xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision 8a10bc9d)
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/of.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26 
27 #include <linux/spi/sh_msiof.h>
28 #include <linux/spi/spi.h>
29 #include <linux/spi/spi_bitbang.h>
30 
31 #include <asm/unaligned.h>
32 
33 struct sh_msiof_spi_priv {
34 	struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */
35 	void __iomem *mapbase;
36 	struct clk *clk;
37 	struct platform_device *pdev;
38 	struct sh_msiof_spi_info *info;
39 	struct completion done;
40 	unsigned long flags;
41 	int tx_fifo_size;
42 	int rx_fifo_size;
43 };
44 
45 #define TMDR1	0x00
46 #define TMDR2	0x04
47 #define TMDR3	0x08
48 #define RMDR1	0x10
49 #define RMDR2	0x14
50 #define RMDR3	0x18
51 #define TSCR	0x20
52 #define RSCR	0x22
53 #define CTR	0x28
54 #define FCTR	0x30
55 #define STR	0x40
56 #define IER	0x44
57 #define TDR1	0x48
58 #define TDR2	0x4c
59 #define TFDR	0x50
60 #define RDR1	0x58
61 #define RDR2	0x5c
62 #define RFDR	0x60
63 
64 #define CTR_TSCKE (1 << 15)
65 #define CTR_TFSE  (1 << 14)
66 #define CTR_TXE   (1 << 9)
67 #define CTR_RXE   (1 << 8)
68 
69 #define STR_TEOF  (1 << 23)
70 #define STR_REOF  (1 << 7)
71 
72 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
73 {
74 	switch (reg_offs) {
75 	case TSCR:
76 	case RSCR:
77 		return ioread16(p->mapbase + reg_offs);
78 	default:
79 		return ioread32(p->mapbase + reg_offs);
80 	}
81 }
82 
83 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
84 			   u32 value)
85 {
86 	switch (reg_offs) {
87 	case TSCR:
88 	case RSCR:
89 		iowrite16(value, p->mapbase + reg_offs);
90 		break;
91 	default:
92 		iowrite32(value, p->mapbase + reg_offs);
93 		break;
94 	}
95 }
96 
97 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
98 				    u32 clr, u32 set)
99 {
100 	u32 mask = clr | set;
101 	u32 data;
102 	int k;
103 
104 	data = sh_msiof_read(p, CTR);
105 	data &= ~clr;
106 	data |= set;
107 	sh_msiof_write(p, CTR, data);
108 
109 	for (k = 100; k > 0; k--) {
110 		if ((sh_msiof_read(p, CTR) & mask) == set)
111 			break;
112 
113 		udelay(10);
114 	}
115 
116 	return k > 0 ? 0 : -ETIMEDOUT;
117 }
118 
119 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
120 {
121 	struct sh_msiof_spi_priv *p = data;
122 
123 	/* just disable the interrupt and wake up */
124 	sh_msiof_write(p, IER, 0);
125 	complete(&p->done);
126 
127 	return IRQ_HANDLED;
128 }
129 
130 static struct {
131 	unsigned short div;
132 	unsigned short scr;
133 } const sh_msiof_spi_clk_table[] = {
134 	{ 1, 0x0007 },
135 	{ 2, 0x0000 },
136 	{ 4, 0x0001 },
137 	{ 8, 0x0002 },
138 	{ 16, 0x0003 },
139 	{ 32, 0x0004 },
140 	{ 64, 0x1f00 },
141 	{ 128, 0x1f01 },
142 	{ 256, 0x1f02 },
143 	{ 512, 0x1f03 },
144 	{ 1024, 0x1f04 },
145 };
146 
147 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
148 				      unsigned long parent_rate,
149 				      unsigned long spi_hz)
150 {
151 	unsigned long div = 1024;
152 	size_t k;
153 
154 	if (!WARN_ON(!spi_hz || !parent_rate))
155 		div = DIV_ROUND_UP(parent_rate, spi_hz);
156 
157 	/* TODO: make more fine grained */
158 
159 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
160 		if (sh_msiof_spi_clk_table[k].div >= div)
161 			break;
162 	}
163 
164 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);
165 
166 	sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
167 	sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
168 }
169 
170 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
171 				      u32 cpol, u32 cpha,
172 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
173 {
174 	u32 tmp;
175 	int edge;
176 
177 	/*
178 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
179 	 *    0    0         10     10    1    1
180 	 *    0    1         10     10    0    0
181 	 *    1    0         11     11    0    0
182 	 *    1    1         11     11    1    1
183 	 */
184 	sh_msiof_write(p, FCTR, 0);
185 
186 	tmp = 0;
187 	tmp |= !cs_high << 25;
188 	tmp |= lsb_first << 24;
189 	sh_msiof_write(p, TMDR1, 0xe0000005 | tmp);
