xref: /linux/drivers/spi/spi-sh-msiof.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * SuperH MSIOF SPI Master Interface
3  *
4  * Copyright (c) 2009 Magnus Damm
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  */
11 
12 #include <linux/bitmap.h>
13 #include <linux/clk.h>
14 #include <linux/completion.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_runtime.h>
25 
26 #include <linux/spi/sh_msiof.h>
27 #include <linux/spi/spi.h>
28 #include <linux/spi/spi_bitbang.h>
29 
30 #include <asm/unaligned.h>
31 
32 struct sh_msiof_spi_priv {
33 	struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */
34 	void __iomem *mapbase;
35 	struct clk *clk;
36 	struct platform_device *pdev;
37 	struct sh_msiof_spi_info *info;
38 	struct completion done;
39 	unsigned long flags;
40 	int tx_fifo_size;
41 	int rx_fifo_size;
42 };
43 
44 #define TMDR1	0x00
45 #define TMDR2	0x04
46 #define TMDR3	0x08
47 #define RMDR1	0x10
48 #define RMDR2	0x14
49 #define RMDR3	0x18
50 #define TSCR	0x20
51 #define RSCR	0x22
52 #define CTR	0x28
53 #define FCTR	0x30
54 #define STR	0x40
55 #define IER	0x44
56 #define TDR1	0x48
57 #define TDR2	0x4c
58 #define TFDR	0x50
59 #define RDR1	0x58
60 #define RDR2	0x5c
61 #define RFDR	0x60
62 
63 #define CTR_TSCKE (1 << 15)
64 #define CTR_TFSE  (1 << 14)
65 #define CTR_TXE   (1 << 9)
66 #define CTR_RXE   (1 << 8)
67 
68 #define STR_TEOF  (1 << 23)
69 #define STR_REOF  (1 << 7)
70 
71 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
72 {
73 	switch (reg_offs) {
74 	case TSCR:
75 	case RSCR:
76 		return ioread16(p->mapbase + reg_offs);
77 	default:
78 		return ioread32(p->mapbase + reg_offs);
79 	}
80 }
81 
82 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
83 			   u32 value)
84 {
85 	switch (reg_offs) {
86 	case TSCR:
87 	case RSCR:
88 		iowrite16(value, p->mapbase + reg_offs);
89 		break;
90 	default:
91 		iowrite32(value, p->mapbase + reg_offs);
92 		break;
93 	}
94 }
95 
96 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
97 				    u32 clr, u32 set)
98 {
99 	u32 mask = clr | set;
100 	u32 data;
101 	int k;
102 
103 	data = sh_msiof_read(p, CTR);
104 	data &= ~clr;
105 	data |= set;
106 	sh_msiof_write(p, CTR, data);
107 
108 	for (k = 100; k > 0; k--) {
109 		if ((sh_msiof_read(p, CTR) & mask) == set)
110 			break;
111 
112 		udelay(10);
113 	}
114 
115 	return k > 0 ? 0 : -ETIMEDOUT;
116 }
117 
118 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
119 {
120 	struct sh_msiof_spi_priv *p = data;
121 
122 	/* just disable the interrupt and wake up */
123 	sh_msiof_write(p, IER, 0);
124 	complete(&p->done);
125 
126 	return IRQ_HANDLED;
127 }
128 
129 static struct {
130 	unsigned short div;
131 	unsigned short scr;
132 } const sh_msiof_spi_clk_table[] = {
133 	{ 1, 0x0007 },
134 	{ 2, 0x0000 },
135 	{ 4, 0x0001 },
136 	{ 8, 0x0002 },
137 	{ 16, 0x0003 },
138 	{ 32, 0x0004 },
139 	{ 64, 0x1f00 },
140 	{ 128, 0x1f01 },
141 	{ 256, 0x1f02 },
142 	{ 512, 0x1f03 },
143 	{ 1024, 0x1f04 },
144 };
145 
146 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
147 				      unsigned long parent_rate,
148 				      unsigned long spi_hz)
149 {
150 	unsigned long div = 1024;
151 	size_t k;
152 
153 	if (!WARN_ON(!spi_hz || !parent_rate))
154 		div = parent_rate / spi_hz;
155 
156 	/* TODO: make more fine grained */
157 
158 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
159 		if (sh_msiof_spi_clk_table[k].div >= div)
160 			break;
161 	}
162 
163 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);
164 
165 	sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
166 	sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
167 }
168 
169 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
170 				      u32 cpol, u32 cpha,
171 				      u32 tx_hi_z, u32 lsb_first)
172 {
173 	u32 tmp;
174 	int edge;
175 
176 	/*
177 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
178 	 *    0    0         10     10    1    1
179 	 *    0    1         10     10    0    0
