xref: /linux/drivers/tty/serial/sh-sci.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
4  *
5  *  Copyright (C) 2002 - 2011  Paul Mundt
6  *  Copyright (C) 2015 Glider bvba
7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
8  *
9  * based off of the old drivers/char/sh-sci.c by:
10  *
11  *   Copyright (C) 1999, 2000  Niibe Yutaka
12  *   Copyright (C) 2000  Sugioka Toshinobu
13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
14  *   Modified to support SecureEdge. David McCullough (2002)
15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
16  *   Removed SH7300 support (Jul 2007).
17  */
18 #undef DEBUG
19 
20 #include <linux/clk.h>
21 #include <linux/console.h>
22 #include <linux/ctype.h>
23 #include <linux/cpufreq.h>
24 #include <linux/delay.h>
25 #include <linux/dmaengine.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/ioport.h>
32 #include <linux/ktime.h>
33 #include <linux/major.h>
34 #include <linux/minmax.h>
35 #include <linux/module.h>
36 #include <linux/mm.h>
37 #include <linux/of.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm_runtime.h>
40 #include <linux/reset.h>
41 #include <linux/scatterlist.h>
42 #include <linux/serial.h>
43 #include <linux/serial_sci.h>
44 #include <linux/sh_dma.h>
45 #include <linux/slab.h>
46 #include <linux/string.h>
47 #include <linux/sysrq.h>
48 #include <linux/timer.h>
49 #include <linux/tty.h>
50 #include <linux/tty_flip.h>
51 
52 #ifdef CONFIG_SUPERH
53 #include <asm/sh_bios.h>
54 #include <asm/platform_early.h>
55 #endif
56 
57 #include "serial_mctrl_gpio.h"
58 #include "sh-sci.h"
59 
60 /* Offsets into the sci_port->irqs array */
61 enum {
62 	SCIx_ERI_IRQ,
63 	SCIx_RXI_IRQ,
64 	SCIx_TXI_IRQ,
65 	SCIx_BRI_IRQ,
66 	SCIx_DRI_IRQ,
67 	SCIx_TEI_IRQ,
68 	SCIx_NR_IRQS,
69 
70 	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
71 };
72 
73 #define SCIx_IRQ_IS_MUXED(port)			\
74 	((port)->irqs[SCIx_ERI_IRQ] ==	\
75 	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
76 	((port)->irqs[SCIx_ERI_IRQ] &&	\
77 	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
78 
79 enum SCI_CLKS {
80 	SCI_FCK,		/* Functional Clock */
81 	SCI_SCK,		/* Optional External Clock */
82 	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
83 	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
84 	SCI_NUM_CLKS
85 };
86 
87 /* Bit x set means sampling rate x + 1 is supported */
88 #define SCI_SR(x)		BIT((x) - 1)
89 #define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
90 
91 #define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
92 				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
93 				SCI_SR(19) | SCI_SR(27)
94 
95 #define min_sr(_port)		ffs((_port)->sampling_rate_mask)
96 #define max_sr(_port)		fls((_port)->sampling_rate_mask)
97 
98 /* Iterate over all supported sampling rates, from high to low */
99 #define for_each_sr(_sr, _port)						\
100 	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
101 		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
102 
103 struct plat_sci_reg {
104 	u8 offset, size;
105 };
106 
107 struct sci_port_params {
108 	const struct plat_sci_reg regs[SCIx_NR_REGS];
109 	unsigned int fifosize;
110 	unsigned int overrun_reg;
111 	unsigned int overrun_mask;
112 	unsigned int sampling_rate_mask;
113 	unsigned int error_mask;
114 	unsigned int error_clear;
115 };
116 
117 struct sci_port {
118 	struct uart_port	port;
119 
120 	/* Platform configuration */
121 	const struct sci_port_params *params;
122 	const struct plat_sci_port *cfg;
123 	unsigned int		sampling_rate_mask;
124 	resource_size_t		reg_size;
125 	struct mctrl_gpios	*gpios;
126 
127 	/* Clocks */
128 	struct clk		*clks[SCI_NUM_CLKS];
129 	unsigned long		clk_rates[SCI_NUM_CLKS];
130 
131 	int			irqs[SCIx_NR_IRQS];
132 	char			*irqstr[SCIx_NR_IRQS];
133 
134 	struct dma_chan			*chan_tx;
135 	struct dma_chan			*chan_rx;
136 
137 #ifdef CONFIG_SERIAL_SH_SCI_DMA
138 	struct dma_chan			*chan_tx_saved;
139 	struct dma_chan			*chan_rx_saved;
140 	dma_cookie_t			cookie_tx;
141 	dma_cookie_t			cookie_rx[2];
142 	dma_cookie_t			active_rx;
143 	dma_addr_t			tx_dma_addr;
144 	unsigned int			tx_dma_len;
145 	struct scatterlist		sg_rx[2];
146 	void				*rx_buf[2];
147 	size_t				buf_len_rx;
148 	struct work_struct		work_tx;
149 	struct hrtimer			rx_timer;
150 	unsigned int			rx_timeout;	/* microseconds */
151 #endif
152 	unsigned int			rx_frame;
153 	int				rx_trigger;
154 	struct timer_list		rx_fifo_timer;
155 	int				rx_fifo_timeout;
156 	u16				hscif_tot;
157 
158 	bool has_rtscts;
159 	bool autorts;
160 };
161 
162 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
163 
164 static struct sci_port sci_ports[SCI_NPORTS];
165 static unsigned long sci_ports_in_use;
166 static struct uart_driver sci_uart_driver;
167 
168 static inline struct sci_port *
169 to_sci_port(struct uart_port *uart)
170 {
171 	return container_of(uart, struct sci_port, port);
172 }
173 
174 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
175 	/*
176 	 * Common SCI definitions, dependent on the port's regshift
177 	 * value.
178 	 */
179 	[SCIx_SCI_REGTYPE] = {
180 		.regs = {
181 			[SCSMR]		= { 0x00,  8 },
182 			[SCBRR]		= { 0x01,  8 },
183 			[SCSCR]		= { 0x02,  8 },
184 			[SCxTDR]	= { 0x03,  8 },
185 			[SCxSR]		= { 0x04,  8 },
186 			[SCxRDR]	= { 0x05,  8 },
187 		},
188 		.fifosize = 1,
189 		.overrun_reg = SCxSR,
190 		.overrun_mask = SCI_ORER,
191 		.sampling_rate_mask = SCI_SR(32),
192 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
193 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
194 	},
195 
196 	/*
197 	 * Common definitions for legacy IrDA ports.
198 	 */
199 	[SCIx_IRDA_REGTYPE] = {
200 		.regs = {
201 			[SCSMR]		= { 0x00,  8 },
202 			[SCBRR]		= { 0x02,  8 },
203 			[SCSCR]		= { 0x04,  8 },
204 			[SCxTDR]	= { 0x06,  8 },
205 			[SCxSR]		= { 0x08, 16 },
206 			[SCxRDR]	= { 0x0a,  8 },
207 			[SCFCR]		= { 0x0c,  8 },
208 			[SCFDR]		= { 0x0e, 16 },
209 		},
210 		.fifosize = 1,
211 		.overrun_reg = SCxSR,
212 		.overrun_mask = SCI_ORER,
213 		.sampling_rate_mask = SCI_SR(32),
214 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
215 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
216 	},
217 
218 	/*
219 	 * Common SCIFA definitions.
220 	 */
221 	[SCIx_SCIFA_REGTYPE] = {
222 		.regs = {
223 			[SCSMR]		= { 0x00, 16 },
224 			[SCBRR]		= { 0x04,  8 },
225 			[SCSCR]		= { 0x08, 16 },
226 			[SCxTDR]	= { 0x20,  8 },
227 			[SCxSR]		= { 0x14, 16 },
228 			[SCxRDR]	= { 0x24,  8 },
229 			[SCFCR]		= { 0x18, 16 },
230 			[SCFDR]		= { 0x1c, 16 },
231 			[SCPCR]		= { 0x30, 16 },
232 			[SCPDR]		= { 0x34, 16 },
233 		},
234 		.fifosize = 64,
235 		.overrun_reg = SCxSR,
236 		.overrun_mask = SCIFA_ORER,
237 		.sampling_rate_mask = SCI_SR_SCIFAB,
238 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
239 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
240 	},
241 
242 	/*
243 	 * Common SCIFB definitions.
244 	 */
245 	[SCIx_SCIFB_REGTYPE] = {
246 		.regs = {
247 			[SCSMR]		= { 0x00, 16 },
248 			[SCBRR]		= { 0x04,  8 },
249 			[SCSCR]		= { 0x08, 16 },
250 			[SCxTDR]	= { 0x40,  8 },
251 			[SCxSR]		= { 0x14, 16 },
252 			[SCxRDR]	= { 0x60,  8 },
253 			[SCFCR]		= { 0x18, 16 },
254 			[SCTFDR]	= { 0x38, 16 },
255 			[SCRFDR]	= { 0x3c, 16 },
256 			[SCPCR]		= { 0x30, 16 },
257 			[SCPDR]		= { 0x34, 16 },
258 		},
259 		.fifosize = 256,
260 		.overrun_reg = SCxSR,
261 		.overrun_mask = SCIFA_ORER,
262 		.sampling_rate_mask = SCI_SR_SCIFAB,
263 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
264 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
265 	},
266 
267 	/*
268 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
269 	 * count registers.
270 	 */
271 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
272 		.regs = {
273 			[SCSMR]		= { 0x00, 16 },
274 			[SCBRR]		= { 0x04,  8 },
275 			[SCSCR]		= { 0x08, 16 },
276 			[SCxTDR]	= { 0x0c,  8 },
277 			[SCxSR]		= { 0x10, 16 },
278 			[SCxRDR]	= { 0x14,  8 },
279 			[SCFCR]		= { 0x18, 16 },
280 			[SCFDR]		= { 0x1c, 16 },
281 			[SCSPTR]	= { 0x20, 16 },
282 			[SCLSR]		= { 0x24, 16 },
283 		},
284 		.fifosize = 16,
285 		.overrun_reg = SCLSR,
286 		.overrun_mask = SCLSR_ORER,
287 		.sampling_rate_mask = SCI_SR(32),
288 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
289 		.error_clear = SCIF_ERROR_CLEAR,
290 	},
291 
292 	/*
293 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
294 	 * It looks like a normal SCIF with FIFO data, but with a
295 	 * compressed address space. Also, the break out of interrupts
296 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
297 	 */
298 	[SCIx_RZ_SCIFA_REGTYPE] = {
299 		.regs = {
300 			[SCSMR]		= { 0x00, 16 },
301 			[SCBRR]		= { 0x02,  8 },
302 			[SCSCR]		= { 0x04, 16 },
303 			[SCxTDR]	= { 0x06,  8 },
304 			[SCxSR]		= { 0x08, 16 },
305 			[SCxRDR]	= { 0x0A,  8 },
306 			[SCFCR]		= { 0x0C, 16 },
307 			[SCFDR]		= { 0x0E, 16 },
308 			[SCSPTR]	= { 0x10, 16 },
309 			[SCLSR]		= { 0x12, 16 },
310 			[SEMR]		= { 0x14, 8 },
311 		},
312 		.fifosize = 16,
313 		.overrun_reg = SCLSR,
314 		.overrun_mask = SCLSR_ORER,
315 		.sampling_rate_mask = SCI_SR(32),
316 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
317 		.error_clear = SCIF_ERROR_CLEAR,
318 	},
319 
320 	/*
321 	 * The "SCIF" that is in RZ/V2H(P) SoC is similar to one found on RZ/G2L SoC
322 	 * with below differences,
323 	 * - Break out of interrupts are different: ERI, BRI, RXI, TXI, TEI, DRI,
324 	 *   TEI-DRI, RXI-EDGE and TXI-EDGE.
325 	 * - SCSMR register does not have CM bit (BIT(7)) ie it does not support synchronous mode.
326 	 * - SCFCR register does not have SCFCR_MCE bit.
327 	 * - SCSPTR register has only bits SCSPTR_SPB2DT and SCSPTR_SPB2IO.
328 	 */
329 	[SCIx_RZV2H_SCIF_REGTYPE] = {
330 		.regs = {
331 			[SCSMR]		= { 0x00, 16 },
332 			[SCBRR]		= { 0x02,  8 },
333 			[SCSCR]		= { 0x04, 16 },
334 			[SCxTDR]	= { 0x06,  8 },
335 			[SCxSR]		= { 0x08, 16 },
336 			[SCxRDR]	= { 0x0a,  8 },
337 			[SCFCR]		= { 0x0c, 16 },
338 			[SCFDR]		= { 0x0e, 16 },
339 			[SCSPTR]	= { 0x10, 16 },
340 			[SCLSR]		= { 0x12, 16 },
341 			[SEMR]		= { 0x14, 8 },
342 		},
343 		.fifosize = 16,
344 		.overrun_reg = SCLSR,
345 		.overrun_mask = SCLSR_ORER,
346 		.sampling_rate_mask = SCI_SR(32),
347 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
348 		.error_clear = SCIF_ERROR_CLEAR,
349 	},
350 
351 	/*
352 	 * Common SH-3 SCIF definitions.
353 	 */
354 	[SCIx_SH3_SCIF_REGTYPE] = {
355 		.regs = {
356 			[SCSMR]		= { 0x00,  8 },
357 			[SCBRR]		= { 0x02,  8 },
358 			[SCSCR]		= { 0x04,  8 },
359 			[SCxTDR]	= { 0x06,  8 },
360 			[SCxSR]		= { 0x08, 16 },
361 			[SCxRDR]	= { 0x0a,  8 },
362 			[SCFCR]		= { 0x0c,  8 },
363 			[SCFDR]		= { 0x0e, 16 },
364 		},
365 		.fifosize = 16,
366 		.overrun_reg = SCLSR,
367 		.overrun_mask = SCLSR_ORER,
368 		.sampling_rate_mask = SCI_SR(32),
369 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
370 		.error_clear = SCIF_ERROR_CLEAR,
371 	},
372 
373 	/*
374 	 * Common SH-4(A) SCIF(B) definitions.
375 	 */
376 	[SCIx_SH4_SCIF_REGTYPE] = {
377 		.regs = {
378 			[SCSMR]		= { 0x00, 16 },
379 			[SCBRR]		= { 0x04,  8 },
380 			[SCSCR]		= { 0x08, 16 },
381 			[SCxTDR]	= { 0x0c,  8 },
382 			[SCxSR]		= { 0x10, 16 },
383 			[SCxRDR]	= { 0x14,  8 },
384 			[SCFCR]		= { 0x18, 16 },
385 			[SCFDR]		= { 0x1c, 16 },
386 			[SCSPTR]	= { 0x20, 16 },
387 			[SCLSR]		= { 0x24, 16 },
388 		},
389 		.fifosize = 16,
390 		.overrun_reg = SCLSR,
391 		.overrun_mask = SCLSR_ORER,
392 		.sampling_rate_mask = SCI_SR(32),
393 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
394 		.error_clear = SCIF_ERROR_CLEAR,
395 	},
396 
397 	/*
398 	 * Common SCIF definitions for ports with a Baud Rate Generator for
399 	 * External Clock (BRG).
