xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision 2fa5ebe3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #undef DEBUG
19 
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/minmax.h>
35 #include <linux/module.h>
36 #include <linux/mm.h>
37 #include <linux/of.h>
38 #include <linux/of_device.h>
39 #include <linux/platform_device.h>
40 #include <linux/pm_runtime.h>
41 #include <linux/reset.h>
42 #include <linux/scatterlist.h>
43 #include <linux/serial.h>
44 #include <linux/serial_sci.h>
45 #include <linux/sh_dma.h>
46 #include <linux/slab.h>
47 #include <linux/string.h>
48 #include <linux/sysrq.h>
49 #include <linux/timer.h>
50 #include <linux/tty.h>
51 #include <linux/tty_flip.h>
52 
53 #ifdef CONFIG_SUPERH
54 #include <asm/sh_bios.h>
55 #include <asm/platform_early.h>
56 #endif
57 
58 #include "serial_mctrl_gpio.h"
59 #include "sh-sci.h"
60 
61 /* Offsets into the sci_port->irqs array */
62 enum {
63 	SCIx_ERI_IRQ,
64 	SCIx_RXI_IRQ,
65 	SCIx_TXI_IRQ,
66 	SCIx_BRI_IRQ,
67 	SCIx_DRI_IRQ,
68 	SCIx_TEI_IRQ,
69 	SCIx_NR_IRQS,
70 
71 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
72 };
73 
74 #define SCIx_IRQ_IS_MUXED(port)			\
75 	((port)->irqs[SCIx_ERI_IRQ] ==	\
76 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
77 	((port)->irqs[SCIx_ERI_IRQ] &&	\
78 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
79 
80 enum SCI_CLKS {
81 	SCI_FCK,		/* Functional Clock */
82 	SCI_SCK,		/* Optional External Clock */
83 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
84 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
85 	SCI_NUM_CLKS
86 };
87 
88 /* Bit x set means sampling rate x + 1 is supported */
89 #define SCI_SR(x)		BIT((x) - 1)
90 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
91 
92 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
93 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
94 				SCI_SR(19) | SCI_SR(27)
95 
96 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
97 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
98 
99 /* Iterate over all supported sampling rates, from high to low */
100 #define for_each_sr(_sr, _port)						\
101 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
102 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
103 
104 struct plat_sci_reg {
105 	u8 offset, size;
106 };
107 
108 struct sci_port_params {
109 	const struct plat_sci_reg regs[SCIx_NR_REGS];
110 	unsigned int fifosize;
111 	unsigned int overrun_reg;
112 	unsigned int overrun_mask;
113 	unsigned int sampling_rate_mask;
114 	unsigned int error_mask;
115 	unsigned int error_clear;
116 };
117 
118 struct sci_port {
119 	struct uart_port	port;
120 
121 	/* Platform configuration */
122 	const struct sci_port_params *params;
123 	const struct plat_sci_port *cfg;
124 	unsigned int		sampling_rate_mask;
125 	resource_size_t		reg_size;
126 	struct mctrl_gpios	*gpios;
127 
128 	/* Clocks */
129 	struct clk		*clks[SCI_NUM_CLKS];
130 	unsigned long		clk_rates[SCI_NUM_CLKS];
131 
132 	int			irqs[SCIx_NR_IRQS];
133 	char			*irqstr[SCIx_NR_IRQS];
134 
135 	struct dma_chan			*chan_tx;
136 	struct dma_chan			*chan_rx;
137 
138 #ifdef CONFIG_SERIAL_SH_SCI_DMA
139 	struct dma_chan			*chan_tx_saved;
140 	struct dma_chan			*chan_rx_saved;
141 	dma_cookie_t			cookie_tx;
142 	dma_cookie_t			cookie_rx[2];
143 	dma_cookie_t			active_rx;
144 	dma_addr_t			tx_dma_addr;
145 	unsigned int			tx_dma_len;
146 	struct scatterlist		sg_rx[2];
147 	void				*rx_buf[2];
148 	size_t				buf_len_rx;
149 	struct work_struct		work_tx;
150 	struct hrtimer			rx_timer;
151 	unsigned int			rx_timeout;	/* microseconds */
152 #endif
153 	unsigned int			rx_frame;
154 	int				rx_trigger;
155 	struct timer_list		rx_fifo_timer;
156 	int				rx_fifo_timeout;
157 	u16				hscif_tot;
158 
159 	bool has_rtscts;
160 	bool autorts;
161 };
162 
163 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
164 
165 static struct sci_port sci_ports[SCI_NPORTS];
166 static unsigned long sci_ports_in_use;
167 static struct uart_driver sci_uart_driver;
168 
169 static inline struct sci_port *
170 to_sci_port(struct uart_port *uart)
171 {
172 	return container_of(uart, struct sci_port, port);
173 }
174 
175 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
176 	/*
177 	 * Common SCI definitions, dependent on the port's regshift
178 	 * value.
179 	 */
180 	[SCIx_SCI_REGTYPE] = {
181 		.regs = {
182 			[SCSMR]		= { 0x00,  8 },
183 			[SCBRR]		= { 0x01,  8 },
184 			[SCSCR]		= { 0x02,  8 },
185 			[SCxTDR]	= { 0x03,  8 },
186 			[SCxSR]		= { 0x04,  8 },
187 			[SCxRDR]	= { 0x05,  8 },
188 		},
189 		.fifosize = 1,
190 		.overrun_reg = SCxSR,
191 		.overrun_mask = SCI_ORER,
192 		.sampling_rate_mask = SCI_SR(32),
193 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
194 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
195 	},
196 
197 	/*
198 	 * Common definitions for legacy IrDA ports.
199 	 */
200 	[SCIx_IRDA_REGTYPE] = {
201 		.regs = {
202 			[SCSMR]		= { 0x00,  8 },
203 			[SCBRR]		= { 0x02,  8 },
204 			[SCSCR]		= { 0x04,  8 },
205 			[SCxTDR]	= { 0x06,  8 },
206 			[SCxSR]		= { 0x08, 16 },
207 			[SCxRDR]	= { 0x0a,  8 },
208 			[SCFCR]		= { 0x0c,  8 },
209 			[SCFDR]		= { 0x0e, 16 },
210 		},
211 		.fifosize = 1,
212 		.overrun_reg = SCxSR,
213 		.overrun_mask = SCI_ORER,
214 		.sampling_rate_mask = SCI_SR(32),
215 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
216 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
217 	},
218 
219 	/*
220 	 * Common SCIFA definitions.
221 	 */
222 	[SCIx_SCIFA_REGTYPE] = {
223 		.regs = {
224 			[SCSMR]		= { 0x00, 16 },
225 			[SCBRR]		= { 0x04,  8 },
226 			[SCSCR]		= { 0x08, 16 },
227 			[SCxTDR]	= { 0x20,  8 },
228 			[SCxSR]		= { 0x14, 16 },
229 			[SCxRDR]	= { 0x24,  8 },
230 			[SCFCR]		= { 0x18, 16 },
231 			[SCFDR]		= { 0x1c, 16 },
232 			[SCPCR]		= { 0x30, 16 },
233 			[SCPDR]		= { 0x34, 16 },
234 		},
235 		.fifosize = 64,
236 		.overrun_reg = SCxSR,
237 		.overrun_mask = SCIFA_ORER,
238 		.sampling_rate_mask = SCI_SR_SCIFAB,
239 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
240 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
241 	},
242 
243 	/*
244 	 * Common SCIFB definitions.
245 	 */
246 	[SCIx_SCIFB_REGTYPE] = {
247 		.regs = {
248 			[SCSMR]		= { 0x00, 16 },
249 			[SCBRR]		= { 0x04,  8 },
250 			[SCSCR]		= { 0x08, 16 },
251 			[SCxTDR]	= { 0x40,  8 },
252 			[SCxSR]		= { 0x14, 16 },
253 			[SCxRDR]	= { 0x60,  8 },
254 			[SCFCR]		= { 0x18, 16 },
255 			[SCTFDR]	= { 0x38, 16 },
256 			[SCRFDR]	= { 0x3c, 16 },
257 			[SCPCR]		= { 0x30, 16 },
258 			[SCPDR]		= { 0x34, 16 },
259 		},
260 		.fifosize = 256,
261 		.overrun_reg = SCxSR,
262 		.overrun_mask = SCIFA_ORER,
263 		.sampling_rate_mask = SCI_SR_SCIFAB,
264 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
265 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
266 	},
267 
268 	/*
269 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
270 	 * count registers.
271 	 */
272 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
273 		.regs = {
274 			[SCSMR]		= { 0x00, 16 },
275 			[SCBRR]		= { 0x04,  8 },
276 			[SCSCR]		= { 0x08, 16 },
277 			[SCxTDR]	= { 0x0c,  8 },
278 			[SCxSR]		= { 0x10, 16 },
279 			[SCxRDR]	= { 0x14,  8 },
280 			[SCFCR]		= { 0x18, 16 },
281 			[SCFDR]		= { 0x1c, 16 },
282 			[SCSPTR]	= { 0x20, 16 },
283 			[SCLSR]		= { 0x24, 16 },
284 		},
285 		.fifosize = 16,
286 		.overrun_reg = SCLSR,
287 		.overrun_mask = SCLSR_ORER,
288 		.sampling_rate_mask = SCI_SR(32),
289 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
290 		.error_clear = SCIF_ERROR_CLEAR,
291 	},
292 
293 	/*
294 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
295 	 * It looks like a normal SCIF with FIFO data, but with a
296 	 * compressed address space. Also, the break out of interrupts
297 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
298 	 */
299 	[SCIx_RZ_SCIFA_REGTYPE] = {
300 		.regs = {
301 			[SCSMR]		= { 0x00, 16 },
302 			[SCBRR]		= { 0x02,  8 },
303 			[SCSCR]		= { 0x04, 16 },
304 			[SCxTDR]	= { 0x06,  8 },
305 			[SCxSR]		= { 0x08, 16 },
306 			[SCxRDR]	= { 0x0A,  8 },
307 			[SCFCR]		= { 0x0C, 16 },
308 			[SCFDR]		= { 0x0E, 16 },
309 			[SCSPTR]	= { 0x10, 16 },
310 			[SCLSR]		= { 0x12, 16 },
311 			[SEMR]		= { 0x14, 8 },
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 #ifdef CONFIG_SERIAL_SH_SCI_DMA
618 	if (to_sci_port(port)->chan_tx &&
619 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
620 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
621 		to_sci_port(port)->cookie_tx = -EINVAL;
622 	}
623 #endif
624 }
625 
626 static void sci_start_rx(struct uart_port *port)
627 {
628 	unsigned short ctrl;
629 
630 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
631 
632 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
633 		ctrl &= ~SCSCR_RDRQE;
634 
635 	serial_port_out(port, SCSCR, ctrl);
636 }
637 
638 static void sci_stop_rx(struct uart_port *port)
639 {
640 	unsigned short ctrl;
641 
642 	ctrl = serial_port_in(port, SCSCR);
643 
644 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
645 		ctrl &= ~SCSCR_RDRQE;
646 
647 	ctrl &= ~port_rx_irq_mask(port);
648 
649 	serial_port_out(port, SCSCR, ctrl);
650 }
651 
652 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
653 {
654 	if (port->type == PORT_SCI) {
655 		/* Just store the mask */
656 		serial_port_out(port, SCxSR, mask);
657 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
658 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
659 		/* Only clear the status bits we want to clear */
660 		serial_port_out(port, SCxSR,
661 				serial_port_in(port, SCxSR) & mask);
662 	} else {
663 		/* Store the mask, clear parity/framing errors */
664 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
665 	}
666 }
667 
668 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
669     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
670 
671 #ifdef CONFIG_CONSOLE_POLL
672 static int sci_poll_get_char(struct uart_port *port)
673 {
674 	unsigned short status;
675 	int c;
676 
677 	do {
678 		status = serial_port_in(port, SCxSR);
679 		if (status & SCxSR_ERRORS(port)) {
680 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
681 			continue;
682 		}
683 		break;
684 	} while (1);
685 
686 	if (!(status & SCxSR_RDxF(port)))
687 		return NO_POLL_CHAR;
688 
689 	c = serial_port_in(port, SCxRDR);
690 
691 	/* Dummy read */
692 	serial_port_in(port, SCxSR);
693 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
694 
695 	return c;
696 }
697 #endif
698 
699 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
700 {
701 	unsigned short status;
702 
703 	do {
704 		status = serial_port_in(port, SCxSR);
705 	} while (!(status & SCxSR_TDxE(port)));
706 
707 	serial_port_out(port, SCxTDR, c);
708 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
709 }
710 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
711 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
712 
713 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
714 {
715 	struct sci_port *s = to_sci_port(port);
716 
717 	/*
718 	 * Use port-specific handler if provided.