180 	 *    1    0         11     11    0    0
181 	 *    1    1         11     11    1    1
182 	 */
183 	sh_msiof_write(p, FCTR, 0);
184 	sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
185 	sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));
186 
187 	tmp = 0xa0000000;
188 	tmp |= cpol << 30; /* TSCKIZ */
189 	tmp |= cpol << 28; /* RSCKIZ */
190 
191 	edge = cpol ^ !cpha;
192 
193 	tmp |= edge << 27; /* TEDG */
194 	tmp |= edge << 26; /* REDG */
195 	tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
196 	sh_msiof_write(p, CTR, tmp);
197 }
198 
199 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
200 				       const void *tx_buf, void *rx_buf,
201 				       u32 bits, u32 words)
202 {
203 	u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);
204 
205 	if (tx_buf)
206 		sh_msiof_write(p, TMDR2, dr2);
207 	else
208 		sh_msiof_write(p, TMDR2, dr2 | 1);
209 
210 	if (rx_buf)
211 		sh_msiof_write(p, RMDR2, dr2);
212 
213 	sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
214 }
215 
216 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
217 {
218 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
219 }
220 
221 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
222 				      const void *tx_buf, int words, int fs)
223 {
224 	const u8 *buf_8 = tx_buf;
225 	int k;
226 
227 	for (k = 0; k < words; k++)
228 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
229 }
230 
231 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
232 				       const void *tx_buf, int words, int fs)
233 {
234 	const u16 *buf_16 = tx_buf;
235 	int k;
236 
237 	for (k = 0; k < words; k++)
238 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
239 }
240 
241 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
242 					const void *tx_buf, int words, int fs)
243 {
244 	const u16 *buf_16 = tx_buf;
245 	int k;
246 
247 	for (k = 0; k < words; k++)
248 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
249 }
250 
251 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
252 				       const void *tx_buf, int words, int fs)
253 {
254 	const u32 *buf_32 = tx_buf;
255 	int k;
256 
257 	for (k = 0; k < words; k++)
258 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
259 }
260 
261 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
262 					const void *tx_buf, int words, int fs)
263 {
264 	const u32 *buf_32 = tx_buf;
265 	int k;
266 
267 	for (k = 0; k < words; k++)
268 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
269 }
270 
271 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
272 					const void *tx_buf, int words, int fs)
273 {
274 	const u32 *buf_32 = tx_buf;
275 	int k;
276 
277 	for (k = 0; k < words; k++)
278 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
279 }
280 
281 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
282 					 const void *tx_buf, int words, int fs)
283 {
284 	const u32 *buf_32 = tx_buf;
285 	int k;
286 
287 	for (k = 0; k < words; k++)
288 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
289 }
290 
291 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
292 				     void *rx_buf, int words, int fs)
293 {
294 	u8 *buf_8 = rx_buf;
295 	int k;
296 
297 	for (k = 0; k < words; k++)
298 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
299 }
300 
301 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
302 				      void *rx_buf, int words, int fs)
303 {
304 	u16 *buf_16 = rx_buf;
305 	int k;
306 
307 	for (k = 0; k < words; k++)
308 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
309 }
310 
311 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
312 				       void *rx_buf, int words, int fs)
313 {
314 	u16 *buf_16 = rx_buf;
315 	int k;
316 
317 	for (k = 0; k < words; k++)
318 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
319 }
320 
321 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
322 				      void *rx_buf, int words, int fs)
323 {
324 	u32 *buf_32 = rx_buf;
