xref: /linux/drivers/tty/serial/sh-sci.c (revision 1f2367a39f17bd553a75e179a747f9b257bc9478)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 #define SUPPORT_SYSRQ
20 #endif
21 
22 #undef DEBUG
23 
24 #include <linux/clk.h>
25 #include <linux/console.h>
26 #include <linux/ctype.h>
27 #include <linux/cpufreq.h>
28 #include <linux/delay.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/err.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/ioport.h>
36 #include <linux/ktime.h>
37 #include <linux/major.h>
38 #include <linux/module.h>
39 #include <linux/mm.h>
40 #include <linux/of.h>
41 #include <linux/of_device.h>
42 #include <linux/platform_device.h>
43 #include <linux/pm_runtime.h>
44 #include <linux/scatterlist.h>
45 #include <linux/serial.h>
46 #include <linux/serial_sci.h>
47 #include <linux/sh_dma.h>
48 #include <linux/slab.h>
49 #include <linux/string.h>
50 #include <linux/sysrq.h>
51 #include <linux/timer.h>
52 #include <linux/tty.h>
53 #include <linux/tty_flip.h>
54 
55 #ifdef CONFIG_SUPERH
56 #include <asm/sh_bios.h>
57 #endif
58 
59 #include "serial_mctrl_gpio.h"
60 #include "sh-sci.h"
61 
62 /* Offsets into the sci_port->irqs array */
63 enum {
64 	SCIx_ERI_IRQ,
65 	SCIx_RXI_IRQ,
66 	SCIx_TXI_IRQ,
67 	SCIx_BRI_IRQ,
68 	SCIx_DRI_IRQ,
69 	SCIx_TEI_IRQ,
70 	SCIx_NR_IRQS,
71 
72 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
73 };
74 
75 #define SCIx_IRQ_IS_MUXED(port)			\
76 	((port)->irqs[SCIx_ERI_IRQ] ==	\
77 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
78 	((port)->irqs[SCIx_ERI_IRQ] &&	\
79 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
80 
81 enum SCI_CLKS {
82 	SCI_FCK,		/* Functional Clock */
83 	SCI_SCK,		/* Optional External Clock */
84 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
85 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
86 	SCI_NUM_CLKS
87 };
88 
89 /* Bit x set means sampling rate x + 1 is supported */
90 #define SCI_SR(x)		BIT((x) - 1)
91 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
92 
93 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
94 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
95 				SCI_SR(19) | SCI_SR(27)
96 
97 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
98 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
99 
100 /* Iterate over all supported sampling rates, from high to low */
101 #define for_each_sr(_sr, _port)						\
102 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
103 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
104 
105 struct plat_sci_reg {
106 	u8 offset, size;
107 };
108 
109 struct sci_port_params {
110 	const struct plat_sci_reg regs[SCIx_NR_REGS];
111 	unsigned int fifosize;
112 	unsigned int overrun_reg;
113 	unsigned int overrun_mask;
114 	unsigned int sampling_rate_mask;
115 	unsigned int error_mask;
116 	unsigned int error_clear;
117 };
118 
119 struct sci_port {
120 	struct uart_port	port;
121 
122 	/* Platform configuration */
123 	const struct sci_port_params *params;
124 	const struct plat_sci_port *cfg;
125 	unsigned int		sampling_rate_mask;
126 	resource_size_t		reg_size;
127 	struct mctrl_gpios	*gpios;
128 
129 	/* Clocks */
130 	struct clk		*clks[SCI_NUM_CLKS];
131 	unsigned long		clk_rates[SCI_NUM_CLKS];
132 
133 	int			irqs[SCIx_NR_IRQS];
134 	char			*irqstr[SCIx_NR_IRQS];
135 
136 	struct dma_chan			*chan_tx;
137 	struct dma_chan			*chan_rx;
138 
139 #ifdef CONFIG_SERIAL_SH_SCI_DMA
140 	struct dma_chan			*chan_tx_saved;
141 	struct dma_chan			*chan_rx_saved;
142 	dma_cookie_t			cookie_tx;
143 	dma_cookie_t			cookie_rx[2];
144 	dma_cookie_t			active_rx;
145 	dma_addr_t			tx_dma_addr;
146 	unsigned int			tx_dma_len;
147 	struct scatterlist		sg_rx[2];
148 	void				*rx_buf[2];
149 	size_t				buf_len_rx;
150 	struct work_struct		work_tx;
151 	struct hrtimer			rx_timer;
152 	unsigned int			rx_timeout;	/* microseconds */
153 #endif
154 	unsigned int			rx_frame;
155 	int				rx_trigger;
156 	struct timer_list		rx_fifo_timer;
157 	int				rx_fifo_timeout;
158 	u16				hscif_tot;
159 
160 	bool has_rtscts;
161 	bool autorts;
162 };
163 
164 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
165 
166 static struct sci_port sci_ports[SCI_NPORTS];
167 static unsigned long sci_ports_in_use;
168 static struct uart_driver sci_uart_driver;
169 
170 static inline struct sci_port *
171 to_sci_port(struct uart_port *uart)
172 {
173 	return container_of(uart, struct sci_port, port);
174 }
175 
176 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
177 	/*
178 	 * Common SCI definitions, dependent on the port's regshift
179 	 * value.
180 	 */
181 	[SCIx_SCI_REGTYPE] = {
182 		.regs = {
183 			[SCSMR]		= { 0x00,  8 },
184 			[SCBRR]		= { 0x01,  8 },
185 			[SCSCR]		= { 0x02,  8 },
186 			[SCxTDR]	= { 0x03,  8 },
187 			[SCxSR]		= { 0x04,  8 },
188 			[SCxRDR]	= { 0x05,  8 },
189 		},
190 		.fifosize = 1,
191 		.overrun_reg = SCxSR,
192 		.overrun_mask = SCI_ORER,
193 		.sampling_rate_mask = SCI_SR(32),
194 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
195 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
196 	},
197 
198 	/*
199 	 * Common definitions for legacy IrDA ports.
200 	 */
201 	[SCIx_IRDA_REGTYPE] = {
202 		.regs = {
203 			[SCSMR]		= { 0x00,  8 },
204 			[SCBRR]		= { 0x02,  8 },
205 			[SCSCR]		= { 0x04,  8 },
206 			[SCxTDR]	= { 0x06,  8 },
207 			[SCxSR]		= { 0x08, 16 },
208 			[SCxRDR]	= { 0x0a,  8 },
209 			[SCFCR]		= { 0x0c,  8 },
210 			[SCFDR]		= { 0x0e, 16 },
211 		},
212 		.fifosize = 1,
213 		.overrun_reg = SCxSR,
214 		.overrun_mask = SCI_ORER,
215 		.sampling_rate_mask = SCI_SR(32),
216 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
217 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
218 	},
219 
220 	/*
221 	 * Common SCIFA definitions.
222 	 */
223 	[SCIx_SCIFA_REGTYPE] = {
224 		.regs = {
225 			[SCSMR]		= { 0x00, 16 },
226 			[SCBRR]		= { 0x04,  8 },
227 			[SCSCR]		= { 0x08, 16 },
228 			[SCxTDR]	= { 0x20,  8 },
229 			[SCxSR]		= { 0x14, 16 },
230 			[SCxRDR]	= { 0x24,  8 },
231 			[SCFCR]		= { 0x18, 16 },
232 			[SCFDR]		= { 0x1c, 16 },
233 			[SCPCR]		= { 0x30, 16 },
234 			[SCPDR]		= { 0x34, 16 },
235 		},
236 		.fifosize = 64,
237 		.overrun_reg = SCxSR,
238 		.overrun_mask = SCIFA_ORER,
239 		.sampling_rate_mask = SCI_SR_SCIFAB,
240 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
241 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
242 	},
243 
244 	/*
245 	 * Common SCIFB definitions.
246 	 */
247 	[SCIx_SCIFB_REGTYPE] = {
248 		.regs = {
249 			[SCSMR]		= { 0x00, 16 },
250 			[SCBRR]		= { 0x04,  8 },
251 			[SCSCR]		= { 0x08, 16 },
252 			[SCxTDR]	= { 0x40,  8 },
253 			[SCxSR]		= { 0x14, 16 },
254 			[SCxRDR]	= { 0x60,  8 },
255 			[SCFCR]		= { 0x18, 16 },
256 			[SCTFDR]	= { 0x38, 16 },
257 			[SCRFDR]	= { 0x3c, 16 },
258 			[SCPCR]		= { 0x30, 16 },
259 			[SCPDR]		= { 0x34, 16 },
260 		},
261 		.fifosize = 256,
262 		.overrun_reg = SCxSR,
263 		.overrun_mask = SCIFA_ORER,
264 		.sampling_rate_mask = SCI_SR_SCIFAB,
265 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
266 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
267 	},
268 
269 	/*
270 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
271 	 * count registers.
272 	 */
273 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
274 		.regs = {
275 			[SCSMR]		= { 0x00, 16 },
276 			[SCBRR]		= { 0x04,  8 },
277 			[SCSCR]		= { 0x08, 16 },
278 			[SCxTDR]	= { 0x0c,  8 },
279 			[SCxSR]		= { 0x10, 16 },
280 			[SCxRDR]	= { 0x14,  8 },
281 			[SCFCR]		= { 0x18, 16 },
282 			[SCFDR]		= { 0x1c, 16 },
283 			[SCSPTR]	= { 0x20, 16 },
284 			[SCLSR]		= { 0x24, 16 },
285 		},
286 		.fifosize = 16,
287 		.overrun_reg = SCLSR,
288 		.overrun_mask = SCLSR_ORER,
289 		.sampling_rate_mask = SCI_SR(32),
290 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
291 		.error_clear = SCIF_ERROR_CLEAR,
292 	},
293 
294 	/*
295 	 * The "SCIFA" that is in RZ/T and RZ/A2.
296 	 * It looks like a normal SCIF with FIFO data, but with a
297 	 * compressed address space. Also, the break out of interrupts
298 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
299 	 */
300 	[SCIx_RZ_SCIFA_REGTYPE] = {
301 		.regs = {
302 			[SCSMR]		= { 0x00, 16 },
303 			[SCBRR]		= { 0x02,  8 },
304 			[SCSCR]		= { 0x04, 16 },
305 			[SCxTDR]	= { 0x06,  8 },
306 			[SCxSR]		= { 0x08, 16 },
307 			[SCxRDR]	= { 0x0A,  8 },
308 			[SCFCR]		= { 0x0C, 16 },
309 			[SCFDR]		= { 0x0E, 16 },
310 			[SCSPTR]	= { 0x10, 16 },
311 			[SCLSR]		= { 0x12, 16 },
312 		},
313 		.fifosize = 16,
314 		.overrun_reg = SCLSR,
315 		.overrun_mask = SCLSR_ORER,
316 		.sampling_rate_mask = SCI_SR(32),
317 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
318 		.error_clear = SCIF_ERROR_CLEAR,
319 	},
320 
321 	/*
322 	 * Common SH-3 SCIF definitions.
323 	 */
324 	[SCIx_SH3_SCIF_REGTYPE] = {
325 		.regs = {
326 			[SCSMR]		= { 0x00,  8 },
327 			[SCBRR]		= { 0x02,  8 },
328 			[SCSCR]		= { 0x04,  8 },
329 			[SCxTDR]	= { 0x06,  8 },
330 			[SCxSR]		= { 0x08, 16 },
331 			[SCxRDR]	= { 0x0a,  8 },
332 			[SCFCR]		= { 0x0c,  8 },
333 			[SCFDR]		= { 0x0e, 16 },
334 		},
335 		.fifosize = 16,
336 		.overrun_reg = SCLSR,
337 		.overrun_mask = SCLSR_ORER,
338 		.sampling_rate_mask = SCI_SR(32),
339 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
340 		.error_clear = SCIF_ERROR_CLEAR,
341 	},
342 
343 	/*
344 	 * Common SH-4(A) SCIF(B) definitions.
345 	 */
346 	[SCIx_SH4_SCIF_REGTYPE] = {
347 		.regs = {
348 			[SCSMR]		= { 0x00, 16 },
349 			[SCBRR]		= { 0x04,  8 },
350 			[SCSCR]		= { 0x08, 16 },
351 			[SCxTDR]	= { 0x0c,  8 },
352 			[SCxSR]		= { 0x10, 16 },
353 			[SCxRDR]	= { 0x14,  8 },
354 			[SCFCR]		= { 0x18, 16 },
355 			[SCFDR]		= { 0x1c, 16 },
356 			[SCSPTR]	= { 0x20, 16 },
357 			[SCLSR]		= { 0x24, 16 },
358 		},
359 		.fifosize = 16,
360 		.overrun_reg = SCLSR,
361 		.overrun_mask = SCLSR_ORER,
362 		.sampling_rate_mask = SCI_SR(32),
363 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
364 		.error_clear = SCIF_ERROR_CLEAR,
365 	},
366 
367 	/*
368 	 * Common SCIF definitions for ports with a Baud Rate Generator for
369 	 * External Clock (BRG).