719 	 */
720 	if (s->cfg->ops && s->cfg->ops->init_pins) {
721 		s->cfg->ops->init_pins(port, cflag);
722 		return;
723 	}
724 
725 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
726 		u16 data = serial_port_in(port, SCPDR);
727 		u16 ctrl = serial_port_in(port, SCPCR);
728 
729 		/* Enable RXD and TXD pin functions */
730 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
731 		if (to_sci_port(port)->has_rtscts) {
732 			/* RTS# is output, active low, unless autorts */
733 			if (!(port->mctrl & TIOCM_RTS)) {
734 				ctrl |= SCPCR_RTSC;
735 				data |= SCPDR_RTSD;
736 			} else if (!s->autorts) {
737 				ctrl |= SCPCR_RTSC;
738 				data &= ~SCPDR_RTSD;
739 			} else {
740 				/* Enable RTS# pin function */
741 				ctrl &= ~SCPCR_RTSC;
742 			}
743 			/* Enable CTS# pin function */
744 			ctrl &= ~SCPCR_CTSC;
745 		}
746 		serial_port_out(port, SCPDR, data);
747 		serial_port_out(port, SCPCR, ctrl);
748 	} else if (sci_getreg(port, SCSPTR)->size) {
749 		u16 status = serial_port_in(port, SCSPTR);
750 
751 		/* RTS# is always output; and active low, unless autorts */
752 		status |= SCSPTR_RTSIO;
753 		if (!(port->mctrl & TIOCM_RTS))
754 			status |= SCSPTR_RTSDT;
755 		else if (!s->autorts)
756 			status &= ~SCSPTR_RTSDT;
757 		/* CTS# and SCK are inputs */
758 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
759 		serial_port_out(port, SCSPTR, status);
760 	}
761 }
762 
763 static int sci_txfill(struct uart_port *port)
764 {
765 	struct sci_port *s = to_sci_port(port);
766 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
767 	const struct plat_sci_reg *reg;
768 
769 	reg = sci_getreg(port, SCTFDR);
770 	if (reg->size)
771 		return serial_port_in(port, SCTFDR) & fifo_mask;
772 
773 	reg = sci_getreg(port, SCFDR);
774 	if (reg->size)
775 		return serial_port_in(port, SCFDR) >> 8;
776 
777 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
778 }
779 
780 static int sci_txroom(struct uart_port *port)
781 {
782 	return port->fifosize - sci_txfill(port);
783 }
784 
785 static int sci_rxfill(struct uart_port *port)
786 {
787 	struct sci_port *s = to_sci_port(port);
788 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
789 	const struct plat_sci_reg *reg;
790 
791 	reg = sci_getreg(port, SCRFDR);
792 	if (reg->size)
793 		return serial_port_in(port, SCRFDR) & fifo_mask;
794 
795 	reg = sci_getreg(port, SCFDR);
796 	if (reg->size)
797 		return serial_port_in(port, SCFDR) & fifo_mask;
798 
799 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
800 }
801 
802 /* ********************************************************************** *
803  *                   the interrupt related routines                       *
804  * ********************************************************************** */
805 
806 static void sci_transmit_chars(struct uart_port *port)
807 {
808 	struct circ_buf *xmit = &port->state->xmit;
809 	unsigned int stopped = uart_tx_stopped(port);
810 	unsigned short status;
811 	unsigned short ctrl;
812 	int count;
813 
814 	status = serial_port_in(port, SCxSR);
815 	if (!(status & SCxSR_TDxE(port))) {
816 		ctrl = serial_port_in(port, SCSCR);
817 		if (uart_circ_empty(xmit))
818 			ctrl &= ~SCSCR_TIE;
819 		else
820 			ctrl |= SCSCR_TIE;
821 		serial_port_out(port, SCSCR, ctrl);
822 		return;
823 	}
824 
825 	count = sci_txroom(port);
826 
827 	do {
828 		unsigned char c;
829 
830 		if (port->x_char) {
831 			c = port->x_char;
832 			port->x_char = 0;
833 		} else if (!uart_circ_empty(xmit) && !stopped) {
834 			c = xmit->buf[xmit->tail];
835 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
836 		} else {
837 			break;
838 		}
839 
840 		serial_port_out(port, SCxTDR, c);
841 
842 		port->icount.tx++;
843 	} while (--count > 0);
844 
845 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
846 
847 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
848 		uart_write_wakeup(port);
849 	if (uart_circ_empty(xmit))
850 		sci_stop_tx(port);
851 
852 }
853 
854 static void sci_receive_chars(struct uart_port *port)
855 {
856 	struct tty_port *tport = &port->state->port;
857 	int i, count, copied = 0;
858 	unsigned short status;
859 	unsigned char flag;
860 
861 	status = serial_port_in(port, SCxSR);
862 	if (!(status & SCxSR_RDxF(port)))
863 		return;
864 
865 	while (1) {
866 		/* Don't copy more bytes than there is room for in the buffer */
867 		count = tty_buffer_request_room(tport, sci_rxfill(port));
868 
869 		/* If for any reason we can't copy more data, we're done! */
870 		if (count == 0)
871 			break;
872 
873 		if (port->type == PORT_SCI) {
874 			char c = serial_port_in(port, SCxRDR);
875 			if (uart_handle_sysrq_char(port, c))
876 				count = 0;
877 			else
878 				tty_insert_flip_char(tport, c, TTY_NORMAL);
879 		} else {
880 			for (i = 0; i < count; i++) {
881 				char c;
882 
883 				if (port->type == PORT_SCIF ||
884 				    port->type == PORT_HSCIF) {
885 					status = serial_port_in(port, SCxSR);
886 					c = serial_port_in(port, SCxRDR);
887 				} else {
888 					c = serial_port_in(port, SCxRDR);
889 					status = serial_port_in(port, SCxSR);
890 				}
891 				if (uart_handle_sysrq_char(port, c)) {
892 					count--; i--;
893 					continue;
894 				}
895 
896 				/* Store data and status */
897 				if (status & SCxSR_FER(port)) {
898 					flag = TTY_FRAME;
899 					port->icount.frame++;
900 				} else if (status & SCxSR_PER(port)) {
901 					flag = TTY_PARITY;
902 					port->icount.parity++;
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 
944 	if (status & SCxSR_FER(port)) {
945 		/* frame error */
946 		port->icount.frame++;
947 
948 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
949 			copied++;
950 	}
951 
952 	if (status & SCxSR_PER(port)) {
953 		/* parity error */
954 		port->icount.parity++;
955 
956 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
957 			copied++;
958 	}
959 
960 	if (copied)
961 		tty_flip_buffer_push(tport);
962 
963 	return copied;
964 }
965 
966 static int sci_handle_fifo_overrun(struct uart_port *port)
967 {
968 	struct tty_port *tport = &port->state->port;
969 	struct sci_port *s = to_sci_port(port);
970 	const struct plat_sci_reg *reg;
971 	int copied = 0;
972 	u16 status;
973 
974 	reg = sci_getreg(port, s->params->overrun_reg);
975 	if (!reg->size)
976 		return 0;
977 
978 	status = serial_port_in(port, s->params->overrun_reg);
979 	if (status & s->params->overrun_mask) {
980 		status &= ~s->params->overrun_mask;
981 		serial_port_out(port, s->params->overrun_reg, status);
982 
983 		port->icount.overrun++;
984 
985 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
986 		tty_flip_buffer_push(tport);
987 		copied++;
988 	}
989 
990 	return copied;
991 }
992 
993 static int sci_handle_breaks(struct uart_port *port)
994 {
995 	int copied = 0;
996 	unsigned short status = serial_port_in(port, SCxSR);
997 	struct tty_port *tport = &port->state->port;
998 
999 	if (uart_handle_break(port))
1000 		return 0;
1001 
1002 	if (status & SCxSR_BRK(port)) {
1003 		port->icount.brk++;
1004 
1005 		/* Notify of BREAK */
1006 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1007 			copied++;
1008 	}
1009 
1010 	if (copied)
1011 		tty_flip_buffer_push(tport);
1012 
1013 	copied += sci_handle_fifo_overrun(port);
1014 
1015 	return copied;
1016 }
1017 
1018 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1019 {
1020 	unsigned int bits;
1021 
1022 	if (rx_trig >= port->fifosize)
1023 		rx_trig = port->fifosize - 1;
1024 	if (rx_trig < 1)
1025 		rx_trig = 1;
1026 
1027 	/* HSCIF can be set to an arbitrary level. */
1028 	if (sci_getreg(port, HSRTRGR)->size) {
1029 		serial_port_out(port, HSRTRGR, rx_trig);
1030 		return rx_trig;
1031 	}
1032 
1033 	switch (port->type) {
1034 	case PORT_SCIF:
1035 		if (rx_trig < 4) {
1036 			bits = 0;
1037 			rx_trig = 1;
1038 		} else if (rx_trig < 8) {
1039 			bits = SCFCR_RTRG0;
1040 			rx_trig = 4;
1041 		} else if (rx_trig < 14) {
1042 			bits = SCFCR_RTRG1;
1043 			rx_trig = 8;
1044 		} else {
1045 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1046 			rx_trig = 14;
1047 		}
1048 		break;
1049 	case PORT_SCIFA:
1050 	case PORT_SCIFB:
1051 		if (rx_trig < 16) {
1052 			bits = 0;
1053 			rx_trig = 1;
1054 		} else if (rx_trig < 32) {
1055 			bits = SCFCR_RTRG0;
1056 			rx_trig = 16;
1057 		} else if (rx_trig < 48) {
1058 			bits = SCFCR_RTRG1;
1059 			rx_trig = 32;
1060 		} else {
1061 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1062 			rx_trig = 48;
1063 		}
1064 		break;
1065 	default:
1066 		WARN(1, "unknown FIFO configuration");
1067 		return 1;
1068 	}
1069 
1070 	serial_port_out(port, SCFCR,
1071 		(serial_port_in(port, SCFCR) &
1072 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1073 
1074 	return rx_trig;
1075 }
1076 
1077 static int scif_rtrg_enabled(struct uart_port *port)
1078 {
1079 	if (sci_getreg(port, HSRTRGR)->size)
1080 		return serial_port_in(port, HSRTRGR) != 0;
1081 	else
1082 		return (serial_port_in(port, SCFCR) &
1083 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1084 }
1085 
1086 static void rx_fifo_timer_fn(struct timer_list *t)
1087 {
1088 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1089 	struct uart_port *port = &s->port;
1090 
1091 	dev_dbg(port->dev, "Rx timed out\n");
1092 	scif_set_rtrg(port, 1);
1093 }
1094 
1095 static ssize_t rx_fifo_trigger_show(struct device *dev,
1096 				    struct device_attribute *attr, char *buf)
1097 {
1098 	struct uart_port *port = dev_get_drvdata(dev);
1099 	struct sci_port *sci = to_sci_port(port);
1100 
1101 	return sprintf(buf, "%d\n", sci->rx_trigger);
1102 }
1103 
1104 static ssize_t rx_fifo_trigger_store(struct device *dev,
1105 				     struct device_attribute *attr,
1106 				     const char *buf, size_t count)
1107 {
1108 	struct uart_port *port = dev_get_drvdata(dev);
1109 	struct sci_port *sci = to_sci_port(port);
1110 	int ret;
1111 	long r;
1112 
1113 	ret = kstrtol(buf, 0, &r);
1114 	if (ret)
1115 		return ret;
1116 
1117 	sci->rx_trigger = scif_set_rtrg(port, r);
1118 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1119 		scif_set_rtrg(port, 1);
1120 
1121 	return count;
1122 }
1123 
1124 static DEVICE_ATTR_RW(rx_fifo_trigger);
1125 
1126 static ssize_t rx_fifo_timeout_show(struct device *dev,
1127 			       struct device_attribute *attr,
1128 			       char *buf)
1129 {
1130 	struct uart_port *port = dev_get_drvdata(dev);
1131 	struct sci_port *sci = to_sci_port(port);
1132 	int v;
1133 
1134 	if (port->type == PORT_HSCIF)
1135 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1136 	else
1137 		v = sci->rx_fifo_timeout;
1138 
1139 	return sprintf(buf, "%d\n", v);
1140 }
1141 
1142 static ssize_t rx_fifo_timeout_store(struct device *dev,
1143 				struct device_attribute *attr,
1144 				const char *buf,
1145 				size_t count)
1146 {
1147 	struct uart_port *port = dev_get_drvdata(dev);
1148 	struct sci_port *sci = to_sci_port(port);
1149 	int ret;
1150 	long r;
1151 
1152 	ret = kstrtol(buf, 0, &r);
1153 	if (ret)
1154 		return ret;
1155 
1156 	if (port->type == PORT_HSCIF) {
1157 		if (r < 0 || r > 3)
1158 			return -EINVAL;
1159 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1160 	} else {
1161 		sci->rx_fifo_timeout = r;
1162 		scif_set_rtrg(port, 1);
1163 		if (r > 0)
1164 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1165 	}
1166 
1167 	return count;
1168 }
1169 
1170 static DEVICE_ATTR_RW(rx_fifo_timeout);
1171 
1172 
1173 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1174 static void sci_dma_tx_complete(void *arg)
1175 {
1176 	struct sci_port *s = arg;
1177 	struct uart_port *port = &s->port;
