xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision cef69974)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #undef DEBUG
19 
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/module.h>
35 #include <linux/mm.h>
36 #include <linux/of.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm_runtime.h>
40 #include <linux/reset.h>
41 #include <linux/scatterlist.h>
42 #include <linux/serial.h>
43 #include <linux/serial_sci.h>
44 #include <linux/sh_dma.h>
45 #include <linux/slab.h>
46 #include <linux/string.h>
47 #include <linux/sysrq.h>
48 #include <linux/timer.h>
49 #include <linux/tty.h>
50 #include <linux/tty_flip.h>
51 
52 #ifdef CONFIG_SUPERH
53 #include <asm/sh_bios.h>
54 #include <asm/platform_early.h>
55 #endif
56 
57 #include "serial_mctrl_gpio.h"
58 #include "sh-sci.h"
59 
60 /* Offsets into the sci_port->irqs array */
61 enum {
62 	SCIx_ERI_IRQ,
63 	SCIx_RXI_IRQ,
64 	SCIx_TXI_IRQ,
65 	SCIx_BRI_IRQ,
66 	SCIx_DRI_IRQ,
67 	SCIx_TEI_IRQ,
68 	SCIx_NR_IRQS,
69 
70 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
71 };
72 
73 #define SCIx_IRQ_IS_MUXED(port)			\
74 	((port)->irqs[SCIx_ERI_IRQ] ==	\
75 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
76 	((port)->irqs[SCIx_ERI_IRQ] &&	\
77 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
78 
79 enum SCI_CLKS {
80 	SCI_FCK,		/* Functional Clock */
81 	SCI_SCK,		/* Optional External Clock */
82 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
83 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
84 	SCI_NUM_CLKS
85 };
86 
87 /* Bit x set means sampling rate x + 1 is supported */
88 #define SCI_SR(x)		BIT((x) - 1)
89 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
90 
91 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
92 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
93 				SCI_SR(19) | SCI_SR(27)
94 
95 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
96 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
97 
98 /* Iterate over all supported sampling rates, from high to low */
99 #define for_each_sr(_sr, _port)						\
100 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
101 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
102 
103 struct plat_sci_reg {
104 	u8 offset, size;
105 };
106 
107 struct sci_port_params {
108 	const struct plat_sci_reg regs[SCIx_NR_REGS];
109 	unsigned int fifosize;
110 	unsigned int overrun_reg;
111 	unsigned int overrun_mask;
112 	unsigned int sampling_rate_mask;
113 	unsigned int error_mask;
114 	unsigned int error_clear;
115 };
116 
117 struct sci_port {
118 	struct uart_port	port;
119 
120 	/* Platform configuration */
121 	const struct sci_port_params *params;
122 	const struct plat_sci_port *cfg;
123 	unsigned int		sampling_rate_mask;
124 	resource_size_t		reg_size;
125 	struct mctrl_gpios	*gpios;
126 
127 	/* Clocks */
128 	struct clk		*clks[SCI_NUM_CLKS];
129 	unsigned long		clk_rates[SCI_NUM_CLKS];
130 
131 	int			irqs[SCIx_NR_IRQS];
132 	char			*irqstr[SCIx_NR_IRQS];
133 
134 	struct dma_chan			*chan_tx;
135 	struct dma_chan			*chan_rx;
136 
137 #ifdef CONFIG_SERIAL_SH_SCI_DMA
138 	struct dma_chan			*chan_tx_saved;
139 	struct dma_chan			*chan_rx_saved;
140 	dma_cookie_t			cookie_tx;
141 	dma_cookie_t			cookie_rx[2];
142 	dma_cookie_t			active_rx;
143 	dma_addr_t			tx_dma_addr;
144 	unsigned int			tx_dma_len;
145 	struct scatterlist		sg_rx[2];
146 	void				*rx_buf[2];
147 	size_t				buf_len_rx;
148 	struct work_struct		work_tx;
149 	struct hrtimer			rx_timer;
150 	unsigned int			rx_timeout;	/* microseconds */
151 #endif
152 	unsigned int			rx_frame;
153 	int				rx_trigger;
154 	struct timer_list		rx_fifo_timer;
155 	int				rx_fifo_timeout;
156 	u16				hscif_tot;
157 
158 	bool has_rtscts;
159 	bool autorts;
160 };
161 
162 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
163 
164 static struct sci_port sci_ports[SCI_NPORTS];
165 static unsigned long sci_ports_in_use;
166 static struct uart_driver sci_uart_driver;
167 
168 static inline struct sci_port *
169 to_sci_port(struct uart_port *uart)
170 {
171 	return container_of(uart, struct sci_port, port);
172 }
173 
174 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
175 	/*
176 	 * Common SCI definitions, dependent on the port's regshift
177 	 * value.
178 	 */
179 	[SCIx_SCI_REGTYPE] = {
180 		.regs = {
181 			[SCSMR]		= { 0x00,  8 },
182 			[SCBRR]		= { 0x01,  8 },
183 			[SCSCR]		= { 0x02,  8 },
184 			[SCxTDR]	= { 0x03,  8 },
185 			[SCxSR]		= { 0x04,  8 },
186 			[SCxRDR]	= { 0x05,  8 },
187 		},
188 		.fifosize = 1,
189 		.overrun_reg = SCxSR,
190 		.overrun_mask = SCI_ORER,
191 		.sampling_rate_mask = SCI_SR(32),
192 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
193 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
194 	},
195 
196 	/*
197 	 * Common definitions for legacy IrDA ports.
198 	 */
199 	[SCIx_IRDA_REGTYPE] = {
200 		.regs = {
201 			[SCSMR]		= { 0x00,  8 },
202 			[SCBRR]		= { 0x02,  8 },
203 			[SCSCR]		= { 0x04,  8 },
204 			[SCxTDR]	= { 0x06,  8 },
205 			[SCxSR]		= { 0x08, 16 },
206 			[SCxRDR]	= { 0x0a,  8 },
207 			[SCFCR]		= { 0x0c,  8 },
208 			[SCFDR]		= { 0x0e, 16 },
209 		},
210 		.fifosize = 1,
211 		.overrun_reg = SCxSR,
212 		.overrun_mask = SCI_ORER,
213 		.sampling_rate_mask = SCI_SR(32),
214 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
215 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
216 	},
217 
218 	/*
219 	 * Common SCIFA definitions.
220 	 */
221 	[SCIx_SCIFA_REGTYPE] = {
222 		.regs = {
223 			[SCSMR]		= { 0x00, 16 },
224 			[SCBRR]		= { 0x04,  8 },
225 			[SCSCR]		= { 0x08, 16 },
226 			[SCxTDR]	= { 0x20,  8 },
227 			[SCxSR]		= { 0x14, 16 },
228 			[SCxRDR]	= { 0x24,  8 },
229 			[SCFCR]		= { 0x18, 16 },
230 			[SCFDR]		= { 0x1c, 16 },
231 			[SCPCR]		= { 0x30, 16 },
232 			[SCPDR]		= { 0x34, 16 },
233 		},
234 		.fifosize = 64,
235 		.overrun_reg = SCxSR,
236 		.overrun_mask = SCIFA_ORER,
237 		.sampling_rate_mask = SCI_SR_SCIFAB,
238 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
239 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
240 	},
241 
242 	/*
243 	 * Common SCIFB definitions.
244 	 */
245 	[SCIx_SCIFB_REGTYPE] = {
246 		.regs = {
247 			[SCSMR]		= { 0x00, 16 },
248 			[SCBRR]		= { 0x04,  8 },
249 			[SCSCR]		= { 0x08, 16 },
250 			[SCxTDR]	= { 0x40,  8 },
251 			[SCxSR]		= { 0x14, 16 },
252 			[SCxRDR]	= { 0x60,  8 },
253 			[SCFCR]		= { 0x18, 16 },
254 			[SCTFDR]	= { 0x38, 16 },
255 			[SCRFDR]	= { 0x3c, 16 },
256 			[SCPCR]		= { 0x30, 16 },
257 			[SCPDR]		= { 0x34, 16 },
258 		},
259 		.fifosize = 256,
260 		.overrun_reg = SCxSR,
261 		.overrun_mask = SCIFA_ORER,
262 		.sampling_rate_mask = SCI_SR_SCIFAB,
263 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
264 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
265 	},
266 
267 	/*
268 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
269 	 * count registers.
270 	 */
271 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
272 		.regs = {
273 			[SCSMR]		= { 0x00, 16 },
274 			[SCBRR]		= { 0x04,  8 },
275 			[SCSCR]		= { 0x08, 16 },
276 			[SCxTDR]	= { 0x0c,  8 },
277 			[SCxSR]		= { 0x10, 16 },
278 			[SCxRDR]	= { 0x14,  8 },
279 			[SCFCR]		= { 0x18, 16 },
280 			[SCFDR]		= { 0x1c, 16 },
281 			[SCSPTR]	= { 0x20, 16 },
282 			[SCLSR]		= { 0x24, 16 },
283 		},
284 		.fifosize = 16,
285 		.overrun_reg = SCLSR,
286 		.overrun_mask = SCLSR_ORER,
287 		.sampling_rate_mask = SCI_SR(32),
288 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
289 		.error_clear = SCIF_ERROR_CLEAR,
290 	},
291 
292 	/*
293 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
294 	 * It looks like a normal SCIF with FIFO data, but with a
295 	 * compressed address space. Also, the break out of interrupts
296 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
297 	 */
298 	[SCIx_RZ_SCIFA_REGTYPE] = {
299 		.regs = {
300 			[SCSMR]		= { 0x00, 16 },
301 			[SCBRR]		= { 0x02,  8 },
302 			[SCSCR]		= { 0x04, 16 },
303 			[SCxTDR]	= { 0x06,  8 },
304 			[SCxSR]		= { 0x08, 16 },
305 			[SCxRDR]	= { 0x0A,  8 },
306 			[SCFCR]		= { 0x0C, 16 },
307 			[SCFDR]		= { 0x0E, 16 },
308 			[SCSPTR]	= { 0x10, 16 },
309 			[SCLSR]		= { 0x12, 16 },
310 			[SEMR]		= { 0x14, 8 },
311 		},
312 		.fifosize = 16,
313 		.overrun_reg = SCLSR,
314 		.overrun_mask = SCLSR_ORER,
315 		.sampling_rate_mask = SCI_SR(32),
316 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
317 		.error_clear = SCIF_ERROR_CLEAR,
318 	},
319 
320 	/*
321 	 * Common SH-3 SCIF definitions.
322 	 */
323 	[SCIx_SH3_SCIF_REGTYPE] = {
324 		.regs = {
325 			[SCSMR]		= { 0x00,  8 },
326 			[SCBRR]		= { 0x02,  8 },
327 			[SCSCR]		= { 0x04,  8 },
328 			[SCxTDR]	= { 0x06,  8 },
329 			[SCxSR]		= { 0x08, 16 },
330 			[SCxRDR]	= { 0x0a,  8 },
331 			[SCFCR]		= { 0x0c,  8 },
332 			[SCFDR]		= { 0x0e, 16 },
333 		},
334 		.fifosize = 16,
335 		.overrun_reg = SCLSR,
336 		.overrun_mask = SCLSR_ORER,
337 		.sampling_rate_mask = SCI_SR(32),
338 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
339 		.error_clear = SCIF_ERROR_CLEAR,
340 	},
341 
342 	/*
343 	 * Common SH-4(A) SCIF(B) definitions.
344 	 */
345 	[SCIx_SH4_SCIF_REGTYPE] = {
346 		.regs = {
347 			[SCSMR]		= { 0x00, 16 },
348 			[SCBRR]		= { 0x04,  8 },
349 			[SCSCR]		= { 0x08, 16 },
350 			[SCxTDR]	= { 0x0c,  8 },
351 			[SCxSR]		= { 0x10, 16 },
352 			[SCxRDR]	= { 0x14,  8 },
353 			[SCFCR]		= { 0x18, 16 },
354 			[SCFDR]		= { 0x1c, 16 },
355 			[SCSPTR]	= { 0x20, 16 },
356 			[SCLSR]		= { 0x24, 16 },
357 		},
358 		.fifosize = 16,
359 		.overrun_reg = SCLSR,
360 		.overrun_mask = SCLSR_ORER,
361 		.sampling_rate_mask = SCI_SR(32),
362 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
363 		.error_clear = SCIF_ERROR_CLEAR,
364 	},
365 
366 	/*
367 	 * Common SCIF definitions for ports with a Baud Rate Generator for
368 	 * External Clock (BRG).
369 	 */
370 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
371 		.regs = {
372 			[SCSMR]		= { 0x00, 16 },
373 			[SCBRR]		= { 0x04,  8 },
374 			[SCSCR]		= { 0x08, 16 },
375 			[SCxTDR]	= { 0x0c,  8 },
376 			[SCxSR]		= { 0x10, 16 },
377 			[SCxRDR]	= { 0x14,  8 },
378 			[SCFCR]		= { 0x18, 16 },
379 			[SCFDR]		= { 0x1c, 16 },
380 			[SCSPTR]	= { 0x20, 16 },
381 			[SCLSR]		= { 0x24, 16 },
382 			[SCDL]		= { 0x30, 16 },
383 			[SCCKS]		= { 0x34, 16 },
384 		},
385 		.fifosize = 16,
386 		.overrun_reg = SCLSR,
387 		.overrun_mask = SCLSR_ORER,
388 		.sampling_rate_mask = SCI_SR(32),
389 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
390 		.error_clear = SCIF_ERROR_CLEAR,
391 	},
392 
393 	/*
394 	 * Common HSCIF definitions.