370 	 */
371 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
372 		.regs = {
373 			[SCSMR]		= { 0x00, 16 },
374 			[SCBRR]		= { 0x04,  8 },
375 			[SCSCR]		= { 0x08, 16 },
376 			[SCxTDR]	= { 0x0c,  8 },
377 			[SCxSR]		= { 0x10, 16 },
378 			[SCxRDR]	= { 0x14,  8 },
379 			[SCFCR]		= { 0x18, 16 },
380 			[SCFDR]		= { 0x1c, 16 },
381 			[SCSPTR]	= { 0x20, 16 },
382 			[SCLSR]		= { 0x24, 16 },
383 			[SCDL]		= { 0x30, 16 },
384 			[SCCKS]		= { 0x34, 16 },
385 		},
386 		.fifosize = 16,
387 		.overrun_reg = SCLSR,
388 		.overrun_mask = SCLSR_ORER,
389 		.sampling_rate_mask = SCI_SR(32),
390 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
391 		.error_clear = SCIF_ERROR_CLEAR,
392 	},
393 
394 	/*
395 	 * Common HSCIF definitions.
396 	 */
397 	[SCIx_HSCIF_REGTYPE] = {
398 		.regs = {
399 			[SCSMR]		= { 0x00, 16 },
400 			[SCBRR]		= { 0x04,  8 },
401 			[SCSCR]		= { 0x08, 16 },
402 			[SCxTDR]	= { 0x0c,  8 },
403 			[SCxSR]		= { 0x10, 16 },
404 			[SCxRDR]	= { 0x14,  8 },
405 			[SCFCR]		= { 0x18, 16 },
406 			[SCFDR]		= { 0x1c, 16 },
407 			[SCSPTR]	= { 0x20, 16 },
408 			[SCLSR]		= { 0x24, 16 },
409 			[HSSRR]		= { 0x40, 16 },
410 			[SCDL]		= { 0x30, 16 },
411 			[SCCKS]		= { 0x34, 16 },
412 			[HSRTRGR]	= { 0x54, 16 },
413 			[HSTTRGR]	= { 0x58, 16 },
414 		},
415 		.fifosize = 128,
416 		.overrun_reg = SCLSR,
417 		.overrun_mask = SCLSR_ORER,
418 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
419 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
420 		.error_clear = SCIF_ERROR_CLEAR,
421 	},
422 
423 	/*
424 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
425 	 * register.
426 	 */
427 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
428 		.regs = {
429 			[SCSMR]		= { 0x00, 16 },
430 			[SCBRR]		= { 0x04,  8 },
431 			[SCSCR]		= { 0x08, 16 },
432 			[SCxTDR]	= { 0x0c,  8 },
433 			[SCxSR]		= { 0x10, 16 },
434 			[SCxRDR]	= { 0x14,  8 },
435 			[SCFCR]		= { 0x18, 16 },
436 			[SCFDR]		= { 0x1c, 16 },
437 			[SCLSR]		= { 0x24, 16 },
438 		},
439 		.fifosize = 16,
440 		.overrun_reg = SCLSR,
441 		.overrun_mask = SCLSR_ORER,
442 		.sampling_rate_mask = SCI_SR(32),
443 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
444 		.error_clear = SCIF_ERROR_CLEAR,
445 	},
446 
447 	/*
448 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
449 	 * count registers.
450 	 */
451 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
452 		.regs = {
453 			[SCSMR]		= { 0x00, 16 },
454 			[SCBRR]		= { 0x04,  8 },
455 			[SCSCR]		= { 0x08, 16 },
456 			[SCxTDR]	= { 0x0c,  8 },
457 			[SCxSR]		= { 0x10, 16 },
458 			[SCxRDR]	= { 0x14,  8 },
459 			[SCFCR]		= { 0x18, 16 },
460 			[SCFDR]		= { 0x1c, 16 },
461 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
462 			[SCRFDR]	= { 0x20, 16 },
463 			[SCSPTR]	= { 0x24, 16 },
464 			[SCLSR]		= { 0x28, 16 },
465 		},
466 		.fifosize = 16,
467 		.overrun_reg = SCLSR,
468 		.overrun_mask = SCLSR_ORER,
469 		.sampling_rate_mask = SCI_SR(32),
470 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
471 		.error_clear = SCIF_ERROR_CLEAR,
472 	},
473 
474 	/*
475 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
476 	 * registers.
477 	 */
478 	[SCIx_SH7705_SCIF_REGTYPE] = {
479 		.regs = {
480 			[SCSMR]		= { 0x00, 16 },
481 			[SCBRR]		= { 0x04,  8 },
482 			[SCSCR]		= { 0x08, 16 },
483 			[SCxTDR]	= { 0x20,  8 },
484 			[SCxSR]		= { 0x14, 16 },
485 			[SCxRDR]	= { 0x24,  8 },
486 			[SCFCR]		= { 0x18, 16 },
487 			[SCFDR]		= { 0x1c, 16 },
488 		},
489 		.fifosize = 64,
490 		.overrun_reg = SCxSR,
491 		.overrun_mask = SCIFA_ORER,
492 		.sampling_rate_mask = SCI_SR(16),
493 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
494 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
495 	},
496 };
497 
498 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
499 
500 /*
501  * The "offset" here is rather misleading, in that it refers to an enum
502  * value relative to the port mapping rather than the fixed offset
503  * itself, which needs to be manually retrieved from the platform's
504  * register map for the given port.
505  */
506 static unsigned int sci_serial_in(struct uart_port *p, int offset)
507 {
508 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
509 
510 	if (reg->size == 8)
511 		return ioread8(p->membase + (reg->offset << p->regshift));
512 	else if (reg->size == 16)
513 		return ioread16(p->membase + (reg->offset << p->regshift));
514 	else
515 		WARN(1, "Invalid register access\n");
516 
517 	return 0;
518 }
519 
520 static void sci_serial_out(struct uart_port *p, int offset, int value)
521 {
522 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
523 
524 	if (reg->size == 8)
525 		iowrite8(value, p->membase + (reg->offset << p->regshift));
526 	else if (reg->size == 16)
527 		iowrite16(value, p->membase + (reg->offset << p->regshift));
528 	else
529 		WARN(1, "Invalid register access\n");
530 }
531 
532 static void sci_port_enable(struct sci_port *sci_port)
533 {
534 	unsigned int i;
535 
536 	if (!sci_port->port.dev)
537 		return;
538 
539 	pm_runtime_get_sync(sci_port->port.dev);
540 
541 	for (i = 0; i < SCI_NUM_CLKS; i++) {
542 		clk_prepare_enable(sci_port->clks[i]);
543 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
544 	}
545 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
546 }
547 
548 static void sci_port_disable(struct sci_port *sci_port)
549 {
550 	unsigned int i;
551 
552 	if (!sci_port->port.dev)
553 		return;
554 
555 	for (i = SCI_NUM_CLKS; i-- > 0; )
556 		clk_disable_unprepare(sci_port->clks[i]);
557 
558 	pm_runtime_put_sync(sci_port->port.dev);
559 }
560 
561 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
562 {
563 	/*
564 	 * Not all ports (such as SCIFA) will support REIE. Rather than
565 	 * special-casing the port type, we check the port initialization
566 	 * IRQ enable mask to see whether the IRQ is desired at all. If
567 	 * it's unset, it's logically inferred that there's no point in
568 	 * testing for it.
569 	 */
570 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
571 }
572 
573 static void sci_start_tx(struct uart_port *port)
574 {
575 	struct sci_port *s = to_sci_port(port);
576 	unsigned short ctrl;
577 
578 #ifdef CONFIG_SERIAL_SH_SCI_DMA
579 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
580 		u16 new, scr = serial_port_in(port, SCSCR);
581 		if (s->chan_tx)
582 			new = scr | SCSCR_TDRQE;
583 		else
584 			new = scr & ~SCSCR_TDRQE;
585 		if (new != scr)
586 			serial_port_out(port, SCSCR, new);
587 	}
588 
589 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
590 	    dma_submit_error(s->cookie_tx)) {
591 		s->cookie_tx = 0;
592 		schedule_work(&s->work_tx);
593 	}
594 #endif
595 
596 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
597 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
598 		ctrl = serial_port_in(port, SCSCR);
599 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
600 	}
601 }
602 
603 static void sci_stop_tx(struct uart_port *port)
604 {
605 	unsigned short ctrl;
606 
607 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
608 	ctrl = serial_port_in(port, SCSCR);
609 
610 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
611 		ctrl &= ~SCSCR_TDRQE;
612 
613 	ctrl &= ~SCSCR_TIE;
614 
615 	serial_port_out(port, SCSCR, ctrl);
616 }
617 
618 static void sci_start_rx(struct uart_port *port)
619 {
620 	unsigned short ctrl;
621 
622 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
623 
624 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
625 		ctrl &= ~SCSCR_RDRQE;
626 
627 	serial_port_out(port, SCSCR, ctrl);
628 }
629 
630 static void sci_stop_rx(struct uart_port *port)
631 {
632 	unsigned short ctrl;
633 
634 	ctrl = serial_port_in(port, SCSCR);
635 
636 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
637 		ctrl &= ~SCSCR_RDRQE;
638 
639 	ctrl &= ~port_rx_irq_mask(port);
640 
641 	serial_port_out(port, SCSCR, ctrl);
642 }
643 
644 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
645 {
646 	if (port->type == PORT_SCI) {
647 		/* Just store the mask */
648 		serial_port_out(port, SCxSR, mask);
649 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
650 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
651 		/* Only clear the status bits we want to clear */
652 		serial_port_out(port, SCxSR,
653 				serial_port_in(port, SCxSR) & mask);
654 	} else {
655 		/* Store the mask, clear parity/framing errors */
656 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
657 	}
658 }
659 
660 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
661     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
662 
663 #ifdef CONFIG_CONSOLE_POLL
664 static int sci_poll_get_char(struct uart_port *port)
665 {
666 	unsigned short status;
667 	int c;
668 
669 	do {
670 		status = serial_port_in(port, SCxSR);
671 		if (status & SCxSR_ERRORS(port)) {
672 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
673 			continue;
674 		}
675 		break;
676 	} while (1);
677 
678 	if (!(status & SCxSR_RDxF(port)))
679 		return NO_POLL_CHAR;
680 
681 	c = serial_port_in(port, SCxRDR);
682 
683 	/* Dummy read */
684 	serial_port_in(port, SCxSR);
685 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
686 
687 	return c;
688 }
689 #endif
690 
691 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
692 {
693 	unsigned short status;
694 
695 	do {
696 		status = serial_port_in(port, SCxSR);
697 	} while (!(status & SCxSR_TDxE(port)));
698 
699 	serial_port_out(port, SCxTDR, c);
700 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
701 }
702 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
703 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
704 
705 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
706 {
707 	struct sci_port *s = to_sci_port(port);
708 
709 	/*
710 	 * Use port-specific handler if provided.