1178 	struct circ_buf *xmit = &port->state->xmit;
1179 	unsigned long flags;
1180 
1181 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1182 
1183 	spin_lock_irqsave(&port->lock, flags);
1184 
1185 	uart_xmit_advance(port, s->tx_dma_len);
1186 
1187 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1188 		uart_write_wakeup(port);
1189 
1190 	if (!uart_circ_empty(xmit)) {
1191 		s->cookie_tx = 0;
1192 		schedule_work(&s->work_tx);
1193 	} else {
1194 		s->cookie_tx = -EINVAL;
1195 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1196 			u16 ctrl = serial_port_in(port, SCSCR);
1197 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1198 		}
1199 	}
1200 
1201 	spin_unlock_irqrestore(&port->lock, flags);
1202 }
1203 
1204 /* Locking: called with port lock held */
1205 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1206 {
1207 	struct uart_port *port = &s->port;
1208 	struct tty_port *tport = &port->state->port;
1209 	int copied;
1210 
1211 	copied = tty_insert_flip_string(tport, buf, count);
1212 	if (copied < count)
1213 		port->icount.buf_overrun++;
1214 
1215 	port->icount.rx += copied;
1216 
1217 	return copied;
1218 }
1219 
1220 static int sci_dma_rx_find_active(struct sci_port *s)
1221 {
1222 	unsigned int i;
1223 
1224 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1225 		if (s->active_rx == s->cookie_rx[i])
1226 			return i;
1227 
1228 	return -1;
1229 }
1230 
1231 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1232 {
1233 	unsigned int i;
1234 
1235 	s->chan_rx = NULL;
1236 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1237 		s->cookie_rx[i] = -EINVAL;
1238 	s->active_rx = 0;
1239 }
1240 
1241 static void sci_dma_rx_release(struct sci_port *s)
1242 {
1243 	struct dma_chan *chan = s->chan_rx_saved;
1244 
1245 	s->chan_rx_saved = NULL;
1246 	sci_dma_rx_chan_invalidate(s);
1247 	dmaengine_terminate_sync(chan);
1248 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1249 			  sg_dma_address(&s->sg_rx[0]));
1250 	dma_release_channel(chan);
1251 }
1252 
1253 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1254 {
1255 	long sec = usec / 1000000;
1256 	long nsec = (usec % 1000000) * 1000;
1257 	ktime_t t = ktime_set(sec, nsec);
1258 
1259 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1260 }
1261 
1262 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1263 {
1264 	struct uart_port *port = &s->port;
1265 	u16 scr;
1266 
1267 	/* Direct new serial port interrupts back to CPU */
1268 	scr = serial_port_in(port, SCSCR);
1269 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1270 		scr &= ~SCSCR_RDRQE;
1271 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1272 	}
1273 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1274 }
1275 
1276 static void sci_dma_rx_complete(void *arg)
1277 {
1278 	struct sci_port *s = arg;
1279 	struct dma_chan *chan = s->chan_rx;
1280 	struct uart_port *port = &s->port;
1281 	struct dma_async_tx_descriptor *desc;
1282 	unsigned long flags;
1283 	int active, count = 0;
1284 
1285 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1286 		s->active_rx);
1287 
1288 	spin_lock_irqsave(&port->lock, flags);
1289 
1290 	active = sci_dma_rx_find_active(s);
1291 	if (active >= 0)
1292 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1293 
1294 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1295 
1296 	if (count)
1297 		tty_flip_buffer_push(&port->state->port);
1298 
1299 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1300 				       DMA_DEV_TO_MEM,
1301 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1302 	if (!desc)
1303 		goto fail;
1304 
1305 	desc->callback = sci_dma_rx_complete;
1306 	desc->callback_param = s;
1307 	s->cookie_rx[active] = dmaengine_submit(desc);
1308 	if (dma_submit_error(s->cookie_rx[active]))
1309 		goto fail;
1310 
1311 	s->active_rx = s->cookie_rx[!active];
1312 
1313 	dma_async_issue_pending(chan);
1314 
1315 	spin_unlock_irqrestore(&port->lock, flags);
1316 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1317 		__func__, s->cookie_rx[active], active, s->active_rx);
1318 	return;
1319 
1320 fail:
1321 	spin_unlock_irqrestore(&port->lock, flags);
1322 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1323 	/* Switch to PIO */
1324 	spin_lock_irqsave(&port->lock, flags);
1325 	dmaengine_terminate_async(chan);
1326 	sci_dma_rx_chan_invalidate(s);
1327 	sci_dma_rx_reenable_irq(s);
1328 	spin_unlock_irqrestore(&port->lock, flags);
1329 }
1330 
1331 static void sci_dma_tx_release(struct sci_port *s)
1332 {
1333 	struct dma_chan *chan = s->chan_tx_saved;
1334 
1335 	cancel_work_sync(&s->work_tx);
1336 	s->chan_tx_saved = s->chan_tx = NULL;
1337 	s->cookie_tx = -EINVAL;
1338 	dmaengine_terminate_sync(chan);
1339 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1340 			 DMA_TO_DEVICE);
1341 	dma_release_channel(chan);
1342 }
1343 
1344 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1345 {
1346 	struct dma_chan *chan = s->chan_rx;
1347 	struct uart_port *port = &s->port;
1348 	unsigned long flags;
1349 	int i;
1350 
1351 	for (i = 0; i < 2; i++) {
1352 		struct scatterlist *sg = &s->sg_rx[i];
1353 		struct dma_async_tx_descriptor *desc;
1354 
1355 		desc = dmaengine_prep_slave_sg(chan,
1356 			sg, 1, DMA_DEV_TO_MEM,
1357 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1358 		if (!desc)
1359 			goto fail;
1360 
1361 		desc->callback = sci_dma_rx_complete;
1362 		desc->callback_param = s;
1363 		s->cookie_rx[i] = dmaengine_submit(desc);
1364 		if (dma_submit_error(s->cookie_rx[i]))
1365 			goto fail;
1366 
1367 	}
1368 
1369 	s->active_rx = s->cookie_rx[0];
1370 
1371 	dma_async_issue_pending(chan);
1372 	return 0;
1373 
1374 fail:
1375 	/* Switch to PIO */
1376 	if (!port_lock_held)
1377 		spin_lock_irqsave(&port->lock, flags);
1378 	if (i)
1379 		dmaengine_terminate_async(chan);
1380 	sci_dma_rx_chan_invalidate(s);
1381 	sci_start_rx(port);
1382 	if (!port_lock_held)
1383 		spin_unlock_irqrestore(&port->lock, flags);
1384 	return -EAGAIN;
1385 }
1386 
1387 static void sci_dma_tx_work_fn(struct work_struct *work)
1388 {
1389 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1390 	struct dma_async_tx_descriptor *desc;
1391 	struct dma_chan *chan = s->chan_tx;
1392 	struct uart_port *port = &s->port;
1393 	struct circ_buf *xmit = &port->state->xmit;
1394 	unsigned long flags;
1395 	dma_addr_t buf;
1396 	int head, tail;
1397 
1398 	/*
1399 	 * DMA is idle now.
1400 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1401 	 * offsets and lengths. Since it is a circular buffer, we have to
1402 	 * transmit till the end, and then the rest. Take the port lock to get a
1403 	 * consistent xmit buffer state.
1404 	 */
1405 	spin_lock_irq(&port->lock);
1406 	head = xmit->head;
1407 	tail = xmit->tail;
1408 	buf = s->tx_dma_addr + tail;
1409 	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
1410 	if (!s->tx_dma_len) {
1411 		/* Transmit buffer has been flushed */
1412 		spin_unlock_irq(&port->lock);
1413 		return;
1414 	}
1415 
1416 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1417 					   DMA_MEM_TO_DEV,
1418 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1419 	if (!desc) {
1420 		spin_unlock_irq(&port->lock);
1421 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1422 		goto switch_to_pio;
1423 	}
1424 
1425 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1426 				   DMA_TO_DEVICE);
1427 
1428 	desc->callback = sci_dma_tx_complete;
1429 	desc->callback_param = s;
1430 	s->cookie_tx = dmaengine_submit(desc);
1431 	if (dma_submit_error(s->cookie_tx)) {
1432 		spin_unlock_irq(&port->lock);
1433 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1434 		goto switch_to_pio;
1435 	}
1436 
1437 	spin_unlock_irq(&port->lock);
1438 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1439 		__func__, xmit->buf, tail, head, s->cookie_tx);
1440 
1441 	dma_async_issue_pending(chan);
1442 	return;
1443 
1444 switch_to_pio:
1445 	spin_lock_irqsave(&port->lock, flags);
1446 	s->chan_tx = NULL;
1447 	sci_start_tx(port);
1448 	spin_unlock_irqrestore(&port->lock, flags);
1449 	return;
1450 }
1451 
1452 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1453 {
1454 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1455 	struct dma_chan *chan = s->chan_rx;
1456 	struct uart_port *port = &s->port;
1457 	struct dma_tx_state state;
1458 	enum dma_status status;
1459 	unsigned long flags;
1460 	unsigned int read;
1461 	int active, count;
1462 
1463 	dev_dbg(port->dev, "DMA Rx timed out\n");
1464 
1465 	spin_lock_irqsave(&port->lock, flags);
1466 
1467 	active = sci_dma_rx_find_active(s);
1468 	if (active < 0) {
1469 		spin_unlock_irqrestore(&port->lock, flags);
1470 		return HRTIMER_NORESTART;
1471 	}
1472 
1473 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1474 	if (status == DMA_COMPLETE) {
1475 		spin_unlock_irqrestore(&port->lock, flags);
1476 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1477 			s->active_rx, active);
1478 
1479 		/* Let packet complete handler take care of the packet */
1480 		return HRTIMER_NORESTART;
1481 	}
1482 
1483 	dmaengine_pause(chan);
1484 
1485 	/*
1486 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1487 	 * data keeps on coming until transaction is complete so check
1488 	 * for DMA_COMPLETE again
1489 	 * Let packet complete handler take care of the packet
1490 	 */
1491 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1492 	if (status == DMA_COMPLETE) {
1493 		spin_unlock_irqrestore(&port->lock, flags);
1494 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1495 		return HRTIMER_NORESTART;
1496 	}
1497 
1498 	/* Handle incomplete DMA receive */
1499 	dmaengine_terminate_async(s->chan_rx);
1500 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1501 
1502 	if (read) {
1503 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1504 		if (count)
1505 			tty_flip_buffer_push(&port->state->port);
1506 	}
1507 
1508 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1509 		sci_dma_rx_submit(s, true);
1510 
1511 	sci_dma_rx_reenable_irq(s);
1512 
1513 	spin_unlock_irqrestore(&port->lock, flags);
1514 
1515 	return HRTIMER_NORESTART;
1516 }
1517 
1518 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1519 					     enum dma_transfer_direction dir)
1520 {
1521 	struct dma_chan *chan;
1522 	struct dma_slave_config cfg;
1523 	int ret;
1524 
1525 	chan = dma_request_slave_channel(port->dev,
1526 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1527 	if (!chan) {
1528 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1529 		return NULL;
1530 	}
1531 
1532 	memset(&cfg, 0, sizeof(cfg));
1533 	cfg.direction = dir;
1534 	if (dir == DMA_MEM_TO_DEV) {
1535 		cfg.dst_addr = port->mapbase +
1536 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1537 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1538 	} else {
1539 		cfg.src_addr = port->mapbase +
1540 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1541 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1542 	}
1543 
1544 	ret = dmaengine_slave_config(chan, &cfg);
1545 	if (ret) {
1546 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1547 		dma_release_channel(chan);
1548 		return NULL;
1549 	}
1550 
1551 	return chan;
1552 }
1553 
1554 static void sci_request_dma(struct uart_port *port)
1555 {
1556 	struct sci_port *s = to_sci_port(port);
1557 	struct dma_chan *chan;
1558 
1559 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1560 
1561 	/*
1562 	 * DMA on console may interfere with Kernel log messages which use
1563 	 * plain putchar(). So, simply don't use it with a console.
