xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision 2169e6da)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 #define SUPPORT_SYSRQ
20 #endif
21 
22 #undef DEBUG
23 
24 #include <linux/clk.h>
25 #include <linux/console.h>
26 #include <linux/ctype.h>
27 #include <linux/cpufreq.h>
28 #include <linux/delay.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/err.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/ioport.h>
36 #include <linux/ktime.h>
37 #include <linux/major.h>
38 #include <linux/module.h>
39 #include <linux/mm.h>
40 #include <linux/of.h>
41 #include <linux/of_device.h>
42 #include <linux/platform_device.h>
43 #include <linux/pm_runtime.h>
44 #include <linux/scatterlist.h>
45 #include <linux/serial.h>
46 #include <linux/serial_sci.h>
47 #include <linux/sh_dma.h>
48 #include <linux/slab.h>
49 #include <linux/string.h>
50 #include <linux/sysrq.h>
51 #include <linux/timer.h>
52 #include <linux/tty.h>
53 #include <linux/tty_flip.h>
54 
55 #ifdef CONFIG_SUPERH
56 #include <asm/sh_bios.h>
57 #endif
58 
59 #include "serial_mctrl_gpio.h"
60 #include "sh-sci.h"
61 
62 /* Offsets into the sci_port->irqs array */
63 enum {
64 	SCIx_ERI_IRQ,
65 	SCIx_RXI_IRQ,
66 	SCIx_TXI_IRQ,
67 	SCIx_BRI_IRQ,
68 	SCIx_DRI_IRQ,
69 	SCIx_TEI_IRQ,
70 	SCIx_NR_IRQS,
71 
72 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
73 };
74 
75 #define SCIx_IRQ_IS_MUXED(port)			\
76 	((port)->irqs[SCIx_ERI_IRQ] ==	\
77 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
78 	((port)->irqs[SCIx_ERI_IRQ] &&	\
79 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
80 
81 enum SCI_CLKS {
82 	SCI_FCK,		/* Functional Clock */
83 	SCI_SCK,		/* Optional External Clock */
84 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
85 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
86 	SCI_NUM_CLKS
87 };
88 
89 /* Bit x set means sampling rate x + 1 is supported */
90 #define SCI_SR(x)		BIT((x) - 1)
91 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
92 
93 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
94 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
95 				SCI_SR(19) | SCI_SR(27)
96 
97 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
98 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
99 
100 /* Iterate over all supported sampling rates, from high to low */
101 #define for_each_sr(_sr, _port)						\
102 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
103 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
104 
105 struct plat_sci_reg {
106 	u8 offset, size;
107 };
108 
109 struct sci_port_params {
110 	const struct plat_sci_reg regs[SCIx_NR_REGS];
111 	unsigned int fifosize;
112 	unsigned int overrun_reg;
113 	unsigned int overrun_mask;
114 	unsigned int sampling_rate_mask;
115 	unsigned int error_mask;
116 	unsigned int error_clear;
117 };
118 
119 struct sci_port {
120 	struct uart_port	port;
121 
122 	/* Platform configuration */
123 	const struct sci_port_params *params;
124 	const struct plat_sci_port *cfg;
125 	unsigned int		sampling_rate_mask;
126 	resource_size_t		reg_size;
127 	struct mctrl_gpios	*gpios;
128 
129 	/* Clocks */
130 	struct clk		*clks[SCI_NUM_CLKS];
131 	unsigned long		clk_rates[SCI_NUM_CLKS];
132 
133 	int			irqs[SCIx_NR_IRQS];
134 	char			*irqstr[SCIx_NR_IRQS];
135 
136 	struct dma_chan			*chan_tx;
137 	struct dma_chan			*chan_rx;
138 
139 #ifdef CONFIG_SERIAL_SH_SCI_DMA
140 	struct dma_chan			*chan_tx_saved;
141 	struct dma_chan			*chan_rx_saved;
142 	dma_cookie_t			cookie_tx;
143 	dma_cookie_t			cookie_rx[2];
144 	dma_cookie_t			active_rx;
145 	dma_addr_t			tx_dma_addr;
146 	unsigned int			tx_dma_len;
147 	struct scatterlist		sg_rx[2];
148 	void				*rx_buf[2];
149 	size_t				buf_len_rx;
150 	struct work_struct		work_tx;
151 	struct hrtimer			rx_timer;
152 	unsigned int			rx_timeout;	/* microseconds */
153 #endif
154 	unsigned int			rx_frame;
155 	int				rx_trigger;
156 	struct timer_list		rx_fifo_timer;
157 	int				rx_fifo_timeout;
158 	u16				hscif_tot;
159 
160 	bool has_rtscts;
161 	bool autorts;
162 };
163 
164 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
165 
166 static struct sci_port sci_ports[SCI_NPORTS];
167 static unsigned long sci_ports_in_use;
168 static struct uart_driver sci_uart_driver;
169 
170 static inline struct sci_port *
171 to_sci_port(struct uart_port *uart)
172 {
173 	return container_of(uart, struct sci_port, port);
174 }
175 
176 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
177 	/*
178 	 * Common SCI definitions, dependent on the port's regshift
179 	 * value.
180 	 */
181 	[SCIx_SCI_REGTYPE] = {
182 		.regs = {
183 			[SCSMR]		= { 0x00,  8 },
184 			[SCBRR]		= { 0x01,  8 },
185 			[SCSCR]		= { 0x02,  8 },
186 			[SCxTDR]	= { 0x03,  8 },
187 			[SCxSR]		= { 0x04,  8 },
188 			[SCxRDR]	= { 0x05,  8 },
189 		},
190 		.fifosize = 1,
191 		.overrun_reg = SCxSR,
192 		.overrun_mask = SCI_ORER,
193 		.sampling_rate_mask = SCI_SR(32),
194 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
195 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
196 	},
197 
198 	/*
199 	 * Common definitions for legacy IrDA ports.
200 	 */
201 	[SCIx_IRDA_REGTYPE] = {
202 		.regs = {
203 			[SCSMR]		= { 0x00,  8 },
204 			[SCBRR]		= { 0x02,  8 },
205 			[SCSCR]		= { 0x04,  8 },
206 			[SCxTDR]	= { 0x06,  8 },
207 			[SCxSR]		= { 0x08, 16 },
208 			[SCxRDR]	= { 0x0a,  8 },
209 			[SCFCR]		= { 0x0c,  8 },
210 			[SCFDR]		= { 0x0e, 16 },
211 		},
212 		.fifosize = 1,
213 		.overrun_reg = SCxSR,
214 		.overrun_mask = SCI_ORER,
215 		.sampling_rate_mask = SCI_SR(32),
216 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
217 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
218 	},
219 
220 	/*
221 	 * Common SCIFA definitions.
222 	 */
223 	[SCIx_SCIFA_REGTYPE] = {
224 		.regs = {
225 			[SCSMR]		= { 0x00, 16 },
226 			[SCBRR]		= { 0x04,  8 },
227 			[SCSCR]		= { 0x08, 16 },
228 			[SCxTDR]	= { 0x20,  8 },
229 			[SCxSR]		= { 0x14, 16 },
230 			[SCxRDR]	= { 0x24,  8 },
231 			[SCFCR]		= { 0x18, 16 },
232 			[SCFDR]		= { 0x1c, 16 },
233 			[SCPCR]		= { 0x30, 16 },
234 			[SCPDR]		= { 0x34, 16 },
235 		},
236 		.fifosize = 64,
237 		.overrun_reg = SCxSR,
238 		.overrun_mask = SCIFA_ORER,
239 		.sampling_rate_mask = SCI_SR_SCIFAB,
240 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
241 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
242 	},
243 
244 	/*
245 	 * Common SCIFB definitions.
246 	 */
247 	[SCIx_SCIFB_REGTYPE] = {
248 		.regs = {
249 			[SCSMR]		= { 0x00, 16 },
250 			[SCBRR]		= { 0x04,  8 },
251 			[SCSCR]		= { 0x08, 16 },
252 			[SCxTDR]	= { 0x40,  8 },
253 			[SCxSR]		= { 0x14, 16 },
254 			[SCxRDR]	= { 0x60,  8 },
255 			[SCFCR]		= { 0x18, 16 },
256 			[SCTFDR]	= { 0x38, 16 },
257 			[SCRFDR]	= { 0x3c, 16 },
258 			[SCPCR]		= { 0x30, 16 },
259 			[SCPDR]		= { 0x34, 16 },
260 		},
261 		.fifosize = 256,
262 		.overrun_reg = SCxSR,
263 		.overrun_mask = SCIFA_ORER,
264 		.sampling_rate_mask = SCI_SR_SCIFAB,
265 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
266 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
267 	},
268 
269 	/*
270 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
271 	 * count registers.
272 	 */
273 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
274 		.regs = {
275 			[SCSMR]		= { 0x00, 16 },
276 			[SCBRR]		= { 0x04,  8 },
277 			[SCSCR]		= { 0x08, 16 },
278 			[SCxTDR]	= { 0x0c,  8 },
279 			[SCxSR]		= { 0x10, 16 },
280 			[SCxRDR]	= { 0x14,  8 },
281 			[SCFCR]		= { 0x18, 16 },
282 			[SCFDR]		= { 0x1c, 16 },
283 			[SCSPTR]	= { 0x20, 16 },
284 			[SCLSR]		= { 0x24, 16 },
285 		},
286 		.fifosize = 16,
287 		.overrun_reg = SCLSR,
288 		.overrun_mask = SCLSR_ORER,
289 		.sampling_rate_mask = SCI_SR(32),
290 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
291 		.error_clear = SCIF_ERROR_CLEAR,
292 	},
293 
294 	/*
295 	 * The "SCIFA" that is in RZ/T and RZ/A2.
296 	 * It looks like a normal SCIF with FIFO data, but with a
297 	 * compressed address space. Also, the break out of interrupts
298 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
299 	 */
300 	[SCIx_RZ_SCIFA_REGTYPE] = {
301 		.regs = {
302 			[SCSMR]		= { 0x00, 16 },
303 			[SCBRR]		= { 0x02,  8 },
304 			[SCSCR]		= { 0x04, 16 },
305 			[SCxTDR]	= { 0x06,  8 },
306 			[SCxSR]		= { 0x08, 16 },
307 			[SCxRDR]	= { 0x0A,  8 },
308 			[SCFCR]		= { 0x0C, 16 },
309 			[SCFDR]		= { 0x0E, 16 },
310 			[SCSPTR]	= { 0x10, 16 },
311 			[SCLSR]		= { 0x12, 16 },
312 		},
313 		.fifosize = 16,
314 		.overrun_reg = SCLSR,
315 		.overrun_mask = SCLSR_ORER,
316 		.sampling_rate_mask = SCI_SR(32),
317 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
318 		.error_clear = SCIF_ERROR_CLEAR,
319 	},
320 
321 	/*
322 	 * Common SH-3 SCIF definitions.
323 	 */
324 	[SCIx_SH3_SCIF_REGTYPE] = {
325 		.regs = {
326 			[SCSMR]		= { 0x00,  8 },
327 			[SCBRR]		= { 0x02,  8 },
328 			[SCSCR]		= { 0x04,  8 },
329 			[SCxTDR]	= { 0x06,  8 },
330 			[SCxSR]		= { 0x08, 16 },
331 			[SCxRDR]	= { 0x0a,  8 },
332 			[SCFCR]		= { 0x0c,  8 },
333 			[SCFDR]		= { 0x0e, 16 },
334 		},
335 		.fifosize = 16,
336 		.overrun_reg = SCLSR,
337 		.overrun_mask = SCLSR_ORER,
338 		.sampling_rate_mask = SCI_SR(32),
339 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
340 		.error_clear = SCIF_ERROR_CLEAR,
341 	},
342 
343 	/*
344 	 * Common SH-4(A) SCIF(B) definitions.
345 	 */
346 	[SCIx_SH4_SCIF_REGTYPE] = {
347 		.regs = {
348 			[SCSMR]		= { 0x00, 16 },
349 			[SCBRR]		= { 0x04,  8 },
350 			[SCSCR]		= { 0x08, 16 },
351 			[SCxTDR]	= { 0x0c,  8 },
352 			[SCxSR]		= { 0x10, 16 },
353 			[SCxRDR]	= { 0x14,  8 },
354 			[SCFCR]		= { 0x18, 16 },
355 			[SCFDR]		= { 0x1c, 16 },
356 			[SCSPTR]	= { 0x20, 16 },
357 			[SCLSR]		= { 0x24, 16 },
358 		},
359 		.fifosize = 16,
360 		.overrun_reg = SCLSR,
361 		.overrun_mask = SCLSR_ORER,
362 		.sampling_rate_mask = SCI_SR(32),
363 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
364 		.error_clear = SCIF_ERROR_CLEAR,
365 	},
366 
367 	/*
368 	 * Common SCIF definitions for ports with a Baud Rate Generator for
369 	 * External Clock (BRG).
370 	 */
371 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
372 		.regs = {
373 			[SCSMR]		= { 0x00, 16 },
374 			[SCBRR]		= { 0x04,  8 },
375 			[SCSCR]		= { 0x08, 16 },
376 			[SCxTDR]	= { 0x0c,  8 },
377 			[SCxSR]		= { 0x10, 16 },
378 			[SCxRDR]	= { 0x14,  8 },
379 			[SCFCR]		= { 0x18, 16 },
380 			[SCFDR]		= { 0x1c, 16 },
381 			[SCSPTR]	= { 0x20, 16 },
382 			[SCLSR]		= { 0x24, 16 },
383 			[SCDL]		= { 0x30, 16 },
384 			[SCCKS]		= { 0x34, 16 },
385 		},
386 		.fifosize = 16,
387 		.overrun_reg = SCLSR,
388 		.overrun_mask = SCLSR_ORER,
389 		.sampling_rate_mask = SCI_SR(32),
390 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
391 		.error_clear = SCIF_ERROR_CLEAR,
392 	},
393 
394 	/*
395 	 * Common HSCIF definitions.