711 	 */
712 	if (s->cfg->ops && s->cfg->ops->init_pins) {
713 		s->cfg->ops->init_pins(port, cflag);
714 		return;
715 	}
716 
717 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
718 		u16 data = serial_port_in(port, SCPDR);
719 		u16 ctrl = serial_port_in(port, SCPCR);
720 
721 		/* Enable RXD and TXD pin functions */
722 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
723 		if (to_sci_port(port)->has_rtscts) {
724 			/* RTS# is output, active low, unless autorts */
725 			if (!(port->mctrl & TIOCM_RTS)) {
726 				ctrl |= SCPCR_RTSC;
727 				data |= SCPDR_RTSD;
728 			} else if (!s->autorts) {
729 				ctrl |= SCPCR_RTSC;
730 				data &= ~SCPDR_RTSD;
731 			} else {
732 				/* Enable RTS# pin function */
733 				ctrl &= ~SCPCR_RTSC;
734 			}
735 			/* Enable CTS# pin function */
736 			ctrl &= ~SCPCR_CTSC;
737 		}
738 		serial_port_out(port, SCPDR, data);
739 		serial_port_out(port, SCPCR, ctrl);
740 	} else if (sci_getreg(port, SCSPTR)->size) {
741 		u16 status = serial_port_in(port, SCSPTR);
742 
743 		/* RTS# is always output; and active low, unless autorts */
744 		status |= SCSPTR_RTSIO;
745 		if (!(port->mctrl & TIOCM_RTS))
746 			status |= SCSPTR_RTSDT;
747 		else if (!s->autorts)
748 			status &= ~SCSPTR_RTSDT;
749 		/* CTS# and SCK are inputs */
750 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
751 		serial_port_out(port, SCSPTR, status);
752 	}
753 }
754 
755 static int sci_txfill(struct uart_port *port)
756 {
757 	struct sci_port *s = to_sci_port(port);
758 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
759 	const struct plat_sci_reg *reg;
760 
761 	reg = sci_getreg(port, SCTFDR);
762 	if (reg->size)
763 		return serial_port_in(port, SCTFDR) & fifo_mask;
764 
765 	reg = sci_getreg(port, SCFDR);
766 	if (reg->size)
767 		return serial_port_in(port, SCFDR) >> 8;
768 
769 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
770 }
771 
772 static int sci_txroom(struct uart_port *port)
773 {
774 	return port->fifosize - sci_txfill(port);
775 }
776 
777 static int sci_rxfill(struct uart_port *port)
778 {
779 	struct sci_port *s = to_sci_port(port);
780 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
781 	const struct plat_sci_reg *reg;
782 
783 	reg = sci_getreg(port, SCRFDR);
784 	if (reg->size)
785 		return serial_port_in(port, SCRFDR) & fifo_mask;
786 
787 	reg = sci_getreg(port, SCFDR);
788 	if (reg->size)
789 		return serial_port_in(port, SCFDR) & fifo_mask;
790 
791 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
792 }
793 
794 /* ********************************************************************** *
795  *                   the interrupt related routines                       *
796  * ********************************************************************** */
797 
798 static void sci_transmit_chars(struct uart_port *port)
799 {
800 	struct circ_buf *xmit = &port->state->xmit;
801 	unsigned int stopped = uart_tx_stopped(port);
802 	unsigned short status;
803 	unsigned short ctrl;
804 	int count;
805 
806 	status = serial_port_in(port, SCxSR);
807 	if (!(status & SCxSR_TDxE(port))) {
808 		ctrl = serial_port_in(port, SCSCR);
809 		if (uart_circ_empty(xmit))
810 			ctrl &= ~SCSCR_TIE;
811 		else
812 			ctrl |= SCSCR_TIE;
813 		serial_port_out(port, SCSCR, ctrl);
814 		return;
815 	}
816 
817 	count = sci_txroom(port);
818 
819 	do {
820 		unsigned char c;
821 
822 		if (port->x_char) {
823 			c = port->x_char;
824 			port->x_char = 0;
825 		} else if (!uart_circ_empty(xmit) && !stopped) {
826 			c = xmit->buf[xmit->tail];
827 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
828 		} else {
829 			break;
830 		}
831 
832 		serial_port_out(port, SCxTDR, c);
833 
834 		port->icount.tx++;
835 	} while (--count > 0);
836 
837 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
838 
839 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
840 		uart_write_wakeup(port);
841 	if (uart_circ_empty(xmit)) {
842 		sci_stop_tx(port);
843 	} else {
844 		ctrl = serial_port_in(port, SCSCR);
845 
846 		if (port->type != PORT_SCI) {
847 			serial_port_in(port, SCxSR); /* Dummy read */
848 			sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
849 		}
850 
851 		ctrl |= SCSCR_TIE;
852 		serial_port_out(port, SCSCR, ctrl);
853 	}
854 }
855 
856 /* On SH3, SCIF may read end-of-break as a space->mark char */
857 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
858 
859 static void sci_receive_chars(struct uart_port *port)
860 {
861 	struct tty_port *tport = &port->state->port;
862 	int i, count, copied = 0;
863 	unsigned short status;
864 	unsigned char flag;
865 
866 	status = serial_port_in(port, SCxSR);
867 	if (!(status & SCxSR_RDxF(port)))
868 		return;
869 
870 	while (1) {
871 		/* Don't copy more bytes than there is room for in the buffer */
872 		count = tty_buffer_request_room(tport, sci_rxfill(port));
873 
874 		/* If for any reason we can't copy more data, we're done! */
875 		if (count == 0)
876 			break;
877 
878 		if (port->type == PORT_SCI) {
879 			char c = serial_port_in(port, SCxRDR);
880 			if (uart_handle_sysrq_char(port, c))
881 				count = 0;
882 			else
883 				tty_insert_flip_char(tport, c, TTY_NORMAL);
884 		} else {
885 			for (i = 0; i < count; i++) {
886 				char c = serial_port_in(port, SCxRDR);
887 
888 				status = serial_port_in(port, SCxSR);
889 				if (uart_handle_sysrq_char(port, c)) {
890 					count--; i--;
891 					continue;
892 				}
893 
894 				/* Store data and status */
895 				if (status & SCxSR_FER(port)) {
896 					flag = TTY_FRAME;
897 					port->icount.frame++;
898 					dev_notice(port->dev, "frame error\n");
899 				} else if (status & SCxSR_PER(port)) {
900 					flag = TTY_PARITY;
901 					port->icount.parity++;
902 					dev_notice(port->dev, "parity error\n");
903 				} else
904 					flag = TTY_NORMAL;
905 
906 				tty_insert_flip_char(tport, c, flag);
907 			}
908 		}
909 
910 		serial_port_in(port, SCxSR); /* dummy read */
911 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
912 
913 		copied += count;
914 		port->icount.rx += count;
915 	}
916 
917 	if (copied) {
918 		/* Tell the rest of the system the news. New characters! */
919 		tty_flip_buffer_push(tport);
920 	} else {
921 		/* TTY buffers full; read from RX reg to prevent lockup */
922 		serial_port_in(port, SCxRDR);
923 		serial_port_in(port, SCxSR); /* dummy read */
924 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
925 	}
926 }
927 
928 static int sci_handle_errors(struct uart_port *port)
929 {
930 	int copied = 0;
931 	unsigned short status = serial_port_in(port, SCxSR);
932 	struct tty_port *tport = &port->state->port;
933 	struct sci_port *s = to_sci_port(port);
934 
935 	/* Handle overruns */
936 	if (status & s->params->overrun_mask) {
937 		port->icount.overrun++;
938 
939 		/* overrun error */
940 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
941 			copied++;
942 
943 		dev_notice(port->dev, "overrun error\n");
944 	}
945 
946 	if (status & SCxSR_FER(port)) {
947 		/* frame error */
948 		port->icount.frame++;
949 
950 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
951 			copied++;
952 
953 		dev_notice(port->dev, "frame error\n");
954 	}
955 
956 	if (status & SCxSR_PER(port)) {
957 		/* parity error */
958 		port->icount.parity++;
959 
960 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
961 			copied++;
962 
963 		dev_notice(port->dev, "parity error\n");
964 	}
965 
966 	if (copied)
967 		tty_flip_buffer_push(tport);
968 
969 	return copied;
970 }
971 
972 static int sci_handle_fifo_overrun(struct uart_port *port)
973 {
974 	struct tty_port *tport = &port->state->port;
975 	struct sci_port *s = to_sci_port(port);
976 	const struct plat_sci_reg *reg;
977 	int copied = 0;
978 	u16 status;
979 
980 	reg = sci_getreg(port, s->params->overrun_reg);
981 	if (!reg->size)
982 		return 0;
983 
984 	status = serial_port_in(port, s->params->overrun_reg);
985 	if (status & s->params->overrun_mask) {
986 		status &= ~s->params->overrun_mask;
987 		serial_port_out(port, s->params->overrun_reg, status);
988 
989 		port->icount.overrun++;
990 
991 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
992 		tty_flip_buffer_push(tport);
993 
994 		dev_dbg(port->dev, "overrun error\n");
995 		copied++;
996 	}
997 
998 	return copied;
999 }
1000 
1001 static int sci_handle_breaks(struct uart_port *port)
1002 {
1003 	int copied = 0;
1004 	unsigned short status = serial_port_in(port, SCxSR);
1005 	struct tty_port *tport = &port->state->port;
1006 
1007 	if (uart_handle_break(port))
1008 		return 0;
1009 
1010 	if (status & SCxSR_BRK(port)) {
1011 		port->icount.brk++;
1012 
1013 		/* Notify of BREAK */
1014 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1015 			copied++;
1016 
1017 		dev_dbg(port->dev, "BREAK detected\n");
1018 	}
1019 
1020 	if (copied)
1021 		tty_flip_buffer_push(tport);
1022 
1023 	copied += sci_handle_fifo_overrun(port);
1024 
1025 	return copied;
1026 }
1027 
1028 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1029 {
1030 	unsigned int bits;
1031 
1032 	if (rx_trig < 1)
1033 		rx_trig = 1;
1034 	if (rx_trig >= port->fifosize)
1035 		rx_trig = port->fifosize;
1036 
1037 	/* HSCIF can be set to an arbitrary level. */
1038 	if (sci_getreg(port, HSRTRGR)->size) {
1039 		serial_port_out(port, HSRTRGR, rx_trig);
1040 		return rx_trig;
1041 	}
1042 
1043 	switch (port->type) {
1044 	case PORT_SCIF:
1045 		if (rx_trig < 4) {
1046 			bits = 0;
1047 			rx_trig = 1;
1048 		} else if (rx_trig < 8) {
1049 			bits = SCFCR_RTRG0;
1050 			rx_trig = 4;
1051 		} else if (rx_trig < 14) {
1052 			bits = SCFCR_RTRG1;
1053 			rx_trig = 8;
1054 		} else {
1055 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1056 			rx_trig = 14;
1057 		}
1058 		break;
1059 	case PORT_SCIFA:
1060 	case PORT_SCIFB:
1061 		if (rx_trig < 16) {
1062 			bits = 0;
1063 			rx_trig = 1;
1064 		} else if (rx_trig < 32) {
1065 			bits = SCFCR_RTRG0;
1066 			rx_trig = 16;
1067 		} else if (rx_trig < 48) {
1068 			bits = SCFCR_RTRG1;
1069 			rx_trig = 32;
1070 		} else {
1071 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1072 			rx_trig = 48;
1073 		}
1074 		break;
1075 	default:
1076 		WARN(1, "unknown FIFO configuration");
1077 		return 1;
1078 	}
1079 
1080 	serial_port_out(port, SCFCR,
1081 		(serial_port_in(port, SCFCR) &
1082 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1083 
1084 	return rx_trig;
1085 }
1086 
1087 static int scif_rtrg_enabled(struct uart_port *port)
1088 {
1089 	if (sci_getreg(port, HSRTRGR)->size)
1090 		return serial_port_in(port, HSRTRGR) != 0;
1091 	else
1092 		return (serial_port_in(port, SCFCR) &
1093 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1094 }
1095 
1096 static void rx_fifo_timer_fn(struct timer_list *t)
1097 {
1098 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1099 	struct uart_port *port = &s->port;
1100 
1101 	dev_dbg(port->dev, "Rx timed out\n");
1102 	scif_set_rtrg(port, 1);
1103 }
1104 
1105 static ssize_t rx_trigger_show(struct device *dev,
1106 			       struct device_attribute *attr,
1107 			       char *buf)
1108 {
1109 	struct uart_port *port = dev_get_drvdata(dev);
1110 	struct sci_port *sci = to_sci_port(port);
1111 
1112 	return sprintf(buf, "%d\n", sci->rx_trigger);
1113 }
1114 
1115 static ssize_t rx_trigger_store(struct device *dev,
1116 				struct device_attribute *attr,
1117 				const char *buf,
1118 				size_t count)
1119 {
1120 	struct uart_port *port = dev_get_drvdata(dev);
1121 	struct sci_port *sci = to_sci_port(port);
1122 	int ret;
1123 	long r;
1124 
1125 	ret = kstrtol(buf, 0, &r);
1126 	if (ret)
1127 		return ret;
1128 
1129 	sci->rx_trigger = scif_set_rtrg(port, r);
1130 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1131 		scif_set_rtrg(port, 1);
1132 
1133 	return count;
1134 }
1135 
1136 static DEVICE_ATTR(rx_fifo_trigger, 0644, rx_trigger_show, rx_trigger_store);
1137 
1138 static ssize_t rx_fifo_timeout_show(struct device *dev,
1139 			       struct device_attribute *attr,
1140 			       char *buf)
1141 {
1142 	struct uart_port *port = dev_get_drvdata(dev);
1143 	struct sci_port *sci = to_sci_port(port);
1144 	int v;
1145 
1146 	if (port->type == PORT_HSCIF)
1147 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1148 	else
1149 		v = sci->rx_fifo_timeout;
1150 
1151 	return sprintf(buf, "%d\n", v);
1152 }
1153 
1154 static ssize_t rx_fifo_timeout_store(struct device *dev,
1155 				struct device_attribute *attr,
1156 				const char *buf,
1157 				size_t count)
1158 {
1159 	struct uart_port *port = dev_get_drvdata(dev);
1160 	struct sci_port *sci = to_sci_port(port);
1161 	int ret;
1162 	long r;
1163 
1164 	ret = kstrtol(buf, 0, &r);
1165 	if (ret)
1166 		return ret;
1167 
1168 	if (port->type == PORT_HSCIF) {
1169 		if (r < 0 || r > 3)
1170 			return -EINVAL;
1171 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1172 	} else {
1173 		sci->rx_fifo_timeout = r;
1174 		scif_set_rtrg(port, 1);
1175 		if (r > 0)
1176 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1177 	}
1178 
1179 	return count;
1180 }
1181 
1182 static DEVICE_ATTR_RW(rx_fifo_timeout);
1183 
1184 
1185 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1186 static void sci_dma_tx_complete(void *arg)
1187 {
1188 	struct sci_port *s = arg;
1189 	struct uart_port *port = &s->port;
1190 	struct circ_buf *xmit = &port->state->xmit;
1191 	unsigned long flags;
1192 
1193 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1194 
1195 	spin_lock_irqsave(&port->lock, flags);
1196 
1197 	xmit->tail += s->tx_dma_len;
1198 	xmit->tail &= UART_XMIT_SIZE - 1;
1199 
1200 	port->icount.tx += s->tx_dma_len;
1201 
1202 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1203 		uart_write_wakeup(port);
1204 
1205 	if (!uart_circ_empty(xmit)) {
1206 		s->cookie_tx = 0;
1207 		schedule_work(&s->work_tx);
1208 	} else {
1209 		s->cookie_tx = -EINVAL;
1210 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1211 			u16 ctrl = serial_port_in(port, SCSCR);
1212 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1213 		}
1214 	}
1215 
1216 	spin_unlock_irqrestore(&port->lock, flags);
1217 }
1218 
1219 /* Locking: called with port lock held */
1220 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1221 {
1222 	struct uart_port *port = &s->port;
1223 	struct tty_port *tport = &port->state->port;
1224 	int copied;
1225 
1226 	copied = tty_insert_flip_string(tport, buf, count);
1227 	if (copied < count)
1228 		port->icount.buf_overrun++;
