xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision 81d67439)
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/platform_device.h>
23 #include <linux/pm_runtime.h>
24 
25 #include <linux/spi/sh_msiof.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/spi_bitbang.h>
28 
29 #include <asm/unaligned.h>
30 
31 struct sh_msiof_spi_priv {
32 	struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */
33 	void __iomem *mapbase;
34 	struct clk *clk;
35 	struct platform_device *pdev;
36 	struct sh_msiof_spi_info *info;
37 	struct completion done;
38 	unsigned long flags;
39 	int tx_fifo_size;
40 	int rx_fifo_size;
41 };
42 
43 #define TMDR1	0x00
44 #define TMDR2	0x04
45 #define TMDR3	0x08
46 #define RMDR1	0x10
47 #define RMDR2	0x14
48 #define RMDR3	0x18
49 #define TSCR	0x20
50 #define RSCR	0x22
51 #define CTR	0x28
52 #define FCTR	0x30
53 #define STR	0x40
54 #define IER	0x44
55 #define TDR1	0x48
56 #define TDR2	0x4c
57 #define TFDR	0x50
58 #define RDR1	0x58
59 #define RDR2	0x5c
60 #define RFDR	0x60
61 
62 #define CTR_TSCKE (1 << 15)
63 #define CTR_TFSE  (1 << 14)
64 #define CTR_TXE   (1 << 9)
65 #define CTR_RXE   (1 << 8)
66 
67 #define STR_TEOF  (1 << 23)
68 #define STR_REOF  (1 << 7)
69 
70 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
71 {
72 	switch (reg_offs) {
73 	case TSCR:
74 	case RSCR:
75 		return ioread16(p->mapbase + reg_offs);
76 	default:
77 		return ioread32(p->mapbase + reg_offs);
78 	}
79 }
80 
81 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
82 			   u32 value)
83 {
84 	switch (reg_offs) {
85 	case TSCR:
86 	case RSCR:
87 		iowrite16(value, p->mapbase + reg_offs);
88 		break;
89 	default:
90 		iowrite32(value, p->mapbase + reg_offs);
91 		break;
92 	}
93 }
94 
95 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
96 				    u32 clr, u32 set)
97 {
98 	u32 mask = clr | set;
99 	u32 data;
100 	int k;
101 
102 	data = sh_msiof_read(p, CTR);
103 	data &= ~clr;
104 	data |= set;
105 	sh_msiof_write(p, CTR, data);
106 
107 	for (k = 100; k > 0; k--) {
108 		if ((sh_msiof_read(p, CTR) & mask) == set)
109 			break;
110 
111 		udelay(10);
112 	}
113 
114 	return k > 0 ? 0 : -ETIMEDOUT;
115 }
116 
117 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
118 {
119 	struct sh_msiof_spi_priv *p = data;
120 
121 	/* just disable the interrupt and wake up */
122 	sh_msiof_write(p, IER, 0);
123 	complete(&p->done);
124 
125 	return IRQ_HANDLED;
126 }
127 
128 static struct {
129 	unsigned short div;
130 	unsigned short scr;
131 } const sh_msiof_spi_clk_table[] = {
132 	{ 1, 0x0007 },
133 	{ 2, 0x0000 },
134 	{ 4, 0x0001 },
135 	{ 8, 0x0002 },
136 	{ 16, 0x0003 },
137 	{ 32, 0x0004 },
138 	{ 64, 0x1f00 },
139 	{ 128, 0x1f01 },
140 	{ 256, 0x1f02 },
141 	{ 512, 0x1f03 },
142 	{ 1024, 0x1f04 },
143 };
144 
145 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
146 				      unsigned long parent_rate,
147 				      unsigned long spi_hz)
148 {
149 	unsigned long div = 1024;
150 	size_t k;
151 
152 	if (!WARN_ON(!spi_hz || !parent_rate))
153 		div = parent_rate / spi_hz;
154 
155 	/* TODO: make more fine grained */
156 
157 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
158 		if (sh_msiof_spi_clk_table[k].div >= div)
159 			break;
160 	}
161 
162 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);
163 
164 	sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
165 	sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
166 }
167 
168 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
169 				      u32 cpol, u32 cpha,
170 				      u32 tx_hi_z, u32 lsb_first)
171 {
172 	u32 tmp;
173 	int edge;
174 
175 	/*
176 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
177 	 *    0    0         10     10    1    1
178 	 *    0    1         10     10    0    0
179 	 *    1    0         11     11    0    0
180 	 *    1    1         11     11    1    1
181 	 */
182 	sh_msiof_write(p, FCTR, 0);
