1363 	spin_unlock_irqrestore(&port->lock, flags);
1364 }
1365 
1366 static void sci_dma_tx_release(struct sci_port *s)
1367 {
1368 	struct dma_chan *chan = s->chan_tx_saved;
1369 
1370 	cancel_work_sync(&s->work_tx);
1371 	s->chan_tx_saved = s->chan_tx = NULL;
1372 	s->cookie_tx = -EINVAL;
1373 	dmaengine_terminate_sync(chan);
1374 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1375 			 DMA_TO_DEVICE);
1376 	dma_release_channel(chan);
1377 }
1378 
1379 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1380 {
1381 	struct dma_chan *chan = s->chan_rx;
1382 	struct uart_port *port = &s->port;
1383 	unsigned long flags;
1384 	int i;
1385 
1386 	for (i = 0; i < 2; i++) {
1387 		struct scatterlist *sg = &s->sg_rx[i];
1388 		struct dma_async_tx_descriptor *desc;
1389 
1390 		desc = dmaengine_prep_slave_sg(chan,
1391 			sg, 1, DMA_DEV_TO_MEM,
1392 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1393 		if (!desc)
1394 			goto fail;
1395 
1396 		desc->callback = sci_dma_rx_complete;
1397 		desc->callback_param = s;
1398 		s->cookie_rx[i] = dmaengine_submit(desc);
1399 		if (dma_submit_error(s->cookie_rx[i]))
1400 			goto fail;
1401 
1402 	}
1403 
1404 	s->active_rx = s->cookie_rx[0];
1405 
1406 	dma_async_issue_pending(chan);
1407 	return 0;
1408 
1409 fail:
1410 	/* Switch to PIO */
1411 	if (!port_lock_held)
1412 		spin_lock_irqsave(&port->lock, flags);
1413 	if (i)
1414 		dmaengine_terminate_async(chan);
1415 	sci_dma_rx_chan_invalidate(s);
1416 	sci_start_rx(port);
1417 	if (!port_lock_held)
1418 		spin_unlock_irqrestore(&port->lock, flags);
1419 	return -EAGAIN;
1420 }
1421 
1422 static void sci_dma_tx_work_fn(struct work_struct *work)
1423 {
1424 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1425 	struct dma_async_tx_descriptor *desc;
1426 	struct dma_chan *chan = s->chan_tx;
1427 	struct uart_port *port = &s->port;
1428 	struct circ_buf *xmit = &port->state->xmit;
1429 	unsigned long flags;
1430 	dma_addr_t buf;
1431 	int head, tail;
1432 
1433 	/*
1434 	 * DMA is idle now.
1435 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1436 	 * offsets and lengths. Since it is a circular buffer, we have to
1437 	 * transmit till the end, and then the rest. Take the port lock to get a
1438 	 * consistent xmit buffer state.
1439 	 */
1440 	spin_lock_irq(&port->lock);
1441 	head = xmit->head;
1442 	tail = xmit->tail;
1443 	buf = s->tx_dma_addr + tail;
1444 	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
1445 	if (!s->tx_dma_len) {
1446 		/* Transmit buffer has been flushed */
1447 		spin_unlock_irq(&port->lock);
1448 		return;
1449 	}
1450 
1451 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1452 					   DMA_MEM_TO_DEV,
1453 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1454 	if (!desc) {
1455 		spin_unlock_irq(&port->lock);
1456 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1457 		goto switch_to_pio;
1458 	}
1459 
1460 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1461 				   DMA_TO_DEVICE);
1462 
1463 	desc->callback = sci_dma_tx_complete;
1464 	desc->callback_param = s;
1465 	s->cookie_tx = dmaengine_submit(desc);
1466 	if (dma_submit_error(s->cookie_tx)) {
1467 		spin_unlock_irq(&port->lock);
1468 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1469 		goto switch_to_pio;
1470 	}
1471 
1472 	spin_unlock_irq(&port->lock);
1473 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1474 		__func__, xmit->buf, tail, head, s->cookie_tx);
1475 
1476 	dma_async_issue_pending(chan);
1477 	return;
1478 
1479 switch_to_pio:
1480 	spin_lock_irqsave(&port->lock, flags);
1481 	s->chan_tx = NULL;
1482 	sci_start_tx(port);
1483 	spin_unlock_irqrestore(&port->lock, flags);
1484 	return;
1485 }
1486 
1487 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1488 {
1489 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1490 	struct dma_chan *chan = s->chan_rx;
1491 	struct uart_port *port = &s->port;
1492 	struct dma_tx_state state;
1493 	enum dma_status status;
1494 	unsigned long flags;
1495 	unsigned int read;
1496 	int active, count;
1497 
1498 	dev_dbg(port->dev, "DMA Rx timed out\n");
1499 
1500 	spin_lock_irqsave(&port->lock, flags);
1501 
1502 	active = sci_dma_rx_find_active(s);
1503 	if (active < 0) {
1504 		spin_unlock_irqrestore(&port->lock, flags);
1505 		return HRTIMER_NORESTART;
1506 	}
1507 
1508 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1509 	if (status == DMA_COMPLETE) {
1510 		spin_unlock_irqrestore(&port->lock, flags);
1511 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1512 			s->active_rx, active);
1513 
1514 		/* Let packet complete handler take care of the packet */
1515 		return HRTIMER_NORESTART;
1516 	}
1517 
1518 	dmaengine_pause(chan);
1519 
1520 	/*
1521 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1522 	 * data keeps on coming until transaction is complete so check
1523 	 * for DMA_COMPLETE again
1524 	 * Let packet complete handler take care of the packet
1525 	 */
1526 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1527 	if (status == DMA_COMPLETE) {
1528 		spin_unlock_irqrestore(&port->lock, flags);
1529 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1530 		return HRTIMER_NORESTART;
1531 	}
1532 
1533 	/* Handle incomplete DMA receive */
1534 	dmaengine_terminate_async(s->chan_rx);
1535 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1536 
1537 	if (read) {
1538 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1539 		if (count)
1540 			tty_flip_buffer_push(&port->state->port);
1541 	}
1542 
1543 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1544 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1545 		sci_dma_rx_submit(s, true);
1546 
1547 	sci_dma_rx_reenable_irq(s);
1548 
1549 	spin_unlock_irqrestore(&port->lock, flags);
1550 
1551 	return HRTIMER_NORESTART;
1552 }
1553 
1554 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1555 					     enum dma_transfer_direction dir)
1556 {
1557 	struct dma_chan *chan;
1558 	struct dma_slave_config cfg;
1559 	int ret;
1560 
1561 	chan = dma_request_slave_channel(port->dev,
1562 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1563 	if (!chan) {
1564 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1565 		return NULL;
1566 	}
1567 
1568 	memset(&cfg, 0, sizeof(cfg));
1569 	cfg.direction = dir;
1570 	cfg.dst_addr = port->mapbase +
1571 		(sci_getreg(port, SCxTDR)->offset << port->regshift);
1572 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1573 	cfg.src_addr = port->mapbase +
1574 		(sci_getreg(port, SCxRDR)->offset << port->regshift);
1575 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1576 
1577 	ret = dmaengine_slave_config(chan, &cfg);
1578 	if (ret) {
1579 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1580 		dma_release_channel(chan);
1581 		return NULL;
1582 	}
1583 
1584 	return chan;
1585 }
1586 
1587 static void sci_request_dma(struct uart_port *port)
1588 {
1589 	struct sci_port *s = to_sci_port(port);
1590 	struct dma_chan *chan;
1591 
1592 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1593 
1594 	/*
1595 	 * DMA on console may interfere with Kernel log messages which use
1596 	 * plain putchar(). So, simply don't use it with a console.
1597 	 */
1598 	if (uart_console(port))
1599 		return;
1600 
1601 	if (!port->dev->of_node)
1602 		return;
1603 
1604 	s->cookie_tx = -EINVAL;
1605 
1606 	/*
1607 	 * Don't request a dma channel if no channel was specified
1608 	 * in the device tree.