190 	sh_msiof_write(p, RMDR1, 0x20000005 | tmp);
191 
192 	tmp = 0xa0000000;
193 	tmp |= cpol << 30; /* TSCKIZ */
194 	tmp |= cpol << 28; /* RSCKIZ */
195 
196 	edge = cpol ^ !cpha;
197 
198 	tmp |= edge << 27; /* TEDG */
199 	tmp |= edge << 26; /* REDG */
200 	tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
201 	sh_msiof_write(p, CTR, tmp);
202 }
203 
204 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
205 				       const void *tx_buf, void *rx_buf,
206 				       u32 bits, u32 words)
207 {
208 	u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);
209 
210 	if (tx_buf)
211 		sh_msiof_write(p, TMDR2, dr2);
212 	else
213 		sh_msiof_write(p, TMDR2, dr2 | 1);
214 
215 	if (rx_buf)
216 		sh_msiof_write(p, RMDR2, dr2);
217 
218 	sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
219 }
220 
221 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
222 {
223 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
224 }
225 
226 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
227 				      const void *tx_buf, int words, int fs)
228 {
229 	const u8 *buf_8 = tx_buf;
230 	int k;
231 
232 	for (k = 0; k < words; k++)
233 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
234 }
235 
236 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
237 				       const void *tx_buf, int words, int fs)
238 {
239 	const u16 *buf_16 = tx_buf;
240 	int k;
241 
242 	for (k = 0; k < words; k++)
243 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
244 }
245 
246 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
247 					const void *tx_buf, int words, int fs)
248 {
249 	const u16 *buf_16 = tx_buf;
250 	int k;
251 
252 	for (k = 0; k < words; k++)
253 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
254 }
255 
256 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
257 				       const void *tx_buf, int words, int fs)
258 {
259 	const u32 *buf_32 = tx_buf;
260 	int k;
261 
262 	for (k = 0; k < words; k++)
263 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
264 }
265 
266 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
267 					const void *tx_buf, int words, int fs)
268 {
269 	const u32 *buf_32 = tx_buf;
270 	int k;
271 
272 	for (k = 0; k < words; k++)
273 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
274 }
275 
276 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
277 					const void *tx_buf, int words, int fs)
278 {
279 	const u32 *buf_32 = tx_buf;
280 	int k;
281 
282 	for (k = 0; k < words; k++)
283 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
284 }
285 
286 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
287 					 const void *tx_buf, int words, int fs)
288 {
289 	const u32 *buf_32 = tx_buf;
290 	int k;
291 
292 	for (k = 0; k < words; k++)
293 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
294 }
295 
296 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
297 				     void *rx_buf, int words, int fs)
298 {
299 	u8 *buf_8 = rx_buf;
300 	int k;
301 
302 	for (k = 0; k < words; k++)
303 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
304 }
305 
306 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
307 				      void *rx_buf, int words, int fs)
308 {
309 	u16 *buf_16 = rx_buf;
310 	int k;
311 
312 	for (k = 0; k < words; k++)
313 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
314 }
315 
316 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
317 				       void *rx_buf, int words, int fs)
318 {
319 	u16 *buf_16 = rx_buf;
320 	int k;
321 
322 	for (k = 0; k < words; k++)
323 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
324 }
325 
326 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
327 				      void *rx_buf, int words, int fs)
328 {
329 	u32 *buf_32 = rx_buf;
330 	int k;
331 
332 	for (k = 0; k < words; k++)
333 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
334 }
335 
336 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
337 				       void *rx_buf, int words, int fs)
338 {
339 	u32 *buf_32 = rx_buf;
340 	int k;
341 
342 	for (k = 0; k < words; k++)
343 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
344 }
