xref: /linux/drivers/tty/serial/sh-sci.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #undef DEBUG
19 
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/module.h>
35 #include <linux/mm.h>
36 #include <linux/of.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm_runtime.h>
40 #include <linux/scatterlist.h>
41 #include <linux/serial.h>
42 #include <linux/serial_sci.h>
43 #include <linux/sh_dma.h>
44 #include <linux/slab.h>
45 #include <linux/string.h>
46 #include <linux/sysrq.h>
47 #include <linux/timer.h>
48 #include <linux/tty.h>
49 #include <linux/tty_flip.h>
50 
51 #ifdef CONFIG_SUPERH
52 #include <asm/sh_bios.h>
53 #include <asm/platform_early.h>
54 #endif
55 
56 #include "serial_mctrl_gpio.h"
57 #include "sh-sci.h"
58 
59 /* Offsets into the sci_port->irqs array */
60 enum {
61 	SCIx_ERI_IRQ,
62 	SCIx_RXI_IRQ,
63 	SCIx_TXI_IRQ,
64 	SCIx_BRI_IRQ,
65 	SCIx_DRI_IRQ,
66 	SCIx_TEI_IRQ,
67 	SCIx_NR_IRQS,
68 
69 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
70 };
71 
72 #define SCIx_IRQ_IS_MUXED(port)			\
73 	((port)->irqs[SCIx_ERI_IRQ] ==	\
74 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
75 	((port)->irqs[SCIx_ERI_IRQ] &&	\
76 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
77 
78 enum SCI_CLKS {
79 	SCI_FCK,		/* Functional Clock */
80 	SCI_SCK,		/* Optional External Clock */
81 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
82 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
83 	SCI_NUM_CLKS
84 };
85 
86 /* Bit x set means sampling rate x + 1 is supported */
87 #define SCI_SR(x)		BIT((x) - 1)
88 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
89 
90 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
91 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
92 				SCI_SR(19) | SCI_SR(27)
93 
94 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
95 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
96 
97 /* Iterate over all supported sampling rates, from high to low */
98 #define for_each_sr(_sr, _port)						\
99 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
100 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
101 
102 struct plat_sci_reg {
103 	u8 offset, size;
104 };
105 
106 struct sci_port_params {
107 	const struct plat_sci_reg regs[SCIx_NR_REGS];
108 	unsigned int fifosize;
109 	unsigned int overrun_reg;
110 	unsigned int overrun_mask;
111 	unsigned int sampling_rate_mask;
112 	unsigned int error_mask;
113 	unsigned int error_clear;
114 };
115 
116 struct sci_port {
117 	struct uart_port	port;
118 
119 	/* Platform configuration */
120 	const struct sci_port_params *params;
121 	const struct plat_sci_port *cfg;
122 	unsigned int		sampling_rate_mask;
123 	resource_size_t		reg_size;
124 	struct mctrl_gpios	*gpios;
125 
126 	/* Clocks */
127 	struct clk		*clks[SCI_NUM_CLKS];
128 	unsigned long		clk_rates[SCI_NUM_CLKS];
129 
130 	int			irqs[SCIx_NR_IRQS];
131 	char			*irqstr[SCIx_NR_IRQS];
132 
133 	struct dma_chan			*chan_tx;
134 	struct dma_chan			*chan_rx;
135 
136 #ifdef CONFIG_SERIAL_SH_SCI_DMA
137 	struct dma_chan			*chan_tx_saved;
138 	struct dma_chan			*chan_rx_saved;
139 	dma_cookie_t			cookie_tx;
140 	dma_cookie_t			cookie_rx[2];
141 	dma_cookie_t			active_rx;
142 	dma_addr_t			tx_dma_addr;
143 	unsigned int			tx_dma_len;
144 	struct scatterlist		sg_rx[2];
145 	void				*rx_buf[2];
146 	size_t				buf_len_rx;
147 	struct work_struct		work_tx;
148 	struct hrtimer			rx_timer;
149 	unsigned int			rx_timeout;	/* microseconds */
150 #endif
151 	unsigned int			rx_frame;
152 	int				rx_trigger;
153 	struct timer_list		rx_fifo_timer;
154 	int				rx_fifo_timeout;
155 	u16				hscif_tot;
156 
157 	bool has_rtscts;
158 	bool autorts;
159 };
160 
161 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
162 
163 static struct sci_port sci_ports[SCI_NPORTS];
164 static unsigned long sci_ports_in_use;
165 static struct uart_driver sci_uart_driver;
166 
167 static inline struct sci_port *
168 to_sci_port(struct uart_port *uart)
169 {
170 	return container_of(uart, struct sci_port, port);
171 }
172 
173 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
174 	/*
175 	 * Common SCI definitions, dependent on the port's regshift
176 	 * value.
177 	 */
178 	[SCIx_SCI_REGTYPE] = {
179 		.regs = {
180 			[SCSMR]		= { 0x00,  8 },
181 			[SCBRR]		= { 0x01,  8 },
182 			[SCSCR]		= { 0x02,  8 },
183 			[SCxTDR]	= { 0x03,  8 },
184 			[SCxSR]		= { 0x04,  8 },
185 			[SCxRDR]	= { 0x05,  8 },
186 		},
187 		.fifosize = 1,
188 		.overrun_reg = SCxSR,
189 		.overrun_mask = SCI_ORER,
190 		.sampling_rate_mask = SCI_SR(32),
191 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
192 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
193 	},
194 
195 	/*
196 	 * Common definitions for legacy IrDA ports.
197 	 */
198 	[SCIx_IRDA_REGTYPE] = {
199 		.regs = {
200 			[SCSMR]		= { 0x00,  8 },
201 			[SCBRR]		= { 0x02,  8 },
202 			[SCSCR]		= { 0x04,  8 },
203 			[SCxTDR]	= { 0x06,  8 },
204 			[SCxSR]		= { 0x08, 16 },
205 			[SCxRDR]	= { 0x0a,  8 },
206 			[SCFCR]		= { 0x0c,  8 },
207 			[SCFDR]		= { 0x0e, 16 },
208 		},
209 		.fifosize = 1,
210 		.overrun_reg = SCxSR,
211 		.overrun_mask = SCI_ORER,
212 		.sampling_rate_mask = SCI_SR(32),
213 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
214 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
215 	},
216 
217 	/*
218 	 * Common SCIFA definitions.
219 	 */
220 	[SCIx_SCIFA_REGTYPE] = {
221 		.regs = {
222 			[SCSMR]		= { 0x00, 16 },
223 			[SCBRR]		= { 0x04,  8 },
224 			[SCSCR]		= { 0x08, 16 },
225 			[SCxTDR]	= { 0x20,  8 },
226 			[SCxSR]		= { 0x14, 16 },
227 			[SCxRDR]	= { 0x24,  8 },
228 			[SCFCR]		= { 0x18, 16 },
229 			[SCFDR]		= { 0x1c, 16 },
230 			[SCPCR]		= { 0x30, 16 },
231 			[SCPDR]		= { 0x34, 16 },
232 		},
233 		.fifosize = 64,
234 		.overrun_reg = SCxSR,
235 		.overrun_mask = SCIFA_ORER,
236 		.sampling_rate_mask = SCI_SR_SCIFAB,
237 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
238 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
239 	},
240 
241 	/*
242 	 * Common SCIFB definitions.
243 	 */
244 	[SCIx_SCIFB_REGTYPE] = {
245 		.regs = {
246 			[SCSMR]		= { 0x00, 16 },
247 			[SCBRR]		= { 0x04,  8 },
248 			[SCSCR]		= { 0x08, 16 },
249 			[SCxTDR]	= { 0x40,  8 },
250 			[SCxSR]		= { 0x14, 16 },
251 			[SCxRDR]	= { 0x60,  8 },
252 			[SCFCR]		= { 0x18, 16 },
253 			[SCTFDR]	= { 0x38, 16 },
254 			[SCRFDR]	= { 0x3c, 16 },
255 			[SCPCR]		= { 0x30, 16 },
256 			[SCPDR]		= { 0x34, 16 },
257 		},
258 		.fifosize = 256,
259 		.overrun_reg = SCxSR,
260 		.overrun_mask = SCIFA_ORER,
261 		.sampling_rate_mask = SCI_SR_SCIFAB,
262 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
263 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
264 	},
265 
266 	/*
267 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
268 	 * count registers.
269 	 */
270 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
271 		.regs = {
272 			[SCSMR]		= { 0x00, 16 },
273 			[SCBRR]		= { 0x04,  8 },
274 			[SCSCR]		= { 0x08, 16 },
275 			[SCxTDR]	= { 0x0c,  8 },
276 			[SCxSR]		= { 0x10, 16 },
277 			[SCxRDR]	= { 0x14,  8 },
278 			[SCFCR]		= { 0x18, 16 },
279 			[SCFDR]		= { 0x1c, 16 },
280 			[SCSPTR]	= { 0x20, 16 },
281 			[SCLSR]		= { 0x24, 16 },
282 		},
283 		.fifosize = 16,
284 		.overrun_reg = SCLSR,
285 		.overrun_mask = SCLSR_ORER,
286 		.sampling_rate_mask = SCI_SR(32),
287 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
288 		.error_clear = SCIF_ERROR_CLEAR,
289 	},
290 
291 	/*
292 	 * The "SCIFA" that is in RZ/T and RZ/A2.
293 	 * It looks like a normal SCIF with FIFO data, but with a
294 	 * compressed address space. Also, the break out of interrupts
295 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
296 	 */
297 	[SCIx_RZ_SCIFA_REGTYPE] = {
298 		.regs = {
299 			[SCSMR]		= { 0x00, 16 },
300 			[SCBRR]		= { 0x02,  8 },
301 			[SCSCR]		= { 0x04, 16 },
302 			[SCxTDR]	= { 0x06,  8 },
303 			[SCxSR]		= { 0x08, 16 },
304 			[SCxRDR]	= { 0x0A,  8 },
305 			[SCFCR]		= { 0x0C, 16 },
306 			[SCFDR]		= { 0x0E, 16 },
307 			[SCSPTR]	= { 0x10, 16 },
308 			[SCLSR]		= { 0x12, 16 },
309 		},
310 		.fifosize = 16,
311 		.overrun_reg = SCLSR,
312 		.overrun_mask = SCLSR_ORER,
313 		.sampling_rate_mask = SCI_SR(32),
314 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
315 		.error_clear = SCIF_ERROR_CLEAR,
316 	},
317 
318 	/*
319 	 * Common SH-3 SCIF definitions.
320 	 */
321 	[SCIx_SH3_SCIF_REGTYPE] = {
322 		.regs = {
323 			[SCSMR]		= { 0x00,  8 },
324 			[SCBRR]		= { 0x02,  8 },
325 			[SCSCR]		= { 0x04,  8 },
326 			[SCxTDR]	= { 0x06,  8 },
327 			[SCxSR]		= { 0x08, 16 },
328 			[SCxRDR]	= { 0x0a,  8 },
329 			[SCFCR]		= { 0x0c,  8 },
330 			[SCFDR]		= { 0x0e, 16 },
331 		},
332 		.fifosize = 16,
333 		.overrun_reg = SCLSR,
334 		.overrun_mask = SCLSR_ORER,
335 		.sampling_rate_mask = SCI_SR(32),
336 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
337 		.error_clear = SCIF_ERROR_CLEAR,
338 	},
339 
340 	/*
341 	 * Common SH-4(A) SCIF(B) definitions.
342 	 */
343 	[SCIx_SH4_SCIF_REGTYPE] = {
344 		.regs = {
345 			[SCSMR]		= { 0x00, 16 },
346 			[SCBRR]		= { 0x04,  8 },
347 			[SCSCR]		= { 0x08, 16 },
348 			[SCxTDR]	= { 0x0c,  8 },
349 			[SCxSR]		= { 0x10, 16 },
350 			[SCxRDR]	= { 0x14,  8 },
351 			[SCFCR]		= { 0x18, 16 },
352 			[SCFDR]		= { 0x1c, 16 },
353 			[SCSPTR]	= { 0x20, 16 },
354 			[SCLSR]		= { 0x24, 16 },
355 		},
356 		.fifosize = 16,
357 		.overrun_reg = SCLSR,
358 		.overrun_mask = SCLSR_ORER,
359 		.sampling_rate_mask = SCI_SR(32),
360 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
361 		.error_clear = SCIF_ERROR_CLEAR,
362 	},
363 
364 	/*
365 	 * Common SCIF definitions for ports with a Baud Rate Generator for
366 	 * External Clock (BRG).
367 	 */
368 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
369 		.regs = {
370 			[SCSMR]		= { 0x00, 16 },
371 			[SCBRR]		= { 0x04,  8 },
372 			[SCSCR]		= { 0x08, 16 },
373 			[SCxTDR]	= { 0x0c,  8 },
374 			[SCxSR]		= { 0x10, 16 },
375 			[SCxRDR]	= { 0x14,  8 },
376 			[SCFCR]		= { 0x18, 16 },
377 			[SCFDR]		= { 0x1c, 16 },
378 			[SCSPTR]	= { 0x20, 16 },
379 			[SCLSR]		= { 0x24, 16 },
380 			[SCDL]		= { 0x30, 16 },
381 			[SCCKS]		= { 0x34, 16 },
382 		},
383 		.fifosize = 16,
384 		.overrun_reg = SCLSR,
385 		.overrun_mask = SCLSR_ORER,
386 		.sampling_rate_mask = SCI_SR(32),
387 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
388 		.error_clear = SCIF_ERROR_CLEAR,
389 	},
390 
391 	/*
392 	 * Common HSCIF definitions.