183 	sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
184 	sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));
185 
186 	tmp = 0xa0000000;
187 	tmp |= cpol << 30; /* TSCKIZ */
188 	tmp |= cpol << 28; /* RSCKIZ */
189 
190 	edge = cpol ^ !cpha;
191 
192 	tmp |= edge << 27; /* TEDG */
193 	tmp |= edge << 26; /* REDG */
194 	tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
195 	sh_msiof_write(p, CTR, tmp);
196 }
197 
198 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
199 				       const void *tx_buf, void *rx_buf,
200 				       u32 bits, u32 words)
201 {
202 	u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);
203 
204 	if (tx_buf)
205 		sh_msiof_write(p, TMDR2, dr2);
206 	else
207 		sh_msiof_write(p, TMDR2, dr2 | 1);
208 
209 	if (rx_buf)
210 		sh_msiof_write(p, RMDR2, dr2);
211 
212 	sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
213 }
214 
215 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
216 {
217 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
218 }
219 
220 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
221 				      const void *tx_buf, int words, int fs)
222 {
223 	const u8 *buf_8 = tx_buf;
224 	int k;
225 
226 	for (k = 0; k < words; k++)
227 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
228 }
229 
230 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
231 				       const void *tx_buf, int words, int fs)
232 {
233 	const u16 *buf_16 = tx_buf;
234 	int k;
235 
236 	for (k = 0; k < words; k++)
237 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
238 }
239 
240 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
241 					const void *tx_buf, int words, int fs)
242 {
243 	const u16 *buf_16 = tx_buf;
244 	int k;
245 
246 	for (k = 0; k < words; k++)
247 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
248 }
249 
250 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
251 				       const void *tx_buf, int words, int fs)
252 {
253 	const u32 *buf_32 = tx_buf;
254 	int k;
255 
256 	for (k = 0; k < words; k++)
257 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
258 }
259 
260 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
261 					const void *tx_buf, int words, int fs)
262 {
263 	const u32 *buf_32 = tx_buf;
264 	int k;
265 
266 	for (k = 0; k < words; k++)
267 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
268 }
269 
270 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
271 					const void *tx_buf, int words, int fs)
272 {
273 	const u32 *buf_32 = tx_buf;
274 	int k;
275 
276 	for (k = 0; k < words; k++)
277 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
278 }
279 
280 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
281 					 const void *tx_buf, int words, int fs)
282 {
283 	const u32 *buf_32 = tx_buf;
284 	int k;
285 
286 	for (k = 0; k < words; k++)
287 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
288 }
289 
290 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
291 				     void *rx_buf, int words, int fs)
292 {
293 	u8 *buf_8 = rx_buf;
294 	int k;
295 
296 	for (k = 0; k < words; k++)
297 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
298 }
299 
300 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
301 				      void *rx_buf, int words, int fs)
302 {
303 	u16 *buf_16 = rx_buf;
304 	int k;
305 
306 	for (k = 0; k < words; k++)
307 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
308 }
309 
310 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
311 				       void *rx_buf, int words, int fs)
312 {
313 	u16 *buf_16 = rx_buf;
314 	int k;
315 
316 	for (k = 0; k < words; k++)
317 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
318 }
319 
320 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
321 				      void *rx_buf, int words, int fs)
322 {
323 	u32 *buf_32 = rx_buf;
324 	int k;
325 
326 	for (k = 0; k < words; k++)
327 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
328 }
329 
