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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_suspend_regs {
108 	u16 scdl;
109 	u16 sccks;
110 	u16 scsmr;
111 	u16 scscr;
112 	u16 scfcr;
113 	u16 scsptr;
114 	u16 hssrr;
115 	u16 scpcr;
116 	u16 scpdr;
117 	u8 scbrr;
118 	u8 semr;
119 };
120 
121 struct sci_port_params {
122 	const struct plat_sci_reg regs[SCIx_NR_REGS];
123 	unsigned int fifosize;
124 	unsigned int overrun_reg;
125 	unsigned int overrun_mask;
126 	unsigned int sampling_rate_mask;
127 	unsigned int error_mask;
128 	unsigned int error_clear;
129 };
130 
131 struct sci_port {
132 	struct uart_port	port;
133 
134 	/* Platform configuration */
135 	const struct sci_port_params *params;
136 	const struct plat_sci_port *cfg;
137 	unsigned int		sampling_rate_mask;
138 	resource_size_t		reg_size;
139 	struct mctrl_gpios	*gpios;
140 
141 	/* Clocks */
142 	struct clk		*clks[SCI_NUM_CLKS];
143 	unsigned long		clk_rates[SCI_NUM_CLKS];
144 
145 	int			irqs[SCIx_NR_IRQS];
146 	char			*irqstr[SCIx_NR_IRQS];
147 
148 	struct dma_chan			*chan_tx;
149 	struct dma_chan			*chan_rx;
150 
151 	struct reset_control		*rstc;
152 
153 #ifdef CONFIG_SERIAL_SH_SCI_DMA
154 	struct dma_chan			*chan_tx_saved;
155 	struct dma_chan			*chan_rx_saved;
156 	dma_cookie_t			cookie_tx;
157 	dma_cookie_t			cookie_rx[2];
158 	dma_cookie_t			active_rx;
159 	dma_addr_t			tx_dma_addr;
160 	unsigned int			tx_dma_len;
161 	struct scatterlist		sg_rx[2];
162 	void				*rx_buf[2];
163 	size_t				buf_len_rx;
164 	struct work_struct		work_tx;
165 	struct hrtimer			rx_timer;
166 	unsigned int			rx_timeout;	/* microseconds */
167 #endif
168 	unsigned int			rx_frame;
169 	int				rx_trigger;
170 	struct timer_list		rx_fifo_timer;
171 	int				rx_fifo_timeout;
172 	struct sci_suspend_regs		suspend_regs;
173 	u16				hscif_tot;
174 
175 	bool has_rtscts;
176 	bool autorts;
177 	bool tx_occurred;
178 };
179 
180 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
181 
182 static struct sci_port sci_ports[SCI_NPORTS];
183 static unsigned long sci_ports_in_use;
184 static struct uart_driver sci_uart_driver;
185 static bool sci_uart_earlycon;
186 static bool sci_uart_earlycon_dev_probing;
187 
188 static inline struct sci_port *
to_sci_port(struct uart_port * uart)189 to_sci_port(struct uart_port *uart)
190 {
191 	return container_of(uart, struct sci_port, port);
192 }
193 
194 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
195 	/*
196 	 * Common SCI definitions, dependent on the port's regshift
197 	 * value.
198 	 */
199 	[SCIx_SCI_REGTYPE] = {
200 		.regs = {
201 			[SCSMR]		= { 0x00,  8 },
202 			[SCBRR]		= { 0x01,  8 },
203 			[SCSCR]		= { 0x02,  8 },
204 			[SCxTDR]	= { 0x03,  8 },
205 			[SCxSR]		= { 0x04,  8 },
206 			[SCxRDR]	= { 0x05,  8 },
207 		},
208 		.fifosize = 1,
209 		.overrun_reg = SCxSR,
210 		.overrun_mask = SCI_ORER,
211 		.sampling_rate_mask = SCI_SR(32),
212 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
213 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
214 	},
215 
216 	/*
217 	 * Common definitions for legacy IrDA ports.
218 	 */
219 	[SCIx_IRDA_REGTYPE] = {
220 		.regs = {
221 			[SCSMR]		= { 0x00,  8 },
222 			[SCBRR]		= { 0x02,  8 },
223 			[SCSCR]		= { 0x04,  8 },
224 			[SCxTDR]	= { 0x06,  8 },
225 			[SCxSR]		= { 0x08, 16 },
226 			[SCxRDR]	= { 0x0a,  8 },
227 			[SCFCR]		= { 0x0c,  8 },
228 			[SCFDR]		= { 0x0e, 16 },
229 		},
230 		.fifosize = 1,
231 		.overrun_reg = SCxSR,
232 		.overrun_mask = SCI_ORER,
233 		.sampling_rate_mask = SCI_SR(32),
234 		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
235 		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
236 	},
237 
238 	/*
239 	 * Common SCIFA definitions.
240 	 */
241 	[SCIx_SCIFA_REGTYPE] = {
242 		.regs = {
243 			[SCSMR]		= { 0x00, 16 },
244 			[SCBRR]		= { 0x04,  8 },
245 			[SCSCR]		= { 0x08, 16 },
246 			[SCxTDR]	= { 0x20,  8 },
247 			[SCxSR]		= { 0x14, 16 },
248 			[SCxRDR]	= { 0x24,  8 },
249 			[SCFCR]		= { 0x18, 16 },
250 			[SCFDR]		= { 0x1c, 16 },
251 			[SCPCR]		= { 0x30, 16 },
252 			[SCPDR]		= { 0x34, 16 },
253 		},
254 		.fifosize = 64,
255 		.overrun_reg = SCxSR,
256 		.overrun_mask = SCIFA_ORER,
257 		.sampling_rate_mask = SCI_SR_SCIFAB,
258 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
259 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
260 	},
261 
262 	/*
263 	 * Common SCIFB definitions.
264 	 */
265 	[SCIx_SCIFB_REGTYPE] = {
266 		.regs = {
267 			[SCSMR]		= { 0x00, 16 },
268 			[SCBRR]		= { 0x04,  8 },
269 			[SCSCR]		= { 0x08, 16 },
270 			[SCxTDR]	= { 0x40,  8 },
271 			[SCxSR]		= { 0x14, 16 },
272 			[SCxRDR]	= { 0x60,  8 },
273 			[SCFCR]		= { 0x18, 16 },
274 			[SCTFDR]	= { 0x38, 16 },
275 			[SCRFDR]	= { 0x3c, 16 },
276 			[SCPCR]		= { 0x30, 16 },
277 			[SCPDR]		= { 0x34, 16 },
278 		},
279 		.fifosize = 256,
280 		.overrun_reg = SCxSR,
281 		.overrun_mask = SCIFA_ORER,
282 		.sampling_rate_mask = SCI_SR_SCIFAB,
283 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
284 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
285 	},
286 
287 	/*
288 	 * Common SH-2(A) SCIF definitions for ports with FIFO data
289 	 * count registers.
290 	 */
291 	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
292 		.regs = {
293 			[SCSMR]		= { 0x00, 16 },
294 			[SCBRR]		= { 0x04,  8 },
295 			[SCSCR]		= { 0x08, 16 },
296 			[SCxTDR]	= { 0x0c,  8 },
297 			[SCxSR]		= { 0x10, 16 },
298 			[SCxRDR]	= { 0x14,  8 },
299 			[SCFCR]		= { 0x18, 16 },
300 			[SCFDR]		= { 0x1c, 16 },
301 			[SCSPTR]	= { 0x20, 16 },
302 			[SCLSR]		= { 0x24, 16 },
303 		},
304 		.fifosize = 16,
305 		.overrun_reg = SCLSR,
306 		.overrun_mask = SCLSR_ORER,
307 		.sampling_rate_mask = SCI_SR(32),
308 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
309 		.error_clear = SCIF_ERROR_CLEAR,
310 	},
311 
312 	/*
313 	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
314 	 * It looks like a normal SCIF with FIFO data, but with a
315 	 * compressed address space. Also, the break out of interrupts
316 	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
317 	 */
318 	[SCIx_RZ_SCIFA_REGTYPE] = {
319 		.regs = {
320 			[SCSMR]		= { 0x00, 16 },
321 			[SCBRR]		= { 0x02,  8 },
322 			[SCSCR]		= { 0x04, 16 },
323 			[SCxTDR]	= { 0x06,  8 },
324 			[SCxSR]		= { 0x08, 16 },
325 			[SCxRDR]	= { 0x0A,  8 },
326 			[SCFCR]		= { 0x0C, 16 },
327 			[SCFDR]		= { 0x0E, 16 },
328 			[SCSPTR]	= { 0x10, 16 },
329 			[SCLSR]		= { 0x12, 16 },
330 			[SEMR]		= { 0x14, 8 },
331 		},
332 		.fifosize = 16,
333 		.overrun_reg = SCLSR,
334 		.overrun_mask = SCLSR_ORER,
335 		.sampling_rate_mask = SCI_SR(32),
336 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
337 		.error_clear = SCIF_ERROR_CLEAR,
338 	},
339 
340 	/*
341 	 * The "SCIF" that is in RZ/V2H(P) SoC is similar to one found on RZ/G2L SoC
342 	 * with below differences,
343 	 * - Break out of interrupts are different: ERI, BRI, RXI, TXI, TEI, DRI,
344 	 *   TEI-DRI, RXI-EDGE and TXI-EDGE.
345 	 * - SCSMR register does not have CM bit (BIT(7)) ie it does not support synchronous mode.
346 	 * - SCFCR register does not have SCFCR_MCE bit.
347 	 * - SCSPTR register has only bits SCSPTR_SPB2DT and SCSPTR_SPB2IO.
348 	 */
349 	[SCIx_RZV2H_SCIF_REGTYPE] = {
350 		.regs = {
351 			[SCSMR]		= { 0x00, 16 },
352 			[SCBRR]		= { 0x02,  8 },
353 			[SCSCR]		= { 0x04, 16 },
354 			[SCxTDR]	= { 0x06,  8 },
355 			[SCxSR]		= { 0x08, 16 },
356 			[SCxRDR]	= { 0x0a,  8 },
357 			[SCFCR]		= { 0x0c, 16 },
358 			[SCFDR]		= { 0x0e, 16 },
359 			[SCSPTR]	= { 0x10, 16 },
360 			[SCLSR]		= { 0x12, 16 },
361 			[SEMR]		= { 0x14, 8 },
362 		},
363 		.fifosize = 16,
364 		.overrun_reg = SCLSR,
365 		.overrun_mask = SCLSR_ORER,
366 		.sampling_rate_mask = SCI_SR(32),
367 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
368 		.error_clear = SCIF_ERROR_CLEAR,
369 	},
370 
371 	/*
372 	 * Common SH-3 SCIF definitions.
373 	 */
374 	[SCIx_SH3_SCIF_REGTYPE] = {
375 		.regs = {
376 			[SCSMR]		= { 0x00,  8 },
377 			[SCBRR]		= { 0x02,  8 },
378 			[SCSCR]		= { 0x04,  8 },
379 			[SCxTDR]	= { 0x06,  8 },
380 			[SCxSR]		= { 0x08, 16 },
381 			[SCxRDR]	= { 0x0a,  8 },
382 			[SCFCR]		= { 0x0c,  8 },
383 			[SCFDR]		= { 0x0e, 16 },
384 		},
385 		.fifosize = 16,
386 		.overrun_reg = SCLSR,
387 		.overrun_mask = SCLSR_ORER,
388 		.sampling_rate_mask = SCI_SR(32),
389 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
390 		.error_clear = SCIF_ERROR_CLEAR,
391 	},
392 
393 	/*
394 	 * Common SH-4(A) SCIF(B) definitions.
395 	 */
396 	[SCIx_SH4_SCIF_REGTYPE] = {
397 		.regs = {
398 			[SCSMR]		= { 0x00, 16 },
399 			[SCBRR]		= { 0x04,  8 },
400 			[SCSCR]		= { 0x08, 16 },
401 			[SCxTDR]	= { 0x0c,  8 },
402 			[SCxSR]		= { 0x10, 16 },
403 			[SCxRDR]	= { 0x14,  8 },
404 			[SCFCR]		= { 0x18, 16 },
405 			[SCFDR]		= { 0x1c, 16 },
406 			[SCSPTR]	= { 0x20, 16 },
407 			[SCLSR]		= { 0x24, 16 },
408 		},
409 		.fifosize = 16,
410 		.overrun_reg = SCLSR,
411 		.overrun_mask = SCLSR_ORER,
412 		.sampling_rate_mask = SCI_SR(32),
413 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
414 		.error_clear = SCIF_ERROR_CLEAR,
415 	},
416 
417 	/*
418 	 * Common SCIF definitions for ports with a Baud Rate Generator for
419 	 * External Clock (BRG).
420 	 */
421 	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
422 		.regs = {
423 			[SCSMR]		= { 0x00, 16 },
424 			[SCBRR]		= { 0x04,  8 },
425 			[SCSCR]		= { 0x08, 16 },
426 			[SCxTDR]	= { 0x0c,  8 },
427 			[SCxSR]		= { 0x10, 16 },
428 			[SCxRDR]	= { 0x14,  8 },
429 			[SCFCR]		= { 0x18, 16 },
430 			[SCFDR]		= { 0x1c, 16 },
431 			[SCSPTR]	= { 0x20, 16 },
432 			[SCLSR]		= { 0x24, 16 },
433 			[SCDL]		= { 0x30, 16 },
434 			[SCCKS]		= { 0x34, 16 },
435 		},
436 		.fifosize = 16,
437 		.overrun_reg = SCLSR,
438 		.overrun_mask = SCLSR_ORER,
439 		.sampling_rate_mask = SCI_SR(32),
440 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
441 		.error_clear = SCIF_ERROR_CLEAR,
442 	},
443 
444 	/*
445 	 * Common HSCIF definitions.
446 	 */
447 	[SCIx_HSCIF_REGTYPE] = {
448 		.regs = {
449 			[SCSMR]		= { 0x00, 16 },
450 			[SCBRR]		= { 0x04,  8 },
451 			[SCSCR]		= { 0x08, 16 },
452 			[SCxTDR]	= { 0x0c,  8 },
453 			[SCxSR]		= { 0x10, 16 },
454 			[SCxRDR]	= { 0x14,  8 },
455 			[SCFCR]		= { 0x18, 16 },
456 			[SCFDR]		= { 0x1c, 16 },
457 			[SCSPTR]	= { 0x20, 16 },
458 			[SCLSR]		= { 0x24, 16 },
459 			[HSSRR]		= { 0x40, 16 },
460 			[SCDL]		= { 0x30, 16 },
461 			[SCCKS]		= { 0x34, 16 },
462 			[HSRTRGR]	= { 0x54, 16 },
463 			[HSTTRGR]	= { 0x58, 16 },
464 		},
465 		.fifosize = 128,
466 		.overrun_reg = SCLSR,
467 		.overrun_mask = SCLSR_ORER,
468 		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
469 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
470 		.error_clear = SCIF_ERROR_CLEAR,
471 	},
472 
473 	/*
474 	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
475 	 * register.
476 	 */
477 	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
478 		.regs = {
479 			[SCSMR]		= { 0x00, 16 },
480 			[SCBRR]		= { 0x04,  8 },
481 			[SCSCR]		= { 0x08, 16 },
482 			[SCxTDR]	= { 0x0c,  8 },
483 			[SCxSR]		= { 0x10, 16 },
484 			[SCxRDR]	= { 0x14,  8 },
485 			[SCFCR]		= { 0x18, 16 },
486 			[SCFDR]		= { 0x1c, 16 },
487 			[SCLSR]		= { 0x24, 16 },
488 		},
489 		.fifosize = 16,
490 		.overrun_reg = SCLSR,
491 		.overrun_mask = SCLSR_ORER,
492 		.sampling_rate_mask = SCI_SR(32),
493 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
494 		.error_clear = SCIF_ERROR_CLEAR,
495 	},
496 
497 	/*
498 	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
499 	 * count registers.
