xref: /linux/drivers/tty/serial/sh-sci.c (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #undef DEBUG
19 
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/module.h>
35 #include <linux/mm.h>
36 #include <linux/of.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm_runtime.h>
40 #include <linux/scatterlist.h>
41 #include <linux/serial.h>
42 #include <linux/serial_sci.h>
43 #include <linux/sh_dma.h>
44 #include <linux/slab.h>
45 #include <linux/string.h>
46 #include <linux/sysrq.h>
47 #include <linux/timer.h>
48 #include <linux/tty.h>
49 #include <linux/tty_flip.h>
50 
51 #ifdef CONFIG_SUPERH
52 #include <asm/sh_bios.h>
53 #include <asm/platform_early.h>
54 #endif
55 
56 #include "serial_mctrl_gpio.h"
57 #include "sh-sci.h"
58 
59 /* Offsets into the sci_port->irqs array */
60 enum {
61 	SCIx_ERI_IRQ,
62 	SCIx_RXI_IRQ,
63 	SCIx_TXI_IRQ,
64 	SCIx_BRI_IRQ,
65 	SCIx_DRI_IRQ,
66 	SCIx_TEI_IRQ,
67 	SCIx_NR_IRQS,
68 
69 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
70 };
71 
72 #define SCIx_IRQ_IS_MUXED(port)			\
73 	((port)->irqs[SCIx_ERI_IRQ] ==	\
74 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
75 	((port)->irqs[SCIx_ERI_IRQ] &&	\
76 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
77 
78 enum SCI_CLKS {
79 	SCI_FCK,		/* Functional Clock */
80 	SCI_SCK,		/* Optional External Clock */
81 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
82 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
83 	SCI_NUM_CLKS
84 };
85 
86 /* Bit x set means sampling rate x + 1 is supported */
87 #define SCI_SR(x)		BIT((x) - 1)
88 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
89 
90 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
91 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
92 				SCI_SR(19) | SCI_SR(27)
93 
94 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
95 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
96 
97 /* Iterate over all supported sampling rates, from high to low */
98 #define for_each_sr(_sr, _port)						\
99 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
100 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
101 
102 struct plat_sci_reg {
103 	u8 offset, size;
104 };
105 
106 struct sci_port_params {
107 	const struct plat_sci_reg regs[SCIx_NR_REGS];
108 	unsigned int fifosize;
109 	unsigned int overrun_reg;
110 	unsigned int overrun_mask;
111 	unsigned int sampling_rate_mask;
112 	unsigned int error_mask;
113 	unsigned int error_clear;
114 };
115 
116 struct sci_port {
117 	struct uart_port	port;
118 
119 	/* Platform configuration */
120 	const struct sci_port_params *params;
121 	const struct plat_sci_port *cfg;
122 	unsigned int		sampling_rate_mask;
123 	resource_size_t		reg_size;
124 	struct mctrl_gpios	*gpios;
125 
126 	/* Clocks */
127 	struct clk		*clks[SCI_NUM_CLKS];
128 	unsigned long		clk_rates[SCI_NUM_CLKS];
129 
130 	int			irqs[SCIx_NR_IRQS];
131 	char			*irqstr[SCIx_NR_IRQS];
132 
133 	struct dma_chan			*chan_tx;
134 	struct dma_chan			*chan_rx;
135 
136 #ifdef CONFIG_SERIAL_SH_SCI_DMA
137 	struct dma_chan			*chan_tx_saved;
138 	struct dma_chan			*chan_rx_saved;
139 	dma_cookie_t			cookie_tx;
140 	dma_cookie_t			cookie_rx[2];
141 	dma_cookie_t			active_rx;
142 	dma_addr_t			tx_dma_addr;
143 	unsigned int			tx_dma_len;
144 	struct scatterlist		sg_rx[2];
145 	void				*rx_buf[2];
146 	size_t				buf_len_rx;
147 	struct work_struct		work_tx;
148 	struct hrtimer			rx_timer;
149 	unsigned int			rx_timeout;	/* microseconds */
150 #endif
151 	unsigned int			rx_frame;
152 	int				rx_trigger;
153 	struct timer_list		rx_fifo_timer;
154 	int				rx_fifo_timeout;
155 	u16				hscif_tot;
156 
157 	bool has_rtscts;
158 	bool autorts;
159 };
160 
161 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
162 
163 static struct sci_port sci_ports[SCI_NPORTS];
164 static unsigned long sci_ports_in_use;
165 static struct uart_driver sci_uart_driver;
166 
167 static inline struct sci_port *
168 to_sci_port(struct uart_port *uart)
169 {
170 	return container_of(uart, struct sci_port, port);
171 }
172 
173 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
174 	/*
175 	 * Common SCI definitions, dependent on the port's regshift
176 	 * value.
177 	 */
178 	[SCIx_SCI_REGTYPE] = {
179 		.regs = {
180 			[SCSMR]		= { 0x00,  8 },
181 			[SCBRR]		= { 0x01,  8 },
182 			[SCSCR]		= { 0x02,  8 },
183 			[SCxTDR]	= { 0x03,  8 },
184 			[SCxSR]		= { 0x04,  8 },
185 			[SCxRDR]	= { 0x05,  8 },
186 		},
187 		.fifosize = 1,
188 		.overrun_reg = SCxSR,
189 		.overrun_mask = SCI_ORER,
190 		.sampling_rate_mask = SCI_SR(32),
191 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
192 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
193 	},
194 
195 	/*
196 	 * Common definitions for legacy IrDA ports.
197 	 */
198 	[SCIx_IRDA_REGTYPE] = {
199 		.regs = {
200 			[SCSMR]		= { 0x00,  8 },
201 			[SCBRR]		= { 0x02,  8 },
202 			[SCSCR]		= { 0x04,  8 },
203 			[SCxTDR]	= { 0x06,  8 },
204 			[SCxSR]		= { 0x08, 16 },
205 			[SCxRDR]	= { 0x0a,  8 },
206 			[SCFCR]		= { 0x0c,  8 },
207 			[SCFDR]		= { 0x0e, 16 },
208 		},
209 		.fifosize = 1,
210 		.overrun_reg = SCxSR,
211 		.overrun_mask = SCI_ORER,
212 		.sampling_rate_mask = SCI_SR(32),
213 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
214 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
215 	},
216 
217 	/*
218 	 * Common SCIFA definitions.
219 	 */
220 	[SCIx_SCIFA_REGTYPE] = {
221 		.regs = {
222 			[SCSMR]		= { 0x00, 16 },
223 			[SCBRR]		= { 0x04,  8 },
224 			[SCSCR]		= { 0x08, 16 },
225 			[SCxTDR]	= { 0x20,  8 },
226 			[SCxSR]		= { 0x14, 16 },
227 			[SCxRDR]	= { 0x24,  8 },
228 			[SCFCR]		= { 0x18, 16 },
229 			[SCFDR]		= { 0x1c, 16 },
230 			[SCPCR]		= { 0x30, 16 },
231 			[SCPDR]		= { 0x34, 16 },
232 		},
233 		.fifosize = 64,
234 		.overrun_reg = SCxSR,
235 		.overrun_mask = SCIFA_ORER,
236 		.sampling_rate_mask = SCI_SR_SCIFAB,
237 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
238 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
239 	},
240 
241 	/*
242 	 * Common SCIFB definitions.
243 	 */
244 	[SCIx_SCIFB_REGTYPE] = {
245 		.regs = {
246 			[SCSMR]		= { 0x00, 16 },
247 			[SCBRR]		= { 0x04,  8 },
248 			[SCSCR]		= { 0x08, 16 },
249 			[SCxTDR]	= { 0x40,  8 },
250 			[SCxSR]		= { 0x14, 16 },
251 			[SCxRDR]	= { 0x60,  8 },
252 			[SCFCR]		= { 0x18, 16 },
253 			[SCTFDR]	= { 0x38, 16 },
254 			[SCRFDR]	= { 0x3c, 16 },
255 			[SCPCR]		= { 0x30, 16 },
256 			[SCPDR]		= { 0x34, 16 },
257 		},
258 		.fifosize = 256,
259 		.overrun_reg = SCxSR,
260 		.overrun_mask = SCIFA_ORER,
261 		.sampling_rate_mask = SCI_SR_SCIFAB,
262 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
263 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
264 	},
265 
266 	/*
267 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
268 	 * count registers.
269 	 */
270 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
271 		.regs = {
272 			[SCSMR]		= { 0x00, 16 },
273 			[SCBRR]		= { 0x04,  8 },
274 			[SCSCR]		= { 0x08, 16 },
275 			[SCxTDR]	= { 0x0c,  8 },
276 			[SCxSR]		= { 0x10, 16 },
277 			[SCxRDR]	= { 0x14,  8 },
278 			[SCFCR]		= { 0x18, 16 },
279 			[SCFDR]		= { 0x1c, 16 },
280 			[SCSPTR]	= { 0x20, 16 },
281 			[SCLSR]		= { 0x24, 16 },
282 		},
283 		.fifosize = 16,
284 		.overrun_reg = SCLSR,
285 		.overrun_mask = SCLSR_ORER,
286 		.sampling_rate_mask = SCI_SR(32),
287 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
288 		.error_clear = SCIF_ERROR_CLEAR,
289 	},
290 
291 	/*
292 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
293 	 * It looks like a normal SCIF with FIFO data, but with a
294 	 * compressed address space. Also, the break out of interrupts
295 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
296 	 */
297 	[SCIx_RZ_SCIFA_REGTYPE] = {
298 		.regs = {
299 			[SCSMR]		= { 0x00, 16 },
300 			[SCBRR]		= { 0x02,  8 },
301 			[SCSCR]		= { 0x04, 16 },
302 			[SCxTDR]	= { 0x06,  8 },
303 			[SCxSR]		= { 0x08, 16 },
304 			[SCxRDR]	= { 0x0A,  8 },
305 			[SCFCR]		= { 0x0C, 16 },
306 			[SCFDR]		= { 0x0E, 16 },
307 			[SCSPTR]	= { 0x10, 16 },
308 			[SCLSR]		= { 0x12, 16 },
309 			[SEMR]		= { 0x14, 8 },
310 		},
311 		.fifosize = 16,
312 		.overrun_reg = SCLSR,
313 		.overrun_mask = SCLSR_ORER,
314 		.sampling_rate_mask = SCI_SR(32),
315 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
316 		.error_clear = SCIF_ERROR_CLEAR,
317 	},
318 
319 	/*
320 	 * Common SH-3 SCIF definitions.
321 	 */
322 	[SCIx_SH3_SCIF_REGTYPE] = {
323 		.regs = {
324 			[SCSMR]		= { 0x00,  8 },
325 			[SCBRR]		= { 0x02,  8 },
326 			[SCSCR]		= { 0x04,  8 },
327 			[SCxTDR]	= { 0x06,  8 },
328 			[SCxSR]		= { 0x08, 16 },
329 			[SCxRDR]	= { 0x0a,  8 },
330 			[SCFCR]		= { 0x0c,  8 },
331 			[SCFDR]		= { 0x0e, 16 },
332 		},
333 		.fifosize = 16,
334 		.overrun_reg = SCLSR,
335 		.overrun_mask = SCLSR_ORER,
336 		.sampling_rate_mask = SCI_SR(32),
337 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
338 		.error_clear = SCIF_ERROR_CLEAR,
339 	},
340 
341 	/*
342 	 * Common SH-4(A) SCIF(B) definitions.
343 	 */
344 	[SCIx_SH4_SCIF_REGTYPE] = {
345 		.regs = {
346 			[SCSMR]		= { 0x00, 16 },
347 			[SCBRR]		= { 0x04,  8 },
348 			[SCSCR]		= { 0x08, 16 },
349 			[SCxTDR]	= { 0x0c,  8 },
350 			[SCxSR]		= { 0x10, 16 },
351 			[SCxRDR]	= { 0x14,  8 },
352 			[SCFCR]		= { 0x18, 16 },
353 			[SCFDR]		= { 0x1c, 16 },
354 			[SCSPTR]	= { 0x20, 16 },
355 			[SCLSR]		= { 0x24, 16 },
356 		},
357 		.fifosize = 16,
358 		.overrun_reg = SCLSR,
359 		.overrun_mask = SCLSR_ORER,
360 		.sampling_rate_mask = SCI_SR(32),
361 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
362 		.error_clear = SCIF_ERROR_CLEAR,
363 	},
364 
365 	/*
366 	 * Common SCIF definitions for ports with a Baud Rate Generator for
367 	 * External Clock (BRG).
368 	 */
369 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
370 		.regs = {
371 			[SCSMR]		= { 0x00, 16 },
372 			[SCBRR]		= { 0x04,  8 },
373 			[SCSCR]		= { 0x08, 16 },
374 			[SCxTDR]	= { 0x0c,  8 },
375 			[SCxSR]		= { 0x10, 16 },
376 			[SCxRDR]	= { 0x14,  8 },
377 			[SCFCR]		= { 0x18, 16 },
378 			[SCFDR]		= { 0x1c, 16 },
379 			[SCSPTR]	= { 0x20, 16 },
380 			[SCLSR]		= { 0x24, 16 },
381 			[SCDL]		= { 0x30, 16 },
382 			[SCCKS]		= { 0x34, 16 },
383 		},
384 		.fifosize = 16,
385 		.overrun_reg = SCLSR,
386 		.overrun_mask = SCLSR_ORER,
387 		.sampling_rate_mask = SCI_SR(32),
388 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
389 		.error_clear = SCIF_ERROR_CLEAR,
390 	},
391 
392 	/*
393 	 * Common HSCIF definitions.
