xref: /openbmc/linux/drivers/tty/serial/sh-sci.c (revision 3ac14b39)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 #define SUPPORT_SYSRQ
20 #endif
21 
22 #undef DEBUG
23 
24 #include <linux/clk.h>
25 #include <linux/console.h>
26 #include <linux/ctype.h>
27 #include <linux/cpufreq.h>
28 #include <linux/delay.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/err.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/ioport.h>
36 #include <linux/ktime.h>
37 #include <linux/major.h>
38 #include <linux/module.h>
39 #include <linux/mm.h>
40 #include <linux/of.h>
41 #include <linux/of_device.h>
42 #include <linux/platform_device.h>
43 #include <linux/pm_runtime.h>
44 #include <linux/scatterlist.h>
45 #include <linux/serial.h>
46 #include <linux/serial_sci.h>
47 #include <linux/sh_dma.h>
48 #include <linux/slab.h>
49 #include <linux/string.h>
50 #include <linux/sysrq.h>
51 #include <linux/timer.h>
52 #include <linux/tty.h>
53 #include <linux/tty_flip.h>
54 
55 #ifdef CONFIG_SUPERH
56 #include <asm/sh_bios.h>
57 #endif
58 
59 #include "serial_mctrl_gpio.h"
60 #include "sh-sci.h"
61 
62 /* Offsets into the sci_port->irqs array */
63 enum {
64 	SCIx_ERI_IRQ,
65 	SCIx_RXI_IRQ,
66 	SCIx_TXI_IRQ,
67 	SCIx_BRI_IRQ,
68 	SCIx_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 	dma_cookie_t			cookie_tx;
139 	dma_cookie_t			cookie_rx[2];
140 	dma_cookie_t			active_rx;
141 	dma_addr_t			tx_dma_addr;
142 	unsigned int			tx_dma_len;
143 	struct scatterlist		sg_rx[2];
144 	void				*rx_buf[2];
145 	size_t				buf_len_rx;
146 	struct work_struct		work_tx;
147 	struct hrtimer			rx_timer;
148 	unsigned int			rx_timeout;	/* microseconds */
149 #endif
150 	unsigned int			rx_frame;
151 	int				rx_trigger;
152 	struct timer_list		rx_fifo_timer;
153 	int				rx_fifo_timeout;
154 	u16				hscif_tot;
155 
156 	bool has_rtscts;
157 	bool autorts;
158 };
159 
160 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
161 
162 static struct sci_port sci_ports[SCI_NPORTS];
163 static unsigned long sci_ports_in_use;
164 static struct uart_driver sci_uart_driver;
165 
166 static inline struct sci_port *
167 to_sci_port(struct uart_port *uart)
168 {
169 	return container_of(uart, struct sci_port, port);
170 }
171 
172 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
173 	/*
174 	 * Common SCI definitions, dependent on the port's regshift
175 	 * value.
176 	 */
177 	[SCIx_SCI_REGTYPE] = {
178 		.regs = {
179 			[SCSMR]		= { 0x00,  8 },
180 			[SCBRR]		= { 0x01,  8 },
181 			[SCSCR]		= { 0x02,  8 },
182 			[SCxTDR]	= { 0x03,  8 },
183 			[SCxSR]		= { 0x04,  8 },
184 			[SCxRDR]	= { 0x05,  8 },
185 		},
186 		.fifosize = 1,
187 		.overrun_reg = SCxSR,
188 		.overrun_mask = SCI_ORER,
189 		.sampling_rate_mask = SCI_SR(32),
190 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
191 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
192 	},
193 
194 	/*
195 	 * Common definitions for legacy IrDA ports.
196 	 */
197 	[SCIx_IRDA_REGTYPE] = {
198 		.regs = {
199 			[SCSMR]		= { 0x00,  8 },
200 			[SCBRR]		= { 0x02,  8 },
201 			[SCSCR]		= { 0x04,  8 },
202 			[SCxTDR]	= { 0x06,  8 },
203 			[SCxSR]		= { 0x08, 16 },
204 			[SCxRDR]	= { 0x0a,  8 },
205 			[SCFCR]		= { 0x0c,  8 },
206 			[SCFDR]		= { 0x0e, 16 },
207 		},
208 		.fifosize = 1,
209 		.overrun_reg = SCxSR,
210 		.overrun_mask = SCI_ORER,
211 		.sampling_rate_mask = SCI_SR(32),
212 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
213 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
214 	},
215 
216 	/*
217 	 * Common SCIFA definitions.
218 	 */
219 	[SCIx_SCIFA_REGTYPE] = {
220 		.regs = {
221 			[SCSMR]		= { 0x00, 16 },
222 			[SCBRR]		= { 0x04,  8 },
223 			[SCSCR]		= { 0x08, 16 },
224 			[SCxTDR]	= { 0x20,  8 },
225 			[SCxSR]		= { 0x14, 16 },
226 			[SCxRDR]	= { 0x24,  8 },
227 			[SCFCR]		= { 0x18, 16 },
228 			[SCFDR]		= { 0x1c, 16 },
229 			[SCPCR]		= { 0x30, 16 },
230 			[SCPDR]		= { 0x34, 16 },
231 		},
232 		.fifosize = 64,
233 		.overrun_reg = SCxSR,
234 		.overrun_mask = SCIFA_ORER,
235 		.sampling_rate_mask = SCI_SR_SCIFAB,
236 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
237 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
238 	},
239 
240 	/*
241 	 * Common SCIFB definitions.
242 	 */
243 	[SCIx_SCIFB_REGTYPE] = {
244 		.regs = {
245 			[SCSMR]		= { 0x00, 16 },
246 			[SCBRR]		= { 0x04,  8 },
247 			[SCSCR]		= { 0x08, 16 },
248 			[SCxTDR]	= { 0x40,  8 },
249 			[SCxSR]		= { 0x14, 16 },
250 			[SCxRDR]	= { 0x60,  8 },
251 			[SCFCR]		= { 0x18, 16 },
252 			[SCTFDR]	= { 0x38, 16 },
253 			[SCRFDR]	= { 0x3c, 16 },
254 			[SCPCR]		= { 0x30, 16 },
255 			[SCPDR]		= { 0x34, 16 },
256 		},
257 		.fifosize = 256,
258 		.overrun_reg = SCxSR,
259 		.overrun_mask = SCIFA_ORER,
260 		.sampling_rate_mask = SCI_SR_SCIFAB,
261 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
262 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
263 	},
264 
265 	/*
266 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
267 	 * count registers.
268 	 */
269 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
270 		.regs = {
271 			[SCSMR]		= { 0x00, 16 },
272 			[SCBRR]		= { 0x04,  8 },
273 			[SCSCR]		= { 0x08, 16 },
274 			[SCxTDR]	= { 0x0c,  8 },
275 			[SCxSR]		= { 0x10, 16 },
276 			[SCxRDR]	= { 0x14,  8 },
277 			[SCFCR]		= { 0x18, 16 },
278 			[SCFDR]		= { 0x1c, 16 },
279 			[SCSPTR]	= { 0x20, 16 },
280 			[SCLSR]		= { 0x24, 16 },
281 		},
282 		.fifosize = 16,
283 		.overrun_reg = SCLSR,
284 		.overrun_mask = SCLSR_ORER,
285 		.sampling_rate_mask = SCI_SR(32),
286 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
287 		.error_clear = SCIF_ERROR_CLEAR,
288 	},
289 
290 	/*
291 	 * Common SH-3 SCIF definitions.
292 	 */
293 	[SCIx_SH3_SCIF_REGTYPE] = {
294 		.regs = {
295 			[SCSMR]		= { 0x00,  8 },
296 			[SCBRR]		= { 0x02,  8 },
297 			[SCSCR]		= { 0x04,  8 },
298 			[SCxTDR]	= { 0x06,  8 },
299 			[SCxSR]		= { 0x08, 16 },
300 			[SCxRDR]	= { 0x0a,  8 },
301 			[SCFCR]		= { 0x0c,  8 },
302 			[SCFDR]		= { 0x0e, 16 },
303 		},
304 		.fifosize = 16,
305 		.overrun_reg = SCLSR,
306 		.overrun_mask = SCLSR_ORER,
307 		.sampling_rate_mask = SCI_SR(32),
308 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
309 		.error_clear = SCIF_ERROR_CLEAR,
310 	},
311 
312 	/*
313 	 * Common SH-4(A) SCIF(B) definitions.
314 	 */
315 	[SCIx_SH4_SCIF_REGTYPE] = {
316 		.regs = {
317 			[SCSMR]		= { 0x00, 16 },
318 			[SCBRR]		= { 0x04,  8 },
319 			[SCSCR]		= { 0x08, 16 },
320 			[SCxTDR]	= { 0x0c,  8 },
321 			[SCxSR]		= { 0x10, 16 },
322 			[SCxRDR]	= { 0x14,  8 },
323 			[SCFCR]		= { 0x18, 16 },
324 			[SCFDR]		= { 0x1c, 16 },
325 			[SCSPTR]	= { 0x20, 16 },
326 			[SCLSR]		= { 0x24, 16 },
327 		},
328 		.fifosize = 16,
329 		.overrun_reg = SCLSR,
330 		.overrun_mask = SCLSR_ORER,
331 		.sampling_rate_mask = SCI_SR(32),
332 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
333 		.error_clear = SCIF_ERROR_CLEAR,
334 	},
335 
336 	/*
337 	 * Common SCIF definitions for ports with a Baud Rate Generator for
338 	 * External Clock (BRG).
339 	 */
340 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
341 		.regs = {
342 			[SCSMR]		= { 0x00, 16 },
343 			[SCBRR]		= { 0x04,  8 },
344 			[SCSCR]		= { 0x08, 16 },
345 			[SCxTDR]	= { 0x0c,  8 },
346 			[SCxSR]		= { 0x10, 16 },
347 			[SCxRDR]	= { 0x14,  8 },
348 			[SCFCR]		= { 0x18, 16 },
349 			[SCFDR]		= { 0x1c, 16 },
350 			[SCSPTR]	= { 0x20, 16 },
351 			[SCLSR]		= { 0x24, 16 },
352 			[SCDL]		= { 0x30, 16 },
353 			[SCCKS]		= { 0x34, 16 },
354 		},
355 		.fifosize = 16,
356 		.overrun_reg = SCLSR,
357 		.overrun_mask = SCLSR_ORER,
358 		.sampling_rate_mask = SCI_SR(32),
359 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
360 		.error_clear = SCIF_ERROR_CLEAR,
361 	},
362 
363 	/*
364 	 * Common HSCIF definitions.
365 	 */
366 	[SCIx_HSCIF_REGTYPE] = {
367 		.regs = {
368 			[SCSMR]		= { 0x00, 16 },
369 			[SCBRR]		= { 0x04,  8 },
370 			[SCSCR]		= { 0x08, 16 },
371 			[SCxTDR]	= { 0x0c,  8 },
372 			[SCxSR]		= { 0x10, 16 },
373 			[SCxRDR]	= { 0x14,  8 },
374 			[SCFCR]		= { 0x18, 16 },
375 			[SCFDR]		= { 0x1c, 16 },
376 			[SCSPTR]	= { 0x20, 16 },
377 			[SCLSR]		= { 0x24, 16 },
378 			[HSSRR]		= { 0x40, 16 },
379 			[SCDL]		= { 0x30, 16 },
380 			[SCCKS]		= { 0x34, 16 },
381 			[HSRTRGR]	= { 0x54, 16 },
382 			[HSTTRGR]	= { 0x58, 16 },
383 		},
384 		.fifosize = 128,
385 		.overrun_reg = SCLSR,
386 		.overrun_mask = SCLSR_ORER,
387 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
388 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
389 		.error_clear = SCIF_ERROR_CLEAR,
390 	},
391 
392 	/*
393 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
394 	 * register.
395 	 */
396 	[SCIx_SH4_SCIF_NO_SCSPTR_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 			[SCLSR]		= { 0x24, 16 },
407 		},
408 		.fifosize = 16,
409 		.overrun_reg = SCLSR,
410 		.overrun_mask = SCLSR_ORER,
411 		.sampling_rate_mask = SCI_SR(32),
412 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
413 		.error_clear = SCIF_ERROR_CLEAR,
414 	},
415 
416 	/*
417 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
418 	 * count registers.
419 	 */
420 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
421 		.regs = {
422 			[SCSMR]		= { 0x00, 16 },
423 			[SCBRR]		= { 0x04,  8 },
424 			[SCSCR]		= { 0x08, 16 },
425 			[SCxTDR]	= { 0x0c,  8 },
426 			[SCxSR]		= { 0x10, 16 },
427 			[SCxRDR]	= { 0x14,  8 },
428 			[SCFCR]		= { 0x18, 16 },
429 			[SCFDR]		= { 0x1c, 16 },
430 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
431 			[SCRFDR]	= { 0x20, 16 },
432 			[SCSPTR]	= { 0x24, 16 },
433 			[SCLSR]		= { 0x28, 16 },
434 		},
435 		.fifosize = 16,
436 		.overrun_reg = SCLSR,
437 		.overrun_mask = SCLSR_ORER,
438 		.sampling_rate_mask = SCI_SR(32),
439 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
440 		.error_clear = SCIF_ERROR_CLEAR,
441 	},
442 
443 	/*
444 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
445 	 * registers.