400 	 */
401 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
402 		.regs = {
403 			[SCSMR]		= { 0x00, 16 },
404 			[SCBRR]		= { 0x04,  8 },
405 			[SCSCR]		= { 0x08, 16 },
406 			[SCxTDR]	= { 0x0c,  8 },
407 			[SCxSR]		= { 0x10, 16 },
408 			[SCxRDR]	= { 0x14,  8 },
409 			[SCFCR]		= { 0x18, 16 },
410 			[SCFDR]		= { 0x1c, 16 },
411 			[SCSPTR]	= { 0x20, 16 },
412 			[SCLSR]		= { 0x24, 16 },
413 			[SCDL]		= { 0x30, 16 },
414 			[SCCKS]		= { 0x34, 16 },
415 		},
416 		.fifosize = 16,
417 		.overrun_reg = SCLSR,
418 		.overrun_mask = SCLSR_ORER,
419 		.sampling_rate_mask = SCI_SR(32),
420 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
421 		.error_clear = SCIF_ERROR_CLEAR,
422 	},
423 
424 	/*
425 	 * Common HSCIF definitions.
426 	 */
427 	[SCIx_HSCIF_REGTYPE] = {
428 		.regs = {
429 			[SCSMR]		= { 0x00, 16 },
430 			[SCBRR]		= { 0x04,  8 },
431 			[SCSCR]		= { 0x08, 16 },
432 			[SCxTDR]	= { 0x0c,  8 },
433 			[SCxSR]		= { 0x10, 16 },
434 			[SCxRDR]	= { 0x14,  8 },
435 			[SCFCR]		= { 0x18, 16 },
436 			[SCFDR]		= { 0x1c, 16 },
437 			[SCSPTR]	= { 0x20, 16 },
438 			[SCLSR]		= { 0x24, 16 },
439 			[HSSRR]		= { 0x40, 16 },
440 			[SCDL]		= { 0x30, 16 },
441 			[SCCKS]		= { 0x34, 16 },
442 			[HSRTRGR]	= { 0x54, 16 },
443 			[HSTTRGR]	= { 0x58, 16 },
444 		},
445 		.fifosize = 128,
446 		.overrun_reg = SCLSR,
447 		.overrun_mask = SCLSR_ORER,
448 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
449 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
450 		.error_clear = SCIF_ERROR_CLEAR,
451 	},
452 
453 	/*
454 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
455 	 * register.
456 	 */
457 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
458 		.regs = {
459 			[SCSMR]		= { 0x00, 16 },
460 			[SCBRR]		= { 0x04,  8 },
461 			[SCSCR]		= { 0x08, 16 },
462 			[SCxTDR]	= { 0x0c,  8 },
463 			[SCxSR]		= { 0x10, 16 },
464 			[SCxRDR]	= { 0x14,  8 },
465 			[SCFCR]		= { 0x18, 16 },
466 			[SCFDR]		= { 0x1c, 16 },
467 			[SCLSR]		= { 0x24, 16 },
468 		},
469 		.fifosize = 16,
470 		.overrun_reg = SCLSR,
471 		.overrun_mask = SCLSR_ORER,
472 		.sampling_rate_mask = SCI_SR(32),
473 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
474 		.error_clear = SCIF_ERROR_CLEAR,
475 	},
476 
477 	/*
478 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
479 	 * count registers.
480 	 */
481 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
482 		.regs = {
483 			[SCSMR]		= { 0x00, 16 },
484 			[SCBRR]		= { 0x04,  8 },
485 			[SCSCR]		= { 0x08, 16 },
486 			[SCxTDR]	= { 0x0c,  8 },
487 			[SCxSR]		= { 0x10, 16 },
488 			[SCxRDR]	= { 0x14,  8 },
489 			[SCFCR]		= { 0x18, 16 },
490 			[SCFDR]		= { 0x1c, 16 },
491 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
492 			[SCRFDR]	= { 0x20, 16 },
493 			[SCSPTR]	= { 0x24, 16 },
494 			[SCLSR]		= { 0x28, 16 },
495 		},
496 		.fifosize = 16,
497 		.overrun_reg = SCLSR,
498 		.overrun_mask = SCLSR_ORER,
499 		.sampling_rate_mask = SCI_SR(32),
500 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
501 		.error_clear = SCIF_ERROR_CLEAR,
502 	},
503 
504 	/*
505 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
506 	 * registers.
507 	 */
508 	[SCIx_SH7705_SCIF_REGTYPE] = {
509 		.regs = {
510 			[SCSMR]		= { 0x00, 16 },
511 			[SCBRR]		= { 0x04,  8 },
512 			[SCSCR]		= { 0x08, 16 },
513 			[SCxTDR]	= { 0x20,  8 },
514 			[SCxSR]		= { 0x14, 16 },
515 			[SCxRDR]	= { 0x24,  8 },
516 			[SCFCR]		= { 0x18, 16 },
517 			[SCFDR]		= { 0x1c, 16 },
518 		},
519 		.fifosize = 64,
520 		.overrun_reg = SCxSR,
521 		.overrun_mask = SCIFA_ORER,
522 		.sampling_rate_mask = SCI_SR(16),
523 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
524 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
525 	},
526 };
527 
528 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
529 
530 /*
531  * The "offset" here is rather misleading, in that it refers to an enum
532  * value relative to the port mapping rather than the fixed offset
533  * itself, which needs to be manually retrieved from the platform's
534  * register map for the given port.
535  */
536 static unsigned int sci_serial_in(struct uart_port *p, int offset)
537 {
538 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
539 
540 	if (reg->size == 8)
541 		return ioread8(p->membase + (reg->offset << p->regshift));
542 	else if (reg->size == 16)
543 		return ioread16(p->membase + (reg->offset << p->regshift));
544 	else
545 		WARN(1, "Invalid register access\n");
546 
547 	return 0;
548 }
549 
550 static void sci_serial_out(struct uart_port *p, int offset, int value)
551 {
552 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
553 
554 	if (reg->size == 8)
555 		iowrite8(value, p->membase + (reg->offset << p->regshift));
556 	else if (reg->size == 16)
557 		iowrite16(value, p->membase + (reg->offset << p->regshift));
558 	else
559 		WARN(1, "Invalid register access\n");
560 }
561 
562 static void sci_port_enable(struct sci_port *sci_port)
563 {
564 	unsigned int i;
565 
566 	if (!sci_port->port.dev)
567 		return;
568 
569 	pm_runtime_get_sync(sci_port->port.dev);
570 
571 	for (i = 0; i < SCI_NUM_CLKS; i++) {
572 		clk_prepare_enable(sci_port->clks[i]);
573 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
574 	}
575 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
576 }
577 
578 static void sci_port_disable(struct sci_port *sci_port)
579 {
580 	unsigned int i;
581 
582 	if (!sci_port->port.dev)
583 		return;
584 
585 	for (i = SCI_NUM_CLKS; i-- > 0; )
586 		clk_disable_unprepare(sci_port->clks[i]);
587 
588 	pm_runtime_put_sync(sci_port->port.dev);
589 }
590 
591 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
592 {
593 	/*
594 	 * Not all ports (such as SCIFA) will support REIE. Rather than
595 	 * special-casing the port type, we check the port initialization
596 	 * IRQ enable mask to see whether the IRQ is desired at all. If
597 	 * it's unset, it's logically inferred that there's no point in
598 	 * testing for it.
599 	 */
600 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
601 }
602 
603 static void sci_start_tx(struct uart_port *port)
604 {
605 	struct sci_port *s = to_sci_port(port);
606 	unsigned short ctrl;
607 
608 #ifdef CONFIG_SERIAL_SH_SCI_DMA
609 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
610 		u16 new, scr = sci_serial_in(port, SCSCR);
611 		if (s->chan_tx)
612 			new = scr | SCSCR_TDRQE;
613 		else
614 			new = scr & ~SCSCR_TDRQE;
615 		if (new != scr)
616 			sci_serial_out(port, SCSCR, new);
617 	}
618 
619 	if (s->chan_tx && !kfifo_is_empty(&port->state->port.xmit_fifo) &&
620 	    dma_submit_error(s->cookie_tx)) {
621 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
622 			/* Switch irq from SCIF to DMA */
623 			disable_irq_nosync(s->irqs[SCIx_TXI_IRQ]);
624 
625 		s->cookie_tx = 0;
626 		schedule_work(&s->work_tx);
627 	}
628 #endif
629 
630 	if (!s->chan_tx || s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE ||
631 	    port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
632 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
633 		ctrl = sci_serial_in(port, SCSCR);
634 
635 		/*
636 		 * For SCI, TE (transmit enable) must be set after setting TIE
637 		 * (transmit interrupt enable) or in the same instruction to start
638 		 * the transmit process.
639 		 */
640 		if (port->type == PORT_SCI)
641 			ctrl |= SCSCR_TE;
642 
643 		sci_serial_out(port, SCSCR, ctrl | SCSCR_TIE);
644 	}
645 }
646 
647 static void sci_stop_tx(struct uart_port *port)
648 {
649 	unsigned short ctrl;
650 
651 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
652 	ctrl = sci_serial_in(port, SCSCR);
653 
654 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
655 		ctrl &= ~SCSCR_TDRQE;
656 
657 	ctrl &= ~SCSCR_TIE;
658 
659 	sci_serial_out(port, SCSCR, ctrl);
660 
661 #ifdef CONFIG_SERIAL_SH_SCI_DMA
662 	if (to_sci_port(port)->chan_tx &&
663 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
664 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
665 		to_sci_port(port)->cookie_tx = -EINVAL;
666 	}
667 #endif
668 }
669 
670 static void sci_start_rx(struct uart_port *port)
671 {
672 	unsigned short ctrl;
673 
674 	ctrl = sci_serial_in(port, SCSCR) | port_rx_irq_mask(port);
675 
676 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
677 		ctrl &= ~SCSCR_RDRQE;
678 
679 	sci_serial_out(port, SCSCR, ctrl);
680 }
681 
682 static void sci_stop_rx(struct uart_port *port)
683 {
684 	unsigned short ctrl;
685 
686 	ctrl = sci_serial_in(port, SCSCR);
687 
688 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
689 		ctrl &= ~SCSCR_RDRQE;
690 
691 	ctrl &= ~port_rx_irq_mask(port);
692 
693 	sci_serial_out(port, SCSCR, ctrl);
694 }
695 
696 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
697 {
698 	if (port->type == PORT_SCI) {
699 		/* Just store the mask */
700 		sci_serial_out(port, SCxSR, mask);
701 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
702 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
703 		/* Only clear the status bits we want to clear */
704 		sci_serial_out(port, SCxSR, sci_serial_in(port, SCxSR) & mask);
705 	} else {
706 		/* Store the mask, clear parity/framing errors */
707 		sci_serial_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
708 	}
709 }
710 
711 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
712     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
713 
714 #ifdef CONFIG_CONSOLE_POLL
715 static int sci_poll_get_char(struct uart_port *port)
716 {
717 	unsigned short status;
718 	int c;
719 
720 	do {
721 		status = sci_serial_in(port, SCxSR);
722 		if (status & SCxSR_ERRORS(port)) {
723 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
724 			continue;
725 		}
726 		break;
727 	} while (1);
728 
729 	if (!(status & SCxSR_RDxF(port)))
730 		return NO_POLL_CHAR;
731 
732 	c = sci_serial_in(port, SCxRDR);
733 
734 	/* Dummy read */
735 	sci_serial_in(port, SCxSR);
736 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
737 
738 	return c;
739 }
740 #endif
741 
742 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
743 {
744 	unsigned short status;
745 
746 	do {
747 		status = sci_serial_in(port, SCxSR);
748 	} while (!(status & SCxSR_TDxE(port)));
749 
750 	sci_serial_out(port, SCxTDR, c);
751 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
752 }
753 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
754 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
755 
756 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
757 {
758 	struct sci_port *s = to_sci_port(port);
759 
760 	/*
761 	 * Use port-specific handler if provided.