395 	 */
396 	[SCIx_HSCIF_REGTYPE] = {
397 		.regs = {
398 			[SCSMR]		= { 0x00, 16 },
399 			[SCBRR]		= { 0x04,  8 },
400 			[SCSCR]		= { 0x08, 16 },
401 			[SCxTDR]	= { 0x0c,  8 },
402 			[SCxSR]		= { 0x10, 16 },
403 			[SCxRDR]	= { 0x14,  8 },
404 			[SCFCR]		= { 0x18, 16 },
405 			[SCFDR]		= { 0x1c, 16 },
406 			[SCSPTR]	= { 0x20, 16 },
407 			[SCLSR]		= { 0x24, 16 },
408 			[HSSRR]		= { 0x40, 16 },
409 			[SCDL]		= { 0x30, 16 },
410 			[SCCKS]		= { 0x34, 16 },
411 			[HSRTRGR]	= { 0x54, 16 },
412 			[HSTTRGR]	= { 0x58, 16 },
413 		},
414 		.fifosize = 128,
415 		.overrun_reg = SCLSR,
416 		.overrun_mask = SCLSR_ORER,
417 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
418 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
419 		.error_clear = SCIF_ERROR_CLEAR,
420 	},
421 
422 	/*
423 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
424 	 * register.
425 	 */
426 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
427 		.regs = {
428 			[SCSMR]		= { 0x00, 16 },
429 			[SCBRR]		= { 0x04,  8 },
430 			[SCSCR]		= { 0x08, 16 },
431 			[SCxTDR]	= { 0x0c,  8 },
432 			[SCxSR]		= { 0x10, 16 },
433 			[SCxRDR]	= { 0x14,  8 },
434 			[SCFCR]		= { 0x18, 16 },
435 			[SCFDR]		= { 0x1c, 16 },
436 			[SCLSR]		= { 0x24, 16 },
437 		},
438 		.fifosize = 16,
439 		.overrun_reg = SCLSR,
440 		.overrun_mask = SCLSR_ORER,
441 		.sampling_rate_mask = SCI_SR(32),
442 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
443 		.error_clear = SCIF_ERROR_CLEAR,
444 	},
445 
446 	/*
447 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
448 	 * count registers.
449 	 */
450 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
451 		.regs = {
452 			[SCSMR]		= { 0x00, 16 },
453 			[SCBRR]		= { 0x04,  8 },
454 			[SCSCR]		= { 0x08, 16 },
455 			[SCxTDR]	= { 0x0c,  8 },
456 			[SCxSR]		= { 0x10, 16 },
457 			[SCxRDR]	= { 0x14,  8 },
458 			[SCFCR]		= { 0x18, 16 },
459 			[SCFDR]		= { 0x1c, 16 },
460 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
461 			[SCRFDR]	= { 0x20, 16 },
462 			[SCSPTR]	= { 0x24, 16 },
463 			[SCLSR]		= { 0x28, 16 },
464 		},
465 		.fifosize = 16,
466 		.overrun_reg = SCLSR,
467 		.overrun_mask = SCLSR_ORER,
468 		.sampling_rate_mask = SCI_SR(32),
469 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
470 		.error_clear = SCIF_ERROR_CLEAR,
471 	},
472 
473 	/*
474 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
475 	 * registers.
476 	 */
477 	[SCIx_SH7705_SCIF_REGTYPE] = {
478 		.regs = {
479 			[SCSMR]		= { 0x00, 16 },
480 			[SCBRR]		= { 0x04,  8 },
481 			[SCSCR]		= { 0x08, 16 },
482 			[SCxTDR]	= { 0x20,  8 },
483 			[SCxSR]		= { 0x14, 16 },
484 			[SCxRDR]	= { 0x24,  8 },
485 			[SCFCR]		= { 0x18, 16 },
486 			[SCFDR]		= { 0x1c, 16 },
487 		},
488 		.fifosize = 64,
489 		.overrun_reg = SCxSR,
490 		.overrun_mask = SCIFA_ORER,
491 		.sampling_rate_mask = SCI_SR(16),
492 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
493 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
494 	},
495 };
496 
497 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
498 
499 /*
500  * The "offset" here is rather misleading, in that it refers to an enum
501  * value relative to the port mapping rather than the fixed offset
502  * itself, which needs to be manually retrieved from the platform's
503  * register map for the given port.
504  */
505 static unsigned int sci_serial_in(struct uart_port *p, int offset)
506 {
507 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
508 
509 	if (reg->size == 8)
510 		return ioread8(p->membase + (reg->offset << p->regshift));
511 	else if (reg->size == 16)
512 		return ioread16(p->membase + (reg->offset << p->regshift));
513 	else
514 		WARN(1, "Invalid register access\n");
515 
516 	return 0;
517 }
518 
519 static void sci_serial_out(struct uart_port *p, int offset, int value)
520 {
521 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
522 
523 	if (reg->size == 8)
524 		iowrite8(value, p->membase + (reg->offset << p->regshift));
525 	else if (reg->size == 16)
526 		iowrite16(value, p->membase + (reg->offset << p->regshift));
527 	else
528 		WARN(1, "Invalid register access\n");
529 }
530 
531 static void sci_port_enable(struct sci_port *sci_port)
532 {
533 	unsigned int i;
534 
535 	if (!sci_port->port.dev)
536 		return;
537 
538 	pm_runtime_get_sync(sci_port->port.dev);
539 
540 	for (i = 0; i < SCI_NUM_CLKS; i++) {
541 		clk_prepare_enable(sci_port->clks[i]);
542 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
543 	}
544 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
545 }
546 
547 static void sci_port_disable(struct sci_port *sci_port)
548 {
549 	unsigned int i;
550 
551 	if (!sci_port->port.dev)
552 		return;
553 
554 	for (i = SCI_NUM_CLKS; i-- > 0; )
555 		clk_disable_unprepare(sci_port->clks[i]);
556 
557 	pm_runtime_put_sync(sci_port->port.dev);
558 }
559 
560 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
561 {
562 	/*
563 	 * Not all ports (such as SCIFA) will support REIE. Rather than
564 	 * special-casing the port type, we check the port initialization
565 	 * IRQ enable mask to see whether the IRQ is desired at all. If
566 	 * it's unset, it's logically inferred that there's no point in
567 	 * testing for it.
568 	 */
569 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
570 }
571 
572 static void sci_start_tx(struct uart_port *port)
573 {
574 	struct sci_port *s = to_sci_port(port);
575 	unsigned short ctrl;
576 
577 #ifdef CONFIG_SERIAL_SH_SCI_DMA
578 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
579 		u16 new, scr = serial_port_in(port, SCSCR);
580 		if (s->chan_tx)
581 			new = scr | SCSCR_TDRQE;
582 		else
583 			new = scr & ~SCSCR_TDRQE;
584 		if (new != scr)
585 			serial_port_out(port, SCSCR, new);
586 	}
587 
588 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
589 	    dma_submit_error(s->cookie_tx)) {
590 		s->cookie_tx = 0;
591 		schedule_work(&s->work_tx);
592 	}
593 #endif
594 
595 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
596 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
597 		ctrl = serial_port_in(port, SCSCR);
598 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
599 	}
600 }
601 
602 static void sci_stop_tx(struct uart_port *port)
603 {
604 	unsigned short ctrl;
605 
606 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
607 	ctrl = serial_port_in(port, SCSCR);
608 
609 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
610 		ctrl &= ~SCSCR_TDRQE;
611 
612 	ctrl &= ~SCSCR_TIE;
613 
614 	serial_port_out(port, SCSCR, ctrl);
615 
616 #ifdef CONFIG_SERIAL_SH_SCI_DMA
617 	if (to_sci_port(port)->chan_tx &&
618 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
619 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
620 		to_sci_port(port)->cookie_tx = -EINVAL;
621 	}
622 #endif
623 }
624 
625 static void sci_start_rx(struct uart_port *port)
626 {
627 	unsigned short ctrl;
628 
629 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
630 
631 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
632 		ctrl &= ~SCSCR_RDRQE;
633 
634 	serial_port_out(port, SCSCR, ctrl);
635 }
636 
637 static void sci_stop_rx(struct uart_port *port)
638 {
639 	unsigned short ctrl;
640 
641 	ctrl = serial_port_in(port, SCSCR);
642 
643 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
644 		ctrl &= ~SCSCR_RDRQE;
645 
646 	ctrl &= ~port_rx_irq_mask(port);
647 
648 	serial_port_out(port, SCSCR, ctrl);
649 }
650 
651 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
652 {
653 	if (port->type == PORT_SCI) {
654 		/* Just store the mask */
655 		serial_port_out(port, SCxSR, mask);
656 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
657 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
658 		/* Only clear the status bits we want to clear */
659 		serial_port_out(port, SCxSR,
660 				serial_port_in(port, SCxSR) & mask);
661 	} else {
662 		/* Store the mask, clear parity/framing errors */
663 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
664 	}
665 }
666 
667 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
668     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
669 
670 #ifdef CONFIG_CONSOLE_POLL
671 static int sci_poll_get_char(struct uart_port *port)
672 {
673 	unsigned short status;
674 	int c;
675 
676 	do {
677 		status = serial_port_in(port, SCxSR);
678 		if (status & SCxSR_ERRORS(port)) {
679 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
680 			continue;
681 		}
682 		break;
683 	} while (1);
684 
685 	if (!(status & SCxSR_RDxF(port)))
686 		return NO_POLL_CHAR;
687 
688 	c = serial_port_in(port, SCxRDR);
689 
690 	/* Dummy read */
691 	serial_port_in(port, SCxSR);
692 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
693 
694 	return c;
695 }
696 #endif
697 
698 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
699 {
700 	unsigned short status;
701 
702 	do {
703 		status = serial_port_in(port, SCxSR);
704 	} while (!(status & SCxSR_TDxE(port)));
705 
706 	serial_port_out(port, SCxTDR, c);
707 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
708 }
709 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
710 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
711 
712 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
713 {
714 	struct sci_port *s = to_sci_port(port);
715 
716 	/*
717 	 * Use port-specific handler if provided.