446 	 */
447 	[SCIx_SH7705_SCIF_REGTYPE] = {
448 		.regs = {
449 			[SCSMR]		= { 0x00, 16 },
450 			[SCBRR]		= { 0x04,  8 },
451 			[SCSCR]		= { 0x08, 16 },
452 			[SCxTDR]	= { 0x20,  8 },
453 			[SCxSR]		= { 0x14, 16 },
454 			[SCxRDR]	= { 0x24,  8 },
455 			[SCFCR]		= { 0x18, 16 },
456 			[SCFDR]		= { 0x1c, 16 },
457 		},
458 		.fifosize = 64,
459 		.overrun_reg = SCxSR,
460 		.overrun_mask = SCIFA_ORER,
461 		.sampling_rate_mask = SCI_SR(16),
462 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
463 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
464 	},
465 };
466 
467 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
468 
469 /*
470  * The "offset" here is rather misleading, in that it refers to an enum
471  * value relative to the port mapping rather than the fixed offset
472  * itself, which needs to be manually retrieved from the platform's
473  * register map for the given port.
474  */
475 static unsigned int sci_serial_in(struct uart_port *p, int offset)
476 {
477 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
478 
479 	if (reg->size == 8)
480 		return ioread8(p->membase + (reg->offset << p->regshift));
481 	else if (reg->size == 16)
482 		return ioread16(p->membase + (reg->offset << p->regshift));
483 	else
484 		WARN(1, "Invalid register access\n");
485 
486 	return 0;
487 }
488 
489 static void sci_serial_out(struct uart_port *p, int offset, int value)
490 {
491 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
492 
493 	if (reg->size == 8)
494 		iowrite8(value, p->membase + (reg->offset << p->regshift));
495 	else if (reg->size == 16)
496 		iowrite16(value, p->membase + (reg->offset << p->regshift));
497 	else
498 		WARN(1, "Invalid register access\n");
499 }
500 
501 static void sci_port_enable(struct sci_port *sci_port)
502 {
503 	unsigned int i;
504 
505 	if (!sci_port->port.dev)
506 		return;
507 
508 	pm_runtime_get_sync(sci_port->port.dev);
509 
510 	for (i = 0; i < SCI_NUM_CLKS; i++) {
511 		clk_prepare_enable(sci_port->clks[i]);
512 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
513 	}
514 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
515 }
516 
517 static void sci_port_disable(struct sci_port *sci_port)
518 {
519 	unsigned int i;
520 
521 	if (!sci_port->port.dev)
522 		return;
523 
524 	for (i = SCI_NUM_CLKS; i-- > 0; )
525 		clk_disable_unprepare(sci_port->clks[i]);
526 
527 	pm_runtime_put_sync(sci_port->port.dev);
528 }
529 
530 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
531 {
532 	/*
533 	 * Not all ports (such as SCIFA) will support REIE. Rather than
534 	 * special-casing the port type, we check the port initialization
535 	 * IRQ enable mask to see whether the IRQ is desired at all. If
536 	 * it's unset, it's logically inferred that there's no point in
537 	 * testing for it.
538 	 */
539 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
540 }
541 
542 static void sci_start_tx(struct uart_port *port)
543 {
544 	struct sci_port *s = to_sci_port(port);
545 	unsigned short ctrl;
546 
547 #ifdef CONFIG_SERIAL_SH_SCI_DMA
548 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
549 		u16 new, scr = serial_port_in(port, SCSCR);
550 		if (s->chan_tx)
551 			new = scr | SCSCR_TDRQE;
552 		else
553 			new = scr & ~SCSCR_TDRQE;
554 		if (new != scr)
555 			serial_port_out(port, SCSCR, new);
556 	}
557 
558 	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
559 	    dma_submit_error(s->cookie_tx)) {
560 		s->cookie_tx = 0;
561 		schedule_work(&s->work_tx);
562 	}
563 #endif
564 
565 	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
566 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
567 		ctrl = serial_port_in(port, SCSCR);
568 		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
569 	}
570 }
571 
572 static void sci_stop_tx(struct uart_port *port)
573 {
574 	unsigned short ctrl;
575 
576 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
577 	ctrl = serial_port_in(port, SCSCR);
578 
579 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
580 		ctrl &= ~SCSCR_TDRQE;
581 
582 	ctrl &= ~SCSCR_TIE;
583 
584 	serial_port_out(port, SCSCR, ctrl);
585 }
586 
587 static void sci_start_rx(struct uart_port *port)
588 {
589 	unsigned short ctrl;
590 
591 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
592 
593 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
594 		ctrl &= ~SCSCR_RDRQE;
595 
596 	serial_port_out(port, SCSCR, ctrl);
597 }
598 
599 static void sci_stop_rx(struct uart_port *port)
600 {
601 	unsigned short ctrl;
602 
603 	ctrl = serial_port_in(port, SCSCR);
604 
605 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
606 		ctrl &= ~SCSCR_RDRQE;
607 
608 	ctrl &= ~port_rx_irq_mask(port);
609 
610 	serial_port_out(port, SCSCR, ctrl);
611 }
612 
613 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
614 {
615 	if (port->type == PORT_SCI) {
616 		/* Just store the mask */
617 		serial_port_out(port, SCxSR, mask);
618 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
619 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
620 		/* Only clear the status bits we want to clear */
621 		serial_port_out(port, SCxSR,
622 				serial_port_in(port, SCxSR) & mask);
623 	} else {
624 		/* Store the mask, clear parity/framing errors */
625 		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
626 	}
627 }
628 
629 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
630     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
631 
632 #ifdef CONFIG_CONSOLE_POLL
633 static int sci_poll_get_char(struct uart_port *port)
634 {
635 	unsigned short status;
636 	int c;
637 
638 	do {
639 		status = serial_port_in(port, SCxSR);
640 		if (status & SCxSR_ERRORS(port)) {
641 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
642 			continue;
643 		}
644 		break;
645 	} while (1);
646 
647 	if (!(status & SCxSR_RDxF(port)))
648 		return NO_POLL_CHAR;
649 
650 	c = serial_port_in(port, SCxRDR);
651 
652 	/* Dummy read */
653 	serial_port_in(port, SCxSR);
654 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
655 
656 	return c;
657 }
658 #endif
659 
660 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
661 {
662 	unsigned short status;
663 
664 	do {
665 		status = serial_port_in(port, SCxSR);
666 	} while (!(status & SCxSR_TDxE(port)));
667 
668 	serial_port_out(port, SCxTDR, c);
669 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
670 }
671 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
672 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
673 
674 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
675 {
676 	struct sci_port *s = to_sci_port(port);
677 
678 	/*
679 	 * Use port-specific handler if provided.
680 	 */
681 	if (s->cfg->ops && s->cfg->ops->init_pins) {
682 		s->cfg->ops->init_pins(port, cflag);
683 		return;
684 	}
685 
686 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
687 		u16 data = serial_port_in(port, SCPDR);
688 		u16 ctrl = serial_port_in(port, SCPCR);
689 
690 		/* Enable RXD and TXD pin functions */
691 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
692 		if (to_sci_port(port)->has_rtscts) {
693 			/* RTS# is output, active low, unless autorts */
694 			if (!(port->mctrl & TIOCM_RTS)) {
695 				ctrl |= SCPCR_RTSC;
696 				data |= SCPDR_RTSD;
697 			} else if (!s->autorts) {
698 				ctrl |= SCPCR_RTSC;
699 				data &= ~SCPDR_RTSD;
700 			} else {
701 				/* Enable RTS# pin function */
702 				ctrl &= ~SCPCR_RTSC;
703 			}
704 			/* Enable CTS# pin function */
705 			ctrl &= ~SCPCR_CTSC;
706 		}
707 		serial_port_out(port, SCPDR, data);
708 		serial_port_out(port, SCPCR, ctrl);
709 	} else if (sci_getreg(port, SCSPTR)->size) {
710 		u16 status = serial_port_in(port, SCSPTR);
711 
712 		/* RTS# is always output; and active low, unless autorts */
713 		status |= SCSPTR_RTSIO;
714 		if (!(port->mctrl & TIOCM_RTS))
715 			status |= SCSPTR_RTSDT;
716 		else if (!s->autorts)
717 			status &= ~SCSPTR_RTSDT;
718 		/* CTS# and SCK are inputs */
719 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
720 		serial_port_out(port, SCSPTR, status);
721 	}
722 }
723 
724 static int sci_txfill(struct uart_port *port)
725 {
726 	struct sci_port *s = to_sci_port(port);
727 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
728 	const struct plat_sci_reg *reg;
729 
730 	reg = sci_getreg(port, SCTFDR);
731 	if (reg->size)
732 		return serial_port_in(port, SCTFDR) & fifo_mask;
733 
734 	reg = sci_getreg(port, SCFDR);
735 	if (reg->size)
736 		return serial_port_in(port, SCFDR) >> 8;
737 
738 	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
739 }
740 
741 static int sci_txroom(struct uart_port *port)
742 {
743 	return port->fifosize - sci_txfill(port);
744 }
745 
746 static int sci_rxfill(struct uart_port *port)
747 {
748 	struct sci_port *s = to_sci_port(port);
749 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
750 	const struct plat_sci_reg *reg;
751 
752 	reg = sci_getreg(port, SCRFDR);
753 	if (reg->size)
754 		return serial_port_in(port, SCRFDR) & fifo_mask;
755 
756 	reg = sci_getreg(port, SCFDR);
757 	if (reg->size)
758 		return serial_port_in(port, SCFDR) & fifo_mask;
759 
760 	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
761 }
762 
763 /* ********************************************************************** *
764  *                   the interrupt related routines                       *
765  * ********************************************************************** */
766 
767 static void sci_transmit_chars(struct uart_port *port)
768 {
769 	struct circ_buf *xmit = &port->state->xmit;
770 	unsigned int stopped = uart_tx_stopped(port);
771 	unsigned short status;
772 	unsigned short ctrl;
773 	int count;
774 
775 	status = serial_port_in(port, SCxSR);
776 	if (!(status & SCxSR_TDxE(port))) {
777 		ctrl = serial_port_in(port, SCSCR);
778 		if (uart_circ_empty(xmit))
779 			ctrl &= ~SCSCR_TIE;
780 		else
781 			ctrl |= SCSCR_TIE;
782 		serial_port_out(port, SCSCR, ctrl);
783 		return;
784 	}
785 
786 	count = sci_txroom(port);
787 
788 	do {
789 		unsigned char c;
790 
791 		if (port->x_char) {
792 			c = port->x_char;
793 			port->x_char = 0;
794 		} else if (!uart_circ_empty(xmit) && !stopped) {
795 			c = xmit->buf[xmit->tail];
796 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
797 		} else {
798 			break;
799 		}
800 
801 		serial_port_out(port, SCxTDR, c);
802 
803 		port->icount.tx++;
804 	} while (--count > 0);
805 
806 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
807 
808 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
809 		uart_write_wakeup(port);
810 	if (uart_circ_empty(xmit)) {
811 		sci_stop_tx(port);
812 	} else {
813 		ctrl = serial_port_in(port, SCSCR);
814 
815 		if (port->type != PORT_SCI) {
816 			serial_port_in(port, SCxSR); /* Dummy read */
817 			sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
818 		}
819 
820 		ctrl |= SCSCR_TIE;
821 		serial_port_out(port, SCSCR, ctrl);
822 	}
823 }
824 
825 /* On SH3, SCIF may read end-of-break as a space->mark char */
826 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
827 
828 static void sci_receive_chars(struct uart_port *port)
829 {
830 	struct tty_port *tport = &port->state->port;
831 	int i, count, copied = 0;
832 	unsigned short status;
833 	unsigned char flag;
834 
835 	status = serial_port_in(port, SCxSR);
836 	if (!(status & SCxSR_RDxF(port)))
837 		return;
838 
839 	while (1) {
840 		/* Don't copy more bytes than there is room for in the buffer */
841 		count = tty_buffer_request_room(tport, sci_rxfill(port));
842 
843 		/* If for any reason we can't copy more data, we're done! */
844 		if (count == 0)
845 			break;
846 
847 		if (port->type == PORT_SCI) {
848 			char c = serial_port_in(port, SCxRDR);
849 			if (uart_handle_sysrq_char(port, c))
850 				count = 0;
851 			else
852 				tty_insert_flip_char(tport, c, TTY_NORMAL);
853 		} else {
854 			for (i = 0; i < count; i++) {
855 				char c = serial_port_in(port, SCxRDR);
856 
857 				status = serial_port_in(port, SCxSR);
858 				if (uart_handle_sysrq_char(port, c)) {
859 					count--; i--;
860 					continue;
861 				}
862 
863 				/* Store data and status */
864 				if (status & SCxSR_FER(port)) {
865 					flag = TTY_FRAME;
866 					port->icount.frame++;
867 					dev_notice(port->dev, "frame error\n");
868 				} else if (status & SCxSR_PER(port)) {
869 					flag = TTY_PARITY;
870 					port->icount.parity++;
871 					dev_notice(port->dev, "parity error\n");
872 				} else
873 					flag = TTY_NORMAL;
874 
875 				tty_insert_flip_char(tport, c, flag);
876 			}
877 		}
878 
879 		serial_port_in(port, SCxSR); /* dummy read */
880 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
881 
882 		copied += count;
883 		port->icount.rx += count;
884 	}
885 
886 	if (copied) {
887 		/* Tell the rest of the system the news. New characters! */
888 		tty_flip_buffer_push(tport);
889 	} else {
890 		/* TTY buffers full; read from RX reg to prevent lockup */
