xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision 7b73a9c8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 #define SUPPORT_SYSRQ
20 #endif
21 
22 #undef DEBUG
23 
24 #include <linux/clk.h>
25 #include <linux/console.h>
26 #include <linux/ctype.h>
27 #include <linux/cpufreq.h>
28 #include <linux/delay.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/err.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/ioport.h>
36 #include <linux/ktime.h>
37 #include <linux/major.h>
38 #include <linux/module.h>
39 #include <linux/mm.h>
40 #include <linux/of.h>
41 #include <linux/of_device.h>
42 #include <linux/platform_device.h>
43 #include <linux/pm_runtime.h>
44 #include <linux/scatterlist.h>
45 #include <linux/serial.h>
46 #include <linux/serial_sci.h>
47 #include <linux/sh_dma.h>
48 #include <linux/slab.h>
49 #include <linux/string.h>
50 #include <linux/sysrq.h>
51 #include <linux/timer.h>
52 #include <linux/tty.h>
53 #include <linux/tty_flip.h>
54 
55 #ifdef CONFIG_SUPERH
56 #include <asm/sh_bios.h>
57 #include <asm/platform_early.h>
58 #endif
59 
60 #include "serial_mctrl_gpio.h"
61 #include "sh-sci.h"
62 
63 /* Offsets into the sci_port->irqs array */
64 enum {
65 	SCIx_ERI_IRQ,
66 	SCIx_RXI_IRQ,
67 	SCIx_TXI_IRQ,
68 	SCIx_BRI_IRQ,
69 	SCIx_DRI_IRQ,
70 	SCIx_TEI_IRQ,
71 	SCIx_NR_IRQS,
72 
73 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
74 };
75 
76 #define SCIx_IRQ_IS_MUXED(port)			\
77 	((port)->irqs[SCIx_ERI_IRQ] ==	\
78 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
79 	((port)->irqs[SCIx_ERI_IRQ] &&	\
80 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
81 
82 enum SCI_CLKS {
83 	SCI_FCK,		/* Functional Clock */
84 	SCI_SCK,		/* Optional External Clock */
85 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
86 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
87 	SCI_NUM_CLKS
88 };
89 
90 /* Bit x set means sampling rate x + 1 is supported */
91 #define SCI_SR(x)		BIT((x) - 1)
92 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
93 
94 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
95 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
96 				SCI_SR(19) | SCI_SR(27)
97 
98 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
99 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
100 
101 /* Iterate over all supported sampling rates, from high to low */
102 #define for_each_sr(_sr, _port)						\
103 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
104 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
105 
106 struct plat_sci_reg {
107 	u8 offset, size;
108 };
109 
110 struct sci_port_params {
111 	const struct plat_sci_reg regs[SCIx_NR_REGS];
112 	unsigned int fifosize;
113 	unsigned int overrun_reg;
114 	unsigned int overrun_mask;
115 	unsigned int sampling_rate_mask;
116 	unsigned int error_mask;
117 	unsigned int error_clear;
118 };
119 
120 struct sci_port {
121 	struct uart_port	port;
122 
123 	/* Platform configuration */
124 	const struct sci_port_params *params;
125 	const struct plat_sci_port *cfg;
126 	unsigned int		sampling_rate_mask;
127 	resource_size_t		reg_size;
128 	struct mctrl_gpios	*gpios;
129 
130 	/* Clocks */
131 	struct clk		*clks[SCI_NUM_CLKS];
132 	unsigned long		clk_rates[SCI_NUM_CLKS];
133 
134 	int			irqs[SCIx_NR_IRQS];
135 	char			*irqstr[SCIx_NR_IRQS];
136 
137 	struct dma_chan			*chan_tx;
138 	struct dma_chan			*chan_rx;
139 
140 #ifdef CONFIG_SERIAL_SH_SCI_DMA
141 	struct dma_chan			*chan_tx_saved;
142 	struct dma_chan			*chan_rx_saved;
143 	dma_cookie_t			cookie_tx;
144 	dma_cookie_t			cookie_rx[2];
145 	dma_cookie_t			active_rx;
146 	dma_addr_t			tx_dma_addr;
147 	unsigned int			tx_dma_len;
148 	struct scatterlist		sg_rx[2];
149 	void				*rx_buf[2];
150 	size_t				buf_len_rx;
151 	struct work_struct		work_tx;
152 	struct hrtimer			rx_timer;
153 	unsigned int			rx_timeout;	/* microseconds */
154 #endif
155 	unsigned int			rx_frame;
156 	int				rx_trigger;
157 	struct timer_list		rx_fifo_timer;
158 	int				rx_fifo_timeout;
159 	u16				hscif_tot;
160 
161 	bool has_rtscts;
162 	bool autorts;
163 };
164 
165 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
166 
167 static struct sci_port sci_ports[SCI_NPORTS];
168 static unsigned long sci_ports_in_use;
169 static struct uart_driver sci_uart_driver;
170 
171 static inline struct sci_port *
172 to_sci_port(struct uart_port *uart)
173 {
174 	return container_of(uart, struct sci_port, port);
175 }
176 
177 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
178 	/*
179 	 * Common SCI definitions, dependent on the port's regshift
180 	 * value.
181 	 */
182 	[SCIx_SCI_REGTYPE] = {
183 		.regs = {
184 			[SCSMR]		= { 0x00,  8 },
185 			[SCBRR]		= { 0x01,  8 },
186 			[SCSCR]		= { 0x02,  8 },
187 			[SCxTDR]	= { 0x03,  8 },
188 			[SCxSR]		= { 0x04,  8 },
189 			[SCxRDR]	= { 0x05,  8 },
190 		},
191 		.fifosize = 1,
192 		.overrun_reg = SCxSR,
193 		.overrun_mask = SCI_ORER,
194 		.sampling_rate_mask = SCI_SR(32),
195 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
196 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
197 	},
198 
199 	/*
200 	 * Common definitions for legacy IrDA ports.
201 	 */
202 	[SCIx_IRDA_REGTYPE] = {
203 		.regs = {
204 			[SCSMR]		= { 0x00,  8 },
205 			[SCBRR]		= { 0x02,  8 },
206 			[SCSCR]		= { 0x04,  8 },
207 			[SCxTDR]	= { 0x06,  8 },
208 			[SCxSR]		= { 0x08, 16 },
209 			[SCxRDR]	= { 0x0a,  8 },
210 			[SCFCR]		= { 0x0c,  8 },
211 			[SCFDR]		= { 0x0e, 16 },
212 		},
213 		.fifosize = 1,
214 		.overrun_reg = SCxSR,
215 		.overrun_mask = SCI_ORER,
216 		.sampling_rate_mask = SCI_SR(32),
217 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
218 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
219 	},
220 
221 	/*
222 	 * Common SCIFA definitions.
223 	 */
224 	[SCIx_SCIFA_REGTYPE] = {
225 		.regs = {
226 			[SCSMR]		= { 0x00, 16 },
227 			[SCBRR]		= { 0x04,  8 },
228 			[SCSCR]		= { 0x08, 16 },
229 			[SCxTDR]	= { 0x20,  8 },
230 			[SCxSR]		= { 0x14, 16 },
231 			[SCxRDR]	= { 0x24,  8 },
232 			[SCFCR]		= { 0x18, 16 },
233 			[SCFDR]		= { 0x1c, 16 },
234 			[SCPCR]		= { 0x30, 16 },
235 			[SCPDR]		= { 0x34, 16 },
236 		},
237 		.fifosize = 64,
238 		.overrun_reg = SCxSR,
239 		.overrun_mask = SCIFA_ORER,
240 		.sampling_rate_mask = SCI_SR_SCIFAB,
241 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
242 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
243 	},
244 
245 	/*
246 	 * Common SCIFB definitions.
247 	 */
248 	[SCIx_SCIFB_REGTYPE] = {
249 		.regs = {
250 			[SCSMR]		= { 0x00, 16 },
251 			[SCBRR]		= { 0x04,  8 },
252 			[SCSCR]		= { 0x08, 16 },
253 			[SCxTDR]	= { 0x40,  8 },
254 			[SCxSR]		= { 0x14, 16 },
255 			[SCxRDR]	= { 0x60,  8 },
256 			[SCFCR]		= { 0x18, 16 },
257 			[SCTFDR]	= { 0x38, 16 },
258 			[SCRFDR]	= { 0x3c, 16 },
259 			[SCPCR]		= { 0x30, 16 },
260 			[SCPDR]		= { 0x34, 16 },
261 		},
262 		.fifosize = 256,
263 		.overrun_reg = SCxSR,
264 		.overrun_mask = SCIFA_ORER,
265 		.sampling_rate_mask = SCI_SR_SCIFAB,
266 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
267 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
268 	},
269 
270 	/*
271 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
272 	 * count registers.
273 	 */
274 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
275 		.regs = {
276 			[SCSMR]		= { 0x00, 16 },
277 			[SCBRR]		= { 0x04,  8 },
278 			[SCSCR]		= { 0x08, 16 },
279 			[SCxTDR]	= { 0x0c,  8 },
280 			[SCxSR]		= { 0x10, 16 },
281 			[SCxRDR]	= { 0x14,  8 },
282 			[SCFCR]		= { 0x18, 16 },
283 			[SCFDR]		= { 0x1c, 16 },
284 			[SCSPTR]	= { 0x20, 16 },
285 			[SCLSR]		= { 0x24, 16 },
286 		},
287 		.fifosize = 16,
288 		.overrun_reg = SCLSR,
289 		.overrun_mask = SCLSR_ORER,
290 		.sampling_rate_mask = SCI_SR(32),
291 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
292 		.error_clear = SCIF_ERROR_CLEAR,
293 	},
294 
295 	/*
296 	 * The "SCIFA" that is in RZ/T and RZ/A2.
297 	 * It looks like a normal SCIF with FIFO data, but with a
298 	 * compressed address space. Also, the break out of interrupts
299 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
300 	 */
301 	[SCIx_RZ_SCIFA_REGTYPE] = {
302 		.regs = {
303 			[SCSMR]		= { 0x00, 16 },
304 			[SCBRR]		= { 0x02,  8 },
305 			[SCSCR]		= { 0x04, 16 },
306 			[SCxTDR]	= { 0x06,  8 },
307 			[SCxSR]		= { 0x08, 16 },
308 			[SCxRDR]	= { 0x0A,  8 },
309 			[SCFCR]		= { 0x0C, 16 },
310 			[SCFDR]		= { 0x0E, 16 },
311 			[SCSPTR]	= { 0x10, 16 },
312 			[SCLSR]		= { 0x12, 16 },
313 		},
314 		.fifosize = 16,
315 		.overrun_reg = SCLSR,
316 		.overrun_mask = SCLSR_ORER,
317 		.sampling_rate_mask = SCI_SR(32),
318 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
319 		.error_clear = SCIF_ERROR_CLEAR,
320 	},
321 
322 	/*
323 	 * Common SH-3 SCIF definitions.
324 	 */
325 	[SCIx_SH3_SCIF_REGTYPE] = {
326 		.regs = {
327 			[SCSMR]		= { 0x00,  8 },
328 			[SCBRR]		= { 0x02,  8 },
329 			[SCSCR]		= { 0x04,  8 },
330 			[SCxTDR]	= { 0x06,  8 },
331 			[SCxSR]		= { 0x08, 16 },
332 			[SCxRDR]	= { 0x0a,  8 },
333 			[SCFCR]		= { 0x0c,  8 },
334 			[SCFDR]		= { 0x0e, 16 },
335 		},
336 		.fifosize = 16,
337 		.overrun_reg = SCLSR,
338 		.overrun_mask = SCLSR_ORER,
339 		.sampling_rate_mask = SCI_SR(32),
340 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
341 		.error_clear = SCIF_ERROR_CLEAR,
342 	},
343 
344 	/*
345 	 * Common SH-4(A) SCIF(B) definitions.
346 	 */
347 	[SCIx_SH4_SCIF_REGTYPE] = {
348 		.regs = {
349 			[SCSMR]		= { 0x00, 16 },
350 			[SCBRR]		= { 0x04,  8 },
351 			[SCSCR]		= { 0x08, 16 },
352 			[SCxTDR]	= { 0x0c,  8 },
353 			[SCxSR]		= { 0x10, 16 },
354 			[SCxRDR]	= { 0x14,  8 },
355 			[SCFCR]		= { 0x18, 16 },
356 			[SCFDR]		= { 0x1c, 16 },
357 			[SCSPTR]	= { 0x20, 16 },
358 			[SCLSR]		= { 0x24, 16 },
359 		},
360 		.fifosize = 16,
361 		.overrun_reg = SCLSR,
362 		.overrun_mask = SCLSR_ORER,
363 		.sampling_rate_mask = SCI_SR(32),
364 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
365 		.error_clear = SCIF_ERROR_CLEAR,
366 	},
367 
368 	/*
369 	 * Common SCIF definitions for ports with a Baud Rate Generator for
370 	 * External Clock (BRG).
371 	 */
372 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
373 		.regs = {
374 			[SCSMR]		= { 0x00, 16 },
375 			[SCBRR]		= { 0x04,  8 },
376 			[SCSCR]		= { 0x08, 16 },
377 			[SCxTDR]	= { 0x0c,  8 },
378 			[SCxSR]		= { 0x10, 16 },
379 			[SCxRDR]	= { 0x14,  8 },
380 			[SCFCR]		= { 0x18, 16 },
381 			[SCFDR]		= { 0x1c, 16 },
382 			[SCSPTR]	= { 0x20, 16 },
383 			[SCLSR]		= { 0x24, 16 },
384 			[SCDL]		= { 0x30, 16 },
385 			[SCCKS]		= { 0x34, 16 },
386 		},
387 		.fifosize = 16,
388 		.overrun_reg = SCLSR,
389 		.overrun_mask = SCLSR_ORER,
390 		.sampling_rate_mask = SCI_SR(32),
391 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
392 		.error_clear = SCIF_ERROR_CLEAR,
393 	},
394 
395 	/*
396 	 * Common HSCIF definitions.