1564 	 */
1565 	if (uart_console(port))
1566 		return;
1567 
1568 	if (!port->dev->of_node)
1569 		return;
1570 
1571 	s->cookie_tx = -EINVAL;
1572 
1573 	/*
1574 	 * Don't request a dma channel if no channel was specified
1575 	 * in the device tree.
1576 	 */
1577 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1578 		return;
1579 
1580 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1581 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1582 	if (chan) {
1583 		/* UART circular tx buffer is an aligned page. */
1584 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1585 						port->state->xmit.buf,
1586 						UART_XMIT_SIZE,
1587 						DMA_TO_DEVICE);
1588 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1589 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1590 			dma_release_channel(chan);
1591 		} else {
1592 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1593 				__func__, UART_XMIT_SIZE,
1594 				port->state->xmit.buf, &s->tx_dma_addr);
1595 
1596 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1597 			s->chan_tx_saved = s->chan_tx = chan;
1598 		}
1599 	}
1600 
1601 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1602 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1603 	if (chan) {
1604 		unsigned int i;
1605 		dma_addr_t dma;
1606 		void *buf;
1607 
1608 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1609 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1610 					 &dma, GFP_KERNEL);
1611 		if (!buf) {
1612 			dev_warn(port->dev,
1613 				 "Failed to allocate Rx dma buffer, using PIO\n");
1614 			dma_release_channel(chan);
1615 			return;
1616 		}
1617 
1618 		for (i = 0; i < 2; i++) {
1619 			struct scatterlist *sg = &s->sg_rx[i];
1620 
1621 			sg_init_table(sg, 1);
1622 			s->rx_buf[i] = buf;
1623 			sg_dma_address(sg) = dma;
1624 			sg_dma_len(sg) = s->buf_len_rx;
1625 
1626 			buf += s->buf_len_rx;
1627 			dma += s->buf_len_rx;
1628 		}
1629 
1630 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1631 		s->rx_timer.function = sci_dma_rx_timer_fn;
1632 
1633 		s->chan_rx_saved = s->chan_rx = chan;
1634 
1635 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1636 			sci_dma_rx_submit(s, false);
1637 	}
1638 }
1639 
1640 static void sci_free_dma(struct uart_port *port)
1641 {
1642 	struct sci_port *s = to_sci_port(port);
1643 
1644 	if (s->chan_tx_saved)
1645 		sci_dma_tx_release(s);
1646 	if (s->chan_rx_saved)
1647 		sci_dma_rx_release(s);
1648 }
1649 
1650 static void sci_flush_buffer(struct uart_port *port)
1651 {
1652 	struct sci_port *s = to_sci_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, and stop any
1657 	 * pending transfers
1658 	 */
1659 	s->tx_dma_len = 0;
1660 	if (s->chan_tx) {
1661 		dmaengine_terminate_async(s->chan_tx);
1662 		s->cookie_tx = -EINVAL;
1663 	}
1664 }
1665 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1666 static inline void sci_request_dma(struct uart_port *port)
1667 {
1668 }
1669 
1670 static inline void sci_free_dma(struct uart_port *port)
1671 {
1672 }
1673 
1674 #define sci_flush_buffer	NULL
1675 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1676 
1677 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1678 {
1679 	struct uart_port *port = ptr;
1680 	struct sci_port *s = to_sci_port(port);
1681 
1682 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1683 	if (s->chan_rx) {
1684 		u16 scr = serial_port_in(port, SCSCR);
1685 		u16 ssr = serial_port_in(port, SCxSR);
1686 
1687 		/* Disable future Rx interrupts */
1688 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1689 			disable_irq_nosync(irq);
1690 			scr |= SCSCR_RDRQE;
1691 		} else {
1692 			if (sci_dma_rx_submit(s, false) < 0)
1693 				goto handle_pio;
1694 
1695 			scr &= ~SCSCR_RIE;
1696 		}
1697 		serial_port_out(port, SCSCR, scr);
1698 		/* Clear current interrupt */
1699 		serial_port_out(port, SCxSR,
1700 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1701 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1702 			jiffies, s->rx_timeout);
1703 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1704 
1705 		return IRQ_HANDLED;
1706 	}
1707 
1708 handle_pio:
1709 #endif
1710 
1711 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1712 		if (!scif_rtrg_enabled(port))
1713 			scif_set_rtrg(port, s->rx_trigger);
1714 
1715 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1716 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1717 	}
1718 
1719 	/* I think sci_receive_chars has to be called irrespective
1720 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1721 	 * to be disabled?
1722 	 */
1723 	sci_receive_chars(port);
1724 
1725 	return IRQ_HANDLED;
1726 }
1727 
1728 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1729 {
1730 	struct uart_port *port = ptr;
1731 	unsigned long flags;
1732 
1733 	spin_lock_irqsave(&port->lock, flags);
1734 	sci_transmit_chars(port);
1735 	spin_unlock_irqrestore(&port->lock, flags);
1736 
1737 	return IRQ_HANDLED;
1738 }
1739 
1740 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1741 {
1742 	struct uart_port *port = ptr;
1743 
1744 	/* Handle BREAKs */
1745 	sci_handle_breaks(port);
1746 
1747 	/* drop invalid character received before break was detected */
1748 	serial_port_in(port, SCxRDR);
1749 
1750 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1751 
1752 	return IRQ_HANDLED;
1753 }
1754 
1755 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1756 {
1757 	struct uart_port *port = ptr;
1758 	struct sci_port *s = to_sci_port(port);
1759 
1760 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1761 		/* Break and Error interrupts are muxed */
1762 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1763 
1764 		/* Break Interrupt */
1765 		if (ssr_status & SCxSR_BRK(port))
1766 			sci_br_interrupt(irq, ptr);
1767 
1768 		/* Break only? */
1769 		if (!(ssr_status & SCxSR_ERRORS(port)))
1770 			return IRQ_HANDLED;
1771 	}
1772 
1773 	/* Handle errors */
1774 	if (port->type == PORT_SCI) {
1775 		if (sci_handle_errors(port)) {
1776 			/* discard character in rx buffer */
1777 			serial_port_in(port, SCxSR);
1778 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1779 		}
1780 	} else {
1781 		sci_handle_fifo_overrun(port);
1782 		if (!s->chan_rx)
1783 			sci_receive_chars(port);
1784 	}
1785 
1786 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1787 
1788 	/* Kick the transmission */
1789 	if (!s->chan_tx)
1790 		sci_tx_interrupt(irq, ptr);
1791 
1792 	return IRQ_HANDLED;
1793 }
1794 
1795 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1796 {
1797 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1798 	struct uart_port *port = ptr;
1799 	struct sci_port *s = to_sci_port(port);
1800 	irqreturn_t ret = IRQ_NONE;
1801 
1802 	ssr_status = serial_port_in(port, SCxSR);
1803 	scr_status = serial_port_in(port, SCSCR);
1804 	if (s->params->overrun_reg == SCxSR)
1805 		orer_status = ssr_status;
1806 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1807 		orer_status = serial_port_in(port, s->params->overrun_reg);
1808 
1809 	err_enabled = scr_status & port_rx_irq_mask(port);
1810 
1811 	/* Tx Interrupt */
1812 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1813 	    !s->chan_tx)
1814 		ret = sci_tx_interrupt(irq, ptr);
1815 
1816 	/*
1817 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1818 	 * DR flags
1819 	 */
1820 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1821 	    (scr_status & SCSCR_RIE))
1822 		ret = sci_rx_interrupt(irq, ptr);
1823 
1824 	/* Error Interrupt */
1825 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1826 		ret = sci_er_interrupt(irq, ptr);
1827 
1828 	/* Break Interrupt */
1829 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1830 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1831 		ret = sci_br_interrupt(irq, ptr);
1832 
1833 	/* Overrun Interrupt */
1834 	if (orer_status & s->params->overrun_mask) {
1835 		sci_handle_fifo_overrun(port);
1836 		ret = IRQ_HANDLED;
1837 	}
1838 
1839 	return ret;
1840 }
1841 
1842 static const struct sci_irq_desc {
1843 	const char	*desc;
1844 	irq_handler_t	handler;
1845 } sci_irq_desc[] = {
1846 	/*
1847 	 * Split out handlers, the default case.
1848 	 */
1849 	[SCIx_ERI_IRQ] = {
1850 		.desc = "rx err",
1851 		.handler = sci_er_interrupt,
1852 	},
1853 
1854 	[SCIx_RXI_IRQ] = {
1855 		.desc = "rx full",
1856 		.handler = sci_rx_interrupt,
1857 	},
1858 
1859 	[SCIx_TXI_IRQ] = {
1860 		.desc = "tx empty",
1861 		.handler = sci_tx_interrupt,
1862 	},
1863 
1864 	[SCIx_BRI_IRQ] = {
1865 		.desc = "break",
1866 		.handler = sci_br_interrupt,
1867 	},
1868 
1869 	[SCIx_DRI_IRQ] = {
1870 		.desc = "rx ready",
1871 		.handler = sci_rx_interrupt,
1872 	},
1873 
1874 	[SCIx_TEI_IRQ] = {
1875 		.desc = "tx end",
1876 		.handler = sci_tx_interrupt,
1877 	},
1878 
1879 	/*
1880 	 * Special muxed handler.
1881 	 */
1882 	[SCIx_MUX_IRQ] = {
1883 		.desc = "mux",
1884 		.handler = sci_mpxed_interrupt,
1885 	},
1886 };
1887 
1888 static int sci_request_irq(struct sci_port *port)
1889 {
1890 	struct uart_port *up = &port->port;
1891 	int i, j, w, ret = 0;
1892 
1893 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1894 		const struct sci_irq_desc *desc;
1895 		int irq;
1896 
1897 		/* Check if already registered (muxed) */
1898 		for (w = 0; w < i; w++)
1899 			if (port->irqs[w] == port->irqs[i])
1900 				w = i + 1;
1901 		if (w > i)
1902 			continue;
1903 
1904 		if (SCIx_IRQ_IS_MUXED(port)) {
1905 			i = SCIx_MUX_IRQ;
1906 			irq = up->irq;
1907 		} else {
1908 			irq = port->irqs[i];
1909 
1910 			/*
1911 			 * Certain port types won't support all of the
1912 			 * available interrupt sources.
1913 			 */
1914 			if (unlikely(irq < 0))
1915 				continue;
1916 		}
1917 
1918 		desc = sci_irq_desc + i;
1919 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1920 					    dev_name(up->dev), desc->desc);
1921 		if (!port->irqstr[j]) {
1922 			ret = -ENOMEM;
1923 			goto out_nomem;
1924 		}
1925 
1926 		ret = request_irq(irq, desc->handler, up->irqflags,
1927 				  port->irqstr[j], port);
1928 		if (unlikely(ret)) {
1929 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1930 			goto out_noirq;
1931 		}
1932 	}
1933 
1934 	return 0;
1935 
1936 out_noirq:
1937 	while (--i >= 0)
1938 		free_irq(port->irqs[i], port);
1939 
1940 out_nomem:
1941 	while (--j >= 0)
1942 		kfree(port->irqstr[j]);
1943 
1944 	return ret;
1945 }
1946 
1947 static void sci_free_irq(struct sci_port *port)
1948 {
1949 	int i, j;
1950 
1951 	/*
1952 	 * Intentionally in reverse order so we iterate over the muxed
1953 	 * IRQ first.