762 	 */
763 	if (s->cfg->ops && s->cfg->ops->init_pins) {
764 		s->cfg->ops->init_pins(port, cflag);
765 		return;
766 	}
767 
768 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
769 		u16 data = sci_serial_in(port, SCPDR);
770 		u16 ctrl = sci_serial_in(port, SCPCR);
771 
772 		/* Enable RXD and TXD pin functions */
773 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
774 		if (to_sci_port(port)->has_rtscts) {
775 			/* RTS# is output, active low, unless autorts */
776 			if (!(port->mctrl & TIOCM_RTS)) {
777 				ctrl |= SCPCR_RTSC;
778 				data |= SCPDR_RTSD;
779 			} else if (!s->autorts) {
780 				ctrl |= SCPCR_RTSC;
781 				data &= ~SCPDR_RTSD;
782 			} else {
783 				/* Enable RTS# pin function */
784 				ctrl &= ~SCPCR_RTSC;
785 			}
786 			/* Enable CTS# pin function */
787 			ctrl &= ~SCPCR_CTSC;
788 		}
789 		sci_serial_out(port, SCPDR, data);
790 		sci_serial_out(port, SCPCR, ctrl);
791 	} else if (sci_getreg(port, SCSPTR)->size && s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE) {
792 		u16 status = sci_serial_in(port, SCSPTR);
793 
794 		/* RTS# is always output; and active low, unless autorts */
795 		status |= SCSPTR_RTSIO;
796 		if (!(port->mctrl & TIOCM_RTS))
797 			status |= SCSPTR_RTSDT;
798 		else if (!s->autorts)
799 			status &= ~SCSPTR_RTSDT;
800 		/* CTS# and SCK are inputs */
801 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
802 		sci_serial_out(port, SCSPTR, status);
803 	}
804 }
805 
806 static int sci_txfill(struct uart_port *port)
807 {
808 	struct sci_port *s = to_sci_port(port);
809 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
810 	const struct plat_sci_reg *reg;
811 
812 	reg = sci_getreg(port, SCTFDR);
813 	if (reg->size)
814 		return sci_serial_in(port, SCTFDR) & fifo_mask;
815 
816 	reg = sci_getreg(port, SCFDR);
817 	if (reg->size)
818 		return sci_serial_in(port, SCFDR) >> 8;
819 
820 	return !(sci_serial_in(port, SCxSR) & SCI_TDRE);
821 }
822 
823 static int sci_txroom(struct uart_port *port)
824 {
825 	return port->fifosize - sci_txfill(port);
826 }
827 
828 static int sci_rxfill(struct uart_port *port)
829 {
830 	struct sci_port *s = to_sci_port(port);
831 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
832 	const struct plat_sci_reg *reg;
833 
834 	reg = sci_getreg(port, SCRFDR);
835 	if (reg->size)
836 		return sci_serial_in(port, SCRFDR) & fifo_mask;
837 
838 	reg = sci_getreg(port, SCFDR);
839 	if (reg->size)
840 		return sci_serial_in(port, SCFDR) & fifo_mask;
841 
842 	return (sci_serial_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
843 }
844 
845 /* ********************************************************************** *
846  *                   the interrupt related routines                       *
847  * ********************************************************************** */
848 
849 static void sci_transmit_chars(struct uart_port *port)
850 {
851 	struct tty_port *tport = &port->state->port;
852 	unsigned int stopped = uart_tx_stopped(port);
853 	unsigned short status;
854 	unsigned short ctrl;
855 	int count;
856 
857 	status = sci_serial_in(port, SCxSR);
858 	if (!(status & SCxSR_TDxE(port))) {
859 		ctrl = sci_serial_in(port, SCSCR);
860 		if (kfifo_is_empty(&tport->xmit_fifo))
861 			ctrl &= ~SCSCR_TIE;
862 		else
863 			ctrl |= SCSCR_TIE;
864 		sci_serial_out(port, SCSCR, ctrl);
865 		return;
866 	}
867 
868 	count = sci_txroom(port);
869 
870 	do {
871 		unsigned char c;
872 
873 		if (port->x_char) {
874 			c = port->x_char;
875 			port->x_char = 0;
876 		} else if (stopped || !kfifo_get(&tport->xmit_fifo, &c)) {
877 			if (port->type == PORT_SCI &&
878 				   kfifo_is_empty(&tport->xmit_fifo)) {
879 				ctrl = sci_serial_in(port, SCSCR);
880 				ctrl &= ~SCSCR_TE;
881 				sci_serial_out(port, SCSCR, ctrl);
882 				return;
883 			}
884 			break;
885 		}
886 
887 		sci_serial_out(port, SCxTDR, c);
888 
889 		port->icount.tx++;
890 	} while (--count > 0);
891 
892 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
893 
894 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
895 		uart_write_wakeup(port);
896 	if (kfifo_is_empty(&tport->xmit_fifo)) {
897 		if (port->type == PORT_SCI) {
898 			ctrl = sci_serial_in(port, SCSCR);
899 			ctrl &= ~SCSCR_TIE;
900 			ctrl |= SCSCR_TEIE;
901 			sci_serial_out(port, SCSCR, ctrl);
902 		}
903 
904 		sci_stop_tx(port);
905 	}
906 }
907 
908 static void sci_receive_chars(struct uart_port *port)
909 {
910 	struct tty_port *tport = &port->state->port;
911 	int i, count, copied = 0;
912 	unsigned short status;
913 	unsigned char flag;
914 
915 	status = sci_serial_in(port, SCxSR);
916 	if (!(status & SCxSR_RDxF(port)))
917 		return;
918 
919 	while (1) {
920 		/* Don't copy more bytes than there is room for in the buffer */
921 		count = tty_buffer_request_room(tport, sci_rxfill(port));
922 
923 		/* If for any reason we can't copy more data, we're done! */
924 		if (count == 0)
925 			break;
926 
927 		if (port->type == PORT_SCI) {
928 			char c = sci_serial_in(port, SCxRDR);
929 			if (uart_handle_sysrq_char(port, c))
930 				count = 0;
931 			else
932 				tty_insert_flip_char(tport, c, TTY_NORMAL);
933 		} else {
934 			for (i = 0; i < count; i++) {
935 				char c;
936 
937 				if (port->type == PORT_SCIF ||
938 				    port->type == PORT_HSCIF) {
939 					status = sci_serial_in(port, SCxSR);
940 					c = sci_serial_in(port, SCxRDR);
941 				} else {
942 					c = sci_serial_in(port, SCxRDR);
943 					status = sci_serial_in(port, SCxSR);
944 				}
945 				if (uart_handle_sysrq_char(port, c)) {
946 					count--; i--;
947 					continue;
948 				}
949 
950 				/* Store data and status */
951 				if (status & SCxSR_FER(port)) {
952 					flag = TTY_FRAME;
953 					port->icount.frame++;
954 				} else if (status & SCxSR_PER(port)) {
955 					flag = TTY_PARITY;
956 					port->icount.parity++;
957 				} else
958 					flag = TTY_NORMAL;
959 
960 				tty_insert_flip_char(tport, c, flag);
961 			}
962 		}
963 
964 		sci_serial_in(port, SCxSR); /* dummy read */
965 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
966 
967 		copied += count;
968 		port->icount.rx += count;
969 	}
970 
971 	if (copied) {
972 		/* Tell the rest of the system the news. New characters! */
973 		tty_flip_buffer_push(tport);
974 	} else {
975 		/* TTY buffers full; read from RX reg to prevent lockup */
976 		sci_serial_in(port, SCxRDR);
977 		sci_serial_in(port, SCxSR); /* dummy read */
978 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
979 	}
980 }
981 
982 static int sci_handle_errors(struct uart_port *port)
983 {
984 	int copied = 0;
985 	unsigned short status = sci_serial_in(port, SCxSR);
986 	struct tty_port *tport = &port->state->port;
987 	struct sci_port *s = to_sci_port(port);
988 
989 	/* Handle overruns */
990 	if (status & s->params->overrun_mask) {
991 		port->icount.overrun++;
992 
993 		/* overrun error */
994 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
995 			copied++;
996 	}
997 
998 	if (status & SCxSR_FER(port)) {
999 		/* frame error */
1000 		port->icount.frame++;
1001 
1002 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
1003 			copied++;
1004 	}
1005 
1006 	if (status & SCxSR_PER(port)) {
1007 		/* parity error */
1008 		port->icount.parity++;
1009 
1010 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
1011 			copied++;
1012 	}
1013 
1014 	if (copied)
1015 		tty_flip_buffer_push(tport);
1016 
1017 	return copied;
1018 }
1019 
1020 static int sci_handle_fifo_overrun(struct uart_port *port)
1021 {
1022 	struct tty_port *tport = &port->state->port;
1023 	struct sci_port *s = to_sci_port(port);
1024 	const struct plat_sci_reg *reg;
1025 	int copied = 0;
1026 	u16 status;
1027 
1028 	reg = sci_getreg(port, s->params->overrun_reg);
1029 	if (!reg->size)
1030 		return 0;
1031 
1032 	status = sci_serial_in(port, s->params->overrun_reg);
1033 	if (status & s->params->overrun_mask) {
1034 		status &= ~s->params->overrun_mask;
1035 		sci_serial_out(port, s->params->overrun_reg, status);
1036 
1037 		port->icount.overrun++;
1038 
1039 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1040 		tty_flip_buffer_push(tport);
1041 		copied++;
1042 	}
1043 
1044 	return copied;
1045 }
1046 
1047 static int sci_handle_breaks(struct uart_port *port)
1048 {
1049 	int copied = 0;
1050 	unsigned short status = sci_serial_in(port, SCxSR);
1051 	struct tty_port *tport = &port->state->port;
1052 
1053 	if (uart_handle_break(port))
1054 		return 0;
1055 
1056 	if (status & SCxSR_BRK(port)) {
1057 		port->icount.brk++;
1058 
1059 		/* Notify of BREAK */
1060 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1061 			copied++;
1062 	}
1063 
1064 	if (copied)
1065 		tty_flip_buffer_push(tport);
1066 
1067 	copied += sci_handle_fifo_overrun(port);
1068 
1069 	return copied;
1070 }
1071 
1072 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1073 {
1074 	unsigned int bits;
1075 
1076 	if (rx_trig >= port->fifosize)
1077 		rx_trig = port->fifosize - 1;
1078 	if (rx_trig < 1)
1079 		rx_trig = 1;
1080 
1081 	/* HSCIF can be set to an arbitrary level. */
1082 	if (sci_getreg(port, HSRTRGR)->size) {
1083 		sci_serial_out(port, HSRTRGR, rx_trig);
1084 		return rx_trig;
1085 	}
1086 
1087 	switch (port->type) {
1088 	case PORT_SCIF:
1089 		if (rx_trig < 4) {
1090 			bits = 0;
1091 			rx_trig = 1;
1092 		} else if (rx_trig < 8) {
1093 			bits = SCFCR_RTRG0;
1094 			rx_trig = 4;
1095 		} else if (rx_trig < 14) {
1096 			bits = SCFCR_RTRG1;
1097 			rx_trig = 8;
1098 		} else {
1099 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1100 			rx_trig = 14;
1101 		}
1102 		break;
1103 	case PORT_SCIFA:
1104 	case PORT_SCIFB:
1105 		if (rx_trig < 16) {
1106 			bits = 0;
1107 			rx_trig = 1;
1108 		} else if (rx_trig < 32) {
1109 			bits = SCFCR_RTRG0;
1110 			rx_trig = 16;
1111 		} else if (rx_trig < 48) {
1112 			bits = SCFCR_RTRG1;
1113 			rx_trig = 32;
1114 		} else {
1115 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1116 			rx_trig = 48;
1117 		}
1118 		break;
1119 	default:
1120 		WARN(1, "unknown FIFO configuration");
1121 		return 1;
1122 	}
1123 
1124 	sci_serial_out(port, SCFCR,
1125 		       (sci_serial_in(port, SCFCR) &
1126 			~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1127 
1128 	return rx_trig;
1129 }
1130 
1131 static int scif_rtrg_enabled(struct uart_port *port)
1132 {
1133 	if (sci_getreg(port, HSRTRGR)->size)
1134 		return sci_serial_in(port, HSRTRGR) != 0;
1135 	else
1136 		return (sci_serial_in(port, SCFCR) &
1137 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1138 }
1139 
1140 static void rx_fifo_timer_fn(struct timer_list *t)
1141 {
1142 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1143 	struct uart_port *port = &s->port;
1144 
1145 	dev_dbg(port->dev, "Rx timed out\n");
1146 	scif_set_rtrg(port, 1);
1147 }
1148 
1149 static ssize_t rx_fifo_trigger_show(struct device *dev,
1150 				    struct device_attribute *attr, char *buf)
1151 {
1152 	struct uart_port *port = dev_get_drvdata(dev);
1153 	struct sci_port *sci = to_sci_port(port);
1154 
1155 	return sprintf(buf, "%d\n", sci->rx_trigger);
1156 }
1157 
1158 static ssize_t rx_fifo_trigger_store(struct device *dev,
1159 				     struct device_attribute *attr,
1160 				     const char *buf, size_t count)
1161 {
1162 	struct uart_port *port = dev_get_drvdata(dev);
1163 	struct sci_port *sci = to_sci_port(port);
1164 	int ret;
1165 	long r;
1166 
1167 	ret = kstrtol(buf, 0, &r);
1168 	if (ret)
1169 		return ret;
1170 
1171 	sci->rx_trigger = scif_set_rtrg(port, r);
1172 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1173 		scif_set_rtrg(port, 1);
1174 
1175 	return count;
1176 }
1177 
1178 static DEVICE_ATTR_RW(rx_fifo_trigger);
1179 
1180 static ssize_t rx_fifo_timeout_show(struct device *dev,
1181 			       struct device_attribute *attr,
1182 			       char *buf)
1183 {
1184 	struct uart_port *port = dev_get_drvdata(dev);
1185 	struct sci_port *sci = to_sci_port(port);
1186 	int v;
1187 
1188 	if (port->type == PORT_HSCIF)
1189 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1190 	else
1191 		v = sci->rx_fifo_timeout;
1192 
1193 	return sprintf(buf, "%d\n", v);
1194 }
1195 
1196 static ssize_t rx_fifo_timeout_store(struct device *dev,
1197 				struct device_attribute *attr,
1198 				const char *buf,
1199 				size_t count)
1200 {
1201 	struct uart_port *port = dev_get_drvdata(dev);
1202 	struct sci_port *sci = to_sci_port(port);
1203 	int ret;
1204 	long r;
1205 
1206 	ret = kstrtol(buf, 0, &r);
1207 	if (ret)
1208 		return ret;
1209 
1210 	if (port->type == PORT_HSCIF) {
1211 		if (r < 0 || r > 3)
1212 			return -EINVAL;
1213 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1214 	} else {
1215 		sci->rx_fifo_timeout = r;
1216 		scif_set_rtrg(port, 1);
1217 		if (r > 0)
1218 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1219 	}
1220 
1221 	return count;
1222 }
1223 
1224 static DEVICE_ATTR_RW(rx_fifo_timeout);
1225 
1226 
1227 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1228 static void sci_dma_tx_complete(void *arg)
1229 {
1230 	struct sci_port *s = arg;
1231 	struct uart_port *port = &s->port;
1232 	struct tty_port *tport = &port->state->port;
1233 	unsigned long flags;
1234 
1235 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1236 
1237 	uart_port_lock_irqsave(port, &flags);
1238 
1239 	uart_xmit_advance(port, s->tx_dma_len);
1240 
1241 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
1242 		uart_write_wakeup(port);
1243 
1244 	if (!kfifo_is_empty(&tport->xmit_fifo)) {
1245 		s->cookie_tx = 0;
1246 		schedule_work(&s->work_tx);
1247 	} else {
1248 		s->cookie_tx = -EINVAL;
1249 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1250 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1251 			u16 ctrl = sci_serial_in(port, SCSCR);
1252 			sci_serial_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1253 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1254 				/* Switch irq from DMA to SCIF */
1255 				dmaengine_pause(s->chan_tx_saved);
1256 				enable_irq(s->irqs[SCIx_TXI_IRQ]);
1257 			}
1258 		}
1259 	}
1260 
1261 	uart_port_unlock_irqrestore(port, flags);
1262 }
1263 
1264 /* Locking: called with port lock held */
1265 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1266 {
1267 	struct uart_port *port = &s->port;
1268 	struct tty_port *tport = &port->state->port;
1269 	int copied;
1270 
1271 	copied = tty_insert_flip_string(tport, buf, count);
1272 	if (copied < count)
1273 		port->icount.buf_overrun++;
1274 
1275 	port->icount.rx += copied;
1276 
1277 	return copied;
1278 }
1279 
1280 static int sci_dma_rx_find_active(struct sci_port *s)
1281 {
1282 	unsigned int i;
1283 
1284 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1285 		if (s->active_rx == s->cookie_rx[i])
1286 			return i;
1287 
1288 	return -1;
1289 }
1290 
1291 /* Must only be called with uart_port_lock taken */
1292 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1293 {
1294 	unsigned int i;
1295 
1296 	s->chan_rx = NULL;
1297 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1298 		s->cookie_rx[i] = -EINVAL;
1299 	s->active_rx = 0;
1300 }
1301 