718 	 */
719 	if (s->cfg->ops && s->cfg->ops->init_pins) {
720 		s->cfg->ops->init_pins(port, cflag);
721 		return;
722 	}
723 
724 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
725 		u16 data = serial_port_in(port, SCPDR);
726 		u16 ctrl = serial_port_in(port, SCPCR);
727 
728 		/* Enable RXD and TXD pin functions */
729 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
730 		if (to_sci_port(port)->has_rtscts) {
731 			/* RTS# is output, active low, unless autorts */
732 			if (!(port->mctrl & TIOCM_RTS)) {
733 				ctrl |= SCPCR_RTSC;
734 				data |= SCPDR_RTSD;
735 			} else if (!s->autorts) {
736 				ctrl |= SCPCR_RTSC;
737 				data &= ~SCPDR_RTSD;
738 			} else {
739 				/* Enable RTS# pin function */
740 				ctrl &= ~SCPCR_RTSC;
741 			}
742 			/* Enable CTS# pin function */
743 			ctrl &= ~SCPCR_CTSC;
744 		}
745 		serial_port_out(port, SCPDR, data);
746 		serial_port_out(port, SCPCR, ctrl);
747 	} else if (sci_getreg(port, SCSPTR)->size) {
748 		u16 status = serial_port_in(port, SCSPTR);
749 
750 		/* RTS# is always output; and active low, unless autorts */
751 		status |= SCSPTR_RTSIO;
752 		if (!(port->mctrl & TIOCM_RTS))
753 			status |= SCSPTR_RTSDT;
754 		else if (!s->autorts)
755 			status &= ~SCSPTR_RTSDT;
756 		/* CTS# and SCK are inputs */
757 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
758 		serial_port_out(port, SCSPTR, status);
759 	}
760 }
761 
762 static int sci_txfill(struct uart_port *port)
763 {
764 	struct sci_port *s = to_sci_port(port);
765 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
766 	const struct plat_sci_reg *reg;
767 
768 	reg = sci_getreg(port, SCTFDR);
769 	if (reg->size)
770 		return serial_port_in(port, SCTFDR) & fifo_mask;
771 
772 	reg = sci_getreg(port, SCFDR);
773 	if (reg->size)
774 		return serial_port_in(port, SCFDR) >> 8;
775 
776 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
777 }
778 
779 static int sci_txroom(struct uart_port *port)
780 {
781 	return port->fifosize - sci_txfill(port);
782 }
783 
784 static int sci_rxfill(struct uart_port *port)
785 {
786 	struct sci_port *s = to_sci_port(port);
787 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
788 	const struct plat_sci_reg *reg;
789 
790 	reg = sci_getreg(port, SCRFDR);
791 	if (reg->size)
792 		return serial_port_in(port, SCRFDR) & fifo_mask;
793 
794 	reg = sci_getreg(port, SCFDR);
795 	if (reg->size)
796 		return serial_port_in(port, SCFDR) & fifo_mask;
797 
798 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
799 }
800 
801 /* ********************************************************************** *
802  *                   the interrupt related routines                       *
803  * ********************************************************************** */
804 
805 static void sci_transmit_chars(struct uart_port *port)
806 {
807 	struct circ_buf *xmit = &port->state->xmit;
808 	unsigned int stopped = uart_tx_stopped(port);
809 	unsigned short status;
810 	unsigned short ctrl;
811 	int count;
812 
813 	status = serial_port_in(port, SCxSR);
814 	if (!(status & SCxSR_TDxE(port))) {
815 		ctrl = serial_port_in(port, SCSCR);
816 		if (uart_circ_empty(xmit))
817 			ctrl &= ~SCSCR_TIE;
818 		else
819 			ctrl |= SCSCR_TIE;
820 		serial_port_out(port, SCSCR, ctrl);
821 		return;
822 	}
823 
824 	count = sci_txroom(port);
825 
826 	do {
827 		unsigned char c;
828 
829 		if (port->x_char) {
830 			c = port->x_char;
831 			port->x_char = 0;
832 		} else if (!uart_circ_empty(xmit) && !stopped) {
833 			c = xmit->buf[xmit->tail];
834 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
835 		} else {
836 			break;
837 		}
838 
839 		serial_port_out(port, SCxTDR, c);
840 
841 		port->icount.tx++;
842 	} while (--count > 0);
843 
844 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
845 
846 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
847 		uart_write_wakeup(port);
848 	if (uart_circ_empty(xmit))
849 		sci_stop_tx(port);
850 
851 }
852 
853 static void sci_receive_chars(struct uart_port *port)
854 {
855 	struct tty_port *tport = &port->state->port;
856 	int i, count, copied = 0;
857 	unsigned short status;
858 	unsigned char flag;
859 
860 	status = serial_port_in(port, SCxSR);
861 	if (!(status & SCxSR_RDxF(port)))
862 		return;
863 
864 	while (1) {
865 		/* Don't copy more bytes than there is room for in the buffer */
866 		count = tty_buffer_request_room(tport, sci_rxfill(port));
867 
868 		/* If for any reason we can't copy more data, we're done! */
869 		if (count == 0)
870 			break;
871 
872 		if (port->type == PORT_SCI) {
873 			char c = serial_port_in(port, SCxRDR);
874 			if (uart_handle_sysrq_char(port, c))
875 				count = 0;
876 			else
877 				tty_insert_flip_char(tport, c, TTY_NORMAL);
878 		} else {
879 			for (i = 0; i < count; i++) {
880 				char c;
881 
882 				if (port->type == PORT_SCIF ||
883 				    port->type == PORT_HSCIF) {
884 					status = serial_port_in(port, SCxSR);
885 					c = serial_port_in(port, SCxRDR);
886 				} else {
887 					c = serial_port_in(port, SCxRDR);
888 					status = serial_port_in(port, SCxSR);
889 				}
890 				if (uart_handle_sysrq_char(port, c)) {
891 					count--; i--;
892 					continue;
893 				}
894 
895 				/* Store data and status */
896 				if (status & SCxSR_FER(port)) {
897 					flag = TTY_FRAME;
898 					port->icount.frame++;
899 				} else if (status & SCxSR_PER(port)) {
900 					flag = TTY_PARITY;
901 					port->icount.parity++;
902 				} else
903 					flag = TTY_NORMAL;
904 
905 				tty_insert_flip_char(tport, c, flag);
906 			}
907 		}
908 
909 		serial_port_in(port, SCxSR); /* dummy read */
910 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
911 
912 		copied += count;
913 		port->icount.rx += count;
914 	}
915 
916 	if (copied) {
917 		/* Tell the rest of the system the news. New characters! */
918 		tty_flip_buffer_push(tport);
919 	} else {
920 		/* TTY buffers full; read from RX reg to prevent lockup */
921 		serial_port_in(port, SCxRDR);
922 		serial_port_in(port, SCxSR); /* dummy read */
923 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
924 	}
925 }
926 
927 static int sci_handle_errors(struct uart_port *port)
928 {
929 	int copied = 0;
930 	unsigned short status = serial_port_in(port, SCxSR);
931 	struct tty_port *tport = &port->state->port;
932 	struct sci_port *s = to_sci_port(port);
933 
934 	/* Handle overruns */
935 	if (status & s->params->overrun_mask) {
936 		port->icount.overrun++;
937 
938 		/* overrun error */
939 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
940 			copied++;
941 	}
942 
943 	if (status & SCxSR_FER(port)) {
944 		/* frame error */
945 		port->icount.frame++;
946 
947 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
948 			copied++;
949 	}
950 
951 	if (status & SCxSR_PER(port)) {
952 		/* parity error */
953 		port->icount.parity++;
954 
955 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
956 			copied++;
957 	}
958 
959 	if (copied)
960 		tty_flip_buffer_push(tport);
961 
962 	return copied;
963 }
964 
965 static int sci_handle_fifo_overrun(struct uart_port *port)
966 {
967 	struct tty_port *tport = &port->state->port;
968 	struct sci_port *s = to_sci_port(port);
969 	const struct plat_sci_reg *reg;
970 	int copied = 0;
971 	u16 status;
972 
973 	reg = sci_getreg(port, s->params->overrun_reg);
974 	if (!reg->size)
975 		return 0;
976 
977 	status = serial_port_in(port, s->params->overrun_reg);
978 	if (status & s->params->overrun_mask) {
979 		status &= ~s->params->overrun_mask;
980 		serial_port_out(port, s->params->overrun_reg, status);
981 
982 		port->icount.overrun++;
983 
984 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
985 		tty_flip_buffer_push(tport);
986 		copied++;
987 	}
988 
989 	return copied;
990 }
991 
992 static int sci_handle_breaks(struct uart_port *port)
993 {
994 	int copied = 0;
995 	unsigned short status = serial_port_in(port, SCxSR);
996 	struct tty_port *tport = &port->state->port;
997 
998 	if (uart_handle_break(port))
999 		return 0;
1000 
1001 	if (status & SCxSR_BRK(port)) {
1002 		port->icount.brk++;
1003 
1004 		/* Notify of BREAK */
1005 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1006 			copied++;
1007 	}
1008 
1009 	if (copied)
1010 		tty_flip_buffer_push(tport);
1011 
1012 	copied += sci_handle_fifo_overrun(port);
1013 
1014 	return copied;
1015 }
1016 
1017 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1018 {
1019 	unsigned int bits;
1020 
1021 	if (rx_trig >= port->fifosize)
1022 		rx_trig = port->fifosize - 1;
1023 	if (rx_trig < 1)
1024 		rx_trig = 1;
1025 
1026 	/* HSCIF can be set to an arbitrary level. */
1027 	if (sci_getreg(port, HSRTRGR)->size) {
1028 		serial_port_out(port, HSRTRGR, rx_trig);
1029 		return rx_trig;
1030 	}
1031 
1032 	switch (port->type) {
1033 	case PORT_SCIF:
1034 		if (rx_trig < 4) {
1035 			bits = 0;
1036 			rx_trig = 1;
1037 		} else if (rx_trig < 8) {
1038 			bits = SCFCR_RTRG0;
1039 			rx_trig = 4;
1040 		} else if (rx_trig < 14) {
1041 			bits = SCFCR_RTRG1;
1042 			rx_trig = 8;
1043 		} else {
1044 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1045 			rx_trig = 14;
1046 		}
1047 		break;
1048 	case PORT_SCIFA:
1049 	case PORT_SCIFB:
1050 		if (rx_trig < 16) {
1051 			bits = 0;
1052 			rx_trig = 1;
1053 		} else if (rx_trig < 32) {
1054 			bits = SCFCR_RTRG0;
1055 			rx_trig = 16;
1056 		} else if (rx_trig < 48) {
1057 			bits = SCFCR_RTRG1;
1058 			rx_trig = 32;
1059 		} else {
1060 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1061 			rx_trig = 48;
1062 		}
1063 		break;
1064 	default:
1065 		WARN(1, "unknown FIFO configuration");
1066 		return 1;
1067 	}
1068 
1069 	serial_port_out(port, SCFCR,
1070 		(serial_port_in(port, SCFCR) &
1071 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1072 
1073 	return rx_trig;
1074 }
1075 
1076 static int scif_rtrg_enabled(struct uart_port *port)
1077 {
1078 	if (sci_getreg(port, HSRTRGR)->size)
1079 		return serial_port_in(port, HSRTRGR) != 0;
1080 	else
1081 		return (serial_port_in(port, SCFCR) &
1082 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1083 }
1084 
1085 static void rx_fifo_timer_fn(struct timer_list *t)
1086 {
1087 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1088 	struct uart_port *port = &s->port;
1089 
1090 	dev_dbg(port->dev, "Rx timed out\n");
1091 	scif_set_rtrg(port, 1);
1092 }
1093 
1094 static ssize_t rx_fifo_trigger_show(struct device *dev,
1095 				    struct device_attribute *attr, char *buf)
1096 {
1097 	struct uart_port *port = dev_get_drvdata(dev);
1098 	struct sci_port *sci = to_sci_port(port);
1099 
1100 	return sprintf(buf, "%d\n", sci->rx_trigger);
1101 }
1102 
1103 static ssize_t rx_fifo_trigger_store(struct device *dev,
1104 				     struct device_attribute *attr,
1105 				     const char *buf, size_t count)
1106 {
1107 	struct uart_port *port = dev_get_drvdata(dev);
1108 	struct sci_port *sci = to_sci_port(port);
1109 	int ret;
1110 	long r;
1111 
1112 	ret = kstrtol(buf, 0, &r);
1113 	if (ret)
1114 		return ret;
1115 
1116 	sci->rx_trigger = scif_set_rtrg(port, r);
1117 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1118 		scif_set_rtrg(port, 1);
1119 
1120 	return count;
1121 }
1122 
1123 static DEVICE_ATTR_RW(rx_fifo_trigger);
1124 
1125 static ssize_t rx_fifo_timeout_show(struct device *dev,
1126 			       struct device_attribute *attr,
1127 			       char *buf)
1128 {
1129 	struct uart_port *port = dev_get_drvdata(dev);
1130 	struct sci_port *sci = to_sci_port(port);
1131 	int v;
1132 
1133 	if (port->type == PORT_HSCIF)
1134 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1135 	else
1136 		v = sci->rx_fifo_timeout;
1137 
1138 	return sprintf(buf, "%d\n", v);
1139 }
1140 
1141 static ssize_t rx_fifo_timeout_store(struct device *dev,
1142 				struct device_attribute *attr,
1143 				const char *buf,
1144 				size_t count)
1145 {
1146 	struct uart_port *port = dev_get_drvdata(dev);
1147 	struct sci_port *sci = to_sci_port(port);
1148 	int ret;
1149 	long r;
1150 
1151 	ret = kstrtol(buf, 0, &r);
1152 	if (ret)
1153 		return ret;
1154 
1155 	if (port->type == PORT_HSCIF) {
1156 		if (r < 0 || r > 3)
1157 			return -EINVAL;
1158 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1159 	} else {
1160 		sci->rx_fifo_timeout = r;
1161 		scif_set_rtrg(port, 1);
1162 		if (r > 0)
1163 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1164 	}
1165 
1166 	return count;
1167 }
1168 
1169 static DEVICE_ATTR_RW(rx_fifo_timeout);
1170 
1171 
1172 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1173 static void sci_dma_tx_complete(void *arg)
1174 {
1175 	struct sci_port *s = arg;
1176 	struct uart_port *port = &s->port;
1177 	struct circ_buf *xmit = &port->state->xmit;
1178 	unsigned long flags;
1179 
1180 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1181 
1182 	spin_lock_irqsave(&port->lock, flags);
1183 
1184 	xmit->tail += s->tx_dma_len;
1185 	xmit->tail &= UART_XMIT_SIZE - 1;
1186 
1187 	port->icount.tx += s->tx_dma_len;
1188 
1189 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1190 		uart_write_wakeup(port);
1191 
1192 	if (!uart_circ_empty(xmit)) {
1193 		s->cookie_tx = 0;
1194 		schedule_work(&s->work_tx);
1195 	} else {
1196 		s->cookie_tx = -EINVAL;
1197 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1198 			u16 ctrl = serial_port_in(port, SCSCR);
1199 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1200 		}
1201 	}
1202 
1203 	spin_unlock_irqrestore(&port->lock, flags);
1204 }
1205 
1206 /* Locking: called with port lock held */
1207 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1208 {
1209 	struct uart_port *port = &s->port;
1210 	struct tty_port *tport = &port->state->port;
1211 	int copied;
1212 
1213 	copied = tty_insert_flip_string(tport, buf, count);
1214 	if (copied < count)
1215 		port->icount.buf_overrun++;
1216 
1217 	port->icount.rx += copied;
1218 
1219 	return copied;
1220 }
1221 
1222 static int sci_dma_rx_find_active(struct sci_port *s)
1223 {
1224 	unsigned int i;
1225 
1226 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1227 		if (s->active_rx == s->cookie_rx[i])
1228 			return i;
1229 
1230 	return -1;
1231 }
1232 
1233 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1234 {
1235 	unsigned int i;
1236 
1237 	s->chan_rx = NULL;
1238 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1239 		s->cookie_rx[i] = -EINVAL;
1240 	s->active_rx = 0;
1241 }
1242 
1243 static void sci_dma_rx_release(struct sci_port *s)
1244 {
1245 	struct dma_chan *chan = s->chan_rx_saved;
1246 
1247 	s->chan_rx_saved = NULL;
1248 	sci_dma_rx_chan_invalidate(s);
1249 	dmaengine_terminate_sync(chan);
1250 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1251 			  sg_dma_address(&s->sg_rx[0]));
1252 	dma_release_channel(chan);
1253 }
1254 
1255 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1256 {
1257 	long sec = usec / 1000000;
1258 	long nsec = (usec % 1000000) * 1000;
1259 	ktime_t t = ktime_set(sec, nsec);
1260 
1261 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1262 }
1263 
1264 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1265 {
1266 	struct uart_port *port = &s->port;
1267 	u16 scr;
1268 
1269 	/* Direct new serial port interrupts back to CPU */
1270 	scr = serial_port_in(port, SCSCR);
1271 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1272 		scr &= ~SCSCR_RDRQE;
1273 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1274 	}
1275 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1276 }
1277 
1278 static void sci_dma_rx_complete(void *arg)
1279 {
1280 	struct sci_port *s = arg;
1281 	struct dma_chan *chan = s->chan_rx;
1282 	struct uart_port *port = &s->port;
1283 	struct dma_async_tx_descriptor *desc;
1284 	unsigned long flags;
1285 	int active, count = 0;
1286 
1287 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1288 		s->active_rx);
1289 
1290 	spin_lock_irqsave(&port->lock, flags);
1291 
1292 	active = sci_dma_rx_find_active(s);
1293 	if (active >= 0)
1294 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1295 
1296 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1297 
1298 	if (count)
1299 		tty_flip_buffer_push(&port->state->port);
1300 
1301 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1302 				       DMA_DEV_TO_MEM,
1303 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1304 	if (!desc)
1305 		goto fail;
1306 
1307 	desc->callback = sci_dma_rx_complete;
1308 	desc->callback_param = s;
1309 	s->cookie_rx[active] = dmaengine_submit(desc);
1310 	if (dma_submit_error(s->cookie_rx[active]))
1311 		goto fail;
1312 
1313 	s->active_rx = s->cookie_rx[!active];
1314 
1315 	dma_async_issue_pending(chan);
1316 
1317 	spin_unlock_irqrestore(&port->lock, flags);
1318 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1319 		__func__, s->cookie_rx[active], active, s->active_rx);
1320 	return;
1321 
1322 fail:
1323 	spin_unlock_irqrestore(&port->lock, flags);
1324 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1325 	/* Switch to PIO */
1326 	spin_lock_irqsave(&port->lock, flags);
1327 	dmaengine_terminate_async(chan);
1328 	sci_dma_rx_chan_invalidate(s);
1329 	sci_dma_rx_reenable_irq(s);
1330 	spin_unlock_irqrestore(&port->lock, flags);
1331 }
1332 
1333 static void sci_dma_tx_release(struct sci_port *s)
1334 {
1335 	struct dma_chan *chan = s->chan_tx_saved;
1336 
1337 	cancel_work_sync(&s->work_tx);
1338 	s->chan_tx_saved = s->chan_tx = NULL;
1339 	s->cookie_tx = -EINVAL;
1340 	dmaengine_terminate_sync(chan);
1341 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1342 			 DMA_TO_DEVICE);
1343 	dma_release_channel(chan);
1344 }
1345 
1346 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1347 {
1348 	struct dma_chan *chan = s->chan_rx;
1349 	struct uart_port *port = &s->port;
1350 	unsigned long flags;
1351 	int i;
1352 
1353 	for (i = 0; i < 2; i++) {
1354 		struct scatterlist *sg = &s->sg_rx[i];
1355 		struct dma_async_tx_descriptor *desc;
1356 
1357 		desc = dmaengine_prep_slave_sg(chan,
1358 			sg, 1, DMA_DEV_TO_MEM,
1359 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1360 		if (!desc)
1361 			goto fail;
1362 
1363 		desc->callback = sci_dma_rx_complete;
1364 		desc->callback_param = s;
1365 		s->cookie_rx[i] = dmaengine_submit(desc);
1366 		if (dma_submit_error(s->cookie_rx[i]))
1367 			goto fail;
1368 
1369 	}
1370 
1371 	s->active_rx = s->cookie_rx[0];
1372 
1373 	dma_async_issue_pending(chan);
1374 	return 0;
1375 
1376 fail:
1377 	/* Switch to PIO */
1378 	if (!port_lock_held)
1379 		spin_lock_irqsave(&port->lock, flags);
1380 	if (i)
1381 		dmaengine_terminate_async(chan);
1382 	sci_dma_rx_chan_invalidate(s);
1383 	sci_start_rx(port);
1384 	if (!port_lock_held)
1385 		spin_unlock_irqrestore(&port->lock, flags);
1386 	return -EAGAIN;
1387 }
1388 
1389 static void sci_dma_tx_work_fn(struct work_struct *work)
1390 {
1391 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1392 	struct dma_async_tx_descriptor *desc;
1393 	struct dma_chan *chan = s->chan_tx;
1394 	struct uart_port *port = &s->port;
1395 	struct circ_buf *xmit = &port->state->xmit;
1396 	unsigned long flags;
1397 	dma_addr_t buf;
1398 	int head, tail;
1399 
1400 	/*
1401 	 * DMA is idle now.
