xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision 09c7bda4ddefb1e326378e2aaf1e7814f850d750)
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/reset.h>
41 #include <linux/scatterlist.h>
42 #include <linux/serial.h>
43 #include <linux/serial_sci.h>
44 #include <linux/sh_dma.h>
45 #include <linux/slab.h>
46 #include <linux/string.h>
47 #include <linux/sysrq.h>
48 #include <linux/timer.h>
49 #include <linux/tty.h>
50 #include <linux/tty_flip.h>
51 
52 #ifdef CONFIG_SUPERH
53 #include <asm/sh_bios.h>
54 #include <asm/platform_early.h>
55 #endif
56 
57 #include "serial_mctrl_gpio.h"
58 #include "sh-sci.h"
59 
60 /* Offsets into the sci_port->irqs array */
61 enum {
62 	SCIx_ERI_IRQ,
63 	SCIx_RXI_IRQ,
64 	SCIx_TXI_IRQ,
65 	SCIx_BRI_IRQ,
66 	SCIx_DRI_IRQ,
67 	SCIx_TEI_IRQ,
68 	SCIx_NR_IRQS,
69 
70 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
71 };
72 
73 #define SCIx_IRQ_IS_MUXED(port)			\
74 	((port)->irqs[SCIx_ERI_IRQ] ==	\
75 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
76 	((port)->irqs[SCIx_ERI_IRQ] &&	\
77 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
78 
79 enum SCI_CLKS {
80 	SCI_FCK,		/* Functional Clock */
81 	SCI_SCK,		/* Optional External Clock */
82 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
83 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
84 	SCI_NUM_CLKS
85 };
86 
87 /* Bit x set means sampling rate x + 1 is supported */
88 #define SCI_SR(x)		BIT((x) - 1)
89 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
90 
91 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
92 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
93 				SCI_SR(19) | SCI_SR(27)
94 
95 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
96 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
97 
98 /* Iterate over all supported sampling rates, from high to low */
99 #define for_each_sr(_sr, _port)						\
100 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
101 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
102 
103 struct plat_sci_reg {
104 	u8 offset, size;
105 };
106 
107 struct sci_port_params {
108 	const struct plat_sci_reg regs[SCIx_NR_REGS];
109 	unsigned int fifosize;
110 	unsigned int overrun_reg;
111 	unsigned int overrun_mask;
112 	unsigned int sampling_rate_mask;
113 	unsigned int error_mask;
114 	unsigned int error_clear;
115 };
116 
117 struct sci_port {
118 	struct uart_port	port;
119 
120 	/* Platform configuration */
121 	const struct sci_port_params *params;
122 	const struct plat_sci_port *cfg;
123 	unsigned int		sampling_rate_mask;
124 	resource_size_t		reg_size;
125 	struct mctrl_gpios	*gpios;
126 
127 	/* Clocks */
128 	struct clk		*clks[SCI_NUM_CLKS];
129 	unsigned long		clk_rates[SCI_NUM_CLKS];
130 
131 	int			irqs[SCIx_NR_IRQS];
132 	char			*irqstr[SCIx_NR_IRQS];
133 
134 	struct dma_chan			*chan_tx;
135 	struct dma_chan			*chan_rx;
136 
137 #ifdef CONFIG_SERIAL_SH_SCI_DMA
138 	struct dma_chan			*chan_tx_saved;
139 	struct dma_chan			*chan_rx_saved;
140 	dma_cookie_t			cookie_tx;
141 	dma_cookie_t			cookie_rx[2];
142 	dma_cookie_t			active_rx;
143 	dma_addr_t			tx_dma_addr;
144 	unsigned int			tx_dma_len;
145 	struct scatterlist		sg_rx[2];
146 	void				*rx_buf[2];
147 	size_t				buf_len_rx;
148 	struct work_struct		work_tx;
149 	struct hrtimer			rx_timer;
150 	unsigned int			rx_timeout;	/* microseconds */
151 #endif
152 	unsigned int			rx_frame;
153 	int				rx_trigger;
154 	struct timer_list		rx_fifo_timer;
155 	int				rx_fifo_timeout;
156 	u16				hscif_tot;
157 
158 	bool has_rtscts;
159 	bool autorts;
160 };
161 
162 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
163 
164 static struct sci_port sci_ports[SCI_NPORTS];
165 static unsigned long sci_ports_in_use;
166 static struct uart_driver sci_uart_driver;
167 
168 static inline struct sci_port *
169 to_sci_port(struct uart_port *uart)
170 {
171 	return container_of(uart, struct sci_port, port);
172 }
173 
174 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
175 	/*
176 	 * Common SCI definitions, dependent on the port's regshift
177 	 * value.
178 	 */
179 	[SCIx_SCI_REGTYPE] = {
180 		.regs = {
181 			[SCSMR]		= { 0x00,  8 },
182 			[SCBRR]		= { 0x01,  8 },
183 			[SCSCR]		= { 0x02,  8 },
184 			[SCxTDR]	= { 0x03,  8 },
185 			[SCxSR]		= { 0x04,  8 },
186 			[SCxRDR]	= { 0x05,  8 },
187 		},
188 		.fifosize = 1,
189 		.overrun_reg = SCxSR,
190 		.overrun_mask = SCI_ORER,
191 		.sampling_rate_mask = SCI_SR(32),
192 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
193 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
194 	},
195 
196 	/*
197 	 * Common definitions for legacy IrDA ports.
198 	 */
199 	[SCIx_IRDA_REGTYPE] = {
200 		.regs = {
201 			[SCSMR]		= { 0x00,  8 },
202 			[SCBRR]		= { 0x02,  8 },
203 			[SCSCR]		= { 0x04,  8 },
204 			[SCxTDR]	= { 0x06,  8 },
205 			[SCxSR]		= { 0x08, 16 },
206 			[SCxRDR]	= { 0x0a,  8 },
207 			[SCFCR]		= { 0x0c,  8 },
208 			[SCFDR]		= { 0x0e, 16 },
209 		},
210 		.fifosize = 1,
211 		.overrun_reg = SCxSR,
212 		.overrun_mask = SCI_ORER,
213 		.sampling_rate_mask = SCI_SR(32),
214 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
215 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
216 	},
217 
218 	/*
219 	 * Common SCIFA definitions.
220 	 */
221 	[SCIx_SCIFA_REGTYPE] = {
222 		.regs = {
223 			[SCSMR]		= { 0x00, 16 },
224 			[SCBRR]		= { 0x04,  8 },
225 			[SCSCR]		= { 0x08, 16 },
226 			[SCxTDR]	= { 0x20,  8 },
227 			[SCxSR]		= { 0x14, 16 },
228 			[SCxRDR]	= { 0x24,  8 },
229 			[SCFCR]		= { 0x18, 16 },
230 			[SCFDR]		= { 0x1c, 16 },
231 			[SCPCR]		= { 0x30, 16 },
232 			[SCPDR]		= { 0x34, 16 },
233 		},
234 		.fifosize = 64,
235 		.overrun_reg = SCxSR,
236 		.overrun_mask = SCIFA_ORER,
237 		.sampling_rate_mask = SCI_SR_SCIFAB,
238 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
239 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
240 	},
241 
242 	/*
243 	 * Common SCIFB definitions.
244 	 */
245 	[SCIx_SCIFB_REGTYPE] = {
246 		.regs = {
247 			[SCSMR]		= { 0x00, 16 },
248 			[SCBRR]		= { 0x04,  8 },
249 			[SCSCR]		= { 0x08, 16 },
250 			[SCxTDR]	= { 0x40,  8 },
251 			[SCxSR]		= { 0x14, 16 },
252 			[SCxRDR]	= { 0x60,  8 },
253 			[SCFCR]		= { 0x18, 16 },
254 			[SCTFDR]	= { 0x38, 16 },
255 			[SCRFDR]	= { 0x3c, 16 },
256 			[SCPCR]		= { 0x30, 16 },
257 			[SCPDR]		= { 0x34, 16 },
258 		},
259 		.fifosize = 256,
260 		.overrun_reg = SCxSR,
261 		.overrun_mask = SCIFA_ORER,
262 		.sampling_rate_mask = SCI_SR_SCIFAB,
263 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
264 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
265 	},
266 
267 	/*
268 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
269 	 * count registers.
270 	 */
271 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
272 		.regs = {
273 			[SCSMR]		= { 0x00, 16 },
274 			[SCBRR]		= { 0x04,  8 },
275 			[SCSCR]		= { 0x08, 16 },
276 			[SCxTDR]	= { 0x0c,  8 },
277 			[SCxSR]		= { 0x10, 16 },
278 			[SCxRDR]	= { 0x14,  8 },
279 			[SCFCR]		= { 0x18, 16 },
280 			[SCFDR]		= { 0x1c, 16 },
281 			[SCSPTR]	= { 0x20, 16 },
282 			[SCLSR]		= { 0x24, 16 },
283 		},
284 		.fifosize = 16,
285 		.overrun_reg = SCLSR,
286 		.overrun_mask = SCLSR_ORER,
287 		.sampling_rate_mask = SCI_SR(32),
288 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
289 		.error_clear = SCIF_ERROR_CLEAR,
290 	},
291 
292 	/*
293 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
294 	 * It looks like a normal SCIF with FIFO data, but with a
295 	 * compressed address space. Also, the break out of interrupts
296 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
297 	 */
298 	[SCIx_RZ_SCIFA_REGTYPE] = {
299 		.regs = {
300 			[SCSMR]		= { 0x00, 16 },
301 			[SCBRR]		= { 0x02,  8 },
302 			[SCSCR]		= { 0x04, 16 },
303 			[SCxTDR]	= { 0x06,  8 },
304 			[SCxSR]		= { 0x08, 16 },
305 			[SCxRDR]	= { 0x0A,  8 },
306 			[SCFCR]		= { 0x0C, 16 },
307 			[SCFDR]		= { 0x0E, 16 },
308 			[SCSPTR]	= { 0x10, 16 },
309 			[SCLSR]		= { 0x12, 16 },
310 			[SEMR]		= { 0x14, 8 },
311 		},
312 		.fifosize = 16,
313 		.overrun_reg = SCLSR,
314 		.overrun_mask = SCLSR_ORER,
315 		.sampling_rate_mask = SCI_SR(32),
316 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
317 		.error_clear = SCIF_ERROR_CLEAR,
318 	},
319 
320 	/*
321 	 * Common SH-3 SCIF definitions.
322 	 */
323 	[SCIx_SH3_SCIF_REGTYPE] = {
324 		.regs = {
325 			[SCSMR]		= { 0x00,  8 },
326 			[SCBRR]		= { 0x02,  8 },
327 			[SCSCR]		= { 0x04,  8 },
328 			[SCxTDR]	= { 0x06,  8 },
329 			[SCxSR]		= { 0x08, 16 },
330 			[SCxRDR]	= { 0x0a,  8 },
331 			[SCFCR]		= { 0x0c,  8 },
332 			[SCFDR]		= { 0x0e, 16 },
333 		},
334 		.fifosize = 16,
335 		.overrun_reg = SCLSR,
336 		.overrun_mask = SCLSR_ORER,
337 		.sampling_rate_mask = SCI_SR(32),
338 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
339 		.error_clear = SCIF_ERROR_CLEAR,
340 	},
341 
342 	/*
343 	 * Common SH-4(A) SCIF(B) definitions.
344 	 */
345 	[SCIx_SH4_SCIF_REGTYPE] = {
346 		.regs = {
347 			[SCSMR]		= { 0x00, 16 },
348 			[SCBRR]		= { 0x04,  8 },
349 			[SCSCR]		= { 0x08, 16 },
350 			[SCxTDR]	= { 0x0c,  8 },
351 			[SCxSR]		= { 0x10, 16 },
352 			[SCxRDR]	= { 0x14,  8 },
353 			[SCFCR]		= { 0x18, 16 },
354 			[SCFDR]		= { 0x1c, 16 },
355 			[SCSPTR]	= { 0x20, 16 },
356 			[SCLSR]		= { 0x24, 16 },
357 		},
358 		.fifosize = 16,
359 		.overrun_reg = SCLSR,
360 		.overrun_mask = SCLSR_ORER,
361 		.sampling_rate_mask = SCI_SR(32),
362 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
363 		.error_clear = SCIF_ERROR_CLEAR,
364 	},
365 
366 	/*
367 	 * Common SCIF definitions for ports with a Baud Rate Generator for
368 	 * External Clock (BRG).
369 	 */
370 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
371 		.regs = {
372 			[SCSMR]		= { 0x00, 16 },
373 			[SCBRR]		= { 0x04,  8 },
374 			[SCSCR]		= { 0x08, 16 },
375 			[SCxTDR]	= { 0x0c,  8 },
376 			[SCxSR]		= { 0x10, 16 },
377 			[SCxRDR]	= { 0x14,  8 },
378 			[SCFCR]		= { 0x18, 16 },
379 			[SCFDR]		= { 0x1c, 16 },
380 			[SCSPTR]	= { 0x20, 16 },
381 			[SCLSR]		= { 0x24, 16 },
382 			[SCDL]		= { 0x30, 16 },
383 			[SCCKS]		= { 0x34, 16 },
384 		},
385 		.fifosize = 16,
386 		.overrun_reg = SCLSR,
387 		.overrun_mask = SCLSR_ORER,
388 		.sampling_rate_mask = SCI_SR(32),
389 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
390 		.error_clear = SCIF_ERROR_CLEAR,
391 	},
392 
393 	/*
394 	 * Common HSCIF definitions.