396 	 */
397 	[SCIx_HSCIF_REGTYPE] = {
398 		.regs = {
399 			[SCSMR]		= { 0x00, 16 },
400 			[SCBRR]		= { 0x04,  8 },
401 			[SCSCR]		= { 0x08, 16 },
402 			[SCxTDR]	= { 0x0c,  8 },
403 			[SCxSR]		= { 0x10, 16 },
404 			[SCxRDR]	= { 0x14,  8 },
405 			[SCFCR]		= { 0x18, 16 },
406 			[SCFDR]		= { 0x1c, 16 },
407 			[SCSPTR]	= { 0x20, 16 },
408 			[SCLSR]		= { 0x24, 16 },
409 			[HSSRR]		= { 0x40, 16 },
410 			[SCDL]		= { 0x30, 16 },
411 			[SCCKS]		= { 0x34, 16 },
412 			[HSRTRGR]	= { 0x54, 16 },
413 			[HSTTRGR]	= { 0x58, 16 },
414 		},
415 		.fifosize = 128,
416 		.overrun_reg = SCLSR,
417 		.overrun_mask = SCLSR_ORER,
418 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
419 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
420 		.error_clear = SCIF_ERROR_CLEAR,
421 	},
422 
423 	/*
424 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
425 	 * register.
426 	 */
427 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
428 		.regs = {
429 			[SCSMR]		= { 0x00, 16 },
430 			[SCBRR]		= { 0x04,  8 },
431 			[SCSCR]		= { 0x08, 16 },
432 			[SCxTDR]	= { 0x0c,  8 },
433 			[SCxSR]		= { 0x10, 16 },
434 			[SCxRDR]	= { 0x14,  8 },
435 			[SCFCR]		= { 0x18, 16 },
436 			[SCFDR]		= { 0x1c, 16 },
437 			[SCLSR]		= { 0x24, 16 },
438 		},
439 		.fifosize = 16,
440 		.overrun_reg = SCLSR,
441 		.overrun_mask = SCLSR_ORER,
442 		.sampling_rate_mask = SCI_SR(32),
443 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
444 		.error_clear = SCIF_ERROR_CLEAR,
445 	},
446 
447 	/*
448 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
449 	 * count registers.
450 	 */
451 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
452 		.regs = {
453 			[SCSMR]		= { 0x00, 16 },
454 			[SCBRR]		= { 0x04,  8 },
455 			[SCSCR]		= { 0x08, 16 },
456 			[SCxTDR]	= { 0x0c,  8 },
457 			[SCxSR]		= { 0x10, 16 },
458 			[SCxRDR]	= { 0x14,  8 },
459 			[SCFCR]		= { 0x18, 16 },
460 			[SCFDR]		= { 0x1c, 16 },
461 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
462 			[SCRFDR]	= { 0x20, 16 },
463 			[SCSPTR]	= { 0x24, 16 },
464 			[SCLSR]		= { 0x28, 16 },
465 		},
466 		.fifosize = 16,
467 		.overrun_reg = SCLSR,
468 		.overrun_mask = SCLSR_ORER,
469 		.sampling_rate_mask = SCI_SR(32),
470 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
471 		.error_clear = SCIF_ERROR_CLEAR,
472 	},
473 
474 	/*
475 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
476 	 * registers.
477 	 */
478 	[SCIx_SH7705_SCIF_REGTYPE] = {
479 		.regs = {
480 			[SCSMR]		= { 0x00, 16 },
481 			[SCBRR]		= { 0x04,  8 },
482 			[SCSCR]		= { 0x08, 16 },
483 			[SCxTDR]	= { 0x20,  8 },
484 			[SCxSR]		= { 0x14, 16 },
485 			[SCxRDR]	= { 0x24,  8 },
486 			[SCFCR]		= { 0x18, 16 },
487 			[SCFDR]		= { 0x1c, 16 },
488 		},
489 		.fifosize = 64,
490 		.overrun_reg = SCxSR,
491 		.overrun_mask = SCIFA_ORER,
492 		.sampling_rate_mask = SCI_SR(16),
493 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
494 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
495 	},
496 };
497 
498 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
499 
500 /*
501  * The "offset" here is rather misleading, in that it refers to an enum
502  * value relative to the port mapping rather than the fixed offset
503  * itself, which needs to be manually retrieved from the platform's
504  * register map for the given port.
505  */
506 static unsigned int sci_serial_in(struct uart_port *p, int offset)
507 {
508 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
509 
510 	if (reg->size == 8)
511 		return ioread8(p->membase + (reg->offset << p->regshift));
512 	else if (reg->size == 16)
513 		return ioread16(p->membase + (reg->offset << p->regshift));
514 	else
515 		WARN(1, "Invalid register access\n");
516 
517 	return 0;
518 }
519 
520 static void sci_serial_out(struct uart_port *p, int offset, int value)
521 {
522 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
523 
524 	if (reg->size == 8)
525 		iowrite8(value, p->membase + (reg->offset << p->regshift));
526 	else if (reg->size == 16)
527 		iowrite16(value, p->membase + (reg->offset << p->regshift));
528 	else
529 		WARN(1, "Invalid register access\n");
530 }
531 
532 static void sci_port_enable(struct sci_port *sci_port)
533 {
534 	unsigned int i;
535 
536 	if (!sci_port->port.dev)
537 		return;
538 
539 	pm_runtime_get_sync(sci_port->port.dev);
540 
541 	for (i = 0; i < SCI_NUM_CLKS; i++) {
542 		clk_prepare_enable(sci_port->clks[i]);
543 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
544 	}
545 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
546 }
547 
548 static void sci_port_disable(struct sci_port *sci_port)
549 {
550 	unsigned int i;
551 
552 	if (!sci_port->port.dev)
553 		return;
554 
555 	for (i = SCI_NUM_CLKS; i-- > 0; )
556 		clk_disable_unprepare(sci_port->clks[i]);
557 
558 	pm_runtime_put_sync(sci_port->port.dev);
559 }
560 
561 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
562 {
563 	/*
564 	 * Not all ports (such as SCIFA) will support REIE. Rather than
565 	 * special-casing the port type, we check the port initialization
566 	 * IRQ enable mask to see whether the IRQ is desired at all. If
567 	 * it's unset, it's logically inferred that there's no point in
568 	 * testing for it.
569 	 */
570 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
571 }
572 
573 static void sci_start_tx(struct uart_port *port)
574 {
575 	struct sci_port *s = to_sci_port(port);
576 	unsigned short ctrl;
577 
578 #ifdef CONFIG_SERIAL_SH_SCI_DMA
579 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
580 		u16 new, scr = serial_port_in(port, SCSCR);
581 		if (s->chan_tx)
582 			new = scr | SCSCR_TDRQE;
583 		else
584 			new = scr & ~SCSCR_TDRQE;
585 		if (new != scr)
586 			serial_port_out(port, SCSCR, new);
587 	}
588 
589 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
590 	    dma_submit_error(s->cookie_tx)) {
591 		s->cookie_tx = 0;
592 		schedule_work(&s->work_tx);
593 	}
594 #endif
595 
596 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
597 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
598 		ctrl = serial_port_in(port, SCSCR);
599 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
600 	}
601 }
602 
603 static void sci_stop_tx(struct uart_port *port)
604 {
605 	unsigned short ctrl;
606 
607 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
608 	ctrl = serial_port_in(port, SCSCR);
609 
610 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
611 		ctrl &= ~SCSCR_TDRQE;
612 
613 	ctrl &= ~SCSCR_TIE;
614 
615 	serial_port_out(port, SCSCR, ctrl);
616 }
617 
618 static void sci_start_rx(struct uart_port *port)
619 {
620 	unsigned short ctrl;
621 
622 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
623 
624 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
625 		ctrl &= ~SCSCR_RDRQE;
626 
627 	serial_port_out(port, SCSCR, ctrl);
628 }
629 
630 static void sci_stop_rx(struct uart_port *port)
631 {
632 	unsigned short ctrl;
633 
634 	ctrl = serial_port_in(port, SCSCR);
635 
636 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
637 		ctrl &= ~SCSCR_RDRQE;
638 
639 	ctrl &= ~port_rx_irq_mask(port);
640 
641 	serial_port_out(port, SCSCR, ctrl);
642 }
643 
644 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
645 {
646 	if (port->type == PORT_SCI) {
647 		/* Just store the mask */
648 		serial_port_out(port, SCxSR, mask);
649 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
650 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
651 		/* Only clear the status bits we want to clear */
652 		serial_port_out(port, SCxSR,
653 				serial_port_in(port, SCxSR) & mask);
654 	} else {
655 		/* Store the mask, clear parity/framing errors */
656 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
657 	}
658 }
659 
660 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
661     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
662 
663 #ifdef CONFIG_CONSOLE_POLL
664 static int sci_poll_get_char(struct uart_port *port)
665 {
666 	unsigned short status;
667 	int c;
668 
669 	do {
670 		status = serial_port_in(port, SCxSR);
671 		if (status & SCxSR_ERRORS(port)) {
672 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
673 			continue;
674 		}
675 		break;
676 	} while (1);
677 
678 	if (!(status & SCxSR_RDxF(port)))
679 		return NO_POLL_CHAR;
680 
681 	c = serial_port_in(port, SCxRDR);
682 
683 	/* Dummy read */
684 	serial_port_in(port, SCxSR);
685 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
686 
687 	return c;
688 }
689 #endif
690 
691 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
692 {
693 	unsigned short status;
694 
695 	do {
696 		status = serial_port_in(port, SCxSR);
697 	} while (!(status & SCxSR_TDxE(port)));
698 
699 	serial_port_out(port, SCxTDR, c);
700 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
701 }
702 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
703 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
704 
705 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
706 {
707 	struct sci_port *s = to_sci_port(port);
708 
709 	/*
710 	 * Use port-specific handler if provided.