1954 	 */
1955 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1956 		int irq = port->irqs[i];
1957 
1958 		/*
1959 		 * Certain port types won't support all of the available
1960 		 * interrupt sources.
1961 		 */
1962 		if (unlikely(irq < 0))
1963 			continue;
1964 
1965 		/* Check if already freed (irq was muxed) */
1966 		for (j = 0; j < i; j++)
1967 			if (port->irqs[j] == irq)
1968 				j = i + 1;
1969 		if (j > i)
1970 			continue;
1971 
1972 		free_irq(port->irqs[i], port);
1973 		kfree(port->irqstr[i]);
1974 
1975 		if (SCIx_IRQ_IS_MUXED(port)) {
1976 			/* If there's only one IRQ, we're done. */
1977 			return;
1978 		}
1979 	}
1980 }
1981 
1982 static unsigned int sci_tx_empty(struct uart_port *port)
1983 {
1984 	unsigned short status = serial_port_in(port, SCxSR);
1985 	unsigned short in_tx_fifo = sci_txfill(port);
1986 
1987 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1988 }
1989 
1990 static void sci_set_rts(struct uart_port *port, bool state)
1991 {
1992 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1993 		u16 data = serial_port_in(port, SCPDR);
1994 
1995 		/* Active low */
1996 		if (state)
1997 			data &= ~SCPDR_RTSD;
1998 		else
1999 			data |= SCPDR_RTSD;
2000 		serial_port_out(port, SCPDR, data);
2001 
2002 		/* RTS# is output */
2003 		serial_port_out(port, SCPCR,
2004 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2005 	} else if (sci_getreg(port, SCSPTR)->size) {
2006 		u16 ctrl = serial_port_in(port, SCSPTR);
2007 
2008 		/* Active low */
2009 		if (state)
2010 			ctrl &= ~SCSPTR_RTSDT;
2011 		else
2012 			ctrl |= SCSPTR_RTSDT;
2013 		serial_port_out(port, SCSPTR, ctrl);
2014 	}
2015 }
2016 
2017 static bool sci_get_cts(struct uart_port *port)
2018 {
2019 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2020 		/* Active low */
2021 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2022 	} else if (sci_getreg(port, SCSPTR)->size) {
2023 		/* Active low */
2024 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2025 	}
2026 
2027 	return true;
2028 }
2029 
2030 /*
2031  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2032  * CTS/RTS is supported in hardware by at least one port and controlled
2033  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2034  * handled via the ->init_pins() op, which is a bit of a one-way street,
2035  * lacking any ability to defer pin control -- this will later be
2036  * converted over to the GPIO framework).
2037  *
2038  * Other modes (such as loopback) are supported generically on certain
2039  * port types, but not others. For these it's sufficient to test for the
2040  * existence of the support register and simply ignore the port type.
2041  */
2042 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2043 {
2044 	struct sci_port *s = to_sci_port(port);
2045 
2046 	if (mctrl & TIOCM_LOOP) {
2047 		const struct plat_sci_reg *reg;
2048 
2049 		/*
2050 		 * Standard loopback mode for SCFCR ports.
2051 		 */
2052 		reg = sci_getreg(port, SCFCR);
2053 		if (reg->size)
2054 			serial_port_out(port, SCFCR,
2055 					serial_port_in(port, SCFCR) |
2056 					SCFCR_LOOP);
2057 	}
2058 
2059 	mctrl_gpio_set(s->gpios, mctrl);
2060 
2061 	if (!s->has_rtscts)
2062 		return;
2063 
2064 	if (!(mctrl & TIOCM_RTS)) {
2065 		/* Disable Auto RTS */
2066 		serial_port_out(port, SCFCR,
2067 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2068 
2069 		/* Clear RTS */
2070 		sci_set_rts(port, 0);
2071 	} else if (s->autorts) {
2072 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2073 			/* Enable RTS# pin function */
2074 			serial_port_out(port, SCPCR,
2075 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2076 		}
2077 
2078 		/* Enable Auto RTS */
2079 		serial_port_out(port, SCFCR,
2080 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2081 	} else {
2082 		/* Set RTS */
2083 		sci_set_rts(port, 1);
2084 	}
2085 }
2086 
2087 static unsigned int sci_get_mctrl(struct uart_port *port)
2088 {
2089 	struct sci_port *s = to_sci_port(port);
2090 	struct mctrl_gpios *gpios = s->gpios;
2091 	unsigned int mctrl = 0;
2092 
2093 	mctrl_gpio_get(gpios, &mctrl);
2094 
2095 	/*
2096 	 * CTS/RTS is handled in hardware when supported, while nothing
2097 	 * else is wired up.
2098 	 */
2099 	if (s->autorts) {
2100 		if (sci_get_cts(port))
2101 			mctrl |= TIOCM_CTS;
2102 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2103 		mctrl |= TIOCM_CTS;
2104 	}
2105 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2106 		mctrl |= TIOCM_DSR;
2107 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2108 		mctrl |= TIOCM_CAR;
2109 
2110 	return mctrl;
2111 }
2112 
2113 static void sci_enable_ms(struct uart_port *port)
2114 {
2115 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2116 }
2117 
2118 static void sci_break_ctl(struct uart_port *port, int break_state)
2119 {
2120 	unsigned short scscr, scsptr;
2121 	unsigned long flags;
2122 
2123 	/* check whether the port has SCSPTR */
2124 	if (!sci_getreg(port, SCSPTR)->size) {
2125 		/*
2126 		 * Not supported by hardware. Most parts couple break and rx
2127 		 * interrupts together, with break detection always enabled.
2128 		 */
2129 		return;
2130 	}
2131 
2132 	spin_lock_irqsave(&port->lock, flags);
2133 	scsptr = serial_port_in(port, SCSPTR);
2134 	scscr = serial_port_in(port, SCSCR);
2135 
2136 	if (break_state == -1) {
2137 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2138 		scscr &= ~SCSCR_TE;
2139 	} else {
2140 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2141 		scscr |= SCSCR_TE;
2142 	}
2143 
2144 	serial_port_out(port, SCSPTR, scsptr);
2145 	serial_port_out(port, SCSCR, scscr);
2146 	spin_unlock_irqrestore(&port->lock, flags);
2147 }
2148 
2149 static int sci_startup(struct uart_port *port)
2150 {
2151 	struct sci_port *s = to_sci_port(port);
2152 	int ret;
2153 
2154 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2155 
2156 	sci_request_dma(port);
2157 
2158 	ret = sci_request_irq(s);
2159 	if (unlikely(ret < 0)) {
2160 		sci_free_dma(port);
2161 		return ret;
2162 	}
2163 
2164 	return 0;
2165 }
2166 
2167 static void sci_shutdown(struct uart_port *port)
2168 {
2169 	struct sci_port *s = to_sci_port(port);
2170 	unsigned long flags;
2171 	u16 scr;
2172 
2173 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2174 
2175 	s->autorts = false;
2176 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2177 
2178 	spin_lock_irqsave(&port->lock, flags);
2179 	sci_stop_rx(port);
2180 	sci_stop_tx(port);
2181 	/*
2182 	 * Stop RX and TX, disable related interrupts, keep clock source
2183 	 * and HSCIF TOT bits
2184 	 */
2185 	scr = serial_port_in(port, SCSCR);
2186 	serial_port_out(port, SCSCR, scr &
2187 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2188 	spin_unlock_irqrestore(&port->lock, flags);
2189 
2190 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2191 	if (s->chan_rx_saved) {
2192 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2193 			port->line);
2194 		hrtimer_cancel(&s->rx_timer);
2195 	}
2196 #endif
2197 
2198 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2199 		del_timer_sync(&s->rx_fifo_timer);
2200 	sci_free_irq(s);
2201 	sci_free_dma(port);
2202 }
2203 
2204 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2205 			unsigned int *srr)
2206 {
2207 	unsigned long freq = s->clk_rates[SCI_SCK];
2208 	int err, min_err = INT_MAX;
2209 	unsigned int sr;
2210 
2211 	if (s->port.type != PORT_HSCIF)
2212 		freq *= 2;
2213 
2214 	for_each_sr(sr, s) {
2215 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2216 		if (abs(err) >= abs(min_err))
2217 			continue;
2218 
2219 		min_err = err;
2220 		*srr = sr - 1;
2221 
2222 		if (!err)
2223 			break;
2224 	}
2225 
2226 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2227 		*srr + 1);
2228 	return min_err;
2229 }
2230 
2231 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2232 			unsigned long freq, unsigned int *dlr,
2233 			unsigned int *srr)
2234 {
2235 	int err, min_err = INT_MAX;
2236 	unsigned int sr, dl;
2237 
2238 	if (s->port.type != PORT_HSCIF)
2239 		freq *= 2;
2240 
2241 	for_each_sr(sr, s) {
2242 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2243 		dl = clamp(dl, 1U, 65535U);
2244 
2245 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2246 		if (abs(err) >= abs(min_err))
2247 			continue;
2248 
2249 		min_err = err;
2250 		*dlr = dl;
2251 		*srr = sr - 1;
2252 
2253 		if (!err)
2254 			break;
2255 	}
2256 
2257 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2258 		min_err, *dlr, *srr + 1);
2259 	return min_err;
2260 }
2261 
2262 /* calculate sample rate, BRR, and clock select */
2263 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2264 			  unsigned int *brr, unsigned int *srr,
2265 			  unsigned int *cks)
2266 {
2267 	unsigned long freq = s->clk_rates[SCI_FCK];
2268 	unsigned int sr, br, prediv, scrate, c;
2269 	int err, min_err = INT_MAX;
2270 
2271 	if (s->port.type != PORT_HSCIF)
2272 		freq *= 2;
2273 
2274 	/*
2275 	 * Find the combination of sample rate and clock select with the
2276 	 * smallest deviation from the desired baud rate.
2277 	 * Prefer high sample rates to maximise the receive margin.
2278 	 *
2279 	 * M: Receive margin (%)
2280 	 * N: Ratio of bit rate to clock (N = sampling rate)
2281 	 * D: Clock duty (D = 0 to 1.0)
2282 	 * L: Frame length (L = 9 to 12)
2283 	 * F: Absolute value of clock frequency deviation
2284 	 *
2285 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2286 	 *      (|D - 0.5| / N * (1 + F))|
2287 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2288 	 */
2289 	for_each_sr(sr, s) {
2290 		for (c = 0; c <= 3; c++) {
2291 			/* integerized formulas from HSCIF documentation */
2292 			prediv = sr << (2 * c + 1);
2293 
2294 			/*
2295 			 * We need to calculate:
2296 			 *
2297 			 *     br = freq / (prediv * bps) clamped to [1..256]
2298 			 *     err = freq / (br * prediv) - bps
2299 			 *
2300 			 * Watch out for overflow when calculating the desired
2301 			 * sampling clock rate!