325 	int k;
326 
327 	for (k = 0; k < words; k++)
328 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
329 }
330 
331 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
332 				       void *rx_buf, int words, int fs)
333 {
334 	u32 *buf_32 = rx_buf;
335 	int k;
336 
337 	for (k = 0; k < words; k++)
338 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
339 }
340 
341 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
342 				       void *rx_buf, int words, int fs)
343 {
344 	u32 *buf_32 = rx_buf;
345 	int k;
346 
347 	for (k = 0; k < words; k++)
348 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
349 }
350 
351 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
352 				       void *rx_buf, int words, int fs)
353 {
354 	u32 *buf_32 = rx_buf;
355 	int k;
356 
357 	for (k = 0; k < words; k++)
358 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
359 }
360 
361 static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
362 {
363 	int bits;
364 
365 	bits = t ? t->bits_per_word : 0;
366 	if (!bits)
367 		bits = spi->bits_per_word;
368 	return bits;
369 }
370 
371 static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
372 				     struct spi_transfer *t)
373 {
374 	unsigned long hz;
375 
376 	hz = t ? t->speed_hz : 0;
377 	if (!hz)
378 		hz = spi->max_speed_hz;
379 	return hz;
380 }
381 
382 static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
383 				       struct spi_transfer *t)
384 {
385 	int bits;
386 
387 	/* noting to check hz values against since parent clock is disabled */
388 
389 	bits = sh_msiof_spi_bits(spi, t);
390 	if (bits < 8)
391 		return -EINVAL;
392 	if (bits > 32)
393 		return -EINVAL;
394 
395 	return spi_bitbang_setup_transfer(spi, t);
396 }
397 
398 static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
399 {
400 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
401 	int value;
402 
403 	/* chip select is active low unless SPI_CS_HIGH is set */
404 	if (spi->mode & SPI_CS_HIGH)
405 		value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
406 	else
407 		value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
408 
409 	if (is_on == BITBANG_CS_ACTIVE) {
410 		if (!test_and_set_bit(0, &p->flags)) {
411 			pm_runtime_get_sync(&p->pdev->dev);
412 			clk_enable(p->clk);
413 		}
414 
415 		/* Configure pins before asserting CS */
416 		sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
417 					  !!(spi->mode & SPI_CPHA),
418 					  !!(spi->mode & SPI_3WIRE),
419 					  !!(spi->mode & SPI_LSB_FIRST));
420 	}
421 
422 	/* use spi->controller data for CS (same strategy as spi_gpio) */
423 	gpio_set_value((unsigned)spi->controller_data, value);
424 
425 	if (is_on == BITBANG_CS_INACTIVE) {
426 		if (test_and_clear_bit(0, &p->flags)) {
427 			clk_disable(p->clk);
428 			pm_runtime_put(&p->pdev->dev);
429 		}
430 	}
431 }
432 
433 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
434 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
435 						  const void *, int, int),
436 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
437 						  void *, int, int),
438 				  const void *tx_buf, void *rx_buf,
439 				  int words, int bits)
440 {
441 	int fifo_shift;
442 	int ret;
443 
444 	/* limit maximum word transfer to rx/tx fifo size */
445 	if (tx_buf)
446 		words = min_t(int, words, p->tx_fifo_size);
447 	if (rx_buf)
448 		words = min_t(int, words, p->rx_fifo_size);
449 
450 	/* the fifo contents need shifting */
451 	fifo_shift = 32 - bits;
452 
453 	/* setup msiof transfer mode registers */
454 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
455 
456 	/* write tx fifo */
457 	if (tx_buf)
458 		tx_fifo(p, tx_buf, words, fifo_shift);
459 
460 	/* setup clock and rx/tx signals */
461 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
462 	if (rx_buf)
463 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
464 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
465 
466 	/* start by setting frame bit */