500 	 */
501 	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
502 		.regs = {
503 			[SCSMR]		= { 0x00, 16 },
504 			[SCBRR]		= { 0x04,  8 },
505 			[SCSCR]		= { 0x08, 16 },
506 			[SCxTDR]	= { 0x0c,  8 },
507 			[SCxSR]		= { 0x10, 16 },
508 			[SCxRDR]	= { 0x14,  8 },
509 			[SCFCR]		= { 0x18, 16 },
510 			[SCFDR]		= { 0x1c, 16 },
511 			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
512 			[SCRFDR]	= { 0x20, 16 },
513 			[SCSPTR]	= { 0x24, 16 },
514 			[SCLSR]		= { 0x28, 16 },
515 		},
516 		.fifosize = 16,
517 		.overrun_reg = SCLSR,
518 		.overrun_mask = SCLSR_ORER,
519 		.sampling_rate_mask = SCI_SR(32),
520 		.error_mask = SCIF_DEFAULT_ERROR_MASK,
521 		.error_clear = SCIF_ERROR_CLEAR,
522 	},
523 
524 	/*
525 	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
526 	 * registers.
527 	 */
528 	[SCIx_SH7705_SCIF_REGTYPE] = {
529 		.regs = {
530 			[SCSMR]		= { 0x00, 16 },
531 			[SCBRR]		= { 0x04,  8 },
532 			[SCSCR]		= { 0x08, 16 },
533 			[SCxTDR]	= { 0x20,  8 },
534 			[SCxSR]		= { 0x14, 16 },
535 			[SCxRDR]	= { 0x24,  8 },
536 			[SCFCR]		= { 0x18, 16 },
537 			[SCFDR]		= { 0x1c, 16 },
538 		},
539 		.fifosize = 64,
540 		.overrun_reg = SCxSR,
541 		.overrun_mask = SCIFA_ORER,
542 		.sampling_rate_mask = SCI_SR(16),
543 		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
544 		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
545 	},
546 };
547 
548 #define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
549 
550 /*
551  * The "offset" here is rather misleading, in that it refers to an enum
552  * value relative to the port mapping rather than the fixed offset
553  * itself, which needs to be manually retrieved from the platform's
554  * register map for the given port.
555  */
sci_serial_in(struct uart_port * p,int offset)556 static unsigned int sci_serial_in(struct uart_port *p, int offset)
557 {
558 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
559 
560 	if (reg->size == 8)
561 		return ioread8(p->membase + (reg->offset << p->regshift));
562 	else if (reg->size == 16)
563 		return ioread16(p->membase + (reg->offset << p->regshift));
564 	else
565 		WARN(1, "Invalid register access\n");
566 
567 	return 0;
568 }
569 
sci_serial_out(struct uart_port * p,int offset,int value)570 static void sci_serial_out(struct uart_port *p, int offset, int value)
571 {
572 	const struct plat_sci_reg *reg = sci_getreg(p, offset);
573 
574 	if (reg->size == 8)
575 		iowrite8(value, p->membase + (reg->offset << p->regshift));
576 	else if (reg->size == 16)
577 		iowrite16(value, p->membase + (reg->offset << p->regshift));
578 	else
579 		WARN(1, "Invalid register access\n");
580 }
581 
sci_port_enable(struct sci_port * sci_port)582 static void sci_port_enable(struct sci_port *sci_port)
583 {
584 	unsigned int i;
585 
586 	if (!sci_port->port.dev)
587 		return;
588 
589 	pm_runtime_get_sync(sci_port->port.dev);
590 
591 	for (i = 0; i < SCI_NUM_CLKS; i++) {
592 		clk_prepare_enable(sci_port->clks[i]);
593 		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
594 	}
595 	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
596 }
597 
sci_port_disable(struct sci_port * sci_port)598 static void sci_port_disable(struct sci_port *sci_port)
599 {
600 	unsigned int i;
601 
602 	if (!sci_port->port.dev)
603 		return;
604 
605 	for (i = SCI_NUM_CLKS; i-- > 0; )
606 		clk_disable_unprepare(sci_port->clks[i]);
607 
608 	pm_runtime_put_sync(sci_port->port.dev);
609 }
610 
port_rx_irq_mask(struct uart_port * port)611 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
612 {
613 	/*
614 	 * Not all ports (such as SCIFA) will support REIE. Rather than
615 	 * special-casing the port type, we check the port initialization
616 	 * IRQ enable mask to see whether the IRQ is desired at all. If
617 	 * it's unset, it's logically inferred that there's no point in
618 	 * testing for it.
619 	 */
620 	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
621 }
622 
sci_start_tx(struct uart_port * port)623 static void sci_start_tx(struct uart_port *port)
624 {
625 	struct sci_port *s = to_sci_port(port);
626 	unsigned short ctrl;
627 
628 #ifdef CONFIG_SERIAL_SH_SCI_DMA
629 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
630 		u16 new, scr = sci_serial_in(port, SCSCR);
631 		if (s->chan_tx)
632 			new = scr | SCSCR_TDRQE;
633 		else
634 			new = scr & ~SCSCR_TDRQE;
635 		if (new != scr)
636 			sci_serial_out(port, SCSCR, new);
637 	}
638 
639 	if (s->chan_tx && !kfifo_is_empty(&port->state->port.xmit_fifo) &&
640 	    dma_submit_error(s->cookie_tx)) {
641 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
642 			/* Switch irq from SCIF to DMA */
643 			disable_irq_nosync(s->irqs[SCIx_TXI_IRQ]);
644 
645 		s->cookie_tx = 0;
646 		schedule_work(&s->work_tx);
647 	}
648 #endif
649 
650 	if (!s->chan_tx || s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE ||
651 	    port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
652 		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
653 		ctrl = sci_serial_in(port, SCSCR);
654 
655 		/*
656 		 * For SCI, TE (transmit enable) must be set after setting TIE
657 		 * (transmit interrupt enable) or in the same instruction to start
658 		 * the transmit process.
659 		 */
660 		if (port->type == PORT_SCI)
661 			ctrl |= SCSCR_TE;
662 
663 		sci_serial_out(port, SCSCR, ctrl | SCSCR_TIE);
664 	}
665 }
666 
sci_stop_tx(struct uart_port * port)667 static void sci_stop_tx(struct uart_port *port)
668 {
669 	unsigned short ctrl;
670 
671 	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
672 	ctrl = sci_serial_in(port, SCSCR);
673 
674 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
675 		ctrl &= ~SCSCR_TDRQE;
676 
677 	ctrl &= ~SCSCR_TIE;
678 
679 	sci_serial_out(port, SCSCR, ctrl);
680 
681 #ifdef CONFIG_SERIAL_SH_SCI_DMA
682 	if (to_sci_port(port)->chan_tx &&
683 	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
684 		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
685 		to_sci_port(port)->cookie_tx = -EINVAL;
686 	}
687 #endif
688 }
689 
sci_start_rx(struct uart_port * port)690 static void sci_start_rx(struct uart_port *port)
691 {
692 	unsigned short ctrl;
693 
694 	ctrl = sci_serial_in(port, SCSCR) | port_rx_irq_mask(port);
695 
696 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
697 		ctrl &= ~SCSCR_RDRQE;
698 
699 	sci_serial_out(port, SCSCR, ctrl);
700 }
701 
sci_stop_rx(struct uart_port * port)702 static void sci_stop_rx(struct uart_port *port)
703 {
704 	unsigned short ctrl;
705 
706 	ctrl = sci_serial_in(port, SCSCR);
707 
708 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
709 		ctrl &= ~SCSCR_RDRQE;
710 
711 	ctrl &= ~port_rx_irq_mask(port);
712 
713 	sci_serial_out(port, SCSCR, ctrl);
714 }
715 
sci_clear_SCxSR(struct uart_port * port,unsigned int mask)716 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
717 {
718 	if (port->type == PORT_SCI) {
719 		/* Just store the mask */
720 		sci_serial_out(port, SCxSR, mask);
721 	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
722 		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
723 		/* Only clear the status bits we want to clear */
724 		sci_serial_out(port, SCxSR, sci_serial_in(port, SCxSR) & mask);
725 	} else {
726 		/* Store the mask, clear parity/framing errors */
727 		sci_serial_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
728 	}
729 }
730 
731 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
732     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
733 
734 #ifdef CONFIG_CONSOLE_POLL
sci_poll_get_char(struct uart_port * port)735 static int sci_poll_get_char(struct uart_port *port)
736 {
737 	unsigned short status;
738 	int c;
739 
740 	do {
741 		status = sci_serial_in(port, SCxSR);
742 		if (status & SCxSR_ERRORS(port)) {
743 			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
744 			continue;
745 		}
746 		break;
747 	} while (1);
748 
749 	if (!(status & SCxSR_RDxF(port)))
750 		return NO_POLL_CHAR;
751 
752 	c = sci_serial_in(port, SCxRDR);
753 
754 	/* Dummy read */
755 	sci_serial_in(port, SCxSR);
756 	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
757 
758 	return c;
759 }
760 #endif
761 
sci_poll_put_char(struct uart_port * port,unsigned char c)762 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
763 {
764 	unsigned short status;
765 
766 	do {
767 		status = sci_serial_in(port, SCxSR);
768 	} while (!(status & SCxSR_TDxE(port)));
769 
770 	sci_serial_out(port, SCxTDR, c);
771 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
772 }
773 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
774 	  CONFIG_SERIAL_SH_SCI_EARLYCON */
775 
sci_init_pins(struct uart_port * port,unsigned int cflag)776 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
777 {
778 	struct sci_port *s = to_sci_port(port);
779 
780 	/*
781 	 * Use port-specific handler if provided.
782 	 */
783 	if (s->cfg->ops && s->cfg->ops->init_pins) {
784 		s->cfg->ops->init_pins(port, cflag);
785 		return;
786 	}
787 
788 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
789 		u16 data = sci_serial_in(port, SCPDR);
790 		u16 ctrl = sci_serial_in(port, SCPCR);
791 
792 		/* Enable RXD and TXD pin functions */
793 		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
794 		if (to_sci_port(port)->has_rtscts) {
795 			/* RTS# is output, active low, unless autorts */
796 			if (!(port->mctrl & TIOCM_RTS)) {
797 				ctrl |= SCPCR_RTSC;
798 				data |= SCPDR_RTSD;
799 			} else if (!s->autorts) {
800 				ctrl |= SCPCR_RTSC;
801 				data &= ~SCPDR_RTSD;
802 			} else {
803 				/* Enable RTS# pin function */
804 				ctrl &= ~SCPCR_RTSC;
805 			}
806 			/* Enable CTS# pin function */
807 			ctrl &= ~SCPCR_CTSC;
808 		}
809 		sci_serial_out(port, SCPDR, data);
810 		sci_serial_out(port, SCPCR, ctrl);
811 	} else if (sci_getreg(port, SCSPTR)->size && s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE) {
812 		u16 status = sci_serial_in(port, SCSPTR);
813 
814 		/* RTS# is always output; and active low, unless autorts */
815 		status |= SCSPTR_RTSIO;
816 		if (!(port->mctrl & TIOCM_RTS))
817 			status |= SCSPTR_RTSDT;
818 		else if (!s->autorts)
819 			status &= ~SCSPTR_RTSDT;
820 		/* CTS# and SCK are inputs */
821 		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
822 		sci_serial_out(port, SCSPTR, status);
823 	}
824 }
825 
sci_txfill(struct uart_port * port)826 static int sci_txfill(struct uart_port *port)
827 {
828 	struct sci_port *s = to_sci_port(port);
829 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
830 	const struct plat_sci_reg *reg;
831 
832 	reg = sci_getreg(port, SCTFDR);
833 	if (reg->size)
834 		return sci_serial_in(port, SCTFDR) & fifo_mask;
835 
836 	reg = sci_getreg(port, SCFDR);
837 	if (reg->size)
838 		return sci_serial_in(port, SCFDR) >> 8;
839 
840 	return !(sci_serial_in(port, SCxSR) & SCI_TDRE);
841 }
842 
sci_txroom(struct uart_port * port)843 static int sci_txroom(struct uart_port *port)
844 {
845 	return port->fifosize - sci_txfill(port);
846 }
847 
sci_rxfill(struct uart_port * port)848 static int sci_rxfill(struct uart_port *port)
849 {
850 	struct sci_port *s = to_sci_port(port);
851 	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
852 	const struct plat_sci_reg *reg;
853 
854 	reg = sci_getreg(port, SCRFDR);
855 	if (reg->size)
856 		return sci_serial_in(port, SCRFDR) & fifo_mask;
857 
858 	reg = sci_getreg(port, SCFDR);
859 	if (reg->size)
860 		return sci_serial_in(port, SCFDR) & fifo_mask;
861 
862 	return (sci_serial_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
863 }
864 
865 /* ********************************************************************** *
866  *                   the interrupt related routines                       *
867  * ********************************************************************** */
868 
sci_transmit_chars(struct uart_port * port)869 static void sci_transmit_chars(struct uart_port *port)
870 {
871 	struct tty_port *tport = &port->state->port;
872 	unsigned int stopped = uart_tx_stopped(port);
873 	struct sci_port *s = to_sci_port(port);
874 	unsigned short status;
875 	unsigned short ctrl;
876 	int count;
877 
878 	status = sci_serial_in(port, SCxSR);
879 	if (!(status & SCxSR_TDxE(port))) {
880 		ctrl = sci_serial_in(port, SCSCR);
881 		if (kfifo_is_empty(&tport->xmit_fifo))
882 			ctrl &= ~SCSCR_TIE;
883 		else
884 			ctrl |= SCSCR_TIE;
885 		sci_serial_out(port, SCSCR, ctrl);
886 		return;
887 	}
888 
889 	count = sci_txroom(port);
890 
891 	do {
892 		unsigned char c;
893 
894 		if (port->x_char) {
895 			c = port->x_char;
896 			port->x_char = 0;
897 		} else if (stopped || !kfifo_get(&tport->xmit_fifo, &c)) {
898 			if (port->type == PORT_SCI &&
899 				   kfifo_is_empty(&tport->xmit_fifo)) {
900 				ctrl = sci_serial_in(port, SCSCR);
901 				ctrl &= ~SCSCR_TE;
902 				sci_serial_out(port, SCSCR, ctrl);
903 				return;
904 			}
905 			break;
906 		}
907 
908 		sci_serial_out(port, SCxTDR, c);
909 		s->tx_occurred = true;
910 
911 		port->icount.tx++;
912 	} while (--count > 0);
913 
914 	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
915 
916 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
917 		uart_write_wakeup(port);
918 	if (kfifo_is_empty(&tport->xmit_fifo)) {
919 		if (port->type == PORT_SCI) {
920 			ctrl = sci_serial_in(port, SCSCR);
921 			ctrl &= ~SCSCR_TIE;
922 			ctrl |= SCSCR_TEIE;
923 			sci_serial_out(port, SCSCR, ctrl);
924 		}
925 
926 		sci_stop_tx(port);
927 	}
928 }
929 
sci_receive_chars(struct uart_port * port)930 static void sci_receive_chars(struct uart_port *port)
931 {
932 	struct tty_port *tport = &port->state->port;
933 	int i, count, copied = 0;
934 	unsigned short status;
935 	unsigned char flag;
936 
937 	status = sci_serial_in(port, SCxSR);
938 	if (!(status & SCxSR_RDxF(port)))
939 		return;
940 
941 	while (1) {
942 		/* Don't copy more bytes than there is room for in the buffer */
943 		count = tty_buffer_request_room(tport, sci_rxfill(port));
944 
945 		/* If for any reason we can't copy more data, we're done! */
946 		if (count == 0)
947 			break;
948 
949 		if (port->type == PORT_SCI) {
950 			char c = sci_serial_in(port, SCxRDR);
951 			if (uart_handle_sysrq_char(port, c))
952 				count = 0;
953 			else
954 				tty_insert_flip_char(tport, c, TTY_NORMAL);
955 		} else {
956 			for (i = 0; i < count; i++) {
957 				char c;
958 
959 				if (port->type == PORT_SCIF ||
960 				    port->type == PORT_HSCIF) {
961 					status = sci_serial_in(port, SCxSR);
962 					c = sci_serial_in(port, SCxRDR);
963 				} else {
964 					c = sci_serial_in(port, SCxRDR);
965 					status = sci_serial_in(port, SCxSR);
966 				}
967 				if (uart_handle_sysrq_char(port, c)) {
968 					count--; i--;
969 					continue;
970 				}
971 
972 				/* Store data and status */
973 				if (status & SCxSR_FER(port)) {
974 					flag = TTY_FRAME;
975 					port->icount.frame++;
976 				} else if (status & SCxSR_PER(port)) {
977 					flag = TTY_PARITY;
978 					port->icount.parity++;
979 				} else
980 					flag = TTY_NORMAL;
981 
982 				tty_insert_flip_char(tport, c, flag);
983 			}
984 		}
985 
986 		sci_serial_in(port, SCxSR); /* dummy read */
987 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
988 