394 	 */
395 	[SCIx_HSCIF_REGTYPE] = {
396 		.regs = {
397 			[SCSMR]		= { 0x00, 16 },
398 			[SCBRR]		= { 0x04,  8 },
399 			[SCSCR]		= { 0x08, 16 },
400 			[SCxTDR]	= { 0x0c,  8 },
401 			[SCxSR]		= { 0x10, 16 },
402 			[SCxRDR]	= { 0x14,  8 },
403 			[SCFCR]		= { 0x18, 16 },
404 			[SCFDR]		= { 0x1c, 16 },
405 			[SCSPTR]	= { 0x20, 16 },
406 			[SCLSR]		= { 0x24, 16 },
407 			[HSSRR]		= { 0x40, 16 },
408 			[SCDL]		= { 0x30, 16 },
409 			[SCCKS]		= { 0x34, 16 },
410 			[HSRTRGR]	= { 0x54, 16 },
411 			[HSTTRGR]	= { 0x58, 16 },
412 		},
413 		.fifosize = 128,
414 		.overrun_reg = SCLSR,
415 		.overrun_mask = SCLSR_ORER,
416 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
417 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
418 		.error_clear = SCIF_ERROR_CLEAR,
419 	},
420 
421 	/*
422 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
423 	 * register.
424 	 */
425 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
426 		.regs = {
427 			[SCSMR]		= { 0x00, 16 },
428 			[SCBRR]		= { 0x04,  8 },
429 			[SCSCR]		= { 0x08, 16 },
430 			[SCxTDR]	= { 0x0c,  8 },
431 			[SCxSR]		= { 0x10, 16 },
432 			[SCxRDR]	= { 0x14,  8 },
433 			[SCFCR]		= { 0x18, 16 },
434 			[SCFDR]		= { 0x1c, 16 },
435 			[SCLSR]		= { 0x24, 16 },
436 		},
437 		.fifosize = 16,
438 		.overrun_reg = SCLSR,
439 		.overrun_mask = SCLSR_ORER,
440 		.sampling_rate_mask = SCI_SR(32),
441 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
442 		.error_clear = SCIF_ERROR_CLEAR,
443 	},
444 
445 	/*
446 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
447 	 * count registers.
448 	 */
449 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
450 		.regs = {
451 			[SCSMR]		= { 0x00, 16 },
452 			[SCBRR]		= { 0x04,  8 },
453 			[SCSCR]		= { 0x08, 16 },
454 			[SCxTDR]	= { 0x0c,  8 },
455 			[SCxSR]		= { 0x10, 16 },
456 			[SCxRDR]	= { 0x14,  8 },
457 			[SCFCR]		= { 0x18, 16 },
458 			[SCFDR]		= { 0x1c, 16 },
459 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
460 			[SCRFDR]	= { 0x20, 16 },
461 			[SCSPTR]	= { 0x24, 16 },
462 			[SCLSR]		= { 0x28, 16 },
463 		},
464 		.fifosize = 16,
465 		.overrun_reg = SCLSR,
466 		.overrun_mask = SCLSR_ORER,
467 		.sampling_rate_mask = SCI_SR(32),
468 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
469 		.error_clear = SCIF_ERROR_CLEAR,
470 	},
471 
472 	/*
473 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
474 	 * registers.
475 	 */
476 	[SCIx_SH7705_SCIF_REGTYPE] = {
477 		.regs = {
478 			[SCSMR]		= { 0x00, 16 },
479 			[SCBRR]		= { 0x04,  8 },
480 			[SCSCR]		= { 0x08, 16 },
481 			[SCxTDR]	= { 0x20,  8 },
482 			[SCxSR]		= { 0x14, 16 },
483 			[SCxRDR]	= { 0x24,  8 },
484 			[SCFCR]		= { 0x18, 16 },
485 			[SCFDR]		= { 0x1c, 16 },
486 		},
487 		.fifosize = 64,
488 		.overrun_reg = SCxSR,
489 		.overrun_mask = SCIFA_ORER,
490 		.sampling_rate_mask = SCI_SR(16),
491 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
492 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
493 	},
494 };
495 
496 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
497 
498 /*
499  * The "offset" here is rather misleading, in that it refers to an enum
500  * value relative to the port mapping rather than the fixed offset
501  * itself, which needs to be manually retrieved from the platform's
502  * register map for the given port.
503  */
504 static unsigned int sci_serial_in(struct uart_port *p, int offset)
505 {
506 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
507 
508 	if (reg->size == 8)
509 		return ioread8(p->membase + (reg->offset << p->regshift));
510 	else if (reg->size == 16)
511 		return ioread16(p->membase + (reg->offset << p->regshift));
512 	else
513 		WARN(1, "Invalid register access\n");
514 
515 	return 0;
516 }
517 
518 static void sci_serial_out(struct uart_port *p, int offset, int value)
519 {
520 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
521 
522 	if (reg->size == 8)
523 		iowrite8(value, p->membase + (reg->offset << p->regshift));
524 	else if (reg->size == 16)
525 		iowrite16(value, p->membase + (reg->offset << p->regshift));
526 	else
527 		WARN(1, "Invalid register access\n");
528 }
529 
530 static void sci_port_enable(struct sci_port *sci_port)
531 {
532 	unsigned int i;
533 
534 	if (!sci_port->port.dev)
535 		return;
536 
537 	pm_runtime_get_sync(sci_port->port.dev);
538 
539 	for (i = 0; i < SCI_NUM_CLKS; i++) {
540 		clk_prepare_enable(sci_port->clks[i]);
541 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
542 	}
543 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
544 }
545 
546 static void sci_port_disable(struct sci_port *sci_port)
547 {
548 	unsigned int i;
549 
550 	if (!sci_port->port.dev)
551 		return;
552 
553 	for (i = SCI_NUM_CLKS; i-- > 0; )
554 		clk_disable_unprepare(sci_port->clks[i]);
555 
556 	pm_runtime_put_sync(sci_port->port.dev);
557 }
558 
559 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
560 {
561 	/*
562 	 * Not all ports (such as SCIFA) will support REIE. Rather than
563 	 * special-casing the port type, we check the port initialization
564 	 * IRQ enable mask to see whether the IRQ is desired at all. If
565 	 * it's unset, it's logically inferred that there's no point in
566 	 * testing for it.
567 	 */
568 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
569 }
570 
571 static void sci_start_tx(struct uart_port *port)
572 {
573 	struct sci_port *s = to_sci_port(port);
574 	unsigned short ctrl;
575 
576 #ifdef CONFIG_SERIAL_SH_SCI_DMA
577 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
578 		u16 new, scr = serial_port_in(port, SCSCR);
579 		if (s->chan_tx)
580 			new = scr | SCSCR_TDRQE;
581 		else
582 			new = scr & ~SCSCR_TDRQE;
583 		if (new != scr)
584 			serial_port_out(port, SCSCR, new);
585 	}
586 
587 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
588 	    dma_submit_error(s->cookie_tx)) {
589 		s->cookie_tx = 0;
590 		schedule_work(&s->work_tx);
591 	}
592 #endif
593 
594 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
595 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
596 		ctrl = serial_port_in(port, SCSCR);
597 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
598 	}
599 }
600 
601 static void sci_stop_tx(struct uart_port *port)
602 {
603 	unsigned short ctrl;
604 
605 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
606 	ctrl = serial_port_in(port, SCSCR);
607 
608 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
609 		ctrl &= ~SCSCR_TDRQE;
610 
611 	ctrl &= ~SCSCR_TIE;
612 
613 	serial_port_out(port, SCSCR, ctrl);
614 
615 #ifdef CONFIG_SERIAL_SH_SCI_DMA
616 	if (to_sci_port(port)->chan_tx &&
617 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
618 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
619 		to_sci_port(port)->cookie_tx = -EINVAL;
620 	}
621 #endif
622 }
623 
624 static void sci_start_rx(struct uart_port *port)
625 {
626 	unsigned short ctrl;
627 
628 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
629 
630 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
631 		ctrl &= ~SCSCR_RDRQE;
632 
633 	serial_port_out(port, SCSCR, ctrl);
634 }
635 
636 static void sci_stop_rx(struct uart_port *port)
637 {
638 	unsigned short ctrl;
639 
640 	ctrl = serial_port_in(port, SCSCR);
641 
642 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
643 		ctrl &= ~SCSCR_RDRQE;
644 
645 	ctrl &= ~port_rx_irq_mask(port);
646 
647 	serial_port_out(port, SCSCR, ctrl);
648 }
649 
650 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
651 {
652 	if (port->type == PORT_SCI) {
653 		/* Just store the mask */
654 		serial_port_out(port, SCxSR, mask);
655 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
656 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
657 		/* Only clear the status bits we want to clear */
658 		serial_port_out(port, SCxSR,
659 				serial_port_in(port, SCxSR) & mask);
660 	} else {
661 		/* Store the mask, clear parity/framing errors */
662 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
663 	}
664 }
665 
666 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
667     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
668 
669 #ifdef CONFIG_CONSOLE_POLL
670 static int sci_poll_get_char(struct uart_port *port)
671 {
672 	unsigned short status;
673 	int c;
674 
675 	do {
676 		status = serial_port_in(port, SCxSR);
677 		if (status & SCxSR_ERRORS(port)) {
678 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
679 			continue;
680 		}
681 		break;
682 	} while (1);
683 
684 	if (!(status & SCxSR_RDxF(port)))
685 		return NO_POLL_CHAR;
686 
687 	c = serial_port_in(port, SCxRDR);
688 
689 	/* Dummy read */
690 	serial_port_in(port, SCxSR);
691 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
692 
693 	return c;
694 }
695 #endif
696 
697 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
698 {
699 	unsigned short status;
700 
701 	do {
702 		status = serial_port_in(port, SCxSR);
703 	} while (!(status & SCxSR_TDxE(port)));
704 
705 	serial_port_out(port, SCxTDR, c);
706 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
707 }
708 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
709 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
710 
711 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
712 {
713 	struct sci_port *s = to_sci_port(port);
714 
715 	/*
716 	 * Use port-specific handler if provided.