1302 static void sci_dma_rx_release(struct sci_port *s)
1303 {
1304 	struct dma_chan *chan = s->chan_rx_saved;
1305 	struct uart_port *port = &s->port;
1306 	unsigned long flags;
1307 
1308 	uart_port_lock_irqsave(port, &flags);
1309 	s->chan_rx_saved = NULL;
1310 	sci_dma_rx_chan_invalidate(s);
1311 	uart_port_unlock_irqrestore(port, flags);
1312 
1313 	dmaengine_terminate_sync(chan);
1314 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1315 			  sg_dma_address(&s->sg_rx[0]));
1316 	dma_release_channel(chan);
1317 }
1318 
1319 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1320 {
1321 	long sec = usec / 1000000;
1322 	long nsec = (usec % 1000000) * 1000;
1323 	ktime_t t = ktime_set(sec, nsec);
1324 
1325 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1326 }
1327 
1328 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1329 {
1330 	struct uart_port *port = &s->port;
1331 	u16 scr;
1332 
1333 	/* Direct new serial port interrupts back to CPU */
1334 	scr = sci_serial_in(port, SCSCR);
1335 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1336 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1337 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1338 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1339 			scif_set_rtrg(port, s->rx_trigger);
1340 		else
1341 			scr &= ~SCSCR_RDRQE;
1342 	}
1343 	sci_serial_out(port, SCSCR, scr | SCSCR_RIE);
1344 }
1345 
1346 static void sci_dma_rx_complete(void *arg)
1347 {
1348 	struct sci_port *s = arg;
1349 	struct dma_chan *chan = s->chan_rx;
1350 	struct uart_port *port = &s->port;
1351 	struct dma_async_tx_descriptor *desc;
1352 	unsigned long flags;
1353 	int active, count = 0;
1354 
1355 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1356 		s->active_rx);
1357 
1358 	hrtimer_cancel(&s->rx_timer);
1359 
1360 	uart_port_lock_irqsave(port, &flags);
1361 
1362 	active = sci_dma_rx_find_active(s);
1363 	if (active >= 0)
1364 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1365 
1366 	if (count)
1367 		tty_flip_buffer_push(&port->state->port);
1368 
1369 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1370 				       DMA_DEV_TO_MEM,
1371 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1372 	if (!desc)
1373 		goto fail;
1374 
1375 	desc->callback = sci_dma_rx_complete;
1376 	desc->callback_param = s;
1377 	s->cookie_rx[active] = dmaengine_submit(desc);
1378 	if (dma_submit_error(s->cookie_rx[active]))
1379 		goto fail;
1380 
1381 	s->active_rx = s->cookie_rx[!active];
1382 
1383 	dma_async_issue_pending(chan);
1384 
1385 	uart_port_unlock_irqrestore(port, flags);
1386 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1387 		__func__, s->cookie_rx[active], active, s->active_rx);
1388 
1389 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1390 
1391 	return;
1392 
1393 fail:
1394 	/* Switch to PIO */
1395 	dmaengine_terminate_async(chan);
1396 	sci_dma_rx_chan_invalidate(s);
1397 	sci_dma_rx_reenable_irq(s);
1398 	uart_port_unlock_irqrestore(port, flags);
1399 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1400 }
1401 
1402 static void sci_dma_tx_release(struct sci_port *s)
1403 {
1404 	struct dma_chan *chan = s->chan_tx_saved;
1405 
1406 	cancel_work_sync(&s->work_tx);
1407 	s->chan_tx_saved = s->chan_tx = NULL;
1408 	s->cookie_tx = -EINVAL;
1409 	dmaengine_terminate_sync(chan);
1410 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1411 			 DMA_TO_DEVICE);
1412 	dma_release_channel(chan);
1413 }
1414 
1415 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1416 {
1417 	struct dma_chan *chan = s->chan_rx;
1418 	struct uart_port *port = &s->port;
1419 	unsigned long flags;
1420 	int i;
1421 
1422 	for (i = 0; i < 2; i++) {
1423 		struct scatterlist *sg = &s->sg_rx[i];
1424 		struct dma_async_tx_descriptor *desc;
1425 
1426 		desc = dmaengine_prep_slave_sg(chan,
1427 			sg, 1, DMA_DEV_TO_MEM,
1428 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1429 		if (!desc)
1430 			goto fail;
1431 
1432 		desc->callback = sci_dma_rx_complete;
1433 		desc->callback_param = s;
1434 		s->cookie_rx[i] = dmaengine_submit(desc);
1435 		if (dma_submit_error(s->cookie_rx[i]))
1436 			goto fail;
1437 
1438 	}
1439 
1440 	s->active_rx = s->cookie_rx[0];
1441 
1442 	dma_async_issue_pending(chan);
1443 	return 0;
1444 
1445 fail:
1446 	/* Switch to PIO */
1447 	if (!port_lock_held)
1448 		uart_port_lock_irqsave(port, &flags);
1449 	if (i)
1450 		dmaengine_terminate_async(chan);
1451 	sci_dma_rx_chan_invalidate(s);
1452 	sci_start_rx(port);
1453 	if (!port_lock_held)
1454 		uart_port_unlock_irqrestore(port, flags);
1455 	return -EAGAIN;
1456 }
1457 
1458 static void sci_dma_tx_work_fn(struct work_struct *work)
1459 {
1460 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1461 	struct dma_async_tx_descriptor *desc;
1462 	struct dma_chan *chan = s->chan_tx;
1463 	struct uart_port *port = &s->port;
1464 	struct tty_port *tport = &port->state->port;
1465 	unsigned long flags;
1466 	unsigned int tail;
1467 	dma_addr_t buf;
1468 
1469 	/*
1470 	 * DMA is idle now.
1471 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1472 	 * offsets and lengths. Since it is a circular buffer, we have to
1473 	 * transmit till the end, and then the rest. Take the port lock to get a
1474 	 * consistent xmit buffer state.
1475 	 */
1476 	uart_port_lock_irq(port);
1477 	s->tx_dma_len = kfifo_out_linear(&tport->xmit_fifo, &tail,
1478 			UART_XMIT_SIZE);
1479 	buf = s->tx_dma_addr + tail;
1480 	if (!s->tx_dma_len) {
1481 		/* Transmit buffer has been flushed */
1482 		uart_port_unlock_irq(port);
1483 		return;
1484 	}
1485 
1486 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1487 					   DMA_MEM_TO_DEV,
1488 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1489 	if (!desc) {
1490 		uart_port_unlock_irq(port);
1491 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1492 		goto switch_to_pio;
1493 	}
1494 
1495 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1496 				   DMA_TO_DEVICE);
1497 
1498 	desc->callback = sci_dma_tx_complete;
1499 	desc->callback_param = s;
1500 	s->cookie_tx = dmaengine_submit(desc);
1501 	if (dma_submit_error(s->cookie_tx)) {
1502 		uart_port_unlock_irq(port);
1503 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1504 		goto switch_to_pio;
1505 	}
1506 
1507 	uart_port_unlock_irq(port);
1508 	dev_dbg(port->dev, "%s: %p: %u, cookie %d\n",
1509 		__func__, tport->xmit_buf, tail, s->cookie_tx);
1510 
1511 	dma_async_issue_pending(chan);
1512 	return;
1513 
1514 switch_to_pio:
1515 	uart_port_lock_irqsave(port, &flags);
1516 	s->chan_tx = NULL;
1517 	sci_start_tx(port);
1518 	uart_port_unlock_irqrestore(port, flags);
1519 	return;
1520 }
1521 
1522 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1523 {
1524 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1525 	struct dma_chan *chan = s->chan_rx;
1526 	struct uart_port *port = &s->port;
1527 	struct dma_tx_state state;
1528 	enum dma_status status;
1529 	unsigned long flags;
1530 	unsigned int read;
1531 	int active, count;
1532 
1533 	dev_dbg(port->dev, "DMA Rx timed out\n");
1534 
1535 	uart_port_lock_irqsave(port, &flags);
1536 
1537 	active = sci_dma_rx_find_active(s);
1538 	if (active < 0) {
1539 		uart_port_unlock_irqrestore(port, flags);
1540 		return HRTIMER_NORESTART;
1541 	}
1542 
1543 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1544 	if (status == DMA_COMPLETE) {
1545 		uart_port_unlock_irqrestore(port, flags);
1546 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1547 			s->active_rx, active);
1548 
1549 		/* Let packet complete handler take care of the packet */
1550 		return HRTIMER_NORESTART;
1551 	}
1552 
1553 	dmaengine_pause(chan);
1554 
1555 	/*
1556 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1557 	 * data keeps on coming until transaction is complete so check
1558 	 * for DMA_COMPLETE again
1559 	 * Let packet complete handler take care of the packet
1560 	 */
1561 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1562 	if (status == DMA_COMPLETE) {
1563 		uart_port_unlock_irqrestore(port, flags);
1564 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1565 		return HRTIMER_NORESTART;
1566 	}
1567 
1568 	/* Handle incomplete DMA receive */
1569 	dmaengine_terminate_async(s->chan_rx);
1570 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1571 
1572 	if (read) {
1573 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1574 		if (count)
1575 			tty_flip_buffer_push(&port->state->port);
1576 	}
1577 
1578 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1579 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1580 		sci_dma_rx_submit(s, true);
1581 
1582 	sci_dma_rx_reenable_irq(s);
1583 
1584 	uart_port_unlock_irqrestore(port, flags);
1585 
1586 	return HRTIMER_NORESTART;
1587 }
1588 
1589 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1590 					     enum dma_transfer_direction dir)
1591 {
1592 	struct dma_chan *chan;
1593 	struct dma_slave_config cfg;
1594 	int ret;
1595 
1596 	chan = dma_request_chan(port->dev, dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1597 	if (IS_ERR(chan)) {
1598 		dev_dbg(port->dev, "dma_request_chan failed\n");
1599 		return NULL;
1600 	}
1601 
1602 	memset(&cfg, 0, sizeof(cfg));
1603 	cfg.direction = dir;
1604 	cfg.dst_addr = port->mapbase +
1605 		(sci_getreg(port, SCxTDR)->offset << port->regshift);
1606 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1607 	cfg.src_addr = port->mapbase +
1608 		(sci_getreg(port, SCxRDR)->offset << port->regshift);
1609 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1610 
1611 	ret = dmaengine_slave_config(chan, &cfg);
1612 	if (ret) {
1613 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1614 		dma_release_channel(chan);
1615 		return NULL;
1616 	}
1617 
1618 	return chan;
1619 }
1620 
1621 static void sci_request_dma(struct uart_port *port)
1622 {
1623 	struct sci_port *s = to_sci_port(port);
1624 	struct tty_port *tport = &port->state->port;
1625 	struct dma_chan *chan;
1626 
1627 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1628 
1629 	/*
1630 	 * DMA on console may interfere with Kernel log messages which use
1631 	 * plain putchar(). So, simply don't use it with a console.
1632 	 */
1633 	if (uart_console(port))
1634 		return;
1635 
1636 	if (!port->dev->of_node)
1637 		return;
1638 
1639 	s->cookie_tx = -EINVAL;
1640 
1641 	/*
1642 	 * Don't request a dma channel if no channel was specified
1643 	 * in the device tree.
1644 	 */
1645 	if (!of_property_present(port->dev->of_node, "dmas"))
1646 		return;
1647 
1648 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1649 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1650 	if (chan) {
1651 		/* UART circular tx buffer is an aligned page. */
1652 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1653 						tport->xmit_buf,
1654 						UART_XMIT_SIZE,
1655 						DMA_TO_DEVICE);
1656 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1657 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1658 			dma_release_channel(chan);
1659 		} else {
1660 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1661 				__func__, UART_XMIT_SIZE,
1662 				tport->xmit_buf, &s->tx_dma_addr);
1663 
1664 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1665 			s->chan_tx_saved = s->chan_tx = chan;
1666 		}
1667 	}
1668 
1669 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1670 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1671 	if (chan) {
1672 		unsigned int i;
1673 		dma_addr_t dma;
1674 		void *buf;
1675 
1676 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1677 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1678 					 &dma, GFP_KERNEL);
1679 		if (!buf) {
1680 			dev_warn(port->dev,
1681 				 "Failed to allocate Rx dma buffer, using PIO\n");
1682 			dma_release_channel(chan);
1683 			return;
1684 		}
1685 
1686 		for (i = 0; i < 2; i++) {
1687 			struct scatterlist *sg = &s->sg_rx[i];
1688 
1689 			sg_init_table(sg, 1);
1690 			s->rx_buf[i] = buf;
1691 			sg_dma_address(sg) = dma;
1692 			sg_dma_len(sg) = s->buf_len_rx;
1693 
1694 			buf += s->buf_len_rx;
1695 			dma += s->buf_len_rx;
1696 		}
1697 
1698 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1699 		s->rx_timer.function = sci_dma_rx_timer_fn;
1700 
1701 		s->chan_rx_saved = s->chan_rx = chan;
1702 
1703 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1704 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1705 			sci_dma_rx_submit(s, false);
1706 	}
1707 }
1708 
1709 static void sci_free_dma(struct uart_port *port)
1710 {
1711 	struct sci_port *s = to_sci_port(port);
1712 
1713 	if (s->chan_tx_saved)
1714 		sci_dma_tx_release(s);
1715 	if (s->chan_rx_saved)
1716 		sci_dma_rx_release(s);
1717 }
1718 
1719 static void sci_flush_buffer(struct uart_port *port)
1720 {
1721 	struct sci_port *s = to_sci_port(port);
1722 
1723 	/*
1724 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1725 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1726 	 * pending transfers
1727 	 */
1728 	s->tx_dma_len = 0;
1729 	if (s->chan_tx) {
1730 		dmaengine_terminate_async(s->chan_tx);
1731 		s->cookie_tx = -EINVAL;
1732 	}
1733 }
1734 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1735 static inline void sci_request_dma(struct uart_port *port)
1736 {
1737 }
1738 
1739 static inline void sci_free_dma(struct uart_port *port)
1740 {
1741 }
1742 
1743 #define sci_flush_buffer	NULL
1744 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1745 
1746 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1747 {
1748 	struct uart_port *port = ptr;
1749 	struct sci_port *s = to_sci_port(port);
1750 
1751 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1752 	if (s->chan_rx) {
1753 		u16 scr = sci_serial_in(port, SCSCR);
1754 		u16 ssr = sci_serial_in(port, SCxSR);
1755 
1756 		/* Disable future Rx interrupts */
1757 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1758 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1759 			disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
1760 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1761 				scif_set_rtrg(port, 1);
1762 				scr |= SCSCR_RIE;
1763 			} else {
1764 				scr |= SCSCR_RDRQE;
1765 			}
1766 		} else {
1767 			if (sci_dma_rx_submit(s, false) < 0)
1768 				goto handle_pio;
1769 
1770 			scr &= ~SCSCR_RIE;
1771 		}
1772 		sci_serial_out(port, SCSCR, scr);
1773 		/* Clear current interrupt */
1774 		sci_serial_out(port, SCxSR,
1775 			       ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1776 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1777 			jiffies, s->rx_timeout);
1778 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1779 
1780 		return IRQ_HANDLED;
1781 	}
1782 
1783 handle_pio:
1784 #endif
1785 
1786 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1787 		if (!scif_rtrg_enabled(port))
1788 			scif_set_rtrg(port, s->rx_trigger);
1789 
1790 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1791 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1792 	}
1793 
1794 	/* I think sci_receive_chars has to be called irrespective
1795 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1796 	 * to be disabled?