395 	 */
396 	[SCIx_HSCIF_REGTYPE] = {
397 		.regs = {
398 			[SCSMR]		= { 0x00, 16 },
399 			[SCBRR]		= { 0x04,  8 },
400 			[SCSCR]		= { 0x08, 16 },
401 			[SCxTDR]	= { 0x0c,  8 },
402 			[SCxSR]		= { 0x10, 16 },
403 			[SCxRDR]	= { 0x14,  8 },
404 			[SCFCR]		= { 0x18, 16 },
405 			[SCFDR]		= { 0x1c, 16 },
406 			[SCSPTR]	= { 0x20, 16 },
407 			[SCLSR]		= { 0x24, 16 },
408 			[HSSRR]		= { 0x40, 16 },
409 			[SCDL]		= { 0x30, 16 },
410 			[SCCKS]		= { 0x34, 16 },
411 			[HSRTRGR]	= { 0x54, 16 },
412 			[HSTTRGR]	= { 0x58, 16 },
413 		},
414 		.fifosize = 128,
415 		.overrun_reg = SCLSR,
416 		.overrun_mask = SCLSR_ORER,
417 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
418 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
419 		.error_clear = SCIF_ERROR_CLEAR,
420 	},
421 
422 	/*
423 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
424 	 * register.
425 	 */
426 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
427 		.regs = {
428 			[SCSMR]		= { 0x00, 16 },
429 			[SCBRR]		= { 0x04,  8 },
430 			[SCSCR]		= { 0x08, 16 },
431 			[SCxTDR]	= { 0x0c,  8 },
432 			[SCxSR]		= { 0x10, 16 },
433 			[SCxRDR]	= { 0x14,  8 },
434 			[SCFCR]		= { 0x18, 16 },
435 			[SCFDR]		= { 0x1c, 16 },
436 			[SCLSR]		= { 0x24, 16 },
437 		},
438 		.fifosize = 16,
439 		.overrun_reg = SCLSR,
440 		.overrun_mask = SCLSR_ORER,
441 		.sampling_rate_mask = SCI_SR(32),
442 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
443 		.error_clear = SCIF_ERROR_CLEAR,
444 	},
445 
446 	/*
447 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
448 	 * count registers.
449 	 */
450 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
451 		.regs = {
452 			[SCSMR]		= { 0x00, 16 },
453 			[SCBRR]		= { 0x04,  8 },
454 			[SCSCR]		= { 0x08, 16 },
455 			[SCxTDR]	= { 0x0c,  8 },
456 			[SCxSR]		= { 0x10, 16 },
457 			[SCxRDR]	= { 0x14,  8 },
458 			[SCFCR]		= { 0x18, 16 },
459 			[SCFDR]		= { 0x1c, 16 },
460 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
461 			[SCRFDR]	= { 0x20, 16 },
462 			[SCSPTR]	= { 0x24, 16 },
463 			[SCLSR]		= { 0x28, 16 },
464 		},
465 		.fifosize = 16,
466 		.overrun_reg = SCLSR,
467 		.overrun_mask = SCLSR_ORER,
468 		.sampling_rate_mask = SCI_SR(32),
469 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
470 		.error_clear = SCIF_ERROR_CLEAR,
471 	},
472 
473 	/*
474 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
475 	 * registers.
476 	 */
477 	[SCIx_SH7705_SCIF_REGTYPE] = {
478 		.regs = {
479 			[SCSMR]		= { 0x00, 16 },
480 			[SCBRR]		= { 0x04,  8 },
481 			[SCSCR]		= { 0x08, 16 },
482 			[SCxTDR]	= { 0x20,  8 },
483 			[SCxSR]		= { 0x14, 16 },
484 			[SCxRDR]	= { 0x24,  8 },
485 			[SCFCR]		= { 0x18, 16 },
486 			[SCFDR]		= { 0x1c, 16 },
487 		},
488 		.fifosize = 64,
489 		.overrun_reg = SCxSR,
490 		.overrun_mask = SCIFA_ORER,
491 		.sampling_rate_mask = SCI_SR(16),
492 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
493 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
494 	},
495 };
496 
497 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
498 
499 /*
500  * The "offset" here is rather misleading, in that it refers to an enum
501  * value relative to the port mapping rather than the fixed offset
502  * itself, which needs to be manually retrieved from the platform's
503  * register map for the given port.
504  */
505 static unsigned int sci_serial_in(struct uart_port *p, int offset)
506 {
507 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
508 
509 	if (reg->size == 8)
510 		return ioread8(p->membase + (reg->offset << p->regshift));
511 	else if (reg->size == 16)
512 		return ioread16(p->membase + (reg->offset << p->regshift));
513 	else
514 		WARN(1, "Invalid register access\n");
515 
516 	return 0;
517 }
518 
519 static void sci_serial_out(struct uart_port *p, int offset, int value)
520 {
521 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
522 
523 	if (reg->size == 8)
524 		iowrite8(value, p->membase + (reg->offset << p->regshift));
525 	else if (reg->size == 16)
526 		iowrite16(value, p->membase + (reg->offset << p->regshift));
527 	else
528 		WARN(1, "Invalid register access\n");
529 }
530 
531 static void sci_port_enable(struct sci_port *sci_port)
532 {
533 	unsigned int i;
534 
535 	if (!sci_port->port.dev)
536 		return;
537 
538 	pm_runtime_get_sync(sci_port->port.dev);
539 
540 	for (i = 0; i < SCI_NUM_CLKS; i++) {
541 		clk_prepare_enable(sci_port->clks[i]);
542 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
543 	}
544 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
545 }
546 
547 static void sci_port_disable(struct sci_port *sci_port)
548 {
549 	unsigned int i;
550 
551 	if (!sci_port->port.dev)
552 		return;
553 
554 	for (i = SCI_NUM_CLKS; i-- > 0; )
555 		clk_disable_unprepare(sci_port->clks[i]);
556 
557 	pm_runtime_put_sync(sci_port->port.dev);
558 }
559 
560 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
561 {
562 	/*
563 	 * Not all ports (such as SCIFA) will support REIE. Rather than
564 	 * special-casing the port type, we check the port initialization
565 	 * IRQ enable mask to see whether the IRQ is desired at all. If
566 	 * it's unset, it's logically inferred that there's no point in
567 	 * testing for it.
568 	 */
569 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
570 }
571 
572 static void sci_start_tx(struct uart_port *port)
573 {
574 	struct sci_port *s = to_sci_port(port);
575 	unsigned short ctrl;
576 
577 #ifdef CONFIG_SERIAL_SH_SCI_DMA
578 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
579 		u16 new, scr = serial_port_in(port, SCSCR);
580 		if (s->chan_tx)
581 			new = scr | SCSCR_TDRQE;
582 		else
583 			new = scr & ~SCSCR_TDRQE;
584 		if (new != scr)
585 			serial_port_out(port, SCSCR, new);
586 	}
587 
588 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
589 	    dma_submit_error(s->cookie_tx)) {
590 		s->cookie_tx = 0;
591 		schedule_work(&s->work_tx);
592 	}
593 #endif
594 
595 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
596 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
597 		ctrl = serial_port_in(port, SCSCR);
598 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
599 	}
600 }
601 
602 static void sci_stop_tx(struct uart_port *port)
603 {
604 	unsigned short ctrl;
605 
606 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
607 	ctrl = serial_port_in(port, SCSCR);
608 
609 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
610 		ctrl &= ~SCSCR_TDRQE;
611 
612 	ctrl &= ~SCSCR_TIE;
613 
614 	serial_port_out(port, SCSCR, ctrl);
615 
616 #ifdef CONFIG_SERIAL_SH_SCI_DMA
617 	if (to_sci_port(port)->chan_tx &&
618 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
619 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
620 		to_sci_port(port)->cookie_tx = -EINVAL;
621 	}
622 #endif
623 }
624 
625 static void sci_start_rx(struct uart_port *port)
626 {
627 	unsigned short ctrl;
628 
629 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
630 
631 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
632 		ctrl &= ~SCSCR_RDRQE;
633 
634 	serial_port_out(port, SCSCR, ctrl);
635 }
636 
637 static void sci_stop_rx(struct uart_port *port)
638 {
639 	unsigned short ctrl;
640 
641 	ctrl = serial_port_in(port, SCSCR);
642 
643 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
644 		ctrl &= ~SCSCR_RDRQE;
645 
646 	ctrl &= ~port_rx_irq_mask(port);
647 
648 	serial_port_out(port, SCSCR, ctrl);
649 }
650 
651 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
652 {
653 	if (port->type == PORT_SCI) {
654 		/* Just store the mask */
655 		serial_port_out(port, SCxSR, mask);
656 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
657 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
658 		/* Only clear the status bits we want to clear */
659 		serial_port_out(port, SCxSR,
660 				serial_port_in(port, SCxSR) & mask);
661 	} else {
662 		/* Store the mask, clear parity/framing errors */
663 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
664 	}
665 }
666 
667 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
668     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
669 
670 #ifdef CONFIG_CONSOLE_POLL
671 static int sci_poll_get_char(struct uart_port *port)
672 {
673 	unsigned short status;
674 	int c;
675 
676 	do {
677 		status = serial_port_in(port, SCxSR);
678 		if (status & SCxSR_ERRORS(port)) {
679 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
680 			continue;
681 		}
682 		break;
683 	} while (1);
684 
685 	if (!(status & SCxSR_RDxF(port)))
686 		return NO_POLL_CHAR;
687 
688 	c = serial_port_in(port, SCxRDR);
689 
690 	/* Dummy read */
691 	serial_port_in(port, SCxSR);
692 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
693 
694 	return c;
695 }
696 #endif
697 
698 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
699 {
700 	unsigned short status;
701 
702 	do {
703 		status = serial_port_in(port, SCxSR);
704 	} while (!(status & SCxSR_TDxE(port)));
705 
706 	serial_port_out(port, SCxTDR, c);
707 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
708 }
709 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
710 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
711 
712 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
713 {
714 	struct sci_port *s = to_sci_port(port);
715 
716 	/*
717 	 * Use port-specific handler if provided.