2302 			 */
2303 			if (bps > UINT_MAX / prediv)
2304 				break;
2305 
2306 			scrate = prediv * bps;
2307 			br = DIV_ROUND_CLOSEST(freq, scrate);
2308 			br = clamp(br, 1U, 256U);
2309 
2310 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2311 			if (abs(err) >= abs(min_err))
2312 				continue;
2313 
2314 			min_err = err;
2315 			*brr = br - 1;
2316 			*srr = sr - 1;
2317 			*cks = c;
2318 
2319 			if (!err)
2320 				goto found;
2321 		}
2322 	}
2323 
2324 found:
2325 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2326 		min_err, *brr, *srr + 1, *cks);
2327 	return min_err;
2328 }
2329 
2330 static void sci_reset(struct uart_port *port)
2331 {
2332 	const struct plat_sci_reg *reg;
2333 	unsigned int status;
2334 	struct sci_port *s = to_sci_port(port);
2335 
2336 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2337 
2338 	reg = sci_getreg(port, SCFCR);
2339 	if (reg->size)
2340 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2341 
2342 	sci_clear_SCxSR(port,
2343 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2344 			SCxSR_BREAK_CLEAR(port));
2345 	if (sci_getreg(port, SCLSR)->size) {
2346 		status = serial_port_in(port, SCLSR);
2347 		status &= ~(SCLSR_TO | SCLSR_ORER);
2348 		serial_port_out(port, SCLSR, status);
2349 	}
2350 
2351 	if (s->rx_trigger > 1) {
2352 		if (s->rx_fifo_timeout) {
2353 			scif_set_rtrg(port, 1);
2354 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2355 		} else {
2356 			if (port->type == PORT_SCIFA ||
2357 			    port->type == PORT_SCIFB)
2358 				scif_set_rtrg(port, 1);
2359 			else
2360 				scif_set_rtrg(port, s->rx_trigger);
2361 		}
2362 	}
2363 }
2364 
2365 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2366 		            const struct ktermios *old)
2367 {
2368 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2369 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2370 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2371 	struct sci_port *s = to_sci_port(port);
2372 	const struct plat_sci_reg *reg;
2373 	int min_err = INT_MAX, err;
2374 	unsigned long max_freq = 0;
2375 	int best_clk = -1;
2376 	unsigned long flags;
2377 
2378 	if ((termios->c_cflag & CSIZE) == CS7) {
2379 		smr_val |= SCSMR_CHR;
2380 	} else {
2381 		termios->c_cflag &= ~CSIZE;
2382 		termios->c_cflag |= CS8;
2383 	}
2384 	if (termios->c_cflag & PARENB)
2385 		smr_val |= SCSMR_PE;
2386 	if (termios->c_cflag & PARODD)
2387 		smr_val |= SCSMR_PE | SCSMR_ODD;
2388 	if (termios->c_cflag & CSTOPB)
2389 		smr_val |= SCSMR_STOP;
2390 
2391 	/*
2392 	 * earlyprintk comes here early on with port->uartclk set to zero.
2393 	 * the clock framework is not up and running at this point so here
2394 	 * we assume that 115200 is the maximum baud rate. please note that
2395 	 * the baud rate is not programmed during earlyprintk - it is assumed
2396 	 * that the previous boot loader has enabled required clocks and
2397 	 * setup the baud rate generator hardware for us already.
2398 	 */
2399 	if (!port->uartclk) {
2400 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2401 		goto done;
2402 	}
2403 
2404 	for (i = 0; i < SCI_NUM_CLKS; i++)
2405 		max_freq = max(max_freq, s->clk_rates[i]);
2406 
2407 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2408 	if (!baud)
2409 		goto done;
2410 
2411 	/*
2412 	 * There can be multiple sources for the sampling clock.  Find the one
2413 	 * that gives us the smallest deviation from the desired baud rate.
2414 	 */
2415 
2416 	/* Optional Undivided External Clock */
2417 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2418 	    port->type != PORT_SCIFB) {
2419 		err = sci_sck_calc(s, baud, &srr1);
2420 		if (abs(err) < abs(min_err)) {
2421 			best_clk = SCI_SCK;
2422 			scr_val = SCSCR_CKE1;
2423 			sccks = SCCKS_CKS;
2424 			min_err = err;
2425 			srr = srr1;
2426 			if (!err)
2427 				goto done;
2428 		}
2429 	}
2430 
2431 	/* Optional BRG Frequency Divided External Clock */
2432 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2433 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2434 				   &srr1);
2435 		if (abs(err) < abs(min_err)) {
2436 			best_clk = SCI_SCIF_CLK;
2437 			scr_val = SCSCR_CKE1;
2438 			sccks = 0;
2439 			min_err = err;
2440 			dl = dl1;
2441 			srr = srr1;
2442 			if (!err)
2443 				goto done;
2444 		}
2445 	}
2446 
2447 	/* Optional BRG Frequency Divided Internal Clock */
2448 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2449 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2450 				   &srr1);
2451 		if (abs(err) < abs(min_err)) {
2452 			best_clk = SCI_BRG_INT;
2453 			scr_val = SCSCR_CKE1;
2454 			sccks = SCCKS_XIN;
2455 			min_err = err;
2456 			dl = dl1;
2457 			srr = srr1;
2458 			if (!min_err)
2459 				goto done;
2460 		}
2461 	}
2462 
2463 	/* Divided Functional Clock using standard Bit Rate Register */
2464 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2465 	if (abs(err) < abs(min_err)) {
2466 		best_clk = SCI_FCK;
2467 		scr_val = 0;
2468 		min_err = err;
2469 		brr = brr1;
2470 		srr = srr1;
2471 		cks = cks1;
2472 	}
2473 
2474 done:
2475 	if (best_clk >= 0)
2476 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2477 			s->clks[best_clk], baud, min_err);
2478 
2479 	sci_port_enable(s);
2480 
2481 	/*
2482 	 * Program the optional External Baud Rate Generator (BRG) first.
2483 	 * It controls the mux to select (H)SCK or frequency divided clock.
2484 	 */
2485 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2486 		serial_port_out(port, SCDL, dl);
2487 		serial_port_out(port, SCCKS, sccks);
2488 	}
2489 
2490 	spin_lock_irqsave(&port->lock, flags);
2491 
2492 	sci_reset(port);
2493 
2494 	uart_update_timeout(port, termios->c_cflag, baud);
2495 
2496 	/* byte size and parity */
2497 	bits = tty_get_frame_size(termios->c_cflag);
2498 
2499 	if (sci_getreg(port, SEMR)->size)
2500 		serial_port_out(port, SEMR, 0);
2501 
2502 	if (best_clk >= 0) {
2503 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2504 			switch (srr + 1) {
2505 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2506 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2507 			case 11: smr_val |= SCSMR_SRC_11; break;
2508 			case 13: smr_val |= SCSMR_SRC_13; break;
2509 			case 16: smr_val |= SCSMR_SRC_16; break;
2510 			case 17: smr_val |= SCSMR_SRC_17; break;
2511 			case 19: smr_val |= SCSMR_SRC_19; break;
2512 			case 27: smr_val |= SCSMR_SRC_27; break;
2513 			}
2514 		smr_val |= cks;
2515 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2516 		serial_port_out(port, SCSMR, smr_val);
2517 		serial_port_out(port, SCBRR, brr);
2518 		if (sci_getreg(port, HSSRR)->size) {
2519 			unsigned int hssrr = srr | HSCIF_SRE;
2520 			/* Calculate deviation from intended rate at the
2521 			 * center of the last stop bit in sampling clocks.
2522 			 */
2523 			int last_stop = bits * 2 - 1;
2524 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2525 							  (int)(srr + 1),
2526 							  2 * (int)baud);
2527 
2528 			if (abs(deviation) >= 2) {
2529 				/* At least two sampling clocks off at the
2530 				 * last stop bit; we can increase the error
2531 				 * margin by shifting the sampling point.
2532 				 */
2533 				int shift = clamp(deviation / 2, -8, 7);
2534 
2535 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2536 					 HSCIF_SRHP_MASK;
2537 				hssrr |= HSCIF_SRDE;
2538 			}
2539 			serial_port_out(port, HSSRR, hssrr);
2540 		}
2541 
2542 		/* Wait one bit interval */
2543 		udelay((1000000 + (baud - 1)) / baud);
2544 	} else {
2545 		/* Don't touch the bit rate configuration */
2546 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2547 		smr_val |= serial_port_in(port, SCSMR) &
2548 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2549 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2550 		serial_port_out(port, SCSMR, smr_val);
2551 	}
2552 
2553 	sci_init_pins(port, termios->c_cflag);
2554 
2555 	port->status &= ~UPSTAT_AUTOCTS;
2556 	s->autorts = false;
2557 	reg = sci_getreg(port, SCFCR);
2558 	if (reg->size) {
2559 		unsigned short ctrl = serial_port_in(port, SCFCR);
2560 
2561 		if ((port->flags & UPF_HARD_FLOW) &&
2562 		    (termios->c_cflag & CRTSCTS)) {
2563 			/* There is no CTS interrupt to restart the hardware */
2564 			port->status |= UPSTAT_AUTOCTS;
2565 			/* MCE is enabled when RTS is raised */
2566 			s->autorts = true;
2567 		}
2568 
2569 		/*
2570 		 * As we've done a sci_reset() above, ensure we don't
2571 		 * interfere with the FIFOs while toggling MCE. As the
2572 		 * reset values could still be set, simply mask them out.
2573 		 */
2574 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2575 
2576 		serial_port_out(port, SCFCR, ctrl);
2577 	}
2578 	if (port->flags & UPF_HARD_FLOW) {
2579 		/* Refresh (Auto) RTS */
2580 		sci_set_mctrl(port, port->mctrl);
2581 	}
2582 
2583 	scr_val |= SCSCR_RE | SCSCR_TE |
2584 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2585 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2586 	if ((srr + 1 == 5) &&
2587 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2588 		/*
2589 		 * In asynchronous mode, when the sampling rate is 1/5, first
2590 		 * received data may become invalid on some SCIFA and SCIFB.
2591 		 * To avoid this problem wait more than 1 serial data time (1
2592 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2593 		 */
2594 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2595 	}
2596 
2597 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2598 	s->rx_frame = (10000 * bits) / (baud / 100);
2599 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2600 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2601 #endif
2602 
2603 	if ((termios->c_cflag & CREAD) != 0)
2604 		sci_start_rx(port);
2605 
2606 	spin_unlock_irqrestore(&port->lock, flags);
2607 
2608 	sci_port_disable(s);
2609 
2610 	if (UART_ENABLE_MS(port, termios->c_cflag))
2611 		sci_enable_ms(port);
2612 }
2613 
2614 static void sci_pm(struct uart_port *port, unsigned int state,
2615 		   unsigned int oldstate)
2616 {
2617 	struct sci_port *sci_port = to_sci_port(port);
2618 
2619 	switch (state) {
2620 	case UART_PM_STATE_OFF:
2621 		sci_port_disable(sci_port);
2622 		break;
2623 	default:
2624 		sci_port_enable(sci_port);
2625 		break;
2626 	}
2627 }
2628 
2629 static const char *sci_type(struct uart_port *port)
2630 {
2631 	switch (port->type) {
2632 	case PORT_IRDA:
2633 		return "irda";
2634 	case PORT_SCI:
2635 		return "sci";
2636 	case PORT_SCIF:
2637 		return "scif";
2638 	case PORT_SCIFA:
2639 		return "scifa";
2640 	case PORT_SCIFB:
2641 		return "scifb";
2642 	case PORT_HSCIF:
2643 		return "hscif";
2644 	}
2645 
2646 	return NULL;
2647 }
2648 
2649 static int sci_remap_port(struct uart_port *port)
2650 {
2651 	struct sci_port *sport = to_sci_port(port);
2652 
2653 	/*
2654 	 * Nothing to do if there's already an established membase.
2655 	 */
2656 	if (port->membase)
2657 		return 0;
2658 
2659 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2660 		port->membase = ioremap(port->mapbase, sport->reg_size);
2661 		if (unlikely(!port->membase)) {
2662 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2663 			return -ENXIO;
2664 		}
2665 	} else {
2666 		/*
2667 		 * For the simple (and majority of) cases where we don't
2668 		 * need to do any remapping, just cast the cookie
2669 		 * directly.