1609 	 */
1610 	if (!of_property_present(port->dev->of_node, "dmas"))
1611 		return;
1612 
1613 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1614 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1615 	if (chan) {
1616 		/* UART circular tx buffer is an aligned page. */
1617 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1618 						port->state->xmit.buf,
1619 						UART_XMIT_SIZE,
1620 						DMA_TO_DEVICE);
1621 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1622 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1623 			dma_release_channel(chan);
1624 		} else {
1625 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1626 				__func__, UART_XMIT_SIZE,
1627 				port->state->xmit.buf, &s->tx_dma_addr);
1628 
1629 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1630 			s->chan_tx_saved = s->chan_tx = chan;
1631 		}
1632 	}
1633 
1634 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1635 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1636 	if (chan) {
1637 		unsigned int i;
1638 		dma_addr_t dma;
1639 		void *buf;
1640 
1641 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1642 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1643 					 &dma, GFP_KERNEL);
1644 		if (!buf) {
1645 			dev_warn(port->dev,
1646 				 "Failed to allocate Rx dma buffer, using PIO\n");
1647 			dma_release_channel(chan);
1648 			return;
1649 		}
1650 
1651 		for (i = 0; i < 2; i++) {
1652 			struct scatterlist *sg = &s->sg_rx[i];
1653 
1654 			sg_init_table(sg, 1);
1655 			s->rx_buf[i] = buf;
1656 			sg_dma_address(sg) = dma;
1657 			sg_dma_len(sg) = s->buf_len_rx;
1658 
1659 			buf += s->buf_len_rx;
1660 			dma += s->buf_len_rx;
1661 		}
1662 
1663 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1664 		s->rx_timer.function = sci_dma_rx_timer_fn;
1665 
1666 		s->chan_rx_saved = s->chan_rx = chan;
1667 
1668 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1669 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1670 			sci_dma_rx_submit(s, false);
1671 	}
1672 }
1673 
1674 static void sci_free_dma(struct uart_port *port)
1675 {
1676 	struct sci_port *s = to_sci_port(port);
1677 
1678 	if (s->chan_tx_saved)
1679 		sci_dma_tx_release(s);
1680 	if (s->chan_rx_saved)
1681 		sci_dma_rx_release(s);
1682 }
1683 
1684 static void sci_flush_buffer(struct uart_port *port)
1685 {
1686 	struct sci_port *s = to_sci_port(port);
1687 
1688 	/*
1689 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1690 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1691 	 * pending transfers
1692 	 */
1693 	s->tx_dma_len = 0;
1694 	if (s->chan_tx) {
1695 		dmaengine_terminate_async(s->chan_tx);
1696 		s->cookie_tx = -EINVAL;
1697 	}
1698 }
1699 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1700 static inline void sci_request_dma(struct uart_port *port)
1701 {
1702 }
1703 
1704 static inline void sci_free_dma(struct uart_port *port)
1705 {
1706 }
1707 
1708 #define sci_flush_buffer	NULL
1709 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1710 
1711 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1712 {
1713 	struct uart_port *port = ptr;
1714 	struct sci_port *s = to_sci_port(port);
1715 
1716 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1717 	if (s->chan_rx) {
1718 		u16 scr = serial_port_in(port, SCSCR);
1719 		u16 ssr = serial_port_in(port, SCxSR);
1720 
1721 		/* Disable future Rx interrupts */
1722 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1723 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1724 			disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
1725 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1726 				scif_set_rtrg(port, 1);
1727 				scr |= SCSCR_RIE;
1728 			} else {
1729 				scr |= SCSCR_RDRQE;
1730 			}
1731 		} else {
1732 			if (sci_dma_rx_submit(s, false) < 0)
1733 				goto handle_pio;
1734 
1735 			scr &= ~SCSCR_RIE;
1736 		}
1737 		serial_port_out(port, SCSCR, scr);
1738 		/* Clear current interrupt */
1739 		serial_port_out(port, SCxSR,
1740 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1741 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1742 			jiffies, s->rx_timeout);
1743 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1744 
1745 		return IRQ_HANDLED;
1746 	}
1747 
1748 handle_pio:
1749 #endif
1750 
1751 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1752 		if (!scif_rtrg_enabled(port))
1753 			scif_set_rtrg(port, s->rx_trigger);
1754 
1755 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1756 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1757 	}
1758 
1759 	/* I think sci_receive_chars has to be called irrespective
1760 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1761 	 * to be disabled?
1762 	 */
1763 	sci_receive_chars(port);
1764 
1765 	return IRQ_HANDLED;
1766 }
1767 
1768 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1769 {
1770 	struct uart_port *port = ptr;
1771 	unsigned long flags;
1772 
1773 	spin_lock_irqsave(&port->lock, flags);
1774 	sci_transmit_chars(port);
1775 	spin_unlock_irqrestore(&port->lock, flags);
1776 
1777 	return IRQ_HANDLED;
1778 }
1779 
1780 static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
1781 {
1782 	struct uart_port *port = ptr;
1783 	unsigned long flags;
1784 	unsigned short ctrl;
1785 
1786 	if (port->type != PORT_SCI)
1787 		return sci_tx_interrupt(irq, ptr);
1788 
1789 	spin_lock_irqsave(&port->lock, flags);
1790 	ctrl = serial_port_in(port, SCSCR);
1791 	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
1792 	serial_port_out(port, SCSCR, ctrl);
1793 	spin_unlock_irqrestore(&port->lock, flags);
1794 
1795 	return IRQ_HANDLED;
1796 }
1797 
1798 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1799 {
1800 	struct uart_port *port = ptr;
1801 
1802 	/* Handle BREAKs */
1803 	sci_handle_breaks(port);
1804 
1805 	/* drop invalid character received before break was detected */
1806 	serial_port_in(port, SCxRDR);
1807 
1808 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1809 
1810 	return IRQ_HANDLED;
1811 }
1812 
1813 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1814 {
1815 	struct uart_port *port = ptr;
1816 	struct sci_port *s = to_sci_port(port);
1817 
1818 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1819 		/* Break and Error interrupts are muxed */
1820 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1821 
1822 		/* Break Interrupt */
1823 		if (ssr_status & SCxSR_BRK(port))
1824 			sci_br_interrupt(irq, ptr);
1825 
1826 		/* Break only? */
1827 		if (!(ssr_status & SCxSR_ERRORS(port)))
1828 			return IRQ_HANDLED;
1829 	}
1830 
1831 	/* Handle errors */
1832 	if (port->type == PORT_SCI) {
1833 		if (sci_handle_errors(port)) {
1834 			/* discard character in rx buffer */
1835 			serial_port_in(port, SCxSR);
1836 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1837 		}
1838 	} else {
1839 		sci_handle_fifo_overrun(port);
1840 		if (!s->chan_rx)
1841 			sci_receive_chars(port);
1842 	}
1843 
1844 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1845 
1846 	/* Kick the transmission */
1847 	if (!s->chan_tx)
1848 		sci_tx_interrupt(irq, ptr);
1849 
1850 	return IRQ_HANDLED;
1851 }
1852 
1853 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1854 {
1855 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1856 	struct uart_port *port = ptr;
1857 	struct sci_port *s = to_sci_port(port);
1858 	irqreturn_t ret = IRQ_NONE;
1859 
1860 	ssr_status = serial_port_in(port, SCxSR);
1861 	scr_status = serial_port_in(port, SCSCR);
1862 	if (s->params->overrun_reg == SCxSR)
1863 		orer_status = ssr_status;
1864 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1865 		orer_status = serial_port_in(port, s->params->overrun_reg);
1866 
1867 	err_enabled = scr_status & port_rx_irq_mask(port);
1868 
1869 	/* Tx Interrupt */
1870 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1871 	    !s->chan_tx)
1872 		ret = sci_tx_interrupt(irq, ptr);
1873 
1874 	/*
1875 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1876 	 * DR flags
1877 	 */
1878 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1879 	    (scr_status & SCSCR_RIE))
1880 		ret = sci_rx_interrupt(irq, ptr);
1881 
1882 	/* Error Interrupt */
1883 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1884 		ret = sci_er_interrupt(irq, ptr);
1885 
1886 	/* Break Interrupt */
1887 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1888 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1889 		ret = sci_br_interrupt(irq, ptr);
1890 
1891 	/* Overrun Interrupt */
1892 	if (orer_status & s->params->overrun_mask) {
1893 		sci_handle_fifo_overrun(port);
1894 		ret = IRQ_HANDLED;
1895 	}
1896 
1897 	return ret;
1898 }
1899 
1900 static const struct sci_irq_desc {
1901 	const char	*desc;
1902 	irq_handler_t	handler;
1903 } sci_irq_desc[] = {
1904 	/*
1905 	 * Split out handlers, the default case.
1906 	 */
1907 	[SCIx_ERI_IRQ] = {
1908 		.desc = "rx err",
1909 		.handler = sci_er_interrupt,
1910 	},
1911 
1912 	[SCIx_RXI_IRQ] = {
1913 		.desc = "rx full",
1914 		.handler = sci_rx_interrupt,
1915 	},
1916 
1917 	[SCIx_TXI_IRQ] = {
1918 		.desc = "tx empty",
1919 		.handler = sci_tx_interrupt,
1920 	},
1921 
1922 	[SCIx_BRI_IRQ] = {
1923 		.desc = "break",
1924 		.handler = sci_br_interrupt,
1925 	},
1926 
1927 	[SCIx_DRI_IRQ] = {
1928 		.desc = "rx ready",
1929 		.handler = sci_rx_interrupt,
1930 	},
1931 
1932 	[SCIx_TEI_IRQ] = {
1933 		.desc = "tx end",
1934 		.handler = sci_tx_end_interrupt,
1935 	},
1936 
1937 	/*
1938 	 * Special muxed handler.