711 	 */
712 	if (s->cfg->ops && s->cfg->ops->init_pins) {
713 		s->cfg->ops->init_pins(port, cflag);
714 		return;
715 	}
716 
717 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
718 		u16 data = serial_port_in(port, SCPDR);
719 		u16 ctrl = serial_port_in(port, SCPCR);
720 
721 		/* Enable RXD and TXD pin functions */
722 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
723 		if (to_sci_port(port)->has_rtscts) {
724 			/* RTS# is output, active low, unless autorts */
725 			if (!(port->mctrl & TIOCM_RTS)) {
726 				ctrl |= SCPCR_RTSC;
727 				data |= SCPDR_RTSD;
728 			} else if (!s->autorts) {
729 				ctrl |= SCPCR_RTSC;
730 				data &= ~SCPDR_RTSD;
731 			} else {
732 				/* Enable RTS# pin function */
733 				ctrl &= ~SCPCR_RTSC;
734 			}
735 			/* Enable CTS# pin function */
736 			ctrl &= ~SCPCR_CTSC;
737 		}
738 		serial_port_out(port, SCPDR, data);
739 		serial_port_out(port, SCPCR, ctrl);
740 	} else if (sci_getreg(port, SCSPTR)->size) {
741 		u16 status = serial_port_in(port, SCSPTR);
742 
743 		/* RTS# is always output; and active low, unless autorts */
744 		status |= SCSPTR_RTSIO;
745 		if (!(port->mctrl & TIOCM_RTS))
746 			status |= SCSPTR_RTSDT;
747 		else if (!s->autorts)
748 			status &= ~SCSPTR_RTSDT;
749 		/* CTS# and SCK are inputs */
750 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
751 		serial_port_out(port, SCSPTR, status);
752 	}
753 }
754 
755 static int sci_txfill(struct uart_port *port)
756 {
757 	struct sci_port *s = to_sci_port(port);
758 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
759 	const struct plat_sci_reg *reg;
760 
761 	reg = sci_getreg(port, SCTFDR);
762 	if (reg->size)
763 		return serial_port_in(port, SCTFDR) & fifo_mask;
764 
765 	reg = sci_getreg(port, SCFDR);
766 	if (reg->size)
767 		return serial_port_in(port, SCFDR) >> 8;
768 
769 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
770 }
771 
772 static int sci_txroom(struct uart_port *port)
773 {
774 	return port->fifosize - sci_txfill(port);
775 }
776 
777 static int sci_rxfill(struct uart_port *port)
778 {
779 	struct sci_port *s = to_sci_port(port);
780 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
781 	const struct plat_sci_reg *reg;
782 
783 	reg = sci_getreg(port, SCRFDR);
784 	if (reg->size)
785 		return serial_port_in(port, SCRFDR) & fifo_mask;
786 
787 	reg = sci_getreg(port, SCFDR);
788 	if (reg->size)
789 		return serial_port_in(port, SCFDR) & fifo_mask;
790 
791 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
792 }
793 
794 /* ********************************************************************** *
795  *                   the interrupt related routines                       *
796  * ********************************************************************** */
797 
798 static void sci_transmit_chars(struct uart_port *port)
799 {
800 	struct circ_buf *xmit = &port->state->xmit;
801 	unsigned int stopped = uart_tx_stopped(port);
802 	unsigned short status;
803 	unsigned short ctrl;
804 	int count;
805 
806 	status = serial_port_in(port, SCxSR);
807 	if (!(status & SCxSR_TDxE(port))) {
808 		ctrl = serial_port_in(port, SCSCR);
809 		if (uart_circ_empty(xmit))
810 			ctrl &= ~SCSCR_TIE;
811 		else
812 			ctrl |= SCSCR_TIE;
813 		serial_port_out(port, SCSCR, ctrl);
814 		return;
815 	}
816 
817 	count = sci_txroom(port);
818 
819 	do {
820 		unsigned char c;
821 
822 		if (port->x_char) {
823 			c = port->x_char;
824 			port->x_char = 0;
825 		} else if (!uart_circ_empty(xmit) && !stopped) {
826 			c = xmit->buf[xmit->tail];
827 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
828 		} else {
829 			break;
830 		}
831 
832 		serial_port_out(port, SCxTDR, c);
833 
834 		port->icount.tx++;
835 	} while (--count > 0);
836 
837 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
838 
839 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
840 		uart_write_wakeup(port);
841 	if (uart_circ_empty(xmit))
842 		sci_stop_tx(port);
843 
844 }
845 
846 /* On SH3, SCIF may read end-of-break as a space->mark char */
847 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
848 
849 static void sci_receive_chars(struct uart_port *port)
850 {
851 	struct tty_port *tport = &port->state->port;
852 	int i, count, copied = 0;
853 	unsigned short status;
854 	unsigned char flag;
855 
856 	status = serial_port_in(port, SCxSR);
857 	if (!(status & SCxSR_RDxF(port)))
858 		return;
859 
860 	while (1) {
861 		/* Don't copy more bytes than there is room for in the buffer */
862 		count = tty_buffer_request_room(tport, sci_rxfill(port));
863 
864 		/* If for any reason we can't copy more data, we're done! */
865 		if (count == 0)
866 			break;
867 
868 		if (port->type == PORT_SCI) {
869 			char c = serial_port_in(port, SCxRDR);
870 			if (uart_handle_sysrq_char(port, c))
871 				count = 0;
872 			else
873 				tty_insert_flip_char(tport, c, TTY_NORMAL);
874 		} else {
875 			for (i = 0; i < count; i++) {
876 				char c = serial_port_in(port, SCxRDR);
877 
878 				status = serial_port_in(port, SCxSR);
879 				if (uart_handle_sysrq_char(port, c)) {
880 					count--; i--;
881 					continue;
882 				}
883 
884 				/* Store data and status */
885 				if (status & SCxSR_FER(port)) {
886 					flag = TTY_FRAME;
887 					port->icount.frame++;
888 					dev_notice(port->dev, "frame error\n");
889 				} else if (status & SCxSR_PER(port)) {
890 					flag = TTY_PARITY;
891 					port->icount.parity++;
892 					dev_notice(port->dev, "parity error\n");
893 				} else
894 					flag = TTY_NORMAL;
895 
896 				tty_insert_flip_char(tport, c, flag);
897 			}
898 		}
899 
900 		serial_port_in(port, SCxSR); /* dummy read */
901 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
902 
903 		copied += count;
904 		port->icount.rx += count;
905 	}
906 
907 	if (copied) {
908 		/* Tell the rest of the system the news. New characters! */
909 		tty_flip_buffer_push(tport);
910 	} else {
911 		/* TTY buffers full; read from RX reg to prevent lockup */
912 		serial_port_in(port, SCxRDR);
913 		serial_port_in(port, SCxSR); /* dummy read */
914 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
915 	}
916 }
917 
918 static int sci_handle_errors(struct uart_port *port)
919 {
920 	int copied = 0;
921 	unsigned short status = serial_port_in(port, SCxSR);
922 	struct tty_port *tport = &port->state->port;
923 	struct sci_port *s = to_sci_port(port);
924 
925 	/* Handle overruns */
926 	if (status & s->params->overrun_mask) {
927 		port->icount.overrun++;
928 
929 		/* overrun error */
930 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
931 			copied++;
932 
933 		dev_notice(port->dev, "overrun error\n");
934 	}
935 
936 	if (status & SCxSR_FER(port)) {
937 		/* frame error */
938 		port->icount.frame++;
939 
940 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
941 			copied++;
942 
943 		dev_notice(port->dev, "frame error\n");
944 	}
945 
946 	if (status & SCxSR_PER(port)) {
947 		/* parity error */
948 		port->icount.parity++;
949 
950 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
951 			copied++;
952 
953 		dev_notice(port->dev, "parity error\n");
954 	}
955 
956 	if (copied)
957 		tty_flip_buffer_push(tport);
958 
959 	return copied;
960 }
961 
962 static int sci_handle_fifo_overrun(struct uart_port *port)
963 {
964 	struct tty_port *tport = &port->state->port;
965 	struct sci_port *s = to_sci_port(port);
966 	const struct plat_sci_reg *reg;
967 	int copied = 0;
968 	u16 status;
969 
970 	reg = sci_getreg(port, s->params->overrun_reg);
971 	if (!reg->size)
972 		return 0;
973 
974 	status = serial_port_in(port, s->params->overrun_reg);
975 	if (status & s->params->overrun_mask) {
976 		status &= ~s->params->overrun_mask;
977 		serial_port_out(port, s->params->overrun_reg, status);
978 
979 		port->icount.overrun++;
980 
981 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
982 		tty_flip_buffer_push(tport);
983 
984 		dev_dbg(port->dev, "overrun error\n");
985 		copied++;
986 	}
987 
988 	return copied;
989 }
990 
991 static int sci_handle_breaks(struct uart_port *port)
992 {
993 	int copied = 0;
994 	unsigned short status = serial_port_in(port, SCxSR);
995 	struct tty_port *tport = &port->state->port;
996 
997 	if (uart_handle_break(port))
998 		return 0;
999 
1000 	if (status & SCxSR_BRK(port)) {
1001 		port->icount.brk++;
1002 
1003 		/* Notify of BREAK */
1004 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1005 			copied++;
1006 
1007 		dev_dbg(port->dev, "BREAK detected\n");
1008 	}
1009 
1010 	if (copied)
1011 		tty_flip_buffer_push(tport);
1012 
1013 	copied += sci_handle_fifo_overrun(port);
1014 
1015 	return copied;
1016 }
1017 
1018 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1019 {
1020 	unsigned int bits;
1021 
1022 	if (rx_trig < 1)
1023 		rx_trig = 1;
1024 	if (rx_trig >= port->fifosize)
1025 		rx_trig = port->fifosize;
1026 
1027 	/* HSCIF can be set to an arbitrary level. */
1028 	if (sci_getreg(port, HSRTRGR)->size) {
1029 		serial_port_out(port, HSRTRGR, rx_trig);
1030 		return rx_trig;
1031 	}
1032 
1033 	switch (port->type) {
1034 	case PORT_SCIF:
1035 		if (rx_trig < 4) {
1036 			bits = 0;
1037 			rx_trig = 1;
1038 		} else if (rx_trig < 8) {
1039 			bits = SCFCR_RTRG0;
1040 			rx_trig = 4;
1041 		} else if (rx_trig < 14) {
1042 			bits = SCFCR_RTRG1;
1043 			rx_trig = 8;
1044 		} else {
1045 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1046 			rx_trig = 14;
1047 		}
1048 		break;
1049 	case PORT_SCIFA:
1050 	case PORT_SCIFB:
1051 		if (rx_trig < 16) {
1052 			bits = 0;
1053 			rx_trig = 1;
1054 		} else if (rx_trig < 32) {
1055 			bits = SCFCR_RTRG0;
1056 			rx_trig = 16;
1057 		} else if (rx_trig < 48) {
1058 			bits = SCFCR_RTRG1;
1059 			rx_trig = 32;
1060 		} else {
1061 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1062 			rx_trig = 48;
1063 		}
1064 		break;
1065 	default:
1066 		WARN(1, "unknown FIFO configuration");
1067 		return 1;
1068 	}
1069 
1070 	serial_port_out(port, SCFCR,
1071 		(serial_port_in(port, SCFCR) &
1072 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1073 
1074 	return rx_trig;
1075 }
1076 
1077 static int scif_rtrg_enabled(struct uart_port *port)
1078 {
1079 	if (sci_getreg(port, HSRTRGR)->size)
1080 		return serial_port_in(port, HSRTRGR) != 0;
1081 	else
1082 		return (serial_port_in(port, SCFCR) &
1083 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1084 }
1085 
1086 static void rx_fifo_timer_fn(struct timer_list *t)
1087 {
1088 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1089 	struct uart_port *port = &s->port;
1090 
1091 	dev_dbg(port->dev, "Rx timed out\n");
1092 	scif_set_rtrg(port, 1);
1093 }
1094 
1095 static ssize_t rx_trigger_show(struct device *dev,
1096 			       struct device_attribute *attr,
1097 			       char *buf)
1098 {
1099 	struct uart_port *port = dev_get_drvdata(dev);
1100 	struct sci_port *sci = to_sci_port(port);
1101 
1102 	return sprintf(buf, "%d\n", sci->rx_trigger);
1103 }
1104 
1105 static ssize_t rx_trigger_store(struct device *dev,
1106 				struct device_attribute *attr,
1107 				const char *buf,
1108 				size_t count)
1109 {
1110 	struct uart_port *port = dev_get_drvdata(dev);
1111 	struct sci_port *sci = to_sci_port(port);
1112 	int ret;
1113 	long r;
1114 
1115 	ret = kstrtol(buf, 0, &r);
1116 	if (ret)
1117 		return ret;
1118 
1119 	sci->rx_trigger = scif_set_rtrg(port, r);
1120 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1121 		scif_set_rtrg(port, 1);
1122 
1123 	return count;
1124 }
1125 
1126 static DEVICE_ATTR(rx_fifo_trigger, 0644, rx_trigger_show, rx_trigger_store);
1127 
1128 static ssize_t rx_fifo_timeout_show(struct device *dev,
1129 			       struct device_attribute *attr,
1130 			       char *buf)
1131 {
1132 	struct uart_port *port = dev_get_drvdata(dev);
1133 	struct sci_port *sci = to_sci_port(port);
1134 	int v;
1135 
1136 	if (port->type == PORT_HSCIF)
1137 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1138 	else
1139 		v = sci->rx_fifo_timeout;
1140 
1141 	return sprintf(buf, "%d\n", v);
1142 }
1143 
1144 static ssize_t rx_fifo_timeout_store(struct device *dev,
1145 				struct device_attribute *attr,
1146 				const char *buf,
1147 				size_t count)
1148 {
1149 	struct uart_port *port = dev_get_drvdata(dev);
1150 	struct sci_port *sci = to_sci_port(port);
1151 	int ret;
1152 	long r;
1153 
1154 	ret = kstrtol(buf, 0, &r);
1155 	if (ret)
1156 		return ret;
1157 
1158 	if (port->type == PORT_HSCIF) {
1159 		if (r < 0 || r > 3)
1160 			return -EINVAL;
1161 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1162 	} else {
1163 		sci->rx_fifo_timeout = r;
1164 		scif_set_rtrg(port, 1);
1165 		if (r > 0)
1166 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1167 	}
1168 
1169 	return count;
1170 }
1171 
1172 static DEVICE_ATTR_RW(rx_fifo_timeout);
1173 
1174 
1175 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1176 static void sci_dma_tx_complete(void *arg)
1177 {
1178 	struct sci_port *s = arg;
1179 	struct uart_port *port = &s->port;
1180 	struct circ_buf *xmit = &port->state->xmit;
1181 	unsigned long flags;
1182 
1183 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1184 
1185 	spin_lock_irqsave(&port->lock, flags);
1186 
1187 	xmit->tail += s->tx_dma_len;
1188 	xmit->tail &= UART_XMIT_SIZE - 1;
1189 
1190 	port->icount.tx += s->tx_dma_len;
1191 
1192 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1193 		uart_write_wakeup(port);
1194 
1195 	if (!uart_circ_empty(xmit)) {
1196 		s->cookie_tx = 0;
1197 		schedule_work(&s->work_tx);
1198 	} else {
1199 		s->cookie_tx = -EINVAL;
1200 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1201 			u16 ctrl = serial_port_in(port, SCSCR);
1202 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1203 		}
1204 	}
1205 
1206 	spin_unlock_irqrestore(&port->lock, flags);
1207 }
1208 
1209 /* Locking: called with port lock held */
1210 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1211 {
1212 	struct uart_port *port = &s->port;
1213 	struct tty_port *tport = &port->state->port;
1214 	int copied;
1215 
1216 	copied = tty_insert_flip_string(tport, buf, count);
1217 	if (copied < count)
1218 		port->icount.buf_overrun++;
1219 
1220 	port->icount.rx += copied;
1221 
1222 	return copied;
1223 }
1224 
1225 static int sci_dma_rx_find_active(struct sci_port *s)
1226 {
1227 	unsigned int i;
1228 
1229 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1230 		if (s->active_rx == s->cookie_rx[i])
1231 			return i;
1232 
1233 	return -1;
1234 }
1235 
1236 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1237 {
1238 	unsigned int i;
1239 
1240 	s->chan_rx = NULL;
1241 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1242 		s->cookie_rx[i] = -EINVAL;
1243 	s->active_rx = 0;
1244 }
1245 
1246 static void sci_dma_rx_release(struct sci_port *s)
1247 {
1248 	struct dma_chan *chan = s->chan_rx_saved;
1249 
1250 	s->chan_rx_saved = NULL;
1251 	sci_dma_rx_chan_invalidate(s);
1252 	dmaengine_terminate_sync(chan);
1253 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1254 			  sg_dma_address(&s->sg_rx[0]));
1255 	dma_release_channel(chan);
1256 }
1257 
1258 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1259 {
1260 	long sec = usec / 1000000;
1261 	long nsec = (usec % 1000000) * 1000;
1262 	ktime_t t = ktime_set(sec, nsec);
1263 
1264 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1265 }
1266 
1267 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1268 {
1269 	struct uart_port *port = &s->port;
1270 	u16 scr;
1271 
1272 	/* Direct new serial port interrupts back to CPU */
1273 	scr = serial_port_in(port, SCSCR);
1274 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1275 		scr &= ~SCSCR_RDRQE;
1276 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1277 	}
1278 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1279 }
1280 
1281 static void sci_dma_rx_complete(void *arg)
1282 {
1283 	struct sci_port *s = arg;
1284 	struct dma_chan *chan = s->chan_rx;
1285 	struct uart_port *port = &s->port;
1286 	struct dma_async_tx_descriptor *desc;
1287 	unsigned long flags;
1288 	int active, count = 0;
1289 
1290 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1291 		s->active_rx);
1292 
1293 	spin_lock_irqsave(&port->lock, flags);
1294 
1295 	active = sci_dma_rx_find_active(s);
1296 	if (active >= 0)
1297 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1298 
1299 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1300 
1301 	if (count)
1302 		tty_flip_buffer_push(&port->state->port);
1303 
1304 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1305 				       DMA_DEV_TO_MEM,
1306 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1307 	if (!desc)
1308 		goto fail;
1309 
1310 	desc->callback = sci_dma_rx_complete;
1311 	desc->callback_param = s;
1312 	s->cookie_rx[active] = dmaengine_submit(desc);
1313 	if (dma_submit_error(s->cookie_rx[active]))
1314 		goto fail;
1315 
1316 	s->active_rx = s->cookie_rx[!active];
1317 
1318 	dma_async_issue_pending(chan);
1319 
1320 	spin_unlock_irqrestore(&port->lock, flags);
1321 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1322 		__func__, s->cookie_rx[active], active, s->active_rx);
1323 	return;
1324 
1325 fail:
1326 	spin_unlock_irqrestore(&port->lock, flags);
1327 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1328 	/* Switch to PIO */
1329 	spin_lock_irqsave(&port->lock, flags);
1330 	dmaengine_terminate_async(chan);
1331 	sci_dma_rx_chan_invalidate(s);
1332 	sci_dma_rx_reenable_irq(s);
1333 	spin_unlock_irqrestore(&port->lock, flags);
1334 }
1335 
1336 static void sci_dma_tx_release(struct sci_port *s)
1337 {
1338 	struct dma_chan *chan = s->chan_tx_saved;
1339 
1340 	cancel_work_sync(&s->work_tx);
1341 	s->chan_tx_saved = s->chan_tx = NULL;
1342 	s->cookie_tx = -EINVAL;
1343 	dmaengine_terminate_sync(chan);
1344 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1345 			 DMA_TO_DEVICE);
1346 	dma_release_channel(chan);
1347 }
1348 
1349 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1350 {
1351 	struct dma_chan *chan = s->chan_rx;
1352 	struct uart_port *port = &s->port;
1353 	unsigned long flags;
1354 	int i;
1355 
1356 	for (i = 0; i < 2; i++) {
1357 		struct scatterlist *sg = &s->sg_rx[i];
1358 		struct dma_async_tx_descriptor *desc;
1359 
1360 		desc = dmaengine_prep_slave_sg(chan,
1361 			sg, 1, DMA_DEV_TO_MEM,
1362 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1363 		if (!desc)
1364 			goto fail;
1365 
1366 		desc->callback = sci_dma_rx_complete;
1367 		desc->callback_param = s;
1368 		s->cookie_rx[i] = dmaengine_submit(desc);
1369 		if (dma_submit_error(s->cookie_rx[i]))
1370 			goto fail;
1371 
1372 	}
1373 
1374 	s->active_rx = s->cookie_rx[0];
1375 
1376 	dma_async_issue_pending(chan);
1377 	return 0;
1378 
1379 fail:
1380 	/* Switch to PIO */
1381 	if (!port_lock_held)
1382 		spin_lock_irqsave(&port->lock, flags);
1383 	if (i)
1384 		dmaengine_terminate_async(chan);
1385 	sci_dma_rx_chan_invalidate(s);
1386 	sci_start_rx(port);
1387 	if (!port_lock_held)
1388 		spin_unlock_irqrestore(&port->lock, flags);
1389 	return -EAGAIN;
1390 }
1391 
1392 static void sci_dma_tx_work_fn(struct work_struct *work)
1393 {
1394 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1395 	struct dma_async_tx_descriptor *desc;
1396 	struct dma_chan *chan = s->chan_tx;
1397 	struct uart_port *port = &s->port;
1398 	struct circ_buf *xmit = &port->state->xmit;
1399 	unsigned long flags;
1400 	dma_addr_t buf;
1401 	int head, tail;
1402 
1403 	/*
1404 	 * DMA is idle now.