397 	 */
398 	[SCIx_HSCIF_REGTYPE] = {
399 		.regs = {
400 			[SCSMR]		= { 0x00, 16 },
401 			[SCBRR]		= { 0x04,  8 },
402 			[SCSCR]		= { 0x08, 16 },
403 			[SCxTDR]	= { 0x0c,  8 },
404 			[SCxSR]		= { 0x10, 16 },
405 			[SCxRDR]	= { 0x14,  8 },
406 			[SCFCR]		= { 0x18, 16 },
407 			[SCFDR]		= { 0x1c, 16 },
408 			[SCSPTR]	= { 0x20, 16 },
409 			[SCLSR]		= { 0x24, 16 },
410 			[HSSRR]		= { 0x40, 16 },
411 			[SCDL]		= { 0x30, 16 },
412 			[SCCKS]		= { 0x34, 16 },
413 			[HSRTRGR]	= { 0x54, 16 },
414 			[HSTTRGR]	= { 0x58, 16 },
415 		},
416 		.fifosize = 128,
417 		.overrun_reg = SCLSR,
418 		.overrun_mask = SCLSR_ORER,
419 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
420 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
421 		.error_clear = SCIF_ERROR_CLEAR,
422 	},
423 
424 	/*
425 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
426 	 * register.
427 	 */
428 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
429 		.regs = {
430 			[SCSMR]		= { 0x00, 16 },
431 			[SCBRR]		= { 0x04,  8 },
432 			[SCSCR]		= { 0x08, 16 },
433 			[SCxTDR]	= { 0x0c,  8 },
434 			[SCxSR]		= { 0x10, 16 },
435 			[SCxRDR]	= { 0x14,  8 },
436 			[SCFCR]		= { 0x18, 16 },
437 			[SCFDR]		= { 0x1c, 16 },
438 			[SCLSR]		= { 0x24, 16 },
439 		},
440 		.fifosize = 16,
441 		.overrun_reg = SCLSR,
442 		.overrun_mask = SCLSR_ORER,
443 		.sampling_rate_mask = SCI_SR(32),
444 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
445 		.error_clear = SCIF_ERROR_CLEAR,
446 	},
447 
448 	/*
449 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
450 	 * count registers.
451 	 */
452 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
453 		.regs = {
454 			[SCSMR]		= { 0x00, 16 },
455 			[SCBRR]		= { 0x04,  8 },
456 			[SCSCR]		= { 0x08, 16 },
457 			[SCxTDR]	= { 0x0c,  8 },
458 			[SCxSR]		= { 0x10, 16 },
459 			[SCxRDR]	= { 0x14,  8 },
460 			[SCFCR]		= { 0x18, 16 },
461 			[SCFDR]		= { 0x1c, 16 },
462 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
463 			[SCRFDR]	= { 0x20, 16 },
464 			[SCSPTR]	= { 0x24, 16 },
465 			[SCLSR]		= { 0x28, 16 },
466 		},
467 		.fifosize = 16,
468 		.overrun_reg = SCLSR,
469 		.overrun_mask = SCLSR_ORER,
470 		.sampling_rate_mask = SCI_SR(32),
471 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
472 		.error_clear = SCIF_ERROR_CLEAR,
473 	},
474 
475 	/*
476 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
477 	 * registers.
478 	 */
479 	[SCIx_SH7705_SCIF_REGTYPE] = {
480 		.regs = {
481 			[SCSMR]		= { 0x00, 16 },
482 			[SCBRR]		= { 0x04,  8 },
483 			[SCSCR]		= { 0x08, 16 },
484 			[SCxTDR]	= { 0x20,  8 },
485 			[SCxSR]		= { 0x14, 16 },
486 			[SCxRDR]	= { 0x24,  8 },
487 			[SCFCR]		= { 0x18, 16 },
488 			[SCFDR]		= { 0x1c, 16 },
489 		},
490 		.fifosize = 64,
491 		.overrun_reg = SCxSR,
492 		.overrun_mask = SCIFA_ORER,
493 		.sampling_rate_mask = SCI_SR(16),
494 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
495 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
496 	},
497 };
498 
499 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
500 
501 /*
502  * The "offset" here is rather misleading, in that it refers to an enum
503  * value relative to the port mapping rather than the fixed offset
504  * itself, which needs to be manually retrieved from the platform's
505  * register map for the given port.
506  */
507 static unsigned int sci_serial_in(struct uart_port *p, int offset)
508 {
509 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
510 
511 	if (reg->size == 8)
512 		return ioread8(p->membase + (reg->offset << p->regshift));
513 	else if (reg->size == 16)
514 		return ioread16(p->membase + (reg->offset << p->regshift));
515 	else
516 		WARN(1, "Invalid register access\n");
517 
518 	return 0;
519 }
520 
521 static void sci_serial_out(struct uart_port *p, int offset, int value)
522 {
523 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
524 
525 	if (reg->size == 8)
526 		iowrite8(value, p->membase + (reg->offset << p->regshift));
527 	else if (reg->size == 16)
528 		iowrite16(value, p->membase + (reg->offset << p->regshift));
529 	else
530 		WARN(1, "Invalid register access\n");
531 }
532 
533 static void sci_port_enable(struct sci_port *sci_port)
534 {
535 	unsigned int i;
536 
537 	if (!sci_port->port.dev)
538 		return;
539 
540 	pm_runtime_get_sync(sci_port->port.dev);
541 
542 	for (i = 0; i < SCI_NUM_CLKS; i++) {
543 		clk_prepare_enable(sci_port->clks[i]);
544 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
545 	}
546 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
547 }
548 
549 static void sci_port_disable(struct sci_port *sci_port)
550 {
551 	unsigned int i;
552 
553 	if (!sci_port->port.dev)
554 		return;
555 
556 	for (i = SCI_NUM_CLKS; i-- > 0; )
557 		clk_disable_unprepare(sci_port->clks[i]);
558 
559 	pm_runtime_put_sync(sci_port->port.dev);
560 }
561 
562 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
563 {
564 	/*
565 	 * Not all ports (such as SCIFA) will support REIE. Rather than
566 	 * special-casing the port type, we check the port initialization
567 	 * IRQ enable mask to see whether the IRQ is desired at all. If
568 	 * it's unset, it's logically inferred that there's no point in
569 	 * testing for it.
570 	 */
571 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
572 }
573 
574 static void sci_start_tx(struct uart_port *port)
575 {
576 	struct sci_port *s = to_sci_port(port);
577 	unsigned short ctrl;
578 
579 #ifdef CONFIG_SERIAL_SH_SCI_DMA
580 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
581 		u16 new, scr = serial_port_in(port, SCSCR);
582 		if (s->chan_tx)
583 			new = scr | SCSCR_TDRQE;
584 		else
585 			new = scr & ~SCSCR_TDRQE;
586 		if (new != scr)
587 			serial_port_out(port, SCSCR, new);
588 	}
589 
590 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
591 	    dma_submit_error(s->cookie_tx)) {
592 		s->cookie_tx = 0;
593 		schedule_work(&s->work_tx);
594 	}
595 #endif
596 
597 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
598 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
599 		ctrl = serial_port_in(port, SCSCR);
600 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
601 	}
602 }
603 
604 static void sci_stop_tx(struct uart_port *port)
605 {
606 	unsigned short ctrl;
607 
608 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
609 	ctrl = serial_port_in(port, SCSCR);
610 
611 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
612 		ctrl &= ~SCSCR_TDRQE;
613 
614 	ctrl &= ~SCSCR_TIE;
615 
616 	serial_port_out(port, SCSCR, ctrl);
617 }
618 
619 static void sci_start_rx(struct uart_port *port)
620 {
621 	unsigned short ctrl;
622 
623 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
624 
625 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
626 		ctrl &= ~SCSCR_RDRQE;
627 
628 	serial_port_out(port, SCSCR, ctrl);
629 }
630 
631 static void sci_stop_rx(struct uart_port *port)
632 {
633 	unsigned short ctrl;
634 
635 	ctrl = serial_port_in(port, SCSCR);
636 
637 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
638 		ctrl &= ~SCSCR_RDRQE;
639 
640 	ctrl &= ~port_rx_irq_mask(port);
641 
642 	serial_port_out(port, SCSCR, ctrl);
643 }
644 
645 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
646 {
647 	if (port->type == PORT_SCI) {
648 		/* Just store the mask */
649 		serial_port_out(port, SCxSR, mask);
650 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
651 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
652 		/* Only clear the status bits we want to clear */
653 		serial_port_out(port, SCxSR,
654 				serial_port_in(port, SCxSR) & mask);
655 	} else {
656 		/* Store the mask, clear parity/framing errors */
657 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
658 	}
659 }
660 
661 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
662     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
663 
664 #ifdef CONFIG_CONSOLE_POLL
665 static int sci_poll_get_char(struct uart_port *port)
666 {
667 	unsigned short status;
668 	int c;
669 
670 	do {
671 		status = serial_port_in(port, SCxSR);
672 		if (status & SCxSR_ERRORS(port)) {
673 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
674 			continue;
675 		}
676 		break;
677 	} while (1);
678 
679 	if (!(status & SCxSR_RDxF(port)))
680 		return NO_POLL_CHAR;
681 
682 	c = serial_port_in(port, SCxRDR);
683 
684 	/* Dummy read */
685 	serial_port_in(port, SCxSR);
686 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
687 
688 	return c;
689 }
690 #endif
691 
692 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
693 {
694 	unsigned short status;
695 
696 	do {
697 		status = serial_port_in(port, SCxSR);
698 	} while (!(status & SCxSR_TDxE(port)));
699 
700 	serial_port_out(port, SCxTDR, c);
701 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
702 }
703 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
704 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
705 
706 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
707 {
708 	struct sci_port *s = to_sci_port(port);
709 
710 	/*
711 	 * Use port-specific handler if provided.