1402 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1403 	 * offsets and lengths. Since it is a circular buffer, we have to
1404 	 * transmit till the end, and then the rest. Take the port lock to get a
1405 	 * consistent xmit buffer state.
1406 	 */
1407 	spin_lock_irq(&port->lock);
1408 	head = xmit->head;
1409 	tail = xmit->tail;
1410 	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1411 	s->tx_dma_len = min_t(unsigned int,
1412 		CIRC_CNT(head, tail, UART_XMIT_SIZE),
1413 		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1414 	if (!s->tx_dma_len) {
1415 		/* Transmit buffer has been flushed */
1416 		spin_unlock_irq(&port->lock);
1417 		return;
1418 	}
1419 
1420 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1421 					   DMA_MEM_TO_DEV,
1422 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1423 	if (!desc) {
1424 		spin_unlock_irq(&port->lock);
1425 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1426 		goto switch_to_pio;
1427 	}
1428 
1429 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1430 				   DMA_TO_DEVICE);
1431 
1432 	desc->callback = sci_dma_tx_complete;
1433 	desc->callback_param = s;
1434 	s->cookie_tx = dmaengine_submit(desc);
1435 	if (dma_submit_error(s->cookie_tx)) {
1436 		spin_unlock_irq(&port->lock);
1437 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1438 		goto switch_to_pio;
1439 	}
1440 
1441 	spin_unlock_irq(&port->lock);
1442 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1443 		__func__, xmit->buf, tail, head, s->cookie_tx);
1444 
1445 	dma_async_issue_pending(chan);
1446 	return;
1447 
1448 switch_to_pio:
1449 	spin_lock_irqsave(&port->lock, flags);
1450 	s->chan_tx = NULL;
1451 	sci_start_tx(port);
1452 	spin_unlock_irqrestore(&port->lock, flags);
1453 	return;
1454 }
1455 
1456 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1457 {
1458 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1459 	struct dma_chan *chan = s->chan_rx;
1460 	struct uart_port *port = &s->port;
1461 	struct dma_tx_state state;
1462 	enum dma_status status;
1463 	unsigned long flags;
1464 	unsigned int read;
1465 	int active, count;
1466 
1467 	dev_dbg(port->dev, "DMA Rx timed out\n");
1468 
1469 	spin_lock_irqsave(&port->lock, flags);
1470 
1471 	active = sci_dma_rx_find_active(s);
1472 	if (active < 0) {
1473 		spin_unlock_irqrestore(&port->lock, flags);
1474 		return HRTIMER_NORESTART;
1475 	}
1476 
1477 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1478 	if (status == DMA_COMPLETE) {
1479 		spin_unlock_irqrestore(&port->lock, flags);
1480 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1481 			s->active_rx, active);
1482 
1483 		/* Let packet complete handler take care of the packet */
1484 		return HRTIMER_NORESTART;
1485 	}
1486 
1487 	dmaengine_pause(chan);
1488 
1489 	/*
1490 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1491 	 * data keeps on coming until transaction is complete so check
1492 	 * for DMA_COMPLETE again
1493 	 * Let packet complete handler take care of the packet
1494 	 */
1495 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1496 	if (status == DMA_COMPLETE) {
1497 		spin_unlock_irqrestore(&port->lock, flags);
1498 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1499 		return HRTIMER_NORESTART;
1500 	}
1501 
1502 	/* Handle incomplete DMA receive */
1503 	dmaengine_terminate_async(s->chan_rx);
1504 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1505 
1506 	if (read) {
1507 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1508 		if (count)
1509 			tty_flip_buffer_push(&port->state->port);
1510 	}
1511 
1512 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1513 		sci_dma_rx_submit(s, true);
1514 
1515 	sci_dma_rx_reenable_irq(s);
1516 
1517 	spin_unlock_irqrestore(&port->lock, flags);
1518 
1519 	return HRTIMER_NORESTART;
1520 }
1521 
1522 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1523 					     enum dma_transfer_direction dir)
1524 {
1525 	struct dma_chan *chan;
1526 	struct dma_slave_config cfg;
1527 	int ret;
1528 
1529 	chan = dma_request_slave_channel(port->dev,
1530 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1531 	if (!chan) {
1532 		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1533 		return NULL;
1534 	}
1535 
1536 	memset(&cfg, 0, sizeof(cfg));
1537 	cfg.direction = dir;
1538 	if (dir == DMA_MEM_TO_DEV) {
1539 		cfg.dst_addr = port->mapbase +
1540 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1541 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1542 	} else {
1543 		cfg.src_addr = port->mapbase +
1544 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1545 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1546 	}
1547 
1548 	ret = dmaengine_slave_config(chan, &cfg);
1549 	if (ret) {
1550 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1551 		dma_release_channel(chan);
1552 		return NULL;
1553 	}
1554 
1555 	return chan;
1556 }
1557 
1558 static void sci_request_dma(struct uart_port *port)
1559 {
1560 	struct sci_port *s = to_sci_port(port);
1561 	struct dma_chan *chan;
1562 
1563 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1564 
1565 	/*
1566 	 * DMA on console may interfere with Kernel log messages which use
1567 	 * plain putchar(). So, simply don't use it with a console.
1568 	 */
1569 	if (uart_console(port))
1570 		return;
1571 
1572 	if (!port->dev->of_node)
1573 		return;
1574 
1575 	s->cookie_tx = -EINVAL;
1576 
1577 	/*
1578 	 * Don't request a dma channel if no channel was specified
1579 	 * in the device tree.
1580 	 */
1581 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1582 		return;
1583 
1584 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1585 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1586 	if (chan) {
1587 		/* UART circular tx buffer is an aligned page. */
1588 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1589 						port->state->xmit.buf,
1590 						UART_XMIT_SIZE,
1591 						DMA_TO_DEVICE);
1592 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1593 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1594 			dma_release_channel(chan);
1595 		} else {
1596 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1597 				__func__, UART_XMIT_SIZE,
1598 				port->state->xmit.buf, &s->tx_dma_addr);
1599 
1600 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1601 			s->chan_tx_saved = s->chan_tx = chan;
1602 		}
1603 	}
1604 
1605 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1606 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1607 	if (chan) {
1608 		unsigned int i;
1609 		dma_addr_t dma;
1610 		void *buf;
1611 
1612 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1613 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1614 					 &dma, GFP_KERNEL);
1615 		if (!buf) {
1616 			dev_warn(port->dev,
1617 				 "Failed to allocate Rx dma buffer, using PIO\n");
1618 			dma_release_channel(chan);
1619 			return;
1620 		}
1621 
1622 		for (i = 0; i < 2; i++) {
1623 			struct scatterlist *sg = &s->sg_rx[i];
1624 
1625 			sg_init_table(sg, 1);
1626 			s->rx_buf[i] = buf;
1627 			sg_dma_address(sg) = dma;
1628 			sg_dma_len(sg) = s->buf_len_rx;
1629 
1630 			buf += s->buf_len_rx;
1631 			dma += s->buf_len_rx;
1632 		}
1633 
1634 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1635 		s->rx_timer.function = sci_dma_rx_timer_fn;
1636 
1637 		s->chan_rx_saved = s->chan_rx = chan;
1638 
1639 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1640 			sci_dma_rx_submit(s, false);
1641 	}
1642 }
1643 
1644 static void sci_free_dma(struct uart_port *port)
1645 {
1646 	struct sci_port *s = to_sci_port(port);
1647 
1648 	if (s->chan_tx_saved)
1649 		sci_dma_tx_release(s);
1650 	if (s->chan_rx_saved)
1651 		sci_dma_rx_release(s);
1652 }
1653 
1654 static void sci_flush_buffer(struct uart_port *port)
1655 {
1656 	struct sci_port *s = to_sci_port(port);
1657 
1658 	/*
1659 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1660 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1661 	 * pending transfers
1662 	 */
1663 	s->tx_dma_len = 0;
1664 	if (s->chan_tx) {
1665 		dmaengine_terminate_async(s->chan_tx);
1666 		s->cookie_tx = -EINVAL;
1667 	}
1668 }
1669 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1670 static inline void sci_request_dma(struct uart_port *port)
1671 {
1672 }
1673 
1674 static inline void sci_free_dma(struct uart_port *port)
1675 {
1676 }
1677 
1678 #define sci_flush_buffer	NULL
1679 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1680 
1681 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1682 {
1683 	struct uart_port *port = ptr;
1684 	struct sci_port *s = to_sci_port(port);
1685 
1686 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1687 	if (s->chan_rx) {
1688 		u16 scr = serial_port_in(port, SCSCR);
1689 		u16 ssr = serial_port_in(port, SCxSR);
1690 
1691 		/* Disable future Rx interrupts */
1692 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1693 			disable_irq_nosync(irq);
1694 			scr |= SCSCR_RDRQE;
1695 		} else {
1696 			if (sci_dma_rx_submit(s, false) < 0)
1697 				goto handle_pio;
1698 
1699 			scr &= ~SCSCR_RIE;
1700 		}
1701 		serial_port_out(port, SCSCR, scr);
1702 		/* Clear current interrupt */
1703 		serial_port_out(port, SCxSR,
1704 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1705 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1706 			jiffies, s->rx_timeout);
1707 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1708 
1709 		return IRQ_HANDLED;
1710 	}
1711 
1712 handle_pio:
1713 #endif
1714 
1715 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1716 		if (!scif_rtrg_enabled(port))
1717 			scif_set_rtrg(port, s->rx_trigger);
1718 
1719 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1720 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1721 	}
1722 
1723 	/* I think sci_receive_chars has to be called irrespective
1724 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1725 	 * to be disabled?