989 		copied += count;
990 		port->icount.rx += count;
991 	}
992 
993 	if (copied) {
994 		/* Tell the rest of the system the news. New characters! */
995 		tty_flip_buffer_push(tport);
996 	} else {
997 		/* TTY buffers full; read from RX reg to prevent lockup */
998 		sci_serial_in(port, SCxRDR);
999 		sci_serial_in(port, SCxSR); /* dummy read */
1000 		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1001 	}
1002 }
1003 
sci_handle_errors(struct uart_port * port)1004 static int sci_handle_errors(struct uart_port *port)
1005 {
1006 	int copied = 0;
1007 	unsigned short status = sci_serial_in(port, SCxSR);
1008 	struct tty_port *tport = &port->state->port;
1009 	struct sci_port *s = to_sci_port(port);
1010 
1011 	/* Handle overruns */
1012 	if (status & s->params->overrun_mask) {
1013 		port->icount.overrun++;
1014 
1015 		/* overrun error */
1016 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
1017 			copied++;
1018 	}
1019 
1020 	if (status & SCxSR_FER(port)) {
1021 		/* frame error */
1022 		port->icount.frame++;
1023 
1024 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
1025 			copied++;
1026 	}
1027 
1028 	if (status & SCxSR_PER(port)) {
1029 		/* parity error */
1030 		port->icount.parity++;
1031 
1032 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
1033 			copied++;
1034 	}
1035 
1036 	if (copied)
1037 		tty_flip_buffer_push(tport);
1038 
1039 	return copied;
1040 }
1041 
sci_handle_fifo_overrun(struct uart_port * port)1042 static int sci_handle_fifo_overrun(struct uart_port *port)
1043 {
1044 	struct tty_port *tport = &port->state->port;
1045 	struct sci_port *s = to_sci_port(port);
1046 	const struct plat_sci_reg *reg;
1047 	int copied = 0;
1048 	u16 status;
1049 
1050 	reg = sci_getreg(port, s->params->overrun_reg);
1051 	if (!reg->size)
1052 		return 0;
1053 
1054 	status = sci_serial_in(port, s->params->overrun_reg);
1055 	if (status & s->params->overrun_mask) {
1056 		status &= ~s->params->overrun_mask;
1057 		sci_serial_out(port, s->params->overrun_reg, status);
1058 
1059 		port->icount.overrun++;
1060 
1061 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1062 		tty_flip_buffer_push(tport);
1063 		copied++;
1064 	}
1065 
1066 	return copied;
1067 }
1068 
sci_handle_breaks(struct uart_port * port)1069 static int sci_handle_breaks(struct uart_port *port)
1070 {
1071 	int copied = 0;
1072 	unsigned short status = sci_serial_in(port, SCxSR);
1073 	struct tty_port *tport = &port->state->port;
1074 
1075 	if (uart_handle_break(port))
1076 		return 0;
1077 
1078 	if (status & SCxSR_BRK(port)) {
1079 		port->icount.brk++;
1080 
1081 		/* Notify of BREAK */
1082 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1083 			copied++;
1084 	}
1085 
1086 	if (copied)
1087 		tty_flip_buffer_push(tport);
1088 
1089 	copied += sci_handle_fifo_overrun(port);
1090 
1091 	return copied;
1092 }
1093 
scif_set_rtrg(struct uart_port * port,int rx_trig)1094 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1095 {
1096 	unsigned int bits;
1097 
1098 	if (rx_trig >= port->fifosize)
1099 		rx_trig = port->fifosize - 1;
1100 	if (rx_trig < 1)
1101 		rx_trig = 1;
1102 
1103 	/* HSCIF can be set to an arbitrary level. */
1104 	if (sci_getreg(port, HSRTRGR)->size) {
1105 		sci_serial_out(port, HSRTRGR, rx_trig);
1106 		return rx_trig;
1107 	}
1108 
1109 	switch (port->type) {
1110 	case PORT_SCIF:
1111 		if (rx_trig < 4) {
1112 			bits = 0;
1113 			rx_trig = 1;
1114 		} else if (rx_trig < 8) {
1115 			bits = SCFCR_RTRG0;
1116 			rx_trig = 4;
1117 		} else if (rx_trig < 14) {
1118 			bits = SCFCR_RTRG1;
1119 			rx_trig = 8;
1120 		} else {
1121 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1122 			rx_trig = 14;
1123 		}
1124 		break;
1125 	case PORT_SCIFA:
1126 	case PORT_SCIFB:
1127 		if (rx_trig < 16) {
1128 			bits = 0;
1129 			rx_trig = 1;
1130 		} else if (rx_trig < 32) {
1131 			bits = SCFCR_RTRG0;
1132 			rx_trig = 16;
1133 		} else if (rx_trig < 48) {
1134 			bits = SCFCR_RTRG1;
1135 			rx_trig = 32;
1136 		} else {
1137 			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1138 			rx_trig = 48;
1139 		}
1140 		break;
1141 	default:
1142 		WARN(1, "unknown FIFO configuration");
1143 		return 1;
1144 	}
1145 
1146 	sci_serial_out(port, SCFCR,
1147 		       (sci_serial_in(port, SCFCR) &
1148 			~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1149 
1150 	return rx_trig;
1151 }
1152 
scif_rtrg_enabled(struct uart_port * port)1153 static int scif_rtrg_enabled(struct uart_port *port)
1154 {
1155 	if (sci_getreg(port, HSRTRGR)->size)
1156 		return sci_serial_in(port, HSRTRGR) != 0;
1157 	else
1158 		return (sci_serial_in(port, SCFCR) &
1159 			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1160 }
1161 
rx_fifo_timer_fn(struct timer_list * t)1162 static void rx_fifo_timer_fn(struct timer_list *t)
1163 {
1164 	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1165 	struct uart_port *port = &s->port;
1166 
1167 	dev_dbg(port->dev, "Rx timed out\n");
1168 	scif_set_rtrg(port, 1);
1169 }
1170 
rx_fifo_trigger_show(struct device * dev,struct device_attribute * attr,char * buf)1171 static ssize_t rx_fifo_trigger_show(struct device *dev,
1172 				    struct device_attribute *attr, char *buf)
1173 {
1174 	struct uart_port *port = dev_get_drvdata(dev);
1175 	struct sci_port *sci = to_sci_port(port);
1176 
1177 	return sprintf(buf, "%d\n", sci->rx_trigger);
1178 }
1179 
rx_fifo_trigger_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1180 static ssize_t rx_fifo_trigger_store(struct device *dev,
1181 				     struct device_attribute *attr,
1182 				     const char *buf, size_t count)
1183 {
1184 	struct uart_port *port = dev_get_drvdata(dev);
1185 	struct sci_port *sci = to_sci_port(port);
1186 	int ret;
1187 	long r;
1188 
1189 	ret = kstrtol(buf, 0, &r);
1190 	if (ret)
1191 		return ret;
1192 
1193 	sci->rx_trigger = scif_set_rtrg(port, r);
1194 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1195 		scif_set_rtrg(port, 1);
1196 
1197 	return count;
1198 }
1199 
1200 static DEVICE_ATTR_RW(rx_fifo_trigger);
1201 
rx_fifo_timeout_show(struct device * dev,struct device_attribute * attr,char * buf)1202 static ssize_t rx_fifo_timeout_show(struct device *dev,
1203 			       struct device_attribute *attr,
1204 			       char *buf)
1205 {
1206 	struct uart_port *port = dev_get_drvdata(dev);
1207 	struct sci_port *sci = to_sci_port(port);
1208 	int v;
1209 
1210 	if (port->type == PORT_HSCIF)
1211 		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1212 	else
1213 		v = sci->rx_fifo_timeout;
1214 
1215 	return sprintf(buf, "%d\n", v);
1216 }
1217 
rx_fifo_timeout_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1218 static ssize_t rx_fifo_timeout_store(struct device *dev,
1219 				struct device_attribute *attr,
1220 				const char *buf,
1221 				size_t count)
1222 {
1223 	struct uart_port *port = dev_get_drvdata(dev);
1224 	struct sci_port *sci = to_sci_port(port);
1225 	int ret;
1226 	long r;
1227 
1228 	ret = kstrtol(buf, 0, &r);
1229 	if (ret)
1230 		return ret;
1231 
1232 	if (port->type == PORT_HSCIF) {
1233 		if (r < 0 || r > 3)
1234 			return -EINVAL;
1235 		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1236 	} else {
1237 		sci->rx_fifo_timeout = r;
1238 		scif_set_rtrg(port, 1);
1239 		if (r > 0)
1240 			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1241 	}
1242 
1243 	return count;
1244 }
1245 
1246 static DEVICE_ATTR_RW(rx_fifo_timeout);
1247 
1248 
1249 #ifdef CONFIG_SERIAL_SH_SCI_DMA
sci_dma_tx_complete(void * arg)1250 static void sci_dma_tx_complete(void *arg)
1251 {
1252 	struct sci_port *s = arg;
1253 	struct uart_port *port = &s->port;
1254 	struct tty_port *tport = &port->state->port;
1255 	unsigned long flags;
1256 
1257 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1258 
1259 	uart_port_lock_irqsave(port, &flags);
1260 
1261 	uart_xmit_advance(port, s->tx_dma_len);
1262 
1263 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
1264 		uart_write_wakeup(port);
1265 
1266 	s->tx_occurred = true;
1267 
1268 	if (!kfifo_is_empty(&tport->xmit_fifo)) {
1269 		s->cookie_tx = 0;
1270 		schedule_work(&s->work_tx);
1271 	} else {
1272 		s->cookie_tx = -EINVAL;
1273 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1274 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1275 			u16 ctrl = sci_serial_in(port, SCSCR);
1276 			sci_serial_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1277 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1278 				/* Switch irq from DMA to SCIF */
1279 				dmaengine_pause(s->chan_tx_saved);
1280 				enable_irq(s->irqs[SCIx_TXI_IRQ]);
1281 			}
1282 		}
1283 	}
1284 
1285 	uart_port_unlock_irqrestore(port, flags);
1286 }
1287 
1288 /* Locking: called with port lock held */
sci_dma_rx_push(struct sci_port * s,void * buf,size_t count)1289 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1290 {
1291 	struct uart_port *port = &s->port;
1292 	struct tty_port *tport = &port->state->port;
1293 	int copied;
1294 
1295 	copied = tty_insert_flip_string(tport, buf, count);
1296 	if (copied < count)
1297 		port->icount.buf_overrun++;
1298 
1299 	port->icount.rx += copied;
1300 
1301 	return copied;
1302 }
1303 
sci_dma_rx_find_active(struct sci_port * s)1304 static int sci_dma_rx_find_active(struct sci_port *s)
1305 {
1306 	unsigned int i;
1307 
1308 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1309 		if (s->active_rx == s->cookie_rx[i])
1310 			return i;
1311 
1312 	return -1;
1313 }
1314 
1315 /* Must only be called with uart_port_lock taken */
sci_dma_rx_chan_invalidate(struct sci_port * s)1316 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1317 {
1318 	unsigned int i;
1319 
1320 	s->chan_rx = NULL;
1321 	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1322 		s->cookie_rx[i] = -EINVAL;
1323 	s->active_rx = 0;
1324 }
1325 
sci_dma_rx_release(struct sci_port * s)1326 static void sci_dma_rx_release(struct sci_port *s)
1327 {
1328 	struct dma_chan *chan = s->chan_rx_saved;
1329 	struct uart_port *port = &s->port;
1330 	unsigned long flags;
1331 
1332 	uart_port_lock_irqsave(port, &flags);
1333 	s->chan_rx_saved = NULL;
1334 	sci_dma_rx_chan_invalidate(s);
1335 	uart_port_unlock_irqrestore(port, flags);
1336 
1337 	dmaengine_terminate_sync(chan);
1338 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1339 			  sg_dma_address(&s->sg_rx[0]));
1340 	dma_release_channel(chan);
1341 }
1342 
start_hrtimer_us(struct hrtimer * hrt,unsigned long usec)1343 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1344 {
1345 	long sec = usec / 1000000;
1346 	long nsec = (usec % 1000000) * 1000;
1347 	ktime_t t = ktime_set(sec, nsec);
1348 
1349 	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1350 }
1351 
sci_dma_rx_reenable_irq(struct sci_port * s)1352 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1353 {
1354 	struct uart_port *port = &s->port;
1355 	u16 scr;
1356 
1357 	/* Direct new serial port interrupts back to CPU */
1358 	scr = sci_serial_in(port, SCSCR);
1359 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1360 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1361 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1362 		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1363 			scif_set_rtrg(port, s->rx_trigger);
1364 		else
1365 			scr &= ~SCSCR_RDRQE;
1366 	}
1367 	sci_serial_out(port, SCSCR, scr | SCSCR_RIE);
1368 }
1369 
sci_dma_rx_complete(void * arg)1370 static void sci_dma_rx_complete(void *arg)
1371 {
1372 	struct sci_port *s = arg;
1373 	struct dma_chan *chan = s->chan_rx;
1374 	struct uart_port *port = &s->port;
1375 	struct dma_async_tx_descriptor *desc;
1376 	unsigned long flags;
1377 	int active, count = 0;
1378 
1379 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1380 		s->active_rx);
1381 
1382 	hrtimer_cancel(&s->rx_timer);
1383 
1384 	uart_port_lock_irqsave(port, &flags);
1385 
1386 	active = sci_dma_rx_find_active(s);
1387 	if (active >= 0)
1388 		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1389 
1390 	if (count)
1391 		tty_flip_buffer_push(&port->state->port);
1392 
1393 	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1394 				       DMA_DEV_TO_MEM,
1395 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1396 	if (!desc)
1397 		goto fail;
1398 
1399 	desc->callback = sci_dma_rx_complete;
1400 	desc->callback_param = s;
1401 	s->cookie_rx[active] = dmaengine_submit(desc);
1402 	if (dma_submit_error(s->cookie_rx[active]))
1403 		goto fail;
1404 
1405 	s->active_rx = s->cookie_rx[!active];
1406 
1407 	dma_async_issue_pending(chan);
1408 
1409 	uart_port_unlock_irqrestore(port, flags);
1410 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1411 		__func__, s->cookie_rx[active], active, s->active_rx);
1412 
1413 	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1414 
1415 	return;
1416 
1417 fail:
1418 	/* Switch to PIO */
1419 	dmaengine_terminate_async(chan);
1420 	sci_dma_rx_chan_invalidate(s);
1421 	sci_dma_rx_reenable_irq(s);
1422 	uart_port_unlock_irqrestore(port, flags);
1423 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1424 }
1425 
sci_dma_tx_release(struct sci_port * s)1426 static void sci_dma_tx_release(struct sci_port *s)
1427 {
1428 	struct dma_chan *chan = s->chan_tx_saved;
1429 
1430 	cancel_work_sync(&s->work_tx);
1431 	s->chan_tx_saved = s->chan_tx = NULL;
1432 	s->cookie_tx = -EINVAL;
1433 	dmaengine_terminate_sync(chan);
1434 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1435 			 DMA_TO_DEVICE);
1436 	dma_release_channel(chan);
1437 }
1438 
sci_dma_rx_submit(struct sci_port * s,bool port_lock_held)1439 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1440 {
1441 	struct dma_chan *chan = s->chan_rx;
1442 	struct uart_port *port = &s->port;
1443 	unsigned long flags;
1444 	int i;
1445 
1446 	for (i = 0; i < 2; i++) {
1447 		struct scatterlist *sg = &s->sg_rx[i];
1448 		struct dma_async_tx_descriptor *desc;
1449 
1450 		desc = dmaengine_prep_slave_sg(chan,
1451 			sg, 1, DMA_DEV_TO_MEM,
1452 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1453 		if (!desc)
1454 			goto fail;
1455 
1456 		desc->callback = sci_dma_rx_complete;
1457 		desc->callback_param = s;
1458 		s->cookie_rx[i] = dmaengine_submit(desc);
1459 		if (dma_submit_error(s->cookie_rx[i]))
1460 			goto fail;
1461 
1462 	}
1463 
1464 	s->active_rx = s->cookie_rx[0];
1465 
1466 	dma_async_issue_pending(chan);
1467 	return 0;
1468 
1469 fail:
1470 	/* Switch to PIO */
1471 	if (!port_lock_held)
1472 		uart_port_lock_irqsave(port, &flags);
1473 	if (i)
1474 		dmaengine_terminate_async(chan);
1475 	sci_dma_rx_chan_invalidate(s);
1476 	sci_start_rx(port);
1477 	if (!port_lock_held)
1478 		uart_port_unlock_irqrestore(port, flags);
1479 	return -EAGAIN;
1480 }
1481 
sci_dma_tx_work_fn(struct work_struct * work)1482 static void sci_dma_tx_work_fn(struct work_struct *work)
1483 {
1484 	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1485 	struct dma_async_tx_descriptor *desc;
1486 	struct dma_chan *chan = s->chan_tx;
1487 	struct uart_port *port = &s->port;
1488 	struct tty_port *tport = &port->state->port;
1489 	unsigned long flags;
1490 	unsigned int tail;
1491 	dma_addr_t buf;
1492 
1493 	/*
1494 	 * DMA is idle now.