1797 	 */
1798 	sci_receive_chars(port);
1799 
1800 	return IRQ_HANDLED;
1801 }
1802 
1803 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1804 {
1805 	struct uart_port *port = ptr;
1806 	unsigned long flags;
1807 
1808 	uart_port_lock_irqsave(port, &flags);
1809 	sci_transmit_chars(port);
1810 	uart_port_unlock_irqrestore(port, flags);
1811 
1812 	return IRQ_HANDLED;
1813 }
1814 
1815 static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
1816 {
1817 	struct uart_port *port = ptr;
1818 	unsigned long flags;
1819 	unsigned short ctrl;
1820 
1821 	if (port->type != PORT_SCI)
1822 		return sci_tx_interrupt(irq, ptr);
1823 
1824 	uart_port_lock_irqsave(port, &flags);
1825 	ctrl = sci_serial_in(port, SCSCR);
1826 	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
1827 	sci_serial_out(port, SCSCR, ctrl);
1828 	uart_port_unlock_irqrestore(port, flags);
1829 
1830 	return IRQ_HANDLED;
1831 }
1832 
1833 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1834 {
1835 	struct uart_port *port = ptr;
1836 
1837 	/* Handle BREAKs */
1838 	sci_handle_breaks(port);
1839 
1840 	/* drop invalid character received before break was detected */
1841 	sci_serial_in(port, SCxRDR);
1842 
1843 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1844 
1845 	return IRQ_HANDLED;
1846 }
1847 
1848 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1849 {
1850 	struct uart_port *port = ptr;
1851 	struct sci_port *s = to_sci_port(port);
1852 
1853 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1854 		/* Break and Error interrupts are muxed */
1855 		unsigned short ssr_status = sci_serial_in(port, SCxSR);
1856 
1857 		/* Break Interrupt */
1858 		if (ssr_status & SCxSR_BRK(port))
1859 			sci_br_interrupt(irq, ptr);
1860 
1861 		/* Break only? */
1862 		if (!(ssr_status & SCxSR_ERRORS(port)))
1863 			return IRQ_HANDLED;
1864 	}
1865 
1866 	/* Handle errors */
1867 	if (port->type == PORT_SCI) {
1868 		if (sci_handle_errors(port)) {
1869 			/* discard character in rx buffer */
1870 			sci_serial_in(port, SCxSR);
1871 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1872 		}
1873 	} else {
1874 		sci_handle_fifo_overrun(port);
1875 		if (!s->chan_rx)
1876 			sci_receive_chars(port);
1877 	}
1878 
1879 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1880 
1881 	/* Kick the transmission */
1882 	if (!s->chan_tx)
1883 		sci_tx_interrupt(irq, ptr);
1884 
1885 	return IRQ_HANDLED;
1886 }
1887 
1888 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1889 {
1890 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1891 	struct uart_port *port = ptr;
1892 	struct sci_port *s = to_sci_port(port);
1893 	irqreturn_t ret = IRQ_NONE;
1894 
1895 	ssr_status = sci_serial_in(port, SCxSR);
1896 	scr_status = sci_serial_in(port, SCSCR);
1897 	if (s->params->overrun_reg == SCxSR)
1898 		orer_status = ssr_status;
1899 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1900 		orer_status = sci_serial_in(port, s->params->overrun_reg);
1901 
1902 	err_enabled = scr_status & port_rx_irq_mask(port);
1903 
1904 	/* Tx Interrupt */
1905 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1906 	    !s->chan_tx)
1907 		ret = sci_tx_interrupt(irq, ptr);
1908 
1909 	/*
1910 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1911 	 * DR flags
1912 	 */
1913 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1914 	    (scr_status & SCSCR_RIE))
1915 		ret = sci_rx_interrupt(irq, ptr);
1916 
1917 	/* Error Interrupt */
1918 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1919 		ret = sci_er_interrupt(irq, ptr);
1920 
1921 	/* Break Interrupt */
1922 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1923 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1924 		ret = sci_br_interrupt(irq, ptr);
1925 
1926 	/* Overrun Interrupt */
1927 	if (orer_status & s->params->overrun_mask) {
1928 		sci_handle_fifo_overrun(port);
1929 		ret = IRQ_HANDLED;
1930 	}
1931 
1932 	return ret;
1933 }
1934 
1935 static const struct sci_irq_desc {
1936 	const char	*desc;
1937 	irq_handler_t	handler;
1938 } sci_irq_desc[] = {
1939 	/*
1940 	 * Split out handlers, the default case.
1941 	 */
1942 	[SCIx_ERI_IRQ] = {
1943 		.desc = "rx err",
1944 		.handler = sci_er_interrupt,
1945 	},
1946 
1947 	[SCIx_RXI_IRQ] = {
1948 		.desc = "rx full",
1949 		.handler = sci_rx_interrupt,
1950 	},
1951 
1952 	[SCIx_TXI_IRQ] = {
1953 		.desc = "tx empty",
1954 		.handler = sci_tx_interrupt,
1955 	},
1956 
1957 	[SCIx_BRI_IRQ] = {
1958 		.desc = "break",
1959 		.handler = sci_br_interrupt,
1960 	},
1961 
1962 	[SCIx_DRI_IRQ] = {
1963 		.desc = "rx ready",
1964 		.handler = sci_rx_interrupt,
1965 	},
1966 
1967 	[SCIx_TEI_IRQ] = {
1968 		.desc = "tx end",
1969 		.handler = sci_tx_end_interrupt,
1970 	},
1971 
1972 	/*
1973 	 * Special muxed handler.
1974 	 */
1975 	[SCIx_MUX_IRQ] = {
1976 		.desc = "mux",
1977 		.handler = sci_mpxed_interrupt,
1978 	},
1979 };
1980 
1981 static int sci_request_irq(struct sci_port *port)
1982 {
1983 	struct uart_port *up = &port->port;
1984 	int i, j, w, ret = 0;
1985 
1986 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1987 		const struct sci_irq_desc *desc;
1988 		int irq;
1989 
1990 		/* Check if already registered (muxed) */
1991 		for (w = 0; w < i; w++)
1992 			if (port->irqs[w] == port->irqs[i])
1993 				w = i + 1;
1994 		if (w > i)
1995 			continue;
1996 
1997 		if (SCIx_IRQ_IS_MUXED(port)) {
1998 			i = SCIx_MUX_IRQ;
1999 			irq = up->irq;
2000 		} else {
2001 			irq = port->irqs[i];
2002 
2003 			/*
2004 			 * Certain port types won't support all of the
2005 			 * available interrupt sources.
2006 			 */
2007 			if (unlikely(irq < 0))
2008 				continue;
2009 		}
2010 
2011 		desc = sci_irq_desc + i;
2012 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
2013 					    dev_name(up->dev), desc->desc);
2014 		if (!port->irqstr[j]) {
2015 			ret = -ENOMEM;
2016 			goto out_nomem;
2017 		}
2018 
2019 		ret = request_irq(irq, desc->handler, up->irqflags,
2020 				  port->irqstr[j], port);
2021 		if (unlikely(ret)) {
2022 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
2023 			goto out_noirq;
2024 		}
2025 	}
2026 
2027 	return 0;
2028 
2029 out_noirq:
2030 	while (--i >= 0)
2031 		free_irq(port->irqs[i], port);
2032 
2033 out_nomem:
2034 	while (--j >= 0)
2035 		kfree(port->irqstr[j]);
2036 
2037 	return ret;
2038 }
2039 
2040 static void sci_free_irq(struct sci_port *port)
2041 {
2042 	int i, j;
2043 
2044 	/*
2045 	 * Intentionally in reverse order so we iterate over the muxed
2046 	 * IRQ first.
2047 	 */
2048 	for (i = 0; i < SCIx_NR_IRQS; i++) {
2049 		int irq = port->irqs[i];
2050 
2051 		/*
2052 		 * Certain port types won't support all of the available
2053 		 * interrupt sources.
2054 		 */
2055 		if (unlikely(irq < 0))
2056 			continue;
2057 
2058 		/* Check if already freed (irq was muxed) */
2059 		for (j = 0; j < i; j++)
2060 			if (port->irqs[j] == irq)
2061 				j = i + 1;
2062 		if (j > i)
2063 			continue;
2064 
2065 		free_irq(port->irqs[i], port);
2066 		kfree(port->irqstr[i]);
2067 
2068 		if (SCIx_IRQ_IS_MUXED(port)) {
2069 			/* If there's only one IRQ, we're done. */
2070 			return;
2071 		}
2072 	}
2073 }
2074 
2075 static unsigned int sci_tx_empty(struct uart_port *port)
2076 {
2077 	unsigned short status = sci_serial_in(port, SCxSR);
2078 	unsigned short in_tx_fifo = sci_txfill(port);
2079 
2080 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2081 }
2082 
2083 static void sci_set_rts(struct uart_port *port, bool state)
2084 {
2085 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2086 		u16 data = sci_serial_in(port, SCPDR);
2087 
2088 		/* Active low */
2089 		if (state)
2090 			data &= ~SCPDR_RTSD;
2091 		else
2092 			data |= SCPDR_RTSD;
2093 		sci_serial_out(port, SCPDR, data);
2094 
2095 		/* RTS# is output */
2096 		sci_serial_out(port, SCPCR,
2097 			       sci_serial_in(port, SCPCR) | SCPCR_RTSC);
2098 	} else if (sci_getreg(port, SCSPTR)->size) {
2099 		u16 ctrl = sci_serial_in(port, SCSPTR);
2100 
2101 		/* Active low */
2102 		if (state)
2103 			ctrl &= ~SCSPTR_RTSDT;
2104 		else
2105 			ctrl |= SCSPTR_RTSDT;
2106 		sci_serial_out(port, SCSPTR, ctrl);
2107 	}
2108 }
2109 
2110 static bool sci_get_cts(struct uart_port *port)
2111 {
2112 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2113 		/* Active low */
2114 		return !(sci_serial_in(port, SCPDR) & SCPDR_CTSD);
2115 	} else if (sci_getreg(port, SCSPTR)->size) {
2116 		/* Active low */
2117 		return !(sci_serial_in(port, SCSPTR) & SCSPTR_CTSDT);
2118 	}
2119 
2120 	return true;
2121 }
2122 
2123 /*
2124  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2125  * CTS/RTS is supported in hardware by at least one port and controlled
2126  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2127  * handled via the ->init_pins() op, which is a bit of a one-way street,
2128  * lacking any ability to defer pin control -- this will later be
2129  * converted over to the GPIO framework).
2130  *
2131  * Other modes (such as loopback) are supported generically on certain
2132  * port types, but not others. For these it's sufficient to test for the
2133  * existence of the support register and simply ignore the port type.
2134  */
2135 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2136 {
2137 	struct sci_port *s = to_sci_port(port);
2138 
2139 	if (mctrl & TIOCM_LOOP) {
2140 		const struct plat_sci_reg *reg;
2141 
2142 		/*
2143 		 * Standard loopback mode for SCFCR ports.
2144 		 */
2145 		reg = sci_getreg(port, SCFCR);
2146 		if (reg->size)
2147 			sci_serial_out(port, SCFCR,
2148 				       sci_serial_in(port, SCFCR) | SCFCR_LOOP);
2149 	}
2150 
2151 	mctrl_gpio_set(s->gpios, mctrl);
2152 
2153 	if (!s->has_rtscts)
2154 		return;
2155 
2156 	if (!(mctrl & TIOCM_RTS)) {
2157 		/* Disable Auto RTS */
2158 		if (s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE)
2159 			sci_serial_out(port, SCFCR,
2160 				       sci_serial_in(port, SCFCR) & ~SCFCR_MCE);
2161 
2162 		/* Clear RTS */
2163 		sci_set_rts(port, 0);
2164 	} else if (s->autorts) {
2165 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2166 			/* Enable RTS# pin function */
2167 			sci_serial_out(port, SCPCR,
2168 				sci_serial_in(port, SCPCR) & ~SCPCR_RTSC);
2169 		}
2170 
2171 		/* Enable Auto RTS */
2172 		if (s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE)
2173 			sci_serial_out(port, SCFCR,
2174 				       sci_serial_in(port, SCFCR) | SCFCR_MCE);
2175 	} else {
2176 		/* Set RTS */
2177 		sci_set_rts(port, 1);
2178 	}
2179 }
2180 
2181 static unsigned int sci_get_mctrl(struct uart_port *port)
2182 {
2183 	struct sci_port *s = to_sci_port(port);
2184 	struct mctrl_gpios *gpios = s->gpios;
2185 	unsigned int mctrl = 0;
2186 
2187 	mctrl_gpio_get(gpios, &mctrl);
2188 
2189 	/*
2190 	 * CTS/RTS is handled in hardware when supported, while nothing
2191 	 * else is wired up.
2192 	 */
2193 	if (s->autorts) {
2194 		if (sci_get_cts(port))
2195 			mctrl |= TIOCM_CTS;
2196 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2197 		mctrl |= TIOCM_CTS;
2198 	}
2199 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2200 		mctrl |= TIOCM_DSR;
2201 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2202 		mctrl |= TIOCM_CAR;
2203 
2204 	return mctrl;
2205 }
2206 
2207 static void sci_enable_ms(struct uart_port *port)
2208 {
2209 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2210 }
2211 
2212 static void sci_break_ctl(struct uart_port *port, int break_state)
2213 {
2214 	unsigned short scscr, scsptr;
2215 	unsigned long flags;
2216 
2217 	/* check whether the port has SCSPTR */
2218 	if (!sci_getreg(port, SCSPTR)->size) {
2219 		/*
2220 		 * Not supported by hardware. Most parts couple break and rx
2221 		 * interrupts together, with break detection always enabled.