1229 
1230 	port->icount.rx += copied;
1231 
1232 	return copied;
1233 }
1234 
1235 static int sci_dma_rx_find_active(struct sci_port *s)
1236 {
1237 	unsigned int i;
1238 
1239 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1240 		if (s->active_rx == s->cookie_rx[i])
1241 			return i;
1242 
1243 	return -1;
1244 }
1245 
1246 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1247 {
1248 	unsigned int i;
1249 
1250 	s->chan_rx = NULL;
1251 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1252 		s->cookie_rx[i] = -EINVAL;
1253 	s->active_rx = 0;
1254 }
1255 
1256 static void sci_dma_rx_release(struct sci_port *s)
1257 {
1258 	struct dma_chan *chan = s->chan_rx_saved;
1259 
1260 	s->chan_rx_saved = NULL;
1261 	sci_dma_rx_chan_invalidate(s);
1262 	dmaengine_terminate_sync(chan);
1263 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1264 			  sg_dma_address(&s->sg_rx[0]));
1265 	dma_release_channel(chan);
1266 }
1267 
1268 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1269 {
1270 	long sec = usec / 1000000;
1271 	long nsec = (usec % 1000000) * 1000;
1272 	ktime_t t = ktime_set(sec, nsec);
1273 
1274 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1275 }
1276 
1277 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1278 {
1279 	struct uart_port *port = &s->port;
1280 	u16 scr;
1281 
1282 	/* Direct new serial port interrupts back to CPU */
1283 	scr = serial_port_in(port, SCSCR);
1284 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1285 		scr &= ~SCSCR_RDRQE;
1286 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1287 	}
1288 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1289 }
1290 
1291 static void sci_dma_rx_complete(void *arg)
1292 {
1293 	struct sci_port *s = arg;
1294 	struct dma_chan *chan = s->chan_rx;
1295 	struct uart_port *port = &s->port;
1296 	struct dma_async_tx_descriptor *desc;
1297 	unsigned long flags;
1298 	int active, count = 0;
1299 
1300 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1301 		s->active_rx);
1302 
1303 	spin_lock_irqsave(&port->lock, flags);
1304 
1305 	active = sci_dma_rx_find_active(s);
1306 	if (active >= 0)
1307 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1308 
1309 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1310 
1311 	if (count)
1312 		tty_flip_buffer_push(&port->state->port);
1313 
1314 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1315 				       DMA_DEV_TO_MEM,
1316 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1317 	if (!desc)
1318 		goto fail;
1319 
1320 	desc->callback = sci_dma_rx_complete;
1321 	desc->callback_param = s;
1322 	s->cookie_rx[active] = dmaengine_submit(desc);
1323 	if (dma_submit_error(s->cookie_rx[active]))
1324 		goto fail;
1325 
1326 	s->active_rx = s->cookie_rx[!active];
1327 
1328 	dma_async_issue_pending(chan);
1329 
1330 	spin_unlock_irqrestore(&port->lock, flags);
1331 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1332 		__func__, s->cookie_rx[active], active, s->active_rx);
1333 	return;
1334 
1335 fail:
1336 	spin_unlock_irqrestore(&port->lock, flags);
1337 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1338 	/* Switch to PIO */
1339 	spin_lock_irqsave(&port->lock, flags);
1340 	dmaengine_terminate_async(chan);
1341 	sci_dma_rx_chan_invalidate(s);
1342 	sci_dma_rx_reenable_irq(s);
1343 	spin_unlock_irqrestore(&port->lock, flags);
1344 }
1345 
1346 static void sci_dma_tx_release(struct sci_port *s)
1347 {
1348 	struct dma_chan *chan = s->chan_tx_saved;
1349 
1350 	cancel_work_sync(&s->work_tx);
1351 	s->chan_tx_saved = s->chan_tx = NULL;
1352 	s->cookie_tx = -EINVAL;
1353 	dmaengine_terminate_sync(chan);
1354 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1355 			 DMA_TO_DEVICE);
1356 	dma_release_channel(chan);
1357 }
1358 
1359 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1360 {
1361 	struct dma_chan *chan = s->chan_rx;
1362 	struct uart_port *port = &s->port;
1363 	unsigned long flags;
1364 	int i;
1365 
1366 	for (i = 0; i < 2; i++) {
1367 		struct scatterlist *sg = &s->sg_rx[i];
1368 		struct dma_async_tx_descriptor *desc;
1369 
1370 		desc = dmaengine_prep_slave_sg(chan,
1371 			sg, 1, DMA_DEV_TO_MEM,
1372 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1373 		if (!desc)
1374 			goto fail;
1375 
1376 		desc->callback = sci_dma_rx_complete;
1377 		desc->callback_param = s;
1378 		s->cookie_rx[i] = dmaengine_submit(desc);
1379 		if (dma_submit_error(s->cookie_rx[i]))
1380 			goto fail;
1381 
1382 	}
1383 
1384 	s->active_rx = s->cookie_rx[0];
1385 
1386 	dma_async_issue_pending(chan);
1387 	return 0;
1388 
1389 fail:
1390 	/* Switch to PIO */
1391 	if (!port_lock_held)
1392 		spin_lock_irqsave(&port->lock, flags);
1393 	if (i)
1394 		dmaengine_terminate_async(chan);
1395 	sci_dma_rx_chan_invalidate(s);
1396 	sci_start_rx(port);
1397 	if (!port_lock_held)
1398 		spin_unlock_irqrestore(&port->lock, flags);
1399 	return -EAGAIN;
1400 }
1401 
1402 static void sci_dma_tx_work_fn(struct work_struct *work)
1403 {
1404 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1405 	struct dma_async_tx_descriptor *desc;
1406 	struct dma_chan *chan = s->chan_tx;
1407 	struct uart_port *port = &s->port;
1408 	struct circ_buf *xmit = &port->state->xmit;
1409 	unsigned long flags;
1410 	dma_addr_t buf;
1411 
1412 	/*
1413 	 * DMA is idle now.
1414 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1415 	 * offsets and lengths. Since it is a circular buffer, we have to
1416 	 * transmit till the end, and then the rest. Take the port lock to get a
1417 	 * consistent xmit buffer state.
1418 	 */
1419 	spin_lock_irq(&port->lock);
1420 	buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1421 	s->tx_dma_len = min_t(unsigned int,
1422 		CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1423 		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1424 	spin_unlock_irq(&port->lock);
1425 
1426 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1427 					   DMA_MEM_TO_DEV,
1428 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1429 	if (!desc) {
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 	spin_lock_irq(&port->lock);
1438 	desc->callback = sci_dma_tx_complete;
1439 	desc->callback_param = s;
1440 	spin_unlock_irq(&port->lock);
1441 	s->cookie_tx = dmaengine_submit(desc);
1442 	if (dma_submit_error(s->cookie_tx)) {
1443 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1444 		goto switch_to_pio;
1445 	}
1446 
1447 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1448 		__func__, xmit->buf, xmit->tail, xmit->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 	if (!port->dev->of_node)
1571 		return;
1572 
1573 	s->cookie_tx = -EINVAL;
1574 
1575 	/*
1576 	 * Don't request a dma channel if no channel was specified
1577 	 * in the device tree.
1578 	 */
1579 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1580 		return;
1581 
1582 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1583 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1584 	if (chan) {
1585 		/* UART circular tx buffer is an aligned page. */
1586 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1587 						port->state->xmit.buf,
1588 						UART_XMIT_SIZE,
1589 						DMA_TO_DEVICE);
1590 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1591 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1592 			dma_release_channel(chan);
1593 		} else {
1594 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1595 				__func__, UART_XMIT_SIZE,
1596 				port->state->xmit.buf, &s->tx_dma_addr);
1597 
1598 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1599 			s->chan_tx_saved = s->chan_tx = chan;
1600 		}
1601 	}
1602 
1603 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1604 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1605 	if (chan) {
1606 		unsigned int i;
1607 		dma_addr_t dma;
1608 		void *buf;
1609 
1610 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1611 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1612 					 &dma, GFP_KERNEL);
1613 		if (!buf) {
1614 			dev_warn(port->dev,
1615 				 "Failed to allocate Rx dma buffer, using PIO\n");
1616 			dma_release_channel(chan);
1617 			return;
1618 		}
1619 
1620 		for (i = 0; i < 2; i++) {
1621 			struct scatterlist *sg = &s->sg_rx[i];
1622 
1623 			sg_init_table(sg, 1);
1624 			s->rx_buf[i] = buf;
1625 			sg_dma_address(sg) = dma;
1626 			sg_dma_len(sg) = s->buf_len_rx;
1627 
1628 			buf += s->buf_len_rx;
1629 			dma += s->buf_len_rx;
1630 		}
1631 
1632 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1633 		s->rx_timer.function = sci_dma_rx_timer_fn;
1634 
1635 		s->chan_rx_saved = s->chan_rx = chan;
1636 
1637 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1638 			sci_dma_rx_submit(s, false);
1639 	}
1640 }
1641 
1642 static void sci_free_dma(struct uart_port *port)
1643 {
1644 	struct sci_port *s = to_sci_port(port);
1645 
1646 	if (s->chan_tx_saved)
1647 		sci_dma_tx_release(s);
1648 	if (s->chan_rx_saved)
1649 		sci_dma_rx_release(s);
1650 }
1651 
1652 static void sci_flush_buffer(struct uart_port *port)
1653 {
1654 	/*
1655 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1656 	 * cleared, so we have to reset tx_dma_len accordingly.
1657 	 */
1658 	to_sci_port(port)->tx_dma_len = 0;
1659 }
1660 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1661 static inline void sci_request_dma(struct uart_port *port)
1662 {
1663 }
1664 
1665 static inline void sci_free_dma(struct uart_port *port)
1666 {
1667 }
1668 
1669 #define sci_flush_buffer	NULL
1670 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1671 
1672 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1673 {
1674 	struct uart_port *port = ptr;
1675 	struct sci_port *s = to_sci_port(port);
1676 
1677 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1678 	if (s->chan_rx) {
1679 		u16 scr = serial_port_in(port, SCSCR);
1680 		u16 ssr = serial_port_in(port, SCxSR);
1681 
1682 		/* Disable future Rx interrupts */
1683 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1684 			disable_irq_nosync(irq);
1685 			scr |= SCSCR_RDRQE;
1686 		} else {
1687 			if (sci_dma_rx_submit(s, false) < 0)
1688 				goto handle_pio;
1689 
1690 			scr &= ~SCSCR_RIE;
1691 		}
1692 		serial_port_out(port, SCSCR, scr);
1693 		/* Clear current interrupt */
1694 		serial_port_out(port, SCxSR,
1695 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1696 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1697 			jiffies, s->rx_timeout);
1698 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1699 
1700 		return IRQ_HANDLED;
1701 	}
1702 
1703 handle_pio:
1704 #endif
1705 
1706 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1707 		if (!scif_rtrg_enabled(port))
1708 			scif_set_rtrg(port, s->rx_trigger);
1709 
1710 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1711 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1712 	}
1713 
1714 	/* I think sci_receive_chars has to be called irrespective
1715 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1716 	 * to be disabled?
1717 	 */
1718 	sci_receive_chars(port);
1719 
1720 	return IRQ_HANDLED;
1721 }
1722 
1723 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1724 {
1725 	struct uart_port *port = ptr;
1726 	unsigned long flags;
1727 
1728 	spin_lock_irqsave(&port->lock, flags);
1729 	sci_transmit_chars(port);
1730 	spin_unlock_irqrestore(&port->lock, flags);
1731 
1732 	return IRQ_HANDLED;
1733 }
1734 
1735 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1736 {
1737 	struct uart_port *port = ptr;
1738 
1739 	/* Handle BREAKs */
1740 	sci_handle_breaks(port);
1741 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1742 
1743 	return IRQ_HANDLED;
1744 }
1745 
1746 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1747 {
1748 	struct uart_port *port = ptr;
1749 	struct sci_port *s = to_sci_port(port);
1750 
1751 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1752 		/* Break and Error interrupts are muxed */
1753 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1754 
1755 		/* Break Interrupt */
1756 		if (ssr_status & SCxSR_BRK(port))
1757 			sci_br_interrupt(irq, ptr);
1758 
1759 		/* Break only? */
1760 		if (!(ssr_status & SCxSR_ERRORS(port)))
1761 			return IRQ_HANDLED;
1762 	}
1763 
1764 	/* Handle errors */
1765 	if (port->type == PORT_SCI) {
1766 		if (sci_handle_errors(port)) {
1767 			/* discard character in rx buffer */
1768 			serial_port_in(port, SCxSR);
1769 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1770 		}
1771 	} else {
1772 		sci_handle_fifo_overrun(port);
1773 		if (!s->chan_rx)
1774 			sci_receive_chars(port);
1775 	}
1776 
1777 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1778 
1779 	/* Kick the transmission */
1780 	if (!s->chan_tx)
1781 		sci_tx_interrupt(irq, ptr);
1782 
1783 	return IRQ_HANDLED;
1784 }
1785 
1786 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1787 {
1788 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1789 	struct uart_port *port = ptr;
1790 	struct sci_port *s = to_sci_port(port);
1791 	irqreturn_t ret = IRQ_NONE;
1792 
1793 	ssr_status = serial_port_in(port, SCxSR);
1794 	scr_status = serial_port_in(port, SCSCR);
1795 	if (s->params->overrun_reg == SCxSR)
1796 		orer_status = ssr_status;
1797 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1798 		orer_status = serial_port_in(port, s->params->overrun_reg);
1799 
1800 	err_enabled = scr_status & port_rx_irq_mask(port);
1801 
1802 	/* Tx Interrupt */
1803 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1804 	    !s->chan_tx)
1805 		ret = sci_tx_interrupt(irq, ptr);
1806 
1807 	/*
1808 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1809 	 * DR flags
1810 	 */
1811 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1812 	    (scr_status & SCSCR_RIE))
1813 		ret = sci_rx_interrupt(irq, ptr);
1814 
1815 	/* Error Interrupt */
1816 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1817 		ret = sci_er_interrupt(irq, ptr);
1818 
1819 	/* Break Interrupt */
1820 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1821 		ret = sci_br_interrupt(irq, ptr);
1822 
1823 	/* Overrun Interrupt */
1824 	if (orer_status & s->params->overrun_mask) {
1825 		sci_handle_fifo_overrun(port);
1826 		ret = IRQ_HANDLED;
1827 	}
1828 
1829 	return ret;
1830 }
1831 
1832 static const struct sci_irq_desc {
1833 	const char	*desc;
1834 	irq_handler_t	handler;
1835 } sci_irq_desc[] = {
1836 	/*
1837 	 * Split out handlers, the default case.