1495 	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1496 	 * offsets and lengths. Since it is a circular buffer, we have to
1497 	 * transmit till the end, and then the rest. Take the port lock to get a
1498 	 * consistent xmit buffer state.
1499 	 */
1500 	uart_port_lock_irq(port);
1501 	s->tx_dma_len = kfifo_out_linear(&tport->xmit_fifo, &tail,
1502 			UART_XMIT_SIZE);
1503 	buf = s->tx_dma_addr + tail;
1504 	if (!s->tx_dma_len) {
1505 		/* Transmit buffer has been flushed */
1506 		uart_port_unlock_irq(port);
1507 		return;
1508 	}
1509 
1510 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1511 					   DMA_MEM_TO_DEV,
1512 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1513 	if (!desc) {
1514 		uart_port_unlock_irq(port);
1515 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1516 		goto switch_to_pio;
1517 	}
1518 
1519 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1520 				   DMA_TO_DEVICE);
1521 
1522 	desc->callback = sci_dma_tx_complete;
1523 	desc->callback_param = s;
1524 	s->cookie_tx = dmaengine_submit(desc);
1525 	if (dma_submit_error(s->cookie_tx)) {
1526 		uart_port_unlock_irq(port);
1527 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1528 		goto switch_to_pio;
1529 	}
1530 
1531 	uart_port_unlock_irq(port);
1532 	dev_dbg(port->dev, "%s: %p: %u, cookie %d\n",
1533 		__func__, tport->xmit_buf, tail, s->cookie_tx);
1534 
1535 	dma_async_issue_pending(chan);
1536 	return;
1537 
1538 switch_to_pio:
1539 	uart_port_lock_irqsave(port, &flags);
1540 	s->chan_tx = NULL;
1541 	sci_start_tx(port);
1542 	uart_port_unlock_irqrestore(port, flags);
1543 	return;
1544 }
1545 
sci_dma_rx_timer_fn(struct hrtimer * t)1546 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1547 {
1548 	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1549 	struct dma_chan *chan = s->chan_rx;
1550 	struct uart_port *port = &s->port;
1551 	struct dma_tx_state state;
1552 	enum dma_status status;
1553 	unsigned long flags;
1554 	unsigned int read;
1555 	int active, count;
1556 
1557 	dev_dbg(port->dev, "DMA Rx timed out\n");
1558 
1559 	uart_port_lock_irqsave(port, &flags);
1560 
1561 	active = sci_dma_rx_find_active(s);
1562 	if (active < 0) {
1563 		uart_port_unlock_irqrestore(port, flags);
1564 		return HRTIMER_NORESTART;
1565 	}
1566 
1567 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1568 	if (status == DMA_COMPLETE) {
1569 		uart_port_unlock_irqrestore(port, flags);
1570 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1571 			s->active_rx, active);
1572 
1573 		/* Let packet complete handler take care of the packet */
1574 		return HRTIMER_NORESTART;
1575 	}
1576 
1577 	dmaengine_pause(chan);
1578 
1579 	/*
1580 	 * sometimes DMA transfer doesn't stop even if it is stopped and
1581 	 * data keeps on coming until transaction is complete so check
1582 	 * for DMA_COMPLETE again
1583 	 * Let packet complete handler take care of the packet
1584 	 */
1585 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1586 	if (status == DMA_COMPLETE) {
1587 		uart_port_unlock_irqrestore(port, flags);
1588 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1589 		return HRTIMER_NORESTART;
1590 	}
1591 
1592 	/* Handle incomplete DMA receive */
1593 	dmaengine_terminate_async(s->chan_rx);
1594 	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1595 
1596 	if (read) {
1597 		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1598 		if (count)
1599 			tty_flip_buffer_push(&port->state->port);
1600 	}
1601 
1602 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1603 	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1604 		sci_dma_rx_submit(s, true);
1605 
1606 	sci_dma_rx_reenable_irq(s);
1607 
1608 	uart_port_unlock_irqrestore(port, flags);
1609 
1610 	return HRTIMER_NORESTART;
1611 }
1612 
sci_request_dma_chan(struct uart_port * port,enum dma_transfer_direction dir)1613 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1614 					     enum dma_transfer_direction dir)
1615 {
1616 	struct dma_chan *chan;
1617 	struct dma_slave_config cfg;
1618 	int ret;
1619 
1620 	chan = dma_request_chan(port->dev, dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1621 	if (IS_ERR(chan)) {
1622 		dev_dbg(port->dev, "dma_request_chan failed\n");
1623 		return NULL;
1624 	}
1625 
1626 	memset(&cfg, 0, sizeof(cfg));
1627 	cfg.direction = dir;
1628 	cfg.dst_addr = port->mapbase +
1629 		(sci_getreg(port, SCxTDR)->offset << port->regshift);
1630 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1631 	cfg.src_addr = port->mapbase +
1632 		(sci_getreg(port, SCxRDR)->offset << port->regshift);
1633 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1634 
1635 	ret = dmaengine_slave_config(chan, &cfg);
1636 	if (ret) {
1637 		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1638 		dma_release_channel(chan);
1639 		return NULL;
1640 	}
1641 
1642 	return chan;
1643 }
1644 
sci_request_dma(struct uart_port * port)1645 static void sci_request_dma(struct uart_port *port)
1646 {
1647 	struct sci_port *s = to_sci_port(port);
1648 	struct tty_port *tport = &port->state->port;
1649 	struct dma_chan *chan;
1650 
1651 	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1652 
1653 	/*
1654 	 * DMA on console may interfere with Kernel log messages which use
1655 	 * plain putchar(). So, simply don't use it with a console.
1656 	 */
1657 	if (uart_console(port))
1658 		return;
1659 
1660 	if (!port->dev->of_node)
1661 		return;
1662 
1663 	s->cookie_tx = -EINVAL;
1664 
1665 	/*
1666 	 * Don't request a dma channel if no channel was specified
1667 	 * in the device tree.
1668 	 */
1669 	if (!of_property_present(port->dev->of_node, "dmas"))
1670 		return;
1671 
1672 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1673 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1674 	if (chan) {
1675 		/* UART circular tx buffer is an aligned page. */
1676 		s->tx_dma_addr = dma_map_single(chan->device->dev,
1677 						tport->xmit_buf,
1678 						UART_XMIT_SIZE,
1679 						DMA_TO_DEVICE);
1680 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1681 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1682 			dma_release_channel(chan);
1683 		} else {
1684 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1685 				__func__, UART_XMIT_SIZE,
1686 				tport->xmit_buf, &s->tx_dma_addr);
1687 
1688 			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1689 			s->chan_tx_saved = s->chan_tx = chan;
1690 		}
1691 	}
1692 
1693 	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1694 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1695 	if (chan) {
1696 		unsigned int i;
1697 		dma_addr_t dma;
1698 		void *buf;
1699 
1700 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1701 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1702 					 &dma, GFP_KERNEL);
1703 		if (!buf) {
1704 			dev_warn(port->dev,
1705 				 "Failed to allocate Rx dma buffer, using PIO\n");
1706 			dma_release_channel(chan);
1707 			return;
1708 		}
1709 
1710 		for (i = 0; i < 2; i++) {
1711 			struct scatterlist *sg = &s->sg_rx[i];
1712 
1713 			sg_init_table(sg, 1);
1714 			s->rx_buf[i] = buf;
1715 			sg_dma_address(sg) = dma;
1716 			sg_dma_len(sg) = s->buf_len_rx;
1717 
1718 			buf += s->buf_len_rx;
1719 			dma += s->buf_len_rx;
1720 		}
1721 
1722 		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1723 		s->rx_timer.function = sci_dma_rx_timer_fn;
1724 
1725 		s->chan_rx_saved = s->chan_rx = chan;
1726 
1727 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1728 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1729 			sci_dma_rx_submit(s, false);
1730 	}
1731 }
1732 
sci_free_dma(struct uart_port * port)1733 static void sci_free_dma(struct uart_port *port)
1734 {
1735 	struct sci_port *s = to_sci_port(port);
1736 
1737 	if (s->chan_tx_saved)
1738 		sci_dma_tx_release(s);
1739 	if (s->chan_rx_saved)
1740 		sci_dma_rx_release(s);
1741 }
1742 
sci_flush_buffer(struct uart_port * port)1743 static void sci_flush_buffer(struct uart_port *port)
1744 {
1745 	struct sci_port *s = to_sci_port(port);
1746 
1747 	/*
1748 	 * In uart_flush_buffer(), the xmit circular buffer has just been
1749 	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1750 	 * pending transfers
1751 	 */
1752 	s->tx_dma_len = 0;
1753 	if (s->chan_tx) {
1754 		dmaengine_terminate_async(s->chan_tx);
1755 		s->cookie_tx = -EINVAL;
1756 	}
1757 }
1758 
sci_dma_check_tx_occurred(struct sci_port * s)1759 static void sci_dma_check_tx_occurred(struct sci_port *s)
1760 {
1761 	struct dma_tx_state state;
1762 	enum dma_status status;
1763 
1764 	if (!s->chan_tx)
1765 		return;
1766 
1767 	status = dmaengine_tx_status(s->chan_tx, s->cookie_tx, &state);
1768 	if (status == DMA_COMPLETE || status == DMA_IN_PROGRESS)
1769 		s->tx_occurred = true;
1770 }
1771 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
sci_request_dma(struct uart_port * port)1772 static inline void sci_request_dma(struct uart_port *port)
1773 {
1774 }
1775 
sci_free_dma(struct uart_port * port)1776 static inline void sci_free_dma(struct uart_port *port)
1777 {
1778 }
1779 
sci_dma_check_tx_occurred(struct sci_port * s)1780 static void sci_dma_check_tx_occurred(struct sci_port *s)
1781 {
1782 }
1783 
1784 #define sci_flush_buffer	NULL
1785 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1786 
sci_rx_interrupt(int irq,void * ptr)1787 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1788 {
1789 	struct uart_port *port = ptr;
1790 	struct sci_port *s = to_sci_port(port);
1791 
1792 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1793 	if (s->chan_rx) {
1794 		u16 scr = sci_serial_in(port, SCSCR);
1795 		u16 ssr = sci_serial_in(port, SCxSR);
1796 
1797 		/* Disable future Rx interrupts */
1798 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1799 		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1800 			disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
1801 			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1802 				scif_set_rtrg(port, 1);
1803 				scr |= SCSCR_RIE;
1804 			} else {
1805 				scr |= SCSCR_RDRQE;
1806 			}
1807 		} else {
1808 			if (sci_dma_rx_submit(s, false) < 0)
1809 				goto handle_pio;
1810 
1811 			scr &= ~SCSCR_RIE;
1812 		}
1813 		sci_serial_out(port, SCSCR, scr);
1814 		/* Clear current interrupt */
1815 		sci_serial_out(port, SCxSR,
1816 			       ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1817 		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1818 			jiffies, s->rx_timeout);
1819 		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1820 
1821 		return IRQ_HANDLED;
1822 	}
1823 
1824 handle_pio:
1825 #endif
1826 
1827 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1828 		if (!scif_rtrg_enabled(port))
1829 			scif_set_rtrg(port, s->rx_trigger);
1830 
1831 		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1832 			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1833 	}
1834 
1835 	/* I think sci_receive_chars has to be called irrespective
1836 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1837 	 * to be disabled?
1838 	 */
1839 	sci_receive_chars(port);
1840 
1841 	return IRQ_HANDLED;
1842 }
1843 
sci_tx_interrupt(int irq,void * ptr)1844 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1845 {
1846 	struct uart_port *port = ptr;
1847 	unsigned long flags;
1848 
1849 	uart_port_lock_irqsave(port, &flags);
1850 	sci_transmit_chars(port);
1851 	uart_port_unlock_irqrestore(port, flags);
1852 
1853 	return IRQ_HANDLED;
1854 }
1855 
sci_tx_end_interrupt(int irq,void * ptr)1856 static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
1857 {
1858 	struct uart_port *port = ptr;
1859 	unsigned long flags;
1860 	unsigned short ctrl;
1861 
1862 	if (port->type != PORT_SCI)
1863 		return sci_tx_interrupt(irq, ptr);
1864 
1865 	uart_port_lock_irqsave(port, &flags);
1866 	ctrl = sci_serial_in(port, SCSCR);
1867 	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
1868 	sci_serial_out(port, SCSCR, ctrl);
1869 	uart_port_unlock_irqrestore(port, flags);
1870 
1871 	return IRQ_HANDLED;
1872 }
1873 
sci_br_interrupt(int irq,void * ptr)1874 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1875 {
1876 	struct uart_port *port = ptr;
1877 
1878 	/* Handle BREAKs */
1879 	sci_handle_breaks(port);
1880 
1881 	/* drop invalid character received before break was detected */
1882 	sci_serial_in(port, SCxRDR);
1883 
1884 	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1885 
1886 	return IRQ_HANDLED;
1887 }
1888 
sci_er_interrupt(int irq,void * ptr)1889 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1890 {
1891 	struct uart_port *port = ptr;
1892 	struct sci_port *s = to_sci_port(port);
1893 
1894 	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1895 		/* Break and Error interrupts are muxed */
1896 		unsigned short ssr_status = sci_serial_in(port, SCxSR);
1897 
1898 		/* Break Interrupt */
1899 		if (ssr_status & SCxSR_BRK(port))
1900 			sci_br_interrupt(irq, ptr);
1901 
1902 		/* Break only? */
1903 		if (!(ssr_status & SCxSR_ERRORS(port)))
1904 			return IRQ_HANDLED;
1905 	}
1906 
1907 	/* Handle errors */
1908 	if (port->type == PORT_SCI) {
1909 		if (sci_handle_errors(port)) {
1910 			/* discard character in rx buffer */
1911 			sci_serial_in(port, SCxSR);
1912 			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1913 		}
1914 	} else {
1915 		sci_handle_fifo_overrun(port);
1916 		if (!s->chan_rx)
1917 			sci_receive_chars(port);
1918 	}
1919 
1920 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1921 
1922 	/* Kick the transmission */
1923 	if (!s->chan_tx)
1924 		sci_tx_interrupt(irq, ptr);
1925 
1926 	return IRQ_HANDLED;
1927 }
1928 
sci_mpxed_interrupt(int irq,void * ptr)1929 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1930 {
1931 	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1932 	struct uart_port *port = ptr;
1933 	struct sci_port *s = to_sci_port(port);
1934 	irqreturn_t ret = IRQ_NONE;
1935 
1936 	ssr_status = sci_serial_in(port, SCxSR);
1937 	scr_status = sci_serial_in(port, SCSCR);
1938 	if (s->params->overrun_reg == SCxSR)
1939 		orer_status = ssr_status;
1940 	else if (sci_getreg(port, s->params->overrun_reg)->size)
1941 		orer_status = sci_serial_in(port, s->params->overrun_reg);
1942 
1943 	err_enabled = scr_status & port_rx_irq_mask(port);
1944 
1945 	/* Tx Interrupt */
1946 	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1947 	    !s->chan_tx)
1948 		ret = sci_tx_interrupt(irq, ptr);
1949 
1950 	/*
1951 	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1952 	 * DR flags
1953 	 */
1954 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1955 	    (scr_status & SCSCR_RIE))
1956 		ret = sci_rx_interrupt(irq, ptr);
1957 
1958 	/* Error Interrupt */
1959 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1960 		ret = sci_er_interrupt(irq, ptr);
1961 
1962 	/* Break Interrupt */
1963 	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1964 	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1965 		ret = sci_br_interrupt(irq, ptr);
1966 
1967 	/* Overrun Interrupt */
1968 	if (orer_status & s->params->overrun_mask) {
1969 		sci_handle_fifo_overrun(port);
1970 		ret = IRQ_HANDLED;
1971 	}
1972 
1973 	return ret;
1974 }
1975 
1976 static const struct sci_irq_desc {
1977 	const char	*desc;
1978 	irq_handler_t	handler;
1979 } sci_irq_desc[] = {
1980 	/*
1981 	 * Split out handlers, the default case.