467 	INIT_COMPLETION(p->done);
468 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
469 	if (ret) {
470 		dev_err(&p->pdev->dev, "failed to start hardware\n");
471 		goto err;
472 	}
473 
474 	/* wait for tx fifo to be emptied / rx fifo to be filled */
475 	wait_for_completion(&p->done);
476 
477 	/* read rx fifo */
478 	if (rx_buf)
479 		rx_fifo(p, rx_buf, words, fifo_shift);
480 
481 	/* clear status bits */
482 	sh_msiof_reset_str(p);
483 
484 	/* shut down frame, tx/tx and clock signals */
485 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
486 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
487 	if (rx_buf)
488 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
489 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
490 	if (ret) {
491 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
492 		goto err;
493 	}
494 
495 	return words;
496 
497  err:
498 	sh_msiof_write(p, IER, 0);
499 	return ret;
500 }
501 
502 static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
503 {
504 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
505 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
506 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
507 	int bits;
508 	int bytes_per_word;
509 	int bytes_done;
510 	int words;
511 	int n;
512 	bool swab;
513 
514 	bits = sh_msiof_spi_bits(spi, t);
515 
516 	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
517 		bits = 32;
518 		swab = true;
519 	} else {
520 		swab = false;
521 	}
522 
523 	/* setup bytes per word and fifo read/write functions */
524 	if (bits <= 8) {
525 		bytes_per_word = 1;
526 		tx_fifo = sh_msiof_spi_write_fifo_8;
527 		rx_fifo = sh_msiof_spi_read_fifo_8;
528 	} else if (bits <= 16) {
529 		bytes_per_word = 2;
530 		if ((unsigned long)t->tx_buf & 0x01)
531 			tx_fifo = sh_msiof_spi_write_fifo_16u;
532 		else
533 			tx_fifo = sh_msiof_spi_write_fifo_16;
534 
535 		if ((unsigned long)t->rx_buf & 0x01)
536 			rx_fifo = sh_msiof_spi_read_fifo_16u;
537 		else
538 			rx_fifo = sh_msiof_spi_read_fifo_16;
539 	} else if (swab) {
540 		bytes_per_word = 4;
541 		if ((unsigned long)t->tx_buf & 0x03)
542 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
543 		else
544 			tx_fifo = sh_msiof_spi_write_fifo_s32;
545 
546 		if ((unsigned long)t->rx_buf & 0x03)
547 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
548 		else
549 			rx_fifo = sh_msiof_spi_read_fifo_s32;
550 	} else {
551 		bytes_per_word = 4;
552 		if ((unsigned long)t->tx_buf & 0x03)
553 			tx_fifo = sh_msiof_spi_write_fifo_32u;
554 		else
555 			tx_fifo = sh_msiof_spi_write_fifo_32;
556 
557 		if ((unsigned long)t->rx_buf & 0x03)
558 			rx_fifo = sh_msiof_spi_read_fifo_32u;
559 		else
560 			rx_fifo = sh_msiof_spi_read_fifo_32;
561 	}
562 
563 	/* setup clocks (clock already enabled in chipselect()) */
564 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
565 				  sh_msiof_spi_hz(spi, t));
566 
567 	/* transfer in fifo sized chunks */
568 	words = t->len / bytes_per_word;
569 	bytes_done = 0;
570 
571 	while (bytes_done < t->len) {
572 		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
573 		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
574 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
575 					   tx_buf,
576 					   rx_buf,
577 					   words, bits);
578 		if (n < 0)
579 			break;
580 
581 		bytes_done += n * bytes_per_word;
582 		words -= n;
583 	}
584 
585 	return bytes_done;
586 }
587 
588 static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
589 				  u32 word, u8 bits)
590 {
591 	BUG(); /* unused but needed by bitbang code */
592 	return 0;
593 }
594 
595 static int sh_msiof_spi_probe(struct platform_device *pdev)
596 {
597 	struct resource	*r;
598 	struct spi_master *master;
599 	struct sh_msiof_spi_priv *p;
600 	int i;
601 	int ret;
602 
603 	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
604 	if (master == NULL) {
605 		dev_err(&pdev->dev, "failed to allocate spi master\n");