1838 	 */
1839 	[SCIx_ERI_IRQ] = {
1840 		.desc = "rx err",
1841 		.handler = sci_er_interrupt,
1842 	},
1843 
1844 	[SCIx_RXI_IRQ] = {
1845 		.desc = "rx full",
1846 		.handler = sci_rx_interrupt,
1847 	},
1848 
1849 	[SCIx_TXI_IRQ] = {
1850 		.desc = "tx empty",
1851 		.handler = sci_tx_interrupt,
1852 	},
1853 
1854 	[SCIx_BRI_IRQ] = {
1855 		.desc = "break",
1856 		.handler = sci_br_interrupt,
1857 	},
1858 
1859 	[SCIx_DRI_IRQ] = {
1860 		.desc = "rx ready",
1861 		.handler = sci_rx_interrupt,
1862 	},
1863 
1864 	[SCIx_TEI_IRQ] = {
1865 		.desc = "tx end",
1866 		.handler = sci_tx_interrupt,
1867 	},
1868 
1869 	/*
1870 	 * Special muxed handler.
1871 	 */
1872 	[SCIx_MUX_IRQ] = {
1873 		.desc = "mux",
1874 		.handler = sci_mpxed_interrupt,
1875 	},
1876 };
1877 
1878 static int sci_request_irq(struct sci_port *port)
1879 {
1880 	struct uart_port *up = &port->port;
1881 	int i, j, w, ret = 0;
1882 
1883 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1884 		const struct sci_irq_desc *desc;
1885 		int irq;
1886 
1887 		/* Check if already registered (muxed) */
1888 		for (w = 0; w < i; w++)
1889 			if (port->irqs[w] == port->irqs[i])
1890 				w = i + 1;
1891 		if (w > i)
1892 			continue;
1893 
1894 		if (SCIx_IRQ_IS_MUXED(port)) {
1895 			i = SCIx_MUX_IRQ;
1896 			irq = up->irq;
1897 		} else {
1898 			irq = port->irqs[i];
1899 
1900 			/*
1901 			 * Certain port types won't support all of the
1902 			 * available interrupt sources.
1903 			 */
1904 			if (unlikely(irq < 0))
1905 				continue;
1906 		}
1907 
1908 		desc = sci_irq_desc + i;
1909 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1910 					    dev_name(up->dev), desc->desc);
1911 		if (!port->irqstr[j]) {
1912 			ret = -ENOMEM;
1913 			goto out_nomem;
1914 		}
1915 
1916 		ret = request_irq(irq, desc->handler, up->irqflags,
1917 				  port->irqstr[j], port);
1918 		if (unlikely(ret)) {
1919 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1920 			goto out_noirq;
1921 		}
1922 	}
1923 
1924 	return 0;
1925 
1926 out_noirq:
1927 	while (--i >= 0)
1928 		free_irq(port->irqs[i], port);
1929 
1930 out_nomem:
1931 	while (--j >= 0)
1932 		kfree(port->irqstr[j]);
1933 
1934 	return ret;
1935 }
1936 
1937 static void sci_free_irq(struct sci_port *port)
1938 {
1939 	int i, j;
1940 
1941 	/*
1942 	 * Intentionally in reverse order so we iterate over the muxed
1943 	 * IRQ first.
1944 	 */
1945 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1946 		int irq = port->irqs[i];
1947 
1948 		/*
1949 		 * Certain port types won't support all of the available
1950 		 * interrupt sources.
1951 		 */
1952 		if (unlikely(irq < 0))
1953 			continue;
1954 
1955 		/* Check if already freed (irq was muxed) */
1956 		for (j = 0; j < i; j++)
1957 			if (port->irqs[j] == irq)
1958 				j = i + 1;
1959 		if (j > i)
1960 			continue;
1961 
1962 		free_irq(port->irqs[i], port);
1963 		kfree(port->irqstr[i]);
1964 
1965 		if (SCIx_IRQ_IS_MUXED(port)) {
1966 			/* If there's only one IRQ, we're done. */
1967 			return;
1968 		}
1969 	}
1970 }
1971 
1972 static unsigned int sci_tx_empty(struct uart_port *port)
1973 {
1974 	unsigned short status = serial_port_in(port, SCxSR);
1975 	unsigned short in_tx_fifo = sci_txfill(port);
1976 
1977 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1978 }
1979 
1980 static void sci_set_rts(struct uart_port *port, bool state)
1981 {
1982 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1983 		u16 data = serial_port_in(port, SCPDR);
1984 
1985 		/* Active low */
1986 		if (state)
1987 			data &= ~SCPDR_RTSD;
1988 		else
1989 			data |= SCPDR_RTSD;
1990 		serial_port_out(port, SCPDR, data);
1991 
1992 		/* RTS# is output */
1993 		serial_port_out(port, SCPCR,
1994 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
1995 	} else if (sci_getreg(port, SCSPTR)->size) {
1996 		u16 ctrl = serial_port_in(port, SCSPTR);
1997 
1998 		/* Active low */
1999 		if (state)
2000 			ctrl &= ~SCSPTR_RTSDT;
2001 		else
2002 			ctrl |= SCSPTR_RTSDT;
2003 		serial_port_out(port, SCSPTR, ctrl);
2004 	}
2005 }
2006 
2007 static bool sci_get_cts(struct uart_port *port)
2008 {
2009 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2010 		/* Active low */
2011 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2012 	} else if (sci_getreg(port, SCSPTR)->size) {
2013 		/* Active low */
2014 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2015 	}
2016 
2017 	return true;
2018 }
2019 
2020 /*
2021  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2022  * CTS/RTS is supported in hardware by at least one port and controlled
2023  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2024  * handled via the ->init_pins() op, which is a bit of a one-way street,
2025  * lacking any ability to defer pin control -- this will later be
2026  * converted over to the GPIO framework).
2027  *
2028  * Other modes (such as loopback) are supported generically on certain
2029  * port types, but not others. For these it's sufficient to test for the
2030  * existence of the support register and simply ignore the port type.
2031  */
2032 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2033 {
2034 	struct sci_port *s = to_sci_port(port);
2035 
2036 	if (mctrl & TIOCM_LOOP) {
2037 		const struct plat_sci_reg *reg;
2038 
2039 		/*
2040 		 * Standard loopback mode for SCFCR ports.
2041 		 */
2042 		reg = sci_getreg(port, SCFCR);
2043 		if (reg->size)
2044 			serial_port_out(port, SCFCR,
2045 					serial_port_in(port, SCFCR) |
2046 					SCFCR_LOOP);
2047 	}
2048 
2049 	mctrl_gpio_set(s->gpios, mctrl);
2050 
2051 	if (!s->has_rtscts)
2052 		return;
2053 
2054 	if (!(mctrl & TIOCM_RTS)) {
2055 		/* Disable Auto RTS */
2056 		serial_port_out(port, SCFCR,
2057 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2058 
2059 		/* Clear RTS */
2060 		sci_set_rts(port, 0);
2061 	} else if (s->autorts) {
2062 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2063 			/* Enable RTS# pin function */
2064 			serial_port_out(port, SCPCR,
2065 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2066 		}
2067 
2068 		/* Enable Auto RTS */
2069 		serial_port_out(port, SCFCR,
2070 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2071 	} else {
2072 		/* Set RTS */
2073 		sci_set_rts(port, 1);
2074 	}
2075 }
2076 
2077 static unsigned int sci_get_mctrl(struct uart_port *port)
2078 {
2079 	struct sci_port *s = to_sci_port(port);
2080 	struct mctrl_gpios *gpios = s->gpios;
2081 	unsigned int mctrl = 0;
2082 
2083 	mctrl_gpio_get(gpios, &mctrl);
2084 
2085 	/*
2086 	 * CTS/RTS is handled in hardware when supported, while nothing
2087 	 * else is wired up.
2088 	 */
2089 	if (s->autorts) {
2090 		if (sci_get_cts(port))
2091 			mctrl |= TIOCM_CTS;
2092 	} else if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS))) {
2093 		mctrl |= TIOCM_CTS;
2094 	}
2095 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))
2096 		mctrl |= TIOCM_DSR;
2097 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))
2098 		mctrl |= TIOCM_CAR;
2099 
2100 	return mctrl;
2101 }
2102 
2103 static void sci_enable_ms(struct uart_port *port)
2104 {
2105 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2106 }
2107 
2108 static void sci_break_ctl(struct uart_port *port, int break_state)
2109 {
2110 	unsigned short scscr, scsptr;
2111 	unsigned long flags;
2112 
2113 	/* check wheter the port has SCSPTR */
2114 	if (!sci_getreg(port, SCSPTR)->size) {
2115 		/*
2116 		 * Not supported by hardware. Most parts couple break and rx
2117 		 * interrupts together, with break detection always enabled.
2118 		 */
2119 		return;
2120 	}
2121 
2122 	spin_lock_irqsave(&port->lock, flags);
2123 	scsptr = serial_port_in(port, SCSPTR);
2124 	scscr = serial_port_in(port, SCSCR);
2125 
2126 	if (break_state == -1) {
2127 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2128 		scscr &= ~SCSCR_TE;
2129 	} else {
2130 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2131 		scscr |= SCSCR_TE;
2132 	}
2133 
2134 	serial_port_out(port, SCSPTR, scsptr);
2135 	serial_port_out(port, SCSCR, scscr);
2136 	spin_unlock_irqrestore(&port->lock, flags);
2137 }
2138 
2139 static int sci_startup(struct uart_port *port)
2140 {
2141 	struct sci_port *s = to_sci_port(port);
2142 	int ret;
2143 
2144 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2145 
2146 	sci_request_dma(port);
2147 
2148 	ret = sci_request_irq(s);
2149 	if (unlikely(ret < 0)) {
2150 		sci_free_dma(port);
2151 		return ret;
2152 	}
2153 
2154 	return 0;
2155 }
2156 
2157 static void sci_shutdown(struct uart_port *port)
2158 {
2159 	struct sci_port *s = to_sci_port(port);
2160 	unsigned long flags;
2161 	u16 scr;
2162 
2163 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2164 
2165 	s->autorts = false;
2166 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2167 
2168 	spin_lock_irqsave(&port->lock, flags);
2169 	sci_stop_rx(port);
2170 	sci_stop_tx(port);
2171 	/*
2172 	 * Stop RX and TX, disable related interrupts, keep clock source
2173 	 * and HSCIF TOT bits
2174 	 */
2175 	scr = serial_port_in(port, SCSCR);
2176 	serial_port_out(port, SCSCR, scr &
2177 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2178 	spin_unlock_irqrestore(&port->lock, flags);
2179 
2180 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2181 	if (s->chan_rx_saved) {
2182 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2183 			port->line);
2184 		hrtimer_cancel(&s->rx_timer);
2185 	}
2186 #endif
2187 
2188 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2189 		del_timer_sync(&s->rx_fifo_timer);
2190 	sci_free_irq(s);
2191 	sci_free_dma(port);
2192 }
2193 
2194 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2195 			unsigned int *srr)
2196 {
2197 	unsigned long freq = s->clk_rates[SCI_SCK];
2198 	int err, min_err = INT_MAX;
2199 	unsigned int sr;
2200 
2201 	if (s->port.type != PORT_HSCIF)
2202 		freq *= 2;
2203 
2204 	for_each_sr(sr, s) {
2205 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2206 		if (abs(err) >= abs(min_err))
2207 			continue;
2208 
2209 		min_err = err;
2210 		*srr = sr - 1;
2211 
2212 		if (!err)
2213 			break;
2214 	}
2215 
2216 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2217 		*srr + 1);
2218 	return min_err;
2219 }
2220 
2221 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2222 			unsigned long freq, unsigned int *dlr,
2223 			unsigned int *srr)
2224 {
2225 	int err, min_err = INT_MAX;
2226 	unsigned int sr, dl;
2227 
2228 	if (s->port.type != PORT_HSCIF)
2229 		freq *= 2;
2230 
2231 	for_each_sr(sr, s) {
2232 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2233 		dl = clamp(dl, 1U, 65535U);
2234 
2235 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2236 		if (abs(err) >= abs(min_err))
2237 			continue;
2238 
2239 		min_err = err;
2240 		*dlr = dl;
2241 		*srr = sr - 1;
2242 
2243 		if (!err)
2244 			break;
2245 	}
2246 
2247 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2248 		min_err, *dlr, *srr + 1);
2249 	return min_err;
2250 }
2251 
2252 /* calculate sample rate, BRR, and clock select */
2253 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2254 			  unsigned int *brr, unsigned int *srr,
2255 			  unsigned int *cks)
2256 {
2257 	unsigned long freq = s->clk_rates[SCI_FCK];
2258 	unsigned int sr, br, prediv, scrate, c;
2259 	int err, min_err = INT_MAX;
2260 
2261 	if (s->port.type != PORT_HSCIF)
2262 		freq *= 2;
2263 
2264 	/*
2265 	 * Find the combination of sample rate and clock select with the
2266 	 * smallest deviation from the desired baud rate.