1939 	 */
1940 	[SCIx_MUX_IRQ] = {
1941 		.desc = "mux",
1942 		.handler = sci_mpxed_interrupt,
1943 	},
1944 };
1945 
1946 static int sci_request_irq(struct sci_port *port)
1947 {
1948 	struct uart_port *up = &port->port;
1949 	int i, j, w, ret = 0;
1950 
1951 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1952 		const struct sci_irq_desc *desc;
1953 		int irq;
1954 
1955 		/* Check if already registered (muxed) */
1956 		for (w = 0; w < i; w++)
1957 			if (port->irqs[w] == port->irqs[i])
1958 				w = i + 1;
1959 		if (w > i)
1960 			continue;
1961 
1962 		if (SCIx_IRQ_IS_MUXED(port)) {
1963 			i = SCIx_MUX_IRQ;
1964 			irq = up->irq;
1965 		} else {
1966 			irq = port->irqs[i];
1967 
1968 			/*
1969 			 * Certain port types won't support all of the
1970 			 * available interrupt sources.
1971 			 */
1972 			if (unlikely(irq < 0))
1973 				continue;
1974 		}
1975 
1976 		desc = sci_irq_desc + i;
1977 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1978 					    dev_name(up->dev), desc->desc);
1979 		if (!port->irqstr[j]) {
1980 			ret = -ENOMEM;
1981 			goto out_nomem;
1982 		}
1983 
1984 		ret = request_irq(irq, desc->handler, up->irqflags,
1985 				  port->irqstr[j], port);
1986 		if (unlikely(ret)) {
1987 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1988 			goto out_noirq;
1989 		}
1990 	}
1991 
1992 	return 0;
1993 
1994 out_noirq:
1995 	while (--i >= 0)
1996 		free_irq(port->irqs[i], port);
1997 
1998 out_nomem:
1999 	while (--j >= 0)
2000 		kfree(port->irqstr[j]);
2001 
2002 	return ret;
2003 }
2004 
2005 static void sci_free_irq(struct sci_port *port)
2006 {
2007 	int i, j;
2008 
2009 	/*
2010 	 * Intentionally in reverse order so we iterate over the muxed
2011 	 * IRQ first.
2012 	 */
2013 	for (i = 0; i < SCIx_NR_IRQS; i++) {
2014 		int irq = port->irqs[i];
2015 
2016 		/*
2017 		 * Certain port types won't support all of the available
2018 		 * interrupt sources.
2019 		 */
2020 		if (unlikely(irq < 0))
2021 			continue;
2022 
2023 		/* Check if already freed (irq was muxed) */
2024 		for (j = 0; j < i; j++)
2025 			if (port->irqs[j] == irq)
2026 				j = i + 1;
2027 		if (j > i)
2028 			continue;
2029 
2030 		free_irq(port->irqs[i], port);
2031 		kfree(port->irqstr[i]);
2032 
2033 		if (SCIx_IRQ_IS_MUXED(port)) {
2034 			/* If there's only one IRQ, we're done. */
2035 			return;
2036 		}
2037 	}
2038 }
2039 
2040 static unsigned int sci_tx_empty(struct uart_port *port)
2041 {
2042 	unsigned short status = serial_port_in(port, SCxSR);
2043 	unsigned short in_tx_fifo = sci_txfill(port);
2044 
2045 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2046 }
2047 
2048 static void sci_set_rts(struct uart_port *port, bool state)
2049 {
2050 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2051 		u16 data = serial_port_in(port, SCPDR);
2052 
2053 		/* Active low */
2054 		if (state)
2055 			data &= ~SCPDR_RTSD;
2056 		else
2057 			data |= SCPDR_RTSD;
2058 		serial_port_out(port, SCPDR, data);
2059 
2060 		/* RTS# is output */
2061 		serial_port_out(port, SCPCR,
2062 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2063 	} else if (sci_getreg(port, SCSPTR)->size) {
2064 		u16 ctrl = serial_port_in(port, SCSPTR);
2065 
2066 		/* Active low */
2067 		if (state)
2068 			ctrl &= ~SCSPTR_RTSDT;
2069 		else
2070 			ctrl |= SCSPTR_RTSDT;
2071 		serial_port_out(port, SCSPTR, ctrl);
2072 	}
2073 }
2074 
2075 static bool sci_get_cts(struct uart_port *port)
2076 {
2077 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2078 		/* Active low */
2079 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2080 	} else if (sci_getreg(port, SCSPTR)->size) {
2081 		/* Active low */
2082 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2083 	}
2084 
2085 	return true;
2086 }
2087 
2088 /*
2089  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2090  * CTS/RTS is supported in hardware by at least one port and controlled
2091  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2092  * handled via the ->init_pins() op, which is a bit of a one-way street,
2093  * lacking any ability to defer pin control -- this will later be
2094  * converted over to the GPIO framework).
2095  *
2096  * Other modes (such as loopback) are supported generically on certain
2097  * port types, but not others. For these it's sufficient to test for the
2098  * existence of the support register and simply ignore the port type.
2099  */
2100 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2101 {
2102 	struct sci_port *s = to_sci_port(port);
2103 
2104 	if (mctrl & TIOCM_LOOP) {
2105 		const struct plat_sci_reg *reg;
2106 
2107 		/*
2108 		 * Standard loopback mode for SCFCR ports.
2109 		 */
2110 		reg = sci_getreg(port, SCFCR);
2111 		if (reg->size)
2112 			serial_port_out(port, SCFCR,
2113 					serial_port_in(port, SCFCR) |
2114 					SCFCR_LOOP);
2115 	}
2116 
2117 	mctrl_gpio_set(s->gpios, mctrl);
2118 
2119 	if (!s->has_rtscts)
2120 		return;
2121 
2122 	if (!(mctrl & TIOCM_RTS)) {
2123 		/* Disable Auto RTS */
2124 		serial_port_out(port, SCFCR,
2125 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2126 
2127 		/* Clear RTS */
2128 		sci_set_rts(port, 0);
2129 	} else if (s->autorts) {
2130 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2131 			/* Enable RTS# pin function */
2132 			serial_port_out(port, SCPCR,
2133 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2134 		}
2135 
2136 		/* Enable Auto RTS */
2137 		serial_port_out(port, SCFCR,
2138 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2139 	} else {
2140 		/* Set RTS */
2141 		sci_set_rts(port, 1);
2142 	}
2143 }
2144 
2145 static unsigned int sci_get_mctrl(struct uart_port *port)
2146 {
2147 	struct sci_port *s = to_sci_port(port);
2148 	struct mctrl_gpios *gpios = s->gpios;
2149 	unsigned int mctrl = 0;
2150 
2151 	mctrl_gpio_get(gpios, &mctrl);
2152 
2153 	/*
2154 	 * CTS/RTS is handled in hardware when supported, while nothing
2155 	 * else is wired up.
2156 	 */
2157 	if (s->autorts) {
2158 		if (sci_get_cts(port))
2159 			mctrl |= TIOCM_CTS;
2160 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2161 		mctrl |= TIOCM_CTS;
2162 	}
2163 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2164 		mctrl |= TIOCM_DSR;
2165 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2166 		mctrl |= TIOCM_CAR;
2167 
2168 	return mctrl;
2169 }
2170 
2171 static void sci_enable_ms(struct uart_port *port)
2172 {
2173 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2174 }
2175 
2176 static void sci_break_ctl(struct uart_port *port, int break_state)
2177 {
2178 	unsigned short scscr, scsptr;
2179 	unsigned long flags;
2180 
2181 	/* check whether the port has SCSPTR */
2182 	if (!sci_getreg(port, SCSPTR)->size) {
2183 		/*
2184 		 * Not supported by hardware. Most parts couple break and rx
2185 		 * interrupts together, with break detection always enabled.