1982 	 */
1983 	[SCIx_ERI_IRQ] = {
1984 		.desc = "rx err",
1985 		.handler = sci_er_interrupt,
1986 	},
1987 
1988 	[SCIx_RXI_IRQ] = {
1989 		.desc = "rx full",
1990 		.handler = sci_rx_interrupt,
1991 	},
1992 
1993 	[SCIx_TXI_IRQ] = {
1994 		.desc = "tx empty",
1995 		.handler = sci_tx_interrupt,
1996 	},
1997 
1998 	[SCIx_BRI_IRQ] = {
1999 		.desc = "break",
2000 		.handler = sci_br_interrupt,
2001 	},
2002 
2003 	[SCIx_DRI_IRQ] = {
2004 		.desc = "rx ready",
2005 		.handler = sci_rx_interrupt,
2006 	},
2007 
2008 	[SCIx_TEI_IRQ] = {
2009 		.desc = "tx end",
2010 		.handler = sci_tx_end_interrupt,
2011 	},
2012 
2013 	/*
2014 	 * Special muxed handler.
2015 	 */
2016 	[SCIx_MUX_IRQ] = {
2017 		.desc = "mux",
2018 		.handler = sci_mpxed_interrupt,
2019 	},
2020 };
2021 
sci_request_irq(struct sci_port * port)2022 static int sci_request_irq(struct sci_port *port)
2023 {
2024 	struct uart_port *up = &port->port;
2025 	int i, j, w, ret = 0;
2026 
2027 	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
2028 		const struct sci_irq_desc *desc;
2029 		int irq;
2030 
2031 		/* Check if already registered (muxed) */
2032 		for (w = 0; w < i; w++)
2033 			if (port->irqs[w] == port->irqs[i])
2034 				w = i + 1;
2035 		if (w > i)
2036 			continue;
2037 
2038 		if (SCIx_IRQ_IS_MUXED(port)) {
2039 			i = SCIx_MUX_IRQ;
2040 			irq = up->irq;
2041 		} else {
2042 			irq = port->irqs[i];
2043 
2044 			/*
2045 			 * Certain port types won't support all of the
2046 			 * available interrupt sources.
2047 			 */
2048 			if (unlikely(irq < 0))
2049 				continue;
2050 		}
2051 
2052 		desc = sci_irq_desc + i;
2053 		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
2054 					    dev_name(up->dev), desc->desc);
2055 		if (!port->irqstr[j]) {
2056 			ret = -ENOMEM;
2057 			goto out_nomem;
2058 		}
2059 
2060 		ret = request_irq(irq, desc->handler, up->irqflags,
2061 				  port->irqstr[j], port);
2062 		if (unlikely(ret)) {
2063 			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
2064 			goto out_noirq;
2065 		}
2066 	}
2067 
2068 	return 0;
2069 
2070 out_noirq:
2071 	while (--i >= 0)
2072 		free_irq(port->irqs[i], port);
2073 
2074 out_nomem:
2075 	while (--j >= 0)
2076 		kfree(port->irqstr[j]);
2077 
2078 	return ret;
2079 }
2080 
sci_free_irq(struct sci_port * port)2081 static void sci_free_irq(struct sci_port *port)
2082 {
2083 	int i, j;
2084 
2085 	/*
2086 	 * Intentionally in reverse order so we iterate over the muxed
2087 	 * IRQ first.
2088 	 */
2089 	for (i = 0; i < SCIx_NR_IRQS; i++) {
2090 		int irq = port->irqs[i];
2091 
2092 		/*
2093 		 * Certain port types won't support all of the available
2094 		 * interrupt sources.
2095 		 */
2096 		if (unlikely(irq < 0))
2097 			continue;
2098 
2099 		/* Check if already freed (irq was muxed) */
2100 		for (j = 0; j < i; j++)
2101 			if (port->irqs[j] == irq)
2102 				j = i + 1;
2103 		if (j > i)
2104 			continue;
2105 
2106 		free_irq(port->irqs[i], port);
2107 		kfree(port->irqstr[i]);
2108 
2109 		if (SCIx_IRQ_IS_MUXED(port)) {
2110 			/* If there's only one IRQ, we're done. */
2111 			return;
2112 		}
2113 	}
2114 }
2115 
sci_tx_empty(struct uart_port * port)2116 static unsigned int sci_tx_empty(struct uart_port *port)
2117 {
2118 	unsigned short status = sci_serial_in(port, SCxSR);
2119 	unsigned short in_tx_fifo = sci_txfill(port);
2120 	struct sci_port *s = to_sci_port(port);
2121 
2122 	sci_dma_check_tx_occurred(s);
2123 
2124 	if (!s->tx_occurred)
2125 		return TIOCSER_TEMT;
2126 
2127 	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2128 }
2129 
sci_set_rts(struct uart_port * port,bool state)2130 static void sci_set_rts(struct uart_port *port, bool state)
2131 {
2132 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2133 		u16 data = sci_serial_in(port, SCPDR);
2134 
2135 		/* Active low */
2136 		if (state)
2137 			data &= ~SCPDR_RTSD;
2138 		else
2139 			data |= SCPDR_RTSD;
2140 		sci_serial_out(port, SCPDR, data);
2141 
2142 		/* RTS# is output */
2143 		sci_serial_out(port, SCPCR,
2144 			       sci_serial_in(port, SCPCR) | SCPCR_RTSC);
2145 	} else if (sci_getreg(port, SCSPTR)->size) {
2146 		u16 ctrl = sci_serial_in(port, SCSPTR);
2147 
2148 		/* Active low */
2149 		if (state)
2150 			ctrl &= ~SCSPTR_RTSDT;
2151 		else
2152 			ctrl |= SCSPTR_RTSDT;
2153 		sci_serial_out(port, SCSPTR, ctrl);
2154 	}
2155 }
2156 
sci_get_cts(struct uart_port * port)2157 static bool sci_get_cts(struct uart_port *port)
2158 {
2159 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2160 		/* Active low */
2161 		return !(sci_serial_in(port, SCPDR) & SCPDR_CTSD);
2162 	} else if (sci_getreg(port, SCSPTR)->size) {
2163 		/* Active low */
2164 		return !(sci_serial_in(port, SCSPTR) & SCSPTR_CTSDT);
2165 	}
2166 
2167 	return true;
2168 }
2169 
2170 /*
2171  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2172  * CTS/RTS is supported in hardware by at least one port and controlled
2173  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2174  * handled via the ->init_pins() op, which is a bit of a one-way street,
2175  * lacking any ability to defer pin control -- this will later be
2176  * converted over to the GPIO framework).
2177  *
2178  * Other modes (such as loopback) are supported generically on certain
2179  * port types, but not others. For these it's sufficient to test for the
2180  * existence of the support register and simply ignore the port type.
2181  */
sci_set_mctrl(struct uart_port * port,unsigned int mctrl)2182 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2183 {
2184 	struct sci_port *s = to_sci_port(port);
2185 
2186 	if (mctrl & TIOCM_LOOP) {
2187 		const struct plat_sci_reg *reg;
2188 
2189 		/*
2190 		 * Standard loopback mode for SCFCR ports.
2191 		 */
2192 		reg = sci_getreg(port, SCFCR);
2193 		if (reg->size)
2194 			sci_serial_out(port, SCFCR,
2195 				       sci_serial_in(port, SCFCR) | SCFCR_LOOP);
2196 	}
2197 
2198 	mctrl_gpio_set(s->gpios, mctrl);
2199 
2200 	if (!s->has_rtscts)
2201 		return;
2202 
2203 	if (!(mctrl & TIOCM_RTS)) {
2204 		/* Disable Auto RTS */
2205 		if (s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE)
2206 			sci_serial_out(port, SCFCR,
2207 				       sci_serial_in(port, SCFCR) & ~SCFCR_MCE);
2208 
2209 		/* Clear RTS */
2210 		sci_set_rts(port, 0);
2211 	} else if (s->autorts) {
2212 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2213 			/* Enable RTS# pin function */
2214 			sci_serial_out(port, SCPCR,
2215 				sci_serial_in(port, SCPCR) & ~SCPCR_RTSC);
2216 		}
2217 
2218 		/* Enable Auto RTS */
2219 		if (s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE)
2220 			sci_serial_out(port, SCFCR,
2221 				       sci_serial_in(port, SCFCR) | SCFCR_MCE);
2222 	} else {
2223 		/* Set RTS */
2224 		sci_set_rts(port, 1);
2225 	}
2226 }
2227 
sci_get_mctrl(struct uart_port * port)2228 static unsigned int sci_get_mctrl(struct uart_port *port)
2229 {
2230 	struct sci_port *s = to_sci_port(port);
2231 	struct mctrl_gpios *gpios = s->gpios;
2232 	unsigned int mctrl = 0;
2233 
2234 	mctrl_gpio_get(gpios, &mctrl);
2235 
2236 	/*
2237 	 * CTS/RTS is handled in hardware when supported, while nothing
2238 	 * else is wired up.
2239 	 */
2240 	if (s->autorts) {
2241 		if (sci_get_cts(port))
2242 			mctrl |= TIOCM_CTS;
2243 	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2244 		mctrl |= TIOCM_CTS;
2245 	}
2246 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2247 		mctrl |= TIOCM_DSR;
2248 	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2249 		mctrl |= TIOCM_CAR;
2250 
2251 	return mctrl;
2252 }
2253 
sci_enable_ms(struct uart_port * port)2254 static void sci_enable_ms(struct uart_port *port)
2255 {
2256 	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2257 }
2258 
sci_break_ctl(struct uart_port * port,int break_state)2259 static void sci_break_ctl(struct uart_port *port, int break_state)
2260 {
2261 	unsigned short scscr, scsptr;
2262 	unsigned long flags;
2263 
2264 	/* check whether the port has SCSPTR */
2265 	if (!sci_getreg(port, SCSPTR)->size) {
2266 		/*
2267 		 * Not supported by hardware. Most parts couple break and rx
2268 		 * interrupts together, with break detection always enabled.
2269 		 */
2270 		return;
2271 	}
2272 
2273 	uart_port_lock_irqsave(port, &flags);
2274 	scsptr = sci_serial_in(port, SCSPTR);
2275 	scscr = sci_serial_in(port, SCSCR);
2276 
2277 	if (break_state == -1) {
2278 		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2279 		scscr &= ~SCSCR_TE;
2280 	} else {
2281 		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2282 		scscr |= SCSCR_TE;
2283 	}
2284 
2285 	sci_serial_out(port, SCSPTR, scsptr);
2286 	sci_serial_out(port, SCSCR, scscr);
2287 	uart_port_unlock_irqrestore(port, flags);
2288 }
2289 
sci_startup(struct uart_port * port)2290 static int sci_startup(struct uart_port *port)
2291 {
2292 	struct sci_port *s = to_sci_port(port);
2293 	int ret;
2294 
2295 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2296 
2297 	s->tx_occurred = false;
2298 	sci_request_dma(port);
2299 
2300 	ret = sci_request_irq(s);
2301 	if (unlikely(ret < 0)) {
2302 		sci_free_dma(port);
2303 		return ret;
2304 	}
2305 
2306 	return 0;
2307 }
2308 
sci_shutdown(struct uart_port * port)2309 static void sci_shutdown(struct uart_port *port)
2310 {
2311 	struct sci_port *s = to_sci_port(port);
2312 	unsigned long flags;
2313 	u16 scr;
2314 
2315 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2316 
2317 	s->autorts = false;
2318 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2319 
2320 	uart_port_lock_irqsave(port, &flags);
2321 	sci_stop_rx(port);
2322 	sci_stop_tx(port);
2323 	/*
2324 	 * Stop RX and TX, disable related interrupts, keep clock source
2325 	 * and HSCIF TOT bits
2326 	 */
2327 	scr = sci_serial_in(port, SCSCR);
2328 	sci_serial_out(port, SCSCR,
2329 		       scr & (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2330 	uart_port_unlock_irqrestore(port, flags);
2331 
2332 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2333 	if (s->chan_rx_saved) {
2334 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2335 			port->line);
2336 		hrtimer_cancel(&s->rx_timer);
2337 	}
2338 #endif
2339 
2340 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2341 		del_timer_sync(&s->rx_fifo_timer);
2342 	sci_free_irq(s);
2343 	sci_free_dma(port);
2344 }
2345 
sci_sck_calc(struct sci_port * s,unsigned int bps,unsigned int * srr)2346 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2347 			unsigned int *srr)
2348 {
2349 	unsigned long freq = s->clk_rates[SCI_SCK];
2350 	int err, min_err = INT_MAX;
2351 	unsigned int sr;
2352 
2353 	if (s->port.type != PORT_HSCIF)
2354 		freq *= 2;
2355 
2356 	for_each_sr(sr, s) {
2357 		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2358 		if (abs(err) >= abs(min_err))
2359 			continue;
2360 
2361 		min_err = err;
2362 		*srr = sr - 1;
2363 
2364 		if (!err)
2365 			break;
2366 	}
2367 
2368 	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2369 		*srr + 1);
2370 	return min_err;
2371 }
2372 
sci_brg_calc(struct sci_port * s,unsigned int bps,unsigned long freq,unsigned int * dlr,unsigned int * srr)2373 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2374 			unsigned long freq, unsigned int *dlr,
2375 			unsigned int *srr)
2376 {
2377 	int err, min_err = INT_MAX;
2378 	unsigned int sr, dl;
2379 
2380 	if (s->port.type != PORT_HSCIF)
2381 		freq *= 2;
2382 
2383 	for_each_sr(sr, s) {
2384 		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2385 		dl = clamp(dl, 1U, 65535U);
2386 
2387 		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2388 		if (abs(err) >= abs(min_err))
2389 			continue;
2390 
2391 		min_err = err;
2392 		*dlr = dl;
2393 		*srr = sr - 1;
2394 
2395 		if (!err)
2396 			break;
2397 	}
2398 
2399 	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2400 		min_err, *dlr, *srr + 1);
2401 	return min_err;
2402 }
2403 
2404 /* calculate sample rate, BRR, and clock select */
sci_scbrr_calc(struct sci_port * s,unsigned int bps,unsigned int * brr,unsigned int * srr,unsigned int * cks)2405 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2406 			  unsigned int *brr, unsigned int *srr,
2407 			  unsigned int *cks)
2408 {
2409 	unsigned long freq = s->clk_rates[SCI_FCK];
2410 	unsigned int sr, br, prediv, scrate, c;
2411 	int err, min_err = INT_MAX;
2412 
2413 	if (s->port.type != PORT_HSCIF)
2414 		freq *= 2;
2415 
2416 	/*
2417 	 * Find the combination of sample rate and clock select with the
2418 	 * smallest deviation from the desired baud rate.
2419 	 * Prefer high sample rates to maximise the receive margin.