2222 		 */
2223 		return;
2224 	}
2225 
2226 	uart_port_lock_irqsave(port, &flags);
2227 	scsptr = sci_serial_in(port, SCSPTR);
2228 	scscr = sci_serial_in(port, SCSCR);
2229 
2230 	if (break_state == -1) {
2231 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2232 		scscr &= ~SCSCR_TE;
2233 	} else {
2234 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2235 		scscr |= SCSCR_TE;
2236 	}
2237 
2238 	sci_serial_out(port, SCSPTR, scsptr);
2239 	sci_serial_out(port, SCSCR, scscr);
2240 	uart_port_unlock_irqrestore(port, flags);
2241 }
2242 
2243 static int sci_startup(struct uart_port *port)
2244 {
2245 	struct sci_port *s = to_sci_port(port);
2246 	int ret;
2247 
2248 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2249 
2250 	sci_request_dma(port);
2251 
2252 	ret = sci_request_irq(s);
2253 	if (unlikely(ret < 0)) {
2254 		sci_free_dma(port);
2255 		return ret;
2256 	}
2257 
2258 	return 0;
2259 }
2260 
2261 static void sci_shutdown(struct uart_port *port)
2262 {
2263 	struct sci_port *s = to_sci_port(port);
2264 	unsigned long flags;
2265 	u16 scr;
2266 
2267 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2268 
2269 	s->autorts = false;
2270 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2271 
2272 	uart_port_lock_irqsave(port, &flags);
2273 	sci_stop_rx(port);
2274 	sci_stop_tx(port);
2275 	/*
2276 	 * Stop RX and TX, disable related interrupts, keep clock source
2277 	 * and HSCIF TOT bits
2278 	 */
2279 	scr = sci_serial_in(port, SCSCR);
2280 	sci_serial_out(port, SCSCR,
2281 		       scr & (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2282 	uart_port_unlock_irqrestore(port, flags);
2283 
2284 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2285 	if (s->chan_rx_saved) {
2286 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2287 			port->line);
2288 		hrtimer_cancel(&s->rx_timer);
2289 	}
2290 #endif
2291 
2292 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2293 		del_timer_sync(&s->rx_fifo_timer);
2294 	sci_free_irq(s);
2295 	sci_free_dma(port);
2296 }
2297 
2298 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2299 			unsigned int *srr)
2300 {
2301 	unsigned long freq = s->clk_rates[SCI_SCK];
2302 	int err, min_err = INT_MAX;
2303 	unsigned int sr;
2304 
2305 	if (s->port.type != PORT_HSCIF)
2306 		freq *= 2;
2307 
2308 	for_each_sr(sr, s) {
2309 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2310 		if (abs(err) >= abs(min_err))
2311 			continue;
2312 
2313 		min_err = err;
2314 		*srr = sr - 1;
2315 
2316 		if (!err)
2317 			break;
2318 	}
2319 
2320 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2321 		*srr + 1);
2322 	return min_err;
2323 }
2324 
2325 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2326 			unsigned long freq, unsigned int *dlr,
2327 			unsigned int *srr)
2328 {
2329 	int err, min_err = INT_MAX;
2330 	unsigned int sr, dl;
2331 
2332 	if (s->port.type != PORT_HSCIF)
2333 		freq *= 2;
2334 
2335 	for_each_sr(sr, s) {
2336 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2337 		dl = clamp(dl, 1U, 65535U);
2338 
2339 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2340 		if (abs(err) >= abs(min_err))
2341 			continue;
2342 
2343 		min_err = err;
2344 		*dlr = dl;
2345 		*srr = sr - 1;
2346 
2347 		if (!err)
2348 			break;
2349 	}
2350 
2351 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2352 		min_err, *dlr, *srr + 1);
2353 	return min_err;
2354 }
2355 
2356 /* calculate sample rate, BRR, and clock select */
2357 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2358 			  unsigned int *brr, unsigned int *srr,
2359 			  unsigned int *cks)
2360 {
2361 	unsigned long freq = s->clk_rates[SCI_FCK];
2362 	unsigned int sr, br, prediv, scrate, c;
2363 	int err, min_err = INT_MAX;
2364 
2365 	if (s->port.type != PORT_HSCIF)
2366 		freq *= 2;
2367 
2368 	/*
2369 	 * Find the combination of sample rate and clock select with the
2370 	 * smallest deviation from the desired baud rate.
2371 	 * Prefer high sample rates to maximise the receive margin.
2372 	 *
2373 	 * M: Receive margin (%)
2374 	 * N: Ratio of bit rate to clock (N = sampling rate)
2375 	 * D: Clock duty (D = 0 to 1.0)
2376 	 * L: Frame length (L = 9 to 12)
2377 	 * F: Absolute value of clock frequency deviation
2378 	 *
2379 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2380 	 *      (|D - 0.5| / N * (1 + F))|
2381 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2382 	 */
2383 	for_each_sr(sr, s) {
2384 		for (c = 0; c <= 3; c++) {
2385 			/* integerized formulas from HSCIF documentation */
2386 			prediv = sr << (2 * c + 1);
2387 
2388 			/*
2389 			 * We need to calculate:
2390 			 *
2391 			 *     br = freq / (prediv * bps) clamped to [1..256]
2392 			 *     err = freq / (br * prediv) - bps
2393 			 *
2394 			 * Watch out for overflow when calculating the desired
2395 			 * sampling clock rate!
2396 			 */
2397 			if (bps > UINT_MAX / prediv)
2398 				break;
2399 
2400 			scrate = prediv * bps;
2401 			br = DIV_ROUND_CLOSEST(freq, scrate);
2402 			br = clamp(br, 1U, 256U);
2403 
2404 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2405 			if (abs(err) >= abs(min_err))
2406 				continue;
2407 
2408 			min_err = err;
2409 			*brr = br - 1;
2410 			*srr = sr - 1;
2411 			*cks = c;
2412 
2413 			if (!err)
2414 				goto found;
2415 		}
2416 	}
2417 
2418 found:
2419 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2420 		min_err, *brr, *srr + 1, *cks);
2421 	return min_err;
2422 }
2423 
2424 static void sci_reset(struct uart_port *port)
2425 {
2426 	const struct plat_sci_reg *reg;
2427 	unsigned int status;
2428 	struct sci_port *s = to_sci_port(port);
2429 
2430 	sci_serial_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2431 
2432 	reg = sci_getreg(port, SCFCR);
2433 	if (reg->size)
2434 		sci_serial_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2435 
2436 	sci_clear_SCxSR(port,
2437 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2438 			SCxSR_BREAK_CLEAR(port));
2439 	if (sci_getreg(port, SCLSR)->size) {
2440 		status = sci_serial_in(port, SCLSR);
2441 		status &= ~(SCLSR_TO | SCLSR_ORER);
2442 		sci_serial_out(port, SCLSR, status);
2443 	}
2444 
2445 	if (s->rx_trigger > 1) {
2446 		if (s->rx_fifo_timeout) {
2447 			scif_set_rtrg(port, 1);
2448 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2449 		} else {
2450 			if (port->type == PORT_SCIFA ||
2451 			    port->type == PORT_SCIFB)
2452 				scif_set_rtrg(port, 1);
2453 			else
2454 				scif_set_rtrg(port, s->rx_trigger);
2455 		}
2456 	}
2457 }
2458 
2459 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2460 		            const struct ktermios *old)
2461 {
2462 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2463 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2464 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2465 	struct sci_port *s = to_sci_port(port);
2466 	const struct plat_sci_reg *reg;
2467 	int min_err = INT_MAX, err;
2468 	unsigned long max_freq = 0;
2469 	int best_clk = -1;
2470 	unsigned long flags;
2471 
2472 	if ((termios->c_cflag & CSIZE) == CS7) {
2473 		smr_val |= SCSMR_CHR;
2474 	} else {
2475 		termios->c_cflag &= ~CSIZE;
2476 		termios->c_cflag |= CS8;
2477 	}
2478 	if (termios->c_cflag & PARENB)
2479 		smr_val |= SCSMR_PE;
2480 	if (termios->c_cflag & PARODD)
2481 		smr_val |= SCSMR_PE | SCSMR_ODD;
2482 	if (termios->c_cflag & CSTOPB)
2483 		smr_val |= SCSMR_STOP;
2484 
2485 	/*
2486 	 * earlyprintk comes here early on with port->uartclk set to zero.
2487 	 * the clock framework is not up and running at this point so here
2488 	 * we assume that 115200 is the maximum baud rate. please note that
2489 	 * the baud rate is not programmed during earlyprintk - it is assumed
2490 	 * that the previous boot loader has enabled required clocks and
2491 	 * setup the baud rate generator hardware for us already.
2492 	 */
2493 	if (!port->uartclk) {
2494 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2495 		goto done;
2496 	}
2497 
2498 	for (i = 0; i < SCI_NUM_CLKS; i++)
2499 		max_freq = max(max_freq, s->clk_rates[i]);
2500 
2501 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2502 	if (!baud)
2503 		goto done;
2504 
2505 	/*
2506 	 * There can be multiple sources for the sampling clock.  Find the one
2507 	 * that gives us the smallest deviation from the desired baud rate.
2508 	 */
2509 
2510 	/* Optional Undivided External Clock */
2511 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2512 	    port->type != PORT_SCIFB) {
2513 		err = sci_sck_calc(s, baud, &srr1);
2514 		if (abs(err) < abs(min_err)) {
2515 			best_clk = SCI_SCK;
2516 			scr_val = SCSCR_CKE1;
2517 			sccks = SCCKS_CKS;
2518 			min_err = err;
2519 			srr = srr1;
2520 			if (!err)
2521 				goto done;
2522 		}
2523 	}
2524 
2525 	/* Optional BRG Frequency Divided External Clock */
2526 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2527 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2528 				   &srr1);
2529 		if (abs(err) < abs(min_err)) {
2530 			best_clk = SCI_SCIF_CLK;
2531 			scr_val = SCSCR_CKE1;
2532 			sccks = 0;
2533 			min_err = err;
2534 			dl = dl1;
2535 			srr = srr1;
2536 			if (!err)
2537 				goto done;
2538 		}
2539 	}
2540 
2541 	/* Optional BRG Frequency Divided Internal Clock */
2542 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2543 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2544 				   &srr1);
2545 		if (abs(err) < abs(min_err)) {
2546 			best_clk = SCI_BRG_INT;
2547 			scr_val = SCSCR_CKE1;
2548 			sccks = SCCKS_XIN;
2549 			min_err = err;
2550 			dl = dl1;
2551 			srr = srr1;
2552 			if (!min_err)
2553 				goto done;
2554 		}
2555 	}
2556 
2557 	/* Divided Functional Clock using standard Bit Rate Register */
2558 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2559 	if (abs(err) < abs(min_err)) {
2560 		best_clk = SCI_FCK;
2561 		scr_val = 0;
2562 		min_err = err;
2563 		brr = brr1;
2564 		srr = srr1;
2565 		cks = cks1;
2566 	}
2567 
2568 done:
2569 	if (best_clk >= 0)
2570 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2571 			s->clks[best_clk], baud, min_err);
2572 
2573 	sci_port_enable(s);
2574 
2575 	/*
2576 	 * Program the optional External Baud Rate Generator (BRG) first.
2577 	 * It controls the mux to select (H)SCK or frequency divided clock.
2578 	 */
2579 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2580 		sci_serial_out(port, SCDL, dl);
2581 		sci_serial_out(port, SCCKS, sccks);
2582 	}
2583 
2584 	uart_port_lock_irqsave(port, &flags);
2585 
2586 	sci_reset(port);
2587 
2588 	uart_update_timeout(port, termios->c_cflag, baud);
2589 
2590 	/* byte size and parity */
2591 	bits = tty_get_frame_size(termios->c_cflag);
2592 
2593 	if (sci_getreg(port, SEMR)->size)
2594 		sci_serial_out(port, SEMR, 0);
2595 
2596 	if (best_clk >= 0) {
2597 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2598 			switch (srr + 1) {
2599 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2600 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2601 			case 11: smr_val |= SCSMR_SRC_11; break;
2602 			case 13: smr_val |= SCSMR_SRC_13; break;
2603 			case 16: smr_val |= SCSMR_SRC_16; break;
2604 			case 17: smr_val |= SCSMR_SRC_17; break;
2605 			case 19: smr_val |= SCSMR_SRC_19; break;
2606 			case 27: smr_val |= SCSMR_SRC_27; break;
2607 			}
2608 		smr_val |= cks;
2609 		sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2610 		sci_serial_out(port, SCSMR, smr_val);
2611 		sci_serial_out(port, SCBRR, brr);
2612 		if (sci_getreg(port, HSSRR)->size) {
2613 			unsigned int hssrr = srr | HSCIF_SRE;
2614 			/* Calculate deviation from intended rate at the
2615 			 * center of the last stop bit in sampling clocks.
2616 			 */
2617 			int last_stop = bits * 2 - 1;
2618 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2619 							  (int)(srr + 1),
2620 							  2 * (int)baud);
2621 
2622 			if (abs(deviation) >= 2) {
2623 				/* At least two sampling clocks off at the
2624 				 * last stop bit; we can increase the error
2625 				 * margin by shifting the sampling point.
2626 				 */
2627 				int shift = clamp(deviation / 2, -8, 7);
2628 
2629 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2630 					 HSCIF_SRHP_MASK;
2631 				hssrr |= HSCIF_SRDE;
2632 			}
2633 			sci_serial_out(port, HSSRR, hssrr);
2634 		}
2635 
2636 		/* Wait one bit interval */
2637 		udelay((1000000 + (baud - 1)) / baud);
2638 	} else {
2639 		/* Don't touch the bit rate configuration */
2640 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2641 		smr_val |= sci_serial_in(port, SCSMR) &
2642 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2643 		sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2644 		sci_serial_out(port, SCSMR, smr_val);
2645 	}
2646 
2647 	sci_init_pins(port, termios->c_cflag);
2648 
2649 	port->status &= ~UPSTAT_AUTOCTS;
2650 	s->autorts = false;
2651 	reg = sci_getreg(port, SCFCR);
2652 	if (reg->size) {
2653 		unsigned short ctrl = sci_serial_in(port, SCFCR);
2654 
2655 		if ((port->flags & UPF_HARD_FLOW) &&
2656 		    (termios->c_cflag & CRTSCTS)) {
2657 			/* There is no CTS interrupt to restart the hardware */
2658 			port->status |= UPSTAT_AUTOCTS;
2659 			/* MCE is enabled when RTS is raised */
2660 			s->autorts = true;
2661 		}
2662 
2663 		/*
2664 		 * As we've done a sci_reset() above, ensure we don't
2665 		 * interfere with the FIFOs while toggling MCE. As the
2666 		 * reset values could still be set, simply mask them out.