712 	 */
713 	if (s->cfg->ops && s->cfg->ops->init_pins) {
714 		s->cfg->ops->init_pins(port, cflag);
715 		return;
716 	}
717 
718 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
719 		u16 data = serial_port_in(port, SCPDR);
720 		u16 ctrl = serial_port_in(port, SCPCR);
721 
722 		/* Enable RXD and TXD pin functions */
723 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
724 		if (to_sci_port(port)->has_rtscts) {
725 			/* RTS# is output, active low, unless autorts */
726 			if (!(port->mctrl & TIOCM_RTS)) {
727 				ctrl |= SCPCR_RTSC;
728 				data |= SCPDR_RTSD;
729 			} else if (!s->autorts) {
730 				ctrl |= SCPCR_RTSC;
731 				data &= ~SCPDR_RTSD;
732 			} else {
733 				/* Enable RTS# pin function */
734 				ctrl &= ~SCPCR_RTSC;
735 			}
736 			/* Enable CTS# pin function */
737 			ctrl &= ~SCPCR_CTSC;
738 		}
739 		serial_port_out(port, SCPDR, data);
740 		serial_port_out(port, SCPCR, ctrl);
741 	} else if (sci_getreg(port, SCSPTR)->size) {
742 		u16 status = serial_port_in(port, SCSPTR);
743 
744 		/* RTS# is always output; and active low, unless autorts */
745 		status |= SCSPTR_RTSIO;
746 		if (!(port->mctrl & TIOCM_RTS))
747 			status |= SCSPTR_RTSDT;
748 		else if (!s->autorts)
749 			status &= ~SCSPTR_RTSDT;
750 		/* CTS# and SCK are inputs */
751 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
752 		serial_port_out(port, SCSPTR, status);
753 	}
754 }
755 
756 static int sci_txfill(struct uart_port *port)
757 {
758 	struct sci_port *s = to_sci_port(port);
759 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
760 	const struct plat_sci_reg *reg;
761 
762 	reg = sci_getreg(port, SCTFDR);
763 	if (reg->size)
764 		return serial_port_in(port, SCTFDR) & fifo_mask;
765 
766 	reg = sci_getreg(port, SCFDR);
767 	if (reg->size)
768 		return serial_port_in(port, SCFDR) >> 8;
769 
770 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
771 }
772 
773 static int sci_txroom(struct uart_port *port)
774 {
775 	return port->fifosize - sci_txfill(port);
776 }
777 
778 static int sci_rxfill(struct uart_port *port)
779 {
780 	struct sci_port *s = to_sci_port(port);
781 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
782 	const struct plat_sci_reg *reg;
783 
784 	reg = sci_getreg(port, SCRFDR);
785 	if (reg->size)
786 		return serial_port_in(port, SCRFDR) & fifo_mask;
787 
788 	reg = sci_getreg(port, SCFDR);
789 	if (reg->size)
790 		return serial_port_in(port, SCFDR) & fifo_mask;
791 
792 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
793 }
794 
795 /* ********************************************************************** *
796  *                   the interrupt related routines                       *
797  * ********************************************************************** */
798 
799 static void sci_transmit_chars(struct uart_port *port)
800 {
801 	struct circ_buf *xmit = &port->state->xmit;
802 	unsigned int stopped = uart_tx_stopped(port);
803 	unsigned short status;
804 	unsigned short ctrl;
805 	int count;
806 
807 	status = serial_port_in(port, SCxSR);
808 	if (!(status & SCxSR_TDxE(port))) {
809 		ctrl = serial_port_in(port, SCSCR);
810 		if (uart_circ_empty(xmit))
811 			ctrl &= ~SCSCR_TIE;
812 		else
813 			ctrl |= SCSCR_TIE;
814 		serial_port_out(port, SCSCR, ctrl);
815 		return;
816 	}
817 
818 	count = sci_txroom(port);
819 
820 	do {
821 		unsigned char c;
822 
823 		if (port->x_char) {
824 			c = port->x_char;
825 			port->x_char = 0;
826 		} else if (!uart_circ_empty(xmit) && !stopped) {
827 			c = xmit->buf[xmit->tail];
828 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
829 		} else {
830 			break;
831 		}
832 
833 		serial_port_out(port, SCxTDR, c);
834 
835 		port->icount.tx++;
836 	} while (--count > 0);
837 
838 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
839 
840 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
841 		uart_write_wakeup(port);
842 	if (uart_circ_empty(xmit))
843 		sci_stop_tx(port);
844 
845 }
846 
847 /* On SH3, SCIF may read end-of-break as a space->mark char */
848 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
849 
850 static void sci_receive_chars(struct uart_port *port)
851 {
852 	struct tty_port *tport = &port->state->port;
853 	int i, count, copied = 0;
854 	unsigned short status;
855 	unsigned char flag;
856 
857 	status = serial_port_in(port, SCxSR);
858 	if (!(status & SCxSR_RDxF(port)))
859 		return;
860 
861 	while (1) {
862 		/* Don't copy more bytes than there is room for in the buffer */
863 		count = tty_buffer_request_room(tport, sci_rxfill(port));
864 
865 		/* If for any reason we can't copy more data, we're done! */
866 		if (count == 0)
867 			break;
868 
869 		if (port->type == PORT_SCI) {
870 			char c = serial_port_in(port, SCxRDR);
871 			if (uart_handle_sysrq_char(port, c))
872 				count = 0;
873 			else
874 				tty_insert_flip_char(tport, c, TTY_NORMAL);
875 		} else {
876 			for (i = 0; i < count; i++) {
877 				char c = serial_port_in(port, SCxRDR);
878 
879 				status = serial_port_in(port, SCxSR);
880 				if (uart_handle_sysrq_char(port, c)) {
881 					count--; i--;
882 					continue;
883 				}
884 
885 				/* Store data and status */
886 				if (status & SCxSR_FER(port)) {
887 					flag = TTY_FRAME;
888 					port->icount.frame++;
889 					dev_notice(port->dev, "frame error\n");
890 				} else if (status & SCxSR_PER(port)) {
891 					flag = TTY_PARITY;
892 					port->icount.parity++;
893 					dev_notice(port->dev, "parity error\n");
894 				} else
895 					flag = TTY_NORMAL;
896 
897 				tty_insert_flip_char(tport, c, flag);
898 			}
899 		}
900 
901 		serial_port_in(port, SCxSR); /* dummy read */
902 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
903 
904 		copied += count;
905 		port->icount.rx += count;
906 	}
907 
908 	if (copied) {
909 		/* Tell the rest of the system the news. New characters! */
910 		tty_flip_buffer_push(tport);
911 	} else {
912 		/* TTY buffers full; read from RX reg to prevent lockup */
913 		serial_port_in(port, SCxRDR);
914 		serial_port_in(port, SCxSR); /* dummy read */
915 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
916 	}
917 }
918 
919 static int sci_handle_errors(struct uart_port *port)
920 {
921 	int copied = 0;
922 	unsigned short status = serial_port_in(port, SCxSR);
923 	struct tty_port *tport = &port->state->port;
924 	struct sci_port *s = to_sci_port(port);
925 
926 	/* Handle overruns */
927 	if (status & s->params->overrun_mask) {
928 		port->icount.overrun++;
929 
930 		/* overrun error */
931 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
932 			copied++;
933 
934 		dev_notice(port->dev, "overrun error\n");
935 	}
936 
937 	if (status & SCxSR_FER(port)) {
938 		/* frame error */
939 		port->icount.frame++;
940 
941 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
942 			copied++;
943 
944 		dev_notice(port->dev, "frame error\n");
945 	}
946 
947 	if (status & SCxSR_PER(port)) {
948 		/* parity error */
949 		port->icount.parity++;
950 
951 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
952 			copied++;
953 
954 		dev_notice(port->dev, "parity error\n");
955 	}
956 
957 	if (copied)
958 		tty_flip_buffer_push(tport);
959 
960 	return copied;
961 }
962 
963 static int sci_handle_fifo_overrun(struct uart_port *port)
964 {
965 	struct tty_port *tport = &port->state->port;
966 	struct sci_port *s = to_sci_port(port);
967 	const struct plat_sci_reg *reg;
968 	int copied = 0;
969 	u16 status;
970 
971 	reg = sci_getreg(port, s->params->overrun_reg);
972 	if (!reg->size)
973 		return 0;
974 
975 	status = serial_port_in(port, s->params->overrun_reg);
976 	if (status & s->params->overrun_mask) {
977 		status &= ~s->params->overrun_mask;
978 		serial_port_out(port, s->params->overrun_reg, status);
979 
980 		port->icount.overrun++;
981 
982 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
983 		tty_flip_buffer_push(tport);
984 
985 		dev_dbg(port->dev, "overrun error\n");
986 		copied++;
987 	}
988 
989 	return copied;
990 }
991 
992 static int sci_handle_breaks(struct uart_port *port)
993 {
994 	int copied = 0;
995 	unsigned short status = serial_port_in(port, SCxSR);
996 	struct tty_port *tport = &port->state->port;
997 
998 	if (uart_handle_break(port))
999 		return 0;
1000 
1001 	if (status & SCxSR_BRK(port)) {
1002 		port->icount.brk++;
1003 
1004 		/* Notify of BREAK */
1005 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1006 			copied++;
1007 
1008 		dev_dbg(port->dev, "BREAK detected\n");
1009 	}
1010 
1011 	if (copied)
1012 		tty_flip_buffer_push(tport);
1013 
1014 	copied += sci_handle_fifo_overrun(port);
1015 
1016 	return copied;
1017 }
1018 
1019 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1020 {
1021 	unsigned int bits;
1022 
1023 	if (rx_trig < 1)
1024 		rx_trig = 1;
1025 	if (rx_trig >= port->fifosize)
1026 		rx_trig = port->fifosize;
1027 
1028 	/* HSCIF can be set to an arbitrary level. */
1029 	if (sci_getreg(port, HSRTRGR)->size) {
1030 		serial_port_out(port, HSRTRGR, rx_trig);
1031 		return rx_trig;
1032 	}
1033 
1034 	switch (port->type) {
1035 	case PORT_SCIF:
1036 		if (rx_trig < 4) {
1037 			bits = 0;
1038 			rx_trig = 1;
1039 		} else if (rx_trig < 8) {
1040 			bits = SCFCR_RTRG0;
1041 			rx_trig = 4;
1042 		} else if (rx_trig < 14) {
1043 			bits = SCFCR_RTRG1;
1044 			rx_trig = 8;
1045 		} else {
1046 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1047 			rx_trig = 14;
1048 		}
1049 		break;
1050 	case PORT_SCIFA:
1051 	case PORT_SCIFB:
1052 		if (rx_trig < 16) {
1053 			bits = 0;
1054 			rx_trig = 1;
1055 		} else if (rx_trig < 32) {
1056 			bits = SCFCR_RTRG0;
1057 			rx_trig = 16;
1058 		} else if (rx_trig < 48) {
1059 			bits = SCFCR_RTRG1;
1060 			rx_trig = 32;
1061 		} else {
1062 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1063 			rx_trig = 48;
1064 		}
1065 		break;
1066 	default:
1067 		WARN(1, "unknown FIFO configuration");
1068 		return 1;
1069 	}
1070 
1071 	serial_port_out(port, SCFCR,
1072 		(serial_port_in(port, SCFCR) &
1073 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1074 
1075 	return rx_trig;
1076 }
1077 
1078 static int scif_rtrg_enabled(struct uart_port *port)
1079 {
1080 	if (sci_getreg(port, HSRTRGR)->size)
1081 		return serial_port_in(port, HSRTRGR) != 0;
1082 	else
1083 		return (serial_port_in(port, SCFCR) &
1084 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1085 }
1086 
1087 static void rx_fifo_timer_fn(struct timer_list *t)
1088 {
1089 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1090 	struct uart_port *port = &s->port;
1091 
1092 	dev_dbg(port->dev, "Rx timed out\n");
1093 	scif_set_rtrg(port, 1);
1094 }
1095 
1096 static ssize_t rx_fifo_trigger_show(struct device *dev,
1097 				    struct device_attribute *attr, char *buf)
1098 {
1099 	struct uart_port *port = dev_get_drvdata(dev);
1100 	struct sci_port *sci = to_sci_port(port);
1101 
1102 	return sprintf(buf, "%d\n", sci->rx_trigger);
1103 }
1104 
1105 static ssize_t rx_fifo_trigger_store(struct device *dev,
1106 				     struct device_attribute *attr,
1107 				     const char *buf, size_t count)
1108 {
1109 	struct uart_port *port = dev_get_drvdata(dev);
1110 	struct sci_port *sci = to_sci_port(port);
1111 	int ret;
1112 	long r;
1113 
1114 	ret = kstrtol(buf, 0, &r);
1115 	if (ret)
1116 		return ret;
1117 
1118 	sci->rx_trigger = scif_set_rtrg(port, r);
1119 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1120 		scif_set_rtrg(port, 1);
1121 
1122 	return count;
1123 }
1124 
1125 static DEVICE_ATTR_RW(rx_fifo_trigger);
1126 
1127 static ssize_t rx_fifo_timeout_show(struct device *dev,
1128 			       struct device_attribute *attr,
1129 			       char *buf)
1130 {
1131 	struct uart_port *port = dev_get_drvdata(dev);
1132 	struct sci_port *sci = to_sci_port(port);
1133 	int v;
1134 
1135 	if (port->type == PORT_HSCIF)
1136 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1137 	else
1138 		v = sci->rx_fifo_timeout;
1139 
1140 	return sprintf(buf, "%d\n", v);
1141 }
1142 
1143 static ssize_t rx_fifo_timeout_store(struct device *dev,
1144 				struct device_attribute *attr,
1145 				const char *buf,
1146 				size_t count)
1147 {
1148 	struct uart_port *port = dev_get_drvdata(dev);
1149 	struct sci_port *sci = to_sci_port(port);
1150 	int ret;
1151 	long r;
1152 
1153 	ret = kstrtol(buf, 0, &r);
1154 	if (ret)
1155 		return ret;
1156 
1157 	if (port->type == PORT_HSCIF) {
1158 		if (r < 0 || r > 3)
1159 			return -EINVAL;
1160 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1161 	} else {
1162 		sci->rx_fifo_timeout = r;
1163 		scif_set_rtrg(port, 1);
1164 		if (r > 0)
1165 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1166 	}
1167 
1168 	return count;
1169 }
1170 
1171 static DEVICE_ATTR_RW(rx_fifo_timeout);
1172 
1173 
1174 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1175 static void sci_dma_tx_complete(void *arg)
1176 {
1177 	struct sci_port *s = arg;
1178 	struct uart_port *port = &s->port;
1179 	struct circ_buf *xmit = &port->state->xmit;
1180 	unsigned long flags;
1181 
1182 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1183 
1184 	spin_lock_irqsave(&port->lock, flags);
1185 
1186 	xmit->tail += s->tx_dma_len;
1187 	xmit->tail &= UART_XMIT_SIZE - 1;
1188 
1189 	port->icount.tx += s->tx_dma_len;
1190 
1191 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1192 		uart_write_wakeup(port);
1193 
1194 	if (!uart_circ_empty(xmit)) {
1195 		s->cookie_tx = 0;
1196 		schedule_work(&s->work_tx);
1197 	} else {
1198 		s->cookie_tx = -EINVAL;
1199 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1200 			u16 ctrl = serial_port_in(port, SCSCR);
1201 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1202 		}
1203 	}
1204 
1205 	spin_unlock_irqrestore(&port->lock, flags);
1206 }
1207 
1208 /* Locking: called with port lock held */
1209 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1210 {
1211 	struct uart_port *port = &s->port;
1212 	struct tty_port *tport = &port->state->port;
1213 	int copied;
1214 
1215 	copied = tty_insert_flip_string(tport, buf, count);
1216 	if (copied < count)
1217 		port->icount.buf_overrun++;
1218 
1219 	port->icount.rx += copied;
1220 
1221 	return copied;
1222 }
1223 
1224 static int sci_dma_rx_find_active(struct sci_port *s)
1225 {
1226 	unsigned int i;
1227 
1228 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1229 		if (s->active_rx == s->cookie_rx[i])
1230 			return i;
1231 
1232 	return -1;
1233 }
1234 
1235 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1236 {
1237 	unsigned int i;
1238 
1239 	s->chan_rx = NULL;
1240 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1241 		s->cookie_rx[i] = -EINVAL;
1242 	s->active_rx = 0;
1243 }
1244 