2186 		 */
2187 		return;
2188 	}
2189 
2190 	spin_lock_irqsave(&port->lock, flags);
2191 	scsptr = serial_port_in(port, SCSPTR);
2192 	scscr = serial_port_in(port, SCSCR);
2193 
2194 	if (break_state == -1) {
2195 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2196 		scscr &= ~SCSCR_TE;
2197 	} else {
2198 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2199 		scscr |= SCSCR_TE;
2200 	}
2201 
2202 	serial_port_out(port, SCSPTR, scsptr);
2203 	serial_port_out(port, SCSCR, scscr);
2204 	spin_unlock_irqrestore(&port->lock, flags);
2205 }
2206 
2207 static int sci_startup(struct uart_port *port)
2208 {
2209 	struct sci_port *s = to_sci_port(port);
2210 	int ret;
2211 
2212 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2213 
2214 	sci_request_dma(port);
2215 
2216 	ret = sci_request_irq(s);
2217 	if (unlikely(ret < 0)) {
2218 		sci_free_dma(port);
2219 		return ret;
2220 	}
2221 
2222 	return 0;
2223 }
2224 
2225 static void sci_shutdown(struct uart_port *port)
2226 {
2227 	struct sci_port *s = to_sci_port(port);
2228 	unsigned long flags;
2229 	u16 scr;
2230 
2231 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2232 
2233 	s->autorts = false;
2234 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2235 
2236 	spin_lock_irqsave(&port->lock, flags);
2237 	sci_stop_rx(port);
2238 	sci_stop_tx(port);
2239 	/*
2240 	 * Stop RX and TX, disable related interrupts, keep clock source
2241 	 * and HSCIF TOT bits
2242 	 */
2243 	scr = serial_port_in(port, SCSCR);
2244 	serial_port_out(port, SCSCR, scr &
2245 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2246 	spin_unlock_irqrestore(&port->lock, flags);
2247 
2248 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2249 	if (s->chan_rx_saved) {
2250 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2251 			port->line);
2252 		hrtimer_cancel(&s->rx_timer);
2253 	}
2254 #endif
2255 
2256 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2257 		del_timer_sync(&s->rx_fifo_timer);
2258 	sci_free_irq(s);
2259 	sci_free_dma(port);
2260 }
2261 
2262 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2263 			unsigned int *srr)
2264 {
2265 	unsigned long freq = s->clk_rates[SCI_SCK];
2266 	int err, min_err = INT_MAX;
2267 	unsigned int sr;
2268 
2269 	if (s->port.type != PORT_HSCIF)
2270 		freq *= 2;
2271 
2272 	for_each_sr(sr, s) {
2273 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2274 		if (abs(err) >= abs(min_err))
2275 			continue;
2276 
2277 		min_err = err;
2278 		*srr = sr - 1;
2279 
2280 		if (!err)
2281 			break;
2282 	}
2283 
2284 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2285 		*srr + 1);
2286 	return min_err;
2287 }
2288 
2289 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2290 			unsigned long freq, unsigned int *dlr,
2291 			unsigned int *srr)
2292 {
2293 	int err, min_err = INT_MAX;
2294 	unsigned int sr, dl;
2295 
2296 	if (s->port.type != PORT_HSCIF)
2297 		freq *= 2;
2298 
2299 	for_each_sr(sr, s) {
2300 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2301 		dl = clamp(dl, 1U, 65535U);
2302 
2303 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2304 		if (abs(err) >= abs(min_err))
2305 			continue;
2306 
2307 		min_err = err;
2308 		*dlr = dl;
2309 		*srr = sr - 1;
2310 
2311 		if (!err)
2312 			break;
2313 	}
2314 
2315 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2316 		min_err, *dlr, *srr + 1);
2317 	return min_err;
2318 }
2319 
2320 /* calculate sample rate, BRR, and clock select */
2321 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2322 			  unsigned int *brr, unsigned int *srr,
2323 			  unsigned int *cks)
2324 {
2325 	unsigned long freq = s->clk_rates[SCI_FCK];
2326 	unsigned int sr, br, prediv, scrate, c;
2327 	int err, min_err = INT_MAX;
2328 
2329 	if (s->port.type != PORT_HSCIF)
2330 		freq *= 2;
2331 
2332 	/*
2333 	 * Find the combination of sample rate and clock select with the
2334 	 * smallest deviation from the desired baud rate.
2335 	 * Prefer high sample rates to maximise the receive margin.
2336 	 *
2337 	 * M: Receive margin (%)
2338 	 * N: Ratio of bit rate to clock (N = sampling rate)
2339 	 * D: Clock duty (D = 0 to 1.0)
2340 	 * L: Frame length (L = 9 to 12)
2341 	 * F: Absolute value of clock frequency deviation
2342 	 *
2343 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2344 	 *      (|D - 0.5| / N * (1 + F))|
2345 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2346 	 */
2347 	for_each_sr(sr, s) {
2348 		for (c = 0; c <= 3; c++) {
2349 			/* integerized formulas from HSCIF documentation */
2350 			prediv = sr << (2 * c + 1);
2351 
2352 			/*
2353 			 * We need to calculate:
2354 			 *
2355 			 *     br = freq / (prediv * bps) clamped to [1..256]
2356 			 *     err = freq / (br * prediv) - bps
2357 			 *
2358 			 * Watch out for overflow when calculating the desired
2359 			 * sampling clock rate!
2360 			 */
2361 			if (bps > UINT_MAX / prediv)
2362 				break;
2363 
2364 			scrate = prediv * bps;
2365 			br = DIV_ROUND_CLOSEST(freq, scrate);
2366 			br = clamp(br, 1U, 256U);
2367 
2368 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2369 			if (abs(err) >= abs(min_err))
2370 				continue;
2371 
2372 			min_err = err;
2373 			*brr = br - 1;
2374 			*srr = sr - 1;
2375 			*cks = c;
2376 
2377 			if (!err)
2378 				goto found;
2379 		}
2380 	}
2381 
2382 found:
2383 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2384 		min_err, *brr, *srr + 1, *cks);
2385 	return min_err;
2386 }
2387 
2388 static void sci_reset(struct uart_port *port)
2389 {
2390 	const struct plat_sci_reg *reg;
2391 	unsigned int status;
2392 	struct sci_port *s = to_sci_port(port);
2393 
2394 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2395 
2396 	reg = sci_getreg(port, SCFCR);
2397 	if (reg->size)
2398 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2399 
2400 	sci_clear_SCxSR(port,
2401 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2402 			SCxSR_BREAK_CLEAR(port));
2403 	if (sci_getreg(port, SCLSR)->size) {
2404 		status = serial_port_in(port, SCLSR);
2405 		status &= ~(SCLSR_TO | SCLSR_ORER);
2406 		serial_port_out(port, SCLSR, status);
2407 	}
2408 
2409 	if (s->rx_trigger > 1) {
2410 		if (s->rx_fifo_timeout) {
2411 			scif_set_rtrg(port, 1);
2412 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2413 		} else {
2414 			if (port->type == PORT_SCIFA ||
2415 			    port->type == PORT_SCIFB)
2416 				scif_set_rtrg(port, 1);
2417 			else
2418 				scif_set_rtrg(port, s->rx_trigger);
2419 		}
2420 	}
2421 }
2422 
2423 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2424 		            const struct ktermios *old)
2425 {
2426 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2427 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2428 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2429 	struct sci_port *s = to_sci_port(port);
2430 	const struct plat_sci_reg *reg;
2431 	int min_err = INT_MAX, err;
2432 	unsigned long max_freq = 0;
2433 	int best_clk = -1;
2434 	unsigned long flags;
2435 
2436 	if ((termios->c_cflag & CSIZE) == CS7) {
2437 		smr_val |= SCSMR_CHR;
2438 	} else {
2439 		termios->c_cflag &= ~CSIZE;
2440 		termios->c_cflag |= CS8;
2441 	}
2442 	if (termios->c_cflag & PARENB)
2443 		smr_val |= SCSMR_PE;
2444 	if (termios->c_cflag & PARODD)
2445 		smr_val |= SCSMR_PE | SCSMR_ODD;
2446 	if (termios->c_cflag & CSTOPB)
2447 		smr_val |= SCSMR_STOP;
2448 
2449 	/*
2450 	 * earlyprintk comes here early on with port->uartclk set to zero.
2451 	 * the clock framework is not up and running at this point so here
2452 	 * we assume that 115200 is the maximum baud rate. please note that
2453 	 * the baud rate is not programmed during earlyprintk - it is assumed
2454 	 * that the previous boot loader has enabled required clocks and
2455 	 * setup the baud rate generator hardware for us already.
2456 	 */
2457 	if (!port->uartclk) {
2458 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2459 		goto done;
2460 	}
2461 
2462 	for (i = 0; i < SCI_NUM_CLKS; i++)
2463 		max_freq = max(max_freq, s->clk_rates[i]);
2464 
2465 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2466 	if (!baud)
2467 		goto done;
2468 
2469 	/*
2470 	 * There can be multiple sources for the sampling clock.  Find the one
2471 	 * that gives us the smallest deviation from the desired baud rate.