393 	 */
394 	[SCIx_HSCIF_REGTYPE] = {
395 		.regs = {
396 			[SCSMR]		= { 0x00, 16 },
397 			[SCBRR]		= { 0x04,  8 },
398 			[SCSCR]		= { 0x08, 16 },
399 			[SCxTDR]	= { 0x0c,  8 },
400 			[SCxSR]		= { 0x10, 16 },
401 			[SCxRDR]	= { 0x14,  8 },
402 			[SCFCR]		= { 0x18, 16 },
403 			[SCFDR]		= { 0x1c, 16 },
404 			[SCSPTR]	= { 0x20, 16 },
405 			[SCLSR]		= { 0x24, 16 },
406 			[HSSRR]		= { 0x40, 16 },
407 			[SCDL]		= { 0x30, 16 },
408 			[SCCKS]		= { 0x34, 16 },
409 			[HSRTRGR]	= { 0x54, 16 },
410 			[HSTTRGR]	= { 0x58, 16 },
411 		},
412 		.fifosize = 128,
413 		.overrun_reg = SCLSR,
414 		.overrun_mask = SCLSR_ORER,
415 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
416 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
417 		.error_clear = SCIF_ERROR_CLEAR,
418 	},
419 
420 	/*
421 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
422 	 * register.
423 	 */
424 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
425 		.regs = {
426 			[SCSMR]		= { 0x00, 16 },
427 			[SCBRR]		= { 0x04,  8 },
428 			[SCSCR]		= { 0x08, 16 },
429 			[SCxTDR]	= { 0x0c,  8 },
430 			[SCxSR]		= { 0x10, 16 },
431 			[SCxRDR]	= { 0x14,  8 },
432 			[SCFCR]		= { 0x18, 16 },
433 			[SCFDR]		= { 0x1c, 16 },
434 			[SCLSR]		= { 0x24, 16 },
435 		},
436 		.fifosize = 16,
437 		.overrun_reg = SCLSR,
438 		.overrun_mask = SCLSR_ORER,
439 		.sampling_rate_mask = SCI_SR(32),
440 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
441 		.error_clear = SCIF_ERROR_CLEAR,
442 	},
443 
444 	/*
445 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
446 	 * count registers.
447 	 */
448 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
449 		.regs = {
450 			[SCSMR]		= { 0x00, 16 },
451 			[SCBRR]		= { 0x04,  8 },
452 			[SCSCR]		= { 0x08, 16 },
453 			[SCxTDR]	= { 0x0c,  8 },
454 			[SCxSR]		= { 0x10, 16 },
455 			[SCxRDR]	= { 0x14,  8 },
456 			[SCFCR]		= { 0x18, 16 },
457 			[SCFDR]		= { 0x1c, 16 },
458 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
459 			[SCRFDR]	= { 0x20, 16 },
460 			[SCSPTR]	= { 0x24, 16 },
461 			[SCLSR]		= { 0x28, 16 },
462 		},
463 		.fifosize = 16,
464 		.overrun_reg = SCLSR,
465 		.overrun_mask = SCLSR_ORER,
466 		.sampling_rate_mask = SCI_SR(32),
467 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
468 		.error_clear = SCIF_ERROR_CLEAR,
469 	},
470 
471 	/*
472 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
473 	 * registers.
474 	 */
475 	[SCIx_SH7705_SCIF_REGTYPE] = {
476 		.regs = {
477 			[SCSMR]		= { 0x00, 16 },
478 			[SCBRR]		= { 0x04,  8 },
479 			[SCSCR]		= { 0x08, 16 },
480 			[SCxTDR]	= { 0x20,  8 },
481 			[SCxSR]		= { 0x14, 16 },
482 			[SCxRDR]	= { 0x24,  8 },
483 			[SCFCR]		= { 0x18, 16 },
484 			[SCFDR]		= { 0x1c, 16 },
485 		},
486 		.fifosize = 64,
487 		.overrun_reg = SCxSR,
488 		.overrun_mask = SCIFA_ORER,
489 		.sampling_rate_mask = SCI_SR(16),
490 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
491 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
492 	},
493 };
494 
495 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
496 
497 /*
498  * The "offset" here is rather misleading, in that it refers to an enum
499  * value relative to the port mapping rather than the fixed offset
500  * itself, which needs to be manually retrieved from the platform's
501  * register map for the given port.
502  */
503 static unsigned int sci_serial_in(struct uart_port *p, int offset)
504 {
505 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
506 
507 	if (reg->size == 8)
508 		return ioread8(p->membase + (reg->offset << p->regshift));
509 	else if (reg->size == 16)
510 		return ioread16(p->membase + (reg->offset << p->regshift));
511 	else
512 		WARN(1, "Invalid register access\n");
513 
514 	return 0;
515 }
516 
517 static void sci_serial_out(struct uart_port *p, int offset, int value)
518 {
519 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
520 
521 	if (reg->size == 8)
522 		iowrite8(value, p->membase + (reg->offset << p->regshift));
523 	else if (reg->size == 16)
524 		iowrite16(value, p->membase + (reg->offset << p->regshift));
525 	else
526 		WARN(1, "Invalid register access\n");
527 }
528 
529 static void sci_port_enable(struct sci_port *sci_port)
530 {
531 	unsigned int i;
532 
533 	if (!sci_port->port.dev)
534 		return;
535 
536 	pm_runtime_get_sync(sci_port->port.dev);
537 
538 	for (i = 0; i < SCI_NUM_CLKS; i++) {
539 		clk_prepare_enable(sci_port->clks[i]);
540 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
541 	}
542 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
543 }
544 
545 static void sci_port_disable(struct sci_port *sci_port)
546 {
547 	unsigned int i;
548 
549 	if (!sci_port->port.dev)
550 		return;
551 
552 	for (i = SCI_NUM_CLKS; i-- > 0; )
553 		clk_disable_unprepare(sci_port->clks[i]);
554 
555 	pm_runtime_put_sync(sci_port->port.dev);
556 }
557 
558 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
559 {
560 	/*
561 	 * Not all ports (such as SCIFA) will support REIE. Rather than
562 	 * special-casing the port type, we check the port initialization
563 	 * IRQ enable mask to see whether the IRQ is desired at all. If
564 	 * it's unset, it's logically inferred that there's no point in
565 	 * testing for it.
566 	 */
567 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
568 }
569 
570 static void sci_start_tx(struct uart_port *port)
571 {
572 	struct sci_port *s = to_sci_port(port);
573 	unsigned short ctrl;
574 
575 #ifdef CONFIG_SERIAL_SH_SCI_DMA
576 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
577 		u16 new, scr = serial_port_in(port, SCSCR);
578 		if (s->chan_tx)
579 			new = scr | SCSCR_TDRQE;
580 		else
581 			new = scr & ~SCSCR_TDRQE;
582 		if (new != scr)
583 			serial_port_out(port, SCSCR, new);
584 	}
585 
586 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
587 	    dma_submit_error(s->cookie_tx)) {
588 		s->cookie_tx = 0;
589 		schedule_work(&s->work_tx);
590 	}
591 #endif
592 
593 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
594 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
595 		ctrl = serial_port_in(port, SCSCR);
596 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
597 	}
598 }
599 
600 static void sci_stop_tx(struct uart_port *port)
601 {
602 	unsigned short ctrl;
603 
604 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
605 	ctrl = serial_port_in(port, SCSCR);
606 
607 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
608 		ctrl &= ~SCSCR_TDRQE;
609 
610 	ctrl &= ~SCSCR_TIE;
611 
612 	serial_port_out(port, SCSCR, ctrl);
613 }
614 
615 static void sci_start_rx(struct uart_port *port)
616 {
617 	unsigned short ctrl;
618 
619 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
620 
621 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
622 		ctrl &= ~SCSCR_RDRQE;
623 
624 	serial_port_out(port, SCSCR, ctrl);
625 }
626 
627 static void sci_stop_rx(struct uart_port *port)
628 {
629 	unsigned short ctrl;
630 
631 	ctrl = serial_port_in(port, SCSCR);
632 
633 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
634 		ctrl &= ~SCSCR_RDRQE;
635 
636 	ctrl &= ~port_rx_irq_mask(port);
637 
638 	serial_port_out(port, SCSCR, ctrl);
639 }
640 
641 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
642 {
643 	if (port->type == PORT_SCI) {
644 		/* Just store the mask */
645 		serial_port_out(port, SCxSR, mask);
646 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
647 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
648 		/* Only clear the status bits we want to clear */
649 		serial_port_out(port, SCxSR,
650 				serial_port_in(port, SCxSR) & mask);
651 	} else {
652 		/* Store the mask, clear parity/framing errors */
653 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
654 	}
655 }
656 
657 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
658     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
659 
660 #ifdef CONFIG_CONSOLE_POLL
661 static int sci_poll_get_char(struct uart_port *port)
662 {
663 	unsigned short status;
664 	int c;
665 
666 	do {
667 		status = serial_port_in(port, SCxSR);
668 		if (status & SCxSR_ERRORS(port)) {
669 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
670 			continue;
671 		}
672 		break;
673 	} while (1);
674 
675 	if (!(status & SCxSR_RDxF(port)))
676 		return NO_POLL_CHAR;
677 
678 	c = serial_port_in(port, SCxRDR);
679 
680 	/* Dummy read */
681 	serial_port_in(port, SCxSR);
682 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
683 
684 	return c;
685 }
686 #endif
687 
688 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
689 {
690 	unsigned short status;
691 
692 	do {
693 		status = serial_port_in(port, SCxSR);
694 	} while (!(status & SCxSR_TDxE(port)));
695 
696 	serial_port_out(port, SCxTDR, c);
697 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
698 }
699 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
700 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
701 
702 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
703 {
704 	struct sci_port *s = to_sci_port(port);
705 
706 	/*
707 	 * Use port-specific handler if provided.
708 	 */
709 	if (s->cfg->ops && s->cfg->ops->init_pins) {
710 		s->cfg->ops->init_pins(port, cflag);
711 		return;
712 	}
713 
714 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
715 		u16 data = serial_port_in(port, SCPDR);
716 		u16 ctrl = serial_port_in(port, SCPCR);
717 
718 		/* Enable RXD and TXD pin functions */
719 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
720 		if (to_sci_port(port)->has_rtscts) {
721 			/* RTS# is output, active low, unless autorts */
722 			if (!(port->mctrl & TIOCM_RTS)) {
723 				ctrl |= SCPCR_RTSC;
724 				data |= SCPDR_RTSD;
725 			} else if (!s->autorts) {
726 				ctrl |= SCPCR_RTSC;
727 				data &= ~SCPDR_RTSD;
728 			} else {
729 				/* Enable RTS# pin function */
730 				ctrl &= ~SCPCR_RTSC;
731 			}
732 			/* Enable CTS# pin function */
733 			ctrl &= ~SCPCR_CTSC;
734 		}
735 		serial_port_out(port, SCPDR, data);
736 		serial_port_out(port, SCPCR, ctrl);
737 	} else if (sci_getreg(port, SCSPTR)->size) {
738 		u16 status = serial_port_in(port, SCSPTR);
739 
740 		/* RTS# is always output; and active low, unless autorts */
741 		status |= SCSPTR_RTSIO;
742 		if (!(port->mctrl & TIOCM_RTS))
743 			status |= SCSPTR_RTSDT;
744 		else if (!s->autorts)
745 			status &= ~SCSPTR_RTSDT;
746 		/* CTS# and SCK are inputs */
747 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
748 		serial_port_out(port, SCSPTR, status);
749 	}
750 }
751 
752 static int sci_txfill(struct uart_port *port)
753 {
754 	struct sci_port *s = to_sci_port(port);
755 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
756 	const struct plat_sci_reg *reg;
757 
758 	reg = sci_getreg(port, SCTFDR);
759 	if (reg->size)
760 		return serial_port_in(port, SCTFDR) & fifo_mask;
761 
762 	reg = sci_getreg(port, SCFDR);
763 	if (reg->size)
764 		return serial_port_in(port, SCFDR) >> 8;
765 
766 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
767 }
768 
769 static int sci_txroom(struct uart_port *port)
770 {
771 	return port->fifosize - sci_txfill(port);
772 }
773 
774 static int sci_rxfill(struct uart_port *port)
775 {
776 	struct sci_port *s = to_sci_port(port);
777 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
778 	const struct plat_sci_reg *reg;
779 
780 	reg = sci_getreg(port, SCRFDR);
781 	if (reg->size)
782 		return serial_port_in(port, SCRFDR) & fifo_mask;
783 
784 	reg = sci_getreg(port, SCFDR);
785 	if (reg->size)
786 		return serial_port_in(port, SCFDR) & fifo_mask;
787 
788 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
789 }
790 
791 /* ********************************************************************** *
792  *                   the interrupt related routines                       *
793  * ********************************************************************** */
794 
795 static void sci_transmit_chars(struct uart_port *port)
796 {
797 	struct circ_buf *xmit = &port->state->xmit;
798 	unsigned int stopped = uart_tx_stopped(port);
799 	unsigned short status;
800 	unsigned short ctrl;
801 	int count;
802 
803 	status = serial_port_in(port, SCxSR);
804 	if (!(status & SCxSR_TDxE(port))) {
805 		ctrl = serial_port_in(port, SCSCR);
806 		if (uart_circ_empty(xmit))
807 			ctrl &= ~SCSCR_TIE;
808 		else
809 			ctrl |= SCSCR_TIE;
810 		serial_port_out(port, SCSCR, ctrl);
811 		return;
812 	}
813 
814 	count = sci_txroom(port);
815 
816 	do {
817 		unsigned char c;
818 
819 		if (port->x_char) {
820 			c = port->x_char;
821 			port->x_char = 0;
822 		} else if (!uart_circ_empty(xmit) && !stopped) {
823 			c = xmit->buf[xmit->tail];
824 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
825 		} else {
826 			break;
827 		}
828 
829 		serial_port_out(port, SCxTDR, c);
830 
831 		port->icount.tx++;
832 	} while (--count > 0);
833 
834 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
835 