1245 static void sci_dma_rx_release(struct sci_port *s)
1246 {
1247 	struct dma_chan *chan = s->chan_rx_saved;
1248 
1249 	s->chan_rx_saved = NULL;
1250 	sci_dma_rx_chan_invalidate(s);
1251 	dmaengine_terminate_sync(chan);
1252 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1253 			  sg_dma_address(&s->sg_rx[0]));
1254 	dma_release_channel(chan);
1255 }
1256 
1257 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1258 {
1259 	long sec = usec / 1000000;
1260 	long nsec = (usec % 1000000) * 1000;
1261 	ktime_t t = ktime_set(sec, nsec);
1262 
1263 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1264 }
1265 
1266 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1267 {
1268 	struct uart_port *port = &s->port;
1269 	u16 scr;
1270 
1271 	/* Direct new serial port interrupts back to CPU */
1272 	scr = serial_port_in(port, SCSCR);
1273 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1274 		scr &= ~SCSCR_RDRQE;
1275 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1276 	}
1277 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1278 }
1279 
1280 static void sci_dma_rx_complete(void *arg)
1281 {
1282 	struct sci_port *s = arg;
1283 	struct dma_chan *chan = s->chan_rx;
1284 	struct uart_port *port = &s->port;
1285 	struct dma_async_tx_descriptor *desc;
1286 	unsigned long flags;
1287 	int active, count = 0;
1288 
1289 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1290 		s->active_rx);
1291 
1292 	spin_lock_irqsave(&port->lock, flags);
1293 
1294 	active = sci_dma_rx_find_active(s);
1295 	if (active >= 0)
1296 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1297 
1298 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1299 
1300 	if (count)
1301 		tty_flip_buffer_push(&port->state->port);
1302 
1303 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1304 				       DMA_DEV_TO_MEM,
1305 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1306 	if (!desc)
1307 		goto fail;
1308 
1309 	desc->callback = sci_dma_rx_complete;
1310 	desc->callback_param = s;
1311 	s->cookie_rx[active] = dmaengine_submit(desc);
1312 	if (dma_submit_error(s->cookie_rx[active]))
1313 		goto fail;
1314 
1315 	s->active_rx = s->cookie_rx[!active];
1316 
1317 	dma_async_issue_pending(chan);
1318 
1319 	spin_unlock_irqrestore(&port->lock, flags);
1320 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1321 		__func__, s->cookie_rx[active], active, s->active_rx);
1322 	return;
1323 
1324 fail:
1325 	spin_unlock_irqrestore(&port->lock, flags);
1326 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1327 	/* Switch to PIO */
1328 	spin_lock_irqsave(&port->lock, flags);
1329 	dmaengine_terminate_async(chan);
1330 	sci_dma_rx_chan_invalidate(s);
1331 	sci_dma_rx_reenable_irq(s);
1332 	spin_unlock_irqrestore(&port->lock, flags);
1333 }
1334 
1335 static void sci_dma_tx_release(struct sci_port *s)
1336 {
1337 	struct dma_chan *chan = s->chan_tx_saved;
1338 
1339 	cancel_work_sync(&s->work_tx);
1340 	s->chan_tx_saved = s->chan_tx = NULL;
1341 	s->cookie_tx = -EINVAL;
1342 	dmaengine_terminate_sync(chan);
1343 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1344 			 DMA_TO_DEVICE);
1345 	dma_release_channel(chan);
1346 }
1347 
1348 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1349 {
1350 	struct dma_chan *chan = s->chan_rx;
1351 	struct uart_port *port = &s->port;
1352 	unsigned long flags;
1353 	int i;
1354 
1355 	for (i = 0; i < 2; i++) {
1356 		struct scatterlist *sg = &s->sg_rx[i];
1357 		struct dma_async_tx_descriptor *desc;
1358 
1359 		desc = dmaengine_prep_slave_sg(chan,
1360 			sg, 1, DMA_DEV_TO_MEM,
1361 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1362 		if (!desc)
1363 			goto fail;
1364 
1365 		desc->callback = sci_dma_rx_complete;
1366 		desc->callback_param = s;
1367 		s->cookie_rx[i] = dmaengine_submit(desc);
1368 		if (dma_submit_error(s->cookie_rx[i]))
1369 			goto fail;
1370 
1371 	}
1372 
1373 	s->active_rx = s->cookie_rx[0];
1374 
1375 	dma_async_issue_pending(chan);
1376 	return 0;
1377 
1378 fail:
1379 	/* Switch to PIO */
1380 	if (!port_lock_held)
1381 		spin_lock_irqsave(&port->lock, flags);
1382 	if (i)
1383 		dmaengine_terminate_async(chan);
1384 	sci_dma_rx_chan_invalidate(s);
1385 	sci_start_rx(port);
1386 	if (!port_lock_held)
1387 		spin_unlock_irqrestore(&port->lock, flags);
1388 	return -EAGAIN;
1389 }
1390 
1391 static void sci_dma_tx_work_fn(struct work_struct *work)
1392 {
1393 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1394 	struct dma_async_tx_descriptor *desc;
1395 	struct dma_chan *chan = s->chan_tx;
1396 	struct uart_port *port = &s->port;
1397 	struct circ_buf *xmit = &port->state->xmit;
1398 	unsigned long flags;
1399 	dma_addr_t buf;
1400 	int head, tail;
1401 
1402 	/*
1403 	 * DMA is idle now.
1404 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1405 	 * offsets and lengths. Since it is a circular buffer, we have to
1406 	 * transmit till the end, and then the rest. Take the port lock to get a
1407 	 * consistent xmit buffer state.
1408 	 */
1409 	spin_lock_irq(&port->lock);
1410 	head = xmit->head;
1411 	tail = xmit->tail;
1412 	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1413 	s->tx_dma_len = min_t(unsigned int,
1414 		CIRC_CNT(head, tail, UART_XMIT_SIZE),
1415 		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1416 	if (!s->tx_dma_len) {
1417 		/* Transmit buffer has been flushed */
1418 		spin_unlock_irq(&port->lock);
1419 		return;
1420 	}
1421 
1422 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1423 					   DMA_MEM_TO_DEV,
1424 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1425 	if (!desc) {
1426 		spin_unlock_irq(&port->lock);
1427 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1428 		goto switch_to_pio;
1429 	}
1430 
1431 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1432 				   DMA_TO_DEVICE);
1433 
1434 	desc->callback = sci_dma_tx_complete;
1435 	desc->callback_param = s;
1436 	s->cookie_tx = dmaengine_submit(desc);
1437 	if (dma_submit_error(s->cookie_tx)) {
1438 		spin_unlock_irq(&port->lock);
1439 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1440 		goto switch_to_pio;
1441 	}
1442 
1443 	spin_unlock_irq(&port->lock);
1444 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1445 		__func__, xmit->buf, tail, head, s->cookie_tx);
1446 
1447 	dma_async_issue_pending(chan);
1448 	return;
1449 
1450 switch_to_pio:
1451 	spin_lock_irqsave(&port->lock, flags);
1452 	s->chan_tx = NULL;
1453 	sci_start_tx(port);
1454 	spin_unlock_irqrestore(&port->lock, flags);
1455 	return;
1456 }
1457 
1458 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1459 {
1460 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1461 	struct dma_chan *chan = s->chan_rx;
1462 	struct uart_port *port = &s->port;
1463 	struct dma_tx_state state;
1464 	enum dma_status status;
1465 	unsigned long flags;
1466 	unsigned int read;
1467 	int active, count;
1468 
1469 	dev_dbg(port->dev, "DMA Rx timed out\n");
1470 
1471 	spin_lock_irqsave(&port->lock, flags);
1472 
1473 	active = sci_dma_rx_find_active(s);
1474 	if (active < 0) {
1475 		spin_unlock_irqrestore(&port->lock, flags);
1476 		return HRTIMER_NORESTART;
1477 	}
1478 
1479 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1480 	if (status == DMA_COMPLETE) {
1481 		spin_unlock_irqrestore(&port->lock, flags);
1482 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1483 			s->active_rx, active);
1484 
1485 		/* Let packet complete handler take care of the packet */
1486 		return HRTIMER_NORESTART;
1487 	}
1488 
1489 	dmaengine_pause(chan);
1490 
1491 	/*
1492 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1493 	 * data keeps on coming until transaction is complete so check
1494 	 * for DMA_COMPLETE again
1495 	 * Let packet complete handler take care of the packet
1496 	 */
1497 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1498 	if (status == DMA_COMPLETE) {
1499 		spin_unlock_irqrestore(&port->lock, flags);
1500 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1501 		return HRTIMER_NORESTART;
1502 	}
1503 
1504 	/* Handle incomplete DMA receive */
1505 	dmaengine_terminate_async(s->chan_rx);
1506 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1507 
1508 	if (read) {
1509 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1510 		if (count)
1511 			tty_flip_buffer_push(&port->state->port);
1512 	}
1513 
1514 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1515 		sci_dma_rx_submit(s, true);
1516 
1517 	sci_dma_rx_reenable_irq(s);
1518 
1519 	spin_unlock_irqrestore(&port->lock, flags);
1520 
1521 	return HRTIMER_NORESTART;
1522 }
1523 
1524 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1525 					     enum dma_transfer_direction dir)
1526 {
1527 	struct dma_chan *chan;
1528 	struct dma_slave_config cfg;
1529 	int ret;
1530 
1531 	chan = dma_request_slave_channel(port->dev,
1532 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1533 	if (!chan) {
1534 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1535 		return NULL;
1536 	}
1537 
1538 	memset(&cfg, 0, sizeof(cfg));
1539 	cfg.direction = dir;
1540 	if (dir == DMA_MEM_TO_DEV) {
1541 		cfg.dst_addr = port->mapbase +
1542 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1543 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1544 	} else {
1545 		cfg.src_addr = port->mapbase +
1546 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1547 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1548 	}
1549 
1550 	ret = dmaengine_slave_config(chan, &cfg);
1551 	if (ret) {
1552 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1553 		dma_release_channel(chan);
1554 		return NULL;
1555 	}
1556 
1557 	return chan;
1558 }
1559 
1560 static void sci_request_dma(struct uart_port *port)
1561 {
1562 	struct sci_port *s = to_sci_port(port);
1563 	struct dma_chan *chan;
1564 
1565 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1566 
1567 	/*
1568 	 * DMA on console may interfere with Kernel log messages which use
1569 	 * plain putchar(). So, simply don't use it with a console.
1570 	 */
1571 	if (uart_console(port))
1572 		return;
1573 
1574 	if (!port->dev->of_node)
1575 		return;
1576 
1577 	s->cookie_tx = -EINVAL;
1578 
1579 	/*
1580 	 * Don't request a dma channel if no channel was specified
1581 	 * in the device tree.
1582 	 */
1583 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1584 		return;
1585 
1586 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1587 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1588 	if (chan) {
1589 		/* UART circular tx buffer is an aligned page. */
1590 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1591 						port->state->xmit.buf,
1592 						UART_XMIT_SIZE,
1593 						DMA_TO_DEVICE);
1594 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1595 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1596 			dma_release_channel(chan);
1597 		} else {
1598 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1599 				__func__, UART_XMIT_SIZE,
1600 				port->state->xmit.buf, &s->tx_dma_addr);
1601 
1602 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1603 			s->chan_tx_saved = s->chan_tx = chan;
1604 		}
1605 	}
1606 
1607 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1608 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1609 	if (chan) {
1610 		unsigned int i;
1611 		dma_addr_t dma;
1612 		void *buf;
1613 
1614 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1615 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1616 					 &dma, GFP_KERNEL);
1617 		if (!buf) {
1618 			dev_warn(port->dev,
1619 				 "Failed to allocate Rx dma buffer, using PIO\n");
1620 			dma_release_channel(chan);
1621 			return;
1622 		}
1623 
1624 		for (i = 0; i < 2; i++) {
1625 			struct scatterlist *sg = &s->sg_rx[i];
1626 
1627 			sg_init_table(sg, 1);
1628 			s->rx_buf[i] = buf;
1629 			sg_dma_address(sg) = dma;
1630 			sg_dma_len(sg) = s->buf_len_rx;
1631 
1632 			buf += s->buf_len_rx;
1633 			dma += s->buf_len_rx;
1634 		}
1635 
1636 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1637 		s->rx_timer.function = sci_dma_rx_timer_fn;
1638 
1639 		s->chan_rx_saved = s->chan_rx = chan;
1640 
1641 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1642 			sci_dma_rx_submit(s, false);
1643 	}
1644 }
1645 
1646 static void sci_free_dma(struct uart_port *port)
1647 {
1648 	struct sci_port *s = to_sci_port(port);
1649 
1650 	if (s->chan_tx_saved)
1651 		sci_dma_tx_release(s);
1652 	if (s->chan_rx_saved)
1653 		sci_dma_rx_release(s);
1654 }
1655 
1656 static void sci_flush_buffer(struct uart_port *port)
1657 {
1658 	struct sci_port *s = to_sci_port(port);
1659 
1660 	/*
1661 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1662 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1663 	 * pending transfers
1664 	 */
1665 	s->tx_dma_len = 0;
1666 	if (s->chan_tx) {
1667 		dmaengine_terminate_async(s->chan_tx);
1668 		s->cookie_tx = -EINVAL;
1669 	}
1670 }
1671 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1672 static inline void sci_request_dma(struct uart_port *port)
1673 {
1674 }
1675 
1676 static inline void sci_free_dma(struct uart_port *port)
1677 {
1678 }
1679 
1680 #define sci_flush_buffer	NULL
1681 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1682 
1683 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1684 {
1685 	struct uart_port *port = ptr;
1686 	struct sci_port *s = to_sci_port(port);
1687 
1688 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1689 	if (s->chan_rx) {
1690 		u16 scr = serial_port_in(port, SCSCR);
1691 		u16 ssr = serial_port_in(port, SCxSR);
1692 
1693 		/* Disable future Rx interrupts */
1694 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1695 			disable_irq_nosync(irq);
1696 			scr |= SCSCR_RDRQE;
1697 		} else {
1698 			if (sci_dma_rx_submit(s, false) < 0)
1699 				goto handle_pio;
1700 
1701 			scr &= ~SCSCR_RIE;
1702 		}
1703 		serial_port_out(port, SCSCR, scr);
1704 		/* Clear current interrupt */
1705 		serial_port_out(port, SCxSR,
1706 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1707 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1708 			jiffies, s->rx_timeout);
1709 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1710 
1711 		return IRQ_HANDLED;
1712 	}
1713 
1714 handle_pio:
1715 #endif
1716 
1717 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1718 		if (!scif_rtrg_enabled(port))
1719 			scif_set_rtrg(port, s->rx_trigger);
1720 
1721 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1722 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1723 	}
1724 
1725 	/* I think sci_receive_chars has to be called irrespective
1726 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1727 	 * to be disabled?