718 	 */
719 	if (s->cfg->ops && s->cfg->ops->init_pins) {
720 		s->cfg->ops->init_pins(port, cflag);
721 		return;
722 	}
723 
724 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
725 		u16 data = serial_port_in(port, SCPDR);
726 		u16 ctrl = serial_port_in(port, SCPCR);
727 
728 		/* Enable RXD and TXD pin functions */
729 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
730 		if (to_sci_port(port)->has_rtscts) {
731 			/* RTS# is output, active low, unless autorts */
732 			if (!(port->mctrl & TIOCM_RTS)) {
733 				ctrl |= SCPCR_RTSC;
734 				data |= SCPDR_RTSD;
735 			} else if (!s->autorts) {
736 				ctrl |= SCPCR_RTSC;
737 				data &= ~SCPDR_RTSD;
738 			} else {
739 				/* Enable RTS# pin function */
740 				ctrl &= ~SCPCR_RTSC;
741 			}
742 			/* Enable CTS# pin function */
743 			ctrl &= ~SCPCR_CTSC;
744 		}
745 		serial_port_out(port, SCPDR, data);
746 		serial_port_out(port, SCPCR, ctrl);
747 	} else if (sci_getreg(port, SCSPTR)->size) {
748 		u16 status = serial_port_in(port, SCSPTR);
749 
750 		/* RTS# is always output; and active low, unless autorts */
751 		status |= SCSPTR_RTSIO;
752 		if (!(port->mctrl & TIOCM_RTS))
753 			status |= SCSPTR_RTSDT;
754 		else if (!s->autorts)
755 			status &= ~SCSPTR_RTSDT;
756 		/* CTS# and SCK are inputs */
757 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
758 		serial_port_out(port, SCSPTR, status);
759 	}
760 }
761 
762 static int sci_txfill(struct uart_port *port)
763 {
764 	struct sci_port *s = to_sci_port(port);
765 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
766 	const struct plat_sci_reg *reg;
767 
768 	reg = sci_getreg(port, SCTFDR);
769 	if (reg->size)
770 		return serial_port_in(port, SCTFDR) & fifo_mask;
771 
772 	reg = sci_getreg(port, SCFDR);
773 	if (reg->size)
774 		return serial_port_in(port, SCFDR) >> 8;
775 
776 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
777 }
778 
779 static int sci_txroom(struct uart_port *port)
780 {
781 	return port->fifosize - sci_txfill(port);
782 }
783 
784 static int sci_rxfill(struct uart_port *port)
785 {
786 	struct sci_port *s = to_sci_port(port);
787 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
788 	const struct plat_sci_reg *reg;
789 
790 	reg = sci_getreg(port, SCRFDR);
791 	if (reg->size)
792 		return serial_port_in(port, SCRFDR) & fifo_mask;
793 
794 	reg = sci_getreg(port, SCFDR);
795 	if (reg->size)
796 		return serial_port_in(port, SCFDR) & fifo_mask;
797 
798 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
799 }
800 
801 /* ********************************************************************** *
802  *                   the interrupt related routines                       *
803  * ********************************************************************** */
804 
805 static void sci_transmit_chars(struct uart_port *port)
806 {
807 	struct circ_buf *xmit = &port->state->xmit;
808 	unsigned int stopped = uart_tx_stopped(port);
809 	unsigned short status;
810 	unsigned short ctrl;
811 	int count;
812 
813 	status = serial_port_in(port, SCxSR);
814 	if (!(status & SCxSR_TDxE(port))) {
815 		ctrl = serial_port_in(port, SCSCR);
816 		if (uart_circ_empty(xmit))
817 			ctrl &= ~SCSCR_TIE;
818 		else
819 			ctrl |= SCSCR_TIE;
820 		serial_port_out(port, SCSCR, ctrl);
821 		return;
822 	}
823 
824 	count = sci_txroom(port);
825 
826 	do {
827 		unsigned char c;
828 
829 		if (port->x_char) {
830 			c = port->x_char;
831 			port->x_char = 0;
832 		} else if (!uart_circ_empty(xmit) && !stopped) {
833 			c = xmit->buf[xmit->tail];
834 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
835 		} else {
836 			break;
837 		}
838 
839 		serial_port_out(port, SCxTDR, c);
840 
841 		port->icount.tx++;
842 	} while (--count > 0);
843 
844 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
845 
846 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
847 		uart_write_wakeup(port);
848 	if (uart_circ_empty(xmit))
849 		sci_stop_tx(port);
850 
851 }
852 
853 static void sci_receive_chars(struct uart_port *port)
854 {
855 	struct tty_port *tport = &port->state->port;
856 	int i, count, copied = 0;
857 	unsigned short status;
858 	unsigned char flag;
859 
860 	status = serial_port_in(port, SCxSR);
861 	if (!(status & SCxSR_RDxF(port)))
862 		return;
863 
864 	while (1) {
865 		/* Don't copy more bytes than there is room for in the buffer */
866 		count = tty_buffer_request_room(tport, sci_rxfill(port));
867 
868 		/* If for any reason we can't copy more data, we're done! */
869 		if (count == 0)
870 			break;
871 
872 		if (port->type == PORT_SCI) {
873 			char c = serial_port_in(port, SCxRDR);
874 			if (uart_handle_sysrq_char(port, c))
875 				count = 0;
876 			else
877 				tty_insert_flip_char(tport, c, TTY_NORMAL);
878 		} else {
879 			for (i = 0; i < count; i++) {
880 				char c;
881 
882 				if (port->type == PORT_SCIF ||
883 				    port->type == PORT_HSCIF) {
884 					status = serial_port_in(port, SCxSR);
885 					c = serial_port_in(port, SCxRDR);
886 				} else {
887 					c = serial_port_in(port, SCxRDR);
888 					status = serial_port_in(port, SCxSR);
889 				}
890 				if (uart_handle_sysrq_char(port, c)) {
891 					count--; i--;
892 					continue;
893 				}
894 
895 				/* Store data and status */
896 				if (status & SCxSR_FER(port)) {
897 					flag = TTY_FRAME;
898 					port->icount.frame++;
899 					dev_notice(port->dev, "frame error\n");
900 				} else if (status & SCxSR_PER(port)) {
901 					flag = TTY_PARITY;
902 					port->icount.parity++;
903 					dev_notice(port->dev, "parity error\n");
904 				} else
905 					flag = TTY_NORMAL;
906 
907 				tty_insert_flip_char(tport, c, flag);
908 			}
909 		}
910 
911 		serial_port_in(port, SCxSR); /* dummy read */
912 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
913 
914 		copied += count;
915 		port->icount.rx += count;
916 	}
917 
918 	if (copied) {
919 		/* Tell the rest of the system the news. New characters! */
920 		tty_flip_buffer_push(tport);
921 	} else {
922 		/* TTY buffers full; read from RX reg to prevent lockup */
923 		serial_port_in(port, SCxRDR);
924 		serial_port_in(port, SCxSR); /* dummy read */
925 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
926 	}
927 }
928 
929 static int sci_handle_errors(struct uart_port *port)
930 {
931 	int copied = 0;
932 	unsigned short status = serial_port_in(port, SCxSR);
933 	struct tty_port *tport = &port->state->port;
934 	struct sci_port *s = to_sci_port(port);
935 
936 	/* Handle overruns */
937 	if (status & s->params->overrun_mask) {
938 		port->icount.overrun++;
939 
940 		/* overrun error */
941 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
942 			copied++;
943 
944 		dev_notice(port->dev, "overrun error\n");
945 	}
946 
947 	if (status & SCxSR_FER(port)) {
948 		/* frame error */
949 		port->icount.frame++;
950 
951 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
952 			copied++;
953 
954 		dev_notice(port->dev, "frame error\n");
955 	}
956 
957 	if (status & SCxSR_PER(port)) {
958 		/* parity error */
959 		port->icount.parity++;
960 
961 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
962 			copied++;
963 
964 		dev_notice(port->dev, "parity error\n");
965 	}
966 
967 	if (copied)
968 		tty_flip_buffer_push(tport);
969 
970 	return copied;
971 }
972 
973 static int sci_handle_fifo_overrun(struct uart_port *port)
974 {
975 	struct tty_port *tport = &port->state->port;
976 	struct sci_port *s = to_sci_port(port);
977 	const struct plat_sci_reg *reg;
978 	int copied = 0;
979 	u16 status;
980 
981 	reg = sci_getreg(port, s->params->overrun_reg);
982 	if (!reg->size)
983 		return 0;
984 
985 	status = serial_port_in(port, s->params->overrun_reg);
986 	if (status & s->params->overrun_mask) {
987 		status &= ~s->params->overrun_mask;
988 		serial_port_out(port, s->params->overrun_reg, status);
989 
990 		port->icount.overrun++;
991 
992 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
993 		tty_flip_buffer_push(tport);
994 
995 		dev_dbg(port->dev, "overrun error\n");
996 		copied++;
997 	}
998 
999 	return copied;
1000 }
1001 
1002 static int sci_handle_breaks(struct uart_port *port)
1003 {
1004 	int copied = 0;
1005 	unsigned short status = serial_port_in(port, SCxSR);
1006 	struct tty_port *tport = &port->state->port;
1007 
1008 	if (uart_handle_break(port))
1009 		return 0;
1010 
1011 	if (status & SCxSR_BRK(port)) {
1012 		port->icount.brk++;
1013 
1014 		/* Notify of BREAK */
1015 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1016 			copied++;
1017 
1018 		dev_dbg(port->dev, "BREAK detected\n");
1019 	}
1020 
1021 	if (copied)
1022 		tty_flip_buffer_push(tport);
1023 
1024 	copied += sci_handle_fifo_overrun(port);
1025 
1026 	return copied;
1027 }
1028 
1029 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1030 {
1031 	unsigned int bits;
1032 
1033 	if (rx_trig >= port->fifosize)
1034 		rx_trig = port->fifosize - 1;
1035 	if (rx_trig < 1)
1036 		rx_trig = 1;
1037 
1038 	/* HSCIF can be set to an arbitrary level. */
1039 	if (sci_getreg(port, HSRTRGR)->size) {
1040 		serial_port_out(port, HSRTRGR, rx_trig);
1041 		return rx_trig;
1042 	}
1043 
1044 	switch (port->type) {
1045 	case PORT_SCIF:
1046 		if (rx_trig < 4) {
1047 			bits = 0;
1048 			rx_trig = 1;
1049 		} else if (rx_trig < 8) {
1050 			bits = SCFCR_RTRG0;
1051 			rx_trig = 4;
1052 		} else if (rx_trig < 14) {
1053 			bits = SCFCR_RTRG1;
1054 			rx_trig = 8;
1055 		} else {
1056 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1057 			rx_trig = 14;
1058 		}
1059 		break;
1060 	case PORT_SCIFA:
1061 	case PORT_SCIFB:
1062 		if (rx_trig < 16) {
1063 			bits = 0;
1064 			rx_trig = 1;
1065 		} else if (rx_trig < 32) {
1066 			bits = SCFCR_RTRG0;
1067 			rx_trig = 16;
1068 		} else if (rx_trig < 48) {
1069 			bits = SCFCR_RTRG1;
1070 			rx_trig = 32;
1071 		} else {
1072 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1073 			rx_trig = 48;
1074 		}
1075 		break;
1076 	default:
1077 		WARN(1, "unknown FIFO configuration");
1078 		return 1;
1079 	}
1080 
1081 	serial_port_out(port, SCFCR,
1082 		(serial_port_in(port, SCFCR) &
1083 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1084 
1085 	return rx_trig;
1086 }
1087 
1088 static int scif_rtrg_enabled(struct uart_port *port)
1089 {
1090 	if (sci_getreg(port, HSRTRGR)->size)
1091 		return serial_port_in(port, HSRTRGR) != 0;
1092 	else
1093 		return (serial_port_in(port, SCFCR) &
1094 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1095 }
1096 
1097 static void rx_fifo_timer_fn(struct timer_list *t)
1098 {
1099 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1100 	struct uart_port *port = &s->port;
1101 
1102 	dev_dbg(port->dev, "Rx timed out\n");
1103 	scif_set_rtrg(port, 1);
1104 }
1105 
1106 static ssize_t rx_fifo_trigger_show(struct device *dev,
1107 				    struct device_attribute *attr, char *buf)
1108 {
1109 	struct uart_port *port = dev_get_drvdata(dev);
1110 	struct sci_port *sci = to_sci_port(port);
1111 
1112 	return sprintf(buf, "%d\n", sci->rx_trigger);
1113 }
1114 
1115 static ssize_t rx_fifo_trigger_store(struct device *dev,
1116 				     struct device_attribute *attr,
1117 				     const char *buf, size_t count)
1118 {
1119 	struct uart_port *port = dev_get_drvdata(dev);
1120 	struct sci_port *sci = to_sci_port(port);
1121 	int ret;
1122 	long r;
1123 
1124 	ret = kstrtol(buf, 0, &r);
1125 	if (ret)
1126 		return ret;
1127 
1128 	sci->rx_trigger = scif_set_rtrg(port, r);
1129 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1130 		scif_set_rtrg(port, 1);
1131 
1132 	return count;
1133 }
1134 
1135 static DEVICE_ATTR_RW(rx_fifo_trigger);
1136 
1137 static ssize_t rx_fifo_timeout_show(struct device *dev,
1138 			       struct device_attribute *attr,
1139 			       char *buf)
1140 {
1141 	struct uart_port *port = dev_get_drvdata(dev);
1142 	struct sci_port *sci = to_sci_port(port);
1143 	int v;
1144 
1145 	if (port->type == PORT_HSCIF)
1146 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1147 	else
1148 		v = sci->rx_fifo_timeout;
1149 
1150 	return sprintf(buf, "%d\n", v);
1151 }
1152 
1153 static ssize_t rx_fifo_timeout_store(struct device *dev,
1154 				struct device_attribute *attr,
1155 				const char *buf,
1156 				size_t count)
1157 {
1158 	struct uart_port *port = dev_get_drvdata(dev);
1159 	struct sci_port *sci = to_sci_port(port);
1160 	int ret;
1161 	long r;
1162 
1163 	ret = kstrtol(buf, 0, &r);
1164 	if (ret)
1165 		return ret;
1166 
1167 	if (port->type == PORT_HSCIF) {
1168 		if (r < 0 || r > 3)
1169 			return -EINVAL;
1170 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1171 	} else {
1172 		sci->rx_fifo_timeout = r;
1173 		scif_set_rtrg(port, 1);
1174 		if (r > 0)
1175 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1176 	}
1177 
1178 	return count;
1179 }
1180 
1181 static DEVICE_ATTR_RW(rx_fifo_timeout);
1182 
1183 
1184 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1185 static void sci_dma_tx_complete(void *arg)
1186 {
1187 	struct sci_port *s = arg;
1188 	struct uart_port *port = &s->port;
1189 	struct circ_buf *xmit = &port->state->xmit;
1190 	unsigned long flags;
1191 
1192 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1193 
1194 	spin_lock_irqsave(&port->lock, flags);
1195 
1196 	xmit->tail += s->tx_dma_len;
1197 	xmit->tail &= UART_XMIT_SIZE - 1;
1198 
1199 	port->icount.tx += s->tx_dma_len;
1200 
1201 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1202 		uart_write_wakeup(port);
1203 
1204 	if (!uart_circ_empty(xmit)) {
1205 		s->cookie_tx = 0;
1206 		schedule_work(&s->work_tx);
1207 	} else {
1208 		s->cookie_tx = -EINVAL;
1209 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1210 			u16 ctrl = serial_port_in(port, SCSCR);
1211 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1212 		}
1213 	}
1214 
1215 	spin_unlock_irqrestore(&port->lock, flags);
1216 }
1217 
1218 /* Locking: called with port lock held */
1219 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1220 {
1221 	struct uart_port *port = &s->port;
1222 	struct tty_port *tport = &port->state->port;
1223 	int copied;
1224 
1225 	copied = tty_insert_flip_string(tport, buf, count);
1226 	if (copied < count)
1227 		port->icount.buf_overrun++;
1228 
1229 	port->icount.rx += copied;
1230 
1231 	return copied;
1232 }
1233 
1234 static int sci_dma_rx_find_active(struct sci_port *s)
1235 {
1236 	unsigned int i;
1237 
1238 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1239 		if (s->active_rx == s->cookie_rx[i])
1240 			return i;
1241 
1242 	return -1;
1243 }
1244 
1245 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1246 {
1247 	unsigned int i;
1248 
1249 	s->chan_rx = NULL;
1250 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1251 		s->cookie_rx[i] = -EINVAL;