2670 		 */
2671 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2672 	}
2673 
2674 	return 0;
2675 }
2676 
2677 static void sci_release_port(struct uart_port *port)
2678 {
2679 	struct sci_port *sport = to_sci_port(port);
2680 
2681 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2682 		iounmap(port->membase);
2683 		port->membase = NULL;
2684 	}
2685 
2686 	release_mem_region(port->mapbase, sport->reg_size);
2687 }
2688 
2689 static int sci_request_port(struct uart_port *port)
2690 {
2691 	struct resource *res;
2692 	struct sci_port *sport = to_sci_port(port);
2693 	int ret;
2694 
2695 	res = request_mem_region(port->mapbase, sport->reg_size,
2696 				 dev_name(port->dev));
2697 	if (unlikely(res == NULL)) {
2698 		dev_err(port->dev, "request_mem_region failed.");
2699 		return -EBUSY;
2700 	}
2701 
2702 	ret = sci_remap_port(port);
2703 	if (unlikely(ret != 0)) {
2704 		release_resource(res);
2705 		return ret;
2706 	}
2707 
2708 	return 0;
2709 }
2710 
2711 static void sci_config_port(struct uart_port *port, int flags)
2712 {
2713 	if (flags & UART_CONFIG_TYPE) {
2714 		struct sci_port *sport = to_sci_port(port);
2715 
2716 		port->type = sport->cfg->type;
2717 		sci_request_port(port);
2718 	}
2719 }
2720 
2721 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2722 {
2723 	if (ser->baud_base < 2400)
2724 		/* No paper tape reader for Mitch.. */
2725 		return -EINVAL;
2726 
2727 	return 0;
2728 }
2729 
2730 static const struct uart_ops sci_uart_ops = {
2731 	.tx_empty	= sci_tx_empty,
2732 	.set_mctrl	= sci_set_mctrl,
2733 	.get_mctrl	= sci_get_mctrl,
2734 	.start_tx	= sci_start_tx,
2735 	.stop_tx	= sci_stop_tx,
2736 	.stop_rx	= sci_stop_rx,
2737 	.enable_ms	= sci_enable_ms,
2738 	.break_ctl	= sci_break_ctl,
2739 	.startup	= sci_startup,
2740 	.shutdown	= sci_shutdown,
2741 	.flush_buffer	= sci_flush_buffer,
2742 	.set_termios	= sci_set_termios,
2743 	.pm		= sci_pm,
2744 	.type		= sci_type,
2745 	.release_port	= sci_release_port,
2746 	.request_port	= sci_request_port,
2747 	.config_port	= sci_config_port,
2748 	.verify_port	= sci_verify_port,
2749 #ifdef CONFIG_CONSOLE_POLL
2750 	.poll_get_char	= sci_poll_get_char,
2751 	.poll_put_char	= sci_poll_put_char,
2752 #endif
2753 };
2754 
2755 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2756 {
2757 	const char *clk_names[] = {
2758 		[SCI_FCK] = "fck",
2759 		[SCI_SCK] = "sck",
2760 		[SCI_BRG_INT] = "brg_int",
2761 		[SCI_SCIF_CLK] = "scif_clk",
2762 	};
2763 	struct clk *clk;
2764 	unsigned int i;
2765 
2766 	if (sci_port->cfg->type == PORT_HSCIF)
2767 		clk_names[SCI_SCK] = "hsck";
2768 
2769 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2770 		clk = devm_clk_get_optional(dev, clk_names[i]);
2771 		if (IS_ERR(clk))
2772 			return PTR_ERR(clk);
2773 
2774 		if (!clk && i == SCI_FCK) {
2775 			/*
2776 			 * Not all SH platforms declare a clock lookup entry
2777 			 * for SCI devices, in which case we need to get the
2778 			 * global "peripheral_clk" clock.
2779 			 */
2780 			clk = devm_clk_get(dev, "peripheral_clk");
2781 			if (IS_ERR(clk))
2782 				return dev_err_probe(dev, PTR_ERR(clk),
2783 						     "failed to get %s\n",
2784 						     clk_names[i]);
2785 		}
2786 
2787 		if (!clk)
2788 			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2789 		else
2790 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2791 				clk, clk_get_rate(clk));
2792 		sci_port->clks[i] = clk;
2793 	}
2794 	return 0;
2795 }
2796 
2797 static const struct sci_port_params *
2798 sci_probe_regmap(const struct plat_sci_port *cfg)
2799 {
2800 	unsigned int regtype;
2801 
2802 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2803 		return &sci_port_params[cfg->regtype];
2804 
2805 	switch (cfg->type) {
2806 	case PORT_SCI:
2807 		regtype = SCIx_SCI_REGTYPE;
2808 		break;
2809 	case PORT_IRDA:
2810 		regtype = SCIx_IRDA_REGTYPE;
2811 		break;
2812 	case PORT_SCIFA:
2813 		regtype = SCIx_SCIFA_REGTYPE;
2814 		break;
2815 	case PORT_SCIFB:
2816 		regtype = SCIx_SCIFB_REGTYPE;
2817 		break;
2818 	case PORT_SCIF:
2819 		/*
2820 		 * The SH-4 is a bit of a misnomer here, although that's
2821 		 * where this particular port layout originated. This
2822 		 * configuration (or some slight variation thereof)
2823 		 * remains the dominant model for all SCIFs.
2824 		 */
2825 		regtype = SCIx_SH4_SCIF_REGTYPE;
2826 		break;
2827 	case PORT_HSCIF:
2828 		regtype = SCIx_HSCIF_REGTYPE;
2829 		break;
2830 	default:
2831 		pr_err("Can't probe register map for given port\n");
2832 		return NULL;
2833 	}
2834 
2835 	return &sci_port_params[regtype];
2836 }
2837 
2838 static int sci_init_single(struct platform_device *dev,
2839 			   struct sci_port *sci_port, unsigned int index,
2840 			   const struct plat_sci_port *p, bool early)
2841 {
2842 	struct uart_port *port = &sci_port->port;
2843 	const struct resource *res;
2844 	unsigned int i;
2845 	int ret;
2846 
2847 	sci_port->cfg	= p;
2848 
2849 	port->ops	= &sci_uart_ops;
2850 	port->iotype	= UPIO_MEM;
2851 	port->line	= index;
2852 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2853 
2854 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2855 	if (res == NULL)
2856 		return -ENOMEM;
2857 
2858 	port->mapbase = res->start;
2859 	sci_port->reg_size = resource_size(res);
2860 
2861 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2862 		if (i)
2863 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2864 		else
2865 			sci_port->irqs[i] = platform_get_irq(dev, i);
2866 	}
2867 
2868 	/*
2869 	 * The fourth interrupt on SCI port is transmit end interrupt, so
2870 	 * shuffle the interrupts.
2871 	 */
2872 	if (p->type == PORT_SCI)
2873 		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
2874 
2875 	/* The SCI generates several interrupts. They can be muxed together or
2876 	 * connected to different interrupt lines. In the muxed case only one
2877 	 * interrupt resource is specified as there is only one interrupt ID.
2878 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2879 	 * from the SCI, however those signals might have their own individual
2880 	 * interrupt ID numbers, or muxed together with another interrupt.
2881 	 */
2882 	if (sci_port->irqs[0] < 0)
2883 		return -ENXIO;
2884 
2885 	if (sci_port->irqs[1] < 0)
2886 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2887 			sci_port->irqs[i] = sci_port->irqs[0];
2888 
2889 	sci_port->params = sci_probe_regmap(p);
2890 	if (unlikely(sci_port->params == NULL))
2891 		return -EINVAL;
2892 
2893 	switch (p->type) {
2894 	case PORT_SCIFB:
2895 		sci_port->rx_trigger = 48;
2896 		break;
2897 	case PORT_HSCIF:
2898 		sci_port->rx_trigger = 64;
2899 		break;
2900 	case PORT_SCIFA:
2901 		sci_port->rx_trigger = 32;
2902 		break;
2903 	case PORT_SCIF:
2904 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2905 			/* RX triggering not implemented for this IP */
2906 			sci_port->rx_trigger = 1;
2907 		else
2908 			sci_port->rx_trigger = 8;
2909 		break;
2910 	default:
2911 		sci_port->rx_trigger = 1;
2912 		break;
2913 	}
2914 
2915 	sci_port->rx_fifo_timeout = 0;
2916 	sci_port->hscif_tot = 0;
2917 
2918 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2919 	 * match the SoC datasheet, this should be investigated. Let platform
2920 	 * data override the sampling rate for now.
2921 	 */
2922 	sci_port->sampling_rate_mask = p->sampling_rate
2923 				     ? SCI_SR(p->sampling_rate)
2924 				     : sci_port->params->sampling_rate_mask;
2925 
2926 	if (!early) {
2927 		ret = sci_init_clocks(sci_port, &dev->dev);
2928 		if (ret < 0)
2929 			return ret;
2930 
2931 		port->dev = &dev->dev;
2932 
2933 		pm_runtime_enable(&dev->dev);
2934 	}
2935 
2936 	port->type		= p->type;
2937 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2938 	port->fifosize		= sci_port->params->fifosize;
2939 
2940 	if (port->type == PORT_SCI && !dev->dev.of_node) {
2941 		if (sci_port->reg_size >= 0x20)
2942 			port->regshift = 2;
2943 		else
2944 			port->regshift = 1;
2945 	}
2946 
2947 	/*
2948 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2949 	 * for the multi-IRQ ports, which is where we are primarily
2950 	 * concerned with the shutdown path synchronization.
2951 	 *
2952 	 * For the muxed case there's nothing more to do.
2953 	 */
2954 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2955 	port->irqflags		= 0;
2956 
2957 	port->serial_in		= sci_serial_in;
2958 	port->serial_out	= sci_serial_out;
2959 
2960 	return 0;
2961 }
2962 
2963 static void sci_cleanup_single(struct sci_port *port)
2964 {
2965 	pm_runtime_disable(port->port.dev);
2966 }
2967 
2968 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2969     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2970 static void serial_console_putchar(struct uart_port *port, unsigned char ch)
2971 {
2972 	sci_poll_put_char(port, ch);
2973 }
2974 
2975 /*
2976  *	Print a string to the serial port trying not to disturb
2977  *	any possible real use of the port...
2978  */
2979 static void serial_console_write(struct console *co, const char *s,
2980 				 unsigned count)
2981 {
2982 	struct sci_port *sci_port = &sci_ports[co->index];
2983 	struct uart_port *port = &sci_port->port;
2984 	unsigned short bits, ctrl, ctrl_temp;
2985 	unsigned long flags;
2986 	int locked = 1;
2987 
2988 	if (port->sysrq)
2989 		locked = 0;
2990 	else if (oops_in_progress)
2991 		locked = spin_trylock_irqsave(&port->lock, flags);
2992 	else
2993 		spin_lock_irqsave(&port->lock, flags);
2994 
2995 	/* first save SCSCR then disable interrupts, keep clock source */
2996 	ctrl = serial_port_in(port, SCSCR);
2997 	ctrl_temp = SCSCR_RE | SCSCR_TE |
2998 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2999 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3000 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3001 
3002 	uart_console_write(port, s, count, serial_console_putchar);
3003 
3004 	/* wait until fifo is empty and last bit has been transmitted */
3005 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3006 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3007 		cpu_relax();
3008 
3009 	/* restore the SCSCR */
3010 	serial_port_out(port, SCSCR, ctrl);
3011 
3012 	if (locked)
3013 		spin_unlock_irqrestore(&port->lock, flags);
3014 }
3015 
3016 static int serial_console_setup(struct console *co, char *options)
3017 {
3018 	struct sci_port *sci_port;
3019 	struct uart_port *port;
3020 	int baud = 115200;
3021 	int bits = 8;
3022 	int parity = 'n';
3023 	int flow = 'n';
3024 	int ret;
3025 
3026 	/*
3027 	 * Refuse to handle any bogus ports.
3028 	 */
3029 	if (co->index < 0 || co->index >= SCI_NPORTS)
3030 		return -ENODEV;
3031 
3032 	sci_port = &sci_ports[co->index];
3033 	port = &sci_port->port;
3034 
3035 	/*
3036 	 * Refuse to handle uninitialized ports.
3037 	 */
3038 	if (!port->ops)
3039 		return -ENODEV;
3040 
3041 	ret = sci_remap_port(port);
3042 	if (unlikely(ret != 0))
3043 		return ret;
3044 
3045 	if (options)
3046 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3047 
3048 	return uart_set_options(port, co, baud, parity, bits, flow);
3049 }
3050 
3051 static struct console serial_console = {
3052 	.name		= "ttySC",
3053 	.device		= uart_console_device,
3054 	.write		= serial_console_write,
3055 	.setup		= serial_console_setup,
3056 	.flags		= CON_PRINTBUFFER,
3057 	.index		= -1,
3058 	.data		= &sci_uart_driver,
3059 };
3060 
3061 #ifdef CONFIG_SUPERH
3062 static char early_serial_buf[32];
3063 
3064 static int early_serial_console_setup(struct console *co, char *options)
3065 {
3066 	/*
3067 	 * This early console is always registered using the earlyprintk=
3068 	 * parameter, which does not call add_preferred_console(). Thus
3069 	 * @options is always NULL and the options for this early console
3070 	 * are passed using a custom buffer.