891 		serial_port_in(port, SCxRDR);
892 		serial_port_in(port, SCxSR); /* dummy read */
893 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
894 	}
895 }
896 
897 static int sci_handle_errors(struct uart_port *port)
898 {
899 	int copied = 0;
900 	unsigned short status = serial_port_in(port, SCxSR);
901 	struct tty_port *tport = &port->state->port;
902 	struct sci_port *s = to_sci_port(port);
903 
904 	/* Handle overruns */
905 	if (status & s->params->overrun_mask) {
906 		port->icount.overrun++;
907 
908 		/* overrun error */
909 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
910 			copied++;
911 
912 		dev_notice(port->dev, "overrun error\n");
913 	}
914 
915 	if (status & SCxSR_FER(port)) {
916 		/* frame error */
917 		port->icount.frame++;
918 
919 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
920 			copied++;
921 
922 		dev_notice(port->dev, "frame error\n");
923 	}
924 
925 	if (status & SCxSR_PER(port)) {
926 		/* parity error */
927 		port->icount.parity++;
928 
929 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
930 			copied++;
931 
932 		dev_notice(port->dev, "parity error\n");
933 	}
934 
935 	if (copied)
936 		tty_flip_buffer_push(tport);
937 
938 	return copied;
939 }
940 
941 static int sci_handle_fifo_overrun(struct uart_port *port)
942 {
943 	struct tty_port *tport = &port->state->port;
944 	struct sci_port *s = to_sci_port(port);
945 	const struct plat_sci_reg *reg;
946 	int copied = 0;
947 	u16 status;
948 
949 	reg = sci_getreg(port, s->params->overrun_reg);
950 	if (!reg->size)
951 		return 0;
952 
953 	status = serial_port_in(port, s->params->overrun_reg);
954 	if (status & s->params->overrun_mask) {
955 		status &= ~s->params->overrun_mask;
956 		serial_port_out(port, s->params->overrun_reg, status);
957 
958 		port->icount.overrun++;
959 
960 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
961 		tty_flip_buffer_push(tport);
962 
963 		dev_dbg(port->dev, "overrun error\n");
964 		copied++;
965 	}
966 
967 	return copied;
968 }
969 
970 static int sci_handle_breaks(struct uart_port *port)
971 {
972 	int copied = 0;
973 	unsigned short status = serial_port_in(port, SCxSR);
974 	struct tty_port *tport = &port->state->port;
975 
976 	if (uart_handle_break(port))
977 		return 0;
978 
979 	if (status & SCxSR_BRK(port)) {
980 		port->icount.brk++;
981 
982 		/* Notify of BREAK */
983 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
984 			copied++;
985 
986 		dev_dbg(port->dev, "BREAK detected\n");
987 	}
988 
989 	if (copied)
990 		tty_flip_buffer_push(tport);
991 
992 	copied += sci_handle_fifo_overrun(port);
993 
994 	return copied;
995 }
996 
997 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
998 {
999 	unsigned int bits;
1000 
1001 	if (rx_trig < 1)
1002 		rx_trig = 1;
1003 	if (rx_trig >= port->fifosize)
1004 		rx_trig = port->fifosize;
1005 
1006 	/* HSCIF can be set to an arbitrary level. */
1007 	if (sci_getreg(port, HSRTRGR)->size) {
1008 		serial_port_out(port, HSRTRGR, rx_trig);
1009 		return rx_trig;
1010 	}
1011 
1012 	switch (port->type) {
1013 	case PORT_SCIF:
1014 		if (rx_trig < 4) {
1015 			bits = 0;
1016 			rx_trig = 1;
1017 		} else if (rx_trig < 8) {
1018 			bits = SCFCR_RTRG0;
1019 			rx_trig = 4;
1020 		} else if (rx_trig < 14) {
1021 			bits = SCFCR_RTRG1;
1022 			rx_trig = 8;
1023 		} else {
1024 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1025 			rx_trig = 14;
1026 		}
1027 		break;
1028 	case PORT_SCIFA:
1029 	case PORT_SCIFB:
1030 		if (rx_trig < 16) {
1031 			bits = 0;
1032 			rx_trig = 1;
1033 		} else if (rx_trig < 32) {
1034 			bits = SCFCR_RTRG0;
1035 			rx_trig = 16;
1036 		} else if (rx_trig < 48) {
1037 			bits = SCFCR_RTRG1;
1038 			rx_trig = 32;
1039 		} else {
1040 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1041 			rx_trig = 48;
1042 		}
1043 		break;
1044 	default:
1045 		WARN(1, "unknown FIFO configuration");
1046 		return 1;
1047 	}
1048 
1049 	serial_port_out(port, SCFCR,
1050 		(serial_port_in(port, SCFCR) &
1051 		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1052 
1053 	return rx_trig;
1054 }
1055 
1056 static int scif_rtrg_enabled(struct uart_port *port)
1057 {
1058 	if (sci_getreg(port, HSRTRGR)->size)
1059 		return serial_port_in(port, HSRTRGR) != 0;
1060 	else
1061 		return (serial_port_in(port, SCFCR) &
1062 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1063 }
1064 
1065 static void rx_fifo_timer_fn(struct timer_list *t)
1066 {
1067 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1068 	struct uart_port *port = &s->port;
1069 
1070 	dev_dbg(port->dev, "Rx timed out\n");
1071 	scif_set_rtrg(port, 1);
1072 }
1073 
1074 static ssize_t rx_trigger_show(struct device *dev,
1075 			       struct device_attribute *attr,
1076 			       char *buf)
1077 {
1078 	struct uart_port *port = dev_get_drvdata(dev);
1079 	struct sci_port *sci = to_sci_port(port);
1080 
1081 	return sprintf(buf, "%d\n", sci->rx_trigger);
1082 }
1083 
1084 static ssize_t rx_trigger_store(struct device *dev,
1085 				struct device_attribute *attr,
1086 				const char *buf,
1087 				size_t count)
1088 {
1089 	struct uart_port *port = dev_get_drvdata(dev);
1090 	struct sci_port *sci = to_sci_port(port);
1091 	int ret;
1092 	long r;
1093 
1094 	ret = kstrtol(buf, 0, &r);
1095 	if (ret)
1096 		return ret;
1097 
1098 	sci->rx_trigger = scif_set_rtrg(port, r);
1099 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1100 		scif_set_rtrg(port, 1);
1101 
1102 	return count;
1103 }
1104 
1105 static DEVICE_ATTR(rx_fifo_trigger, 0644, rx_trigger_show, rx_trigger_store);
1106 
1107 static ssize_t rx_fifo_timeout_show(struct device *dev,
1108 			       struct device_attribute *attr,
1109 			       char *buf)
1110 {
1111 	struct uart_port *port = dev_get_drvdata(dev);
1112 	struct sci_port *sci = to_sci_port(port);
1113 	int v;
1114 
1115 	if (port->type == PORT_HSCIF)
1116 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1117 	else
1118 		v = sci->rx_fifo_timeout;
1119 
1120 	return sprintf(buf, "%d\n", v);
1121 }
1122 
1123 static ssize_t rx_fifo_timeout_store(struct device *dev,
1124 				struct device_attribute *attr,
1125 				const char *buf,
1126 				size_t count)
1127 {
1128 	struct uart_port *port = dev_get_drvdata(dev);
1129 	struct sci_port *sci = to_sci_port(port);
1130 	int ret;
1131 	long r;
1132 
1133 	ret = kstrtol(buf, 0, &r);
1134 	if (ret)
1135 		return ret;
1136 
1137 	if (port->type == PORT_HSCIF) {
1138 		if (r < 0 || r > 3)
1139 			return -EINVAL;
1140 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1141 	} else {
1142 		sci->rx_fifo_timeout = r;
1143 		scif_set_rtrg(port, 1);
1144 		if (r > 0)
1145 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1146 	}
1147 
1148 	return count;
1149 }
1150 
1151 static DEVICE_ATTR_RW(rx_fifo_timeout);
1152 
1153 
1154 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1155 static void sci_dma_tx_complete(void *arg)
1156 {
1157 	struct sci_port *s = arg;
1158 	struct uart_port *port = &s->port;
1159 	struct circ_buf *xmit = &port->state->xmit;
1160 	unsigned long flags;
1161 
1162 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1163 
1164 	spin_lock_irqsave(&port->lock, flags);
1165 
1166 	xmit->tail += s->tx_dma_len;
1167 	xmit->tail &= UART_XMIT_SIZE - 1;
1168 
1169 	port->icount.tx += s->tx_dma_len;
1170 
1171 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1172 		uart_write_wakeup(port);
1173 
1174 	if (!uart_circ_empty(xmit)) {
1175 		s->cookie_tx = 0;
1176 		schedule_work(&s->work_tx);
1177 	} else {
1178 		s->cookie_tx = -EINVAL;
1179 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1180 			u16 ctrl = serial_port_in(port, SCSCR);
1181 			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1182 		}
1183 	}
1184 
1185 	spin_unlock_irqrestore(&port->lock, flags);
1186 }
1187 
1188 /* Locking: called with port lock held */
1189 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1190 {
1191 	struct uart_port *port = &s->port;
1192 	struct tty_port *tport = &port->state->port;
1193 	int copied;
1194 
1195 	copied = tty_insert_flip_string(tport, buf, count);
1196 	if (copied < count)
1197 		port->icount.buf_overrun++;
1198 
1199 	port->icount.rx += copied;
1200 
1201 	return copied;
1202 }
1203 
1204 static int sci_dma_rx_find_active(struct sci_port *s)
1205 {
1206 	unsigned int i;
1207 
1208 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1209 		if (s->active_rx == s->cookie_rx[i])
1210 			return i;
1211 
1212 	return -1;
1213 }
1214 
1215 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1216 {
1217 	struct dma_chan *chan = s->chan_rx;
1218 	struct uart_port *port = &s->port;
1219 	unsigned long flags;
1220 
1221 	spin_lock_irqsave(&port->lock, flags);
1222 	s->chan_rx = NULL;
1223 	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1224 	spin_unlock_irqrestore(&port->lock, flags);
1225 	dmaengine_terminate_all(chan);
1226 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1227 			  sg_dma_address(&s->sg_rx[0]));
1228 	dma_release_channel(chan);
1229 	if (enable_pio) {
1230 		spin_lock_irqsave(&port->lock, flags);
1231 		sci_start_rx(port);
1232 		spin_unlock_irqrestore(&port->lock, flags);
1233 	}
1234 }
1235 
1236 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1237 {
1238 	long sec = usec / 1000000;
1239 	long nsec = (usec % 1000000) * 1000;
1240 	ktime_t t = ktime_set(sec, nsec);
1241 
1242 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1243 }
1244 
1245 static void sci_dma_rx_complete(void *arg)
1246 {
1247 	struct sci_port *s = arg;
1248 	struct dma_chan *chan = s->chan_rx;
1249 	struct uart_port *port = &s->port;
1250 	struct dma_async_tx_descriptor *desc;
1251 	unsigned long flags;
1252 	int active, count = 0;
1253 
1254 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1255 		s->active_rx);
1256 
1257 	spin_lock_irqsave(&port->lock, flags);
1258 
1259 	active = sci_dma_rx_find_active(s);
1260 	if (active >= 0)
1261 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1262 
1263 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1264 
1265 	if (count)
1266 		tty_flip_buffer_push(&port->state->port);
1267 
1268 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1269 				       DMA_DEV_TO_MEM,
1270 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1271 	if (!desc)
1272 		goto fail;
1273 
1274 	desc->callback = sci_dma_rx_complete;
1275 	desc->callback_param = s;
1276 	s->cookie_rx[active] = dmaengine_submit(desc);
1277 	if (dma_submit_error(s->cookie_rx[active]))
1278 		goto fail;
1279 
1280 	s->active_rx = s->cookie_rx[!active];
1281 
1282 	dma_async_issue_pending(chan);
1283 
1284 	spin_unlock_irqrestore(&port->lock, flags);
1285 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1286 		__func__, s->cookie_rx[active], active, s->active_rx);
1287 	return;
1288 
1289 fail:
1290 	spin_unlock_irqrestore(&port->lock, flags);
1291 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1292 	sci_rx_dma_release(s, true);
1293 }
1294 
1295 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1296 {
1297 	struct dma_chan *chan = s->chan_tx;
1298 	struct uart_port *port = &s->port;
1299 	unsigned long flags;
1300 
1301 	spin_lock_irqsave(&port->lock, flags);
1302 	s->chan_tx = NULL;
1303 	s->cookie_tx = -EINVAL;
1304 	spin_unlock_irqrestore(&port->lock, flags);
1305 	dmaengine_terminate_all(chan);
1306 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1307 			 DMA_TO_DEVICE);
1308 	dma_release_channel(chan);
1309 	if (enable_pio) {
1310 		spin_lock_irqsave(&port->lock, flags);
1311 		sci_start_tx(port);
1312 		spin_unlock_irqrestore(&port->lock, flags);
1313 	}
1314 }
1315 
1316 static void sci_submit_rx(struct sci_port *s)
1317 {
1318 	struct dma_chan *chan = s->chan_rx;
1319 	int i;
1320 
1321 	for (i = 0; i < 2; i++) {
1322 		struct scatterlist *sg = &s->sg_rx[i];
1323 		struct dma_async_tx_descriptor *desc;
1324 
1325 		desc = dmaengine_prep_slave_sg(chan,
1326 			sg, 1, DMA_DEV_TO_MEM,
1327 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1328 		if (!desc)
1329 			goto fail;
1330 
1331 		desc->callback = sci_dma_rx_complete;
1332 		desc->callback_param = s;
1333 		s->cookie_rx[i] = dmaengine_submit(desc);
1334 		if (dma_submit_error(s->cookie_rx[i]))
1335 			goto fail;
1336 
1337 	}
1338 
1339 	s->active_rx = s->cookie_rx[0];
1340 
1341 	dma_async_issue_pending(chan);
1342 	return;
1343 
1344 fail:
1345 	if (i)
1346 		dmaengine_terminate_all(chan);
1347 	for (i = 0; i < 2; i++)
1348 		s->cookie_rx[i] = -EINVAL;
1349 	s->active_rx = -EINVAL;
1350 	sci_rx_dma_release(s, true);
1351 }
1352 
1353 static void work_fn_tx(struct work_struct *work)
1354 {
1355 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1356 	struct dma_async_tx_descriptor *desc;
1357 	struct dma_chan *chan = s->chan_tx;
1358 	struct uart_port *port = &s->port;
1359 	struct circ_buf *xmit = &port->state->xmit;
1360 	dma_addr_t buf;
1361 
1362 	/*
1363 	 * DMA is idle now.