1728 	 */
1729 	sci_receive_chars(port);
1730 
1731 	return IRQ_HANDLED;
1732 }
1733 
1734 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1735 {
1736 	struct uart_port *port = ptr;
1737 	unsigned long flags;
1738 
1739 	spin_lock_irqsave(&port->lock, flags);
1740 	sci_transmit_chars(port);
1741 	spin_unlock_irqrestore(&port->lock, flags);
1742 
1743 	return IRQ_HANDLED;
1744 }
1745 
1746 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1747 {
1748 	struct uart_port *port = ptr;
1749 
1750 	/* Handle BREAKs */
1751 	sci_handle_breaks(port);
1752 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1753 
1754 	return IRQ_HANDLED;
1755 }
1756 
1757 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1758 {
1759 	struct uart_port *port = ptr;
1760 	struct sci_port *s = to_sci_port(port);
1761 
1762 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1763 		/* Break and Error interrupts are muxed */
1764 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1765 
1766 		/* Break Interrupt */
1767 		if (ssr_status & SCxSR_BRK(port))
1768 			sci_br_interrupt(irq, ptr);
1769 
1770 		/* Break only? */
1771 		if (!(ssr_status & SCxSR_ERRORS(port)))
1772 			return IRQ_HANDLED;
1773 	}
1774 
1775 	/* Handle errors */
1776 	if (port->type == PORT_SCI) {
1777 		if (sci_handle_errors(port)) {
1778 			/* discard character in rx buffer */
1779 			serial_port_in(port, SCxSR);
1780 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1781 		}
1782 	} else {
1783 		sci_handle_fifo_overrun(port);
1784 		if (!s->chan_rx)
1785 			sci_receive_chars(port);
1786 	}
1787 
1788 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1789 
1790 	/* Kick the transmission */
1791 	if (!s->chan_tx)
1792 		sci_tx_interrupt(irq, ptr);
1793 
1794 	return IRQ_HANDLED;
1795 }
1796 
1797 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1798 {
1799 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1800 	struct uart_port *port = ptr;
1801 	struct sci_port *s = to_sci_port(port);
1802 	irqreturn_t ret = IRQ_NONE;
1803 
1804 	ssr_status = serial_port_in(port, SCxSR);
1805 	scr_status = serial_port_in(port, SCSCR);
1806 	if (s->params->overrun_reg == SCxSR)
1807 		orer_status = ssr_status;
1808 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1809 		orer_status = serial_port_in(port, s->params->overrun_reg);
1810 
1811 	err_enabled = scr_status & port_rx_irq_mask(port);
1812 
1813 	/* Tx Interrupt */
1814 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1815 	    !s->chan_tx)
1816 		ret = sci_tx_interrupt(irq, ptr);
1817 
1818 	/*
1819 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1820 	 * DR flags
1821 	 */
1822 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1823 	    (scr_status & SCSCR_RIE))
1824 		ret = sci_rx_interrupt(irq, ptr);
1825 
1826 	/* Error Interrupt */
1827 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1828 		ret = sci_er_interrupt(irq, ptr);
1829 
1830 	/* Break Interrupt */
1831 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1832 		ret = sci_br_interrupt(irq, ptr);
1833 
1834 	/* Overrun Interrupt */
1835 	if (orer_status & s->params->overrun_mask) {
1836 		sci_handle_fifo_overrun(port);
1837 		ret = IRQ_HANDLED;
1838 	}
1839 
1840 	return ret;
1841 }
1842 
1843 static const struct sci_irq_desc {
1844 	const char	*desc;
1845 	irq_handler_t	handler;
1846 } sci_irq_desc[] = {
1847 	/*
1848 	 * Split out handlers, the default case.
1849 	 */
1850 	[SCIx_ERI_IRQ] = {
1851 		.desc = "rx err",
1852 		.handler = sci_er_interrupt,
1853 	},
1854 
1855 	[SCIx_RXI_IRQ] = {
1856 		.desc = "rx full",
1857 		.handler = sci_rx_interrupt,
1858 	},
1859 
1860 	[SCIx_TXI_IRQ] = {
1861 		.desc = "tx empty",
1862 		.handler = sci_tx_interrupt,
1863 	},
1864 
1865 	[SCIx_BRI_IRQ] = {
1866 		.desc = "break",
1867 		.handler = sci_br_interrupt,
1868 	},
1869 
1870 	[SCIx_DRI_IRQ] = {
1871 		.desc = "rx ready",
1872 		.handler = sci_rx_interrupt,
1873 	},
1874 
1875 	[SCIx_TEI_IRQ] = {
1876 		.desc = "tx end",
1877 		.handler = sci_tx_interrupt,
1878 	},
1879 
1880 	/*
1881 	 * Special muxed handler.
1882 	 */
1883 	[SCIx_MUX_IRQ] = {
1884 		.desc = "mux",
1885 		.handler = sci_mpxed_interrupt,
1886 	},
1887 };
1888 
1889 static int sci_request_irq(struct sci_port *port)
1890 {
1891 	struct uart_port *up = &port->port;
1892 	int i, j, w, ret = 0;
1893 
1894 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1895 		const struct sci_irq_desc *desc;
1896 		int irq;
1897 
1898 		/* Check if already registered (muxed) */
1899 		for (w = 0; w < i; w++)
1900 			if (port->irqs[w] == port->irqs[i])
1901 				w = i + 1;
1902 		if (w > i)
1903 			continue;
1904 
1905 		if (SCIx_IRQ_IS_MUXED(port)) {
1906 			i = SCIx_MUX_IRQ;
1907 			irq = up->irq;
1908 		} else {
1909 			irq = port->irqs[i];
1910 
1911 			/*
1912 			 * Certain port types won't support all of the
1913 			 * available interrupt sources.
1914 			 */
1915 			if (unlikely(irq < 0))
1916 				continue;
1917 		}
1918 
1919 		desc = sci_irq_desc + i;
1920 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1921 					    dev_name(up->dev), desc->desc);
1922 		if (!port->irqstr[j]) {
1923 			ret = -ENOMEM;
1924 			goto out_nomem;
1925 		}
1926 
1927 		ret = request_irq(irq, desc->handler, up->irqflags,
1928 				  port->irqstr[j], port);
1929 		if (unlikely(ret)) {
1930 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1931 			goto out_noirq;
1932 		}
1933 	}
1934 
1935 	return 0;
1936 
1937 out_noirq:
1938 	while (--i >= 0)
1939 		free_irq(port->irqs[i], port);
1940 
1941 out_nomem:
1942 	while (--j >= 0)
1943 		kfree(port->irqstr[j]);
1944 
1945 	return ret;
1946 }
1947 
1948 static void sci_free_irq(struct sci_port *port)
1949 {
1950 	int i, j;
1951 
1952 	/*
1953 	 * Intentionally in reverse order so we iterate over the muxed
1954 	 * IRQ first.
1955 	 */
1956 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1957 		int irq = port->irqs[i];
1958 
1959 		/*
1960 		 * Certain port types won't support all of the available
1961 		 * interrupt sources.
1962 		 */
1963 		if (unlikely(irq < 0))
1964 			continue;
1965 
1966 		/* Check if already freed (irq was muxed) */
1967 		for (j = 0; j < i; j++)
1968 			if (port->irqs[j] == irq)
1969 				j = i + 1;
1970 		if (j > i)
1971 			continue;
1972 
1973 		free_irq(port->irqs[i], port);
1974 		kfree(port->irqstr[i]);
1975 
1976 		if (SCIx_IRQ_IS_MUXED(port)) {
1977 			/* If there's only one IRQ, we're done. */
1978 			return;
1979 		}
1980 	}
1981 }
1982 
1983 static unsigned int sci_tx_empty(struct uart_port *port)
1984 {
1985 	unsigned short status = serial_port_in(port, SCxSR);
1986 	unsigned short in_tx_fifo = sci_txfill(port);
1987 
1988 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1989 }
1990 
1991 static void sci_set_rts(struct uart_port *port, bool state)
1992 {
1993 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1994 		u16 data = serial_port_in(port, SCPDR);
1995 
1996 		/* Active low */
1997 		if (state)
1998 			data &= ~SCPDR_RTSD;
1999 		else
2000 			data |= SCPDR_RTSD;
2001 		serial_port_out(port, SCPDR, data);
2002 
2003 		/* RTS# is output */
2004 		serial_port_out(port, SCPCR,
2005 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2006 	} else if (sci_getreg(port, SCSPTR)->size) {
2007 		u16 ctrl = serial_port_in(port, SCSPTR);
2008 
2009 		/* Active low */
2010 		if (state)
2011 			ctrl &= ~SCSPTR_RTSDT;
2012 		else
2013 			ctrl |= SCSPTR_RTSDT;
2014 		serial_port_out(port, SCSPTR, ctrl);
2015 	}
2016 }
2017 
2018 static bool sci_get_cts(struct uart_port *port)
2019 {
2020 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2021 		/* Active low */
2022 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2023 	} else if (sci_getreg(port, SCSPTR)->size) {
2024 		/* Active low */
2025 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2026 	}
2027 
2028 	return true;
2029 }
2030 
2031 /*
2032  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2033  * CTS/RTS is supported in hardware by at least one port and controlled
2034  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2035  * handled via the ->init_pins() op, which is a bit of a one-way street,
2036  * lacking any ability to defer pin control -- this will later be
2037  * converted over to the GPIO framework).
2038  *
2039  * Other modes (such as loopback) are supported generically on certain
2040  * port types, but not others. For these it's sufficient to test for the
2041  * existence of the support register and simply ignore the port type.
2042  */
2043 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2044 {
2045 	struct sci_port *s = to_sci_port(port);
2046 
2047 	if (mctrl & TIOCM_LOOP) {
2048 		const struct plat_sci_reg *reg;
2049 
2050 		/*
2051 		 * Standard loopback mode for SCFCR ports.
2052 		 */
2053 		reg = sci_getreg(port, SCFCR);
2054 		if (reg->size)
2055 			serial_port_out(port, SCFCR,
2056 					serial_port_in(port, SCFCR) |
2057 					SCFCR_LOOP);
2058 	}
2059 
2060 	mctrl_gpio_set(s->gpios, mctrl);
2061 
2062 	if (!s->has_rtscts)
2063 		return;
2064 
2065 	if (!(mctrl & TIOCM_RTS)) {
2066 		/* Disable Auto RTS */
2067 		serial_port_out(port, SCFCR,
2068 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2069 
2070 		/* Clear RTS */
2071 		sci_set_rts(port, 0);
2072 	} else if (s->autorts) {
2073 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2074 			/* Enable RTS# pin function */
2075 			serial_port_out(port, SCPCR,
2076 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2077 		}
2078 
2079 		/* Enable Auto RTS */
2080 		serial_port_out(port, SCFCR,
2081 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2082 	} else {
2083 		/* Set RTS */
2084 		sci_set_rts(port, 1);
2085 	}
2086 }
2087 
2088 static unsigned int sci_get_mctrl(struct uart_port *port)
2089 {
2090 	struct sci_port *s = to_sci_port(port);
2091 	struct mctrl_gpios *gpios = s->gpios;
2092 	unsigned int mctrl = 0;
2093 
2094 	mctrl_gpio_get(gpios, &mctrl);
2095 
2096 	/*
2097 	 * CTS/RTS is handled in hardware when supported, while nothing
2098 	 * else is wired up.
2099 	 */
2100 	if (s->autorts) {
2101 		if (sci_get_cts(port))
2102 			mctrl |= TIOCM_CTS;
2103 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2104 		mctrl |= TIOCM_CTS;
2105 	}
2106 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2107 		mctrl |= TIOCM_DSR;
2108 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2109 		mctrl |= TIOCM_CAR;
2110 
2111 	return mctrl;
2112 }
2113 
2114 static void sci_enable_ms(struct uart_port *port)
2115 {
2116 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2117 }
2118 
2119 static void sci_break_ctl(struct uart_port *port, int break_state)
2120 {
2121 	unsigned short scscr, scsptr;
2122 	unsigned long flags;
2123 
2124 	/* check wheter the port has SCSPTR */
2125 	if (!sci_getreg(port, SCSPTR)->size) {
2126 		/*
2127 		 * Not supported by hardware. Most parts couple break and rx
2128 		 * interrupts together, with break detection always enabled.