345 
346 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
347 				       void *rx_buf, int words, int fs)
348 {
349 	u32 *buf_32 = rx_buf;
350 	int k;
351 
352 	for (k = 0; k < words; k++)
353 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
354 }
355 
356 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
357 				       void *rx_buf, int words, int fs)
358 {
359 	u32 *buf_32 = rx_buf;
360 	int k;
361 
362 	for (k = 0; k < words; k++)
363 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
364 }
365 
366 static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
367 {
368 	int bits;
369 
370 	bits = t ? t->bits_per_word : 0;
371 	if (!bits)
372 		bits = spi->bits_per_word;
373 	return bits;
374 }
375 
376 static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
377 				     struct spi_transfer *t)
378 {
379 	unsigned long hz;
380 
381 	hz = t ? t->speed_hz : 0;
382 	if (!hz)
383 		hz = spi->max_speed_hz;
384 	return hz;
385 }
386 
387 static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
388 				       struct spi_transfer *t)
389 {
390 	int bits;
391 
392 	/* noting to check hz values against since parent clock is disabled */
393 
394 	bits = sh_msiof_spi_bits(spi, t);
395 	if (bits < 8)
396 		return -EINVAL;
397 	if (bits > 32)
398 		return -EINVAL;
399 
400 	return spi_bitbang_setup_transfer(spi, t);
401 }
402 
403 static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
404 {
405 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
406 	int value;
407 
408 	/* chip select is active low unless SPI_CS_HIGH is set */
409 	if (spi->mode & SPI_CS_HIGH)
410 		value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
411 	else
412 		value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
413 
414 	if (is_on == BITBANG_CS_ACTIVE) {
415 		if (!test_and_set_bit(0, &p->flags)) {
416 			pm_runtime_get_sync(&p->pdev->dev);
417 			clk_enable(p->clk);
418 		}
419 
420 		/* Configure pins before asserting CS */
421 		sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
422 					  !!(spi->mode & SPI_CPHA),
423 					  !!(spi->mode & SPI_3WIRE),
424 					  !!(spi->mode & SPI_LSB_FIRST),
425 					  !!(spi->mode & SPI_CS_HIGH));
426 	}
427 
428 	/* use spi->controller data for CS (same strategy as spi_gpio) */
429 	gpio_set_value((uintptr_t)spi->controller_data, value);
430 
431 	if (is_on == BITBANG_CS_INACTIVE) {
432 		if (test_and_clear_bit(0, &p->flags)) {
433 			clk_disable(p->clk);
434 			pm_runtime_put(&p->pdev->dev);
435 		}
436 	}
437 }
438 
439 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
440 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
441 						  const void *, int, int),
442 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
443 						  void *, int, int),
444 				  const void *tx_buf, void *rx_buf,
445 				  int words, int bits)
446 {
447 	int fifo_shift;
448 	int ret;
449 
450 	/* limit maximum word transfer to rx/tx fifo size */
451 	if (tx_buf)
452 		words = min_t(int, words, p->tx_fifo_size);
453 	if (rx_buf)
454 		words = min_t(int, words, p->rx_fifo_size);
455 
456 	/* the fifo contents need shifting */
457 	fifo_shift = 32 - bits;
458 
459 	/* setup msiof transfer mode registers */
460 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
461 
462 	/* write tx fifo */
463 	if (tx_buf)
464 		tx_fifo(p, tx_buf, words, fifo_shift);
465 
466 	/* setup clock and rx/tx signals */
467 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
468 	if (rx_buf)
469 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
470 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
471 
472 	/* start by setting frame bit */
473 	reinit_completion(&p->done);
474 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
475 	if (ret) {
476 		dev_err(&p->pdev->dev, "failed to start hardware\n");
477 		goto err;
478 	}
479 
480 	/* wait for tx fifo to be emptied / rx fifo to be filled */
481 	wait_for_completion(&p->done);
482 
483 	/* read rx fifo */
484 	if (rx_buf)
485 		rx_fifo(p, rx_buf, words, fifo_shift);
486 
487 	/* clear status bits */
488 	sh_msiof_reset_str(p);