1364 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1365 	 * offsets and lengths. Since it is a circular buffer, we have to
1366 	 * transmit till the end, and then the rest. Take the port lock to get a
1367 	 * consistent xmit buffer state.
1368 	 */
1369 	spin_lock_irq(&port->lock);
1370 	buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1371 	s->tx_dma_len = min_t(unsigned int,
1372 		CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1373 		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1374 	spin_unlock_irq(&port->lock);
1375 
1376 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1377 					   DMA_MEM_TO_DEV,
1378 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1379 	if (!desc) {
1380 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1381 		/* switch to PIO */
1382 		sci_tx_dma_release(s, true);
1383 		return;
1384 	}
1385 
1386 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1387 				   DMA_TO_DEVICE);
1388 
1389 	spin_lock_irq(&port->lock);
1390 	desc->callback = sci_dma_tx_complete;
1391 	desc->callback_param = s;
1392 	spin_unlock_irq(&port->lock);
1393 	s->cookie_tx = dmaengine_submit(desc);
1394 	if (dma_submit_error(s->cookie_tx)) {
1395 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1396 		/* switch to PIO */
1397 		sci_tx_dma_release(s, true);
1398 		return;
1399 	}
1400 
1401 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1402 		__func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1403 
1404 	dma_async_issue_pending(chan);
1405 }
1406 
1407 static enum hrtimer_restart rx_timer_fn(struct hrtimer *t)
1408 {
1409 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1410 	struct dma_chan *chan = s->chan_rx;
1411 	struct uart_port *port = &s->port;
1412 	struct dma_tx_state state;
1413 	enum dma_status status;
1414 	unsigned long flags;
1415 	unsigned int read;
1416 	int active, count;
1417 	u16 scr;
1418 
1419 	dev_dbg(port->dev, "DMA Rx timed out\n");
1420 
1421 	spin_lock_irqsave(&port->lock, flags);
1422 
1423 	active = sci_dma_rx_find_active(s);
1424 	if (active < 0) {
1425 		spin_unlock_irqrestore(&port->lock, flags);
1426 		return HRTIMER_NORESTART;
1427 	}
1428 
1429 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1430 	if (status == DMA_COMPLETE) {
1431 		spin_unlock_irqrestore(&port->lock, flags);
1432 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1433 			s->active_rx, active);
1434 
1435 		/* Let packet complete handler take care of the packet */
1436 		return HRTIMER_NORESTART;
1437 	}
1438 
1439 	dmaengine_pause(chan);
1440 
1441 	/*
1442 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1443 	 * data keeps on coming until transaction is complete so check
1444 	 * for DMA_COMPLETE again
1445 	 * Let packet complete handler take care of the packet
1446 	 */
1447 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1448 	if (status == DMA_COMPLETE) {
1449 		spin_unlock_irqrestore(&port->lock, flags);
1450 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1451 		return HRTIMER_NORESTART;
1452 	}
1453 
1454 	/* Handle incomplete DMA receive */
1455 	dmaengine_terminate_all(s->chan_rx);
1456 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1457 
1458 	if (read) {
1459 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1460 		if (count)
1461 			tty_flip_buffer_push(&port->state->port);
1462 	}
1463 
1464 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1465 		sci_submit_rx(s);
1466 
1467 	/* Direct new serial port interrupts back to CPU */
1468 	scr = serial_port_in(port, SCSCR);
1469 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1470 		scr &= ~SCSCR_RDRQE;
1471 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1472 	}
1473 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1474 
1475 	spin_unlock_irqrestore(&port->lock, flags);
1476 
1477 	return HRTIMER_NORESTART;
1478 }
1479 
1480 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1481 					     enum dma_transfer_direction dir)
1482 {
1483 	struct dma_chan *chan;
1484 	struct dma_slave_config cfg;
1485 	int ret;
1486 
1487 	chan = dma_request_slave_channel(port->dev,
1488 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1489 	if (!chan) {
1490 		dev_warn(port->dev, "dma_request_slave_channel failed\n");
1491 		return NULL;
1492 	}
1493 
1494 	memset(&cfg, 0, sizeof(cfg));
1495 	cfg.direction = dir;
1496 	if (dir == DMA_MEM_TO_DEV) {
1497 		cfg.dst_addr = port->mapbase +
1498 			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1499 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1500 	} else {
1501 		cfg.src_addr = port->mapbase +
1502 			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1503 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1504 	}
1505 
1506 	ret = dmaengine_slave_config(chan, &cfg);
1507 	if (ret) {
1508 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1509 		dma_release_channel(chan);
1510 		return NULL;
1511 	}
1512 
1513 	return chan;
1514 }
1515 
1516 static void sci_request_dma(struct uart_port *port)
1517 {
1518 	struct sci_port *s = to_sci_port(port);
1519 	struct dma_chan *chan;
1520 
1521 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1522 
1523 	if (!port->dev->of_node)
1524 		return;
1525 
1526 	s->cookie_tx = -EINVAL;
1527 
1528 	/*
1529 	 * Don't request a dma channel if no channel was specified
1530 	 * in the device tree.
1531 	 */
1532 	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1533 		return;
1534 
1535 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1536 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1537 	if (chan) {
1538 		s->chan_tx = chan;
1539 		/* UART circular tx buffer is an aligned page. */
1540 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1541 						port->state->xmit.buf,
1542 						UART_XMIT_SIZE,
1543 						DMA_TO_DEVICE);
1544 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1545 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1546 			dma_release_channel(chan);
1547 			s->chan_tx = NULL;
1548 		} else {
1549 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1550 				__func__, UART_XMIT_SIZE,
1551 				port->state->xmit.buf, &s->tx_dma_addr);
1552 		}
1553 
1554 		INIT_WORK(&s->work_tx, work_fn_tx);
1555 	}
1556 
1557 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1558 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1559 	if (chan) {
1560 		unsigned int i;
1561 		dma_addr_t dma;
1562 		void *buf;
1563 
1564 		s->chan_rx = chan;
1565 
1566 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1567 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1568 					 &dma, GFP_KERNEL);
1569 		if (!buf) {
1570 			dev_warn(port->dev,
1571 				 "Failed to allocate Rx dma buffer, using PIO\n");
1572 			dma_release_channel(chan);
1573 			s->chan_rx = NULL;
1574 			return;
1575 		}
1576 
1577 		for (i = 0; i < 2; i++) {
1578 			struct scatterlist *sg = &s->sg_rx[i];
1579 
1580 			sg_init_table(sg, 1);
1581 			s->rx_buf[i] = buf;
1582 			sg_dma_address(sg) = dma;
1583 			sg_dma_len(sg) = s->buf_len_rx;
1584 
1585 			buf += s->buf_len_rx;
1586 			dma += s->buf_len_rx;
1587 		}
1588 
1589 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1590 		s->rx_timer.function = rx_timer_fn;
1591 
1592 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1593 			sci_submit_rx(s);
1594 	}
1595 }
1596 
1597 static void sci_free_dma(struct uart_port *port)
1598 {
1599 	struct sci_port *s = to_sci_port(port);
1600 
1601 	if (s->chan_tx)
1602 		sci_tx_dma_release(s, false);
1603 	if (s->chan_rx)
1604 		sci_rx_dma_release(s, false);
1605 }
1606 
1607 static void sci_flush_buffer(struct uart_port *port)
1608 {
1609 	/*
1610 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1611 	 * cleared, so we have to reset tx_dma_len accordingly.
1612 	 */
1613 	to_sci_port(port)->tx_dma_len = 0;
1614 }
1615 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1616 static inline void sci_request_dma(struct uart_port *port)
1617 {
1618 }
1619 
1620 static inline void sci_free_dma(struct uart_port *port)
1621 {
1622 }
1623 
1624 #define sci_flush_buffer	NULL
1625 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1626 
1627 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1628 {
1629 	struct uart_port *port = ptr;
1630 	struct sci_port *s = to_sci_port(port);
1631 
1632 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1633 	if (s->chan_rx) {
1634 		u16 scr = serial_port_in(port, SCSCR);
1635 		u16 ssr = serial_port_in(port, SCxSR);
1636 
1637 		/* Disable future Rx interrupts */
1638 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1639 			disable_irq_nosync(irq);
1640 			scr |= SCSCR_RDRQE;
1641 		} else {
1642 			scr &= ~SCSCR_RIE;
1643 			sci_submit_rx(s);
1644 		}
1645 		serial_port_out(port, SCSCR, scr);
1646 		/* Clear current interrupt */
1647 		serial_port_out(port, SCxSR,
1648 				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1649 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1650 			jiffies, s->rx_timeout);
1651 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1652 
1653 		return IRQ_HANDLED;
1654 	}
1655 #endif
1656 
1657 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1658 		if (!scif_rtrg_enabled(port))
1659 			scif_set_rtrg(port, s->rx_trigger);
1660 
1661 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1662 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1663 	}
1664 
1665 	/* I think sci_receive_chars has to be called irrespective
1666 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1667 	 * to be disabled?
1668 	 */
1669 	sci_receive_chars(ptr);
1670 
1671 	return IRQ_HANDLED;
1672 }
1673 
1674 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1675 {
1676 	struct uart_port *port = ptr;
1677 	unsigned long flags;
1678 
1679 	spin_lock_irqsave(&port->lock, flags);
1680 	sci_transmit_chars(port);
1681 	spin_unlock_irqrestore(&port->lock, flags);
1682 
1683 	return IRQ_HANDLED;
1684 }
1685 
1686 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1687 {
1688 	struct uart_port *port = ptr;
1689 	struct sci_port *s = to_sci_port(port);
1690 
1691 	/* Handle errors */
1692 	if (port->type == PORT_SCI) {
1693 		if (sci_handle_errors(port)) {
1694 			/* discard character in rx buffer */
1695 			serial_port_in(port, SCxSR);
1696 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1697 		}
1698 	} else {
1699 		sci_handle_fifo_overrun(port);
1700 		if (!s->chan_rx)
1701 			sci_receive_chars(ptr);
1702 	}
1703 
1704 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1705 
1706 	/* Kick the transmission */
1707 	if (!s->chan_tx)
1708 		sci_tx_interrupt(irq, ptr);
1709 
1710 	return IRQ_HANDLED;
1711 }
1712 
1713 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1714 {
1715 	struct uart_port *port = ptr;
1716 
1717 	/* Handle BREAKs */
1718 	sci_handle_breaks(port);
1719 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1720 
1721 	return IRQ_HANDLED;
1722 }
1723 
1724 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1725 {
1726 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1727 	struct uart_port *port = ptr;
1728 	struct sci_port *s = to_sci_port(port);
1729 	irqreturn_t ret = IRQ_NONE;
1730 
1731 	ssr_status = serial_port_in(port, SCxSR);
1732 	scr_status = serial_port_in(port, SCSCR);
1733 	if (s->params->overrun_reg == SCxSR)
1734 		orer_status = ssr_status;
1735 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1736 		orer_status = serial_port_in(port, s->params->overrun_reg);
1737 
1738 	err_enabled = scr_status & port_rx_irq_mask(port);
1739 
1740 	/* Tx Interrupt */
1741 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1742 	    !s->chan_tx)
1743 		ret = sci_tx_interrupt(irq, ptr);
1744 
1745 	/*
1746 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1747 	 * DR flags
1748 	 */
1749 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1750 	    (scr_status & SCSCR_RIE))
1751 		ret = sci_rx_interrupt(irq, ptr);
1752 
1753 	/* Error Interrupt */
1754 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1755 		ret = sci_er_interrupt(irq, ptr);
1756 
1757 	/* Break Interrupt */
1758 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1759 		ret = sci_br_interrupt(irq, ptr);
1760 
1761 	/* Overrun Interrupt */
1762 	if (orer_status & s->params->overrun_mask) {
1763 		sci_handle_fifo_overrun(port);
1764 		ret = IRQ_HANDLED;
1765 	}
1766 
1767 	return ret;
1768 }
1769 
1770 static const struct sci_irq_desc {
1771 	const char	*desc;
1772 	irq_handler_t	handler;
1773 } sci_irq_desc[] = {
1774 	/*
1775 	 * Split out handlers, the default case.