2472 	 */
2473 
2474 	/* Optional Undivided External Clock */
2475 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2476 	    port->type != PORT_SCIFB) {
2477 		err = sci_sck_calc(s, baud, &srr1);
2478 		if (abs(err) < abs(min_err)) {
2479 			best_clk = SCI_SCK;
2480 			scr_val = SCSCR_CKE1;
2481 			sccks = SCCKS_CKS;
2482 			min_err = err;
2483 			srr = srr1;
2484 			if (!err)
2485 				goto done;
2486 		}
2487 	}
2488 
2489 	/* Optional BRG Frequency Divided External Clock */
2490 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2491 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2492 				   &srr1);
2493 		if (abs(err) < abs(min_err)) {
2494 			best_clk = SCI_SCIF_CLK;
2495 			scr_val = SCSCR_CKE1;
2496 			sccks = 0;
2497 			min_err = err;
2498 			dl = dl1;
2499 			srr = srr1;
2500 			if (!err)
2501 				goto done;
2502 		}
2503 	}
2504 
2505 	/* Optional BRG Frequency Divided Internal Clock */
2506 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2507 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2508 				   &srr1);
2509 		if (abs(err) < abs(min_err)) {
2510 			best_clk = SCI_BRG_INT;
2511 			scr_val = SCSCR_CKE1;
2512 			sccks = SCCKS_XIN;
2513 			min_err = err;
2514 			dl = dl1;
2515 			srr = srr1;
2516 			if (!min_err)
2517 				goto done;
2518 		}
2519 	}
2520 
2521 	/* Divided Functional Clock using standard Bit Rate Register */
2522 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2523 	if (abs(err) < abs(min_err)) {
2524 		best_clk = SCI_FCK;
2525 		scr_val = 0;
2526 		min_err = err;
2527 		brr = brr1;
2528 		srr = srr1;
2529 		cks = cks1;
2530 	}
2531 
2532 done:
2533 	if (best_clk >= 0)
2534 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2535 			s->clks[best_clk], baud, min_err);
2536 
2537 	sci_port_enable(s);
2538 
2539 	/*
2540 	 * Program the optional External Baud Rate Generator (BRG) first.
2541 	 * It controls the mux to select (H)SCK or frequency divided clock.
2542 	 */
2543 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2544 		serial_port_out(port, SCDL, dl);
2545 		serial_port_out(port, SCCKS, sccks);
2546 	}
2547 
2548 	spin_lock_irqsave(&port->lock, flags);
2549 
2550 	sci_reset(port);
2551 
2552 	uart_update_timeout(port, termios->c_cflag, baud);
2553 
2554 	/* byte size and parity */
2555 	bits = tty_get_frame_size(termios->c_cflag);
2556 
2557 	if (sci_getreg(port, SEMR)->size)
2558 		serial_port_out(port, SEMR, 0);
2559 
2560 	if (best_clk >= 0) {
2561 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2562 			switch (srr + 1) {
2563 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2564 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2565 			case 11: smr_val |= SCSMR_SRC_11; break;
2566 			case 13: smr_val |= SCSMR_SRC_13; break;
2567 			case 16: smr_val |= SCSMR_SRC_16; break;
2568 			case 17: smr_val |= SCSMR_SRC_17; break;
2569 			case 19: smr_val |= SCSMR_SRC_19; break;
2570 			case 27: smr_val |= SCSMR_SRC_27; break;
2571 			}
2572 		smr_val |= cks;
2573 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2574 		serial_port_out(port, SCSMR, smr_val);
2575 		serial_port_out(port, SCBRR, brr);
2576 		if (sci_getreg(port, HSSRR)->size) {
2577 			unsigned int hssrr = srr | HSCIF_SRE;
2578 			/* Calculate deviation from intended rate at the
2579 			 * center of the last stop bit in sampling clocks.
2580 			 */
2581 			int last_stop = bits * 2 - 1;
2582 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2583 							  (int)(srr + 1),
2584 							  2 * (int)baud);
2585 
2586 			if (abs(deviation) >= 2) {
2587 				/* At least two sampling clocks off at the
2588 				 * last stop bit; we can increase the error
2589 				 * margin by shifting the sampling point.
2590 				 */
2591 				int shift = clamp(deviation / 2, -8, 7);
2592 
2593 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2594 					 HSCIF_SRHP_MASK;
2595 				hssrr |= HSCIF_SRDE;
2596 			}
2597 			serial_port_out(port, HSSRR, hssrr);
2598 		}
2599 
2600 		/* Wait one bit interval */
2601 		udelay((1000000 + (baud - 1)) / baud);
2602 	} else {
2603 		/* Don't touch the bit rate configuration */
2604 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2605 		smr_val |= serial_port_in(port, SCSMR) &
2606 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2607 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2608 		serial_port_out(port, SCSMR, smr_val);
2609 	}
2610 
2611 	sci_init_pins(port, termios->c_cflag);
2612 
2613 	port->status &= ~UPSTAT_AUTOCTS;
2614 	s->autorts = false;
2615 	reg = sci_getreg(port, SCFCR);
2616 	if (reg->size) {
2617 		unsigned short ctrl = serial_port_in(port, SCFCR);
2618 
2619 		if ((port->flags & UPF_HARD_FLOW) &&
2620 		    (termios->c_cflag & CRTSCTS)) {
2621 			/* There is no CTS interrupt to restart the hardware */
2622 			port->status |= UPSTAT_AUTOCTS;
2623 			/* MCE is enabled when RTS is raised */
2624 			s->autorts = true;
2625 		}
2626 
2627 		/*
2628 		 * As we've done a sci_reset() above, ensure we don't
2629 		 * interfere with the FIFOs while toggling MCE. As the
2630 		 * reset values could still be set, simply mask them out.
2631 		 */
2632 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2633 
2634 		serial_port_out(port, SCFCR, ctrl);
2635 	}
2636 	if (port->flags & UPF_HARD_FLOW) {
2637 		/* Refresh (Auto) RTS */
2638 		sci_set_mctrl(port, port->mctrl);
2639 	}
2640 
2641 	/*
2642 	 * For SCI, TE (transmit enable) must be set after setting TIE
2643 	 * (transmit interrupt enable) or in the same instruction to
2644 	 * start the transmitting process. So skip setting TE here for SCI.
2645 	 */
2646 	if (port->type != PORT_SCI)
2647 		scr_val |= SCSCR_TE;
2648 	scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2649 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2650 	if ((srr + 1 == 5) &&
2651 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2652 		/*
2653 		 * In asynchronous mode, when the sampling rate is 1/5, first
2654 		 * received data may become invalid on some SCIFA and SCIFB.
2655 		 * To avoid this problem wait more than 1 serial data time (1
2656 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2657 		 */
2658 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2659 	}
2660 
2661 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2662 	s->rx_frame = (10000 * bits) / (baud / 100);
2663 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2664 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2665 #endif
2666 
2667 	if ((termios->c_cflag & CREAD) != 0)
2668 		sci_start_rx(port);
2669 
2670 	spin_unlock_irqrestore(&port->lock, flags);
2671 
2672 	sci_port_disable(s);
2673 
2674 	if (UART_ENABLE_MS(port, termios->c_cflag))
2675 		sci_enable_ms(port);
2676 }
2677 
2678 static void sci_pm(struct uart_port *port, unsigned int state,
2679 		   unsigned int oldstate)
2680 {
2681 	struct sci_port *sci_port = to_sci_port(port);
2682 
2683 	switch (state) {
2684 	case UART_PM_STATE_OFF:
2685 		sci_port_disable(sci_port);
2686 		break;
2687 	default:
2688 		sci_port_enable(sci_port);
2689 		break;
2690 	}
2691 }
2692 
2693 static const char *sci_type(struct uart_port *port)
2694 {
2695 	switch (port->type) {
2696 	case PORT_IRDA:
2697 		return "irda";
2698 	case PORT_SCI:
2699 		return "sci";
2700 	case PORT_SCIF:
2701 		return "scif";
2702 	case PORT_SCIFA:
2703 		return "scifa";
2704 	case PORT_SCIFB:
2705 		return "scifb";
2706 	case PORT_HSCIF:
2707 		return "hscif";
2708 	}
2709 
2710 	return NULL;
2711 }
2712 
2713 static int sci_remap_port(struct uart_port *port)
2714 {
2715 	struct sci_port *sport = to_sci_port(port);
2716 
2717 	/*
2718 	 * Nothing to do if there's already an established membase.
2719 	 */
2720 	if (port->membase)
2721 		return 0;
2722 
2723 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2724 		port->membase = ioremap(port->mapbase, sport->reg_size);
2725 		if (unlikely(!port->membase)) {
2726 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2727 			return -ENXIO;
2728 		}
2729 	} else {
2730 		/*
2731 		 * For the simple (and majority of) cases where we don't
2732 		 * need to do any remapping, just cast the cookie
2733 		 * directly.