1726 	 */
1727 	sci_receive_chars(port);
1728 
1729 	return IRQ_HANDLED;
1730 }
1731 
1732 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1733 {
1734 	struct uart_port *port = ptr;
1735 	unsigned long flags;
1736 
1737 	spin_lock_irqsave(&port->lock, flags);
1738 	sci_transmit_chars(port);
1739 	spin_unlock_irqrestore(&port->lock, flags);
1740 
1741 	return IRQ_HANDLED;
1742 }
1743 
1744 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1745 {
1746 	struct uart_port *port = ptr;
1747 
1748 	/* Handle BREAKs */
1749 	sci_handle_breaks(port);
1750 
1751 	/* drop invalid character received before break was detected */
1752 	serial_port_in(port, SCxRDR);
1753 
1754 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1755 
1756 	return IRQ_HANDLED;
1757 }
1758 
1759 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1760 {
1761 	struct uart_port *port = ptr;
1762 	struct sci_port *s = to_sci_port(port);
1763 
1764 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1765 		/* Break and Error interrupts are muxed */
1766 		unsigned short ssr_status = serial_port_in(port, SCxSR);
1767 
1768 		/* Break Interrupt */
1769 		if (ssr_status & SCxSR_BRK(port))
1770 			sci_br_interrupt(irq, ptr);
1771 
1772 		/* Break only? */
1773 		if (!(ssr_status & SCxSR_ERRORS(port)))
1774 			return IRQ_HANDLED;
1775 	}
1776 
1777 	/* Handle errors */
1778 	if (port->type == PORT_SCI) {
1779 		if (sci_handle_errors(port)) {
1780 			/* discard character in rx buffer */
1781 			serial_port_in(port, SCxSR);
1782 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1783 		}
1784 	} else {
1785 		sci_handle_fifo_overrun(port);
1786 		if (!s->chan_rx)
1787 			sci_receive_chars(port);
1788 	}
1789 
1790 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1791 
1792 	/* Kick the transmission */
1793 	if (!s->chan_tx)
1794 		sci_tx_interrupt(irq, ptr);
1795 
1796 	return IRQ_HANDLED;
1797 }
1798 
1799 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1800 {
1801 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1802 	struct uart_port *port = ptr;
1803 	struct sci_port *s = to_sci_port(port);
1804 	irqreturn_t ret = IRQ_NONE;
1805 
1806 	ssr_status = serial_port_in(port, SCxSR);
1807 	scr_status = serial_port_in(port, SCSCR);
1808 	if (s->params->overrun_reg == SCxSR)
1809 		orer_status = ssr_status;
1810 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1811 		orer_status = serial_port_in(port, s->params->overrun_reg);
1812 
1813 	err_enabled = scr_status & port_rx_irq_mask(port);
1814 
1815 	/* Tx Interrupt */
1816 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1817 	    !s->chan_tx)
1818 		ret = sci_tx_interrupt(irq, ptr);
1819 
1820 	/*
1821 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1822 	 * DR flags
1823 	 */
1824 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1825 	    (scr_status & SCSCR_RIE))
1826 		ret = sci_rx_interrupt(irq, ptr);
1827 
1828 	/* Error Interrupt */
1829 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1830 		ret = sci_er_interrupt(irq, ptr);
1831 
1832 	/* Break Interrupt */
1833 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1834 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1835 		ret = sci_br_interrupt(irq, ptr);
1836 
1837 	/* Overrun Interrupt */
1838 	if (orer_status & s->params->overrun_mask) {
1839 		sci_handle_fifo_overrun(port);
1840 		ret = IRQ_HANDLED;
1841 	}
1842 
1843 	return ret;
1844 }
1845 
1846 static const struct sci_irq_desc {
1847 	const char	*desc;
1848 	irq_handler_t	handler;
1849 } sci_irq_desc[] = {
1850 	/*
1851 	 * Split out handlers, the default case.
1852 	 */
1853 	[SCIx_ERI_IRQ] = {
1854 		.desc = "rx err",
1855 		.handler = sci_er_interrupt,
1856 	},
1857 
1858 	[SCIx_RXI_IRQ] = {
1859 		.desc = "rx full",
1860 		.handler = sci_rx_interrupt,
1861 	},
1862 
1863 	[SCIx_TXI_IRQ] = {
1864 		.desc = "tx empty",
1865 		.handler = sci_tx_interrupt,
1866 	},
1867 
1868 	[SCIx_BRI_IRQ] = {
1869 		.desc = "break",
1870 		.handler = sci_br_interrupt,
1871 	},
1872 
1873 	[SCIx_DRI_IRQ] = {
1874 		.desc = "rx ready",
1875 		.handler = sci_rx_interrupt,
1876 	},
1877 
1878 	[SCIx_TEI_IRQ] = {
1879 		.desc = "tx end",
1880 		.handler = sci_tx_interrupt,
1881 	},
1882 
1883 	/*
1884 	 * Special muxed handler.
1885 	 */
1886 	[SCIx_MUX_IRQ] = {
1887 		.desc = "mux",
1888 		.handler = sci_mpxed_interrupt,
1889 	},
1890 };
1891 
1892 static int sci_request_irq(struct sci_port *port)
1893 {
1894 	struct uart_port *up = &port->port;
1895 	int i, j, w, ret = 0;
1896 
1897 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1898 		const struct sci_irq_desc *desc;
1899 		int irq;
1900 
1901 		/* Check if already registered (muxed) */
1902 		for (w = 0; w < i; w++)
1903 			if (port->irqs[w] == port->irqs[i])
1904 				w = i + 1;
1905 		if (w > i)
1906 			continue;
1907 
1908 		if (SCIx_IRQ_IS_MUXED(port)) {
1909 			i = SCIx_MUX_IRQ;
1910 			irq = up->irq;
1911 		} else {
1912 			irq = port->irqs[i];
1913 
1914 			/*
1915 			 * Certain port types won't support all of the
1916 			 * available interrupt sources.
1917 			 */
1918 			if (unlikely(irq < 0))
1919 				continue;
1920 		}
1921 
1922 		desc = sci_irq_desc + i;
1923 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1924 					    dev_name(up->dev), desc->desc);
1925 		if (!port->irqstr[j]) {
1926 			ret = -ENOMEM;
1927 			goto out_nomem;
1928 		}
1929 
1930 		ret = request_irq(irq, desc->handler, up->irqflags,
1931 				  port->irqstr[j], port);
1932 		if (unlikely(ret)) {
1933 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1934 			goto out_noirq;
1935 		}
1936 	}
1937 
1938 	return 0;
1939 
1940 out_noirq:
1941 	while (--i >= 0)
1942 		free_irq(port->irqs[i], port);
1943 
1944 out_nomem:
1945 	while (--j >= 0)
1946 		kfree(port->irqstr[j]);
1947 
1948 	return ret;
1949 }
1950 
1951 static void sci_free_irq(struct sci_port *port)
1952 {
1953 	int i, j;
1954 
1955 	/*
1956 	 * Intentionally in reverse order so we iterate over the muxed
1957 	 * IRQ first.
1958 	 */
1959 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1960 		int irq = port->irqs[i];
1961 
1962 		/*
1963 		 * Certain port types won't support all of the available
1964 		 * interrupt sources.
1965 		 */
1966 		if (unlikely(irq < 0))
1967 			continue;
1968 
1969 		/* Check if already freed (irq was muxed) */
1970 		for (j = 0; j < i; j++)
1971 			if (port->irqs[j] == irq)
1972 				j = i + 1;
1973 		if (j > i)
1974 			continue;
1975 
1976 		free_irq(port->irqs[i], port);
1977 		kfree(port->irqstr[i]);
1978 
1979 		if (SCIx_IRQ_IS_MUXED(port)) {
1980 			/* If there's only one IRQ, we're done. */
1981 			return;
1982 		}
1983 	}
1984 }
1985 
1986 static unsigned int sci_tx_empty(struct uart_port *port)
1987 {
1988 	unsigned short status = serial_port_in(port, SCxSR);
1989 	unsigned short in_tx_fifo = sci_txfill(port);
1990 
1991 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1992 }
1993 
1994 static void sci_set_rts(struct uart_port *port, bool state)
1995 {
1996 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1997 		u16 data = serial_port_in(port, SCPDR);
1998 
1999 		/* Active low */
2000 		if (state)
2001 			data &= ~SCPDR_RTSD;
2002 		else
2003 			data |= SCPDR_RTSD;
2004 		serial_port_out(port, SCPDR, data);
2005 
2006 		/* RTS# is output */
2007 		serial_port_out(port, SCPCR,
2008 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2009 	} else if (sci_getreg(port, SCSPTR)->size) {
2010 		u16 ctrl = serial_port_in(port, SCSPTR);
2011 
2012 		/* Active low */
2013 		if (state)
2014 			ctrl &= ~SCSPTR_RTSDT;
2015 		else
2016 			ctrl |= SCSPTR_RTSDT;
2017 		serial_port_out(port, SCSPTR, ctrl);
2018 	}
2019 }
2020 
2021 static bool sci_get_cts(struct uart_port *port)
2022 {
2023 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2024 		/* Active low */
2025 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2026 	} else if (sci_getreg(port, SCSPTR)->size) {
2027 		/* Active low */
2028 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2029 	}
2030 
2031 	return true;
2032 }
2033 
2034 /*
2035  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2036  * CTS/RTS is supported in hardware by at least one port and controlled
2037  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2038  * handled via the ->init_pins() op, which is a bit of a one-way street,
2039  * lacking any ability to defer pin control -- this will later be
2040  * converted over to the GPIO framework).
2041  *
2042  * Other modes (such as loopback) are supported generically on certain
2043  * port types, but not others. For these it's sufficient to test for the
2044  * existence of the support register and simply ignore the port type.
2045  */
2046 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2047 {
2048 	struct sci_port *s = to_sci_port(port);
2049 
2050 	if (mctrl & TIOCM_LOOP) {
2051 		const struct plat_sci_reg *reg;
2052 
2053 		/*
2054 		 * Standard loopback mode for SCFCR ports.
2055 		 */
2056 		reg = sci_getreg(port, SCFCR);
2057 		if (reg->size)
2058 			serial_port_out(port, SCFCR,
2059 					serial_port_in(port, SCFCR) |
2060 					SCFCR_LOOP);
2061 	}
2062 
2063 	mctrl_gpio_set(s->gpios, mctrl);
2064 
2065 	if (!s->has_rtscts)
2066 		return;
2067 
2068 	if (!(mctrl & TIOCM_RTS)) {
2069 		/* Disable Auto RTS */
2070 		serial_port_out(port, SCFCR,
2071 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2072 
2073 		/* Clear RTS */
2074 		sci_set_rts(port, 0);
2075 	} else if (s->autorts) {
2076 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2077 			/* Enable RTS# pin function */
2078 			serial_port_out(port, SCPCR,
2079 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2080 		}
2081 
2082 		/* Enable Auto RTS */
2083 		serial_port_out(port, SCFCR,
2084 				serial_port_in(port, SCFCR) | SCFCR_MCE);
2085 	} else {
2086 		/* Set RTS */
2087 		sci_set_rts(port, 1);
2088 	}
2089 }
2090 
2091 static unsigned int sci_get_mctrl(struct uart_port *port)
2092 {
2093 	struct sci_port *s = to_sci_port(port);
2094 	struct mctrl_gpios *gpios = s->gpios;
2095 	unsigned int mctrl = 0;
2096 
2097 	mctrl_gpio_get(gpios, &mctrl);
2098 
2099 	/*
2100 	 * CTS/RTS is handled in hardware when supported, while nothing
2101 	 * else is wired up.
2102 	 */
2103 	if (s->autorts) {
2104 		if (sci_get_cts(port))
2105 			mctrl |= TIOCM_CTS;
2106 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2107 		mctrl |= TIOCM_CTS;
2108 	}
2109 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2110 		mctrl |= TIOCM_DSR;
2111 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2112 		mctrl |= TIOCM_CAR;
2113 
2114 	return mctrl;
2115 }
2116 
2117 static void sci_enable_ms(struct uart_port *port)
2118 {
2119 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2120 }
2121 
2122 static void sci_break_ctl(struct uart_port *port, int break_state)
2123 {
2124 	unsigned short scscr, scsptr;
2125 	unsigned long flags;
2126 
2127 	/* check whether the port has SCSPTR */
2128 	if (!sci_getreg(port, SCSPTR)->size) {
2129 		/*
2130 		 * Not supported by hardware. Most parts couple break and rx
2131 		 * interrupts together, with break detection always enabled.