1776 	 */
1777 	[SCIx_ERI_IRQ] = {
1778 		.desc = "rx err",
1779 		.handler = sci_er_interrupt,
1780 	},
1781 
1782 	[SCIx_RXI_IRQ] = {
1783 		.desc = "rx full",
1784 		.handler = sci_rx_interrupt,
1785 	},
1786 
1787 	[SCIx_TXI_IRQ] = {
1788 		.desc = "tx empty",
1789 		.handler = sci_tx_interrupt,
1790 	},
1791 
1792 	[SCIx_BRI_IRQ] = {
1793 		.desc = "break",
1794 		.handler = sci_br_interrupt,
1795 	},
1796 
1797 	/*
1798 	 * Special muxed handler.
1799 	 */
1800 	[SCIx_MUX_IRQ] = {
1801 		.desc = "mux",
1802 		.handler = sci_mpxed_interrupt,
1803 	},
1804 };
1805 
1806 static int sci_request_irq(struct sci_port *port)
1807 {
1808 	struct uart_port *up = &port->port;
1809 	int i, j, ret = 0;
1810 
1811 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1812 		const struct sci_irq_desc *desc;
1813 		int irq;
1814 
1815 		if (SCIx_IRQ_IS_MUXED(port)) {
1816 			i = SCIx_MUX_IRQ;
1817 			irq = up->irq;
1818 		} else {
1819 			irq = port->irqs[i];
1820 
1821 			/*
1822 			 * Certain port types won't support all of the
1823 			 * available interrupt sources.
1824 			 */
1825 			if (unlikely(irq < 0))
1826 				continue;
1827 		}
1828 
1829 		desc = sci_irq_desc + i;
1830 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1831 					    dev_name(up->dev), desc->desc);
1832 		if (!port->irqstr[j]) {
1833 			ret = -ENOMEM;
1834 			goto out_nomem;
1835 		}
1836 
1837 		ret = request_irq(irq, desc->handler, up->irqflags,
1838 				  port->irqstr[j], port);
1839 		if (unlikely(ret)) {
1840 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1841 			goto out_noirq;
1842 		}
1843 	}
1844 
1845 	return 0;
1846 
1847 out_noirq:
1848 	while (--i >= 0)
1849 		free_irq(port->irqs[i], port);
1850 
1851 out_nomem:
1852 	while (--j >= 0)
1853 		kfree(port->irqstr[j]);
1854 
1855 	return ret;
1856 }
1857 
1858 static void sci_free_irq(struct sci_port *port)
1859 {
1860 	int i;
1861 
1862 	/*
1863 	 * Intentionally in reverse order so we iterate over the muxed
1864 	 * IRQ first.
1865 	 */
1866 	for (i = 0; i < SCIx_NR_IRQS; i++) {
1867 		int irq = port->irqs[i];
1868 
1869 		/*
1870 		 * Certain port types won't support all of the available
1871 		 * interrupt sources.
1872 		 */
1873 		if (unlikely(irq < 0))
1874 			continue;
1875 
1876 		free_irq(port->irqs[i], port);
1877 		kfree(port->irqstr[i]);
1878 
1879 		if (SCIx_IRQ_IS_MUXED(port)) {
1880 			/* If there's only one IRQ, we're done. */
1881 			return;
1882 		}
1883 	}
1884 }
1885 
1886 static unsigned int sci_tx_empty(struct uart_port *port)
1887 {
1888 	unsigned short status = serial_port_in(port, SCxSR);
1889 	unsigned short in_tx_fifo = sci_txfill(port);
1890 
1891 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1892 }
1893 
1894 static void sci_set_rts(struct uart_port *port, bool state)
1895 {
1896 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1897 		u16 data = serial_port_in(port, SCPDR);
1898 
1899 		/* Active low */
1900 		if (state)
1901 			data &= ~SCPDR_RTSD;
1902 		else
1903 			data |= SCPDR_RTSD;
1904 		serial_port_out(port, SCPDR, data);
1905 
1906 		/* RTS# is output */
1907 		serial_port_out(port, SCPCR,
1908 				serial_port_in(port, SCPCR) | SCPCR_RTSC);
1909 	} else if (sci_getreg(port, SCSPTR)->size) {
1910 		u16 ctrl = serial_port_in(port, SCSPTR);
1911 
1912 		/* Active low */
1913 		if (state)
1914 			ctrl &= ~SCSPTR_RTSDT;
1915 		else
1916 			ctrl |= SCSPTR_RTSDT;
1917 		serial_port_out(port, SCSPTR, ctrl);
1918 	}
1919 }
1920 
1921 static bool sci_get_cts(struct uart_port *port)
1922 {
1923 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1924 		/* Active low */
1925 		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
1926 	} else if (sci_getreg(port, SCSPTR)->size) {
1927 		/* Active low */
1928 		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
1929 	}
1930 
1931 	return true;
1932 }
1933 
1934 /*
1935  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1936  * CTS/RTS is supported in hardware by at least one port and controlled
1937  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1938  * handled via the ->init_pins() op, which is a bit of a one-way street,
1939  * lacking any ability to defer pin control -- this will later be
1940  * converted over to the GPIO framework).
1941  *
1942  * Other modes (such as loopback) are supported generically on certain
1943  * port types, but not others. For these it's sufficient to test for the
1944  * existence of the support register and simply ignore the port type.
1945  */
1946 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1947 {
1948 	struct sci_port *s = to_sci_port(port);
1949 
1950 	if (mctrl & TIOCM_LOOP) {
1951 		const struct plat_sci_reg *reg;
1952 
1953 		/*
1954 		 * Standard loopback mode for SCFCR ports.
1955 		 */
1956 		reg = sci_getreg(port, SCFCR);
1957 		if (reg->size)
1958 			serial_port_out(port, SCFCR,
1959 					serial_port_in(port, SCFCR) |
1960 					SCFCR_LOOP);
1961 	}
1962 
1963 	mctrl_gpio_set(s->gpios, mctrl);
1964 
1965 	if (!s->has_rtscts)
1966 		return;
1967 
1968 	if (!(mctrl & TIOCM_RTS)) {
1969 		/* Disable Auto RTS */
1970 		serial_port_out(port, SCFCR,
1971 				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
1972 
1973 		/* Clear RTS */
1974 		sci_set_rts(port, 0);
1975 	} else if (s->autorts) {
1976 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1977 			/* Enable RTS# pin function */
1978 			serial_port_out(port, SCPCR,
1979 				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
1980 		}
1981 
1982 		/* Enable Auto RTS */
1983 		serial_port_out(port, SCFCR,
1984 				serial_port_in(port, SCFCR) | SCFCR_MCE);
1985 	} else {
1986 		/* Set RTS */
1987 		sci_set_rts(port, 1);
1988 	}
1989 }
1990 
1991 static unsigned int sci_get_mctrl(struct uart_port *port)
1992 {
1993 	struct sci_port *s = to_sci_port(port);
1994 	struct mctrl_gpios *gpios = s->gpios;
1995 	unsigned int mctrl = 0;
1996 
1997 	mctrl_gpio_get(gpios, &mctrl);
1998 
1999 	/*
2000 	 * CTS/RTS is handled in hardware when supported, while nothing
2001 	 * else is wired up.
2002 	 */
2003 	if (s->autorts) {
2004 		if (sci_get_cts(port))
2005 			mctrl |= TIOCM_CTS;
2006 	} else if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS))) {
2007 		mctrl |= TIOCM_CTS;
2008 	}
2009 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))
2010 		mctrl |= TIOCM_DSR;
2011 	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))
2012 		mctrl |= TIOCM_CAR;
2013 
2014 	return mctrl;
2015 }
2016 
2017 static void sci_enable_ms(struct uart_port *port)
2018 {
2019 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2020 }
2021 
2022 static void sci_break_ctl(struct uart_port *port, int break_state)
2023 {
2024 	unsigned short scscr, scsptr;
2025 	unsigned long flags;
2026 
2027 	/* check wheter the port has SCSPTR */
2028 	if (!sci_getreg(port, SCSPTR)->size) {
2029 		/*
2030 		 * Not supported by hardware. Most parts couple break and rx
2031 		 * interrupts together, with break detection always enabled.
2032 		 */
2033 		return;
2034 	}
2035 
2036 	spin_lock_irqsave(&port->lock, flags);
2037 	scsptr = serial_port_in(port, SCSPTR);
2038 	scscr = serial_port_in(port, SCSCR);
2039 
2040 	if (break_state == -1) {
2041 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2042 		scscr &= ~SCSCR_TE;
2043 	} else {
2044 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2045 		scscr |= SCSCR_TE;
2046 	}
2047 
2048 	serial_port_out(port, SCSPTR, scsptr);
2049 	serial_port_out(port, SCSCR, scscr);
2050 	spin_unlock_irqrestore(&port->lock, flags);
2051 }
2052 
2053 static int sci_startup(struct uart_port *port)
2054 {
2055 	struct sci_port *s = to_sci_port(port);
2056 	int ret;
2057 
2058 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2059 
2060 	sci_request_dma(port);
2061 
2062 	ret = sci_request_irq(s);
2063 	if (unlikely(ret < 0)) {
2064 		sci_free_dma(port);
2065 		return ret;
2066 	}
2067 
2068 	return 0;
2069 }
2070 
2071 static void sci_shutdown(struct uart_port *port)
2072 {
2073 	struct sci_port *s = to_sci_port(port);
2074 	unsigned long flags;
2075 	u16 scr;
2076 
2077 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2078 
2079 	s->autorts = false;
2080 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2081 
2082 	spin_lock_irqsave(&port->lock, flags);
2083 	sci_stop_rx(port);
2084 	sci_stop_tx(port);
2085 	/*
2086 	 * Stop RX and TX, disable related interrupts, keep clock source
2087 	 * and HSCIF TOT bits
2088 	 */
2089 	scr = serial_port_in(port, SCSCR);
2090 	serial_port_out(port, SCSCR, scr &
2091 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2092 	spin_unlock_irqrestore(&port->lock, flags);
2093 
2094 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2095 	if (s->chan_rx) {
2096 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2097 			port->line);
2098 		hrtimer_cancel(&s->rx_timer);
2099 	}
2100 #endif
2101 
2102 	sci_free_irq(s);
2103 	sci_free_dma(port);
2104 }
2105 
2106 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2107 			unsigned int *srr)
2108 {
2109 	unsigned long freq = s->clk_rates[SCI_SCK];
2110 	int err, min_err = INT_MAX;
2111 	unsigned int sr;
2112 
2113 	if (s->port.type != PORT_HSCIF)
2114 		freq *= 2;
2115 
2116 	for_each_sr(sr, s) {
2117 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2118 		if (abs(err) >= abs(min_err))
2119 			continue;
2120 
2121 		min_err = err;
2122 		*srr = sr - 1;
2123 
2124 		if (!err)
2125 			break;
2126 	}
2127 
2128 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2129 		*srr + 1);
2130 	return min_err;
2131 }
2132 
2133 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2134 			unsigned long freq, unsigned int *dlr,
2135 			unsigned int *srr)
2136 {
2137 	int err, min_err = INT_MAX;
2138 	unsigned int sr, dl;
2139 
2140 	if (s->port.type != PORT_HSCIF)
2141 		freq *= 2;
2142 
2143 	for_each_sr(sr, s) {
2144 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2145 		dl = clamp(dl, 1U, 65535U);
2146 
2147 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2148 		if (abs(err) >= abs(min_err))
2149 			continue;
2150 
2151 		min_err = err;
2152 		*dlr = dl;
2153 		*srr = sr - 1;
2154 
2155 		if (!err)
2156 			break;
2157 	}
2158 
2159 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2160 		min_err, *dlr, *srr + 1);
2161 	return min_err;
2162 }
2163 
2164 /* calculate sample rate, BRR, and clock select */
2165 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2166 			  unsigned int *brr, unsigned int *srr,
2167 			  unsigned int *cks)
2168 {
2169 	unsigned long freq = s->clk_rates[SCI_FCK];
2170 	unsigned int sr, br, prediv, scrate, c;
2171 	int err, min_err = INT_MAX;
2172 
2173 	if (s->port.type != PORT_HSCIF)
2174 		freq *= 2;
2175 
2176 	/*
2177 	 * Find the combination of sample rate and clock select with the
2178 	 * smallest deviation from the desired baud rate.