2267 	 * Prefer high sample rates to maximise the receive margin.
2268 	 *
2269 	 * M: Receive margin (%)
2270 	 * N: Ratio of bit rate to clock (N = sampling rate)
2271 	 * D: Clock duty (D = 0 to 1.0)
2272 	 * L: Frame length (L = 9 to 12)
2273 	 * F: Absolute value of clock frequency deviation
2274 	 *
2275 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2276 	 *      (|D - 0.5| / N * (1 + F))|
2277 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2278 	 */
2279 	for_each_sr(sr, s) {
2280 		for (c = 0; c <= 3; c++) {
2281 			/* integerized formulas from HSCIF documentation */
2282 			prediv = sr * (1 << (2 * c + 1));
2283 
2284 			/*
2285 			 * We need to calculate:
2286 			 *
2287 			 *     br = freq / (prediv * bps) clamped to [1..256]
2288 			 *     err = freq / (br * prediv) - bps
2289 			 *
2290 			 * Watch out for overflow when calculating the desired
2291 			 * sampling clock rate!
2292 			 */
2293 			if (bps > UINT_MAX / prediv)
2294 				break;
2295 
2296 			scrate = prediv * bps;
2297 			br = DIV_ROUND_CLOSEST(freq, scrate);
2298 			br = clamp(br, 1U, 256U);
2299 
2300 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2301 			if (abs(err) >= abs(min_err))
2302 				continue;
2303 
2304 			min_err = err;
2305 			*brr = br - 1;
2306 			*srr = sr - 1;
2307 			*cks = c;
2308 
2309 			if (!err)
2310 				goto found;
2311 		}
2312 	}
2313 
2314 found:
2315 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2316 		min_err, *brr, *srr + 1, *cks);
2317 	return min_err;
2318 }
2319 
2320 static void sci_reset(struct uart_port *port)
2321 {
2322 	const struct plat_sci_reg *reg;
2323 	unsigned int status;
2324 	struct sci_port *s = to_sci_port(port);
2325 
2326 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2327 
2328 	reg = sci_getreg(port, SCFCR);
2329 	if (reg->size)
2330 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2331 
2332 	sci_clear_SCxSR(port,
2333 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2334 			SCxSR_BREAK_CLEAR(port));
2335 	if (sci_getreg(port, SCLSR)->size) {
2336 		status = serial_port_in(port, SCLSR);
2337 		status &= ~(SCLSR_TO | SCLSR_ORER);
2338 		serial_port_out(port, SCLSR, status);
2339 	}
2340 
2341 	if (s->rx_trigger > 1) {
2342 		if (s->rx_fifo_timeout) {
2343 			scif_set_rtrg(port, 1);
2344 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2345 		} else {
2346 			if (port->type == PORT_SCIFA ||
2347 			    port->type == PORT_SCIFB)
2348 				scif_set_rtrg(port, 1);
2349 			else
2350 				scif_set_rtrg(port, s->rx_trigger);
2351 		}
2352 	}
2353 }
2354 
2355 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2356 			    struct ktermios *old)
2357 {
2358 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2359 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2360 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2361 	struct sci_port *s = to_sci_port(port);
2362 	const struct plat_sci_reg *reg;
2363 	int min_err = INT_MAX, err;
2364 	unsigned long max_freq = 0;
2365 	int best_clk = -1;
2366 	unsigned long flags;
2367 
2368 	if ((termios->c_cflag & CSIZE) == CS7)
2369 		smr_val |= SCSMR_CHR;
2370 	if (termios->c_cflag & PARENB)
2371 		smr_val |= SCSMR_PE;
2372 	if (termios->c_cflag & PARODD)
2373 		smr_val |= SCSMR_PE | SCSMR_ODD;
2374 	if (termios->c_cflag & CSTOPB)
2375 		smr_val |= SCSMR_STOP;
2376 
2377 	/*
2378 	 * earlyprintk comes here early on with port->uartclk set to zero.
2379 	 * the clock framework is not up and running at this point so here
2380 	 * we assume that 115200 is the maximum baud rate. please note that
2381 	 * the baud rate is not programmed during earlyprintk - it is assumed
2382 	 * that the previous boot loader has enabled required clocks and
2383 	 * setup the baud rate generator hardware for us already.
2384 	 */
2385 	if (!port->uartclk) {
2386 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2387 		goto done;
2388 	}
2389 
2390 	for (i = 0; i < SCI_NUM_CLKS; i++)
2391 		max_freq = max(max_freq, s->clk_rates[i]);
2392 
2393 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2394 	if (!baud)
2395 		goto done;
2396 
2397 	/*
2398 	 * There can be multiple sources for the sampling clock.  Find the one
2399 	 * that gives us the smallest deviation from the desired baud rate.
2400 	 */
2401 
2402 	/* Optional Undivided External Clock */
2403 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2404 	    port->type != PORT_SCIFB) {
2405 		err = sci_sck_calc(s, baud, &srr1);
2406 		if (abs(err) < abs(min_err)) {
2407 			best_clk = SCI_SCK;
2408 			scr_val = SCSCR_CKE1;
2409 			sccks = SCCKS_CKS;
2410 			min_err = err;
2411 			srr = srr1;
2412 			if (!err)
2413 				goto done;
2414 		}
2415 	}
2416 
2417 	/* Optional BRG Frequency Divided External Clock */
2418 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2419 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2420 				   &srr1);
2421 		if (abs(err) < abs(min_err)) {
2422 			best_clk = SCI_SCIF_CLK;
2423 			scr_val = SCSCR_CKE1;
2424 			sccks = 0;
2425 			min_err = err;
2426 			dl = dl1;
2427 			srr = srr1;
2428 			if (!err)
2429 				goto done;
2430 		}
2431 	}
2432 
2433 	/* Optional BRG Frequency Divided Internal Clock */
2434 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2435 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2436 				   &srr1);
2437 		if (abs(err) < abs(min_err)) {
2438 			best_clk = SCI_BRG_INT;
2439 			scr_val = SCSCR_CKE1;
2440 			sccks = SCCKS_XIN;
2441 			min_err = err;
2442 			dl = dl1;
2443 			srr = srr1;
2444 			if (!min_err)
2445 				goto done;
2446 		}
2447 	}
2448 
2449 	/* Divided Functional Clock using standard Bit Rate Register */
2450 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2451 	if (abs(err) < abs(min_err)) {
2452 		best_clk = SCI_FCK;
2453 		scr_val = 0;
2454 		min_err = err;
2455 		brr = brr1;
2456 		srr = srr1;
2457 		cks = cks1;
2458 	}
2459 
2460 done:
2461 	if (best_clk >= 0)
2462 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2463 			s->clks[best_clk], baud, min_err);
2464 
2465 	sci_port_enable(s);
2466 
2467 	/*
2468 	 * Program the optional External Baud Rate Generator (BRG) first.
2469 	 * It controls the mux to select (H)SCK or frequency divided clock.
2470 	 */
2471 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2472 		serial_port_out(port, SCDL, dl);
2473 		serial_port_out(port, SCCKS, sccks);
2474 	}
2475 
2476 	spin_lock_irqsave(&port->lock, flags);
2477 
2478 	sci_reset(port);
2479 
2480 	uart_update_timeout(port, termios->c_cflag, baud);
2481 
2482 	/* byte size and parity */
2483 	switch (termios->c_cflag & CSIZE) {
2484 	case CS5:
2485 		bits = 7;
2486 		break;
2487 	case CS6:
2488 		bits = 8;
2489 		break;
2490 	case CS7:
2491 		bits = 9;
2492 		break;
2493 	default:
2494 		bits = 10;
2495 		break;
2496 	}
2497 
2498 	if (termios->c_cflag & CSTOPB)
2499 		bits++;
2500 	if (termios->c_cflag & PARENB)
2501 		bits++;
2502 
2503 	if (best_clk >= 0) {
2504 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2505 			switch (srr + 1) {
2506 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2507 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2508 			case 11: smr_val |= SCSMR_SRC_11; break;
2509 			case 13: smr_val |= SCSMR_SRC_13; break;
2510 			case 16: smr_val |= SCSMR_SRC_16; break;
2511 			case 17: smr_val |= SCSMR_SRC_17; break;
2512 			case 19: smr_val |= SCSMR_SRC_19; break;
2513 			case 27: smr_val |= SCSMR_SRC_27; break;
2514 			}
2515 		smr_val |= cks;
2516 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2517 		serial_port_out(port, SCSMR, smr_val);
2518 		serial_port_out(port, SCBRR, brr);
2519 		if (sci_getreg(port, HSSRR)->size) {
2520 			unsigned int hssrr = srr | HSCIF_SRE;
2521 			/* Calculate deviation from intended rate at the
2522 			 * center of the last stop bit in sampling clocks.
2523 			 */
2524 			int last_stop = bits * 2 - 1;
2525 			int deviation = min_err * srr * last_stop / 2 / baud;
2526 
2527 			if (abs(deviation) >= 2) {
2528 				/* At least two sampling clocks off at the
2529 				 * last stop bit; we can increase the error
2530 				 * margin by shifting the sampling point.
2531 				 */
2532 				int shift = min(-8, max(7, deviation / 2));
2533 
2534 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2535 					 HSCIF_SRHP_MASK;
2536 				hssrr |= HSCIF_SRDE;
2537 			}
2538 			serial_port_out(port, HSSRR, hssrr);
2539 		}
2540 
2541 		/* Wait one bit interval */
2542 		udelay((1000000 + (baud - 1)) / baud);
2543 	} else {
2544 		/* Don't touch the bit rate configuration */
2545 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2546 		smr_val |= serial_port_in(port, SCSMR) &
2547 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2548 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2549 		serial_port_out(port, SCSMR, smr_val);
2550 	}
2551 
2552 	sci_init_pins(port, termios->c_cflag);
2553 
2554 	port->status &= ~UPSTAT_AUTOCTS;
2555 	s->autorts = false;
2556 	reg = sci_getreg(port, SCFCR);
2557 	if (reg->size) {
2558 		unsigned short ctrl = serial_port_in(port, SCFCR);
2559 
2560 		if ((port->flags & UPF_HARD_FLOW) &&
2561 		    (termios->c_cflag & CRTSCTS)) {
2562 			/* There is no CTS interrupt to restart the hardware */
2563 			port->status |= UPSTAT_AUTOCTS;
2564 			/* MCE is enabled when RTS is raised */
2565 			s->autorts = true;
2566 		}
2567 
2568 		/*
2569 		 * As we've done a sci_reset() above, ensure we don't
2570 		 * interfere with the FIFOs while toggling MCE. As the
2571 		 * reset values could still be set, simply mask them out.
2572 		 */
2573 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2574 
2575 		serial_port_out(port, SCFCR, ctrl);
2576 	}
2577 	if (port->flags & UPF_HARD_FLOW) {
2578 		/* Refresh (Auto) RTS */
2579 		sci_set_mctrl(port, port->mctrl);
2580 	}
2581 
2582 	scr_val |= SCSCR_RE | SCSCR_TE |
2583 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2584 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2585 	if ((srr + 1 == 5) &&
2586 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2587 		/*
2588 		 * In asynchronous mode, when the sampling rate is 1/5, first
2589 		 * received data may become invalid on some SCIFA and SCIFB.
2590 		 * To avoid this problem wait more than 1 serial data time (1
2591 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2592 		 */
2593 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2594 	}
2595 
2596 	/*
2597 	 * Calculate delay for 2 DMA buffers (4 FIFO).
2598 	 * See serial_core.c::uart_update_timeout().