836 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
837 		uart_write_wakeup(port);
838 	if (uart_circ_empty(xmit))
839 		sci_stop_tx(port);
840 
841 }
842 
843 /* On SH3, SCIF may read end-of-break as a space->mark char */
844 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
845 
846 static void sci_receive_chars(struct uart_port *port)
847 {
848 	struct tty_port *tport = &port->state->port;
849 	int i, count, copied = 0;
850 	unsigned short status;
851 	unsigned char flag;
852 
853 	status = serial_port_in(port, SCxSR);
854 	if (!(status & SCxSR_RDxF(port)))
855 		return;
856 
857 	while (1) {
858 		/* Don't copy more bytes than there is room for in the buffer */
859 		count = tty_buffer_request_room(tport, sci_rxfill(port));
860 
861 		/* If for any reason we can't copy more data, we're done! */
862 		if (count == 0)
863 			break;
864 
865 		if (port->type == PORT_SCI) {
866 			char c = serial_port_in(port, SCxRDR);
867 			if (uart_handle_sysrq_char(port, c))
868 				count = 0;
869 			else
870 				tty_insert_flip_char(tport, c, TTY_NORMAL);
871 		} else {
872 			for (i = 0; i < count; i++) {
873 				char c;
874 
875 				if (port->type == PORT_SCIF ||
876 				    port->type == PORT_HSCIF) {
877 					status = serial_port_in(port, SCxSR);
878 					c = serial_port_in(port, SCxRDR);
879 				} else {
880 					c = serial_port_in(port, SCxRDR);
881 					status = serial_port_in(port, SCxSR);
882 				}
883 				if (uart_handle_sysrq_char(port, c)) {
884 					count--; i--;
885 					continue;
886 				}
887 
888 				/* Store data and status */
889 				if (status & SCxSR_FER(port)) {
890 					flag = TTY_FRAME;
891 					port->icount.frame++;
892 					dev_notice(port->dev, "frame error\n");
893 				} else if (status & SCxSR_PER(port)) {
894 					flag = TTY_PARITY;
895 					port->icount.parity++;
896 					dev_notice(port->dev, "parity error\n");
897 				} else
898 					flag = TTY_NORMAL;
899 
900 				tty_insert_flip_char(tport, c, flag);
901 			}
902 		}
903 
904 		serial_port_in(port, SCxSR); /* dummy read */
905 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
906 
907 		copied += count;
908 		port->icount.rx += count;
909 	}
910 
911 	if (copied) {
912 		/* Tell the rest of the system the news. New characters! */
913 		tty_flip_buffer_push(tport);
914 	} else {
915 		/* TTY buffers full; read from RX reg to prevent lockup */
916 		serial_port_in(port, SCxRDR);
917 		serial_port_in(port, SCxSR); /* dummy read */
918 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
919 	}
920 }
921 
922 static int sci_handle_errors(struct uart_port *port)
923 {
924 	int copied = 0;
925 	unsigned short status = serial_port_in(port, SCxSR);
926 	struct tty_port *tport = &port->state->port;
927 	struct sci_port *s = to_sci_port(port);
928 
929 	/* Handle overruns */
930 	if (status & s->params->overrun_mask) {
931 		port->icount.overrun++;
932 
933 		/* overrun error */
934 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
935 			copied++;
936 
937 		dev_notice(port->dev, "overrun error\n");
938 	}
939 
940 	if (status & SCxSR_FER(port)) {
941 		/* frame error */
942 		port->icount.frame++;
943 
944 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
945 			copied++;
946 
947 		dev_notice(port->dev, "frame error\n");
948 	}
949 
950 	if (status & SCxSR_PER(port)) {
951 		/* parity error */
952 		port->icount.parity++;
953 
954 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
955 			copied++;
956 
957 		dev_notice(port->dev, "parity error\n");
958 	}
959 
960 	if (copied)
961 		tty_flip_buffer_push(tport);
962 
963 	return copied;
964 }
965 
966 static int sci_handle_fifo_overrun(struct uart_port *port)
967 {
968 	struct tty_port *tport = &port->state->port;
969 	struct sci_port *s = to_sci_port(port);
970 	const struct plat_sci_reg *reg;
971 	int copied = 0;
972 	u16 status;
973 
974 	reg = sci_getreg(port, s->params->overrun_reg);
975 	if (!reg->size)
976 		return 0;
977 
978 	status = serial_port_in(port, s->params->overrun_reg);
979 	if (status & s->params->overrun_mask) {
980 		status &= ~s->params->overrun_mask;
981 		serial_port_out(port, s->params->overrun_reg, status);
982 
983 		port->icount.overrun++;
984 
985 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
986 		tty_flip_buffer_push(tport);
987 
988 		dev_dbg(port->dev, "overrun error\n");
989 		copied++;
990 	}
991 
992 	return copied;
993 }
994 
995 static int sci_handle_breaks(struct uart_port *port)
996 {
997 	int copied = 0;
998 	unsigned short status = serial_port_in(port, SCxSR);
999 	struct tty_port *tport = &port->state->port;
1000 
1001 	if (uart_handle_break(port))
1002 		return 0;
1003 
1004 	if (status & SCxSR_BRK(port)) {
1005 		port->icount.brk++;
1006 
1007 		/* Notify of BREAK */
1008 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1009 			copied++;
1010 
1011 		dev_dbg(port->dev, "BREAK detected\n");
1012 	}
1013 
1014 	if (copied)
1015 		tty_flip_buffer_push(tport);
1016 
1017 	copied += sci_handle_fifo_overrun(port);
1018 
1019 	return copied;
1020 }
1021 
1022 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1023 {
1024 	unsigned int bits;
1025 
1026 	if (rx_trig < 1)
1027 		rx_trig = 1;
1028 	if (rx_trig >= port->fifosize)
1029 		rx_trig = port->fifosize;
1030 
1031 	/* HSCIF can be set to an arbitrary level. */
1032 	if (sci_getreg(port, HSRTRGR)->size) {
1033 		serial_port_out(port, HSRTRGR, rx_trig);
1034 		return rx_trig;
1035 	}
1036 
1037 	switch (port->type) {
1038 	case PORT_SCIF:
1039 		if (rx_trig < 4) {
1040 			bits = 0;
1041 			rx_trig = 1;
1042 		} else if (rx_trig < 8) {
1043 			bits = SCFCR_RTRG0;
1044 			rx_trig = 4;
1045 		} else if (rx_trig < 14) {
1046 			bits = SCFCR_RTRG1;
1047 			rx_trig = 8;
1048 		} else {
1049 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1050 			rx_trig = 14;
1051 		}
1052 		break;
1053 	case PORT_SCIFA:
1054 	case PORT_SCIFB:
1055 		if (rx_trig < 16) {
1056 			bits = 0;
1057 			rx_trig = 1;
1058 		} else if (rx_trig < 32) {
1059 			bits = SCFCR_RTRG0;
1060 			rx_trig = 16;
1061 		} else if (rx_trig < 48) {
1062 			bits = SCFCR_RTRG1;
1063 			rx_trig = 32;
1064 		} else {
1065 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1066 			rx_trig = 48;
1067 		}
1068 		break;
1069 	default:
1070 		WARN(1, "unknown FIFO configuration");
1071 		return 1;
1072 	}
1073 
1074 	serial_port_out(port, SCFCR,
1075 		(serial_port_in(port, SCFCR) &
1076 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1077 
1078 	return rx_trig;
1079 }
1080 
1081 static int scif_rtrg_enabled(struct uart_port *port)
1082 {
1083 	if (sci_getreg(port, HSRTRGR)->size)
1084 		return serial_port_in(port, HSRTRGR) != 0;
1085 	else
1086 		return (serial_port_in(port, SCFCR) &
1087 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1088 }
1089 
1090 static void rx_fifo_timer_fn(struct timer_list *t)
1091 {
1092 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1093 	struct uart_port *port = &s->port;
1094 
1095 	dev_dbg(port->dev, "Rx timed out\n");
1096 	scif_set_rtrg(port, 1);
1097 }
1098 
1099 static ssize_t rx_fifo_trigger_show(struct device *dev,
1100 				    struct device_attribute *attr, char *buf)
1101 {
1102 	struct uart_port *port = dev_get_drvdata(dev);
1103 	struct sci_port *sci = to_sci_port(port);
1104 
1105 	return sprintf(buf, "%d\n", sci->rx_trigger);
1106 }
1107 
1108 static ssize_t rx_fifo_trigger_store(struct device *dev,
1109 				     struct device_attribute *attr,
1110 				     const char *buf, size_t count)
1111 {
1112 	struct uart_port *port = dev_get_drvdata(dev);
1113 	struct sci_port *sci = to_sci_port(port);
1114 	int ret;
1115 	long r;
1116 
1117 	ret = kstrtol(buf, 0, &r);
1118 	if (ret)
1119 		return ret;
1120 
1121 	sci->rx_trigger = scif_set_rtrg(port, r);
1122 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1123 		scif_set_rtrg(port, 1);
1124 
1125 	return count;
1126 }
1127 
1128 static DEVICE_ATTR_RW(rx_fifo_trigger);
1129 
1130 static ssize_t rx_fifo_timeout_show(struct device *dev,
1131 			       struct device_attribute *attr,
1132 			       char *buf)
1133 {
1134 	struct uart_port *port = dev_get_drvdata(dev);
1135 	struct sci_port *sci = to_sci_port(port);
1136 	int v;
1137 
1138 	if (port->type == PORT_HSCIF)
1139 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1140 	else
1141 		v = sci->rx_fifo_timeout;
1142 
1143 	return sprintf(buf, "%d\n", v);
1144 }
1145 
1146 static ssize_t rx_fifo_timeout_store(struct device *dev,
1147 				struct device_attribute *attr,
1148 				const char *buf,
1149 				size_t count)
1150 {
1151 	struct uart_port *port = dev_get_drvdata(dev);
1152 	struct sci_port *sci = to_sci_port(port);
1153 	int ret;
1154 	long r;
1155 
1156 	ret = kstrtol(buf, 0, &r);
1157 	if (ret)
1158 		return ret;
1159 
1160 	if (port->type == PORT_HSCIF) {
1161 		if (r < 0 || r > 3)
1162 			return -EINVAL;
1163 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1164 	} else {
1165 		sci->rx_fifo_timeout = r;
1166 		scif_set_rtrg(port, 1);
1167 		if (r > 0)
1168 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1169 	}
1170 
1171 	return count;
1172 }
1173 
1174 static DEVICE_ATTR_RW(rx_fifo_timeout);
1175 
1176 
1177 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1178 static void sci_dma_tx_complete(void *arg)
1179 {
1180 	struct sci_port *s = arg;
1181 	struct uart_port *port = &s->port;
1182 	struct circ_buf *xmit = &port->state->xmit;
1183 	unsigned long flags;
1184 
1185 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1186 
1187 	spin_lock_irqsave(&port->lock, flags);
1188 
1189 	xmit->tail += s->tx_dma_len;
1190 	xmit->tail &= UART_XMIT_SIZE - 1;
1191 
1192 	port->icount.tx += s->tx_dma_len;
1193 
1194 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1195 		uart_write_wakeup(port);
1196 
1197 	if (!uart_circ_empty(xmit)) {
1198 		s->cookie_tx = 0;
1199 		schedule_work(&s->work_tx);
1200 	} else {
1201 		s->cookie_tx = -EINVAL;
1202 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1203 			u16 ctrl = serial_port_in(port, SCSCR);
1204 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1205 		}
1206 	}
1207 
1208 	spin_unlock_irqrestore(&port->lock, flags);
1209 }
1210 
1211 /* Locking: called with port lock held */
1212 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1213 {
1214 	struct uart_port *port = &s->port;
1215 	struct tty_port *tport = &port->state->port;
1216 	int copied;
1217 
1218 	copied = tty_insert_flip_string(tport, buf, count);
1219 	if (copied < count)
1220 		port->icount.buf_overrun++;
1221 
1222 	port->icount.rx += copied;
1223 
1224 	return copied;
1225 }
1226 
1227 static int sci_dma_rx_find_active(struct sci_port *s)
1228 {
1229 	unsigned int i;
1230 
1231 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1232 		if (s->active_rx == s->cookie_rx[i])
1233 			return i;
1234 
1235 	return -1;
1236 }
1237 
1238 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1239 {
1240 	unsigned int i;
1241 
1242 	s->chan_rx = NULL;
1243 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1244 		s->cookie_rx[i] = -EINVAL;
1245 	s->active_rx = 0;
1246 }
1247 
1248 static void sci_dma_rx_release(struct sci_port *s)
1249 {
1250 	struct dma_chan *chan = s->chan_rx_saved;
1251 
1252 	s->chan_rx_saved = NULL;
1253 	sci_dma_rx_chan_invalidate(s);
1254 	dmaengine_terminate_sync(chan);
1255 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1256 			  sg_dma_address(&s->sg_rx[0]));
1257 	dma_release_channel(chan);
1258 }
1259 
1260 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1261 {
1262 	long sec = usec / 1000000;
1263 	long nsec = (usec % 1000000) * 1000;
1264 	ktime_t t = ktime_set(sec, nsec);
1265 
1266 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1267 }
1268 
1269 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1270 {
1271 	struct uart_port *port = &s->port;
1272 	u16 scr;
1273 
1274 	/* Direct new serial port interrupts back to CPU */
1275 	scr = serial_port_in(port, SCSCR);
1276 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1277 		scr &= ~SCSCR_RDRQE;
1278 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1279 	}
1280 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1281 }
1282 
1283 static void sci_dma_rx_complete(void *arg)
1284 {
1285 	struct sci_port *s = arg;
1286 	struct dma_chan *chan = s->chan_rx;
1287 	struct uart_port *port = &s->port;
1288 	struct dma_async_tx_descriptor *desc;
1289 	unsigned long flags;
1290 	int active, count = 0;
1291 
1292 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1293 		s->active_rx);
1294 
1295 	spin_lock_irqsave(&port->lock, flags);
1296 
1297 	active = sci_dma_rx_find_active(s);
1298 	if (active >= 0)
1299 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1300 
1301 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1302 
1303 	if (count)
1304 		tty_flip_buffer_push(&port->state->port);
1305 
1306 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1307 				       DMA_DEV_TO_MEM,