2129 		 */
2130 		return;
2131 	}
2132 
2133 	spin_lock_irqsave(&port->lock, flags);
2134 	scsptr = serial_port_in(port, SCSPTR);
2135 	scscr = serial_port_in(port, SCSCR);
2136 
2137 	if (break_state == -1) {
2138 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2139 		scscr &= ~SCSCR_TE;
2140 	} else {
2141 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2142 		scscr |= SCSCR_TE;
2143 	}
2144 
2145 	serial_port_out(port, SCSPTR, scsptr);
2146 	serial_port_out(port, SCSCR, scscr);
2147 	spin_unlock_irqrestore(&port->lock, flags);
2148 }
2149 
2150 static int sci_startup(struct uart_port *port)
2151 {
2152 	struct sci_port *s = to_sci_port(port);
2153 	int ret;
2154 
2155 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2156 
2157 	sci_request_dma(port);
2158 
2159 	ret = sci_request_irq(s);
2160 	if (unlikely(ret < 0)) {
2161 		sci_free_dma(port);
2162 		return ret;
2163 	}
2164 
2165 	return 0;
2166 }
2167 
2168 static void sci_shutdown(struct uart_port *port)
2169 {
2170 	struct sci_port *s = to_sci_port(port);
2171 	unsigned long flags;
2172 	u16 scr;
2173 
2174 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2175 
2176 	s->autorts = false;
2177 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2178 
2179 	spin_lock_irqsave(&port->lock, flags);
2180 	sci_stop_rx(port);
2181 	sci_stop_tx(port);
2182 	/*
2183 	 * Stop RX and TX, disable related interrupts, keep clock source
2184 	 * and HSCIF TOT bits
2185 	 */
2186 	scr = serial_port_in(port, SCSCR);
2187 	serial_port_out(port, SCSCR, scr &
2188 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2189 	spin_unlock_irqrestore(&port->lock, flags);
2190 
2191 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2192 	if (s->chan_rx_saved) {
2193 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2194 			port->line);
2195 		hrtimer_cancel(&s->rx_timer);
2196 	}
2197 #endif
2198 
2199 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2200 		del_timer_sync(&s->rx_fifo_timer);
2201 	sci_free_irq(s);
2202 	sci_free_dma(port);
2203 }
2204 
2205 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2206 			unsigned int *srr)
2207 {
2208 	unsigned long freq = s->clk_rates[SCI_SCK];
2209 	int err, min_err = INT_MAX;
2210 	unsigned int sr;
2211 
2212 	if (s->port.type != PORT_HSCIF)
2213 		freq *= 2;
2214 
2215 	for_each_sr(sr, s) {
2216 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2217 		if (abs(err) >= abs(min_err))
2218 			continue;
2219 
2220 		min_err = err;
2221 		*srr = sr - 1;
2222 
2223 		if (!err)
2224 			break;
2225 	}
2226 
2227 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2228 		*srr + 1);
2229 	return min_err;
2230 }
2231 
2232 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2233 			unsigned long freq, unsigned int *dlr,
2234 			unsigned int *srr)
2235 {
2236 	int err, min_err = INT_MAX;
2237 	unsigned int sr, dl;
2238 
2239 	if (s->port.type != PORT_HSCIF)
2240 		freq *= 2;
2241 
2242 	for_each_sr(sr, s) {
2243 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2244 		dl = clamp(dl, 1U, 65535U);
2245 
2246 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2247 		if (abs(err) >= abs(min_err))
2248 			continue;
2249 
2250 		min_err = err;
2251 		*dlr = dl;
2252 		*srr = sr - 1;
2253 
2254 		if (!err)
2255 			break;
2256 	}
2257 
2258 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2259 		min_err, *dlr, *srr + 1);
2260 	return min_err;
2261 }
2262 
2263 /* calculate sample rate, BRR, and clock select */
2264 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2265 			  unsigned int *brr, unsigned int *srr,
2266 			  unsigned int *cks)
2267 {
2268 	unsigned long freq = s->clk_rates[SCI_FCK];
2269 	unsigned int sr, br, prediv, scrate, c;
2270 	int err, min_err = INT_MAX;
2271 
2272 	if (s->port.type != PORT_HSCIF)
2273 		freq *= 2;
2274 
2275 	/*
2276 	 * Find the combination of sample rate and clock select with the
2277 	 * smallest deviation from the desired baud rate.
2278 	 * Prefer high sample rates to maximise the receive margin.
2279 	 *
2280 	 * M: Receive margin (%)
2281 	 * N: Ratio of bit rate to clock (N = sampling rate)
2282 	 * D: Clock duty (D = 0 to 1.0)
2283 	 * L: Frame length (L = 9 to 12)
2284 	 * F: Absolute value of clock frequency deviation
2285 	 *
2286 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2287 	 *      (|D - 0.5| / N * (1 + F))|
2288 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2289 	 */
2290 	for_each_sr(sr, s) {
2291 		for (c = 0; c <= 3; c++) {
2292 			/* integerized formulas from HSCIF documentation */
2293 			prediv = sr * (1 << (2 * c + 1));
2294 
2295 			/*
2296 			 * We need to calculate:
2297 			 *
2298 			 *     br = freq / (prediv * bps) clamped to [1..256]
2299 			 *     err = freq / (br * prediv) - bps
2300 			 *
2301 			 * Watch out for overflow when calculating the desired
2302 			 * sampling clock rate!
2303 			 */
2304 			if (bps > UINT_MAX / prediv)
2305 				break;
2306 
2307 			scrate = prediv * bps;
2308 			br = DIV_ROUND_CLOSEST(freq, scrate);
2309 			br = clamp(br, 1U, 256U);
2310 
2311 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2312 			if (abs(err) >= abs(min_err))
2313 				continue;
2314 
2315 			min_err = err;
2316 			*brr = br - 1;
2317 			*srr = sr - 1;
2318 			*cks = c;
2319 
2320 			if (!err)
2321 				goto found;
2322 		}
2323 	}
2324 
2325 found:
2326 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2327 		min_err, *brr, *srr + 1, *cks);
2328 	return min_err;
2329 }
2330 
2331 static void sci_reset(struct uart_port *port)
2332 {
2333 	const struct plat_sci_reg *reg;
2334 	unsigned int status;
2335 	struct sci_port *s = to_sci_port(port);
2336 
2337 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2338 
2339 	reg = sci_getreg(port, SCFCR);
2340 	if (reg->size)
2341 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2342 
2343 	sci_clear_SCxSR(port,
2344 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2345 			SCxSR_BREAK_CLEAR(port));
2346 	if (sci_getreg(port, SCLSR)->size) {
2347 		status = serial_port_in(port, SCLSR);
2348 		status &= ~(SCLSR_TO | SCLSR_ORER);
2349 		serial_port_out(port, SCLSR, status);
2350 	}
2351 
2352 	if (s->rx_trigger > 1) {
2353 		if (s->rx_fifo_timeout) {
2354 			scif_set_rtrg(port, 1);
2355 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2356 		} else {
2357 			if (port->type == PORT_SCIFA ||
2358 			    port->type == PORT_SCIFB)
2359 				scif_set_rtrg(port, 1);
2360 			else
2361 				scif_set_rtrg(port, s->rx_trigger);
2362 		}
2363 	}
2364 }
2365 
2366 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2367 			    struct ktermios *old)
2368 {
2369 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2370 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2371 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2372 	struct sci_port *s = to_sci_port(port);
2373 	const struct plat_sci_reg *reg;
2374 	int min_err = INT_MAX, err;
2375 	unsigned long max_freq = 0;
2376 	int best_clk = -1;
2377 	unsigned long flags;
2378 
2379 	if ((termios->c_cflag & CSIZE) == CS7)
2380 		smr_val |= SCSMR_CHR;
2381 	if (termios->c_cflag & PARENB)
2382 		smr_val |= SCSMR_PE;
2383 	if (termios->c_cflag & PARODD)
2384 		smr_val |= SCSMR_PE | SCSMR_ODD;
2385 	if (termios->c_cflag & CSTOPB)
2386 		smr_val |= SCSMR_STOP;
2387 
2388 	/*
2389 	 * earlyprintk comes here early on with port->uartclk set to zero.
2390 	 * the clock framework is not up and running at this point so here
2391 	 * we assume that 115200 is the maximum baud rate. please note that
2392 	 * the baud rate is not programmed during earlyprintk - it is assumed
2393 	 * that the previous boot loader has enabled required clocks and
2394 	 * setup the baud rate generator hardware for us already.
2395 	 */
2396 	if (!port->uartclk) {
2397 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2398 		goto done;
2399 	}
2400 
2401 	for (i = 0; i < SCI_NUM_CLKS; i++)
2402 		max_freq = max(max_freq, s->clk_rates[i]);
2403 
2404 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2405 	if (!baud)
2406 		goto done;
2407 
2408 	/*
2409 	 * There can be multiple sources for the sampling clock.  Find the one
2410 	 * that gives us the smallest deviation from the desired baud rate.
2411 	 */
2412 
2413 	/* Optional Undivided External Clock */
2414 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2415 	    port->type != PORT_SCIFB) {
2416 		err = sci_sck_calc(s, baud, &srr1);
2417 		if (abs(err) < abs(min_err)) {
2418 			best_clk = SCI_SCK;
2419 			scr_val = SCSCR_CKE1;
2420 			sccks = SCCKS_CKS;
2421 			min_err = err;
2422 			srr = srr1;
2423 			if (!err)
2424 				goto done;
2425 		}
2426 	}
2427 
2428 	/* Optional BRG Frequency Divided External Clock */
2429 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2430 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2431 				   &srr1);
2432 		if (abs(err) < abs(min_err)) {
2433 			best_clk = SCI_SCIF_CLK;
2434 			scr_val = SCSCR_CKE1;
2435 			sccks = 0;
2436 			min_err = err;
2437 			dl = dl1;
2438 			srr = srr1;
2439 			if (!err)
2440 				goto done;
2441 		}
2442 	}
2443 
2444 	/* Optional BRG Frequency Divided Internal Clock */
2445 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2446 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2447 				   &srr1);
2448 		if (abs(err) < abs(min_err)) {
2449 			best_clk = SCI_BRG_INT;
2450 			scr_val = SCSCR_CKE1;
2451 			sccks = SCCKS_XIN;
2452 			min_err = err;
2453 			dl = dl1;
2454 			srr = srr1;
2455 			if (!min_err)
2456 				goto done;
2457 		}
2458 	}
2459 
2460 	/* Divided Functional Clock using standard Bit Rate Register */
2461 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2462 	if (abs(err) < abs(min_err)) {
2463 		best_clk = SCI_FCK;
2464 		scr_val = 0;
2465 		min_err = err;
2466 		brr = brr1;
2467 		srr = srr1;
2468 		cks = cks1;
2469 	}
2470 
2471 done:
2472 	if (best_clk >= 0)
2473 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2474 			s->clks[best_clk], baud, min_err);
2475 
2476 	sci_port_enable(s);
2477 
2478 	/*
2479 	 * Program the optional External Baud Rate Generator (BRG) first.
2480 	 * It controls the mux to select (H)SCK or frequency divided clock.
2481 	 */
2482 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2483 		serial_port_out(port, SCDL, dl);
2484 		serial_port_out(port, SCCKS, sccks);
2485 	}
2486 
2487 	spin_lock_irqsave(&port->lock, flags);
2488 
2489 	sci_reset(port);
2490 
2491 	uart_update_timeout(port, termios->c_cflag, baud);
2492 
2493 	/* byte size and parity */
2494 	switch (termios->c_cflag & CSIZE) {
2495 	case CS5:
2496 		bits = 7;
2497 		break;
2498 	case CS6:
2499 		bits = 8;
2500 		break;
2501 	case CS7:
2502 		bits = 9;
2503 		break;
2504 	default:
2505 		bits = 10;
2506 		break;
2507 	}
2508 
2509 	if (termios->c_cflag & CSTOPB)
2510 		bits++;
2511 	if (termios->c_cflag & PARENB)
2512 		bits++;
2513 
2514 	if (best_clk >= 0) {
2515 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2516 			switch (srr + 1) {
2517 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2518 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2519 			case 11: smr_val |= SCSMR_SRC_11; break;
2520 			case 13: smr_val |= SCSMR_SRC_13; break;
2521 			case 16: smr_val |= SCSMR_SRC_16; break;
2522 			case 17: smr_val |= SCSMR_SRC_17; break;
2523 			case 19: smr_val |= SCSMR_SRC_19; break;
2524 			case 27: smr_val |= SCSMR_SRC_27; break;
2525 			}
2526 		smr_val |= cks;
2527 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2528 		serial_port_out(port, SCSMR, smr_val);
2529 		serial_port_out(port, SCBRR, brr);
2530 		if (sci_getreg(port, HSSRR)->size) {
2531 			unsigned int hssrr = srr | HSCIF_SRE;
2532 			/* Calculate deviation from intended rate at the
2533 			 * center of the last stop bit in sampling clocks.
2534 			 */
2535 			int last_stop = bits * 2 - 1;
2536 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2537 							  (int)(srr + 1),
2538 							  2 * (int)baud);
2539 
2540 			if (abs(deviation) >= 2) {
2541 				/* At least two sampling clocks off at the
2542 				 * last stop bit; we can increase the error
2543 				 * margin by shifting the sampling point.
2544 				 */
2545 				int shift = clamp(deviation / 2, -8, 7);
2546 
2547 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2548 					 HSCIF_SRHP_MASK;
2549 				hssrr |= HSCIF_SRDE;
2550 			}
2551 			serial_port_out(port, HSSRR, hssrr);
2552 		}
2553 
2554 		/* Wait one bit interval */
2555 		udelay((1000000 + (baud - 1)) / baud);
2556 	} else {
2557 		/* Don't touch the bit rate configuration */
2558 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2559 		smr_val |= serial_port_in(port, SCSMR) &
2560 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2561 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2562 		serial_port_out(port, SCSMR, smr_val);
2563 	}
2564 
2565 	sci_init_pins(port, termios->c_cflag);
2566 
2567 	port->status &= ~UPSTAT_AUTOCTS;
2568 	s->autorts = false;
2569 	reg = sci_getreg(port, SCFCR);
2570 	if (reg->size) {
2571 		unsigned short ctrl = serial_port_in(port, SCFCR);
2572 
2573 		if ((port->flags & UPF_HARD_FLOW) &&
2574 		    (termios->c_cflag & CRTSCTS)) {
2575 			/* There is no CTS interrupt to restart the hardware */
2576 			port->status |= UPSTAT_AUTOCTS;
2577 			/* MCE is enabled when RTS is raised */
2578 			s->autorts = true;
2579 		}
2580 
2581 		/*
2582 		 * As we've done a sci_reset() above, ensure we don't
2583 		 * interfere with the FIFOs while toggling MCE. As the
2584 		 * reset values could still be set, simply mask them out.
2585 		 */
2586 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2587 
2588 		serial_port_out(port, SCFCR, ctrl);
2589 	}
2590 	if (port->flags & UPF_HARD_FLOW) {
2591 		/* Refresh (Auto) RTS */
2592 		sci_set_mctrl(port, port->mctrl);
2593 	}
2594 
2595 	scr_val |= SCSCR_RE | SCSCR_TE |
2596 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2597 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2598 	if ((srr + 1 == 5) &&
2599 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2600 		/*
2601 		 * In asynchronous mode, when the sampling rate is 1/5, first
2602 		 * received data may become invalid on some SCIFA and SCIFB.