2179 	 * Prefer high sample rates to maximise the receive margin.
2180 	 *
2181 	 * M: Receive margin (%)
2182 	 * N: Ratio of bit rate to clock (N = sampling rate)
2183 	 * D: Clock duty (D = 0 to 1.0)
2184 	 * L: Frame length (L = 9 to 12)
2185 	 * F: Absolute value of clock frequency deviation
2186 	 *
2187 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2188 	 *      (|D - 0.5| / N * (1 + F))|
2189 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2190 	 */
2191 	for_each_sr(sr, s) {
2192 		for (c = 0; c <= 3; c++) {
2193 			/* integerized formulas from HSCIF documentation */
2194 			prediv = sr * (1 << (2 * c + 1));
2195 
2196 			/*
2197 			 * We need to calculate:
2198 			 *
2199 			 *     br = freq / (prediv * bps) clamped to [1..256]
2200 			 *     err = freq / (br * prediv) - bps
2201 			 *
2202 			 * Watch out for overflow when calculating the desired
2203 			 * sampling clock rate!
2204 			 */
2205 			if (bps > UINT_MAX / prediv)
2206 				break;
2207 
2208 			scrate = prediv * bps;
2209 			br = DIV_ROUND_CLOSEST(freq, scrate);
2210 			br = clamp(br, 1U, 256U);
2211 
2212 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2213 			if (abs(err) >= abs(min_err))
2214 				continue;
2215 
2216 			min_err = err;
2217 			*brr = br - 1;
2218 			*srr = sr - 1;
2219 			*cks = c;
2220 
2221 			if (!err)
2222 				goto found;
2223 		}
2224 	}
2225 
2226 found:
2227 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2228 		min_err, *brr, *srr + 1, *cks);
2229 	return min_err;
2230 }
2231 
2232 static void sci_reset(struct uart_port *port)
2233 {
2234 	const struct plat_sci_reg *reg;
2235 	unsigned int status;
2236 	struct sci_port *s = to_sci_port(port);
2237 
2238 	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2239 
2240 	reg = sci_getreg(port, SCFCR);
2241 	if (reg->size)
2242 		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2243 
2244 	sci_clear_SCxSR(port,
2245 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2246 			SCxSR_BREAK_CLEAR(port));
2247 	if (sci_getreg(port, SCLSR)->size) {
2248 		status = serial_port_in(port, SCLSR);
2249 		status &= ~(SCLSR_TO | SCLSR_ORER);
2250 		serial_port_out(port, SCLSR, status);
2251 	}
2252 
2253 	if (s->rx_trigger > 1) {
2254 		if (s->rx_fifo_timeout) {
2255 			scif_set_rtrg(port, 1);
2256 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2257 		} else {
2258 			if (port->type == PORT_SCIFA ||
2259 			    port->type == PORT_SCIFB)
2260 				scif_set_rtrg(port, 1);
2261 			else
2262 				scif_set_rtrg(port, s->rx_trigger);
2263 		}
2264 	}
2265 }
2266 
2267 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2268 			    struct ktermios *old)
2269 {
2270 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2271 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2272 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2273 	struct sci_port *s = to_sci_port(port);
2274 	const struct plat_sci_reg *reg;
2275 	int min_err = INT_MAX, err;
2276 	unsigned long max_freq = 0;
2277 	int best_clk = -1;
2278 	unsigned long flags;
2279 
2280 	if ((termios->c_cflag & CSIZE) == CS7)
2281 		smr_val |= SCSMR_CHR;
2282 	if (termios->c_cflag & PARENB)
2283 		smr_val |= SCSMR_PE;
2284 	if (termios->c_cflag & PARODD)
2285 		smr_val |= SCSMR_PE | SCSMR_ODD;
2286 	if (termios->c_cflag & CSTOPB)
2287 		smr_val |= SCSMR_STOP;
2288 
2289 	/*
2290 	 * earlyprintk comes here early on with port->uartclk set to zero.
2291 	 * the clock framework is not up and running at this point so here
2292 	 * we assume that 115200 is the maximum baud rate. please note that
2293 	 * the baud rate is not programmed during earlyprintk - it is assumed
2294 	 * that the previous boot loader has enabled required clocks and
2295 	 * setup the baud rate generator hardware for us already.
2296 	 */
2297 	if (!port->uartclk) {
2298 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2299 		goto done;
2300 	}
2301 
2302 	for (i = 0; i < SCI_NUM_CLKS; i++)
2303 		max_freq = max(max_freq, s->clk_rates[i]);
2304 
2305 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2306 	if (!baud)
2307 		goto done;
2308 
2309 	/*
2310 	 * There can be multiple sources for the sampling clock.  Find the one
2311 	 * that gives us the smallest deviation from the desired baud rate.
2312 	 */
2313 
2314 	/* Optional Undivided External Clock */
2315 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2316 	    port->type != PORT_SCIFB) {
2317 		err = sci_sck_calc(s, baud, &srr1);
2318 		if (abs(err) < abs(min_err)) {
2319 			best_clk = SCI_SCK;
2320 			scr_val = SCSCR_CKE1;
2321 			sccks = SCCKS_CKS;
2322 			min_err = err;
2323 			srr = srr1;
2324 			if (!err)
2325 				goto done;
2326 		}
2327 	}
2328 
2329 	/* Optional BRG Frequency Divided External Clock */
2330 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2331 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2332 				   &srr1);
2333 		if (abs(err) < abs(min_err)) {
2334 			best_clk = SCI_SCIF_CLK;
2335 			scr_val = SCSCR_CKE1;
2336 			sccks = 0;
2337 			min_err = err;
2338 			dl = dl1;
2339 			srr = srr1;
2340 			if (!err)
2341 				goto done;
2342 		}
2343 	}
2344 
2345 	/* Optional BRG Frequency Divided Internal Clock */
2346 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2347 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2348 				   &srr1);
2349 		if (abs(err) < abs(min_err)) {
2350 			best_clk = SCI_BRG_INT;
2351 			scr_val = SCSCR_CKE1;
2352 			sccks = SCCKS_XIN;
2353 			min_err = err;
2354 			dl = dl1;
2355 			srr = srr1;
2356 			if (!min_err)
2357 				goto done;
2358 		}
2359 	}
2360 
2361 	/* Divided Functional Clock using standard Bit Rate Register */
2362 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2363 	if (abs(err) < abs(min_err)) {
2364 		best_clk = SCI_FCK;
2365 		scr_val = 0;
2366 		min_err = err;
2367 		brr = brr1;
2368 		srr = srr1;
2369 		cks = cks1;
2370 	}
2371 
2372 done:
2373 	if (best_clk >= 0)
2374 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2375 			s->clks[best_clk], baud, min_err);
2376 
2377 	sci_port_enable(s);
2378 
2379 	/*
2380 	 * Program the optional External Baud Rate Generator (BRG) first.
2381 	 * It controls the mux to select (H)SCK or frequency divided clock.
2382 	 */
2383 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2384 		serial_port_out(port, SCDL, dl);
2385 		serial_port_out(port, SCCKS, sccks);
2386 	}
2387 
2388 	spin_lock_irqsave(&port->lock, flags);
2389 
2390 	sci_reset(port);
2391 
2392 	uart_update_timeout(port, termios->c_cflag, baud);
2393 
2394 	/* byte size and parity */
2395 	switch (termios->c_cflag & CSIZE) {
2396 	case CS5:
2397 		bits = 7;
2398 		break;
2399 	case CS6:
2400 		bits = 8;
2401 		break;
2402 	case CS7:
2403 		bits = 9;
2404 		break;
2405 	default:
2406 		bits = 10;
2407 		break;
2408 	}
2409 
2410 	if (termios->c_cflag & CSTOPB)
2411 		bits++;
2412 	if (termios->c_cflag & PARENB)
2413 		bits++;
2414 
2415 	if (best_clk >= 0) {
2416 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2417 			switch (srr + 1) {
2418 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2419 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2420 			case 11: smr_val |= SCSMR_SRC_11; break;
2421 			case 13: smr_val |= SCSMR_SRC_13; break;
2422 			case 16: smr_val |= SCSMR_SRC_16; break;
2423 			case 17: smr_val |= SCSMR_SRC_17; break;
2424 			case 19: smr_val |= SCSMR_SRC_19; break;
2425 			case 27: smr_val |= SCSMR_SRC_27; break;
2426 			}
2427 		smr_val |= cks;
2428 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2429 		serial_port_out(port, SCSMR, smr_val);
2430 		serial_port_out(port, SCBRR, brr);
2431 		if (sci_getreg(port, HSSRR)->size) {
2432 			unsigned int hssrr = srr | HSCIF_SRE;
2433 			/* Calculate deviation from intended rate at the
2434 			 * center of the last stop bit in sampling clocks.
2435 			 */
2436 			int last_stop = bits * 2 - 1;
2437 			int deviation = min_err * srr * last_stop / 2 / baud;
2438 
2439 			if (abs(deviation) >= 2) {
2440 				/* At least two sampling clocks off at the
2441 				 * last stop bit; we can increase the error
2442 				 * margin by shifting the sampling point.
2443 				 */
2444 				int shift = min(-8, max(7, deviation / 2));
2445 
2446 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2447 					 HSCIF_SRHP_MASK;
2448 				hssrr |= HSCIF_SRDE;
2449 			}
2450 			serial_port_out(port, HSSRR, hssrr);
2451 		}
2452 
2453 		/* Wait one bit interval */
2454 		udelay((1000000 + (baud - 1)) / baud);
2455 	} else {
2456 		/* Don't touch the bit rate configuration */
2457 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2458 		smr_val |= serial_port_in(port, SCSMR) &
2459 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2460 		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2461 		serial_port_out(port, SCSMR, smr_val);
2462 	}
2463 
2464 	sci_init_pins(port, termios->c_cflag);
2465 
2466 	port->status &= ~UPSTAT_AUTOCTS;
2467 	s->autorts = false;
2468 	reg = sci_getreg(port, SCFCR);
2469 	if (reg->size) {
2470 		unsigned short ctrl = serial_port_in(port, SCFCR);
2471 
2472 		if ((port->flags & UPF_HARD_FLOW) &&
2473 		    (termios->c_cflag & CRTSCTS)) {
2474 			/* There is no CTS interrupt to restart the hardware */
2475 			port->status |= UPSTAT_AUTOCTS;
2476 			/* MCE is enabled when RTS is raised */
2477 			s->autorts = true;
2478 		}
2479 
2480 		/*
2481 		 * As we've done a sci_reset() above, ensure we don't
2482 		 * interfere with the FIFOs while toggling MCE. As the
2483 		 * reset values could still be set, simply mask them out.
2484 		 */
2485 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2486 
2487 		serial_port_out(port, SCFCR, ctrl);
2488 	}
2489 	if (port->flags & UPF_HARD_FLOW) {
2490 		/* Refresh (Auto) RTS */
2491 		sci_set_mctrl(port, port->mctrl);
2492 	}
2493 
2494 	scr_val |= SCSCR_RE | SCSCR_TE |
2495 		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2496 	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2497 	if ((srr + 1 == 5) &&
2498 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2499 		/*
2500 		 * In asynchronous mode, when the sampling rate is 1/5, first
2501 		 * received data may become invalid on some SCIFA and SCIFB.
2502 		 * To avoid this problem wait more than 1 serial data time (1
2503 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2504 		 */
2505 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2506 	}
2507 
2508 	/*
2509 	 * Calculate delay for 2 DMA buffers (4 FIFO).
2510 	 * See serial_core.c::uart_update_timeout().
2511 	 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2512 	 * function calculates 1 jiffie for the data plus 5 jiffies for the
2513 	 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2514 	 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2515 	 * value obtained by this formula is too small. Therefore, if the value
2516 	 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2517 	 */
2518 	s->rx_frame = (10000 * bits) / (baud / 100);
2519 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2520 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2521 	if (s->rx_timeout < 20)
2522 		s->rx_timeout = 20;
2523 #endif
2524 
2525 	if ((termios->c_cflag & CREAD) != 0)
2526 		sci_start_rx(port);
2527 
2528 	spin_unlock_irqrestore(&port->lock, flags);
2529 
2530 	sci_port_disable(s);
2531 
2532 	if (UART_ENABLE_MS(port, termios->c_cflag))
2533 		sci_enable_ms(port);
2534 }
2535 
2536 static void sci_pm(struct uart_port *port, unsigned int state,
2537 		   unsigned int oldstate)
2538 {
2539 	struct sci_port *sci_port = to_sci_port(port);
2540 
2541 	switch (state) {
2542 	case UART_PM_STATE_OFF:
2543 		sci_port_disable(sci_port);
2544 		break;
2545 	default:
2546 		sci_port_enable(sci_port);
2547 		break;
2548 	}
2549 }
2550 
2551 static const char *sci_type(struct uart_port *port)
2552 {
2553 	switch (port->type) {
2554 	case PORT_IRDA:
2555 		return "irda";
2556 	case PORT_SCI:
2557 		return "sci";
2558 	case PORT_SCIF:
2559 		return "scif";
2560 	case PORT_SCIFA:
2561 		return "scifa";
2562 	case PORT_SCIFB:
2563 		return "scifb";
2564 	case PORT_HSCIF:
2565 		return "hscif";
2566 	}
2567 
2568 	return NULL;
2569 }
2570 
2571 static int sci_remap_port(struct uart_port *port)
2572 {
2573 	struct sci_port *sport = to_sci_port(port);
2574 
2575 	/*
2576 	 * Nothing to do if there's already an established membase.