1308 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1309 	if (!desc)
1310 		goto fail;
1311 
1312 	desc->callback = sci_dma_rx_complete;
1313 	desc->callback_param = s;
1314 	s->cookie_rx[active] = dmaengine_submit(desc);
1315 	if (dma_submit_error(s->cookie_rx[active]))
1316 		goto fail;
1317 
1318 	s->active_rx = s->cookie_rx[!active];
1319 
1320 	dma_async_issue_pending(chan);
1321 
1322 	spin_unlock_irqrestore(&port->lock, flags);
1323 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1324 		__func__, s->cookie_rx[active], active, s->active_rx);
1325 	return;
1326 
1327 fail:
1328 	spin_unlock_irqrestore(&port->lock, flags);
1329 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1330 	/* Switch to PIO */
1331 	spin_lock_irqsave(&port->lock, flags);
1332 	dmaengine_terminate_async(chan);
1333 	sci_dma_rx_chan_invalidate(s);
1334 	sci_dma_rx_reenable_irq(s);
1335 	spin_unlock_irqrestore(&port->lock, flags);
1336 }
1337 
1338 static void sci_dma_tx_release(struct sci_port *s)
1339 {
1340 	struct dma_chan *chan = s->chan_tx_saved;
1341 
1342 	cancel_work_sync(&s->work_tx);
1343 	s->chan_tx_saved = s->chan_tx = NULL;
1344 	s->cookie_tx = -EINVAL;
1345 	dmaengine_terminate_sync(chan);
1346 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1347 			 DMA_TO_DEVICE);
1348 	dma_release_channel(chan);
1349 }
1350 
1351 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1352 {
1353 	struct dma_chan *chan = s->chan_rx;
1354 	struct uart_port *port = &s->port;
1355 	unsigned long flags;
1356 	int i;
1357 
1358 	for (i = 0; i < 2; i++) {
1359 		struct scatterlist *sg = &s->sg_rx[i];
1360 		struct dma_async_tx_descriptor *desc;
1361 
1362 		desc = dmaengine_prep_slave_sg(chan,
1363 			sg, 1, DMA_DEV_TO_MEM,
1364 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1365 		if (!desc)
1366 			goto fail;
1367 
1368 		desc->callback = sci_dma_rx_complete;
1369 		desc->callback_param = s;
1370 		s->cookie_rx[i] = dmaengine_submit(desc);
1371 		if (dma_submit_error(s->cookie_rx[i]))
1372 			goto fail;
1373 
1374 	}
1375 
1376 	s->active_rx = s->cookie_rx[0];
1377 
1378 	dma_async_issue_pending(chan);
1379 	return 0;
1380 
1381 fail:
1382 	/* Switch to PIO */
1383 	if (!port_lock_held)
1384 		spin_lock_irqsave(&port->lock, flags);
1385 	if (i)
1386 		dmaengine_terminate_async(chan);
1387 	sci_dma_rx_chan_invalidate(s);
1388 	sci_start_rx(port);
1389 	if (!port_lock_held)
1390 		spin_unlock_irqrestore(&port->lock, flags);
1391 	return -EAGAIN;
1392 }
1393 
1394 static void sci_dma_tx_work_fn(struct work_struct *work)
1395 {
1396 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1397 	struct dma_async_tx_descriptor *desc;
1398 	struct dma_chan *chan = s->chan_tx;
1399 	struct uart_port *port = &s->port;
1400 	struct circ_buf *xmit = &port->state->xmit;
1401 	unsigned long flags;
1402 	dma_addr_t buf;
1403 	int head, tail;
1404 
1405 	/*
1406 	 * DMA is idle now.
1407 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1408 	 * offsets and lengths. Since it is a circular buffer, we have to
1409 	 * transmit till the end, and then the rest. Take the port lock to get a
1410 	 * consistent xmit buffer state.
1411 	 */
1412 	spin_lock_irq(&port->lock);
1413 	head = xmit->head;
1414 	tail = xmit->tail;
1415 	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1416 	s->tx_dma_len = min_t(unsigned int,
1417 		CIRC_CNT(head, tail, UART_XMIT_SIZE),
1418 		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1419 	if (!s->tx_dma_len) {
1420 		/* Transmit buffer has been flushed */
1421 		spin_unlock_irq(&port->lock);
1422 		return;
1423 	}
1424 
1425 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1426 					   DMA_MEM_TO_DEV,
1427 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1428 	if (!desc) {
1429 		spin_unlock_irq(&port->lock);
1430 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1431 		goto switch_to_pio;
1432 	}
1433 
1434 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1435 				   DMA_TO_DEVICE);
1436 
1437 	desc->callback = sci_dma_tx_complete;
1438 	desc->callback_param = s;
1439 	s->cookie_tx = dmaengine_submit(desc);
1440 	if (dma_submit_error(s->cookie_tx)) {
1441 		spin_unlock_irq(&port->lock);
1442 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1443 		goto switch_to_pio;
1444 	}
1445 
1446 	spin_unlock_irq(&port->lock);
1447 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1448 		__func__, xmit->buf, tail, head, s->cookie_tx);
1449 
1450 	dma_async_issue_pending(chan);
1451 	return;
1452 
1453 switch_to_pio:
1454 	spin_lock_irqsave(&port->lock, flags);
1455 	s->chan_tx = NULL;
1456 	sci_start_tx(port);
1457 	spin_unlock_irqrestore(&port->lock, flags);
1458 	return;
1459 }
1460 
1461 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1462 {
1463 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1464 	struct dma_chan *chan = s->chan_rx;
1465 	struct uart_port *port = &s->port;
1466 	struct dma_tx_state state;
1467 	enum dma_status status;
1468 	unsigned long flags;
1469 	unsigned int read;
1470 	int active, count;
1471 
1472 	dev_dbg(port->dev, "DMA Rx timed out\n");
1473 
1474 	spin_lock_irqsave(&port->lock, flags);
1475 
1476 	active = sci_dma_rx_find_active(s);
1477 	if (active < 0) {
1478 		spin_unlock_irqrestore(&port->lock, flags);
1479 		return HRTIMER_NORESTART;
1480 	}
1481 
1482 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1483 	if (status == DMA_COMPLETE) {
1484 		spin_unlock_irqrestore(&port->lock, flags);
1485 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1486 			s->active_rx, active);
1487 
1488 		/* Let packet complete handler take care of the packet */
1489 		return HRTIMER_NORESTART;
1490 	}
1491 
1492 	dmaengine_pause(chan);
1493 
1494 	/*
1495 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1496 	 * data keeps on coming until transaction is complete so check
1497 	 * for DMA_COMPLETE again
1498 	 * Let packet complete handler take care of the packet
1499 	 */
1500 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1501 	if (status == DMA_COMPLETE) {
1502 		spin_unlock_irqrestore(&port->lock, flags);
1503 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1504 		return HRTIMER_NORESTART;
1505 	}
1506 
1507 	/* Handle incomplete DMA receive */
1508 	dmaengine_terminate_async(s->chan_rx);
1509 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1510 
1511 	if (read) {
1512 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1513 		if (count)
1514 			tty_flip_buffer_push(&port->state->port);
1515 	}
1516 
1517 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1518 		sci_dma_rx_submit(s, true);
1519 
1520 	sci_dma_rx_reenable_irq(s);
1521 
1522 	spin_unlock_irqrestore(&port->lock, flags);
1523 
1524 	return HRTIMER_NORESTART;
1525 }
1526 
1527 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1528 					     enum dma_transfer_direction dir)
1529 {
1530 	struct dma_chan *chan;
1531 	struct dma_slave_config cfg;
1532 	int ret;
1533 
1534 	chan = dma_request_slave_channel(port->dev,
1535 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1536 	if (!chan) {
1537 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1538 		return NULL;
1539 	}
1540 
1541 	memset(&cfg, 0, sizeof(cfg));
1542 	cfg.direction = dir;
1543 	if (dir == DMA_MEM_TO_DEV) {
1544 		cfg.dst_addr = port->mapbase +
1545 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1546 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1547 	} else {
1548 		cfg.src_addr = port->mapbase +
1549 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1550 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1551 	}
1552 
1553 	ret = dmaengine_slave_config(chan, &cfg);
1554 	if (ret) {
1555 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1556 		dma_release_channel(chan);
1557 		return NULL;
1558 	}
1559 
1560 	return chan;
1561 }
1562 
1563 static void sci_request_dma(struct uart_port *port)
1564 {
1565 	struct sci_port *s = to_sci_port(port);
1566 	struct dma_chan *chan;
1567 
1568 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1569 
1570 	/*
1571 	 * DMA on console may interfere with Kernel log messages which use
1572 	 * plain putchar(). So, simply don't use it with a console.
1573 	 */
1574 	if (uart_console(port))
1575 		return;
1576 
1577 	if (!port->dev->of_node)
1578 		return;
1579 
1580 	s->cookie_tx = -EINVAL;
1581 
1582 	/*
1583 	 * Don't request a dma channel if no channel was specified
1584 	 * in the device tree.
1585 	 */
1586 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1587 		return;
1588 
1589 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1590 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1591 	if (chan) {
1592 		/* UART circular tx buffer is an aligned page. */
1593 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1594 						port->state->xmit.buf,
1595 						UART_XMIT_SIZE,
1596 						DMA_TO_DEVICE);
1597 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1598 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1599 			dma_release_channel(chan);
1600 		} else {
1601 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1602 				__func__, UART_XMIT_SIZE,
1603 				port->state->xmit.buf, &s->tx_dma_addr);
1604 
1605 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1606 			s->chan_tx_saved = s->chan_tx = chan;
1607 		}
1608 	}
1609 
1610 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1611 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1612 	if (chan) {
1613 		unsigned int i;
1614 		dma_addr_t dma;
1615 		void *buf;
1616 
1617 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1618 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1619 					 &dma, GFP_KERNEL);
1620 		if (!buf) {
1621 			dev_warn(port->dev,
1622 				 "Failed to allocate Rx dma buffer, using PIO\n");
1623 			dma_release_channel(chan);
1624 			return;
1625 		}
1626 
1627 		for (i = 0; i < 2; i++) {
1628 			struct scatterlist *sg = &s->sg_rx[i];
1629 
1630 			sg_init_table(sg, 1);
1631 			s->rx_buf[i] = buf;
1632 			sg_dma_address(sg) = dma;
1633 			sg_dma_len(sg) = s->buf_len_rx;
1634 
1635 			buf += s->buf_len_rx;
1636 			dma += s->buf_len_rx;
1637 		}
1638 
1639 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1640 		s->rx_timer.function = sci_dma_rx_timer_fn;
1641 
1642 		s->chan_rx_saved = s->chan_rx = chan;
1643 
1644 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1645 			sci_dma_rx_submit(s, false);
1646 	}
1647 }
1648 
1649 static void sci_free_dma(struct uart_port *port)
1650 {
1651 	struct sci_port *s = to_sci_port(port);
1652 
1653 	if (s->chan_tx_saved)
1654 		sci_dma_tx_release(s);
1655 	if (s->chan_rx_saved)
1656 		sci_dma_rx_release(s);
1657 }
1658 
1659 static void sci_flush_buffer(struct uart_port *port)
1660 {
1661 	struct sci_port *s = to_sci_port(port);
1662 
1663 	/*
1664 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1665 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1666 	 * pending transfers
1667 	 */
1668 	s->tx_dma_len = 0;
1669 	if (s->chan_tx) {
1670 		dmaengine_terminate_async(s->chan_tx);
1671 		s->cookie_tx = -EINVAL;
1672 	}
1673 }
1674 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1675 static inline void sci_request_dma(struct uart_port *port)
1676 {
1677 }
1678 
1679 static inline void sci_free_dma(struct uart_port *port)
1680 {
1681 }
1682 
1683 #define sci_flush_buffer	NULL
1684 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1685 
1686 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1687 {
1688 	struct uart_port *port = ptr;
1689 	struct sci_port *s = to_sci_port(port);
1690 
1691 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1692 	if (s->chan_rx) {
1693 		u16 scr = serial_port_in(port, SCSCR);
1694 		u16 ssr = serial_port_in(port, SCxSR);
1695 
1696 		/* Disable future Rx interrupts */
1697 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1698 			disable_irq_nosync(irq);
1699 			scr |= SCSCR_RDRQE;
1700 		} else {
1701 			if (sci_dma_rx_submit(s, false) < 0)
1702 				goto handle_pio;
1703 
1704 			scr &= ~SCSCR_RIE;
1705 		}
1706 		serial_port_out(port, SCSCR, scr);
1707 		/* Clear current interrupt */
1708 		serial_port_out(port, SCxSR,
1709 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1710 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1711 			jiffies, s->rx_timeout);
1712 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1713 
1714 		return IRQ_HANDLED;
1715 	}
1716 
1717 handle_pio:
1718 #endif
1719 
1720 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1721 		if (!scif_rtrg_enabled(port))
1722 			scif_set_rtrg(port, s->rx_trigger);
1723 
1724 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1725 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1726 	}
1727 
1728 	/* I think sci_receive_chars has to be called irrespective
1729 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1730 	 * to be disabled?