1405 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1406 	 * offsets and lengths. Since it is a circular buffer, we have to
1407 	 * transmit till the end, and then the rest. Take the port lock to get a
1408 	 * consistent xmit buffer state.
1409 	 */
1410 	spin_lock_irq(&port->lock);
1411 	head = xmit->head;
1412 	tail = xmit->tail;
1413 	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1414 	s->tx_dma_len = min_t(unsigned int,
1415 		CIRC_CNT(head, tail, UART_XMIT_SIZE),
1416 		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1417 	if (!s->tx_dma_len) {
1418 		/* Transmit buffer has been flushed */
1419 		spin_unlock_irq(&port->lock);
1420 		return;
1421 	}
1422 
1423 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1424 					   DMA_MEM_TO_DEV,
1425 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1426 	if (!desc) {
1427 		spin_unlock_irq(&port->lock);
1428 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1429 		goto switch_to_pio;
1430 	}
1431 
1432 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1433 				   DMA_TO_DEVICE);
1434 
1435 	desc->callback = sci_dma_tx_complete;
1436 	desc->callback_param = s;
1437 	s->cookie_tx = dmaengine_submit(desc);
1438 	if (dma_submit_error(s->cookie_tx)) {
1439 		spin_unlock_irq(&port->lock);
1440 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1441 		goto switch_to_pio;
1442 	}
1443 
1444 	spin_unlock_irq(&port->lock);
1445 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1446 		__func__, xmit->buf, tail, head, s->cookie_tx);
1447 
1448 	dma_async_issue_pending(chan);
1449 	return;
1450 
1451 switch_to_pio:
1452 	spin_lock_irqsave(&port->lock, flags);
1453 	s->chan_tx = NULL;
1454 	sci_start_tx(port);
1455 	spin_unlock_irqrestore(&port->lock, flags);
1456 	return;
1457 }
1458 
1459 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1460 {
1461 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1462 	struct dma_chan *chan = s->chan_rx;
1463 	struct uart_port *port = &s->port;
1464 	struct dma_tx_state state;
1465 	enum dma_status status;
1466 	unsigned long flags;
1467 	unsigned int read;
1468 	int active, count;
1469 
1470 	dev_dbg(port->dev, "DMA Rx timed out\n");
1471 
1472 	spin_lock_irqsave(&port->lock, flags);
1473 
1474 	active = sci_dma_rx_find_active(s);
1475 	if (active < 0) {
1476 		spin_unlock_irqrestore(&port->lock, flags);
1477 		return HRTIMER_NORESTART;
1478 	}
1479 
1480 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1481 	if (status == DMA_COMPLETE) {
1482 		spin_unlock_irqrestore(&port->lock, flags);
1483 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1484 			s->active_rx, active);
1485 
1486 		/* Let packet complete handler take care of the packet */
1487 		return HRTIMER_NORESTART;
1488 	}
1489 
1490 	dmaengine_pause(chan);
1491 
1492 	/*
1493 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1494 	 * data keeps on coming until transaction is complete so check
1495 	 * for DMA_COMPLETE again
1496 	 * Let packet complete handler take care of the packet
1497 	 */
1498 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1499 	if (status == DMA_COMPLETE) {
1500 		spin_unlock_irqrestore(&port->lock, flags);
1501 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1502 		return HRTIMER_NORESTART;
1503 	}
1504 
1505 	/* Handle incomplete DMA receive */
1506 	dmaengine_terminate_async(s->chan_rx);
1507 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1508 
1509 	if (read) {
1510 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1511 		if (count)
1512 			tty_flip_buffer_push(&port->state->port);
1513 	}
1514 
1515 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1516 		sci_dma_rx_submit(s, true);
1517 
1518 	sci_dma_rx_reenable_irq(s);
1519 
1520 	spin_unlock_irqrestore(&port->lock, flags);
1521 
1522 	return HRTIMER_NORESTART;
1523 }
1524 
1525 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1526 					     enum dma_transfer_direction dir)
1527 {
1528 	struct dma_chan *chan;
1529 	struct dma_slave_config cfg;
1530 	int ret;
1531 
1532 	chan = dma_request_slave_channel(port->dev,
1533 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1534 	if (!chan) {
1535 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1536 		return NULL;
1537 	}
1538 
1539 	memset(&cfg, 0, sizeof(cfg));
1540 	cfg.direction = dir;
1541 	if (dir == DMA_MEM_TO_DEV) {
1542 		cfg.dst_addr = port->mapbase +
1543 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1544 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1545 	} else {
1546 		cfg.src_addr = port->mapbase +
1547 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1548 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1549 	}
1550 
1551 	ret = dmaengine_slave_config(chan, &cfg);
1552 	if (ret) {
1553 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1554 		dma_release_channel(chan);
1555 		return NULL;
1556 	}
1557 
1558 	return chan;
1559 }
1560 
1561 static void sci_request_dma(struct uart_port *port)
1562 {
1563 	struct sci_port *s = to_sci_port(port);
1564 	struct dma_chan *chan;
1565 
1566 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1567 
1568 	/*
1569 	 * DMA on console may interfere with Kernel log messages which use
1570 	 * plain putchar(). So, simply don't use it with a console.
1571 	 */
1572 	if (uart_console(port))
1573 		return;
1574 
1575 	if (!port->dev->of_node)
1576 		return;
1577 
1578 	s->cookie_tx = -EINVAL;
1579 
1580 	/*
1581 	 * Don't request a dma channel if no channel was specified
1582 	 * in the device tree.
1583 	 */
1584 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1585 		return;
1586 
1587 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1588 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1589 	if (chan) {
1590 		/* UART circular tx buffer is an aligned page. */
1591 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1592 						port->state->xmit.buf,
1593 						UART_XMIT_SIZE,
1594 						DMA_TO_DEVICE);
1595 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1596 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1597 			dma_release_channel(chan);
1598 		} else {
1599 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1600 				__func__, UART_XMIT_SIZE,
1601 				port->state->xmit.buf, &s->tx_dma_addr);
1602 
1603 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1604 			s->chan_tx_saved = s->chan_tx = chan;
1605 		}
1606 	}
1607 
1608 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1609 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1610 	if (chan) {
1611 		unsigned int i;
1612 		dma_addr_t dma;
1613 		void *buf;
1614 
1615 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1616 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1617 					 &dma, GFP_KERNEL);
1618 		if (!buf) {
1619 			dev_warn(port->dev,
1620 				 "Failed to allocate Rx dma buffer, using PIO\n");
1621 			dma_release_channel(chan);
1622 			return;
1623 		}
1624 
1625 		for (i = 0; i < 2; i++) {
1626 			struct scatterlist *sg = &s->sg_rx[i];
1627 
1628 			sg_init_table(sg, 1);
1629 			s->rx_buf[i] = buf;
1630 			sg_dma_address(sg) = dma;
1631 			sg_dma_len(sg) = s->buf_len_rx;
1632 
1633 			buf += s->buf_len_rx;
1634 			dma += s->buf_len_rx;
1635 		}
1636 
1637 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1638 		s->rx_timer.function = sci_dma_rx_timer_fn;
1639 
1640 		s->chan_rx_saved = s->chan_rx = chan;
1641 
1642 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1643 			sci_dma_rx_submit(s, false);
1644 	}
1645 }
1646 
1647 static void sci_free_dma(struct uart_port *port)
1648 {
1649 	struct sci_port *s = to_sci_port(port);
1650 
1651 	if (s->chan_tx_saved)
1652 		sci_dma_tx_release(s);
1653 	if (s->chan_rx_saved)
1654 		sci_dma_rx_release(s);
1655 }
1656 
1657 static void sci_flush_buffer(struct uart_port *port)
1658 {
1659 	struct sci_port *s = to_sci_port(port);
1660 
1661 	/*
1662 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1663 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1664 	 * pending transfers
1665 	 */
1666 	s->tx_dma_len = 0;
1667 	if (s->chan_tx) {
1668 		dmaengine_terminate_async(s->chan_tx);
1669 		s->cookie_tx = -EINVAL;
1670 	}
1671 }
1672 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1673 static inline void sci_request_dma(struct uart_port *port)
1674 {
1675 }
1676 
1677 static inline void sci_free_dma(struct uart_port *port)
1678 {
1679 }
1680 
1681 #define sci_flush_buffer	NULL
1682 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1683 
1684 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1685 {
1686 	struct uart_port *port = ptr;
1687 	struct sci_port *s = to_sci_port(port);
1688 
1689 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1690 	if (s->chan_rx) {
1691 		u16 scr = serial_port_in(port, SCSCR);
1692 		u16 ssr = serial_port_in(port, SCxSR);
1693 
1694 		/* Disable future Rx interrupts */
1695 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1696 			disable_irq_nosync(irq);
1697 			scr |= SCSCR_RDRQE;
1698 		} else {
1699 			if (sci_dma_rx_submit(s, false) < 0)
1700 				goto handle_pio;
1701 
1702 			scr &= ~SCSCR_RIE;
1703 		}
1704 		serial_port_out(port, SCSCR, scr);
1705 		/* Clear current interrupt */
1706 		serial_port_out(port, SCxSR,
1707 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1708 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1709 			jiffies, s->rx_timeout);
1710 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1711 
1712 		return IRQ_HANDLED;
1713 	}
1714 
1715 handle_pio:
1716 #endif
1717 
1718 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1719 		if (!scif_rtrg_enabled(port))
1720 			scif_set_rtrg(port, s->rx_trigger);
1721 
1722 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1723 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1724 	}
1725 
1726 	/* I think sci_receive_chars has to be called irrespective
1727 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1728 	 * to be disabled?