330 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
331 				       void *rx_buf, int words, int fs)
332 {
333 	u32 *buf_32 = rx_buf;
334 	int k;
335 
336 	for (k = 0; k < words; k++)
337 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
338 }
339 
340 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
341 				       void *rx_buf, int words, int fs)
342 {
343 	u32 *buf_32 = rx_buf;
344 	int k;
345 
346 	for (k = 0; k < words; k++)
347 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
348 }
349 
350 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
351 				       void *rx_buf, int words, int fs)
352 {
353 	u32 *buf_32 = rx_buf;
354 	int k;
355 
356 	for (k = 0; k < words; k++)
357 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
358 }
359 
360 static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
361 {
362 	int bits;
363 
364 	bits = t ? t->bits_per_word : 0;
365 	if (!bits)
366 		bits = spi->bits_per_word;
367 	return bits;
368 }
369 
370 static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
371 				     struct spi_transfer *t)
372 {
373 	unsigned long hz;
374 
375 	hz = t ? t->speed_hz : 0;
376 	if (!hz)
377 		hz = spi->max_speed_hz;
378 	return hz;
379 }
380 
381 static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
382 				       struct spi_transfer *t)
383 {
384 	int bits;
385 
386 	/* noting to check hz values against since parent clock is disabled */
387 
388 	bits = sh_msiof_spi_bits(spi, t);
389 	if (bits < 8)
390 		return -EINVAL;
391 	if (bits > 32)
392 		return -EINVAL;
393 
394 	return spi_bitbang_setup_transfer(spi, t);
395 }
396 
397 static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
398 {
399 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
400 	int value;
401 
402 	/* chip select is active low unless SPI_CS_HIGH is set */
403 	if (spi->mode & SPI_CS_HIGH)
404 		value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
405 	else
406 		value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
407 
408 	if (is_on == BITBANG_CS_ACTIVE) {
409 		if (!test_and_set_bit(0, &p->flags)) {
410 			pm_runtime_get_sync(&p->pdev->dev);
411 			clk_enable(p->clk);
412 		}
413 
414 		/* Configure pins before asserting CS */
415 		sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
416 					  !!(spi->mode & SPI_CPHA),
417 					  !!(spi->mode & SPI_3WIRE),
418 					  !!(spi->mode & SPI_LSB_FIRST));
419 	}
420 
421 	/* use spi->controller data for CS (same strategy as spi_gpio) */
422 	gpio_set_value((unsigned)spi->controller_data, value);
423 
424 	if (is_on == BITBANG_CS_INACTIVE) {
425 		if (test_and_clear_bit(0, &p->flags)) {
426 			clk_disable(p->clk);
427 			pm_runtime_put(&p->pdev->dev);
428 		}
429 	}
430 }
431 
432 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
433 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
434 						  const void *, int, int),
435 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
436 						  void *, int, int),
437 				  const void *tx_buf, void *rx_buf,
438 				  int words, int bits)
439 {
440 	int fifo_shift;
441 	int ret;
442 
443 	/* limit maximum word transfer to rx/tx fifo size */
444 	if (tx_buf)
445 		words = min_t(int, words, p->tx_fifo_size);
446 	if (rx_buf)
447 		words = min_t(int, words, p->rx_fifo_size);
448 
449 	/* the fifo contents need shifting */
450 	fifo_shift = 32 - bits;
451 
452 	/* setup msiof transfer mode registers */
453 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
454 
455 	/* write tx fifo */
456 	if (tx_buf)
457 		tx_fifo(p, tx_buf, words, fifo_shift);
458 
459 	/* setup clock and rx/tx signals */
460 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
461 	if (rx_buf)
462 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
463 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
464 
465 	/* start by setting frame bit */
466 	INIT_COMPLETION(p->done);
467 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