1252 	s->active_rx = 0;
1253 }
1254 
1255 static void sci_dma_rx_release(struct sci_port *s)
1256 {
1257 	struct dma_chan *chan = s->chan_rx_saved;
1258 
1259 	s->chan_rx_saved = NULL;
1260 	sci_dma_rx_chan_invalidate(s);
1261 	dmaengine_terminate_sync(chan);
1262 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1263 			  sg_dma_address(&s->sg_rx[0]));
1264 	dma_release_channel(chan);
1265 }
1266 
1267 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1268 {
1269 	long sec = usec / 1000000;
1270 	long nsec = (usec % 1000000) * 1000;
1271 	ktime_t t = ktime_set(sec, nsec);
1272 
1273 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1274 }
1275 
1276 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1277 {
1278 	struct uart_port *port = &s->port;
1279 	u16 scr;
1280 
1281 	/* Direct new serial port interrupts back to CPU */
1282 	scr = serial_port_in(port, SCSCR);
1283 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1284 		scr &= ~SCSCR_RDRQE;
1285 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1286 	}
1287 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1288 }
1289 
1290 static void sci_dma_rx_complete(void *arg)
1291 {
1292 	struct sci_port *s = arg;
1293 	struct dma_chan *chan = s->chan_rx;
1294 	struct uart_port *port = &s->port;
1295 	struct dma_async_tx_descriptor *desc;
1296 	unsigned long flags;
1297 	int active, count = 0;
1298 
1299 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1300 		s->active_rx);
1301 
1302 	spin_lock_irqsave(&port->lock, flags);
1303 
1304 	active = sci_dma_rx_find_active(s);
1305 	if (active >= 0)
1306 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1307 
1308 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1309 
1310 	if (count)
1311 		tty_flip_buffer_push(&port->state->port);
1312 
1313 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1314 				       DMA_DEV_TO_MEM,
1315 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1316 	if (!desc)
1317 		goto fail;
1318 
1319 	desc->callback = sci_dma_rx_complete;
1320 	desc->callback_param = s;
1321 	s->cookie_rx[active] = dmaengine_submit(desc);
1322 	if (dma_submit_error(s->cookie_rx[active]))
1323 		goto fail;
1324 
1325 	s->active_rx = s->cookie_rx[!active];
1326 
1327 	dma_async_issue_pending(chan);
1328 
1329 	spin_unlock_irqrestore(&port->lock, flags);
1330 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1331 		__func__, s->cookie_rx[active], active, s->active_rx);
1332 	return;
1333 
1334 fail:
1335 	spin_unlock_irqrestore(&port->lock, flags);
1336 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1337 	/* Switch to PIO */
1338 	spin_lock_irqsave(&port->lock, flags);
1339 	dmaengine_terminate_async(chan);
1340 	sci_dma_rx_chan_invalidate(s);
1341 	sci_dma_rx_reenable_irq(s);
1342 	spin_unlock_irqrestore(&port->lock, flags);
1343 }
1344 
1345 static void sci_dma_tx_release(struct sci_port *s)
1346 {
1347 	struct dma_chan *chan = s->chan_tx_saved;
1348 
1349 	cancel_work_sync(&s->work_tx);
1350 	s->chan_tx_saved = s->chan_tx = NULL;
1351 	s->cookie_tx = -EINVAL;
1352 	dmaengine_terminate_sync(chan);
1353 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1354 			 DMA_TO_DEVICE);
1355 	dma_release_channel(chan);
1356 }
1357 
1358 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1359 {
1360 	struct dma_chan *chan = s->chan_rx;
1361 	struct uart_port *port = &s->port;
1362 	unsigned long flags;
1363 	int i;
1364 
1365 	for (i = 0; i < 2; i++) {
1366 		struct scatterlist *sg = &s->sg_rx[i];
1367 		struct dma_async_tx_descriptor *desc;
1368 
1369 		desc = dmaengine_prep_slave_sg(chan,
1370 			sg, 1, DMA_DEV_TO_MEM,
1371 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1372 		if (!desc)
1373 			goto fail;
1374 
1375 		desc->callback = sci_dma_rx_complete;
1376 		desc->callback_param = s;
1377 		s->cookie_rx[i] = dmaengine_submit(desc);
1378 		if (dma_submit_error(s->cookie_rx[i]))
1379 			goto fail;
1380 
1381 	}
1382 
1383 	s->active_rx = s->cookie_rx[0];
1384 
1385 	dma_async_issue_pending(chan);
1386 	return 0;
1387 
1388 fail:
1389 	/* Switch to PIO */
1390 	if (!port_lock_held)
1391 		spin_lock_irqsave(&port->lock, flags);
1392 	if (i)
1393 		dmaengine_terminate_async(chan);
1394 	sci_dma_rx_chan_invalidate(s);
1395 	sci_start_rx(port);
1396 	if (!port_lock_held)
1397 		spin_unlock_irqrestore(&port->lock, flags);
1398 	return -EAGAIN;
1399 }
1400 
1401 static void sci_dma_tx_work_fn(struct work_struct *work)
1402 {
1403 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1404 	struct dma_async_tx_descriptor *desc;
1405 	struct dma_chan *chan = s->chan_tx;
1406 	struct uart_port *port = &s->port;
1407 	struct circ_buf *xmit = &port->state->xmit;
1408 	unsigned long flags;
1409 	dma_addr_t buf;
1410 	int head, tail;
1411 
1412 	/*
1413 	 * DMA is idle now.
1414 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1415 	 * offsets and lengths. Since it is a circular buffer, we have to
1416 	 * transmit till the end, and then the rest. Take the port lock to get a
1417 	 * consistent xmit buffer state.
1418 	 */
1419 	spin_lock_irq(&port->lock);
1420 	head = xmit->head;
1421 	tail = xmit->tail;
1422 	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1423 	s->tx_dma_len = min_t(unsigned int,
1424 		CIRC_CNT(head, tail, UART_XMIT_SIZE),
1425 		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1426 	if (!s->tx_dma_len) {
1427 		/* Transmit buffer has been flushed */
1428 		spin_unlock_irq(&port->lock);
1429 		return;
1430 	}
1431 
1432 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1433 					   DMA_MEM_TO_DEV,
1434 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1435 	if (!desc) {
1436 		spin_unlock_irq(&port->lock);
1437 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1438 		goto switch_to_pio;
1439 	}
1440 
1441 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1442 				   DMA_TO_DEVICE);
1443 
1444 	desc->callback = sci_dma_tx_complete;
1445 	desc->callback_param = s;
1446 	s->cookie_tx = dmaengine_submit(desc);
1447 	if (dma_submit_error(s->cookie_tx)) {
1448 		spin_unlock_irq(&port->lock);
1449 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1450 		goto switch_to_pio;
1451 	}
1452 
1453 	spin_unlock_irq(&port->lock);
1454 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1455 		__func__, xmit->buf, tail, head, s->cookie_tx);
1456 
1457 	dma_async_issue_pending(chan);
1458 	return;
1459 
1460 switch_to_pio:
1461 	spin_lock_irqsave(&port->lock, flags);
1462 	s->chan_tx = NULL;
1463 	sci_start_tx(port);
1464 	spin_unlock_irqrestore(&port->lock, flags);
1465 	return;
1466 }
1467 
1468 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1469 {
1470 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1471 	struct dma_chan *chan = s->chan_rx;
1472 	struct uart_port *port = &s->port;
1473 	struct dma_tx_state state;
1474 	enum dma_status status;
1475 	unsigned long flags;
1476 	unsigned int read;
1477 	int active, count;
1478 
1479 	dev_dbg(port->dev, "DMA Rx timed out\n");
1480 
1481 	spin_lock_irqsave(&port->lock, flags);
1482 
1483 	active = sci_dma_rx_find_active(s);
1484 	if (active < 0) {
1485 		spin_unlock_irqrestore(&port->lock, flags);
1486 		return HRTIMER_NORESTART;
1487 	}
1488 
1489 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1490 	if (status == DMA_COMPLETE) {
1491 		spin_unlock_irqrestore(&port->lock, flags);
1492 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1493 			s->active_rx, active);
1494 
1495 		/* Let packet complete handler take care of the packet */
1496 		return HRTIMER_NORESTART;
1497 	}
1498 
1499 	dmaengine_pause(chan);
1500 
1501 	/*
1502 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1503 	 * data keeps on coming until transaction is complete so check
1504 	 * for DMA_COMPLETE again
1505 	 * Let packet complete handler take care of the packet
1506 	 */
1507 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1508 	if (status == DMA_COMPLETE) {
1509 		spin_unlock_irqrestore(&port->lock, flags);
1510 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1511 		return HRTIMER_NORESTART;
1512 	}
1513 
1514 	/* Handle incomplete DMA receive */
1515 	dmaengine_terminate_async(s->chan_rx);
1516 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1517 
1518 	if (read) {
1519 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1520 		if (count)
1521 			tty_flip_buffer_push(&port->state->port);
1522 	}
1523 
1524 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1525 		sci_dma_rx_submit(s, true);
1526 
1527 	sci_dma_rx_reenable_irq(s);
1528 
1529 	spin_unlock_irqrestore(&port->lock, flags);
1530 
1531 	return HRTIMER_NORESTART;
1532 }
1533 
1534 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1535 					     enum dma_transfer_direction dir)
1536 {
1537 	struct dma_chan *chan;
1538 	struct dma_slave_config cfg;
1539 	int ret;
1540 
1541 	chan = dma_request_slave_channel(port->dev,
1542 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1543 	if (!chan) {
1544 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1545 		return NULL;
1546 	}
1547 
1548 	memset(&cfg, 0, sizeof(cfg));
1549 	cfg.direction = dir;
1550 	if (dir == DMA_MEM_TO_DEV) {
1551 		cfg.dst_addr = port->mapbase +
1552 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1553 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1554 	} else {
1555 		cfg.src_addr = port->mapbase +
1556 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1557 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1558 	}
1559 
1560 	ret = dmaengine_slave_config(chan, &cfg);
1561 	if (ret) {
1562 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1563 		dma_release_channel(chan);
1564 		return NULL;
1565 	}
1566 
1567 	return chan;
1568 }
1569 
1570 static void sci_request_dma(struct uart_port *port)
1571 {
1572 	struct sci_port *s = to_sci_port(port);
1573 	struct dma_chan *chan;
1574 
1575 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1576 
1577 	/*
1578 	 * DMA on console may interfere with Kernel log messages which use
1579 	 * plain putchar(). So, simply don't use it with a console.
1580 	 */
1581 	if (uart_console(port))
1582 		return;
1583 
1584 	if (!port->dev->of_node)
1585 		return;
1586 
1587 	s->cookie_tx = -EINVAL;
1588 
1589 	/*
1590 	 * Don't request a dma channel if no channel was specified
1591 	 * in the device tree.
1592 	 */
1593 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1594 		return;
1595 
1596 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1597 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1598 	if (chan) {
1599 		/* UART circular tx buffer is an aligned page. */
1600 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1601 						port->state->xmit.buf,
1602 						UART_XMIT_SIZE,
1603 						DMA_TO_DEVICE);
1604 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1605 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1606 			dma_release_channel(chan);
1607 		} else {
1608 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1609 				__func__, UART_XMIT_SIZE,
1610 				port->state->xmit.buf, &s->tx_dma_addr);
1611 
1612 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1613 			s->chan_tx_saved = s->chan_tx = chan;
1614 		}
1615 	}
1616 
1617 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1618 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1619 	if (chan) {
1620 		unsigned int i;
1621 		dma_addr_t dma;
1622 		void *buf;
1623 
1624 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1625 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1626 					 &dma, GFP_KERNEL);
1627 		if (!buf) {
1628 			dev_warn(port->dev,
1629 				 "Failed to allocate Rx dma buffer, using PIO\n");
1630 			dma_release_channel(chan);
1631 			return;
1632 		}
1633 
1634 		for (i = 0; i < 2; i++) {
1635 			struct scatterlist *sg = &s->sg_rx[i];
1636 
1637 			sg_init_table(sg, 1);
1638 			s->rx_buf[i] = buf;
1639 			sg_dma_address(sg) = dma;
1640 			sg_dma_len(sg) = s->buf_len_rx;
1641 
1642 			buf += s->buf_len_rx;
1643 			dma += s->buf_len_rx;
1644 		}
1645 
1646 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1647 		s->rx_timer.function = sci_dma_rx_timer_fn;
1648 
1649 		s->chan_rx_saved = s->chan_rx = chan;
1650 
1651 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1652 			sci_dma_rx_submit(s, false);
1653 	}
1654 }
1655 
1656 static void sci_free_dma(struct uart_port *port)
1657 {
1658 	struct sci_port *s = to_sci_port(port);
1659 
1660 	if (s->chan_tx_saved)
1661 		sci_dma_tx_release(s);
1662 	if (s->chan_rx_saved)
1663 		sci_dma_rx_release(s);
1664 }
1665 
1666 static void sci_flush_buffer(struct uart_port *port)
1667 {
1668 	struct sci_port *s = to_sci_port(port);
1669 
1670 	/*
1671 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1672 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1673 	 * pending transfers
1674 	 */
1675 	s->tx_dma_len = 0;
1676 	if (s->chan_tx) {
1677 		dmaengine_terminate_async(s->chan_tx);
1678 		s->cookie_tx = -EINVAL;
1679 	}
1680 }
1681 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1682 static inline void sci_request_dma(struct uart_port *port)
1683 {
1684 }
1685 
1686 static inline void sci_free_dma(struct uart_port *port)
1687 {
1688 }
1689 
1690 #define sci_flush_buffer	NULL
1691 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1692 
1693 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1694 {
1695 	struct uart_port *port = ptr;
1696 	struct sci_port *s = to_sci_port(port);
1697 
1698 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1699 	if (s->chan_rx) {
1700 		u16 scr = serial_port_in(port, SCSCR);
1701 		u16 ssr = serial_port_in(port, SCxSR);
1702 
1703 		/* Disable future Rx interrupts */
1704 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1705 			disable_irq_nosync(irq);
1706 			scr |= SCSCR_RDRQE;
1707 		} else {
1708 			if (sci_dma_rx_submit(s, false) < 0)
1709 				goto handle_pio;
1710 
1711 			scr &= ~SCSCR_RIE;
1712 		}
1713 		serial_port_out(port, SCSCR, scr);
1714 		/* Clear current interrupt */
1715 		serial_port_out(port, SCxSR,
1716 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1717 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1718 			jiffies, s->rx_timeout);
1719 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1720 
1721 		return IRQ_HANDLED;
1722 	}
1723 
1724 handle_pio:
1725 #endif
1726 
1727 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1728 		if (!scif_rtrg_enabled(port))
1729 			scif_set_rtrg(port, s->rx_trigger);
1730 
1731 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1732 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1733 	}
1734 
1735 	/* I think sci_receive_chars has to be called irrespective
1736 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1737 	 * to be disabled?