1729 	 */
1730 	sci_receive_chars(port);
1731 
1732 	return IRQ_HANDLED;
1733 }
1734 
1735 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1736 {
1737 	struct uart_port *port = ptr;
1738 	unsigned long flags;
1739 
1740 	spin_lock_irqsave(&port->lock, flags);
1741 	sci_transmit_chars(port);
1742 	spin_unlock_irqrestore(&port->lock, flags);
1743 
1744 	return IRQ_HANDLED;
1745 }
1746 
1747 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1748 {
1749 	struct uart_port *port = ptr;
1750 
1751 	/* Handle BREAKs */
1752 	sci_handle_breaks(port);
1753 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1754 
1755 	return IRQ_HANDLED;
1756 }
1757 
1758 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1759 {
1760 	struct uart_port *port = ptr;
1761 	struct sci_port *s = to_sci_port(port);
1762 
1763 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1764 		/* Break and Error interrupts are muxed */
1765 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1766 
1767 		/* Break Interrupt */
1768 		if (ssr_status & SCxSR_BRK(port))
1769 			sci_br_interrupt(irq, ptr);
1770 
1771 		/* Break only? */
1772 		if (!(ssr_status & SCxSR_ERRORS(port)))
1773 			return IRQ_HANDLED;
1774 	}
1775 
1776 	/* Handle errors */
1777 	if (port->type == PORT_SCI) {
1778 		if (sci_handle_errors(port)) {
1779 			/* discard character in rx buffer */
1780 			serial_port_in(port, SCxSR);
1781 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1782 		}
1783 	} else {
1784 		sci_handle_fifo_overrun(port);
1785 		if (!s->chan_rx)
1786 			sci_receive_chars(port);
1787 	}
1788 
1789 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1790 
1791 	/* Kick the transmission */
1792 	if (!s->chan_tx)
1793 		sci_tx_interrupt(irq, ptr);
1794 
1795 	return IRQ_HANDLED;
1796 }
1797 
1798 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1799 {
1800 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1801 	struct uart_port *port = ptr;
1802 	struct sci_port *s = to_sci_port(port);
1803 	irqreturn_t ret = IRQ_NONE;
1804 
1805 	ssr_status = serial_port_in(port, SCxSR);
1806 	scr_status = serial_port_in(port, SCSCR);
1807 	if (s->params->overrun_reg == SCxSR)
1808 		orer_status = ssr_status;
1809 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1810 		orer_status = serial_port_in(port, s->params->overrun_reg);
1811 
1812 	err_enabled = scr_status & port_rx_irq_mask(port);
1813 
1814 	/* Tx Interrupt */
1815 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1816 	    !s->chan_tx)
1817 		ret = sci_tx_interrupt(irq, ptr);
1818 
1819 	/*
1820 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1821 	 * DR flags
1822 	 */
1823 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1824 	    (scr_status & SCSCR_RIE))
1825 		ret = sci_rx_interrupt(irq, ptr);
1826 
1827 	/* Error Interrupt */
1828 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1829 		ret = sci_er_interrupt(irq, ptr);
1830 
1831 	/* Break Interrupt */
1832 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1833 		ret = sci_br_interrupt(irq, ptr);
1834 
1835 	/* Overrun Interrupt */
1836 	if (orer_status & s->params->overrun_mask) {
1837 		sci_handle_fifo_overrun(port);
1838 		ret = IRQ_HANDLED;
1839 	}
1840 
1841 	return ret;
1842 }
1843 
1844 static const struct sci_irq_desc {
1845 	const char	*desc;
1846 	irq_handler_t	handler;
1847 } sci_irq_desc[] = {
1848 	/*
1849 	 * Split out handlers, the default case.
1850 	 */
1851 	[SCIx_ERI_IRQ] = {
1852 		.desc = "rx err",
1853 		.handler = sci_er_interrupt,
1854 	},
1855 
1856 	[SCIx_RXI_IRQ] = {
1857 		.desc = "rx full",
1858 		.handler = sci_rx_interrupt,
1859 	},
1860 
1861 	[SCIx_TXI_IRQ] = {
1862 		.desc = "tx empty",
1863 		.handler = sci_tx_interrupt,
1864 	},
1865 
1866 	[SCIx_BRI_IRQ] = {
1867 		.desc = "break",
1868 		.handler = sci_br_interrupt,
1869 	},
1870 
1871 	[SCIx_DRI_IRQ] = {
1872 		.desc = "rx ready",
1873 		.handler = sci_rx_interrupt,
1874 	},
1875 
1876 	[SCIx_TEI_IRQ] = {
1877 		.desc = "tx end",
1878 		.handler = sci_tx_interrupt,
1879 	},
1880 
1881 	/*
1882 	 * Special muxed handler.
1883 	 */
1884 	[SCIx_MUX_IRQ] = {
1885 		.desc = "mux",
1886 		.handler = sci_mpxed_interrupt,
1887 	},
1888 };
1889 
1890 static int sci_request_irq(struct sci_port *port)
1891 {
1892 	struct uart_port *up = &port->port;
1893 	int i, j, w, ret = 0;
1894 
1895 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1896 		const struct sci_irq_desc *desc;
1897 		int irq;
1898 
1899 		/* Check if already registered (muxed) */
1900 		for (w = 0; w < i; w++)
1901 			if (port->irqs[w] == port->irqs[i])
1902 				w = i + 1;
1903 		if (w > i)
1904 			continue;
1905 
1906 		if (SCIx_IRQ_IS_MUXED(port)) {
1907 			i = SCIx_MUX_IRQ;
1908 			irq = up->irq;
1909 		} else {
1910 			irq = port->irqs[i];
1911 
1912 			/*
1913 			 * Certain port types won't support all of the
1914 			 * available interrupt sources.
1915 			 */
1916 			if (unlikely(irq < 0))
1917 				continue;
1918 		}
1919 
1920 		desc = sci_irq_desc + i;
1921 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1922 					    dev_name(up->dev), desc->desc);
1923 		if (!port->irqstr[j]) {
1924 			ret = -ENOMEM;
1925 			goto out_nomem;
1926 		}
1927 
1928 		ret = request_irq(irq, desc->handler, up->irqflags,
1929 				  port->irqstr[j], port);
1930 		if (unlikely(ret)) {
1931 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1932 			goto out_noirq;
1933 		}
1934 	}
1935 
1936 	return 0;
1937 
1938 out_noirq:
1939 	while (--i >= 0)
1940 		free_irq(port->irqs[i], port);
1941 
1942 out_nomem:
1943 	while (--j >= 0)
1944 		kfree(port->irqstr[j]);
1945 
1946 	return ret;
1947 }
1948 
1949 static void sci_free_irq(struct sci_port *port)
1950 {
1951 	int i, j;
1952 
1953 	/*
1954 	 * Intentionally in reverse order so we iterate over the muxed
1955 	 * IRQ first.
1956 	 */
1957 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1958 		int irq = port->irqs[i];
1959 
1960 		/*
1961 		 * Certain port types won't support all of the available
1962 		 * interrupt sources.
1963 		 */
1964 		if (unlikely(irq < 0))
1965 			continue;
1966 
1967 		/* Check if already freed (irq was muxed) */
1968 		for (j = 0; j < i; j++)
1969 			if (port->irqs[j] == irq)
1970 				j = i + 1;
1971 		if (j > i)
1972 			continue;
1973 
1974 		free_irq(port->irqs[i], port);
1975 		kfree(port->irqstr[i]);
1976 
1977 		if (SCIx_IRQ_IS_MUXED(port)) {
1978 			/* If there's only one IRQ, we're done. */
1979 			return;
1980 		}
1981 	}
1982 }
1983 
1984 static unsigned int sci_tx_empty(struct uart_port *port)
1985 {
1986 	unsigned short status = serial_port_in(port, SCxSR);
1987 	unsigned short in_tx_fifo = sci_txfill(port);
1988 
1989 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1990 }
1991 
1992 static void sci_set_rts(struct uart_port *port, bool state)
1993 {
1994 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1995 		u16 data = serial_port_in(port, SCPDR);
1996 
1997 		/* Active low */
1998 		if (state)
1999 			data &= ~SCPDR_RTSD;
2000 		else
2001 			data |= SCPDR_RTSD;
2002 		serial_port_out(port, SCPDR, data);
2003 
2004 		/* RTS# is output */
2005 		serial_port_out(port, SCPCR,
2006 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2007 	} else if (sci_getreg(port, SCSPTR)->size) {
2008 		u16 ctrl = serial_port_in(port, SCSPTR);
2009 
2010 		/* Active low */
2011 		if (state)
2012 			ctrl &= ~SCSPTR_RTSDT;
2013 		else
2014 			ctrl |= SCSPTR_RTSDT;
2015 		serial_port_out(port, SCSPTR, ctrl);
2016 	}
2017 }
2018 
2019 static bool sci_get_cts(struct uart_port *port)
2020 {
2021 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2022 		/* Active low */
2023 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2024 	} else if (sci_getreg(port, SCSPTR)->size) {
2025 		/* Active low */
2026 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2027 	}
2028 
2029 	return true;
2030 }
2031 
2032 /*
2033  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2034  * CTS/RTS is supported in hardware by at least one port and controlled
2035  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2036  * handled via the ->init_pins() op, which is a bit of a one-way street,
2037  * lacking any ability to defer pin control -- this will later be
2038  * converted over to the GPIO framework).
2039  *
2040  * Other modes (such as loopback) are supported generically on certain
2041  * port types, but not others. For these it's sufficient to test for the
2042  * existence of the support register and simply ignore the port type.
2043  */
2044 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2045 {
2046 	struct sci_port *s = to_sci_port(port);
2047 
2048 	if (mctrl & TIOCM_LOOP) {
2049 		const struct plat_sci_reg *reg;
2050 
2051 		/*
2052 		 * Standard loopback mode for SCFCR ports.
2053 		 */
2054 		reg = sci_getreg(port, SCFCR);
2055 		if (reg->size)
2056 			serial_port_out(port, SCFCR,
2057 					serial_port_in(port, SCFCR) |
2058 					SCFCR_LOOP);
2059 	}
2060 
2061 	mctrl_gpio_set(s->gpios, mctrl);
2062 
2063 	if (!s->has_rtscts)
2064 		return;
2065 
2066 	if (!(mctrl & TIOCM_RTS)) {
2067 		/* Disable Auto RTS */
2068 		serial_port_out(port, SCFCR,
2069 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2070 
2071 		/* Clear RTS */
2072 		sci_set_rts(port, 0);
2073 	} else if (s->autorts) {
2074 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2075 			/* Enable RTS# pin function */
2076 			serial_port_out(port, SCPCR,
2077 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2078 		}
2079 
2080 		/* Enable Auto RTS */
2081 		serial_port_out(port, SCFCR,
2082 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2083 	} else {
2084 		/* Set RTS */
2085 		sci_set_rts(port, 1);
2086 	}
2087 }
2088 
2089 static unsigned int sci_get_mctrl(struct uart_port *port)
2090 {
2091 	struct sci_port *s = to_sci_port(port);
2092 	struct mctrl_gpios *gpios = s->gpios;
2093 	unsigned int mctrl = 0;
2094 
2095 	mctrl_gpio_get(gpios, &mctrl);
2096 
2097 	/*
2098 	 * CTS/RTS is handled in hardware when supported, while nothing
2099 	 * else is wired up.
2100 	 */
2101 	if (s->autorts) {
2102 		if (sci_get_cts(port))
2103 			mctrl |= TIOCM_CTS;
2104 	} else if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS))) {
2105 		mctrl |= TIOCM_CTS;
2106 	}
2107 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))
2108 		mctrl |= TIOCM_DSR;
2109 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))
2110 		mctrl |= TIOCM_CAR;
2111 
2112 	return mctrl;
2113 }
2114 
2115 static void sci_enable_ms(struct uart_port *port)
2116 {
2117 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2118 }
2119 
2120 static void sci_break_ctl(struct uart_port *port, int break_state)
2121 {
2122 	unsigned short scscr, scsptr;
2123 	unsigned long flags;
2124 
2125 	/* check wheter the port has SCSPTR */
2126 	if (!sci_getreg(port, SCSPTR)->size) {
2127 		/*
2128 		 * Not supported by hardware. Most parts couple break and rx
2129 		 * interrupts together, with break detection always enabled.