2132 		 */
2133 		return;
2134 	}
2135 
2136 	spin_lock_irqsave(&port->lock, flags);
2137 	scsptr = serial_port_in(port, SCSPTR);
2138 	scscr = serial_port_in(port, SCSCR);
2139 
2140 	if (break_state == -1) {
2141 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2142 		scscr &= ~SCSCR_TE;
2143 	} else {
2144 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2145 		scscr |= SCSCR_TE;
2146 	}
2147 
2148 	serial_port_out(port, SCSPTR, scsptr);
2149 	serial_port_out(port, SCSCR, scscr);
2150 	spin_unlock_irqrestore(&port->lock, flags);
2151 }
2152 
2153 static int sci_startup(struct uart_port *port)
2154 {
2155 	struct sci_port *s = to_sci_port(port);
2156 	int ret;
2157 
2158 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2159 
2160 	sci_request_dma(port);
2161 
2162 	ret = sci_request_irq(s);
2163 	if (unlikely(ret < 0)) {
2164 		sci_free_dma(port);
2165 		return ret;
2166 	}
2167 
2168 	return 0;
2169 }
2170 
2171 static void sci_shutdown(struct uart_port *port)
2172 {
2173 	struct sci_port *s = to_sci_port(port);
2174 	unsigned long flags;
2175 	u16 scr;
2176 
2177 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2178 
2179 	s->autorts = false;
2180 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2181 
2182 	spin_lock_irqsave(&port->lock, flags);
2183 	sci_stop_rx(port);
2184 	sci_stop_tx(port);
2185 	/*
2186 	 * Stop RX and TX, disable related interrupts, keep clock source
2187 	 * and HSCIF TOT bits
2188 	 */
2189 	scr = serial_port_in(port, SCSCR);
2190 	serial_port_out(port, SCSCR, scr &
2191 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2192 	spin_unlock_irqrestore(&port->lock, flags);
2193 
2194 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2195 	if (s->chan_rx_saved) {
2196 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2197 			port->line);
2198 		hrtimer_cancel(&s->rx_timer);
2199 	}
2200 #endif
2201 
2202 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2203 		del_timer_sync(&s->rx_fifo_timer);
2204 	sci_free_irq(s);
2205 	sci_free_dma(port);
2206 }
2207 
2208 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2209 			unsigned int *srr)
2210 {
2211 	unsigned long freq = s->clk_rates[SCI_SCK];
2212 	int err, min_err = INT_MAX;
2213 	unsigned int sr;
2214 
2215 	if (s->port.type != PORT_HSCIF)
2216 		freq *= 2;
2217 
2218 	for_each_sr(sr, s) {
2219 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2220 		if (abs(err) >= abs(min_err))
2221 			continue;
2222 
2223 		min_err = err;
2224 		*srr = sr - 1;
2225 
2226 		if (!err)
2227 			break;
2228 	}
2229 
2230 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2231 		*srr + 1);
2232 	return min_err;
2233 }
2234 
2235 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2236 			unsigned long freq, unsigned int *dlr,
2237 			unsigned int *srr)
2238 {
2239 	int err, min_err = INT_MAX;
2240 	unsigned int sr, dl;
2241 
2242 	if (s->port.type != PORT_HSCIF)
2243 		freq *= 2;
2244 
2245 	for_each_sr(sr, s) {
2246 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2247 		dl = clamp(dl, 1U, 65535U);
2248 
2249 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2250 		if (abs(err) >= abs(min_err))
2251 			continue;
2252 
2253 		min_err = err;
2254 		*dlr = dl;
2255 		*srr = sr - 1;
2256 
2257 		if (!err)
2258 			break;
2259 	}
2260 
2261 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2262 		min_err, *dlr, *srr + 1);
2263 	return min_err;
2264 }
2265 
2266 /* calculate sample rate, BRR, and clock select */
2267 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2268 			  unsigned int *brr, unsigned int *srr,
2269 			  unsigned int *cks)
2270 {
2271 	unsigned long freq = s->clk_rates[SCI_FCK];
2272 	unsigned int sr, br, prediv, scrate, c;
2273 	int err, min_err = INT_MAX;
2274 
2275 	if (s->port.type != PORT_HSCIF)
2276 		freq *= 2;
2277 
2278 	/*
2279 	 * Find the combination of sample rate and clock select with the
2280 	 * smallest deviation from the desired baud rate.
2281 	 * Prefer high sample rates to maximise the receive margin.
2282 	 *
2283 	 * M: Receive margin (%)
2284 	 * N: Ratio of bit rate to clock (N = sampling rate)
2285 	 * D: Clock duty (D = 0 to 1.0)
2286 	 * L: Frame length (L = 9 to 12)
2287 	 * F: Absolute value of clock frequency deviation
2288 	 *
2289 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2290 	 *      (|D - 0.5| / N * (1 + F))|
2291 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2292 	 */
2293 	for_each_sr(sr, s) {
2294 		for (c = 0; c <= 3; c++) {
2295 			/* integerized formulas from HSCIF documentation */
2296 			prediv = sr << (2 * c + 1);
2297 
2298 			/*
2299 			 * We need to calculate:
2300 			 *
2301 			 *     br = freq / (prediv * bps) clamped to [1..256]
2302 			 *     err = freq / (br * prediv) - bps
2303 			 *
2304 			 * Watch out for overflow when calculating the desired
2305 			 * sampling clock rate!
2306 			 */
2307 			if (bps > UINT_MAX / prediv)
2308 				break;
2309 
2310 			scrate = prediv * bps;
2311 			br = DIV_ROUND_CLOSEST(freq, scrate);
2312 			br = clamp(br, 1U, 256U);
2313 
2314 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2315 			if (abs(err) >= abs(min_err))
2316 				continue;
2317 
2318 			min_err = err;
2319 			*brr = br - 1;
2320 			*srr = sr - 1;
2321 			*cks = c;
2322 
2323 			if (!err)
2324 				goto found;
2325 		}
2326 	}
2327 
2328 found:
2329 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2330 		min_err, *brr, *srr + 1, *cks);
2331 	return min_err;
2332 }
2333 
2334 static void sci_reset(struct uart_port *port)
2335 {
2336 	const struct plat_sci_reg *reg;
2337 	unsigned int status;
2338 	struct sci_port *s = to_sci_port(port);
2339 
2340 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2341 
2342 	reg = sci_getreg(port, SCFCR);
2343 	if (reg->size)
2344 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2345 
2346 	sci_clear_SCxSR(port,
2347 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2348 			SCxSR_BREAK_CLEAR(port));
2349 	if (sci_getreg(port, SCLSR)->size) {
2350 		status = serial_port_in(port, SCLSR);
2351 		status &= ~(SCLSR_TO | SCLSR_ORER);
2352 		serial_port_out(port, SCLSR, status);
2353 	}
2354 
2355 	if (s->rx_trigger > 1) {
2356 		if (s->rx_fifo_timeout) {
2357 			scif_set_rtrg(port, 1);
2358 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2359 		} else {
2360 			if (port->type == PORT_SCIFA ||
2361 			    port->type == PORT_SCIFB)
2362 				scif_set_rtrg(port, 1);
2363 			else
2364 				scif_set_rtrg(port, s->rx_trigger);
2365 		}
2366 	}
2367 }
2368 
2369 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2370 			    struct ktermios *old)
2371 {
2372 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2373 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2374 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2375 	struct sci_port *s = to_sci_port(port);
2376 	const struct plat_sci_reg *reg;
2377 	int min_err = INT_MAX, err;
2378 	unsigned long max_freq = 0;
2379 	int best_clk = -1;
2380 	unsigned long flags;
2381 
2382 	if ((termios->c_cflag & CSIZE) == CS7)
2383 		smr_val |= SCSMR_CHR;
2384 	if (termios->c_cflag & PARENB)
2385 		smr_val |= SCSMR_PE;
2386 	if (termios->c_cflag & PARODD)
2387 		smr_val |= SCSMR_PE | SCSMR_ODD;
2388 	if (termios->c_cflag & CSTOPB)
2389 		smr_val |= SCSMR_STOP;
2390 
2391 	/*
2392 	 * earlyprintk comes here early on with port->uartclk set to zero.
2393 	 * the clock framework is not up and running at this point so here
2394 	 * we assume that 115200 is the maximum baud rate. please note that
2395 	 * the baud rate is not programmed during earlyprintk - it is assumed
2396 	 * that the previous boot loader has enabled required clocks and
2397 	 * setup the baud rate generator hardware for us already.
2398 	 */
2399 	if (!port->uartclk) {
2400 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2401 		goto done;
2402 	}
2403 
2404 	for (i = 0; i < SCI_NUM_CLKS; i++)
2405 		max_freq = max(max_freq, s->clk_rates[i]);
2406 
2407 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2408 	if (!baud)
2409 		goto done;
2410 
2411 	/*
2412 	 * There can be multiple sources for the sampling clock.  Find the one
2413 	 * that gives us the smallest deviation from the desired baud rate.
2414 	 */
2415 
2416 	/* Optional Undivided External Clock */
2417 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2418 	    port->type != PORT_SCIFB) {
2419 		err = sci_sck_calc(s, baud, &srr1);
2420 		if (abs(err) < abs(min_err)) {
2421 			best_clk = SCI_SCK;
2422 			scr_val = SCSCR_CKE1;
2423 			sccks = SCCKS_CKS;
2424 			min_err = err;
2425 			srr = srr1;
2426 			if (!err)
2427 				goto done;
2428 		}
2429 	}
2430 
2431 	/* Optional BRG Frequency Divided External Clock */
2432 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2433 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2434 				   &srr1);
2435 		if (abs(err) < abs(min_err)) {
2436 			best_clk = SCI_SCIF_CLK;
2437 			scr_val = SCSCR_CKE1;
2438 			sccks = 0;
2439 			min_err = err;
2440 			dl = dl1;
2441 			srr = srr1;
2442 			if (!err)
2443 				goto done;
2444 		}
2445 	}
2446 
2447 	/* Optional BRG Frequency Divided Internal Clock */
2448 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2449 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2450 				   &srr1);
2451 		if (abs(err) < abs(min_err)) {
2452 			best_clk = SCI_BRG_INT;
2453 			scr_val = SCSCR_CKE1;
2454 			sccks = SCCKS_XIN;
2455 			min_err = err;
2456 			dl = dl1;
2457 			srr = srr1;
2458 			if (!min_err)
2459 				goto done;
2460 		}
2461 	}
2462 
2463 	/* Divided Functional Clock using standard Bit Rate Register */
2464 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2465 	if (abs(err) < abs(min_err)) {
2466 		best_clk = SCI_FCK;
2467 		scr_val = 0;
2468 		min_err = err;
2469 		brr = brr1;
2470 		srr = srr1;
2471 		cks = cks1;
2472 	}
2473 
2474 done:
2475 	if (best_clk >= 0)
2476 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2477 			s->clks[best_clk], baud, min_err);
2478 
2479 	sci_port_enable(s);
2480 
2481 	/*
2482 	 * Program the optional External Baud Rate Generator (BRG) first.
2483 	 * It controls the mux to select (H)SCK or frequency divided clock.
2484 	 */
2485 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2486 		serial_port_out(port, SCDL, dl);
2487 		serial_port_out(port, SCCKS, sccks);
2488 	}
2489 
2490 	spin_lock_irqsave(&port->lock, flags);
2491 
2492 	sci_reset(port);
2493 
2494 	uart_update_timeout(port, termios->c_cflag, baud);
2495 
2496 	/* byte size and parity */
2497 	bits = tty_get_frame_size(termios->c_cflag);
2498 
2499 	if (sci_getreg(port, SEMR)->size)
2500 		serial_port_out(port, SEMR, 0);
2501 
2502 	if (best_clk >= 0) {
2503 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2504 			switch (srr + 1) {
2505 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2506 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2507 			case 11: smr_val |= SCSMR_SRC_11; break;
2508 			case 13: smr_val |= SCSMR_SRC_13; break;
2509 			case 16: smr_val |= SCSMR_SRC_16; break;
2510 			case 17: smr_val |= SCSMR_SRC_17; break;
2511 			case 19: smr_val |= SCSMR_SRC_19; break;
2512 			case 27: smr_val |= SCSMR_SRC_27; break;
2513 			}
2514 		smr_val |= cks;
2515 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2516 		serial_port_out(port, SCSMR, smr_val);
2517 		serial_port_out(port, SCBRR, brr);
2518 		if (sci_getreg(port, HSSRR)->size) {
2519 			unsigned int hssrr = srr | HSCIF_SRE;
2520 			/* Calculate deviation from intended rate at the
2521 			 * center of the last stop bit in sampling clocks.
2522 			 */
2523 			int last_stop = bits * 2 - 1;
2524 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2525 							  (int)(srr + 1),
2526 							  2 * (int)baud);
2527 
2528 			if (abs(deviation) >= 2) {
2529 				/* At least two sampling clocks off at the
2530 				 * last stop bit; we can increase the error
2531 				 * margin by shifting the sampling point.
2532 				 */
2533 				int shift = clamp(deviation / 2, -8, 7);
2534 
2535 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2536 					 HSCIF_SRHP_MASK;
2537 				hssrr |= HSCIF_SRDE;
2538 			}
2539 			serial_port_out(port, HSSRR, hssrr);
2540 		}
2541 
2542 		/* Wait one bit interval */
2543 		udelay((1000000 + (baud - 1)) / baud);
2544 	} else {
2545 		/* Don't touch the bit rate configuration */
2546 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2547 		smr_val |= serial_port_in(port, SCSMR) &
2548 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2549 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2550 		serial_port_out(port, SCSMR, smr_val);
2551 	}
2552 
2553 	sci_init_pins(port, termios->c_cflag);
2554 
2555 	port->status &= ~UPSTAT_AUTOCTS;
2556 	s->autorts = false;
2557 	reg = sci_getreg(port, SCFCR);
2558 	if (reg->size) {
2559 		unsigned short ctrl = serial_port_in(port, SCFCR);
2560 
2561 		if ((port->flags & UPF_HARD_FLOW) &&
2562 		    (termios->c_cflag & CRTSCTS)) {
2563 			/* There is no CTS interrupt to restart the hardware */
2564 			port->status |= UPSTAT_AUTOCTS;
2565 			/* MCE is enabled when RTS is raised */
2566 			s->autorts = true;
2567 		}
2568 
2569 		/*
2570 		 * As we've done a sci_reset() above, ensure we don't
2571 		 * interfere with the FIFOs while toggling MCE. As the
2572 		 * reset values could still be set, simply mask them out.
2573 		 */
2574 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2575 
2576 		serial_port_out(port, SCFCR, ctrl);
2577 	}
2578 	if (port->flags & UPF_HARD_FLOW) {
2579 		/* Refresh (Auto) RTS */
2580 		sci_set_mctrl(port, port->mctrl);
2581 	}
2582 
2583 	scr_val |= SCSCR_RE | SCSCR_TE |
2584 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2585 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2586 	if ((srr + 1 == 5) &&
2587 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2588 		/*
2589 		 * In asynchronous mode, when the sampling rate is 1/5, first
2590 		 * received data may become invalid on some SCIFA and SCIFB.