717 	 */
718 	if (s->cfg->ops && s->cfg->ops->init_pins) {
719 		s->cfg->ops->init_pins(port, cflag);
720 		return;
721 	}
722 
723 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
724 		u16 data = serial_port_in(port, SCPDR);
725 		u16 ctrl = serial_port_in(port, SCPCR);
726 
727 		/* Enable RXD and TXD pin functions */
728 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
729 		if (to_sci_port(port)->has_rtscts) {
730 			/* RTS# is output, active low, unless autorts */
731 			if (!(port->mctrl & TIOCM_RTS)) {
732 				ctrl |= SCPCR_RTSC;
733 				data |= SCPDR_RTSD;
734 			} else if (!s->autorts) {
735 				ctrl |= SCPCR_RTSC;
736 				data &= ~SCPDR_RTSD;
737 			} else {
738 				/* Enable RTS# pin function */
739 				ctrl &= ~SCPCR_RTSC;
740 			}
741 			/* Enable CTS# pin function */
742 			ctrl &= ~SCPCR_CTSC;
743 		}
744 		serial_port_out(port, SCPDR, data);
745 		serial_port_out(port, SCPCR, ctrl);
746 	} else if (sci_getreg(port, SCSPTR)->size) {
747 		u16 status = serial_port_in(port, SCSPTR);
748 
749 		/* RTS# is always output; and active low, unless autorts */
750 		status |= SCSPTR_RTSIO;
751 		if (!(port->mctrl & TIOCM_RTS))
752 			status |= SCSPTR_RTSDT;
753 		else if (!s->autorts)
754 			status &= ~SCSPTR_RTSDT;
755 		/* CTS# and SCK are inputs */
756 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
757 		serial_port_out(port, SCSPTR, status);
758 	}
759 }
760 
761 static int sci_txfill(struct uart_port *port)
762 {
763 	struct sci_port *s = to_sci_port(port);
764 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
765 	const struct plat_sci_reg *reg;
766 
767 	reg = sci_getreg(port, SCTFDR);
768 	if (reg->size)
769 		return serial_port_in(port, SCTFDR) & fifo_mask;
770 
771 	reg = sci_getreg(port, SCFDR);
772 	if (reg->size)
773 		return serial_port_in(port, SCFDR) >> 8;
774 
775 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
776 }
777 
778 static int sci_txroom(struct uart_port *port)
779 {
780 	return port->fifosize - sci_txfill(port);
781 }
782 
783 static int sci_rxfill(struct uart_port *port)
784 {
785 	struct sci_port *s = to_sci_port(port);
786 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
787 	const struct plat_sci_reg *reg;
788 
789 	reg = sci_getreg(port, SCRFDR);
790 	if (reg->size)
791 		return serial_port_in(port, SCRFDR) & fifo_mask;
792 
793 	reg = sci_getreg(port, SCFDR);
794 	if (reg->size)
795 		return serial_port_in(port, SCFDR) & fifo_mask;
796 
797 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
798 }
799 
800 /* ********************************************************************** *
801  *                   the interrupt related routines                       *
802  * ********************************************************************** */
803 
804 static void sci_transmit_chars(struct uart_port *port)
805 {
806 	struct circ_buf *xmit = &port->state->xmit;
807 	unsigned int stopped = uart_tx_stopped(port);
808 	unsigned short status;
809 	unsigned short ctrl;
810 	int count;
811 
812 	status = serial_port_in(port, SCxSR);
813 	if (!(status & SCxSR_TDxE(port))) {
814 		ctrl = serial_port_in(port, SCSCR);
815 		if (uart_circ_empty(xmit))
816 			ctrl &= ~SCSCR_TIE;
817 		else
818 			ctrl |= SCSCR_TIE;
819 		serial_port_out(port, SCSCR, ctrl);
820 		return;
821 	}
822 
823 	count = sci_txroom(port);
824 
825 	do {
826 		unsigned char c;
827 
828 		if (port->x_char) {
829 			c = port->x_char;
830 			port->x_char = 0;
831 		} else if (!uart_circ_empty(xmit) && !stopped) {
832 			c = xmit->buf[xmit->tail];
833 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
834 		} else {
835 			break;
836 		}
837 
838 		serial_port_out(port, SCxTDR, c);
839 
840 		port->icount.tx++;
841 	} while (--count > 0);
842 
843 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
844 
845 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
846 		uart_write_wakeup(port);
847 	if (uart_circ_empty(xmit))
848 		sci_stop_tx(port);
849 
850 }
851 
852 static void sci_receive_chars(struct uart_port *port)
853 {
854 	struct tty_port *tport = &port->state->port;
855 	int i, count, copied = 0;
856 	unsigned short status;
857 	unsigned char flag;
858 
859 	status = serial_port_in(port, SCxSR);
860 	if (!(status & SCxSR_RDxF(port)))
861 		return;
862 
863 	while (1) {
864 		/* Don't copy more bytes than there is room for in the buffer */
865 		count = tty_buffer_request_room(tport, sci_rxfill(port));
866 
867 		/* If for any reason we can't copy more data, we're done! */
868 		if (count == 0)
869 			break;
870 
871 		if (port->type == PORT_SCI) {
872 			char c = serial_port_in(port, SCxRDR);
873 			if (uart_handle_sysrq_char(port, c))
874 				count = 0;
875 			else
876 				tty_insert_flip_char(tport, c, TTY_NORMAL);
877 		} else {
878 			for (i = 0; i < count; i++) {
879 				char c;
880 
881 				if (port->type == PORT_SCIF ||
882 				    port->type == PORT_HSCIF) {
883 					status = serial_port_in(port, SCxSR);
884 					c = serial_port_in(port, SCxRDR);
885 				} else {
886 					c = serial_port_in(port, SCxRDR);
887 					status = serial_port_in(port, SCxSR);
888 				}
889 				if (uart_handle_sysrq_char(port, c)) {
890 					count--; i--;
891 					continue;
892 				}
893 
894 				/* Store data and status */
895 				if (status & SCxSR_FER(port)) {
896 					flag = TTY_FRAME;
897 					port->icount.frame++;
898 					dev_notice(port->dev, "frame error\n");
899 				} else if (status & SCxSR_PER(port)) {
900 					flag = TTY_PARITY;
901 					port->icount.parity++;
902 					dev_notice(port->dev, "parity error\n");
903 				} else
904 					flag = TTY_NORMAL;
905 
906 				tty_insert_flip_char(tport, c, flag);
907 			}
908 		}
909 
910 		serial_port_in(port, SCxSR); /* dummy read */
911 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
912 
913 		copied += count;
914 		port->icount.rx += count;
915 	}
916 
917 	if (copied) {
918 		/* Tell the rest of the system the news. New characters! */
919 		tty_flip_buffer_push(tport);
920 	} else {
921 		/* TTY buffers full; read from RX reg to prevent lockup */
922 		serial_port_in(port, SCxRDR);
923 		serial_port_in(port, SCxSR); /* dummy read */
924 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
925 	}
926 }
927 
928 static int sci_handle_errors(struct uart_port *port)
929 {
930 	int copied = 0;
931 	unsigned short status = serial_port_in(port, SCxSR);
932 	struct tty_port *tport = &port->state->port;
933 	struct sci_port *s = to_sci_port(port);
934 
935 	/* Handle overruns */
936 	if (status & s->params->overrun_mask) {
937 		port->icount.overrun++;
938 
939 		/* overrun error */
940 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
941 			copied++;
942 
943 		dev_notice(port->dev, "overrun error\n");
944 	}
945 
946 	if (status & SCxSR_FER(port)) {
947 		/* frame error */
948 		port->icount.frame++;
949 
950 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
951 			copied++;
952 
953 		dev_notice(port->dev, "frame error\n");
954 	}
955 
956 	if (status & SCxSR_PER(port)) {
957 		/* parity error */
958 		port->icount.parity++;
959 
960 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
961 			copied++;
962 
963 		dev_notice(port->dev, "parity error\n");
964 	}
965 
966 	if (copied)
967 		tty_flip_buffer_push(tport);
968 
969 	return copied;
970 }
971 
972 static int sci_handle_fifo_overrun(struct uart_port *port)
973 {
974 	struct tty_port *tport = &port->state->port;
975 	struct sci_port *s = to_sci_port(port);
976 	const struct plat_sci_reg *reg;
977 	int copied = 0;
978 	u16 status;
979 
980 	reg = sci_getreg(port, s->params->overrun_reg);
981 	if (!reg->size)
982 		return 0;
983 
984 	status = serial_port_in(port, s->params->overrun_reg);
985 	if (status & s->params->overrun_mask) {
986 		status &= ~s->params->overrun_mask;
987 		serial_port_out(port, s->params->overrun_reg, status);
988 
989 		port->icount.overrun++;
990 
991 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
992 		tty_flip_buffer_push(tport);
993 
994 		dev_dbg(port->dev, "overrun error\n");
995 		copied++;
996 	}
997 
998 	return copied;
999 }
1000 
1001 static int sci_handle_breaks(struct uart_port *port)
1002 {
1003 	int copied = 0;
1004 	unsigned short status = serial_port_in(port, SCxSR);
1005 	struct tty_port *tport = &port->state->port;
1006 
1007 	if (uart_handle_break(port))
1008 		return 0;
1009 
1010 	if (status & SCxSR_BRK(port)) {
1011 		port->icount.brk++;
1012 
1013 		/* Notify of BREAK */
1014 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1015 			copied++;
1016 
1017 		dev_dbg(port->dev, "BREAK detected\n");
1018 	}
1019 
1020 	if (copied)
1021 		tty_flip_buffer_push(tport);
1022 
1023 	copied += sci_handle_fifo_overrun(port);
1024 
1025 	return copied;
1026 }
1027 
1028 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1029 {
1030 	unsigned int bits;
1031 
1032 	if (rx_trig >= port->fifosize)
1033 		rx_trig = port->fifosize - 1;
1034 	if (rx_trig < 1)
1035 		rx_trig = 1;
1036 
1037 	/* HSCIF can be set to an arbitrary level. */
1038 	if (sci_getreg(port, HSRTRGR)->size) {
1039 		serial_port_out(port, HSRTRGR, rx_trig);
1040 		return rx_trig;
1041 	}
1042 
1043 	switch (port->type) {
1044 	case PORT_SCIF:
1045 		if (rx_trig < 4) {
1046 			bits = 0;
1047 			rx_trig = 1;
1048 		} else if (rx_trig < 8) {
1049 			bits = SCFCR_RTRG0;
1050 			rx_trig = 4;
1051 		} else if (rx_trig < 14) {
1052 			bits = SCFCR_RTRG1;
1053 			rx_trig = 8;
1054 		} else {
1055 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1056 			rx_trig = 14;
1057 		}
1058 		break;
1059 	case PORT_SCIFA:
1060 	case PORT_SCIFB:
1061 		if (rx_trig < 16) {
1062 			bits = 0;
1063 			rx_trig = 1;
1064 		} else if (rx_trig < 32) {
1065 			bits = SCFCR_RTRG0;
1066 			rx_trig = 16;
1067 		} else if (rx_trig < 48) {
1068 			bits = SCFCR_RTRG1;
1069 			rx_trig = 32;
1070 		} else {
1071 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1072 			rx_trig = 48;
1073 		}
1074 		break;
1075 	default:
1076 		WARN(1, "unknown FIFO configuration");
1077 		return 1;
1078 	}
1079 
1080 	serial_port_out(port, SCFCR,
1081 		(serial_port_in(port, SCFCR) &
1082 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1083 
1084 	return rx_trig;
1085 }
1086 
1087 static int scif_rtrg_enabled(struct uart_port *port)
1088 {
1089 	if (sci_getreg(port, HSRTRGR)->size)
1090 		return serial_port_in(port, HSRTRGR) != 0;
1091 	else
1092 		return (serial_port_in(port, SCFCR) &
1093 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1094 }
1095 
1096 static void rx_fifo_timer_fn(struct timer_list *t)
1097 {
1098 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1099 	struct uart_port *port = &s->port;
1100 
1101 	dev_dbg(port->dev, "Rx timed out\n");
1102 	scif_set_rtrg(port, 1);
1103 }
1104 
1105 static ssize_t rx_fifo_trigger_show(struct device *dev,
1106 				    struct device_attribute *attr, char *buf)
1107 {
1108 	struct uart_port *port = dev_get_drvdata(dev);
1109 	struct sci_port *sci = to_sci_port(port);
1110 
1111 	return sprintf(buf, "%d\n", sci->rx_trigger);
1112 }
1113 
1114 static ssize_t rx_fifo_trigger_store(struct device *dev,
1115 				     struct device_attribute *attr,
1116 				     const char *buf, size_t count)
1117 {
1118 	struct uart_port *port = dev_get_drvdata(dev);
1119 	struct sci_port *sci = to_sci_port(port);
1120 	int ret;
1121 	long r;
1122 
1123 	ret = kstrtol(buf, 0, &r);
1124 	if (ret)
1125 		return ret;
1126 
1127 	sci->rx_trigger = scif_set_rtrg(port, r);
1128 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1129 		scif_set_rtrg(port, 1);
1130 
1131 	return count;
1132 }
1133 
1134 static DEVICE_ATTR_RW(rx_fifo_trigger);
1135 
1136 static ssize_t rx_fifo_timeout_show(struct device *dev,
1137 			       struct device_attribute *attr,
1138 			       char *buf)
1139 {
1140 	struct uart_port *port = dev_get_drvdata(dev);
1141 	struct sci_port *sci = to_sci_port(port);
1142 	int v;
1143 
1144 	if (port->type == PORT_HSCIF)
1145 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1146 	else
1147 		v = sci->rx_fifo_timeout;
1148 
1149 	return sprintf(buf, "%d\n", v);
1150 }
1151 
1152 static ssize_t rx_fifo_timeout_store(struct device *dev,
1153 				struct device_attribute *attr,
1154 				const char *buf,
1155 				size_t count)
1156 {
1157 	struct uart_port *port = dev_get_drvdata(dev);
1158 	struct sci_port *sci = to_sci_port(port);
1159 	int ret;
1160 	long r;
1161 
1162 	ret = kstrtol(buf, 0, &r);
1163 	if (ret)
1164 		return ret;
1165 
1166 	if (port->type == PORT_HSCIF) {
1167 		if (r < 0 || r > 3)
1168 			return -EINVAL;
1169 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1170 	} else {
1171 		sci->rx_fifo_timeout = r;
1172 		scif_set_rtrg(port, 1);
1173 		if (r > 0)
1174 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1175 	}
1176 
1177 	return count;
1178 }
1179 
1180 static DEVICE_ATTR_RW(rx_fifo_timeout);
1181 
1182 
1183 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1184 static void sci_dma_tx_complete(void *arg)
1185 {
1186 	struct sci_port *s = arg;
1187 	struct uart_port *port = &s->port;
1188 	struct circ_buf *xmit = &port->state->xmit;
1189 	unsigned long flags;
1190 
1191 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1192 
1193 	spin_lock_irqsave(&port->lock, flags);
1194 
1195 	xmit->tail += s->tx_dma_len;
1196 	xmit->tail &= UART_XMIT_SIZE - 1;
1197 
1198 	port->icount.tx += s->tx_dma_len;
1199 
1200 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1201 		uart_write_wakeup(port);
1202 
1203 	if (!uart_circ_empty(xmit)) {
1204 		s->cookie_tx = 0;
1205 		schedule_work(&s->work_tx);
1206 	} else {
1207 		s->cookie_tx = -EINVAL;
1208 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1209 			u16 ctrl = serial_port_in(port, SCSCR);
1210 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1211 		}
1212 	}
1213 
1214 	spin_unlock_irqrestore(&port->lock, flags);
1215 }
1216 
1217 /* Locking: called with port lock held */
1218 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1219 {
1220 	struct uart_port *port = &s->port;
1221 	struct tty_port *tport = &port->state->port;
1222 	int copied;
1223 
1224 	copied = tty_insert_flip_string(tport, buf, count);
1225 	if (copied < count)
1226 		port->icount.buf_overrun++;
1227 
1228 	port->icount.rx += copied;
1229 
1230 	return copied;
1231 }
1232 
1233 static int sci_dma_rx_find_active(struct sci_port *s)
1234 {
1235 	unsigned int i;
1236 
1237 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1238 		if (s->active_rx == s->cookie_rx[i])
1239 			return i;
1240 
1241 	return -1;
1242 }
1243 
1244 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1245 {
1246 	unsigned int i;
1247 
1248 	s->chan_rx = NULL;
1249 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1250 		s->cookie_rx[i] = -EINVAL;