2577 	 */
2578 	if (port->membase)
2579 		return 0;
2580 
2581 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2582 		port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2583 		if (unlikely(!port->membase)) {
2584 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2585 			return -ENXIO;
2586 		}
2587 	} else {
2588 		/*
2589 		 * For the simple (and majority of) cases where we don't
2590 		 * need to do any remapping, just cast the cookie
2591 		 * directly.
2592 		 */
2593 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2594 	}
2595 
2596 	return 0;
2597 }
2598 
2599 static void sci_release_port(struct uart_port *port)
2600 {
2601 	struct sci_port *sport = to_sci_port(port);
2602 
2603 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2604 		iounmap(port->membase);
2605 		port->membase = NULL;
2606 	}
2607 
2608 	release_mem_region(port->mapbase, sport->reg_size);
2609 }
2610 
2611 static int sci_request_port(struct uart_port *port)
2612 {
2613 	struct resource *res;
2614 	struct sci_port *sport = to_sci_port(port);
2615 	int ret;
2616 
2617 	res = request_mem_region(port->mapbase, sport->reg_size,
2618 				 dev_name(port->dev));
2619 	if (unlikely(res == NULL)) {
2620 		dev_err(port->dev, "request_mem_region failed.");
2621 		return -EBUSY;
2622 	}
2623 
2624 	ret = sci_remap_port(port);
2625 	if (unlikely(ret != 0)) {
2626 		release_resource(res);
2627 		return ret;
2628 	}
2629 
2630 	return 0;
2631 }
2632 
2633 static void sci_config_port(struct uart_port *port, int flags)
2634 {
2635 	if (flags & UART_CONFIG_TYPE) {
2636 		struct sci_port *sport = to_sci_port(port);
2637 
2638 		port->type = sport->cfg->type;
2639 		sci_request_port(port);
2640 	}
2641 }
2642 
2643 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2644 {
2645 	if (ser->baud_base < 2400)
2646 		/* No paper tape reader for Mitch.. */
2647 		return -EINVAL;
2648 
2649 	return 0;
2650 }
2651 
2652 static const struct uart_ops sci_uart_ops = {
2653 	.tx_empty	= sci_tx_empty,
2654 	.set_mctrl	= sci_set_mctrl,
2655 	.get_mctrl	= sci_get_mctrl,
2656 	.start_tx	= sci_start_tx,
2657 	.stop_tx	= sci_stop_tx,
2658 	.stop_rx	= sci_stop_rx,
2659 	.enable_ms	= sci_enable_ms,
2660 	.break_ctl	= sci_break_ctl,
2661 	.startup	= sci_startup,
2662 	.shutdown	= sci_shutdown,
2663 	.flush_buffer	= sci_flush_buffer,
2664 	.set_termios	= sci_set_termios,
2665 	.pm		= sci_pm,
2666 	.type		= sci_type,
2667 	.release_port	= sci_release_port,
2668 	.request_port	= sci_request_port,
2669 	.config_port	= sci_config_port,
2670 	.verify_port	= sci_verify_port,
2671 #ifdef CONFIG_CONSOLE_POLL
2672 	.poll_get_char	= sci_poll_get_char,
2673 	.poll_put_char	= sci_poll_put_char,
2674 #endif
2675 };
2676 
2677 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2678 {
2679 	const char *clk_names[] = {
2680 		[SCI_FCK] = "fck",
2681 		[SCI_SCK] = "sck",
2682 		[SCI_BRG_INT] = "brg_int",
2683 		[SCI_SCIF_CLK] = "scif_clk",
2684 	};
2685 	struct clk *clk;
2686 	unsigned int i;
2687 
2688 	if (sci_port->cfg->type == PORT_HSCIF)
2689 		clk_names[SCI_SCK] = "hsck";
2690 
2691 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2692 		clk = devm_clk_get(dev, clk_names[i]);
2693 		if (PTR_ERR(clk) == -EPROBE_DEFER)
2694 			return -EPROBE_DEFER;
2695 
2696 		if (IS_ERR(clk) && i == SCI_FCK) {
2697 			/*
2698 			 * "fck" used to be called "sci_ick", and we need to
2699 			 * maintain DT backward compatibility.
2700 			 */
2701 			clk = devm_clk_get(dev, "sci_ick");
2702 			if (PTR_ERR(clk) == -EPROBE_DEFER)
2703 				return -EPROBE_DEFER;
2704 
2705 			if (!IS_ERR(clk))
2706 				goto found;
2707 
2708 			/*
2709 			 * Not all SH platforms declare a clock lookup entry
2710 			 * for SCI devices, in which case we need to get the
2711 			 * global "peripheral_clk" clock.
2712 			 */
2713 			clk = devm_clk_get(dev, "peripheral_clk");
2714 			if (!IS_ERR(clk))
2715 				goto found;
2716 
2717 			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2718 				PTR_ERR(clk));
2719 			return PTR_ERR(clk);
2720 		}
2721 
2722 found:
2723 		if (IS_ERR(clk))
2724 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2725 				PTR_ERR(clk));
2726 		else
2727 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2728 				clk, clk_get_rate(clk));
2729 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2730 	}
2731 	return 0;
2732 }
2733 
2734 static const struct sci_port_params *
2735 sci_probe_regmap(const struct plat_sci_port *cfg)
2736 {
2737 	unsigned int regtype;
2738 
2739 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2740 		return &sci_port_params[cfg->regtype];
2741 
2742 	switch (cfg->type) {
2743 	case PORT_SCI:
2744 		regtype = SCIx_SCI_REGTYPE;
2745 		break;
2746 	case PORT_IRDA:
2747 		regtype = SCIx_IRDA_REGTYPE;
2748 		break;
2749 	case PORT_SCIFA:
2750 		regtype = SCIx_SCIFA_REGTYPE;
2751 		break;
2752 	case PORT_SCIFB:
2753 		regtype = SCIx_SCIFB_REGTYPE;
2754 		break;
2755 	case PORT_SCIF:
2756 		/*
2757 		 * The SH-4 is a bit of a misnomer here, although that's
2758 		 * where this particular port layout originated. This
2759 		 * configuration (or some slight variation thereof)
2760 		 * remains the dominant model for all SCIFs.
2761 		 */
2762 		regtype = SCIx_SH4_SCIF_REGTYPE;
2763 		break;
2764 	case PORT_HSCIF:
2765 		regtype = SCIx_HSCIF_REGTYPE;
2766 		break;
2767 	default:
2768 		pr_err("Can't probe register map for given port\n");
2769 		return NULL;
2770 	}
2771 
2772 	return &sci_port_params[regtype];
2773 }
2774 
2775 static int sci_init_single(struct platform_device *dev,
2776 			   struct sci_port *sci_port, unsigned int index,
2777 			   const struct plat_sci_port *p, bool early)
2778 {
2779 	struct uart_port *port = &sci_port->port;
2780 	const struct resource *res;
2781 	unsigned int i;
2782 	int ret;
2783 
2784 	sci_port->cfg	= p;
2785 
2786 	port->ops	= &sci_uart_ops;
2787 	port->iotype	= UPIO_MEM;
2788 	port->line	= index;
2789 
2790 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2791 	if (res == NULL)
2792 		return -ENOMEM;
2793 
2794 	port->mapbase = res->start;
2795 	sci_port->reg_size = resource_size(res);
2796 
2797 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2798 		sci_port->irqs[i] = platform_get_irq(dev, i);
2799 
2800 	/* The SCI generates several interrupts. They can be muxed together or
2801 	 * connected to different interrupt lines. In the muxed case only one
2802 	 * interrupt resource is specified. In the non-muxed case three or four
2803 	 * interrupt resources are specified, as the BRI interrupt is optional.
2804 	 */
2805 	if (sci_port->irqs[0] < 0)
2806 		return -ENXIO;
2807 
2808 	if (sci_port->irqs[1] < 0) {
2809 		sci_port->irqs[1] = sci_port->irqs[0];
2810 		sci_port->irqs[2] = sci_port->irqs[0];
2811 		sci_port->irqs[3] = sci_port->irqs[0];
2812 	}
2813 
2814 	sci_port->params = sci_probe_regmap(p);
2815 	if (unlikely(sci_port->params == NULL))
2816 		return -EINVAL;
2817 
2818 	switch (p->type) {
2819 	case PORT_SCIFB:
2820 		sci_port->rx_trigger = 48;
2821 		break;
2822 	case PORT_HSCIF:
2823 		sci_port->rx_trigger = 64;
2824 		break;
2825 	case PORT_SCIFA:
2826 		sci_port->rx_trigger = 32;
2827 		break;
2828 	case PORT_SCIF:
2829 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2830 			/* RX triggering not implemented for this IP */
2831 			sci_port->rx_trigger = 1;
2832 		else
2833 			sci_port->rx_trigger = 8;
2834 		break;
2835 	default:
2836 		sci_port->rx_trigger = 1;
2837 		break;
2838 	}
2839 
2840 	sci_port->rx_fifo_timeout = 0;
2841 	sci_port->hscif_tot = 0;
2842 
2843 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2844 	 * match the SoC datasheet, this should be investigated. Let platform
2845 	 * data override the sampling rate for now.
2846 	 */
2847 	sci_port->sampling_rate_mask = p->sampling_rate
2848 				     ? SCI_SR(p->sampling_rate)
2849 				     : sci_port->params->sampling_rate_mask;
2850 
2851 	if (!early) {
2852 		ret = sci_init_clocks(sci_port, &dev->dev);
2853 		if (ret < 0)
2854 			return ret;
2855 
2856 		port->dev = &dev->dev;
2857 
2858 		pm_runtime_enable(&dev->dev);
2859 	}
2860 
2861 	port->type		= p->type;
2862 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2863 	port->fifosize		= sci_port->params->fifosize;
2864 
2865 	if (port->type == PORT_SCI) {
2866 		if (sci_port->reg_size >= 0x20)
2867 			port->regshift = 2;
2868 		else
2869 			port->regshift = 1;
2870 	}
2871 
2872 	/*
2873 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2874 	 * for the multi-IRQ ports, which is where we are primarily
2875 	 * concerned with the shutdown path synchronization.
2876 	 *
2877 	 * For the muxed case there's nothing more to do.
2878 	 */
2879 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2880 	port->irqflags		= 0;
2881 
2882 	port->serial_in		= sci_serial_in;
2883 	port->serial_out	= sci_serial_out;
2884 
2885 	return 0;
2886 }
2887 
2888 static void sci_cleanup_single(struct sci_port *port)
2889 {
2890 	pm_runtime_disable(port->port.dev);
2891 }
2892 
2893 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2894     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2895 static void serial_console_putchar(struct uart_port *port, int ch)
2896 {
2897 	sci_poll_put_char(port, ch);
2898 }
2899 
2900 /*
2901  *	Print a string to the serial port trying not to disturb
2902  *	any possible real use of the port...
2903  */
2904 static void serial_console_write(struct console *co, const char *s,
2905 				 unsigned count)
2906 {
2907 	struct sci_port *sci_port = &sci_ports[co->index];
2908 	struct uart_port *port = &sci_port->port;
2909 	unsigned short bits, ctrl, ctrl_temp;
2910 	unsigned long flags;
2911 	int locked = 1;
2912 
2913 #if defined(SUPPORT_SYSRQ)
2914 	if (port->sysrq)
2915 		locked = 0;
2916 	else
2917 #endif
2918 	if (oops_in_progress)
2919 		locked = spin_trylock_irqsave(&port->lock, flags);
2920 	else
2921 		spin_lock_irqsave(&port->lock, flags);
2922 
2923 	/* first save SCSCR then disable interrupts, keep clock source */
2924 	ctrl = serial_port_in(port, SCSCR);
2925 	ctrl_temp = SCSCR_RE | SCSCR_TE |
2926 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2927 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2928 	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
2929 
2930 	uart_console_write(port, s, count, serial_console_putchar);
2931 
2932 	/* wait until fifo is empty and last bit has been transmitted */
2933 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2934 	while ((serial_port_in(port, SCxSR) & bits) != bits)
2935 		cpu_relax();
2936 
2937 	/* restore the SCSCR */
2938 	serial_port_out(port, SCSCR, ctrl);
2939 
2940 	if (locked)
2941 		spin_unlock_irqrestore(&port->lock, flags);
2942 }
2943 
2944 static int serial_console_setup(struct console *co, char *options)
2945 {
2946 	struct sci_port *sci_port;
2947 	struct uart_port *port;
2948 	int baud = 115200;
2949 	int bits = 8;
2950 	int parity = 'n';
2951 	int flow = 'n';
2952 	int ret;
2953 
2954 	/*
2955 	 * Refuse to handle any bogus ports.