489 
490 	/* shut down frame, tx/tx and clock signals */
491 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
492 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
493 	if (rx_buf)
494 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
495 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
496 	if (ret) {
497 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
498 		goto err;
499 	}
500 
501 	return words;
502 
503  err:
504 	sh_msiof_write(p, IER, 0);
505 	return ret;
506 }
507 
508 static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
509 {
510 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
511 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
512 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
513 	int bits;
514 	int bytes_per_word;
515 	int bytes_done;
516 	int words;
517 	int n;
518 	bool swab;
519 
520 	bits = sh_msiof_spi_bits(spi, t);
521 
522 	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
523 		bits = 32;
524 		swab = true;
525 	} else {
526 		swab = false;
527 	}
528 
529 	/* setup bytes per word and fifo read/write functions */
530 	if (bits <= 8) {
531 		bytes_per_word = 1;
532 		tx_fifo = sh_msiof_spi_write_fifo_8;
533 		rx_fifo = sh_msiof_spi_read_fifo_8;
534 	} else if (bits <= 16) {
535 		bytes_per_word = 2;
536 		if ((unsigned long)t->tx_buf & 0x01)
537 			tx_fifo = sh_msiof_spi_write_fifo_16u;
538 		else
539 			tx_fifo = sh_msiof_spi_write_fifo_16;
540 
541 		if ((unsigned long)t->rx_buf & 0x01)
542 			rx_fifo = sh_msiof_spi_read_fifo_16u;
543 		else
544 			rx_fifo = sh_msiof_spi_read_fifo_16;
545 	} else if (swab) {
546 		bytes_per_word = 4;
547 		if ((unsigned long)t->tx_buf & 0x03)
548 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
549 		else
550 			tx_fifo = sh_msiof_spi_write_fifo_s32;
551 
552 		if ((unsigned long)t->rx_buf & 0x03)
553 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
554 		else
555 			rx_fifo = sh_msiof_spi_read_fifo_s32;
556 	} else {
557 		bytes_per_word = 4;
558 		if ((unsigned long)t->tx_buf & 0x03)
559 			tx_fifo = sh_msiof_spi_write_fifo_32u;
560 		else
561 			tx_fifo = sh_msiof_spi_write_fifo_32;
562 
563 		if ((unsigned long)t->rx_buf & 0x03)
564 			rx_fifo = sh_msiof_spi_read_fifo_32u;
565 		else
566 			rx_fifo = sh_msiof_spi_read_fifo_32;
567 	}
568 
569 	/* setup clocks (clock already enabled in chipselect()) */
570 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
571 				  sh_msiof_spi_hz(spi, t));
572 
573 	/* transfer in fifo sized chunks */
574 	words = t->len / bytes_per_word;
575 	bytes_done = 0;
576 
577 	while (bytes_done < t->len) {
578 		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
579 		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
580 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
581 					   tx_buf,
582 					   rx_buf,
583 					   words, bits);
584 		if (n < 0)
585 			break;
586 
587 		bytes_done += n * bytes_per_word;
588 		words -= n;
589 	}
590 
591 	return bytes_done;
592 }
593 
594 static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
595 				  u32 word, u8 bits)
596 {
597 	BUG(); /* unused but needed by bitbang code */
598 	return 0;
599 }
600 
601 #ifdef CONFIG_OF
602 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
603 {
604 	struct sh_msiof_spi_info *info;
605 	struct device_node *np = dev->of_node;
606 	u32 num_cs = 0;
607 
608 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
609 	if (!info) {
610 		dev_err(dev, "failed to allocate setup data\n");
611 		return NULL;
612 	}
613 
614 	/* Parse the MSIOF properties */
615 	of_property_read_u32(np, "num-cs", &num_cs);
616 	of_property_read_u32(np, "renesas,tx-fifo-size",
617 					&info->tx_fifo_override);
618 	of_property_read_u32(np, "renesas,rx-fifo-size",
619 					&info->rx_fifo_override);
620 
621 	info->num_chipselect = num_cs;
622 
623 	return info;
624 }
625 #else
626 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
627 {
628 	return NULL;
629 }
630 #endif
631 
632 static int sh_msiof_spi_probe(struct platform_device *pdev)
633 {
634 	struct resource	*r;