2603 		 * To avoid this problem wait more than 1 serial data time (1
2604 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2605 		 */
2606 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2607 	}
2608 
2609 	/*
2610 	 * Calculate delay for 2 DMA buffers (4 FIFO).
2611 	 * See serial_core.c::uart_update_timeout().
2612 	 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2613 	 * function calculates 1 jiffie for the data plus 5 jiffies for the
2614 	 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2615 	 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2616 	 * value obtained by this formula is too small. Therefore, if the value
2617 	 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2618 	 */
2619 	s->rx_frame = (10000 * bits) / (baud / 100);
2620 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2621 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2622 	if (s->rx_timeout < 20)
2623 		s->rx_timeout = 20;
2624 #endif
2625 
2626 	if ((termios->c_cflag & CREAD) != 0)
2627 		sci_start_rx(port);
2628 
2629 	spin_unlock_irqrestore(&port->lock, flags);
2630 
2631 	sci_port_disable(s);
2632 
2633 	if (UART_ENABLE_MS(port, termios->c_cflag))
2634 		sci_enable_ms(port);
2635 }
2636 
2637 static void sci_pm(struct uart_port *port, unsigned int state,
2638 		   unsigned int oldstate)
2639 {
2640 	struct sci_port *sci_port = to_sci_port(port);
2641 
2642 	switch (state) {
2643 	case UART_PM_STATE_OFF:
2644 		sci_port_disable(sci_port);
2645 		break;
2646 	default:
2647 		sci_port_enable(sci_port);
2648 		break;
2649 	}
2650 }
2651 
2652 static const char *sci_type(struct uart_port *port)
2653 {
2654 	switch (port->type) {
2655 	case PORT_IRDA:
2656 		return "irda";
2657 	case PORT_SCI:
2658 		return "sci";
2659 	case PORT_SCIF:
2660 		return "scif";
2661 	case PORT_SCIFA:
2662 		return "scifa";
2663 	case PORT_SCIFB:
2664 		return "scifb";
2665 	case PORT_HSCIF:
2666 		return "hscif";
2667 	}
2668 
2669 	return NULL;
2670 }
2671 
2672 static int sci_remap_port(struct uart_port *port)
2673 {
2674 	struct sci_port *sport = to_sci_port(port);
2675 
2676 	/*
2677 	 * Nothing to do if there's already an established membase.
2678 	 */
2679 	if (port->membase)
2680 		return 0;
2681 
2682 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2683 		port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2684 		if (unlikely(!port->membase)) {
2685 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2686 			return -ENXIO;
2687 		}
2688 	} else {
2689 		/*
2690 		 * For the simple (and majority of) cases where we don't
2691 		 * need to do any remapping, just cast the cookie
2692 		 * directly.
2693 		 */
2694 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2695 	}
2696 
2697 	return 0;
2698 }
2699 
2700 static void sci_release_port(struct uart_port *port)
2701 {
2702 	struct sci_port *sport = to_sci_port(port);
2703 
2704 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2705 		iounmap(port->membase);
2706 		port->membase = NULL;
2707 	}
2708 
2709 	release_mem_region(port->mapbase, sport->reg_size);
2710 }
2711 
2712 static int sci_request_port(struct uart_port *port)
2713 {
2714 	struct resource *res;
2715 	struct sci_port *sport = to_sci_port(port);
2716 	int ret;
2717 
2718 	res = request_mem_region(port->mapbase, sport->reg_size,
2719 				 dev_name(port->dev));
2720 	if (unlikely(res == NULL)) {
2721 		dev_err(port->dev, "request_mem_region failed.");
2722 		return -EBUSY;
2723 	}
2724 
2725 	ret = sci_remap_port(port);
2726 	if (unlikely(ret != 0)) {
2727 		release_resource(res);
2728 		return ret;
2729 	}
2730 
2731 	return 0;
2732 }
2733 
2734 static void sci_config_port(struct uart_port *port, int flags)
2735 {
2736 	if (flags & UART_CONFIG_TYPE) {
2737 		struct sci_port *sport = to_sci_port(port);
2738 
2739 		port->type = sport->cfg->type;
2740 		sci_request_port(port);
2741 	}
2742 }
2743 
2744 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2745 {
2746 	if (ser->baud_base < 2400)
2747 		/* No paper tape reader for Mitch.. */
2748 		return -EINVAL;
2749 
2750 	return 0;
2751 }
2752 
2753 static const struct uart_ops sci_uart_ops = {
2754 	.tx_empty	= sci_tx_empty,
2755 	.set_mctrl	= sci_set_mctrl,
2756 	.get_mctrl	= sci_get_mctrl,
2757 	.start_tx	= sci_start_tx,
2758 	.stop_tx	= sci_stop_tx,
2759 	.stop_rx	= sci_stop_rx,
2760 	.enable_ms	= sci_enable_ms,
2761 	.break_ctl	= sci_break_ctl,
2762 	.startup	= sci_startup,
2763 	.shutdown	= sci_shutdown,
2764 	.flush_buffer	= sci_flush_buffer,
2765 	.set_termios	= sci_set_termios,
2766 	.pm		= sci_pm,
2767 	.type		= sci_type,
2768 	.release_port	= sci_release_port,
2769 	.request_port	= sci_request_port,
2770 	.config_port	= sci_config_port,
2771 	.verify_port	= sci_verify_port,
2772 #ifdef CONFIG_CONSOLE_POLL
2773 	.poll_get_char	= sci_poll_get_char,
2774 	.poll_put_char	= sci_poll_put_char,
2775 #endif
2776 };
2777 
2778 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2779 {
2780 	const char *clk_names[] = {
2781 		[SCI_FCK] = "fck",
2782 		[SCI_SCK] = "sck",
2783 		[SCI_BRG_INT] = "brg_int",
2784 		[SCI_SCIF_CLK] = "scif_clk",
2785 	};
2786 	struct clk *clk;
2787 	unsigned int i;
2788 
2789 	if (sci_port->cfg->type == PORT_HSCIF)
2790 		clk_names[SCI_SCK] = "hsck";
2791 
2792 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2793 		clk = devm_clk_get(dev, clk_names[i]);
2794 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2795 			return -EPROBE_DEFER;
2796 
2797 		if (IS_ERR(clk) && i == SCI_FCK) {
2798 			/*
2799 			 * "fck" used to be called "sci_ick", and we need to
2800 			 * maintain DT backward compatibility.
2801 			 */
2802 			clk = devm_clk_get(dev, "sci_ick");
2803 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2804 				return -EPROBE_DEFER;
2805 
2806 			if (!IS_ERR(clk))
2807 				goto found;
2808 
2809 			/*
2810 			 * Not all SH platforms declare a clock lookup entry
2811 			 * for SCI devices, in which case we need to get the
2812 			 * global "peripheral_clk" clock.
2813 			 */
2814 			clk = devm_clk_get(dev, "peripheral_clk");
2815 			if (!IS_ERR(clk))
2816 				goto found;
2817 
2818 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2819 				PTR_ERR(clk));
2820 			return PTR_ERR(clk);
2821 		}
2822 
2823 found:
2824 		if (IS_ERR(clk))
2825 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2826 				PTR_ERR(clk));
2827 		else
2828 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2829 				clk, clk_get_rate(clk));
2830 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2831 	}
2832 	return 0;
2833 }
2834 
2835 static const struct sci_port_params *
2836 sci_probe_regmap(const struct plat_sci_port *cfg)
2837 {
2838 	unsigned int regtype;
2839 
2840 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2841 		return &sci_port_params[cfg->regtype];
2842 
2843 	switch (cfg->type) {
2844 	case PORT_SCI:
2845 		regtype = SCIx_SCI_REGTYPE;
2846 		break;
2847 	case PORT_IRDA:
2848 		regtype = SCIx_IRDA_REGTYPE;
2849 		break;
2850 	case PORT_SCIFA:
2851 		regtype = SCIx_SCIFA_REGTYPE;
2852 		break;
2853 	case PORT_SCIFB:
2854 		regtype = SCIx_SCIFB_REGTYPE;
2855 		break;
2856 	case PORT_SCIF:
2857 		/*
2858 		 * The SH-4 is a bit of a misnomer here, although that's
2859 		 * where this particular port layout originated. This
2860 		 * configuration (or some slight variation thereof)
2861 		 * remains the dominant model for all SCIFs.
2862 		 */
2863 		regtype = SCIx_SH4_SCIF_REGTYPE;
2864 		break;
2865 	case PORT_HSCIF:
2866 		regtype = SCIx_HSCIF_REGTYPE;
2867 		break;
2868 	default:
2869 		pr_err("Can't probe register map for given port\n");
2870 		return NULL;
2871 	}
2872 
2873 	return &sci_port_params[regtype];
2874 }
2875 
2876 static int sci_init_single(struct platform_device *dev,
2877 			   struct sci_port *sci_port, unsigned int index,
2878 			   const struct plat_sci_port *p, bool early)
2879 {
2880 	struct uart_port *port = &sci_port->port;
2881 	const struct resource *res;
2882 	unsigned int i;
2883 	int ret;
2884 
2885 	sci_port->cfg	= p;
2886 
2887 	port->ops	= &sci_uart_ops;
2888 	port->iotype	= UPIO_MEM;
2889 	port->line	= index;
2890 
2891 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2892 	if (res == NULL)
2893 		return -ENOMEM;
2894 
2895 	port->mapbase = res->start;
2896 	sci_port->reg_size = resource_size(res);
2897 
2898 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2899 		if (i)
2900 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2901 		else
2902 			sci_port->irqs[i] = platform_get_irq(dev, i);
2903 	}
2904 
2905 	/* The SCI generates several interrupts. They can be muxed together or
2906 	 * connected to different interrupt lines. In the muxed case only one
2907 	 * interrupt resource is specified as there is only one interrupt ID.
2908 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2909 	 * from the SCI, however those signals might have their own individual
2910 	 * interrupt ID numbers, or muxed together with another interrupt.
2911 	 */
2912 	if (sci_port->irqs[0] < 0)
2913 		return -ENXIO;
2914 
2915 	if (sci_port->irqs[1] < 0)
2916 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2917 			sci_port->irqs[i] = sci_port->irqs[0];
2918 
2919 	sci_port->params = sci_probe_regmap(p);
2920 	if (unlikely(sci_port->params == NULL))
2921 		return -EINVAL;
2922 
2923 	switch (p->type) {
2924 	case PORT_SCIFB:
2925 		sci_port->rx_trigger = 48;
2926 		break;
2927 	case PORT_HSCIF:
2928 		sci_port->rx_trigger = 64;
2929 		break;
2930 	case PORT_SCIFA:
2931 		sci_port->rx_trigger = 32;
2932 		break;
2933 	case PORT_SCIF:
2934 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2935 			/* RX triggering not implemented for this IP */
2936 			sci_port->rx_trigger = 1;
2937 		else
2938 			sci_port->rx_trigger = 8;
2939 		break;
2940 	default:
2941 		sci_port->rx_trigger = 1;
2942 		break;
2943 	}
2944 
2945 	sci_port->rx_fifo_timeout = 0;
2946 	sci_port->hscif_tot = 0;
2947 
2948 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2949 	 * match the SoC datasheet, this should be investigated. Let platform
2950 	 * data override the sampling rate for now.
2951 	 */
2952 	sci_port->sampling_rate_mask = p->sampling_rate
2953 				     ? SCI_SR(p->sampling_rate)
2954 				     : sci_port->params->sampling_rate_mask;
2955 
2956 	if (!early) {
2957 		ret = sci_init_clocks(sci_port, &dev->dev);
2958 		if (ret < 0)
2959 			return ret;
2960 
2961 		port->dev = &dev->dev;
2962 
2963 		pm_runtime_enable(&dev->dev);
2964 	}
2965 
2966 	port->type		= p->type;
2967 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2968 	port->fifosize		= sci_port->params->fifosize;
2969 
2970 	if (port->type == PORT_SCI) {
2971 		if (sci_port->reg_size >= 0x20)
2972 			port->regshift = 2;
2973 		else
2974 			port->regshift = 1;
2975 	}
2976 
2977 	/*
2978 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2979 	 * for the multi-IRQ ports, which is where we are primarily
2980 	 * concerned with the shutdown path synchronization.
2981 	 *
2982 	 * For the muxed case there's nothing more to do.
2983 	 */
2984 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2985 	port->irqflags		= 0;
2986 
2987 	port->serial_in		= sci_serial_in;
2988 	port->serial_out	= sci_serial_out;
2989 
2990 	return 0;
2991 }
2992 
2993 static void sci_cleanup_single(struct sci_port *port)
2994 {
2995 	pm_runtime_disable(port->port.dev);
2996 }
2997 
2998 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2999     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3000 static void serial_console_putchar(struct uart_port *port, int ch)
3001 {
3002 	sci_poll_put_char(port, ch);
3003 }
3004 
3005 /*
3006  *	Print a string to the serial port trying not to disturb
3007  *	any possible real use of the port...