1251 	s->active_rx = 0;
1252 }
1253 
1254 static void sci_dma_rx_release(struct sci_port *s)
1255 {
1256 	struct dma_chan *chan = s->chan_rx_saved;
1257 
1258 	s->chan_rx_saved = NULL;
1259 	sci_dma_rx_chan_invalidate(s);
1260 	dmaengine_terminate_sync(chan);
1261 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1262 			  sg_dma_address(&s->sg_rx[0]));
1263 	dma_release_channel(chan);
1264 }
1265 
1266 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1267 {
1268 	long sec = usec / 1000000;
1269 	long nsec = (usec % 1000000) * 1000;
1270 	ktime_t t = ktime_set(sec, nsec);
1271 
1272 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1273 }
1274 
1275 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1276 {
1277 	struct uart_port *port = &s->port;
1278 	u16 scr;
1279 
1280 	/* Direct new serial port interrupts back to CPU */
1281 	scr = serial_port_in(port, SCSCR);
1282 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1283 		scr &= ~SCSCR_RDRQE;
1284 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1285 	}
1286 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1287 }
1288 
1289 static void sci_dma_rx_complete(void *arg)
1290 {
1291 	struct sci_port *s = arg;
1292 	struct dma_chan *chan = s->chan_rx;
1293 	struct uart_port *port = &s->port;
1294 	struct dma_async_tx_descriptor *desc;
1295 	unsigned long flags;
1296 	int active, count = 0;
1297 
1298 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1299 		s->active_rx);
1300 
1301 	spin_lock_irqsave(&port->lock, flags);
1302 
1303 	active = sci_dma_rx_find_active(s);
1304 	if (active >= 0)
1305 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1306 
1307 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1308 
1309 	if (count)
1310 		tty_flip_buffer_push(&port->state->port);
1311 
1312 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1313 				       DMA_DEV_TO_MEM,
1314 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1315 	if (!desc)
1316 		goto fail;
1317 
1318 	desc->callback = sci_dma_rx_complete;
1319 	desc->callback_param = s;
1320 	s->cookie_rx[active] = dmaengine_submit(desc);
1321 	if (dma_submit_error(s->cookie_rx[active]))
1322 		goto fail;
1323 
1324 	s->active_rx = s->cookie_rx[!active];
1325 
1326 	dma_async_issue_pending(chan);
1327 
1328 	spin_unlock_irqrestore(&port->lock, flags);
1329 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1330 		__func__, s->cookie_rx[active], active, s->active_rx);
1331 	return;
1332 
1333 fail:
1334 	spin_unlock_irqrestore(&port->lock, flags);
1335 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1336 	/* Switch to PIO */
1337 	spin_lock_irqsave(&port->lock, flags);
1338 	dmaengine_terminate_async(chan);
1339 	sci_dma_rx_chan_invalidate(s);
1340 	sci_dma_rx_reenable_irq(s);
1341 	spin_unlock_irqrestore(&port->lock, flags);
1342 }
1343 
1344 static void sci_dma_tx_release(struct sci_port *s)
1345 {
1346 	struct dma_chan *chan = s->chan_tx_saved;
1347 
1348 	cancel_work_sync(&s->work_tx);
1349 	s->chan_tx_saved = s->chan_tx = NULL;
1350 	s->cookie_tx = -EINVAL;
1351 	dmaengine_terminate_sync(chan);
1352 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1353 			 DMA_TO_DEVICE);
1354 	dma_release_channel(chan);
1355 }
1356 
1357 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1358 {
1359 	struct dma_chan *chan = s->chan_rx;
1360 	struct uart_port *port = &s->port;
1361 	unsigned long flags;
1362 	int i;
1363 
1364 	for (i = 0; i < 2; i++) {
1365 		struct scatterlist *sg = &s->sg_rx[i];
1366 		struct dma_async_tx_descriptor *desc;
1367 
1368 		desc = dmaengine_prep_slave_sg(chan,
1369 			sg, 1, DMA_DEV_TO_MEM,
1370 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1371 		if (!desc)
1372 			goto fail;
1373 
1374 		desc->callback = sci_dma_rx_complete;
1375 		desc->callback_param = s;
1376 		s->cookie_rx[i] = dmaengine_submit(desc);
1377 		if (dma_submit_error(s->cookie_rx[i]))
1378 			goto fail;
1379 
1380 	}
1381 
1382 	s->active_rx = s->cookie_rx[0];
1383 
1384 	dma_async_issue_pending(chan);
1385 	return 0;
1386 
1387 fail:
1388 	/* Switch to PIO */
1389 	if (!port_lock_held)
1390 		spin_lock_irqsave(&port->lock, flags);
1391 	if (i)
1392 		dmaengine_terminate_async(chan);
1393 	sci_dma_rx_chan_invalidate(s);
1394 	sci_start_rx(port);
1395 	if (!port_lock_held)
1396 		spin_unlock_irqrestore(&port->lock, flags);
1397 	return -EAGAIN;
1398 }
1399 
1400 static void sci_dma_tx_work_fn(struct work_struct *work)
1401 {
1402 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1403 	struct dma_async_tx_descriptor *desc;
1404 	struct dma_chan *chan = s->chan_tx;
1405 	struct uart_port *port = &s->port;
1406 	struct circ_buf *xmit = &port->state->xmit;
1407 	unsigned long flags;
1408 	dma_addr_t buf;
1409 	int head, tail;
1410 
1411 	/*
1412 	 * DMA is idle now.
1413 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1414 	 * offsets and lengths. Since it is a circular buffer, we have to
1415 	 * transmit till the end, and then the rest. Take the port lock to get a
1416 	 * consistent xmit buffer state.
1417 	 */
1418 	spin_lock_irq(&port->lock);
1419 	head = xmit->head;
1420 	tail = xmit->tail;
1421 	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1422 	s->tx_dma_len = min_t(unsigned int,
1423 		CIRC_CNT(head, tail, UART_XMIT_SIZE),
1424 		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1425 	if (!s->tx_dma_len) {
1426 		/* Transmit buffer has been flushed */
1427 		spin_unlock_irq(&port->lock);
1428 		return;
1429 	}
1430 
1431 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1432 					   DMA_MEM_TO_DEV,
1433 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1434 	if (!desc) {
1435 		spin_unlock_irq(&port->lock);
1436 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1437 		goto switch_to_pio;
1438 	}
1439 
1440 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1441 				   DMA_TO_DEVICE);
1442 
1443 	desc->callback = sci_dma_tx_complete;
1444 	desc->callback_param = s;
1445 	s->cookie_tx = dmaengine_submit(desc);
1446 	if (dma_submit_error(s->cookie_tx)) {
1447 		spin_unlock_irq(&port->lock);
1448 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1449 		goto switch_to_pio;
1450 	}
1451 
1452 	spin_unlock_irq(&port->lock);
1453 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1454 		__func__, xmit->buf, tail, head, s->cookie_tx);
1455 
1456 	dma_async_issue_pending(chan);
1457 	return;
1458 
1459 switch_to_pio:
1460 	spin_lock_irqsave(&port->lock, flags);
1461 	s->chan_tx = NULL;
1462 	sci_start_tx(port);
1463 	spin_unlock_irqrestore(&port->lock, flags);
1464 	return;
1465 }
1466 
1467 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1468 {
1469 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1470 	struct dma_chan *chan = s->chan_rx;
1471 	struct uart_port *port = &s->port;
1472 	struct dma_tx_state state;
1473 	enum dma_status status;
1474 	unsigned long flags;
1475 	unsigned int read;
1476 	int active, count;
1477 
1478 	dev_dbg(port->dev, "DMA Rx timed out\n");
1479 
1480 	spin_lock_irqsave(&port->lock, flags);
1481 
1482 	active = sci_dma_rx_find_active(s);
1483 	if (active < 0) {
1484 		spin_unlock_irqrestore(&port->lock, flags);
1485 		return HRTIMER_NORESTART;
1486 	}
1487 
1488 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1489 	if (status == DMA_COMPLETE) {
1490 		spin_unlock_irqrestore(&port->lock, flags);
1491 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1492 			s->active_rx, active);
1493 
1494 		/* Let packet complete handler take care of the packet */
1495 		return HRTIMER_NORESTART;
1496 	}
1497 
1498 	dmaengine_pause(chan);
1499 
1500 	/*
1501 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1502 	 * data keeps on coming until transaction is complete so check
1503 	 * for DMA_COMPLETE again
1504 	 * Let packet complete handler take care of the packet
1505 	 */
1506 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1507 	if (status == DMA_COMPLETE) {
1508 		spin_unlock_irqrestore(&port->lock, flags);
1509 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1510 		return HRTIMER_NORESTART;
1511 	}
1512 
1513 	/* Handle incomplete DMA receive */
1514 	dmaengine_terminate_async(s->chan_rx);
1515 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1516 
1517 	if (read) {
1518 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1519 		if (count)
1520 			tty_flip_buffer_push(&port->state->port);
1521 	}
1522 
1523 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1524 		sci_dma_rx_submit(s, true);
1525 
1526 	sci_dma_rx_reenable_irq(s);
1527 
1528 	spin_unlock_irqrestore(&port->lock, flags);
1529 
1530 	return HRTIMER_NORESTART;
1531 }
1532 
1533 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1534 					     enum dma_transfer_direction dir)
1535 {
1536 	struct dma_chan *chan;
1537 	struct dma_slave_config cfg;
1538 	int ret;
1539 
1540 	chan = dma_request_slave_channel(port->dev,
1541 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1542 	if (!chan) {
1543 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1544 		return NULL;
1545 	}
1546 
1547 	memset(&cfg, 0, sizeof(cfg));
1548 	cfg.direction = dir;
1549 	if (dir == DMA_MEM_TO_DEV) {
1550 		cfg.dst_addr = port->mapbase +
1551 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1552 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1553 	} else {
1554 		cfg.src_addr = port->mapbase +
1555 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1556 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1557 	}
1558 
1559 	ret = dmaengine_slave_config(chan, &cfg);
1560 	if (ret) {
1561 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1562 		dma_release_channel(chan);
1563 		return NULL;
1564 	}
1565 
1566 	return chan;
1567 }
1568 
1569 static void sci_request_dma(struct uart_port *port)
1570 {
1571 	struct sci_port *s = to_sci_port(port);
1572 	struct dma_chan *chan;
1573 
1574 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1575 
1576 	/*
1577 	 * DMA on console may interfere with Kernel log messages which use
1578 	 * plain putchar(). So, simply don't use it with a console.
1579 	 */
1580 	if (uart_console(port))
1581 		return;
1582 
1583 	if (!port->dev->of_node)
1584 		return;
1585 
1586 	s->cookie_tx = -EINVAL;
1587 
1588 	/*
1589 	 * Don't request a dma channel if no channel was specified
1590 	 * in the device tree.
1591 	 */
1592 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1593 		return;
1594 
1595 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1596 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1597 	if (chan) {
1598 		/* UART circular tx buffer is an aligned page. */
1599 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1600 						port->state->xmit.buf,
1601 						UART_XMIT_SIZE,
1602 						DMA_TO_DEVICE);
1603 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1604 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1605 			dma_release_channel(chan);
1606 		} else {
1607 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1608 				__func__, UART_XMIT_SIZE,
1609 				port->state->xmit.buf, &s->tx_dma_addr);
1610 
1611 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1612 			s->chan_tx_saved = s->chan_tx = chan;
1613 		}
1614 	}
1615 
1616 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1617 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1618 	if (chan) {
1619 		unsigned int i;
1620 		dma_addr_t dma;
1621 		void *buf;
1622 
1623 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1624 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1625 					 &dma, GFP_KERNEL);
1626 		if (!buf) {
1627 			dev_warn(port->dev,
1628 				 "Failed to allocate Rx dma buffer, using PIO\n");
1629 			dma_release_channel(chan);
1630 			return;
1631 		}
1632 
1633 		for (i = 0; i < 2; i++) {
1634 			struct scatterlist *sg = &s->sg_rx[i];
1635 
1636 			sg_init_table(sg, 1);
1637 			s->rx_buf[i] = buf;
1638 			sg_dma_address(sg) = dma;
1639 			sg_dma_len(sg) = s->buf_len_rx;
1640 
1641 			buf += s->buf_len_rx;
1642 			dma += s->buf_len_rx;
1643 		}
1644 
1645 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1646 		s->rx_timer.function = sci_dma_rx_timer_fn;
1647 
1648 		s->chan_rx_saved = s->chan_rx = chan;
1649 
1650 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1651 			sci_dma_rx_submit(s, false);
1652 	}
1653 }
1654 
1655 static void sci_free_dma(struct uart_port *port)
1656 {
1657 	struct sci_port *s = to_sci_port(port);
1658 
1659 	if (s->chan_tx_saved)
1660 		sci_dma_tx_release(s);
1661 	if (s->chan_rx_saved)
1662 		sci_dma_rx_release(s);
1663 }
1664 
1665 static void sci_flush_buffer(struct uart_port *port)
1666 {
1667 	struct sci_port *s = to_sci_port(port);
1668 
1669 	/*
1670 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1671 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1672 	 * pending transfers
1673 	 */
1674 	s->tx_dma_len = 0;
1675 	if (s->chan_tx) {
1676 		dmaengine_terminate_async(s->chan_tx);
1677 		s->cookie_tx = -EINVAL;
1678 	}
1679 }
1680 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1681 static inline void sci_request_dma(struct uart_port *port)
1682 {
1683 }
1684 
1685 static inline void sci_free_dma(struct uart_port *port)
1686 {
1687 }
1688 
1689 #define sci_flush_buffer	NULL
1690 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1691 
1692 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1693 {
1694 	struct uart_port *port = ptr;
1695 	struct sci_port *s = to_sci_port(port);
1696 
1697 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1698 	if (s->chan_rx) {
1699 		u16 scr = serial_port_in(port, SCSCR);
1700 		u16 ssr = serial_port_in(port, SCxSR);
1701 
1702 		/* Disable future Rx interrupts */
1703 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1704 			disable_irq_nosync(irq);
1705 			scr |= SCSCR_RDRQE;
1706 		} else {
1707 			if (sci_dma_rx_submit(s, false) < 0)
1708 				goto handle_pio;
1709 
1710 			scr &= ~SCSCR_RIE;
1711 		}
1712 		serial_port_out(port, SCSCR, scr);
1713 		/* Clear current interrupt */
1714 		serial_port_out(port, SCxSR,
1715 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1716 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1717 			jiffies, s->rx_timeout);
1718 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1719 
1720 		return IRQ_HANDLED;
1721 	}
1722 
1723 handle_pio:
1724 #endif
1725 
1726 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1727 		if (!scif_rtrg_enabled(port))
1728 			scif_set_rtrg(port, s->rx_trigger);
1729 
1730 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1731 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1732 	}
1733 
1734 	/* I think sci_receive_chars has to be called irrespective
1735 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1736 	 * to be disabled?