2420 	 *
2421 	 * M: Receive margin (%)
2422 	 * N: Ratio of bit rate to clock (N = sampling rate)
2423 	 * D: Clock duty (D = 0 to 1.0)
2424 	 * L: Frame length (L = 9 to 12)
2425 	 * F: Absolute value of clock frequency deviation
2426 	 *
2427 	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2428 	 *      (|D - 0.5| / N * (1 + F))|
2429 	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2430 	 */
2431 	for_each_sr(sr, s) {
2432 		for (c = 0; c <= 3; c++) {
2433 			/* integerized formulas from HSCIF documentation */
2434 			prediv = sr << (2 * c + 1);
2435 
2436 			/*
2437 			 * We need to calculate:
2438 			 *
2439 			 *     br = freq / (prediv * bps) clamped to [1..256]
2440 			 *     err = freq / (br * prediv) - bps
2441 			 *
2442 			 * Watch out for overflow when calculating the desired
2443 			 * sampling clock rate!
2444 			 */
2445 			if (bps > UINT_MAX / prediv)
2446 				break;
2447 
2448 			scrate = prediv * bps;
2449 			br = DIV_ROUND_CLOSEST(freq, scrate);
2450 			br = clamp(br, 1U, 256U);
2451 
2452 			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2453 			if (abs(err) >= abs(min_err))
2454 				continue;
2455 
2456 			min_err = err;
2457 			*brr = br - 1;
2458 			*srr = sr - 1;
2459 			*cks = c;
2460 
2461 			if (!err)
2462 				goto found;
2463 		}
2464 	}
2465 
2466 found:
2467 	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2468 		min_err, *brr, *srr + 1, *cks);
2469 	return min_err;
2470 }
2471 
sci_reset(struct uart_port * port)2472 static void sci_reset(struct uart_port *port)
2473 {
2474 	const struct plat_sci_reg *reg;
2475 	unsigned int status;
2476 	struct sci_port *s = to_sci_port(port);
2477 
2478 	sci_serial_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2479 
2480 	reg = sci_getreg(port, SCFCR);
2481 	if (reg->size)
2482 		sci_serial_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2483 
2484 	sci_clear_SCxSR(port,
2485 			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2486 			SCxSR_BREAK_CLEAR(port));
2487 	if (sci_getreg(port, SCLSR)->size) {
2488 		status = sci_serial_in(port, SCLSR);
2489 		status &= ~(SCLSR_TO | SCLSR_ORER);
2490 		sci_serial_out(port, SCLSR, status);
2491 	}
2492 
2493 	if (s->rx_trigger > 1) {
2494 		if (s->rx_fifo_timeout) {
2495 			scif_set_rtrg(port, 1);
2496 			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2497 		} else {
2498 			if (port->type == PORT_SCIFA ||
2499 			    port->type == PORT_SCIFB)
2500 				scif_set_rtrg(port, 1);
2501 			else
2502 				scif_set_rtrg(port, s->rx_trigger);
2503 		}
2504 	}
2505 }
2506 
sci_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)2507 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2508 		            const struct ktermios *old)
2509 {
2510 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2511 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2512 	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2513 	struct sci_port *s = to_sci_port(port);
2514 	const struct plat_sci_reg *reg;
2515 	int min_err = INT_MAX, err;
2516 	unsigned long max_freq = 0;
2517 	int best_clk = -1;
2518 	unsigned long flags;
2519 
2520 	if ((termios->c_cflag & CSIZE) == CS7) {
2521 		smr_val |= SCSMR_CHR;
2522 	} else {
2523 		termios->c_cflag &= ~CSIZE;
2524 		termios->c_cflag |= CS8;
2525 	}
2526 	if (termios->c_cflag & PARENB)
2527 		smr_val |= SCSMR_PE;
2528 	if (termios->c_cflag & PARODD)
2529 		smr_val |= SCSMR_PE | SCSMR_ODD;
2530 	if (termios->c_cflag & CSTOPB)
2531 		smr_val |= SCSMR_STOP;
2532 
2533 	/*
2534 	 * earlyprintk comes here early on with port->uartclk set to zero.
2535 	 * the clock framework is not up and running at this point so here
2536 	 * we assume that 115200 is the maximum baud rate. please note that
2537 	 * the baud rate is not programmed during earlyprintk - it is assumed
2538 	 * that the previous boot loader has enabled required clocks and
2539 	 * setup the baud rate generator hardware for us already.
2540 	 */
2541 	if (!port->uartclk) {
2542 		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2543 		goto done;
2544 	}
2545 
2546 	for (i = 0; i < SCI_NUM_CLKS; i++)
2547 		max_freq = max(max_freq, s->clk_rates[i]);
2548 
2549 	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2550 	if (!baud)
2551 		goto done;
2552 
2553 	/*
2554 	 * There can be multiple sources for the sampling clock.  Find the one
2555 	 * that gives us the smallest deviation from the desired baud rate.
2556 	 */
2557 
2558 	/* Optional Undivided External Clock */
2559 	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2560 	    port->type != PORT_SCIFB) {
2561 		err = sci_sck_calc(s, baud, &srr1);
2562 		if (abs(err) < abs(min_err)) {
2563 			best_clk = SCI_SCK;
2564 			scr_val = SCSCR_CKE1;
2565 			sccks = SCCKS_CKS;
2566 			min_err = err;
2567 			srr = srr1;
2568 			if (!err)
2569 				goto done;
2570 		}
2571 	}
2572 
2573 	/* Optional BRG Frequency Divided External Clock */
2574 	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2575 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2576 				   &srr1);
2577 		if (abs(err) < abs(min_err)) {
2578 			best_clk = SCI_SCIF_CLK;
2579 			scr_val = SCSCR_CKE1;
2580 			sccks = 0;
2581 			min_err = err;
2582 			dl = dl1;
2583 			srr = srr1;
2584 			if (!err)
2585 				goto done;
2586 		}
2587 	}
2588 
2589 	/* Optional BRG Frequency Divided Internal Clock */
2590 	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2591 		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2592 				   &srr1);
2593 		if (abs(err) < abs(min_err)) {
2594 			best_clk = SCI_BRG_INT;
2595 			scr_val = SCSCR_CKE1;
2596 			sccks = SCCKS_XIN;
2597 			min_err = err;
2598 			dl = dl1;
2599 			srr = srr1;
2600 			if (!min_err)
2601 				goto done;
2602 		}
2603 	}
2604 
2605 	/* Divided Functional Clock using standard Bit Rate Register */
2606 	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2607 	if (abs(err) < abs(min_err)) {
2608 		best_clk = SCI_FCK;
2609 		scr_val = 0;
2610 		min_err = err;
2611 		brr = brr1;
2612 		srr = srr1;
2613 		cks = cks1;
2614 	}
2615 
2616 done:
2617 	if (best_clk >= 0)
2618 		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2619 			s->clks[best_clk], baud, min_err);
2620 
2621 	sci_port_enable(s);
2622 
2623 	/*
2624 	 * Program the optional External Baud Rate Generator (BRG) first.
2625 	 * It controls the mux to select (H)SCK or frequency divided clock.
2626 	 */
2627 	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2628 		sci_serial_out(port, SCDL, dl);
2629 		sci_serial_out(port, SCCKS, sccks);
2630 	}
2631 
2632 	uart_port_lock_irqsave(port, &flags);
2633 
2634 	sci_reset(port);
2635 
2636 	uart_update_timeout(port, termios->c_cflag, baud);
2637 
2638 	/* byte size and parity */
2639 	bits = tty_get_frame_size(termios->c_cflag);
2640 
2641 	if (sci_getreg(port, SEMR)->size)
2642 		sci_serial_out(port, SEMR, 0);
2643 
2644 	if (best_clk >= 0) {
2645 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2646 			switch (srr + 1) {
2647 			case 5:  smr_val |= SCSMR_SRC_5;  break;
2648 			case 7:  smr_val |= SCSMR_SRC_7;  break;
2649 			case 11: smr_val |= SCSMR_SRC_11; break;
2650 			case 13: smr_val |= SCSMR_SRC_13; break;
2651 			case 16: smr_val |= SCSMR_SRC_16; break;
2652 			case 17: smr_val |= SCSMR_SRC_17; break;
2653 			case 19: smr_val |= SCSMR_SRC_19; break;
2654 			case 27: smr_val |= SCSMR_SRC_27; break;
2655 			}
2656 		smr_val |= cks;
2657 		sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2658 		sci_serial_out(port, SCSMR, smr_val);
2659 		sci_serial_out(port, SCBRR, brr);
2660 		if (sci_getreg(port, HSSRR)->size) {
2661 			unsigned int hssrr = srr | HSCIF_SRE;
2662 			/* Calculate deviation from intended rate at the
2663 			 * center of the last stop bit in sampling clocks.
2664 			 */
2665 			int last_stop = bits * 2 - 1;
2666 			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2667 							  (int)(srr + 1),
2668 							  2 * (int)baud);
2669 
2670 			if (abs(deviation) >= 2) {
2671 				/* At least two sampling clocks off at the
2672 				 * last stop bit; we can increase the error
2673 				 * margin by shifting the sampling point.
2674 				 */
2675 				int shift = clamp(deviation / 2, -8, 7);
2676 
2677 				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2678 					 HSCIF_SRHP_MASK;
2679 				hssrr |= HSCIF_SRDE;
2680 			}
2681 			sci_serial_out(port, HSSRR, hssrr);
2682 		}
2683 
2684 		/* Wait one bit interval */
2685 		udelay((1000000 + (baud - 1)) / baud);
2686 	} else {
2687 		/* Don't touch the bit rate configuration */
2688 		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2689 		smr_val |= sci_serial_in(port, SCSMR) &
2690 			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2691 		sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2692 		sci_serial_out(port, SCSMR, smr_val);
2693 	}
2694 
2695 	sci_init_pins(port, termios->c_cflag);
2696 
2697 	port->status &= ~UPSTAT_AUTOCTS;
2698 	s->autorts = false;
2699 	reg = sci_getreg(port, SCFCR);
2700 	if (reg->size) {
2701 		unsigned short ctrl = sci_serial_in(port, SCFCR);
2702 
2703 		if ((port->flags & UPF_HARD_FLOW) &&
2704 		    (termios->c_cflag & CRTSCTS)) {
2705 			/* There is no CTS interrupt to restart the hardware */
2706 			port->status |= UPSTAT_AUTOCTS;
2707 			/* MCE is enabled when RTS is raised */
2708 			s->autorts = true;
2709 		}
2710 
2711 		/*
2712 		 * As we've done a sci_reset() above, ensure we don't
2713 		 * interfere with the FIFOs while toggling MCE. As the
2714 		 * reset values could still be set, simply mask them out.
2715 		 */
2716 		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2717 
2718 		sci_serial_out(port, SCFCR, ctrl);
2719 	}
2720 	if (port->flags & UPF_HARD_FLOW) {
2721 		/* Refresh (Auto) RTS */
2722 		sci_set_mctrl(port, port->mctrl);
2723 	}
2724 
2725 	/*
2726 	 * For SCI, TE (transmit enable) must be set after setting TIE
2727 	 * (transmit interrupt enable) or in the same instruction to
2728 	 * start the transmitting process. So skip setting TE here for SCI.
2729 	 */
2730 	if (port->type != PORT_SCI)
2731 		scr_val |= SCSCR_TE;
2732 	scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2733 	sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
2734 	if ((srr + 1 == 5) &&
2735 	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2736 		/*
2737 		 * In asynchronous mode, when the sampling rate is 1/5, first
2738 		 * received data may become invalid on some SCIFA and SCIFB.
2739 		 * To avoid this problem wait more than 1 serial data time (1
2740 		 * bit time x serial data number) after setting SCSCR.RE = 1.
2741 		 */
2742 		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2743 	}
2744 
2745 	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2746 	s->rx_frame = (10000 * bits) / (baud / 100);
2747 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2748 	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2749 #endif
2750 
2751 	if ((termios->c_cflag & CREAD) != 0)
2752 		sci_start_rx(port);
2753 
2754 	uart_port_unlock_irqrestore(port, flags);
2755 
2756 	sci_port_disable(s);
2757 
2758 	if (UART_ENABLE_MS(port, termios->c_cflag))
2759 		sci_enable_ms(port);
2760 }
2761 
sci_pm(struct uart_port * port,unsigned int state,unsigned int oldstate)2762 static void sci_pm(struct uart_port *port, unsigned int state,
2763 		   unsigned int oldstate)
2764 {
2765 	struct sci_port *sci_port = to_sci_port(port);
2766 
2767 	switch (state) {
2768 	case UART_PM_STATE_OFF:
2769 		sci_port_disable(sci_port);
2770 		break;
2771 	default:
2772 		sci_port_enable(sci_port);
2773 		break;
2774 	}
2775 }
2776 
sci_type(struct uart_port * port)2777 static const char *sci_type(struct uart_port *port)
2778 {
2779 	switch (port->type) {
2780 	case PORT_IRDA:
2781 		return "irda";
2782 	case PORT_SCI:
2783 		return "sci";
2784 	case PORT_SCIF:
2785 		return "scif";
2786 	case PORT_SCIFA:
2787 		return "scifa";
2788 	case PORT_SCIFB:
2789 		return "scifb";
2790 	case PORT_HSCIF:
2791 		return "hscif";
2792 	}
2793 
2794 	return NULL;
2795 }
2796 
sci_remap_port(struct uart_port * port)2797 static int sci_remap_port(struct uart_port *port)
2798 {
2799 	struct sci_port *sport = to_sci_port(port);
2800 
2801 	/*
2802 	 * Nothing to do if there's already an established membase.
2803 	 */
2804 	if (port->membase)
2805 		return 0;
2806 
2807 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2808 		port->membase = ioremap(port->mapbase, sport->reg_size);
2809 		if (unlikely(!port->membase)) {
2810 			dev_err(port->dev, "can't remap port#%d\n", port->line);
2811 			return -ENXIO;
2812 		}
2813 	} else {
2814 		/*
2815 		 * For the simple (and majority of) cases where we don't
2816 		 * need to do any remapping, just cast the cookie
2817 		 * directly.
2818 		 */
2819 		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2820 	}
2821 
2822 	return 0;
2823 }
2824 
sci_release_port(struct uart_port * port)2825 static void sci_release_port(struct uart_port *port)
2826 {
2827 	struct sci_port *sport = to_sci_port(port);
2828 
2829 	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2830 		iounmap(port->membase);
2831 		port->membase = NULL;
2832 	}
2833 
2834 	release_mem_region(port->mapbase, sport->reg_size);
2835 }
2836 
sci_request_port(struct uart_port * port)2837 static int sci_request_port(struct uart_port *port)
2838 {
2839 	struct resource *res;
2840 	struct sci_port *sport = to_sci_port(port);
2841 	int ret;
2842 
2843 	res = request_mem_region(port->mapbase, sport->reg_size,
2844 				 dev_name(port->dev));
2845 	if (unlikely(res == NULL)) {
2846 		dev_err(port->dev, "request_mem_region failed.");
2847 		return -EBUSY;
2848 	}
2849 
2850 	ret = sci_remap_port(port);
2851 	if (unlikely(ret != 0)) {
2852 		release_resource(res);
2853 		return ret;
2854 	}
2855 
2856 	return 0;
2857 }
2858 
sci_config_port(struct uart_port * port,int flags)2859 static void sci_config_port(struct uart_port *port, int flags)
2860 {
2861 	if (flags & UART_CONFIG_TYPE) {
2862 		struct sci_port *sport = to_sci_port(port);
2863 
2864 		port->type = sport->cfg->type;
2865 		sci_request_port(port);
2866 	}
2867 }
2868 
sci_verify_port(struct uart_port * port,struct serial_struct * ser)2869 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2870 {
2871 	if (ser->baud_base < 2400)
2872 		/* No paper tape reader for Mitch.. */
2873 		return -EINVAL;
2874 
2875 	return 0;
2876 }
2877 
2878 static const struct uart_ops sci_uart_ops = {
2879 	.tx_empty	= sci_tx_empty,
2880 	.set_mctrl	= sci_set_mctrl,
2881 	.get_mctrl	= sci_get_mctrl,
2882 	.start_tx	= sci_start_tx,
2883 	.stop_tx	= sci_stop_tx,
2884 	.stop_rx	= sci_stop_rx,
2885 	.enable_ms	= sci_enable_ms,
2886 	.break_ctl	= sci_break_ctl,
2887 	.startup	= sci_startup,
2888 	.shutdown	= sci_shutdown,
2889 	.flush_buffer	= sci_flush_buffer,
2890 	.set_termios	= sci_set_termios,
2891 	.pm		= sci_pm,
2892 	.type		= sci_type,
2893 	.release_port	= sci_release_port,
2894 	.request_port	= sci_request_port,
2895 	.config_port	= sci_config_port,
2896 	.verify_port	= sci_verify_port,
2897 #ifdef CONFIG_CONSOLE_POLL
2898 	.poll_get_char	= sci_poll_get_char,
2899 	.poll_put_char	= sci_poll_put_char,
2900 #endif
2901 };
2902 
sci_init_clocks(struct sci_port * sci_port,struct device * dev)2903 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2904 {
2905 	const char *clk_names[] = {
2906 		[SCI_FCK] = "fck",
2907 		[SCI_SCK] = "sck",
2908 		[SCI_BRG_INT] = "brg_int",
2909 		[SCI_SCIF_CLK] = "scif_clk",
2910 	};
2911 	struct clk *clk;
2912 	unsigned int i;
2913 
2914 	if (sci_port->cfg->type == PORT_HSCIF)
2915 		clk_names[SCI_SCK] = "hsck";
2916 
2917 	for (i = 0; i < SCI_NUM_CLKS; i++) {
2918 		clk = devm_clk_get_optional(dev, clk_names[i]);
2919 		if (IS_ERR(clk))
2920 			return PTR_ERR(clk);
2921 
2922 		if (!clk && i == SCI_FCK) {
2923 			/*
2924 			 * Not all SH platforms declare a clock lookup entry
2925 			 * for SCI devices, in which case we need to get the
2926 			 * global "peripheral_clk" clock.