2130 		 */
2131 		return;
2132 	}
2133 
2134 	spin_lock_irqsave(&port->lock, flags);
2135 	scsptr = serial_port_in(port, SCSPTR);
2136 	scscr = serial_port_in(port, SCSCR);
2137 
2138 	if (break_state == -1) {
2139 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2140 		scscr &= ~SCSCR_TE;
2141 	} else {
2142 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2143 		scscr |= SCSCR_TE;
2144 	}
2145 
2146 	serial_port_out(port, SCSPTR, scsptr);
2147 	serial_port_out(port, SCSCR, scscr);
2148 	spin_unlock_irqrestore(&port->lock, flags);
2149 }
2150 
2151 static int sci_startup(struct uart_port *port)
2152 {
2153 	struct sci_port *s = to_sci_port(port);
2154 	int ret;
2155 
2156 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2157 
2158 	sci_request_dma(port);
2159 
2160 	ret = sci_request_irq(s);
2161 	if (unlikely(ret < 0)) {
2162 		sci_free_dma(port);
2163 		return ret;
2164 	}
2165 
2166 	return 0;
2167 }
2168 
2169 static void sci_shutdown(struct uart_port *port)
2170 {
2171 	struct sci_port *s = to_sci_port(port);
2172 	unsigned long flags;
2173 	u16 scr;
2174 
2175 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2176 
2177 	s->autorts = false;
2178 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2179 
2180 	spin_lock_irqsave(&port->lock, flags);
2181 	sci_stop_rx(port);
2182 	sci_stop_tx(port);
2183 	/*
2184 	 * Stop RX and TX, disable related interrupts, keep clock source
2185 	 * and HSCIF TOT bits
2186 	 */
2187 	scr = serial_port_in(port, SCSCR);
2188 	serial_port_out(port, SCSCR, scr &
2189 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2190 	spin_unlock_irqrestore(&port->lock, flags);
2191 
2192 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2193 	if (s->chan_rx_saved) {
2194 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2195 			port->line);
2196 		hrtimer_cancel(&s->rx_timer);
2197 	}
2198 #endif
2199 
2200 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2201 		del_timer_sync(&s->rx_fifo_timer);
2202 	sci_free_irq(s);
2203 	sci_free_dma(port);
2204 }
2205 
2206 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2207 			unsigned int *srr)
2208 {
2209 	unsigned long freq = s->clk_rates[SCI_SCK];
2210 	int err, min_err = INT_MAX;
2211 	unsigned int sr;
2212 
2213 	if (s->port.type != PORT_HSCIF)
2214 		freq *= 2;
2215 
2216 	for_each_sr(sr, s) {
2217 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2218 		if (abs(err) >= abs(min_err))
2219 			continue;
2220 
2221 		min_err = err;
2222 		*srr = sr - 1;
2223 
2224 		if (!err)
2225 			break;
2226 	}
2227 
2228 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2229 		*srr + 1);
2230 	return min_err;
2231 }
2232 
2233 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2234 			unsigned long freq, unsigned int *dlr,
2235 			unsigned int *srr)
2236 {
2237 	int err, min_err = INT_MAX;
2238 	unsigned int sr, dl;
2239 
2240 	if (s->port.type != PORT_HSCIF)
2241 		freq *= 2;
2242 
2243 	for_each_sr(sr, s) {
2244 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2245 		dl = clamp(dl, 1U, 65535U);
2246 
2247 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2248 		if (abs(err) >= abs(min_err))
2249 			continue;
2250 
2251 		min_err = err;
2252 		*dlr = dl;
2253 		*srr = sr - 1;
2254 
2255 		if (!err)
2256 			break;
2257 	}
2258 
2259 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2260 		min_err, *dlr, *srr + 1);
2261 	return min_err;
2262 }
2263 
2264 /* calculate sample rate, BRR, and clock select */
2265 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2266 			  unsigned int *brr, unsigned int *srr,
2267 			  unsigned int *cks)
2268 {
2269 	unsigned long freq = s->clk_rates[SCI_FCK];
2270 	unsigned int sr, br, prediv, scrate, c;
2271 	int err, min_err = INT_MAX;
2272 
2273 	if (s->port.type != PORT_HSCIF)
2274 		freq *= 2;
2275 
2276 	/*
2277 	 * Find the combination of sample rate and clock select with the
2278 	 * smallest deviation from the desired baud rate.
2279 	 * Prefer high sample rates to maximise the receive margin.
2280 	 *
2281 	 * M: Receive margin (%)
2282 	 * N: Ratio of bit rate to clock (N = sampling rate)
2283 	 * D: Clock duty (D = 0 to 1.0)
2284 	 * L: Frame length (L = 9 to 12)
2285 	 * F: Absolute value of clock frequency deviation
2286 	 *
2287 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2288 	 *      (|D - 0.5| / N * (1 + F))|
2289 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2290 	 */
2291 	for_each_sr(sr, s) {
2292 		for (c = 0; c <= 3; c++) {
2293 			/* integerized formulas from HSCIF documentation */
2294 			prediv = sr * (1 << (2 * c + 1));
2295 
2296 			/*
2297 			 * We need to calculate:
2298 			 *
2299 			 *     br = freq / (prediv * bps) clamped to [1..256]
2300 			 *     err = freq / (br * prediv) - bps
2301 			 *
2302 			 * Watch out for overflow when calculating the desired
2303 			 * sampling clock rate!
2304 			 */
2305 			if (bps > UINT_MAX / prediv)
2306 				break;
2307 
2308 			scrate = prediv * bps;
2309 			br = DIV_ROUND_CLOSEST(freq, scrate);
2310 			br = clamp(br, 1U, 256U);
2311 
2312 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2313 			if (abs(err) >= abs(min_err))
2314 				continue;
2315 
2316 			min_err = err;
2317 			*brr = br - 1;
2318 			*srr = sr - 1;
2319 			*cks = c;
2320 
2321 			if (!err)
2322 				goto found;
2323 		}
2324 	}
2325 
2326 found:
2327 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2328 		min_err, *brr, *srr + 1, *cks);
2329 	return min_err;
2330 }
2331 
2332 static void sci_reset(struct uart_port *port)
2333 {
2334 	const struct plat_sci_reg *reg;
2335 	unsigned int status;
2336 	struct sci_port *s = to_sci_port(port);
2337 
2338 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2339 
2340 	reg = sci_getreg(port, SCFCR);
2341 	if (reg->size)
2342 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2343 
2344 	sci_clear_SCxSR(port,
2345 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2346 			SCxSR_BREAK_CLEAR(port));
2347 	if (sci_getreg(port, SCLSR)->size) {
2348 		status = serial_port_in(port, SCLSR);
2349 		status &= ~(SCLSR_TO | SCLSR_ORER);
2350 		serial_port_out(port, SCLSR, status);
2351 	}
2352 
2353 	if (s->rx_trigger > 1) {
2354 		if (s->rx_fifo_timeout) {
2355 			scif_set_rtrg(port, 1);
2356 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2357 		} else {
2358 			if (port->type == PORT_SCIFA ||
2359 			    port->type == PORT_SCIFB)
2360 				scif_set_rtrg(port, 1);
2361 			else
2362 				scif_set_rtrg(port, s->rx_trigger);
2363 		}
2364 	}
2365 }
2366 
2367 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2368 			    struct ktermios *old)
2369 {
2370 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2371 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2372 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2373 	struct sci_port *s = to_sci_port(port);
2374 	const struct plat_sci_reg *reg;
2375 	int min_err = INT_MAX, err;
2376 	unsigned long max_freq = 0;
2377 	int best_clk = -1;
2378 	unsigned long flags;
2379 
2380 	if ((termios->c_cflag & CSIZE) == CS7)
2381 		smr_val |= SCSMR_CHR;
2382 	if (termios->c_cflag & PARENB)
2383 		smr_val |= SCSMR_PE;
2384 	if (termios->c_cflag & PARODD)
2385 		smr_val |= SCSMR_PE | SCSMR_ODD;
2386 	if (termios->c_cflag & CSTOPB)
2387 		smr_val |= SCSMR_STOP;
2388 
2389 	/*
2390 	 * earlyprintk comes here early on with port->uartclk set to zero.
2391 	 * the clock framework is not up and running at this point so here
2392 	 * we assume that 115200 is the maximum baud rate. please note that
2393 	 * the baud rate is not programmed during earlyprintk - it is assumed
2394 	 * that the previous boot loader has enabled required clocks and
2395 	 * setup the baud rate generator hardware for us already.
2396 	 */
2397 	if (!port->uartclk) {
2398 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2399 		goto done;
2400 	}
2401 
2402 	for (i = 0; i < SCI_NUM_CLKS; i++)
2403 		max_freq = max(max_freq, s->clk_rates[i]);
2404 
2405 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2406 	if (!baud)
2407 		goto done;
2408 
2409 	/*
2410 	 * There can be multiple sources for the sampling clock.  Find the one
2411 	 * that gives us the smallest deviation from the desired baud rate.
2412 	 */
2413 
2414 	/* Optional Undivided External Clock */
2415 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2416 	    port->type != PORT_SCIFB) {
2417 		err = sci_sck_calc(s, baud, &srr1);
2418 		if (abs(err) < abs(min_err)) {
2419 			best_clk = SCI_SCK;
2420 			scr_val = SCSCR_CKE1;
2421 			sccks = SCCKS_CKS;
2422 			min_err = err;
2423 			srr = srr1;
2424 			if (!err)
2425 				goto done;
2426 		}
2427 	}
2428 
2429 	/* Optional BRG Frequency Divided External Clock */
2430 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2431 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2432 				   &srr1);
2433 		if (abs(err) < abs(min_err)) {
2434 			best_clk = SCI_SCIF_CLK;
2435 			scr_val = SCSCR_CKE1;
2436 			sccks = 0;
2437 			min_err = err;
2438 			dl = dl1;
2439 			srr = srr1;
2440 			if (!err)
2441 				goto done;
2442 		}
2443 	}
2444 
2445 	/* Optional BRG Frequency Divided Internal Clock */
2446 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2447 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2448 				   &srr1);
2449 		if (abs(err) < abs(min_err)) {
2450 			best_clk = SCI_BRG_INT;
2451 			scr_val = SCSCR_CKE1;
2452 			sccks = SCCKS_XIN;
2453 			min_err = err;
2454 			dl = dl1;
2455 			srr = srr1;
2456 			if (!min_err)
2457 				goto done;
2458 		}
2459 	}
2460 
2461 	/* Divided Functional Clock using standard Bit Rate Register */
2462 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2463 	if (abs(err) < abs(min_err)) {
2464 		best_clk = SCI_FCK;
2465 		scr_val = 0;
2466 		min_err = err;
2467 		brr = brr1;
2468 		srr = srr1;
2469 		cks = cks1;
2470 	}
2471 
2472 done:
2473 	if (best_clk >= 0)
2474 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2475 			s->clks[best_clk], baud, min_err);
2476 
2477 	sci_port_enable(s);
2478 
2479 	/*
2480 	 * Program the optional External Baud Rate Generator (BRG) first.
2481 	 * It controls the mux to select (H)SCK or frequency divided clock.
2482 	 */
2483 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2484 		serial_port_out(port, SCDL, dl);
2485 		serial_port_out(port, SCCKS, sccks);
2486 	}
2487 
2488 	spin_lock_irqsave(&port->lock, flags);
2489 
2490 	sci_reset(port);
2491 
2492 	uart_update_timeout(port, termios->c_cflag, baud);
2493 
2494 	/* byte size and parity */
2495 	switch (termios->c_cflag & CSIZE) {
2496 	case CS5:
2497 		bits = 7;
2498 		break;
2499 	case CS6:
2500 		bits = 8;
2501 		break;
2502 	case CS7:
2503 		bits = 9;
2504 		break;
2505 	default:
2506 		bits = 10;
2507 		break;
2508 	}
2509 
2510 	if (termios->c_cflag & CSTOPB)
2511 		bits++;
2512 	if (termios->c_cflag & PARENB)
2513 		bits++;
2514 
2515 	if (best_clk >= 0) {
2516 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2517 			switch (srr + 1) {
2518 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2519 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2520 			case 11: smr_val |= SCSMR_SRC_11; break;
2521 			case 13: smr_val |= SCSMR_SRC_13; break;
2522 			case 16: smr_val |= SCSMR_SRC_16; break;
2523 			case 17: smr_val |= SCSMR_SRC_17; break;
2524 			case 19: smr_val |= SCSMR_SRC_19; break;
2525 			case 27: smr_val |= SCSMR_SRC_27; break;
2526 			}
2527 		smr_val |= cks;
2528 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2529 		serial_port_out(port, SCSMR, smr_val);
2530 		serial_port_out(port, SCBRR, brr);
2531 		if (sci_getreg(port, HSSRR)->size) {
2532 			unsigned int hssrr = srr | HSCIF_SRE;
2533 			/* Calculate deviation from intended rate at the
2534 			 * center of the last stop bit in sampling clocks.
2535 			 */
2536 			int last_stop = bits * 2 - 1;
2537 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2538 							  (int)(srr + 1),
2539 							  2 * (int)baud);
2540 
2541 			if (abs(deviation) >= 2) {
2542 				/* At least two sampling clocks off at the
2543 				 * last stop bit; we can increase the error
2544 				 * margin by shifting the sampling point.
2545 				 */
2546 				int shift = clamp(deviation / 2, -8, 7);
2547 
2548 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2549 					 HSCIF_SRHP_MASK;
2550 				hssrr |= HSCIF_SRDE;
2551 			}
2552 			serial_port_out(port, HSSRR, hssrr);
2553 		}
2554 
2555 		/* Wait one bit interval */
2556 		udelay((1000000 + (baud - 1)) / baud);
2557 	} else {
2558 		/* Don't touch the bit rate configuration */
2559 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2560 		smr_val |= serial_port_in(port, SCSMR) &
2561 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2562 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2563 		serial_port_out(port, SCSMR, smr_val);
2564 	}
2565 
2566 	sci_init_pins(port, termios->c_cflag);
2567 
2568 	port->status &= ~UPSTAT_AUTOCTS;
2569 	s->autorts = false;
2570 	reg = sci_getreg(port, SCFCR);
2571 	if (reg->size) {
2572 		unsigned short ctrl = serial_port_in(port, SCFCR);
2573 
2574 		if ((port->flags & UPF_HARD_FLOW) &&
2575 		    (termios->c_cflag & CRTSCTS)) {
2576 			/* There is no CTS interrupt to restart the hardware */
2577 			port->status |= UPSTAT_AUTOCTS;
2578 			/* MCE is enabled when RTS is raised */
2579 			s->autorts = true;
2580 		}
2581 
2582 		/*
2583 		 * As we've done a sci_reset() above, ensure we don't
2584 		 * interfere with the FIFOs while toggling MCE. As the
2585 		 * reset values could still be set, simply mask them out.
2586 		 */
2587 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2588 
2589 		serial_port_out(port, SCFCR, ctrl);
2590 	}
2591 	if (port->flags & UPF_HARD_FLOW) {
2592 		/* Refresh (Auto) RTS */
2593 		sci_set_mctrl(port, port->mctrl);
2594 	}
2595 
2596 	scr_val |= SCSCR_RE | SCSCR_TE |
2597 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2598 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2599 	if ((srr + 1 == 5) &&
2600 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2601 		/*
2602 		 * In asynchronous mode, when the sampling rate is 1/5, first
2603 		 * received data may become invalid on some SCIFA and SCIFB.
2604 		 * To avoid this problem wait more than 1 serial data time (1
2605 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2606 		 */
2607 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2608 	}
2609 
2610 	/*
2611 	 * Calculate delay for 2 DMA buffers (4 FIFO).