1737 	 */
1738 	sci_receive_chars(port);
1739 
1740 	return IRQ_HANDLED;
1741 }
1742 
1743 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1744 {
1745 	struct uart_port *port = ptr;
1746 	unsigned long flags;
1747 
1748 	spin_lock_irqsave(&port->lock, flags);
1749 	sci_transmit_chars(port);
1750 	spin_unlock_irqrestore(&port->lock, flags);
1751 
1752 	return IRQ_HANDLED;
1753 }
1754 
1755 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1756 {
1757 	struct uart_port *port = ptr;
1758 
1759 	/* Handle BREAKs */
1760 	sci_handle_breaks(port);
1761 
1762 	/* drop invalid character received before break was detected */
1763 	serial_port_in(port, SCxRDR);
1764 
1765 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1766 
1767 	return IRQ_HANDLED;
1768 }
1769 
1770 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1771 {
1772 	struct uart_port *port = ptr;
1773 	struct sci_port *s = to_sci_port(port);
1774 
1775 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1776 		/* Break and Error interrupts are muxed */
1777 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1778 
1779 		/* Break Interrupt */
1780 		if (ssr_status & SCxSR_BRK(port))
1781 			sci_br_interrupt(irq, ptr);
1782 
1783 		/* Break only? */
1784 		if (!(ssr_status & SCxSR_ERRORS(port)))
1785 			return IRQ_HANDLED;
1786 	}
1787 
1788 	/* Handle errors */
1789 	if (port->type == PORT_SCI) {
1790 		if (sci_handle_errors(port)) {
1791 			/* discard character in rx buffer */
1792 			serial_port_in(port, SCxSR);
1793 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1794 		}
1795 	} else {
1796 		sci_handle_fifo_overrun(port);
1797 		if (!s->chan_rx)
1798 			sci_receive_chars(port);
1799 	}
1800 
1801 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1802 
1803 	/* Kick the transmission */
1804 	if (!s->chan_tx)
1805 		sci_tx_interrupt(irq, ptr);
1806 
1807 	return IRQ_HANDLED;
1808 }
1809 
1810 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1811 {
1812 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1813 	struct uart_port *port = ptr;
1814 	struct sci_port *s = to_sci_port(port);
1815 	irqreturn_t ret = IRQ_NONE;
1816 
1817 	ssr_status = serial_port_in(port, SCxSR);
1818 	scr_status = serial_port_in(port, SCSCR);
1819 	if (s->params->overrun_reg == SCxSR)
1820 		orer_status = ssr_status;
1821 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1822 		orer_status = serial_port_in(port, s->params->overrun_reg);
1823 
1824 	err_enabled = scr_status & port_rx_irq_mask(port);
1825 
1826 	/* Tx Interrupt */
1827 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1828 	    !s->chan_tx)
1829 		ret = sci_tx_interrupt(irq, ptr);
1830 
1831 	/*
1832 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1833 	 * DR flags
1834 	 */
1835 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1836 	    (scr_status & SCSCR_RIE))
1837 		ret = sci_rx_interrupt(irq, ptr);
1838 
1839 	/* Error Interrupt */
1840 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1841 		ret = sci_er_interrupt(irq, ptr);
1842 
1843 	/* Break Interrupt */
1844 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1845 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1846 		ret = sci_br_interrupt(irq, ptr);
1847 
1848 	/* Overrun Interrupt */
1849 	if (orer_status & s->params->overrun_mask) {
1850 		sci_handle_fifo_overrun(port);
1851 		ret = IRQ_HANDLED;
1852 	}
1853 
1854 	return ret;
1855 }
1856 
1857 static const struct sci_irq_desc {
1858 	const char	*desc;
1859 	irq_handler_t	handler;
1860 } sci_irq_desc[] = {
1861 	/*
1862 	 * Split out handlers, the default case.
1863 	 */
1864 	[SCIx_ERI_IRQ] = {
1865 		.desc = "rx err",
1866 		.handler = sci_er_interrupt,
1867 	},
1868 
1869 	[SCIx_RXI_IRQ] = {
1870 		.desc = "rx full",
1871 		.handler = sci_rx_interrupt,
1872 	},
1873 
1874 	[SCIx_TXI_IRQ] = {
1875 		.desc = "tx empty",
1876 		.handler = sci_tx_interrupt,
1877 	},
1878 
1879 	[SCIx_BRI_IRQ] = {
1880 		.desc = "break",
1881 		.handler = sci_br_interrupt,
1882 	},
1883 
1884 	[SCIx_DRI_IRQ] = {
1885 		.desc = "rx ready",
1886 		.handler = sci_rx_interrupt,
1887 	},
1888 
1889 	[SCIx_TEI_IRQ] = {
1890 		.desc = "tx end",
1891 		.handler = sci_tx_interrupt,
1892 	},
1893 
1894 	/*
1895 	 * Special muxed handler.
1896 	 */
1897 	[SCIx_MUX_IRQ] = {
1898 		.desc = "mux",
1899 		.handler = sci_mpxed_interrupt,
1900 	},
1901 };
1902 
1903 static int sci_request_irq(struct sci_port *port)
1904 {
1905 	struct uart_port *up = &port->port;
1906 	int i, j, w, ret = 0;
1907 
1908 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1909 		const struct sci_irq_desc *desc;
1910 		int irq;
1911 
1912 		/* Check if already registered (muxed) */
1913 		for (w = 0; w < i; w++)
1914 			if (port->irqs[w] == port->irqs[i])
1915 				w = i + 1;
1916 		if (w > i)
1917 			continue;
1918 
1919 		if (SCIx_IRQ_IS_MUXED(port)) {
1920 			i = SCIx_MUX_IRQ;
1921 			irq = up->irq;
1922 		} else {
1923 			irq = port->irqs[i];
1924 
1925 			/*
1926 			 * Certain port types won't support all of the
1927 			 * available interrupt sources.
1928 			 */
1929 			if (unlikely(irq < 0))
1930 				continue;
1931 		}
1932 
1933 		desc = sci_irq_desc + i;
1934 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1935 					    dev_name(up->dev), desc->desc);
1936 		if (!port->irqstr[j]) {
1937 			ret = -ENOMEM;
1938 			goto out_nomem;
1939 		}
1940 
1941 		ret = request_irq(irq, desc->handler, up->irqflags,
1942 				  port->irqstr[j], port);
1943 		if (unlikely(ret)) {
1944 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1945 			goto out_noirq;
1946 		}
1947 	}
1948 
1949 	return 0;
1950 
1951 out_noirq:
1952 	while (--i >= 0)
1953 		free_irq(port->irqs[i], port);
1954 
1955 out_nomem:
1956 	while (--j >= 0)
1957 		kfree(port->irqstr[j]);
1958 
1959 	return ret;
1960 }
1961 
1962 static void sci_free_irq(struct sci_port *port)
1963 {
1964 	int i, j;
1965 
1966 	/*
1967 	 * Intentionally in reverse order so we iterate over the muxed
1968 	 * IRQ first.
1969 	 */
1970 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1971 		int irq = port->irqs[i];
1972 
1973 		/*
1974 		 * Certain port types won't support all of the available
1975 		 * interrupt sources.
1976 		 */
1977 		if (unlikely(irq < 0))
1978 			continue;
1979 
1980 		/* Check if already freed (irq was muxed) */
1981 		for (j = 0; j < i; j++)
1982 			if (port->irqs[j] == irq)
1983 				j = i + 1;
1984 		if (j > i)
1985 			continue;
1986 
1987 		free_irq(port->irqs[i], port);
1988 		kfree(port->irqstr[i]);
1989 
1990 		if (SCIx_IRQ_IS_MUXED(port)) {
1991 			/* If there's only one IRQ, we're done. */
1992 			return;
1993 		}
1994 	}
1995 }
1996 
1997 static unsigned int sci_tx_empty(struct uart_port *port)
1998 {
1999 	unsigned short status = serial_port_in(port, SCxSR);
2000 	unsigned short in_tx_fifo = sci_txfill(port);
2001 
2002 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2003 }
2004 
2005 static void sci_set_rts(struct uart_port *port, bool state)
2006 {
2007 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2008 		u16 data = serial_port_in(port, SCPDR);
2009 
2010 		/* Active low */
2011 		if (state)
2012 			data &= ~SCPDR_RTSD;
2013 		else
2014 			data |= SCPDR_RTSD;
2015 		serial_port_out(port, SCPDR, data);
2016 
2017 		/* RTS# is output */
2018 		serial_port_out(port, SCPCR,
2019 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2020 	} else if (sci_getreg(port, SCSPTR)->size) {
2021 		u16 ctrl = serial_port_in(port, SCSPTR);
2022 
2023 		/* Active low */
2024 		if (state)
2025 			ctrl &= ~SCSPTR_RTSDT;
2026 		else
2027 			ctrl |= SCSPTR_RTSDT;
2028 		serial_port_out(port, SCSPTR, ctrl);
2029 	}
2030 }
2031 
2032 static bool sci_get_cts(struct uart_port *port)
2033 {
2034 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2035 		/* Active low */
2036 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2037 	} else if (sci_getreg(port, SCSPTR)->size) {
2038 		/* Active low */
2039 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2040 	}
2041 
2042 	return true;
2043 }
2044 
2045 /*
2046  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2047  * CTS/RTS is supported in hardware by at least one port and controlled
2048  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2049  * handled via the ->init_pins() op, which is a bit of a one-way street,
2050  * lacking any ability to defer pin control -- this will later be
2051  * converted over to the GPIO framework).
2052  *
2053  * Other modes (such as loopback) are supported generically on certain
2054  * port types, but not others. For these it's sufficient to test for the
2055  * existence of the support register and simply ignore the port type.
2056  */
2057 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2058 {
2059 	struct sci_port *s = to_sci_port(port);
2060 
2061 	if (mctrl & TIOCM_LOOP) {
2062 		const struct plat_sci_reg *reg;
2063 
2064 		/*
2065 		 * Standard loopback mode for SCFCR ports.
2066 		 */
2067 		reg = sci_getreg(port, SCFCR);
2068 		if (reg->size)
2069 			serial_port_out(port, SCFCR,
2070 					serial_port_in(port, SCFCR) |
2071 					SCFCR_LOOP);
2072 	}
2073 
2074 	mctrl_gpio_set(s->gpios, mctrl);
2075 
2076 	if (!s->has_rtscts)
2077 		return;
2078 
2079 	if (!(mctrl & TIOCM_RTS)) {
2080 		/* Disable Auto RTS */
2081 		serial_port_out(port, SCFCR,
2082 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2083 
2084 		/* Clear RTS */
2085 		sci_set_rts(port, 0);
2086 	} else if (s->autorts) {
2087 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2088 			/* Enable RTS# pin function */
2089 			serial_port_out(port, SCPCR,
2090 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2091 		}
2092 
2093 		/* Enable Auto RTS */
2094 		serial_port_out(port, SCFCR,
2095 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2096 	} else {
2097 		/* Set RTS */
2098 		sci_set_rts(port, 1);
2099 	}
2100 }
2101 
2102 static unsigned int sci_get_mctrl(struct uart_port *port)
2103 {
2104 	struct sci_port *s = to_sci_port(port);
2105 	struct mctrl_gpios *gpios = s->gpios;
2106 	unsigned int mctrl = 0;
2107 
2108 	mctrl_gpio_get(gpios, &mctrl);
2109 
2110 	/*
2111 	 * CTS/RTS is handled in hardware when supported, while nothing
2112 	 * else is wired up.
2113 	 */
2114 	if (s->autorts) {
2115 		if (sci_get_cts(port))
2116 			mctrl |= TIOCM_CTS;
2117 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2118 		mctrl |= TIOCM_CTS;
2119 	}
2120 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2121 		mctrl |= TIOCM_DSR;
2122 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2123 		mctrl |= TIOCM_CAR;
2124 
2125 	return mctrl;
2126 }
2127 
2128 static void sci_enable_ms(struct uart_port *port)
2129 {
2130 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2131 }
2132 
2133 static void sci_break_ctl(struct uart_port *port, int break_state)
2134 {
2135 	unsigned short scscr, scsptr;
2136 	unsigned long flags;
2137 
2138 	/* check whether the port has SCSPTR */
2139 	if (!sci_getreg(port, SCSPTR)->size) {
2140 		/*
2141 		 * Not supported by hardware. Most parts couple break and rx
2142 		 * interrupts together, with break detection always enabled.