1731 	 */
1732 	sci_receive_chars(port);
1733 
1734 	return IRQ_HANDLED;
1735 }
1736 
1737 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1738 {
1739 	struct uart_port *port = ptr;
1740 	unsigned long flags;
1741 
1742 	spin_lock_irqsave(&port->lock, flags);
1743 	sci_transmit_chars(port);
1744 	spin_unlock_irqrestore(&port->lock, flags);
1745 
1746 	return IRQ_HANDLED;
1747 }
1748 
1749 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1750 {
1751 	struct uart_port *port = ptr;
1752 
1753 	/* Handle BREAKs */
1754 	sci_handle_breaks(port);
1755 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1756 
1757 	return IRQ_HANDLED;
1758 }
1759 
1760 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1761 {
1762 	struct uart_port *port = ptr;
1763 	struct sci_port *s = to_sci_port(port);
1764 
1765 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1766 		/* Break and Error interrupts are muxed */
1767 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1768 
1769 		/* Break Interrupt */
1770 		if (ssr_status & SCxSR_BRK(port))
1771 			sci_br_interrupt(irq, ptr);
1772 
1773 		/* Break only? */
1774 		if (!(ssr_status & SCxSR_ERRORS(port)))
1775 			return IRQ_HANDLED;
1776 	}
1777 
1778 	/* Handle errors */
1779 	if (port->type == PORT_SCI) {
1780 		if (sci_handle_errors(port)) {
1781 			/* discard character in rx buffer */
1782 			serial_port_in(port, SCxSR);
1783 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1784 		}
1785 	} else {
1786 		sci_handle_fifo_overrun(port);
1787 		if (!s->chan_rx)
1788 			sci_receive_chars(port);
1789 	}
1790 
1791 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1792 
1793 	/* Kick the transmission */
1794 	if (!s->chan_tx)
1795 		sci_tx_interrupt(irq, ptr);
1796 
1797 	return IRQ_HANDLED;
1798 }
1799 
1800 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1801 {
1802 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1803 	struct uart_port *port = ptr;
1804 	struct sci_port *s = to_sci_port(port);
1805 	irqreturn_t ret = IRQ_NONE;
1806 
1807 	ssr_status = serial_port_in(port, SCxSR);
1808 	scr_status = serial_port_in(port, SCSCR);
1809 	if (s->params->overrun_reg == SCxSR)
1810 		orer_status = ssr_status;
1811 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1812 		orer_status = serial_port_in(port, s->params->overrun_reg);
1813 
1814 	err_enabled = scr_status & port_rx_irq_mask(port);
1815 
1816 	/* Tx Interrupt */
1817 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1818 	    !s->chan_tx)
1819 		ret = sci_tx_interrupt(irq, ptr);
1820 
1821 	/*
1822 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1823 	 * DR flags
1824 	 */
1825 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1826 	    (scr_status & SCSCR_RIE))
1827 		ret = sci_rx_interrupt(irq, ptr);
1828 
1829 	/* Error Interrupt */
1830 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1831 		ret = sci_er_interrupt(irq, ptr);
1832 
1833 	/* Break Interrupt */
1834 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1835 		ret = sci_br_interrupt(irq, ptr);
1836 
1837 	/* Overrun Interrupt */
1838 	if (orer_status & s->params->overrun_mask) {
1839 		sci_handle_fifo_overrun(port);
1840 		ret = IRQ_HANDLED;
1841 	}
1842 
1843 	return ret;
1844 }
1845 
1846 static const struct sci_irq_desc {
1847 	const char	*desc;
1848 	irq_handler_t	handler;
1849 } sci_irq_desc[] = {
1850 	/*
1851 	 * Split out handlers, the default case.
1852 	 */
1853 	[SCIx_ERI_IRQ] = {
1854 		.desc = "rx err",
1855 		.handler = sci_er_interrupt,
1856 	},
1857 
1858 	[SCIx_RXI_IRQ] = {
1859 		.desc = "rx full",
1860 		.handler = sci_rx_interrupt,
1861 	},
1862 
1863 	[SCIx_TXI_IRQ] = {
1864 		.desc = "tx empty",
1865 		.handler = sci_tx_interrupt,
1866 	},
1867 
1868 	[SCIx_BRI_IRQ] = {
1869 		.desc = "break",
1870 		.handler = sci_br_interrupt,
1871 	},
1872 
1873 	[SCIx_DRI_IRQ] = {
1874 		.desc = "rx ready",
1875 		.handler = sci_rx_interrupt,
1876 	},
1877 
1878 	[SCIx_TEI_IRQ] = {
1879 		.desc = "tx end",
1880 		.handler = sci_tx_interrupt,
1881 	},
1882 
1883 	/*
1884 	 * Special muxed handler.
1885 	 */
1886 	[SCIx_MUX_IRQ] = {
1887 		.desc = "mux",
1888 		.handler = sci_mpxed_interrupt,
1889 	},
1890 };
1891 
1892 static int sci_request_irq(struct sci_port *port)
1893 {
1894 	struct uart_port *up = &port->port;
1895 	int i, j, w, ret = 0;
1896 
1897 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1898 		const struct sci_irq_desc *desc;
1899 		int irq;
1900 
1901 		/* Check if already registered (muxed) */
1902 		for (w = 0; w < i; w++)
1903 			if (port->irqs[w] == port->irqs[i])
1904 				w = i + 1;
1905 		if (w > i)
1906 			continue;
1907 
1908 		if (SCIx_IRQ_IS_MUXED(port)) {
1909 			i = SCIx_MUX_IRQ;
1910 			irq = up->irq;
1911 		} else {
1912 			irq = port->irqs[i];
1913 
1914 			/*
1915 			 * Certain port types won't support all of the
1916 			 * available interrupt sources.
1917 			 */
1918 			if (unlikely(irq < 0))
1919 				continue;
1920 		}
1921 
1922 		desc = sci_irq_desc + i;
1923 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1924 					    dev_name(up->dev), desc->desc);
1925 		if (!port->irqstr[j]) {
1926 			ret = -ENOMEM;
1927 			goto out_nomem;
1928 		}
1929 
1930 		ret = request_irq(irq, desc->handler, up->irqflags,
1931 				  port->irqstr[j], port);
1932 		if (unlikely(ret)) {
1933 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1934 			goto out_noirq;
1935 		}
1936 	}
1937 
1938 	return 0;
1939 
1940 out_noirq:
1941 	while (--i >= 0)
1942 		free_irq(port->irqs[i], port);
1943 
1944 out_nomem:
1945 	while (--j >= 0)
1946 		kfree(port->irqstr[j]);
1947 
1948 	return ret;
1949 }
1950 
1951 static void sci_free_irq(struct sci_port *port)
1952 {
1953 	int i, j;
1954 
1955 	/*
1956 	 * Intentionally in reverse order so we iterate over the muxed
1957 	 * IRQ first.
1958 	 */
1959 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1960 		int irq = port->irqs[i];
1961 
1962 		/*
1963 		 * Certain port types won't support all of the available
1964 		 * interrupt sources.
1965 		 */
1966 		if (unlikely(irq < 0))
1967 			continue;
1968 
1969 		/* Check if already freed (irq was muxed) */
1970 		for (j = 0; j < i; j++)
1971 			if (port->irqs[j] == irq)
1972 				j = i + 1;
1973 		if (j > i)
1974 			continue;
1975 
1976 		free_irq(port->irqs[i], port);
1977 		kfree(port->irqstr[i]);
1978 
1979 		if (SCIx_IRQ_IS_MUXED(port)) {
1980 			/* If there's only one IRQ, we're done. */
1981 			return;
1982 		}
1983 	}
1984 }
1985 
1986 static unsigned int sci_tx_empty(struct uart_port *port)
1987 {
1988 	unsigned short status = serial_port_in(port, SCxSR);
1989 	unsigned short in_tx_fifo = sci_txfill(port);
1990 
1991 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1992 }
1993 
1994 static void sci_set_rts(struct uart_port *port, bool state)
1995 {
1996 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1997 		u16 data = serial_port_in(port, SCPDR);
1998 
1999 		/* Active low */
2000 		if (state)
2001 			data &= ~SCPDR_RTSD;
2002 		else
2003 			data |= SCPDR_RTSD;
2004 		serial_port_out(port, SCPDR, data);
2005 
2006 		/* RTS# is output */
2007 		serial_port_out(port, SCPCR,
2008 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2009 	} else if (sci_getreg(port, SCSPTR)->size) {
2010 		u16 ctrl = serial_port_in(port, SCSPTR);
2011 
2012 		/* Active low */
2013 		if (state)
2014 			ctrl &= ~SCSPTR_RTSDT;
2015 		else
2016 			ctrl |= SCSPTR_RTSDT;
2017 		serial_port_out(port, SCSPTR, ctrl);
2018 	}
2019 }
2020 
2021 static bool sci_get_cts(struct uart_port *port)
2022 {
2023 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2024 		/* Active low */
2025 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2026 	} else if (sci_getreg(port, SCSPTR)->size) {
2027 		/* Active low */
2028 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2029 	}
2030 
2031 	return true;
2032 }
2033 
2034 /*
2035  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2036  * CTS/RTS is supported in hardware by at least one port and controlled
2037  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2038  * handled via the ->init_pins() op, which is a bit of a one-way street,
2039  * lacking any ability to defer pin control -- this will later be
2040  * converted over to the GPIO framework).
2041  *
2042  * Other modes (such as loopback) are supported generically on certain
2043  * port types, but not others. For these it's sufficient to test for the
2044  * existence of the support register and simply ignore the port type.
2045  */
2046 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2047 {
2048 	struct sci_port *s = to_sci_port(port);
2049 
2050 	if (mctrl & TIOCM_LOOP) {
2051 		const struct plat_sci_reg *reg;
2052 
2053 		/*
2054 		 * Standard loopback mode for SCFCR ports.
2055 		 */
2056 		reg = sci_getreg(port, SCFCR);
2057 		if (reg->size)
2058 			serial_port_out(port, SCFCR,
2059 					serial_port_in(port, SCFCR) |
2060 					SCFCR_LOOP);
2061 	}
2062 
2063 	mctrl_gpio_set(s->gpios, mctrl);
2064 
2065 	if (!s->has_rtscts)
2066 		return;
2067 
2068 	if (!(mctrl & TIOCM_RTS)) {
2069 		/* Disable Auto RTS */
2070 		serial_port_out(port, SCFCR,
2071 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2072 
2073 		/* Clear RTS */
2074 		sci_set_rts(port, 0);
2075 	} else if (s->autorts) {
2076 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2077 			/* Enable RTS# pin function */
2078 			serial_port_out(port, SCPCR,
2079 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2080 		}
2081 
2082 		/* Enable Auto RTS */
2083 		serial_port_out(port, SCFCR,
2084 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2085 	} else {
2086 		/* Set RTS */
2087 		sci_set_rts(port, 1);
2088 	}
2089 }
2090 
2091 static unsigned int sci_get_mctrl(struct uart_port *port)
2092 {
2093 	struct sci_port *s = to_sci_port(port);
2094 	struct mctrl_gpios *gpios = s->gpios;
2095 	unsigned int mctrl = 0;
2096 
2097 	mctrl_gpio_get(gpios, &mctrl);
2098 
2099 	/*
2100 	 * CTS/RTS is handled in hardware when supported, while nothing
2101 	 * else is wired up.
2102 	 */
2103 	if (s->autorts) {
2104 		if (sci_get_cts(port))
2105 			mctrl |= TIOCM_CTS;
2106 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2107 		mctrl |= TIOCM_CTS;
2108 	}
2109 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2110 		mctrl |= TIOCM_DSR;
2111 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2112 		mctrl |= TIOCM_CAR;
2113 
2114 	return mctrl;
2115 }
2116 
2117 static void sci_enable_ms(struct uart_port *port)
2118 {
2119 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2120 }
2121 
2122 static void sci_break_ctl(struct uart_port *port, int break_state)
2123 {
2124 	unsigned short scscr, scsptr;
2125 	unsigned long flags;
2126 
2127 	/* check wheter the port has SCSPTR */
2128 	if (!sci_getreg(port, SCSPTR)->size) {
2129 		/*
2130 		 * Not supported by hardware. Most parts couple break and rx
2131 		 * interrupts together, with break detection always enabled.