2667 		 */
2668 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2669 
2670 		sci_serial_out(port, SCFCR, ctrl);
2671 	}
2672 	if (port->flags & UPF_HARD_FLOW) {
2673 		/* Refresh (Auto) RTS */
2674 		sci_set_mctrl(port, port->mctrl);
2675 	}
2676 
2677 	/*
2678 	 * For SCI, TE (transmit enable) must be set after setting TIE
2679 	 * (transmit interrupt enable) or in the same instruction to
2680 	 * start the transmitting process. So skip setting TE here for SCI.
2681 	 */
2682 	if (port->type != PORT_SCI)
2683 		scr_val |= SCSCR_TE;
2684 	scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2685 	sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2686 	if ((srr + 1 == 5) &&
2687 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2688 		/*
2689 		 * In asynchronous mode, when the sampling rate is 1/5, first
2690 		 * received data may become invalid on some SCIFA and SCIFB.
2691 		 * To avoid this problem wait more than 1 serial data time (1
2692 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2693 		 */
2694 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2695 	}
2696 
2697 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2698 	s->rx_frame = (10000 * bits) / (baud / 100);
2699 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2700 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2701 #endif
2702 
2703 	if ((termios->c_cflag & CREAD) != 0)
2704 		sci_start_rx(port);
2705 
2706 	uart_port_unlock_irqrestore(port, flags);
2707 
2708 	sci_port_disable(s);
2709 
2710 	if (UART_ENABLE_MS(port, termios->c_cflag))
2711 		sci_enable_ms(port);
2712 }
2713 
2714 static void sci_pm(struct uart_port *port, unsigned int state,
2715 		   unsigned int oldstate)
2716 {
2717 	struct sci_port *sci_port = to_sci_port(port);
2718 
2719 	switch (state) {
2720 	case UART_PM_STATE_OFF:
2721 		sci_port_disable(sci_port);
2722 		break;
2723 	default:
2724 		sci_port_enable(sci_port);
2725 		break;
2726 	}
2727 }
2728 
2729 static const char *sci_type(struct uart_port *port)
2730 {
2731 	switch (port->type) {
2732 	case PORT_IRDA:
2733 		return "irda";
2734 	case PORT_SCI:
2735 		return "sci";
2736 	case PORT_SCIF:
2737 		return "scif";
2738 	case PORT_SCIFA:
2739 		return "scifa";
2740 	case PORT_SCIFB:
2741 		return "scifb";
2742 	case PORT_HSCIF:
2743 		return "hscif";
2744 	}
2745 
2746 	return NULL;
2747 }
2748 
2749 static int sci_remap_port(struct uart_port *port)
2750 {
2751 	struct sci_port *sport = to_sci_port(port);
2752 
2753 	/*
2754 	 * Nothing to do if there's already an established membase.
2755 	 */
2756 	if (port->membase)
2757 		return 0;
2758 
2759 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2760 		port->membase = ioremap(port->mapbase, sport->reg_size);
2761 		if (unlikely(!port->membase)) {
2762 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2763 			return -ENXIO;
2764 		}
2765 	} else {
2766 		/*
2767 		 * For the simple (and majority of) cases where we don't
2768 		 * need to do any remapping, just cast the cookie
2769 		 * directly.
2770 		 */
2771 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2772 	}
2773 
2774 	return 0;
2775 }
2776 
2777 static void sci_release_port(struct uart_port *port)
2778 {
2779 	struct sci_port *sport = to_sci_port(port);
2780 
2781 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2782 		iounmap(port->membase);
2783 		port->membase = NULL;
2784 	}
2785 
2786 	release_mem_region(port->mapbase, sport->reg_size);
2787 }
2788 
2789 static int sci_request_port(struct uart_port *port)
2790 {
2791 	struct resource *res;
2792 	struct sci_port *sport = to_sci_port(port);
2793 	int ret;
2794 
2795 	res = request_mem_region(port->mapbase, sport->reg_size,
2796 				 dev_name(port->dev));
2797 	if (unlikely(res == NULL)) {
2798 		dev_err(port->dev, "request_mem_region failed.");
2799 		return -EBUSY;
2800 	}
2801 
2802 	ret = sci_remap_port(port);
2803 	if (unlikely(ret != 0)) {
2804 		release_resource(res);
2805 		return ret;
2806 	}
2807 
2808 	return 0;
2809 }
2810 
2811 static void sci_config_port(struct uart_port *port, int flags)
2812 {
2813 	if (flags & UART_CONFIG_TYPE) {
2814 		struct sci_port *sport = to_sci_port(port);
2815 
2816 		port->type = sport->cfg->type;
2817 		sci_request_port(port);
2818 	}
2819 }
2820 
2821 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2822 {
2823 	if (ser->baud_base < 2400)
2824 		/* No paper tape reader for Mitch.. */
2825 		return -EINVAL;
2826 
2827 	return 0;
2828 }
2829 
2830 static const struct uart_ops sci_uart_ops = {
2831 	.tx_empty	= sci_tx_empty,
2832 	.set_mctrl	= sci_set_mctrl,
2833 	.get_mctrl	= sci_get_mctrl,
2834 	.start_tx	= sci_start_tx,
2835 	.stop_tx	= sci_stop_tx,
2836 	.stop_rx	= sci_stop_rx,
2837 	.enable_ms	= sci_enable_ms,
2838 	.break_ctl	= sci_break_ctl,
2839 	.startup	= sci_startup,
2840 	.shutdown	= sci_shutdown,
2841 	.flush_buffer	= sci_flush_buffer,
2842 	.set_termios	= sci_set_termios,
2843 	.pm		= sci_pm,
2844 	.type		= sci_type,
2845 	.release_port	= sci_release_port,
2846 	.request_port	= sci_request_port,
2847 	.config_port	= sci_config_port,
2848 	.verify_port	= sci_verify_port,
2849 #ifdef CONFIG_CONSOLE_POLL
2850 	.poll_get_char	= sci_poll_get_char,
2851 	.poll_put_char	= sci_poll_put_char,
2852 #endif
2853 };
2854 
2855 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2856 {
2857 	const char *clk_names[] = {
2858 		[SCI_FCK] = "fck",
2859 		[SCI_SCK] = "sck",
2860 		[SCI_BRG_INT] = "brg_int",
2861 		[SCI_SCIF_CLK] = "scif_clk",
2862 	};
2863 	struct clk *clk;
2864 	unsigned int i;
2865 
2866 	if (sci_port->cfg->type == PORT_HSCIF)
2867 		clk_names[SCI_SCK] = "hsck";
2868 
2869 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2870 		clk = devm_clk_get_optional(dev, clk_names[i]);
2871 		if (IS_ERR(clk))
2872 			return PTR_ERR(clk);
2873 
2874 		if (!clk && i == SCI_FCK) {
2875 			/*
2876 			 * Not all SH platforms declare a clock lookup entry
2877 			 * for SCI devices, in which case we need to get the
2878 			 * global "peripheral_clk" clock.
2879 			 */
2880 			clk = devm_clk_get(dev, "peripheral_clk");
2881 			if (IS_ERR(clk))
2882 				return dev_err_probe(dev, PTR_ERR(clk),
2883 						     "failed to get %s\n",
2884 						     clk_names[i]);
2885 		}
2886 
2887 		if (!clk)
2888 			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2889 		else
2890 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2891 				clk, clk_get_rate(clk));
2892 		sci_port->clks[i] = clk;
2893 	}
2894 	return 0;
2895 }
2896 
2897 static const struct sci_port_params *
2898 sci_probe_regmap(const struct plat_sci_port *cfg)
2899 {
2900 	unsigned int regtype;
2901 
2902 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2903 		return &sci_port_params[cfg->regtype];
2904 
2905 	switch (cfg->type) {
2906 	case PORT_SCI:
2907 		regtype = SCIx_SCI_REGTYPE;
2908 		break;
2909 	case PORT_IRDA:
2910 		regtype = SCIx_IRDA_REGTYPE;
2911 		break;
2912 	case PORT_SCIFA:
2913 		regtype = SCIx_SCIFA_REGTYPE;
2914 		break;
2915 	case PORT_SCIFB:
2916 		regtype = SCIx_SCIFB_REGTYPE;
2917 		break;
2918 	case PORT_SCIF:
2919 		/*
2920 		 * The SH-4 is a bit of a misnomer here, although that's
2921 		 * where this particular port layout originated. This
2922 		 * configuration (or some slight variation thereof)
2923 		 * remains the dominant model for all SCIFs.
2924 		 */
2925 		regtype = SCIx_SH4_SCIF_REGTYPE;
2926 		break;
2927 	case PORT_HSCIF:
2928 		regtype = SCIx_HSCIF_REGTYPE;
2929 		break;
2930 	default:
2931 		pr_err("Can't probe register map for given port\n");
2932 		return NULL;
2933 	}
2934 
2935 	return &sci_port_params[regtype];
2936 }
2937 
2938 static int sci_init_single(struct platform_device *dev,
2939 			   struct sci_port *sci_port, unsigned int index,
2940 			   const struct plat_sci_port *p, bool early)
2941 {
2942 	struct uart_port *port = &sci_port->port;
2943 	const struct resource *res;
2944 	unsigned int i;
2945 	int ret;
2946 
2947 	sci_port->cfg	= p;
2948 
2949 	port->ops	= &sci_uart_ops;
2950 	port->iotype	= UPIO_MEM;
2951 	port->line	= index;
2952 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2953 
2954 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2955 	if (res == NULL)
2956 		return -ENOMEM;
2957 
2958 	port->mapbase = res->start;
2959 	sci_port->reg_size = resource_size(res);
2960 
2961 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2962 		if (i)
2963 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2964 		else
2965 			sci_port->irqs[i] = platform_get_irq(dev, i);
2966 	}
2967 
2968 	/*
2969 	 * The fourth interrupt on SCI port is transmit end interrupt, so
2970 	 * shuffle the interrupts.
2971 	 */
2972 	if (p->type == PORT_SCI)
2973 		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
2974 
2975 	/* The SCI generates several interrupts. They can be muxed together or
2976 	 * connected to different interrupt lines. In the muxed case only one
2977 	 * interrupt resource is specified as there is only one interrupt ID.
2978 	 * In the non-muxed case, up to 6 interrupt signals might be generated
2979 	 * from the SCI, however those signals might have their own individual
2980 	 * interrupt ID numbers, or muxed together with another interrupt.
2981 	 */
2982 	if (sci_port->irqs[0] < 0)
2983 		return -ENXIO;
2984 
2985 	if (sci_port->irqs[1] < 0)
2986 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2987 			sci_port->irqs[i] = sci_port->irqs[0];
2988 
2989 	sci_port->params = sci_probe_regmap(p);
2990 	if (unlikely(sci_port->params == NULL))
2991 		return -EINVAL;
2992 
2993 	switch (p->type) {
2994 	case PORT_SCIFB:
2995 		sci_port->rx_trigger = 48;
2996 		break;
2997 	case PORT_HSCIF:
2998 		sci_port->rx_trigger = 64;
2999 		break;
3000 	case PORT_SCIFA:
3001 		sci_port->rx_trigger = 32;
3002 		break;
3003 	case PORT_SCIF:
3004 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
3005 			/* RX triggering not implemented for this IP */
3006 			sci_port->rx_trigger = 1;
3007 		else
3008 			sci_port->rx_trigger = 8;
3009 		break;
3010 	default:
3011 		sci_port->rx_trigger = 1;
3012 		break;
3013 	}
3014 
3015 	sci_port->rx_fifo_timeout = 0;
3016 	sci_port->hscif_tot = 0;
3017 
3018 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
3019 	 * match the SoC datasheet, this should be investigated. Let platform
3020 	 * data override the sampling rate for now.
3021 	 */
3022 	sci_port->sampling_rate_mask = p->sampling_rate
3023 				     ? SCI_SR(p->sampling_rate)
3024 				     : sci_port->params->sampling_rate_mask;
3025 
3026 	if (!early) {
3027 		ret = sci_init_clocks(sci_port, &dev->dev);
3028 		if (ret < 0)
3029 			return ret;
3030 
3031 		port->dev = &dev->dev;
3032 
3033 		pm_runtime_enable(&dev->dev);
3034 	}
3035 
3036 	port->type		= p->type;
3037 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
3038 	port->fifosize		= sci_port->params->fifosize;
3039 
3040 	if (port->type == PORT_SCI && !dev->dev.of_node) {
3041 		if (sci_port->reg_size >= 0x20)
3042 			port->regshift = 2;
3043 		else
3044 			port->regshift = 1;
3045 	}
3046 
3047 	/*
3048 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
3049 	 * for the multi-IRQ ports, which is where we are primarily
3050 	 * concerned with the shutdown path synchronization.
3051 	 *
3052 	 * For the muxed case there's nothing more to do.
3053 	 */
3054 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
3055 	port->irqflags		= 0;
3056 
3057 	return 0;
3058 }
3059 
3060 static void sci_cleanup_single(struct sci_port *port)
3061 {
3062 	pm_runtime_disable(port->port.dev);
3063 }
3064 
3065 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3066     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3067 static void serial_console_putchar(struct uart_port *port, unsigned char ch)
3068 {
3069 	sci_poll_put_char(port, ch);
3070 }
3071 
3072 /*
3073  *	Print a string to the serial port trying not to disturb
3074  *	any possible real use of the port...
3075  */
3076 static void serial_console_write(struct console *co, const char *s,
3077 				 unsigned count)
3078 {
3079 	struct sci_port *sci_port = &sci_ports[co->index];
3080 	struct uart_port *port = &sci_port->port;
3081 	unsigned short bits, ctrl, ctrl_temp;
3082 	unsigned long flags;
3083 	int locked = 1;
3084 
3085 	if (port->sysrq)
3086 		locked = 0;
3087 	else if (oops_in_progress)
3088 		locked = uart_port_trylock_irqsave(port, &flags);
3089 	else
3090 		uart_port_lock_irqsave(port, &flags);
3091 
3092 	/* first save SCSCR then disable interrupts, keep clock source */
3093 	ctrl = sci_serial_in(port, SCSCR);
3094 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3095 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3096 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3097 	sci_serial_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3098 
3099 	uart_console_write(port, s, count, serial_console_putchar);
3100 
3101 	/* wait until fifo is empty and last bit has been transmitted */
3102 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3103 	while ((sci_serial_in(port, SCxSR) & bits) != bits)
3104 		cpu_relax();
3105 
3106 	/* restore the SCSCR */
3107 	sci_serial_out(port, SCSCR, ctrl);
3108 
3109 	if (locked)
3110 		uart_port_unlock_irqrestore(port, flags);
3111 }
3112 
3113 static int serial_console_setup(struct console *co, char *options)
3114 {
3115 	struct sci_port *sci_port;
3116 	struct uart_port *port;
3117 	int baud = 115200;
3118 	int bits = 8;
3119 	int parity = 'n';
3120 	int flow = 'n';
3121 	int ret;
3122 
3123 	/*
3124 	 * Refuse to handle any bogus ports.