2143 		 */
2144 		return;
2145 	}
2146 
2147 	spin_lock_irqsave(&port->lock, flags);
2148 	scsptr = serial_port_in(port, SCSPTR);
2149 	scscr = serial_port_in(port, SCSCR);
2150 
2151 	if (break_state == -1) {
2152 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2153 		scscr &= ~SCSCR_TE;
2154 	} else {
2155 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2156 		scscr |= SCSCR_TE;
2157 	}
2158 
2159 	serial_port_out(port, SCSPTR, scsptr);
2160 	serial_port_out(port, SCSCR, scscr);
2161 	spin_unlock_irqrestore(&port->lock, flags);
2162 }
2163 
2164 static int sci_startup(struct uart_port *port)
2165 {
2166 	struct sci_port *s = to_sci_port(port);
2167 	int ret;
2168 
2169 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2170 
2171 	sci_request_dma(port);
2172 
2173 	ret = sci_request_irq(s);
2174 	if (unlikely(ret < 0)) {
2175 		sci_free_dma(port);
2176 		return ret;
2177 	}
2178 
2179 	return 0;
2180 }
2181 
2182 static void sci_shutdown(struct uart_port *port)
2183 {
2184 	struct sci_port *s = to_sci_port(port);
2185 	unsigned long flags;
2186 	u16 scr;
2187 
2188 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2189 
2190 	s->autorts = false;
2191 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2192 
2193 	spin_lock_irqsave(&port->lock, flags);
2194 	sci_stop_rx(port);
2195 	sci_stop_tx(port);
2196 	/*
2197 	 * Stop RX and TX, disable related interrupts, keep clock source
2198 	 * and HSCIF TOT bits
2199 	 */
2200 	scr = serial_port_in(port, SCSCR);
2201 	serial_port_out(port, SCSCR, scr &
2202 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2203 	spin_unlock_irqrestore(&port->lock, flags);
2204 
2205 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2206 	if (s->chan_rx_saved) {
2207 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2208 			port->line);
2209 		hrtimer_cancel(&s->rx_timer);
2210 	}
2211 #endif
2212 
2213 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2214 		del_timer_sync(&s->rx_fifo_timer);
2215 	sci_free_irq(s);
2216 	sci_free_dma(port);
2217 }
2218 
2219 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2220 			unsigned int *srr)
2221 {
2222 	unsigned long freq = s->clk_rates[SCI_SCK];
2223 	int err, min_err = INT_MAX;
2224 	unsigned int sr;
2225 
2226 	if (s->port.type != PORT_HSCIF)
2227 		freq *= 2;
2228 
2229 	for_each_sr(sr, s) {
2230 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2231 		if (abs(err) >= abs(min_err))
2232 			continue;
2233 
2234 		min_err = err;
2235 		*srr = sr - 1;
2236 
2237 		if (!err)
2238 			break;
2239 	}
2240 
2241 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2242 		*srr + 1);
2243 	return min_err;
2244 }
2245 
2246 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2247 			unsigned long freq, unsigned int *dlr,
2248 			unsigned int *srr)
2249 {
2250 	int err, min_err = INT_MAX;
2251 	unsigned int sr, dl;
2252 
2253 	if (s->port.type != PORT_HSCIF)
2254 		freq *= 2;
2255 
2256 	for_each_sr(sr, s) {
2257 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2258 		dl = clamp(dl, 1U, 65535U);
2259 
2260 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2261 		if (abs(err) >= abs(min_err))
2262 			continue;
2263 
2264 		min_err = err;
2265 		*dlr = dl;
2266 		*srr = sr - 1;
2267 
2268 		if (!err)
2269 			break;
2270 	}
2271 
2272 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2273 		min_err, *dlr, *srr + 1);
2274 	return min_err;
2275 }
2276 
2277 /* calculate sample rate, BRR, and clock select */
2278 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2279 			  unsigned int *brr, unsigned int *srr,
2280 			  unsigned int *cks)
2281 {
2282 	unsigned long freq = s->clk_rates[SCI_FCK];
2283 	unsigned int sr, br, prediv, scrate, c;
2284 	int err, min_err = INT_MAX;
2285 
2286 	if (s->port.type != PORT_HSCIF)
2287 		freq *= 2;
2288 
2289 	/*
2290 	 * Find the combination of sample rate and clock select with the
2291 	 * smallest deviation from the desired baud rate.
2292 	 * Prefer high sample rates to maximise the receive margin.
2293 	 *
2294 	 * M: Receive margin (%)
2295 	 * N: Ratio of bit rate to clock (N = sampling rate)
2296 	 * D: Clock duty (D = 0 to 1.0)
2297 	 * L: Frame length (L = 9 to 12)
2298 	 * F: Absolute value of clock frequency deviation
2299 	 *
2300 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2301 	 *      (|D - 0.5| / N * (1 + F))|
2302 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2303 	 */
2304 	for_each_sr(sr, s) {
2305 		for (c = 0; c <= 3; c++) {
2306 			/* integerized formulas from HSCIF documentation */
2307 			prediv = sr * (1 << (2 * c + 1));
2308 
2309 			/*
2310 			 * We need to calculate:
2311 			 *
2312 			 *     br = freq / (prediv * bps) clamped to [1..256]
2313 			 *     err = freq / (br * prediv) - bps
2314 			 *
2315 			 * Watch out for overflow when calculating the desired
2316 			 * sampling clock rate!
2317 			 */
2318 			if (bps > UINT_MAX / prediv)
2319 				break;
2320 
2321 			scrate = prediv * bps;
2322 			br = DIV_ROUND_CLOSEST(freq, scrate);
2323 			br = clamp(br, 1U, 256U);
2324 
2325 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2326 			if (abs(err) >= abs(min_err))
2327 				continue;
2328 
2329 			min_err = err;
2330 			*brr = br - 1;
2331 			*srr = sr - 1;
2332 			*cks = c;
2333 
2334 			if (!err)
2335 				goto found;
2336 		}
2337 	}
2338 
2339 found:
2340 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2341 		min_err, *brr, *srr + 1, *cks);
2342 	return min_err;
2343 }
2344 
2345 static void sci_reset(struct uart_port *port)
2346 {
2347 	const struct plat_sci_reg *reg;
2348 	unsigned int status;
2349 	struct sci_port *s = to_sci_port(port);
2350 
2351 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2352 
2353 	reg = sci_getreg(port, SCFCR);
2354 	if (reg->size)
2355 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2356 
2357 	sci_clear_SCxSR(port,
2358 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2359 			SCxSR_BREAK_CLEAR(port));
2360 	if (sci_getreg(port, SCLSR)->size) {
2361 		status = serial_port_in(port, SCLSR);
2362 		status &= ~(SCLSR_TO | SCLSR_ORER);
2363 		serial_port_out(port, SCLSR, status);
2364 	}
2365 
2366 	if (s->rx_trigger > 1) {
2367 		if (s->rx_fifo_timeout) {
2368 			scif_set_rtrg(port, 1);
2369 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2370 		} else {
2371 			if (port->type == PORT_SCIFA ||
2372 			    port->type == PORT_SCIFB)
2373 				scif_set_rtrg(port, 1);
2374 			else
2375 				scif_set_rtrg(port, s->rx_trigger);
2376 		}
2377 	}
2378 }
2379 
2380 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2381 			    struct ktermios *old)
2382 {
2383 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2384 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2385 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2386 	struct sci_port *s = to_sci_port(port);
2387 	const struct plat_sci_reg *reg;
2388 	int min_err = INT_MAX, err;
2389 	unsigned long max_freq = 0;
2390 	int best_clk = -1;
2391 	unsigned long flags;
2392 
2393 	if ((termios->c_cflag & CSIZE) == CS7)
2394 		smr_val |= SCSMR_CHR;
2395 	if (termios->c_cflag & PARENB)
2396 		smr_val |= SCSMR_PE;
2397 	if (termios->c_cflag & PARODD)
2398 		smr_val |= SCSMR_PE | SCSMR_ODD;
2399 	if (termios->c_cflag & CSTOPB)
2400 		smr_val |= SCSMR_STOP;
2401 
2402 	/*
2403 	 * earlyprintk comes here early on with port->uartclk set to zero.
2404 	 * the clock framework is not up and running at this point so here
2405 	 * we assume that 115200 is the maximum baud rate. please note that
2406 	 * the baud rate is not programmed during earlyprintk - it is assumed
2407 	 * that the previous boot loader has enabled required clocks and
2408 	 * setup the baud rate generator hardware for us already.
2409 	 */
2410 	if (!port->uartclk) {
2411 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2412 		goto done;
2413 	}
2414 
2415 	for (i = 0; i < SCI_NUM_CLKS; i++)
2416 		max_freq = max(max_freq, s->clk_rates[i]);
2417 
2418 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2419 	if (!baud)
2420 		goto done;
2421 
2422 	/*
2423 	 * There can be multiple sources for the sampling clock.  Find the one
2424 	 * that gives us the smallest deviation from the desired baud rate.
2425 	 */
2426 
2427 	/* Optional Undivided External Clock */
2428 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2429 	    port->type != PORT_SCIFB) {
2430 		err = sci_sck_calc(s, baud, &srr1);
2431 		if (abs(err) < abs(min_err)) {
2432 			best_clk = SCI_SCK;
2433 			scr_val = SCSCR_CKE1;
2434 			sccks = SCCKS_CKS;
2435 			min_err = err;
2436 			srr = srr1;
2437 			if (!err)
2438 				goto done;
2439 		}
2440 	}
2441 
2442 	/* Optional BRG Frequency Divided External Clock */
2443 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2444 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2445 				   &srr1);
2446 		if (abs(err) < abs(min_err)) {
2447 			best_clk = SCI_SCIF_CLK;
2448 			scr_val = SCSCR_CKE1;
2449 			sccks = 0;
2450 			min_err = err;
2451 			dl = dl1;
2452 			srr = srr1;
2453 			if (!err)
2454 				goto done;
2455 		}
2456 	}
2457 
2458 	/* Optional BRG Frequency Divided Internal Clock */
2459 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2460 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2461 				   &srr1);
2462 		if (abs(err) < abs(min_err)) {
2463 			best_clk = SCI_BRG_INT;
2464 			scr_val = SCSCR_CKE1;
2465 			sccks = SCCKS_XIN;
2466 			min_err = err;
2467 			dl = dl1;
2468 			srr = srr1;
2469 			if (!min_err)
2470 				goto done;
2471 		}
2472 	}
2473 
2474 	/* Divided Functional Clock using standard Bit Rate Register */
2475 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2476 	if (abs(err) < abs(min_err)) {
2477 		best_clk = SCI_FCK;
2478 		scr_val = 0;
2479 		min_err = err;
2480 		brr = brr1;
2481 		srr = srr1;
2482 		cks = cks1;
2483 	}
2484 
2485 done:
2486 	if (best_clk >= 0)
2487 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2488 			s->clks[best_clk], baud, min_err);
2489 
2490 	sci_port_enable(s);
2491 
2492 	/*
2493 	 * Program the optional External Baud Rate Generator (BRG) first.
2494 	 * It controls the mux to select (H)SCK or frequency divided clock.
2495 	 */
2496 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2497 		serial_port_out(port, SCDL, dl);
2498 		serial_port_out(port, SCCKS, sccks);
2499 	}
2500 
2501 	spin_lock_irqsave(&port->lock, flags);
2502 
2503 	sci_reset(port);
2504 
2505 	uart_update_timeout(port, termios->c_cflag, baud);
2506 
2507 	/* byte size and parity */
2508 	bits = tty_get_frame_size(termios->c_cflag);
2509 
2510 	if (sci_getreg(port, SEMR)->size)
2511 		serial_port_out(port, SEMR, 0);
2512 
2513 	if (best_clk >= 0) {
2514 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2515 			switch (srr + 1) {
2516 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2517 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2518 			case 11: smr_val |= SCSMR_SRC_11; break;
2519 			case 13: smr_val |= SCSMR_SRC_13; break;
2520 			case 16: smr_val |= SCSMR_SRC_16; break;
2521 			case 17: smr_val |= SCSMR_SRC_17; break;
2522 			case 19: smr_val |= SCSMR_SRC_19; break;
2523 			case 27: smr_val |= SCSMR_SRC_27; break;
2524 			}
2525 		smr_val |= cks;
2526 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2527 		serial_port_out(port, SCSMR, smr_val);
2528 		serial_port_out(port, SCBRR, brr);
2529 		if (sci_getreg(port, HSSRR)->size) {
2530 			unsigned int hssrr = srr | HSCIF_SRE;
2531 			/* Calculate deviation from intended rate at the
2532 			 * center of the last stop bit in sampling clocks.
2533 			 */
2534 			int last_stop = bits * 2 - 1;
2535 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2536 							  (int)(srr + 1),
2537 							  2 * (int)baud);
2538 
2539 			if (abs(deviation) >= 2) {
2540 				/* At least two sampling clocks off at the
2541 				 * last stop bit; we can increase the error
2542 				 * margin by shifting the sampling point.
2543 				 */
2544 				int shift = clamp(deviation / 2, -8, 7);
2545 
2546 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2547 					 HSCIF_SRHP_MASK;
2548 				hssrr |= HSCIF_SRDE;
2549 			}
2550 			serial_port_out(port, HSSRR, hssrr);
2551 		}
2552 
2553 		/* Wait one bit interval */
2554 		udelay((1000000 + (baud - 1)) / baud);
2555 	} else {
2556 		/* Don't touch the bit rate configuration */
2557 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2558 		smr_val |= serial_port_in(port, SCSMR) &
2559 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2560 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2561 		serial_port_out(port, SCSMR, smr_val);
2562 	}
2563 
2564 	sci_init_pins(port, termios->c_cflag);
2565 
2566 	port->status &= ~UPSTAT_AUTOCTS;
2567 	s->autorts = false;
2568 	reg = sci_getreg(port, SCFCR);
2569 	if (reg->size) {
2570 		unsigned short ctrl = serial_port_in(port, SCFCR);
2571 
2572 		if ((port->flags & UPF_HARD_FLOW) &&
2573 		    (termios->c_cflag & CRTSCTS)) {
2574 			/* There is no CTS interrupt to restart the hardware */
2575 			port->status |= UPSTAT_AUTOCTS;
2576 			/* MCE is enabled when RTS is raised */
2577 			s->autorts = true;
2578 		}
2579 
2580 		/*
2581 		 * As we've done a sci_reset() above, ensure we don't
2582 		 * interfere with the FIFOs while toggling MCE. As the
2583 		 * reset values could still be set, simply mask them out.