1738 	 */
1739 	sci_receive_chars(port);
1740 
1741 	return IRQ_HANDLED;
1742 }
1743 
1744 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1745 {
1746 	struct uart_port *port = ptr;
1747 	unsigned long flags;
1748 
1749 	spin_lock_irqsave(&port->lock, flags);
1750 	sci_transmit_chars(port);
1751 	spin_unlock_irqrestore(&port->lock, flags);
1752 
1753 	return IRQ_HANDLED;
1754 }
1755 
1756 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1757 {
1758 	struct uart_port *port = ptr;
1759 
1760 	/* Handle BREAKs */
1761 	sci_handle_breaks(port);
1762 
1763 	/* drop invalid character received before break was detected */
1764 	serial_port_in(port, SCxRDR);
1765 
1766 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1767 
1768 	return IRQ_HANDLED;
1769 }
1770 
1771 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1772 {
1773 	struct uart_port *port = ptr;
1774 	struct sci_port *s = to_sci_port(port);
1775 
1776 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1777 		/* Break and Error interrupts are muxed */
1778 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1779 
1780 		/* Break Interrupt */
1781 		if (ssr_status & SCxSR_BRK(port))
1782 			sci_br_interrupt(irq, ptr);
1783 
1784 		/* Break only? */
1785 		if (!(ssr_status & SCxSR_ERRORS(port)))
1786 			return IRQ_HANDLED;
1787 	}
1788 
1789 	/* Handle errors */
1790 	if (port->type == PORT_SCI) {
1791 		if (sci_handle_errors(port)) {
1792 			/* discard character in rx buffer */
1793 			serial_port_in(port, SCxSR);
1794 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1795 		}
1796 	} else {
1797 		sci_handle_fifo_overrun(port);
1798 		if (!s->chan_rx)
1799 			sci_receive_chars(port);
1800 	}
1801 
1802 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1803 
1804 	/* Kick the transmission */
1805 	if (!s->chan_tx)
1806 		sci_tx_interrupt(irq, ptr);
1807 
1808 	return IRQ_HANDLED;
1809 }
1810 
1811 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1812 {
1813 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1814 	struct uart_port *port = ptr;
1815 	struct sci_port *s = to_sci_port(port);
1816 	irqreturn_t ret = IRQ_NONE;
1817 
1818 	ssr_status = serial_port_in(port, SCxSR);
1819 	scr_status = serial_port_in(port, SCSCR);
1820 	if (s->params->overrun_reg == SCxSR)
1821 		orer_status = ssr_status;
1822 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1823 		orer_status = serial_port_in(port, s->params->overrun_reg);
1824 
1825 	err_enabled = scr_status & port_rx_irq_mask(port);
1826 
1827 	/* Tx Interrupt */
1828 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1829 	    !s->chan_tx)
1830 		ret = sci_tx_interrupt(irq, ptr);
1831 
1832 	/*
1833 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1834 	 * DR flags
1835 	 */
1836 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1837 	    (scr_status & SCSCR_RIE))
1838 		ret = sci_rx_interrupt(irq, ptr);
1839 
1840 	/* Error Interrupt */
1841 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1842 		ret = sci_er_interrupt(irq, ptr);
1843 
1844 	/* Break Interrupt */
1845 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1846 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1847 		ret = sci_br_interrupt(irq, ptr);
1848 
1849 	/* Overrun Interrupt */
1850 	if (orer_status & s->params->overrun_mask) {
1851 		sci_handle_fifo_overrun(port);
1852 		ret = IRQ_HANDLED;
1853 	}
1854 
1855 	return ret;
1856 }
1857 
1858 static const struct sci_irq_desc {
1859 	const char	*desc;
1860 	irq_handler_t	handler;
1861 } sci_irq_desc[] = {
1862 	/*
1863 	 * Split out handlers, the default case.
1864 	 */
1865 	[SCIx_ERI_IRQ] = {
1866 		.desc = "rx err",
1867 		.handler = sci_er_interrupt,
1868 	},
1869 
1870 	[SCIx_RXI_IRQ] = {
1871 		.desc = "rx full",
1872 		.handler = sci_rx_interrupt,
1873 	},
1874 
1875 	[SCIx_TXI_IRQ] = {
1876 		.desc = "tx empty",
1877 		.handler = sci_tx_interrupt,
1878 	},
1879 
1880 	[SCIx_BRI_IRQ] = {
1881 		.desc = "break",
1882 		.handler = sci_br_interrupt,
1883 	},
1884 
1885 	[SCIx_DRI_IRQ] = {
1886 		.desc = "rx ready",
1887 		.handler = sci_rx_interrupt,
1888 	},
1889 
1890 	[SCIx_TEI_IRQ] = {
1891 		.desc = "tx end",
1892 		.handler = sci_tx_interrupt,
1893 	},
1894 
1895 	/*
1896 	 * Special muxed handler.
1897 	 */
1898 	[SCIx_MUX_IRQ] = {
1899 		.desc = "mux",
1900 		.handler = sci_mpxed_interrupt,
1901 	},
1902 };
1903 
1904 static int sci_request_irq(struct sci_port *port)
1905 {
1906 	struct uart_port *up = &port->port;
1907 	int i, j, w, ret = 0;
1908 
1909 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1910 		const struct sci_irq_desc *desc;
1911 		int irq;
1912 
1913 		/* Check if already registered (muxed) */
1914 		for (w = 0; w < i; w++)
1915 			if (port->irqs[w] == port->irqs[i])
1916 				w = i + 1;
1917 		if (w > i)
1918 			continue;
1919 
1920 		if (SCIx_IRQ_IS_MUXED(port)) {
1921 			i = SCIx_MUX_IRQ;
1922 			irq = up->irq;
1923 		} else {
1924 			irq = port->irqs[i];
1925 
1926 			/*
1927 			 * Certain port types won't support all of the
1928 			 * available interrupt sources.
1929 			 */
1930 			if (unlikely(irq < 0))
1931 				continue;
1932 		}
1933 
1934 		desc = sci_irq_desc + i;
1935 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1936 					    dev_name(up->dev), desc->desc);
1937 		if (!port->irqstr[j]) {
1938 			ret = -ENOMEM;
1939 			goto out_nomem;
1940 		}
1941 
1942 		ret = request_irq(irq, desc->handler, up->irqflags,
1943 				  port->irqstr[j], port);
1944 		if (unlikely(ret)) {
1945 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1946 			goto out_noirq;
1947 		}
1948 	}
1949 
1950 	return 0;
1951 
1952 out_noirq:
1953 	while (--i >= 0)
1954 		free_irq(port->irqs[i], port);
1955 
1956 out_nomem:
1957 	while (--j >= 0)
1958 		kfree(port->irqstr[j]);
1959 
1960 	return ret;
1961 }
1962 
1963 static void sci_free_irq(struct sci_port *port)
1964 {
1965 	int i, j;
1966 
1967 	/*
1968 	 * Intentionally in reverse order so we iterate over the muxed
1969 	 * IRQ first.
1970 	 */
1971 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1972 		int irq = port->irqs[i];
1973 
1974 		/*
1975 		 * Certain port types won't support all of the available
1976 		 * interrupt sources.
1977 		 */
1978 		if (unlikely(irq < 0))
1979 			continue;
1980 
1981 		/* Check if already freed (irq was muxed) */
1982 		for (j = 0; j < i; j++)
1983 			if (port->irqs[j] == irq)
1984 				j = i + 1;
1985 		if (j > i)
1986 			continue;
1987 
1988 		free_irq(port->irqs[i], port);
1989 		kfree(port->irqstr[i]);
1990 
1991 		if (SCIx_IRQ_IS_MUXED(port)) {
1992 			/* If there's only one IRQ, we're done. */
1993 			return;
1994 		}
1995 	}
1996 }
1997 
1998 static unsigned int sci_tx_empty(struct uart_port *port)
1999 {
2000 	unsigned short status = serial_port_in(port, SCxSR);
2001 	unsigned short in_tx_fifo = sci_txfill(port);
2002 
2003 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2004 }
2005 
2006 static void sci_set_rts(struct uart_port *port, bool state)
2007 {
2008 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2009 		u16 data = serial_port_in(port, SCPDR);
2010 
2011 		/* Active low */
2012 		if (state)
2013 			data &= ~SCPDR_RTSD;
2014 		else
2015 			data |= SCPDR_RTSD;
2016 		serial_port_out(port, SCPDR, data);
2017 
2018 		/* RTS# is output */
2019 		serial_port_out(port, SCPCR,
2020 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2021 	} else if (sci_getreg(port, SCSPTR)->size) {
2022 		u16 ctrl = serial_port_in(port, SCSPTR);
2023 
2024 		/* Active low */
2025 		if (state)
2026 			ctrl &= ~SCSPTR_RTSDT;
2027 		else
2028 			ctrl |= SCSPTR_RTSDT;
2029 		serial_port_out(port, SCSPTR, ctrl);
2030 	}
2031 }
2032 
2033 static bool sci_get_cts(struct uart_port *port)
2034 {
2035 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2036 		/* Active low */
2037 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2038 	} else if (sci_getreg(port, SCSPTR)->size) {
2039 		/* Active low */
2040 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2041 	}
2042 
2043 	return true;
2044 }
2045 
2046 /*
2047  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2048  * CTS/RTS is supported in hardware by at least one port and controlled
2049  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2050  * handled via the ->init_pins() op, which is a bit of a one-way street,
2051  * lacking any ability to defer pin control -- this will later be
2052  * converted over to the GPIO framework).
2053  *
2054  * Other modes (such as loopback) are supported generically on certain
2055  * port types, but not others. For these it's sufficient to test for the
2056  * existence of the support register and simply ignore the port type.
2057  */
2058 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2059 {
2060 	struct sci_port *s = to_sci_port(port);
2061 
2062 	if (mctrl & TIOCM_LOOP) {
2063 		const struct plat_sci_reg *reg;
2064 
2065 		/*
2066 		 * Standard loopback mode for SCFCR ports.
2067 		 */
2068 		reg = sci_getreg(port, SCFCR);
2069 		if (reg->size)
2070 			serial_port_out(port, SCFCR,
2071 					serial_port_in(port, SCFCR) |
2072 					SCFCR_LOOP);
2073 	}
2074 
2075 	mctrl_gpio_set(s->gpios, mctrl);
2076 
2077 	if (!s->has_rtscts)
2078 		return;
2079 
2080 	if (!(mctrl & TIOCM_RTS)) {
2081 		/* Disable Auto RTS */
2082 		serial_port_out(port, SCFCR,
2083 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2084 
2085 		/* Clear RTS */
2086 		sci_set_rts(port, 0);
2087 	} else if (s->autorts) {
2088 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2089 			/* Enable RTS# pin function */
2090 			serial_port_out(port, SCPCR,
2091 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2092 		}
2093 
2094 		/* Enable Auto RTS */
2095 		serial_port_out(port, SCFCR,
2096 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2097 	} else {
2098 		/* Set RTS */
2099 		sci_set_rts(port, 1);
2100 	}
2101 }
2102 
2103 static unsigned int sci_get_mctrl(struct uart_port *port)
2104 {
2105 	struct sci_port *s = to_sci_port(port);
2106 	struct mctrl_gpios *gpios = s->gpios;
2107 	unsigned int mctrl = 0;
2108 
2109 	mctrl_gpio_get(gpios, &mctrl);
2110 
2111 	/*
2112 	 * CTS/RTS is handled in hardware when supported, while nothing
2113 	 * else is wired up.
2114 	 */
2115 	if (s->autorts) {
2116 		if (sci_get_cts(port))
2117 			mctrl |= TIOCM_CTS;
2118 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2119 		mctrl |= TIOCM_CTS;
2120 	}
2121 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2122 		mctrl |= TIOCM_DSR;
2123 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2124 		mctrl |= TIOCM_CAR;
2125 
2126 	return mctrl;
2127 }
2128 
2129 static void sci_enable_ms(struct uart_port *port)
2130 {
2131 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2132 }
2133 
2134 static void sci_break_ctl(struct uart_port *port, int break_state)
2135 {
2136 	unsigned short scscr, scsptr;
2137 	unsigned long flags;
2138 
2139 	/* check whether the port has SCSPTR */
2140 	if (!sci_getreg(port, SCSPTR)->size) {
2141 		/*
2142 		 * Not supported by hardware. Most parts couple break and rx
2143 		 * interrupts together, with break detection always enabled.