468 	if (ret) {
469 		dev_err(&p->pdev->dev, "failed to start hardware\n");
470 		goto err;
471 	}
472 
473 	/* wait for tx fifo to be emptied / rx fifo to be filled */
474 	wait_for_completion(&p->done);
475 
476 	/* read rx fifo */
477 	if (rx_buf)
478 		rx_fifo(p, rx_buf, words, fifo_shift);
479 
480 	/* clear status bits */
481 	sh_msiof_reset_str(p);
482 
483 	/* shut down frame, tx/tx and clock signals */
484 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
485 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
486 	if (rx_buf)
487 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
488 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
489 	if (ret) {
490 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
491 		goto err;
492 	}
493 
494 	return words;
495 
496  err:
497 	sh_msiof_write(p, IER, 0);
498 	return ret;
499 }
500 
501 static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
502 {
503 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
504 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
505 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
506 	int bits;
507 	int bytes_per_word;
508 	int bytes_done;
509 	int words;
510 	int n;
511 	bool swab;
512 
513 	bits = sh_msiof_spi_bits(spi, t);
514 
515 	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
516 		bits = 32;
517 		swab = true;
518 	} else {
519 		swab = false;
520 	}
521 
522 	/* setup bytes per word and fifo read/write functions */
523 	if (bits <= 8) {
524 		bytes_per_word = 1;
525 		tx_fifo = sh_msiof_spi_write_fifo_8;
526 		rx_fifo = sh_msiof_spi_read_fifo_8;
527 	} else if (bits <= 16) {
528 		bytes_per_word = 2;
529 		if ((unsigned long)t->tx_buf & 0x01)
530 			tx_fifo = sh_msiof_spi_write_fifo_16u;
531 		else
532 			tx_fifo = sh_msiof_spi_write_fifo_16;
533 
534 		if ((unsigned long)t->rx_buf & 0x01)
535 			rx_fifo = sh_msiof_spi_read_fifo_16u;
536 		else
537 			rx_fifo = sh_msiof_spi_read_fifo_16;
538 	} else if (swab) {
539 		bytes_per_word = 4;
540 		if ((unsigned long)t->tx_buf & 0x03)
541 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
542 		else
543 			tx_fifo = sh_msiof_spi_write_fifo_s32;
544 
545 		if ((unsigned long)t->rx_buf & 0x03)
546 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
547 		else
548 			rx_fifo = sh_msiof_spi_read_fifo_s32;
549 	} else {
550 		bytes_per_word = 4;
551 		if ((unsigned long)t->tx_buf & 0x03)
552 			tx_fifo = sh_msiof_spi_write_fifo_32u;
553 		else
554 			tx_fifo = sh_msiof_spi_write_fifo_32;
555 
556 		if ((unsigned long)t->rx_buf & 0x03)
557 			rx_fifo = sh_msiof_spi_read_fifo_32u;
558 		else
559 			rx_fifo = sh_msiof_spi_read_fifo_32;
560 	}
561 
562 	/* setup clocks (clock already enabled in chipselect()) */
563 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
564 				  sh_msiof_spi_hz(spi, t));
565 
566 	/* transfer in fifo sized chunks */
567 	words = t->len / bytes_per_word;
568 	bytes_done = 0;
569 
570 	while (bytes_done < t->len) {
571 		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
572 		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
573 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
574 					   tx_buf,
575 					   rx_buf,
576 					   words, bits);
577 		if (n < 0)
578 			break;
579 
580 		bytes_done += n * bytes_per_word;
581 		words -= n;
582 	}
583 
584 	return bytes_done;
585 }
586 
587 static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
588 				  u32 word, u8 bits)
589 {
590 	BUG(); /* unused but needed by bitbang code */
591 	return 0;
592 }
593 
594 static int sh_msiof_spi_probe(struct platform_device *pdev)
595 {
596 	struct resource	*r;
597 	struct spi_master *master;
598 	struct sh_msiof_spi_priv *p;
599 	char clk_name[16];
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 	snprintf(clk_name, sizeof(clk_name), "msiof%d", pdev->id);
617 	p->clk = clk_get(&pdev->dev, clk_name);
618 	if (IS_ERR(p->clk)) {