2584 		 */
2585 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2586 
2587 		serial_port_out(port, SCFCR, ctrl);
2588 	}
2589 	if (port->flags & UPF_HARD_FLOW) {
2590 		/* Refresh (Auto) RTS */
2591 		sci_set_mctrl(port, port->mctrl);
2592 	}
2593 
2594 	scr_val |= SCSCR_RE | SCSCR_TE |
2595 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2596 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2597 	if ((srr + 1 == 5) &&
2598 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2599 		/*
2600 		 * In asynchronous mode, when the sampling rate is 1/5, first
2601 		 * received data may become invalid on some SCIFA and SCIFB.
2602 		 * To avoid this problem wait more than 1 serial data time (1
2603 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2604 		 */
2605 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2606 	}
2607 
2608 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2609 	s->rx_frame = (10000 * bits) / (baud / 100);
2610 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2611 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2612 #endif
2613 
2614 	if ((termios->c_cflag & CREAD) != 0)
2615 		sci_start_rx(port);
2616 
2617 	spin_unlock_irqrestore(&port->lock, flags);
2618 
2619 	sci_port_disable(s);
2620 
2621 	if (UART_ENABLE_MS(port, termios->c_cflag))
2622 		sci_enable_ms(port);
2623 }
2624 
2625 static void sci_pm(struct uart_port *port, unsigned int state,
2626 		   unsigned int oldstate)
2627 {
2628 	struct sci_port *sci_port = to_sci_port(port);
2629 
2630 	switch (state) {
2631 	case UART_PM_STATE_OFF:
2632 		sci_port_disable(sci_port);
2633 		break;
2634 	default:
2635 		sci_port_enable(sci_port);
2636 		break;
2637 	}
2638 }
2639 
2640 static const char *sci_type(struct uart_port *port)
2641 {
2642 	switch (port->type) {
2643 	case PORT_IRDA:
2644 		return "irda";
2645 	case PORT_SCI:
2646 		return "sci";
2647 	case PORT_SCIF:
2648 		return "scif";
2649 	case PORT_SCIFA:
2650 		return "scifa";
2651 	case PORT_SCIFB:
2652 		return "scifb";
2653 	case PORT_HSCIF:
2654 		return "hscif";
2655 	}
2656 
2657 	return NULL;
2658 }
2659 
2660 static int sci_remap_port(struct uart_port *port)
2661 {
2662 	struct sci_port *sport = to_sci_port(port);
2663 
2664 	/*
2665 	 * Nothing to do if there's already an established membase.
2666 	 */
2667 	if (port->membase)
2668 		return 0;
2669 
2670 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2671 		port->membase = ioremap(port->mapbase, sport->reg_size);
2672 		if (unlikely(!port->membase)) {
2673 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2674 			return -ENXIO;
2675 		}
2676 	} else {
2677 		/*
2678 		 * For the simple (and majority of) cases where we don't
2679 		 * need to do any remapping, just cast the cookie
2680 		 * directly.
2681 		 */
2682 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2683 	}
2684 
2685 	return 0;
2686 }
2687 
2688 static void sci_release_port(struct uart_port *port)
2689 {
2690 	struct sci_port *sport = to_sci_port(port);
2691 
2692 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2693 		iounmap(port->membase);
2694 		port->membase = NULL;
2695 	}
2696 
2697 	release_mem_region(port->mapbase, sport->reg_size);
2698 }
2699 
2700 static int sci_request_port(struct uart_port *port)
2701 {
2702 	struct resource *res;
2703 	struct sci_port *sport = to_sci_port(port);
2704 	int ret;
2705 
2706 	res = request_mem_region(port->mapbase, sport->reg_size,
2707 				 dev_name(port->dev));
2708 	if (unlikely(res == NULL)) {
2709 		dev_err(port->dev, "request_mem_region failed.");
2710 		return -EBUSY;
2711 	}
2712 
2713 	ret = sci_remap_port(port);
2714 	if (unlikely(ret != 0)) {
2715 		release_resource(res);
2716 		return ret;
2717 	}
2718 
2719 	return 0;
2720 }
2721 
2722 static void sci_config_port(struct uart_port *port, int flags)
2723 {
2724 	if (flags & UART_CONFIG_TYPE) {
2725 		struct sci_port *sport = to_sci_port(port);
2726 
2727 		port->type = sport->cfg->type;
2728 		sci_request_port(port);
2729 	}
2730 }
2731 
2732 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2733 {
2734 	if (ser->baud_base < 2400)
2735 		/* No paper tape reader for Mitch.. */
2736 		return -EINVAL;
2737 
2738 	return 0;
2739 }
2740 
2741 static const struct uart_ops sci_uart_ops = {
2742 	.tx_empty	= sci_tx_empty,
2743 	.set_mctrl	= sci_set_mctrl,
2744 	.get_mctrl	= sci_get_mctrl,
2745 	.start_tx	= sci_start_tx,
2746 	.stop_tx	= sci_stop_tx,
2747 	.stop_rx	= sci_stop_rx,
2748 	.enable_ms	= sci_enable_ms,
2749 	.break_ctl	= sci_break_ctl,
2750 	.startup	= sci_startup,
2751 	.shutdown	= sci_shutdown,
2752 	.flush_buffer	= sci_flush_buffer,
2753 	.set_termios	= sci_set_termios,
2754 	.pm		= sci_pm,
2755 	.type		= sci_type,
2756 	.release_port	= sci_release_port,
2757 	.request_port	= sci_request_port,
2758 	.config_port	= sci_config_port,
2759 	.verify_port	= sci_verify_port,
2760 #ifdef CONFIG_CONSOLE_POLL
2761 	.poll_get_char	= sci_poll_get_char,
2762 	.poll_put_char	= sci_poll_put_char,
2763 #endif
2764 };
2765 
2766 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2767 {
2768 	const char *clk_names[] = {
2769 		[SCI_FCK] = "fck",
2770 		[SCI_SCK] = "sck",
2771 		[SCI_BRG_INT] = "brg_int",
2772 		[SCI_SCIF_CLK] = "scif_clk",
2773 	};
2774 	struct clk *clk;
2775 	unsigned int i;
2776 
2777 	if (sci_port->cfg->type == PORT_HSCIF)
2778 		clk_names[SCI_SCK] = "hsck";
2779 
2780 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2781 		clk = devm_clk_get(dev, clk_names[i]);
2782 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2783 			return -EPROBE_DEFER;
2784 
2785 		if (IS_ERR(clk) && i == SCI_FCK) {
2786 			/*
2787 			 * "fck" used to be called "sci_ick", and we need to
2788 			 * maintain DT backward compatibility.
2789 			 */
2790 			clk = devm_clk_get(dev, "sci_ick");
2791 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2792 				return -EPROBE_DEFER;
2793 
2794 			if (!IS_ERR(clk))
2795 				goto found;
2796 
2797 			/*
2798 			 * Not all SH platforms declare a clock lookup entry
2799 			 * for SCI devices, in which case we need to get the
2800 			 * global "peripheral_clk" clock.
2801 			 */
2802 			clk = devm_clk_get(dev, "peripheral_clk");
2803 			if (!IS_ERR(clk))
2804 				goto found;
2805 
2806 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2807 				PTR_ERR(clk));
2808 			return PTR_ERR(clk);
2809 		}
2810 
2811 found:
2812 		if (IS_ERR(clk))
2813 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2814 				PTR_ERR(clk));
2815 		else
2816 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2817 				clk, clk_get_rate(clk));
2818 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2819 	}
2820 	return 0;
2821 }
2822 
2823 static const struct sci_port_params *
2824 sci_probe_regmap(const struct plat_sci_port *cfg)
2825 {
2826 	unsigned int regtype;
2827 
2828 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2829 		return &sci_port_params[cfg->regtype];
2830 
2831 	switch (cfg->type) {
2832 	case PORT_SCI:
2833 		regtype = SCIx_SCI_REGTYPE;
2834 		break;
2835 	case PORT_IRDA:
2836 		regtype = SCIx_IRDA_REGTYPE;
2837 		break;
2838 	case PORT_SCIFA:
2839 		regtype = SCIx_SCIFA_REGTYPE;
2840 		break;
2841 	case PORT_SCIFB:
2842 		regtype = SCIx_SCIFB_REGTYPE;
2843 		break;
2844 	case PORT_SCIF:
2845 		/*
2846 		 * The SH-4 is a bit of a misnomer here, although that's
2847 		 * where this particular port layout originated. This
2848 		 * configuration (or some slight variation thereof)
2849 		 * remains the dominant model for all SCIFs.
2850 		 */
2851 		regtype = SCIx_SH4_SCIF_REGTYPE;
2852 		break;
2853 	case PORT_HSCIF:
2854 		regtype = SCIx_HSCIF_REGTYPE;
2855 		break;
2856 	default:
2857 		pr_err("Can't probe register map for given port\n");
2858 		return NULL;
2859 	}
2860 
2861 	return &sci_port_params[regtype];
2862 }
2863 
2864 static int sci_init_single(struct platform_device *dev,
2865 			   struct sci_port *sci_port, unsigned int index,
2866 			   const struct plat_sci_port *p, bool early)
2867 {
2868 	struct uart_port *port = &sci_port->port;
2869 	const struct resource *res;
2870 	unsigned int i;
2871 	int ret;
2872 
2873 	sci_port->cfg	= p;
2874 
2875 	port->ops	= &sci_uart_ops;
2876 	port->iotype	= UPIO_MEM;
2877 	port->line	= index;
2878 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2879 
2880 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2881 	if (res == NULL)
2882 		return -ENOMEM;
2883 
2884 	port->mapbase = res->start;
2885 	sci_port->reg_size = resource_size(res);
2886 
2887 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2888 		if (i)
2889 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2890 		else
2891 			sci_port->irqs[i] = platform_get_irq(dev, i);
2892 	}
2893 
2894 	/* The SCI generates several interrupts. They can be muxed together or
2895 	 * connected to different interrupt lines. In the muxed case only one
2896 	 * interrupt resource is specified as there is only one interrupt ID.
2897 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2898 	 * from the SCI, however those signals might have their own individual
2899 	 * interrupt ID numbers, or muxed together with another interrupt.
2900 	 */
2901 	if (sci_port->irqs[0] < 0)
2902 		return -ENXIO;
2903 
2904 	if (sci_port->irqs[1] < 0)
2905 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2906 			sci_port->irqs[i] = sci_port->irqs[0];
2907 
2908 	sci_port->params = sci_probe_regmap(p);
2909 	if (unlikely(sci_port->params == NULL))
2910 		return -EINVAL;
2911 
2912 	switch (p->type) {
2913 	case PORT_SCIFB:
2914 		sci_port->rx_trigger = 48;
2915 		break;
2916 	case PORT_HSCIF:
2917 		sci_port->rx_trigger = 64;
2918 		break;
2919 	case PORT_SCIFA:
2920 		sci_port->rx_trigger = 32;
2921 		break;
2922 	case PORT_SCIF:
2923 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2924 			/* RX triggering not implemented for this IP */
2925 			sci_port->rx_trigger = 1;
2926 		else
2927 			sci_port->rx_trigger = 8;
2928 		break;
2929 	default:
2930 		sci_port->rx_trigger = 1;
2931 		break;
2932 	}
2933 
2934 	sci_port->rx_fifo_timeout = 0;
2935 	sci_port->hscif_tot = 0;
2936 
2937 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2938 	 * match the SoC datasheet, this should be investigated. Let platform
2939 	 * data override the sampling rate for now.
2940 	 */
2941 	sci_port->sampling_rate_mask = p->sampling_rate
2942 				     ? SCI_SR(p->sampling_rate)
2943 				     : sci_port->params->sampling_rate_mask;
2944 
2945 	if (!early) {
2946 		ret = sci_init_clocks(sci_port, &dev->dev);
2947 		if (ret < 0)
2948 			return ret;
2949 
2950 		port->dev = &dev->dev;
2951 
2952 		pm_runtime_enable(&dev->dev);
2953 	}
2954 
2955 	port->type		= p->type;
2956 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2957 	port->fifosize		= sci_port->params->fifosize;
2958 
2959 	if (port->type == PORT_SCI) {
2960 		if (sci_port->reg_size >= 0x20)
2961 			port->regshift = 2;
2962 		else
2963 			port->regshift = 1;
2964 	}
2965 
2966 	/*
2967 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2968 	 * for the multi-IRQ ports, which is where we are primarily
2969 	 * concerned with the shutdown path synchronization.
2970 	 *
2971 	 * For the muxed case there's nothing more to do.
2972 	 */
2973 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2974 	port->irqflags		= 0;
2975 
2976 	port->serial_in		= sci_serial_in;
2977 	port->serial_out	= sci_serial_out;
2978 
2979 	return 0;
2980 }
2981 
2982 static void sci_cleanup_single(struct sci_port *port)
2983 {
2984 	pm_runtime_disable(port->port.dev);
2985 }
2986 
2987 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2988     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2989 static void serial_console_putchar(struct uart_port *port, int ch)
2990 {
2991 	sci_poll_put_char(port, ch);
2992 }
2993 
2994 /*
2995  *	Print a string to the serial port trying not to disturb
2996  *	any possible real use of the port...