2132 		 */
2133 		return;
2134 	}
2135 
2136 	spin_lock_irqsave(&port->lock, flags);
2137 	scsptr = serial_port_in(port, SCSPTR);
2138 	scscr = serial_port_in(port, SCSCR);
2139 
2140 	if (break_state == -1) {
2141 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2142 		scscr &= ~SCSCR_TE;
2143 	} else {
2144 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2145 		scscr |= SCSCR_TE;
2146 	}
2147 
2148 	serial_port_out(port, SCSPTR, scsptr);
2149 	serial_port_out(port, SCSCR, scscr);
2150 	spin_unlock_irqrestore(&port->lock, flags);
2151 }
2152 
2153 static int sci_startup(struct uart_port *port)
2154 {
2155 	struct sci_port *s = to_sci_port(port);
2156 	int ret;
2157 
2158 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2159 
2160 	sci_request_dma(port);
2161 
2162 	ret = sci_request_irq(s);
2163 	if (unlikely(ret < 0)) {
2164 		sci_free_dma(port);
2165 		return ret;
2166 	}
2167 
2168 	return 0;
2169 }
2170 
2171 static void sci_shutdown(struct uart_port *port)
2172 {
2173 	struct sci_port *s = to_sci_port(port);
2174 	unsigned long flags;
2175 	u16 scr;
2176 
2177 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2178 
2179 	s->autorts = false;
2180 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2181 
2182 	spin_lock_irqsave(&port->lock, flags);
2183 	sci_stop_rx(port);
2184 	sci_stop_tx(port);
2185 	/*
2186 	 * Stop RX and TX, disable related interrupts, keep clock source
2187 	 * and HSCIF TOT bits
2188 	 */
2189 	scr = serial_port_in(port, SCSCR);
2190 	serial_port_out(port, SCSCR, scr &
2191 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2192 	spin_unlock_irqrestore(&port->lock, flags);
2193 
2194 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2195 	if (s->chan_rx_saved) {
2196 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2197 			port->line);
2198 		hrtimer_cancel(&s->rx_timer);
2199 	}
2200 #endif
2201 
2202 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2203 		del_timer_sync(&s->rx_fifo_timer);
2204 	sci_free_irq(s);
2205 	sci_free_dma(port);
2206 }
2207 
2208 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2209 			unsigned int *srr)
2210 {
2211 	unsigned long freq = s->clk_rates[SCI_SCK];
2212 	int err, min_err = INT_MAX;
2213 	unsigned int sr;
2214 
2215 	if (s->port.type != PORT_HSCIF)
2216 		freq *= 2;
2217 
2218 	for_each_sr(sr, s) {
2219 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2220 		if (abs(err) >= abs(min_err))
2221 			continue;
2222 
2223 		min_err = err;
2224 		*srr = sr - 1;
2225 
2226 		if (!err)
2227 			break;
2228 	}
2229 
2230 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2231 		*srr + 1);
2232 	return min_err;
2233 }
2234 
2235 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2236 			unsigned long freq, unsigned int *dlr,
2237 			unsigned int *srr)
2238 {
2239 	int err, min_err = INT_MAX;
2240 	unsigned int sr, dl;
2241 
2242 	if (s->port.type != PORT_HSCIF)
2243 		freq *= 2;
2244 
2245 	for_each_sr(sr, s) {
2246 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2247 		dl = clamp(dl, 1U, 65535U);
2248 
2249 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2250 		if (abs(err) >= abs(min_err))
2251 			continue;
2252 
2253 		min_err = err;
2254 		*dlr = dl;
2255 		*srr = sr - 1;
2256 
2257 		if (!err)
2258 			break;
2259 	}
2260 
2261 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2262 		min_err, *dlr, *srr + 1);
2263 	return min_err;
2264 }
2265 
2266 /* calculate sample rate, BRR, and clock select */
2267 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2268 			  unsigned int *brr, unsigned int *srr,
2269 			  unsigned int *cks)
2270 {
2271 	unsigned long freq = s->clk_rates[SCI_FCK];
2272 	unsigned int sr, br, prediv, scrate, c;
2273 	int err, min_err = INT_MAX;
2274 
2275 	if (s->port.type != PORT_HSCIF)
2276 		freq *= 2;
2277 
2278 	/*
2279 	 * Find the combination of sample rate and clock select with the
2280 	 * smallest deviation from the desired baud rate.
2281 	 * Prefer high sample rates to maximise the receive margin.
2282 	 *
2283 	 * M: Receive margin (%)
2284 	 * N: Ratio of bit rate to clock (N = sampling rate)
2285 	 * D: Clock duty (D = 0 to 1.0)
2286 	 * L: Frame length (L = 9 to 12)
2287 	 * F: Absolute value of clock frequency deviation
2288 	 *
2289 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2290 	 *      (|D - 0.5| / N * (1 + F))|
2291 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2292 	 */
2293 	for_each_sr(sr, s) {
2294 		for (c = 0; c <= 3; c++) {
2295 			/* integerized formulas from HSCIF documentation */
2296 			prediv = sr * (1 << (2 * c + 1));
2297 
2298 			/*
2299 			 * We need to calculate:
2300 			 *
2301 			 *     br = freq / (prediv * bps) clamped to [1..256]
2302 			 *     err = freq / (br * prediv) - bps
2303 			 *
2304 			 * Watch out for overflow when calculating the desired
2305 			 * sampling clock rate!
2306 			 */
2307 			if (bps > UINT_MAX / prediv)
2308 				break;
2309 
2310 			scrate = prediv * bps;
2311 			br = DIV_ROUND_CLOSEST(freq, scrate);
2312 			br = clamp(br, 1U, 256U);
2313 
2314 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2315 			if (abs(err) >= abs(min_err))
2316 				continue;
2317 
2318 			min_err = err;
2319 			*brr = br - 1;
2320 			*srr = sr - 1;
2321 			*cks = c;
2322 
2323 			if (!err)
2324 				goto found;
2325 		}
2326 	}
2327 
2328 found:
2329 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2330 		min_err, *brr, *srr + 1, *cks);
2331 	return min_err;
2332 }
2333 
2334 static void sci_reset(struct uart_port *port)
2335 {
2336 	const struct plat_sci_reg *reg;
2337 	unsigned int status;
2338 	struct sci_port *s = to_sci_port(port);
2339 
2340 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2341 
2342 	reg = sci_getreg(port, SCFCR);
2343 	if (reg->size)
2344 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2345 
2346 	sci_clear_SCxSR(port,
2347 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2348 			SCxSR_BREAK_CLEAR(port));
2349 	if (sci_getreg(port, SCLSR)->size) {
2350 		status = serial_port_in(port, SCLSR);
2351 		status &= ~(SCLSR_TO | SCLSR_ORER);
2352 		serial_port_out(port, SCLSR, status);
2353 	}
2354 
2355 	if (s->rx_trigger > 1) {
2356 		if (s->rx_fifo_timeout) {
2357 			scif_set_rtrg(port, 1);
2358 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2359 		} else {
2360 			if (port->type == PORT_SCIFA ||
2361 			    port->type == PORT_SCIFB)
2362 				scif_set_rtrg(port, 1);
2363 			else
2364 				scif_set_rtrg(port, s->rx_trigger);
2365 		}
2366 	}
2367 }
2368 
2369 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2370 			    struct ktermios *old)
2371 {
2372 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2373 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2374 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2375 	struct sci_port *s = to_sci_port(port);
2376 	const struct plat_sci_reg *reg;
2377 	int min_err = INT_MAX, err;
2378 	unsigned long max_freq = 0;
2379 	int best_clk = -1;
2380 	unsigned long flags;
2381 
2382 	if ((termios->c_cflag & CSIZE) == CS7)
2383 		smr_val |= SCSMR_CHR;
2384 	if (termios->c_cflag & PARENB)
2385 		smr_val |= SCSMR_PE;
2386 	if (termios->c_cflag & PARODD)
2387 		smr_val |= SCSMR_PE | SCSMR_ODD;
2388 	if (termios->c_cflag & CSTOPB)
2389 		smr_val |= SCSMR_STOP;
2390 
2391 	/*
2392 	 * earlyprintk comes here early on with port->uartclk set to zero.
2393 	 * the clock framework is not up and running at this point so here
2394 	 * we assume that 115200 is the maximum baud rate. please note that
2395 	 * the baud rate is not programmed during earlyprintk - it is assumed
2396 	 * that the previous boot loader has enabled required clocks and
2397 	 * setup the baud rate generator hardware for us already.
2398 	 */
2399 	if (!port->uartclk) {
2400 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2401 		goto done;
2402 	}
2403 
2404 	for (i = 0; i < SCI_NUM_CLKS; i++)
2405 		max_freq = max(max_freq, s->clk_rates[i]);
2406 
2407 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2408 	if (!baud)
2409 		goto done;
2410 
2411 	/*
2412 	 * There can be multiple sources for the sampling clock.  Find the one
2413 	 * that gives us the smallest deviation from the desired baud rate.
2414 	 */
2415 
2416 	/* Optional Undivided External Clock */
2417 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2418 	    port->type != PORT_SCIFB) {
2419 		err = sci_sck_calc(s, baud, &srr1);
2420 		if (abs(err) < abs(min_err)) {
2421 			best_clk = SCI_SCK;
2422 			scr_val = SCSCR_CKE1;
2423 			sccks = SCCKS_CKS;
2424 			min_err = err;
2425 			srr = srr1;
2426 			if (!err)
2427 				goto done;
2428 		}
2429 	}
2430 
2431 	/* Optional BRG Frequency Divided External Clock */
2432 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2433 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2434 				   &srr1);
2435 		if (abs(err) < abs(min_err)) {
2436 			best_clk = SCI_SCIF_CLK;
2437 			scr_val = SCSCR_CKE1;
2438 			sccks = 0;
2439 			min_err = err;
2440 			dl = dl1;
2441 			srr = srr1;
2442 			if (!err)
2443 				goto done;
2444 		}
2445 	}
2446 
2447 	/* Optional BRG Frequency Divided Internal Clock */
2448 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2449 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2450 				   &srr1);
2451 		if (abs(err) < abs(min_err)) {
2452 			best_clk = SCI_BRG_INT;
2453 			scr_val = SCSCR_CKE1;
2454 			sccks = SCCKS_XIN;
2455 			min_err = err;
2456 			dl = dl1;
2457 			srr = srr1;
2458 			if (!min_err)
2459 				goto done;
2460 		}
2461 	}
2462 
2463 	/* Divided Functional Clock using standard Bit Rate Register */
2464 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2465 	if (abs(err) < abs(min_err)) {
2466 		best_clk = SCI_FCK;
2467 		scr_val = 0;
2468 		min_err = err;
2469 		brr = brr1;
2470 		srr = srr1;
2471 		cks = cks1;
2472 	}
2473 
2474 done:
2475 	if (best_clk >= 0)
2476 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2477 			s->clks[best_clk], baud, min_err);
2478 
2479 	sci_port_enable(s);
2480 
2481 	/*
2482 	 * Program the optional External Baud Rate Generator (BRG) first.
2483 	 * It controls the mux to select (H)SCK or frequency divided clock.
2484 	 */
2485 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2486 		serial_port_out(port, SCDL, dl);
2487 		serial_port_out(port, SCCKS, sccks);
2488 	}
2489 
2490 	spin_lock_irqsave(&port->lock, flags);
2491 
2492 	sci_reset(port);
2493 
2494 	uart_update_timeout(port, termios->c_cflag, baud);
2495 
2496 	/* byte size and parity */
2497 	switch (termios->c_cflag & CSIZE) {
2498 	case CS5:
2499 		bits = 7;
2500 		break;
2501 	case CS6:
2502 		bits = 8;
2503 		break;
2504 	case CS7:
2505 		bits = 9;
2506 		break;
2507 	default:
2508 		bits = 10;
2509 		break;
2510 	}
2511 
2512 	if (termios->c_cflag & CSTOPB)
2513 		bits++;
2514 	if (termios->c_cflag & PARENB)
2515 		bits++;
2516 
2517 	if (best_clk >= 0) {
2518 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2519 			switch (srr + 1) {
2520 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2521 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2522 			case 11: smr_val |= SCSMR_SRC_11; break;
2523 			case 13: smr_val |= SCSMR_SRC_13; break;
2524 			case 16: smr_val |= SCSMR_SRC_16; break;
2525 			case 17: smr_val |= SCSMR_SRC_17; break;
2526 			case 19: smr_val |= SCSMR_SRC_19; break;
2527 			case 27: smr_val |= SCSMR_SRC_27; break;
2528 			}
2529 		smr_val |= cks;
2530 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2531 		serial_port_out(port, SCSMR, smr_val);
2532 		serial_port_out(port, SCBRR, brr);
2533 		if (sci_getreg(port, HSSRR)->size) {
2534 			unsigned int hssrr = srr | HSCIF_SRE;
2535 			/* Calculate deviation from intended rate at the
2536 			 * center of the last stop bit in sampling clocks.
2537 			 */
2538 			int last_stop = bits * 2 - 1;
2539 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2540 							  (int)(srr + 1),
2541 							  2 * (int)baud);
2542 
2543 			if (abs(deviation) >= 2) {
2544 				/* At least two sampling clocks off at the
2545 				 * last stop bit; we can increase the error
2546 				 * margin by shifting the sampling point.
2547 				 */
2548 				int shift = clamp(deviation / 2, -8, 7);
2549 
2550 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2551 					 HSCIF_SRHP_MASK;
2552 				hssrr |= HSCIF_SRDE;
2553 			}
2554 			serial_port_out(port, HSSRR, hssrr);
2555 		}
2556 
2557 		/* Wait one bit interval */
2558 		udelay((1000000 + (baud - 1)) / baud);
2559 	} else {
2560 		/* Don't touch the bit rate configuration */
2561 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2562 		smr_val |= serial_port_in(port, SCSMR) &
2563 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2564 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2565 		serial_port_out(port, SCSMR, smr_val);
2566 	}
2567 
2568 	sci_init_pins(port, termios->c_cflag);
2569 
2570 	port->status &= ~UPSTAT_AUTOCTS;
2571 	s->autorts = false;
2572 	reg = sci_getreg(port, SCFCR);
2573 	if (reg->size) {
2574 		unsigned short ctrl = serial_port_in(port, SCFCR);
2575 
2576 		if ((port->flags & UPF_HARD_FLOW) &&
2577 		    (termios->c_cflag & CRTSCTS)) {
2578 			/* There is no CTS interrupt to restart the hardware */
2579 			port->status |= UPSTAT_AUTOCTS;
2580 			/* MCE is enabled when RTS is raised */
2581 			s->autorts = true;
2582 		}
2583 
2584 		/*
2585 		 * As we've done a sci_reset() above, ensure we don't
2586 		 * interfere with the FIFOs while toggling MCE. As the
2587 		 * reset values could still be set, simply mask them out.
2588 		 */
2589 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2590 
2591 		serial_port_out(port, SCFCR, ctrl);
2592 	}
2593 	if (port->flags & UPF_HARD_FLOW) {
2594 		/* Refresh (Auto) RTS */
2595 		sci_set_mctrl(port, port->mctrl);
2596 	}
2597 
2598 	scr_val |= SCSCR_RE | SCSCR_TE |
2599 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2600 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2601 	if ((srr + 1 == 5) &&
2602 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2603 		/*
2604 		 * In asynchronous mode, when the sampling rate is 1/5, first
2605 		 * received data may become invalid on some SCIFA and SCIFB.