3125 	 */
3126 	if (co->index < 0 || co->index >= SCI_NPORTS)
3127 		return -ENODEV;
3128 
3129 	sci_port = &sci_ports[co->index];
3130 	port = &sci_port->port;
3131 
3132 	/*
3133 	 * Refuse to handle uninitialized ports.
3134 	 */
3135 	if (!port->ops)
3136 		return -ENODEV;
3137 
3138 	ret = sci_remap_port(port);
3139 	if (unlikely(ret != 0))
3140 		return ret;
3141 
3142 	if (options)
3143 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3144 
3145 	return uart_set_options(port, co, baud, parity, bits, flow);
3146 }
3147 
3148 static struct console serial_console = {
3149 	.name		= "ttySC",
3150 	.device		= uart_console_device,
3151 	.write		= serial_console_write,
3152 	.setup		= serial_console_setup,
3153 	.flags		= CON_PRINTBUFFER,
3154 	.index		= -1,
3155 	.data		= &sci_uart_driver,
3156 };
3157 
3158 #ifdef CONFIG_SUPERH
3159 static char early_serial_buf[32];
3160 
3161 static int early_serial_console_setup(struct console *co, char *options)
3162 {
3163 	/*
3164 	 * This early console is always registered using the earlyprintk=
3165 	 * parameter, which does not call add_preferred_console(). Thus
3166 	 * @options is always NULL and the options for this early console
3167 	 * are passed using a custom buffer.
3168 	 */
3169 	WARN_ON(options);
3170 
3171 	return serial_console_setup(co, early_serial_buf);
3172 }
3173 
3174 static struct console early_serial_console = {
3175 	.name           = "early_ttySC",
3176 	.write          = serial_console_write,
3177 	.setup		= early_serial_console_setup,
3178 	.flags          = CON_PRINTBUFFER,
3179 	.index		= -1,
3180 };
3181 
3182 static int sci_probe_earlyprintk(struct platform_device *pdev)
3183 {
3184 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3185 
3186 	if (early_serial_console.data)
3187 		return -EEXIST;
3188 
3189 	early_serial_console.index = pdev->id;
3190 
3191 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3192 
3193 	if (!strstr(early_serial_buf, "keep"))
3194 		early_serial_console.flags |= CON_BOOT;
3195 
3196 	register_console(&early_serial_console);
3197 	return 0;
3198 }
3199 #endif
3200 
3201 #define SCI_CONSOLE	(&serial_console)
3202 
3203 #else
3204 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3205 {
3206 	return -EINVAL;
3207 }
3208 
3209 #define SCI_CONSOLE	NULL
3210 
3211 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3212 
3213 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3214 
3215 static DEFINE_MUTEX(sci_uart_registration_lock);
3216 static struct uart_driver sci_uart_driver = {
3217 	.owner		= THIS_MODULE,
3218 	.driver_name	= "sci",
3219 	.dev_name	= "ttySC",
3220 	.major		= SCI_MAJOR,
3221 	.minor		= SCI_MINOR_START,
3222 	.nr		= SCI_NPORTS,
3223 	.cons		= SCI_CONSOLE,
3224 };
3225 
3226 static void sci_remove(struct platform_device *dev)
3227 {
3228 	struct sci_port *port = platform_get_drvdata(dev);
3229 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3230 
3231 	sci_ports_in_use &= ~BIT(port->port.line);
3232 	uart_remove_one_port(&sci_uart_driver, &port->port);
3233 
3234 	sci_cleanup_single(port);
3235 
3236 	if (port->port.fifosize > 1)
3237 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3238 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3239 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3240 }
3241 
3242 
3243 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3244 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3245 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3246 
3247 static const struct of_device_id of_sci_match[] __maybe_unused = {
3248 	/* SoC-specific types */
3249 	{
3250 		.compatible = "renesas,scif-r7s72100",
3251 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3252 	},
3253 	{
3254 		.compatible = "renesas,scif-r7s9210",
3255 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3256 	},
3257 	{
3258 		.compatible = "renesas,scif-r9a07g044",
3259 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3260 	},
3261 	{
3262 		.compatible = "renesas,scif-r9a09g057",
3263 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZV2H_SCIF_REGTYPE),
3264 	},
3265 	/* Family-specific types */
3266 	{
3267 		.compatible = "renesas,rcar-gen1-scif",
3268 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3269 	}, {
3270 		.compatible = "renesas,rcar-gen2-scif",
3271 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3272 	}, {
3273 		.compatible = "renesas,rcar-gen3-scif",
3274 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3275 	}, {
3276 		.compatible = "renesas,rcar-gen4-scif",
3277 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3278 	},
3279 	/* Generic types */
3280 	{
3281 		.compatible = "renesas,scif",
3282 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3283 	}, {
3284 		.compatible = "renesas,scifa",
3285 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3286 	}, {
3287 		.compatible = "renesas,scifb",
3288 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3289 	}, {
3290 		.compatible = "renesas,hscif",
3291 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3292 	}, {
3293 		.compatible = "renesas,sci",
3294 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3295 	}, {
3296 		/* Terminator */
3297 	},
3298 };
3299 MODULE_DEVICE_TABLE(of, of_sci_match);
3300 
3301 static void sci_reset_control_assert(void *data)
3302 {
3303 	reset_control_assert(data);
3304 }
3305 
3306 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3307 					  unsigned int *dev_id)
3308 {
3309 	struct device_node *np = pdev->dev.of_node;
3310 	struct reset_control *rstc;
3311 	struct plat_sci_port *p;
3312 	struct sci_port *sp;
3313 	const void *data;
3314 	int id, ret;
3315 
3316 	if (!IS_ENABLED(CONFIG_OF) || !np)
3317 		return ERR_PTR(-EINVAL);
3318 
3319 	data = of_device_get_match_data(&pdev->dev);
3320 
3321 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3322 	if (IS_ERR(rstc))
3323 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3324 					     "failed to get reset ctrl\n"));
3325 
3326 	ret = reset_control_deassert(rstc);
3327 	if (ret) {
3328 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3329 		return ERR_PTR(ret);
3330 	}
3331 
3332 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3333 	if (ret) {
3334 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3335 			ret);
3336 		return ERR_PTR(ret);
3337 	}
3338 
3339 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3340 	if (!p)
3341 		return ERR_PTR(-ENOMEM);
3342 
3343 	/* Get the line number from the aliases node. */
3344 	id = of_alias_get_id(np, "serial");
3345 	if (id < 0 && ~sci_ports_in_use)
3346 		id = ffz(sci_ports_in_use);
3347 	if (id < 0) {
3348 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3349 		return ERR_PTR(-EINVAL);
3350 	}
3351 	if (id >= ARRAY_SIZE(sci_ports)) {
3352 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3353 		return ERR_PTR(-EINVAL);
3354 	}
3355 
3356 	sp = &sci_ports[id];
3357 	*dev_id = id;
3358 
3359 	p->type = SCI_OF_TYPE(data);
3360 	p->regtype = SCI_OF_REGTYPE(data);
3361 
3362 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3363 
3364 	return p;
3365 }
3366 
3367 static int sci_probe_single(struct platform_device *dev,
3368 				      unsigned int index,
3369 				      struct plat_sci_port *p,
3370 				      struct sci_port *sciport)
3371 {
3372 	int ret;
3373 
3374 	/* Sanity check */
3375 	if (unlikely(index >= SCI_NPORTS)) {
3376 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3377 			   index+1, SCI_NPORTS);
3378 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3379 		return -EINVAL;
3380 	}
3381 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3382 	if (sci_ports_in_use & BIT(index))
3383 		return -EBUSY;
3384 
3385 	mutex_lock(&sci_uart_registration_lock);
3386 	if (!sci_uart_driver.state) {
3387 		ret = uart_register_driver(&sci_uart_driver);
3388 		if (ret) {
3389 			mutex_unlock(&sci_uart_registration_lock);
3390 			return ret;
3391 		}
3392 	}
3393 	mutex_unlock(&sci_uart_registration_lock);
3394 
3395 	ret = sci_init_single(dev, sciport, index, p, false);
3396 	if (ret)
3397 		return ret;
3398 
3399 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3400 	if (IS_ERR(sciport->gpios))
3401 		return PTR_ERR(sciport->gpios);
3402 
3403 	if (sciport->has_rtscts) {
3404 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3405 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3406 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3407 			return -EINVAL;
3408 		}
3409 		sciport->port.flags |= UPF_HARD_FLOW;
3410 	}
3411 
3412 	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3413 	if (ret) {
3414 		sci_cleanup_single(sciport);
3415 		return ret;
3416 	}
3417 
3418 	return 0;
3419 }
3420 
3421 static int sci_probe(struct platform_device *dev)
3422 {
3423 	struct plat_sci_port *p;
3424 	struct sci_port *sp;
3425 	unsigned int dev_id;
3426 	int ret;
3427 
3428 	/*
3429 	 * If we've come here via earlyprintk initialization, head off to
3430 	 * the special early probe. We don't have sufficient device state
3431 	 * to make it beyond this yet.
3432 	 */
3433 #ifdef CONFIG_SUPERH
3434 	if (is_sh_early_platform_device(dev))
3435 		return sci_probe_earlyprintk(dev);
3436 #endif
3437 
3438 	if (dev->dev.of_node) {
3439 		p = sci_parse_dt(dev, &dev_id);
3440 		if (IS_ERR(p))
3441 			return PTR_ERR(p);
3442 	} else {
3443 		p = dev->dev.platform_data;
3444 		if (p == NULL) {
3445 			dev_err(&dev->dev, "no platform data supplied\n");
3446 			return -EINVAL;
3447 		}
3448 
3449 		dev_id = dev->id;
3450 	}
3451 
3452 	sp = &sci_ports[dev_id];
3453 	platform_set_drvdata(dev, sp);
3454 
3455 	ret = sci_probe_single(dev, dev_id, p, sp);
3456 	if (ret)
3457 		return ret;
3458 
3459 	if (sp->port.fifosize > 1) {
3460 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3461 		if (ret)
3462 			return ret;
3463 	}
3464 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3465 	    sp->port.type == PORT_HSCIF) {
3466 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3467 		if (ret) {
3468 			if (sp->port.fifosize > 1) {
3469 				device_remove_file(&dev->dev,
3470 						   &dev_attr_rx_fifo_trigger);
3471 			}
3472 			return ret;
3473 		}
3474 	}
3475 
3476 #ifdef CONFIG_SH_STANDARD_BIOS
3477 	sh_bios_gdb_detach();
3478 #endif
3479 
3480 	sci_ports_in_use |= BIT(dev_id);
3481 	return 0;
3482 }
3483 
3484 static __maybe_unused int sci_suspend(struct device *dev)
3485 {
3486 	struct sci_port *sport = dev_get_drvdata(dev);
3487 
3488 	if (sport)
3489 		uart_suspend_port(&sci_uart_driver, &sport->port);
3490 
3491 	return 0;
3492 }
3493 
3494 static __maybe_unused int sci_resume(struct device *dev)
3495 {
3496 	struct sci_port *sport = dev_get_drvdata(dev);
3497 
3498 	if (sport)
3499 		uart_resume_port(&sci_uart_driver, &sport->port);
3500 
3501 	return 0;
3502 }
3503 
3504 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3505 
3506 static struct platform_driver sci_driver = {
3507 	.probe		= sci_probe,
3508 	.remove_new	= sci_remove,
3509 	.driver		= {
3510 		.name	= "sh-sci",
3511 		.pm	= &sci_dev_pm_ops,
3512 		.of_match_table = of_match_ptr(of_sci_match),
3513 	},
3514 };
3515 
3516 static int __init sci_init(void)
3517 {
3518 	pr_info("%s\n", banner);
3519 
3520 	return platform_driver_register(&sci_driver);
3521 }
3522 
3523 static void __exit sci_exit(void)
3524 {
3525 	platform_driver_unregister(&sci_driver);
3526 
3527 	if (sci_uart_driver.state)
3528 		uart_unregister_driver(&sci_uart_driver);
3529 }
3530 
3531 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3532 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3533 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3534 #endif
3535 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3536 static struct plat_sci_port port_cfg __initdata;
3537 
3538 static int __init early_console_setup(struct earlycon_device *device,
3539 				      int type)
3540 {
3541 	if (!device->port.membase)
3542 		return -ENODEV;
3543 
3544 	device->port.type = type;
3545 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3546 	port_cfg.type = type;
3547 	sci_ports[0].cfg = &port_cfg;
3548 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3549 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3550 	sci_serial_out(&sci_ports[0].port, SCSCR,
3551 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3552 
3553 	device->con->write = serial_console_write;
3554 	return 0;
3555 }
3556 static int __init sci_early_console_setup(struct earlycon_device *device,
3557 					  const char *opt)
3558 {
3559 	return early_console_setup(device, PORT_SCI);
3560 }
3561 static int __init scif_early_console_setup(struct earlycon_device *device,
3562 					  const char *opt)
3563 {
3564 	return early_console_setup(device, PORT_SCIF);
3565 }
3566 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3567 					  const char *opt)
3568 {
3569 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3570 	return early_console_setup(device, PORT_SCIF);
3571 }
3572 
3573 static int __init rzv2hscif_early_console_setup(struct earlycon_device *device,
3574 						const char *opt)
3575 {
3576 	port_cfg.regtype = SCIx_RZV2H_SCIF_REGTYPE;
3577 	return early_console_setup(device, PORT_SCIF);
3578 }
3579 
3580 static int __init scifa_early_console_setup(struct earlycon_device *device,
3581 					  const char *opt)
3582 {
3583 	return early_console_setup(device, PORT_SCIFA);
3584 }
3585 static int __init scifb_early_console_setup(struct earlycon_device *device,
3586 					  const char *opt)
3587 {
3588 	return early_console_setup(device, PORT_SCIFB);
3589 }
3590 static int __init hscif_early_console_setup(struct earlycon_device *device,
3591 					  const char *opt)
3592 {
3593 	return early_console_setup(device, PORT_HSCIF);
3594 }
3595 
3596 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3597 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3598 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3599 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3600 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a09g057", rzv2hscif_early_console_setup);
3601 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3602 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3603 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3604 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3605 
3606 module_init(sci_init);
3607 module_exit(sci_exit);
3608 
3609 MODULE_LICENSE("GPL");
3610 MODULE_ALIAS("platform:sh-sci");
3611 MODULE_AUTHOR("Paul Mundt");
3612 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3613