619 		dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
620 		ret = PTR_ERR(p->clk);
621 		goto err1;
622 	}
623 
624 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
625 	i = platform_get_irq(pdev, 0);
626 	if (!r || i < 0) {
627 		dev_err(&pdev->dev, "cannot get platform resources\n");
628 		ret = -ENOENT;
629 		goto err2;
630 	}
631 	p->mapbase = ioremap_nocache(r->start, resource_size(r));
632 	if (!p->mapbase) {
633 		dev_err(&pdev->dev, "unable to ioremap\n");
634 		ret = -ENXIO;
635 		goto err2;
636 	}
637 
638 	ret = request_irq(i, sh_msiof_spi_irq, IRQF_DISABLED,
639 			  dev_name(&pdev->dev), p);
640 	if (ret) {
641 		dev_err(&pdev->dev, "unable to request irq\n");
642 		goto err3;
643 	}
644 
645 	p->pdev = pdev;
646 	pm_runtime_enable(&pdev->dev);
647 
648 	/* The standard version of MSIOF use 64 word FIFOs */
649 	p->tx_fifo_size = 64;
650 	p->rx_fifo_size = 64;
651 
652 	/* Platform data may override FIFO sizes */
653 	if (p->info->tx_fifo_override)
654 		p->tx_fifo_size = p->info->tx_fifo_override;
655 	if (p->info->rx_fifo_override)
656 		p->rx_fifo_size = p->info->rx_fifo_override;
657 
658 	/* init master and bitbang code */
659 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
660 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
661 	master->flags = 0;
662 	master->bus_num = pdev->id;
663 	master->num_chipselect = p->info->num_chipselect;
664 	master->setup = spi_bitbang_setup;
665 	master->cleanup = spi_bitbang_cleanup;
666 
667 	p->bitbang.master = master;
668 	p->bitbang.chipselect = sh_msiof_spi_chipselect;
669 	p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
670 	p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
671 	p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
672 	p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
673 	p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
674 	p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
675 
676 	ret = spi_bitbang_start(&p->bitbang);
677 	if (ret == 0)
678 		return 0;
679 
680 	pm_runtime_disable(&pdev->dev);
681  err3:
682 	iounmap(p->mapbase);
683  err2:
684 	clk_put(p->clk);
685  err1:
686 	spi_master_put(master);
687  err0:
688 	return ret;
689 }
690 
691 static int sh_msiof_spi_remove(struct platform_device *pdev)
692 {
693 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
694 	int ret;
695 
696 	ret = spi_bitbang_stop(&p->bitbang);
697 	if (!ret) {
698 		pm_runtime_disable(&pdev->dev);
699 		free_irq(platform_get_irq(pdev, 0), p);
700 		iounmap(p->mapbase);
701 		clk_put(p->clk);
702 		spi_master_put(p->bitbang.master);
703 	}
704 	return ret;
705 }
706 
707 static int sh_msiof_spi_runtime_nop(struct device *dev)
708 {
709 	/* Runtime PM callback shared between ->runtime_suspend()
710 	 * and ->runtime_resume(). Simply returns success.
711 	 *
712 	 * This driver re-initializes all registers after
713 	 * pm_runtime_get_sync() anyway so there is no need
714 	 * to save and restore registers here.
715 	 */
716 	return 0;
717 }
718 
719 static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = {
720 	.runtime_suspend = sh_msiof_spi_runtime_nop,
721 	.runtime_resume = sh_msiof_spi_runtime_nop,
722 };
723 
724 static struct platform_driver sh_msiof_spi_drv = {
725 	.probe		= sh_msiof_spi_probe,
726 	.remove		= sh_msiof_spi_remove,
727 	.driver		= {
728 		.name		= "spi_sh_msiof",
729 		.owner		= THIS_MODULE,
730 		.pm		= &sh_msiof_spi_dev_pm_ops,
731 	},
732 };
733 
734 static int __init sh_msiof_spi_init(void)
735 {
736 	return platform_driver_register(&sh_msiof_spi_drv);
737 }
738 module_init(sh_msiof_spi_init);
739 
740 static void __exit sh_msiof_spi_exit(void)
741 {
742 	platform_driver_unregister(&sh_msiof_spi_drv);
743 }
744 module_exit(sh_msiof_spi_exit);
745 
746 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
747 MODULE_AUTHOR("Magnus Damm");
748 MODULE_LICENSE("GPL v2");
749 MODULE_ALIAS("platform:spi_sh_msiof");
750