2927 			 */
2928 			clk = devm_clk_get(dev, "peripheral_clk");
2929 			if (IS_ERR(clk))
2930 				return dev_err_probe(dev, PTR_ERR(clk),
2931 						     "failed to get %s\n",
2932 						     clk_names[i]);
2933 		}
2934 
2935 		if (!clk)
2936 			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2937 		else
2938 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2939 				clk, clk_get_rate(clk));
2940 		sci_port->clks[i] = clk;
2941 	}
2942 	return 0;
2943 }
2944 
2945 static const struct sci_port_params *
sci_probe_regmap(const struct plat_sci_port * cfg)2946 sci_probe_regmap(const struct plat_sci_port *cfg)
2947 {
2948 	unsigned int regtype;
2949 
2950 	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2951 		return &sci_port_params[cfg->regtype];
2952 
2953 	switch (cfg->type) {
2954 	case PORT_SCI:
2955 		regtype = SCIx_SCI_REGTYPE;
2956 		break;
2957 	case PORT_IRDA:
2958 		regtype = SCIx_IRDA_REGTYPE;
2959 		break;
2960 	case PORT_SCIFA:
2961 		regtype = SCIx_SCIFA_REGTYPE;
2962 		break;
2963 	case PORT_SCIFB:
2964 		regtype = SCIx_SCIFB_REGTYPE;
2965 		break;
2966 	case PORT_SCIF:
2967 		/*
2968 		 * The SH-4 is a bit of a misnomer here, although that's
2969 		 * where this particular port layout originated. This
2970 		 * configuration (or some slight variation thereof)
2971 		 * remains the dominant model for all SCIFs.
2972 		 */
2973 		regtype = SCIx_SH4_SCIF_REGTYPE;
2974 		break;
2975 	case PORT_HSCIF:
2976 		regtype = SCIx_HSCIF_REGTYPE;
2977 		break;
2978 	default:
2979 		pr_err("Can't probe register map for given port\n");
2980 		return NULL;
2981 	}
2982 
2983 	return &sci_port_params[regtype];
2984 }
2985 
sci_init_single(struct platform_device * dev,struct sci_port * sci_port,unsigned int index,const struct plat_sci_port * p,bool early)2986 static int sci_init_single(struct platform_device *dev,
2987 			   struct sci_port *sci_port, unsigned int index,
2988 			   const struct plat_sci_port *p, bool early)
2989 {
2990 	struct uart_port *port = &sci_port->port;
2991 	const struct resource *res;
2992 	unsigned int i;
2993 	int ret;
2994 
2995 	sci_port->cfg	= p;
2996 
2997 	port->ops	= &sci_uart_ops;
2998 	port->iotype	= UPIO_MEM;
2999 	port->line	= index;
3000 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
3001 
3002 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
3003 	if (res == NULL)
3004 		return -ENOMEM;
3005 
3006 	port->mapbase = res->start;
3007 	sci_port->reg_size = resource_size(res);
3008 
3009 	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
3010 		if (i)
3011 			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
3012 		else
3013 			sci_port->irqs[i] = platform_get_irq(dev, i);
3014 	}
3015 
3016 	/*
3017 	 * The fourth interrupt on SCI port is transmit end interrupt, so
3018 	 * shuffle the interrupts.
3019 	 */
3020 	if (p->type == PORT_SCI)
3021 		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
3022 
3023 	/* The SCI generates several interrupts. They can be muxed together or
3024 	 * connected to different interrupt lines. In the muxed case only one
3025 	 * interrupt resource is specified as there is only one interrupt ID.
3026 	 * In the non-muxed case, up to 6 interrupt signals might be generated
3027 	 * from the SCI, however those signals might have their own individual
3028 	 * interrupt ID numbers, or muxed together with another interrupt.
3029 	 */
3030 	if (sci_port->irqs[0] < 0)
3031 		return -ENXIO;
3032 
3033 	if (sci_port->irqs[1] < 0)
3034 		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
3035 			sci_port->irqs[i] = sci_port->irqs[0];
3036 
3037 	sci_port->params = sci_probe_regmap(p);
3038 	if (unlikely(sci_port->params == NULL))
3039 		return -EINVAL;
3040 
3041 	switch (p->type) {
3042 	case PORT_SCIFB:
3043 		sci_port->rx_trigger = 48;
3044 		break;
3045 	case PORT_HSCIF:
3046 		sci_port->rx_trigger = 64;
3047 		break;
3048 	case PORT_SCIFA:
3049 		sci_port->rx_trigger = 32;
3050 		break;
3051 	case PORT_SCIF:
3052 		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
3053 			/* RX triggering not implemented for this IP */
3054 			sci_port->rx_trigger = 1;
3055 		else
3056 			sci_port->rx_trigger = 8;
3057 		break;
3058 	default:
3059 		sci_port->rx_trigger = 1;
3060 		break;
3061 	}
3062 
3063 	sci_port->rx_fifo_timeout = 0;
3064 	sci_port->hscif_tot = 0;
3065 
3066 	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
3067 	 * match the SoC datasheet, this should be investigated. Let platform
3068 	 * data override the sampling rate for now.
3069 	 */
3070 	sci_port->sampling_rate_mask = p->sampling_rate
3071 				     ? SCI_SR(p->sampling_rate)
3072 				     : sci_port->params->sampling_rate_mask;
3073 
3074 	if (!early) {
3075 		ret = sci_init_clocks(sci_port, &dev->dev);
3076 		if (ret < 0)
3077 			return ret;
3078 	}
3079 
3080 	port->type		= p->type;
3081 	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
3082 	port->fifosize		= sci_port->params->fifosize;
3083 
3084 	if (port->type == PORT_SCI && !dev->dev.of_node) {
3085 		if (sci_port->reg_size >= 0x20)
3086 			port->regshift = 2;
3087 		else
3088 			port->regshift = 1;
3089 	}
3090 
3091 	/*
3092 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
3093 	 * for the multi-IRQ ports, which is where we are primarily
3094 	 * concerned with the shutdown path synchronization.
3095 	 *
3096 	 * For the muxed case there's nothing more to do.
3097 	 */
3098 	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
3099 	port->irqflags		= 0;
3100 
3101 	return 0;
3102 }
3103 
3104 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3105     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
serial_console_putchar(struct uart_port * port,unsigned char ch)3106 static void serial_console_putchar(struct uart_port *port, unsigned char ch)
3107 {
3108 	sci_poll_put_char(port, ch);
3109 }
3110 
3111 /*
3112  *	Print a string to the serial port trying not to disturb
3113  *	any possible real use of the port...
3114  */
serial_console_write(struct console * co,const char * s,unsigned count)3115 static void serial_console_write(struct console *co, const char *s,
3116 				 unsigned count)
3117 {
3118 	struct sci_port *sci_port = &sci_ports[co->index];
3119 	struct uart_port *port = &sci_port->port;
3120 	unsigned short bits, ctrl, ctrl_temp;
3121 	unsigned long flags;
3122 	int locked = 1;
3123 
3124 	if (port->sysrq)
3125 		locked = 0;
3126 	else if (oops_in_progress)
3127 		locked = uart_port_trylock_irqsave(port, &flags);
3128 	else
3129 		uart_port_lock_irqsave(port, &flags);
3130 
3131 	/* first save SCSCR then disable interrupts, keep clock source */
3132 	ctrl = sci_serial_in(port, SCSCR);
3133 	ctrl_temp = SCSCR_RE | SCSCR_TE |
3134 		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3135 		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3136 	sci_serial_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3137 
3138 	uart_console_write(port, s, count, serial_console_putchar);
3139 
3140 	/* wait until fifo is empty and last bit has been transmitted */
3141 	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3142 	while ((sci_serial_in(port, SCxSR) & bits) != bits)
3143 		cpu_relax();
3144 
3145 	/* restore the SCSCR */
3146 	sci_serial_out(port, SCSCR, ctrl);
3147 
3148 	if (locked)
3149 		uart_port_unlock_irqrestore(port, flags);
3150 }
3151 
serial_console_setup(struct console * co,char * options)3152 static int serial_console_setup(struct console *co, char *options)
3153 {
3154 	struct sci_port *sci_port;
3155 	struct uart_port *port;
3156 	int baud = 115200;
3157 	int bits = 8;
3158 	int parity = 'n';
3159 	int flow = 'n';
3160 	int ret;
3161 
3162 	/*
3163 	 * Refuse to handle any bogus ports.
3164 	 */
3165 	if (co->index < 0 || co->index >= SCI_NPORTS)
3166 		return -ENODEV;
3167 
3168 	sci_port = &sci_ports[co->index];
3169 	port = &sci_port->port;
3170 
3171 	/*
3172 	 * Refuse to handle uninitialized ports.
3173 	 */
3174 	if (!port->ops)
3175 		return -ENODEV;
3176 
3177 	ret = sci_remap_port(port);
3178 	if (unlikely(ret != 0))
3179 		return ret;
3180 
3181 	if (options)
3182 		uart_parse_options(options, &baud, &parity, &bits, &flow);
3183 
3184 	return uart_set_options(port, co, baud, parity, bits, flow);
3185 }
3186 
3187 static struct console serial_console = {
3188 	.name		= "ttySC",
3189 	.device		= uart_console_device,
3190 	.write		= serial_console_write,
3191 	.setup		= serial_console_setup,
3192 	.flags		= CON_PRINTBUFFER,
3193 	.index		= -1,
3194 	.data		= &sci_uart_driver,
3195 };
3196 
3197 #ifdef CONFIG_SUPERH
3198 static char early_serial_buf[32];
3199 
early_serial_console_setup(struct console * co,char * options)3200 static int early_serial_console_setup(struct console *co, char *options)
3201 {
3202 	/*
3203 	 * This early console is always registered using the earlyprintk=
3204 	 * parameter, which does not call add_preferred_console(). Thus
3205 	 * @options is always NULL and the options for this early console
3206 	 * are passed using a custom buffer.
3207 	 */
3208 	WARN_ON(options);
3209 
3210 	return serial_console_setup(co, early_serial_buf);
3211 }
3212 
3213 static struct console early_serial_console = {
3214 	.name           = "early_ttySC",
3215 	.write          = serial_console_write,
3216 	.setup		= early_serial_console_setup,
3217 	.flags          = CON_PRINTBUFFER,
3218 	.index		= -1,
3219 };
3220 
sci_probe_earlyprintk(struct platform_device * pdev)3221 static int sci_probe_earlyprintk(struct platform_device *pdev)
3222 {
3223 	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3224 
3225 	if (early_serial_console.data)
3226 		return -EEXIST;
3227 
3228 	early_serial_console.index = pdev->id;
3229 
3230 	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3231 
3232 	if (!strstr(early_serial_buf, "keep"))
3233 		early_serial_console.flags |= CON_BOOT;
3234 
3235 	register_console(&early_serial_console);
3236 	return 0;
3237 }
3238 #endif
3239 
3240 #define SCI_CONSOLE	(&serial_console)
3241 
3242 #else
sci_probe_earlyprintk(struct platform_device * pdev)3243 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3244 {
3245 	return -EINVAL;
3246 }
3247 
3248 #define SCI_CONSOLE	NULL
3249 
3250 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3251 
3252 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3253 
3254 static DEFINE_MUTEX(sci_uart_registration_lock);
3255 static struct uart_driver sci_uart_driver = {
3256 	.owner		= THIS_MODULE,
3257 	.driver_name	= "sci",
3258 	.dev_name	= "ttySC",
3259 	.major		= SCI_MAJOR,
3260 	.minor		= SCI_MINOR_START,
3261 	.nr		= SCI_NPORTS,
3262 	.cons		= SCI_CONSOLE,
3263 };
3264 
sci_remove(struct platform_device * dev)3265 static void sci_remove(struct platform_device *dev)
3266 {
3267 	struct sci_port *port = platform_get_drvdata(dev);
3268 	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3269 
3270 	sci_ports_in_use &= ~BIT(port->port.line);
3271 	uart_remove_one_port(&sci_uart_driver, &port->port);
3272 
3273 	if (port->port.fifosize > 1)
3274 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3275 	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3276 		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3277 }
3278 
3279 
3280 #define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3281 #define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3282 #define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3283 
3284 static const struct of_device_id of_sci_match[] __maybe_unused = {
3285 	/* SoC-specific types */
3286 	{
3287 		.compatible = "renesas,scif-r7s72100",
3288 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3289 	},
3290 	{
3291 		.compatible = "renesas,scif-r7s9210",
3292 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3293 	},
3294 	{
3295 		.compatible = "renesas,scif-r9a07g044",
3296 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3297 	},
3298 	{
3299 		.compatible = "renesas,scif-r9a09g057",
3300 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZV2H_SCIF_REGTYPE),
3301 	},
3302 	/* Family-specific types */
3303 	{
3304 		.compatible = "renesas,rcar-gen1-scif",
3305 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3306 	}, {
3307 		.compatible = "renesas,rcar-gen2-scif",
3308 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3309 	}, {
3310 		.compatible = "renesas,rcar-gen3-scif",
3311 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3312 	}, {
3313 		.compatible = "renesas,rcar-gen4-scif",
3314 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3315 	},
3316 	/* Generic types */
3317 	{
3318 		.compatible = "renesas,scif",
3319 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3320 	}, {
3321 		.compatible = "renesas,scifa",
3322 		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3323 	}, {
3324 		.compatible = "renesas,scifb",
3325 		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3326 	}, {
3327 		.compatible = "renesas,hscif",
3328 		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3329 	}, {
3330 		.compatible = "renesas,sci",
3331 		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3332 	}, {
3333 		/* Terminator */
3334 	},
3335 };
3336 MODULE_DEVICE_TABLE(of, of_sci_match);
3337 
sci_reset_control_assert(void * data)3338 static void sci_reset_control_assert(void *data)
3339 {
3340 	reset_control_assert(data);
3341 }
3342 
sci_parse_dt(struct platform_device * pdev,unsigned int * dev_id)3343 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3344 					  unsigned int *dev_id)
3345 {
3346 	struct device_node *np = pdev->dev.of_node;
3347 	struct reset_control *rstc;
3348 	struct plat_sci_port *p;
3349 	struct sci_port *sp;
3350 	const void *data;
3351 	int id, ret;
3352 
3353 	if (!IS_ENABLED(CONFIG_OF) || !np)
3354 		return ERR_PTR(-EINVAL);
3355 
3356 	data = of_device_get_match_data(&pdev->dev);
3357 
3358 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3359 	if (IS_ERR(rstc))
3360 		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3361 					     "failed to get reset ctrl\n"));
3362 
3363 	ret = reset_control_deassert(rstc);
3364 	if (ret) {
3365 		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3366 		return ERR_PTR(ret);
3367 	}
3368 
3369 	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3370 	if (ret) {
3371 		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3372 			ret);
3373 		return ERR_PTR(ret);
3374 	}
3375 
3376 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3377 	if (!p)
3378 		return ERR_PTR(-ENOMEM);
3379 
3380 	/* Get the line number from the aliases node. */
3381 	id = of_alias_get_id(np, "serial");
3382 	if (id < 0 && ~sci_ports_in_use)
3383 		id = ffz(sci_ports_in_use);
3384 	if (id < 0) {
3385 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3386 		return ERR_PTR(-EINVAL);
3387 	}
3388 	if (id >= ARRAY_SIZE(sci_ports)) {
3389 		dev_err(&pdev->dev, "serial%d out of range\n", id);
3390 		return ERR_PTR(-EINVAL);
3391 	}
3392 
3393 	sp = &sci_ports[id];
3394 	sp->rstc = rstc;
3395 	*dev_id = id;
3396 
3397 	p->type = SCI_OF_TYPE(data);
3398 	p->regtype = SCI_OF_REGTYPE(data);
3399 
3400 	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3401 
3402 	return p;
3403 }
3404 
sci_probe_single(struct platform_device * dev,unsigned int index,struct plat_sci_port * p,struct sci_port * sciport,struct resource * sci_res)3405 static int sci_probe_single(struct platform_device *dev,
3406 				      unsigned int index,
3407 				      struct plat_sci_port *p,
3408 				      struct sci_port *sciport,
3409 				      struct resource *sci_res)
3410 {
3411 	int ret;
3412 
3413 	/* Sanity check */
3414 	if (unlikely(index >= SCI_NPORTS)) {
3415 		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3416 			   index+1, SCI_NPORTS);
3417 		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3418 		return -EINVAL;
3419 	}
3420 	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3421 	if (sci_ports_in_use & BIT(index))
3422 		return -EBUSY;
3423 
3424 	mutex_lock(&sci_uart_registration_lock);
3425 	if (!sci_uart_driver.state) {
3426 		ret = uart_register_driver(&sci_uart_driver);
3427 		if (ret) {
3428 			mutex_unlock(&sci_uart_registration_lock);
3429 			return ret;
3430 		}
3431 	}
3432 	mutex_unlock(&sci_uart_registration_lock);
3433 
3434 	ret = sci_init_single(dev, sciport, index, p, false);
3435 	if (ret)
3436 		return ret;
3437 
3438 	sciport->port.dev = &dev->dev;
3439 	ret = devm_pm_runtime_enable(&dev->dev);
3440 	if (ret)
3441 		return ret;
3442 
3443 	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3444 	if (IS_ERR(sciport->gpios))
3445 		return PTR_ERR(sciport->gpios);
3446 
3447 	if (sciport->has_rtscts) {
3448 		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3449 		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3450 			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3451 			return -EINVAL;
3452 		}
3453 		sciport->port.flags |= UPF_HARD_FLOW;
3454 	}
3455 
3456 	if (sci_uart_earlycon && sci_ports[0].port.mapbase == sci_res->start) {
3457 		/*
3458 		 * In case:
3459 		 * - this is the earlycon port (mapped on index 0 in sci_ports[]) and
3460 		 * - it now maps to an alias other than zero and
3461 		 * - the earlycon is still alive (e.g., "earlycon keep_bootcon" is
3462 		 *   available in bootargs)
3463 		 *
3464 		 * we need to avoid disabling clocks and PM domains through the runtime
3465 		 * PM APIs called in __device_attach(). For this, increment the runtime
3466 		 * PM reference counter (the clocks and PM domains were already enabled
3467 		 * by the bootloader). Otherwise the earlycon may access the HW when it
3468 		 * has no clocks enabled leading to failures (infinite loop in
3469 		 * sci_poll_put_char()).