2144 		 */
2145 		return;
2146 	}
2147 
2148 	spin_lock_irqsave(&port->lock, flags);
2149 	scsptr = serial_port_in(port, SCSPTR);
2150 	scscr = serial_port_in(port, SCSCR);
2151 
2152 	if (break_state == -1) {
2153 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2154 		scscr &= ~SCSCR_TE;
2155 	} else {
2156 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2157 		scscr |= SCSCR_TE;
2158 	}
2159 
2160 	serial_port_out(port, SCSPTR, scsptr);
2161 	serial_port_out(port, SCSCR, scscr);
2162 	spin_unlock_irqrestore(&port->lock, flags);
2163 }
2164 
2165 static int sci_startup(struct uart_port *port)
2166 {
2167 	struct sci_port *s = to_sci_port(port);
2168 	int ret;
2169 
2170 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2171 
2172 	sci_request_dma(port);
2173 
2174 	ret = sci_request_irq(s);
2175 	if (unlikely(ret < 0)) {
2176 		sci_free_dma(port);
2177 		return ret;
2178 	}
2179 
2180 	return 0;
2181 }
2182 
2183 static void sci_shutdown(struct uart_port *port)
2184 {
2185 	struct sci_port *s = to_sci_port(port);
2186 	unsigned long flags;
2187 	u16 scr;
2188 
2189 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2190 
2191 	s->autorts = false;
2192 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2193 
2194 	spin_lock_irqsave(&port->lock, flags);
2195 	sci_stop_rx(port);
2196 	sci_stop_tx(port);
2197 	/*
2198 	 * Stop RX and TX, disable related interrupts, keep clock source
2199 	 * and HSCIF TOT bits
2200 	 */
2201 	scr = serial_port_in(port, SCSCR);
2202 	serial_port_out(port, SCSCR, scr &
2203 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2204 	spin_unlock_irqrestore(&port->lock, flags);
2205 
2206 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2207 	if (s->chan_rx_saved) {
2208 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2209 			port->line);
2210 		hrtimer_cancel(&s->rx_timer);
2211 	}
2212 #endif
2213 
2214 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2215 		del_timer_sync(&s->rx_fifo_timer);
2216 	sci_free_irq(s);
2217 	sci_free_dma(port);
2218 }
2219 
2220 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2221 			unsigned int *srr)
2222 {
2223 	unsigned long freq = s->clk_rates[SCI_SCK];
2224 	int err, min_err = INT_MAX;
2225 	unsigned int sr;
2226 
2227 	if (s->port.type != PORT_HSCIF)
2228 		freq *= 2;
2229 
2230 	for_each_sr(sr, s) {
2231 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2232 		if (abs(err) >= abs(min_err))
2233 			continue;
2234 
2235 		min_err = err;
2236 		*srr = sr - 1;
2237 
2238 		if (!err)
2239 			break;
2240 	}
2241 
2242 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2243 		*srr + 1);
2244 	return min_err;
2245 }
2246 
2247 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2248 			unsigned long freq, unsigned int *dlr,
2249 			unsigned int *srr)
2250 {
2251 	int err, min_err = INT_MAX;
2252 	unsigned int sr, dl;
2253 
2254 	if (s->port.type != PORT_HSCIF)
2255 		freq *= 2;
2256 
2257 	for_each_sr(sr, s) {
2258 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2259 		dl = clamp(dl, 1U, 65535U);
2260 
2261 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2262 		if (abs(err) >= abs(min_err))
2263 			continue;
2264 
2265 		min_err = err;
2266 		*dlr = dl;
2267 		*srr = sr - 1;
2268 
2269 		if (!err)
2270 			break;
2271 	}
2272 
2273 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2274 		min_err, *dlr, *srr + 1);
2275 	return min_err;
2276 }
2277 
2278 /* calculate sample rate, BRR, and clock select */
2279 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2280 			  unsigned int *brr, unsigned int *srr,
2281 			  unsigned int *cks)
2282 {
2283 	unsigned long freq = s->clk_rates[SCI_FCK];
2284 	unsigned int sr, br, prediv, scrate, c;
2285 	int err, min_err = INT_MAX;
2286 
2287 	if (s->port.type != PORT_HSCIF)
2288 		freq *= 2;
2289 
2290 	/*
2291 	 * Find the combination of sample rate and clock select with the
2292 	 * smallest deviation from the desired baud rate.
2293 	 * Prefer high sample rates to maximise the receive margin.
2294 	 *
2295 	 * M: Receive margin (%)
2296 	 * N: Ratio of bit rate to clock (N = sampling rate)
2297 	 * D: Clock duty (D = 0 to 1.0)
2298 	 * L: Frame length (L = 9 to 12)
2299 	 * F: Absolute value of clock frequency deviation
2300 	 *
2301 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2302 	 *      (|D - 0.5| / N * (1 + F))|
2303 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2304 	 */
2305 	for_each_sr(sr, s) {
2306 		for (c = 0; c <= 3; c++) {
2307 			/* integerized formulas from HSCIF documentation */
2308 			prediv = sr * (1 << (2 * c + 1));
2309 
2310 			/*
2311 			 * We need to calculate:
2312 			 *
2313 			 *     br = freq / (prediv * bps) clamped to [1..256]
2314 			 *     err = freq / (br * prediv) - bps
2315 			 *
2316 			 * Watch out for overflow when calculating the desired
2317 			 * sampling clock rate!
2318 			 */
2319 			if (bps > UINT_MAX / prediv)
2320 				break;
2321 
2322 			scrate = prediv * bps;
2323 			br = DIV_ROUND_CLOSEST(freq, scrate);
2324 			br = clamp(br, 1U, 256U);
2325 
2326 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2327 			if (abs(err) >= abs(min_err))
2328 				continue;
2329 
2330 			min_err = err;
2331 			*brr = br - 1;
2332 			*srr = sr - 1;
2333 			*cks = c;
2334 
2335 			if (!err)
2336 				goto found;
2337 		}
2338 	}
2339 
2340 found:
2341 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2342 		min_err, *brr, *srr + 1, *cks);
2343 	return min_err;
2344 }
2345 
2346 static void sci_reset(struct uart_port *port)
2347 {
2348 	const struct plat_sci_reg *reg;
2349 	unsigned int status;
2350 	struct sci_port *s = to_sci_port(port);
2351 
2352 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2353 
2354 	reg = sci_getreg(port, SCFCR);
2355 	if (reg->size)
2356 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2357 
2358 	sci_clear_SCxSR(port,
2359 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2360 			SCxSR_BREAK_CLEAR(port));
2361 	if (sci_getreg(port, SCLSR)->size) {
2362 		status = serial_port_in(port, SCLSR);
2363 		status &= ~(SCLSR_TO | SCLSR_ORER);
2364 		serial_port_out(port, SCLSR, status);
2365 	}
2366 
2367 	if (s->rx_trigger > 1) {
2368 		if (s->rx_fifo_timeout) {
2369 			scif_set_rtrg(port, 1);
2370 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2371 		} else {
2372 			if (port->type == PORT_SCIFA ||
2373 			    port->type == PORT_SCIFB)
2374 				scif_set_rtrg(port, 1);
2375 			else
2376 				scif_set_rtrg(port, s->rx_trigger);
2377 		}
2378 	}
2379 }
2380 
2381 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2382 			    struct ktermios *old)
2383 {
2384 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2385 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2386 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2387 	struct sci_port *s = to_sci_port(port);
2388 	const struct plat_sci_reg *reg;
2389 	int min_err = INT_MAX, err;
2390 	unsigned long max_freq = 0;
2391 	int best_clk = -1;
2392 	unsigned long flags;
2393 
2394 	if ((termios->c_cflag & CSIZE) == CS7)
2395 		smr_val |= SCSMR_CHR;
2396 	if (termios->c_cflag & PARENB)
2397 		smr_val |= SCSMR_PE;
2398 	if (termios->c_cflag & PARODD)
2399 		smr_val |= SCSMR_PE | SCSMR_ODD;
2400 	if (termios->c_cflag & CSTOPB)
2401 		smr_val |= SCSMR_STOP;
2402 
2403 	/*
2404 	 * earlyprintk comes here early on with port->uartclk set to zero.
2405 	 * the clock framework is not up and running at this point so here
2406 	 * we assume that 115200 is the maximum baud rate. please note that
2407 	 * the baud rate is not programmed during earlyprintk - it is assumed
2408 	 * that the previous boot loader has enabled required clocks and
2409 	 * setup the baud rate generator hardware for us already.
2410 	 */
2411 	if (!port->uartclk) {
2412 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2413 		goto done;
2414 	}
2415 
2416 	for (i = 0; i < SCI_NUM_CLKS; i++)
2417 		max_freq = max(max_freq, s->clk_rates[i]);
2418 
2419 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2420 	if (!baud)
2421 		goto done;
2422 
2423 	/*
2424 	 * There can be multiple sources for the sampling clock.  Find the one
2425 	 * that gives us the smallest deviation from the desired baud rate.
2426 	 */
2427 
2428 	/* Optional Undivided External Clock */
2429 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2430 	    port->type != PORT_SCIFB) {
2431 		err = sci_sck_calc(s, baud, &srr1);
2432 		if (abs(err) < abs(min_err)) {
2433 			best_clk = SCI_SCK;
2434 			scr_val = SCSCR_CKE1;
2435 			sccks = SCCKS_CKS;
2436 			min_err = err;
2437 			srr = srr1;
2438 			if (!err)
2439 				goto done;
2440 		}
2441 	}
2442 
2443 	/* Optional BRG Frequency Divided External Clock */
2444 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2445 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2446 				   &srr1);
2447 		if (abs(err) < abs(min_err)) {
2448 			best_clk = SCI_SCIF_CLK;
2449 			scr_val = SCSCR_CKE1;
2450 			sccks = 0;
2451 			min_err = err;
2452 			dl = dl1;
2453 			srr = srr1;
2454 			if (!err)
2455 				goto done;
2456 		}
2457 	}
2458 
2459 	/* Optional BRG Frequency Divided Internal Clock */
2460 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2461 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2462 				   &srr1);
2463 		if (abs(err) < abs(min_err)) {
2464 			best_clk = SCI_BRG_INT;
2465 			scr_val = SCSCR_CKE1;
2466 			sccks = SCCKS_XIN;
2467 			min_err = err;
2468 			dl = dl1;
2469 			srr = srr1;
2470 			if (!min_err)
2471 				goto done;
2472 		}
2473 	}
2474 
2475 	/* Divided Functional Clock using standard Bit Rate Register */
2476 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2477 	if (abs(err) < abs(min_err)) {
2478 		best_clk = SCI_FCK;
2479 		scr_val = 0;
2480 		min_err = err;
2481 		brr = brr1;
2482 		srr = srr1;
2483 		cks = cks1;
2484 	}
2485 
2486 done:
2487 	if (best_clk >= 0)
2488 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2489 			s->clks[best_clk], baud, min_err);
2490 
2491 	sci_port_enable(s);
2492 
2493 	/*
2494 	 * Program the optional External Baud Rate Generator (BRG) first.
2495 	 * It controls the mux to select (H)SCK or frequency divided clock.
2496 	 */
2497 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2498 		serial_port_out(port, SCDL, dl);
2499 		serial_port_out(port, SCCKS, sccks);
2500 	}
2501 
2502 	spin_lock_irqsave(&port->lock, flags);
2503 
2504 	sci_reset(port);
2505 
2506 	uart_update_timeout(port, termios->c_cflag, baud);
2507 
2508 	/* byte size and parity */
2509 	bits = tty_get_frame_size(termios->c_cflag);
2510 
2511 	if (sci_getreg(port, SEMR)->size)
2512 		serial_port_out(port, SEMR, 0);
2513 
2514 	if (best_clk >= 0) {
2515 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2516 			switch (srr + 1) {
2517 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2518 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2519 			case 11: smr_val |= SCSMR_SRC_11; break;
2520 			case 13: smr_val |= SCSMR_SRC_13; break;
2521 			case 16: smr_val |= SCSMR_SRC_16; break;
2522 			case 17: smr_val |= SCSMR_SRC_17; break;
2523 			case 19: smr_val |= SCSMR_SRC_19; break;
2524 			case 27: smr_val |= SCSMR_SRC_27; break;
2525 			}
2526 		smr_val |= cks;
2527 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2528 		serial_port_out(port, SCSMR, smr_val);
2529 		serial_port_out(port, SCBRR, brr);
2530 		if (sci_getreg(port, HSSRR)->size) {
2531 			unsigned int hssrr = srr | HSCIF_SRE;
2532 			/* Calculate deviation from intended rate at the
2533 			 * center of the last stop bit in sampling clocks.
2534 			 */
2535 			int last_stop = bits * 2 - 1;
2536 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2537 							  (int)(srr + 1),
2538 							  2 * (int)baud);
2539 
2540 			if (abs(deviation) >= 2) {
2541 				/* At least two sampling clocks off at the
2542 				 * last stop bit; we can increase the error
2543 				 * margin by shifting the sampling point.
2544 				 */
2545 				int shift = clamp(deviation / 2, -8, 7);
2546 
2547 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2548 					 HSCIF_SRHP_MASK;
2549 				hssrr |= HSCIF_SRDE;
2550 			}
2551 			serial_port_out(port, HSSRR, hssrr);
2552 		}
2553 
2554 		/* Wait one bit interval */
2555 		udelay((1000000 + (baud - 1)) / baud);
2556 	} else {
2557 		/* Don't touch the bit rate configuration */
2558 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2559 		smr_val |= serial_port_in(port, SCSMR) &
2560 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2561 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2562 		serial_port_out(port, SCSMR, smr_val);
2563 	}
2564 
2565 	sci_init_pins(port, termios->c_cflag);
2566 
2567 	port->status &= ~UPSTAT_AUTOCTS;
2568 	s->autorts = false;
2569 	reg = sci_getreg(port, SCFCR);
2570 	if (reg->size) {
2571 		unsigned short ctrl = serial_port_in(port, SCFCR);
2572 
2573 		if ((port->flags & UPF_HARD_FLOW) &&
2574 		    (termios->c_cflag & CRTSCTS)) {
2575 			/* There is no CTS interrupt to restart the hardware */
2576 			port->status |= UPSTAT_AUTOCTS;
2577 			/* MCE is enabled when RTS is raised */
2578 			s->autorts = true;
2579 		}
2580 
2581 		/*
2582 		 * As we've done a sci_reset() above, ensure we don't
2583 		 * interfere with the FIFOs while toggling MCE. As the
2584 		 * reset values could still be set, simply mask them out.
2585 		 */
2586 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2587 
2588 		serial_port_out(port, SCFCR, ctrl);
2589 	}
2590 	if (port->flags & UPF_HARD_FLOW) {
2591 		/* Refresh (Auto) RTS */
2592 		sci_set_mctrl(port, port->mctrl);
2593 	}
2594 
2595 	scr_val |= SCSCR_RE | SCSCR_TE |
2596 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2597 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2598 	if ((srr + 1 == 5) &&
2599 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2600 		/*
2601 		 * In asynchronous mode, when the sampling rate is 1/5, first
2602 		 * received data may become invalid on some SCIFA and SCIFB.