2612 	 * See serial_core.c::uart_update_timeout().
2613 	 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2614 	 * function calculates 1 jiffie for the data plus 5 jiffies for the
2615 	 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2616 	 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2617 	 * value obtained by this formula is too small. Therefore, if the value
2618 	 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2619 	 */
2620 	s->rx_frame = (10000 * bits) / (baud / 100);
2621 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2622 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2623 	if (s->rx_timeout < 20)
2624 		s->rx_timeout = 20;
2625 #endif
2626 
2627 	if ((termios->c_cflag & CREAD) != 0)
2628 		sci_start_rx(port);
2629 
2630 	spin_unlock_irqrestore(&port->lock, flags);
2631 
2632 	sci_port_disable(s);
2633 
2634 	if (UART_ENABLE_MS(port, termios->c_cflag))
2635 		sci_enable_ms(port);
2636 }
2637 
2638 static void sci_pm(struct uart_port *port, unsigned int state,
2639 		   unsigned int oldstate)
2640 {
2641 	struct sci_port *sci_port = to_sci_port(port);
2642 
2643 	switch (state) {
2644 	case UART_PM_STATE_OFF:
2645 		sci_port_disable(sci_port);
2646 		break;
2647 	default:
2648 		sci_port_enable(sci_port);
2649 		break;
2650 	}
2651 }
2652 
2653 static const char *sci_type(struct uart_port *port)
2654 {
2655 	switch (port->type) {
2656 	case PORT_IRDA:
2657 		return "irda";
2658 	case PORT_SCI:
2659 		return "sci";
2660 	case PORT_SCIF:
2661 		return "scif";
2662 	case PORT_SCIFA:
2663 		return "scifa";
2664 	case PORT_SCIFB:
2665 		return "scifb";
2666 	case PORT_HSCIF:
2667 		return "hscif";
2668 	}
2669 
2670 	return NULL;
2671 }
2672 
2673 static int sci_remap_port(struct uart_port *port)
2674 {
2675 	struct sci_port *sport = to_sci_port(port);
2676 
2677 	/*
2678 	 * Nothing to do if there's already an established membase.
2679 	 */
2680 	if (port->membase)
2681 		return 0;
2682 
2683 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2684 		port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2685 		if (unlikely(!port->membase)) {
2686 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2687 			return -ENXIO;
2688 		}
2689 	} else {
2690 		/*
2691 		 * For the simple (and majority of) cases where we don't
2692 		 * need to do any remapping, just cast the cookie
2693 		 * directly.
2694 		 */
2695 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2696 	}
2697 
2698 	return 0;
2699 }
2700 
2701 static void sci_release_port(struct uart_port *port)
2702 {
2703 	struct sci_port *sport = to_sci_port(port);
2704 
2705 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2706 		iounmap(port->membase);
2707 		port->membase = NULL;
2708 	}
2709 
2710 	release_mem_region(port->mapbase, sport->reg_size);
2711 }
2712 
2713 static int sci_request_port(struct uart_port *port)
2714 {
2715 	struct resource *res;
2716 	struct sci_port *sport = to_sci_port(port);
2717 	int ret;
2718 
2719 	res = request_mem_region(port->mapbase, sport->reg_size,
2720 				 dev_name(port->dev));
2721 	if (unlikely(res == NULL)) {
2722 		dev_err(port->dev, "request_mem_region failed.");
2723 		return -EBUSY;
2724 	}
2725 
2726 	ret = sci_remap_port(port);
2727 	if (unlikely(ret != 0)) {
2728 		release_resource(res);
2729 		return ret;
2730 	}
2731 
2732 	return 0;
2733 }
2734 
2735 static void sci_config_port(struct uart_port *port, int flags)
2736 {
2737 	if (flags & UART_CONFIG_TYPE) {
2738 		struct sci_port *sport = to_sci_port(port);
2739 
2740 		port->type = sport->cfg->type;
2741 		sci_request_port(port);
2742 	}
2743 }
2744 
2745 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2746 {
2747 	if (ser->baud_base < 2400)
2748 		/* No paper tape reader for Mitch.. */
2749 		return -EINVAL;
2750 
2751 	return 0;
2752 }
2753 
2754 static const struct uart_ops sci_uart_ops = {
2755 	.tx_empty	= sci_tx_empty,
2756 	.set_mctrl	= sci_set_mctrl,
2757 	.get_mctrl	= sci_get_mctrl,
2758 	.start_tx	= sci_start_tx,
2759 	.stop_tx	= sci_stop_tx,
2760 	.stop_rx	= sci_stop_rx,
2761 	.enable_ms	= sci_enable_ms,
2762 	.break_ctl	= sci_break_ctl,
2763 	.startup	= sci_startup,
2764 	.shutdown	= sci_shutdown,
2765 	.flush_buffer	= sci_flush_buffer,
2766 	.set_termios	= sci_set_termios,
2767 	.pm		= sci_pm,
2768 	.type		= sci_type,
2769 	.release_port	= sci_release_port,
2770 	.request_port	= sci_request_port,
2771 	.config_port	= sci_config_port,
2772 	.verify_port	= sci_verify_port,
2773 #ifdef CONFIG_CONSOLE_POLL
2774 	.poll_get_char	= sci_poll_get_char,
2775 	.poll_put_char	= sci_poll_put_char,
2776 #endif
2777 };
2778 
2779 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2780 {
2781 	const char *clk_names[] = {
2782 		[SCI_FCK] = "fck",
2783 		[SCI_SCK] = "sck",
2784 		[SCI_BRG_INT] = "brg_int",
2785 		[SCI_SCIF_CLK] = "scif_clk",
2786 	};
2787 	struct clk *clk;
2788 	unsigned int i;
2789 
2790 	if (sci_port->cfg->type == PORT_HSCIF)
2791 		clk_names[SCI_SCK] = "hsck";
2792 
2793 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2794 		clk = devm_clk_get(dev, clk_names[i]);
2795 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2796 			return -EPROBE_DEFER;
2797 
2798 		if (IS_ERR(clk) && i == SCI_FCK) {
2799 			/*
2800 			 * "fck" used to be called "sci_ick", and we need to
2801 			 * maintain DT backward compatibility.
2802 			 */
2803 			clk = devm_clk_get(dev, "sci_ick");
2804 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2805 				return -EPROBE_DEFER;
2806 
2807 			if (!IS_ERR(clk))
2808 				goto found;
2809 
2810 			/*
2811 			 * Not all SH platforms declare a clock lookup entry
2812 			 * for SCI devices, in which case we need to get the
2813 			 * global "peripheral_clk" clock.
2814 			 */
2815 			clk = devm_clk_get(dev, "peripheral_clk");
2816 			if (!IS_ERR(clk))
2817 				goto found;
2818 
2819 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2820 				PTR_ERR(clk));
2821 			return PTR_ERR(clk);
2822 		}
2823 
2824 found:
2825 		if (IS_ERR(clk))
2826 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2827 				PTR_ERR(clk));
2828 		else
2829 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2830 				clk, clk_get_rate(clk));
2831 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2832 	}
2833 	return 0;
2834 }
2835 
2836 static const struct sci_port_params *
2837 sci_probe_regmap(const struct plat_sci_port *cfg)
2838 {
2839 	unsigned int regtype;
2840 
2841 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2842 		return &sci_port_params[cfg->regtype];
2843 
2844 	switch (cfg->type) {
2845 	case PORT_SCI:
2846 		regtype = SCIx_SCI_REGTYPE;
2847 		break;
2848 	case PORT_IRDA:
2849 		regtype = SCIx_IRDA_REGTYPE;
2850 		break;
2851 	case PORT_SCIFA:
2852 		regtype = SCIx_SCIFA_REGTYPE;
2853 		break;
2854 	case PORT_SCIFB:
2855 		regtype = SCIx_SCIFB_REGTYPE;
2856 		break;
2857 	case PORT_SCIF:
2858 		/*
2859 		 * The SH-4 is a bit of a misnomer here, although that's
2860 		 * where this particular port layout originated. This
2861 		 * configuration (or some slight variation thereof)
2862 		 * remains the dominant model for all SCIFs.
2863 		 */
2864 		regtype = SCIx_SH4_SCIF_REGTYPE;
2865 		break;
2866 	case PORT_HSCIF:
2867 		regtype = SCIx_HSCIF_REGTYPE;
2868 		break;
2869 	default:
2870 		pr_err("Can't probe register map for given port\n");
2871 		return NULL;
2872 	}
2873 
2874 	return &sci_port_params[regtype];
2875 }
2876 
2877 static int sci_init_single(struct platform_device *dev,
2878 			   struct sci_port *sci_port, unsigned int index,
2879 			   const struct plat_sci_port *p, bool early)
2880 {
2881 	struct uart_port *port = &sci_port->port;
2882 	const struct resource *res;
2883 	unsigned int i;
2884 	int ret;
2885 
2886 	sci_port->cfg	= p;
2887 
2888 	port->ops	= &sci_uart_ops;
2889 	port->iotype	= UPIO_MEM;
2890 	port->line	= index;
2891 
2892 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2893 	if (res == NULL)
2894 		return -ENOMEM;
2895 
2896 	port->mapbase = res->start;
2897 	sci_port->reg_size = resource_size(res);
2898 
2899 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2900 		sci_port->irqs[i] = platform_get_irq(dev, i);
2901 
2902 	/* The SCI generates several interrupts. They can be muxed together or
2903 	 * connected to different interrupt lines. In the muxed case only one
2904 	 * interrupt resource is specified as there is only one interrupt ID.
2905 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2906 	 * from the SCI, however those signals might have their own individual
2907 	 * interrupt ID numbers, or muxed together with another interrupt.
2908 	 */
2909 	if (sci_port->irqs[0] < 0)
2910 		return -ENXIO;
2911 
2912 	if (sci_port->irqs[1] < 0)
2913 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2914 			sci_port->irqs[i] = sci_port->irqs[0];
2915 
2916 	sci_port->params = sci_probe_regmap(p);
2917 	if (unlikely(sci_port->params == NULL))
2918 		return -EINVAL;
2919 
2920 	switch (p->type) {
2921 	case PORT_SCIFB:
2922 		sci_port->rx_trigger = 48;
2923 		break;
2924 	case PORT_HSCIF:
2925 		sci_port->rx_trigger = 64;
2926 		break;
2927 	case PORT_SCIFA:
2928 		sci_port->rx_trigger = 32;
2929 		break;
2930 	case PORT_SCIF:
2931 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2932 			/* RX triggering not implemented for this IP */
2933 			sci_port->rx_trigger = 1;
2934 		else
2935 			sci_port->rx_trigger = 8;
2936 		break;
2937 	default:
2938 		sci_port->rx_trigger = 1;
2939 		break;
2940 	}
2941 
2942 	sci_port->rx_fifo_timeout = 0;
2943 	sci_port->hscif_tot = 0;
2944 
2945 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2946 	 * match the SoC datasheet, this should be investigated. Let platform
2947 	 * data override the sampling rate for now.
2948 	 */
2949 	sci_port->sampling_rate_mask = p->sampling_rate
2950 				     ? SCI_SR(p->sampling_rate)
2951 				     : sci_port->params->sampling_rate_mask;
2952 
2953 	if (!early) {
2954 		ret = sci_init_clocks(sci_port, &dev->dev);
2955 		if (ret < 0)
2956 			return ret;
2957 
2958 		port->dev = &dev->dev;
2959 
2960 		pm_runtime_enable(&dev->dev);
2961 	}
2962 
2963 	port->type		= p->type;
2964 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2965 	port->fifosize		= sci_port->params->fifosize;
2966 
2967 	if (port->type == PORT_SCI) {
2968 		if (sci_port->reg_size >= 0x20)
2969 			port->regshift = 2;
2970 		else
2971 			port->regshift = 1;
2972 	}
2973 
2974 	/*
2975 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2976 	 * for the multi-IRQ ports, which is where we are primarily
2977 	 * concerned with the shutdown path synchronization.
2978 	 *
2979 	 * For the muxed case there's nothing more to do.
2980 	 */
2981 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2982 	port->irqflags		= 0;
2983 
2984 	port->serial_in		= sci_serial_in;
2985 	port->serial_out	= sci_serial_out;
2986 
2987 	return 0;
2988 }
2989 
2990 static void sci_cleanup_single(struct sci_port *port)
2991 {
2992 	pm_runtime_disable(port->port.dev);
2993 }
2994 
2995 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2996     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2997 static void serial_console_putchar(struct uart_port *port, int ch)
2998 {
2999 	sci_poll_put_char(port, ch);
3000 }
3001 
3002 /*
3003  *	Print a string to the serial port trying not to disturb
3004  *	any possible real use of the port...
3005  */
3006 static void serial_console_write(struct console *co, const char *s,
3007 				 unsigned count)
3008 {
3009 	struct sci_port *sci_port = &sci_ports[co->index];
3010 	struct uart_port *port = &sci_port->port;
3011 	unsigned short bits, ctrl, ctrl_temp;
3012 	unsigned long flags;
3013 	int locked = 1;
3014 
3015 #if defined(SUPPORT_SYSRQ)
3016 	if (port->sysrq)
3017 		locked = 0;
3018 	else
3019 #endif
3020 	if (oops_in_progress)
3021 		locked = spin_trylock_irqsave(&port->lock, flags);
3022 	else
3023 		spin_lock_irqsave(&port->lock, flags);
3024 
3025 	/* first save SCSCR then disable interrupts, keep clock source */
3026 	ctrl = serial_port_in(port, SCSCR);
3027 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3028 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3029 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3030 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3031 
3032 	uart_console_write(port, s, count, serial_console_putchar);
3033 
3034 	/* wait until fifo is empty and last bit has been transmitted */
3035 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3036 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3037 		cpu_relax();
3038 
3039 	/* restore the SCSCR */
3040 	serial_port_out(port, SCSCR, ctrl);
3041 
3042 	if (locked)
3043 		spin_unlock_irqrestore(&port->lock, flags);
3044 }
3045 
3046 static int serial_console_setup(struct console *co, char *options)
3047 {
3048 	struct sci_port *sci_port;
3049 	struct uart_port *port;
3050 	int baud = 115200;
3051 	int bits = 8;
3052 	int parity = 'n';
3053 	int flow = 'n';
3054 	int ret;
3055 
3056 	/*
3057 	 * Refuse to handle any bogus ports.