3470 		 */
3471 		pm_runtime_get_noresume(&dev->dev);
3472 
3473 		/*
3474 		 * Skip cleanup the sci_port[0] in early_console_exit(), this
3475 		 * port is the same as the earlycon one.
3476 		 */
3477 		sci_uart_earlycon_dev_probing = true;
3478 	}
3479 
3480 	return uart_add_one_port(&sci_uart_driver, &sciport->port);
3481 }
3482 
sci_probe(struct platform_device * dev)3483 static int sci_probe(struct platform_device *dev)
3484 {
3485 	struct plat_sci_port *p;
3486 	struct resource *res;
3487 	struct sci_port *sp;
3488 	unsigned int dev_id;
3489 	int ret;
3490 
3491 	/*
3492 	 * If we've come here via earlyprintk initialization, head off to
3493 	 * the special early probe. We don't have sufficient device state
3494 	 * to make it beyond this yet.
3495 	 */
3496 #ifdef CONFIG_SUPERH
3497 	if (is_sh_early_platform_device(dev))
3498 		return sci_probe_earlyprintk(dev);
3499 #endif
3500 
3501 	if (dev->dev.of_node) {
3502 		p = sci_parse_dt(dev, &dev_id);
3503 		if (IS_ERR(p))
3504 			return PTR_ERR(p);
3505 	} else {
3506 		p = dev->dev.platform_data;
3507 		if (p == NULL) {
3508 			dev_err(&dev->dev, "no platform data supplied\n");
3509 			return -EINVAL;
3510 		}
3511 
3512 		dev_id = dev->id;
3513 	}
3514 
3515 	sp = &sci_ports[dev_id];
3516 
3517 	/*
3518 	 * In case:
3519 	 * - the probed port alias is zero (as the one used by earlycon), and
3520 	 * - the earlycon is still active (e.g., "earlycon keep_bootcon" in
3521 	 *   bootargs)
3522 	 *
3523 	 * defer the probe of this serial. This is a debug scenario and the user
3524 	 * must be aware of it.
3525 	 *
3526 	 * Except when the probed port is the same as the earlycon port.
3527 	 */
3528 
3529 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
3530 	if (!res)
3531 		return -ENODEV;
3532 
3533 	if (sci_uart_earlycon && sp == &sci_ports[0] && sp->port.mapbase != res->start)
3534 		return dev_err_probe(&dev->dev, -EBUSY, "sci_port[0] is used by earlycon!\n");
3535 
3536 	platform_set_drvdata(dev, sp);
3537 
3538 	ret = sci_probe_single(dev, dev_id, p, sp, res);
3539 	if (ret)
3540 		return ret;
3541 
3542 	if (sp->port.fifosize > 1) {
3543 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3544 		if (ret)
3545 			return ret;
3546 	}
3547 	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3548 	    sp->port.type == PORT_HSCIF) {
3549 		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3550 		if (ret) {
3551 			if (sp->port.fifosize > 1) {
3552 				device_remove_file(&dev->dev,
3553 						   &dev_attr_rx_fifo_trigger);
3554 			}
3555 			return ret;
3556 		}
3557 	}
3558 
3559 #ifdef CONFIG_SH_STANDARD_BIOS
3560 	sh_bios_gdb_detach();
3561 #endif
3562 
3563 	sci_ports_in_use |= BIT(dev_id);
3564 	return 0;
3565 }
3566 
sci_console_save(struct sci_port * s)3567 static void sci_console_save(struct sci_port *s)
3568 {
3569 	struct sci_suspend_regs *regs = &s->suspend_regs;
3570 	struct uart_port *port = &s->port;
3571 
3572 	if (sci_getreg(port, SCDL)->size)
3573 		regs->scdl = sci_serial_in(port, SCDL);
3574 	if (sci_getreg(port, SCCKS)->size)
3575 		regs->sccks = sci_serial_in(port, SCCKS);
3576 	if (sci_getreg(port, SCSMR)->size)
3577 		regs->scsmr = sci_serial_in(port, SCSMR);
3578 	if (sci_getreg(port, SCSCR)->size)
3579 		regs->scscr = sci_serial_in(port, SCSCR);
3580 	if (sci_getreg(port, SCFCR)->size)
3581 		regs->scfcr = sci_serial_in(port, SCFCR);
3582 	if (sci_getreg(port, SCSPTR)->size)
3583 		regs->scsptr = sci_serial_in(port, SCSPTR);
3584 	if (sci_getreg(port, SCBRR)->size)
3585 		regs->scbrr = sci_serial_in(port, SCBRR);
3586 	if (sci_getreg(port, HSSRR)->size)
3587 		regs->hssrr = sci_serial_in(port, HSSRR);
3588 	if (sci_getreg(port, SCPCR)->size)
3589 		regs->scpcr = sci_serial_in(port, SCPCR);
3590 	if (sci_getreg(port, SCPDR)->size)
3591 		regs->scpdr = sci_serial_in(port, SCPDR);
3592 	if (sci_getreg(port, SEMR)->size)
3593 		regs->semr = sci_serial_in(port, SEMR);
3594 }
3595 
sci_console_restore(struct sci_port * s)3596 static void sci_console_restore(struct sci_port *s)
3597 {
3598 	struct sci_suspend_regs *regs = &s->suspend_regs;
3599 	struct uart_port *port = &s->port;
3600 
3601 	if (sci_getreg(port, SCDL)->size)
3602 		sci_serial_out(port, SCDL, regs->scdl);
3603 	if (sci_getreg(port, SCCKS)->size)
3604 		sci_serial_out(port, SCCKS, regs->sccks);
3605 	if (sci_getreg(port, SCSMR)->size)
3606 		sci_serial_out(port, SCSMR, regs->scsmr);
3607 	if (sci_getreg(port, SCSCR)->size)
3608 		sci_serial_out(port, SCSCR, regs->scscr);
3609 	if (sci_getreg(port, SCFCR)->size)
3610 		sci_serial_out(port, SCFCR, regs->scfcr);
3611 	if (sci_getreg(port, SCSPTR)->size)
3612 		sci_serial_out(port, SCSPTR, regs->scsptr);
3613 	if (sci_getreg(port, SCBRR)->size)
3614 		sci_serial_out(port, SCBRR, regs->scbrr);
3615 	if (sci_getreg(port, HSSRR)->size)
3616 		sci_serial_out(port, HSSRR, regs->hssrr);
3617 	if (sci_getreg(port, SCPCR)->size)
3618 		sci_serial_out(port, SCPCR, regs->scpcr);
3619 	if (sci_getreg(port, SCPDR)->size)
3620 		sci_serial_out(port, SCPDR, regs->scpdr);
3621 	if (sci_getreg(port, SEMR)->size)
3622 		sci_serial_out(port, SEMR, regs->semr);
3623 }
3624 
sci_suspend(struct device * dev)3625 static __maybe_unused int sci_suspend(struct device *dev)
3626 {
3627 	struct sci_port *sport = dev_get_drvdata(dev);
3628 
3629 	if (sport) {
3630 		uart_suspend_port(&sci_uart_driver, &sport->port);
3631 
3632 		if (!console_suspend_enabled && uart_console(&sport->port))
3633 			sci_console_save(sport);
3634 		else
3635 			return reset_control_assert(sport->rstc);
3636 	}
3637 
3638 	return 0;
3639 }
3640 
sci_resume(struct device * dev)3641 static __maybe_unused int sci_resume(struct device *dev)
3642 {
3643 	struct sci_port *sport = dev_get_drvdata(dev);
3644 
3645 	if (sport) {
3646 		if (!console_suspend_enabled && uart_console(&sport->port)) {
3647 			sci_console_restore(sport);
3648 		} else {
3649 			int ret = reset_control_deassert(sport->rstc);
3650 
3651 			if (ret)
3652 				return ret;
3653 		}
3654 
3655 		uart_resume_port(&sci_uart_driver, &sport->port);
3656 	}
3657 
3658 	return 0;
3659 }
3660 
3661 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3662 
3663 static struct platform_driver sci_driver = {
3664 	.probe		= sci_probe,
3665 	.remove_new	= sci_remove,
3666 	.driver		= {
3667 		.name	= "sh-sci",
3668 		.pm	= &sci_dev_pm_ops,
3669 		.of_match_table = of_match_ptr(of_sci_match),
3670 	},
3671 };
3672 
sci_init(void)3673 static int __init sci_init(void)
3674 {
3675 	pr_info("%s\n", banner);
3676 
3677 	return platform_driver_register(&sci_driver);
3678 }
3679 
sci_exit(void)3680 static void __exit sci_exit(void)
3681 {
3682 	platform_driver_unregister(&sci_driver);
3683 
3684 	if (sci_uart_driver.state)
3685 		uart_unregister_driver(&sci_uart_driver);
3686 }
3687 
3688 #if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3689 sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3690 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3691 #endif
3692 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3693 static struct plat_sci_port port_cfg;
3694 
early_console_exit(struct console * co)3695 static int early_console_exit(struct console *co)
3696 {
3697 	struct sci_port *sci_port = &sci_ports[0];
3698 
3699 	/*
3700 	 * Clean the slot used by earlycon. A new SCI device might
3701 	 * map to this slot.
3702 	 */
3703 	if (!sci_uart_earlycon_dev_probing) {
3704 		memset(sci_port, 0, sizeof(*sci_port));
3705 		sci_uart_earlycon = false;
3706 	}
3707 
3708 	return 0;
3709 }
3710 
early_console_setup(struct earlycon_device * device,int type)3711 static int __init early_console_setup(struct earlycon_device *device,
3712 				      int type)
3713 {
3714 	if (!device->port.membase)
3715 		return -ENODEV;
3716 
3717 	device->port.type = type;
3718 	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3719 	port_cfg.type = type;
3720 	sci_ports[0].cfg = &port_cfg;
3721 	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3722 	sci_uart_earlycon = true;
3723 	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3724 	sci_serial_out(&sci_ports[0].port, SCSCR,
3725 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3726 
3727 	device->con->write = serial_console_write;
3728 	device->con->exit = early_console_exit;
3729 
3730 	return 0;
3731 }
sci_early_console_setup(struct earlycon_device * device,const char * opt)3732 static int __init sci_early_console_setup(struct earlycon_device *device,
3733 					  const char *opt)
3734 {
3735 	return early_console_setup(device, PORT_SCI);
3736 }
scif_early_console_setup(struct earlycon_device * device,const char * opt)3737 static int __init scif_early_console_setup(struct earlycon_device *device,
3738 					  const char *opt)
3739 {
3740 	return early_console_setup(device, PORT_SCIF);
3741 }
rzscifa_early_console_setup(struct earlycon_device * device,const char * opt)3742 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3743 					  const char *opt)
3744 {
3745 	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3746 	return early_console_setup(device, PORT_SCIF);
3747 }
3748 
rzv2hscif_early_console_setup(struct earlycon_device * device,const char * opt)3749 static int __init rzv2hscif_early_console_setup(struct earlycon_device *device,
3750 						const char *opt)
3751 {
3752 	port_cfg.regtype = SCIx_RZV2H_SCIF_REGTYPE;
3753 	return early_console_setup(device, PORT_SCIF);
3754 }
3755 
scifa_early_console_setup(struct earlycon_device * device,const char * opt)3756 static int __init scifa_early_console_setup(struct earlycon_device *device,
3757 					  const char *opt)
3758 {
3759 	return early_console_setup(device, PORT_SCIFA);
3760 }
scifb_early_console_setup(struct earlycon_device * device,const char * opt)3761 static int __init scifb_early_console_setup(struct earlycon_device *device,
3762 					  const char *opt)
3763 {
3764 	return early_console_setup(device, PORT_SCIFB);
3765 }
hscif_early_console_setup(struct earlycon_device * device,const char * opt)3766 static int __init hscif_early_console_setup(struct earlycon_device *device,
3767 					  const char *opt)
3768 {
3769 	return early_console_setup(device, PORT_HSCIF);
3770 }
3771 
3772 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3773 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3774 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3775 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3776 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a09g057", rzv2hscif_early_console_setup);
3777 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3778 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3779 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3780 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3781 
3782 module_init(sci_init);
3783 module_exit(sci_exit);
3784 
3785 MODULE_LICENSE("GPL");
3786 MODULE_ALIAS("platform:sh-sci");
3787 MODULE_AUTHOR("Paul Mundt");
3788 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
3789