2734 		 */
2735 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2736 	}
2737 
2738 	return 0;
2739 }
2740 
2741 static void sci_release_port(struct uart_port *port)
2742 {
2743 	struct sci_port *sport = to_sci_port(port);
2744 
2745 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2746 		iounmap(port->membase);
2747 		port->membase = NULL;
2748 	}
2749 
2750 	release_mem_region(port->mapbase, sport->reg_size);
2751 }
2752 
2753 static int sci_request_port(struct uart_port *port)
2754 {
2755 	struct resource *res;
2756 	struct sci_port *sport = to_sci_port(port);
2757 	int ret;
2758 
2759 	res = request_mem_region(port->mapbase, sport->reg_size,
2760 				 dev_name(port->dev));
2761 	if (unlikely(res == NULL)) {
2762 		dev_err(port->dev, "request_mem_region failed.");
2763 		return -EBUSY;
2764 	}
2765 
2766 	ret = sci_remap_port(port);
2767 	if (unlikely(ret != 0)) {
2768 		release_resource(res);
2769 		return ret;
2770 	}
2771 
2772 	return 0;
2773 }
2774 
2775 static void sci_config_port(struct uart_port *port, int flags)
2776 {
2777 	if (flags & UART_CONFIG_TYPE) {
2778 		struct sci_port *sport = to_sci_port(port);
2779 
2780 		port->type = sport->cfg->type;
2781 		sci_request_port(port);
2782 	}
2783 }
2784 
2785 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2786 {
2787 	if (ser->baud_base < 2400)
2788 		/* No paper tape reader for Mitch.. */
2789 		return -EINVAL;
2790 
2791 	return 0;
2792 }
2793 
2794 static const struct uart_ops sci_uart_ops = {
2795 	.tx_empty	= sci_tx_empty,
2796 	.set_mctrl	= sci_set_mctrl,
2797 	.get_mctrl	= sci_get_mctrl,
2798 	.start_tx	= sci_start_tx,
2799 	.stop_tx	= sci_stop_tx,
2800 	.stop_rx	= sci_stop_rx,
2801 	.enable_ms	= sci_enable_ms,
2802 	.break_ctl	= sci_break_ctl,
2803 	.startup	= sci_startup,
2804 	.shutdown	= sci_shutdown,
2805 	.flush_buffer	= sci_flush_buffer,
2806 	.set_termios	= sci_set_termios,
2807 	.pm		= sci_pm,
2808 	.type		= sci_type,
2809 	.release_port	= sci_release_port,
2810 	.request_port	= sci_request_port,
2811 	.config_port	= sci_config_port,
2812 	.verify_port	= sci_verify_port,
2813 #ifdef CONFIG_CONSOLE_POLL
2814 	.poll_get_char	= sci_poll_get_char,
2815 	.poll_put_char	= sci_poll_put_char,
2816 #endif
2817 };
2818 
2819 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2820 {
2821 	const char *clk_names[] = {
2822 		[SCI_FCK] = "fck",
2823 		[SCI_SCK] = "sck",
2824 		[SCI_BRG_INT] = "brg_int",
2825 		[SCI_SCIF_CLK] = "scif_clk",
2826 	};
2827 	struct clk *clk;
2828 	unsigned int i;
2829 
2830 	if (sci_port->cfg->type == PORT_HSCIF)
2831 		clk_names[SCI_SCK] = "hsck";
2832 
2833 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2834 		clk = devm_clk_get_optional(dev, clk_names[i]);
2835 		if (IS_ERR(clk))
2836 			return PTR_ERR(clk);
2837 
2838 		if (!clk && i == SCI_FCK) {
2839 			/*
2840 			 * Not all SH platforms declare a clock lookup entry
2841 			 * for SCI devices, in which case we need to get the
2842 			 * global "peripheral_clk" clock.
2843 			 */
2844 			clk = devm_clk_get(dev, "peripheral_clk");
2845 			if (IS_ERR(clk))
2846 				return dev_err_probe(dev, PTR_ERR(clk),
2847 						     "failed to get %s\n",
2848 						     clk_names[i]);
2849 		}
2850 
2851 		if (!clk)
2852 			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2853 		else
2854 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2855 				clk, clk_get_rate(clk));
2856 		sci_port->clks[i] = clk;
2857 	}
2858 	return 0;
2859 }
2860 
2861 static const struct sci_port_params *
2862 sci_probe_regmap(const struct plat_sci_port *cfg)
2863 {
2864 	unsigned int regtype;
2865 
2866 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2867 		return &sci_port_params[cfg->regtype];
2868 
2869 	switch (cfg->type) {
2870 	case PORT_SCI:
2871 		regtype = SCIx_SCI_REGTYPE;
2872 		break;
2873 	case PORT_IRDA:
2874 		regtype = SCIx_IRDA_REGTYPE;
2875 		break;
2876 	case PORT_SCIFA:
2877 		regtype = SCIx_SCIFA_REGTYPE;
2878 		break;
2879 	case PORT_SCIFB:
2880 		regtype = SCIx_SCIFB_REGTYPE;
2881 		break;
2882 	case PORT_SCIF:
2883 		/*
2884 		 * The SH-4 is a bit of a misnomer here, although that's
2885 		 * where this particular port layout originated. This
2886 		 * configuration (or some slight variation thereof)
2887 		 * remains the dominant model for all SCIFs.
2888 		 */
2889 		regtype = SCIx_SH4_SCIF_REGTYPE;
2890 		break;
2891 	case PORT_HSCIF:
2892 		regtype = SCIx_HSCIF_REGTYPE;
2893 		break;
2894 	default:
2895 		pr_err("Can't probe register map for given port\n");
2896 		return NULL;
2897 	}
2898 
2899 	return &sci_port_params[regtype];
2900 }
2901 
2902 static int sci_init_single(struct platform_device *dev,
2903 			   struct sci_port *sci_port, unsigned int index,
2904 			   const struct plat_sci_port *p, bool early)
2905 {
2906 	struct uart_port *port = &sci_port->port;
2907 	const struct resource *res;
2908 	unsigned int i;
2909 	int ret;
2910 
2911 	sci_port->cfg	= p;
2912 
2913 	port->ops	= &sci_uart_ops;
2914 	port->iotype	= UPIO_MEM;
2915 	port->line	= index;
2916 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2917 
2918 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2919 	if (res == NULL)
2920 		return -ENOMEM;
2921 
2922 	port->mapbase = res->start;
2923 	sci_port->reg_size = resource_size(res);
2924 
2925 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2926 		if (i)
2927 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2928 		else
2929 			sci_port->irqs[i] = platform_get_irq(dev, i);
2930 	}
2931 
2932 	/*
2933 	 * The fourth interrupt on SCI port is transmit end interrupt, so
2934 	 * shuffle the interrupts.
2935 	 */
2936 	if (p->type == PORT_SCI)
2937 		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
2938 
2939 	/* The SCI generates several interrupts. They can be muxed together or
2940 	 * connected to different interrupt lines. In the muxed case only one
2941 	 * interrupt resource is specified as there is only one interrupt ID.
2942 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2943 	 * from the SCI, however those signals might have their own individual
2944 	 * interrupt ID numbers, or muxed together with another interrupt.
2945 	 */
2946 	if (sci_port->irqs[0] < 0)
2947 		return -ENXIO;
2948 
2949 	if (sci_port->irqs[1] < 0)
2950 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2951 			sci_port->irqs[i] = sci_port->irqs[0];
2952 
2953 	sci_port->params = sci_probe_regmap(p);
2954 	if (unlikely(sci_port->params == NULL))
2955 		return -EINVAL;
2956 
2957 	switch (p->type) {
2958 	case PORT_SCIFB:
2959 		sci_port->rx_trigger = 48;
2960 		break;
2961 	case PORT_HSCIF:
2962 		sci_port->rx_trigger = 64;
2963 		break;
2964 	case PORT_SCIFA:
2965 		sci_port->rx_trigger = 32;
2966 		break;
2967 	case PORT_SCIF:
2968 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2969 			/* RX triggering not implemented for this IP */
2970 			sci_port->rx_trigger = 1;
2971 		else
2972 			sci_port->rx_trigger = 8;
2973 		break;
2974 	default:
2975 		sci_port->rx_trigger = 1;
2976 		break;
2977 	}
2978 
2979 	sci_port->rx_fifo_timeout = 0;
2980 	sci_port->hscif_tot = 0;
2981 
2982 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2983 	 * match the SoC datasheet, this should be investigated. Let platform
2984 	 * data override the sampling rate for now.