3058 	 */
3059 	if (co->index < 0 || co->index >= SCI_NPORTS)
3060 		return -ENODEV;
3061 
3062 	sci_port = &sci_ports[co->index];
3063 	port = &sci_port->port;
3064 
3065 	/*
3066 	 * Refuse to handle uninitialized ports.
3067 	 */
3068 	if (!port->ops)
3069 		return -ENODEV;
3070 
3071 	ret = sci_remap_port(port);
3072 	if (unlikely(ret != 0))
3073 		return ret;
3074 
3075 	if (options)
3076 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3077 
3078 	return uart_set_options(port, co, baud, parity, bits, flow);
3079 }
3080 
3081 static struct console serial_console = {
3082 	.name		= "ttySC",
3083 	.device		= uart_console_device,
3084 	.write		= serial_console_write,
3085 	.setup		= serial_console_setup,
3086 	.flags		= CON_PRINTBUFFER,
3087 	.index		= -1,
3088 	.data		= &sci_uart_driver,
3089 };
3090 
3091 static struct console early_serial_console = {
3092 	.name           = "early_ttySC",
3093 	.write          = serial_console_write,
3094 	.flags          = CON_PRINTBUFFER,
3095 	.index		= -1,
3096 };
3097 
3098 static char early_serial_buf[32];
3099 
3100 static int sci_probe_earlyprintk(struct platform_device *pdev)
3101 {
3102 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3103 
3104 	if (early_serial_console.data)
3105 		return -EEXIST;
3106 
3107 	early_serial_console.index = pdev->id;
3108 
3109 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3110 
3111 	serial_console_setup(&early_serial_console, early_serial_buf);
3112 
3113 	if (!strstr(early_serial_buf, "keep"))
3114 		early_serial_console.flags |= CON_BOOT;
3115 
3116 	register_console(&early_serial_console);
3117 	return 0;
3118 }
3119 
3120 #define SCI_CONSOLE	(&serial_console)
3121 
3122 #else
3123 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3124 {
3125 	return -EINVAL;
3126 }
3127 
3128 #define SCI_CONSOLE	NULL
3129 
3130 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3131 
3132 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3133 
3134 static DEFINE_MUTEX(sci_uart_registration_lock);
3135 static struct uart_driver sci_uart_driver = {
3136 	.owner		= THIS_MODULE,
3137 	.driver_name	= "sci",
3138 	.dev_name	= "ttySC",
3139 	.major		= SCI_MAJOR,
3140 	.minor		= SCI_MINOR_START,
3141 	.nr		= SCI_NPORTS,
3142 	.cons		= SCI_CONSOLE,
3143 };
3144 
3145 static int sci_remove(struct platform_device *dev)
3146 {
3147 	struct sci_port *port = platform_get_drvdata(dev);
3148 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3149 
3150 	sci_ports_in_use &= ~BIT(port->port.line);
3151 	uart_remove_one_port(&sci_uart_driver, &port->port);
3152 
3153 	sci_cleanup_single(port);
3154 
3155 	if (port->port.fifosize > 1) {
3156 		sysfs_remove_file(&dev->dev.kobj,
3157 				  &dev_attr_rx_fifo_trigger.attr);
3158 	}
3159 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF) {
3160 		sysfs_remove_file(&dev->dev.kobj,
3161 				  &dev_attr_rx_fifo_timeout.attr);
3162 	}
3163 
3164 	return 0;
3165 }
3166 
3167 
3168 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3169 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3170 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3171 
3172 static const struct of_device_id of_sci_match[] = {
3173 	/* SoC-specific types */
3174 	{
3175 		.compatible = "renesas,scif-r7s72100",
3176 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3177 	},
3178 	{
3179 		.compatible = "renesas,scif-r7s9210",
3180 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3181 	},
3182 	/* Family-specific types */
3183 	{
3184 		.compatible = "renesas,rcar-gen1-scif",
3185 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3186 	}, {
3187 		.compatible = "renesas,rcar-gen2-scif",
3188 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3189 	}, {
3190 		.compatible = "renesas,rcar-gen3-scif",
3191 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3192 	},
3193 	/* Generic types */
3194 	{
3195 		.compatible = "renesas,scif",
3196 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3197 	}, {
3198 		.compatible = "renesas,scifa",
3199 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3200 	}, {
3201 		.compatible = "renesas,scifb",
3202 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3203 	}, {
3204 		.compatible = "renesas,hscif",
3205 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3206 	}, {
3207 		.compatible = "renesas,sci",
3208 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3209 	}, {
3210 		/* Terminator */
3211 	},
3212 };
3213 MODULE_DEVICE_TABLE(of, of_sci_match);
3214 
3215 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3216 					  unsigned int *dev_id)
3217 {
3218 	struct device_node *np = pdev->dev.of_node;
3219 	struct plat_sci_port *p;
3220 	struct sci_port *sp;
3221 	const void *data;
3222 	int id;
3223 
3224 	if (!IS_ENABLED(CONFIG_OF) || !np)
3225 		return NULL;
3226 
3227 	data = of_device_get_match_data(&pdev->dev);
3228 
3229 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3230 	if (!p)
3231 		return NULL;
3232 
3233 	/* Get the line number from the aliases node. */
3234 	id = of_alias_get_id(np, "serial");
3235 	if (id < 0 && ~sci_ports_in_use)
3236 		id = ffz(sci_ports_in_use);
3237 	if (id < 0) {
3238 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3239 		return NULL;
3240 	}
3241 	if (id >= ARRAY_SIZE(sci_ports)) {
3242 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3243 		return NULL;
3244 	}
3245 
3246 	sp = &sci_ports[id];
3247 	*dev_id = id;
3248 
3249 	p->type = SCI_OF_TYPE(data);
3250 	p->regtype = SCI_OF_REGTYPE(data);
3251 
3252 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3253 
3254 	return p;
3255 }
3256 
3257 static int sci_probe_single(struct platform_device *dev,
3258 				      unsigned int index,
3259 				      struct plat_sci_port *p,
3260 				      struct sci_port *sciport)
3261 {
3262 	int ret;
3263 
3264 	/* Sanity check */
3265 	if (unlikely(index >= SCI_NPORTS)) {
3266 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3267 			   index+1, SCI_NPORTS);
3268 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3269 		return -EINVAL;
3270 	}
3271 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3272 	if (sci_ports_in_use & BIT(index))
3273 		return -EBUSY;
3274 
3275 	mutex_lock(&sci_uart_registration_lock);
3276 	if (!sci_uart_driver.state) {
3277 		ret = uart_register_driver(&sci_uart_driver);
3278 		if (ret) {
3279 			mutex_unlock(&sci_uart_registration_lock);
3280 			return ret;
3281 		}
3282 	}
3283 	mutex_unlock(&sci_uart_registration_lock);
3284 
3285 	ret = sci_init_single(dev, sciport, index, p, false);
3286 	if (ret)
3287 		return ret;
3288 
3289 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3290 	if (IS_ERR(sciport->gpios) && PTR_ERR(sciport->gpios) != -ENOSYS)
3291 		return PTR_ERR(sciport->gpios);
3292 
3293 	if (sciport->has_rtscts) {
3294 		if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3295 							UART_GPIO_CTS)) ||
3296 		    !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3297 							UART_GPIO_RTS))) {
3298 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3299 			return -EINVAL;
3300 		}
3301 		sciport->port.flags |= UPF_HARD_FLOW;
3302 	}
3303 
3304 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3305 	if (ret) {
3306 		sci_cleanup_single(sciport);
3307 		return ret;
3308 	}
3309 
3310 	return 0;
3311 }
3312 
3313 static int sci_probe(struct platform_device *dev)
3314 {
3315 	struct plat_sci_port *p;
3316 	struct sci_port *sp;
3317 	unsigned int dev_id;
3318 	int ret;
3319 
3320 	/*
3321 	 * If we've come here via earlyprintk initialization, head off to
3322 	 * the special early probe. We don't have sufficient device state
3323 	 * to make it beyond this yet.
3324 	 */
3325 	if (is_early_platform_device(dev))
3326 		return sci_probe_earlyprintk(dev);
3327 
3328 	if (dev->dev.of_node) {
3329 		p = sci_parse_dt(dev, &dev_id);
3330 		if (p == NULL)
3331 			return -EINVAL;
3332 	} else {
3333 		p = dev->dev.platform_data;
3334 		if (p == NULL) {
3335 			dev_err(&dev->dev, "no platform data supplied\n");
3336 			return -EINVAL;
3337 		}
3338 
3339 		dev_id = dev->id;
3340 	}
3341 
3342 	sp = &sci_ports[dev_id];
3343 	platform_set_drvdata(dev, sp);
3344 
3345 	ret = sci_probe_single(dev, dev_id, p, sp);
3346 	if (ret)
3347 		return ret;
3348 
3349 	if (sp->port.fifosize > 1) {
3350 		ret = sysfs_create_file(&dev->dev.kobj,
3351 				&dev_attr_rx_fifo_trigger.attr);
3352 		if (ret)
3353 			return ret;
3354 	}
3355 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3356 	    sp->port.type == PORT_HSCIF) {
3357 		ret = sysfs_create_file(&dev->dev.kobj,
3358 				&dev_attr_rx_fifo_timeout.attr);
3359 		if (ret) {
3360 			if (sp->port.fifosize > 1) {
3361 				sysfs_remove_file(&dev->dev.kobj,
3362 					&dev_attr_rx_fifo_trigger.attr);
3363 			}
3364 			return ret;
3365 		}
3366 	}
3367 
3368 #ifdef CONFIG_SH_STANDARD_BIOS
3369 	sh_bios_gdb_detach();
3370 #endif
3371 
3372 	sci_ports_in_use |= BIT(dev_id);
3373 	return 0;
3374 }
3375 
3376 static __maybe_unused int sci_suspend(struct device *dev)
3377 {
3378 	struct sci_port *sport = dev_get_drvdata(dev);
3379 
3380 	if (sport)
3381 		uart_suspend_port(&sci_uart_driver, &sport->port);
3382 
3383 	return 0;
3384 }
3385 
3386 static __maybe_unused int sci_resume(struct device *dev)
3387 {
3388 	struct sci_port *sport = dev_get_drvdata(dev);
3389 
3390 	if (sport)
3391 		uart_resume_port(&sci_uart_driver, &sport->port);
3392 
3393 	return 0;
3394 }
3395 
3396 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3397 
3398 static struct platform_driver sci_driver = {
3399 	.probe		= sci_probe,
3400 	.remove		= sci_remove,
3401 	.driver		= {
3402 		.name	= "sh-sci",
3403 		.pm	= &sci_dev_pm_ops,
3404 		.of_match_table = of_match_ptr(of_sci_match),
3405 	},
3406 };
3407 
3408 static int __init sci_init(void)
3409 {
3410 	pr_info("%s\n", banner);
3411 
3412 	return platform_driver_register(&sci_driver);
3413 }
3414 
3415 static void __exit sci_exit(void)
3416 {
3417 	platform_driver_unregister(&sci_driver);
3418 
3419 	if (sci_uart_driver.state)
3420 		uart_unregister_driver(&sci_uart_driver);
3421 }
3422 
3423 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3424 early_platform_init_buffer("earlyprintk", &sci_driver,
3425 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3426 #endif
3427 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3428 static struct plat_sci_port port_cfg __initdata;
3429 
3430 static int __init early_console_setup(struct earlycon_device *device,
3431 				      int type)
3432 {
3433 	if (!device->port.membase)
3434 		return -ENODEV;
3435 
3436 	device->port.serial_in = sci_serial_in;
3437 	device->port.serial_out	= sci_serial_out;
3438 	device->port.type = type;
3439 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3440 	port_cfg.type = type;
3441 	sci_ports[0].cfg = &port_cfg;
3442 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3443 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3444 	sci_serial_out(&sci_ports[0].port, SCSCR,
3445 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3446 
3447 	device->con->write = serial_console_write;
3448 	return 0;
3449 }
3450 static int __init sci_early_console_setup(struct earlycon_device *device,
3451 					  const char *opt)
3452 {
3453 	return early_console_setup(device, PORT_SCI);
3454 }
3455 static int __init scif_early_console_setup(struct earlycon_device *device,
3456 					  const char *opt)
3457 {
3458 	return early_console_setup(device, PORT_SCIF);
3459 }
3460 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3461 					  const char *opt)
3462 {
3463 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3464 	return early_console_setup(device, PORT_SCIF);
3465 }
3466 static int __init scifa_early_console_setup(struct earlycon_device *device,
3467 					  const char *opt)
3468 {
3469 	return early_console_setup(device, PORT_SCIFA);
3470 }
3471 static int __init scifb_early_console_setup(struct earlycon_device *device,
3472 					  const char *opt)
3473 {
3474 	return early_console_setup(device, PORT_SCIFB);
3475 }
3476 static int __init hscif_early_console_setup(struct earlycon_device *device,
3477 					  const char *opt)
3478 {
3479 	return early_console_setup(device, PORT_HSCIF);
3480 }
3481 
3482 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3483 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3484 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3485 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3486 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3487 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3488 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3489 
3490 module_init(sci_init);
3491 module_exit(sci_exit);
3492 
3493 MODULE_LICENSE("GPL");
3494 MODULE_ALIAS("platform:sh-sci");
3495 MODULE_AUTHOR("Paul Mundt");
3496 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3497