635 	struct spi_master *master;
636 	struct sh_msiof_spi_priv *p;
637 	int i;
638 	int ret;
639 
640 	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
641 	if (master == NULL) {
642 		dev_err(&pdev->dev, "failed to allocate spi master\n");
643 		return -ENOMEM;
644 	}
645 
646 	p = spi_master_get_devdata(master);
647 
648 	platform_set_drvdata(pdev, p);
649 	if (pdev->dev.of_node)
650 		p->info = sh_msiof_spi_parse_dt(&pdev->dev);
651 	else
652 		p->info = dev_get_platdata(&pdev->dev);
653 
654 	if (!p->info) {
655 		dev_err(&pdev->dev, "failed to obtain device info\n");
656 		ret = -ENXIO;
657 		goto err1;
658 	}
659 
660 	init_completion(&p->done);
661 
662 	p->clk = devm_clk_get(&pdev->dev, NULL);
663 	if (IS_ERR(p->clk)) {
664 		dev_err(&pdev->dev, "cannot get clock\n");
665 		ret = PTR_ERR(p->clk);
666 		goto err1;
667 	}
668 
669 	i = platform_get_irq(pdev, 0);
670 	if (i < 0) {
671 		dev_err(&pdev->dev, "cannot get platform IRQ\n");
672 		ret = -ENOENT;
673 		goto err1;
674 	}
675 
676 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
677 	p->mapbase = devm_ioremap_resource(&pdev->dev, r);
678 	if (IS_ERR(p->mapbase)) {
679 		ret = PTR_ERR(p->mapbase);
680 		goto err1;
681 	}
682 
683 	ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
684 			       dev_name(&pdev->dev), p);
685 	if (ret) {
686 		dev_err(&pdev->dev, "unable to request irq\n");
687 		goto err1;
688 	}
689 
690 	ret = clk_prepare(p->clk);
691 	if (ret < 0) {
692 		dev_err(&pdev->dev, "unable to prepare clock\n");
693 		goto err1;
694 	}
695 
696 	p->pdev = pdev;
697 	pm_runtime_enable(&pdev->dev);
698 
699 	/* The standard version of MSIOF use 64 word FIFOs */
700 	p->tx_fifo_size = 64;
701 	p->rx_fifo_size = 64;
702 
703 	/* Platform data may override FIFO sizes */
704 	if (p->info->tx_fifo_override)
705 		p->tx_fifo_size = p->info->tx_fifo_override;
706 	if (p->info->rx_fifo_override)
707 		p->rx_fifo_size = p->info->rx_fifo_override;
708 
709 	/* init master and bitbang code */
710 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
711 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
712 	master->flags = 0;
713 	master->bus_num = pdev->id;
714 	master->num_chipselect = p->info->num_chipselect;
715 	master->setup = spi_bitbang_setup;
716 	master->cleanup = spi_bitbang_cleanup;
717 
718 	p->bitbang.master = master;
719 	p->bitbang.chipselect = sh_msiof_spi_chipselect;
720 	p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
721 	p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
722 	p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
723 	p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
724 	p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
725 	p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
726 
727 	ret = spi_bitbang_start(&p->bitbang);
728 	if (ret == 0)
729 		return 0;
730 
731 	pm_runtime_disable(&pdev->dev);
732 	clk_unprepare(p->clk);
733  err1:
734 	spi_master_put(master);
735 	return ret;
736 }
737 
738 static int sh_msiof_spi_remove(struct platform_device *pdev)
739 {
740 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
741 	int ret;
742 
743 	ret = spi_bitbang_stop(&p->bitbang);
744 	if (!ret) {
745 		pm_runtime_disable(&pdev->dev);
746 		clk_unprepare(p->clk);
747 		spi_master_put(p->bitbang.master);
748 	}
749 	return ret;
750 }
751 
752 #ifdef CONFIG_OF
753 static const struct of_device_id sh_msiof_match[] = {
754 	{ .compatible = "renesas,sh-msiof", },
755 	{ .compatible = "renesas,sh-mobile-msiof", },
756 	{},
757 };
758 MODULE_DEVICE_TABLE(of, sh_msiof_match);
759 #endif
760 
761 static struct platform_driver sh_msiof_spi_drv = {
762 	.probe		= sh_msiof_spi_probe,
763 	.remove		= sh_msiof_spi_remove,
764 	.driver		= {
765 		.name		= "spi_sh_msiof",
766 		.owner		= THIS_MODULE,
767 		.of_match_table = of_match_ptr(sh_msiof_match),
768 	},
769 };
770 module_platform_driver(sh_msiof_spi_drv);
771 
772 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
773 MODULE_AUTHOR("Magnus Damm");
774 MODULE_LICENSE("GPL v2");
775 MODULE_ALIAS("platform:spi_sh_msiof");
776