2997  */
2998 static void serial_console_write(struct console *co, const char *s,
2999 				 unsigned count)
3000 {
3001 	struct sci_port *sci_port = &sci_ports[co->index];
3002 	struct uart_port *port = &sci_port->port;
3003 	unsigned short bits, ctrl, ctrl_temp;
3004 	unsigned long flags;
3005 	int locked = 1;
3006 
3007 	if (port->sysrq)
3008 		locked = 0;
3009 	else if (oops_in_progress)
3010 		locked = spin_trylock_irqsave(&port->lock, flags);
3011 	else
3012 		spin_lock_irqsave(&port->lock, flags);
3013 
3014 	/* first save SCSCR then disable interrupts, keep clock source */
3015 	ctrl = serial_port_in(port, SCSCR);
3016 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3017 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3018 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3019 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3020 
3021 	uart_console_write(port, s, count, serial_console_putchar);
3022 
3023 	/* wait until fifo is empty and last bit has been transmitted */
3024 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3025 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3026 		cpu_relax();
3027 
3028 	/* restore the SCSCR */
3029 	serial_port_out(port, SCSCR, ctrl);
3030 
3031 	if (locked)
3032 		spin_unlock_irqrestore(&port->lock, flags);
3033 }
3034 
3035 static int serial_console_setup(struct console *co, char *options)
3036 {
3037 	struct sci_port *sci_port;
3038 	struct uart_port *port;
3039 	int baud = 115200;
3040 	int bits = 8;
3041 	int parity = 'n';
3042 	int flow = 'n';
3043 	int ret;
3044 
3045 	/*
3046 	 * Refuse to handle any bogus ports.
3047 	 */
3048 	if (co->index < 0 || co->index >= SCI_NPORTS)
3049 		return -ENODEV;
3050 
3051 	sci_port = &sci_ports[co->index];
3052 	port = &sci_port->port;
3053 
3054 	/*
3055 	 * Refuse to handle uninitialized ports.
3056 	 */
3057 	if (!port->ops)
3058 		return -ENODEV;
3059 
3060 	ret = sci_remap_port(port);
3061 	if (unlikely(ret != 0))
3062 		return ret;
3063 
3064 	if (options)
3065 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3066 
3067 	return uart_set_options(port, co, baud, parity, bits, flow);
3068 }
3069 
3070 static struct console serial_console = {
3071 	.name		= "ttySC",
3072 	.device		= uart_console_device,
3073 	.write		= serial_console_write,
3074 	.setup		= serial_console_setup,
3075 	.flags		= CON_PRINTBUFFER,
3076 	.index		= -1,
3077 	.data		= &sci_uart_driver,
3078 };
3079 
3080 #ifdef CONFIG_SUPERH
3081 static struct console early_serial_console = {
3082 	.name           = "early_ttySC",
3083 	.write          = serial_console_write,
3084 	.flags          = CON_PRINTBUFFER,
3085 	.index		= -1,
3086 };
3087 
3088 static char early_serial_buf[32];
3089 
3090 static int sci_probe_earlyprintk(struct platform_device *pdev)
3091 {
3092 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3093 
3094 	if (early_serial_console.data)
3095 		return -EEXIST;
3096 
3097 	early_serial_console.index = pdev->id;
3098 
3099 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3100 
3101 	serial_console_setup(&early_serial_console, early_serial_buf);
3102 
3103 	if (!strstr(early_serial_buf, "keep"))
3104 		early_serial_console.flags |= CON_BOOT;
3105 
3106 	register_console(&early_serial_console);
3107 	return 0;
3108 }
3109 #endif
3110 
3111 #define SCI_CONSOLE	(&serial_console)
3112 
3113 #else
3114 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3115 {
3116 	return -EINVAL;
3117 }
3118 
3119 #define SCI_CONSOLE	NULL
3120 
3121 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3122 
3123 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3124 
3125 static DEFINE_MUTEX(sci_uart_registration_lock);
3126 static struct uart_driver sci_uart_driver = {
3127 	.owner		= THIS_MODULE,
3128 	.driver_name	= "sci",
3129 	.dev_name	= "ttySC",
3130 	.major		= SCI_MAJOR,
3131 	.minor		= SCI_MINOR_START,
3132 	.nr		= SCI_NPORTS,
3133 	.cons		= SCI_CONSOLE,
3134 };
3135 
3136 static int sci_remove(struct platform_device *dev)
3137 {
3138 	struct sci_port *port = platform_get_drvdata(dev);
3139 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3140 
3141 	sci_ports_in_use &= ~BIT(port->port.line);
3142 	uart_remove_one_port(&sci_uart_driver, &port->port);
3143 
3144 	sci_cleanup_single(port);
3145 
3146 	if (port->port.fifosize > 1)
3147 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3148 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3149 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3150 
3151 	return 0;
3152 }
3153 
3154 
3155 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3156 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3157 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3158 
3159 static const struct of_device_id of_sci_match[] = {
3160 	/* SoC-specific types */
3161 	{
3162 		.compatible = "renesas,scif-r7s72100",
3163 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3164 	},
3165 	{
3166 		.compatible = "renesas,scif-r7s9210",
3167 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3168 	},
3169 	{
3170 		.compatible = "renesas,scif-r9a07g044",
3171 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3172 	},
3173 	/* Family-specific types */
3174 	{
3175 		.compatible = "renesas,rcar-gen1-scif",
3176 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3177 	}, {
3178 		.compatible = "renesas,rcar-gen2-scif",
3179 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3180 	}, {
3181 		.compatible = "renesas,rcar-gen3-scif",
3182 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3183 	},
3184 	/* Generic types */
3185 	{
3186 		.compatible = "renesas,scif",
3187 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3188 	}, {
3189 		.compatible = "renesas,scifa",
3190 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3191 	}, {
3192 		.compatible = "renesas,scifb",
3193 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3194 	}, {
3195 		.compatible = "renesas,hscif",
3196 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3197 	}, {
3198 		.compatible = "renesas,sci",
3199 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3200 	}, {
3201 		/* Terminator */
3202 	},
3203 };
3204 MODULE_DEVICE_TABLE(of, of_sci_match);
3205 
3206 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3207 					  unsigned int *dev_id)
3208 {
3209 	struct device_node *np = pdev->dev.of_node;
3210 	struct plat_sci_port *p;
3211 	struct sci_port *sp;
3212 	const void *data;
3213 	int id;
3214 
3215 	if (!IS_ENABLED(CONFIG_OF) || !np)
3216 		return NULL;
3217 
3218 	data = of_device_get_match_data(&pdev->dev);
3219 
3220 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3221 	if (!p)
3222 		return NULL;
3223 
3224 	/* Get the line number from the aliases node. */
3225 	id = of_alias_get_id(np, "serial");
3226 	if (id < 0 && ~sci_ports_in_use)
3227 		id = ffz(sci_ports_in_use);
3228 	if (id < 0) {
3229 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3230 		return NULL;
3231 	}
3232 	if (id >= ARRAY_SIZE(sci_ports)) {
3233 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3234 		return NULL;
3235 	}
3236 
3237 	sp = &sci_ports[id];
3238 	*dev_id = id;
3239 
3240 	p->type = SCI_OF_TYPE(data);
3241 	p->regtype = SCI_OF_REGTYPE(data);
3242 
3243 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3244 
3245 	return p;
3246 }
3247 
3248 static int sci_probe_single(struct platform_device *dev,
3249 				      unsigned int index,
3250 				      struct plat_sci_port *p,
3251 				      struct sci_port *sciport)
3252 {
3253 	int ret;
3254 
3255 	/* Sanity check */
3256 	if (unlikely(index >= SCI_NPORTS)) {
3257 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3258 			   index+1, SCI_NPORTS);
3259 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3260 		return -EINVAL;
3261 	}
3262 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3263 	if (sci_ports_in_use & BIT(index))
3264 		return -EBUSY;
3265 
3266 	mutex_lock(&sci_uart_registration_lock);
3267 	if (!sci_uart_driver.state) {
3268 		ret = uart_register_driver(&sci_uart_driver);
3269 		if (ret) {
3270 			mutex_unlock(&sci_uart_registration_lock);
3271 			return ret;
3272 		}
3273 	}
3274 	mutex_unlock(&sci_uart_registration_lock);
3275 
3276 	ret = sci_init_single(dev, sciport, index, p, false);
3277 	if (ret)
3278 		return ret;
3279 
3280 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3281 	if (IS_ERR(sciport->gpios))
3282 		return PTR_ERR(sciport->gpios);
3283 
3284 	if (sciport->has_rtscts) {
3285 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3286 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3287 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3288 			return -EINVAL;
3289 		}
3290 		sciport->port.flags |= UPF_HARD_FLOW;
3291 	}
3292 
3293 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3294 	if (ret) {
3295 		sci_cleanup_single(sciport);
3296 		return ret;
3297 	}
3298 
3299 	return 0;
3300 }
3301 
3302 static int sci_probe(struct platform_device *dev)
3303 {
3304 	struct plat_sci_port *p;
3305 	struct sci_port *sp;
3306 	unsigned int dev_id;
3307 	int ret;
3308 
3309 	/*
3310 	 * If we've come here via earlyprintk initialization, head off to
3311 	 * the special early probe. We don't have sufficient device state
3312 	 * to make it beyond this yet.
3313 	 */
3314 #ifdef CONFIG_SUPERH
3315 	if (is_sh_early_platform_device(dev))
3316 		return sci_probe_earlyprintk(dev);
3317 #endif
3318 
3319 	if (dev->dev.of_node) {
3320 		p = sci_parse_dt(dev, &dev_id);
3321 		if (p == NULL)
3322 			return -EINVAL;
3323 	} else {
3324 		p = dev->dev.platform_data;
3325 		if (p == NULL) {
3326 			dev_err(&dev->dev, "no platform data supplied\n");
3327 			return -EINVAL;
3328 		}
3329 
3330 		dev_id = dev->id;
3331 	}
3332 
3333 	sp = &sci_ports[dev_id];
3334 	platform_set_drvdata(dev, sp);
3335 
3336 	ret = sci_probe_single(dev, dev_id, p, sp);
3337 	if (ret)
3338 		return ret;
3339 
3340 	if (sp->port.fifosize > 1) {
3341 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3342 		if (ret)
3343 			return ret;
3344 	}
3345 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3346 	    sp->port.type == PORT_HSCIF) {
3347 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3348 		if (ret) {
3349 			if (sp->port.fifosize > 1) {
3350 				device_remove_file(&dev->dev,
3351 						   &dev_attr_rx_fifo_trigger);
3352 			}
3353 			return ret;
3354 		}
3355 	}
3356 
3357 #ifdef CONFIG_SH_STANDARD_BIOS
3358 	sh_bios_gdb_detach();
3359 #endif
3360 
3361 	sci_ports_in_use |= BIT(dev_id);
3362 	return 0;
3363 }
3364 
3365 static __maybe_unused int sci_suspend(struct device *dev)
3366 {
3367 	struct sci_port *sport = dev_get_drvdata(dev);
3368 
3369 	if (sport)
3370 		uart_suspend_port(&sci_uart_driver, &sport->port);
3371 
3372 	return 0;
3373 }
3374 
3375 static __maybe_unused int sci_resume(struct device *dev)
3376 {
3377 	struct sci_port *sport = dev_get_drvdata(dev);
3378 
3379 	if (sport)
3380 		uart_resume_port(&sci_uart_driver, &sport->port);
3381 
3382 	return 0;
3383 }
3384 
3385 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3386 
3387 static struct platform_driver sci_driver = {
3388 	.probe		= sci_probe,
3389 	.remove		= sci_remove,
3390 	.driver		= {
3391 		.name	= "sh-sci",
3392 		.pm	= &sci_dev_pm_ops,
3393 		.of_match_table = of_match_ptr(of_sci_match),
3394 	},
3395 };
3396 
3397 static int __init sci_init(void)
3398 {
3399 	pr_info("%s\n", banner);
3400 
3401 	return platform_driver_register(&sci_driver);
3402 }
3403 
3404 static void __exit sci_exit(void)
3405 {
3406 	platform_driver_unregister(&sci_driver);
3407 
3408 	if (sci_uart_driver.state)
3409 		uart_unregister_driver(&sci_uart_driver);
3410 }
3411 
3412 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3413 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3414 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3415 #endif
3416 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3417 static struct plat_sci_port port_cfg __initdata;
3418 
3419 static int __init early_console_setup(struct earlycon_device *device,
3420 				      int type)
3421 {
3422 	if (!device->port.membase)
3423 		return -ENODEV;
3424 
3425 	device->port.serial_in = sci_serial_in;
3426 	device->port.serial_out	= sci_serial_out;
3427 	device->port.type = type;
3428 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3429 	port_cfg.type = type;
3430 	sci_ports[0].cfg = &port_cfg;
3431 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3432 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3433 	sci_serial_out(&sci_ports[0].port, SCSCR,
3434 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3435 
3436 	device->con->write = serial_console_write;
3437 	return 0;
3438 }
3439 static int __init sci_early_console_setup(struct earlycon_device *device,
3440 					  const char *opt)
3441 {
3442 	return early_console_setup(device, PORT_SCI);
3443 }
3444 static int __init scif_early_console_setup(struct earlycon_device *device,
3445 					  const char *opt)
3446 {
3447 	return early_console_setup(device, PORT_SCIF);
3448 }
3449 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3450 					  const char *opt)
3451 {
3452 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3453 	return early_console_setup(device, PORT_SCIF);
3454 }
3455 
3456 static int __init scifa_early_console_setup(struct earlycon_device *device,
3457 					  const char *opt)
3458 {
3459 	return early_console_setup(device, PORT_SCIFA);
3460 }
3461 static int __init scifb_early_console_setup(struct earlycon_device *device,
3462 					  const char *opt)
3463 {
3464 	return early_console_setup(device, PORT_SCIFB);
3465 }
3466 static int __init hscif_early_console_setup(struct earlycon_device *device,
3467 					  const char *opt)
3468 {
3469 	return early_console_setup(device, PORT_HSCIF);
3470 }
3471 
3472 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3473 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3474 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3475 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3476 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3477 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3478 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3479 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3480 
3481 module_init(sci_init);
3482 module_exit(sci_exit);
3483 
3484 MODULE_LICENSE("GPL");
3485 MODULE_ALIAS("platform:sh-sci");
3486 MODULE_AUTHOR("Paul Mundt");
3487 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3488