2599 	 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2600 	 * function calculates 1 jiffie for the data plus 5 jiffies for the
2601 	 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2602 	 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2603 	 * value obtained by this formula is too small. Therefore, if the value
2604 	 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2605 	 */
2606 	s->rx_frame = (10000 * bits) / (baud / 100);
2607 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2608 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2609 	if (s->rx_timeout < 20)
2610 		s->rx_timeout = 20;
2611 #endif
2612 
2613 	if ((termios->c_cflag & CREAD) != 0)
2614 		sci_start_rx(port);
2615 
2616 	spin_unlock_irqrestore(&port->lock, flags);
2617 
2618 	sci_port_disable(s);
2619 
2620 	if (UART_ENABLE_MS(port, termios->c_cflag))
2621 		sci_enable_ms(port);
2622 }
2623 
2624 static void sci_pm(struct uart_port *port, unsigned int state,
2625 		   unsigned int oldstate)
2626 {
2627 	struct sci_port *sci_port = to_sci_port(port);
2628 
2629 	switch (state) {
2630 	case UART_PM_STATE_OFF:
2631 		sci_port_disable(sci_port);
2632 		break;
2633 	default:
2634 		sci_port_enable(sci_port);
2635 		break;
2636 	}
2637 }
2638 
2639 static const char *sci_type(struct uart_port *port)
2640 {
2641 	switch (port->type) {
2642 	case PORT_IRDA:
2643 		return "irda";
2644 	case PORT_SCI:
2645 		return "sci";
2646 	case PORT_SCIF:
2647 		return "scif";
2648 	case PORT_SCIFA:
2649 		return "scifa";
2650 	case PORT_SCIFB:
2651 		return "scifb";
2652 	case PORT_HSCIF:
2653 		return "hscif";
2654 	}
2655 
2656 	return NULL;
2657 }
2658 
2659 static int sci_remap_port(struct uart_port *port)
2660 {
2661 	struct sci_port *sport = to_sci_port(port);
2662 
2663 	/*
2664 	 * Nothing to do if there's already an established membase.
2665 	 */
2666 	if (port->membase)
2667 		return 0;
2668 
2669 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2670 		port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2671 		if (unlikely(!port->membase)) {
2672 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2673 			return -ENXIO;
2674 		}
2675 	} else {
2676 		/*
2677 		 * For the simple (and majority of) cases where we don't
2678 		 * need to do any remapping, just cast the cookie
2679 		 * directly.
2680 		 */
2681 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2682 	}
2683 
2684 	return 0;
2685 }
2686 
2687 static void sci_release_port(struct uart_port *port)
2688 {
2689 	struct sci_port *sport = to_sci_port(port);
2690 
2691 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2692 		iounmap(port->membase);
2693 		port->membase = NULL;
2694 	}
2695 
2696 	release_mem_region(port->mapbase, sport->reg_size);
2697 }
2698 
2699 static int sci_request_port(struct uart_port *port)
2700 {
2701 	struct resource *res;
2702 	struct sci_port *sport = to_sci_port(port);
2703 	int ret;
2704 
2705 	res = request_mem_region(port->mapbase, sport->reg_size,
2706 				 dev_name(port->dev));
2707 	if (unlikely(res == NULL)) {
2708 		dev_err(port->dev, "request_mem_region failed.");
2709 		return -EBUSY;
2710 	}
2711 
2712 	ret = sci_remap_port(port);
2713 	if (unlikely(ret != 0)) {
2714 		release_resource(res);
2715 		return ret;
2716 	}
2717 
2718 	return 0;
2719 }
2720 
2721 static void sci_config_port(struct uart_port *port, int flags)
2722 {
2723 	if (flags & UART_CONFIG_TYPE) {
2724 		struct sci_port *sport = to_sci_port(port);
2725 
2726 		port->type = sport->cfg->type;
2727 		sci_request_port(port);
2728 	}
2729 }
2730 
2731 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2732 {
2733 	if (ser->baud_base < 2400)
2734 		/* No paper tape reader for Mitch.. */
2735 		return -EINVAL;
2736 
2737 	return 0;
2738 }
2739 
2740 static const struct uart_ops sci_uart_ops = {
2741 	.tx_empty	= sci_tx_empty,
2742 	.set_mctrl	= sci_set_mctrl,
2743 	.get_mctrl	= sci_get_mctrl,
2744 	.start_tx	= sci_start_tx,
2745 	.stop_tx	= sci_stop_tx,
2746 	.stop_rx	= sci_stop_rx,
2747 	.enable_ms	= sci_enable_ms,
2748 	.break_ctl	= sci_break_ctl,
2749 	.startup	= sci_startup,
2750 	.shutdown	= sci_shutdown,
2751 	.flush_buffer	= sci_flush_buffer,
2752 	.set_termios	= sci_set_termios,
2753 	.pm		= sci_pm,
2754 	.type		= sci_type,
2755 	.release_port	= sci_release_port,
2756 	.request_port	= sci_request_port,
2757 	.config_port	= sci_config_port,
2758 	.verify_port	= sci_verify_port,
2759 #ifdef CONFIG_CONSOLE_POLL
2760 	.poll_get_char	= sci_poll_get_char,
2761 	.poll_put_char	= sci_poll_put_char,
2762 #endif
2763 };
2764 
2765 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2766 {
2767 	const char *clk_names[] = {
2768 		[SCI_FCK] = "fck",
2769 		[SCI_SCK] = "sck",
2770 		[SCI_BRG_INT] = "brg_int",
2771 		[SCI_SCIF_CLK] = "scif_clk",
2772 	};
2773 	struct clk *clk;
2774 	unsigned int i;
2775 
2776 	if (sci_port->cfg->type == PORT_HSCIF)
2777 		clk_names[SCI_SCK] = "hsck";
2778 
2779 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2780 		clk = devm_clk_get(dev, clk_names[i]);
2781 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2782 			return -EPROBE_DEFER;
2783 
2784 		if (IS_ERR(clk) && i == SCI_FCK) {
2785 			/*
2786 			 * "fck" used to be called "sci_ick", and we need to
2787 			 * maintain DT backward compatibility.
2788 			 */
2789 			clk = devm_clk_get(dev, "sci_ick");
2790 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2791 				return -EPROBE_DEFER;
2792 
2793 			if (!IS_ERR(clk))
2794 				goto found;
2795 
2796 			/*
2797 			 * Not all SH platforms declare a clock lookup entry
2798 			 * for SCI devices, in which case we need to get the
2799 			 * global "peripheral_clk" clock.
2800 			 */
2801 			clk = devm_clk_get(dev, "peripheral_clk");
2802 			if (!IS_ERR(clk))
2803 				goto found;
2804 
2805 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2806 				PTR_ERR(clk));
2807 			return PTR_ERR(clk);
2808 		}
2809 
2810 found:
2811 		if (IS_ERR(clk))
2812 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2813 				PTR_ERR(clk));
2814 		else
2815 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2816 				clk, clk_get_rate(clk));
2817 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2818 	}
2819 	return 0;
2820 }
2821 
2822 static const struct sci_port_params *
2823 sci_probe_regmap(const struct plat_sci_port *cfg)
2824 {
2825 	unsigned int regtype;
2826 
2827 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2828 		return &sci_port_params[cfg->regtype];
2829 
2830 	switch (cfg->type) {
2831 	case PORT_SCI:
2832 		regtype = SCIx_SCI_REGTYPE;
2833 		break;
2834 	case PORT_IRDA:
2835 		regtype = SCIx_IRDA_REGTYPE;
2836 		break;
2837 	case PORT_SCIFA:
2838 		regtype = SCIx_SCIFA_REGTYPE;
2839 		break;
2840 	case PORT_SCIFB:
2841 		regtype = SCIx_SCIFB_REGTYPE;
2842 		break;
2843 	case PORT_SCIF:
2844 		/*
2845 		 * The SH-4 is a bit of a misnomer here, although that's
2846 		 * where this particular port layout originated. This
2847 		 * configuration (or some slight variation thereof)
2848 		 * remains the dominant model for all SCIFs.
2849 		 */
2850 		regtype = SCIx_SH4_SCIF_REGTYPE;
2851 		break;
2852 	case PORT_HSCIF:
2853 		regtype = SCIx_HSCIF_REGTYPE;
2854 		break;
2855 	default:
2856 		pr_err("Can't probe register map for given port\n");
2857 		return NULL;
2858 	}
2859 
2860 	return &sci_port_params[regtype];
2861 }
2862 
2863 static int sci_init_single(struct platform_device *dev,
2864 			   struct sci_port *sci_port, unsigned int index,
2865 			   const struct plat_sci_port *p, bool early)
2866 {
2867 	struct uart_port *port = &sci_port->port;
2868 	const struct resource *res;
2869 	unsigned int i;
2870 	int ret;
2871 
2872 	sci_port->cfg	= p;
2873 
2874 	port->ops	= &sci_uart_ops;
2875 	port->iotype	= UPIO_MEM;
2876 	port->line	= index;
2877 
2878 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2879 	if (res == NULL)
2880 		return -ENOMEM;
2881 
2882 	port->mapbase = res->start;
2883 	sci_port->reg_size = resource_size(res);
2884 
2885 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2886 		sci_port->irqs[i] = platform_get_irq(dev, i);
2887 
2888 	/* The SCI generates several interrupts. They can be muxed together or
2889 	 * connected to different interrupt lines. In the muxed case only one
2890 	 * interrupt resource is specified as there is only one interrupt ID.
2891 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2892 	 * from the SCI, however those signals might have their own individual
2893 	 * interrupt ID numbers, or muxed together with another interrupt.
2894 	 */
2895 	if (sci_port->irqs[0] < 0)
2896 		return -ENXIO;
2897 
2898 	if (sci_port->irqs[1] < 0)
2899 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2900 			sci_port->irqs[i] = sci_port->irqs[0];
2901 
2902 	sci_port->params = sci_probe_regmap(p);
2903 	if (unlikely(sci_port->params == NULL))
2904 		return -EINVAL;
2905 
2906 	switch (p->type) {
2907 	case PORT_SCIFB:
2908 		sci_port->rx_trigger = 48;
2909 		break;
2910 	case PORT_HSCIF:
2911 		sci_port->rx_trigger = 64;
2912 		break;
2913 	case PORT_SCIFA:
2914 		sci_port->rx_trigger = 32;
2915 		break;
2916 	case PORT_SCIF:
2917 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2918 			/* RX triggering not implemented for this IP */
2919 			sci_port->rx_trigger = 1;
2920 		else
2921 			sci_port->rx_trigger = 8;
2922 		break;
2923 	default:
2924 		sci_port->rx_trigger = 1;
2925 		break;
2926 	}
2927 
2928 	sci_port->rx_fifo_timeout = 0;
2929 	sci_port->hscif_tot = 0;
2930 
2931 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2932 	 * match the SoC datasheet, this should be investigated. Let platform
2933 	 * data override the sampling rate for now.
2934 	 */
2935 	sci_port->sampling_rate_mask = p->sampling_rate
2936 				     ? SCI_SR(p->sampling_rate)
2937 				     : sci_port->params->sampling_rate_mask;
2938 
2939 	if (!early) {
2940 		ret = sci_init_clocks(sci_port, &dev->dev);
2941 		if (ret < 0)
2942 			return ret;
2943 
2944 		port->dev = &dev->dev;
2945 
2946 		pm_runtime_enable(&dev->dev);
2947 	}
2948 
2949 	port->type		= p->type;
2950 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2951 	port->fifosize		= sci_port->params->fifosize;
2952 
2953 	if (port->type == PORT_SCI) {
2954 		if (sci_port->reg_size >= 0x20)
2955 			port->regshift = 2;
2956 		else
2957 			port->regshift = 1;
2958 	}
2959 
2960 	/*
2961 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2962 	 * for the multi-IRQ ports, which is where we are primarily
2963 	 * concerned with the shutdown path synchronization.
2964 	 *
2965 	 * For the muxed case there's nothing more to do.
2966 	 */
2967 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2968 	port->irqflags		= 0;
2969 
2970 	port->serial_in		= sci_serial_in;
2971 	port->serial_out	= sci_serial_out;
2972 
2973 	return 0;
2974 }
2975 
2976 static void sci_cleanup_single(struct sci_port *port)
2977 {
2978 	pm_runtime_disable(port->port.dev);
2979 }
2980 
2981 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2982     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2983 static void serial_console_putchar(struct uart_port *port, int ch)
2984 {
2985 	sci_poll_put_char(port, ch);
2986 }
2987 
2988 /*
2989  *	Print a string to the serial port trying not to disturb
2990  *	any possible real use of the port...
2991  */
2992 static void serial_console_write(struct console *co, const char *s,
2993 				 unsigned count)
2994 {
2995 	struct sci_port *sci_port = &sci_ports[co->index];
2996 	struct uart_port *port = &sci_port->port;
2997 	unsigned short bits, ctrl, ctrl_temp;
2998 	unsigned long flags;
2999 	int locked = 1;
3000 
3001 #if defined(SUPPORT_SYSRQ)
3002 	if (port->sysrq)
3003 		locked = 0;
3004 	else
3005 #endif
3006 	if (oops_in_progress)
3007 		locked = spin_trylock_irqsave(&port->lock, flags);
3008 	else
3009 		spin_lock_irqsave(&port->lock, flags);
3010 
3011 	/* first save SCSCR then disable interrupts, keep clock source */
3012 	ctrl = serial_port_in(port, SCSCR);
3013 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3014 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3015 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3016 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3017 
3018 	uart_console_write(port, s, count, serial_console_putchar);
3019 
3020 	/* wait until fifo is empty and last bit has been transmitted */
3021 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3022 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3023 		cpu_relax();
3024 
3025 	/* restore the SCSCR */
3026 	serial_port_out(port, SCSCR, ctrl);
3027 
3028 	if (locked)
3029 		spin_unlock_irqrestore(&port->lock, flags);
3030 }
3031 
3032 static int serial_console_setup(struct console *co, char *options)
3033 {
3034 	struct sci_port *sci_port;
3035 	struct uart_port *port;
3036 	int baud = 115200;
3037 	int bits = 8;
3038 	int parity = 'n';
3039 	int flow = 'n';
3040 	int ret;
3041 
3042 	/*
3043 	 * Refuse to handle any bogus ports.