2956 	 */
2957 	if (co->index < 0 || co->index >= SCI_NPORTS)
2958 		return -ENODEV;
2959 
2960 	sci_port = &sci_ports[co->index];
2961 	port = &sci_port->port;
2962 
2963 	/*
2964 	 * Refuse to handle uninitialized ports.
2965 	 */
2966 	if (!port->ops)
2967 		return -ENODEV;
2968 
2969 	ret = sci_remap_port(port);
2970 	if (unlikely(ret != 0))
2971 		return ret;
2972 
2973 	if (options)
2974 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2975 
2976 	return uart_set_options(port, co, baud, parity, bits, flow);
2977 }
2978 
2979 static struct console serial_console = {
2980 	.name		= "ttySC",
2981 	.device		= uart_console_device,
2982 	.write		= serial_console_write,
2983 	.setup		= serial_console_setup,
2984 	.flags		= CON_PRINTBUFFER,
2985 	.index		= -1,
2986 	.data		= &sci_uart_driver,
2987 };
2988 
2989 static struct console early_serial_console = {
2990 	.name           = "early_ttySC",
2991 	.write          = serial_console_write,
2992 	.flags          = CON_PRINTBUFFER,
2993 	.index		= -1,
2994 };
2995 
2996 static char early_serial_buf[32];
2997 
2998 static int sci_probe_earlyprintk(struct platform_device *pdev)
2999 {
3000 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3001 
3002 	if (early_serial_console.data)
3003 		return -EEXIST;
3004 
3005 	early_serial_console.index = pdev->id;
3006 
3007 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3008 
3009 	serial_console_setup(&early_serial_console, early_serial_buf);
3010 
3011 	if (!strstr(early_serial_buf, "keep"))
3012 		early_serial_console.flags |= CON_BOOT;
3013 
3014 	register_console(&early_serial_console);
3015 	return 0;
3016 }
3017 
3018 #define SCI_CONSOLE	(&serial_console)
3019 
3020 #else
3021 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3022 {
3023 	return -EINVAL;
3024 }
3025 
3026 #define SCI_CONSOLE	NULL
3027 
3028 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3029 
3030 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3031 
3032 static DEFINE_MUTEX(sci_uart_registration_lock);
3033 static struct uart_driver sci_uart_driver = {
3034 	.owner		= THIS_MODULE,
3035 	.driver_name	= "sci",
3036 	.dev_name	= "ttySC",
3037 	.major		= SCI_MAJOR,
3038 	.minor		= SCI_MINOR_START,
3039 	.nr		= SCI_NPORTS,
3040 	.cons		= SCI_CONSOLE,
3041 };
3042 
3043 static int sci_remove(struct platform_device *dev)
3044 {
3045 	struct sci_port *port = platform_get_drvdata(dev);
3046 
3047 	sci_ports_in_use &= ~BIT(port->port.line);
3048 	uart_remove_one_port(&sci_uart_driver, &port->port);
3049 
3050 	sci_cleanup_single(port);
3051 
3052 	if (port->port.fifosize > 1) {
3053 		sysfs_remove_file(&dev->dev.kobj,
3054 				  &dev_attr_rx_fifo_trigger.attr);
3055 	}
3056 	if (port->port.type == PORT_SCIFA || port->port.type == PORT_SCIFB ||
3057 	    port->port.type == PORT_HSCIF) {
3058 		sysfs_remove_file(&dev->dev.kobj,
3059 				  &dev_attr_rx_fifo_timeout.attr);
3060 	}
3061 
3062 	return 0;
3063 }
3064 
3065 
3066 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3067 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3068 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3069 
3070 static const struct of_device_id of_sci_match[] = {
3071 	/* SoC-specific types */
3072 	{
3073 		.compatible = "renesas,scif-r7s72100",
3074 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3075 	},
3076 	/* Family-specific types */
3077 	{
3078 		.compatible = "renesas,rcar-gen1-scif",
3079 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3080 	}, {
3081 		.compatible = "renesas,rcar-gen2-scif",
3082 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3083 	}, {
3084 		.compatible = "renesas,rcar-gen3-scif",
3085 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3086 	},
3087 	/* Generic types */
3088 	{
3089 		.compatible = "renesas,scif",
3090 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3091 	}, {
3092 		.compatible = "renesas,scifa",
3093 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3094 	}, {
3095 		.compatible = "renesas,scifb",
3096 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3097 	}, {
3098 		.compatible = "renesas,hscif",
3099 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3100 	}, {
3101 		.compatible = "renesas,sci",
3102 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3103 	}, {
3104 		/* Terminator */
3105 	},
3106 };
3107 MODULE_DEVICE_TABLE(of, of_sci_match);
3108 
3109 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3110 					  unsigned int *dev_id)
3111 {
3112 	struct device_node *np = pdev->dev.of_node;
3113 	struct plat_sci_port *p;
3114 	struct sci_port *sp;
3115 	const void *data;
3116 	int id;
3117 
3118 	if (!IS_ENABLED(CONFIG_OF) || !np)
3119 		return NULL;
3120 
3121 	data = of_device_get_match_data(&pdev->dev);
3122 
3123 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3124 	if (!p)
3125 		return NULL;
3126 
3127 	/* Get the line number from the aliases node. */
3128 	id = of_alias_get_id(np, "serial");
3129 	if (id < 0 && ~sci_ports_in_use)
3130 		id = ffz(sci_ports_in_use);
3131 	if (id < 0) {
3132 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3133 		return NULL;
3134 	}
3135 	if (id >= ARRAY_SIZE(sci_ports)) {
3136 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3137 		return NULL;
3138 	}
3139 
3140 	sp = &sci_ports[id];
3141 	*dev_id = id;
3142 
3143 	p->type = SCI_OF_TYPE(data);
3144 	p->regtype = SCI_OF_REGTYPE(data);
3145 
3146 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3147 
3148 	return p;
3149 }
3150 
3151 static int sci_probe_single(struct platform_device *dev,
3152 				      unsigned int index,
3153 				      struct plat_sci_port *p,
3154 				      struct sci_port *sciport)
3155 {
3156 	int ret;
3157 
3158 	/* Sanity check */
3159 	if (unlikely(index >= SCI_NPORTS)) {
3160 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3161 			   index+1, SCI_NPORTS);
3162 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3163 		return -EINVAL;
3164 	}
3165 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3166 	if (sci_ports_in_use & BIT(index))
3167 		return -EBUSY;
3168 
3169 	mutex_lock(&sci_uart_registration_lock);
3170 	if (!sci_uart_driver.state) {
3171 		ret = uart_register_driver(&sci_uart_driver);
3172 		if (ret) {
3173 			mutex_unlock(&sci_uart_registration_lock);
3174 			return ret;
3175 		}
3176 	}
3177 	mutex_unlock(&sci_uart_registration_lock);
3178 
3179 	ret = sci_init_single(dev, sciport, index, p, false);
3180 	if (ret)
3181 		return ret;
3182 
3183 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3184 	if (IS_ERR(sciport->gpios) && PTR_ERR(sciport->gpios) != -ENOSYS)
3185 		return PTR_ERR(sciport->gpios);
3186 
3187 	if (sciport->has_rtscts) {
3188 		if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3189 							UART_GPIO_CTS)) ||
3190 		    !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3191 							UART_GPIO_RTS))) {
3192 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3193 			return -EINVAL;
3194 		}
3195 		sciport->port.flags |= UPF_HARD_FLOW;
3196 	}
3197 
3198 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3199 	if (ret) {
3200 		sci_cleanup_single(sciport);
3201 		return ret;
3202 	}
3203 
3204 	return 0;
3205 }
3206 
3207 static int sci_probe(struct platform_device *dev)
3208 {
3209 	struct plat_sci_port *p;
3210 	struct sci_port *sp;
3211 	unsigned int dev_id;
3212 	int ret;
3213 
3214 	/*
3215 	 * If we've come here via earlyprintk initialization, head off to
3216 	 * the special early probe. We don't have sufficient device state
3217 	 * to make it beyond this yet.
3218 	 */
3219 	if (is_early_platform_device(dev))
3220 		return sci_probe_earlyprintk(dev);
3221 
3222 	if (dev->dev.of_node) {
3223 		p = sci_parse_dt(dev, &dev_id);
3224 		if (p == NULL)
3225 			return -EINVAL;
3226 	} else {
3227 		p = dev->dev.platform_data;
3228 		if (p == NULL) {
3229 			dev_err(&dev->dev, "no platform data supplied\n");
3230 			return -EINVAL;
3231 		}
3232 
3233 		dev_id = dev->id;
3234 	}
3235 
3236 	sp = &sci_ports[dev_id];
3237 	platform_set_drvdata(dev, sp);
3238 
3239 	ret = sci_probe_single(dev, dev_id, p, sp);
3240 	if (ret)
3241 		return ret;
3242 
3243 	if (sp->port.fifosize > 1) {
3244 		ret = sysfs_create_file(&dev->dev.kobj,
3245 				&dev_attr_rx_fifo_trigger.attr);
3246 		if (ret)
3247 			return ret;
3248 	}
3249 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3250 	    sp->port.type == PORT_HSCIF) {
3251 		ret = sysfs_create_file(&dev->dev.kobj,
3252 				&dev_attr_rx_fifo_timeout.attr);
3253 		if (ret) {
3254 			if (sp->port.fifosize > 1) {
3255 				sysfs_remove_file(&dev->dev.kobj,
3256 					&dev_attr_rx_fifo_trigger.attr);
3257 			}
3258 			return ret;
3259 		}
3260 	}
3261 
3262 #ifdef CONFIG_SH_STANDARD_BIOS
3263 	sh_bios_gdb_detach();
3264 #endif
3265 
3266 	sci_ports_in_use |= BIT(dev_id);
3267 	return 0;
3268 }
3269 
3270 static __maybe_unused int sci_suspend(struct device *dev)
3271 {
3272 	struct sci_port *sport = dev_get_drvdata(dev);
3273 
3274 	if (sport)
3275 		uart_suspend_port(&sci_uart_driver, &sport->port);
3276 
3277 	return 0;
3278 }
3279 
3280 static __maybe_unused int sci_resume(struct device *dev)
3281 {
3282 	struct sci_port *sport = dev_get_drvdata(dev);
3283 
3284 	if (sport)
3285 		uart_resume_port(&sci_uart_driver, &sport->port);
3286 
3287 	return 0;
3288 }
3289 
3290 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3291 
3292 static struct platform_driver sci_driver = {
3293 	.probe		= sci_probe,
3294 	.remove		= sci_remove,
3295 	.driver		= {
3296 		.name	= "sh-sci",
3297 		.pm	= &sci_dev_pm_ops,
3298 		.of_match_table = of_match_ptr(of_sci_match),
3299 	},
3300 };
3301 
3302 static int __init sci_init(void)
3303 {
3304 	pr_info("%s\n", banner);
3305 
3306 	return platform_driver_register(&sci_driver);
3307 }
3308 
3309 static void __exit sci_exit(void)
3310 {
3311 	platform_driver_unregister(&sci_driver);
3312 
3313 	if (sci_uart_driver.state)
3314 		uart_unregister_driver(&sci_uart_driver);
3315 }
3316 
3317 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3318 early_platform_init_buffer("earlyprintk", &sci_driver,
3319 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3320 #endif
3321 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3322 static struct plat_sci_port port_cfg __initdata;
3323 
3324 static int __init early_console_setup(struct earlycon_device *device,
3325 				      int type)
3326 {
3327 	if (!device->port.membase)
3328 		return -ENODEV;
3329 
3330 	device->port.serial_in = sci_serial_in;
3331 	device->port.serial_out	= sci_serial_out;
3332 	device->port.type = type;
3333 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3334 	port_cfg.type = type;
3335 	sci_ports[0].cfg = &port_cfg;
3336 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3337 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3338 	sci_serial_out(&sci_ports[0].port, SCSCR,
3339 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3340 
3341 	device->con->write = serial_console_write;
3342 	return 0;
3343 }
3344 static int __init sci_early_console_setup(struct earlycon_device *device,
3345 					  const char *opt)
3346 {
3347 	return early_console_setup(device, PORT_SCI);
3348 }
3349 static int __init scif_early_console_setup(struct earlycon_device *device,
3350 					  const char *opt)
3351 {
3352 	return early_console_setup(device, PORT_SCIF);
3353 }
3354 static int __init scifa_early_console_setup(struct earlycon_device *device,
3355 					  const char *opt)
3356 {
3357 	return early_console_setup(device, PORT_SCIFA);
3358 }
3359 static int __init scifb_early_console_setup(struct earlycon_device *device,
3360 					  const char *opt)
3361 {
3362 	return early_console_setup(device, PORT_SCIFB);
3363 }
3364 static int __init hscif_early_console_setup(struct earlycon_device *device,
3365 					  const char *opt)
3366 {
3367 	return early_console_setup(device, PORT_HSCIF);
3368 }
3369 
3370 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3371 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3372 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3373 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3374 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3375 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3376 
3377 module_init(sci_init);
3378 module_exit(sci_exit);
3379 
3380 MODULE_LICENSE("GPL");
3381 MODULE_ALIAS("platform:sh-sci");
3382 MODULE_AUTHOR("Paul Mundt");
3383 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3384