2591 		 * To avoid this problem wait more than 1 serial data time (1
2592 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2593 		 */
2594 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2595 	}
2596 
2597 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2598 	s->rx_frame = (10000 * bits) / (baud / 100);
2599 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2600 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2601 #endif
2602 
2603 	if ((termios->c_cflag & CREAD) != 0)
2604 		sci_start_rx(port);
2605 
2606 	spin_unlock_irqrestore(&port->lock, flags);
2607 
2608 	sci_port_disable(s);
2609 
2610 	if (UART_ENABLE_MS(port, termios->c_cflag))
2611 		sci_enable_ms(port);
2612 }
2613 
2614 static void sci_pm(struct uart_port *port, unsigned int state,
2615 		   unsigned int oldstate)
2616 {
2617 	struct sci_port *sci_port = to_sci_port(port);
2618 
2619 	switch (state) {
2620 	case UART_PM_STATE_OFF:
2621 		sci_port_disable(sci_port);
2622 		break;
2623 	default:
2624 		sci_port_enable(sci_port);
2625 		break;
2626 	}
2627 }
2628 
2629 static const char *sci_type(struct uart_port *port)
2630 {
2631 	switch (port->type) {
2632 	case PORT_IRDA:
2633 		return "irda";
2634 	case PORT_SCI:
2635 		return "sci";
2636 	case PORT_SCIF:
2637 		return "scif";
2638 	case PORT_SCIFA:
2639 		return "scifa";
2640 	case PORT_SCIFB:
2641 		return "scifb";
2642 	case PORT_HSCIF:
2643 		return "hscif";
2644 	}
2645 
2646 	return NULL;
2647 }
2648 
2649 static int sci_remap_port(struct uart_port *port)
2650 {
2651 	struct sci_port *sport = to_sci_port(port);
2652 
2653 	/*
2654 	 * Nothing to do if there's already an established membase.
2655 	 */
2656 	if (port->membase)
2657 		return 0;
2658 
2659 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2660 		port->membase = ioremap(port->mapbase, sport->reg_size);
2661 		if (unlikely(!port->membase)) {
2662 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2663 			return -ENXIO;
2664 		}
2665 	} else {
2666 		/*
2667 		 * For the simple (and majority of) cases where we don't
2668 		 * need to do any remapping, just cast the cookie
2669 		 * directly.
2670 		 */
2671 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2672 	}
2673 
2674 	return 0;
2675 }
2676 
2677 static void sci_release_port(struct uart_port *port)
2678 {
2679 	struct sci_port *sport = to_sci_port(port);
2680 
2681 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2682 		iounmap(port->membase);
2683 		port->membase = NULL;
2684 	}
2685 
2686 	release_mem_region(port->mapbase, sport->reg_size);
2687 }
2688 
2689 static int sci_request_port(struct uart_port *port)
2690 {
2691 	struct resource *res;
2692 	struct sci_port *sport = to_sci_port(port);
2693 	int ret;
2694 
2695 	res = request_mem_region(port->mapbase, sport->reg_size,
2696 				 dev_name(port->dev));
2697 	if (unlikely(res == NULL)) {
2698 		dev_err(port->dev, "request_mem_region failed.");
2699 		return -EBUSY;
2700 	}
2701 
2702 	ret = sci_remap_port(port);
2703 	if (unlikely(ret != 0)) {
2704 		release_resource(res);
2705 		return ret;
2706 	}
2707 
2708 	return 0;
2709 }
2710 
2711 static void sci_config_port(struct uart_port *port, int flags)
2712 {
2713 	if (flags & UART_CONFIG_TYPE) {
2714 		struct sci_port *sport = to_sci_port(port);
2715 
2716 		port->type = sport->cfg->type;
2717 		sci_request_port(port);
2718 	}
2719 }
2720 
2721 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2722 {
2723 	if (ser->baud_base < 2400)
2724 		/* No paper tape reader for Mitch.. */
2725 		return -EINVAL;
2726 
2727 	return 0;
2728 }
2729 
2730 static const struct uart_ops sci_uart_ops = {
2731 	.tx_empty	= sci_tx_empty,
2732 	.set_mctrl	= sci_set_mctrl,
2733 	.get_mctrl	= sci_get_mctrl,
2734 	.start_tx	= sci_start_tx,
2735 	.stop_tx	= sci_stop_tx,
2736 	.stop_rx	= sci_stop_rx,
2737 	.enable_ms	= sci_enable_ms,
2738 	.break_ctl	= sci_break_ctl,
2739 	.startup	= sci_startup,
2740 	.shutdown	= sci_shutdown,
2741 	.flush_buffer	= sci_flush_buffer,
2742 	.set_termios	= sci_set_termios,
2743 	.pm		= sci_pm,
2744 	.type		= sci_type,
2745 	.release_port	= sci_release_port,
2746 	.request_port	= sci_request_port,
2747 	.config_port	= sci_config_port,
2748 	.verify_port	= sci_verify_port,
2749 #ifdef CONFIG_CONSOLE_POLL
2750 	.poll_get_char	= sci_poll_get_char,
2751 	.poll_put_char	= sci_poll_put_char,
2752 #endif
2753 };
2754 
2755 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2756 {
2757 	const char *clk_names[] = {
2758 		[SCI_FCK] = "fck",
2759 		[SCI_SCK] = "sck",
2760 		[SCI_BRG_INT] = "brg_int",
2761 		[SCI_SCIF_CLK] = "scif_clk",
2762 	};
2763 	struct clk *clk;
2764 	unsigned int i;
2765 
2766 	if (sci_port->cfg->type == PORT_HSCIF)
2767 		clk_names[SCI_SCK] = "hsck";
2768 
2769 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2770 		clk = devm_clk_get_optional(dev, clk_names[i]);
2771 		if (IS_ERR(clk))
2772 			return PTR_ERR(clk);
2773 
2774 		if (!clk && i == SCI_FCK) {
2775 			/*
2776 			 * Not all SH platforms declare a clock lookup entry
2777 			 * for SCI devices, in which case we need to get the
2778 			 * global "peripheral_clk" clock.
2779 			 */
2780 			clk = devm_clk_get(dev, "peripheral_clk");
2781 			if (IS_ERR(clk))
2782 				return dev_err_probe(dev, PTR_ERR(clk),
2783 						     "failed to get %s\n",
2784 						     clk_names[i]);
2785 		}
2786 
2787 		if (!clk)
2788 			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2789 		else
2790 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2791 				clk, clk_get_rate(clk));
2792 		sci_port->clks[i] = clk;
2793 	}
2794 	return 0;
2795 }
2796 
2797 static const struct sci_port_params *
2798 sci_probe_regmap(const struct plat_sci_port *cfg)
2799 {
2800 	unsigned int regtype;
2801 
2802 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2803 		return &sci_port_params[cfg->regtype];
2804 
2805 	switch (cfg->type) {
2806 	case PORT_SCI:
2807 		regtype = SCIx_SCI_REGTYPE;
2808 		break;
2809 	case PORT_IRDA:
2810 		regtype = SCIx_IRDA_REGTYPE;
2811 		break;
2812 	case PORT_SCIFA:
2813 		regtype = SCIx_SCIFA_REGTYPE;
2814 		break;
2815 	case PORT_SCIFB:
2816 		regtype = SCIx_SCIFB_REGTYPE;
2817 		break;
2818 	case PORT_SCIF:
2819 		/*
2820 		 * The SH-4 is a bit of a misnomer here, although that's
2821 		 * where this particular port layout originated. This
2822 		 * configuration (or some slight variation thereof)
2823 		 * remains the dominant model for all SCIFs.
2824 		 */
2825 		regtype = SCIx_SH4_SCIF_REGTYPE;
2826 		break;
2827 	case PORT_HSCIF:
2828 		regtype = SCIx_HSCIF_REGTYPE;
2829 		break;
2830 	default:
2831 		pr_err("Can't probe register map for given port\n");
2832 		return NULL;
2833 	}
2834 
2835 	return &sci_port_params[regtype];
2836 }
2837 
2838 static int sci_init_single(struct platform_device *dev,
2839 			   struct sci_port *sci_port, unsigned int index,
2840 			   const struct plat_sci_port *p, bool early)
2841 {
2842 	struct uart_port *port = &sci_port->port;
2843 	const struct resource *res;
2844 	unsigned int i;
2845 	int ret;
2846 
2847 	sci_port->cfg	= p;
2848 
2849 	port->ops	= &sci_uart_ops;
2850 	port->iotype	= UPIO_MEM;
2851 	port->line	= index;
2852 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2853 
2854 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2855 	if (res == NULL)
2856 		return -ENOMEM;
2857 
2858 	port->mapbase = res->start;
2859 	sci_port->reg_size = resource_size(res);
2860 
2861 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2862 		if (i)
2863 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2864 		else
2865 			sci_port->irqs[i] = platform_get_irq(dev, i);
2866 	}
2867 
2868 	/* The SCI generates several interrupts. They can be muxed together or
2869 	 * connected to different interrupt lines. In the muxed case only one
2870 	 * interrupt resource is specified as there is only one interrupt ID.
2871 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2872 	 * from the SCI, however those signals might have their own individual
2873 	 * interrupt ID numbers, or muxed together with another interrupt.
2874 	 */
2875 	if (sci_port->irqs[0] < 0)
2876 		return -ENXIO;
2877 
2878 	if (sci_port->irqs[1] < 0)
2879 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2880 			sci_port->irqs[i] = sci_port->irqs[0];
2881 
2882 	sci_port->params = sci_probe_regmap(p);
2883 	if (unlikely(sci_port->params == NULL))
2884 		return -EINVAL;
2885 
2886 	switch (p->type) {
2887 	case PORT_SCIFB:
2888 		sci_port->rx_trigger = 48;
2889 		break;
2890 	case PORT_HSCIF:
2891 		sci_port->rx_trigger = 64;
2892 		break;
2893 	case PORT_SCIFA:
2894 		sci_port->rx_trigger = 32;
2895 		break;
2896 	case PORT_SCIF:
2897 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2898 			/* RX triggering not implemented for this IP */
2899 			sci_port->rx_trigger = 1;
2900 		else
2901 			sci_port->rx_trigger = 8;
2902 		break;
2903 	default:
2904 		sci_port->rx_trigger = 1;
2905 		break;
2906 	}
2907 
2908 	sci_port->rx_fifo_timeout = 0;
2909 	sci_port->hscif_tot = 0;
2910 
2911 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2912 	 * match the SoC datasheet, this should be investigated. Let platform
2913 	 * data override the sampling rate for now.
2914 	 */
2915 	sci_port->sampling_rate_mask = p->sampling_rate
2916 				     ? SCI_SR(p->sampling_rate)
2917 				     : sci_port->params->sampling_rate_mask;
2918 
2919 	if (!early) {
2920 		ret = sci_init_clocks(sci_port, &dev->dev);
2921 		if (ret < 0)
2922 			return ret;
2923 
2924 		port->dev = &dev->dev;
2925 
2926 		pm_runtime_enable(&dev->dev);
2927 	}
2928 
2929 	port->type		= p->type;
2930 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2931 	port->fifosize		= sci_port->params->fifosize;
2932 
2933 	if (port->type == PORT_SCI) {
2934 		if (sci_port->reg_size >= 0x20)
2935 			port->regshift = 2;
2936 		else
2937 			port->regshift = 1;
2938 	}
2939 
2940 	/*
2941 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2942 	 * for the multi-IRQ ports, which is where we are primarily
2943 	 * concerned with the shutdown path synchronization.
2944 	 *
2945 	 * For the muxed case there's nothing more to do.
2946 	 */
2947 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2948 	port->irqflags		= 0;
2949 
2950 	port->serial_in		= sci_serial_in;
2951 	port->serial_out	= sci_serial_out;
2952 
2953 	return 0;
2954 }
2955 
2956 static void sci_cleanup_single(struct sci_port *port)
2957 {
2958 	pm_runtime_disable(port->port.dev);
2959 }
2960 
2961 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2962     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2963 static void serial_console_putchar(struct uart_port *port, unsigned char ch)
2964 {
2965 	sci_poll_put_char(port, ch);
2966 }
2967 
2968 /*
2969  *	Print a string to the serial port trying not to disturb
2970  *	any possible real use of the port...
2971  */
2972 static void serial_console_write(struct console *co, const char *s,
2973 				 unsigned count)
2974 {
2975 	struct sci_port *sci_port = &sci_ports[co->index];
2976 	struct uart_port *port = &sci_port->port;
2977 	unsigned short bits, ctrl, ctrl_temp;
2978 	unsigned long flags;
2979 	int locked = 1;
2980 
2981 	if (port->sysrq)
2982 		locked = 0;
2983 	else if (oops_in_progress)
2984 		locked = spin_trylock_irqsave(&port->lock, flags);
2985 	else
2986 		spin_lock_irqsave(&port->lock, flags);
2987 
2988 	/* first save SCSCR then disable interrupts, keep clock source */
2989 	ctrl = serial_port_in(port, SCSCR);
2990 	ctrl_temp = SCSCR_RE | SCSCR_TE |
2991 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2992 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2993 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
2994 
2995 	uart_console_write(port, s, count, serial_console_putchar);
2996 
2997 	/* wait until fifo is empty and last bit has been transmitted */
2998 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2999 	while ((serial_port_in(port, SCxSR) & bits) != bits)
3000 		cpu_relax();
3001 
3002 	/* restore the SCSCR */
3003 	serial_port_out(port, SCSCR, ctrl);
3004 
3005 	if (locked)
3006 		spin_unlock_irqrestore(&port->lock, flags);
3007 }
3008 
3009 static int serial_console_setup(struct console *co, char *options)
3010 {
3011 	struct sci_port *sci_port;
3012 	struct uart_port *port;
3013 	int baud = 115200;
3014 	int bits = 8;
3015 	int parity = 'n';
3016 	int flow = 'n';
3017 	int ret;
3018 
3019 	/*
3020 	 * Refuse to handle any bogus ports.