2985 	 */
2986 	sci_port->sampling_rate_mask = p->sampling_rate
2987 				     ? SCI_SR(p->sampling_rate)
2988 				     : sci_port->params->sampling_rate_mask;
2989 
2990 	if (!early) {
2991 		ret = sci_init_clocks(sci_port, &dev->dev);
2992 		if (ret < 0)
2993 			return ret;
2994 
2995 		port->dev = &dev->dev;
2996 
2997 		pm_runtime_enable(&dev->dev);
2998 	}
2999 
3000 	port->type		= p->type;
3001 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
3002 	port->fifosize		= sci_port->params->fifosize;
3003 
3004 	if (port->type == PORT_SCI && !dev->dev.of_node) {
3005 		if (sci_port->reg_size >= 0x20)
3006 			port->regshift = 2;
3007 		else
3008 			port->regshift = 1;
3009 	}
3010 
3011 	/*
3012 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
3013 	 * for the multi-IRQ ports, which is where we are primarily
3014 	 * concerned with the shutdown path synchronization.
3015 	 *
3016 	 * For the muxed case there's nothing more to do.
3017 	 */
3018 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
3019 	port->irqflags		= 0;
3020 
3021 	port->serial_in		= sci_serial_in;
3022 	port->serial_out	= sci_serial_out;
3023 
3024 	return 0;
3025 }
3026 
3027 static void sci_cleanup_single(struct sci_port *port)
3028 {
3029 	pm_runtime_disable(port->port.dev);
3030 }
3031 
3032 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3033     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3034 static void serial_console_putchar(struct uart_port *port, unsigned char ch)
3035 {
3036 	sci_poll_put_char(port, ch);
3037 }
3038 
3039 /*
3040  *	Print a string to the serial port trying not to disturb
3041  *	any possible real use of the port...
3042  */
3043 static void serial_console_write(struct console *co, const char *s,
3044 				 unsigned count)
3045 {
3046 	struct sci_port *sci_port = &sci_ports[co->index];
3047 	struct uart_port *port = &sci_port->port;
3048 	unsigned short bits, ctrl, ctrl_temp;
3049 	unsigned long flags;
3050 	int locked = 1;
3051 
3052 	if (port->sysrq)
3053 		locked = 0;
3054 	else if (oops_in_progress)
3055 		locked = spin_trylock_irqsave(&port->lock, flags);
3056 	else
3057 		spin_lock_irqsave(&port->lock, flags);
3058 
3059 	/* first save SCSCR then disable interrupts, keep clock source */
3060 	ctrl = serial_port_in(port, SCSCR);
3061 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3062 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3063 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3064 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3065 
3066 	uart_console_write(port, s, count, serial_console_putchar);
3067 
3068 	/* wait until fifo is empty and last bit has been transmitted */
3069 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3070 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3071 		cpu_relax();
3072 
3073 	/* restore the SCSCR */
3074 	serial_port_out(port, SCSCR, ctrl);
3075 
3076 	if (locked)
3077 		spin_unlock_irqrestore(&port->lock, flags);
3078 }
3079 
3080 static int serial_console_setup(struct console *co, char *options)
3081 {
3082 	struct sci_port *sci_port;
3083 	struct uart_port *port;
3084 	int baud = 115200;
3085 	int bits = 8;
3086 	int parity = 'n';
3087 	int flow = 'n';
3088 	int ret;
3089 
3090 	/*
3091 	 * Refuse to handle any bogus ports.
3092 	 */
3093 	if (co->index < 0 || co->index >= SCI_NPORTS)
3094 		return -ENODEV;
3095 
3096 	sci_port = &sci_ports[co->index];
3097 	port = &sci_port->port;
3098 
3099 	/*
3100 	 * Refuse to handle uninitialized ports.
3101 	 */
3102 	if (!port->ops)
3103 		return -ENODEV;
3104 
3105 	ret = sci_remap_port(port);
3106 	if (unlikely(ret != 0))
3107 		return ret;
3108 
3109 	if (options)
3110 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3111 
3112 	return uart_set_options(port, co, baud, parity, bits, flow);
3113 }
3114 
3115 static struct console serial_console = {
3116 	.name		= "ttySC",
3117 	.device		= uart_console_device,
3118 	.write		= serial_console_write,
3119 	.setup		= serial_console_setup,
3120 	.flags		= CON_PRINTBUFFER,
3121 	.index		= -1,
3122 	.data		= &sci_uart_driver,
3123 };
3124 
3125 #ifdef CONFIG_SUPERH
3126 static char early_serial_buf[32];
3127 
3128 static int early_serial_console_setup(struct console *co, char *options)
3129 {
3130 	/*
3131 	 * This early console is always registered using the earlyprintk=
3132 	 * parameter, which does not call add_preferred_console(). Thus
3133 	 * @options is always NULL and the options for this early console
3134 	 * are passed using a custom buffer.
3135 	 */
3136 	WARN_ON(options);
3137 
3138 	return serial_console_setup(co, early_serial_buf);
3139 }
3140 
3141 static struct console early_serial_console = {
3142 	.name           = "early_ttySC",
3143 	.write          = serial_console_write,
3144 	.setup		= early_serial_console_setup,
3145 	.flags          = CON_PRINTBUFFER,
3146 	.index		= -1,
3147 };
3148 
3149 static int sci_probe_earlyprintk(struct platform_device *pdev)
3150 {
3151 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3152 
3153 	if (early_serial_console.data)
3154 		return -EEXIST;
3155 
3156 	early_serial_console.index = pdev->id;
3157 
3158 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3159 
3160 	if (!strstr(early_serial_buf, "keep"))
3161 		early_serial_console.flags |= CON_BOOT;
3162 
3163 	register_console(&early_serial_console);
3164 	return 0;
3165 }
3166 #endif
3167 
3168 #define SCI_CONSOLE	(&serial_console)
3169 
3170 #else
3171 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3172 {
3173 	return -EINVAL;
3174 }
3175 
3176 #define SCI_CONSOLE	NULL
3177 
3178 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3179 
3180 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3181 
3182 static DEFINE_MUTEX(sci_uart_registration_lock);
3183 static struct uart_driver sci_uart_driver = {
3184 	.owner		= THIS_MODULE,
3185 	.driver_name	= "sci",
3186 	.dev_name	= "ttySC",
3187 	.major		= SCI_MAJOR,
3188 	.minor		= SCI_MINOR_START,
3189 	.nr		= SCI_NPORTS,
3190 	.cons		= SCI_CONSOLE,
3191 };
3192 
3193 static int sci_remove(struct platform_device *dev)
3194 {
3195 	struct sci_port *port = platform_get_drvdata(dev);
3196 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3197 
3198 	sci_ports_in_use &= ~BIT(port->port.line);
3199 	uart_remove_one_port(&sci_uart_driver, &port->port);
3200 
3201 	sci_cleanup_single(port);
3202 
3203 	if (port->port.fifosize > 1)
3204 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3205 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3206 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3207 
3208 	return 0;
3209 }
3210 
3211 
3212 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3213 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3214 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3215 
3216 static const struct of_device_id of_sci_match[] __maybe_unused = {
3217 	/* SoC-specific types */
3218 	{
3219 		.compatible = "renesas,scif-r7s72100",
3220 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3221 	},
3222 	{
3223 		.compatible = "renesas,scif-r7s9210",
3224 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3225 	},
3226 	{
3227 		.compatible = "renesas,scif-r9a07g044",
3228 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3229 	},
3230 	/* Family-specific types */
3231 	{
3232 		.compatible = "renesas,rcar-gen1-scif",
3233 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3234 	}, {
3235 		.compatible = "renesas,rcar-gen2-scif",
3236 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3237 	}, {
3238 		.compatible = "renesas,rcar-gen3-scif",
3239 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3240 	}, {
3241 		.compatible = "renesas,rcar-gen4-scif",
3242 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3243 	},
3244 	/* Generic types */
3245 	{
3246 		.compatible = "renesas,scif",
3247 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3248 	}, {
3249 		.compatible = "renesas,scifa",
3250 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3251 	}, {
3252 		.compatible = "renesas,scifb",
3253 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3254 	}, {
3255 		.compatible = "renesas,hscif",
3256 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3257 	}, {
3258 		.compatible = "renesas,sci",
3259 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3260 	}, {
3261 		/* Terminator */
3262 	},
3263 };
3264 MODULE_DEVICE_TABLE(of, of_sci_match);
3265 
3266 static void sci_reset_control_assert(void *data)
3267 {
3268 	reset_control_assert(data);
3269 }
3270 
3271 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3272 					  unsigned int *dev_id)
3273 {
3274 	struct device_node *np = pdev->dev.of_node;
3275 	struct reset_control *rstc;