2603 		 * To avoid this problem wait more than 1 serial data time (1
2604 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2605 		 */
2606 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2607 	}
2608 
2609 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2610 	s->rx_frame = (10000 * bits) / (baud / 100);
2611 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2612 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2613 #endif
2614 
2615 	if ((termios->c_cflag & CREAD) != 0)
2616 		sci_start_rx(port);
2617 
2618 	spin_unlock_irqrestore(&port->lock, flags);
2619 
2620 	sci_port_disable(s);
2621 
2622 	if (UART_ENABLE_MS(port, termios->c_cflag))
2623 		sci_enable_ms(port);
2624 }
2625 
2626 static void sci_pm(struct uart_port *port, unsigned int state,
2627 		   unsigned int oldstate)
2628 {
2629 	struct sci_port *sci_port = to_sci_port(port);
2630 
2631 	switch (state) {
2632 	case UART_PM_STATE_OFF:
2633 		sci_port_disable(sci_port);
2634 		break;
2635 	default:
2636 		sci_port_enable(sci_port);
2637 		break;
2638 	}
2639 }
2640 
2641 static const char *sci_type(struct uart_port *port)
2642 {
2643 	switch (port->type) {
2644 	case PORT_IRDA:
2645 		return "irda";
2646 	case PORT_SCI:
2647 		return "sci";
2648 	case PORT_SCIF:
2649 		return "scif";
2650 	case PORT_SCIFA:
2651 		return "scifa";
2652 	case PORT_SCIFB:
2653 		return "scifb";
2654 	case PORT_HSCIF:
2655 		return "hscif";
2656 	}
2657 
2658 	return NULL;
2659 }
2660 
2661 static int sci_remap_port(struct uart_port *port)
2662 {
2663 	struct sci_port *sport = to_sci_port(port);
2664 
2665 	/*
2666 	 * Nothing to do if there's already an established membase.
2667 	 */
2668 	if (port->membase)
2669 		return 0;
2670 
2671 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2672 		port->membase = ioremap(port->mapbase, sport->reg_size);
2673 		if (unlikely(!port->membase)) {
2674 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2675 			return -ENXIO;
2676 		}
2677 	} else {
2678 		/*
2679 		 * For the simple (and majority of) cases where we don't
2680 		 * need to do any remapping, just cast the cookie
2681 		 * directly.
2682 		 */
2683 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2684 	}
2685 
2686 	return 0;
2687 }
2688 
2689 static void sci_release_port(struct uart_port *port)
2690 {
2691 	struct sci_port *sport = to_sci_port(port);
2692 
2693 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2694 		iounmap(port->membase);
2695 		port->membase = NULL;
2696 	}
2697 
2698 	release_mem_region(port->mapbase, sport->reg_size);
2699 }
2700 
2701 static int sci_request_port(struct uart_port *port)
2702 {
2703 	struct resource *res;
2704 	struct sci_port *sport = to_sci_port(port);
2705 	int ret;
2706 
2707 	res = request_mem_region(port->mapbase, sport->reg_size,
2708 				 dev_name(port->dev));
2709 	if (unlikely(res == NULL)) {
2710 		dev_err(port->dev, "request_mem_region failed.");
2711 		return -EBUSY;
2712 	}
2713 
2714 	ret = sci_remap_port(port);
2715 	if (unlikely(ret != 0)) {
2716 		release_resource(res);
2717 		return ret;
2718 	}
2719 
2720 	return 0;
2721 }
2722 
2723 static void sci_config_port(struct uart_port *port, int flags)
2724 {
2725 	if (flags & UART_CONFIG_TYPE) {
2726 		struct sci_port *sport = to_sci_port(port);
2727 
2728 		port->type = sport->cfg->type;
2729 		sci_request_port(port);
2730 	}
2731 }
2732 
2733 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2734 {
2735 	if (ser->baud_base < 2400)
2736 		/* No paper tape reader for Mitch.. */
2737 		return -EINVAL;
2738 
2739 	return 0;
2740 }
2741 
2742 static const struct uart_ops sci_uart_ops = {
2743 	.tx_empty	= sci_tx_empty,
2744 	.set_mctrl	= sci_set_mctrl,
2745 	.get_mctrl	= sci_get_mctrl,
2746 	.start_tx	= sci_start_tx,
2747 	.stop_tx	= sci_stop_tx,
2748 	.stop_rx	= sci_stop_rx,
2749 	.enable_ms	= sci_enable_ms,
2750 	.break_ctl	= sci_break_ctl,
2751 	.startup	= sci_startup,
2752 	.shutdown	= sci_shutdown,
2753 	.flush_buffer	= sci_flush_buffer,
2754 	.set_termios	= sci_set_termios,
2755 	.pm		= sci_pm,
2756 	.type		= sci_type,
2757 	.release_port	= sci_release_port,
2758 	.request_port	= sci_request_port,
2759 	.config_port	= sci_config_port,
2760 	.verify_port	= sci_verify_port,
2761 #ifdef CONFIG_CONSOLE_POLL
2762 	.poll_get_char	= sci_poll_get_char,
2763 	.poll_put_char	= sci_poll_put_char,
2764 #endif
2765 };
2766 
2767 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2768 {
2769 	const char *clk_names[] = {
2770 		[SCI_FCK] = "fck",
2771 		[SCI_SCK] = "sck",
2772 		[SCI_BRG_INT] = "brg_int",
2773 		[SCI_SCIF_CLK] = "scif_clk",
2774 	};
2775 	struct clk *clk;
2776 	unsigned int i;
2777 
2778 	if (sci_port->cfg->type == PORT_HSCIF)
2779 		clk_names[SCI_SCK] = "hsck";
2780 
2781 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2782 		clk = devm_clk_get(dev, clk_names[i]);
2783 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2784 			return -EPROBE_DEFER;
2785 
2786 		if (IS_ERR(clk) && i == SCI_FCK) {
2787 			/*
2788 			 * Not all SH platforms declare a clock lookup entry
2789 			 * for SCI devices, in which case we need to get the
2790 			 * global "peripheral_clk" clock.
2791 			 */
2792 			clk = devm_clk_get(dev, "peripheral_clk");
2793 			if (!IS_ERR(clk))
2794 				goto found;
2795 
2796 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2797 				PTR_ERR(clk));
2798 			return PTR_ERR(clk);
2799 		}
2800 
2801 found:
2802 		if (IS_ERR(clk))
2803 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2804 				PTR_ERR(clk));
2805 		else
2806 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2807 				clk, clk_get_rate(clk));
2808 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2809 	}
2810 	return 0;
2811 }
2812 
2813 static const struct sci_port_params *
2814 sci_probe_regmap(const struct plat_sci_port *cfg)
2815 {
2816 	unsigned int regtype;
2817 
2818 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2819 		return &sci_port_params[cfg->regtype];
2820 
2821 	switch (cfg->type) {
2822 	case PORT_SCI:
2823 		regtype = SCIx_SCI_REGTYPE;
2824 		break;
2825 	case PORT_IRDA:
2826 		regtype = SCIx_IRDA_REGTYPE;
2827 		break;
2828 	case PORT_SCIFA:
2829 		regtype = SCIx_SCIFA_REGTYPE;
2830 		break;
2831 	case PORT_SCIFB:
2832 		regtype = SCIx_SCIFB_REGTYPE;
2833 		break;
2834 	case PORT_SCIF:
2835 		/*
2836 		 * The SH-4 is a bit of a misnomer here, although that's
2837 		 * where this particular port layout originated. This
2838 		 * configuration (or some slight variation thereof)
2839 		 * remains the dominant model for all SCIFs.
2840 		 */
2841 		regtype = SCIx_SH4_SCIF_REGTYPE;
2842 		break;
2843 	case PORT_HSCIF:
2844 		regtype = SCIx_HSCIF_REGTYPE;
2845 		break;
2846 	default:
2847 		pr_err("Can't probe register map for given port\n");
2848 		return NULL;
2849 	}
2850 
2851 	return &sci_port_params[regtype];
2852 }
2853 
2854 static int sci_init_single(struct platform_device *dev,
2855 			   struct sci_port *sci_port, unsigned int index,
2856 			   const struct plat_sci_port *p, bool early)
2857 {
2858 	struct uart_port *port = &sci_port->port;
2859 	const struct resource *res;
2860 	unsigned int i;
2861 	int ret;
2862 
2863 	sci_port->cfg	= p;
2864 
2865 	port->ops	= &sci_uart_ops;
2866 	port->iotype	= UPIO_MEM;
2867 	port->line	= index;
2868 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2869 
2870 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2871 	if (res == NULL)
2872 		return -ENOMEM;
2873 
2874 	port->mapbase = res->start;
2875 	sci_port->reg_size = resource_size(res);
2876 
2877 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2878 		if (i)
2879 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2880 		else
2881 			sci_port->irqs[i] = platform_get_irq(dev, i);
2882 	}
2883 
2884 	/* The SCI generates several interrupts. They can be muxed together or
2885 	 * connected to different interrupt lines. In the muxed case only one
2886 	 * interrupt resource is specified as there is only one interrupt ID.
2887 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2888 	 * from the SCI, however those signals might have their own individual
2889 	 * interrupt ID numbers, or muxed together with another interrupt.
2890 	 */
2891 	if (sci_port->irqs[0] < 0)
2892 		return -ENXIO;
2893 
2894 	if (sci_port->irqs[1] < 0)
2895 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2896 			sci_port->irqs[i] = sci_port->irqs[0];
2897 
2898 	sci_port->params = sci_probe_regmap(p);
2899 	if (unlikely(sci_port->params == NULL))
2900 		return -EINVAL;
2901 
2902 	switch (p->type) {
2903 	case PORT_SCIFB:
2904 		sci_port->rx_trigger = 48;
2905 		break;
2906 	case PORT_HSCIF:
2907 		sci_port->rx_trigger = 64;
2908 		break;
2909 	case PORT_SCIFA:
2910 		sci_port->rx_trigger = 32;
2911 		break;
2912 	case PORT_SCIF:
2913 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2914 			/* RX triggering not implemented for this IP */
2915 			sci_port->rx_trigger = 1;
2916 		else
2917 			sci_port->rx_trigger = 8;
2918 		break;
2919 	default:
2920 		sci_port->rx_trigger = 1;
2921 		break;
2922 	}
2923 
2924 	sci_port->rx_fifo_timeout = 0;
2925 	sci_port->hscif_tot = 0;
2926 
2927 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2928 	 * match the SoC datasheet, this should be investigated. Let platform
2929 	 * data override the sampling rate for now.
2930 	 */
2931 	sci_port->sampling_rate_mask = p->sampling_rate
2932 				     ? SCI_SR(p->sampling_rate)
2933 				     : sci_port->params->sampling_rate_mask;
2934 
2935 	if (!early) {
2936 		ret = sci_init_clocks(sci_port, &dev->dev);
2937 		if (ret < 0)
2938 			return ret;
2939 
2940 		port->dev = &dev->dev;
2941 
2942 		pm_runtime_enable(&dev->dev);
2943 	}
2944 
2945 	port->type		= p->type;
2946 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2947 	port->fifosize		= sci_port->params->fifosize;
2948 
2949 	if (port->type == PORT_SCI) {
2950 		if (sci_port->reg_size >= 0x20)
2951 			port->regshift = 2;
2952 		else
2953 			port->regshift = 1;
2954 	}
2955 
2956 	/*
2957 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2958 	 * for the multi-IRQ ports, which is where we are primarily
2959 	 * concerned with the shutdown path synchronization.
2960 	 *
2961 	 * For the muxed case there's nothing more to do.
2962 	 */
2963 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2964 	port->irqflags		= 0;
2965 
2966 	port->serial_in		= sci_serial_in;
2967 	port->serial_out	= sci_serial_out;
2968 
2969 	return 0;
2970 }
2971 
2972 static void sci_cleanup_single(struct sci_port *port)
2973 {
2974 	pm_runtime_disable(port->port.dev);
2975 }
2976 
2977 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2978     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2979 static void serial_console_putchar(struct uart_port *port, int ch)
2980 {
2981 	sci_poll_put_char(port, ch);
2982 }
2983 
2984 /*
2985  *	Print a string to the serial port trying not to disturb
2986  *	any possible real use of the port...
2987  */
2988 static void serial_console_write(struct console *co, const char *s,
2989 				 unsigned count)
2990 {
2991 	struct sci_port *sci_port = &sci_ports[co->index];
2992 	struct uart_port *port = &sci_port->port;
2993 	unsigned short bits, ctrl, ctrl_temp;
2994 	unsigned long flags;
2995 	int locked = 1;
2996 
2997 	if (port->sysrq)
2998 		locked = 0;
2999 	else if (oops_in_progress)
3000 		locked = spin_trylock_irqsave(&port->lock, flags);
3001 	else
3002 		spin_lock_irqsave(&port->lock, flags);
3003 
3004 	/* first save SCSCR then disable interrupts, keep clock source */
3005 	ctrl = serial_port_in(port, SCSCR);
3006 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3007 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3008 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3009 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3010 
3011 	uart_console_write(port, s, count, serial_console_putchar);
3012 
3013 	/* wait until fifo is empty and last bit has been transmitted */
3014 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3015 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3016 		cpu_relax();
3017 
3018 	/* restore the SCSCR */
3019 	serial_port_out(port, SCSCR, ctrl);
3020 
3021 	if (locked)
3022 		spin_unlock_irqrestore(&port->lock, flags);
3023 }
3024 
3025 static int serial_console_setup(struct console *co, char *options)
3026 {
3027 	struct sci_port *sci_port;
3028 	struct uart_port *port;
3029 	int baud = 115200;
3030 	int bits = 8;
3031 	int parity = 'n';
3032 	int flow = 'n';
3033 	int ret;
3034 
3035 	/*
3036 	 * Refuse to handle any bogus ports.