2606 		 * To avoid this problem wait more than 1 serial data time (1
2607 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2608 		 */
2609 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2610 	}
2611 
2612 	/*
2613 	 * Calculate delay for 2 DMA buffers (4 FIFO).
2614 	 * See serial_core.c::uart_update_timeout().
2615 	 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2616 	 * function calculates 1 jiffie for the data plus 5 jiffies for the
2617 	 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2618 	 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2619 	 * value obtained by this formula is too small. Therefore, if the value
2620 	 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2621 	 */
2622 	s->rx_frame = (10000 * bits) / (baud / 100);
2623 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2624 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2625 	if (s->rx_timeout < 20)
2626 		s->rx_timeout = 20;
2627 #endif
2628 
2629 	if ((termios->c_cflag & CREAD) != 0)
2630 		sci_start_rx(port);
2631 
2632 	spin_unlock_irqrestore(&port->lock, flags);
2633 
2634 	sci_port_disable(s);
2635 
2636 	if (UART_ENABLE_MS(port, termios->c_cflag))
2637 		sci_enable_ms(port);
2638 }
2639 
2640 static void sci_pm(struct uart_port *port, unsigned int state,
2641 		   unsigned int oldstate)
2642 {
2643 	struct sci_port *sci_port = to_sci_port(port);
2644 
2645 	switch (state) {
2646 	case UART_PM_STATE_OFF:
2647 		sci_port_disable(sci_port);
2648 		break;
2649 	default:
2650 		sci_port_enable(sci_port);
2651 		break;
2652 	}
2653 }
2654 
2655 static const char *sci_type(struct uart_port *port)
2656 {
2657 	switch (port->type) {
2658 	case PORT_IRDA:
2659 		return "irda";
2660 	case PORT_SCI:
2661 		return "sci";
2662 	case PORT_SCIF:
2663 		return "scif";
2664 	case PORT_SCIFA:
2665 		return "scifa";
2666 	case PORT_SCIFB:
2667 		return "scifb";
2668 	case PORT_HSCIF:
2669 		return "hscif";
2670 	}
2671 
2672 	return NULL;
2673 }
2674 
2675 static int sci_remap_port(struct uart_port *port)
2676 {
2677 	struct sci_port *sport = to_sci_port(port);
2678 
2679 	/*
2680 	 * Nothing to do if there's already an established membase.
2681 	 */
2682 	if (port->membase)
2683 		return 0;
2684 
2685 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2686 		port->membase = ioremap(port->mapbase, sport->reg_size);
2687 		if (unlikely(!port->membase)) {
2688 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2689 			return -ENXIO;
2690 		}
2691 	} else {
2692 		/*
2693 		 * For the simple (and majority of) cases where we don't
2694 		 * need to do any remapping, just cast the cookie
2695 		 * directly.
2696 		 */
2697 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2698 	}
2699 
2700 	return 0;
2701 }
2702 
2703 static void sci_release_port(struct uart_port *port)
2704 {
2705 	struct sci_port *sport = to_sci_port(port);
2706 
2707 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2708 		iounmap(port->membase);
2709 		port->membase = NULL;
2710 	}
2711 
2712 	release_mem_region(port->mapbase, sport->reg_size);
2713 }
2714 
2715 static int sci_request_port(struct uart_port *port)
2716 {
2717 	struct resource *res;
2718 	struct sci_port *sport = to_sci_port(port);
2719 	int ret;
2720 
2721 	res = request_mem_region(port->mapbase, sport->reg_size,
2722 				 dev_name(port->dev));
2723 	if (unlikely(res == NULL)) {
2724 		dev_err(port->dev, "request_mem_region failed.");
2725 		return -EBUSY;
2726 	}
2727 
2728 	ret = sci_remap_port(port);
2729 	if (unlikely(ret != 0)) {
2730 		release_resource(res);
2731 		return ret;
2732 	}
2733 
2734 	return 0;
2735 }
2736 
2737 static void sci_config_port(struct uart_port *port, int flags)
2738 {
2739 	if (flags & UART_CONFIG_TYPE) {
2740 		struct sci_port *sport = to_sci_port(port);
2741 
2742 		port->type = sport->cfg->type;
2743 		sci_request_port(port);
2744 	}
2745 }
2746 
2747 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2748 {
2749 	if (ser->baud_base < 2400)
2750 		/* No paper tape reader for Mitch.. */
2751 		return -EINVAL;
2752 
2753 	return 0;
2754 }
2755 
2756 static const struct uart_ops sci_uart_ops = {
2757 	.tx_empty	= sci_tx_empty,
2758 	.set_mctrl	= sci_set_mctrl,
2759 	.get_mctrl	= sci_get_mctrl,
2760 	.start_tx	= sci_start_tx,
2761 	.stop_tx	= sci_stop_tx,
2762 	.stop_rx	= sci_stop_rx,
2763 	.enable_ms	= sci_enable_ms,
2764 	.break_ctl	= sci_break_ctl,
2765 	.startup	= sci_startup,
2766 	.shutdown	= sci_shutdown,
2767 	.flush_buffer	= sci_flush_buffer,
2768 	.set_termios	= sci_set_termios,
2769 	.pm		= sci_pm,
2770 	.type		= sci_type,
2771 	.release_port	= sci_release_port,
2772 	.request_port	= sci_request_port,
2773 	.config_port	= sci_config_port,
2774 	.verify_port	= sci_verify_port,
2775 #ifdef CONFIG_CONSOLE_POLL
2776 	.poll_get_char	= sci_poll_get_char,
2777 	.poll_put_char	= sci_poll_put_char,
2778 #endif
2779 };
2780 
2781 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2782 {
2783 	const char *clk_names[] = {
2784 		[SCI_FCK] = "fck",
2785 		[SCI_SCK] = "sck",
2786 		[SCI_BRG_INT] = "brg_int",
2787 		[SCI_SCIF_CLK] = "scif_clk",
2788 	};
2789 	struct clk *clk;
2790 	unsigned int i;
2791 
2792 	if (sci_port->cfg->type == PORT_HSCIF)
2793 		clk_names[SCI_SCK] = "hsck";
2794 
2795 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2796 		clk = devm_clk_get(dev, clk_names[i]);
2797 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2798 			return -EPROBE_DEFER;
2799 
2800 		if (IS_ERR(clk) && i == SCI_FCK) {
2801 			/*
2802 			 * "fck" used to be called "sci_ick", and we need to
2803 			 * maintain DT backward compatibility.
2804 			 */
2805 			clk = devm_clk_get(dev, "sci_ick");
2806 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2807 				return -EPROBE_DEFER;
2808 
2809 			if (!IS_ERR(clk))
2810 				goto found;
2811 
2812 			/*
2813 			 * Not all SH platforms declare a clock lookup entry
2814 			 * for SCI devices, in which case we need to get the
2815 			 * global "peripheral_clk" clock.
2816 			 */
2817 			clk = devm_clk_get(dev, "peripheral_clk");
2818 			if (!IS_ERR(clk))
2819 				goto found;
2820 
2821 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2822 				PTR_ERR(clk));
2823 			return PTR_ERR(clk);
2824 		}
2825 
2826 found:
2827 		if (IS_ERR(clk))
2828 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2829 				PTR_ERR(clk));
2830 		else
2831 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2832 				clk, clk_get_rate(clk));
2833 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2834 	}
2835 	return 0;
2836 }
2837 
2838 static const struct sci_port_params *
2839 sci_probe_regmap(const struct plat_sci_port *cfg)
2840 {
2841 	unsigned int regtype;
2842 
2843 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2844 		return &sci_port_params[cfg->regtype];
2845 
2846 	switch (cfg->type) {
2847 	case PORT_SCI:
2848 		regtype = SCIx_SCI_REGTYPE;
2849 		break;
2850 	case PORT_IRDA:
2851 		regtype = SCIx_IRDA_REGTYPE;
2852 		break;
2853 	case PORT_SCIFA:
2854 		regtype = SCIx_SCIFA_REGTYPE;
2855 		break;
2856 	case PORT_SCIFB:
2857 		regtype = SCIx_SCIFB_REGTYPE;
2858 		break;
2859 	case PORT_SCIF:
2860 		/*
2861 		 * The SH-4 is a bit of a misnomer here, although that's
2862 		 * where this particular port layout originated. This
2863 		 * configuration (or some slight variation thereof)
2864 		 * remains the dominant model for all SCIFs.
2865 		 */
2866 		regtype = SCIx_SH4_SCIF_REGTYPE;
2867 		break;
2868 	case PORT_HSCIF:
2869 		regtype = SCIx_HSCIF_REGTYPE;
2870 		break;
2871 	default:
2872 		pr_err("Can't probe register map for given port\n");
2873 		return NULL;
2874 	}
2875 
2876 	return &sci_port_params[regtype];
2877 }
2878 
2879 static int sci_init_single(struct platform_device *dev,
2880 			   struct sci_port *sci_port, unsigned int index,
2881 			   const struct plat_sci_port *p, bool early)
2882 {
2883 	struct uart_port *port = &sci_port->port;
2884 	const struct resource *res;
2885 	unsigned int i;
2886 	int ret;
2887 
2888 	sci_port->cfg	= p;
2889 
2890 	port->ops	= &sci_uart_ops;
2891 	port->iotype	= UPIO_MEM;
2892 	port->line	= index;
2893 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2894 
2895 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2896 	if (res == NULL)
2897 		return -ENOMEM;
2898 
2899 	port->mapbase = res->start;
2900 	sci_port->reg_size = resource_size(res);
2901 
2902 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2903 		if (i)
2904 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2905 		else
2906 			sci_port->irqs[i] = platform_get_irq(dev, i);
2907 	}
2908 
2909 	/* The SCI generates several interrupts. They can be muxed together or
2910 	 * connected to different interrupt lines. In the muxed case only one
2911 	 * interrupt resource is specified as there is only one interrupt ID.
2912 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2913 	 * from the SCI, however those signals might have their own individual
2914 	 * interrupt ID numbers, or muxed together with another interrupt.
2915 	 */
2916 	if (sci_port->irqs[0] < 0)
2917 		return -ENXIO;
2918 
2919 	if (sci_port->irqs[1] < 0)
2920 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2921 			sci_port->irqs[i] = sci_port->irqs[0];
2922 
2923 	sci_port->params = sci_probe_regmap(p);
2924 	if (unlikely(sci_port->params == NULL))
2925 		return -EINVAL;
2926 
2927 	switch (p->type) {
2928 	case PORT_SCIFB:
2929 		sci_port->rx_trigger = 48;
2930 		break;
2931 	case PORT_HSCIF:
2932 		sci_port->rx_trigger = 64;
2933 		break;
2934 	case PORT_SCIFA:
2935 		sci_port->rx_trigger = 32;
2936 		break;
2937 	case PORT_SCIF:
2938 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2939 			/* RX triggering not implemented for this IP */
2940 			sci_port->rx_trigger = 1;
2941 		else
2942 			sci_port->rx_trigger = 8;
2943 		break;
2944 	default:
2945 		sci_port->rx_trigger = 1;
2946 		break;
2947 	}
2948 
2949 	sci_port->rx_fifo_timeout = 0;
2950 	sci_port->hscif_tot = 0;
2951 
2952 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2953 	 * match the SoC datasheet, this should be investigated. Let platform
2954 	 * data override the sampling rate for now.
2955 	 */
2956 	sci_port->sampling_rate_mask = p->sampling_rate
2957 				     ? SCI_SR(p->sampling_rate)
2958 				     : sci_port->params->sampling_rate_mask;
2959 
2960 	if (!early) {
2961 		ret = sci_init_clocks(sci_port, &dev->dev);
2962 		if (ret < 0)
2963 			return ret;
2964 
2965 		port->dev = &dev->dev;
2966 
2967 		pm_runtime_enable(&dev->dev);
2968 	}
2969 
2970 	port->type		= p->type;
2971 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2972 	port->fifosize		= sci_port->params->fifosize;
2973 
2974 	if (port->type == PORT_SCI) {
2975 		if (sci_port->reg_size >= 0x20)
2976 			port->regshift = 2;
2977 		else
2978 			port->regshift = 1;
2979 	}
2980 
2981 	/*
2982 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2983 	 * for the multi-IRQ ports, which is where we are primarily
2984 	 * concerned with the shutdown path synchronization.
2985 	 *
2986 	 * For the muxed case there's nothing more to do.
2987 	 */
2988 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2989 	port->irqflags		= 0;
2990 
2991 	port->serial_in		= sci_serial_in;
2992 	port->serial_out	= sci_serial_out;
2993 
2994 	return 0;
2995 }
2996 
2997 static void sci_cleanup_single(struct sci_port *port)
2998 {
2999 	pm_runtime_disable(port->port.dev);
3000 }
3001 
3002 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3003     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3004 static void serial_console_putchar(struct uart_port *port, int ch)
3005 {
3006 	sci_poll_put_char(port, ch);
3007 }
3008 
3009 /*
3010  *	Print a string to the serial port trying not to disturb
3011  *	any possible real use of the port...