3276 	struct plat_sci_port *p;
3277 	struct sci_port *sp;
3278 	const void *data;
3279 	int id, ret;
3280 
3281 	if (!IS_ENABLED(CONFIG_OF) || !np)
3282 		return ERR_PTR(-EINVAL);
3283 
3284 	data = of_device_get_match_data(&pdev->dev);
3285 
3286 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3287 	if (IS_ERR(rstc))
3288 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3289 					     "failed to get reset ctrl\n"));
3290 
3291 	ret = reset_control_deassert(rstc);
3292 	if (ret) {
3293 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3294 		return ERR_PTR(ret);
3295 	}
3296 
3297 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3298 	if (ret) {
3299 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3300 			ret);
3301 		return ERR_PTR(ret);
3302 	}
3303 
3304 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3305 	if (!p)
3306 		return ERR_PTR(-ENOMEM);
3307 
3308 	/* Get the line number from the aliases node. */
3309 	id = of_alias_get_id(np, "serial");
3310 	if (id < 0 && ~sci_ports_in_use)
3311 		id = ffz(sci_ports_in_use);
3312 	if (id < 0) {
3313 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3314 		return ERR_PTR(-EINVAL);
3315 	}
3316 	if (id >= ARRAY_SIZE(sci_ports)) {
3317 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3318 		return ERR_PTR(-EINVAL);
3319 	}
3320 
3321 	sp = &sci_ports[id];
3322 	*dev_id = id;
3323 
3324 	p->type = SCI_OF_TYPE(data);
3325 	p->regtype = SCI_OF_REGTYPE(data);
3326 
3327 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3328 
3329 	return p;
3330 }
3331 
3332 static int sci_probe_single(struct platform_device *dev,
3333 				      unsigned int index,
3334 				      struct plat_sci_port *p,
3335 				      struct sci_port *sciport)
3336 {
3337 	int ret;
3338 
3339 	/* Sanity check */
3340 	if (unlikely(index >= SCI_NPORTS)) {
3341 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3342 			   index+1, SCI_NPORTS);
3343 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3344 		return -EINVAL;
3345 	}
3346 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3347 	if (sci_ports_in_use & BIT(index))
3348 		return -EBUSY;
3349 
3350 	mutex_lock(&sci_uart_registration_lock);
3351 	if (!sci_uart_driver.state) {
3352 		ret = uart_register_driver(&sci_uart_driver);
3353 		if (ret) {
3354 			mutex_unlock(&sci_uart_registration_lock);
3355 			return ret;
3356 		}
3357 	}
3358 	mutex_unlock(&sci_uart_registration_lock);
3359 
3360 	ret = sci_init_single(dev, sciport, index, p, false);
3361 	if (ret)
3362 		return ret;
3363 
3364 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3365 	if (IS_ERR(sciport->gpios))
3366 		return PTR_ERR(sciport->gpios);
3367 
3368 	if (sciport->has_rtscts) {
3369 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3370 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3371 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3372 			return -EINVAL;
3373 		}
3374 		sciport->port.flags |= UPF_HARD_FLOW;
3375 	}
3376 
3377 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3378 	if (ret) {
3379 		sci_cleanup_single(sciport);
3380 		return ret;
3381 	}
3382 
3383 	return 0;
3384 }
3385 
3386 static int sci_probe(struct platform_device *dev)
3387 {
3388 	struct plat_sci_port *p;
3389 	struct sci_port *sp;
3390 	unsigned int dev_id;
3391 	int ret;
3392 
3393 	/*
3394 	 * If we've come here via earlyprintk initialization, head off to
3395 	 * the special early probe. We don't have sufficient device state
3396 	 * to make it beyond this yet.
3397 	 */
3398 #ifdef CONFIG_SUPERH
3399 	if (is_sh_early_platform_device(dev))
3400 		return sci_probe_earlyprintk(dev);
3401 #endif
3402 
3403 	if (dev->dev.of_node) {
3404 		p = sci_parse_dt(dev, &dev_id);
3405 		if (IS_ERR(p))
3406 			return PTR_ERR(p);
3407 	} else {
3408 		p = dev->dev.platform_data;
3409 		if (p == NULL) {
3410 			dev_err(&dev->dev, "no platform data supplied\n");
3411 			return -EINVAL;
3412 		}
3413 
3414 		dev_id = dev->id;
3415 	}
3416 
3417 	sp = &sci_ports[dev_id];
3418 	platform_set_drvdata(dev, sp);
3419 
3420 	ret = sci_probe_single(dev, dev_id, p, sp);
3421 	if (ret)
3422 		return ret;
3423 
3424 	if (sp->port.fifosize > 1) {
3425 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3426 		if (ret)
3427 			return ret;
3428 	}
3429 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3430 	    sp->port.type == PORT_HSCIF) {
3431 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3432 		if (ret) {
3433 			if (sp->port.fifosize > 1) {
3434 				device_remove_file(&dev->dev,
3435 						   &dev_attr_rx_fifo_trigger);
3436 			}
3437 			return ret;
3438 		}
3439 	}
3440 
3441 #ifdef CONFIG_SH_STANDARD_BIOS
3442 	sh_bios_gdb_detach();
3443 #endif
3444 
3445 	sci_ports_in_use |= BIT(dev_id);
3446 	return 0;
3447 }
3448 
3449 static __maybe_unused int sci_suspend(struct device *dev)
3450 {
3451 	struct sci_port *sport = dev_get_drvdata(dev);
3452 
3453 	if (sport)
3454 		uart_suspend_port(&sci_uart_driver, &sport->port);
3455 
3456 	return 0;
3457 }
3458 
3459 static __maybe_unused int sci_resume(struct device *dev)
3460 {
3461 	struct sci_port *sport = dev_get_drvdata(dev);
3462 
3463 	if (sport)
3464 		uart_resume_port(&sci_uart_driver, &sport->port);
3465 
3466 	return 0;
3467 }
3468 
3469 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3470 
3471 static struct platform_driver sci_driver = {
3472 	.probe		= sci_probe,
3473 	.remove		= sci_remove,
3474 	.driver		= {
3475 		.name	= "sh-sci",
3476 		.pm	= &sci_dev_pm_ops,
3477 		.of_match_table = of_match_ptr(of_sci_match),
3478 	},
3479 };
3480 
3481 static int __init sci_init(void)
3482 {
3483 	pr_info("%s\n", banner);
3484 
3485 	return platform_driver_register(&sci_driver);
3486 }
3487 
3488 static void __exit sci_exit(void)
3489 {
3490 	platform_driver_unregister(&sci_driver);
3491 
3492 	if (sci_uart_driver.state)
3493 		uart_unregister_driver(&sci_uart_driver);
3494 }
3495 
3496 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3497 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3498 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3499 #endif
3500 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3501 static struct plat_sci_port port_cfg __initdata;
3502 
3503 static int __init early_console_setup(struct earlycon_device *device,
3504 				      int type)
3505 {
3506 	if (!device->port.membase)
3507 		return -ENODEV;
3508 
3509 	device->port.serial_in = sci_serial_in;
3510 	device->port.serial_out	= sci_serial_out;
3511 	device->port.type = type;
3512 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3513 	port_cfg.type = type;
3514 	sci_ports[0].cfg = &port_cfg;
3515 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3516 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3517 	sci_serial_out(&sci_ports[0].port, SCSCR,
3518 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3519 
3520 	device->con->write = serial_console_write;
3521 	return 0;
3522 }
3523 static int __init sci_early_console_setup(struct earlycon_device *device,
3524 					  const char *opt)
3525 {
3526 	return early_console_setup(device, PORT_SCI);
3527 }
3528 static int __init scif_early_console_setup(struct earlycon_device *device,
3529 					  const char *opt)
3530 {
3531 	return early_console_setup(device, PORT_SCIF);
3532 }
3533 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3534 					  const char *opt)
3535 {
3536 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3537 	return early_console_setup(device, PORT_SCIF);
3538 }
3539 
3540 static int __init scifa_early_console_setup(struct earlycon_device *device,
3541 					  const char *opt)
3542 {
3543 	return early_console_setup(device, PORT_SCIFA);
3544 }
3545 static int __init scifb_early_console_setup(struct earlycon_device *device,
3546 					  const char *opt)
3547 {
3548 	return early_console_setup(device, PORT_SCIFB);
3549 }
3550 static int __init hscif_early_console_setup(struct earlycon_device *device,
3551 					  const char *opt)
3552 {
3553 	return early_console_setup(device, PORT_HSCIF);
3554 }
3555 
3556 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3557 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3558 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3559 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3560 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3561 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3562 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3563 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3564 
3565 module_init(sci_init);
3566 module_exit(sci_exit);
3567 
3568 MODULE_LICENSE("GPL");
3569 MODULE_ALIAS("platform:sh-sci");
3570 MODULE_AUTHOR("Paul Mundt");
3571 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3572