3037 	 */
3038 	if (co->index < 0 || co->index >= SCI_NPORTS)
3039 		return -ENODEV;
3040 
3041 	sci_port = &sci_ports[co->index];
3042 	port = &sci_port->port;
3043 
3044 	/*
3045 	 * Refuse to handle uninitialized ports.
3046 	 */
3047 	if (!port->ops)
3048 		return -ENODEV;
3049 
3050 	ret = sci_remap_port(port);
3051 	if (unlikely(ret != 0))
3052 		return ret;
3053 
3054 	if (options)
3055 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3056 
3057 	return uart_set_options(port, co, baud, parity, bits, flow);
3058 }
3059 
3060 static struct console serial_console = {
3061 	.name		= "ttySC",
3062 	.device		= uart_console_device,
3063 	.write		= serial_console_write,
3064 	.setup		= serial_console_setup,
3065 	.flags		= CON_PRINTBUFFER,
3066 	.index		= -1,
3067 	.data		= &sci_uart_driver,
3068 };
3069 
3070 #ifdef CONFIG_SUPERH
3071 static struct console early_serial_console = {
3072 	.name           = "early_ttySC",
3073 	.write          = serial_console_write,
3074 	.flags          = CON_PRINTBUFFER,
3075 	.index		= -1,
3076 };
3077 
3078 static char early_serial_buf[32];
3079 
3080 static int sci_probe_earlyprintk(struct platform_device *pdev)
3081 {
3082 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3083 
3084 	if (early_serial_console.data)
3085 		return -EEXIST;
3086 
3087 	early_serial_console.index = pdev->id;
3088 
3089 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3090 
3091 	serial_console_setup(&early_serial_console, early_serial_buf);
3092 
3093 	if (!strstr(early_serial_buf, "keep"))
3094 		early_serial_console.flags |= CON_BOOT;
3095 
3096 	register_console(&early_serial_console);
3097 	return 0;
3098 }
3099 #endif
3100 
3101 #define SCI_CONSOLE	(&serial_console)
3102 
3103 #else
3104 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3105 {
3106 	return -EINVAL;
3107 }
3108 
3109 #define SCI_CONSOLE	NULL
3110 
3111 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3112 
3113 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3114 
3115 static DEFINE_MUTEX(sci_uart_registration_lock);
3116 static struct uart_driver sci_uart_driver = {
3117 	.owner		= THIS_MODULE,
3118 	.driver_name	= "sci",
3119 	.dev_name	= "ttySC",
3120 	.major		= SCI_MAJOR,
3121 	.minor		= SCI_MINOR_START,
3122 	.nr		= SCI_NPORTS,
3123 	.cons		= SCI_CONSOLE,
3124 };
3125 
3126 static int sci_remove(struct platform_device *dev)
3127 {
3128 	struct sci_port *port = platform_get_drvdata(dev);
3129 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3130 
3131 	sci_ports_in_use &= ~BIT(port->port.line);
3132 	uart_remove_one_port(&sci_uart_driver, &port->port);
3133 
3134 	sci_cleanup_single(port);
3135 
3136 	if (port->port.fifosize > 1)
3137 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3138 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3139 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3140 
3141 	return 0;
3142 }
3143 
3144 
3145 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3146 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3147 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3148 
3149 static const struct of_device_id of_sci_match[] = {
3150 	/* SoC-specific types */
3151 	{
3152 		.compatible = "renesas,scif-r7s72100",
3153 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3154 	},
3155 	{
3156 		.compatible = "renesas,scif-r7s9210",
3157 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3158 	},
3159 	{
3160 		.compatible = "renesas,scif-r9a07g044",
3161 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3162 	},
3163 	/* Family-specific types */
3164 	{
3165 		.compatible = "renesas,rcar-gen1-scif",
3166 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3167 	}, {
3168 		.compatible = "renesas,rcar-gen2-scif",
3169 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3170 	}, {
3171 		.compatible = "renesas,rcar-gen3-scif",
3172 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3173 	}, {
3174 		.compatible = "renesas,rcar-gen4-scif",
3175 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3176 	},
3177 	/* Generic types */
3178 	{
3179 		.compatible = "renesas,scif",
3180 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3181 	}, {
3182 		.compatible = "renesas,scifa",
3183 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3184 	}, {
3185 		.compatible = "renesas,scifb",
3186 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3187 	}, {
3188 		.compatible = "renesas,hscif",
3189 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3190 	}, {
3191 		.compatible = "renesas,sci",
3192 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3193 	}, {
3194 		/* Terminator */
3195 	},
3196 };
3197 MODULE_DEVICE_TABLE(of, of_sci_match);
3198 
3199 static void sci_reset_control_assert(void *data)
3200 {
3201 	reset_control_assert(data);
3202 }
3203 
3204 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3205 					  unsigned int *dev_id)
3206 {
3207 	struct device_node *np = pdev->dev.of_node;
3208 	struct reset_control *rstc;
3209 	struct plat_sci_port *p;
3210 	struct sci_port *sp;
3211 	const void *data;
3212 	int id, ret;
3213 
3214 	if (!IS_ENABLED(CONFIG_OF) || !np)
3215 		return ERR_PTR(-EINVAL);
3216 
3217 	data = of_device_get_match_data(&pdev->dev);
3218 
3219 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3220 	if (IS_ERR(rstc))
3221 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3222 					     "failed to get reset ctrl\n"));
3223 
3224 	ret = reset_control_deassert(rstc);
3225 	if (ret) {
3226 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3227 		return ERR_PTR(ret);
3228 	}
3229 
3230 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3231 	if (ret) {
3232 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3233 			ret);
3234 		return ERR_PTR(ret);
3235 	}
3236 
3237 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3238 	if (!p)
3239 		return ERR_PTR(-ENOMEM);
3240 
3241 	/* Get the line number from the aliases node. */
3242 	id = of_alias_get_id(np, "serial");
3243 	if (id < 0 && ~sci_ports_in_use)
3244 		id = ffz(sci_ports_in_use);
3245 	if (id < 0) {
3246 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3247 		return ERR_PTR(-EINVAL);
3248 	}
3249 	if (id >= ARRAY_SIZE(sci_ports)) {
3250 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3251 		return ERR_PTR(-EINVAL);
3252 	}
3253 
3254 	sp = &sci_ports[id];
3255 	*dev_id = id;
3256 
3257 	p->type = SCI_OF_TYPE(data);
3258 	p->regtype = SCI_OF_REGTYPE(data);
3259 
3260 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3261 
3262 	return p;
3263 }
3264 
3265 static int sci_probe_single(struct platform_device *dev,
3266 				      unsigned int index,
3267 				      struct plat_sci_port *p,
3268 				      struct sci_port *sciport)
3269 {
3270 	int ret;
3271 
3272 	/* Sanity check */
3273 	if (unlikely(index >= SCI_NPORTS)) {
3274 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3275 			   index+1, SCI_NPORTS);
3276 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3277 		return -EINVAL;
3278 	}
3279 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3280 	if (sci_ports_in_use & BIT(index))
3281 		return -EBUSY;
3282 
3283 	mutex_lock(&sci_uart_registration_lock);
3284 	if (!sci_uart_driver.state) {
3285 		ret = uart_register_driver(&sci_uart_driver);
3286 		if (ret) {
3287 			mutex_unlock(&sci_uart_registration_lock);
3288 			return ret;
3289 		}
3290 	}
3291 	mutex_unlock(&sci_uart_registration_lock);
3292 
3293 	ret = sci_init_single(dev, sciport, index, p, false);
3294 	if (ret)
3295 		return ret;
3296 
3297 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3298 	if (IS_ERR(sciport->gpios))
3299 		return PTR_ERR(sciport->gpios);
3300 
3301 	if (sciport->has_rtscts) {
3302 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3303 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3304 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3305 			return -EINVAL;
3306 		}
3307 		sciport->port.flags |= UPF_HARD_FLOW;
3308 	}
3309 
3310 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3311 	if (ret) {
3312 		sci_cleanup_single(sciport);
3313 		return ret;
3314 	}
3315 
3316 	return 0;
3317 }
3318 
3319 static int sci_probe(struct platform_device *dev)
3320 {
3321 	struct plat_sci_port *p;
3322 	struct sci_port *sp;
3323 	unsigned int dev_id;
3324 	int ret;
3325 
3326 	/*
3327 	 * If we've come here via earlyprintk initialization, head off to
3328 	 * the special early probe. We don't have sufficient device state
3329 	 * to make it beyond this yet.
3330 	 */
3331 #ifdef CONFIG_SUPERH
3332 	if (is_sh_early_platform_device(dev))
3333 		return sci_probe_earlyprintk(dev);
3334 #endif
3335 
3336 	if (dev->dev.of_node) {
3337 		p = sci_parse_dt(dev, &dev_id);
3338 		if (IS_ERR(p))
3339 			return PTR_ERR(p);
3340 	} else {
3341 		p = dev->dev.platform_data;
3342 		if (p == NULL) {
3343 			dev_err(&dev->dev, "no platform data supplied\n");
3344 			return -EINVAL;
3345 		}
3346 
3347 		dev_id = dev->id;
3348 	}
3349 
3350 	sp = &sci_ports[dev_id];
3351 	platform_set_drvdata(dev, sp);
3352 
3353 	ret = sci_probe_single(dev, dev_id, p, sp);
3354 	if (ret)
3355 		return ret;
3356 
3357 	if (sp->port.fifosize > 1) {
3358 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3359 		if (ret)
3360 			return ret;
3361 	}
3362 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3363 	    sp->port.type == PORT_HSCIF) {
3364 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3365 		if (ret) {
3366 			if (sp->port.fifosize > 1) {
3367 				device_remove_file(&dev->dev,
3368 						   &dev_attr_rx_fifo_trigger);
3369 			}
3370 			return ret;
3371 		}
3372 	}
3373 
3374 #ifdef CONFIG_SH_STANDARD_BIOS
3375 	sh_bios_gdb_detach();
3376 #endif
3377 
3378 	sci_ports_in_use |= BIT(dev_id);
3379 	return 0;
3380 }
3381 
3382 static __maybe_unused int sci_suspend(struct device *dev)
3383 {
3384 	struct sci_port *sport = dev_get_drvdata(dev);
3385 
3386 	if (sport)
3387 		uart_suspend_port(&sci_uart_driver, &sport->port);
3388 
3389 	return 0;
3390 }
3391 
3392 static __maybe_unused int sci_resume(struct device *dev)
3393 {
3394 	struct sci_port *sport = dev_get_drvdata(dev);
3395 
3396 	if (sport)
3397 		uart_resume_port(&sci_uart_driver, &sport->port);
3398 
3399 	return 0;
3400 }
3401 
3402 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3403 
3404 static struct platform_driver sci_driver = {
3405 	.probe		= sci_probe,
3406 	.remove		= sci_remove,
3407 	.driver		= {
3408 		.name	= "sh-sci",
3409 		.pm	= &sci_dev_pm_ops,
3410 		.of_match_table = of_match_ptr(of_sci_match),
3411 	},
3412 };
3413 
3414 static int __init sci_init(void)
3415 {
3416 	pr_info("%s\n", banner);
3417 
3418 	return platform_driver_register(&sci_driver);
3419 }
3420 
3421 static void __exit sci_exit(void)
3422 {
3423 	platform_driver_unregister(&sci_driver);
3424 
3425 	if (sci_uart_driver.state)
3426 		uart_unregister_driver(&sci_uart_driver);
3427 }
3428 
3429 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3430 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3431 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3432 #endif
3433 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3434 static struct plat_sci_port port_cfg __initdata;
3435 
3436 static int __init early_console_setup(struct earlycon_device *device,
3437 				      int type)
3438 {
3439 	if (!device->port.membase)
3440 		return -ENODEV;
3441 
3442 	device->port.serial_in = sci_serial_in;
3443 	device->port.serial_out	= sci_serial_out;
3444 	device->port.type = type;
3445 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3446 	port_cfg.type = type;
3447 	sci_ports[0].cfg = &port_cfg;
3448 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3449 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3450 	sci_serial_out(&sci_ports[0].port, SCSCR,
3451 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3452 
3453 	device->con->write = serial_console_write;
3454 	return 0;
3455 }
3456 static int __init sci_early_console_setup(struct earlycon_device *device,
3457 					  const char *opt)
3458 {
3459 	return early_console_setup(device, PORT_SCI);
3460 }
3461 static int __init scif_early_console_setup(struct earlycon_device *device,
3462 					  const char *opt)
3463 {
3464 	return early_console_setup(device, PORT_SCIF);
3465 }
3466 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3467 					  const char *opt)
3468 {
3469 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3470 	return early_console_setup(device, PORT_SCIF);
3471 }
3472 
3473 static int __init scifa_early_console_setup(struct earlycon_device *device,
3474 					  const char *opt)
3475 {
3476 	return early_console_setup(device, PORT_SCIFA);
3477 }
3478 static int __init scifb_early_console_setup(struct earlycon_device *device,
3479 					  const char *opt)
3480 {
3481 	return early_console_setup(device, PORT_SCIFB);
3482 }
3483 static int __init hscif_early_console_setup(struct earlycon_device *device,
3484 					  const char *opt)
3485 {
3486 	return early_console_setup(device, PORT_HSCIF);
3487 }
3488 
3489 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3490 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3491 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3492 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3493 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3494 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3495 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3496 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3497 
3498 module_init(sci_init);
3499 module_exit(sci_exit);
3500 
3501 MODULE_LICENSE("GPL");
3502 MODULE_ALIAS("platform:sh-sci");
3503 MODULE_AUTHOR("Paul Mundt");
3504 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3505