3012  */
3013 static void serial_console_write(struct console *co, const char *s,
3014 				 unsigned count)
3015 {
3016 	struct sci_port *sci_port = &sci_ports[co->index];
3017 	struct uart_port *port = &sci_port->port;
3018 	unsigned short bits, ctrl, ctrl_temp;
3019 	unsigned long flags;
3020 	int locked = 1;
3021 
3022 	if (port->sysrq)
3023 		locked = 0;
3024 	else if (oops_in_progress)
3025 		locked = spin_trylock_irqsave(&port->lock, flags);
3026 	else
3027 		spin_lock_irqsave(&port->lock, flags);
3028 
3029 	/* first save SCSCR then disable interrupts, keep clock source */
3030 	ctrl = serial_port_in(port, SCSCR);
3031 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3032 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3033 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3034 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3035 
3036 	uart_console_write(port, s, count, serial_console_putchar);
3037 
3038 	/* wait until fifo is empty and last bit has been transmitted */
3039 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3040 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3041 		cpu_relax();
3042 
3043 	/* restore the SCSCR */
3044 	serial_port_out(port, SCSCR, ctrl);
3045 
3046 	if (locked)
3047 		spin_unlock_irqrestore(&port->lock, flags);
3048 }
3049 
3050 static int serial_console_setup(struct console *co, char *options)
3051 {
3052 	struct sci_port *sci_port;
3053 	struct uart_port *port;
3054 	int baud = 115200;
3055 	int bits = 8;
3056 	int parity = 'n';
3057 	int flow = 'n';
3058 	int ret;
3059 
3060 	/*
3061 	 * Refuse to handle any bogus ports.
3062 	 */
3063 	if (co->index < 0 || co->index >= SCI_NPORTS)
3064 		return -ENODEV;
3065 
3066 	sci_port = &sci_ports[co->index];
3067 	port = &sci_port->port;
3068 
3069 	/*
3070 	 * Refuse to handle uninitialized ports.
3071 	 */
3072 	if (!port->ops)
3073 		return -ENODEV;
3074 
3075 	ret = sci_remap_port(port);
3076 	if (unlikely(ret != 0))
3077 		return ret;
3078 
3079 	if (options)
3080 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3081 
3082 	return uart_set_options(port, co, baud, parity, bits, flow);
3083 }
3084 
3085 static struct console serial_console = {
3086 	.name		= "ttySC",
3087 	.device		= uart_console_device,
3088 	.write		= serial_console_write,
3089 	.setup		= serial_console_setup,
3090 	.flags		= CON_PRINTBUFFER,
3091 	.index		= -1,
3092 	.data		= &sci_uart_driver,
3093 };
3094 
3095 #ifdef CONFIG_SUPERH
3096 static struct console early_serial_console = {
3097 	.name           = "early_ttySC",
3098 	.write          = serial_console_write,
3099 	.flags          = CON_PRINTBUFFER,
3100 	.index		= -1,
3101 };
3102 
3103 static char early_serial_buf[32];
3104 
3105 static int sci_probe_earlyprintk(struct platform_device *pdev)
3106 {
3107 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3108 
3109 	if (early_serial_console.data)
3110 		return -EEXIST;
3111 
3112 	early_serial_console.index = pdev->id;
3113 
3114 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3115 
3116 	serial_console_setup(&early_serial_console, early_serial_buf);
3117 
3118 	if (!strstr(early_serial_buf, "keep"))
3119 		early_serial_console.flags |= CON_BOOT;
3120 
3121 	register_console(&early_serial_console);
3122 	return 0;
3123 }
3124 #endif
3125 
3126 #define SCI_CONSOLE	(&serial_console)
3127 
3128 #else
3129 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3130 {
3131 	return -EINVAL;
3132 }
3133 
3134 #define SCI_CONSOLE	NULL
3135 
3136 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3137 
3138 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3139 
3140 static DEFINE_MUTEX(sci_uart_registration_lock);
3141 static struct uart_driver sci_uart_driver = {
3142 	.owner		= THIS_MODULE,
3143 	.driver_name	= "sci",
3144 	.dev_name	= "ttySC",
3145 	.major		= SCI_MAJOR,
3146 	.minor		= SCI_MINOR_START,
3147 	.nr		= SCI_NPORTS,
3148 	.cons		= SCI_CONSOLE,
3149 };
3150 
3151 static int sci_remove(struct platform_device *dev)
3152 {
3153 	struct sci_port *port = platform_get_drvdata(dev);
3154 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3155 
3156 	sci_ports_in_use &= ~BIT(port->port.line);
3157 	uart_remove_one_port(&sci_uart_driver, &port->port);
3158 
3159 	sci_cleanup_single(port);
3160 
3161 	if (port->port.fifosize > 1)
3162 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3163 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3164 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3165 
3166 	return 0;
3167 }
3168 
3169 
3170 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3171 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3172 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3173 
3174 static const struct of_device_id of_sci_match[] = {
3175 	/* SoC-specific types */
3176 	{
3177 		.compatible = "renesas,scif-r7s72100",
3178 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3179 	},
3180 	{
3181 		.compatible = "renesas,scif-r7s9210",
3182 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3183 	},
3184 	/* Family-specific types */
3185 	{
3186 		.compatible = "renesas,rcar-gen1-scif",
3187 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3188 	}, {
3189 		.compatible = "renesas,rcar-gen2-scif",
3190 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3191 	}, {
3192 		.compatible = "renesas,rcar-gen3-scif",
3193 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3194 	},
3195 	/* Generic types */
3196 	{
3197 		.compatible = "renesas,scif",
3198 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3199 	}, {
3200 		.compatible = "renesas,scifa",
3201 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3202 	}, {
3203 		.compatible = "renesas,scifb",
3204 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3205 	}, {
3206 		.compatible = "renesas,hscif",
3207 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3208 	}, {
3209 		.compatible = "renesas,sci",
3210 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3211 	}, {
3212 		/* Terminator */
3213 	},
3214 };
3215 MODULE_DEVICE_TABLE(of, of_sci_match);
3216 
3217 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3218 					  unsigned int *dev_id)
3219 {
3220 	struct device_node *np = pdev->dev.of_node;
3221 	struct plat_sci_port *p;
3222 	struct sci_port *sp;
3223 	const void *data;
3224 	int id;
3225 
3226 	if (!IS_ENABLED(CONFIG_OF) || !np)
3227 		return NULL;
3228 
3229 	data = of_device_get_match_data(&pdev->dev);
3230 
3231 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3232 	if (!p)
3233 		return NULL;
3234 
3235 	/* Get the line number from the aliases node. */
3236 	id = of_alias_get_id(np, "serial");
3237 	if (id < 0 && ~sci_ports_in_use)
3238 		id = ffz(sci_ports_in_use);
3239 	if (id < 0) {
3240 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3241 		return NULL;
3242 	}
3243 	if (id >= ARRAY_SIZE(sci_ports)) {
3244 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3245 		return NULL;
3246 	}
3247 
3248 	sp = &sci_ports[id];
3249 	*dev_id = id;
3250 
3251 	p->type = SCI_OF_TYPE(data);
3252 	p->regtype = SCI_OF_REGTYPE(data);
3253 
3254 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3255 
3256 	return p;
3257 }
3258 
3259 static int sci_probe_single(struct platform_device *dev,
3260 				      unsigned int index,
3261 				      struct plat_sci_port *p,
3262 				      struct sci_port *sciport)
3263 {
3264 	int ret;
3265 
3266 	/* Sanity check */
3267 	if (unlikely(index >= SCI_NPORTS)) {
3268 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3269 			   index+1, SCI_NPORTS);
3270 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3271 		return -EINVAL;
3272 	}
3273 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3274 	if (sci_ports_in_use & BIT(index))
3275 		return -EBUSY;
3276 
3277 	mutex_lock(&sci_uart_registration_lock);
3278 	if (!sci_uart_driver.state) {
3279 		ret = uart_register_driver(&sci_uart_driver);
3280 		if (ret) {
3281 			mutex_unlock(&sci_uart_registration_lock);
3282 			return ret;
3283 		}
3284 	}
3285 	mutex_unlock(&sci_uart_registration_lock);
3286 
3287 	ret = sci_init_single(dev, sciport, index, p, false);
3288 	if (ret)
3289 		return ret;
3290 
3291 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3292 	if (IS_ERR(sciport->gpios))
3293 		return PTR_ERR(sciport->gpios);
3294 
3295 	if (sciport->has_rtscts) {
3296 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3297 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3298 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3299 			return -EINVAL;
3300 		}
3301 		sciport->port.flags |= UPF_HARD_FLOW;
3302 	}
3303 
3304 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3305 	if (ret) {
3306 		sci_cleanup_single(sciport);
3307 		return ret;
3308 	}
3309 
3310 	return 0;
3311 }
3312 
3313 static int sci_probe(struct platform_device *dev)
3314 {
3315 	struct plat_sci_port *p;
3316 	struct sci_port *sp;
3317 	unsigned int dev_id;
3318 	int ret;
3319 
3320 	/*
3321 	 * If we've come here via earlyprintk initialization, head off to
3322 	 * the special early probe. We don't have sufficient device state
3323 	 * to make it beyond this yet.
3324 	 */
3325 #ifdef CONFIG_SUPERH
3326 	if (is_sh_early_platform_device(dev))
3327 		return sci_probe_earlyprintk(dev);
3328 #endif
3329 
3330 	if (dev->dev.of_node) {
3331 		p = sci_parse_dt(dev, &dev_id);
3332 		if (p == NULL)
3333 			return -EINVAL;
3334 	} else {
3335 		p = dev->dev.platform_data;
3336 		if (p == NULL) {
3337 			dev_err(&dev->dev, "no platform data supplied\n");
3338 			return -EINVAL;
3339 		}
3340 
3341 		dev_id = dev->id;
3342 	}
3343 
3344 	sp = &sci_ports[dev_id];
3345 	platform_set_drvdata(dev, sp);
3346 
3347 	ret = sci_probe_single(dev, dev_id, p, sp);
3348 	if (ret)
3349 		return ret;
3350 
3351 	if (sp->port.fifosize > 1) {
3352 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3353 		if (ret)
3354 			return ret;
3355 	}
3356 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3357 	    sp->port.type == PORT_HSCIF) {
3358 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3359 		if (ret) {
3360 			if (sp->port.fifosize > 1) {
3361 				device_remove_file(&dev->dev,
3362 						   &dev_attr_rx_fifo_trigger);
3363 			}
3364 			return ret;
3365 		}
3366 	}
3367 
3368 #ifdef CONFIG_SH_STANDARD_BIOS
3369 	sh_bios_gdb_detach();
3370 #endif
3371 
3372 	sci_ports_in_use |= BIT(dev_id);
3373 	return 0;
3374 }
3375 
3376 static __maybe_unused int sci_suspend(struct device *dev)
3377 {
3378 	struct sci_port *sport = dev_get_drvdata(dev);
3379 
3380 	if (sport)
3381 		uart_suspend_port(&sci_uart_driver, &sport->port);
3382 
3383 	return 0;
3384 }
3385 
3386 static __maybe_unused int sci_resume(struct device *dev)
3387 {
3388 	struct sci_port *sport = dev_get_drvdata(dev);
3389 
3390 	if (sport)
3391 		uart_resume_port(&sci_uart_driver, &sport->port);
3392 
3393 	return 0;
3394 }
3395 
3396 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3397 
3398 static struct platform_driver sci_driver = {
3399 	.probe		= sci_probe,
3400 	.remove		= sci_remove,
3401 	.driver		= {
3402 		.name	= "sh-sci",
3403 		.pm	= &sci_dev_pm_ops,
3404 		.of_match_table = of_match_ptr(of_sci_match),
3405 	},
3406 };
3407 
3408 static int __init sci_init(void)
3409 {
3410 	pr_info("%s\n", banner);
3411 
3412 	return platform_driver_register(&sci_driver);
3413 }
3414 
3415 static void __exit sci_exit(void)
3416 {
3417 	platform_driver_unregister(&sci_driver);
3418 
3419 	if (sci_uart_driver.state)
3420 		uart_unregister_driver(&sci_uart_driver);
3421 }
3422 
3423 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3424 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3425 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3426 #endif
3427 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3428 static struct plat_sci_port port_cfg __initdata;
3429 
3430 static int __init early_console_setup(struct earlycon_device *device,
3431 				      int type)
3432 {
3433 	if (!device->port.membase)
3434 		return -ENODEV;
3435 
3436 	device->port.serial_in = sci_serial_in;
3437 	device->port.serial_out	= sci_serial_out;
3438 	device->port.type = type;
3439 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3440 	port_cfg.type = type;
3441 	sci_ports[0].cfg = &port_cfg;
3442 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3443 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3444 	sci_serial_out(&sci_ports[0].port, SCSCR,
3445 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3446 
3447 	device->con->write = serial_console_write;
3448 	return 0;
3449 }
3450 static int __init sci_early_console_setup(struct earlycon_device *device,
3451 					  const char *opt)
3452 {
3453 	return early_console_setup(device, PORT_SCI);
3454 }
3455 static int __init scif_early_console_setup(struct earlycon_device *device,
3456 					  const char *opt)
3457 {
3458 	return early_console_setup(device, PORT_SCIF);
3459 }
3460 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3461 					  const char *opt)
3462 {
3463 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3464 	return early_console_setup(device, PORT_SCIF);
3465 }
3466 static int __init scifa_early_console_setup(struct earlycon_device *device,
3467 					  const char *opt)
3468 {
3469 	return early_console_setup(device, PORT_SCIFA);
3470 }
3471 static int __init scifb_early_console_setup(struct earlycon_device *device,
3472 					  const char *opt)
3473 {
3474 	return early_console_setup(device, PORT_SCIFB);
3475 }
3476 static int __init hscif_early_console_setup(struct earlycon_device *device,
3477 					  const char *opt)
3478 {
3479 	return early_console_setup(device, PORT_HSCIF);
3480 }
3481 
3482 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3483 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3484 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3485 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3486 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3487 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3488 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3489 
3490 module_init(sci_init);
3491 module_exit(sci_exit);
3492 
3493 MODULE_LICENSE("GPL");
3494 MODULE_ALIAS("platform:sh-sci");
3495 MODULE_AUTHOR("Paul Mundt");
3496 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3497