606 		ret = -ENOMEM;
607 		goto err0;
608 	}
609 
610 	p = spi_master_get_devdata(master);
611 
612 	platform_set_drvdata(pdev, p);
613 	p->info = pdev->dev.platform_data;
614 	init_completion(&p->done);
615 
616 	p->clk = clk_get(&pdev->dev, NULL);
617 	if (IS_ERR(p->clk)) {
618 		dev_err(&pdev->dev, "cannot get clock\n");
619 		ret = PTR_ERR(p->clk);
620 		goto err1;
621 	}
622 
623 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
624 	i = platform_get_irq(pdev, 0);
625 	if (!r || i < 0) {
626 		dev_err(&pdev->dev, "cannot get platform resources\n");
627 		ret = -ENOENT;
628 		goto err2;
629 	}
630 	p->mapbase = ioremap_nocache(r->start, resource_size(r));
631 	if (!p->mapbase) {
632 		dev_err(&pdev->dev, "unable to ioremap\n");
633 		ret = -ENXIO;
634 		goto err2;
635 	}
636 
637 	ret = request_irq(i, sh_msiof_spi_irq, 0,
638 			  dev_name(&pdev->dev), p);
639 	if (ret) {
640 		dev_err(&pdev->dev, "unable to request irq\n");
641 		goto err3;
642 	}
643 
644 	p->pdev = pdev;
645 	pm_runtime_enable(&pdev->dev);
646 
647 	/* The standard version of MSIOF use 64 word FIFOs */
648 	p->tx_fifo_size = 64;
649 	p->rx_fifo_size = 64;
650 
651 	/* Platform data may override FIFO sizes */
652 	if (p->info->tx_fifo_override)
653 		p->tx_fifo_size = p->info->tx_fifo_override;
654 	if (p->info->rx_fifo_override)
655 		p->rx_fifo_size = p->info->rx_fifo_override;
656 
657 	/* init master and bitbang code */
658 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
659 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
660 	master->flags = 0;
661 	master->bus_num = pdev->id;
662 	master->num_chipselect = p->info->num_chipselect;
663 	master->setup = spi_bitbang_setup;
664 	master->cleanup = spi_bitbang_cleanup;
665 
666 	p->bitbang.master = master;
667 	p->bitbang.chipselect = sh_msiof_spi_chipselect;
668 	p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
669 	p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
670 	p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
671 	p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
672 	p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
673 	p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
674 
675 	ret = spi_bitbang_start(&p->bitbang);
676 	if (ret == 0)
677 		return 0;
678 
679 	pm_runtime_disable(&pdev->dev);
680  err3:
681 	iounmap(p->mapbase);
682  err2:
683 	clk_put(p->clk);
684  err1:
685 	spi_master_put(master);
686  err0:
687 	return ret;
688 }
689 
690 static int sh_msiof_spi_remove(struct platform_device *pdev)
691 {
692 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
693 	int ret;
694 
695 	ret = spi_bitbang_stop(&p->bitbang);
696 	if (!ret) {
697 		pm_runtime_disable(&pdev->dev);
698 		free_irq(platform_get_irq(pdev, 0), p);
699 		iounmap(p->mapbase);
700 		clk_put(p->clk);
701 		spi_master_put(p->bitbang.master);
702 	}
703 	return ret;
704 }
705 
706 static int sh_msiof_spi_runtime_nop(struct device *dev)
707 {
708 	/* Runtime PM callback shared between ->runtime_suspend()
709 	 * and ->runtime_resume(). Simply returns success.
710 	 *
711 	 * This driver re-initializes all registers after
712 	 * pm_runtime_get_sync() anyway so there is no need
713 	 * to save and restore registers here.
714 	 */
715 	return 0;
716 }
717 
718 static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = {
719 	.runtime_suspend = sh_msiof_spi_runtime_nop,
720 	.runtime_resume = sh_msiof_spi_runtime_nop,
721 };
722 
723 static struct platform_driver sh_msiof_spi_drv = {
724 	.probe		= sh_msiof_spi_probe,
725 	.remove		= sh_msiof_spi_remove,
726 	.driver		= {
727 		.name		= "spi_sh_msiof",
728 		.owner		= THIS_MODULE,
729 		.pm		= &sh_msiof_spi_dev_pm_ops,
730 	},
731 };
732 module_platform_driver(sh_msiof_spi_drv);
733 
734 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
735 MODULE_AUTHOR("Magnus Damm");
736 MODULE_LICENSE("GPL v2");
737 MODULE_ALIAS("platform:spi_sh_msiof");
738