3008  */
3009 static void serial_console_write(struct console *co, const char *s,
3010 				 unsigned count)
3011 {
3012 	struct sci_port *sci_port = &sci_ports[co->index];
3013 	struct uart_port *port = &sci_port->port;
3014 	unsigned short bits, ctrl, ctrl_temp;
3015 	unsigned long flags;
3016 	int locked = 1;
3017 
3018 #if defined(SUPPORT_SYSRQ)
3019 	if (port->sysrq)
3020 		locked = 0;
3021 	else
3022 #endif
3023 	if (oops_in_progress)
3024 		locked = spin_trylock_irqsave(&port->lock, flags);
3025 	else
3026 		spin_lock_irqsave(&port->lock, flags);
3027 
3028 	/* first save SCSCR then disable interrupts, keep clock source */
3029 	ctrl = serial_port_in(port, SCSCR);
3030 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3031 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3032 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3033 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3034 
3035 	uart_console_write(port, s, count, serial_console_putchar);
3036 
3037 	/* wait until fifo is empty and last bit has been transmitted */
3038 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3039 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3040 		cpu_relax();
3041 
3042 	/* restore the SCSCR */
3043 	serial_port_out(port, SCSCR, ctrl);
3044 
3045 	if (locked)
3046 		spin_unlock_irqrestore(&port->lock, flags);
3047 }
3048 
3049 static int serial_console_setup(struct console *co, char *options)
3050 {
3051 	struct sci_port *sci_port;
3052 	struct uart_port *port;
3053 	int baud = 115200;
3054 	int bits = 8;
3055 	int parity = 'n';
3056 	int flow = 'n';
3057 	int ret;
3058 
3059 	/*
3060 	 * Refuse to handle any bogus ports.
3061 	 */
3062 	if (co->index < 0 || co->index >= SCI_NPORTS)
3063 		return -ENODEV;
3064 
3065 	sci_port = &sci_ports[co->index];
3066 	port = &sci_port->port;
3067 
3068 	/*
3069 	 * Refuse to handle uninitialized ports.
3070 	 */
3071 	if (!port->ops)
3072 		return -ENODEV;
3073 
3074 	ret = sci_remap_port(port);
3075 	if (unlikely(ret != 0))
3076 		return ret;
3077 
3078 	if (options)
3079 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3080 
3081 	return uart_set_options(port, co, baud, parity, bits, flow);
3082 }
3083 
3084 static struct console serial_console = {
3085 	.name		= "ttySC",
3086 	.device		= uart_console_device,
3087 	.write		= serial_console_write,
3088 	.setup		= serial_console_setup,
3089 	.flags		= CON_PRINTBUFFER,
3090 	.index		= -1,
3091 	.data		= &sci_uart_driver,
3092 };
3093 
3094 #ifdef CONFIG_SUPERH
3095 static struct console early_serial_console = {
3096 	.name           = "early_ttySC",
3097 	.write          = serial_console_write,
3098 	.flags          = CON_PRINTBUFFER,
3099 	.index		= -1,
3100 };
3101 
3102 static char early_serial_buf[32];
3103 
3104 static int sci_probe_earlyprintk(struct platform_device *pdev)
3105 {
3106 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3107 
3108 	if (early_serial_console.data)
3109 		return -EEXIST;
3110 
3111 	early_serial_console.index = pdev->id;
3112 
3113 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3114 
3115 	serial_console_setup(&early_serial_console, early_serial_buf);
3116 
3117 	if (!strstr(early_serial_buf, "keep"))
3118 		early_serial_console.flags |= CON_BOOT;
3119 
3120 	register_console(&early_serial_console);
3121 	return 0;
3122 }
3123 #endif
3124 
3125 #define SCI_CONSOLE	(&serial_console)
3126 
3127 #else
3128 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3129 {
3130 	return -EINVAL;
3131 }
3132 
3133 #define SCI_CONSOLE	NULL
3134 
3135 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3136 
3137 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3138 
3139 static DEFINE_MUTEX(sci_uart_registration_lock);
3140 static struct uart_driver sci_uart_driver = {
3141 	.owner		= THIS_MODULE,
3142 	.driver_name	= "sci",
3143 	.dev_name	= "ttySC",
3144 	.major		= SCI_MAJOR,
3145 	.minor		= SCI_MINOR_START,
3146 	.nr		= SCI_NPORTS,
3147 	.cons		= SCI_CONSOLE,
3148 };
3149 
3150 static int sci_remove(struct platform_device *dev)
3151 {
3152 	struct sci_port *port = platform_get_drvdata(dev);
3153 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3154 
3155 	sci_ports_in_use &= ~BIT(port->port.line);
3156 	uart_remove_one_port(&sci_uart_driver, &port->port);
3157 
3158 	sci_cleanup_single(port);
3159 
3160 	if (port->port.fifosize > 1)
3161 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3162 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3163 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3164 
3165 	return 0;
3166 }
3167 
3168 
3169 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3170 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3171 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3172 
3173 static const struct of_device_id of_sci_match[] = {
3174 	/* SoC-specific types */
3175 	{
3176 		.compatible = "renesas,scif-r7s72100",
3177 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3178 	},
3179 	{
3180 		.compatible = "renesas,scif-r7s9210",
3181 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3182 	},
3183 	/* Family-specific types */
3184 	{
3185 		.compatible = "renesas,rcar-gen1-scif",
3186 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3187 	}, {
3188 		.compatible = "renesas,rcar-gen2-scif",
3189 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3190 	}, {
3191 		.compatible = "renesas,rcar-gen3-scif",
3192 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3193 	},
3194 	/* Generic types */
3195 	{
3196 		.compatible = "renesas,scif",
3197 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3198 	}, {
3199 		.compatible = "renesas,scifa",
3200 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3201 	}, {
3202 		.compatible = "renesas,scifb",
3203 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3204 	}, {
3205 		.compatible = "renesas,hscif",
3206 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3207 	}, {
3208 		.compatible = "renesas,sci",
3209 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3210 	}, {
3211 		/* Terminator */
3212 	},
3213 };
3214 MODULE_DEVICE_TABLE(of, of_sci_match);
3215 
3216 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3217 					  unsigned int *dev_id)
3218 {
3219 	struct device_node *np = pdev->dev.of_node;
3220 	struct plat_sci_port *p;
3221 	struct sci_port *sp;
3222 	const void *data;
3223 	int id;
3224 
3225 	if (!IS_ENABLED(CONFIG_OF) || !np)
3226 		return NULL;
3227 
3228 	data = of_device_get_match_data(&pdev->dev);
3229 
3230 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3231 	if (!p)
3232 		return NULL;
3233 
3234 	/* Get the line number from the aliases node. */
3235 	id = of_alias_get_id(np, "serial");
3236 	if (id < 0 && ~sci_ports_in_use)
3237 		id = ffz(sci_ports_in_use);
3238 	if (id < 0) {
3239 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3240 		return NULL;
3241 	}
3242 	if (id >= ARRAY_SIZE(sci_ports)) {
3243 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3244 		return NULL;
3245 	}
3246 
3247 	sp = &sci_ports[id];
3248 	*dev_id = id;
3249 
3250 	p->type = SCI_OF_TYPE(data);
3251 	p->regtype = SCI_OF_REGTYPE(data);
3252 
3253 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3254 
3255 	return p;
3256 }
3257 
3258 static int sci_probe_single(struct platform_device *dev,
3259 				      unsigned int index,
3260 				      struct plat_sci_port *p,
3261 				      struct sci_port *sciport)
3262 {
3263 	int ret;
3264 
3265 	/* Sanity check */
3266 	if (unlikely(index >= SCI_NPORTS)) {
3267 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3268 			   index+1, SCI_NPORTS);
3269 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3270 		return -EINVAL;
3271 	}
3272 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3273 	if (sci_ports_in_use & BIT(index))
3274 		return -EBUSY;
3275 
3276 	mutex_lock(&sci_uart_registration_lock);
3277 	if (!sci_uart_driver.state) {
3278 		ret = uart_register_driver(&sci_uart_driver);
3279 		if (ret) {
3280 			mutex_unlock(&sci_uart_registration_lock);
3281 			return ret;
3282 		}
3283 	}
3284 	mutex_unlock(&sci_uart_registration_lock);
3285 
3286 	ret = sci_init_single(dev, sciport, index, p, false);
3287 	if (ret)
3288 		return ret;
3289 
3290 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3291 	if (IS_ERR(sciport->gpios))
3292 		return PTR_ERR(sciport->gpios);
3293 
3294 	if (sciport->has_rtscts) {
3295 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3296 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3297 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3298 			return -EINVAL;
3299 		}
3300 		sciport->port.flags |= UPF_HARD_FLOW;
3301 	}
3302 
3303 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3304 	if (ret) {
3305 		sci_cleanup_single(sciport);
3306 		return ret;
3307 	}
3308 
3309 	return 0;
3310 }
3311 
3312 static int sci_probe(struct platform_device *dev)
3313 {
3314 	struct plat_sci_port *p;
3315 	struct sci_port *sp;
3316 	unsigned int dev_id;
3317 	int ret;
3318 
3319 	/*
3320 	 * If we've come here via earlyprintk initialization, head off to
3321 	 * the special early probe. We don't have sufficient device state
3322 	 * to make it beyond this yet.
3323 	 */
3324 #ifdef CONFIG_SUPERH
3325 	if (is_sh_early_platform_device(dev))
3326 		return sci_probe_earlyprintk(dev);
3327 #endif
3328 
3329 	if (dev->dev.of_node) {
3330 		p = sci_parse_dt(dev, &dev_id);
3331 		if (p == NULL)
3332 			return -EINVAL;
3333 	} else {
3334 		p = dev->dev.platform_data;
3335 		if (p == NULL) {
3336 			dev_err(&dev->dev, "no platform data supplied\n");
3337 			return -EINVAL;
3338 		}
3339 
3340 		dev_id = dev->id;
3341 	}
3342 
3343 	sp = &sci_ports[dev_id];
3344 	platform_set_drvdata(dev, sp);
3345 
3346 	ret = sci_probe_single(dev, dev_id, p, sp);
3347 	if (ret)
3348 		return ret;
3349 
3350 	if (sp->port.fifosize > 1) {
3351 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3352 		if (ret)
3353 			return ret;
3354 	}
3355 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3356 	    sp->port.type == PORT_HSCIF) {
3357 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3358 		if (ret) {
3359 			if (sp->port.fifosize > 1) {
3360 				device_remove_file(&dev->dev,
3361 						   &dev_attr_rx_fifo_trigger);
3362 			}
3363 			return ret;
3364 		}
3365 	}
3366 
3367 #ifdef CONFIG_SH_STANDARD_BIOS
3368 	sh_bios_gdb_detach();
3369 #endif
3370 
3371 	sci_ports_in_use |= BIT(dev_id);
3372 	return 0;
3373 }
3374 
3375 static __maybe_unused int sci_suspend(struct device *dev)
3376 {
3377 	struct sci_port *sport = dev_get_drvdata(dev);
3378 
3379 	if (sport)
3380 		uart_suspend_port(&sci_uart_driver, &sport->port);
3381 
3382 	return 0;
3383 }
3384 
3385 static __maybe_unused int sci_resume(struct device *dev)
3386 {
3387 	struct sci_port *sport = dev_get_drvdata(dev);
3388 
3389 	if (sport)
3390 		uart_resume_port(&sci_uart_driver, &sport->port);
3391 
3392 	return 0;
3393 }
3394 
3395 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3396 
3397 static struct platform_driver sci_driver = {
3398 	.probe		= sci_probe,
3399 	.remove		= sci_remove,
3400 	.driver		= {
3401 		.name	= "sh-sci",
3402 		.pm	= &sci_dev_pm_ops,
3403 		.of_match_table = of_match_ptr(of_sci_match),
3404 	},
3405 };
3406 
3407 static int __init sci_init(void)
3408 {
3409 	pr_info("%s\n", banner);
3410 
3411 	return platform_driver_register(&sci_driver);
3412 }
3413 
3414 static void __exit sci_exit(void)
3415 {
3416 	platform_driver_unregister(&sci_driver);
3417 
3418 	if (sci_uart_driver.state)
3419 		uart_unregister_driver(&sci_uart_driver);
3420 }
3421 
3422 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3423 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3424 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3425 #endif
3426 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3427 static struct plat_sci_port port_cfg __initdata;
3428 
3429 static int __init early_console_setup(struct earlycon_device *device,
3430 				      int type)
3431 {
3432 	if (!device->port.membase)
3433 		return -ENODEV;
3434 
3435 	device->port.serial_in = sci_serial_in;
3436 	device->port.serial_out	= sci_serial_out;
3437 	device->port.type = type;
3438 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3439 	port_cfg.type = type;
3440 	sci_ports[0].cfg = &port_cfg;
3441 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3442 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3443 	sci_serial_out(&sci_ports[0].port, SCSCR,
3444 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3445 
3446 	device->con->write = serial_console_write;
3447 	return 0;
3448 }
3449 static int __init sci_early_console_setup(struct earlycon_device *device,
3450 					  const char *opt)
3451 {
3452 	return early_console_setup(device, PORT_SCI);
3453 }
3454 static int __init scif_early_console_setup(struct earlycon_device *device,
3455 					  const char *opt)
3456 {
3457 	return early_console_setup(device, PORT_SCIF);
3458 }
3459 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3460 					  const char *opt)
3461 {
3462 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3463 	return early_console_setup(device, PORT_SCIF);
3464 }
3465 static int __init scifa_early_console_setup(struct earlycon_device *device,
3466 					  const char *opt)
3467 {
3468 	return early_console_setup(device, PORT_SCIFA);
3469 }
3470 static int __init scifb_early_console_setup(struct earlycon_device *device,
3471 					  const char *opt)
3472 {
3473 	return early_console_setup(device, PORT_SCIFB);
3474 }
3475 static int __init hscif_early_console_setup(struct earlycon_device *device,
3476 					  const char *opt)
3477 {
3478 	return early_console_setup(device, PORT_HSCIF);
3479 }
3480 
3481 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3482 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3483 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3484 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3485 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3486 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3487 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3488 
3489 module_init(sci_init);
3490 module_exit(sci_exit);
3491 
3492 MODULE_LICENSE("GPL");
3493 MODULE_ALIAS("platform:sh-sci");
3494 MODULE_AUTHOR("Paul Mundt");
3495 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3496