3021 	 */
3022 	if (co->index < 0 || co->index >= SCI_NPORTS)
3023 		return -ENODEV;
3024 
3025 	sci_port = &sci_ports[co->index];
3026 	port = &sci_port->port;
3027 
3028 	/*
3029 	 * Refuse to handle uninitialized ports.
3030 	 */
3031 	if (!port->ops)
3032 		return -ENODEV;
3033 
3034 	ret = sci_remap_port(port);
3035 	if (unlikely(ret != 0))
3036 		return ret;
3037 
3038 	if (options)
3039 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3040 
3041 	return uart_set_options(port, co, baud, parity, bits, flow);
3042 }
3043 
3044 static struct console serial_console = {
3045 	.name		= "ttySC",
3046 	.device		= uart_console_device,
3047 	.write		= serial_console_write,
3048 	.setup		= serial_console_setup,
3049 	.flags		= CON_PRINTBUFFER,
3050 	.index		= -1,
3051 	.data		= &sci_uart_driver,
3052 };
3053 
3054 #ifdef CONFIG_SUPERH
3055 static struct console early_serial_console = {
3056 	.name           = "early_ttySC",
3057 	.write          = serial_console_write,
3058 	.flags          = CON_PRINTBUFFER,
3059 	.index		= -1,
3060 };
3061 
3062 static char early_serial_buf[32];
3063 
3064 static int sci_probe_earlyprintk(struct platform_device *pdev)
3065 {
3066 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3067 
3068 	if (early_serial_console.data)
3069 		return -EEXIST;
3070 
3071 	early_serial_console.index = pdev->id;
3072 
3073 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3074 
3075 	serial_console_setup(&early_serial_console, early_serial_buf);
3076 
3077 	if (!strstr(early_serial_buf, "keep"))
3078 		early_serial_console.flags |= CON_BOOT;
3079 
3080 	register_console(&early_serial_console);
3081 	return 0;
3082 }
3083 #endif
3084 
3085 #define SCI_CONSOLE	(&serial_console)
3086 
3087 #else
3088 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3089 {
3090 	return -EINVAL;
3091 }
3092 
3093 #define SCI_CONSOLE	NULL
3094 
3095 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3096 
3097 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3098 
3099 static DEFINE_MUTEX(sci_uart_registration_lock);
3100 static struct uart_driver sci_uart_driver = {
3101 	.owner		= THIS_MODULE,
3102 	.driver_name	= "sci",
3103 	.dev_name	= "ttySC",
3104 	.major		= SCI_MAJOR,
3105 	.minor		= SCI_MINOR_START,
3106 	.nr		= SCI_NPORTS,
3107 	.cons		= SCI_CONSOLE,
3108 };
3109 
3110 static int sci_remove(struct platform_device *dev)
3111 {
3112 	struct sci_port *port = platform_get_drvdata(dev);
3113 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3114 
3115 	sci_ports_in_use &= ~BIT(port->port.line);
3116 	uart_remove_one_port(&sci_uart_driver, &port->port);
3117 
3118 	sci_cleanup_single(port);
3119 
3120 	if (port->port.fifosize > 1)
3121 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3122 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3123 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3124 
3125 	return 0;
3126 }
3127 
3128 
3129 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3130 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3131 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3132 
3133 static const struct of_device_id of_sci_match[] = {
3134 	/* SoC-specific types */
3135 	{
3136 		.compatible = "renesas,scif-r7s72100",
3137 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3138 	},
3139 	{
3140 		.compatible = "renesas,scif-r7s9210",
3141 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3142 	},
3143 	{
3144 		.compatible = "renesas,scif-r9a07g044",
3145 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3146 	},
3147 	/* Family-specific types */
3148 	{
3149 		.compatible = "renesas,rcar-gen1-scif",
3150 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3151 	}, {
3152 		.compatible = "renesas,rcar-gen2-scif",
3153 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3154 	}, {
3155 		.compatible = "renesas,rcar-gen3-scif",
3156 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3157 	}, {
3158 		.compatible = "renesas,rcar-gen4-scif",
3159 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3160 	},
3161 	/* Generic types */
3162 	{
3163 		.compatible = "renesas,scif",
3164 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3165 	}, {
3166 		.compatible = "renesas,scifa",
3167 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3168 	}, {
3169 		.compatible = "renesas,scifb",
3170 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3171 	}, {
3172 		.compatible = "renesas,hscif",
3173 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3174 	}, {
3175 		.compatible = "renesas,sci",
3176 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3177 	}, {
3178 		/* Terminator */
3179 	},
3180 };
3181 MODULE_DEVICE_TABLE(of, of_sci_match);
3182 
3183 static void sci_reset_control_assert(void *data)
3184 {
3185 	reset_control_assert(data);
3186 }
3187 
3188 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3189 					  unsigned int *dev_id)
3190 {
3191 	struct device_node *np = pdev->dev.of_node;
3192 	struct reset_control *rstc;
3193 	struct plat_sci_port *p;
3194 	struct sci_port *sp;
3195 	const void *data;
3196 	int id, ret;
3197 
3198 	if (!IS_ENABLED(CONFIG_OF) || !np)
3199 		return ERR_PTR(-EINVAL);
3200 
3201 	data = of_device_get_match_data(&pdev->dev);
3202 
3203 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3204 	if (IS_ERR(rstc))
3205 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3206 					     "failed to get reset ctrl\n"));
3207 
3208 	ret = reset_control_deassert(rstc);
3209 	if (ret) {
3210 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3211 		return ERR_PTR(ret);
3212 	}
3213 
3214 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3215 	if (ret) {
3216 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3217 			ret);
3218 		return ERR_PTR(ret);
3219 	}
3220 
3221 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3222 	if (!p)
3223 		return ERR_PTR(-ENOMEM);
3224 
3225 	/* Get the line number from the aliases node. */
3226 	id = of_alias_get_id(np, "serial");
3227 	if (id < 0 && ~sci_ports_in_use)
3228 		id = ffz(sci_ports_in_use);
3229 	if (id < 0) {
3230 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3231 		return ERR_PTR(-EINVAL);
3232 	}
3233 	if (id >= ARRAY_SIZE(sci_ports)) {
3234 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3235 		return ERR_PTR(-EINVAL);
3236 	}
3237 
3238 	sp = &sci_ports[id];
3239 	*dev_id = id;
3240 
3241 	p->type = SCI_OF_TYPE(data);
3242 	p->regtype = SCI_OF_REGTYPE(data);
3243 
3244 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3245 
3246 	return p;
3247 }
3248 
3249 static int sci_probe_single(struct platform_device *dev,
3250 				      unsigned int index,
3251 				      struct plat_sci_port *p,
3252 				      struct sci_port *sciport)
3253 {
3254 	int ret;
3255 
3256 	/* Sanity check */
3257 	if (unlikely(index >= SCI_NPORTS)) {
3258 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3259 			   index+1, SCI_NPORTS);
3260 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3261 		return -EINVAL;
3262 	}
3263 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3264 	if (sci_ports_in_use & BIT(index))
3265 		return -EBUSY;
3266 
3267 	mutex_lock(&sci_uart_registration_lock);
3268 	if (!sci_uart_driver.state) {
3269 		ret = uart_register_driver(&sci_uart_driver);
3270 		if (ret) {
3271 			mutex_unlock(&sci_uart_registration_lock);
3272 			return ret;
3273 		}
3274 	}
3275 	mutex_unlock(&sci_uart_registration_lock);
3276 
3277 	ret = sci_init_single(dev, sciport, index, p, false);
3278 	if (ret)
3279 		return ret;
3280 
3281 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3282 	if (IS_ERR(sciport->gpios))
3283 		return PTR_ERR(sciport->gpios);
3284 
3285 	if (sciport->has_rtscts) {
3286 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3287 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3288 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3289 			return -EINVAL;
3290 		}
3291 		sciport->port.flags |= UPF_HARD_FLOW;
3292 	}
3293 
3294 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3295 	if (ret) {
3296 		sci_cleanup_single(sciport);
3297 		return ret;
3298 	}
3299 
3300 	return 0;
3301 }
3302 
3303 static int sci_probe(struct platform_device *dev)
3304 {
3305 	struct plat_sci_port *p;
3306 	struct sci_port *sp;
3307 	unsigned int dev_id;
3308 	int ret;
3309 
3310 	/*
3311 	 * If we've come here via earlyprintk initialization, head off to
3312 	 * the special early probe. We don't have sufficient device state
3313 	 * to make it beyond this yet.
3314 	 */
3315 #ifdef CONFIG_SUPERH
3316 	if (is_sh_early_platform_device(dev))
3317 		return sci_probe_earlyprintk(dev);
3318 #endif
3319 
3320 	if (dev->dev.of_node) {
3321 		p = sci_parse_dt(dev, &dev_id);
3322 		if (IS_ERR(p))
3323 			return PTR_ERR(p);
3324 	} else {
3325 		p = dev->dev.platform_data;
3326 		if (p == NULL) {
3327 			dev_err(&dev->dev, "no platform data supplied\n");
3328 			return -EINVAL;
3329 		}
3330 
3331 		dev_id = dev->id;
3332 	}
3333 
3334 	sp = &sci_ports[dev_id];
3335 	platform_set_drvdata(dev, sp);
3336 
3337 	ret = sci_probe_single(dev, dev_id, p, sp);
3338 	if (ret)
3339 		return ret;
3340 
3341 	if (sp->port.fifosize > 1) {
3342 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3343 		if (ret)
3344 			return ret;
3345 	}
3346 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3347 	    sp->port.type == PORT_HSCIF) {
3348 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3349 		if (ret) {
3350 			if (sp->port.fifosize > 1) {
3351 				device_remove_file(&dev->dev,
3352 						   &dev_attr_rx_fifo_trigger);
3353 			}
3354 			return ret;
3355 		}
3356 	}
3357 
3358 #ifdef CONFIG_SH_STANDARD_BIOS
3359 	sh_bios_gdb_detach();
3360 #endif
3361 
3362 	sci_ports_in_use |= BIT(dev_id);
3363 	return 0;
3364 }
3365 
3366 static __maybe_unused int sci_suspend(struct device *dev)
3367 {
3368 	struct sci_port *sport = dev_get_drvdata(dev);
3369 
3370 	if (sport)
3371 		uart_suspend_port(&sci_uart_driver, &sport->port);
3372 
3373 	return 0;
3374 }
3375 
3376 static __maybe_unused int sci_resume(struct device *dev)
3377 {
3378 	struct sci_port *sport = dev_get_drvdata(dev);
3379 
3380 	if (sport)
3381 		uart_resume_port(&sci_uart_driver, &sport->port);
3382 
3383 	return 0;
3384 }
3385 
3386 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3387 
3388 static struct platform_driver sci_driver = {
3389 	.probe		= sci_probe,
3390 	.remove		= sci_remove,
3391 	.driver		= {
3392 		.name	= "sh-sci",
3393 		.pm	= &sci_dev_pm_ops,
3394 		.of_match_table = of_match_ptr(of_sci_match),
3395 	},
3396 };
3397 
3398 static int __init sci_init(void)
3399 {
3400 	pr_info("%s\n", banner);
3401 
3402 	return platform_driver_register(&sci_driver);
3403 }
3404 
3405 static void __exit sci_exit(void)
3406 {
3407 	platform_driver_unregister(&sci_driver);
3408 
3409 	if (sci_uart_driver.state)
3410 		uart_unregister_driver(&sci_uart_driver);
3411 }
3412 
3413 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3414 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3415 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3416 #endif
3417 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3418 static struct plat_sci_port port_cfg __initdata;
3419 
3420 static int __init early_console_setup(struct earlycon_device *device,
3421 				      int type)
3422 {
3423 	if (!device->port.membase)
3424 		return -ENODEV;
3425 
3426 	device->port.serial_in = sci_serial_in;
3427 	device->port.serial_out	= sci_serial_out;
3428 	device->port.type = type;
3429 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3430 	port_cfg.type = type;
3431 	sci_ports[0].cfg = &port_cfg;
3432 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3433 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3434 	sci_serial_out(&sci_ports[0].port, SCSCR,
3435 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3436 
3437 	device->con->write = serial_console_write;
3438 	return 0;
3439 }
3440 static int __init sci_early_console_setup(struct earlycon_device *device,
3441 					  const char *opt)
3442 {
3443 	return early_console_setup(device, PORT_SCI);
3444 }
3445 static int __init scif_early_console_setup(struct earlycon_device *device,
3446 					  const char *opt)
3447 {
3448 	return early_console_setup(device, PORT_SCIF);
3449 }
3450 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3451 					  const char *opt)
3452 {
3453 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3454 	return early_console_setup(device, PORT_SCIF);
3455 }
3456 
3457 static int __init scifa_early_console_setup(struct earlycon_device *device,
3458 					  const char *opt)
3459 {
3460 	return early_console_setup(device, PORT_SCIFA);
3461 }
3462 static int __init scifb_early_console_setup(struct earlycon_device *device,
3463 					  const char *opt)
3464 {
3465 	return early_console_setup(device, PORT_SCIFB);
3466 }
3467 static int __init hscif_early_console_setup(struct earlycon_device *device,
3468 					  const char *opt)
3469 {
3470 	return early_console_setup(device, PORT_HSCIF);
3471 }
3472 
3473 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3474 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3475 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3476 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3477 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3478 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3479 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3480 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3481 
3482 module_init(sci_init);
3483 module_exit(sci_exit);
3484 
3485 MODULE_LICENSE("GPL");
3486 MODULE_ALIAS("platform:sh-sci");
3487 MODULE_AUTHOR("Paul Mundt");
3488 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3489