3071 	 */
3072 	WARN_ON(options);
3073 
3074 	return serial_console_setup(co, early_serial_buf);
3075 }
3076 
3077 static struct console early_serial_console = {
3078 	.name           = "early_ttySC",
3079 	.write          = serial_console_write,
3080 	.setup		= early_serial_console_setup,
3081 	.flags          = CON_PRINTBUFFER,
3082 	.index		= -1,
3083 };
3084 
3085 static int sci_probe_earlyprintk(struct platform_device *pdev)
3086 {
3087 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3088 
3089 	if (early_serial_console.data)
3090 		return -EEXIST;
3091 
3092 	early_serial_console.index = pdev->id;
3093 
3094 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3095 
3096 	if (!strstr(early_serial_buf, "keep"))
3097 		early_serial_console.flags |= CON_BOOT;
3098 
3099 	register_console(&early_serial_console);
3100 	return 0;
3101 }
3102 #endif
3103 
3104 #define SCI_CONSOLE	(&serial_console)
3105 
3106 #else
3107 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3108 {
3109 	return -EINVAL;
3110 }
3111 
3112 #define SCI_CONSOLE	NULL
3113 
3114 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3115 
3116 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3117 
3118 static DEFINE_MUTEX(sci_uart_registration_lock);
3119 static struct uart_driver sci_uart_driver = {
3120 	.owner		= THIS_MODULE,
3121 	.driver_name	= "sci",
3122 	.dev_name	= "ttySC",
3123 	.major		= SCI_MAJOR,
3124 	.minor		= SCI_MINOR_START,
3125 	.nr		= SCI_NPORTS,
3126 	.cons		= SCI_CONSOLE,
3127 };
3128 
3129 static int sci_remove(struct platform_device *dev)
3130 {
3131 	struct sci_port *port = platform_get_drvdata(dev);
3132 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3133 
3134 	sci_ports_in_use &= ~BIT(port->port.line);
3135 	uart_remove_one_port(&sci_uart_driver, &port->port);
3136 
3137 	sci_cleanup_single(port);
3138 
3139 	if (port->port.fifosize > 1)
3140 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3141 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3142 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3143 
3144 	return 0;
3145 }
3146 
3147 
3148 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3149 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3150 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3151 
3152 static const struct of_device_id of_sci_match[] = {
3153 	/* SoC-specific types */
3154 	{
3155 		.compatible = "renesas,scif-r7s72100",
3156 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3157 	},
3158 	{
3159 		.compatible = "renesas,scif-r7s9210",
3160 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3161 	},
3162 	{
3163 		.compatible = "renesas,scif-r9a07g044",
3164 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3165 	},
3166 	/* Family-specific types */
3167 	{
3168 		.compatible = "renesas,rcar-gen1-scif",
3169 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3170 	}, {
3171 		.compatible = "renesas,rcar-gen2-scif",
3172 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3173 	}, {
3174 		.compatible = "renesas,rcar-gen3-scif",
3175 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3176 	}, {
3177 		.compatible = "renesas,rcar-gen4-scif",
3178 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3179 	},
3180 	/* Generic types */
3181 	{
3182 		.compatible = "renesas,scif",
3183 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3184 	}, {
3185 		.compatible = "renesas,scifa",
3186 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3187 	}, {
3188 		.compatible = "renesas,scifb",
3189 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3190 	}, {
3191 		.compatible = "renesas,hscif",
3192 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3193 	}, {
3194 		.compatible = "renesas,sci",
3195 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3196 	}, {
3197 		/* Terminator */
3198 	},
3199 };
3200 MODULE_DEVICE_TABLE(of, of_sci_match);
3201 
3202 static void sci_reset_control_assert(void *data)
3203 {
3204 	reset_control_assert(data);
3205 }
3206 
3207 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3208 					  unsigned int *dev_id)
3209 {
3210 	struct device_node *np = pdev->dev.of_node;
3211 	struct reset_control *rstc;
3212 	struct plat_sci_port *p;
3213 	struct sci_port *sp;
3214 	const void *data;
3215 	int id, ret;
3216 
3217 	if (!IS_ENABLED(CONFIG_OF) || !np)
3218 		return ERR_PTR(-EINVAL);
3219 
3220 	data = of_device_get_match_data(&pdev->dev);
3221 
3222 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3223 	if (IS_ERR(rstc))
3224 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3225 					     "failed to get reset ctrl\n"));
3226 
3227 	ret = reset_control_deassert(rstc);
3228 	if (ret) {
3229 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3230 		return ERR_PTR(ret);
3231 	}
3232 
3233 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3234 	if (ret) {
3235 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3236 			ret);
3237 		return ERR_PTR(ret);
3238 	}
3239 
3240 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3241 	if (!p)
3242 		return ERR_PTR(-ENOMEM);
3243 
3244 	/* Get the line number from the aliases node. */
3245 	id = of_alias_get_id(np, "serial");
3246 	if (id < 0 && ~sci_ports_in_use)
3247 		id = ffz(sci_ports_in_use);
3248 	if (id < 0) {
3249 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3250 		return ERR_PTR(-EINVAL);
3251 	}
3252 	if (id >= ARRAY_SIZE(sci_ports)) {
3253 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3254 		return ERR_PTR(-EINVAL);
3255 	}
3256 
3257 	sp = &sci_ports[id];
3258 	*dev_id = id;
3259 
3260 	p->type = SCI_OF_TYPE(data);
3261 	p->regtype = SCI_OF_REGTYPE(data);
3262 
3263 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3264 
3265 	return p;
3266 }
3267 
3268 static int sci_probe_single(struct platform_device *dev,
3269 				      unsigned int index,
3270 				      struct plat_sci_port *p,
3271 				      struct sci_port *sciport)
3272 {
3273 	int ret;
3274 
3275 	/* Sanity check */
3276 	if (unlikely(index >= SCI_NPORTS)) {
3277 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3278 			   index+1, SCI_NPORTS);
3279 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3280 		return -EINVAL;
3281 	}
3282 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3283 	if (sci_ports_in_use & BIT(index))
3284 		return -EBUSY;
3285 
3286 	mutex_lock(&sci_uart_registration_lock);
3287 	if (!sci_uart_driver.state) {
3288 		ret = uart_register_driver(&sci_uart_driver);
3289 		if (ret) {
3290 			mutex_unlock(&sci_uart_registration_lock);
3291 			return ret;
3292 		}
3293 	}
3294 	mutex_unlock(&sci_uart_registration_lock);
3295 
3296 	ret = sci_init_single(dev, sciport, index, p, false);
3297 	if (ret)
3298 		return ret;
3299 
3300 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3301 	if (IS_ERR(sciport->gpios))
3302 		return PTR_ERR(sciport->gpios);
3303 
3304 	if (sciport->has_rtscts) {
3305 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3306 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3307 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3308 			return -EINVAL;
3309 		}
3310 		sciport->port.flags |= UPF_HARD_FLOW;
3311 	}
3312 
3313 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3314 	if (ret) {
3315 		sci_cleanup_single(sciport);
3316 		return ret;
3317 	}
3318 
3319 	return 0;
3320 }
3321 
3322 static int sci_probe(struct platform_device *dev)
3323 {
3324 	struct plat_sci_port *p;
3325 	struct sci_port *sp;
3326 	unsigned int dev_id;
3327 	int ret;
3328 
3329 	/*
3330 	 * If we've come here via earlyprintk initialization, head off to
3331 	 * the special early probe. We don't have sufficient device state
3332 	 * to make it beyond this yet.
3333 	 */
3334 #ifdef CONFIG_SUPERH
3335 	if (is_sh_early_platform_device(dev))
3336 		return sci_probe_earlyprintk(dev);
3337 #endif
3338 
3339 	if (dev->dev.of_node) {
3340 		p = sci_parse_dt(dev, &dev_id);
3341 		if (IS_ERR(p))
3342 			return PTR_ERR(p);
3343 	} else {
3344 		p = dev->dev.platform_data;
3345 		if (p == NULL) {
3346 			dev_err(&dev->dev, "no platform data supplied\n");
3347 			return -EINVAL;
3348 		}
3349 
3350 		dev_id = dev->id;
3351 	}
3352 
3353 	sp = &sci_ports[dev_id];
3354 	platform_set_drvdata(dev, sp);
3355 
3356 	ret = sci_probe_single(dev, dev_id, p, sp);
3357 	if (ret)
3358 		return ret;
3359 
3360 	if (sp->port.fifosize > 1) {
3361 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3362 		if (ret)
3363 			return ret;
3364 	}
3365 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3366 	    sp->port.type == PORT_HSCIF) {
3367 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3368 		if (ret) {
3369 			if (sp->port.fifosize > 1) {
3370 				device_remove_file(&dev->dev,
3371 						   &dev_attr_rx_fifo_trigger);
3372 			}
3373 			return ret;
3374 		}
3375 	}
3376 
3377 #ifdef CONFIG_SH_STANDARD_BIOS
3378 	sh_bios_gdb_detach();
3379 #endif
3380 
3381 	sci_ports_in_use |= BIT(dev_id);
3382 	return 0;
3383 }
3384 
3385 static __maybe_unused int sci_suspend(struct device *dev)
3386 {
3387 	struct sci_port *sport = dev_get_drvdata(dev);
3388 
3389 	if (sport)
3390 		uart_suspend_port(&sci_uart_driver, &sport->port);
3391 
3392 	return 0;
3393 }
3394 
3395 static __maybe_unused int sci_resume(struct device *dev)
3396 {
3397 	struct sci_port *sport = dev_get_drvdata(dev);
3398 
3399 	if (sport)
3400 		uart_resume_port(&sci_uart_driver, &sport->port);
3401 
3402 	return 0;
3403 }
3404 
3405 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3406 
3407 static struct platform_driver sci_driver = {
3408 	.probe		= sci_probe,
3409 	.remove		= sci_remove,
3410 	.driver		= {
3411 		.name	= "sh-sci",
3412 		.pm	= &sci_dev_pm_ops,
3413 		.of_match_table = of_match_ptr(of_sci_match),
3414 	},
3415 };
3416 
3417 static int __init sci_init(void)
3418 {
3419 	pr_info("%s\n", banner);
3420 
3421 	return platform_driver_register(&sci_driver);
3422 }
3423 
3424 static void __exit sci_exit(void)
3425 {
3426 	platform_driver_unregister(&sci_driver);
3427 
3428 	if (sci_uart_driver.state)
3429 		uart_unregister_driver(&sci_uart_driver);
3430 }
3431 
3432 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3433 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3434 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3435 #endif
3436 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3437 static struct plat_sci_port port_cfg __initdata;
3438 
3439 static int __init early_console_setup(struct earlycon_device *device,
3440 				      int type)
3441 {
3442 	if (!device->port.membase)
3443 		return -ENODEV;
3444 
3445 	device->port.serial_in = sci_serial_in;
3446 	device->port.serial_out	= sci_serial_out;
3447 	device->port.type = type;
3448 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3449 	port_cfg.type = type;
3450 	sci_ports[0].cfg = &port_cfg;
3451 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3452 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3453 	sci_serial_out(&sci_ports[0].port, SCSCR,
3454 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3455 
3456 	device->con->write = serial_console_write;
3457 	return 0;
3458 }
3459 static int __init sci_early_console_setup(struct earlycon_device *device,
3460 					  const char *opt)
3461 {
3462 	return early_console_setup(device, PORT_SCI);
3463 }
3464 static int __init scif_early_console_setup(struct earlycon_device *device,
3465 					  const char *opt)
3466 {
3467 	return early_console_setup(device, PORT_SCIF);
3468 }
3469 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3470 					  const char *opt)
3471 {
3472 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3473 	return early_console_setup(device, PORT_SCIF);
3474 }
3475 
3476 static int __init scifa_early_console_setup(struct earlycon_device *device,
3477 					  const char *opt)
3478 {
3479 	return early_console_setup(device, PORT_SCIFA);
3480 }
3481 static int __init scifb_early_console_setup(struct earlycon_device *device,
3482 					  const char *opt)
3483 {
3484 	return early_console_setup(device, PORT_SCIFB);
3485 }
3486 static int __init hscif_early_console_setup(struct earlycon_device *device,
3487 					  const char *opt)
3488 {
3489 	return early_console_setup(device, PORT_HSCIF);
3490 }
3491 
3492 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3493 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3494 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3495 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3496 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3497 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3498 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3499 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3500 
3501 module_init(sci_init);
3502 module_exit(sci_exit);
3503 
3504 MODULE_LICENSE("GPL");
3505 MODULE_ALIAS("platform:sh-sci");
3506 MODULE_AUTHOR("Paul Mundt");
3507 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3508