3044 	 */
3045 	if (co->index < 0 || co->index >= SCI_NPORTS)
3046 		return -ENODEV;
3047 
3048 	sci_port = &sci_ports[co->index];
3049 	port = &sci_port->port;
3050 
3051 	/*
3052 	 * Refuse to handle uninitialized ports.
3053 	 */
3054 	if (!port->ops)
3055 		return -ENODEV;
3056 
3057 	ret = sci_remap_port(port);
3058 	if (unlikely(ret != 0))
3059 		return ret;
3060 
3061 	if (options)
3062 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3063 
3064 	return uart_set_options(port, co, baud, parity, bits, flow);
3065 }
3066 
3067 static struct console serial_console = {
3068 	.name		= "ttySC",
3069 	.device		= uart_console_device,
3070 	.write		= serial_console_write,
3071 	.setup		= serial_console_setup,
3072 	.flags		= CON_PRINTBUFFER,
3073 	.index		= -1,
3074 	.data		= &sci_uart_driver,
3075 };
3076 
3077 static struct console early_serial_console = {
3078 	.name           = "early_ttySC",
3079 	.write          = serial_console_write,
3080 	.flags          = CON_PRINTBUFFER,
3081 	.index		= -1,
3082 };
3083 
3084 static char early_serial_buf[32];
3085 
3086 static int sci_probe_earlyprintk(struct platform_device *pdev)
3087 {
3088 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3089 
3090 	if (early_serial_console.data)
3091 		return -EEXIST;
3092 
3093 	early_serial_console.index = pdev->id;
3094 
3095 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3096 
3097 	serial_console_setup(&early_serial_console, early_serial_buf);
3098 
3099 	if (!strstr(early_serial_buf, "keep"))
3100 		early_serial_console.flags |= CON_BOOT;
3101 
3102 	register_console(&early_serial_console);
3103 	return 0;
3104 }
3105 
3106 #define SCI_CONSOLE	(&serial_console)
3107 
3108 #else
3109 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3110 {
3111 	return -EINVAL;
3112 }
3113 
3114 #define SCI_CONSOLE	NULL
3115 
3116 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3117 
3118 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3119 
3120 static DEFINE_MUTEX(sci_uart_registration_lock);
3121 static struct uart_driver sci_uart_driver = {
3122 	.owner		= THIS_MODULE,
3123 	.driver_name	= "sci",
3124 	.dev_name	= "ttySC",
3125 	.major		= SCI_MAJOR,
3126 	.minor		= SCI_MINOR_START,
3127 	.nr		= SCI_NPORTS,
3128 	.cons		= SCI_CONSOLE,
3129 };
3130 
3131 static int sci_remove(struct platform_device *dev)
3132 {
3133 	struct sci_port *port = platform_get_drvdata(dev);
3134 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3135 
3136 	sci_ports_in_use &= ~BIT(port->port.line);
3137 	uart_remove_one_port(&sci_uart_driver, &port->port);
3138 
3139 	sci_cleanup_single(port);
3140 
3141 	if (port->port.fifosize > 1) {
3142 		sysfs_remove_file(&dev->dev.kobj,
3143 				  &dev_attr_rx_fifo_trigger.attr);
3144 	}
3145 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF) {
3146 		sysfs_remove_file(&dev->dev.kobj,
3147 				  &dev_attr_rx_fifo_timeout.attr);
3148 	}
3149 
3150 	return 0;
3151 }
3152 
3153 
3154 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3155 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3156 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3157 
3158 static const struct of_device_id of_sci_match[] = {
3159 	/* SoC-specific types */
3160 	{
3161 		.compatible = "renesas,scif-r7s72100",
3162 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3163 	},
3164 	{
3165 		.compatible = "renesas,scif-r7s9210",
3166 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3167 	},
3168 	/* Family-specific types */
3169 	{
3170 		.compatible = "renesas,rcar-gen1-scif",
3171 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3172 	}, {
3173 		.compatible = "renesas,rcar-gen2-scif",
3174 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3175 	}, {
3176 		.compatible = "renesas,rcar-gen3-scif",
3177 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3178 	},
3179 	/* Generic types */
3180 	{
3181 		.compatible = "renesas,scif",
3182 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3183 	}, {
3184 		.compatible = "renesas,scifa",
3185 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3186 	}, {
3187 		.compatible = "renesas,scifb",
3188 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3189 	}, {
3190 		.compatible = "renesas,hscif",
3191 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3192 	}, {
3193 		.compatible = "renesas,sci",
3194 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3195 	}, {
3196 		/* Terminator */
3197 	},
3198 };
3199 MODULE_DEVICE_TABLE(of, of_sci_match);
3200 
3201 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3202 					  unsigned int *dev_id)
3203 {
3204 	struct device_node *np = pdev->dev.of_node;
3205 	struct plat_sci_port *p;
3206 	struct sci_port *sp;
3207 	const void *data;
3208 	int id;
3209 
3210 	if (!IS_ENABLED(CONFIG_OF) || !np)
3211 		return NULL;
3212 
3213 	data = of_device_get_match_data(&pdev->dev);
3214 
3215 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3216 	if (!p)
3217 		return NULL;
3218 
3219 	/* Get the line number from the aliases node. */
3220 	id = of_alias_get_id(np, "serial");
3221 	if (id < 0 && ~sci_ports_in_use)
3222 		id = ffz(sci_ports_in_use);
3223 	if (id < 0) {
3224 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3225 		return NULL;
3226 	}
3227 	if (id >= ARRAY_SIZE(sci_ports)) {
3228 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3229 		return NULL;
3230 	}
3231 
3232 	sp = &sci_ports[id];
3233 	*dev_id = id;
3234 
3235 	p->type = SCI_OF_TYPE(data);
3236 	p->regtype = SCI_OF_REGTYPE(data);
3237 
3238 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3239 
3240 	return p;
3241 }
3242 
3243 static int sci_probe_single(struct platform_device *dev,
3244 				      unsigned int index,
3245 				      struct plat_sci_port *p,
3246 				      struct sci_port *sciport)
3247 {
3248 	int ret;
3249 
3250 	/* Sanity check */
3251 	if (unlikely(index >= SCI_NPORTS)) {
3252 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3253 			   index+1, SCI_NPORTS);
3254 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3255 		return -EINVAL;
3256 	}
3257 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3258 	if (sci_ports_in_use & BIT(index))
3259 		return -EBUSY;
3260 
3261 	mutex_lock(&sci_uart_registration_lock);
3262 	if (!sci_uart_driver.state) {
3263 		ret = uart_register_driver(&sci_uart_driver);
3264 		if (ret) {
3265 			mutex_unlock(&sci_uart_registration_lock);
3266 			return ret;
3267 		}
3268 	}
3269 	mutex_unlock(&sci_uart_registration_lock);
3270 
3271 	ret = sci_init_single(dev, sciport, index, p, false);
3272 	if (ret)
3273 		return ret;
3274 
3275 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3276 	if (IS_ERR(sciport->gpios) && PTR_ERR(sciport->gpios) != -ENOSYS)
3277 		return PTR_ERR(sciport->gpios);
3278 
3279 	if (sciport->has_rtscts) {
3280 		if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3281 							UART_GPIO_CTS)) ||
3282 		    !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3283 							UART_GPIO_RTS))) {
3284 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3285 			return -EINVAL;
3286 		}
3287 		sciport->port.flags |= UPF_HARD_FLOW;
3288 	}
3289 
3290 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3291 	if (ret) {
3292 		sci_cleanup_single(sciport);
3293 		return ret;
3294 	}
3295 
3296 	return 0;
3297 }
3298 
3299 static int sci_probe(struct platform_device *dev)
3300 {
3301 	struct plat_sci_port *p;
3302 	struct sci_port *sp;
3303 	unsigned int dev_id;
3304 	int ret;
3305 
3306 	/*
3307 	 * If we've come here via earlyprintk initialization, head off to
3308 	 * the special early probe. We don't have sufficient device state
3309 	 * to make it beyond this yet.
3310 	 */
3311 	if (is_early_platform_device(dev))
3312 		return sci_probe_earlyprintk(dev);
3313 
3314 	if (dev->dev.of_node) {
3315 		p = sci_parse_dt(dev, &dev_id);
3316 		if (p == NULL)
3317 			return -EINVAL;
3318 	} else {
3319 		p = dev->dev.platform_data;
3320 		if (p == NULL) {
3321 			dev_err(&dev->dev, "no platform data supplied\n");
3322 			return -EINVAL;
3323 		}
3324 
3325 		dev_id = dev->id;
3326 	}
3327 
3328 	sp = &sci_ports[dev_id];
3329 	platform_set_drvdata(dev, sp);
3330 
3331 	ret = sci_probe_single(dev, dev_id, p, sp);
3332 	if (ret)
3333 		return ret;
3334 
3335 	if (sp->port.fifosize > 1) {
3336 		ret = sysfs_create_file(&dev->dev.kobj,
3337 				&dev_attr_rx_fifo_trigger.attr);
3338 		if (ret)
3339 			return ret;
3340 	}
3341 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3342 	    sp->port.type == PORT_HSCIF) {
3343 		ret = sysfs_create_file(&dev->dev.kobj,
3344 				&dev_attr_rx_fifo_timeout.attr);
3345 		if (ret) {
3346 			if (sp->port.fifosize > 1) {
3347 				sysfs_remove_file(&dev->dev.kobj,
3348 					&dev_attr_rx_fifo_trigger.attr);
3349 			}
3350 			return ret;
3351 		}
3352 	}
3353 
3354 #ifdef CONFIG_SH_STANDARD_BIOS
3355 	sh_bios_gdb_detach();
3356 #endif
3357 
3358 	sci_ports_in_use |= BIT(dev_id);
3359 	return 0;
3360 }
3361 
3362 static __maybe_unused int sci_suspend(struct device *dev)
3363 {
3364 	struct sci_port *sport = dev_get_drvdata(dev);
3365 
3366 	if (sport)
3367 		uart_suspend_port(&sci_uart_driver, &sport->port);
3368 
3369 	return 0;
3370 }
3371 
3372 static __maybe_unused int sci_resume(struct device *dev)
3373 {
3374 	struct sci_port *sport = dev_get_drvdata(dev);
3375 
3376 	if (sport)
3377 		uart_resume_port(&sci_uart_driver, &sport->port);
3378 
3379 	return 0;
3380 }
3381 
3382 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3383 
3384 static struct platform_driver sci_driver = {
3385 	.probe		= sci_probe,
3386 	.remove		= sci_remove,
3387 	.driver		= {
3388 		.name	= "sh-sci",
3389 		.pm	= &sci_dev_pm_ops,
3390 		.of_match_table = of_match_ptr(of_sci_match),
3391 	},
3392 };
3393 
3394 static int __init sci_init(void)
3395 {
3396 	pr_info("%s\n", banner);
3397 
3398 	return platform_driver_register(&sci_driver);
3399 }
3400 
3401 static void __exit sci_exit(void)
3402 {
3403 	platform_driver_unregister(&sci_driver);
3404 
3405 	if (sci_uart_driver.state)
3406 		uart_unregister_driver(&sci_uart_driver);
3407 }
3408 
3409 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3410 early_platform_init_buffer("earlyprintk", &sci_driver,
3411 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3412 #endif
3413 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3414 static struct plat_sci_port port_cfg __initdata;
3415 
3416 static int __init early_console_setup(struct earlycon_device *device,
3417 				      int type)
3418 {
3419 	if (!device->port.membase)
3420 		return -ENODEV;
3421 
3422 	device->port.serial_in = sci_serial_in;
3423 	device->port.serial_out	= sci_serial_out;
3424 	device->port.type = type;
3425 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3426 	port_cfg.type = type;
3427 	sci_ports[0].cfg = &port_cfg;
3428 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3429 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3430 	sci_serial_out(&sci_ports[0].port, SCSCR,
3431 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3432 
3433 	device->con->write = serial_console_write;
3434 	return 0;
3435 }
3436 static int __init sci_early_console_setup(struct earlycon_device *device,
3437 					  const char *opt)
3438 {
3439 	return early_console_setup(device, PORT_SCI);
3440 }
3441 static int __init scif_early_console_setup(struct earlycon_device *device,
3442 					  const char *opt)
3443 {
3444 	return early_console_setup(device, PORT_SCIF);
3445 }
3446 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3447 					  const char *opt)
3448 {
3449 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3450 	return early_console_setup(device, PORT_SCIF);
3451 }
3452 static int __init scifa_early_console_setup(struct earlycon_device *device,
3453 					  const char *opt)
3454 {
3455 	return early_console_setup(device, PORT_SCIFA);
3456 }
3457 static int __init scifb_early_console_setup(struct earlycon_device *device,
3458 					  const char *opt)
3459 {
3460 	return early_console_setup(device, PORT_SCIFB);
3461 }
3462 static int __init hscif_early_console_setup(struct earlycon_device *device,
3463 					  const char *opt)
3464 {
3465 	return early_console_setup(device, PORT_HSCIF);
3466 }
3467 
3468 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3469 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3470 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3471 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3472 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3473 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3474 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3475 
3476 module_init(sci_init);
3477 module_exit(sci_exit);
3478 
3479 MODULE_LICENSE("GPL");
3480 MODULE_ALIAS("platform:sh-sci");
3481 MODULE_AUTHOR("Paul Mundt");
3482 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3483